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Biomedical subjects

R Yoshimura

Publications and source records attributed to R Yoshimura.

At least 37 records · Page 2Linked to original sources
PubMed2002

Plasma levels of catecholamine metabolites predict the response to sulpiride or fluvoxamine in major depression.

We investigated the relationships between the changes in plasma catecholamine metabolites obtained from depressed patients before and after administration of sulpiride, a benzamide compound, or fluvoxamine, a selective serotonin reuptake inhibitor (SSRI), and between clinical responses to treatment with each of these drugs. Responders to sulpiride had significantly lower plasma homovanillic acid (pHVA) levels before administration of sulpiride than did non-responders or controls (responders: 4.5 +/- 3.1 ng/ml, non-responders: 11.1 +/- 5.9 ng/ml, controls: 10.9 +/- 5.3 ng/ml). Positive relationships were observed between changes in pHVA levels and improvement rates in the 17-item Hamilton Depression Rating Scale (Ham-D). In contrast, responders to fluvoxamine had significantly higher plasma free 3-methoxy-4-hydroxyphenylglycol (pMHPG) levels before administration of fluvoxamine than did non-responders or controls (responders: 8.5 +/- 1.8 ng/ml, non-responders: 5.9 +/- 2.I ng/ml, controls: 5.2 +/- 2.9 ng/ml). Negative relationships were observed between changes in pMHPG levels and improvement rates in Ham-D. These results suggest that lower pretreatment pHVA levels and higher pretreatment levels of pMHPG might be predictors of response to sulpiride and fluvoxamine, respectively, and that sulpiride might produce a functional increase in the dopaminergic system, resulting in improvement in some depressive symptoms; fluvoxamine, on the other hand, might produce a functional decrease in the noradrenergic system via serotonergic neurons, resulting in improvement of those symptoms.

Adult↗
PubMed2001

Characteristics of fluvoxamine-induced nausea.

We investigated the association between fluvoxamine and nausea from various viewpoints. The incidence of nausea induced by fluvoxamine was 29% (12/41). Plasma 5-hydroxyindoleacetic acid (p5-HIAA) levels after fluvoxamine administration were significantly higher in patients with nausea (6.6+/-3.4 ng/ml) than in those without nausea (3.5+/-2.7 ng/ml). On the other hand, no significant differences were found between patients with and patients without nausea in terms of sex, age, initial and maximum dosages of fluvoxamine and its plasma concentrations, and clinical response to fluvoxamine. However, the incidence of nausea in patients who were initially administered fluvoxamine at under 50 mg/day was significantly lower than in those who were started at above 50 mg/day. In addition, mosapride, a member of the benzamide family, was effective in alleviating fluvoxamine-induced nausea. These results suggest that fluvoxamine-induced nausea is associated with hyperactivity in serotonergic neurons.

Adult↗
PubMed2001

Expression of peroxisome proliferator-activated receptor gamma in renal cell carcinoma and growth inhibition by its agonists.

Peroxisome proliferator-activated receptor-gamma (PPAR-gamma) is a ligand-activated transcriptional factor belonging to the steroid receptor superfamily. It plays a role in both adipocyte differentiation and tumorgenesis. Up-date, the up-regulation of PPAR-gamma expression is a frequent occurrence in a variety of different malignant tumors. In this study, we investigated the expression of PPAR-gamma in human renal cell carcinoma (RCC) tissues, and the role of PPAR-gamma in cell growth in human RCC-derived cell lines. Immunohistochemistry showed a strong immunoreactive expression of PPAR-gamma in all slides from cancer specimens. RT-PCR and Western blot analysis showed 3 RCC cell lines expressed PPAR-gamma mRNA and its protein. MTT assay in 3 RCC cells showed that the synthetic PPAR-gamma agonists thiazolidinedione compounds (pioglitazone and troglitazone) and the endogeneous PPAR-gamma ligand, 15-deoxy-Delta12,14-prostaglandin J(2) (15dPGJ(2)) inhibited the growth of the RCC cells. These results suggest that PPAR-gamma may become a new target in the treatment of RCC.

