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Biomedical subjects

G Boner

Publications and source records attributed to G Boner.

At least 37 records · Page 2Linked to original sources
PubMed1997

Serum and renal IGF-I levels after uninephrectomy in the rat.

The hypertrophy of the remaining kidney following uninephrectomy (UNx) has been related to an increase in renal insulin growth factor-I (IGF-I) content. However, while the increase in renal IGF-I lasts for only days after UNx, renal hypertrophy continues for months. In the present study we investigated whether IGF-I also plays a role in the late post uninephrectomy growth of the remaining kidney. Renal IGF-I in the remnant kidney was greater than that of control kidneys (78.3 +/- 17.3 vs 56.0 +/- 14.0 pmol g-1; p < 0.05) 3 days after UNx, tended to remain higher 30 days after UNx (83.8 +/- 23.6 vs 57.3 +/- 14.5 pmol g-1; p = 0.07), but was similar to that of the control kidney when examined 60 days after UNx (66.6 +/- 15.6 vs. 70.4 +/- 6.7 pmol g-1). Serum IGF-I in uninephrectomized rats was similar to that of controls 3 days after UNx, started to increase above the control level at day 10 after UNx and remained higher 30 and 60 days after UNx (75.9 +/- 6.9 vs. 48.7 +/- 7.3 nmol l-1 at 30 days, and 81.2 +/- 13.7 vs 52.9 +/- 11.0 nmol l-1 at day 60, p < 0.05 for both). The kidney weight of uninephrectomized rats was higher by 21% than that of controls 3 days after UNx, by 45% 30 days after UNx and by 63% 60 days after UNx (p < 0.05 for all three observations). At the end of the study, the glomerular volume of uninephrectomized rats was higher by 36% than that of the controls (p < 0.05) We suggest that in the rat, while the initial post uninephrectomy hypertrophy of the remnant kidney is associated with and most probably mediated by an increase in renal IGF-I, the hypertrophy that persists in later post UNx periods is associated with and may be mediated by an increase in serum IGF-I.

Animals↗
PubMed1997

Prednisone dosage and pregnancy outcome in renal allograft recipients.

BACKGROUND: The literature contains reports of 2309 pregnancies in some 1600 women who have undergone renal transplantation. Certain pre-pregnancy factors, especially hypertension, renal graft dysfunction, short interval between transplant and pregnancy, and high immunosuppressive drug dosage, appear to increase the neonatal risks. METHOD: We describe the outcome of 42 pregnancies in 27 allograft recipients at Rabin Medical Center (Beilinson Campus) in Israel during the last 8 years. All were treated with combination immunosuppression regimens. RESULTS: The average interval from transplantation to conception was 3.7 +/- 0.4 years (2 months to 9 years). Rejection episodes occurred in 37% prior to pregnancy but in none during or immediately after pregnancy. Twenty-eight percent of the pregnancies ended in therapeutic or spontaneous abortions, and 29 of the 30 deliveries ended in a live birth. The prematurity rate (63%) was similar to that described in the literature for this patient group. Renal deterioration was evident in seven women (26%) within 2 years after delivery. Use of 7.5 mg/d prednisone (vs. 10 mg/d) before pregnancy was observed as the most significant preconception parameter related to better pregnancy outcome. A long interval from transplantation to conception and lack of pre-existing hypertension were also significant. CONCLUSION: The better pregnancy outcome associated with lower prednisone dosage is probably related to the fact that the patients selected to receive the low-dose regimen have had a longer and less complicated post-transplantation course.

Abortion, Spontaneous↗
PubMed1997

Circulating aggregated platelets, number of platelets per aggregate and platelet size in chronic dialysis patients.

The accelerated arteriosclerosis of chronic dialysis patients is multifactorial. Both non-uremic patients with atherosclerosis and uremic patients have functional platelet abnormalities. Our aim was to study platelet function in chronic dialysis patients and to correlate the findings with the presence of cardiovascular morbidity. Fifty-three chronic dialysis patients were examined. The presence of risk factors for cardiovascular disease (CVD) was recorded, and the patients were examined for the presence of ischemic heart disease, peripheral vascular disease and cerebrovascular accident. The parameters of platelet function, which were examined with the modified Wu and Hoak method, included platelet number, percentage of totally, reversibly and irreversibly aggregated platelets, average number of platelets per aggregate and percentage of large platelets. Significant differences were found between totally aggregated platelets, reversibly and irreversibly aggregated platelets, the percentage of large platelets (p < 0.0001) and the average number of platelets per aggregate (p < 0.001) in dialysis patients compared with control persons. There was no difference between the 2 groups in platelet count. No differences were found between hemodialysis and peritoneal dialysis groups, and the duration of dialysis treatment had no effect. We conclude that platelet abnormalities evident in chronic dialysis patients are a part of the multifactorial etiology of advanced CVD and may predispose dialysis patients to CVD.

