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Biomedical subjects

H S Schoeman

Publications and source records attributed to H S Schoeman.

At least 37 records · Page 2Linked to original sources
PubMed1987

A comparative study of pipemidic acid and nitrofurantoin in the treatment of uncomplicated urinary tract infections.

In an open uncontrolled trial 60 women with confirmed uncomplicated urinary tract infections were randomly allocated to receive either pipemidic acid (Septidron; Ethimed) or nitrofurantoin for 10 days. Urine cultures were done on day 1 and day 10. No statistical difference was found in the subjective and objective assessments of the response to the two medications and it is concluded that pipemidic acid is a satisfactory and effective alternative to nitrofurantoin in the treatment of uncomplicated urinary tract infections in women.

Adult↗
PubMed1987

Drug interactions with urate excretion in man.

The effects of pyrazinamide and ampicillin on the uricosuric response to probenecid and benzbromarone were studied in six normal subjects. The amount of uric acid was calculated for the 24 h volume of urine and the urate and creatinine clearances were determined for each of three urinary collection periods in order to calculate the percentage Curate/Ccreatinine. Ampicillin alone caused a significant uricosuria in the 0-2 h (p less than 0.025) and 8-24 h (p less than 0.025) periods. Benzbromarone caused a significant reduction in all the parameters. These observations suggest that high concentrations ampicillin compete with uric acid for reabsorption, but that its delayed uricosuric action can be ascribed to the binding of this dipeptide to a charge-mediated receptor site on the brush border membrane of proximal tubular cells. It would also appear that benzbromarone is secreted by the pyrazinamide-sensitive mechanism for urate secretion as it can cause a paradoxical retention of urate, but leaves the other probenecid-sensitive secretory transport process unoccupied as indicated by the fact that it does not change the kinetics of ampicillin.

Adult↗
PubMed1987

Fat embolism and the fat embolism syndrome. A double-blind therapeutic study.

Fifty-five adults who had sustained a tibial fracture, or a femoral fracture, or both, were subjected to a double-blind randomised study to determine the efficacy of methylprednisolone in treating the fat embolism syndrome. This drug maintained arterial oxygen levels, stabilised or reduced the serum level of free fatty acids, and decreased the risk of the fat embolism syndrome in a statistically significant proportion of patients. Gurd's criteria for the diagnosis of the fat embolism syndrome were found inadequate. Other more sensitive criteria for early diagnosis and effective management were determined. There were no deaths or serious morbidity in our series.

Adolescent↗
PubMed1985

Adult respiratory distress syndrome in cases of severe trauma--the prophylactic value of methylprednisolone sodium succinate.

The more important known pathogenetic mechanisms apparently responsible for the development of adult respiratory distress syndrome (ARDS) are briefly discussed. Reactions in the development of ARDS for which corticosteroids are possibly beneficial are pointed out. A prospective study involving 92 patients was designed to determine the prophylactic value of methylprednisolone sodium succinate (MPSS) (Solu-Medrol; Upjohn) in preventing ARDS. MPSS was administered to 47 seriously injured patients and omitted from the management regimen of 45 patients comparable as regards age and severity of injury. The percentage of patients who developed ARDS was significantly lower in the group that received MPSS than in the control group.

Adult↗
PubMed1985

Antipyrine metabolism in African villagers.

Antipyrine clearance has been measured from serial serum samples in 49 healthy black Africans from a village in Southern Africa. The subjects follow a lifestyle which minimally exposes them to environmental inducing or inhibiting agents. Food is mainly maize cereal with a protein content of only about 8.8%, together with greens. Antipyrine clearance, half-life and apparent volume of distribution (mean +/- SD) were, respectively, 0.538 +/- 0.163 ml min-1, kg-1, 14.81 +/- 6.5 h and 0.626 +/- 0.075 litre/kg. These results do not differ significantly from the mean values found in a group of lactovegetarian Indo-Pakistani immigrants to Britain. This would suggest that the major environmental determinant influencing hepatic mixed-function oxidase activity is the presence or absence of meat in the diet. However, the relative contributions of environment and heredity will be difficult to determine.

Adult↗
PubMed1985

Paracetamol metabolism in African villagers.

Paracetamol clearance has been measured from serial serum samples in 49 healthy black Africans from a village in Southern Africa. The subjects are minimally exposed to known environmental inducing or inhibiting agents and the staple diet consists of maize cereal and greens. The mean clearance (+/- SD) was 4.98 +/- 1.61 ml min-1 kg-1, which is significantly faster than the values found in previous investigations with paracetamol in whites and Asian immigrants in London. The mean half-lives were fairly similar but the apparent volumes of distribution were also found to be larger in the present study. The ethnic difference in paracetamol kinetics identified in this study is possibly genetically controlled.

Acetaminophen↗
PubMed1984

The effects of two combinations of a beta-blocker and a diuretic on diuresis in normal subjects.

