Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 19 de 19
Filtrar
1.
Biochem Cell Biol ; 101(6): 538-549, 2023 12 01.
Artículo en Inglés | MEDLINE | ID: mdl-37586108

RESUMEN

Here, a machine learning tool (YOLOv5) enables the detection of Cryptosporidium microorganisms using optical and phase contrast microscope images. The two databases were processed using 520 images (optical microscopy) and 1200 images (phase contrast microscopy). It used Python libraries to label, standardize the size, and crop the images to generate the input tensors to the YOLOv5 network (s, m, and l). It implemented two experiments using randomly initialized weights in optical and phase contrast microscope images. The other two experiments used the parameters for the best training time obtained before and after retraining the models. Metrics used to assess model accuracy were mean average accuracy, confusion matrix, and the F1 scores. All three metrics confirmed that the optimal model used the best epoch of optical imaging training and retraining with phase contrast imaging. Experiments with randomly initialized weights with optical imaging showed the lowest precision for Cryptosporidium detection. The most stable model was YOLOv5m, with the best results in all categories. However, the differences between all models are lower than 2%, and YOLOv5s is the best option for Cryptosporidium detection considering the differences in computational costs of the models.


Asunto(s)
Criptosporidiosis , Cryptosporidium , Humanos , Criptosporidiosis/diagnóstico por imagen , Microscopía , Imagen Óptica
2.
Polymers (Basel) ; 14(9)2022 Apr 29.
Artículo en Inglés | MEDLINE | ID: mdl-35567004

RESUMEN

New data of creep and viscoelastic Poisson's ratio, ν(t), of five engineering elastomers (Ethylene Propylene-Diene Monomer, Flouroelastomer (Viton®), nitrile butadiene rubber, silicone rubber and neoprene/chloroprene rubber) at different stress (200, 400 and 600 kPa) and temperature (25, 50 and 80 °C) are presented. The ν(t) was characterized through an experimental methodological approach based on creep testing (30 min) and strain (axial and transverse) measurements by digital image correlation. Initially, creep behavior in axial and transverse directions was characterized for each elastomer and condition, and then each creep curve was fitted to a four-element creep model to obtain the corresponding functions. The obtained functions were used to estimate ν(t) for prolonged times (300 h) through a convolution equation. Overall, the characterization was achieved for the five elastomers results exhibiting ν(t) increasing with temperature and time from about 0.3 (for short-term loading) to reach and stabilize at about 0.48 (for long-term loading).

3.
MethodsX ; 9: 101703, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35492216

RESUMEN

Micro-abrasion is a kind of wear occurring on materials´ surfaces by action of three-body hard particles existing at the sliding interface. It is consistently reproduced by a popular laboratory method well-known as ball cratering test. Characteristically, it consists of wearing off a material sample by loading it against a ball that rotates continuously and unidirectionally under controlled conditions. A slurry containing a certain amount of hard micro-sized particles is dropped uninterruptedly onto the ball to get the particles enters the sliding contact by the ball´s rotary effect. The present method proposes a variant to the classic micro-abrasion methodology. It comprises changing the ball motion from a unidirectional to an oscillating for testing by considering new test parameters such as sliding arc lengths and frequency, which provides more realistic sliding conditions and wear rates for materials to be used in mechanical applications involving reciprocating and oscillating sliding.

4.
Acta méd. peru ; 39(2): 104-113, abr.-jun. 2022. tab, graf
Artículo en Español | LILACS-Express | LILACS | ID: biblio-1402997

RESUMEN

RESUMEN Objetivo: Identificar características demográficas, clínicas, laboratoriales y de tratamiento asociados a la mortalidad en pacientes hospitalizados con neumonía por SARS-CoV-2 en un Hospital I del Seguro Social del Perú de la Red La Libertad. Materiales y Método : Estudio de cohorte retrospectiva. Se utilizó el modelo de riesgos proporcionales de Cox calculándose los cocientes de riesgo instantáneos (HR) crudos y ajustados, y el estimador de Kaplan-Meier para evaluar la curva de supervivencia general y con cada factor. Resultados : De los 158 pacientes se confirmó el diagnóstico en 79,11 %. El 68,99 % fueron hombres, la mediana de la edad global fue de 65 años (RIC:52-77), siendo mayor en los fallecidos con 69 años (RIC:61-80 años). El 53,80 % tenían comorbilidad, siendo estas la HTA (27,85 %), obesidad (22,78 %) y diabetes mellitus (13,92 %). La mediana de duración de síntomas previo al ingreso fue de 9 días (RIC:6-11 días). Se determinó los HR para la saturación de oxígeno menor de 80 % a su ingreso a un FIO2 del 0,21, la leucocitosis con linfopenia asociada, el requerimiento de oxígeno a un FIO2 del 0,80 a su ingreso y el SDRA moderado-severo, los cuales fueron de 1.54, 1.98, 2.07 y 2.91, respectivamente. Conclusiones: El desarrollo de un SDRA moderado-severo a su ingreso, la leucocitosis asociada con linfopenia, la hipoxemia de ingreso menor a 80 % a un FIO2 del 0,21, y el requerimiento de oxígeno a alto flujo desde su ingreso con un FIO2 del 0,80, fueron los únicos factores de riesgo de mortalidad encontrados.


