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Biomedical subjects

S Hayashi

Publications and source records attributed to S Hayashi.

At least 145 records · Page 8Linked to original sources

Animal model of axonal Guillain-Barré syndrome induced by sensitization with GM1 ganglioside.

Some humans develop the axonal form of Guillain-Barré syndrome after receiving bovine brain ganglioside. On sensitization with the ganglioside mixture, all of a group of rabbits injected developed high anti-GM1 IgG antibody titers, flaccid limb weakness of acute onset, and a monophasic illness course. Pathological findings for the peripheral nerves showed predominant Wallerian-like degeneration, with neither lymphocytic infiltration nor demyelination. IgG was deposited on the axons of the anterior roots, and GM1 was proved to be present on the axons of peripheral nerves. Sensitization with purified GM1 also induced axonal neuropathy, indicating that GM1 was the immunogen in the mixture. A model of human axonal Guillain-Barré syndrome has been established that uses inoculation with a bovine brain ganglioside mixture or isolated GM1. This model may help to clarify the molecular pathogenesis of the syndrome and to develop new treatments for it.

Animals↗

[A case of papillary adenocarcinoma of the ovary that responded favorably to irinotecan hydrochloride and cisplatin after the administration of paclitaxel and carboplatin].

Recently, the standard treatment for advanced ovarian cancer has changed from CP therapy (cyclophosphamide, cisplatin (CDDP)) to TJ therapy (paclitaxel (TXL), carboplatin (CBDCA)). Irinotecan (CPT-11) is one of the derivatives of camptotecin and has been reported to have a high efficacy for ovarian cancer. In one case of ovarian cancer, chemotherapy was applied with CBDCA and TXL. However, after 2 months of six courses of the chemotherapy, CA-125 was elevated. The elevation of tumor marker levels in serum without the recurrent focus forced us to treat the patient with CPT-11 and CDDP for the second line chemotherapy. Tumor marker levels improved at the beginning of the therapy. In conclusion, CPT-11 and CDDP was effective against the recurrence of ovarian cancer treated with TJ therapy.

Adenocarcinoma, Papillary↗

[A case of micronodular pneumocyte hyperplasia, lymphangiomyomatosis associated with tuberous sclerosis].

We report a case of tuberous sclerosis (TS) associated with renal angiolipomas, subungual fibroma, adenoma sebaceum, pulmonary lymphangiomyomatosis (LAM), and micronodular pneumocyte hyperplasia (MNPH). A CT scan of the chest demonstrated multiple minute nodules present throughout both lung fields. Histologically, the nodules were well demarcated, and were composed of thickened, fibrotic, alveolar septa lined by pleomorphic, type II pneumocytes. This type of MNPH is extremely rare, and appears to be a hamartomatous proliferation occurring in patients with TS.

Adult↗

[A case of desmoplastic malignant pleural mesothelioma].

A 71-year-old woman with no history of asbestos exposure was referred to our hospital for evaluation of mediastinal soft tissue density. Six months prior to the admission, she had developed back pain and had been diagnosed as having intercostal neuralgia. Since the symptoms progressed, she was referred to another hospital. While chest radiography revealed no abnormality, chest computed tomography showed the prominence of mediastinal soft tissue, extending to the left hilum and partially destroying the nearby vertebrae. However, no pleural effusion was noted. After admission, a thoracoscopic examination was performed, and a whitish mass was found on the pleural surface partially adhering to the chest wall. Histological examination of the biopsied material showed dense areas of collagenous tissue with small foci of slightly atypical spindle cells. These findings led to the diagnosis of desmoplastic malignant pleural mesothelioma. The patient was treated with combined chemo-radiotherapy, but the response to this treatment was unclear. To date, reports for this subgroup of malignant mesothelioma are still rare.

Aged↗

Unruptured aneurysm of the right coronary sinus of Valsalva with type B aortic dissection.

A seventy-two year-old man, who complained of severe back pain, was referred to our hospital. Digital subtraction angiogram (DSA) delineated an extracardiac unruptured aneurysm of the right coronary sinus of Valsalva and acute type B aortic dissection. Patch plasty of the right coronary sinus with reimplantation of the right coronary artery using a Dacron graft was performed. Postoperative DSA confirmed successful reconstruction of the aortic root and the patent right coronary artery.

