Biomedical subjects

S Honma

Publications and source records attributed to S Honma.

At least 37 records · Page 2Linked to original sources

PubMed2001

Effect of rotavirus vaccine on Sapporo virus gastroenteritis in Finnish infants.

BACKGROUND: Sapporo-like viruses (SLVs) occur worldwide, but there is limited information about the SLV-associated gastroenteritis outside Japan. METHODS: Stool specimens from 1,432 episodes of gastroenteritis that occurred in children between 2 months and 2 years of age during a rotavirus vaccine trial (776 episodes in placebo-vaccinated and 656 in rotavirus-vaccinated infants) were examined for SLVs using a reverse transcription-PCR assay. The reverse transcription-PCR took advantage of new primers specific for Sapporo virus genetic clusters I, II and III; SV/SV82 (SV/Sapporo virus 82); SV/Lond92 (SV/ London 92); and SV/PV (Parkville virus). RESULTS: SLVs were detected in association with 132 (9.2%) of all episodes; in 80 (5.6%) episodes SLV was the only gastroenteritis virus detected. The epidemic season of SLVs peaked from March to May concurrently with rotaviruses and astroviruses and overlapping withNorwalk-like viruses. Clinically SLV gastroenteritis was characterized by a mild diarrheal disease, being sharply different from the Norwalk-like virus-associated "winter vomiting disease." Rotavirus vaccination did not have any effect on the number of SLV episodes, but the intensity and duration of SLV-associated diarrhea were reduced in rotavirus-vaccinated children compared with placebo-vaccinated children (P = 0.0008). CONCLUSIONS: SLVs are common causative agents of acute gastroenteritis in young Finnish children. SLV disease is characterized by diarrhea, which is usually mild but can be severe. By an unknown mechanism rotavirus vaccine seems to reduce the severity of SLV-associated diarrhea.

Caliciviridae Infections↗

PubMed2001

Clinical severity of Norwalk virus and Sapporo virus gastroenteritis in children in Hokkaido, Japan.

OBJECTIVE: To clarify the clinical significance and etiologic impact of Norwalk virus (NV) and Sapporo virus (SV) in viral gastroenteritis in Japanese children. STUDY DESIGN: Two outbreaks each of NV gastroenteritis and SV gastroenteritis occurring in an infant home in Sapporo, Japan, as well as 95 hospitalized children with acute gastroenteritis were retrospectively evaluated using a 0- to 20-point clinical severity scoring system. RESULTS: The mean severity scores for NV and SV gastroenteritis outbreaks were 7.9 and 5.2, respectively, as compared with 8.4 for rotavirus A gastroenteritis that occurred in the same infant home. Among 95 hospitalized children with acute gastroenteritis, rotavirus A was detected in 47% followed by NV in 18%. SV was not found. CONCLUSION: Our data indicate that NV can cause severe gastroenteritis and is an important etiologic agent in hospitalized cases, whereas SV causes mild gastroenteritis in Japanese children.

Acute Disease↗

PubMed2001

Phase-advance shifts of human circadian pacemaker are accelerated by daytime physical exercise.

Effects of forced sleep-wake schedules with and without physical exercise were examined on the human circadian pacemaker under dim light conditions. Subjects spent 15 days in an isolation facility separately without knowing the time of day and followed a forced sleep-wake schedule of a 23 h 40-min period for 12 cycles, and physical exercise was imposed twice per waking period for 2 h each with bicycle- or rowing-type ergometers. As a result, plasma melatonin rhythm was significantly phase advanced with physical exercise, whereas it was not changed without exercise. The difference in phase was already significant 6 days after the start of exercise. The amplitude of melatonin rhythm was not affected. A single pulse of physical exercise in the afternoon or at midnight significantly phase delayed the melatonin rhythms when compared with the prepulse phase, but the amount of phase shift was not different from that observed in the sedentary controls. These findings indicate that physical exercise accelerates phase-advance shifts of the human circadian pacemaker associated with the forced sleep-wake schedule.

