Testing telediagnostic thyroid ultrasound in Peru: a new horizon in expanding access to imaging in rural and underserved areas.

PURPOSE: Thyroid ultrasound is a key tool in the evaluation of the thyroid, but billions of people around the world lack access to ultrasound imaging. In this study, we tested an asynchronous telediagnostic ultrasound system operated by individuals without prior ultrasound training which may be used to effectively evaluate the thyroid and improve access to imaging worldwide. METHODS: The telediagnostic system in this study utilizes volume sweep imaging (VSI), an imaging technique in which the operator scans the target region with simple sweeps of the ultrasound probe based on external body landmarks. Sweeps are recorded and saved as video clips for later interpretation by an expert. Two operators without prior ultrasound experience underwent 8 h of training on the thyroid VSI protocol and the operation of the telemedicine platform. After training, the operators scanned patients at a health center in Lima. Telediagnostic examinations were sent to the United States for remote interpretation. Standard of care thyroid ultrasound was performed by an experienced radiologist at the time of VSI examination to serve as a reference standard. RESULTS: Novice operators scanned 121 subjects with the thyroid VSI protocol. Of these exams, 88% were rated of excellent image quality showing complete or near complete thyroid visualization. There was 98.3% agreement on thyroid nodule presence between VSI teleultrasound and standard of care ultrasound (Cohen's kappa 0.91, P < 0.0001). VSI measured the thyroid size, on average, within 5 mm compared to standard of care. Readers of VSI were also able to effectively characterize thyroid nodules, and there was no significant difference in measurement of thyroid nodule size (P = 0.74) between VSI and standard of care. CONCLUSION: Thyroid VSI telediagnostic ultrasound demonstrated both excellent visualization of the thyroid gland and agreement with standard of care thyroid ultrasound for nodules and thyroid size evaluation. This system could be deployed for evaluation of palpable thyroid abnormalities, nodule follow-up, and epidemiological studies to promote global health and improve the availability of diagnostic imaging in underserved communities.

Clasificación Sistemática de Apósitos: Una Revisión Bibliográfica / Systemic Classification of Wound Dressings: a Review

Resumen En la actualidad existe un gran número de apósitos dada la amplia disponibilidad de biomateriales y principios bioactivos, por lo cual se hace necesario un consenso acerca de la clasificación de estos, para no generar confusiones a la hora de entender su utilidad y su idóneo manejo en el ambiente clínico. Por este motivo, en el presente artículo se hace una revisión bibliográfica utilizando las bases de datos SCOPUS, ScienceDirect y Web of Science, con ecuaciones de búsqueda que incluían las palabras clave de los diferentes tipos de apósitos. Con esta información se encuentra que los apósitos pueden ser clasificados de acuerdo con su complejidad, la naturaleza del material polimérico, su permeabilidad, su interacción biológica con la herida y su acción terapéutica, lográndose tener una definición detallada con todos las características relevantes para hacer una adecuada elección de un apósito. Adicionalmente, se incluye una revisión acerca del proceso de cicatrización y los tipos de heridas, dado que de esto dependen los fines terapéuticos y la selección de un apósito u otro.

Abstract Nowadays, there is wide variety of dressings because availability of biomaterials and bioactive components, thus a consensus is needed on their classification, to avoid in understanding their usefulness and their proper handling in clinical practice. Therefore, in this paper a bibliographic review is made using the SCOPUS, ScienceDirect and Web of science databases, with search equations which include the keywords of different types of wound dressings. With this information, we found that dressings can be classified according to their complexity, the nature of the polymeric material, its permeability, its biological interaction with the wound and its therapeutic action, in order to have a detailed definition with all the relevant characteristics to make a proper choice of a dressing. Additionally, a review about the healing process and the types of wounds is included, since this have an important influence on the therapeutic purposes and the correct selection of dressings.

Amino Acid-Functionalized Polyelectrolyte Films as Bioactive Surfaces for Cell Adhesion.

