Antibacterial Activity Analysis of Hydroxyapatite Based Materials with Fluorine and Silver / Análisis de la Actividad Antibacteriana de Materiales a Base de Hidroxiapatita con Flúor y Plata

ABSTRACT This investigation aims to evaluate the antibacterial activity of nanostructured hydroxyapatite based materials doped with silver and fluorine, to be used as a biomaterial with antibacterial activity. Four different formulations were prepared by combustion method: hydroxyapatite, hydroxyapatite-fluorine, hydroxyapatite-silver-fluorine and hydroxyapatite-silver, with 2% of the doping agents. X-ray diffraction technique was used to determine the mineralogy, identifying the presence of Ca5(PO4)3OH, Ca2P2O7, Ag3PO4, AgCa10(PO4)7 Ca5(PO4)3F and CaF2 phases for the studied samples. Scanning electron microscopy was used to study the morphological structure and it showed homogeneous crystallization of the hydroxyapatite and the inclusion of dopant agents. The antibacterial activity was determined using a modified inhibition test zone to observe if the bacteria (E. faecalis) was susceptible to the antimicrobial agent by the appearance of the zone of inhibition on the agar plate. Both the hydroxyapatite-silver and the hydroxyapatite-silver-fluorine materials generated an inhibition zone. It was possible to determine the minimum inhibitory concentration needed to kill most viable organisms after 48 hours of incubation using the broth microdilution method, resulting in 75 µg/ml and 200 µg/ml for the hydroxyapatite-silver and the hydroxyapatite-silver-fluorine formulation, respectively. These materials could be used for the development of new biomaterials that can be used in dental applications.

RESUMEN El objetivo de esta investigación es analizar la actividad antibacteriana de materiales nanoestructurados a base de hidroxiapatita con iones de flúor y plata que le confieran características particulares para que pueda ser utilizado como un biomaterial con actividad antimicrobiana. Se realizaron cuatro formulaciones distintas: hidroxiapatita, hidroxiapatita-flúor, hidroxiapatita-plata-flúor e hidroxiapatita-plata con un 2% de los agentes dopantes. La síntesis del material se realizó a través del método de combustión. La caracterización mineral se realizó a través de difracción de rayos X identificando las siguientes fases en las diversas formulaciones: Ca5(PO4)3OH, Ca2P2O7, Ag3PO4, AgCa10(PO4)7 Ca5(PO4)3F and CaF2. La estructura morfológica se analizó a través de microscopía electrónica de barrido que muestra la formación de estructuras compactas, presencia de cristales y la incrustación de flúor y plata. Se analizó la actividad antimicrobiana utilizando una prueba modificada para la observación del halo de inhibición, encontrándose solamente que los materiales que contenían plata-flúor y plata generaron dicho halo de inhibición. Por otra parte, usando la prueba de microdilución en pozo se encontró que la concentración mínima inhibitoria para el material de HA-Ag fue de 75 μg/ml y para el material de HA-Ag-F fue de 200 μg/ml, después de 48 horas de incubación utilizando E. faecalis.

Interactions Between the Nematode Heterorhabditis amazonensis JPM4 and the Predator Macrolophus basicornis: Two Natural Enemies of Tuta absoluta Native to South America.

Entomopathogenic nematodes (EPNs) and predatory mirids are among the most effective natural enemies for the control of Tuta absoluta, a key pest of tomato worldwide. In the case of South America, the native EPN Heterorhabditis amazonensis and the predator Macrolophus basicornis (Stal) coexist in tomato. The intraguild interactions of two ENPs, H. amazonensis JPM4 and the widely used Steinernema carpocapsae, with the predator M. basicornis, were studied in laboratory setups with the objective of evaluating the potential interactions between them. We hypothesized that the two natural enemies do not interact negatively. The first nymphal stage of the predator was not affected when exposed to tomato leaves directly sprayed with both EPNs, which we attributed to the small size of its stylet. Individuals treated with H. amazonensis JPM4 had low mortality rates in all developmental stages with a maximum of 1.3%. Mortality was higher when the predator was exposed to S. carpocapsae (28% for adults) and correlated positively with increasing developmental stages. In prey choice tests between larvae infected with H. amazonensis and uninfected larvae, M. basicornis fed indistinctively showing no clear preference. When presented with choice larvae infected with S. carpocapsae, the consumption of healthy larvae was higher. In a no-choice prey acceptance experiment, M. basicornis preyed on both healthy and infected larvae with no difference in larvae consumed. Predators that had fed from infected larvae did not exhibit signs of nematode infection and survived. Our results indicate that the South American native H. amazonensis JPM4 and M. basicornis do not show a negative interaction and are promising candidates for combined use in T. absoluta biological control.

