Search PubMed⌕ Search

Biomedical subjects

Armando Gamboa-Dominguez

Publications and source records attributed to Armando Gamboa-Dominguez.

14 recordsLinked to original sources
PubMed2006

EBV+ lymphoepithelial carcinoma of the parotid gland in Mexican Mestizo patients with chronic autoimmune diseases.

Lymphoepithelial carcinomas of the salivary gland are rare tumors constantly associated with Epstein-Barr virus (EBV) and mainly identified in Asiatic and Greenlander population. Four cases have been described in Caucasians, only two with EBV infection. We describe two cases of parotid gland lymphoepithelial carcinomas in Mexican mestizo women in which chronic latent EBV infection was documented by immunohistochemistry and in situ hybridization. One patient had primary Sjögren's syndrome and the other systemic lupus erythematosus of six and three years of evolution, respectively. Epithelial neoplastic cells showed latency pattern II (LMP1+, EBNA-2-, EBER+) with a dense inflammatory infiltrate composed mainly by CD8+ T lymphocytes. Follow-up excluded nasopharyngeal involvement in both patients. This report expands the ethnic groups in which salivary lymphoepithelial carcinomas associated with chronic latent EBV infection have been described, and illustrates for the first time its association with autoimmune diseases in two women living in a region non-endemic for this unusual neoplasm.

Adult↗
PubMed2006

Differential RNA expression profile by cDNA microarray in sporadic primary hyperparathyroidism (pHPT): primary parathyroid hyperplasia versus adenoma.

BACKGROUND: Differential diagnosis between adenoma and hyperplasia in primary hyperparathyroidism (pHPT) remains a dilemma. The aim of this study was to assess differences in transcriptional genomic expression profiles between sporadic (nonfamilial) parathyroid hyperplasia (SPH), adenoma, and normal tissue. METHODS: Parathyroid tissue from 12 patients with parathyroid adenoma, 3 with SPH, and 2 with normal glands was selected for analysis. Histopathology was reviewed in all cases, and all patients with adenomas presented normocalcemia for a minimum of 6 months after one gland resection. Hybridizations were performed in a microarray containing 19,968 human cDNA clones including contiguous replicates. Direct comparisons were performed with reverse labeling for every different pooled sample entity. Expression levels were analyzed using the SAM, SMA, LIMMA, Cluster, and PAM packages in the R environment for statistical computing. RESULTS: There were significant statistical differences between SPH and adenomas. In the direct comparison, a total of 200 genes showed differential expression (P < 0.03): 61 genes were upregulated (> 1.65-fold increase) and 139 were downregulated (> 1.58-fold decrease) with a B value > 4.68 (99.08% probability of real differential expression). When SPH was compared to normal parathyroid tissue, 50 genes were differentially expressed: 42 were upregulated (> 1.89) and 8 were downregulated (> 1.7) with a B > 4.26 (98.6% probability of real differential expression). At least 17 genes were differentially expressed and able to discriminate SPH from adenoma or normal tissue. Upregulated genes were related to apoptosis inhibition, cell proliferation, transcriptional activity and cell adhesion, among other activities. Downregulated genes were mainly related to ion channel activity, lipopolysaccharides, prostaglandin-d synthase, and integral membrane proteins. CONCLUSIONS: Our data suggest that SPH and adenoma have a singular molecular signature that, theoretically, could be used for the differential diagnosis of these entities and normal parathyroid tissue.

Adenoma↗
PubMed2006

Effects of estradiol and progesterone on gastric mucosal response to early Helicobacter pylori infection in female gerbils.

