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Biomedical subjects

I Shibata

Publications and source records attributed to I Shibata.

At least 19 recordsLinked to original sources
PubMed2000

Isolation of porcine epidemic diarrhea virus in porcine cell cultures and experimental infection of pigs of different ages.

This paper describes the isolation of porcine epidemic diarrhea (PED) virus in Vero and porcine cell cultures, and the influence of age on disease in experimental infection. PED virus was isolated from the small intestine of piglets inoculated with PED samples and cultured in Vero, porcine bladder and kidney cells propagated in collagen-coated tissue culture plates in maintenance medium (MM) containing trypsin. In porcine bladder and kidney cell cultures inoculated with isolated PED virus, cytopathic effects (CPE) including cell fusion were detected. Specific brilliant fluorescence was observed in the cytoplasm of these cells. Two- and 7-day old, and 2-, 4-, 8- and 12-week old specific pathogen-free (SPF) pigs were orally inoculated with PED virus isolated from an outbreak. All 2- and 7-day old pigs inoculated developed severe watery diarrhea from post-inoculation day (PID) 1 and died between PID 3 and 4. Although three of five 2-week old pigs developed diarrhea on PID 1-4, they eventually recovered. In the 4-week old group, three of five pigs had mild diarrhea for 1-2 days. None of the 8- and 12-week old pigs showed any clinical signs. Antibodies against PED virus were detected in all surviving pigs by virus neutralization (VN) test and immunofluorescence assay (IFA). Therefore, there is an age-dependent resistance to pathogenic PED virus infection in pigs.

Age Factors↗
PubMed2000

Experimental reinfection with homologous porcine reproductive and respiratory syndrome virus in SPF pigs.

The present examination was conducted to determine if the pigs infected with one strain of porcine reproductive and respiratory syndrome virus (PRRSV) would be protected against a subsequent homologous virus challenge. Sixteen 4-week-old SPF pigs were assigned to 2 experimental groups A and B. The pigs in group A were inoculated with 10(6.5) TCID50 of PRRSV by intranasal route. On 77 days post-inoculation (PI), pigs in groups A and B were similarly inoculated with same virus. After the secondary inoculation, the pigs in group A didn't show any clinical sign including pyrexia and reduction of white blood cell (WBC) number. Viremia was detected only on 3 days PI with low virus titer and any virus was not recovered from serum and tissues at the time of necropsy on 14 or 28 days PI. In contrast, pigs in group B showed pyrexia for 14 days and reduction of WBC number on 3 days PI. Viremia was detected between 3 and 28 days PI, and virus was isolated from several tissues of all pigs. These results indicate that previous exposure to PRRSV can prevent development of clinical signs and reduce virus proliferation in pigs after subsequent infection with the homologous PRRSV.

Animals↗
PubMed2000

Effect of the end-tidal xenon correction method on cerebral blood flow determination.

The objective of this work is to show how the end-tidal xenon correction method contributes to determining the cerebral blood flow (CBF) values. Respiratory xenon data from 443 patients (mean age, 59.1 +/- 13.5) were analyzed using two methods: the conventional fitting method and the end-tidal correction method. For both methods, xenon saturation rate constant (Ka1) and desaturation rate constant (Ka2) were calculated for washin and washout phases respectively. By applying the correction method, both the histograms for Ka1 and Ka2 change significantly; they become to have narrower distribution with smaller mean value. As the average effect based on computer simulation, if calculated CBF values using corrected Ka1 and Ka2 are 80 cc/100 g-tissue/min for the gray matter and 20 for the white matter, those using conventional Ka1 and Ka2 become 62.8 for the gray matter and 17.9 for the white matter. By applying the end-tidal correction method, obtained CBF values increase, and the extent of increase is larger when xenon inhalation speed is slower.

Aged↗
PubMed2000

[Radiosurgery for cystic metastatic brain tumor].