ABSTRACT Objective: To identify demographic, clinical, laboratory and treatment characteristics associated with mortality in hospitalized patients with SARS-CoV-2 pneumonia in a Level I Hospital of Peruvian Social Security, at La Libertad Network. Materials and Method : Retrospective cohort study. Cox proportional hazards model was used, calculating crude and adjusted hazard ratios (HR), and the Kaplan-Meier estimator was used to evaluate the overall survival curve and for each factor. Results : Of the 158 patients, the diagnosis was confirmed in 79.11%. Nearly 70% (68.99%) were men, the global median age was 65 years (IQR: 52-77), and it was higher in deceased subjects 69 years old (IQR: 61-80 years). Little more than half of this population (53.80%) had comorbidities, such as high blood pressure (27.85%), obesity (22.78%), and diabetes mellitus (13.92%). The median duration of symptoms prior to admission was 9 days (IQR: 6-11 days). HRs were determined for oxygen saturation less than 80% on admission with 0.21 FIO2, leukocytosis with associated lymphopenia, oxygen requirement at 0.80 FIO2 on admission, and moderate-severe ARDS. Such values were 1.54, 1.98, 2.07 and 2.91, respectively. Conclusions : The development of moderate-severe ARDS on admission, leukocytosis associated with lymphopenia, less than 80% hypoxemia on admission at 0.21 FIO2, and high-flow oxygen requirement since admission with 0.80 FIO2, were the only risk factors for mortality.

5.
Inflamm Res ; 68(4): 261-274, 2019 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-30739130

RESUMEN

OBJECTIVE/DESIGN: In a double-blind, placebo-controlled, multiple-dose study, we assessed the molecular mechanism of action of the selective histamine-4-receptor antagonist toreforant. PATIENTS/TREATMENT: Patients with active rheumatoid arthritis (RA) despite methotrexate were randomized (3:1) to toreforant 30 mg/day (weeks 0-52) or placebo (weeks 0-12) followed by toreforant 30 mg/day (weeks 12-52). METHODS: Primary biomarker analyses comprised 39 different proteins/mRNA transcripts measured in synovial biopsy (n = 39) and/or time-matched serum (n = 15) samples collected at baseline and week 6. Clinical response was assessed using C-reactive protein-based 28-joint disease activity scores. Data were summarized using descriptive statistics. RESULTS: Among 21 randomized, treated patients (toreforant-16, placebo-5), 18 (toreforant-13, placebo-5) completed the 12-week double-blind period (none completed open-label treatment) prior to the early study termination. Biomarker profiling indicated potential modest effects of toreforant on gene expression of histamine-1-receptor, tumor necrosis factor-alpha, and interleukin-8 in synovium. Potential trends between biomarkers and clinical response were observed with synovial monocyte chemoattractant protein-4 and phosphorylated extracellular-signal-regulated kinases and serum matrix metalloproteinase-3. Minimal synovial gene expression of interleukins-17A and 17F was detected. CONCLUSIONS: While clear biomarker signals associated with toreforant pharmacology in RA patients were not identified, modest associations between biomarkers and clinical response were noted. Synovial expression of interleukins-17A/17F was minimal. Limited sample size warrants cautious interpretation.


Asunto(s)
Antirreumáticos/uso terapéutico , Artritis Reumatoide/tratamiento farmacológico , Bencimidazoles/uso terapéutico , Antagonistas de los Receptores Histamínicos/uso terapéutico , Piperidinas/uso terapéutico , Pirimidinas/uso terapéutico , Receptores Histamínicos H4/antagonistas & inhibidores , Adolescente , Adulto , Anciano , Antirreumáticos/farmacología , Artritis Reumatoide/inmunología , Artritis Reumatoide/patología , Bencimidazoles/farmacología , Método Doble Ciego , Femenino , Antagonistas de los Receptores Histamínicos/farmacología , Humanos , Interleucina-17/inmunología , Masculino , Metotrexato/farmacología , Metotrexato/uso terapéutico , Persona de Mediana Edad , Piperidinas/farmacología , Pirimidinas/farmacología , Membrana Sinovial/inmunología , Membrana Sinovial/patología , Resultado del Tratamiento , Adulto Joven
6.
Arthritis Rheumatol ; 71(2): 258-270, 2019 02.
Artículo en Inglés | MEDLINE | ID: mdl-30225992

