微囊化兔嗅球组织移植对脊髓损伤大鼠细胞凋亡的影响

目的:观察微囊化兔嗅球组织细胞移植对大鼠脊髓全横断损伤后细胞凋亡及功能恢复的影响,并探讨其对脊髓继发性损伤的保护作用及其机制。方法:实验于2004-10/2005-07在南昌大学基础医学院应用解剖研究室完成。选择清洁级SD大白鼠120只,按随机数字表法分为4组:正常对照组、损伤对照组、单纯细胞悬液移植组、微囊化移植组,每组30只。制作T10节段脊髓全横断损伤模型。正常对照组仅打开椎管,暴露脊髓不作移植;损伤对照组仅用明胶海绵填塞脊髓损伤腔隙;单纯细胞悬液移植组植入吸附细胞悬液的明胶海绵块;微囊化移植组用与断端腔隙大小相吻合的明胶海绵块吸附10μL的微囊化细胞,植入洞腔。分别于术后12h,1,3,7,21d5个时间点对动物进行BBB评分后处死。取损伤区1cm范围脊髓节段,常规石蜡包埋,水平切片进行苏木精-伊红染色、TUNEL染色,观察凋亡细胞的数量及分布变化。按BBB评分法对大鼠术后运动功能的恢复情况进行评分,共分22级,最低分0分,最高分21分,分数越高,运动功能恢复越完善。结果:纳入大鼠120只,存活96只,存活率为80%。其中以损伤对照组及单纯细胞悬液移植组死亡率较高,损伤对照组大鼠死亡的主要原因可能是脊髓损伤导致损伤平面以下神经功能的丧失所引起的一系列并发症所导致的;而单纯细胞悬液移植组是因为免疫排斥反应所导致。①术后3d内各组间BBB评分差异无显著性意义(P>0.05);术后7,21d微囊化移植组和单纯细胞悬液移植组大鼠BBB评分高于损伤对照组,差异均有显著性意义[分别为(7.25±1.17),(4.58±0.38),(2.67±0.61)分;(10.42±1.63),(6.08±0.80),(3.33±0.68)分,F=4.528,3.821,P<0.05],且经微囊化处理后比单纯兔嗅球组织细胞悬液移植运动功能恢复更好(F=4.112,P<0.05);而损伤对照组大鼠后肢运动功能恢复均较差。②光镜下损伤对照组、单纯细胞悬液移植组脊髓损伤后,脊髓内空洞增大,损伤范围基本确定,周围有炎性细胞浸润;在微囊化移植组脊髓损伤明显减轻,细胞皱缩不明显、胞质、胞核较清晰。③术后1,3,7d微囊化移植组TUNEL阳性细胞数及凋亡指数低于损伤对照组,差异有显著性意义(以术后3d为例,TUNEL阳性细胞数分别为(8.83±1.33),(14.50±1.05)个/视野,P<0.01;凋亡指数分别为10.45±1.58,17.06±1.23,P<0.01)。结论:微囊化兔嗅球组织细胞移植对大鼠脊髓全横断损伤后细胞凋亡具有保护作用,能促进脊髓功能的恢复。     

Regional distribution of muscarinic receptors preferring gallamine in the rat brain

The regional distribution of muscarinic receptors recognized by the antagonist gallamine was determined autoradiographically by the ability of gallamine to reduce the binding of [3H]quinuclidinyl benzilate in rat brain slices. The inhibition data obtained from indirect binding assays on whole slices indicated that gallamine distinguished at least two sites with differing affinities. Analysis using a two-site model gave Kh = 0.6 microM, K1 = 10 microM. The regions of highest and lowest affinity for gallamine were apparent qualitatively by visual inspection of the autoradiograms. A number of regions in coronal sections at three different levels were compared by microdensitometry. Gallamine possessed greater overall affinity for the diencephalon and brainstem than for the forebrain. Within the forebrain, the septal nucleus was unique in that it displayed high affinity for gallamine. Within the brainstem, the superior colliculus had the greatest proportion of sites with high affinity for gallamine. In general, the binding profile of gallamine was opposite to that of the antagonist pirenzepine and similar to that of the agonist carbachol, suggesting that gallamine is selective for M2 muscarinic receptors.     