Detection of hydroquinone by Raman spectroscopy in patients with melasma before and after treatment.

BACKGROUND: Melasma is an acquired, facial hyperpigmentation without a specific origin. It is regularly associated with multiple etiologic factors such as pregnancy, genetic, racial, and from estrogen administration. Among the methods to treat skin hyperpigmentation a series of skin bleaching agents have been used. At present, the most commonly used agent is known as hydroquinone. Nowadays, it is known that hydroquinone can cause cancer in animals with unknown relevance to humans. MATERIAL AND METHODS: In this work, Raman spectroscopy was used to observe the presence of hydroquinone in the skin of 18 patients who have been under treatment for melasma. RESULTS: A significant increase in the Raman signal was observed in the six bands associated with hydroquinone after melasma treatment. CONCLUSION: The authors believe that monitoring the presence of hydroquinone may be useful for an optimal personalized treatment of melasma and to provide the specialist a support tool to control the administration of this type of bleaching agents.

Factors related to inter-observer reproducibility of conventional Pap smear cytology: a multilevel analysis of smear and laboratory characteristics.

OBJECTIVE: To identify factors that influence the inter-observer reproducibility of the routine, conventional Pap smear cytology (Pap smear test) in a network of certificated laboratories in a middle-income Latin American country. METHODS: Twenty-six laboratories provided each an average of 26 negative for malignancy (NILM) and high-grade squamous intraepithelial lesion (HSIL) Pap smears. An external panel reviewed the slides. The kappa index and multilevel logistic regression were used to estimate the reproducibility and odds ratios (OR) of a false result with 95% confidence intervals (95% CI), respectively. Results are presented for laboratories that collect (collector laboratories) and do not collect (non-collector laboratories) samples. RESULTS: The agreements ranged widely (median kappa 0.51, range 0.16-0.70). The overall false-positive (FP) and false-negative (FN) rates were 31% (95% CI 27-35) and 11% (95% CI 7-17). Among collector laboratories (N = 14), a bigger sample collection volume decreased the probability of a FP (OR-adjusted 0.05, 95% CI 0.02-0.1) whereas the number of quality defects (OR-adjusted 1.67, 95% CI 1.25-2.24), high workload (OR-adjusted 5.52, 95% CI 3.85-7.92) and collection by cytotechnologists (OR-adjusted 1.28, 95% CI 1.15-1.42) or health professionals (OR-adjusted 2.26, 95% CI 2.04-2.49) instead of nursing assistants increased it. Among non-collector laboratories (N = 9), the FP rate increased with the number of quality defects (OR-adjusted 1.86, 95% CI 1.06-3.26) but decreased if the samples were collected by health professionals instead of nursing assistants (OR-adjusted 0.37, 95%CI 0.17-0.80). No significant associations were observed for FN. CONCLUSIONS: Staff in charge of cervical sampling significantly determined the reproducibility of the Pap smear test, but this depended on whether the laboratory collects samples or read samples collected elsewhere.

Continuous assessment of carotid intima-media thickness applied to estimate a volumetric compliance using B-mode ultrasound sequences.

Recent reports have shown that the carotid artery wall had significant movements not only in the radial but also in the longitudinal direction during the cardiac cycle. Accordingly, the idea that longitudinal elongations could be systematically neglected for compliance estimations became controversial. Assuming a dynamic change in vessel length, the standard measurement of cross-sectional compliance can be revised. In this work, we propose to estimate a volumetric compliance based on continuous measurements of carotid diameter and intima-media thickness (IMT) from B-mode ultrasound sequences. Assuming the principle of conservation of the mass of wall volume (compressibility equals zero), a temporal longitudinal elongation can be calculated to estimate a volumetric compliance. Moreover, elongations can also be estimated allowing small compressibility factors to model some wall leakage. The cross-sectional and the volumetric compliance were estimated in 45 healthy volunteers and 19 asymptomatic patients. The standard measurement underestimated the volumetric compliance by 25% for young volunteers (p < 0.01) and 17% for patients (p < 0.05). When compressibility factors different from zero were allowed, volunteers and patients reached values of 9% and 4%, respectively. We conclude that a simultaneous assessment of carotid diameter and IMT can be employed to estimate a volumetric compliance incorporating a longitudinal elongation. The cross-sectional compliance, that neglects the change in vessel length, underestimates the volumetric compliance.

