Kidney transplantation in patients with Wilms' tumor.

We report our experience of renal transplantation in three patients treated for Wilms' tumor (with lung metastasis in two of them), and review 26 previously reported cases in order to define the current indications of transplantation in this setting. Our patients, aged 5-12 years, were transplanted 13-95 months after completion of Wilms' tumor treatment. All three are alive and tumor-free, two with a functioning graft 20 and 97 months after transplantation. Two findings emerge from the review of the literature. First, posttransplant mortality is influenced by the delay between completion of tumor treatment and transplantation. Mortality reaches 79% when that delay is less than one year but falls to 27% when that delay exceeds one year. Second, the prognostic value of pretransplant metastasis depends on its location. All four patients with pretransplant abdominal metastasis died with active metastatic disease. By contrast, of three patients treated before transplantation for metastasis confined to the lung, two are alive and tumor free. We conclude that renal transplantation should be offered to patients successfully treated for Wilms' tumor for at least one year, even if the disease has been complicated by pulmonary metastasis. Several long-term survivors attest that the disease can be cured even under maintenance immunosuppression.     

Ischemic stroke complicating cardiac catherization: case report.

Ischemic stroke occurs in 0.2-0.4% of patients undergoing left heart catheterization, and is responsible for 5-10% of the mortality associated with the procedure. The main predisposing factors for this complication are female gender, complex atherosclerotic plaques in the ascending aorta, and peripheral arterial disease. The possibility of timely intervention with reperfusion therapy supports close clinical monitoring during the immediate post-catheterization period. The cardiologist should be familiar with the various types of stroke reperfusion therapy and its indications according to the time interval between catheterization and the stroke. The decision should be discussed with neurology and neuroradiology.     

Skinfold thickness versus isotope dilution for body fat assessment during simulated microgravity: results from three bed-rest campaigns in men and women with and without countermeasures

Because body composition is altered during head-down bed rest (HDBR), body mass can not be used as an index of energy balance. Consequently diet allowances should not be based on body mass evolution but on fat mass changes. Though criticized, skinfold thickness (ST) is the costless, easiest and fastest method to use for such an objective. The aim of this study was to compare the percentage of body fat (%BF) estimated by ST with the isotope dilution of H₂¹⁸O. We compiled data from three HDBR campaigns, one on women (n=8) in November 1998 and two on the same men (n=8) in December 1997 (without countermeasure) and January 1998 (with thigh-cuffs countermeasure), according to a crossover design. Body composition was assessed before and after 6 days of HDBR. %BF was derived from the biceps, triceps, sub-scapular and sup-iliac ST according to Durnin and Wormersly (1974). Fat-free mass was measured on the same day by H₂¹⁸O dilution and fat mass was calculated by the difference with body mass and expressed as a percentage. Based on precision tests, the minimum measurable change by ST was 1.1%BF for single measurement point. Both intercepts (F _4,30=0.89, P=0.45) and slopes (F _4,30=0.74; P=0.57) of the ST versus dilution relationships were not affected by the periods (December vs January), experimental conditions (control vs HDBR vs HDBR + thigh cuffs) or sex allowing the derivation of a common relationship %BF_st=0.94 × %BF_dil (F _1,47=97.9, P<0.0001; non-significant intercept excluded) with a bias between methods of −1.7±2.0 %BF (95% CI: −5.8, 2.4 %BF). ST can be used to measure %BF during HDBR provided great care is placed on training and changes are higher than 1.1 %BF. If the method can be applied for in-flight energy balance monitoring given the high observed energy deficit, a tight monitoring of the individual nutritional status as needed during simulation appears, however, dubious based on this solely method.     

