Genetic diversity and genetic structure of Puya raimondii (Bromeliaceae) for its conservation in the Peruvian Andes

Resumen Puya raimondii es una especie endémica de los altos Andes de Perú y Bolivia. En el Perú se distribuye desde 8.068501°S, 16.170280°W hasta 16.180580° S, 70.658873° W, entre los 3600 y 4800 m de altitud, viviendo en condiciones climáticas extremas propias de la Puna, donde juega un papel ecológico importante. Pese a la amplia distribución de las poblaciones de P. raimondii en el Perú, aparentemente son bastante uniformes morfológicamente; por lo que surgen las siguientes preguntas: ¿Podrán las actuales herramientas moleculares mostrar diferencias entre las numerosas poblaciones? ¿Son suficientes las áreas de conservación establecidas para P. raimondii ya que albergan la variabilidad existente? Para responder a estas interrogantes, este trabajo tuvo como objetivo evaluar la diversidad genética y estructura genética en una población del norte del país, Pachapaqui (departamento de Ancash), una población del centro, Yanacancha (Junín), y una población del sur, Lampa - sector Choconchaca (Puno), utilizando marcadores microsatélites (SSR) específicos para la especie. Los parámetros de diversidad genética utilizados incluyeron número de alelos (A), alelos exclusivos (RA), heterocigosidad observada (Ho), heterocigosidad esperada (He) e índice de contenido polimórfico (PIC). Los resultados mostraron que el número total de A varió de 2 ‒ 13, los valores de He fueron 0 ‒ 0.723 y Ho 0 ‒ 0.929, con un He promedio de 0.217, indicando una diversidad genética moderada a alta, siendo la población de Lampa-sector Choconchaca, la que presentó mayor diversidad alélica y mayor diversidad genética. La prueba de Hardy-Weinberg mostró que las poblaciones se encuentran en desequilibrio HW, el análisis estadístico indica un 65% de variación genética a nivel poblacional y valores de FST (0.426) y RST (0.650) que indican alta diferenciación genética entre poblaciones, con dos grupos genéticos (K=2) que corresponden a las poblaciones del centro-norte y sur del Perú. Los resultados brindan información útil para establecer estrategias de conservación para P. raimondii, que conduzcan a la creación de una área de conservación adicional para proteger a las poblaciones del sur del Perú.

Abstract Puya raimondii is an endemic species from the high Andes of Peru and Bolivia. In Peru it is distributed from 8.068501°S, 16.170280°W to 16.180580°S, 70.658873°W, between 3600 and 4800 m, living in extreme climatic conditions typical of the Puna, where it plays an important ecological role. Despite the wide distribution of P. raimondii populations in Peru, they appear to be fairly uniform morphologically. The following questions arise: Will the current molecular tools be able to show differences between the numerous populations? Are the conservation areas established for P. raimondii sufficient since they harbor the existing variability? To answer these questions, this work aimed to evaluate the genetic diversity and genetic structure in a northern population, Pachapaqui (Ancash department), a central population, Yanacancha (Junin), and a southern population, Lampa - Choconchaca sector (Puno), using microsatellite markers (SSR) specific for the species. The genetic diversity parameters used included number of alleles (A), exclusive alleles (RA), observed heterozygosity (Ho), expected heterozygosity (He), and polymorphic content index (PIC). The results showed that the total number of A varied from 2 - 13, the He values were 0 ‒ 0.723 and Ho 0 ‒ 0.929, with an average He of 0.217, indicating a moderate to high genetic diversity, being the population of Lampa-Choconchaca sector, the one that presented the greatest allelic diversity and the greatest genetic diversity. The Hardy-Weinberg test showed that the populations are in HW disequilibrium, the statistical analysis indicates 65% of the genetic variation at the population level and values of FST (0.426) and RST (0.650) that indicate high genetic differentiation among populations, with two genetic groups (K=2) that correspond to the populations of northern-central and southern Peru. The results provide useful information to establish conservation strategies for P. raimondii, which lead to the creation of an additional conservation area to protect the populations in southern Peru.

Corrigendum to "Prevalence of APOL1 Risk Variants in Afro-Descendant Patients with Chronic Kidney Disease in a Latin American Country".

