Asymmetric palatine tonsil in a pediatric patient: Is it always a malignant neoplasm?

Background: A relatively frequent clinical finding in children is an asymmetric tonsil, which can have multiple etiological possibilities, including a malignant disease. The clinical finding of tonsillar asymmetry is found in approximately 2% of the pediatric population. The incidence of malignancy in the tonsils is low, estimated as 2.

MicroRNA Profiling in Wilms Tumor: Identification of Potential Biomarkers.

Wilms tumor (WT) is the most frequently diagnosed malignant renal tumor in children. With current treatments, ~90% of children diagnosed with WT survive and generally present with tumors characterized by favorable histology (FHWT), whereas prognosis is poor for the remaining 10% of cases where the tumors are characterized by cellular diffuse anaplasia (DAWT). Relatively few studies have investigated microRNA-related epigenetic regulation and its relationship with altered gene expression in WT.

Discovery of a transcriptomic core of genes shared in 8 primary retinoblastoma with a novel detection score analysis.

Purpose: Expression microarrays are powerful technology that allows large-scale analysis of RNA profiles in a tissue; these platforms include underexploited detection scores outputs. We developed an algorithm using the detection score, to generate a detection profile of shared elements in retinoblastoma as well as to determine its transcriptomic size and structure.

Methods: We analyzed eight briefly cultured primary retinoblastomas with the Human transcriptome array 2.

Circulating miRNome detection analysis reveals 537 miRNAS in plasma, 625 in extracellular vesicles and a discriminant plasma signature of 19 miRNAs in children with retinoblastoma from which 14 are also detected in corresponding primary tumors.

miRNAs regulate post-transcriptional gene expression in metazoans, and thus are involved in many fundamental cellular biological processes. Extracellular miRNAs are also found in most human biofluids including plasma. These circulating miRNAs constitute a long distance inter cellular communication system and are potentially useful biomarkers.

Expression of YY1 in Wilms tumors with favorable histology is a risk factor for adverse outcomes.

Aim: To investigate the role of the transcription factor YY1 in Wilms tumor (WT).

Patients & Methods: We measured YY1 expression using tissue microarray from patients with pediatric renal tumors, mainly WT and evaluated correlations with the predicted clinical evolution. YY1 expression was measured using immunohistochemical and protein expression was determined by digital pathology.

[Pulmonary sequestration associated with congenital pulmonary airway malformation].

Introduction: Congenital pulmonary malformations are a rare cause of neonatal morbidity. Some of them have a common origin, which allows the identification of combined lesions. Its diagnosis can be made prenatally by ultrasound, with the limitation that this study is performed in specialized centers and depends on the expertise of the operator.

Disseminated Tuberculosis and Chronic Mucocutaneous Candidiasis in a Patient with a Gain-of-Function Mutation in Signal Transduction and Activator of Transcription 1.

In humans, recessive loss-of-function mutations in are associated with mycobacterial and viral infections, whereas gain-of-function (GOF) mutations in are associated with a type of primary immunodeficiency related mainly, but not exclusively, to chronic mucocutaneous candidiasis (CMC). We studied and established a molecular diagnosis in a pediatric patient with mycobacterial infections, associated with CMC. The patient, daughter of a non-consanguineous mestizo Mexican family, had axillary adenitis secondary to BCG vaccination and was cured with resection of the abscess at 1-year old.

miRNome landscape analysis reveals a 30 miRNA core in retinoblastoma.

Background: miRNAs exert their effect through a negative regulatory mechanism silencing expression upon hybridizing to their target mRNA, and have a prominent position in the control of many cellular processes including carcinogenesis. Previous miRNA studies on retinoblastoma (Rb) have been limited to specific miRNAs reported in other tumors or to medium density arrays. Here we report expression analysis of the whole miRNome on 12 retinoblastoma tumor samples using a high throughput microarray platform including 2578 mature miRNAs.

[Sarcoidosis in childhood. A rare systemic disease].

Background: Sarcoidosis is a systemic disease of unknown etiology that rarely occurs in children. It usually affects the lungs, however, it may involve various organs. It occasionally affects the general condition, and causes fever, hepatomegaly and splenomegaly.

[Incontinentia pigmenti with defect in cellular immunity].

Background: Incontinentia pigmenti is a rare, X-linked genetic disease and affects all ectoderm-derived tissues such as skin, appendages, eyes, teeth and central nervous system as well as disorders of varying degree of cellular immunity characterized by decreasing melanin in the epidermis and increase in the dermis. When the condition occurs in males, it is lethal.

