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Biomedical subjects

T Sawada

Publications and source records attributed to T Sawada.

At least 289 records · Page 16Linked to original sources

Measuring the anterior capsule opening after cataract surgery to assess capsule shrinkage.

PURPOSE: To measure anterior capsule opening (ACO) size after acrylic intraocular lens (IOL) implantation and study the natural course of ACO reduction. SETTING: Kimura Eye and Internal Medicine Hospital, Hiroshima, Japan. METHODS: This study comprised 32 patients (38 eyes) having continuous curvilinear capsulorhexis, phacoemulsification, acrylic IOL implantation, and a self-sealing incision performed by 1 surgeon. A retroillumination photograph of the ACO was obtained with the Anterior Eye Segment Analysis System and converted to a computer image. The images were used to measure ACO size postoperatively and calculate the reduction ratio. Follow-up was 6 months. RESULTS: The postoperative reduction ratio in ACO size was 2.14% at 1 week, 3.83% at 1 month, 4.29% at 3 months, and 5.03% at 6 months. In a few cases, the reduction was progressively severe throughout the follow-up. CONCLUSIONS: The anterior capsule opening shrank rapidly during the first month after acrylic IOL implantation, followed by a slower progressive reduction in the subsequent 6 months. When severe, progressive shrinkage occurs, an anterior neodymium:YAG laser capsulotomy should be performed within 2 months postoperatively.

Acrylic Resins↗

Long-term follow-up of primary anterior chamber intraocular lens implantation.

PURPOSE: To evaluate the long-term outcome in eyes having primary anterior chamber intraocular lens (AC IOL) implantation. SETTING: Kimura Eye and Internal Medicine Hospital, Hiroshima, Japan. METHODS: Primary AC IOL implantation was performed in 171 eyes from 1983 to 1988. Two lenses were implanted: the open C-loop Simcoe lens and the 4-point fixation Kelman lens. In 86 eyes that had a mean follow-up of 9 years 7 months, visual acuity, corneal endothelial cell density, pupil shape, and the presence of associated complications were examined. RESULTS: Although the final visual acuity was 0.5 or better in 60 eyes (69%), corneal endothelial cell density was less than 2000 cells/mm2 in 46 eyes (57%). Postoperative complications included a deformed pupil in 48 eyes (56%) and bullous keratopathy in 12 eyes (14%). In 14 eyes the AC IOL was explanted; 11 of these were the open C-loop Simcoe lens. CONCLUSION: Although our findings show that the open C-loop AC IOL (Simcoe) is contraindicated, implantation of the 4-point fixation AC IOL may be acceptable in selected cases.

Aged↗

Clinical study on localization-related epilepsy in infancy without underlying disorders.

A clinical study of 15 patients without underlying disorders whose first seizures occurred before 1 year of age was performed to determine the characteristics of localization-related epilepsies in infancy. The patients were retrospectively divided into two groups: the seizure-controlled group (10 patients) and the refractory group (five patients). The seizure-controlled group included patients whose seizures were controlled completely within 1 year after onset; the refractory group included all other patients. The characteristics of the refractory group were as follows: (1) interictal electroencephalography showed focal abnormalities, particularly on the left side, and (2) all of the patients exhibited developmental retardation. Even in the seizure-controlled group, 40% of the patients exhibited developmental retardation, and all of them were indistinguishable from patients with benign complex partial epilepsies in infancy at the onset of the seizures. Aggressive treatment should be re-evaluated for early-onset localization-related epilepsies.

Anticonvulsants↗

Arginine vasopressin stimulates phospholipid methylation in cultured rat mesangial cells: possible role for PGE2 production.

