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Biomedical subjects

K Takeuchi

Publications and source records attributed to K Takeuchi.

At least 1,099 records · Page 61Linked to original sources
PubMed1987

Factors affecting cerebrospinal fluid flow in a shunt.

Nineteen hydrocephalic patients were studied to determine factors affecting cerebrospinal fluid (CSF) flow through shunts. This study was based on our previously reported method by which fluctuations in CSF flow through a shunt of from 0.01 ml min-1 to 1.93 ml min-1 were identified, each having its own rhythmic pattern. While CSF flow in a supine position was less than 0.01 ml min-1, head elevation to 60 degrees led to increases in CSF flow from 0.12 ml min-1 to 0.17 ml min-1. Sudden respiratory changes such as coughing also affected CSF flow. CSF flows were higher than average between 10 pm and 7 am, and changes in CSF flow were related to slight increases in ICP during REM sleep. There is no relationship between CSF flow in a shunt and daily fluid intake which varied from 27 ml kg-1 to 103 ml kg-1, and no significant changes in CSF flow resulting from rapid intravenous injection of Glycerol and Ringer's solution.

Cerebrospinal Fluid↗
PubMed1987

No evidence on significant roles of the prostaglandin-thromboxane and kallikrein-kinin system in the antihypertensive effect of MK 421 in rats made hypertensive by norepinephrine or vasopressin.

Inhibition of angiotensin converting enzyme by MK 421 (6 mg/kg/day ip) induced a significant increase in urinary kinin excretion in norepinephrine-infused rats (1.8 mg/kg/day ip), whereas it had no effect on urinary prostaglandin E2 excretion. In contrast, MK 421 did not induced any significant changes in urinary kinin and prostaglandin E2 excretion in vasopressin-infused rats (7.2 U/kg/day ip). The simultaneous administration of indomethacin (10 mg/kg/day sc), OKY 046 (12 mg/kg/day sc) or aprotinin (100,000 units/kg/day sc) did not affect the antihypertensive effect of MK 421 in rats made hypertensive by chronic infusion of norepinephrine or vasopressin. The present results suggest that the hypotensive effect of MK 421 may depend on a reduced sensitivity of the vasculature to vasoconstrictor substances. In addition, it is also suggested that neither the prostaglandin-thromboxane or kallikrein-kinin systems are essential for the antihypertensive effect of MK 421 in these models of hypertension.

Animals↗
PubMed1987

Effects of angiotensin converting enzyme inhibitors MK 421, SA 446 and captopril on renal prostaglandin E and kinins in conscious normotensive rats.

Angiotensin converting enzyme inhibition by MK 421, SA 446 or captopril (6 mg/kg/day ip) for up to 6 days induced significant fall in systolic blood pressure and plasma angiotensin II concentration. The hypotensive effect was greater in sodium depleted rats than in sodium repleted rats. The hypotensive effect was also accompanied by increased excretion of urinary prostaglandin E2, however the levels of urinary prostaglandin E2 in sodium repleted rats were not different from those in sodium depleted rats. Urinary kinin excretion was increased during infusion of MK 421, SA 446 or captopril in sodium depleted rats, whereas no significant change was found in sodium repleted rats. Thus the present results suggest that renal prostaglandin E system may not be essential for the hypotensive effect of these inhibitors. In addition, the greater hypotensive effect of these inhibitors in sodium depleted rats may be in part due to stimulated renal kinin system.

3-Mercaptopropionic Acid↗
PubMed1987

The role of food intake on gastric mucosal growth and gastrin receptors during pregnancy and lactation.

