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Biomedical subjects

T Okamura

Publications and source records attributed to T Okamura.

At least 559 records · Page 31Linked to original sources
PubMed1989

Prognostic factors in gastric cancer with serosal invasion. Univariate and multivariate analyses.

Univariate and multivariate analyses of possible prognostic factors were carried out on data from 142 patients who had undergone curative resection for a carcinoma of the stomach invading beyond the muscularis propria. In the univariate analysis, factors including age, size of cancer, gross form, depth of penetration, lymph node metastasis, lymphatic invasion, width of serosal invasion, mode of invasion, volumetric shape of invasion, and stage had an individual prognostic significance. The multivariate analyses indicated that stage, lymph node metastasis, and depth of penetration were the most significant prognostic factors and that the prognosis in cases of obvious serosal invasion, or those with secondary or tertiary nodal involvement, was poor. For such patients, we prescribe postoperative intensive chemotherapy, even when a "curative" operation is done.

Adenocarcinoma↗
PubMed1989

Different involvement of endothelium-derived relaxing factor and prostacyclin in vasodilator response to bradykinin in isolated dog blood vessels.

The study presented so far demonstrates that there is a heterogeneity in the mechanisms of vasodilator action of BK in various dog blood vessels (coronary vs mesenteric artery, and mesenteric artery vs vein). The different mechanisms underlying the BK-induced vasodilatation are summarized in Fig. 3. Three mechanisms are at least involved; 1) EDRF-release from endothelial cells which may not be mediated by B1 receptor, but presumably by B2 receptor, 2) PGI2-release from endothelial cells, 3) PGI2-release from smooth muscle (subendothelial) cells. The PGI2-release may be mediated by B1 receptor. Vasodilatation caused by BK is mediated via "1" in coronary arteries, "2" + "3" in mesenteric veins, and "1" + "2" + "3" in mesenteric and renal arteries in the dog. Another reasons for the differences in the BK-induced vasodilatation may be different number or sensitivity of BK receptors located on the endothelial and smooth muscle cells, or the responsiveness of the vascular smooth muscle cells to the intermediate vasodilator substances and BK itself.

Animals↗
PubMed1989

Postoperative adjuvant chemotherapy inhibits early recurrence of early gastric carcinoma.

Data on 300 patients with early gastric carcinoma who underwent curative resection were analyzed for the suppressive effects of postoperative adjuvant chemotherapy on early recurrences. Retrospective grouping was done as follows: no chemotherapy (NC) group (169 patients), mitomycin C (MMC) group (108), and another group (23). In all, 24 patients (16 in the NC, 6 in the MMC, and 2 in the other group) who died of other diseases within 5 years after surgery were excluded. Therefore, data on 153 individuals in the NC and 102 in the MMC group were analyzed. The recurrence rate in patients with Pen A type carcinoma, with a propensity toward an early recurrence in the liver, was 37.5% in the NC and 9.1% in the MMC group. Among 27 Pen A type patients, 3- and 4-year survival was significantly higher in those receiving MMC (100%) than in those given NC (62.5%). Recurrences in the liver occurred in 6/14 of the NC patients within 3 years after surgery, whereas there were no recurrences in 11 MMC patients. Thus, the postoperative adjuvant chemotherapy with mitomycin-C has an inhibitory effect on early recurrence in patients with Pen A type early gastric carcinoma.

Carcinoma↗
PubMed1989

Comparison of enzyme phenotypes in human bladder tumours and experimentally induced hyperplastic and neoplastic lesions of the rat urinary bladder. A combined histochemical and immunohistochemical approach.

The expression of a number of enzymes involved in drug metabolism, membrane function etc. was compared in hyperplastic and neoplastic lesions of the rat bladder and in human bladder tumours. Transitional cell carcinomas (TCC) in both rat and Man were characterized by decreased alkaline phosphatase (ALP) and increased gamma-glutamyl transpeptidase (GGT), beta-glucuronidase (beta-G1), succinate dehydrogenase (SD) and glucose-6-phosphate dehydrogenase (G6PD) activities. In addition, binding for antibodies specific for different cytochrome P-450 species (UT50, PB3a, MC1, MC2) and microsomal epoxide hydrolase (mEHb) was elevated in both murine and human tumours. Comparison of the enzyme phenotype in hyperplastic lesions induced by freeze ulceration or uracil administration with that in preneoplastic papillary or nodular hyperplasia (PNH) and TCC suggested, however, that most of the alteration in enzyme content or activity was non-specific and related to requirements for epithelial cell proliferation. On the other hand, the decreased ALP, and increased GGT and beta-G1 activity appeared more directly related to neoplastic transformation. The results suggested that qualitative differences exist between reactive hyperplasia and preneoplastic or neoplastic lesions in the urinary bladder. The finding of increased cytochrome P-450, in clear contrast to the reduction characteristic of preneoplastic hepatic lesions, may be important with regard to the observed difference in neoplastic transformation between the bladder and liver in response to drug metabolising enzyme inducers.

