Biomedical subjects

S Ohashi

Publications and source records attributed to S Ohashi.

At least 109 records · Page 6Linked to original sources

PubMed1996

Changes of lymphocyte subpopulations in pigs infected with porcine reproductive and respiratory syndrome (PRRS) virus.

Abnormal changes of T-cell subpopulation were observed in the peripheral blood lymphocytes of pigs infected with porcine reproductive and respiratory syndrome (PRRS) virus. Pigs with naturally occurring PRRS revealed increases in CD2+ and CD8+ cells, and decreases in CD4+ cells and the ratios of CD4+/CD8+ cells. Specific-pathogen-free pigs inoculated with PRRS virus showed remarkable decreases in total lymphocytes, CD4+ and CD2+ cells on Postinoculation Day (PID) 3. The decline of CD4+ cells continued for at least 14 days, while CD2+ cells showed a tendency to increase thereafter. On the other hand,CD8+ cells slightly decreased in number on PID 3, and then increased remarkably; their number was significantly larger on PIDs 28 and 35 than on PID 0. The ratios of CD4+/CD8+ cells were significantly low between PIDs 3 and 28 as compared with PID 0. However, there were no differences in thymocyte subpopulations between infected and non-infected pigs, suggesting that the PRRS virus does not modulate intrathymic T-cell differentiation. In an experiment with peripheral blood mononuclear cell cultures, PRRS virus caused neither alteration of T-cell subpopulations nor cell proliferation, suggesting that the virus is not cytotoxic for CD4+ cells and not mitogenic for CD8+ cells.

Animals↗

PubMed1996

Acceleration of granulation tissue ingrowth by hyaluronic acid in artificial skin.

Hyaluronic acid (HA), which is known to play an important role in wound healing, was incorporated in an artificial skin material and studied for its potential to create a wound bed which would support a skin graft. Collagen sponge based artificial skin was soaked in 0.3% HA in phosphate buffered saline and grafted onto skin defects in rats. Control grafts were soaked in normal saline solution. HA incorporated implants and control implants were simultaneously grafted onto wounds made on either side of the spine. To examine the effect of HA incorporation, the percentage area of cellular tuft infiltration and the number of capillaries present in the graft matrix were evaluated at 7 and 14 days after the operation. At postoperative day 7, there was a statistically significant difference in the number of capillaries in the matrix of the experimental versus the control implants. There was no difference in the percentage area of cellular tuft infiltration. At postoperative day 14, all implants exhibited better ingrowth of granulation tissue than at day 7. The differences between the experimental and control implants were statistically significant with respect to both the percentage area of cellular tuft infiltration and the number of capillaries. It is therefore concluded that in artificial skin HA incorporation accelerates the ingrowth of granulation tissue, making a more suitable graft bed.

Animals↗

PubMed1996

Peroral insertion techniques of self-expanding metal stents for malignant gastric outlet and duodenal stenoses.

Self-expanding metal stents (EMS) have gained widespread popularity for the palliative treatment of various stenoses in blood vessels, biliary ducts, bronchi, and the gastrointestinal tract. Regarding stenoses of the upper gastrointestinal tract, EMS insertion for gastric outlet and duodenal stenoses is considerably more difficult than for esophageal stenoses. We describe a reliable EMS insertion technique for malignant gastric outlet and duodenal stenoses.

Aged↗

PubMed1996

Antibacterial activity of silver ions implanted in SiO2 filler on oral streptococci.

OBJECTIVE: To evaluate the role of silver ions in composite resin dental materials, an in vivo investigation was conducted into the antibacterial effect of SiO2 filler implanted with silver ions on oral streptococci. METHODS. SiO2 filler samples (0.1g) were implanted with silver ions. The effect of the filler with silver ions (Ag+ filler) was tested on oral streptococci bacteria. These bacterial strains had been isolated predominantly from composite resin surfaces. The organisms tested were anaerobically cultured in 5 mL Trypticase Soy Broth containing 0.5 per cent yeast extract at 37 degrees C for 10-12 h. Each bacterial strain was adjusted to a concentration of 1 x 10(6) cells per mL with reduced transport fluid (RTF). Ag+ filler was immersed in 1 mL of RTF and anaerobically incubated 2, 6 and 12 h to study the antibacterial effect. The survival of bacteria was then estimated by culturing on TSBY agar plates. A plate with approximately 100 discrete colonies was chosen from the serial agar cultures, and the number of colonies was counted at each sampling time. RESULTS: The Ag+ filler showed significantly more antibacterial activity than the control filler without silver ions. SIGNIFICANCE: These results indicate that the antibacterial effect found in this study was due to the silver ions released by the Ag+ filler and that it may be useful to add this filler to composite resin dental materials for secondary caries protection.

