Biomedical subjects

M Tabata

Publications and source records attributed to M Tabata.

At least 109 records · Page 6Linked to original sources

PubMed1997

Characterization, guanosine 5'-O-(3-thiotriphosphate) modulation, daily variation, and localization of melatonin-binding sites in the catfish (Silurus asotus) brain.

Characteristics, guanosine 5'-O-(3-thiotriphosphate) (GTPgammaS) modulation, daily variation, and localization of melatonin-binding sites in the brain of a nocturnal teleost, the catfish Silurus asotus, were studied by radioreceptor assay using 2-[125I]iodomelatonin as the radioligand. The specific binding was rapid, stable, saturable, and reversible. The radioligand binds to a single class of receptor site with an affinity (Kd) of 30.7 +/- 7.3 pM and total binding capacity (Bmax) of 9.76 +/- 0.79 fmol/mg protein (mean +/- SE, n = 5). The binding sites were highly specific for 2-iodomelatonin and melatonin. The specificity was almost identical to that of functional melatonin receptors in the dermal and epidermal melanophores in this species and that of ML-1 subtype melatonin receptors in vertebrates, including melatonin-binding sites in the goldfish brain. GTPgammaS treatment altered both the Kd and Bmax values, indicating that melatonin-binding sites in the catfish brain are coupled to G protein. The Bmax values exhibited no daily variation under light-dark cycles of 12 hr light:12 hr dark whereas plasma melatonin levels and Kd fluctuated in a rhythmic fashion. The density of melatonin-binding sites in discrete brain areas was determined to be highest in optic tectum-thalamus and hypothalamus, intermediate in telencephalon, cerebellum, and medulla oblongata, and lowest in olfactory bulbs. These results suggest that melatonin secreted from the pineal organ and/or retina plays neuromodulatory roles in the catfish brain via G protein-coupled melatonin receptors. Characteristics of melatonin receptors seem to be highly conserved during evolution, although the density of melatonin receptors is not regulated by melatonin itself in this species.

Animals↗

PubMed1997

Megastigmane glycosides from Salvia nemorosa.

From the aerial parts of Salvia nemorosa, three new megastigmane glycosides, salvionosides A-C, were isolated, along with the known compounds, (6S,9R)- and (6S,9R)-roseosides, (6R,9R)- and (6R,9S)-3-oxo-alpha-ionol glucosides and blumeol C glucoside. The structures of the new compounds were elucidated on the basis of spectral and chemical evidence.

Carbohydrates↗

PubMed1997

Acrophase amplitude of ambulatory blood pressure decreases in migraineurs.

Ambulatory blood pressure was recorded and analyzed in 13 migraineurs during headache-free periods and in 11 healthy subjects. Systolic blood pressure, mean blood pressure, diastolic blood pressure, pulse pressure, and pulse rate were recorded for 48 hours (three times every hour from 6 AM to mid-night, once an hour at night). Circadian variation of blood pressure was analyzed using single cosinor analysis and group mean cosinor analysis methods. Single cosinor analysis identified significant circadian rhythm of systolic blood pressure in 10 of 11 control subjects (90.9%) and 5 of 13 migraineurs (38.5%, P < 0.02 versus controls, Fisher's exact test). Incidences of significant circadian rhythm of mean blood pressure and diastolic blood pressure were 100% and 100% in controls, 46.2% and 53.8% in the migraineurs (P < 0.01, P < 0.02 versus controls). Incidences of significant rhythm of pulse pressure were 36.3% in controls and 38.5% in the migraine group (difference was not significant). Group mean cosinor analysis identified significant circadian rhythm in both the migraine group and the controls. The MESOR (midline estimating statistic of rhythm) values of systolic, mean, and diastolic blood pressures showed no significant differences between the migraine group and the controls. Acrophase amplitudes of systolic, mean, and diastolic blood pressure were 4.2, 5.2, and 5.9 mm Hg in the migraine group, respectively; and 7.2, 7.3, and 7.5 mm Hg in the controls, respectively. These amplitudes of systolic, mean, and diastolic blood pressures in the migraine group were significantly smaller than those in the controls. These data suggest that some migraineurs lose or alter their circadian blood pressure rhythm. Evaluating migraineurs as a group, significant circadian rhythm of blood pressure can be identified and oscillation amplitudes of blood pressures are decreased. The present results suggest that migraineurs may be subject to dysfunction of the circadian rhythm generator and the autonomic nervous system. Possible involvement of serotonergic projections from the raphe to the suprachiasmatic nuclei of the hypothalamus in migraine is discussed.

