It is now apparent that adult neurogenesis is taking place during life in the olfactory bulb (OB) of the rodent brain. In the olfactory nervous system, the precursor cells of the subventricular zone are known to continually proliferate, migrate through the rostral migratory stream (RMS) and differentiate into the bulbar neurons. The RMS, consisting of heterogeneous cell populations of the neural and neuronal precursor cells, is the unique forebrain structure that provides a long-distance migratory route for the precursor cells. The present study was undertaken to examine whether neuronal regeneration, focusing on calretinin-immunoreactive (+) cells, may proceed in the RMS following lesions induced by an excitotoxin. Two days after ibotenate injections, massive degeneration of calretinin (+) cells occurred in the RMS and its adjacent forebrains. Thereafter, calretinin (+) cells gradually increased in the RMS and reached above their control value 2 weeks after ibotenate injections. Removal of the OB also produced a marked increase in calretinin (+) cells in the RMS. Autoradiographic experiments using (3)H-thymidine showed that calretinin (+) cells were continually generated in the RMS and underwent neuronal turnover within 8 weeks in a normal condition. The results indicate that, in terms of calretinin (+) cells, neuronal differentiation and replacement is continually taking place within the RMS, and that the RMS is capable of repopulating those cells which were injured by ibotenate.

Animals↗

PubMed2002

Lower number of K-complexes and K-alphas in sleep bruxism: a controlled quantitative study.

OBJECTIVES: Although patients with sleep bruxism (SB) show a higher incidence of rhythmic masticatory muscle activity (RMMA) during sleep than matched normal controls, they are good sleepers. Sleep macrostructure (e.g. total sleep time, sleep latency, number of awakenings or sleep stage shifts and sleep stage duration) is similar between groups. Differences in sleep microstructure between SB patients and normals have been investigated only in few studies. The aim of the present study was to quantify number of microarousals, K-complexes, K-alphas, EEG spindles, and the density of slow wave activity, in both groups, in order to better understand the pathophysiology of SB. METHODS: Ten normal sleepers were matched for age and gender with 10 patients who exhibited frequent tooth-grinding during sleep. Using quantitative polysomnographic measures, we compared the above-mentioned sleep variables in both groups. Data are presented as indices for total sleep and for consecutive non-rapid eye movement (non-REM) episodes over non-REM to rapid eye movement (REM) cycles and per hour of sleep. RESULTS: SB patients showed 6 times more RMMA episodes per hour of sleep than normals (P<0.001), with a higher frequency in the second and third non-REM to REM cycles. SB patients presented 42.7% fewer K-complexes per hour of stage 2 sleep, but only normals showed a decline from the first to fourth non-REM episode. Only 24% of SB-RMMA episodes were associated with K-complexes in 60 s. The number of K-alphas was 61% lower in SB patients, no change across non-REM episodes was noted. While no difference in electroencephalographic (EEG) spindles or slow wave activity (SWA) was observed between groups, EEG spindles increased and SWA decreased linearly over consecutive non-REM to REM cycles. CONCLUSIONS: According to our observations, good sleep in SB patients is characterized by a low incidence of K-complexes or K-alphas and by the absence of any difference in other sleep microstructure variables or SWA.

Adult↗

PubMed2002

Decreased cerebral haemodynamic response to cognitive and physiological tasks in mood disorders as shown by near-infrared spectroscopy.

BACKGROUND: Hypofrontality has been demonstrated in mood disorders by functional brain imaging methods such as positron emission tomography. However, the neurobiological basis of hypofrontality has not been well clarified. Near-infrared spectroscopy (NIRS) is a non-invasive technique for continuous monitoring of alterations in oxygenated (oxyHb) and deoxygenated (deoxyHb) haemoglobin using near-infrared light, which penetrates biological tissues. METHODS: We used NIRS during cognitive and physiological tasks to investigate alterations of haemoglobin oxygenation in the frontal region of euthymic patients with mood disorders (major depressive disorder (MD) and bipolar disorder (BP)) and in controls. RESULTS: The increase of oxyHb during a verbal fluency task was significantly less in the MD and the BP groups than in the controls. The MD group showed a significantly smaller decrease of oxyHb during hyperventilation than the controls. The BP group also showed a similar trend. CONCLUSIONS: These findings suggest that the hypofrontality in mood disorders may be associated with a poor response in the cerebral blood vessels to neuronal and chemical stimuli.

Adult↗

PubMed2002

Clonal expansion of limited T cell clonotypes in affected muscle from a patient with post-transplant polymyositis.

Critical roles of T cells in idiopathic polymyositis have been suggested, but, those in polymyositis occurring as GVHD after BMT are poorly understood. We thus investigated T cell clonality in a patient with post- transplant polymyositis. As a result, T cell receptor beta chains used various BV families in peripheral blood, but only one BV family (BV7) in affected muscle. Importantly, T cells proliferated oligoclonally both in the peripheral blood and the muscle, however, the expanded clonotypes were completely different. Taken together, T cells expanded in the muscle, possibly stimulated by limited kinds of antigens, may drive myositis.

