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Biomedical subjects

P Froese

Publications and source records attributed to P Froese.

16 recordsLinked to original sources
PubMed1992

Systemic levels of tumor necrosis factor alpha during hemodialysis with cellulosic membranes: no effect of the sterilization procedure.

Extractable constituents of dialyzer membranes (e.g., monomers and beta-glucans) may induce the production of cytokines in vitro. We therefore studied circulating tumor necrosis factor alpha (TNF alpha) levels in 23 stable hemodialysis patients during treatment with dry Cuprophan membranes (ETO-sterilized n = 10, steam-sterilized n = 13) longitudinally over a period of 4 weeks. After 4 weeks, those 5 patients of each group showing the highest TNF alpha levels were switched to steam-sterilized, wet Cuprophan membranes. No significant increase in plasma TNF alpha was observed during hemodialysis with either ETO- or steam-sterilized dry Cuprophan membranes. A substantial TNF alpha increase (> or = 100% compared to pre-HD values), however, was observed during 14 of 84 treatment sessions. In 5 selected patients with ETO-sterilized, dry Cuprophan dialyzers, TNF alpha rose from (mean +/- SEM) 17.2 +/- 3.0 (pre-HD) to 20.9 +/- 6.2 (120 min) and 21.9 +/- 4.5 pg/ml (240 min). Corresponding levels in patients with steam-sterilized, dry Cuprophan were 16.2 +/- 5.4 (pre-HD), 21.9 +/- 6.8 (120 min), and 16.0 +/- 3.7 pg/ml (240 min), respectively. There was no difference between ETO- and steam-sterilized dialyzers. No significant reduction in mean TNF alpha plasma levels or in frequency of elevated peak levels was achieved when these patients were switched to wet Cuprophan dialyzers for another 4 weeks. It is suggested that an induction of elevated TNF alpha levels during hemodialysis is possible but is not observed regularly during treatment with Cuprophan membranes.(ABSTRACT TRUNCATED AT 250 WORDS)

Cellulose↗
PubMed1992

Variables associated with the assessment of systemic tumor necrosis factor alpha levels during hemodialysis.

Conflicting results have been published concerning the systemic induction of the cytokine tumor necrosis factor alpha (TNF alpha) during hemodialysis (HD). We therefore evaluated in vitro TNF alpha production in whole blood as well as in vivo variability of TNF alpha levels in patients on long-term HD. Whole blood was incubated at room temperature (RT) with or without exogenously added endotoxin (ET), and plasma-TNF alpha was measured after 5, 30, 120, 240, and 960 min by specific enzyme immunoassay. Additionally, plasma-TNF alpha before and after 120 and 240 min HD was studied longitudinally once a week over a period of 4 weeks in 36 patients on Cuprophan (CU, n = 23) or polysulfone-F60 (PSu, n = 13) HD. Mean plasma TNF alpha levels in vitro rose from (mean) 8 pg/ml after 5 min to 12 pg/ml (120') and 32 pg/ml (960') even without ET addition, and to 18 pg/ml (after 120') and 88 pg/ml (after 960') when 0.1 microgram/ml ET were added. Pre-dialytic as well as intra-dialytic TNF alpha levels in patients showed high intra-individual variability. A substantial (> 100%) increase in plasma TNF alpha was observed during only 14 out of 84 treatments with CU and 20 out of 47 with PSu, however, the increase in TNF alpha was not statistically significant in either group. We conclude that the sampling procedure, if not carefully standardized, is a potential source of artifacts with regard to "systemic" TNF alpha levels. The high intra and inter-individual variability of plasma TNF alpha suggests that results of cross-sectional studies are questionable.

Cellulose↗
PubMed1987

Biochemical characterization and biosynthesis of the Ki-1 antigen in Hodgkin-derived and virus-transformed human B and T lymphoid cell lines.

