Successful and failed mini-implants: microbiological evaluation and quantification of bacterial endotoxin

Abstract Objectives Using two groups of mini-implants (successful and failed) the objectives of this in vivo study were: to evaluate the microbial contamination by the checkerboard DNA-DNA hybridization technique and to quantify the bacterial endotoxin by the limulus amebocyte lysate assay. Material and Methods The 15 successful and 10 failed mini-implants (1.6 mm diameter × 7.0 or 9.0 mm long), placed in the maxilla and/or mandible, were obtained from 15 patients undergoing orthodontic treatment. Data were analyzed statistically by the Wilcoxon rank-sum test using the SAS software (a=0.05). Results All 40 microbial species were detected in both groups of mini-implants, with different frequencies. No differences were observed between the groups with respect to microbial complexes (blue, purple, yellow, green, orange, red and other species) and endotoxin quantification (p>0.05). Conclusion Neither microbial contamination nor endotoxin quantification was determinant for the early loss of stability of the mini-implants.

A molecular platform for the diagnosis of multidrug-resistant and pre-extensively drug-resistant tuberculosis based on single nucleotide polymorphism mutations present in Colombian isolates of Mycobacterium tuberculosis

Developing a fast, inexpensive, and specific test that reflects the mutations present in Mycobacterium tuberculosis isolates according to geographic region is the main challenge for drug-resistant tuberculosis (TB) control. The objective of this study was to develop a molecular platform to make a rapid diagnosis of multidrug-resistant (MDR) and extensively drug-resistant TB based on single nucleotide polymorphism (SNP) mutations present in therpoB, katG, inhA,ahpC, and gyrA genes from Colombian M. tuberculosis isolates. The amplification and sequencing of each target gene was performed. Capture oligonucleotides, which were tested before being used with isolates to assess the performance, were designed for wild type and mutated codons, and the platform was standardised based on the reverse hybridisation principle. This method was tested on DNA samples extracted from clinical isolates from 160 Colombian patients who were previously phenotypically and genotypically characterised as having susceptible or MDR M. tuberculosis. For our method, the kappa index of the sequencing results was 0,966, 0,825, 0,766, 0,740, and 0,625 forrpoB, katG, inhA,ahpC, and gyrA, respectively. Sensitivity and specificity were ranked between 90-100% compared with those of phenotypic drug susceptibility testing. Our assay helps to pave the way for implementation locally and for specifically adapted methods that can simultaneously detect drug resistance mutations to first and second-line drugs within a few hours.

Diagnóstico molecular do papilomavírus humano por captura híbrida e reação em cadeia da polimerase / Molecular diagnosis of human papillomavirus in hybrid capture and polymerase chain reaction

A infecção pelo papilomavírus humano (HPV) é extremamente comum e está associada a várias condições clínicas, que variam de infecções assintomáticas a doenças benignas e malignas da mucosa genital, como as verrugas genitais, a neoplasia intraepitelial cervical e o câncer do colo do útero. O objetivo deste estudo foi apresentar as técnicas de biologia molecular por captura híbrida (CH) e reação em cadeia da polimerase (PCR), utilizadas no diagnóstico do HPV e suas aplicações. Métodos mais precisos, quando aplicados em situações especiais, principalmente no caso de divergência entre outros métodos diagnósticos, podem ser aplicados às políticas de saúde pública, visando diminuir a mortalidade causada pelo câncer do colo do útero em consequência do HPV.(AU)

HPV infection is extremely common and is associated with various clinical conditions, ranging from asymptomatic infections to benign and malignant diseases of the genital mucosa, such as genital warts, cervical intraepithelial neoplasia and cervical cancer. The aim of this study was to present the techniques of molecular biology by hybrid capture and PCR, used in the diagnosis of HPV and its applications. More accurate methods when applied in special situations, especially in the case of divergence between other diagnostic methods can be applied to public health policies in order to reduce mortality caused by cervical cancer because of HPV.(AU)

Isolation and characterization of drought-responsive genes from peanut roots by suppression subtractive hybridization

