Factors associated with fatal cases of acute respiratory infection (ARI) among hospitalized patients in Guatemala.

BACKGROUND: Acute respiratory infection (ARI) is an important cause of mortality in children and adults. However, studies assessing risk factors for ARI-related deaths in low- and middle-income settings are limited. We describe ARI-related death and associated factors among children aged < 2 years and adults aged ≥18 years hospitalized with ARI in Guatemala. METHODS: We used respiratory illness surveillance data in Guatemala from 2007 to 2013. ARI was defined as evidence of acute infection and ≥ 1 sign/symptom of respiratory disease in hospitalized patients. Clinical, sociodemographic, and follow-up data were gathered. Nasopharyngeal/oropharyngeal swabs were collected from patients with ARI and tested for 6 respiratory viruses; urine was collected only from adults with ARI and tested for pneumococcal antigen. Blood cultures and chest radiographs were performed at the physician's discretion. Radiographs were interpreted per World Health Organization guidelines to classify endpoint pneumonia (i.e. suggestive of bacterial pneumonia). Multivariable logistic regression was used to compare characteristics of patients with fatal cases, including those who died in-hospital or were discharged in a moribund state, with those of patients with non-fatal cases. RESULTS: Among 4109 ARI cases identified in hospitalized children < 2 years old, 174 (4%) were fatal. Median age at admission was 4 and 6 months for children with fatal and non-fatal cases, respectively. Factors associated with fatality included low weight-for-age, low family income, heart disease, and endpoint pneumonia; breastfeeding and respiratory syncytial virus (RSV) detection were negatively associated with fatality. Among 1517 ARI cases identified in hospitalized adults ≥18 years, 181 (12%) episodes were fatal. Median age at admission was 57 years for adults with fatal and non-fatal cases. Low body mass index, male sex, kidney disease, and endpoint pneumonia were significantly more common among patients with fatal versus non-fatal cases. CONCLUSIONS: Our findings highlight some of the factors that must be addressed in order to reduce ARI-related mortality, including promotion of good nutrition, breastfeeding, management and prevention of chronic comorbidities, and poverty reduction. Although no specific pathogen increased risk for death, endpoint pneumonia was significantly associated with fatality, suggesting that the pneumococcal conjugate vaccine could contribute to future reductions in ARI-related mortality.

Progastrin overexpression imparts tumorigenic/metastatic potential to embryonic epithelial cells: phenotypic differences between transformed and nontransformed stem cells.

We recently reported that overexpression of progastrin (PG) in embryonic epithelial cells (HEKmGAS cells) increased proliferation of the cells compared to that of control HEKC cells. Here, we report the novel finding that tumorigenic and metastatic potential of HEKmGAS cells is also increased significantly compared to that of HEKC cells. Cell surface-associated annexinA2 (CS-ANXA2) binds PG and is overexpressed on cancer cells, allowing us to successfully use fluorescently labeled PG peptide for enumerating metastatic lesions of transformed/cancer cells in vivo. Next, we examined the hypothesis that increased tumorigenic/metastatic potential of isogenic HEKmGAS versus HEKC cells maybe due to transformed phenotype of stem cells. FACSorting/FACScanning of cells demonstrated significant increases in percent doublecortin-CAM-kinase-like1 (DCLK1)/Lgr5-positive stem cells, coexpressing cluster of differentiation44 (CD44)/CS-ANXA2, in HEKmGAS versus HEKC cells. Distinct differences were noted in the morphology of HEKC versus HEKmGAS spheroidal growths on nonadherent cultures (selective for stem cells). HEKC spheroids were rounded with distinct perimeters (e.g., basement membranes), whereas HEKmGAS spheroids were amorphous with no perimeters. Relative levels of DCLK1/Lgr5/CD44 and ANXA2/ß-catenin/pNFκBp65/metalloproteinases were significantly increased in HEKmGAS versus HEKC cells, growing as monolayer cultures, 3D spheroids (in vitro), or xenografts (in vivo). Interestingly, HEKC cells enriched for CS-ANXA2 developed amorphous spheroids, whereas downregulation of ANXA2 in HEKmGAS clones resulted in loss of matrixmetalloproteinases (MMPs) and re-formation of rounded spheroids, suggesting that high levels of CS-ANXA2/MMPs may impact spheroid morphology. Downregulation of DCLK1 significantly attenuated activation of ß-catenin, with loss of proliferation of HEKmGAS and HEKC cells, suggesting that DCLK1 is required for maintaining proliferation of cells. Our results suggest the novel possibility that transformed stem cells, unlike nontransformed stem cells, coexpress stem cell markers DCLK1 and CD44 with CS-ANXA2.