Surfaces were prepared with polyelectrolyte derivatives of poly(styrene- alt-maleic anhydride) (PSMA) functionalized with amino acids of different hydropathy indices, with the aim of evaluating the effect of the chemical functionality of polyelectrolytes on SH-SY5Y neuroblastoma cell adhesion. Functionalizing PSMA derivatives with l-glutamine, l-methionine, and l-tyrosine yielded PSMA-Gln, PSMA-Met, and PSMA-Tyr polyelectrolytes, respectively. We first studied the adsorption behavior of PSMA functionalized with amino acids on silicon wafer surfaces modified with 3-aminopropyltriethoxysilane at pH 4.0 and 7.0 and at low and high ionic strengths. The highest rate of polyelectrolyte adsorption was at pH 4.0 and high ionic strength and was higher with the glutamine and tyrosine films. The advance contact angles (θA) of the polyelectrolyte surfaces showed a moderate effect of ionic strength and pH on polyelectrolyte film wettability, with PSMA-Tyr being slightly more hydrophobic. Atomic force microscopy images of the polyelectrolyte surfaces showed two types of morphology: the well-defined globular nanostructure of PSMA-Met and PSMA-Tyr and densely packed nanofibrous-like structure of PSMA-Gln. The highest level of ionic strength caused a slight decrease in the size of the nanostructure that formed the surface domains, which was reflected in the degree of surface roughness. Cell adhesion assays with the polyelectrolyte film showed that SH-SY5Y neuroblastoma cells cultured on PSMA-Met present a well-extended morphology characterized by a stellate shape, with five or more actin-rich thin processes, whereas SH-SY5Y cells that were seeded on PSMA-Gln and PSMA-Tyr have a round morphology, with fewer and shorter processes. These results indicate that it is possible to modulate the surface characteristics of polyelectrolyte films based on their chemical functionality and environmental parameters such as pH and ionic strength in order to evaluate their effect on cell adhesion. Thus, surfaces prepared from polyelectrolytes functionalized with amino acids are an attractive and simple platform for cell adhesion, which can be used in developing biomaterials with modulated surface properties.

Porous Nanogold/Polyurethane Scaffolds with Improved Antibiofilm, Mechanical, and Thermal Properties and with Reduced Effects on Cell Viability: A Suitable Material for Soft Tissue Applications.

The use of implants carries on a series of problems, among them infections, poor biocompatibility, high levels of cytotoxicity, and significant mechanical differences between implants and host organs that promote stress shielding effects. These problems indicate that the materials used to make implants must meet essential requirements and high standards for implantations to be successful. In this work, we present the synthesis, characterization and evaluation of the antibiofilm, mechanical, and thermal properties, and cytotoxic effect of a nanocomposite-based scaffold on polyurethane (PU) and gold nanoparticles (AuNPs) for soft tissue applications. The effect of the quantity of AuNPs on the antibacterial activity of nanocomposite scaffolds was evaluated against Staphylococcus epidermidis and Klebsiella spp., with a resulting 99.99% inhibition of both bacteria using a small quantity of nanoparticles. Cytotoxicity was evaluated with the T10 1/2 test against fibroblast cells. The results demonstrated that porous nanogold/PU scaffolds have no toxic effects on fibroblast cells to the 5 day exposition. With respect to mechanical properties, stress-strain curves showed that the compressive modulus and yield strength of PU scaffolds were significantly enhanced by AuNPs (by at least 10 times). This is due to changes in the arrangement of hard segments of PU, which increase the stiffness of the polymer. Thermogravimetric analysis showed that the degradation onset temperature rises with an increase in the quantity of AuNPs. These properties and characteristics demonstrate that porous nanogold/PU scaffolds are suitable material for use in soft tissue implants.

A survey of zoonotic pathogens carried by house mouse and black rat populations in Yucatan, Mexico.

