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Biomedical subjects

M Honda

Publications and source records attributed to M Honda.

At least 91 records · Page 5Linked to original sources

Spinorphin, an endogenous inhibitor of enkephalin-degrading enzymes, potentiates leu-enkephalin-induced anti-allodynic and antinociceptive effects in mice.

Spinorphin (LVVYPWT) has been isolated from the bovine spinal cord as an endogenous inhibitor of enkephalin-degrading enzymes. It has been reported that spinorphin has an antinociceptive effect, inhibitory effect on contraction of smooth muscle and anti-inflammatory effect. In the present study, the effects of leu-enkephalin and spinorphin on allodynia and mechanical and thermal nociceptions were examined in vivo using mice. Intrathecal (i.t.) administration of leu-enkephalin or spinorphin inhibited the allodynia induced by intrathecal nociceptin in a dose-dependent manner. Furthermore, spinorphin enhanced the inhibitory effect of enkephalin on allodynia induced by nociceptin. Naloxone antagonized both inhibitory effects of leu-enkephalin and spinorphin, suggesting that the endogenous opioidergic system can modulate allodynia. Intracerebroventricular (i.c.v.) administration of leu-enkephalin increased the nociceptive threshold of heat or mechanical stimulation to a mouse. Although i.c.v. administration of spinorphin had no effect on the threshold of heat or mechanical stimulation, spinorphin enhanced and prolonged the antinociceptive effect of leu-enkephalin. The enhancement of spinorphin on the antinociception produced by leu-enkephalin was reversed by pretreatment with naloxone. From these results, it is suggested that the effects of spinorphin on enkephalin-induced anti-allodynic and antinociceptive effects are due to inhibition of enkephalin-degrading enzymes.

Analgesics↗

Myelodysplasia associated with acquired immunodeficiency syndrome.

Two cases of acquired immunodeficiency syndrome with myelodysplasia are presented. Case 1 was admitted because of Pneumocystis carinii pneumonia. Mild anemia, thrombocytopenia and hypersegmented neutrophils were observed. After the administration of trimethoprim-sulfame-thoxazole and antiretroviral therapy, pancytopenia progressed. Bone marrow (BM) showed dysplastic hematopoiesis, suggesting human immunodeficiency virus-myelopathy. Case 2 was hospitalized due to progressive multifocal leukoencephalopathy. BM specimen obtained for thrombocytopenia showed myelodysplasia similar to myelodysplastic syndrome, suggesting that HIV may have an influence on hematopoietic progenitor cells.

AIDS-Related Opportunistic Infections↗

Excessive fatigue and weight gain among cleanroom workers after changing from an 8-hour to a 12-hour shift.

OBJECTIVES: This study attempted to clarify the health effects of implementing a 12-hour shift in place of the traditional 8-hour shift in work in a clean room in an electronic parts producing factory. METHODS: Health-check records during a year or longer before and after the shift change were reviewed regarding subjective symptoms, height, body weight, and blood pressure for 189 male workers who had moved to a 12-hour shift and for 16 male workers who remained on an 8-hour shift. RESULTS: The workers changing to a 12-hour shift showed significant increases in subjective symptoms, particularly psychological symptoms defined as related to fatigue and bodyweight gain, 1 kg on average, in the year after the shift change. Increased symptoms and body weight remained high even another year later. The workers remaining in the 8-hour shift did not show significant changes in symptoms or body weight during the observation. No changes in blood pressure were observed in relation to the shift move. CONCLUSIONS: The results suggested that implementing a 12-hour shift caused marked psychological fatigue and unhealthy weight gain among some cleanroom workers and that the adaptation to the new work shift did not seem easy for these workers. Working in a clean room can be considered a job in which special caution is needed regarding increased fatigue when a compressed working schedule is implemented. Attention should also be paid to possible weight gain among persons working 12-hour shifts.

Adult↗

[Left ventricular systolic wall motion after exercise stress and myocardial perfusion in patients with ischemic heart disease--investigation by ECG gated myocardial tomography].

