[Frequency of diabetic retinopathy and associated factors in Puerto Montt, Chile]. / Estudio de prevalencia de retinopatía diabética en pacientes diabéticos tipo 2 de la comuna de Puerto Montt y sus factores asociados.

BACKGROUND: Diabetic retinopathy (DR) is an important cause of decreased visual acuity, whose prevalence has increased between 1990 and 2020. In Chile the prevalence of diabetic retinopathy was estimated at 24.8%. AIM: To assess the prevalence of DR in a southern Chilean city. MATERIAL AND METHODS: From a database of diabetic patients attending primary health care centers at Puerto Montt, Chile, 196 patients with DR and 392 patients without DR, matched by age and presence of chronic complications, were chosen for this case-control study. RESULTS: The prevalence of DR in the database of diabetic patients was 33.3%. glycated hemoglobin, the frequency insulin use, systolic blood pressure, HDL cholesterol, microalbuminuria, and proteinuria were significantly worse in cases. A multivariate analysis showed that retinopathy is much more likely to occur when the variables insulin use, neuropathy, and microalbuminuria concur. CONCLUSIONS: DR was associated with worse metabolic parameters and the presence of neuropathy in this case control study.

Low-Normal Thyroid Function Is Not Associated with Either Non-Alcoholic Fatty Liver Disease or with Metabolic Dysfunction-Associated Fatty Liver Disease.

BACKGROUND: The association of low-normal thyroid function (LNTF) with non-alcoholic fatty liver disease (NAFLD) or metabolic dysfunction-associated fatty liver disease (MAFLD) is controversial; thus, the aim of this study is to determine this association. METHODS: NAFLD was evaluated by controlled attenuation parameter of transient elastography. Patients were classified by MAFLD criteria. LNTF was defined as TSH levels of 2.5 to 4.5 mIU/L and were divided into three different cut-off points (>4.5 to 5.0, >3.1, and >2.5 mIU/L). Associations between LNTF, NAFLD, and MAFLD were evaluated by univariate and multivariate logistic regression analyses. RESULTS: A total of 3697 patients were included; 59% (n = 2179) were male, and median age and body mass index were 48 (43-55) years and 25.9 (23.6-28.5) kg/m2, respectively, and 44% (n = 1632) were diagnosed with NAFLD. THS levels of 2.5 and 3.1 showed significant associations with the presence of NAFLD and MAFLD; however, LNTF did not show an independent association with the presence of NAFLD or MAFLD in multivariate analysis. According to different cut-off points, patients with LNTF presented similar risks for NAFLD as the general population. CONCLUSION: LNTF is not associated with NAFLD or MAFLD. Patients with high LNTF are equally at risk for NAFLD as the general population.

Estudio de prevalencia de retinopatía diabética en pacientes diabéticos tipo 2 de la comuna de Puerto Montt y sus factores asociados / Frequency of diabetic retinopathy and associated factors in Puerto Montt, Chile

BACKGROUND: Diabetic retinopathy (DR) is an important cause of decreased visual acuity, whose prevalence has increased between 1990 and 2020. In Chile the prevalence of diabetic retinopathy was estimated at 24.8%. AIM: To assess the prevalence of DR in a southern Chilean city. MATERIAL AND METHODS: From a database of diabetic patients attending primary health care centers at Puerto Montt, Chile, 196 patients with DR and 392 patients without DR, matched by age and presence of chronic complications, were chosen for this case-control study. RESULTS: The prevalence of DR in the database of diabetic patients was 33.3%. glycated hemoglobin, the frequency insulin use, systolic blood pressure, HDL cholesterol, microalbuminuria, and proteinuria were significantly worse in cases. A multivariate analysis showed that retinopathy is much more likely to occur when the variables insulin use, neuropathy, and microalbuminuria concur. CONCLUSIONS: DR was associated with worse metabolic parameters and the presence of neuropathy in this case control study.

Cancer immunotherapy without frontiers: 2nd Annual Immuno-Oncology Meeting of the Centro de Investigación de Cancer en Sonora (CICS), Ciudad Obregón, Sonora México, Dec 2-4, 2016.

This meeting in immuno-oncology brought together clinicians and scientists from United States, Canada, and México with the goal of breaking down international walls and establishing new collaborations.

The antigenic repertoire of premalignant and high-risk lesions.

