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W Sibrowski

Publications and source records attributed to W Sibrowski.

At least 73 records · Page 4Linked to original sources
PubMed1990

[CMV antibody determination with two enzyme immunoassays in each case].

In each of the two present studies (Frankfurt blood donor center and blood bank of the university of Hamburg) two commercial enzyme immunoassay (EIA) test kits for detecting cytomegalovirus (CMV) antibodies were compared according to their concordance. In the Frankfurt study, 448 sera of blood donors and patients were tested for IgG- and IgM-specific antibodies by CMV-ELA Test (Medac); IgG-specific antibodies were tested in 3 serum dilutions (1:10, 1:100, 1:1000) of each sample, 221 sera were additionally assayed using the EIA of ABBOTT. Both methods showed the same results in 214/221 (96.8%) sera (p less than 0.001). The determination of CMV-IgG-specific antibody levels were as follows: Out of 294 seropositive individuals, titers greater than or equal to 1:1000 were seen in 81% (238). IgM antibodies to CMV were determined in 22/448 serum specimen, which all had IgG antibodies too; there were 18/22 (81.8%) samples with elevated titers for CMV-IgG (greater than or equal to 1:1000). In the second study, 500 sera of blood donors from Hamburg were tested for CMV-IgG antibodies by two enzyme immunoassays, CMV-IgG-ELA (Medac) and Anti-CMV-IgG-ELISA (Biotest). The results were concordant in 418 (83.6%) of the 500 samples (p less than 0.01). All EIA procedures were found to be convenient test methods for CMV antibody screening and the results showed significant correlations. Furthermore, the determination of CMV-IgG-specific antibodies seems to be sufficient for routine CMV screening in blood donor centers.

Antibodies, Viral↗
PubMed1990

[Analysis of irregular antibodies in the department of transfusion medicine 1984-1988].

In the University Hospital of Hamburg we performed approximate 80,000 screening tests for irregular RBC antibodies in the years 1984-1988. Among 1,815 (2.27%) positive tests, Rhesus and concomitant antibodies occurred in 0.77% (615/80,000), other clinically important antibodies in 0.37% (293 cases). We found significantly less Rh antibodies than in the previous period of the mid seventies (Rh prophylaxis, completely Rh-compatible transfusions).

Blood Group Incompatibility↗
PubMed1990

[Rapid and sensitive determination of the adenylate energy charge in stored erythrocytes using high pressure liquid chromatography].

Using reversed-phase high-performance liquid chromatography (HPLC), we developed a fast method for the determination of the adenine-nucleotides ATP, ADP, and AMP in human red blood cells (RBC). The method is sensitive (10(-9)-10(-10) M), specific (greater than 95% peak-homogeneity), and the results are well reproducible. The three substances are assayed in a single step, which is essential for the exact determination of the adenylate-energy-charge (AEC). We applied the technique to fresh and stored RBC's. After six weeks' storage in PAGGS-sorbitol we found only a slight decrease in ATP content, but marked increases in ADP and AMP contents. Accordingly, there was a decrease in the AEC, whereas the total nucleotide pool (TNP) did not change significantly. As AEC and TNP reflect the state of the cellular energy metabolism, they are related to the viability of stored RBC. Thus, we consider the described method to be helpful for the quality control of RBC stored in new or modified media.

Adenine↗
PubMed1990

[Analysis of irregular antibodies at the department of transfusion medicine of the Hamburg-Eppendorf University Hospital 1984-1988].

In the University Hospital of Hamburg-Eppendorf (UKE) we performed approximately 80,000 screening tests for irregular RBC antibodies in the years 1984-1988. Among 1,815 (2.27%) positive tests, Rhesus and concomitant antibodies occurred in 0.77% (615/80,000), other clinically important antibodies in 0.37% (293 cases). We found significantly less Rh antibodies than in the previous period of the mid seventies (Rh prophylaxis, completely Rh-compatible transfusions).

