Protease-induced hyperactivation of canine spermatozoa associated with disappearance of lectin-binding glycoproteins on their surface

The relationship between the disappearance of glycoproteins from the surface of canine sperm and sperm capacitation was investigated in vitro. The protease (PR) concentration in flush fluids of the uterine horns and oviducts removed from 6 estrous, 5 diestrous, and 5 anestrous bitches was measured with a protease assay kit. Ejaculated sperm collected from 10 dogs were incubated for 4 hr in Eagle's MEM supplemented with 1 or 5 microg/ml PR, or to which no PR had been added (control). The glycoproteins on the surface of the sperm were stained with 4 different FITC-lectins (Con A, PHA-E, PNA, and WGA), and the percentages of hyperactivated (HA-) sperm and acrosome-reacted (AR-) sperm were evaluated. The mean PR concentration (5.95 microg/ml) in the flush fluid from the oviducts of the estrous bitches was significantly higher than in the fluid from their uterine horns (1.00 microg/ml; P<0.01). The PR concentrations of the flush fluids from the uterine horns and oviducts of both the diestrous and anestrous bitches were less than 0.05 microg/ml. Before incubation the acrosomal regions or entire heads of all sperm clearly stained with each FITC-lectin, but the percentages of sperm binding the 4 FITC-lectins decreased after incubation. The percentages of lectin-binding sperm in the MEM containing 5 microg/ml PR were significantly lower than in the control MEM (P<0.05 and 0.01). The mean percentages of motile sperm and HA-sperm after incubation in the MEM with PR were higher than in the control MEM, but there were no differences in the percentages of AR-sperm. The results indicate that HA-movement of sperm is induced by the disappearance of glycoproteins from the surface of canine sperm as a result of the action of PR in the oviductal fluid of estrous bitches.     

Contraceptive effect of proligestone on spotted seals and crossbreeds of spotted seals and harbor seals

Spotted seals (Phoca largha) and related crossbreeds maintained at Kamogawa Sea World breed seasonally from the end of January to middle of March. For contraception in these animals, the effect of a single administration of a contraceptive synthetic luteal hormone for dogs, proligestone (PRG), was investigated. The animals tested were 10 seals aged 4-24 years old, and a total of 35 trials were performed over five years. PRG was administered in 23 trials during January, which was one month before the estimated estrus, and in 12 trials during December of the previous year, which was two months before the estimated estrus. The dose of PRG was 5 mg/kg in 32 trials and 10 mg/kg in 3 trials. The effect of the contraception was judged by the presence or absence of delivery. Among 23 animals treated in January, 2 animals treated with 5 mg/kg PRG became pregnant, but the contraception was successful in the other 21 animals. Contraception was successful in all 12 trials treated with 5 mg/kg PRG in December. Overall, contraception was successful in 94.3% (33/35). Therefore, a single administration of 5 mg/kg PRG in December may be an effective method of contraception for seals.     

Therapeutic effect of aromatase inhibitor in two azoospermic dogs with high plasma estradiol-17beta levels

Two azoospermic dogs with high plasma estradiol-17 beta (E(2)) levels were subcutaneously injected with an aromatase inhibitor (AI), 4-androstene-4-ol-3,17-dione, 2 mg every other day for 4 weeks. Before the AI treatment the plasma E(2) levels of the two dogs (21 and 22 pg/ml, respectively) were higher than those of 2 normal dogs (8.1 and 12.3 pg/ml), and they fell to 11-17 pg/ml between 1 and 4 weeks after the start of AI treatment. The plasma testosterone levels after the start of AI treatment had increased to 2.1-3.1 ng/ml. A small number of sperm were detected in the semen of the two dogs between 3 and 6 weeks after the start of AI treatment. These results indicate that the testicular function of infertile dogs with high plasma E(2) levels can be temporarily improved by AI therapy.     

