Optimized quantification of intra-host viral diversity in SARS-CoV-2 and influenza virus sequence data.

High error rates of viral RNA-dependent RNA polymerases lead to diverse intra-host viral populations during infection. Errors made during replication that are not strongly deleterious to the virus can lead to the generation of minority variants. However, accurate detection of minority variants in viral sequence data is complicated by errors introduced during sample preparation and data analysis. We used synthetic RNA controls and simulated data to test seven variant-calling tools across a range of allele frequencies and simulated coverages. We show that choice of variant caller and use of replicate sequencing have the most significant impact on single-nucleotide variant (SNV) discovery and demonstrate how both allele frequency and coverage thresholds impact both false discovery and false-negative rates. When replicates are not available, using a combination of multiple callers with more stringent cutoffs is recommended. We use these parameters to find minority variants in sequencing data from SARS-CoV-2 clinical specimens and provide guidance for studies of intra-host viral diversity using either single replicate data or data from technical replicates. Our study provides a framework for rigorous assessment of technical factors that impact SNV identification in viral samples and establishes heuristics that will inform and improve future studies of intra-host variation, viral diversity, and viral evolution. IMPORTANCE When viruses replicate inside a host cell, the virus replication machinery makes mistakes. Over time, these mistakes create mutations that result in a diverse population of viruses inside the host. Mutations that are neither lethal to the virus nor strongly beneficial can lead to minority variants that are minor members of the virus population. However, preparing samples for sequencing can also introduce errors that resemble minority variants, resulting in the inclusion of false-positive data if not filtered correctly. In this study, we aimed to determine the best methods for identification and quantification of these minority variants by testing the performance of seven commonly used variant-calling tools. We used simulated and synthetic data to test their performance against a true set of variants and then used these studies to inform variant identification in data from SARS-CoV-2 clinical specimens. Together, analyses of our data provide extensive guidance for future studies of viral diversity and evolution.

Optimized Quantification of Intrahost Viral Diversity in SARS-CoV-2 and Influenza Virus Sequence Data.

High error rates of viral RNA-dependent RNA polymerases lead to diverse intra-host viral populations during infection. Errors made during replication that are not strongly deleterious to the virus can lead to the generation of minority variants. However, accurate detection of minority variants in viral sequence data is complicated by errors introduced during sample preparation and data analysis. We used synthetic RNA controls and simulated data to test seven variant calling tools across a range of allele frequencies and simulated coverages. We show that choice of variant caller, and use of replicate sequencing have the most significant impact on single nucleotide variant (SNV) discovery and demonstrate how both allele frequency and coverage thresholds impact both false discovery and false negative rates. We use these parameters to find minority variants in sequencing data from SARS-CoV-2 clinical specimens and provide guidance for studies of intrahost viral diversity using either single replicate data or data from technical replicates. Our study provides a framework for rigorous assessment of technical factors that impact SNV identification in viral samples and establishes heuristics that will inform and improve future studies of intrahost variation, viral diversity, and viral evolution. IMPORTANCE: When viruses replicate inside a host, the virus replication machinery makes mistakes. Over time, these mistakes create mutations that result in a diverse population of viruses inside the host. Mutations that are neither lethal to the virus, nor strongly beneficial, can lead to minority variants that are minor members of the virus population. However, preparing samples for sequencing can also introduce errors that resemble minority variants, resulting in inclusion of false positive data if not filtered correctly. In this study, we aimed to determine the best methods for identification and quantification of these minority variants by testing the performance of seven commonly used variant calling tools. We used simulated and synthetic data to test their performance against a true set of variants, and then used these studies to inform variant identification in data from clinical SARS-CoV-2 clinical specimens. Together, analyses of our data provide extensive guidance for future studies of viral diversity and evolution.

