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Biomedical subjects

R Wada

Publications and source records attributed to R Wada.

At least 127 records · Page 7Linked to original sources
PubMed1991

Effect of viral inoculum size on appearance of clinical signs in equine Getah virus infection.

A study was performed to examine the effect of viral inoculum size on the appearance of clinical signs in equine Getah virus (GV) infection by intramuscular inoculation with 10(1.3) to 10(6.3) TCID50 of the MI-110 strain in 6 experimental horses. When inoculated with more than 10(3.3) TCID50 of the virus, every horse developed pyrexia, edema in the hind legs, serous nasal discharge, lymphopenia and viremia in the relatively early stage of disease. On the other hand, enlargement of the submandibular lymph node was observed only in horses inoculated with 10(5.3) and 10(6.3) TCID50 of the virus, while typical eruptions were developed in every horse inoculated with 10(4.3) TCID50 or less. These results demonstrated that the appearance of clinical signs in equine GV infection was dependent on viral inoculum size. Besides, it was assumed to be rare chance that eruptions and enlargement of the submandibular lymph node were developed simultaneously in a horse.

Alphavirus↗
PubMed1991

Intranasal infection of Getah virus in experimental horses.

Aerosol transmission in equine Getah virus (GV) infection was examined by intranasal inoculation with 10(3.0) to 10(7.0) TCID50 of the MI-110 strain in 7 experimental horses. The establishment of intranasal infection of GV was confirmed in all these horses by detecting serum neutralizing antibody against the MI-110 strain. Horses inoculated with more than 10(4.0) TCID50 of the virus manifested mild pyrexia, eruptions, serous nasal discharge, lymphopenia or monocytosis. Viremia ranging from 10(1.0) to 10(3.5) TCID50/0.2 ml occurred in horses inoculated with 10(5.0) TCID50, or more. Virus recovery from the nasal cavity was observed only in horses inoculated with 10(7.0) TCID50, and the viral titers recorded were 10(3.0) TICD50/ml or less. From these results, it is assumed that GV disseminated from the nasal cavity of naturally infected horses, except for intranasal infection with a lot of the virus, is probably very low in titer. So it seems to be rare that GV in natural cycles is spread from horse to horse by aerosol transmission.

Aerosols↗
PubMed1991

A bioabsorbable delivery system for antibiotic treatment of osteomyelitis. The use of lactic acid oligomer as a carrier.

We prepared a composite of D,L-lactic acid oligomer and dideoxykanamycin B for use as a biodegradable antibiotic delivery system with sustained effect. The composite was implanted in the distal portion of the rabbit femur, and the effective concentration of the antibiotic was measured in the cortex, the cancellous bone, and the bone marrow. In all bone tissues around the implant, the concentration of antibiotic exceeded the minimum inhibitory concentration for the common causative organisms of osteomyelitis for six weeks. Most of the implant material had been absorbed and the bone marrow had been repaired to a nearly normal state within nine weeks of implantation. The implant caused no systemic side effects, and it is likely to prove clinically useful as a drug delivery system for treating chronic osteomyelitis.

Absorption↗
PubMed1991

Treatment of malignant pleural effusions with doxorubicin hydrochloride-containing poly(L-lactic acid) microspheres.

For the treatment of malignant pleural effusions, we prepared doxorubicin hydrochloride (Adriamycin)-containing poly(L-lactic acid) microspheres (ADR-MS). In vitro, 50 percent and 100 percent release times of ADR from ADR-MS were 6.3 and 20 days, respectively. After intrapleural administration of ADR-MS for seven patients at an ADR dose of 40 mg, ADR was detected in the effusions for more than two weeks; however, ADR concentrations in serum were very small, consistent with minimal transpleural absorption of ADR. These results indicated the slow release of ADR into the pleural cavity. Furthermore, the amount of drained ADR was less than a few percent of the administered dose. In some cases, malignant cells in the effusion disappeared after the treatment. No complications related to the procedure occurred, and the patients developed no systemic symptoms. One patient died after four months, and the other six patients are alive after 21 to 31 months without reaccumulation of the effusion. The local administration of ADR-MS produces a localized high and systemic low concentration of ADR, which could potentially improve the patient's quality of life.

