Radium-226 dose to a boy from playing on mill tailings

Two boys born in September 1949 played on uranium mill tailings from about ages 8 to 12. One of these boys was diagnosed as having leukemia at age 15.5. The 226Ra body burden of the survivor was measured at age 38. The whole-body 226Ra content measured by counting in vivo was 0 +/- 17 Bq and independently by Rn breath analysis as 4.3 +/- 2.1 Bq. At the same time, a control subject with no known exposure to 226Ra, matched in age, height, and weight, was also measured. The whole-body content was estimated as 4 +/- 15 Bq and independently by Rn breath analysis as 5.5 +/- 3.7 Bq. The body burden of the control subject was not significantly different from that of the exposed person. The radiation dose to the marrow-free skeleton assuming a constant 226Ra:Ca ratio since birth was 0.49 and 1.33 mGy at ages 14 and 38, respectively. The radiation dose to the marrow-free skeleton assuming 226Ra intake only between ages 8 to 12 was 1.4 and 2.8 mGy at ages 14 and 38, respectively. The best estimate is the mean of these two estimates: 0.9 and 2.1 mGy at ages 14 and 38, respectively. The alpha-particle dose to the red marrow from 226Ra and its decay products was 0.05 mGy at age 14 and 0.10 mGy at age 38. Since no excess was found for the radium dial painters whose doses were much higher, the induction of leukemia by doses of this magnitude would seem quite unlikely.     

Acute pneumonias in those working with chemical substances that irritate the respiratory tract]

A study was performed of acute pneumonia (AP) morbidity among the workers exposed to respiratory irritation inducing chemical substances, which revealed a marked AP prevalence in these professional groups. A qualitative analysis of the AP cases severity helped to establish some peculiarities of the disease course in workers exposed to minor concentrations of the chemical substances, which should be taken into account in diagnosis, prognosis, treatment and out-patient observation.     

Chick nutritional encephalomalacia and prostanoid formation

Nutritional encephalomalacia (NE) was induced in young chicks using a diet low in vitamin E and containing 8% ethyl esters derived from safflower oil fatty acids (S-E group). The same diet with added alpha-tocopheryl acetate (S+E) failed to produce the pathology, and chicks receiving aerated linseed oil--high in alpha-linolenic acid and low in alpha-tocopherol (L-E)--did not develop symptoms. Formation of metabolites from labeled arachidonic acid (AA) by thrombocytes was similar in the S+E and S-E groups, yielding thromboxane B2 (TXB2) and hydroxy fatty acids as the major products. Collagen-induced thrombocyte aggregation and TXB2 production were not significantly different in the S-E and S+E groups, but aggregation values and TXB2 synthesis were significantly less in the L-E group than in the ataxic S-E chicks. Prostaglandin E2 production by aortal rings was significantly influenced by the diet; S-E yielded the highest value and L-E the lowest. These results show that alpha-linolenic acid causes alterations in the AA metabolism and thrombocyte function in young chicks.     

High propionic acid fermentations and mineral accumulation in the cecum of rats adapted to different levels of inulin

The digestive and metabolic effects of inulin (from chicory) were studied in rats adapted to semipurified diets containing 0, 5, 10 or 20% inulin (wt/wt). Moderate levels of inulin (5-10%) did not significantly affect food intake or body weight gain. Dietary inulin resulted in considerably greater cecal fermentation and a significantly greater intraluminal concentration of propionate (peaking at 58.4 mmol/L). A lower concentration of acetate (42.6 mmol/L) was observed in rats fed 20% inulin. Lactic fermentations were observed in rats fed the 10 or 20% inulin diets. The cecal pool of volatile fatty acids tended to reach a plateau in rats fed diets containing more than 10% inulin (up to 600-700 mumol), but volatile fatty acid absorption was a slightly hyperbolic function of the dietary inulin level. Butyrate absorption was proportionally lower than that of propionate. Inulin-containing diets induced an enlargement of the cecal pool of calcium, phosphate and (to a lesser extent) magnesium. There was also an enhanced absorption of these divalent cations. The cecal pool of bile acids was greater in rats fed inulin, and this oligosaccharide displayed a slight hypocholesterolemic effect, even in rats fed the 5% inulin diet. However, plasma triglycerides were depressed only in rats fed the 20% inulin diet. In conclusion, inulin seems very effective in promoting propionic fermentation and in enhancing the calcium content of the large intestine. However, high levels of inulin (greater than 10%) may affect growth in rats and lead to acidic (pH 5.65) cecal fermentation.     

Dietary fiber and bowel function in tube-fed patients.

In tube-fed patients, dietary fiber is often used to manage constipation/diarrhea. Dietary fiber consists of water-soluble and insoluble plant compounds that are resistant to digestion by small-bowel enzymes but are fermented to varying degrees by colonic bacteria. Many physiologic effects of fiber may be related to the degree of fermentation. Few controlled studies of fiber-containing tube feedings have been performed. These studies have limitations and are nondefinitive as to whether fiber prevents or controls constipation/diarrhea. Constipation in tube-fed patients has not been shown to respond to mixed soluble/insoluble fiber in the few studies performed to date. Likewise, fiber may be of only limited benefit in controlling diarrhea in acute illness because of such factors as stress or medication. Fiber does play a role in maintaining gut integrity in all patients, whether they have diarrhea or not. Fiber may be recommended as part of a standard tube-feeding regimen to help assure gut mucosal integrity but not specifically to treat constipation/diarrhea. Further studies are necessary before the role of fiber in the management of constipation/diarrhea in tube-fed patients is determined.