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Biomedical subjects

M Ishikawa

Publications and source records attributed to M Ishikawa.

At least 199 records · Page 11Linked to original sources
PubMed1999

Three-dimensional computed tomographic angiography in lower extremity revascularization.

To evaluate the role of three-dimensional computed tomographic angiography (3D-CT) in peripheral artery bypass surgery, 49 patients with chronic lower limb ischemia underwent 3D-CT before and after a bypass operation. 3D-CT had a sensitivity of 96.8%, a specificity of 95.0% and an overall accuracy of 96.1% for the diagnosis of arterial and graft stenosis or obstructions. The ability to observe the acquired images at any angle was very useful for assessing the implanted graft in both aortoiliac and infrainguinal bypasses. Although these images equally identified arterial stenosis, obstruction, and the anastomotic morphology of bypass grafts as well as conventional angiography, the diagnostic accuracy was not helpful in the small arteries and grafts. 3D-CT is a low-invasive imaging method that is sufficient for forming strategies for bypass operations. In aortofemoral or femoropopliteal bypass surgery, 3D-CT thus provides sufficient imaging accuracy for bypasses up to the popliteal artery below the knee in patients with chronic limb ischemia.

Aged↗
PubMed1999

Clinical relevance of antibiotic-induced endotoxin release in patients undergoing hepatic resection.

It has been proved that antibiotics binding to penicillin-binding protein 3 (PBP3) are associated with the greater release of endotoxin than those that bind to PBP2 in both in vitro and animal models. The aim of this study is to evaluate the potential clinical implications of antibiotic-induced endotoxin release after hepatic resection. Forty-five patients who underwent hepatic resection in our clinic were enrolled. The patients were divided into two groups. Group A (n = 26): antibiotics that bind primarily to PBP3, including cefmetazole (CMZ), latamoxef (LMOX), flomoxef (FMOX), were used. Group B (n = 19); antibiotics that bind to both PBP2 and PBP3, including cefazolin (CEZ), cefoperazone (CPZ), cefotiam (CTM). Postoperative complications, liver functional tests, and chemical mediators [endotoxin, interleukins (IL-6, IL-8), tumor necrosis factor alpha (TNFalpha), granulocyte colony-stimulating factor (G-CSF), hepatotrophic growth factor (HGF) were examined after hepatic resection. There were no significant differences in the backgrounds of the two groups. Eight patients in each group developed postoperative complications; in particular, 9 of 13 patients with biliary tract carcinoma developed postoperative complications. No significant elevation of peripheral blood endotoxin was noted by the endospecy method, in any of the patients, although six died following sepsis. Pre- and postoperative levels of cytokines showed no significant difference between the two groups. Our data suggest that clinical antibiotic-induced endotoxin release would not occur after hepatic resection regardless of the antibiotic, probably owing to continuous scavenging of endotoxin from peripheral blood.

Analysis of Variance↗
PubMed1999

Different expression patterns of nitric oxide synthase isozymes in various gynecological cancers.

The expression of nitric oxide synthase (NOS) in human gynecological cancers, including ovarian cancers, uterocervical cancers, and endometrial cancers for example, was examined by the reverse transcriptase/polymerase chain reaction, coupled with Southern hybridization and by immunohistochemistry. Nitric oxide synthase II (NOS II), an inducible form, was expressed in more than 90% of the cancers. Nitric oxide synthase I (NOS I), a neuronal form, was expressed in 58% of all the ovarian cancers, in which the serous type is found more frequently (5 out of 7) than the mucinous type (2 out of 6), and in all clear-cell cancers. The frequency of NOS I expression in uterocervical cancers and endometrial cancers was relatively low. Nitric oxide synthase III (NOS III), an endothelial form, was detected in 25% of ovarian and 33% of endometrial cancers, while no expression was detected in uterocervical cancers. In terms of cancer types, all clear-cell adenocarcinomas and most of the serous-type adenocarcinomas expressed both NOS I and NOS II, while most uterine squamous carcinomas and endometrial adenocarcinomas expressed only NOS II. However, there was no correlation between the frequency of NOS expression and patients' age or the clinical stage of the disease. Since NO increases vascular permeability and blood flow, the high frequency of NOS expression in gynecological cancers may serve to stimulate and promote tumor growth.

