An anatomic description of intrinsic brachial muscles in the crab-eating fox (Cerdocyon thous, Linnaeus 1776) and report of a variant arterial distribution.

The crab-eating fox (Cerdocyon thous) is a wild canid distributed throughout South America. It is one of the wild canids reported being hit by vehicles and injured in snares, thus inducing trauma or injury to the musculoskeletal system, possibly occurring in the brachial region. The main objective of this research was to provide an anatomic description of the crab-eating fox's intrinsic brachial muscles including shape, origin, insertion, innervation and arterial blood supply, compared with that of the domestic dog. We dissected from superficial to deep two thoracic limbs of seven dead specimens donated to the University of Caldas by CORPOCALDAS. These muscles presented anatomic characteristics similar to those reported in the domestic dog (Canis lupus familiaris) but with a variant in arterial blood supply, allowing us to suggest that surgical procedures that need the knowledge of intrinsic brachial muscles in the crab-eating fox may be homologous to the domestic dog. However, one should consider its variant arterial distribution by part of the collateral radial artery and deep brachial artery to prevent incorrect incisions that may damage these arteries.

Neonatal cardiomyopathy in mice homozygous for the Arg403Gln mutation in the alpha cardiac myosin heavy chain gene.

Heterozygous mice bearing an Arg403Gln missense mutation in the alpha cardiac myosin heavy chain gene (alpha-MHC403/+) exhibit the histopathologic features of human familial hypertrophic cardiomyopathy. Surprisingly, homozygous alpha-MHC403/403 mice die by postnatal day 8. Here we report that neonatal lethality is caused by a fulminant dilated cardiomyopathy characterized by myocyte dysfunction and loss. Heart tissues from neonatal wild-type and alpha-MHC403/403 mice demonstrate equivalent switching of MHC isoforms; alpha isoforms in each increase from 30% at birth to 70% by day 6. Cardiac dimensions and function, studied for the first time in neonatal mice by high frequency (45 MHz) echocardiography, were normal at birth. Between days 4 and 6, alpha-MHC403/403 mice developed a rapidly progressive cardiomyopathy with left ventricular dilation, wall thinning, and reduced systolic contraction. Histopathology revealed myocardial necrosis with dystrophic calcification. Electron microscopy showed normal architecture intermixed with focal myofibrillar disarray. We conclude that 45-MHz echocardiography is an excellent tool for assessing cardiac physiology in neonatal mice and that the concentration of Gln403 alpha cardiac MHC in myocytes influences both cell function and cell viability. We speculate that variable incorporation of mutant and normal MHC into sarcomeres of heterozygotes may account for focal myocyte death in familial hypertrophic cardiomyopathy.

Dilated cardiomyopathy in homozygous myosin-binding protein-C mutant mice.

To elucidate the role of cardiac myosin-binding protein-C (MyBP-C) in myocardial structure and function, we have produced mice expressing altered forms of this sarcomere protein. The engineered mutations encode truncated forms of MyBP-C in which the cardiac myosin heavy chain-binding and titin-binding domain has been replaced with novel amino acid residues. Analogous heterozygous defects in humans cause hypertrophic cardiomyopathy. Mice that are homozygous for the mutated MyBP-C alleles express less than 10% of truncated protein in M-bands of otherwise normal sarcomeres. Homozygous mice bearing mutated MyBP-C alleles are viable but exhibit neonatal onset of a progressive dilated cardiomyopathy with prominent histopathology of myocyte hypertrophy, myofibrillar disarray, fibrosis, and dystrophic calcification. Echocardiography of homozygous mutant mice showed left ventricular dilation and reduced contractile function at birth; myocardial hypertrophy increased as the animals matured. Left-ventricular pressure-volume analyses in adult homozygous mutant mice demonstrated depressed systolic contractility with diastolic dysfunction. These data revise our understanding of the role that MyBP-C plays in myofibrillogenesis during cardiac development and indicate the importance of this protein for long-term sarcomere function and normal cardiac morphology. We also propose that mice bearing homozygous familial hypertrophic cardiomyopathy-causing mutations may provide useful tools for predicting the severity of disease that these mutations will cause in humans.

