Search PubMed⌕ Search

Biomedical subjects

H Yamada

Publications and source records attributed to H Yamada.

At least 73 records · Page 4Linked to original sources
PubMed2003

Antagonistic effects of intravenous or epidural atipamezole on xylazine-induced dorsolumbar epidural analgesia in cattle.

This study was performed to clarify the antagonistic actions of intravenous or epidural atipamezole on the sedative and analgesic effects of xylazine administered between the epidural fat and dura mater through the first interlumbar space in cattle. Cattle received 5 mL of a solution containing 0.05 mg x kg(-1) xylazine in 0.9% saline. Thirty minutes later, 5 mL of 0.9% saline was administered through the same needle (treatment 1) (XSE). In treatments 2 (XAE) and 3 (XAV), 5 mL of a solution containing 0.025 mg x kg(-1) atipamezole in 0.9% saline was administered epidurally or intravenously, respectively. Sedation and analgesia were similar in all three treatment groups and could be reversed by atipamezole given by either route. In the XAV treatment, the flank area relapsed into analgesia 25+/-5.8 min following reversal of the analgesic effect, and was maintained for 112.5+/-63.8 min. The present study confirmed that the sedative and analgesic effects of xylazine are completely reversed by atipamezole and can be influenced by the epidural fat in cattle. Furthermore, it seems probable that analgesia following epidural administration of xylazine is mediated by alpha(2)-adrenergic receptors, not by a local anaesthetic effect.

Adipose Tissue↗
PubMed2003

Effect of the neurotoxic dose of methamphetamine on gene expression of parkin and Pael-receptors in rat striatum.

We previously reported that haloperidol, a dopamine-D(2) receptor antagonist, induced striatal expression of parkin gene, which mutations cause autosomal recessive juvenile parkinsonism. Because of an involvement of the parkin gene defect in selective degeneration of dopaminergic neurons, we herein examined the effect of the neurotoxic dose of methamphetamine (METH; 40 mg/kg, i.p.) on gene expression of parkin and its substrate Pael-receptor (R) in the dopamine-rich areas of the rat brain, using reverse transcription-polymerase chain reaction. parkin mRNA levels in the striatum, but not in other regions, decreased at 1 and 2 h and returned to the pre-drug basal levels at 4 h after METH administration. METH also decreased Pael-R mRNA levels in the striatum and substantia nigra within 2 h after METH, while haloperidol (2 mg/kg, s.c.) increased Pael-R mRNA levels in the substantia nigra at 2 h after administration. These results suggest that temporary suppression of gene expression of parkin and Pael-R may be associated with the METH-induced dopaminergic neurotoxicity. Taken together with our previous report, dopaminergic modulation of the expression of parkin and Pael-R genes in the nigro-striatal pathway may have significant implication for pathophysiology and treatment of parkinson disease.

Animals↗
PubMed2003

Vaccination of guinea pigs with DNA encoding Ag85A by gene gun bombardment.

A DNA vaccine encoding Ag85A from Mycobacterium tuberculosis was administered to guinea pigs by epidermal gene gun bombardment and its protective efficacy was determined. Vaccination with Ag85A DNA twice significantly reduced the severity of pulmonary pathology and number of pulmonary colony-forming units (CFU) (p<0.01). When immunogenic synthetic Ag85A peptide was used as a booster, lung pathology was improved significantly and pulmonary CFU were reduced dramatically. Neither Ag85A DNA nor BCG Tokyo protected the guinea pigs from hematogenous spread of tubercle bacilli to the spleen because splenic granulomas without central necrosis were recognized. When the vaccinated guinea pigs were followed up for 7 months, the pulmonary lesions became fibrotic in guinea pigs vaccinated with Ag85A DNA plus Ag85A peptide, or BCG Tokyo, and no tubercle bacilli were detected. The protective efficacy of the tuberculosis Ag85A DNA vaccine was improved significantly by peptide boosting. It is concluded that dosage and peptide boosting are important in the induction of higher protective efficacy by a tuberculosis DNA vaccine.

Acyltransferases↗
PubMed2003

Effects of tea catechin inhalation on methicillin-resistant Staphylococcus aureus in elderly patients in a hospital ward.

