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Biomedical subjects

R Gellert

Publications and source records attributed to R Gellert.

At least 37 records · Page 2Linked to original sources
PubMed1994

[Evaluation of bone mineralization in patients on maintenance hemodialysis].

Bone loss and bone formation and mineralization abnormalities resulting from disturbances in calcium and phosphorus metabolism are frequent in chronic renal failure. Haemodialysis permits long-term survival of patients with end-stage renal disease. This is the reason, why renal osteodystrophy became an important diagnostic and therapeutical problem. Very low occurrence of fractures among haemodialysed patients in our clinic, stimulated our efforts to elucidate the causes of this phenomenon. The aim of this study was to compare bone mineral densities in haemodialysed patients and healthy volunteers. 47 patients on maintenance haemodialysis (16 F, 31 M) and 55 healthy volunteers (33 F, 22 M) with normal renal function were investigated. Endocrinopathy or any other diseases that could cause changes in bone metabolism were excluded. Age distribution in both groups was similar. Patients maintained on low sodium and phosphorus diet additionally were supplemented with large doses of calcium carbonate. Haemodialyses were performed using reverse-osmosis water. BMD (Bone Mineral Density) was measured using QCT (Quantitative Computed Tomography) and was expressed as an average hydroxyapatite content in lumbar vertebraes L1-L4. The obtained results indicate high BMD of vertebral bones in haemodialysed patients from our Dialysis Department. BMD was similar to that observed in healthy volunteers. This could at least partially explain low occurrence (2 in 142 pts-years) of fractures in ou uraemic patients. However we were unable to point exactly the simple factor responsible for this positive phenomenon. We hope that introduction of our haemodialysis scheme can help patients to avoid renal osteodystrophy.

Adult↗
PubMed1994

[Antithrombotic activity of low molecular weight heparin (enoxaparin) during hemodialysis in patients with terminal kidney failure].

The aim of the study was to evaluate the efficacy of low molecular weight heparine (enoxaparin) in comparison to heparin during haemodialysis (HD) in prevention of blood clotting chestry extracorporeal circulation. Enoxaparin (Clexan, Rhone-Poulenc Rorer, in syringes, 20 mg) was evaluated in 42 patients with end stage renal failure treated with HD. In the first part of study heparine and in the second part enoxaparin given into arterial lines were evaluated during 6 following HD with the same type of dialysator. Clotting of extracorporeal circulation and bleeding time from the needle site after HD were evaluated. Activated partial thromboplastin time (APTT) before, after 1 hour of HD and after HD during heparine and enoxaparin were measured. There was advantage of enoxaparin in 23 patients when compared to heparine. It was depended on the reduction of number of injections of enoxaparin when compared to heparine (22 patients have received heparine in 2 or more doses when only 5 patients have received enoxaparin in 2 doses) on the reduction of clotting events in extracorporeal circulation (16 events during heparine treatment -6.3% of all HD and 5 events during enoxaparin treatment -2.0% of all HD), and on the shortening of the bleeding time from the needle site after HD (5.9 +/- 3.4 min. during heparin and 4.5 +/- 1.6 min. during enoxaparin treatment; p < 0.02). Increase of APTT after 1 hour of HD when compared to the value from before HD was significantly lower during enoxaparin than heparine therapy (1.73 +/- 0.4 and 2.55 +/- 0.91 respectively; p < 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1993

Efficiency of hemodialysis of pyrimidine compounds in patients with chronic renal failure.

The accumulation in blood plasma and efficiency of hemodialysis of pyrimidine compounds (orotic acid, orotidine, pseudouridine, uridine, thymine) as well as uric acid and creatinine in 23 patients with chronic renal failure (CRF) was investigated. As a reference, the analysis of the above metabolites in the plasma of 30 healthy volunteers was performed. Among examined compounds, pseudouridine possessed the highest capability of accumulation in blood plasma (25 times higher concentration than physiological). It coincided with the lowest efficiency of pseudouridine hemodialysis (44%) and the longest T1/2 (relative to creatinine) in plasma. A significant linear correlation (r = 0.81, p < 0.001) between efficiency of creatinine and pseudouridine hemodialysis was calculated. The concentration of orotic acid in the blood plasma of patients before hemodialysis exceeded 14 times its level in healthy subjects; the inhibition of uric acid synthesis by allopurinol in dialyzed patients was accompanied by enlargement of orotidine and orotate accumulation in blood plasma. Extremely high plasma concentration of examined pyrimidines remaining elevated after hemodialysis creates an additional hazard for tissue metabolism and health of patients with CRF.

