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BACKGROUND Personalized nutrition and protective diets and lifestyles represent a key cancer research priority. The association between consumption of specific dietary components and colorectal cancer (CRC) incidence has been evaluated by a number of population-based studies, which have identified certain food items as having protective potential, though the findings have been inconsistent. Herein we present a systematic review and meta-analysis on the potential protective role of five common phytochemically rich dietary components (nuts, cruciferous vegetables, citrus fruits, garlic and tomatoes) in reducing CRC risk. AIM To investigate the independent impact of increased intake of specific dietary constituents on CRC risk in the general population. METHODS Medline and Embase were systematically searched, from time of database inception to January 31, 2020, for observational studies reporting CRC incidence relative to intake of one or more of nuts, cruciferous vegetables, citrus fruits, garlic and/or tomatoes in the general population. Data were extracted by two independent reviewers and analyzed in accordance with the Meta-analysis of Observational Studies in Epidemiology (MOOSE) and Preferred Reporting Items for Systematic Review and Meta-analysis (PRISMA) reporting guidelines and according to predefined inclusion/exclusion criteria. Effect sizes of studies were pooled using a random-effects model. RESULTS Forty-six studies were identified. CRC risk was significantly reduced in patients with higher vs lower consumption of cruciferous vegetables [odds ratio (OR) = 0.90; 95% confidence interval (CI): 0.85-0.95; P < 0.005], citrus fruits (OR = 0.90; 95%CI: 0.84-0.96; P < 0.005), garlic (OR = 0.83; 95%CI: 0.76-0.91; P < 0.005) and tomatoes (OR = 0.89; 95%CI: 0.84-0.95; P < 0.005). Subgroup analysis showed that this association sustained when looking at case-control studies alone, for all of these four food items, but no significant difference was found in analysis of cohort studies alone. Nut consumption exhibited a similar trend, but overall results were not significant (OR = 0.72; 95%CI: 0.50-1.03; P < 0.07; I2 = 90.70%). Putative anticarcinogenic mechanisms are proposed using gene-set enrichment analysis of gene/protein perturbations caused by active compounds within each food item. CONCLUSION Increased cruciferous vegetable, garlic, citrus fruit and tomato consumption are all inversely associated with CRC risk. These findings highlight the potential for developing precision nutrition strategies for CRC prevention. Borgas P, Gonzalez G, Veselkov K, Mirnezami R. Phytochemically rich dietary components and the risk of colorectal cancer: A systematic review and meta-analysis of observational studies. World J Clin Oncol 2021; 12(6): 482-499 [PMID: 34189071 DOI: 10.5306/wjco.v12.i6.482]

Introduction The only curative treatment for severe aplastic anemia in children is an allogeneic stem cell transplant; however, few patients have a matched related or unrelated donor. Haploidentical stem cell transplantation (haplo-SCT) using bone marrow (BM) and peripheral blood stem cells (PBSC) has been recently described as effective and safe. In this study, we retrospectively report the outcome of twelve pediatric patients who underwent haplo-SCT using only PBSC. Methods The conditioning regimen consisted on rabbit anti-thymocyte globulin (r-ATG) 2.5 mg/kg/d on days -7, -6,-5, and -4, and cyclophosphamide (Cy) 50 mg/kg/d on days -3 and -2. We used Cy 50 mg/kg/d on days +3 and +4, tacrolimus and mycophenolic acid as graft versus host disease (GVHD) prophylaxis. Results The median follow-up was 1,099 days (45-1258 days). The overall survival rate up-to-date is 83.3%. In 10 of the 12 patients, a sustained graft was achieved. None of the patients had acute or chronic GVHD. Conclusions Haplo-SCT could be established as a first-line treatment when there is no matched related or unrelated donor. According to this short sample and previous reports, PBSC are a feasible option effectively used as the sole source of stem cells. Additionally, post-transplant cyclophosphamide remains a good strategy for GVHD prevention.

