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Biomedical subjects

W Pfaller

Publications and source records attributed to W Pfaller.

At least 55 records · Page 3Linked to original sources
PubMed1988

Comparison of serum neopterin levels and urinary neopterin excretion in renal allograft recipients.

Determination of serum and urinary neopterin levels was performed daily in 30 patients undergoing kidney transplantation for treatment of end-stage renal failure. Neopterin serum levels were determined by RIA and urinary excretion by HPLC. In parallel, the same samples were tested for creatinine content. Results indicated a strong correlation between the clearance of neopterin and creatinine. This correlation was independent of the extent of functional impairment as well as of the different causes of renal insufficiency. As a consequence, a strong relationship between serum and urinary neopterin levels was only obtained when values were corrected for different renal function by dividing them by the creatinine levels. It thus appears that major attention has to be paid to the functional state of the kidney when studying neopterin serum and/or urine values. It also appears that under these prerequisites both methods of detection as well as both sample sources yield comparable results.

Adult↗
PubMed1987

Local injection of cysteamine into the rat striatum decreases number and intensity of staining of neurons by indirect NADPH diaphorase reaction.

Cysteamine (100 micrograms) markedly reduces the number (by about 60%) and intensity of staining of NADPH diaphorase-reactive neurons 6 h after local injection into the striatum. This effect was reversible (after 24 h) and was only observed when the indirect staining procedure was applied in which NADPH formed by endogenous malate dehydrogenase is used. However, no direct effect of cysteamine on the malate dehydrogenase reaction was found. The decrease in NADPH diaphorase activity parallels the previously reported cysteamine induced decrease in somatostatin contained in the same neurons and may point to a biochemical interrelation of somatostatin and NADPH diaphorase in these neurons.

Animals↗
PubMed1986

Urinary enzyme analysis in renal allograft transplantation.

The urinary excretion of four enzymes (fructose-1,6-bisphosphatase, glutathione S-transferase, N-acetyl-beta-D-glucosaminidase and pyruvate kinase) was assayed daily in 59 patients following renal cadaveric allografting. 51 patients were given cyclosporin A (CyA group) as an immunosuppressive, 8 patients were treated conventionally with azathioprine and prednisolone (CON-group). Urinary enzyme output was evaluated by two different mathematical models. Model A follows single enzyme excretion, whereas model B also analyzes enzyme patterns. The best results were obtained by a combined analysis of all four enzymes with model B. In the CON-group the sensitivity was 1.00, the specificity 0.85, the predictive values of positive test 0.45 and all 12 graft rejections were diagnosed correctly. In the CyA group the sensitivity was 0.40, the specificity 0.99, the predictive value of positive test 0.33, and 6 out of 9 rejections were recognized. The evaluation of the single enzymes did not produce similarly good results with either model.

Acetylglucosaminidase↗
PubMed1986

Macrophage infiltration in non-Hodgkin's lymphomas: a quantitative in situ study.

The frequency and distribution pattern of macrophages within 93 non-Hodgkin's lymphomas (NHL) were evaluated in situ by immunomorphometry using stereological methods. For the identification of macrophages (M phi), several antibodies (Mono 1, Mono 2, OKM 1) reactive with surface antigens on cells of the monocyte-macrophage series and cytochemical staining for acid phosphatase were applied. The average number of macrophages within lymph node tissue of NHL was 6,299 +/- 760 cells/microliter (similar to reactive lymphatic tissue: 6,559 +/- 1,027). The highest number of infiltrating macrophages was detected in immunoblastic NHL (17,306 +/- 2,773), differing significantly from other histological subtypes and reactive lymphatic tissue (p less than 0.005). The possible impact of tumor-infiltrating macrophages on lymphoma cell proliferation and differentiation is discussed.

Antibodies, Monoclonal↗
PubMed1986

Morphological and biochemical observations in rat nephron epithelia following cyclosporine A (CsA) treatment.

Morphology, urinary enzyme excretion and mitochondrial function was studied in rats fed over a period of 30 days with 20 and 40 mg CsA/kg body weight. Already on day 8 vacuolisation and augmentation of autophagic vacuoles, lipid droplets and a loss in microvilli can be observed in the S-3 segment of the proximal nephron using the lower CsA dose. These effects are enhanced during the treatment period. The overall effect, however, is a subtle one. The dose of 40 mg/kg produces more pronounced cellular alterations, a more severe vacuolisation, but also focal prenecrotic damage of proximal tubular S-2 and S-3 cells. The cells altered in that manner amount to roughly 5% of the total proximal tubular epithelium. Enhanced urinary excretion of the proximal cytosolic enzymes, fructose-1,6-bisphosphatase, glutathione S-transferase, pyruvate kinase and the lysosomal N-acetyl-beta-D-glucosaminidase appear to parallel the morphologic changes, whereby only the excretion of pyruvate kinase is significantly elevated on day 30 using 40 mg/kg. Decrease in oxidative phosphorilation capacity (ADP:O ratio) was found with both CsA doses, however, this result seems to be dissociated from changes in morphology and enzyme excretion. Studies on isolated tubular fragments in vitro, exposed to CsA exhibited an inhibition of the cytosolic malate dehydrogenase isoenzyme, which could be interpreted as a possible source of the CsA induced tubular alteration.

