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Biomedical subjects

Y Shimizu

Publications and source records attributed to Y Shimizu.

At least 127 records · Page 7Linked to original sources
PubMed2001

Acute pulmonary thromboembolism with a floating right-heart thrombus. 4 surgical cases.

OBJECTIVE: We determined the efficacy of surgery for acute pulmonary thromboembolism with a floating right-heart thrombus. METHODS AND RESULTS: Thrombi were diagnosed by transthoracic echocardiography and electron beam computed tomography in 4 patients with acute pulmonary thromboembolism with a floating right-heart thrombus, and thromboembolectomy was done in all patients. Surgical procedure included intermittent deep hypothermic circulatory arrest. One patient died of endobronchial hemorrhage and 3 survived. CONCLUSION: Because acute pulmonary thromboembolism with a right-heart thrombus is life-threatening, immediate thromboembolectomy is required to decrease mortality.

Acute Disease↗
PubMed2001

Use of a segment of transverse colon as a gastric substitute after total gastrectomy: an audit of 18 patients.

BACKGROUND: Various types of reconstruction have been employed in attempts to improve the quality of life after total gastrectomy. The use of a jejunal pouch has been the most common approach, and preservation of the duodenal passage has been recommended in several related studies. The aim of the present study was to investigate the benefit of the use of a segment of transverse colon as a gastric substitute. METHODS: Isoperistaltic interposition with a segment of transverse colon was performed after total gastrectomy in 18 patients with gastric malignancies. To clarify the benefits and disadvantages of this technique, a comparison was made between these patients and another 17 patients who underwent jejunal interposition without a pouch. The parameters to be compared included operation time, amount of blood loss, incidence of postoperative complications, and changes in body weight. RESULTS: Postoperative complications were more frequent in the patients reconstructed with the transverse colon, despite a lower incidence of extended lymphadenectomies in this group of patients. No advantage over those treated by the jejunal interposition, in terms of postoperative body weight, was evident during 2 years of follow-up. CONCLUSION: Although it may be too early to draw definite conclusions, there seems to be little benefit in the use of the transverse colon as a gastric substitute.

Carcinoma↗
PubMed2001

Lymph node metastasis in cancer of the middle-third stomach: criteria for treatment with a pylorus-preserving gastrectomy.

A retrospective study was conducted to establish the criteria for performing a pylorus-preserving gastrectomy. This study was performed on 491 patients who had cancer of the middle-third stomach and had been curatively treated with a distal gastrectomy. The incidence of node metastasis for each lymph node station (the group of regional lymph nodes which have been anatomically defined and classified by the Japanese Classification of Gastric Carcinoma) was evaluated with reference to the depth of invasion, tumor size, and circumferential location, to show any significant correlations with an increase in tumor diameter or in the depth of tumor invasion. The benefits of resecting each station was then evaluated based on the incidence of metastasis to each station and the rate of long-term survivors among those with metastasis to each station. The benefit was substantial for the lymph nodes along the lesser curvature, along the right gastroepiploic artery, and at the base of the left gastric artery, while the advantages were almost negligible for the suprapyloric nodes and right paracardial nodes. In conclusion, carcinoma that fulfills either of the following conditions may thus be indicated to undergo a pylorus-preserving gastrectomy: (i) restricted to a depth of m or sml, (ii) a depth of sm2 or mp with a diameter of less than 2cm, (ii) a depth of sm2 or mp and located in the greater curvature.

Adult↗
PubMed2001

Mutations of the PKD1 gene among Japanese autosomal dominant polycystic kidney disease patients, including one heterozygous mutation identified in members of the same family.

More than 80 mutations of the PKD1 gene have been reported, mostly in patients from Western Europe. New techniques are being used to detect an increasing number of mutations, even in the homologous region of the PKD1 gene. Polymerase chain reaction-single-strand conformation polymorphism (PCR-SSCP) or denaturing high-performance liquid chromatography (DHPLC) analyses were performed in the present study to screen mutations from exon 23 to exon 46 in the PKD1 gene and in the entire PKD2 gene. When an abnormal pattern was found in PCR-SSCP or DHPLC, the PCR products were directly sequenced. Four mutations were identified in the PKD1 gene: a missense mutation (C47413T causing T3509M in exon 35), a splicing mutation (del 20bp in 75 bp of intron 43), and two nonsense mutations (C48566A causing C3693X in exon 38, and C51237T causing Q4124X in exon 45). The nonsense mutation Q4124X existed in only two of three affected sib members in family K68. The pattern of the restriction enzyme digest and the haplotype analysis confirmed the presence of a heterozygous mutation in the family. Fifteen single nucleotide polymorphisms were identified in this study. Two of them (C50439A and C51659T) can be used as intragenic polymorphic markers.

Adult↗
PubMed2001

Benefits and limits of hepatic resection for gastric metastases.