BACKGROUND: Gender differences have been shown regarding the changes in the inflammatory response, gastrin secretion, and gastric acidity during Helicobacter pylori infection. AIM: To investigate the role of estradiol and progesterone in the changes of the gastric mucosa induced by H. pylori during the early stage of infection in female gerbils. MATERIALS AND METHODS: Thirty-three adult ovariectomized female gerbils were infected with H. pylori (SS1); 7 days after infection they were treated with low and high doses of estradiol (50 and 250 microg/60 days pellet), progesterone (15 and 50 mg/60 days pellet) and vehicle. Non-ovariectomized infected gerbils were used as control. Gerbils were euthanized after 6 weeks of infection. Histologic evaluation, immunohistochemical detection of proliferation cell nuclear antigen (PCNA), gastrin, and apoptosis by terminal deoxynucleotide nick end labeling (TUNEL) assay were performed. Positive cells for PCNA, TUNEL, and gastrin were counted in 10 oriented glands per animal. Two-sided p = .05 was considered significant. RESULTS: Estradiol-treated groups showed more intense and extended acute and follicular gastritis compared to the vehicle group, whereas progesterone-treated groups presented less gastritis than the other groups. Proliferation and apoptosis indexes were significantly lower in the vehicle group when compared with those of the control; both indexes were increased in the high-dose estradiol and progesterone groups as compared with those of the vehicle. Grade I nonmetaplastic atrophy was observed in the vehicle and progesterone groups. The high-dose progesterone group showed a significant reduction in the number of gastrin cells. CONCLUSIONS: Estradiol and progesterone participate in the gastric mucosal response to early H. pylori infection in gerbils.

Animals↗
PubMed2006

Clinical and pathological predictors of the response to neoadjuvant anthracycline chemotherapy in locally advanced breast cancer.

PURPOSE: The aim of this study is to determine clinical and histopathological characteristics correlated to responsiveness to anthracycline-based neoadjuvant chemotherapy in breast cancer. PATIENTS AND METHODS: We studied primary tumor specimens with local advanced breast cancer from 40 patients. Patients received anthracycline-based chemotherapy. Neoadjuvant regimen consisted in 600 mg/m2 5-fluorouracil, 60 mg/m2 doxorubicin, and 600 mg/m2 cyclophosphamide (FAC). The World Health Organization criteria were used to classify the tumors. We performed immunohistochemical staining for ER, PgR, HER-2, PCNA (proliferation cell nuclear antigen), Ki-67, p53, and Bcl-2. Clinical and histopathological characteristics were associated with clinical response and histopathological changes induced by chemotherapy. RESULTS: The mean age was 47 +/- 14 yr. Twenty-three percent of patients were in stage IIB and 77% were in stages IIIA and IIIB. Seven percent of patients had progression of the disease. Stable disease was observed in 42% of patients and 45% had partial response. Only 7% of patients had a complete response. Factors associated with a better and major percentage of clinical response were the administration of doxorubicin-based chemotherapy, administration of more than three cycles, clinical N1, atypia, more than 10 mitosis per high-power field, moderate to severe SBR grade, and a major index of cellular proliferation. CONCLUSION: We found that tumors with large volumes, N2 node status, low cellular proliferation rate, positive immunoreactivity to p53, and low differentiation grade have a lower response to neoadjuvant chemotherapy with anthracycline. These patients could benefit from a different chemotherapy scheme to obtain a better control and resection.

Adult↗
PubMed2005

E-cadherin expression in sporadic gastric cancer from Mexico: exon 8 and 9 deletions are infrequent events associated with poor survival.

Aberrant expression and mutation of E-cadherin is frequent in gastric carcinoma (GC) especially of the diffuse type. The frequency of CDH1 (gene encoding E-cadherin) mutation in populations with high incidence of diffuse GC and its prognostic significance is unknown. One hundred seventy-seven gastrectomies from Mexican mestizo patients with intestinal (53), mixed (55), or diffuse (69) GC were included. In addition, 101 endoscopic biopsies from patients with GC not subjected to surgery were analyzed. Immunohistochemistry against wild-type E-cadherin (clone 36) and against 2 mutation-specific antibodies (MSA) recognizing mutant CDH1 lacking exon-8 (del 8) or exon-9 (del 9) were performed. Staining was correlated with histotype, tumor node metastasis stage, and follow-up. Abnormal or absent E-cadherin expression (clone 36) was identified in 84% GC, predominantly in diffuse or mixed tumors (P = 0.004) in advanced stages (P = 0.003). No survival differences at 1 and 2 years were observed among patients showing normal, abnormal, or absent wild type E-cadherin expression. Overall reactivity with the MSA was observed in 10 (5.6%) patients who were treated with surgery. In 140 patients, dead from the disease or alive with the disease, the survival at 1 and 2 years was 37% versus 17% and 14% versus 0 for patients without and with del 8/9 positivity, respectively (log rank P = 0.01). Biopsies from patients with inoperable-GC (101) rendered 5 (4.95%) with del 8 or 9 immunoreactivity. Abnormal E-cadherin expression is frequent in GC. However, exon 8 or 9 deletions were observed in only 5.3% tumors in this series from Mexico, at a lower rate than previously published, but associated with a worse prognosis.