Incorporation of [3H-methyl] groups into phospholipids and prostaglandin E2 (PGE2) production in cultured rat mesangial cells were examined in the presence and absence of arginine vasopressin (AVP). In cells stimulated with AVP, a rapid increase in the incorporation of [3H-methyl] group into phospholipids was observed within 1 min after stimulation. The [3H-methyl] group present in the phospholipids began to decline 2.5 min after stimulation. The production of PGE2 increased with AVP treatment, and the decline in methylated phospholipids paralleled the release of PGE2 in AVP-stimulated cells. The inhibition of phospholipid methylation by treatment with adenosyl-S-isobutyl mercaptan (SIBA) resulted in a marked decrease in AVP-stimulated PGE2 production. In order to determine the identity of the methylated phospholipids, [3H-methyl] incorporation into phosphatidylethanolamine derivatives was examined. In AVP-stimulated cells, an increase of [3H-methyl] labeled phosphatidylcholine and lysophosphatidylcholine was observed after stimulation with AVP, followed by an apparent increase of [3H-methyl] labeled lysophosphatidylcholine. These findings indicate that AVP stimulates phospholipid methylation in cultured rat mesangial cells and phosphatidylcholine, synthesized by a transmethylation pathway, may be a source for PGE2 production.

Animals↗

Establishment of lymph node metastatic model for human gastric cancer in nude mice and analysis of factors associated with metastasis.

The actual mechanisms responsible for lymph node metastasis in gastric cancer are still unclear. To investigate the mechanisms of lymph node metastasis in gastric cancer, we established a lymph node metastatic model for human scirrhous gastric carcinoma. Lymph node metastasis had frequently developed after orthotopic implantation of OCUM-2M LN derived from a scirrhous gastric cancer cell line, OCUM-2M, which had low capacity for lymph node metastasis. We elucidated the different characteristics including binding ability, migratory capacity and immunoresponses induced by the cell surface molecules of these two cell lines. The binding ability to Matrigel and migratory capacity of OCUM-2M LN cells were significantly greater than those of OCUM-2M cells. On flow cytometric analysis, both OCUM-2M and OCUM-2M LN cells strongly expressed HLA-I (99.5 and 97.1%) and LFA-3 (76.6 and 99.2%) in level of expression between the two cell lines, but neither cell line expressed HLA-II (0.0 and 0.0%), B7-1 (0.0 and 0.0%) or B7-2 (0.4 and 0.3%). ICAM-1 expression in OCUM-2M LN cells was weaker (0.7%) than that in OCUM-2M cells (36.8%). Strong adhesiveness and cytotoxicity of mononuclear lymphocytes for OCUM-2M cells were observed in adhesion and cytotoxic assays, both of which were significantly decreased by the addition of anti-ICAM-1 antibodies. On the other hand, the adhesiveness and cytotoxicity of OCUM-2M LN cells were significantly less than those of OCUM-2M cells, and were not affected by the addition of anti-ICAM-1 antibodies. These findings suggest that decreased ICAM-1 expression in a new gastric cancer cell line with a high rate of lymph node metastasis may in turn decrease immune responses mediated through LFA-1-dependent effector cell adhesion, and that this escape from the immunosurveillance system may be one of the factors inducing lymph node metastasis. In conclusion, we established a gastric cancer cell line, OCUM-2M LN, with a high rate of lymph node metastasis. An in vivo lymph node-metastatic model with this cell line should be useful for analysing the mechanism and therapeutic approach of lymph node metastasis.

Adenocarcinoma, Scirrhous↗

Adhesion polypeptides are useful for the prevention of peritoneal dissemination of gastric cancer.

We examined the effect of adhesion polypeptides on the adhesion and invasiveness of gastric cancer cell lines. We previously reported the establishment of an extensively peritoneal-seeding cell line, OCUM-2MD3, from a poorly seeding human scirrhous gastric carcinoma cell line, OCUM-2M. Both alpha2beta1 and alpha3beta1 integrin expression was markedly increased on OCUM-2MD3 cells compared with OCUM-2M cells, and the ability of OCUM-2MD3 cells to bind to the extracellular matrix (ECM) was also significantly higher than that of OCUM-2M cells. The adhesion polypeptides, YIGSR and RGD, and two RGD derivatives significantly inhibited the adhesion of OCUM-2MD3 cells to the submesothelial ECM, while not inhibiting the adhesiveness of OCUM-2M cells and two well differentiated human gastric cell lines, MKN-28 and MKN-74. The YIGSR and RGD peptides also significantly inhibited the invasiveness of OCUM-2MD3 cells. The survival of nude mice with peritoneal dissemination given YIGSR sequence intraperitoneally was obviously longer than that of untreated mice. The survival of mice treated with RGD was also improved, and this effect was increased using the RGD derivatives, poly(CEMA-RGDS) and CM-chitin RGDS. These polypeptides appear to block the binding of integrins, which are expressed on OCUM-2MD3 cells, to the submesothelial ECM, and consequently inhibit peritoneal implantation. The peritoneal injection of adhesion polypeptides may be a new therapy against the dissemination of scirrhous gastric cancer, and may be useful for the prevention of dissemination in high-risk patients.

