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Total Entries: 10690
Title:
Regulation of sensitivity to TRAIL by the PTEN tumor suppressor
Authors:
Whang, Young E.; Yuan, Xiu-Juan; Liu, Yuanbo; Majumder, Samarpan; Lewis, Terrence D.
Abstract:
The ability of tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) to induce apoptosis preferentially in cancer cells is attractive for its development as a novel cancer therapeutic agent, but many cancer cell lines are resistant to TRAIL. While the molecular basis for TRAIL resistance is not always clear, a number of factors have been proposed to mediate TRAIL resistance, including decoy receptor, c-FLIP, nuclear factor (NF)-kappaB, and activation of antiapoptotic kinase signaling. Many growth factor receptors mediate their survival signals through the pathway involving recruitment and activation of phosphatidylinositol (PI) 3-kinase and the serine?threonine kinase Akt. The PTEN tumor suppressor is a phosphatase that dephosphorylates the phospholipids phosphorylated by PI-3 kinase, thereby opposing the action of PI 3-kinase, and acts as the primary negative regulator of the PI-3 kinase?Akt pathway in the cell. Loss of PTEN function occurs frequently in human tumors and leads to constitutive activation of Akt in cancer cells. Constitutively active Akt protects cells from TRAIL-induced apoptosis in multiple tumor types. Growth factors such as epidermal growth factor or insulin-like growth factor-1 also inhibit TRAIL-induced apoptosis through the Akt pathway. Akt exerts its antiapoptotic function by its ability to phosphorylate many key components of the cellular apoptotic regulatory circuit, such as BAD, MDM2, FOXO Forkhead transcription factors, and PED?PEA-15 as well as by its role in activating NF-kappaB. Because PTEN loss is common in tumors, strategies to inactivate Akt may be necessary to overcome TRAIL resistance and make TRAIL-based therapy more effective.
Published:
2004
Title:
Repeated sauna therapy reduces urinary 8-epi-prostaglnadin F2α
Authors:
Masuda, Akinori; Miyata, Masaaki; Kihara, Takashi; Minagoe, Shinichi; Tei, Chuwa
Abstract:
We have reported that repeated sauna therapy improves impaired vascular endothelial function in a patient with coronary risk factors. We hypothesized that sauna therapy decreases urinary 8-epi-prostaglandin F(2alpha) (PGF(2alpha)) levels as a marker of oxidative stress and conducted a randomized, controlled study. Twenty-eight patients with at least one coronary risk factor were divided into a sauna group (n = 14) and non-sauna group (n = 14). Sauna therapy was performed with a 60 degrees C far infrared-ray dry sauna for 15 minutes and then bed rest with a blanket for 30 minutes once a day for two weeks. Systolic blood pressure and increased urinary 8-epi-PGF(2alpha) levels in the sauna group were significantly lower than those in the non-sauna group at two weeks after admission (110 +/- 15 mmHg vs 122 +/- 13 mmHg, P \textless 0.05, 230 +/- 67 pg/mg x creatinine vs 380 +/- 101 pg/mg x creatinine, P \textless 0.0001, respectively). These results suggest that repeated sauna therapy may protect against oxidative stress, which leads to the prevention of atherosclerosis.
Published:
2004
Title:
Rheumatoid Arthritis
Authors:
Darlington, L. Gail
Abstract:
Historically and understandably, nutrition and dietary manipulation in the rheumatoid disease field has been highly controversial. Most of the early reports of benefit from dietary changes were anecdotal, and many of the early trials were poorly designed with results of doubtful credibility.
Published:
2004
Title:
Sequential injection analysis system for the determination of arsenic by hydride generation atomic absorption spectrometry
Authors:
Yin, Xuefeng; Zhang, Jianjun; Wang, Xiaofang
Abstract:
A sequential injection system which consists of a syringe pump, a selector valve, a multi-port valve, a gas-liquid separator and a solenoid valve for the determination of arsenic by hydride generation atomic absorption spectrometry using tetrahydroborate as reductant was developed. The reduction time of sample with tetrahydoborate has increased by keeping the reactant in gas-liquid separator by using the solenoid valve. Various parameters affecting the performance of the sequential injection system were optimized, including reaction-time, carrier gas flow, sample volume, tetrahydroborate volume and concentration. Established sequential injection hydride generation technique was simple and automated operation. A sample throughput of 112/h was achieved with 400 μL samples with a precision of 2.0% RSD at 4 μg/L As (n = 10) and a detection limit of 0.09 μg/L. Good agreement with the certified values was obtained for the determination of arsenic in standard reference materials.
Published:
2004
Title:
Slaughterhouse Blues: The Meat and Poultry Industry in North America
Authors:
Stull, Donald D; Broadway, Michael J
Abstract:
Published:
2004
Title:
Survival by hunting prehistoric human predators and animal prey
Authors:
George C. Frison; ebrary, Inc
Abstract:
Where the buffalo once roamed -- The education of a hunter -- Paleoindian hunters and extinct animals -- The North American bison -- The North American pronghorn -- The rocky mountain sheep -- Hunting the deer, elk, and other creatures -- Weaponry and tools used by the hunter -- Concluding thoughts.
Published:
2004
Title:
Temperature and surface-ocean water balance of the mid-Holocene tropical western Pacific
Authors:
Gagan, M. K.; Ayliffe, L.; Hopley, D.; Cali, J.A.; Mortimer, G.E.; Chappell, J.; McCulloch, M.T.; Head, J.M.
Abstract:
Published:
2004
Title:
The Effect of Mechanical Refrigeration on Nutrition in the United States
Authors:
Craig, Lee A.; Goodwin, Barry; Grennes, Thomas
Abstract:
Although the principles of refrigeration have been understood for thousands of years, the widespread use of mechanical refrigeration in the processing, shipping, and storing of perishable commodities began only in the 1890s. Because refrigeration facilitated the hygienic handling and storage of perishables, it promoted output growth, consumption, and nutrition through the spatial and temporal integration of markets for perishables. We estimate the impact of mechanical refrigeration on output and consumption, and hence on human nutrition, concentrating on the contribution from refrigerated dairy products, an important source of nutrients, particularly proteins and calcium.We conclude that the adoption of refrigeration in the late nineteenth-century United States increased dairy consumption by 1.7% and overall protein intake by 1.25% annually after the 1890s.The increase in protein consumption was particularly important to the growth of the human organism. According to our lower-bound estimates, refrigeration directly contributed at least 5.1% of the increase in adult stature of the postrefrigeration cohorts, and combined with the indirect effects associated with improvements in the quality of nutrients and the reduction in illness, the overall impact was considerably larger.
