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S Tsuchimoto

Publications and source records attributed to S Tsuchimoto.

At least 37 records · Page 2Linked to original sources
PubMed1988

Two genes, pemK and pemI, responsible for stable maintenance of resistance plasmid R100.

Plasmid R100 was found to have two genes, designated pemK and pemI, that were responsible for its stable inheritance during cell division. They are located near the region that is essential for autonomous replication. Under conditions that inhibit replication of R100 derivatives, the plasmid containing these pem genes gave only a few segregants in viable cells and increased the number of nonviable cells in the population, suggesting that a product from the pem region stabilized the plasmid by killing plasmid-free segregants. Inactivation of one of the two translational open reading frames in the pem region caused the loss of the killing function, and thus, the open reading frame is a gene designated pemK, which encodes the killing factor. The coexistence of the pem+ plasmid with a high-copy-number plasmid carrying the other open reading frame inhibited stabilization, and thus, the second open reading frame is a gene designated pemI, which encodes the inhibitor which might control the killing function of pemK. It is likely that the two open reading frames were transcribed from a promoter. There were no significant homologies in DNA sequences between the pem gene of R100 and the genes previously shown to be responsible for the stable inheritance of the other plasmids.

Amino Acid Sequence↗
PubMed1988

A case of large intestinal malignant lymphoma.

Primary malignant lymphoma of gastrointestinal tract is relatively rare and the most of it are seen in stomach or small intestine, and in Japan only 130 cases of primary large intestinal malignant lymphoma were reported from the accumulating results of the postoperative cases in the 11th Congress of the Japanese Research Society for Cancer of the Colon and Rectum. This paper describes the case report of the primary malignant lymphoma originated from the cecum, and the review of the literature. The patient was 63 year-old female, who came to this hospital for slight fever and right lower abdominal pain that was gradually increasing. After the investigation by using barium enema and the intrapelvic CT, cecum tumor was detected. The ileocecal excision was performed, and revealed the 4 X 4.5 cm tumorous type lesion of which surface was slightly irregular. Histopathologically the tumor was follicular lymphoma (partial type), medium sized cell type by the Lymphoma-leukemia Study Group (LSG) classification. After discharge, cyclophosphamide was administered by 100 mg/day for six weeks, and the sign of the recurrence has not been observed.

Cecal Neoplasms↗
PubMed1987

Hepatic transplantation into sensitized recipients. Demonstration of hyperacute rejection.

Hepatic transplantation into humorally presensitized patients has occasionally been performed without reported accelerated rejection. To study survival of orthotopic hepatic transplants in sensitized recipients a series of studies in rats were performed. Lewis rats sensitized by three successive skin grafts from fully allogeneic ACI strain donors then underwent orthotopic hepatic transplantation from ACI donors. Nine of ten recipients died within 4 hr with bleeding from the liver surface. By comparison, nine unsensitized recipients survived a mean of 10.7 +/- 0.5 days before succumbing with cellular rejection. Death of the sensitized recipients was not due to coagulopathy or technical failure. Histological studies of hyperacutely rejected livers demonstrated marked hemorrhage, edema, congestion, and necrosis within the hepatic parenchyma. There was a relative lack of cellular infiltrate compared with livers rejected by unsensitized recipients. Immunofluorescent staining showed IgG bound to perivascular tissues and sinusoids, and complement bound to perivascular tissue. Serum from presensitized, but not control, recipients showed a high titer of donor-specific, complement-dependent cytotoxic activity. It is concluded that hyperacute rejection of hepatic transplants can occur in sensitized rats and is mediated by a humoral mechanism. The immunohistopathology of this process is described.

Animals↗
PubMed1987

Leukocyte subsets infiltrating into fully allogeneic, long-surviving rat liver allografts.

