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Biomedical subjects

M Mochizuki

Publications and source records attributed to M Mochizuki.

At least 145 records · Page 8Linked to original sources
PubMed1998

Seroepidemiological survey of feline retrovirus infections in domestic and leopard cats in northern Vietnam in 1997.

The prevalence of infections with three feline retroviruses (feline immunodeficiency virus (FIV), feline leukemia virus (FeLV) and feline syncytial virus (FSV)) was examined in northern Vietnam in 1997. We collected a total of 77 blood samples from 69 domestic and 8 leopard cats, and examined the presence of anti-FIV and FSV antibodies and FeLV p27 antigen in the plasma samples by the indirect immunofluorescence and/or two commercial kits. None of the samples was positive for FIV and FeLV. The overall positive rate of FSV was 31% and the positive rates among the domestic and leopard cats were 29 and 50%, respectively. We isolated FSV from peripheral blood mononuclear cells of 6 domestic and one leopard cats.

Animals↗
PubMed1998

Repair of ulnar segmental defect by recombinant human bone morphogenetic protein-2 in dogs.

The efficacy of recombinant human bone morphogenetic protein-2 (rhBMP-2) combined with poly D, L lactic-co-glycolic acid (PLGA)/gelatin sponge complex (PGS) as a carrier on the repair of segmental long-bone defects was evaluated using an ulnar model in dogs. The defect was 2 cm in length and was fixed with bone plating. After implantation of PGS with or without rhBMP-2, the repair process of the defect was evaluated by serial radiography until 16 postoperative weeks. All defects treated with 160 micrograms or 640 micrograms of rhBMP-2/PGS revealed bone union radiographically by 12 postoperative weeks, whereas all defects treated with PGS alone revealed no radiographic evidence of healing throughout the experimental period. In defects treated with 40 micrograms of rhBMP-2/PGS, new bone appeared partially at the defects but did not accomplish union. Bone mineral contents at the defect sites after harvest at 16 weeks postoperatively were significantly (p < 0.05) higher in those treated with 160 micrograms or 640 micrograms of rhBMP-2 than in those treated with 40 micrograms of rhBMP-2 or PGS alone. Histologically, defects radiographically diagnosed as having achieved union showed the appearance of cortical bone and bone marrow cells. These findings suggest the use of rhBMP-2/PGS as a potential bone graft substitute in reconstructive surgery in dogs.

Animals↗
PubMed1998

Femoral nonunion fracture treated with recombinant human bone morphogenetic protein-2 in a dog.

This is the first report on successful treatment of spontaneous nonunion fracture of a dog by use of recombinant human bone morphogenetic protein-2 (rhBMP-2). A 4-year-old Pomeranian dog with a 2-year history of femoral nonunion fracture was treated with implantation of rhBMP-2. The dog had received surgical correction twice prior to the admission but radiography of the affected limb revealed a typical figure of nonunion fracture. Glossly, the fractured ends were sclerotic and the area between the ends was filled with fibrous tissue. After debridement the femoral shaft was fixed by an 8-hole plate. rhBMP-2 at a total dose of 256 micrograms was implanted with a synthetic carrier into the 8-mm defect formed by the debridement. Callus formation responding to rhBMP-2 was radiographically observed at 2 weeks after implantation and the defect reached radiographic union by 8 weeks after implantation. The plate was removed at 9 months after implantation. Any complications were not observed for 5 months after removal of the plate.

Animals↗
PubMed1998

Further development of a recombinant feline herpesvirus type 1 vector expressing feline calicivirus immunogenic antigen.

We previously reported the attenuation of thymidine kinase (TK) deficient mutant (C7301dlTK) of feline herpesvirus type 1 (FHV-1) in cats and the construction of a recombinant FHV-1 (C7301dlTK-Cap) inserted a precursor capsid gene of feline calcivirus (FCV) into the TK deletion locus of the C7301dlTK. In this study, we constructed a further improved recombinant FHV-1 (dlTK(gCp)-Cap) carrying a putative FHV-1 gC promoter sequence upstream of the FCV precursor capsid gene of the C7301dlTK-Cap. Growth kinetics of the dlTK(gCp)-Cap in cell cultures was similar to those of C7301dlTK and C7301dlTK-Cap. A strong expression of FCV immunogenic antigen by dlTK(gCp)-Cap was confirmed by indirect immunofluorescence and enzyme-linked immunosorbent assays. In addition, one vaccination with dlTK(gCp)-Cap protected cats more effective against subsequent virulent FCV challenge than that with C7301dlTK-Cap.

