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Objectives: To determine whether recruitment of rural students and uptake of extended rural placements are associated with students' expressed intentions to undertake rural internships and students' acceptance of rural internships after finishing medical school, and to compare any associations., Design, Setting and Participants: Longitudinal study of three successive cohorts (commencing 2005, 2006, 2007) of medical students in the Sydney Medical Program (SMP), University of Sydney, New South Wales, using responses to self-administered questionnaires upon entry to and exit from the Sydney Medical School and data recorded in rolls., Main Outcome Measures: Students' expressed intentions to undertake rural internships, and their acceptance of rural internships after finishing medical school., Results: Data from 448 students were included. The proportion of students preferring a rural career dropped from 20.7% (79/382) to 12.5% (54/433) between entry into and exit from the SMP. A total of 98 students took extended rural placements. Ultimately, 8.1% (35/434) accepted a rural internship, although 14.5% (60/415) had indicated a first preference for a rural post. Students who had undertaken an extended rural placement were more than three times as likely as those with rural backgrounds to express a first preference for a rural internship (23.9% v 7.7%; χ(2) = 7.04; P = 0.008) and more than twice as likely to accept a rural internship (21.3% v 9.9%; χ(2) = 3.85; P = 0.05)., Conclusion: For the three cohorts studied, rural clinical training through extended placements in rural clinical schools had a stronger association than rural background with a preference for, and acceptance of, rural internship.

Background: Since the mid-1990s, early dialysis initiation has dramatically increased in many countries. The Initiating Dialysis Early and Late (IDEAL) study demonstrated that, compared with late initiation, planned early initiation of dialysis was associated with comparable clinical outcomes and increased health care costs. Because residual renal function is a key determinant of outcome and is better preserved with peritoneal dialysis (PD), the present pre-specified subgroup analysis of the IDEAL trial examined the effects of early-compared with late-start dialysis on clinical outcomes in patients whose planned therapy at the time of randomization was PD., Methods: Adults with an estimated glomerular filtration rate (eGFR) of 10 - 15 mL/min/1.73 m(2) who planned to be treated with PD were randomly allocated to commence dialysis at an eGFR of 10 - 14 mL/min/1.73 m(2) (early start) or 5 - 7 mL/min/1.73 m(2) (late start). The primary outcome was all-cause mortality., Results: Of the 828 IDEAL trial participants, 466 (56%) planned to commence PD and were randomized to early start (n = 233) or late start (n = 233). The median times from randomization to dialysis initiation were, respectively, 2.03 months [interquartile range (IQR):1.67 - 2.30 months] and 7.83 months (IQR: 5.83 - 8.83 months). Death occurred in 102 early-start patients and 96 late-start patients [hazard ratio: 1.04; 95% confidence interval (CI): 0.79 - 1.37]. No differences in composite cardiovascular events, composite infectious deaths, or dialysis-associated complications were observed between the groups. Peritonitis rates were 0.73 episodes (95% CI: 0.65 - 0.82 episodes) per patient-year in the early-start group and 0.69 episodes (95% CI: 0.61 - 0.78 episodes) per patient-year in the late-start group (incidence rate ratio: 1.19; 95% CI: 0.86 - 1.65; p = 0.29). The proportion of patients planning to commence PD who actually initiated dialysis with PD was higher in the early-start group (80% vs 70%, p = 0.01)., Conclusion: Early initiation of dialysis in patients with stage 5 chronic kidney disease who planned to be treated with PD was associated with clinical outcomes comparable to those seen with late dialysis initiation. Compared with early-start patients, late-start patients who had chosen PD as their planned dialysis modality were less likely to commence on PD.

Background: Planned early initiation of dialysis therapy based on estimated kidney function does not influence mortality and major comorbid conditions, but amelioration of symptoms may improve quality of life and decrease costs., Study Design: Patients with progressive chronic kidney disease and a Cockcroft-Gault estimated glomerular filtration rate of 10-15 mL/min/1.73 m(2) were randomly assigned to start dialysis therapy at a glomerular filtration rate of either 10-14 (early start) or 5-7 mL/min/1.73 m(2) (late start)., Setting & Population: Of the original 828 patients in the IDEAL (Initiation of Dialysis Early or Late) Trial in renal units in Australia and New Zealand, 642 agreed to participate in this cost-effectiveness study. STUDY PERSPECTIVE & TIMEFRAME: A societal perspective was taken for costs. Patients were enrolled between July 1, 2000, and November 14, 2008, and followed up until November 14, 2009., Intervention: Planned earlier start of maintenance dialysis therapy., Outcomes: Difference in quality of life and costs., Results: Median follow-up of patients (307 early start, 335 late start) was 4.15 years, with a 6-month difference in median duration of dialysis therapy. Mean direct dialysis costs were significantly higher in the early-start group ($10,777; 95% CI, $313 to $22,801). Total costs, including costs for resources used to manage adverse events, were higher in the early-start group ($18,715; 95% CI, -$3,162 to $43,021), although not statistically different. Adjusted for differences in baseline quality of life, the difference in quality-adjusted survival between groups over the time horizon of the trial was not statistically different (0.02 full health equivalent years; 95% CI, -0.09 to 0.14)., Limitations: Missing quality-of-life questionnaires and skewed cost data, although similar in each group, decrease the precision of results., Conclusion: Planned early initiation of dialysis therapy in patients with progressive chronic kidney disease has higher dialysis costs and is not associated with improved quality of life., (Copyright © 2011 National Kidney Foundation, Inc. Published by Elsevier Inc. All rights reserved.)

