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Biomedical subjects

D Kerr

Publications and source records attributed to D Kerr.

At least 37 records · Page 2Linked to original sources
PubMed1989

Adaptation to mild hypoglycaemia in normal subjects despite sustained increases in counter-regulatory hormones.

In diabetes, loss of awareness of and a defective hormonal response to hypoglycaemia have been associated with long disease duration, improved glycaemic control and possibly a change in insulin species. In contrast it is assumed that normal subjects always have symptoms when their blood glucose is low. We have tested this in 7 normal subjects at 3 levels of blood glucose (4.5, 3.5 and 3.0 mmol/l) using a hyperinsulinaemic glucose clamp with a euglycaemic (4.5 mmol/l) clamp as a control. After 60 min at a blood glucose of 3.5 mmol/l adrenaline and glucagon increased slightly but significantly, whereas cortisol, growth hormone and pancreatic polypeptide were unchanged. As soon as glucose was lowered to 3.0 mmol/l adrenaline increased to 1.10 nmol/l and rose further to 1.43 nmol/l after 60 min. Glucagon secretion increased similarly but other counter-regulatory hormones were significantly raised only after 60 min at 3.0 mmol/l. Awareness of hypoglycaemia (symptom score) increased after 40 min at a blood glucose of 3.0 mmol/l but after 60 min decreased to baseline levels with loss of awareness in 5 subjects. Reaction time improved in parallel with the change in symptom score. Thus, despite high levels of adrenaline, normal subjects lose awareness during sustained mild hypoglycaemia. Improved reaction time may reflect cerebral adaptation.

Acclimatization↗
PubMed1989

Influence of duration of hypoglycemia on the hormonal counterregulatory response in normal subjects.

Glucagon and epinephrine are the most important short term glucose counterregulatory hormones. The epinephrine response in patients with insulin-dependent diabetes mellitus is related to the level of glycemic control, but little is known about the factors influencing counterregulation in normal subjects. We, therefore, conducted hyperinsulinemic glucose clamp studies to examine the counterregulatory response to recurrent and prolonged mild hypoglycemia in normal women. Blood glucose was clamped for 20 min at 3.5 mmol/L. Thereafter, the subjects had their blood glucose maintained at 2.8 mmol/L for 90 min and on another occasion lowered to 2.8 mmol/L and raised to 3.5 mmol/L twice during the 90-min period. Continuous hypoglycemia produced augmented plasma glucagon, cortisol, and pancreatic polypeptide responses (all P less than 0.05) compared to these responses to recurrent hypoglycemia. Plasma GH increased, but the magnitude of the response was not altered by the duration of hypoglycemia. During the recurrent hypoglycemia study plasma epinephrine levels rose and fell in parallel with the fluctuations in blood glucose. The mean peak increase was similar [1.37 +/- 0.25 (+/- SE) nmol/L] to that during the continuous study (1.76 +/- 0.23 nmol/L). There was no change in plasma glucagon levels in response to hypoglycemia of less than 15-min duration. We conclude that 1) the duration of hypoglycemia influences the counterregulatory response, and 2) epinephrine release is under precise control and responds rapidly to fluctuations in blood glucose.

Adult↗
PubMed1988

Acquired cutaneous lymphangiectasis in a dog.

A 3-year-old male mixed-breed dog had swelling of the penile sheath, which developed after the dog was castrated at 1 year of age. Physical examination revealed pitting edema and multiple turgid vesicles on the prepuce and inguinal area. Histologic evaluation of the vesicles revealed thin epidermis elevated by dermal proliferation of dilated lymphatic channels. The diagnosis was acquired cutaneous lymphangiectasia. Clinical signs resolved concurrent with furosemide administration. Preputial swelling without vesicles recurred 1 and 2 years later and partially resolved after furosemide administration.

Animals↗
PubMed1988

General practice.

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Family Practice↗
PubMed1988

Mechanisms of parathyroid hormone resistance in pseudohypoparathyroidism.

The problem with PHP is that it is almost certainly a heterogeneous condition encompassing a number of defects within the PTH receptor-adenylate cyclase complex. The clinical manifestations of PTH resistance are amplified and extended by a number of associated abnormalities. These include a low intracellular calcium concentration, secondary hyperparathyroidism, reduced production of 1,25-(OH)2D and perhaps the secretion of an abnormal PTH peptide. Almost every aspect of PTH function seems involved and this makes PHP a fascinating condition in which to test current views of the role of PTH in the integration of the calcium homoeostatic system.

Adenylyl Cyclases↗
PubMed1986

Chromosome change in transitional cell carcinoma of ureter.