Aged↗
PubMed1991

[A study on BrdU labelling index of gastric cancer using in vitro labelling method].

In order to reveal the effect of environmental factors to BromodeoxyUridine labelling index (BrdU L.I.) and its usefulness as clinicopathological information, 522 specimens obtained from 121 lesions of gastric cancer were studied. Five hundred twenty two specimens in which BrdU had been incorporated using an in vitro labelling method were divided into 3 groups according to their degree of necrosis and cell infiltration. The average L.I. of the specimens with no or slight necrosis was 23.3 +/- 8.7%, medium, 14.2 +/- 10.0%, and severe necrosis, 6.6 +/- 3.8%, with no or slight cell infiltration, 25.3 +/- 9.5%, medium, 21.0 +/- 7.1%, and severe cell infiltration, 21.2 +/- 6.1%, therefore L.I. correlated to necrosis and cell infiltration. Representative values for each lesion were adopted and compared using 3 methods. In method A, a representative value of the L.I. for each lesion was chosen using all biopsy specimens, method B using specimens without necrosis, and method C, specimens without necrosis and cell infiltration. L.I. correlated to stage and the lymphnode metastasis only using methods, B and C and more strictly using method C. Necrosis and cell infiltration should be considered in adopting a representative value of the L.I. for each lesion. Method C is considered to be a best among the three studied, and the L.I. of gastric cancer may be considered a clinicopathological marker.

Biopsy↗
PubMed1991

[Studies of morphometric analysis and cell cycle of gastric epithelia of rat administered minimal mixed bile acids].

The gastric epithelia of the rat after administrated with the minimal mixed bile acids and lysozyme for 9-weeks were studied using morphometric analysis and anti-Bromodeoxyuridine staining immunohistochemistry. Our results show that the atrophic changes and increased anti-BrdU antibody staining positive and mitotic cells of the pyloric glands area in the group administration only bile acids. Lysozyme inhibited bile acids activation on these changes of this area.

Animals↗
PubMed1991

[Studies on the nontuberculous lung mycobacteriosis in Japan. (Report of the study in the year 1987 and 1988 of the Mycobacteriosis Research Group of the Japanese National Chest Hospitals)--pulmonary infection caused by Mycobacterium kansasii has begun to appear in all over Japan including north Japan Hokkaido].

UNLABELLED: In this study, the Mycobacteriosis Research Group of the Japanese National Chest Hospitals (MRG) presents the reports of study years 1987 and 1988. As reported previously**, pulmonary infection caused by Mycobacterium kansasii occurred principally in South-West Japan (prefectures South-West of Tokyo) and did not appear in North Japan. However, this disease appeared in 1987 and 1988 in Hokkaido (Sapporo Hospital). Accordingly, we may say the disease occurs all over Japan. This is a noteworthy finding newly recognized in the study years. The prevalence rate of nontuberculous lung mycobacteriosis was determined as 2.92 or 2.78 in 1987 and as 2.02 or 1.91 in 1988 per 100,000 population per year. The estimated rates based on the ratio of nontuberculous lung mycobacteriosis against active lung tuberculosis and based on the ratio of nontuberculous lung mycobacteriosis against culture-positive lung tuberculosis well agreed with each other. COMMENT: In this country, chest physicians customarily report their cases of nontuberculous mycobacteriosis including lung tuberculosis, because the payment of treatment for patients with tuberculosis is free. Because of this custom, tuberculosis statistics surely contain cases of nontuberculous mycobacteriosis. Caution about this has been paid in calculating the prevalence rate. From the study year 1987, the MRG chairman moved from Michio Tsukamura, The National Chubu Hospital, to Nobuhiko Kita, The National Kinki Chuo Hospital.

