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Biomedical subjects

K Otake

Publications and source records attributed to K Otake.

At least 19 recordsLinked to original sources
PubMed2003

Forebrain neurons with collateral projections to both the interstitial nucleus of the posterior limb of the anterior commissure and the nucleus of the solitary tract in the rat.

The interstitial nucleus of the posterior limb of the anterior commissure (IPAC) receives inputs from several autonomic/limbic regions in the forebrain, including the agranular insular cortex, bed nucleus of the stria terminalis, the amygdaloid complex, and the lateral hypothalamic area. We sought to identify the distribution of afferent sources to the IPAC and to determine whether these IPAC projection fibers issue collaterals to the nucleus of the solitary tract (NTS), the principal relay of primary visceral afferents. Two fluorescent tracers, FluoroGold and FluoroRed, were centered stereotaxically on the IPAC and the NTS on chloral hydrate-anesthetized Sprague-Dawley rats. Although the majority of IPAC and NTS afferents were spatially segregated, small but substantial numbers of dually labeled neurons (three to four cells/section) were observed in the dorsal bank of the posterior agranular insular cortex, exclusively in layer V. Collateral projection neurons were also found in the posterior part of the lateral hypothalamic area (two to six cells/section). The branching projections identified here may represent a potential link between affective or motivated behavior and viscerosensory processing.

Amygdala↗
PubMed2003

Urinary excretion of aquaporin-2 and inappropriate secretion of vasopressin in hyponatremic patients after cerebral infarction.

Aquaporin-2, a water-channel protein, is known to increase water permeability due to vasopressin binding to V2 receptors at the renal collecting duct and is excreted into the urine. It is still unclear whether a hyponatremic state is caused by vasopressin-dependent aquaporin-2 in patients clinically diagnosed with the syndrome of inappropriate secretion of antidiuretic hormone. To determine this, we measured urinary aquaporin-2 and vasopressin by radioimmunoassay in normonatremic or hyponatremic patients after cerebral infarction and in healthy controls. In the normonatremia group, urinary aquaporin-2 and plasma AVP levels were higher than in controls. In the hyponatremia group, plasma AVP was relatively high despite low plasma osmolality in each patient. However, urinary aquaporin-2 in hyponatremia was significantly increased when compared with the other two groups. In conclusion, AQP-2 increment does not directly reflect non-osmotic AVP secretion in a hyponatremic state. This result indicates that the urinary excretion of AQP-2 is not only AVP-dependent in hyponatremic states.

Aged↗
PubMed2002

Cardiovascular medication use in patients with undiagnosed obstructive sleep apnoea.

BACKGROUND: A study was undertaken in patients with undiagnosed sleep apnoea/hypopnoea syndrome (OSAS) to document the use of prescribed medications, especially those used in cardiovascular diseases, in the year before the OSAS diagnosis was confirmed. METHODS: A total of 549 patients with OSAS (401 men of mean age 47.2 years, mean body mass index (BMI) 35.5 kg/m(2), mean apnoea/hypopnoea index (AHI) 47.2 and148 women of mean age 50.2 years, BMI 39.6 kg/m(2), AHI 32.6) were each matched to one general population control by age, sex, geographical location, and family physician. Medication use was evaluated for patients and controls using a database containing information about all prescriptions completed in the province of Manitoba, Canada. RESULTS: In the year before OSAS was diagnosed, prescribed medication costs were $155.91 (Canadian dollars) (95% CI $91.34 to $220.49) greater for cases than for controls. Cases were dispensed 3.3 (95% CI 1.5 to 5.2) more prescriptions, were on 1.2 (95% CI 0.8 to 1.6) more medications, and were supplied with 157.4 (95% CI 95.9 to 218.8) more daily doses of medication. The odds ratio of OSAS cases being on a prescribed medication was 1.88 relative to controls (95% CI 1.38 to 2.54, p<0.0001). In the same year 36.6% of cases and 19.7% of controls were using medications for cardiovascular disease (OR 2.82, 95% CI 2.05 to 3.89, p<0.0001), consuming 79.4 (95% CI 48.9 to 109.8) more daily doses of medication, having been dispensed 1.7 (95% CI 1.0 to 2.4) more prescriptions, and at a $75.26 (95% CI $44.03 to $106.50) greater cost. The odds ratio of patients with OSAS being on medications indicated for the treatment of systemic hypertension was 2.71 (95% CI 1.96 to 3.77) relative to controls; however, such medications might also be prescribed for other indications such as angina pectoris and congestive heart failure, and for the secondary prevention of myocardial infarction. The use of medications indicated for the treatment of systemic hypertension was predicted significantly by age (odds ratio (OR) 1.10 per year), BMI (OR 1.05 per unit), and AHI (OR 1.01 per unit). CONCLUSIONS: In the year before OSAS was diagnosed, patients with OSAS were heavy users of medications, particularly those used to treat cardiovascular diseases.

