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Biomedical subjects

R Kantor

Publications and source records attributed to R Kantor.

25 records · Page 2Linked to original sources

Preparation of fingernails for trace element analysis.

There are substantial differences in the reported elemental composition of human nails. Most investigators have used extensive washing procedures to minimize environmental contamination, however, such washing poses the risk of extraction of elements bound to the nail matrix. To determine if a portion of this variability could be accounted for by the "washing solutions" used by different investigators, nails were washed in nine solvents previously used for cleaning nails and their residual elemental composition measured by atomic absorption spectroscopy or energy dispersion analysis. In general, treatment with organic solvents resulted in less elemental loss than did treatment with aqueous detergents, while aqueous acids caused the greatest loss. Organic solvents more readily extracted iron and magnesium than calcium, copper and zinc. Virtually all of the magnesium was extracted by distilled water or aqueous detergents.

Calcium↗

Studies of the normal human placental syncytiotrophoblast membrane: a combined immunological and physiochemical approach.

In view of the importance of the syncytiotrophoblast in the immunobiology of human pregnancy, the composition of this interface between fetus and mother was further studied by a combination of physicochemical and immunological approaches. Trophoblast membranes were solubilized using three classes of detergents: zwitterionic (sulfobetaine14), non-ionic (Triton X-100), and anionic (deoxycholate). Quantitative studies of protein released demonstrated the importance of dispersion of membranes into detergent, and optimum solubilization was then obtained at detergent:protein ratios of 1.3:1 for sulfobetaine, 2.5:1 for Triton X-100, and 4.4:1 for deoxycholate. Analysis of chaotrope-treated detergent-solubilized membrane components was performed by preparative isoelectric focusing followed by combined physiocochemical and immunological methods. The results revealed three major proteins which were identified as placental alkaline phosphatase, albumin, and transferrin. Certain additional low molecular weight proteins were also evident; one of these components displayed physicochemical properties similar to those of actin, but none appeared to be recognized by conventional heteroantisera raised to trophoblast membrane. These findings and the results of further immunological analysis by affinity chromatography are consistent with the concept that human trophoblast may express limited immunogenicity due in part to the presence of large amounts of absorbed maternal serum components and limited expression of fetal proteins.

Albumins↗

Prevalence of a CCR5 gene 32-bp deletion in an Israeli cohort of HIV-1-infected and uninfected hemophilia patients.

OBJECTIVE: The recently discovered connection of chemokines and their receptors to HIV pathogenesis, and the description of the 32-bp deletion in the CCR5 gene (delta 32 CCR5), led to heightened excitement and numerous reports regarding their role in HIV transmission and disease progression. The populations in most of these reports, except for one, consisted of homosexual men. Our objective was to investigate the significance of delta 32 CCR5 in hemophilia patients in Israel. STUDY DESIGN/METHODS: We have determined by polymerase chain reaction (PCR) the prevalence of delta 32 CCR5 in 34 HIV-seropositive Israeli patients with hemophilia A and compared them with a control group of 42 HIV-seronegative hemophilia patients. RESULTS: Thirteen heterozygotes were identified among the 76 hemophilia patients tested (allelic frequency, 8.5%), 5 (14.7%) among the HIV-seropositive patients, and 8 (19%) among the noninfected. CONCLUSIONS: No protective advantage to delta 32 CCR5 heterozygosity was seen as far as infection with HIV is concerned. However, a trend of a slower progression to AIDS in delta 32 CCR5 heterozygotes compared with wild-type homozygotes may be apparent, although no absolute correlation could be made.

Cohort Studies↗

[Monoclonal antibodies and uveal melanomas].

The authors, who have succeeded since 1976 in cultivating cells of ocular melanoma in continuous lines report the different stages for producing specific monoclonal antibodies. They particularly insist on the demonstration, through radioimmunoassay, of the specificity of marked monoclonal antibodies, on the immunohistochemical study and on biodistribution. From these data, an immunotherapy protocol has been perfected and starts being applied to human beings.

Animals↗