Solid-State Single-Molecule Sensing with the Electronic Life-Detection Instrument for Enceladus/Europa (ELIE).

Growing evidence of the potential habitability of Ocean Worlds across our solar system is motivating the advancement of technologies capable of detecting life as we know it-sharing a common ancestry or physicochemical origin with life on Earth-or don't know it, representing a distinct emergence of life different than our one known example. Here, we propose the Electronic Life-detection Instrument for Enceladus/Europa (ELIE), a solid-state single-molecule instrument payload that aims to search for life based on the detection of amino acids and informational polymers (IPs) at the parts per billion to trillion level. As a first proof-of-principle in a laboratory environment, we demonstrate the single-molecule detection of the amino acid L-proline at a 10 µM concentration in a compact system. Based on ELIE's solid-state quantum electronic tunneling sensing mechanism, we further propose the quantum property of the HOMO-LUMO gap (energy difference between a molecule's highest energy-occupied molecular orbital and lowest energy-unoccupied molecular orbital) as a novel metric to assess amino acid complexity. Finally, we assess the potential of ELIE to discriminate between abiotically and biotically derived α-amino acid abundance distributions to reduce the false positive risk for life detection. Nanogap technology can also be applied to the detection of nucleobases and short sequences of IPs such as, but not limited to, RNA and DNA. Future missions may utilize ELIE to target preserved biosignatures on the surface of Mars, extant life in its deep subsurface, or life or its biosignatures in a plume, surface, or subsurface of ice moons such as Enceladus or Europa. One-Sentence Summary: A solid-state nanogap can determine the abundance distribution of amino acids, detect nucleic acids, and shows potential for detecting life as we know it and life as we don't know it.

Assessment of Purity, Functionality, Stability, and Lipid Composition of Cyclofos-nAChR-Detergent Complexes from Torpedo californica Using Lipid Matrix and Macroscopic Electrophysiology.

The main objective of the present study was to find detergents that can maintain the functionality and stability of the Torpedo californica nicotinic acetylcholine receptor (Tc-nAChR). We examined the functionality, stability, and purity analysis of affinity-purified Tc-nAChR solubilized in detergents from the Cyclofos (CF) family [cyclofoscholine 4 (CF-4), cyclofoscholine 6 (CF-6), and cyclofloscholine 7 (CF-7)]. The functionality of the CF-Tc-nAChR-detergent complex (DC) was evaluated using the Two Electrode Voltage Clamp (TEVC) method. To assess stability, we used the florescence recovery after photobleaching (FRAP) in Lipidic Cubic Phase (LCP) methodology. We also performed a lipidomic analysis using Ultra-Performance Liquid Chromatography (UPLC) coupled to electrospray ionization mass spectrometry (ESI-MS/MS) to evaluate the lipid composition of the CF-Tc-nAChR-DCs. The CF-4-Tc-nAChR-DC displayed a robust macroscopic current (- 200 ± 60 nA); however, the CF-6-Tc-nAChR-DC and CF-7-Tc-nAChR-DC displayed significant reductions in the macroscopic currents. The CF-6-Tc-nAChR and CF-4-Tc-nAChR displayed higher fractional florescence recovery. Addition of cholesterol produced a mild enhancement of the mobile fraction on the CF-6-Tc-nAChR. The lipidomic analysis revealed that the CF-7-Tc-nAChR-DC displayed substantial delipidation, consistent with the lack of stability and functional response of this complex. Although the CF-6-nAChR-DC complex retained the largest amount of lipids, it showed a loss of six lipid species [SM(d16:1/18:0); PC(18:2/14:1); PC(14:0/18:1); PC(16:0/18:1); PC(20:5/20:4), and PC(20:4/20:5)] that are present in the CF-4-nAChR-DC. Overall, the CF-4-nAChR displayed robust functionality, significant stability, and the best purity among the three CF detergents; therefore, CF-4 is a suitable candidate to prepare Tc-nAChR crystals for structural studies.

Structural basis of a transcription pre-initiation complex on a divergent promoter.