Quiste epidermoide en región parotídea. Reporte de caso y revisión de la literatura / Epidermoid cyst in the parotid region. A case report and review of the literature

Los quistes epidermoides son lesiones quísticas benignas que se desarrollan de componentes epiteliales anormales de tejido ectodérmico formado durante el periodo fetal (congénito) o por epitelio implantado después de una cirugía o trauma (adquirido). El quiste epidermoide es considerado una lesión benigna que afecta la región del pericráneo, cara, cuello, espalda y torso, el 7% de estos quistes ocurren en la región de la cabeza y el cuello y solo el 1,6% representa la cavidad oral. A continuación, se presenta un caso clínico con diagnóstico histopatológico de quiste epidermoide en la región parotídea, el cual no presentó un compromiso del parénquima glandular, el cual fue tratado mediante escisión quirúrgica completa, sin alteración o daño al nervio facial, con seguimiento postoperatorio de tres años sin recidiva.

Epidermoid cysts are benign cystic lesions that develop from abnormal epithelial components of ectodermal tissue formed during the fetal period (congenital) or from epithelium implanted after surgery or trauma (acquired). The epidermoid cyst is considered a benign lesion that usually affects the scalp, face, neck, back, and torso. 7% of these cysts occur in the head and neck, whereas the oral cavity represents only 1.6%. A clinical case is presented with a histopathological diagnosis of an epidermoid cyst in the parotid region, which did not present compromise of the glandular parenchyma, that was treated with complete surgical excision, without alteration or damage to the facial nerve, with a three-year postoperative follow-up without recurrence.

Spatiotemporal association between the mite Brevipalpus yothersi and Citrus leprosis virus C in orange orchards.

Citrus leprosis virus C (CiLV-C) is an economically important pathogen and the main causative agent of leprosis disease in citrus orchards. The main vector of this disease, the mite Brevipalpus yothersi, is widely distributed in Mexican orchards on a wide range of citrus species. Despite the importance of both the virus and the mite, field studies recording their occurrence and co-occurrence are practically non-existent. We systematically sampled orange orchards for both CiLV-C and B. yothersi throughout the year. The distribution of the CiLV-C and B. yothersi was evaluated on each sampling occasion and their spatiotemporal associations were determined. Specifically, 100-112 orange trees, distributed in 18 rows (five or six trees per row), were sampled monthly between March 2017 and February 2018 (11 sampling dates). Twenty leaves per tree were sampled on each occasion. The number of mites per tree and the percentage of leaves per tree with disease symptoms were recorded. On each sampling occasion, spatiotemporal associations between mites and disease were determined using the Spatial Analysis by Distance Indices (SADIE) method. CiLV-C and B. yothersi were identified using molecular methods. Throughout the study, the distribution of CiLV-C was aggregated and the distribution of B. yothersi was random. No association was found between the virus and the mite on any of the sampling dates. In total, 173 mites were collected, but only 43 mites were found to be carrying CiLV-C. The reason for this lack of association between the virus and the mite, as well as the impact of our findings on the epidemiology of the disease in orange orchards, are discussed.

Degradation of Chloramphenicol in Synthetic and Aquaculture Wastewater Using Electrooxidation.

Chloramphenicol (CAP) is a broad-spectrum antibiotic widely used in animal farming and aquaculture industries. Despite its ban in many countries around the world, it is still used in several developing countries, with harmful effects on the surrounding aquatic environment. In this study, an electrooxidation process using a Ti/PbO anode was used to investigate the degradation of CAP in both synthetic solution and real aquaculture wastewater. A central composite design was used to determine the optimum conditions for CAP removal. Current intensity and treatment time had the most impact on the CAP removal. These two factors accounted for ∼90% of CAP removal. The optimum conditions found in this study were current intensity of 0.65 A, treatment time of 34 min, and CAP initial concentration of 0.5 mg L. Under these conditions, 98.7% of CAP removal was achieved with an energy consumption of 4.65 kW h m. The antibiotic was not present in the aquaculture wastewater, which received 0.5 mg L of CAP and was treated (by electrooxidation) under the optimum conditions. A complete removal of CAP was obtained after 34 min of treatment. According to these results, electrooxidation presents an option for the removal of antibiotics, secondary compounds, and other organic and inorganic compounds from solution.