Humans↗
PubMed1991

[Five cases of tuberculosis occurring in an accounting office during 5-year period].

Five cases of pulmonary tuberculosis occurred in an accounting office during 5-year period. Patients 1 and 2 were hospitalized in January and March respectively in 1984. Patients 3 and 4 were found to have abnormal shadows in 1987. Patient 5 was admitted to our hospital in July, 1988. Patients 1 and 2 showed a similar pattern of drug resistance. The desk of Patient 3 was located in front of the desk of Patient 1. Retrospective review of chest X-ray film of Patient 3 taken two years before admission revealed that active contagious tuberculosis had been misdiagnosed as inactive type, resulting in delayed treatment. Patients 4 and 5 worked near to Patient 3 for the past two years. PPD skin test was carried out on 47 workers in the same room and other rooms as well. The distribution of maximum diameters of erythema for workers in the same room did not show a bimodal distribution, but the mean diameter (30.6 +/- 16.4 mm) was larger than that (22.3 +/- 17.2 mm) for workers in other rooms. Preventive administration of Isonicotinic acid hydrazide (INH) was made for 10 workers. These observations suggest that routine chest X-ray film should be carefully checked, and PPD skin test should be performed to those at risk of tuberculosis infection.

Accounting↗
PubMed1991

Microspheres of biodegradable polymers as a drug-delivery system in the vitreous.

Microspheres of biodegradable polymers were evaluated as a potential controlled-release drug-delivery system in the vitreous. The microspheres were prepared with polymers of poly(lactic acid) or copolymers of glycolic acid and lactic acid. The release of 5-fluorouracil (5-FU) from the microspheres was studied in vitro. Poly(lactic acid) microspheres released 70-85% of total 5-FU over 7 days. Microspheres of polymers with a smaller molecular weight released the drug more rapidly. Copolymer microspheres released 98% of 5-FU over 2 days. The rate of drug release was controllable by changing the molecular weight of the polymers or using a matrix of copolymer. The intravitreal kinetics of the microspheres were studied in ten rabbits in vivo. A suspension of microspheres was injected into the vitreous cavity of five normal eyes and five vitrectomized eyes. By 48 +/- 5.2 days after injection, the microspheres disappeared from the vitreous cavity in the five normal eyes. Clearance from the vitreous cavity was accelerated in the five rabbits that underwent vitrectomy (14 +/- 2.4 days; P less than 0.001). No difference was found in the b waves of electroretinograms before and after injection of the microspheres. The histologic study showed no abnormal findings as a result of the injection. These results suggested that microspheres of biodegradable polymers may be a potential delivery system for the controlled release of drugs in the vitreous.

Animals↗
PubMed1991

[Chemotherapeutic evaluation of pulmonary tuberculosis patients with a complication of hepatic dysfunction].

A retrospective study on the evaluation of antituberculous drugs for patients with hepatic dysfunction was undertaken to clarify treatment regimens. The values of GOT, GPT and T. Bil were used as indicators of liver function, and the "deterioration" in the liver function was defined as a level greater than 1.5 times the initial value. Of total 538 cases of active pulmonary tuberculosis, 103 cases (19.1%) had abnormalities in liver functions before chemotherapy, and 21 of 103 cases showed the deterioration in their liver functions during chemotherapy. There was little relationship between the initial status of liver functions and the incidence of their deteriorations after chemotherapy. Nine of 21 cases did not exceed the 3 times of normal ranges of liver functions. These nine cases could tolerate the same regimens of chemotherapy, and showed satisfactory clinical responses to chemotherapy with two exceptions: one died of tuberculosis and the other cerebrovascular disease. On the other hand, of 12 cases with elevated values of hepatic function greater than 3 times the normal limits, 6 cases discontinued chemotherapy. One case, however, died of hepatic failure related to chronic active hepatitis. Eight of 12 cases showed the rapid improvement of liver dysfunctions. These results suggest that antituberculous drugs are acceptable to patients with hepatic dysfunction as long as the elevations of GOT, GPT and T. Bil stay within 3 times of normal limits. Further chemotherapy could be continued under careful monitoring of liver functions even if the cases exhibit elevated levels of liver functions greater than 3 times the normal ranges.

