Less surgical site infections in neurosurgery during COVID-19 times-one potential benefit of the pandemic?

Hygiene measures were intensified when the COVID-19 pandemic began. Patient contacts were limited to a minimum. Visitors were either not allowed for a certain period or limited for the rest of the time. The hospital staff began to wear masks and gloves continuously. Clinical examinations and routine wound controls were also performed under intensified hygiene standards. These circumstances result in a limitation of direct physical interactions between the nursing staff, the physicians and the patients. We analyzed to what extent the intensification of hygiene measures affects the rate of surgical site infections (SSI) after neurosurgical procedures. The rate of SSI during the 6-month interval after the beginning of COVID-19 measures was compared with the SSI rate before. The numbers of the period before COVID-19 were analyzed as mean values resulting from the analysis of two separate time periods each consisting of 6 months. The spectrum of surgical procedures was compared. Patient-related risk factors for SSIs were noted. Microorganisms were analyzed. We focused on SSIs occurring at a maximum of 60 days after the primary surgery. Overall, in the two respective 6-month periods before COVID-19, a mean of 1379 patients was surgically treated in our institution. After the beginning of COVID-19 (starting from 04/2020) our surgical numbers dropped by 101, resulting in a total number of 1278 patients being operated after 03/2020 until 09/2020. The SSI rate was 3.6% (03/2019-09/2019, 50 SSIs) and 2.2% (09/2019-03/2020, 29 SSIs), resulting in a mean of 2.9% before COVID-19 began. After the beginning of COVID-19 hygiene measures, this rate dropped to 1.4% (16 SSIs) resembling a significant reduction (p=0.003). Risk factors for the development of SSI were present in 81.3% of all patients. Pre- and post-COVID-19 patient groups had similar baseline characteristics. The same holds true when comparing the percentage of cranial and spinal procedures pre- and post-COVID-19 (p=0.91). Comparing the numbers (p=0.28) and the species (p=0.85) of microorganisms (MO) causing SSI, we found a similar distribution. Despite equal demographics and characteristics of SSI, the rate of SSI dropped substantially. This argues for an effective reduction of postoperative SSI resulting from the implementation of strict hygiene measures being established after the beginning of the COVID-19 pandemic. We therefore advocate continuing with strict and intensive hygiene measures in the future.

Sonda de Foley modificada para infusión tópica de anestésico y oxigenación en intubación difícil / Modified Foley catheter for the topical infusion of anaesthetic and oxygenation in a difficult intubation

No disponible

Endothelial dysfunction in gestational hypertension induced by catechol-O-methyltransferase inhibition.

The present study evaluated whether catechol-O-methyltransferase inhibition in pregnant rats results in increased blood pressure and vascular endothelial dysfunction as a consequence of decreased nitric oxide bioavailability. Pregnant Sprague-Dawley rats were given entacapone (a catechol-O-methyltransferase inhibitor) by gavage from the 10th to the 20th day of pregnancy. Blood pressure was measured by plethysmography in the tail artery. Vascular endothelial function and NO release were assessed both in the absence and in the presence of tempol. Systolic blood pressure increased significantly in pregnant rats treated with entacapone compared with untreated pregnant rats on days 14 (143 ± 4 versus 122 ± 3 mmHg) and 19 of gestation (129 ± 4 versus 115 ± 5 mmHg). Both conductance (aortic rings) and resistance vessels (mesenteric small arterial vessels) from entacapone-treated pregnant rats showed diminished relaxation in response to acetylcholine compared with vessels from vehicle-treated pregnant and virgin rats. In mesenteric arterioles, this endothelial dysfunction was abolished in the presence of l-NAME, indicating that it was caused by reduced NO availability, and it also improved in the presence of tempol, suggesting increased oxidative stress in hypertensive pregnant rats. Endothelial release of nitric oxide induced by calcium ionophore (A23187) was significantly greater in aortas from vehicle-treated pregnant rats than in aortas from pregnant rats given entacapone. This endothelial dysfunction seen in hypertensive rats was prevented by addition of tempol. The present study provides evidence that catechol-O-methyltransferase inhibition in pregnant rats produces arterial hypertension and endothelial dysfunction due to reduced nitric oxide bioavailability.

