Biomedical subjects

Hidehiro Watanabe

Publications and source records attributed to Hidehiro Watanabe.

8 recordsLinked to original sources

PubMed2006

In vivo localized 1H MR spectroscopy of rat testes: stimulated echo acquisition mode (STEAM) combined with short TI inversion recovery (STIR) improves the detection of metabolite signals.

A noninvasive NMR technique for evaluating testicular function was explored in this study. Localized in vivo 1H NMR spectroscopy was performed on rat testes using a stimulated echo acquisition mode (STEAM) sequence with a short echo time (TE). In the 1H spectra, large lipid signals dominated the chemical shift range of 0.89-2.78 ppm, which prevented the observation of metabolite signals in this region. To suppress these lipid signals, short inversion time (TI) inversion recovery (STIR) was combined with STEAM (STIR-STEAM). The optimal TI was typically 320 ms. STIR-STEAM with a TE of 15 ms allowed successful suppression of the lipid signals and the sensitive detection of several new metabolite signals. In normal testes, choline, creatine, glutamate, and glycine signals were identified. In addition to these metabolites, a lactate signal was observed in ischemic testes. To our knowledge, the signals of glutamate, glycine, and lactate have not been previously assigned in 1H MR spectra of testes in vivo. Lipid suppression by STIR aided in the detection of these metabolites, which would otherwise have been masked by the lipid signals.

Animals↗

PubMed2006

Classical conditioning of activities of salivary neurones in the cockroach.

Secretion of saliva to aid swallowing and digestion is a basic physiological function found in many vertebrates and invertebrates. For mammals, classical conditioning of salivation in dogs was reported by Pavlov a century ago. However, conditioning of salivation or of related neural activities in non-mammalian species has not been reported. In many species of insects, salivation is regulated by salivary neurones. In this study, we found that salivary neurones of the cockroach Periplaneta americana exhibited a strong response to sucrose solution applied to the mouth and a weak response to odours applied to an antenna, and we studied the effect of conditioning on the activities of salivary neurones. After three sets of differential conditioning trials in which an odour was presented just before the presentation of sucrose solution and the other odour was presented alone, the response of salivary neurones to sucrose-associated odour significantly increased but that to the odour presented alone was unchanged. Backward pairing trials in which an odour was presented after the presentation of sucrose solution were not effective in achieving conditioning. Our study of the change in the level of saliva secretion in response to electrical stimulation of salivary neurones suggested that the magnitude of increase in odour response of salivary neurones by conditioning is sufficient to lead to an increased level of salivation. This study suggests classical conditioning of salivation in an insect.

Animals↗

PubMed2005

Carbon 13-labeled magnetic resonance spectroscopy observation of cerebral glucose metabolism: metabolism in MELAS: case report.

BACKGROUND: Carbon 13-labeled magnetic resonance spectroscopy ((13)C-MRS) with [(1-13)C]-glucose administration, the (13)C atom that behaves as a radio inactive tracer in the brain, can differentiate aerobic and anaerobic glucose metabolism by detecting [(4-13)C]-glutamate (Glu C4) and [(3-13)C]-lactate (Lac C3). OBJECTIVE: To investigate the cerebral metabolic derangement resulting from mitochondrial dysfunction in mitochondrial myopathy, encephalopathy, lactic acidosis, and strokelike episodes (MELAS). DESIGN: Application of a new (13)C-MRS technique to a patient with MELAS compared with control subjects (n = 7). PATIENT: A 19-year-old woman with an A3243G mitochondrial mutation who underwent (13)C-MRS for 30 minutes after oral administration of [(1-13)C]-glucose (0.75 g/kg). RESULT: Decreased Glu C4-labeling (P<.001) and increased Lac C3 synthesis (>2 SDs) compared with controls were demonstrated in the patient with MELAS. CONCLUSIONS: This first report on (13)C-MRS observation of cerebral glucose metabolism in a patient with MELAS demonstrated the presence of low glutamate production via the tricarboxylic acid cycle compared with high lactate synthesis by glycolysis. The present findings suggest that the clinical use of (13)C-MRS can be extended to diagnose mitochondrial dysfunction and monitor cerebral glucose metabolism in a variety of mitochondrial disorders.

Adult↗

PubMed2004

Comparative study between DNA copy number aberrations determined by quantitative microsatellite analysis and clinical outcome in patients with stomach cancer.

PURPOSE: We detected the relative DNA copy numbers (RCNs) at target loci in patients with stomach cancer with quantitative microsatellite analysis. We additionally clarified the relationship between DNA copy number aberrations and the clinical outcome of the patients. EXPERIMENTAL DESIGN: Fresh frozen samples were obtained from 30 patients who had undergone surgery for stomach cancer. Seven microsatellite loci in chromosomes 8q, 16q, and 20q and one gene-specific locus (ZNF217) were selected as the target loci. The DNA copy number was obtained relatively to a pooled reference consisting of six microsatellite primer sets selected from the regions where few aberrations have been reported in comparative genomic hybridization analysis. On the basis of the TaqMan PCR system, the internal probes used were carrying donor (6-carboxyfluorescein) and acceptor (6-carboxytetramethylrhodamine) fluorescent molecules complementary to CA repeats in the microsatellite markers and to one gene-specific oligomer in the gene-specific marker. RESULTS: Chromosome 8q gain, 20q gain, and 16q loss were detected in 18 (60.0%), 8 (26.7%), and 13 (43.3%) cases, respectively. Gains in the RCNs of D8S1801 and D8S1724 were most frequently found (36.7%). There was a significant correlation between the loss of D16S3026 and reduced survival duration (P = 0.0158), and the simultaneous aberrations of D8S1801 gain and D16S3026 loss (double marker positive) was significantly associated with reduced survival duration (P = 0.0008). According to Cox proportional hazards model, the double marker positive was a significant and independent factor indicating an unfavorable prognostic factor (relative risk, 17.176; 95% confidence interval, 2.782-106.026; P = 0.0022). CONCLUSION: RCN aberrations in tumor tissues determined by quantitative microsatellite analysis enable identification of the prognostic factors that correlate with clinical outcome of the patients with stomach cancer.