To investigate regional left ventricular (LV) wall motion (WM) after recovery from myocardial ischemia, we performed ECG-gated myocardial perfusion tomography with 99mTc-MIBI (G-SPECT) in patients with ischemic heart disease (IHD). In addition, we compared the left ventricular (LV) systolic function obtained by G-SPECT at rest with that obtained by contrast left ventriculography (LVG). We performed G-SPECT at 30 minutes after exercise stress (Ex-30) and 3 hours after exercise (rest). LVWM and LV ejection fractions (EF) were analyzed by the QGS (quantitative gated SPECT) program. The LV was divided into 9 segments and regional WM (RWM) was analyzed quantitatively. In addition, myocardial perfusion was assessed quantitatively. In 64 patients with several different types of heart disease, EF obtained by G-SPECT correlated well with LVG-EF (r = 0.907, p < 0.001), and RWM of G-SPECT coincided well with that of LVG (kappa value 0.67, p < 0.01). Eighty patients with suspected IHD were divided according to Ex-Rest myocardial perfusion. In 83% of patients with Ex-induced perfusion abnormalities disappeared completely at rest, and in 58% of patients with Ex-induced abnormalities disappeared incompletely, RWM abnormalities which were observed at Ex-30 improved at rest and as did EF. In 79% of patients with a fixed defect (FD), RWM abnormalities and EF at Ex-30 did not differ with those at rest, but in 12% of the patients, the RWM abnormality of Ex-30 improved at rest. In most myocardial segments that had recovered from transient ischemia, RWM abnormalities persisted at least 30 minutes after Ex (stunning). In a small portion of the myocardial segments regarded as having myocardial necrosis because of a fixed perfusion abnormality, RWM abnormalities at Ex-30 improved at rest. These segments were supposed to contain viable myocardium. In conclusion, G-SPECT is a powerful method for clarifying the relation between the regional systolic function and myocardial perfusion.

Adult↗

[Surgery for intractable epilepsy in children: pre- and perioperative evaluations with special reference to dipole tracing method estimated from interictal spike].

Methods of preoperative and perioperative evaluation methods for surgical treatment of intractable epilepsy in children are described. Among non-invasive diagnostic methods, EEG-video monitoring is the most fundamental. Amygdalohippocampal volume measurement by MR was useful for the differential diagnosis of mesial temporal lobe epilepsy (TLE) from lateral TLE and generalized epilepsy. The dipole tracing method with a realistic head model was useful for identification of epileptic foci from the interictal spikes of scalp EEG, when an abnormal electric source was estimated as an equivalent current dipole (ECD) in the brain of patients with organic lesion and TLE. ECD concentration ratio ranged from 70 to 90% within 20 mm around the lesion. After lesionectomy seizures disappeared in every patient. The mean distance between the centers of the ECD and epileptic focus (identified by subdural electrode recording) was 14 mm (range: 8 to 18 mm). ECDs of mesial TLE were located in the temporal base rather than mesial temporal lobe, whereas those of lateral TLE in the lateral cortex precisely. In unilateral, intermediate and bilateral TLE, 76%, 52% and 36% of ECDs were localized in the ictal onset zone respectively (p = 0.007). Electrical cortical stimulation with chronically placed intracranial electrodes was used to accurately identify eloquent areas to avoid postsurgical complications. Immediately after operation, 10 to 20% of patients showed better or deteriorated results in neuropsychological examinations, which recovered in all patients after one year. Postoperative seizures were absent in three fourths of patients. Further efforts are needed to obtain better seizure control in future.

Adolescent↗

[Assessment of intra and extrahepatic perfusion during hepatic artery infusion chemotherapy using slow-injected gadolinium-enhanced MR imaging through implanted catheter-port-system].

Twenty-four studies of intra-arterially slow-injected gadolinium-enhanced MR imaging through an implanted catheter-port system (reservoir-MR) were carried out in 15 patients with liver tumor. The flow rate of gadolinium injection was 0.1 ml/sec and a total of 3 mL was injected. Six consecutive phases, each with an acquisition time of 14 seconds, were obtained every 30 seconds. In all studies, the signal intensity of the drug delivery portion became very high. Twenty-three of 24 studies showed intrahepatic perfusion in the first phase. The hepatic vein was enhanced at the first phase in 10 and the second phase in 14. The abdominal aorta was enhanced at the second phase in all 24 studies. The portal vein was enhanced at the first phase in 4, the second phase in 13, and the third phase in 7 studies. Both intra- and extrahepatic perfusion were more clearly demonstrated by reservoir-MRI than by digital subtraction angiography through an implanted catheter-port system (reservoir-DSA); however, morphological changes in the hepatic artery were better demonstrated by reservoir-DSA than by reservoir-MRI.

Adult↗

Divergent natriuretic action of calcium channel antagonists in mongrel dogs: renal haemodynamics as a determinant of natriuresis.