RESUMEN

OBJECTIVE: To evaluate the efficacy and safety of ustekinumab in 3 randomized, placebo-controlled studies in patients with axial spondyloarthritis (SpA). Studies 1 and 2 included patients with radiographic axial SpA (anti-tumor necrosis factor [anti-TNF]-naive patients and patients with inadequate response or intolerance to anti-TNF, respectively); study 3 patients had nonradiographic axial SpA. METHODS: In all 3 studies, patients were randomly assigned (1:1:1) to receive subcutaneous ustekinumab at 45 mg or 90 mg or placebo up to 24 weeks, after which placebo-treated patients were rerandomized to receive ustekinumab at 45 mg or 90 mg. The primary end point in studies 1 and 2 was the proportion of patients who met the Assessment of SpondyloArthritis international Society criteria for 40% improvement in disease activity (achieved an ASAS40 response). The primary end point in study 3 was the proportion of patients who achieved an ASAS20 response. Other disease activity and safety measures were also evaluated. A week 24 analysis of study 1 was preplanned to determine continuation of studies 2 and 3. RESULTS: For study 1, the primary and major secondary end points were not met, and the study was discontinued. As a result, studies 2 and 3 were prematurely discontinued before they were fully enrolled. For all 3 studies, neither ustekinumab dose group demonstrated clinically meaningful improvement over placebo on key efficacy end points. The proportion of patients experiencing adverse events in the ustekinumab groups was consistent with that in previous studies. CONCLUSION: In these 3 placebo-controlled trials, efficacy of ustekinumab in the treatment of axial SpA was not demonstrated. The safety profile was consistent with that of studies in other indications.


Asunto(s)
Antirreumáticos/uso terapéutico , Espondilitis Anquilosante/tratamiento farmacológico , Ustekinumab/uso terapéutico , Adulto , Anticuerpos Monoclonales/uso terapéutico , Método Doble Ciego , Femenino , Humanos , Reacción en el Punto de Inyección/epidemiología , Masculino , Persona de Mediana Edad , Espondiloartropatías/diagnóstico por imagen , Espondiloartropatías/tratamiento farmacológico , Espondilitis Anquilosante/diagnóstico por imagen , Resultado del Tratamiento
7.
Nanotechnology ; 28(24): 245605, 2017 Jun 16.
Artículo en Inglés | MEDLINE | ID: mdl-28452330

RESUMEN

A straightforward method for the synthesis of CoFe2.7/CoFe2O4 core/shell nanowires is described. The proposed method starts with a conventional pulsed electrodeposition procedure on alumina nanoporous template. The obtained CoFe2.7 nanowires are released from the template and allowed to oxidize at room conditions over several weeks. The effects of partial oxidation on the structural and magnetic properties were studied by x-ray spectrometry, magnetometry, and scanning and transmission electron microscopy. The results indicate that the final nanowires are composed of 5 nm iron-cobalt alloy nanoparticles. Releasing the nanowires at room conditions promoted surface oxidation of the nanoparticles and created a CoFe2O4 shell spinel-like structure. The shell avoids internal oxidation and promotes the formation of bi-magnetic soft/hard magnetic core/shell nanowires. The magnetic properties of both the initial single-phase CoFe2.7 nanowires and the final core/shell nanowires, reveal that the changes in the properties from the array are due to the oxidation more than effects associated with released processes (disorder and agglomeration).

8.
Eur J Clin Pharmacol ; 72(11): 1303-1310, 2016 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-27515978

RESUMEN

PURPOSE: The purpose of this study is to evaluate the pharmacokinetics, immunogenicity, safety, and tolerability of guselkumab, a human monoclonal antibody with high affinity and specificity for binding to interleukin-23. METHODS: In this first-in-human, phase 1, randomized study, a single intravenous (IV; 0.03-10 mg/kg) or subcutaneous (SC; 10-300 mg) dose of guselkumab was administered to 47 healthy subjects, and a single SC dose (placebo, 10, 30, 100, 300 mg) was administered to 24 patients with moderate-to-severe psoriasis. RESULTS: Mean maximum observed serum concentration and area under the zero-to-infinity serum concentration-time curve of guselkumab increased in an approximately dose-proportional manner over the dose range of 0.03-10 mg/kg following a single IV administration or 10-300 mg following a single SC administration. Mean clearance and volume of distribution ranged from 3.62-6.03 mL/day/kg and 99.38-123.22 mL/kg, respectively. Mean half-life ranged from 12 to 19 days in healthy subjects and patients with psoriasis. Among guselkumab-treated subjects/patients, 1/30 (3.3 %) healthy subjects in the IV group, 0/6 healthy subjects in the SC group, and 1/20 (5.0 %) patients with psoriasis tested positive for antibodies to guselkumab. No clinically significant adverse events were identified in this study. CONCLUSION: Guselkumab pharmacokinetic profiles were generally comparable between healthy subjects and patients with psoriasis. Guselkumab, administered as an IV infusion or SC injection, was well tolerated in healthy subjects and patients with psoriasis.


