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Biomedical subjects

K Takeuchi

Publications and source records attributed to K Takeuchi.

At least 1,207 records · Page 67Linked to original sources
PubMed1985

Aneurysms associated with moyamoya disease.

Seven cases of moyamoya disease accompanied by an aneurysm were studied. The patients, two males and five females, were 13 to 57 years old (average, 32). The cases were classified into two groups: Group A (five cases), in which the aneurysm was located within the moyamoya vessels, and Group B (two cases), in which the aneurysm was located within the circle of Willis and remote from the moyamoya vessels. In all Group A cases, the presenting episode was intracerebral and intraventricular hemorrhage due to rupture of the aneurysm. One patient suffered two separate attacks. In this case, the aneurysm disappeared spontaneously. In one of the two Group B cases, there was hemorrhage from an anterior communicating artery aneurysm. In the other case, with a basilar-superior cerebellar artery aneurysm, there was hemorrhage from the moyamoya vessels.

Adolescent↗
PubMed1985

[Cerebrospinal fluid absorption mechanism--based on measurement of CSF flow rate in shunt tube].

The cerebrospinal fluid (CSF) absorption mechanism in cases of hydrocephalus was investigated on the basis of measurements of CSF flow in a shunt tube after ventriculo-peritoneal shunt surgery, monitoring of intracranial pressure, CT findings, radioisotope cisternography, cerebral blood flow, EEG, PSP tests and changes in neurological findings. The subjects were 6 males and 7 females aged from 18 to 70. CSF flow rates in the shunt tubes were between 0.01 and 1.93 ml/min. Calculating the daily volume of CSF flow, the subjects were divided into two groups: Group A (8 patients) with a volume of less than 150 ml/day (0.01-0.25 ml/min), and Group B (5 patients) with between 150 and 500 ml/day (0.01-1.93 ml/min). Monitoring of intracranial pressure prior to the shunt operation was performed in 10 cases. These pressure values ranged between 4 and 25 mmHg (mean: 7-8 mmHg), and there was no difference between the two groups. The pre-and post-operative radioisotope cisternography findings indicated improvement of ventricular dilatation, periventricular lucency and ventricular reflux. After the shunt operations, there was neurological improvement in 6 of the 8 Group A cases but only in 2 of the 5 Group B cases. Considering the CSF flow volumes of the two groups, it appears that in Group A the shunt tube is not the main CSF circulation pathway. This could mean that resistance to CSF absorption in the cerebrospinal space has decreased after the shunt operation and there has been recovery of the physiological CSF absorption pathways. In other words, neurological improvement can be expected in this group A.

Adolescent↗
PubMed1984

Characterization of African green monkey B-cell lines releasing an adult T-cell leukemia-virus-related agent.

Eight lymphoblastoid cell lines were established from the peripheral blood of individual African green monkeys (AGM). The AGM-2206 line grew out spontaneously. The others - AGM-6, 7, 8, 10, 12, 13, and 16 - were obtained after infection of peripheral AGM lymphocytes with cell-free culture supernatant of AGM-2206. All lines contained, and were probably transformed by, AGM-EBV. Moreover, they expressed immunoglobulins but lacked the Leu l T-cell marker. Thus they were B cells. Since a high percentage of AGMs are naturally infected with a virus similar to adult T-cell leukemia virus (ATLV), we examined these cell lines for ATLV. With immunofluorescence tests we detected ATLV-related antigens (ATLA) in three of the eight cell lines. EBV membrane antigen was present in three out of four. The highest percentage (40%) of ATLA-positive cells was found in the AGM-13 line. After metabolic labelling of these cells, ATLV-specific polypeptides p24, p19, p15, and p10 were detected. Hybridization experiments showed that both AGM-2206 and AGM-13 cell lines contained ATLV-proviral DNA. Electron micrographs of AGM-13 revealed a few type-C particles morphologically similar to the MT-2 virus. By cocultivation this AGM virus was able to infect and immortalize human peripheral blood lymphocytes. One such human cell line, NA-13, expressed polypeptides closely related to ATLV core antigens but a 68,000 mol.wt. glycopolypeptide was serologically distinct from MT-2 ATLV gp68.

Animals↗
PubMed1984

Factors related to gastric hypersecretion during pregnancy and lactation in rats.

