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Biomedical subjects

K Hempel

Publications and source records attributed to K Hempel.

At least 73 records · Page 4Linked to original sources
PubMed1989

Characterization of the IL-2-receptor on rheumatoid arthritis synovial fluid T cells.

We studied the hypoproliferative response of synovial fluid (SF) T cells in rheumatoid arthritis (RA) using a mitogenic monoclonal antibody (MoAb) specific for the T-cell antigen receptor-associated CD3 complex. RASF T cells are defective in their proliferative response and in the induction of the Tac (p55) component of the IL-2-receptor (IL-2-R) when stimulated with anti-CD3 monoclonal antibody (MoAb). However, fresh RASF T cells bear demonstrable IL-2-R in cross-linking experiments which are not seen in unstimulated peripheral blood (PB). These receptors are functional since RASF T cells proliferate in response to recombinant IL-2 (rIL-2) better than fresh PB T cells from either normal or RA patients. Scatchard analysis indicates increased (4-fold) numbers of high affinity IL-2-R on (phytohaemagglutinin) PHA-activated RASF T cells as compared with comparably activated RAPB T cells. Phorbol myristate acetate (PMA) induces Tac antigen expression in RASF but does not lead to proliferation. The hyporesponsiveness of RASF T cells does not appear to result from lack of IL-2-R, lack of IL-2-R inducibility, or proliferative potential.

Adult↗
PubMed1989

Protection against experimental allergic encephalomyelitis with complete Freund's adjuvant is unaffected by prostaglandin synthesis inhibition.

Pretreatment with complete Freund's adjuvant blended with aluminium hydroxide (ALU-CFA) prevents the clinical as well as histological manifestation of experimental allergic encephalomyelitis (EAE) in Lewis rats. Suppression of prostaglandin biosynthesis with the cyclooxygenase inhibitor piroxicam (10 mg/kg body weight) from day 2 before to day 17 after EAE induction could not restore responsiveness in pretreated animals. In contrast piroxicam increased ALU-CFA-induced suppression of autoantibodies against myelin basic protein. In controls not pretreated with ALU-CFA, clinical signs of EAE were attenuated by piroxicam, whereas mononuclear infiltration of the brain remained unchanged. Therefore it is unlikely that prostaglandins exert an important function in the regulation of immune responses in this model of autoimmunity.

Adjuvants, Immunologic↗
PubMed1988

An experiment in surgical education--the first international exchange of residents. The letters of Halsted, Küttner, Heuer, and Landois.

Dr William Halsted firmly believed that the young physician achieved greater surgical maturity by observing the practice of surgery in countries in addition to his own. To promote this belief, Halsted initiated the concept of exchanging residents between training programs in different lands. This article presents a review of that historic first international exchange of residents. This glimpse into the past is accomplished by presenting previously unpublished letters of Halsted; Hermann Küttner, director of a surgical clinic in Germany; George Heuer, a resident from The Johns Hopkins Hospital, Baltimore; and Felix Landois, a resident from Küttner's clinic.

General Surgery↗
PubMed1987

No disturbance of myelination in the central nervous system by selective 3H beta-irradiation.

The effect of a selective irradiation of myelin by 3H beta-particles was studied by light and electron microscopic methods in guinea pig spinal cord. The animals were injected with [3H]leucine shortly after birth when the rate of myelin biosynthesis is high and sacrificed 130 days later. In spinal cord the radioactivity was mainly preserved in myelin because the half life of myelin proteins is much higher than that of most other CNS proteins. As a consequence the irradiation dose in the white matter was much higher than in the gray matter. In myelin internally irradiated by 3H beta-particles within 130 days at a dose of 10 Gy no alterations could be detected either by morphological or by morphometric methods.

Animals↗
PubMed1987

Determination of G-values for single and double strand break induction in plasmid DNA using agarose gel electrophoresis and a curve-fitting procedure.

Covalently closed circular double-stranded DNA (CC) of native plasmids was used to determine the yield of single strand breaks (ssb) and double strand breaks (dsb) as a consequence of X-irradiation. One ssb transforms DNA of the CC form to the nicked circular form (NC), whereas one dsb produced either directly or from random coincidence of single strand breaks transforms DNA of the CC as well as of the NC form to linear DNA molecules (LI form). Plasmids with more than one dsb are cleaved to linear fragments. DNA (30-800 micrograms/ml) was irradiated in air-saturated sodium phosphate buffer. The different forms of DNA were separated by gel electrophoresis and their amounts measured fluorometrically using ethidium bromide. Large linear DNA fragments with the same electrophoretic mobility as the LI form were considered by using a curve-fitting procedure. From the quantitative changes of each conformation D37 values of ssb and dsb were calculated as a function of the DNA concentration. Finally G-values were calculated by competition plots. The following yields were determined: Gssb 3.4 X 10E-8 molJ-1, and Gdsb 3.3 X 10E-10 molJ-1. Gdsb refers only to those dsb produced directly. Yields are related to strand breaks without further treatment by heat or alkali.

DNA↗
PubMed1987

Protection against experimental allergic encephalomyelitis with complete Freund's adjuvant is unaffected by ionizing irradiation.

Long-lasting resistance to experimental allergic encephalomyelitis (EAE) was obtained in Lewis rats either by an immunization with complete Freund's adjuvant blended with aluminum hydroxide (ALU-CFA) or by convalescence from EAE. Total body irradiation at a dose of 500 R given both 1 day after ALU-CFA (or disease induction) and EAE challenge did not abrogate the protection. No antibodies against myelin basic protein could be detected in irradiated animals. In contrast high antibody titers were measured in non-irradiated controls recovered from EAE and subsequently resistant to the disease. Therefore it is unlikely that antibodies against myelin basic proteins are of any importance in protection from EAE. The studies suggest that unspecific radioresistant suppressor cells play a role in resistance to EAE.

Adjuvants, Immunologic↗
PubMed1987

[Measures for reducing complications in anus praeternaturalis repair].

Colostomy closure has also today a complication rate between 20 and 30% in the literature, in which infectious complications are playing a substantial role. Increasing experience and standardization as well as better preoperative treatment, like whole gut irrigation and perioperative antibiotics and the additional use of a Gentamicin-PMMA-chain, led to a distinct reduction of the postoperative complication rate in a prospective study of 40 colostomy closures.

Adult↗