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Biomedical subjects

R Taylor

Publications and source records attributed to R Taylor.

At least 415 records · Page 23Linked to original sources

Prevalence of anaemia and iron deficiency at different levels of urbanization in Vanuatu.

Mean haemoglobin and plasma iron levels and prevalences of anaemia and iron deficiency were determined in three population samples of Vanuatuans aged 20 or more years as part of a noncommunicable diseases survey in 1985. The three samples were drawn from separate urban, semirural and rural populations. Age-adjusted mean haemoglobin levels were highest in the urban sample and lowest in the rural sample, and plasma iron levels were highest in the urban sample and lowest in the semirural sample. Mean values in each location were generally higher in male subjects than in nonpregnant female subjects. The overall prevalence of anaemia was 10.1% in nonpregnant female subjects and 5.3% in male subjects by World Health Organization (WHO) definitions. These prevalences are lower than those reported for most other developing countries, including some Pacific island nations. Iron deficiency was more prevalent in females than in males (females 17.2%; males 5.0%). Approximately 40% of anaemic subjects were also iron deficient, and there was a significant positive correlation of plasma iron levels with haemoglobin concentration. This suggests that haemoglobinopathies may not be a major cause of anaemia as previously reported. Although most anaemic subjects (88%) had only mild anaemia, in view of the physical lifestyle of rural and semirural Vanuatuans it would be important to optimize haemoglobin levels in these populations.

Adult↗

Knowledge of drug costs: a comparison of general practitioners in Scotland and England.

The implementation of drug budgets will make it essential that general practitioners are aware of prescribing costs. A previous study of general practitioners in Scotland found that their knowledge of drug costs was often inaccurate. At the time of the Scottish study, doctors received very limited information on prescribing costs. By contrast, general practitioners in England have been receiving much more detailed information on their prescribing costs since the introduction of PACT (prescribing analyses and cost) in 1988/89. This study examines whether, as a result, doctors in England are more aware of drug costs. The results suggest that they are not; indeed, doctors in Scotland had marginally better knowledge of drug costs. There is a continuing need to improve the cost information available to general practitioners.

Awareness↗

Increase in glia-derived nerve growth factor following destruction of hippocampal neurons.

It is currently believed that under normal conditions hippocampal neurons synthesize nerve growth factor (NGF) which may provide trophic support for cholinergic neurons projecting from the basal forebrain. The concept that glial cells are mobilized to increase the production of NGF following destruction of hippocampal neurons was examined. Excitotoxin-induced destruction of the dorsal hippocampal neurons resulted in a massive and prolonged increase in NGF-like immunoreactivity (LI). Immunostaining for NGF-LI and the glial marker, glial fibrillary acidic protein (GFAP), revealed that the source of increased NGF-LI production following the lesion were reactive astrocytes. Thus, glial cells assume the role of providing trophic support following loss of target neurons.

Animals↗

Prevalence of diabetes, hypertension and obesity at different levels of urbanisation in Vanuatu.

OBJECTIVE: To determine the prevalence of non-communicable disease, specifically hypertension, diabetes and obesity, amongst populations at different levels of urbanisation in Vanuatu, and to relate the frequency of these conditions to the modernisation of way of life. DESIGN: A cross-sectional population-based comparative study of indicative cluster samples. SETTING: Republic of Vanuatu (south-west Pacific). A relatively undeveloped malarious island country. PARTICIPANTS: Adult (aged greater than or equal to 20 years) Melanesian ni-Vanuatu of both sexes. An occupation-based (civil servants) urban sample (n = 623) and area-based semi-rural (n = 349) and rural (n = 397) samples were employed. Response rates were 78%-92%. INTERVENTIONS: Cases detected were referred for assessment and treatment by local medical staff. MAIN OUTCOME MEASURES: Body mass index, triceps skinfold thickness, blood pressure, plasma glucose (fasting and 2 hours after 75 g glucose), plasma cholesterol and triglyceride levels. RESULTS: Modernity scores confirmed that the three locations represented different levels of acculturation. Prevalences of non-communicable disease were relatively low compared to other Pacific Island communities and industrialised countries. These conditions were nevertheless more common in the urban sample and least common in the rural sample. Non-communicable disease correlated positively with modernity scores and negatively with physical activity scores. Obesity correlated with blood pressure in the urban sample, and there was indirect evidence (urine sodium concentration) of higher salt intake with modernisation. Mean plasma cholesterol levels were lowest in the rural group. CONCLUSIONS: Prevalences of non-communicable disease are relatively low in Vanuatu, although rural-urban differentials are present, and likely to increase with continued development. The evidence presented is consistent with non-communicable disease being related to the modernisation of way of life; specifically: decreased exercise, obesity, and dietary change. Preventive activities should commence now.

Adult↗

Processing of prothrombin in the secretory pathway.

