Stimulation of folliculogenesis in domestic cats with human FSH and LH

Folliculogenesis in response to exogenous stimulation by human urinary follicle stimulating hormone (huFSH) and human menopausal gonadotropin (hMG) was evaluated in the domestic queen (Felis catus). The role of LH and/or FSH in folliculogenesis was examined by measuring concentrations of estradiol 17beta (E(2)) and progesterone (P) in the serum. Additionally, changes in the number and size of follicles from before the administration of exogenous hormones to surgical oocyte collection were monitored. Findings indicated that in queens receiving huFSH or hMG followed by human chorionic gonadotropin (hCG) to induce ovulation, the numbers of follicles from 1 to 3 mm increase with statistical significance (P<0.005) from before the initiation of treatment to surgical collection of oocytes. Although E(2) concentrations in cats receiving hMG increased above baseline by the third exogenous hormone injection, mean E(2) concentrations did not increase in the groups that received both huFSH and hCG, or hCG only, until after the administration of hCG. This suggests that the exogenous administration of LH contained in both hMG and hCG was necessary for E(2) to rise to levels associated with estrus.     

Continuous production of clinical dextran using two-stage reactor

Summary Clinical dextran with desired molecular weight was produced continuously in the two-stage reactor. Cells ofLeuconostoc meseteroides B512F cultivated in the first reactor were transferred to the second reactor where sucrose and primer were added for clinical dextran production. By using this two-stage reactor, the fraction of desired clinical dextran increased significantly when observed with gel permeation chromatography.     

Direct effect of bombesin on pancreatic and gastric growth in suckling rats.

Bombesin stimulates growth of the stomach and pancreas in adult rats. Part of this effect is thought to be through the release of CCK following bombesin treatment. We studied the effect of long term administration of bombesin on the pancreas and stomach in suckling rats and examined the action of bombesin using specific CCK antagonist (CR-1409) and bombesin antagonists (GRP19-26, D-Phe19, Leu26CH2NHCOCH3 = cpd 17; L-686,095-001C002 = cpd 23). Rat pups (7-days-old) were given bombesin (20 micrograms/kg body wt. twice a day) or vehicle (1% gelatin) for 9 days. Bombesin stimulated pancreatic and gastric growth (tissue weight, total protein and DNA content all increased). Pancreatic trypsinogen concentration and content showed a 2-3-fold increase. CR-1409 at 6 mg/kg body wt., a dose that blocked the trophic action of CCK-33 when given to pups at similar ages, did not affect the bombesin-stimulated growth of the pancreas or the increase in trypsinogen level. At 2.4 mg/kg body wt., cpd 17 partially blocked and cpd 23 completely blocked the trophic effect of bombesin on the pancreas and stomach and the increase in trypsinogen level in the pancreas. RU-486, a type II glucocorticoid receptor antagonist, given at a dose sufficient to block the physiological action of glucocorticoid, had no effect on bombesin-stimulated growth of the pancreas. Thus, in vivo, bombesin acts directly on the neonatal pancreas and stomach.     

Staining of argininosuccinate lyase activity in polyacrylamide gel.

A procedure for the direct staining of argininosuccinate lyase activity in polyacrylamide gel is described. The method was based on coupling one of the enzymatic products fumarate with fumarase and malic enzyme catalyzed reactions. Fumarate was first converted to L-malate by fumarase. Malic enzyme then catalyzed the oxidative decarboxylation of L-malate to give CO2 and pyruvate with concomitant reduction of NADP+ to NADPH. Finally the reducing power of NADPH was coupled to phenazine methosulfate and in turn to nitroblue tetrazolium yielding a deeply colored insoluble formazan which may be quantitized or semiquantitized by densitometer.     

Decontamination ofFusarium mycotoxins,nivalenol, deoxynivalenol,and zearalenone,in barley by the polishing process

Korean dehusked and unhusked barley naturally contaminated withFusarium mycotoxins were polished using a Satake Grain Testing Mill. The pearled barley and bran fractions with different degrees of polishing were analyzed for nivalenol (NIV) and deoxynivalenol (DON) by gas chromatography with an electron capture detector, and for zearalenone (ZEN) by high-performance liquid chromatography with a fluorescence detector. NIV was detected in all the pearled barley fractions, but DON and ZEN were not detected in ≥27 % pearled barley fractions from dehusked barley and ≥36% pearled barley fractions from unhusked barley. However, for all degrees of polishing, NIV, DON, and ZEN were detected in bran fractions. The levels of NIV, DON, and ZEN in the bran fractions increased several fold over the original barley. Polishing was effective in removing DON and ZEN from the naturally contaminated barley, but not NIV.     

Possible linkage of the estrogen receptor gene to breast cancer in a family with late-onset disease.

