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Shi R, Qiao X, Emerson N, Malcom A. Dimethylsulfoxide enhances CNS neuronal plasma membrane resealing after injury in low temperature or low calcium. JOURNAL OF NEUROCYTOLOGY 2001; 30:829-39. [PMID: 12165673 DOI: 10.1023/a:1019645505848] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
The inability to repair the damaged membrane may be one of the key mechanisms underlying the severe neuronal degeneration and overall functional loss seen in in vivo spinal cord injury and traumatic axonal injury in blunt head trauma. Promoting membrane resealing following damage may therefore constitute a potential effective therapeutic intervention in treating head trauma and spinal cord injuries. In our previous studies, we have shown that the axolemma failed to reseal following transection in clinically related situations, such as low extracellular calcium and low temperature. Our current studies indicate that DMSO is capable of rendering significant improvement in guinea pig axonal membrane resealing following transection in both 0.5 mM [Ca(2+)](0) and 25 degrees C situations. This was demonstrated physiologically by monitoring membrane potential recovery and anatomically by conducting HRP-exclusion assays 60 minutes after injury. Further, we have shown that the addition of DMSO in normal Krebs' solution (2 mM [Ca(2+)](0) and 37 degrees C) resulted in a decrease in membrane repair following injury. This indicates that DMSO-mediated membrane repair is sensitive to temperature and calcium. This study suggests the role of DMSO in axonal membrane resealing in clinically relevant conditions and raises the possibility of using DMSO in combination with other more established therapies in spinal cord injury treatment.
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Shi R, Borgens RB. Anatomical repair of nerve membranes in crushed mammalian spinal cord with polyethylene glycol. ACTA ACUST UNITED AC 2001; 29:633-43. [PMID: 11353287 DOI: 10.1023/a:1010879219775] [Citation(s) in RCA: 82] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Acute damage to axons is manifested as a breach in their membranes, ion exchange across the compromised region, local depolarization, and sometimes conduction block. This condition can worsen leading to axotomy. Using a novel recording chamber, we demonstrate immediate arrest of this process by application of polyethylene glycol (PEG) to a severe compression of guinea pig spinal cord. Variable magnitudes of compound actions potentials (CAPs) were rapidly restored in 100% of the PEG-treated spinal cords. Using a dye exclusion test, in which horseradish peroxidase is imbibed by damaged axons, we have shown that the physiological recovery produced by polyethylene glycol was associated with sealing of compromised axolemmas. Injured axons readily imbibe horseradish peroxidase-but not following sealing of their membranes. The density of nerve fibers taking up the marker is significantly reduced following polyethylene glycol treatment compared to a control group. We further show that all axons-independent of their caliber-are equally susceptible to the compression injury and equally susceptible to polyethylene glycol mediated repair. Thus, polyethylene glycol-induced reversal of permeabilization by rapid membrane sealing is likely the basis for physiological recovery in crushed spinal cords. We discuss the clinical importance of these findings.
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Zhang X, Liu XJ, Wu Q, Shi R, Gao R, Liu Y, Hu S, Tian Y, Guo S, Fang W. Clinical outcome of patients with previous myocardial infarction and left ventricular dysfunction assessed with myocardial (99m)Tc-MIBI SPECT and (18)F-FDG PET. J Nucl Med 2001; 42:1166-73. [PMID: 11483675] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/21/2023] Open
Abstract
UNLABELLED Myocardial viability was assessed by (99m)Tc-methoxyisobutylisonitrile (MIBI) SPECT and (18)F-FDG PET to evaluate the prognosis and treatment strategy of patients with myocardial infarction (MI) and left ventricular (LV) dysfunction. METHODS One hundred twenty-three consecutive patients with previous MI and LV dysfunction (LV ejection fraction [EF], 35% +/- 6% [mean +/- SD]) who underwent (99m)Tc-MIBI SPECT and FDG PET were followed-up for 26 +/- 10 mo (mean +/- SD). Distributions of the 2 radiotracers in myocardial segments were classified into 2 patterns: myocardial perfusion-metabolism mismatch (MM) and match (M). LV EF and LV end-diastolic diameter (EDD) were measured by echocardiography at baseline, 3 mo (Pos1), and 6 mo (Pos2) after revascularization. Cardiac death, acute MI, unstable angina, and late revascularization (>3 mo) experienced by the patients during follow-up were defined as cardiac events. RESULTS Sixty-seven patients underwent revascularization and 56 patients were treated medically. Of the 72 patients with > or =2 MM segments, 42 underwent revascularization (group A1) and 30 were treated medically (group A2). Of the 51 patients with <2 MM segments, 25 underwent revascularization (group B1) and 26 were treated medically (group B2). The 4 groups had similar baseline characteristics and rest LV EF. After revascularization, EF (mean +/- SD) increased in group A1 from 36% +/- 5% to 44% +/- 8% (P < 0.0001) in Pos1 and to 51% +/- 9% (P < 0.0001) in Pos2. EDD (mean +/- SD) decreased from 62 +/- 8 mm to 56 +/- 5 mm (P < 0.001) in Pos1 and to 55 +/- 5 mm (P < 0.001) in Pos2. However, EF and EDD were unchanged in group B1 (P > 0.05). During the follow-up, 22 patients (17.9%) suffered from cardiac events, including 11 cardiac deaths, 4 acute MI, 6 late coronary artery bypass grafting, and 1 unstable angina pectoris. The cardiac event rate in group A2 (50%) was significantly higher than that of groups A1 (2.4%; chi(2) = 23.08; P < 0.0001), B1 (12%; chi(2) = 8.94; P = 0.003), and B2 (11.5%; chi(2) = 9.45; P = 0.002). CONCLUSION Assessment of myocardial viability using hybrid (99m)Tc-MIBI SPECT and FDG PET can predict the clinical outcome and is helpful to decision making in the treatment strategy of patients with MI and LV dysfunction. Revascularization can improve the LV function and clinical outcome of patients with >2 viable myocardial segments.
