Biomedical subjects

Yasushi Yoshida

Publications and source records attributed to Yasushi Yoshida.

At least 19 recordsLinked to original sources

PubMed2007

[Locally advanced breast cancer with a good response to sequential endocrine monotherapy--a case report].

An 81-year-old woman with a right breast tumor exposed through the skin surface visited our clinic in June 2004. Pathological findings of the resected tumor specimen indicated invasive ductal carcinoma of the breast,positive ER/PgR status,and negative HER 2/neu status. The enlarged right axillary lymph nodes were palpable. Ultrasonography and computed tomography revealed that the tumor invaded the chest wall without any metastasis to remote organs. On July 5, 2004, we started anastrozole treatment. Its effects were confirmed in the first month,and the treatment was continued for 8 months. Substituting anastrozole with exemestane was not effective. However, the exposed part of the tumor completely responded to tamoxifen that was administered for 2 months. The effect of tamoxifen continued until February 2006, and most of the subcutaneous part of the tumor became nonpalpable. Thus, sequential endocrine monotherapy proved useful for an elderly woman with locally advanced breast cancer.

Aged, 80 and over↗

PubMed2006

Sex difference in body weight gain and leptin signaling in hypocretin/orexin deficient mouse models.

Recent studies in human and animal models of narcolepsy have suggested that obesity in narcolepsy may be due to deficiency of hypocretin signaling, and is also under the influence of environmental factors and the genetic background. In the current study, using two hypocretin/orexin deficient narcoleptic mouse models (i.e. preproorexin knockout (KO) and orexin/ataxin-3 transgenic (TG) mice) with cross-sectional assessments, we have further analyzed factors affecting obesity. We found that both KO and TG narcoleptic mice with mixed genetic backgrounds (N4-5, 93.75-96.88% genetic composition of C57BL/6) tended to be heavier than wild type (WT) mice of 100-200 days old. The body weight of heterozygous mice was intermediate between those of KO and WT mice. Obesity was more prominent in females in both KO and TG narcoleptic mice and was associated with higher serum leptin levels, suggesting a partial leptin resistance. Obesity is less prominent in the congenic TG narcoleptic mice, but is still evident in females. Our results confirmed that hypocretin/orexin ligand deficiency is one of the critical factors for the obese tendency in narcolepsy. However, multiple factors are also likely to affect this phenotype, and a sex difference specific alteration of leptin-hypocretin signaling may be involved.

Animals↗

PubMed2006

Expression pattern of FOS in orexin neurons during sleep induced by an adenosine A2A receptor agonist.

The present study examined the expression pattern of FOS in the hypothalamic peptide neurons during the sleep-dominant state induced by an adenosine A2A receptor agonist. The control rats, those that received the microdialysis-perfusion of their ventral striatum with artificial cerebrospinal fluid in the dark-active phase, spent 24% of the 90-min period prior to sacrifice in non-rapid eye movement (non-REM) sleep and 2.3% of that in REM sleep. These rats exhibited FOS, a transcription factor, in 21% of their orexin neurons and in 1.0% of their melanin-concentrating hormone (MCH) neurons in the perifornical/lateral hypothalamic areas. However, the rats perfused with 50 microM CGS21680, an adenosine A2A receptor agonist, spent 60% of the 90-min period prior to sacrifice in non-REM sleep and 11% of that in REM sleep. These rats exhibited FOS in 1.7% of their orexin neurons and FOS in 0.5% of their MCH neurons. When the sleep-dominant state was disturbed by mild stimulation and the rats were kept in the sleepy state by treatment with a sleep-inducing dose of CGS21680, the rats exhibited FOS in 13.3% of their orexin neurons, which percentage was about half of that for the control rats. These results suggest that the sleep-promoting process induced by this adenosine A2A receptor agonist was associated with a decline in the activity of orexin neurons. MCH neurons are not likely to change their activities during this sleep-promoting process.

Adenosine↗

PubMed2006

An activation of parvocellular oxytocinergic neurons in the paraventricular nucleus in oxytocin-induced yawning and penile erection.

