Hepatic malonyl-CoA synthesis restrains gluconeogenesis by suppressing fat oxidation, pyruvate carboxylation, and amino acid availability

Acetyl-CoA carboxylase (ACC) promotes prandial liver metabolism by producing malonyl-CoA, a substrate for de novo lipogenesis and an inhibitor of CPT-1-mediated fat oxidation. We report that inhibition of ACC also produces unexpected secondary effects on metabolism. Liver-specific double ACC1/2 knockout (LDKO) or pharmacologic inhibition of ACC increased anaplerosis, tricarboxylic acid (TCA) cycle intermediates, and gluconeogenesis by activating hepatic CPT-1 and pyruvate carboxylase flux in the fed state. Fasting should have marginalized the role of ACC, but LDKO mice maintained elevated TCA cycle intermediates and preserved glycemia during fasting. These effects were accompanied by a compensatory induction of proteolysis and increased amino acid supply for gluconeogenesis, which was offset by increased protein synthesis during feeding. Such adaptations may be related to Nrf2 activity, which was induced by ACC inhibition and correlated with fasting amino acids. The findings reveal unexpected roles for malonyl-CoA synthesis in liver and provide insight into the broader effects of pharmacologic ACC inhibition.

PRESTOapp for health workers with mental health symptoms related to the COVID-19 pandemic

Introduction

The COVID-19 pandemic has caused a significant impact on the mental health of health workers that has brought many hospitals to launch immediate preventive mental health programs.

Objectives

(1) To adapt and enhance a smartphone app (PRESTOapp) for health workers with mental health symptoms related to the COVID-19, and (2) to demonstrate its potential effectiveness in significantly reducing anxiety-depressive and PTSD symptoms in this population. We aim to incorporate Natural Language Processing (NLP)-based techniques in a chatbot user-interface that will enable a more personalized and accurate monitoring and intervention.

Methods

An 18-months study with a 6-months preliminary phase to adapt PRESTOapp to health workers, enhance it with NLP-based techniques and chatbot user-interface, and evaluate its feasibility, and effectiveness in 12-months.

Results

PRESTOapp has the potential to provide a prompt, personalized and integral response to the mental health demand due to the COVID-19. It will help by providing an innovative digital platform, that will allow remote monitoring of the symptoms course, provide brief psychotherapeutic interventions, and detect urgent situations. If the preliminary results of this study point to a potential effectiveness of the intervention, PRESTOapp may be easily adapted to the general population.

Conclusions

PRESTOapp may be one of the key digital platforms that may help preventing and treating potentially severe mental health consequences. Considering the unresolved problem of burnout in health workers even before the COVID-19, this project will develop the necessary technology for implementing cost-effective mental health solutions, not only during the pandemic.

Disclosure

No significant relationships.

Myocardial work still reflect function while strain simply measure deformation when afterload increases

Introduction

Global longitudinal strain is recommended by the European Society of Cardiology to detect subclinical left ventricular (LV) dysfunction, but is markedly load-dependent. Myocardial work was recently introduced as a clinical tool to study LV function by pressure-strain analysis. Since myocardial work incorporates afterload, it is assumed to be less afterload-dependent than strain, but the relationship with afterload is incompletely understood.

Hypothesis

Myocardial work is a better tool than strain, to measure myocardial function during elevated afterload.

Methods

In eleven anesthetized dogs, LV volume and longitudinal strain were measured by sonomicrometry, and pressure by micromanometry. Myocardial work was calculated by pressure-strain analysis. Additionally, stroke work was calculated as the area of the pressure-volume loop. Afterload was instantly increased by aortic constriction using a pneumatic cuff around the ascending aorta. Measurements were performed at baseline, during moderate- and marked afterload elevations.

Results

Table 1 summarizes the results. LV pressure (LVP) successively increased with moderate and marked afterload elevation, while longitudinal strain was successively reduced. Myocardial work and stroke work, on the other hand, increased with moderate afterload elevation, but was then reduced at marked afterload increase (Figure 1 and Table 1). Stroke volume and ejection fraction corresponded to strain and were reduced with afterload elevation.

Conclusions

Longitudinal strain and myocardial work have qualitatively different responses to increased afterload. While moderate changes in afterload cause reductions in strain that can be falsely interpreted as reductions in contractility, myocardial work increases as it incorporates the increased workload at moderately elevated afterload.