Adult↗
PubMed1993

[Renal biopsy in the aged].

Pathological findings in urinalysis in the aged persons are usually thought to be caused by pathologic processes other than glomerulopathy. Histological evaluation of renal tissue in older patients is extremely difficult due to coexistence of involuntary changes-hyalinosis, increase in mesangial matrix content, and vascular changes. The aim of the study was to evaluate frequency of glomerulonephritis, both primary and secondary in persons older than 60. In this group, as compared to the younger people the secondary glomerulonephritis was more frequent, amyloidosis and vasculitis nodosa being the most frequent. In primary glomerulonephritis mesangiocapillary type dominate, quite often some tendency to hyalinization could be observed. Renal biopsy is useful as a diagnostic tool in both the aged and young. It should be performed regardless the patients age.

Adult↗
PubMed1991

Intradialytic erythrocyte volume changes.

Haemodialysis (HD) should affect the erythrocytes, which constitute more than 99% of blood cells. The aim of this study was to reinvestigate the intradialytic changes in erythrocyte water content (MCV). MCV was measured during 81 HD (47 uncomplicated, 34 with hypotension), and 16 isolated ultrafiltrations (UF) performed in stable, haemodialysed adults (12 males and 8 females). The MCV following uncomplicated HD (n = 32) did not differ from the predialysis value. Significant MCV increase accompanied the HD initiation (4.9 +/- 9.0 fl, P less than 0.001), UF (2.99 +/- 1.49 fl, P less than 0.001) and hypotension (1.8 +/- 3.1 fl, P less than 0.01). This was independent of sodium and potassium within the cells and plasma. Erythrocyte oedema occurred in situations known to accompany both bioincompatibility reactions and blood volume decrease. Intradialytic MCV increase may reflect a response to these events, possibly hormonal, and needs further investigation.

Adult↗
PubMed1991

[Many-year observations of 4 cases of Wegener's granulomatosis].

Four cases of Wegener's granulomatosis were presented. Pathologic lesions and symptoms were observed in numerous organs but in all patients upper airways, lungs and kidneys were involved. Patients were observed from 3 to 12 years and two patients are still alive after more than 10.5 years.

Adolescent↗
PubMed1991

[Wegener's granulomatosis--evaluation of diagnostic problems and the progress in its treatment based on the review of 54 cases published in Poland in 1959-1990].

54 cases of Wegener's granulomatosis published in Polish literature in 1959-1990 are presented. There were 37 women and 17 men from 17 to 70 years of age. The diagnosis was histologically proved during life in 30 cases and by autopsy in 14 others. In 10 patients it was based on clinical symptoms only. Diagnosis was established after 1 months to 4 years of symptoms, mean equals 10.3 months. The delay of diagnosis was caused by the ineffectiveness of biopsy, usually from the upper airways and also by the wrong interpretation of histopathological pictures. All patients had upper airways disease, 56% of patients had lung involvement, 66% renal lesions, 37%--eye changes, 35% skin lesions and 11%--nervous system involvement. In addition in 83% of patients systemic symptoms were observed. The prognosis of WG ameliorate with the time of publications due to cyclophosphamide and other cytotoxic drugs introduction to WG treatment.

Adolescent↗
PubMed1990

[Diagnostic value of the lupus band test in patients treated by chronic hemodialysis].

The diagnosis of systemic lupus erythematosus in cases with advanced renal failure is a serious clinical problem. The purpose of the study was an analysis of the incidence of various non-renal criteria (according to ARA) for the diagnosis of SLE in patients with chronic renal failure of various aetiology and find out whether the lupus band test in these patients may serve as an additional criterion for the diagnosis of SLE. The studied group comprised 39 patients with chronic renal failure (28 men and 13 women) aged 17-58 years. In this group 29 cases were treated with dialyses and 10 conservatively. The most frequent clinical sign (apart from renal changes) accepted as diagnostic criteria for the SLE was polyserositis and leucopenia and thrombocytopenia. In no case antinuclear antibodies, antibodies against DNA and against soluble nuclear antigens were found. Positive LBT was obtained in 72.4% of cases with chronic renal failure, particularly frequently in the dialysed patients. A positive result of the LBT cannot be of decisive importance in the diagnosis of SLE but may suggest a need of more detailed investigations (determination of Ro antibodies) for confirmation of the diagnosis.

