Immunohistochemical studies on peptide- and amine-containing endocrine cells and nerves in the gut and the rectal gland of the ratfish Chimaera monstrosa

Summary The occurrence and distribution of endocrine cells and nerves were immunohistochemically demonstrated in the gut and rectal gland of the ratfish Chimaera monstrosa (Holocephala). The epithelium of the gut mucosa revealed open-type endocrine cells exhibiting immunoreactivity for serotonin (5HT), gastrin/cholecystokinin (CCK), pancreatic polypeptide (PP)/FMRFamide, somatostatin, glucagon, substance P or gastrin-releasing peptide (GRP). The rectum contained a large number of closed-type endocrine cells in the basal layer of its stratified epithelium; the majority contained 5HT- and GRP-like immunoreactivity in the same cytoplasm, whereas others were immunoreactive for substance P. The rectal gland revealed closed-type endocrine cells located in the collecting duct epithelium. Most of these contained substance P-like immunoreactivity, although some reacted either to antibody against somatostatin or against 5HT. Four types of nerves were identified in the gut and the rectal gland. The nerve cells and fibers that were immunoreactive for vasoactive intestinal peptide (VIP) and GRP formed dense plexuses in the lamina propria, submucosa and muscular layer of the gut and rectal gland. A sparse network of gastrin- and 5HT-immunoreactive nerve fibers was found in the mucosa and the muscular layer of the gut. The present study demonstrated for the first time the occurrence of the closed-type endocrine cells in the mucosa of the rectum and rectal gland of the ratfish. These abundant cells presumably secrete 5HT and/or peptides in response to mechanical stimuli in the gut and the rectal gland. The peptide-containing nerves may be involved in the regulation of secretion by the rectal gland.     

The production of pheromone clouds by spraying in the melon fly,Dacus cucurbitae coquillett (Diptera: Tephritidae)

Pheromone clouds sprayed by melon fly males were visually detected by focusing a beam of light at them during dusk when the males were vibrating their wings. The clouds were sprayed to the front, rear and upper sides of the male. We found that special morphological structures are used for spraying the pheromone clouds. When a male melon fly engages in calling behavior, sex pheromone droplets are excreted from his anus. This excretion is wiped off with the tarsus of his hind leg, and then it is deposited on the sexually dimorphic cubital cell hairs on the wing. During wing vibration, the targal bristles on the 3rd abdominal segment, which are peculiar to males, are rubbed against the specialized hairs of the cubital cell. Calling males sprayed clouds of pheromone with these actions. This paper was presented at the 32nd Annual Meeting of the Japanese Society of Applied Entomology and Zoology (Kochi, April, 1988).     

Light and electron microscopic studies on experimental nocardia-toxicosis in mice

An exotoxin (HS-6) produced by Nocardia otitidiscaviarum isolated from certain lesions of cutaneous nocardiosis of a male 82-year-old patient induced severe injuries in the pancreas, liver, stomach, small intestine, heart, thymus and kidney of male ICR mice. Mice given Nocardia-free preparation of HS-6 at a dose of 1 mg/kg of body weight developed several autophagic vacuoles in the pancreas and liver within 20 min after the i.p. injection. Thereafter, the autophagic vacuoles increased in number and size with time. About 24 hr after the administration of HS-6, the liver showed marked accumulation of fat droplets in the cytoplasm of the hepatocytes. Although they contained abundant autophagic vacuoles in the regions of RER, there were no lipomatoses in the acinar cells of the pancreas, those of the chief cells and smooth muscle cells of the stomach, Paneth cells, goblet cells, smooth muscle cells of the small intestine, and plasma cells in the digestive tract. Biochemical examinations revealed that HS-6 had no significant effect on the protein synthesis of reticulocytes. Inoculation of the Nocardia into the mouse peritoneal cavities caused marked granulomatoses in the pancreas, liver and regional lymph nodes, but did not develop autophagic vacuoles in RER regions of these organs.     

A metabolic model for biological phosphorus removal by denitrifying organisms

A metabolic model for biological phosphorus removal under denitrifying conditions has been established. The model is based on previous work with aerobic phosphorus removal. The form of the kinetic equations used is the same as for the aerobic model. The main difference is the value of P/NADH(2) ratio in the electron transport phosphorylation with nitrate (delta(N)). This value was determined independently from batch tests with an enriched culture of denitrifying phosphorus-removing bacteria. The measured delta(N) was approximately 1.0 mol ATP/mol NADH(2). This indicates that the energy production efficiency with nitrate compared to oxygen is approximately 40% lower. These batch tests were also used to identify a proper set of kinetic parameters. The obtained model was subsequently applied for the simulation of cyclic behavior in an anaerobic-anoxic sequencing batch reactor at different biomass retention times. The simulation results showed that the metabolic model can be used successfully for the denitrifying dephosphatation process. The obtained kinetic parameters for denitrifying enrichment cultures, however, deviated from those obtained for the aerobic enrichment cultures. (c) 1996 John Wiley & Sons, Inc.     