[This corrects the article DOI: 10.1155/2019/7076326.].

Prevalence of APOL1 Risk Variants in Afro-Descendant Patients with Chronic Kidney Disease in a Latin American Country.

INTRODUCTION: In Colombia, the genetic background of the populations was shaped by different levels of admixture between Natives, European, and Africans. Approximately 35.363 patients have diagnosed chronic kidney disease and according to population studies, 10.4% of these patients are Afro-descendant. We aim to assess the frequency of APOL1 variants G1 and G2 in Afro-descendant patients with ESRD treated at la Fundacion Valle del Lili University Hospital in Cali, Colombia. METHODS: This is an observational cross-sectional study. Afro-descendant patients with ESRD in waitlist or recipients of kidney transplant were evaluated. Clinical data were collected from the electronic medical records. Genotyping was carried out by amplification of the exon 7 of the APOL1 gene. For the identification of risk genotypes, the bioinformatics tool BLAST was used. RESULTS: We enrolled 102 participants. The frequency of APOL1 risk variants was 67.2%, in which 24.5% (n = 25) were G1 heterozygous and 5.8% (n = 6) were G2 heterozygous and 37% of the patients had high-risk status with two alleles in homozygous (G1/G1 = 21 and G2/G2 = 3) or compound heterozygote (G1/G2 = 14) form.

Aspergillus hepatic artery thrombosis in liver transplantation.

We present the first cirrhotic patient who underwent liver transplantation (LT) and presented a hepatic artery thrombosis of the graft due to Aspergillus fumigatus, within the first month of LT. This culminated in graft loss, re-transplant with multiple biliary and infectious complications. To our knowledge, this is a case report of an early hepatic artery thrombosis due to Aspergillus fumigatus in an infection-free patient.

Lysosomal Acid Lipase Deficiency, a Rare Pathology: The First Pediatric Patient Reported in Colombia.

BACKGROUND Lysosomal acid lipase deficiency is a rare genetic metabolic lipid storage disease, with a high morbidity, and mortality, in children and adults. It is characterized by a mutation in the LIPA gene that causes an alteration of lipid metabolism, resulting in deposits of cholesterol esters and triglycerides in organs such as the liver, blood vessels, and gastrointestinal tract. Lysosomal acid lipase deficiency is predominantly caused by the mutation c.894G>A, seen in approximately 50-70% of patients. Our objective is to report the first pediatric case of lysosomal acid lipase deficiency in a pediatric patient in Colombia. CASE REPORT The patient is a 14-year-old boy with isolated hepatomegaly since 6 years of age without a family history of dyslipidemia. In the pediatric control, laboratory exams revealed dyslipidemia, and a hepatic biopsy was performed, revealing severe fibrosis with septation and grade 3 microvesicular steatosis (>75%). He was referred to our center and was suspected to have lysosomal acid lipase deficiency. Enzymatic activity was measured, showing absent activity. Confirmatory diagnosis with genetic sequencing showed a pathological homozygous mutation of c.894G>A. CONCLUSIONS Lysosomal acid lipase deficiency can manifest as early- or late-onset, with variable and severe signs and symptoms. The late-onset form has a broad spectrum of manifestations with mild symptoms, leading to under-diagnosis, which increases the actual disease burden. Early diagnosis is essential to initiate enzyme replacement therapy, since the natural disease course can be changed. More studies should be conducted in Latin America to evaluate the prevalence of the disease.

[Invasive pulmonary aspergillosis in children with hepatic transplant: a survivor]. / Aspergilosis pulmonar invasora en pacientes pediátricos con trasplante hepático, a propósito de una sobreviviente.

INTRODUCTION: Mycotic infections due to Aspergillus spp, are the main mycotic associated infections in liver transplant patients, with mortality rates up to 90% of the cases. Almost 50% of patients will de velop an infection during the first months after transplantation, of which 10% are associated with op portunistic agents. OBJECTIVE: To describe the diagnosis and management of an Invasive Pulmonary Aspergillosis (IPA) episode in a liver transplant patient. CASE REPORT: 11-months-old patient with liver transplant due to a biliary atresia who developed severe pneumonia associated with mechanical ventilation. The bronchoalveolar lavage showed high levels of galactomannan and positive culture for Aspergillus fumigatus leading to an IPA diagnosis. This episode was treated with antifungal with a favorable outcome. CONCLUSION: The IPA is an opportunistic infection in liver transplant patients, with high mortality rates, that must be suspected in this group of patients since an early diagnosis and treatment reduce mortality.