Background Recent efforts in the field of nutritional science have allowed the discovery of disease-beating molecules within foods based on the commonality of bioactive food molecules to FDA-approved drugs. The pioneering work in this field used an unsupervised network propagation algorithm to learn the systemic-wide effect on the human interactome of 1962 FDA-approved drugs and a supervised algorithm to predict anticancer therapeutics using the learned representations. Then, a set of bioactive molecules within foods was fed into the model, which predicted molecules with cancer-beating potential.The employed methodology consisted of disjoint unsupervised feature generation and classification tasks, which can result in sub-optimal learned drug representations with respect to the classification task. Additionally, due to the disjoint nature of the tasks, the employed approach proved cumbersome to optimize, requiring testing of thousands of hyperparameter combinations and significant computational resources.To overcome the technical limitations highlighted above, we represent each drug as a graph (human interactome) with its targets as binary node features on the graph and formulate the problem as a graph classification task. To solve this task, inspired by the success of graph neural networks in graph classification problems, we use an end-to-end graph neural network model operating directly on the graphs, which learns drug representations to optimize model performance in the prediction of anticancer therapeutics. Results The proposed model outperforms the baseline approach in the anticancer therapeutic prediction task, achieving an F1 score of 67.99%±2.52% and an AUPR of 73.91%±3.49%. It is also shown that the model is able to capture knowledge of biological pathways to predict anticancer molecules based on the molecules’ effects on cancer-related pathways. Conclusions We introduce an end-to-end graph convolutional model to predict cancer-beating molecules within food. The introduced model outperforms the existing baseline approach, and shows interpretability, paving the way to the future of a personalized nutritional science approach allowing the development of nutrition strategies for cancer prevention and/or therapeutics.

Introduction The only curative treatment for severe aplastic anemia in children is allogenic stem cell transplantation, but only few patients have a matched related or unrelated donor. Haploidentical stem cell transplantation (haplo-SCT) using bone marrow (BM) and peripheral blood stem cells (PBSC) has been recently described as effective and safe. In this study, we retrospectively describe the outcome of nine pediatric patients who underwent haplo-SCT using only PBSC. Patients and methods The father was the selected donor for seven of the nine patients. Donor specific anti-HLA antibodies were ruled out. Stem cells mobilization was performed with filgrastim 10 mcg/kg/d for five days, and CD34+ were recollected by peripheral blood apheresis on day 0. The conditioning regimen consisted on rabbit anti-thymocyte globulin 2.5 mg/kg/d on days -7, -6, -5, and -4, and cyclophosphamide 50 mg/kg/d on days -3 and -2. We used cyclophosphamide 50 mg/kg/d on days +3 and +4, tacrolimus and mycophenolic acid as graft versus host disease prophylaxis. Results The median follow up was 253 days (range 45-765 days). The median infused CD34+ was 10 × 10^6/kg (range 2.7 to 43 × 10^6/kg). The median myeloid engraftment was day +15 (range 11-30 days), and median platelet engraftment was day +16 (range 12-30 days). In eight of the nine patients, a sustained graft was achieved. One patient never achieved platelet engraftment and died because of cytomegalovirus infection. There was not treatment related toxicity reported. None of the patients had GVHD. The overall survival up to date is 88.8%. The eight surviving patients remain free of transfusions. Conclusions Haplo-SCT could be established as first line treatment when there is no matched related or unrelated donor. According to this short sample and previous reports, PBSC is a feasible option to be effectively used as only source of stem cells.

Recent data indicate that up-to 30–40% of cancers can be prevented by dietary and lifestyle measures alone. Herein, we introduce a unique network-based machine learning platform to identify putative food-based cancer-beating molecules. These have been identified through their molecular biological network commonality with clinically approved anti-cancer therapies. A machine-learning algorithm of random walks on graphs (operating within the supercomputing DreamLab platform) was used to simulate drug actions on human interactome networks to obtain genome-wide activity profiles of 1962 approved drugs (199 of which were classified as “anti-cancer” with their primary indications). A supervised approach was employed to predict cancer-beating molecules using these ‘learned’ interactome activity profiles. The validated model performance predicted anti-cancer therapeutics with classification accuracy of 84–90%. A comprehensive database of 7962 bioactive molecules within foods was fed into the model, which predicted 110 cancer-beating molecules (defined by anti-cancer drug likeness threshold of >70%) with expected capacity comparable to clinically approved anti-cancer drugs from a variety of chemical classes including flavonoids, terpenoids, and polyphenols. This in turn was used to construct a ‘food map’ with anti-cancer potential of each ingredient defined by the number of cancer-beating molecules found therein. Our analysis underpins the design of next-generation cancer preventative and therapeutic nutrition strategies.

