Caracterización clínica y epidemiológica de los pacientes con trastorno por uso de opioides atendidos en una institución de cuarto nivel en la ciudad de Medellín, entre 2017 y 2022 / Clinical and epidemiological characterization of patients with opioid use disorder treated at a fourth level institution in the city of Medellín, between 2017 and 2022

Los analgésicos opioides son una opción importante en el manejo del dolor agudo grave, crónico e intratable, sin embargo, sus efectos euforizantes y gratificantes han motivado a que algunos pacientes continúen su uso una vez resuelta la condición médica inicial, haciendo entonces un uso indebido de opioides (UIO) y con el potencial riesgo de desarrollar un trastorno por uso de opioides (TUO). El objetivo del presente trabajo fue caracterizar clínica y epidemiológicamente a los pacientes con trastorno por uso de opioides atendidos en una institución de cuarto nivel de Medellín. Para ello, se realizó un estudio observacional, descriptivo, transversal de fuente secundaria; se incluyeron 309 registros de pacientes adultos, con diagnóstico CIE-10, trastornos causados por opiáceos. TUO e UIO constituyeron las variables de interés, se procesó la información en Jamovi® versión 2.2 y se analizaron los datos de variables cuantitativas con test de Sahpiro Wilk y análisis bivariado exploratorio de las variables clínicas y sociodemográficas. Resultados: El TUO obtuvo una prevalencia del 39.9% frente al 25,6 % del UIO. De los pacientes con TUO el 50% tenían 35 años o menos, el 57.7% fueron mujeres, 58.7% solteros, y predominaron los niveles de educación secundaria y universitaria. En cuanto al UIO, el 50% fueron menores de 37 años el 54% de sexo femenino, en su mayoría solteros (61.5%), y predominó el nivel de educación secundaria (48.7%). En el 71% de los pacientes con TUO hay antecedentes de enfermedad mental predominando los trastornos del afecto: ansiedad y depresión. El opioide más usado fue tramadol (17.04%), seguido de morfina e hidromorfona. Conclusión: Ante el aumento en la prevalencia de UIO y TUO es necesario nuevas políticas salud pública que permitan ejercer un control más estricto en la formulación, comercialización y administración segura de este tipo de medicamentos.(AU)

Opioids analgesics are an important option in the management of severe acute, chronic, and intractable pain; however, their euphoric and rewarding effects have motivated some patients to continue their use once the initial medical condition has resolved, thus misusing them. these (UIO) and with the potential risk of developing an opioid use disorder (OUD).Objectives: to clinically and epidemiologically characterize patients with opioid use disorder treated at a fourth-level institution in Medellín.Methodology: Observational, descriptive, cross-sectional study of secondary source; 309 records of adult patients with ICD-10, diagnosis caused by opioids agents were included. TUO and IOU were the variables of interest, the information was processed in Jamovi® version 2.2 and the data of quantitative variables were analyzed with the Sahpiro Wilk test and exploratory bivariate analysis of the clinical and sociodemographic variables.Results: The TUO obtained a prevalence of 39.9% compared to 25.6% of the UIO. Of the patients with OT, 50% were 35 years of age or younger, 57.7% were women, 58.7% were single, and secondary and university education levels predominated. Regarding the UIO, 50% were under 37 years of age, 54% female, mostly single (61.5%), and the secondary education level predominated (48.7%).In 71% of patients with OLW there is a history of mental illness, predominantly affective disorders: anxiety and depression. The most used opioid was tramadol (17.04%), followed by morphine and hydromorphone. Conclusion: Given the increase in the prevalence of UIO and OTU, new public health policies are necessary to exercise stricter control in the formulation, marketing and safe administration of this type of medication.(AU)

Moderate protection is induced by a chimeric protein composed of leucine aminopeptidase and cathepsin L1 against Fasciola hepatica challenge in sheep.

