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Biomedical subjects

M Shimizu

Publications and source records attributed to M Shimizu.

At least 73 records · Page 4Linked to original sources
PubMed2002

Potential remedy against Echinococcus multilocularis in wild red foxes using baits with anthelmintic distributed around fox breeding dens in Hokkaido, Japan.

The effect of bait-delivered anthelmintic to reduce the prevalence of Echinococcus multilocularis in wild red foxes was evaluated in Koshimizu, in the eastern part of Hokkaido, Japan. The study area (200 km2) was divided into baited and non-baited sections. The anthelmintic baits were distributed around fox den sites in the baited section every month for 13 months. After 1 year of the anthelmintic bait distribution, the prevalence of E. multilocularis in foxes, evaluated either by the parasite egg examination (from 27.1 to 5.6%) or coproantigen ELISA (from 59.6 to 29.7%), decreased in the baited section contrasting to that in the non-baited section (parasite egg: from 18.8 to 24.2%; ELISA: from 41.9 to 45.8%). The prevalence of E. multilocularis in grey red-backed vole Clethrionomys rufocanus, caught around fox dens, born after bait distribution also decreased and was significantly lower than that in non-baited section. However, within the study periods, the coproantigen-positive rate in fox faeces sporadically increased, while egg-positive rate constantly decreased. Since coproantigen ELISA can detect pre-patent infection, this observation indicates that reinfection pressure in the baited section was still high even after the 13 months of anthelmintic bait distribution. Therefore, the bait distribution longer than our study period is required for the efficient control of E. multilocularis in wild red fox population.

Animals↗
PubMed2002

Monitoring C-reactive protein in beagle dogs experimentally inoculated with Ehrlichia canis.

The concentrations of C-reactive proteins (CRP) in the plasma of five beagle dogs experimentally inoculated with Ehrlichia canis increased markedly. The concentrations began to increase between 4 and 16 days and peaked between 15 and 42 days after inoculation of E. canis. The peak concentrations ranged from 217.8 to 788.8 microg/ml (452.6 +/- 228.1 SD). After the peak, the concentrations of CRP decreased rapidly. The PCR product of 16S rRNA of E. canis became detectable in the five dogs between 18 and 27 days after inoculation of E canis. Antibodies to E canis were detected in plasma from the dogs between 5 and 15 days after inoculation of E. canis. The timings of seroconversion and of the start of the increase in CRP were approximately similar and the high concentrations of CRP in the plasma of the dogs tended to become apparent when the PCR product of 16 S rRNA of E. canis became detectable.

Animals↗
PubMed2002

Lymphoepithelial lesion of the parotid gland.

We describe a case of lymphoepithelial lesion of the parotid gland, also known as salivary lymphoepithelial lesion. Lymphoepithelial lesions are usually seen in conjunction with autoimmune disease of the salivary glands and these lesions do not always remain benign. Our case consisted of two masses that had different imaging features. Moreover, we could investigate the changes of the size and internal architecture on imaging due to the postponement of surgical intervention on the masses. At review 6 months later, the size of the masses had increased. The aims of this paper were to: (1) investigate the contribution of gray-scale sonography, power Doppler sonography, magnetic resonance imaging, and computed tomography to the diagnosis; and (2) consider the appropriate imaging modality to follow-up this case to monitor for recurrence or malignant transformation.

Diagnosis, Differential↗
PubMed2002

Local perivascular application of low amounts of a plasmid encoding for vascular endothelial growth factor (VEGF165) is efficient for therapeutic angiogenesis in pigs.