Anti-Infective Agents, Local↗

PubMed1996

Application of thermosensitive polymers as a new embolic material for intravascular neurosurgery.

Application of thermosensitive polymers as an embolic material for intravascular neurosurgery was investigated. We intended to use thermosensitive polymers to occlude vessels by precipitation in response to body temperature. Copolymers of N-isopropylacrylamide (NIPAM) and N-n-propylacrylamide (NPAM) were selected as thermosensitive polymers. To determine the optimal lower critical soluble temperature (LCST) for the embolic material, we developed an in vitro flow model. In this study the copolymers with an LCST of 24-26 degrees C showed appropriate precipitation. To prove the occlusion of vessels in vivo, we injected the copolymers into a rabbit kidney through a microcatheter. The extent of embolization was judged by angiography and histological examination. An acute toxicity test of the copolymer of NIPAM and NPAM was performed in comparison with that of the NIPAM monomer. The copolymer used in this paper showed no acute toxicity in mice. Water solubility, non-adhesiveness, and non-toxicity are the advantages of the use of thermosensitive polymers as an embolic material. By changing the LCST, various embolic materials can be designed. Based on our results, we believe that the application of thermosensitive polymers as a new embolic material is very promising.

Acrylamides↗

PubMed1996

Mycoplasma hyorhinis infection levels in lungs of piglets with porcine reproductive and respiratory syndrome (PRRS).

The infection levels of Mycoplasma hyorhinis, M. hyopneumoniae and M. hyosynoviae in the lung of piglets were examined in relation to porcine reproductive and respiratory syndrome (PRRS). These animals consisted of 43 PRRS piglets with PRRS, 2 piglets infected with PRRS virus but symptom-free, and 10 control piglets free of PRRS virus and its antibody. M. hyorhinis was isolated from 40 of the 43 PRRS piglets, from 1 of the 2 latent infected piglets and from 3 of the 10 control piglets. The number of M. hyorhinis isolated from the lungs of PRRS piglets was more than 10(5) CFU/g, but those isolated from the latent infected piglets and the control piglets were less than 10(3) CFU/g. In addition to this, Haemophilus parasuis and Pasteurella spp. were frequently isolated from the piglets with PRRS (51.2% and 25.6%, respectively). On the other hand, M. hyopneumoniae was isolated from only 4 of 55 piglets tested, and M. hyosynoviae was not isolated. M. hyorhinis was also detected directly in the lung emulsion samples from almost all the PRRS piglets using a polymerase chain reaction-based method.

Animals↗

PubMed1996

Nested PCR for detection and typing of porcine reproductive and respiratory syndrome (PRRS) virus in pigs.

A nested polymerase chain reaction (PCR) was developed to detect porcine reproductive and respiratory syndrome (PRRS) virus. A common primer set for European and North American type isolates of PRRS virus was designed for reverse transcription PCR, and a specific primer set for each of the 2 type isolates was designed for nested PCR. The PCR that used a specific primer set detected the corresponding type of the virus at a level equivalent to 1 TCID50/100 microliters, but not the other type of isolates. Therefore, the method clearly differentiated the 2 types of virus from each other. The detection of PRRS virus by the nested PCR was as sensitive as virus isolation in cultures of porcine alveolar macrophages from infected pigs at the acute stages, and was more sensitive from pigs at the convalescent stages. The infecting virus type was determined by use of 2 specific primer sets even when virus isolation was negative in naturally infected pigs. It was concluded that the nested PCR is useful for diagnosis and typing of PRRS virus and studies of persistent infection by the virus.

Animals↗

PubMed1996

Effect of growth hormone-releasing factor on the response to insulin of cows during early and late lactation.