Acetylglucosaminidase↗
PubMed1985

[Infiltration pattern of immunocompetent lymphocytes in the tissue of malignant non-Hodgkin's lymphoma: relationship to histological and clinical parameters].

The number and distribution of reactive cells in more than 100 non-Hodgkin lymphomas (NHL) were evaluated in situ in cryostat sections. The results were compared with histological and clinical findings. 40% of the T cell content of normal lymphatic tissues was found in tissues of B-cell NHL. This corresponds to a mean of 2 X 10(4) reactive T-cells/microliter tumour tissue. The numerical density of natural killer (NK) cells within tumours was similar to that of normal lymphatic tissues (0.5 X 10(4) cells/microliter). The distribution of the reactive cells within the tumours was diffuse except in the case of centroblastic/centrocytic lymphomas. On evaluation of the different histological entities a significant correlation was obtained between number of helper/inducer (TH) cells, TH:T-suppressor (Ts) ratio and prognostically favourable histological subgroups. Furthermore, independent of histological criteria, a close correlation was found between a high number of TH-cells, a high TH:Ts ratio and a favourable clinical course (p less than 0.04). NK-cell infiltration was present to a markedly higher extent in tissues of patients with generalized disease as compared with localized disease (p less than 0.03). Low-grade malignant NHL contained significantly more NK cells than high-grade malignant NHL, as was the case also in treated, as opposed to untreated patients. These findings together suggest that reactive cells influence tumour growth via local interactions. However, tissue distribution and infiltration density of T-cell subpopulations and NK cells were clearly different. Thus, in tumour tissues different and independent immunoregulatory mechanisms seem to be associated with these two lymphocyte subsets.

Antibodies, Monoclonal↗
PubMed1985

[Host reaction in non-Hodgkin's lymphomas: tumor infiltration with monocytes/macrophages].

The number and distribution of macrophages in deep frozen sections of various non-Hodgkin lymphomas (NHL) were evaluated in situ by immunomorphometry using stereological methods. The density of infiltration was correlated with clinical parameters. Several monoclonal antibodies reactive with antigens present on cells of the monocyte-macrophage series were tested in parallel. The density of macrophages within NHL of high malignancy with 11.3 X 10(3) +/- 1739 positive cells/microliter tumour tissue was higher than in those of low malignancy (4.7 X 10(3) +/- 628). The highest value of positive cells was found in immunoblastic lymphoma (17.3 X 10(3) +/- 2773), differing significantly from other histological subtypes of NHL and normal tissue (normal tissue: 6.5 X 10(3) +/- 1027, p less than 0.005). With regard to clinical parameters, localized NHL displayed lower infiltration numbers than generalized NHL. Possible mechanisms of influencing tumour growth are discussed in view of the large infiltration density of the monocyte macrophage series in NHL of unfavourable histology and advanced clinical stage.

Antibodies, Monoclonal↗
PubMed1985

Infiltration density of HNK 1 positive cells in non-Hodgkin's lymphomas depends on histologic subtype: an in situ morphometric analysis.