Funding Acknowledgement

Type of funding sources: Public Institution(s). Main funding source(s): The Norwegian Health Association

13Check_RNA: a tool to evaluate 13C chemical shift assignments of RNA

Motivation

Chemical shifts (CS) are an important source of structural information of macromolecules such as RNA. In addition to the scarce availability of CS for RNA, the observed values are prone to errors due to a wrong re-calibration or miss assignments. Different groups have dedicated their efforts to correct CS systematic errors on RNA. Despite this, there are not automated and freely available algorithms for evaluating the referencing of RNA 13 C CS before their deposition to the BMRB or re-reference already deposited CS with systematic errors.

Results

Based on an existent method we have implemented an open source python module to correct 13 C CS (from here on 13Cexp) systematic errors of RNAs and then return the results in 3 formats including the nmrstar one.

Availability and implementation

This software is available on GitHub at https://github.com/BIOS-IMASL/13Check_RNA under a MIT license.

Supplementary information

Supplementary data are available at Bioinformatics online.

Development of urine standard reference materials for metabolites of organic chemicals including polycyclic aromatic hydrocarbons, phthalates, phenols, parabens, and volatile organic compounds

Two new Standard Reference Materials (SRMs), SRM 3672 Organic Contaminants in Smokers' Urine (Frozen) and SRM 3673 Organic Contaminants in Non-Smokers' Urine (Frozen), have been developed in support of studies for assessment of human exposure to select organic environmental contaminants. Collaborations among three organizations resulted in certified values for 11 hydroxylated polycyclic aromatic hydrocarbons (OH-PAHs) and reference values for 11 phthalate metabolites, 8 environmental phenols and parabens, and 24 volatile organic compound (VOC) metabolites. Reference values are also available for creatinine and the free forms of caffeine, theobromine, ibuprofen, nicotine, cotinine, and 3-hydroxycotinine. These are the first urine Certified Reference Materials characterized for metabolites of organic environmental contaminants. Noteworthy, the mass fractions of the environmental organic contaminants in the two SRMs are within the ranges reported in population survey studies such as the National Health and Nutrition Examination Survey (NHANES) and the Canadian Health Measures Survey (CHMS). These SRMs will be useful as quality control samples for ensuring compatibility of results among population survey studies and will fill a void to assess the accuracy of analytical methods used in studies monitoring human exposure to these organic environmental contaminants.

Efficacy and safety of non-operative management of blunt liver trauma

BACKGROUND

The liver is the most frequently affected organ during blunt abdominal trauma. Blunt liver trauma management has changed in the last two decades with the introduction of the computed tomography (CT) scan and non-operative management of stable patients.

OBJECTIVE

To determine the incidence, efficacy, and failure rate of blunt liver trauma non-operative management as well as the risk factors associated with such treatment in a level 1 trauma center in Colombia.

METHODS

We conducted an observational descriptive study on patients with blunt liver trauma who were admitted to a level 1 trauma center in Colombia. The evaluated outcomes were indications of immediate surgical treatment and the success of non-operative management.

RESULTS

A total of 73 patients were studied. The most common mechanism of trauma continues to be motor vehicle crashes. In 14 patients (19.2%), immediate surgical intervention was necessary and we observed a Revised Trauma Score (RTS) above 7.8 and intra-abdominal injuries as risk factors. Three patients died (21.4%). Fifty-nine patients (80.8%) received non-operative management, which failed in seven patients (11.2%). Age, severity of liver injury, and intra-abdominal injuries were not risk factors in the failure of non-operative management. Mortality in the non-operative management group was 1.7%.

CONCLUSION

Non-operative management is the treatment of choice for polytraumatized patients with blunt liver trauma who are hemodynamically stable. Non-operative management is an effective and safe treatment strategy. However, patients with an RTS score under 7.8 and other intra-abdominal non-liver injuries are at increased risk for an immediate surgical intervention.

A Retrospective Review of Association between Clinico-Pathologic Prognostic Factors and Disease Outcome in Node-Positive or High-Risk Node Negative Breast Cancer Patients Treated with Adjuvant Cyclophosphamide, Doxorubicin Followed by Paclitaxel: A Venezuelan Study

