Biología del virus del papiloma humano y técnicas de diagnóstico

El virus del papiloma humano (VPH) pertenece al grupo de virus con tropismo por los epitelios; infectan predominantemente la piel y las membranas mucosas y producen proliferaciones benignas o papilomas, que bajo ciertas circunstancias pueden experimentar transformación maligna. El VPH es considerado el agente causal más importante del carcinoma del cérvix uterino y el conocimiento de su biología es fundamental para el entendimiento de la carcinogénesis cervical. Existe evidencia epidemiológica y molecular sobre la estrecha relación del VPH en el desarrollo del carcinoma cervical y sus precursores. La infección por el virus del papiloma humano es un importante problema de salud pública en nuestro país, para lo cual se ha identificado a la población con claros factores de riesgo, tales como: inicio temprano de vida sexual activa y múltiples parejas sexuales, hacia quienes se dirigen todos los esfuerzos de prevención y diagnóstico temprano, donde ya se incluyen estudios avanzados y cada vez más sensibles y específicos, con el fin de detectar más oportunamente esta mortal enfermedad

Meningioma con diferenciación rabdoide. Reporte de un caso y revisión de la bibliografía

Introducción: El meningioma constituye 1 a 4% de las neoplasias primarias malignas del SNC en la edad pediátrica y su incidencia se incrementa conforme a la edad. Si bien tiene una predisposición hacia el sexo femenino en edad adulta, la distribución es equitativa en la edad pediátrica. En 1998 Kepes, Perry y colaboradores describieron dos series de meningiomas con zonas de morfología rabdoide y sugirieron el término meningioma rabdoide, que se ha relacionado con un tipo histológico de comportamiento biológico agresivo y mal pronóstico. Caso clínico: Se presenta el caso de un paciente masculino de seis años de edad que ingresó por crisis convulsivas y de ausencia. En la RMN se encontró una tumoración en la región temporo-parietal derecha. Los cortes histológicos revelaron una neoplasia compuesta por células fusiformes, con núcleos alongados y seudoinclusiones, así como zonas con aumento en la celularidad conformadas por células con abundante citoplasma eosinófilo y núcleo desplazado a la periferia. Las tinciones de inmunohistoquímica fueron positivas para EMA en el componente meningotelial y para vimentina en el componente rabdoide. Se diagnosticó meningioma rabdoide. Discusión: El meningioma rabdoide se clasifica como grado III según la OMS. La importancia de identificar estas neoplasias radica en su comportamiento agresivo y en su alta tasa de recurrencia. A pesar de que existen numerosos casos reportados en pacientes adultos, la epidemiologia de estas neoplasias durante la infancia no es del todo clara y los parámetros pronósticos aquí mencionados aún no se estudian del todo en niños

A Fatal Case of Generalized Lysosomal Storage Disease in an Infant.

Gangliosidoses are a heterogeneous group of lysosomal storage diseases with an autosomal recessive trait, which are characterized by the intracellular accumulation of gangliosides in several tissues, mainly in neurons. This condition causes a progressive neurodegenerative disorder with varied clinical presentations. Depending on the severity of the enzymatic defect, gangliosidoses show different rates of clinical progression and organ involvement; poor residual enzyme activity is seen in more aggressive forms (infantile and juvenile subtypes) leading to early death whereas cases with better residual enzyme activity have a late onset in adult life and a milder clinical course. Autopsy findings of a 7 month-old girl with histological and ultrastructural changes consistent with gangliosidosis are presented

Giant lumbar polypoid tumor with bullae on its surface

No abstract availabl

Aspergillus in liquid-based cervicovaginal cytology in a postmenopausal patient: A case report

Abstract. Aspergillus is an opportunistic fungus present in humid environments, whose natural environment is in soil, hay and compost. It is a frequent contaminant in the clinical laboratory. Because of this, the fungus is often inhaled, affecting those with an underlying pulmonary disease or immune deficiency. Fungal genitourinary tract infections are relatively common. A rare Aspergillus spp cervical infection diagnosed via liquid-based cytology is presented in the current study. The 57-year-old woman attended her annual check-up without any relevant medical history. The result of a gynecological examination by Papanicolaou smear was normal and routine liquid-based cytology was performed. The specimen exhibited fungal organisms characterized by septate hyphae branching at acute angles, most consistent with the Aspergillus species. Subsequent cytology demonstrated the same results. Antifungal treatment was initiated and a second post-treatment smear only exhibited atrophy. The cytomorphological features of Aspergillus spp. are discussed in the current study and a brief review of the few reported cases of a primary cervical infection in the literature is provided. In addition, the liquid-based cytology was established as a tool to diagnose the rare Aspergillus infection

