Biomedical subjects

M Nakaya

Publications and source records attributed to M Nakaya.

At least 37 records · Page 2Linked to original sources

PubMed1998

The composition of the depressive syndrome in acute schizophrenia.

The composition of the depressive syndrome was examined at both the acute and chronic phases of schizophrenic illness in 86 newly admitted patients. A subgroup with pronounced depression was defined, and a discriminant analysis was performed using symptoms from the Hamilton Rating Scale for Depression (HRSD) as discriminant variables. At the acute phase, the following nine symptoms from the HRSD were significant: depressed mood, guilt, suicide, retardation, three types of insomnia, and two somatic symptoms. At the chronic stable phase, only four symptoms were significant: depressed mood, suicide, general somatic symptoms, and loss of weight. Initial insomnia, middle insomnia, genital symptoms, and loss of insight were poorly correlated. The positive and negative symptoms and extrapyramidal side-effects were not discriminators at either phase. These findings suggest that only certain items from the HRSD may be crucial when assessing depression in schizophrenia.

Acute Disease↗

PubMed1998

Atypical protein kinase Clambda binds and regulates p70 S6 kinase.

p70 S6 kinase (p70 S6K) has been implicated in the regulation of cell cycle progression. However, the mechanism of its activation is not fully understood. In the present work, evidence is provided that an atypical protein kinase C (PKC) isotype, PKClambda, is indispensable, but not sufficient, for the activation of p70 S6K. Both the regulatory and kinase domains of PKClambda associate directly with p70 S6K. Overexpression of the kinase domain without kinase activity or the regulatory domain of PKClambda results in the suppression of the serum-induced activation of p70 S6K. In addition, two types of dominant-negative mutants of PKClambda, as well as a kinase-deficient mutant of p70 S6K, suppress serum-induced DNA synthesis and E2F activation. The overexpresion of the active form of PKClambda, however, fails to activate p70 S6K. These results suggest that PKClambda is a mediator in the regulation of p70 S6K activity and plays an important role in cell cycle progression.

Amino Acid Sequence↗

PubMed1998

Thermal unfolding of three acclimation temperature-associated isoforms of carp light meromyosin expressed by recombinant DNAs.

Differential scanning calorimetry (DSC) was performed to investigate thermodynamic properties of three carp fast skeletal light meromyosin (LMM) isoforms expressed in Escherichia coli by recombinant DNAs. Three isoforms were the 10 degreesC-, intermediate-, and 30 degreesC-type LMM predominantly expressed in carp acclimated to 10, 20, and 30 degreesC. The isoforms expressed in E. coli by recombinant DNAs exhibited a typical pattern of alpha-helix in CD spectroscopy with two minima at 222 and 208 nm. Moreover, the three isoforms formed paracrystals typical of LMM, suggesting that expressed proteins retained intact structural properties. When the LMM isoforms were subjected to DSC analysis, the 10 degreesC and 30 degreesC types showed endotherms having transition temperatures (Tm) at 35.1 and 39.5 degreesC, respectively, which are responsible for thermal unfolding of alpha-helix. The intermediate type exhibited two comparable endotherms with Tm values at 34.9 and 40.6 degreesC, implying that it has intermediate thermodynamic properties between those of 10 degreesC and 30 degreesC types. However, a chimeric LMM having the 10 degreesC and 30 degreesC type as N- and C-terminal halves, respectively, showed the DSC pattern typical of the whole 30 degreesC-type molecule. On the other hand, another chimeric LMM composed of the N-terminal 30 degreesC type and C-terminal 10 degreesC type gave the pattern of the full 10 degreesC type. These results suggest that thermodynamic properties of the C-terminal half largely account for thermal unfolding of the whole molecule.

Acclimatization↗

PubMed1998

[A mitral valve reconstruction of infective endocarditis with brain abscess and intracranial mycotic aneurysm].

