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P Hoeprich

Publications and source records attributed to P Hoeprich.

5 recordsLinked to original sources

Identification and synthesis of the epitope for a human monoclonal antibody which can neutralize human T-cell leukemia/lymphotropic virus type I.

A monoclonal antibody (mAb), designated 0.5 alpha, derived from a patient with adult T-cell leukemia was found previously to neutralize the human T-cell leukemia/lymphotropic type I (HTLV-I) virus in in vitro assays and bind to the major envelope glycoprotein (gp46) of HTLV-I (Matsushita, S., Guroff, M.R., Trepel, J., Crossman, J., Mitsuya, H., and Broder, S. (1986) Proc. Natl. Acad. Sci. U.S.A. 83, 2671-2676). We have designed experiments to determine the epitope for this mAb. Using simultaneous multiple peptide synthesis, we synthesized 481 overlapping octapeptides which corresponded to the sequence of gp46. We mapped the epitope for mAb 0.5 alpha to lie between residues 186 and 195 of gp46. This result was confirmed by independently synthesizing a peptide containing this epitope which bound specifically to mAb 0.5 alpha with an approximate Ka = 4 x 10(7) M-1. In addition, the peptide inhibited mAb 0.5 alpha binding to gp46 derived from T-cells infected with HTLV-I. This epitope containing peptide may facilitate understanding HTLV-1 infection of T-cells.

Amino Acid Sequence↗

Unexpected binding of an octapeptide to the angiotensin II receptor.

An octapeptide, TBI-22 (Lys-Gly-Val-Tyr-Ile-His-Ala-Leu), inhibited binding of angiotensin II by a solubilized angiotensin receptor partially purified from rabbit liver. This inhibition appears to result from competition for binding to the same receptor. Radioiodinated TBI-22, like angiotensin II, bound to the solubilized receptor with an affinity such that the binding was inhibited 50% by unlabeled TBI-22 or angiotensin II at nanomolar concentrations. The binding reaction, like that for angiotensin II, required p-chloromercuriphenylsulfonic acid and was reversed in the presence of dithiothreitol. TBI-22 and angiotensin II share the sequence Val-Tyr-Ile-His; this tetrapeptide alone, however, did not inhibit binding of angiotensin II. Replacement of the tyrosine residue by aspartic acid in TBI-22 greatly reduced the ability of the peptide to compete with angiotensin II for binding, suggesting an important contribution of this residue to the configuration required for recognition by the receptor.

Amino Acid Sequence↗

Autosterilization in low-velocity bullets.

Following a previous study (1) in which contaminated low-velocity bullets were discharged into sterile gelatin blocks with resultant growth of organisms along projectile tracts, the authors fired bullets coated with 1 drop of Staph. aureus-contaminated medium and bullets under sterile conditions into sterilized sand. Each contaminated projectile and its gun barrel were culture positive after firing. Therefore bullets should not be ruled out as possible sources of infection.

Sterilization↗

Bacterial peritonitis following esophageal injection sclerotherapy for variceal hemorrhage.

Patients presenting with ascites and upper gastrointestinal hemorrhage were studied prospectively. Five patients presenting with acute variceal hemorrhage were found not to have pre-existing spontaneous bacterial peritonitis on initial paracentesis. However, three of these five developed findings compatible with bacterial peritonitis after sclerotherapy. Although the number of cases is small, our results support the monitoring of ascitic fluid after sclerotherapy.

Adult↗