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Javier Vargas

Publications and source records attributed to Javier Vargas.

9 recordsLinked to original sources
PubMed2004

Intronic deletion affecting a negative regulatory region of TP73 is related to breast and colorectal carcinomas.

The TP73 gene encodes a nuclear protein that has high homology with TP53. TP73 is rarely mutated in human cancer. The presence of a 1-kb regulatory fragment within the first intron of TP73 was recently reported. This fragment exerts silencer activity on TP73 mediated by ZEB. We searched for possible mutations in this negative regulatory region in 45 colorectal and 43 breast cancer patients and in 34 healthy donors. The study was carried out using the SSCP method, and the allelic variants detected were sequenced. The expression of TP73 was analyzed by quantitative RT-PCR, and loss of heterozygosity (LOH) was assessed by microsatellite study. In several samples, we identified an allele variant that corresponds to a deletion of 73 bp in tumor tissues and normal counterparts, localized between -489 and -417 from the ATG start site of exon 2. Among the 88 tumor samples, 35 (40%) showed at least 1 allele with the cited deletion, versus 7 of the 34 (21%) healthy donors (P = 0.045). When we classified the patients according to the number of variations into homozygous or heterozygous groups, the significance was clearer (P = 0.03). No LOH was detected in the heterozygous cases. There was a positive quantitative correlation between the expression of TP73 and the presence of the allelic variant (P = 0.029). These data suggest that this allelic variant is common in breast and colorectal cancers and that it could alter the expression of the TP73 gene with an additive effect.

Base Sequence↗
PubMed2003

Endometrial intraepithelial neoplasia diagnosed at endometrial resection.

The literature has no reported cases of isolated endometrial intraepithelial neoplasia found at endometrial resection. If endometrial cancer is occult it might not be detected at diagnostic hysteroscopy or during resection, especially if destructive techniques are used. A 51-year-old woman had history of menorrhagia, with diagnostic hysteroscopy showing benign functional endometrium and diagnosed as dysfunctional uterine bleeding. Endometrial resection was performed and the pathologic examination in one stripe of resected tissue found focal, isolated endometrial intraepithelial neoplasia. This case reinforces the importance of pathologic tissue examination after endometrial ablation. Care must be taken when performing second-generation nonhysteroscopic ablation techniques, as even with direct visualization a premalignant lesion can be missed.

Carcinoma in Situ↗
PubMed2002

Extracellular matrix glycoproteins inhibit neurite production by cultured neurons.

We have analyzed the role of extracellular matrix glycoproteins in the formation of a bipolar outgrowth pattern of identified leech neurons in culture. Adult anterior pagoda (AP) neurons cultured on the inner surface of the ganglion capsules that surround central nervous system, generate two processes oriented in opposite directions. This pattern differs from those produced by these neurons cultured on other substrates, and is similar to the pattern of developing AP neurons at embryonic day 10. We used different lectins to identify subsets of glycoproteins in the extracellular matrix (ECM) of the capsules and to study their contribution to the formation of the bipolar outgrowth pattern. ECM glycoproteins binding to peanut agglutinin (PNA) or Galanthus nivalis aglutinin (GNA) lectins were detected in ganglion capsules and in ganglion extracts that had been separated by electrophoresis and blotted to nitrocellulose membranes. Four protein bands bound to PNA lectin and six other bands, including laminin subunits, bound to GNA lectin. Other lectins failed to recognize any of the proteins. For AP neurons cultured on capsules, addition of PNA lectin to the culture medium produced a dose-dependent increase in the number of primary neurites without affecting their shape, length or number of branch points. However, PNA lectin used as substrate did not affect sprouting of AP neurons. Our results suggest that PNA-binding extracellular matrix glycoproteins regulate the formation of the bipolar pattern of AP neurons by inhibiting the formation of neurites.

Animals↗
PubMed2002

Steps in the formation of a bipolar outgrowth pattern by cultured neurons, and their substrate dependence.

We studied the steps in the formation of the bipolar outgrowth pattern of cultured adult Anterior Pagoda (AP) neurons of the leech growing on a central nervous system (CNS) homogenate as substrate. This pattern, which consists of two primary neurites directed in opposite directions plus some bifurcations, resembles their embryonic pattern but is different from the patterns they develop in culture on leech laminin or Concanavalin A as substrates. In eight neurons that were studied, one primary neurite formed and branched several hours before the second one. Time-lapse video analysis showed that between 12 and 36 h of growth, the more proximal branch of the early neurite migrated retrogradely, rotated, and formed the second primary branch. Both neurites elongated until the total neurite length reached 130-160 microm, when the elongation of primary neurites became synchronous with the retraction of secondary processes, suggesting competition. The substrate dependence of these events was tested by plating AP neurons on leech laminin. On this substrate AP neurons produced multiple independent primary neurites with branches. Retraction of some large branches was followed by their regrowth, and did not correlate with the changes in other neurites. We propose that the dynamics in the formation of the bipolar outgrowth pattern of AP neurons arise from inhibitory extracellular matrix molecules, which reduce the synthesis of precursors for neurite formation.

Animals↗
PubMed2002

Peanut and Amaranthus leucocarpus lectins discriminate between memory and naive/quiescent porcine lymphocytes.