Antineoplastic Agents↗
PubMed2001

Relationship between bone marrow cellularity and apparent diffusion coefficient.

This study was performed to determine if there is a relationship between apparent diffusion coefficient (ADC) and cellularity of bone marrow of the posterior ilium. Four groups of various marrow cellularity underwent diffusion-weighted echo-planar imaging: 1) adults with normal hypocellularity (21 patients); 2) adults with normal normocellularity (13 patients); 3) young children with normal hypercellularity (5 patients); and 4) adults with lymphoma-related hypercellularity (3 patients). In all adults, marrow cellularity was confirmed by uni-or bilateral bone marrow biopsies. In children, the iliac marrow was presumed hypercellular because of their ages. A total of 66 ADC values of bone marrow calculated from diffusion-weighted images with b-values of 30 and 300 seconds/mm(2) was evaluated. Hypercellular marrow (normal and lymphoma-related) showed the highest mean ADC, and hypocellular the lowest ADC. Statistically significant differences were found between three groups of normal marrow: hypocellular, normocellular, and hypercellular. There is a positive correlation between ADC and cellularity of bone marrow. J. Magn. Reson. Imaging 2001;13:757-760.

Adult↗
PubMed2001

Functional evaluation with intravoxel incoherent motion echo-planar MRI in irradiated salivary glands: a correlative study with salivary gland scintigraphy.

The purpose of this study was to determine the relationship between the apparent diffusion coefficient (ADC) measured on intravoxel incoherent motion (IVIM) echo-planar magnetic resonance imaging (MRI) and salivary gland function. Twenty-one patients with head and neck malignancies underwent MRI and salivary gland scintigraphy before and after radiotherapy. Based on the scintigraphic results, each major salivary gland was classified into two groups (dysfunctional and functional) and ADCs measured on IVIM MRI were compared between the two groups. Furthermore, the relationship of ADC to scintigraphic parameters, maximum accumulation (MA), and the uptake ratio (UR), were analyzed. ADCs of the dysfunctional group decreased significantly after radiotherapy (P <.01), whereas those of the functional group showed no significant change. Furthermore, positive correlations were found between the ADC ratio and both MA (P <.005) and UR (P <.001). ADC measurement on IVIM echo-planar MRI is a potentially useful means of evaluating salivary gland function.

Adult↗
PubMed2001

Increased libido in a woman treated with fluvoxamine: a case report.

OBJECTIVE: The aim of this paper is to describe a case of increased libido during fluvoxamine therapy. METHOD: Single case report. RESULTS: The patient, a 27-year-old married Japanese woman with borderline personality disorder, developed an increased libido with the administration of fluvoxamine. The increased libido disappeared after fluvoxamine was discontinued. CONCLUSION: The present findings suggest that fluvoxamine can cause increased libido in some patients.

Adult↗
PubMed2001

Effect of clonazepam treatment on antipsychotic drug-induced Meige syndrome and changes in plasma levels of GABA, HVA, and MHPG during treatment.

We demonstrated the effect of clonazepam (2 mg/day) on Meige syndrome in two schizophrenic patients under continuous treatment with antipsychotic drugs, and changes in the plasma levels of gamma-aminobutyric acid (GABA), homovanillic acid (HVA), and 3-methoxy-4-hydroxyphenylglycol (MHPG) in these cases. The plasma levels of HVA and MHPG during treatment with clonazepam were decreased in the responder, while not changed in the non-responder to clonazepam. A difference between the responder and the non-responder was not found in the plasma GABA levels. These results suggest that hyperactivities of the central dopaminergic and noradrenergic neurones are involved in the pathophysiology of Meige syndrome.

Adult↗
PubMed2001

Are tobacco use and urine pH indicated as risk factors for bladder carcinoma?