Effect of tempol on myocardial vascular remodeling in female spontaneously hypertensive rats.

OBJECTIVE: The present study evaluated whether the treatment with the superoxide anion dismutase mimetic tempol prevents the worsening in hypertension and in myocardial vascular remodeling induced by ovariectomy in female spontaneously hypertensive rats (SHR). METHODS: Experiments were performed in ten week old female SHRs randomly assigned to the groups: intact (INT: given vehicle; INT+T: treated with tempol, 90 mg/kg/day), ovariectomized (OVX: vehicle and OVX+T: tempol, respectively) and ovariectomized treated with 17ß-estradiol (OVX+E2 and OVX+E2+T). Evolution of systolic blood pressure (SBP) was determined every other week in lightly restrained awake rats using a noninvasive computerized tail-cuff plethysmography system. At 18 weeks of age the heart was excised and structural changes in histopathological sections of coronary vessels were quantified on a computerized imaging system analyzer. RESULTS: SBP was significantly lower in female SHRs treated with tempol compared to the values measured in untreated animals. In the vascular remodeling of myocardial arterioles, OVX+T rats had a lower media cross sectional area and media-to-lumen ratio than those observed in the OVX SHR. Interestingly, treatment with tempol in the presence of estradiol (in female INT and OVX+E2 SHR ) increased media cross sectional area and wall-to-lumen ratio of myocardial arterioles, despite the fact that it lowered arterial pressure in those groups. CONCLUSIONS: These results indicate that tempol prevents arterial hypertension and blunts myocardial vascular remodeling in ovariectomized SHR. Paradoxically, when tempol is given in presence of estradiol it has a detrimental effect on myocardial arteriolar remodeling.

Novedades en el uso clínico del Sugammadex / New on the clinical use Sugammadex give

El uso del sugammadex en la práctica clínica ha producido una revolución en el campo de la reversión del bloqueo neuromuscular no despolarizante (BNMND) del grupo de los aminoesteroideos, especialmente rocuronio y vecuronio. Se exponen las últimas novedades en el uso clínico del sugammadex en las poblaciones y patologías especiales, junto con las últimas publicaciones de ensayos clínicos y nuestra experiencia como centro de referencia en la monitorización del bloqueo neuromuscular, así como las nuevas posibilidades terapéuticas del fármaco y las situaciones clínicas con las que el anestesiólogo puede encontrarse en su práctica clínica. Se precisan todavía estudios para poder conocer todas las posibilidades de los usos clínicos del sugammadex en la práctica anestésica. Igualmente, hay un amplio margen para la investigación y el desarrollo de nuevas publicaciones de un fármaco que podría reducir a cero los problemas de la curarización residual, siendo su principal inconveniente su elevado precio(AU)

The use of sugammadex in clinical practice has been a revolution in the field of neuromuscular blockade reversal of no depolarizing (BNMND) group of the aminosteroid, especially rocuronium and vecuronium. We describe the latest developments in clinical use of sugammadex in special populations and conditions, the latest publications of clinical trials and our experience as a reference center for monitoring of neuromuscular blockade, and moreover new therapeutic possibilities of the drug for different clinical situations that the anaesthesiologist can be found in their clinical practice. Studies are required to know all possibilities of clinical use of sugammadex in anaesthetic practice. Furthermore, there are great possibilities for research and development of new publications of a drug that could reduce to zero problems of residual curarization. However, the high price it is the main disadvantage(AU)

Utilidad clínica y monitorización del consumo metabólico de oxígeno en anestesia / No disponible

