Risk factors for avascular bone necrosis in systemic lupus erythematosus

OBJECTIVE: To study the predictive factors for avascular necrosis (AVN) of bone in patients with systemic lupus erythematosus (SLE). METHOD: The records of 38 SLE patients who developed clinically apparent AVN during the course of their disease were reviewed. Information on clinical presentation, corticosteroid usage and autoantibody profiles was obtained, and comparison was made between these patients and 143 consecutive control SLE patients who did not have AVN. RESULTS: The point prevalence of AVN in our SLE population was 12%. Patients with AVN, when compared with controls, had a significantly higher incidence of neurological disease (39% vs 14%; P < 0.001) and Cushingoid body habitus after steroid treatment (79% vs 53%; P = 0.004). The highest cumulative prednisolone dose in 1 and 4 months was significantly higher in the AVN group than the controls (1.8 vs 1.1 and 4.5 vs 2.8 g, respectively; P < 0.01 in both) and showed a linear trend with the incidence of AVN (chi2 test for trend, P < 0.01 in both). Lupus anticoagulant was associated with AVN (P = 0.02, odds ratio 2.88 [1.14- 7.28]). Logistic regression analysis revealed that the highest cumulative prednisolone dose administered in 4 months, the maximum and mean daily prednisolone dosage, and the lupus anticoagulant were independent risk factors for AVN. CONCLUSIONS: Corticosteroid remains the major predisposing factor for AVN in SLE. Patients who require an initial high-dose steroid for disease control are at risk of AVN, especially if they are positive for the lupus anticoagulant or develop Cushingoid habitus after steroid treatment. High-risk patients should be closely monitored so that early AVN can be diagnosed by sensitive techniques such as magnetic resonance imaging and radioisotope bone scanning.      

Distinct surrogate markers for protection against Plasmodium falciparum infection and clinical malaria identified in a Senegalese community after radical drug cure

Plasmodium falciparum expresses many antigens, which elicit various immune responses in exposed individuals, but no simple surrogate marker for protection has yet been developed. In this prospective survey, we looked for immune responses predictive of protection at various stages of progression from parasite inoculation to onset of disease. We studied 110 Senegalese volunteers from an area in which malaria is mesoendemic after they had received eradication therapy. We evaluated 4 protection-related outcomes (reappearance of parasitemia, duration of asymptomatic carriage, time to first clinical episode, and incidence of clinical episodes) in terms of levels of immunoglobulin G (IgG) against 3 crude parasite extracts and 5 conserved antigens during a 5-month period. Kaplan-Meier estimates and age-adjusted regression models showed these 4 outcomes to be associated with different patterns of IgG response to PfEMP3-cl5 (derived from P. falciparum erythrocyte membrane protein 3), PfEB200, MSP-1(19) (derived from merozoite surface protein-1), [NANP]10, infected red blood cell membrane, and merozoite and schizont extracts. It should, therefore, be possible to develop surrogate markers for each end point on the basis of IgG response to a limited number of conserved antigens.     

delta-Aminolevulinate dehydratase in human erythroleukemia cells: an immunologically distinct enzyme

Physicochemical and immunologic properties of delta-aminolevulinate (ALA) dehydratase in human K562 erythroleukemia cells were examined. ALA dehydratase activity was found to increase in K562 cells after treatment with butyric acid or selenium oxide. Enzyme activity in untreated K562 cells was comparable to that in normal adult erythrocytes but was increased three- to six-fold in K562 cells treated with 1.2 mmol/L butyric acid or 0.03 mmol/L selenium oxide. The Michaelis-Menten constant (Km), the inhibitor constant (Ki), and elution profile by diethylaminoethyl (DEAE) cellulose chromatography were similar for ALA dehydratase from K562 cells and normal human adult and human fetal erythrocytes. However, ALA dehydratase from K562 cells did not react with a monospecific rabbit antibody against ALA dehydratase purified from normal adult erythrocytes, although the antibody reacted with the enzyme from normal adult and fetal red cells. These findings indicate that ALA dehydratase in K562 cells is immunologically distinct from the normal enzyme.     