Published:
2004
Title:
The Escape from Hunger and Premature Death, 1700-2100: Europe, America, and the Third World
Authors:
Fogel, Robert William
Abstract:
Published:
2004
Title:
The broad spectrum revisited: evidence from plant remains
Authors:
Weiss, Ehud; Wetterstrom, Wilma; Nadel, Dani; Bar-Yosef, Ofer
Abstract:
Published:
2004
Title:
The ketogenic diet increases mitochondrial uncoupling protein levels and activity
Authors:
Sullivan, Patrick G.; Rippy, Nancy A.; Dorenbos, Kristina; Concepcion, Rachele C.; Agarwal, Aakash K.; Rho, Jong M.
Abstract:
Fatty acids are known to enhance mitochondrial uncoupling protein (UCP) activity. We asked whether a high-fat ketogenic diet (KD) increases UCP levels and activity in hippocampi of juvenile mice. Maximum mitochondrial respiration rates were significantly (p < 0.001) higher in KD- versus standard diet (SD)–treated animals, indicating increased UCP-mediated proton conductance that can reduce reactive oxygen species (ROS) production. Western blots showed significant (p < 0.05) or borderline significant increases in UCP2, UCP4, and UCP5 protein levels, and increased immunoreactivity to these three UCP isoforms was most prominently seen in the dentate gyrus of KD-fed mice. Finally, we found that oligomycin-induced ROS production was significantly (p
Published:
2004
Title:
Underestimation of risk due to exposure misclassification
Authors:
Grandjean, Philippe; Budtz-Jorgensen, Esben; Keiding, Niels; Weihe, Pal
Abstract:
Exposure misclassification constitutes a major obstacle when developing dose-response relationships for risk assessment. A non-differentional error results in underestimation of the risk. If the degree of misclassification is known, adjustment may be achieved by sensitivity analysis. The purpose of this study was to examine the full magnitude of measurement error in determining the prenatal exposure to methylmercury. We used data from a prospective study of a Faroese birth cohort. Two biomarkers of methylmercury exposure were available, i.e., the mercury concentrations in cord blood and in maternal hair (sampled at the time of parturition). The laboratory imprecision on both chemical analyses was thought to be below 5% coefficient of variation (CV). As a third exposure parameter, we used the dietary questionnaire response on frequency of whale meat dinners. Factor analysis and structural equation analysis were applied to assess the full extent of the imprecision. The calculated total imprecision much exceeded the known laboratory variation: the CV was 28-30% for the cord-blood concentration and 52-55% for the maternal hair concentration. The dietary questionnaire response was even more imprecise. These findings illustrate that measurement error may be greatly underestimated if judged solely from reproducibility or laboratory quality data. Adjustment by sensitivity analysis is meaningful only if realistic measurement errors are applied. When exposure measurement errors are overlooked or underestimated, decisions based on the precautionary principle will not appropriately reflect the degree of precaution that was intended.
Published:
2004
Title:
Weight Charts and Well Child Care: When the Pediatrician Became the Expert in Child Health
Authors:
Brosco, Jeffrey P.
Abstract:
Published:
2004
Title:
What interventions should we add to weight reducing diets in adults with obesity? A systematic review of randomized controlled trials of adding drug therapy, exercise, behaviour therapy or combinations of these interventions
Authors:
Avenell, A.; Brown, T. J.; McGee, M. A.; Campbell, M. K.; Grant, A. M.; Broom, J.; Jung, R. T.; Smith, W. C. S.
Abstract:
Background Evidence is needed for the effectiveness of interventions given with reducing diets for obese adults: drug therapy, exercise, or behaviour therapy. Methods We systematically reviewed randomized controlled trials in any language. We searched 13 databases and handsearched journals. Trials lasted 1 year or more. One investigator extracted data and a second checked data extraction. Trial quality was assessed. Results Adding orlistat to diet was associated with weight change for up to 24 months (−3.26 kg, 95% CI, −4.15 to −2.37 kg), and statistically significant beneficial changes were found for total and LDL cholesterol, blood pressure and glycaemic control. Adding sibutramine to diet was associated with a 12 month weight change of −4.18 kg (95% CI, −5.14 to −3.21 kg), and statistically significant beneficial effects on high density lipoprotein cholesterol (HDL) and triglycerides (TGs), but an increase in diastolic blood pressure. Adding exercise to diet, or to diet and behaviour therapy, was associated with improved weight loss for up to 36 months and improvements in HDL, TGs and blood pressure. Adding behaviour therapy to diet, or to diet and sibutramine together, was associated with improved weight loss for up to 18 months. Adding drugs, exercise or behaviour therapy to dietary advice was each associated with similar weight change. Conclusions Adding orlistat, sibutramine, exercise, or behaviour modification to dietary advice can improve long-term weight loss.
Published:
2004
Title:
[Leveling the hyperlipidemic effect of beta-adrenoblockers by means of antiatherogenic vegetarian diet]
Authors:
Medkova, I. L.; Ieromuzo, A. A.; Ivanov, A. N.; Mosiakina, L. I.; Biriukova, L. S.
Abstract:
The purpose of the study was to examine the capacities of correction of impaired lipid metabolism in patients with CHD receiving selective beta-adrenoblockers (beta-AB) by using an antiatherogenic milk-and-vegetable diet. According to the type of antiatherogenic diet, 67 patients were divided into 2 groups: 1) 42 patients were on an antiatherogenic vegetarian diet (a vegetarian group--VG) and 2) 25 patients received routine mixed diet No. 10c (a control group--CG). At the same time all the patients received similar antianginal drug therapy including the selective beta-AB atenolol in a dose of 50 mg/day. The vegetarian diet without special hypolipidemic therapy had a marked normalizing effect on the serum lipid spectrum in patients with CHD. Thus, in VG, by the end of treatment, the level of total cholesterol significantly decreased by 16% while in the controls it increased by 13%. High-density lipoprotein cholesterol increased in VG and decreased in CG, therefore the atherogenicity coefficient considerably rose. These were true for triglycerides and very low-density lipoprotein cholesterol. These parameters significantly decreased in VG (by more than 30%) and increased in CG (by 16%). Among the clinical symptoms, a more pronounced decrease in blood pressure in the patients on vegetarian diet and a more significant increase in their exercise tolerance. Balanced antiatherogenic milk-and-vegetable diet in patients with coronary heart disease prevents the hyperlipidemic effect caused by the selective beta-AB atenolol and it is an agent for preventing its negative effect on lipid metabolism.