We investigated the effects of inhalation of tea catechin on MRSA in the 24 elderly in patients, who were known to carry MRSA in sputum. The patients in the catechin group (N=12) were administered an inhalation of tea catechin extracts (in saline/bromhexine) (3.7 g/L catechins, 43% of them are composed of epigallocatechin gallate), three times daily with hand nebulizer for four weeks. The clinical effects were compared with the control group (N=12) who were given an inhalation of saline/bromhexine alone. After a week of the course, the numbers of the patients with decreased or disappearance of MRSA in their sputum was significantly higher in the catechin group, compared with that in the control group (seven vs. no patients; P<0.05). The number of patients discharged during the study was significantly increased, and the days of hospital stay were significantly decreased in the catechin group compared with those in the control group (six vs. one patient; P<0.05, 51+/-22 vs. 85+/-50 days, mean+/-S.D.;P <0.05, respectively). No adverse effects were observed in any patients during the study. Catechin inhalation seemed to be safe, and at least temporarily effective in the reduction of MRSA and shortening of hospitalization.

Activities of Daily Living↗
PubMed2003

Induction of NGF synthesis in astrocytes by onjisaponins of Polygala tenuifolia, constituents of kampo (Japanese herbal) medicine, Ninjin-yoei-to.

The effect of a kampo medicine, Ninjin-yoei-to (NYT; Ren-shen-yang-rong-tang in Chinese) on nerve growth factor (NGF) secretion from the cultured rat astrocytes was examined in vitro. When rat embryo astrocytes were cultured in the presence of NYT for 24 h, the amount of NGF in the medium was significantly increased in a dose dependent manner. Among 14 kinds of component herbs in NYT, the roots of Polygala tenuifolia and roots of Panax ginseng extracts increased NGF levels from the astrocytes. Saponin fraction from the roots of P. tenuifolia enhanced the production of NGF, however phenolic glycoside fraction showed no effect. Onjisaponins A, B, E, F and G as major saponins of the root of P. tenuifolia strongly increased the NGF level, whereas ginsenosides Rb1 and Rg1 did not affect the NGF level. Onjisaponin F also induced ChAT mRNA level in rat basal forebrain cells. These results indicate the possibility that NYT and/or onjisaponins in P. tenuifolia may have potential therapeutic effects for the treatment of Alzheimer disease patients.

Animals↗
PubMed2003

Glutathione S-transferase M1 and T1 polymorphisms and the risk of recurrent pregnancy loss.

The aetiology of recurrent pregnancy loss (RPL) remains unclear, but it may be related to a possible genetic predisposition together with involvement of environmental factors. We examined the relation between RPL and polymorphisms in two genes, glutathione S-transferases (GST) M1 and T1, which are involved in the metabolism of a wide range of environmental toxins and carcinogens. A case-control study of 115 cases with RPL and 160 controls was conducted. All cases and controls were women resident in Sapporo, Japan and the surrounding area. They were genotyped for polymorphisms of GSTM1 and GSTT1 using PCR-based methods. We found that 65.2% of the cases with RPL and 45.6% of the controls had the GSTM1 null genotype [odds ratio (OR) = 2.23, 95% confidence interval (CI) = 1.36-3.66]. On the other hand, 47.0% of the cases and 49.4% of the controls had the GSTT1 null genotype (OR = 0.95; 95% CI = 0.58-1.55). The results suggest that women with GSTM1 null polymorphism may therefore have an increased risk of RPL.

Abortion, Habitual↗
PubMed2003

A polymorphism in the CYP17 gene relates to the risk of recurrent pregnancy loss.

The CYP17 gene encodes the enzyme cytochrome P450c17alpha, which mediates both 17alpha-hydroxylase and 17,20-lyase activity in the steroid biosynthesis pathway. A T-->C polymorphism in the 5' promoter region of CYP17 has been described. To examine the association between recurrent pregnancy loss (RPL) and a polymorphism in CYP17, a case-control study of 117 cases with RPL and 164 controls was conducted. This polymorphism was investigated by PCR/restriction fragment length polymorphism using DNA from peripheral lymphocytes. The T-->C transition in the variant allele (A2) creates a new recognition site for the restriction enzyme MspA1, which permits designation of the wildtype allele (A1) and A2. Women with the A2 allele of CYP17 had an increased risk of RPL [A1/A1 genotype (reference); A1/A2 genotype: odds ratio (OR), 1.68; 95% confidence interval (CI), 0.94-3.01; A2/A2 genotype: OR, 2.37; 95% CI, 1.16-4.83; P trend, 0.016]. Additionally, there was a similar tendency for the increased risk of primary RPL [A1/A1 genotype (reference); A1/A2 genotype: OR, 2.14; 95% CI, 1.14-4.01; A2/A2 genotype: OR, 2.50; 95% CI, 1.16-5.41; P trend, 0.015]. These results suggest that possession of the A2 variant of CYP17 may predispose to an increased risk of RPL with a gene dosage effect.

