Bacterial Contamination of Tube-Feeding Formulas

Bacterial cultures were made on tube-feeding formulas provided to 35 unselected adult patients on termination of the infusion. Bacteria were counted and identified using routine procedures. Formulas were classified as nonmanipulated, manipulated, or locally prepared. Medical records were reviewed to determine if diarrhea was present during the period that included 2 days on either side of the sampling day. A significant association was observed between the extent of bacterial contamination and the presence of diarrhea (p = 0.027). Locally prepared and manipulated formulas contained a significantly greater number of organisms when compared to nonmanipulated formulas (χ² = 17.81, p < 0.001). Counts for two baseline and four termination cultures on locally prepared formulas exceeded the acceptable limit for coliform organisms in pasteurized milk according to public health standards. Eight additional cultures on commercial feeding formulas which were presumably sterile initially, exceeded these standards at the end of the administration period. Thus 12 of 35 formulas (34%) would not meet public health standards applicable to pasteurized milk. Use of sterile nonmanipulated formulas in a closed administration set is recommended, along with routine, periodic bacteriologic surveillance of enteral feeding programs. (Journal of Parenteral and Enteral Nutrition 8:673–678, 1984)     

Subcutaneous Fat Necrosis of the Newborn

Subcutaneous fat necrosis of the newborn (SFNN) developed in a 1-week-old black boy. His mother had received numerous medications for eclampsia. Birth was by Caesarean section and complicated by meconium aspiration. There were numerous nodules over the back, buttocks and extremities that yielded a caseous-like material. Microscopically, these nodules showed crystallization and necrosis of the fat. Hypoglycemia, pneumonia, oliguria, thrombocytopenia, seizures and urinary infection were associated with the cutaneous problem and led to a fatal outcome 2 weeks after birth.     

Effect of Fusarochromanone and T-2 Toxin on Articular Chondrocytes in Monolayer Culture in Monolayer Culture

The effect of fusarochromanone and T-2 toxin on DNA synthesisand radio-sulfate incorporation by rabbit articular chondrocyteswas studied in monolayer culture. T-2 toxin reduced DNA morethan 50% at 5 x 10^–9 M; fusarochromanone caused smallbut progressive decrements over a range of 5 x 10^–8 tol0^–6 M. These actions are not specific for chondrocytes.The findings lend no support to the hypothesis that fusarochromanone,at least in unmodified form, is the etiologic agent in Kashin-Beckdisease.     

The guinea pig as a model for predicting photoallergic contact dermatitis

This report describes modifications in the techniques used for both the induction and elicitation of photoallergic contact dermatitis (PACD) in the guinea pig. These changes have improved the reliability of this animal as the model of choice for screening chemicals or products for (heir tendency to produce PACD.
The induction period consists of 15 exposures of the test substance to shoulder skin that has been abraded with a nylon brush rotating at 13,000 rpm. One hour later, the KM site is irradiated with broadband UVA from a source having some irradiance below 320 nm (UVA/b). The animals receive 450 J/cm² of UVA during the three-week induction period. The elicitation (challenge) test is repeated fur two consecutive days. Each day, the test material, if a liquid, is applied to two sties even 30 lo 60 min for 6 h; then one of the sites receives 20 J/cm² of UVA.
These photo-induction and photo-elicitation procedures have demonstrated that low-level concentrations (0.25% range) of 6-melhyl coumarin or musk ambrette will both induce and elicit PACD in the guinea pig. This report adds more evidence that the induction of PACD in the guinea pig is dependent on broadband UVA.     

Leukocytes, Platelets, and Surface Microstructure of Spontaneously Degenerated Porcine Bioprosthetic Valves

The microstructure of 33 spontaneously degenerated porcine bioprosthetic valves was assessed by scanning electron microscopy in order to gather insight regarding the degenerative process. Twenty-four mitral and 9 aortic valves were removed from 32 patients. The duration of insertion was 7.7 +/- 2.4 years (mean +/- SD). All valves showed denudation of endothelial cells and exposure of the subendothelial fibrous tissue. Fibroblastlike cells were occasionally seen. Platelet deposits were observed on 22 of 33 valves (67%). Leukocytes were observed on the surface of 27 of 33 valves (82%). Mononuclear leukocytes were the most common category of cells (66%). Crystalline material was present on the surface of some leukocytes, suggesting that they may serve as a nidus for calcification. Transmission electron microscopy showed leukocytes in the process of phagocytizing collagen fibers. Macrophages, by exerting their scavenger function seem to contribute to destruction of the collagen framework of the valves. Whether the observed lymphocytes and plasma cells reflect an immunological involvement is unclear.     

Induction of delayed hypersensitivity to nitrogen mustard in the guinea-pig

The acquisition of allergic contact dermatitis limits the therapeutic usefulness of topical nitrogen mustard in man. A reproducible experimental model for this syndrome has been provided in the guinea-pig. Guinea-pigs were sensitized to nitrogen mustard (HN₂) by means of the repeated epicutaneous administration of sensitizer to a skin site, and the injection into that site of complete Freund's adjuvant. Application of dimethyl sulphoxide before HN₂ to the sensitization or challenge site facilitated the sensitization and challenge procedures. Positive challenge could be elicited by the intradermal injection of a non-toxic amount of HN₂. The methodology extends to the study of a variety of other sensitizers and potential sensitizers.