First Detection of Acinetobacter baumannii in Pediculus humanus capitis from Latin America.

Several studies have documented the presence of Acinetobacter baumannii, a known multi-drug-resistant pathogen, in the human head louse, Pediculus humanus capitis. Since no reports from countries in Latin America have been published, the aim of the present study was to determine whether A. baumannii was present in head lice specimens collected in this geographic region. Head lice specimens from Argentina, Colombia, and Honduras were analyzed. PCR assays were performed to confirm the specimens' species and to investigate whether the DNA of A. baumannii was present. The products of the latter were sequenced to confirm bacterial identity. Altogether, 122 pools of head lice were analyzed, of which two (1.64%) were positive for A. baumannii's DNA. The positive head lice had been collected at the poorest study site in Honduras. The remaining specimens were negative. This study is the first to report the presence of A. baumannii in human head lice from Latin America. Further investigations are required to elucidate whether these ectoparasites can serve as natural reservoirs or even effectively transmit A. baumannii to humans.

Risk factors associated with thyroid nodular disease in acromegalic patients: A case-cohort study in a tertiary center.

INTRODUCTION: Goiter is very common in patients with acromegaly; its development is correlated to the duration of the disease. Thyroid cells express the IGF-1 receptor and the TSH/IGF-1 interaction has been demonstrated to have a synergistic effect in thyroid cell growth. There is a correlation between IGF-1 levels and the thyroid volume of patients with acromegaly. The aim of this study was to evaluate, in a retrospective case-cohort study of patients with acromegaly, the associated risk factors for thyroid nodules disease in this population. METHODS: This was a case-cohort study matched by age, gender, and growth hormone at diagnosis. Cases consisted of acromegalic patients that developed thyroid nodules during the follow up, and controls consisted in acromegalic patients without thyroid nodules. A Cox proportional hazard estimation was carried out for measure the associated risk factors for thyroid nodules disease in acromegalic patients. A nodular thyroid disease-free survival analysis was estimated using the Kaplan-Meier analysis. RESULTS: We recruited 49 cases and 56 controls. In a multivariate Cox proportional hazard analysis age and IGF-1 ≥ 2.2 x ULN were significantly related with the presence of thyroid nodules [HR of 2.21 (95% CI; 1.15-4.25, p = 0.01)]. Nodularity-free survival rates in patients who had an IGF-1 X ULN ≥ 2.2 was found to be lower in comparison to those who had IGF-1 X ULN < 2.2, according to a Kaplan-Meier survival analysis. CONCLUSIONS: Our findings support that exist more probability to develop thyroid nodular disease in patients with acromegaly that present IGF-1 X ULN ≥ 2.2, suggesting a possible direct effect between the time of exposure to the IGF-1 axis hyperactivity and the genesis of thyroid nodules.

Phenolic Compounds in Honey and Their Relationship with Antioxidant Activity, Botanical Origin, and Color.

Honey has been employed since antiquity due to its sensory, nutritional, and therapeutic properties. These characteristics are related to its physical and chemical composition. For example, phenolic compounds are substances that can determine antioxidant activity, as well as sensory characteristics, and can be employed as biomarkers of floral and geographical origin. This has generated a growing interest in the study of phenolic compounds and their influence in the intrinsic properties of this beekeeping product. This review aims to summarize, analyze, and update the status of the research that demonstrates the role of phenolic compounds in antioxidant activity, botanical-geographical origin, and the sensory characteristics of honey. These phenolic compounds, according to various results reported, have great relevance in honey's biological and functional activity. This leads to research that will link phenolic compounds to their floral, geographical, productive, and territorial origin, as well as some sensory and functional characteristics.

What Will Happen to Biomedical Research in Low-and-Middle Income Countries in the PostCOVID-19 World?

Scientific research is essential for a nation's development and is vital for generating solutions to population's health. Individual country's capacities to prevent and respond to public health issues, including health crises, is built with long-term investment in highly qualified professionals, infrastructure, and uninterrupted operating funding. Most Latin American countries, especially those at the bottom of the human development list, have limited capacity even though they are hot spots for tropical and other emerging infectious diseases. This weakness deepens these countries' dependence on nations with higher development and corresponding scientific capacity. The current COVID-19 pandemic has wreaked havoc on the health of the world's population and the global economy. Countries that lagged behind prior to the pandemic now face a myriad of additional challenges. On a more optimistic note, the pandemic could serve as a wake-up call for governments and funding agencies to strengthen scientific capacity around the world, so that we are better prepared to address the public health issues caused by current and prevalent diseases and by future diseases of pandemic potential.