Molecular and biochemical characterization of natural and recombinant phosphoglycerate kinase B from Trypanosoma rangeli.

T. rangeli epimastigotes contain only a single detectable phosphoglycerate kinase (PGK) enzyme in their cytosol. Analysis of this parasite's recently sequenced genome showed a gene predicted to code for a PGK with the same molecular mass as the natural enzyme, and with a cytosolic localization as well. In this work, we have partially purified the natural PGK from T. rangeli epimastigotes. Furthermore, we cloned the predicted PGK gene and expressed it as a recombinant active enzyme. Both purified enzymes were kinetically characterized and displayed similar substrate affinities, with KmATP values of 0.13 mM and 0.5 mM, and Km3PGA values of 0.28 mM and 0.71 mM, for the natural and recombinant enzyme, respectively. The optimal pH for activity of both enzymes was in the range of 8-10. Like other PGKs, TrPGK is monomeric with a molecular mass of approximately 44 kDa. The enzyme's kinetic characteristics are comparable with those of cytosolic PGK isoforms from related trypanosomatid species, indicating that, most likely, this enzyme is equivalent with the PGKB that is responsible for generating ATP in the cytosol of other trypanosomatids. This is the first report of a glycolytic enzyme characterization from T. rangeli.

Evaluación de l calidad microbiológica del agu para consumo y del agua residuual en una población de bogotá (Colombaa) / Evaluatin of thee microbial quality of dinking water and wastewater in one population of bogota (Colombia)

En Colombia el acceso al agua potable y a sistemas de saneamiento no están garantizados para buena parte de la población, por lo que el consumo de agua contaminada genera enfermedades de origen hídrico. La alternativa más utilizada para el acceso al agua potable es su almacenamiento dentro de las viviendas y la improvisación de sistemas de alcantarillado que generalmente se encuentran a cielo abierto. Objetivo: Evaluar la calidad microbiológica del agua utilizada para consumo y el agua residual cercana a las viviendas de una población en desplazamiento y su relación con la salud de la población. Materiales y Métodos: Se recolectaron 36 muestras de agua para consumo almacenadas en diferentes tipos de recipientes y de grifos, en caso de estar instalados. Adicionalmente se recolectaron 15 muestras de agua residual de forma aleatoria en un asentamiento ilegal compuesto en su gran mayoría por población desplazada. Para evaluar la calidad microbiológica del agua se analizaron como indicadores de contaminación de origen fecal E. coli, C. perfringens y colífagos somáticos. Simultáneamente se llevó a cabo la aplicación de encuestas de morbilidad sentida con el fin de establecer la posible relación entre las condiciones de vida de los habitantes, la calidad del agua y la percepción del estado de salud. Resultados y Conclusiones: En 14 de las 36 casas seleccionadas y en las 15 de redes de alcantarillado a cielo abierto, se encontró contaminación de origen fecal. La encuesta de morbilidad realizada muestra cómo la calidad del agua y las condiciones de vida pueden influir en la salud de la población. La OMS considera que el agua para consumo debe estar libre de microorganismos que afecten la salud humana, para lo cual es importante su tratamiento, almacenamiento y aislamiento de redes de aguas residuales.

In Colombia access to drinking water and sanitation are not guaranteed for the majority of the population, reason why the consumption of contaminated water generates water-borne diseases. The most commonly used alternative to access drinking water is its storage in homes and the improvisation of sewerage systems typically found outdoors. Objective: To evaluate microbiological quality of drinking water and wastewater near the homes of displaced populations and its relationship with the community's health. Materials and Methods: Thirty-six (36) samples of drinking water for consumption stored in different types of containers and taps were collected where these were installed. Additionally 15 samples of wastewater were collected randomly in an illegal settlement, where most of the inhabitants were displaced persons. E. coli, C. perfringens and somatic coliphages were examined as fecal contamination indicators for microbiological water quality assessment. Simultaneously, morbidity surveys were carried out to establish the possible relationship between the inhabitants' living conditions, water quality and health status perception. Results and Conclusions: Contamination of fecal origin was found in 14 out of the 36 selected houses and in 15 outdoors sewerages. The conducted morbidity survey shows how water quality and living conditions can influence the health of the population. WHO estimates that drinking water should be free from microorganisms that affect human health, reason why water treatment, proper storage and isolation of residual water are important facts to be considered.