A case is reported of a brain abscess and an intracranial mycotic aneurysm associated with infective endocarditis caused by streptococcus intermedius. A 60-year-old man with a history of fever presented aphasia and right hemiparesis. A computed tomographic scan of the head revealed a low-density area with ring enhancement in the left parietal lobe consistent with a brain abscess. An angiography demonstrated an aneurysm on the distal branch of the middle cerebral artery compatible with a mycotic aneurysm. Doppler echo cardiography showed severe mitral regurgitation by chordal ruptures. The brain abscess and intracranial mycotic aneurysm were resolved under appropriate antibiotic therapy for eight weeks. Then, the mitral valve was reconstructed by replacement of the chordae tendineae with expanded polytetrafloroethylene suture and annuloplasty. The patient had no neurologic deficit except for paresthesia in the right hand, and had no mitral regurgitation at discharge.

Aneurysm, Infected↗

PubMed1998

Zinc ions prevent processing of caspase-3 during apoptosis induced by geranylgeraniol in HL-60 cells.

Geranylgeraniol (GGO) at 50 microM induces apoptosis in HL-60 cells. We examined the effects of Zn2+ ions on this process. Treatment of HL-60 cells with Zn2+ ions inhibited subsequent GGO-induced fragmentation of DNA. In a cell-free system that consisted of a specific substrate for caspase-3 and a lysate of HL-60 cells that had been treated with 50 microM GGO, Zn2+ ions at concentrations above 0.1 mM inhibited the activity of caspase-3. The effect of Zn2+ ions on the processing of caspase-3 during GGO-induced apoptosis was investigated by Western blotting, which revealed that an inactive 32-kDa precursor of caspase-3 was cleaved, in response to GGO, to yield an activated 17-kDa enzyme. Treatment of HL-60 cells with Zn2+ ions inhibited the cleavage of the precursor by a protease that was induced by treatment with GGO, and inhibition of this processing was well correlated with the inhibition by Zn2+ ions of caspase-3 activity in the cell-free system. In cell-extracted cytosols, Zn2+ ions inhibited the cleavage of the 32-kDa precursor by caspase-9 (Aapf-3) that was activated by addition of cytochrome c and dATP. These results indicate that inhibition of GGO-induced apoptosis in HL-60 cells by Zn2+ ions might be due to inhibition by Zn2+ ions of the processing of a precursor to caspase-3.

Apoptosis↗

PubMed1998

Inhibition of human immunodeficiency virus type 1 virion entry by dominant-negative Hck.

To study the role of Src family tyrosine kinases in infection with human immunodeficiency virus type 1 (HIV-1), we constructed an Hck mutant, HckN, that hinders signaling from wild-type Hck. HIV-1 produced in HckN-expressing cells was significantly less infectious to HeLa-CD4-LTR-beta-gal (MAGI) cells than HIV-1 produced in mock-transfected cells. The inhibitory effect of HckN was compensated for by the expression of vesicular stomatitis virus G protein. Finally, we found that the HIV-1 produced in the HckN-expressing cells entered into the cells less efficiently than did the control HIV-1. These results suggest that the Src family tyrosine kinases regulate entry of HIV-1 into target cells.

Gene Products, nef↗

PubMed1997

Differential scanning calorimetry and CD spectrometry of acclimation temperature-associated types of carp light meromyosin.

Differential scanning calorimetry and CD spectrometry were employed to study the thermal unfolding of light meromyosin (LMM) prepared from carp acclimated to different temperatures. The transition temperatures given by the major peaks at pH 8.0 in 0.6 M KCl for LMM from carp acclimated to 10 degrees C were 32.5 and 39.5 degrees C with the calorimetric enthalpies (DeltaHcal) of 269 and 52 kcal/mol, respectively. LMM from carp acclimated to 20 degrees C exhibited three peaks of transition temperatures at 34.5, 40.2, and 46.9 with DeltaHcal of 152, 20, and 10 kcal/mol, respectively. On the other hand, LMM from carp acclimated to 30 degrees C showed two different patterns. The first experiment gave two transition temperatures at 39.2 and 47.3 degrees C with DeltaHcal of 231 and 39 kcal/mol, respectively. The second series of experiments resulted in showing three peaks of 34.4, 39.5, and 47.5 degrees C with DeltaHcal of 117, 123, and 28 kcal/mol, respectively. N-terminal amino acid sequence analysis revealed that LMM at the second series of experiments with the 30 degrees C-acclimated carp contained component(s) predominant in the 20 degrees C-acclimated carp. Thermal unfolding responsible for these transition temperatures was well explained by melting of alpha-helices which could be determined by far-ultraviolet CD spectroscopy. These results clearly demonstrate that the 30 degrees C-acclimated carp contained the most thermostable LMM.