Abortion, Habitual↗
PubMed2003

Relative importance of STAT4 in murine tuberculosis.

This study was designed to determine the roles of STAT proteins in defence against mycobacterial infection. Airborne infection of STAT4 knockout (KO) mice with a Mycobacterium tuberculosis strain induced large granulomas with massive neutrophil infiltration over time, while that in STAT6 KO mice did not. The STAT4 KO mice succumbed to mycobacterial infection by the 80th day after infection. Compared with the levels in wild-type (WT) and STAT6 KO mice, pulmonary inducible nitric oxide synthase, interferon-alpha, -beta and -gamma mRNA levels were significantly lower in STAT4 KO mice, but expression of interleukin-2, -6, -12 and -18 mRNAs was slightly higher up to the fifth week after aerial infection. Therefore, STAT4, but not STAT6, appears to be a critical transcription factor in mycobacterial regulation.

Animals↗
PubMed2003

The influence of early ambulation and other factors on headache after lumbar myelography.

In order to determine the influence of early ambulation and other factors on headaches occurring after lumbar myelography we randomised 207 patients (127 men and 80 women) into two groups. Following the investigation, we allowed the 101 patients (65 men and 36 women) in group A to sit or stand freely, while we confined the 106 patients (62 men and 44 women) in group B to bed for 20 hours. The nine patients in group B who could not maintain bed rest were excluded. There was no significant difference between the two groups as regards the prevalence of spinal headache (8.9% in group A v 14.4% in group B). Patients who reported headaches, however, were significantly more likely to be women (18.7%) than men (73%), be younger (mean age 45 years v 56 years), have a higher cerebrospinal pressure before removal of fluid (mean values 172 v 137 mm H2O) and a lower systolic (mean values 120 v 134 mmHg) and diastolic blood pressure. We conclude that, although other factors may be associated with headaches, late ambulation is not effective in preventing spinal headaches after lumbar myelography.

Adult↗
PubMed2003

Sustainable veterinary medicine for the new era.

Sustainability aims to harmonise life on Earth without compromising the essential natural resources that should be the birthright of future generations. 'Sustainable medicine' (SM) is just one component of the wide range of possible sustainable approaches to peaceful co-existence. Sustainable medicine envisions an uncomplicated system of maintaining the health of people and animals, both now and for many years to come. This type of medicine is based on ancient wisdom, knowledge and healing arts, combined with the advantages and technical achievements of modern science and other areas of medicine; it is an integrated approach to preventive, safe and affordable healing. The term sustainable medicine also implies that the main therapeutic materials used in the course of practising this type of medicine can be replaced or replenished with minimal environmental damage after harvesting. The aim of sustainable medicine is to maintain the balance of nature, allowing an estimated 7 to 100 million species of life forms to co-exist and reproduce, and to sustain the long-term future of this planet. The world is in the midst of an environmental crisis: anthropogenic environmental damage in the last century was greater than in any previous century. One of the major concerns is the misuse of medicines, and the resulting immune depletion in people and animals. Many traditional medical systems have taught that appropriate adaptation by, and of, an effective defence system is the key to health and survival. This is only possible if priority is given to a preventive rather than a curative approach to health care; the very same approach that is advocated by proponents of SM: an approach based on proper diagnosis and the use of personalised, tailor-made medicine. The authors propose SM (the combination of the advantages of modern, traditional and complementary medical systems) as the best approach to providing better health care services for people and animals. The article presents a brief history of traditional medicines and outlines strategies for developing SM. The authors highlight some important factors in the development of SM in animal health care and attempt to encourage veterinarians to adopt a sustainable approach to treating animals.

Animals↗
PubMed2002

1H-MR spectroscopy and gray matter volume of the anterior cingulate cortex in schizophrenia.

