Biomedical subjects

Y Inaba

Publications and source records attributed to Y Inaba.

At least 91 records · Page 5Linked to original sources

PubMed1998

Antibody response of lions inoculated with inactivated calicivirus vaccine experimentally prepared.

The majority of lions and tigers in a Safari park in Japan were suffering from acute vesicular disease caused by a calicivirus infection. All of these animals were injected subcutaneously with an inactivated calicivirus vaccine experimentally prepared with one of the seed viruses originally isolated from sick lions. Seroneutralizing antibody of paired sera collected from ten female lions at two week intervals was measured. A significant elevation of specific antibody was detected in the serum samples and no local or systemic reactions associated with vaccination were observed.

Animals↗

PubMed1998

[Arterial redistribution of extrahepatic collaterals to the liver under temporary balloon occlusion of the proper hepatic artery].

Three patients with liver metastases receiving transarterial chemotherapy underwent embolization of extrahepatic collaterals to the liver under temporary balloon occlusion of the proper hepatic artery. Enhancement in the liver and tumors was observed at CT arteriography through the right inferior phrenic artery and was accentuated under balloon occlusion in all patients. A Cyanoacrylate-Lipiodol mixture was infused through the right inferior phrenic artery to occlude arterial communications with intrahepatic arteries. Better contrast agent distribution was obtained in all patients after embolization. It is suggested that this procedure can be effective for arterial redistribution against extrahepatic collaterals to the liver.

Antineoplastic Agents↗

PubMed1998

[Mechanism of vancomycin resistance in MRSA strain Mu50].

The mechanism of vancomycin resistance in methicillin-resistant Staphylococcus aureus (MRSA) Mu50 was investigated. More than 3 times increase of the incorporation of 14C-GluNAc into the cell wall of Mu50 was observed compared to those of vancomycin-susceptible strains FDA209P, H-1, LR5P1. The amount of cytoplasmic murein-monomer precursor increased more than 3 times in Mu50 compared to those of control strains. There was an increased production of PBP1, PBP2, and PBP2', which were 1.51, 17.2, and 7.06 times greater, respectively, in Mu50 than those in H-1, and 2.38, 4.46, and 1.96 times greater respectively, than those in LR5P1. By transmission electromicrograph, it was shown that the cell wall of Mu50 was twice thicker than that of LR5P1. Increase of tightly-bound vancomycin to the cell wall fraction was observed in Mu50 when compared to those in FDA209P and H-1 strains. From these results, the increase of the vancomycin targets, free D-Ala-D-Ala residues in the cell wall, in number, due to the activated cell wall synthesis, and/or decrease of the cross-linkage of the cell wall was suggested to be the mechanism of vancomycin resistance in the Mu50 strain.

Anti-Bacterial Agents↗

PubMed1998

[Ethical issues regarding individual data collection and utilization in community health care programs].

To understand the nature of ethical issues in community-based health care programs, we conducted a mail survey of subjects who were public health nurses employed by municipal governments. The questionnaire consisted of questions about data collection, usage, disclosure, and educational experience. In 1996 we received 536 completed questionnaires which were then analyzed. Regarding who should input data into computers, the number of those who considered that municipal offices other than public health nurses would be the most appropriate for the input of examination data was the largest, followed by those who felt that contracting out was best. Many of the public health nurses considered that they needed to obtain informed consent for collection, usage and disclosure of sensitive items, such as data on HIV infection. The number of those considering that they could not disclose results of examinations to other community-based specialists in health and welfare without the subject's agreement was very high. In health examination programs, the public health nurses requested information on date of birth and occupations, but there was some hesitation in requesting the latter information. Although about a half of subjects responded that they did not require data concerning the first sexual intercourse in cervical cancer screening, 90 percent asked breast feeding history in breast cancer screening. Approximately 90 percent gave results of the examination to participants personally through personal communication or mail. Of the respondents, 40 percent reported having had educational courses on ethics while the others did not. There were some responses that reminded us of the unsatisfactory level of understanding about ethical issues, which underlined the need to emphasize importance, of including this in educational curricula.