Background: Breast cancer is a disease with a biologic and clinical heterogeneity explained by differences in the genetic composition, which translate into variability in estrogen receptor (ER), progesterone receptors (PR), Her2–Neu receptor (HER2) expression and permit to identify subgroups that show different prognoses and that also respond differently to treatment. The goal of this study was to determine disease-free survival (DFS) in relation to clinico-pathologic features and ER/PR/HER2 subgroups, in node-positive or high-risk breast cancer patients in a Venezuelan single institution. Methods: We reviewed data between May 1999 to July 2006, from our breast tumor registry with attention to clinical and pathologic prognostic factors. All patients were treated with either mastectomy or breast conserving surgery-with axillary node assessment for stage and adjuvant chemotherapy with doxorubicin 60mg/m2 and cyclophosphamide 600mg/m2 both IV day 1 x 4 cycles, followed by paclitaxel 175mg/m2 day 1 x 4 cycles every 3 weeks or every 2 weeks. All patient received radiation therapy and adjuvant hormonal therapy when indicated. Disease-free survival (DFS) was measured from the date of biopsy to the date of relapse. DFS was estimated using the univariate Kaplan-Meier method. Twelve clinico-pathologic factors that could influence relapse were selected and analyzed using the Cox Proportional Hazards Model. All analyses were carried out using Stata (version 6.0).Results: A total of 92 breast cancer patients all received adjuvant chemotherapy and radiotherapy, 79% of the patients received hormonal therapy with either Tamoxifen or an Aromatase Inhibitor according to their menopausal status. The median follow-up is 55.42 months (range 9.5-110 months). Median age was 50 years (27-70). Local and distant failures were 3% and 11% respectively. For the overall population, the probability of DFS at 2, 5 and 9 years was respectively 93%, 83% and 83%. The results of univariate analysis showed that the mayor significant prognostic factor for influencing relapse was Estrogen receptor (HR:0.29) (p=0.06). Univariate survival analyses comparing grade of differentiation, stage of disease and number of metastasis in axillary lymph nodes with respect to Disease-free survival were performed and showed no significant difference. Patients with triple negative tumors showed an increased risk of relapse with a significant decrease in 9-year disease-free survival 38.1% (p<0.001) and patients with ER+/PR+/HER2- had the best DFS 90% (p<0.001). Conclusions: Estrogen receptor expression was the most significant biologic prognostic factors for relapse in this population. Triple negative tumors were associated with worse DFS. Different DFS in ER/PR/HER2 subgroups clearly illustrates the heterogeneity of this disease and support the importance of tailored therapy in this era.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 6056.

Interface double-exchange ferromagnetism in the Mn-Zn-O system: new class of biphase magnetism

In this Letter, we experimentally show that the room temperature ferromagnetism in the Mn-Zn-O system recently observed is associated with the coexistence of Mn(3+) and Mn(4+) via a double-exchange mechanism. The presence of the ZnO around MnO(2) modifies the kinetics of MnO(2)-->Mn(2)O(3) reduction and favors the coexistence of both Mn oxidation states. The ferromagnetic phase is associated with the interface formed at the Zn diffusion front into Mn oxide, corroborated by preparing thin film multilayers that exhibit saturation magnetization 2 orders of magnitude higher than bulk samples.

Nanostructure and magnetic properties of the MnZnO system, a room temperature magnetic semiconductor?

The magnetic properties of the system MnZnO prepared by conventional ceramic procedures using ZnO and MnO(2) starting powders are studied and related to the nanostructure. Thermal treatment at 500 °C produces a ferromagnetic phase, although this temperature is not high enough to promote proper sintering; thus the thermally treated compact shows brittle characteristics of unreacted and poorly densified ceramic samples. Scanning electron microscopy and x-ray analysis reveal the appearance of a new phase, most probably related to the diffusion of Zn into MnO(2) oxide nanocrystals. The magnetic properties deviate considerably from what would be expected of an unreacted mixture of ZnO (diamagnetic) and MnO(2) particles (paramagnetic above 100 K and anti-ferromagnetic below that temperature), exhibiting a ferromagnetic like behaviour from 5 to 300 K and beyond mixed with a paramagnetic component. The ferromagnetic phase seems to be originated by diffusion at the nanoscale of Zn into MnO(2) grains. The Curie temperature of the ferromagnetic phase, once the paramagnetic component has been subtracted from the hysteresis loops, is measured to be 450 K. EPR resonance experiments from 100 to 600 K confirm a ferromagnetic to paramagnetic like transition above room temperature for these materials.