Blotting, Southern↗
PubMed1999

Clinical applications of two-color telomeric fluorescence in situ hybridization for prenatal diagnosis: identification of chromosomal translocation in five families with recurrent miscarriages or a child with multiple congenital anomalies.

Two-color fluorescence in situ hybridization (FISH) analysis using human chromosome arm-specific telomeric probes (telomeric probes) was used successfully to detect each derivative chromosome of a translocation carrier in five couples who requested a prenatal diagnosis in future pregnancies. Most of the human chromosome terminal bands are G-band-negative, and even FISH analysis using whole-chromosome painting (wcp) probes are often of insufficient complexity to detect subtle chromosomal changes. A complete set of human telomeric probes was developed to improve the sensitivity of diagnosis of microdeletions or other cryptic rearrangements in telomeric regions. Two-color telomeric FISH was the only possible method for precise prenatal diagnosis of one of the couples, because the carrier's chromosomal aberration was too subtle to be detected by wcp FISH or conventional methods. We have demonstrated that two-color telomeric FISH has the potential to be a powerful new tool in the detection of cryptic chromosomal rearrangements involving telomeric regions in prenatal diagnosis precisely and in time.

Abnormalities, Multiple↗
PubMed1999

Isolation and localization of an IDDMK1,2-22-related human endogenous retroviral gene, and identification of a CA repeat marker at its locus.

We intended to confirm genetically the involvement of the IDDMK1,2-22 gene in the pathogenesis of insulin-dependent diabetes mellitus (IDDM). For this purpose, we isolated a human endogenous retrovirus gene, possibly corresponding to IDDMK1,2-22. The isolated gene showed 99.8% and 99.7% homologies in nucleotide sequences to a part of the env region and of the 3'-LTR region, respectively, compared to those of IDDMK1,2-22 deposited in GenBank. The gene also showed a close relation to HERV-K18, of which the 3'-LTR sequence gave 99.5% homology. It seemed likely that these genes represented the same single gene. The newly isolated gene was present in the first intron of the CD48 gene and was located on chromosome 1q21.2-q22. A CA repeat marker was found approximately 20 kb upstream from the 5'-end of the 5'-LTR of the gene.

Chromosome Mapping↗
PubMed1999

Classification of polycystic ovary syndrome into three types according to response to human corticotropin-releasing hormone.

OBJECTIVE: To evaluate disturbances of the hypothalamic-pituitary-adrenal axis in women with polycystic ovary syndrome (PCOS). DESIGN: Retrospective cohort study. SETTING: Yokohama City University, Yokohama, Japan. PATIENT(S): Sixty women with PCOS and 19 women with normal menstruation. INTERVENTION(S): Administration of human corticotropin-releasing hormone (hCRH), dexamethasone suppression testing, and stimulation of ovulation with clomiphene citrate. MAIN OUTCOME MEASURE(S): Plasma cortisol and ACTH levels, plasma androstenedione and DHEAS levels, and ovulation rates. RESULT(S): In women with PCOS, plasma ACTH and cortisol levels were significantly higher and the plasma ACTH level after the administration of hCRH was higher than in controls. Based on the response to hCRH, patients with PCOS could be classified into three categories: those with a normal response to hCRH (group 1), those with an exaggerated response of ACTH to hCRH (group 2), and those with a high basal level of cortisol and a poor response to hCRH (group 3). In groups 2 and 3, DHEAS levels were significantly higher, suppression of androstenedione by dexamethasone was significantly greater, and ovulation rates with clomiphene citrate were significantly lower than in group 1. CONCLUSION(S): This classification provides insight into the underlying cause of PCOS and thus is useful in selecting appropriate treatment.

17-alpha-Hydroxyprogesterone↗
PubMed1999

Dual interaction producing both territorial and schooling behavior in fish.