Adenocarcinoma, Scirrhous↗

Serum soluble interleukin-2 receptor level as a prognostic indicator in gastric cancer.

T lymphocytes, activated by interleukin 2 during an anti-tumour response, release soluble interleukin 2 receptors (sIL-2R) into the bloodstream. We analysed the prognostic value of the serum sIL-2R level in gastric cancer. Serum concentration of sIL-2R in 96 gastric cancer patients and 100 healthy control subjects' was measured by enzyme-linked immunosorbent assay. All survivors were followed for more than 50 months. Serum sIL-2R level was considered with respect to prognosis, clinicopathological factors, other tumour markers and peripheral blood cell count. Stage III and IV patients had significantly higher sIL-2R levels than lower stage patients and control subjects. Stage III and IV gastric cancer patients were divided into 'high' and 'low' slL-2R groups based upon the control subjects' serum sIL-2R mean value plus one standard deviation. The high group had a significantly worse prognosis than the low group, although clinicopathological features and treatments were similar. Multivariate analysis demonstrated that the serum sIL-2R level is an independent indicator. The sIL-2R level did not correlate with carbohydrate antigen 19-9, however it did correlate with carcinoembryonic antigen (r = 0.22) and with numbers of peripheral blood monocytes (r = 0.54). In conclusion, serum sIL-2R may predict the outcome of gastric cancer patients with stage III or IV disease.

Adult↗

Donor lymphocyte infusion at unstable mixed chimerism in an allogeneic BMT recipient for chronic granulomatous disease.

We report a 14-year-old boy who had successfully received allogeneic BMT for chronic granulomatous disease and 3 years later was treated with donor lymphocyte infusion (DLI, 3.3 x 10(8) cells/kg) at unstable mixed chimerism in association with reduced neutrophil function. Following DLI, the patient developed transient acute hepatic GVHD, which was confirmed by liver biopsy and was manageable with cyclosporin A and prednisolone. The patient eventually attained complete chimerism with improved neutrophil function. At the time of writing (2.5 years from the DLI), the patient is doing well, free from infectious episodes and chronic GVHD. Our experience suggests that DLI could be a safe and effective strategy for dissolution of unstable mixed chimerism in BMT recipients for inherited disorders.

Adolescent↗

A novel single cell PCR assay: detection of human T lymphotropic virus type I DNA in lymphocytes of patients with adult T cell leukemia.

The abnormal lymphocytes in adult T cell leukemia (ATL) reveal a peculiar morphology that is characterized by indented or lobulated nuclei. While human T lymphotropic virus type I (HTLV-I) is thought to be integrated in ATL cells, the correlation between the nuclear irregularities and HTLV-I infection is obscure. We have devised a novel single cell polymerase chain reaction (PCR) technique to examine the integration of HTLV-I provirus genome in cells from two patients with ATL. To isolate single cells, peripheral blood smears were prepared on thin polyester slides and stained with May-Grünwald-Giemsa. Morphologically defined single cells were cut out after light microscopy. The HTLV-I DNA sequences were detected not only in ATL cells but also in normal-looking lymphocytes. This novel PCR method may provide a valuable tool for understanding the molecular events associated with HTLV-I infection at the single cell level.

Adult↗

Deleted HTLV provirus in peripheral blood cells of a patient with T-cell prolymphocytic leukaemia.