Alkaline Phosphatase↗
PubMed1989

Preventive effect of traditional herbal medicine, shosaiko-to, on danazol-induced hepatic damage.

The incidence of the hepatic damage during treatment with danazol (D), indicated by increased serum GOT, GPT and LDH levels, has been shown to be high especially in Japan. Thus, the preventive effect of the traditional herbal medicine, shosaiko-to (SS) was investigated in the administration of D and SS for 16 weeks (D + SS group, N = 9) and the pre-administration of SS for about 4 weeks followed by D and SS for 16 weeks (SS----D + SS group, N = 15). The incidence of serum GOT, GPT and LDH levels of more than normal range during the administration of danazol in the D + SS group was similar to that in the previous study of the administration of D alone. But it was significantly lower in the SS----D + SS group than the D + SS group. The mean levels of serum GOT and GPT were much lower in the SS----D + SS group than the D + SS group throughout the administration of danazol and the difference was significant at 8, 10 and 12 weeks in serum GOT levels and at 4 weeks in serum GPT levels. These results indicate that the pre-administration of SS has great efficacy in the prevention of danazol-induced hepatic damage.

Adult↗
PubMed1989

Action of atrial natriuretic peptide (ANP) on dog cerebral arteries: evidence that neurogenic relaxation is not mediated by release of ANP.

1. Atrial natriuretic peptide (ANP) (10(-9) to 10(-8) M) produced a concentration-related relaxation in helical strips of dog cerebral arteries partially contracted with prostaglandin F2 alpha. The relaxation was not affected by treatment with ouabain, quinidine, oxyhaemoglobin, methylene blue, or removal of endothelium. 2. Relaxations induced by nicotine or transmural electrical stimulation were not reduced in arteries in which tachyphylaxis to ANP had developed. 3. In arteries exposed to Ca2+-free media under severe hypoxia, contractions due to prostaglandin F2 alpha and Ca2+ were attenuated by treatment with ANP, whereas the reoxygenation-induced contraction was unaffected. 4. The results suggest that ANP does not mediate neurogenic relaxation of dog cerebral arteries. The ANP-induced relaxation is not associated with activation of the sodium pump but is due to an inhibitory action on the release and influx of Ca2+, probably as a result of stimulation of guanylate cyclase.

Animals↗
PubMed1989

Growth survey of schoolchildren in Akita Prefecture: preliminary report.

This report presents the results of a preliminary epidemiological study of growth in Akita prefecture. Data were collected from 5672 pupils from nine elementary schools in the region. Previous epidemiological investigations of growth have set the screening standard for growth retardation at -2.58 SD below the mean. On the basis of this figure it was estimated that 22 out of the 5672 pupils screened in this preliminary study (0.39%) would suffer from growth retardation. When this standard is applied to all 102,193 elementary school students in Akita prefecture, 396 children in the region are estimated to be growth retarded. An epidemiological investigation in Niigata prefecture in 1985 found that 10.5% of growth-retarded patients suffered from growth hormone deficiency. While this percentage is known to vary between different studies and with different methods of statistical analysis, application of this rate to the estimated number of 396 growth-retarded patients in Akita prefecture suggests that there may be 41 or 42 patients with growth hormone deficiency.

Body Height↗
PubMed1989

Sibs with tetrasomy 18p born to a mother with trisomy 18p.

We report a family with an 18p trisomic mother and two 18p tetrasomic daughters. The mother is phenotypically normal and healthy, but with an unusual type of trisomy 18p: 47,XX,del(18)(pter----p11.21),+i(18p) de novo. The older sister has microcephaly, mental retardation, an asymmetrical and peculiar face with low set ears, pinched up nose, high arched palate, small mouth, micrognathia, tapering fingers, asymmetrical length of legs, and an asthenic body. The younger sister was stillborn with extensive defects of the skull, congenital hydrocephalus, severe facial anomalies, and lumbosacral meningocele. Both daughters have inherited one normal chromosome 18 and an isochromosome 18p from their mother, and one normal chromosome 18 from their father. Although one quite similar family has been reported, to the best of our knowledge there have been no reports of families in which two daughters with tetrasomy 18p syndrome have been born to a mother with trisomy 18p with isochromosomes.

Abnormalities, Multiple↗
PubMed1989

Effect of traditional herbal medicine, shakuyaku-kanzo-to on total and free serum testosterone levels.