Animals↗
PubMed1998

Establishment and characterization of two cell lines derived from canine spontaneous osteosarcoma.

Two new canine osteosarcoma cell lines were established. One (OOS) was established from a 10-year-old female maltese dog with mandibular osteosarcoma and the other (HOS) from a 7-year-old male mongrel dog with scapular osteosarcoma. Histopathological types of OOS and HOS were mixed and fibroblastic cell type, respectively. Transmission electron microscopic features of HOS revealed prominent rough endoplasmic reticulum, suggesting higher malignancy comparing to OOS. Doubling time of OOS and HOS were 45.0 +/- 0.5 hr and 42.0 +/- 0.1 hr, respectively. Alkaline phosphatase activities of OOS and HOS were quite low. Histological features of tumor tissues produced by transplantation of these cells into nude mice were identical to those of original osteosarcomas.

Alkaline Phosphatase↗
PubMed1998

[A single dose toxicity study of magnesium sulfate in rats and dogs].

A single dose toxicity study of magnesium sulfate by intravenous administration was conducted in rats and dogs. The results are summarized in the following. Magnesium sulfate was administered once at dose levels of 90, 130, 200, 300 and 450 mg/kg to Crj:CD(SD) rats at 6 weeks of age. Deaths occurred in the 200 mg/kg and above groups in both sexes. The LD50 values were 206 mg/kg for males and 174 mg/kg for females. In the surviving animals, in the 130 mg/kg and above groups, tonic convulsions, abnormal gait and tachypnea were seen. However, these signs disappeared gradually and all animals returned to a normal state by 15 min after dosing. There were no treatment-related changes in the body weight or gross pathology. Magnesium sulfate was infused for 6 hr at dose levels of 75, 300 and 1200 mg/kg (12.5, 50 and 200 mg/kg/hr) to female beagle dogs at 6 months of age. No deaths were observed in any of the dose groups and it was considered that the lethal dose level would be higher than 1200 mg/kg(200 mg/kg/hr). In the 1200 mg/kg group, vomiting, decreased spontaneous movement, staggering gait, prone position and flush of the conjunctiva and ear auricles were seen. However, these signs disappeared gradually and animals returned to a normal state by 1 hr after dosing. There were no treatment-related changes in the body weight, food consumption or gross pathology.

Animals↗
PubMed1998

Evaluation of antifungal activity of an antifungal drug by in vitro simulation of in vivo pharmacokinetics of the drug against fungal hyphal growth.

An automatic drug concentration simulator (DCS) has been developed and its applicability has been demonstrated by in vitro simulation of the human plasma concentration-time curve of fluconazole (FLCZ) against hyphal growth of Candida albicans and Aspergillus fumigatus. The response of hyphal growth to FLCZ was continually monitored and analyzed using an automatic hyphal growth analyzing system (Bio-Cell Tracer). The simulated concentration of FLCZ by DCS was confirmed by HPLC. The DCS assay was reproducible with a mean coefficient of variation (C.V., n=3) of 5.38 %. When the growth of C. albicans hyphae was tested, there was a lag of onset of FLCZ effect between the time when FLCZ concentration became maximal (C MAX, 7.95 microg/ml ) and the point at which hyphal growth ceased. In contrast, FLCZ was found inactive against A. fumigatus. The newly devised technique could provide clinicians with important information in determining optimal dosing regimens for antifungal drugs.

Antifungal Agents↗
PubMed1998

[Estimated prevalence rate of HTLV-I uveitis in Chikugo].