Clinical trials have demonstrated therapeutic benefit in inducing angiogenesis in chronic occlusive arterial disease. The route of application mostly used was the intramuscular injection of high dosages of plasmid. Therefore, a local perivascular application of low amounts of vascular endothelial growth factor (VEGF) plasmid was used in an interventional occlusion model, and the effect of VEGF on coronary and peripheral occlusions compared in the same animal model. Coronary and peripheral arteries were chronically occluded in Pietrain pigs using a non-surgical, interventional approach. Adventitial delivery of the DNA for VEGF was performed with a needle injection catheter. The DNA was applied as lipoplexes using the novel cationic liposomes DOCSPER. Optimized transfer conditions were used. Angiography, polymerase chain reaction (PCR), reverse transcriptase-polymerase chain reaction (RT-PCR) and immunohistochemistry were undertaken within a follow-up period of 6 months. Expression of the transfected VEGF gene was observed at 1 and 3 weeks following application. The DNA was detected up to 5 months following application. Around occluded coronary arteries, there was formation of new collaterals and arterial prolongation, whereas surrounding occluded peripheral arteries there was no collateralization but development of new arterial branches was seen. Results demonstrate that the response to VEGF is also sufficient, when minimal amounts of plasmid encoding for VEGF are applied locally into the perivasculature allowing for more safety of this therapy. Comparison of treatment of chronic coronary and peripheral arterial disease revealed differences in angiogenesis following VEGF application during a total follow-up period of almost 6 months which may be related to their different developmental origins. This may have important implications for developing future therapeutic strategies using VEGF in different vessels.

Animals↗
PubMed2002

Statistical parametric mapping in brain single photon computed emission tomography after carbon monoxide intoxication.

The purpose of this retrospective study was to assess regional cerebral blood flow in patients after carbon monoxide intoxication by using brain single photon emission computed tomography and statistical parametric mapping. Eight patients with delayed neuropsychiatric sequelae and ten patients with no neuropsychiatric symptoms after carbon monoxide intoxication were studied with brain single photon emission tomography imaging with 99mTc-hexamethyl-propyleneamine oxime. Forty-four control subjects were also studied. We used the adjusted regional cerebral blood flow images in relative flow distribution (normalization of global cerebral blood flow for each subject to 50 ml x 100 g(-1) x min(-1) with proportional scaling) to compare these groups with statistical parametric mapping. Using this technique, significantly decreased regional cerebral blood flow was noted extensively in the bilateral frontal lobes as well as the bilateral insula and a part of the right temporal lobe in the patients with delayed neuropsychiatric sequelae as compared with normal volunteers (P< 0.005). In the patients with no neuropsychiatric symptoms, significantly decreased regional blood flow in the bilateral frontal lobes particularly on the left side was detected. There was a significantly decreased regional cerebral blood flow in the right frontal lobe and insula in the patients with delayed neuropsychiatric sequelae as compared to those with no neuropsychiatric sequelae. It is concluded that statistical parametric mapping is a useful technique for highlighting differences in regional cerebral blood flow in patients following carbon monoxide intoxication as compared with normal volunteers. The selectively reduced blood flow noted in this investigation supports the contention that the decrease following carbon monoxide intoxication may be prolonged and further worsen in the frontal lobe. In addition, the present study may help to clarify the characteristics of the pathophysiological alteration underlying delayed neuropsychiatric sequelae.

Adult↗
PubMed2002

Dermatitis herpetiformis in Japan: an update.

BACKGROUND: Although dermatitis herpetiformis (DH) is a relatively common disease in Caucasian populations, it is rare in Asian populations including the Japanese. We encountered a Japanese case of DH which showed granular IgA and C3 deposits in the papillary dermis and which was associated with gluten-sensitive enteropathy but no HLA-B8/DR3/DQ2. OBJECTIVE: The purpose of this study is to describe the characteristics of Japanese DH cases, since most of them have been reported in Japanese language and dermatologists outside Japan are not familiar with the characteristics of Japanese DH. METHODS: We have reviewed all 34 Japanese DH cases reported previously. RESULTS: We found several features of Japanese DH compared with Caucasian DH, such as a high frequency of the fibrillar pattern, rarity of gluten-sensitive enteropathy and an absence of the HLA-B8/DR3/DQ2 haplotype. CONCLUSION: There might be significant differences in pathophysiology between Caucasian and Japanese DH cases.

Biopsy, Needle↗
PubMed2002

In vitro antiseptic susceptibility of clinical isolates from nosocomial infections.