Adult↗

PubMed2001

Pneumocystis carinii pneumonia with an atypical granulomatous response in a patient with chronic lymphocytic leukemia.

We have recently seen a patient who developed Pneumocystis carinii pneumonia (PCP) in the course of treatment for chronic lymphocytic leukemia (CLL). This case showed uncommon pathological findings with extensive formation of granulomatous lesions. Despite advanced CLL associated with poor B-cell function, she responded well to anti-PCP treatment. In contrast to B-cell function, the T-cell functions were well preserved in vitro, and the numbers of peripheral CD4- and CD8-positive cells were normal, and T-cell functions were normal. These findings suggest that the production of granulomatous lesions to PCP may have been associated with the patients' immune status, and that it may constitute a good indicator in PCP infection in patients with underlying hematological malignancy.

Bronchoalveolar Lavage↗

PubMed2000

Synaptic communication of cellular oscillations in the rat suprachiasmatic neurons.

Circadian firing rhythms of cultured rat suprachiasmatic nucleus were measured simultaneously from 4-8 neurons by using a multi-electrode dish and neuronal interactions were examined by a cross-correlation analysis of spontaneous action potentials. Functional connections were detected in the neuron pairs showing synchronized circadian firing rhythms, and when the connections were lost, firing rhythms were desynchronized. After the prolonged treatment with tetrodotoxin, cross-correlation and circadian rhythm synchronization were abolished concomitantly in most neuron pairs. Cellular mechanisms involving Na(+)-channel dependent communication are responsible for the synchronization of the circadian rhythms in individual suprachiasmatic nucleus (SCN) neurons.

Action Potentials↗

PubMed2000

Quantitative ultrastructure of physiologically identified premotoneuron terminals in the trigeminal motor nucleus in the cat.

Little is known about the ultrastructure of synaptic boutons contacting trigeminal motoneurons. To address this issue, physiologically identified premotor neurons (n = 5) in the rostrodorsomedial part of the oral nucleus (Vo.r) were labeled by intracellular injections of horseradish peroxidase (HRP) in cats. The ultrastructure of 182 serially sectioned axon terminals from the five neurons was both qualitatively and quantitatively analyzed. In addition, the effects of the glycine antagonist strychnine, GABA(A) antagonist bicuculline, NMDA antagonist 2-amino-5-phosphonovalerate (APV), and non-NMDA antagonist 6-cyano-7-nitroquinoxaline-2,3-dione (CNQX) on Vo.r-induced postsynaptic potentials in trigeminal motoneurons (n = 11) were examined to evaluate potential signaling substances of the premotor neurons. Labeled boutons made synaptic contacts with either jaw-closing or -opening motoneurons. All the boutons contained pleomorphic vesicles, and most formed a single symmetric synapse either on the somata or on primary dendrites. Morphometric analyses indicated that bouton volume, bouton surface area, apposed surface area, total active zone area, and mitochondrial volume were not different between boutons on jaw-closing and -opening motoneurons. Vesicle number and density, however, were higher for boutons on jaw-closing motoneurons. The five morphological parameters were positively correlated with bouton volume. Vesicle density was the exception, which tending to be negatively correlated. Intravenous infusion of strychnine or bicuculline suppressed Vo.r-induced inhibitory postsynaptic potentials (IPSPs) in jaw-closing motoneurons. Abolition of Vo. r-induced excitatory postsynaptic potentials in jaw-opening motoneurons with APV and CNQX unmasked IPSPs. The present results suggest that premotor neurons in the Vo.r are inhibitory and that positive correlations between the ultrastructural parameters associated with synaptic release and bouton size are applicable to the interneurons, as they are in primary afferents.

2-Amino-5-phosphonovalerate↗

PubMed2000

cDNA cloning of a novel bHLH-PAS transcription factor superfamily gene, BMAL2: its mRNA expression, subcellular distribution, and chromosomal localization.