Published:
2004
Title:
A moderately low phosphate intake may provide health benefits analogous to those conferred by UV light - a further advantage of vegan diets
Authors:
McCarty, M. F.
Abstract:
Although exposure to ultraviolet light is often viewed as pathogenic owing to its role in the genesis of skin cancer and skin aging, there is growing epidemiological evidence that such exposure may decrease risk for a number of more serious cancers, may have a favorable impact on blood pressure and vascular health, and may help to prevent certain autoimmune disorders - in addition to its well-known influence on bone density. Most likely, these health benefits are reflective of improved vitamin D status. Increased synthesis or intake of vitamin D can be expected to down-regulate parathyroid hormone (PTH), and to increase autocrine synthesis of its active metabolite calcitriol in certain tissues; these effects, in turn, may impact cancer risk, vascular health, immune regulation, and bone density through a variety of mechanisms. Presumably, a truly adequate supplemental intake of vitamin D - manyfold higher than the grossly inadequate current RDA - could replicate the benefits of optimal UV exposure, without however damaging the skin. Diets moderately low in bioavailable phosphate - like many vegan diets - might be expected to have a complementary impact on disease risks, inasmuch as serum phosphate suppresses renal calcitriol synthesis while up-regulating that of PTH. A proviso is that the impact of dietary phosphorus on bone health is more equivocal than that of vitamin D. Increased intakes of calcium, on the other hand, down-regulate the production of both PTH and calcitriol - the latter effect may explain why the impact of dietary calcium on cancer risk (excepting colon cancer), hypertension, and autoimmunity is not clearly positive. An overview suggests that a vegan diet supplemented with high-dose vitamin D should increase both systemic and autocrine calcitriol production while suppressing PTH secretion, and thus should represent a highly effective way to achieve the wide-ranging health protection conferred by optimal UV exposure.
Published:
2003-12
Title:
Boys will be boys: fathers' perspectives on ADHD symptoms, diagnosis, and drug treatment
Authors:
Singh, Ilina
Abstract:
Fathers tend to be largely absent from research and clinical settings related to attention-deficit/hyperactivity disorder (ADHD), as well as from public forums related to ADHD, such as educational conferences and parent support groups. Because of these absences, little is known about fathers' perspectives on ADHD symptoms, diagnosis, and drug treatment. This article presents findings from a qualitative study involving 39 mothers and 22 fathers of boys with ADHD. In-depth interviews were conducted with participants using a picture-based method that elicited detailed narratives. Results of this study suggest that fathers' perspectives on ADHD behaviors, diagnosis, and drug treatment can be categorized along two dimensions: "reluctant believers" and "tolerant nonbelievers." Across these two dimensions, several related factors are relevant to fathers' perspectives: resistance to a medical framework for understanding their sons' behaviors; identification with the sons' symptomatic behaviors; and resistance to drug treatment with stimulants. These factors may help to explain, in turn, fathers' absences from clinical evaluations of their sons' behaviors. The study affirms the importance of fathers' perspectives to the clinical evaluation and treatment of boys' symptomatic behaviors.
Published:
2003-12
Title:
Low levels of osteocalcin and leptin in serum of vegetarian prepubertal children
Authors:
Ambroszkiewicz, Jadwiga; Laskowska-Klita, Teresa; Klemarczyk, Witold
Abstract:
BACKGROUND: Scientific literature points to the positive association between vegetarian diet and reduced risk for cardiovascular diseases, some types of cancer and diabetes. On the other hand elimination of animal products from the diet decreases the intake of some essential nutrients which may influence bone metabolism. This is a very important problem especially in childhood and adolescence, when growth and bone turnover are the most intensive. Bone metabolism is regulated by variety factors, which are involved in the bone formation and bone resorption processes. Osteocalcin is one of the markers of bone formation (produced by osteoblast) which plays an important role in the regulation of bone growth. Recent data support the concept that other modulators such as leptin (hormone from adipose tissue) may influence bone formation process. AIM: Our study is designed to investigate serum concentration of osteocalcin and leptin in prepubertal children with two different nutritional habits: vegetarian and omnivorous diet. MATERIAL AND METHODS: We examined 49 healthy children in age 2-10 years, who were divided into vegetarian and omnivores groups. RESULTS: The serum osteocalcin levels in prepubertal children on vegetarian diet was significantly lower than in nonvegetarians (86.7+/-27.4 microg/L versus 100.1+/-16.4 microg/L; p<0.05). Lower level of osteocalcin is accompanied by lower leptin concentration. In children on vegetarian diet mean leptin level was 3.0+/-1.0 microg/L, whereas in omnivorous children it was 5.5+/-2.0 microg/L, (p
Published:
2003-12
Title:
Relationship between the amount of linoleic acid in the diet and that in the adipose tissue of adult cats living freely in households
Authors:
Plantinga, E. A.; Van Dijk, N.; Van Niel, M. H. F.; Beynen, A. C.
Abstract:
The present study was carried out to ascertain whether linoleic acid intake and the content of this fatty acid in adipose tissue are correlated in cats. The linoleic acid intake, as estimated from a food intake questionnaire, was indeed correlated with the linoleic acid content of the abdominal body fat in 165 adult, female cats. A statistically significant linear correlation coefficient of 0.43 was found between the percentage of linoleic acid in the adipose tissue and that in the diet. It is plausible that the observed acid content of adipose tissue of free-living cats may be considered to be a valid biomarker of linoleic acid intake that might be used in studies on diet and chronic disease.
