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Biomedical subjects

S Kamata

Publications and source records attributed to S Kamata.

At least 181 records · Page 10Linked to original sources
PubMed1987

Aldosterone antagonists. 2. Synthesis and biological activities of 11,12-dehydropregnane derivatives.

Several steroid derivatives having the delta 11-pregnane skeleton with a 17-gamma-spirolactone function were synthesized to evaluate their antialdosterone activity and to elucidate the relation between their binding affinity to mineralocorticoid receptor (MR) and their mineralo- and/or antimineralocorticoid activity. Although many of the synthesized compounds showed strong binding affinity for the MR and aldosterone agonist activity, 3-(17 beta-hydroxy-3-oxoandrosta-1,4,6,11-tetraen-17 alpha-yl)propionic acid gamma-lactone exhibited good aldosterone antagonist activity in an in vivo assay. Its in vivo antiandrogenic activity was also found to be relatively weak.

Adrenalectomy↗
PubMed1987

The value of 'Trapezoid Rotation Test' by Contraves computerized rotary chair system.

Trapezoid Rotation Tests using the Contraves computerized rotary chair system were performed in 60 normal subjects and 213 patients with peripheral vestibular disorder. In normal subjects, directional preponderance was not observed. The so-called 'response decline phenomenon' by repeating the tests was not detected and the test results showed good reproducibility. On the other hand, the test results of patients were variable, in close relationship with the state of vertigo, and reflected patient's labyrinthine pathology so accurately that the inspection of the treatment course was possible by this testing system.

Evaluation Studies as Topic↗
PubMed1987

Metabolism of 1-phthalidyl 5-fluorouracil in rat liver and enzyme induction by phenobarbital.

1. When 1-phthalidyl 5-fluorouracil (PH-FU) was incubated with isolated rat hepatocytes, 5-fluorouracil, 2-carboxybenzaldehyde (CBA) and alpha-hydroxymethylbenzoic acid (HMB) were detected as the major metabolites. 2. The enzymes involved in the metabolism of PH-FU, PH-FU hydrolase and CBA reductase are cytosolic and were induced by treating the rats with phenobarbital (PB). Treatment of rats with 3-methylcholanthrene (3-MC) did not affect either enzyme activity. 3. The PB-induced PH-FU hydrolase was inhibited by NADH and several aldehydes, while NAD stimulated the hydrolase and protected it from inactivation by SH reagents. 4. Study in vivo revealed that treatment of rats with PB accelerated the metabolism of PH-FU in the liver and markedly decreased the blood PH-FU after its oral administration to rats, which resulted in reduction of the anti-tumour activity of PH-FU. This activity was not affected by treatment of the rats with 3-MC.

Aldehyde Oxidoreductases↗
PubMed1987

[Combined therapy of bromocriptine, clomiphene citrate and HMG in normoprolactinemic amenorrhea patients who fail to respond to bromocriptine-clomiphene citrate therapy].

The purpose of this study is to investigate the ovulatory effect of the following three methods on 40 patients with normoprolactinemic amenorrhea patients who failed to respond to clomiphene citrate (Cl) alone. Method I is the combined therapy with bromocriptine and Cl (Brc/Cl). Method II is the combined therapy with Brc/Cl and an additional small amount of HMG (less than or equal to 300 IU). Method III is the combined therapy with Brc/Cl and an increased amount of HMG (less than or equal to 1,200 IU) and HCG. The ovulation rate of method I was 57.5% (23/40) in 40 cases, and 55.6% (99/178) in 178 cycles. The pregnancy rate for this method was 23.8% (5/21). Out of the 12 nonrespondent method I cases, 5 additional cases were ovulated by method II and 3 cases were ovulated by method III. The total pregnancy rate was 42.9% (9/21) with these three methods. Seven cases were normal pregnancies, one case was a twin pregnancy and 1 case was an abortion. No other side effects were found in this study. From these results, the combined therapy with Brc/Cl or Brc/Cl + HMG had almost the same ovulatory rate as the HMG-HCG therapy, and fewer side effects.