Community Health Services↗

PubMed1998

[Increase of non-amidated muropeptides in the cell wall of vancomycin-resistant Staphylococcus aureus (VRSA) strain Mu50].

The mechanism of resistance was studied with vancomycin-resistant Staphylococcus aureus (VRSA) strain Mu50. It was demonstrated that the incorporation of 14C-N-acetylglucosamine into the cell wall of Mu50 was not suppressed in the presence of 8 microliters/ml of vacomycin, whereas it was completely suppressed in vancomycin-susceptible strains FDA209P and H-1. Increased binding of vancomycin to the wall of Mu50 was observed compared to the control strains: 1.7 x 10(16) (Mu50), 6.1 x 10(15) (209P), and 6.7 x 10(15) (H-1) vancomycin molecules/mg cell wall, respectively. Remarkable proportion of the cell-wall component muropeptides were non-amidated in the cell wall of Mu50. In concordance with this phenomena, peptidoglycan cross-linkage decreased strikingly in the Mu50 strain. Free D-Ala-D-Ala residues at the end of muropeptides in the pre-existing cell wall generated by decreased cross-linkage seems to account for increased vancomycin binding. The increase of vancomycin-resistance level is presumably caused by sequestration of vancomycin molecules from primary target point on cell membrane. It was considered that at least two phenotypic changes are required for the vancomycin resistance in the Mu50 strain. First, as we have described previously, is the activated cell wall synthesis, and second, the reduction of cross-linkage of peptidoglycan by production of non-amidated muropeptide precursors.

Acetylglucosamine↗

PubMed1998

The apoptotic changes of testicular germ cells in the obstructive azoospermia models of prepubertal and adult rats.

PURPOSE: It has been suggested that prepubertal obstruction of the seminal tract may result in irreversible damage to spermatogenesis. We examined whether accelerated apoptosis in prepubertal obstruction has a deleterious effect on spermatogenesis in adulthood. MATERIALS AND METHODS: We studied apoptotic changes of both prepubertal and adult obstructive azoospermia rat models by means of an in situ end-labeling technique and electron microscopy, and by examination of the pathological changes. Four groups were designed as follows. Group 1: bilateral vasectomies performed at ten days of age (prepubertal vasectomy model); Group 2: sham operation performed at ten days of age; Group 3: bilateral vasectomies performed at eight weeks of age (adult vasectomy model); Group 4: sham operation performed at eight weeks of age. Three rats in each group were killed weekly, and the testes and epididymides removed and weighed. Germ cell apoptosis was detected by in situ end-labeling, and the apoptotic index (AI) was calculated by dividing the number of in situ labeled cells by the total number of seminiferous tubules. The developmental change of testis and epididymis, the diameter of seminiferous tubules, and the number of spermatogonia were also examined. Histopathological examination of tubular diameter and the number of spermatogonia and Sertoli cells was done by PAS staining. The number of spermatogonia divided by the number of Sertoli cells per tubular cross section was expressed as spermatogonia-Sertoli cell ratio (S-S ratio). RESULTS: At 3 and 4 weeks of age, rats of group 1 demonstrated a significantly higher apoptotic index of germ cells than did the sham-operated rats of group 2 (p <0.05). No significant differences were seen between groups 3 and 4. The increased apoptosis in group 1 seemed to be reduced by the formation of epididymal granulomas. The tubular diameter of group 1 at 16 weeks of age was significantly smaller than that of groups 2, 3, or 4. The S-S ratios were lower at stages IV, V and VI in group 1 at 16 weeks-of-age following vasectomy at 10 days of age compared with that in group 2. CONCLUSIONS: We conclude that an increase of apoptotic degeneration of germ cells in the prepubertal period may cause irreversible changes in germinal stem cells, resulting in hypospermatogenesis in adulthood.