The euglycemic clamp technique was used to determine the effect of bovine growth hormone-releasing factor on glucose kinetics and on the response to insulin of 4 dairy cows during early lactation (mean, 35 d postpartum) and of 6 dairy cows during late lactation (mean, 194 d postpartum). Beginning 3 d prior to experiments, cows were injected twice daily with either saline or 2.5 micrograms/kg of growth hormone-releasing factor. On the day of the experiment, saline or the releasing factor (0.0119 microgram/kg per min) was infused into each cow for 5 h. After a basal period, insulin was infused at 1 and then at 6 mU/kg per min; plasma glucose concentrations were maintained at basal concentrations by the infusion of normal glucose. Growth hormone-releasing factor reduced the glucose infusion rate that was required to maintain euglycemia during the insulin infusions during late lactation but had no effect during early lactation. During the insulin infusions of the late lactation experiment only, the rates of glucose appearance, disappearance, and metabolic clearance were lower when plasma growth hormone was elevated. The results demonstrated that elevated concentrations of growth hormone decreased the responsiveness of peripheral tissues to high concentrations of insulin during late lactation but apparently had little effect during early lactation.

Animals↗

PubMed1996

Adherence of oral streptococci to composite resin of varying surface roughness.

The adherence of oral bacteria to composite resins plays an important role in the development of secondary caries. The present study deals with the adherence to composite resin having various surface roughness of S.oralis, which is frequently isolated from composite resin squares attached to maxillary first molars. available commercial resin was used in this experiment. In vitro bacterial adhesion test was carried out under a sucrose independent conditions. The surface roughness values of each specimen ranged between 0.2 micron and 3.0 microns. No relationship was observed between the surface roughness values and bacterial adhesion because S. oralis adhered firmly to the filler particles of all composite resin surfaces.

Bacterial Adhesion↗

PubMed1996

Laparoscopic gastrotomy in intragastric surgery for early gastric cancer: a new technique.

Laparoscopic surgery has been widely applied not only in cholecystectomy but also in gastrointestinal operations. In previous reports the authors proposed their original operative technique, laparoscopic intragastric surgery (LIGS),' in which all trocars and surgical instruments are inserted directly into the gastric lumen to perform the resection of mucosal or' submucosal lesions of the stomach. The purpose of this article is to introduce laparoscopic gastrotomy as a new technique for removing early gastric cancer by LIGS.

Journal Article↗

PubMed1996

[Comparative study of the combined effect of HCFU and dipyridamole (DP) in colorectal carcinoma--TS inhibition rate. Kinki Cooperative Study Group of Chemotherapy for Colorectal Carcinoma].

In the forty-seven medical centers in the Kinki district, a comparative trial was conducted to investigate the enhancement of the efficacy of HCEU due to dipyridamol (DP), which is a biochemical modulator in patients with colorectal cancer who have had a curative resection. The trial consisted of two comparative groups: one group (Group A) received HCFU only for five days before operation and for two years from the second week, and the other group (Group B) was given HCFU + DP for the same trial period as Group A. The total number of patients collected was 653 (Group A: 327 patients; Group B: 326 patients) during the two-year trial period from October, 1991. Thymidylate Synthetase (TS) activity in the primary lesions, which is an index of proximity effect, was measured, and the TS inhibition rate (TSIR) was calculated from the activities. The results showed that the TSIR in the primary lesions for the HCFU + DP group (Group B: 0.33) was significantly higher than that of the HCFU group (Group A: 0.27) (p = 0.0006). There was no increase in the side effects of HCFU due to combined administration with DP. From the above results, the therapy with HCFU + DP is expected to be useful for patients with colorectal cancer who have undergone curative resection.

Adult↗

PubMed1995

Laparoscopic extramucosal myectomy with anterior fundoplication (Dor) for esophageal achalasia using intraoperative manometry.

Laparoscopic extramucosal myectomy with anterior fundoplication according to the Dor technique was performed on a 24-year-old-woman. Intraoperative inflation of a pneumatic balloon made the operative procedures such as extended submucosal dissection quite easy. Intraoperative gastrofiberscopy was useful for confirming that the remaining mucosal layer was not injured after completion of myectomy. Intraoperative manometry confirmed a complete decompression of the high-pressure zone in the lower esophageal sphincter. Complete relief of the symptoms has been recognized for 6 months after operation without any medication. It is considered that these laparoscopic procedures including intraoperative inflation of a pneumatic balloon, gastrofiberscopy, and intraoperative manometry can be used as a standard operation for esophageal achalasia.