Chondroitin sulfate proteoglycan specific to retinal horizontal neurons

ABSTRACT Proteoglycans (PGs) are a diverse group of highly glycosylated macromolecules that are implicated in the development and maintenance of neuronal circuitry. With its highly ordered, layered structure, the retina ideally serves to define the synthesis, processing, and distribution of these molecules within a specific cellular subpopulation. In retinal sections, monoclonal antibody (MAb) 6A2 immunostained a horizontal cell-specific antigen. Antigen 6A2 was expressed within abundant processes in the outer plexiform layer and in rare neurites that extend across the inner nuclear layer to the inner plexiform layer. Ultrastructurally, the antigen was localized to cisternae within horizontal cell somata, along tubulovesicular structures in dendrites, and in the perisynaptic space encircling presynaptic terminals of the cone photoreceptor triad. These findings suggest that this PG is synthesized within the horizontal cells, transported to the terminals, and released into the extracellular spaces just proximal to the synapse. Based on the focal stain in the adjacent photoreceptor cell, it is possible that antigen is pinocytosed by this cell and is concentrated at the ribbon synapse. In Western immunoblots of retinal homogenates, MAb 6A2 recognized a heterogeneous chondroitin sulfate (CS) PG (CSPG) of approximately 400-500 kDa. After sequential enzymatic removal of CS glycosaminoglycans, a major broad band of 300-500 kDa was identified by MAb 1B5, which detects CSPGs that bear uronic acid linked to unsulfated N-acetylgalactosamine as the initial disaccharide in the CS chain. Localization of this PG around presynaptic terminals of the horizontal neuron and at the ribbon synapse suggests that it may play a modulatory and sustaining role at the synapse.

[Reperfusion arrhythmias in valvular patients undergoing extracorporeal surgery and pretreated with captopril]

INTRODUCTION AND OBJECTIVES

After the ischemia-reperfusion process in extracorporeal cardiac surgery there are, among several phenomena, some reperfusion arrhythmias which are influenced by a varied series of mechanisms. These arrhythmias have been related to the release of oxygen-derived free radicals during the first moments of reperfusion. Thus, a previous administration of free-radical scavengers might be beneficial, among which captopril has been included with good results in human studies in vitro and in animals in vivo. The aim of this study was to evaluate the influence of pretreatment with captopril on the prevention of reperfusion arrhythmias in patients undergoing valvular cardiac surgery.

METHODS

30 patients were randomly allocated to pretreatment with either captopril (CTP group, n = 15) or without captopril (CON group, n = 15). Exclusion criteria (left ventricular ejection fraction < 40%, evidence of angiographic coronary disease, prior myocardial infarction and preoperatory myocardial infarction). The dose of captopril administered was 12.5 mg every 8 hours orally, from 24 hours before surgery. A Holter register was used to analyze the ventricular arrhythmias (extrasystoles, salvos, tachycardia and fibrillation) during the first hour of reperfusion. The need for cardioversion was examined and the number of shocks needed. These events were related to changes in blood analyses from coronary sinus samples to determine creatine phosphokinase, activity of the angiotensin converting enzyme and cyclic adenosine monophosphate, before aortic clamping and after the heart was rewarmed.

RESULTS

No significant differences were found in the number of ventricular arrhythmias. 60% of the patients with captopril and only 40% of the patients without it (non significant) had spontaneous defibrillation without electric shock; in those cases in which it was necessary, the number of shocks was less in the captopril group (p < 0.05). Excepting the significant correlation (p < 0.01) that we have found between ventricular fibrillation and the cyclic adenosine monophosphate increase, there is no significant correlation between the other arrhythmias and the analytical data studied.

CONCLUSIONS

These data suggest that captopril, given before cardiac surgery, has little or no protector effect on reperfusion ventricular arrhythmias in extracorporeal cardiac surgery, though in patients treated with captopril there is a greater possibility of spontaneous defibrillation and fewer shocks necessary for defibrillation, without negative effects.

Thoracoscopic partial pericardiectomy in the diagnosis and management of pericardial effusion

BACKGROUND

An effort was made to present our experience with thoracoscopy in the diagnosis and management of pericardial effusions.

METHODS

Twenty-two partial pericardiectomies were performed with the thoracoscopic approach in patients with pericardial effusions, the etiology of which was uremic (n = 7), neoplastic (n = 8), idiopathic (n = 5), septicemia (n = 1), and postpericardiotomy (n = 1). All cases had grade III-IV/IV radiological cardiomegaly and ultrasonographic confirmation of the effusion. We found hemodynamic compromise in 17 patients. The operation, requiring the insertion of three trocars, enabled us to remove a large part (approximately 6 x 10 cm) of the left anterolateral side of the pericardium and aspirate the effusion contents for diagnostic and therapeutic purposes.