Expanding detection windows for discriminating single nucleotide variants using rationally designed DNA equalizer probes.

Combining experimental and simulation strategies to facilitate the design and operation of nucleic acid hybridization probes are highly important to both fundamental DNA nanotechnology and diverse biological/biomedical applications. Herein, we introduce a DNA equalizer gate (DEG) approach, a class of simulation-guided nucleic acid hybridization probes that drastically expand detection windows for discriminating single nucleotide variants in double-stranded DNA (dsDNA) via the user-definable transformation of the quantitative relationship between the detection signal and target concentrations. A thermodynamic-driven theoretical model was also developed, which quantitatively simulates and predicts the performance of DEG. The effectiveness of DEG for expanding detection windows and improving sequence selectivity was demonstrated both in silico and experimentally. As DEG acts directly on dsDNA, it is readily adaptable to nucleic acid amplification techniques, such as polymerase chain reaction (PCR). The practical usefulness of DEG was demonstrated through the simultaneous detection of infections and the screening of drug-resistance in clinical parasitic worm samples collected from rural areas of Honduras.

Colorimetric Polymerase Chain Reaction Enabled by a Fast Light-Activated Substrate Chromogenic Detection Platform.

Miniaturization of nucleic acid tests (NATs) into portable, inexpensive detection platforms may aid disease diagnosis in point-of-care (POC) settings. Colorimetric signals are ideal readouts for portable NATs, and it remains of high demand to develop color readouts that are simple, quantitative, and versatile. Thus motivated, we report a fast light-activated substrate chromogenic polymerase chain reaction (FLASH PCR) that uses DNA intercalating dyes (DIDs) to enable colorimetric nucleic acid detection and quantification. The FLASH system is established on our finding that DID-DNA intercalation can promote the rapid photooxidation of chromogenic substrates through light-induced production of singlet oxygen. Using this principle, we have successfully converted DID-based fluorescent PCR assays into colorimetric FLASH PCR. To demonstrate the practical applicability of FLASH PCR to POC diagnosis, we also fabricated two readout platforms, including a portable electronic FLASH reader and a paper-based FLASH strip. Using the FLASH reader, we were able to detect as low as 60 copies of DNA standards, a limit of detection (LOD) comparable with commercial quantitative PCR. The FLASH strip further enables the reader-free detection of PCR amplicons by converting the colorimetric signal into the visual measurement of distance as a readout. Finally, the practical applicability of the FLASH PCR was demonstrated by the detection and/or quantification of nucleic acid markers in diverse clinical and biological samples.

El índice leucoglucémico es un predictor de mortalidad por todas las causas al año en pacientes cubanos con infarto agudo de miocardio con elevación del segmento ST / The leucoglycaemic index is a predictor of one-year all-cause mortality in Cuban patients with ST-segment elevation acute myocardial infarction

RESUMEN Introducción: El índice leucoglucémico (ILG) ha sido propuesto como marcador pronóstico de muerte en pacientes con infarto agudo de miocardio; sin embargo, no existe evidencia sobre su valor pronóstico al año. Objetivos: El objetivo del estudio fue determinar el valor pronóstico del ILG en la mortalidad al año de pacientes cubanos con infarto agudo de miocardio con elevación del segmento ST. Método: Los datos fueron obtenidos de las historias clínicas y el objetivo primario fue la muerte por todas las causas al año. El ILG se calculó con los valores al ingreso. Para el análisis se dividieron los pacientes en terciles de ILG, se construyeron curvas de características operativas del receptor y de supervivencia de Kaplan-Meier. Para el análisis multivariable se utilizó la regresión de Cox. Resultados: Se analizaron 344 pacientes (mediana de edad, 68 años; el 65,7% masculino; un 25,6% diabéticos). La mortalidad fue de 25,6% y fue significativamente mayor en el tercil superior (55,7%; p<0,0001). Los pacientes fallecidos presentaron una mediana de ILG significativamente mayor que los sobrevivientes (2,18 y 1,34, respectivamente; p<0,0001). El área bajo la curva del ILG fue de 0,715 y el punto de corte: 2,2. Un valor de ILG mayor de 2,2 se asoció a una supervivencia significativamente menor (177 vs. 309 días; p<0,0001) y fue un predictor independiente de mortalidad (HR=3,56; IC 95%, 2,09-6,07; p<0,0001). Conclusiones: El índice leucoglucémico es buen predictor de mortalidad al año, por todas las causas, en pacientes con infarto agudo de miocardio con elevación del segmento ST.