Description of Genetic Variants in BRCA Genes in Mexican Patients with Ovarian Cancer: A First Step towards Implementing Personalized Medicine

Abstract Gynecologic cancers are among the leading causes of death worldwide, ovarian cancer being the one with the highest mortality rate. Olaparib is a targeted therapy used in patients presenting mutations in BRCA1 and BRCA2 genes. The aim of this study was to describe BRCA1 and BRCA2 gene variants in Mexican patients with ovarian cancer. Sequencing of BRCA1 and BRCA2 genes from tumors of 50 Mexican patients with ovarian cancer was made in a retrospective, non-randomized, and exploratory study. We found genetic variants in 48 of 50 cases. A total of 76 polymorphic variants were found in BRCA1, of which 50 (66%) had not been previously reported. Furthermore, 104 polymorphic variants were found in BRCA2, of which 63 (60%) had not been reported previously. Of these polymorphisms, 5/76 (6.6%) and 4/104 (3.8%) were classified as pathogenic in BRCA1 and BRCA2, respectively. We have described the genetic variants in BRCA1 and BRCA2 of tumors from Northeast Mexican patients with sporadic ovarian cancers. Our results showed that the use of genetic testing helps recognize patients that carry pathogenic variants which could be beneficial for personalized medicine treatments. Keywords: BRCA; ovarian cancer; personalized therapy; sequencin

Thymidylate synthase gene variants as predictors of clinical response and toxicity to fluoropyrimidine-based chemotherapy for colorectal cancer

Abstract Background: Fluoropyrimidines form the chemotherapy backbone of advanced and metastatic colorectal cancer (CRC). These drugs are frequently associated with toxicity events that result in dose adjustments and even suspension of the treatment. The thymidylate synthase (TYMS) gene is a potential marker of response and toxicity to fluoropyirimidines as this enzyme is the molecular target of these drugs. Our aim was to assess the association between variants of TYMS with response and toxicity to fluoropyrimidines in patients with CRC in independent retrospective and prospective studies. Methods: Variants namely rs45445694, rs183205964, rs2853542 and rs151264360 of TYMS were genotyped in 105 CRC patients and were evaluated to define their association with clinical response and toxicity to fluoropyrimidines. Additionally, the relationship between genotypes and tumor gene expression was analyzed by quantitative polymerase chain reaction. Results: The 2R/2R (rs45445694) was associated with clinical response (p = 0.05, odds ratio (OR) = 3.45) and severe toxicity (p = 0.0014, OR = 5.21, from pooled data). Expression analysis in tumor tissues suggested a correlation between the 2R/2R genotype and low TYMS expression. Conclusions: The allele 2R (rs45445694) predicts severe toxicity and objective response in advanced CRC patients. In addition, the alleles G(rs2853542) and 6bp-(rs151264360) are independent predictors of response failure to chemotherapy. This is the first study made on a Latin American population that points out TYMS gene variants have predictive values for response and toxicity in patients with CRC treated with fluoropyrimidine-based chemotherapy

Molecular cloning of the myo-inositol oxygenase gene from the kidney of baboons

Abstract. The enzyme myo-Inositol oxygenase (MIOX) is also termed ALDRL6. It is a kidney‑specific member of the aldo‑keto reductase family. MIOX catalyzes the first reaction involved in the myo‑inositol metabolism signaling pathway and is fully expressed in mammalian tissues. MIOX catalyzes the oxidative cleavage of myo‑Inositol and its epimer, D-chiro-Inositol to D-glucuronate. The dioxygen-dependent cleavage of the C6 and C1 bond in myo‑Inositol is achieved by utilizing the Fe2+/Fe3+ binuclear iron center of MIOX. This enzyme has also been implicated in the complications of diabetes, including diabetic nephropathy. The MIOX gene was amplified with reverse transcription‑polymerase chain reaction from baboon tissue samples, and the product was cloned and sequenced. MIOX expression in the baboon kidney is described in the present study. The percentages of nucleotide and amino acid similarities between baboons and humans were 95 and 96%, respectively. The MIOX protein of the baboon may be structurally identical to that of humans. Furthermore, the evolutionary changes, which have affected these sequences, have resulted from purifying forces. Key words: animal models, gene expression, kidney, myo-inositol oxygenase, Old World monke