Background Peanut (Arachis hypogaea L.) is an important economic and oilseed crop. Long-term rainless conditions and seasonal droughts can limit peanut yields and were conducive to preharvest aflatoxin contamination. To elucidate the molecular mechanisms by which peanut responds and adapts to water limited conditions, we isolated and characterized several drought-induced genes from peanut roots using a suppression subtractive hybridization (SSH) technique. Results RNA was extracted from peanut roots subjected to a water stress treatment (45% field capacity) and from control plants (75% field capacity), and used to generate an SSH cDNA library. A total of 111 non-redundant sequences were obtained, with 80 unique transcripts showing homology to known genes and 31 clones with no similarity to either hypothetical or known proteins. GO and KEGG analyses of these differentially expressed ESTs indicated that drought-related responses in peanut could mainly be attributed to genes involved in cellular structure and metabolism. In addition, we examined the expression patterns of seven differentially expressed candidate genes using real-time reverse transcription-PCR (qRT-PCR) and confirmed that all were up-regulated in roots in response to drought stress, but to differing extents. Conclusions We successfully constructed an SSH cDNA library in peanut roots and identified several drought-related genes. Our results serve as a foundation for future studies into the elucidation of the drought stress response mechanisms of peanut.

O uso do diagnóstico genético pré-implantacional em pacientes com aborto de repetição: revisão do uso da técnicade array-CGH / The use of preimplantatian genetic diagnasis in patients with recurrent abortion: a review of the technique of array-CGH

Tendo em vista a grande frequência de alterações cromossômicas, seja nos casais com quadros de abortamento de repetição ou nos fetos abortados, uma possibilidade para o tratamento para esses pacientes seria o uso de tratamentos de reprodução assistida, associados ao diagnóstico genético pré-implantacional (PGD) com a técnica de hibridização genética comparativa por array (array-CGH), para a transferência apenas de embriões geneticamente normais. O objetivo desta revisão é avaliar se é possível melhorar o prognóstico gestacional, com redução do número de perdas e o do tempo para conseguir uma gestação saudável, desses casais com aborto de repetição ao usarem o PDG por array-CGH. Foram executadas duas revisões bibliográficas dos últimos 10 anos, a primeira relacionando o uso do PGD nos casos de aborto de repetição e a outra com o uso do array-CGH e PGD. A literatura, apesar de discordante quanto à real eficácia do PGD nos casos de aborto de repetição, tende a se mostrar favorável ao uso dessa técnica, da mesma forma que o método de fluorescence in situ hybridization (Fish) é inferior a array-CGH para o PGD. Dessa forma, apesar de ser uma técnica promissora para casais com AR, o PGD com array-CGH necessita de mais estudos que comprovem sua real eficácia.

Given the high frequency of chromosomal abnormalities, either in couples with recurrent miscarriage or in aborted fetuses, a possibility for treatment for these patients is the use of assisted reproduction treatment, associated with preimplantation genetic diagnosis (PGD) with technique by array comparative genomic hybridization (array-CGH), to transfer only genetically normal embryos. The aim of this review is to assess the feasibility of improving the prognosis ofpregnancy, reducing the number of losses and the time to achieve a healthy pregnancy, for couples with recurrent abortion when using PDC with array-CGH. Two literature reviews were performed for the last 10 years, the first relating the use of PGD and recurrent miscarriage, and the other using the array-CGH and PGD.The literature, although discordant about the real efficacy of PGDin cases of recurrent abortion, tends to show favorableto use this technique, just as the method of array-GGHshows to be better than Fish (fluorescence in-situ hybridization) for PGD. Thus, despire of being a promising technique for couples with RA,the use of PDG with array-GGH needs more study to prove its actual effectiveness.