To evaluate the susceptibility of a large number of strains to various antiseptics, we elaborated a simple, qualitative broth turbidity method in which we could quickly judge the efficacy visually. For this method, we prepared a modified neutralizer broth, consisting of trypticase soy broth containing 15% Tween 80, 1% soybean lecithin and 0.5% sodium thiosulfate. The susceptibilities of Serratia marcescens No. 26 to 4 antiseptics obtained from the turbidity method showed a good agreement with those obtained from the colony-counting method; the 4 antiseptics tested were povidone-iodine (PVP-I), chlorhexidine gluconate (CHG), benzalkonium chloride (BAC) and alkyldiaminoethylglycine hydrochloride (AEG). Both PVP-I and BAC had complete efficacy in 0.5 min against all isolates tested [100 isolates of S. marcescens, 103 of Klebsiella pneumoniae, 99 of Pseudomonas aeruginosa, 19 of Alcaligenes faecalis and 30 of A. xylosoxidans subsp. xylosoxydans (A. xylosoxydans)]. In contrast, the effectiveness of CHG was weak compared with PVP-I, BAC and AEG. Strong resistance against AEG was noted even after 3-min exposure in 1 isolate each of A. faecalis and A. xylosoxydans. It is concluded that the turbidity test is a simple and accurate method to evaluate susceptibility to various antiseptics and that it is suitable for a screening of a large number of strains. Among the 4 antiseptics tested, PVP-I and BAC showed a consistently high activity against all isolates, confirming PVP-I and BAC to be clinically useful antiseptics.

Anti-Infective Agents, Local↗
PubMed2002

Induction of cellular senescence in a telomerase negative human immortal fibroblast cell line, LCS-AF.1-3, by human chromosome 6.

In immortal cells (LCS-AF.1-3) which originated from cultured skin fibroblasts from a patient with Li-Fraumeni syndrome, a specific deletion has been identified on chromosome 6. To examine the relationship between this deletion and the loss of function in aging genes, we performed microcell mediated chromosome transfer (MMCT) of normal human chromosome 6 into LCS-AF.1-3 cells and analyzed their characteristics. Transferred human chromosome 6 induced morphological changes in the cells and cellular senescence with growth suppression. In a revertant clone that had escaped from induced senescence, a specific deletion was found at D6S309 in the transferred chromosome 6. High molecular weight telomeric sequences were lost in a clone that had been induced to senescence by introduction of human chromosome 6. On the other hand, human chromosome 7 induces senescence in immortal cells by suppressing the alternative lengthening of telomere (ALT) mechanism. We also performed MMCT of chromosome 7 and discuss the effect of chromosome transfer by comparing the two chromosomes. LCS-AF.1-3 cells containing a transferred chromosome 7 showed no changes in immortality. These results suggest that genes which are new candidates for aging and which suppress the ALT mechanism are located in the region D6S309 in human chromosome 6.

Blotting, Southern↗
PubMed2002

[Surgical treatment of aneurysm of the ductus arteriosus in the adult].

Aneurysm of the ductus arteriosus is rare, however, reports on this lesion have increased recently with the progress of thoracic aortic surgery in Japan. We report 3 male cases aged 58, 59, 73 years. Aneurysms and total aortic arch were replaced by artificial graft through median sternotomy using selective cerebral perfusion in 2 cases. Through left posterolateral thoracotomy using deep hypothermia with circulatory arrest, proximal descending thoracic aorta including the aneurysm was replaced in 1 case. Their postoperative courses were uneventful. Surgery for this lesion is safe and various surgical approaches and circulatory supporting methods can be selected depending on the size of aneurysm and associated lesions.

Aged↗
PubMed2002

[Platelet activation in obstructive sleep apnea syndrome].

The incidences of cardiovascular and cerebrovascular diseases are reportedly higher in patients with obstructive sleep apnea (OSA) than in OSA-free subjects, though the mechanism remains unknown. Recently, the contribution of activated platelets to a number of pathological conditions such as stroke or ischemic heart disease has been suggested. We hypothesized that the expression of activated platelet markers resulting from OSA might be higher than in healthy subjects. By flow cytometry using monoclonal antibodies, we measured two such markers, PAC-1 and CD 62 P, in OSA patients and healthy subjects. Twelve healthy men (age, 52.7 +/- 12.8 y/o; and body mass index (BMI), 22.2 +/- 16.1 kg/m2; mean +/- S.D.) and 20 male patients with OSA (age, 50 +/- 7.96 y/o; BMI, 28.1 +/- 3.3 kg/m2; apnea hypopnea index (AHI), 38.2 +/- 21.2 times/hr; and lowest SpO2, 75.6 +/- 11.3%) were enrolled in this study. PAC-1 expression was significantly higher in OSA patients (65.1 +/- 17.8%) than in healthy subjects (16.8 +/- 7.4%), as was CD 62 P expression (8.5 +/- 8.8% vs. 0.88 +/- 0.57%). The increase in PAC-1 expression was correlated with AHI and the arousal index. These findings suggest that activated platelet markers could be good indicators for untreated OSA.