40 MHz Doppler characterization of umbilical and dorsal aortic blood flow in the early mouse embryo.

Physiological study of the developing mouse circulation has lagged behind advances in molecular cardiology. Using an innovative high-frequency Doppler system, we noninvasively characterized circulatory hemodynamics in early mouse embryos. We used image-guided 43 MHz pulsed-wave (PW) Doppler ultrasound to study the umbilical artery and vein, or dorsal aorta in 109 embryos. Studies were conducted on embryonic days (E) 9.5-14.5. Heart rate, peak blood flow velocities, and velocity time integrals in all vessels increased from E9.5-14.5, indicating increasing stroke volume and cardiac output. Heart rate, ranging from 192 bpm (E9.5) to 261 bpm (E14.5), was higher than previously reported. Placental impedance, assessed by the time delay between the peaks of the umbilical arterial and venous waveforms and by venous pulsatility, decreased with gestation. Acceleration time, a load-independent Doppler index of cardiac contractility, remained constant but seemed sensitive to heart rate. High-frequency PW Doppler is a powerful tool for the quantitative, noninvasive investigation of early mouse circulatory development.

40-MHZ echocardiography scanner for cardiovascular assessment of mouse embryos.

Congenital heart disease results from genetic defects that are manifested at early stages of embryogenesis. The mouse is the preferred animal model for studies of mammalian embryonic development and for an increasing number of human disease models. A number of genes identified in the mouse are critical for normal cardiovascular development, but an understanding of the underlying mechanisms regulating heart development is still incomplete, in part because of the lack of methods to measure hemodynamics in live mouse embryos. We describe the development of a 40-MHz ultrasound scanner, which allows image-guided continuous-wave and pulsed Doppler blood flow measurements in mouse embryos, in utero, at the critical early developmental stages. Doppler waveforms acquired from mouse embryonic umbilical vessels, descending aorta, and cardiac ventricles are presented to demonstrate the utility of the method. By combining image-guided ultrasound Doppler with the many available mouse mutants, this approach should lead to new insights into embryonic cardiovascular structure-function relationships.

Biocerâmica de fosfato de cálcio nanoestruturada micro-macroporosa em grânulos de absorção rápida no preenchimento de defeito crítico em rádio de coelhos (Oryctolagus cuniculus) / Bioceramics of calcium phosphate nano-structured micro-macro porous granules rapidly absorbed in filling critical radial defect in rabbits (Oryctolagus cuniculus)

O objetivo do presente trabalho foi avaliar, por radiografia, histologia e densitometria óssea, o efeito da HA/ßTCP em grânulos de absorção rápida em defeito ósseo crítico em rádio de coelhos. Foram utilizados 35 coelhos machos, da raça Nova Zelândia, e realizou-se um defeito crítico nos rádios direito e esquerdo. Os animais foram distribuídos em GI, enxerto autólogo e GII, HA/ßTCP em grânulos de absorção rápida. Avaliações radiográficas foram feitas antes da cirurgia, após, aos oito, 15, 30, 45 e 60 dias e avaliações histológicas e de densitometria. Verificou-se diferença significativa ao se comparar a densidade mineral óssea obtida ao longo do tempo de estudo. Observou-se formação de rede vascular entre os poros da biocerâmica desde o primeiro tempo de avaliação, (oito dias). Foram observados tecido ósseo primário e trabéculas em tecido ósseo preexistente a partir de 30 dias da implantação. Aos 60 dias, constatou-se presença de matriz óssea em segmentos ósseos preexistentes, caracterizando a formação óssea centrípeta. A biocerâmica HA/ßTCP nanoestruturada micro-macroporosa em grânulos de absorção rápida não causa alterações microscópicas indicativas de rejeição, permite a invasão e a multiplicação celular, bem como propicia a regeneração óssea, constituindo um implante apropriado para preenchimento de falhas ósseas críticas.(AU)

