PCA in burn injuries: the subcutaneous route.
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Analgesia, Patient-Controlled↗
Biomedical subjects
P J Becker
Publications and source records attributed to P J Becker.
Diseases, medication, and postinsertion visits in complete denture wearers.
The records of 268 patients were used to assess the effects of five disease/drug complexes on the number of postinsertion visits in complete denture wearers. The data were analyzed with SAS and BMDP computer packages. The results showed a statistically significant increase in the number of postinsertion visits in patients who had central nervous system or psychiatric disorders. Practitioners are alerted to consider the ergonomic implications at the outset of treatment.
Adult↗
Vitamin B-12, vitamin B-6, and folate nutritional status in men with hyperhomocysteinemia.
We measured the vitamin B-6, vitamin B-12, and folic acid nutritional status in a group of apparently healthy men (n = 44) with moderate hyperhomocysteinemia (plasma homocysteine concentration > 16.3 mumol/L). Compared with control subjects (n = 274) with normal plasma homocysteine (< or = 16.3 mumol/L) concentrations, significantly lower plasma concentrations of pyridoxal-5'-phosphate (P < 0.001), cobalamin (P < 0.001), and folic acid (P = 0.004) were demonstrated in hyperhomocysteinemic men. The prevalence of suboptimal vitamin B-6, B-12, and folate status in men with hyperhomocysteinemia was 25.0%, 56.8%, and 59.1%, respectively. In a placebo-controlled follow-up study, a daily vitamin supplement (10 mg pyridoxal, 1.0 mg folic acid, 0.4 mg cyanocobalamin) normalized elevated plasma homocysteine concentrations within 6 wk. Because hyperhomocysteinemia is implicated as a risk factor for premature occlusive vascular disease, appropriate vitamin therapy may be both efficient and cost-effective to control elevated plasma homocysteine concentrations.
Adult↗
The effect of ethnicity on appendicular bone mass in white, coloured and Indian schoolchildren.
Ethnic differences in the incidence and prevalence of osteoporosis have been shown throughout the world. In South Africa the prevalence of osteoporosis is much higher in whites than in blacks. This is surprising, since factors that might predispose to reduce bone mass are more preponderant in black communities. The present research was undertaken to determine whether differences in bone mass during the period of bone accretion could explain the difference in the incidence of osteoporosis. In this paper we report on differences in appendicular bone mass between white, coloured and Indian children and teenagers (6-18 years) from Johannesburg. The effects of weight, height, puberty and skinfold thickness on bone mass were also assessed. The bone width (BW) of white boys was greater than that of Indian boys, while the bone mineral content (BMC) and BMC/BW were greater in white boys than in both Indian and coloured boys. After adjustment for differences in weight and height, the BW of coloured boys was significantly greater than that of white boys, while all differences in BMC and BMC/BW became non-significant. For girls there were no significant differences in bone mass measurements, but after adjustment for height and weight coloured girls had significantly greater BMC and BMC/BW than either white or Indian girls. This greater weight- and height-adjusted bone mass in coloured girls is consistent with the impression of a lower incidence of osteoporosis in coloured women than in white women.
Adolescent↗
Fermentation of the carbohydrate of banana (Paradisiaca sapientum) in the human large intestine.
Fermentation of dietary fiber and resistant starch is one of the major physiological functions of the human large intestine. The major substrate for fermentation is probably starch. This study assessed the effect of bananas--a carbohydrate with a highly resistant starch content--on breath hydrogen and methane production in methane and nonmethane-producing subjects. The results showed that both groups produced significant quantities of hydrogen after a banana meal, compared with a sucrose control test meal, measured as area under the curve (28 +/- 5.6 vs. 8.1 +/- 1.4 10(3) pm/min, p = 0.008 in methane producers and 39 +/- 15.2 vs. 10.5 +/- 4.1 10(3) ppm/min, p = 0.01 in methane nonproducers). The rise in breath hydrogen started a half hour after the banana meal and peaked at 3 1/2 h in methane nonproducers, whereas in methane producers, the rise began after 2 h and peaked at 5 h. Methane production was not significantly stimulated by the test meals. This study shows that bananas stimulate fermentation mainly through the production of hydrogen, with minimal effect on methane production. The possible mechanisms for this process are discussed.