Background The aim of this study was to evaluate the results of video-assisted mediastinoscopic lymphadenectomy (VAMLA) for staging of non-small cell lung cancer (NSCLC). Methods This was a prospective observational study of all consecutive VAMLAs performed from January 2010 to April 2015 for staging NSCLC. For left lung cancers, extended cervical videomediastinoscopy was added to explore the subaortic and paraaortic nodes. Patients with negative VAMLA results underwent tumor resection and lymphadenectomy of the remaining nodes. Those with N2–3 disease underwent chemoradiation. The rate of unsuspected pathologic (p)N2–3 was analyzed in the global series and in the subgroups of patients according to their nodal status diagnosed by imaging and metabolic techniques. Results One hundred sixty VAMLAs were performed for staging NSCLC (138 tumors were clinical (c)N0-1 based on imaging techniques). The rate of unsuspected N2–3 disease was 18% for the whole series: 40.7% for cN1, 22.2% for cN0 and tumor size greater than or equal to 3 cm, and 6.4% for cN0 and tumor size less than 3 cm. Staging values were sensitivity, 0.96 (95% confidence interval [CI], 0.81–99.3); specificity, 1 (95% CI, 0.97–1); positive predictive value, 1 (95% CI, 0.87–1); negative predictive value, 0.99 (95% CI, 0.95–0.99); and diagnostic accuracy, 0.99 (95% CI, 0.96–0.99). The complication rate was 5.9%. Conclusions VAMLA is a feasible and highly accurate technique. The high rate of unsuspected mediastinal node disease diagnosed by VAMLA in patients with cN1 or cN0 disease and tumor size larger than 3 cm suggests that preresection lymphadenectomies should be included in the current staging algorithms.

Bone disease in rheumatoid arthritis (RA) is a complex phenomenon where genetic risk factors have been partially evaluated. The system formed by receptor activator for nuclear factor-κB (RANK), receptor activator for nuclear factor-κB ligand (RANKL), and osteoprotegerin (OPG): RANK/RANKL/OPG is a crucial molecular pathway for coupling between osteoblasts and osteoclasts, since OPG is able to inhibit osteoclast differentiation and activation. We aim to evaluate the association between SNPs C950T (rs2073617), C209T (rs3134069), T245G (rs3134070) in theTNFRSF11B(OPG) gene, and osteoporosis in RA. We included 81 women with RA and 52 healthy subjects in a cross-sectional study, genotyped them, and measured bone mineral density (BMD) at the lumbar spine and the femoral neck. Mean age in RA was50±12with disease duration of12±8years. According to BMD results, 23 (33.3%) were normal and 46 (66.7%) had osteopenia/osteoporosis. We found a higher prevalence of C allele for C950T SNP in RA. Polymorphisms C209T and T245G did not reach statistical significance in allele distribution. Further studies including patients from other regions of Latin America with a multicenter design to increase the sample size are required to confirm our findings and elucidate if C950T SNP could be associated with osteoporosis in RA.

Objective. There is a lack of information about the genotype frequencies of IL-6 −174G/C and −572G/C polymorphisms in Mexicans with rheumatoid arthritis (RA). Therefore, the aim of this study was to evaluate the association of the IL-6 −174G/C and −572G/C polymorphisms in Mexican mestizo with RA.Methods. We included 137 patients with RA and 102 healthy controls. Patients were assessed for clinical characteristics. IL-6 −174G/C and −572G/C polymorphisms were genotyped using PCR-RFLP analysis. Allele and genotype frequencies and the Hardy-Weinberg equilibrium were computed. Odds ratios (ORs) were computed to identify the risk for RA associated with the presence of GG genotype in comparison with the GC or CC genotypes.Results. The genotype −174GG occurred at a higher frequency in cases and controls (77.4% versus 78.4%,P=0.845). We found similar results for the genotype −572GG (54% in patients versus 60.8% in controls,P=0.295).Conclusions. This is the first study to evaluate the association of −174G/C and −572G/C polymorphisms of the IL-6 gene with RA in Mexican mestizo patients. These two polymorphisms were not associated with RA in the studied sample. Additional studies are required to evaluate if these IL-6 polymorphisms have relevance to the development of more severe disease.