We examined the effects of pregnancy and lactation on mucosal growth and the numbers and affinity of gastrin receptors in the oxyntic gland mucosa in rats and compared these with changes in serum gastrin levels and food consumption. Gastric mucosal DNA, RNA, and protein contents were significantly increased during lactation. These changes were not observed in either pregnant or nonlactating rats which had given birth at the same time as the lactating animals. The gastrin-binding capacity of a membrane fraction of the oxyntic mucosa was also increased at the corresponding periods in lactating rats (Days 7, 15, 20). Scatchard plot analysis revealed that the number of gastrin receptors was significantly increased without any change in affinity. Food consumption and levels of serum gastrin remained unaltered in pregnant and non-lactating rats compared to virgin controls, but were significantly increased in lactating rats. Increased serum gastrin levels and gastrin binding capacities in lactating rats (Day 15) were abolished by preventing increased food consumption by means of pair feeding. The results demonstrate that the number of gastrin receptors in the oxyntic mucosa increases during lactation in rats. This increase is probably due to hypergastrinemia caused by increased food intake. The increased number of gastrin receptors may be involved in the mechanism of hypertrophic responses of the gastric mucosa in lactating rats.

Animals↗
PubMed1987

[Morphological studies of Escherichia coli in the urine of patients with acute simple cystitis treated with cefbuperazone].

The effects of cefbuperazone (CBPZ) on the morphology of Escherichia coli in the urine of 10 patients with acute simple cystitis were studied by differential interference contrast microscopy and electron microscopy. The urine specimens were collected via catheter before, 5, 10, 15 and 30 minutes after intravenous administration of 0.25 g CBPZ. The minimum inhibitory concentrations for 8 Escherichia coli strains isolated from 8 patients against CBPZ were from 0.05 to 0.2 mcg/ml except one strain. The mean urinary concentrations at 5, 10, 15 and 30 minutes after administration of CBPZ were 274.8, 1181.5, 1343.4 and 931.5 mcg/ml, respectively. Urinalysis improved within 30 minutes after the administration. Filamentous cells of Escherichia coli were observed until 30 minutes after the administration. They had vacuole-like, and spheroplast and bulge formation were also observed in tested cases. CBPZ is suggested to have a high affinity for penicillin-binding protein (PBP) 3 and moderate affinity for PBP 1b and PBP 1a.

Acute Disease↗
PubMed1987

[Tolerance and plasticity against the intracranial pressure in cases of chronic subdural hematoma in the aged brain].

A consecutive series of 94 patients with chronic subdural hematomas (CSDHs) was studied on compensation against intracranial pressure and tolerance, and plasticity from compression of CSDHs, comparing between 47 cases of the aged group over 70 years of age and 47 cases of the younger group under 69 years of age. Better compensation from compression of CSDHs in the aged group was demonstrated from the fact those of long duration from impact to onset of symptoms, few cases with signs of chronic intracranial hypertension and volume of hematoma over 100 ml. But, when CSDHs progressed over 100 ml in size, this compensation mechanism and also tolerance against increased intracranial pressure were deprived. Disturbance of consciousness and anisocoria were shown much more in the aged group on admission. Patients in the aged group demonstrated reduced brain reexpansion and poor clinical recovery during 3 months after surgery. CT performed on 3 months after surgery demonstrated persisting subdural fluid in 63% of cases in the aged group comparing with 8% of those in the younger group. There was significant difference about morbidity between two groups. These study suggests that the plasticity and elastance in the aged brain reduce because of brain atrophy and impairment of cerebral blood flow, then brain reexpansion and clinical improvement may participate in delay regardless of release from compression of CSDHs. It may be urged that the critical age maintaining the plasticity of the brain in cases with SDHs in 75 years of age.

Adolescent↗
PubMed1987

[Cytologic studies of cervical adenocarcinoma].

