A misleading tumor image

Inflammatory pseudotumors of the lung are uncommon benign lung tumors. Their tendency for local extension requires an exact histopathological diagnosis to rule out neoplastic proliferation. The case presented here highlights the clinical findings as well as the difficulties in making the diagnosis and the therapeutic uncertainties.     

Vaccination history and risk of childhood leukaemia

BACKGROUND: Previous studies on vaccination and childhood leukaemia generated inconsistent results. METHODS: In the Northern California Childhood Leukaemia Study, a case-control study with incident cases and matched birth certificate controls, detailed written vaccination records were collected. A total of 323 cases aged 0-14 years at diagnosis and 409 controls were included in this analysis. All vaccinations were censored on the reference date (date of diagnosis for cases and the corresponding date for matched controls). Conditional logistic regression analysis was conducted, adjusting for potential confounding factors. A primary variable of interest is the number of administrations (doses) of various types of vaccines. RESULTS: Vaccinations against diphtheria, pertussis, tetanus, poliomyelitis, measles, mumps, and rubella were not associated with the risk of leukaemia. The odds ratio for each dose of Haemophilus influenzae type b (Hib) vaccine was 0.81 (95% CI 0.68-0.96). Compared with children who received two or fewer doses of Hib vaccine, those who received three or more doses had a significantly reduced risk of childhood leukaemia (odds ratio = 0.55, 95% confidence interval 0.32-0.94). The number of doses of hepatitis B vaccine received was not associated with leukaemia risk. CONCLUSIONS: Hib vaccination is associated with a reduced risk of childhood leukaemia. Future studies with detailed exposure assessment and large sample sizes are needed to further address the role of vaccinations in the etiology of childhood leukaemia.     

肺癌危险度与非肿瘤肺部疾病关系研究

目的 发现非肿瘤肺部疾病对肺癌危险度的直接影响。方法 在甘肃省进行的病例-对照流行病学研究，涉及到在1994年1月至1998年4月期间发生的886名肺癌病例（男性656名，女性230名）。病例调查表中收集了多种诱发肺癌危险因素的资料。其中包括非肿瘤肺部疾病史（肺结核，慢性气管炎/肺气肿，哮喘，肺炎），初次发病诊断年龄和年份，接受治疗和法院情况等。通过分析这些资料，找出非肿瘤肺部疾病史与肺癌危险度的关系。结果 在对主动吸烟和社会经济因素进行调整后，发现肺癌危险度的增加与肺结核及慢性气管炎/肺气肿直接有关，其比值比（OR）和95%置信区间（CI）分别为OR=2.1(95%CI:1.4-3.1)与OR=1.4(95%CI:1.1-1.8)，哮喘与肺炎也使肺癌OR值增加，其值分别为OR=1.4，（95%CI：0.9-2.1)。与OR=1.5(95%CI:1.0-2.3)。当只对有病理诊断的病例和由本人回答的资料进行分析时，肺结核与慢性气管炎/肺气肿导致肺癌危险度的增加也是显的。结论 本研究提供了新的证据。证明以往的肺结核与慢性气管炎/肺气肿使致肺癌危险度显增加。哮喘和肺炎与肺癌的关系虽然也是正相关。但还没达到统计显水平。     

Catheter ablation of left posteroseptal accessory pathways and of long RP' tachycardias with a right endocardial approach

Fifty-four patients with a posteroseptal accessory connection and symptomatic tachycardias underwent catheter ablation of the anomalous pathway. Eight had the permanent form of reciprocating tachycardias (long RP' tachycardia) and 46 had a left posteroseptal preexcitation marked by a prominent R wave in lead VI. In 14 of 19 patients, ventriculoatrial conduction time during tachycardia lengthened in conjunction with functional left bundle branch block; this behaviour was significantly different from a series of patients with right posteroseptal preexcitation in which functional left bundle branch block lengthened the ventriculoatrial time in only one of 12 patients. A quadripolar electrode catheter was left within the proximal coronary sinus in order to locate the earliest atrial or ventricular activation site. The appropriate bipole was used as the radiographic and electrophysiological reference of the insertion of the accessory pathway. A catheter was then positioned on the septal side of the right atrium, outside the coronary sinus, so that atrial activity during reciprocating tachycardia and ventricular activity during preexcitation were synchronous with or earlier than that recorded within the proximal coronary sinus. Accessory pathway potential was not recorded in any patient. Early ventricular potential occurring --1.5 +/- 8 ms relative to delta wave onset was present at that site. In 38 patients, including 5 with permanent junctional tachycardia, high current (14 mA) pacing yielded direct ventricular paced QRS complexes (no delay spike-QRS) with a morphology similar to left posteroseptal maximal preexcitation. Slight movements of catheter position yielded significantly different pace-maps. One to eight 160 J cathodal shocks (510 +/- 213 J cumulative per patient) were delivered at this site in 61 sessions. Following fulguration, tachycardia recurred without drugs in only one patient over a follow-up period of 20 +/- 13 months. Asymptomatic intermittent preexcitation recurred in two patients. In all patients with long RP' tachycardia, the ablation procedure was successful without the need for drugs or permanent cardiac pacing. A long-term follow-up electrophysiological study in 18 patients demonstrated that conduction through the anomalous pathway was absent in 16 and deeply altered in the two patients with intermittent preexcitation; no tachycardia was inducible in any patient. In conclusion, catheter ablation of left posteroseptal accessory pathways is a feasible procedure using a right atrial approach outside the coronary sinus. This technique is also effective for the treatment of the permanent form of reciprocating tachycardia.     

