Shaul M. Shasha

Estimation of quantitative proteinuria by using the protein-creatinine ratio in random urine samples.

The protein-creatinine ratio was measured in urine samples obtained at three different times of the day and compared to the 24-hour protein excretion in 51 patients with a wide spectrum of renal function and proteinuria. A linear correlation, which was highly significant, was found between the two variables. The higher correlation was found in urine samples obtained at 08.00 and at 12.00 h and the lowest in samples obtained at 16.00 h. This correlation did not depend on the degree of proteinuria or on the sex of the patients, but was slightly dependent on the glomerular filtration rate. The protein-creatinine ratio was essentially identical with the 24-hour protein excretion. Thus, the normal range of proteinuria was represented by a ratio of less than 0.2, while nephrotic patients had a ratio above 3.5. We suggest that the protein-creatinine ratio in random urine samples could replace the timed collection methods at least for follow-up and screening.

Interaction between Erythropoietin and Peripheral Polymorphonuclear Leukocytes in Hemodialysis Patients

The effect of erythropoietin (EPO) on the oxidative stress and inflammation caused by polymorphonuclear leukocytes (PMNLs) in chronic hemodialysis (HD) patients was investigated in vivo and in vitro. The studies were performed on isolated PMNLs from peripheral blood of healthy controls and HD patients before and following 6 weeks of EPO treatment. The oxidative stress was expressed by the rate of superoxide release from phorbol 12-myristate 13-acetate stimulated PMNLs, and the inflammatory state was evaluated by in vitro PMNL survival, in addition to white blood cell and PMNL counts of the enrolled subjects. Following 6 weeks of EPO treatment, in HD patients, the rate of superoxide release from PMNLs as well as WBC and PMNL counts fell significantly when compared with the pretreatment values. PMNLs from HD patients and healthy controls incubated in vitro with increasing amounts of EPO displayed a significant reduction in their rates of superoxide release and a significant improvement in survival. We have concluded that EPO interacts with PMNLs, attenuating their primed state in HD patients, thus reducing oxidative stress and the extent of inflammation. To the best of our knowledge, this attenuation of the primed state of PMNLs by EPO is a new finding.

Effect of oxygen tension on activity of antioxidant enzymes and on renal function of the postischemic reperfused rat kidney.

The aim of the present study was to examine the effect of exposing animals to 100% oxygen instead of room air on renal function and endogenous antioxidant enzymes of the postischemic reperfused rat kidney. Superoxide dismutase (SOD), catalase and glutathione peroxidase (GPX) were determined in the homogenate of the left kidney after 45 min of ischemia, caused by clamping the left renal artery, 10 and 90 min after reperfusion while the animals breathed room air or 100% O2. The right kidney served as a control. The possible influence of trapped blood in the clamped kidney was also investigated by the use of a correction factor based on the Hb concentration in the homogenate. The results indicate that such correction is necessary as the blood adds significant antioxidant activity. The activities of all 3 enzymes after 45 min of ischemia decreased significantly in the left (ischemic) compared to the right (control) kidney, to 64% of the control levels for catalase, 58% for SOD and 49% for GPX. After 10 min of reflow, a further decrease in the activities of catalase (to 49%) and of GPX (to 29%) was found. SOD activity, however, increased to 64%. After 90 min of reperfusion, restoration toward normal levels was noticed (SOD activity increased to 70%, catalase to 76% and GPX to 58%). Breathing 100% O2 resulted in a significant decrease in all enzyme activities (to 38.6% for catalase, 45% for SOD and to 27.4% for GPX). This inactivation can be explained by increased reactive oxygen species (ROS) activity during hyperoxia.(ABSTRACT TRUNCATED AT 250 WORDS)

A link between polymorphonuclear leukocyte intracellular calcium, plasma insulin, and essential hypertension