Lectins are relevant tools to isolate and characterize different cellular sub-populations. In this work, we used the lectins Arachis hypogaea (Peanut agglutinin, PNA) and Amaranthus leucocarpus (ALL), specific for Galss1, 3GalNAc, to characterize naive and memory lymphocytes from pigs, experimentally infected with the porcine rubulavirus (RvP). Our results showed that both lectins recognized preferentially lymphocytes with the CD4(+)CD8(+) phenotype (P<0.05). The phenotypic analysis of the cells recognized by these lectins indicated that PNA(+) lymphocytes showed higher rate of the CD29 antigen (PNA(+)CD29(high)) than ALL(+) (ALL(+)CD29(low)). The number of PNA(+)CD29(high) lymphocytes increased after 8 weeks of experimental infection with RvP, and most of the ALL(+)CD29(low) cells became CD29(middle). PNA(+) lymphocytes isolated from infected pigs proliferated after stimulation with the RvP, whereas ALL(+) cells did not. In vitro assays indicated that the ALL(+) cells from previously infected pigs diminished from 7.5 +/- 2 to 0.5 +/- 0.3% after RvP stimulation; whereas PNA(+) cells increased from 4 +/- 1 to 42 +/- 2%, whereas no modification in ALL(+) or PNA(+) cellular population was identified in lymphocytes from naive animals after RvP stimulation. Our results suggest that the cellular distribution/organization of the O-glycosydically linked glycans on lymphocytes may correlate with biological functions, and that PNA could be a tool to isolate specifically porcine memory T cell subsets, whereas ALL could be useful to isolate naive/quiescent T lymphocytes.

Animals↗
PubMed2002

Fine-needle aspiration biopsy of the retroperitoneum: a series of 111 cases not including specific organs.

We report on our experience in fine-needle aspiration (FNA) biopsy of the retroperitoneum: 111 FNA biopsies performed on 99 patients. Cytologic diagnoses were divided into four groups: nondiagnostic (unsatisfactory samples because of a low cellularity and/or improperly prepared smears) aspirates (20%), benign (16%), suspicious for malignancy (13%), and malignant (50%). There were no known false-positive samples. We had two false-negative diagnoses due to sampling errors. Among diagnostic smears, the procedure showed a sensitivity of 97% and a specificity of 100%. The predictive value of a positive result was 100% and the predictive value of a negative result was 90%. The overall accuracy was 98%. Metastatic carcinomas accounted for the largest number of lesions in the group of malignant tumors. A primary tumor site was known for the majority of the cases before the aspiration was performed. In the remaining cases we were unable to suggest an origin. It is therefore important to emphasize the role of ancillary studies in patients that are at the first assessment of the disease or when a second intercurrent malignancy is suspected. In our limited experience, a suggestion of the correct subtype of retroperitoneal sarcoma was not possible. As in the rest of cytopathology, a multidisciplinary approach is mandatory in this setting to improve patient management.

Adult↗
PubMed2002

Increased expression of T cell chemokines and their receptors in chronic hepatitis C: relationship with the histological activity of liver disease.

OBJECTIVES: Although chemokines seem to be important in certain inflammatory disorders, little is known about the role of these proteins in chronic hepatitis C. METHODS: Expression of selected CXC and CC chemokines and their receptors was assessed by immunohistochemistry and flow cytometry in chronic hepatitis C. Tissue samples from normal liver and that of sustained responders were also evaluated. A comparative analysis between the histological grading and the intrahepatic expression level of chemokines was performed. RESULTS: The majority of liver-derived T lymphocytes expressed CXCR3 and CCR5 chemokine receptors, representing high enrichment over levels of CXCR3 + and CCR5 + T cells in blood from chronic hepatitis C. An intense intrahepatic expression of their respective ligands, the CXC chemokine Mig, and RANTES, was detected in the same patients studied, being restricted to the sinusoidal endothelium and to hepatocytes, respectively. A statistically significant association between the intrahepatic chemokine expression level and the inflammatory activity of chronic hepatitis C was found. Of note was the marked expression of both CXCR3 and its ligand Mig on endothelial cells from portal neovessels in chronic hepatitis C. CONCLUSIONS: Intrahepatic chemokine signaling could play a key role regulating significant pathological events during chronic hepatitis C, opening new avenues for therapeutic interventions based on chemokine activities.

Adult↗
PubMed2002

Mitotically active juvenile xanthogranuloma.

Juvenile xanthogranuloma is a histiocytic inflammatory disorder capable of presenting different histologic patterns. The classic form consists of sheets of foamy histiocytes and numerous multinucleated Touton-type giant cells containing no to very few mitotic figures. Nonlipidized juvenile xanthogranuloma consists of a diffuse monomorphic histiocytic infiltrate and usually shows a slightly higher mitotic index. Histologic hematoxylin-eosin staining techniques were used after excision of a pink ulcerated nodule in a 2-year-old girl. Histopathologic examination showed a nonencapsulated cellular proliferation mainly occupying dermis, but extending into the subcutaneous tissue as well. Most of the cells were epithelioid histiocytes, but foamy and Touton giant cells were also evident. The most striking feature was the presence of a high number of mitotic figures, as many as 23 per 10 high-power fields. We present an unusual case of classic juvenile xanthogranuloma with areas similar to those found in the nonlipidized type and with a high mitotic index.

Child, Preschool↗