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Biomedical subjects

K Hoshina

Publications and source records attributed to K Hoshina.

At least 37 records · Page 2Linked to original sources

Long-term survival of shiga toxin-producing Escherichia coli O26, O111, and O157 in bovine feces.

Cattle are an important reservoir of Shiga toxin-producing Escherichia coli (STEC) O26, O111, and O157. The fate of these pathogens in bovine feces at 5, 15, and 25 degrees C was examined. The feces of a cow naturally infected with STEC O26:H11 and two STEC-free cows were studied. STEC O26, O111, and O157 were inoculated into bovine feces at 10(1), 10(3), and 10(5) CFU/g. All three pathogens survived at 5 and 25 degrees C for 1 to 4 weeks and at 15 degrees C for 1 to 8 weeks when inoculated at the low concentration. On samples inoculated with the middle and high concentrations, O26, O111, and O157 survived at 25 degrees C for 3 to 12 weeks, at 15 degrees C for 1 to 18 weeks, and at 5 degrees C for 2 to 14 weeks, respectively. Therefore, these pathogens can survive in feces for a long time, especially at 15 degrees C. The surprising long-term survival of STEC O26, O111, and O157 in bovine feces shows that such feces are a potential vehicle for transmitting not only O157 but also O26 and O111 to cattle, food, and the environment. Appropriate handling of bovine feces is emphasized.

Aerobiosis↗

[A case of spontaneous hemopneumothorax associated with uncontrolled massive bleeding after inserting thorathic drain].

A 31-year-old man admitted to our hospital complaining of right chest pain. Chest X-ray on admission revealed a collapsed lung and an air fluid line in the right thorax. A chest tube drainage was carried out, but hemorrhagic pleural fluid was drainaged. Forty minutes later, an anemia developed and chest X-ray showed increased massive right pleural collection. Therefore, emergent surgery was performed. An operation under thoracoscopic guidance was converted into thoracotomy because of massive blood clots and fresh bleeding. A bleeding originating from the branch of 1st intercostal artery and a bulla on upper lobes were noted. The artery was coagulated with electrocoutary and ligated using Endo-loop. This artery is not congenital abnormal one but collateral expanded one of which the elastic lamina is thickened. Spontaneous hemopneumothorax is life-threatening, emergent operation should be undergone.

Adult↗

Introduction into Japan of pathogenic Yersinia through imported pork, beef and fowl.

Yersinia was isolated from imported raw meat and fowl products by HeLa cell treatment and conventional KOH-treatment, to obtain information on the origin of pathogenic Yersinia in Japan. Forty-one strains of Yersinia enterocolitica and one strain of Yersinia pseudotuberculosis, serotype 4b were isolated from 38 (3.0%) of 1278 samples of pork, two (0.3%) of 612 samples of beef and two (0.3%) of 615 samples of chicken. Y. enterocolitica isolates belonged to B:4/O:3 (biotype/serotype, 15 strains), B:3/O:3 (two strains) and B:3 variant/O:3 (17 strains) and B:3/O:5.27 (seven strains). The B:4/O:3 which is globally prevalent among humans and animals was isolated from pork samples from Denmark and the US and from beef samples from Australia, the B:3/O:3 from pork samples from Canada, the B:3 variant/O:3 from pork samples from Taiwan and from chicken samples from Thailand, the B:3/O:5.27 from pork samples from the US and Taiwan and Y. pseudotuberculosis, serotype 4b from pork samples from Canada. These findings suggest that pathogenic Y. enterocolitica strains can be introduced into Japan by the import of pork from pig producing countries. The HeLa cell treatment was found to be superior to the conventional method.

Animals↗

Minimization of the number of pregnant women to be treated with preventive procedure against GBS infection by means of antibody measurement. GBS Infection Group.

