A novel technique for increasing skin oxygenation.

OBJECTIVE: To develop a novel technique for increasing skin oxygenation based on diffusion principles and Fick's laws of diffusion. METHODS: A device that allows the creation of an oxygen-depleted environment immediately to the skin while simultaneously allowing measurement of the transcutaneous oxygen tension (TcPo2) levels was created. This device forms an oxygen gradient from the capillary bed of the subcutaneous tissue, through the skin's semipermeable membrane, and toward the oxygen-depleted enclosed environment. A healthy adult subject was fitted with the device. Once baseline TcPo2 levels were recorded, the oxygen concentration within the device was lowered, and TcPo2 levels were monitored. Effects were also studied when subjects breathed 100% oxygen for 5 minutes. RESULTS: Oxygen levels in the device decreased in accordance with increases in skin TcPo2 levels measured within the device. CONCLUSIONS: The application of this technique results in an increase in oxygen concentration in the skin and subcutaneous tissue in healthy subjects with normal, well-perfused skin. Whether this novel technique produces an increase in the skin oxygenation of subjects with inappropriate tissue oxygenation and chronic wounds requires further study.

Temporal distribution of heavy metal concentrations in oysters Crassostrea rhizophorae from the central Venezuelan coast.

The oyster Crassostrea rhizophorae is a bivalve abundant in Venezuelan estuaries and consumed by local populations. No known values have been reported on trace metals in oysters from the central Venezuelan coast. We report the concentrations of Al, Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, Sr, V and Zn in the soft parts of C. rhizophorae, which were collected bimonthly between March 2008 and March 2009, at two sampling areas from the Central Venezuelan Coast: Buche estuary and Mochima estuary. Our results show that for each metal there is a similar temporal variation pattern. The concentrations of the heavy metals reported in this work are useful as reliable baselines and can be used for comparison in future environment studies. Concentrations in C. rhizophorae from the Buche estuary can be interpreted to be high on a global scale for Cd, Cu, Ni and Mn, indicating atypically raised bioavailabilities.

Efficacy and safety of Chlorella supplementation in adults with chronic hepatitis C virus infection.

AIM: To evaluate the safety and efficacy of Chlorella in 18 patients chronically infected with hepatitis C virus (HCV) genotype 1. METHODS: Eighteen adults with chronic infection by HCV genotype 1 received daily oral supplementation of Chlorella for 12 wk. Changes in the RNA levels of HCV, as well as those of aspartate aminotransferase (AST) and alanine aminotransferase (ALT) levels were evaluated following this treatment period. Paired t tests were conducted to compare the means of the different variables at the beginning and end of the study. Side effects and quality of life aspects were also compared between weeks 0 and 12 of the study period. RESULTS: A majority 84.61% of the patients had a significant decrease in their ALT levels from week 0 to week 12. Evaluation of side effects showed that Chlorella was well tolerated. Quality of life assessment showed that 76.9 of the participants reported an improvement in their energy levels and 46.1% reported an improvement in their perception of general health. Although 69.23% also showed a decrease in their AST levels, this was not statistically significant. Most patients that exhibited an improvement in their ALT and AST levels also showed a tendency toward a decreased HCV viral load. The HCV RNA levels showed a decrease in 69.23% of the patients, which along with changes in AST/ALT ratios from week 0 to week 12, these results were not statistically significant. CONCLUSION: Chlorella supplementation was well tolerated in patients with chronic HCV and associated with a significant decrease in ALT liver enzyme levels.

Interaction between immunoglobulin allotypes and NK receptor genes in diabetes post-hepatitis C virus infection.

Genetic interactions between natural killer (NK) cells immunoglobulin-like receptor (KIR) genes and immunoglobulin allotypes have been previously reported in type 2 diabetes mellitus (DM) patients. Puerto Rican Americans with a history of intravenous drug use who developed DM following HCV infection (n=32) were compared to individuals infected with HCV without diabetes (n=121) and to DM non-infected individuals (n=95). Subjects were genotyped for KIRs and immunoglobulin allotypes. We found interactions of immunoglobulin allotypes KM3/KM3 with NK inhibitory receptors 2DL3/2DL3, 2DL1 in the absence of 2DS4 associated with susceptibility to DM in HCV infected individuals. These data suggest the possibility that a subset of patients with HCV could have an immune-mediated component contributing to the development of DM.

