Isolation and cDNA cloning of ovarian cortical rod protein in kuruma prawn Marsupenaeus japonicus (Crustacea: Decapoda: Penaeidae)

Two cortical rod proteins having molecular weights of 28.6 kDa and 30.5 kDa were isolated from the mature ovary of Marsupenaeus japonicus using gel filtration and reversed-phase HPLC. Analysis of the N-terminal amino acid sequence of the 28.6 kDa molecule revealed that amino acid residues 1-21 corresponded to residues 9-29 of the 30.5 kDa molecule. Examination of homology using BLAST showed that 21 amino acids out of 29 residues of the 28.6 kDa molecule, and 14 out of 29 residues of the 30.5 kDa molecule were identical to that of the ovarian cortical rod proteins of Penaeus semisulcatus. Positive immunohistochemical reaction to antiserum raised against the 28.6 kDa protein was observed on cortical rods forming around the periphery of oocytes at the maturation stages. Western blotting analysis revealed that both the 28.6 kDa and 30.5 kDa molecules stained with the anti-28.6 kDa antiserum. Furthermore, the 28.6 kDa and 30.5 kDa proteins were both glycosylated, as evidenced by positive carbohydrate staining using Concanavalin A and production of positive PAS reaction. These results indicate that the cortical rods are comprised of the 28.6 kDa and 30.5 kDa molecules. We subsequently cloned two full-length cDNAs based on the N-terminal sequences of the 28.6 kDa and 30.5 kDa molecules. The open reading frame of 28.6 kDa and 30.5 kDa encoded 276 amino acid residues. Comparison analysis of the two cDNAs revealed that the location of the processing site and sequence of signal peptides differed, indicating that the two cDNAs are products of two separate genes and encode the 28.6 kDa molecule and 30.5 kDa molecule, respectively. Both proteins possessed one potential N-linked glycosylation site. It is considered that both molecules are components of the cortical rods, forming a jelly layer after fertilization.     

Amphibians as a model system for the investigation of respiratory control development

Recent medical advances have made it possible for babies to survive premature birth at increasingly earlier developmental stages. This population requires costly and sophisticated medical care to address the problems associated with immaturity of the respiratory system. In addition to pulmonary complications, respiratory instability and apnea reflecting immaturity of the respiratory control system are major causes of hospitalization and morbidity in this highly vulnerable population. These medical concerns, combined with the curiosity of physiologists, have contributed to the expansion of research in respiratory neurobiology. While most researchers working in this field commonly use rodents as an animal model, recent research using in vitro brainstem preparation from bullfrogs (Rana catesbeiana) have revealed the technical advantages of this animal model, and shown that the basic principles underlying respiratory control and its ontogeny are very similar between these two groups of vertebrates. The present review highlights the recent advances in the area of research with a focus on intermittent (episodic) breathing and the role of serotonergic and GABAergic modulation of respiratory activity during development.     

A prevalent POLG CAG microsatellite length allele in humans and African great apes

The human nuclear gene for the catalytic subunit of mitochondrial DNA polymerase (POLG) contains within its coding region a CAG microsatellite encoding a polyglutamine repeat. Previous studies demonstrated an association between length variation at this repeat and male infertility, suggesting a mechanism whereby the prevalent (CAG)₁₀ allele, which occurs at a frequency of >80% in different populations, could be maintained by selection. Sequence analysis of the POLG CAG microsatellite region of more than 1000 human chromosomes reveals that virtually all allelic variation at the locus is accounted for by length variation of the CAG repeat. Analysis of POLG from African great apes shows that a prevalent length allele is present in each species, although its exact length is species-specific. In common chimpanzee (Pan troglodytes) a number of different sequence variants contribute to the prevalent length allele, strongly supporting the idea that the length of the POLG microsatellite region, rather than its exact nucleotide or amino acid sequence, is what is maintained. Analysis of POLG in other primates indicates that the repeat has expanded from a shorter, glutamine-rich sequence, present in the common ancestor of Old and New World monkeys.     

