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This article brings together data on the proportion of mothers who breastfed their newborn infants, the duration of breastfeeding, infants' intake of breast milk, and the lipid content of breast milk, and presents a simulation model that estimates a distribution of lipid intake from breast milk during the first year of life. The simulation results may be translated into two assumptions useful for public health risk assessments. First, at any given time, approximately 22% of infants under one year are being breastfed; the remaining 78% have no exposure to chemicals via their mothers' breast milk. Second, lipid intake for the nursing infants may be characterized by a normal distribution with a mean of 26.81 g/day and a standard deviation of 7.39 g/day. In combination with measured or estimated concentrations of chemicals in the fat of breast milk, this distribution is suitable for estimating nursing infants' exposures to lipophilic chemicals. These results are based on data for probability and duration of breastfeeding which were standardized to the United States population, and on data for lipid intake from a sample of white, middle- to upper-income, highly educated women living in or near Davis, California.

Our review of the literature on the importance of inhalation and dermal exposures to volatile organic compounds in household water relative to ingestion exposures sought to answer two questions. First, how well do the inhalation and dermal doses predicted by simple models, complex simulations, and measurements agree with one another? And second, what are the implications for the cancer risk from chloroform in household water? The literature yields a coherent and credible range of dose estimates: the ratio of lifetime inhalation dose to lifetime ingestion dose is probably in the range of approximately 0.6 to approximately 1.5, but may be as high as approximately 5.7; and the ratio of lifetime dermal dose to lifetime ingestion dose is probably about approximately 0.3, but may be as high as approximately 1.8. However, because the U.S. Environmental Protection Agency's (EPA's) Cancer Potency Factor (CPF) for inhalation of chloroform is much higher than the CPF for ingestion, the ratios of incremental lifetime cancer risk from inhalation of chloroform to risk from ingestion are much larger than the corresponding ratios for dose. The incremental lifetime cancer risk from chloroform by all three pathways is probably approximately 9 to approximately 21 times the ingestion risk and may be as much as approximately 79 times the ingestion risk. As the EPA reviews the drinking water standard for total trihalomethanes, it is essential that the Agency take account of all exposure pathways in estimating cancer risk.

McKone has recently proposed an innovative two-layer model for dermal uptake of organic chemicals from a soil matrix that explicitly includes variables for properties of the chemical, the soil, the skin, and the exposure. In this note, we investigate the joint time- and loading-dependencies implicit in the model by using MATHEMATICA to find and plot a closed-form function for the uptake fraction for six aromatic hydrocarbons.

A literature review and ten new cases of benign transient hyperphosphatasemia of infancy are presented, with special attention paid to isoenzyme studies. Polyacrylamide gel electrophoresis, heat denaturation, and binding of alkaline phosphatase to anti-human alkaline phosphatases showed that the sources of the elevated alkaline phosphatase levels are normal bone and liver and not the small intestine. The data also suggest that the following criteria be present for a diagnosis of transient hyperphosphatasemia: (1) an age of less than 5 years, (2) variable symptoms, (3) no bone or liver disease noted on physical examination or (4) from laboratory investigations, (5) isoenzyme analysis showing elevations in both bone and liver activity, and (6) a return to normal serum alkaline phosphatase activity values within four months.

Twenty-seven patients requiring massive transfusions were studied prospectively to determine whether administration of stored, modified whole blood induced a primary disorder of hemostasis evidenced by generalized microvascular oozing. Platelet counts fell in proportion to the number of units of blood transfused. In contrast, the levels of factors V and VIII correlated poorly with the units of blood transfused, 85% of the total variation in the levels being due to influences other than transfused blood. Levels of all other clotting factors were unrelated to the number of units of blood given. Eight patients developed abnormal bleeding. The cause appeared to be dilutional thrombocytopenia in five patients, and DIC in three. In six of the eight, bleeding was controlled with platelet concentrates alone. Two patients were given cryoprecipitate also. The most useful laboratory test for predicting abnormal bleeding was the platelet count. Fibrinogen levels should be followed as an aid in the diagnosis of DIC. The BT, PT, and PTT were not helpful in assessing the cause of bleeding, unless they were greater than 1.5 times the control value. We recommend that any patient receiving massive transfusions who develops diffuse microvascular bleeding be given platelet concentrates. Platelet counts as high as 100,000 may be required to control bleeding from surgical wounds. It is not necessary to supplement transfusions of stored, modified whole blood with fresh blood or fresh frozen plasma.

