Search PubMed⌕ Search

Biomedical subjects

S Sakuma

Publications and source records attributed to S Sakuma.

At least 289 records · Page 16Linked to original sources
PubMed1988

Persistent infection with herpes simplex virus type 1 in an Ia antigen-positive murine macrophage cell line.

The interaction of herpes simplex virus type 1 (HSV-1) with murine macrophage cell lines was examined. The cell lines appeared to be moderately permissive for HSV-1 replication, though the yield of the virus was limited compared with that in Vero cells. Furthermore, the murine macrophage cell line SL-1, bearing Ia antigen, was persistently infected with HSV-1 for over one year, and was designated SL-1/KOS. Persistent infection could not be established in an Ia antigen-negative macrophage cell line, SL-4. In the SL-1/KOS culture, there was a small number of infected cells as revealed by infectious center assay. Treatment with monoclonal antibody against HSV-1 cured the persistent infection. Therefore maintenance of the persistent infection is considered to be due to a carrier culture consisting of a minority of infected cells and a majority of uninfected cells. In the SL-1/KOS cultures a low level of interferon (IFN) was found. When a large amount of exogenous recombinant murine IFN-beta (10(5)-10(6) international units/ml) was added to the culture, virus production diminished to undetectable levels. These results suggest that IFN plays an important role in the maintenance of persistent infection. In long-term persistently infected cultures, syncytium formation appeared and the virus from such cultures had a different DNA structure from that of the virus originally used for infection as revealed by restriction endonuclease analysis.

Animals↗
PubMed1988

Effect of tiopronin on prostaglandin synthesis in rabbit kidney medulla slices.

The effect of 2-mercaptopropionylglycine (tiopronin), which is widely used for the treatment of various hepatic disorders, on the generation of medullary prostaglandins (PG) E2 and F2 alpha has been examined. Tiopronin had a potent inhibitory effect on PG E2 formation. Simultaneously, PG F2 alpha production was increased. In the presence of tiopronin the net increased amount of PG F2 alpha was much smaller than the net decreased amount of PG E2 (6-20%). These results suggest that tiopronin has the potential to modulate PG E2 and F2 alpha synthesis by affecting endoperoxide E2 isomerase or endoperoxide reductase and that this effect may represent some pharmacological action of the drug.

Animals↗
PubMed1988

One-shot dual-energy subtraction chest imaging with computed radiography: clinical evaluation of film images.

A clinical evaluation of one-shot dual-energy subtraction chest imaging by means of computed radiography (CR) with imaging plates was carried out in a comparison with the original plain CR images. In analyses of chest images of 140 patients, new information, not detected on the original plain CR images, was obtained on subtraction images in 21 patients (15%). Receiver operating characteristic curve studies also verified the superiority of CR subtraction over the original plain CR images for the detection of pulmonary nodules, calcification in a nodule, and rib lesions. Subtraction images complemented the original plain images.

Bone Diseases↗
PubMed1988

Computer-assisted rotation and multiple stationary irradiation technique. Newly designed overrunning multi-leaf collimators for conformation radiotherapy.

A computer-assisted rotation and stationary conformation radiotherapy system with overrunning multileaf collimators has been developed. This system can produce any shape of target volume, including a number of target areas outside the axis of the rotation, regardless of the location of the axis at 360 degrees rotation irradiation. In addition, by changing the dose rate and deleting a partial region within a field, multiple stationary irradiation can produce more homogeneous target volumes--thus avoiding excessive irradiation to critical organs--than the rotation technique.

Humans↗
PubMed1987

Purification of saikosaponins a, c and d. Application of large-scale reversed high-performance liquid chromatography.

The preparative separation of saikosaponins a, c, and d from Bupleurum falcatum was performed by high-performance liquid chromatography on a 100 X 11 cm I.D. axially compressed column, packed with 20-micron ODS silica gel using a step gradient with mixtures of acetonitrile and water as the mobile phase. Gram quantities of pure compounds were obtained in a single run.

Chromatography, High Pressure Liquid↗
PubMed1987

Cyclosporin A inhibits late steps of T lymphocyte activation after transmembrane signaling.

The in vitro stimulation of murine splenic T lymphocytes with concanavalin A (Con A) produced interleukin 2 (IL2). The addition of cyclosporin A (CsA) to the culture resulted in complete inhibition of IL2 production. The Con A stimulation of T lymphocytes induced the breakdown of phosphatidylinositol into inositol trisphosphate and diacylglycerol, each of which could function as the second messengers in the subsequent signal transduction pathway. CsA did not inhibit the production of inositol (poly)phosphates. Further, CsA did not affect Ca2+-calmodulin functions; a) the redistribution of various cytoskeletal proteins as well as Con A-receptor aggregation, and b) the cytosolic Ca2+-calmodulin-dependent enzyme activities. Moreover, the activity of protein kinase C, which has been accepted to be the target of diacylglycerol, was not influenced in the presence of CsA. While the above steps of signal transduction are bypassed by synergy between calcium ionophore and phorbol ester, T lymphocyte activation which was induced by such stimuli was completely inhibited by CsA. These results indicate that CsA does not influence early steps of T lymphocyte activation as bypassed by calcium ionophore and phorbol ester, but rather inhibits later step(s) subsequent to the activation of protein kinase C and Ca2+-calmodulin.

