RESUMEN
PURPOSE: BRCA1/2 founder pathogenic variants (PVs) occur in various populations, but data on the mutational spectrum in Africans are limited. We examined BRCA1/2 PVs in breast cancer patients of Ethiopian Jewish (EJ) origin. METHODS: We retrospectively analyzed BRCA1/2 test results and clinical features of EJ breast cancer patients from seven medical institutions. We obtained heterozygote carrier rates in affected individuals from the laboratories of the largest Israeli HMO (Clalit). Population carrier frequency was determined in EJ controls. RESULTS: We identified three recurrent BRCA2 PVs in 11 EJ breast cancer patients (9 females, 2 males): c.7579delG, c.5159C > A, and c.9693delA. Only c.5159C > A was previously reported in Africans. In women, mean age at diagnosis was 35.7y; 8/9 were diagnosed with advanced disease. All tumors were invasive, 4/9 were triple negative. Only 3/11 carriers had relevant family history. Carrier rate in high-risk breast cancer patients was 11% (3/28; 95%CI [2.3%, 28.2%]). Combined carrier rate among controls was 1.8% (5/280; 95%CI [0.6%, 4.1%]). CONCLUSION: EJs harbor 3 recurrent BRCA2 PVs presenting with relatively severe breast cancer morbidity. Combined with the high BRCA2 carrier rate in the EJ population, these findings merit increasing awareness in this community and suggest that a culturally adapted population screening approach may be warranted.
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Proteína BRCA2 , Neoplasias de la Mama Masculina , Neoplasias de la Mama , Judíos , Proteína BRCA2/genética , Neoplasias de la Mama/etnología , Neoplasias de la Mama/genética , Neoplasias de la Mama Masculina/etnología , Neoplasias de la Mama Masculina/genética , Etiopía/epidemiología , Femenino , Efecto Fundador , Predisposición Genética a la Enfermedad , Humanos , Judíos/genética , Masculino , Estudios RetrospectivosRESUMEN
Data on the clinical presentation of constitutional mismatch repair deficiency syndrome (CMMRD) is accumulating. However, as the extraintestinal manifestations are often fatal and occur at early age, data on the systematic evaluation of the gastrointestinal tract is scarce. Here we describe 11 subjects with verified biallelic carriage and who underwent colonoscopy, upper endoscopy and small bowel evaluation. Five subjects were symptomatic and in six subjects the findings were screen detected. Two subjects had colorectal cancer and few adenomatous polyps (19, 20 years), three subjects had polyposis-like phenotype (13, 14, 16 years), four subjects had few adenomatous polyps (8, 12-14 years) and two subjects had no polyps (both at age 6). Of the three subjects in the polyposis-like group, two subjects had already developed high-grade dysplasia or cancer and one subject had atypical juvenile polyps suggesting juvenile polyposis. Three out of the five subjects that underwent repeated exams had significant findings during short interval. The gastrointestinal manifestations of CMMRD are highly dependent upon age of examination and highly variable. The polyps may also resemble juvenile polyposis. Intensive surveillance according to current guidelines is mandatory.
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Pólipos Adenomatosos/genética , Neoplasias Encefálicas/genética , Neoplasias Colorrectales/genética , Mutación , Síndromes Neoplásicos Hereditarios/genética , Adenosina Trifosfatasas/genética , Adolescente , Árabes/genética , Neoplasias Encefálicas/diagnóstico , Niño , Neoplasias Colorrectales/diagnóstico , Enzimas Reparadoras del ADN/genética , Proteínas de Unión al ADN/genética , Endoscopía Gastrointestinal , Femenino , Humanos , Poliposis Intestinal/congénito , Poliposis Intestinal/diagnóstico , Poliposis Intestinal/genética , Judíos/genética , Masculino , Endonucleasa PMS2 de Reparación del Emparejamiento Incorrecto , Proteína 2 Homóloga a MutS/genética , Síndromes Neoplásicos Hereditarios/diagnóstico , Fenotipo , Adulto JovenRESUMEN
Diagnosis of Lynch syndrome (LS) may be complex. Knowledge of mutation spectrum and founder mutations in specific populations facilitates the diagnostic process. Aim of the study is to describe genetic features of LS in the Israeli population and report novel and founder mutations. Patients were studied at high-risk clinics. Diagnostics followed a multi-step process, including tumor testing, gene analysis and testing for founder mutations. LS was defined by positive mutation testing. We diagnosed LS in 242 subjects from 113 families coming from different ethnicities. We identified 54 different mutations; 13 of them are novel. Sixty-seven (59%) families had mutations in MSH2, 20 (18%) in MSH6, 19 (17%) in MLH1 and 7 (6%) in PMS2; 27% of the MSH2 mutations were large deletions. Seven founder mutations were detected in 61/113 (54%) families. Constitutional mismatch repair deficiency (CMMR-D) was identified in five families. Gene distribution in the Israeli population is unique, with relatively high incidence of mutations in MSH2 and MSH6. The mutation spectrum is wide; however, 54% of cases are caused by one of seven founder mutations. CMMR-D occurs in the context of founder mutations and consanguinity. These features should guide the diagnostic process, risk estimation, and genetic counseling.