This study examined the effects of different types of calcium channel antagonists on renal haemodynamics and natriuresis. The intravenous infusion of nifedipine (L-type blocker), efonidipine (L/T-type blocker) or mibefradil (predominant T-type blocker) into anaesthetized dogs elicited similar, albeit modest, reductions in blood pressure. Nifedipine (1 microgram.min(-1).kg(-1)) increased renal plasma flow (RPF) (23+/-6%; P<0.05) and glomerular filtration rate (GFR) (25+/-5%; P<0.05) (all values are means+/-S.E.M., n=7). Efonidipine (0.33 microgram .min(-1).kg(-1)) also elevated RPF (18+/-6%; P<0.05), and tended to increase GFR (17+/-8%; P=0.08). These antagonists exerted contrasting actions on the filtration fraction (FF), with an increase being elicited by nifedipine, whereas efonidipine had no effect. Furthermore, mibefradil (0.01-1 microgram.min(-1).kg(-1)) slightly elevated RPF (between 5+/-3% and 8+/-3%), but failed to alter GFR, resulting in a decrease in FF. Nifedipine slightly increased urinary sodium excretion (U(Na)V) (29+/-16% increase at 1 microgram .min(-1).kg(-1)) and fractional sodium excretion (FE(Na)) (18+/-14%), whereas efonidipine (0.33 microgram .min(-1).kg(-1)) elicited marked elevations in U(Na)V (110+/-38%; P<0.05) and FE(Na) (102+/-44%; P<0.05). Mibefradil (1 microgram .min(-1).kg(-1)) exerted a moderate natriuretic action [U(Na)V, +60+/-32% (P=0.1); FE(Na), +67+/-20% (P<0.05)]. Furthermore, although a positive correlation was observed between U(Na)V and urinary nitrate/nitrite excretion, no differences were noted between the various calcium channel antagonists. Collectively, this study demonstrates that the glomerular haemodynamic and natriuretic actions of these calcium channel antagonists, which possess diverse blocking activities on L/T-type channels, vary. Based on the divergent actions on FF (i.e. increase, no change and decrease by nifedipine, efonidipine and mibefradil respectively), the natriuretic action of calcium channel antagonists is possibly attributed to the inhibition of tubular sodium reabsorption associated with increased post-glomerular blood flow, rather than increased GFR.

Animals↗

[Assessment of intraperitoneal drug distribution during intraperitoneal chemotherapy using saline-injected MR imaging through an implanted catheter-port system].

Intraperitoneal saline-injected MR imaging through an implanted catheter-port system (saline-MRI) was conducted in 7 patients with ovarian tumor after surgical removal of the primary tumor. Two types of T2 weighted coronal images of the abdomen were obtained after saline injection through the implanted catheter-port system. One uses long TE (about 1000 msec) with fat-saturation and thick slices (100 mm thickness) to depict the injected saline alone. The other uses medium TE (about 100 msec) without fat-saturation and thin slices (10 mm thickness) to depict both intraperitoneal saline and abdominal structures. Saline sequentially fills the Douglas pouch, paracolic gutter, Morison's pouch and subphrenic space in most patients. The relation between injected saline and abdominal structures was seen well on T2-weighted images using medium TE. Adhesions of the peritoneum were well demonstrated. In one patient, a catheter perforation to the bowel loop was diagnosed, because the small bowel loop was immediately filled with injected saline. Saline-MRI can be used to depict intraperitoneal drug distribution during intraperitoneal chemotherapy and can diagnose complications related to intraperitoneal chemotherapy.

Adolescent↗

Prolonged herpes zoster in a patient infected with the human immunodeficiency virus.

In 1983, varicella zoster virus (VZV) disease was first recognized in the context of infection with the human immunodeficiency virus (HIV). Since that time, there have been many reports discussing the occurrence and clinical manifestations of hepes zoster in HIV-infected patients. We describe the development of prolonged herpes zoster in a patient with acquired immunodeficiency syndrome (AIDS) over the course of 104 days. Viral isolates at the three different clinical stages of the skin lesions were sensitive in vitro to acyclovir, and supposed to be a same strain by polymerase chain reaction (PCR) analysis. We also discuss an effective treatment for prolonged cases of zoster.

AIDS-Related Opportunistic Infections↗

[Clinical analysis of the mechanism of oculomotor nerve palsy caused by unruptured internal carotid artery posterior communicating artery aneurysm].