We isolated a human cDNA encoding a novel member of the bHLH-PAS transcription factor superfamily, BMAL2, which is highly similar to, but distinct from, BMAL1. The composite cDNA covered a 1720-bp sequence consisting of a putative 1653-bp open reading frame encoding a polypeptide of 551 amino acids. The deduced BMAL2 product contains a bHLH-PAS domain in its N-terminal region and a variable C-terminus. The overall identity of BMAL2 polypeptide to that of human BMAL1 is 49%. RNA analysis revealed that expression of BMAL2 transcripts was restricted to the fetal brain and to the adult liver in human, while human BMAL1 mRNA was expressed in the brain and skeletal muscle. The chromosomal localization of the human BMAL2 gene was determined by fluorescent in situ hybridization to be localized on chromosome 12 at region p12.2-p11.2. These results suggest that BMAL2 may play different roles from BMAL1 in the embryonic brain and in adult mammals.

Adult↗

PubMed2000

Members of the family caliciviridae (Norwalk virus and Sapporo virus) are the most prevalent cause of gastroenteritis outbreaks among infants in Japan.

Norwalk virus (NV) and Sapporo virus (SV) were approved as type species of the genus Norwalk-like viruses and the genus Sapporo-like viruses, respectively, within the family Caliciviridae. To clarify the importance of NV and SV as causes of gastroenteritis outbreaks in infants, stool samples obtained from 36 outbreaks of nonbacterial gastroenteritis that occurred during 1976-1995 in an infant home in Sapporo, Japan, were examined for diarrhea viruses using electron microscopy, enzyme immunoassays, reverse transcriptase-polymerase chain reaction (PCR), and sequencing of the PCR products. NV and SV were associated with 15 (42%) of the 36 outbreaks and were more prevalent than rotavirus (RV) A, which was associated with 10 (28%) of the 36 outbreaks. Our data indicate that NV and SV were the most common cause of outbreaks of viral gastroenteritis in infants and were indeed more prevalent than RV-A in Sapporo, Japan, during 1976-1995.

Caliciviridae Infections↗

PubMed2000

The development of terminal Schwann cells associated with periodontal Ruffini endings in the rat incisor ligament.

The postnatal development of the terminal Schwann cell, an analogue of the lamellar cell in cutaneous sensory receptors, was examined by histochemistry for non-specific cholinesterase and immunohistochemistry for S-100 protein in the periodontal Ruffini endings of the rat incisor. Double immunohistochemistry for S-100 protein and protein gene product 9.5 (PGP 9.5) was also performed to examine the relationship between terminal Schwann cells and axons. Histochemistry for non-specific cholinesterase was able to demonstrate the age-related development of the terminal Schwann cells; the morphology and distribution of the developing terminal Schwann cells became almost identical to those in adults during postnatal days 15-18. Axons showing PGP 9.5-like immunoreactivity elongated and expanded after arrangement of terminal Schwann cells in the alveolus-related part. This suggests that the terminal Schwann cell is important in the development and maturation of the periodontal Ruffini endings.

Animals↗

PubMed2000

Changes in the endocrine environment of the human prostate transition zone with aging: simultaneous quantitative analysis of prostatic sex steroids and comparison with human prostatic histological composition.

BACKGROUND: It is well-known that the incidence of benign prostatic hyperplasia (BPH) increases with aging. The age-dependent changes in the ratio of serum sex steroid concentrations may play a role in BPH development. To clarify the relationship between the prostatic tissue concentrations of these steroids and age, we established a precise method of simultaneous quantitative analysis for prostatic sex steroids and used this method to investigate the tissue concentrations of three major sex steroids (testosterone, dihydrotestosterone, and estradiol) in the human prostate. METHODS: The methodology for the simultaneous quantitative analysis of prostatic sex steroids was established using castrated rat prostatic tissue, coupled with internal standards, for androgen-deprived medium, and the validation of the method was examined. Human prostatic tissues were collected during surgery and immediately frozen at -70 degrees C. Using our method, the steroidal fractions were extracted, purified, and quantified. The proportions of stroma, epithelium, and glandular lumen were measured on each histological specimen, using an image analyzer. RESULTS: The validation tests showed that our method of quantitative analysis was precise and sensitive enough for the quantification of testosterone, dihydrotestosterone, and estradiol in the prostate. In humans, the prostatic dihydrotestosterone concentration decreased with age, but the concentrations of testosterone and estradiol showed no relation with age. Therefore, the ratio of estradiol to dihydrotestosterone concentration (E2/DHT) in prostate increased with age. The E2/DHT ratio showed a significant positive correlation with the proportion of stroma. CONCLUSIONS: The age-dependent decrease in prostatic dihydrotestosterone and constant estradiol concentration lead to a relatively estrogen-dominant environment compared to that at younger ages. We assume that this relatively estrogen-dominant status induces stromal proliferation by some mechanism and leads to the development of BPH.