Adult↗
PubMed1990

Lactic acid oligomer microspheres containing hydrophilic drugs.

A new method was developed for preparation of biodegradable lactic acid oligomer microspheres containing hydrophilic drugs. The microspheres were obtained by removal of solvent from an O/O (oil-in-oil) emulsion through evaporation. The solvent used for the dispersed phase solution was an acetonitrile: water mixture, while the continuous phase medium was cottonseed oil. Doxorubicin hydrochloride (ADR) and insulin were successfully entrapped in the microspheres with high trapping efficiencies of 80 to 90%, and their release profiles were not accompanied with the significant burst effect. The release rate of the drugs from the microspheres was greatly affected by the initial loading of the drugs and the molecular weight of the lactic acid oligomer.

Aclarubicin↗
PubMed1990

Induction of immune response and protection from equine viral arteritis (EVA) by formalin inactivated-virus vaccine for EVA in horses.

Thirty-nine horses included 3 pregnant mares were examined by inoculating with formalin inactivated-virus vaccine for EVA. Antibody response of horses after one dose vaccination was somewhat poor and 50% effective inoculum dose of the vaccine should be included 10(8.4) pfu of virus before inactivation. After 2 doses given at an interval of 4 weeks, the horses developed such high titer of SN antibody as up to 1:5,120. The SN titer declined rather rapidly, but supplemental administration of the vaccine at an interval of more than 2 months elicited a prompt antibody response and SN titers persisted as 1:80 to 1:320 at 6 months after the administration. Therefore, supplemental administration of the vaccine as booster every 6 months or 1 year would be capable of maintaining high titer of SN antibody. The inactivated-virus vaccine prevented horses from clinical disease of EVA and protected pregnant mares from abortion by challenge exposure with virulent virus. Fifty percent protective dose in SN titer of 1:43 was confirmed by clinical signs and viremia.

Animals↗
PubMed1990

[Intravitreal drug delivery by microspheres of biodegradable polymers].

We evaluated the efficacy of microspheres of biodegradable polymers as a slow releasing drug delivery system in the vitreous body. Microspheres containing 5-FU were prepared with polymers of poly-(lactic acid) or copolymers of glycolic acid and lactic acid. The release of the drug was studied in vitro. Poly-(lactic acid) microspheres released 5-FU for 7 days. The intravitreal kinetics of the microspheres was studied in rabbits in vivo. The microspheres disappeared from the vitreous cavity of normal eyes by 48 +/- 5 days after injection. Disappearance was accelerated from the vitreous cavity of vitrectomized rabbits (14 +/- 2 days, p less than 10(-6)). No abnormality was found on electroretinographic or histological examinations after microspheres injection. These results suggested that microspheres of biodegradable polymers could be useful as a potential drug delivery system for sustained drug release in the vitreous body.

Animals↗
PubMed1990

[Pathological studies of multiple submucosal gastric gland lesions in thirty-eight cases].

We have examined 38 stomachs with the adenocarcinoma and multiple submucosal gastric gland (SG) lesions. Almost the SG lesions consisted of the foveolar epithelium, which stained negative with alcian blue whereas the ordinary glands stained positive with con-A (III), or with both types of epithelium, and they had no atypicality. Only 14 out of 2,188 SG lesions (0.63%) showed atypical proliferation. Three hundred and forty-nine out of 1,535 SG that were examined by lysozyme staining were strongly lysozyme positive. Almost all the propria mucosa in the areas of the minute SG showed erosive lesions with an atrophy of ordinary glands, glandular erosion, and a regenerative epithelium. Eleven stomachs (11/38 cases, 29.0%) had multiple adenocarcinomas.

Adenocarcinoma↗