3',5'-Cyclic-AMP Phosphodiesterases↗
PubMed1987

Increase in intradermal vascular permeability caused by pertussis toxin from Bordetella pertussis.

Rabbits that were injected intradermally with pertussis toxin (PT), produced from Bordetella pertussis, showed slight edema and erythema at the injection sites, but not hemorrhage nor necrosis. The edema lesions were stained blue by the intravenous injection of Pontamine Sky Blue 6B dye, suggesting that PT caused increased vascular permeability, similarly to the permeability factor (PF) of cholera toxin. The reaction of the PF of PT could be determined by measuring the diameter of the blue area. The diameter of the blue area bore a good linear relationship to the logarithm of the dose of PT. The activity of the PF was neutralized by anti-PT rabbit serum. Detoxification of PT with formalin did not increase the vascular permeability, but reverted pertussis toxoid showed a PF reaction in proportion to the reverted leukocytosis-promoting and histamine-sensitizing activities of PT. The supernate of a Bordetella pertussis culture also induced a PF reaction and the reaction could be made clear by heating the supernate at 56 C for 30 min, but the supernate of Bordetella bronchiseptica did not induce the reaction at all.

Animals↗
PubMed1987

Intratumoral blood flow: evaluation with color Doppler echography.

Blood flow in several types of tumors (two hepatomas, two hemangiomas, two renal cell carcinomas, one hydatidiform mole, and five invasive moles) was assessed with real-time two-dimensional color Doppler echography (ultrasound). In one of the hepatomas and all five of the invasive moles (but not in the hydatidiform mole or in either of the hemangiomas), the intratumoral flow was demonstrated with color Doppler echography, correlating well with the angiographic or dynamic computed tomographic findings. In the invasive moles, rapid blood flow was seen within the hypoechoic zone of the tumor. On follow-up study of four of the invasive moles, disappearance of the hypoechoic area due to blood flow was observed when chemotherapy was successful. Trophoblastic disease is considered to be the best application for color Doppler echography because it provides accurate evaluation of residual tumor after chemotherapy.

Carcinoma, Hepatocellular↗
PubMed1987

CT evaluation of pancreatic cancer. Analysis of resected tumours.

Preoperative CT examination including dynamic scan was performed in 25 patients with pancreatic carcinoma. Dynamic scans, which clearly demonstrated the attenuation difference between the normal and neoplastic pancreatic tissue in 92% of cases, were superior to high dose contrast enhancement scans that failed to display the relatively hypodense component of tumours in 40%. Detailed comparison of CT interpretation and surgical or pathological findings revealed the usefulness of CT examination in the evaluation of tumour size and local invasion. However, low sensitivity in detection of metastatic lesions (range: 20-38%) indicates limitations of CT diagnosis.

Adenoma, Islet Cell↗
PubMed1987

[Evaluation of ultrasonography in management of choriocarcinoma and invasive mole].

To clarify the clinical significance of ultrasonography (USG) in the therapeutic course of invasive mole and choriocarcinoma, a detailed study of USG images from 31 patients, taken upon admission, in which an abnormal condition was clearly indicated, was undertaken. In addition, the clinical value of the pulse doppler and color doppler images used to determine the blood flow was also studied. The results revealed the following points. 1) Before the 1st therapy, USG conditions could be classified into three categories, type I (massive echogenic), type II (one or more echo free space (EFS) surrounded with a massive echogenic area) and type III (EFS). 2) A large number of patients with invasive mole exhibited type II, with a few exhibiting type III. A large number of patients with choriocarcinoma exhibited type I, and a few exhibited type II. 3) A comparison with PAG conditions showed a high correlation between the pooling image in PAG and the EFS in USG. 4) There was a positive correlation between the estimated volume of the tumor at the start of therapy and the hCG value in urine. In the chemotherapy patients, the reduction of hCG was accompanied by shrinkage of the tumor, and in 9 out of 22 patients (40.9%), the tumor disappeared on the USG at the point where the hCG became negative. 5) 14 of 22 chemotherapy patients (63.6%) matched the "Standard Progress" course, which was decided and based on the changes observed in the USG image over the course of chemotherapy.(ABSTRACT TRUNCATED AT 250 WORDS)

Choriocarcinoma↗