Identification of chilling-responsive transcripts in peanut (Arachis hypogaea L. )

To isolate differentially expressed peanut genes responsive to chilling, a suppression subtractive hybridization (SSH) cDNA library was constructed for a chilling tolerant peanut cultivar A4 with mRNAs extracted from the seeds imbibed at 2ºC and 15ºC, respectively, for 24 hrs. A total of 466 cDNA clones were sequenced, from which 193 unique transcripts (73 contigs and 120 singlets) were assembled. Of these unique transcripts, 132 (68.4 percent) were significantly similar to the sequences in GenBank non-redundant (nr) protein database, which belonged to diverse functional categories including metabolism, signal transduction, stress response, cell defense and transcriptional regulation. The remaining 61 (31.6 percent) showed no similarity to either hypothetical or known proteins. Six differentially expressed transcripts were further confirmed with real-time quantitative PCR (RT-qPCR).

Colorimetric microwell plate reverse-hybridization assay for Mycobacterium tuberculosis detection

Direct smear examination using Ziehl-Neelsen staining for pulmonary tuberculosis (PTB) diagnosis is inexpensive and easy to use, but has the major limitation of low sensitivity. Rapid molecular methods are becoming more widely available in centralized laboratories, but they depend on timely reporting of results and strict quality assurance obtainable only from costly commercial kits available in high burden nations. This study describes a pre-commercial colorimetric method, Detect-TB, for detecting Mycobacterium tuberculosis DNA in which an oligonucleotide probe is fixed onto wells of microwell plates and hybridized with biotinylated polymerase chain reaction amplification products derived from clinical samples. The probe is capable of hybridising with the IS6110 insertion element and was used to specifically recognise the M. tuberculosis complex. When combined with an improved silica-based DNA extraction method, the sensitivity of the test was 50 colony-forming units of the M. tuberculosis reference strain H37Rv. The results that were in agreement with reference detection methods were observed in 95.2 percent (453/476) of samples included in the analysis. Sensitivity and specificity for 301 induced sputum samples and 175 spontaneous sputum samples were 85 percent and 98 percent, and 94 percent and 100 percent, respectively. This colorimetric method showed similar specificity to that described for commercially available kits and may provide an important contribution for PTB diagnosis.

The ability of the BANA test to detect different levels of P. gingivalis, T. denticola and T. forsythia

The aim of this study was to evaluate the ability of the BANA Test to detect different levels of Porphyromonas gingivalis, Treponema denticola and Tannerella forsythia or their combinations in subgingival samples at the initial diagnosis and after periodontal therapy. Periodontal sites with probing depths between 5-7 mm and clinical attachment level between 5-10 mm, from 53 subjects with chronic periodontitis, were sampled in four periods: initial diagnosis (T0), immediately (T1), 45 (T2) and 60 days (T3) after scaling and root planing. BANA Test and Checkerboard DNA-DNA hybridization identified red complex species in the subgingival biofilm. In all experimental periods, the highest frequencies of score 2 (Checkerboard DNA-DNA hybridization) for P. gingivalis, T. denticola and T. forsythia were observed when strong enzymatic activity (BANA) was present (p < 0.01). The best agreement was observed at initial diagnosis. The BANA Test sensitivity was 95.54 percent (T0), 65.18 percent (T1), 65.22 percent (T2) and 50.26 percent (T3). The specificity values were 12.24 percent (T0), 57.38 percent (T1), 46.27 percent (T2) and 53.48 percent (T3). The BANA Test is more effective for the detection of red complex pathogens when the bacterial levels are high, i.e. in the initial diagnosis of chronic periodontitis.

A acurácia dos testes de Biologia molecular para HPV no diagnóstico de doença residual após tratamento das lesões intraepiteliais escamosas / HPV molecular test accuracy in the diagnosis of residual diseaseafter intraepithelial lesions treatment

As pacientes submetidas ao tratamento de lesões intra-epiteliais de alto grau (LIE-AG) necessitam realizar rigoroso controle, pois apresentam maior risco de lesão residual ou persistente. O presente estudo tem por objetivo avaliar a acurácia da captura híbrida do tipo II, comparada à citologia oncológica no seguimento de pacientes submetidas a tratamento de LIE-AG. Foi realizada revisão sistemática, incluindo-se todos os artigos encontrados até agosto de 2009 e, combinando-se os descritores para cada base de dados específica. Os 260 estudos encontrados foram submetidos a rigorosa avaliação e selecionados a partir de sua qualidade metodológica. Conclui-se que o teste de captura híbrida do tipo II é um método de maior sensibilidade e menor especificidade quando comparado à citologia oncológica, e sua utilização é adequada no seguimento de pacientes com maior risco de lesões intraepiteliais.