Body Mass Index↗
PubMed2001

Alveolar macrophage deficiency in osteopetrotic mice deficient in macrophage colony-stimulating factor is spontaneously corrected with age and associated with matrix metalloproteinase expression and emphysema.

Macrophage colony-stimulating factor (M-CSF) is one of several hematologic growth factors capable of regulating the survival, proliferation, and differentiation of macrophages, but its role in modulation of the accumulation and function of alveolar macrophages (AMs) in vivo is not well defined. Osteopetrotic (Op/Op) mice have no detectable M-CSF and show variable tissue-specific reductions in macrophage numbers. It was hypothesized that AMs would be decreased in number and have altered function in Op/Op mice because of the absence of M-CSF. Lung macrophages identified by Mac-3 staining in lung sections were decreased in number in 20-day-old Op/Op mice (P <.001) but not Op/Op mice older than 4 months (P =.68) compared with findings in age-matched littermate controls. The numbers of AMs recovered by bronchoalveolar lavage (BAL) were also reduced in young but not adult Op/Op mice compared with controls. Expression of interleukin-3 (IL-3) was increased in the lungs of Op/Op mice compared with controls as determined by quantification of IL-3 cytokine levels (P =.04), bioactivity (P =.02), and messenger RNA transcript levels. AMs of Op/Op mice spontaneously released higher levels of matrix metalloproteinases (MMPs) than AMs of controls as determined by immunohistochemical staining of AMs and zymographic assessment of BAL fluid and AM lysates. Consistent with an increased release of MMP, Op/Op mice had abnormal elastin deposition and spontaneously developed emphysema in the absence of molecular or cellular evidence of lung inflammation. These data show that the AM deficiency observed in young Op/Op mice is spontaneously corrected with age and is associated with increased lung levels of IL-3, spontaneous MMP expression by AMs, and destruction of lung tissue.

Age Factors↗
PubMed2001

Functional recovery and regeneration of descending tracts in rats after spinal cord transection in infancy.

STUDY DESIGN: The functional recovery of rats that underwent spinal cord transection in infancy was evaluated by multimodal examination (functional tests, electrophysiologic evaluation, tract-tracing) to determine the basis for the recovery. OBJECTIVES: To determine whether the hind limb function in rats that underwent spinal cord transection in infancy is regained completely, which descending tracts regenerate after the transection, and whether the functional recovery is correlated with axonal reconnection. SUMMARY OF BACKGROUND DATA: It is widely accepted that a newborn rat recovers its hind limb function after spinal cord transection even without any specific treatments. This functional recovery might be attributed to possible regeneration of some descending pathways, although there is a counterargument that well-trained spinal cord reflexes may bring about functional compensation. METHODS: The thoracic spinal cord of infant rats was completely transected at Th10 when they were 2 weeks of age. Multimodal functional tests and electrophysiologic studies were performed 5 weeks later. Some recovered rats (i.e., those able to walk after the transection) underwent spinal cord retransection, with subsequent reevaluation of locomotion and muscle-evoked potentials. At 6 weeks after the initial transection, tract-tracing studies were performed in some animals. RESULTS: A motor performance score detected the functional differences between the control and the recovered rats. Muscle-evoked potentials of hind limbs after electrical stimulation to the brain were recorded in some of the recovered rats, but never in the unrecovered rats. Moreover, the muscle-evoked potentials of the recovered rats disappeared after spinal cord retransection that resulted in loss of voluntary movement. Morphologic studies in two rats provided evidence that reconnection of rubrospinal, vestibulospinal, and reticulospinal tracts had occurred, whereas corticospinal regeneration was not detected. CONCLUSIONS: It can be concluded that the hind limb function of rats that underwent spinal cord transection in infancy was partially regained; that axonal regeneration of the rubrospinal, vestibulospinal, or reticulospinal tracts was demonstrated, whereas the reconnection of the corticospinal tract was not observed; and that the axonal regeneration of these tracts is involved in the functional recovery.