Published:
2003-12
Title:
Self-management by uninsured Filipino immigrants with Type 2 Diabetes
Authors:
Leake, Anne Reynolds
Abstract:
Filipino Americans have a higher prevalence of type 2 diabetes than the national average. Good self-management (SM) of diabetes is required for good outcomes. Uninsured Filipino immigrants face cultural and financial barriers to good outcomes. The purpose of this study was to describe self-management by uninsured Filipino immigrants with type 2 diabetes. Results from the study will reduce the risks of complications by improving self-management education. Qualitative research on diabetes self-management [SM] and research on Filipinos and health were reviewed. Concept analysis of SM using the Wilsonian method (Wilson, 1963) produced eight essential elements. An applied ethnography was conducted with 11 participant interviews and 100 hours of field observation over 10 months. Participants were two men and nine women, ages 57 to 74, attending a free diabetes clinic in federally funded community health center in urban Hawaiʻi. The explanatory model [EM] (Kleimnan, 1980) and a model for health disparities (Cooper, 2002), guided the study. Purposive sampling achieved a range of participants across factors of age, recent HgbA1c, years with diabetes, and years in Hawaiʻi. An inquiry audit by an external expert was done. Significant statements coded into four domains of barriers, the explanatory model, family and self-management behavior. Participants' EMs combined Western and naturalistic explanations, including avoiding a hot climate and use of local plants (bittermelon and noni) recommended by other Filipinos. All participants exercised and most used SM strategies of control and moderation. Four cultural themes were induced from the data: 1.) rice is more than just a starch; 2.) worry is a Filipino pastime; 3.) advice is a gift freely given and received; and 4.) the family is everything. Participants demonstrated five of the essential elements of SM but did not do as well with consulting health care team, problem solving and increasing self-efficacy. The family's group efficacy, as much as self-efficacy, influenced behavior change. Participants' SM compared favorably to other populations for behavioral change, emotional distress and support from family and friends. Implications for clinical practice were emphasis on group efficacy and reducing barriers to medical consultation. Further research to explore the concept of worry was recommended.
Published:
2003-12
Title:
The effects of a low-carbohydrate regimen on glycemic control and serum lipids in diabetes mellitus
Authors:
O' Neill, Daniel F.; Westman, Eric C.; Bernstein, Richard K.
Abstract:
The Diabetes Complications and Control Trial (DCCT) established that diabetic complications could be reduced by improvement in glycemic control. The ideal diabetes treatment protocol would maintain blood glucose levels in normal ranges without resulting in frequent hypoglycemia. Because several studies suggest an inverse relationship between carbohydrate consumption and the level of glycemic control, the effects of an intensive treatment program, which included dietary carbohydrate restriction, are examined in this paper. A chart review was performed of 30 patients who self-reported the consumption of 30 g of carbohydrate daily, followed a strict insulin regimen, monitored blood glucose levels at least four times daily, and had follow-up clinical visits or phone calls with their physician. For both type I and type II diabetics, there were significant improvements in glycemic control and mean fasting lipid profiles at follow-up. The mean hemoglobin A1c decreased by 27.8% from 7.9 to 5.7 (p < 0.001). The LDL cholesterol decreased by 16.5%, from 155.4 to 129.7 mg/dL (p = 0.004). The triglycerides decreased by 31.1%, from 106.8 to 73.6 mg/dL (p = 0.005). The HDL cholesterol increased by 43.3%, from 50.4 to 72.2 mg/dL (p < 0.001). The cholesterol/HDL ratio decreased by 31.5%, from 4.99 to 3.42 (p
Published:
2003-12
Title:
Toxicity of glyoxals--role of oxidative stress, metabolic detoxification and thiamine deficiency
Authors:
Shangari, N.; Bruce, W. R.; Poon, R.; O'Brien, P. J.
Abstract:
Glyoxals are reactive alpha-oxoaldehydes that are formed endogenously from sugars, the levels of which are increased in various pathological conditions associated with hyperglycaemia and thiamine deficiency. However, the molecular cytotoxic mechanisms of glyoxal are not known. Results presented here and in the other studies cited provide a glimpse into the cytotoxicity mechanisms involved and their pathological implications. We found that glyoxal (10 microM) markedly increased the susceptibility of hepatocyte glutathione (GSH) to oxidation by hydrogen peroxide (H(2)O(2)) and markedly increased cytotoxicity by compromising the cellular antioxidant enzyme system. At higher concentrations, glyoxal was cytotoxic towards hepatocytes, which can be attributed to GSH depletion, oxidative stress and mitochondrial toxicity. Aminoguanidine or penicillamine protected the hepatocytes. Glyoxal cytotoxicity was prevented by increasing glyoxal metabolism with thiamine or NAD(P)H generators, and was increased in GSH- or thiamine-deficient hepatocytes. It was also found that feeding rats reduced thiamine levels in a diet high in simple sugars increased the number of aberrant crypt foci/colon in the absence of clinical evidence of beriberi. This was associated with decreased plasma thiamine and low erythrocyte transketolase activity. Western diets, which are frequently poor in thiamine and high in sugars, could result in increased levels of endogenous glyoxals, which in turn may lead to a predisposition to AGE (advanced glycation end-product)-related pathologies and neoplastic conditions.
Published:
2003-12
Title:
[Lipids and vitamin A and E status in vegetarian children]
Authors:
Chełchowska, Magdalena; Laskowska-Klita, Teresa; Klemarczyk, Witold
Abstract:
BACKGROUND: The vegetarian diet may play a preventive role in the development of chronic diseases such as coronary heart disease, cancer and diabetes. In the literature only a few papers concerning benefits to health from vegetarian diet have been reported in children. AIM: The aim of this study was to investigate serum concentration of vitamin A (retinol) and E (alpha-tocopherol) in children on vegetarian and omnivorous diet. Material and methods. Vitamins A and E were measured by high-pressure liquid chromatography (HPLC) in blood of 17 vegetarians and 16 nonvegetarian children. RESULTS: In the group of vegetarian mean plasma concentration of vitamin A and E was statistically lower as compared to those in nonvegetarian children (1.56 micromol/l vs 1.93 micromol/l, p < 0.05; 13.6 micromol/l vs 18.4 micromol/l, p
Published:
2003-12
Title:
A review of low-carbohydrate ketogenic diets
Authors:
Westman, Eric C.; Mavropoulos, John; Yancy, William S.; Volek, Jeff S.
Abstract:
In response to the emerging epidemic of obesity in the United States, a renewal of interest in alternative diets has occurred, especially in diets that limit carbohydrate intake. Recent research has demonstrated that low-carbohydrate ketogenic diets can lead to weight loss and favorable changes in serum triglycerides and high-density lipoprotein cholesterol. This review summarizes the physiology and recent clinical studies regarding this type of diet.
Published:
2003-11
Title:
Effect of a high saturated fat and no-starch diet on serum lipid subfractions in patients with documented atherosclerotic cardiovascular disease
Authors:
Hays, James H.; DiSabatino, Angela; Gorman, Robert T.; Vincent, Simi; Stillabower, Michael E.