Aged↗

PubMed2003

Classical olfactory conditioning in the cockroach Periplaneta americana.

We established a classical conditioning procedure for the cockroach, Periplaneta americana, by which odors were associated with reward or punishment. Cockroaches underwent differential conditioning trials in which peppermint odor was associated with sucrose solution and vanilla odor was associated with saline solution. Odor preference of cockroaches was tested by allowing them to choose between peppermint and vanilla sources. Cockroaches that had undergone one set of differential conditioning trials exhibited a significantly greater preference for peppermint odor than did untrained cockroaches. Memory formed by three sets of differential conditioning trials, with an inter-trial interval of 5 min, was retained at least 4 days after conditioning. This conditioning procedure was effective even for cockroaches that had been harnessed in plastic tubes. This study shows, for the first time in hemimetaborous insects, that both freely moving and harnessed insects are capable of forming olfactory memory by classical conditioning procedure. This procedure may be useful for future electrophysiological and pharmacological studies aimed at elucidation of neural mechanisms underlying olfactory learning and memory.

Animals↗

PubMed2002

Helicobacter pylori and acetylsalicylic acid synergistically accelerate apoptosis via Fas antigen pathway in rabbit gastric epithelial cells.

The mechanism for gastric epithelial cellular apoptosis by both H. pylori and NSAIDs remains unknown. Normal gastric epithelial cells, collected from rabbit stomach, were cultured with viable H. pylori and/or an acetylsalicylic acid for 24 hr as an in vitro model of gastric epithelial cell injury. The Fas antigen expression rate in the gastric epithelial cells was measured using a FACScan. In group E, in which H. pylori inoculation of epithelial cells was followed by treatment with an NSAID, the rate of Fas antigen expression was significantly higher than the rate observed after treatment with either H. pylori or NSAID alone. Despite the fact that drug treatment alone did not significantly increase the Fas expression rate vs control cells. The results suggest that H. pylori and NSAID induce gastric cell injury as apoptosis via the Fas antigen pathway in a synergistic manner and that this effect is particularly strong when NSAID treatment follows H. pylori infection.

Animals↗

PubMed2002

[A case of Nocardia farcinica pneumonia treated with sulfamethoxazole-trimethoprim monitoring its serum concentration].

A 75-year-old male suffered from interstitial pneumonia in December 2000 and treated with predonisolone. The treatment was effective, and the dosage of predonisolone had been gradually tapered. In January 2001, when the dosage was 30 mg/day, he complained of cough and yellowish sputum. The chest X-ray and CT revealed bilateral infiltrations with cavities. He was treated with cefozopram and fluconazole. However, there were no improvements. The sputa of the 2nd, 3rd, 6th and 8th hospital days showed the presence of gram-positive branched rods, which were identified as Nocardia farcinica. Therefore, the treatment was changed to sulfamethoxazole-trimethoprim. During the treatment, serum concentration of sulfamethoxazole was repeatedly measured, and kept over 60 microgram/ml. He was swiftly recovered after the start of sulfamethoxazole-trimethoprim. This case was supposed to be the seventh one of N. farcinica pneumonia in Japan, and the measurement of the concentration of sulfamethoxazole was useful to determine its dosage.

Aged↗

PubMed2002

Animal model of Mycoplasma pneumoniae infection using germfree mice.

We have attempted to establish a gnotobiotic mouse model monoassociated with Mycoplasma pneumoniae following single or repeated infection to examine the mechanism of pathogenesis following M. pneumoniae infection. M. pneumoniae inoculated into germfree mice colonized equally well at 10(5) CFU/lung in both single infection and repeated infection. In histopathological observation, repeatedly infected mice showed pneumonia with mild infiltration of mononuclear cells and macrophages. Antibody titers against M. pneumoniae rose in the repeatedly infected mice but not in the singly infected mice. The percentage of CD4-positive, CD8-positive, and CD25-positive lymphocytes infiltrated in the lung was increased in the repeatedly infected mice. In contrast, the lymphocyte subset in the spleen was not significantly different among mock-, singly, and repeatedly infected mice. In the study of cytokine productivity of spleen cells, production of interleukin (IL)-4 and IL-10 was significantly increased and that of gamma interferon was remarkably increased in the mice following repeated infection. These results indicate that a gnotobiotic mouse model monoassociated with M. pneumoniae was established and that immune mechanisms might be involved in the pathogenesis in pneumonia following M. pneumoniae infection.

Animals↗