Planar cell polarity effector gene Intu regulates cell fate-specific differentiation of keratinocytes through the primary cilia.

Genes involved in the planar cell polarity (PCP) signaling pathway are essential for a number of developmental processes in mammals, such as convergent extension and ciliogenesis. Tissue-specific PCP effector genes of the PCP signaling pathway are believed to mediate PCP signals in a tissue- and cell type-specific manner. However, how PCP signaling controls the morphogenesis of mammalian tissues remains unclear. In this study, we investigated the role of inturned (Intu), a tissue-specific PCP effector gene, during hair follicle formation in mice. Tissue-specific disruption of Intu in embryonic epidermis resulted in hair follicle morphogenesis arrest because of the failure of follicular keratinocyte to differentiate. Targeting Intu in the epidermis resulted in almost complete loss of primary cilia in epidermal and follicular keratinocytes, and a suppressed hedgehog signaling pathway. Surprisingly, the epidermal stratification and differentiation programs and barrier function were not affected. These results demonstrate that tissue-specific PCP effector genes of the PCP signaling pathway control the differentiation of keratinocytes through the primary cilia in a cell fate- and context-dependent manner, which may be critical in orchestrating the propagation and interpretation of polarity signals established by the core PCP components.

Beneficio de la rosuvastatina en el tratamiento de la hipertensión arterial y el remodelamiento ventricular / Beneficial effects of rosuvastatin in patients with arterial hypertension and ventricular remodeling

This paper describes the beneficial effects of rosuvastatin in patients with arterial hypertension in ventricular remodeling. As a conclusion, our data supports new evidence to encourage the use of statins for the treatment of cronic arterial hypertension and venticular remodeling

Expression of gp120 as surrogate marker in HIV infection / Expresión de gp120 como marcador de progresión en la infección por VIH

Ninety seven patients infected with HIV -1 were studied to evaluate the expression of gp120 in peripheral blood CD4+ T lymphocytes as a surrogate marker of disease progression, analyzing correlation of it with viral load, T cell subsets, expression of activation markers, HAAR T and clinical signs and symptoms. In patients who had not received any antiretroviral therapy (naive), expression of gp120 had a positive correlation with expression of CD95 in CD4+ T lymphocytes (p=0.0409) and a negative correlation with CD4+ T lymphocytes percentage (p=0.0183) and absolute values (p=0.0165), and with percentage of naüve CD4+ T cells (p=0.0126). In patients under highly active antiretroviral therapy (HAAR T) those correlations were not present. Expression of gp 120 had good correlations with some known surrogate markers of disease progression in naüve patients, but its low level of expression and the fact that those correlations disappear when HAAR T is initiated, limit the use of it as an independent surrogate marker.

Se estudiaron 97 pacientes infectados con VIH-1 para determinar gp120 en células TCD4+ de sangre periférica como un marcador de progresión de enfermedad y su correlación con carga viral, subpoblaciones de células T, marcadores de activación, terapia antiretroviral, síntomas y signos clínicos. En los pacientes quienes no habían recibido terapia antiretroviral (vírgenes), la expresión de gp120 tenía una correlación positiva con la expresión de CD95 en los linfocitos TCD4+: (p=0,0409) y una correlación negativa con el porcentaje de linfocitos TCD4+ (p=0,0183) con los valores absolutos (p=0.0165) y con el porcentaje de células TCD4+ vírgenes (p=0.0126). En los pacientes con alta terapia antiretroviral estas correlaciones no estaban presentes. La expresión de gp120 tuvo buena correlación con algunos marcadores de progresión de enfermedad en pacientes vírgenes, pero su bajo nivel de expresión y el hecho de que esta correlación desaparece cuando la terapia antiretroviral es iniciada, limita su uso como marcador independiente de progresión.

Evolution of endogenous hormone concentration in embryogenic cultures of carrot during early expression of somatic embryogenesis.