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Yu L, Shi R, Sun Y, Tang J, Wang Q. [Plasma cell granuloma of maxillary sinuses]. LIN CHUANG ER BI YAN HOU KE ZA ZHI = JOURNAL OF CLINICAL OTORHINOLARYNGOLOGY 2001; 15:352-3. [PMID: 12541900] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/28/2023]
Abstract
OBJECTIVE To study the clinical features and treatment of plasma cell granuloma in maxillary sinuses. METHOD The clinical information of 3 cases was reported and the literatures were also reviewed. RESULT All of the 3 cases were cured after Caldwell-Luc operation combined with oral corticosteroids and antiallergic agent. Recurrence hasn't been found in half to 2 years follow-up period. CONCLUSION Plasma cell granuloma of maxillary sinus is a chronic inflammatory lesion with unknown origin. In almost all of the cases, CT images showed some degree of involvement of the bony wall of the maxillary sinuses. The imaging findings mimicker malignant tumors. But the prognosis were quite well in most of the patients.
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Berkel HJ, Turbat-Herrera EA, Shi R, de Benedetti A. Expression of the translation initiation factor eIF4E in the polyp-cancer sequence in the colon. Cancer Epidemiol Biomarkers Prev 2001; 10:663-6. [PMID: 11401917] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/20/2023] Open
Abstract
The eukaryotic translation initiation factor 4E (eIF4E) has been shown to play a key role in cell growth, and several studies have documented an increased expression of eIF4E in a number of solid tumors, including breast, bladder, cervical, and head and neck cancers. This study was done to evaluate the potential role of eIF4E in the polyp-cancer sequence in the colorectum. Eighty-seven cases with lesions in the colorectum with a variety of histopathological diagnoses were randomly selected from the archives of the Pathology Department at Louisiana State University Health Sciences Center-Shreveport. Appropriate sections were selected for immunostaining with eIF4E. The medical records of the patients were reviewed, and demographic information was collected. All statistical analyses were performed using SAS software. A statistically significant relationship was found between the level of eIF4E expression and histological type of lesion: the lowest level of eIF4E expression was found in normal colon tissue, whereas the highest level of eIF4E expression was found in colorectal adenocarcinomas. Carcinomatous lesions were found to have a 43 times higher chance of having a high level of eIF4E expression compared with normal tissue (95% confidence interval, 8.0-213.6, P < 0.0001). In a multivariate analysis, histological type was the only variable that showed a significant relationship with eIF4E expression; no effect was found due to age, gender, race, history of polyps, and family history. The results from this study are consistent with other data from the literature and support the suggestion that eIF4E is strongly involved in colon tumorigenesis. eIF4E might be a useful intermediate biomarker for use in chemoprevention intervention studies in patients with colorectal polyps.
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Zhu DW, Xu GJ, Rehse PH, Shi R, Zhao FK, Lin SX. Crystallization and preliminary crystallographic data of fructose-1,6-bisphosphatase from human muscle. ACTA CRYSTALLOGRAPHICA SECTION D: BIOLOGICAL CRYSTALLOGRAPHY 2001; 57:847-9. [PMID: 11375504 DOI: 10.1107/s0907444901004371] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/29/2000] [Accepted: 03/12/2001] [Indexed: 11/10/2022]
Abstract
The enzyme human muscle fructose-1,6-bisphosphatase, which plays a critical role in gluconeogenesis, has been crystallized in the presence of 2-propanol, polyethylene glycol and magnesium chloride at pH 7.5. The space group was determined to be P4(2)2(1)2, with unit-cell parameters a = b = 73.57, c = 146.50 A, alpha = beta = lambda = 90 degrees and one subunit in the asymmetric unit. A 99.6% complete data set to 2.04 A has been collected at the National Synchrotron Light Source.