Prevalencia de Listeria monocytogenes en carnes y derivados de la industria porcícola colombiana / Prevalence of Listeria monocytogenes in pork-meat and other processed products from the Colombian swine industry

Objective. To determine the prevalence of L. monocytogenes in pork carcasses, meat cuts, and meat products (“chorizo”, sausage and ham). Materials and methods. Stratified sampling was implemented in meat-processed products. We analyzed 566 (37%) carcasses, 472 (31%) meat cuts, and 481, (32%) meat-processed products, distributed as follows: 169 (11%) sausage, 163 (11%) ham, and 149 (10%) “chorizo”, for a total of 1519 (100%) samples in a period of 18 months. The samples were processed using the ISO-17604, ISO-11290-1 and the USDA/FSIS (MLG-8.03) methods. Genus and species were confirmed by multiplex-PCR. Results. We obtained isolates of L. monocytogenes from 21 carcasses (10%), 160 (76%) from meat deboning, 10 (5%) from ham, 6 (3%) from “chorizo”, and 13 (6%) from sausage. The prevalence found was 3.7% and 33.9% in carcasses and meat deboning respectively. The prevalence in the meat-processed products was 4.03% in “chorizo”, 6.13% in ham and 7.69% in sausage. The overall prevalence of L. monocytogenes in the study was 13.82%. Conclusions. We found L. monocytogenes in different products analyzed, with particular interest in ham and sausage since both are consumed without previous heat treatment.

QEEG norms for the first year of life.

BACKGROUND: QEEG allows a more objective evaluation of cerebral electrical activity as well as the production of topographical maps for easier comprehension. Here we have developed qEEG norms for the first year of life using methods previously published for other age ranges, including for example, regression for Gausssianity before Z transformation. These norms constitute a non-invasive and low cost tool for the functional evaluation of the infant's brain. RESULTS: Developmental equations were obtained from 101 healthy infants recording at spontaneous quiet sleep stage II. Polynomial regression equations, with age as independent variable, were calculated for full Broad Band Spectral Parameters (BBSP) using the Least Squares technique. Interpolated maps of the BBSP values or their Z transformation were constructed for linked-ear reference, average reference and Laplacian montages. All montages produced similar tendency curves and Z maps of absolute and relative power, and mean frequency at all frequency bands. The norms obtained were validated against an independent group of 50 healthy infants and some pathological cases. 91-98% of cases were well classified as normal across all measures and montages. To exemplify, two pathological cases are presented of which their qEEG maps show resemblance to CT and MRI. CONCLUSIONS: These qEEG norms are highly useful as an aid to visual interpretation and for the study of pathology further evolution as well as for assessment of infants showing brain risk factors. To our knowledge this is the first normative qEEG study for the initial year of life with such large sample and validation-group.

Cryptosporidium parvum in diarrheic calves detected by microscopy and identified by immunochromatographic and molecular methods.

Cryptosporidium is an important protozoan parasite that causes diarrhea in neonates and young bovines. The objective of the present study was to determine the frequency of Cryptosporidium infection in animals of dairy farms of the Metropolitan Region (Santiago), Chile. Fecal samples of 205 newborn calves with diarrhea were studied and used for comparing the efficiency of two microscopic staining methods for diagnosis of the parasite, the auramine (AU) and a modified Ziehl-Neelsen (ZN) procedure. Out of the 205 fecal samples, we detected oocysts in 115 (56.1%) with AU and 102 (49.8%) with ZN. Comparison of results obtained with the two microscopic techniques showed significant difference (p<0.05), AU being more sensitive. On the other hand, concordance between the two methods was almost perfect (kappa value of 0.83). The results with these two operator dependent methods were confirmed using an operator independent immunochromatographic (IC) method. The IC method also enabled us to determine the identity of the parasite species as that of Cryptosporidium parvum. Identification of the parasite species was further corroborated by performing a Cryptosporidium species-specific polymerase chain reaction (PCR) test on few samples taken at random. Overall, the results showed a high number of infected animals suggesting the parasite C. parvum as a major parasitic disease agent of neonatal calves with diarrhea in dairy farms of the Metropolitan Region (Santiago) of Chile.