Adolescent↗
PubMed1987

[Cytology of percutaneous aspiration biopsy of renal angiomyolipoma: a study of 4 cases].

Percutaneous aspiration biopsy of renal angiomyolipoma (AML) was carried out on four patients to investigate the cytological features of AML. The diagnosis was confirmed histologically after the removal of the tumor. The specimen was fixed in 95% alcohol and stained by the Papanicolaou's method. Cells obtained formed clusters in three of four cases. Cells originating from leiomyomatous element of AML varied in their size, but are usually small with small oval nuclei and rich cytoplasm of lacy appearance. The cytoplasm was fragile and the cell border was not clear. Nuclear chromatin was not increased and was distributed diffusely. Fat cells originating from fatty element of the tumor were mature type and obtained from all of three patients who had much typical lipomatous element in the tumor. In conclusion, cytology of aspiration biopsy is useful to establish preoperative diagnosis of AML in such occasions when there are difficulties in differential diagnoses between AML and renal cell carcinoma even by either computed tomography, angiography or ultrasonography.

Adult↗
PubMed1987

Surgical treatment of congenital dilatation of bile duct (choledochal cyst) with technical considerations.

Since the concept of an anomalous junction of the pancreaticobiliary ductal system was introduced, there has been rapid progress in the study of the pathophysiology and the surgical treatment of choledochal cyst, or congenital dilatation of the bile duct. Because of its various disadvantages, cystoenterostomy as a routine procedure for treatment of this condition has been superseded by hepaticoenterostomy after removal of the devastated bile ducts with blocking of communication with the pancreatic ducts. This article describes the technical details of the surgical correction of choledochal cyst.

Adolescent↗
PubMed1986

Effects of dietary histidine and methionine loading in rats with a portacaval shunt.

To elucidate disturbances of brain amine metabolism in hepatic coma, the effects of dietary histidine and methionine loading on the brain levels of amino acids and transmitter amines and on behavior were examined in rats with a portacaval shunt (PCS rats). Surgical construction of a portacaval shunt exaggerated the increase in brain histamine caused by dietary histidine loading 4 weeks after operation. Although the marked increase in the brain level of methionine itself did not affect on the brain levels of catecholamines, serotonin, and histamine, brain level of 5-HIAA was decreased in PCS rats on methionine-enriched diet. Diminished spontaneous activity was observed in PCS rats on either diet, which could not be related to the disturbance of brain amine metabolism caused by excess histidine and methionine. These results indicated that histamine was involved in the derangement of brain amine metabolism in PCS rats, and that direct effect of dietary methionine loading on the brain levels of transmitter amines was not observed in PCS rats. The etiological relation of these substances to hepatic coma should be further investigated.

Amino Acids↗
PubMed1986

Relationships of the molecular structure of aldosterone derivatives with their binding affinity for mineralocorticoid receptor.

The molecular structures of 19-nor-11-deoxycorticosterone (III) and 21-hydroxypregna-4,11-diene-3,20-dione (IV) were determined by X-ray crystallographic analysis and the factors affecting the binding affinities for the mineralocorticoid receptor were examined with six aldosterone derivatives (I-VI) containing these two compounds. The most important factor was found to be the steric one; affinity increased with increasing flatness of the structure. The electronic factor may be a minor influence although a good relationship was found between the affinity and the 13C-NMR chemical shift of the C(5) atom. The factor playing no role in the binding is the hydrophobic one.

Aldosterone↗
PubMed1986

[A simplified quick semi-quantitative determination of urinary estrogen in non-pregnant female: the application for monitoring of follicular maturation at HMG-HCG therapy].

