Showing papers by "University of Vermont published in 1973"

Endocrine and metabolic effects of experimental obesity in man.

Abstract: Publisher Summary This chapter discusses the endocrine and metabolic effects of the experimental obesity in humans. All the changes witnessed in spontaneous obesity except for the increase in adipocyte number have been reproduced in experimental obesity. It has been found that endocrine and metabolic changes are associated with gain in weight. Normal subjects fattened by eating a mixed diet require more calories in relation to their body surface area for maintenance of the obese state than they require when at their natural weight and also more than the spontaneously obese generally require. There are marked differences in the ability of normal individuals to gain weight by taking calories in excess of those required for maintenance. When weight is gained by normal increase in the intake of fat alone, there is a higher proportion of weight gained to calories ingested, and the weight gained may be maintained by an intake that is no greater than that required to maintain the initial weight. The chapter also describes the hormonal and circulating factors that affect the resistance to insulin in experimental obesity. It also presents evidence for cellular factors in resistance to insulin in experimental obesity and their response to gain in weight and to dietary carbohydrate.

Ethanol inhibits Intestinal Calcium Transport in Rats

Abstract: ALTHOUGH it is known that intestinal calcium malabsorption may occur in chronic alcoholic patients indirectly as a result of steatorrhoea of multiple causes1–7, producing inadequate absorption of fat-soluble vitamin D, little attention has been paid to possible direct effect on small intestinal transport. To test that possibility, I starved male albino rats 8 h before and 18 h after the acute administration of ethanol (7.5 g kg−1 body weight) or isocaloric glucose (13.7 g kg−1; they were, however, permitted free access to water. Chronic ethanol ingestion was achieved by giving 20% ethanol in water as a sole source of fluid and standard laboratory chow was fed ad libitum for 12 d. Comparisons were made with ad libitum and pair-fed controls. Calcium transport by duodenum and ileum was measured using an in vitro everted gut sac technique8.

Patulin Production in Apples Decayed by Penicillium expansum

Abstract: Sixty isolates of Penicillium expansum were tested for patulin production in decaying apples. All the isolates were found to produce the mycotoxin patulin as determined by thin-layer chromatography. Since patulin is known to be stable in many apple products, the results indicate that apple products made partially from apples decayed by P. expansum will contain patulin which may present a health hazard. The results also suggest that patulin may be important in the decay of apples by P. expansum.

The Amygdala: Historical and functional analysis

Abstract: The amygdala, part of the limbic system, is a small collection of neurons located in the ventral temporal lobe, and can be divided into two morphologically and functionally distinct nuclei - the corticomedial, a phylogenetically old group, and the basolateral, a phylogenetically more recent group Both divisions of the amygdala have extensive interconnections with the hypothalamus, the corticomedial nucleus via the stria terminalis and the basolateral nucleus via the ventral amygdalohypothalamic pathway The amygdala receives input from the orbital frontal cortex, the piriform cortex, the hypothalamus, the thalamus, and all sensory modalities as well as from the other structures of the limbic system Early theories positing strictly emotional, olfactory, or visceral functions for the amygdala are at best incomplete An intact amygdala seems to be essential for the successful performance of behavior patterns such as instinctive food getting and instinctive defensive reactions that are necessary for the survival of the individual organism and the species Ablation of the amygdala produces many behavioral deficits that center around the inability to integrate changes in reinforcement contigencies into new behavior patterns

Control of Their Environment Reduces Emotionality in Rats

Abstract: Rats reared from birth in a "contingent environment" in which they controlled lighting conditions and the delivery of food and water were compared as adults to rats reared in an environment in which they received the same food, water, and lighting conditions, but without control over their occurrence. Rats reared in the contingent environment were less emotional, as judged by activity and defecation scores in open-field testing.

Absorptive defects in young people with regional enteritis.

Abstract: Eleven patients with Crohn9s disease between 8 and 21 years of age were evaluated to document the incidence and severity of correctable nutritional deficiencies in young people with this disorder. Studies included common hematological and electrolyte determinations, complete gastrointestinal barium studies, assessment of d-xylose, vitamin B12 and fat absorption, and quantification of intestinal protein loss. A variety of abnormalities was found. Subnormal weight, diffuse disease radiologically, anemia, low serum iron, and excessive protein loss occurred in eight patients. Vitamin B12 malabsorption and hypoproteinemia occurred in six, and steatorrhea and hypocalcemia were detected less often. The frequent occurrence of these abnormalities warrants careful monitoring of children with Crohn9s disease for absorptive defects which are amenable to corrective or palliative treatment.

Determination of acoustic power outputs in the microwatt-milliwatt range

Abstract: A system using an electrobalance for radiation pressure measurements has been developed capable of determining acoustic powers in the microwatt-milliwatt range. Low background “noise” levels are achieved by effective isolation of the balance from building vibrations and shielding the target from convection currents. The standard deviation for a power output of 1 mW is typically less than 1 percent.