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Neoplasias Colorrectales Hereditarias sin Poliposis/genética , Adulto , Edad de Inicio , Anciano , Neoplasias Colorrectales Hereditarias sin Poliposis/diagnóstico , Neoplasias Colorrectales Hereditarias sin Poliposis/epidemiología , Reparación de la Incompatibilidad de ADN/genética , Familia , Efecto Fundador , Asesoramiento Genético , Pruebas Genéticas , Humanos , Israel/epidemiología , Persona de Mediana Edad , Mutación , Encuestas y CuestionariosRESUMEN
BACKGROUND AND STUDY AIMS: The Capsule Endoscopy Crohn's Disease Activity Index (CECDAI or Niv score) was devised to measure mucosal disease activity using video capsule endoscopy (VCE). The aim of the current study was to prospectively validate the use of the scoring system in daily practice. METHODS: This was a multicenter, double-blind, prospective, controlled study of VCE videos from 62 consecutive patients with isolated small-bowel Crohn's disease. The CECDAI was designed to evaluate three main parameters of Crohn's disease: inflammation (A), extent of disease (B), and stricture (C), in both the proximal and distal segments of the small bowel. The final score was calculated by adding the two segmental scores: CECDAI =â([A1â×âB1] +âC1) +â([A2â×âB2] +âC2). Each examiner in every site interpreted 6â-â10 videos and calculated the CECDAI. The de-identified CD-ROMs were then coded and sent to the principal investigator for CECDAI calculation. RESULTS: The cecum was reached in 72â% and 86â% of examinations, and proximal small-bowel involvement was found in 56â% and 62â% of the patients, according to the site investigators and principal investigator, respectively. Significant correlation was demonstrated between the calculation of the CECDAI by the individual site investigators and that performed by the principal investigator. Overall correlation between endoscopists from the different study centers was good, with râ=â0.767 (range 0.717â-â0.985; Kappa 0.66; Pâ<â0.001). There was no correlation between the CECDAI and the Crohn's Disease Activity Index or the Inflammatory Bowel Disease Quality of Life Questionnaire or any of their components. CONCLUSION: A new scoring system of mucosal injury in Crohn's disease of the small intestine, the CECDAI, was validated. Its use in controlled trials and/or regular follow-up of these patients is advocated.
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Endoscopía Capsular , Enfermedad de Crohn/patología , Mucosa Intestinal/patología , Índice de Severidad de la Enfermedad , Adulto , Constricción Patológica/patología , Método Doble Ciego , Femenino , Humanos , Intestino Delgado/patología , Masculino , Persona de Mediana Edad , Variaciones Dependientes del Observador , Estudios Prospectivos , Adulto JovenRESUMEN
Lynch syndrome is an inherited cancer predisposition syndrome caused by germline defects in any of the mismatch repair (MMR) genes. Diagnosis of carriers makes precision prevention, early detection, and tailored treatment possible. Herein we report a novel founder deletion of 18,758 bp, mediated by Alu repeats on both sides, detected in Ethiopian Jews. The deletion, which encompasses exon 9-10 of the MSH2 coding sequence, is associated mainly with early-onset MSH2/MSH6-deficient colorectal cancer (CRC) and liposarcoma. Testing of 35 members of 5 seemingly unrelated families of Ethiopian origin yielded 10/21 (48%) carriers, of whom 9 had CRC. Age at first tumor diagnosis ranged from 16 to 89 years. Carriers from the oldest generations were diagnosed after age 45 years (mean 57), and carriers from the younger generation were diagnosed before age 45 years (mean 30). Awareness of this founder deletion is important to improve patient diagnosis, institute surveillance from an early age, and refer patients for genetic counseling addressing the risk of bi-allelic constitutional MMR deficiency syndrome.