Effects of sulfur dioxide and ozone on intact leaves and isolated mesophyll cells of groundnut plants (Arachis hypogaea L.)

Difference between effects of sulfur dioxide (SO₂) and ozone (O₃) on groundnut plants (Arachis hypogaea L.) was studied by use of an exposure system of enzymatically-isolated mesophyll cells. SO₂ inhibited photosynthesis of intact groundnut leaves but induced no visible injury on leaves. SO₂ also inhibited photosynthesis of isolated mesophyll cells but did not kill the cells, suggesting that SO₂ inhibits photosynthesis by attacking rather specifically the photosynthetic apparatus in chloroplasts. O₃ inhibited photosynthesis of intact leaves and at the same time induced visible injury corresponding to the extent of photosynthesis inhibition. O₃ also inhibited photosynthesis of isolated mesophyll cells and killed the cells to the extent corresponding to photosynthesis inhibition, suggesting that O₃ inhibits photosynthesis not directly by attacking the photosynthetic apparatus but indirectly by killing cells. Since the response of intact leaves to each pollutant resembled that of isolated mesophyll cells, the difference between responses of intact leaves to both pollutants may considerably reflect that of mesophyll cells.     

Mouse Offspring Derived from Fetal Ovaries or Reaggregates Which were Cultured and Transplanted into Adult Females

Primordial germ cells (PGCs) and gonia could be promising novel targets and vehicles for manipulation of the mammalian germ line. To make such manipulation a practical possibility, PGCs or gonia must be allowed to produce gametes and offspring after they were isolated from embryos and manipulated in culture. As the first step to develop such research strategy, we obtained offspring from mouse oogonia which were isolated from embryonic ovaries and cultured as dispersed cells before transplantation into female mice as reaggregates.     

Characterization of N omega-phosphoarginine hydrolase from rat liver.

N omega-Phosphoarginine hydrolase from rat liver hydrolyzed N omega-phosphoarginine into arginine and inorganic phosphate, whereas it did not release inorganic phosphate from 19 other phosphorylated compounds containing a N-P bond, an O-P bond or a C-P bond. In addition, it was not able to transfer the phosphoryl moiety from N omega-phosphoarginine to ADP. These results indicated that this enzyme was distinct from both phosphoamidase and arginine kinase. Its properties were as follows: thiol compounds were essential for its activity; it was stimulated by 1.5-2-fold in the presence of 0.001% Lubrol, Tween 20, poly(oxyethylene) 9-lauryl ether and Nonidet P-40, while 0.004% sodium lauryl sulfate inhibited the activity completely; concentrations of sodium molybdate and sodium vanadate necessary for 50% inhibition were 7 microM and 12 microM, respectively; some proteins stimulated the activity, while lysophosphatidic acid, lysophosphatidylinositol, and phosphatidic acid suppressed the activity even in the presence of poly(oxyethylene) 9-lauryl ether.     

Enterocin M-Producing Enterococcus faecium CCM 8558 Demonstrating Probiotic Properties in Horses

The effects of non-authochtonous Enterococcus faecium AL41 = CCM 8558, enterocin M-producing and probiotic strain were tested on the microbiota, phagocytic activity, hydrolytic enzymes, biochemical parameters and dry matter in horses based on its previous benefits demonstrated in other animals. E. faecium CCM 8558 sufficiently colonized the digestive tract of horses. At day 14, its counts reached 2.35 ± 0.70 CFU/g (log 10) on average. The identity of CCM 8558 was confirmed by means of PCR after its re-isolation from horse faeces. The inhibition activity of CCM 8558 was demonstrated against Gram-negative aeromonads, counts of which were significantly reduced (P < 0.001). After 14 days application of CCM 8558, a tendency towards increased phagocytic activity (PA) was measured; PA value was 73.13% ± 8.55 on average at day 0/1; at day 14, it was 75.11 ± 8.66%. Cellulolytic, xylanolytic and pectinolytic activity in horse faeces was significantly increased (P < 0.001) at day 14 (after CCM 8558 application) and amylolytic activity as well (P < 0.01) compared to day 0/1. Inulolytic activity increased with mathematical difference 1.378. Dry matter value reached 20.81 ± 2.29% on average at day 0/1; at day 14, it was 20.77 ± 2.59% (P = 0.9725). Biochemical parameters were influenced mostly in the physiological range. These results achieved after application of CCM 8558 in horses are original, giving us further opportunity to continue these studies, to measure additional parameters and to show the benefits of CCM 8558 application in horses.

     

Late Quaternary Environmental and Human Impacts on the Mitochondrial DNA Diversity of Four Commensal Rodents in Myanmar

Journal of Mammalian Evolution - We addressed the spatiotemporal characteristics of four commensal rodent species occurring in Myanmar in comparison with other areas of the Indo-Malayan region. We...