Stereotactic radiosurgery (SRS) for brain metastasis results in a high local control rate. But cystic metastatic tumor should have been a contraindication for SRS. Because it is often found that a cyst is too large to be irradiated, the tumor does not exist in the center of the irradiation field. Between 1995 and 1998, 8 consecutive patients underwent linear accelerator-based SRS for cystic brain metastases identified by computed tomography or magnetic resonance image scan. Stereotactic cyst aspiration is carried out after placement of the BRW frame under local anesthesia. All of the patients except one were confirmed to have sufficient reduction of the cysts. 5-7 days after stereotactic cyst aspiration, SRS was performed. The dose range was 25-30 Gy. In follow-up MRI, local recurrences and enlargement of cysts were not noted. Six patients with neurological symptoms recuperated satisfactorily. Median survival was 30 weeks from the date of radiosurgery. All of the patients died and the causes of death were related with the primary lesion. We conclude that our technique, a combination of stereotactic cyst aspiration and SRS is an effective measure which leads to palliation of neurologic symptoms and is a low risk treatment for patients with cystic brain metastasis.

Adenocarcinoma↗
PubMed1999

Elevated serum haptoglobin in pigs infected with porcine reproductive and respiratory syndrome virus.

We examined the two acute phase proteins, alpha (alpha)-1 acid glycoprotein (AGP) and haptoglobin (HP), in serum of pigs following experimental porcine reproductive and respiratory syndrome (PRRS) virus infection. Increased levels of serum HP, but not AGP, were observed from 7 to 21 days post-inoculation in the infected pigs. Furthermore, serum IL-6 increased in the infected pigs, but TNF-alpha did not. The increase of serum IL-6 in pigs following PRRS virus infection may induce production of HP. Also, in the field investigation, serum HP in pigs was dramatically increased after exposure to the PRRS virus.

Acute-Phase Proteins↗
PubMed1999

[Extraneural metastasis of pineal germinoma through a ventriculoperitoneal shunt, following histological change].

Primary germinoma of the central nervous system carries a good prognosis because of their radiosensitivity. Recurrence is rare and extraneural metastases are even more unusual. We report a unique case of a primary intracranial germinoma exhibiting complete response to radiotherapy, but recurring as an intra-abdominal yolk sac tumor. The presence of a VP shunt is thought to have facilitated metastatic spread of the intracranial neoplasm. An 21-year-old (corrected) male was admitted with headache and consciousness disturbance. Computed tomography (CT) revealed an enhanced tumor of the pineal region and hydrocephalus. A ventriculo-peritoneal shunt was emplaced immediately. No serum tumor markers such as alpha-fetoprotein or human chorionic gonadotropin were detectable. A test dose of radiotherapy (whole brain 20Gy) was given. The tumor size was remarkably decreased. Clinical diagnosis was germinoma. Additional whole brain radiation (total 45Gy) and whole spine radiation (20Gy) were given. The tumor and the hydrocephalus regressed completely and the patient returned to school. Three years later, he experienced a feeling of abdominal fullness. CT and echotomography of the abdomen showed a large peritoneal and intra-hepatic tumor. But MRI revealed no recurrent tumor of the pineal lesion or of the other areas in the central nervous system. Radiological and clinical findings showed no tumors in the testis, the retroperitoneal cavity, or the thymus. Laboratory investigation demonstrated elevated serum AFP (26,550 ng/ml). AFP level regressed after combined chemotherapy. However, the patient died due to pneumonia and multiple organ failure. Only needle necropsy was performed. The microscopic appearance of the peritoneal tumor was confirmed to be an endodermal sinus tumor. It was suspected to be a metastasis of the pineal tumor through the V-P shunt system.

Adult↗
PubMed1999

[Contralateral cerebellar infarction after aneurysmal clipping with pterional craniotomy: report of two cases].

