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Biomedical subjects

S Nishiwaki

Publications and source records attributed to S Nishiwaki.

At least 19 recordsLinked to original sources

Inter-ictal and post-ictal psychoses in frontal lobe epilepsy: a retrospective comparison with psychoses in temporal lobe epilepsy.

There have been few studies of the psychopathology of patients with frontal lobe epilepsy (FLE). The majority of studies of both inter-ictal and post-ictal psychoses have strongly suggested the influence of temporal lobe disturbance on psychoses. Patients with organic brain damage or schizophrenia, however, sometimes show frontal lobe dysfunction. The purpose of this study was to better understand the effect, if any, of frontal lobe disturbance and seizure on psychopathology. Patients were divided into four groups based on epilepsy type and preceding seizures; 8 with FLE/inter-ictal psychosis, 3 with FLE/post-ictal psychosis, 29 with temporal lobe epilepsy (TLE)/inter-ictal psychosis, and 8 with TLE/post-ictal psychosis. Psychopathologic symptoms were retrospectively reviewed based on case notes, using a modified brief psychiatric rating scale (BPRS). Psychomotor excitement, hostility, suspiciousness, and hallucinatory behaviour were prominent features in all four groups. Six orthogonal factors were derived by factor analysis from the original data based on the 18 BPRS items. FLE patients with inter-ictal psychosis showed marked hebephrenic characteristics (i.e. emotional withdrawal and blunted effect). Our findings suggest that patients with FLE can exhibit various psychiatric symptoms. However, their psychotic symptoms, hebephrenic symptoms in particular, may often be overlooked.

Adult↗

Determinant analysis of IgE and IgG4 antibodies and T cells specific for bovine alpha(s)1-casein from the same patients allergic to cow's milk: existence of alpha(s)1-casein-specific B cells and T cells characteristic in cow's-milk allergy.

In an effort to clarify the etiology of milk allergy from the standpoint of allergen-specific immune reactions, we investigated the determinants of IgE, IgG4, and T cells specific for bovine alpha(s)1-casein from the same individual patients by using its synthetic peptides and cyanogen bromide-digested fragments. Alpha(s)1-casein is a major allergen in cow's milk, and its unique conformation enabled us to investigate the determinants of antibodies without consideration about missing the reactivities because of conformational changes. Nine patients were selected as subjects from among 129 milk-sensitive infants screened by ELISA to assess the anti-alpha(s)1-casein IgE levels in their sera. By using ELISA for epitope mapping, a C-terminal region of alpha(s)1-casein was identified as a common binding site for IgE from all of these patients, whereas those for anti-alpha(s)1-casein IgG4 were located in multiple regions of alpha(s)1-casein. We determined the specificities of seven alpha(s)1-casein-specific T-cell lines established from peripheral blood mononuclear cells of two of the patients. These T cells have been shown to secrete IL-4. All of the T-cell lines had different specificities to alpha(s)1-casein. However, a common amino acid residue use was found among the determinants of various T-cell lines from each patient. The results suggest that patients allergic to cow's milk have characteristic B cells recognizing a limited region of alpha(s)1-casein and secreting alpha(s)1-casein-specific IgE. These B cells may interact particularly with T cells recognizing determinants with a common structure.

Amino Acid Sequence↗

The Schizosaccharomyces pombe mei4+ gene encodes a meiosis-specific transcription factor containing a forkhead DNA-binding domain.

The mei4+ gene of the fission yeast Schizosaccharomyces pombe was cloned by functional complementation. The mei4 disruptant failed to complete meiosis-I but could proliferate normally. mei4+ was transcribed only in meiosis-proficient diploid cells after premeiotic DNA replication. The mei4+ open reading frame encodes a 57-kDa serine-rich protein comprised of 517 amino acids with a forkhead/HNF3 DNA-binding domain in the amino-terminal region. Transcription of spo6+, a gene required for sporulation, was dependent on the mei4+ function. Two copies of the GTAAAYA consensus sequence, proposed as the binding site for human forkhead proteins, were found in the promoter region of spo6+. A gel mobility shift assay demonstrated the sequence-dependent binding of the GST-Mei4 forkhead domain fusion protein to DNA fragments with one of the consensus elements. Deletion of this consensus element from the spo6 promoter abolished the transcription of spo6+ and resulted in a sporulation deficiency. One-hybrid assay of Mei4 which was fused to the Gal4 DNA-binding domain localized the transcriptional activation domain in the C-terminal 140 amino acids of Mei4. These results indicate that Mei4 functions as a meiosis-specific transcription factor of S. pombe.