RESULTS

In five cases we found coexisting pleural effusions. The pericardial effusion had a mean volume of 817 ml, which was serous in 11 cases, hematic in six, serohematic in four, and purulent in one. Cytology of the pericardial effusion was positive for neoplasia in four cases (one pulmonary neoplasia, two breast carcinomas, and one lymphoma). We observed conversion to grade I/IV cardiomegaly in 16 cases and a return to normality in the other six, with the absence of ultrasonographic effusion in all cases. There was no recurrence during the mean follow-up period of 20.5 months (range: 2-47).

CONCLUSIONS

The thoracoscopic management of pericardial effusions is a simple and effective technique that allows us to create a large pericardial window that drains the effusion definitively, determines its etiology, and explores and treats coexisting pleural lesions, all without recurrences.

Analysis of partial sequences of genes coding for 16S rRNA of actinomycetes isolated from Casuarina equisetifolia nodules in Mexico

Filamentous bacteria isolated from surface-sterilized nodules of Casuarina equisetifolia trees in México were capable of reducing acetylene, a diagnostic test for nitrogenase, but were unable to nodulate their host. Analysis of partial 16S rRNA gene sequences suggests that the Mexican isolates are not Frankia strains but members of a novel clade.

Reversed shunting across the ductus arteriosus or atrial septum in utero heralds severe congenital heart disease

OBJECTIVES

This study was performed to define the significance of Doppler color flow mapping in demonstrating reversal of the direction of the normal physiologic flow across the atrial septum and ductus arteriosus in the human fetus.

BACKGROUND

Reversal of the physiologic shunting across the ductus arteriosus or atrial septum in utero (i.e., left to right) can be readily identified by Doppler color flow mapping, complemented by pulsed and continuous wave Doppler information.

METHODS

We reviewed echocardiograms recorded at our three institutions from 1988 to 1993, which displayed reversal of flow by Doppler color flow in 53 fetuses of gestational age 18 weeks to term. The diagnoses were confirmed by postnatal echocardiography, operation or autopsy. Reversal of shunting was consistently associated with severe heart disease.

RESULTS

Reversed atrial shunting was found with severe left heart obstructive lesions, including 19 with hypoplastic left heart syndrome, 3 with critical aortic stenosis, 2 with double-outlet right ventricle and 1 each with an interrupted aortic arch, atrioventricular septal defect and severe left ventricular dysfunction due to dilated cardiomyopathy. Reversed ductus arteriosus shunting was found with severe right heart obstructive lesions, including nine fetuses with pulmonary atresia, six with severe obstructive tricuspid valve abnormalities, five with severe tetralogy of Fallot, four with Ebstein's anomaly and two with single ventricle and pulmonary stenosis. Associated cardiac lesions were common in both groups. Only 3 of the 15 infants who were delivered alive from the reverse ductus arteriosus shunt group and 4 of 12 from the reverse atrial shunt group still survive.

CONCLUSIONS

The finding of reversed flow by Doppler color flow mapping during fetal life provides a key to subsequent accurate diagnosis and denotes a spectrum of diseases with a very poor prognosis.

Acute treatment with the N-methyl-D-aspartate receptor antagonist MK-801: effect of concurrent administration of haloperidol or scopolamine on preproenkephalin mRNA levels of the striatum and nucleus accumbens of the rat brain

We injected rats three times at 3 h intervals (from 0900 h to 1500 h) with the N-methyl-D-aspartate (NMDA) receptor antagonist MK-801 at 0.1 or 0.5 mg/kg of body weight. Three hours after the last injection, animals were sacrificed and the brains were processed for in situ hybridization histochemistry. Preproenkephalin (PPE) mRNA levels were significantly decreased throughout the caudate-putamen (CPu) and nucleus accumbens (NAc) at the lower dose. The higher dose produced significant decreases only in anterior CPu (aCPu) and NAc. Concurrent administration of the muscarinic cholinergic receptor antagonist scopolamine at 2 or 5 mg/kg neither potentiated nor prevented the effect of MK-801 on PPE mRNA levels in the neostriatum. In contrast, co-administration of haloperidol (dopamine receptor antagonist) with MK-801 blocked the effect of the latter in the NAc, and elevated PPE mRNA levels throughout the CPu. The data demonstrate that the acute effects of glutamate receptor activity on striatal and accumbal PPE mRNA expression via the NMDA receptor can be modulated by the dopaminergic system in the brain of the rat.