The Hodgkin-associated Ki-1 antigen was analyzed in different cell lines. In Hodgkin analogous L428 cells, biosynthetically labeled with radioactive amino acids, the Ki-1 antibody precipitated three glycoproteins with 90, 105, and 120 kDa, respectively. Surface-labeling revealed that the two larger components were membrane-associated forms of the Ki-1 antigen, although the 90-kDa molecule was shown in pulse-chase experiments to be the precursor of the 105- and 120-kDa forms. All three forms of the Ki-1 antigen possess a tunicamycin-sensitive 6-kDa N-linked carbohydrate moiety. O-Linked oligosaccharides could not be detected. Thus, the differences in m.w. are probably not due to glycosylation. The ionophore monensin prevented the appearance of the membrane-associated molecules, which demonstrated that they are assembled between the transcompartment of the Golgi complex and their insertion into the cell membrane. The 90-kDa precursor molecule cannot be generated by disulfide reduction from the two larger forms. After internal labeling with P-32, only the 105- and 120-kDa bands became visible, indicating that the Ki-1 molecule is phosphorylated after its processing into the two larger membrane-associated forms. Analysis of the Ki-1 antigens from other cell lines demonstrated that after external labeling of two other Hodgkin-derived cell lines, six Epstein-Barr virus lymphoblastoid cell lines and one human T leukemia virus I-positive T cell line, both the 105- and the 120-kDa membrane molecules could be detected, regardless of the presence or type of virus integrated.

Antigens, Neoplasm↗
PubMed1987

[Skin changes in hemodialysis patients].

188 patients undergoing long-term hemodialysis and a control group of 371 patients without kidney diseases were examined with regard to changes of the connective tissue of the skin. The following alterations were observed: increased sensibility to low temperatures and Raynaud's syndrome (42%), Dupuytren's contracture (22.4%), sclerosis of the dorsum of the fingers (17.6%). Carpal tunnel syndrome was seen in 24.4% of the cases, significantly correlating with the duration of hemodialysis.

Female↗
PubMed1979

[Effect of Co-trimoxazole on renal creatinine excretion in man (author's transl)].

Clinical observations have shown, that administration of Co-trimoxazole (Trimethoprim-Sulfamethoxazole) may result in an elevation of the serum-creatinine level. In 27 subjects the endogenous creatinine- and inulinclearance were measured before and during oral or parenteral application of Co-trimoxazole. The inulinclearance showed no significant differences (p greater than 0,05). But the endogenous creatinine clearance showed a reduction of 18% during the oral and of 13% during the parenteral treatment (p less than or equal to 0,05). These observations indicate a functional inhibition of the tubular creatinine secretion by Co-trimoxazole.

Adult↗
PubMed1975

[Cephalothin and platelet enzymes in chronic renal failures].

Cephalothin inhibits the activities of platelet enzymes, succinic dehydrogenase and NADH-cytochrome-c-reductase in patients with chronic renal failure. Two hours after Cephalothin administration the return of enzyme activities to baseline values was dependent on the severity of the chronic renal failure, and the higher the serum-creatinine concentration, the slower was the return to original enzyme activities.

Blood Platelets↗
PubMedDate not supplied

Chronic induction of C-reactive protein by hemodialysis, but not by peritoneal dialysis therapy.

OBJECTIVE: Evaluation of the inflammatory activity in patients on chronic peritoneal dialysis (PD) and patients on chronic hemodialysis (HD) in comparison to patients with chronic renal insufficiency without dialysis treatment and healthy volunteers. DESIGN: Open, nonrandomized prospective study. SETTING: Nephrology Department, including HD and PD therapy in a university hospital. PATIENTS: Twenty-four patients on chronic PD,21 patients on chronic HD therapy using a cuprophan dialyzer,16 patients with chronic renal insufficiency without dialysis treatment, and 33 healthy volunteers; 8 additional patients before and after initiation of chronic HD therapy. All patients and controls were without infection or immunosuppressive therapy. MAIN OUTCOME MEASURES: As a marker of the inflammatory activity in the different patient groups, C-reactive protein (CRP) was measured serially using a sensitive, enzyme-linked, immunosorbent assay in order to detect values below the detection limit of standard assays. RESULTS: Patient groups had CRP levels higher than the normal controls (p < 0.01). Patients on HD had CRP levels significantly higher than PD patients (p < 0.01) whose levels were comparable to patients without dialysis therapy. Accordingly, longitudinal measurements before and after initiation of chronic HD showed a significant increase in CRP levels after the beginning of HD treatment (p < 0.04). CONCLUSIONS: The results suggest that induction of the inflammatory activity is lower during PD compared to HD, since stimulation by the dialyzer membrane, dialysate buffer, or bacterial fragments in the dialysate is avoided. This observation might indicate a possible lower risk of long-term complications in patients with PD.

Acute-Phase Reaction↗