Adult↗
Theophylline increases pyridoxal kinase activity independently from vitamin B6 nutritional status.
Asthmatics treated with theophylline, a potent inhibitor of pyridoxal kinase and therefore a vitamin B6 antagonist, demonstrated a significant correlation (r = 0.71; p < 0.001) between drug plasma levels and erythrocyte pyridoxal kinase activities. A cross-over, placebo controlled study was completed on 15 healthy volunteers to investigate the mechanism by which theophylline induces pyridoxal kinase activity. The subjects were supplemented with vitamin B6 or placebo for two weeks before theophylline therapy was started. Vitamin B6 supplementation resulted in a four-fold increase in circulating pyridoxal 5'-phosphate levels, while placebo had no effect. When theophylline therapy was commenced, erythrocyte pyridoxal kinase activities increased significantly (p < 0.001) irrespective of whether vitamin B6 or placebo was supplemented. It is concluded that a depressed vitamin B6 status is not responsible for higher erythrocyte pyridoxal kinase activities encountered during theophylline therapy, but that the drug is directly responsible for elevated enzyme levels.
Adult↗
Partial denture prosthodontic procedures employed by practising graduates of the University of the Witwatersrand, Johannesburg.
This study sought answers to the following two questions related to the teaching of partial denture prosthodontics in the Department of Prosthetic Dentistry at the University of the Witwatersrand, Johannesburg (Wits). Firstly, do practising graduates from Wits assiduously apply, or do they perhaps ignore, the concepts, principles, and practices taught to them at undergraduate level? Secondly, is there any merit in providing additional tutorials on partial denture prosthodontics to undergraduate students at Wits? A questionnaire was mailed to dentists who had graduated at Wits between 1979 and 1986. This sample of 302 subjects was divided into two groups: Group I--those who had graduated between 1979 and 1982; Group II--those who had graduated between 1983 and 1986 and had received additional tutorials on partial denture design. The results suggest that a wide gap exists between faculty beliefs about partial denture design and fabrication and the methods used in general dental practice. Moreover, additional tutorials had some effect on the attitudes and practices of the respondents.
Dentists↗
The effect of blood sample aging and food consumption on plasma total homocysteine levels.
The stability of homocysteine in whole blood and plasma was investigated. Total homocysteine concentrations in whole blood increased rapidly to values in excess of 180% of the basal concentration if whole blood was left at ambient temperature. Sodium fluoride partially inhibited homocysteine accumulation, while refrigeration inhibited homocysteine accumulation for at least 4 h. Since intracellular concentrations of homocysteine were low, the results indicate continued metabolism of L-methionine to homocysteine after the blood sample had been obtained. In contrast to whole blood, homocysteine was stable in plasma, even at room temperature. Food consumption (normal breakfast) resulted in significantly lower plasma homocysteine concentrations, which returned to pre-prandial concentrations 8 h later. The results indicate that both blood sampling and food intake should be rigorously standardized in epidemiological studies to elucidate the possible role of elevated circulating homocysteine concentrations in premature vascular disease.
Adult↗
The effect of ethnic group on appendicular bone mass in children.
The prevalence of senile and postmenopausal osteoporotic fractures is considerably higher in white than black women. Although the reasons for the genetic difference have not been elucidated, it has been suggested that ethnic differences in peak bone mass may be partially responsible. The present study examined appendicular bone mass (single-photon absorptiometry, SPA) in black and white children between the ages of 6 and 20 years. The sample was stratified for ethnic group, age, and sex. The effect of weight, height, puberty, and skinfold thickness on bone mass was also assessed. The bone width (BW) and bone mineral content (BMC) of males were significantly higher than those of females (p less than 0.0001). There were no statistically significant differences in bone mineral content normalized for bone width (BMC/BW) between the sexes (p = 0.1743 for whites and p = 0.5456 for blacks). The bone mass parameters of black girls were generally lower than those of white girls. After adjusting for height, BMC and BMC/BW of black girls tended to be greater than those of white girls (unadjusted p = 0.0258 for BMC and p = 0.0340 for BMC/BW). White boys tended to have greater bone mass parameters than black boys. After adjusting for height the trends disappeared. Thus, unlike the studies of bone mass in adults from the United States, we were unable to show that age-matched black children have higher bone mass than whites. After adjusting for height, however, the bone mass of black children (especially black girls) was marginally, but not significantly, greater than that of white girls.