Leucine aminopeptidase (FhLAP) and cathepsin L1 (FhCL1) of Fasciola hepatica play a critical role in parasite feeding, migration through host tissue, and immune evasion. These antigens have been tested for immune protection as single components with variable degrees of success. The chimeric-protein approach could improve protection levels against fasciolosis. Previously, we reported the design and construction of a chimeric protein composed of antigenic sequences of FhLAP and FhCL1 of F. hepatica. The goal of the present study was to express and evaluate the immune-protective capacity of this chimeric protein (rFhLAP-CL1) in sheep. Animals were randomly allocated into five groups with five animals in each group. Groups 1, 2 and 3 were immunized twice with 100 µg, 200 µg and 400 µg of rFhLAP-CL1 emulsified with Quil A adjuvant, whereas groups 4 and 5 were the adjuvant control and infection control groups, respectively. The animals were then challenged with 200 metacercariae two weeks after the rFhLAP-CL1 booster. The fluke burden was reduced by 25.5%, 30.7% (p < 0.05) and 46.5% (p < 0.01) in sheep immunized with 100 µg, 200 µg and 400 µg of chimeric protein, respectively, in comparison to the infection control group. There was a reduction of 22.7% (p < 0.05) and 24.4% (p < 0.01) in fecal egg count in groups 2 and 3, respectively, compared to the infection control group. Sheep immunized with chimeric protein produced F. hepatica excretion-secretion product-specific total IgG antibody, which were increased after challenge. Moreover, the levels of rFhLAP-CL1-specific IgG1 and IgG2 isotypes in immunized sheep increased rapidly two weeks after the first immunization and were significantly more elevated than those of the control groups, indicating a mixed Th1/Th2 response. This is a preliminary evaluation of the chimeric protein rFhLAP-CL1 as a possible immunogen against F. hepatica infection in sheep.

Clima organizacional en una institución prestadora de salud de Montería - Córdoba, 2015 / Organizational climate in a health providing Institution of Monteria - Cordoba, 2015

Objetivo. Determinar el clima organizacional de una Institución Prestadora de Salud (IPS), con el fin de establecer estrategias que permitan mejorar el ambiente laboral. Materiales y métodos. Estudio Descriptivo de corte transversal, con enfoque cuantitativo. La población la representaron el total de empleados de la institución, la muestra se aplicó una fórmula estadística que permitió establecer el total de 193 empleados a los que se les aplicó el instrumento de recolección de la información. Se utilizó la técnica encuesta mediante el instrumento cuestionario establecido por la Encuesta sobre el Clima Organizacional basado en los 4 pilares propuestos por la Organización Panamericana de Salud (OPS). Finalmente después de haber recolectado toda la información mediante las encuestas, se procedió a tabularlas mediante una hoja de Excel, y finalmente a realizar las tablas, gráficos y análisis correspondiente, según los objetivos y variables de estudio. De acuerdo a la resolución 08430 de 1993, el estudio fue clasificado sin riesgo, se respetó la confidencialidad, la anonimicidad del encuestado y la institución. Resultados. Se encontraron niveles de satisfacción por encima del 80% en factores como la comunicación, relaciones interpersonales y valores comunicativos y por debajo del 20% en factores como el bienestar social, nivel de capacitación y la compensación y reconocimiento. Conclusiones. Se realizó el diagnóstico del clima organizacional, el cual evidenció fortalezas en la comunicación, el trabajo en equipo, la coperación y liderazgo, por el contrario se obtuvierion oportunidad de mejora en factores como la promoción y el ascenso.

Objective. To determine the organizational climate of a Health care Provider Institution (HPI) to establish some strategies to improve the work environment. Materials and Methods. This was a quantitative, descriptive, and cross-sectional study. The population consisted of all the Institution's employees. A statistical formula was applied to choose the sample. This procedure allowed for the use of the data collection instrument with all the employees. A questionnaire for the survey established for the organizational climate based on the four pillars proposed by Health Pan-American Organization was used. Finally, once all the information was obtained through the survey, the tabulation was done through an Excel spreadsheet, tables and graphics were created, and data analysis completed according to the study variables. In line with Resolution08430,1993, the study was classified as risk-free. Also, the confidentiality and anonymity of both the research participants and the Institution were respected. Results. Levels of satisfaction higher than 80% were founding factors, such as communication, interpersonal relationships, and communicative values. Levels lower than 20% were found in factors, such as wellbeing, level of training as well as compensation and recognition. Conclusions. The diagnosis of the organizational climate revealed communication strengths, team work, cooperation, and leadership. Improvement opportunities in factors, such as promotion and raise were discovered as well.

Active tuberculosis patients have high levels of IgA anti-alpha-crystallin and isocitrate lyase proteins.