Asunto(s)
Anticuerpos Monoclonales/farmacocinética , Fármacos Dermatológicos/farmacocinética , Adolescente , Adulto , Anciano , Anticuerpos Monoclonales/administración & dosificación , Anticuerpos Monoclonales/efectos adversos , Anticuerpos Monoclonales/sangre , Anticuerpos Monoclonales Humanizados , Área Bajo la Curva , Fármacos Dermatológicos/administración & dosificación , Fármacos Dermatológicos/efectos adversos , Fármacos Dermatológicos/sangre , Método Doble Ciego , Femenino , Semivida , Voluntarios Sanos , Humanos , Infusiones Intravenosas , Inyecciones Subcutáneas , Interleucina-23/antagonistas & inhibidores , Interleucina-23/inmunología , Masculino , Persona de Mediana Edad , Psoriasis/sangre , Psoriasis/tratamiento farmacológico , Psoriasis/metabolismo , Adulto Joven
9.
Cir Cir ; 84(1): 21-7, 2016.
Artículo en Español | MEDLINE | ID: mdl-26259742

RESUMEN

BACKGROUND: The risk of post-operative pneumonia is a latent complication. A study was conducted to determine its risk factors in abdominal surgery. MATERIAL AND METHODS: A cross-sectional study was performed that included analysing the variables of age and gender, chronic obstructive pulmonary disease and smoking, serum albumin, type of surgery and anaesthesia, emergency or elective surgery, incision site, duration of surgery, length of hospital stay, length of stay in the intensive care unit, and time on mechanical ventilation. The adjusted odds ratio for risk factors was obtained using multivariate logistic regression. RESULTS: The study included 91 (9.6%) patients with pneumonia and 851 (90.4%) without pneumonia. Age 60 years or over (OR=2.34), smoking (OR=9.48), chronic obstructive pulmonary disease (OR=3.52), emergency surgery (OR=2.48), general anaesthesia (OR=3.18), surgical time 120 minutes or over (OR=5.79), time in intensive care unit 7 days or over (OR=1.23), time on mechanical ventilation greater than or equal to 4 days (OR=5.93) and length of post-operative hospital stay of 15 days or over (OR=1.20), were observed as independent predictors for the development of postoperative pneumonia. CONCLUSIONS: Identifying risk factors for post-operative pneumonia may prevent their occurrence. The length in the intensive care unit of greater than or equal to 7 days (OR=1.23; 95% CI 1.07 - 1.42) and a length postoperative hospital stay of 15 days or more (OR=1.20; 95% CI 1.07 - 1.34) were the predictive factors most strongly associated with lung infection in this study.


Asunto(s)
Abdomen/cirugía , Infección Hospitalaria/epidemiología , Tiempo de Internación/estadística & datos numéricos , Complicaciones Posoperatorias/epidemiología , Neoplasias Abdominales/cirugía , Adulto , Distribución por Edad , Anciano , Anestesia/estadística & datos numéricos , Estudios Transversales , Procedimientos Quirúrgicos Electivos/estadística & datos numéricos , Urgencias Médicas , Femenino , Humanos , Unidades de Cuidados Intensivos/estadística & datos numéricos , Masculino , México/epidemiología , Persona de Mediana Edad , Tempo Operativo , Neumonía/etiología , Estudios Prospectivos , Enfermedad Pulmonar Obstructiva Crónica/epidemiología , Respiración Artificial/estadística & datos numéricos , Factores de Riesgo , Distribución por Sexo , Fumar/epidemiología , Centros de Atención Terciaria/estadística & datos numéricos
10.
Pulm Pharmacol Ther ; 33: 81-6, 2015 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-25966831