Adult↗

PubMed2002

Effects of cocaine and reserpine administration on RNA editing of rat 5-HT2C receptor estimated by primer extension combined with denaturing high-performance liquid chromatography.

Serotonin 2C receptor (5-HT(2C)R) transcripts undergo RNA editing, generating pharmacologically different isoforms. To test whether the RNA editing of 5-HT(2C)R is regulated by serotonergic activity, effects of cocaine or reserpine administration in the rat cerebral cortex were examined. Although these drugs have been known to alter serotonin metabolism, no alterations in the RNA editing were found by the sequencing analysis. Towards high throughput analysis, we developed a non-RI method that allows accurate and rapid estimation of RNA editing by combining the primer extension with denaturing high-performance liquid chromatography (DHPLC). By using this, RNA editing efficiencies of 5-HT(2C)R in the midbrain and hippocampus as well as the cerebral cortex were examined, and no alterations were found among these regions. Our method using DHPLC is applicable to examine association of RNA editing with various diseases.

Amino Acid Sequence↗

PubMed2002

Eradication of Helicobacter pylori infection induces an increase in body mass index.

BACKGROUND: The relationship between H. pylori infection and body mass indices is controversial. AIM: To investigate the relationship between H. pylori infection and body indices, and to examine the effect of H. pylori eradication therapy on body indices. METHODS: Nine-hundred and thirty-two employees of an industrial corporation were examined for H. pylori infection and body mass indices. Three hundred and two H. pylori-positive cases diagnosed with chronic gastritis by upper gastrointestinal endoscopy or radiography underwent eradication therapy. Body mass indices, serum total cholesterol levels and symptom scores were obtained before and at 12 months after eradication therapy. RESULTS: There was no significant difference in body weight, body mass index (BMI) or serum total cholesterol level between the H. pylori-positive and H. pylori-negative groups. However, body weight and BMI increased significantly 12 months after eradication of H. pylori infection. In contrast, there was no significant difference in body weight and BMI 12 months after eradication therapy in the non-eradication group. Serum total cholesterol levels did not change after eradication therapy in either the eradication or non-eradication groups. CONCLUSION: Eradication of H. pylori infection induced an increase in BMI in industrial workers with chronic gastritis in Japan.

Adult↗

PubMed2002

The effects of CD40- and interleukin (IL-4)-activated CD23+ cells on the production of IL-10 by mononuclear cells in Graves' disease: the role of CD8+ cells.

The possible roles of CD8+ cells in the abnormal T cell-dependent B-cell activation in Graves' disease were investigated by analysing lymphocyte subsets in peripheral blood mononuclear cells (PBMC) and their production of soluble factors and cytokines such as IL-10 in patients with Graves' disease, Hashimoto's thyroiditis and normal controls. The PBMC were separated into CD8+ and CD8-depleted cells by magnetic separation columns, and cultured for 7 days with or without anti-CD40 monoclonal antibodies and IL-4. The culture supernatant was assayed for sCD23 and IL-10 using EIA, and the remaining cells were analysed by flow cytometry. Stimulation with anti-CD40 antibody together with IL-4 increased sCD23 levels and the number of CD23+ cells. The latter was further augmented by depletion of CD8+ cells. This combination of B cell stimulants increased production of IL-10 by PBMC from patients with Graves' disease. The CD40- and IL-4-activated production of IL-10 was decreased by CD8+ cell depletion. In contrast, constitutive production of IL-10 was increased after CD8+ cell depletion in a group of patients with low basal secretion levels (<35 ng/ml). It was, however, decreased in a group with higher basal production levels, but such a relationship was not found in the normal control group. Thus, T cell-dependent B-cell activation via a CD40 pathway activates CD23+ cells, leading to over-production of IL-10 and a shift of the Th1/Th2 balance to Th2 dominance, while CD8+ cells may suppress this activation to counteract the Th2 deviation in Graves' disease.

Adult↗

PubMed2002

Natural killer cell proliferation and circulating cytokines in patients with bilateral basal ganglia calcification.

Ten adult patients with symmetrical calcifications in the bilateral basal ganglia (diagnosed as physiological calcifications) were analyzed for lymphocyte subsets and cytokines. Increased number of natural killer (NK) cells were identified in the peripheral blood of seven patients by lymphocyte subset analysis. Tumor necrosis factor-alpha was detected in the sera of five patients and interferon-gamma was detected in one patient. In summary, NK cell propagation and circulating cytokines, particularly tumor necrosis factor-alpha, may be involved in the etiology of basal ganglia calcification.

Aged↗

PubMed2002

Prognostic value of EEG depression in preterm infants for later development of cerebral palsy.