Ectopic pregnancy early diagnosis markers.

Ectopic pregnancy (EP) is a high-risk medical condition with an incidence of 1.9% in reported pregnancies, and has proven to be the most common cause of pregnancy-related deaths in the first trimester. The clinical symptoms can mimic non-EP conditions, thus creating a challenge for developing diagnostic criteria and new diagnostic tools. Early diagnosis of ectopic pregnancy is essential in order to minimize the morbidity and to assess the need for urgent surgical intervention. Currently, ultrasound and serum biomarkers are used by clinicians for early detection and diagnosis. This review summarizes and comments on the available literature on the various markers including their utility and their statistical parameters.

Provocative test with propofol: experience in patients with cerebral arteriovenous malformations who underwent neuroendovascular procedures.

BACKGROUND AND PURPOSE: Provocative testing before AVM embolization has been shown to be a predictor of a successful endovascular treatment without neurologic deficits. Propofol has been used previously as an alternative agent in Wada testing with adequate results. The purpose of this study was to show our experience with the use of propofol as a safe and effective alternative to barbiturate provocative testing in AVM embolization procedures. MATERIALS AND METHODS: A series of 20 patients, undergoing 38 embolization sessions, was treated for cerebral AVMs between November 2007 and February 2009 by endovascular methods. All patients were treated under conscious sedation. Pre-embolization neurologic assessment was performed with provocative testing by using propofol at 7-mg doses by an intra-arterial route after microcathether placement in or near the AVM nidus. RESULTS: Among these 20 patients, 3 developed transient neurologic deficits after provocative testing, precluding initial or further embolization. One of the patients passing the provocative test developed slight paresis as a result of embolization with n-BCA, resulting in a PPV of 97%. CONCLUSIONS: Propofol use during provocative testing in AVM embolization procedures represents an effective alternative to barbiturate testing and can have a positive impact in improving safety under sedation.

Estimating the impact of Trypanosoma evansi infection (surra) on buffalo population dynamics in southern Philippines using data from cross-sectional surveys.

Despite the widespread problem with surra (Trypanosoma evansi) in livestock, there are no published studies on its impact on host populations, probably because of the large financial and time cost involved in performing longitudinal studies. During 2002-6, a cross-sectional survey for T. evansi infection involving 1732 buffaloes from 71 villages in southern Philippines was carried out. Other livestock animals (horses, cattle and goats) in every surveyed village were also tested for infection with T. evansi but domestic buffaloes were the primary survey target. Seroprevalence ranged from 6% to 21% and 13% to 100% for buffaloes in low and high risk areas, respectively. Key demographic parameters were estimated from the age structured distributions of the sampled buffalo population for each sex. All areas were dominated by females (69%) and the annual calving rate for areas of 100% and low seroprevalence was 15% and 47%, respectively. Males were removed at a relatively high annual rate of 27% in all areas. In the main reproductive years (4-10) female removal/mortality was <1% and 10% for low and high risk areas, respectively. Older females were removed/died at a rate similar to males regardless of area. In high risk areas there were consistently more 2-year than 1-year old females and the reverse was true for the low risk areas. This implies that females were imported to the high risk areas for breeding. By assuming a stable age structure and similar size populations in each area, it was estimated that 28% of female calves need to be moved from low to high risk areas to maintain the observed age structure. In high risk areas, surra imposes significant financial losses due to reduced fertility, high mortality/removal rate and the necessity to import replacement buffaloes.

Models for Trypanosoma evansi (surra), its control and economic impact on small-hold livestock owners in the Philippines.

