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The effect of bifenthrin on rainbow trout was assessed based on biochemical, haematological and histopathological examination of fish exposed to Talstar 10 EC pesticide preparation (100 g/L bifenthrin) at a concentration of 14.7 microg/L. There was a significant decrease in plasma ammonia, significant increase in glucose, creatine kinase, alkaline phosphatase and lactate dehydrogenase. Fish showed a significant decrease in mean erythrocyte volume, erythrocyte haemoglobin, and band neutrophil granulocytes. Degeneration of hepatocytes was observed histologically. The bifenthrin-based Talstar 10 EC pesticide preparation was therefore classified as a substance strongly toxic to fish.

Alkaline phosphatases (APases) are commonly used as nonradioactive markers for detecting specific proteins or DNA targets in clinical medicine and molecular biology. However, their applications in the biotechnology industry require thermostability and storage stability. Our preliminary study revealed that APase from Thermus sp. NTU-237 (TsAPase) is thermostable and exhibits high activity. Therefore, it is desirable to establish the optimal conditions for its application. To characterize APase from thermophile Thermus sp. NTU-237 and to evaluate its potential applications. The APase gene of Thermus sp. NTU-237 was cloned and expressed in Escherichia coli. Subsequently, the effects of buffer, glycerol, sodium dodecyl sulfate (SDS), NaCl, and temperature on enzyme activity were studied to establish the optimal conditions for TsAPase assays. In addition, the potential for application of TsAPase was evaluated using the 5-bromo-4-chloro-3-indolyl phosphate/nitro blue tetrazolium (BCIP/NBT) active staining method. Recombinant TsAPase was identified as having a dimeric structure and a molecular mass of 109 kDa. Sequence alignment analysis of known thermophilic APases with TsAPase and E. coli APase revealed that catalytic and binding residues were highly conserved. This finding suggested that the catalytic mechanism of TsAPase is the same as that of other APases. TsAPase activity was inhibited by glycerol and SDS but enhanced by NaCl and Tris-HCl buffer. The kinetic parameters Km, kcat, and Vmax were determined to be 81 µM, 6.08 s-1, and 6.76 U.mg-1, respectively. The optimum temperature of TsAPase was 80 °C, and TsAPase was stable at room temperature for more than 10 days. Moreover, TsAPase could catalyze the dephosphorylation of BCIP and could elicit blue color development by the BCIP/NBT reaction kit at room temperature. These results illustrate that TsAPase has potential for application in medical or basic research.

Hypovitaminosis D and a low calcium intake contribute to increased parathyroid function in elderly persons. Calcium and vitamin D supplements reduce this secondary hyperparathyroidism, but whether such supplements reduce the risk of hip fractures among elderly people is not known. Methods. We studied the effects of supplementation with vitamin D3 (cholecalciferol) and calcium on the frequency of hip fractures and other nonvertebral fractures, identified radiologically, in 3270 healthy ambulatory women (mean [+/- SD] age, 84 +/- 6 years). Each day for 18 months, 1634 women received tricalcium phosphate (containing 1.2 g of elemental calcium) and 20 micrograms (800 IU) of vitamin D3, and 1636 women received a double placebo. We measured serial serum parathyroid hormone and 25-hydroxyvitamin D (25(OH)D) concentrations in 142 women and determined the femoral bone mineral density at base line and after 18 months in 56 women. Results. Among the women who completed the 18-month study, the number of hip fractures was 43 percent lower (P = 0.043) and the total number of nonvertebral fractures was 32 percent lower (P = 0.015) among the women treated with vitamin D3 and calcium than among those who received placebo. The results of analyses according to active treatment and according to intention to treat were similar. In the vitamin D3-calcium group, the mean serum parathyroid hormone concentration had decreased by 44 percent from the base-line value at 18 months (P 0.001) and the serum 25(OH)D concentration had increased by 162 percent over the base-line value (P 0.001). The bone density of the proximal femur increased 2.7 percent in the vitamin D3-calcium group and decreased 4.6 percent in the placebo group (P 0.001). Conclusions. Supplementation with vitamin D3 and calcium reduces the risk of hip fractures and other nonvertebral fractures among elderly women