Studies of a marine grass, thalassia testudinum. i. ultrastructure of the osmoregulatory leaf cells

Abstract: A B S T R A C T Thalassia testudinum (Turtle Grass), a marine monocot which grows completely submerged, differs from intertidal and other halophytic angiosperms in that it has no specialized saltsecretory glands. Osmoregulation appears to be accomplished by the epidermal leaf cells which have highly invaginated plasmalemmas with numerous mitochondria situated in the interdigitations. The ultrastructure and proposed mode of secretion are similar to that of the salt-marsh monocot Spartina, but differ from that found in dicots. Evidence is presented to show why monocots are the only angiosperms which have adapted to a completely marine environment. OF ALL VASCULAR PLANTS only certain monocotyledons can survive completely submerged in salt water. Both monocots and dicots live in freshwater habitats, and both are found as intertidal species. The most obvious difference between a

Delayed hemolytic transfusion reactions.

Abstract: Delayed hemolytic transfusion reactions continue to occur in spite of the use of all of the currently available techniques of antibody detection. Both low titers of the antibodies and dosage effects appear to contribute to the failure of detection. A rapid anamnestic response can occur with transfusion of the appropriate antigen. The clinical as well as the laboratory presentation of delayed hemolysis may vary from case to case and thus confuse the true nature of the reaction. The Kidd antibodies are, as a group, more frequently reported in delayed reactions than are any other antibodies.

Nonuniform rates of turnover of myofibrillar proteins in rat diaphragm.

Abstract: In recent years m u c h information has been gained on the s t ructure of the contracti le proteins in muscle and of the myofibril. Relat ively little, however, has been learned concerning the assembly and turnover of this organelle in l iving str iated muscle. The present studies were undertaken to de termine whether in the adul t an ima l the myofibril turns over as a uni t or whether the individual myofibri l lar proteins are synthesized and degraded at different rates. In embryonic muscle, there is s t rong evidence tha t the various contracti le proteins are synthesized at distinct rates (1) on separate polysomes (2, 3) and tha t they even first appea r at distinct times dur ing embryogenesis (3, 4). Previous studies of the turnover of the myofibril in adul t muscle have been inconclusive. Two groups have reported tha t heavy meromyosin, l ight meromyosin, actin, and t ropomyosin are synthesized and degraded at different rates in vivo (5, 6). Others, however, have suggested tha t the myofibril has a definite life-span (7, 8). We have used the ra t d i a p h r a g m main ta ined in vitro and measured the ra te of incorporat ion of labeled acids into actin, t ropomyosin, an d the heavy and l ight chains of myosin. T h e present studies indicate nonuni form rates of synthesis of the contracti le proteins, and thus suggest heterogeneous rates of degradat ion.

Experimental Obesity in Man. III. Adrenocortical Function

Abstract: Several indices of adrenal function were studied in normal lean males who gained weight by overeating. In 9 subjects, cortisol production rates were increased after weight gain (p < 0.05). The pattern of conversion of cortisol to various metabolites was unchanged following gain in weight. In an additional 5 subjects, urine 17-hydroxycorticosteroids (17-OHCS) were also increased after weight gain (p < 0.06), and plasma cortisol concentrations were unchanged. When cortisol production rates and 17-OHCS excretion were related to body weight or creatinine excreted, the increase in adrenocortical function is not significant. It is concluded that the increased adrenocortical function observed in spontaneous obesity can be reproduced in normal subjects who gain weight by overeating. However, in these studies, we cannot dissociate the effects of gain in weight from those of increased caloric intake or change in the composition of the antecedent diet.

Action potential and contraction of heart muscle

Abstract: Current concepts of the mechanisms responsible for the cardiac action potential are reviewed, as are the relations between the electrical activity and cardiac contraction. The development of techniques allowing direct control of the membrane voltage of cardiac cells has led to a rapid increase in our understanding of the cellular basis of cardiac electrophysiology. There appear to be 8 separately identifiable ionic channels that interact to produce the distinctive cardiac action potential. These “voltage clamp” methods also provide a new approach to the study of excitation-contraction coupling in heart muscle. The application of these methods has led to several new ideas about the relation between membrane voltage and contraction. In addition to triggering contraction, the cardiac action potential plays an important role in the control of contraction, and the nature of this electrical control is examined.

Two types of pyruvate kinase in schistosomes and filariae.

Abstract: 1. 1. Pyruvate kinase (PK) from the trematode Schistosoma mansoni closely resembles PK from rabbit muscle in its response to various purine and pyrimidine nucleoside diphosphates and divalent cations, in its insensitivity to activation by FDP and relative insensitivity to inhibition by ATP and in its somewhat higher affinity for PEP. 2. 2. PK's from the filarial nematodes Litomosoides carinii and Dirofilaria immitis closely resemble PK from rabbit liver in the pattern of their substrate and cofactor specificities, by being strongly activated by FDP and inhibited by ATP, and by showing a relatively lower affinity for PEP. 3. 3. The properties of PK from S. mansoni miracidia were indistinguishable from those of PK from the adult forms, and this was also the case for the PK's from D. immitis microfilariae and adults. 4. 4. The molecular weights of PK's from S. mansoni , D. immitis and rabbit muscle were all around 270,000±10 per cent.