Fish schools are frequently observed without a leader and an explicit condition forming school. Several models of schooling have been proposed focusing on the influence of neighbors, and introducing probability distributions, while these models are based on the separation of schooling and territorial behavior. We frequently consider the duality of aggregation of animals, in which behavioral patterns involve both attraction and repulsion, antagonistic with each other. The idea of probability does not explain this duality that can provide both schooling and territorial behavior. From these biological facts, we have constructed a behavior model in which the influence of neighbors is formulated by the interface between the states of neighbors and a map of changes in these states. This interface uses a self-similar nowhere differentiable transition map which is temporally constructed, encompassing a crucial duality of repulsive and attractive forces hidden in the interaction among fishes. We tested it with computer simulations against the biological reality of schooling and territorial behavior. Due to the influence neighbors can have on duality, the same model can show both schooling behavior with a high degree of polarization and territorial behavior.

Animals↗
PubMed1999

Computerized assessment of the mastoid air cell system.

There have been many arguments on the development of pneumatization of temporal bone. However, a technique for direct volume measurement from high resolution computed tomography has never been reported. The aim of this paper is to develop a technique by using digital image processing to measure the volume of the mastoid air cell system. Forty three ears of 26 healthy subjects (13 males and 13 females) without a history of chronic or exudative otitis media, clear signs of Meniere's disease, severe sensorineural hearing impairment or malformation of temporal bone were eligible for enrolment in this study. Using a digital image processing technique, only the black air cells and tympanic cavity on the CT films are easily selected. Then, after image processing, only areas of these extracted black pneumatized parts are calculated. Consequently, the volume of pneumatized parts of temporal bone could be calculated separately as total volume and as partial volume that divided by several CT planes. The average volume of pneumatization in 43 temporal bones was 5.97 ml. However, since the volume of pneumatization in the temporal bone has traditionally been estimated by analyzing areas on X-ray films, the new method described in this study is significant for its ability to directly measure the volume of pneumatization in the temporal bone.

Adult↗
PubMed1999

Activation of three types of voltage-independent Ca2+ channel in A7r5 cells by endothelin-1 as revealed by a novel Ca2+ channel blocker LOE 908.

1. We have shown that in addition to voltage-operated Ca2+ channel (VOC), endothelin-1 (ET-1) activates two types of Ca2+-permeable nonselective cation channel (NSCC) in A7r5 cells: its lower concentrations (< or = 1 nM; lower [ET-1]) activate only an SK&F 96365-resistant channel (NSCC-1), whereas its higher concentrations (> or = 10 nM; higher [ET-1]) activate an SK&F 96365-sensitive channel (NSCC-2) as well. 2. We now characterized the effects of a blocker of Ca2+ entry channel LOE 908 on NSCCs and store-operated Ca2+ channel (SOCC) in A7r5 cells, and using two drugs, clarified the involvement of these channels in the ET-1-induced increase in the intracellular free Ca2+ concentrations ([Ca2+]i). Whole-cell recordings and [Ca2+]i monitoring with fluo-3 were used. 3. LOE 908 up to 10 microM had no effect on increases in [Ca2+]i induced by thapsigargin or ionomycin, but SK&F 96365 abolished them. 4. In the cells clamped at -60 mV, both lower and higher [ET-1] induced inward currents with linear iv relationships and the reversal potentials of -15.0 mV. Thapsigargin induced no currents. 5. In the presence of nifedipine, lower [ET-1] induced a sustained increase in [Ca2+]i, whereas higher [ET-1] induced a transient peak and a sustained increase. The sustained increases by lower and higher [ET-1] were abolished by removal of extracellular Ca2+, and they were suppressed by LOE 908 to 0 and 35%, respectively, with the LOE 908-resistant part being abolished by SK&F 96365. 6. These results show that LOE 908 is a blocker of NSCCs without effect on SOCC, and that the increase in [Ca2+]i at lower [ET-1] results from Ca2+ entry through NSCC-1 in addition to VOC, whereas the increase at higher [ET-1] involves NSCC-1, NSCC-2 and SOCC in addition to VOC.

Acetamides↗
PubMed1999

Effects of S-0509, a novel CCKB/gastrin receptor antagonist, on acid secretion and experimental duodenal ulcers in rats.

