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R Lohmann

Publications and source records attributed to R Lohmann.

At least 73 records · Page 4Linked to original sources
PubMed1993

Column-switching solid-phase trace-enrichment high-performance liquid chromatographic method for measurement of buprenorphine and norbuprenorphine in human plasma and urine by electrochemical detection.

We describe a new high-performance liquid chromatographic method using electrochemical detection for the determination of buprenorphine and norbuprenorphine in plasma and urine. The minimum concentration for detection of buprenorphine and norbuprenorphine is 40 pg/ml. The intra-assay coefficient of variation (C.V.) in plasma and urine samples ranges from 6 to 17% depending on the drug concentration. At a plasma concentration of 500 pg/ml the inter-assay C.V. is 8% for buprenorphine and 9% for norbuprenorphine. The analysis duration is 16 min. After solid-phase extraction and evaporation a valve-switching system with two Rheodyne valves enables sample enrichment, optimal sample cleaning and rapid elution of long-retained substances.

Buprenorphine↗
PubMed1993

[Liver transplantation as a routine procedure? Indications and results in 270 patients].

AIM: To represent the current state of the art of orthotopic liver transplantation (OLT). The constantly expanding spectrum of indications are discussed in detail, and the specific risks of the individual indications considered. Major points discussed: On the basis of the authors' own results obtained at the Rudolf Virchow Hospital, University of Berlin, the current survival rates following orthotopic liver transplantation are shown. In addition to established indications for liver transplantation (primary biliary cirrhosis, primary sclerosing cholangitis, acute hepatic failure, various metabolic diseases, small hepatocellular carcinomas and a number of posthepatic cirrhoses) the indication and results of liver transplantation in HbsAg-positive and alcoholic cirrhosis are presented in detail. In contrast to reports in the Anglo-American literature, the incidence and severity of graft re-infections with the hepatitis virus was appreciably reduced through the use of anti-HBs hyperimmunoglobulin preparations in HBsAg-positive cirrhotics. The results obtained were comparable with those achieved for other indications.

Follow-Up Studies↗
PubMed1993

Retrospective statistical analysis of coagulation parameters after 250 liver transplantations.

Extensive transfusion of blood components as a typical feature of OLT has been described by many authors. The perioperative requirement for transfusion, however, follows a downward trend, although the indications for OLT have been extended. Functional disturbances such as hyperfibrinolysis or platelet dysfunction, demonstrated by laboratory tests, such as platelet counts, PT, aPTT, TT, fibrinogen, and ATIII are often used to direct the transfusion of blood components, although preoperative data give insight only into the insufficient function of the old liver, which will be explanted and replaced by the donor graft. We have described a retrospective statistical analysis of laboratory data, clinical data, and perioperative blood requirements from 250 liver transplantations performed in our hospital from 1988 to 1992. The OLT was performed according to the usual surgical methods using a venovenous bypass system. Intraoperatively, volume was restored with packed RBC and FFP according to hemodynamic data, hemoglobin, and diuresis; clotting data were not used as indications for blood replacement. This analysis demonstrated that neither preoperative nor intraoperative clotting parameters were able to allow a prediction of the intraoperative requirement for transfusion of blood components; these findings parallel those of previous reports. With respect to other studies showing that perioperative transfusion rates correlated with postoperative infections and mortality, we strongly suggest that perioperative clotting measures as indicators for transfusion requirement should be analyzed with caution. Whether other diagnostic methods such as TEG are useful alternatives has to be determined.

Adult↗
PubMed1993

Comparison of quadruple immunosuppression after liver transplantation with ATG or IL-2 receptor antibody.

Treatment with monoclonal IL-2 receptor antibodies has been successfully used for immunosuppressive induction therapy following organ transplantation in the recent past. The present study was conducted to compare for the first time a cyclosporine-based quadruple immunosuppressive regimen including a monoclonal IL-2 receptor antibody or ATG as induction therapy after orthotopic liver transplantation. In two groups of 33 patients each, postoperative survival, graft biopsies, liver function enzymes, and the clinical courses after OLT were evaluated. Our results indicate that monoclonal IL-2 receptor antibody therapy as part of a quadruple immunosuppressive regimen is better tolerated and is at least as effective as ATG in prevention of allograft rejection following OLT. Furthermore, our data indicate that a slightly better liver function in general and a lower incidence of rejection reactions necessitating treatment could be observed in the group of patients treated with the monoclonal IL-2 receptor antibody. This study provides evidence that monoclonal IL-2 receptor antibody therapy may be a useful tool for the immunosuppressive induction therapy following clinical orthotopic liver transplantation.

Adult↗
PubMed1993

Birth order and risk of sudden infant death syndrome: is the true relationship negative?

The risk of SIDS has been reported consistently as being positively related to parity or birth order. However, the reports in question have failed to take into account the possible confounding effects of sibship size. In the present study it was reasoned that if this were done the relationship would be negative, not positive. In an analysis of births stratified by sibship size positive. In an analysis of births stratified by sibship size occurring in the years 1975-84 in the state of Oregon, it was found that the risk of SIDS in the age range 7-364 days did indeed tend to decrease with increasing birth order when sibship size was held constant. An expected tendency for SIDS rates to increase with increasing sibship size when birth order was held constant was also confirmed. This tendency is probably explained by a negative correlation between family size and socio-economic status. Non-SIDS rates behaved in a similar manner to SIDS rates. The tendency for the risk of SIDS to decrease with increasing birth order was more evident when births following a pregnancy interval of less than 12 months were excluded.

Birth Order↗
PubMed1990

The prognostic significance of tumor ploidy and pathology in adenocarcinoma of the esophagogastric junction.

Tumor DNA content has been advocated to be an important prognostic indicator in human malignancies. Paraffin-embedded specimens of 75 resected adenocarcinomas (AC) of the esophagogastric junction were studied by flow cytometric DNA analysis to determine whether tumor ploidy was a significant prognostic variable independent of stage and histologic grade of the tumor. Eighty-one percent of the tumors were aneuploid. More patients with aneuploid tumors had lymph node metastases than patients with diploid tumors (P = 0.007). Patients with aneuploid tumors had poorer 18-month disease-free and overall survival than patients with diploid tumors. Cox regression analysis demonstrated that the most important prognostic variables for predicting overall survival were lymph node status, depth of wall invasion, and tumor differentiation. Tumor ploidy was not an independent prognostic variable in predicting recurrent disease or death from AC of the esophagogastric junction. Tumor DNA content is valuable, however, as a marker for patients at increased risk of lymph node metastases, early recurrence, and poorer survival.

Adenocarcinoma↗
PubMed1990

Risk of sudden infant death syndrome in subsequent siblings.

To determine the risk of recurrence of sudden infant death syndrome in families, we studied 251,124 live births by linked birth and death certificates from Oregon for a 10-year period. We found five recurrences among 385 subsequent siblings, for a rate of 13/1000 live births and a relative risk of 6. When the recurrences were adjusted separately for birth order and maternal age, the risk was still five times that expected (p less than 0.001). Families with infant deaths from causes other than sudden infant death syndrome had similar recurrence rates, suggesting that the phenomenon was not specific to sudden infant death syndrome. The overall mortality rate for subsequent siblings after a sudden death event totaled 20.8/1000. We believe that a risk of 2%, although small in the design of studies of infants at risk for sudden infant death syndrome, is not trivial in the counseling of parents.

Birth Order↗