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Biomedical subjects

J Shimizu

Publications and source records attributed to J Shimizu.

At least 127 records · Page 7Linked to original sources
PubMed1996

Logistic character of myocardial twitch force curve: simulation.

We found that the isovolumic pressure-time curve of the canine left ventricle closely fitted the difference of two logistic function curves and that the isovolumic relaxation-pressure curve segment was more reliably characterized by a logistic time constant than by the conventional exponential time constant. We therefore hypothesized that the calcium (Ca) transient and the Ca-troponin (Tn) binding and crossbridge (CB) kinetics underlay the logistic character of the ventricular isovolumic pressure curve. We tested this hypothesis with a computer simulation of a simple Ca and CB kinetics model of myocardial isometric twitch force development. We assumed the instantaneous number of attached CBs that was theoretically given as the difference between the cumulative CB attachment and detachment curves. We radically changed the Ca transient, Ca-Tn binding, and CB kinetic parameters. We always found that both the cumulative CB attachment and detachment curves closely fitted logistic functions. The difference curve of these two best-fit logistic functions closely fitted the theoretical F curve with certain combinations of the Ca transient, the Ca-Tn binding, and the CB kinetic parameters. These results seem to support our hypothesis.

Animals↗
PubMed1996

Bcl-2 inhibits retinoic acid-induced apoptosis during the neural differentiation of embryonal stem cells.

We report here that all trans-retinoic acid (RA), a classical morphogen, induces apoptosis during the neural differentiation of the embryonic stem cell line P19. The apoptotic cells showed, in addition to DNA cleavage, typical morphological changes including chromatin condensation, nuclear fragmentation, and cytoplasmic vacuolation. These apoptotic changes became obvious by 12 h after the addition of RA. The endogenous expression of bcl-2 in surviving cells was down-regulated during this process, and the compelled expression of bcl-2 by retroviral vectors reduced the number of apoptotic cells. Apoptosis was partially inhibited by adding antisense oligonucleotides against RA receptors (RARs) simultaneously or by transfecting a plasmid vector flanked with a RA-responsive element. Antisense oligonucleotides against retinoid X receptors (RXRs), the receptors for 9 cis-RA, did not inhibit apoptosis induced by all trans-RA. Cycloheximide and actinomycin D, inhibitors of protein and RNA syntheses, respectively, suppressed apoptosis. No changes were seen in the expression of tumor necrosis factors, their receptors, Fas, FasL, p53, or c-myc, molecules which have been suggested to participate in the apoptotic process. Addition of neurotrophins to the culture medium did not affect apoptosis. These findings suggest that the signals themselves, promote expression of molecules essential for apoptosis. Furthermore, we observed that RA induced apoptosis of cerebral neurons from murine embryos in primary culture, which suggests that RA might participate in cell death which occurs during neural development.

Animals↗
PubMed1996

Primary lipoma of the diaphragm.

Lipoma of the diaphragm is an extremely rare entity. A case of this disease is herein reported, together with the review of the literature. The patient described was a 70-year-old male, who was admitted to our hospital with an abnormal shadow on his chest X-ray film. The primary tumor, located above the left hemidiaphragm, was successfully resected by video-assisted thoracic surgery, and the final diagnosis of lipoma originating in the diaphragm was made.

Aged↗
PubMed1996

A clinicopathologic study of resected cases of adenosquamous carcinoma of the lung.