Embryogenic callus and suspension cultures of carrot (Daucus carota L., cv. Nantaise), growing on/in medium including 1 mg/l 2,4-dichlorophenoxy acetic acid (2,4-D), were transferred to medium with or without this plant growth regulator, to impair or induce, respectively, further development of somatic embryos. The endogenous hormone levels of the cultures were determined over 7 days by means of radio-immunoassay, to characterize their evolution in the initial stages of embryo development. In general, levels of indoleacetic acid (IAA) and abscisic acid (ABA) showed only short-lived differences among treatments during this time in both types of tissue analyzed (i.e., a peak of IAA in callus cultures in the absence of 2,4-D, 48 h after medium change, and higher ABA contents 144 h after subculture of suspension cultures in the presence of 2,4-D). Gibberellins (1, 3 and 20) were detected only in suspension cultures devoid of 2,4-D, starting 24 h after subculture. Concerning the evaluated cytokinins-zeatin/zeatin riboside and N6(Delta2-isopentenyl) adenine/N6(Delta2-isopentenyl) adenosine-the most remarkable observation is that high levels of the former generally coincided with low concentrations of the latter, indicating a shift from precursor to the active form, and vice versa.

Poroma: estudio clínico-patológico de 45 casos / Poroma: a clinico-pathologic study of 45 cases

Introducción. El poroma es un tumor benigno generalmente solitario cuya localización se considera más frecuente en palmas y plantas. Comprende un grupo histológico de cuatro tipos de poroma. Su origen parece descansar en las células pluripotenciales de la zona transicional entre los segmentos dérmico e intraepidérmico del ducto ecrino, aunque existen evidencias de diferenciación apocrina. Material y métodos. Estudio retrospectivo, transversal, descriptivo y observacional de los casos de poromas reunidos en 25 años en nuestro departamento, para conocer su epidemiología y características clínicas e histológicas. Se compara la información contenida en la literatura con nuestros resultados. Resultados. Los 45 poromas encontrados corresponden al 0.23 por ciento de todas las biopsias de nuestro departamento. Todos solitarios, la mayoría asintomáticos y más frecuentes en mujeres, se encontraron en pacientes de 10 a 83 años. Las piernas fueron la principal localización. La mayoría fueron del tipo histológico poroma ecrino, 17 tumores presentaban características de los otros tipos histológicos de poroma; tres presentaron diferenciación apocrina y uno, folicular. Conclusión. El poroma es un tumor benigno, raro, de predominio en mujeres, en la edad adulta media y cuya localización más frecuente fueron las piernas. De características clínicas inespecíficas, debe diferenciarse de otras neoplasias. El tipo histológico más frecuente es el poroma ecrino, las otras variedades se encuentran en asociación. Pueden presentar diferenciación apocrina y folicular. Pueden dar origen a porocarcinomas. Su extirpación completa es curativa (AU)

Receptores SUR y sulfonilureas en el tratamiento de la diabetes mellitus tipo 2 / Sulfonylureas and receptor SUR in the diabetes mellitus type 2 treatment

Las sulfonilureas son hipoglicemiantes orales usados en el tratamiento de la Diabetes Mellitus tipo 2, que actúan estimulando la secreción de insulina por parte de las células B del páncreas. Estudios recientes revelaron que éstos fármacos se unen a receptores específicos en la membrana celular de los islotes pancreáticos induciéndose el cierre de los canales de potasio sensibles a ATP, lo que provoca aumento en el contenido intracelular de potasio y despolarización de la célula conduciendo a la apertura de los canales de calcio voltaje dependiente entrando este al intracelular y liberándose insulina a partir de los gránulos maduros. Los canales de potasio sensibles a ATP están formados por la subunidad KIR6, 2 la cual forma el poro del canal y la subunidad receptora de sulfonilureas (SUR) que actúa como reguladora. Tres subtipos de receptores SUR han sido reconocidos hasta ahora: el tipo pancreático SUR1, cuya inhibición facilita la secreción de insulina; el tipo cardiaco SUR2A el cual suministra protección miocárdica y un tercer tipo en el músculo liso vascular SUR2B el cual juega un rol en la tonicidad vascular

Assessing culturally competent scholarship.