Amino Acid Sequence↗

A chloroplast-derived sequence is utilized as a source of promoter sequences for the gene for subunit 9 of NADH dehydrogenase (nad9) in rice mitochondria.

The chloroplast-derived sequence trnS-rps4/ 3'trnL-trnF-ndhJ-ndhK (4066 bases in length) is present in a region that starts 355 bases upstream of the gene for subunit 9 of NADH dehydrogenase (nad9) in the mitochondrial genome of rice. Northern blot hybridization revealed that three large transcripts of 3.05, 1.62 and 1.05 kb hybridized to strand-specific probes for both the nad9 gene and the chloroplast-derived sequence, indicating that the nad9 gene was transcribed together with the chloroplast-derived sequence. From the results of in vitro capping and ribonuclease protection experiments, as well as primer extension analysis, we identified at least seven sites for the initiation of transcription of nad9 in the chloroplast-derived sequence. All of the initiation sites for transcription of the nad9 gene were located in sequences homologous to chloroplast DNA. Two of seven initiation sites were flanked by a sequence homologous to the consensus promoter motif that includes the CRTA motif (where R is A or G) of the rice mitochondrion. However, the sequences surrounding the other five sites showed only limited similarity to the conserved sequence. It is suggested that all the promoters of the rice nad9 gene exist in a sequence that was transferred from the chloroplast during evolution. Thus, the chloroplast-derived sequence has a novel, significant function in the mitochondrial genome of this higher plant.

Base Sequence↗

Limited degradation of retinoid X receptor by calpain.

Recently, we have found two major physiological forms of retinoid X receptor alpha (RXR alpha): the mature 54 kDa RXR alpha and the truncated 44 kDa RXR alpha lacking a portion of N-terminal A/B domain in human and rodent livers. In this communication, we show that m-calpain was active to digest 54 kDa RXR alpha in the human hepatoma-derived cell line, HuH7, nuclei to 44 kDa fragment through 47 kDa intermediate in vitro. Although both proteolytic fragments were revealed by anti-RXR alpha antibody against its E-domain, neither fragment reacted with anti-RXR alpha antibody specific for A/B domain. The profile of the calpain-induced proteolytic fragmentation of RXR alpha was almost identical to that endogenous RXR alpha in nonmalignant human and normal mouse liver nuclei. This is the first demonstration that of RXR alpha is a substrate for m-calpain, strongly suggesting that the enzyme might also be involved in post-translational modification of the receptor in hepatocytes.

Animals↗

Aberrant metabolism of retinoid X receptor proteins in human hepatocellular carcinoma.

A polyclonal antibody was raised against a recombinant ligand binding domain construct of the human retinoid X receptor (RXR) alpha. This antibody reacted with an endogenous 54 kDa nuclear protein from human hepatoma-derived HuH7 cells in immunoblot analyses. Immunoblotting of nuclear proteins from human hepatocellular carcinomas (HCCs) and their surrounding tissues revealed the presence of a 44 kDa RXR distinct from the 54 kDa RXR and a dramatic decrease in the relative amounts of 44 kDa RXR to 54 kDa RXR in all HCCs compared with normal tissue. In vitro shift and intracellular conversion from 54 kDa RXR to 44 kDa species were observed with the nuclear extracts of HuH7 cells. Furthermore, transfection of hRXR alpha cDNA into HuH7 cells resulted in the increase of 54 kDa RXR, whereas transfected mouse hepatocytes accumulated 44 kDa RXR. These results strongly indicated that 44 kDa RXR was a physiological proteolytic fragment of 54 kDa RXR and that post-translational metabolism of RXR was impaired in HCC and the HuH7 hepatoma-derived cell line.

Animals↗

Establishment and characterization of alpha s1-casein-specific T-cell lines from patients allergic to cow's milk: unexpected higher frequency of CD8+ T-cell lines.