ABSTRACT Introduction: The leuko-glycaemic index has been proposed as a prognostic marker of death in patients with acute myocardial infarction, but there is uncertainty surrounding its prognostic value to predict one-year mortality. Objectives: The aim of this study was to determine the prognostic value of leuko-glycaemic index for one-year mortality in Cuban patients with ST-segment elevation myocardial infarction. Methods: The data were obtained from the medical records and all cause one-year deaths was the primary endpoint. The leuko-glycaemic index was calculated from measurements at admission. The patients were divided into leuko-glycaemic index tertiles to be evaluated. Receiver operating characteristics and Kaplan-Meier survival curves were performed. Cox regression model was used for all multivariable analysis. Results: Three hundred and forty-four patients were assessed (median age, 68 years; 65.7% males; 25.6% diabetic). The mortality rate was 25.6%, being significantly higher in the upper tertile (55.7%, p<0.0001). The deceased patients presented a median of leuko-glycaemic index significantly higher than the survivors (2.18 and 1.34 respectively, p<0.0001). The area under the curve for leuko-glycaemic index was 0.715 and its cut-off value was 2.2. Any leuko-glycaemic index value higher than 2.2 was associated with significantly lower survival (177 vs. 309 days, p<0.0001) and it was an independent predictor of mortality (HR=3.56, CI 95%, 2.09-6.07, p<0.0001). Conclusions: The leuko-glycaemic index is a good predictor for all cause one-year mortality in patients with ST-segment elevation myocardial infarction.

Paper-Based DNA Reader for Visualized Quantification of Soil-Transmitted Helminth Infections.

Soil-transmitted helminth (STH) infections are a global health issue affecting nearly one-third of the world's population. As most endemic areas of STH are impoverished countries or regions with limited healthcare resources, the accurate diagnosis of STH requires analytical tools that are not only quantitative, but also portable, inexpensive, and with no or minimal demand for external instrument. Herein, we introduce a novel paper-based diagnostic device, termed quantitative paper-based DNA reader (qPDR), capable of quantifying STH at the molecular level by measuring distance as readout, thus eliminating the need for external readers. On the basis of the unique interfacial interaction of a DNA intercalating dye, SYBR Green I, with native cellulose on a chromatographic paper, qPDR allows the distance-based quantification of minute amounts of double-stranded DNA as short as 6 min. By integrating qPDR with polymerase chain reactions that were performed using a smartphone-controlled portable thermal cycler, we were able to quantify minute amount of genetic markers from adult worms of an STH (Trichuris trichiura) that were expelled post-treatment by infected children living in the rural areas of Honduras.

Glucose-6-phosphate dehydrogenase deficiency among malaria patients of Honduras: a descriptive study of archival blood samples.

BACKGROUND: The frequency of deficient variants of glucose-6-phosphate dehydrogenase (G6PDd) is particularly high in areas where malaria is endemic. The administration of antirelapse drugs, such as primaquine, has the potential to trigger an oxidative event in G6PD-deficient individuals. According to Honduras´ national scheme, malaria treatment requires the administration of chloroquine and primaquine for both Plasmodium vivax and Plasmodium falciparum infections. The present study aimed at investigating for the first time in Honduras the frequency of the two most common G6PDd variants. METHODS: This was a descriptive study utilizing 398 archival DNA samples of patients that had been diagnosed with malaria due to P. vivax, P. falciparum, or both. The most common allelic variants of G6PD: G6PD A+(376G) and G6PD A-(376G/202A) were assessed by two molecular methods (PCR-RFLP and a commercial kit). RESULTS: The overall frequency of G6PD deficient genotypes was 16.08%. The frequency of the "African" genotype A- (Class III) was 11.9% (4.1% A- hemizygous males; 1.5% homozygous A- females; and 6.3% heterozygous A- females). A high frequency of G6PDd alleles was observed in samples from malaria patients residing in endemic regions of Northern Honduras. One case of Santamaria mutation (376G/542T) was detected. CONCLUSIONS: Compared to other studies in the Americas, as well as to data from predictive models, the present study identified a higher-than expected frequency of genotype A- in Honduras. Considering that the national standard of malaria treatment in the country includes primaquine, further research is necessary to ascertain the risk of PQ-triggered haemolytic reactions in sectors of the population more likely to carry G6PD mutations. Additionally, consideration should be given to utilizing point of care technologies to detect this genetic disorder prior administration of 8-aminoquinoline drugs, either primaquine or any new drug available in the near future.

