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Biomedical subjects

M Yoshioka

Publications and source records attributed to M Yoshioka.

At least 271 records · Page 15Linked to original sources
PubMed1994

Structures of novel bufadienolides in the eggs of a toad, Bufo marinus.

In this paper, we report chemical structures of five compounds including four novel polyhydroxylated cardiac steroids in the eggs of a toad, Bufo marinus. These cardiac steroids were purified by high-performance liquid chromatography, and their structures were determined to be 11 alpha,19-dihydroxy-telocinobufagin (I), 11 alpha-hydroxytelocinobufagin (II), 11 alpha,19-dihydroxymarinobufagin (III), 11 alpha-hydroxymarinobufagin (IV) and 19-hydroxytelocinobufagin (V) on the basis of spectral data of nuclear magnetic resonance and mass spectroscopy. All the five compounds showed biological activity, as tested by inhibition of Na+,K(+)-ATPase activity and of [3H]ouabain binding to the receptor on Na+,K(+)-ATPase. This is the first finding of bufadienolides as cardiac steroids in animal eggs.

Animals↗
PubMed1994

The relationship between the sialic acid concentrations in the serum and whole saliva in rats with naturally occurring gingivitis.

Pocket probing depth was correlated with the amount of salivary sialic acid in pilocarpine-stimulated saliva in ODU plaque-susceptible rats (ODUS/Odu) (r = 0.657, P < 0.01), but not with the content of serum sialic acid. There was no difference in the amount of serum sialic acid content between ODUS/Odu and plaque-resistant rats. These results suggest that the amount of sialic acid in the saliva can be a useful index of the severity of periodontal disease.

Animals↗
PubMed1994

Acetylcholine measurement of cerebrospinal fluid by in vivo microdialysis in freely moving rats.

Acetylcholine (ACh) and choline (Ch) levels in rat cerebrospinal fluid (CSF) were determined by in vivo microdialysis (CSF microdialysis) in both halothane-anesthetized and freely-moving rats. The Ch/ACh ratio in CSF perfused with Ringer's solution (30 microliters/30 min) containing 10(-5) M physostigmine, a centrally active cholinesterase inhibitor, was significantly lower than that in unprocessed CSF due to significantly higher ACh levels in the former. The successive measurement on the 2nd and 7th day after the guide cannula implantation demonstrated the feasibility of the CSF microdialysis method for repetitive monitoring of CSF ACh and Ch levels in freely moving rats without extensive tissue damage. Intraperitoneal administration of physostigmine caused an increase in CSF ACh levels, whereas administration of neostigmine, which cannot penetrate into the blood brain barrier, did not. Furthermore, a centrally active acetylcholinergic M1-receptor agonist, AF102B, produced an increase in CSF ACh and Ch levels. Thus, the present study demonstrates that CSF microdialysis is a useful method for evaluating overall central cholinergic activity and investigating the pharmacological effects of various drugs that act via the central cholinergic system.

Acetylcholine↗
PubMed1994

Cushing's disease associated with adrenal myelolipoma, adrenal calcification and thyroid cancer.

A 51-year-old woman with Cushing's disease associated with adrenal myelolipoma is reported. A further characteristic feature was the coexistence of bilateral adrenal calcification and thyroid cancer. Previously several cases of adrenal myelolipoma associated with endocrine dysfunction were reported. The combination of Cushing's disease and adrenal myelolipoma has only been described in two cases of recurrent Cushing's disease but never in an initial occurrence of Cushing's disease. Continued stimulation by excessive adrenocorticotropic hormone (ACTH) not only developed adrenal hyperplasia but also might be involved in the pathogenesis of adrenal myelolipoma.

Adrenal Gland Neoplasms↗
PubMed1994

[Adrenal hepatoid carcinoma producing alpha-fetoprotein: a case report].

