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Biomedical subjects

K Tsukada

Publications and source records attributed to K Tsukada.

At least 199 records · Page 11Linked to original sources
PubMed1992

Reversible G1 arrest induced by dimethyl sulfoxide in human lymphoid cell lines: kinetics of the arrest and expression of the cell cycle marker proliferating cell nuclear antigen in Raji cells.

In order to elucidate further the mechanism of reversible cell cycle arrest induced by treatment of Raji cells with 1.5% dimethyl sulfoxide (DMSO), we have performed a detailed analysis of the kinetics of arrest and of reentry into the cell cycle after removal of DMSO and have correlated cell cycle progression with expression of proliferating cell nuclear antigen (PCNA). No significant effect of DMSO on cell cycle patterns, assessed by flow cytometric analysis of bromodeoxyuridine-prelabeled cells, was seen for the first 19 h of treatment. A clear reduction of entry into S phase was detected by about 25 h of treatment; essentially all cells were arrested with a G1 content of DNA after 96 h of treatment. When DMSO-arrested cells were released from the block, entry into S phase began at 12 h after release and continued in a fairly asynchronous manner for a further 12-14 h. In arrested cells, the content of PCNA was reduced to about 25% of the amount present in logarithmically growing G1 phase cells. Six h after release from DMSO, PCNA RNA transcripts were first detected by Northern blotting. The increase of PCNA protein, detected by Western blotting, was seen by 9 h after release. The kinetics of entry into the cell cycle and restoration of PCNA protein are similar to that seen in serum stimulation of quiescent cells. These results suggest that DMSO reversibly arrests proliferation of Raji cells at G0 or at an early point in G1 phase and that progression through late G1 phase and entry into S phase are correlated with synthesis of the PCNA gene product.

Antigens, Neoplasm↗
PubMed1992

Early carcinoma of the gallbladder.

OBJECTIVE: To clarify the definition and clinicopathological characteristics of early cancer of the gallbladder. DESIGN: Open study. SETTING: University hospital. SUBJECTS: 78 patients with pathological stage T1a and 11 with pT1b tumours. INTERVENTIONS: Of those with pT1a tumours, 51 were treated by simple, and 27 by radical, cholecystectomy. For those with pT1b tumours the figures were 5 and 11, respectively. RESULTS: There were two recurrences, both in patients with pT1a tumours, histological examination of which had shown tumour present at the surgical margins. There were no cases of neurovascular invasion but only one case of lymphatic invasion that was mild and restricted to the lamina propria in a patient with a pT1b tumour. The outcome in the rest was excellent. CONCLUSION: Most pT1 cancers spread locally. Complete resection results in cure regardless of the scope of the operation done. The main determinant of prognosis is the presence of tumour at the resection margins. All pT1 cancers can therefore be regarded as early cancers of the gallbladder.

Cholecystectomy↗
PubMed1992

[A case of aconitine poisoning accompanied by bidirectional ventricular tachycardia treated with lidocaine].

A rare case of aconitine poisoning accompanied by bidirectional ventricular tachycardia was reported. A 67-year-old male ate several leaves of a wild plant which had been collected in Fukushima Prefecture, Japan. About 90 minutes later, he felt numbness and weakness of the limbs and vomiting took place, and he was admitted to our hospital. The blood pressure was 80/60mmHg, and the electrocardiogram showed multiple premature ventricular contractions and bidirectional ventricular tachycardia. After bolus injection of lidocaine, continuous administration of the drug was started. Immediately after starting the treatment, the arrhythmia disappeared and hemodynamic changes improved. Thereafter the wild plant was ascertained to be a species of Aconitium. Diagnosis of aconitine poisoning was made. According to the fact that aconitine acts as a agonist of Na-channel receptor, antiarrhythmic agents which belong to Vaughan-Williams' classification I might be the first choice for the therapy of aconitine induced arrhythmias.

Aconitine↗
PubMed1992

DNA ligase I mRNA and enzyme levels in human hematopoietic cells under dimethyl sulfoxide-induced growth-arrest and differentiation.

