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Biomedical subjects

P J Becker

Publications and source records attributed to P J Becker.

At least 127 records · Page 7Linked to original sources
PubMed1989

Parotid tumours in black patients. The Baragwanath Hospital experience, 1981-1986.

Parotid tumours are rare, but their diagnosis and management continue to be a surgical challenge. In a retrospective review of 60 patients over a 6-year period, the value of clinical features in distinguishing malignant from benign parotid tumours was examined. The sex of patients, the consistency, size and site of tumour, smoking, length of history and rate of growth were not helpful in differentiation. However, the association of pain, facial nerve paralysis, skin infiltration and enlarged ipsilateral cervical nodes with a final diagnosis of cancer was significant (P less than 0.005). Fixity of tumour and old age were also significant indicators of malignancy (P less than 0.05). When these symptoms and signs suggestive of malignant disease are associated with a parotid tumour, the patient should be prepared for the possibility of a radical operation. The surgeon should make extra efforts to obtain a histological diagnosis before proceeding to definitive surgery.

Adolescent↗
PubMed1988

Bypass surgery for unresectable oesophageal cancer: early and late results in 124 cases.

The early and late results of bypass surgery in 124 patients with unresectable oesophageal cancer are reported. Patients were grouped according to the extent of disease: group A, tumour localized to the oesophagus where severe pulmonary disease contra-indicated oesophagectomy (n = 9); group B, tumour less than or equal to 10 cm in length with mediastinal invasion (n = 81); group C, tumour greater than 10 cm in length with mediastinal invasion and/or fixed malignant lymph nodes (n = 33). Extent of disease was not recorded in one patient. The operative mortality was 4 per cent but 9 other patients died in hospital (hospital mortality, 11 per cent). Mortality was increased in patients undergoing colon bypass and in those with a large tumour load but these differences failed to reach statistical significance. The most frequent complication was neck sepsis, secondary to leakage from the proximal end of the excluded oesophagus. Eighty-nine per cent of the survivors could eat a normal, unrestricted diet on discharge and eighty-two per cent of survivors had complete and lasting relief from dysphagia. Median survival after bypass was 5 months but survival was significantly improved by radiotherapy to the tumour (P less than 0.001). Gastric bypass with radiotherapy is indicated in patients with extra-oesophageal spread of malignancy and in patients with tumours localized to the oesophagus who are unfit for resection. Bypass surgery may be contra-indicated in patients with a primary tumour greater than 10 cm in length and/or fixed lymph node metastases because mortality is increased and survival after operation is short.

Adult↗
PubMed1988

Renal calculi-urate as a urokinase inhibitor.

The formation of renal calculi is one of the most widely studied urinary ailments. Spectrophotometric analysis of urinary inhibition on the urokinase/plasmin system revealed a significant difference between subjects with and without renal calculi (P less than 0.001). The percentage urokinase/plasmin inhibition in the two groups was 77.1% for those with, and 47.1% for those without renal calculi. Because of the significant (P less than 0.015) positive correlation (r = 0.762) between the percentage inhibition of urokinase/plasmin and urinary urate concentration, the inhibition of urate on urokinase/plasmin and on plasmin and urokinase was investigated. The urokinase/plasmin system was inhibited up to 94.4% with 0.5 mM urate. Inhibition occurred with both low and high molecular weight urokinases. In order to determine which enzyme of the complex was inhibited, each was investigated independently and a 50% inhibition of urokinase activity was obtained with 4 mM urate. It was found that the urine of stone formers contained a higher concentration of urate than the urine of healthy subjects and that at the same time there was a decrease in urinary urokinase activity in these patients.

Adult↗
PubMed1988

Hormonal responses to analgesic nitrous oxide in man.

Analgesic concentrations of nitrous oxide were administered to 6 healthy male subjects, and blood samples were assayed for prolactin, ACTH, follicle stimulating hormone, luteinising hormone, growth hormone, cortisol and thyroid hormones. Analgesic nitrous oxide (mean concentration = 48.8%) produced statistically significant elevation of prolactin and depression of cortisol whilst not producing statistically significant changes in the other hormones assayed. The increase in prolactin and decrease in cortisol levels are similar to the hormonal changes associated with administration of opioids in man. We have also confirmed the findings of other workers that cortisol levels may not always be correlated with ACTH levels.