Aging↗

PubMed1998

Experimental infection in SPF kittens with a particular calicivirus strain originally isolated from lion.

Two SPF kittens were experimentally infected via the intranasal route with a strain of calicivirus originally isolated from sick lion suffering from vesicular disease. Fever, 40.3 degrees C and 40.7 degrees C, and vesicular formation in tongue and snout were reproduced in both kittens. The infected virus was recovered from nasal, oral and rectal swabs. A longer duration of virus recovery was proved with oral swab samples taken from 1 to 10 and 12 days post infection. This suggests that tongue and oral tissues are the main tissues for virus multiplication.

Administration, Intranasal↗

PubMed1998

[Characteristics of home care patients with intractable neurological diseases (Nanbyo) in Tokyo].

The purpose of this study was to identify the characteristics of home care of patients with intractable neurological diseases. A survey was conducted of members of Tokyo Medical Association who were home visit doctors. They responded to questions about their patients who have suffered from either Parkinson's disease (PD), spinocerebellar degeneration (SCD), or amyotrophic lateral sclerosis (ALS), and whose home care have been supported by the care system for at least three months. Of 205 survey questionnaires collected, 198 were effective to be analyzed. The sample consisted of 105 patients with PD (53.0%), 63 patients with SCD (31.8%), and 30 patients with ALS (15.2%). The mean age of the PD was 75.5 years with a range of 53 to 90, SCD was 66.5 years with a range of 39 to 88, and ALS was 58.7 years with a range of 42 to 86. The major findings in this study were as follows: 1) The patients who had one or more medical equipment installed at the beginning of home care were 30% of ALS, 9% of PD and 18% of SCD. As time elapsed, patients who needed to have some medical equipment installed increased in ALS greater than in PD and SCD. 2) The home doctors predicted that the condition of 37% of ALS patients, 9% of PD, and 8% of SCD would probably be deteriorating within one month. 3) Of the 30 patients with ALS, 47% experienced hospitalization three times or more compared to 27% of PD and 21% of SCD. The most prevalent reason for hospitalization for ALS was respite of caregivers, PD and SCD, however, were hospitalized for control of prescription, a change for the worse, or treatment of other diseases. 4) Ninety percent of ALS caregivers felt extremely tired or slightly tired. Their home doctors responded that 83% of ALS caregivers did their best in caregiving. 5) ALS patients utilized social resources such as volunteers, care workers, services of supply and maintenance of medical equipment, and emergency care for 24 hours more than SCD and PD. In the conclusion, ALS patients experienced the highest hospitalization of the three diseases and respite of family caregivers was necessary. They showed a higher utilization of various social resources than other diseases. It is important to consider these characteristics of home care patients by diseases in order to prepare and develop the necessary support system of home care for the intractable neurological patients.

Adult↗

PubMed1998

[MRI, SPECT and MRS findings in a case of acute hemiplegia syndrome with a marked hemispheric brain edema].

Magnetic resonance imaging (MRI), single photon emission computed tomography (SPECT) and magnetic resonance spectroscopy (MRS) were successively recorded in a 3-year-old girl with the acute hemiplegia syndrome. She was admitted to our hospital with complaints of fever, loss of consciousness and right side dominant clonic convulsions evolving into status epilepticus, and then recovered with sequelae of aphasia and right hemiparesis. Electroencephalography showed a generalized slow rhythm at the onset, and very low activities on the left hemisphere in the follow-up records. Brain CT and MRI revealed edema of the left hemisphere initially, followed by left side dominant brain atrophy. No cerebral vascular lesion was detected by magnetic resonance angiography. N-Isopropyl-[123I]-iodoamphetamine SPECT showed marked hypoperfusion of the left hemisphere accompanied by crossed cerebellar diaschisis. MRS at the initial stage detected decreased N-acetyl-aspartic acid and increased lactic acid signals in the bilateral hemisphere, which subsequently normalized only on the right side. These findings suggested brain damage and neural cell death in the left cerebral hemisphere, caused by acute encephalopathy. SPECT and MRS are useful new techniques to study the pathophysiology of the acute hemiplegia syndrome.