Background: In clinical practice, there is considerable variation in the timing of the initiation of maintenance dialysis for patients with stage V chronic kidney disease, with a worldwide trend toward early initiation. In this study, conducted at 32 centers in Australia and New Zealand, we examined whether the timing of the initiation of maintenance dialysis influenced survival among patients with chronic kidney disease., Methods: We randomly assigned patients 18 years of age or older with progressive chronic kidney disease and an estimated glomerular filtration rate (GFR) between 10.0 and 15.0 ml per minute per 1.73 m2 of body-surface area (calculated with the use of the Cockcroft-Gault equation) to planned initiation of dialysis when the estimated GFR was 10.0 to 14.0 ml per minute (early start) or when the estimated GFR was 5.0 to 7.0 ml per minute (late start). The primary outcome was death from any cause., Results: Between July 2000 and November 2008, a total of 828 adults (mean age, 60.4 years; 542 men and 286 women; 355 with diabetes) underwent randomization, with a median time to the initiation of dialysis of 1.80 months (95% confidence interval [CI], 1.60 to 2.23) in the early-start group and 7.40 months (95% CI, 6.23 to 8.27) in the late-start group. A total of 75.9% of the patients in the late-start group initiated dialysis when the estimated GFR was above the target of 7.0 ml per minute, owing to the development of symptoms. During a median follow-up period of 3.59 years, 152 of 404 patients in the early-start group (37.6%) and 155 of 424 in the late-start group (36.6%) died (hazard ratio with early initiation, 1.04; 95% CI, 0.83 to 1.30; P=0.75). There was no significant difference between the groups in the frequency of adverse events (cardiovascular events, infections, or complications of dialysis)., Conclusions: In this study, planned early initiation of dialysis in patients with stage V chronic kidney disease was not associated with an improvement in survival or clinical outcomes. (Funded by the National Health and Medical Research Council of Australia and others; Australian New Zealand Clinical Trials Registry number, 12609000266268.)

Background: In renal transplantation, the immunosuppressive efficacy of cyclosporine is counterbalanced by its nephrotoxicity. Although cyclosporine improves short-term graft survival, its long-term effects are unclear., Methods: Recipients of first cadaver renal transplants were randomized into three groups between 1983 and 1986: azathioprine and prednisolone alone (AP, n = 158), long term cyclosporine alone (Cy, n = 166), and short-term cyclosporine followed by azathioprine and prednisolone (CyAP, n = 165). All groups received methylprednisolone induction., Results: There were no significant differences in patient survival at 15 years (48 vs. 56 vs. 51%, P = 0.14), and 15-year graft survival (censored for death) in those patients in the CyAP group (47 vs. 44 vs. 59%, P = 0.06) was not significantly different statistically. When deaths or graft losses before 12 months were censored, the differences in 15-year graft survival between the groups were significant (58%, 51%, 70%, P = 0.01). The CyAP group also had lower mean serum creatinine at all time points beyond 3 months posttransplant out to 10 years (143 vs. 169 vs. 131 micromoles/L, P = 0.04). Per protocol analysis, after censoring patients at change in therapy, increased the observed differences in 15-year graft survival between the groups (54 vs. 38 vs. 65%, P = 0.01)., Conclusion: Survival and function of first cadaveric kidney transplants is improved by use of short-term cyclosporine followed by azathioprine and prednisolone. Long-term cyclosporine use reduces long-term graft survival.