We attempted to elucidate the factors involved in gastric hypersecretion of rats during pregnancy and lactation. Acid secretion in pylorus-ligated and vagally denervated fistula rats stimulated with histamine, tetragastrin, and methacholine increased from midterm pregnancy and persisted during lactation. Pepsin secretion remained unaltered during pregnancy but increased during lactation. Vagal denervation itself abolished this hypersecretion. In late pregnancy, a delayed appearance of maximal acid response to histamine was apparent, as compared to nonpregnant rats, and was abolished by aminoguanidine treatment. There was a delay in the maximal response to tetragastrin but not to methacholine. Serum histamine concentrations were 3-4 times higher in late pregnancy, as compared to nonpregnant, lactating and nonlactating rats. Gastric DNA and protein concentrations were significantly increased in lactating rats with concomitant elevation of food intake and serum gastrin levels. Those changes disappeared in nonlactating rats, and gastric secretion was much the same in the nonpregnant rats. These results indicate that acid hypersecretion during pregnancy was exclusively associated with vagal innervation plus high serum histamine levels, while acid and pepsin hypersecretion in lactating rats were associated with vagal innervation plus hyperplastic gastric mucosa and high serum gastrin levels.

Animals↗
PubMed1984

Possible role of endogenous prostaglandins in alkaline response in rat gastric mucosa damaged by hypertonic NaCl.

Changes in gastric potential difference (PD) and luminal pH of gastric perfusate were studied in anesthetized rats before and after application of hypertonic NaCl to the stomach for 10 min. There was a concentration-dependent reduction of PD and an increase in luminal pH after exposure to NaCl. In the stomach exposed to NaCl over 0.75 M, a significant amount of HCO3- (0.5-1.5 mumol/10 min) was titrated in the lumen at pH 7.4 under cimetidine infusion (8 mg/kg/hr). After removal of hypertonic NaCl, the PD returned completely or partially to the basal values within 1 hr. Pretreatment of the rats with subcutaneously administered indomethacin (3 mg/kg) or aspirin (100 mg/kg) significantly inhibited the recovery of PD in the 1 M NaCl-treated stomach. Gastric alkaline response in the damaged mucosa was significantly attenuated in rats pretreated with indomethacin or aspirin. Intravenously administered cimetidine (8 mg/kg/hr) or subcutaneously administered 16,16-dimethyl prostaglandin E2 (3 micrograms/kg) abolished the inhibitory effect of indomethacin on gastric alkaline response caused by 1 M NaCl, and partially restored the PD recovery. These results indicate that endogenous prostaglandins released in the injured mucosa are probably responsible for the luminal alkalinization noted after exposure to 1 M NaCl. This process would lead to a protection against further damage and accelerate reestablishment of the mucosal integrity.

Animals↗
PubMed1984

Effects of FPL-52694, a new mast cell stabilizer, on gastric secretion and various acute gastric lesions in rats.

Oral FPL-52694 [5-(2-hydroxypropoxy)-8-propyl-4-oxo-4H-1-benzopyran-2-carboxylic acid Na], a new mast cell stabilizer, dose-dependently inhibited gastric acid secretion but increased the volume and pepsin output in pylorus-ligated rats. Intraduodenal FPL-52694 significantly inhibited all of the volume, acidity, acid output and pepsin output. Concerning the acidity, oral administration of the agent showed much more potent inhibition than intraduodenal administration. Oral FPL-52694 markedly inhibited the development of pylorus-ligated ulcers, water-immersion stress- and aspirin-induced gastric erosions and moderately inhibited the formation of reserpine-induced gastric erosions in rats. Intraduodenal FPL-52694 also inhibited pylorus-ligated ulcers whereas it had no effect on aspirin-induced gastric erosions. Histamine-induced gastric erosions were not affected by oral FPL-52694. These effects of FPL-52694 were almost the same as those of cimetidine, except that cimetidine tended to inhibit histamine-induced gastric erosions. Although the precise mechanism of action of FPL-52694 remains unknown, oral FPL-52694 appears to be a promising agent for the treatment of peptic ulcers.

Animals↗
PubMed1984

In vitro infection of human B lymphocytes with adult T-cell leukemia virus.

Experimental transmission of adult T-cell leukemia (ATL) virus (ATLV) into human B lymphocytes was attempted. Cocultivation of B-cell rich fraction of peripheral blood from a healthy adult with X-ray irradiated ATLV producer MT-2 cells resulted in the establishment of OKA(B) cell line co-infected with both Epstein-Barr virus (EBV) and ATLV. OKA(B) cells and its subclones contained: (1) B cell markers exclusively; (2) both EBV-specific antigen, EBNA and ATLV-specific antigen, ATLA detected by immunofluorescence test; (3) ATLV-specific polypeptides, p24 and p19; (4) ATLV-specific mRNA in ATLA-positive clones; (5) ATLV and EBV particles detectable by electron microscopy. These data clearly show that human B lymphocytes are susceptible to ATLV infection.

Antigens, Viral↗
PubMed1984

Contact points between transcription machinery and the fibroin gene promoter deduced by functional tests of single-base substitution mutants.