We have developed a simplified quick semiquantitative determination for urinary estrogen in non-pregnant female by utilizing Amberlite XAD-2 and E3 LAIR-KIT. The whole procedure required only 20 minutes. Interassay variance of this method was 10% and intraassay variance was 7%. The recovery was 85%. There was a highly significant correlation between the data obtained by this method and those by RIA (r = 0.944). We applied this method to the monitoring of follicular maturation in the HMG-HCG therapy. Urinary estrogens obtained from 28 anovulatory women (60 cycles) were determined by this method in order to decide the appropriate timing for the HCG injection following the HMG. Our data indicate that it is possible to induce ovulation without the risk of ovarian hyperstimulation syndrome if the HCG was injected on the day when the urinary estrogen level rose to between 70 and 100 ng/ml for 2 consecutive days. This method could well be applied to prospective monitoring in ovulation induction with HMG-HCG therapy.

Anovulation↗
PubMed1986

[Hyperbilirubinemia in neonates associated with total parenteral nutrition].

Clinical studies on the pathogenesis of hyperbilirubinemia (HB) in neonates during total parenteral nutrition (TPN) were performed. From 1971 to 1982, 77 neonates underwent TPN for more than 2 weeks in our institutions. Forty-four of them (57.2%) developed HB during the first one month of life. Twenty eight of 32 patients (87.5%) with dominant infection developed hB, while only 16 of 45 (35.6%) without infection developed HB. Patients with any kind of obstructive intestinal diseases evoked HB more commonly than patients with other diseases. In addition, HB occurred more often in the patients receiving more than 110 kcal/kg/day than those receiving less than that. Gestational ages, birth weights, the duration of TPN and fasting periods had no significant influence on the occurrence of HB.

Age Factors↗
PubMed1986

[Imaging diagnosis of head and neck cancer--diagnosis of laryngeal cancer, hypopharyngeal cancer and cancer of the cervical esophagus by CT x-ray].

Fifty-six patients with laryngeal cancer were examined. The rate of correct diagnosis of clinical staging was 64.3%. Whereas the rate of correct diagnosis of staging by CT was markedly improved, 89.3%. In particular, CT facilitated correct diagnosis of T4. Supraglottic T3 cancer is diagnosed on the basis of deep infiltration or fixation of the hemi-larynx. Disappearance of the pre-epiglottic space or ulcer formation was recognized as a CT finding of deep infiltration. Disappearance of the paraglottic space and dislocation of the arytenoid cartilage were used as the standard for CT findings of laryngeal T3 cancer. CT allowed diagnosis to be made in 84.4% of cases which were pathologically determined to be T4. It can be said that CT is a very effective method for staging diagnosis in patients with laryngeal cancer. Fifty-seven patients with hypopharyngeal cancer and cancer of the cervical esophagus were also examined. When 40 post-surgical patients were compared according to pathological classification of T, the rate of correct diagnosis of clinical staging was 77.5% while that of staging diagnosis by CT was 82.5%. The rate of correct diagnosis by postoperative CT was 80.0% compared with the pathological determination of depth of invasion. The diagnosis of depth of invasion by CT on initial examination is thus an effective means for the determination of prognosis.

Adult↗
PubMed1986

[Relationship between TNM-classification and survival rate in cases of carcinoma of the oral cavity: a comparison between UICC and AJCC TNM staging systems].

We compared TNM classification between UICC and AJCC in the case of oral cancer. T4 definition of UICC was indistinct and AJCC seemed better for T-classification. N-classification of AJCC was rational, since it distinguished between "solitary" and "multiple" nodes. It was inappropriate to equalize T3N0 for T3N1 in stage grouping and also to regard T4N0 as Stage IV because T4N0 had better prognosis than T3N1. Five-year survival rates of all cases were as follows. Tongue (66.7%), floor of mouth (62.4%), buccal mucosa (69.1%), lower gingiva (66.7%), upper gingiva (50.0%), hard palate (62.3%), lip (83.3%).