BACKGROUND Intracellular ionized calcium ([Ca2+]i) is a key mediator in the activation and oxidant production by peripheral polymorphonuclear leukocytes (PMN). Primed PMN contribute to oxidative stress (OS) and inflammation in essential hypertension (EH). Elevated [Ca2+]i has been described in insulin-resistant states and in various cell types in EH but not in EH PMN. The aim of this study was to evaluate the levels of [Ca2+]i in peripheral EH PMN in relation to plasma insulin levels and blood pressure (BP). METHODS The PMN were separated from blood of 20 nonsmoking, nonobese untreated EH patients, age range 20 to 60 years and from 20 age- and gender-matched healthy individuals (NC). Plasma glucose and insulin levels 2 h after a 75-g oral glucose load, reflected insulin resistance. PMN [Ca2+]i was measured by flow cytometry in isolated cells stained with Fluo-3. RESULTS The EH PMNs showed significantly increased [Ca2+]i compared to NC PMN. Eighty percent of EH patients showed significantly higher plasma insulin levels after glucose load. Linear regression analysis showed significant correlation between 1) PMN [Ca2+]i and mean arterial pressure (MAP) (r = 0.5, P < .006); 2) PMN [Ca2+]i and fasting plasma insulin (r = 0.7, P < .005); and 3) fasting plasma insulin and MAP (r = 0.4, P < .04). CONCLUSIONS This study adds PMN to previously described cells exhibiting elevated [Ca2+]i, contributing to OS and inflammation. The correlation of individual BP with both PMN [Ca2+]i and plasma insulin levels, together with the fact that elevated [Ca2+]i mediates PMN priming, suggest that elevated [Ca2+]i and insulin are involved in the pathogenesis of hypertension-induced vascular injury in EH.

Short-Term Effect of Erythropoietin on T-Cell Mitogenic Proliferation in Chronic Renal Failure Patients

Uremic patients undergoing hemodialysis (HD) are known to be highly susceptible to infections. Recent data indicate that in addition to its well-known stimulating effects on red cell production, erythropoietin (EPO) may also have immunomodulating properties. The aim of this study was to examine the effect of EPO on lectin-induced T-lymphocyte transformation in uremic patients, as part of its effect on the immune response. Sixteen HD patients and 20 age- and sex-matched healthy controls were compared before and after 6 and 20 weeks of EPO treatment. T lymphocytes were analyzed for their mitogenic activity following treatment with phytohemagglutinin (PHA), concanavalin A (CON A) and anti-CD3 by measuring 3H-thymidine incorporation. HD patients showed reduced mitogenic responses to all mitogens tested, compared to healthy controls. During the 6 weeks of EPO administration, a significant increase in T-lymphocyte activity could be demonstrated following exposure to all three mitogens (PHA, from 32 +/- 2 to 45 +/- 8; CON A, from 11 +/- 3 to 25 +/- 9; anti-CD3, from 11 +/- 3 to 22 +/- 5, means +/- SD). This increase was augmented after 5 months of EPO treatment. We conclude therefore that EPO improves in vitro T-cell mitogenic proliferation, even after short periods of treatment.

Interaction between Erythropoietin and Peripheral Polymorphonuclear Leukocytes in Continuous Ambulatory Dialysis Patients

The effect of erythropoietin (EPO) on the oxidative stress (OS) and inflammation caused by polymorphonuclear leukocytes (PMNLs) in end-stage renal failure patients undergoing continuous ambulatory peritoneal dialysis (CAPD) was investigated in vivo and in vitro. The studies were performed on isolated PMNLs from peripheral blood of CAPD patients before and following 6 weeks of EPO treatment and from healthy controls. OS was expressed by the rate of superoxide release from phorbol 12-myristate 13-acetate (PMA) stimulated isolated PMNLs and the inflammatory state was evaluated by PMNL counts of the enrolled subjects. Following 6 weeks of EPO treatment in CAPD patients, both the rate of superoxide release from PMNLs and PMNL counts fell significantly when compared with the pretreatment values. In vitro incubation of PMNLs from CAPD patients with increasing amounts of EPO displayed a significant reduction in their rates of superoxide release. EPO, by direct interaction with PMNLs, attenuated their primed state, causing reduction in oxidative stress and inflammation.