A four-year surveillance program for detection of Plasmodium falciparum chloroquine resistance in Honduras.

Countries could use the monitoring of drug resistance in malaria parasites as an effective early warning system to develop the timely response mechanisms that are required to avert the further spread of malaria. Drug resistance surveillance is essential in areas where no drug resistance has been reported, especially if neighbouring countries have previously reported resistance. Here, we present the results of a four-year surveillance program based on the sequencing of the pfcrt gene of Plasmodium falciparum populations from endemic areas of Honduras. All isolates were susceptible to chloroquine, as revealed by the pfcrt "CVMNK" genotype in codons 72-76.

Factores de riesgo en diabetes mellitus y pie diabético: un enfoque hacia la prevención primaria / Risk factors of diabetes mellitus and diabetic foot: a primary approach to prevention

Objetivo: revisar la literatura sobre factores de riesgo asociados a diabetes mellitus y sus complicaciones, las estrategias de prevención y la importancia de programas interdisciplinarios para mejorar la calidad de vida. Fuente de datos: búsqueda de la literatura científica publicada en español e inglés, en bases de datos como Medline, SciELO y otras de la Universidad Nacional de Colombia mediante palabras clave; además, revisión de libros y consensos afines con el tema. Selección de estudios: se revisaron los títulos y resúmenes de documentos para seleccionar las publicaciones originales, así como las más representativas con relación a prevención primaria y educación. Extracción de datos: la literatura se clasificó y organizó de acuerdo con el tema principal y la estructura del artículo. Síntesis de datos: se inició un análisis crítico para ordenar y sintetizar los avances relacionados con los siguientes ítems: factores de riesgo para diabetes mellitus, epidemiología, pie diabético, educación, prevención primaria y estilos de vida relacionados con ejercicio y alimentación. Conclusión: el impacto de la diabetes mellitus y sus complicaciones en la salud de los individuos hace necesario establecer políticas de salud pública de prevención primaria, para minimizar el progreso de esta epidemia. Es esencial instaurar y fortalecer programas educativos orientados por profesionales de la salud, además de implementar la formación en diabetes mellitus en los currículos de pregrado y posgrado del área de la salud.

Objective: to review the literature on risk factors associated with diabetes mellitus and its complications, prevention strategies and the importance of interdisciplinary programs to improve the quality of life. Data Source: search of the scientific literature published in Spanish and English, in databases such as Medline, SciELO and others from the National University of Colombia using keywords; also book reviews and consensus related to the topic. Study Selection: the titles and abstracts of papers were reviewed in order to select the original publications, as well as the most representative ones in relation to primary prevention and education. Data Extraction: the literature was classified and organized according to the main theme and the structure of the article. Data synthesis: a critical analysis was initiated to organize and synthesize the advances related to the following items: risk factors for diabetes mellitus, epidemiology, diabetic foot, education, primary prevention and lifestyles related with exercise and diet. Conclusion: the impact of diabetes mellitus and its complications in the health of individuals makes it necessary to establish public health policies for primary prevention to minimize the progress of this epidemic. It is essential to establish and strengthen educational programs oriented by health professionals, as well as to implement the training in diabetes mellitus in the undergraduate and graduate curricula of the health area.