Primary transitional cell carcinoma of the ureter is a relatively rare cancer. A case of transitional cell carcinoma of the mid-portion of the ureter in an adult male has been studied cytogenetically and has been found to have trisomy of chromosome #7 (+7) as the only karyotypic abnormality. In an earlier instance of transitional cell carcinoma of the ureter, we observed trisomy 7 together with monosomy 9 and an isochromosome for 5p. The relation of this observation to the cytogenetic findings in transitional cell carcinoma of the bladder is discussed and their possible significance evaluated. The rarity of the cytogenetic findings in these tumors is stressed, as is the possible role played by the chromosomal change in this condition, which may possibly involve the c-erb B oncogene.

Carcinoma, Transitional Cell↗
PubMed1986

A rare case of meningitis due to Neisseria meningitidis group 29E.

We report a case of meningitis due to Neisseria meningitidis group 29E. The organism was serum-sensitive and therefore not expected to be encountered in an immunologically competent young man. Trauma sustained in a road traffic accident 18 months earlier had affected the tympanic membrane and middle ear, allowing direct infection of the meninges. Myringoplasty was performed to prevent recurrent infection.

Adult↗
PubMed1985

Phase I trials of poly(I,C) complexes in advanced cancer.

We have performed Phase I trials of two synthetic double-stranded polyribonucleotide complexes--poly(I,C)-LC, a complex of polyinosinic-polycytidylic acid with poly-L-lysine and carboxymethylcellulose, and poly(I,C)-L, which lacks carboxymethylcellulose--in patients with advanced cancer. With poly(I,C)-LC, several treatment schedules were investigated in an attempt to decrease toxicity and maximize interferon (IFN) induction. The best tolerated was an alternate-day schedule, with gradual dose escalation. Daily short infusions and continuous (24-h) infusions were tolerated less well. Maximum tolerated doses varied over a several hundredfold dose range. Toxicity consisted of fever, rigors, hypotension, and blood count depression. Two patients treated with poly(I,C)-L developed systemic allergic reactions, and antibodies to poly(I,C)-L and its components were detected in the serum of some patients treated with both compounds. IFN-alpha was induced in most patients at serum levels similar to those achieved after intramuscular administration of human IFN-alpha. Of 32 patients, one with renal cell carcinoma showed partial tumor regression. Poly(I,C) complexes are effective IFN inducers in humans, but their toxicity limits their use in cancer patients.

Adult↗
PubMed1985

Intravesical administration of bacillus Calmette-Guérin in patients with recurrent superficial carcinoma of the urinary bladder: report of a prospective, randomized trial.

In an attempt to prevent, delay, or reduce further tumor occurrence, 88 patients with recurrent, superficial carcinoma of the urinary bladder were randomly assigned to receive either standard therapy (cystoscopy with fulguration) or standard therapy and bacillus Calmette-Guérin (BCG). BCG was administered intravesically and percutaneously once weekly for 6 weeks. No serious toxicity was seen. There were 43 evaluable patients in each of the two groups. Results in the BCG group versus the control group were as follows: reduction in the number of recurrent tumors (43 vs 27 patients [P less than 0.001] ); conversion to negative cytology (11 of 33 vs three of 34 patients [P less than 0.05] ); and tumor progression requiring cystectomy (three vs 15 patients [P less than 0.001] ). Disease-free interval (P less than 0.001), time with negative cytology (P less than 0.001), and time to progression of disease (P less than 0.003) were longer in patients treated with BCG. These results indicate that the combination of standard therapy and BCG is more effective than standard therapy alone in patients with recurrent superficial bladder tumors.

Adult↗
PubMed1985

Fluid replacement during hypothermia.

Hypothermia produces acidosis, depressed cardiac function, hypovolemia and hypotension. This study was designed to examine the cardiovascular dynamics involved with restoration of the hypovolemia before rewarming. Mixed breed splenectomized adult dogs (n = 16) were anesthetized with pentobarbital and cooled to a right atrial temperature of 25 degrees C at a rate of 3 degrees C X h-1. The animals were maintained at 25 degrees C for 6 h and rewarmed at 3 degrees C X h-1. Group 1 was given no fluid, Group 2 was given saline (20% of plasma volume infused in 10 min). 2 h after reaching 25 degrees C and Group 3 received saline just prior to rewarming. The hematocrit was elevated in all groups (p less than 0.05) upon cooling, but did not differ between groups even after saline was given. Cardiac output (Co) at 25 degrees C was 35% of precooled values. Group 2 increased their Q by 15% with fluid and this Q was maintained at higher levels than Groups 1 or 3 for the next 4 h. Plasma volume, heart rate, and cardiac contractility returned to control levels upon rewarming, but Q remained low (less than 10%). The level of Q at the start of rewarming did not affect the final level of Q.

Acid-Base Equilibrium↗