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Rando RJ, Shi R, Hughes JM, Weill H, McDonald AD, McDonald JC. Cohort mortality study of North American industrial sand workers. III. Estimation of past and present exposures to respirable crystalline silica. THE ANNALS OF OCCUPATIONAL HYGIENE 2001; 45:209-16. [PMID: 11295144] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/19/2023]
Abstract
BACKGROUND Lung cancer and silicosis mortality were examined longitudinally and by a case-referent analysis in a cohort of workers selected from the North American industrial sand industry. Date of hire in the case-referent sub-cohort extended as far back as the second decade of the twentieth century. OBJECTIVE The aim of this study component was to develop estimates of average and cumulative exposure to respirable crystalline silica for the 342 selected cases and referents. METHODS Process and dust control histories were developed for each plant, and quantitative exposure data obtained from each of them and from a trade organization. An algorithm was developed to convert historical exposures reported in particle count concentrations to modern measures of mass concentration of respirable crystalline silica. Personal exposures were adjusted for use of protective equipment based on frequency of use and type of protection. FINDINGS Between 1974 and 1998, a total of 14249 exposure measurements had been taken using a cyclone and membrane filter and gave an overall geometric mean of 42 microg/m3. The only exposure data identified earlier were based on approximately 500 samples collected across the industry between 1947 and 1955 using the Greenburg-Smith impinger, with analysis by microscopy. These data were converted to modern measures using a factor of 1 mppcf = 276 microg/m3 respirable dust and then adjusting for percentage silica. In general, the highest exposures occurred in bagging and bulk-loading operations and the lowest in wet processing of sand. CONCLUSIONS There has been a substantial decline in exposure levels in this industry over time. The decline was rapid between the 1940s and 1970s and current exposures are, on average, less than 50 microg/m3. The use of personal protective equipment was judged to have had little impact on exposure before the 1970s.
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Hughes JM, Weill H, Rando RJ, Shi R, McDonald AD, McDonald JC. Cohort mortality study of North American industrial sand workers. II. Case-referent analysis of lung cancer and silicosis deaths. THE ANNALS OF OCCUPATIONAL HYGIENE 2001; 45:201-7. [PMID: 11295143] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/19/2023]
Abstract
BACKGROUND A cohort mortality study of 2670 men in nine North American industrial sand plants resulted in 83 deaths from lung cancer 20 or more years after hire (standardized mortality ratio 139) and 37 deaths from silicosis (including seven from silico-tuberculosis). The lung cancer excess was unrelated to duration of employment and not found in all plants. OBJECTIVES The primary aim was to determine whether lung cancer risk among these employees was related to quantitative estimates of crystalline silica exposure, after allowance for cigarette smoking. A secondary aim was to do the same for silicosis mortality, partly as a means of validating the estimated levels of exposure. METHODS A nested case-referent study was undertaken with cases matched with up to two controls on plant, age and date of first employment from men who survived the case. Exposures were estimated by linking work histories to a job-exposure matrix, undertaken separately. Cigarette smoking information was obtained from medical records and other sources, blind as to case-control status. Matched statistical analyses were conducted using conditional logistic regression. FINDINGS Odds ratios for silicosis mortality were significantly related to cumulative silica exposures and tended to a relationship with category of average crystalline silica concentration, but inconsistently with length of employment. After accounting for a strong effect of cigarette smoking, odds ratios for lung cancer were related to cumulative crystalline silica exposure and to average silica concentration, but not to length of employment. CONCLUSION These findings support a causal relationship between lung cancer and quartz exposure after allowance for cigarette smoking, in the absence of cristobalite or other known occupational carcinogens.