Adrenocorticotropic Hormone↗
PubMed1988

Selective exposure of active and sociable children to schistosomiasis.

Investigations into the impact of schistosomiasis on the physical and psychological development of children have yielded contradictory findings. This may be due to a failure to take account of transmission factors. In areas where Schistosoma haematobium is endemic, children who bathe regularly in contaminated water are more likely to contract the disease. The harmful effects of the disease may be masked in these more active and gregarious children, particularly when infections are mild and other parasitic infections and nutrional deficiencies are common. The social interaction of schoolchildren in an endemic area was monitored over a period of four months, and the principal finding was that infected children were more sociable than uninfected children in terms of their membership of the main playground groups. This paper discusses the evidence for selective exposure and the implications of the hypothesis for future research.

Child↗
PubMed1988

Vitamin B6 nutritional status in asthma: the effect of theophylline therapy on plasma pyridoxal-5'-phosphate and pyridoxal levels.

Plasma pyridoxal-5'-phosphate concentrations were significantly lower (p less than 0.001) in a group of 28 asthmatic women when compared to 33 controls. Plasma pyridoxal levels in the two groups were not different. Theophylline was administered to a group of 17 volunteers and resulted in large reductions in plasma pyridoxal-5'-phosphate levels, while plasma pyridoxal levels and urinary 4-pyridoxic acid excretion were unaffected by theophylline therapy. An in vitro study showed that theophylline did not interfere with the high performance liquid chromatography assay for pyridoxal-5'-phosphate, indicating that theophylline could affect liver metabolism of vitamin B6.

Adolescent↗
PubMed1987

Urinalysis reagent strips in the screening of children for urinary schistosomiasis in the RSA.

The use of urinalysis reagent strips (Labstix; Ames) in screening for Schistosoma haematobium infection in various schistosomiasis-endemic areas of the RSA was assessed in 941 children. Sensitivity, specificity, false-positive and false-negative rates and the positive predictive value for haematuria and proteinuria were calculated. Both haematuria and proteinuria were positively correlated with the presence of S. haematobium eggs in the urine. Intensity of infection correlated positively with the degree of haematuria and proteinuria (P less than 0.001). The presence and intensity of S. haematobium infection were more closely related to the presence and degree of haematuria than to proteinuria. Screening for haematuria alone enabled 83.1% of S. haematobium-positive and 89.7% of negative subjects to be detected accurately. The false-positive rate was 2.7%. It was found that a single parameter, haematuria, could be used to identify infected children in endemic areas. It was also found to be possible to use the reagent strips to select out S. haematobium-infected children with egg counts greater than 200 ova/10 ml urine. The simple model developed allows rapid identification of moderately to heavily infected children and can be used by paramedical staff in field situations.

Adolescent↗
PubMed1987

Rubella--a case for immunising male adolescents.

An outbreak of rubella at a training institution for predominantly adolescent males is described. The cost and inconvenience of the outbreak furnish evidence that immunisation in its own right is worth while, and should not be seen only as a means of protecting susceptible females of child-bearing age.

Adolescent↗
PubMed1987

Evaluation of the incisive papilla as a guide to anterior tooth position.

The incisive papilla provides a reference point on the edentulous cast that may be helpful in determining the anteroposterior position of the artificial incisors. The results of the study suggest that the labial surface of the maxillary incisors should be 12 to 13 mm from the posterior border of the incisive papilla. This measurement was significantly smaller in the sample of dentures examined, which suggests a tendency for the anterior teeth to be placed too far posteriorly in artificial dentures.

Adult↗
PubMed1987

Cryptosporidium-associated diarrhoea in children.