Compromiso respiratorio en embarazadas: puérperas hospitalizadas en el contexto de la Pandemia 2009 de Influenza A (H1N1)pdm09 / Respiratory compromise in hospitalised pregnant women: postpartum during Pandemic Influenza A (H1N1) pdm09, 2009

Introducción: el diagnóstico de influenza en gestantes está asociado a un alto riesgo de morbi-mortalidad. Objetivos: describir características clínico-epidemiológicas de embarazadas/puérperas cursando enfermedad tipo influenza (ETI) y el compromiso respiratorio durante la pandemia de influenza A (H1N1) pdm09. Comparar severidad según edad gestacional. Material y métodos: estudio retrospectivo, descriptivo mediante revisión de historias clínicas de embarazadas/puérperas internadas por ETI en dos maternidades, período: 27/06/09-14/08/09. Se tabularon en dos grupos: G1, n= 35 (1º y 2º trimestre); G2, n= 49 (3º trimestre/puerperio). Resultados: se incluyeron 84 pacientes, edad promedio 25 años (R: 14-42). 81% sin comorbilidades. 20% ingresaron a Unidad de Terapia Intensiva (UTI). El 54% consultó tardíamente. Presentaron neumonía el 50%. Recibió tratamiento antiviral el 89%. El 23% terminó su embarazo durante la internación por indicación obstétrica. El 94% del total presentó evolución favorable. Comparando G1 vs G2: necesidad de UTI (5/35 vs 12/49, p=0.25), roncus/sibilancias (8/35 vs. 18/49, p= 0,17), saturación de oxígeno menor de 96 % (6/35 vs 15/49 p=0,15), número de muertes (1/35 vs. 4/49, p= 0,30). Internación prolongada (3/35 vs 14/49, p= 0,02). La mortalidad general fue 6%. Conclusiones: la mayoría de las pacientes no presentaba comorbilidades y se encontraba cursando el tercer trimestre de embarazo o puerperio al momento de la internación. Hubo mayor frecuencia de compromiso respiratorio severo, internación en UTI y mortalidad en las pacientes en este grupo, sin diferencia significativa respecto al primer y segundo trimestre de embarazo. La mortalidad fue comparable a la reportada en la bibliografía.

Introduction: diagnosis of influenza in pregnant women is associated with a high risk of morbidity and mortality. Objectives: To describe clinical and epidemiological characteristics and respiratory compromise of hospitalized pregnant/postpartum women suffering from influenza like illness, assisted during the pandemic of influenza A (H1N1)pdm09 and compare serverity of respiratory compromise according to gestational age. Material and methods: retrospective, descriptive study through a review of medical charts of pregnant/postpartum women asisted in two maternity hospitals, period: 27/June to 14/August 2009. The data was tabulated into two groups: G1, n=35 (1st and 2nd Trimester), and G2, n=49, 3rd Trimester/puerperium. Results: 84 patients was included. Average age 25 years (R: 15-42). 81% without comorbidities. 20% was admitted on Intensive Care Unit (ICU). Pneumonia was diagnosed in 50%. 89% received antiviral treatment. 23% ended their pregnancy during the hospitalization for obstetric indication. 94% of the population presents favorable clinical evolution. Comparing G1 vs. G2: need for ICU admission (5/35 vs 12/49, p=0.25), presence of rhonchi/wheezing (8/35 vs 18/49, p=0.17), oxygen saturation < 96% (6/35 vs 15/49, p=0.15), mortality (1/35 vs 4/49, p=0.30), prolonged hospitalization (3/35 vs 14/49, p=0.02). Overall mortality was 6%. Conclusions: Most patientes had not comorbidities and was enrolled in the third trimester of pregnancy or puerperium at the time of hospitalization. There was a higher frequency of severe respiratory compromise, hospitalization in ICU and mortality in patients in this group, without significant difference compared to the first and second trimester. Mortality was comparable to that reported in the literature.

[Primary-care prevention activities in outpatients suffering from diabetic foot care]. / Actividades de prevención del pie diabético en pacientes de consulta externa de primer nivel.