We analyzed the clinical course of eight female patients of oculomotor nerve palsy due to unruptured internal artery posterior (IC-PC) communicating artery aneurysm in order to speculate on the mechanism of aneurysmal rupture. Seven of the eight patients had preceding headache or ophthalmalgia, three of them deteriorated oculomotor nerve palsy and one showed worsening of ophthalmalgia. These deteriorations occurred between three to seven days after the first clinical symptom appeared. Neck clipping of aneurysm was performed for all eight patients. These aneurysms were profiled except for one patient whose aneurysm ruptured before operation. None of these seven patients had subarachnoid hemorrhage in the operative field. The patients who showed clinical deterioration had fragile aneurysm wall, wall with bleb, and one aneurysm showed minor blood leakage during operative manipulation. In the four patients who did not show clinical deterioration, aneurysm attached oculomotor nerve, these aneurysm walls were arteriosclerotic and we could not find the fragile portion during operation. Repeated minor bleeding near the oculomotor nerve or direct aneurysmal compression are the main causes of oculomotor nerve palsy with unruptured IC-PC aneurysm. Adhesion or stimulation of aneurysm on the upper border of cavernous sinus cause the headache or ophthalmalgia and these deteriorations are thought to occur gradually. However, these deteriorations occur more rapidly than ever thought and reflect acute aneurysmal growth and its direct affect on the oculomotor nerve. IC-PC aneurysm is the only aneurysm we can observe its aneurysmal growth by its unique clinical presentation. From this study, we conclude that the deterioration of oculomotor nerve palsy, preceding headache or ophthalmalgia reflects rapid growth of unruptured IC-PC aneurysm. We neurosurgeons consider it to be an urgent rupture period and should introduce surgical management to prevent its rupture and the devastating consequence of subarachnoid hemorrhage.

Aged↗

Comparisons of psychosomatic health and unhealthy behaviors between cleanroom workers in a 12-hour shift and those in an 8-hour shift.

The General Health Questionnaire (GHQ12) and physical fitness tests were administered to 338 workers in clean rooms producing electronic parts in 12-h shifts. The results were compared to those in 95 workers in 8-h shifts and 284 daytime management, clerical and engineering workers. The 12-h shift workers complained of poor health, dissatisfaction with life and poor recuperation from fatigue more than the 8-h shift workers although the rates of complaints were highest in the daytime workers. The GHQ scores were similar in the two shift groups, and much better than those in the daytime workers. However, the 12-h shift workers showed significantly lower fitness levels than the 8-h shift workers, and the levels were even worse than the daytime workers who had higher mean age and BMI levels compared with the shift workers. The tendency to have sedentary freetime activities and larger alcohol and cigarette consumption were observed in the 12-h shift workers. The 12-h shift work may have contributed to the unhealthy behaviors resulting in lower physical fitness levels. Health promotion services at the workplace should devote greater attention to long-hour shift workers, together with devising the ways to improve working conditions and environments for reducing fatigue at work.

Adult↗

Psychophysiological correlates of social skills deficits in persons with schizophrenia.

Social skill deficits in schizophrenia profoundly affect patients' life-long outcome, although the profile of the underlying cognitive dysfunction still remains a matter of debate. In the present study, we investigated the relationship between social skills and event-related potentials (ERPs) in an auditory selective attention task, in addition to the neurocognitive indices obtained from the degraded-stimulus continuous performance test (CPT) and clinical indices, such as Brief Psychiatric Rating Scale (BRPS) and global assessment of function (GAF) scores. Social skills were assessed using a Japanese version of the structured role play test. Fourteen persons with schizophrenia participated in the study. Non-verbal skills showed a positive correlation with GAF, the performance level, N1 and N2b amplitude in the ERP task, and hit rate in the CPT, and a negative correlation with reaction time in the CPT. Verbal communication skills showed a positive correlation with GAF, the performance level and N2b amplitude in the ERP task, and hit rate in the CPT, and a negative correlation with reaction time in the CPT. Processing skills showed a positive correlation with the performance level and N1 amplitude in the ERP task and a negative correlation with reaction time in the CPT. These findings suggested that the social skill deficits of persons with schizophrenia were related to the vigilance level and controlled stimulus detection processing.

Adult↗

Complementary DNA structure and genomic organization of Drosophila menin.

