Upwelling as a stressor event during embryonic development: Consequences for encapsulated and early juvenile stages of the marine gastropod Acanthina monodon.

Upwelling phenomena alter the physical and chemical parameters of the sea's subsurface waters, producing low levels of temperature, pH and dissolved oxygen, which can seriously impact the early developmental stages of marine organisms. To understand how upwelling can affect the encapsulated development of the gastropod Acanthina monodon, capsules containing embryos at different stages of development (initial, intermediate and advanced) were exposed to upwelling conditions (pH = 7.6; O2 = 3 mg L-1; T° = 9 °C) for a period of 7 days. Effects of treatment were determined by estimating parameters such as time to hatching, number of hatchlings per capsule, percentage of individuals with incomplete development, and shell parameters such as shell shape and size, shell strength, and the percentage of the organic/inorganic content. We found no significant impacts on hatching time, number of hatchlings per capsule, or percentage of incomplete development in either the presence or absence of upwelling, regardless of developmental stage. On the other hand, latent effects on encapsulated stages of A. monodon were detected in embryos that had been exposed to upwelling stress in the initial embryonic stage. The juveniles from this treatment hatched at smaller sizes and with higher organic content in their shells, resulting in a higher resistance to cracking 30 days after hatching, due to greater elasticity. Geometric morphometric analysis showed that exposure to upwelling condition induced a change in the morphology of shell growth in all post-hatching juveniles (0-30 days), regardless of embryonic developmental stage at the time of exposure. Thus, more elongated shells (siphonal canal and posterior region) and more globular shells were observed in newly hatched juveniles that had been exposed to the upwelling condition. The neutral or even positive upwelling exposure results suggests that exposure to upwelling events during the encapsulated embryonic phase of A. monodon development might not have major impacts on the future juvenile stages. However, this should be taken with caution in consideration of the increased frequency and intensity of upwelling events predicted for the coming decades.

UV-R mitigation strategies in encapsulated embryos of the intertidal gastropod Acanthina monodon: A way to compensate for lack of parental care.

Intracapsular embryonic development in the intertidal zone exposes embryos to various stress sources characteristic of this environment, including UV-R. They require defensive mechanisms to mitigate its adverse effects. The presence of total carotenoids (TC), and mycosporine-like amino acids (MAAs) was studied in adults, in encapsulated embryos, and in the egg capsule walls of the intertidal gastropod Acanthina monodon. Oxygen consumption rates (OCR) were determined in encapsulated and excapsulated embryos exposed to photosynthetically active radiation (PAR) and PAR + UV-A + UV-B to understand if the capsule wall is a protective structure for encapsulated embryos. The results showed the presence of TC in adult pedal and gonad tissues, and in all encapsulated stages. MAAs were not detected. The physical structure of the capsule wall retained most wavelengths, being particularly efficient in the UV-B range. Excapsulated embryos exposed to PAR + UV-A + UV-B radiation increased its OCR compared to encapsulated embryos, indicating the protective character of the capsule wall.

Contrapulsación intraaórtica en cirugía coronaria: factores predictivos de mortalidad hospitalaria / Intraaortic countenpulsation in coronary surgery: prediction factors of hospital mortality

La contrapulsación aórtica (CPIA) es el método más básico y difundido de asistencia circulatoria. Su utilidad en el síndrome de bajo gasto postcardiotomía aún comporta alta mortalidad. Pretendemos identiificar factores relacionados con el perfil preoperatoriodel paciente y el procedimiento realizado, que tenga carácter predictivo de mortalidad hospitalaria (MH) en la utilización de CPIA por bajo gasto tras cirugía coronaria. Entre septiembre de 1995 y abril de 1998 hemos intervenido 382 pacientes coronarios. Se utilizó CPIA en 54 casos (14 por ciento). Analizamos 50 variables pre e intraoperatorias de potencial carácter predictivo en el grupo A (29 supervivientes) y B (25 fallecidos). La MH por CPIA en coronarios fue del 46 por ciento. Todos los scores de riesgo preoperatorio fueron más elevados en el grupo B, aunque el score de Parsonnet mostró diferencias significativas (grupo A: 6 vs B: 12,9) (p<0,01). La mayor utilización de venas (grupo A:1,3 vs B:2) (p<0,05), el menor uso de injertos arteriales (A:79 por ciento vs B:56 por ciento) y el carácter emergente de la cirugía (A:7 por ciento vs B:20 por ciento) también se relacionaron con la MH. La CPIA en el sindrome postcardiotomía tras revascularización coronaria aún presenta altas cifras de MH. En nuestra experiencia la MH se asocia a un perfil de riesgo elevado del paciente, así como con el tipo de injerto empleado y con el carácter emergente de la cirugía

