图形翻转视觉诱发电位在视神经管减压后视神经损伤不同时期的变化特征

目的:观察视神经损伤动物模型在损伤后和不同时期视神经管减压后视觉诱发电位的变化,了解创伤性视神经损伤的手术时机与疗效的关系。方法:实验于2005-03/05在解放军南京军区南京总医院动物实验中心完成。①实验分组:30只新西兰白兔随机分为正常对照组、术后2d减压组、术后7d减压组、术后14d减压组、术后不减压组,每组6只。②造模:除正常对照组外,其余各组在视神经孔中塞入一细端为2mm直径的圆锥软硅胶,阻塞视神经孔,造成视神经的挤压伤。③指标检测:采用图形翻转视觉诱发电位检测损伤前、损伤后1h、减压前1h、减压后2周视功能变化,记录NPN曲线主波(P波)的绝对潜伏期、绝对波幅。正常对照组仅采集一组数据作为对照。结果:30只实验动物均进入结果分析。①正常对照组家兔图形翻转视觉诱发电位检查均引出典型NPN波型曲线,视神经挤压伤后1hNPN波形低阔扁平,P波潜伏期延长,波幅降低。②P波潜伏期:术后2d减压组减压后短于减压前[(71.25±8.51),(86.47±14.28)ms,P<0.05];术后7d减压组减压前后比较差异无显著性(P>0.05);术后14d减压组减压后明显长于减压前[(158.73±15.16),(116.35±17.13)ms,P<0.05]。术后2d减压组和术后7d减压组短于术后不减压组(P<0.01)。术后7,14d减压组和术后不减压组明显长于正常对照组(P<0.01)。③P波波幅:术后2d减压组减压后高于减压前[(5.25±0.78),(4.42±0.42)μV,P<0.05]。术后2d减压组减压后低于术后7d减压组、术后14d减压组(P<0.01),术后14d减压组低于术后7d减压组(P<0.05);术后7d减压组、术后14d减压组、术后不减压组低于正常对照组(P<0.01)。结论:神经元继发性损伤是视功能进行性下降的重要原因,视神经减压术有利于减轻视神经间接损伤,较早期(损伤后48h以内)减压可阻止轴突继发性损伤,避免视功能进一步下降,并在一定程度上逆转视功能的损害。     

Correlation of P-glycoprotein expression and function in childhood acute leukemia: a children's cancer group study

Clinical drug resistance may be attributed to the simultaneous selection and expression of genes modulating the uptake and metabolism of chemotherapeutic agents. P-glycoprotein (P-gp) functions as a membrane-associated drug efflux pump whose increased expression results in resistance to anthracyclines, epipodophyllotoxins, vinca alkaloids, and some alkylating agents. This type of resistance occurs as both de novo and acquired resistance to therapy for leukemia. We have studied P- gp expression and function in childhood acute leukemias by developing a series of doxorubicin- and vincristine-selected CEM, T-cell lymphoblastoid cell lines that recapitulate the low levels of expression and resistance seen clinically. These cell lines have been used to develop flow cytometric assays for the semiquantitative measurements of P-gp expression with the MRK16 monoclonal antibody and P-gp function using the enhanced retention of rhodamine 123 in the presence of verapamil, a resistance modulator. Kolmogorov-Smirnov statistics, represented by the D measurement, are used to determine the difference in level of P-gp expression by comparing MRK16 staining to an IgG2a isotype control. When D is > 0.09, there is an excellent correlation (R = 0.82) between P-gp expression and function. The evaluation of 107 bone marrow specimens from 84 children with lymphoblastic or myelogenous leukemia showed a statistically significant (P = .004) increase in P-gp function at relapse. P-gp expression at relapse, however, approached but did not reach a significant level (P = .097). Using this methodology, we can identify patients with levels of P-gp expression and function that we can define clinically, as well as children with discordant multidrug resistance phenotypes. This study supports the role of P-gp-mediated drug resistance in childhood leukemia and confirms that P-gp expression and function are measurable in their leukemic blasts. These assays provide the means for the in vitro testing of resistance modulators and the monitoring of in vivo response to treatment with these agents.     

Marrow harvesting from normal donors

The experience at a single institution in harvesting marrow for allogeneic transplantation on 1,270 occasions from 1,160 normal donors is presented in detail, together with an analysis of all the donor complications. Four donors were less than 2 years old, and the youngest was 6 1/2 months. No special difficulties were encountered with these young donors. Hospitalization time was three days or less for 99% of the procedures. Six donors had life-threatening complications; three of a cardiopulmonary and two of an infectious nature, and one cerebrovascular embolic episode. Significant operative site morbidity, usually transient neuropathies, occurred in ten procedures. Ten percent of the donations were associated with transient postoperative fever of unknown origin. Increasing donor age was associated with a reduction of the cellularity of the marrow harvest. The use of stored autologous blood permitted the avoidance of blood bank transfusion in 81% of males, 69% of females, and 50% of children. It was concluded that the procedure was associated with a very low risk of complication, but that the involvement of normal donors in such an operation justifies stringent monitoring.     