Most eukaryotic promoter regions are divergently transcribed. As the RNA polymerase II pre-initiation complex (PIC) is intrinsically asymmetric and responsible for transcription in a single direction, it is unknown how divergent transcription arises. Here, the Saccharomyces cerevisiae Mediator complexed with a PIC (Med-PIC) was assembled on a divergent promoter and analyzed by cryoelectron microscopy. The structure reveals two distinct Med-PICs forming a dimer through the Mediator tail module, induced by a homodimeric activator protein localized near the dimerization interface. The tail dimer is associated with ∼80-bp upstream DNA, such that two flanking core promoter regions are positioned and oriented in a suitable form for PIC assembly in opposite directions. Also, cryoelectron tomography visualized the progress of the PIC assembly on the two core promoter regions, providing direct evidence for the role of the Med-PIC dimer in divergent transcription.

Porous Cellulose Acetate/Block Copolymer Membranes for the Recovery of Polyphenolic Compounds from Aquatic Environments.

Polyphenols are natural compounds with strong antioxidant properties synthesized by plants and widely distributed in plant tissues. They compose a broad class of compounds that are commonly employed for multiple applications such as food, pharmaceutical, adhesives, biomedical, agricultural, and industrial purposes. Runoffs from these sources result in the introduction of polyphenols into aquatic environments where they further transform into highly toxic pollutants that can negatively affect aquatic ecosystems and humans. Therefore, the development of extraction and remediation methods for such compounds must be addressed. This study describes the identification and operation of a method to recover polyphenolic compounds from water environments by utilizing membrane-based separation. Composite membranes derived from electrospun cellulose acetate (CA) fibers and diblock copolymer (DiBCP) PEO-b-P4VP were prepared to evaluate the adsorption of polyphenolic compounds from aqueous environments. The highly porous CA fibers were developed using the electrospinning technique, and the fabricated DiBCP/CA membranes were characterized using scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), X-ray photoelectron spectroscopy (XPS), Fourier-transform infrared (FT-IR) spectroscopy, and tensile testing. Finally, the ability of the composite membranes to adsorb the soluble polyphenolic compounds catechol (CAT) and gallic acid (GA), from a wetland environment, was studied via batch adsorption experiments and by solid-phase extraction (SPE). Results revealed a successful recovery of both polyphenols, at concentrations within the parts per million (ppm) range, from the aqueous media. This suggests a novel approach to recover these compounds to prevent their transformation into toxic pollutants upon entrance to water environments.

Structural visualization of de novo transcription initiation by Saccharomyces cerevisiae RNA polymerase II.

Previous structural studies of the initiation-elongation transition of RNA polymerase II (pol II) transcription have relied on the use of synthetic oligonucleotides, often artificially discontinuous to capture pol II in the initiating state. Here, we report multiple structures of initiation complexes converted de novo from a 33-subunit yeast pre-initiation complex (PIC) through catalytic activities and subsequently stalled at different template positions. We determine that PICs in the initially transcribing complex (ITC) can synthesize a transcript of ∼26 nucleotides before transitioning to an elongation complex (EC) as determined by the loss of general transcription factors (GTFs). Unexpectedly, transition to an EC was greatly accelerated when an ITC encountered a downstream EC stalled at promoter proximal regions and resulted in a collided head-to-end dimeric EC complex. Our structural analysis reveals a dynamic state of TFIIH, the largest of GTFs, in PIC/ITC with distinct functional consequences at multiple steps on the pathway to elongation.

Structural insight on assembly-line catalysis in terpene biosynthesis.

Fusicoccadiene synthase from Phomopsis amygdali (PaFS) is a unique bifunctional terpenoid synthase that catalyzes the first two steps in the biosynthesis of the diterpene glycoside Fusicoccin A, a mediator of 14-3-3 protein interactions. The prenyltransferase domain of PaFS generates geranylgeranyl diphosphate, which the cyclase domain then utilizes to generate fusicoccadiene, the tricyclic hydrocarbon skeleton of Fusicoccin A. Here, we use cryo-electron microscopy to show that the structure of full-length PaFS consists of a central octameric core of prenyltransferase domains, with the eight cyclase domains radiating outward via flexible linker segments in variable splayed-out positions. Cryo-electron microscopy and chemical crosslinking experiments additionally show that compact conformations can be achieved in which cyclase domains are more closely associated with the prenyltransferase core. This structural analysis provides a framework for understanding substrate channeling, since most of the geranylgeranyl diphosphate generated by the prenyltransferase domains remains on the enzyme for cyclization to form fusicoccadiene.