Adolescent↗
PubMed2004

Epidermal growth factor receptor expression correlates with poor survival in gastric adenocarcinoma from Mexican patients: a multivariate analysis using a standardized immunohistochemical detection system.

The aim of the study was to determine epidermal growth factor receptor (EGFR) expression in gastric adenocarcinoma by standardized immunohistochemistry and to correlate EGFR expression with clinical features and patient survival. EGFR expression was investigated in paraffin sections of resection specimens of 89 gastric carcinomas from Mexican Mestizo patients using standardized immunohistochemistry with antigen retrieval (Dako EGFRpharmDx assay detection system). Membrane staining of EGFR was evaluated in the neoplastic cells and graded using a semiquantitative score (0-3+). Of the 89 carcinomas examined, staining of neoplastic cells was weak in 17 (19.1%, score 1+), moderate in 16 (18.0%, score 2+), and strong in nine cases (10.1%, score 3+). EGFR reactivity was heterogeneous, frequently showing completely negative up to 3+ positive areas within an individual tumor. EGFR reactivity score correlated with distant metastases (P=0.002) and clinical stage (P=0.033). EGFR score 0/1+ was significantly associated with an increase in patient survival when compared to score 2+/3+ (P=0.0006). In a multivariate analysis, EGFR positive cells in muscularis or subserosa (P=0.004), distant metastases (P=0.016) and residual disease (P=0.039) were significantly correlated with decreased survival. The prognosis was associated with the EGFR reactivity score (P=0.003), distant metastases (P=0.0001) and residual disease (P=0.012) in a univariate analysis. EGFR reactivity in neoplastic cells is an independent prognostic factor in gastric adenocarcinoma. The relevance of the heterogeneity in EGFR expression with regard to tumor progression, metastasis and anti-EGFR therapy needs to be studied.

Adenocarcinoma↗
PubMed2004

Anorectal melanoma: report of three cases with extended follow-up.

Primary anorectal melanoma is rare. There is controversy regarding the best surgical treatment because of its poor prognosis. Three cases with extended follow-up are reported in this article. A 53-year-old woman with rectal bleeding was diagnosed with a melanoma of the rectum and underwent an abdominoperineal resection. The patient died with distant metastases 8 months later. An 80-year-old woman with rectal bleeding was diagnosed with a melanoma of the rectum and underwent a transanal local excision. She remains alive 4 years later but with locally recurrent disease. A 78-year-old man with rectal bleeding was diagnosed with a melanoma of the rectum and underwent an abdominoperineal resection. He died with local and metastatic disease 25 months later. Recent trends favor local excision when technically feasible, although some patients may require an abdominoperineal resection of the rectum, especially for larger tumors.

Aged↗
PubMed2004

Cellular proliferative fraction measured with topoisomerase IIalpha predicts malignancy in endocrine pancreatic tumors.