Histochemical Studies of Progressive p53 Mutations during Colonic Carcinogenesis in Sprague-Dawley Rats Induced byN-Methyl-N-Nitro-Nitrosoguanidine or Azoxymethane

We studied the increasing expression of the p53 tumor suppressor gene in Sprague-Dawley rats, chemically induced to develop colon cancer. p53 expression was evaluated histochemically at various stages of tumor progression (during a period of 40 weeks) that can be followed by colonic hyperproliferation labeled by 3H-thymidine incorporation. We found that high level nuclear expression of p53 protein correlates with progression of malignancy in carcinogen-induced animals, whereas cytoplasmic staining is related to the onset and early development of malignancy.

Effect of Parathyroidectomy on T Cell Functions in Patients with Primary Hyperparathyroidism

The notion that parathyroid hormone (PTH) can serve as an immunomodulator was examined. T cell function tests were performed in 3 patients with primary hyperparathyroidism before and 1 month after parathyroidectomy (PTX). Three normal volunteers, age and sex matched, were used as controls. One patient with lipoma of the neck was also examined before and after surgical removal of the lesion. In the primary hyperparathyroidism patients the total T cells were lower, the suppressors were higher and the helper to suppressor ratio was significantly lower than in control subjects. The lectin-stimulated lymphocyte transformation was significantly inhibited. All these abnormalities were restored to normal after PTX. Depressed lymphocyte activity was found also in the patient with lipoma. However, no change occurred after surgery. These results support the assumption that excess blood levels of PTH may have an immunosuppressive effect.

Red cell filterability in cigarette smokers and its relations to cardiac hypertrophy

The relationship among daily cigarette consumption, washed and non-washed RBC filterability time (FT) as an indicator of erythrocyte deformability and echocardiographic left ventricular mass (LVM) were examined in 25 clinically healthy smokers and in 25 non-smoking controls matched for sex and age. FT of non-washed RBC was significantly higher in smokers than in non-smokers (25.2 +/- 3.6 vs. 16.8 +/- 2.2 min, P < 0.001). A highly significant linear correlation between number of cigarette consumption and FT was found. These differences were not observed when RBC were washed three times with isotonic saline. LVM was significantly greater in smokers (85.5 +/- 13.4 g/m2) than in controls (61.8 +/- 6.7 g/m2, P < 0.001). A linear correlation between daily cigarette consumption and LVM was observed. A positive relationship between LVM and FT of non-washed RBC was also found. These results demonstrated that LVM is significantly elevated in smokers and is linearly correlated with both cigarette consumption and RBC filtratibility. The increased deformability found in smokers may be a determinant to the cardiac hypertrophy. The association of both elevated LVM and rheological impairment may indicate unfavourable prognosis.

PROLIFERATIVE RESPONSE OF T LYMPHOCYTES TO MITOGENIC LECTINS IN ESSENTIAL HYPERTENSION

Several studies in human and experimental models indicate the existence of a partial relationship between essential hypertension (EH) and the immune system. In this study, cellular immune functions were investigated in 13 patients with untreated and uncomplicated essential hypertension (EHP) and in 10 of their offspring (EHO) and compared to 13 age- and sex-matched normotensive controls (NC) and 10 of their offspring (NCO). The total number of T cells and T cell subsets were similar in all groups examined. In the EHP, basal lymphocyte transformation without lectins was significantly lower (1,126 +/- 261 cpm of [3H]-thymidine uptake) than in the NC (3,223 +/- 736, p less than 0.01); the response to both phytohemagglutinin (PHA) and concanavalin A (ConA) revealed reduced [3H]-thymidine uptake as compared with NC (21,890 +/- 5,432 compared to 64,574 +/- 9,723 for PHA and 10,488 +/- 2,621 compared to 37,334 +/- 8,148 for ConA, respectively, p less than 0.01). However, the ability to proliferate as a response to lectins was normal. This was leading to a normal stimulation index in both groups. In the EHO, non-significant decrease in basal transformation and reduced uptake with PHA (49,537 +/- 7,478) versus NCO (69,911 +/- 7,254) and NC (64,574 +/- 9,723) were found. These findings suggest that the proliferative response of T lymphocytes is partially suppressed in EH.