Antibodies raised against plasma prothrombin and the prothrombin propeptide were used to identify prothrombin precursors in rough and smooth microsomes and in the Golgi apparatus. The data demonstrate that the propeptide is part of the prothrombin molecule when undergoing a variety of modifications in the Golgi apparatus. It is shown that these modifications result in an increase in the apparent molecular mass of the prothrombin precursor from 78 kDa in early processing to 83 kDa in late processing. The 83 kDa prothrombin precursor was not recognized by the anti-propeptide antiserum and most likely represents the final product of the precursor in the secretory pathway. Evidence is presented that the propeptide is released from the parent molecule in the Golgi apparatus by a membrane-bound Ca(2+)-dependent serine proteinase(s) with characteristics similar to those of the proalbumin-to-albumin-converting enzyme. Vitamin K-dependent carboxylase activity was measured in membrane fragments obtained from the Golgi apparatus preparation. Sucrose-density-gradient centrifugation and the use of marker enzymes showed that carboxylase activity was highest in fractions enriched in cis-Golgi cisternae. Two different synthetic peptides were used as substrates for the carboxylase. These peptides were from the N-terminal and the C-terminal part of the gamma-carboxyglutamic acid (Gla) region of prothrombin. It is shown that the N-terminal and the C-terminal peptides were preferred as substrates for the carboxylase in the microsomal and the Golgi apparatus preparations respectively. It is also shown that the prothrombin precursor acquires negative charges in the Golgi apparatus that do not result from addition of sugars in late processing. These negative charges could be eliminated by thermal decarboxylation, suggesting that Gla residues may also be synthesized in late processing.

Amino Acid Sequence↗

Do children with severe head injury benefit from intensive care?

Intensive management of severe closed head injury is pursued in most neurosurgical units, as it no doubt reduces mortality. However, the fate of those salvaged from death is less clearly defined. The impact of aggressive management on the psychological recovery is even less clear. This retrospective study of children admitted to a regional paediatric neurosurgical service attempts to address these issues. Eighty-four children between the ages of 3 to 16 years with severe head injuries were studied and categorized according to conservative or intensive treatment groups. The availability of intensive management led to a greater number of such children referred. The mortality in those children sustaining more severe injury, i.e. Glasgow Coma Score (GCS) 3 or 4, was halved (44%) with intensive management from 80% in the conservative group. For those with less severe injury (GCS 5-8), it was unchanged at about 23%. The reduced mortality is at the expense of increased morbidity. Psychological testing showed that the cognitive recovery was comparable.

Adolescent↗

Laser-assisted fibrinogen bonding of vascular tissue.

Characterization of the stress-strain profiles of welded tissue would provide an additional means of analyzing this new technology and comparing it with alternative anastomosing techniques. Rabbit longitudinal aortotomies were repaired with either 7-O polypropylene sutures or an 808-nm diode laser (power density, 4.8 watts/cm2) after topical application of fibrinogen mixed with indocyanine green dye (peak absorption, 805 nm). The rabbits were sacrificed between 0 and 28 days, and the fresh aortic specimens were strained axially in diluted plasma solution until ultimate breakage occurred in order to produce a stress-strain profile graph. No significant differences were noted between sutured and bonded aorta at any time interval. Nonincised aortic tissue (378 lb/in2) withstood significantly higher stress (P less than 0.05) than both sutured (257 lb/in2) and bonded (210 lb/in2) groups at the time of creation. By 7 days after operation, however, no significant differences were noted among any of the three groups. At 28 days after operation, the laser-bonded aorta was significantly stronger than the control aorta (P less than 0.05). The only significant difference in modulus (stretchability) identified the sutured aorta (373 lb/in2) to be more rigid than the control aorta (231 lb/in2) (P less than 0.05). Both sutured and laser-bonded anastomoses are weaker than control aorta initially; however, after an early critical period, both treatments achieve the strength of control aorta. By 1 month postoperatively, sutured anastomoses have the disadvantage of being less distensible.

Animals↗

Impaired activation of skeletal muscle glycogen synthase in non-insulin-dependent diabetes mellitus is unrelated to the degree of obesity.

