A confirmatory diagnosis of antibodies anti-Trypanosoma cruzi in donors referred by blood banks in Venezuela

To establish the confirmatory diagnosis of Trypanosoma cruzi infection, at least two immunoserological tests (ELISA, Indirect hamaglutination, IH, Complement Fixation Test, CFT) were carried out in 254 donors, from public and private blood banks of Venezuela, during 48 months between 1997-1998 and 2003-2004, referred to the Immunology Section of the Tropical Medicine Institute in Caracas. Antibodies anti-T. cruzi were detected in 129/254 (50,79%) by ELISA-IgG or IH and CFT. The "artificial xenodiagnosis" was positive in 10/118 persons with positive confirmed serology. Of 129 donors found positive by the serological tests, 68 were living in the capital region and 61 in the interior of the country. Likewise 113 were born in the interior of the country, 8 in Caracas and 8 in Colombia. Of them, 12 individuals serologically confirmed declared to have donated blood in a minimum of 4 occasions before diagnosis. The present study emphasizes the importance of detection of antibodies against T. cruzi in the integral evaluation of blood donors, since many of them with antibodies anti-T. cruzi, have donated blood several times previous to diagnosis.     

A Paradox: α-Klotho Levels and Smoking Intensity

Reports regarding smoking differences in α-klotho expression have provided conflicting results. In the current study we focused on the influence of smoking intensity to serum levels of the aging molecule α-klotho in healthy smokers. 40 middle aged healthy smokers without airway obstruction or restriction were selected for the analysis. Serum levels of soluble α-klotho were significantly higher in heavy smokers (P < 0.001). These results are in agreement with the possibility that α-klotho acts as anti-inflammatory molecule and strengthen the hypothesis that an increase of serum levels of α-klotho might be a compensatory response to smoking stress in healthy population.     

Resultados de un programa de detección precoz de la hipoacusia neonatal

Introduction and objectivesNeonatal hearing loss is a public health problem that meets the requirements for submission to universal screening. Our objective was to analyse the results of the early hearing detection and intervention program implemented at our centre between January 2007 and December 2010.MethodsWe studied 26,717 newborns during the period mentioned, using transient otoacoustic emissions (TOAEs) for the screening. The diagnostic phase was carried out at the hearing loss department.ResultsIn our area, there were 27,935 births between January 2007 and December 2010. The screening was performed on 26,717 children. Of these, 24,173 had positive TOAEs, 1,040 had no TOAEs and 1,504 presented TOAEs in 1 ear with absence of TOAEs in the contralateral ear. Risk factors associated with hearing loss were found in 4,674 infants. In a second phase of the program, TOAEs were given to 5,156 children, of whom 4,626 had positive otoacoustic emissions in both ears, 323 had no TOAEs in 1 ear and 207 failed this second phase. Of all children studied, 3.8% were referred to auditory brainstem response (ABR) testing and 26 children entered the cochlear implant program. The program reached coverage of 95.64%.ConclusionsThe early hearing detection and intervention program at our hospital is suitable for our environment, reaching 95.64% of coverage. We consider the relationship between effectiveness and efficiency to be positive.     

Conjunctival healing after amniotic membrane graft over ischemic sclera

PURPOSE: To present a case of chemical injury associated with calcification and severe conjunctival and scleral ischemia, in which tissue regeneration was achieved using an amniotic membrane graft. METHODS: A 65-year-old man presented to our department 8 weeks after suffering a chemical injury of his left eye with sulfuric acid. There was extensive calcification of the cornea and conjunctiva, associated with severe ischemia of the adjacent sclera. After resection of the calcified tissue and nonviable tissue, amniotic membrane was grafted to cover the extensive zone of scleral ischemia. RESULTS: In the weeks following grafting, slow epithelialization and revascularization was observed over the amniotic membrane, stemming from the surrounding healthy conjunctiva. CONCLUSION: Although the presence of ischemia at the base of the graft has been considered a contraindication for amniotic membrane transplantation, this case demonstrates that, provided that the surrounding tissue is not affected, a graft may be useful. In such cases an amniotic membrane graft could be attempted before other alternatives, such as conjuntival or oral mucosal autografts.     

M34 actin regulatory protein is a sensitive diagnostic marker for early- and late-stage mammary carcinomas.

PURPOSE: At present, there is no available molecular marker that reliably detects the earliest stages of epithelial transformation in the majority of patients affected with incipient breast carcinoma. Here we introduce M34 protein, a mammalian actin filament regulatory protein, as a highly sensitive and easily detected positive cellular marker for both early and late stages of breast carcinoma. EXPERIMENTAL DESIGN: In this study, 24 human lactation duct neoplasms from postmenopausal women, including fibroadenoma, ductal carcinoma in situ, intraductal lobular papilloma, and metastatic adenocarcinoma, were analyzed for the presence of M34 protein by histochemical staining of paraffin and fresh-frozen sections. RESULTS: All 24 neoplasias tested positive for M34, whereas none of the 4 normal breast tissues stained for the protein. M34 identification was strongly positive for transformed epithelium in all tumor types tested. Twelve precancerous lesions of fibroadenoma (n = 4), intraductal papilloma (n = 4), and incipient ductal carcinoma in situ (n = 4) all showed high levels of M34 staining, suggesting that precancerous tumors, as well as the earliest stages of mammary carcinoma, can be sensitively detected. Furthermore, anti-M34 antibody selectively stained all 12 advanced-stage metastatic adenocarcinoma cell masses and micrometastases in axillary lymph nodes tested. Single-cell micrometastases embedded in connective tissue or lymph node parenchyma could be clearly resolved by M34 with horseradish peroxidase staining. Lymphocytes, normal ductal endothelium, and vascular endothelial cells were M34-negative, as were muscle, nerve, and adipose tissues. Low-level M34 staining was detected in connective tissue fibroblasts, macrophages, and neutrophils. CONCLUSIONS: To our knowledge, no previously reported markers have shown high sensitivity of detection for both the earliest and most advanced stages of breast carcinoma. Consequently, M34 appears uniquely suited for diagnosis of the earliest stages of lactation duct transformation as well as for advanced-stage mammary carcinoma metastases in surgical margins and axillary lymph nodes.     

Self-assembly of 6-thioguanine and 6-thioguanosine monolayers on the mercury electrode: effects of oxygen and applied potential

The formation of self-assembled monolayers (SAMs) of 6-thioguanine and 6-thioguanosine on mercury from deaerated and air-saturated aqueous solutions has been studied. The self-assembly process was investigated using chronoamperometry, cyclic voltammetry and open circuit potential (ocp) measurements. The presence of dissolved oxygen is a necessary condition for the formation of full SAMs on a hanging mercury drop electrode (HMDE) at ocp. In the absence of oxygen, the formation of such SAMs requires application of an appropriate potential to the HMDE during a certain period of time. The effects of oxygen and applied potential are explained on the basis of the charge-transfer reaction involved in the self-assembly process.