Myxoid leiomyosarcoma of the gizzard in a broiler chicken

A leiomyosarcoma was found in the gizzard of a 57-day-old female broiler chicken weighing 1.8 kg. Grossly, the tumor mass, 13.0 x 8.5 x 10.0 cm, enveloped the gizzard and had a gelatinous appearance due to the rich production of mucin. Miliary metastatic tumors were noted in the liver. Histopathologically, there was marked production of mucus throughout the tumor tissue, and densely or loosely arranged long spindle-shaped leiomyosarcoma cells proliferated. The tumor cells had a low rate of mitosis, showed slight cellular atypia, and, immunohistochemically, were positive for actin, alpha-smooth muscle actin, and desmin. Electron microscopically, various amounts of microfibrils with focal densities, dense patches, and basal plates were observed.     

Influence of canine cumulus oophorus on homologous sperm motility

Sperm ejaculated by 8 beagle dogs and the cumuli oophori collected from 3 estrous beagle bitches were co-incubated, and penetration of the sperm into cumuli was observed to investigate the influence of cumuli on homologous sperm.The percentages of hyperactivated sperm and acrosome-reacted sperm were calculated after incubation with homogenized cumuli. The hyaluronic acid content of the incubated cumuli was measured, and hyperactivation and the acrosome reaction of the sperm were evaluated in medium containing hyaluronic acid. The mean percentage of hyperactivated sperm (33.0%) and number (3.0) of sperm that had penetrated a cumulus among sperm incubated for 7 hr were significantly higher than the values for sperm incubated for 0.5 hr (P<0.01). Almost all sperm that had penetrated the cumuli had intact acrosome, as though they were hyperactivated. The percentages of motile sperm (77.3%) and hyperactivated sperm (23.6%) after 2 hr incubation in the medium containing homogenized cumuli were significantly higher than in control medium (P<0.01), but there was no difference between cumulus and control media in the percentages of acrosome-reacted sperm. The hyaluronic acid content of a cumulus increased after 24 hr incubation. After 2 and 4 hr of incubation the percentages of hyperactivated sperm in the medium containing hyaluronic acid were significantly higher than in the control medium (P<0.01). These results suggest that canine hyperactivated sperm with intact acrosome can penetrate homologous cumuli and that the sperm are able to pass through the cumulus because the hyperactivated movement is maintained by hyaluronic acid secreted by the cumulus cells.     

Malignant fibrous histiocytoma in a Djungarian hamster

A subcutaneous malignant fibrous histiocytoma (MFH) was observed in the region between the right posterior trunk and right hind limb of a 2-year-old male Djungarian hamster weighing 45 g. Histologically, the tumor consisted of bizarre multinucleated giant cells, histiocytic cells, and fibroblastic cells with a storiform pattern, and was considered to be of the storiform-pleomorphic type of MFH. Severe nuclear atypia with prominent nucleoli and many mitotic figures was also observed. Electron microscopy demonstrated fibroblastic cells and histiocytic cells. The fibroblastic cells were spindle-shaped, and sometimes had an invaginated nucleus. The histiocytic cells were polygonal with an oval or kidney-shaped nucleus. The cytoplasm of both cells contained numerous free ribosomes, small amounts of rough endoplasmic reticulum, and round mitochondria. Tumor cells were immunohistochemically positive for vimentin, and were thought to be of undifferentiated mesenchymal cell origin. This is the first report of spontaneous MFH in a hamster.     

Effect of Japanese catfish Silurus asotus lipid intake on the lipid components of plasma and liver in adult mice