SETTING: Mexico City, Mexico. OBJECTIVE: To identify proteins synthetised by Mycobacterium tuberculosis in hypoxic culture, which resemble more closely a granuloma environment than aerobic culture, and to determine if they are recognised by antibodies from patients with active pulmonary tuberculosis (PTB). DESIGN: Soluble extracts from M. tuberculosis H37Rv cultured under aerobic or hypoxic conditions were analysed using two-dimensional polyacrylamide gel electrophoresis, and proteins over-expressed under hypoxia were identified by mass spectrometry. The presence of immunoglobulin (Ig) G, IgA and IgM antibodies against these proteins was determined in the serum of 42 patients with active PTB and 42 healthy controls. RESULTS: We selected three M. tuberculosis H37Rv proteins (alpha-crystallin protein [Acr, Rv2031c], universal stress protein Rv2623 and isocitrate lyase [ICL, RV0467]) that were over-expressed under hypoxia. Titres of anti-Acr and anti-ICL IgA antibodies were higher in patients than in healthy controls, with an area under the receiver operating characteristic curve of 0.71 for anti-ICL IgA antibodies. CONCLUSION: ICL could be used in combination with other M. tuberculosis antigens to improve the sensitivity and specificity of current serological TB diagnostic methods.

A novel antigen-carrier system: the Mycobacterium tuberculosis Acr protein carried by raw starch microparticles.

Microparticles have been used as promising carriers for in vivo vaccine delivery. However, the processes for immobilizing peptides or proteins on microparticles usually require the use of undesirable compounds and complex protocols. In this work, we propose a new immobilization and delivery system with raw starch microparticles and a starch binding domain (SBD) tag fusion protein. The heat shock protein alpha crystallin from Mycobacterium tuberculosis was used as model. The immunogenicity of the system was investigated in BALB/c mice inoculated with purified Acr-SBDtag protein (pAcr-SBDtag) and starch immobilized Acr-SBDtag protein (µAcr-SBDtag) by oral and intranasal routes. We demonstrated mucosal immunization with the µAcr-SBDtag protein induced systemic antibodies that were predominantly immunoglobulin G2a (IgG2a). An analysis of the cytokines from spleen cells and lung homogenates revealed that loaded microparticles induced the secretion of interferon-γ (INF-γ), suggesting an adjuvant effect from the immobilization. The immune responses induced by immobilized protein were primarily affected by the route of administration. These results demonstrate that the system exhibits the necessary characteristics to improve antigen release and presentation to antigen presenting cells (APCs) in the mucosae. Because no extra adjuvants were used, we posit that the system may be suitable for delivery and presentation to the field of subunit vaccine development.

Reolysin is a novel reovirus-based agent that induces endoplasmic reticular stress-mediated apoptosis in pancreatic cancer.

Activating mutation of KRas is a genetic alteration that occurs in the majority of pancreatic tumors and is therefore an ideal therapeutic target. The ability of reoviruses to preferentially replicate and induce cell death in transformed cells that express activated Ras prompted the development of a reovirus-based formulation for cancer therapy called Reolysin. We hypothesized that Reolysin exposure would trigger heavy production of viral products leading to endoplasmic reticular (ER) stress-mediated apoptosis. Here, we report that Reolysin treatment stimulated selective reovirus replication and decreased cell viability in KRas-transformed immortalized human pancreatic duct epithelial cells and pancreatic cancer cell lines. These effects were associated with increased expression of ER stress-related genes, ER swelling, cleavage of caspase-4, and splicing of XBP-1. Treatment with ER stress stimuli including tunicamycin, brefeldin A, and bortezomib (BZ) augmented the anticancer activity of Reolysin. Cotreatment with BZ and Reolysin induced the simultaneous accumulation of ubiquitinated and viral proteins, resulting in enhanced levels of ER stress and apoptosis in both in vitro and in vivo models of pancreatic cancer. Our collective results demonstrate that the abnormal protein accumulation induced by the combination of Reolysin and BZ promotes heightened ER stress and apoptosis in pancreatic cancer cells and provides the rationale for a phase I clinical trial further investigating the safety and efficacy of this novel strategy.

Specificity of the tuberculin skin test is modified by use of a protein cocktail containing ESAT-6 and CFP-10 in cattle naturally infected with Mycobacterium bovis.