Adult↗

PubMed1995

Laparoscopic intraluminal (intragastric) surgery for early gastric cancer. A new concept in laparoscopic surgery.

A new laparoscopic operation for the treatment of mucosal or submucosal gastric lesions has been designed and performed on eight patients. In this procedure, all three trocars are placed in the gastric lumen, penetrating both the abdominal and stomach walls in order to perform a laparoscopic removal of gastric lesions. The operation is then carried out in the gastric lumen with currently available laparoscopic instruments and laparoscopic monitoring. The procedure is easy, safe, and feasible for mucosal or submucosal lesions of the stomach which cannot be treated by gastrofiberscopic technique. In this series, 6 patients with early gastric cancer, 1 with a submucosal leiomyoma, and 1 with giant polyp of the stomach were treated without complications. Since this technique is based on a new concept in laparoscopic surgery, the author has named this intraluminal operation "laparoscopic intragastric surgery."

Adenocarcinoma↗

PubMed1995

Evidence that glucagon stimulates insulin secretion through its own receptor in rats.

Since glucagon-like peptide-1 (7-36) amide (7-37) (GLP-1) has been found to be a potent insulinotropic hormone, it has been postulated that glucagon stimulates insulin secretion from islet beta cells through the GLP-1 receptor. We therefore examined the effects of a GLP-1 receptor antagonist, exendin (9-39) amide, on glucagon- or GLP-1-stimulated insulin release from isolated perfused rat pancreas. When infusion of 100 nmol/l exendin (9-39) amide was started 5 min before that of 1 nmol/l glucagon, the stimulation of insulin release by glucagon was similar to that found in the control situation (preinfusion with vehicle alone). By contrast, when 0.3 nmol/l GLP-1 was used in the same experimental setting, exendin (9-39) amide clearly inhibited insulin release. These results indicate that glucagon stimulates insulin release mainly through glucagon receptors but not GLP-1 receptors on islet beta cells.

Animals↗

PubMed1995

Effect of fasting and growth hormone (GH) administration on GH receptor (GHR) messenger ribonucleic acid (mRNA) and GH-binding protein (GHBP) mRNA levels in male rats.

To elucidate whether GHR and GHBP are coordinately regulated or not, we studied the effect of fasting with or without GH administration on the GHR and GHBP mRNAs in the liver as well as in extrahepatic tissues in rats. Tissues were collected from 7-week-old male rats by decapitation 1,3, and 7 days after the start of fasting. Liver GHR mRNA levels were not affected 1 day after the start of fasting but progressively decreased for the subsequent 3 and 7 days of fasting as compared with those in control rats fed ad libitum. In contrast, liver GHBP mRNA levels significantly rose after 1 day fasting, returned to the control level after 3 days and further reduced after 7 days of fasting. Changes in GHBP mRNA level after fasting were different among the tissues. A transient increase in GHBP mRNA levels was observed in muscle and heart as well as liver, while the GHBP mRNA levels in fat tissues did not change throughout 7 days of fasting. Next, bovine GH(bGH) was administered ip to the fasted rats and control fed rats for either 1 day(100 micrograms [corrected], tid) or 5 days(150 micrograms [corrected], daily). In fed rats, liver GHR mRNA level was significantly increased by 1 day bGH treatment, but after 5 days treatment with bGH it was not different from the level in saline-injected control. Accordingly, net increment of plasma IGF-I was 296.0 ng/ml with 1 day bGH treatment and 234.2 ng/ml with bGH administration for 5 days. In fasted rats, liver GHR mRNA level did not changed after 1 day treatment with bGH, but markedly decreased 5 days after bGH administration. Net increment of plasma IGF-I was slightly reduced to 284 ng/ml with 1 day treatment with bGH, and markedly decreased to 37.0 with bGH administration for 5 days. The effect of GH administration on liver GHBP mRNA level was virtually absent in either fasting or fed state. These findings suggest that GHR and GHBP mRNAs in the liver are expressed in different ways and that expression of GHBP mRNA is differently regulated among tissues.