RESUMEN

RATIONALE: Soluble inflammatory markers obtained from non-invasive airway sampling such as induced sputum may be useful biomarkers for targeted pharmaceutical interventions. However, before these soluble markers can be used as potential targets, their variability and reproducibility need to be established in distinct study populations. OBJECTIVE: This study aimed to assess the reproducibility of biomarkers obtained from induced sputum and serum in chronic smokers and non-smokers. METHOD: Sputum and serum samples were obtained from 16 healthy non-smokers and 16 asymptomatic chronic smokers (for both groups: 8M/8F, 30-52 years, FEV1 ≥80% pred.; ≥10 pack years for the smokers) on 2 separate visits 4-10 days apart. Soluble markers in serum and sputum were analysed by ELISA. The differences between smokers vs non-smokers were analysed with a t-test and variability was assessed on log-transformed data by a mixed model ANOVA. RESULTS: Analysable sputum samples could be obtained from all 32 subjects. In both study populations neutrophils and macrophages were the predominant cell types. Serum Pulmonary Surfactant Associated Protein D had favourable reproducibility criteria for reliability ratio (0.99), intra-subject coefficient of variation (11.2%) and the Bland Altman limits of agreement. Furthermore, chronic smokers, compared to non-smokers, had significantly higher sputum concentrations of IL-8 (1094.6 pg/mL vs 460.8 pg/mL, p = 0.006)), and higher serum concentrations of Pulmonary Surfactant Associated Protein D (110.9 pg/mL vs 64.7 pg/mL, p = 0.019), and lower concentrations of Serum Amyloid A (1352.4 pg/mL vs 2297.5 pg/mL, p = 0.022). CONCLUSION: Serum Pulmonary Surfactant Associated Protein D proved to be a biomarker that fulfilled the criteria for reproducibility in both study groups.


Asunto(s)
Proteína D Asociada a Surfactante Pulmonar/sangre , Proteína Amiloide A Sérica/metabolismo , Fumar/metabolismo , Esputo/metabolismo , Adulto , Biomarcadores/metabolismo , Femenino , Humanos , Interleucina-8/metabolismo , Macrófagos/metabolismo , Masculino , Persona de Mediana Edad , Neutrófilos/metabolismo , Reproducibilidad de los Resultados
11.
J Allergy Clin Immunol ; 133(4): 1032-40, 2014 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-24679469

RESUMEN

BACKGROUND: IL-23 expression is increased in psoriatic lesions and might regulate TH17 T-cell counts in patients with psoriasis. OBJECTIVES: We sought to test a novel IL-23-specific therapeutic agent for the treatment of psoriasis. METHODS: In this randomized, double-blind, placebo-controlled study the safety, tolerability, and clinical response of guselkumab, an anti-IL-23-specific mAb, were evaluated in patients with moderate-to-severe plaque psoriasis. A total of 24 patients were randomized to receive a single dose of placebo or 10, 30, 100, or 300 mg of guselkumab. Clinical response was assessed by using the Psoriasis Area and Severity Index (PASI). Additionally, histologic analysis and gene expression in skin biopsy specimens from guselkumab-treated patients were compared with those from placebo-treated patients. RESULTS: At week 12, 50% (10 mg), 60% (30 and 100 mg), and 100% (300 mg) of guselkumab-treated patients, respectively, achieved a 75% improvement in PASI scores from baseline compared with 0% of placebo-treated patients. Improvements in PASI scores were generally maintained through week 24 in all guselkumab-treated patients. The proportion of patients experiencing an adverse event was comparable between the combined guselkumab (13/20 [65.0%]) and placebo (2/4 [50.0%]) groups through week 24. Analysis of lesional and nonlesional skin biopsy specimens demonstrated decreases in epidermal thickness and T-cell and dendritic cell expression in guselkumab-treated patients compared with values seen in placebo-treated patients. At week 12, significant reductions in psoriasis gene expression and serum IL-17A levels were observed in guselkumab-treated patients. CONCLUSION: IL-23 inhibition with a single dose of guselkumab results in clinical responses in patients with moderate-to-severe psoriasis, suggesting that neutralization of IL-23 alone is a promising therapy for psoriasis.


Asunto(s)
Anticuerpos Monoclonales/uso terapéutico , Interleucina-23/antagonistas & inhibidores , Psoriasis/tratamiento farmacológico , Anticuerpos Monoclonales/administración & dosificación , Anticuerpos Monoclonales/efectos adversos , Anticuerpos Monoclonales Humanizados , Anticuerpos Neutralizantes/administración & dosificación , Anticuerpos Neutralizantes/efectos adversos , Anticuerpos Neutralizantes/uso terapéutico , Biomarcadores , Biopsia , Análisis por Conglomerados , Citocinas/sangre , Citocinas/metabolismo , Perfilación de la Expresión Génica , Humanos , Mediadores de Inflamación/sangre , Mediadores de Inflamación/metabolismo , Interleucina-17/sangre , Psoriasis/genética , Psoriasis/inmunología , Psoriasis/metabolismo , Psoriasis/patología , Piel/inmunología , Piel/patología , Células Th17/inmunología , Células Th17/metabolismo , Resultado del Tratamiento
12.
J Invest Dermatol ; 131(8): 1622-30, 2011 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-21593767