Adult↗
PubMed2002

[Management of myasthenia gravis in association with thymoma].

From June 1975 to March 2002, we experienced 339 patients with myasthenia gravis (MG). Ninety-four patients (81 generalized MG and 13 ocular type) had associated with thymoma. Extended thymectomy including thymoma was performed in all patients. The thymomas were classified as stage I (n = 46), II (n = 31), III (n = 14), and IV a (n = 3). Histopathological findings of the thymoma indicated polygonal cell type in 75 cases, mixture of polygonal and spindle cell type in 14, and spindle cell type in 3, respectively. Three cases in stage II, 12 in III, and 3 in IV a received postoperative radiation therapy. Twenty-two patients required prolonged respirator management for respiratory crisis. Complete remission of MG was seen in 15 cases (17%), and good therapeutic results were obtained in 55 cases (58%) with combined corticosteroid therapy. On the other hand, recurrences of the invasive thymoma were seen in 12 cases (13%), and six of them (6%) died of the tumor. In conclusion, early extended thymectomy including thymoma is markedly effective therapy for MG associated with thymoma, although careful attention should be paid for recurrence of the invasive thymoma.

Adult↗
PubMed2002

[Pericardiectomy for post-coronary artery bypass grafting constrictive pericarditis; strategy for safe and complete pericardiectomy].

Surgery for constrictive pericarditis after coronary artery bypass grafting (CABG) needs complete pericardiectomy without injury to bypass grafts. We performed pericardiectomy for post-CABG constrictive pericarditis 15 months after the first surgery. Preoperative multislice helical 3-dimensional computed tomography (CT) clearly demonstrated the patent bypass grafts and anatomical relationship between grafts and surrounding organs. Among surgical approaches, we chose bilateral thoracotomy to avoid injury to the bypass grafts and to obtain a good surgical exposure, especially for pericardiectomy of the left side of the heart. Additionally, with the use of intraoperative doppler ultrasound blood flowmetry, we could safely achieve complete pericardiectomy. We conclude that the combined application of 3-dimensional CT, bilateral thoracotomy and doppler ultrasound blood flowmetry was a supreme strategy for the operation of constrictive pericarditis after CABG.

Coronary Artery Bypass↗
PubMed2001

Porcine enamel matrix derivative enhances trabecular bone regeneration during wound healing of injured rat femur.

To elucidate the effects of enamel matrix derivative (EMD: Emdogain) on bone regeneration in rat femurs after drill-hole injury, defects in bone were filled with either EMD or its carrier, PGA, as control. On postoperative days 4 to 28, dissected femurs were examined by means of various morphological approaches. In both experimental groups, formation of trabecular bone, which was immunostained for bone sialoproteins (BSP), had occurred in the medullary cavities at cylindrical bone defects on Day 7 postoperatively. Cuboidal osteoblasts were clearly observed on these newly-formed BSP-positive bone trabeculae. On Days 7 and 14, many multinucleated giant cells, which strongly expressed cathepsin K, had appeared on these bone trabeculae, indicating active bone remodeling. In these bone trabeculae, Ca and P weight % and Ca/P ratio were similar to those of cortical bone, and there was no significant difference between the PGA- and EMD-applied groups. Bone volume fraction of newly-formed bone trabeculae on Day 7 postoperatively was significantly higher in the EMD-applied group than in the PGA-applied controls. Because of active bone remodeling and the marked decrease of bone volume, on Days 14 and 28 postoperatively, however, there was no longer a significant difference in trabecular bone volume fraction between the experimental groups. Our results suggest that EMD possesses an osteo-promotive effect on bone and medullary regeneration during wound healing of injured long bones.

Animals↗
PubMed2001

Effects of maternal age on teratogenicity of di-n-butyltin diacetate in rats.