CONTEXT: Endocrine pancreatic tumors (EPTs) are rare lesions with varying biological behavior. Establishing malignancy is a challenge for clinicians and pathologists. OBJECTIVE: To establish the role of proliferative, apoptotic, angiogenic, and hormonal markers as predictors of malignancy in EPTs. DESIGN: Paraffin-embedded EPT samples were studied for prognostic markers. PATIENTS: Twenty-one consecutive patients with a diagnosis of EPT. MAIN OUTCOME MEASURES: The proliferative fraction (topoisomerase IIalpha), microvascular density (CD34), vascular endothelial growth factor expression, and estrogen receptor-beta (ERbeta) expression were studied by immunohistochemistry on all EPTs. Apoptosis was also assessed with terminal deoxynucleotidyl transferase nick-end labeling. RESULTS: We identified 13 benign and 8 malignant tumors. Topoisomerase IIalpha was significantly increased in malignant tumors (P =.001), while there were no differences in apoptosis, microvascular density, or vascular endothelial growth factor expression in association with malignancy. No correlation could be identified between microvascular density and vascular endothelial growth factor expression, and ERbeta was not detected. A receiver operating characteristic curve for topoisomerase IIalpha disclosed that above a labeling index of 13, the test had 88% sensitivity and 100% specificity for predicting malignancy. CONCLUSION: Cellular proliferation measured with topoisomerase IIalpha is a simple prognostic marker for malignancy in EPTs, unlike apoptosis, angiogenesis, or the presence of ERbeta, which were not associated with malignant behavior. These findings designate a defined field for future research on endocrine pancreatic carcinogenesis and a possible target for chemotherapeutic agents.

Adolescent↗
PubMed2003

Influence of tumor-associated E-cadherin mutations on tumorigenicity and metastasis.

In this study, we investigated whether tumor-associated E-cadherin mutations impair the tumor-suppressive function of the cell adhesion molecule and influence metastasis formation in a severe combined immunodeficiency mouse model. The investigated E-cadherin mutations were in frame deletions of exons 8 (del 8) or 9 (del 9) and a point mutation in exon 8 (p8). Transfected human MDA-MB-435S carcinoma cells stably expressing wild-type (wt) or mutant E-cadherin were injected into the mouse mammary fat pad. Mice transplanted with wt E-cadherin transfectants developed significantly smaller tumors than animals transplanted with the E-cadherin-negative parental cell line. Animals transplanted with del 9 or p8 E-cadherin transfectants produced medium size tumors, indicating that these mutations impair the tumor-suppressive function of E-cadherin. In contrast, mice transplanted with del 8 E-cadherin transfectants developed tumors of approximately the same sizes as animals transplanted with wt E-cadherin expressing cells. Lung metastases were induced by all cell lines without significant differences. Immunohistochemical analysis of E-cadherin expression in the tumors revealed a heterogeneous staining pattern, indicating loss or down-regulation of E-cadherin in some tumor cells. Metastases were completely negative for E-cadherin. Our data suggest that the type of mutation determines whether the tumor-suppressive function of E-cadherin is impaired.

Animals↗
PubMed2003

Disseminated encephalitozoon cuniculi infection in a Mexican kidney transplant recipient.

BACKGROUND: No cases of Encephalitozoon cuniculi infection have been reported in transplant patients. METHODS: A 42-year-old man received a renal transplant 8 months earlier because of terminal glomerulonephritis and was admitted with cough, fever, diarrhea, abdominal pain, and colon wall thickening. While under rapamycin (2 g/day), cyclosporine A (4.4 mg/kg/day), and prednisone (100 mg/day) therapy, he developed Banff grade IB graft rejection and was treated with methylprednisolone (1 g/day) for 3 days and oral prednisone (60 mg/d). RESULTS: Microbiologic studies were inconclusive, and biopsy specimens of ileum, colon, liver, and the grafted kidney revealed numerous gram-positive microsporidia spores. Parasitophorous vacuoles containing various developing stages of Encephalitozoon were seen. Immunofluorescence studies identified the etiologic agent as E. cuniculi. Albendazole therapy resulted in clinical improvement but no eradication after 10 months of follow-up. CONCLUSIONS: This report describes what is, to the authors' knowledge, the first case of disseminated E. cuniculi infection in a kidney transplant human immunodeficiency virus-negative patient from Mexico.

Adult↗
PubMed1999

Myelolipoma: A New Adrenal Finding in Carney's Complex?