Humans↗
PubMed1986

[The combined effect of bromocriptine and clomiphene citrate on normoprolactinemic anovulation; the lack of effectiveness of clomiphene citrate treatment alone].

The purpose of this study is to investigate the combined effect of bromocriptine and clomiphene citrate (Cl) treatment on 35 patients with normoprolactinemic amenorrhea who failed to respond to Cl alone. Ovulation was restored by this treatment in 20 of these patients (57.1%), and the pregnancy rate was 26.7%. This treatment was effective in 11 of 15 women with polycystic ovary like syndrome (73.3%). Resting levels of prolactin, estradiol and testosterone in the effective group were significantly higher than those in the non-effective group. As a result of the treatment, the prolactin and LH levels were significantly decreased, and estradiol and progesterone levels were significantly increased in the effective group. Before the treatment, the responsiveness of LH to LHRH in the effective group was significantly higher, but the responsiveness of prolactin to TRH in this group was not significantly higher than that in the non-effective group. After the treatment, the LH-releasing response following a premarin injection in the effective group was significantly higher than that in the non-effective group. The present results indicate that the therapeutic effect of this treatment may be primarily due to the restoration and improvement of the impaired hypothalamo-pituitary system without the suppression of pituitary prolactin secretion.

Adolescent↗
PubMed1985

Aldosterone antagonists. 1. Synthesis and biological activities of 11 beta,18-epoxypregnane derivatives.

Several steroid derivatives having the 11 beta,18-epoxypregnane skeleton, 7, 8, 19, 20, 21, and 31, were synthesized to evaluate their antialdosterone activity. Among them, 3-(9 alpha-fluoro-17 beta-hydroxy-3-oxoandrost-4-en-17 alpha-yl)propionic acid gamma-lactone (31) possessed fairly strong binding affinity for the cytoplasmic mineralocorticoid receptor of rat kidney and exhibited good aldosterone antagonist activity in an in vivo assay. However, its agonistic nature cannot be ignored. The properties of 31 as an aldosterone antagonist were enhanced by its very low to negligible binding affinity for the androgen, progestin, estrogen, and glucocorticoid receptors.

Animals↗
PubMed1985

Deterioration of auditory evoked potentials during cerebellopontine angle manipulations. An interpretation based on an experimental model in dogs.

Evoked action potentials from the internal auditory meatus portion of the cochlear nerve (IAM-EAP's) and brain-stem auditory evoked potentials (BAEP's) from the vertex were simultaneously recorded during cerebellopontine angle (CPA) manipulations (retractions of the cerebellar hemisphere and the cochlear nerve) in dogs. The BAEP changes noted in these dogs were the same as those seen in patients. The IAM-EAP's showed graded deterioration related to BAEP changes. The results are as follows: Prolongation of the I-V interpeak latency of BAEP's, the most common finding during CPA manipulations, is the reflection of prolongation of the I-II interpeak latency, which is caused by conduction impairment or block of the nerve impulses between the extracranial portion of the cochlear nerve and the brain stem. The operative manipulations representing stretch or compression injury to the cochlear nerve in the CPA leads to an acute traumatic cranial nerve root lesion--a retrocochlear lesion. The obliteration of all BAEP components including wave I cannot be caused by conduction block. This is caused by occlusion of the internal auditory artery. Wave I of the BAEP's and the P1-N1 complex of the IAM-EAP's are important indicators of cochlear blood flow during surgical intervention. As possible causes of internal auditory artery obstruction, mechanical distortion of the relationship between the anterior inferior cerebellar artery (AICA) and the internal auditory artery at the junctional portion, mechanical vasospasm of the AICA-internal auditory artery complex, and ensuing no-reflow phenomena are discussed. Evoked action potentials are expected to be a useful intraoperative real-time monitor during CPA surgery that can detect rapid changes derived from cochlear artery insufficency. The real-time aspects can overcome some of the disadvantages of BAEP monitoring.

Animals↗