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Biomedical subjects

C Lehmann

Publications and source records attributed to C Lehmann.

117 records · Page 7Linked to original sources
PubMedDate not supplied

Infection of macrophages by influenza A virus: characteristics of tumour necrosis factor-alpha (TNF alpha) gene expression.

Human monocytes and murine macrophages were found to be susceptible to influenza A virus infection. We could show that virus was absorbed and de novo virus protein synthesis was initiated, but actual virus replication was extremely low; 24-36 h after infection, monocytes and macrophages died of apoptosis. Before cell death, an influenza A virus infection induced strong mRNA accumulation of cytokines: tumour necrosis factor-alpha (TNF alpha), interleukin-1 (IL1) and IL6. However, the translation into bioactive cytokine protein was rather low, and high cytokine production was only found when a secondary signal such as LPS was added. Influenza A virus infection of mononuclear phagocytes displayed a characteristic feature at the level of cytokine gene transcription which was not found with other viruses such as vesicular stomatitis virus: in addition to the regular 1.7-kb TNF alpha mRNA, a high molecular weight (hmw) TNF alpha mRNA of 2.4 kb was detected. This hmw TNF alpha mRNA did not contain intron or intergenic region elements, was polyadenylated and carried the regular 5' and 3' untranslated regions. The generation of hmw TNF alpha mRNA required exposure to fully infectious influenza A virus, since virus inactivation at 56 degrees C induced only regular and not hmw TNF alpha mRNA. Whether this unique hmw TNF alpha mRNA represents a virus-induced abnormality or only a superinduction of an otherwise minor TNF alpha transcript, and whether this mRNA species codes for a biologically active product, remain to be further studied.

Animals↗
PubMedDate not supplied

Workflow analysis an international tool: cost reduction while retaining personnel.

Throughout the world, governments and health-care facilities have been under pressure to reduce the costs associated with providing health care. Through the use of workflow analysis, many laboratory administrators have identified cost-saving measures. Consolidating technology (workstations) and reducing personnel have generated significant cost reductions for the laboratory. However, there are parts of the world where it is impossible to displace personnel, for example Spain. This case study, conducted in Catalonia, Spain, demonstrates how laboratory administrators, through the use of workflow analysis, can identify cost-saving measures without reducing laboratory personnel.

Cost Savings↗
PubMedDate not supplied

Pre-analytical workflow analysis reveals simple changes and can result in improved hospital efficiency.

Workflow analysis is an ongoing process for laboratory managers. Throughout the years, laboratory managers have made many changes such as creating a core laboratory, consolidating technology, and implementing a new laboratory information system, all of which will have an immediate impact on laboratory operations. However, after implementation of any change in the laboratory, one should follow up with a pre- and/or postanalytical workflow assessment. This case study evaluates the pre-analytical impact of analytical changes made more than a year ago.

Child↗
PubMedDate not supplied

Up-regulation of telomerase activity in Herpesvirus saimiri immortalized human T-lymphocytes.

Human T-lymphocytes can be transformed to unlimited growth by Herpesvirus saimiri (HVS). We studied the telomerase activity of a recently established HVS immortalized human CD4 T cell clone in comparison to peripheral blood lymphocytes (PBL) and unstimulated or phytohemagglutinin (PHA)-stimulated CD4 T-cells by a Telomeric Repeat Amplification-Protocol (TRAP) -Assay. Telomerase activity in PHA-stimulated CD4 T-cells was seven-fold and in HVS-infected CD4 T-cells 14-fold higher than in untreated CD4 T-cells. The HVS immortalized T-cell clone provides a useful tool for studying the regulation of telomerase activity during carcinogenesis and for testing of telomerase-inhibitory drugs.

CD4-Positive T-Lymphocytes↗