Structure of TFIIK for phosphorylation of CTD of RNA polymerase II.

During transcription initiation, the general transcription factor TFIIH marks RNA polymerase II by phosphorylating Ser5 of the carboxyl-terminal domain (CTD) of Rpb1, which is followed by extensive modifications coupled to transcription elongation, mRNA processing, and histone dynamics. We have determined a 3.5-Å resolution cryo-electron microscopy (cryo-EM) structure of the TFIIH kinase module (TFIIK in yeast), which is composed of Kin28, Ccl1, and Tfb3, yeast homologs of CDK7, cyclin H, and MAT1, respectively. The carboxyl-terminal region of Tfb3 was lying at the edge of catalytic cleft of Kin28, where a conserved Tfb3 helix served to stabilize the activation loop in its active conformation. By combining the structure of TFIIK with the previous cryo-EM structure of the preinitiation complex, we extend the previously proposed model of the CTD path to the active site of TFIIK.

Racial and Ethnic Variations in Mortality Rates for Patients Undergoing Maintenance Dialysis Treated in US Territories Compared with the US 50 States.

BACKGROUND AND OBJECTIVES: In the United States mortality rates for patients treated with dialysis differ by racial and/or ethnic (racial/ethnic) group. Mortality outcomes for patients undergoing maintenance dialysis in the United States territories may differ from patients in the United States 50 states. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: This retrospective cohort study of using US Renal Data System data included 1,547,438 adults with no prior transplantation and first dialysis treatment between April 1, 1995 and September 28, 2012. Cox proportional hazards regression was used to calculate hazard ratios (HRs) of death for the territories versus 50 states for each racial/ethnic group using the whole cohort and covariate-matched samples. Covariates included demographics, year of dialysis initiation, cause of kidney failure, comorbid conditions, dialysis modality, and many others. RESULTS: Of 22,828 patients treated in the territories (American Samoa, Guam, Puerto Rico, Virgin Islands), 321 were white, 666 were black, 20,299 were Hispanic, and 1542 were Asian. Of 1,524,610 patients in the 50 states, 838,736 were white, 444,066 were black, 182,994 were Hispanic, and 58,814 were Asian. The crude mortality rate (deaths per 100 patient-years) was lower for whites in the territories than the 50 states (14 and 29, respectively), similar for blacks (18 and 17, respectively), higher for Hispanics (27 and 16, respectively), and higher for Asians (22 and 15). In matched analyses, greater risks of death remained for Hispanics (HR, 1.65; 95% confidence interval, 1.60 to 1.70; P<0.001) and Asians (HR, 2.01; 95% confidence interval, 1.78 to 2.27; P<0.001) living in the territories versus their matched 50 states counterparts. There were no significant differences in mortality among white or black patients in the territories versus the 50 states. CONCLUSIONS: Mortality rates for patients undergoing dialysis in the United States territories differ substantially by race/ethnicity compared with the 50 states. After matched analyses for comparable age and risk factors, mortality risk no longer differed for whites or blacks, but remained much greater for territory-dwelling Hispanics and Asians.

Department of Veterans Affairs Consensus: Preradiation dental treatment guidelines for patients with head and neck cancer.

Few protocols have been published for the dental management of patients with head and neck cancer to prevent complications from head and neck radiation therapy. Radiation therapy not only affects the tumor cells targeted, but also the dentition, bone, salivary gland, and oral soft tissue structures. A comprehensive dental evaluation prior to head and neck radiation therapy can help prevent many complications. The following clinical guidelines were established by a workgroup of oral health providers within the Department of Veterans Affairs. This workgroup focused on developing a set of recommendations regarding dental care prior to the initiation of head and neck radiation therapy based on the best clinical evidence and expert consensus. A systematic algorithm was developed for the evaluation including pre-exam data gathering, examination, education, and treatment, followed by maintenance and postradiation dental follow-up. This document is evidence-based, patient-centered, consistent with accepted practices of care and safety, and in accordance with applicable statutes and regulations.

Regional Variations in the Interpretation of the End-Stage Renal Disease Thirty-Month Coordination Period: Potential Implications for Patient Care.