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Neoplasias Colorrectales Hereditarias sin Poliposis , Neoplasias Colorrectales , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Neoplasias Colorrectales/genética , Neoplasias Colorrectales Hereditarias sin Poliposis/diagnóstico , Reparación de la Incompatibilidad de ADN/genética , Etiopía , Mutación de Línea Germinal , Humanos , Judíos/genética , Persona de Mediana Edad , Proteína 2 Homóloga a MutS/genética , Adulto JovenRESUMEN
BACKGROUND: The sensitive guaiac faecal occult blood test, Haemoccult SENSA (HOS; Beckman Coulter, Fullerton, CA, USA), is our standard screening test for significant colorectal neoplasia. We evaluated an automatically-developed, quantified human haemoglobin immunochemical faecal test, OC-MICRO (Eiken Chemical Co., Tokyo, Japan), to improve test specificity and so reduce the colonoscopy burden. AIM: To compare guaiac faecal occult blood test and immunochemical faecal test diagnostic efficacy and costs for identifying significant neoplasia. METHODS: Colonoscopies were performed on patients who prepared three daily guaiac faecal occult blood tests with or without immunochemical faecal tests. RESULTS: Total colonoscopy was performed on 151 subjects who prepared both guaiac and immunochemical faecal tests (group 1) and the positive predictive values (PPV) were also compared to those of 162 subjects undergoing colonoscopy for positive guaiac faecal occult blood tests (group 2). In group 1, comparative sensitivity, specificity, and PPVs for significant neoplasia with guaiac faecal occult blood test were 75%, 34%, and 12% (PPV, 18% for group 2) and with immunochemical faecal test were 75%, 94% and 60% (P < 0.01 for specificity). The number of colonoscopy examinations needed to detect a significant neoplasm because of positive faecal occult blood tests was six to eight with HOS and two with OC-MICRO at 21-31% the cost of evaluating a positive guaiac faecal occult blood test. CONCLUSION: An immunochemical faecal test maintains the high sensitivity of guaiac faecal occult blood test, but significantly reduces the colonoscopy burden and screening costs.
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Neoplasias Colorrectales/diagnóstico , Sangre Oculta , Anciano , Colonoscopía/economía , Colonoscopía/estadística & datos numéricos , Femenino , Guayaco , Pruebas Hematológicas/economía , Humanos , Inmunohistoquímica/economía , Masculino , Persona de Mediana Edad , Valor Predictivo de las Pruebas , Sensibilidad y EspecificidadRESUMEN
BACKGROUND: Patients at risk for non-syndromic (Lynch or polyposis) familial colorectal neoplasia undergo colonoscopic surveillance at intervals determined by clinically ascertained protocols. The quantitative immunochemical faecal occult blood test for human haemoglobin is specific and sensitive for significant colorectal neoplasia (cancer or advanced adenomatous polyp). AIM: To determine immunochemical faecal occult blood test efficacy for identifying significant neoplasia in at-risk patients undergoing elective colonoscopy. METHODS: We retrospectively identified consecutive at-risk patients who provided three immunochemical faecal occult blood tests before colonoscopy. Quantitative haemoglobin analysis was performed by the OC-MICRO automated instrument using the 100 ng Hb/mL threshold to determine positivity. RESULTS: In 252 at-risk patients undergoing colonoscopy; five had cancer, 14 an advanced adenoma and 46 a non-advanced adenoma. The immunochemical faecal occult blood test was positive in 31 patients (12.3%). Sensitivity, specificity, positive and negative predictive values for cancer were: 100%, 90%, 16% and 100%, and for all significant neoplasia: 74%, 93%, 45% and 98%. With 88% fewer colonoscopies, all colorectal cancers and 74% of all significant neoplasia would have been identified by this one-time immunochemical faecal occult blood test screening. CONCLUSIONS: A sensitive, non-invasive, interval screening test might be useful to predetermine the need for colonoscopy in this at-risk population and minimize unnecessary examinations. This favourable retrospective evaluation will be extended to a prospective study.
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Colonoscopía/estadística & datos numéricos , Neoplasias Colorrectales/diagnóstico , Hemoglobinas/análisis , Sangre Oculta , Anciano , Neoplasias Colorrectales/genética , Femenino , Humanos , Masculino , Tamizaje Masivo/métodos , Persona de Mediana Edad , Valor Predictivo de las Pruebas , Estudios Retrospectivos , Medición de RiesgoRESUMEN
OBJECTIVE: To compare the effect of enalapril with long-acting nifedipine on orthostatic hypotension in older patients. DESIGN: A prospective, double blinded, cross-over study. SETTING: The outpatient clinic of a university hospital. PARTICIPANTS: Thirty-nine patients aged 65 years or older with systolic blood pressure (SBP) of 140-190 mm Hg and diastolic blood pressure (DBP) of 90-110 mm Hg. INTERVENTION: Enalapril 5-20 mg od or nifedipine 30-90 mg od for 8 weeks, followed by 4 weeks washout and cross-over for a second 8-week period. MEASUREMENTS: Supine and standing 0-, 1-, and 5-minutes blood pressure was recorded before and at the end of each treatment period. RESULTS: At baseline, SBP was 158.8 +/- 8.7 mm Hg, and DBP was 97.1 +/- 5.9 mm Hg. There was a decline in SBP of 6.1 +/- 2.7 mm Hg and 8.4 +/- 4.1 mm Hg after 1 and 5 minutes of standing, respectively. Both agents caused a significant decline in supine blood pressure. Enalapril: supine SBP 158.8 +/- 8.7 to 143 +/- 7.3 mm Hg; supine DBP 97.1 +/- 5.9 to 85.1 +/- 5.1 mm Hg (P = .0001). The drop in SBP after standing for 5 minutes was only 2.4 +/- 1.6 mm Hg with no change in diastolic values. A > or = 10 mm Hg drop in SBP was observed in only three patients, and no patient experienced a decline of 20 mm Hg or more. Nifedipine: supine SBP: 160.3 +/- 9 to 145.3 +/- 8.1 mm Hg; supine DBP: 96.3 +/- 5.7 to 86.3 +/- 5.8 (P = .0001). Nifedipine induced an orthostatic decline in SBP values; there was an 8.7 +/- 4.8 mm Hg difference between supine and 5 minutes standing values (P = .0005) without change in diastolic values. An orthostatic decline in SBP of > or = 10 mm Hg occurred in 13 patients, and there was a drop of > or = 20 mm Hg in six patients. The cross-over of enalapril and nifedipine reproduced the hypotensive effect and reversed the postural effect. (P = .0002 nifedipine vs enalapril) CONCLUSIONS: Enalapril and nifedipine were equipotent in reducing supine blood pressure levels. Enalapril also reduced the number of orthostatic episodes significantly, whereas nifedipine aggravated this phenomenon.