Simple demographic and infectious disease models of buffaloes and other domestic hosts for animal trypanosomosis (surra) caused by Trypanosoma evansi were developed. The animal models contained deterministic and stochastic elements and were linked to simulate the benefit of control regimes for surra in village domestic animal populations in Mindanao, Philippines. The impact of the disease on host fertility and mortality were key factors in determining the economic losses and net-benefit from the control regimes. If using a high (99%) efficacy drug in surra-moderate to high risk areas, then treating all animals twice each year yielded low prevalence in 2 years; targeted treatment of clinically sick animals, constantly monitored (monthly), required 75% fewer treatments but took longer to reach a low prevalence than treating all animals twice each year. At high drug efficacy both of these treatment strategies increased the benefit over untreated animals by 81%. If drug efficacy declined then the benefit obtained from twice yearly treatment of all animals declined rapidly compared with regular monitoring and targeting treatment to clinically sick animals. The current control regimen applied in the Philippines of annual sero-testing for surra and only treating sero-positive animals provided the lowest net-benefit of all the control options simulated and would not be regarded as effective control. The total net-benefit from effective surra control for a typical village in a moderate/high risk area was 7.9 million pesos per annum (US $158,000). The value added to buffaloes, cattle, horses, goats/sheep and pigs as a result of this control was US $88, $84, $151, $7, $114 per animal/year, respectively.

Comparison of bronchoscopic bronchoalveolar lavage vs blind lavage with a modified nasogastric tube in the etiologic diagnosis of ventilator-associated pneumonia.

OBJECTIVE: Our objective was to compare the results of a blind lavage vs a bronchoscopic-guided bronchoalveolar lavage for the etiologic diagnosis of ventilator-associated pneumonia (VAP). DESIGN: Prospective study in consecutive patients with high probability of VAP. Every patient underwent both procedures, in a formally randomized fashion. The interpretation of quantitative cultures was done in a blind fashion. SETTING: Single center study, with a 20 bed medical and surgical Intensive Care Unit of the University Hospital in Monterrey, Mexico. PATIENTS: Twenty-five patients with high probability of VAP. INTERVENTIONS: Every patient underwent blind bronchoalveolar lavage with a modified nasogastric tube, and a bronchoscopic-guided bronchoalveolar lavage. RESULTS: Twenty-one patients underwent both procedures. Four patients were excluded due to contamination of the cultures. The quantitative cultures were compared in a paired fashion. Only two patients had discordant cultures. The correlation coefficient between the number of colonies was very high, r=0.90 (95% confidence interval [CI], 0.77-0.96; p=0.0001). CONCLUSIONS: The blind bronchoalveolar lavage with a modified nasogastric tube is a valuable tool for the identification of etiologic agent in VAP, particularly when trained bronchoscopists or the necessary resources for bronchoscopic-guided bronchoalveolar lavage are not readily available.

Comparison of bronchoscopic bronchoalveolar lavage vs blind lavage with a modified nasogastric tube in the etiologic diagnosis of ventilator-associated pneumonia / Comparison of bronchoscopic bronchoalveolar lavage vs blind lavage with a modified nasogastric tube in the etiologic diagnosis of ventilator-associated pneumonia

Objective. Our objective was to compare the results of a blind lavage vs a bronchoscopic-guided bronchoalveolar lavage for the etiologic diagnosis of ventilator-associated pneumonia (VAP). Design. Prospective study in consecutive patients with high probability of VAP. Every patient underwent both procedures, in a formally randomized fashion. The interpretation of quantitative cultures was done in a blind fashion. Setting. Single center study, with a 20 bed medical and surgical Intensive Care Unit of the University Hospital in Monterrey, Mexico. Patients. Twenty-five patients with high probability of VAP. Interventions. Every patient underwent blind bronchoalveolar lavage with a modified nasogastric tube, and a bronchospic-guided bronchoalveolar lavage. Results. Twenty-one patients underwent both procedures. Four patients were excluded due to contamination of the cultures. The quantitative cultures were compared in a paired fashion. Only two patients had discordant cultures. The correlation coefficient between the number of colonies was very high, r = 0.90 (95% confidence interval [CI], 0.77-0.96; p = 0.0001). Conclusions. The blind bronchoalveolar lavage with a modified nasogastric tube is a valuable tool for the identification of etiologic agent in VAP, particularly when trained bronchoscopists or the necessary resources for bronchoscopic-guided bronchoalveolar lavage are not readily available