RESUMEN

Photosensitivity is an important and distinguishing sign in various subtypes of cutaneous lupus erythematosus (CLE); however, it remains poorly defined. The purpose of this study was to evaluate whether standardized photoprovocation is a reproducible method to assess photosensitivity in subjects with CLE. A total of 47 subjects with CLE (subacute cutaneous lupus erythematosus (SCLE), n=14; discoid lupus erythematosus (DLE), n=20; lupus erythematosus tumidus (LET), n=13) and 13 healthy volunteers underwent photoprovocation at seven European sites. Of these, 22 (47%) subjects (57% SCLE, 35% DLE, and 54% LET) and none of the healthy volunteers developed photoprovoked lesions according to clinical analysis. Of these 22 subjects, 19 (86%) developed lesions that were histopathologically confirmed as specific for lupus erythematosus (LE). In CLE subjects who developed UV-induced lesions, 86% had Fitzpatrick's phototypes I or II, and the mean minimal erythema dose (MED) was significantly lower compared with subjects without UV-induced lesions (P=0.004). No significant differences in photoprovocation results were observed between study sites. Safety parameters showed no clinically meaningful differences between CLE subjects and healthy volunteers after photoprovocation. In conclusion, a standardized, safe, and reproducible protocol for photoprovocation using UVA and UVB radiation induced skin lesions in approximately half of all CLE subjects and showed comparable results across multiple sites. This method may therefore be used for future diagnostic testing and clinical trials.


Asunto(s)
Técnicas y Procedimientos Diagnósticos/normas , Lupus Eritematoso Cutáneo/diagnóstico , Lupus Eritematoso Discoide/diagnóstico , Trastornos por Fotosensibilidad/diagnóstico , Rayos Ultravioleta , Adolescente , Adulto , Anciano , Antimaláricos/uso terapéutico , Técnicas y Procedimientos Diagnósticos/efectos adversos , Relación Dosis-Respuesta en la Radiación , Femenino , Humanos , Masculino , Persona de Mediana Edad , Reproducibilidad de los Resultados , Fumar , Adulto Joven
13.
Respir Med ; 104(6): 917-20, 2010 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-20227269

RESUMEN

BACKGROUND: Nitric oxide (NO) measurements in exhaled air and hypertonic saline-induced sputum are commonly used biomarker sampling methods of the lower airways. Both sampling methods have been validated in asthmatic patients and healthy controls, however, data from chronic smokers are scarce. OBJECTIVES: To evaluate the reproducibility and differences in fractional exhaled NO (FeNO) values in asymptomatic chronic smokers and healthy, non-smoking controls. Furthermore, to test the effect of hypertonic saline sputum induction (SI) on FeNO levels in both study groups. METHODS: 16 asymptomatic chronic smokers and 16 non-smokers participated in this study. Baseline FeNO and forced expiratory volume in 1 s (FEV(1)) were recorded pre- and 30 min post NaCl 4.5% SI (3 x 5 min) on 2 study days (+/-2 h; 4-10 days apart). Mixed ANOVA was used to estimate the intra-subject Coefficient of Variation (CV) % over days; changes in FeNO and FEV(1) values before and after SI, were analyzed by a Student's paired t-test.The difference between smokers and non-smokers was estimated by a Student's t-test. RESULTS: On day 1, FeNO values in smokers were significantly lower than in non-smokers, 10.6 ppb, and 18.4 ppb, respectively, (42% difference, p = 0.0028, 95% CI: -59%, -19%). In both study groups, FeNO measurements were reproducible, with an intra-subject CV of 27.2% and 19.2%, for smokers and non-smokers, respectively. SI significantly decreased FeNO levels in both study groups on day 1. In smokers, there was a mean reduction in FeNO of almost 37% (p = 0.0045, 95% CI: -53%, -14%), and in non-smokers a mean decrease of almost 37% (95% CI : -53%, -14%; p = 0.0045). In both study groups SI did not affect FEV(1) (p > 0.94). CONCLUSIONS: Our data extend previous findings in asthmatics and healthy controls to asymptomatic chronic smokers: 1. FeNO measurements are reproducible in both smokers and non-smokers; 2. baseline FeNO levels in chronic smokers are lower than in non-smokers and 3. sputum induction by hypertonic saline reduces FeNO levels in both study groups, without affecting lung function.


Asunto(s)
Óxido Nítrico/metabolismo , Solución Salina Hipertónica/uso terapéutico , Esputo/metabolismo , Adulto , Pruebas Respiratorias , Espiración , Femenino , Volumen Espiratorio Forzado , Humanos , Masculino , Persona de Mediana Edad
14.
Int J Oncol ; 32(3): 713-21, 2008 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-18292949

