Published Science

A 7-month-old male presented with lethargy and failure to thrive. The child was exclusively breast-fed from birth by a mother who was a strict vegetarian. Laboratory data revealed macrocytic anemia and methylmalonic acid in the urine, consistent with vitamin B12 deficient anemia. The patient responded well to supplementation with B12 alone and was developmentally normal by 11 months of age. This study emphasizes the need for assuring maternal dietary adequacy during pregnancy and after birth.

A 7-month-old male presented with lethargy and failure to thrive. The child was exclusively breast-fed from birth by a mother who was a strict vegetarian. Laboratory data revealed macrocytic anemia and methylmalonic acid in the urine, consistent with vitamin B12 deficient anemia. The patient responded well to supplementation with B12 alone and was developmentally normal by 11 months of age. This study emphasizes the need for assuring maternal dietary adequacy during pregnancy and after birth.

Gastrointestinal pH as a function of time was recorded for 4 beagle dogs and 10 human subjects using radiotelemetric pH measuring equipment. Results indicated that in the quiescent phase, gastric pH in the dogs (mean = 1.8 +/- 0.07 SEM) was significantly (p less than 0.05) higher than in humans (1.1 +/- 0.15). No significant difference in the time for the pH monitoring device to empty from the stomach was noted for the two species (99.8 +/- 27.2 min for dogs, 59.7 +/- 14.8 min for humans, p greater than 0.05). The fasting intestinal pH in dogs was consistently higher than in humans, with an average canine intestinal pH of 7.3 +/- 0.09 versus 6.0 +/- 0.14 for humans. The implication of these observations for extrapolation of drug absorption data from dogs to humans are discussed.

Carbohydrate clearance, plaque pH, and saliva pH resulting from eating foods containing high levels of sugar or starch were measured in the same experimental runs on the same test subjects. Foods with a higher content of sugar were removed more rapidly and depressed the pH of the plaque for a shorter time than did starchy foods containing less sugar. This finding suggests that retention of food in the mouth may be as important an indicator of its cariogenic potential as is the level of the pH it produces in plaque.

To determine the effects of very-low-calorie diets on the metabolic abnormalities of diabetes and obesity, we have studied 10 obese, non-insulin-dependent diabetic (NIDDM) and 5 obese, nondiabetic subjects for 36 days on a metabolic ward during consumption of a liquid diet of 300 kcal/day with 30 g of protein. Rapid improvement occurred in the glycemic indices of the diabetic subjects, with mean (+/- SEM) fasting plasma glucose falling from 291 +/- 21 to 95 +/- 6 mg/dl (P less than 0.001) and total glycosylated hemoglobin from 13.1 +/- 0.7% to 8.8 +/- 0.3% (P less than 0.001) (normal reference range 5.5-8.5%). Lipid elevations were normalized with plasma triglycerides reduced to less than 100 mg/dl and total plasma cholesterol to less than 150 mg/dl in both groups. Hormonal and substrate responses were also comparable between groups with reductions in insulin and triiodothyronine and moderate elevations in blood and urinary ketoacid levels without a corresponding rise in free fatty acids. Electrolyte balance for sodium, potassium, calcium, and phosphorus was initially negative but approached equilibrium by completion of the study. Magnesium, in contrast, remained in positive balance in both groups throughout. Total nitrogen loss varied widely among all subjects, ranging from 70 to 367 g, and showed a strong positive correlation with initial lean body mass (N = 0.83, P less than 0.001) and total weight loss (N = 0.87, P less than 0.001). The nondiabetic group, which had a significantly greater initial body weight and lean body mass than the diabetic group, also had a significantly greater weight loss of 450 +/- 31 g/day compared with 308 +/- 19 g/day (P less than 0.01) in the diabetic subjects. The composition of the weight lost at completion was similar in both groups and ranged from 21.6% to 31.3% water, 3.9% to 7.8% protein, and 60.9% to 74.5% fat. The contribution of both water and protein progressively decreased and fat increased, resulting in unchanged caloric requirements during the diet. This study demonstrates that short-term treatment with a very-low-calorie diet in both obese diabetic and nondiabetic subjects results in: safe and effective weight loss associated with the normalization of elevated glucose and lipid levels, a large individual variability in total nitrogen loss determined principally by the initial lean body mass, and progressive increments in the contribution of fat to weight loss with stable caloric requirements and no evidence of a hypometabolic response.