Adult↗

PubMed1997

Importance of the transitional zone between the cervical stroma and the parametrium in the treatment of cervical carcinoma.

OBJECTIVES: Parametrial invasion is an important risk factor in cervical carcinoma. Because the vessels of the parametrium start in the zone between the cervical compact stromal layer and the parametrium, which we have defined as the parametrial initial zone (PIZ) or transitional zone, the invasion of a carcinoma into this part of the cervix is also important. Our objectives in this study were find a characteristic index of the transitional zone and to clarify the relationship between a transitional-zone invasion and the prognosis in a case. METHODS: Thirty-three cases of carcinoma in situ were available to use for the morphological examination of the cervix. The cervix was divided into 8-12 sections. In each section, the outer diameters of the short axis of the arteries were measured with a light microscope and a micrometer. Using the arterial diameter as the characteristic index of the transitional zone, we performed epidemiological studies on 312 patients with clinical Stage Ib-III squamous-cell carcinoma of uterine cervix. RESULTS: The arteries with an axis exceeding 300 microns were concentrated in the transitional zone at a rate of 94.6%. Therefore, arteries of this size are used as the characteristic index of the transitional zone. Patients with invasion to transitional zone only had lymph node metastasis at the rate of 28.1%, compared with 0% for patients who had no permeation to the zone (p < 0.001). The 5-year survival rate of patients with invasion to the transitional zone only was 87.3%, which is significantly lower than those without invasion (99.2%) (p < 0.01). CONCLUSIONS: Measuring the short axis (300 microns < or = ) of the artery is the best method by which to pinpoint the transitional zone. The invasion of a carcinoma into the transitional zone in the cervix should be treated as a parametrial involvement.

Adult↗

PubMed1997

An immunohistochemical study of thrombomodulin in oral squamous cell carcinoma and its association with invasive and metastatic potential.

Thrombomodulin (TM) is a glycoprotein that was originally identified on vascular endothelium and characterized as a natural endothelial anticoagulant. We reported previously that TM was also expressed at cell-cell boundaries of squamous epithelium, except in the basal layer cells and upper granular layer cells. The expression pattern of TM in the squamous cells implies that this molecule might be associated with keratinocyte differentiation, as well as being a potent anticoagulant. In the present study we examined TM expression immunohistochemically in biopsy specimens from 65 patients with primary oral squamous cell carcinoma (OSCC), and compared the results with the biological behavior of the carcinomas. The patients with intense TM expression in the carcinoma showed a significantly lower frequency of lymph node metastasis and significantly more favorable survival than those with negative TM expression. The TM expression was a better marker than the other prognostic factors, such as differentiation degree, tumor size and invasion mode. When TM expression was compared between the primary and metastatic lesions in the 36 patients who had lymph node metastasis, 14 (39%) showed decreased TM expression, 19 (53%) showed no change, and 3 (8%) showed an increase in the metastatic lesions. Wilcoxon's signed-rank test indicated that tumor cells positive for TM expression were significantly rarer in the metastatic lesions than in the primary tumors (P < 0.05). These results indicate that reduced expression of TM is associated with metastasis of carcinoma cells. The reduction of TM expression seems to play an important role in the metastatic process of OSCC, and to be related with a poor outcome for the patients.

Adult↗

PubMed1997

Prognosis of Parkinson's disease in Japan. Tottori University Parkinson's Disease Epidemiology (TUPDE) Study Group.

