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Biomedical subjects

R W Henry

Publications and source records attributed to R W Henry.

54 records · Page 3Linked to original sources
PubMed1983

Failure of fasting to influence the GIP response to oral glucose in non-obese human subjects.

The plasma GIP response to an oral 50 g glucose tolerance test has been compared in eight non-obese human subjects after 12 and 36 h of fasting. Basal plasma GIP and basal plasma insulin concentrations were similar after 12 and 36 h of fasting. Basal blood glucose was lower after 36 h fasting than after 12 h fasting (p less than 0.0125). After 36 h fasting the oral glucose tolerance test stimulated higher blood glucose concentrations at 60, 90 and 120 min (p less than 0.0125) and higher plasma insulin concentrations at similar time points (p less than 0.05), but stimulated plasma GIP concentrations were similar after 12 and 36 h fasts. These findings show that the increased insulinotrophic effect of oral glucose after 36 h fasting in non-obese subjects is not due to an associated augmentation of the glucose-induced GIP response.

Adolescent↗
PubMed1982

Selective emergence of differentiated chondrocytes during serum-free culture of cells derived from fetal rat calvaria.

Cells dispersed from the chondrocranial portions of fetal rat calvaria proliferated and performed specialized functions during primary culture in a chemically defined medium. Mature cultures were typified by multilayered clusters of redifferentiating cartilage cells. Flattened cells that lacked distinguishing features occupied areas between the clusters. Alkaline phosphate-enriched, ultrastructurally typical chondrocytes within the clusters were encased in a dense extracellular matrix that stained prominently for chondroitin sulfate proteoglycans. This matrix contained fibrils measuring 19 nm in diameter, which were associated with proteoglycan granules that preferentially bound ruthenium red. A progressive increase in the number of cells indicated the proliferation of certain elements in the primary culture. The cells in primary culture were biochemically as well as morphologically heterogeneous since they were found to synthesize type I and type II collagens. Homogeneous populations of redifferentiated chondrocytes were recovered as floating cells and were shown to express the chondrocyte phenotype in secondary culture. Subcultured cells synthesized type II collagen and its precursors almost exclusively and incorporated 35SO4 into proteoglycan monomer and aggregates to a greater degree than the cells in primary culture. The pattern of proteoglycan monomer and aggregate labeling resembled that of intact cartilage segments and bovine articular chondrocytes. Skin fibroblasts harvested from the same rat fetuses failed to proliferate when maintained under identical conditions. Hence, exogenous hormones, growth factors, and protein are not required for chondrocyte growth and maturation.

Animals↗
PubMed1982

Transoral hypophysectomy with mandibular symphysiotomy in the dog.

A surgical approach that offered direct visualization and removal of the hypophysis was evaluated in 17 dogs. Ten of the dogs were euthanatized and used to identify reliable landmarks for the drill site in the basisphenoid bone to expose the hypophysis. The intersphenoidal suture was an accurate landmark in that 1 cm caudal to the intersphenoidal suture was determined to be the precise point for the center of the drill hole. The remaining 7 dogs were hypophysectomized, using this approach. The landmarks were accurate, the surgery had a high degree of safety, and all hypophyses were removed.

Animals↗
PubMed1981

The gastro-entero-pancreatic hormone response to fasting in obesity.

A comparison of the metabolic and gastroentero-pancreatic hormonal responses of ten obese and eight lean subjects to 12 h and 36 h fasts has been made. Each subject was given a 50 g oral glucose tolerance test at the end of both 12 h and 36 h starvation. After the 12 h fast blood glucose and 3-hydroxybuty-rate were similar in each group but blood glycerol was 30% higher in the obese subjects. Plasma insulin and vaso-active intestinal polypeptide were also higher in the obese subjects after 12 h starvation. After 36 h starvation in the lean subjects blood glucose was unchanged but on refeeding with 50 g oral glucose, glucose tolerance was impaired. In the same group blood glycerol and 3-hydroxybutyrate rose after 36 h starvation. Plasma glucagon, secretin and vaso-active intestinal polypeptide rose after 36 h starvation in the lean subjects but plasma insulin was unchanged. Refeeding with oral glucose suppressed the increased plasma glucagon, secretin and vaso-active intestinal polypeptide. After the 36 h fast in the obese subjects, blood glucose was unchanged, blood glycerol fell, but blood 3-hydroxybutyrate rose although to a reduced level in comparison with the lean subjects. In the obese group there was no change in plasma glucagon, secretin or vaso-active intestinal polypeptide after 36 h starvation, although plasma insulin fell. The results show different metabolic and gastro-entero-pancreatic hormonal responses to fasting in lean and obese human subjects and suggest an important metabolic role of glucagon, secretin and vaso-active intestinal polypeptide during starvation.

3-Hydroxybutyric Acid↗
PubMed1981

Proximal equine radial and median motor nerve conduction velocity.