Adolescent↗
PubMed1981

Denervated and intact kidney responses to exercise in the dog.

In conscious female dogs exercise-induced changes in the function of the innervated and denervated kidney were studied by clearance techniques. The animals were prepared for experiments by chronic unilateral renal denervation and surgical division of the urinary bladder to enable separate urine collection from each kidney. A 20-min run on a treadmill at a speed of 2.6 m/s significantly decreased urine flow, osmolar clearance, sodium excretion, as well as clearances of exogenous creatinine and p-aminohippurate in the denervated kidney only. In dogs running at 3.6 m/s renal hemodynamics decreased significantly and similarly for both kidneys, whereas the fall in renal excretion was virtually limited to the denervated kidney. As glomerular filtration rate (GFR) was falling during exercise, sodium excretion per 100 ml GFR tended to increase in the innervated kidney, in contrast to an expected slight fall on the denervated side. This indicated a defect of tubular sodium reabsorption of the innervated kidney. On the whole, the data do not support an important mediatory role of renal nerves in the mechanism of renal function changes during exercise.

Animals↗
PubMed1980

Influence of renal denervation on urine concentration in awake and anaesthetized dogs.

The role of renal nerves in urine concentration was studied in clearance experiments with unilaterally renal-denervated dogs prepared by surgical bladder division. Urine concentration was assessed under conditions of: (1) stimulation of ADH release by dehydration or barbiturate anaesthesia; (2) mannitol diuresis, and (3) isotonic saline diuresis. Differences in TcH2O/GFR between the intact and denervated kidney were not significant in any of the experimental groups. However, in dehydrated conscious dogs Uosm of the intact kidney (939 +/- 58 mmol/kg H2O) was significantly higher (P less than 0.05) than that of the denervated organ (806 +/- 51 mmol/kg H2O). In the intact kidney the medullary content of total solutes and sodium per kg wet tissue was 684 +/- 26 mmol and 208 +/- 12 mmol, respectively. This was significantly higher (P less than 0.005) than corresponding values of 581 +/- 23 mmol and 171 +/- 14 mmol per kg wet tissue measured in the denervated organ. We suggest that a slight impairment of urine concentration (lower Uosm) in the denervated kidney of conscious dogs may depend on decreased medullary hypertonicity.

Anesthesia↗
PubMed1979

Denervated and intact kidney responses to saline load in awake and anesthetized dogs.

The function of the innervated and denervated kidney was examined in clearance studies with unilaterally renal-denervated conscious and anesthetized dogs before and after saline loading. Barbiturate anesthesia distinctly depressed hemodynamics and excretory function of both kidneys and increased the difference between the denervated and innervated organ. In conscious moderately hydrated dogs the denervated kidney excreted slightly more sodium and water, while after saline loading higher excretion was observed on the innervated side. The denervated-to-innervated kidney ratios for UNaV, UNaV/100 ml GFR, and urine flow fell significantly from mean control values of 1.27, 1.27, and 1.20, respectively, to 0.80, 0.87, and 0.77 after extracellular volume expansion. Similar alterations of the ratios were observed in anesthetized dogs, but higher excretion of the denervated kidney persisted after saline loading. It is concluded that the greater natriuretic response of the intact kidney to saline infusion was due to inhibition of sodium-retaining action of renal efferent nerve activity by acute extracellular volume expansion.

Animals↗
PubMed1979

Reinvestigation of denervation diuresis and natriuresis in conscious dogs.

The function of innervated and denervated kidney was compared in clearance studies with conscious dogs. The animals were prepared for experiments by unilateral renal denervation and surgical division of the bladder to form two hemibladders enabling separate urine collection from two kidneys. The mean urine flow was 6% higher for the denervated kidney (not significant) while mean differences for osmolar clearance (+ 13%), sodium excretion (+21%) and GFT (+5%) were all significant (P less than 0.05). When corrected to 100 ml GFR, sodium excretion was not significantly higher for the denervated kidney. In most experiments higher sodium excretion on the denefvated side was associated with higher GFR. Thus, contrary to some earlier views, a slight increase in the excretory function which follows denervation of the kidney is demonstrable also in conscious undisturbed animals. The data suggest that increased haemodynamics of the denervated kidney are responsible for higher excretion, but do not exclude a contribution of inhibited tubular reabsorption.

Animals↗