To study cow's milk allergy at the cellular level, we assessed the reactivity of peripheral blood mononuclear cells from patients allergic to cow's milk to alpha s1-casein, which is one of the major allergens in cow's milk. Proliferation of the cells to alpha s1-casein activation showed a rather weak response. Therefore to understand T-cell reactivity to alpha s1-casein in more detail, we prepared alpha s1-casein-specific T-cell lines from patients allergic to cow's milk and established 26 T-cell lines. These T-cell lines could be classified into three groups by analyzing their surface marker expression: those containing predominantly CD4+ CD8- T cells, those containing both CD4+CD8- and CD4-CD8+ T cells, and those containing predominantly CD4- CD8+ T cells. The CD8+ T cells were obtained at an unexpectedly higher frequency from the patients. These T-cell lines produced interferon-gamma and IL-4. These results suggest that CD8+ T cells specific for alpha s1-casein and CD4+ T cells were primed by the stimulation with alpha s1-casein in patients allergic to milk and that both T cells may play a key role in the onset, progression of, or recovery from cow's milk allergy.

CD8-Positive T-Lymphocytes↗

Suppression by carotenoids of microcystin-induced morphological changes in mouse hepatocytes.

Microcystin-LR is a liver tumor promoter in the okadaic acid class, a group of potent inhibitors of protein phosphatases 1 and 2A. Because of inhibition of protein phosphatases, microcystin-LR induces hyperphosphorylation of cellular proteins, including cytoskeletal proteins--cytokeratins 8 and 18--and causes morphological changes in mouse hepatocytes in primary culture. We studied the effects of carotenoids to antagonize microcystin-LR-induced morphological changes in hepatocytes. beta-carotene (100 nM to 100 microns) suppressed the morphological changes induced by 100 nM microcystin-LR in a dose-dependent manner. Other carotenoids tested exerted similar suppressive effects, although retinoids, such as all-trans retinol, all-trans retinoic acid, and 9-cis retinoic acid, were only weakly suppressive. The relative potency of the suppression correlated significantly with the number of conjugated double bonds in the trans configuration. beta-carotene strongly suppressed the hyperphosphorylation of cellular proteins induced by microcystin-LR without significant changes in the basal phosphorylation level. Other antioxidants, such as alpha-tocopherol, did not protect the cells against microcystin-LR. Taken together, the antagonistic effects of carotenoids against microcystin-LR are difficult to explain by their antioxidant or provitamin A activities. Suppression of the hyperphosphorylation of cellular proteins may be a novel mechanism by which carotenoids inhibit tumor promotion.

Animals↗

Activation of protein kinase C by mycobacterial cord factor, trehalose 6-monomycolate, resulting in tumor necrosis factor-alpha release in mouse lung tissues.

Cord factors are mycoloyl glycolipids in cell walls of bacteria belonging to Actinomycetales, such as Mycobacterium, Nocardia and Rhodococcus. They induce granuloma formation in the lung and interstitial pneumonitis, associated with production of macrophage-derived cytokines. We studied how cord factors induce biological activities in the cells. Cord factors isolated from M. tuberculosis, trehalose 6-monomycolate (mTMM) and trehalose 6,6'-dimycolate (mTDM), enhanced protein kinase C (PKC) activation in the presence of phosphatidylserine (PtdSer), diacylglycerol and Ca2+, and mTMM activated PKC alpha more strongly than PKC beta or gamma under the same assay conditions. Kinetic studies of mTMM in response to PKC activation revealed that mTMM increased the apparent affinity of PKC to Ca2+ in the presence of both PtdSer and diolein. Although this is similar to observations with unsaturated fatty acids, such as arachidonic acid, mTMM was synergistic with PtdSer for PKC activation, but arachidonic acid was not. mTMM was also different as regards PKC activation, as phorbol ester was. A single i.p. administration of mTMM to mouse induced tumor necrosis factor-alpha (TNF-alpha) in serum and in the lung, which is a unique target tissue of cord factors. Based on our recent finding that TNF-alpha is an endogenous tumor promoter, the correlation between lung cancer and pulmonary tuberculosis is discussed.