Glucocorticoids are frequently used in rheumatoid arthritis (RA) in order to alleviate symptoms of joint inflammation, retard erosions and to treat extra-articular manifestations, although these drugs may increase the risk of bone mineral loss and osteoporotic fractures. To date, in Mexico there are no studies that identify the frequency of patients with RA with corticosteroids, receiving therapy for osteoporosis. Therefore, we evaluated the prevalence and factors related to the prescription of antiresorptives in 520 Mexican patients with RA. We used a multivariate model to identify variables associated with antiresorptives prescription. We identified that although 79% of patients were under treatment with glucocorticoids, only 13% received antiresorptive agents as preventive therapy for osteoporosis. The multivariate analysis identified that higher proportions of antiresorptive drugs prescriptions were associated with female patients (OR 11.40, 95% CI: 1.5-84.3, P = 0.02), an age of 40 years or more (OR 3.22, 95% CI: 1.3-8.3, P = 0.02) and to consume a lower number of cointerventions with other drugs (OR 1.09, 95% CI: 1.0-1.2, P = 0.03). Corticosteroid treatment was not associated with the prescription of antiresorptives (P = 0.31). In conclusion, a low proportion of Mexicans with RA receive antiresorptive therapy independently regardless of whether they consume or not chronically corticosteroids. Additional strategies should be evaluated to encourage the prevention and early treatment for osteoporosis in patients with RA.

Objective: To evaluate the accuracy of repeat mediastinoscopy (reMS) in all its indications, and to analyse survival in the group of patients who underwent induction chemotherapy or chemoradiotherapy for pathologically proven stage III-N2 non-small-cell lung cancer (NSCLC). Methods: From July 1992 to February 2009, 96 patients (87 men; median age: 61.3 years), underwent 101 reMSs (five patients required a second reMS) for the following indications: restaging after induction therapy for pathologically proven N2 disease (84 cases), inadequate first mediastinoscopy (five), metachronous second primary (six) and recurrent lung cancer (six). Patients with N2-NSCLC, who had received induction therapy and had positive reMS, underwent definitive chemotherapy or chemoradiotherapy. Patients in whom reMS was negative underwent thoracotomy for lung resection and systematic nodal dissection (SND). SND was considered the gold standard to compare the negative results of reMS. Pathologic findings were reviewed and staging values were calculated using the standard formulas. Follow-up data were completed in January 2010, and survival analysis was performed by the Kaplan—Meier method.Results:InthegroupofreMSforrestagingafterinductiontherapy,thestagingvalues were:sensitivity0.74,specificity1,positivepredictivevalue1,negativepredictivevalue0.79anddiagnosticaccuracy0.87.Wealsodeterminedthe diagnostic value of this technique according to the type of induction treatment. In terms of accuracy, no statistically significant differences were found.Mediansurvival timeinpatientswithtruenegativereMSwas51.5months(95%confidenceinterval(CI) 0—112), and inthe combinedgroup of patients with positive and false-negative reMS, median survival time was 11 months (95% CI 7.6—14.1) ( p = 0.0001). In the group of miscellaneous indications,allstagingvalueswere1.Conclusion:ReMSisfeasibleinalltheindicationsdescribed.Afterinductiontherapy,itisausefulprocedureto selectpatientsforlungresectionwithhighaccuracy,independentlyoftheinductiontreatmentusedortheintensityofthefirstmediastinoscopy.The persistence of lymph node involvement after induction therapy has a poor prognosis. Therefore, techniques providing cytohistological evidence of nodal downstaging are advisable to avoid unnecessary thoracotomies. # 2010 European Association for Cardio-Thoracic Surgery. Published by Elsevier B.V. All rights reserved.