Allogeneic marrow transplantation for refractory anemia: a comparison of two preparative regimens and analysis of prognostic factors

From 1990 to 1993 we performed a prospective study of busulfan (16 mg/kg) and cyclophosphamide (120 mg/kg) in 30 patients with refractory anemia (RA) undergoing related (n = 17) or unrelated (n = 13) donor marrow transplantation. Nineteen patients survive disease free (63% 3- year actuarial disease-free survival [DFS]) and no patient relapsed. These results were compared to those of 38 historical controls with RA treated with cyclophosphamide and total body irradiation, of whom 22 are disease-free survivors and 1 relapsed. After correcting for significant variables between the two treatment groups, we found no statistically significant difference in outcome based on preparative regimen. Combining data from these 68 patients plus 2 additional patients with RA treated before 1993 with busulfan and cyclophosphamide, we identified four variables independently associated with improved survival: younger age, shorter disease duration, lower neutrophil count pretransplant, and lower hematocrit pretransplant. We also found that 15 patients 40 to 55 years of age had a 46% 3-year actuarial DFS and 26 patients receiving unrelated or mismatched related donor marrow had a 50% 3-year actuarial DFS. We conclude that there does not appear to be any significant difference in outcome based on preparative regimen in this patient population. In addition, allogeneic bone marrow transplantation may be a reasonable approach to therapy of RA early after diagnosis. However, whether early intervention with transplantation prolongs survival over that expected without transplantation cannot be ascertained with certainty from available data.     

The contribution of psychological distress to socio-economic differences in cause-specific mortality: a population-based follow-up of 28 years

Background  

Psychological factors associated with low social status have been proposed as one possible explanation for the socio-economic gradient in health. The aim of this study is to explore whether different indicators of psychological distress contribute to socio-economic differences in cause-specific mortality.     

Assessment of right ventricular systolic function using tricuspid annular-plane systolic excursion in Nigerians with systemic hypertension

Aim

Right ventricular (RV) systolic function in patients with hypertensive heart disease (HHD) is not well characterised. The primary aim of this study was to assess the systolic function of the right ventricle in patients with HHD using tricuspid annular-plane systolic excursion (TAPSE).

Methods

The study was cross-sectional in design and carried out in Kano, Nigeria. Patients were recruited if they had HHD on echocardiography and were at least 15 years of age. Patients with other cardiac pathologies such as ischaemic and valvular heart diseases were excluded. Patients were considered to have abnormal RV systolic function if they had reduced values of TAPSE (< 15 mm). A p-value of < 0.05 was considered statistically significant.

Results

A total of 186 patients were serially recruited over seven months. Of these, 131 (70.4%) had normal RV systolic function (group 1) and 55 patients (29.6%) had abnormal function (group 2). Group 2 patients were older (p = 0.002) and had a higher prevalence of peripheral oedema (p = 0.002), moderate to severe dyspnoea, higher heart rate and lower left ventricular ejection fraction (p < 0.001). Atrial arrhythmias were also more prevalent among group 2 patients (p < 0.05). The best correlate to TAPSE was the septal mitral annularplane systolic excursion (r = +0.541, p < 0.001). Several variables such as age predicted the presence of reduced TAPSE.

Conclusion

The study found that almost one-third of patients with HHD in Kano had RV systolic dysfunction as defined by reduced TAPSE, and these patients had a greater prevalence of factors associated with morbidity and mortality.     

Optimizing dose and scheduling of filgrastim (granulocyte colony- stimulating factor) for mobilization and collection of peripheral blood progenitor cells in normal volunteers [see comments]

To define an optimal regimen for mobilizing and collecting peripheral blood progenitor cells (PBPC) for use in allogeneic transplantation, we evaluated the kinetics of mobilization by filgrastim (recombinant met- human granulocyte colony-stimulating factor [r-metHuG-CSF]) in normal volunteers. Filgrastim was injected subcutaneously for up to 10 days at a dose of 3 (n = 10), 5 (n = 5), or 10 micrograms/kg/d (n = 15). A subset of volunteers from each dose cohort underwent a 7L leukapheresis on study day 6 (after 5 days of filgrastim). Granulocyte-macrophage colony-forming cell (GM-CFC) numbers in the blood were maximal after 5 days of filgrastim; a broader peak was evident for CD34+ cells between days 4 and 6. The 95% confidence intervals (CI) for mean number of PBPC per milliliter of blood in the three dose cohorts overlapped on each study day. However, on the peak day, CD34+ cells were significantly higher in the 10 micrograms/kg/d cohort than in a pool of the 3 and 5 micrograms/kg/d cohorts. Mobilization was not significantly influenced by volunteer age or sex. Leukapheresis products obtained at the 10 micrograms/kg/d dose level contained a median GM-CFC number of 93 x 10(4)/kg (range, 50 x 10(4)/kg to 172 x 10(4)/kg). Collections from volunteers receiving lower doses of filgrastim contained a median GM- CFC number of 36 x 10(4)/kg (range, 5 x 10(4)/kg to 204 x 10(4)/kg). The measurement of CD34+ cells per milliliter of blood on the day of leukapheresis predicted the total yield of PBPC in the leukapheresis product (r = .87, P < .0001). Assuming a minimum GM-CFC requirement of 50 x 10(4)/kg (based on our experience with autologous PBPC transplantation), all seven leukapheresis products obtained at the 10 micrograms/kg/d dose level were potentially sufficient for allogeneic transplantation purposes. We conclude that in normal donors, filgrastim 10 micrograms/kg/d for 5 days with a single leukapheresis on the following day is a highly effective regimen for PBPC mobilization and collection. Further studies are required to determine whether PBPC collected with this regimen reliably produce rapid and sustained engraftment in allogeneic recipients.