To estimate the prevalence rate of human T-cell lymphotropic virus type 1 (HTLV-I) uveitis, an epidemiological survey was carried out in the Chikugo District of Fukuoka Prefecture between 1 September and 31 October 1995. The survey was done by sending questionnaires on uveitis patients to all ophthalmological institutes in the district and measuring the serum antibody to HTLV-I. The recovery rate of the survey was 39 of 48 institutes (81.3%). A total of 357 patients with uveitis were reported in the survey, of whom 317 (88.8%) were tested for their seropositivity to HTLV-I. Among them, 18 patients were counted as having HTLV-I uveitis (HU) on 1 October 1995. Based on these data together with the age- and sex-specific population of HTLV-I carriers in the Chikugo District, it was estimated that the crude prevalence rates of HU per 100,000 HTLV-I carrier population were 58.6 in males, 152.0 in females, and 112.2 in both sexes. The prevalence rate of HU was slightly higher than that of HTLV-I associated myelopathy.

Adult↗
PubMed1998

A longitudinal study of the development of crowded dental arch.

It is important to determine both where and when in the process of dental arch development crowding occurs. The authors investigated 81 children (boys/37, girls/44). These children were developing permanent dentition without early loss of deciduous or permanent teeth, which is considered to be one of the causes of malocclusion. Impressions were taken from subjects who had normal, spaced, or crowded permanent dental arch, and longitudinal casts made every two months from three years of age. In both the maxilla and the mandible, the transition to the crowded condition most often occurred (maxillary: 84.6%, mandibular: 64.5%) at the time of eruption. Crowding condition was also caused by the eruption of other teeth; however, this was rare. The maxillary and mandibular crowding mostly occurred (maxillary: 69.2%, mandibular: 77.4%) in the anterior teeth. It was seldom observed in the premolar and first molar regions.

Child↗
PubMed1998

[Treatment of cytomegalovirus retinitis in AIDS with an intraocular sustained-release ganciclovir implant].

Active cytomegalovirus (CMV) retinitis in patients with acquired immunodeficiency syndrome (AIDS) was treated with an intraocular sustained-release ganciclovir implant. A total number of 19 implants were performed in 15 eyes of 9 AIDS patients. The intraocular sustained-release ganciclovir was effective in preventing reactivation of CMV retinitis in 15 of the 19 implants, ineffective in 3, and undetermined in 1. All ineffective cases had been resistant to ganciclovir therapy before the implants. Vision after the therapy was maintained at better than 0.5 except for one eye. There were no serious ocular complications caused by the therapy. Among 5 patients with unilateral CMV retinitis, 2 unaffected eyes developed CMV retinitis during this therapy. In addition, another patient developed presumed CMV infection in other systemic organs. Based on these data, the intraocular sustained-release ganciclovir implant was considered to be useful for the treatment of CMV retinitis in AIDS.

AIDS-Related Opportunistic Infections↗
PubMed1998

Biology of human trophoblast.

In order to elucidate the regulation of placental growth, we have characterized the expression of proliferating cell nuclear antigen (PCNA), apoptotic DNA fragmentation and bcl-2 protein in human placenta during pregnancy. PCNA and bcl-2 protein expression were examined by immunohistochemical techniques, while the occurrence of apoptotic DNA fragmentation was assessed by in situ analysis of DNA 3'-end labeling method. Both PCNA expression and apoptotic DNA fragmentation were found in cytotrophoblasts (C-cells), being most abundant in early placenta, less abundant in midterm placenta and least abundant in term placenta. In contrast, bcl-2 protein expression was found in syncytiotrophoblasts (S-cells), being least abundant in early placenta, less abundant in midterm placenta and most abundant in term placenta. These data indicate that early placenta is characterized by the highly proliferative activity of C-cells associated with the increased occurrence of apoptosis, whereas term placenta is characterized by the abundant expression of bcl-2 protein in S-cells. Furthermore, effects of EGF on the proliferative activity and differentiated function of trophoblasts were investigated using an organ culture system. Explants of trophoblastic tissues were cultured with or without EGF, in the presence or absence of 10(-8)M triiodo-L-thyronine (T3) in a serum-free condition. In 4-5 week placentas, EGF and EGF receptor were almost exclusively localized in C-cells, and EGF augmented the proliferative activity of C-cells without affecting the ability to secrete hCG and hPL. By contrast, in 6-12 week placentas, EGF and EGF receptor were predominantly localized in S-cells, and EGF stimulated hCG and hPL secretion without affecting the proliferative activity of C-cess. The addition of T3 (10(-8)M) resulted in an increased secretion of immunoreactive EGF by cultured placental explants. These findings suggest that EGF acts as a local factor in regulating early placental growth and function in synergy with thyroid hormone. On the other hand, progesterone selectively inhibited pleise hCG (alpha, beta) mRNAs expression and decreased hCG secretion in normal placental tissues, whereas choriocarcinoma did not respond to progesterone. This suggests that inhibitory regulation of hCG synthesis in choriocarcinoma is different from normal placenta. It was also found that in molar trophoblasts and choriocarcinoma cells PCNA expression was high, but both bcl-2 protein and apoptotic signal expression were low. Characterization of choriocarcinoma hCG revealed that there are striking differences in carbohydrate structures between normal hCG and choriocarcinoma hCG. Sialic acid content in choriocarcinoma hCG was extremely lower compared to that in normal hCG. The detection of the alteration in hCG sugar chains is useful for biochemical diagnosis of choriocarcinoma.