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Yu H, Nicar MR, Shi R, Berkel HJ, Nam R, Trachtenberg J, Diamandis EP. Levels of insulin-like growth factor I (IGF-I) and IGF binding proteins 2 and 3 in serial postoperative serum samples and risk of prostate cancer recurrence. Urology 2001; 57:471-5. [PMID: 11248622 DOI: 10.1016/s0090-4295(00)01003-7] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
OBJECTIVES To determine changes of insulin-like growth factor I (IGF-I), IGF binding protein-2 (IGFBP-2), and IGFBP-3 levels in serial postoperative serum samples from prostate cancer patients with and without relapse and to evaluate the prognostic value of these molecules in the recurrence of prostate cancer. METHODS From a group of patients with prostate cancer who had been followed for disease recurrence for almost 5 years after radical prostatectomy, we selected 38 patients (cases) who developed recurrent disease and 40 patients (controls) who were in remission. Of these patients, 70 had 4 and 8 had 3 serial postoperative serum samples collected. The median times for serum collection after surgery were 1.5 years for the first serial samples, 2.6 years for the second, 3.5 years for the third, and 4.5 years for the fourth. Serum levels of IGFBP-2, IGFBP-3, and IGF-I were measured, using commercial immunoassay kits. RESULTS The study showed lower serum levels of IGFBP-2 and IGFBP-3 in the cases than in controls(P <0.05) but no difference in IGF-I levels between the two groups (P = 0.277). In the sequential samples, IGFBP-2 levels increased over time in the controls (P = 0.014) but did not change in the cases (P = 0.528). There were no increasing or decreasing trends for IGF-I and IGFBP-3 in either case or control group(P >0.05). CONCLUSIONS The study suggests that IGFBP-2 may play a role in the progression of prostate cancer, but serum levels of IGFBP-2 as well as IGF-I and IGFBP-3 have no predictive values in the prognosis of prostate cancer.
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Abstract
Previous work has shown that newborn infants categorically discriminate the fundamental syntactic category distinction between lexical and grammatical words. In this article, we show that by the age of 6 months, infants prefer to listen to lexical over grammatical words. In Experiment 1, infants were habituated to a list of either lexical or grammatical words, and then tested on new lists of words from the same and the contrasting categories. The infants showed recovery to lexical words after habituation to grammatical words but not vice versa. This asymmetry indicates a possible preference for lexical words. In Experiments 2 and 3, preference was assessed directly by presenting infants with alternating trials of lexical and grammatical words, in the central-fixation preference procedure. The infants looked significantly longer during lexical-word than grammatical-word trials. These results show that by 6 months, infants attend preferentially to lexical words. The implications of this emerging attentional preference for subsequent language acquisition are discussed.
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Guo Y, Cai X, Zhao X, Shi R. [Effect of five kinds of vegetable seed oil on serum lipid and lipid peroxidation in rats]. WEI SHENG YAN JIU = JOURNAL OF HYGIENE RESEARCH 2001; 30:50-1. [PMID: 11255765] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/19/2023]
Abstract
The effects of vegetable seed oil on hyperlipidemia induced by high lipid diet in rats. Male adult Wistar rats were fed on the test diet containing 94% high lipid diet and 6% lard pinon seed oil, perilla seed oil, blackcurrent seed oil, borage seed oil and evening primrose seed oil respectively for 3 weeks. The results showed that the vale of trilyceride(TG), total cholesterol(TC), low density lipoprotein cholesterol (LDL-C), LDL-C/HDL-C(high density lipoprotein cholesterol) ratio increased and the vale of HDL-C/TC ratio and lecithin-cholesterol acyltransferase(LCAT) activity decreased in the groups with vegetable seed oil were less than that of the control group. The results suggested that all the five kinds of vegetable seed oil had the effect of regulating lipid metabolism of hyperlipidemia rats to some extent. Pinon seed oil and borage seed oil may be well suited for the prevention of atherosclerosis.
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Shi R, Asano T, Vining NC, Blight AR. Control of membrane sealing in injured mammalian spinal cord axons. J Neurophysiol 2000; 84:1763-9. [PMID: 11024068 DOI: 10.1152/jn.2000.84.4.1763] [Citation(s) in RCA: 62] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The process of sealing of damaged axons was examined in isolated strips of white matter from guinea pig spinal cord by recording the "compound membrane potential," using a sucrose-gap technique, and by examining uptake of horseradish peroxidase (HRP). Following axonal transection, exponential recovery of membrane potential occurred with a time constant of 20 +/- 5 min, at 37 degrees C, and extracellular calcium activity ([Ca(2+)](o)) of 2 mM. Most axons excluded HRP by 30 min following transection. The rate of sealing was reduced by lowering calcium and was effectively blocked at [Ca(2+)](o) </= 0.5 mM, under which condition most axons continued to take up HRP for more than 1 h. Sealing at higher [Ca(2+)](o) was blocked by calpain inhibitors (calpeptin and calpain inhibitor-1) indicating a requirement for type II (mM) calpain in the sealing process. Following compression injury, the amplitude of the maximal compound action potential conducted through the injury site was reduced. The extent of amplitude reduction was increased when the tract was superfused with calcium-free Krebs' solution (Ca(2+) replaced by Mg(2+)). These results suggest that the fall in [Ca(2+)](o) seen following injury in vivo is sufficient to prevent membrane sealing and may paradoxically contribute to axonal dieback, retrograde cell death, and "secondary" axonal disruption.
