1,720,981 research outputs found
Tuberculous meningitis in a renal transplant recipient
No full textTuberculous meningitis is a very rare, but serious extrapulmonary complication of mycobacterial infections in immunocompromised patients, such as organ transplant recipients. We describe here a 66-year-old Turkish woman without any history of tuberculosis, who received a renal allograft transplant in 1994. After a pilgrimage to an endemic area for tuberculosis, she presented with fever and headache in August 1998. Clinical examination revealed positive meningism and hyperreflexia. Lymphocytosis was noted in her cerebrospinal fluid (CSF) and Mycobacterium tuberculosis infection was detected by PCR within the CSF. Despite immediate triple antituberculosis therapy, the patient's clinical condition deteriorated rapidly, with the development of septic shock syndrome, and she died three weeks after admission due to cardiovascular and respiratory failure. Mycobacterial infections, including extrapulmonary manifestations, should thus be considered in all renal transplant recipients presenting with unexplained fever. Preventive therapy, i.e. isoniazid prophylaxis, may also be recommended for patients risking exposure in areas endemic for tuberculosis
Tuberculous meningitis in a renal transplant recipient
No full textTuberculous meningitis is a very rare, but serious extrapulmonary complication of mycobacterial infections in immunocompromised patients, such as organ transplant recipients. We describe here a 66-year-old Turkish woman without any history of tuberculosis, who received a renal allograft transplant in 1994. After a pilgrimage to an endemic area for tuberculosis, she presented with fever and headache in August 1998. Clinical examination revealed positive meningism and hyperreflexia. Lymphocytosis was noted in her cerebrospinal fluid (CSF) and Mycobacterium tuberculosis infection was detected by PCR within the CSF. Despite immediate triple antituberculosis therapy, the patient's clinical condition deteriorated rapidly, with the development of septic shock syndrome, and she died three weeks after admission due to cardiovascular and respiratory failure. Mycobacterial infections, including extrapulmonary manifestations, should thus be considered in all renal transplant recipients presenting with unexplained fever. Preventive therapy, i.e. isoniazid prophylaxis, may also be recommended for patients risking exposure in areas endemic for tuberculosis
Characterization of aldose reductase from the thick ascending limb of henle's loop of rabbit kidney
No full textBackground: The organic osmolyte sorbitol plays an important role in the osmoregulation of immortalized epithelial cells of the thick ascending limb of Henle's loop (TALH) of rabbit. The intracellular sorbitol content seems to depend strongly on the extracellular osmolarity. To investigate the nature of the osmotic regulation we characterized the aldose reductase. Methods: We determined aldose reductase activity enzymatically and the content of organic osmolytes by HPLC. Results: The aldose reductase activity correlates with the extracellular tonicity. Elevating the osmolarity of the medium from 300 to 600 mosm/l by addition of NaCl or sucrose resulted in a significant increase of maximal velocity (V-max) of the adapted cells from 8 +/- 1 mu mol/g x min (300 mosm/l) to 322 +/- 28 mu mol/g x min (600 mosm/l, NaCl) or 54 +/- 9 mu mol/g x min (600 mosm/l, sucrose), respectively, while affinity (K-m) remained unchanged. But we found no rise of aldose reductase activity when extracellular urea concentration was elevated. Similar alterations in V-max were observed when the activity of the highly enriched enzyme was determined with glucose as substrate. Elevation of the extracellular osmolarity by NaCl and sucrose strongly induced the expression of aldose reductase protein with an apparent molecular weight of 39 kD. The affinity of glucose is characteristically low with a K-m above 300 mmol/l. Aldose reductase utilizes both NADPH and with lower affinity NADH as coenzymes. In vitro sulfate ions (0.4 mol/l) results in a two-fold activation of the aldose reductase activity whereas sodium (200-400 mmol/l) decreased the activity significantly (22-33%). Potassium and chloride up to 400 mmol/l did not alter the aldose reductase activity in vitro. Conclusions: These results indicate that the aldose reductase of TALH cells of the outer medulla is osmotically regulated and has many similarities with aldose reductase in renal inner medulla. Therefore, intracellular sorbitol synthesis seems to be of similar importance in the osmoregulation of TALH cells as in the inner medulla. Copyright (C) 2001 S. Karger AG, Basel