A case of left adrenal hepatoid carcinoma is reported. The patient was a 57-year-old male and his chief complaint was general fatigue. Preoperative laboratory data showed markedly increased levels of alpha-fetoprotein (AFP) (30,500 ng/ml) and PIVKA-II (3.01 AU/ml). Both computed tomography (CT) and magnetic resonance computed tomography (MRCT) showed left adrenal tumor (8 x 5 cm). Angiography showed hypervascular tumor over the upper pole of the left kidney. Thoracoabdominal nephro-adrenalectomy was performed. Histological examination demonstrated hepatoid carcinoma of the left adrenal gland. AFP was positive in the tumor cells. The levels of both AFP and PIVKA-II dropped to the normal range postoperatively. Hepatoid carcinoma in the urological field is very rare. As hepatoid carcinoma in the Japanese literature in the urological field, there were only 4 cases of renal tumor, 2 cases of renal pelvic tumor, 2 cases of retroperitoneal space and 1 case of urachal tumor. This is the first report of adrenal hepatoid carcinoma in Japan.

Adenocarcinoma↗
PubMed1994

Ultrasound guided endoscopic neurosurgery--new surgical instrument and technique.

For minimal invasive endoscopic neurosurgery, a mini-caliber endoscope equipped with a useful working channel and its guidance system is basically essential. We developed the device for ultrasound guided endoscopic neurosurgery. A minicaliber fiberscope with an outer diameter of 3.4 mm equipped with 2.5 mm of working channel for forceps, suction, and coagulation probe was developed. A 5 MHz phase arrayed 12 mm ultrasound probe was used as guidance system. A fixation device for the mini-caliber fiberscope and ultrasound probe was also constructed. The surgical procedure is very simple, and can be performed through a 2 cm burr hole. Real-time and a directly visualized image might provide more safety and reliability during brain surgery.

Brain Diseases↗
PubMed1994

Bile salts of the toad, Bufo marinus: characterization of a new unsaturated higher bile acid, 3 alpha,7 alpha,12 alpha,26-tetrahydroxy-5 beta-cholest-23-en-27-oic acid.

The bile salts present in gallbladder bile of the toad, Bufo marinus, were found to consist of a mixture of bile alcohol sulfates and unconjugated bile acids. The major bile alcohol was 5 beta-bufol; 5 alpha- and 5 beta-cholestane-3 alpha,7 alpha,12 alpha, 26-tetrols occurred as the minor bile alcohols. Bile acids of Bufo marinus were cholic acid, allocholic acid, 3 alpha,7 alpha,12 alpha-trihydroxy-5 alpha- and 5 beta-cholestan-26-oic acids, 3 alpha,7 alpha,12 alpha-trihydroxy-5 alpha- and 5 beta-cholest-23-en-26-oic acids, 3 alpha,7 alpha,12 alpha, 26-tetrahydroxy-5 beta-cholestan-27-oic acid, and a C27 bile acid which has not been previously described. By chromatographic behavior, mass spectral data, and identification of the products of catalytic hydrogenation and ozonolysis, the structure of the new higher bile acid was elucidated as 3 alpha,7 alpha,12 alpha,26-tetrahydroxy-5 beta-cholest-23-en-27-oic acid. The bile salt pattern of Bufo marinus closely resembles that of Bufo vulgaris formosus, except for the absence of 3 alpha,7 alpha,12 alpha-trihydroxy-5 beta-cholest-22-ene-24-carboxylic acid, the major bile acid of the latter toad.

Animals↗
PubMed1994

[The usefulness of transcutaneous gas monitoring during hemorrhagic shock; discrepancy between the two transcutaneous gas tensions of anterior thorax and femur].

We measured transcutaneous gas tensions of both anterior thorax and femur. The differences between the two transcutaneous gas tensions were compared, as well as the relationship between the two transcutaneous and mixed venous blood gas tensions, in 10 dogs during hemorrhagic shock. The changes in femoral transcutaneous gas tensions correlated better with the changes in mixed venous gas tensions. The correlation between the two transcutaneous gas tensions were fairly good (oxygen tensions; r = .827, carbon dioxide tensions; r = .867). However, the discrepancy between the two gas tensions became greater in severe shock. Hence, oxygen tensions became smaller and carbon dioxide tensions became greater on femur than on anterior thorax. This indicates the possibility of "maldistribution of blood flow", which has already been detected between vital organs and skin, also exists between peripheral and central skin. Therefore, transcutaneous gas tensions should be monitored at peripheral skin, where gas tensions show greater changes and reflect systemic perfusion precisely than at central skin, during shock.

Animals↗
PubMed1994

Preoperative chemotherapy for esophageal cancer based on chemosensitivity testing.