Pigmented nodular cortical hyperplasia. a rare cause of Cushing's syndrome, is characterized by resistance to inhibition with dexamethasone and normal sized adrenal glands with multiple, small, pigmented nodules. The disorder may be a component of a syndrome inherited as an autosomal dominant pattern that includes intra- and extracardiac myxomas, lentiginous lesions, blue nevi, other functional endocrire tumors, and perppheral nerve tumors (Carney's complex). We report a patient in whom bilateral myelolipomas were found, in addition to the usual features of this complex. A 29-yr old man was admitted to the hospital for Cushing's syndrome of probably more than 15 yr duration. Physical examination showed diffuse facial hyperchromatic macules. 02-05 cm, predominantly around the lips and on the palmar surfaces of the fingers. Results with dexamethasone suppression nocturnal testing (1 and 8 mg) were compatible with an adrenal adenoma. The computed tomography (CT) of the sella turcica was normal. Adrenal CT showed a tumor in the left gland with a double component one solid and another suggestive of fat, consistent with an angiomyelolipoma. Following 5 wk treatment with ketoconazole, 800 mg per day po, serum cortisol decreased to 5.9 Ag/dL. morning and evening, respectively. Bilateral adrenalectomy was performed. Pathologic examination revealed pigmented nodular cortical hyperplasia and a dominant myelolipoma in the left adrenal. A microscopic myelolipoma was identified in the right adrenal. An echocardiogram showed a mass on the posterior wall of the left ventricle which was a myxoma. Study of the patient's family disclosed two sisters with facial lentigines. Echocardiograms were performed on all available first degree relatives: all were normal. Nocturnal inhibition with dexamethasone revealed that one of the patient's sisters with lentigines also had hypercortisolism. Myelolipoma has been reported in association to Cushing syndrome in humans and experimentally after pituitary extracts in animals. The relationship between this finding and the Carney's complex remain elusive.

Journal Article↗
PubMed1999

Metastatic Follicular Variant of Papillary Thyroid Carcinoma Manifested as a Primary Renal Neoplasm.

Although autopsies performed on patients with cancer have shown 4 6 to 7.6% of metastases to the kidneys, the preoperative clinical identification remains rare. The primary sources of metastases to the kidney are in decreasing order of frequency: breast, lung, intestine, contralateral kidney, stomach, ovary, cervix, pancreas, uterus, and pro tate. As far as we know, only seven cases of malignant neoplasms of the thyroid gland metastatictothe kidney have been reported [1]. Herein, we report the eighth case of this event and the second of a follicular variant of papillary thyroid carcinoma whose initial manifestation was hematuria and flank pain.

Journal Article↗
PubMed1996

Macrofollicular Variant of Papillary Thyroid Carcinoma: A Case and Control Analysis.

The planimetric, flow cytometric, and immunohistochemical characteristics of the macrofollicular variant of papillary thyroid carcinoma (MFVPTC) have not been reported before. The clinical, morphological, immunohistochemical, planimetric, and flow cytometric characteristics of six cases of the MFVPTC and six of the follicular variant of papillary thyroid carcinoma (FVPTC) were analyzed. Patients had undergone surgical treatment. The mean age was 38 (range 29-64 yr), and five were women. Tumors had a mean size of 3.2 cm (range 0.3-4.5 cm). Half were originally diagnosed as goiter. Macrofollicles had a mean diameter of 345.5 um, perimeter of 1237 um, and area of 13,779 um(2), with nuclear changes of PTC. Mean follow-up was 107 mo (range 12-277), and neither lymph node metastases nor recurrence were seen. Differences in diameter, perimeter, and area between the macrofollicular and follicular variants were found. Follicular neoplastic cells were thyroglobulin and 5-100 protein positive in macrofollicles and normofollicles. All were negative to cytokeratin and to high-mol-wt keratin. All tumors were diploid. There were no significant differences in follow-up, DNA content, nor immunohistochemical reactivity. Differences in diameter (p < 0.00006), perimeter (p < 0.0001), and area (p < 0.001) were observed. It is important to recognize this variant because it could be misdiagnosed as benign thyroidal lesions.

Journal Article↗