Animals↗
PubMed2001

Reactivation of feline foamy virus from a chronically infected feline renal cell line by trichostatin A.

Although acute infection of feline foamy virus (FeFV) is normally highly cytopathogenic in Crandell feline kidney (CRFK) cells, a noncytopathic persistent infection was established in the cells after cocultivation of the initially infected cells with uninfected cells four times. To investigate reactivation of persistent infection, CRFK cells chronically infected with FeFV were treated with trichostatin A (TA), a histone deacetylase inhibitor. TA induced higher FeFV production from the Coleman strain carrier culture and also induced marked syncytium formation. In contrast, human foamy virus, which contains less homologous long terminal repeat (LTR) and putative internal promoter (IP) sequences, persistently infecting baby hamster kidney cells was not reactivated by TA. The Sammy-1 strain of FeFV, from which a part of the U3 region in the LTR is naturally deleted, showed less reactivation. The Coleman LTR promoter-based beta-Gal-expressing plasmid was activated in the persistently Coleman-infected cells in the presence of TA, whereas the Sammy-1 LTR was not activated. Furthermore, the amounts of Gag protein expressed did not change in the presence or absence of TA. Because the putative IP region was very similar between the two strains, the initiation by TA is relatively specific for LTR sequences, and, therefore, histone deacetylation is at least in part responsible for reactivation of FeFV from carrier cell culture.

Animals↗
PubMed2001

Morphology of pulmonary rapidly adapting receptor relay neurons in the rat.

The term rapidly adapting pulmonary stretch receptor (RAR) refers to one of the major pulmonary sensory receptors that responds to inflation and deflation of the lungs as well as to irritant stimuli with rapidly adapting irregular discharges. The functional role and central pathways are largely unknown. The aim of this study was to elucidate morphological characteristics of second-order neurons (RAR cells) activated by vagal afferent fibers originating from RARs. A mixture of horseradish peroxidase (HRP) and Neurobiotin was injected intracellularly into physiologically identified RAR cells in Nembutal-anesthetized, immobilized, and artificially ventilated Wister rats. Direct visualization of individual RAR cells (n = 12), including their somata, dendritic arborizations, and fine axonal branches with terminal boutons, was possible for the first time. Their somata were located in the commissural or medial subdivision of the nucleus of the solitary tract, caudal to the level of the area postrema. The RAR cells had, in addition to dendrites extending into the NTS area, one or two long dendrites extending laterally and/or ventrolaterally into the medullary reticular formation. The stem axons issuing from the RAR cells first coursed ventrolaterally toward the reticular formation in the vicinity of the ambiguus nucleus and then bifurcated into ascending and descending axons: three RAR cells possessed only ascending axons. Some of the ascending axons could be traced as far as the level of the facial nucleus and some of the descending axons beyond the spinomedullary junction. These ascending and/or descending axons gave off extensive axon collaterals distributing boutons within and in the vicinity of the ambiguus nucleus. These results, showing an anatomical substrate for the network implicated in RAR-evoked reflexes, provide useful clues for study of the RAR system.

Afferent Pathways↗
PubMed2001

Immunohistochemical localization of Ca(2+)/calmodulin-dependent protein kinase kinase beta in the rat central nervous system.