BACKGROUND: S-0509, 2-[(tert-butoxycarbonylmethyl) [(m-(carboxy-phenyl)-ureidomethyl-carbonyl]] aminobenzo phenone, was developed as a potent and selective CCKB/gastrin receptor antagonist that does not affect the central nervous system. METHODS: We evaluated the effects of S-0509 on gastric acid secretion and duodenal ulcerogenic and healing responses in rats comparing it with L-365,260, another CCKB/gastrin receptor antagonist. RESULTS: S-0509 (0.1 approximately 10 mg/kg, i.d.) was able to dose-dependently decrease basal acid secretion and inhibit the acid secretory responses induced by both pentagastrin (60 microg/kg/h, i.v.) and peptone (10%, i.g.) but not histamine (4 mg/kg/hr, i.v.) or carbachol (60 microg/kg/h, i.v.). L-365,260 (10 and 30 mg/kg, i.d.) caused only partial a suppression of the acid secretory response to pentagastrin but not to other stimuli, including peptone treatment. On the other hand, a duodenal ulcerogen, mepirizole (200 mg/kg, s.c. ) caused an increase in acid secretion and resulted in penetrating ulcers in the proximal duodenum, and these ulcers gradually healed over 3 weeks. S-0509 significantly inhibited both the acid secretory (> 1.0 mg/kg, i.d.) and ulcerogenic (> 3 mg/kg, p.o.) responses induced by mepirizole when it was given as a pre-treatment. It also promoted significantly the healing of these ulcers (> 3 x 2 mg/kg, p. o.) when it was given twice daily for 14 days. In contrast, L-365, 260 (30 mg/kg) tended to reduce the severity of mepirizole-induced duodenal ulcers, with a slight inhibition of acid secretion, but it caused no influence on the healing response of these ulcers. CONCLUSION: These results confirmed that S-0509 is a selective CCKB/gastrin receptor antagonist with potent antisecretory action in vivo conditions, and further demonstrated that this agent not only prevents the development of duodenal ulcers but also shows healing promoting action on duodenal ulcers, probably through the blockade of CCKB/gastrin receptors.

Animals↗
PubMed1999

A monoclonal antibody, 3G12, reacts with a novel surface molecule, Hal-1, with high expression in CD30-positive anaplastic large cell lymphomas.

We established a monoclonal antibody, 3G12 (IgG1), with antiproliferative effects on a human T-cell leukaemia cell line, SUP-T13. Among haematolymphoid cell lines, 3G12 reacted with most T-cell lines, Epstein-Barr transformed B-cell lines, some myelomonocytic cell lines and, most strongly with an anaplastic large cell lymphoma (ALCL) cell line, Karpas 299. The cell panel reactive with 3G12 was similar, but not identical, to that of the anti-CD30 antibody Ber-H2. 3G12 induced Fas-independent apoptosis in SUP-T13 and it also induced growth-inhibition in a limited number of other cell lines, but not Karpas 299. Immunohistochemical studies on paraffin-embedded tissue specimens demonstrated that 3G12 reacted with most CD30-positive ALCL cases and some T-cell lymphomas and some Hodgkin's lymphomas, but not with B-cell lymphomas or non-haematogeneic tumours. The immunoprecipitation study with 3G12 demonstrated a major band of 200 kD and a minor band of 100 kD, which were different from CD30. Thus 3G12 defines a novel antigen that shares a similarity to CD30 in terms of distribution among haemopoietic cells. The data suggest that the 3G12-defined antigen, designated Hal-1, is important as a marker for ALCL and may play a role in its pathogenesis.

Animals↗
PubMed1999

The role of oxidative DNA damage in human arsenic carcinogenesis: detection of 8-hydroxy-2'-deoxyguanosine in arsenic-related Bowen's disease.