Twenty-five newly presenting, untreated, white, non-insulin-dependent diabetic (NIDDM) subjects were studied within 72 hours of diagnosis. They were allocated to three groups according to their body mass index [BMI] (lean BMI less than 25.0, n = 9; overweight BMI 25.0 to 30.0, n = 6; obese BMI greater than .30.0 kg/m2, n = 10). All three groups exhibited equivalent hyperglycemia. Eleven normal control subjects were also studied. The degree of activation of skeletal muscle glycogen synthase (GS) was used as an intracellular marker of insulin action, before and during a 240-minute insulin infusion (100 mU/kg/h). Fractional GS activity did not increase in the lean (change, -0.9 +/- 3.3%), the overweight (-1.9 +/- 2.7%), or the obese (+2.2 +/- 1.6%) NIDDM subjects during the insulin infusion and was markedly decreased compared with the control subjects (change, +14.6 +/- 2.4%, all P less than .001). Glucose requirement was also significantly decreased in all three NIDDM groups (103 +/- 23 v 81 +/- 14 v 53 +/- 14 mg/m2/min, respectively) compared with the control subjects (319 +/- 18 mg/m2/min, all P less than .001). There was a significant negative correlation with BMI (r = -.51, P less than .01), but the difference in glucose requirement between the lean and obese NIDDM groups was not significant. Muscle GS activity at the end of the euglycemic clamp correlated with glucose requirement (r = .53, P less than .001), and a similar correlation was observed between the insulin-induced change in muscle GS activity from basal and glucose requirement (r = .47, P less than .005).(ABSTRACT TRUNCATED AT 250 WORDS)

3-Hydroxybutyric Acid↗

Cutaneous metastasis from papillary carcinoma of the thyroid gland.

Cutaneous metastases from carcinoma of the thyroid gland are rare. We present the clinical, histologic, and immunohistochemical features of a solitary metastasis from papillary carcinoma of the thyroid. Our results indicate that this tumor can produce epithelial mucin and, therefore, must be differentiated from other metastatic carcinomas and from primary apocrine tumors of the skin. Positive staining for thyroglobulin confirmed the diagnosis in this case.

Carcinoma, Papillary↗

Cancer incidence in New South Wales, Australia.

In 1972, cancer registration began in New South Wales (NSW), the most populous state in Australia. The operations of the Registry are described. By 1990, approximately 316,000 new cases of cancer had been notified from a population that had increased from 4.6 to 5.8 million. In 1981-1984, the most common sites in men were lung, prostate, colon, melanoma and bladder, and in women, breast, melanoma, colon, lung and unknown primary site. Cancers which, between 1973-1976 and 1981-1984, had increased in reported incidence by more than 25% were pharynx and kidney in both sexes, rectum, testis and melanoma in men, and lung and bladder in women; those decreasing by more than 10% were stomach in both sexes, oesophagus in men and cervix in women. Age-standardised incidence rates for melanoma (27.4 [m] and 23.8 [f] per 100,000 in 1987) and cancer of the renal pelvis in women (1.7 per 100,000 in 1989) are among the highest in the world.

Age Factors↗

Liposarcoma arising in the cheek: report of a case and review of the literature.

The following points can be made about liposarcoma of the oral cavity: 1) it is rare and slow growing; 2) it is often mistaken for a benign lesion; 3) there is a direct correlation of microscopic appearance with biological behavior and prognosis; 4) treatment is primarily surgical, with radiation used for selected cases; and 5) the better-differentiated tumors seem to respond more favorably to radiation.

Cheek↗

An evaluation of the Deltatrac indirect calorimeter by gravimetric injection and alcohol burning.

We evaluated a 'state of the art' open hood type of indirect calorimeter (Deltatrac, Datex) to determine its stability and precision, and related these to in vivo measurements made with the same type of calorimeter. Three Deltatrac Metabolic Monitors were investigated at two centres over a period of twelve months by two methods of recovery: (i) gravimetric injection of a nitrogen/CO2 gas mix and (ii) ethanol burning using the manufacturers approved apparatus. We compared machine variation with in vivo variation in measurements of oxygen uptake and carbon dioxide production at rest in healthy subjects. The Deltatrac recovery of both oxygen and carbon dioxide was on average 4.8% and 4.7% higher respectively for the alcohol burning method. We suspected that this apparent over-recovery was because the alcohol burner produced a resistance to the airflow generated across the canopy. By gravimetrically injecting the gas mix into the canopy hose whilst the alcohol burner was attached we were able to confirm this error. There was no significant change in recovery for any of the Deltatracs by either method over the year of evaluation. The between-study variation for the machine and in vivo measurements were less than 4%, and the within-study variations were less than 6% and less than 7%, respectively. These studies re-emphasise that careful evaluation of commercially produced indirect calorimeters is essential before clinical measurements are made.

Calorimetry↗

Review: deterioration of glucose tolerance with age: the role of insulin resistance.

Glucose tolerance is determined by the balance of insulin secretion and insulin action and deteriorates with age. Insulin secretion does not appear to be reduced with increasing age, but many recent studies have demonstrated insulin resistance in healthy elderly subjects. However, this has not been a universal finding and the reasons for the discrepant results probably include general health, physical training, changes of liver size and delays in carbohydrate absorption. When confounding factors, particularly physical activity, are taken into account there appears to be little or no change in insulin action with age. Delays in monosacharride absorption may play a role. Maintaining physical fitness throughout middle and older age and so reducing hyperinsulinaemia may have benefits on reducing vascular disease.

Administration, Oral↗