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Biomedical subjects

Hideki Tanaka

Publications and source records attributed to Hideki Tanaka.

52 records · Page 3Linked to original sources
PubMed2003

Immunocytochemical applications of specific antisera raised against synthetic fragment peptides of mummichog GtH subunits: examining seasonal variations of gonadotrophs (FSH cells and LH cells) in the mummichog and applications to other acanthopterygian fishes.

Two distinct types of gonadotrophs, FSH (GtH I) cells and LH (GtH II) cells, were immunocytochemically identified from mummichog (Fundulus heteroclitus; Cyprinodontiformes, Acanthopterygii) pituitary using antisera raised against synthetic fragment peptides of FSHbeta and LHbeta. Both cell types were abundant during the spawning period (spring and early summer) and decreased in number during the post-spawning immature period. The number of FSH cells increased again during the early phases of gonadal development (cortical alveoli accumulation in the oocytes and basal spermatogenesis) in early winter, whereas the number of LH cells did not. Only FSH cells were abundant during the latter phases of gonadal development (vitellogenesis and active spermatogenesis) in early spring. These observations suggest that both GtHs have important yet different roles for reproduction in this species. Antisera against the conservative region of the FSHbeta and the LHbeta subunits immunostained FSH cells and LH cells, respectively, also in red seabream (Pagrus major; Perciformes, Acanthopterygii) and small mouth bass (Micropterus dolomieu; Perciformes, Acanthopterygii), suggesting the possibility of their use for other acanthopterygian fishes.

Animals↗
PubMed2003

Significance of consecutive bilateral surgeries for patients with acute subdural hematoma who develop contralateral acute epi- or subdural hematoma.

BACKGROUND: Although rare, patients with acute subdural hematoma (ASDH) because of severe head injury can develop contralateral acute epi- or subdural hematoma, requiring consecutive surgical procedures. The choice of treatment strategies for such patients is clinically important. METHODS: Among 88 patients with ASDH who were surgically treated over 13 years, we encountered and studied 5 patients who developed contralateral acute epi- or subdural hematoma (5.7%). RESULTS: All 5 patients were male, ranging in age from 17 to 40. According to the Glasgow Coma Scale on admission, 1 patient was rated 3, 1 was 4, 1 was 5, and 2 were 6. All patients underwent consecutive surgical procedures for ASDH and contralateral ASDH and/or acute epidural hematoma, and were given postoperative supportive therapy with barbiturates and mild hypothermia. Patients' outcomes according to the Glasgow Outcome Scale were as follows: 1 patient, good recovery (20.0%); 1, mild disability (20.0%); 2, severe disability (40.0%), and 1, persistent vegetative state (20.0%). No patients died. Although decompressive craniectomy and evacuation of hematoma may lead to contralateral acute epi- or subdural hematoma in patients with ASDH, this therapy is justified because hematoma irrigation with trephination therapy has a poor outcome for comatose patients. CONCLUSION: Awareness of intraoperative brain swelling is important, as it suggests the development of contralateral hematoma. Immediate computed tomography and a rapid return to the operating room are therefore critical.

Adolescent↗
PubMed2003

Analysis of loci required for determination of serotype antigenicity in Streptococcus mutans and its clinical utilization.

We recently identified the genes responsible for the serotype c-specific glucose side chain formation of rhamnose-glucose polysaccharide (RGP) in Streptococcus mutans. These genes were located downstream from the rgpA through rgpF locus that is involved in the synthesis of RGP. In the present study, the corresponding chromosomal regions were isolated from serotype e and f strains and characterized. The rgpA through rgpF homologs were well conserved among the three serotypes. By contrast, the regions downstream from the rgpF homolog differed considerably among the three serotypes. Replacement of these regions in the different serotype strains converted their serotypic phenotypes, suggesting that these regions participated in serotype-specific glucose side chain formation in each serotype strain. Based on the differences among the DNA sequences of these regions, a PCR method was developed to determine serotypes. S. mutans was isolated from 198 of 432 preschool children (3 to 4 years old). The serotypes of all but one S. mutans isolate were identified by serotyping PCR. Serotype c predominated (84.8%), serotype e was the next most common (13.3%), and serotype f occured rarely (1.9%) in Japanese preschool children. Caries experience in the group with a mixed infection by multiple serotypes of S. mutans was significantly higher than that in the group with a monoinfection by a single serotype.