The mycobacterial immunodominant ESAT-6 and CFP-10 antigens are strongly recognizable in tuberculosis-infected cattle, and they do not elicit a response in cattle without infection. In addition, they are absent in most environmental mycobacterial species, and therefore, their use can be an alternative to purified protein derivative (PPD) tuberculin in the development of a more specific skin diagnostic test in cattle. The aim of the current study was to assess the potential of an ESAT-6 and CFP-10 (E6-C10) protein cocktail in a skin test format in naturally tuberculosis-infected and paratuberculosis-infected cattle. We also included MPB83 as a third component in one of the protein cocktail preparations. The protein cocktail was tested at different dose concentrations (5, 10, and 15 µg per protein). The best skin response to the E6-C10 protein cocktail was obtained with 10 µg. Subsequently, this concentration was tested in 2 herds with high and low bovine tuberculosis prevalence, the latter with paratuberculosis coinfection. Our data show that the E6-C10 cocktail allows identification of an important proportion of animals that PPDB is not able to recognize, especially in low-prevalence herds. The protein cocktail did not induce reactions in tuberculosis-free cattle or in paratuberculosis-infected cattle. Addition of MPB83 to the protein cocktail did not make any difference in the skin reaction.

Reovirus therapy stimulates endoplasmic reticular stress, NOXA induction, and augments bortezomib-mediated apoptosis in multiple myeloma.

Oncolytic virotherapy with reovirus has demonstrated anti-cancer activity and minimal toxicity in clinical trials, but the mechanisms underlying these effects have not been fully elucidated. Reolysin, a proprietary formulation of reovirus for cancer therapy, stimulated selective viral replication and apoptosis in multiple myeloma (MM) cells. Reolysin-mediated apoptosis was associated with an induction of endoplasmic reticular (ER) stress-related gene expression, swelling of the endoplasmic reticulum, increases in intracellular calcium levels and a strong induction of the Bcl-2 homology 3 (BH3)-only pro-apoptotic protein NOXA. Knockdown of NOXA expression by short hairpin RNA significantly reduced the pro-apoptotic effects of Reolysin. We next showed that co-administration of Reolysin and bortezomib resulted in the dual accumulation of viral and ubiquitinated proteins, which led to enhanced ER stress, NOXA induction and apoptosis. Importantly, the combination of reovirus infection and proteasomal inhibition significantly decreased tumor burden in a xenograft and syngeneic bone disease model of MM without exhibiting adverse side effects. Our study establishes ER stress stimulation and NOXA induction as novel mediators of reovirus-induced apoptosis. Furthermore, reovirus infection can be used as a promising approach to augment the anti-myeloma activity of bortezomib by promoting additional stress to the endoplasmic reticulum of MM cells.

Targeting PIM kinase enhances the activity of sunitinib in renal cell carcinoma.

BACKGROUND: Upregulation of PIM kinase expression has been reported in many malignancies, suggesting that inhibition of PIM kinase activity may be an attractive therapeutic strategy. We hypothesised that inhibition of PIM kinase activity with SGI-1776, a novel small molecule inhibitor of PIM kinase activity, would reduce the viability of renal cell carcinoma (RCC) cells and enhance the activity of sunitinib. METHODS: Immunoblotting, qRT-PCR, and gene expression arrays were carried out to identify genes modulated by SGI-1776 treatment. The anticancer activity of SGI-1776 and sunitinib was determined by viability and apoptosis assays and in tumour xenografts in vivo. RESULTS: Treatment with SGI-1776 led to a decrease in phosphorylated and total c-Myc levels, which resulted in the modulation of c-Myc target genes. SGI-1776 in combination with sunitinib induced a further reduction in c-Myc levels, which was associated with enhanced anticancer activity. siRNA-mediated knockdown of c-Myc demonstrated that its expression has a key role in regulating the sensitivity to the combination of SGI-1776 and sunitinib. Importantly, the combination significantly reduced tumour burden in two RCC xenograft models compared with single-agent therapy and was very well tolerated. CONCLUSION: These data indicate that targeting PIM kinase signalling is a promising treatment strategy for RCC.

Duplicación del peroné, fémur corto congénito, luxación atípica de la cadera y polidactilia central del pie ipsilateral: reporte de caso / Ipsilateral fibular duplication, short congenital femur, atypical congenital hip dislocation, and central polidactilia: case report

El compromiso de varios segmentos de la extremidad es un hallazgo frecuente en los pacientes afectados por deficiencias de las extremidades inferiores. Se describe un caso inédito de un niño de dos años con una inusual combinación de deformidades en su extremidad inferior izquierda: duplicación del peroné, fémur corto congénito, luxación atípica de la cadera y polidactilia central.

Detection of bovine tuberculosis in herds with different disease prevalence and influence of paratuberculosis infection on PPDB and ESAT-6/CFP10 specificity.

