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Biomedical subjects

J Manitius

Publications and source records attributed to J Manitius.

At least 19 recordsLinked to original sources
PubMed2001

Selenium and glutathione levels, and glutathione peroxidase activities in blood components of uremic patients on hemodialysis supplemented with selenium and treated with erythropoietin.

Patients with chronic renal failure (CRF) often have reduced concentrations of selenium (Se) and lowered activities of glutathione peroxidase (GSH-Px) in blood components. The kidney is a major source of plasma GSH-Px. We measured Se and glutathione levels in blood components and red cell and plasma GSH-Px activities in 58 uremic patients on regular (3 times a week) hemodialysis (HD). The dialyzed patients were divided in 4 subgroups and were supplemented for 3 months with: 1) placebo (bakers yeast), 2) erythropoietin (EPO; 3 times a week with 2,000 U after each HD session), 3) Se-rich yeast (300 microg 3 times a week after each HD), and 4) Se-rich yeast plus EPO in doses as above. The results were compared with those for 25 healthy subjects. The Se concentrations and GSH-Px activities in the blood components of dialyzed uremic patients were significantly lower compared with the control group. Treatment of the HD patients with placebo and EPO only did not change the parameters studied. The treatment with Se as well as with Se and EPO caused an increase in Se levels and red cell GSH-Px activity. Plasma GSH-Px activity, however, increased only slowly or did not change after treatment with Se and with Se plus EPO. In the group treated with Se plus EPO the element concentration in blood components was higher compared with the group supplemented with Se alone. The weak or absence of response in plasma GSH-Px activity to Se supply indicates that the impaired kidney of uremic HD patients has reduced possibilities to synthesize this enzyme.

Adolescent↗
PubMed2001

Selenium, glutathione peroxidases, and some other antioxidant parameters in blood of patients with chronic renal failure.

In the present study several parameters associated with oxidative stress were examined in the blood of 25 chronic renal failure (CRF) patients and the results were compared with 18 healthy subjects. Mean creatinine concentration in patients was 1,216 +/- 292 micromol/l. Selenium (Se) concentration in red cells, whole blood and in plasma of CRF patients (106 +/- 32.5, 59.0 +/- 16.7 and 42.4 +/- 13.8 ng/ml, respectively) was significantly (0.0001 < P 0.01) lower (by 20-42%) compared with the controls. Red cell and plasma glutathione peroxidase (GSH-Px) activities (16.6 +/- 3.4 U/g Hb and 93.7 +/- 32.9 U/l plasma) were lower by 12 and 53% (P < 0.05 and < 0.0001, respectively) in patients than in healthy subjects. GSH concentration in red cells of patients (2.81 +/- 0.45 mmol/l) was significantly (P < 0.001) higher (by 20%) than in control group. Malonyldialdehyde (MDA) concentration (expressed as thiobarbituric acid-reactive substances) in red cells of patients (725 +/- 155 nmol/g Hb) was significantly (P < 0.001) higher (by 28%) than in control group. No significant difference was observed in the activity of superoxide dismutase in pLasma between the two groups. In conclusion, our results confirm that the aLterations in Se levels in blood components and in GSH-Px activity in plasma show that the kidney plays an important role in Se homeostasis and in plasma GSH-Px synthesis.

Adult↗
PubMed2001

Parathormon, calcium, phosphorus, and left ventricular structure and function in normotensive hemodialysis patients.

Clinical and experimental data suggest that Parathormon (PTH), calcium, and phosphorus participate in left ventricular hypertrophy (LVH) and affect myocardial contractility in end-stage renal disease. Cellular calcium overload and interstitial fibrosis induced by PTH may lead to impairment of left ventricular diastolic function. Hyperphosphatemia is an independent risk of cardiovascular mortality in dialysis patients. The aim of the study was to estimate the influence of PTH and calcium-phosphorus metabolism on left ventricular structure and function in hemodialysis patients, without hypertension and antihypertensive drug therapy (SBP = 126.2 +/- 11.1 DBP = 75.8 +/- 6.5 mmHg). Echocardiographic findings in a group of 22 normotensive HD patients had been compared to 43 hypertensive HD patients. Relationships between PTH, calcium-phosphorus metabolism and echocardiography in normotensive group were then evaluated. Left ventricular mass index (LVMI) was lower in normotensive patients: 128.3 +/- 46.2 versus 165.8 +/- 46.7 (p < 0.01). The prevalence of LVH was 55% in normotensive HD patients compared to 86% in hypertensive group (p < 0.01). In normotensive group we found correlation between PTH and LVMI (r = 0.44; p < 0.05). There were also significant relationships between calcium and posterior wall thickness (r = -0.44; p < 0.05), phosphorus and LVMI (r = 0.47; p < 0.05). A significant correlation was observed between both phosphorus, calcium x phosphorus product and E/A ratio: r = -0.47 and r = -0.43, respectively (p < 0.05 both). Disturbances of calcium-phosphorus metabolism and secondary hyperparathyroidism contributes to left ventricular hypertrophy, and impaired left ventricular diastolic function in normotensive hemodialysis patients.