The objective of this study was to evaluate the effect of HA/ ßTCP on rapid absorption granules in rabbit radiography, histology, and bone densitometry. Thirty - five male rabbits of the New Zealand breed were used and a critical defect was performed on the right and left radios. The animals were distributed in GI, autologous graft and GII HA / ßTCP in rapidly absorbed granules. Radiographic, histological, and densitometry evaluations were performed before surgery, then after eight, 15, 30, 45 and 60 days. A significant difference was found when comparing the bone mineral density obtained over the study time. Formation of vascular network between the bioceramic pores was observed by the first evaluation time, (eight days). Primary bone tissue and trabeculae were observed from preexisting bone tissue after 30 days of implantation. At 60 days, the presence of bone matrix was observed from the preexisting bone segments, characterizing the centripetal bone formation. The micro-macroporous nanocomposite HA / ßTCP of rapidly absorbing granules do not cause microscopic changes indicative of rejection, allows invasion, cell multiplication, and promotes bone regeneration, constituting an appropriate implant for filling of critical bone failures.(AU)

Avaliação histológica e por microscopia eletrônica de varredura da biocerâmica de fosfato de cálcio nano-estruturada micromacro porosa em grânulos em defeito crítico de rádio de coelhos / Histological and nano-structured calcium phosphate bioceramic micro-macro porous granules in critical defect rabbits radius scanning electron microscopy evaluation

Objetivou-se avaliar, histologicamente e por microscopia eletrônica de varredura (MEV), a evolução de defeitos críticos experimentais em rádio de coelhos preenchidos ou não com biocerâmica fosfocálcica nanoestruturada micromacro porosa em grânulos. Utilizaram-se 70 coelhos, Nova Zelândia, adultos jovens, machos, e realizou-se um defeito crítico nos rádios. Os membros constituíram os grupos: GI, biocerâmica lenta, GII, biocerâmica moderada e GIII, controle negativo. Após cada período experimental, os animais foram sacrificados, e os rádios coletados. As avaliações histológicas foram realizadas aos oito, 15, 30, 45, 60, 90 e 120 dias, e as análises de MEV aos 60, 90 e 120 dias. Histologicamente, observou-se processo de reparação óssea mais adiantado nos grupos GI e GII comparando-se ao GIII. Na MEV, constatou-se maior proporção de osso maduro e presença de ósteons secundários nos GI e GII, sendo mais evidente no GII, confirmando os achados histológicos. As cerâmicas promoveram preenchimento completo do defeito, enquanto no grupo controle houve preenchimento no centro do defeito, permanecendo espaços vazios nas laterais. Conclui-se que o emprego das biocerâmicas de absorção lenta e moderada favorece a regeneração óssea completa em defeitos críticos sendo indicadas como substituto ósseo. A maturação óssea ocorre mais precocemente quando se emprega a cerâmica de absorção moderada.(AU)

The objective was to evaluate, through histologic exam and by scanning electron microscopy (SEM), the evolution of experimental critical defects in radio or not filled with nano-structured calcium phosphate micro-macro porous bioceramic granules rabbits. We used 70 rabbits, New Zealand, young adults, males, there was a critical defect in radio. The members were the groups: GI, slow bioceramic, GII, GIII and bioceramic moderate, negative control. After each experimental period, the animals were sacrificed and the radios harvested. Histological evaluations were performed at eight, 15, 30, 45, 60, 90 and 120 days and SEM analyzes at 60, 90 and 120 days. Histologically there was bone healing process earlier in GI and GII compared to GIII. In SEM we observed a higher proportion of mature bone and presence of secondary osteons in GI and GII, being more evident in the GII, confirming the histological findings. Ceramic promoted complete filling of the defect, while the control group was filling in the center of the defect, with empty spaces remaining on the sides. In conclusion, the use of bioceramics, slow and moderate absorption favor complete bone regeneration in critical defects being indicated as a bone substitute. The maturation occurs earlier when employing the ceramic moderate absorption.(AU)

Evaluación del impacto clínico y la seguridad de una unidad de dolor torácico en pacientes con probabilidad baja e intermedia de síndrome coronario agudo / Assessment of clinical impact and security of a chest pain unit in patients with low and intermediate probability of an acute coronary syndrome

