Biomedical subjects

M Yamaguchi

Publications and source records attributed to M Yamaguchi.

At least 937 records · Page 52Linked to original sources

PubMed1994

[A case of mefloquine-resistant Plasmodium falciparum malaria with convulsion after antimalarial treatment].

We report a case of 40-year-old with chloroquine- and mefloquine-resistant Plasmodium falciparum. He had a single grand mal seizure 37 days following retreatment with quinine intravenously, which resulted in rapid clearance of fever and parasitemia, in addition to mefloquine. He had a long history of seizures, which were well controlled by phenytoin. Because he has never had such a seizure before and computerized tomographic scanning of the brain after admission showed no abnormal findings which caused convulsions, it seemed to be an adverse reaction caused by antimalarial drugs. It is possible that a double or triple combination treatment for the emergence of multiresistant falciparum malaria might more frequently produce severe side effects, such as psychiatric reactions and convulsions. This case suggests that physicians must have a long follow-up period for chronic toxicity of antimalarial drugs, especially after using drug combinations for falciparum malaria.

Adult↗

PubMed1994

[The first report of traveler's diarrhea associated with a newly described toxigenic Vibrio cholerae O139 strain in Japan].

A newly described Vibrio cholerae O139 was isolated from a patient who had traveled in India on April 1993. The patient experienced 5 to 6 watery diarrhea per day after he returned to Japan. The isolated strain registered as K111 did not agglutinate with O1-O138 antiserum and agglutinated with O139 antiserum. This strain resembled V. cholerae O1 strain in biochemical characters and had ctx and zot, although was resistant to the vibrio static agent O/129. This is the first report of cholera-like illness by the newly described toxigenic V. cholerae O139 strain in Japan.

Base Sequence↗

PubMed1994

[Yersinia enterocolitica serotype O:8 infections at the Hirosaki district in Aomori Prefecture from 1984 to 1991].

During the period from January 1984 to December 1991, 118 strains of Yersinia enterocolitica were isolated from the specimens which were requested for bacterial examination from various medical practitioners. The results of bacteriological examination of these isolates showed that 11 of Y. enterocolitica serotype O:8 sporadic infections were confirmed at Hirosaki district in Aomori Prefecture. Of the eleven isolated strains, nine were from feces, two were from contents of extracted appendix. These strains were biovar (Wauters) 1, harboring 42 megadalton virulence plasmid, positive for autoagglutination and calcium dependency. Patients were under fifteen years old except one case of a 45 year old. Seven patients were living in the inter-mountain area, three in the urban area and one in the plain area. The infectious source was not found.

Adolescent↗

PubMed1994

Adrenal adenomas: characteristic hyperintense rim sign on fat-saturated spin-echo MR images.

PURPOSE: To determine whether adrenal adenomas can be differentiated from metastases on fat-saturated magnetic resonance (MR) images. MATERIALS AND METHODS: Twenty-eight adrenal adenomas and 20 metastatic lesions were imaged at 1.5 T by means of fat-saturated T1- and T2-weighted and gadolinium-enhanced T1-weighted sequences. The authors evaluated visually whether structures of high signal intensity (hyperintense rim sign) could be observed in the outer margin of the adrenal masses. RESULTS: Twenty-six of 28 adrenal adenomas revealed the hyperintense rim sign on at least one kind of fat-saturated image, compared with only one of 20 metastases. The sensitivity of the hyperintense rim sign as suggestive of adrenal adenoma was 92%, specificity was 95%, and overall accuracy was 94%. CONCLUSION: The hyperintense rim sign is characteristic of adrenal adenomas. Thus, adrenal adenomas can be differentiated from metastases by means of this new imaging sign on fat-saturated MR images.

Adrenal Cortex Neoplasms↗

PubMed1994

Two distinct types of reticular cells in the pig sheathed artery.

