IRF6, RYK, and PAX9 expression in facial tissue of children with cleft palate / Expresión de IRF6, RYK y PAX9 en el tejido facial de niños con paladar fisurado

Cleft lip and palate (CLP) is a congenital anomaly characterized by the inappropriate fusion of the upper lip, alveolus, and secondary palate. This study investigated whether expression of interferon regulatory fac tor 6 (IRF6), receptor-like tyrosine kinase (RYK), and paired-box 9 (PAX9), which are essential for the normal development and morphogenesis of craniofacial structures, is dysregulated in children with CLP. Oral mucosa tissue samples were obtained from patients with complete bilateral (CB) CLP (n= 19) during corrective plastic surgery and unaffected control subjects (n= 7). IRF6, RYK, and PAX9 expression was assessed by immunohistochemistry, and data were analyzed with the Mann-Whitney test. In patients, IRF6 immunoreactivity in the connective tissue was moderate to high, but the overall number of IRF6-positive oral epithelial cells was lower than that in controls (z= -3.41; P= 0.01). RYK expression was observed only sporadically in the oral epithelium of 4 patients, in contrast to the control group (z= -3.75; P< 0.001). PAX9-positive epithelial cells were present in low to moderate numbers in patients with CBCLP, while an abundance of these cells was observed in the basal layer of the oral epithelium in controls (z= -3.60; P<0.001). IRF6 is the main connective tissue regulatory factor in CBCLP, and its low level of expression in the oral epithelium suggests a reduced potential for epitheliocyte differentiation, while low PAX9 and RYK expression may explain the decreased cell migration and cleft remodeling in CBCLP.

La fisura labial y palatina (FLP) son anomalías congénitas caracterizadas por la fusión inadecuada del labio superior, alvéolo y paladar secundario. En este estudio se investigó si en niños con FLP hay una desregulación de la expresión del factor regulador de interferón 6 (IRF6), del receptor de la tirosina quinasa (RYK), y del factor de transcripción PAX9, que son esenciales para el desarrollo normal y la morfogénesis de las estructuras craneofaciales. Se obtuvieron muestras de la mucosa oral de pacientes con FLP completa bilateral (CB) (n= 19), tomadas durante la realización de cirugía plástica correctiva, y de sujetos de control no afectados (n= 7). Se evaluó la expresión de IRF6, RYK y PAX9 por inmunohistoquímica, y los datos se analizaron con la prueba de Mann-Whitney. En los pacientes, la inmunoreactividad de IRF6 en el tejido conectivo fue de moderada a alta, pero el número total de células epiteliales orales positivas para IRF6 fue menor que en los controles (z= -3,41; P= 0,01). La expresión de RYK se observó sólo esporádicamente en el epitelio oral de 4 pacientes, en contraste con el grupo control (z= -3,75; P<0.001). Células epiteliales positivas para PAX9 estaban presentes en números bajos a moderados en pacientes con FLP completa bilateral, mientras que se observó una abundante cantidad de estas células en la capa basal del epitelio oral en los controles (z= -3,60; P<0,001). IRF6 es el principal factor regulador del tejido conectivo con FLP completa bilateral, y su bajo nivel de expresión en el epitelio oral sugiere un potencial reducido para la diferenciación del epitelio, mientras que la expresión baja de PAX9 y RYK pueden explicar la disminución de la migración celular y la remodelación de la fisura con FLP completa bilateral.