Objective: To evaluate the technical feasibility and the sensitivity, specificity and accuracy of extended cervical mediastinoscopy (ECM) in the staging of bronchogenic carcinoma (BC) of the left lung. Methods: From 1998 to 2003, 89 patients underwent routine ECM for staging of BC of the left lung. In 2004, positron emission tomography (PET) was included in our staging protocol and ECM was reserved for those with positive mediastinal or hilar PET images, large lymph nodes on computed tomography (CT) scan or central tumours. From 2004 to 2007 we performed selective ECM in 67 patients. ECM was considered positive when metastatic nodes or tumour involvement directly in the subaortic or para-aortic regions was confirmed pathologically. One hundred and forty-three patients with negative ECM underwent subsequent thoracotomy for tumour resection and systematic nodal dissection. Pathological findings were reviewed and staging values were calculated. Results: One hundred and fifty-six patients underwent ECM (89 routine and 67 selective). In 13, ECM was positive and thoracotomy was contraindicated. The rest of the patients were operated. We performed 88 lobectomies, 34 pneumonectomies, 6 wedge resections, 13 exploratory thoracotomies and 2 parasternal mediastinotomies. Lymphadenectomy specimens showed tumour involvement of subaortic lymph nodes in 8 patients. Complication rate was 2%: two cases of mediastinitis, one ventricular fibrillation, and one superficial surgical wound infection. Sensitivity, specificity, positive predictivevalue,negativepredictivevalueandaccuracyofroutine/selectiveECMwere:0.45/0.75,1/1,1/1,0.94/0.95,0.94/0.95,respectively. Conclusion:ECMis a feasiblestagingtechnique thatallowsruling outsubaorticandpara-aorticnodaldiseasewith highnegativepredictivevalue, accuracyandsensitivity.ItsindicationbasedontheCTandPETfindingsseemsmoreadvisablethatitsroutineusetostagebronchogeniccarcinoma of the left lung. # 2008 European Association for Cardio-Thoracic Surgery. Published by Elsevier B.V. All rights reserved.

This study explored how Latinas diagnosed with a breast abnormality suspicious for cancer define and use social support while undergoing diagnostic follow-up and/or awaiting a definitive diagnosis. Qualitative data was collected and analyzed from 15 telephone interviews with Spanish-speaking women diagnosed with a breast abnormality suspicious for cancer. Findings indicated that social support was perceived as the comfort, caring, and esteem a person receives from others. With respect to family support, half of the participants felt female family members (e.g., daughters, mothers) were more supportive than male family members (e.g., fathers, sons) when discussing their illness. Many participants felt that asking for help from family members, friends, and health professionals was acceptable under medical circumstances and less justifiable under non-medical circumstances. In conclusion, our findings suggest that Latinas diagnosed with a breast abnormality suspicious for breast cancer are more likely to seek support from family members, friends and health professional after a definitive diagnosis has been given. Additional research is needed to assess the impact of social support in increasing adherence to diagnostic follow-up procedures for a breast abnormality.

Hematopoietic SCT (HSCT) has become an established therapy for numerous disorders of the hematopoietic system and for some solid tumors.1 However, owing to the high cost of the procedure, and the need for a multidisciplinary team, few centers in developing countries provide this treatment modality. In Mexico, the history of HSCT began in 1980, when the first transplant took place at the National Institute of Nutrition in Mexico City. After this, there were a few other procedures in the National Medical Center of the University Hospital of Monterrey, with poor results. This resulted in the suspension of the HSCT program at these institutions. As a result, the practice of HSCT in Mexico was almost anecdotal until 1995.2 As there has been no national report, we consider it important to evaluate the current activity, needs and perspectives in the field of HSCT.

The aim of this study was to compare acid-fast bacilli smear and chromatographic immunoassay in patients with active tuberculosis (TB). The ability to rapidly detect tubercle bacilli in respiratory secretions was determined for the acid-fast bacilli (AFB) smear in comparison with chromatographic immunoassay in serum samples. A total of 96 respiratory specimens and 96 serum samples were evaluated. The chromatographic immunoassay and AFB were positive in six patients (6.25%) and negative in 90 of 96 specimens (93.75%). The sensitivity, specificity, positive predictive value and negative predictive value of chromatographic immunoassay and AFB were 100%. These results demonstrated the clinical usefulness of chromatographic immunoassay assay for the rapid diagnosis of TB in serum. And compared with the AFB smear, the chromatographic immunoassay assay gives a successful diagnosis. Key words: Tuberculosis, chromatographic immunoassay, acid-fast bacilli smear.