A 77-year-old woman underwent right fronto-temporal craniotomy for a right ruptured IC-PC aneurysm (case 1), and a 44-year-old woman underwent right fronto-temporal craniotomy for a right ruptured BA-SCA aneurysm (case 2). They were clipped completely without any troubles during surgery. But postoperative CT scan demonstrated contralateral cerebellar infarction. We recognized left-hand tremor as a neurological deficit caused by cerebellar infarction in case 1. Concerning the mechanism of contralateral cerebellar infarction after pterional craniotomy, we think that it could be; --1) changing of venous blood flow by overdrainage of cerebrospinal fluid, 2) destruction of the bridging vein because of cerebral transformation with rapid decompression, 3) ischemia caused by brain retraction and compression during operation, 4) hypertension or hypoxia during operation, 5) crossed cerebellar diaschosis, and so on. In our 2 cases, we believe that perioperative CSF overdrainage caused the contralateral cerebellar infarction or CCD. To avoid this kind of infarction, we should try to take more protective and careful procedures as well as closer perioperative management.

Adult↗
PubMed1998

Experimental infection of maternally immune pigs with porcine reproductive and respiratory syndrome (PRRS) virus.

To investigate the influence of maternal antibody to porcine reproductive and respiratory syndrome (PRRS) virus infection, the following examination was done using conventional and SPF pigs. Ten 17-day-old conventional pigs with maternal antibody against PRRS virus and 6 44-day-old SPF pigs seronegative were inoculated intranasally with 10(5.0) TCID50 of PRRS virus. Two conventional and 4 SPF pigs were served as non-inoculated control. In conventional pigs, coughing and febrile response were observed after inoculation, and mean rate of weight gain reduced. One of the inoculated conventional pigs died on post-inoculation-day (PID) 28 and Haemophilus parasuis was isolated from the lung. Although febrile response was also observed in the inoculated SPF pigs, reduction in weight gain rate was not recognized. Virus was isolated from all the sera of inoculated conventional and SPF pigs except one conventional pig between PID 7 and 49, and between PID 7 and 28, respectively. Onset of viremia in the several conventional pigs delayed. Virus was isolated from the tissues of the 5 conventional pigs on PID 65 and from the tissues of the dead pig. On the other hand, virus was not isolated from the tissues of non-inoculated conventional pigs, and inoculated and non-inoculated SPF pigs. At the virus inoculation, antibodies by the indirect fluorescent antibody (IFA) assay against PRRS virus were detected in the sera of conventional pigs with antibody titers of 1:20. Antibody titers gradually decreased after inoculation and rose from PID 21 or 28 and were between 1:160 and 1:640 on PID 63. Virus neutralization (VN) antibody titers were 1:2 or 1:4 at the inoculation and gradually decreased. Apparent rise in VN antibody titer was not observed after the inoculation. In the sera of control pigs, both antibody titers gradually decreased and did not rise. In the sera of the SPF pigs, antibodies by the IFA assay were first detected on PID 7 or 14. The titers of antibodies rose and reached their maximum with 1:320 to 1:2,560 on PID 21 to 35. VN antibodies were first detected in PID 42 to 56 and thereafter, the titers ranged between 1:1 to 1:4. Control SPF pigs were free of antibody throughout the examination. Antigenic variability was not recognized between the inoculated and recovered viruses by the VN test. The prolonged duration of viremia and virus isolation from the tissues on PID 65 in conventional pigs with low maternal antibody might support the present of antibody-dependent enhancement activity of PRRS virus infection.

Ampicillin↗
PubMed1998

Experimental dual infection of cesarean-derived, colostrum-deprived pigs with Mycoplasma hyopneumoniae and pseudorabies virus.