Determination of clomipramine and desmethyl-clomipramine in plasma or urine by the double-radioisotope derivative technique.

A double radioisotope derivative method was developed for the determination of clomipramine and desmethyl-clomipramine in plasma or urine. After addition of 14C-labeled clomipramine and desmethyl-clomipramine as internal standards and extractive isolation of both compounds, desmethyl-clomipramine is acetylated with [3H]acetic anhydride. The [3H]acetamide is separated from clomipramine by thin-layer chromatography and its radioactivity is measured. Clomipramine, extracted from the cilica gel, is reacted with trichloroethyl chloroformate. The urethane is saponified and decarboxylated. The resulting desmethyl-clomipramine is acetylated with [3H]acetic anhydride. The [3H]acetamide is purified by thin-layer chromatography and its radioactivity is measured. The sensitivity of the method is 15 mug/liter for clomipramine and 2 mug/liter for desmethyl-clomipramine. Its specificity was made sure by a cross-check with a gas chromatography-mass spectrometry technique.     

Cytogenetics of Hispanic and White children with acute lymphoblastic leukemia in California.

Epidemiologic studies of childhood leukemia have made limited use of tumor genetic characteristics, which may be related to disease etiology. We characterized the cytogenetics of 543 childhood leukemia patients (0-14 years of age) enrolled in the Northern California Childhood Leukemia Study, an approximately population-based study comprised primarily of Hispanics (42%) and non-Hispanic Whites (41%), and compared the cytogenetic profiles between these two ethnic groups. Subjects were classified by immunophenotype, conventional cytogenetic characteristics, and fluorescence in situ hybridization findings. The ploidy levels most frequently observed among acute lymphoblastic leukemia patients were high hyperdiploidy (51-67 chromosomes) and pseudodiploidy (34% and 27%, respectively). No ethnic differences in the frequency of 11q23/MLL rearrangements were observed between Hispanics and non-Hispanic Whites. Among B-lineage acute lymphoblastic leukemia patients, the percentage of TEL-AML1 translocations was significantly lower in Hispanics (13%) than in non-Hispanic Whites (24%; P = 0.01). This is the first time that this ethnic variation has been observed in a large number of patients in a defined geographic region, which is consistent with findings from smaller international studies. The mechanistic basis for this 2-fold variation in frequency of TEL-AML1 may be due to ethnic-specific risk factors or genetics and should be explored further.     

Impact of chronic GVHD therapy on the development of squamous-cell cancers after hematopoietic stem-cell transplantation: an international case-control study

Previous studies of recipients of hematopoietic stem-cell transplants suggest that graft-versus-host disease (GVHD) and its therapy may increase the risk for solid cancers, particularly squamous-cell carcinomas (SCCs) of the buccal cavity and skin. However, the importance and magnitude of these associations are not well characterized. We conducted a case-control study of 183 patients with posttransplantation solid cancers (58 SCCs, 125 non-SCCs) and 501 matched control patients within a cohort of 24,011 patients who underwent hematopoietic stem-cell transplantation (HSCT) at 215 centers worldwide. Our results showed that chronic GVHD and its therapy were strongly related to the risk for SCC, whereas no increase in risk was found for non-SCCs. Major risk factors for the development of SCC were long duration of chronic GVHD therapy (P < .001); use of azathioprine, particularly when combined with cyclosporine and steroids (P < .001); and severe chronic GVHD (P = .004). Given that most patients who received prolonged immunosuppressive therapy and those with severe chronic GVHD were also treated with azathioprine, the independent effects of these factors could not be evaluated. Additional analyses determined that prolonged immunosuppressive therapy and azathioprine use were also significant risk factors for SCC of the skin and of the oral mucosa. These data provide further encouragement for strategies to prevent chronic GVHD and for the development of more effective and less carcinogenic treatment regimens for patients with moderate or severe chronic GVHD. Our results also suggest that clinical screening for SCC is appropriate among patients exposed to persistent chronic GVHD, prolonged immunosuppressive therapy, or both.     

Microbiologic characteristics and in vitro susceptibility to antimicrobials in a large population of patients with cardiovascular implantable electronic device infection

Microbiologic Characteristics and In Vitro Susceptibility to Antimicrobials. Introduction: The incidence of cardiovascular implantable electronic device (CIED) infection is steadily increasing. However, no consensus has been reached with respect to the type and duration of antimicrobial therapy in this specific population of patients. The role played by new anti‐Staphylococcus agents has not been defined. The aims of this study were to describe the microbiological characteristics of a large population of patients with CIED infections and to test the in vitro susceptibility of the various strains to different antimicrobials. Methods: Two hundred eighty‐six patients with CIED infection were included. The minimal inhibitory concentrations of 9 antimicrobials, including linezolid, tigecycline, and daptomycin were measured against all strains of staphylococci isolated. Results: Microbiologic confirmation was obtained in 252 (88%) patients, the vast majority were from Staphylococcus species (86%), 90% of these were coagulase negative strains and 10% were Staphylococcus aureus; 30.5% were methicillin‐resistant. All strains were susceptible to vancomycin, nearly 15% of coagulase negative strains were nonsusceptible to teicoplanin, and nearly 100% of the strains were susceptible to the 3 new antimicrobials. Conclusions: In this large contemporary study, we show that Staphylococcus is by far the most common cause of CIED infections, with the majority due to coagulase negative strains. Methicillin‐resistance is common in this population. Currently, we would recommend vancomycin as first‐line empirical therapy. However, given that not all patients tolerate vancomycin, we believe that newer antimicrobial therapies should now be tested in clinical trials to establish their clinical effectiveness in treating patients with device infections.