The susceptibility to five new insecticide mixtures (chlorosan, feroban, cygron, engeo, and kingbo) was studied in the 2nd and 4th instar larvae of the cotton leafworm Spodoptera littoralis. The efficiency and residual effects of these compounds against S. littoralis under field conditions were also investigated. Obtained results revealed that feroban was the most effective compared with the other toxicants, while engeo was the least toxic insecticide in both instars after 2 and 5 days from treatment. Data also indicated that feroban had the longest half-life while engeo recorded the shortest one. Biochemical analysis showed that the tested compounds caused pronounced changes in acetyl cholinesterase and phenol oxidase.

Acute toxicity tests were carried out in order to assess the effect of cypermethrin on rainbow trout. Results of haematological, biochemical and histopathological tissue examinations of control and experimental groups exposed to Alimetrine 10 EM pesticide preparation (active substance 100 g/L of cypermethrin) were compared. An acute semistatical toxicity test lasting 96 h was performed on rainbow trout juveniles. The 96hLC50 value of Alimethrine 10 EM was 31.4 microg/L. In comparison with control animals, the experimental group showed significantly higher values of plasma ammonia, aspartate aminotransferase, lactate dehydrogenase, creatine kinase, and lactate, and significantly lower values of alkaline phosphatase. A significant decrease in counts of developmental forms of myeloid sequence and segmented neutrophile granulocytes was found in the experimental group. Teleangioectasiae of secondary gill lamellae and degeneration of hepatocytes were observed. No histopathological changes were demonstrated in skin, spleen, cranial and caudal kidney tissues. The cypermethrine-based Alimethrinee 10 EM pesticide preparation was classified as a substance strongly toxic for fish.

The purpose of the present study was to assess the effect of kaolin feeding on health status, body weight gain (BWG), course of diarrhoeal infections caused by enterotoxigenic strains of Escherichia coli (ETEC) and the level of mycobacterial contamination in weaned piglets. The testing was performed in two experiments involving 40 weaned piglets at the age of 28 days. In the infection-free experiment, piglets were fed a diet without (C0) or with 1% content of kaolin (K0) for 20 days. Subsequently, all of them were fed the same diet without kaolin supplementation for 39 days. Identical diets were fed during the infection experiment, and moreover, both groups (CI and KI) were orally infected with ETEC (O141:F18ac, STa+) on Day 1 of experiment. The short-term feeding of kaolin to weaned piglets had a significant positive effect on their BWG. During the period of feeding the kaolin-containing diets, BWG in C0 and K0 were 0.20 and 0.29 kg, respectively (P less than 0.05), and in CI and KI 0.13 and 0.19 kg, respectively (P less than 0.05). The protective effect of kaolin on the course of ETEC infection was evident. Colonization and shedding of ETEC by piglets fed the kaolin diet were milder and had a shorter duration in comparison with control animals. The culture examination of pure kaolin and kaolin containing diets for mycobacteria were negative. Potentially pathogenic mycobacteria occurring in the environment were isolated from faeces and tissues of pigs. According to these results, supplementation of diets with 1% kaolin to prevent diarrhoea in piglets and to support their growth in the critical post-weaning period could be recommended.