Chronic kidney disease is a non-communicable disease that is now well recognized as a major source of premature morbidity and mortality. In general, racial/ethnic minorities in the United States are more likely than non-minority groups to develop end-stage renal disease (ESRD), but paradoxically most have a lower mortality risk. Unlike most minorities, dialysis patients in Puerto Rico have a mortality risk nearly 50% higher than the national average. Multiple factors such as medical conditions, socioeconomic, environmental, and health system factors can influence health outcomes for patients with ESRD. We describe one potential health system factor that may contribute to this finding, a unique interpretation and implementation of the ESRD Medicare Secondary Payer provision in the Commonwealth of Puerto Rico. We conducted a search of regulatory documents and key stakeholder interviews to help envision the potential implications of these differences for dialysis facilities, health care providers, and patients with ESRD.

Complete molar pregnancy in adolescents from North and South America: Clinical presentation and risk of gestational trophoblastic neoplasia.

OBJECTIVES: To compare complete hydatidiform mole (CHM) clinical presentation and risk factors associated with GTN development between North American and South American adolescents. METHODS: This non-concurrent cohort study was undertaken including adolescents with CHM referred to centers in North America (New England Trophoblastic Disease Center, Harvard University, USA), and South America (Botucatu Trophoblastic Disease Center-São Paulo State University, Brazil; Trophoblastic Unit of Central University of Venezuela and Maternidad Concepcion Palacios of Caracas, Venezuela) between 1990 and 2012. Data were obtained from medical records and pathology reports. Study participants were allocated into 2 groups: North America (NA) and South America (SA). RESULTS: In NA and SA, 13.1% and 30.9% of patients with hydatidiform mole were adolescents, respectively. Of these, 77.6% in NA and 86.1% in SA had pathologic diagnosis of CHM (p=0.121). Vaginal bleeding (SA=69% vs NA=51%; p=0.020), anemia (SA=48% vs NA=18%; p<0.001), and elevated serum hCG (SA=232,860mIU/mL vs NA=136,412mIU/mL; p=0.039) were more frequent in SA than in NA. Median gestational age at diagnosis (SA=12weeks, NA=11weeks; p=0.030) differed whereas GTN development rate (SA=20%, NA=27%; p=0.282) showed no significant difference between groups. Compared to NA, medical complications and clinical factors associated with post-molar GTN were more frequent among SA adolescents. CONCLUSIONS: Medical complications and clinical factors associated with GTN development were more frequent in SA than in NA adolescents with CHM, suggesting that, in South America, awareness about the importance of diagnosing molar pregnancy early and considering CHM in the differential diagnosis in adolescents suspected to be pregnant should be raised.

Total and speciated urinary arsenic levels in the Spanish population.

BACKGROUND: Very few studies exist on urinary arsenic exposure in Spain. OBJECTIVE: To evaluate total and speciated urinary arsenic (As) levels in a Spanish population sample. METHODS: Demographic, lifestyle and dietary data was collected for 124 volunteers (aged 20-76years; 88 women and 36 men), who were tested for total arsenic and five arsenic species using high-performance liquid chromatography-inductively coupled plasma mass spectrometry. RESULTS: Arsenobetaine (AB) and dimethylarsinic acid (DMA) were detected in 96.8% of the study participants (limit of detection (LOD) 1.0µg/L for AB and 1.9µg/L for DMA). Monomethylarsonic acid (MMA) and arsenous acid (As(III)) were detected in 5.6% (LOD 1.8µg/L) and 1.6% (LOD 1.4µg/L) of the participants, respectively; arsenic acid (As(V)) was not detected (LOD 1.4µg/L). AB and DMA (geometric mean (GM) 29.1µg/L and 7.5µg/L, respectively) were the main contributors to total urinary arsenic levels. Urinary DMA was positively associated with AB. CONCLUSION: Total arsenic levels observed in the Spanish population sample were higher than those reported by other European studies. The most recurrent urinary arsenic species was AB, followed by DMA, probably attributable to the high Spanish consumption of seafood. We recommend using inorganic As+MMA as the two main urinary biomarkers for inorganic As exposure. Our results provide reference data for analysing arsenic speciation results and assessing human exposure.

Daily Informal Multidisciplinary Intensive Care Unit Operational Debriefing Provides Effective Support for Intensive Care Unit Nurses.