The house mouse (Mus musculus) and the black rat (Rattus rattus) are reservoir hosts for zoonotic pathogens, several of which cause neglected tropical diseases (NTDs). Studies of the prevalence of these NTD-causing zoonotic pathogens, in house mice and black rats from tropical residential areas are scarce. Three hundred and two house mice and 161 black rats were trapped in 2013 from two urban neighbourhoods and a rural village in Yucatan, Mexico, and subsequently tested for Trypanosoma cruzi, Hymenolepis diminuta and Leptospira interrogans. Using the polymerase chain reaction we detected T. cruzi DNA in the hearts of 4·9% (8/165) and 6·2% (7/113) of house mice and black rats, respectively. We applied the sedimentation technique to detect eggs of H. diminuta in 0·5% (1/182) and 14·2% (15/106) of house mice and black rats, respectively. Through the immunofluorescent imprint method, L. interrogans was identified in 0·9% (1/106) of rat kidney impressions. Our results suggest that the black rat could be an important reservoir for T. cruzi and H. diminuta in the studied sites. Further studies examining seasonal and geographical patterns could increase our knowledge on the epidemiology of these pathogens in Mexico and the risk to public health posed by rodents.

Antibacterial and non-cytotoxic effect of nanocomposites based in polyethylene and copper nanoparticles.

In this study, an antibacterial, but not cytotoxic nanomaterial based on polyethylene and copper nanoparticles was prepared by in situ polymerization. PE-CuNps nanocomposites against Escherichia coli, completely suppressed the number of live bacteria after 12 h incubation compared to neat PE. TEM images showed that nanocomposites damage the plasma membrane of the bacteria, revealing a bacteriolytic effect. Toxic effects of copper nanoparticles on viability of neuroblastoma line cell also was evaluated, revealing a non cytotoxic effect for the doses used, showing that this nanocomposite is a ideal material for medical devices.

Release of silver and copper nanoparticles from polyethylene nanocomposites and their penetration into Listeria monocytogenes.

Since infection is a major cause of death in a patient whose immune responses have been compromised (immunocompromised patient), considerable attention has been focused on developing materials for the prevention of infections. This has been directed primarily at suppressing or eliminating the host's endogenous microbial burden and decreasing the acquisition of new organisms. In this study, the antibacterial properties of two nanocomposites, polyethylene modified with silver nanoparticles (PE-AgNps) or copper nanoparticles (PE-CuNps), against Listeria monocytogenes have been investigated. In order to elucidate the antibacterial mechanism, specifically whether this mechanism corresponds to bactericidal or bacteriolytic activities, we have determined the extent of release of metal ions (Ag(+) and Cu(2+)) and, also, the morphology of the bacteria. The metal ion release from nanocomposites was followed by inductively coupled plasma spectrometry and the morphology of the bacteria was revealed through examination of ultramicrotomed sections of bacteria in a transmission electron microscope. The study of metal ion release from the nanocomposites shows that for both nanocomposites the amount of ions released varies with time, which initially displays a linear behavior until an asymptotic behavior is reached. Further, TEM images show that silver nanoparticles (AgNps) and copper nanoparticles (CuNps), which are released from the nanocomposites, can penetrate to the cell wall and the plasma membrane of bacteria. Resulting morphological changes involve separation of the cytoplasmic membrane from the cell wall, which is known to be an effect of plasmolysis. It was revealed that the antibacterial abilities of the two nanocomposites against L. monocytogenes are associated with both bactericidal and bacteriolytic effects.

Bloqueo de los canales de potasio en el shock séptico, ¿otra esperanza perdida? / Blockage of potassium channels in septic shock, another lost hope?

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El tamizaje bucal. Fundamentos y presentación de una experiencia / Bucal screening. Fundamentals and presentation of an experience. An academic essay

Este artículo presenta la experiencia de aplicación de una prueba tamiz para la identificación precoz de la patología bucal. Se expone el concepto, los componentes, las características, las ventajas y desventajas del método y se analizan los resultados de su aplicación en la práctica. Los índices precisos de caries en las colectividades no se conocen por la dificultad de realizar estudios masivos y periódicos, pero se infiere que su incidencia va en aumento porque los escolares no están acudiendo a los centros de atención, según informes recientes de instituciones odontológicas comprometidas con la salud pública en Antioquia. El tamizaje es una estrategia que permite la detección de factores de riesgo y el diagnóstico precoz de enfermedades desde la fase asintomática. Con el tamizaje bucal se induce la demanda a los centros de atención, detectando tempranamente muchas patologías orales en grandes poblaciones de niños y adolescentes. También se puede lograr un diagnóstico presuntivo del estado de salud bucal que provea información para establecer la magnitud de los problemas y un programa de tratamiento preventivo. En el municipio de Envigado, Antioquia, se tamizaron 10.489 niños de las escuelas públicas con el mínimo de costos, complejidad y demora y con buena aceptación de la comunidad. Se orientaron los niños afectados a sus respectivos servicios de salud por medio de remisiones a padres de familia y maestros. El tamizaje bucal debe efectuarse periódicamente con el fin de hacer vigilancia epidemiológica a problemas tan frecuentes como la caries dental.