Immunocytological determination of lymphocytes and monocytes/macrophages in urinary sediments of renal allograft recipients
No full textBackground. Urinary studies using Papanicolaou staining following kidney transplantation led to the conjecture that acute allograft rejection might be accompanied by an increased lymphocyturia. However, it is difficult to distinguish lymphoid cells from other urinary cells using conventional stains. Methods. Staining of urinary lymphocytes using FITC-labelled antibodies is complicated by a high unspecific fluorescence that limits the evaluation. Therefore, we developed a method to stain urinary lymphocytes using enzyme-linked antibodies. The cells were cytocentrifuged onto microscope slides and were fixed. Results. By means of a combined evaluation of Papanicolaou and immunocytochemical staining, CD3-positive pan T cells, CD4-positive T-helper cells, CD8-positive cytotoxic/suppressor cells, and CD14-positive monocytes/macrophages of urinary sediments were determined in 41 kidney graft recipients following renal transplantation. During periods of normal graft function, neither positive lymphocytes nor positive monocytes/macrophages were found in the urinary sediments. However, in the course of acute allograft rejection a significant increase in positive lymphocytes and positive monocytes/macrophages could be observed. Interestingly, in cases of acute allograft rejection the distribution of urinary lymphocytes and monocytes was comparable to the distribution of infiltrating immunocompetent cells in renal allograft biopsies. Conclusion. The present study demonstrates that immunocytochemical staining via enzyme-conjugated antibodies is a reliable method to visualize T lymphocytes and monocytes/macrophages in the urinary sediment, and that this technique may be of special diagnostic value in the diagnosis of acute allograft rejection
Osmoregulation of aldose reductase and sorbitol dehydrogenase in cultivated interstitial cells of rat renal inner medulla
No full textBackground. Little is known about sorbitol metabolism in renal papillary interstitial cells. For characterization we studied regulation of sorbitol synthesis by aldose reductase (AR) and degradation by sorbitol dehydrogenase (SDH) in papillary interstitial cells. Methods. Interstitial cells were isolated from rat renal inner medulla to a pure cell fraction. mRNA was isolated from cultivated cells and sorbitol, AR and SDH activity were determined enzymatically in homogenates. Results. Sorbitol concentration in these cells at 300 mosmol/l was 4.4 +/- 0.3 vs 78 +/- 3.6 mumol/g protein at 600 mosmol/l. At steady-state conditions at 300 mosmol/l, AR activity was nearly the same as SDH activity (15.1 +/- 1.6 vs 16.6 +/- 2.0 U/g protein). At 600 mosmol/l, AR activity increased to 82.5 +/- 11.4 U/g protein and SDH activity to 31.5 +/- 6.0 U/g protein. Studying the time course of enzyme activity after changing osmolarity from 300 to 600 mosmol/l, we found half maximal stimulation after 2-3 (AR) or 3 (SDH) days. The amount of AR-mRNA preceded the rise of enzyme activity, whereas SDH-mRNA was not significantly influenced. Lowering osmolarity from 600 to 300 mosmol/l, enzyme activity decreased to less than half within 2 (AR) or I (SDH) day(s). Conclusions. The results suggest that sorbitol metabolism contributes to handling of osmotic stress in rat renal papillary interstitial cells
Differential effects of theophylline on sympathetic excitation, hemodynamics, and breathing in congestive heart failure