Evidence-based assessment: evaluation of the formocresol versus ferric sulfate primary molar pulpotomy

PURPOSE: Formocresol and ferric sulfate were evaluated as pulpotomy medicaments using evidence-based dentistry principles. Formocresol has been challenged as a potential carcinogen and mutagen, leading to consideration of ferric sulfate. METHODS: The PICOT statement was: (P) In human carious primary molars with reversible coronal pulpitis, (I) does a pulpotomy performed with ferric sulfate, (C) compared with formocresol, (O) result in dinical/radiographic success, (T) in time periods up to exfoliation? Relevant papers (N=894) were identified from databases and inclusion criteria were applied; 94 papers remained (randomized clinical trials [RCTs]=7; clinical trials [CTs]=28; case-control studies=14; opinions, cohort, and cross-sectional studies=4; reviews=22; irretrievable papers=19). Three RCTs and 10 CTs (total teeth: formocresol=753; ferric sulfate=90) were meta-analyzed; 1 RCT and 1 CT were tested for homogeneity (odds ratios; 95% confidence intervals); 3 RCTs and 10 CTs were examined by student's t test. RESULTS: Clinical data indicated ferric sulfate was significantly more successful than formocresol (OR=1.95; CI=1.01-3.80). Radiographic data indicated no difference between medicaments (OR=0.90; CI=0.58-1.39). Medicaments did not differ with t-tests of clinical (P>.10) and radiographic (P>.50) data. CONCLUSIONS: This evidence-based assessment concluded that, in human carious primary molars with reversible coronal pulpitis, pulpotomies performed with either formocresol or ferric sulfate are likely to have similar clinical/radiographic success.     

Myocardial imaging with 134mCesium. Comparison of scintigraphic and cineradiographic results.

Thirty-four patients had noninvasive myocardial perfusion imaging at rest using 134mCs. The results were compared with the results of coronary cineangiography and left ventriculography. All 21 patients who had abnormal left ventriculograms had corresponding myocardial imaging defects. This group included 14 patients with electrocardiographic evidence of either an old inferior, anteroseptal, anterior, or anterolateral myocardial infarction. Thirteen patients had normal left ventriculograms: this group included 6 patients with 75% or greater obstruction of one or more coronary arteries and 7 patients with normal or insignificantly diseased vessels. Only 2 of these patients had abnormal myocardial images: both had severe obstruction of the proximal left anterior descending artery without collateral filling of this vessel. In the resting patient who has 134mCs myocardial imaging, we concluded that we primarily are visualizing varying degrees of scarred myocardium rather than reversibly ischemic myocardium.     

Cytomegalovirus infection after bone marrow transplantation: an association with acute graft-v-host disease

Among 181 patients undergoing allogeneic bone marrow transplantation over a five-year period (1978 through 1982), cytomegalovirus (CMV) infection was a frequent and often lethal complication. Recipient pretransplant serology was the most important predictor of posttransplant CMV infection. CMV infection occurred in 26/137 seronegative recipients and in 28/44 seropositive recipients (P less than .001). Among patients who developed CMV infection, the time to infection was identical in seronegative and seropositive patients (median, 71 days post transplant). Bone marrow donor CMV serology did not significantly influence CMV infection rate. CMV infection was strongly associated with acute graft-v-host disease (AGVHD), occurring in 34/81 patients with AGVHD and 20/100 without GVHD (P less than .001). AGVHD preceded CMV infection by 33.7 days (mean) in patients developing both complications. Patients who developed CMV infections had also received more cellular blood products post transplant. These data suggest that CMV infection may occur through reactivation of latent virus (in seropositive recipients) or through exogenous exposure, possibly through transfused blood products, but that duration of immunoincompetence may be more critical than route of exposure in timing of clinically evident CMV infection. Prophylaxis tailored to the likely infectious source and more effective GVHD prevention both may be critical in preventing CMV infection after bone marrow transplantation.     

Use of oligonucleotide hybridization in the characterization of a beta zero-thalassemia gene (beta 37 TGG----TGA) in a Saudi Arabian family [published erratum appears in Blood 1986 Jul;68(1):323]

Analysis of restriction site polymorphisms in the beta-globin gene cluster of a Saudi Arabian female with beta zero-thalassemia demonstrated that both of her beta-globin genes were missing a nonpolymorphic AvaII site in exon 2. Examination of the normal nucleotide sequence surrounding this AvaII site revealed that either of two nucleotide substitutions, TGG----TAG or TGG----TGA, could produce a nonsense codon at codon 37 and eliminate the AvaII site. Consequently, two oligonucleotides (19-mers spanning codons 36 through 41 and containing either TAG or TGA at codon 37) were synthesized and hybridized against genomic DNA of the proband and her family. Specific hybridization with one of the oligomers demonstrated that the patient's beta o-thalassemia was the result of homozygosity for the TGG----TGA mutation at codon 37. In certain cases, oligonucleotide hybridization using genomic DNA may obviate the need for gene cloning and sequencing in the characterization of point mutations.     