We describe the first case of T-cell prolymphocytic leukaemia (T-PLL) in which the peripheral blood cells contained a human T-lymphotropic virus (HTLV) related tax sequence. Serum screening tests for anti-HTLV-I/II antibodies were negative. Polymerase chain reaction disclosed the presence of an HTLV-I tax sequence in the peripheral blood. Other sets of oligonucleotide primers for HTLV-I gag, pol, env and the long terminal repeat regions and for the HTLV-II pol region were negative in the DNA of the cells. Although patients with T-PLL have been reported to be seronegative for HTLV-I, our findings point to the possibility that HTLV-I infection might be involved in the aetiology of at least some cases of T-PLL and that there may be alternative mechanisms involved in HTLV-associated leukaemogenesis.

Base Sequence↗

Immunohistochemical examination of NOS and SOD in nasal mucosa.

An immunohistochemical examination was performed to detect the localization of neural-type nitric oxide synthase (nNOS), endothelial-type NOS (eNOS) and inducible-type NOS (iNOS) in the human and mouse nasal mucosa. nNOS-immunoreactive nerve fibers were found in the subepithelial layer and around the seromucous glands of mice. In these fibers, immunodouble staining revealed co-localization of nNOS and superoxide dismutase (SOD). In the human nasal mucosa of normal subjects, strong eNOS immunoreactivity and weak iNOS immunoreactivity were found in the columnar epithelium.

Animals↗

Pure red cell aplasia and myasthenia gravis with thymoma: a case report and review of the literature.

A case of pure red cell aplasia (PRCA), myasthenia gravis (MG) and thymoma is reported. A 70-year-old woman presented with severe anemia. She had been diagnosed as having MG 8 years earlier and her symptoms were adequately controlled with ambenonium chloride. When she visited our hospital, her hematocrit was 13.7% with a hemoglobin concentration of 4.7 g/dl and her reticulocyte counts were persistently abnormal at 0.1%. Although both direct and indirect Coombs' tests were positive, there was no evidence of hemolysis. Routine screening tests for other etiologies of anemia were negative. Serological tests for anti-DNA and anti-acetylcholine receptor antibodies gave positive results. A bone marrow examination revealed severe erythroid hypoplasia. PRCA was diagnosed and the patient was treated with periodic transfusions. A lateral view chest roentgenogram and a computed tomography scan of the thorax showed the presence of an anterior mediastinal mass which was suspected to be thymoma. The patient underwent thymothymectomy and the tumor was diagnosed as a thymoma. Although the patient received no treatment for MG and PRCA after surgery, her hematological test results rapidly improved and she was discharged from the hospital on the 29th postoperative day. At that time, her hematocrit was 33.2%, her hemoglobin concentration was 10.0 g/dl, her peripheral reticulocyte level was 1.8% and her left partial ptosis had improved. She is doing well, 9 months after surgery. For a patient to remain in remission without treatment for PRCA and MG after thymothymectomy is extremely rare.

Aged↗

First International Pharmacoeconomic Conference on Alzheimer's Disease: report and summary.