The effect of the traditional herbal medicine, Shakuyaku-Kanzo-To (SK), which contains Shakuyaku (S) and Kanzo (K) in equal amounts, on serum testosterone levels was investigated in androgen-sterilized rats. They were given orally SK [0, 22.5, 45, 90 and 180 mg/kg body weight (b.w.)] and S or K (0, 11.25, 22.5, 40 and 90 mg/kg b.w.) in 2 ml of water daily for 2 weeks. Dose-dependent decreases in free serum testosterone (T) levels were found in the administration of SK. Total serum T levels in the administration of SK and S decreased in a dose-dependent manner. K decreased total serum T levels slightly in 11.5 and 22.5 mg/kg doses but showed the dose-dependent increase in much higher doses, the extent of which was much less than that of the decrease in S. Serum estradiol/T (E2/T) ratios were significantly elevated in 45 to 180 mg/kg doses of SK, 90 mg/kg dose of S and 11.25 to 90 mg/kg doses of K. Serum LH and FSH levels were not changed by SK, S and K. Oophorectomized rats were similarly given SK (0, 90 and 180 mg/kg b.w.) and S or K (the half doses of SK). There were no changes in serum T, LH and FSH levels in all given doses. Thus, one of the mechanisms for SK to lower serum T levels is the direct action on the ovary to stimulate the aromatase activity, resulting in decreasing the T secretion and this is the additive effects of S and K.

Animals↗
PubMed1989

Endothelium-dependent and -independent responses to vasoactive substances of isolated human coronary arteries.

In epicardial conduit coronary artery strips obtained during autopsy within 2.5 h after death, relaxations induced by low concentrations of histamine were reversed to contractions by removal of endothelium, whereas those caused by bradykinin, substance P, and Ca2+ ionophore A23187 were almost abolished. In the artery strips with intact endothelium, which responded to histamine, bradykinin, and substance P with moderate or marked relaxations, acetylcholine elicited contractions. Endothelium denudation failed to potentiate the contractile response to acetylcholine and serotonin. Relaxant responses to histamine, bradykinin, and substance P did not significantly differ in coronary arteries from adults (35-48 yr old) and seniors (63-82 yr old). Two strips from a 2-mo-old male responded to acetylcholine only with contractions, and their responses to the vasodilators were not greater than those seen in the adult and senior arteries. Histamine increased guanosine 3',5'-cyclic monophosphate (cGMP); the increments did not differ in the arteries from adults and seniors. It may be concluded that endothelium is a major site for relaxant actions of histamine, bradykinin, and substance P, whereas muscarinic receptors, if any, in endothelium do not play an important role in the generation of relaxing factor from human coronary arteries. The endothelium-dependent relaxations do not appear to be altered with increasing age or in the arteries with slight atherosclerotic changes.

Acetylcholine↗
PubMed1989

Endothelium-dependent and -independent mechanisms of action of acetylcholine in monkey and dog isolated arteries.

In helical strips of monkey coronary and mesenteric arteries and dog mesenteric arteries partially contracted with prostaglandin (PG)F2 alpha, the mechanism of action of acetylcholine (ACh) has been analyzed by the use of pharmacological antagonists and by the endothelium-derived relaxing factor (EDRF) bioassay and the 6-keto PGF1 alpha radioimmunoassay. In conclusion, ACh releases vasodilator substance(s) from endothelium (EDRF) and also PGs from subendothelial tissues. Vasoconstrictor PGs appear to counteract the dilator action of EDRF in monkey coronary arteries, whereas vasodilator PG, possibly PGI2, appears to facilitate the relaxation caused by EDRF in monkey and dog mesenteric arteries.

6-Ketoprostaglandin F1 alpha↗
PubMed1989

Role of endothelium in the response to prostaglandin H2 in isolated dog arteries.

Prostaglandin (PG) H2 produced a transient contraction followed by a relaxation in helical strips of dog coronary, mesenteric and renal arteries contracted with PGF2 alpha. The contraction was in the order of mesenteric greater than renal greater than coronary artery. Removal of endothelium abolished the contraction in these arteries and significantly potentiated the relaxation only in mesenteric arteries. The relaxation was greater in mesenteric arteries than in renal and coronary arteries, denuded of endothelium. PGI2-induced relaxations were not influenced by endothelium denudation. In the arteries contracted with K+, PGH2-induced relaxations were attenuated, compared to those contracted with PGF2 alpha. Treatment with ONO3708, an antagonist of vasoconstrictor PGs, abolished the PGH2-induced contraction and potentiated the relaxation in the K+-contracted arteries. The relaxant response was suppressed by diphloretin phosphate, a PG receptor antagonist, as was the response to PGI2. PGH2-induced contractions in dog coronary, mesenteric and renal arteries would be due to vasoconstrictor PGs produced preferentially in the endothelium. However, production of PGI2 from PGH2 in endothelial and subendothelial tissues do not appear to differ.