Blood Group Incompatibility↗
PubMed1990

[Significance of cytomegalovirus in blood donation].

The subjects of the present study are diagnostic and epidemiologic aspects in the determination of serum antibodies to cytomegalovirus in blood donors, organ donors, dialysis patients and drug addicts (some of whom were HIV-positive); antibodies were determined using the ELA-Test (CMV-IgG ELA and CMV-IgM-ELA). 221 sera were additionally assayed using the CMV total AB EIA which has been used in the Frankfurt blood center since May 1985 for CMV antibody screening of blood donors: both enzyme immunoassays showed the same results in 214 sera (96.8%), which shows a high rate of correlation (requiv = 0.99, p less than 0.001). The groups were found to be CMV antibody positive as follows: blood donors 65/102 (63.7%), organ donors 10/13 (76.9%), dialysis patients 88/106 (83.0%), drug addicts 131/227 (57.7%), and HIV-antibody-positive drug addicts 17/31 (54.8%). There was a significant statistical difference between blood donors and dialysis patients (p less than 0.01); the difference between blood donors and drug addicts was also statistically significant when age was considered (p less than 0.001). There was no statistical significance in the distinction between HIV-negative and HIV-positive drug addicts. IgM-specific antibodies were found in 1/102 (0.98%) blood donors, 18/106 (17.0%) dialysis patients and 3/227 (1.3%) drug addicts, whereas in organ donors no IgM-specific antibodies were determined. The seropositivity rate of a Frankfurt group of regular blood donors (n = 1826) was 55.5%.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1990

[Hepatitis C virus (HCV) antibodies in German blood donors--a pilot study].

A new EIA-test to detect Hepatitis C antibody (ORTHO Diagnostic Systems) has been evaluated in four blood transfusion services in FRG (Hamburg, Hannover, Springe, Frankfurt). Among 3,123 specimens, 18 (0.58%) reacted initially positive, 13 (0.42%) remained positive after repeat testing. A detailed analysis revealed remarkable differences: blood donors from the northern part of Germany were less frequently positive than donors from the southern region (0.24% vs. 0.79%), repeat donors had a higher HCV-antibody incidence than first-time donors (0.48% vs. 0.29%). Similar differences were observed between remunerated and non-remunerated donors (0.24% vs. 0.53%), as well as between donors from rural and urban areas (0.34% vs. 0.46%). In contrast to other investigators, only a weak correlation between elevated ALT-levels (greater than 50 IU/ml) and anti-HCV seropositivity rate has been found.

Antigens, Viral↗
PubMed1989

Association of HLA antigens with progressive systemic sclerosis and morphea.

The HLA phenotype frequencies of 40 patients with progressive systemic sclerosis (PSS) and 42 patients with morphea (sclerodermia circumscripta) indicate a weak, HLA-linked genetic predisposition of the affected individuals (70 female, 12 male). An "opposite" HLA A1, B8 (high immune response) vs A3, B7, DR2 (low immune response) constellation in PSS and morphea supports the clinical subdivision of scleroderma into these different nosological entities, and may serve as a differential diagnostic tool and prognostic marker.

Female↗
PubMed1989

[Post-transfusion non-A, non-B hepatitis: is a specific test in sight?].

The prevention of non-A, non-B hepatitis (NANB-PTH) is of the utmost importance in the blood bank setting, since the estimated attack rate amounts to 0.1-1.0% in Germany and greater than or equal to 2% in the USA. The value of 'surrogate markers', anti-HBc and ALT, remains a matter of controversy. In early 1988, a small (60 nm), single-stranded RNA-virus (toga- or flaviviridae), probably causing both sporadic and parentally transmitted NANBH was isolated, partially cloned by a lambda gt 11 expression vector and named hepatitis C virus (HCV) by Choo, Houghton et al. The HCV fusion protein was used to detect specific antibodies by EIA in patients with NANBH. Preliminary data obtained with this EIA (Chiron Corp., Emeryville, Calif., USA) in US blood donors yielded a seroprevalence rate of 0.7%. of 8.3% in donors with a history of hepatitis, of 5.1% in donors with ALT levels greater than or equal to 65 IU, and of 45% in NANB patients. Investigations of critical 'blood donor/transfusion recipient' pairs revealed a 73% correlation of concordant seropositiveness. The evaluation of an improved HCV antibody EIA (Ortho Diagnostic Systems, Neckargemünd, FRG) will be the subject of a German multicentre pilot study scheduled for 1989. The introduction of this HCV test should drastically reduce the most serious infectious risk of homologous blood transfusion. Efforts are being made to develop an HCV vaccine.

