Amount and composition of bone minerals in chronic liver disease.

Alterations in bone mineral are a common complication of chronic liver disease. The aim of the current study was to assess bone mineral status in patients with chronic liver disease not treated with corticosteroids and to investigate any possible correlation with the histological stage of liver disease. Bone mineral status in 27 patient with chronic active hepatitis, and 17 with active cirrhosis was compared to that of matched controls. Partial body neutron activation analysis was applied for measuring hand bone phosphorus, single-photon absorptiometry for measuring forearm bone mineral content, and dual-energy x-ray absorptiometry for measuring spinal bone mineral density. These noninvasive measurements were supplemented with data obtained by high resolution radiography and biochemistry. Decreased metacarpal cortical thickness was found in five patients, all in the cirrhotic group. In addition, both mean intact parathyroid hormone and 25-hydroxyvitamin D levels were reduced in this group of patients. The mean values of the quantities assessed by the in vivo techniques in patients in the early stages of the hepatic disease did not differ statistically from those of matched normal controls. On the contrary, these quantities were reduced by 9% in the patients at the late stages relative to controls. In conclusion, only the late stages of liver disease are associated with an increased risk of fractures.

Neutron activation analysis of biological samples at the radiochemistry division of IPEN-CNEN/SP.

Neutron activation analysis is a very useful method for determination of a great number of elements in biological samples. At the Radiochemistry Division of the IPEN-CNEN/SP, this method is being extensively applied to study several materials, such as extracts from medicinal plants, human hair, snake venoms, human lungs, food-stuffs, and corn samples. Both instrumental neutron activation analysis (INAA) and radiochemical neutron activation analysis (RNAA) are used to analyze real samples, as well as biological standard reference materials to evaluate the accuracy and precision of the results.

Determination of selenium in duplicate diets of residents of Pinhel, Portugal, by neutron activation.

A rapid cyclic instrumental neutron activation analysis (CINAA) method has been used to determine the selenium content of 27 duplicate diet samples from each of the 27 districts surrounding Pinhel, Portugal. The accuracy and precision of the CINAA method have been evaluated by analyzing certified reference materials and observed to be within +/- 5-10% for samples containing at least 40 ppb of selenium. The detection limit has been found to vary between 26-42 ppb selenium depending on the sample composition. The average daily dietary intake has been calculated as 37 micrograms of selenium per day.

Determination of inorganic components in Brazilian medicinal plants by neutron activation analysis.

Instrumental neutron activation analysis (INAA) has been applied to multielemental determinations of medicinal extracts obtained from the plants. Cordia Verbenacea DC, Folidago Microglossa DC, and Petiveria Alliacea. Concentrations of the elements Al, Br, Ca, Cl, Co, Cs, Fe, K, La, Mg, Mn, Na, Rb, Sb, and Zn have been determined in dried extracts of these herbs by short and long irradiations under a thermal neutron flux of 10(11)-10(13) n/cm2s in the IEA-R1 nuclear reactor. The NBS Tea Leaves (1572) and NIES Pepperbush (1) reference materials were analyzed simultaneously with the plant extracts. The results obtained in these analyses have shown a good accuracy and reproducibility of the method. The relative errors and the relative standard deviations were less than 10% for most of the elements analyzed.