BACKGROUND: Although most organizations have comprehensive formal stress management programs, an approach that is most likely to be helpful is the one that is curtailed specifically to the needs of a particular nursing unit. With that aim in mind, a process of daily intensive care unit (ICU) multidisciplinary operational debriefings was developed. These operational debriefings use the same concepts as traditional debriefing, yet are offered on a daily basis, rather than being reserved only for major stressful events. Furthermore, they are informal, brief (15 minutes), and multidisciplinary (intensivists, ICU nurses, chaplain, ICU social worker, ICU nutritionist, and ICU pharmacist). The purpose of this descriptive study was to determine the perceptions of attendees in relation to the implementation of daily operational debriefings. METHODS: Six months into the process, the attendees were requested to fill out an anonymous voluntary survey. Questions were simple, straightforward, and close ended. RESULTS: Of 47 potential respondents (42 nurses, 2 nurse managers, 1 social worker, 1 pharmacist, and 1 nutritionist), 42 completed the survey. Results revealed that an overwhelming majority felt that daily operational debriefings provide an effective unit-based support system, a sense of connectedness, and a commitment to the well-being of others. Nearly 50% of the respondents felt that the overall stress level in the ICU decreased, and 98% indicated operational daily debriefings should continue. CONCLUSION: Daily Informal multidisciplinary ICU operational debriefing provides an effective support system for ICU nurses. A modified model could be replicated for non-ICU units as well.

Enfermedad trofoblástica gestacional diagnosticada en restos ovulares obtenidos de pacientes con abortos espontáneos

Objetivo: Evaluar las características de la enfermedad trofoblástica gestacional, diagnosticada en restos ovulares obtenidos de pacientes con abortos espontáneos, atendidas en Sala de Partos de la Maternidad “Concepción Palacios” entre enero 2012 y enero 2014. Métodos: Estudio descriptivo, prospectivo, de corte transversal, que incluyó 325 pacientes con diagnóstico de aborto espontáneo. Previo consentimiento informado, se obtuvo información de la historia clínica, hallazgos del ultrasonido y de los resultados histopatológicos. Resultados: La frecuencia de mola parcial fue de 0,3 %. La edad promedio de las pacientes fue 27 años ± 7 años, la edad gestacional promedio fue 9 semanas + 3 días ± 4 semanas. La mediana de gestas obtenida fue 2, con un rango de 1 a 11. Un 89,84 % de las pacientes se encontraban sintomáticas al momento del ingreso, 55,4 % ingresó con cuello cerrado. Desde el punto de vista macroscópico 96,3 % eran de aspecto ovular, 3 % parcialmente hidrópicos, y 0,6 % hidrópicos y desde el punto de vista microscópico, 92,9 % correspondió a restos ovulares, 7 % a abortos con degeneración hidrópica y 0,3 % a mola parcial. No se encontró correlación estadística entre el ultrasonido y la histología para diagnóstico de enfermedad trofoblástica gestacional. Conclusión: La frecuencia de mola parcial fue baja.

Objective: To evaluate the characteristics of gestational trophoblastic disease, diagnosed in POC from patients with spontaneous abortions, attending Birthplace of “Concepcion Palacios Maternity” between January 2012 and January 2014. Method: A descriptive, prospective, cutting cross, which included 325 patients with a diagnosis of spontaneous abortion. Prior informed consent information from the clinical history, ultrasound findings and histopathological results were obtained. Results: The frequency of partial mole was 0.3 %, the average age of the patients was 27 years ± 7 years, mean gestational age was 9 weeks + 3 days ± 4 weeks. Median deeds obtained was 2 with a range of 1 to 11 A 89.84 % of patients were symptomatic at the time of admission, 55.4 % were admitted with high collar. From the macroscopic viewpoint aspect 96.3 % were ovulating, 3 % partially hydropic and hydropic and 0.6 % from the microscopic, 92.9.% are POC, 7% to abortions with hydropic degeneration and 0, 3 % a partial mole. We did not find that there is statistical correlation between ultrasound and histology for the diagnosis of gestational trophoblastic disease. Conclusion: the frequency of partial mole was low.

[Multiple aneurysms splenic; surgical exclusion with conservation of the spleen]. / Aneurismas esplénicos múltiples; exclusión quirúrgica con conservación del bazo.

