PURPOSE: It has been suggested that the pineal hormone melatonin(MEL) protects neurons in vitro from excitotoxicity mediated by kainate-sensitive glutamate receptors and from oxidative stress-induced DNA damage and apoptosis. The present study evaluated the antioxidatives and anti-inflammatory effect of melatonin on kainic acid(KA)-induced neuronal injury in the hippocampus in vivo. METHODS: 30 adult male Sprague-Dawley rats were divided into two equal groups. Control group was treated with KA only and test group was treated with KA and MEL. We injected 10 mg/kg KA intraperitoneal into rats. This results in selective neuronal injury accompanied by intense microglial activation and triggers DNA damage in the hippocampus. We tested the in vivo efficacy of MEL in preventing KA-induced neuronal injury and neuroinflammation in the hippocampus. MEL(2.5 mg/kg) was injected i.p. four times : 20 min before KA, immidiately after, and 1 and 2 h after the KA. Rats were sacrificed 72 h later and their hippocampi were examined for evidence of DNA damage (in situ dUTP-end-labeling, i.e. TUNEL staining), cell viability(H&E staining), microglial (isolectin-B4 histochemistry), astroglial responses(glial fibrillary acidic protein, GFAP immunohistochemistry), and lipid peroxidation(4-hydroxynonenal immunohistochemistry). RESULTS: The cumulative dose of 10 mg/kg MEL attenuates KA-induced neuronal death as well as microglial activation and lessens DNA breaks. CONCLUSION: A possible mechanism of MEL-provided neuroprotection lies in its antioxidant and anti-inflammatory action. Present data suggest that MEL holds potential for the treatment of acute brain pathologies such as epilepsy-associated brain damage, stroke, and brain trauma.
Adult ; Animals ; Apoptosis ; Brain ; Brain Injuries ; DNA Breaks ; DNA Damage ; Epilepsy ; Hippocampus ; Humans ; In Situ Nick-End Labeling ; Kainic Acid ; Male ; Melatonin* ; Neurons* ; Pathology ; Rats ; Rats, Sprague-Dawley ; Receptors, Glutamate ; Stroke

BACKGROUND: This study was done to assess the feasibility of dendritic cell generation from murine bone marrow and the efficacy of dendritic cells pulsed with total RNA to induce specific cytotoxic T lymphocyte response against leukemic cells. METHODS: Nucleated cells of inbred BALB/c mice were obtained and cultured with granulocyte/macrophage colony-stimulating factor (GM-CSF) and lipopolysaccharide (LPS) to induce dendritic cells. Total RNA of WEHI-3BD+, a myelomonocytic leukemia cell line from BALB/c, was transfected into the dendritic cells using liposome. RNA pulsed dendritic cells were irradiated and administered to the BALB/c mice intraperitoneally and splenic T lymphocytes were harvested. After restimulation with leukemic cells, T cell proliferation and specific cytotoxicity was assessed. RESULTS: Cells cultured with GM-CSF and lipopolysaccaride were found to have prominent dendritic processes. The percentage of cells showing high expression of both MHC class II and CD80, CD86, or CD11c was 69.6 %, 63.7%, and 41.8%, respectively. T cells stimulated by WEHI-3BD+ total RNA pulsed dendritic cells using DOTAP showed enhanced proliferation than those stimulated by total RNA or media only (P=0.05). When T cells were cocultured with WEHI-3BD+ as target cells, T cells stimulated by WEHI-3BD+ total RNA pulsed dendritic cells using DOTAP showed much increased cytotoxicity than controls. CONCLUSION: Dendritic cells pulsed with total leukemic RNA could stimulate T cells to induce specific cytotoxic effect.
Animals ; Bone Marrow ; Cell Line ; Cell Proliferation ; Colony-Stimulating Factors ; Dendritic Cells* ; Granulocyte-Macrophage Colony-Stimulating Factor ; Leukemia ; Liposomes ; Lymphocytes ; Mice ; RNA* ; T-Lymphocytes ; T-Lymphocytes, Cytotoxic*