SUMMARY: The effect of Japanese catfish Silurus asotus lipid intake on the lipid metabolism of male adult mice was determined by measuring the total cholesterol, triacylglycerol, phospholipid, and fatty acid content of plasma and liver. Mice were fed diets containing 5% lard, 5% Thai catfish oil, 5% Japanese catfish lipids, or 5% sardine lipids for 4 weeks. The arachidonic acid (20 : 4n-6) content was highest in the livers of mice fed the Japanese catfish lipid diet and docosahexaenoic acid (22 : 6n-3) content was higher in livers of the Japanese catfish lipid and sardine lipid diet groups than those of the lard and Thai catfish diet groups. However, no significant differences were observed in the 22 : 6n-3 levels in either plasma or liver between the Japanese catfish lipid and sardine lipid diet groups. Although the Japanese catfish lipid diet contains, by far, the highest cholesterol content (143 mg/100 g), there was no significant difference in the plasma cholesterol levels between the lard, Thai catfish oil and Japanese catfish lipid diet groups. However, the liver cholesterol levels of mice fed the Japanese catfish lipid diet were lower than those of mice fed the Thai catfish oil diet, and were similar to those of animals fed a sardine lipid diet. These results suggest that Japanese catfish lipids are suitable components of the diet for ingestion of 20 : 4n-6 and 22 : 6n-3, and for decreasing the cholesterol content of liver.     

Pathophysiological features in the brains of female Spontaneously Diabetic Torii (SDT) fatty rats

Diabetes mellitus (DM) and obesity are associated with neurodegenerative diseases such as Alzheimer’s disease and psychiatric disorders such as major depression. In this study, we investigated pathophysiological changes in the brains of female Spontaneously Diabetic Torii (SDT) fatty rats with diabetes and obesity. Brains of Sprague-Dawley (SD), SDT and SDT fatty rats were collected at 58 weeks of age. The parietal cortical thickness was measured and the number of pyramidal cells in the hippocampal cornu ammonis 1 and 3 (CA1 and CA3) and the number of granule cells in the dentate gyrus (DG) regions were counted. The area of glial fibrillary acidic protein (GFAP) positivity in CA1, CA3 and DG regions were measured. The parietal cortical thickness and the number of cells in CA3 and DG regions of SDT and SDT fatty rats did not show obvious changes. On the other hand, in the CA1 region, the number of cells in SDT rats and SDT fatty rats was significantly lower than that in SD rats, and that in SDT fatty rats was significantly lower than that in SDT rats. The GFAP-positive area in SDT fatty rats was significantly reduced compared to that in SD rats only in the DG region. Preliminarily result showed that the expression of S100a9, an inflammation-related gene, was increased in the brains of SDT fatty rats. These results suggest that female SDT fatty rat may exhibit central nervous system diseases due to obesity and DM.     

Bacterial numbers and biomass in leachate and in subsoil of a submerged paddy field

By a leaching experiment with glass columns packed with submerged paddy soils, the relationships among numbers of total bacteria, total Gram-positive bacteria, culturare aerobic bacteria and a amount of bacterial biomass both in the leachate, and in the subsoil after leaching incubation were studied. The leachate from soil columns was collected every 3 d during the 30-d incubation period. The soil columns were packed with plow layer soil samples with and without rice straw (RS) amendment, and the subsoil column was connected to the plow layer soil column without RS. Numbers of total bacteria, culturable aerobic bacteria, and a amount of bacterial biomass in the leachate decreased with the incubation time. There was no correlation between the number of total bacteria in the leachate and the concentration of total organic carbon in the leachate. Bacteria less than 0.1 µsm³ in size predominated in the leachate, especially in that from the plow layer soil column with RS. Percentages of the number of Gram-positive bacteria in the leachate were very low (less than 7% of the total bacterial number), while the percentage in the subsoil after the leaching experiment was in the range of 21–82%. The sum of the number of bacteria percolated from the plow layer soil column with RS during the 30-d period of incubation and the sum of the amount of biomass C were 39 and 77% less than the corresponding values for the bacteria percolated from the plow layer soil column without RS. Percentages of culturable aerobic bacteria among the total bacteria ranged between 2.8 and 37% in the leachate, while less than 0.6% in the subsoil after the leaching experiment.     

Investigation on the contamination of field crops by artificial radioactivities as a result of the H-bomb tests at Bikini Atoll

Introduction

As a result of the H-bomb explosion tests of the U.S.A. in the Southern Pacific Ocean, rain-out in Japan is contaminated considerably by fission products, and field crops also show apparently artificial radioactivities. Many workers are now investigating to clarify degree and regional extent of contamination or sorts of radioactive elements.