Therapy for Parkinson's disease (PD) has been progressing. However, the prognosis for patients with PD is still unclear. We studied the course of PD in patients in the San-in Area of Japan over a long time period. The main purpose of this study was to see whether there was a difference in survival between PD patients and the general population. Information on 114 deceased PD patients, who died between 1989 and 1996, was collected from hospitals belonging to the Tottori University Parkinson's Disease Epidemiology Study Group. Although the duration of illness was prolonged, the survival of PD patients was still poorer than that of the general population. The most common cause of death was pneumonia. The main cause of death in young PD patients was also pneumonia. In order to improve the survival of PD patients, PD-related conditions should be treated more extensively, especially pneumonia.

Aged↗

PubMed1997

Ocular melatonin rhythms in the goldfish, Carassius auratus.

Ocular melatonin rhythms in the goldfish were studied and compared to those in the pineal organ and plasma. Under light:dark (LD) of 12 h light:12 h dark, melatonin contents in the eye as well as the pineal organ and plasma exhibited clear day-night changes with higher levels at mid-dark than at mid-light. However, melatonin contents in the eye at mid-light and mid-dark were approximately 100 and 9 times greater than those in the pineal organ, respectively. Day-night changes of ocular melatonin persisted after pinealectomy, which abolished those in plasma melatonin under LD 12:12. Ocular melatonin contents in the pinealectomized fish at mid-light were significantly higher than those in the sham-operated control. Under constant darkness (DD), circadian melatonin rhythms were observed in the eye but damped on the 3rd day, whereas plasma melatonin rhythms generated by the pineal organ persisted for at least 3 days. Under constant light, ocular melatonin contents exhibited a significant fluctuation with a smaller amplitude than that under DD, whereas plasma melatonin remained at low levels. These results indicate the involvement of LD cycles, a circadian clock, and the pineal organ in the regulation of ocular melatonin rhythms in the goldfish.

Animals↗

PubMed1997

Growth inhibitory effects of antifolates against an adriamycin-resistant human small cell lung cancer cell line.

We have established an Adriamycin (ADM)-resistant small cell lung cancer (SCLC) cell line, SBC-3/ADM 100, which shows multifactorial mechanisms of resistance to ADM, such as over-expression of P-glycoprotein, an enhanced detoxifying system and a decrease in topoisomerase II activity. In the present study, we confirmed that SBC-3/ADM 100 showed collateral sensitivity to methotrexate and TNP-351, a new antifolate, though this cell line showed a typical multidrug resistance (MDR) pattern. We also demonstrated a faster uptake and higher accumulation (1.3-fold) of TNP-351 in the SBC-3/ADM 100 cells than those in the parent SBC-3 cells. These results explain one of the mechanisms for collateral sensitivity in the resistant cells. Furthermore, this cell line was found to have no cross-resistance to edatrexate and minimal cross-resistance to trimetrexate, 254-S (cisplatin analog), 5-fluorouacil and 4-hydroperoxyifosfamide. These drugs will have clinical importance in patients with SCLC who were previously treated with an ADM-containing regimen. Thus, antifolates, especially TNP-351 and edatrexate, can be expected to eradicate residual multidrug resistant SCLC cells selected by ADM.

Animals↗

PubMed1997

Direct intracerebral invasion from skull metastasis of large cell lung cancer.

A 56-year-old Japanese woman was referred to us for the treatment of lung cancer. On admission, the patient showed multiple bone metastases, including the skull, without brain metastasis. During chemoradiotherapy for the primary tumor and bone metastasis involving the thoracic spine, she suffered a fatal intracerebral hemorrhage. Since the patient had no risk factors for intracerebral hemorrhage, the skull bone metastasis was thought to be responsible for this event. At autopsy, penetration of the metastatic tumor from the skull bone into the dura, with direct invasion of the brain tissue, was confirmed histologically. A hematoma also was identified at the same site adjacent to the skull bone metastasis. To our knowledge, direct tumor invasion to the brain from a skull metastasis of non-small cell lung cancer has not been previously reported.