To examine the role and significance of in vitro chemosensitivity testing on cells cultured from endoscopic biopsy specimens, we evaluated outcomes in 57 patients with squamous cell carcinoma of the thoracic esophagus. Over 3 1/2 years, 57 patients were treated with a single course of preoperative combination chemotherapy based on the results of chemosensitivity testing utilizing eight antineoplastic agents. A radiologically evident response (partial response) was seen in 23 patients (40.4%) and histologic effects on grade IIb tumors were seen in six patients (10.5%). The median survival time of all 57 patients was 16.3 months. The median survival time of nine patients who received palliative resection was 4.5 months. The median survival times after curative resection of the 19 patients with a partial response and 29 patients with no response were 27.7 months and 17.3 months, respectively (p < 0.009). The most frequent combination chemotherapy used was cis-dichlorodiammine platinum (II) vindesine/5-fluorouracil, and a high rate of response was noted after therapy with etoposide and 4'-D-tetrahydropyranyl-doxorubicin. Chemosensitivity testing appears to be useful in selecting preoperative chemotherapeutic agents for patients with esophageal cancer, decreasing tumor recurrence after surgery and resulting in more partial responses than conventional chemotherapy.

Adult↗
PubMed1994

Refined mapping of a gene responsible for Fukuyama-type congenital muscular dystrophy: evidence for strong linkage disequilibrium.

Fukuyama-type congenital muscular dystrophy (FCMD), the second most common form of childhood muscular dystrophy in Japan, is an autosomal recessive severe muscular dystrophy associated with an anomaly of the brain. After our initial mapping of the FCMD locus to chromosome 9q31-33, we further defined the locus within a region of approximately 5 cM between loci D9S127 and CA246, by homozygosity mapping in patients born to consanguineous marriages and by recombination analyses in other families. We also found evidence for strong linkage disequilibrium between FCMD and a polymorphic microsatellite marker, mfd220, which showed no recombination and a lod score of (Z) 17.49. A "111-bp" allele for the mfd220 locus was observed in 22 (34%) of 64 FCMD chromosomes, but it was present in only 1 of 120 normal chromosomes. This allelic association with FCMD was highly significant (chi 2 = 50.7; P < .0001). Hence, we suspect that the FCMD gene could lie within a few hundred kilobases of the mfd220 locus.

Chromosome Mapping↗
PubMed1994

[Pathogenesis of neurological disorders in AIDS].

Impairment of the central nervous system (CNS) and peripheral nervous system (PNS) is common during the human immunodeficiency virus type 1 (HIV-1) infection. There are evidences of activated immune reactions in the CNS and PNS of patients with acquired immunodeficiency syndrome (AIDS). The expression of HIV-1 predominantly in monocyte/macrophage lineage cells strongly suggests immunopathogenetic mechanisms. Possible mechanisms of neuronal and glial cell damage include calcium dependent excitotoxicity by HIV-1 envelope protein, N-methyl-D-aspartate (NMDA) receptor-mediated neurotoxicity of quinolinic acid, injury of oligodendrocytes by tumor necrosis factor--alpha, cell injury by HIV-1-specific cytotoxic T cells, and apoptosis of oligodendrocytes or neurons. These mechanisms are not mutually exclusive. Multiple factors may be involved in the pathogenesis of HIV-1-associated neurological diseases.

AIDS Dementia Complex↗
PubMed1994

[Development of a troublesome behavior scale (TBS) for elderly patients with dementia].

A rating scale for assessing troublesome behavior associated with dementia illnesses was developed. This instrument, named the troublesome behavior scale (TBS), is designed to be completed by family and professional caregivers. It is comprised of 14 questions assessing a variety of types of disruptive or burdensome behavior. Two of the 14 questions differ in their assessment for outpatients and that for inpatients. Each of the 14 items is rated with 5 possible responses corresponding to the frequency of the behavior in the preceding month (from 0 = never, to 4 = once every day or more). Thus, higher scores indicate more disturbance. The TBS was administered to 146 outpatients and 167 inpatients with dementia based on the DSM III-R criteria in order to test its reliability and validity. The data were analyzed separately for outpatients and inpatients. The reliability of the scale, based on calculation of perfect agreement rates and kappa values, indicated high test-retest and inter-rater reliability for both samples. Validity, by confirmatory factor analysis of the data from the outpatients, revealed three main factors, namely, "behavior toward caregivers", "self-absorbed behavior" and "elaborate behavior". The same analysis of data from inpatients resulted in a different set of three factors: "behavior interfering with care work", "behavior necessitating watchful protection" and "behavior resulting in missing articles". From these findings TBS appears to be a reliable and valid instrument for assessing troublesome behavior of patients with dementia.