OBJECTIVE: The objective of this study is to evaluate the accuracy of extended cervical mediastinoscopy (ECM) in the staging of bronchogenic carcinoma (BC) of the left lung based on our updated experience. METHODS: From 1998 to 2003, 89 patients underwent routine ECM for staging of BC of the left lung. In 2004, routine positron emission tomography (PET) was included in our staging protocol and ECM was reserved for those with positive mediastinal or hilar PET images, large lymph nodes on computed tomography (CT) scan or central tumours. Following this protocol, from 2004 to 2010, we performed 132 selective ECM. ECM was considered positive when metastatic nodes or tumour involvement directly in the subaortic or para-aortic regions was confirmed pathologically. Patients with negative ECM underwent subsequent thoracotomy for tumour resection and systematic nodal dissection (SND). RESULTS: Two hundred and twenty-one ECMs were performed from 1998 to 2010 (89 routine and 132 selective). In the routine ECM protocol, four cases were positive and thoracotomy was contraindicated. The remaining 85 patients were operated and five had nodal disease in subaortic (LN5) or para-aortic (LN6) stations. In the selective ECM protocol (n= 188), 132 patients underwent ECM and in 19 it was positive; the remaining 113 patients underwent thoracotomy and SND found involved LN5 or LN6 in six patients; the other 56 patients underwent direct thoracotomy and four had positive LN5 or LN6. Sensitivity, specificity, positive predictive value, negative predictive value and accuracy of ECM were 0.67, 1, 1, 0.94 and 0.95, respectively. The staging values of routine/selective ECM protocols were 0.44/0.65, 1/1, 1/1, 0.94/0.94 and 0.94/0.95, respectively. CONCLUSIONS: Selective ECM protocol according to CT and PET findings has high negative predictive value and accuracy. Therefore, its selective use is recommended because it saves around 30% ECM without decreasing staging values of the current protocol.

Examined substance abuse rates among subgroups of Mexican-American students by comparing alcohol and drug use rates of Mexican-American adolescents born in the United States to those of Mexican-American students born in Mexico and to Caucasian students attending the same schools. A total of 3,404 ninth- and 11th-grade students were surveyed using the California Substance Use Sunrey (Skager, Austin, & Firth, 1991; Skager, Firth, & Maddahian, 1989). It was found that Mexican females abstain the most from drug and alcohol use. Mexican males also reported lower drug and alcohol use than their Mexican-American and Caucasian counterparts, who had similar rates of alcohol we. In terms of prevention and intervention, Caucasian ninth graders reported the highest percentages receiving a substance abuse prevention program for at least part of a semester. Mexican-American students, however, were more likely to report not having received any prevention programming in school. Implications for assessment and prevention ...

The authors report a case of a forty-three-year-old woman with an extensive iatrogenic dissection of the aorta, from the iliac artery to the ascending aorta, not associated with atherosclerosis or previous aortic dissection, as a complication of retrograde arterial catheterization. The authors emphasize the need to take all cautions in performing this procedure to avoid serious complications such as the present one.