Arteriosclerosis↗
PubMed1996

Microalbuminuria as an early predictor of hypertensive complications in pregnant women at high risk.

The value of microalbuminuria in predicting hypertensive complications in pregnant patients at high risk was tested in a prospective trial. A secondary aim was to compare the urinary albumin excretion rate between high risk hypertensive pregnant patients (study group) and pregnant patients at high risk of other complications, normal pregnant subjects, and nonpregnant subjects. Over the last 5 years, 276 patients were studied (142 in the study group v 134 controls). Albumin was measured in an 8-hour overnight urine collection throughout pregnancy using a radioimmunoassay technique. The pregnant women in both the study and control groups demonstrated a statistically significant increase in albumin excretion rate in the second and third trimesters compared with the first. Mean albumin excretion rate values were significantly higher in the study group (P = 0.0001). Using logistic and linear regression models, the presence of microalbuminuria in the early third trimester was proven to be predictive of hypertensive complications (odds ratio, 2.1; confidence intervals, 1.26 to 3.53) and birth weight (R2 = 0.7, P < 0.05) in the study group. Intrauterine growth retardation and neonatal outcome were less predictable. With the introduction of radioimmunoassays and in light of these significant clinical results, we believe that high-risk patients in whom abnormal proteinuria develops usually have a microalbuminuric phase weeks earlier, and this test has some predictive value for severe disease. In addition, the accepted definition of gestational proteinuria should be reconsidered.

Adult↗
PubMed1996

Hospitalizations in dialysis end-stage renal failure patients.

The cost of treating end-stage renal failure (ESRF) patients includes not only the cost of dialysis and related medications but also the cost of hospitalizing these patients. This study examines the hospitalization rate in ESRF patients. During 1993, 126 ESRF patients were dialyzed in our institution. All hospitalizations were recorded. The study included 213 hospitalizations in 91 patients (mean 1.7 hospitalizations/patient/year). The mean length of each hospitalization was 4.8 +/- 5.6 days. Seventy-six hospitalizations were for 1 day. Access (vascular and peritoneal) was the main cause (31%), but these admissions accounted for only 8.7% of days in hospital, while cardiovascular and infections represented 38 and 29%, respectively. No correlation was found between type of dialysis, sex and erythropoietin use and hospitalization rate. 46.5% of admissions were uremia-dialysis related but they accounted for only 30% of the days in hospital. Age and the presence of diabetes mellitus correlated with hospitalization not related to uremia and/or dialysis. Thus, most of the time spent in hospital was secondary to conditions unrelated to uremia and/or dialysis. Efforts should be made to reduce the dialysis-uremia-related hospitalizations and thus reduce the cost of treatment.

Adult↗
PubMed1996

Impairment of the postural venoarteriolar response in young type 1 diabetic patients. A study by laser doppler flowmetry.

The skin blood flow and venoarteriolar response (VAR) in the feet of the young type 1 diabetic patients were studied with laser Doppler flowmetery. The findings were correlated with diabetic microangiopathy in 24 young patients without neuropathy--14 with diabetic microangiopathy, 10 without--and 10 healthy controls. In type 1 diabetic patients and skin blood flow, after lowering of the leg, was significantly higher in the microangiopathic patients than in the healthy controls, 5.3 +/- 1.4 vs 3 +/- 1.5, (P < 0.01). The VAR index was significantly lower in both groups of diabetics as compared with controls. In conclusions laser Doppler flowmetry is an easy and reliable noninvasive technique to evaluate skin blood flow abnormalities in the the feet of young type 1 diabetic patients, including those without neuropathy. The VAR has been found abnormal in the feet of young diabetic patients with and without microangiopathy, regardless of the presence of peripheral neuropathy.