Aspergilosis pulmonar invasora en pacientes pediátricos con trasplante hepático, a propósito de una sobreviviente / Invasive pulmonary aspergillosis in children with hepatic transplant: a survivor

INTRODUCCIÓN: Las infecciones por Aspergillus spp son la principal infección micótica por hongos en pacientes con trasplante hepático, con una mortalidad reportada de hasta un 90% de los casos. En los pacientes trasplantados de hígado se espera que hasta un 50% desarrollen un episodio infeccioso en sus primeros meses postrasplante, de los cuales un 10% se asocian con agentes oportunistas. OBJETIVO: Describir el diagnóstico y manejo de un episodio de Aspergilosis Pulmonar Invasora (API) en una paciente con un trasplante hepático CASO CLÍNICO: Paciente de 11 meses de vida, con trasplante hepático secundario a atresia de vías biliares. En el periodo post-trasplante inmediato evolucionó con una neumonía grave asociada a ventilación mecánica. El lavado broncoalveolar presentó niveles altos de galactomanano y cultivo positivo para Aspergillus fumigatus, diagnosticándose una API. Este episodio se trató con un esquema de antifúngico con un resultado clínico favorable. CONCLUSIÓN: La API es una infección oportunista en pacientes con trasplante hepático, que debe ser sospechada en este grupo de pacientes, ya que el diagnóstico y tratamiento oportuno impacta directamente en la resolución de la infección por Aspergillus fumigatus.

INTRODUCTION: Mycotic infections due to Aspergillus spp, are the main mycotic associated infections in liver transplant patients, with mortality rates up to 90% of the cases. Almost 50% of patients will de velop an infection during the first months after transplantation, of which 10% are associated with op portunistic agents. OBJECTIVE: To describe the diagnosis and management of an Invasive Pulmonary Aspergillosis (IPA) episode in a liver transplant patient. CASE-REPORT: 11-months-old patient with liver transplant due to a biliary atresia who developed severe pneumonia associated with mechanical ventilation. The bronchoalveolar lavage showed high levels of galactomannan and positive culture for Aspergillus fumigatus leading to an IPA diagnosis. This episode was treated with antifungal with a favorable outcome. CONCLUSION: The IPA is an opportunistic infection in liver transplant patients, with high mortality rates, that must be suspected in this group of patients since an early diagnosis and treatment reduce mortality.

Hepatitis A, cardiomyopathy, aplastic anemia, and acute liver failure: A devastating scenario.

Hepatitis A virus (HAV) causes an acute infection and is usually asymptomatic in children. When clinical manifestations appear, these include choluria, jaundice, and abdominal pain. Although infrequent, extra-hepatic manifestations related to HAV have been described, affecting the heart, bone marrow, blood vessels, and other tissues.A 10-year-old boy from a rural area presented with a 15-day history of malaise, fever, and jaundice; laboratory examinations were compatible with HAV infection. The patient turned encephalopathic and was remitted to our center, where laboratory examinations showed a medullary aplasia and fulminant hepatitis requiring a liver transplant that was performed 72 hours after admission. At 24 hours post transplant, the patient developed a cardiomyopathy secondary to HAV, and intravenous immunoglobulin was administered. The patient is still alive and attending his medical check-ups.Although rare, extra-hepatic manifestations of HAV infection have been described in 14% of cases. The groups of patients affected are usually aged and present with high bilirubin levels. Acquired aplastic anemia and myocarditis caused by HAV are uncommon, and its pathophysiology has not yet been elucidated.HAV infection is usually asymptomatic in children, although extra-hepatic manifestations can appear requiring early detection and management.

Eco-epidemiology of Chagas disease in an endemic area of Colombia: risk factor estimation, Trypanosoma cruzi characterization and identification of blood-meal sources in bugs.