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Shi R, Pryor JD. Temperature dependence of membrane sealing following transection in mammalian spinal cord axons. Neuroscience 2000; 98:157-66. [PMID: 10858622 DOI: 10.1016/s0306-4522(00)00096-8] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Using an in vitro sucrose-gap recording chamber, sealing of cut axons in isolated strips of white matter from guinea pig spinal cord was measured by recording the "compound membrane potential". This functional sealing was found to correlate well with anatomical resealing, measured by a horseradish peroxidase uptake assay. Near-complete functional and anatomical recovery of the axonal membrane occurred routinely within 60 min following transection at 37 degrees C in regular Krebs' solution. The rate of membrane potential recovery is exponential, with a time-constant of 20+/-5 min. The sealing process at 31 degrees C was similar to that at 37 degrees C, and was effectively blocked at 25 degrees C, under which condition most axons continued to take up horseradish peroxidase for more than 1h, and failed to substantially recover their membrane potential. Seventy-five percent of the cords transected at 40 degrees C had similar sealing behavior to those at 37 degrees C and 31 degrees C. The balance failed to seal the cut end. Two-dimensional morphometric analysis has shown that raising the temperature from 25 degrees C to above 31 degrees C significantly decreases axonal permeabilization to horseradish peroxidase (increases the sealing of transected ends) across all areas of a transverse section of spinal cord. Moreover, this enhancement of sealing exists across all axon calibers. Since severe cooling compromises membrane resealing, caution needs to be taken when hypothermic treatment (below 25 degrees C) is applied within the first 60 min following mechanical injury. In summary, we have found that at normal temperature (37 degrees C), nerve fibers repair their damaged membrane following physical injury with an hour. This is similar at mildly lower (31 degrees C) and relatively higher (40 degrees C) temperature, although some fibers tend to collapse under this febrile temperature. Moreover, severely low temperature (25 degrees C) hindered the repair of damaged membranes. Based on our study, caution is needed in treating spinal cord injury with low temperatures.
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Tian Y, Liu X, Shi R, Liu Y, Wu Q, Zhang X. Radionuclide techniques for evaluating dilated cardiomyopathy and ischemic cardiomyopathy. Chin Med J (Engl) 2000; 113:392-5. [PMID: 11776090] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/23/2023] Open
Abstract
OBJECTIVE To assess the clinical significance of radionuclide techniques in evaluating dilated cardiomyopathy (DCM) and ischemic cardiomyopathy (CAD-CM). METHODS 28 patients with DCM and 55 patients with CAD-CM were studied. All patients underwent 99mTc-MIBI myocardial perfusion SPECT and 18F-FDG myocardial metabolic PET. 78 patients had 99mTc-RBC radionuclide ventriculography and 68 patients had coronary angiography. RESULTS The results of 23 patients (82%) with DCM showed mild and non-segmental distribution perfusion abnormalities. 52 patients with CAD-CM (95%) showed perfusion abnormalities that distributed along the coronary vessel territories. Significant perfusion defects were found in 4 patients with DCM (14%) and 45 patients with CAD-CM (82%) (P < 0.01). The average perfusion score was 4.5 +/- 2.6 in DCM and 9.6 +/- 2.5 in CAD-CM and the area of diminished perfusion was significantly smaller in DCM than in CAD-CM (P < 0.001). Two patients with DCM and 18 patients with CAD-CM had metabolic defects. The patterns of perfusion/metabolic imaging showed mismatch in most patients with CAD-CM but match in most patients with DCM. The LVEF in patients with DCM and CAD-CM was both decreased but the decreases were not statistically different between DCM and CAD-CM. The RVEF in patients with DCM was significantly lower than that in patients with CAD-CM (32.4% +/- 13.9% vs 40.9% +/- 15.4%, P < 0.05). CONCLUSION The radionuclide techniques are helpful for distinguishing DCM from CAD-CM. The segmental perfusion abnormality and RVEF are the most important factors for differentiation of DCM from CAD-CM.