To study preventive strategies, it is essential to screen pregnant women having group B Streptococcus (GBS) infection in the birth canal. For the purpose of studying preventive measures against this infection, nationwide multicenter research was performed in GBS-carrying pregnant women. Of a total of 10,267 pregnant women, 1860 cases (18.1%) had GBS. The most common serotypes of detected GBS were type NT6 and JM9, followed by type III, type Ia and then type Ib. Type-specific antibody titer was below the cut-off point of 10 units/mL in 30.9% of Ia carriers, 58.5% of Ib carriers, 45.9% of II carriers and 32.9% of III carriers. Fortunately, no neonatal GBS infection occurred during this research. We concluded that 18.1% of studied pregnant women were GBS carriers and one-third of these GBS carriers required preventive procedures with antibody measurement.

Antibodies, Bacterial↗

[Serosurvey for spotted fever group rickettsial infection in vertebrates in Shimane Prefecture].

We carried out a survey for the prevalence of antibodies to the spotted fever group (SFG) rickettsia in vertebrates such as dogs, cattle, deer, and mice in Shimane Prefecture. Rickettsia japonica was employed as antigen in indirect immunofluorescence (IF) tests. The experiment for natural infections using decoy animals was performed in the field of the endemic area. 1. Among 115 street dogs, 18.3% possessed the antibodies against SFG rickettsia, while all of the 8 hunting dogs had the antibodies. 2. Among 234 cattle tested, 17.9% possessed the antibodies. IF titers were 1:40 to 1:160 (mean 1:68). 3. Among 69 wild deer, 92.7% possessed the antibodies ranging between 1:40 and 1:640, which showed the highest IF titers (mean 1:89) among those of the examined vertebrates. 4. The incidence of the antibodies in Apodemus speciosus, Apodemus argenteus and Eothenomys smithi smithi mice were 16.5, 4.3 and 0%, respectively. The incidence of the antibodies against SFG rickettsia in mice captured in the endemic area was significantly higher (22.8%) than that in non-endemicarea (10.4%). Difference in the incidence of antibody-positive mice was also observed within the endemic area. Therefore, we concluded that the infection of mice was restricted to a limited area. 5. No significant rise in IF titers was observed in decoy animals that had been infested with ticks in the endemic area.

Animals↗

An outbreak of group B streptococcus infection in a neonatal nursery and subsequent trial for prophylaxis of nosocomial transmission.

An outbreak of sepsis and meningitis caused by group B streptococcus occurred in three very low birthweight infants. To prevent further nosocomial transmission, immune globulin and ampicillin sodium were administered intravenously to other very low birthweight infants. After this prophylaxis, no other infants were involved in this outbreak. Immuno- and chemoprophylaxis may be considered as procedures to prevent nosocomial infection for very low birthweight infants.

Ampicillin↗

[Detection of carriers of group B streptococci in pregnant women with absorbed charcoal culture. Streptococcal Diseases Study Group].

For prevention of group B streptococcal (GBS) infection in neonates, GBS carriers of pregnant women should be detected. Procedures for detection of carriers were needed to get higher positive rate and to be handled with easy. Urine samples were shown to detect higher rates than vaginal smear samples in pregnant women. GBS in the urine were adsorbed to charcoal granula for easier transporting. These adsorbed charcoal were tested as to whether they could be preserved with different temperatures and days. Urine with 10(1) CFU/ml of GBS added could be detected after 7 days at temperatures of 4, 25, 37, 42 degrees C. The cultures of this procedure with the cultures of urine sediment of pregnant women were compared. Detecting rates of this procedure and urine sediment were 177 (26.2%) and 136 (20.1%) of 676 pregnant women, respectively. These data suggested that adsorbed charcoal culture was useful with higher positive rates for detection of the GBS carriers in pregnant women.

Bacteriological Techniques↗

[Preventive effects of troxipide on a newly developed model of acute gastric mucosal lesion (AGML) induced by ischemia/reperfusion plus ammonia in the rat].