The Sierra Nevada de Santa Marta (SNSM) is a mountainous area in Colombia that is highly endemic to Chagas disease. We explored some eco-epidemiological attributes involved in the Chagas disease transmission scenario in three Indigenous communities. An epidemiological survey was done, where parasite infection in reservoirs and insects, Trypanosoma cruzi genotyping, identification of blood-meal sources in intradomiciliary insects using the high-resolution melting technique, and some risk factors were evaluated. The results suggest that several dwelling conditions such as thatched palm roofs and mud walls carried the highest risk of finding intradomiciliary Rhodnius prolixus, which 56.41% were infected with T. cruzi and fed with human blood. Moreover, T. cruzi Ia was the most frequent haplotype found in insects. These results indicate the existence of a domestic T. cruzi transmission cycle that does not overlap with the sylvatic cycle, and highlight the need for efficient entomological control focused to this area.

Determinación del transporte peritoneal de fósforo como herramienta para el control del fósforo sérico / Determination of peritoneal phosphate transport as a tool for controlling serum phosphorus

Introducción: La hiperfosfatemia (fósforo sérico ≥ 5,5 mg/dl) es un factor independiente de mortalidad en la población en diálisis. Comparamos el transporte peritoneal de fósforo, creatinina y urea para demostrar diferencias y señalar la relevancia de estos parámetros en el control del fósforo sérico. Material y métodos: Se incluyeron 60 pacientes en diálisis peritoneal y se determinó el índice dializante/plasma de fósforo (D/P P) y creatinina (D/P Cr), el aclaramiento semanal de fósforo (AclP) y creatinina (AclCr), Kt/V de urea semanal y la excreción peritoneal de fósforo (ExP). Resultados: El D/P P fue superior en pacientes con normofosfatemia, comparados con los que presentaron hiperfosfatemia, 0,61 ± 0,13 frente a 0,54 ± 0,10 (p = 0,035). Se observó una adecuada correlación entre el D/P P y el D/P Cr, r = 0,90, p < 0,05, pero una pobre concordancia entre ambos, con un límite inferior de −0,17 (−0,24 a −0,09 IC 95 %) y límite superior de 0,47 (0,39-0,54 IC 95 %) para el D/P Cr respecto al D/P P. El AclP tuvo una adecuada correlación con el D/P P en pacientes con Kt/V ≥ 1,7 (r = 0,384, p = 0,04) y en anúricos (r = 0,392, p = 0,04), pero no con el D/P Cr. Hubo una pobre concordancia del AclCr respecto al AclP con límite inferior de -13,54 l/sem/1,73 m2 SC (-21,68 a -5,4 IC 95 %) y límite superior de 58,98 l/sem/1,73 m2 SC (50,84-67,12 IC 95 %). La ExP total se relacionó con el AclP (r = 0,643, p < 0,05), mientras que no lo hizo con el AclCr (r = 0,222, p = 0,23). Mediante el método CHAID se realizó un árbol de clasificación del transporte de fósforo con base en su D/P, obteniendo 5 nodos (≤ 0,5, 0,51-0,55, 0,56-0,66, 0,67-0,76, > 0,76), mostrando diferencias estadísticamente significativas entre nodos para niveles séricos de fósforo, AclP total y peritoneal, así como Kt/V de urea semanal. Conclusiones: Las mediciones de D/P P y AclP no concuerdan con las mediciones de D/P Cr y AclCr, respectivamente, por lo que su determinación es una herramienta clínica para el control del nivel de fósforo sérico (AU)

