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81.
Morphine sulfate causes immunomodulatory and immunosuppressive effects in human. In this study, the signaling pathway involved in these morphine effects was studied. Addition of morphine sulfate to human CEMx174 lymphocytic cells resulted in increased expression of mitogen-activated protein kinase cascade proteins. Morphine enhanced the cellular levels of ERK1 (44 kDa), ERK2 (42 kDa), a 54-kDa ERK, MEK1 (45 kDa), and MEKK (78 kDa). A time-dependent increase in the activated (Thr and Tyr dually phosphorylated) state of ERK1 and ERK2 was also observed. Naloxone, a morphine antagonist, reversed the observed morphine effects, implicating a micro opioid receptor-mediated process. These findings suggest that mitogen-activated protein kinases are important intermediates in signal transduction pathways initiated by morphine receptors in immune cells.  相似文献   
82.
Several aspects of normal cardiovascular development require signaling by the vitamin A metabolite retinoic acid. We have previously established germ-line mutations in mice in the genes that encode the RAR alpha 1, RAR beta, and RXR alpha retinoic acid receptors as a means of studying the function of these receptors in vivo. Although mutation of RXR alpha results in fetal ventricular defects, the RAR alpha 1 and RAR beta mutations are apparently nonphenotypic in the heart and elsewhere. In this study, we have established and analyzed combinations of these receptor gene mutations. Malformations of the ventricular chamber (chamber hypoplasia and muscular ventricular septal defects), conotruncus (double-outlet right ventricle, transposition, and membranous ventricular septal defects), aortic sac (persistent truncus arteriosus and aorticopulmonary window), and aortic arch-derived arteries were recovered in various combinations of the RAR alpha 1, RAR beta, and RXR alpha gene mutations. Depending on the combination of receptor mutations, selective defects were obtained in specific cardiovascular compartments, suggestive of differential expression or function of each receptor within domains of the developing heart.  相似文献   
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The crystal structure of a blue emission variant (Y66H/Y145F) of the Aequorea victoria green fluorescent protein has been determined by molecular replacement and the model refined. The crystallographic R-factor is 18.1% for all data from 20 to 2.1 A, and the model geometry is excellent. The chromophore is non-native and is autocatalytically generated from the internal tripeptide Ser65-His66-Gly67. The final electron density maps indicate that the formation of the chromophore is complete, including 1,2 dehydration of His66 as indicated by the planarity of the chromophore. The chromophore is in the cis conformation, with no evidence for any substantial fraction of the trans configuration or uncyclized apoprotein, and is well-shielded from bulk solvent by the folded protein. These characteristics indicate that the machinery for production of the chromophore from a buried tripeptide unit is not only intact but also highly efficient in spite of a major change in chromophore chemical structure. Nevertheless, there are significant rearrangements in the hydrogen bond configuration around the chromophore as compared to wild-type, indicating flexibility of the active site. pH titration of the intact protein and the chromopeptide (pKa1 = 4.9 +/- 0.1, pKa2 = 12.0 +/- 0.1) suggests that the predominant form of the chromophore in the intact protein is electrically neutral. In contrast to the wild-type protein [Chattoraj, M., King, B. A., Bublitz, G. U., & Boxer, S. G. (1996) Proc. Natl. Acad. Sci. U.S.A., 8362-8367], femtosecond fluorescence up-conversion spectroscopy of the intact protein and a partially deuterated form strongly suggests that excited-state proton transfer is not coupled to fluorescence emission.  相似文献   
85.
OBJECTIVE: The aim of this study is to compare patients with schizophrenia with their relatives and the general public in their attitudes towards schizophrenic psychotic symptoms. METHOD: We used a case vignette depicting a person with typical schizophrenic psychotic symptoms and compared the attitudes of 44 inpatients and 47 outpatients with schizophrenia, 48 of their relatives and 43 members of the general public. We also compared the attitudes of patients with schizophrenia to their own symptoms and the symptoms described in the vignette. RESULTS: Subjects from the general public tended not to recognise psychotic symptoms as features of mental illness and tended not to consider drug treatment and hospitalisation as required. Sex, education level as well as previous contact with the mentally ill were found to be significant determinants of attitude. The levels of symptom awareness in patients with schizophrenia and their relatives are higher but still relatively low. In addition, we found that patients with schizophrenia who correctly appraised psychotic symptoms in another person were also aware of their own mental symptoms and need of treatment. CONCLUSIONS: The level of recognition of psychotic symptoms and awareness of a need for treatment are low in the general public, as well as in patients with schizophrenia and their relatives. These findings are discussed in relation to the assessment of insight in patients and a need for psychoeducational programs for each group.  相似文献   
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DNA superhelical tension, an important feature of genomic organization, is known to affect the interactions of intercalating molecules with DNA. However, the effect of torsional tension on nonintercalative DNA-binding chemicals has received less attention. We demonstrate here that the enediyne calicheamicin gamma1I, a strand-breaking agent specific to the minor groove, causes approximately 50% more damage in negatively supercoiled plasmid DNA than in DNA with positive superhelicity. Furthermore, we show that the decrease in damage in positively supercoiled DNA is controlled at the level of thiol activation of the drug. Our results suggest that supercoiling may affect both the activity of nonintercalating genotoxins in vivo and the accessibility of glutathione and other small physiologic molecules to DNA-bound chemicals or reactions occurring in the grooves of DNA.  相似文献   
88.
Five different PCR methods for the detection of Helicobacter pylori were evaluated. The results of this study indicate that of the five PCR methods examined, the ureC (glmM) gene PCR is the most sensitive and specific for the detection of H. pylori in gastric biopsy specimens.  相似文献   
89.
Sleep disruption, nightly restlessness, sundowning, and other circadian disturbances are frequently seen in Alzheimer's disease (AD) patients. Changes in the suprachiasmatic nucleus and pineal gland are thought to be the biological basis for these behavioral disturbances. Melatonin is the main endocrine message for circadian rhythmicity from the pineal. To determine whether melatonin production was affected in AD, melatonin levels were determined in the cerebrospinal fluid (CSF) of 85 patients with AD (mean age, 75 +/- 1.1 yr) and in 82 age-matched controls (mean age, 76 +/- 1.4 yr). Ventricular postmortem CSF was collected from clinically and neuropathologically well defined AD patients and from control subjects without primary neurological or psychiatric disease. In old control subjects (>80 yr of age), CSF melatonin levels were half of those in control subjects of 41-80 yr of age [176 +/- 58 (n = 29) and 330 +/- 66 (n = 53) pg/mL, respectively; P = 0.016]. We did not find a diurnal rhythm in CSF melatonin levels in control subjects. In AD patients the CSF melatonin levels were only one fifth (55 +/- 7 pg/mL) of those in control subjects (273 +/- 47 pg/mL; P = 0.0001). There was no difference in the CSF melatonin levels between the presenile (42 +/- 11 pg/mL; n = 21) and the senile (59 +/- 8 pg/mL; n = 64; P = 0.35) AD patients. The melatonin level in AD patients expressing apolipoprotein E-epsilon3/4 (71 +/- 11 pg/mL) was significantly higher than that in patients expressing apolipoprotein E-epsilon4/4 (32 +/- 8 pg/ml; P = 0.02). In the AD patients no significant correlation was observed between age of onset or duration of AD and CSF melatonin levels. In the present study, a dramatic decrease in the CSF melatonin levels was found in old control subjects and even more so in AD patients. Whether supplementation of melatonin may indeed improve behavioral disturbances in AD patients should be investigated.  相似文献   
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