Combinations of a beta-blocker and a diuretic often produce a greater fall in blood pressure than does either drug alone. Furthermore, beta-blockers prevent an increase in plasma renin activity, thereby attenuating diuretic-induced potassium excretion and also the reduction in hypotensive response to the diuretic. This study was designed to compare the effects of the two fixed-dose combinations atenolol 100 mg plus chlorthalidone 25 mg (Tenoretic; ICI) and sotalol 320 mg plus hydrochlorothiazide 50 mg (Sotazide; B-M) on the pattern of diuresis and the biochemical composition of the urine in normal subjects. These preparations differ mainly in that the plasma half-lives of chlorthalidone and hydrochlorothiazide are 60 hours and 6 hours respectively; the former therefore accumulates when given once daily while the latter does not. These two preparations were found to have similar effects on the pattern of diuresis and the biochemical values. It is therefore concluded that the relationship between the serum chlorthalidone level and the fall in serum potassium level is in keeping with the flat dose-response curves for the thiazide and phthalimide diuretics.

Adult↗
PubMed1984

Influence of food and reduced gastric acidity on the bioavailability of bacampicillin and cefuroxime axetil.

The present study was designed to investigate the effect of food and of a raised intragastric pH on the bioavailability of two prodrug beta-lactam, antibiotics, namely bacampicillin and cefuroxime axetil. Six healthy volunteers participated in an intraindividual comparison of absorption of (a) prodrug, (b) breakfast, followed by prodrug, (c) breakfast, ranitidine and sodium bicarbonate followed by prodrug, and (d) ranitidine and sodium bicarbonate, followed by prodrug. All volunteers were dosed with both bacampicillin and cefuroxime axetil under the above regimens. The drug-free periods between trials were 7 days. Blood samples were obtained before and 20, 40, 60, 90, 120, 150, 180, 210 min and 4, 5, 6, 8 and 10 h after administration. The urine was collected for a period of 10 h after dosing with the antibiotic. An estimation of the relative bioavailability of the drugs under the various regimens was made by comparing the average areas under the serum concentration time curves and also the amounts recovered in the urine. Both food and reduced gastric acidity decreased the bioavailability of bacampicillin (as ampicillin) and these variables had an additive lowering effect on the AUC and percentage urinary recovery. Possibly this ester becomes partially hydrolyzed prior to absorption on raising the intragastric pH. Adsorption onto food components or complexing with proteins may also play a role in the reduced bioavailability of bacampicillin in the presence of food. In contrast, the absorption of the cefuroxime ester was enhanced postprandially. This may be rationalized in terms of delayed gastric emptying and gastrointestinal transit which allows more complete dissolution or prolonged residence at the most favourable site of absorption in the intestine.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1983

Beta-adrenergic blocking drugs and renal function.

A baboon model was used to investigate the effects of atenolol, nadolol, sotalol and labetalol on renal function. The glomerular filtration rate (GFR) and renal blood flow (RBF) were measured, using radionuclides and a gamma camera, before and after 1 week's oral administration of these drugs. All the drugs caused an increase in the GFR, but this reached statistical significance only in the cases of sotalol (P less than 0,025) and labetalol (0,05 less than P less than 0,10). The RBF was not significantly changed, although it decreased in all cases.

Adrenergic beta-Antagonists↗
PubMed1983

Adjuvant chemotherapy for operable breast cancer in postmenopausal women.

Survival figures of women with operable breast cancer reached a plateau 40 years ago. It was only with the advent of adjuvant chemotherapy that these figures showed a dramatic improvement. Data obtained in 105 postmenopausal women with operable breast cancer, treated at our clinic, are presented. Patients with axillary node disease were treated on four different protocols: cyclophosphamide + methotrexate + fluoro-uracil (CMF) with or without immunotherapy was compared with CMF + vincristine + prednisone, while other studies compared observation only with CMF + prednisone and CMF + prednisone + tamoxifen. Patients older than 65 years received tamoxifen or placebo. Patient discriminants and treatment regimens are discussed. Results indicating that certain subsets of postmenopausal women definitely need adjuvant chemotherapy are presented. The literature is briefly reviewed and the motivation for our new studies explained.

Aged↗
PubMed1983

Should young adults with sore throat be treated with antibiotics?

The diagnosis of streptococcal sore throat on clinical grounds remains a problem. In this study the clinical prediction in a group of young adults corresponded with laboratory findings indicative of a streptococcal (group A or non-A) infection in 23% of cases. The culture of throat swabs was of little value, as the only group A culture-positive patient did not show an antibody response, indicating a carrier state. In 5 cases a streptococcal infection was diagnosed on rising antibody titres only, as culture remained negative. The value of rising antibody titres as a diagnostic tool is also questioned, since they occurred more frequently in the healthy controls than in the sore-throat group. Antibiotic treatment for sore throat was rarely supported by laboratory findings in the young adult population studied.

Adult↗
PubMed1983

Indoramin as an antihypertensive agent in the treatment of essential hypertension. A multicentre trial.