BACKGROUND: Aneurysm of the splenic artery is diagnosed when the diameter of the splenic artery is greater than 1cm. It occupies third place among abdominal aneurysms. It is more frequent in women (4:1). It is associated with trauma, haemodynamics and local hormonal effects during pregnancy, portal hypertension (including the Caroli syndrome), arterial degeneration, atherosclerosis, and liver transplantation. It is difficult to diagnose, and it generally presents as ruptured, thus once the diagnosis is made, the surgical approach is indicated due to its high mortality. CLINICAL CASE: Female of 66 years of age with a diagnosis of splenic artery aneurysm, with pulsing sensation at epigastric level of 8 months onset. On physical examination there is a palpable throbbing mass of 9 cm of diameter approximately, for which she was admitted. The computed tomography angiography with reconstruction showed three splenic aneurysms. Two were tied and the larger one was repaired by endo-aneurysmorrhaphy. DISCUSSION: Visceral aneurysms are extremely rare. They are currently increasing and are the third leading cause of cardiovascular death, as morbidity/mortality is high. The surgical treatment must be done selectively according to their size. Selection of the surgical techniques depends on the anatomic location and the need for revascularisation, the aetiology and the experience of the surgeon. CONCLUSION: A review has been presented on the advances in diagnostic, and management, concluding that the best is to preserve the spleen, and whatever the technique it must be performed by trained surgeons.

Mola hidatiforme recurrente asociada a mutación del gen NLRP7: A propósito de un caso / Mola recurrent hydatidiform associated with gene mutation NLRP7. About a case

Presentamos el caso de una paciente de 35 años de edad, VII gestas, VI molas I aborto, portadora de la mutación en la proteína NLRP7, evaluada en el servicio de patología del primer trimestre del embarazo de la Maternidad “Concepción Palacios” entre los años 1998- 2010. Ambos padres tenían cariotipos normales y se detectó un antecedente familiar de embarazo molar. Este caso forma parte de un raro subconjunto de molas cuyo origen es biparental, generalmente recurrente y a menudo familiar y se asocia a imposibilidad de obtener un embarazo exitoso.

We report the case of a 35 years old patient, with 7 pregnancies, 6 molas, 1 abortion, carrier of a mutation in the protein NLRP7, evaluated in the pathology service of the Maternidad “Concepcion Palacios” between 1998-2010. Both parents had normal karyotypes and a family history of molar pregnancy was detected. This case is part of a rare subset of molas with biparental origin, usually recurrent and often family and associated with failure to obtain a successful pregnancy.

Plasma levels of trace elements and exercise induced stress hormones in well-trained athletes.

This study analyzed the variation and relationship of several trace elements, metabolic substrates and stress hormones activated by exercise during incremental exercise. Seventeen well-trained endurance athletes performed a cycle ergometer test: after a warm-up of 10 min at 2.0 W kg(-1), the workload was increased by 0.5 W kg(-1) every 10 min until exhaustion. Prior diet, activity patterns, and levels of exercise training were controlled, and tests timed to minimize variations due to the circadian rhythm. Oxygen uptake, blood lactate concentration, plasma ions (Zn, Se, Mn and Co), serum glucose, non-esterified fatty acids (NEFAs) and several hormones were measured at rest, at the end of each stage and 3, 5 and 7 min post-exercise. Urine specific gravity was measured before and after the test, and participants drank water ad libitum. Significant differences were found in plasma Zn and Se levels as a function of exercise intensity. Zn was significantly correlated with epinephrine, norepinephrine and cortisol (r = 0.884, P < 0.01; r = 0.871, P < 0.01; and r = 0.808, P = 0.05); and Se showed significant positive correlations whit epinephrine and cortisol (r = 0.743, P < 0.05; and r = 0.776, P < 0.05). Neither Zn nor Se levels were associated with insulin or glucagon, and neither Mn nor Co levels were associated with any of the hormones or substrate metabolites studied. Further, while Zn levels were found to be associated only with lactate, plasma Se was significantly correlated with lactate and glucose (respectively for Zn: r = 0.891, P < 0.01; and for Se: r = 0.743, P < 0.05; r = 0.831, P < 0.05). In conclusion, our data suggest that there is a positive correlation between the increases in plasma Zn or Se and stress hormones variations induced by exercise along different submaximal intensities in well-hydrated well-trained endurance athletes.