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Inhibidores de la Enzima Convertidora de Angiotensina/efectos adversos , Antihipertensivos/efectos adversos , Bloqueadores de los Canales de Calcio/efectos adversos , Enalapril/efectos adversos , Hipertensión/tratamiento farmacológico , Hipotensión Ortostática/inducido químicamente , Nifedipino/efectos adversos , Inhibidores de la Enzima Convertidora de Angiotensina/uso terapéutico , Antihipertensivos/uso terapéutico , Presión Sanguínea/efectos de los fármacos , Bloqueadores de los Canales de Calcio/uso terapéutico , Estudios Cruzados , Relación Dosis-Respuesta a Droga , Método Doble Ciego , Enalapril/uso terapéutico , Humanos , Hipotensión Ortostática/diagnóstico , Nifedipino/uso terapéutico , Estudios ProspectivosRESUMEN
The role of lipoprotein oxidation in promoting atherosclerosis is gaining recognition as its spectrum of effects is being unveiled. Accelerated atherosclerosis is a major cause of morbidity and mortality in diabetic patients. Treatment with ACE inhibitors reduces oxidation of low-density lipoprotein (LDL-ox) in hypertensive subjects, however, their effect on LDL-ox in diabetic patients is yet obscure. To evaluate the effect of the ACE inhibitor enalapril and the calcium channel blocker nifedipine on LDL oxidation in normotensive type 2 diabetic patients. A randomized single blinded cross-over study was conducted on 24 nonobese, metabolically stable, normotensive patients with type 2 diabetes who were randomly allocated to receive either enalapril, 10 mg/day, or nifedipine, 30 mg/day, for 4 weeks followed by a 2-week washout period. They were then crossed over to a 4-week course with the alternate drug. The oxidation of LDL was evaluated by three methods: dialdehyde analysis using the thiobarbituric acid reactive substances assay with and without the addition of CuSO(4) as well as determination of conjugated dienes in the LDL lipid extract. The propensity of the serum to oxidize LDL was reduced by enalapril by 17-28% depending on the laboratory method used (P=0.0001). Treatment with nifedipine resulted in a rise in LDL-ox of 7-11% as compared to baseline (P<0.05). The difference between the effects of enalapril and nifedipine was statistically significant with all three laboratory methods used (P=0.0001). Both drugs were equally effective in reducing systolic and diastolic blood pressure without affecting HbA(1c) levels and lipid profile. The albumin excretion rate was significantly reduced during treatment with enalapril returning to baseline levels during the washout period and the nifedipine treatment course. Our findings suggest that oxidation of LDL is attenuated by ACE inhibition and augmented by some calcium channel blockers. This observation may contribute insight into the underlying mechanism of the therapeutic effects of ACE inhibition in diabetic patients.