Abstract:
OBJECTIVE: To determine whether a diet of high saturated fat and avoidance of starch (HSF-SA) results in weight loss without adverse effects on serum lipids in obese nondiabetic patients. PATIENTS AND METHODS: Twenty-three patients with atherosclerotic cardiovascular disease participated in a prospective 6-week trial at the Christiana Care Medical Center in Newark, Del, between August 2000 and September 2001. All patients were obese (mean +/- SD body mass index [BMI], 39.0+/-7.3 kg/m2) and had been treated with statins before entry in the trial. Fifteen obese patients with polycystic ovary syndrome (BMI, 36.1+/-9.7 kg/m2) and 8 obese patients with reactive hypoglycemia (BMI, 46.8+/-10 kg/m2) were monitored during an HSF-SA diet for 24 and 52 weeks, respectively, between 1997 and 2000. RESULTS: In patients with atherosclerotic cardiovascular disease, mean +/- SD total body weight (TBW) decreased 5.2%+/-2.5% (P<.001) as did body fat percentage (P=.02). Nuclear magnetic resonance spectroscopic analysis of lipids showed decreases in total triglycerides (P<.001), very low-density lipoprotein (VLDL) triglycerides (P<.001), VLDL size (P<.001), large VLDL concentration (P<.001), and medium VLDL concentration (P<.001). High-density lipoprotein (HDL) and LDL concentrations were unchanged, but HDL size (P=.01) and LDL size (P=.02) increased. Patients with polycystic ovary syndrome lost 14.3%+/-20.3% of TBW (P=.008) and patients with reactive hypoglycemia lost 19.9%+/-8.7% of TBW (P
Published:
2003-11
Title:
Structural differences between rye and wheat breads but not total fiber content may explain the lower postprandial insulin response to rye bread
Authors:
Juntunen, Katri S.; Laaksonen, David E.; Autio, Karin; Niskanen, Leo K.; Holst, Jens J.; Savolainen, Kari E.; Liukkonen, Kirsi-Helena; Poutanen, Kaisa S.; Mykkänen, Hannu M.
Abstract:
BACKGROUND: Rye bread has a beneficial effect on the postprandial insulin response in healthy subjects. The role of rye fiber in insulin and glucose metabolism is not known. OBJECTIVE: The aim of the study was to determine the effect of the content of rye fiber in rye breads on postprandial insulin and glucose responses. DESIGN: Nineteen healthy postmenopausal women aged 61 +/- 1 y, with a body mass index (in kg/m(2)) of 26.0 +/- 0.6, and with normal glucose tolerance participated in the study. The test products were refined wheat bread (control), endosperm rye bread, traditional rye bread, and high-fiber rye bread; each bread provided 50 g available carbohydrate and was served with breakfast. Plasma glucose, insulin, glucose-dependent insulinotropic polypeptide, glucagon-like peptide 1, and serum C-peptide were measured in fasting and 8 postprandial blood samples. In vitro starch hydrolysis and the microscopic structure of the breads were also determined. RESULTS: Postprandial insulin, glucose-dependent insulinotropic polypeptide, and C-peptide responses to the rye breads were significantly lower than the response to the control; no significant differences in insulin and C-peptide responses to the rye breads were found. Glucose and glucagon-like peptide 1 responses to the rye breads were not significantly different from those to the control, except at 150 and 180 min. In vitro starch hydrolysis was slower in all rye breads than in the control, and the structure of continuous matrix and starch granules differed between the rye and control breads. CONCLUSION: Total fiber content does not explain the lower postprandial insulin response to rye bread than to wheat bread, but structural differences between rye and wheat breads might.
Published:
2003-11
Title:
Clinical use of a carbohydrate-restricted diet to treat the dyslipidemia of the metabolic syndrome
Authors:
Hickey, Joseph T.; Hickey, Lisa; Yancy, William S.; Hepburn, Juanita; Westman, Eric C.
Abstract:
BACKGROUND: The metabolic syndrome is characterized by an atherogenic dyslipidemia identifiable using lipoprotein subclass analysis. This study assesses the effect of a carbohydrate-restricted diet on the dyslipidemia of the metabolic syndrome in a clinical setting. METHODS: This is a retrospective chart review of patients attending a preventive medicine clinic using lipoprotein subclass analysis (by NMR spectroscopy) to identify the atherogenic dyslipidemia. If present, patients were counseled to begin a carbohydrate-restricted diet (< 20 g/day). Patients already on statin therapy were included only if the medication dose was not changed. The outcomes were changes in body weight, fasting serum lipid profiles and serum lipoprotein subclasses. RESULTS: Of 122 patients identified, 80 patients had complete pre- and post-treatment data. The mean (+/-SD) age was 66 +/- 9 years, baseline weight was 85 +/- 12 kg, BMI was 28.1 +/- 3.6, 73% were male, 99% were Caucasian. Sixty-five percent were taking statin medication. Carbohydrate-restriction led to a 13% reduction in total cholesterol, 16% reduction in LDL cholesterol, 38% reduction in triglycerides, and a 13% increase in HDL cholesterol (all p values < 0.001). Carbohydrate-restriction also led to a reduction in LDL particle concentration of 28%, a reduction in small LDL of 82%, a reduction of large VLDL of 62%, and an increase in large HDL of 30% (all p values
Published:
2003-09
Title:
Effect of low-carbohydrate, unlimited calorie diet on the treatment of childhood obesity: a prospective controlled study
Authors:
Bailes, James R.; Strow, Misty T.; Werthammer, Joseph; McGinnis, Richard A.; Elitsur, Yoram
Abstract:
BACKGROUND: Childhood obesity has been recognized as the new epidemic in developed countries. Caloric restriction with physical activity is the main therapeutic treatment available for these children. We compared two different dietary protocols to assess treatment efficacy. METHODS: Obese children from the Pediatric Endocrinology clinic were prospectively recruited for the study. Children and their parents were allowed to choose one of two dietary protocols: (1) carbohydrate restricted diet (<30 g/day), with unlimited calories, protein, and fat (High protein, Low CHO Diet), and (2) calorie restricted diet (Low Cal Diet). Anthropometric data were measured at baseline and at the 2 month follow up appointment. RESULTS: Thirty-seven children completed the study of whom 27 chose High Protein, Low CHO Diet and 10 chose Low Cal diet. No differences in gender ratio, age, or BMI were observed at baseline. At 2 months, children in the High Protein, Low CHO Diet lost an average of 5.21 +/- 3.44 kg (p < 0.001) and decreased their BMI by 2.42 +/- 1.3 points (p < 0.001), compared to the children in the Low Cal Diet who gained an average of 2.36 +/- 2.54 kg and 1.00 point on the BMI value (p
Published:
2003-09
Title:
Metabolic correlates of hominid brain evolution
Authors:
Leonard, William R.; Robertson, Marcia L.; Snodgrass, J. Josh; Kuzawa, Christopher W.