Aged↗

PubMed2000

Circadian release of excitatory amino acids in the suprachiasmatic nucleus culture is Ca(2+)-independent.

We have previously reported that spontaneous release of excitatory amino acids (aspartate and glutamate) show remarkable circadian rhythms in the organotypic slice culture of rat suprachiasmatic nucleus (SCN). Here we showed effects of extracellular Ca(2+) removal and of L-trans-pyrrolidine-2,4-dicarboxylic acid, a glutamate/aspartate uptake inhibitor on the circadian release of excitatory amino acids in the SCN culture. Amino acids were measured by high-performance-liquid-chromatography. Removal of extracellular Ca(2+) exerted no effect on the spontaneous release of the excitatory amino acids, while it blocked high K(+)-evoked release of the amino acids. Neither the period nor the amplitude of the spontaneous circadian release of amino acids in Ca(2+)-free medium was different from those in the Ca(2+)-containing medium. On the other hand, L-trans-pyrrolidine-2,4-dicarboxylic acid increased the excitatory amino acid levels without affecting the amplitude of excitatory amino acid rhythms. These results indicated that the circadian release of excitatory amino acids in the SCN is Ca(2+)-independent and L-trans-pyrrolidine-2,4-dicarboxylic acid- insensitive. Therefore, Ca(2+)-dependent chemical synaptic transmission may not be involved in the circadian rhythm generation in the SCN.

Animals↗

PubMed2000

Anatomical study of a left single coronary artery with special reference to the various distribution patterns of bilateral coronary arteries.

A left single coronary artery of heart was observed during anatomy practice at Kumamoto University School of Medicine in a 73-year-old female cadaver who died from a thalamic hemorrhage. The left single coronary artery, having a single orifice in the left aortic sinus, bifurcated into the anterior interventricular (IVa) and circumflex (CIR) arteries. No orifice of the right coronary artery was found on the aortic wall. Giving off a branch which traversed the upper part of the infundibulum to supply the anterior upper region of the right ventricle, the IVa descended in the anterior interventricular sulcus to supply the apex of the heart. The CIR curved leftwards in the atrioventricular sulcus to reach the posterior surface, after which it continued to emerge again into the anterior surface. The atrial arteries showed no anomalous distribution pattern and histological observation revealed no pathological abnormality other than a slightly thickened tunica intima. Furthermore, we observed the distribution patterns of bilateral coronary arteries in 377 hearts dissected during anatomical practice over 13 years at Kanazawa University (1980-1986) and Kumamoto University (1993-1998). Although the reason why only the right coronary artery was absent is left unexplained, it was concluded that the left single coronary artery in this study, having the developed left conal and circumflex branches, was an extreme case of the left dominant series of coronary arteries. The formation of single coronary arteries can be explained embryologically by the change of flow in the capillary plexus established on the ventricle wall.

Aged↗

PubMed2000

Synchronization of circadian firing rhythms in cultured rat suprachiasmatic neurons.

