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51.
EH Herman J Zhang BB Hasinoff KT Tran DP Chadwick JR Clark VJ Ferrans 《Canadian Metallurgical Quarterly》1998,128(1):35-52
We have determined the time course, the spatial spread in brain tissue, and the intracellular distribution of biotin- and fluorescein-labeled phosphorothioate oligodeoxynucleotides (ODNs) following single injections into the rat striatum or the lateral ventricle. These time and space parameters were correlated with the ability of c-fos phosphorothioate antisense ODNs to suppress the induction of Fos protein by cocaine. A rapid and dose-dependent tissue penetration of labeled ODNs was observed following either intrastriatal or intraventricular injections of a constant sample volume. Inspection of tissue sections by confocal microscopy uncovered a distinct change in the intracellular disposition of labeled ODNs during the 24 h post-injection period. At 1, 6 and 12 h, the vast majority of the fluorescent signal was confined to the interstitial spaces throughout the zone penetrated by ODNs. Neuronal nuclei displayed faint labeling along the outer portion of the nucleus at 1 and 6 h post-injection. At these time-points, ODNs were not detected in the cytoplasm. By 16 h, ODNs were barely detectable in the extracellular space and absent from neuronal nuclei. Instead, ODNs were seen in large cytoplasmic granules of neurons throughout the tissue zone penetrated by the ODNs. Experiments with intrastriatal injections of antisense ODNs to c-fos mRNA revealed Fos suppression between 3 and 12 h, but not at 16 and 24 h. This combined analysis has revealed that (1) restricted tissue penetration by ODNs limits their antisense effects on protein expression, and (2) depletion of extracellular ODNs and sequestration of c-fos antisense ODNs into large intracellular granules coincides with the loss of their biological activity. 相似文献
52.
53.
VJ Di Maio 《Canadian Metallurgical Quarterly》1998,18(2):189-201
To investigate the roles of astroglial cells, we targeted their ablation genetically. Transgenic mice were generated expressing herpes simplex virus thymidine kinase from the mouse glial fibrillary acidic protein (GFAP) promoter. In adult transgenic mice, 2 weeks of subcutaneous treatment with the antiviral agent ganciclovir preferentially ablated transgene-expressing, GFAP-positive glia from the jejunum and ileum, causing a fulminating and fatal jejuno-ileitis. This pathology was independent of bacterial overgrowth and was characterized by increased myeloperoxidase activity, moderate degeneration of myenteric neurons, and intraluminal hemorrhage. These findings demonstrate that enteric glia play an essential role in maintaining the integrity of the bowel and suggest that their loss or dysfunction may contribute to the cellular mechanisms of inflammatory bowel disease. 相似文献
54.
DW Reid VJ Hendrick TC Aitken WT Berrill SC Stenton DJ Hendrick 《Canadian Metallurgical Quarterly》1998,12(5):1079-1083
OBJECTIVE: To test the usefulness of a commercial DNA hybridization assay for the detection of high-risk (HR) human papillomavirus (HPV) types in archival cervical smears and to compare the sensitivity with that of polymerase chain reaction (PCR) using consensus primers. STUDY DESIGN: Stained material was scraped from archival slides and the pellet volume noted. DNA was extracted using silica/guanidinium isothiocyanate and the quality checked by amplification of the beta-globin gene. HR-HPV DNA was detected using a commercial hybrid capture assay (HCA) and the results compared with an in-house amplification system with consensus primers. RESULTS: Of 156 archival smears stored for 12-13 years, 20 were positive by HCA using an HR probe cocktail. Ninety-eight were also tested by PCR, and 35 were positive. The percentage of HPV-positive samples increased with the increasing size of the pellet. HR-HCA detected more positives in samples with high grade squamous intraepithelial lesion (moderate/severe dyskaryosis). CONCLUSION: Both hybridization by HCA and amplification by PCR could be used to detect genital HPV in archival smears. The general primers PCR detected more positives than HR-HCA but included HPV 6/11. While variation in sample size and prolonged storage may reduce the quality of DNA, the use of archival material for longitudinal studies of HPV presence is potentially worthwhile. 相似文献
55.
A number of cellular proteins have been identified as caspase targets during cell death, including the PITSLRE protein kinases. These targets generally fall into one of three possible categories: 1) other caspases, 2) proteins that are inactivated during apoptosis, and 3) proteins that are required for execution of the cell death program. However, not all proteins are cleaved by caspases during apoptosis. Why only specific proteins are destined to be processed by caspases during cell death is currently not clear. Here we show that multiple caspase-like activities are involved in the processing of the PITSLRE p110 isoforms during Fas-induced apoptosis in Jurkat T-cells. Three p110 caspase cleavage sites have been mapped to the amino-terminal domain of p110 and verified by site-directed mutagenesis. Curiously, the mutagenesis studies revealed that cleavage of two juxtaposed caspase sites is necessary for the complete processing of this protein during cell death in vivo. Finally, we demonstrate that the PITSLRE p110 protein is rapidly phosphorylated during Fas-induced apoptosis in Jurkat cells and that phosphorylation of an amino-terminal portion of the protein may enhance caspase cleavage in this region. 相似文献
56.
57.