Data on labor time for food production can be used as an effective management tool. It is essential for foodservice managers to know how labor time is being used (1). A continuous time study was conducted to determine total labor time for the production of eight vegetarian entrées in a hospital foodservice system. Two work areas were observed: the ingredient assembly area and the cooks' production area. Times were recorded by work function to identify how labor time was distributed. Results showed (a) observed frequency for each work function, (b) time expended in seconds per portion for each work function, (c) percentage distribution of labor time by work function, (d) total time for each employee involved in entrée production, and (e) percentage of total time in which each employee was involved in the production of each entrée. Total labor time varied by type of entrée, ranging from 39.97 to 19.33 seconds per portion. Entrées with the highest labor time required the largest amount of hand labor. A one-way analysis of variance indicated significant differences in mean labor time among the eight vegetarian entrées for direct labor time (p = .0009), and total labor time (p = .0018). No significant differences were found among entrées for indirect labor or delay time.

Many factors including diet modify the hypothalamic-pituitary axis and menstrual periodicity. We have determined the effect of a daily meat or a soybean supplement in rural vegetarian Black women on the length of the menstrual cycle and the episodic and luteinizing releasing hormone stimulated release of luteinizing hormone. The daily meat but not soybean supplement increased the length of the menstrual cycle (p less than or equal to 0.01), increased the release of LH (p less than or equal to 0.01), and decreased the stimulated release of LH in the luteal phase (p less than or equal to 0.01). These changes are opposite to those reported previously in the Caucasian women fed a meatless diet. Thus addition of meat in the diet modifies the episodic release of gonadotrophins and follicular maturation. The importance of a carbohydrate diet preferentially maintaining CNS-rhythmicity is suggested.

A cognitive model of panic is described. Within this model panic attacks arc said to result from the catastrophic misinterpretation of certain bodily sensations. The sensations which are misinterpreted are mainly those involved in normal anxiety responses (e.g. palpitations, breathlessness. dizziness etc.) but also include some other sensations. The catastrophic misinterpretation involves perceiving these sensations as much more dangerous than they really are (e.g. perceiving palpitations as evidence of an impending heart attack). A review of the literature indicates that the proposed model is consistent with the major features of panic. In particular, it is consistent with the nature of the cognitive disturbance in panic patients, the perceived sequence of events in an attack, the occurrence of ‘spontaneous’ attacks, the role of hyperventilation in attacks, the effects of sodium lactate and the literature on psychological and pharmacological treatments. Finally, a series of direct tests of the model are proposed.

The relationship between dietary fiber consumption and risk of gastrointestinal cancer in humans is examined using representative studies of several types: international and intranational correlations, case-control analyses, metabolic investigations, cohort studies, and migrant studies. The strongest statistical association between diet and cancer is found in international studies in which numerous environmental variables differ. Studies on smaller groups within a single culture have not given strong support to the findings of international comparisons. Colon cancer rates within regions of the U.S. and other countries vary with sufficient magnitude that diet is unlikely to account for more than a minor proportion of risk. The evidence that a diet containing fiber-rich foods reduces risk of colon cancer must be considered tentative. Foods high in starch and fiber are statistically associated with a high rate of stomach cancer. Examination of the combined rates of colon and gastric cancer shows that the U.S. risk is low relative to countries in which a diet higher in fiber is consumed. It would be premature to suggest that a high fiber diet will confer protection against gastrointestinal cancer.

Feeding soy-based protein containing trypsin inhibitor causes pancreatic hypertrophy in the rat, and long-term feeding (up to 2 years) has revealed a high incidence of adenoma following hypertrophy. It was therefore of interest to determine whether the ingestion of soy-based protein has any adverse effects on the primate pancreas. A resource of 27 Cebus albifrons monkeys, previously used to evaluate the protein quality of several soy and milk proteins, has been maintained on semi-synthetic diets for 3 to 4 years; the protein sources for the diets were casein, lactalbumin, soy isolate and soy concentrate. In general the monkeys were in good physical health and their weights were appropriate for age and sex. Serum biochemical and hematological profiles were normal and there were no major differences between the groups. A pancreatic biopsy from both the head and tail region of the pancreas was taken from each monkey. Visual observation of the pancreas revealed no overt pathology; two independent histological examinations indicated no diet-related differences between groups, and biochemical analyses of trypsin, chymotrypsin, protein, DNA and RNA revealed no differences. It is concluded that feeding low level trypsin inhibitor-containing diets for up to 4 years caused no adverse effects in the pancreas of the Cebus nonhuman primate.