Acclimatization↗

PubMed1997

Geranylgeraniol potently induces caspase-3-like activity during apoptosis in human leukemia U937 cells.

In a previous study, we showed that geranylgeraniol (GGO) is a potent inducer of apoptosis in human leukemia cells. The present study describes the effects of GGO on the activity of cysteine-dependent aspartate-directed proteases (caspases) in human leukemia U937 cells. The caspase-3 (CPP32) activity was increased in a time-dependent manner by treatment with 50 microM GGO, whereas no activation of caspase-1 (interleukin-1beta converting enzyme (ICE)) was observed in any time period under the same experimental conditions. Other isoprenyl compounds such as geraniol, geranylgerany-lacetone, and vitamin K2 had no measurable effects on the activities of either caspase-3 or caspase-1. A inhibitor that preferentially inhibits the caspase-3 related caspases, Z-DEVD-FMK, strongly blocked the GGO-induced DNA fragmentation. These results suggest the involvement of caspase-3 in GGO-induced apoptosis in U937 human leukemia cells.

Apoptosis↗

PubMed1997

Depressive symptoms in acute schizophrenic inpatients.

Prospective and longitudinal assessment of depressive, positive, and negative symptoms were performed on 86 newly admitted schizophrenic patients. The improvement of depressive symptoms was significantly correlated with the improvement in positive symptoms, but did not correlate with the improvement in negative symptoms. However, depressive symptoms were heterogeneous. Principal components analysis was used to subdivide depressive symptoms into five factors. The improvement of the depression-anxiety factor was significantly associated with improvement of positive symptoms. On the other hand, improvement of negative symptoms was significantly related to that of the reduced activity factor. The change in hypochondriasis had a significant positive correlation with the change in positive symptoms and had a significant negative correlation with the change in negative symptoms. Changes in the other factors of depressive symptoms did not appear to be associated with changes in positive or negative symptoms. The present findings suggest that the various depressive symptoms associated with acute schizophrenia may have different pathophysiological origins.

Adult↗

PubMed1997

Delusional repetitiveness--a peculiar form of delusional remembrance.

Delusional repetitiveness as a peculiar form of delusional remembrance is very rare in the literature and has not been considered in detail. the author presents a schizophrenic case with delusional repetitiveness and considers its features and meaning in treatment. The patient's feelings about a deadlock in treatment were substantiated in delusional repetitiveness. In repetitiveness, we should try to take a new look at the method of treatment and prepare ourselves for the interruption of treatment according to circumstances.

Adult↗

PubMed1997

The two essential light chains of carp fast skeletal myosin, LC1 and LC3, are encoded by distinct genes and change their molar ratio following temperature acclimation.

cDNA libraries were constructed from fast skeletal muscles of carp acclimated to 10 and 30 degrees C for a minimum of 5 weeks and were screened for myosin alkali light chains, LC1 and LC3, using an anti-skipjack LC1 polyclonal antibody. Two types of LC1 cDNA clone were isolated and termed LC1a and LC1b: their nucleotide sequences showed 92% homology. The ratio of LC1a to LC1b cDNA clones isolated was approximately 3:1, showing no apparent changes following temperature acclimation. The occurrence of the two isoforms was further confirmed by N-terminal amino acid sequencing of purified LC1. No isoform was, however, detected for LC3, while homology in the overlapping region between LC1a and LC3 cDNAs was only 65% even after the most probable alignment. Southern blot analyses probed with cDNA clones specific to LC1a and LC3 showed different hybridization patterns from each other, demonstrating that carp LC1 and LC3 are encoded by different genes. These results are in marked contrast to those from higher vertebrates which express LC1 and LC3 from a single gene by alternative RNA transcription and two modes of splicing. Northern blot analysis showed that the ratios of LC3/LC1 mRNAs were significantly higher (3.93) in 30 degrees C-acclimated than in 10 degrees C-acclimated (3.10) carp.