Intracerebroventricular (ICV) or PVN local injections of oxytocin induce yawning and penile erection, for which a positive feedback mechanism for the PVN oxytocinergic activation is suggested, but this had not been directly substantiated in vivo. We have assessed the behavioral effects and activity of oxytocinergic neurons with double-staining for c-Fos and oxytocin in the PVN after ICV administration of oxytocin in adult male rats. ICV oxytocin injections (50 and 200 ng) dose-dependently induced yawning and penile erection and significantly increased the percentage of c-Fos positive oxytocin neurons in the medial, dorsal and lateral parvocellular subdivision of the PVN. However, increases in the magnocellular portion were not significant. We also found that lithium chloride (LiCl, 0.5 and l.0 mEq), a compound known to activate oxytocinergic neurons, also significantly increased the percentage of c-Fos positive oxytocin neurons in all PVN portions. However, LiCl did not induce yawning and penile erection, but counteracted the oxytocin-induced yawning and penile erection. These results suggest that if the activation of oxytocinergic neurons in the PVN is important for mediating oxytocin-induced yawning and penile erection, a selective activation of parvocellular oxytocinergic neurons in the PVN is likely to be involved.

Animals↗

PubMed2006

Joint symptoms: a practical problem of anastrozole.

BACKGROUND: Anastrozole and tamoxifen have mild toxicity. However, we noticed that more patients treated with anastrozole complained of joint symptoms than expected. In particular, digital stiffness as is seen with rheumatoid arthritis is a problem. Some clinical trials of anastrozole in Europe and the United States reported musculoskeletal disorders as adverse events, however, joint symptoms were not described in detail. PATIENTS AND METHODS: At our clinic from August 2001 to March 2005, 53 postmenopausal women with estrogen receptor-positive breast cancer were treated with anastrozole. We calculated the incidence and classified the grade of joint symptoms by interviewing patients. We also investigated the patients' characteristics and their relevance to joint symptoms. RESULTS: Of 53 patients, 14 patients (26%) had joint symptoms (13 patients with digital stiffness and 3 patients with arthralgias of wrist and shoulders). Joint symptoms tended to occur in the patients who had previously undergone chemotherapy; however, there has no relationship between prior hormonal therapy and joint symptoms. Seven patients who discontinued anastrozole treatment showed improved symptoms. Five patients with grade 1 digital stiffness continued anastrozole treatment without additional treatment. Two patients with grade 1 digital stiffness, who took a Chinese herbal medicine showed improved symptoms and continued anastrozole treatment. CONCLUSION: Benefits to the patients may possibly be lost by discontinuation of anastrozole or changing to tamoxifen since the clinical superiority of anastrozole to tamoxifen has been reported. We should continue anastrozole in patients with low grade symptoms, while ensuring that patients are aware of the toxicity of anastrozole.

Adult↗

PubMed2006

[Two cases of stage IV breast cancer with severe hypercalcemia].

Case 1: A 34-year-old woman,who had a right breast cancer with axillary lymph node metastasis and multiple bone metastases, was referred to our clinic. She developed paralysis of lower extremities and disorder of the bladder and rectum due to metastasis to the thoracic vertebra, and also had renal dysfunction due to severe hypercalcemia and hemorrhagic cystitis. Correcting the serum calcium level with intravenous infusion, elcatonin, pamidronate and betamethasone, she underwent radiation therapy for the vertebral metastasis. The first hormonal therapy (leuprorelin/exemestane) had been effective for about 4 months, however the second hormonal therapy (leuprorelin/tamoxifen) was not effective. Chemotherapy with paclitaxel (80 mg/m(2), day 1, 8, 15, every 4 weeks) brought about a stable general condition and a normal level of serum calcium with zoledronate in the ninth month of treatment. Case 2: A 32-year-old woman, who had a right breast cancer with multiple bone metastases and axillary and hilar lymph node metastases, came to our clinic, complaining of nausea due to severe hypercalcemia. After successful correction of hypercalcemia by the intravenous infusion and administration of elcatonin, pamidronate and dexamethasone, the hormonal therapy(goserelin/tamoxifen) caused rapid re-elevation of serum calcium and tumor marker, so that a tumor flare was suspected. After 3 cycles of EC therapy (EPI 90 mg/m(2), CPM 600 mg/m(2), every 3 weeks), 2 cycles of paclitaxel therapy (80 mg/m(2), day 1, 8, 15, every 4 weeks) brought about tumor reduction and the normal level of serum calcium. After 7 cycles of paclitaxel therapy,the hormonal therapy (goserelin/tamoxifen) proved effective for several months. To achieve tumor reduction and stabilize the serum calcium level, we need to start immediately the treatment of breast cancer with severe hypercalcemia, considering the general condition of the patient.