Antecedentes; Aunque las unidades de dolor torácico (UDT) permiten la estratificación y atención apropiada de los pacientes con dolor de pecho, en Colombia el desarrollo e implementación sistemática y estandarizada de este proceso de atención es escaso. Objetivo: Evaluar el impacto clínico y la seguridad del proceso de atención de una UDT en pacientes con probabilidad baja e intermedia de síndrome coronario agudo en Medellín, Colombia. Métodos: Estudio descriptivo que incluyó 277 pacientes, que fueron ingresados en una UDT de quienes se obtuvo información demográfica, clínica y de la gestión del proceso de atención. En el seguimiento a 30 días se evaluó la sobrevida y eventos compatibles con la enfermedad coronaria. Resultados De toda la muestra, el 13,0% de los pacientes fue remitido a un tercer nivel de atención y solo el 2,5% tuvieron un diagnóstico final confirmado de síndrome coronario agudo. La mediana del tiempo entre la recepción en urgencias y la toma del electrocardiograma fue 10,0 minutos, en el servicio de urgencias se calculó el puntaje TIMI y se hizo la estratificación del riesgo en el 85,5 y 73,9%, respectivamente. La comparación entre la fase de implementación y consolidación mostró una mejoría en los indicadores (p < 0,05). Durante el seguimiento a 30 días no se observaron muertes ni eventos coronarios. Conclusión: La UDT basada en la evaluación clínica, la aplicación de la escala TIMI y la interpretación del electrocardiograma, constituyen una forma eficaz de estratificación de los pacientes con probabilidad baja o intermedia de síndrome coronario agudo, su implementación es segura y el riesgo de complicaciones es muy bajo.

Background: Chest pain units (CPU) are an accepted method to assess patients admitted to an emergency department with chest pain with a potential ischemic origin. Yet in Colombia, the customary admission to a CPU in a standardized fashion is scarce and, to our knowledge, the outcome of implementing recognized protocols for chest pain has not been evaluated. Objective: To assess the clinical impact and security of CPU, in patients with, low and intermediate probability of acute coronary syndrome, in Medellín, Colombia. Methods: A descriptive study comprising 277 subjects who were consecutively admitted to the CPU. Variables included demographics, and performance measures to assess the process of care (timely action and process completion). A 30 days follow-up included survival and new admissions compatible with coronary syndromes. Results: From the whole sample, 13.0% of patients were referred for hospitalization. However, only 2.5% had a final diagnosis of an acute coronary syndrome. Median time between reception and an electrocardiogram acquisition was 10 minutes TIMI score and acute coronary syndrome probability were reported in 85.5 and 73.9% of subjects respectively. Comparison between early implementation and consolidation phases showed a sensible improvement of performance measure indicators (p < 0.05). In addition, 30-day follow-up showed neither fatalities nor new coronary events. Conclusion: Chest pain observation unit based on clinical assessment of thoracic pain, TIMI risk score and ST segment changes interpretation in the ECG is a safe and efficacious way to stratify low and intermediate chest pain leading to a safe patient discharge with very low risk of cardiovascular complications.

Noninvasive, in utero imaging of mouse embryonic heart development with 40-MHz echocardiography.

BACKGROUND: The increasing number of transgenic and targeted mutant mice with embryonic cardiac defects has resulted in the need for noninvasive techniques to examine cardiac structure and function in early mouse embryos. We report the first use of a novel 40-MHz ultrasound imaging system in the study of mouse cardiac development in utero. METHODS AND RESULTS: Transabdominal scans of mouse embryos staged between 8.5 and 13.5 days of gestation (E8.5 to E13.5) were obtained in anesthetized mice. Atrial and ventricular contractions could be discerned from E9.5, and changes in cardiac morphology were observed from E9.5 to E13.5. Hyperechoic streaming patterns delineated flow through the umbilical, vitelline, and other major blood vessels. Diastolic and systolic ventricular areas were determined by planimetry of the epicardial borders, and fractional area change was measured as an index of contractile function. Significant increases in ventricular size were documented at each stage between E10.5 and E13.5, and the ability to perform serial imaging studies over 3 days of embryonic development is described. Finally, the detection of vascular cell adhesion molecule 1 (VCAM-1) homozygous null mutant embryos demonstrates the first example of noninvasive, in utero analysis of cardiac structure and function in a targeted mouse mutant. CONCLUSIONS: We used 40-MHz echocardiography to identify key elements of the early mouse embryonic cardiovascular system and for noninvasive dimensional analysis of developing cardiac ventricles. The ability to perform serial measurements and to detect mutant embryos with cardiac defects highlights the usefulness of the technique for investigating normal and abnormal cardiovascular development.

