Mortality studies of machining fluid exposure in the automobile industry III: A case-control study of larynx cancer

A case-control study of larynx cancer was conducted within a cohort of automobile workers exposed to metal working fluids, commonly referred to as machining fluids (MF). Results are based on 108 cases of larynx cancer and 5:1 matched controls. Risks associated with specific types of MF, as well as specific components of the fluids were evaluated. Based on a retrospective exposure assessment, lifetime exposures to straight and soluble fluids, grinding particulate, biocides, selected metals, sulfur, and chlorine were examined. Exposure to asbestos and acid mists at two of the three study sites was also characterized. Results suggest that straight mineral oils are associated with almost a two-fold excess in larynx cancer risk. There was also evidence of an association with elemental sulfur, commonly added to straight MF to improve the integrity of the materials under extreme pressure and heat. It is not clear whether sulfur is causally related to an excess relative risk of larynx cancer or whether the observed association is the result of unmeasured confounding by another contaminant or process feature. For example, the high stress operations that require MF enriched with sulfur are also more likely to produce polycyclic aromatic hydrocarbons (PAHs) during the process. Thus, the observed association with sulfur may be due to an association with PAH. The finding of excess risk of laryngeal cancer associated with MF is consistent with several previous reports in the literature. This is the first study, however, to distinguish straight mineral oils from other types of MF. Based on these findings, a general reduction in concentrations of straight mineral oil particulate in occupational environments would be prudent.     

Cognitive impairment of acute onset in the Consortium to Investigate Vascular Impairment of Cognition (CIVIC) study: occurrence, correlates, and outcomes.

OBJECTIVE: Having demonstrated that dementia of acute onset represents a distinct syndrome with distinct outcomes, the authors investigated whether similar attributes describe cognitive impairment of acute onset (CIAO). METHODS: The authors conducted a secondary analysis of the Consortium to Investigate Vascular Impairment of Cognition study. RESULTS: Ninety patients met our criteria for CIAO. Compared with cognitive impairment of gradual onset, CIAO was associated with vascular features (odds ratio [OR]: 12.3, 95% confidence interval [CI]: 3.2-47.9), dementias other than Alzheimer disease (OR: 6.5, 95% CI: 2.1-20.8), and decreased survival (hazard ratio: 2.8, 95% CI: 1.6-4.6). CONCLUSIONS: Patients with CIAO are clinically identifiable and have distinct outcomes.     

The stromal cell line S17 supports the growth of lipopolysaccharide-stimulated CBA/N spleen cell colonies in vitro.

The expression of an X-linked defect in the CBA/N strain of mice has been found to result in a number of immune abnormalities. These include low responsiveness to antigens and a greatly reduced ability to respond to many of the common B cell mitogens. An in vitro manifestation of this condition is the virtual inability of CBA/N B cells to form colonies in lipopolysaccharide (LPS)-containing semisolid agar cultures. In this report we show evidence that the colony-forming ability of CBA/N spleen cells can be effectively restored by the bone marrow stromal-derived cell line S17. Spleen cells from 4-5-week-old homozygous CBA/N female mice were grown in double-layer agar cultures containing S17 feeder layers. Control cultures contained the fibroblast-like cell line 95.17 or were treated with medium alone. It was found that at an input cell concentration of 10(4) cells per plate, CBA/N colony formation was increased from a frequency of approximately 1 in 5,000 to 1 in 50 total splenic cells. Studies with purified surface immunoglobulin-positive cells indicate the direct involvement of S17 in this process. The CBA/N colonies formed were dependent on the presence of a mitogen (LPS) and secreted detectable amounts of IgM. Major implications of these findings and the application of this assay system to study the CBA/N defect have been discussed.     

CURRENT CONCEPTS IN INFANT NUTRITION

Nutritional needs vary during the first year of life according to the infant's individualized pattern of growth and amount of physical activity. After delivery, the infant must make many physiologic adjustments, develop immunologic defenses, and take in adequate nutrients for survival. The type and consistency of foods change as the gastrointestinal system matures and becomes able to metabolize the components and excrete the needed metabolites of increasingly complex foods. The recommended dietary allowance for infancy is based on the amount of nutrients provided to healthy infants in human milk during the first six months of life and on the consumption of formula and increasing amounts of solid food during the second six months. The introduction of solid foods should parallel the developmental changes that occur within the central nervous system throughout the first year; these provide a level of readiness for the infant to manage foods of various textures from full liquid to soft. Even though significant technologic advances have led to changes in the way infants can be fed, human milk is still the optimal choice. Most women can be encouraged to breast-feed regardless of their own nutritional status or dietary intake. Contraindications can be managed on an individual basis. If women do not elect to breast-feed, suitable commercial formulas are available. The important issue in feeding is that of providing a variety of appropriately prepared foods offered in a nonjudgmental atmosphere so that the foundation is laid for the development of good food habits.