Prevalence and nature of nail alterations in pediatric patients.

The purpose of this investigation was to explore the frequency and nature of ungual alterations in patients of a pediatric dermatology department at a third-level pediatric hospital. The first 20 patients with nail alterations seen each year during a 5-year period from 1992 through 1996 were included, totaling 100 patients. The rate of nail alterations was 11% (1/9) in pediatric dermatology patients. There were 5 infants, 19 preschoolers (2- to 5-year-olds), 38 school children (6- to 11-year-olds), and 38 adolescents (12- to 17-year-olds). The most frequent diagnoses were onychomycosis (23), nail alterations in a genodermatosis (23), nail alterations associated with dermatoses (16), onychocryptosis (11), and paronychia (10). Toenails were involved in 54 patients, fingernails in 25, and both in 21 patients. Twenty nails were involved in 21 patients. A high prevalence of nail alterations was found in pediatric dermatology patients, some of which were nonspecific, while others provided important diagnostic clues.

Hypoxic pulmonary vasoconstriction increases during endotoxemia in the perfused rat lung.

BACKGROUND: Several investigations have studied hypoxic pulmonary vasoconstriction (HPV) during endotoxemia, as in this situation there is an increase in the activation of the inducible nitric oxide synthases, producing a greater liberation of nitric oxide (NO) in the pulmonary vessels. However, these studies yielded conflicting or at times contradictory results, since reference has been made to both enhancement and inhibition of HPV. Our objective was to determine the effect of hypoxia on the isolated blood-perfused lung of endotoxemic rats, and to give at least a partial explanation of its production mechanism. METHODS: Pulmonary arterial pressure (PAP) was measured in a blood-perfused lung preparation from Wistar rats in normoxia (O2, 20%; CO2, 5%; N, 75%) and hypoxia (O2, 2%; CO2, 5%; N, 93%). There were three experimental protocols. We studied the effect of hypoxia in a control group (CG) and an endotoxemic group (EG). Second, we studied the effect of hypoxia in endotoxemic rats pretreated with indomethacin (E+IG). Third, we assessed the effect of two inhibitors of NO synthesis: N-methyl-l-arginine (NMLA) and methylene blue (MB) on two subgroups of groups CG (CGnmla and CGmb) and EG (EGnmla and EGmb). With the exception of the CG, all specimens were pretreated with a 20-mg/kg intraperitoneal injection of Escherichia coli lipopolysaccharide. RESULTS: DeltaPAP elicited by hypoxia in the EG group (15.90 +/- 4.75 mm Hg) was 2.30 times higher than in the CG (6.89 +/- 1.96 mm Hg). In the E+IG group, hypoxia produced a DeltaPAP of 15.20 +/- 3.56 mm Hg, similar to that in the EG. The addition of MB in the EGmb subgroup increased base PAP during normoxia from 19.1 +/- 1.23 mm Hg to 32.2 +/- 6.1 mm Hg (p < 0.05). CONCLUSION: In an isolated-perfused rat model, E. coli lipopolysaccharide (20 mg/kg) significantly increased HPV. This response is maintained over time. Inhibition of NO release by hypoxia may be responsible for the enhanced HPV after endotoxin.

Bart syndrome: the congenital localized absence of skin may follow the lines of Blaschko. Report of six cases.