Biopsy↗

PubMed1997

High-dose etoposide treatment for CNS involvement in a patient with primary non-Hodgkin's lymphoma of the breast.

A 46-year-old man was referred to us for treatment of non-Hodgkin's lymphoma (NHL; diffuse large immunoblastic B cell type), which had initially developed in the breast. He was treated with five courses of chemotherapy with CHOP (cyclophosphamide, adriamycin, vincristine, and prednisolone) and achieved a complete response. One year later, he noticed a gait disturbance. Magnetic resonance imaging (MRI) of the brain showed multiple nodules. A few abnormal cells were found in the cerebrospinal fluid (CSF). He was treated with high-dose etoposide (1,350 mg/ m2/course). After two courses, both the multiple nodular lesions in the brain and the abnormal cells in the CSF were resolved. High-dose etoposide is effective for CNS involvement by NHL.

Antineoplastic Agents, Phytogenic↗

PubMed1997

[Deterrent factors in rehabilitation training following cerebral vascular disease--comparison of elderly and non-elderly patients].

The purpose of the present study was to clarify the deterrent factors for rehabilitation training (rehab) of chronic cerebral vascular disease (CVD) patients, and also to evaluate the influence of age on these factors. Sixty-five CVD impatients with sequelae treated at the Cerebral Vascular Center of Nanasawa Hospital were included in the study. Patients were classified into two groups using the Barthel index score: good effect group (n = 21) or no effect group (n = 22). The following factors were compared between the two groups in order to investigate which factor most affects the results of rehab: age, sex, the site of brain damage, extent of motor paralysis, character (Type A character or not), aphasia, hemispacial neglect, depression, and positive attitude toward training. A possible association between depression, and the site of brain damage and Type A character was investigated. Also, the difference in mood disorders was compared between elderly and non-elderly stroke patients. In the elderly group, hemispacial neglect, a negative attitude toward training, and depression all adversely affected the outcome of the rehab. In the non-elderly group, aging, hemispacial neglect, and a negative attitude toward training influenced the effect of the rehab, but there was no correlation with depression. Depression was seen in 64% of the patients (38/59). Of the 38 patients in a depressed state, 24 (63%) had right hemisphere brain damage, 13 (34%) had left hemisphere brain damage, and 1 (3%) had brain stem damage. Twenty-seven of the 38 depressed patients (71%) were Type A character, significantly more than in the non-depressed group (92/21, 43%). In addition, 14 of the 27 Type A patients were aged over 65 years (52%), which was more than in the non-depression group (11/38, 29%).

Adult↗

PubMed1997

[Small cell lung cancer with acute monocytic leukemia after combined chemotherapy including etoposide].

Small cell lung cancer (stage IIIB) developed in a 61-year-old woman. She was treated with chemotherapy in which the cumulative dose of carboplatin was 662 mg/m2 and that of etoposide was 2,000 mg/ m2, and with concurrent irradiation in which the total dose of X-rays was 44.8 Gy. The response to chemotherapy and irradiation was very good. Radiation pneumonitis developed after discharge, but it resolved after steroid therapy. Nine months after the diagnosis of lung cancer the patient was readmitted because of bleeding and leukocytosis. Acute monocytic leukemia (M5a) was diagnosed after examination of a bone-marrow aspirate. The patient was treated with chemotherapy, but she died of severe bone-marrow suppression and multiple organ failure 3 months after the diagnosis of acute monocytic leukemia. Although chromosome analysis could not be done, we strongly suspect that this leukemia was induced by etoposide, because of the clinical course.

Antineoplastic Agents, Phytogenic↗

PubMed1997

Ischaemic heart disease deaths in a Japanese rural area evaluated by clinical records.