Child, Preschool↗
PubMed2003

Sodium iodoacetate-induced experimental osteoarthritis and associated pain model in rats.

Degenerative lesions were induced in the knee joint of Wistar rats by intraarticular injection of chondrocyte metabolism inhibitor mono-iodoacetate (MIA) at doses of 0, 0.3 or 3 mg/joint. Histopathological examination and the measurement of hind paw weight ratio as an index of joint pain by incapacitance tester were performed. Histological findings that are similar to those observed in human osteoarthritis (OA), such as disorganization of chondrocytes, erosion and fibrillation of cartilage surface, and subchondral bone exposure etc., were observed in a MIA-dose-dependent manner. Saflanin-O fast green staining revealed that marked diffuse reduction of proteoglycan in cartilage tissue of rats treated with MIA. The clinical scores of the joint pain were closely correlated to the grade of histological findings. We conclude that the present experimental model in combination with a novel dual channel weight averager would be very useful for the study of human OA, and could be applied for estimation of therapeutic effect of new anti-OA drugs.

Animals↗
PubMed2003

Electro-acupuncture stimulation effects on duodenal motility in anesthetized rats.

The effect of electro-acupuncture stimulation (EAS) on duodenal motility was examined in anesthetized, artificially ventilated rats. EAS was applied to the abdominal area or to a hindpaw for 30 s at stimulus intensities of 0.1-10.0 mA with a stimulus frequency of 20 Hz. The duodenal motility was measured using the balloon method at a position about 1.5 cm caudal from the pylorus. Duodenal motility was inhibited by EAS at intensities of more than 5.0 mA (suprathreshold of group IV afferent excitation) when applied to the abdominal area. The duodenal inhibitory response existed after bilateral vagotomy or spinal transection, but was abolished by sectioning bilateral splanchnic nerves. Duodenal motility was facilitated by EAS at intensities of more than 2.0 mA (subthreshold of group IV, and suprathreshold for groups II+III afferent excitation) when applied to a hindpaw. The duodenal facilitatory response by EAS to a hindpaw existed after sectioning the splanchnic nerves, but disappeared after bilateral vagotomy or spinal transection. Furthermore, repetitive electrical stimulation of vagal efferent nerves enhanced duodenal motility, while repetitive electrical stimulation of the splanchnic efferent nerves inhibited the motility. It was concluded that the inhibitory response of duodenal motility elicited by EAS to the abdominal area is a spinal reflex response involving splanchnic inhibitory efferent nerves, and the enhanced response of duodenal motility by EAS to a hindpaw is a supraspinal reflex response involving vagal excitatory nerves.

Abdomen↗
PubMed2003

[Construction of a standard rating scale to estimate sleep onset and the analysis of influencing factors].

In this study, we developed a ratings scale for estimating sleep onset that would be capable of providing quantitative evaluations of the quality of the sleep onset process. We also examined factors affecting sleep onset using a questionnaire consisting of two separate clusters of items: the first, consisting of 9 items, related to the quality of sleep onset; and the second, consisting of 56 items, related to factors with apparent effects on sleep onset. The questionnaire was administered to 515 day-workers (range: 25-44 years old) for standardization. Each item was weighted based on the distribution of subject responses to determine discrimination. The reliability coefficient alpha for the questionnaire was high, exceeding 0.8. Of 41 items set out as potential factors affecting sleep onset, the results of the questionnaire indicated that five factors consisting of 26 items could be isolated as most likely affecting sleep onset. Path analysis indicated that sleep onset is more commonly affected by factors present at bedtime than factors related to sleep quality the previous night, or to daytime activities.

Adult↗
PubMed2002

Effects of luteinizing hormone and follicle-stimulating hormone and insulin-like growth factor-I on aromatase activity and P450 aromatase gene expression in the ovarian follicles of red seabream, Pagrus major.