Adult↗

PubMed2006

[A case of recurrent GIST successfully treated with low-dose imatinib mesilate].

A 75-year-old man underwent partial resection of the small intestine for GIST in January 2000. A recurrent tumor revealed in the intra pelvic space was removed by two operations, and imatinib (400 mg/day) was given after the third operation. As successive administration was not able to be continued due to side effects such as anorexia and fatigue, the recurrent tumor enlarged. After imatinib was given at 200 mg/day, the defecation trouble was improved and the tumor decreased partially on CT image. His partial response has continued over one year. Mutation analysis revealed deletion and point mutation in exon 11 of c-kit gene. Low-dose imatinib administration should be considered in case of side effects at the standard dose.

Aged↗

PubMed2006

[Two cases of recurrent breast cancer with regional lymph node metastases showing a complete response to trastuzumab and paclitaxel treatment].

We report two cases of recurrent breast cancer with regional lymph node metastases that responded completely to treatment with trastuzumab and paclitaxel. Case 1: A 52-year-old woman, who presented with left breast cancer, underwent mastectomy and axillary lymph node dissection in July 2002. Pathological findings were as follows: invasive ductal carcinoma (scirrhous type), 2.2 cm in size, histological grade 3, positive invasion to the lymphatic and blood vessels, negative nodal status (0/11), negative ER/PgR status, and overexpression of HER 2/neu. Left axillary lymph node metastasis was noted after five months, ie, in December 2002. Four cycles of chemotherapy with doxorubicin and cyclophosphamide were administered from January 2003; however, they were not effective. The patient showed a complete response after three months of chemotherapy with trastuzumab and paclitaxel. This treatment was stopped in September 2003. She has maintained a complete response for two and a half years and was not administered any further treatment as of February 2006. Case 2: A 59-year-old woman, who presented with right breast cancer, underwent mastectomy and axillary lymph node dissection in May 2002. Pathological findings were as follows: invasive ductal carcinoma (scirrhous type), 1.8 cm in size, histological grade 2, positive invasion to the lymphatic and blood vessels, negative nodal status (0/5), positive ER and uncertain PgR status, and overexpression of HER 2/neu. She had received adjuvant hormonal therapy with tamoxifen; however, a right supraclavicular lymph node metastasis was noted in October 2004. Treatment with exemestane was not effective. However, a complete response was observed with trastuzumab and paclitaxel for four months. She has maintained a complete response for six months and was not administered any further treatment as of February 2006.

Antibodies, Monoclonal↗

PubMed2005

Effects of fexofenadine hydrochloride in a guinea pig model of antigen-induced rhinitis.

Allergic rhinitis is an inflammatory disease of the nasal mucosa, induced by histamine, leukotrienes, and other substances released from mast cells. Fexofenadine hydrochloride, the active metabolite of terfenadine, is a novel, nonsedating antiallergic drug having H1 receptor antagonistic activity. Fexofenadine is effective for the treatment of allergic rhinitis. However, its mechanism of action in attenuating nasal congestion has not yet been elucidated. Therefore, we first examined the effects of fexofenadine on a guinea pig model of antigen-induced rhinitis. We also evaluated the effects of mepyramine, zafirlukast and ramatroban in this model; these drugs are an H1 receptor antagonist, a selective leukotriene antagonist and a selective thromboxane antagonist, respectively. Rhinitis was induced by ovalbumin (OVA) instillation into the nasal cavity of animals that had been sensitized by two earlier OVA injections (s.c. and i.p.). The nasal airway resistance was measured for 45 min after the challenge. Fexofenadine hydrochloride (20 mg/kg) and terfenadine (20 mg/kg) administered orally 70 min prior to the challenge significantly inhibited (fexofenadine, p < 0.001, terfenadine, p < 0.05) the increase in nasal airway resistance. Ramatroban (30 mg/kg) administered orally 60 min prior to the challenge also significantly inhibited (p < 0.05) the increase in nasal airway resistance. In contrast, mepyramine (3 mg/kg i.v.) and zafirlukast (3 mg/kg p.o.) failed to reduce the increase in nasal airway resistance. These results suggest that thromboxane may be involved in the increase in the nasal airway resistance in this model. Accordingly, fexofenadine may reduce the increase in nasal airway resistance by inhibiting the release of chemical mediators, including thromboxane, that are involved in the increase in nasal airway resistance in this model.