Abstract:
Large brain sizes in humans have important metabolic consequences as humans expend a relatively larger proportion of their resting energy budget on brain metabolism than other primates or non-primate mammals. The high costs of large human brains are supported, in part, by diets that are relatively rich in energy and other nutrients. Among living primates, the relative proportion of metabolic energy allocated to the brain is positively correlated with dietary quality. Humans fall at the positive end of this relationship, having both a very high quality diet and a large brain size. Greater encephalization also appears to have consequences for aspects of body composition. Comparative primate data indicate that humans are 'under-muscled', having relatively lower levels of skeletal muscle than other primate species of similar size. Conversely, levels of body fatness are relatively high in humans, particularly in infancy. These greater levels of body fatness and reduced levels of muscle mass allow human infants to accommodate the growth of their large brains in two important ways: (1) by having a ready supply of stored energy to 'feed the brain', when intake is limited and (2) by reducing the total energy costs of the rest of the body. Paleontological evidence indicates that the rapid brain evolution observed with the emergence of Homo erectus at approximately 1.8 million years ago was likely associated with important changes in diet and body composition.
Published:
2003-09
Title:
Metabolic syndrome and low-carbohydrate ketogenic diets in the medical school biochemistry curriculum
Authors:
Feinman, Richard D.; Makowske, Mary
Abstract:
One of Robert Atkins contributions was to define a diet strategy in terms of an underlying metabolic principle ("the science behind Atkins"). The essential feature is that, by reducing insulin fluxes, lipids are funnelled away from storage and oxidized. Ketosis can be used as an indicator of lipolysis. A metabolic advantage is also proposed: controlled carbohydrates leads to greater weight loss per calorie than other diets. Although the Atkins diet and its scientific rationale are intended for a popular audience, the overall features are consistent with current metabolic ideas. We have used the Atkins controlled-carbohydrate diet as a focal point for teaching nutrition and metabolism in the first-year medical school curriculum. By presenting metabolism in the context of the current epidemic of obesity and of metabolic syndrome and related disorders, we provide direct application of the study of metabolic pathways, a subject not traditionally considered by medical students to be highly relevant to medical practice. We present here a summary of the metabolic basis of the Atkins diet as we teach it to medical students. We also discuss a proposed mechanism for metabolic advantage that is consistent with current ideas and that further brings out ideas in metabolism for students. The topics that are developed include the role of insulin and glucagon in lipolysis, control of lipoprotein lipase, the glucose-glycogen-gluconeogenesis interrelations, carbohydrate-protein interactions and ketosis. In essence, the approach is to expand the traditional feed-fast (post-absorptive) cycles to include the effect of low-carbohydrate meals: the disease states studied are generalized from traditional study of diabetes to include obesity and metabolic syndrome. The ideal diet for weight loss and treatment of metabolic syndrome, if it exists, remains to be determined, but presenting metabolism in the context of questions raised by the Atkins regimen prepares future physicians for critical analysis of clinical and basic metabolic information.
Published:
2003-09
Title:
Natural selection on the olfactory receptor gene family in humans and chimpanzees
Authors:
Gilad, Yoav; Bustamante, Carlos D.; Lancet, Doron; Pääbo, Svante
Abstract:
The olfactory receptor (OR) genes constitute the largest gene family in mammalian genomes. Humans have >1,000 OR genes, of which only approximately 40% have an intact coding region and are therefore putatively functional. In contrast, the fraction of intact OR genes in the genomes of the great apes is significantly greater (68%-72%), suggesting that selective pressures on the OR repertoire vary among these species. We have examined the evolutionary forces that shaped the OR gene family in humans and chimpanzees by resequencing 20 OR genes in 16 humans, 16 chimpanzees, and one orangutan. We compared the variation at the OR genes with that at intergenic regions. In both humans and chimpanzees, OR pseudogenes seem to evolve neutrally. In chimpanzees, patterns of variability are consistent with purifying selection acting on intact OR genes, whereas, in humans, there is suggestive evidence for positive selection acting on intact OR genes. These observations are likely due to differences in lifestyle, between humans and great apes, that have led to distinct sensory needs.
Published:
2003-09
Title:
Serum cholesterol levels and in-hospital mortality in the elderly
Authors:
Onder, Graziano; Landi, Francesco; Volpato, Stefano; Fellin, Renato; Carbonin, Pierugo; Gambassi, Giovanni; Bernabei, Roberto
Abstract:
PURPOSE: Although total cholesterol levels among middle-aged persons correlate with long-term mortality from all causes, this association remains controversial in older persons. We explored whether total cholesterol levels were independently associated with in-hospital mortality among elderly patients. METHODS: We analyzed data from a large collaborative observational study, the Italian Group of Pharmacoepidemiology in the Elderly (GIFA), which collected data on hospitalized patients. A total of 6984 patients aged 65 years or older who had been admitted to 81 participating medical centers during four survey periods (from 1993 to 1998) were enrolled. Patients were divided into four groups based on total cholesterol levels at hospital admission: or=240 mg/dL (n = 940). RESULTS: Patients (mean [+/- SD] age, 78 +/- 7 years) were hospitalized for an average of 15 +/- 10 days. The mean total cholesterol level was 186 +/- 49 mg/dL. A total of 202 patients died during hospitalization. Mortality was inversely related to cholesterol levels (or=240 mg/dL: 1.7% [16/940]; P for linear trend <0.001). After adjustment for potential confounders (demographic characteristics, smoking, alcohol use, indicators of nutritional status, markers of frailty, and comorbid conditions), low cholesterol levels continued to be associated with in-hospital mortality. Compared with patients who had cholesterol levels or=240 mg/dL. These estimates were similar after further adjustment for inflammatory markers and after excluding patients with liver disease. CONCLUSIONS: Among older hospitalized adults, low serum cholesterol levels appear to be an independent predictor of short-term mortality.
Published:
2003-09
Title:
Survival of the fattest: fat babies were the key to evolution of the large human brain
Authors:
Cunnane, Stephen C.; Crawford, Michael A.