经肛门内镜显微手术切除直肠肿瘤

目的评价经肛门内镜显微手术(TEM)切除直肠绒毛状腺瘤和早期直肠癌的应用效果。方法分析我院总结1995年11月至2001年12月27例TEM手术的临床资料。结果本组患者肿瘤直径中位值2.5cm,肿瘤下缘与齿状线距离(8.9±3.4)cm,肿瘤侵犯直肠周径范围(35.7±17.5)%。平均手术时间(109±46)min。平均住院日4.5d。无围手术期死亡。手术并发症有尿潴留、暂时性大便失禁和慢性阻塞性肺病(COPD)复发。术中2例切穿至腹腔,即刻内镜下修补成功。切缘100%瘤细胞阴性。病理示直肠绒毛状腺瘤14例、直肠腺癌13例,后者包括pTis2例,pT16例和pT25例。直肠癌腔内超声肿瘤T分期符合率为84.6%。5例pT2中2例中转前切除术,1例接受术后放疗,2例无附加任何治疗。平均随访18个月,所有病例无局部复发。死亡2例,但无复发迹象。结论TEM易行且安全,是直肠绒毛状腺瘤和部分T1直肠癌的治愈性手术,也可作为T2直肠癌的姑息性治疗手段。     

经肛门内镜显微手术治疗直肠绒毛状腺瘤和早期直肠癌31例

目的探讨经肛门内镜显微手术（transanal endoscopicmic rosurgery，TEM）治疗直肠绒毛状腺瘤和早期直肠癌的疗效。方法1995年11月～2003年12月，我院行TEM治疗直肠肿瘤31例。全麻下根据肿瘤位置选择合适的体位，经肛门插入特殊的手术直肠镜，保持CO2充气状态，在立体视镜和腔镜系统下，采用针形电刀或5mm超声刀将直肠肿瘤完整切除（黏膜下或全层切除），手术创口在腔内连续缝合。结果31例直肠肿瘤均获完整切除，切缘均阴性。手术时间45～220min，平均95min；术中出血量0～180ml，平均40ml。手术并发症：暂时性排气失控2例，急性尿潴留1例，慢性阻塞性气道疾病急性发作1例，因服用阿斯匹林而出现继发性出血1例。术后病理分期：pT0期16例，pTis期2例，pT1期7例，pT2和pT3期各3例。31例随访2～92个月，平均23个月，肿瘤无原位复发。结论TEM是治疗直肠绒毛状腺瘤和早期直肠癌的一种安全、有效的微创手术方法。     

Host factors affecting the delay of reappearance of Plasmodium falciparum after radical treatment among a semi-immune population exposed to intense perennial transmission

To investigate host factors affecting the delay of reappearance of malaria parasites after radical treatment, a study was undertaken in Dielmo, Senegal, an area of intense perennial malaria transmission. A 7-day course of quinine was administered to 173 asymptomatic persons from 1 to 85 years of age and reappearance of malaria parasites in the peripheral blood was monitored weekly for 14 weeks. Additional thick blood films were made in case of fever as part of a daily clinical surveillance. The median times before reappearance of Plasmodium falciparum were 22, 39, and 53 days among persons 1-6, 7-14, and > or = 15 years of age, respectively (P < 0.0001). Multivariate analysis indicated that the daily rate of reappearance of P. falciparum was 2.2 (95% confidence interval [CI] = 1.2-4.5) times lower in sickle cell trait carriers than in AA individuals, and 1.5 (95% CI = 1.1-2.1) times lower in bed nets users than in non-users. The risk ratio for the daily risk of reappearance was significantly related to the level of parasitemia before treatment. No influence of glucose-6-phosphate dehydrogenase deficiency, HLA-B53, and DR13 were observed. Findings show that monitoring during a few weeks the reappearance of malaria parasites after treatment among a small cohort of individuals naturally exposed to malaria is relevant for investigating host resistance factors. This suggest that small, low-cost, field trials may be very informative on the potential of new malaria vaccine candidates.