BACKGROUND: The significance of hepatic resection for gastric metastases has been controversial. METHODS: Forty consecutive patients undergoing hepatic resection for gastric metastases were reviewed to examine the benefits and the limits of hepatic resection using univariate and multivariate analyses. RESULTS: The overall survival was 27% at 2 years, 18% at 5 years, and 11% at 10 years. Six patients survived more than 5 years. All of the 6 patients underwent anatomical hepatic resection more extensive than segmentectomy, with sufficient resection margin. There were recurrences in 31 patients, and 94% of the recurrences were in the remaining liver. Univariate analysis showed time of hepatic metastases (P = 0.0078) and resection margin (P = 0.024) as significant prognostic factors. Multivariate analysis indicated that only time of hepatic metastases was an independent prognostic factor that influenced survival. CONCLUSIONS: These results suggest that in patients with synchronous metastases we should consider patient selection more strictly, and that in patients with metachronous metastases we should perform anatomical hepatic resection with sufficient resection margin.

Adult↗
PubMed2001

Tracheal allotransplantation in beagle dogs without immunosuppressants.

BACKGROUND: The antigenicity of tracheal grafts is still unclear. We investigated the possibility of performing tracheal allotransplantation without immunosuppressants. METHODS: Intrathoracic five-ring tracheal replacements were performed in beagle dogs without immunosuppressants (n = 18). The dogs were divided into 9 pairs, and grafts were exchanged within the pairs. In group 1 (n = 6), the paired dogs were blood relatives, whereas in group 2 (n = 12), the paired dogs were not related. Full-thickness skin transplantation was also performed in both groups. RESULTS: In group 1, 5 animals survived uneventfully for more than 3 months. No stenosis was observed in any of the dogs. In group 2, the grafts were incorporated by the host trachea in 2 dogs. Four animals died of airway obstruction within 3 months. Moderate or slight airway stenosis was observed in 6 dogs. Rejection was confirmed by histologic examination. In both groups, all of the skin allografts were destroyed within 2 weeks. CONCLUSIONS: After tracheal allotransplantation, long-term survival was achieved, especially in recipient dogs that were blood relatives of donors. We conclude that it is possible to perform tracheal allotransplantation using histocompatible matched grafts without immunosuppressants.

Animals↗
PubMed2001

Localization and expression of steroid sulfatase in human fallopian tubes.

Localization of steroid sulfatase, a membrane-bound microsomal enzyme, in human fallopian tubes was immunohistochemically investigated, and expression of RNA was confirmed by competitive RT-PCR. Human fallopian tubes were obtained from 10 patients in follicular and early luteal phases during gynecological laparotomy. An anti-human rabbit polyclonal antibody was prepared against sulfatase protein purified from human placenta. Total RNA was isolated from epithelium of fallopian tubes. A heterologous RNA competitor was designed, and competitive RT-PCR was carried out. Steroid sulfatase was localized to the cytoplasm of epithelial cells. With respect to the positive staining of cells, the number of positive secretory cells was higher than that of ciliated cells. A significantly higher number of positive cells was found in tissue obtained from the early luteal phase than that found in tissue from the follicular phase. An abundant expression of sulfatase mRNA in early luteal phase was also observed. This study demonstrates, for the first time, that steroid sulfatase is localized to human epithelial cells and that steroid sulfatase staining and mRNA expression changes with the menstrual cycle. These results suggest that sulfatase in the fallopian tube may be involved in controlling the local steroid environment, which appears to regulate aspects of the physiological reproductive function of the fallopian tube.

Adult↗
PubMed2001

Development of a new calcium phosphate cement that contains sodium calcium phosphate.

A cement powder consisting of sodium calcium phosphate, Na3Ca6(PO4)5, in addition to tetracalcium phosphate and beta-tricalcium phosphate was prepared by pulverizing blocks of 4 wt% sodium-, 11 wt% carbonate-containing apatite samples that were heated at 1700 degrees C for 5 h. When mixed with 30 wt% malic acid or citric acid at a powder liquid ratio of 3:1, the cement set in 3 or 7 min at room temperature with compressive strength being around 52 or 27 MPa. In HeLa-cell cultures, the cement mixed with malic acid was less cytotoxic than the cement mixed with citric acid, which was far less cytotoxic than a commercial carboxylate cement used as a negative control, suggesting malic acid to be superior to citric acid as a liquid in this regard. Similar findings were also obtained with osteoclasts, of which culture experiments clearly suggested that the number of osteoclasts on the cement mixed with malic acid was significantly greater than that on the cement mixed with citric acid. Since osteoclastic response to substrates could be used as a maker in evaluating their bioresorbability associated with osteoclasts, the above finding may suggest that the cement that is to be mixed with malic acid would be more useful as bone substitutes.

Animals↗
PubMed2001

Mechanical properties of artificial tracheas composed of a mesh cylinder and a spiral stent.