The author develops the hypothesis that women from different population subgroups respond differently to economic and background influences when timing initial childbearing. Data are taken from the National Longitudinal Survey of Labor Market Experience and concern some 5,000 U.S. women followed from 1968 to 1978. "Among all groups examined, age at first birth tends to increase as education levels increase, and married women with spouses present tend to be older than other women at first childbirth. Among whites, all economic influences considered--hourly pay rate, nonmarket income, and work during the year prior to childbearing--have a significant influence in deferring first childbirth, but family background does not. Among blacks, family background plays a significant role in determining age at first childbirth, but only one economic influence--the hourly pay rate--is significant.", (excerpt)

Lyophilized factor VIII concentrates, because of their convenience, are the most commonly used products for providing antihemophilic factor to patients with hemophilia A. Heightened concerns about associated complications indicate that cryoprecipitate usage will increase in the immediate future. We present a protocol for making cryoprecipitate more usable by "prepooling" individual units of cryoprecipitate in an "open" system. Our experience indicates this approach is safe, effective and acceptable to patients, including those on home therapy programs.

The performance of three live attenuated feline parvovirus vaccines licensed for use in the dog was studied. At the end of the primary vaccination course 67 per cent of dogs had inadequate antibody levels (less than or equal to 32) as measured by a haemagglutination inhibition test. Interference by maternal antibody accounted for some of the failures but the fact that there was no significant difference in performance between dogs vaccinated at 12 weeks or 16 weeks of age indicated that maternal antibody was not the only factor.

The authors recently studied two cases of pseudomembranous colitis (PMC) that required surgery and combined them with previously reported cases in the literature, which required surgery to propose guidelines for the surgical management of PMC. A total of 21 patients were studied. Indications for surgery included refractory disease in seven patients, toxic megacolon in 12 patients, and perforation in two patients. Operative management ranged from decompressive cecostomy to total proctocolectomy. The best results were obtained with subtotal colectomy and ileostomy. It is concluded that PMC should be managed surgically in a manner analogous to ulcerative colitis. If there is no improvement after 7 days of aggressive medical management, surgical intervention, ileostomy with subtotal colectomy is indicated to prevent complications. Complications of PMC, toxic megacolon and perforation, should also be managed with ileostomy and subtotal colectomy as simple decompression or segmental resection does nothing to alter the underlying disease process.

Suppressor cell function was studied in 31 patients with primary biliary cirrhosis. Blood mononuclear cells were activated in vitro with suboptimal or optimal concentrations of concanavalin A and suppression of mitogen-induced proliferation or synthesis of anti-mitochondrial antibodies was measured. At suboptimal concentrations of concanavalin A, mean (+/- SE) suppression of proliferation by patients' cells was significantly less than 14 controls (18.7 +/- 5% vs 34.3 +/- 5%; P less than 0.005). The degree of suppressor activity correlated with the clinical disease, i.e., suppression was greater in patients with early than advanced disease. Spontaneous anti-mitochondrial antibody synthesis was not detected in cultures of mononuclear cells from normal subjects nor from patients with negative serum antibody, nor could it be induced by pokeweed mitogen in either group. In contrast, spontaneous anti-mitochondrial antibody synthesis was detected in cultures of 18/23 patients with positive serum antibody and was significantly augmented by pokeweed in 12/18. Anti-mitochondrial antibody synthesis was augmented by 48% (+/- 19) in response to pokeweed and concanavalin A-induced suppression higher (39.4 +/- 7%) in patients with low titer antibody compared to 1.6% (+/- 8) pokeweed augmentation and 5.5 +/- 3% concanavalin A-induced suppression in patients with high titer antibody. These results suggest that some patients with primary biliary cirrhosis have an immunoregulatory defect which expresses itself in part as an inability to regulate autoantibody synthesis.