The efficacy of indoramin (Baratol; Wyeth) in combination with a thiazide diuretic was assessed in an open non-comparative trial. The dosage of indoramin was increased at 2-weekly intervals until control was obtained or until a maximum daily dosage of 150 mg was reached. Treatment was successful in 78% of patients and a significant reduction in diastolic blood pressure (DBP) was obtained in another 7%. In combination with a thiazide diuretic, indoramin, when individually titrated for each patient, reduced the DBP by an average of 20 mmHg. When taken with a thiazide diuretic, indoramin 75 mg/d or less controlled the DBP in 76% of all the patients. The effect of indoramin on the pulse rate was minimal. For all practical purposes, orthostatic hypotension did not occur. A number of patients presented with side-effects but these proved to be transient in a large percentage of cases.

Benzothiadiazines↗
PubMed1983

Ultrasonic prediction of fetal mass.

A clinically accurate method for estimating fetal mass from fetal body parameters is reviewed. The abdominal circumference is first calculated from the anteroposterior and transverse diameters. This is used as an extra indicator of fetal age. By adding the biparietal diameter, these measurements are converted into fetal mass. From percentile tables the fetal mass at different stages of pregnancy and at term can then be predicted. This method was used on 101 private patients and the average error between actual and predicted mass was 210 g (6.5% of the birth mass).

Birth Weight↗
PubMed1983

Combination of dacarbazine, mitomycin C, 5-fluorouracil and vincristine in advanced colorectal cancer.

Thirty patients with advanced measurable colorectal cancer received monthly courses of a combination of dacarbazine, mitomycin C, 5-fluorouracil, and vincristine (FIVMit-Or). Four of the patients had received prior chemotherapy. Two patients were not evaluable for response. Objective response was obtained in four patients. Severe toxicity was encountered in 11 patients. It is concluded that unlike the four-drug combination of 5-fluorouracil, DTIC, vincristine and BCNU (FIVB), the present regimen did not have significant antitumour activity in advanced colorectal cancer.

Adult↗
PubMed1982

Carcinoembryonic antigen as a marker in patients with breast cancer receiving postsurgical adjuvant chemotherapy.

Serial plasma CEA levels were determined over a period of 1-3 years in 114 patients receiving adjuvant chemotherapy for T1, 2 or 3a N+ MO breast cancer. CEA values were correlated with clinical status, scintiscans, and other biochemical parameters. CEA values greater than 2.5 ng/ml were considered abnormal. Forty-one patients had normal values throughout the adjuvant period. In 73 patients where abnormal values occurred, four different patterns were seen: (1) a statistically significant number (30/73) had initial elevations with a decreasing titer; (2) rising titer (10/73); (3) fluctuating titer of transient elevation (25/73); and (4) persistent elevation (8/73). Seventeen patients developed overt metastases, this was associated with a rising CEA in nine patients (P less than 0.002). CEA was more sensitive for predicting relapse than alkaline phosphatase or LDH. The correlation between CEA determination and the eventual development of metastatic disease is striking, and has implications for the design of future clinical trials. Results indicate that CEA could be used to identify high risk patients, to estimate efficacy of chemotherapeutic regime, and to determine optimal duration of therapy.

Antineoplastic Agents↗
PubMed1982

Adjuvant chemotherapy for operable breast cancer in premenopausal women.

Surgery alone does not cure breast cancer, and adjuvant chemotherapy has changed the management of this disease. Data obtained in 81 premenopausal women with operable breast cancer, treated at our clinic, are presented. Patients with axillary node disease were treated on three different protocols: cyclophosphamide + methotrexate + fluoro-uracil + vincristine + prednisone (CMFVP), cyclophosphamide + methotrexate + fluoro-uracil (CMF), and CMF + immunotherapy with methanol extract residue of BCG (CMF + MER). Patient discriminants and treatment regimens are discussed. Analysis of the results obtained in 49 patients in one study showed an extension of disease-free survival to 4,25 years, that CMFVP was superior to CMF with or without MER, and that immunotherapy was not beneficial. The literature is briefly reviewed and the motivation for our newer studies stated.

Adult↗
PubMed1981

The effects of labetalol and oxprenolol on blood lipids.

Since a high risk of coronary heart disease is associated with high serum total cholesterol levels and low high-density lipoprotein (HDL) cholesterol levels, the effects of labetalol (Trandate; Allen & Hanburys) and oxprenolol (Trasicor; Ciba-Geigy) on blood lipids were studied. Eight normal volunteers, mean age 25,8 years, were involved in a randomized cross-over trial; all received each of the drugs for a 3-week period, separated by a wash-out period of 1 week. Both labetalol and oxprenolol reduced total serum cholesterol levels; these changes are statistically highly significant; Since the drugs had no significant effect on HDL cholesterol levels, the ratio of total cholesterol to HDL cholesterol was significantly decreased. Changes in triglyceride levels after both labetalol and oxprenolol administration were slight and did not reach statistical significance. The alpha-blockade caused by labetalol does no materially affect changes in blood lipid values brought about by beta-blockade. This study does not support previous reports, which have directed attention towards the possibility that, owing to alterations in lipid transport, adrenergic blocking agents might accelerate atherogenesis.

Adult↗