Principios de la evaluación hemodinámica no invasiva con cardiografía de impedancia / Principles of non-invasive hemodynamic assessment with impedance cardiography

La cardiografía de impedancia es una técnica no invasiva que permite una determinación rápida, continua y reproducible del gasto cardiaco latido a latido. Mide los cambios en la resistencia eléctrica del tórax que se producen por las variaciones en el volumen sanguíneo en la aorta durante el ciclo cardiaco. La medición continua del cambio en la impedancia o las fluctuaciones del volumen sanguíneo durante la sístole y la diástole, permite determinar el volumen latido, el gasto cardiaco, la contractilidad miocárdica y el contenido total de fluido del tórax. Entre las ventajas de esta técnica se incluyen su fácil implementación y asequibilidad, así como la posibilidad de ser realizada por prácticamente cualquier miembro del equipo de salud. La precisión de la cardiografía de impedancia ha sido validada en numerosos estudios en diferentes escenarios clínicos: hipertensión arterial, falla cardiaca, hipertensión pulmonar, optimización de la terapia de resincronización cardiaca y en pacientes críticos, situaciones en las que provee información sobre el estado hemodinámico sin los riesgos de otras técnicas invasivas o mínimamente invasivas. Es además un método de fácil aplicación y costo-efectivo para el diagnóstico y seguimiento de la respuesta a las intervenciones terapéuticas en múltiples patologías. La técnica representa así un cambio en los paradigmas del monitoreo hemodinámico.

Impedance cardiography (ICG) is a non-invasive technique that allows a rapid, continuous and reproducible beat-to-beat cardiac output estimation. This technique measures thoracic electrical resistance changes produced by variations in the blood volume in the aorta during the cardiac cycle. Continuous measurement of impedance changes or fluctuations of blood volume during systole and diastole allow the determination of stroke volume, cardiac output, myocardial contractility, and total thoracic fluid content. Between the advantages of this technique are included its easy implementation and accessibility, as well as the possibility of its measurement by practically any member of the health team. Impedance cardiography accuracy has been validated in several clinical scenarios such as arterial hypertension, heart failure, pulmonary hypertension, optimization of cardiac resynchronization therapy, and in critically ill patients, situations where it provides information about the hemodynamic state without the risks and costs of other invasive or minimally invasive techniques. It is also an easy to use, cost-effective method for the diagnosis and follow-up of the response to therapeutic interventions in multiple clinical scenarios. Thus, this technology represents a change in the paradigms of hemodynamic monitoring.

Beneficios de la actividad física en la enfermedad cardiovascular / Benefits of the physical activity in the cardiovascular disease

Se ha considerado que el sedentarismo es un factor de riesgo, independiente para enfermedad cardiovascular, por tal motivo en la actualidad se le da tanta importancia a la actividad física para que ésta se constituya en factor protector contra la enfermedad coronaria...

Eficacia del dinitrato de isosorbide en el control de la hipertensión sistólica aislada del anciano / Isosorbide dinitrate efficiency in control of the old ISH

Se realizó un estudio aleatorio, doble ciego y controlado con placebo en 29 pacientes con Hipertensión Sistólica Aislada (HSA) con edad promedio de 77 ± 9.5 años, residentes en una comunidad de ancianos, con el objetivo de evaluar el efecto antihipertensivo del Dinitrato de Isosorbide de liberación sostenida (DNIS), 20 a 40 miligramos, administrados dos veces al día versus placebo. Los pacientes fueron evaluados para descartar causas secundarlas de hipertensión como se ha recomendado, además recibieron tratamiento no farmacológico concomitante. Después de 8 semanas de tratamiento la Presión Arterial Sistólica disminuyó de 177 ± 10 a 146± 16 mm Hg con DNIS (P. < 001) y de.173 ± 15 a 164 ± 8 mmHg con placebo (P. > 05). La reducción se observó desde la primera semana de tratamiento y no hubo diferencias significativas en la presión arterial diastólica ni en los efectos secundarlos durante el mismo periodo. Este estudio proporciona evidencia de que el DNIS es efectivo y seguro para reducir en forma selectiva y sostenida la Presión arterial sistólica en ancianos con HSA.