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Biomedical subjects

K J Thomson

Publications and source records attributed to K J Thomson.

18 recordsLinked to original sources
PubMed1995

Cognitive function during insulin-induced hypoglycemia in humans: short-term cerebral adaptation does not occur.

It has been suggested that cerebral adaptation may occur in response to short-term hypoglycemia. This was examined in the present study by measuring serial changes in cognitive function and symptoms after 60 min of continuous hypoglycemia. Hypoglycemia was induced with a hyperinsulinemic glucose clamp on two separate occasions in 24 non-diabetic human subjects. Cognitive function was assessed using the following cognitive test battery: Paced Auditory Serial Addition Test (PASAT), Rapid Visual Information Processing (RVIP), Trail-Making B (TMB), Digit Symbol Substitution Test (DSST) and Four Choice Reaction Time (CRT). In condition A the blood glucose was maintained at 4.5 mmol/l throughout. On two separate occasions (condition B and condition C) the blood glucose was stabilised at 4.5 mmol/l for 30 min, lowered to 2.5 mmol/l for 60 min and restored to 4.5 mmol/l for 30 min. In each condition the cognitive test battery was performed immediately after stabilisation of blood glucose at 4.5 mmol/l and the subsequent battery was repeated at different time intervals: condition A--after a further 40 min of euglycemia; condition B--after 5 min of hypoglycemia; condition C--after 40 min of hypoglycemia. Acute hypoglycemia induced a significant deterioration in cognitive function which was manifest in all tests except TMB (P < 0.05), but performance ability did not differ between conditions B and C. Symptom scores, assessed by a scaled questionnaire, increased significantly during hypoglycemia (P < 0.001) but no differences were detected between the scores at 30 min and 60 min.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1994

Beta 2-agonists and running economy in prepubertal boys.

Asthmatic athletes (adults and junior) have competed successfully at the highest level for many years assisted by pre-event medication with beta 2-agonists. To examine the impact of beta 2-agonists upon submaximal running economy (oxygen consumption at a given submaximal work load), we studied 10 nonasthmatic boys (age, 10.4 +/- 0.48 years, mean +/- SD). They each completed submaximal (speeds, 7.2, 8.0 and 8.8 km/hr) and peak treadmill running protocols preceded by treatment with beta 2-agonist (terbutaline, 500 micrograms via nebuhaler) or placebo in a randomized, crossover single-blind study. No significant differences were found between running economy and heart rate during the submaximal exercise tests or between peak oxygen consumption (VO2), peak respiratory exchange ratio, peak heart rate (HR), or total running time during the peak VO2 test. Pretreatment with terbutaline did produce small but nonsignificant increases in aerobic fractional utilization (percent peak VO2 on drug: 65.9%, 72.6%, and 76.7% vs. placebo: 65.1%, 70%, and 75.5%), at the three submaximal work loads. Respiratory exchange ratio (RER) values were elevated throughout the submaximal tests (on drug: 0.94, 0.93, and 0.94 vs placebo: 0.91, 0.92, and 0.91, P < 0.05). No significant differences were found between drug and placebo for minute ventilation (VE) and ventilatory equivalent for oxygen (VE/VO2), at both submaximal and peak exercise intensities.(ABSTRACT TRUNCATED AT 250 WORDS)

Administration, Inhalation↗
PubMed1993

Familial cystic nephroma and pleuropulmonary blastoma.

BACKGROUND: Cystic nephroma (CN) and pleuropulmonary blastoma (PPB) are rare tumors without any previously recognized familial association. METHODS: Two cases of CN and one case of PPB in three siblings are reported. RESULTS: A 27-month-old girl and a 31-month-old boy underwent nephrectomy for CN and are free of disease in the contralateral kidney 16 and 14 years later, respectively. Their 28-month-old sister underwent pleuropneumonectomy with postoperative chemotherapy for PPB and died of recurrent disease 9 months later. CONCLUSION: To the knowledge of the authors, these cases represent the first reported familial occurrence of CN and the second of CN and PPB among siblings. The inheritance of a germline mutation predisposing to the development of these tumors is postulated.