Blood Banks↗
PubMed1987

Low prevalence of particle-associated reverse transcriptase activity in serum from patients with non A - non B hepatitis.

Sera from 367 patients presumed to have NANB hepatitis were screened for reverse transcriptase activity. In 29 cases significantly increased enzyme activities could be observed. In contrast, sera from 338 patients did not contain significant reverse transcriptase activities. 207 healthy individuals, 7 patients with hepatitis A and 6 patients with hepatitis B who served as controls were all negative for reverse transcriptase activity. The specificity of the enzyme assay was demonstrated by estimation of reverse transcriptase activity in sera from 10 "healthy" HIV-1-antibody positive individuals. In 3 out of 10 cases significant reverse transcriptase activity was observed associated with the human immunodeficiency virus. Our results indicate that the presence of particle-associated reverse transcriptase activity in serum from patients with NANB hepatitis is indicative of the presence of a retrovirus-like agent in these cases. However, the relatively low prevalence of reverse transcriptase positive cases associated with the NANB hepatitis makes it rather questionable whether this agent is a frequent and specific factor in the etiology of NANB hepatitis.

Acquired Immunodeficiency Syndrome↗
PubMed1984

Rapid action of insulin and cyclic AMP in the regulation of functional messenger RNA coding for glucokinase in rat liver.

The mRNA activity coding for rat liver glucokinase was measured in vivo under different hormonal and nutritional conditions. Starvation resulted in minimal levels of glucokinase mRNA activity. Glucose refeeding caused a 4-fold induction of glucokinase mRNA within 48 h, which followed similar alterations in enzyme activity. Minimal values for glucokinase mRNA were also measured in diabetic animals fed glucose and were significantly elevated by insulin injection within 1.5 h. Administration of dibutyryl cyclic AMP to glucose-fed rats caused a rapid loss of the specific mRNA. The half-life of glucokinase mRNA, determined after the administration of cordycepin to glucose-fed animals, was approximately 40 min. This half-life was unaffected by the administration of dibutyryl cyclic AMP. Glucokinase mRNA was reduced 60% in glucose-fed adrenalectomized or thyroidectomized rats. The activity of the glucokinase mRNA agreed well with the measured rates of enzyme synthesis. These data indicate that insulin regulates hepatic glucokinase synthesis in vivo by increasing glucokinase mRNA; its effect is reduced by the absence of glucocorticoids or thyroid hormones and is rapidly antagonized by cyclic AMP.

Animals↗
PubMed1982

Renal phosphoenolpyruvate carboxykinase turnover in hypo- and hyperthyroid rat in vivo.

The effect of hypo- and hyperthyroidism on activity, synthesis and degradation of renal cytosolic phosphoenolpyruvate carboxykinase (GTP) (EC 4.1.1.32) was studied in the rat by radioimmunological techniques. In hypo- and euthyroid rats, starvation induced similar alterations in enzyme activities and relative rates of synthesis, whereas in hyperthyroid rats the increase in both was significantly reduced. Substitution of L-thyroxine in hypothyroid rats resulted in a decrease in activity and synthesis within 18 h as observed in hyperthyroid animals. The apparent half-life of the enzyme measured by double-pulse labeling experiments was approx. 13 h in euthyroid animals. The rate of degradation was unaffected by the different thyroid states.