Amino Acid Sequence↗

PubMed1997

[Autopsy findings of retroperitoneal cystic tumor and peliosis hepatis in lymphangiomyomatosis].

A 40-year-old woman who worked as a nurse and had suffered from progressive exertional dyspnea for about 14 years underwent open lung biopsy with surgical treatment for pneumothorax. The diagnosis was lymphangiomyomatosis and she was treated with danazol to suppress ovarian function. Her condition improved temporarily, but she died of respiratory failure when she was 47 years old. The survival time after the onset of respiratory symptoms was 21 years, and after the biopsy it was 8 years. At autopsy a retroperitoneal cystic tumor was found (9 x 7 x 5 cm), which had been evident clinically. Histologic examination showed that the tumor was an extrapulmonary manifestation of the lumphangiomyomatosis lesion. Some paraaortic lymph nodes has similar lesions. Aggregates of small red spots were seen on acute surface of the liver. These were diagnosed as peliosis hepatis, they may have been caused by the danazol.

Danazol↗

PubMed1997

[Cytokine producing ability of peripheral blood mononuclear cells in the clinical course of pulmonary tuberculosis].

Interferon-gamma (IFN-gamma) and interleukin-10 (IL-10)-producing ability of peripheral blood plastic-dish adherent cells and non-adherent cells obtained from patients with active pulmonary tuberculosis (N = 17) and healthy controls (N = 14) upon stimulation with purified protein derivatives (PPD) were assessed. Adherent cells and non-adherent cells were obtained two times from each patient with active pulmonary tuberculosis without any underlying diseases, on admission before the initiation of administering anti-tuberculous drugs and 2 months later from the negative conversion of Mycobacterium tuberculosis in sputum culture. ELISA was performed to measure IFN-gamma and IL-10 levels in culture media of adherent cells and non-adherent cells stimulated with PPD. IFN-gamma levels produced by non-adherent cells on admission were significantly higher than that of healthy controls (p < 0.001). Elevated IFN-gamma levels on admission was reduced after treatment for tuberculosis (p < 0.03), but still remained higher than that in healthy controls. IL-10 levels of non-adherent cells of patients were lower than those of healthy controls, although the difference was not significant. IL-10 levels produced by non-adherent cells on admission correlated with the time needed for negative conversion of bacilli in sputum culture (p < 0.05). IL-10 level produced by adherent cells from nutritionally normal patients were significantly higher than that of healthy controls (p < 0.05), and elevated IL-10 level was significantly reduced after therapy (p < 0.05). In the normonourished patients, the time needed for negative conversion of the bacilli in sputum culture of patients kept higher level of IL-10 of non-adherent cells (N = 5) was significantly longer than that of patients reduced IL-10 level after therapy. These results suggest that IL-10 produced by monocytes may diminish the TH1 responses of patients with pulmonary tuberculosis.

Acute Disease↗

PubMed1997

[A case of Mycobacterium intracellulare infection associated with sinobronchial syndrome].

The patient was 71-year-old male with a history of sinobronchial syndrome since 8 years ago. He has been suffering from cough, sputum and upper abdominal discomfort since January 1994. He was diagnosed as an early gastric cancer by endoscopy, and his chest X-ray film showed an infiltrative shadow in the right upper lung field. A smear of the sputum specimen was positive for acid fast bacilli, which were later identified as Mycobacterium intracellulare. In this case, before the Mycobacterium intracellulare infection, it was confirmed that his mucociliary transport was severely impaired by using aerosol inhalation cine-scintigraphy. This case suggests that an impairment of the local defence mechanisms may play an important role in the pathogenesis of Mycobacterium intracellulare infection.

Aged↗

PubMed1997

[Photomicrographs of a pleural biopsy specimen, showing malignant mesothelioma and necrosis--malignant pleural mesothelioma in a patient with sarcoidosis].