Child, Preschool↗
PubMed1993

Chemiluminescent third-generation assay (Amerlite TSH-30) of thyroid-stimulating hormone in serum or plasma assessed.

We assessed the laboratory performance and clinical utility of a new commercial third-generation assay of thyroid-stimulating hormone (TSH), Amerlite TSH-30. The interassay CV was 6% at TSH concentrations of approximately 0.08 mIU/L, and the analytical and functional detection limits of the assay were 0.005 and 0.0125 mIU/L, respectively. Although the assay recovered approximately 96% of TSH International Reference Preparation (TSH-IRP) 80/558 added to serum samples, the endogenous TSH concentrations in basal samples were significantly lower than those found by using two other TSH assays; bias data obtained from thyroliberin stimulation tests suggested that the negative bias found with TSH-30 may be due to the heterogeneity of TSH in basal samples. TSH-30 completely discriminated hyperthyroid and hypothyroid patients from euthyroid ambulatory patients but also detected TSH (> 0.0125 mIU/L) in 3 of 46 untreated hyperthyroid patients. Compared with two second-generation assays, TSH-30 better discriminated between patients with subnormal TSH due to hyperthyroidism, thyroxine overreplacement, and nonthyroidal illness but there was still significant overlap between results for these groups.

Bias↗
PubMed1992

Wellington coroner autopsy cases 1970-89: acute deaths due to drugs, alcohol and poisons.

Coronal autopsy reports attributing deaths to drugs or poisonings were examined for the period 1970-89. There were 239 deaths of which 69% were suicide, 23% were accidental, 4% therapeutic misadventure, and 4% of uncertain category. 10.4% of deaths were due solely to alcohol and alcohol was found in another 13% of deaths from other drugs and poisons [corrected]. Twenty-seven percent of deaths were attributed to carbon monoxide poisoning. Five percent of deaths were due to poisons. Prescription drugs were the cause of deaths in 54% with the principle drug classes being opioids (14%), tricyclic antidepressants (12%), barbiturates (11%), hypnosedatives (8%). Prescribers need to be aware of the interactions of such drugs with alcohol, and to consider safer alternative drugs for those at risk of overdose or drug misuse.

Accidents↗
PubMed1990

The effects of cyclosporin A on glucose homeostasis and the kidney in the normal rat.

The effects of administering cyclosporin A (CsA), for periods of up to 84 days, on glucose homeostasis and renal function were studied in adult male Sprague-Dawley rats. Marked glucose intolerance was demonstrated at a variety of drug doses, accompanied in the longer term by hyperglycaemia. Early on and at high CsA dose, the abnormal islet cell function was accompanied by islet cell vacuolation; in the long-term dose groups, more chronic structural islet changes were present. Although abnormalities in renal function and structure were noted during this study, they were not directly related to the pancreatic changes observed.

Animals↗
PubMed1989

Suicide by band saw.

Suicidal injuries caused by power tools have rarely been reported in the literature. The case of a 37-year-old white male schizophrenic patient who sustained a fatal self-inflicted neck injury from a band saw, while engaging in occupational therapy, is presented. Unusual features of this type of injury as noted at postmortem examination were the extent of the wound, the absence of hesitation injuries, and the presence of grease wipe, bone dust, and sawdust within the wound.

Adult↗
PubMed1989

Renal structure and function in streptozotocin-diabetic rats treated with cyclosporin A.

The effect of cyclosporin A (CsA), administered daily by gavage at 20 mg/kg body weight, on renal structure and function was investigated in normal and streptozotocin-diabetic male adult Sprague-Dawley rats over 12 weeks. In the non-diabetic animals CsA caused a progressive decrease in glomerular filtration rate and increased enzymuria. In contrast, the diabetic state was associated with massive increases in both enzymuria and urine flow rates, but a trend towards increased urea and creatinine clearance rates. CsA treatment of diabetic animals did not significantly alter the above parameters, nor affect circulating glucose levels, and trough serum CsA concentrations were similar in both diabetic and non-diabetic animals. The kidneys from CsA-treated non-diabetic animals showed chronic tubular damage. In the streptozotocin groups, the only morphological abnormality which could be related to diabetes was excess glycogen deposition in distal renal tubules. CsA-treatment of these groups was not associated with structural enhancement of either the drug's nephrotoxicity or the diabetes-related changes. Indeed the results indicate that the diabetic state affords some protection against the functional aspects of CsA-nephrotoxicity.