Objectives: The primary objective of the IDEAL study is to determine whether the timing of dialysis initiation has an effect on survival in subjects with end-stage renal disease (ESRD). The secondary objectives are to determine the impact of "early start" versus "late start" dialysis on nutritional and cardiac morbidity, quality of life, and economic cost., Design: Prospective multicenter randomized controlled trial. Patients are randomized to commence dialysis at a glomerular filtration rate (by Cockcroft-Gault) of either 10-14 mL/minute/1.73 m2 ("early start") or 5-7 mL/min/1.73 m2 ("late start"), with stratification for dialysis modality (hemodialysis vs peritoneal dialysis), study center, and the presence or not of diabetes mellitus., Setting: Dialysis units throughout Australia and New Zealand., Patients: Patients with ESRD commencing chronic dialysis therapy., Outcome Measures: Three years from randomization, all-cause mortality, morbidity, and economic impact; structural and functional cardiac status, nutritional state, and quality of life will be assessed., Results: To date, 388 patients of a minimum 800 patients have been entered and randomized into the study. Current recruitment rates suggest sufficient patients will be enrolled by December 2004 and follow-up completed by December 2007., Conclusions: The IDEAL study will provide evidence for the optimal time to commence dialysis.

The changes in the haematology and clinical biochemistry associated with the different stages of the menstrual cycle, gestation and lactation in the baboon (Papio hamadryas) were evaluated in a prospective longitudinal study. Serial EDTA and heparin blood samples were collected from 12 baboons. Haemoglobin concentration, haematorcrit, red blood cell and white blood cell counts were decreased in the luteal compared to the follicular phase (P<0.001); the reverse effect was observed for platelet count, total protein and albumin concentrations. The changes in plasma concentrations of sodium, potassium, urea, creatinine and cholesterol and plasma osmolality were characterized by reductions (P<0.01) in early pregnancy which were maintained throughout gestation. Plasma concentrations of total protein, albumin and alkaline phosphatase, as well as haemoglobin, haematocrit and red cell count were reduced (P<0.001) from mid-gestation. Platelet count and plasma calcium concentration fell continuously throughout gestation (P<0.001). Plasma triglycerides were lower and plasma iron was higher (P<0.01) in gestation compared to the phases of the menstrual cycle and lactation. By 1 week post partum, all parameters except haemaglobin had returned to pre-conception levels.

1. The purpose of the present study was to examine the effect of nitric oxide (NO) inhibition on mean arterial pressure (MAP), endothelin (ET) and the renin-aldosterone system in pregnancy in the non-human primate (baboon). 2. Twenty pregnant baboons (Papio hamadryas) were examined prospectively after the administration of an oral NO inhibitor in different phases of pregnancy. Haemodynamic responses to NO inhibition, evidence of pre-eclampsia and the renin-aldosterone system were examined under anaesthesia. 3. Oral NL-nitro-L-arginine (NOLA; 5 or 10 mg/kg) was given for 1 week in early (6-8 weeks gestation), middle (14-16 weeks gestation) and late (22-24 weeks gestation) pregnancy and while non-pregnant. Mean arterial pressure, heart rate, haematology, biochemistry, ET, plasma renin activity (PRA) and aldosterone were measured. Foetal effects of NOLA were also examined by ultrasound and neonatal measurements. 4. Nitric oxide inhibition led to an increase in MAP in non-pregnant animals (9 mmHg) and in middle and later pregnancy (6 and 7 mmHg, respectively). Mean arterial pressure in early pregnancy was not affected. A reduction in PRA occurred after NO inhibition in all stages of pregnancy. Significant proteinuria occurred only in late pregnancy. 5. Nitric oxide is involved in the maintenance of lower blood pressure in late pregnancy and inhibition leads to an increase in blood pressure and proteinuria in the baboon. Nitric oxide insufficiency may contribute to the clinical manifestations of human pre-eclampsia. Nitric oxide was not involved in the normal vasodilation of early primate pregnancy.

A retrospective study evaluated the influence of sex and age on plasma biochemistry and haematology parameters in a captive-bred colony of baboons. Over 1,140 ETDA and heparin blood samples were obtained from 160 clinically normal baboons between the ages of 11 months and 11 years. Data for these blood tests were analysed for the effects of sex, age and sex age interactions. Sex, age and sex age interactions were detected for many plasma biochemistry and haematological parameters. The reference range values for platelets, white-blood cells and mean corpuscular volume and plasma chloride, glucose, total protein and iron were higher (P < 0.01) and red blood cell, plasma sodium, potassium, total CO2, creatinine, urea, total bilirubin, albumin, alkaline phosphate, gamma glutamyl transpeptidase and phosphate were lower (P < 0.01) in the female compared to the male population. Sex age interactions (P < 0.05) were seen with haemoglobin, white blood cells, haematocrit, mean corpuscular volume, sodium, creatinine, urea, calcium, phosphate, total bilirubin, total protein alkaline phosphatase, the liver enzymes and triglycerides. Plasma alkaline phosphatase was highest ( > 800 micro/l) in young juveniles of both sexes; creatinine was higher in older ( > 4 years) compared to younger baboons of the same sex (P < 0.05). Plasma cholesterol and triglycerides were greater (P < 0.01) in young baboons compared to older animals.