Methylglyoxal was found to induce mutations in Salmonella typhimurium strains TA100, TA102 and TA104, gene conversion in Saccharomyces cerevisiae strain D7, and diphtheria toxin resistance mutation in Chinese hamster lung cells. Methylglyoxal was detected in coffee, whiskey, a soft drink, toasted bread and soy sauce. The mutagenicity of methylglyoxal was suppressed by sulfite, cysteine, glutathione and dithiothreitol, and enhanced by hydrogen peroxide. Methylglyoxal induced sarcomas in rats at the site of its subcutaneous injection.

Evidence from Bed I, Olduvai, supports the hypothesis that scavenging, not hunting, was the major meat-procurement strategy of hominids between 2 and 1.7 million years ago. Data used to evaluate the hunting and scavenging hypotheses are derived from studying cut marks on Bed I bovids, comparing adaptations necessary for scavenging with those of early hominids, and a pa-leoecological reconstruction of Bed I carcass biotnass, carnivore guild, and hominidforaging area.

The purpose of this study was to investigate the effect of a vegetarian diet on human fecal neutral sterol excretion. Free and esterified fecal neutral sterols were analyzed by capillary gas-chromatography in healthy North-American white women who were consuming either a mixed Western diet (n = 19) or a vegetarian diet (n = 20). Vegetarians had lower mean concentrations of bacterial metabolites of cholesterol, coprostanol, and coprostanone, and their relative amounts of esterified neutral sterol metabolism in both populations. Most of the subjects in both groups excreted their neutral sterols mainly as metabolites. However, 25% of the omnivores and 21% of the vegetarians had exceptionally low amounts of these metabolites in their feces. The vegetarians in this study differed only slightly from omnivores with regard to intestinal bacterial metabolism of neutral sterols.

The effects of alternative dietary practices on nutrient intake and height/weight status were studied in three groups of Dutch preschool children: 33 vegetarians, 26 anthroposophics, and 33 macrobiotics. Fifty children on omnivorus diets composed the control group. The children fed vegetarian and anthroposophic diets were somewhat lighter and shorter than the children on omnivorous diets but were within normal limits. The children fed macrobiotic diets were significantly lighter and shorter. Results of the 5-day weighing record method used to measure food consumption were compared with the Dutch Recommended Dietary Allowances (RDAs), which recommend higher protein and lower iron for children than the RDAs for the U.S. The diets of the anthroposophically and vegetarian-fed children were most similar and conformed better to the Dutch RDAs than the diets of the omnivorously and macrobiotically fed children. The omnivorously fed children had intakes of iron and polyunsaturated fat below the Dutch RDAs and intakes of mono- and disaccharides and cholesterol above the Dutch RDAs. The intakes of calcium, riboflavin, and vitamin D recorded for the macrobiotically fed children were substantially below the Dutch RDAs. The vitamin D content of the diets of all four groups was low; however, most of the omnivorously fed children used vitamin D supplements, and the other three groups of children were sent out in the sun as much as possible. A high risk for rickets existed in the combination of periods of bad weather and a low intake of both calcium and vitamin D.

The effect on blood pressure of an ovo-lacto-vegetarian (OLV) diet was assessed in a randomized controlled crossover trial. Fifty-eight mild untreated hypertensive subjects recruited from the Perth Centre for the 1983 National Heart Foundation (NHF) Risk Factor Prevalence Survey were randomly allocated to one of three groups: the first maintained their usual diet throughout 12 weeks; the other two were given an OLV diet for either the first or second 6 weeks of the 12-week trial. A significant fall in systolic blood pressure, on average of the order of 5 mmHg, was associated with eating an OLV diet. Blood pressure change was unrelated to change in urinary sodium, potassium or body weight, but was related to initial blood pressures. Although an OLV diet may have an adjunctive role in control of mild hypertension, in view of likely problems with acceptability the dietary components responsible for the blood pressure changes need to be identified.