We examined regional and intracellular distribution of Ca(2+)/calmodulin-dependent protein kinase kinase beta (CaM-KK beta), which activated Ca(2+)/calmodulin-dependent protein kinase I and IV (CaM-K I and IV) immunohistochemically in the central nervous system of the rat by light and electron microscopy. Although most neurons in the brain and spinal cord exhibited the immunoreactivity, no labeled neurons were observed in the globus pallidus or entopeduncular nucleus, and only a small number of neurons showed weak immunoreactivity in the substantia nigra pars reticulata. In general, the immunoreactivity was observed both in the cytoplasm and cellular nucleus, although the immunoreactivity was not found in the cellular nucleus in some large neurons such as in the mesencephalic trigeminal nucleus, lateral vestibular nucleus or gigant cellular reticular formation. As to motoneurons of the cranial nerve nuclei and the anterior horn of the spinal cord, they revealed the immunoreactivity both in the cytoplasm and nucleus. The reaction product appeared as fine granules in the cytoplasm and nucleus under light microscopy. Electron microscopic observations confirmed that the reaction product was localized mainly on the Golgi apparatus or on the nuclear chromatin. Immunolabeling for antibody against CaM-KK beta was discussed with the distribution of CaM-K I, IV and another CaM-KK, CaM-KK alpha, in the central nervous system.

Animals↗
PubMed2001

Narcolepsy and other non-SAS hypersomnia in sleep breathing disorders clinic.

Four of the 708 snorers (0.56%), referred to our sleep breathing disorders clinic for the past 2 years were diagnosed as having narcolepsy-cataplexy. Detecting HLA DRB1*1501/DQB1*0602 positive was informative for differentiating genuine narcolepsy from non-sleep apnea syndrome (non-SAS) hypersomnia in our clinic. A non-SAS obese boy, diagnosed as having essential hypersomnia syndrome, was found to be HLA DRB1*1502/DQB1*0601 positive. His hypocretin concentration was 206 pg/mL in the cerebrospinal fluid.

Adolescent↗
PubMed2001

Effects of physiological cardiac pacing on sleep-disordered breathing in patients with chronic bradydysrhythmias.

In six patients with chronic bradydysrhythmias, polysomnographies were performed before cardiac pacemaker implantation and over the week following implantation. A patient with third-degree atrioventricular block (AVB) and two patients with sinus node dysfunction (SND) were associated with sleep-disordered breathing (SDB). Their cardiac pacemaker therapies, with the increase in the average heart rate, led to a reduction of apnea-hypopnea index and/or an improvement of Cheyne-Stokes breathing. It seems that chronic bradydysrhythmia is one of the causative factors leading to SDB.

Aged↗
PubMed2001

Binding properties of Bacillus thuringiensis Cry4A toxin to the apical microvilli of larval midgut of Culex pipiens.

Cry4A is a dipteran-specific delta-endotoxin produced by Bacillus thuringiensis, and toxic to Culex pipiens (mosquito) larvae. The immunohistochemical staining of the midgut sections of C. pipiens larvae revealed that Cry4A bound in vitro and in vivo to the microvilli of the epithelial cells of posterior midgut and gastric caecae. The binding of digoxigenin-labeled Cry4A (DIG-Cry4A) to the apical microvilli was almost abolished in the presence of excess unlabeled Cry4A, suggesting that the binding of Cry4A to the microvilli was specific. Several Cry4A-specific binding proteins were detected using the ligand blotting technique with DIG-Cry4A. Moreover, an insertion assay was done, where the binding of DIG-Cry4A to the BBMVs was completely irreversible and did not compete with excess unlabeled Cry4A. On the basis of these results, we propose a schematic interpretation for the binding process of Cry4A.

Animals↗
PubMed2001

Effects of hostility and lifestyle on coronary heart disease among middle-aged urban Japanese.