Background. The use of calcium supplements slows bone loss in the forearm and has a beneficial effect on the axial bone density of women in late menopause whose calcium intake is less than 400 mg per day. However, the effect of a calcium supplement of 1000 mg per day on the axial bone density of postmenopausal women with higher calcium intakes is not known. Methods. We studied 122 normal women at least three years after they had reached menopause who had a mean dietary calcium intake of 750 mg per day. The women were randomly assigned to treatment with either calcium (1000 mg per day) or placebo for two years. The bone mineral density of the total body, lumbar spine, and proximal femur was measured every six months by dual-energy x-ray absorptiometry. Serum and urine indexes of calcium metabolism were measured at base line and after 3, 12, and 24 months. Results. The mean (+/-SE) rate of loss of total-body bone mineral density was reduced by 43 percent in the calcium group (-0.0055 +/- 0.0010 g per square centimeter per year) as compared with the placebo group (-0.0097 +/- 0.0010 g per square centimeter per year, P = 0.005). The rate of loss of bone mineral density was reduced by 35 percent in the legs (P = 0.02), and loss was eliminated in the trunk (P = 0.04). Calcium use was of significant benefit in the lumbar spine (P = 0.04), and in Ward's triangle the rate of loss was reduced by 67 percent (P = 0.04). Calcium supplementation had a similar effect whether dietary calcium intake was above or below the mean value for the group. Serum parathyroid hormone concentrations tended to be lower in the calcium group, as were urinary hydroxyproline excretion and serum alkaline phosphatase concentrations. Conclusions. Calcium supplementation significantly slowed axial and appendicular bone loss in normal postmenopausal women

Juvenile rainbow trouts (between one and two-year-old) were exposed to Sencor 70 WG pesticide product in order to study the toxic effect of its active substance metribuzin (70% in the pesticide). The acute semistatical toxicity test lasted 96 h. The 96hLC50 value of Sencor 70 WG was 89.3 mg/L. In comparison with control animals the experimental group showed significantly lower values of plasma total proteins, triacylglycerols, aspartate aminotransferase, ammonia, calcium, lactate, alkaline phosphatase, erythrocyte count, haematocrit and significantly higher values of erythrocyte haemoglobin. A significant decrease in both the relative and absolute lymphocyte counts and a significant increase in both the relative and absolute counts of neutrophile granulocytes were also recorded. The histopathological examination revealed mild proliferation of goblet cells of the respiratory epithelium of secondary gill lamellae and hyaline degeneration of epithelial cells of the renal tubules of the caudal kidney. This alteration of kidney resulted in hypoproteinaemia, followed by the formation of transudate in the body cavity. The metribuzin-based Sencor WG 70 pesticide product was classified among substances harmful to fish.

We report here that the inward-rectifying potassium channels KAT1 and AKT2 were functionally expressed in K+ uptake-deficient Escherichia coli. Immunological assays showed that KAT1 was translocated into the cell membrane of E. coli. Functional assays suggested that KAT1 was inserted topologically correctly into the cell membrane. In control experiments, the inactive point mutation in KAT1, T256R, did not complement for K+ uptake in E. coli. The inward-rectifying K+ channels of plants share a common hydrophobic domain comprising at least six membrane-spanning segments (S1-S6). The finding that a K+ channel can be expressed in bacteria was further exploited to determine the KAT1 membrane topology by a gene fusion approach using the bacterial reporter enzymes, alkaline phosphatase, which is active only in the periplasm, and beta-galactosidase. The enzyme activity from the alkaline phosphatase and beta-galactosidase fusion plasmid showed that the widely predicted S1, S2, S5, and S6 segments were inserted into the membrane. Although the S3 segment in the alkaline phosphatase fusion protein could not function as an export signal, the replacement of a negatively charged residue inside S3 with a neutral amino acid resulted in an increase in alkaline phosphatase activity, which indicates that the alkaline phosphatase was translocated into the periplasm. For membrane translocation of S3, the neutralization of a negatively charged residue in S3 may be required presumably because of pairing with a positively charged residue of S4. These results revealed that KAT1 has the common six transmembrane-spanning membrane topology that has been predicted for the Shaker superfamily of voltage-dependent K+ channels. Furthermore, the functional complementation of a bacterial K+ uptake mutant in this study is shown to be an alternative expression system for plant K+ channel proteins and a potent tool for their topological analysis