Menin is a protein product of a tumor supressor gene MEN1, mutations of which are responsible for multiple endocrine neoplasia type 1, an autosomal dominant familial cancer syndrome. We determined the nucleotide sequence of the Drosophila menin cDNA using RT-PCR and RACE, and confirmed it by direct sequencing of genomic DNA. Gene expression of Drosophila menin was detected by Northern blot analysis in adult and embryo as two types of transcripts, one identical in size to the cDNA, and the other larger but detected only in embryo. The Drosophila menin gene was composed of five exons in which the protein was encoded in exon 2 through 5, and spanned approximately 6.3 kb. The deduced amino acid (AA) sequence of Drosophila menin consisted of 751 AAs with a calculated molecular mass of 81.7 kDa, and showed 44-47% identity to human, rat, mouse and zebrafish menin over the entire length. Among the AA residue substitutions that have been reported as disease-associated missense mutations and single AA deletions, 53 out of 71 were completely conserved in Drosophila. The presence of menin ortholog in insect indicates that menin is an evolutionally conserved protein with a fundamental role in biological processes.

Amino Acid Sequence↗

Expectation of pain enhances responses to nonpainful somatosensory stimulation in the anterior cingulate cortex and parietal operculum/posterior insula: an event-related functional magnetic resonance imaging study.

Although behavioral studies suggest that pain distress may alter the perception of somatic stimulation, neural correlates underlying such alteration remain to be clarified. The present study was aimed to test the hypothesis that expectation of pain might amplify brain responses to somatosensory stimulation in the anterior cingulate cortex (ACC) and the region including parietal operculum and posterior insula (PO/PI), both of which may play roles in regulating pain-dependent behavior. We compared brain responses with and subjective evaluation of physically identical nonpainful warm stimuli between two psychologically different contexts: one linked with pain expectation by presenting the nonpainful stimuli randomly intermixed with painful stimuli and the other without. By applying the event-related functional magnetic resonance imaging technique, brain responses to the stimuli were assessed with respect to signal changes and activated volume, setting regions of interest on activated clusters in ACC and bilateral PO/PI defined by painful stimuli. As a result, the uncertain expectation of painful stimulus enhanced transient brain responses to nonpainful stimulus in ACC and PO/PI. The enhanced responses were revealed as a higher intensity of signal change in ACC and larger volume of activated voxels in PO/PI. Behavioral measurements demonstrated that expectation of painful stimulus amplified perceived unpleasantness of innocuous stimulus. From these findings, it is suggested that ACC and PO/PI are involved in modulation of affective aspect of sensory perception by the uncertain expectation of painful stimulus.

Adult↗

Attentional modulation of parieto-occipital cortical responses: implications for hemispatial neglect.

Functional magnetic resonance imaging (fMRI) was used to examine whether preattentive and attentive visual processing, the cognitive psychological dichotomy on normal vision, indeed activate the parieto-occipital systems differentially as suggested by recent neuropsychological research. The activation paradigms consisted of feature detection and discrimination of line orientation, and visual fixation, which corresponded to preattentive, attention-requiring, and baseline conditions, respectively. The detection versus fixation contrast revealed activation sites in the right lateral prefrontal cortex and bilateral occipital lobes, whereas the discrimination versus fixation contrast showed broader bilateral activations extending from the occipital lobes through the parietal lobes, prefrontal cortex, thalamus, basal ganglia and upper brainstem. In the discrimination versus detection contrast, significant activations were observed in the right superior and inferior parietal lobules as well as in the subcortical structures. These findings were consistently demonstrated both at intra- and inter-subject levels. The present study provides further evidence to delineate neural substrate for the two distinct modes of visual processing and helps us to understand the neuropsychological mechanism underlying visual attention disorders.

Adult↗

Linkage of human narcolepsy with HLA association to chromosome 4p13-q21.

Although narcolepsy is highly associated with human leukocyte antigen (HLA) DQ6/DQB1*0602 and/or DR2/DRB1*1501, most individuals with the HLA haplotype are free of narcolepsy. This indicates that HLA alone makes a relatively small contribution to the development of narcolepsy and that a non-HLA gene(s) can contribute to the genetic predisposition even in narcoleptic cases with HLA association. We conducted a genome-wide linkage search for narcolepsy in eight Japanese families with 21 DR2-positive patients (14 narcoleptic cases with cataplexy and 7 cases with an incomplete form of narcolepsy). A lod score of 3.09 suggested linkage to chromosome 4p13-q21. A lod score of 1.53 was obtained at the HLA-DRB1 locus, though this lod score may be biased since all the affected patients and many of the family members were DR2-positive. No other loci including hypocretin, hypocretin receptor 1, and hypocretin receptor 2 had lod scores greater than 1.0. The present study suggests that chromosome 4p13-q21 contains a second locus for HLA-associated human narcolepsy.

Chromosome Mapping↗