Objetivo. Nuestro objetivo fue el de comparar los resultados de un lavado ciego frente a un lavado broncoalveolar guiado con broncoscopio para el diagnóstico etiológico de neumonía asociada a ventilador (NAV). Diseño. Estudio prospectivo en pacientes consecutivos con alta probabilidad de NAV. En todos los pacientes se llevaron a cabo ambos procedimientos de manera aleatorizada. La interpretación de los cultivos cuantitativos fue hecha a ciegas. Ámbito. Estudio en un único centro, en una Unidad de Cuidados Intensivos Quirúrgicos con 20 camas del Hospital Universitario de Monterrey, en México. Pacientes. Veinticinco pacientes con alta probabilidad de NAV. Intervenciones. A cada paciente se le realizó un lavado broncoalveolar ciego con una sonda nasogástrica modificada y un lavado broncoalveolar guiado con broncoscopio. Resultados. Se realizaron ambos procedimientos en 21 pacientes. Cuatro fueron excluidos debido a contaminación de los cultivos. Los cultivos cuantitativos fueron comparados en pares. Solo dos pacientes tenían cultivos discordantes. El coeficiente de correlación entre el número de colonias fue muy alto, r = 0,90 (intervalo de confianza [IC] del 95% 0,77-0,96; p = 0,0001). Conclusiones. El lavado broncoalveolar ciego con sonda nasogástrica modificada es una herramienta de mucho valor para la identificación del agente etiológico en NAV, especialmente cuando un broncoscopista experto o los recursos necesarios para lavado broncoalveolar guiado con broncoscopio no están fácilmente disponibles

Evaluation of pediatric patients with vascular malformations managed with endovascular and radiosurgical techniques using a modified Rankin Disability Scale

BACKGROUND: Pre- and postoperative evaluation of the pediatric patient with a cerebrovascular malformation can be cumbersome. This may be due to several factors, including age and ability to verbalize. Functional evaluation scales have been devised, yet application to a retrospective study, where information can be limited, may not be possible. Simpler scales, serving the purpose of functional description and categorization would be beneficial in these cases. METHODS: Between December 1997 and December 2003, 24 patients between the ages of 4 months to 17 years old underwent endovascular treatment for cerebrovascular lesions at our institution. The majority of the arteriovenous malformation cases underwent further radiosurgical treatment. Mean follow-up period from the time of the last endovascular or radiosurgical intervention was 22 months. A pediatric modification of the Rankin Disability Scale was used for evaluation of pre-procedural and post-procedural functional status. RESULTS: Combined embolization/radiosurgical approach had 4% mortality and 4% morbidity rates. This combined technique achieved a 46% cure in a variety of pediatric vascular anomalies. Overall improvement in disability using the pediatric modification of the Rankin Scale was noted for all of the cases, and a tendency for improvement was noted in the arteriovenous malformation subgroup though not statistically significant, p = 0.0547. CONCLUSIONS: These results indicate that a pediatric modification of the Rankin Disability Scale can be used for functional evaluation in this population. Although other functional evaluation scales are available and validated, using a Rankin Disability Scale modification is straightforward, and it can provide functional categorization in retrospective studies.

Human pseudoterranovosis, an emerging infection in Chile.

Fifteen cases of human pseudoterranovosis are reported for Chile, representing an emerging parasitic infection in this country caused by larvae of the nematode Pseudoterranova sp. Our observations also included an outbreak of pseudoterranovosis in 3 of 4 individuals who shared the same raw fish dish (cebiche). Most of the cases occurred in adult patients. The main source of infection was from consumption raw or fried marine fish, including hakes (Merluccius australis or Merlucciuts gayi), pomfret (Brama australis), Inca scad (Trachurus murphvi), and corvina (Cilus gilberti). Seasonal distribution showed most of the cases to occur in fall and spring. Parasite larvae were isolated from the mouths of most of the patients after they reported a pharyngeal tickling sensation, coughing, vomiting, or a foreign body in the mouth or throat.