Adolescent↗
PubMed1996

Ovarian angiotensin-converting enzyme activity in humans: relationship to estradiol, age, and uterine pathology.

The present study was designed to measure angiotensin-converting enzyme (ACE) activity in the human ovary and in serum and to relate this activity to age, serum estradiol levels, and uterine and endometrial pathology. ACE activity was determined in 56 females by a radiometric assay using [3H]hippuryl-glycyl-glycine as substrate. Ovarian ACE activity, but not serum ACE, was found to increase with age (P < 0.01) and was significantly greater in postmenopausal subjects (n = 31; 1.35 +/- 0.05 nmol/mg.min) than in subjects with active ovaries (n = 21; 0.65 +/- 0.2 nmol/mg.min; P = 0.0033). Ovarian ACE activities in fertile women in the preovulatory phase (n = 14) and the postovulatory phase (n = 7) were not statistically different (0.66 +/- 0.23 and 0.63 +/- 0.17 nmol/mg.min, respectively). Serum ACE activities were similar in females with active and nonactive ovaries (87.6 +/- 5.0 vs. 81.7 +/- 5.3 nmol/mL-min, respectively). Serum estradiol levels in fertile women were significantly higher than those in postmenopausal women (P = 0.0023). Serum estradiol levels were negatively correlated with age (r = -0.46; P = 0.0041) and were not correlated with either serum ACE activity (r = 0.080; P = NS) or ovarian ACE activity. In summary, human ovarian ACE activity, but not serum ACE, is positively correlated with age. Serum estradiol levels decrease with age, but are not correlated with either ovarian or serum ACE activity. Endogenous serum estradiol levels had no apparent effect on ovarian or serum ACE activity. The presence of uterine pathology affects ovarian ACE activity. The cause of the increased ovarian ACE activity is not clear, but may be related to the aging process.

Adult↗
PubMed1996

Renal effects of moderate hypercholesterolaemia in uninephrectomized rats.

Animal studies have shown that a 4-6-fold increase in serum cholesterol aggravates pre-existing renal injury. We studied the renal effects of moderate hypercholesterolaemia over a period of 18 weeks in uninephrectomized rats. Animals were allocated to two groups; the group 1 rats were fed a normal diet, as controls, and the group 2 rats were fed a high cholesterol diet containing 3% cholesterol and 1% sodium cholate by weight. The serum total cholesterol was higher in group 2 than in controls being 2.5 +/- 0.4 vs. 1.0 +/- 0.1 mmol l-1 at 9 weeks and 2.1 +/- 0.3 vs. 1.1 +/- 0.2 mmol l-1 at 18 weeks (p < 0.05 for both). Serum high density lipoprotein cholesterol levels were similar in both groups. The mean systolic blood pressure was higher in group 2 than in controls, at 145 +/- 9 vs. 137 +/- 8 mmHg (p < 0.05) by 13 weeks and 146 +/- 6 vs. 136 +/- 4 mmHg (p < 0.05) at 18 weeks. Serum creatinine and glomerular filtration rates were similar in both groups. Urine protein excretion remained within the normal range in both groups. Histological examination at 18 weeks showed diffuse fatty changes in the liver cells and prominent vacuolization of renal tubule cells in the group 2 rats. Nevertheless, the glomeruli were normal. There was no significant difference in mean glomerular volume between group 2 rats (1.20(-3) +/- 0.09(-3) mm3) and controls (1.36(-3) +/- 0.10(-3) mm3). Thus moderate hypercholesterolaemia for 18 weeks in uninephrectomized rats resulted in a mild elevation in blood pressure, but did not affect glomerular volume or glomerular histology, in spite of the deleterious effects on liver and renal tubule cells. We assume that extremely high levels of serum cholesterol are required to induce glomerulosclerosis in the rat.

Animals↗
PubMed1996

Sodium-lithium countertransport: a predictor of diabetic nephropathy in Jewish insulin-dependent diabetes mellitus patients of different ethnic origin?

Diabetic nephropathy in Jewish insulin-dependent diabetes mellitus (IDDM) patients has been found to correlate to their ethnic origin. It has also been found that increased sodium-lithium countertransport (SLC) in erythrocytes, as a genetic marker for essential hypertension, may identify those patients at risk for diabetic nephropathy. The purpose of this study was to investigate a possible correlation between this genetic marker and the ethnic origin of Jewish IDDM patients and their parents and the risk for developing diabetic nephropathy. Although SLC was slightly increased in IDDM patients with microalbuminuria, SLC was not correlated with the existence of diabetic nephropathy nor with the ethnic origin and blood pressure of these Jewish IDDM patients. Thus, other genetic factors may play a role in the different prevalence of diabetic nephropathy in Jewish IDDM patients of different ethnic origin.