Aged↗

[Dissecting aneurysm of the posterior inferior cerebellar artery--studied by serial angiography].

We report the case of a 34-year-old male with cerebellar hemorrhagic infarction caused by a dissecting aneurysm of the left posterior inferior cerebellar artery (PICA). The patient suffered from a headache and vomiting for two days and was transferred to our hospital with sudden deterioration of consciousness. On admission, he was semicomatose. A CT scan revealed hemorrhagic infarction in the left cerebellum and upward herniation. The emergency operation for posterior fossa decompression was performed. Postoperatively, his consciousness level improved promptly and he had no neurological deficits except for slight gait disturbance. The first vertebral angiography was performed on Day 27. It showed a sausage-like dissecting aneurysm of the left distal PICA. We planned conservative therapy with careful observation because of there being no indication for an operation. Serial angiography was performed and demonstrated the regression of the dissecting aneurysm on Day 258. Dissecting aneurysms of the distal PICA are rare and their natural history is not well understood. Conservative therapy for vertebrobasilar dissecting aneurysms has often been reported. We suggest that conservative therapy with serial angiography is the treatment of choice especially for ischemic-type dissecting aneurysms. We review 17 cases of dissecting aneurysm of the distal PICA in this study.

Adult↗

[Xenon-enhanced CT].

Explore the source record for details and available documents.

Carcinoma, Hepatocellular↗

[Determination of activated platelets: evaluation of methodology and application for patients with idiopathic thrombocytopenic purpura].

Platelet activation causes a change in surface expression of several endogenous proteins, such as CD62P, CD63 and CD40L. Therefore, it is possible to analyze the functional in vivo status of the circulating platelet population directly by flow cytometry. In this study we developed the method to be suitable for use in clinical studies. We used EDTA-2K as anticoagulant since the sample anticoagulated with EDTA-2K, sodium citrate or ACD-A showed no difference in the data of activated platelets. We determined whether fixation of sample is necessary. The samples stained before or without fixation showed abnormally high level of activated platelets, indicating that fixation is necessary before staining. It is controversial whether activated platelets circulate in patients with idiopathic thrombocytopenic purpura(ITP). We measured activated platelets in patients with ITP using our optimised method. The percentages of CD62P, CD63 and CD40L positive platelets were significantly high in patients with ITP and 24%, 55% and 36% (respectively) of ITP patients showed elevated level of activated platelets. These data indicate that activated platelets circulate in ITP patients.

Adult↗

[A case of tuberous sclerosis with pulmonary lymphangiomyomatosis].

A 52-year-old woman complained of exertional dyspnea. She had two sons with tuberous sclerosis and presented with facial angiofibroma and bilateral renal angiomyolipomas. Her chest radiograph demonstrated diffuse reticular shadows and chest CT revealed numerous well-defined cysts outlined by thin walls. Pulmonary lymphangiomyomatosis was diagnosed by transbronchial biopsy that showed multifocal proliferation of immature smooth muscle cells located in the walls of some bronchi, and in alveolar walls and pulmonary vessels. Immunoreactivity for SMA and HMB 45 was present in the same cells, but immunostaining for estrogen and progesterone receptors was negative. Much is still unknown about pulmonary lymphangiomyomatosis and pulmonary involvement in tuberous sclerosis. Further studies, such as gene analysis, will clarify the relationship between these diseases.

Female↗

Clinical studies on the visualization of gastric lesions using virtual CT endoscopy.

OBJECTIVE: We evaluated the clinical usefulness of virtual CT gastroendoscopy (VCTGE). METHODS: The subjects were 124 patients with endoscopically identified gastric lesions. VCTGE images were obtained using a GE-Navigator. We evaluated VCTGE in the visualization of gastric lesions for their presence and morphology. RESULTS: The detection rate of all gastric lesions by VCTGE was 76% (94 of 124 patients). The smallest detectable early gastric cancer was II c measuring 10 x 8 mm. The detection rates of each gastric lesion by VCTGE were 73% in early gastric cancer, and 90% in advanced gastric cancer. VCTGE imaging in the advanced gastric cancer was good in 12 (30%), fair in 25 (60%) and poor in 4 (10%). VCTGE imaging in early gastric cancer was good in 20 (46%), fair in 12 (27%) and poor in 12 (27%). The significance P level was 0.005 between the evaluation of the imaging of advanced and early gastric cancer. CONCLUSIONS: VCTGE visualized the characteristics of diverse gastric lesions and was considered useful for the detection and the diagnosis of these lesions.