Adenosquamous carcinoma of the lung is an uncommon form of the lung cancer. Owing to the infrequent occurrence of this disease, no series reported to date (and to our knowledge) has been of adequate size for definitive statistical analysis. In this study, survival curves and background factors affecting prognosis in those with resected adenosquamous carcinoma of the lung were reviewed. In the period from 1973 to 1994, a total of 1,284 patients with primary lung cancer, including 44 cases (3.4%) of adenosquamous carcinoma, were surgically treated in our department. The cumulative 5-year postoperative survival rate, for all cases of adenosquamous carcinoma of the lung was 18.5%. When the survival rates were compared by histologic type, the outcomes of patients with adenosquamous carcinoma were statistically worse than for patients with squamous cell carcinoma and adenocarcinoma, owing to the highly aggressive pathologic stage of adenosquamous carcinoma. The background factors most closely associated with the survival rate in those with adenosquamous carcinoma, using Cox's proportional hazard model, were gender and the degree of nodal involvement. Five-year survival was obtained in seven patients as follows: T1N0M0 in one patient, T2N0M0 in three, T2N1M0 in two, and T3N0M0 in one. Of these seven patients, all had received complete resections, and five were N0 cases. Although our series is small, this study suggest that adenosquamous carcinoma of the lung is an aggressive tumor that grows rapidly.

Adenocarcinoma↗
PubMed1996

Effects of different types of dietary fiber preparations isolated from bamboo shoots, edible burdock, apple and corn on fecal steroid profiles of rats.

This study was conducted to evaluate the effects of different types of dietary fibers (DF) under the conditions with or without cholesterol (Chol) loading on the amount and composition of steroids in rat feces. Rats were fed Chol-unsupplied diets containing 10% lard and 5% DF preparation isolated from four kinds of food, bamboo shoots, edible burdock, apple and corn, for three weeks. The respective diets were supplemented with 0.5% Chol and then given to the rats for a further two weeks. The excretion of total bile acid (BA) and several major BAs increased significantly in the apple group with or without Chol loading when compared with that in the cellulose (CP) or other DF groups. The tendency in the apple group was more noticeable when the diet was supplemented with Chol. This is presumably a major reason for the tendency of decrease in serum and liver Chol concentrations in the apple group. The ratio of secondary BAs to total BA in the feces was significantly low in the apple group. Although the lithocholic acid (LCA)/deoxycholic acid (DCA) ratio, a risk index for colorectal cancer, was significantly lower in the bamboo, burdock and apple groups than in the CP or corn groups when given the diet without Chol, the differences disappeared with the addition of Chol. The proportion of coprostanol, a secondary metabolite of Chol, was smaller in the former three groups than in the CP or corn groups. These results suggest that the intake of some DF by host animals works beneficially for the microbial conversion of BA and Chol in the large intestine but that the addition of Chol acts to cancel such beneficial effects.

Animal Feed↗
PubMed1996

Effects of semi-purified dietary fibers isolated from Lagenaria siceraria, Raphanus sativus and Lentinus edodes on fecal steroid excretions in rats.

Rats were fed diets, each of which contained 5% of the semi-purified dietary fiber (DF) preparations from three kinds of foods, continuously for a total of 7 weeks. The fat level was varied, and cholesterol (Chol) was added toward the end of the experimental period. After 7 weeks, decreases of serum and liver Chol concentrations were observed in the Shiitake (Lentinus edodes) group when compared to the cellulose (CP) group. In the absence of Chol, fecal excretions of several secondary bile acids and total bile acids were affected by the type of DF, showing an increase particularly in the Shiitake group. Total neutral steroid excretions were decreased in the test DF groups compared to the CP group at both fat levels, and were increased by Chol supplementation in all of the test DF groups. It was demonstrated that the effects of the three DF preparations on fecal steroid excretions somewhat differed depending on the dietary factors. In the absence of Chol, the lithocholic acid (LCA)/deoxycholic acid (DCA) ratio was significantly lowered in the test DF groups compared to the CP group by the fat level elevation, and was affected by the interaction of fiber with fat. This ratio responded more intensely to the dietary factors than the two other indices (composition ratios of fecal bile acids). However, this response was lost in the presence of Chol. These results suggest that further studies are warranted to examine if the intense response of the LCA/DCA ratio to the tested DF preparations and fat in the present study will also be shown to other DF and what significance it has in evaluating the function of DF.

Animals↗
PubMed1996

[A clinical analysis of the patients with chest wall reconstruction].