Patients submitted to treatment for high squamous intraepithelial lesions (HSIL) need stricter follow-up exams due to a higher risk of persistent or residual lesion. This study aims to evaluate hybrid capture accuracy (type II), compared with Pap smear accuracy,in HSIL patients follow-up. A systematic review was made including all the papers published until August 2009, and combining descriptors for each specific database. The 260 studies were submitted to rigorous evaluation and selected based on their methodological quality. It was concluded that the hybrid capture test type II is a more sensitive method with lower specificity when compared with Pap smear and its use is recomended during the follow-up of patients with increased risk of intraepithelial lesions.

Comparação das técnicas de captura de híbridos e PCR para a detecção de HPV em amostras clínicas / Comparison of hybrid capture and PCR for HPV detection in clinical samples

INTRODUÇÃO E OBJETIVOS: São conhecidos mais de 100 tipos de papilomavírus humano (HPV), dos quais 30 têm sido reportados em infecções anogenitais. A infecção tem importância clínica, pois alguns tipos virais estão associados a lesões que podem progredir para o câncer cervical. Sabe-se que os métodos moleculares são muito importantes para o diagnóstico dessa infecção. O objetivo do estudo é comparar a detecção de HPV de alto risco pelo método de captura híbrida 2 (CH2) com a detecção do vírus pela reação em cadeia da polimerase convencional (PCRc) e em tempo real (PCR-TR). METODOLOGIA: Foram analisadas 56 amostras ectocervicais por CH2 e, após, por PCRc e PCR-TR. RESULTADOS: Ambas, PCRc e PCR-TR, apresentaram alta concordância entre si (95,1 por cento), enquanto a comparação entre as PCRs e a CH2 mostrou concordância razoável entre os resultados (PCRc = 90,2 por cento e PCR-TR = 87,8 por cento). DISCUSSÃO E CONCLUSÃO: A CH é aceita para a detecção do HPV, entretanto pode ser menos sensível em comparação com as técnicas de PCR. A PCR-TR tem a vantagem sobre a PCRc em termos de velocidade, sendo também um pouco mais sensível. Devido à alta sensibilidade e à rapidez, os métodos de PCR poderiam ser usados para a triagem de HPV em amostras ectocervicais.

INTRODUCTION AND OBJECTIVE: More than 100 types of human papillomaviruses (HPV) are known, of which 30 have been reported in anogenital infections. The infection has clinical importance, inasmuch as some viral types are associated with lesions that can progress to cervical cancer. Molecular methods are considered an important tool for the diagnosis of this infection. The objective of this study was to compare the detection of high risk HPV using hybrid capture 2 with HPV detection by conventional and real time PCR. METHODOLOGY: 56 ectocervical samples were analyzed by hybrid capture and after that by conventional and real time PCR. RESULTS: Both PCR and RT-PCR showed a high degree of correlation (95.1 percent), whereas the comparison between PCR and HC2 showed a fair correlation (90.2 percent and 87.8 percent for PCR and RT-PCR, respectively). DISCUSSION AND CONCLUSIONS: HC is widely accepted for the detection of HPV, however, it may lack sensitivity in comparison with PCR techniques. RT-PCR has further advantages over the conventional PCR in terms of speed as well as it is slightly more sensitive. Due to their high sensitivity and fast response, PCR methods could be used as a screening method for HPV detection in ectocervical samples.

Periimplantitis: checkerboard DNA-DNA hybridization for bacterial pathogen identification

A recent innovation in medical field is the use of DNA probes in microbiological diagnosis of the oral cavity. Thus, this study has the objective to present the mainly characteristics of Checkerboard DNA-DNA Hybridization method for bacterial pathogens identification related to periimplantitis, commonly disease found in the oral cavity, as wells as, to show the uses and applications of this technique.