Contrapulsación intraaórtica en cirugía coronaria: factores predictivos de mortalidad hospitalaria / Intraaortic countenpulsation in coronary surgery: prediction factors of hospital mortality

La contrapulsación aórtica (CPIA) es el método más básico y difundido de asistencia circulatoria. Su utilidad en el síndrome de bajo gasto postcardiotomía aún comporta alta mortalidad. Pretendemos identiificar factores relacionados con el perfil preoperatoriodel paciente y el procedimiento realizado, que tenga carácter predictivo de mortalidad hospitalaria (MH) en la utilización de CPIA por bajo gasto tras cirugía coronaria. Entre septiembre de 1995 y abril de 1998 hemos intervenido 382 pacientes coronarios. Se utilizó CPIA en 54 casos (14 por ciento). Analizamos 50 variables pre e intraoperatorias de potencial carácter predictivo en el grupo A (29 supervivientes) y B (25 fallecidos). La MH por CPIA en coronarios fue del 46 por ciento. Todos los scores de riesgo preoperatorio fueron más elevados en el grupo B, aunque el score de Parsonnet mostró diferencias significativas (grupo A: 6 vs B: 12,9) (p<0,01). La mayor utilización de venas (grupo A:1,3 vs B:2) (p<0,05), el menor uso de injertos arteriales (A:79 por ciento vs B:56 por ciento) y el carácter emergente de la cirugía (A:7 por ciento vs B:20 por ciento) también se relacionaron con la MH. La CPIA en el sindrome postcardiotomía tras revascularización coronaria aún presenta altas cifras de MH. En nuestra experiencia la MH se asocia a un perfil de riesgo elevado del paciente, así como con el tipo de injerto empleado y con el carácter emergente de la cirugía (AU)

[Dynamic cardiomyoplasty. Preliminary experience]. / Cardiomioplastia dinámica. Experiencia preliminar.

INTRODUCTION AND OBJECTIVES: The purpose of this study is to show our experience in clinical dynamic cardiomyoplasty. PATIENTS, MATERIALS AND METHODS: Six patients with end-stage heart failure and 2 patients with left ventricular aneurysm underwent dynamic cardiomyoplasty using the latissimus dorsi muscle. The latissimus dorsi was electrically conditioned before the procedure through a lead placed under local anesthesia and connected to an external cardiac pace-maker. Surgical technique--including dissection of the latissimus dorsi and encircling of the ventricles with the muscle flap--was performed in general terms as described at the Broussais Hospital. In the first 3 patients a bipolar lead connected to a single impulse generator was used. In the other 5 patients a train of impulses cardiomyostimulator was used. Changes in systolic function were studied through Doppler-echocardiography and radionuclide studies. Changes in diastolic function were evaluated through E wave velocity and deceleration time. RESULTS: Mean follow up was 9 +/- 5.7 months. No early deaths were recorded. One patient underwent emergency surgery, one week after the procedure, because of a tear of the patch used to close the wall defect after left ventricular aneurysm resection. In 2 patients a subcutaneous serous collection secondary to muscle dissection was evacuated. One patient died due to a stroke 4 months after the procedure. Another patient died after an unsuccessful coronary transluminal percutaneous angioplasty 11 months after the procedure. An improved functional class was observed in all patients. No changes in systolic function were observed after surgery when the cardiomyoestimulator was turned-off either with echocardiography (26.7 +/- 8.6 vs 24.8 +/- 5.8% [NS]) or radionuclides (24.5 +/- 9.5 vs 20.2 +/- 8.3% [NS]). When the cardiomyostimulator was turned-on a statistically significant increase of the left ventricular ejection fraction was observed either with echocardiography (24.8 +/- 5.8 vs 37 +/- 10.3%; p < 0.05) or radionuclides (20.2 +/- 8.3 vs 33.3 +/- 12.2%; p < 0.05). This significant increase of the ejection fraction has been observed in subsequent studies. Nevertheless the differences when the cardiomyostimulator is turned-on and turned-off have decreased several months after the procedure. A significant increase of the left ventricular outflow velocity (cm/seg) was observed when the generator was turned-on (57.7 +/- 20.4 vs 75.1 +/- 17.8%; p < 0.01). A significant increase of the dP/dt (mmHg/seg) was observed when the generator was turned-on (706.3 +/- 291.5 vs 592.6 +/- 181.6%; [NS]). No significant changes were observed on E wave velocity. A significant decrease of the deceleration time was observed several months after the procedure (p < 0.05). CONCLUSIONS: We believe that dynamic cardiomyoplasty is a safe and valid surgical procedure for some patients with end stage cardiomyopathies as well as in association with Jatene's technique for the management of left ventricular aneurysms. An improvement in functional class is present and a significant increase of the left ventricular systolic function. Nevertheless it is necessary to find new systolic parameters, independent of volumetric calculations, to evaluate the mechanical support of the muscle as well as to determine the long-term pattern of electrical stimulation.