Schizophrenic and normal control subjects were examined using both H-magnetic resonance spectroscopy (MRS) and structural MR imaging, in order to accurately assess the partial volume within the spectroscopic volume of interest (VOI) in the anterior cingulate cortex. The gray matter volume within VOI correlated positively with the N-acetyl-aspartate (NAA) to choline (Cho) ratio in schizophrenics only, not in controls. Schizophrenic patients had a reduced NAA/Cho ratio and an elevated Cho/creatine ratio compared to controls after the partial volume effect was eliminated. There was a significant negative correlation between the NAA/Cho ratio and the severity of blunted affect symptom in schizophrenics. These results provide further support to the idea that the measures of H-MRS indicate not only neuronal loss but also neuronal dysfunction in schizophrenia.

Adult↗
PubMed2002

Differential amygdala response during facial recognition in patients with schizophrenia: an fMRI study.

Human lesion or neuroimaging studies suggest that amygdala is involved in facial emotion recognition. Although impairments in recognition of facial and/or emotional expression have been reported in schizophrenia, there are few neuroimaging studies that have examined differential brain activation during facial recognition between patients with schizophrenia and normal controls. To investigate amygdala responses during facial recognition in schizophrenia, we conducted a functional magnetic resonance imaging (fMRI) study with 12 right-handed medicated patients with schizophrenia and 12 age- and sex-matched healthy controls. The experiment task was a type of emotional intensity judgment task. During the task period, subjects were asked to view happy (or angry/disgusting/sad) and neutral faces simultaneously presented every 3 s and to judge which face was more emotional (positive or negative face discrimination). Imaging data were investigated in voxel-by-voxel basis for single-group analysis and for between-group analysis according to the random effect model using Statistical Parametric Mapping (SPM). No significant difference in task accuracy was found between the schizophrenic and control groups. Positive face discrimination activated the bilateral amygdalae of both controls and schizophrenics, with more prominent activation of the right amygdala shown in the schizophrenic group. Negative face discrimination activated the bilateral amygdalae in the schizophrenic group whereas the right amygdala alone in the control group, although no significant group difference was found. Exaggerated amygdala activation during emotional intensity judgment found in the schizophrenic patients may reflect impaired gating of sensory input containing emotion.

Adolescent↗
PubMed2002

Diffusion-weighted magnetic resonance imaging of dural sinus thrombosis.

Magnetic resonance imaging (MRI) is useful to diagnose dural sinus thrombosis. However, the representative appearance of dural sinus thrombosis on diffusion-weighted MRI has not been established. This study was aimed at determining whether cytotoxic or vasogenic edema is more predominant in the affected cerebral parenchyma and assessing the time courses and prognosis of dural sinus thrombosis lesion. The studies on sixteen patients with dural sinus thrombosis who underwent diffusion-weighted MRI were retrospectively reviewed. The diagnosis was confirmed by digital subtraction angiography in 11 patients and magnetic resonance angiography in five patients. Diffusion-weighted images with echo-planar imaging were obtained using two or three b values, with the highest b value of up to 1,000 s/mm(2). A region of interest was placed on an area of abnormal signal intensity to calculate apparent diffusion coefficients (ADCs). Nine of the 16 patients had lesions with an increased ADC, whereas, three of these nine patients also had lesions with a decreased ADC. Among 11 patients who underwent initial MRI within 7 days of their last episode, eight had lesions with an increased ADC, of whom three had lesions mixed with both decreased and increased ADC areas. Follow-up studies of these three patients revealed the development of hemorrhagic infarction in two and subcortical hemorrhage in one. Vasogenic edema develops more predominantly and earlier in dural sinus thrombosis, though cytotoxic edema was also associated with the pathological changes in the early phase. Decrease of ADC value is presumed to reflect severe pathological conditions and indicate possible future development of infarction or hemorrhage.

Adult↗
PubMed2002

Island dynamics in the large-helical-device plasmas.

In the Large Helical Device plasma discharges, the size of an externally imposed island with mode number ( n/m = 1/1) decreases substantially when the plasma is collisionless ( nu(*)< approximately 1) and the beta is finite ( > approximately 0.1%) at the island location. For the collisional plasmas with finite beta, on the other hand, the size of the island increases. However, there is a threshold in terms of the vacuum island size below which the island enlargement is not seen.

Journal Article↗
PubMed2002

Effect of the antiulcer polysaccharide fraction from Bupleurum falcatum L. on the healing of gastric ulcer induced by acetic acid in rats.