Tubercles, spines and sensory receptors are the most studied structures of adult male worms of Schistosoma mansoni isolated in other countries. The purpose of this investigation was to properly define these structures in Brazilian worms. Specimens 7-8 weeks after infection were recovered from albino SW mice and from a wild rodent (Nectomys squamipes) and processed for scanning electron microscopy studies. Photomicrographs of the anterior region with the aspects related to the outer and inner regions of both suckers were considered. The ventral portion of the middle region was represented by the anterior of gynaecophoric canal while the dorsal surface was studied in its ventral and dorsal regions mainly focusing the aspect of the tubercles, spines and sensorial papillae. The outer surface of the oral sucker is spiny and spines are bigger, sharp with sensory receptors in their posterior edge. Tubercles with spines or receptors are more concentrated in the middle region and in one of the margins of the gynaecophoric canal. An excretory pore-like structure in the posterior portion was observed. The gynaecophoric canal has few sensory structures, spines broadened in their mid-region and are sharp pointed at the distal end. It was concluded that the presently studied characters are similar to those previously reported. 相似文献
58.
M Mann JH Shelhamer H Masur VJ Gill W Travis D Solomon J Manischewitz F Stock HC Lane FP Ognibene 《Canadian Metallurgical Quarterly》1997,155(5):1723-1728
This study assessed the presence of cytomegalovirus (CMV) in bronchoalveolar lavage (BAL) in three subpopulations of HIV-infected patients and correlated its presence with clinical status during 3 mo of follow-up. Nineteen asymptomatic volunteers, six patients with CMV retinitis, and 46 patients with acute pulmonary symptoms underwent BAL and were assessed for CMV by cytopathology, conventional shell vial cultures, and antigen detection. Transbronchial biopsies were also obtained when possible and evaluated for histopathologic changes of CMV. All patients were followed for approximately 3 mo. Cytomegalovirus was detected in BAL in nine of 19 (47%) asymptomatic volunteers, in all six patients with CMV retinitis, and in 33 of 46 (72%) patients with pulmonary symptoms. Only one symptomatic patient with a positive CMV BAL culture developed clinically significant CMV pulmonary disease; this patient developed disseminated CMV and died. The only other death occurred in a patient with CMV retinitis who developed staphylococcal bacteremia. None of the asymptomatic volunteers or patients with CMV retinitis developed evidence of CMV pneumonia or any other organ disease with CMV. Cytomegalovirus is frequently detected in BAL from HIV-infected patients regardless of their pulmonary symptoms and its presence does not clinically predict significant pulmonary morbidity or mortality in 3 mo of follow-up. 相似文献
59.
Georgiadis N. Rubinstein M. Uman M.A. Medelius P.J. Thomson E.M. 《Electromagnetic Compatibility, IEEE Transactions on》1992,34(4):451-460
Lightning-induced voltages due to return strokes in ground flashes beyond about 5 km were measured simultaneously at both ends of an unenergized 448-m power-distribution line. The measurements represent an extension of an earlier experiment on the same line in which voltages are obtained at only one end of the line. In addition to the induced voltage measurements, the causative lightning electric and magnetic fields are recorded. The voltage and field measurements are made as a function of the lightning direction and of the power-line termination. For both measured and idealized electric fields as inputs to a time-domain transmission-line coupling model, the authors calculate line voltages as a function of the incident angle of the lightning electromagnetic radiation and of the line termination. Measured and predicted voltages calculated from the coupling model with measured fields as inputs show, overall, good agreement in waveshape, but the predicted voltages are about a factor of three larger in amplitude. To the extent that the results can be compared, there is reasonable agreement with the earlier experiments on the same line 相似文献
60.
FL van Buchem JA Knottnerus VJ Schrijnemaekers MF Peeters 《Canadian Metallurgical Quarterly》1997,349(9053):683-687
BACKGROUND: The value of antibiotics in acute rhinosinusitis is uncertain. Although maxillary sinusitis is commonly diagnosed and treated in general practice, no effectiveness studies have been done on unselected primary-care patients. We used a randomised, placebo-controlled design to test the hypothesis that there would be an improvement associated with amoxycillin treatment for acute maxillary sinusitis patients presenting to general practice. METHODS: Adult patients with suspected acute maxillary sinusitis were referred by general practitioners for radiographs of the maxillary sinus. Those with radiographic abnormalities (n = 214) were randomly assigned treatment with amoxycillin (750 mg three times daily for 7 days; n = 108) or placebo (n = 106). Clinical course was assessed after 1 week and 2 weeks, and reported relapses and complications were recorded during the following year. FINDINGS: After 2 weeks, symptoms had improved substantially or disappeared in 83% of patients in the study group and 77% of patients taking placebo. Amoxycillin did not influence the clinical course of maxillary sinusitis nor the frequency of relapses during the 1-year follow-up. Radiographs had no prognostic value, nor were they an effect modifier. Side-effects were recorded in 28% of patients given amoxycillin and in 9% of those taking placebo (p < 0.01). The occurrence of relapses was similar in both groups (21 vs 17%) during the follow-up year. INTERPRETATION: Antibiotic treatment did not improve the clinical course of acute maxillary sinusitis presenting to general practice. For these patients, an initial radiographic examination is not necessary and initial management can be limited to symptomatic treatment. Whether antibiotics are necessary in more severe cases warrants further study. 相似文献