Animals↗

The effects of bifemelane hydrochloride on depressive illness of the elderly.

The therapeutic efficacy, utility and safety of bifemelane hydrochloride were studied in 52 elderly depressive patients. The drug was administered as a tablet containing 50 mg orally three times daily for 8 consecutive weeks. The final global improvement rating and global utility rating were respectively 80.8 and 73.1 percent for all patients. The improvement rates on the Hamilton depression rating scale (HAM-D) were more than 60% for depressed mood, guilt, suicide, middle insomnia, delayed insomnia, psychotic anxiety, gastro-intestinal symptom, hypochondriasis, depersonalization and derealization. The rates regarding global symptoms evaluated by the Psychoneurotic rating scale for doctor's use were more than 60% for tension, agitation, irritability and excitement, phobia, depression, hypochondria and nocturnal delirium in psychotic symptoms, and insomnia in addition to palpitation in somatic symptoms. A significant decrease was also observed in the symptoms covered by the Self-rating depression scale of Zung after treatment with this drug. There were no instances of side-effects, nor any abnormalities in laboratory tests, encountered throughout the trial. Therefore, bifemelane hydrochloride is of value for the treatment of geriatric depression.

Aged↗

A new method for detecting beta 1,4-galactosyltransferase activity in sera of cancer patients.

A new method for assaying the activity of the enzyme that catalyzes the formation of a cancer-associated glycolipid, paragloboside (nLc4Cer), from lactotriaosylceramide (Lc3Cer) and UDP-galactose has been developed that is based on a time-resolved fluoroimmunoassay (TRFIA) with a Europium (Eu)-chelate-labeled antibody. The substrate, Lc3Cer, immobilized on a microtiter plate, was incubated with UDP-galactose, MnCl2, Triton CF-54, and the enzyme. The content of the incubation product, nLc4Cer, was determined by the TRFIA with anti-nLc4Cer monoclonal antibody H-11 as the first antibody and Eu-labeled anti-mouse IgM antibody as the second one. The lower limit of detection of nLc4Cer was estimated to be 0.2 pmol. This method was used to detect the galactosyltransferase activity in sera from patients with colorectal cancer or benign colorectal adenomas and from healthy subjects of a reference sample group. The reference interval was 0-0.25 pmol/25 microliters serum/2 h. Activity was significantly greater in patients with colorectal cancer than in those with colorectal benign adenoma (P < 0.05) and the subjects of the reference sample group (P < 0.01).

Adenoma↗

Inhibitory effects of (-)-epigallocatechin gallate on spontaneous hepatoma in C3H/HeNCrj mice and human hepatoma-derived PLC/PRF/5 cells.

The inhibitory effect of (-)-epigallocatechin gallate (EGCG), a main constituent of Japanese green tea, on spontaneous hepatoma in C3H/HeNCrj mice was investigated. A total of 72 mice were divided into three groups; the control group without EGCG, and two experimental groups receiving 0.05% (w/w) or 0.1% EGCG in drinking water. EGCG reduced the incidence of hepatoma-bearing mice from 83.3% (control) to 56.0% (0.05% EGCG) and 52.2% (0.1% EGCG), and also reduced the average number of hepatomas per mouse from 1.83 (control) to 0.72 (0.05% EGCG) and 0.91 (0.1% EGCG) at week 65. Ridit analysis of the distribution of the number of hepatomas in each group revealed that EGCG significantly increased the rate of mice without hepatoma in the two EGCG groups as compared to the control. EGCG did not affect body weight gain, food consumption or any serum biochemical parameter. EGCG inhibited the growth and secretion of alpha-fetoprotein by human hepatoma-derived PLC/PRF/5 cells without decreasing their viability. These results indicate that EGCG may be a practical, nontoxic preventive agent against human hepatoma.

Animals↗

Elevation of 4 beta-galactosyltransferase activity for paragloboside synthesis in sera of patients with cancer.