The -308 polymorphism in the promoter region of the tumor necrosis factor-alpha (TNF-alpha) gene and ex vivo lipopolysaccharide-induced TNF-alpha expression in patients with aggressive periodontitis and/or type 1 diabetes mellitus

Several single-nucleotide polymorphisms (SNPs) have been identified in the TNF-alpha gene promoter. The transition G-->A at position -308 generates the TNF-alpha1 (G/G) and TNF-alpha2 (G/A or A/A) alleles, where the polymorphic TNF-alpha2 allele is associated with a high, in vitro TNF-alpha expression and an increased susceptibility to diverse illnesses. Here we study the association of the -308 TNF-alpha SNP with the susceptibility for developing aggressive periodontitis (AP), AP combined with type 1 diabetes mellitus (DM) and DM. We also explore the TNF-alpha capability expression and the presence of the -308 polymorphism. For this purpose we recruited 27 individuals with AP (AP+ group), 27 individuals with AP combined with DM (AP+/DM+ group), and 27 individuals with DM without signs of periodontitis upon clinical examination (DM+ group). The control group was comprised of 30 subjects. Genotyping for TNF-alpha promoter was performed by PCR-RFLP analysis. For TNF-alpha expression we used a blood culture system.     

The involvement of sex steroid hormones in downstream and upstream migratory behavior of masu salmon

From May through July when masu salmon, Oncorhynchus masou, commence downstream migration under natural conditions, yearling precocious male masu salmon (resident form) showed higher GSI and plasma levels of testosterone (T) and 11-ketotestosterone (11-KT) in contrast to immature smolts (migratory form). From March through September coinciding with the upstream migration period, 2-year-old male and female adults also showed higher GSI and plasma levels of T, estradiol-17beta (E(2)) 11-KT, 17alpha-hydroxyprogesterone and 17alpha,20beta-dihydroxy-4-pregnene-3-one (DHP). In order to test the effects of steroid hormones on migratory behaviors, silascone tube capsules containing 500 microg of T, E(2), 11-KT, DHP, or a vehicle was implanted into smolts, castrated precocious males, or immature parr, and downstream and upstream behavior were observed in artificial raceways in spring and autumn. Downstream behavior of smolts was inhibited significantly by T, E(2) and 11-KT. Upstream behavior was stimulated by T and 11-KT in castrated precocious males and stimulated by T, E(2) and 11-KT in immature parr. These results indicate that T, E(2) and 11-KT are the factors regulating downstream and upstream migratory behavior. In particular, because of its changing patterns in plasma and significant effects, T, the common precursor hormone of E(2) (female) and 11-KT (male), is considered to play central roles in both types of behavior.     

Acid glycohydrolases in rat spermatocytes, spermatids and spermatozoa: enzyme activities, biosynthesis and immunolocalization

Mammalian sperm acrosomes contain several glycohydrolases that are thought to aid in the dispersion and digestion of vestments surrounding the egg. In this study, we have used multiple approaches to examine the origin of acrosome-associated glycohdyrdolases. Mixed spermatogenic cells, prepared from rat testis, were separated by unit gravity sedimentation. The purified germ cells (spermatocytes [SC], round spermatids [RS], and elongated/condensed spermatids [E/CS]) contained several glycohydrolase activities. Metabolic labeling in the cell culture, immunoprecipitation, and autoradiographic approaches revealed that β-D-galactosidase was synthesized in SC and RS in 88/90 kDa forms which undergo processing in a cell-specific manner. Immunohistochemical approaches demonstrated that the enzyme was localized in Golgi membranes/vesicles, and lysosome-like structures in SC and RS, and forming/formed acrosome of E/CS. Published December 3, 2001     

Benign epithelial gastric polyps--frequency,location, and age and sex distribution

Prospective investigation has been undertaken with the aim to study the frequency, location and age and sex distribution of various histological types of benign gastric epithelial polyps. Histological type--adenomatous, hyperplastic and fundic gland polyps--was diagnosed on the basis of at least three histological samples taken from the polyp. Biopsy samples were also taken from the antrum and the body of the stomach so that gastritis could be graded and classified, and the presence of H. pylori could be determined by histology. All 6,700 patients, who had undergone upper gastrointestinal endoscopy in a one-year period, participated in this study. Among them 42 benign gastric epithelial polyp were found in 31 patients: adenomatous gastric polyps in 7 patients, hyperplastic gastric polyp in 21 and fundic gland polyp in 3 patients. All patients with hyperplastic polyps had chronic active superficial gastritis, whereas most of the patients with adenomatous polyps had a chronic atrophic gastritis with high prevalence of intestinal metaplasia. Among 21 patients with hyperplastic gastric polyps, 16 (76%) patients were positive for H. pylori infection in contrast to only 2 patients (29%) with adenomatous gastric polyps and 1 patient (33%) with fundic gland polyp. Presented data indicates that hyperplastic gastric polyps are the most common and they are associated with the presence of chronic active superficial gastritis and concomitant H. pylori infection. Adenomatous polyps are rarer and they tend to be associated with chronic atrophic gastritis and intestinal metaplasia. Fundic gland polyp is the rarest type of gastric polyps.