To clarify the mechanism of estradiol-17beta production in the ovarian follicle of red seabream, in vitro effects of luteinizing hormone (LH), follicle-stimulating hormone (FSH), and insulin-like growth factor (IGF-I) on aromatase activity (conversion of testosterone to estradiol-17beta) and cytochrome P450 aromatase (P450arom) mRNA expression in ovarian fragments of red seabream were investigated. Of the growth factors used in the present study, only IGF-I stimulated both aromatase activity and P450arom gene expression in the ovarian fragments of red seabream. LH from red seabream pituitary, but not FSH, stimulated both aromatase activity and P450arom gene expression. IGF-I slightly enhanced the LH-induced aromatase activity and P450arom gene expression. These data and our previous results indicate that LH, but not FSH, stimulates estradiol-17beta production in the ovarian follicle of red seabream through stimulation of aromatase activity and P450arom gene expression and IGF-I enhances the LH-stimulated P450arom gene expression.

Animals↗
PubMed2002

On the Debye-Waller factor of hexagonal ice: a computer simulation study.

We investigate by molecular dynamics (MD) simulations the temperature dependence of the Debye-Waller (DW) factor of hexagonal ice with 25 different proton-disordered configurations. Each initial configuration is composed of 288 water molecules with no net dipole moment. The intermolecular interaction of water is described by TIP4P potential. Each production run of the simulation is 15 ns or longer. We observe a change in slope of the DW factor around 200 K, which cannot be explained within the framework of either classical or quantum harmonic approximation. Configurations generated by MD simulations are subjected to the steepest descent energy minimization. Analysis of the local energy minimum structures reveals that water molecules above 200 K jump to other lattice sites via some local energy minimum structures which contain some water molecules sitting on the locations other than the lattice sites. As time evolves, these defect molecules move back and forth to the lattice sites yielding defect-free structures. Those motions are responsible for the unusual increase in the DW factor at high temperatures. In making a transition from an energy-minimum structure to another one, a small number of water molecules are involved in a highly cooperative fashion. The larger DW factor at higher temperature arises from jump-like motions of water molecules among these locally stable configurations which may or may not be a family of the proton-disordered ice forms satisfying the "ice rule".

Computer Simulation↗
PubMed2002

Prognostic significance of early diagnosis in acute pulmonary thromboembolism with circulatory failure.

Despite the advances in our understanding of venous thromboembolic disease, the prevalence of pulmonary thromboembolism (PTE) at autopsy has not changed over 3 decades. When patients survive long enough to have a diagnosis of massive PTE and start receiving treatment, the outlook is considered to be moderately good. However, the diagnosis is often difficult to obtain and is frequently missed. We hypothesize that mortality of acute PTE is reduced by early diagnosis. Eighty-five patients with acute PTE with circulatory failure who survived 1 h after the onset were divided into two groups: the early Dx group consisted of the patients whose disease was diagnosed as acute PTE within 24 h of the onset, and the Late Dx group included patients whose disease was not diagnosed within 24 h of onset, or died without clinical diagnosis between 1 and 24 h after the onset. Overall mortality was significantly low in the Early Dx group compared with that of the Late Dx group (21.6% vs 67.6%, P < 0.0001). Multiple logistic regression analysis demonstrated that a reduction in in-hospital mortality was associated with early diagnosis (odds ratio for in-hospital death, 0.094; 95% confidence interval, 0.03-0.33). The results of our study suggested that early diagnosis might favorably affect the in-hospital clinical outcome of hemodynamically unstable patients with acute PTE.

Adolescent↗
PubMed2002

Short naps and exercise improve sleep quality and mental health in the elderly.

The effects of short naps and exercise on the sleep quality and mental health of elderly people was investigated. 'Interventions' by short naps after lunch and exercise of moderate intensity in the evening were carried out for 4 weeks. After the 'intervention', awake time after sleep onset decreased significantly and sleep efficiency increased significantly, demonstrating that sleep quality had improved. Also, the frequency of nodding in the evening decreased significantly. These results demonstrate that proper awakening maintenance in the evening was effective in improving sleep quality. After the 'intervention', mental health and volition and physical health had also improved with improving sleep quality.

Aged↗
PubMed2002

An examination of sleep health, lifestyle and mental health in junior high school students.