An antiulcer polysaccharide fraction (BR-2) from Bupleurum falcatum L. was examined for its effect on the healing of chronic ulcers induced by acetic acid in rats. When BR-2 was administered orally to the rats, it was shown to be effective in the healing of acetic acid-induced chronic ulcer. This result suggests that the use of herbal prescriptions containing B. falcatum L. may prove useful for the treatment of peptic ulcers.

Acetic Acid↗
PubMed2002

The presence and severity of vertebral fractures is associated with the presence of esophageal hiatal hernia in postmenopausal women.

We examined the relationship between the presence of esophageal hiatal hernia (HH) assessed by endoscopy and the presence of vertebral fractures (VFs) in 87 Japanese postmenopausal women (age range 52-87 years). We found that 29 (63%) of 46 patients with HH (71.2+/-6.1 years, mean +/- SD) had one or more VFs, compared with 14 (34%) of 41 patients without HH (70.8+/-6.8 years), which was a significant difference in the frequency of VFs (c2 = 7.242; p = 0.0071). The average number of VFs per patient was significantly higher for the patients with HH than for those without HH (1.67+/-1.75 vs 0.68+/-1.21, p = 0.0032). There were no significant differences in absolute or age-matched bone mineral density (BMD) values at the lumbar spine (0.656+/-0.131 vs 0.662+/-0.148 g/cm2; Z-score, -0.35+/-1.17 vs -0.26+/-1.00) and there were no significant differences in biochemical parameters, age, years since menopause or body mass index (BMI) between the two groups. When patients were divided into those with reflux esophagitis (RE) (n = 30, 70.2+/-7.3 years) and those without RE (n = 57, 71.4+/-5.9 years), no significant differences were detected in any of the above parameters including the presence or number of VFs. The patients were further subdivided into four groups: those with 'HH only' (n = 23, 72.3+/-4.6 years), with 'RE only' (n = 7, 70.9+/-7.7 years), with 'both' (n = 23, 70.0+/-7.3 years) and with 'neither' (n = 34, 70.8+/-6.7 years). One or more VFs were found in 12 (52%), 1 (14%), 17 (74%), and 13 (38%) patients in each group, respectively, and the difference in frequency was significant (c2 = 10.748; p = 0.0132). The average number of VFs per patient in each group was 1.57+/-2.06, 0.14+/-0.38, 1.78+/-1.41 and 0.79+/-1.30, respectively, and there were significant differences between the 'both' and 'neither' groups, and between the 'both' and 'RE only' groups (p<0.05). When univariate logistic regression analysis was performed with the presence of HH as a dependent variable and each of the presence of VFs, the number of VFs per patient, absolute or age-matched BMD values at the lumbar spine, BMI and plasma albumin as independent variables, the presence of VFs and the number of VFs per patient were selected as indices affecting the presence of HH (odds ratio: 3.29 and 1.59, 95% confidence interval: 1.36-7.94 and 1.14-2.23; p=0.0080 and 0.0064, respectively). These results show that the presence and severity of VFs are associated with the presence of HH but not of RE in Japanese postmenopausal women, and suggest that kyphosis induced by multiple VFs might predispose elderly women to a complication with HH.

Aged↗
PubMed2002

Increased levels of a TH2-type CC chemokine thymus and activation-regulated chemokine (TARC) in serum and induced sputum of asthmatics.

BACKGROUND: Cytokines liberated by TH2 cells play crucial roles in the pathogenesis of bronchial asthma. Recent studies have demonstrated that CC chemokine receptor (CCR)4 is preferentially expressed by TH2 cells. These facts suggest possible involvement of two CCR4-specific ligands i.e., thymus and activation-regulated chemokine (TARC) and macrophage-derived chemokine (MDC), in the pathogenesis of bronchial asthma via recruitment of TH2 cells to inflammatory sites. We investigated the levels of TARC and MDC in the serum and induced sputum of asthmatics. METHODS: The levels of TARC in the serum (46 asthmatics and 26 healthy subjects) and induced sputum (30 asthmatics and 6 healthy subjects) were measured using a highly sensitive ELISA system. The levels of eotaxin and MDC were also measured by ELISA. RESULTS: TARC, but not MDC, was significantly increased in asthmatic sera (P<0.001). Although MDC was undetectable in the sputum of most cases by our assay system, sputum TARC was significantly increased (P=0.027). CONCLUSIONS: The elevated TARC levels in asthmatics might be involved in the pathophysiology of asthma.

Adult↗