The percentage of dense red cells does not predict incidence of sickle cell painful crisis

To test the hypothesis that the tendency of hemoglobin S (HbS) to polymerize within cells is the major determinant of the incidence of vaso-occlusive episodes, we have examined the effect of the percentage of dense cells (as measured by Percoll-Stractan continuous density gradient centrifugation) on the frequency of painful crises in a group of 36 patients with sickle cell disease. No correlation was found between the percentage of dense cells and admissions for crisis. Among the patients with known alpha-gene status (n = 25), the strong correlation between decreased dense cells and alpha-thalassemia (- alpha/alpha alpha) reported previously was confirmed (P less than .001). In addition, in this small subset, patients with alpha- thalassemia (-alpha/alpha alpha) appeared to have a marginally increased number of admissions for sickle cell crisis (t = 2.1910, P less than .05), which was independent of the percentage of dense cells. We conclude that the percentage of dense sickle cells cannot predict the incidence of painful crisis, suggesting that other factors (microcirculatory regulation or other humoral and cellular factors) are more important in the generation maintenance of painful crises than the necessary, but not sufficient, tendency of HbS-containing red cells to sickle.     

U.S. military mental health care utilization and attrition prior to the wars in Iraq and Afghanistan

Objective  

Health care utilization studies of mental disorders focus largely on the ICD-9 category 290–319, and do not generally include analysis of visits for mental health problems identified under V-code categories. Although active duty service members represent a large young adult employed population who use mental health services at similar rates as age-matched civilian populations, V-codes are used in a larger proportion of mental health visits in military mental health care settings than in civilian settings. However, the utilization of these diagnoses has not been systematically studied. The purpose of this study is to characterize outpatient behavioral health visits in military health care facilities prior to Operation Iraqi Freedom, including the use of diagnoses outside of the ICD-9 290–319 range, in order to evaluate the overall burden of mental health care. This study establishes baseline rates of mental health care utilization in military mental health clinics in 2000 and serves as a comparison for future studies of the mental health care burden of the current war.     

Lactoferrin: a promoter of polymorphonuclear leukocyte adhesiveness

Polymorphonuclear leukocytes (PMN) degranulate, adhere to vascular endothelium, or aggregate to each other following exposure of the cells to high concentrations of chemotactic stimuli such as formyl-methionyl- leucyl phenylalanine (FMLP). PMN released the specific granule product lactoferrin more readily in response to chemotactic stimuli, which correlated with promotion of PMN aggregation as measured by light transmission and enhanced PMN adherence. Both concanavalin A (Con-A) and phorbol myristate acetate (PMA), agents that lead to specific granule discharge, induced and sustained human PMN aggregation. Similarly, supernatants, generated from Con-A-treated PMN, aggregated fresh PMN in the presence of alpha-methylmannoside, a competitive inhibitor of the lectin. Anti-human lactoferrin IgG but not normal goat IgG blunted the aggregation elicited by both PMA and FMLP. Both human milk lactoferrin and rabbit PMN lactoferrin aggregated human lactoferrin promoted PMN adherence to endothelial cells. The enhanced PMN stickiness was correlated with the early phase of degranulation. Thus, PMN lactoferrin serves an autoregulatory role to retain PMN at inflammatory sites to amplify the inflammatory response.     

Bloodstream infections due to Candida species: SENTRY antimicrobial surveillance program in North America and Latin America, 1997-1998

An international program of surveillance of bloodstream infections (BSI) in the United States, Canada, and Latin America detected 306 episodes of candidemia in 34 medical centers (22 in the United States, 6 in Canada, and 6 in Latin America) in 1997 and 328 episodes in 34 medical centers (22 in the United States, 5 in Canada, and 7 in Latin America) in 1998. Of the 634 BSI, 54.3% were due to Candida albicans, 16.4% were due to C. glabrata, 14.9% were due to C. parapsilosis, 8.2% were due to C. tropicalis, 1.6% were due to C. krusei, and 4.6% were due to other Candida spp. The percentage of BSI due to C. albicans decreased very slightly in the United States between 1997 and 1998 (56.2 to 54.4%; P = 0.68) and increased in both Canada (52.6 to 70.1%; P = 0.05) and Latin America (40.5 to 44. 6%; P = 0.67). C. glabrata was the second most common species observed overall, and the percentage of BSI due to C. glabrata increased in all three geographic areas between 1997 and 1998. C. parapsilosis was the third most prevalent BSI isolate in both Canada and Latin America, accounting for 7.0 and 18.5% of BSI, respectively. Resistance to fluconazole (MIC, >/=64 microgram/ml) and itraconazole (MIC, >/=1.0 microgram/ml) was observed infrequently in both 1997 (2.3 and 8.5%, respectively) and 1998 (1.5 and 7.6%, respectively). Among the different species of Candida, resistance to fluconazole and itraconazole was observed in C. glabrata and C. krusei, whereas isolates of C. albicans, C. parapsilosis, and C. tropicalis were all highly susceptible to both fluconazole (98.9 to 100% susceptible) and itraconazole (96.4 to 100% susceptible). Isolates from Canada and Latin America were generally more susceptible to both triazoles than U.S. isolates were. Continued surveillance appears necessary to detect these important changes.