Over a 3-month period during summer, 30 out of a group of 194 children admitted with a primary diagnosis of gastro-enteritis with dehydration were found to excrete cryptosporidium oocysts in their stools. On retrospective analysis, children with cryptosporidia in their stools had a significantly higher mortality than those without. They spent a longer time in hospital and were more likely to have intestinal salmonella infection. They also had a higher incidence of bronchopneumonia. They were not significantly different from the group of children without cryptosporidia in respect of age, mass for age, duration of symptoms prior to hospitalization, prior treatment, or severity of metabolic derangement on admission. Since cryptosporidiosis has a recognized association with immune deficiency, the presence of cryptosporidium oocysts in the stools of our children with diarrhoea may be a pointer to morbidity and mortality.

Cryptosporidiosis↗
PubMed1987

Effect of different levels of oral pyridoxine supplementation on plasma pyridoxal-5'-phosphate and pyridoxal levels and urinary vitamin B-6 excretion.

Plasma pyridoxal-5'-phosphate and pyridoxal levels increased significantly (p less than 0.05) when single, oral bolus doses of pyridoxine were increased from 10 to 25 and from 25 to 50 mg in nine female volunteers. However, when the dose was increased to 100 mg, plasma pyridoxal-5'-phosphate levels did not differ significantly from those recorded after the 50 mg dose. Within 3 h plasma pyridoxal levels rose with a factor of 3.85 compared with the 50 mg dose but high pyridoxal levels were eliminated from the circulation. Renal clearance of pyridoxal remained a constant, low percentage (less than 2.0%) of each pyridoxine supplement in spite of the observed very high circulating pyridoxal levels. Pyridoxine supplementation is discussed in relation to circulating pyridoxal-5'-phosphate and pyridoxal availability for cellular metabolism.

Administration, Oral↗
PubMed1987

Oestrogen and progesterone receptor concentrations in leiomyoma and normal myometrium.

The content of cytoplasmic 17 beta oestradiol and progesterone receptors in human uterine leiomyoma and normal myometrium in the Negroid population was determined. Eighteen women of reproductive age, at various stages of the menstrual cycle, were included in the study. The serum oestrogen and progesterone concentrations were also measured. This is the first report in the literature in which oestrogen and progesterone receptors in leiomyoma are significantly higher than in normal myometrium (P = 0.0002). The steroid dependence of the growth of leiomyomas may be related to the steroid receptor level. The presence of persistently high concentrations of oestrogen and progesterone receptors in leiomyoma should be helpful in the treatment of this benign tumour.

Adult↗
PubMed1986

Plasma volume in black women with eclampsia.

Plasma volume was estimated in 11 black women with eclampsia and compared with 9 normotensive primigravidas. With respect to age, weight and height the two groups were similar and although plasma volume was 4.1% less in the reference group, this difference was not statistically significant.

Eclampsia↗
PubMed1986

Depressed plasma pyridoxal-5'-phosphate levels in tobacco-smoking men.

Tobacco-smoking men (n = 106) showed considerably lower plasma pyridoxal-5'-phosphate levels (P less than 0.001) than non-smoking controls (n = 143). A previously reported inverse relationship between plasma pyridoxal-5'-phosphate levels and age is confirmed by using new and sensitive high-performance liquid chromatography methodology for pyridoxal-5'-phosphate determinations. Plasma pyridoxal levels were neither lower in tobacco-smoking men nor could any relationship between pyridoxal levels and age be demonstrated. Two major risk factors for coronary artery disease, tobacco-smoking and increasing age, are thus associated with lower plasma pyridoxal-5'-phosphate levels.

Adult↗
PubMed1986

Determination of urinary 4-pyridoxic acid levels as 4-pyridoxic acid lactone using high-performance liquid chromatography.

A high-performance liquid chromatography method for quantitation of urinary 4-pyridoxic acid excretion is presented. Urine samples were treated with HCl to form 4-pyridoxic acid lactone. Acid-treated urine samples were diluted and analyzed by cation-exchange chromatography involving post-column alkalinization and fluorescence detection. Absence of interfering fluorescent urinary compounds was demonstrated by analyzing urine samples without lactonization and rechromatography of aliquots of 4-pyridoxic acid lactone peaks employing reverse-phase chromatography. The method is suitable for determination of urinary 4-pyridoxic acid excretion in nutritional, metabolic, and pharmacokinetic studies.

Chromatography, High Pressure Liquid↗