Background: Hyperphosphataemia (serum phosphorus ≥5.5mg/dl) is an independent mortality factor for the dialysis population. We compared phosphorus, creatinine and urea peritoneal transport to demonstrate differences and indicate the relevance of these parameters in the control of serum phosphorus. Material and method: We included 60 patients on peritoneal dialysis and determined the dialysate/plasma phosphorus (D/P P) and creatinine (D/P Cr) ratios, weekly creatinine clearance (CrCl) and phosphorus clearance (PCl), weekly Kt/V of urea, and peritoneal phosphorus excretion (PEx). Results: D/P P was higher in patients with normal phosphataemia, compared with those who were hyperphosphataemic 0.61±0.13 versus 0.54±0.10 (p=.035). We observed an adequate correlation between D/P P and D/P Cr, r=0.90, p<.05, but poor concordance between both, with a lower limit of -0.17 (-0.24 to -0.09 95% CI) and an upper limit of 0.47 (0.39-0.54 95% CI) for D/P Cr with respect to D/P P. PCl had an adequate correlation with D/P P in patients with a Kt/V ≥1.7 (r=0.384, p=.04) and in anuric patients (r=0.392, p=.04), but not with D/P Cr. There was poor concordance of the CrCl with respect to PCl with a lower limit of -13.54l/week/1.73m2 BSA (-21.68 to -5.4 95% CI) and an upper limit of 58.98l/week/1.73m2 BSA (50.84-67.12 95% CI). Total PEx was related to PCl (r=0.643, p<.05), while it was not related to CrCl (r=0.222, p=.23). Using the CHAID method, we created a classification tree for phosphorus transport based on its D/P, obtaining 5 nodes (≤0.5, 0.51-0.55, 0.56-0.66, 0.67-0.76, >0.76), with statistically significant differences between nodes for serum phosphorus, total and peritoneal PCl and weekly Kt/V of urea. Conclusions: D/P P and PCl are not concordant with D/P Cr and CrCl respectively and therefore their determination is a clinical tool to control serum phosphorus levels

Determination of peritoneal phosphate transport as a tool for controlling serum phosphorus.

BACKGROUND: Hyperphosphataemia (serum phosphorus ≥5.5mg/dl) is an independent mortality factor for the dialysis population. We compared phosphorus, creatinine and urea peritoneal transport to demonstrate differences and indicate the relevance of these parameters in the control of serum phosphorus. MATERIAL AND METHOD: We included 60 patients on peritoneal dialysis and determined the dialysate/plasma phosphorus (D/P P) and creatinine (D/P Cr) ratios, weekly creatinine clearance (CrCl) and phosphorus clearance (PCl), weekly Kt/V of urea, and peritoneal phosphorus excretion (PEx). RESULTS: D/P P was higher in patients with normal phosphataemia, compared with those who were hyperphosphataemic 0.61±0.13 versus 0.54±0.10 (p=.035). We observed an adequate correlation between D/P P and D/P Cr, r=0.90, p<.05, but poor concordance between both, with a lower limit of −0.17 (−0.24 to −0.09 95% CI) and an upper limit of 0.47 (0.39-0.54 95% CI) for D/P Cr with respect to D/P P. PCl had an adequate correlation with D/P P in patients with a Kt/V ≥1.7 (r=0.384, p=.04) and in anuric patients (r=0.392, p=.04), but not with D/P Cr. There was poor concordance of the CrCl with respect to PCl with a lower limit of −13.54l/week/1.73m2 BSA (−21.68 to −5.4 95% CI) and an upper limit of 58.98l/week/1.73m2 BSA (50.84-67.12 95% CI). Total PEx was related to PCl (r=0.643, p<.05), while it was not related to CrCl (r=0.222, p=.23). Using the CHAID method, we created a classification tree for phosphorus transport based on its D/P, obtaining 5 nodes (≤0.5, 0.51-0.55, 0.56-0.66, 0.67-0.76, >0.76), with statistically significant differences between nodes for serum phosphorus, total and peritoneal PCl and weekly Kt/V of urea. CONCLUSIONS: D/P P and PCl are not concordant with D/P Cr and CrCl respectively and therefore their determination is a clinical tool to control serum phosphorus levels.

GH3 tumor pituitary cell cytoskeleton and plasma membrane arrangement are determined by extracellular matrix proteins: implications on motility, proliferation and hormone secretion.

The extracellular matrix (ECM) influences different physiological and pathophysiological aspects of the cell. The ECM consists in a complex network of macromolecules with characteristic biochemical properties that allow cells to sense their environments inducing different signals and changing cell behavior. The purpose of the present study was to evaluate the participation of different ECM proteins in cell morphology and its implication on motility, proliferation and hormone secretion in GH3 cells, a tumor pituitary cell. GH3 cells were cultured with a defined medium on collagens I/III and IV, fibronectin and laminin. GH3 cells express α2 integrin subunit de novo. The cells responded to the ECM proteins with differentiated cell surface morphologies and membrane protrusions. A rounded shape with small membrane blebs, weak substrate adhesion and high motility was observed in cells on C I/III and fibronectin, while on C IV and laminin cells were viewed elongated and adhered. Differences on actin cytoskeleton, cytoskeletal-associated vinculin and phospho-MLC showed that ECM proteins determine the cytoskeleton organization. Cell proliferation showed dependency on the ECM protein, observing a higher rate in cells on collagen I/III. Prolactin secretion was higher in cells with small blebs, but an unchangeable response to EGF was obtained with the ECM proteins, suggesting is a consequence of cortical actin arrangement. We ascribe the functional differences of the GH3 cells to the cytoskeletal organization. Overall, the data showed that ECM plays a critical role in GH3 cells modulating different cellular comportment and evidenced the importance of the ECM composition of pituitary adenomas.