Airway Resistance↗

PubMed2005

Population study of Y-chromosome STR haplotypes in Japanese from the Tokushima.

The Y-chromosome short tandem repeat (STR) systems including DYS19, DYS389I/II, DYS390, DYS391, DYS392, DYS393, DYS385 and YCAII were investigated in 121 Japanese males (Tokushima area). Analysis of the nine loci permitted classification of the samples into 107 haplotypes, and the haplotype diversity was estimated to be 0.989. DYS385 showed the highest gene diversity (GD) value (GD=0.946), while DYS391 showed the lowest GD value (GD=0.27). Furthermore, in DYS392, we found a new mutant allele that added a T within the repeat region (a mutation in the repetitive region), and the allele was designated 13.1 according to the sequence structure. We also detected allele 20 in DYS392 as a new allele. In DYS385, a new allele 26 that has not been previously reported was observed.

Asian People↗

PubMed2005

[The relationship between idea search space and creativity].

This study investigated the relationship between participants' evaluation of creativiy and characteristics of creative products towards a clear and objective definition of the concept of creativity. Three experiments examined whether the size of "idea search space" in the creative process predicts the score of products in creativity assessments. In Experiment 1, in order to construct an multidimensional scaling (MDS) space which was supposed to correspond to creators' "idea space," 20 participants exhaustively evaluated the strength of semantic connection between every pair of 50 (physical) parts of possible creatures. In Experiment 2, 40 participants drew novel extraterrestrial creatures using five out of 50 parts used in Experiment 1. In Experiment 3, 20 participants assessed the creativity of each of the 40 drawings from Experiment 2. The results showed that a drawing with a larger idea search space estimated by the MDS score have a tendency to receive a higher creativity score. These results support the framework of idea search space and a possibility of explaining the creativity in terms of this model is suggested.

Adult↗

PubMed2004

Lesions of the suprachiasmatic nucleus eliminate the daily rhythm of hypocretin-1 release.

STUDY OBJECTIVES: Hypocretins (orexins) are involved in the sleep disorder narcolepsy. While hypocretin-1 has a daily oscillation, little is known regarding the relative contribution of circadian and homeostatic components on hypocretin release. The effect of lesions of the suprachiasmatic nucleus (SCN) on hypocretin-1 in the cerebrospinal fluid (CSF) was examined. DESIGN: SCN-ablated (SCNx) and sham-operated control rats were implanted with activity-temperature transmitters. Animals were housed individually under 1 of 3 lighting conditions: 12-hour:12-hour light:dark cycle (LD), constant light (LL), and constant darkness (DD). Lesions were verified histologically and shown not to affect hypocretin-containing cells. Hypocretin-1 concentrations in the CSF were determined every 4 hours using radioimmunoassays. MEASUREMENTS AND RESULTS: Control animals displayed robust circadian (LL, DD) and diurnal (LD) fluctuations in CSF hypocretin-1, locomotor activity, and temperature. Peak CSF hypocretin-1 was at the end of the active period. Activity, temperature, and CSF hypocretin-1 were arrhythmic in SCNx animals in LL and DD. In LD, a weak but significant fluctuation in activity and temperature but not CSF hypocretin-1 was observed in SCNx animals. We also explored correlations between CSF hypocretin-1, CSF corticosterone, and locomotor activity occurring prior to CSF sampling in arrhythmic SCNx rats under constant conditions. Significant correlations between hypocretin-1 and activity were observed both across and within animals, suggesting that interindividual and time-of-the-day differences in activity have significant effects on hypocretin release in arrhythmic animals. No correlation was found between CSF hypocretin-1 and corticosterone. CONCLUSIONS: Hypocretin-1 release is under SCN control. Locomotor activity influences the activity of the hypocretin neurons.