OBJECTIVE: To explore the association between multi-dimensional aspects of hostility and coronary heart disease among middle-aged urban Japanese. SUBJECTS AND METHODS: We conducted a case-control study. Cases were consecutive patients with acute coronary syndrome admitted to a hospital in Japan. Fifty-three patients (45 men and 8 women) aged 35 to 65 were enrolled. For each case, two sex and age (+/-2 years) matched controls were recruited from among participants in a health check-up program at a health promotion center located in the same area as the hospital. Two questionnaires, both with four components, were used to measure hostility and coping with anger: the one was for anger, hostility, physical aggression and verbal aggression, and the other for aggression, social inhibition, guilt, and controlled affect. RESULTS: The scores of all components from two questionnaires were higher for cases than controls, but the differences were not significant. Multivariate analysis showed that anger, fat intake, alcohol consumption and house size were significantly associated with the etiology of acute coronary syndrome. CONCLUSION: Anger, lifestyle, and socioeconomic status play important roles for the etiology of coronary heart disease in middle-aged urban Japanese.

Case-Control Studies↗
PubMed2001

Validity and reliability of the Japanese version of the Emotional Intelligence Scale among college students and psychiatric outpatients.

We examined the validity and reliability of the Japanese version of the Emotional Intelligence Scale in two samples of 267 college students and 398 psychiatric outpatients. Suitable validity and reliability of this scale were suggested by high correlations with scores on the NEO Personality Inventory, adequate internal consistency, and relatively high test-retest correlations. The Emotional Intelligence Scale seems suitable for both clinically distressed populations as well as comparative groups such as college students.

Adaptation, Psychological↗
PubMed2001

Association of emotional intelligence with alexithymic characteristics.

We examined the association of emotional intelligence and alexithymic characteristics as the personality trait in cohorts of 267 college students and 398 psychiatric outpatients. Score on the Toronto Alexithymia Scale were significantly correlated with those on the Emotional Intelligence Scale, suggesting that alexithymic characteristics are related to lower emotional intelligence. In conclusion, these data suggest that emotional intelligence overlaps with alexithymia.

Adaptation, Psychological↗
PubMed2001

Radioimmunoassay for somatostatin receptor type 2.

OBJECTIVE: To develop radioimmunoassay for somatostatin receptor type 2 (SSTR2) and search for its presence in certain rat tissues. METHODS: Anti-SSTR2 antiserum has been raised in New Zealand white rabbits immunized with a conjugate of synthetic SSTR2 with bovine serum albumin. Radioiodination of SSTR2 was performed by chloramin T method followed by purification of radioiodinated material on Sephadex G-25 column. RESULTS: The obtained antibody did not crossreact with SSTR1, SSTR3, SSTR4, SSTR5, hypothalamic hormones, pituitary hormones, neuropeptides or gut hormones. The assay was performed with a double antibody system. SSTR2 was extracted from the tissues with acid acetone. The dilution curve of acid acetone-extracts of rat hypothalamus in the radioimmunoassay system was parallel to the standard curve. The recovery of tissue SSTR2 was about 89 %, and the intra-assay and inter-assay variations were 4.9 % and 7.8 %, respectively. SSTR2 was found in the hypothalamus, cerebrum, cerebellum, pituitary, stomach and testis. CONCLUSIONS: These data suggest that this assay system is suitable for the estimation of SSTR2 in the tissues.

Acetone↗
PubMed2001

[Implication on thyroid function tests].

We tried to investigate the present problems, concerning the reference individual and interval in thyroid function tests and find the solutions for them. We are now using healthy adults for the reference individual and interval. Recently, we found the sex-difference and age-related changes for reference individual and interval in free T3 measurement. We raised the questions on whether there are any sex-differences and/or age-related changes or not. Surprisingly, there were almost no detailed data about them especially in Japan. Therefore, we examined the Europe data, and found out some kind of sex-differences and age-related changes. We propose the following examinations using many Japanese population in order to provide a precise and proper reference individual and interval: 1. Whether there are any sex-difference in thyroid function tests? 2. Whether there are age-related change in thyroid function tests, for instance, simply dividing population into the immature, adult and the aged?

Adult↗