Publications by authors named "Warner Alpizar-Alpizar"

Background: -associated disease (CDAD) is a major healthcare-associated infection. New treatment options for CDAD are needed. A traditional Chinese medicinal formula, Huo Xiang Zheng Qi (HXZQ), was chosen to test against CDAD in a mouse model.

View Article and Find Full Text PDF

Helicobacter pylori colonizes the stomach and induces an inflammatory response that can develop into gastric pathologies including cancer. The infection can alter the gastric vasculature by the deregulation of angiogenic factors and microRNAs. In this study, we investigate the expression level of pro-angiogenic genes (ANGPT2, ANGPT1, receptor TEK), and microRNAs (miR-135a, miR-200a, miR-203a) predicted to regulate those genes, using H.

View Article and Find Full Text PDF

Introduction: colonizes the gastric mucosa and induces chronic inflammation.

Methods: Using a mouse model of -induced gastritis, we evaluated the mRNA and protein expression levels of proinflammatory and proangiogenic factors, as well as the histopathological changes in gastric mucosa in response to infection. Five- to six-week-old female C57BL/6N mice were challenged with SS1 strain.

View Article and Find Full Text PDF

Background: Costa Rica is ranked as one of the countries with highest incidence of gastric cancer worldwide. Previous studies in Costa Rican populations have revealed associations between gastric cancer risk and several cytokine polymorphisms that seem to play a role in the regulation of the expression of these proteins. In this study, we assessed associations of the polymorphisms IL-6-174 G/C, IFNGR1-56 C/T, IL-8-251 T/A and TNF-A (-857 C/T, -308 A/G) with gastric pathologies in a high-risk population of Latin America.

View Article and Find Full Text PDF

(1) Background: Persistent infection is the most important risk factor for gastric cancer. The urokinase receptor (uPAR) is upregulated in lesions harboring cancer invasion and inflammation. Circumstantial evidence tends to correlate colonization with increased uPAR expression in the human gastric epithelium, but a direct causative link has not yet been established in vivo; (2) Methods: In a mouse model of -induced gastritis, we investigated the temporal emergence of uPAR protein expression in the gastric mucosa in response to (SS1 strain) infection; (3) Results: We observed intense uPAR immunoreactivity in foveolar epithelial cells of the gastric corpus due to de novo synthesis, compared to non-infected animals.

View Article and Find Full Text PDF

Gastric cancer (GC) is one of the most important malignancies worldwide because of its high incidence and mortality. The very low survival rates are mainly related to late diagnosis and limited treatment options. GC is the final clinical outcome of a stepwise process that starts with a chronic and sustained inflammatory reaction mounted in response to infection.

View Article and Find Full Text PDF

Justification: The prevalence of gastric cancer (GC) with increased expression of the HER2 oncoprotein shows important variations worldwide. Incidence and mortality rates of GC in Costa Rica are among the highest in Latin America and the world; however, the prevalence of HER2-positive cases in this country is unknown. Evaluation of this parameter is important to decide the therapeutic approach for GC patients.

View Article and Find Full Text PDF

Background: Gastric cancer is one of the leading causes of cancer death worldwide. Surgery is regarded as the best curative treatment option for gastric cancer; however, a high proportion of cases are diagnosed at advanced stages, when tumors are unresectable. In the present study, we evaluated the impact of pharmacological therapies in the survival of 168 patients diagnosed with metastatic gastric cancer from Costa Rica, a country with very high incidence and mortality rates for this malignancy.

View Article and Find Full Text PDF

() infection is a well-established risk factor for the development of gastric cancer (GC), one of the most common and deadliest neoplasms worldwide. infection induces chronic inflammation in the gastric mucosa that, in the absence of treatment, may progress through a series of steps to GC. GC is only one of several clinical outcomes associated with this bacterial infection, which may be at least partially attributed to the high genetic variability of .