Acute Disease↗

PubMed1998

[Emergence of hetero-VRSA strains in Japanese hospitals and its countermeasure].

Vancomycin-resistant MRSA (VRSA with MIC > or = 8 mg/L) has been described, recently. Although the incidence of VRSA has been low in Japanese MRSA strains, hetero-VRSA (heterogeneously resistant VRSA with MIC levels of 2-4 mg/L) is found in considerable abundance in Japanese hospitals, that may explain fairly frequent therapeutic failure in the vancomycin treatment of MRSA infection. Hetero-VRSA may also serve as precursor for VRSA in some clinical settings where it is exposed to high concentrations (8 mg/L or above) of vancomycin.

Aminoglycosides↗

PubMed1998

[A novel method of detecting Staphylococcus aureus heterogeneously resistant to vancomycin (hetero-VRSA)].

We have developed a new method of detecting clinical S. aureus strains possessing heterogeneous resistance to vancomycin (hetero-VRSA). The method exploits characteristic antagonism between vancomycin and beta-lactam antibiotics against the strain Mu3, a representative hetero-VRSA. The method comprises of the following procedures: 1) overnight culture of bacteria is streaked on brain heart infusion agar containing 4 micrograms/ml of vancomycin, 2) paper discs impregnated with any one of beta-lactam antibiotics are placed onto the plate, and 3) the plate is incubated at 37 degrees C and the cell growth was observed after 24 h and 48 h of incubation. The Mu3 cells were grown only around the beta-lactam discs due to the antagonism between vancomycin and beta-lactam against Mu3 cells. A total of 321 MRSA clinical strains isolated in 1995 and 1996 from 12 medical facilities in Japan were tested with this method. A total of 39 strains (12.1%; 24 h) and 67 strains (20.96%; 48 h) grew around the beta-lactam discs. All the 10 strains (representing 10 facilities), tested with the analysis of resistant subpopulations to vancomycin, showed similar heterogeneous patterns as observed with Mu3. The method was considered as a convenient and rapid substitute for the population analysis, the authentic method for the detection of hetero-VRSA strains.

Anti-Bacterial Agents↗

PubMed1998

Bone density and mechanical properties in femoral bone of swim loaded aged mice.

Effects of swimming on bone density and mechanical properties of femur were investigated in aged male and female mice. R/1 strain of senescence accelerated mouse (SAM) at eleven months old was used. Two groups of males and two groups of females each consisting of 7 mice were used. One male and one female groups were loaded with a swim regiment of 40 min a day, 5 days a week for 6 consecutive weeks. The remaining groups were used as the controls. All mice were fed with the standard diet and water ad libitum during the experiments. The results of this study indicated that (i) the body weight was significantly (P < 0.05) lower in the swimming groups than in the control groups in both sexes. (ii) The bone density was significantly higher (P < 0.05) in the swimming groups than in the control groups in both sexes. However, there was no significant difference in cortical thickness index. (iii) In the mechanical properties of bone, there were no significant differences in the level of the maximum breaking force, the ultimate stress and the deformation between the swimming and the control groups in both sexes. However, the elasticity of the bone of the female mice in the swimming group was significantly higher (P < 0.05) than that of the control group. These results suggest that regimented swimming for the aged mice might suppress age-associated bone loss, and the effect of exercise in the females is greater that in the males.

Aging↗

PubMed1997

Isolation and characterization of mouse nasal-associated lymphoid tissue.