The factors that influence sleep health and mental health in junior high school students' lifestyles was examined. The proportion of students who replied that they feel bad in the morning, and who do not have breakfast was significantly higher in poor sleepers. The proportion of students who regularly take exercise was significantly lower among poor sleepers. Compared with good sleepers, poor sleepers had a higher number of illnesses and their General Health Questionnaire score was worse. The study's results suggest that sleep health is closely related to both physical and mental health, and that habits such as exercise, and regular sleeping and eating, are important for maintaining and improving students' sleep health.

Adolescent↗
PubMed2002

Sleep health and lifestyle of elderly people in Ogimi, a village of longevity.

The study was conducted in the Prefecture of Longevity, Okinawa, on the elderly living in the village of Ogimi. It was revealed that those in the good sleep health group took short naps, a significantly fewer number fell into dozes, and a significantly greater number exercised regularly or walked. A significantly greater number of this group maintained regular eating habits over a 10-year span, and consumed more seaweed and fish. Participation in senior citizens' clubs was higher, reflecting high emotional adaptability. The study's results indicates a relationship between lifestyle and sleep health among the elderly, and suggest that deterioration of sleep health is related to physical and mental health.

Aged↗
PubMed2002

Comparative study on sleep health and lifestyle of the elderly in the urban areas and suburbs of Okinawa.

The sleep health and lifestyles of the elderly living in the urban and suburban areas of Okinawa prefecture, which is well known for the longevity of its inhabitants, were compared. The study revealed that sleep health and activities of daily living (ADL) were significantly better among the elderly living in suburban areas. There were more complaints of sleep problems from the elderly living in urban areas and their bedtimes were significantly later, indicating that a nocturnal lifestyle was related to sleep deterioration. In the suburbs, a significantly greater number of elderly people regularly took short naps and exercised in the evening. The study also suggested that daily habits such as short naps and taking appropriate exercise in the evenings contributed to good sleep, and that sleep health was related to the ADL of the elderly.

Aged↗
PubMed2002

Volitional lifestyle in healthy elderly: its relevance to rest-activity cycle, nocturnal sleep, and daytime napping.

Sleep-related problems are prevalent among the aged. The present study examined the influence of a mentally active or "volitional" lifestyle on the rest-activity cycle, nocturnal sleep, and daytime napping in the healthy elderly. 14 aged individuals with a high Volitional lifestyle (M = 74.1 yr. old) and 14 with a Low Volitional lifestyle (M = 73.0 yr. old) were screened by questionnaires including the Philadelphia Geriatric Center Morale scale and the Self-confidence scale. Their activity levels were monitored by a wrist actigraph system for 14 consecutive days. They were also asked to record daily sleep logs. The total times of nocturnal sleep and daytime napping did not differ between the groups. However, the acrophases of circadian (tau = 24 hr.) and circasemidian (tau = 12 hr.) activity cycles were more advanced in the Low Volitional group. In addition, the High Volitional group took a daytime nap with a better timing than did the Low Volitional group: the former started a nap during the phase in which their activity level was going down, whereas the latter when their activity level was going up. These results suggest that high volitional lifestyle may be related to better rest-activity cycle in the healthy elderly.

Aged↗
PubMed2002

[Malignant lymphoma with various cardiac manifestations: a case report].

A 49-year-old woman presented with malignant lymphoma manifesting as dyspnea, palpitation and leg edema. Chest radiography demonstrated cardiomegaly, electrocardiography(ECG) showed first degree atrioventricular block, and echocardiography showed concentric left ventricular hypertrophy with granular sparkling texture and mild pericardial effusion. The diagnosis was malignant lymphoma(B-cell) based on lymph node biopsy. Chemotherapy(CHOP) was performed under a suspected diagnosis of cardiac invasion of malignant lymphoma. Immediately after chemotherapy, ECG showed complete atrioventricular block with sinus arrest, ventricular fibrillation and atrial fibrillation. ECG was normalized after 2 weeks on chemotherapy. Left ventricular hypertrophy was improved and pericardial effusion disappeared. However, she died of recurrence of malignant lymphoma on day 116.

Antineoplastic Combined Chemotherapy Protocols↗