Seventy three cases of cervical adenocarcinoma, classified histologically according to WHO classification, were cytodiagnostic examined for cellular arrangement, cellular shape, nuclear shape, chromatin pattern and appearance rate of nucleolus. In adenosquamous carcinoma, the observed cancer cells were classified further into five categories and the incidence of each type was clarified. The authors obtained the following conclusions. The cytological findings in cellular arrangement, cellular shape, chromatin pattern and nucleolus findings were closely related with the degree of differentiation of endocervical type adenocarcinoma. Since no substantial cytodiagnostic differences were seen between endometrioid adenocarcinoma and endocervical type adenocarcinoma, it appears to be difficult to differentiate between them. Clear cell adenocarcinoma is characterized by sheet-like cell arrangement, polycrystal cell shape, round nuclei, finely granular chromatin pattern and appearance of macronucleolus. Among them the occurrence of macronucleolus was clearly observed and appeared of high value in making a diagnosis. Adenosquamous carcinoma, showing no characteristic finding in cytology, is proved to have morphological diversity. Careful observation of the intermediate type cancer cells is necessary to presume the histology of adenosquamous carcinoma.

Adenocarcinoma↗
PubMed1986

Difference in mode of inhibition between alpha-D-xylosyl beta-D-fructoside and alpha-isomaltosyl beta-D-fructoside in synthesis of glucan by Streptococcus mutans D-glucosyltransferase.

Both alpha-isomaltosyl beta-D-fructoside and alpha-D-xylosyl beta-D-fructoside show strong inhibition of the synthesis of water-insoluble and water-soluble D-glucans from sucrose by a partially purified preparation of a D-glucosyltransferase (GTase) from Streptococcus mutans 6715; however, the inhibitory modes differ substantially. In the presence of alpha-isomaltosyl beta-D-fructoside, the production of reducing sugars and the consumption of sucrose are remarkably enhanced, compared with a control of sucrose alone. Under these conditions, a large proportion of low-molecular-weight glycan (lmwg) and a series of nonreducing oligosaccharides (both containing D-fructosyl groups or residues) are produced. In contrast, in the presence of alpha-D-xylosyl beta-D-fructoside, the production of reducing sugars and the sucrose consumption are strikingly suppressed, and no lmwg or oligosaccharides are produced. Thus, it may be concluded that alpha-isomaltosyl beta-D-fructoside acts as an alternative acceptor for the D-glucosyl and/or D-glucanosyl transfer reactions of the enzyme, and serves to lessen the formation of insoluble and soluble D-glucan, although it stimulates the transferring activity of the enzyme. On the other hand, alpha-D-xylosyl beta-D-fructoside competitively inhibits the sucrose-splitting activity of the enzyme as an analog to sucrose, and thereby diminishes the synthesis of D-glucan.

Disaccharides↗
PubMed1986

Lysosomal elastase and cathepsin G in beige mice. Neutrophils of beige (Chediak-Higashi) mice selectively lack lysosomal elastase and cathepsin G.

A profound decrease in activities of the two lysosomal serine proteinases, elastase, and cathepsin G, was found in neutrophils of four independent beige mutants. Elastase and cathepsin G activities were assayed with the specific synthetic substrates MeO-Suc-Ala-Ala-Pro-Val-MCA and Suc-Ala-Ala-Pro-Phe-pNA, respectively. The defect is intrinsic to cells of beige mice, since transplantation of bone marrow from normal to mutant mice restored normal proteinase activity, and normal mice transplanted with beige marrow produced neutrophils with a deficiency of proteinase activity. The loss of elastase and cathepsin G activity was confirmed by separation of [3H]diisopropylfluorophosphate-labeled proteins on denaturing gels, which also revealed that other serine proteinases are at normal levels in beige neutrophil extracts. The deficiency of lysosomal proteinase activity appears specific, in that four other common neutrophil lysosomal enzymes, plus the spectrum of major neutrophil proteins are not affected by the beige mutation. The deficiency of proteinase activity is likely not the primary genetic alteration of the beige mutation, since more than one proteinase is affected, and heterozygous F1 mice have normal rather than intermediate levels of both proteinases. The lowered proteinase activity may contribute to the high susceptibility of beige mice and Chediak-Higashi patients to infection.

Animals↗