The estrogen-receptor locus is a candidate gene for inherited susceptibility to human breast cancer, particularly among families with later onset, primarily estrogen-receptor-positive tumors. For one extended family with eight patients with late-onset disease, one estrogen-receptor haplotype was consistently coinherited with breast cancer, yielding a +1.85 lod score for linkage at zero recombination. Simulation of this pedigree assuming independent inheritance of breast cancer and estrogen-receptor genotypes led to a lod score greater than or equal to 1.85 only once in 2,000 replicates. We suggest testing linkage of this gene to breast cancer in other families with late-onset disease.     

Plasma membrane Mg(2+)-ATPase of Pachysolen tannophilus: characterization and role in alcohol tolerance.

Following cell fractionation in sucrose density gradients, plasma membrane Mg(2+)-ATPase from Pachysolen tannophilus was studied. The ATPase displayed an apparent Km for ATP of 1.42 mM and was inhibited by high concentrations of Mg2+. The inhibitory effects of ethanol, 1-propanol, 1-butanol, and benzyl alcohol on Mg(2+)-ATPase were evaluated, and the concentration of each alcohol that inhibited ATPase activity by 50% (IC50) was determined. The IC50 decreased as the chain length of the alcohol increased. Moreover, the IC50 for ATPase activity was similar to the IC50 for growth rate, suggesting an association between impaired growth and ATPase inhibition. Almost complete inhibition of ATPase activity occurred at temperatures approaching 60 degrees C, and the optimal temperature was around 44 degrees C for ATPase from both control and ethanol-treated cells. Inclusion of 50 mM MgCl2 or CaCl2 in the medium did not rescue cells from the deleterious effects of ethanol.     

Giardia and Cryptosporidium spp. in filtered drinking water supplies.

Giardia and Cryptosporidium levels were determined by using a combined immunofluorescence test for filtered drinking water samples collected from 66 surface water treatment plants in 14 states and 1 Canadian province. Giardia cysts were detected in 17% of the 83 filtered water effluents. Cryptosporidium oocysts, were observed in 27% of the drinking water samples. Overall, cysts or oocysts were found in 39% of the treated effluent samples. Despite the frequent detection of parasites in drinking water, microscopic observations of the cysts and oocysts suggested that most of the organisms were nonviable. Compliance with the filtration criteria outlined by the Surface Water Treatment Rule of the U.S. Environmental Protection Agency did not ensure that treated water was free of cysts and oocysts. The average plant effluent turbidity for sites which were parasite positive was 0.19 nephelometric turbidity units. Of sites that were positive for Giardia or Cryptosporidium spp., 78% would have been able to meet the turbidity regulations of the Surface Water Temperature Rule. Evaluation of the data by using a risk assessment model developed for Giardia spp. showed that 24% of the utilities examined would not meet a 1/10,000 annual risk of Giardia infection. For cold water conditions (0.5 degree C), 46% of the plants would not achieve the 1/10,000 risk level.     

Cycloheximide increases the thermostability of proteins in Chinese hamster ovary cells

Protein denaturation resulting from temperatures between 42.0 degrees C and 50 degrees C has been observed and implicated as the lethal lesion for hyperthermic cell killing. A logical corollary is that protection against hyperthermic killing requires stabilization of cellular proteins against thermal denaturation. To test this, Chinese hamster ovary cells were treated with the heat protector cycloheximide and then subjected to differential scanning calorimetry to measure protein denaturation. Cycloheximide stabilized proteins that denatured between 42 degrees C and 52 degrees C in control cells by increasing their transition (denaturation) temperature by an average of 1.3 degrees C. In addition, cycloheximide reduced the cytotoxicity of actinomycin D and adriamycin, suggesting that protein stabilization protects cells against stresses other than hyperthermia.     

1-beta-D-ribofuranosyl-1,2,4-triazole-3-carboxamide (ribavirin) and 5-ethynyl-1-beta-D-ribofuranosylimidazole-4-carboxamide (EICAR) markedly potentiate the inhibitory effect of 2',3'-dideoxyinosine on human immunodeficiency virus in peripheral blood lymphocytes.

Ribavirin and EICAR are two antiviral agents that share a similar antiviral activity spectrum and are targeted at inosine 5'-monophosphate (IMP) dehydrogenase. Neither ribavirin nor EICAR inhibit the replication of human immunodeficiency virus (HIV) in peripheral blood lymphocyte cells (PBL) at subtoxic concentrations. However, both compounds markedly potentiate the anti-HIV activity of 2',3'-dideoxyinosine (DDI) in PBL cells without a marked increase of toxicity. Both the increased IMP levels and the decreased guanine nucleotide levels caused by ribavirin and EICAR may be responsible for their potentiating effect on the anti-HIV activity of DDI.