Antihypertensive Agents↗
PubMed2000

[Cyclophosphamide pulse therapy in patients with primary glomerulonephritis].

UNLABELLED: Cyclophosphamide is a cytostatic drug, widely used in therapy of secondary glomerulonephritis. Because pulse therapy bears less side effects than oral one we aimed to follow the cyclophosphamide effect on the course of patients with primary glomerulonephritis. We observed 20 pts (7 women and 13 men), mean age 33 +/- 10.0 yrs, age range 18-50 yrs with primary glomerulonephritis and proteinuria more than 3.5 g. 12 patients also had erythro-cyturia. In all pts kidney biopsy was performed, but in one woman the biopsy was not diagnostic. Renal biopsy revealed: FSG in 2 pts, membranous glomerulonephritis in 2 pts, in 9 pts mesangial proliferative changes and in 6--mesangiocapillary lesions. In 5 pts renal failure was observed. Cyclophosphamide was administered i.v. in the dose 0.75 g/m2 b.s., no more than 1.0 g per dose, in renal failure 0.5 g/m2. During the first six months patients received cyclophosphamide every month and then every three months. Before cyclophosphamide pulse therapy all patients were pretreated with steroids, 3 pulses of 1.0 g Methylprednisolone and then oral prednisone in the dose 20 mg/m2 body surface. RESULTS: In 3 patients we obtained remission of proteinuria, in 11 patients decrease of proteinuria but 6 patients didn't answer to the introduced treatment. In whole group of examined patients we obtained the statistically significant decrease of proteinuria from 12.2 +/- 10.5 to 5.3 +/- 5.2 g (p < 0.05) after the treatment. The creatinine clearance did not change in the time of the treatment and any special complications during the treatment were observed. We suggest that cyclophosphamide pulse therapy could be an effective treatment in pts with primary glomerulonephritis. Our results showed that the answer of proposed treatment was independent of the type to the changes found in kidney biopsy.

Adult↗
PubMed2000

[Does any relationship exist between metabolic disturbances and some markers of renal damage in patients with untreated essential hypertension?].

The essential arterial hypertension is the second (after diabetes mellitus) cause of chronic renal failure which means a great social and economic burden to the society. It is well known that hypertension is a metabolic syndrome resulting in tissue injury. We tried to investigate the possible influence of some metabolic disturbances on renal function in nontreated essential hypertension. We have compared 25 patients with nontreated essential hypertension (11 women, 14 men) with 14 healthy volunteers (7 women, 7 men) matched for age. The patients' group was characterized by significantly higher urine excretion of NAG (N-acetyl-beta-D-glucosaminidase) (2.75 +/- 1.69 vs 1.82 +/- 1.46 p < 0.05) and a tendency to significantly higher urine fractional sodium excretion without significant difference in albumin excretion. These findings suggest that the tubular damage is present. We noticed the negative linear correlation between mean arterial pressure and (MAP) and NAG urine excretion in the group of hypertensive patients which may reflect the renal ischemia in tubulo-interstitial pathology. Our data suggests that in nontreated arterial hypertension the renal blood flow disturbances are the important cause of the deterioration of tubular function (which are earlier to glomerular damage).

Acetylglucosaminidase↗
PubMed1999

The effect of nitrendipine on renal haemodynamics and tubular reabsorption and its neural control in anaesthetised rats with chronic renal failure.

This study examined the influence of a calcium channel antagonist, nitrendipine, on blood pressure and kidney function in a rat model of chronic renal failure. Additionally, the effects of low frequency renal nerve stimulation were studied in the presence and absence of nitrendipine. Male Wistar rats were fed a diet high in adenine for 4 weeks and then acutely anaesthetised and prepared for renal functional measurements. Blood pressure was elevated but renal blood flow and glomerular filtration rate were reduced, between 30 to 50%, urine flow and absolute sodium excretion were lower and fractional sodium excretion was two to three times higher than in normal rats. Nitrendipine (0.25 microg/kg/min i.v.) decreased blood pressure at 114+/-7 mm Hg, by 11% (P<0.05), increased left renal blood flow, at 1.3+/-0.2 ml/min(-1) g(-1), by 16% (P<0.01), and urine flow, absolute and fractional sodium excretions, by between 50-83% (all P<0.05). Renal nerves stimulation (0.7-1.3 Hz, 15V, 0.2 ms) decreased (P<0.02) left renal blood flow by 10% but had no effect on excretory variables, irrespective of nitrendipine administration. These results show that in renal failure rats the vascular and tubular responses to nitrendipine are preserved. However, the neural regulation of tubular reabsorption is abolished in this experimental model, irrespective of nitrendipine administration.