Cultural competence is a necessity for nursing practice in a global society, and use of objective criteria to measure cultural competence is a critical need. We used Meleis's eight criteria for assessing culturally competent scholarship as an analytical framework for reviewing an international educational/research experience. We developed operational measures for each criterion, then applied the measures to our experience, citing discrete examples for adherence. While we believe we have met the criteria for cultural competence in our course and scholarly work, our application has helped to identify areas needing improvement. In addition, we hope our application of these criteria will stimulate others to evaluate their own efforts in teaching, researching, or practicing cultural competence.

Effectors of inflammation in actinic prurigo.

BACKGROUND: Actinic prurigo is a specific familial photodermatosis of uncertain pathogenesis. OBJECTIVE: Our purpose was to investigate the immunohistologic presentation of actinic prurigo to explore the involved pathomechanisms. METHODS: The present immunohistochemical study was performed on biopsy specimens from 20 Mexican patients presenting with a severe and perennial form of the disease. RESULTS: The dense inflammatory infiltrate was composed predominantly of helper T type 1 lymphocytes admixed with scattered B-cell lymphoid follicles and numerous dermal dendrocytes. Keratinocytes contained abundant tumor necrosis factor-alpha and calprotectin. CONCLUSION: In subjects genetically predisposed to actinic prurigo, ultraviolet light may trigger excessive tumor necrosis factor-alpha production by keratinocytes whose sustained release in turn exerts its proinflammatory activity and deleterious epidermal effects. Such a cascade of events is in line with the therapeutic benefit already reported when thalidomide is used to treat actinic prurigo.

Endogenous hormone levels in habituated nucellar Citrus callus during the initial stages of regeneration.

Embryogenic nucellar callus cultures of different Citrus species and cultivars growing in hormone-free medium were transferred to medium containing either sucrose or glycerol as the only carbohydrate source. Glycerol has been reported to induce further development of Citrus somatic embryos, while in the presence of sucrose they continue to proliferate in an 'undifferentiated' manner. The endogenous hormone levels of the cultures were evaluated after 2 and 5 days to characterise the initial steps of embryo development. In most cases, differences among treatments were observed only after 5 days of culture. Higher cytokinin levels were found in most of the cultures transferred to the glycerol-containing medium. The effect of ageing sweet orange cultures on their endogenous hormone levels was determined by leaving them in the original culture medium without subculturing for 60 days. While no changes were observed in the free indoleacetic acid and gibberellin contents, lower levels of abscisic acid and cytokinins were found in the aged cultures than in those transferred at the normal interval, every 30 days. The endogenous hormone contents of Citrus callus of different genotypes were compared. Significant differences were observed in the levels of all hormones evaluated, even when the in vitro ontogeny of the different genotypes was very similar.

Women's self-perception and self-care practice: implications for health care delivery.

Mexican American women experience unique health care needs related to integration of Mexican and American cultures. To learn how to better promote self-care practices and service utilization in women of Mexican origin living in Texas, researchers used a qualitative approach to interview a convenience sample of 11 low-income women attending a health clinic. Researchers collected narrative data about the women's perceptions of health, wellness, and self-care. Using the matrix approach described by Miles and Huberman, we organized findings around women's roles, including participants' descriptions of themselves, their health and wellness awareness, self-care practices for health/illness and wellness/nonwellness, barriers to self-care, origin of self-care practices, and perceptions of life control. Implications for health planning and service delivery are presented.

Leishmaniasis en el Ecuador: diagnóstico de la leishmaniasis cutánea con la reacción en cadena de la polimerasa (PCR) en comparación con las técnicas convencionales / Leishmaniasis in Ecuador: diagnosis of the cutaneous leishmaniasis with relation in chain of the polymerase (PCR) in comparison with the conventional techniques

En este estudio se evaluó el diagnóstico de la leishmaniasis cutánea por el laboratorio mediante la técnica de la Reacción en Cadena de la Polimerasa (PCR) en comparación con los métodos actualmente recomendados: examen microscópico en frotis, cultivo en medio específico e histopatología en biopsia. El estudio se realizó en 72 individuos con lesiones cutáneas sospechosas de infección por Leishmania spp., procedentes del cnatón El Carmen, provincia de Manabí, Ecuador. La PCR, con oligonucleótidos específicos para el complejo braziliensis fue más sensitiva (90.9 por ciento) que cualquiera de los otros 3 métodos empleados. el cultivo en medio Novy-MacNeal-Nicolle (NNN), en el que 19 por ciento de muestras de desecharon por contaminación bacteriana o micótica, alcanzó el 45.5 por ciento de sesitividad...