To determine whether pseudorabies virus (PRV) infection increases the severity of pneumonia by Mycoplasma hyopneumoniae, 18, 10-week-old Cesarean-derived, colostrum-deprived pigs were randomly assigned to 3 groups of 6 pigs each. Pigs in groups A and C were inoculated intranasally with M. hyopneumoniae at 10-week-old. At 11-week-old, pigs in groups B and C were inoculated intranasally with PRV. All pigs were initially seronegative for M. hyopneumoniae and PRV. Three pigs of each group were euthanized at 12-week-old, and remaining pigs at 14-week-old. At necropsy, gross lesions in the lung were observed in the pigs of groups A and C. On post-inoculation-week (PIW) 2 with M. hyopneumoniae (at 12-week-old), lung lesions were recognized in one of the 3 pigs in group A and all the pigs in group C. The mean percentage of the lung lesions were 0.1% in group A and 9.8% in group C. M. hyopneumoniae was isolated from broncho-alveolar lavage fluids (BALF) of pigs in group A with titer of 10(2) to 10(3) CCU/0.2 ml and in group C with titer of 10(5) to 10(6) CCU/0.2 ml. On PIW 4 (at 14-week-old), lung lesions were observed in all the pigs in groups A and C, and the mean percentage of the lung lesions were 8.3% in group A and 17.2% in group C. M. hyopneumoniae was isolated from BALF in group A with titer of 10(4) to 10(7) CCU/0.2 ml and in group C with titer of 10(6) to 10(7) CCU/0.2 ml. PRVs were isolated from nasal swab and tissue samples in groups B and C. After inoculation, antibody against M. hyopneumoniae was detected in groups A and C, and against PRV in groups B and C. Under the present experimental conditions, PRV infection appear to have effect on the severity of experimentally induced acute mycoplasmal pneumonia in young pigs.

Animals↗
PubMed1998

Prevalence of antibodies of field pseudorabies virus in pigs of herd vaccinated with live vaccine.

This trial was performed in a 350-sow farrow-to-finish pig farm in which animals had been vaccinated against Aujeszky's disease with glycoprotein gC deletion (gC(-)) vaccine. The prevalence of antibodies against field pseudorabies virus (PRV) in serum samples collected from sows and fattening pigs during the period March 1995 to May 1997 was determined by using a commercial assay kit. The frequencies with which PRV-positive sows were found were 28.9% and 25.0% in March and October of 1995, 12.5% and 2.5% in April and October of 1996, and 0% in May of 1997. The fattening pigs tested at these times had no antibody to field PRV. These results thus indicate the probability that the PRV infection at the farm was eliminated by the gC(-) vaccine.

Animals↗
PubMed1998

Detection of bovine viral diarrhea virus (BVDV) using reverse transcription polymerase chain reaction assay.

The reverse transcription polymerase chain reaction (RT-PCR) was applied to detect bovine viral diarrhea virus (BVDV) for the rapid diagnosis. The primers were selected from the p80 region of BVDV gene. The RT-PCR assay detected all of the 17 BVDV strains tested including cytopathogenic and non-cytopathogenic strains, while specific amplification was not observed from 17 bovine viruses other than BVDV. Detection limit of the assay was 10(1.5) TCID50/ml. Sera and organ samples were collected from four field bovine viral diarrhea-mucosal disease (BVD-MD) cases; mucosal disease, abortion, diarrhea and persistent infection. The RT-PCR assay detected BVDV from those samples more than conventional virus isolation method.

Abortion, Veterinary↗
PubMed1998

[201T1C1 accumulation dynamics in glioma with different grades of malignancy: an investigation using dynamic SPECT].