We have developed a unique rat AGML model produced by ischemia/reperfusion plus 0.2% ammonia (I/R.NH3), either treatment which would not induce mucosal injury when used alone. The effects of troxipide and other gastric mucosal defensive drugs were investigated with this I/R.NH3-induced AGML model and other AGML models in rats. The following results were obtained: 1) Like allopurinol, troxipide at 50-200 mg/kg, p.o. dose-dependently prevented I/R.NH3-induced development of AGML and also the ischemia/reperfusion-induced increase of gastric mucosal thiobarbituric acid (TBA)-reactive substances; 2) Troxipide at 10(-6)-10(-4) M, like allopurinol, inhibited concentration-dependently in vitro xanthine oxidase activity in gastric mucosal homogenates; 3) Troxipide at 50-200 mg/kg, p.o. inhibited AGMLs induced by bleeding plus 0.2% ammonia and by 1.0% ammonia alone; and 4) Troxipide and sofalcone were similar in preventing all AGMLs tested and also the increase of mucosal TBA-reactive substances, but somewhat differed from teprenone, cetraxate hydrochloride, azulene plus L-glutamine and sucralfate. These findings suggest that troxipide may inhibit I/R.NH3-induced AGML development by preventing generation of oxygen free radicals and by protecting against mucosal fragility due to reduced energy metabolism from poor blood flow and also against ammonia-induced disruption of the gastric mucosal barrier. Therefore, troxipide may be highly effective for various AGMLs with multifactor involvement.

Acute Disease↗

[Recent status of group B streptococcal (GBS) infection of newborn in Japan].

Group B streptococcal (GBS) infections in neonates have been a leading cause of bacterial infections. In many cases the infected neonates and young infants died or sequelae remained. The trend of cases, risk factors and prognosis of this disease have been the subjects of questionnaires for the past 5 years in Japan. The number of cases has increased year by year. Risk factors including amniotic turbidity, chorioamnionitis, premature rupture of membrane and fever during labor were recognized in 58% of early onset (less than 7 days of age) and in 28% of late onset (7 days and more of age) infant disease. Cases of death and remaining sequelae were 63(20.8%) of 303 early onset, 27(39.1%) of 69 late onset and 90(24.2%) out of a total of 372 cases. These results suggested that strategies for the prevention of GBS infections in the newborn are necessary.

Chorioamnionitis↗

[Inhibitory effects of palonidipine hydrochloride (TC-81) on contractions induced by various vasoconstrictors in rat aorta].

Inhibitions by palonidipine hydrochloride (TC-81), a new Ca entry blocker, of the contractile responses to norepinephrine (NE), serotonin (5-HT), prostaglandin F2 alpha (PGF2 alpha) and U-46619, a thromboxane A2 analog, were investigated in isolated rat aorta strips and compared with the inhibition of the high K+ response. TC-81 and nicardipine inhibited the contractile responses to NE, 5-HT, PGF2 alpha, and U-46619 in a concentration-dependent manner, but their relative inhibitions were less than 50% at 10(-8) M. In a Ca(2+)-free medium, 2-hr pretreatment with TC-81 or nicardipine did not inhibit the contractile responses to various vasoconstrictors, but it inhibited the responses to the addition of Ca. Their inhibitory potencies were less than the inhibition with high K+. Also, the treatment with TC-81 or nicardipine at 10(-7) M did not affect the tissue level of cyclic AMP. These results suggest that in isolated rat aorta, the inhibition by TC-81 of the contractile responses to NE, 5-HT, PGF2 alpha and U-46619 is not due to inhibition of intracellular Ca2+ release or an increase in cyclic AMP; rather, it is due to inhibition of the Ca2+ influx. This inhibitory effect was less than that seen on the high K+ response.

15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5↗

[Effect of palonidipine hydrochloride (TC-81), a novel calcium antagonist, on the canine coronary artery].