La calorimetría indirecta puede ser un indicador de la evolución homeostática durante la cirugía. El estrés incrementa el consumo de oxígeno (VO2) y durante la anestesia se produce un descenso del VO2 derivado de la ausencia de energía cinética. Esto es un reflejo del metabolismo celular ante el trauma quirúrgico y la anestesia. Se necesitan más estudios para conocer cuál de los sistemas de medición de VO2 sea el más idóneo en anestesia, y cuáles pueden ser los valores límites de VO2 a partir de los que el anestesiólogo deba plantearse la actuación inmediata o evitar llegar a ellos (AU)

Indirect calorimetry could be an indicator of homeostatic changes during surgery. Stress increases oxygen consumption (VO2) and during anesthesia there is a decrease of VO2 arises from the absence of kinetic energy. The answer is cellular metabolism to the surgical trauma and anesthesia. More studies are necessary to know which of the VO2 measurement systems is the most appropriate in anesthesia, and what may be the limiting values of VO2 from which the anesthesiologist must consider immediate action or avoid making them (AU)

Recuperación y reinfusión de hematíes durante el postoperatorio / No disponible

El desarrollo de técnicas quirúrgicas cada vez más complejas, principalmente en cirugía cardiovascular y ortopédica, cirugía oncológica, trasplantes y pacientes politraumatizados han intensificado el aumento de las demandas de transfusiones. En los últimos años, se ha hecho necesario limitar al máximo la transfusión de sangre homóloga por los posibles efectos adversos de tipo inmunológico, e infeccioso por virus y priones. Recientemente, se han desarrollado nuevas medidas terapéuticas con el fin de reducir al mínimo la utilización de sangre homóloga, principalmente en cirugía programada, entre las que destacan las diferentes modalidades de autotransfusión postoperatoria (AU)

The development of surgical techniques increases complexity, particularly in cardiovascular and orthopedic surgery, cancer surgery, transplants and patients with multiple injuries has intensified the growing demands of transfusions. In recent years it has become necessary to minimize homologous blood transfusion by the possible adverse effects of immunological, and infection by viruses and prions. Recently, we have developed new therapeutic measures to minimize the use of homologous blood, mainly in elective surgery, among which the different modalities of postoperative autotransfusion (AU)

2-Methoxyestradiol attenuates hypertension and coronary vascular remodeling in spontaneously hypertensive rats.

OBJECTIVES: Accumulating data provide evidence that some metabolites of 17beta-estradiol are biologically active and mediate multiple effects on the cardiovascular and renal systems. We investigated the effect of 2-methoxyestradiol (an active metabolite of estradiol with non-feminizing activity) on the development of hypertension and myocardial vascular remodeling in male and female ovarectomized SHR. METHODS: Rats were divided into five groups: intact females, ovarectomized (OVX), OVX+ 2-methoxyestradiol (2ME), control males, and male+2ME. Systolic blood pressure was determined from 10 to 18 weeks. Structural changes in coronary vessels were quantified by an image analyzer. Immunoblotting of phosphorylated ERK1/2 and NADPH oxidase activity were performed on mesenteric arteries. RESULTS: Treatment with 2ME reduced the increase in systolic blood pressure in male and ovarectomized rats to values not different from those obtained in intact females. Myocardial arterioles and small arteries showed significant increases in wall-to-lumen ratio and perivascular fibrosis in male and ovarectomized rats when compared with intact females. NADPH oxidase activity was increased in mesenteric arteries from males and ovarectomized females as compared with intact females. Finally, the expression of phosphorilated ERK1/2 were significantly higher in mesenteric arteries from male and ovariectomized animals than in those from intact females. Those effects of ovarectomy and gender differences were totally or partially prevented by treatment with 2-methoxyestradiol. CONCLUSIONS: These data demonstrate that 2-methoxyestradiol protects the vasculature from hypertension-induced myocardial arterial remodeling in male and ovarectomized SHR, and that might be in part related to decreased superoxide generation and ERK1/2 activation.