RESUMEN

Nitric oxide (NO) is one of the main cytotoxic effector molecules involved in the killing of tumor cells by macrophages. In macrophages, lipopolysaccharide (LPS) alone or in combination with IFN-gamma causes the generation of NO by an inducible form of NO synthase (iNOS). We have previously reported that macrophages from mammary tumor bearers have a downregulation of their NO production leading to a diminished cytotoxic activity. Further studies lead to the isolation and characterization of phosphatidyl serine (PS) as a NO inhibitory factor produced by mammary tumor cells. Pretreatment of macrophages with PS was shown to downregulate their cytotoxic potential and NO production upon stimulation with LPS. Activation of PS-pretreated macrophages with LPS and IFN-gamma resulted in higher levels of NO than those observed with LPS alone, but lower than those of untreated macrophages activated with LPS and IFN-gamma. These results correlated with the levels of iNOS RNA as detected by Northern blot analyses. A study of the expression and binding activity of the transcription factor NF kappa B in macrophages pretreated with PS revealed no differences with untreated macrophages. Investigation of the possible signaling pathways leading to the induction of iNOS revealed that in LPS-stimulated macrophages, increases in internal calcium concentration [Ca2+]i were not observed, while NO was normally produced even under calcium-deprived conditions. In contrast, an effective synergism of IFN-gamma with LPS in the production of NO by macrophages required an optimal increase in [Ca2+]i stimulated by IFN-gamma. This increment in [Ca2+]i was significantly reduced in PS-pretreated macrophages. Further experiments demonstrated that pretreatment of macrophages with PS did not change the normal pattern of tyrosine phosphorylation stimulated by LPS but strikingly inhibited PKC activity. Combinations of LPS and IFN-gamma did not alter the latter result, suggesting that IFN-gamma enhances LPS-induction of iNOS through a pathway other than activation of PKC. Importantly, expression of PKC isozymes in both untreated and PS-pretreated macrophages stimulated with LPS remained constant. Out data suggest that, in tumor bearers, PKC and not NF kappa B is the main target for PS to exert its NO inhibitory action on LPS-activated macrophages. An excess of PS in PS-PKC interaction may be responsible, at least in part, for this type of PKC inhibition. Furthermore, PS also appears to downregulate the rise in [Ca2+]i promoted by IFN-gamma in macrophages, reducing the synergism of this cytokine with LPS and leading to a less effective production of NO.


Asunto(s)
Regulación Enzimológica de la Expresión Génica/efectos de los fármacos , Macrófagos Peritoneales/enzimología , FN-kappa B/fisiología , Neoplasias/metabolismo , Óxido Nítrico Sintasa/genética , Fosfatidilserinas/farmacología , Proteína Quinasa C/fisiología , Animales , Calcimicina/farmacología , Calcio/metabolismo , Femenino , Interferón gamma/farmacología , Ionóforos/farmacología , Lipopolisacáridos/farmacología , Activación de Macrófagos/efectos de los fármacos , Macrófagos Peritoneales/efectos de los fármacos , Masculino , Ratones , Ratones Endogámicos BALB C , Óxido Nítrico/metabolismo , Óxido Nítrico Sintasa/metabolismo , Fosfatidilserinas/metabolismo , ARN Mensajero/metabolismo
15.
Horiz. méd. (Impresa) ; 5(2): 12-21, dic. 2005. graf
Artículo en Español | LILACS, LIPECS | ID: lil-677710

RESUMEN

Este estudio fue realizado en la Villa Deportiva del Club Deportivo Universidad San Martín de Porres, Facultad de Medicina Humana de la Universidad San Martín de Porres - Laboratorio de Bioquímica y Nutrición, Febrero-Marzo 2005. El tipo de estudio fue de intervención, comparativo, longitudinal y prospectivo, y responde a un diseño de investigación pre y post test. El objetivo de este estudio fue evaluar la respuesta cardiorespiratoria en futbolistas profesionales y no profesionales al ser sometidos a ejercicio físico. La edad promedio fue de 27 años en el grupo conformado por futbolistas profesionales y en el grupo referencial de futbolistas no profesionales fue de 18 años. La variación de los niveles de ácido láctico en los futbolistas profesionales guarda relación inversa con la disminución en la variación de la saturación de oxígeno y en los futbolistas no profesionales una relación directa en estas variables. La variación del ácido láctico, tanto en futbolistas profesionales como en no profesionales, tiene relación con el incremento de la frecuencia cardiaca, observándose mayor diferencia y relación en el grupo de futbolistas no profesionales.


The study was carried out at the Villa Deportiva del Club Deportivo Universidad San Martin de Porres, the School of Human Medicine of San Martin de Porres University and the Biochemistry and Nutrition Laboratories between. February - March 2005. The study was of intervention, comparative, longitudinal and prospective type, and it corresponds to a pre and post test design investigation. The objective was to evaluate the cardio-respiratory answer in professional and non professional soccer players after physical exercise. The average age of the participants in the study was 27 years old in the group of professional soccer players, and 18 years old in the reference group of non professional soccer players. The variation of lactic acid levels in professional footballers shows an inverse relation with regard to the decrease in variation of oxygen saturation and in non professional soccer players a direct relation in these variables was observed. The variation of lactic acid in professional as in non professional soccer players is in relation with the increment of cardiac frequency, where a bigger difference and relation in the non professional soccer players group was observed.