Microsurgical considerations of the anterior spinal and the anterior-ventral spinal arteries.

BACKGROUND: There are few data describing the microanatomy of the anterior-ventral spinal (AVSA) and anterior spinal arteries (ASA) and discussing their clinical and surgical implications. We describe the anatomical features of this arterial complex, and highlight their use when planning and performing surgical approaches to lesions involving the ventral aspect of the medulla and the foramen magnum. METHOD: The microsurgical anatomy and branching pattern of the AVSA and the ASA from fifty human cadaver brain stems is described using a surgical microscope. RESULTS: We found one anterior-ventral spinal artery at each side in 30 of the brain stems (60%). The ASA was a direct branch emerging from the left vertebral artery (VA) in 15 (30%), from the right VA in 4 (8%), and from the basilar artery (BA) in one brain stem (2%). The previously described as "typical pattern" of the junction of the AVS arteries from both sides, was observed only in 9 brain stems (18%). The anterior communicating spinal artery (ACoSA) was observed in 15 brain stems (30%). Also multiple ACoS arteries were described in one brain stem. Both, the AVSA and the ASA were observed to send long circumferential branches that supplied irrigation to the olive in 42 (84%) brain stems. CONCLUSIONS: This anatomical study gives important information for a better understanding of the clinical picture of ischemic lesions of the brain stem, such as the medial medullary syndrome, and highlights the remarkable role of the AVSA and ASA as anatomical landmarks during the surgical approaches to lesions involving the ventral aspect of the medulla and the foramen magnum.

Cirugía de salvamento de extremidad: el cirujano vascular versus la amputación mayor / Limb salvage surgery: the vascular surgeon versus major amputation

Este trabajo prospectivo muestra cómo entre marzo de 2001 y mayo de 2004 se manejaron siete pacientes que consultaron al Hospital de San José y la Clínica Fundadores en la Ciudad de Bogotá, Colombia, con lesiones isquémicas en el pie secundarias a oclusión aterosclerótica de las arterias infrapoplíteas. Dos de ellos cursaron con insuficiencia renal crónica, cuatro eran diabéticos y uno fumador durante varios años. El examen físico reveló lesiones isquémicas localizadas en el pie y pulso poplíteo adecuado con ausencia de pedio y tibial posterior. A todos se les realizó estudio arteriográfico mediante técnica de Seldinger, en el cual se confirmó oclusión de las arterias infrapoplíteas. Todos fueron llevados a exploración quirúrgica bajo anestesia regional, encontrando en cuatro de ellos buen lecho receptor a nivel de la arteria pedia, por lo que se les realizó injerto poplíteo-pedio con safena invertida, y en los tres restantes buen lecho a nivel de la arteria tibial posterior, por lo que se les practicó injerto poplíteo-tibial también con safena invertida. Después se procedió a desbridamiento de las áreas necrosadas. El seguimiento postoperatorio mostró que en los pacientes a los que se realizó injerto poplíteo-tibial hubo fracaso de los mismos, dos por infección del injerto y otro por oclusión recurrente. En ninguno de ellos se logró cicatrización de las lesiones del pie y por último uno requirió amputación infracondílea y dos supracondílea. En aquellos en los que se revascularizó la arteria pedia, se apreció permeabilidad adecuada del injerto con una cicatrización total de las áreas desbridadas al cabo de 90 días con recuperación de la marcha y funcionalidad total de la extremidad. Se concluye que en estos enfermos se debe siempre intentar algún procedimiento de revascularización y es la exploración quirúrgica la que en últimas define esta posibilidad, que si bien no siempre es efectiva, permite evitar amputaciones mayores en un número importante de casos, lo que se traduce en menor incapacidad laboral y mejor calidad de vida.