Adult↗

Prognostic value of genetically diagnosed lymph node micrometastasis in non-small cell lung carcinoma cases.

The predictive value of lymph node micrometastasis, detected by immunohistochemical or genetic methods, is well appreciated in terms of prognosis. However, a major problem is high false-positive rates, because most methods focus on cytokeratin, which is a component not only of carcinoma but also normal epithelial and nonepithelial cells. Mutant allele-specific amplification (MASA) can detect DNAs derived from cancer cells itself, reportedly with high sensitivity. It was, therefore, used with nested-PCR using p53 or K-ras mutation for analysis of lymph node micrometastasis in non-small cell lung carcinoma (NSCLC) patients in the present study, in comparison with the immunohistochemical method using an anti-cytokeratin reagent for the same samples. Lymph nodes from 31 NSCLC patients with p53 and K-ras mutated tumors (30 and 1, respectively) staged as pathological (p)-T1-4 N0-1 and M0 were examined. Genetic and immunohistochemical methods demonstrated positive reactions in 34 (15%) and 61 (27%) of 229 lymph nodes, respectively (9 cases, 29%, and 24 cases, 77%). The concordance with the two methods was 77%, but 13 (39%) of 34 genetically positive lymph nodes could not be detected by immunohistochemistry (IHC). Of 22 cases with p-N0 disease, 6 (27%) were genetically positive in hilar and/or mediastinal lymph nodes, and 4 (67%) of them died after cancer relapse. In contrast, none of the patients without micrometastasis died of cancer (P < 0.001, log rank analysis). Of the same p-N0 patients, 17 (77%) were positive by IHC, and 4 (24%) of them died of cancer, whereas 5 negative patients did not suffer cancer relapse. Survival did not significantly differ between cases positive and negative (P = 0.246) by IHC. According to the g-N (N factor restaged by a genetic method), patients with g-N1 and g-N2 disease had a shorter survival than those with g-N0 disease (P = 0.042 and P < 0.001, respectively). However, no significant difference was observed with grading by IHC. Thus, detection of micrometastasis in regional lymph nodes with the MASA method, in other words with a carcinoma-specific marker, is of greater prognostic significance for early stage NSCLC patients than immunohistochemical results. This approach should facilitate selection of patients for whom postoperative adjuvant chemotherapy should be performed.

Adenocarcinoma↗

Estrogen-regulated progestin receptors are found in the midbrain raphe but not hippocampus of estrogen receptor alpha (ER alpha) gene-disrupted mice.

Estrogen and progesterone may modulate serotonergic function through intracellular receptors, alpha (ER alpha) and/or beta (ER beta), and the progestin receptor (PR). Studies in macaque and rat suggest species differences in steroid action. Presently, we examined the mouse. To identify whether ER alpha is involved in estrogen induction of PR in midbrain raphe, we studied the ER alpha gene-disrupted (alpha ERKO) mouse. The hippocampus was examined as another estrogen/progestin-sensitive brain area reported to express ER alpha, ER beta, and PR. Female and male homozygous alpha ERKO and wildtype mice were gonadectomized and given estradiol benzoate or vehicle. Dual-label immunocytochemistry was performed for PR or ER alpha and the serotonin-synthesizing enzyme, tryptophan hydroxylase (TPH). Cells exhibiting PR immunoreactivity (PR-ir) or ER alpha-ir were observed in dorsal and median raphe and hippocampus in both sexes. No ER alpha-ir cells were observed in alpha ERKO brains. In raphe, PR-ir or ER alpha-ir often colocalized with TPH-ir. Thus, estrogen and progesterone may directly modulate gene expression in select serotonergic neurons via ER alpha and PR in female and male mice. Estrogen significantly increased the number of PR-ir cells, and the percentage of PR-ir cells colocalizing TPH-ir in both raphe nuclei, regardless of sex and genotype. Although less among alpha ERKO mice, the significant estrogen induction of PRs implicates the involvement of another ER, perhaps ER beta. In hippocampus, distinct estrogen-induced PR-ir cells were observed only in wildtype animals, demonstrating an ER alpha-mediated event in this forebrain region. Collectively, these findings suggest that estrogen can regulate the expression of one gene (the PR) via multiple mechanisms, based upon brain region.