To determine whether vigorous treatment with dialysis is of benefit to patients with myeloma-induced renal failure at presentation, we retrospectively reviewed outcomes in a group of patients diagnosed with multiple myeloma between January 1986 and September 1993. Increased age (P = 0.003), presence of renal impairment (P = 0.006), and failure to enter plateau phase (P < 0.001) were independently associated with shortened survival. However, there was no difference in outcome between patients with severe renal failure, those treated with dialysis, and those with milder renal impairment (median survival, 22 months in both groups), nor was reversibility of renal failure associated with any survival advantage. The lack of correlation between severity or reversibility of the renal failure and survival suggests that there may be characteristics of some patients or their underlying myeloma that are responsible both for renal impairment and for adverse prognosis. In this study, neither age, clinical stage, labeling index, nor response to treatment was able to account for the difference in outcome between patients with and without renal failure. The prolongation of life achieved in the dialysis patients such that their median survival was identical with that of the group with milder renal impairment was considered to represent a significant benefit to these patients and to justify the offer of dialysis to all patients requiring it.

This study characterizes the renin-angiotensin-aldosterone system during the normal menstrual cycle in the baboon. Ten animals received a daily dose of an ACE inhibitor or placebo in a randomized blind cross-over design. Data were obtained during the mid-follicular and early luteal phases of normal non-pregnant menstrual cycles. All examinations and blood collections were performed with ketamine sedation: 7-kg by im injection. Blood pressure was recorded by sphygmomanometer. Serum ACE activity was measured by spectrophotometry. Aldosterone (ALDO), angiotensin I (AI), and angiotensin II (AII) were measured by radioimmunoassay. Plasma renin activity (PRA) was measured by AI generation. The renin-angiotensin-aldosterone system was found to be activated in the follicular phase and suppressed during the luteal phase of the normal non-pregnant menstrual cycle in the baboon.

Objectives: Serious concerns have been raised about angiotensin-converting enzyme inhibition in pregnancy. The central question remains: does toxicity of angiotensin-converting enzyme inhibition pertain to pregnant humans?, Study Design: A prospective, placebo-controlled study was performed to investigate the effect of angiotensin-converting enzyme inhibition on pregnancy outcome in the baboon. Subjects (N = 12) received active and placebo treatments sequentially in a crossover protocol. Data were analyzed with two-sample t tests, analysis of variance, Fisher's exact test, or Kaplan-Meier survival analysis, where appropriate., Results: Chronic administration of enalapril (7.5 mg per day) from before conception achieved moderate but sustained angiotensin-converting enzyme inhibition as determined by repeated measures of renin-angiotensin system parameters (serum angiotensin-converting enzyme activity, plasma renin activity and plasma angiotensin I, angiotensin II, and aldosterone concentrations). Serum angiotensin-converting enzyme activity was significantly reduced throughout (< 10 nmol.ml-1.min-1, p < 0.01), with significant increases in plasma renin activity and angiotensin I (p < 0.01). Angiotensin II and aldosterone were maintained unchanged compared with placebo. There was a significant incidence of fetal death or intrauterine growth retardation in fetuses exposed to enalapril (eight of 13, zero on placebo, p < 0.01). When the definition of adverse pregnancy outcome was restricted to fetal death alone (four of 13) the difference remained significant (p < 0.05). Maternal arterial pressure was unchanged before conception, but a small and significant fall (10 to 15 mm Hg, p < 0.01) was detected throughout pregnancy. There was no fetal malformations., Conclusion: The study provides definitive evidence for serious consequences of angiotensin-converting enzyme inhibition in pregnancy of high-order primates.

Plasma pyridoxal-5'-phosphate (PL-5'-P), pyridoxal (PL), pyridoxine (PN), and 4-pyridoxic acid (4-PA) were measured by high-performance liquid chromatography (HPLC) in 39 patients (15 male, 24 female) with chronic fenal failure undergoing regular haemodialysis and 46 healthy controls (28 male, 18 female). All three vitamers of vitamin B6 and the metabolite were significantly elevated in the haemodialysis patients. Mean PL-5'-P and PN concentrations were 20 times the mean in controls. Only one patient took a vitamin B6 supplement. In view of the neurotoxicity of supranutritional intakes of PN in normal humans we suggest that supplements of PN be carefully monitored when administered to patients with chronic renal failure.