About half the activity level of DNA ligase I in cycling human lymphoblastoid cells (Raji and Akata) remained in the cells arrested at G1 by a 4-day treatment with 1.5% dimethyl sulfoxide (DMSO), and one-third the enzyme activity in actively growing promyelocytic leukemia cells HL-60 was detected in the terminally differentiated cells after DMSO-treatment. In contrast, DNA ligase I mRNA was negligible in the G1-arrested Raji and differentiated HL-60 cells. The steady-state mRNA level was increased 9 h after release from DMSO in the G1-arrested Raji cells and reached a maximum at 18 h. These results indicate that gene expression of human DNA ligase I, but not activity level of the enzyme, is closely correlated with activity of cell proliferation.

Cell Differentiation↗
PubMed1991

Delayed postanoxic encephalopathy after strangulation. Serial neuroradiological and neurochemical studies.

A 13-year-old boy was the victim of attempted strangulation. His condition had returned to normal by the sixth day after the assault; however, from the seventh day, choreoathetosis, dystonia, and marked pseudobulbar paralysis developed in the boy. The computed tomographic scans and T2-weighted magnetic resonance images that were obtained at this time revealed low-density and high-signal intensities in the region of the bilateral putamen and caudate nucleus. These symptoms and the changes in his computed tomographic scans and magnetic resonance images subsided gradually during a 2-month period. Sequential analysis of the cerebrospinal fluid for gamma-aminobutyric acid and dopamine concentrations during his illness revealed reciprocal changes with normal recovery. Because of the delayed onset of neurological changes and the cerebrospinal fluid showing reversible symptoms, the delayed encephalopathy after strangulation had been related to the biochemical alterations that followed anoxia in the vulnerable basal ganglia.

Adolescent↗
PubMed1991

Systemic cytotoxic chemotherapy and radiation therapy for desmoid in familial adenomatous polyposis.

Forty-two of 416 familial adenomatous polyposis (FAP) patients in the FAP registry at the Cleveland Clinic had desmoid tumors. The role of cytotoxic chemotherapy and radiation therapy in the management of these patients was investigated. Eight intra-abdominal desmoid tumors were treated by systemic cytotoxic chemotherapy. Two had complete remission, and one had partial remission. Five patients died as a result of the desmoid tumor or late complications of chemotherapy. Three intra-abdominal desmoids were treated by radiation therapy with no response. Neither cytotoxic chemotherapy nor radiation therapy is recommended as a first-choice treatment for intra-abdominal desmoid tumors in patients with FAP.

Adenomatous Polyposis Coli↗
PubMed1991

Resection and double ileostomy as an alternative approach for superior mesenteric venous thrombosis in poor risk patients: a case report.

An 85-year-old male with a sudden onset of abdominal pain was operated on under the suspicion of intestinal ischemia and was later diagnosed as acute superior mesenteric venous thrombosis (SMVT). The patient was successfully treated by resecting the entire involved bowel and performing a double ileostomy. These procedures are considered to be the preferred method of choice for improving survival in poor risk patients.

Aged↗
PubMed1991

Expression of c-fos and c-myc in Raji Burkitt's lymphoma cells during the progression of DMSO-induced G1 cells into S phase.

Using flow cytometry, we have recently found that dimethyl sulfoxide (DMSO) reversibly induces G1-arrest in the cell cycle of human lymphoid cell lines such as Raji, Akata, and Molt-4. Here we investigated c-fos and c-myc expression in Raji Burkitt's lymphoma cells at DMSO-induced G1 arrest and after release from DMSO. A small but significant accumulation of c-fos mRNA was observed in G1-arrested Raji cells after treatment with 1.5% DMSO for 96 h. When G1-arrested Raji cells were transferred to DMSO-free medium, a transient increase in c-fos transcripts was detected 30-60 min after the release. The steady state level of c-myc transcripts in G1-arrested Raji cells was found to be one-third that in the log-phase cells. After removal of DMSO, the level of c-myc mRNA was restored and reached a maximum at 4.5-6 h. Immunoblot analysis with a monoclonal antibody against human c-myc protein indicated that c-myc protein in the G1-arrested cells was decreased less than one-tenth that in the log-phase cells. The level of c-myc protein gradually increased after the release from DMSO and reached a maximum at 6-9 h.

Blotting, Northern↗
PubMed1991

Upbeat nystagmus: clinicopathological and pathophysiological considerations.