Radial and median motor nerve conduction velocities were determined on 10 clinically healthy 1- to 11-year-old ponies. These velocities were obtained by stimulation at the brachial plexus directly through a surgical incision and later in the ambulatory pony via implanted Formvar-coated wire electrodes. Percutaneous stimulation was used at the cubital region in both anesthetized and ambulatory ponies. The values for radial motor nerve fibers ranged from 96.4 to 100 m/s. These were 15.3% faster than previously reported distal values. Median motor nerve fiber values ranged from 86.8 to 90.2 m/s, which were 14.9% faster than distal velocities. These data showing proximal velocities in the equine to be faster than distal velocities were similar to reported data for persons and dogs.

Animals↗
PubMed1979

Starvation-induced changes in secretin-like immunoreactivity of human plasma.

Levels of secretin-like immunoreactivity in the plasma of 50 starved subjects were measured by radioimmunoassay and rose from 18 +/- 3 (S.E.) pg/ml after 12 h, to 103 +/- 12 pg/ml (P less than 0.005) after 36 h. The assay antibodies were found to be specific for a region of secretin located towards the C-terminal residue. Lactoperoxidase was used to label the secretin with 125I and ionexchange chromatography on SP-Sephadex C-25 was used to purify the labelled product. The plasma immunoreactivity was purified by immunoaffinity chromatography on antibody-Sepharose conjugates and characterised by gel-filtration on Sephadex G-50 calibrated with molecular weight markers. After a 12-h fast, 10-20% of the immunoreactivity had a molecular weight of about 12 000, possibly due to precursors of secretin. Most of the remainder was smaller than secretin with molecular weight of less than 3000. This material comprised over 90% of the plasma immunoreactivity after a 36-h fast and may be due to degradation products.

Antibody Specificity↗
PubMed1979

The gastro-entero-pancreatic hormone secretion after a mixed meal in normal subjects before and after a 72 hour period of starvation.

The responses of plasma gastro-entero-pancreatic (GEP) hormones and free fatty acids (FFA) to a standard mixed meal before and after starvation have been measured. Raised insulin, glucose and FFA levels were found following refeeding after starvation and levels of secretin and C-terminal glucagon-like-immunoreactivity (C-GLI), raised by starvation, were rapidly suppressed on refeeding. The responses of gastrin and N-terminal glucagon-like-immunoreactivity (N-GLI) to a standard mixed meal were not altered by starvation. Although this study does not directly support that secretin and glucagon are responsible for the hyperglycaemia or hyperinsulinaemia of starvation diabetes, a role for both hormones in the raised FFA levels is proposed, as well as a role for glucagon in the initial hyperglycaemic response to a meal after starvation.

Adult↗
PubMed1979

Evaluation of equine radial and median nerve conduction velocities.

Eleven ponies and 13 horses were used to develop a technique for determining conduction velocity for the radial and median nerves and establishing normal limits for these values. One pony was euthanatized to determine the course of the radial and the median nerves. From this dissection, both proximal and distal stimulation sites for the radial and the median nerves were selected, as well as areas for recording muscle evoked responses from the abductor digiti I longus (extensor carpi obliquus) and the radial head of the deep digital flexor muscles. The other ten ponies and the horses were used in studies on the stimulation of the nerves and recording of muscle evoked responses from which conduction velocity could be calculated. Conduction velocities for the radial and the median nerves were calculated and recorded.

Animals↗
PubMed1977

Surgical approach to the equine brachial plexus.

Eleven ponies were used to perfect a surgical approach to the brachial plexus that would offer maximal exposure to the plexus, with minimal trauma. One pony was euthanatized to determine whether surgical exposure to the plexus was feasible. By approaching the plexus from the prescapular region, the only muscle that was found necessary to incise was the cutaneus omobrachialis. The rest of the procedure required only blunt dissection. In the other 10 ponies, the wounds healed by first intention, and the gait was not affected by the surgery.

Animals↗
PubMed1976

Triglyceride metabolism in acute starvation: the role of secretin and glucagon.

Plasma lipid and hormone levels have been measured during 72 hours total starvation in nine healthy subjects, to assess the relative importance of hormones and substrates in human triglyceride metabolism. Plasma free fatty acid and glycerol concentrations rose steadily on each day of starvation. Plasma triglyceride concentrations rose on the second and third days, from a control level of 649 +/- 67 mg/1 to a maximum of 1001 +/- 66 mg/1. Plasma cholesterol concentrations remained unchanged while glucose concentrations fell and insulin did not change. Plasma glucagon (C-GLI) levels doubled while secretin levels, reported previously, rose threefold. It is suggested that during acute starvation the rise in triglyceride concentration results from the increased availability of free fatty acids, and that elevated secretin and glucagon levels enhance lipolysis and hence provide substrates for triglyceride synthesis.

Adult↗
PubMed1975

Secretin: A new role for an old hormone.

Plasma-secretin levels were measured by radioimmunoassay during a 72-hour starvation period in nine healthy subjects. Immunoreactive secretin (I.R.S.) levels rose dramatically during starvation. The rises were several orders of magnitude greater than those after intraduodenal acid. The classic concept that the major function of secretin is the control of the exocrine pancreas is challenged by these results. The findings suggest that secretin is a hormone of importance during starvation, and its role in starvation may be related to its lipolytic properties.

Adult↗