A method for isolation of mouse nasal-associated lymphoid tissue (NALT), which is a principal mucosal lymphoid tissue of the respiratory tract in rodents, was developed. The paired lymphoid organs could be separated from the upper jaw by peeling away the palate where NALT was localized bilaterally on the posterior side. About 3 x 10(5) lymphocytes could be obtained from one NALT fragment. The NALT lymphocyte fraction from normal BALB/c mice contained T- and B-cells in about equal numbers, and contained about 4 times as many CD4+ T-cells as CD8+ T-cells when analyzed with a FACScan fluorescence analyzer. The composition of the NALT lymphocytes was similar to that of the lymphocytes from the portion of the nasal cavity remaining after isolation of the NALT. The NALT lymphocyte fraction from mice infected 7 days previously with influenza virus was also characterized. The numbers of NALT T- and B-cells from the infected mice were approximately 2 and 3 times higher than those of non-infected mice, respectively. In parallel with the cell increase, NALT lymphocytes produced IFN-gamma when cultured for 24 h and contained cells secreting influenza virus-specific IgA and IgG antibodies. The results suggest that this method can be successfully used for investigating cellular dynamics of mucosal immunology in the upper respiratory tract.

Animals↗

PubMed1997

Intermittent hepatic arterial infusion of high-dose 5FU on a weekly schedule for liver metastases from colorectal cancer.

PURPOSE: We performed phase I and II studies to examine the usefulness of intermittent hepatic arterial infusion of high-dose 5-fluorouracid (5-FU) for patients with liver metastasis from colorectal cancer. METHODS: As the phase I study, 1000, 1250 and 1500 mg/m2 of 5-FU were administered over 5 h by hepatic arterial infusion on a weekly schedule to establish the recommended dose. Based on the results of the phase I study, the phase II study was performed to confirm the efficacy of the recommended dose thus obtained. RESULTS: In the phase I study, the dose-limiting factors of this therapy were gastrointestinal and central nervous system toxicities, and the recommended dose was judged to be 1000 mg/m2. In the phase II study, 1000 mg/m2 of 5-FU was administered over 5 h once a week on an outpatient basis, and this therapy was repeated as long as possible. The response rate was 78% (25/32), with an overall median survival time of 25.8 months (without extrahepatic lesions 25.9 months; with extrahepatic lesions 17.3 months). CONCLUSIONS: (1) Compared with conventional continuous infusion, the advantages of this therapy were that it caused no decrease in the patient's quality of life as a result of being permanently equipped with a pump and it thus enabled more cost-effective use of the pump, (2) The phase II study on 32 patients showed that this therapy caused no serious toxicities, with a response rate of 78% and a survival time of 25.8 months, which exceeded the results with conventional continuous infusion. If the reproducibility of these results is established in further studies involving multicenter collaboration, this therapy will be able to become the standard local chemotherapy for liver metastases from colorectal cancer. (3) Important problems remaining to be solved are improvement of the technical aspects and studies of combined use with systemic chemotherapy. Furthermore, to finally determine the position of this therapy in the treatment system for liver metastasis from colorectal cancer, it is necessary to conduct comparative trials versus systemic chemotherapy, using the survival time as the end-point.

Antimetabolites, Antineoplastic↗

PubMed1997

Antigenic diversity of Akabane virus detected by monoclonal antibodies.

The antigenic properties of 21 Japanese field isolates and two Australian strains of Akabane (AKA) virus (Simbu serogroup, bunyavirus) isolated from 1959 to 1990 were compared by enzyme-linked immunosorbent assay (ELISA), plaque-reduction neutralization (PRNT) and hemagglutination inhibition (HI) tests using monoclonal antibodies (Mabs) to the OBE-1 strain of AKA virus. Sixteen Mabs were established by fusing P3X63Ag8U1 mouse myeloma cells and spleen cells from BALB/c mice immunized with the OBE-1 strain. Of the 16 clones, 13 produced immunoglobulin (Ig) which precipitated glycoprotein G1 and three produced Ig which precipitated nucleoprotein (N). Twelve out of 13 Mabs had both NT and HI activities to not only the homologous OBE-1 strain but also the other isolates. By the competitive binding assay, at least five antigenic regions for G1, and two for N were defined. Some of the anti-G1 Mabs which reacted to the same antigenic region had unique reactivity while anti-N Mabs recognizing the same epitope reacted with almost the same degree to all of the isolates. Finally, nine epitopes of the G1 protein in five different antigenic regions have been identified. There was no striking correlation between isolation date and place of the isolates and their reactivity to Mabs. A most interesting result is that three isolates collected in the same place over a three week period had different reactivity patterns detected by ELISA, showing great antigenic variation of the virus. AKA virus may be a single gene pool consisting of different genotypes in the field.