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Song C, Wang P, Sun H, Shi H, Yang Q, Cui X, Shi R. [The in vivo degradation, adsorption and excretion of poly(epsilon-caprolactone)]. SHENG WU YI XUE GONG CHENG XUE ZA ZHI = JOURNAL OF BIOMEDICAL ENGINEERING = SHENGWU YIXUE GONGCHENGXUE ZAZHI 2000; 17:25-8. [PMID: 10879186] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/16/2023]
Abstract
The in vivo degradation of poly(epsilon-caprolactone(PCL) was studied in rats. The results showed that the PCL capsules with an initial molecualr weight of 66,000 stayed intact in vivo for 2 years, although the molecular weight of the capsules gradually declined during the two-year implantation. It then degraded into low molecular wight pieces with the extension of the implantation. Tritium-labeled low molecular weight PCL was subcutaneously implanted in rats to further investigate the absorption and excretion of the material. The radioactivity was first detected in blood 15 days post the implantation. At the same time radioactive excreta were recovered from feces and urine. An accumulative 92% of the implanted radioactive dosage was excreted from feces and urine 135 days post the implantation. In the meanwhile, the blood radioactivity dropped to the background level. Radioactivity in the organs was all close to the background level indicating that the material did not cumulate in body tissue and could be completely excreted.
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Shi R, Liu X, Fang W, Zhou B, Li S, Li F. The value of 99mTc-MIBI myocardial perfusion spect imaging in detecting coronary artery disease in patients with valvular disease before operation. CHINESE MEDICAL SCIENCES JOURNAL = CHUNG-KUO I HSUEH K'O HSUEH TSA CHIH 2000; 15:64-6. [PMID: 12899405] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 03/04/2023]
Abstract
OBJECTIVE The aim of this study was to detect coronary artery disease using 99mTc-MIBI myocardial perfusion imaging in patients with valvular disease. METHODS Thirty patients with valvular disease confirmed by echocardiography underwent 99mTc-MIBI myocardial perfusion imaging using multiSPECT 1h after stress test (exercise, dipyridamole or dobutamine test) and were performed coronary angiography within 1 month before valvular operation. RESULTS For 29 out of the 30 patients, the results of 99mTc-MIBI myocardial perfusion imaging were similar with those of coronary angiography, the concordance rate was 96.7% and the negative predictability was 100%. CONCLUSION 99Tc-MIBI myocardial perfusion imaging is a reliable non-invasive method for detecting coronary artery disease in patients with valvular disease and so as to draw up suitable operation programs for them.
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Borgens RB, Shi R. Immediate recovery from spinal cord injury through molecular repair of nerve membranes with polyethylene glycol. FASEB J 2000; 14:27-35. [PMID: 10627277 DOI: 10.1096/fasebj.14.1.27] [Citation(s) in RCA: 101] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
A brief application of the hydrophilic polymer polyethylene glycol (PEG) swiftly repairs nerve membrane damage associated with severe spinal cord injury in adult guinea pigs. A 2 min application of PEG to a standardized compression injury to the cord immediately reversed the loss of nerve impulse conduction through the injury in all treated animals while nerve impulse conduction remained absent in all sham-treated guinea pigs. Physiological recovery was associated with a significant recovery of a quantifiable spinal cord dependent behavior in only PEG-treated animals. The application of PEG could be delayed for approximately 8 h without adversely affecting physiological and behavioral recovery which continued to improve for up to 1 month after PEG treatment.
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Thakur ML, Pallela VR, Consigny PM, Rao PS, Vessileva-Belnikolovska D, Shi R. Imaging vascular thrombosis with 99mTc-labeled fibrin alpha-chain peptide. J Nucl Med 2000; 41:161-8. [PMID: 10647619] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/15/2023] Open
Abstract
UNLABELLED An agent that permits scintigraphic detection of chronic deep venous thrombosis (DVT) or pulmonary embolism (PE) would be a welcome addition to the armamentarium of nuclear medicine. Because fibrin is the integral part of each clot, old or fresh, we hypothesized that a 99mTc-labeled fibrin alpha-chain N-terminal peptide, Gly-Pro-Arg-Pro-Pro, that binds to the C-terminal portion of the gamma-chain of fibrin can detect DVT and PE. METHODS The peptide was modified to Gly-Pro-Arg-Pro-Pro-Aba-Gly-Gly-(D)-Ala-Gly to permit efficient binding of 99mTc (99mTc-TP 850). The stability of the peptide was examined in vitro as well as in vivo. The ability of the agent to bind to rabbit, dog, and human fibrin and to inhibit adenosine diphosphate-induced platelet aggregation was examined. Blood clearance and 3-h tissue distribution were studied. DVT was induced in 8 rabbits using a stimulating electrode and in 2 rabbits by inserting a thrombin-soaked suture. PE was induced in 6 additional rabbits by introducing tantalum-impregnated blood clots into the right atrium, and the rabbits were radiographed to locate the emboli. 99mTc-TP 850 was then injected through a lateral ear vein, and each rabbit was imaged for up to 3 h. The rabbits were then killed, the heart and lungs were dissected and radiographed and the clots were harvested so that clot-to-blood radioactivity ratios could be determined. RESULTS The peptide analog permitted efficient incorporation of 99mTc, which was stable in vitro and in vivo. The blood clearance was biphasic, with an alpha phase half-life of approximately 4 min (20%) and a beta phase half-life of approximately 13 min (88%). The mean binding of 99mTc-TP 850 to human, dog, and rabbit fibrin was 46% +/- 2%, 60% +/- 3%, and 56% +/- 2.5%, respectively, and the inhibitory concentration of 50% for dog and rabbit platelet aggregation was 236 pm and 167 pm, respectively. All clots, including 24-h-old pulmonary emboli, were delineated. The radioactivity associated with clots varied from 0.01 to 0.09 %ID/g, with clot-to-blood radioactivity ratios ranging from 1.2 to 12.0. However, 48-h-old pulmonary emboli had lysed and were seen neither by radiography nor by scintigraphy. CONCLUSION A fibrin alpha-chain, N-terminal peptide that binds to the C-terminal portion of the gamma-chain of fibrin has been modified and labeled with 99mTc. The resultant peptide is stable in vitro and in vivo; binds to human, dog, and rabbit fibrin in large quantities; and inhibits platelet aggregation. The peptide clears rapidly from the blood and delineates experimental DVT and PE in rabbits. This agent is worthy of further investigation.