Adult↗
PubMed1996

Protein turnover in the hypertrophying kidney.

To establish whether altered proteolysis contributes to the increase in protein content in hypertrophying kidneys, we studied protein turnover in proximal renal tubules isolated from rats with three forms of renal hypertrophy, diabetes mellitus (DM), ammonium chloride-induced acidosis and compensatory renal growth (CRG). We found that in DM and in chronic acidosis the normal balance in protein turnover is altered due to attenuated proteolysis and accelerated protein synthesis. Together this favors an increase in kidney protein content. In contrast, in CRG, the increase in protein content is entirely due to increased protein synthesis. Thus, the changes in protein turnover leading to the net gain in kidney protein content in renal hypertrophy depends on the cause of hypertrophy.

Acidosis↗
PubMed1996

Microalbuminuria as an early marker of severity in hypertensive pregnant women.

The value of microalbuminuria in predicting hypertensive complications in pregnant patients at high risk was tested in a prospective trial. A total of 276 patients were studied (142 in the study group vs 134 controls). Albumin was measured in 8-h overnight urine collection throughout pregnancy using radioimmunoassay technique. The pregnant women, in both the study and control groups demonstrated a statistically significant increase in albumin excretion rate in the second and third trimester compared with the first. Using logistic and linear regression models, the presence of microalbuminuria in the early third trimester was proven to be predictive of severe disease (odds ratio 2.1, confidence interval (CI) 1.26-3.53) and birth weight (R2 = 0.7, P < 0.05) in the study group. Intrauterine growth retardation and neonatal outcome were less predictable. With the introduction of radioimmunoassays, we believe severe disease can be predicted by detecting microalbuminuria in the early third trimester of pregnancy in high risk patients.

Adult↗
PubMed1996

Pregnancy outcome in renal allograft recipients in Israel.

The literature contains reports of 2,309 pregnancies in some 1,600 women who have undergone renal transplantation. Certain pre-pregnancy factors, especially hypertension, renal graft dysfunction and short interval between transplant and pregnancy, appear to increase the neonatal risks. We describe the outcome of 42 pregnancies in 27 allograft recipients at Beilinson Medical Center in Israel during the last 8 years. All were treated with combination immunosuppression regimens. The average interval from time of transplantation to conception was 3.7 +/- 0.4 years (2 months to 9 years). Rejection episodes occurred in 37% prior to pregnancy but in none during or immediately after pregnancy. Of the 42 pregnancies 28% ended in therapeutic or spontaneous abortions, and 29 of the 30 deliveries ended in a life birth. The prematurity rate (65%) was similar to that described in the literature. Renal deterioration was evident in seven women (26%) within 2 years after delivery. Despite this significant success rate, pregnancy in organ transplant patients should still be considered high risk.

Adult↗
PubMed1996

Progression of renal disease--can it be reversed? The role of calcium channel blockers and angiotensin-converting enzyme inhibitors.

The treatment of patients with end-stage renal failure using dialysis has become an important factor in the health budgets of the developed countries. Thus, prevention of progression of renal disease and a reduction in the number of patients requiring dialysis should have a beneficial impact on health budgets. This review will examine the effects of calcium channel blockers (CCBs) and angiotensin-converting enzyme inhibitors (ACE-Is) on the progression of renal disease. Both CCBs and ACE-Is have been shown to slow progression in various animal models of various renal diseases. In the human with diabetic and non-diabetic renal disease, most CCBs have caused a stabilization of renal function and in some cases a decrease in proteinuria. ACE-Is have been effective in reducing proteinuria and stabilizing renal function in both diabetic and non-diabetic disease, this effect being independent of the antihypertensive effect. There are good theoretical reasons for using a combination of these two classes of medications, but there are still insufficient clinical data. In summary, both CCBs and ACE-Is may be used to slow the progression of renal disease. ACE-Is seem to be preferable, but there may be an advantage to the use of a combination of both agents.

Angiotensin-Converting Enzyme Inhibitors↗