Monitorización intratraqueal de gases en anestesia / Intratracheal gases monitoring in anaesthesia

Los avances tecnológicos en el análisis de gases y su incorporación a todas las máquinas actuales de anestesia han permitido la monitorización de los agentes halogenados en la anestesia inhalatoria. El primer descubrimiento de la monitorización intratraqueal encontró que el ETCO2 intratraqueal era muy similar a los valores alveolares de ETCO2 porque sus valores eran casi los mismos que los valores arteriales. Además estos eran diferentes a los valores extratraqueales aunque existía una buena correlación. Sin embargo, las diferencias intra- y extratraqueales de los gases halogenados y el N2O no fueron estudiados. Recientemente se han descubierto diferencias significativas en la monitorización intratraqueal de gases. Este tipo de monitorización puede ser muy útil en el futuro en pacientes críticos, pediátricos y ofrecer un buen control del Et de los vapores halogenados cuando no se dispone de sistemas de monitorización de hipnosis. Son analizadas las ventajas e inconvenientes de este tipo novedoso de monitorización intratraqueal con un prometedor futuro (AU)

Technology advantages in gases analyse and their supply inmost anaesthesia machines have improved halogenated agents monitoring in inhaled anaesthesia. The first discovering about endotracheal monitoring found intratracheal ETCO2 were very similar to alveolar ETCO2 because their values were almost the same to arterial values. Moreover these ones are different to extratracheal values but there were good correlation level. However, intra and extratracheal differences of halogenated gases and N2O were not studied. Lately, it has discovered significant differences in intratracheal gases monitoring during paediatric anaesthesia. This kind of monitoring can be very useful in the future in critical, paediatric patients and offers a good control of Et halogenated vapors when we don’t have hypnosis monitoring. Advantages and disadvantages are studied of this new intratracheal monitoring system with a promised future (AU)

Echocardiographic evaluation of the evolutionary changes after heart transplantation.

AIM: To undertake an evolutionary analysis of echocardiographic examinations carried out during follow-up of cardiac transplant patients. MATERIALS AND METHODS: The study included 193 consecutive patients transplanted between August 1998 and December 2004. We excluded pediatric, cardiopulmonary, and repeat transplants. Four echocardiographic examinations were analyzed per patient (first, second, third quarter and the last study carried out; average time from transplant: 1115 +/- 681 days). The total number of examinations was 772. The evaluated variables were thickness of walls and diameters of the cavities, systolic and diastolic functions, pericardial effusion, and number of rejections. RESULTS: The isovolumetric relaxation time showed reduced values during early echocardiography with subsequent increases during evolution (first echocardiogram: 92 +/- 16 vs final echocardiogram 101 +/- 16 ms; P < .0001). Right ventricular function showed initial deterioration with subsequent recovery (first echocardiogram: 16% vs final echocardiogram: 8%; P < .05); moreover, the existence of delayed malfunction of the right ventricle was correlated with a higher incidence of transplant rejection (P < .01). Pericardial effusion was initially present with a tendency to reduce over time (first echocardiogram: 58% vs final echocardiogram: 12%; P < .0001). There was no difference in the other variables. CONCLUSIONS: Cardiac transplant patients undergo evolutionary echocardiogram alterations that were mainly early and normalized as of the first quarter. The most usual changes in this period were restrictive isovolumetric behavior accompanied by some degree of depressed right ventricular function. Right ventricular malfunction during late evolution was correlated with a higher incidence of transplant rejection during follow-up.