Objective.We evaluated the utility of 6 generic and 2 specific risk indices for identifying low bone mineral density (BMD) or osteoporosis in women with rheumatoid arthritis (RA); and their correlation with 10-year probability of fractures as assessed with the World Health Organization fracture risk assessment (FRAX) tool.Methods.Mexican Mestizo women with RA were evaluated in this cross-sectional study using 6 generic indices [Simple Calculated Osteoporosis Risk Estimation (SCORE); Osteoporosis Risk Assessment Instrument (ORAI); Osteoporosis Self-Assessment Tool; Age, Body Size, No Estrogen; Osteoporosis Index of Risk (OSIRIS); and Guidelines of the US National Osteoporosis Foundation], 2 specific indices (Amsterdam and modified Amsterdam), and FRAX. BMD results on dual-energy x-ray absorptiometry (DEXA) at the lumbar spine and femoral neck were considered the “gold standard.” Sensitivity, specificity, and predictive values (PV) of the indices and their correlations with FRAX results were estimated.Results.Among 191 patients, 46 had osteoporosis (24.1%) and 119 had low BMD (62.3%). For predicting osteoporosis, SCORE showed the highest sensitivity (96%), whereas OSIRIS (87%) and ORAI (82%) showed the highest specificities. OSIRIS also had the greatest positive PV (92%). The specific indices had low sensitivity and low specificity (Amsterdam, 50% and 79%, respectively; modified Amsterdam, 56% and 70%). All the indices had a low but significant correlation with FRAX.Conclusion.These findings support the use of some generic indices to identify patients with RA who should undergo DEXA testing. Currently available specific indices did not perform satisfactorily. New specific risk indices for osteoporosis in RA should be developed to increase sensitivity and specificity for predicting osteoporosis.

Background. This study was undertaken to evaluate the technical feasibility and the sensitivity, specificity, and accuracy of remediastinoscopy in restaging N2 bronchogenic carcinoma treated with neoadjuvant chemotherapy. Methods. Patients presenting mediastinal lymph node involvement at mediastinoscopy received three or four cycles of neoadjuvant chemotherapy with mitomycin, iphosphamide, and cisplatin or cisplatin and gemcitabine. If there was no disease progression, these patients underwent remediastinoscopy and, if no residual extracapsular involvement or N3 disease was found, a thoracotomy was then carried out. Results. Twenty-four patients underwent remediastinoscopy. In 12 (50%) remediastinoscopy was positive. The 12 remaining patients were operated on and the tumors resected: 5 pneumonectomies and 7 lobectomies. Lymphadenectomy specimens showed residual disease in mediastinal lymph nodes in 5 patients (pN2) and hilar lymph nodes in 1 patient (pN1). The other 6 patients were free of nodal disease, and 4 of them presented no involvement at lung level either. The sensitivity, specificity, and accuracy of remediastinoscopy were 0.7, 1, and 0.8, respectively. Conclusions. Remediastinoscopy is a technically feasible staging tool with high diagnostic accuracy that is useful in the selection of patients who can be served best by complete resection after neoadjuvant chemotherapy.

Although there have been extraordinary advances in leukemia therapy, there is still a large subset of cases in which complete remission or prolonged leukemia-free survival cannot be achieved. Some of this variability in results is thought to be related to the differences in the effect of chemotherapy drugs on different patients. In many cases, these differences may be associated with the presence of genetic alterations that produce defective drug-metabolizing enzymes, drug transporters or drug targets. One of these is the glutathione-S transferase (GST) gene, which is known to catalyze the conjugation of toxic compounds, such as aliphatic aromatic heterocyclic radicals and epoxides, among others, to glutathione. The enzymes encoded by this gene detoxify polycyclic aromatic hydrocarbons and conjugated isothiocyanates. Objective : Our aim is to evaluate the frequency of deletions in GSTT1 and GSTM1 of the GST gene in Mexican patients with de novo acute leukemia. Methods : Starting in July 2003 and up until now, have included 75 samples from as many patients diagnosed with de novo acute leukemia, regardless of age, sex, or leukemia type. After obtaining informed consent, we drew blood, purified DNA and performed PCR to look for deletions in the GST gene (variants GSTT1 and GSTM1). Results: We found GSTM1 positiveness in 54 samples (72%), of those, 24 (44.5%) were ALL and 30 (55.5%) AML. We had 18 samples (24%) positive for the GSTT1 deletion; of those, 10 (55.5%) were from patients with ALL and 8 (44.4%) from AML patients. Conclusions ; As far as we can tell this is the first report of the frequency of these genetic deletions in Mexican acute leukemia patients. Recently a Mexican group studying the possible association of GSTT1 to lung cancer found that among Mexican controls, the frequency of this deletion was around 4.5%. This result would appear to indicate, as has been done by some other authors, that regardless of the possibility of becoming a prognostic factor, at least some polymorphism of the GST gene could be related to the genesis of this disease.