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Biomedical subjects

C Horne

Publications and source records attributed to C Horne.

24 records · Page 2Linked to original sources
PubMed1987

Determination of verapamil and norverapamil in human biological material. Investigation of plasma concentrations after oral administration of two different verapamil formulations.

A method for the simultaneous determination of the cardiovascular agent verapamil and its major metabolite norverapamil in human plasma is described. Analysis is performed after alkaline extraction with n-heptane by subsequent ion-paired high performance liquid chromatographic (HPLC) separation, and direct fluorimetric measurement of both compounds (lambda maxex. = 278 nm, lambda maxem. = 320 nm). The sensitivity of the procedure (detection limit less than 1 ng/ml) is suitable for pharmacokinetic studies after therapeutic doses. The applicability of the method was tested by performing a clinical study. Plasma concentrations of two verapamil formulations for oral administration were examined. The active metabolite norverapamil was included in the investigation.

Administration, Oral↗
PubMed1985

Noncovalent association of heavy and light chains of human immunoglobulins. IV. The roles of the CH1 and CL domains in idiotypic expression.

A rabbit anti-idiotypic antiserum was raised against a monoclonal human IgM kappa(Me) in order to analyze the possible modulation of idiotypic expression by Fab constant domains. IgM(Me) fragments, subunits, and domains were prepared by chemical and enzymatic cleavages. All molecular species were shown to have a well-defined secondary and tertiary structure by circular dichroism. Full recombination between domains and subunits was ascertained by difference spectroscopy. The expression of the idiotype on native and recombined fragments, domains, and subunits was quantitated in a competitive enzyme-linked immunosorbent assay (ELISA). Reduced and alkylated Fab, isolated H and L chains, purified Fv(Me), intact VH and VL domains and H-L, VH-L, VL-H, and VH-VL recombinants were compared on a molar basis to native Fab(Me) for idiotypic expression. VH-specific determinants were found, whereas the L chains were virtually devoid of idiotypic activity. Both the peptic FV(Me) fragment, which is composed of intact VH and VL domains, and the recombined VH-VL heterodimer were found to be fourfold less active for idiotype expression than native Fab(Me). However, full inhibition was achieved at high molar concentrations, suggesting that all the idiotopes present on Fab(Me) were expressed on FV(Me) but with a reduced antigenicity. Comparison of VH-L and VL-H hybrid molecules revealed that the presence of the C mu 1 domain was sufficient to restore full idiotypic expression as compared with native Fab(Me). These data support the hypothesis that the first constant domain of the mu heavy chain alters the quaternary interaction between the variable domains, and therefore modulates the expression of the idiotype through longitudinal interactions that are not affected by reduction of the inter-H-L chain disulfide bond.

Antibodies, Anti-Idiotypic↗
PubMed1983

Relationship between the level of estrone sulfate in the plasma and the number of fetuses during pregnancy in the gilt.

Estrone sulfate was measured in the plasma of pregnant and nonpregnant gilts between Days 10 and 32 after estrus. Estrone sulfate was found to rise sharply in pregnant gilts beginning at Day 18 and to decline at Day 30 to Day 32. Estrone levels were not related to litter size. The level of estrone sulfate on Days 20, 22, 24 and 26 was significantly correlated with litter size at slaughter on Day 32. Reduction of the number of live fetuses by crushing them in utero at Day 40 or between Days 30 to 60 did not cause a subsequent reduction in the level of estrone sulfate, whereas reduction at Day 24 did cause a decline in estrone sulfate. The level of estrone sulfate in plasma of gilts at 20 to 28 days after mating was higher in pregnant than in nonpregnant gilts. The relative level of estrone sulfate would enable one to estimate litter size at Days 20 to 28 days but not later. Because of the limitations of the assay in exact quantitation of the levels of estrone sulfate, the results can only be considered qualitative.

Animals↗
PubMed1982

Noncovalent association of heavy and light chains of human immunoglobulins. III. Specific interactions between VH and VL.

Mildly reduced monoclonal human IgM proteins have been cleaved at cysteinyl residues to give VH fragments after S-cyanylation with 2-nitro-5-thiocyanobenzoic acid. The noncovalent interaction between the VH fragments and autologous kappa-chains was studied by ultraviolet difference spectroscopy and circular dichroism. A bimolecular complex was formed with an association constant in excess of 10(7) M-1 at 23 degrees C. Complex formation was accompanied by burial of tryptophan and tyrosine side-chains. In contrast to the studies with autologous species, the VH fragments did not associate with heterologous kappa-chains as judged both by difference spectroscopy and gel filtration using radiolabeled VH fragments. This specificity in the association between VH and VL has been attributed to interactions contributed to by residues in the third hypervariable region of VH encoded by the DH and JH genes.

Binding Sites, Antibody↗
PubMedDate not supplied

An interdisciplinary community-based clinical experience for beginning students.

Student and faculty evaluations of this program are consistently positive. Faculty members from the two colleges continue to develop improved collegial relationships. Students work well in interdisciplinary teams and value the unique contribution of each profession to high-quality client care. This program is now an integral component of the first semester curricula for the two Colleges. Faculties from each College continue to develop skills in interdisciplinary education. Currently, a pilot program is underway that includes the Colleges of Nursing, Pharmacy, and Medicine with a focus on interdisciplinary education and aging. This pilot program developed as a result of the success of the interdisciplinary program between the Colleges of Nursing and Pharmacy.

Attitude of Health Personnel↗