Animals↗
PubMed1989

Mechanisms of action of eperisone on isolated dog saphenous arteries and veins.

Effects of eperisone, an antispasmodic in skeletal muscle, were investigated in helical strips of dog saphenous artery and vein. Eperisone relaxed saphenous arteries and veins previously contracted with norepinephrine, serotonin, acetylcholine, K+, or Ba2+; but in contrast, it produced contractions in the blood vessels contracted with prostaglandin (PG) F2 alpha. Treatment with eperisone attenuated the contractions induced by norepinephrine and serotonin in the arteries and those by clonidine and phenylephrine in the veins. Eperisone inhibited angiotensin II-induced relaxations, mediated possibly by endogenous PGI2, but did not alter relaxations caused by exogenous PGI2. Treatment with eperisone (10(-5) M) potentiated the contractile response to electrical stimulation of adrenergic nerves; the potentiating effect was suppressed by yohimbine. The eperisone-induced contraction in PGF2 alpha-contracted arteries was inhibited by treatment with indomethacin or aspirin, although cyclooxygenase activity was not inhibited by eperisone. These results may indicate that eperisone blocks postjunctional alpha 1- and alpha 2-adrenergic, muscarinic, serotonergic receptors and prejunctional alpha 2 adrenoceptors and reduces PGI2 synthesis via a mechanism other than cyclooxygenase inhibition.

Animals↗
PubMed1989

AV nodal reentrant tachycardia with Mahaim fiber conduction.

Paroxysmal tachycardia with widened QRS complexes was found in a 46-year-old woman. In sinus rhythm, the patient had electrocardiographic evidence of type B preexcitation with a left bundle branch block pattern. The resting PR interval (160 msec) and A-H interval (100 msec) were within normal limits, but the H-V interval (10 msec) was abnormally short. Programmed atrial extrastimuli at progressively shorter coupling intervals resulted in sudden prolongation of the A-H interval from 120 msec to 250 msec, and the His bundle activities became incorporated just after initiation of the QRS complexes. The QRS morphology was changed but the change was minimal, and atrial echo beats or sustained tachycardia with wide and preexcited QRS complexes were elicited. It is postulated that the site of reentry is within the AV node with preexcitation occurring as the result of conduction in an anomalous nodoventricular pathway.

Cardiac Pacing, Artificial↗
PubMed1989

[Clinical studies on rotation and translation of mandibular head in internal derangements of the temporomandibular joint with dual axis graph].

The present study was aimed at establishing the standards for functional diagnosis of the internally deranged TMJ by analyzing the rotary and gliding movements of the mandibular head. The subjects were patients with anterior displacement of the articular disc (ADD) and normal persons. The rotary movements were examined by use of a simplified condylar movement recorder and a specially developed dual axis graphic system. The findings are as follows: 1. In the patients and the normal persons as well, the rotary movements near the intercuspal contact position (ICP) showed a tendency to increase anteriorly until the mandibular head moved up to 6 mm from the ICP. However, in both patients with ADD with reduction and without reduction, the rotary movements near the ICP were significantly large as compared with those in the normal subjects. 2. In the ordinary persons, the rotary movements near the ICP were mostly larger during the closing movements than during the opening movements. In both patients with ADD with reduction and without reduction, the rotary movements were larger during the opening movement than during the closing movement. 3. The results of our study suggest that the dual axis graph could be a useful tool in examining the rotary movement of the mandibular head.

Humans↗
PubMed1989

[A study on accumulation of cholesterol in rat prostate].

An experimental model of prostatic hypertrophy was created by freezing the urethra at the opening of the ventral prostate in rats and administering a cholesterol-rich diet to induce cholesterol accumulation. Four-week-old Fisher rats were divided into a control group, a cholesterol-rich diet group (by adding 1% cholesterol to the diet), a frozen group, and a frozen and cholesterol-rich diet group, and were reared for 5 months. The animals were killed, and the ventral prostate was removed, weighed, and the lipid was extracted. Cholesterol content was measured by an enzymatic method. A cholesterol-rich diet without freezing had no effects on the ventral prostate, and after freezing alone, the weight of the prostate was smaller than that of the control group. However, in the group cholesterol-rich diet after urethral freezing, the cholesterol content per mg of tissue increased. This indicates that cholesterol accumulation can be induced in the prostate by administering a cholesterol-rich diet after creating the proper secretory disturbance.

Animals↗