No full textBackground-Patients with heart failure have high levels of central sympathetic outflow and also have a high prevalence of sleep-related breathing disorders, predominantly central sleep apnea. The options for treating central sleep apnea in heart failure are limited and include theophylline. Whether theophylline alters sympathetic activity in heart failure patients is not known. Methods and Results-Using a single-blinded, randomized, placebo-controlled study design, we investigated the sympathetic, hemodynamic, neurohumoral, and ventilatory effects of theophylline in patients with congestive heart failure compared with healthy control subjects closely matched for age, sex, and body mass index. Theophylline increased muscle sympathetic nerve activity and lowered transcutaneous CO2 in the control subjects but only lowered transcutaneous CO2 in the heart failure patients. Theophylline nearly doubled plasma renin concentration in both the healthy subjects (P < 0.01) and the heart failure patients (P < 0.02). Conclusions-Our study shows that in heart failure patients, there are differential effects of theophylline: in contrast to healthy subjects, theophylline does not increase sympathetic activity in heart failure, whereas increases in plasma renin and ventilation are still evident. These novel findings may have important implications for understanding the potential harmful and beneficial effects of theophylline and related substances in heart failure patients
First steps toward the establishment of a German low-density lipoprotein-apheresis registry: Recommendations for the indication and for quality management
No full textNew recommendations for the indication of treatment with selective extracorporeal plasma therapy low-density lipoprotein apheresis (LDL-apheresis) in the prevention of coronary heart disease are urgently needed. The following points are the first results of the ongoing discussion process for indications for LDL-apheresis in Germany: all patients with homozygous familial hypercholesterolemia with functional or genetically determined lack or dysfunction of LDL receptors and plasma LDL cholesterol levels >13.0 mmol/L (>500 mg/dL); patients with coronary heart disease (CHD) documented by clinical symptoms and imaging procedures in which over a period of at least 3 months the plasma LDL cholesterol levels cannot be lowered below 3.3 mmol/L (130 mg/dL) by a generally accepted, maximal drug-induced and documented therapy in combination with a cholesterol-lowering diet; and patients with progression of their CHD documented by clinical symptoms and imaging procedures and repeated plasma Lp(a) levels >60 mg/dL, even if the plasma LDL cholesterol levels are lower than 3.3 mmol/L (130 mg/dL). Respective goals for LDL cholesterol concentrations for high-risk patients have been recently defined by various international societies. To safely put into practice the recommendations for LDL-apheresis previously mentioned, standardized treatment guidelines for LDL-apheresis need to be established in Germany that should be supervised by an appropriate registry
Cisplatin nephrotoxicity in children after continuous 72-h and 3x1-h infusions
No full textLittle is known about the association between the rate of cisplatin administration and the severity of cisplatin-induced renal damage in children. The purpose of this study was to compare severity and reversibility of renal damage in children after continuous and repetitive bolus administration of cisplatin and to correlate these data with pharmacokinetic parameters. Study subjects included six children (ten courses) receiving cisplatin as 1-h bolus infusions on three consecutive days (3x40 mg/m(2)) and four children (eight courses) receiving 72-h continuous infusions (120 mg/m(2)). In all courses, signs of glomerular and tubular damage were seen,as evidenced by elevated urinary excretion of alpha (1)-microglobulin, albumin and N-acetyl-beta -D-glucosa-minidase and decreased glomerular filtration rate (GFR). Comparing the two infusion regimens, the 1-h bolus administration of cisplatin was followed by significantly higher peak free platinum concentrations in plasma and urine (P <0.001), resulting in lower nadirs: of the GFR (P <0.005). Correlations were found between both peak free platinum concentrations in plasma and urine and maxima of urinary albumin and N-acetyl-beta -D-glucosaminidase excretion. Within 12 months after completion of cisplatin therapy, children in the 1-h bolus group had recovered only partially from subclinical nephrotoxicity, with five out of six showing pathological proteinuria. The results provide clear evidence that long-term ciplatin infusions are less nephrotoxic than repetitive bolus infusions
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