The present study was designed to assess changes in the teratogenic potency of di-n-butyltin diacetate (DBTA) with increasing maternal age in rats. Pregnant Wistar rats of 3, 7.5 or 12 months were treated orally with DBTA at 0, 7.5, 10, 15 or 22 mg/kg on day 8 of gestation. Cesarean sections were performed on day 20 of gestation. Maternal age had greater impact on litter size in the 7.5- and 12-month dams than the 3-month dams. The death of most of the fetuses of the 12-month dams made it difficult to evaluate the teratogenic potency of DBTA. In 3-month groups, fetuses with external malformation, such as cleft mandible, cleft lower lip, ankyloglossia and/or schistoglossia, which are malformations typical of DBTA, were observed at 15 and 22 mg/kg, while similar malformations were observed in 7.5-month groups at doses of 10 mg/kg and above. At 15 and 22 mg/kg, the incidences of these malformations in 7.5-month groups were similar to these from 3-month groups. In our previous studies, however, single DBTA-treatment at 10 mg/kg on day 8 of gestation has not produced such malformations from 3-month dams. The results suggest that the teratogenic potency of DBTA in 7.5-month dams may be greater than in 3-month dams.

Abnormalities, Drug-Induced↗
PubMed2001

Synthetic activity of Sso DNA polymerase Y1, an archaeal DinB-like DNA polymerase, is stimulated by processivity factors proliferating cell nuclear antigen and replication factor C.

DNA replication efficiency is dictated by DNA polymerases (pol) and their associated proteins. The recent discovery of DNA polymerase Y family (DinB/UmuC/RAD30/REV1 superfamily) raises a question of whether the DNA polymerase activities are modified by accessory proteins such as proliferating cell nuclear antigen (PCNA). In fact, the activity of DNA pol IV (DinB) of Escherichia coli is enhanced upon interaction with the beta subunit, the processivity factor of DNA pol III. Here, we report the activity of Sso DNA pol Y1 encoded by the dbh gene of the archaeon Sulfolobus solfataricus is greatly enhanced by the presence of PCNA and replication factor C (RFC). Sso pol Y1 per se was a distributive enzyme but a substantial increase in the processivity was observed on poly(dA)-oligo(dT) in the presence of PCNA (039p or 048p) and RFC. The length of the synthesized DNA product reached at least 200 nucleotides. Sso pol Y1 displayed a higher affinity for DNA compared with pol IV of E. coli, suggesting that the two DNA polymerases have distinct reason(s) to require the processivity factors for efficient DNA synthesis. The abilities of pol Y1 and pol IV to bypass DNA lesions and their sensitive sites to protease are also discussed.

Amino Acid Sequence↗
PubMed2001

Chemoprevention of azoxymethane-induced rat aberrant crypt foci by dietary zerumbone isolated from Zingiber zerumbet.

The modifying effects of dietary feeding of zerumbone isolated from Zingiber zerumbet on the development of azoxymethane (AOM)-induced colonic aberrant crypt foci (ACF) were investigated in male F344 rats. Expression of cyclooxygenase (COX)-2 in colonic mucosa exposed to AOM and/or zerumbone was also assayed. In addition, we assessed the effects of zerumbone on cell proliferation activity of crypts by counting silver-stained nucleolar organizer regions protein (AgNORs) in colonic cryptal cell nuclei. To induce ACF rats were given three weekly subcutaneous injections of AOM (15 mg/kg body weight). They were also fed the experimental diet containing 0.01% or 0.05% zerumbone for 5 weeks, starting one week before the first dosing of AOM. AOM exposure produced 84+/-13 ACF/rat at the end of the study (week 5). Dietary administration of zerumbone caused reduction in the frequency of ACF: 72+/-17 (14% reduction) at a dose of 0.01% and 45+/-18 (46% reduction, p<0.001) at a dose of 0.05%. Feeding of zerumbone significantly reduced expression of COX-2 and prostaglandins in colonic mucosa. Zerumbone feeding significantly lowered the number of AgNORs in colonic crypt cell nuclei. These findings might suggest possible chemopreventive ability of zerumbone, through suppression of COX-2 expression, cell proliferating activity of colonic mucosa, and induction of phase II detoxification enzymes in the development of carcinogen-induced ACF.

Animals↗