Efecto de la ovariectomía sobre la estructura y función cardiovascular en ratas hipertensas / Effect of ovariectomy on cardiovascular structure and function in hypertensive rats

Introducción. El objetivo del presente estudio es investigar los efectos de la ovariectomía en el remodelado vascular miocárdico y en la función cardíaca en ratas hipertensas. Material y métodos. Los experimentos se realizaron en animales de 18 semanas: ratas ovariectomizadas en la semana 10 espontáneamente hipertensas (SHR-OVX), hipertensas intactas (SHR) y controles normotensos (WKY).El remodelado vascular miocárdico se evaluó por medio de la medida del grosor de la pared vascular y el grado de fibrosis perivascular de arteriolas miocárdica. Para valorar la función sistólica in vivo se realizaron curvas de gasto cardíaco a diferentes niveles de presión auricular derecha por sobrecarga aguda de volumen. Como un índice de la función diastólica se estudió in vitro la distensibilidad pasiva de la pared ventricular, utilizando curvas de sobrecarga de volumen intraventricular frente a cambios en la presión intraventricular. Resultados Los SHR presentan, en comparación con el grupo WKY, un aumento del grosor de la pared vascular (p < 0,05) y del grado de fibrosis de los vasos miocárdicos (p< 0,01); ambos cambios vasculares se agravan con la ovariectomía (p < 0,01). Frente a aumentos de presión en aurícula derecha a 3, 6 y 9 cmH2O se produce en todos los grupos experimentales un aumento del índice cardíaco. Este aumento de la función sistólica es, comparado con el grupo WKY, significativamente mayor (p<0,01) en SHR y SHR-OVX. Discusión. Sin embargo, dado que entre ambos grupos no existen diferencias significativas parece que la ovariectomía no modifica la función sistólica. La medida de la distensibilidad pasiva ventricular, valorada por nuestra técnica, indica que ésta es significativamente (p<0,05) menor en los animales ovariectomizados. Estos resultados sugieren que en los animales hipertensos la insuficiencia ovárica experimental agrava el remodelado vascular que ya está presente en la hipertensión y que disminuye la distensibilidad pasiva ventricular sin modificar la función sistólica cardíaca (AU)

17beta-estradiol prevents oxidative stress and decreases blood pressure in ovariectomized rats.

In this study, we tested whether estrogen deficiency is associated with oxidative stress and decreased nitric oxide (NO) production, which could be responsible for an increased blood pressure in ovariectomized rats. Hemodynamic studies were performed on conscious, chronically instrumented rats. Chronic estrogen replacement on ovariectomized rats lowered blood pressure approximately 13 mmHg, from 119 +/- 3 mmHg in ovariectomized rats to 106 +/- 3 mmHg in ovariectomized-treated rats; it was also accompanied by an increase in cardiac index and vascular conductance, achieving hemodynamic values similar to those shown by sham-operated rats. N(G)-nitro-L-arginine methyl ester administration lowered significantly less the vascular conductance (0.14 +/- 0.01 vs. 0.22 +/- 0.03 and 0.26 +/- 0.01 ml. min(-1). mmHg(-1)/100 g; P < 0.05) in ovariectomized rats than in the sham-operated and estrogen-treated ovariectomized rats, respectively. Estrogen replacement prevented the lower plasma levels of nitrites/nitrates observed in ovariectomized rats. The lower plasma total antioxidant status and reduced thiol groups and the increase in plasma lipoperoxides presented in ovariectomized animals were reestablished with the estrogen treatment. These results show that estrogen administration decreases blood pressure and increases vascular conductance in ovariectomized rats. This effect may be related to an increase in NO synthesis and/or preventing oxidative stress, then improving endothelial function.

Role of angiotensin II in modulating the hemodynamic effects of nitric oxide synthesis inhibition.

