Prevention of recurrent acute cystitis by methenamine hippurate: double blind controlled crossover long term study.

In a randomised, double blind, long term, crossover study 1 g twice daily of methenamine hippurate was compared with placebo for its preventive effect on recurrent attacks of acute cystitis. Methenamine hippurate and placebo were interchanged every six months for two years. During one of the years patients took 250 ml extra fluid every morning and evening. Out of 21 enrolled patients, 14 completed the first year and 13 both years of treatment, which permitted the evaluation of 27 patient years. There were 52 episodes of acute cystitis caused by reinfection: 41 occurred during placebo treatment and only 11 during the methenamine hippurate regimen (p less than 0.01). Extra fluid intake did not reduce the incidence of acute cystitis, nor did it reduce the effect of methenamine hippurate. Methenamine hippurate is an effective prophylactic agent against recurrent acute cystitis and has the advantage of not inducing cross resistance to conventional antibiotics.     

Expression of the neurotransmitter-synthesizing enzyme glutamic acid decarboxylase in male germ cells.

The gene encoding glutamic acid decarboxylase (GAD), the key enzyme in the synthesis of the inhibitory neurotransmitter gamma-aminobutyric acid, is shown to be expressed in the testis of several different species. Nucleotide sequence analysis of a cDNA clone isolated from the human testis confirmed the presence of GAD mRNA in the testis. The major GAD mRNA in the testis was 2.5 kilobases. Smaller amounts of a 3.7-kilobase mRNA with the same size as GAD mRNA in the brain was also detected in the testis. In situ hybridization using a GAD-specific probe revealed GAD mRNA expressing spermatocytes and spermatids located in the middle part of rat seminiferous tubules. Studies on the ontogeny of GAD mRNA expression showed low levels of GAD mRNA in testes of prepubertal rats, with increasing levels as sexual maturation is reached, compatible with GAD mRNA expression in germ cells. In agreement with this, fractionation of cells from the rat seminiferous epithelium followed by Northern (RNA) blot analysis showed the highest levels of GAD mRNA associated with spermatocytes and spermatids. Evidence for the presence of GAD protein in the rat testis was obtained from the demonstration of GAD-like immunoreactivity in seminiferous tubules, predominantly at a position where spermatids and spermatozoa are found. Furthermore, GAD-like immunoreactivity was seen in the midpiece of ejaculated human spermatozoa, the part that is responsible for generating energy for spermatozoan motility.     

Molecular genetics of polyamine synthesis in eukaryotic cells

The polyamines putrescine, spermidine and spermine are important cellular constituents involved in the regulation of cell growth and differentiation. Their intracellular levels are regulated by a multitude of mechanisms affecting their synthesis, degradation, uptake and excretion. As a result of the application of molecular biology techniques, some of these mechanisms are presently being unravelled, and are providing a basis for the rational development of novel agents effective against proliferative disorders and various parasitic diseases.     

Detection of nerve growth factor mRNA in the developing chicken embryo

Nerve growth factor (beta NGF) is a protein supporting sympathetic and sensory innervation in the peripheral tissues as well as cholinergic innervation in the brain. A DNA probe derived from a genomic clone coding for chicken NGF was used to study NGF mRNA levels during development. NGF mRNA was detected in the chicken embryo as early as day 3.5 of incubation. The level of NGF mRNA in total embryo increased four-fold until day 8, remained high until day 12, and subsequently decreased. No corresponding peak in NGF mRNA expression was found in heart and brain measured separately. Instead these organs showed increased NGF mRNA levels after hatching. The highest levels of NGF mRNA in the day-8 embryo were found in skin and eye (in particular cornea, but also iris, sclera-choroid and neural retina) suggesting a correlation between sensory innervation and this early peak of NGF expression.     

Primary structure of the hemoglobin α-chain of rose-ringed parakeet (Psittacula krameri)

The structure of the hernoglobin α-chain of Rose-ringed Parakeet was determined by sequence degradations of the intact subunit, the CNBr fragments, and peptides obtained by digestion with staphylococcal Glu-specific protease and trypsin. Using this analysis, the complete α-chain structure of 21 avian species is known, permitting comparisons of the protein structure and of avian relationships. The structure exhibits differences from previously established avian α-chains at a total of 61 positions, five of which have residues unique to those of the parakeet (Ser-12, Gly-65, Ser-67, Ala-121, and Leu-134). The analysis defines hemoglobin variation within an additional avian order (Psittaciformes), demonstrates distant patterns for evaluation of relationships within other avian orders, and lends support to taxonomic conclusions from molecular data.     

Chimeric molecules with multiple neurotrophic activities reveal structural elements determining the specificities of NGF and BDNF.

Nerve growth factor (NGF) and brain-derived neurotrophic factor (BDNF) are two members of a family of neurotrophic factors which show both overlapping and distinct neurotrophic activities. Using site-directed mutagenesis, chimeric molecules were constructed where different combinations of sequences from BDNF replaced the corresponding sequences in NGF. The resulting molecules were transiently expressed in COS cells and conditioned media containing the chimeric proteins were assayed for biological activity in explanted chick sympathetic, spinal and nodose ganglia. Our results show that the biological specificities of the two proteins are obtained by specific combinations of a set of sequences that differ between the two molecules. Some of these combinations allowed us to engineer molecules which display multiple neurotrophic activities recruited from both the NGF and BDNF proteins.     

Effects of gravel size and peat material concentrations on embryo survival and alevin emergence of brown trout,Salmo trutta L.

Embryo survival and alevin emergence pattern of brown trout were studied in simulated redds with different homogeneous gravel sizes and different concentrations of peat material. Optimal survival (95%) occurred in 18 mm gravel and survival decreased with decreasing gravel size. High concentrations (40%) of peat material resulted in low survival (65%). The proportion of premature emerging alevins increased in finer gravels and at high peat concentrations. Premature alevins had a large yolk sac and are probably very vulnerable to predators.     

Comparison of peptidase activities in some fungi pathogenic to arthropods

Peptidases, highly specific toward several synthetic chromogenic peptides, were found in the mycelia of four arthropod pathogenic fungi: Aphanomyces astaci, Beauveria bassiana, Metarrhizium anisopliae, and Paecilomyces farinosus. A. astaci peptidases had high hydrolyzing activities toward most of the peptides, especially those with arginine in the P1 position, while those of B. bassiana and P. farinosus readily hydrolyzed peptides with valine and arginine, as well as proline and tyrosine in the P2 and P1 positions, respectively. The hydrolyzing capacities of M. anisopliae peptidases were similar to A. astaci, but showed lower specific activities. Casein or azocoll was only hydrolyzed by A. astaci peptidases. B. bassiana and M. anisopliae had a very low hydrolyzing capacity toward casein and could not degrade azocoll. P. farinosus had no hydrolyzing activity toward casein or azocoll. Only peptidases from the crayfish pathogen A. astaci could degrade the crayfish cuticle. The peptidase preparations of A. astaci and B. bassiana hydrolyzing MeO-Suc-Arg-Pro-Tyr-pNA or Bz-Phe-Val-Arg-pNA were of the serine type. The possible importance of peptidase activity of arthropod pathogenic fungi in the infection process is discussed.