Three cutaneous manifestations are characteristic of Bart syndrome: congenital localized absence of skin (CLAS), mucocutaneous blistering, and nail abnormalities. Six cases of Bart syndrome are herein reported. Localized absence of skin is present at birth, particularly on the anterior aspects of the lower extremities and dorsa of the feet. Physical trauma in utero has been proposed as a mechanism to explain the denuded areas on the limbs. The recurrent, highly similar pattern of the congenital defect in regard to location and clinical appearance in our patients and in most of the reported cases strongly suggests that trauma is too simplistic an explanation. Because of the observed bilateral and symmetric distribution of denuded areas in an S-shaped broad band, their sharply demarcated borders, the involvement of the toe webs, and the frequent similar involvement of the soles, we suggest that congenital localized absence of skin in Bart syndrome may follow the lines of Blaschko.

Elejalde syndrome--a melanolysosomal neurocutaneous syndrome: clinical and morphological findings in 7 patients.

BACKGROUND: Silvery hair and severe dysfunction of the central nervous system (neuroectodermal melanolysosomal disease or Elejalde syndrome) characterize this rare autosomal recessive disease. Main clinical features include silver-leaden hair, bronze skin after sun exposure, and neurologic involvement (seizures, severe hypotonia, and mental retardation). Large granules of melanin unevenly distributed in the hair shaft are observed. Abnormal melanocytes and melanosomes and abnormal inclusion bodies in fibroblasts may be present. Differential diagnosis with Chédiak-Higashi syndrome and Griscelli syndrome must be done. OBSERVATIONS: We studied pediatric patients with silvery hair and profound neurologic dysfunction. Immune impairment was absent. Age of onset of neurologic signs ranged from 1 month to 11 years; the signs included severe muscular hypotonia, ocular alterations, and seizures. Mental retardation since the first months of life was noted in 4 cases. Psychomotor development was normal in 3 cases, but suddenly the patients presented with a regressive neurologic process. Four patients died between 6 months and 3 years after the onset of neurologic dysfunction. One patient showed characteristic ultrastructural findings of Elejalde syndrome. CONCLUSIONS: Elejalde syndrome is different from Chédiak-Higashi and Griscelli syndrome and is characterized by silvery hair and frequent occurrence of fatal neurologic alterations. Psychomotor impairment may have 2 forms of presentation: congenital or infantile. Although Elejalde syndrome and Griscelli syndrome are similar, the possibility that they are 2 different diseases, although probably allelic related, is suggested.

[Subarachnoid hemorrhage: electrocardiographic, left ventricular wall motion abnormalities and mortality analysis in 14 cases]. / Hemorragia subaracnoidea: anomalías electrocardiográficas, de la contractilidad del ventrículo izquierdo y análisis de la mortalidad en 14 casos.

BACKGROUND: Electrocardiographic (ECG) changes have been frequently observed in patients with subarachnoid hemorrhage (SAH). Their association with wall motion abnormalities of the left ventricle (LV) have not been well established. PATIENTS AND METHODS: Sixteen patients with SAH were included; 2 patients with previous history of heart disease were subsequently excluded. We studied the neurological damage (Hunt-Hess grading scale), ECG (ST segment, T wave) and echocardiography (LV regional and global contractility) of 14 patients. RESULTS: The ECG was abnormal in 11 patients (T wave: 6 patients; ST segment: 5 patients). Echocardiography showed alterations in 5 patients, all of them with ECG changes (T wave: one patient; ST segment: 4 patients). The neurological lesion was higher in patients with abnormal echocardiogram (Hunt-Hess mean grade: 4.6 vs 2.7 in patients with normal echocardiogram; p < 0.001). An intravenous infusion of dobutamine in a 23 years old male, improved the LV ejection fraction, which was severely depressed at baseline. Mortality, in all cases secondary to the neurological damage, was higher in patients with abnormal ECG (91% vs 0% in patients with normal ECG; p = 0.01) and when the echocardiogram showed alterations although in the last case no statistical differences were found. CONCLUSIONS: Echocardiography abnormalities in patients with SAH and without previous history of heart disease are more frequently related to ECG changes affecting ST segment, and to a higher cerebral damage.