Galactosyltransferase activities in sera of cancer patients were determined by assaying the formation of paragloboside from UDP-galactose and lactotriaosylceramide immobilized on microtiter plates by means of the enzyme-linked immunosorbent assay using a monoclonal antibody, H-11, directed to paragloboside. Enzyme properties were as follows. Optimum pH was 6.8 in cacodylate buffer, and Km values were 2 microM for lactotriaosylceramide and 29 microM for UDP-galactose. The enzyme activity was inhibited by the addition of alpha-lactalbumin. Glucose (20 mM) inhibited the enzyme activity in the presence of alpha-lactalbumin (0.1 mg/ml) but not in its absence. These enzyme properties are similar to those of bovine milk galactosyltransferase, indicating that the enzyme in the sera might be lactose synthetase. The enzyme activities in sera from patients with cancer, patients with benign disease, or a reference sample group were assayed. The activity was below the limit of detection (5.5 pmol/25 microliters serum/2 h) in the reference sample group. Remarkable elevations of the enzyme activity were observed with high incidence in patients with cancer, especially those with blood cancer (100%). A high incidence was observed in the progressive stage, and the enzyme activity was detected at stage 1 in lung, esophagus, stomach, colorectal, and testis cancer. The enzyme activity in sera from patients with benign disease was elevated in 22% of the patients. After effective therapies, the enzyme activity decreased to below the limit of detection. Release of the galactosyltransferase into culture medium of cancer cells could be demonstrated. These observations suggest that the galactosyltransferase is released from cancer tissue into the circulation. The present method for the assay of galactosyltransferase may be useful for the detection of patients with cancer and for monitoring neoplastic recurrence after therapy.

Antibodies, Monoclonal↗

Increased phosphorylation of nuclear phosphoproteins in human lung-cancer cells resistant to cis-diamminedichloroplatinum (II).

A novel non-phorbol-ester-like tumor promoter, okadaic acid (OA) has been shown to be an inhibitor of protein phosphatase I and IIA and, thus, to cause an "apparent activation" of protein kinase C (PKC). We previously showed that cis-diamminedichloroplatinum(II) (CDDP)-resistant cells, PC-9/CDDP, were cross-resistant to OA and that the cross-resistance was not due to the increased efflux of OA. We hypothesized that the phosphorylation status of some cellular proteins might be important in CDDP-resistance. No significant difference in PKC activity or total protein phosphatase activity measured in vitro was seen between PC-9 and PC-9/CDDP cells, nor in their sensitivity to inhibition by OA, nor in the amount of phosphorylation of whole cells or TCA-insoluble material. By SDS-PAGE after incubation of intact cells with 32P, we detected a marked increase, compared to PC-9 cells, in phosphorylation of the nuclear proteins of MW 32 and 20 kDa in CDDP-resistant PC-9/CDDP cells with no apparent difference in protein content. When phosphorylation of nuclear proteins observed in PC-9/CDDP cells was analyzed by 2-dimensional SDS-PAGE, the 32-kDa protein had a PI of about 4.5. The 32-kDa and 20-kDa bands were increased in a dose-dependent manner by CDDP treatment. On the other hand, no increase in phosphorylation of these proteins was observed in parental PC-9 cells. These results demonstrate a marked difference in the phosphorylation status of specific nuclear proteins between parental and CDDP-resistant cell lines, which may be related to CDDP-resistance.

Adenocarcinoma↗

Liver tumor promotion by the cyanobacterial cyclic peptide toxin microcystin-LR.

Certain waterblooms of toxic cyanobacteria (blue-green algae) are a health threat because of their production of toxic peptides, termed microcystins, which cause liver damage in wild and domesticated animals. The most widely studied microcystin is microcystin-LR, a heptapeptide containing the two L-amino acids, leucine and arginine. The inhibition of protein phosphatase type 1 and type 2A activities by microcystin-LR is similar to that of the known protein phosphatase inhibitor and tumor promoter okadaic acid. We show in this report that microcystin-LR, applied below the acute toxicity level, dose-dependently increases the number and percentage area of positive foci for the placental form of glutathione S-transferase in rat liver, which was initiated with diethylnitrosamine. The result was obtained independently through two animal experiments. This observation indicates that microcystin-LR is a new liver tumor promoter mediated through inhibition of protein phosphatase type 1 and type 2A activities. This provides further evidence that the okadaic acid pathway is a general mechanism of tumor promotion in various organs, such as mouse skin, rat glandular stomach and rat liver.

Alanine Transaminase↗