Case Report: We present the case of a 2-month-old infant with severe incontinentia pigmenti confirmed by histological examination of skin biopsy.

Detection of common chromosomal translocations in small round blue cell pediatric tumors.

Background And Aims: Recurrent and specific chromosomal translocations have been described in four pediatric sarcomas belonging to the small round blue cell (SRBC) group of tumors. Identification of mRNA chimeras using RT-PCR discriminates among alveolar rhabdomyosarcoma (ARMS), Ewing's sarcoma (ES/pPNET), synovial sarcoma (SS) and desmoplastic small round cell tumor (DSRCT); however, frequencies of these translocations are variable. We present a retrospective study comparing histological examination and occurrence of major chromosomal translocations to validate the diagnosis and to assess the frequency of these molecular markers in a group of 92 small round blue cell (SRBC) tumor samples from Hospital Infantil de Mexico.

Epigenetic modifications in cell lines of human astrocytoma differentially regulate expression of apoptotic genes.

Objects: Epigenetic alterations, known as epimutations, act by deregulating gene expression. These epimutations are reversible through the action of chromatin modifiers such as DNA methylation (DNA-met) and histone deacetylases (HDAC) inhibitors. The present study evaluated the effect of 5-azacitidine (5-aza) and sodium butyrate (NaBu) as inhibitors of DNA-met and HDAC, respectively, in the expression of genes involved in apoptosis.

Toxic effects induced by curcumin in human astrocytoma cell lines.

Objective: The objective of this study was to describe the toxicity induced by curcumin in human astrocytoma cell lines.

Methods: The effects induced by curcumin, at 100 µM for 24 h, were evaluated in four astrocytoma cell lines using crystal violet assay and through the evaluation of morphological and ultrastructural changes by electron microscopy. Also, the results of vital staining with acridine orange and propidium iodide for acidic vesicles and apoptotic bodies were analyzed and the expression of the Beclin1 gene was assessed by RT-PCR.

Expression of histone acetylases p300 and PCAF in pediatric astrocytomas.

Objects: The protein 300 (p300) and p300/CBP-binding protein-associated factor (PCAF) are enzymes with histone acetyltransferase (HAT) activity, a function that can become deregulated in different tumors and affect biological responses.

Methods: Due to the lack of information on the deregulation of these HATs in pediatric tumors, this study evaluated the expression of both the mRNA and proteins of p300 and PCAF in 54 samples of pediatric astrocytomas embedded in paraffin.

Results: PCAF was not expressed in normal brain tissue.

Flagella from five Cronobacter species induce pro-inflammatory cytokines in macrophage derivatives from human monocytes.

Cronobacter spp. are opportunistic pathogens linked to lie-threatening infections in neonates and contaminated powdered infant formula that has been epidemiologically associated with these cases. Clinical symptoms of Cronobacter include necrotizing enterocolitis, bacteremia, and meningitis.

Detection of fusion genes in formalin-fixed paraffin-embedded tissue sections of rhabdomyosarcoma by RT-PCR and fluorescence in situ hybridization in Mexican patients.

Background And Aims: Rhabdomyosarcoma (RMS) is a pediatric tumor whose classification is based on histological criteria according to two main subgroups, embryonal RMS (ERMS) and alveolar RMS (ARMS). The majority but not all ARMS carry the specific PAX3(7)/FKHR translocation. The type of translocation in patients with ARMS defines the prognosis.

Developmental pattern of the right atrioventricular septal valve leaflet and tendinous cords.

No consensus exists regarding the precise contribution of myocardium and the atrioventricular (AV) cushion mesenchyme to the development of leaflets, tendinous cords (TCs) and papillary muscles. Furthermore, the origin and fate of the myocardium embedded in the immature mesenchyme of the AV cushions at the beginning of AV valvulogenesis is controversial. Some authors have suggested that these cells result from a mesenchyme-to-myocardium transformation.

Aneurysmal bone cyst of the maxilla.

An aneurysmal bone cyst of the maxilla is a nonneoplastic, uncommon, solitary bone lesion recognized by distinct radiographic and histopathological characteristics. It is described as a localized and quickly expandable benign tumor, which can reach a considerable size. It is characterized by the replacement of bone by spongy fibro-osseous tissue and a locally destructive and multicystic lesion filled with blood.