Homozygous paracentric inversion 12 in a mentally retarded boy: a case report and review of the literature.

A mentally retarded male was found to be homozygous for a paracentric inversion of the long arm of chromosome 12(inv(12)(q21.1q23.2]. His parents, who are first cousins, and his phenotypically normal younger brother are inversion heterozygotes. Homozygous structural rearrangements are discussed and cases of paracentric inversions, including a further nine previously unpublished, are reviewed.

Design and demonstration of a quality assurance program for labor-intensive analytical systems.

An interlaboratory quality assurance program was designed and implemented for the analysis of serum for polychlorinated biphenyls (PCBs) and polybrominated biphenyls (PBBs). The two primary means of quality control were analysis of known and blind quality control samples and analysis of blind duplicate serum samples.

Lake Michigan fish consumption as a source of polychlorinated biphenyls in human cord serum, maternal serum, and milk.

Reported consumption of Lake Michigan sport fish was examined in relation to the levels of polychlorinated biphenyls (PCBs) in biological samples provided by a sample of maternity patients. Fish consumption was correlated with PCB levels in maternal serum and milk but not in cord serum. PCB levels in serum increased with age, but were unrelated to social class, parity, or weight. Women who breast fed consumed as much fish as women who did not and their maternal and cord sera PCB levels were similar.

Temperature-programmed gas chromatographic determination of polychlorinated and polybrominated biphenyls in serum.

An analytical method was developed to quantitate polychlorinated and polybrominated biphenyls (PCBs and PBBs, respectively) in human serum. The method includes denaturation of the proteins in serum, extraction, adsorption chromatography, and gas chromatography with electron capture detection. The coefficients of variation for determining the in vivo bound PCBs and PBBs ranged from 11.7 to 29.8% and 7.1 to 14.0%, respectively. The method is capable of measuring 10 ng PCBs and PBBs/mL in 4 mL serum.

Memory performance of chemical workers exposed to polybrominated biphenyls.

Twenty-five chemical workers who manufactured polybrominated biphenyls (PBB's) were given objective tests of learning and memory. Although this group had high concentrations of PBB's in adipose tissue, mean scores on all memory tests were normal. The PBB concentration was not correlated with memory performance; the most contaminated workers showed no evidence of memory dysfunction.

Interlaboratory comparison for results of analyses for polybrominated biphenyls in human serum.

Four hundred and sixty-six "blind" duplicate serum samples were analyzed for polybrominated biphenyls (PBB) by gas chromatography in two laboratories. As calculated by the regression model of Deming, the correlation coefficient for these 466 samples, whose values ranged from nondetectable amount to 1240 parts per billion was 0.9983. Prior to these analyses, the method was validated in both laboratories by using in vitro and in vivo PBB serum pools.

A study of pesticide residues in Michigan's general population, 1968-70.

A study undertaken in Michigan from August 1968 to April 1970 showed that the county of residence was the most significant factor for determining pesticide residue levels in humans. Occupation, sex, and location of residence were also determined to be associated with blood residue levels. Residues of sigmaDDT and dieldrin were greater in persons 45 years or older. No relationships were detected between blood hemoglobin and blood residue values. In general, as the blood levels for glucose, cholesterol, uric acid, and creatinine increased, so did the levels of pesticide residues. However, when all variables were used, no equation could be developed which would reliably predict a blood residue level given these demographic characteristics.