Among several animal models of retinitis pigmentosa (RP), the more recently developed rd10 mouse with later onset and slower rate of retinal degeneration than rd1 mouse is a more suitable model for testing therapeutic modalities. We therefore investigated the time course of retinal degeneration in rd10 mice before adopting this model in our interventional studies. Electroretinogram (ERG) recordings were carried out in postnatal weeks (PW) 3~5 rd10 (n=23) and wild-type (wt) mice (n=26). We compared the amplitude and implicit time of the b-wave of ERG records from wt and rd10 mice. Our results showed that b-wave amplitudes in rd10 mice were significantly lower and the implicit time of b-waves in rd10 mice were also significantly slower than that in wt mice (20~160 microV vs. 350~480 microV; 55~75 ms vs. 100~150 ms: p<0.001) through PW3 to PW5. The most drastic changes in ERG amplitudes and latencies were observed during PW3 to PW4. In multichannel recording of rd10 retina in PW2 to PW4.5, we found no significant difference in mean spike frequency, but the frequency of power spectral peak of local field potential at PW3 and PW3.5 is significantly different among other age groups (p<0.05). Histologic examination of rd10 retinae showed significant decrease in thickness of the outer nuclear layer at PW3. TUNEL positive cells were most frequently observed at PW3. From these data, we confirm that in the rd10 mouse, the most precipitous retinal degeneration occurs between PW3~PW4 and that photoreceptor degeneration is complete by PW5.
Animals ; Humans ; In Situ Nick-End Labeling ; Mice ; Models, Animal ; Retina ; Retinal Degeneration ; Retinaldehyde ; Retinitis ; Retinitis Pigmentosa

Various cell types in higher multicellular organisms are genetically homogenous, but are functionally and morphologically heterogeneous due to the differential expression of genes during development, which appears to be controlled by epigenetic mechanisms. However, the exact molecular mechanisms that govern the tissue-specific gene expression are poorly understood. Here, we show that dynamic changes in histone modifications and DNA methylation in the upstream coding region of a gene containing the transcription initiation site determine the tissue-specific gene expression pattern. The tissue-specific expression of the transgene correlated with DNA demethylation at specific CpG sites as well as significant changes in histone modifications from a low ratio of methylated H3- lysine 4 or acetylated H3-lysine 9, 14 to acetylated H4 to higher ratios. Based on the programmed status of transgene silenced in cloned mammalian ear-derived fibroblasts, the transgene could be reprogrammed by change of histone modification and DNA methylation by inhibiting both histone deacetylase and DNA methylation, resulting in high expression of the transgene. These findings indicate that dynamic change of histone modification and DNA methylation is potentially important in the establishment and maintenance of tissue-specific gene expression.
Transgenes/*genetics ; Swine ; Organ Specificity/genetics ; Methylation ; Lysine/*metabolism ; Histones/*metabolism ; Histone Deacetylases/metabolism ; Gene Silencing ; *Gene Expression ; Fibroblasts ; Ear ; *DNA Methylation ; Cells, Cultured ; Animals, Genetically Modified ; Animals ; Acetylation

PURPOSE: Nutritional therapy (NT), such as enteral nutrition (EN) or parenteral nutrition (PN), is essential for the malnourished patients. Although the complications related to NT has been well described, multicenter data on symptoms in the patients with receiving NT during hospitalization are still lacking. METHODS: Nutrition support team (NST) consultations, on which NT-related complications were described, were collected retrospectively for one year. The inclusion criteria were patients who were (1) older than 18 years, (2) hospitalized, and (3) receiving EN or PN at the time of NST consultation. The patients' demographics (age, sex, body mass index [BMI]), type of NT and type of complication were collected. To compare the severity of each complication, the intensive care unit (ICU) admission, hospital stay, and type of discharge were also collected. RESULTS: A total of 14,600 NT-related complications were collected from 13,418 cases from 27 hospitals in Korea. The mean age and BMI were 65.4 years and 21.8 kg/m2. The complications according to the type of NT, calorie deficiency (32.4%, n=1,229) and diarrhea (21.6%, n=820) were most common in EN. Similarly, calorie deficiency (56.8%, n=4,030) and GI problem except for diarrhea (8.6%, n=611) were most common in PN. Regarding the clinical outcomes, 18.7% (n=2,158) finally expired, 58.1% (n=7,027) were admitted to ICU, and the mean hospital days after NT-related complication were 31.3 days. Volume overload (odds ratio [OR]=3.48) and renal abnormality (OR=2.50) were closely associated with hospital death; hyperammonemia (OR=3.09) and renal abnormality (OR=2.77) were associated with ICU admission; “micronutrient and vitamin deficiency” (geometric mean [GM]=2.23) and volume overload (GM=1.61) were associated with a longer hospital stay. CONCLUSION: NT may induce or be associated with several complications, and some of them may seriously affect the patient's outcome. NST personnel in each hospital should be aware of each problem during nutritional support.
Adult ; Body Mass Index ; Demography ; Diarrhea ; Enteral Nutrition ; Hospitalization ; Humans ; Hyperammonemia ; Intensive Care Units ; Korea ; Length of Stay ; Multicenter Studies as Topic ; Nutrition Therapy ; Nutritional Support ; Parenteral Nutrition ; Referral and Consultation ; Retrospective Studies ; Vitamins