The circadian clock in mammals is located in the suprachiasmatic nucleus (SCN) which consists of multiple oscillating neurons. Integration of the cellular oscillations is essential for the generation of a single circadian period in the SCN. By using a multielectrode dish (MED), we measured circadian firing rhythms in individual SCN neurons for more than 2 weeks continuously, and examined the involvement of synaptic communication in the synchronization of circadian rhythms. Cross-correlation analysis of spontaneous action potentials revealed that a neuron pair was functionally connected by synapses when their circadian rhythms were synchronized. No correlation was found between the paired neurons whose circadian rhythms were not synchronized. Calcium (Ca2+)-dependent synaptic transmission in the cellular communication was indicated by dose-dependent lengthening of an intercellular spike interval and loss of spike correlation with a Ca2+ channel blocker. Approximately 60% of the SCN neurons in culture were immunoreactive to antibodies against gamma-aminobutyric acid (GABA) or glutamic acid decarboxylase (GAD). Spontaneous firing of all the neurons tested was either increased or decreased by bicuculline, the GABAA receptor antagonist. These findings indicate that synaptic communication plays a critical role in the synchronization of circadian rhythms in individual SCN neurons and the GABAergic transmission is involved in the synchronization mechanism.

Action Potentials↗

PubMed2000

Involvement of phosphatidylcholine-specific phospholipase C in thromboxane A2-induced activation of mitogen-activated protein kinase in astrocytoma cells.

Thromboxane A2 (TXA2) receptor-mediated signal transduction was investigated in 1321N1 human astrocytoma cells. 9,11-Epithio-11,12-methano-TXA2 (STA2), a TXA2 receptor agonist, induced Ca2+ mobilization and phosphoinositide hydrolysis in a concentration-dependent manner. These responses were inhibited by treatment with U73122, an inhibitor of phosphatidylinositol-specific phospholipase C, or by culturing in 0.5% fetal calf serum containing 0.5 mM dibutyryladenosine 3',5'-cyclic monophosphate (dbcAMP) for 2 days. However, the dbcAMP treatment augmented the TXA2 receptor-mediated phosphorylation of mitogen-activated protein kinase (MAPK). These results were confirmed by a functional MAPK assay measuring the incorporation of 32P into the MAPK substrate peptide. The TXA2 receptor-mediated MAPK activation was inhibited by SQ29548, a TXA2 receptor antagonist, and GF109203X, an inhibitor of protein kinase C. Although U73122 did not inhibit or only slightly inhibited the activation of MAPK, D-609, an inhibitor of phosphatidylcholine-specific phospholipase C, potently attenuated the activation in a concentration-dependent manner. Furthermore, STA2 accelerated the release of [3H]choline metabolites from the cells prelabeled with [3H]choline chloride. This release was inhibited by treatment with D-609. These results suggest that phosphatidylcholine-specific phospholipase C and protein kinase C, but not phosphatidylinositol-specific phospholipase C, are involved in TXA2 receptor-mediated MAPK activation in 1321N1 human astrocytoma cells.

Calcium↗

PubMed2000

Effects of naturally-occurring acid fog on inflammatory mediators in airway and pulmonary functions in asthmatic patients.

Floating fog occurs every summer in Kushiro City in Japan, and the annual average of fog water pH in the past 4 years has been under 5.0. We previously reported that epidemiologically fog was the most important positive factor contributing to increased hospital visits of asthmatic patients compared with other meteorological values and air pollutants. This study aimed to investigate the mechanism of the effects of naturally-occurring acid fog on asthmatic patients. We compared pulmonary functions and inflammatory mediators in induced sputum between the foggy (July 1995) and the non-foggy (May 1996) season, and assessed airway responsiveness to hypo-osmolar aerosol. Forty-four out of 118 asthmatic patients of Kushiro City residents participated, pulmonary function tests were completed in 36 patients, and sputum data were available in 26 patients in both seasons. Percent forced expiratory volume in 1 sec (FEV1) was significantly (P< 0.05) decreased, and % peak expiratory flow rate (PEFR) had a trend to decrease in the foggy season more than in the non-foggy, and sputum eosinophil cationic protein (ECP) and interleukin (IL)-8 were higher in the foggy season but not significantly. A moderate inverse correlation was revealed between sputum ECP and %PEFR in the foggy season (r= -0.55, P<0.005). Subjects were divided into two groups according to the best PEFR; one had >10% lower PEFR levels in the foggy season than in the non-foggy season (Group A, n = 7), the remainder did not (Group B, n = 19). In group A, sputum ECP was significantly increased (P< 0.01) in the foggy season, but there were no changes in IL-8 and prostaglandin D2. Ultrasonic nebulized distilled water provocation test revealed no differences between group A and B. These results suggested that eosinophilic inflammation rather than hypo-osmolar effect of fog might contribute to respiratory deterioration by inhalation of naturally-occurring acid fog.