Adolescent↗
The value of radiographic predictors of the rate of mandibular residual ridge resorption.
This study tested the relationships between the rate of mandibular residual ridge resorption and the following two variables: cortical thickness at the gonion, and the proportion of cortical bone at the symphysis. These parameters were also compared between men and women. Measurements of cortical thickness at the gonion on panoramic radiographs were compared with similar measurements on lateral cephalometric radiographs. The results showed that neither cortical thickness at the gonion nor the proportion of cortical bone at the symphysis could be used as radiographic predictors of the rate of mandibular bone resorption. The rate of resorption was significantly greater in men than in women, while cortical thickness at the gonion in women was significantly less than that in men. Furthermore, the authors concluded that cephalometric and panoramic measurements should not be used interchangeably.
Adult↗
Serum keratan sulfate levels in marathon runners.
The effect of strenuous joint loading on the metabolism of articular cartilage in man is not known. The development of a non-invasive immunoassay for the assessment of the catabolism of cartilage aggrecan has enabled us to quantify keratan sulfate (KS), a component of aggrecan, in the serum of fifteen male marathon runners. Serum KS was measured by an ELISA before and immediately after a marathon (42 km), as well as 48 hours after the completion of the race. The mean level at rest was similar to those previously reported for another population of age-matched males. There was no statistically significant difference in the serum level of KS at the three different readings. Further, there was no correlation between age, height, weight and performance time, and the serum level of KS at any of the three different times. We conclude that marathon running by carefully trained runners causes neither a transient nor a sustained increase in proteoglycan catabolism in articular cartilage.
Adult↗
The comparison of the effects of multi and single doses of buspirone, chlordiazepoxide and hydroxyzine on psychomotor function and EEG.
This study compares the effects of buspirone (5 mg), chlordiazepoxide (5 mg), hydroxyzine (10 mg) and placebo on psychomotor function and EEG, when taken thrice daily for a period of two weeks, with those after a single dose administration. Nine healthy volunteers participated in the study. The battery of psychomotor tests included peak velocity of saccadic eye movements (SEM), a Sternberg memory scanning and choice reaction time test (SMS-CRT) and critical flicker fusion frequency (CFFF). The peak velocity of saccadic eye movements was significantly impaired by the single dose of hydroxyzine (P = 0.03) in comparison to the multidose results. A similar comparison regarding buspirone only approached significance (P = 0.07). The SMS-CRT and CFFF did not reveal any difference between the multi and single dose regimens. Spectral analysis of the EEG did not distinguish between the multi and single dosage schedules regarding the respective drugs in the low doses administered.
Adult↗
Dust exposure and pneumoconiosis in a South African pottery. 2. Pneumoconiosis and factors influencing reading of radiological opacities.
A cross sectional radiological survey of workers exposed to pottery dust during the manufacture of wall tiles and bathroom fittings was conducted in a South African factory. Roughly one third of workers with 15 or more years of service in high dust sections of the factory had pneumoconiosis. Previously undiagnosed advanced cases, including two with progressive massive fibrosis, were working in dusty occupations. A firm diagnosis of potters' pneumoconiosis was made in 11 of the 358 workers radiographed; all had served more than 10 years suggesting that radiography of workers with more than 10 years service would be a successful case finding strategy in South Africa. A combination of rounded and irregular opacities was the most common radiological finding in the workers with pneumoconiosis (55%). Three readers reported on the chest radiographs, and all found an association between small radiological opacities, which were usually irregular or a combination of irregular and rounded, and exposure to pottery dust. The occurrence of irregular radiological opacities in workers exposed to pottery dust deserves further study. The least experienced reader significantly associated age with small opacities when duration of service (years) was used to measure exposure to dust. Sex was not an important predictor of radiological changes consistent with pneumoconiosis. Breast shadows were not an important cause of false positive readings and participating women did not develop pneumoconiosis after less exposure than men.