Radioactive carcinogens have provided most of our present knowledge about the chemistry of interactions between carcinogens and biological systems. The requirement of radioactive carcinogens has restricted carcinogen-DNA binding studies to chemicals that are readily available in isotopically labeled form, i.e., a minute fraction of all potentially mutagenic or carcinogenic chemicals. To extend the scope of carcinogen-DNA binding studies, an alternative method, which does not require radioactive test chemicals, has been developed. In this approach, radioactivity (32P) is being incorporated into DNA constituents by polynucleotide kinase-catalyzed [32P]phosphate transfer from [gamma-32P]ATP after exposure of the DNA in vitro or in vivo to a nonradioactive, covalently binding chemical, and evidence for the alteration of DNA nucleotides is provided by the appearance of extra spots on autoradiograms of thin-layer chromatograms of digests of the chemically modified DNA. Quantitation of adduct levels is accomplished by scintillation counting. The sensitivity of the technique depends on the experimental conditions for 32P-labeling and on the chemical structure of the adducts. Greater sensitivity may be achieved if adducts can be separated as a class from the normal nucleotides. This is the case for an estimated 80% of all carcinogens, giving rise to bulky and/or aromatic substituents in DNA. Under the present conditions, one such adduct in 10(9) to 10(10) normal nucleotides can be detected. A total of approximately 80 compounds has been studied thus far Binding to DNA of rodent tissues was readily detected by the 32P-postlabeling assay for all known carcinogens among these compounds, and adducts were detected in DNA from human placenta of smokers.

To examine the safety of foods (meat and milk) obtained from animals whose feeds were preserved with allyl isothiocyanate (AITC), the authors investigated the status and development of animals, some aspects of protein, lipid and carbohydrate metabolism, some enzymes, hemopoiesis and reproduction function of Wistar rats fed diets containing the above products (55 g dry milk or 50 g boiled meat per 100 g diet). To measure the residual quantity of allylamine (AA), the main metabolite of AITC, a chromato-fluorometric method with the use of dansyl chloride was devised, permitting the detection of 2 ng AA in the spot. The relative standard deviation was 0.14-17. The degree of AA extraction amounted to 96%. The method made it possible to detect the residual quantity of AA in the kidneys (up to 12.2 +/- 2.0 micrograms/kg) and in the liver (up to 83.1 +/- 12.4 micrograms/kg). The data obtained evidence that AA cannot be used as conservant for manufacturing feeds for agricultural animals.

Total dissection of a randomly collected sample of 202 adult and subadult eutherian mammals, combined with site-specific adipocyte volume determination, shows that the number of adipocytes in the body is proportional to (Body Mass)0.74 for predominantly carnivorous species and to (Body Mass)0.78 for mainly herbivorous, nonruminant mammals. Adipocyte expansion or shrinkage, not proliferation or depletion of adipocyte number, is the principal mechanism of adipose tissue enlargement and reduction. Therefore, the adipocytes of large mammals are larger than those of smaller specimens of similar dietary habits and fatness. We suggest that the presence of more numerous, smaller adipocytes in smaller mammals is related to their higher mass-specific metabolic rate. The adipose tissue of mammals with a predominantly carnivorous diet contains 4.6 times as many adipocytes as that of herbivorous nonruminants of similar body mass; but nonruminant herbivores are not necessarily fatter because the adipocytes of carnivorous mammals are proportionately smaller than those of nonruminant herbivores. We suggest that a carbohydrate-based energy metabolism is associated with fewer, relatively larger adipocytes and that when lipids and proteins form the major dietary energy source, adipose tissue consists of a greater number of smaller adipocytes.