Twenty-three patients underwent chest wall reconstruction in our department. The underlying disease was bronchial carcinoma in 14, urachus tumor in 2, breast cancer in 1, renal cancer in 1, thymic Hodgkin's lymphoma in 1, tuberculosis in 1, fibrosarcoma in 1, and pseudoaneurysm of the aortic arch caused by reconstructed material in 1. An average of 3.4 ribs were resected in 18 patients and sternectomies were performed in 5. Chest wall reconstruction was performed with Marlex mesh in 14, Marlex mesh with methyl methacrylate in 5, Marlex mesh with steel wire in 1, Marlex mesh with omentopexy in 1, Marlex mesh with A-O plate in 1, and net formation with catgut in 1. There was no operative death. Postoperative wound infection occurred in only 1 patient with Marlex mesh cleaned by irrigation and administration of antibiotics. Three patients with Marlex mesh and metyl methacrylate required removal of the prosthetic material postoperatively because of wound infection in 1, seroma in 1, and dislocation of the former reconstructed material in 1. One patient with Marlex mesh and steel wire had protrusion of the wire under the skin and the wire was removed. Eleven patients of lung cancer died at 2-17 months after surgery. In conclusion, chest wall reconstruction with Marlex mesh had excellent results, and chest wall resection and reconstruction for malignancy could be good palliation.

Adult↗
PubMed1996

[A patient with HCC successfully treated by ethanol injection therapy with etoposide].

A patient with hepatocellular carcinoma (HCC) who underwent successfully percutaneous ethanol injection therapy (PEIT) with etoposide was reported. A 72-year-old Japanese man with positive HCV-Ab developed multiple tumors of HCC. He underwent transcatheter arterial embolization (TAE) four times and PEIT three times, but the growth of tumors (particularly, S8) could not be controlled by these modalities. Then, the mixture of etoposide (20 mg), ethanol (8.5 ml) and lipiodol (1.5 ml) was injected into S6 tumors. Consistent with the normalization of serum AFP level, CT scan revealed the marked remaining lipiodol in these tumors. PEIT with etoposide is the treatment of choice in patients with HCC refractory to treatment by conventional TAE or PEIT.

Aged↗
PubMed1996

[Brain monitoring with near infrared spectroscopy during carotid endarterectomy].

We evaluated clinical efficacy of near infrared spectroscopy (NIR) as a monitoring system for cerebral oxygenation during anesthesia for carotid artery endarterectomy. NIR proved to be affected significantly by clamping of the external carotid artery. The present study suggests that this monitoring system may be useful for evaluation of cerebral blood flow following declamping of the internal carotid artery, although it has some limitations during clamping of the artery.

Aged↗
PubMed1996

Direct evidence of the production of IgA by tonsillar lymphocytes and the binding of IgA to the glomerular mesangium of IgA nephropathy patients.

Tonsils were obtained by tonsillectomy from a 33-year-old woman with IgA nephropathy. Hetero-hybridoma cells of human tonsillar B-lymphocytes with mouse myeloma cells (NS-1) were made, and cultured in HAT medium supplemented with 10% fetus bovine serum and hybridoma cloning factor. The culture medium was analyzed by Western blot analysis using anti-human IgA antibody, and both IgA1 and IgA2 were demonstrated to be produced. The specimens of the biopsied kidney tissue of IgA nephropathy were washed with 0.02 M citrate buffer (pH 3.2) to remove deposited IgA from glomerulus. The specimens were then incubated with the culture media of hybridoma cells, and immuno-fluorescence analysis using FITC-conjugated anti-human IgA antibody was performed. IgA deposit was efficiently removed by washing with citrate buffer and was recovered after incubation with the culture medium of hybridoma cells. Direct evidence of binding of IgA produced by tonsillar B-lymphocytes to the glomerular mesangium of IgA nephropathy was demonstrated.

Adult↗
PubMed1996

Significance of vascular endothelial growth factor messenger RNA expression in primary lung cancer.