Cell Differentiation↗
PubMed1998

[A case of choroidal metastasis from bronchial atypical carcinoid tumor (well-differentiated neuroendocrine cell carcinoma)].

We describe a case of choroidal metastasis from bronchial atypical carcinoid tumor (well-differentiated neuroendocrine cell carcinoma). In this report, we compared the images of indocyanine green infrared fluorescence angiography (IA) to the histological appearance of the metastatic tumor. A 48-year-old male patient presented with metastatic choroidal tumors in both eyes. The IA findings revealed high intensity of fluorescence in the center of the tumor, but low intensity at the edge. Afterwards, the patient underwent enucleation of his left eye because of secondary glaucoma. Microscopic examination of the resected eyeball disclosed two histological patterns: one was that of typical carcinoid tumor; the other atypical carcinoid tumor. In addition, the tumor blood vessels had proliferated more densely in the center of the tumor than at the edge. Only two case reports in the English literature, as for as we know, have previously described the precise histological examination of both choroidal metastasis and primary bronchial carcinoid tumor. This case suggests that the extraordinary IA images are caused by the histologic character of the metastatic tumor: 1. rich vascularity, 2. variety of distribution of the tumor vessels.

Bronchial Neoplasms↗
PubMed1997

Juvenile amyotrophy of the distal upper extremity: pathologic findings of the dura mater and surgical management.

STUDY DESIGN: Five cases of juvenile amyotrophy of the distal upper extremity were reviewed retrospectively to elucidate the pathophysiology of spinal cord dysfunction and the results of surgical management. OBJECTIVES: To clarify the pathogenesis of juvenile amyotrophy of the distal upper extremity and to present the results of a new surgical treatment. SUMMARY OF BACKGROUND DATA: Hirayama first reported this disorder in 1959. It is characterized by juvenile onset, slow progression, and involvement of the unilateral distal upper extremity. Recently, compression of the cervical spinal cord during neck flexion was implicated as a possible etiology of the disorder, but the exact etiology is still unknown. The value of surgical treatment for patients with juvenile amyotrophy of the distal upper extremity has not been established. METHODS: The clinical and radiographic characteristics of five patients with juvenile amyotrophy of the distal upper extremity were examined. All five patients were treated surgically with duraplasty in combination with posterior spinal fusion. Dynamic and computed tomographic myelography were performed before and after surgery. Intraoperative ultrasonography and conductive spinal cord evoked potentials were recorded before and after duraplasty. The surgical results and the histology of the resected dura were studied. RESULTS: Myelograms taken with the neck in a neutral position showed that the spinal cord was flattened in all five patients. When the neck was flexed, the dura and the spinal cord were compressed further. Intraoperative ultrasonography during neck flexion revealed an anterior shift of the spinal cord and decreased spinal cord pulsation. Amplitude of the conductive spinal cord evoked potentials decreased with neck flexion but increased after dural incision. Histologically, the dura appeared abnormal in that it contained few elastic fibers without the normal wavy structure. CONCLUSIONS: Juvenile amyotrophy of the distal upper extremity was characterized by inelastic dura that constricts and compresses the cervical spinal cord when the neck is in either a neutral or a flexed position. Abnormal dura appeared to be the cause of juvenile amyotrophy of the distal upper extremity. Duraplasty with spinal fusion are proposed as treatments.

Adolescent↗
PubMed1997

Detection of mutagenicity in Ames test using a metalloporphyrin/oxidant model system for cytochrome P450.