Una innovación reciente en medicina es la utilización de sondas de DNA para diagnóstico microbiológico. Este trabajo tiene como objetivo, presentar las principales características del método Checkerboard DNA-DNA Hybridization para la identificación de bacterias patógenas associadas a periimplantite en la cavidad oral, mostrando las diferentes utilizaciones y aplicaciones de esta técnica.

Identificação e análise de expressão de RNAs intrônicos não codificadores humanos / Identification and expression analysis of human intronic noncoding RNAs

Nesse trabalho, nós mostramos estudos em larga-escala de RNAs não codificadores antisenso que são transcritos em regiões intrônicas de genes humanos. Alguns destes transcritos intrônicos possuem níveis de expressão correlacionados ao grau de diferenciação tumoral de câncer de próstata, apontando para uma relevância biológica destas mensagens em doenças complexas como o câncer. Nós também avaliamos a existência de um mecanismo comum de regulação de transcrição, compartilhado por mRNAs codificadores de proteína e RNAs intrônicos, através de análises de perfís de expressão de uma linhagem tumoral de próstata estimulada por andrógeno. A análise de ESTs e mRNAs depositados em bancos públicos de seqüência revelou mais de 55 mil RNAs Totalmente Intrônicos Não-codificadores (TIN), transcritos dos íntrons de 74% de todos os genes RefSeq únicos. Guiados por esta informação, nós desenhamos uma plataforma de oligonucleotídeos contendo sondas senso e antisenso para cada um de 7.520 transcritos TIN selecionados aleatoriamente, além de sondas para os genes codificadores de proteína correspondentes. Nos identificamos assinaturas intrônicas e exônicas de expressão tecido-específicas em fígado, próstata e rim.Os RNAs TIN antisenso mais altamente expressos eram transcritos de íntrons de genes codificadores de proteína enriquecidos na categoria “Regulação da transcrição...

Determinação da carga viral de DNA de HPV pelo ensaio de captura híbrida e sua associação com achados citológicos / Determination of HPV DNA viral load by hybrid capture assay and its association with cytological findings

OBJECTIVE: To compare the relation between HPV viral load by hybrid capture II test (HCII) and cytological findings. METHODS: Three hundred sixty-two reagent samples to HPV DNA by HCII had their viral loads classified in four categories and correlated to cytological results. RESULTS: Twenty-two samples (6.1 percent) were reagent only to low-risk oncogenic types (group A) and 340 (93.9 percent) were reagent to high-risk oncogenic types (group B). The correlation between viral load for the reagent samples to group A and cytological results showed low-grade squamous intraepithelial lesion (LSIL) predominance (50 percent). Most of this group samples had viral load between 1 to <10RLU/PCA. Of the patients that were reagent to group B 52.1 percent had LSIL cytology and 38.2 percent were negative to intraepithelial lesion and malignancy (NILM) cytology. The patients with LSIL had viral load well distributed with a slight predominance of 100 to < 1,000RLU/PCB category. The samples had viral load between 1 to <10RLU/PCB showed NILM cytology predominance (48.1 percent). High-grade squamous intraepithelial lesions (3.4 percent) were present on the samples with viral load between 100 to <1,000RLU/PCB (p = 0.023). There was a correlation between the median for group B viral load and LSIL/HSIL results. CONCLUSIONS: The quantification of viral load, mainly of high-risk HPV types, may be a useful tool for dealing with patients who have suspicious lesions.