Animals↗

PubMed1995

PACAP stimulates glucose output from the perfused rat liver.

The effects of PACAP on hepatic glucose metabolism were examined using the flow-through perfusion method for fed rat livers, because some of the glucagon superfamily peptides stimulate hepatic glucose output. Glucose output was significantly stimulated in a dose-dependent manner by more than 1 nM PACAP-27. The potency of its stimulation was equal to that of PACAP-38, greater than that of VIP, and clearly lower than that of glucagon. The cAMP output was also increased significantly by more than 1 nM PACAP-27; however, the degree and profile of cAMP output were not in parallel with those of glucose. Theophylline did not affect these stimulatory effects. On the other hand, in the perfusion experiment with Ca2+ free perfusate, the degrees of increase in glucose output induced by 15 and 40 nM PACAP-27 were significantly reduced. In conclusion, PACAP stimulates glucose output from the perfused rat liver, and Ca2+ rather than cAMP plays an important role in this action as a second messenger.

Animals↗

PubMed1995

The interactive effects of VIP, PHI, GHRH, and SRIF on the release of growth hormone from cultured adenohypophysial cells in cattle.

The effects of hypothalamic peptides [vasoactive intestinal peptide (VIP), peptide histidine isoleucine (PHI), growth hormone (GH)-releasing hormone (GHRH) and somatostatin (SRIF) on GH release from cultured bovine adenohypophysial cells were studied. The cells were incubated for 2 h with the peptides after preincubation for 3.5 days. At doses from 10(-9) to 10(-7)M VIP, the amount of GH released was significantly greater than in the controls (P < 0.05 to P < 0.001). PHI (10(-10 to 10(-7)M did not alter the bovine GH concentration in the media. Incubation with the media containing 10(-7)M GHRH, 10(-7)M VIP, and combined treatment with the VIP plus GHRH increased GH by 186, 40 and 182%, respectively (P < 0.001). Furthermore, although VIP-induced GH release was significantly decreased by SRIF compared with the treatment with VIP alone (P<0.001), the VIP significantly blunted the inhibitory effect of the SRIF on GH release by 24% when compared with that of the SRIF plus GHRH without the VIP (P < 0.05). GH release in combined treatments with VIP, GHRH and SRIF was significantly less than that of the VIP plus GHRH (P < 0.001), but it was significant 29% increase compared with the SRIF plus GHRH (P < 0.05). The combined effects of the VIP (10(-7)M) with GHRH (10(-7), 10(-8) and 10(-10)M significantly induced GH release compared with the controls (P < 0.001), but no additive effect was not observed when compared with the GHRH alone. The results indicate that VIP, but not PHI, acts directly on cultured adenohypophysial cells to induce GH release in cattle.

Animals↗

PubMed1995

[Two cases of sensory neural hearing loss as a manifestation of HIV infection].

In patients with HIV infection, oral and pharyngeal pathology frequently occurs, but there have been no reports on cases of deafness in Japan. Herein, the authors report two cases of sensory neural hearing loss in hemophilia A patients infected with HIV through factor VIII concentrates. Case 1 was a 16-year-old male with hemophilia A. He had been administered factor VIII concentrates starting at 6 months after birth. At 8 years of age, HIV antibodies were positive. He was diagnosed as having AIDS after suffering from pneumocystis carinii. He complained of right otalgia and slight vertigo during treatment for a relapse of the pneumocystis carinii. He underwent otological examinations at our department. The right tympanic membrane showed opacification and serous otorrhea was noted. Acute otitis media was diagnosed and tympanotomy was conducted. Afterwards, the right tympanic membrane developed a large perforation and sensory neural hearing loss occurred. Case 2 was a 49-year-old male with hemophilia A. He had been administered factor VIII concentrates from the age of 23 years. At 48 years of age, HIV antibodies were positive. The patient complained of sudden deafness in the right ear and slight vertigo. He underwent otological examinations at our department. The tympanic membrane was normal bilaterally, but sensory neural hearing loss was found in the right ear. It was presumed that acute otitis media directly involving the inner ear had caused a perceptive disorder in case 1 while a pattern of sudden onset of deafness was apparent in case 2.

Acquired Immunodeficiency Syndrome↗