Animals↗

PubMed1997

Effects and serum levels of thrombopoietin in a case of chronic thrombocytopenia with achondroplasia.

Thrombopoietin (TPO), produced mainly in the liver, is a major regulator of platelet production. Serum TPO levels are generally increased in thrombocytopenia. We report a case of a 12-year-old boy with chronic severe thrombocytopenia, achondroplasia and nephritis. Severe chronic thrombocytopenia was found at 9 months of age. It was resistant to any treatment. Studies on megakaryocytic colonies in vitro revealed that the marrow cells responded well to TPO and no plasma inhibitor was found. Although hepatic function test results were normal, serum TPO levels in the patient (0.94 fmol/ml) were consistent with those in age-matched children (0.49-1.75 fmol/ml). Chronic thrombocytopenia requires individual evaluation before clinical trials with TPO.

Achondroplasia↗

PubMed1997

The production of IL-8 in cerebrospinal fluid in aseptic meningitis of children.

Neutrophils accumulate initially in the cerebrospinal fluid (CSF) of aseptic meningitis, perhaps because of increased levels of granulocyte colony-stimulating factor (G-CSF), macrophage inflammatory protein-1alpha (MIP-1alpha), and IL-8 in the subarachnoid space. We studied levels of these cytokines in children with aseptic meningitis using ELISA. When meningeal symptoms existed, IL-8 levels (1399 +/- 1600 ng/l, n = 32) in the CSF were significantly higher than those either after meningeal symptoms disappeared (61 +/- 56 ng/l, n = 18) or in controls (44 +/- 63 ng/l, n = 27) (P < 0.0001). High levels of IL-8 on admission dropped sequentially. Significant correlations were found between IL-8 levels and either neutrophil counts (r = 0.612), G-CSF levels (r = 0.873) or MIP-1alpha levels (r = 0.623) in the CSF of the affected patients (P < 0.0001). IL-8 values in serum were lower than in the corresponding CSF samples from all individuals with meningeal symptoms. The IL-8 mRNA was detectable by reverse-transcribed polymerase chain reaction (PCR)-assisted amplification in fresh leucocytes from the CSF, but not from the peripheral blood of a healthy volunteer. The culture of CSF mononuclear cells produced high levels of IL-8 (approximately 2750 ng/l). These data indicate that IL-8 levels rise transiently at the initial stage of aseptic meningitis, and that mononuclear cells that migrate into the CSF are a cellular source of this chemokine. We suppose that IL-8, in addition to G-CSF and MIP-1alpha, contribute to the localized neutrophil accumulation during the disease.

Adolescent↗

PubMed1997

Gas dispersion in a model pulmonary bifurcation during oscillatory flow.

In order to clarify the gas transport process in high-frequency oscillation, we measured the axial velocity profile and the axial effective diffusivity in a single asymmetric bifurcating tube, based on the Horsfield airway model, with sinusoidally oscillatory flow. The axial velocity profiles were measured using a laser-Doppler velocimeter, and the effective diffusivities were evaluated using a simple bolus injection method. The axial velocity profile was found to be nonuniform, promoting axial gas dispersion by the spread of the concentration profile and lateral mixing. The geometric asymmetry of the bifurcation was responsible for the difference in gas transport between the main bronchi. The axial gas transport in the left main bronchus was 2.3 times as large as that of the straight tube, whereas the gas transport in the right main bronchus was slightly larger than that of the straight tube. Thus localized variation in gas transport characterized the heterogeneous respiratory function of the lung.

Bronchi↗