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Shi R, Werker JF, Morgan JL. Newborn infants' sensitivity to perceptual cues to lexical and grammatical words. Cognition 1999; 72:B11-21. [PMID: 10553673 DOI: 10.1016/s0010-0277(99)00047-5] [Citation(s) in RCA: 213] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
In our study newborn infants were presented with lists of lexical and grammatical words prepared from natural maternal speech. The results show that newborns are able to categorically discriminate these sets of words based on a constellation of perceptual cues that distinguish them. This general ability to detect and categorically discriminate sets of words on the basis of multiple acoustic and phonological cues may provide a perceptual base that can help older infants bootstrap into the acquisition of grammatical categories and syntactic structure.
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145
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Shi R, Borgens RB, Blight AR. Functional reconnection of severed mammalian spinal cord axons with polyethylene glycol. J Neurotrauma 1999; 16:727-38. [PMID: 10511246 DOI: 10.1089/neu.1999.16.727] [Citation(s) in RCA: 72] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
We describe a technique using the water-soluble polymer polyethylene glycol (PEG) to reconnect the two segments of completely transected mammalian spinal axons within minutes. This was accomplished by fusing completely severed strips of isolated guinea pig thoracic white matter maintained in vitro in a double sucrose gap recording chamber. The faces of the severed segments were pressed together, and PEG (MW 1,400-3,500 d; approximately 50% by weight in distilled water) was applied directly to this region through a micropipette and removed by aspiration within 2 min. Successful fusion was documented by the immediate restored conduction of compound action potentials through the original transection and by the variable numbers of fused axons in which anatomical continuity was shown to be restored by high-resolution light microscopy and by the diffusion of intracellular fluorescent dyes through fused axons. These data support the conclusion that some severed and subsequently PEG-fused spinal axons both demonstrate restored anatomical continuity and also are physiologically competent to conduct action potentials. This work adds to our previous demonstration that PEG application can immediately repair severely crushed, rather than cut, spinal cord white matter, and may lead to novel treatments for acute trauma to the central and peripheral nervous systems.
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146
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Zhang X, Liu X, Shi R, Wu Q, Gao R, Liu Y, Hu S, Guo S, Xie F, Li Y. Evaluation of the clinical value of combination of 99mTc-MIBI myocardial SPECT and 18F-FDG PET in assessing myocardial viability. RADIATION MEDICINE 1999; 17:205-10. [PMID: 10440109] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/13/2023]
Abstract
PURPOSE To evaluate the value of 18F-FDG PET metabolic imaging and 99mTc-MIBI SPECT in the identification of myocardial viability in patients with previous myocardial infarction and left ventricular dysfunction. METHODS 18F-FDG PET (made in China) and 99mTc-MIBI SPECT were performed in 60 patients (pts) (age 54+/-9 yr) with myocardial infarction before revascularization. Before and after revascularization, LVEF and wall motion were measured with echocardiography in 36 pts (Group A), and myocardial perfusion was evaluated in 24 pts (Group B). RESULTS According to the interpretation of perfusion and metabolic images, myocardial segments were classified into mismatch (MM): reduced myocardial perfusion and normal FDG uptake or match (M): reduced perfusion and FDG uptake. Out of 264 segments with hypoperfusion, 145 (54.9%) were MM, suggesting viable myocardium (G-A1 and G-B1), 119 (45.1%) were M, suggesting necrosis (G-A2 and G-B2). After revascularization, LVEF was increased in G-A1 (49+/-15% vs. 59+/-7%, p<0.05), and in G-B1 (50+/-8% vs. 59+/-12%, p<0.05), but was not improved in G-A2 and G-B2. LVEDD was decreased in G-A1 and G-B1 (p<0.05) and was unchanged in G-A2 and G-B2. The positive predictive value (PPV) of FDG PET for improvement of regional wall motion after revascularization was 88%, and the negative predictive value (NPV) was 72.6%. The PPV for improvement of perfusion was 84.1%, NPV was 85%, and accuracy was 84.4%. CONCLUSION 18F-FDG imaging with Chinese PET has clinical value for assessing myocardial viability and identifying patients who will benefit from revascularization.