Dynamic SPECT was performed using 201TICI in a total of 21 gliomas, 14 cases of glioblastoma multiforme (GM) and 7 cases of anaplastic astrocytoma (AA), to investigate the relationship between test results and malignancy. The accumulation of isotope (counts/pixel) in the tumor was measured every 3 minutes with dynamic SPECT. The initial 3-minute value was reduced from subsequent accumulations (counts/minute) to obtain the time-activity curve (TAC). Thallium index (TL index), the ratio of 15-minute accumulation in the tumor to that in the same region of the contralateral normal brain, was also calculated. TL index was significantly higher (p < 0.05, Mann-Whitney test) in GM (6.25 +/- 1.97) than in AA (4.10 +/- 1.66), although no clear differential value could be determined between the two. TAC in the GM group showed that compared with the initial 3-minute value, accumulation increased significantly (p < 0.05) at every measurement point after isotope injection: 6 minutes, 0.660 +/- 0.671; 9 minutes, 1.322 +/- 1.319; 12 minutes, 1.315 +/- 1.632 and 15 minutes, 1.234 +/- 1.552. The increase in isotope accumulation in the tumor after 6 minutes or later was noted in 11 of the 14 cases in the GM group. In the AA group, however, there were no significant differences between the initial 3-minute value and value after 6 minutes (-0.283 +/- 0.462), 9 minutes (-0.574 +/- 0.681), 12 minutes (-0.690 +/- 0.611) and 15 minutes (-0.707 +/- 0.636) after isotope injection. A decrease in isotope accumulation in the tumor after 6 minutes or later was noted in 6 of the 7 cases in the AA group. Compared with static SPECT, dynamic SPECT, which can be performed easily and quickly, is more useful in clinical settings because of its high ability to differentiate the grade of malignancy of gliomas.

Adult↗
PubMed1997

In vivo replication of porcine reproductive and respiratory syndrome virus in swine alveolar macrophages and change in the cell population in bronchoalveolar lavage fluid after infection.

Replication of porcine reproductive and respiratory syndrome (PRRS) virus in swine alveolar macrophages (AM) and cell population in broncho-alveolar lavage fluid (BALF) obtained from PRRS virus-infected pigs were investigated. BALF samples were periodically collected from 6 pigs infected with PRRS virus and 3 non-inoculated control pigs by means of fiber-optic bronchoscope between post-inoculation day (PID) 0 and 56. The mean ratio of macrophages in BALF collected from infected group was 92.7 +/- 3.2% before inoculation and gradually decreased from PID 14. On the other hand, the ratio of lymphocytes was 4.8 +/- 3.2% before inoculation and increased from PID 21 and indicated 41.8 +/- 9.1% on PID 28. After that, they decreased gradually and that of macrophages correspondingly increased. The ratio of neutrophils maintained between 0.7% and 5.1%. The ratios of macrophages, lymphocytes and neutrophils collected from control group were almost stable through the examination. Intracellular PRRS virus antigens in AM were detected from PID 2 by indirect immunofluorescence assay (IIFA). PRRS virus was first isolated from BALF samples collected from inoculated group between PID 2 and 49. From serum, virus was isolated between PID 2 and 21. Antibodies in sera measured by IIFA to PRRS virus were first detected on PID 14 and the antibody titer rose to 1:640 or 1:1,280. The results suggested that PRRS virus replicates in swine AM for a relatively long period.

Animals↗
PubMed1997

Effect of attenuated Erysipelothrix rhusiopathiae vaccine in pigs infected with porcine reproductive respiratory syndrome virus.

Twenty 2nd specific pathogen-free pigs were divided into 4 groups: Group A were infected with porcine reproductive and respiratory syndrome (PRRS) virus at 6 weeks of age and treated with available swine erysipelas and swine fever combined vaccine (vaccinated) at 7 weeks of age; Group B were vaccinated at 7 weeks of age and infected with PRRS virus at 8 weeks of age; Group C were vaccinated at 7 weeks of age: Group D were neither vaccinated nor infected with PRRS virus. All pigs were challenged to Erysipelothrix rhusiopathiae C42 strain at 10 weeks of age. No clinical signs appeared after vaccination of group A and B pigs, thus confirming that the safety of the vaccine was not influenced by infection with PRRS virus. None of the pigs in Groups A and C developed erysipelas after challenge exposure to E. rhusiopathiae. In contrast, fever and/or urticaria appeared transiently in all pigs of Group B after challenge exposure. At the time of challenge exposure to E. rhusiopathiae, the PRRS virus titer was high in sera of Group B, but was low in those from Group A. However, vaccination of pigs with attenuated E. rhusiopathiae was effective in dual infection with PRRS virus and E. rhusiopathiae, because the clinical signs were milder and the E. rhusiopathiae strain was less recovered from these pigs compared to pigs of group D.