The effects of colloidal and crystalloidal fluids on acidosis and lactacidemia in cardiopulmonary bypass.

During extracorporeal cardiac surgery it is difficult to measure the severity of metabolic acidosis thru arterial bloods gas determination. During bypass surgery a decrease in Colloidosmotic Pressure (COP) may influence the degree of acidosis. We studied 90 patients in whom the following parameters were measured before, 30 minutes after beginning bypass, immediatly after bypass, upon arriving bypass, upon arriving in the Intensive Care Unit (ICU) and upon discharge (ICU): pH, lactic, acid, pO2, pCO2, base excess correlating them with COP. There is a relation between COP and lactic acid, COP = 21.39-0.17 Lactic Acid, with p < 0.001. There is a inverse lineal correlation between COP and blood lactic acid levels. A greater COP was found with a lower blood lactic acid levels. We recommend the use of colloids perfusion as priming fluid instead of electrolytes solutions, specially in patients in extreme ages and also in those in whom a prolonged bypass time is foreseen. This may prevent an increase in blood lactic acid levels.

[Study of colloidal osmotic pressure-total proteins--serum albumin relationship during and after extracorporeal circulation]. / Etude de la relation pression colloïdale osmotique-protéines totales--albuminémie pendant et après la circulation extra-corporelle.

A postoperative increase in the pulmonary extravascular fluid volume (PEFV) and a disturbance of pulmonary gas exchange are regularly observed in patients undergoing cardiac surgery. These alterations, due to a reduction in the colloidal osmotic pressure (COP) increase the morbidity and mortality when crystalloid solutions are infused. This study was based on 90 patients infused with 1,500 cc of crystalloid solution without albumin. The COP, total proteins, albumin and globulin were determined in the plasma preoperatively, during bypass and immediately postoperatively, in order to define a formula allowing calculation of the COP from the plasma proteins to avoid reaching dangerously high figures. The authors concluded that there is a direct correlation between COP and total proteins (total proteins = 1.36 + 0.24 COP) and a potential curve with an adjustment point between COP and albumin (albumin = 0.23 COP0.93). Determination of the COP from globulins is not recommended. The authors elaborated two normograms for everyday clinical use. These formulae allow the calculation of COP in children, elderly subjects and patients in a critical condition, thereby avoiding dangerous levels of COP during infusion of crystalloid solutions.

Dynamic cardiomyoplasty in a patient with end-stage cardiomyopathy.

Dynamic cardiomyoplasty is a relatively new surgical procedure by which a transformed fatigue-resistant skeletal muscle wrapped around the heart is stimulated to contract in synchrony with it, thereby augmenting the ventricular functions of a failing heart. We performed a cardiomyoplasty with latissimus dorsii (LD) in a patient who was refused the heart transplant programme because of pulmonary hypertension and psychosocial contraindications. The patient was 34 years old, functional class grade IV of the New York Heart Association (NYHA), with a three-month history, due to ischemic cardiomyopathy with multiple vessels affected, 10% ejection fraction, arteriolar pulmonary resistance of 7.5 U Wood. Cardiomyoplasty was performed after training the LD muscle for four weeks. One week later the pacemaker was programmed in a DDD mode: amplitude 3.75 V, pulse duration 0.50 ms, AV delay 175 ms. The patient reached functional class grade I-II (NYHA). Inotrope support was discontinued and great clinical improvement was noted. The ejection fraction rose from 10% to 30%. Echocardiographic left ventricular outflow tract velocity increased from 0.33 m/s to 0.60 m/s. These values were compared with radionuclide angiocardiography and echocardiography evaluations. The great clinical improvement and positive changes in left ventricular parameters suggest that cardiomyoplasty is useful in the treatment of some cases of dilated or ischemic cardiomyopathy as an alternative to heart transplantation. Long term follow-up is necessary to evaluate this procedure.