Arsenic is widely distributed in nature in the form of either metalloids or chemical compounds, which cause a variety of pathologic conditions including cutaneous and visceral malignancies. Recently, reactive oxygen species have been hypothesized to be one of the causes of arsenic-induced carcinogenesis. 8-Hydroxy-2'-deoxyguanosine is one of the major reactive oxygen species-induced DNA base-modified products that is widely accepted as a sensitive marker of oxidative DNA damage. We studied the presence of 8-hydroxy-2'-deoxyguanosine by immunohistochemistry using N45.1 monoclonal antibody in 28 cases of arsenic-related skin neoplasms and arsenic keratosis as well as in 11 cases of arsenic-unrelated Bowen's diseases. The frequency of 8-hydroxy-2'-deoxyguanosine positive cases was significantly higher in arsenic-related skin neoplasms (22 of 28; 78%) than in arsenic-unrelated Bowen's disease (one of 11; 9%) (p < 0.001 by chi2 test). 8-Hydroxy-2'-deoxyguanosine was also detected in normal tissue adjacent to the arsenic-related Bowen's disease lesions. Furthermore, arsenic was detected by neutron activation analysis in the deparaffined skin tumor samples of arsenic-related disease (four of five; 80%), whereas arsenic was not detected in control samples. Our results strongly suggest the involvement of reactive oxygen species in arsenic-induced human skin cancer. Key word: neutron activation analysis.

8-Hydroxy-2'-Deoxyguanosine↗
PubMed1999

Glycerol attenuates the adherence of leukocytes in rat pial venules after transient middle cerebral artery occlusion.

Intravenous infusion of glycerol has been used in patients with a cerebral infarction, expecting improvement in brain edema and cerebral blood flow (CBF). However, the mechanism of the improvement of CBF has not been clearly demonstrated. The aim of this study in the rat pial microvasculature after transient middle cerebral artery occlusion (MCAO) is to examine the effects of glycerol on leukocyte-endothelium interaction, which plays a critical role in the pathogenesis of brain injury by ischemia/reperfusion and concerns induction of secondary brain damage. Rhodamine 6G-labeled leukocytes at the brain surface were visualized with intra-vital fluorescence videomicroscopy through a closed cranial window and an analysis was made of the number of adherent leukocytes and the centerline leukocyte velocity in the venule before MCAO, after reperfusion of MCAO and after infusion of glycerol (Group 1) or saline (Group 2). The number of adherent leukocytes decreased and the centerline leukocyte velocity increased statistically significantly immediately after the infusion of glycerol in Group 1, but there was no significant change in Group 2. The infusion of glycerol washes away the adherent leukocytes and prevents them from interfering with the blood cell and plasma flow. Furthermore, secondary brain damage may be relieved by decreasing the adherence of leukocytes. In conclusion, modulating the adherence of leukocytes is one of the important factors in the neuroprotective effect of glycerol.

Animals↗
PubMed1999

Zygomatic arch cracking for cosmetic improvement: technical note.

We describe a simple cracking method for removing the zygomatic arch. The drilling line of the zygomatic arch is partially drilled from the back, and the surface is left undrilled. The zygomatic arch is cracked during its removal in order to secure its position for later fixation. Dead bone spaces can be avoided by this method and the zygomatic arch can be replaced in its original position. By adding this procedure to the standard technique, this cracking method is a simple, safe and useful way to achieve better cosmetic results.

Humans↗
PubMed1999

Liver transplantation in Japanese and Australian/New Zealand children with biliary atresia: a 10-year comparative study.

OBJECTIVE: To compare Japanese with Australian/New Zealand (ANZ) children with biliary atresia who were treated by liver transplantation, and evaluate the indications for and timing of transplantation. DESIGN: Retrospective study. SETTING: Queensland Liver Transplant Service (QLTS), Australia. SUBJECTS: 43 Japanese and 30 ANZ children with biliary atresia who required transplantation between 1985 and 1992. INTERVENTIONS: The 43 Japanese children had 52 transplants, and the 30 ANZ children had 33. MAIN OUTCOME MEASURES: Morbidity, mortality, and long term survival. RESULTS: The Japanese children had significantly lower serum albumin concentrations than the ANZ children preoperatively (mean (SD) 32 (7) g/L compared with 37 (5), p<0.05). The actuarial survival at 7 years of the ANZ children was significantly higher than that of the Japanese children (79% compared with 49%, p<0.05). There were 24 deaths (17 Japanese, 40%, and 7 ANZ, 23%); 2 of the ANZ and 7 of the Japanese children died more than a year after transplantation. All 26 children who were well-nourished at the time of transplantation defined as a Z-score (weight or height minus mean weight or height for age, sex, and race, divided by the SD) of -1 or more were alive at 1 month compared with 11 of the 47 poorly-nourished children (Z-score <-1). Survival among the Japanese declined after 1 year, and there was no association with Z-scores. Overall, Z-scores for weight improved significantly after transplantation, whereas those for height improved a little, but not significantly so. Japanese children were significantly shorter than ANZ children, and their Z-scores for height did not improve after transplantation. CONCLUSION: liver transplantation should be done as soon as possible for children with biliary atresia to maximise survival and growth.