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Diabetes Mellitus Tipo 2/sangre , Enalapril/farmacología , Lipoproteínas LDL/sangre , Lipoproteínas LDL/efectos de los fármacos , Nifedipino/farmacología , Adulto , Anciano , Inhibidores de la Enzima Convertidora de Angiotensina/farmacología , Presión Sanguínea , Bloqueadores de los Canales de Calcio/farmacología , Estudios Cruzados , Diabetes Mellitus Tipo 2/fisiopatología , Femenino , Humanos , Peroxidación de Lípido/efectos de los fármacos , Masculino , Malondialdehído/análisis , Persona de Mediana Edad , Método Simple Ciego , Sustancias Reactivas al Ácido Tiobarbitúrico/análisisRESUMEN
OBJECTIVE: To examine the validity of the time honored threshold value for microalbuminuria of 30 mg/24 h, by analyzing an 8-year follow-up data of 599 patients with diabetes mellitus type 2, normal blood pressure and base-line albumin excretion rate (AER) =30 mg/24 h. PATIENTS: The patients were allocated to three groups according to the baseline values of AER. Group I: 0-10 mg/24 h; Group II: 10.1-20 mg/24 h; Group III: 20.1-30 mg/24 h. RESULTS: Progression to microalbuminuria during follow-up occurred in 25.3, 47.3 and 85.3% of the patients in Group I, II and III, respectively. Compared to Group I, the risk to progress to microalbuminuria was 2. 34 (95% CI 1.32-4.43, P=0.029) in patients of Group II and 12.36 (95% CI 8.9-16.5, P=0.0001) in Group III. The average annual decline in glomerular filtration rate (GFR) was 1.19, 1.64 and 2.52 ml/min per year, respectively in the three groups. The correlation between baseline AER values and subsequent decline in GFR was exponential without a clear threshold value. Compared to Group I, the odds ratio for any cardiovascular end point (e.g. death, non-fatal myocardial infarction etc.) was 1.9 (95% CI 0.8-2.5, P=0.22) for patients of Group II and 9.8 (95% CI 6.7-12.3, P=0.001) for Group III. CONCLUSIONS: The present study shows that patients with baseline AER values of 20.1-30 mg/24 h show an accelerated decline in GFR and significantly higher risk for cardiovascular events than patients with AER values below 20 mg/24 h. Though AER is obviously a continuous variable, the arbitrary threshold value for screening and for preventive strategies should probably be set at 20 rather than at 30 mg/24 h.
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Albuminuria , Diabetes Mellitus Tipo 2/fisiopatología , Diabetes Mellitus Tipo 2/orina , Presión Sanguínea , Enfermedades Cardiovasculares/epidemiología , Diabetes Mellitus Tipo 2/mortalidad , Femenino , Estudios de Seguimiento , Tasa de Filtración Glomerular , Humanos , Masculino , Persona de Mediana Edad , Infarto del Miocardio/epidemiología , Oportunidad Relativa , Valor Predictivo de las Pruebas , Estudios Prospectivos , Reproducibilidad de los Resultados , Factores de Riesgo , Sensibilidad y Especificidad , Tasa de Supervivencia , Factores de TiempoRESUMEN
Sister-chromatid exchange (SCE) was measured in peripheral lymphocytes of 104 greenhouse farmers exposed to pesticides and 44 unexposed workers. The results of SCEs are expressed in two variables: (a) mean number of SCEs per chromosome and, (b) proportion of high frequency cells (cells with more than eight SCEs). A high correlation was found between these two variables. The adjusted means of both SCEs variables were significantly higher among the farmers compared with the unexposed group (P < 0.01). Adjustment was made for smoking, age, education, and origin. The adjusted means of both SCE variables, were significantly elevated (P < 0.05) among the farmers who prepared and applied more than 70% of the pesticides by themselves compared with those who prepared and applied less than 70% of the pesticides by themselves. Both SCEs variables were also significantly elevated (P < 0.05) among farmers who were involved in more than 7.4 sprays per year compared with those with 7.4 or less sprays per year (P < 0.05). We found a tendency towards elevation of the two variables of SCEs among those who did not use protective measures while preparing the pesticides. Evaluation of the influence of years of exposure on the frequency of SCEs showed that the two variables of SCEs were higher among those farmers who were exposed to pesticides for more than 21 years than among those with less than 21 years of exposure. The variables that had the most influence on the elevation of SCEs were self-preparation of the pesticide mixtures and the number of sprayings per year. Because the farmers used a mixture of almost 24 different chemical classes it was impossible to attribute exposure to a specific pesticide or group of pesticides to single farmers. Our finding of a significant increase of SCEs frequency in peripheral lymphocytes in greenhouse farmers indicates a potential cytogenetic hazard due to pesticides exposure.
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Enfermedades de los Trabajadores Agrícolas/genética , Exposición Profesional , Plaguicidas/envenenamiento , Intercambio de Cromátides Hermanas , Adulto , Estudios de Cohortes , Humanos , Persona de Mediana Edad , Estudios RetrospectivosRESUMEN
We conducted a cross-sectional study to determine whether occupational exposure to low levels of ethylene oxide can cause hematological abnormalities. Blood samples were collected from a group of 47 hospital workers who were exposed to ethylene oxide during a mean period of 6.6 years (standard error, 1.1). Ethylene oxide range levels measured were < 0.01 to 0.06 ppm. The control group, individually matched by age, sex, and smoking habits, consisted of 88 workers from the administrative sector. We found significant differences between the exposed and the control group in the frequency of workers with white blood cells lower than the normal range. Although there was no significant difference in the absolute mean number of the total white blood cells, we found an elevation in the absolute mean number of monocytes and eosinophils (P < 0.01) and a decrease (P < 0.01) in the absolute mean number of lymphocytes in the exposed group compared with the control group. We also found an elevation (P < 0.01) in the percentage of hematocrit and the mean absolute number of the red blood cells, and a decrease (P < 0.01) in the mean absolute number of platelets, in the exposed group compared with the control group. The mean absolute number of eosinophils, red blood cells, and percentage of hematocrit was significantly higher, and the mean absolute number of lymphocytes and platelets was significantly lower, in the subgroups with a higher cumulative dose of exposure. A positive dose-response was found between cumulative dose exposure and the absolute mean number of eosinophils. In view of our findings, we suggest that the use of complete blood cells with differential in routine medical surveillance and for early detection of hygiene problems should be reexamined with special attention to the eosinophils count.
