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Biomedical subjects

M Sakaguchi

Publications and source records attributed to M Sakaguchi.

At least 505 records · Page 28Linked to original sources
PubMed1976

[Aneurysm of the great vein of Galen--report of a case (author's transl)].

A case of aneurysm of the great vein of Galen was reported in which craniotomy and clipping of a feeding artery arising from the left posterior cerebral artery was successfully performed. This 5-month-old girl developed progressive hydrocephalus from 2 months after birth. At 5 months the head circumference was 50 cm with tense enlarged fontanelle. Both eye balls were deviated downward. The deep tendon reflexes were hyperactive with bilateral ankle clonus and positive Babinski's sign. Mild cardiomegaly and hepatomegaly were also noted. Cerebral angiograms showed a large aneurysm of the great vein of Galen fed by a single enlarged arterial branch from the left posterior cerebral artery. After the evaluation of systemic circulatory status and under strict control of fluid transfusion craniotomy was performed. The feeding artery was clipped at its entrance to the aneurysm via left parieto-occipital interhemispheric approach. A rise in the mean arterial blood pressure of 20 mmHg was observed immediately following clipping. The postoperative course was satisfactory except for a left subdural fluid collection which required subduro-peritoneal shunt. The aneurysm was completely disappeared on the postoperative angiograms and the child is regaining the normal development. This is the first case of aneurysm of the great vein of Galen successfully operated in Japan. Clinical symptoms and signs, radiological features and operative treatment of the disease were reviewed from a total of 46 cases reported in the world literature.

Brain↗
PubMedDate not supplied

Cytokine production by T cells infiltrating in the eye of uveitis patients.

The capacity of T cells to produce cytokines was investigated using T-cell clones (TCCs) established from infiltrating cells in the aqueous humor (AH) or peripheral blood mononuclear cells (PBMC) of patients with Vogt-Koyanagi-Harada (VKH) disease or sarcoidosis. The cytokines produced and tested in the study were interleukin (IL)-1alpha, IL-6, IL-8, interferon (IFN)-gamma, tumor necrosis factor (TNF)-alpha, and granulocyte monocyte colony stimulating factor (GM-CSF). All TCCs (n = 9) from AH of VKH patients spontaneously produced significantly larger amounts of IL-6, IL-8, and IFN-gamma than TCCs from healthy donor PBMC. All TCCs (n = 9) from AH of the sarcoidosis patient spontaneously produced significantly larger amounts of IL-1alpha, IL-6, and IL-8 than TCCs from healthy donor PBMC. In addition, the effects of antiinflammatory drugs on the cytokine production by the TCCs were investigated. Hydrocortisone significantly suppressed the production of IL-6, IL-8, and GM-CSF by TCCs from AH of VKH patients. Tacrolimus also significantly suppressed the production of IL-8 and GM-CSF by the TCCs. FTY720, an experimental drug, suppressed only GM-CSF production by TCCs from AH of VKH patients. Diclofenac failed to suppress the production of any cytokines by any TCCs. All tested drugs did not suppress the production of cytokines by TCCs from the sarcoidosis patient. These results thus suggest that cytokines produced by T cells infiltrating in the eye may play an important role in the pathogenesis of uveitis.

Adult↗
PubMedDate not supplied

Measurement of activities in two different angiotensin II generating systems, chymase and angiotensin-converting enzyme, in the vitreous fluid of vitreoretinal diseases: a possible involvement of chymase in the pathogenesis of macular hole patients.

PURPOSE: To investigate possible involvement of chymase and angiotensin-converting enzyme (ACE) in the pathogenesis of vitreoretinal diseases, both of which are related to the production of angiotensin II. METHODS: We measured chymase and ACE activities in the vitreous in the 54 affected eyes of 54 patients who had undergone vitreous surgery for idiopathic macular holes (MH, n = 14), proliferative diabetic retinopathy (PDR, n = 14), idiopathic epiretinal membranes (ERM, n = 13), and rhegmatogenous retinal detachment (RRD, n = 13). RESULTS: Chymase activities in the vitreous from patients with MH, PDR, ERM, and RRD were 1.87 +/- 0.53, 0.06 +/- 0.04, 0.40 +/- 0.12, and 0.08 +/- 0.03 (mean +/- SE) mU/mg protein, respectively, and ACE activities in the vitreous humor were 0.18 +/- 0.09, 0.30 +/- 0.07, 0.01 +/- 0.01, and 0.03 +/- 0.02 (mean +/- SE) mU/mg protein, respectively. Chymase activity was significantly elevated in MH among these diseases (p < 0.01, Scheffe), and ACE was significantly activated in PDR compared to ERM and RRD (p < 0.05, Scheffe). CONCLUSIONS: Our results suggest that two different angiotensin II generating systems are activated in human vitreous humor; an increased activity of chymase may play a possible role in the formation of macular holes.