Animals↗
PubMed1982

Accelerated turnover of hepatic glucokinase in starved and streptozotocin-diabetic rat.

Rat liver glucokinase synthesis and degradation was estimated in fasted/fed and diabetic/diabetic-insulin-treated rats by the radioimmunological technique. Starvation and Streptozotocin-diabetes led to basal rates of synthesis and, consequently, to low levels in enzyme activity. In addition, a decrease in the apparent half-life from about 19 h in the fed or diabetic-insulin substituted to about 11 h in the starved or diabetic rat, respectively, was observed. Injection of Bt2cAMP into glucose-fed animals reduced glucokinase synthesis to basal levels within 90 min, without affecting enzyme activity. It is concluded that in metabolic states associated with elevated levels in tissue cAMP glucokinase synthesis is reduced to basal values and, in addition, its rate of degradation is significantly enhanced.

Animals↗
PubMed1982

3,5,3'-Triiodothyronine-induced synthesis of rat liver phosphoenolpyruvate carboxykinase.

Recent studies have indicated that the starvation induced increase in hepatic phosphoenolpyruvate carboxykinase (PEPck; EC 4.1.1.32) is accelerated in hyperthyroid animals, whereas enzyme degradation is unaffected by the thyroid state. Therefore, the present study was undertaken to investigate the possible direct effect of T3 on the synthesis of this important gluconeogenic regulatory enzyme in vivo and in the isolated perfused liver. T3 injection in hypothyroid animals stimulated PEPck synthesis within 6-12 h. The effect, being dose dependent and significant for 0.1 microgram T3/100 g BW, could be demonstrated in animals fasted or fed a carbohydrate-rich diet. Although varying in the basal rate of synthesis, the T3-induced increase in PEPck synthesis was similar in intact, thyroidectomized, adrenalectomized, and hypophysectomized animals. No additive effect with glucocorticoids was observed, suggesting that endogenous glucocorticoids are not necessary for the hormone action. The T3-induced effect on PEPck synthesis was not mediated by alterations in the endogenous cAMP level, as was indicated (1) by the different time course of PEPck induction via (Bu)2cAMP or T3, and 2) by the finding that T3 was effective also in diabetic animals, despite maximally enhanced tissue cAMP levels. In these animals insulin antagonized the T3 action on the enzyme. T3-mediated PEPck synthesis was not prevented by propranolol. Conversely, an additive effect with isoproterenol on enzyme activity was observed. T3 (1 nM) added to the isolated liver of hypothyroid rats perfused with the synthetic fluorocarbon medium supplemented with 10% iodothyronine free serum, stimulated incorporation of labeled leucine into PEPck protein within a 6-h perfusion time. Taken together, our data demonstrate that T3 at a physiological dose stimulates hepatic PEPck synthesis.

Adrenalectomy↗
PubMed1981

Effect of different thyroid states on rat liver glucokinase synthesis and degradation in vivo.

The role of different thyroid states on the rate of rat liver glucokinase synthesis and degradation was studied in vivo by the radioimmunochemical technique. In eu- and hyperthyroid starved rats, glucose refeeding induced a rapid and similar increase in glucokiase synthesis and activity, whereas in hypothyroid rats, only minor alterations in synthesis and activity was observed. 3,3',5'-Triiodo-L-thyronine substitution in hypothyroid animals restored the response of the enzyme within 24 h. The thyroid states per se had only a minor effect on glucokinase synthesis during the starvation period. In addition, in hypo-, eu-, and hyperthyroid rats adapted to a glucose diet, glucokinase degradation was estimated by double-pulse-labeling experiments, applying [14C]- and [3H]leucine. From the 3H/14C ratios, similar apparent half-lives were calculated: 17-19 h. It is concluded that thyroid hormones in their physiological range are an essential factor in the induction of hepatic glucokinase in vivo, exerting their action probably via a "permissive" effect, yet the degradation rate is unaffected by the thyroid state.

Animals↗