Prophylactic vaccines have been a major advance in preventing the development of infections after exposure to pathogens. When contemplating an effective approach to cancer prevention, vaccines offer unique advantages over other more standard approaches: First, once appropriately stimulated, antigen-specific T cells will travel to all sites of disease and eradicate cells bearing the proteins to which the T cells have been primed by vaccination. Second, successful immunization will further result in the development of immunologic memory, providing lifelong immunologic surveillance. There is evidence of an adaptive tumor immune infiltrate even at the earliest stages of breast and colon cancer development. Furthermore, there is measurable immunity to lesion-associated antigens present in patients who will eventually develop malignancy even before cancer is clinically evident. Recent studies are beginning to unmask the preinvasive antigenic repertoire for these two malignancies. Preliminary experiments in transgenic mouse models of mammary and intestinal tumors suggest that immunization against antigens expressed in preinvasive and high-risk lesions may be effective in preventing the development of invasive malignancy.

Identification of putative immunologic targets for colon cancer prevention based on conserved gene upregulation from preinvasive to malignant lesions.

The length of time required for preinvasive adenoma to progress to carcinoma, the immunogenicity of colorectal cancer (CRC), and the identification of high-risk populations make development and testing of a prophylactic vaccine for the prevention of CRC possible. We hypothesized that genes upregulated in adenoma relative to normal tissue, which maintained increased expression in CRC, would encode proteins suitable as putative targets for immunoprevention. We evaluated existing adenoma and CRC microarray datasets and identified 160 genes that were ≥2-fold upregulated in both adenoma and CRC relative to normal colon tissue. We further identified 23 genes that showed protein overexpression in colon adenoma and CRC based on literature review. Silencing the most highly upregulated genes, CDH3, CLDN1, KRT23, and MMP7, in adenoma and CRC cell lines resulted in a significant decrease in viability (P < 0.0001) and proliferation (P < 0.0001) as compared to controls and an increase in cellular apoptosis (P < 0.05 for CDH3, KRT23). Results were duplicated across cell lines representing microsatellite instability, CpG island methylator, and chromosomal instability phenotypes, suggesting immunologic elimination of cells expressing these proteins could impact the progression of all CRC phenotypes. To determine whether these proteins were immunogens, we interrogated sera from early stage CRC patients and controls and found significantly elevated CDH3 (P = 0.006), KRT23 (P = 0.0007), and MMP7 (P < 0.0001) serum immunoglobulin G in cases as compared to controls. These data show a high throughput approach to the identification of biologically relevant putative immunologic targets for CRC and identified three candidates suitable for vaccine development.

Fibrocartilage tissue engineering: the role of the stress environment on cell morphology and matrix expression.

Although much is known about the effects of uniaxial mechanical loading on fibrocartilage development, the stress fields to which fibrocartilaginous regions are subjected to during development are mutiaxial. That fibrocartilage develops at tendon-to-bone attachments and in compressive regions of tendons is well established. However, the three-dimensional (3D) nature of the stresses needed for the development of fibrocartilage is not known. Here, we developed and applied an in vitro system to determine whether fibrocartilage can develop under a state of periodic hydrostatic tension in which only a single principal component of stress is compressive. This question is vital to efforts to mechanically guide morphogenesis and matrix expression in engineered tissue replacements. Mesenchymal stromal cells in a 3D culture were exposed to compressive and tensile stresses as a result of an external tensile hydrostatic stress field. The stress field was characterized through mechanical modeling. Tensile cyclic stresses promoted spindle-shaped cells, upregulation of scleraxis and type one collagen, and cell alignment with the direction of tension. Cells experiencing a single compressive stress component exhibited rounded cell morphology and random cell orientation. No difference in mRNA expression of the genes Sox9 and aggrecan was observed when comparing tensile and compressive regions unless the medium was supplemented with the chondrogenic factor transforming growth factor beta3. In that case, Sox9 was upregulated under static loading conditions and aggrecan was upregulated under cyclic loading conditions. In conclusion, the fibrous component of fibrocartilage could be generated using only mechanical cues, but generation of the cartilaginous component of fibrocartilage required biologic factors in addition to mechanical cues. These studies support the hypothesis that the 3D stress environment influences cell activity and gene expression in fibrocartilage development.

Predicción de sexo y de peso fetal mediante ecografía obstétrica / Prediction od fetal weight and sex by obstetric ultrasound

La ecografía obstétrica se ha posicionado como un apoyo importante al control prenatal, incluso por matronas y médicos generales que controlan pacientes en atención primaria. Sin embargo, la disponibilidad de ecografía realizada por médico obstetra en el sistema público es relativamente escasa, lo que ha llevado a médicos y matronas a capacitarse en ecografía obstétrica. El objetivo de este trabajo es evaluar la utilidad de realizar ecografías obstétricas de rutina en etapas posteriores al primer trimestre, basándose en la capacidad de predicción de peso y sexo fetales. Para ello, se revisaron 1.703 ecografías obstétricas realizadas en el Hospital de Calbuco entre los años 2005 y 2008. Los resultados muestran buena capacidad para predecir sexo fetal, no así en el caso del peso fetal, donde las diferencias entre los pesos estimados y reales superan los estándares aceptados. Estos datos nos pueden ayudar a dimensionar de mejor manera los alcances de las ecografías obstétricas que realizamos a nivel primario.