Asociación entre excreción peritoneal de proteínas, episodios de peritonitis y D/P de fósforo en pacientes en diálisis peritoneal / Association between peritoneal protein excretion, peritonitis and D/P phosphate, in patients on peritoneal dialysis

Introducción: Se ha observado una relación entre el aumento de la transferencia de solutos (aumento del D/P de creatinina) y la disminución de la ultrafiltración, el aumento de la mortalidad y el riesgo de fracaso de la técnica en pacientes en diálisis peritoneal (DP). Las altas tasas de transporte de solutos se asocian con una mayor excreción peritoneal de proteínas (EPP) y esto se ha relacionado con un mayor riesgo de peritonitis. Nuestro objetivo fue evaluar la posible asociación entre la EPP, el número de episodios de peritonitis y el D/P de fósforo. Material y métodos: Se realizó un estudió longitudinal de cohorte prospectivo en pacientes en DP, a los que se les midió el D/P de fósforo, la EPP, el número de episodios de peritonitis, parámetros de adecuación, así como diferentes variables clínicas y bioquímicas. Resultados: Se incluyeron 60 pacientes en programa de DP ambulatoria. Se encontró una correlación significativa positiva (r = 0,369; p = 0,005) entre el D/P de fósforo y la EPP, al igual que entre la EPP y el número de episodios de peritonitis (r = 0,65; p = 0,044). Finalmente, se encontró que a mayor EPP y a mayor D/P de fósforo, menor nivel sérico de albumina (r = -0,50, p = 0,001 y r = -0,621, p = 0,000, respectivamente). Conclusiones: La EPP se asocia significativamente con el número de episodios de peritonitis y el D/P de fósforo (AU)

Introduction: There is a relationship between increased transfer of solutes (increased D/P creatinine) and decreased ultrafiltration, increased mortality and risk of technique failure in peritoneal dialysis patients. High rates of solute transport are associated with increased peritoneal protein excretion (PPE) and this has been associated with an increased risk of peritonitis. Our objective was to evaluate the possible association between the PPE, the number of episodes of peritonitis and the D/P phosphate. Material and methods: A prospective longitudinal cohort study in PD patients. D/P phosphate, PPE, the number of episodes of peritonitis, as well as adequacy parameters and clinical and biochemical variables were measured. Results: We included 60 patients on ambulatory peritoneal dialysis. We found a significant positive correlation (r=.369, P=.005) between the D/P phosphate and PPE, as well as between the PPE and the number of episodes of peritonitis (r=.65, p=.044). Finally, we found that the higher PPE and D/P phosphate, the lower serum albumin was (r=-0.50, p=.001 and r=-0.621, p=.000, respectively). Conclusions: The EPP is significantly associated with the number of episodes of peritonitis and the D/P phosphate (AU)

Association between peritoneal protein excretion, peritonitis and D/P phosphate, in patients on peritoneal dialysis.

INTRODUCTION: There is a relationship between increased transfer of solutes (increased D/P creatinine) and decreased ultrafiltration, increased mortality and risk of technique failure in peritoneal dialysis patients. High rates of solute transport are associated with increased peritoneal protein excretion (PPE) and this has been associated with an increased risk of peritonitis. Our objective was to evaluate the possible association between the PPE, the number of episodes of peritonitis and the D/P phosphate. MATERIAL AND METHODS: A prospective longitudinal cohort study in PD patients. D/P phosphate, PPE, the number of episodes of peritonitis, as well as adequacy parameters and clinical and biochemical variables were measured. RESULTS: We included 60 patients on ambulatory peritoneal dialysis. We found a significant positive correlation (r=.369, P=.005) between the D/P phosphate and PPE, as well as between the PPE and the number of episodes of peritonitis (r=.65, p=.044). Finally, we found that the higher PPE and D/P phosphate, the lower serum albumin was (r=­0.50, p=.001 and r=­0.621, p=.000, respectively). CONCLUSIONS: PPE is significantly associated with the number of episodes of peritonitis and the D/P phosphate.

