146 research outputs found
Specific down-regulation of spinal μ-opioid receptor and reduced analgesic effects of morphine in mice with postherpetic pain
The analgesic effects of opioid agonists and the expression of μ-and κ-opioid receptors were compared between mice with herpetic pain and those with postherpetic pain induced by herpetic virus inoculation. Morphine inhibited herpetic pain more effectively than postherpetic pain. Intrathecal injection reduced the analgesic effects of morphine on postherpetic pain, but intracerebroventricular injection did not. The κ-opioid receptor agonist nalfurafine suppressed herpetic and postherpetic pain to similar degrees. μ-Opioid receptor-like immunoreactivities in the lumbar dorsal horn were markedly decreased at the postherpetic, but not herpetic, stage of pain. In the dorsal root ganglia, the expression of μ-opioid receptor mRNA was significantly decreased in mice with postherpetic pain, whereas the κ-opioid receptor mRNA level was not altered. These results suggest that specific down-regulation of the μ-opioid receptor in the primary sensory neurons is responsible for the reduced analgesic action of morphine on postherpetic pain. The κ-opioid receptor may be a useful target for the analgesic treatment of postherpetic neuralgia
Deficiency in Galectin-3 Promotes Hepatic Injury in CDAA Diet-Induced Nonalcoholic Fatty Liver Disease
Nonalcoholic fatty liver disease (NAFLD) is increasingly recognized as a condition in which excess fat accumulates in hepatocytes. Nonalcoholic steatohepatitis (NASH), a severe form of NAFLD in which inflammation and fibrosis in the liver are noted, may eventually progress to end-stage liver disease. Galectin-3, a β-galactoside-binding animal lectin, is a multifunctional protein. This protein is involved in inflammatory responses and carcinogenesis. We investigated whether galectin-3 is involved in the development of NASH by comparing galectin-3 knockout (gal3−/−) mice and wild-type (gal3+/+) mice with choline-deficient L-amino-acid-defined (CDAA) diet-induced NAFLD/NASH. Hepatic injury was significantly more severe in the gal3−/− male mice, as compared to the gal3+/+ mice. Data generated by microarray analysis of gene expression suggested that galectin-3 deficiency causes alterations in the expression of various genes associated with carcinogenesis and lipid metabolism. Through canonical pathway analysis, involvement of PDGF and IL-6 signaling pathways was suggested in galectin-3 deficiency. Significant increase of CD14, Fos, and Jun, those that were related to lipopolysaccharide-mediated signaling, was candidate to promote hepatocellular damages in galectin-3 deficiency. In conclusion, galectin-3 deficiency in CDAA diet promotes NAFLD features. It may be caused by alterations in the expression profiles of various hepatic genes including lipopolysaccharide-mediated inflammation
Japanese Encephalitis Virus in Meningitis Patients, Japan
Cerebrospinal fluid specimens from 57 patients diagnosed with meningitis were tested for Japanese encephalitis virus. Total RNA was extracted from the specimens and amplified. Two products had highest homology with Nakayama strain and 2 with Ishikawa strain. Results suggest that Japanese encephalitis virus causes some aseptic meningitis in Japan
Novel transcript profiling of diffuse alveolar damage induced by hyperoxia exposure in mice: Normalization by glyceraldehyde 3-phosphate dehydrogenase
Under mechanical ventilation with high-inspired oxygen concentration, diffuse
alveolar damage (DAD) was found to take place in some patients. To clarify the
molecular pathophysiology of this condition we investigated the time course of gene
expression changes induced by hyperoxia exposure in mouse lung using real-time
quantitative polymerase chain reaction (real-time qPCR). Our results normalized by
glyceraldehyde 3-phosphate dehydrogenase showed that mRNA levels of cysteine rich
protein 61 (CYR61) and connective tissue growth factor (CTGF) were significantly
up-regulated, while those of surfactant-associated protein C (SFTPC), cytochrome
P450, 2F2 (CYP2F2), Claudin 1, (CLDN1), membrane-associated zonula occludens
protein-1 (ZO-1), lysozyme (LYZS), and P lysozyme structural (LZP-S) were
significantly down-regulated. Increasing level of mRNAs, each encoding CYR61 and
CTGF, suggests a serious risk of fibrosing alveolitis. Decrease in levels of mRNAs for
SFTPC, CYP2F2, CLDN1, ZO-1, LYZS, and LZP-S suggests alveolar dysfunction
and disruption of the immune system. Moreover we confirmed apoptotic conditions,
such as significant up-regulations of mRNA levels in Myc and Galectin-3. Hyperoxic
condition probably yielded reactive oxygen species (ROS), which resulted in a malignant cycle of ROS production by Myc overexpression
T-cell Responses to Dengue Virus in Humans
Dengue virus (DENV) is a leading cause of morbidity and mortality in most tropical and subtropical areas of the world. Dengue virus infection induces specific CD4+CD8– and CD8+CD4– T cells in humans. In primary infection, T-cell responses to DENV are serotype cross-reactive, but the highest response is to the serotype that caused the infection. The epitopes recognized by DENV-specific T cells are located in most of the structural and non-structural proteins, but NS3 is the protein that is most dominantly recognized. In patients with dengue hemorrhagic fever (DHF) caused by secondary DENV infection, T cells are highly activated in vivo. These highly activated T cells are DENV-specific and oligoclonal. Multiple kinds of lymphokines are produced by the activated T cells, and it has been hypothesized that these lymphokines are responsible for induction of plasma leakage, one of the most characteristic features of DHF. Thus, T-cells play important roles in the pathogenesis of DHF and in the recovery from DENV infection
Dynamics of cellular immune responses in the acute phase of dengue virus infection.
In this study, we examined the dynamics of cellular immune responses in the acute phase of dengue virus (DENV) infection in a marmoset model. Here, we found that DENV infection in marmosets greatly induced responses of CD4/CD8 central memory T and NKT cells. Interestingly, the strength of the immune response was greater in animals infected with a dengue fever strain than in those infected with a dengue hemorrhagic fever strain of DENV. In contrast, when animals were re-challenged with the same DENV strain used for primary infection, the neutralizing antibody induced appeared to play a critical role in sterilizing inhibition against viral replication, resulting in strong but delayed responses of CD4/CD8 central memory T and NKT cells. The results in this study may help to better understand the dynamics of cellular and humoral immune responses in the control of DENV infection
Novel Dengue Virus Type 1 from Travelers to Yap State, Micronesia
Dengue virus type 1 (DENV-1), which was responsible for the dengue fever outbreak in Yap State, Micronesia, in 2004, was isolated from serum samples of 4 dengue patients in Japan. Genome sequencing demonstrated that this virus belonged to genotype IV and had a 29-nucleotide deletion in the 3´ noncoding region
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