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Desinfectantes/efectos adversos , Monitoreo del Ambiente/métodos , Óxido de Etileno/efectos adversos , Enfermedades Hematológicas/inducido químicamente , Enfermedades Hematológicas/epidemiología , Enfermedades Profesionales/inducido químicamente , Adulto , Estudios de Casos y Controles , Estudios Transversales , Monitoreo Epidemiológico , Femenino , Enfermedades Hematológicas/diagnóstico , Humanos , Israel/epidemiología , Modelos Lineales , Masculino , Persona de Mediana Edad , Personal de Hospital , Prevalencia , Valores de Referencia , Medición de Riesgo , Factores de TiempoRESUMEN
GeS2-CdSe superlattices and composite films are prepared by consecutive thermal evaporation of CdSe and GeS2 in vacuum. CdSe layer thickness varies between 1 and 10 nm, while the thickness of GeS2 layers is either equal (in superlattices) to or 20 times greater (in composite films) than that of CdSe layers. Standard spectral photocurrent measurements and various constant photocurrent methods are used to study optical absorption of all samples. An overall blueshift is observed with decreasing CdSe layer thickness of superlattices. This shift is related to a size-induced increase of the optical band gap of CdSe due to one-dimensional carrier confinement in the continuous nanocrystalline CdSe layers. A number of features are observed in the absorption spectra of composite films containing CdSe nanocrystals with average radii of approximately 2.5 and approximately 3.3 nm. They are discussed in terms of three-dimensional carrier confinement and are considered a manifestation of excited electron states in CdSe nanocrystals embedded in GeS2 thin film matrix. In addition to these discrete features, the exponential dependence of the optical absorption (Urbach) edge indicates a distribution of "valence band" tail states associated with disorder. Transient photoconductivity measurements made on similarly prepared SiOx-CdSe superlattices exhibit a rapid fall in photocurrent by a power law decay over several orders of magnitude of time, which is consistent with multi-pletrapping transport via an extensive distribution of deep defects.
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Compuestos de Cadmio/química , Compuestos de Cadmio/efectos de la radiación , Cristalización/métodos , Nanotecnología/métodos , Sulfuros/química , Sulfuros/efectos de la radiación , Conductividad Eléctrica , Germanio/química , Luz , Ensayo de Materiales , Fotoquímica/métodos , Control de Calidad , Reproducibilidad de los Resultados , Semiconductores , Sensibilidad y Especificidad , Silicio/química , Dióxido de Silicio/química , EspectrofotometríaRESUMEN
BACKGROUND: Common reasons for elective screening and surveillance colonoscopy, at predetermined intervals, are family or personal history of colorectal cancer (CRC) or advanced adenoma (AAP). Quantified, human haemoglobin (Hb)-specific, immunochemical faecal occult blood tests (I-FOBT) detect bleeding. AIM: To determine I-FOBT sensitivity for CRC or AAP before elective colonoscopy in patients at high-risk of cancer or advanced adenoma. METHODS: Prospective double-blind study of 1000 ambulatory asymptomatic high-risk patients (555 family history of CRC, 445 surveillance for past neoplasm), who prepared three I-FOBTs before elective colonoscopy. I-FOBTs quantified as ngHb/mL of buffer by OC-MICRO instrument and results >or=50 ngHb/mL considered positive. RESULTS: At colonoscopy, eight patients had CRC, 64 others had AAP. Sensitivity for CRC and/or AAP was the highest, 65.3% (95% CI 54.3, 76.3), when any of the three I-FOBTs was >or=50 ngHb (15.4%), with specificity of 87.5% (95% CI 86.4, 90.5) identifying all CRCs and 62% of AAPs. CONCLUSIONS: All cancers or an AAP were detected every third I-FOBT-positive colonoscopy (47/154), so colonoscopy was potentially not needed at this time in 84.6% (846 patients). I-FOBT screening might provide effective supervision of high-risk patients, delaying unnecessary elective colonoscopies. This favourable evaluation needs confirmation and cost-benefit study by risk-group.