A selective cell culture medium, D-valine minimal essential medium (92 mg/l), has been developed to inhibit the proliferation of fibroblasts in cell culture (Gilbert & Migeon 1975). Substitution of D-valine for L-valine prevents fibroblast growth due to the absence of D-amino acid oxidase in these cells. Most cell cultures require foetal bovine serum as an essential component of the culture media, however foetal bovine serum contains L-valine, negating the value of D-valine selective media. To overcome this difficulty, we have produced a modified selective media for cell culture, by the dialysis of foetal bovine serum and confirmed its ability to inhibit fibroblast growth whilst still allowing the proliferation of epithelial cells in culture.

The bioavailability of an oral dose of cyclosporin A (CSA) is variable. CSA is highly lipid soluble with approximately 40% of the CSA in the intravascular compartment bound to lipoproteins. This study was undertaken to determine what effect acute alterations in plasma lipids following a high fat meal would have on CSA whole blood levels 12 to 14 hours after the last dose. Fifteen renal transplant patients with stable renal function and on CSA therapy alone for a minimum of three months were investigated. Anthropometric data was recorded and baseline blood samples were drawn for CSA, liver function, renal function, vitamins A and E. triglycerides, cholesterol and lipoproteins following an overnight fast. The subjects then received a high fat (72.8% of caloric value) or a low fat (12% of caloric value) meal and post-prandial samples were drawn at two and four hours. The correlation between CSA levels (r = 0.72) taken on the two study days (one week apart) was less than expected despite no change in dosage. Cholesterol levels remained unchanged but triglyceride levels rose following the high fat meal. CSA levels did not correlate with the post-prandial changes in triglycerides, nor with any other parameter of lipid metabolism, lipid transport, or total body fat. This study demonstrated that CSA whole blood levels are not influenced by acute variations in lipids following a meal and therefore the time of sampling for a CSA trough level will not be influenced by the proximity to a recent meal.

Objective and Design: The aim of this study was to evaluate treatment of mild to moderate hypertension (less than 170/110 mmHg) in pregnancy in a prospective, randomised, double-blind trial., Setting and Patients: Pregnancy outcome was studied for 52 primigravid women, managed in hospital from early in the third trimester., Interventions: Patients were randomly allocated either to placebo or to active treatment (clonidine plus hydralazine)., Main Outcome Measures and Results: Maternal deterioration dictated withdrawal from trial therapy for eight patients receiving placebo, but for only one receiving active treatment. Maternal proteinuria occurred only in the placebo group. Intention-to-treat analysis showed a significant increase in premature delivery for complications in the placebo group (P less than 0.05), despite active blood pressure treatment for those withdrawn from the group because of severe hypertension (170/110 mmHg or higher). Neonatal respiratory distress requiring intensive care occurred only in babies born to women in the placebo group. There were no perinatal deaths and no adverse effects of treatment in the neonates., Conclusions: The study indicates that early control of mild hypertension in pregnancy can prevent progression to emergency premature delivery.

When one is faced with the problem of essential hypertension it is prudent to pay attention to lifestyle factors, especially alcohol, smoking and obesity. Modification of salt intake in the diet is a simple measure. Drug therapy will need to be long-term therapy and ease of treatment is important, which means that drugs given once a day or at most twice a day should be used. Diuretics and beta-blockers are inexpensive and well proven but have many side-effects. Newer agents may have fewer side-effects but are more expensive. The choice will be an individual one.

This study was designed to investigate aspects of renal xenobiotic metabolism and the renal cellular response to drug-induced injury, in mediating cyclosporine nephrotoxicity. The relation between CsA and renal enzyme activity has not previously been investigated. In this study, CsA induced alterations in rat renal cortical microsomal NADPH cytochrome P-450 reductase activity, microsomal and mitochondrial lipid peroxidation, and renal cortical glutathione levels were investigated. CsA, in vivo (50 mg/kg/day for 4 days), increased in vitro lipid peroxidation in microsomes and mitochondria. CsA produced a significant uncompetitive inhibition of renal NADPH cytochrome P-450 reductase activity. The low activity and maximal enzyme velocity (Vmax) suggest that the amount of renal enzyme available for metabolism may be a rate-limiting step and could contribute to the development of toxicity. CsA in vivo reduced the renal cortical glutathione ratio (GSH/GSSG), which may also reduce the renal cellular response to CsA injury. This study has demonstrated that CsA nephrotoxicity may, in part, be mediated by CsA-induced alterations in renal xenobiotic metabolism.