Peripheral circulatory response to phototherapy in newborn infants

Abstract: Summary Calf blood flow (CBF), calf skin temperature, incubator wall and ambient temperature, and respiratory rate, were measured in 8 newborn infants 10 to 127 hours of age, who were treated by phototherapy because of jaundice. During phototherapy (within 30 min) the CBF increased to a range of 30 to 80% above the control values of 8.8 ± 0.9 ml/min/100 g. The CBF is correlated directly with the leg skin temperature (γ= 0.724 and 0.588 at 15 and 30 min after phototherapy respectively). The increase in CBF was associated with a fall in incubator ambient temperature, the latter is a result of the use of servo control unit in monitoring incubator temperature by epigastric skin temperature. The increase in CBF is probably evidence of peripheral vasodilatation to facilitate evaporative heat loss. An increase in respiratory rate was also observed during phototherapy. The observed increase in heat loss (and water loss) from vasodilatation and increased respiratory rate serve as a basis for the increase in insensible water loss as previously reported.

Carpal-Tunnel Syndrome in Patients with Myxedematous Arthropathy

Abstract: Five patients with carpal-tunnel syndrome and with typical signs and symptoms of myxedema were found in a review of the forty-nine patients with carpal-tunnel syndrome seen in a decade at our clinic. To these were added three more such patients from a rheumatologic practice. The eight patients were treated with thyroid replacement and their carpal-tunnel syndromes disappeared while thirty-six of the other forty-four patients required surgical treatment.

Effects of alcohol and fixation-task difficulty on choice reaction time to extrafoveal stimulation.

Abstract: Alcohol and concurrent foveal-task difficulty increased choice reaction time to extrafoveal stimulation; in combination their influence was additive.

Scanning electron microscopy of the human cerebral ventricular system. II. The fourth ventricle.

Abstract: Scanning electron microscopy was used to assess the ultrastructural differences exhibited by the varigated ependymal lining of the near-term human fetal 4th ventricle. The central portion of the fourth ventricular floor, including the median sulcus is punctuated by numerous clumps of cilia. The density of cilia here is not as great as that described for other regions of the human cerebral ventricular system; accordingly, underlying substructure can be noted. There are distinct differences between ependymas that line the floor of the fourth ventricle with those of the adjacent area postrema. The latter region possesses not cilia, but instead exhibits a dense knap of microvilli. The ultra-architecture of the choroid plexus is relatively similar to that of other circumventricular organs with the exception that it possesses small isolated groups of cilia as well as microvilli. These findings are discussed with respect to the dynamics of local CSF movement and flow, ependymoabsorption and ependymosecretion

Immune Enhancement of Pulmonary Bactericidal Activity in Murine Virus Pneumonia

Abstract: Bacterial multiplication in the lung associated with murine Sendai virus pneumonia is caused by virus-induced defects in pulmonary bactericidal mechanisms. The nature of this effect has been studied in animals immunized against the challenge bacteria. Mice were immunized against Proteus mirabilis by intraperitoneal inoculation and by aerosol inhalation. After the development of immunity, mice were infected aerogenically with 10(4) TCID(50) of Sendai virus. 7 days later, during the height of the bronchial inflammation and pulmonary consolidation, the mice were challenged with an aerosol of viable (35)S-labeled Proteus mirabilis or (32)P-labeled Staphylococcus aureus.Nonimmunized virus-infected animals showed marked impairment of pulmonary bactericidal activity with subsequent multiplication of the bacterial strain in the case of Proteus mirabilis. Immunized nonvirus-infected animals showed enhancement of pulmonary bactericidal activity for the homologous and heterologous strains in comparison with nonimmunized animals. Virus-infected animals immunized by aerosol showed enhanced bactericidal activity against the homologous but not the heterologous bacterial strain. Neither virus infection nor immunization had a significant effect on the transport of particles in the lung. The data demonstrated that the bacterial multiplication associated with the virus pneumonia was prevented by preceding immunization against the homologous challenge organism. The data suggest a mechanism for controlling bacterial multiplication associated with virus pneumonias.

Fracture of the calcaneus in young children. Report of three cases.

Abstract: Fracture of the calcaneus was noted in three children, aged sixteen, twenty-seven, and thirty months, a total of 6 per cent of the calcaneal fractures seen at the Medical Center Hospital of Vermont in ten years. The importance of careful examination, observation of characteristic posturing, and the value of roentgenograms in several projections is stressed, since such fractures are easily overlooked.