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Abstract
Acute repair of crushed guinea pig spinal cord by polyethylene glycol. We have studied the responses of adult guinea pig spinal cord white matter to a standardized compression within a sucrose gap recording chamber. This injury eliminated compound action potential (CAP) conduction through the lesion, followed by little or no recovery of conduction by 1 h postinjury. We tested the ability of polyethylene glycol (PEG) to repair the injured axons and restore physiological function. Local application of PEG (1,800 MW, 50% by weight in water) for approximately 2 min restored CAP conduction through the injury as early as 1 min post PEG application. The recovery of the CAP </=1 h was significantly greater in treated compared with control spinal cords (controls = 3.6% of the preinjury amplitude; PEG treated = 19%; P < 0.0001, unpaired Student's t-test). Stimulus-response analysis indicated that the susceptibility for recovery was similar for all calibers of axons after PEG application. The enhanced recovery of conduction after PEG treatment was associated with an early alteration in conduction properties relative to control spinal cords. This included increased refractoriness and sensitivity to potassium channel blockade using 4-aminopyridine (4-AP). Normally 4-AP enhanced the amplitude of the recovering CAPs by approximately 40% in control spinal cords; however this effect was nearly doubled to approximately 72% in PEG treated spinal cords. Because severe clinical injuries to the spinal cord (and some peripheral nerves) are both resistant to medical treatment and usually produced by compression, we discuss the possible clinical benefits of PEG application.
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148
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Guo Y, Wang Q, Shi R, Zhou X. [Research of experimental fistula stimuli vestibule evoked response]. LIN CHUANG ER BI YAN HOU KE ZA ZHI = JOURNAL OF CLINICAL OTORHINOLARYNGOLOGY 1999; 13:170-2. [PMID: 12563996] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/28/2023]
Abstract
OBJECTIVE To investiqate a way of stimulation for experimental vestibul evoked response. The artificial fistula of right upper semicircular canal was made in 12 guineapig. METHOD Using a fistula stimuli probe device designed specially. RESULT We obtain a potential consisting of 3-4 positive waveforms. We called it the fistula stimuli vestibule evoked response (FsVeR). They had a coincide character. The response disappeared when the animal died. The cervical spinal section, orbital removal and facial nerve removal had little effects to FsVeR. When severe inner ear damage produced by Gentamycin injection, the potential disappeared. The potential disappeared but ABR were existed. When the upper semicircular canal and its nerve damage. The noise screen had a little affection to FsVeR. CONCLUSION These results indicated that FsVeR was mainly originated from the vestivbule system. The development of this recording technique provides a new method and maybe has important value for vestibule experimental research work.
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Pallela VR, Thakur ML, Consigny PM, Rao PS, Vasileva-Belnikolavska D, Shi R. Imaging thromboembolism with Tc-99m-labeled thrombospondin receptor analogs TP-1201 and TP-1300. Thromb Res 1999; 93:191-202. [PMID: 10064274 DOI: 10.1016/s0049-3848(98)00180-7] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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150
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Shi R, Ji G, Zhao L, Wang S. Effects of electroacupuncture and twirling reinforcing-reducing manipulations on volume of microcirculatory blood flow in cerebral pia mater. J TRADIT CHIN MED 1998; 18:220-4. [PMID: 10453620] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/13/2023]
Abstract
Effects of electroacupuncture (EA) and routine acupuncture with twirling reinforcing and reducing manipulation of the needle (RA) both at Zusanli point (St 36) on volume of microcirculatory blood flow in the cerebral pia mater were observed by fenestration of the cranial bone and laser Doppler microcirculatory blood flow analyser. Results showed that both RA and EA could increase the volume of microcirculatory blood flow in the cerebral pia mater; and that the increase in the EA group was superior to that in RA group. This suggests that a moderate and effective stimulation is a key to the production of a regulative effect on the organism.
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