A chemical model system for cytochrome P450, a porphyrin and an oxidant, was used in Ames assay as a substitute for S9 mix. In the presence of tetrakis(pentafluorophenyl)porphyrinatoiron(III) chloride [Fe(F5P)Cl] and tert-butyl hydroperoxide (t-BuOOH), mutagenicity of N-nitrosodibutylamine (NDB) in Salmonella typhimurium TA1535 was detected. The mutagenicity depended on the pre-incubation period, and also on the concentration of an oxidant and of bacteria. In the chemical model system, pH affected the mutagenicity of NDB, which suggested that as observed in an enzymatic activating system, the mutagenicity was due to the labile alkylating species which was derived from NDB activated in the chemical activation system and was sensitive to pH. Under the optimum conditions; a higher concentration of an oxidant, a higher concentration of bacterial culture, and a weakly acidic medium, mutagenicity of N-nitrosodipropylamine in S. typhimurium TA1535 was also detected. Besides N-nitrosodialkylamines, 2-aminofluorene (2-AF) and benzo[a]pyrene (BaP) were also used as mutagens. Mutagenicity of 2-AF and BaP in S. typhimurium TA1538 were both detected in the same system as used in detecting the mutagenicity of N-nitrosodialkylamines. Ames test using a metalloporphyrin/oxidant model system makes it possible to detect mutagenicity derived from both base pair substitution mutagens and frameshift mutagens without using enzymatic activating system. These results demonstrate that the assay with the chemical model system is useful in detecting unstable unknown active mutagens or investigating the mechanisms of the metabolic pathway of mutagens or carcinogens in a protein-free medium.

Benzo(a)pyrene↗
PubMed1997

Immediate and chronic results of cutting balloon angioplasty: a matched comparison with conventional angioplasty.

BACKGROUND: At the initial stages of percutaneous transluminal coronary angioplasty (PTCA), several studies reported on the feasibility of coronary artery incision and dilatation leading to the extension of the PTCA technique. HYPOTHESIS: This study was designed to determine the immediate and chronic results of cutting balloon (CB) angioplasty. METHODS: This procedure was performed on 127 lesions in 110 patients (male 83%, age 61.8 +/- 9.3 years). RESULTS: The overall procedural success rates for the CB were 93.7% (119 lesions) and 92.7% (102 patients), while solitary CB without pre- and/or postdilatation was 76.4% (91 lesions). There was one major in-hospital complication (Q-wave myocardial infarction, 0.9%), but there were no deaths or emergency coronary artery bypass graftings. Significant angiographic dissections (> or = grade C) occurred in four patients, and coronary perforation occurred in one. The successfully treated CB group (95 lesions) was matched with the successful conventional angioplasty group (PTCA group) for chronic result assessment in regard to reference vessel size and lesion characteristics. In the CB group, postprocedural minimal luminal diameters were significantly larger and the percentage of stenosis at the stenotic site was significantly lower compared with the PTCA group. Restenosis occurred in 22 lesions (23.1%). This showed a significantly lower restenosis rate compared with the PTCA group (42.1%). In addition, the restenosis rate of the CB without inclusion of the pre- and/or postdilatation-treated lesions was 19.7%. CONCLUSIONS: (1) Cutting balloon angioplasty procedures can be performed with high success rates with few major inhospital events. (2) The restenosis rate in the CB group was significantly lower compared with the PTCA group.

Angioplasty, Balloon, Coronary↗
PubMed1997

Determination of the PCO2-dependent component of the H+ concentration in venous and arterial blood plasma.

In normal venous blood plasma, the regression line of [H+] plotted against the PCO2 was linear against the square root of PCO2. Sequential measurements in venous and arterial blood of PCO2 and [H+] showed that the venous-arterial (V-A) difference in [H+] was linearly related to the V-A difference in the square root of PCO2, the regression line having the same slope as that of the venous [H+] plotted against the square root of PCO2. These findings suggested that the venous [H+] on the regression line represents the PCO2-dependent component, of [H+], [H+]*. The PCO2-independent component, delta [H+], can then be given by subtracting [H+]* from the measured [H+]. The delta [H+] in venous blood agreed well with that in arterial blood with a correlation coefficient of 0.99, supporting the validity of the value of [H+]*.

Adult↗