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Adenoma/diagnóstico , Colonoscopía/estadística & datos numéricos , Neoplasias Colorrectales/diagnóstico , Hemoglobinas/análisis , Sangre Oculta , Neoplasias Colorrectales/genética , Susceptibilidad a Enfermedades , Métodos Epidemiológicos , Femenino , Humanos , Inmunohistoquímica/métodos , Masculino , Tamizaje Masivo/métodos , Persona de Mediana EdadAsunto(s)
Bleomicina/efectos adversos , Neumonía/inducido químicamente , Neumonía/diagnóstico , Enfermedad Aguda , Adulto , Bleomicina/uso terapéutico , Dexametasona/administración & dosificación , Diagnóstico Diferencial , Relación Dosis-Respuesta a Droga , Estudios de Seguimiento , Germinoma/diagnóstico , Germinoma/tratamiento farmacológico , Humanos , Neoplasias Pulmonares/diagnóstico , Neoplasias Pulmonares/tratamiento farmacológico , Masculino , Terapia por Inhalación de Oxígeno , Neumonía/tratamiento farmacológico , Neumonía Neumocócica/diagnóstico , Medición de Riesgo , Tomografía Computarizada por Rayos X , Resultado del TratamientoRESUMEN
BACKGROUND: The guaiac faecal occult blood test (G-FOBT), HemoccultSENSA, is sensitive for significant neoplasms [colorectal cancer (CRC), advanced adenomatous polyps (AAP)], but faulted by non-specificity for human haemoglobin (Hb). Quantified, Hb- specific, immunochemical faecal occult blood tests (I-FOBT) are now used. AIMS: To (i) compare I-FOBT and G-FOBT efficacy in identifying significant neoplasms and colonoscopy needs for positive tests and (ii) examine number of I-FOBTs needed and test threshold to use for equivalent or better sensitivity than G-FOBT and fewest colonoscopies for positive tests. METHODS: Three daily G-FOBTs and I-FOBTs were collected and analysed in 330 patients scheduled for colonoscopy. RESULTS: Colonoscopy found significant neoplasms in 32 patients, 6 CRC, 26 AAP. G-FOBT, sensitivity and specificity were 53.1% (17 neoplasms) and 59.4%, resulting in 8.1 colonoscopies/neoplasm. One I-FOBT having >or=50 ngHb/mL of buffer provided equivalent sensitivity but 94.0% specificity, resulting in 2.1 colonoscopies/neoplasm. By analysing the higher of two I-FOBTs at 50 ngHb/mL threshold, sensitivity increased to 68.8% (22 neoplasms, P = 0.063), specificity fell to 91.9% (P < 0.001), but still required 2.1 colonoscopies/neoplasm. CONCLUSIONS: In this population, quantified I-FOBT had significantly better specificity than G-FOBT for significant neoplasms, reducing the number of colonoscopies needed/neoplasm detected. Results depend on the number of I-FOBTs performed and the chosen development threshold.
Asunto(s)
Pólipos del Colon/diagnóstico , Colonoscopía/métodos , Neoplasias Colorrectales/diagnóstico , Sangre Oculta , Anciano , Pólipos del Colon/química , Neoplasias Colorrectales/química , Estudios de Evaluación como Asunto , Femenino , Guayaco , Humanos , Inmunohistoquímica , Indicadores y Reactivos , Masculino , Persona de Mediana Edad , Estadificación de Neoplasias , Sensibilidad y EspecificidadRESUMEN
BACKGROUND: Faecal occult blood tests (FOBT) are faulted by low sensitivity for advanced adenomatous polyps (AAP). Quantified, immunochemical, haemoglobin (Hb)-specific immunochemical FOBT (I-FOBT) measurements are now used for colorectal screening. AIMS: To correlate adenoma characteristics to amount of faecal Hb lost and to evaluate sensitivity and specificity for AAP by faecal Hb development threshold used and number of I-FOBTs collected. METHODS: Three daily I-FOBTs were collected and analysed in 1221 patients scheduled for colonoscopy. Faecal Hb was analysed as ngHb/mL of buffer and the highest result related to colonoscopy findings. RESULTS: In 1204 patients without cancer, colonoscopy identified adenomas in 294, 99 with AAPs. Adenoma patients had elevated faecal Hb increasing with advanced histology, size, pedunculated shape and multiplicity (P < 0.001 for all). At 50 ngHb/mL threshold, sensitivity and specificity for AAPs were 54.5% (95%CI 44.7, 64.7) and 88.1% (95%CI 86.2, 90.1) for three tests. At higher thresholds, sensitivity decreased, but was significantly higher with more samples collected. Conversely, specificity increased at higher thresholds, but decreased with more samples. CONCLUSIONS: Faecal Hb loss from adenomas is significantly associated with size, number and advanced features. Sensitivity and specificity for AAPs are determined by test threshold chosen and number of samples collected; these determine the number of colonoscopies needed for positive tests.