Obstetric ultrasound has emerged as an important support to prenatal care, including its use by midwives and general practitioners in primary health care. However, the availability of ultrasound performed by obstetric physician in the public health system is relatively low, which has led to the training of general doctors and midwives in obstetric ultrasound. The objective of this study is to evaluate the usefulness of routine obstetric ultrasound after the first trimester, based on its predictability of fetal weight and sex. With this aim, 1703 obstetric ultrasounds performed in Calbuco Hospital between 2005 and 2008 were reviewed. The results show good capacity of predicting fetal sex, but not in the case of fetal weight, where the differences between estimated and actual weights exceed accepted standards. This data can help us to better dimension the scope of obstetric ultrasound performed at the primary health level.

High-throughput measurements of hydrogel tissue construct mechanics.

Engineered tissues represent a natural environment for studying cell physiology, mechanics, and function. Cellular interactions with the extracellular matrix proteins are important determinants of cell physiology and tissue mechanics. Dysregulation of these parameters can result in diseases such as cardiac fibrosis and atherosclerosis. In this report we present a novel system to produce hydrogel tissue constructs (HTCs) and to characterize their mechanical properties. HTCs are grown in custom chambers and a robotic system is used to indent them and measure the resulting forces. Force measurements are then used to estimate HTC pretension (cellular contractility). Pretension was reduced in a dose-dependent manner by cytochalasin D (CD) treatment; the highest concentration (2microM) resulted in 10-fold decrease. On the other hand, treatment with fetal bovine serum (20%) resulted in approximately threefold increase in pretension. Excellent repeatability and precision were observed in measurements from replicate HTCs. The coefficient of statistical variance of quantified pretension ranged from 7% to 15% (n=4). Due to the small size (4x4x0.8mm) of the HTCs, this system of profiling HTC mechanics can readily be used in high-throughput applications. In particular, it can be used for screening chemical libraries in search of drugs that can alter tissue mechanics.

Inhibition of glycogen synthase kinase 3beta during heart failure is protective.

Glycogen synthase kinase (GSK)-3, a negative regulator of cardiac hypertrophy, is inactivated in failing hearts. To examine the histopathological and functional consequence of the persistent inhibition of GSK-3beta in the heart in vivo, we generated transgenic mice with cardiac-specific overexpression of dominant negative GSK-3beta (Tg-GSK-3beta-DN) and tetracycline-regulatable wild-type GSK-3beta. GSK-3beta-DN significantly reduced the kinase activity of endogenous GSK-3beta, inhibited phosphorylation of eukaryotic translation initiation factor 2B epsilon, and induced accumulation of beta-catenin and myeloid cell leukemia-1, confirming that GSK-3beta-DN acts as a dominant negative in vivo. Tg-GSK-3beta-DN exhibited concentric hypertrophy at baseline, accompanied by upregulation of the alpha-myosin heavy chain gene and increases in cardiac function, as evidenced by a significantly greater Emax after dobutamine infusion and percentage of contraction in isolated cardiac myocytes, indicating that inhibition of GSK-3beta induces well-compensated hypertrophy. Although transverse aortic constriction induced a similar increase in hypertrophy in both Tg-GSK-3beta-DN and nontransgenic mice, Tg-GSK-3beta-DN exhibited better left ventricular function and less fibrosis and apoptosis than nontransgenic mice. Induction of the GSK-3beta transgene in tetracycline-regulatable wild-type GSK-3beta mice induced left ventricular dysfunction and premature death, accompanied by increases in apoptosis and fibrosis. Overexpression of GSK-3beta-DN in cardiac myocytes inhibited tumor necrosis factor-alpha-induced apoptosis, and the antiapoptotic effect of GSK-3beta-DN was abrogated in the absence of myeloid cell leukemia-1. These results suggest that persistent inhibition of GSK-3beta induces compensatory hypertrophy, inhibits apoptosis and fibrosis, and increases cardiac contractility and that the antiapoptotic effect of GSK-3beta inhibition is mediated by myeloid cell leukemia-1. Thus, downregulation of GSK-3beta during heart failure could be compensatory.