Humans↗
A novel study on the effect of acetylsalicylic acid on the binding capacity of estrogen receptors from MCF-7 cells.
The effect of acetylsalicylic acid (ASA, aspirin) was investigated on [3H]-estradiol-17 beta ([3H]-E2) binding to estrogen receptors (ER) from MCF-7 mammary tumour cells. No effect was observed using the monoclonal estrogen receptor-enzyme immunoassay (ER-EIA). In contrast to the ER-EIA, the radioreceptor assay (RRA) showed decreases of [3H]-E2 specific binding in the presence of increasing amounts of ASA. It is therefore concluded that these results demonstrate that ASA possibly affects the direct binding of E2 to region E of the ER of human breast cancer MCF-7 cells, but does not affect binding of monoclonal antibodies to regions D and F of the ER.
Antibodies, Monoclonal↗
The effect of impression technique and multiple pours on accuracy of stone models.
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Dental Impression Technique↗
Using changes in attributable risk to predict long-term efficacy of simvastatin treatment.
It is a common perception that coronary heart disease (CHD) deaths will decline by 2% for every 1% decrease in serum total cholesterol (TC). We investigated the changes in serum TC concentrations obtained with simvastatin, an inhibitor of hydroxymethylglutaryl-CoA reductase, in 70 hypercholesterolemic subjects. Although simvastatin reduced serum TC concentrations by 30% after 6 months, calculations from age- and risk-related TC quintiles show that the absolute difference in attributable CHD deaths would be just > 1%. These results are reminiscent of the experience from several large prospective primary drug trials that demonstrated impressive relative benefit ratios but much smaller absolute differences (< 2%) in CHD endpoints between the treated and untreated groups. This epidemiologically based approach of assessing efficacy and potential long-term benefit of a lipid-lowering drug may be more appropriate and potentially less misleading than just the percentage change of TC (or other lipoproteins) so frequently reported in short-term drug trials.
Adult↗
The effect of hypovolaemia on healing of the right and the left colon. An experimental study.
An experimental study was carried out to investigate the effect of a period of hypovolaemia prior to surgery on healing of the right and left colon of the baboon. Colonic healing was assessed in three ways: in terms of (i) anastomotic leakage, (ii) hydroxyproline concentrations and (iii) breaking strength. The results suggest that hypovolaemia before surgery affects the right and left colon similarly.
Anastomosis, Surgical↗
Transfer of DDT used in malaria control to infants via breast milk.
The transfer of p,p'-DDT (1,1,1-tricholoro-2,2-bis(4-chlorophenyl)ethane) and its metabolites to infants via breast-feeding was studied in an area of KwaZulu, South Africa, where DDT is used to interrupt malaria transmission. Samples of whole blood were collected from 23 infants, together with samples of breast milk from their respective mothers. The mean sigma DDT (total DDT) in the whole blood was 127.03 micrograms.l-1 and that in the breast milk, 15.06 mg.kg-1 (milk fat). The % DDT (% DDT of sigma DDT) was significantly higher in the infant blood than in the breast milk (P less than 0.05). A multiplicative regression analysis indicated that sigma DDT increased significantly (P less than 0.01) in infant whole blood with infant age. Multiple regression showed that 70.0% of the variation in sigma DDT was due to the variation in parity of the mother, age of the infant, and the sigma DDT in breast milk. These variables accounted also for 76.3% of the variation in p,p'-DDE but only for 38.2% of that in p,p'-DDT. Organochlorines were therefore largely transferred to the infant from the mother, with DDT in the environment playing a secondary role.
Age Factors↗