We examined the responsiveness of cultured dermal fibroblasts from biopsies of uninvolved and involved areas of skin from six patients with psoriasis to the cell-proliferation-inhibition activity of 1,25-dihydroxyvitamin D3 (1,25-(OH)2-D3). Cultured fibroblasts from age-matched controls responded to 1,25-(OH)2-D3 (at 0.01, 1, 10, and 100 microM) in a dose-dependent fashion, whereas cultured psoriatic fibroblasts from involved or uninvolved skin showed no inhibition of proliferation when exposed to 0.01 or 1 microM of 1,25-(OH)2-D3. However, 1,25-(OH)2-D3 did inhibit proliferation of cultured psoriatic fibroblasts when the concentrations were increased to 10 and 100 microM. An analysis of the 1,25-(OH)2-D3 receptors in cultured psoriatic fibroblasts from uninvolved skin revealed that the Kd, nmax, and sedimentation coefficient were identical to the receptors found in the fibroblasts from age-matched controls. Therefore, cultured psoriatic fibroblasts from involved and uninvolved skin have a partial resistance to 1,25-(OH)2-D3, suggesting that there may be a biochemical defect that is inherent in the dermal fibroblasts of psoriatic patients. Recognition of this defect may provide a new approach for the evaluation of the cause and treatment of this disfiguring skin disorder.

Nutrients that may be deficient in diets of vegetarian infants and preschoolers and that affect growth and development are energy, protein, calcium, iron, zinc, riboflavin, and vitamins B-12 and D. Reasons for these nutrient deficiencies include: limited volumetric capacity of the stomach of infants, toddlers, and preschoolers; low-caloric-density foods eaten by vegans; limited food choices; and restriction of number of meals and snacks eaten by vegan children. Suggestions are made for meeting the energy and nutrient needs of infants and children within the food ways of their families.

The effect of an ovo-lacto-vegetarian (OLV) diet on blood pressure was assessed in a randomized, controlled, crossover trial in 58 mild untreated hypertensive subjects recruited from the Perth Centre for the 1983 NHF Risk Factor Prevalence Survey. Subjects were randomly allocated to one of three groups; the first maintained their usual diet throughout 12 weeks; the other two were given an OLV diet for either the first or second 6 weeks of the 12-week trial. Introduction of an OLV diet was associated with a significant fall in systolic blood pressure, on average of the order of 5 mmHg, which was unrelated to change in urinary sodium, potassium or body weight. It was concluded that a vegetarian diet may have an adjunctive role in control of mild hypertension, but that in view of likely problems with acceptability those dietary components responsible for the blood pressure differences need to be identified.

Many epidemiologists have found a correlation between copper and zinc in the community environment and diseases, such as myocardial and vascular pathologies, and diabetes. The purpose of this study was to investigate the total daily intake of these two metals in cooked food, drinking water and air and their respective levels in blood and urine. A chronobiological methodology has been adopted to establish the reference values of these two metals in biological samples. It has been observed that the daily intake of copper is within the recommended value, whereas its urinary excretion is high. The daily intake of zinc is below the recommended value and its urinary excretion is also high. Both the metals showed a temporal oscillation pattern in blood and urine. A possible chronic zinc deficiency has been anticipated in this particular ethnic group of vegetarian food habit.

Changes in concentrations of minerals, trace elements, protein, lactose and total lipids during 20 mo of lactation and correlations between levels of these milk constituents were studied in a carefully defined set of 222 milk samples collected from 52 women, one-half of whom were vegetarians. Milk samples from vegetarians and those from nonvegetarians contained similar levels of iron, copper, zinc, sodium, potassium, calcium, magnesium, lactose and fat. Following a brief but sharp initial decrease, levels of protein and iron did not change significantly between mo 2 and 20 of lactation. Levels of zinc, copper, sodium and potassium declined for the first 6 mo of lactation. Levels of lipid, sodium and zinc increased during later months of lactation while that of calcium decreased. Levels of lactose, copper, potassium and magnesium remained unchanged during mo 7-20. Stepwise multiple regression analysis showed positive correlations between levels of three pairs of inorganic constituents during the first 6 mo of lactation: copper and zinc, copper and potassium, and potassium and calcium. During the subsequent 14 mo of lactation, potassium was correlated with copper. The level of iron was positively correlated with that of lipid, while that of calcium was negatively correlated with that of lipid. These relationships, and others reported in the paper, are discussed in relation to current hypotheses of the mechanism of milk secretion and the binding of inorganic to organic milk constituents.