OBJECTIVE: Determining the prevalence of prevention activities regarding diabetic foot recommended by doctors and carried out by out-patients attending general medicine self-care foot control and describing food habits. METHODS: This was a descriptive and cross-sectional studywhich was carried out in two health-care institutions in Bogotá, from March to October 2008, by weightedconveniencesampling of 307 diabetic patients, aged over 18 years. RESULTS: Some patients had a background of foot ulcers (13.0 %) and amputations of the lower limbs(1.6 %). Some patients referredto dysesthesia(65.5 %) and intermittent claudication (33.6 %)whilst many stated that they had received no education about foot care from their doctors(78.2 %). Many stated that the doctor had not checked their feet during the last year (76.2 %)and others that, despite presenting dysesthesia and intermittent claudication(89.0 % and 93.0 %, respectively), the patients had not been asked about these symptoms. Regarding patient activities,some did not checktheir feet each day (63.1 %), did not perform self-monitoring (93.4 %), consumed more than two sources of carbohydrateduring the main meals (38. %)and/or added sugar, "panela" or honey to preparations (38.8 %). CONCLUSIONS: The prevalence of diabetic foot prevention practices recommended by doctors and carried out by patients was poor. Interdisciplinary programmes must thus be created and strengthenedfor preventing diabetes mellitus and diabetic foot, at primary- attention out-patient level, besides providing pertinent trainingfor health teams.

Actividades de prevención del pie diabético en pacientes de consulta externa de primer nivel / Primary-care prevention activities in outpatients suffering from diabetic foot care

Objetivo Determinar la frecuencia de actividades de prevención del pie diabético recomendadas por el médico y efectuadas por pacientes de consulta externa en medicina general, para autocuidado de los pies y describir los hábitos alimentarios. Metodología Estudio descriptivo de corte transversal, realizado en dos instituciones de salud de Bogotá, marzo-octubre 2008; muestra ponderada, por conveniencia, 307 pacientes diabéticos mayores de 18 años. Resultados Antecedente de úlceras en pies 13 por ciento, amputaciones en miembros inferiores 1,6 por ciento. Refirieron: disestesias 65,5 por ciento y claudicación intermitente 33,6 por ciento; no habían recibido educación sobre el cuidado del pie por parte del médico 78,2 por ciento. Su médico no le había examinado los pies en el último año al 76,2 por ciento; a pesar de presentar disestesias y claudicación intermitente no se indagó sobre estos síntomas al 89 por ciento y 93 por ciento de pacientes respectivamente. Actividades de pacientes: no revisaban diariamente los pies 63,1 por ciento, no realizaban automonitoreo 93,4 por ciento, consumían más de dos fuentes de carbohidratos en comidas principales 38,1 por ciento; adicionaban a las preparaciones azúcar, panela, miel de abejas 38,8 por ciento. Conclusiones La prevalencia de actividades de prevención del pie diabético recomendadas por médicos y efectuadas por pacientes fue deficiente. Es necesario crear y fortalecer programas interdisciplinarios para la prevención de la diabetes mellitus y del pie diabético a nivel primario de atención, además de formación del equipo de profesionales en salud.

Objective Determining the prevalence of prevention activities regarding diabetic foot recommended by doctors and carried out by out-patients attending general medicine self-care foot control and describing food habits. Methods This was a descriptive and cross-sectional studywhich was carried out in two health-care institutions in Bogotá, from March to October 2008, by weightedconveniencesampling of 307 diabetic patients, aged over 18 years. Results Some patients had a background of foot ulcers (13.0 percent) and amputations of the lower limbs(1.6 percent). Some patients referredto dysesthesia(65.5 percent) and intermittent claudication (33.6 percent)whilst many stated that they had received no education about foot care from their doctors(78.2 percent). Many stated that the doctor had not checked their feet during the last year (76.2 percent)and others that, despite presenting dysesthesia and intermittent claudication(89.0 percent and 93.0 percent, respectively), the patients had not been asked about these symptoms. Regarding patient activities,some did not checktheir feet each day (63.1 percent), did not perform self-monitoring (93.4 percent), consumed more than two sources of carbohydrateduring the main meals (38. percent)and/or added sugar, "panela" or honey to preparations (38.8 percent). Conclusions The prevalence of diabetic foot prevention practices recommended by doctors and carried out by patients was poor. Interdisciplinary programmes must thus be created and strengthenedfor preventing diabetes mellitus and diabetic foot, at primary- attention out-patient level, besides providing pertinent trainingfor health teams.

K-space Prony's method for generating the basis functions of multi-Gaussian beam models.