The morphology of reticular cells of the sheathed arteries, in the red pulp of pig spleen, was studied by using transmission electron microscopy; and their histochemical reactivity with periodic acid-thiocarbohydrazide-silver proteinate (PA-TCH-SP). The phagocytic ability was evaluated by injecting colloidal carbon into the splenic artery. Reticular cells of the sheathed arteries were classified as type I and type II cells. Type I cells have a nucleus with scanty chromatin, and the cytoplasm reacts positively to PA-TCH-SP. The PA-TCH-SP-positive granules are considered to be subunits of beta-glycogen particles based on their morphological features. Type II cells have a nucleus with abundant chromatin and are not stained by PA-TCH-SP. Both types of reticular cells are connected with reticular fibers. Results of the colloidal carbon injection showed that type I reticular cells did not ingest carbon particles during the time frame of the experiment, whereas type II reticular cells are phagocytic and ingested carbon.

Animals↗

PubMed1994

Liver microsomal mixed-function oxidases in response to polyunsaturated/saturated and n-6/n-3 fatty acid ratios of dietary lipids in rats.

The effects of various polyunsaturated/saturated (P/S; 0.29-2.74) and n-6/n-3 (0.49-11.21) ratios of dietary fatty acids and of phenobarbital (PB) stimulation on the activity of liver microsomal mixed-function oxidase (MFO) system were studied in rats using a combination of palm oil, safflower oil and fish oil concentrate. When the n-6/n-3 ratio was kept constant (4.6-4.9) without induction by PB, the highest P/S ratio (2.74) tended to increase the basal PB-uninduced MFO activities; while the PB-induced MFO activities were elevated as the dietary P/S ratio increased. This definitely indicates the role of both n-6 and n-3 polyunsaturated fatty acids (PUFAs) in the elevation of MFO activities with and without PB stimulation. Whereas the n-6/n-3 ratio was varied while maintaining a constant P/S ratio (1.3), the PB-induced MFO activities were significantly elevated by decreasing the n-6/n-3 ratio although the MFO activities were not affected without PB stimulation. The MFO activities induced by PB were directly related to the n-3 PUFA content and inversely related to the n-6 PUFA content of the diets with n-6/n-3 ratios less than 4.55. These results obtained herein suggest that there are significant differences in the effects of n-6 and n-3 PUFAs on liver microsomal MFO activities, especially in relation to the induction of MFOs by PB.

Animals↗

PubMed1994

Liver microsomal mixed-function oxidases in response to dietary n-3 fatty acid levels in rats.

Phenobarbital (PB)-induced activities of the liver microsomal mixed-function oxidase (MFO) system in response to dietary levels of n-3 fatty acids were investigated in rats. The MFO activities were assessed by the contents of cytochromes P-450 and b5, and the activities of NADPH-cytochrome c reductase, aminopyrine N-demethylase and aniline hydroxylase. A linoleic acid (C18:2, n-6; LA) diet (2.0 energy % as LA) and n-3 fatty acid diets (0.3, 1.0, 1.9 or 4.8 energy % as n-3 fatty acids) were fed to rats for 16 days. The activities of MFOs except that of NADPH-cytochrome c reductase increased, as compared with the LA diet, with increasing the dietary n-3 fatty acid level, concomitant with the increase in n-3 fatty acids and decrease in n-6 fatty acids in liver microsomal lipids. The dietary LA over 1.8 energy % up to 13.8% did not increase the activities of PB-induced MFOs. Consequently, dietary n-3 fatty acids further elevated the PB-induced MFO activities effectively. These results suggest a differential response of dietary n-6 and n-3 fatty acids to the PB-induced MFO activities.

Aminopyrine N-Demethylase↗

PubMed1994

New cell line from hairy-cell leukaemia producing interleukin-6 after Epstein-Barr virus immortalization.