The effects of palonidipine hydrochloride [TC-81: (+/-)-3-benzylmethylamino)-2,2-dimethylpropyl methyl 4-(2-fluoro-5-nitrophenyl)-1,4-dihydro-2,6-dimethyl-3,5-pyridinedicarboxylate hydrochloride], a new calcium antagonist, on the coronary artery were studied in dogs. In the isolated canine coronary artery, TC-81 inhibited high K+ (60 mM)-induced contraction in a concentration-dependent manner. The relaxant activity of TC-81 was equal to that of nicardipine and more potent than those of nifedipine and diltiazem. TC-81 increased coronary blood flow in a dose-dependent manner after i.v.-administration in anesthetized open-chest dogs. The activity of TC-81 was equal to that of nifedipine or nicardipine, but the duration of its effect was longer than that of nifedipine or nicardipine. By oral administration in conscious dogs, TC-81 increased coronary blood flow at 0.1 mg/kg or more, and its activity was 10 times more potent than that of nifedipine. These results suggest that TC-81 increases coronary blood flow and is capable of improving the oxygen supply-demand relationship during angina pectoris.

Animals↗

[Effect of palonidipine hydrochloride (TC-81), a new dihydropyridine derivative, on various myocardial ischemic models].

The antianginal effects of palonidipine, a novel 1,4-dihydropyridine derivative, and nifedipine on various myocardial ischemic models were compared. (1) Palonidipine at 0.5 mg/kg, p.o. significantly inhibited vasopressin-induced ST depression of ECG in Donryu rats. This activity was about 5 times more potent than that of nifedipine and was long-lasting. (2) Palonidipine at 1 mg/kg, i.d. significantly inhibited ST depression induced by isoproterenol in Wistar rats. This activity of TC-81 was more potent than that of nifedipine. (3) Palonidipine at 3 micrograms/kg, i.v. produced an increase in regional myocardial tissue blood flow in the ischemic region of chronic coronary artery occluded dogs. (4) In isolated dog coronary artery, palonidipine at a concentration of 10(-10) M or greater inhibited the amplitude of 3,4-DAP-induced cyclic contractions in a concentration-dependent manner. This activity was 10-30 times more potent than that of nifedipine. (5) An intracoronary injection of endothelin (30 pmol/kg) reduced the coronary blood flow, subepicardial tissue blood flow, and subepicardial pH in anesthetized dogs. The ST elevation of ECG over 0.1 mV also occurred in 8 of 10 cases. In all the cases, ventricular extrasystoles were noted, and 9 out of 10 animals died. Pretreatment with palonidipine (3 micrograms/kg, i.v.) inhibited endothelin-induced ischemic changes, with a potency greater than that of nifedipine. These results suggest that palonidipine may be useful for the therapy of angina-pectoris.

Angina Pectoris↗

[Comparison between cultures of urine sediment and of the vagina for detection of carriers of group B Streptococcus (GBS) among pregnant women].

An attempt was made to detect carriers of group B Streptococcus (GBS) among pregnant women by vaginal culture. Reported carrier rates have varied from 3% to 15% and one study has reported that cultures of urine sediment showed a very high positivity rate of 30% among non-pregnant women. In this study, we cultured urine sediment from 110 non-pregnant and 415 pregnant women. Among non-pregnant women, 26% were found to be GBS carriers by culture of urine sediment. Among pregnant women, the carrier rate was 3% by vaginal culture and 15% by culture of urine sediment. The serotypes of cases positive by vaginal vulture were identical with those positive by urine sediment culture. For detection of GBS carriers among pregnant women, culture of urine sediment is easy and reduces the rate of false negativity.

Carrier State↗

Effect of clenbuterol on contractile response in periurethral striated muscle of rabbits.

The effect of clenbuterol, a selective beta 2-adrenoceptor agonist, on isolated periurethral striated muscle preparations from rabbits has been investigated. The periurethral striated muscle produced a contraction in response to field stimulation. An application of clenbuterol resulted in a dose-dependent potentiation of the field stimulation-induced contraction. This potentiation was antagonized by propranolol and was greater than that of isoproterenol, suggesting a beta 2-agonistic action.

Animals↗