Asunto(s)
Adenoma/diagnóstico , Pólipos del Colon/diagnóstico , Neoplasias Colorrectales/diagnóstico , Hemoglobinas/análisis , Inmunohistoquímica/métodos , Sangre Oculta , Pólipos Adenomatosos , Anciano , Pólipos del Colon/química , Colonoscopía/métodos , Neoplasias Colorrectales/química , Heces/química , Femenino , Humanos , Masculino , Tamizaje Masivo/métodos , Persona de Mediana Edad , Valor Predictivo de las Pruebas , Sensibilidad y EspecificidadRESUMEN
BACKGROUND: Inflammatory bowel disease (IBD) patients undergo multiple radiological evaluations. AIM: To estimate total and abdominal radiation exposure from diagnostic X-ray investigations in IBD patients and the associated risk factors. METHODS: Patients with Crohn's disease (CD) or ulcerative colitis (UC) treated in the IBD clinic were recruited. Clinical data were extracted from patient files and radiological data were obtained from the central HMO computer data base. RESULTS: A total of 199 CD and 125 UC patients were included. The mean cumulative estimated doses (CED) for CD and UC were 21.1 19.5 and 15.1 20.4 millisieverts (mSv) respectively (P < 0.001). Twenty-three patients (7.1%) had an estimated CED of > or =50 mSv. In multivariate analyses, predictors of increased CED were: surgery (OR 5.68, 95% CI: 2.73-11.8, P < 0.001), CD (OR 2.56, 95% CI: 1.29-5.07, P = 0.007), prednisone use (OR 2.0, 95% CI: 1.11-3.67, P = 0.02), first year of disease (OR 6.4, 95% CI: 1.3-32, P = 0.02) and age in the upper quartile(OR 3.26, 95% CI: 1.68-6.3, P = 0.001). CONCLUSIONS: Diagnosis of CD, IBD-related surgery, prednisone use, first year of diagnosis and age on the upper quartile are independent predictors of increased exposure in IBD patients. Alternative investigations which do not require radiation exposure should be considered for patients at risk for increased radiation exposure.
Asunto(s)
Colitis Ulcerosa/diagnóstico por imagen , Enfermedad de Crohn/diagnóstico por imagen , Diagnóstico por Imagen/efectos adversos , Neoplasias Inducidas por Radiación/etiología , Traumatismos por Radiación/etiología , Adulto , Factores de Edad , Análisis de Varianza , Colitis Ulcerosa/complicaciones , Enfermedad de Crohn/complicaciones , Relación Dosis-Respuesta en la Radiación , Femenino , Humanos , Incidencia , Israel/epidemiología , Masculino , Neoplasias Inducidas por Radiación/epidemiología , Neoplasias Inducidas por Radiación/prevención & control , Traumatismos por Radiación/epidemiología , Radiografía , Factores de RiesgoRESUMEN
Little is known about the effects of immunosuppression on patients with hereditary nonpolyposis colorectal cancer (HNPCC). We describe a kidney transplant recipient with unrecognized Muir-Torre syndrome in whom the administration of a tacrolimus-based regimen led to the eruption of multiple sebaceous tumors. The patient was later found to harbor an MSH2 mutation. Switching to a sirolimus-based regimen resulted in arrest of the disease. When the patient was switched back to tacrolimus, new facial lesions rapidly appeared. Switching again to sirolimus resulted again in halting the appearance of new lesions. This finding is in line with the known antiangiogenic activity of sirolimus and reports on the regression of cutaneous Kaposi's sarcoma in kidney transplant recipients switched from another immunosuppressive regimen to sirolimus. Further studies on the potential use of sirolimus for the treatment of de novo tumors in immunosuppressed kidney transplant recipients with HNPCC are warranted.
Asunto(s)
Adenoma/prevención & control , Neoplasias Colorrectales Hereditarias sin Poliposis/patología , Inmunosupresores/uso terapéutico , Neoplasias de las Glándulas Sebáceas/prevención & control , Sirolimus/uso terapéutico , Tacrolimus/efectos adversos , Adenoma/patología , Progresión de la Enfermedad , Humanos , Terapia de Inmunosupresión/métodos , Inmunosupresores/efectos adversos , Trasplante de Riñón/efectos adversos , Trasplante de Riñón/inmunología , Masculino , Persona de Mediana Edad , Proteína 2 Homóloga a MutS/genética , Mutación/genética , Neoplasias de las Glándulas Sebáceas/patología , Síndrome , Tacrolimus/uso terapéuticoRESUMEN
A psoas abscess-like metastasis of squamous cell carcinoma of uterine cervix was diagnosed in a 50-year-old, HIV-negative woman. While there was complete regression of the primary tumor, the psoas cystic lesion grew in size during chemotherapy, with iliac bone destruction and invasion to the gluteus muscle. A computed tomography-guided bone biopsy was done and histopathologic examination revealed squamous cell carcinoma consistent with the primary lesion. Intratumoral injection of cisplatin and radiotherapy resulted in partial relief of symptoms. This form of aggressive, bone destruction metastasis was hitherto reported only in association with AIDS.