A community-based survey to examine the actual number of ischaemic heart disease (IHD) deaths was undertaken in the western area of Toyama, a rural area with a population of 209,000. IHD deaths (International Classification of Diseases [ICD], ninth revision, codes 410-414) and heart failure (HF) deaths (ICD code 428) according to the death certificate aged 15 to 74 in 1987 to 1990 were reevaluated from medical records using the criteria of the multinational monitoring of trends and determinants in cardiovascular disease (MONICA). Of 97 subjects with IHD and of 170 subjects with HF according to the death certificate, 85 cases (87.6%) and 143 cases (84.1%) could be examined, respectively. Using the MONICA criteria, of 85 subjects with IHD, 18 (21.2%) were reevaluated as "definite acute myocardial infarction (AMI)" and 30 (35.3%) as "possible AMI". On the other hand, of 143 subjects with HF, 1 (0.7%) were reevaluated as "definite AMI" and 12 (8.4%) as "possible AMI". From these results, the number of deaths as reevaluated IHD was estimated 104.5 in the study period, and it was 7.7% increase at least compared with the number of deaths judged from the death certificate.

Adolescent↗

PubMed1997

[Double autologous peripheral blood stem cell transplantation (double APBSCT) for lymphoblastic lymphoma].

A 24-year-old male was admitted to our hospital, complaining of right back pain, in May 1995. Chest X-ray films showed an abnormal mass in the mediastinum. Computed tomography revealed massive effusion in the pleural and pericardial space. A biopsy specimen of the pleural lesion demonstrated lymphoblastic lymphoma of T cell type. After the completion of intensive chemotherapy by our original protocol, he entered into partial remission. Peripheral blood stem cells (PBSC) were harvested using a high-dose cytarabine (Ara-C) followed by granulocyte-colony stimulating factor (G-CSF) mobilization regimen. The total number of collected PBSC was enough to perform two courses of PBSCT. In January 1996, following the conditioning regimen of nimustine hydrochloride, etoposide (VP-16), Ara-C, thiotepa, he received PBSCT. Complete remission was achieved after the 1st PBSCT. In March 1996, he received the 2nd PBSCT following the conditioning regimen of carboplatin, VP-16, ifosfamide. No regimen-related toxity or delayed engrafment was observed. Subsequently, he received irradiation to his neck and mediastinum, the primary site of the disease. As of February 1997, he has no evidence of the disease.

Adult↗

PubMed1996

cDNA cloning, characterization, and functional expression of 4S-(-)-limonene synthase from Perilla frutescens.

A molecular biological study on limonene synthase that catalyzes the cyclization of geranyldiphosphate to yield the olefin 4(S)-limonene, an intermediate in the biosynthesis of a monoterpenoid, perillaldehyde, in Perilla frutescens Britton has been carried out. We isolated and characterized 10 cDNAs homologous to spearmint limonene synthase cDNA from an expression library constructed from cotyledons of a Perilla strain homozygous for two pairs of dominant genes, G and H, which are responsible for the formation of 4(S)-limonene. Two of these cDNA clones were functionally expressed in Escherichia coli, yielding enzymes which were catalytically active in generating 4(S)-limonene from geranyldiphosphate. The longest open reading frame in the representative cDNA clone PFLC1 consisted of 1812 nucleotides corresponding to 603 amino acids. Its identity to the ORFs of spearmint limonene synthase, tobacco 5-epi-aristolochene synthase, and castor bean casbene synthase were 65, 35, and 30%, respectively. Genomic Southern blot analyses of various genotypes (GGHH, GGhh, ggHH, and gghh) of P. frutescens suggested that more than one copy of the PFLC1 DNA exists in strains having the HH genotype. In contrast, no PFLC1 DNA sequences were found in the genomes of strains with the hh genotype that are incapable of producing cyclohexanoid monoterpenes for lack of limonene synthase activity. Northern blot analysis, using a PFLC1 3'-flanking region as a hybridization probe, showed that PFLC1 mRNA accumulated in all the aerial parts of the GGHH plants, particularly in the leaves. In the ggHH plants, on the other hand, PFLC1 mRNA was detected only in minute amounts in the stem and calyx.

Amino Acid Sequence↗

PubMed1996

Relationship between job stress and plasma fibrinolytic activity in male Japanese workers.