BACKGROUND: Many case-control and cohort studies have shown a positive relationship between bladder carcinoma and tobacco use. Recently, urine pH has been reported to influence aromatic amine carcinogenesis, which have been implicated as potent carcinogens in bladder carcinoma patients. Herein the correlation between bladder carcinoma, tobacco use and urine pH is reported. METHOD: One hundred and forty-one patients with bladder carcinoma and 128 patients with benign prostatic hyperplasia or urolithiasis as controls were selected. All patients were admitted to Osaka City University Hospital for the purpose of surgical treatment. Urine pH was checked by a test tape. RESULTS: Of the patients with bladder carcinoma, 106 were smokers and 35 were non-smokers. In contrast, the number of smokers in the control group was 76 and that of non-smokers was 52. The odds ratio in the bladder carcinoma group calculated for the smoker patients was 2.07, showing a significant correlation between bladder carcinoma and tobacco use. Regarding urine pH, acidic urine was found in 126 patients in the bladder carcinoma group and in 116 patients in the control group. The odds ratio in the bladder carcinoma group for acidic urine was 0.87, showing no significant relationship between bladder carcinoma and urine pH. CONCLUSION: The study found a positive relationship between bladder carcinoma and tobacco use; however, it could not establish a clear relationship between bladder carcinoma and urine pH, even in the smoker group.

Aged↗
PubMed2001

Dual phases of functional change in norepinephrine transporter in cultured bovine adrenal medullary cells by long-term treatment with clozapine.

The effects of long-term treatment with clozapine, a prototype of atypical antipsychotic drugs, on the functional activity, synthesis and mRNA of norepinephrine (NE) transporter were examined in bovine adrenal medullary cells in culture. Treatment of cells with clozapine at 0.1-3.0 microM concentrations produced dual phases of changes in [(3)H]NE uptake, i.e. the first phase showed a decrease in [(3)H]NE uptake at 2-48 h, and the following phase showed an increase in uptake at 72-168 h. Treatment with clozapine for 6 h decreased V(max) to 40% of the control without changing the K(m) value for [(3)H]NE uptake. However, treatment with clozapine for 96 h increased V(max) by 56% over the control without a change in K(m). Scatchard plot analysis of [(3)H]desipramine (DMI) binding to membranes isolated from cells treated with clozapine for 6 h revealed a decrease in B(max) without any change in K(d); in contrast, treatment with clozapine for 96 h caused an increase in B(max) without any change in K(d). Both actinomycin D and cycloheximide, which are inhibitors of protein synthesis, suppressed the clozapine (96 h)-induced increase in [(3)H]NE uptake. Treatment of cells with clozapine for 12-96 h increased the level of NE transporter mRNA in a concentration-dependent manner (0.3-3.0 microM). These findings suggest that treatment of cells with clozapine results in the down-regulation and subsequent up-regulation of NE transporter. The latter change may be caused by the synthesis of new proteins of NE transporter via an increase in its mRNA.

Adrenal Medulla↗
PubMed2001

Primary retroperitoneal pure yolk-sac tumor in an adult male.

Pure extragonadal tumors are rare in adult males. A 24-year-old male with an extremely high level of serum alpha-fetoprotein (32.795 ng/ml) was diagnosed by abdominal computed tomography as having a retroperitoneal tumor. A case of primary retroperitoneal pure yolk-sac tumor in an adult male is described.

Adult↗
PubMed2001

Association of plasma free-3-methoxy-4-hydroxyphenyl (ethylene)glycol, natural killer cell activity and delirium in postoperative patients.

We measured and compared levels of plasma free 3-methoxy-4-hydroxyphenyl (ethylene)glycol (pMHPG), a major metabolite of noradrenaline, and natural killer (NK) cell activity in 26 patients prior to their undergoing an operation for cardiovascular diseases; 11 of whom expressed delirium and 15 who did not. In conclusion, we found that pMHPG levels before an operation were higher in patients with postoperative delirium than in the patients without, while NK cell activity showed no difference between the two groups. It is possible that hyperactivity of noradrenargic neurons is connected with the development of postoperative delirium. Furthermore, we considered that measurement of pMHPG level before operation might be a useful tool to predict the occurrence of postoperative delirium.

Aged↗