La discriminación en el aprendizaje del cuidado / Discrimination in learning nursing care

Esta investigación tuvo por objeto comprender el fenómeno de la discriminación como parte del aprendizaje del cuidado en estudiantes de enfermería, vale decir, comprender de qué manera experimentan el fenómeno de escoger o priorizar a un individuo sobre otro al momento de dar cuidados. Investigación cualitativa, en la que los datos fueron recopilados mediante entrevistas semiestructuradas complementadas mediante el registro de notas de campo. Muestra intencionada compuesta por estudiantes de enfermería de una universidad del sur de Chile, quienes se encontraban cursando el tercer y cuarto año del plan de estudios, y que habían aprobado los cursos profesionales. Hecho esto, aplicamos el método de casos extremos en base al rendimiento académico como criterio principal. Con apoyo de la herramienta Atlas.ti, los datos acopiados fueron sistematizados y reducidos empleando como guía la Teoría Fundamentada en los datos, llegando a emerger cuatro categorías analíticas. Se concluye que los estudiantes realizan una discriminación en favor de sí mismos, fundamentalmente en base a la patología del sujeto de atención y a factores personales de éste, tales como rostro amable, apertura al diálogo, respuesta comunicativa, entre otros. Encontramos en ellos especial interés por las personas con patologías que les resultan interesantes, conocidas, o bien, aquéllas en las que se presagia una estadía suficientemente larga como para participar de la evolución y evaluar los resultados de un plan de cuidados. Estos elementos surgieron como determinantes en las emociones que producen en los aprendices, instándoles a dedicar un mejor cuidado a unas personas que a otras.

The purpose of the research was to understand the phenomenon of "discrimination" as a part of nursing students learning how to provide nursing care, that is, how students make decisions and prioritize nursing care. Using a qualitative research methodology data collection included the use of semi-structured interviews and field notes. The sample was made up of nursing students enrolled in a nursing program in a university in southern Chile. The students had acquired specific clinical skills and were in the third and fourth years of study. The extreme-case method was used based on students' academic scores as mean criterion. Data were analyzed using the Atlas. ti tool followed by application of Grounded Theory techniques to identify four analytical categories. Results showed that nursing students were able to discriminate for themselves, based mainly on criteria about disease and personal factors, such as the attractiveness of a person's face, openness to dialog, level of communication and so on. Findings showed that students paid special attention to people with 'interesting' diseases, known diseases, or health problems which offered students the opportunity to implement nursing care plans and to assess outcomes. These elements emerged like determinant factors based on the emotions that they produce in the beginning students, triggering them to give better care to some individuals over others.

Protective KIR-HLA interactions for HCV infection in intravenous drug users.

Intravenous drug use has become the principal route of hepatitis C virus (HCV) transmission due to the sharing of infected needles. In this study, we analyzed the distribution of HLA-KIR genotypes among 160 Puerto Rican intravenous drug users (IDUs) with HCV infection and 92 HCV-negative Puerto Rican IDUs. We found a significant association between the presence of different combinations of KIR inhibitory receptor genes (KIR2DL2 and/or KIR2DL3, pC=0.01, OR=0.07; KIR2DL2 and/or KIR2DL3+KIR2DS4, pC=0.01, OR=0.39) and HLA-C1 homozygous genotypes (HLA-C1+KIR2DS4, pC=0.02, OR=0.43; HLA-C1+KIR2DL2+KIR2DS4, pC=0.02, OR=0.40) together with the activating receptor KIR2DS4 (HLA-C1+KIR2DS4+KIR2DL3 and/or KIR2DL2, pC=0.004, OR=0.38) with protection from HCV infection. Our findings in HCV-infected and non-infected IDUs suggest an important role for KIRs (KIR2DL2 and KIR2DL3) with group HLA-C1 molecules, in the presence of activating KIR2DS4, in protection from HCV infection. These results support the hypothesis that activator signaling, mediated by KIR2DS4, plays a determinant role in the regulation of NK cell antiviral-activity.

Genetic interactions of KIR and G1M immunoglobulin allotypes differ in obese from non-obese individuals with type 2 diabetes.