This study examined the role of ANG II in modulating the increase of hematocrit and vascular permeability that follows nitric oxide (NO) synthesis blockade, that are contributing to the decrease in cardiac index (CI) in conscious, chronically catheterized rats. Pretreatment with losartan attenuated the N(omega)-nitro-L-arginine methyl ester (L-NAME)-induced increase in total peripheral resistance by 26% and also blunted the fall in CI (28%) and stroke volume. L-NAME produced an increase in hematocrit (4.5%) and in (125)I-labeled albumin content in the heart and small intestine in untreated rats, but the increase was prevented in rats pretreated with losartan. Furthermore, L-NAME induced a transient increase of plasma protein concentration and tissue intestinal blood flow, which was abolished in rats given losartan. The results of the present study indicate that the systemic hemodynamic responses, the fall in plasma volume, and the increase in albumin escape observed after inhibition of NO synthesis are in part the consequence of unmasking the actions of endogenous ANG II. These data suggest a physiological role for NO by restraint of the vascular actions of the renin-angiotensin system.

Effect of N-acetylcysteine on vascular endothelium function in aorta from oophorectomized rats.

1. Experiments were performed to examine and to compare vascular endothelial function in aortic rings from oophorectomized and from ovary-intact rats and to test the effect of thiol compound as N-acetylcysteine on endothelial function. 2. In precontracted aortic rings from oophorectomized and intact rats, vascular endothelial function was evaluated by measuring changes in isometric force in response to cumulative doses of superoxide dismutase, acetylcholine and sodium nitroprusside. 3. In studies designed to assess the tone-related release of nitric oxide from aortic rings moderately precontracted with phenylephrine, superoxide dismutase produced a lower concentration-related relaxant response in aortic rings from oophorectomized rats than from ovary intact rats. 4. Acetylcholine caused a concentration- and endothelium-dependent relaxation of less magnitude in aortic rings from oophorectomized animals compared with those from ovary-intact rats. Addition of N-omega-nitro-L-arginine methyl ester eliminated the relaxation induced by both superoxide dismutase and acetylcholine. 5. No differences between groups were noticed in the concentration-relaxation curve induced by sodium nitroprusside. 6. Preincubation with N-acetylcysteine normalized the depressed vasorelaxant response to acetylcholine in the aortic rings from oophorectomized rats, whereas the concentration-response curve for acetylcholine in aortic rings from ovary-intact rats did not alter. 7. These results suggest that the absence of ovary estrogens is associated with a vascular endothelium dysfunction that can be reverted by addition of N-acetylcysteine, a thiol-containing compound with a free radical scavenger effect.

[Study of patients admitted to a telemetry unit]. / Estudio de pacientes ingresados en una unidad de telemetría.

The current situation of the telemetry unit of Vigil de Quiñones Hospital was studied. Telemetry indications, results, and problems observed since the unit was inaugurated were studied to determine the usefulness of telemetric heart rate monitoring and centralized surveillance in an intensive care unit (ICU) in detecting severe arrhythmias, controlling antiarrhythmic treatment, and evaluating why and to what extent telemetry is clinically useful. In our center, telemetry is used to monitor patients with well-established needs. In most cases, arrhythmias are monitored, most frequently premature ventricular complexes, sinus bradycardia and supraventricular tachycardia. Telemetry was useful in arrhythmia treatment and the follow-up of patients with temporary or permanent pacemakers. In a significant percentage of patients (8.62%), telemetry was the key to their ICU admission and, possibly, their survival. There were generally few problems with signal transmission.

Protective effect of N-acetyl-L-cysteine on the renal failure induced by inferior vena cava occlusion.