We describe an electro-oculographic study of upbeat nystagmus in 4 patients, with neuropathological correlation in one. All patients had lesions in the pontine tegmentum. The electro-oculographic data may be explained by imbalanced vertical vestibular or smooth pursuit eye movement control. The nystagmus stopped or reversed direction during convergence or in supine head positions. We propose that changes in the intensity or direction of upbeat nystagmus that are induced by convergence or changes in head position, are caused by vertical imbalance in the otolithic-ocular reflex, when superimposed on an imbalanced vestibulo-ocular reflex (VOR). Imbalance of the otolithic-ocular reflex and the vertical VOR are caused by damage in the pontomedullary tegmentum.

Adult↗
PubMed1991

Human T-lymphotropic virus type 1-associated myelopathy and primary sclerosing cholangitis.

We report the first case of human T-lymphotropic type 1-associated myelopathy (HAM) linked with primary sclerosing cholangitis (PSC). The patient, a 44-year-old woman, also suffered from ulcerative colitis and polyarthritis. Two years and nine months after the clinical onset of PSC, the coexistence of HAM was shown by neurological manifestations characterized by slowly progressive symmetrical myelopathy, predominantly involving pyramidal tracts, and positive antibodies to human T-lymphotropic virus type 1 in serum as well as in cerebrospinal fluid.

Adult↗
PubMed1991

Protease inhibitors prevent the development of human rotavirus-induced diarrhea in suckling mice.

Oral inoculation of human rotavirus MO strain (serotype 3) into 5-day-old BALB/c mice caused gastroenteritis characterized by diarrhea (90% on the average, on day 2). Using this animal model, preventive effect of antiviral agents on the development of rotavirus-induced diarrhea was examined. The infectivity of human rotavirus was enhanced by treatment with protease in vitro. A cysteine protease inhibitor, E-64-c, was given orally at 12 hr and 24 hr after MO infection. Oral administration of 0.3 mg of E-64-c decreased the diarrhea ratio to 17.5% on day 2 and to 10% on day 3. Oral administration of 0.15 mg of cysteine protease inhibitor, ovocystatin, completely prevented the diarrhea on day 2. Serine protease inhibitor, aprotinin (0.15 mg x 2), also prevented the diarrhea on day 2 to 14.3%. These protease inhibitors were nontoxic in vitro and to suckling mice. The histopathological changes in the small intestine due to infection recovered 2 days after MO infection in mice treated with E-64-c and ovocystatin. These results suggest that protease inhibitors are protective agents for human rotavirus infection by inhibiting proteases required for viral replication.

Administration, Oral↗
PubMed1991

Primary position upbeat nystagmus. Clinicopathologic study of four patients.

We report an electro-oculographic study (EOG) of upbeat nystagmus and neuroradiological correlations in 4 patients and neuropathological findings in 1 patient. All 4 patients revealed responsible lesions in the lower pontine tegmentum. The EOG data suggest that our patients had a deficit in vertical smooth eye movement balance. The nystagmus stopped or reversed direction during convergence or changes of head position. These EOG findings might be caused by vertical imbalance in the otolithic ocular reflex, superimposed on an imbalanced vestibulo-ocular reflex (VOR), secondary to a damage to the pontomedullary tegmentum.

Adult↗
PubMed1991

Clinical studies on hemorrhagic fever with renal syndrome found in Nagoya City University Medical School.

This study refers to the clinical features of 11 cases of hemorrhagic fever with renal syndrome (HFRS) which was prevalent in Nagoya City University Medical School. The clinical course was divided into two parts: the febrile stage and the polyuria stage. Symptoms such as lumbago, muscular pain, general malaise and anorexia disappeared along with a fall of fever. The incubation period of this disease was estimated to be about three weeks. Polyuria, proteinuria, gastric complication and impairment of liver function seemed to be some of clinical features of this disease. There was no HFRS patient with severe renal failure in our cases. The presence of disseminated intravascular coagulation (DIC) was confirmed in 3 of these 11 cases. Therefore, it was suggested that hemorrhagic tendency of this disease might be attributed to DIC. From our experiences, the most important factor for the treatment of the severe case was the earliest detection whether they were complicated by DIC or not. If they were suspected of DIC, it could be necessary to start treatment for DIC as soon as possible. Prophylactic measures for HFRS in our animal facility could contribute to the prevention of this disease.

Blood Cell Count↗