We analyzed the natural killer cell immunoglobulin-like receptor (KIR) genes and immunoglobulin allotypes in the development of type 2 diabetes (T2D) based on body mass index (BMI) measurements (obese vs. non-obese) in Puerto Rican Americans. Genetic interactions between the KIR haplotype A homozygotes (HAH) and its fraction containing two inhibitory receptors 2DL3 and 2DL1 and the activating receptor 2DS4 with immunoglobulin allotypes were studied. We found a significant association between the HAH and T2D (p=0.002; OR=7.97) and its interaction with the immunoglobulin allotype z: GM f/f (-) (p=<0.0001; OR, not determined) only in non-obese individuals. This association were due to the interactions between the 2DL3/2DL3, 2DL1/2DL1, and 2DS4 fragment with GM f/f (-) in T2D patients (p=0.0017; OR=3.45). Analysis based on BMI demonstrated associations in both obese (p=0.037; OR=2.43; 95% CI=0.97-6.31) and non-obese individuals (p=<0.0001; OR=8.38; 95% CI=2.49-29.31). By contrast, the interaction of the GM allotype f/f (-) with the HAH fragment was associated with T2D only in non-obese individuals (p=<0.0001; OR=18.2; 95% CI=3.71-113.4). As expected, interaction of both HAH and its fragment with HLA-C group's ligands were significant. We used informative short tandem repeats (STRs) that distinguish major populations to determine genetic admixture and found that there was no genetic stratification in our cohort. Our findings are consistent with the possibility of an autoimmune and/or innateimmune component in the pathogenesis of T2D: NK receptors with chronic inflammation in obese and genetic interactions with G1M allotype in T2D non-obese possibly mediating autoimmunity.

Interaction of NK inhibitory receptor genes with HLA-C and MHC class II alleles in Hepatitis C virus infection outcome.

Natural killer cells are important in innate defense against viral infections. The interplay between stimulatory and inhibitory natural killer cell receptors and their corresponding human leukocyte antigen ligands are known to influence the outcome of acute Hepatitis C virus infection. Frequencies of NK receptor genes (8 inhibitory, 6 activating and 2 pseudogenes) and HLA class II alleles (DRB1, DQB1) were analyzed in 160 Puerto-Rican American drug users with Hepatitis C virus infection; 121 had chronic viremia (CV) and 39 were spontaneous clearance (SC). We further ruled out genetic stratification using short tandem repeats. Interaction between KIR gene receptor 2DL3/2DL3 and its ligand, C1/C1 of HLA-Cw alleles and spontaneous clearance was confirmed (p=0.03, OR=3.05). We also found a new interaction between the KIR receptor gene 2DL3 with HLA-DRB1*1201 (p=0.0001, OR=22) associated with SC, and an association of HLA DQB1*0501 (p=0.05, OR=0.30) with CV. Our findings suggested a role for MHC class II alleles in Hepatitis C virus peptide presentation to T cells together with NK ligand interaction involving pathways that will be useful for the development of immunotherapeutic interventions.

Interaction of KIR genes and G1M immunoglobulin allotypes confer susceptibility to type 2 diabetes in Puerto Rican Americans.

The susceptibility to type 2 diabetes (T2D) involves genetic factors. We studied the distribution of KIR and MHC class I ligands phenotype and genotype frequencies, as well as immunoglobulin KM and GM allotype frequencies in a group of patients (N = 95) with T2D and ethnically matched healthy controls (N = 74) with Puerto Rican ethnic background. We found a slight increase of the 2DL3/2DL3 homozygous genotype in T2D. Moreover, the association between 2DL3/2DL3 genotype was significant in the presence of 2DS4 (pC = 0.01). Also, we observed an epistatic effect of the interaction of 2DL3/2DL3, 2DS4 with allele z of G1M in T2D (pC = 0.004, OR = 3.60, 95% CI, 1.62-8.10). This genetic interaction between KIR and G1M allotypes, associated with T2D, was also significant by multiple logistic regression analysis (p < 0.0001, OR = 4.90, 95% CI, 2.12-11.3). We did not detect population stratification using unlinked short tandem repeat (STR) markers, demonstrating that the patients and controls were ethnically matched. Hence, we have demonstrated in this study an epistatic interaction between KIR genes and the G1M allotype that influences the susceptibility to T2D in Puerto Rican Americans. Our findings are important for understanding the autoimmune or innate immune inflammatory-mediated mechanisms involved in the pathogenesis of T2D.

MHC class II genes in HCV viral clearance of hepatitis C infected Hispanic patients.

The frequency of class II human leukocyte antigen (HLA) alleles in 112 infected patients of Hispanic ancestry with serology positive for hepatitis C virus (HCV) was investigated. Our studies failed to demonstrate significant association between class II HLA alleles and the outcome of HCV infection: chronic viremia versus spontaneous viral clearance. Our results suggest that the genes responsible for the outcome are unknown, so far, and those HLA associations reported in several ethnic groups may represent genetic markers in nonrandom association with the responsible genes involved in determining viral clearance or chronic viremia following HCV infection.