A method is described for comprehensive hemodynamic study of undisturbed baboons (Papio hamadryas) that incorporates cardiac output measurement by thermodilution. Instrumentation includes arterial, aortic, and central venous catheterization by a surgical technique that does not require entry to peritoneal or thoracic cavities. It provides a means for right atrial indicator delivery with aortic temperature recording of thermodilution curves. Accuracy was confirmed by comparison to measurement by Swan-Ganz catheters. Diurnal variations of systemic arterial pressure in long-term study of conscious baboons were shown to result from significant increases in cardiac output by day (P less than 0.001), despite concomitant falls in systemic vascular resistance. The cardiac output values obtained were 0.13 l.min-1.kg-1 at night and 0.16 l.min-1.kg-1 by day. Comparison of these results to previous reports of cardiac output in baboons highlights the inadequacies of methods that require physical restraint or anesthesia. This technique also leaves the baboons intact for subsequent breeding or experimental use after catheter removal without the need for further surgery.

The total body protein status of 18 patients undergoing regular haemodialysis was assessed by measuring total body nitrogen (TBN) using in vivo neutron activation analysis (NAA). Eighteen healthy controls, who were selected according to their height, age and sex match with the patients were also measured. The male and female patients were both found to have lower mean values for total body protein (P less than 0.01, P less than 0.025 respectively) although they had similar weights compared with their matched controls. Seven patients were measured on further occasions and only two patients showed a change in their body protein. One female showed an increase of 11 per cent in body protein (with an increase of 25 per cent in body weight) after intensive nutritional repletion therapy. In vivo NAA provides a direct means of measuring body protein and is a reliable method to monitor changes with treatment regimes.

The outcome of patients with acute renal failure following cadaveric renal transplant has been evaluated in a prospective, controlled trial, comparing treatment with cyclosporine (CSA) to prednisone, azathioprine, and antilymphocyte globulin (AZA). There was a high incidence of acute post-transplant renal failure in both groups: 37 of 51 CSA and 31 of 45 AZA patients, due to the long exposure of kidneys to warm and cold ischemia. Onset of adequate renal function was delayed for three or more weeks in 27 (53%) CSA and only nine (20%) AZA patients, and the only predisposing factor found was donor hypotension. All nine AZA and 18 of the 27 CSA patients with prolonged oliguria subsequently had a spontaneous diuresis. Nine of the CSA patients were changed to azathioprine and prednisone because of suspected CSA toxicity, and eight of these kidneys began functioning within days, even though they had been oliguric for 21 to 83 days. Of these nine patients, five had adequate long-term function on AZA, three developed CMV infections that were fatal to two individuals, and two rejected their grafts. Plasma CSA levels fluctuated widely in all patients, but were not higher in any group, including those with prolonged oliguria. During the oliguric period, biopsy specimens proved rejection was more common in the nine patients who had their CSA stopped than in the other CSA patients, and seven of these nine developed a diffuse interstitial fibrosis that was thought to be a manifestation of CSA toxicity.(ABSTRACT TRUNCATED AT 250 WORDS)

Ovarian function was assessed in 24 women after renal transplantation who were treated either with cyclosporin A (10 patients) or with a combination of azathioprine and prednisone (14 patients) as immunosuppressive therapy. The different regimens were not associated with any differences in clinical or endocrine indices of ovarian function (LH, FSH, prolactin, testosterone, oestradiol, dehydroepiandrosterone sulphate). Excessive hair growth was common in both treatment groups. Levels of testosterone and dehydroepiandrosterone were higher in cyclosporin-treated women but this was due to prednisone-induced suppression of adrenal androgen output in the azathioprine- and prednisone-treated women. Excessive hair growth was present in postmenopausal women on both treatments suggesting that hypertrichosis is a consequence of renal transplantation and is not a specific side-effect of cyclosporin A therapy.

Two hundred and thirty-six pregnant women were referred for assessment and management of hypertension and/or renal disease. A Unit consisting of a physician, an obstetrician and a perinatologist jointly assessed each patient and advised on management. All patients were hospitalized and at bed rest. Drug therapy was clonidine hydrochloride or methyl dopa and in some patients a vasodilator was added. The decision to deliver was dictated by foetal maturity and wellbeing, in conjunction with maternal condition. There was no maternal mortality and the overall perinatal survival was 97%. The outcome of these pregnancies compares favourably with studies previously reported and reflect a successful approach to management of high risk hypertensive pregnancies.

To test the hypothesis that haemodynamic changes in pregnancy precede any significant increase in circulating blood volume, serial haemodynamic studies were performed in eight baboon pregnancies using Swan-Ganz catheterization and arterial cannulation. Simultaneous measurements were made of red cell and plasma volumes, and of plasma renin activity and aldosterone concentration. Haemodynamic changes identified by 4 weeks gestation included significant (P less than 0.01) reductions in right atrial pressure, systemic and pulmonary arterial pressures, and systemic and pulmonary vascular resistance. Stroke volume increased in early pregnancy (P less than 0.01), with a consequent increase in cardiac output. Plasma renin activity and aldosterone concentration were elevated by 4 weeks (P less than 0.01), but plasma volume did not expand until 12 weeks. At no stage in middle or late pregnancy was cardiac filling pressure increased. These results provide the first haemodynamic evidence that pregnancy is a state of reduced effective blood volume associated with vasodilatation from the early weeks.