BACKGROUND: Renal ischemia is produced during orthotopic liver transplantation when the inferior vena cava is clamped above the renal veins (inferior vena cava occlusion [IVCO]), and it often leads to postoperative renal failure. Although free radicals and nitric oxide (NO) have been implicated in the pathogenesis of ischemic renal failure, the effect of free radical scavengers in this model is unknown. METHODS: The effects of N-acetyl-L-cysteine (NAC), a free radical scavenger, on the acute renal failure that follows IVCO were evaluated in pentobarbital-anesthetized dogs. The effect of NO synthesis inhibition with NG-nitro-L-arginine methyl ester (NAME) was also studied. Renal vascular endothelial function was tested by infusing acetylcholine (Ach) into the renal artery before the ischemia and during reperfusion. RESULTS: Renal failure developed during IVCO and persisted during reperfusion in all groups. However, in NAC-pretreated dogs, the glomerular filtration rate recovered progressively, reaching 31% of basal preischemic values 150 min after reperfusion. During reperfusion, fractional excretion of sodium increased above preischemic values only in the control group, which indicates a beneficial effect of NAC and NAME on the tubular dysfunction observed during reperfusion. The renal response to Ach was abolished in control dogs and in animals given NAME during reperfusion, which indicates endothelial dysfunction. However, in NAC-pretreated dogs, the renal response to Ach was preserved during reperfusion. CONCLUSIONS: These results demonstrate that NAC ameliorates the renal failure and renal endothelial dysfunction induced by IVCO. This protective effect was abolished by NAME, which suggests that NO is involved in the beneficial effects of NAC. These data also suggest that the use of NAC could be beneficial in ameliorating the acute renal failure observed after orthotopic liver transplantation.

Role of nitric oxide on the central hemodynamic response to acute volume expansion in the pregnant rat.

OBJECTIVES: Our hypothesis was that during pregnancy nitric oxide acts as mediator in the hemodynamic response to volume expansion. STUDY DESIGN: The study was performed on 12 rats on days 19 to 20 of pregnancy. Six rats were injected intravenously with hexamethonium bromide plus the inhibitor of nitric oxide synthase L-nitro-arginine methyl ester. For a control group, six rats were injected with hexamethonium bromide plus the L-nitro-arginine methyl ester vehicle. A volume expansion (1.2% body weight) was performed in both groups by intravenous infusion of bovine albumin (6%) solution. RESULTS: In the control group volume expansion induced a hyperdynamic circulation characterized by increased cardiac output, decreased total vascular resistance, and no change in arterial pressure; however, in the study group volume expansion induced a pressor response without hyperdynamic circulation. CONCLUSION: During pregnancy volume expansion induces a hyperdynamic circulatory state possibly mediated by nitric oxide release. A defect in the release of nitric oxide may be responsible for an inadequate hemodynamic response to volume expansion.

Hemodynamic effect of 17 beta-estradiol in absence of NO in ovariectomized rats: role of angiotensin II.

Previous reports correlate plasma levels of estrogen with increased nitric oxide (NO) production. To investigate whether the hemodynamic effects of estrogens are mediated by NO, we compared the hemodynamic changes induced by 17 beta-estradiol (100 micrograms/kg) in the absence and presence of the NO synthesis inhibitor N omega-nitro-L-arginine methyl ester (L-NAME). All protocols were performed in ovariectomized, conscious rats. Estradiol alone resulted in no significant changes in cardiac index (CI) or mean arterial pressure (MAP). However, in the presence of L-NAME, estradiol induced a significant increase in total peripheral resistance (TPR) of 37.3 +/- 11.7% and a decrease in CI of 27 +/- 4.9%, without changes in MAP. Previous blockade of angiotensin II AT1 receptors with losartan prevented any change in CI and TPR induced by 17 beta-estradiol in the presence of L-NAME. These observations suggest that NO is necessary to offset a vasoconstrictor action of angiotensin II, which is stimulated by estradiol administration.

Thiocoraline, a new depsipeptide with antitumor activity produced by a marine Micromonospora. I. Taxonomy, fermentation, isolation, and biological activities.

A novel bioactive depsipeptide, thiocoraline, was isolated from the mycelial cake of a marine actinomycete strain L-13-ACM2-092. Based on morphological, cultural, physiological, and chemical characteristics, strain L-13-ACM2-092 was ascribed to the genus Micromonospora. Thiocoraline showed a potent cytotoxic activity against P-388, A-549 and MEL-28 cell lines, and also a strong antimicrobial activity against Gram-positive microorganisms. This compound binds to supercoiled DNA and inhibits RNA synthesis.