Abstract:
In the past 2 million years, the hominid lineage leading to modern humans evolved significantly larger and more sophisticated brains than other primates. We propose that the modern human brain was a product of having first evolved fat babies. Hence, the fattest (infants) became, mentally, the fittest adults. Human babies have brains and body fat each contributing to 11-14% of body weight, a situation which appears to be unique amongst terrestrial animals. Body fat in human babies provides three forms of insurance for brain development that are not available to other land-based species: (1) a large fuel store in the form of fatty acids in triglycerides; (2) the fatty acid precursors to ketone bodies which are key substrates for brain lipid synthesis; and (3) a store of long chain polyunsaturated fatty acids, particularly docosahexaenoic acid, needed for normal brain development. The triple combination of high fuel demands, inability to import cholesterol or saturated fatty acids, and dependence on docosahexaenoic acid puts the mammalian brain in a uniquely difficult situation compared with other organs and makes its expansion in early humans all the more remarkable. We believe that fresh- and salt-water shorelines provided a uniquely rich, abundant and accessible food supply, and the only viable environment for evolving both body fat and larger brains in human infants.
Published:
2003-09
Title:
The bioavailability of quercetin in pigs depends on the glycoside moiety and on dietary factors
Authors:
Cermak, Rainer; Landgraf, Sandra; Wolffram, Siegfried
Abstract:
Recent investigations suggest that the bioavailability of quercetin depends on the glycoside moiety of the quercetin glycosides present in the diet. In this study, we compared the oral bioavailability of quercetin from quercetin aglycone and two different quercetin glycosides in pigs. Pigs were equipped with permanent catheters in the jugular and portal veins. After consumption of a test meal containing the respective compounds, blood samples were drawn repeatedly over a period of 24 h and analyzed by HPLC. In a first set of experiments, pigs received a single oral dose of 148 micromol/kg body (equivalent to 50 mg/kg) provided as quercetin aglycone, quercetin-3-O-glucoside (Q3G) or quercetin-3-O-glucorhamnoside (rutin) as part of their diet. The main metabolite in plasma was always conjugated quercetin, whereas free quercetin was not detected in either the jugular or the portal blood. For Q3G and rutin, the relative total bioavailability of quercetin (i.e., conjugated quercetin and conjugated methylethers of quercetin) was 148% (P = 0.07) and 23% (P < 0.05), respectively, compared with quercetin aglycone. In another experiment with a dose of 29.6 micro mol/kg (equivalent to 10 mg/kg), the relative total bioavailability of Q3G was 167% compared with the aglycone (P
Published:
2003-09
Title:
Thermodynamics and metabolic advantage of weight loss diets
Authors:
Feinman, Richard D.; Fine, Eugene J.
Abstract:
Published reports show that low carbohydrate weight loss diets provide a metabolic advantage, a greater weight loss per calorie consumed compared to isocaloric high carbohydrate diets. These reports have not been refuted but rather largely ignored, presumably because of the apparent violation of the laws of thermodynamics ("a calorie is a calorie"). In this review, we show that there is no such violation of thermodynamic laws. Energy utilization of different diets depends on the chemical pathway taken and a metabolic analysis of the efficiency of different pathways reveals large differences. Likewise, thermogenesis produced by diets of different macronutrient composition varies widely. We present a plausible mechanism that depends on the inefficiency of metabolic cycles and, in particular, protein turnover. A low carbohydrate diet makes demands on protein turnover for gluconeogenesis. From a theoretical point of view,energy balance between two diets is to be expected only if the subjects have the same final physiologic state, and only if all of the changes contributing to the energy, heat, work and chemical effects are known. Most diet experiments do not conform to this ideal. There is no theoretical contradiction in metabolic advantage and no theoretical barrier to accepting reports describing this effect.
Published:
2003-09
Title:
[Appetite regulation by ghrelin - a novel neuro-endocrine gastric peptide hormone in the gut-brain-axis]
Authors:
Hagemann, D.; Meier, J. J.; Gallwitz, B.; Schmidt, W. E.
Abstract:
Ghrelin a novel peptide consisting of 28 amino acids was first identified in the stomach in 1999. It is mainly produced in endocrine cells of the human gastric mucosa, but it was also found in several other tissues e. g. in the pituitary, the hypothalamus and the pancreas. The functional receptor belongs to the family of the 7-transmembrane G-protein receptors and is predominantly detected in the pituitary and at lower levels in hypothalamic nuclei, the stomach, heart, lungs, kidneys, gut, the adipose and many other tissues. According to the widespread distribution of the peptide and its receptor, ghrelin has multiple biological effects: it stimulates the release of growth hormone in the pituitary and induces a rise in the serum concentration of ACTH, cortisol, catecholamines and prolactin. Ghrelin causes an increase of food intake and body weight by stimulating the production of neuropeptide Y (NPY) and agouti-related protein (AGP) in the nucleus arcuatus. It further leads to elevated concentrations of plasma glucose. A physiological antagonism between ghrelin and GLP-1 in the hypothalamic regulation of appetite is being discussed. The basic serum level of ghrelin depends on the state of nutrition and is negatively correlated with the body-mass-index. It shows a certain pattern of variation before and after food intake with a preprandial increase and a postprandial decrease. Ghrelin modulates gastric acid secretion and the gastrointestinal motility via vagal cholinergic pathways. The discovery of ghrelin definitely contributes to the understanding of the growth-hormone secretion and of the regulation of appetite and food intake.
Published:
2003-09
Title:
Benefits and barriers to the consumption of a vegetarian diet in Australia
Authors:
Lea, Emma; Worsley, Anthony
Abstract:
OBJECTIVE: The aim of this study was to examine consumers' perceived benefits and barriers to the consumption of a vegetarian diet. DESIGN: Survey (written questionnaire) that included questions on perceived benefits and barriers to the consumption of a vegetarian diet. SETTING: South Australia. SUBJECTS: Six hundred and one randomly selected South Australians. RESULTS: The main perceived barriers to adopting a vegetarian diet were enjoying eating meat and an unwillingness to alter eating habits. This was the case for men, women and all age groups, although there were sex and age differences present in over half of the barrier items. For example, family food preferences were a greater problem for women than for men, while the oldest group was more likely to agree that humans are 'meant' to eat meat than the younger groups. The main benefits associated with vegetarian diets were health benefits: increased fruit and vegetable intake, decreased saturated fat intake, weight control. Animal welfare-related benefits and disease prevention were also important. Age and sex differences were apparent, although age differences were more important than sex differences. CONCLUSIONS: The majority of respondents perceived there to be health benefits associated with the consumption of a vegetarian diet, but also, predictably, enjoyed eating meat. Given this, it is likely that interest in plant-based diets that contain some meat is higher than that in no-meat diets. An understanding of the perceived benefits and barriers of consuming a vegetarian diet will allow the implementation of strategies to influence meat and vegetarianism beliefs, dietary behaviour and, hence, public health.