View Article and Find Full Text PDF

Background: Gastric cancer is one of the major causes of cancer-related deaths in several Latin-American countries, including Costa Rica. However, determinants of poor outcomes are fairly unknown for patients from this region. The aim of this study was to determine prognostic variables of overall survival (OS) in a cohort of Hispanic patients after curative-intent surgery for gastric cancer.

View Article and Find Full Text PDF

The tissue inhibitor of metalloproteinase-1 (TIMP-1) inhibits the extracellular matrix-degrading activity of several matrix metalloproteinases, thereby regulating cancer cell invasion and metastasis. Studies describing the expression pattern and cellular localization of TIMP-1 in gastric cancer are, however, highly discordant. We addressed these inconsistencies by performing immunohistochemistry and in situ hybridization analyses in a set of 49 gastric cancer lesions to reexamine the TIMP-1 localization.

View Article and Find Full Text PDF

Metastatic growth by colorectal cancer cells in the liver requires the ability of the cancer cells to interact with the new microenvironment. This interaction results in three histological growth patterns of liver metastases: desmoplastic, pushing, and replacement. In primary colorectal cancer several proteases, involved in the degradation of extracellular matrix components, are up-regulated.

View Article and Find Full Text PDF

Several members of the Ly-6/uPAR (LU)-protein domain family are differentially expressed in human squamous epithelia. In some cases, they even play important roles in maintaining skin homeostasis, as exemplified by the secreted single domain member, SLURP-1, the deficiency of which is associated with the development of palmoplantar hyperkeratosis in the congenital skin disorder Mal de Meleda. In the present study, we have characterized a new member of the LU-protein domain family, which we find to be predominantly expressed in the stratum granulosum of human skin, thus resembling the expression of SLURP-1.

View Article and Find Full Text PDF

Gastric cancer is the second cancer causing death worldwide. The five-year survival for this malignancy is below 25% and few parameters have shown an impact on the prognosis of the disease. The receptor for urokinase plasminogen activator (uPAR) is involved in extracellular matrix degradation by mediating cell surface associated plasminogen activation, and its presence on gastric cancer cells is linked to micrometastasis and poor prognosis.

View Article and Find Full Text PDF

Adenocarcinomas of lower oesophagus, gastro-oesophageal junction and cardia in humans are highly invasive tumours with poor prognosis. The localisation of urokinase-type plasminogen activator receptor (uPAR) was determined in 66 patients; 60 with adenocarcinomas and six cases with Barrett's oesophagus. uPAR was expressed in nearly all cases of invasive adenocarcinomas by populations of cancer cells, macrophages and myofibroblasts at both the invasion front and the tumour core.

View Article and Find Full Text PDF

Helicobacter pylori infection is one of the most significant risk factors for gastric cancer. The infection is established early in life and persists lifelong leading to a sustained chronic inflammation. Iron is essential for most living organisms.

View Article and Find Full Text PDF

Gastric cancer is the second cancer causing death worldwide. Both incidence and mortality rates vary according to geographical regions. The receptor for urokinase plasminogen activator (uPAR) is involved in extracellular matrix degradation by mediating cell surface associated plasminogen activation, and its presence on gastric cancer cells is linked to micro-metastasis and poor prognosis.

View Article and Find Full Text PDF

Aim: To determine the association of Helicobacter pylori (H pylori) CagA(+) infection and pro-inflammatory polymorphisms of the genes interleukin (IL)-1RN and IL-1B with the risk of gastric atrophy and peptic ulcers in a dyspeptic population in Costa Rica, a country with high incidence and mortality of gastric cancer.

Methods: Seven biopsy specimens, a fasting blood sample and a questionnaire concerning nutritional and sociodemographic factors were obtained from 501 consecutive patients who had undergone endoscopy for dyspeptic symptoms. A histopathological diagnosis was made.

View Article and Find Full Text PDF

Gastric cancer is the second most common cancer associated death cause worldwide. Several factors have been associated with higher risk to develop gastric cancer, among them genetic predisposition. The p53 gene has a polymorphism located at codon 72.

View Article and Find Full Text PDF