Psychosocial job stress has been shown to be associated with the development of cardiovascular disease. However, the pathophysiological mechanisms underlying this relationship remain unclear. The aim of the present study was to elucidate whether marked job stress affects the parameters of blood coagulation and fibrinolysis, such as plasma fibrinogen concentration, tissue plasminogen activator (t-PA), and plasminogen activator inhibitor 1 (PAI-1) activities, in 213 middleaged male workers in a computer-producing factory. Job stress was measured using a Japanese version of the Job Content Questionnaire (JCQ) developed by Karasek. The mean t-PA activity in workers with lower and higher job demands was 0.23 and 0.18 IU/ml respectively, and this difference was significant (P < 0.05). The mean plasma fibrinogen in workers with lower and higher job decision latitude was 224.8 and 236.3 mg/dl respectively, and the mean PAI-1 activity in workers with lower and higher job strain was 14.9 and 17.7 U/ml respectively, though these differences remained at a borderline level of significance (0.05 < P < 0.10). Multiple regression analyses showed that the parameters of blood coagulation and fibrinolysis were closely associated with the cardiovascular risk factors of age, obesity, blood pressure, elevated serum lipids, and smoking, but that high job demands were significantly related to decreases in t-PA activity, independently of the traditional risk factors. These results suggest that psychosocial job stress may be related, at least partly, to the development of cardiovascular disease via changes in plasma fibrinolytic activity.

Adult↗

PubMed1996

Ultrasonographic assessment of intragastric volume in neonates: factors affecting the relationship between intragastric volume and antral cross-sectional area.

Measuring antral cross-sectional area by ultrasonography can be an ideal way to evaluate intragastric milk volume in infants. Technical details, however, remain to be established before its clinical application. We investigated the effects of posture and ultrasonographic plane on the correlation between milk volume and antral cross-sectional area. After gastric aspiration through a nasogastric tube, healthy newborns were fed 0, 10, 20, and 40 ml of milk cumulatively, and antral cross-sectional area was measured in either upright, sitting, or right lateral position. To determine the best sonographic plane, subjects were put in the right lateral position and antral cross-sectional area was measured in the plane of the aorta and either the superior mesenteric artery, the superior mesenteric vein, the midline of the abdominal surface, 1 cm right of midline, or 2 cm right of midline. The results showed that antral cross-sectional area reflects intragastric milk volume most accurately, with minimal gas interference when measured in the right lateral position. The area correlates well with milk volume in the plane of the aorta and either the superior mesenteric artery, the superior mesenteric vein, or the midline. Next, we studied the effect of intragastric gas on the antral cross-sectional area in subjects who were given 40 ml of milk followed by an injection of air. More than 20 ml of intragastric gas increases antral cross-sectional area significantly. Ultrasonographic evaluation of intragastric volume requires attention to the above factors.

Abdomen↗

PubMed1996

Circadian rhythms of locomotor activity in the goldfish Carassius auratus.

Locomotor activities in the goldfish Carassius auratus were recorded under light-dark (LD) and constant light regimens. Under LD 12:12, all goldfish adjusted to given LD cycles. Activity patterns were classified into three types: L-type activity during the photophase (83%), LD-type activity both during the photophase and the scotophase (10%), and D-type activity during the scotophase (7%). However, these patterns were not fixed, but flexible. Under constant conditions, goldfish exhibited circadian locomotor activities: The proportions of appearance of circadian rhythms and tau values under constant darkness (DD), constant light (LL, 500 lx) and constant dim light (dimLL, 20 lx) were 57% (24.4 +/- 1.6 h, [mean +/- SE], n = 34), 57% (25.2 +/- 2.5 h, n = 35) and 67% (26.0 +/- 3.4 h, n = 10), respectively. These results indicate that the goldfish exhibit flexibility in phasing of locomotor activity rhythms under LD 12:12. In addition, the coupling between circadian clocks and locomotor activities does not seem strong, although the diel locomotor activity in the goldfish is regulated, in part, by a circadian clock. These results are discussed in context with the structure of the teleostean circadian system.

Animals↗