A hairy-cell leukaemia (HCL) cell line, HCL-O, was established from the peripheral blood of a 62-year-old Japanese patient with a unique variant of HCL strongly expressing CD21, the receptor for the Epstein-Barr virus (EBV). The HCL-O cells expressed antigens similar and dissimilar to those expressed with the original hairy cells. The HCL-O cells were more mature than the original cells in their degree of B-cell differentiation, as indicated by a decrease of CD19 and surface immunoglobulin (sIg) expression together with the appearance of CD38 and cytoplasmic Ig (cIg). In addition, the cells expressed CD11c recognized by Leu-M5, a monoclonal antibody usually positive for HCL. Their karyotype and Ig gene rearrangement pattern were identical to those of the original cells. The EBV genome was detected in the HCL-O cells but not in the original cells. The HCL-O cells spontaneously produced a large quantity of interleukin-6 (IL-6) in the conditioned medium, whereas IL-6 serum level was not so high. These findings indicate that the HCL-O cell line is derived from the leukaemic hairy cells and possibly, in vitro EBV infection took place easily in the original hairy cells through their CD21, resulting in subsequent immortalization. IL-6 production by HCL-O cells may be induced or enhanced by EBV, and the secreted IL-6 might play a role in their own growth or differentiation.

Cell Transformation, Viral↗

PubMed1994

Prophylaxis of symptoms of hyperhistaminemia after the treatment of acute promyelocytic leukemia with all-trans retinoic acid.

A 61-year-old man with acute promyelocytic leukemia (APL) is described in whom some leukemic promyelocytes contained granules similar to those of basophils, and hyperhistaminemia developed after treatment with all-trans retinoic acid. The symptoms of hyperhistaminemia, mediated via H2 receptors, were prevented by the administration of an H2-blocker, famotidine, but wheezing due to bronchospasms, mediated via H1 receptors, developed and was improved by administration of chlorpheniramine. In APL, it is generally thought that the maturation of neutrophilic leukocytes is arrested at the level of abnormal promyelocytes. However, heterogeneity of leukemic promyelocytes has been described and in a few patients some leukemic promyelocytes have been known to show basophilic features. Marked basophilia and severe symptoms due to hyperhistaminemia have recently been reported after the treatment of APL with all-trans retinoic acid. Our case presented similar basophilic features, but indicated that the symptoms of hyperhistaminemia after administration of retinoic acid can be prevented with antihistaminic drugs and suggested that both H1- and H2-blockers should be administered to such APL patients with basophilia.

Basophils↗

PubMed1994

Essential thrombocythemia terminating in acute leukemia with minimal myeloid differentiation--a brief review of recent literature.

Essential thrombocythemia (ET), one of the chronic myeloproliferative disorders, is a clonal disorder of multipotent stem cells. Although most patients with ET have a prolonged benign course, a minority of patients may develop a blastic crisis similar to chronic myelogenous leukemia (CML). A case of ET terminating in blastic crisis 8 years after the initial diagnosis is presented. The blast cells were cytochemically and immunophenotypically consistent with the acute myelogenous leukemia with minimal myeloid differentiation subtype of the FAB classification. From the review of the literature on blastic transformation of ET, acute leukemia with an M4 or M7 phenotype occurred more frequently. In addition, three valuable factors to predict the leukemic transformation of ET appear to be karyotypic abnormalities, such as involvement of chromosome 21, previous therapies with a mutagenic potential, and the capability of bone marrow cells to form in vitro spontaneous colonies as in CML.

Acute Disease↗

PubMed1994

Idiopathic pulmonary fibrosis. Epidemiologic approaches to occupational exposure.

Idiopathic pulmonary fibrosis (IPF) risk-related factors were epidemiologically investigated on the basis of 1,311 Japanese IPF autopsy cases selected from the annual complications of autopsy data records in Japan during a 12-yr period. Age and sex distribution of the subjects revealed a high peak in their seventh decade with males predominating. The IPF rate was more than two times higher (p < 0.01) among subjects engaged in occupations that exposed them to dust or organic solvents compared with those in other jobs. To ascertain job characteristics, an autopsy-case control study was conducted using other annual volumes of the autopsy data records and a similar tendency was observed. Then, a live-case control study was undertaken of 86 subjects with IPF. A significantly higher odds ratio was noted among metal production workers and miners compared with healthy and hospital control subjects (1.37 and 1.34, respectively, p < 0.01), and also a significantly lower odds ratio among subjects who frequently eat fish. Taken together with results of recent in vitro studies, the intrapulmonary deposition of hazardous dusts, especially metallic dusts, appears to play at least a partial role in initiating IPF.