An efficient method for oligonucleotide-directed mutagenesis was developed to construct a set of site-specific mutations by using a mixture of oligodeoxyribonucleotides. With this method, as high as 40% of the tested clones turned out to be desired mutants. Seven single-point mutants were isolated in the "TATA" box region of the fibroin gene. In vitro transcription experiments showed that single-base transversions at the TATA box (A----T at position -29, T----A or G at -28, A----T at -27, and A----T at -26) resulted in decreased promoter activities, whereas A----G transitions at positions -24 and -23 had no effect. The initiation site of transcription was normal in three down-promoter mutants at positions -28 and -26, but the A----T transversions at positions -29 and -27 induced an additional transcription start from position +4. Using 10 single-point mutants obtained as above or by nitrous acid-induced mutagenesis, we have prepared a pair of heteroduplex DNAs consisting of a mutant strand and the wild-type one. The molecules heterozygous at positions -30, -21, and -20 showed reduced transcription activities when the noncoding strand bears the mutation, whereas that at position -26 gave a low activity when the coding strand carries the mutation. Both types of heteroduplex at positions -29, -28, -27, and -17 exhibited decreased activities. These results suggest a transcription machinery contact to a major groove of the DNA helix at the TATA box and region of position -20.

Animals↗
PubMed1984

Characterization of human B-cell lines harbouring both adult T-cell leukaemia (ATL) virus and Epstein-Barr virus derived from ATL patients.

Human B-cell lines, designated ATLB cell lines, were spontaneously established from peripheral blood of adult T-cell leukaemia (ATL) patients. The cell lines consistently expressed ATL-associated antigen (ATLA) and Epstein-Barr virus-associated nuclear antigen (EBNA). A cloned ATLB line, designated ATLB 2, showed that both ATLA and EBNA antigens were present in the same B-cell clone. In this study, we have further characterized ATLV and EBV in the cloned ATLB 2 cell line by biochemical techniques. The ATLA antigens in these clones, initially shown by immunofluorescence, were studied by immunoprecipitation with human sera from ATL patients and the Western blotting technique using a mouse monoclonal antibody (GIN-14). We identified ATLV core polypeptides 24K and 19K in the ATLB cell extracts. Furthermore, total cellular DNA and poly(A) RNA from the ATLB cell lines were analysed for the presence of viral genomes with molecularly cloned DNA probes containing the ATLV and EBV sequence, respectively. The results showed that all ATLB 2 clones contained highly conserved ATLV proviral DNA irrespective of whether or not they expressed ATLA. They also contained several copies of EB virus DNA and DNA-DNA reassociation kinetics studies clearly showed that most of the EBV DNA sequences were present in ATLB cells. ATLV-related mRNA was detected in only ATLA-positive clones (ATLB 2-3 and 2-21) but not in a negative clone (ATLB 2-45).

B-Lymphocytes↗
PubMed1984

Abnormal phosphatidylinositol-cycle of platelet membrane in schizophrenia--a preliminary study.

Phosphatidylinositol (PI)-cycle in the platelet membrane was examined in eight untreated patients with psychotic symptoms. A defect of PI-cycle in the transformation from 1,2-diacylglycerol into phosphatidic acid was found in three patients, who were diagnosed as having Schizophrenic Disorders or Schizophreniform Disorder according to the DSM-III criteria. Two out of the three patients were reexamined while undergoing neuroleptic medication, and they showed the same abnormality in PI-cycle. Further studies were required to determine the nature of the abnormality in PI-cycle in the platelets of schizophrenics.

Adolescent↗
PubMed1984

Screening of sugars inhibitory against sucrose-dependent synthesis and adherence of insoluble glucan and acid production by Streptococcus mutans.

Various sucrose derivatives and a sucrose analogue were enzymatically synthesized on the assumption that structural similarities of the sugars to sucrose would endow them with an ability to inhibit the cariogenicity of sucrose. The effect of these sugars on sucrose-dependent synthesis and adherence of insoluble glucan and on acid fermentation of sucrose by Streptococcus mutans was examined in vitro. Although none of them inhibited the acid fermentation, several sugars not only inhibited the synthesis and adherence of insoluble glucan, but were themselves only slightly fermented as well.

Acids↗
PubMed1984

A case of tuberculous epididymitis associated with Addison's disease.

A 68-year-old man was admitted to the hospital because of loss of appetite, easy fatigability, and skin pigmentation. Physical examination revealed that the bilateral epididymides were enlarged and hard without tenderness. At 7 a.m., the basal cortisol level in the plasma was 22.4 ng/ml and ACTH 318 pg/ml. The clinical diagnosis was Addison's disease. Biopsy of the right epididymis revealed evidence of active tuberculosis. Hydrocortisone (18 mg/day) and anti-tuberculous drugs were administered, and the patient became well and regained his appetite in a week. In this case, laparotomy was not performed, but all clinical findings and the course indicated that adrenal tuberculosis was the most likely cause of Addison's disease. CT scanning of the adrenal region demonstrated large, bilateral, homogeneous, low density, and non-enhancing mass. This is the first report dealing with CT findings of Addison's disease with tuberculous epididymitis.

Addison Disease↗