The First International Pharmacoeconomic Conference on Alzheimer's Disease (AD) was held in Amsterdam in July 1998. The meeting was held under the auspices of the International Working Group for Harmonization of Dementia Drug Guidelines (http://dementia.ion.ucl.ac.uk/harmon), bringing together academics, clinicians, purchasers, and representatives from industry. Presentations were given on the methodology of pharmacoeconomic studies in AD, particularly focusing on caregiver burden, quality of life (QOL), and resource utilization. Three economic models of AD were presented based on data from the United States, Canada, and the United Kingdom. In two studies, these data were then used to model the cost-effectiveness and effect on cost of treatment with donepezil. Both studies suggested a possible cost advantage for the use of donepezil, when compared with no placebo or treatment, particularly when donepezil is used appropriately in mild-to-moderate AD. These data need to be interpreted with care, as none of the cost or utility information were collected during the clinical trials. Additional data from a 2-year clinical trial of selegiline and vitamin E suggest that cognitive measures may be poor predictors of economic outcome, which is better measured directly. Both economic models of donepezil rely on short-term cognitive data to predict long-term outcome, a methodf that may not be useful in predicting economic savings. The issues facing pharmacoeconomists, researchers, clinicians, and families in the future were addressed in a series of workshops using a method of strategic futuring. The workshops attempted to see 7 years into the future for a range of areas, including consumer and caregiver use of pharmacoeconomic data; early detection and prevention; Japanese perspectives; activities of daily life and what will be daily life activities; caregiver burden; QOL at the end of life; new uses for new information and communication technology in clinical research; and physicians' use of pharmacoeconomic data. A range of exciting futures were predicted, although common themes that arose when considering barriers to achieving these futures included cost, education, political will, confidentiality, privacy, and ethics. The first conference was deemed to have been a success, having attracted more than 160 delegates and many distinguished speaker. A second conference is planned for the year 2000. Over the next 2 years, research needs to be broadened particularly in the methodological areas of resource utilization, QOL, and caregiver burden. Data from clinical trials with relevant economic and QOL outcomes will be needed by purchasers if drug treatments for dementia are to gain widespread use. It is also hoped that the models described at the meeting may become more freely available to politicians, purchasers, clinicians, and caregivers to help them make better decisions about treatment.

Aged↗

Provirus load in patients with human T-cell leukemia virus type 1 uveitis correlates with precedent Graves' disease and disease activities.

We previously demonstrated the increased provirus load in the peripheral blood of patients with human T-cell leukemia virus type 1 (HTLV-1) uveitis (HU). To delineate the relevance of the increased provirus load to clinical and immunologic parameters, we studied the correlation between them. Seventy-nine HU patients (24 male and 55 female) were included in the study, with their informed consent. Plasma samples and genomic DNA of the peripheral blood mononuclear cells were isolated and the provirus load was estimated by semi-quantitative polymerase chain reaction of the gag region sequence. Serum levels of anti-HTLV-1 antibodies and soluble IL-2R were determined by electrochemiluminescence immuno assay and by ELISA, respectively. Disease activities were assessed and graded 0 to 4 according to the evaluation system. Recurrence of the disease during the follow-up period was diagnosed ophthalmologically. The provirus load was significantly higher in the HU patients after Graves' disease (GD) than in those without GD (P<0.05). It correlated with disease activities assessed in terms of vitreous inflammation and interval to recurrence (both P<0.05). In the HU patients without GD, it correlated with the serum levels of soluble IL-2 receptor (P<0.01), and nearly with those of HTLV-1 antibody (P=0.063). These correlations were not found in the HU patients after GD under methimazole treatment. The results suggested a direct involvement of HTLV-1-infected cells in the pathogenesis of uveitis, and raise the possibility that hyperthyroidism may contribute to the clonal expansion of HTLV-1-infected cells.

Graves Disease↗

Vascular endothelial growth factor and neovascularization in astrocytic tumors.

It has been widely recognized that the vascular structure is an important factor when making a histopathological diagnosis and assessing the malignancy potential, especially of astrocytic tumors. The vascular endothelial growth factor (VEGF), which is thought to be regulated by the p53 gene, is a regulation factor for tumor neovascularization. The relationship between VEGF distribution and neovasculature was studied in 42 cases of astrocytic tumors (grades 1-4), which were obtained from surgical material, and the St Anne-Mayo grading system was applied. The relationship between the labeling indices (LI) of VEGF and LI of p53 protein in tumor cells was also studied using immunohistochemistry. The VEGF LI in high-grade malignancy potential tumors, such as grade 3 and grade 4 tumors, was significantly higher than those that were low grade. In grade 4 tumors, a significant correlation between the VEGF LI and the proliferation indices of endothelial cells of neovasculatures was observed. No significant correlation was noted between p53 LI and VEGF LI, as well as p53 LI and histopathological grade. In astrocytic tumors, expression of VEGF may be correlated to tumor neovascularization, and can be considered as an indicator of malignancy potential in astrocytic tumors.

Adolescent↗