Adolescent↗

PubMed1994

Calcein release from temperature-sensitive liposome with or without stirring.

Characteristics of the calcein release from temperature-sensitive liposomes with or without stirring were studied. Calcein release from DPPC(dipalmitoylphosphatidylcholine) REV(reverse phase evaporation vesicle) with stirring occurred at a temperature lower by 8 degrees than that without stirring. DPPC-DSPC(distearoylphosphatidylcholine)-mixed REV showed the maximum release(%) for calcein, near 40 degrees C with stirring and 45 degrees C without stirring.

1,2-Dipalmitoylphosphatidylcholine↗

PubMed1994

Stimulatory effect of beta-alanyl-L-histidinato zinc on alkaline phosphatase activity in bone tissues from elderly rats: comparison with zinc sulfate action.

The capability of beta-alanyl-L-histidinato zinc (AHZ) to increase alkaline phosphatase activity in the femoral diaphysis from elderly rats was investigated. The femoral-diaphyseal tissues were removed from weanling (3-week-old) and elderly (10-month-old) female rats. Bone tissues were cultured in Dulbecco's modified Eagle medium (high glucose, 4.5%) supplemented with antibiotics and bovine serum albumin. Among various other bone-stimulating factors (AHZ; 10(-5) M, zinc sulfate; 10(-4) M, sodium fluoride; 10(-3) M, insulin; 10(-8) M, and beta-estradiol; 10(-9) M), AHZ had a potent effect on increasing alkaline phosphatase activity in the diaphyseal tissues from both rat groups. In the bone tissues from elderly rats, the effect was concentration dependent (10(-7) - 10(-5) M). At 10(-5) M the effect of AHZ was seen for a longer time during 72-h culture, although the zinc sulfate (10(-5) M) effect was no longer. The effect of AHZ to increase bone alkaline phosphatase activity was completely abolished by the presence of cycloheximide (10(-6) M). AHZ thus appears able to directly stimulate alkaline phosphatase activity dependent on protein synthesis in the bone tissues from elderly rats.

Aging↗

PubMed1994

Comparison of the effect of beta-alanyl-L-histidinato zinc and its zinc-chelating ligand on bone metabolism in tissue culture.

The present investigation was undertaken to compare the effects of beta-alanyl-L-histidinato zinc (AHZ) and its zinc-chelating ligands on bone metabolism in tissue culture. Calvaria were removed from 3-week-old male rats and cultured for up to 72 h in Dulbecco's modified eagle medium containing zinc sulfate, AHZ, di(N-acetyl-beta-alanyl-L-histidinato)zinc (AAHZ), and di(histidino)zinc (HZ). The bone calcium content and alkaline phosphatase activity were significantly increased in the presence of AHZ or AAHZ (10(-8)-10(-5) M). Those increases were seen at 10(-7) to 10(-5) M zinc sulfate and HZ. The bone deoxyribonucleic acid (DNA) content was significantly increased by AHZ or AAHZ with 10(-7) to 10(-5) M, while 10(-7) M zinc sulfate and HZ had no effect. Thus, AHZ and AAHZ had more potent effect than that of zinc sulfate and HZ. The effect of AHZ, AAHZ and HZ (10(-5) M) increasing bone alkaline phosphatase activity was abolished by the presence of 10(-4) M dipicolinate, a chelator of zinc. Moreover, the effect of these zinc compounds on bone metabolic indices was not seen in the presence of 10(-6) M cycloheximide. The present results suggest that the effect of AHZ and AAHZ on bone metabolism is more potent than that of zinc sulfate and HZ.