We propose the hypothesis that a vegetarian diet reduces the risk of developing diabetes. Findings that have generated this hypothesis are from a population of 25,698 adult White Seventh-day Adventists identified in 1960. During 21 years of follow-up, the risk of diabetes as an underlying cause of death in Adventists was approximately one-half the risk for all US Whites. Within the male Adventist population, vegetarians had a substantially lower risk than non-vegetarians of diabetes as an underlying or contributing cause of death. Within both the male and female Adventist populations, the prevalence of self-reported diabetes also was lower in vegetarians than in non-vegetarians. The associations observed between diabetes and meat consumption were apparently not due to confounding by over- or under-weight, other selected dietary factors, or physical activity. All of the associations between meat consumption and diabetes were stronger in males than in females.

The authors have developed an organ culture system in which segments of rabbit aorta were used for the study of the healing of superficial, intimal injury analogous to that produced in vivo by a nylon monofilament catheter. Aortic segments containing an intact endothelial monolayer were obtained for culture by careful avoidance of the damaging consequences of loss of vascular pressure, vasocontraction, and thrombosis. The segment could be maintained in culture for several weeks. Repair of superficial injury was studied after placing a series of precisely located injuries, 100 mu wide, on each aortic segment over a period of several days. The pattern of healing observed was similar to that observed in vivo. The wounded area was recovered by migrating cells within 24 hours, and during succeeding days these cells underwent a predictable pattern of remodeling which restored the normal morphologic features of the endothelium. The cells within the wound underwent a burst of cell division between 24 and 96 hours after injury and subsequently became quiescent. This organ culture approach potentially allows the investigation of many consequences of endothelial injury in a system which provides far greater control and manipulation of the cellular environment than is possible in vivo.

The amounts of magnesium, zinc, copper, and manganese in 22 health and vegetarian foods and their conventional counterparts were measured. Increased levels of magnesium were associated with the presence of soy in vegetarian and health products. Zinc was low in the vegetarian meat and egg substitutes and in soy milk. Copper tended to be decreased in the vegetarian foods but increased in the health foods relative to levels in the conventional counterparts. Manganese levels were increased in most of the health and vegetarian food items relative to levels in the conventional foods.

Serum concentration of apoprotein A, high density lipoprotein (HDL)-cholesterol and HDL-phospholipids has been studied in thirteen consecutive episodes of diabetic ketoacidosis. In three patients with type I diabetes mellitus HDL2 and HDL3 subfractions were also measured. Patients with type I diabetes showed greatly decreased HDL-cholesterol concentration on admission which increased into the normal range after insulin treatment, while HDL-phospholipids decreased during treatment and apoprotein A remained almost unmodified. In three patients with type I diabetes a virtual absence of HDL2-cholesterol subfraction was observed, which rose to normal values during recovery. Conversely, in type II diabetes mellitus HDL-cholesterol was slightly reduced on admission, and tended to decrease during recovery. These findings imply the existence of abnormalities in the qualitative composition of HDL, and indicate that HDL-cholesterol can fluctuate much more rapidly than previously thought.

During the years 1978-83 four vegetarian children have been admitted to the pediatric departments of Ullevaal and Aker Hospitals in Oslo and Haukeland Hospital, Bergen, with the diagnosis of vitamin D deficiency rickets. One had vitamin B12 deficiency as well. All had been fed a vegetarian diet with some cows' milk, but without vitamin supplementation. All had marked hypocalcemia, and three had tetany or convulsions. All responded well to conventional doses of vitamin D therapy. Two of the mothers had vitamin D deficiency, and one of them also had vitamin B12 deficiency. This report describes the case histories of these children, and also discusses predisposing factors of vegetarian diets for the development of nutritional rickets.

During the years 1978-83 four vegetarian children have been admitted to the pediatric departments of Ullevaal and Aker Hospitals in Oslo and Haukeland Hospital, Bergen, with the diagnosis of vitamin D deficiency rickets. One had vitamin B12 deficiency as well. All had been fed a vegetarian diet with some cows' milk, but without vitamin supplementation. All had marked hypocalcemia, and three had tetany or convulsions. All responded well to conventional doses of vitamin D therapy. Two of the mothers had vitamin D deficiency, and one of them also had vitamin B12 deficiency. This report describes the case histories of these children, and also discusses predisposing factors of vegetarian diets for the development of nutritional rickets.