The expression of mRNAs for vascular endothelial growth factor (VEGF) was examined in 42 cases of primary lung cancer tissues (18 adenocarcinomas, 18 squamous cell carcinomas, 2 large cell carcinomas, 3 small cell carcinomas, and 1 adenoid cystic carcinoma) and 4 human lung cancer cell lines. As seen by reverse transcription-PCR analysis, VEGF mRNAs were expressed predominantly as transcripts for the secretory forms of VEGF (VEGF121 and VEGF165), both in resected lung cancer tissues and in human lung cancer cell lines. The positive ratios of VEGF mRNA according to pathological type were 66.7% (12 of 18) in adenocarcinoma, 72.2% (13 of 18) in squamous cell carcinoma, 100% (2 of 2) in large cell carcinoma, and 67% (2 of 3) in small cell carcinoma. The relative antigen levels of VEGF detected by immunohistochemical examination almost coincided with the relative VEGF mRNA expression levels. Also, we examined the expression of basic fibroblast growth factor mRNA in the same tumor specimens. However, no significant correlation was found between the VEGF and basic fibroblast growth factor mRNA expression levels. We assessed the relationship between the VEGF121 mRNA expression level and the survival period in patients (n = 17) who underwent a curative operation at stage I of the disease. The median survival of the VEGF high-expression group was 8 months, and that of the VEGF low-expression group was 151 months. The 3- and 5-year survival rates of the high-expression group (n = 6) were 50.0% and 16.7%, respectively. On the other hand, those of the low expression group (n = 11) were 90.9% and 77.9%, respectively. The difference in survival between the two groups was significant (P < 0.05). Among eight cases of long-term survival beyond 5 years, seven cases had low or no VEGF121 mRNA expression. In contrast, among 18 cases with VEGF121 mRNA overexpression, 17 cases died due to recurrence. As a marker of tumor angiogenesis, the VEGF121 mRNA expression level may be a significant prognostic indicator of lung cancers in early stages.

Endothelial Growth Factors↗
PubMed1995

Relationship between beta cell injury and antigen presentation in NOD mice.

We have made three observations that are important for our understanding of the dynamics of presentation of diabetogenic Ags in immunologically induced diabetes. First, the APC in the islets of Langerhans were found normally to contain diabetogenic peptides on their I-Ag7 molecules. This was found in freshly harvested islet cells from prediabetic NOD mice and, importantly, from NOD.SCID mice. Second, the presence of diabetogenic lymphocytes improved the presenting function of intra-islet APC. We interpret this to mean that lymphocytes can regulate intra-islet APC function before the development of diabetes. Finally, spleen APC can be found bearing diabetogenic Ag after acute injury to islets. These APC may be important in lymphocyte stimulation outside the environment of the pancreas.

Animals↗
PubMed1995

Clinicopathological study of primary malignant tumors of the lung: an analysis of 993 tumors resected at the Kanazawa University Hospital between 1979-1993.

A retrospective study was conducted of 993 malignant tumors of the lung in 977 patients. The male-female sex ratio was 2.6:1. The age distribution of the males did not differ from that of the females and the overall mean age was 64.3 +/- 9.5 years (range, 13-85 years). Forty-three percent of the patients were in their seventh decade. The location was peripheral in 81% of the tumors and central in 19%. Of the central tumors, 85% were squamous cell (epidermoid) carcinoma (SCC), while 58% of the peripheral tumors were adenocarcinoma (ADENO). In males, 49% of all tumors were SCC and 36% ADENO, while in females 76% were ADENO. The incidence of positive lymph node metastasis increased in parallel with the pT status in both central and peripheral carcinomas. However, it was noted that, of peripheral lung carcinomas, no SCC with a diameter of 15 mm or less had lymph node metastasis, whereas 18.9% of the ADENO of this size were positive for lymph node metastasis. These results indicate that lymph node metastasis can occur even in small-sized peripheral ADENO less than 15 mm. Thus, early detection and surgery together with mediastinal lymph node dissection are necessary even for small-sized tumors to improve the prognosis in patients with peripheral ADENO of the lung.