Animals↗

PubMed2004

Narcolepsy caused by acute disseminated encephalomyelitis.

BACKGROUND: Narcolepsy with cataplexy is caused by a selective loss of hypocretin-producing neurons, but narcolepsy can also result from hypothalamic and rostral brainstem lesions. PATIENT: We describe a 38-year-old woman with severe daytime sleepiness, internuclear ophthalmoplegia, and bilateral delayed visual evoked potentials. Her multiple sleep latency test results demonstrated short sleep latencies and 4 sleep-onset rapid eye movement sleep periods, and her cerebrospinal fluid contained a low concentration of hypocretin. Magnetic resonance imaging showed T2 and fluid-attenuated inversion recovery hyperintensity along the walls of the third ventricle and aqueduct, which are consistent with acute disseminated encephalomyelitis. RESULTS: After treatment with steroids, this patient's subjective sleepiness, hypersomnia, and hypocretin deficiency partially improved. CONCLUSIONS: Autoimmune diseases such as acute disseminated encephalomyelitis can produce narcolepsy. Most likely, this narcolepsy is a consequence of demyelination and dysfunction of hypocretin pathways, but direct injury to the hypocretin neurons may also occur.

Adult↗

PubMed2004

The active metabolite of leflunomide, A771726, inhibits both the generation of and the bone-resorbing activity of osteoclasts by acting directly on cells of the osteoclast lineage.

Leflunomide is a disease-modifying antirheumatic drug that inhibits paw swelling and joint destruction in type II collagen-induced arthritis in mice and it also delays disease progression in patients with rheumatoid arthritis (RA), through inhibiting proliferation and cytokine production of T cells, via the blocking of de-novo pyrimidine biosynthesis by its active metabolite, A771726. However, the direct action of leflunomide on cells of osteoclast lineage responsible for bone destruction in RA remains to be clarified. In this study, we examined the effect of A771726 on osteoclast formation and bone-resorbing activity in vitro, using cultures of bone marrow-derived osteoclast progenitors and purified functionally mature osteoclasts, and then we elucidated the molecular mechanism of action of the effect of A771726 on osteoclasts. A771726 inhibited osteoclast formation from macrophage colony-stimulating factor (M-CSF)-dependent osteoclast progenitors in the presence of receptor activator of nuclear factor kappa B (NF-kappaB) ligand (RANKL), without any other types of cells present, in a dose-related manner, similar to the inhibition in cultures of unfractionated bone marrow cells. In addition, A771726 suppressed bone resorption by isolated mature osteoclasts. These results indicate that A771726 directly and intrinsically inhibited the differentiation and function of osteoclast lineage cells without any mediation by other cells. The inhibition by A771726 was not restored by the simultaneous addition of uridine, and may be independent of the blockade of NF-kappaB activation and the tyrosine phosphorylation of proteins. Thus, leflunomide, through its active metabolite, has the potential to prevent bone loss by directly inhibiting osteoclastogenesis and osteoclast function. This inhibition suggests a novel mechanism for leflunomide in the retardation of the joint destruction observed in RA patients.

Aniline Compounds↗

PubMed2004

The roles of midbrain and diencephalic dopamine cell groups in the regulation of cataplexy in narcoleptic Dobermans.