Alkaline Phosphatase↗

PubMed1994

Histomorphological confirmation of the preventive effect of beta-alanyl-L-histidinato zinc on bone loss in ovariectomized rats.

The effect of beta-alanyl-L-histidinato zinc (AHZ), in which zinc is chelated to beta-alanyl-L-histidine, on bone loss was investigated in the femur of ovariectomized rats. AHZ (10, 30 and 100 mg/kg/d) was orally administered to ovariectomized rats for 3 months. Ovariectomy significantly decreased the estradiol concentration in the serum as compared with that from sham-operated rats. This decrease was not altered by the dose of AHZ. The bone ash weight and mineral density in the femur of ovariectomized rats significantly decreased in comparison with those from sham-operated rats. Moreover, the trabecular bone at the femoral metaphysis was clearly decreased by ovariectomy. The decreases in the femoral ash content and mineral density and the metaphyseal trabecular bone were clearly prevented by the tested doses of AHZ (10, 30 and 100 mg/kg/d). The present finding with histomorphological study further supports the view that the administration of AHZ can prevent bone loss by ovariectomy.

Administration, Oral↗

PubMed1994

Novel antiasthmatic agents with dual activities of thromboxane A2 synthetase inhibition and bronchodilation. III. 4-[2-(5-ethyl-2-thienyl)]-2'-[2-(1-imidazolyl)ethyl]-1(2H)- phthalazinones.

Synthesis and pharmacological evaluation of novel 4-[2-(5-ethyl-2-thienyl)]-2-[2-(1-imidazolyl)ethyl]-1(2H)-phthalazinone s are described. The phenyl moiety of the phthalazinone skeleton was found to play an important role in both thromboxane A2 synthetase-inhibitory and bronchodilatory activities.

Animals↗

PubMed1994

Novel antiasthmatic agents with dual activities of thromboxane A2 synthetase inhibition and bronchodilation. IV. 2-[2-(1-Imidazolyl)ethyl]-4-(3-pyridyl)-1(2H)-phthalazinones.

Synthesis and pharmacological evaluation of several compounds related to 2-[2-(1-imidazolyl)ethyl]-4-(3-pyridyl)-1(2H)-phthalazinones are described. The phenyl moiety of the phthalazinone skeleton was found to play an important role in both thromboxane A2 synthetase-inhibitory and bronchodilatory activities. Further, the 3-pyridyl group at the 4-position was shown to be necessary for in vivo thromboxane A2 synthetase-inhibitory activity.

Animals↗

PubMed1994

Pharmacological characterization of the novel anxiolytic beta-carboline abecarnil in rodents and primates.

beta-Carboline abecarnil was behaviorally and biochemically characterized as a new anxiolytic agent in rodents and primates in comparison with the benzodiazepine (BZ) anxiolytics. Oral treatment with abecarnil (0.5-10 mg/kg) showed a potent anticonflict activity in the water-lick test in rats. The minimal effective dose was lower than those of BZ anxiolytics, such as etizolam, diazepam, clotiazepam and tofisopam. Abecarnil also showed taming effects to suppress fighting and aggressive behaviors in mice and monkeys with little sedative and ataxic effects, in contrast to the BZ anxiolytics producing marked sedative and ataxic effects. Furthermore, abecarnil suppressed both the sedative and ataxic effects induced by diazepam. Abecarnil bound to rat cerebellar BZ1 receptors (Ki = 0.24 nM) with higher affinity than to rat spinal cord BZ2 receptors (Ki = 1.3 nM), whereas BZ derivatives bound to both the receptors with a low and equal affinity. GABA-ratios of abecarnil were 1.9 for the BZ1 receptors and 2.8 for the BZ2 receptors, and they were smaller than those of diazepam and flunitrazepam. Thus, in contrast to the BZ derivatives, abecarnil may act as a selective partial agonist at central BZ1 receptors, resulting in its potent anticonflict and taming effects with little sedative and ataxic effects.

Aggression↗