Animals↗
PubMed1986

Vocal cord paralysis in association with pulmonary emboli.

Recurrent laryngeal nerve palsy and vocal cord paralysis due to mitral stenosis was first described in 1897 (Ortner 1897). Since then other cardiovascular causes, including hypertension, coronary heart disease, aortic aneurysm and congenital heart disease have been described. There are two recorded cases of left recurrent laryngeal nerve palsy due to pulmonary embolism (Albertini 1972; Wilmhurst et al. 1983). We describe what we believe to be the third case.

Aged↗
PubMed1982

Asbestos bodies in the lung: Southampton (UK) and Wellington (New Zealand).

Two series of surgically removed and unselected necropsy lungs were examined for asbestos bodies. In the series from Southampton (UK) 30-mu sections were used and in the Wellington (New Zealand) series a modified Gold's digestion method was used for all cases, together with 30-mu sections for some. A further series of Southampton lungs was assessed by Gold's method six years after the initial study. The 30-mu section technique found asbestos bodies in 13% of Southampton men and none in women: the corresponding Wellington figures were 8% for men and nil for women. In Wellington the more sensitive digestion method found asbestos bodies in 78% of men and 63% of women. In Southampton the investigation by Gold's method found asbestos bodies in 83% of men and 74% of women. No statistically significant association was found between the number of asbestos bodies and the various types of lung carcinoma. The prevalence of asbestos in lungs removed between 1956 and 1965 did not differ significantly from its prevalence in those removed in the late 1970's. There was no significant increase in asbestos after the age of 20.

Adolescent↗
PubMed1977

Classification of glomerulonephritis.

A classification of glomerulonephritis which is being used as a basis for the New Zealand National Study of Glomerulonephritis is presented, together with comments about the salient pathological features of each type of glomerular disease.

Biopsy↗
PubMed1976

Mesangial cell cytoplasm and glomerular disease.

In this study we have examined mesangial cell cytoplasm as seen by light microscopy of plastic embedded renal biopsy material. An assessment of mesangial cell morphology has been made in each of the 350 renal biopsies, and this has been correlated with the disease process. A surprisingly close correlation with the type of disease present was demonstrated. Thus it appears that an increase in mesangial cell cytoplasm correlates with an active process involving the mesangial area. It is suggested that the index of mesangial cell reactivity may be useful in diagnosis of glomerular disease processes.

Cytoplasm↗
PubMed1976

Mesangiocapillary glomerulonephritis with dense "deposits" in the basement membranes of the kidney.

Amongst 125 patients with mesangiocapillary glomerulonephritis (MCGN), 19 showed continuous intramembranous dense "deposits" (IDD). Most were children or young adults. Two patients had partial lipodystrophy. Eleven had a consistently low plasma concentration of C3; only three, however, had an initial low plasma concentration of C4, which rose and then remained normal in two. Tests for the C3 nephritic factor were positive in thirteen patients, and plasma C1q was normal in 8 out of 11 cases investigated. Ten out of twelve (seven of them with low plasma C3) showed C3 deposition by immunofluorescence in the glomerular tuft. This was also demonstrated in some instances in Bowman's capsule and tubular basement membranes. Stains for IgG, IgA, C4 and C1q were negative in all, whereas stains for IgM and fibrin were weakly positive in the glomeruli of three and eight cases repectively. Eight patients went into terminal renal failure over an average of thirty-three months and required hemodialysis or transplantation. MCGN with IDD is an uncommon pattern of renal response to injury, which involves activation of the alternate pathway of the complement system and has a poor short term prognosis. The association with partial lipodystrophy and C3-splitting activity suggests a primary complement abnormality.

Adolescent↗