Published:
2003-08
Title:
Benefits and barriers to the consumption of a vegetarian diet in Australia
Authors:
Lea, Emma; Worsley, Anthony
Abstract:
OBJECTIVE: The aim of this study was to examine consumers' perceived benefits and barriers to the consumption of a vegetarian diet. DESIGN: Survey (written questionnaire) that included questions on perceived benefits and barriers to the consumption of a vegetarian diet. SETTING: South Australia. SUBJECTS: Six hundred and one randomly selected South Australians. RESULTS: The main perceived barriers to adopting a vegetarian diet were enjoying eating meat and an unwillingness to alter eating habits. This was the case for men, women and all age groups, although there were sex and age differences present in over half of the barrier items. For example, family food preferences were a greater problem for women than for men, while the oldest group was more likely to agree that humans are 'meant' to eat meat than the younger groups. The main benefits associated with vegetarian diets were health benefits: increased fruit and vegetable intake, decreased saturated fat intake, weight control. Animal welfare-related benefits and disease prevention were also important. Age and sex differences were apparent, although age differences were more important than sex differences. CONCLUSIONS: The majority of respondents perceived there to be health benefits associated with the consumption of a vegetarian diet, but also, predictably, enjoyed eating meat. Given this, it is likely that interest in plant-based diets that contain some meat is higher than that in no-meat diets. An understanding of the perceived benefits and barriers of consuming a vegetarian diet will allow the implementation of strategies to influence meat and vegetarianism beliefs, dietary behaviour and, hence, public health.
Published:
2003-08
Title:
Dietary intakes and lifestyle factors of a vegan population in Germany: results from the German Vegan Study
Authors:
Waldmann, A.; Koschizke, J. W.; Leitzmann, C.; Hahn, A.
Abstract:
OBJECTIVE: Evaluation of dietary intakes and lifestyle factors of German vegans. DESIGN: Cross-sectional study. SETTINGS: Germany. SUBJECTS: Subjects were recruited through journal advertisements. Of 868 volunteers, only 154 participated in all study segments (pre- and main questionnaire, two 9-day food frequency questionnaires, blood sampling) and fulfilled the following study criteria: vegan dietary intake at least 1 year prior to study start, minimum age of 18 y, no pregnancy or childbirth during the last 12 months. INTERVENTIONS: No interventions. RESULTS: All the 154 subjects had a comparatively low BMI (median 21.2 kg/m(2)), with an extremely low mean consumption of alcohol (0.77+/-3.14 g/day) and tobacco (96.8% were nonsmokers). Mean energy intake (total collective: 8.23+/-2.77 MJ) was higher in strict vegans than in moderate ones. Mean carbohydrate, fat, and protein intakes in proportion to energy (total collective: 57.1:29.7:11.6%) agreed with current recommendations. Recommended intakes for vitamins and minerals were attained through diet, except for calcium (median intake: 81.1% of recommendation), iodine (median: 40.6%), and cobalamin (median: 8.8%). For the male subgroup, the intake of a small amount of food of animal origin improved vitamin and mineral nutrient densities (except for zinc), whereas this was not the case for the female subgroup (except for calcium). CONCLUSION: In order to reach favourable vitamin and mineral intakes, vegans should consider taking supplements containing riboflavin, cobalamin, calcium, and iodine. Intake of total energy and protein should also be improved.
Published:
2003-08
Title:
Dietary intakes and lifestyle factors of a vegan population in Germany: results from the German Vegan Study
Authors:
Waldmann, A.; Koschizke, J. W.; Leitzmann, C.; Hahn, A.
Abstract:
OBJECTIVE: Evaluation of dietary intakes and lifestyle factors of German vegans. DESIGN: Cross-sectional study. SETTINGS: Germany. SUBJECTS: Subjects were recruited through journal advertisements. Of 868 volunteers, only 154 participated in all study segments (pre- and main questionnaire, two 9-day food frequency questionnaires, blood sampling) and fulfilled the following study criteria: vegan dietary intake at least 1 year prior to study start, minimum age of 18 y, no pregnancy or childbirth during the last 12 months. INTERVENTIONS: No interventions. RESULTS: All the 154 subjects had a comparatively low BMI (median 21.2 kg/m(2)), with an extremely low mean consumption of alcohol (0.77+/-3.14 g/day) and tobacco (96.8% were nonsmokers). Mean energy intake (total collective: 8.23+/-2.77 MJ) was higher in strict vegans than in moderate ones. Mean carbohydrate, fat, and protein intakes in proportion to energy (total collective: 57.1:29.7:11.6%) agreed with current recommendations. Recommended intakes for vitamins and minerals were attained through diet, except for calcium (median intake: 81.1% of recommendation), iodine (median: 40.6%), and cobalamin (median: 8.8%). For the male subgroup, the intake of a small amount of food of animal origin improved vitamin and mineral nutrient densities (except for zinc), whereas this was not the case for the female subgroup (except for calcium). CONCLUSION: In order to reach favourable vitamin and mineral intakes, vegans should consider taking supplements containing riboflavin, cobalamin, calcium, and iodine. Intake of total energy and protein should also be improved.
Published:
2003-08
Title:
Evolutionary relationships of Red Jungle Fowl and chicken breeds
Authors:
Moiseyeva, Irina G.; Romanov, Michael N.; Nikiforov, Andrey A.; Sevastyanova, Antonina A.; Semyenova, Serafima K.
Abstract:
Published results were reassessed and original data are provided regarding the origin and relatedness of four postulated chicken breed lineages, egg-type, game, meat-type and Bantam, to each other and to the basic ancestral species of jungle fowls, Gallus gallus. A system approach was employed concerning the planning of the experiments. One element of the system approach is the choice of the breeds to be compared with G. gallus. These breeds were supposed to represent major evolutionary branches of chickens. Four experiments on genetic relationships were conducted using different estimation criteria including morphological discrete characters, body measurements, biochemical markers, and the activity of serum esterase-1. The greatest similarity was found between G. gallus and the egg-type breeds of Mediterranean roots and/or true Bantams. This fact might testify that the indicated chicken groups occupied earlier stages in the evolution from the wild progenitor to the present biodiversity of chickens in the world.
Published:
2003-08
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