Results of arteriographic investigation of patients with deteriorating renal function or poorly controlled hypertension have revealed that thrombosis of the renal artery is not an uncommon exacerbating factor. Seventeen patients with one or more occluded renal arteries had an operation to improve renal function or to control hypertension. Stenosis of the contralateral renal artery was present in addition to the occlusion in four patients. Reconstructive arterial procedures were performed in 15 patients and nephrectomy was performed in two. Eight patients with renal failure had marked improvement in renal function after revascularization of the occluded renal arteries. The group had a mean preoperative serum creatinine value of 7.95+/-1.81 (S.E.) milligrams per cent which fell postoperatively to 3.91+/-1.21 (S.E.) milligrams per cent at a mean follow-up period 20 months. Preoperative control of hypertension was difficult in 16 of the 17 patients. Postoperatively, the blood pressure fell to normal levels in six patients, and in an additional eight patients, it did so with the administration of antihypertension therapy. The hypertension was unchanged in two patients. Plasma renin activity was measured in 14 of the patients with hypertension. It was elevated in 13 patients and normal in one patient. Postoperatively, the blood pressure was unchanged in the patient with normal plasma renin activity, but in 12 of the 13 patients with elevated plasma renin activity, the blood pressure returned to normal levels. It is concluded that patients with occluded renal arteries should be treated surgically. The major benefits of an aggressive approach to this condition are reversal of renal failure and control of hypertension.

A large-area short-time (LAST) haemodialysis regimen (three hours by three times per week on a 2-5 M2 haemodialyser) has been compared with conventional haemodialysis (six hours by three times per week on a 1-3 M2 haemodialyser) on four patients over a period of eight months. Parameters monitored throughout the study included: Serum biochemistries, haematocrit, extra-cellular fluid space, platelet function, granulocyte kinetics, immunological status and neurological status. All patients showed weight increases (3--12%) during the LAST dialysis period. These increases were related to problems of intradialytic hypotension which resulted from the increased rate of fluid removal required during the LAST dialysis period. Hypotension was not a problem during routine dialysis all patients showed an increase of 10--20% (P less than 0-05) in predialysis serum urea and creatinine and a moderate decrease in predialysis serum bicarbonate (from 24-8 +/- 2-2 to 21-4 +/- 2-6 mM/I, P less than 0-005). This study indicates that, providing fluid balance can be controlled, a LAST dialysis regimen provides comparable therapy to conventional haemodialysis. However, recent studies have suggested that short-time dialysis may be possible with conventional 1-0 to 1-3 M2 haemodialysers, indicating that short-time haemodialysis may not need to involve more costly large-area haemodialysers.

1. A rat bioassay was used to study pressor substances in brain extracts. 2. A compound with pressor activity in pentolinium-treated rats was extracted from brain, purified using Dowex, Sephadex electrophoresis and identified as gamma-aminobutyric acid (GABA) by HPLC and mass spectrometry. 3. Intravenous GABA (1-5 microgram) or brain extracts caused a dose dependent decrease in blood pressure in pentobarbitone-anaesthetized rats. 4. After ganglion blockade with pentolinium (2 mg/kg subcutaneously), GABA or brain extracts cause a dose dependent increase in rat blood pressure. 5. This pressor effect is reduced by alpha- and beta-blockers (intravenous phentolamine, 0.5 mg/kg and propranolol, 0.05 mg/kg). 6. It is concluded that GABA causes a fall in blood pressure by a central mechanism and ganglion blockade unmasks a pressor effect.

In the acute clinical situation, CSA produces reversible renal impairment. Studies by Morris et al. [1982] and others indicate that this is rapidly reversible when the drug is ceased. A series of studies have been performed in rats with the aim of examining changes in GFR, together with changes in the intrarenal renin-angiotensin system and renal release of prostaglandins. Rats were treated for 3-7 days with CSA and at the end of the experiment kidneys were removed and renal cortical slices prepared. There was increased renin secretion from the CSA-treated rats, compared to controls, and the response was dose-dependent. There was an increase in renal cortical renin content paralleling the renin release. Determinations of plasma renin in these animals also indicated a rise in plasma renin activity associated with time. In animals not pretreated with CSA, the renal cortical slices incubated with CSA demonstrated a stimulation of renin release. A further group of rats pretreated with 100 mg/kg/day of CSA for 3-7 days showed no change in renal slice release of 6-keto-PGF1 alpha, thromboxane B2, PGE2 and PGF2 alpha. This data indicates that the renal renin-angiotensin system is activated by CSA and produces a dissociation of the linkage between renal slice prostaglandin release and the renin angiotensin system. This would indicate that CSA affects the intrarenal control of GFR. However, the exact site of the modulation remains to be determined.