Numbers and distribution of HNK-1 (Leu 7) positive cells within 115 malignant Non-Hodgkin's lymphomas (NHL) were evaluated in situ by immunomorphometry. Results on the infiltration were related to histological and clinical parameters. A mean of 4.099 +/- 350 HNK 1+ cells/microliter tumor tissue was found, which was comparable to normal (reactive) lymphatic tissues (4.441 +/- 1.235) and was about a quarter of the population density of T helper/inducer (TH) and T cytotoxic/suppressor (TS) lymphocytes together. The distribution of HNK 1+ cells within the tumors was diffuse except in nodular lymphomas of follicular center cell origin (centroblastic/centrocytic = cb/cc NHL). When evaluating the different histological subgroups, the highest number of HNK 1+ cells was found within the tumor areas of cb/cc, which contained about three times as many positive cells as the other NHL. High numbers were also found in the diffuse variant of cb/cc but not in centrocytic NHL. Different degrees of HNK 1+ cell densities were observed in lymphocytic lymphomas (4.426 +/- 754), with high numbers in about 30% of the patients. Splenic tissues of 6 hairy cell leukemias displayed lower numbers of HNK 1+ cells as compared with other low grade malignant NHL. In "large cell" NHL, the lymphoblastic subtype showed only sparse HNK 1+ cells (1.345 +/- 386). The number was significantly reduced in comparison to all other NHL (p less than 0.01) and markedly lower than in the other NHL of high malignancy (immunoblastic and centroblastic NHL, p less than 0.02). The diminuation was not due to a simple dilution phenomenon in a rapidly proliferating tumor, as TH and TS infiltrates were comparable to other NHL. Correlating results with the clinical course (available in 58 patients), significantly higher numbers of HNK 1+ cells were found in NHL of low malignancy (p less than 0.02), but patients with a favourable course did not differ from those with progressive disease (p less than 0.5). Patients treated by cytotoxic drugs showed higher numbers of HNK 1+ cells than those before or without treatment (p less than 0.02). Results on TH and TS cell numbers in comparison to HNK 1+ cells showed completely different patterns of infiltration.

Antibodies, Monoclonal↗
PubMed1985

Biochemical characterization of renal epithelial cell cultures (LLC-PK1 and MDCK).

The expression of enzymes in LLC-PK1 and MDCK cells was used to study the retention of differentiated properties of the renal epithelial cell lines by a biochemical approach. Activities of marker enzymes, for which intracellular and intranephron localization is known, were determined from crude cell homogenates of LLC-PK1 and MDCK monolayer cultures. The activity patterns of the particular enzymes found were then compared with the in vivo distribution of the enzymes along the rat nephron. LLC-PK1 cells exhibit high activities of apical membrane enzymes when compared with MDCK cells, whereas in the latter high activity of Na-K-ATPase could be detected. The activities of lysosomal enzymes, mitochondrial enzymes, and transaminases were higher in LLC-PK1 than in MDCK cells. Glycolytic enzymes, however, displayed identical activity levels in both the LLC-PK1 and MDCK cells, which may be due to the fact that these are continuous cell lines and to the culture conditions used, since glucose is a major energy source in the culture media.

Animals↗
PubMed1985

Interrelation between oxygen consumption and Na-K-ATPase activity in rat renal proximal tubule suspension.

The portion of Na-K-ATPase activity on oxygen consumption was determined in suspensions of rat proximal tubules by monitoring oxygen consumption (QO2) under different metabolic states: in the presence or absence of succinate or lactate (10 mmol/l) and increasing concentrations of ouabain (0.4; 0.8; 1.2 and 1.6 mmol/l). In the metabolic states tested, the ouabain induced decrease of QO2 was identical, which implies a fixed rate between Na-K-ATPase activity and QO2. On the basis of these results, Ki and maximal inhibition rate were determined by Lineweaver-Burk and Eadie-Hofstee plots Ki was 0.67 mmol/l ouabain and the maximal inhibition of QO2 was 77%. This corresponds to an absolute decrease of QO2 of 1,630 mumol O2 . h-1 . g-1 protein. Since this value represents the real portion of Na-K-ATPase on QO2, the activity of Na-K-ATPase can be calculated, yielding an activity of 163 mumol ATP . min-1 . g-1 tubule protein.

Animals↗
PubMed1984

Compartmentation of ATP within renal proximal tubular cells.

Studies on the relations between active solute transport and cell metabolism require not only knowledge of the total cellular ATP, but also of the separate mitochondrial and cytosolic ATP levels. For this purpose, mitochondrial and cytosolic fractions were separated from isolated proximal tubular suspensions by the digitonin technique and the amount of ATP analyzed separately for each compartment. In a parallel series of experiments, the absolute volumes of mitochondrial and extramitochondrial spaces were determined in rat renal cortical tubular suspension utilizing electron microscopic morphometry. When referring ATP measurements to the morphometrically determined absolute volumes, the ATP concentrations were calculated to be 4.33 mmol/l for the cytosolic and 2.62 mmol/l for the mitochondrial space. The cytosolic and mitochondrial ATP, thus, represent 70 and 30% of the total cellular ATP, respectively.

Adenosine Triphosphate↗
PubMed1984

[Urinary enzymes in the non-invasive diagnosis of kidney epithelial lesions in acute kidney failure].