A 45-year-old woman was admitted to Nara Medical University Hospital because of right-sided chest pain. Both a chest X-ray film and a chest CT scan revealed bilateral hilar and mediastinal lymphadenopathy and right pleurisy. She underwent fiberoptic bronchoscopy and mediastinoscopy. Biopsy specimens of the lung and mediastinal lymph nodes showed non-caseous epithelioid cell granulomas. After on ophthalmologic examination, she was given a diagnosis of sarcoidosis with a pleural lesion and uveal involvement. The pleurisy become less severe and the lymph nodes shrank without any treatment. About one year later, she complained of right-sided chest pain again and a chest X-ray film revealed diffuse thickening of the pleural on the right side. Examination of pleural biopsy specimens revealed malignant mesothelioma. We know of no previous report from Japan of malignant pleural mesothelioma in a patient with sarcoidosis.

Biopsy↗

PubMed1997

[CD4+ alpha beta T cell and gamma delta T cell responses to BCG in patients with pulmonary tuberculosis--comparison with healthy controls].

We demonstrated that CD4+ alpha beta (CD4+) and gamma delta T cell subsets from healthy donors had similar effector functions (cytotoxicity and cytokine production) in response to mycobacterial antigens, despite differences in the antigens recognized. To elucidate the pathogenesis of pulmonary tuberculosis, this study was undertaken to compare T cell functions between patients with pulmonary tuberculosis with no complications and healthy controls. Both resting and activated CD4+ and gamma delta T cells from the patient group proliferated in response to live BCG at a significantly lower rate than those from the control group. The cytotoxicity of BCG-pulsed monocytes and IFN-gamma production in both the CD4+ and gamma delta T cells from patients was significantly lower than those of controls. In contrast to IFN-gamma, significantly higher IL-10 production by both CD4+ and gamma delta T cells from patients was detected. The proliferative responses to BCG by CD4+ and gamma delta T cells from patients after antituberculous therapy were partially restored, but remained at lower levels compared with controls. These results suggest that not only a general deterioration in CD4+ and gamma delta T cells effector functions, but also suppressive factors (such as IL-10) might be responsible for the pathogenesis of pulmonary tuberculosis, and that the low response to BCG by both CD4+ and gamma delta T cells in patients with tuberculosis is in part attributable to patient predisposition.

Aged↗

PubMed1996

Lower activation energy for sliding of F-actin on a less thermostable isoform of carp myosin.

We have examined the temperature-dependence of sliding velocity of fluorescent F-actin on myosins isolated from 10 degrees C- and 30 degrees C-acclimated carp. Activation energies for the sliding of F-actin were 63 and 111 kJ/mol for the 10 degrees C- and 30 degrees C-acclimated carp myosins, respectively. Arrhenius plots of the sliding velocity from 10 degrees C- and 30 degrees C-acclimated carp myosin were shown to intersect at high temperature (about 30 degrees C). The thermostability estimated by measuring the Ca(2-)-ATPase activity was less for myosin from 10 degrees C- than 30 degrees C-acclimated carp. We suggest that a less thermostable structure in cold-acclimated carp myosin results in a reduced activation energy for the contractile process, which allows the F-actin to slide fast even at low temperatures.

Acclimatization↗

PubMed1996

On background factors of male genital self-mutilation.

Background factors of male genital self-mutilation have been suggested in a small series of cases. A review of 110 cases in the literature revealed that guilt feelings associated with sexual conflicts were the most important factors in the act of psychotic self-mutilation and also related to religious psychotic experiences that were often the direct motives for the act. Self-mutilators with sexual guilt feelings were likely to mutilate themselves more severely than those without. Even excluding transsexuals, disturbance of sexual identity was most participating in the act of nonpsychotic self-mutilators. In addition to these, previous history of self-injury took part in the act independently. Male genital self-mutilation is exceedingly rare in psychiatric practice even if it is not as uncommon as the paucity of published literature on the subject would suggest. According to Blacker et al., the earliest report in English of male genital self-mutilation is Stroch's brief communication in 1901. Greilsheimer and Groves found 53 cases in the English literature that had been reported till 1979. We present a case report with male genital self-mutilation and examine the background factors of this phenomenon from a review of the literature. We used the literature files 'Medline' from 1979 to 1993 and the references of famous reports. In statistical analyses, we performed two-tailed t tests for continuous variables and chi 2 tests with Yates correction for categorical variables.

Adult↗