The role of dietary carbohydrates (CHO) in the resynthesis of muscle and liver glycogen after prolonged, exhaustive exercise has been clearly demonstrated. The mechanisms responsible for optimal glycogen storage are linked to the activation of glycogen synthetase by depletion of glycogen and the subsequent intake of CHO. Although diets rich in CHO may increase the muscle glycogen stores and enhance endurance exercise performance when consumed in the days before the activity, they also increase the rate of CHO oxidation and the use of muscle glycogen. When consumed in the last hour before exercise, the insulin stimulated-uptake of glucose from blood often results in hypoglycemia, greater dependence on muscle glycogen, and an earlier onset of exhaustion than when no CHO is fed. Ingesting CHO during exercise appears to be of minimal value to performance except in events lasting 2 h or longer. The form of CHO (i.e., glucose, fructose, sucrose) ingested may produce different blood glucose and insulin responses, but the rate of muscle glycogen resynthesis is about the same regardless of the structure.

The turnover rates of low density lipoprotein-apolipoprotein B (LDL-apoB) were determined in 32 men with coronary heart disease (CHD) and 11 control men with normal plasma lipids. Thirty patients with CHD had normal levels of LDL-cholesterol (LDL-C); of these patients, 9 had hypertriglyceridemia and 21 had normal plasma lipids. Mean concentrations of total cholesterol and LDL-C were similar among the control subjects and CHD patients, although the latter had significantly lower HDL-C. In control subjects, transport rates and fractional catabolic rates (FCR) of LDL-B were 10.6 +/- 0.5 (SEM) mg/kg-day and 0.31 +/- 0.01 pools/day, respectively. In 10 hypertriglyceridemic patients with CHD, transport rates were 21.7 +/- 1.7 mg/kg-day, and FCRs averaged 0.56 +/- 0.06 pools/day; both were significantly higher than normal (P less than 0.05). Six normolipidemic patients also had abnormally high transport rates of LDL-apoB (19.4 +/- 2.8 mg/kg-day) and FCRs (0.51 +/- 0.03 pools/day); again both were higher than normal. The remaining 16 normolipidemic patients with CHD had normal transport rates (9.9 +/- 0.6 mg/kg-day) and FCRs (0.28 +/- 0.01 pools/day). Thus, hypertriglyceridemic patients with CHD and a portion of normolipidemic patients with CHD were characterized by increases in both transport and fractional catabolic rate of LDL-apoB; these abnormalities in LDL metabolism may have contributed to their coronary heart disease. However, the majority of normolipidemic patients with CHD did not show a distinct defect in their LDL metabolism.

Allometric studies of the brain investigate differences in the size of the total brain or its subdivisions and associate those differences with the size of the organism or, for its parts, with the size of the brain. Two quantitative features are examined in these studies: (1) the intercepts, or how big a part is in relation to the whole, and (2) the slope, or how the two features scale together. Over the past 100 years comparisons of adult vertebrates have demonstrated that taxonomic groups differ according to the amount of brain per body weight and that brain weights do not show as much enlargement as do body weights (negative allometry). Although many studies have covered all vertebrates, only mammalian data will be discussed in this review.

Patterns of size and scaling are an important element in the analysis of fossil catarrhine morphology. Fossil representatives of this group vary substantially in size and in many cases related forms of different size are found in similarly dated strata so that size differences and their consequences become an important element in understanding the adaptive relationships among these forms as well as in establishing ancestor-descendant sequences. The removal or partitioning of the effects of size in morphological data becomes an important element in making correlations between structure and adaptation in fossil specimens.

Size is probably the single most important determinant of body architecture, physiology, ecology, life history, and social organization in mammals. Morphological characteristics associated with each of these broadly defined aspects of structure and function can profitably be studied in relation to size, and none can be fully understood without considering size. Here we outline the relationship of tooth size to body size in frugivorous and folivorous primates. For comparison we shall also consider the relationship of tooth size to body size in insectivorous mammals.

The aim of this chapter is to discover major differences of limb design between primates and other mammals. It is not concerned with qualitative features such as possession of nails or claws, but with quantitative ones, the dimensions of bones and muscles. It is not concerned with differences between primates, but looks for design features shared by primates as a whole, irrespective of body size and taxonomic group.