Aged↗
PubMed1994

[Development of an assessment of basic care for the demented (ABCD)].

A rating scale measuring care status related to assistance with basic ADL for demented patients was developed. This instrument, named the ABCD, is designed to be completed by family and professional caregivers, and consists of two subscales assessing the level of difficulty of help with the ADL (difficulty scale) and the reasons why assistance is needed (reason category). In the difficulty scale, each of 6 items is rated with 4 possible responses corresponding to the degree of physical assistance from the caregiver and of the patient's cooperation with the assistance. In the reason category, for 5 activities excluding voiding, the reason is assessed with the following three possible responses: A; physical disability, B; disability in motivation and/or so-called apraxia, C; a combination of A and B. The ABCD was administered to 124 outpatients and 203 inpatients with dementia based on the DSM III-R criteria in order to test its reliability and validity. The data from the out- and inpatient samples were analyzed separately. The reliability study of the two subscales based on calculation of perfect agreement rates and kappa values indicated high test-retest and inter-rater reliability for both samples. The Cronbach alpha values of the difficulty scale were also high. As to the validity of the difficulty scale, there was a significantly high correlation between the score obtained with this scale and the results of two established assessment instruments. For the outpatients, logistic regression analysis revealed that the score obtained with this scale was the only predictor of institutionalization and mortality within 1 year after the baseline examination.(ABSTRACT TRUNCATED AT 250 WORDS)

Activities of Daily Living↗
PubMed1993

Inhibitory action of N omega-nitro-L-arginine methyl ester on in vivo long-term potentiation in the rat dentate gyrus.

Recent in vitro observations have led to the suggestion that nitric oxide (NO) plays a modulatory role in the expression of long-term potentiation (LTP). We investigated whether an NO synthesis inhibitor, N omega-nitro-L-arginine methyl ester (L-NAME), affects the generation of LTP in anesthetized rats in vivo. Administration of L-NAME (0.1 and 1 nmol, i.c.v.) suppressed the magnitude of LTP dose dependently in the dentate gyrus of anesthetized rats. Co-injection of L-arginine, which interferes with the inhibitory action of L-NAME on NO synthesis, reversed these effects, whereas there was no reversal in rats that received co-administration with D-arginine. These results provide further support for the hypothesis that NO plays a modulatory role in the expression of synaptic potentiation.

Animals↗
PubMed1993

Opioid receptor regulation of 5-hydroxytryptamine release from the rat hippocampus measured by in vivo microdialysis.

The modulation of serotonin (5-HT) release by opioid receptors in the hippocampus of the awake, unrestrained rat was evaluated by use of in vivo microdialysis. The hippocampus was perfused with Ringer's solution (2 microliters/min), and extracellular levels of 5-HT and its major metabolite, 5-hydroxyindoleacetic acid (5-HIAA) were estimated by assaying their concentration in the dialysate by HPLC-ECD. Addition of potassium (K+, 60 and 120 mM) to the perfusate evoked a concentration-dependent release of 5-HT, but did not alter extracellular 5-HIAA levels. Co-perfusion of morphine (0.1 to 10 microM) with K+ (120 mM) produced a concentration-dependent reduction of 5-HT release. Naltrexone (0.03 to 3 mg/kg, i.p.), a relatively selective mu-opioid receptor antagonist, blocked in a dose-dependent manner the morphine (10 microM)-induced inhibition of 5-HT release. Naltrexone alone did not alter significantly either extracellular 5-HT levels or the release of 5-HT evoked by K+. Neither co-perfusion with [D-Pen2, D-Pen5]-enkephalin (DPDPE, 1 to 10 microM), an agonist selective for delta-opioid receptors, nor with U-69593 (10 microM), an agonist selective for kappa-opioid receptors, modified the K+ (120 mM)-evoked release of 5-HT. These findings indicate that mu-opioid receptors modulate the physiological release of 5-HT from serotonergic neurons in the rat hippocampus.

Analgesics↗