Modelo biológico no vivo para la enseñanza de la técnica de venodisección en alumnos de pregrado de la carrera de medicina / Non-live biological model for the teaching of the venous cutdown technique to undergraduate medical students

Objetivo: Proporcionar material didáctico útil al estudiante y al médico general para conocer la técnica de venodisección en un modelo biológico no vivo. Sede: Departamento de Cirugía, Facultad de Medicina, UNAM. Diseño: Modelo de enseñanza. Material y método: Se proporcionan indicaciones, contraindicaciones, características anatómicas y técnica a considerar. Empleamos pata de cerdo como modelo didáctico por ser accesible en costos, disponibilidad y un modelo fácilmente reproducible por los alumnos. Por su semejanza con los eventos clínicos que suceden en los pacientes a nivel hospitalario, consideramos que representa un buen método de enseñanza de habilidades quirúrgicas en el pregrado. Conclusión: El actual modelo biológico es una opción viable y representativa de la venodisección; el alumno aprende a identificar al paciente que requiere de este procedimiento; una vez identificado, podrá realizar el procedimiento de manera adecuada evitando, en la medida de lo posible, cualquier tipo de complicación.

Objective: To provide teaching material useful for the medical student and the general physician to learn the venous cutdown technique in a non-live biological model. Setting: Department of Surgery, School of Medicine, UNAM. Design: Teaching model. Material and method: Indications, contraindication, anatomical characteristics and technique to be considered will be provided. We use a pig foot as didactic model because it is accessible in terms of costs, availability, and can be reproduced easily by students. Due to its similarity with clinical events occurring in patients at the hospital level, we consider that it represents a good teaching method of surgical skills at the undergraduate level. Conclusion: The current biological model is a viable option and representative of venous cutdown. The student learns to identify the patient that requires this procedure, once identified he will be able to perform the procedure adequately avoiding, as much as possible, any type of complication.

Identification of the prevalent BRCA1 and BRCA2 mutations in the female population of Puerto Rico.

Mutations in the breast cancer 1, early onset (BRCA1) and breast cancer 2 (BRCA2) genes are responsible for the majority of hereditary breast cancers. Knowledge of the incidence and prevalence of BRCA mutations in a specific population or ethnic group is necessary to provide accurate genetic counseling for breast cancer patients and their families; however, these data have not been gathered in the population of Puerto Rico. We conducted a retrospective study of female breast cancer patients undergoing genetic testing for BRCA mutations in the highest-volume breast surgery practices in San Juan, Puerto Rico. Data collection includes three-generation family cancer history and results from complete BRCA sequencing. A total of six different deleterious mutations were observed, including one mutation in BRCA1 and five mutations in BRCA2. Three recurrent mutations (BRCA1 del exon1-2, BRCA2 4150G>T, and BRCA2 6027del4) account for over 70% of all the BRCA mutations observed in this study population. This study examines for the first time the characteristics of hereditary breast cancer in Puerto Rico and assesses the accuracy of existing genetic risk assessment tools in that population. This data is expected to contribute to providing accurate and efficient tools for the clinical management of hereditary breast cancer in Puerto Rico.

Modeling follicle stimulating hormone levels in serum for controlled ovarian hyperstimulation III: improved gonadotropin administration.

BACKGROUND: A numerical model with two pharmacokinetic parameters (the rate of diffusion into the blood (τin) and the rate of disappearance from the blood (τout)) mimicks the slow changes of follicle stimulating hormone (FSH) seen in serum. It is often desired to change serum FSH levels more rapidly. Since the pharmacokinetic parameters cannot be changed in patients, we used the model to investigate changing the amount and timing of gonadotropin administration to change FSH levels in serum more rapidly. METHODS: Parameters defining the model were obtained as described previously [1]. The doses administered, and the timing of administration were individually specified. RESULTS: The rise of serum FSH was made more rapid by administering an initial injection larger than the subsequent injections. When a rapid decrease of serum FSH was desired, administration of the new, lower dose was delayed. CONCLUSION: Use of a model that simulates the serum levels of FSH during gonadotropin administration provided a framework for learning how to achieve the desired serum FSH levels more rapidly in patients. With knowledge of a particular patient's τin and τout, optimal FSH administration for that patient can be determined through modeling.