Acid Rain↗

PubMed2000

Sapporo virus: history and recent findings.

Morphologically distinct caliciviruses of human origin were first found in stools of children with gastroenteritis in 1976. Sapporo virus, or human calicivirus Sapporo, with typical surface morphology was first detected during a gastroenteritis outbreak in a home for infants in Sapporo, Japan, in 1977. Since then, morphologically and antigenically identical virus has been detected frequently in the same institution in association with outbreaks of gastroenteritis. Sapporo virus is widely distributed worldwide, as evidenced by the appearance of antigenically or genetically similar viruses and seroepidemiologic findings. Sapporo virus plays an important role in outbreaks of infantile gastroenteritis and is less important in foodborne outbreaks. Sapporo virus has been approved as the type species of the genus "Sapporo-like viruses in the family Caliciviridae. The history of and recent findings, as obtained by newly developed techniques, about Sapporo viruses are presented.

Caliciviridae↗

PubMed2000

Human caliciviruses in acute gastroenteritis of young children in the community.

Episodes of acute gastroenteritis in prospectively followed children between 2 months and 2 years of age were examined for rotaviruses, enteric adenoviruses, astroviruses, and human caliciviruses, including both Norwalk-like viruses (NLVs) and Sapporo-like viruses (SLVs), using PCR and reverse transcription (RT)-PCR assays. A virus was identified in 60% (502/832) of all episodes and in 85% of the moderately severe or severe episodes. Human caliciviruses were as common as rotaviruses, both being detected in 29% of the cases. NLVs accounted for a 20% etiologic share of all cases; the clinical picture was a moderately severe disease with vomiting as a predominant symptom. SLVs were detected in 9% of the cases, the clinical picture being a mild diarrheal disease. Astroviruses were found in 10% and enteric adenoviruses in 6% of the cases. Diagnosis with PCR and RT-PCR methods increases the detection of all gastroenteritis viruses, particularly human caliciviruses. As a group, human caliciviruses are common causative agents of gastroenteritis in children <2 years of age in Finland, and, of these, NLVs cause more severe disease than SLVs.

Acute Disease↗

PubMed2000

Evaluation of nine sets of PCR primers in the RNA dependent RNA polymerase region for detection and differentiation of members of the family Caliciviridae, Norwalk virus and Sapporo virus.

Norwalk virus and Sapporo virus were approved as type species of the genus "Norwalk-like viruses" and the genus "Sapporo-like viruses," respectively, in the family Caliciviridae. A total of 116 stool specimens containing Norwalk virus (NV) or Sapporo virus (SV) were tested by RT-PCR and Southern hybridization to evaluate nine sets of PCR primers and seven internal oligonucleotide probes in the RNA dependent RNA polymerase region of NV and SV for detection and differentiation of viruses in the NV and SV. Fifty-five stool samples were collected from 11 outbreaks of NV and/or SV gastroenteritis in an infant home, where residents were infants under 2 years of age, in Sapporo, Japan. Sixty specimens were obtained in Sapporo from sporadic cases in children, mainly under 6 years of age, of acute gastroenteritis due to small round structured viruses detected by EM. There is no single primer pair to detect all NV and SV, and at least three primer pairs, G1 set, G2 set and Sapp35/Sapp36, are required to detect viruses in the NV and SV clades. Many NV and SV strains were successfully classified into one of the NV/genogroup I, NV/genogroup II and SV by single-round RT-PCR and Southern hybridization. The new detection method for SV reported in this study combined with those for NV previously reported may elucidate the importance of Norwalk virus and Sapporo virus as a cause of viral gastroenteritis in all age groups in the world.

Blotting, Southern↗