Zinc and Cadmium in Normal Human Embryos and Fetuses

Zinc and cadmium concentrations were determined in 36 first trimester intact human embryos and in liver, brain, and kidney of 14 second and 1 third trimester fetuses.

Zinc was found in all first trimester specimens. It increased sevenfold between the 31st and 35th day of gestation. Cadmium was present in 57% of specimens in concentrations from 0.032μg/gm to 0.07μg/ gm of wet tissue. In second trimester specimens, mean zinc concentration in brain was 5.6μg, in kidney 15.7μg, and in liver 167.7μg. Cadmium was present in 80% of livers (mean, 0.113μg/gm), 28% of kidneys (mean, 0.05μg/gm), and 17% of brain specimens (mean, 0 140μg/gm).

Mothers of these abortuses did not live in areas of Japan where endemic cadmium poisoning exists; however, higher cadmium content of the average Japanese diet may be reflected by cadmium concentration in these specimens.     

Trace Metals in Asbestos Carcinogenesis

Concentrations of trace metals judged potentially carcinogenic were determined in samples of amosite, crocidolite, and chrysotiie. The samples included commercial material as shipped, milled and processed material as collected in animal exposure chambers, and International Union Against Cancer (UICC) reference samples. The metals determined were cobalt, nickel, chromium, manganese, and iron. The samples were treated with hydrofluoric acid, the residue taken up with hydrochloric acid, and the determination made by atomic absorption spectrometry. Substantial enrichment of the dusts in nickel and chromium during milling and dissemination was found. Cobalt and nickel content was different from that in UICC samples.     

Immunological Deficiency Associated With Cigarette Smoke Inhalation by Mice

Inhalation of cigarette whole smoke (CWS) or its vapor phase (CVP) significantly impaired immune response capability in mice. Significant immunosuppressive effects on the humoral antibody response to a single antigenic stimulus were evident in animals exposed to smoke for seven days before or two days after administration of antigen. Impairment of the immunological response capability appeared to be temporary, with recovery about 14 days after exposure. Different lengths of exposure prior to antigenic stimulation neither produced an additive impairment of the immunological response nor rendered the experimental animals more tolerant to CWS or CVP. The immunological deficiency was specific to CWS and CVP inhalation rather than to nonspecific debilitating stress factors. The inductive phase was the period of the primary and secondary immune response most sensitive to impairment by exposure to CWS or CVP.     

Subject Index to Volume 3

By monodimensional thin-layer electrophoresis on 5 X 10-cm cellulose layers o-aminolevulinic acid (oAL) is rapidly separated from interfering substances. Detection with a cupric nitrate-Ninhydrin sequence adds specificity and permits detection of as little as 10 ng/lLl of urine. Confirmation can be obtained on two-dimensional chromatograms (5 X 5 em) with the use of either Ninhydrin or a modified MauzeraUasGranick reagent for detection. The quantity of (’)Al can be estimated by visual or densitometric comparison with standards. The method is rapid and inexpensive and is suggested for use in conjunction with the more expensive column chromatographic technique.