The aim of this study is to examine the most appropriate timing for EEG recordings in order to predict the risk of cerebral palsy (CP) on the basis of the degree of acute stage abnormalities (ASA) in preterm infants. We retrospectively investigated the correlation between the degree of ASA and psychomotor outcome of 295 infants born between 27 and 32 weeks of gestational age whose initial EEG recording was performed within 7 days of life. Forty-six infants were diagnosed as having CP at 18 months of corrected age, and most of them suffered from diplegia due to periventricular leukomalacia (PVL). The maximum degree of ASA correlated with a later development of CP and its severity. Correlation between the degree of ASA and the severity of CP was highest on day 1 - 2, but this tendency was less clear after day 3. Specificity and negative predictive value were generally high within the first 7 days of life. But sensitivity was markedly decreased after day 3, and positive predictive value was highest on day 2. An EEG on day 1 or 2 will be useful in order to predict developmental outcome of preterm infants on the basis of the grade of ASA.

Acute-Phase Reaction↗

PubMed2002

Mutation induction in human cells after low dose X ray exposure.

Mutations induced after low dose ionising radiation exposure have been intensively analysed not only for radiation risk estimation but also for basic understanding of cellular responses. Human lymphoblastoid TK6-20C cells were irradiated with 100 mGy of X rays and mutation at the heterozygous thymidine kinase (TK) locus was selected by trifluorothymidine (TFT) resistance. Although the mutation frequency at the TK locus increased from 5.6 x 10(-6) to 7.4 x 10(-6), this increase was not statistically significant. However, molecular analysis of TK mutants exhibiting loss of heterozygocity (LOH) demonstrated a clear effect of such low dose IR exposure. Exposure to 100 mGy X ray increased the fraction of hemizygous-LOH from 10% to 42%. In previous experiments, a similar tendency in the increase of hemizygous-LOH was also observed in TK6 cells after exposure to a 2 Gy dose of X rays. This type of LOH can be considered as a result of end-joining repair of DNA double strand breaks.

Cell Line↗

PubMed2002

Cellular responses to low dose heavy-ion exposure in human cells.

The human lymphoblastoid cell line TK6 was used to study the cellular responses after low-dose (100, 200, 500 mGy) or high-dose (3 Gy) of X rays, C (22 keV.micron-1) and Fe (1000 keV.micron-1) ion exposures. p53 protein induction in individual cells was determined by indirect immunofluorescence staining. Cell-cycle progression after heavy-ion exposure was determined by using a laser scanning cytometer. A characteristic pattern of cell-cycle progression was observed with 3 Gy exposure of Fe ions but not with 100 mGy. Similarly such a pattern with 100 mGy C ion exposure did not match that with 3 Gy. The proportion of p53-induced cells is proportional to the probability of cell being hit by a primary heavy ion. The observed low-dose effect can be reflected in the probability of a hit, although detailed nature about their energy deposition must be considered for more precise estimation of such an effect. New detection methodology must be developed for identification of heavy-ion specific cellular responses.

Cell Cycle↗

PubMed2002

Fluorodeoxyglucose uptake and glucose transporter expression in experimental inflammatory lesions and malignant tumours: effects of insulin and glucose loading.

The expression of glucose transporters (GLUTs) and its relationship to fluorodeoxyglucose accumulation in malignant tumours have been well investigated, while such a relation has not been studied in inflammatory lesions. The aim of the present study was to investigate the effects of insulin and glucose loading on the expression of GLUTs in inflammatory lesions and compare them with those in malignant tumours in relation to fluorodeoxyglucose accumulation. All tissue specimens used in this study were obtained in our previous study, in which rats were inoculated with allogenic hepatoma cells (KDH-8), Staphylococcus aureus, or turpentine oil into the left calf muscle and divided into three subgroups: insulin loaded, glucose loaded, and control groups. The expression of glucose transporters (GLUT-1 to GLUT-5) was investigated by immunostaining the lesions (n=5-6, for each group). In all control groups, the expression levels of GLUT-1 and GLUT-3 were significantly higher than those of GLUT-2, GLUT-4 and GLUT-5. Insulin loading did not significantly affect the expression levels of GLUT-1 and GLUT-3 in these lesions except for a significant but slight decrease in the GLUT-1 expression level in the inflammatory lesion of non-infectious origin (89% of the control value). Glucose loading significantly decreased the expression level of GLUT-1 in the inflammatory lesion of non-infectious origin (70% of the control value, P<0.01), and that of GLUT-3 in the inflammatory lesion of infectious origin (70% of the control value, P<0.05), while the expression levels of GLUT-1 and GLUT-3 in the tumour were not significantly affected. These results demonstrate the effects of insulin and glucose loading on the expression level of a molecule (GLUT proteins). The decreased GLUT-1 and GLUT-3 expression levels induced by glucose loading may partly explain the impaired FDG uptake observed in our previous study.

Animals↗