The expansion coefficients of a multi-Gaussian ultrasonic beam model are obtained by a new approach that applies Prony s method in a K-space domain. This method allows the fitting of the Gaussian beam directly at the face of the transducer with very high computational efficiency. It is demonstrated that the K-space Prony's method can be used to accurately model the transducer field of planar and focused piston transducers, as well as probes that do not act as pistons. The choice of parameters appearing in the method and their influence on performance are discussed.

Determination of an ultrasonic transducer's sensitivity and impedance in a pulse-echo setup.

The role that an ultrasonic piezoelectric transducer plays in an ultrasonic measurement system can be described in terms of the transducer's input electrical impedance and its sensitivity. Here, a new model-based approach is proposed to determine both the transducer impedance and sensitivity in a pulse-echo setup. This new method is much simpler to apply than previous "self-reciprocity" calibration methods for determining sensitivity and generalizes those methods. It is demonstrated that sensitivities obtained with this new method agree well with the sensitivities obtained by a three-transducer method commonly used in calibration studies. It is demonstrated that at the megahertz frequencies at which ultrasonic transducers operate it is important to compensate for cabling effects in these measurements. The influence of the pulser/receiver settings on the results obtained also will be discussed.

Cryptosporidium spp. and other zoonotic enteric parasites in a sample of domestic dogs and cats in the Niagara region of Ontario.

To determine the prevalence of Cryptosporidium spp. and other zoonotic enteric parasites in a sample of domestic dogs and cats in the Niagara region, Ontario, 5 of 26 clinics invited by mail survey reported their parasitological findings over 24 months. Stool samples collected by 1 clinic over 68 days were investigated for parasites by using several techniques (fecal concentration, acid-fast staining, and a Cryptosporidium immunoassay). The 5 clinics that provided data indicated Toxocara spp. as the most frequent finding. Parasitological study of 111 stool samples showed a high overall positivity rate in samples from both dogs (40%) and cats (36.6%). Cryptosporidium spp. antigen was detected in 7.4% and 7.3%, Toxocara spp. in 14.2% and 12.2%, and Giardia spp. 7.1% and 2.4% of dog and cat samples, respectively. The high prevalence of zoonotic parasites in the Niagara region is important, and increased awareness of their potential threat to human health is necessary. Additionally, further research into the zoonotic capacity of Cryptosporidium spp. and Giardia spp. is necessary.

Media effects on students during SARS outbreak.

A few months after the 2003 severe acute respiratory syndrome (SARS) outbreak, a sample of Canadian undergraduate university students completed a questionnaire that showed that, despite believing media coverage of the outbreak was excessive, they had little anxiety about acquiring SARS. Additionally, 69% of participants failed a SARS-specific knowledge section of the questionnaire.

Adenoviral transfer of the murine oncostatin M gene suppresses dextran-sodium sulfate-induced colitis.

The use of biologics has promising potential in the treatment of inflammation. Studies with cultured cells and mouse models of disease have ascribed proinflammatory and anti-inflammatory functions to oncostatin M (OSM) and the related cytokine, interleukin-6 (IL-6). Here, we examined the effect of systemic administration of adenoviral (Ad) vectors encoding either murine OSM (AdMuOSM) or murine IL-6 (AdMuIL-6) in a mouse model of colitis. BALB/c mice were treated with a 5-day course of 4% dextran-sodium sulfate (DSS) water with or without administration of adenoviral vectors (i.p. or i.m. at 10(7) plaque-forming units [pfu]) given as a cotreatment or therapy. The deletion variant of the adenovirus served as a control for adenoviral infection. Colitis was assessed by (1) morphology (damage score, macrophage infiltration, apoptosis) and (2) function (myeloperoxidase activity and Ussing chamber analysis of epithelial ion transport). Infection with adenovirus alone did not affect colonic form or function. AdMuOSM (either i.p. or i.m.) significantly reduced the severity of the DSS-induced colitis. There was less damage, reduced macrophage infiltration, fewer apoptotic bodies, and a significant improvement in stimulated ion transport in colonic tissues from the treated mice. No benefit of AdMuIL-6 treatment was observed in this model system. Thus, systemic administration of AdMuOSM given as a cotreatment and to a lesser extent as a therapy was found to be of benefit in DSS-induced colitis, a murine model of inflammatory bowel disease (IBD).