Isolation of exfoliated colonocytes from human stool as a new technique for colonic cytology

Cell exfoliation in the gut is an important cell renewal mechanism. To approach its investigation we applied a novel immunomagnetic technique for isolation of exfoliated cells from human stool. Exfoliated colonocytes were isolated from 168 stool samples. The cells were assessed microscopically using conventional stains and immunohistochemistry. The technique allowed us to obtain well-preserved colonocytes displaying characteristic features of well-differentiated colonic epithelium and positive immunostaining for cytokeratin 5/8. No mucin-producing cells were found. Exfoliated cells did not produce inducible nitric oxide synthase, albeit cultured colon carcinoma cells HT-29 analysed in parallel showed strong immunostaining. Analysis of exfoliated cell numbers in consecutive stool samples from the same subjects revealed considerable interindividual variation. Overall exfoliated colonocyte numbers were relatively low, isolation being unaffected by addition during the procedure of excessive amounts of HT-29 cells. Apoptosis was extremely rare among exfoliated colonocytes. Well-preserved exfoliated colonocytes can be consistently isolated from human faeces using a simple procedure. Our findings suggest that the actual process of cell exfoliation in the human colon may be much less intense than is generally accepted. Exfoliated cell isolation from human stool constitutes a convenient non-invasive approach that can be used for diagnostic and research purposes.     

Dual role of interleukin-4 (IL-4) in pulmonary paracoccidioidomycosis: endogenous IL-4 can induce protection or exacerbation of disease depending on the host genetic pattern

Resistance to paracoccidioidomycosis, the most important endemic mycosis in Latin America, is thought to be primarily mediated by cellular immunity and the production of gamma interferon. To assess the role of interleukin-4 (IL-4), a Th2 cytokine, pulmonary paracoccidioidomycosis in IL-4-depleted susceptible (B10.A) and intermediate (C57BL/6) mice was studied. Two different protocols were used to neutralize endogenous IL-4 in B10.A mice: 1 mg of anti-IL-4 monoclonal antibody (MAb)/week and 8 mg 1 day before intratracheal infection with 10(6) Paracoccidioides brasiliensis yeast cells. Unexpectedly, both protocols enhanced pulmonary infection but did not alter the levels of pulmonary cytokines and specific antibodies. Since in a previous work it was verified that C57BL/6 mice genetically deficient in IL-4 were more resistant to P. brasiliensis infection, we also investigated the effect of IL-4 depletion in this mouse strain. Treatment with the MAb at 1 mg/week led to less severe pulmonary disease associated with impaired synthesis of Th2 cytokines in the lungs and liver of control C57BL/6 mice. Conversely, in IL-4-depleted C57BL/6 mice, increased levels of tumor necrosis factor alpha and IL-12 were found in the lungs and liver, respectively. In addition, higher levels of immunoglobulin G2a (IgG2a) and lower levels of IgG1 antibodies were produced by IL-4-depleted mice than by control mice. Lung pathologic findings were equivalent in IL-4-depleted and untreated B10.A mice. In IL-4-depleted C57BL/6 mice, however, smaller and well-organized granulomas replaced the more extensive lesions that developed in untreated mice. These results clearly showed that IL-4 can have a protective or a disease-promoting effect in pulmonary paracoccidioidomycosis depending on the genetic background of the host.     

Risk factors for asthma among children in Maputo (Mozambique)

BACKGROUND: Few studies have looked at risk factors for asthma in African children. We aimed to identify the risk factors associated with childhood asthma in Maputo (Mozambique). METHODS: This case-control study included 199 age-matched children (100 asthmatic and 99 nonasthmatic) who attended Maputo Central Hospital between January 1999 and July 2000. We collected information concerning their familial history of atopy, birth weight, environment and breast-feeding. Detailed information about morbidity and treatment was obtained for each asthmatic child. RESULTS: The children were aged between 18 months and 8 years; 60% were male. The asthmatic children were hospitalized more frequently than the nonasthmatic children (P < 0.0001). Most of the asthmatic children lived in the urban area of Maputo [odd ratio (OR) = 6.73, CI = 3.1-14.0, P < 0.0001], had a parental history of asthma (OR = 26.8, CI = 10.8-68.2, P < 0.0001) or rhinitis (OR = 4, CI = 1.2-13.3, P = 0.005), had at least parent who smoked and were weaned earlier than the nonasthmatic children (OR = 2.4, CI = 1.3-4.4, P < 0.001). CONCLUSION: Childhood asthma was strongly associated with a family history of asthma and rhinitis, the place of residence, having smokers as parents and early weaning from maternal breast milk. These results highlight the need to reassess the management of asthmatic children in Maputo.