Animals↗
PubMed1997

[Changes in metabolism and peritumoral circulation after radiosurgery of metastatic brain tumors: evaluation by three dimensional dual isotope SPECT].

Concurrent use of two different isotopes, 201T1C1 and 123I-IMP, in SPECT is useful in separative evaluation of tumor metabolism and peritumoral circulation. Three dimensional SPECT employed in our study has an obvious advantage over two dimensional SPECT for its accurate imaging of tumors and peritumoural areas. Changes of tumor metabolism and regional circulation in peritumoral edematous tissues were investigated by fused 3-D SPECT images using 201T1C1 and 123I-IMP. In this study, the volume of isotope accumulative and isotope defective regions were measured. Fusion of SPECT images was performed by the use of panning visualization software; Application Visualization System Medical View (K.G.T.). The threshold of 3-D rendering was determined by conforming the volume of the hemisphere and of the tumor estimated on CT to the volume of 123I-IMP and 201T1C1 accumulating area respectively. Accumulative volume of 201T1C1 in the tumor decreased remarkably at 7 days after radiosurgery (p < 0.01). Defective volume of peritumoral hypoperfusion was measured on 3-D SPECT. The average volume was 80.5 + 32.5cm3 before radiosurgery. It decreased by approximately 60% at 7 days after radiosurgery (p < 0.05). Analysis of 3-D SPECT images using two different isotope tracers is reliable and useful to evaluate early the changes of metabolism and peritumoral circulation in or around intracerebral tumors.

Aged↗
PubMed1996

Slow-reacting and complement-requiring neutralizing antibody in swine infected with porcine reproductive and respiratory syndrome (PRRS) virus.

Various conditions were evaluated and modified to enhance the sensitivity of the neutralization (NT) test for detecting antibody in swine infected with porcine reproductive and respiratory syndrome (PRRS) virus. Higher NT antibody titers were consistently obtained by the addition of 10% (v/v) complement, fresh guinea pig serum, to the virus diluent and by the incubation of serum-virus mixture at 4 degrees C for 24 hr. The appearance and persistence of antibodies detected by the modified NT test showed a similar pattern to those of antibodies detected by the indirect fluorescent antibody (IFA) assay, although the antibody titers obtained by the former method were consistently lower than those obtained by the latter method. Slow-reacting complement-requiring NT antibody was detected in sera from pig 2 weeks after infection with PRRS virus. The slow-reacting complement-requiring NT antibody in the early serum samples was sensitive to 2-mercaptoethanol (2-ME), whereas the slow-reacting complement-requiring NT antibody in the late serum samples was resistant to 2-ME. The initial phase may represent the IgM response and the later phase a change to IgG. A NT test was developed in which serum-virus mixtures were incubated at 4 degrees C for 24 hr with complement; this gave an improved sensitivity over the previous incubation at 37 degrees C for 60 min.

Animals↗
PubMed1996

Serological property and replication in cell cultures of porcine reproductive and respiratory syndrome viruses isolated in Japan.

The serological property and replication in swine alveolar macrophages (SAM) and MARC-145 cell cultures of 35 porcine reproductive and respiratory syndrome (PRRS) viruses isolated in SAM were investigated. All the isolates were reacted almost equally with antisera against three Japanese isolates including EDRD-1 strain (American type) in immunoperoxidase monolayer assay (IPMA), but weakly or did not react with antiserum against Lelystad virus (European type) indicating that the Japanese isolates are more closely related to an American type virus. Twenty two of 35 isolates replicated with CPE both in SAM and MARC-145 cells, whereas remaining 13 isolates did not show CPE in MARC-145 cells. The antigenicity of the isolates did not relate to the virus origin and the replication in the cell cultures.

Animals↗