Bovine tuberculosis (BTB) is a major animal health problem with zoonotic implications. Current control programs are based on test and slaughter strategies utilizing skin tests with tuberculins as antigens. The low specificity and associated operative difficulties of these tests have driven the search for new antigens and diagnostic assays. In this multicenter study, using herds from Argentina, Mexico and Northern Ireland, we selected skin test positive and negative animals from herds with different prevalence's of BTB and compared tuberculin (PPDB) and ESAT-6+CFP10 as antigens ex vivo. In low prevalence herds, crossreactivity of PPDB was apparent since up to 60% of the PPDB skin test and ex vivo positive animals did not responded to ESAT-6+CFP10 ex vivo. The superior specificity of ESAT-6+CFP10 was confirmed in a Mycobacterium avium sp. paratuberculosis infected herd where several of the animals had strong crossreactivity to PPDB and PPDA but not to ESAT-6+CFP10. In high prevalence herds 85% of the skin test-positive animals, were confirmed ex vivo using either PPDB or ESAT-6+CFP10 as antigen. However, within this group 60% of the skin test negative animals were PPDB and ESAT-6+CFP10 positive ex vivo indicating that the skin test can in some herds yield a significant number of false negative results. In conclusion, the ex vivo test is recommended as an ancillary test to accelerate BTB eradication. In high prevalence herds, PPDB or ESAT-6+CFP10 can be used as antigen whereas in low and medium prevalence herds ESAT-6+CFP10 is the preferred choice.

Optimizing antigen cocktails for detection of Mycobacterium bovis in herds with different prevalences of bovine tuberculosis: ESAT6-CFP10 mixture shows optimal sensitivity and specificity.

Bovine tuberculosis is a major problem in many countries; hence, new and better diagnostic tools are urgently needed. In this work, we have tested ESAT6, CFP10, PE13, PE5, MPB70, TB10.4, and TB27.4 for their potentials as diagnostic markers in field animals from Northern Ireland, Mexico, and Argentina, regions with low, medium, and high prevalences of bovine tuberculosis, respectively. At all three sites, ESAT6 and CFP10 were superior diagnostic antigens, while their combination performed even better at the two sites where the combination was tested, providing the best coverage for the detection of diseased populations. The high sensitivity in the skin test reactor groups, combined with the high specificity in the tuberculosis-free groups, indicated that a diagnosis could correctly be made for 85% of the infected animals, based on their responses to these two antigens. Furthermore, TB10.4, PE13, and PE5 have the potential to supplement ESAT6 and CFP10 in a future five-component diagnostic cocktail.

A marked difference in pathogenesis and immune response induced by different Mycobacterium tuberculosis genotypes.

In the last decade, an unprecedented genetic diversity has been disclosed among Mycobacterium tuberculosis strains found worldwide. However, well-conserved genotypes seem to prevail in areas with high incidence of tuberculosis. As this may be related to selective advantages, such as advanced mechanisms to circumvent [M. bovis Bacille Calmette-Guerin (BCG)-induced] host defence mechanisms, we investigated the influence of strain diversity on the course of experimental disease. Twelve M. tuberculosis strains, representing four major genotype families found worldwide today, and the laboratory strain H37Rv were each used to infect BALB/c mice by direct intratracheal injection. Compared with H37Rv, infections with Beijng strains were characterized by extensive pneumonia, early but ephemeral tumour necrosis factor-alpha (TNF-alpha) and inducible isoform of nitric oxide synthetase (iNOS) expression, and significantly higher earlier mortality. Conversely, Canetti strains induced limited pneumonia, sustained TNF-alpha and iNOS expression in lungs, and almost 100% survival. Strains of the Somali and the Haarlem genotype families displayed less homogeneous, intermediate rates of survival. Previous BCG vaccination protected less effectively against infection with Beijing strains than against the H37Rv strain. In conclusion, genetically different M. tuberculosis strains evoked markedly different immunopathological events. Bacteria with the Beijing genotype, highly prevalent in Asia and the former USSR, elicited a non-protective immune response in mice and were the most virulent. Future immunological research, particularly on candidate vaccines, should include a broad spectrum of M. tuberculosis genotypes rather than a few laboratory strains.

Characterization of the Mycobacterium tuberculosis region containing the mpt83 and mpt70 genes.

Like the products of the genes mpt83 and mpt70, the putative protein encoded by the gene located between these genes was undetectable in Mycobacterium tuberculosis with an antiserum raised against the recombinant protein. The protein showed 100% homology with M. tuberculosis Rv2874 and similarities with CcdA and DipZ proteins involved in cytochrome-c biogenesis in bacteria. Expression analysis by RT-PCR and transcriptional fusions of Rv2874 and their neighbor genes Rv2871, Rv2872, mpt83 and mpt70 with lacZ suggest that these genes are part of an operon and their transcription is driven by promoter regions located 5' upstream of mpt83 and of Rv2874 genes.