Asunto(s)
Humanos , Masculino , Adolescente , Adulto , Femenino , Deportes , Ejercicio Físico , Frecuencia Cardíaca/fisiología , Fútbol , Presión Sanguínea , Ácido Láctico , Estudios Longitudinales , Estudios Prospectivos
16.
J Am Geriatr Soc ; 51(2): 147-54, 2003 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-12558709

RESUMEN

OBJECTIVES: To compare the effects of topical collagen and hydrocolloid on pressure ulcer healing. DESIGN: Randomized (allocation concealed), single-blind (outcome assessors), controlled trial with 8-week follow-up. SETTING: Eleven nursing homes in central Illinois. PARTICIPANTS: Sixty-five patient-residents with Stage II or III pressure ulcers: median age 83.1, median Braden score 12, 63% female, 80% Stage II ulcers, and 20% Stage III ulcers. Exclusion criteria included cellulitis and osteomyelitis. INTERVENTION: Thirty-five patients were allocated to topical collagen daily, 30 to topical hydrocolloid twice weekly. MEASUREMENTS: The primary outcome was complete healing within 8 weeks. Secondary outcomes were time to heal, ulcer area healed per day, linear healing of wound edge, and cost of therapy. RESULTS: Analysis by intention to treat revealed similar complete ulcer healing within 8 weeks in collagen (51%) and hydrocolloid (50%) recipients (difference 1%, 95% confidence interval (CI) = 26-29%). Mean healing time was similar: collagen healed in 5 weeks (95% CI = 4-6), hydrocolloid healed in 6 weeks (95% CI = 5-7). Mean area healed per day was 6 mm(2)/d in both treatment groups. Mean linear healing of the wound edge was 3 mm in both groups. In multivariate analysis, baseline ulcer depth was the only independent predictor of complete ulcer healing within 8 weeks (odds ratio = 0.56, 95% CI = 0.38-0.81). Cost analysis favored hydrocolloid. CONCLUSIONS: There were no significant differences in healing outcome between collagen and hydrocolloid. Collagen was more expensive and offered no major benefits to patients otherwise eligible for hydrocolloid treatment.


Asunto(s)
Colágeno/uso terapéutico , Coloides/uso terapéutico , Úlcera por Presión/tratamiento farmacológico , Anciano , Anciano de 80 o más Años , Colágeno/economía , Coloides/economía , Costos y Análisis de Costo , Femenino , Humanos , Masculino , Úlcera por Presión/economía , Método Simple Ciego
17.
Rev. Soc. Peru. Med. Interna ; 16(1): 10-16, 2003. ilus
Artículo en Español | LILACS, LIPECS | ID: lil-484263

RESUMEN

The erythromelalgia is a rare condition characterized by te triad of red, hot and painful extremities, make the diagnosis is often problem because the patients have intermitent symptoms and findings not present during the physical examination. The diagnostician, therefore or by elevating the affected extremity, classically inmersion in buckets of cool ice or ice water that is mandatory for the diagnosis has remained an enigma diagnostically and therapeutically for decades and there is little information about its natural history, and optimal treatments, no objetive diagnostic criteria exist for applying the diagnosis of Erythromelalgia and confusion exists in the literature concerning nomenclature and classification. We report the first case of erythromelalgia based in the clinics, medical record physical examination and the laboratory findings in a patient who is from Lima. There is a not previous reported case in the natural literature.


Asunto(s)
Humanos , Adulto , Femenino , Eritromelalgia , Extremidades
18.
Rev. oftalmol. venez ; 51(3-4): 67-77, jul.-dic. 1995. ilus, tab
Artículo en Español | LILACS | ID: lil-259404

RESUMEN

Las células madres del epitelio corneal se piensa que están localizadas en el limbo. El tejido limbal fue removido quirúrgicamente en uno de los ojos de 56 conejos New Zealand y se practicó la desepitelización corneal en ambos ojos utilizando n-heptanol. Comparamos el crecimiento epitelial entre ambos ojos a las 24 horas, 48 horas, 72 horas, 7 días y ocho semanas. En un grupo constituído por 5 conejos practicamos sólo la desepitelización corneal en 7 mm. centrales. Evidenciamos un crecimiento mayor, estadísticamente significativo, en los ojos controles en los cuales se conservó el tejido limbal que en aquellos en los cuales se removió y mayor en los defectos epiteliales menores que en aquellos extensos. Observamos además mayor conjuntivalización y vascularización en los ojos queratolimbectomizados que en los controles, fenómeno éste que fue inversamente proporcional a la reepitelización


Asunto(s)
Animales , Conejos , Conejos/clasificación , Heptanol/administración & dosificación , Limbo de la Córnea/cirugía , Oftalmología
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...