OBJETIVO: Comparar a relação entre a carga viral do HPV por captura híbrida II (HCII) e os achados citológicos. MÉTODOS: Trezentas e sessenta e duas amostras reagentes para DNA de HPV por HCII tiveram suas cargas virais classificadas em quatro categorias e correlacionadas aos resultados citológicos. RESULTADOS: Vinte e duas amostras (6,1 por cento) foram reagentes somente para os tipos de baixo risco oncogênico (grupo A) e 340 (93,9 por cento) foram reagentes para os tipos de alto risco oncogênico (grupo B). A correlação entre carga viral das amostras reagentes para o grupo A e resultados citológicos mostrou predominância (50 por cento) de lesão escamosa intraepitelial de baixo grau (LSIL). A maioria das amostras desse grupo teve carga viral entre 1 e < 10RLU/PCA. Nos pacientes reagentes para o grupo B observamos que 52,1 por cento tiveram citologia LSIL e 38,2 por cento tiveram citologia negativa para lesão intraepitelial e malignidade (NILM). Os pacientes com LSIL tiveram a carga viral bem distribuída, com ligeira predominância da categoria de 100 a < 1.000RLU/PCB. As amostras com carga viral entre 1 e < 10RLU/PCB mostraram predominância de citologia NILM (48.1 por cento). Lesões escamosas de alto grau (3,4 por cento) foram presentes nas amostras com carga viral entre 100 e < 1.000RLU/PCB (p = 0,023). Houve correlação entre a mediana da carga viral para o grupo B e os resultados LSIL/HSIL. CONCLUSÕES: A quantificação da carga viral, principalmente para os tipos de HPV de alto risco oncogênico, pode ser uma ferramenta útil para o acompanhamento de pacientes com lesões suspeitas.

Prevalence of human papillomavirus infection in the genital tract determined by hybrid capture assay

Human Papillomavirus (HPV) infection is the most prevalent sexually-transmitted virus worldwide. It is known to be the etiological agent of cervical cancer and cervical intraepithelial neoplasia (CIN). Consequently, there is strong motivation to evaluate HPV testing in cervical cancer screening. Recently developed, the second generation of the hybrid capture test (HCA II) is a non-radioactive, relatively rapid, hybridization assay, designed to detect 18 HPV types divided into high and low-risk groups. We evaluated 7,314 patients (5,833 women and 1,481 men) for HPV infection by HCA II. Among them, 3,008 (41.1 percent) presented HPV infection: 430 (14.2 percent) had HPV DNA of low risk for cancer, 1,631 (54.2 percent) had high risk HPV types and 947 (31.5 percent) had both types. The prevalence in females was 44.9 percent. The prevalence of HPV DNA in the group for which cytological results were available was slightly higher: 55.3 percent (1007/1824). Significant differences were detected in the frequency of HPV infection of the cervix between normal cases and those with high-grade squamous-intraepithelial lesions (HSIL)(P<0.0001). Among males, the prevalence was 26.2 percent, composed of 9.1 percent in Group A, 9.7 percent in Group B and 7.4 percent with multiple infections. We observed that male prevalence was lower and that low-risk types were more frequent than in females. HPV viral load was significantly greater in SILs than in normal or inflammatory cases (P<0.0001), suggesting an association between high viral load values and risk of SIL. Because of high costs, the HCA II test cannot be recommended for routine mass screening for cervical infection in poor countries. Nevertheless, it was found to be a useful tool, when combined with cytology, discovering high-risk infections in apparently normal tissues and revealing silent infections that may be responsible for the maintenance of HPV in the general population. These findings point...

Frecuencia de la mutación 185delAG en el gen BRCA1 en mujeres chilenas sanas con antecedentes familiares de cáncer de mama / Frequency of the 185delAG mutation in the BRCA1 gene in chilean healthy women with family history of breast cancer