Leukocyte subsets that infiltrated into unmodified LEJ(RT1j)2 liver grafts from WKAH(RT1k) hosts were studied. This strain combination is fully allogeneic and yields acute rejections in skin and kidney transplantations. On days 3, 7, and 14, cellular infiltrates gradually increased, and many hepatocytes were degenerative and lost cellular glycogen. Blastoid lymphocytes were frequently seen, and mitotic features of hepatocytes were prominent (on day 14, 3 to 4/10 high-power fields). Later, on days 30, 50, and 300, the cellular infiltrates gradually subsided, and blastoid lymphocytes were rarely seen. Throughout the course, Ia+ cells (RT1.Dk+ and/or RT1.B+ cells) were the major cell populations infiltrating into the grafts. Most of the host RT1.D+ cells were histiocytoid in appearance on immunoelectron microscopy. Histiocytoid cells were the most numerous infiltrating cells, constituting 30-50% of the total infiltrating cells. There were different distributions of T cell subsets between the portal and sinusoidal areas, as we previously observed in acutely rejected rat renal allografts. Both RLyt-1+,2-(Th) and RLyt-1+,2+(Tc/s) cells were found almost equally in the portal area, while RLyt-1+,2+(Tc/s) cells predominated over RLyt-1+,2-(Th) cells in the sinusoidal area. However, a gradual replacement of RLyt-1+,2-(Th) cells by RLyt-1+,2+(Tc/s) cells, as seen in the perivascular area of renal grafts, was not found in the portal areas of the liver grafts. Except for the latter finding, the pattern of cellular infiltrates was similar to that of acute renal rejection, and the significance of these cellular infiltrates is discussed.

Animals↗
PubMed1986

[Orthotopic liver transplantation in the rat].

In the present study, rat orthotopic liver grafting was performed in order to investigate genetical, immunological and pathological aspects of liver transplantation. In the rat, MHC (RT1) incompatible liver grafts are mostly rejected in an acute fashion like other organs, and Class II antigen-barrier had a stronger effects on the survival of liver grafts than that of class I antigens. But in Some combinations, full RT1 incompatible grafts can survive indefinitely. The mechanisms of long survival of liver grafts are complicated dynamically but regulated systematically. While the hepatocytes are regenerating from the damage by the attack of the host immune reactions, the condition of host immune response is gradually changed from positive to negative. Immunosuppressive humoral factors (anti-Ia antibodies, anti-idiotypic antibodies, class I-like antigens secreted from hepatocytes, etc.) are produced and later suppressor cells are induced. Both of them can suppress the immune reactions (MLR, CTL induction etc.) successfully. These results indicate that liver grafts stand strong having potential regenerating activity and changing the host anti-graft immunity to immunologically unresponsive state.

Animals↗
PubMed1984

[The role of brain-stem vasomotor centers on the neurogenic control of the neurogenic control of cerebrovascular tonus. Part 1: In special reference to cerebral blood volume and intracranial pressure].

An increase in cerebral blood volume (CBV) due to a decrease in cerebrovascular tonus has been though to be a major factor in the cause of acute brain swelling. It has been reported that the dorsomedial nucleus of the hypothalamus (DM), one of the brain-stem vasomotor centers, regulates cerebrovascular tonus. The DM and other vasomotor centers, such as the midbrain reticular formation (MBRF) and the reticular formation of the medulla oblongata (MORF), are connected through a series of nerve fibers. This experiment was designed to clarify the neurogenic control of the DM, MBRF, and MORF on cerebrovascular tonus. Using fifty-six cats, unilateral and bilateral DM(A 1.2, L2.0, H-10.0), MBRF (A4.0, L4.0, H0), and MORF (P10.0, L2.5, H-9.0) were coagulated stereotaxically with the condition of 15-10 mA for 1 minute. The lesions in the DM and MBRF were enlarged by increasing the current intensity of electrical coagulation. The effects of the increase on a number of simultaneously coagulated lesions were examined. Changes in systemic blood pressure (BP), intracranial pressure (ICP), and CBV were continuously recorded. Temporary increases in ICP (mean increase 16 mmHg, n = 14) and CBV were observed after unilateral coagulation of the DM. These increases were associated with transient systemic hypotension. The changes lasted only for approximately 5 minutes. The changes that occurred in ICP and CBV as a result of unilateral coagulation in the MBRF were almost the same as those that occurred after coagulation of the DM. In the latter case, the duration of the change was approximately 6 minutes with a mean increase of 12 mmHg (n=12).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1983

Anterior inferior cerebellar artery aneurysm. Report of three cases.

Three cases of aneurysms of the anterior inferior cerebellar artery are reported. Two of the aneurysms were located in the cerebellopontine angle and one in the ventral portion of the pons. Through a suboccipital craniectomy, beck clipping was performed on one aneurysm, neck ligation on another, and coating on the third. A discussion of the surgical procedures and complications includes a review of previous reports.

Adult↗