Cataplexy, an emotion-triggered sudden loss of muscle tone specific to narcolepsy, is tightly associated with hypocretin deficiency. Using hypocretin receptor 2 gene (hcrtr 2)-mutated narcoleptic Dobermans, we have previously demonstrated that altered dopamine (DA) D(2/3) receptor mechanisms in mesencephalic DA nuclei are important for the induction of cataplexy. In the current study, we also found that the administration of D(2/3) agonists into diencephalic dopaminergic cell groups, including the area dorsal to the ventral tegmental area (DRVTA) and the periventricular gray (PVG) matter of the caudal thalamus (corresponding to area A11), significantly aggravated cataplexy in hcrtr 2-mutated narcoleptic Dobermans. A D(1) agonist and antagonist and a DA uptake inhibitor perfused into the DRVTA had no effect on cataplexy, suggesting an involvement of D(2/3) receptors located on DA cell bodies (i.e., autoreceptors) for the regulation of cataplexy. Because the A11 cell group projects to the spinal ventral horn, the A11 D(2/3) receptive mechanisms may directly modulate the activity of spinal motoneurons and modulate cataplexy.

Animals↗

PubMed2004

Forensic casework of personal identification using a mixture of body fluids from more than one person by Y-STRs analysis.

We applied Y-STRs (DYS385/DYS19/YCAII) to an adhesive plaster left at a crime scene. This plaster may have included body fluids from more than one person. Firstly, we performed preliminary examinations, ABO-blood type examinations, and commonly used DNA examinations (D1S80, HLADQalpha, TH01, and PM) on these specimens. As a result of these examinations, we could evidence that suspect A did not contacted with the plaster, but could not confirm the presence of perspiration from suspect B. As the next step, we applied Y-STR examination to the plaster. Using this examination, we detected alleles that coincided to those of suspect B. We also concluded that the fluid from an unidentified person was vaginal fluid based on crime scene investigation. Y-STRs examination data obtained from 124 persons in Tokushima prefecture showed that 1.613% of individuals demonstrated haplotypes 10-18/15/19-23, which was detected from the plaster and from suspect B. Therefore, we considered that there was a high probability that the persiration detected in the plaster was that of suspect B. Based on these studies, we concluded that Y-STR examination of trace evidence was very useful to screen suspects using materials that contained body fluid from more than one person.

ABO Blood-Group System↗

PubMed2004

Application of AmpFISTR Profiler PCR Amplification kit for personal identification of a putrefied cadaver.

A putrefied cadaver of a middle-aged woman was found drifting in the 'Kii" water course. Autopsy findings indicated that the postmortem duration was about one week, and the cause of death was assumed to be drowning. In this case, a nail was collected as a sample for personal identification. After five months of police investigation, persons thought to be her family, husband and child, were found. A combination of D1S80 and the short tandem repeat (STR) typing system using an AmpFISTR Profiler PCR Amplification kit was performed for identification. Nine STRs (D3S1358, vWA, FGA, TH01, TPOX, CSF1PO, D5S818, D13S317 and D7S820) and Amelogenin were analyzed by this kit. Those DNA typings successfully confirmed the family relation for personal identification of the cadaver. This analysis system may be useful for identification of a decomposed cadaver.

ABO Blood-Group System↗

PubMed2003

Effects of IV and ICV hypocretin-1 (orexin A) in hypocretin receptor-2 gene mutated narcoleptic dogs and IV hypocretin-1 replacement therapy in a hypocretin-ligand-deficient narcoleptic dog.

STUDY OBJECTIVES: Using two different canine models of narcolepsy, we evaluated the therapeutic effects of hypocretin-1 on cataplexy and sleep. MEASUREMENTS AND RESULTS: Intracerebroventricular administration of hypocretin-1 (10 and 30 nmol per dog) but not intravenous administration (up to 6 microg/kg) induced significant wakefulness in control dogs. However, hypocretin-1 had no effect on cataplexy or wakefulness in hypocretin receptor-2 gene (Hcrtr2) mutated narcoleptic Dobermans. Only very high intravenously doses of hypocretin-1 (96-384 microg/kg) penetrated the brain, to produce a short-lasting anticataplectic effect in a hypocretin-ligand-deficient animal. CONCLUSIONS: Hypocretin-1 administration, by central and systemic routes, does not improve narcoleptic symptoms in Hcrtr2 mutated Dobermans. Systemic hypocretin-1 hardly crosses the blood-brain barrier to produce therapeutic effects. The development of more centrally penetrable and longer lasting hypocretin analogs will be needed to further explore this therapeutic pathway in humans.

Animals↗