Advancing innovation in health care leadership: a collaborative experience.

The changing framework of today's health care system requires leaders to be increasingly innovative in how they approach their daily functions and responsibilities. Sustaining and advancing a level of innovation that already exists can be challenging for health care administrators with the demands of time and resource limitations. Using collaboration to bring new-age teaching and disciplines to front-line leadership, one hospital was able to reinvigorate a culture of innovation through multiple levels and disciplines of the organization. The Innovation Certification Course provided nursing leaders and other managers' an evidence-drive approach, new principles and useful strategies of innovative leadership and graduate program education.

CD38 induces differentiation of immature transitional 2 B lymphocytes in the spleen.

CD38 is a surface receptor able to induce activation, proliferation, and survival of human and mouse lymphocytes; this molecule is expressed on the surface of both mature and immature B cells. In this work, the function of CD38 in the maturation of murine B lymphocytes in the spleen was analyzed. The results showed that CD38 is highly expressed on Transitional 2 (T2) B lymphocytes with an intermediate expression on Transitional 1 (T1) and mature follicular B cells (M). Correlating with a high expression of CD38, T2 cells are also larger and more granular than T1 or M B cells. T2 cells also showed high levels of other molecules, which indicate an activated phenotype. CD38 crosslinking induced proliferation and maturation of T2 B lymphocytes; in contrast, T1 subset died by apoptosis. Finally, CD38 stimulation of T2 B lymphocytes obtained from Btk-, Lyn-, or Fyn-deficient mice showed a defective differentiation; similarly, drugs interfering with PI3K or ERK decreased the proliferation or differentiation of this subset. This suggests that these molecules participate in the CD38 signaling pathway. As a whole, the results indicate that CD38 plays an important role in the regulation of B-cell maturation in the spleen.

Litter dynamics in riverine mangrove forests in the Guayas River estuary, Ecuador.

The hypothesis that rates of litter turnover in mangroves are controlled by local geophysical processes such as tides has been studied at sites with mostly small tides (<1 m) and minor crab consumption of leaf litter. Our study describes litter dynamics of three riverine mangrove sites (M1, M2, M3), inhabited by the mangrove crab Ucides occidentalis, located in a macrotidal (>3 m) river-dominated tropical estuary in Ecuador (2.5°S latitude). There were statistical effects of site and depth on soil salinities, but all mean salinities were <17 g kg-1. Daily rates of leaf litter fall were higher in the rainy compared to the dry season, although no seasonal effects were observed for other components of litter fall. Annual total litter fall rates were significantly different among sites at 10.64, 6.47, and 7.87 Mg ha-1 year-1 for M1, M2, and M3, respectively. There were significant site (M3 > M2 > M1) and season (rainy > dry) effects on leaf degradation, and both effects were related to differences in the initial nitrogen content of senescent leaves. Mean leaf litter standing crop among the sites ranged from 1.53 to 9.18 g m-2, but amounts were strongly seasonal with peak values during September in both years of our study (no significant year effect) at all three sites. Leaf turnover rates based on leaf fall estimates and litter standing crop were 10- to 20-fold higher than estimated from rates of leaf degradation, indicating the significant effect of leaf transport by tides and crabs. Field experiments demonstrated that the mangrove crab can remove daily additions of leaf material within 1 h at all three sites, except during August-October, when the crab is inactive on the forest floor. Even though there is seasonally elevated leaf accumulation on the forest floor during this time, leaf turnover rates are much higher than expected based on leaf degradation, demonstrating the importance of tidal export. This is the first description of how crabs influence litter dynamics in the New World tropics, and results are similar to higher rates of crab transport of leaf litter in the Old World tropics. Even in riverine mangroves with high geophysical energies, patterns of litter dynamics can be influenced by ecological processes such as crab transport.