Adolescent↗
PubMed1999

Codon 72 polymorphism of p53 as a risk factor for patients with human papillomavirus-associated squamous intraepithelial lesions and invasive cancer of the uterine cervix.

Squamous intraepithelial lesions (SIL) and invasive cancer of the uterine cervix are thought to be a series of lesions derived from normal cervical squamous tissue. Infection by high risk human papillomavirus (HPV) and integration of viral DNA may initially lead normal cervical cells to become pre-malignant cells in SIL and result in cervical malignancies later on. High risk HPVs, including types 16 and 18, produce a viral protein, E6, which is required for viral replication in host cells. The E6 protein is able to bind to host p53 causing inactivation of its function through the mechanism of ubiquitin-dependent degradation. It has recently been reported that the extent of p53 dysfunction caused by HPVs depends on the status of a polymorphism at codon 72 of p53, Pro or Arg. In that study, it was demonstrated that a patient homozygous for the Arg allele had about a seven times higher risk of developing cervical cancer than a patient homozygous for Pro. In an attempt to confirm this result and elucidate whether this allelic deviation of the Arg genotype seen in invasive cervical cancer occurs in the pre-malignant lesion SIL, we analyzed 219 SIL and 101 invasive cancer samples from Japanese patients using a PCR-based assay. Samples from 88 SIL and 76 invasive cancers were identified as HPV-infected samples and used for further analyses. In these, the frequencies of Arg homozygotes were 31.8, 33.0 and 36.8% in controls, SIL and invasive cancer, respectively. The distributions of the different alleles of codon 72 (Pro/Pro, Pro/Arg and Arg/Arg) did not show significant differences between either control and SIL groups or control and invasive cancer groups. Also, no difference in the frequency of Arg/Arg genotype was detected even between the control and HSIL groups or control and invasive cancer infected with high risk HPVs groups. In conclusion, there was no obvious relationship between the Arg genotype at codon 72 of p53 and predisposition to HPV-associated cervical neoplasia.

Amino Acid Sequence↗
PubMed1999

The clinical efficacy of low-dose step-up follicle stimulating hormone administration for treatment of unexplained infertility.

The present study was designed to compare the clinical efficacy of low-dose step-up follicle stimulating hormone (FSH) administration with conventional FSH protocol (FSH was injected daily starting with a dose of 150 IU), both combined with intrauterine insemination (IUI), for the treatment of unexplained infertility. A total of 97 unexplained infertility couples was randomly assigned to one or other of the two treatment groups, either conventional FSH with IUI (48 patients) or low-dose step-up FSH with IUI (49 patients), and only the first treatment cycle was evaluated in each protocol. The difference in pregnancy rates per cycle was not statistically significant between the low-dose FSH group and the conventional group [seven of 49 (14.3%) and seven of 48 (14.6%) respectively]. A significant reduction in the incidence of ovarian hyperstimulation syndrome (OHSS) was observed in the low-dose group (8.3% versus 27.1%, P < 0.05). The incidence of moderate OHSS requiring hospitalization was reduced significantly in the low-dose group (low-dose 0% versus conventional 16.7%, P < 0.01). However, the low-dose protocol did not completely prevent multiple pregnancies. Our results suggest that the low-dose step-up FSH treatment appeared to be useful for the treatment of unexplained infertility because of the high pregnancy rates and the significant decrease in the incidence of OHSS.

Adult↗