The present investigation describes the urinary output of four different enzymes localized within nephron cells in two models of experimental acute renal failure. The activities of fructose-1,6-diphosphatase (FDP), glutathione-S-transferase (GST), N-acetyl-beta-D-glucosaminidase (NAG) and pyruvate kinase (PK) were determined in the urine of rats after maleate or HgCl2 intoxication. 2 hours after maleate intoxication the urinary output of FDP, GST and NAG was significantly increased above control values. 6 hours after HgCl2 poisoning FDP, GST and NAG showed increased urinary enzyme activities. The urinary activity of each enzyme was significantly increased 24 hours after intoxication. These results are in good accordance with the damage observed on light and electron microscopic investigations carried out with both experimental models. Furthermore, general problems of urinary enzyme measurements are discussed in this paper.

Acetylglucosaminidase↗
PubMed1984

Imbalance of helper and suppressor T lymphocytes in malignant non-Hodgkin lymphomas: an in situ morphometric analysis.

The number and distribution of reactive T cells within 100 malignant B-cell lymphomas were evaluated in situ by immunomorphometry using stereological methods. Findings were related to histological and clinical parameters. A mean of 2 X 10(4) reactive T cells/microliter tumour tissue was found. This corresponds to 40% of the T-cell content of normal lymphatic tissues. The distribution of reactive T cells within the tumours was diffuse except for centroblastic/centrocytic lymphomas. When evaluating the different histological entities a correlation between number of helper T cells, T helper:T suppressor (TH:TS) ratio and histological subgroups emerged, particularly in non-Hodgkin lymphomas of low-grade malignancy. The highest ratio was found in prognostically favourable subgroups, CLL (2.7 +/- 0.3) and tumour areas of centroblastic/centrocytic lymphomas (2.9 +/- 0.4). In contrast, a significantly lower ratio was found in centrocytic lymphomas (1.4 +/- 0.3) corresponding well to the worst prognosis of this subgroup. The relationship between the number of helper T cells in tumour tissues, TH:TS ratio and prognosis was confirmed and extended by the evaluation of clinical data. It could be shown that, independently of histological criteria, a close correlation exists between the number of T cells, particularly T helper cells within the tumour, TH:TS ratio and clinical course. Patients with a favourable course had 1.4 X 10(4) T helper cells/microliter tumour tissue compared to only 0.8 X 10(4) for patients with an unfavourable clinical course (p less than 0.01); the TH:TS ratio was 2.8 for the favourable and 1.8 for the unfavourable group, respectively (p less than 0.04). In contrast, neither treatment nor tumour stage had a clear-cut influence on the extent of T-cell infiltration.

B-Lymphocytes↗
PubMed1984

Immunocytochemical localization of gamma-glutamyl-transferase on isolated renal cortical tubular fragments.

The localization of gamma-Glutamyltransferase (gamma-GT, E.C.2.3.2.2) was studied on isolated tubular fragments from rat kidney cortex immunocytochemically. Monospecific antibodies raised in the goat against rat kidney gamma-GT were used. Antigoat immunoglobulin from the rabbit conjugated with ferritin was used for visualisation of the antibody binding sites. The enzyme was found to be localized at the brush border membrane of proximal tubules, the luminal membrane of distal tubules and collecting duct segments. The enzyme could further be localized on the antiluminal or basolateral cell membranes of proximal and distal tubular fragments, whereas no such localization was verified for collecting duct segments. The role of this basolateral gamma-GT localization in context with the kidney's ability to extract over 83% of the renal arterial glutathione (GSH) input during a single passage is discussed.

Animals↗
PubMed1983

Glutathione depletion and in vitro lipid peroxidation in mercury or maleate induced acute renal failure.

Nephrotoxic acute renal failure was experimentally induced in male rats by s.c. application of mercuric chloride and i.p. administration of maleate, respectively. Mercuric chloride and maleate are known to enhance the formation of free radicals and peroxides, which presumably overload the cell's natural elimination mechanisms for these highly reactive intermediates. In addition, a reduction in activities of superoxide dismutase, catalase and glutathione-peroxidase, enzymes responsible for the protection of cells against peroxidative action of superoxide anions and hyperperoxides was found. In both models of acute renal failure, enhanced lipid peroxidation in kidney homogenates in vitro, monitored as malondialdehyde production, was observed. Furthermore, HgCl2 and maleate may react with free SH-groups and thus lead to a depletion of glutathione in tubular cells. Indeed, renal cortical contents of reduced and oxidized glutathione were drastically diminished. These results suggest that alterations in membrane integrity, possibly caused by peroxidative processes, can be considered the cause underlying the well-known disturbances in renal function commonly observed during the initiation phase of HgCl2 and maleate induced acute renal failure.

Acute Kidney Injury↗