Anesthesia↗
PubMed1997

The effect of dietary enrichment with fish-oil on urinary excretion of N-acetyl-beta-D-glucosaminidase and renal function in proteinuric patients with primary glomerulopathies.

The rate of progression of renal disease depends on many factors including serum lipids and tubulo-interstitial injury. Aim of the study was to see whether fish-oil therapy may affect serum lipids and NAG excretion with urine (a marker of tubular cell damage) in humans with renal disease. The effects of dietary fish-oil fatty acids on the serum lipids, NAG urinary excretion and serum arachidonic acid concentration were examined in thirteen primary glomerulonephritic patients with proteinuria and normal renal function. The regular diet enriched with 1650 mg n-3 polyunsaturated fatty acids (18%: 20:5; n-3 EPA and 12%: 22:5; n-3 DHA) was ingested for three months. At the end of fish-oil enriched diet neither creatinine clearance nor urinary protein excretion changed significantly. But serum concentration of HDL and arachidonic acid increased (48.0 +/- 15 vs. 52.0 +/- 14; p < 0.05), (0.47 +/- 0.13 vs. 0.72 +/- 0.29; p < 0.01), respectively. Simultaneously urine NAG excretion and serum LDL decreased (11.2 +/- 7.1 vs. 10.3 +/- 7.3; p < 0.05), (163.0 +/- 57 vs. 149.0 +/- 51, p < 0.01), respectively. We presume that fish-oil supplementation may have a beneficial effect on renal tubular cells in humans and it could be linked with arachidonic acid metabolism.

Acetylglucosaminidase↗
PubMed1997

[The levels of adenine nucleotides and hypoxanthine in blood of patients on long-term hemodialysis using dialysis fluid containing acetate or bicarbonate].

Intraerythrocyte adenine nucleotides concentration reflects energy balance of red cells and plays pivotal role in their function. In hemodialysed patients both ATP and ADP concentration in red cells was higher than in controls, p < 0.001 and p < 0.005 respectively. But AMP and hypoxanthine did not differ from control. No change of ATP, ADP and AMP was observed after hemodialysis, but hypoxanthine fall significantly, p < 0.001. The pattern of nucleotides concentration and its changes during hemodialysis was the same regardless of the mode of the therapy; e.g. acetate or bicarbonate.

Acetates↗
PubMed1997

[Evaluation of prophylaxis and actual prevalence of HBV infection in twelve hemodialysis centers of Northern Poland].

The aim of the study was to estimate the HBV infection preventive measures used in the twelve dialysis centres in north Poland. In all of the centres hepatitis B vaccination and segregation of HBV infected patients (dedicated machines or separate rooms), which are the two basic HBV infection control methods, were introduced. Our results point out that in some of the centres certain modification of these methods would be possible, including universal predialysis vaccination programme, changes in hepatitis B vaccination schedules with most effective routes of vaccination only and dedication for HBV infected patients not only separate rooms but separate dialysis staff as well.

Adolescent↗
PubMed1996

Erythrocyte nucleotides and blood hypoxanthine in patients with uremia evaluated immediately and 24 hours after hemodialysis.

Using high-performance liquid chromatography, concentrations of erythrocyte adenine nucleotides and hypoxanthine were evaluated in patients undergoing regular acetate hemodialysis before dialysis, immediately following dialysis, and 24 hr after. It was shown that adenosine triphosphate concentration was maintained consistently high, not only just after hemodialysis but also 24 hr later. There was also no difference in concentration of mono- and diphosphates of adenosine. Hypoxanthine concentration decreased twofold after hemodialysis. However, it was still markedly higher than normal values. The level of hypoxanthine was maintained at the postdialysis level, 24 hr later. This suggests that hypoxanthine production could be stimulated during acetate dialysis.

Adult↗
PubMed1996

[Prevalence of response to anti-HBV infection in patients on maintenance hemodialysis infected with hepatitis C virus (HCV)].

We have studied the antibody response to hepatitis B vaccine in 42 hemodialysis patients; 8 of them were diagnosed as having HCV infection before vaccination. Hemodialysis patients received four doses of recombinant HB vaccine (Engerix-B, SKB, 40 micrograms per dose). Seroconversion occurred in 71.4% of all hemodialysis patients; in 79.4% of HCV-negative and in 37.5% of HCV-positive patients. Effective immunity (anti-HBs titer higher than 100 m IU/ml) was observed in 12.5% of HCV positive and in 35.3% of HCV-negative patients. We conclude that HCV infection may modify or postpone the response to hepatitis B vaccine.

Adult↗