Adolescent↗
PubMed1995

Results of surgical treatment of pulmonary metastases.

From 1970 to 1993, 155 thoracotomies for metastatic lung tumors were performed on 113 patients in the Department of Surgery, Kanazawa University School of Medicine. Overall 30-day mortality amounted to 0.9% (1/113). The cumulative 3- and 5-year survival rates were 39.4% and 29.1%, respectively. The overall median survival was 24 months. The 5-year survival rate for carcinoma was 37.2% and for sarcoma it was 14.5% (P < 0.01). The other significant predictors of better long-term survival with metastatic lung tumors were solitary lesions, disease-free interval (DFI) > 24 months, and tumor size < or = 20 mm in diameter. There was no significant difference in survival based on the method of pulmonary resection. Repeat thoracotomy for recurrent metastases was performed in 27 patients, whose 5-year survival rate after the first lung resection was 35.5%. For bilateral pulmonary metastases, we recently performed simultaneous bilateral thoracotomy via median sternotomy on 25 patients and transsternal simultaneous bilateral thoracotomy on 8 patients. The latter procedure provides a wide operative field and better survival. We conclude that resection of metastatic lung tumors is safe and effective, and that repeat thoracotomy is warranted in selected patients with recurrent pulmonary metastases.

Adolescent↗
PubMed1995

Cu/Zn superoxide dismutase-like immunoreactivity is present in Lewy bodies from Parkinson disease: a light and electron microscopic immunocytochemical study.

Copper-zinc superoxide dismutase (SOD1)-like immunoreactivity has been demonstrated in Lewy body-like inclusions (LIs) in brain tissues from patients with familial and sporadic amyotrophic lateral sclerosis. Using immunocytochemistry, we studied Lewy bodies (LBs), the original inclusions from which the term LI was derived, in five patients with Parkinson disease (PD). Surprisingly, many LBs were immunostained by an antibody against SOD1. There were two types of staining pattern: a diffuse pattern, and a peripheral pattern with an unstained core. An immunoelectron microscopic study demonstrated that the immunoreactive products were restricted to the fibrillary profiles, sparing the unstructured core. Our results showed that SOD1-like immunoreactivity occurred frequently in LBs and LIs, suggesting that a common cytopathological process is responsible for the formation of LB-type neuronal intracytoplasmic inclusions. Our results also suggest that SOD1 plays a role in the neurodegeneration associated with PD.

Aged↗
PubMed1995

Treatment of multiple primary squamous cell carcinomas of the lung.

BACKGROUND: The prevalence of multiple primary bronchogenic cancers, especially squamous cell carcinoma, has been increasing as a result of improvements in early detection and cancer therapy. MATERIALS: We treated 14 patients with multiple squamous cell carcinoma of the tracheobronchial tree and lung, which corresponded to 2.3% of all squamous cell carcinoma patients undergoing resection. RESULTS: Two patients had peripheral secondary tumors and underwent segmentectomy or partial resection of the lung with good results. The secondary lesions were superficial and minute (less than 5 mm) in 3 patients, and treated with neodymium-yttrium aluminum garnet laser ablation. Five patients had endobronchial tumors of the nodular or polypoid type with suspected deep invasion or invasion extending beyond the bronchial wall based on the bronchoscopic findings. They underwent parenchymal-sparing limited bronchoplasty with excellent results. Three patients had more advanced tumor with massive invasion outside the bronchial wall without lymph node metastases, 1 patient underwent sleeve lobectomy with long survival, and the other 2 patients without operation died of bleeding or had recurrence. One patient with stage IIIA (T2 N2) secondary cancer who underwent lobectomy died 14 months after the second operation. CONCLUSIONS: The surgical treatment of multiple squamous cell carcinoma is justified and limited operation using bronchoplastic techniques provides superior results.

Aged↗