Background: Breast cancer is the most common malignancy among women, and is the second cause of cancer mortality among Chilean women. Female mortality due to breast cancer in Chile has shown a steady increase from 9.5 deaths per 100.000 women in 1985 to 12.8 deaths per 100.000 in 1995. A family history of breast cancer is one of the main risk factors for the development of the disease. BRCA1 and BRCA2 are two major hereditary breast cancer susceptibility genes. Mutations in these genes are associated to inherited breast cancer; 664 predisposing mutations have been described, but in specific populations only some of them, such as 185delAG have been found to be associated with susceptibility to breast cancer. Aim: To establish the frequency of the 185delAG mutation in the BRCA1 gene in Chilean healthy women with a family history of breast cancer. Patients and Methods: The 185delAG mutation was studied by mismatch polymerase chain (PCR) reaction in 382 Chilean healthy women with at least two relatives affected with breast cancer. The PCR products were digested with the restriction enzyme HinfI. Digestion of the normal allele (170 pb fragment) produces a 150 pb fragment; the PCR product for the mutant allele does not contain a site for HinfI and therefore remains as a 170 bp fragment after digestion. Results: One of the 382 healthy women presented the fragment of 170 pb after digestion with HinfI suggesting that she was heterozygous carrier for this mutation. The mutant patient had a mammography without suspicion of cancer. Conclusions: The frequency of the 185delAG mutation in BRCA1 was 0.26 percent (1/382) in Chilean healthy women with a family history of breast cancer

Patología molecular: aplicaciones de la biología molecular en anatomía patológica / Molecular pathology: applications of molecular biological techniques in pathology

The rapid development of molecular biology techniques as well as recent progress in the understanding of genetic and molecular basis of human diseases have had enormous impact in the practice of clinical pathology. Since new diagnostic (molecular) tools are now available, the concept of Molecular Pathology is emerging. Molecular Pathology is defined by the use of molecular biology techniques and the type of specimens that are involved in its practice, basically ARN and ADN, extracted from cytological and tissue specimens. Although most methods used in molecular pathology and their applications are still under investigation and clinical validation they have great potential in several areas of pathological diagnosis, particularly on infectious and neoplastic diseases. Introduction of these techniques in pathology laboratories in our country should significantly enhance the diagnostic and research skills in the field

Detección del virus papiloma humano en entidades clínicas benignas de la cavidad bucal mediante la reacción en cadena de la polimerasa e hibridación molecular / Detection of human papillomavirus in beningn clinical lesions of the oral cavity by means of polymerase chain reaction and molecular hybridization

La reacción en cadena de polimerasa (RCP) y la hibridación molecular se emplearon para detectar y tipificar el virus papiloma humano (VPH) en 40 pacientes con lesiones clínicas y como grupo control en 20 sujetos sanos, on biopsias en mucosa bucal clínicamente normal. La amplificación de ADN de los VPH se realizó utilizando los oligonucleótidos cebadores específicos: MY09 y MY11 y para su tipificación se usó la hibridación en placas que incluye una mezcla de sondas de alto, intermedio y bajo riesgo oncogénico, como los tipos 2, 4, 6, 11, 13, 16, 18 y32. Los resultados demostraron la presencia del genoma viral del VPH en un 55 por ciento (22/40) de las lesiones benignas de la boca y un 10 por ciento (2/20) del grupo control. En las lesiones benignas bucales que fueron positivas por RCP, se observó un 90,9 por ciento (20/22) de VPH del tipo bajo riesgo y un 9.1 por ciento (2/22) de VPH de lato y bajo riesgo oncogénico. En el grupo control se detectó un 5 por ciento (1/20) de VPH de bajo riesgo y un 5 por ciento (1/20) de VPH de alto y bajo riesgo oncogénico. Los resultados demostraron presencia del VPH en lesiones benignas de la cavidad bucal en la población venezolana

Métodos de diagnóstico no convencionales para la tuberculosis / Non conventional diagnostic methods for tuberculosis

En esta revisión se muestran las ventajas y desventajas de algunos de los métodos dirigidos al diagnóstico de la tuberculosis y la identificación de micobacterias

A simple procedure for rehybridization of nuclei analyzed previously by fish

We present a simple procedure for interphase fluorescence in situ rehybridization (FISH). This procedure was used to evaluate fresh prostate tumor from needle biopsy specimens. Digoxigenin-labeled DNA probes were hybridized onto nuclei which had been previously investigated by FISH using biotin-labeled DNA probes. This method makes it possible to reanalyze the same nuclei with different centromeric DNA probes and is useful in cases where a limited number of slides are available.