Molecular analysis of Mycobacterium tuberculosis phosphate specific transport system in Mycobacterium smegmatis. Characterization of recombinant 38 kDa (PstS-1).

The functionality of the putative Mycobacterium tuberculosis phosphate transport operon was studied by operon- lacZ promoterless fusions in Mycobacterium smegmatis. The expression of the operon genes was evaluated in transformed M. smegmatis growing in medium with low and high phosphate concentration. Although the gene fusions expressed beta-galactosidase in medium with phosphate, a higher activity was detected in bacteria growing in medium with low phosphate. In contrast, alkaline phosphatase activity from M. smegmatis was detected only in bacteria growing in medium with low phosphate. The expression of the operon genes was driven by a promoter located 5' upstream from the start codon of the pstB gene. A second putative internal promoter 5' upstream of the pstS-1 gene was also detected. Furthermore, comparative analysis between the native and recombinant PstS-1 proteins showed that they were very similar. Like the native protein, the recombinant protein was also secreted to the culture medium as a glycosylated band. The results show that M. smegmatis recognized phosphate regulatory signals of the M. tuberculosis phosphate transport operon genes, and open the possibility to study gene phosphate regulation in mycobacteria.

Binding and activation of human plasminogen by Mycobacterium tuberculosis.

The first evidence of the interaction of Mycobacterium tuberculosis with the plasminogen system is herein reported. By FACScan analysis and affinity blotting, lysine-dependent binding of plasminogen to M. tuberculosis was demonstrated. The binding molecules were 30-, 60-, and 66-kDa proteins present in cell wall and soluble protein extracts. The activation of plasminogen, which occurred only in presence of fibrin and was not inhibited by the host serpin, alpha(2)-antiplasmin, was also demonstrated.

Co-stimulatory signals increase the reactivity of gammadelta T cells towards mycobacterial antigens.

Although it has been shown that gammadelta T lymphocytes are able to react with different cell-associated or soluble antigens, the immune repertoire of these cells appears to be skewed to the recognition of mycobacterial antigens. We have studied the number and reactivity of gammadelta T cells towards several mycobacterial antigens in patients with tuberculosis and leprosy, as well as their healthy contacts and control individuals. We found an increased number of Vdelta2+ cells in healthy contacts (PPD+ and lepromin+) and tuberculoid leprosy patients. The gammadelta T cells from lepromatous leprosy showed a decreased response to all antigens tested, but some of these patients exhibited a significant response to the 30-kD glycoprotein of Mycobacterium tuberculosis. Interestingly, the reactivity of gammadelta T cells against mycobacterial antigens was significantly increased by costimulatory signals generated through CD7, LFA-1, CD50 and CD69 in all groups. However, signalling through CD69 did not enhance the responsiveness of gammadelta lymphocytes from lepromatous patients. On the other hand, the in vitro blockade of IL-10 with a specific antibody enhanced the cell proliferation of gammadelta lymphocytes from lepromatous leprosy patients, whereas exogenous IL-10 had an opposite effect in most individuals studied. These results suggest the potential role of different cell membrane receptors in the regulation of gammadelta T cell proliferation induced by mycobacteria, as well as the possible involvement of IL-10 in this phenomenon.

Evaluation of the polymerase chain reaction for the detection of Mycobacterium tuberculosis.

The development of nucleic acid-based technologies has improved the sensitivity, specificity and speed of detection of Mycobacterium tuberculosis in clinical samples. Both commercially available and 'in-house' polymerase chain reaction (PCR) systems are in use, and a significant number of reports compare such systems with more traditional diagnostic tools for tuberculosis. Few studies, however, have focused on the reproducibility of the results when submitting a sample batch to PCR in different laboratories, especially in developing countries. Consequently, PCR results obtained from six laboratories in six different Latin American countries for samples reconstituted with defined amounts of M. tuberculosis cells were evaluated. Each laboratory used specific conditions of sample processing, nucleic acid amplification and amplicon detection. Analysis of results allowed large differences in sensitivity and specificity to be observed. We conclude that in its present setting, in-house PCR cannot be used as a single diagnostic tool for tuberculosis, and that special care needs to be taken upon interpretation of results by inclusion of a proper number of positive and negative controls.