Animals↗

Laparoscopic diagnosis and clinical course of chronic schistosomiasis japonica.

Laparoscopic findings of nine patients with chronic schistosomiasis japonica were analyzed and compared to hepatic ultrasonograms, computed tomography (CT) scans and histological findings from the same patients. In all nine patients laparoscopy revealed yellowish, small speckles, approximately 50 microm in diameter, sparse or clustered over the liver surface, which were later found to represent subcapsular calcified ova of Schistosoma japonicum. While the liver surface was almost smooth in mild schistosomiasis, multiple whitish markings and irregular, relatively wide, groove-like septums were seen in more advanced cases. In severe schistosomiasis block-like formations of variable size, separated by groove-like depressions, made the liver surface appear like a tortoise shell. In moderate or severe schistosomiasis ultrasonography revealed spotted high echoes and CT scans demonstrated network patterns and lineal calcified spots. The liver surface of chronic schistosomiasis japonica without re-infection appeared stable without change over time but with a tendency to improve. Hepatocellular carcinoma was initially recorded in two of the nine patients and follow-up revealed a further two with the same diagnosis. However, all these four cases also had chronic hepatitis C (HCV). Hepatocellular carcinoma was not detected in patients without viral hepatitis, indicating that hepatic viral infection is more important than schistosomiasis in promoting the development of hepatocellular carcinoma.

Aged↗

Increase in cap- and IRES-dependent protein synthesis by overproduction of translation initiation factor eIF4G.

The role of eIF4G during the initiation of protein synthesis was studied using mouse mammary carcinoma FM3A cells and FM4G cells that overproduce an N-terminally truncated form of eIF4G, which lacks the binding site of poly(A)-binding protein. An increase in eIF4G was correlated with an increase in protein synthesis and RNA helicase activity. Translation of mRNAshaving both short and long 5'-untranslated regions (5'-UTR) increased significantly in FM4G cells compared to that in FM3A cells. Both full-length and N-terminally truncated eIF4G transfectants of NIH3T3 cells formed colonies in soft agar and increased the saturation density of cell growth, indicating that both eIF4Gs function similarly. We also found that an internal ribosome entry site (IRES) exists in the 5'-UTR of ornithinedecarboxylase mRNA and that IRES-dependent protein synthesis increased in FM4G cells. Our results indicate that an increase in eIF4G contributes to the formation of active eIF4F similarly to that caused by an increase in eIF4E, as well as to a stimulation of IRES-dependent protein synthesis.

3T3 Cells↗

Roles of P-selectin in inflammation, neointimal formation, and vascular remodeling in balloon-injured rat carotid arteries.

BACKGROUND: P-selectin plays key roles in mediating inflammation through promoting adherence of leukocytes to activated platelets and endothelium. This process is one of the initial events in atherosclerosis and restenosis after coronary angioplasty. METHODS AND RESULTS: Using a rat balloon-injury model, we examined the role of P-selectin in vascular inflammatory processes. In the acute phase, immunohistochemistry revealed that P-selectin was intensely expressed on both activated platelets covering the denuded segment and endothelial cells of the inflamed adventitial small vessels. Treatment with an anti-P-selectin monoclonal antibody (MAb) for 8 consecutive days significantly inhibited neointimal formation at day 14 (42% inhibition; P:<0.05), and this effect persisted at day 56 (40% inhibition; P:<0.01) compared with the control group. Vascular shrinking accompanying adventitial fibrosis was also attenuated at day 56. Inhibition of both neointimal formation and vascular shrinking resulted in the lumen area of the anti-P-selectin treatment group being approximately 3 times larger at day 56 than that of the control group. Accumulation of CD45-positive leukocytes in the developing neointima, media, and adventitia at day 8 was significantly inhibited by treatment with the anti-P-selectin MAb. Scanning electron microscopy demonstrated that anti-P-selectin treatment resulted in a less thrombogenic surface of the arterial intima, which featured a pseudoendothelial appearance at day 14 after injury. CONCLUSIONS: These results suggest that inhibition of P-selectin-mediated leukocyte recruitment prevents the development of neointimal formation, adventitial inflammation, and vascular shrinking and promotes pseudoendothelialization by luminal smooth muscle cells. This treatment thus beneficially affects vascular remodeling after balloon injury in rats.

Angioplasty, Balloon↗