Expression of immunohistochemical markers in patients with AIDS-related lymphoma

AIDS-related lymphomas (ARL) present high biological heterogeneity. For better characterization of this type of lymphoma, the objectives of the present study were to evaluate the expression of immunohistochemical markers of cell differentiation (CD10, Bcl-6, MUM-1) and determine cell origin profile according to Hans' classification of diffuse large B-cell lymphoma in AIDS patients. This study included 72 consecutive patients with ARL diagnosed at the University Hospital, Universidade Federal do Rio de Janeiro (UFRJ) and at the Brazilian Instituto Nacional de Câncer (INCA) from 2000 to 2006. The morphologic distribution of the lymphomas was the following: 61 percent were diffuse large B-cell lymphomas (DLBCLs), 15 percent were Burkitt's lymphomas, 13 percent were plasmablastic lymphomas, 10 percent were high-grade lymphomas and 1 percent was follicular lymphoma. The positivity for each immunohistochemical marker in DLBCLs, Burkitt's lymphoma and plasmablastic lymphoma was respectively: CD20, 84 percent, 100 percent, and 0; CD10, 55 percent, 100 percent, and 0; Bcl-6, 45 percent, 80 percent, and 0; MUM-1, 41 percent, 20 percent, and 88 percent. A higher positivity of CD20 (84 percent x 56 percent, p = 0.01) was found in DLBCL compared to non-DLBCL; in Burkitt's lymphomas a higher positivity of CD10 (100 percent x 49 percent, p = 0.04) and Bcl-6 (80 percent x 39 percent, p = 0.035) were found compared to non-Burkitt's lymphomas. Germinal center (GC) profile was detected in 60 percent of DLBCLs. Our study suggests particular findings in ARL, as the most frequent phenotype was GC, different from HIV-negative patients.

Factors Influencing the Response to High Dose Methotrexate-based Vincristine and Procarbazine Combination Chemotherapy for Primary Central Nervous System Lymphoma

The authors investigated objective response rate to high dose methotrexate (HDMTX)-based combination chemotherapy in primary central nervous system lymphoma (PCNSL), and sought to identify factors that influence response to HDMTX-based combination therapy. Prospective observational analysis was performed on 52 PCNSL patients. All patients received HDMTX (3.5 g/m2) and vincristine (1.4 mg/m2/day) for one day during weeks 1, 3, 5, 7, and 9, and procarbazine (100 mg/m2/day) for one week during weeks 1, 5, and 9. Forty-one patients (78.8%) achieved complete or partial remission. Higher objective response rates were observed for patients with: 1) age < 60 yr; 2) Eastern Cooperative Oncology Group (ECOG) performance score of < 2; 3) low risk status as defined by the International Extranodal Lymphoma Study Group; 4) p53 positivity; 5) XBP-1 negativity; 6) MUM-1 negativity; and 7) homogenous gadolinium enhancement in MR images. Multivariate analysis showed that ECOG performance score of < 2, low risk, negativity for XBP-1, homogenous gadolinium enhancement by MRI, and response to chemotherapy were associated with longer overall survival. In particular, it is interesting to note that patients with a PCNSL that is homogenously enhanced by gadolinium have a higher objective response rate, and a longer progression-free survival and overall survival.

Intrinsic Cellular Defenses against Virus Infection by Antiviral Type I Interferon

Intrinsic cellular defenses are non-specific antiviral activities by recognizing pathogen-associated molecular patterns (PAMPs). Toll-like receptors (TLRs), one of the pathogen recognize receptor (PRR), sense various microbial ligands. Especially, TLR2, TLR3, TLR4, TLR7, TLR8 and TLR9 recognize viral ligands such as glycoprotein, single- or double-stranded RNA and CpG nucleotides. The binding of viral ligands to TLRs transmits its signal to Toll/interleukin-1 receptor (TIR) to activate transcription factors via signal transduction pathway. Through activation of transcription factors, such as interferon regulatory factor-3, 5, and 7 (IRF-3, 5, 7) or nuclear factor-kappaB (NF-kappaB), type I interferons are induced, and antiviral proteins such as myxovirus-resistance protein (Mx) GTPase, RNA-dependent Protein Kinase (PKR), ribonuclease L (RNase L), Oligo-adenylate Synthetase (OAS) and Interferon Stimulated Gene (ISG) are further expressed. These antiviral proteins play an important role of antiviral resistancy against several viral pathogens in infected cells and further activate innate immune responses.