Much work has been done on the materials used for mesh-type artificial tracheas, but a precise mechanical evaluation of these structures has not yet been performed. In the present study, we determined the mechanical properties of typical mesh-type artificial tracheas and compared them with those of native trachea. Four types of artificial trachea were made and used for the mechanical tests. The basic frame of all the specimens was composed of a mesh cylinder and a spiral stent. The specimen whose mesh was sealed with collagen sponge showed almost the same behavior in the force-strain curve under compression, suggesting that collagen sealing has little effect on mechanical properties. Agreement between measured and estimated mechanical properties was good, especially in the low strain region, suggesting that artificial tracheas can be designed in terms of mechanical properties by mainly considering the basic frame structure.

Animals↗
PubMed2001

A highly selective inhibitor of Rho-associated coiled-coil forming protein kinase, Y-27632, prolongs cardiac allograft survival of the BALB/c-to-C3H/He mouse model.

BACKGROUND: Current studies provide evidence that a small G protein, RhoAp21, and its target protein, Rho-associated coiled-coil forming protein kinase (ROCK), regulate not only cell shape but also cell migration. However, contribution of Rho/ROCK signaling to graft rejection is unknown. The purpose of this study was to evaluate the inhibitory effect of Y-27632, a highly selective ROCK inhibitor, on rejection of heterotopic cardiac transplantation in mice. METHODS: BALB/c (H-2(d)) hearts were transplanted into C3H/He (H-2(k)) as allografts that were full histoincompatibility combinations. The recipients received several doses of Y-27632, commencing 1 day before cardiac transplantation until rejection. We used immunohistochemical study to detect the expression of myocardial intercellular adhesion molecule 1 (ICAM-1) and vascular cell adhesion molecule 1 (VCAM-1), and we immunoenzymatically measured serum interleukin (IL)-6. Furthermore, we evaluated cardiac allograft vasculopathy treated with either FK506 or Y-27632 at Day 100. RESULTS: The Y-27632-treated (2 mg/kg/day) allografts prolonged the mean survival time (49.6 +/- 10.1 days, n = 12) as compared with the untreated allografts (8.1 +/- 0.4 days, n = 7, p < 0.001). Histologic examinations of the Y-27632-treated allografts at Day 7 showed greatly reduced leukocyte infiltration compared with the untreated allografts. The Y-27632-treated allografts revealed faint expression of myocardial ICAM-1 and VCAM-1 at Day 7. The serum IL-6 levels also decreased in the Y-27632-treated mice. In the long-surviving Y-27632-treated allografts at Day 100, we saw neither active rejection nor apparent thickening of vascular intima. CONCLUSION: Our results suggest that ROCK plays a major role in cardiac rejection in the BALB/c-to-C3H/He mouse model. Inhibition of this Rho/ROCK signaling may be an alternative therapeutic option for managing acute and chronic rejection.

Amides↗
PubMed2001

Regulation of the PH-domain-containing tyrosine kinase Etk by focal adhesion kinase through the FERM domain.

Etk/BMX, a member of the Btk family of tyrosine kinases, is highly expressed in cells with great migratory potential, including endothelial cells and metastatic carcinoma cell lines. Here, we present evidence that Etk is involved in integrin signalling and promotes cell migration. The activation of Etk by extracellular matrix proteins is regulated by FAK through an interaction between the PH domain of Etk and the FERM domain of FAK. The lack of Etk activation by extracellular matrix in FAK-null cells could be restored by co-transfection with wild-type FAK. Disrupting the interaction between Etk and FAK diminished the cell migration promoted by either kinase. Furthermore, inhibiting Etk expression in metastatic carcinoma cell lines with an antisense oligonucleotide blocks integrin-mediated migration of these cells. Taken together, our data indicate the essential role of the interaction of the PH domain of Etk and the FERM domain of FAK in integrin signalling.

Animals↗
PubMed2001

Cell-free translation reconstituted with purified components.

We have developed a protein-synthesizing system reconstituted from recombinant tagged protein factors purified to homogeneity. The system was able to produce protein at a rate of about 160 microg/ml/h in a batch mode without the need for any supplementary apparatus. The protein products were easily purified within 1 h using affinity chromatography to remove the tagged protein factors. Moreover, omission of a release factor allowed efficient incorporation of an unnatural amino acid using suppressor transfer RNA (tRNA).

Amino Acids↗
PubMed2001

Black tea extract, thearubigin fraction, counteract the effects of botulinum neurotoxins in mice.

Botulinum neurotoxin type A (BoNT/A, 1.5 nM) completely inhibited indirectly evoked twitches in in vitro mouse phrenic nerve-diaphragm preparations within 40 - 45 min. Black tea extract, thearubigin fraction (TRB), mixed with BoNT/A blocked the inhibitory effect of the toxin. The protective effect of TRB extended to botulinum neurotoxins types B and E (BoNT/B and BoNT/E) and tetanus toxin, but not to tetrodotoxin. TRB was also effective against oral toxicity of BoNT/A, B and E. Thus, TRB may be of potential benefit in protecting the paralytic actions of botulinum neurotoxins (BoNTs), but its use is limited by mixing with the toxin.

Animals↗