The distribution of NADPH-dependent quinone reductase and NADPH-cytochrome P-450 reductase activities was determined in the urinary bladders of male and female rabbits. In urinary bladder transitional epithelium (UBTE) and in urinary bladder non-transitional tissue (UBNT) microsomal quinone reductases demonstrated significant (P less than 0.05) sex-dependent differences in the case of both dicoumarol-insensitive (male greater than female) and dicoumarol-sensitive or DT-diaphorase (female greater than male) activities. Microsomal NADPH-cytochrome P-450 reductase activities in UBTE and in UBNT were found to be similar in male and female rabbits. The activities of microsomal and cytosolic quinone reductases and the activity of microsomal NADPH-cytochrome P-450 reductase in UBNT were much lower than those in UBTE. NADPH-cytochrome P-450 reductase and similar flavo-enzymes activate quinones via one-electron reduction into semiquinone free radicals, which then react with molecular oxygen, forming superoxide anions. DT-diaphorase acts as a detoxifying enzyme by converting many quinones via a unique two-electron reduction into less reactive hydroquinones, enabling their excretion as water-soluble conjugates. Since UBTE contains substantial activities of prostaglandin H synthase (PHS) and NADPH-cytochrome P-450 reductase, unlike UBNT, the toxicity and carcinogenicity of xenobiotics which are either quinones or form quinones in situ through the mediation of PHS would be high in UBTE. The risk of carcinogenicity of quinones in UBTE would be higher in male rabbits than in female rabbits due to sex-dependent differences in the relative proportions of the one-electron reduction pathway, represented by NADPH-cytochrome P-450 reductase, and the two-electron reduction pathway, represented by DT-diaphorase (female greater than male).

The antihypertensive actions of the beta-adrenergic blocking agent, prindolol, and of the diuretic, hydrochlorothiazide, were analysed in a double-blind randomized 2 X 2 factorial trial in 16 patients. There were four eight-week phases in which patients received prindolol alone, hydrochlorothiazide alone, prindolol plus hydrochlorothiazide in combination, and no treatment. Both drugs were given in fixed doses: prindolol, 10 mg three times per day; hydrochlorothiazide, 50 mg per day. Blood pressure was measured weekly, alternately at the outpatient clinic and at home. Supine mean arterial pressure (MAP) in resting patients fell from 127 mm Hg in the placebo phase to 117 mm Hg with hydrochlorothiazide alone, 116 mm Hg with prindolol alone, and 111 mm Hg with the combination of prindolol and hydrochlorothiazide. (The standard error of difference between treatments was +/-3-58). A mean factorial effect of -7 mm Hg for hydrochlorothiazide (P less than 0-01) and -8 mm Hg for prindolol (P less than 0-01) was obtained, and the two drugs acted in an additive manner. The effects on standing blood pressure in resting patients were similar. No serious side effects were noted.

The effect of Cyclosporin A (CyA) on renin storage and release in rats was investigated. Renin release from incubated renal cortical slices was increased in rats treated with 25 or 50 mg/kg/day of CyA for 3 to 7 days. This was associated with an increase in renal cortical renin content, which was also increased over the same time period. Plasma renin activity was similarly elevated in these rats. It is possible that these increases in renin are related to the nephrotoxicity of CyA.

Nephrotoxicity is a major side effect of cyclosporin A (CSA) when used in renal transplantation, and the distinction between nephrotoxicity and rejection is important in patient management. One hundred twenty-five renal biopsies were examined from 56 patients entered into a controlled clinical trial aimed at comparing the efficacy of CSA therapy alone to a combination of prednisone, azathioprine, and antilymphocyte globulin (AZA). In order to define the histopathology of rejection and nephrotoxicity, all the biopsies were evaluated in a semiquantitative manner by an observer unaware of the clinical state of the patient. Comparison of the morphological appearances of 32 biopsies from patients on CSA, and 22 biopsies from AZA-treated patients performed during clinically apparent rejection episodes showed that the histological patterns of rejection were the same in both treatment groups. Comparison of the morphological features of 34 biopsies from patients receiving CSA and 13 from patients receiving AZA, performed during prolonged periods of post-transplant renal failure, who eventually recovered on continuation of original therapy, showed that there were no morphological features specific to the CSA-treated group. Five patients on CSA had oliguria which was prolonged by CSA nephrotoxicity. Thirteen biopsies from all five patients showed a diffuse interstitial fibrosis that was peculiar to this group of patients.