Aged↗
PubMedDate not supplied

Construction of a differentiated human hepatocyte cell line expressing the herpes simplex virus-thymidine kinase gene.

Transient support using a hybrid artificial liver (HAL) device is a promising treatment for the patients with acute liver failure. Primary human hepatocytes are an ideal source for HAL therapy; however, the number of human livers available for hepatocyte isolation is limited by competition for use in whole organ transplantation. To overcome this problem, we previously established a highly differentiated human fetal hepatocyte cell line OUMS-29. Considering the potential risk when using these genetically engineered cells in humans, additional safeguards should be added to make the cells more clinically useful. In this work, the herpes simplex virus thymidine kinase (HSVtk) gene was retrovirally introduced into OUMS-29 cells. One of the HSVtk-expressed clones, OUMS-29/thymidine kinase (TK), grew in chemically defined serum free medium and expressed the genes of albumin, asialoglycoprotein receptor, glutamine synthetase, glutathione-S-transferase pi, and blood coagulation factor X. In vitro sensitivity of the cells to ganciclovir was evaluated. Intrasplenic transplantation of 50 x 10(6) OUMS-29/TK cells prolonged the survival of 90% hepatectomized rats compared with medium injection alone (control). In the present study, we have established highly differentiated immortalized human hepatocytes with tight regulation. The cells may be clinically useful for HAL treatment.

Albumins↗
PubMedDate not supplied

Expansion of human hepatocyte populations by a retroviral gene transfer of simian virus 40 large T antigen.

A hybrid artificial liver (HAL) could be used to treat acute liver failure or to serve as a temporary support until orthotopic liver transplantation is available. Primary human hepatocytes are ideal as a source of hepatic function in a HAL device. However, the worldwide shortage of human livers available for hepatocyte isolation severely limits this form of therapy. A possible alternative is to use a tightly regulated cell line that can be economically grown in culture to have differentiated liver function. In this work, human hepatocytes were immortalized with a retroviral vector SSR#69 expressing the genes of simian virus 40 large T antigen and herpes simplex virus-thymidine kinase. One of the resulting clones, NKNT-3 , showed the gene expression of differentiated liver function and were sensitive to the antiviral agent ganciclovir. When transplanted into the spleen of rats subjected to 90% hepatectomy, NKNT-3 cells prolonged the survival of 90% hepatectomized rats. The cells provide the advantages of unlimited availability, sterility, uniformity, and freedom from pathogens. This work represents a potential novel strategy for resolving the organ shortage that currently limits the use of primary human hepatocytes to develop a HAL.

Acute Kidney Injury↗
PubMedDate not supplied

The pathogenesis of biliary atresia in Japan: immunohistochemical study of HBV-associated antigen.

An immunohistochemical study of HBV-associated antigen in the liver of 16 Japanese infants with biliary atresia revealed positive findings in 13 of the cases for HBc and/or HBs antigens. The positive cells were mainly small liver cells distributed in the peripheral zone of the lobule, and a few lymphocytes were observed in contact with or around the positive liver cells for HBV-associated antigen. Again, HBc antigen was demonstrated almost exclusively in the cytoplasm of positive liver cells. As these findings suggest the possibility of destruction and drop-out of cells constituting the interlobular bile duct in the junctional area by an immunological mechanism, the probability of HBV infection being an important factor in causing and accelerating biliary atresia cannot be denied. Positive findings for HBV-associated antigen similar to those found in biliary atresia are also seen in neonatal hepatitis and choledochal cysts. These conditions are therefore presumed to belong to the same category.

Biliary Atresia↗
PubMedDate not supplied

Idiopathic saccular aneurysm of the azygos vein.

Idiopathic saccular aneurysm of the azygos vein is a rare condition. We report the case of a 52-year-old man with saccular aneurysm of the azygos vein who underwent surgical resection. Preoperative dynamic computed tomography revealed strong and rapid enhancement of the chest mass. Magnetic resonance imaging showed a thoracic tumor with low signal intensity on the T1-weighted image and coexistence of low and high signal intensity on the T2-weighted image. Intraoperative findings showed cystic dilatation of the azygos vein. Although an accurate preoperative diagnosis of saccular azygos vein aneurysm is difficult, especially differential diagnosis between this anomaly and mediastinal tumors, a markedly enhanced mass shown by dynamic computed tomography was useful for the preoperative diagnosis of this anomaly.

Azygos Vein↗