[The serological diagnosis of HIV-1 in samples of dried blood on filter paper by the HIV-1 DAVIH Dot system]. / Diagnóstico serológico del VIH-1 en muestras de sangre seca en papel de filtro por el sistema DAVIH Dot VIH-1.

Dried blood specimens spotted on filter paper were evaluated by the HIV-1 DAVIH Dot system from DAVIH Laboratories (Havana, Cuba). The samples used, 103 positive and 105 negative, were previously confirmed by DAVIH Blot from DAVIH Laboratories. In order to use the dried blood on filter paper some modifications were made to the original procedure regarding the times of incubation of the samples and conjugate, and the agitation in both stages. Relative sensitivity and specificity of 100 and 99.05%, respectively, were attained.

Carbon monoxide inhibits hypoxic pulmonary vasoconstriction in rats by a cGMP-independent mechanism.

Hypoxia activates erythropoietin-producing cells, chemoreceptor cells of the carotid body and pulmonary artery smooth muscle cells (PSMC) with a comparable arterial PO2 threshold of some 70 mmHg. The inhibition by CO of the hypoxic responses in the two former cell types has led to the proposal that a haemoprotein is involved in the detection of the PO2 levels. Here, we report the effect of CO on the hypoxic pulmonary vasoconstriction (HPV). Pulmonary arterial pressure (PAP) was measured in an in situ, blood-perfused lung preparation. PAP in normoxia (20% O2, 5% CO2) was 15.2+/-1.8 mmHg, and hypoxia (2% O2, 5% CO2) produced a DeltaPAP of 6.3+/-0.4 mmHg. Addition of 8% or 15% CO to the hypoxic gas mixture reduced the DeltaPAP by 88.3+/-2.7% and 78.2+/-6.1% respectively. The same levels of CO did not affect normoxic PAP nor reduced the DeltaPAP produced by angiotensin II. The effect of CO was studied after inhibition of the NO-cyclic guanosine monophosphate (cGMP) cascade with N-methyl-l-arginine (5.10(-5) M) or methylene blue (1.4.10(-4) M). It was found that both inhibitors more than doubled the hypoxic DeltaPAP without altering the effectiveness of CO to inhibit the HPV. In in vitro experiments we verified the inhibition of guanylate cyclase by measuring the levels of cGMP in segments of the pulmonary artery. Cyclic GMP levels were 1.4+/-0.2 (normoxia), 2.5+/-0.3 (hypoxia) and 3.3+/-0.5 pmole/mg tissue (hypoxia plus 8% CO); sodium nitroprusside increased normoxic cGMP levels about fourfold. Methylene blue reduced cGMP levels to less than 10% in all cases, and abolished the differences among normoxic, hypoxic and hypoxic plus CO groups. It is concluded that CO inhibits HPV by a NO-cGMP independent mechanism and it is proposed that a haemoprotein could be involved in O2-sensing in PSMC.

Therapeutic efficacy of interferon alfa-2b in infants with life-threatening giant hemangiomas.

BACKGROUND: Because of their size and the possibility of complications, giant hemangiomas represent a therapeutic challenge. Various forms of treatment have been used, with variable results, including surgery, embolization, lasers, pentoxifylline, and corticosteroids. Interferon alfa has been used successfully to treat life-threatening hemangiomas, possibly by means of its antiangiogenic activity. OBSERVATIONS: We treated 7 infants with organ-interfering and/or life-threatening giant hemangiomas with subcutaneous injections of 3 million U/m2 per day of interferon alfa-2b during the first month and subsequently every 48 to 72 hours, depending on the evolution in each case. The treatment lasted from 3 to 12 months. In 2 patients, interferon alfa-2b was administered while prednisone therapy was being tapered. In all 7 patients, there was considerable reduction of the volume of the hemangiomas and remission of their complications. All patients presented with fever, neutropenia, and an increase in serum aminotransferase levels. The patients who received interferon alfa-2b and prednisone seemed to improve at a faster rate. CONCLUSIONS: Interferon alfa-2b is a good option for the treatment of patients with steroid-resistant, organ-interfering and/or life-threatening giant hemangiomas. In our experience, the adverse effects were transient and minor and did not require the interruption of the treatment.