Restraint stress reversibly enhances spatial memory performance

The effects of restraint stress on performance of a spatial memory task, the eight arm radial maze, was examined in rats. When stress was given for 6 h/day for 7 days and performance evaluated days 10-13 post stress, no effect on performance was noted; however, daily restraint stress for 13 days caused a small, but significant, enhancement of performance days 10-13 post stress. Stressed rats performed better than controls: their number of correct choices in the first 8 visits was higher than the controls, and stressed rats took fewer total choices to finish the maze than controls. Stress-dependent, enhanced performance does not appear permanent since further maze testing on days 14 and 15 post stress showed no differences between the groups. Performance of the stressed rats significantly correlated with their stress-induced, serum corticosterone levels measured after 6 h of restraint on the last day of restraint, day 13 (r = -0.63, P < 0.05); rats with higher levels of CORT took fewer choices to finish the task. Examination of hippocampal CA3c pyramidal neurons with Golgi techniques showed no effect of stress on the basal or apical dendritic arbors. Since our previous study showed that 21 days of restraint stress is associated with impaired spatial memory performance (10), these results suggest that the duration of stress may differentially affect learning/memory with shorter periods of stress serving an adaptive function while longer durations causing maladaptive changes.

Attenuation of neostriatal preproenkephalin and preprotachykinin mRNA abundance by chronic treatment with the kainate/quisqualate receptor antagonist 6-cyano-7-nitroquinoxaline-2,3-dione in the rat brain

The present investigation assessed the effect of chronic blockade of kainate/quisqualate binding sites with 6-cyano-7-nitroquinoxaline-2,3-dione (CNQX) on preproenkephalin (PPE) and preprotachykinin (PPT) mRNA abundance in the neostriatum of the rat brain. Daily injection of CNQX for seven consecutive days decreased PPE mRNA abundance approximately 25% below vehicle-injected controls in dorsolateral, dorsomedial, anterior caudate-putamen (dlCPu, dmCPu and aCPu, respectively) and nucleus accumbens (NAc). Similarly, PPT mRNA abundance was significantly decreased in dlCPu, dmCPu and aCPu but not in the accumbens. The data demonstrate that non-NMDA receptor activity modulates basal levels of expression of PPE and PPT mRNAs in the neostriatum of the rat brain.

Ventricular function during liver reperfusion in hepatic transplantation. A transesophageal echocardiographic study

Postreperfusion syndrome (PRS) is the most dramatic and acute hemodynamic alteration that occurs in OLT. Our aim was to determine heart function by hemodynamic monitoring and transesophageal echocardiography during PRS. We studied 24 nonconsecutive patients allocated to 2 groups: group A (n = 8), patients with PRS, and group B (n = 16), patients without PRS. Usual hemodynamic data were obtained simultaneously with transesophageal echocardiography recording of the left ventricular imaging in 4 different stages: after induction of anesthesia, 5 min before the end of the anhepatic phase, between 2 and 5 min after reperfusion, and 5 min after graft reperfusion. The hemodynamic and echocardiographic findings during reperfusion were (group A vs. group B patients): mean arterial pressure, 50.0 +/- 15.2 vs. 74.7 +/- 13.9 mmHg (P < 0.01); pulmonary capillary wedge pressure, 12.7 +/- 6.1 vs. 13.9 +/- 5.7 mmHg (NS); left ventricular ejection fraction, 79.6 +/- 9.3 vs. 83.4 +/- 9.4% (NS); left ventricular end diastolic volume index, 35.5 +/- 12.7 vs. 54.7 +/- 21.3 ml/m2 (P < 0.05); and stroke volume index, 27.9 +/- 8.9 vs. 45.5 +/- 15.9 ml/m2 (P < 0.01). There was a mild decrease in left ventricular compliance in group A. We found no alteration in left ventricular function that can justify PRS. The hemodynamic changes during PRS seemed to be caused by an insufficient increase in preload after unclamping.

Repeated stress causes reversible impairments of spatial memory performance

Restraint stress, 6 h/day for 21 days, caused an impairment, during acquisition, of the performance of a spatial memory task, the eight-arm radial maze. The impairment was reversible, temporally limited and blocked by phenytoin, a blocker of excitatory amino acid action, or tianeptine, an antidepressant, which lowers extracellular serotonin. These effects on behavior parallel the reversible stress-induced atrophy of dendrites of hippocampal CA3 neurons that are also blocked by the drugs.

Cardiac ultrasonography in structural abnormalities and arrhythmias. Recognition and treatment

Fetal cardiac ultrasonography has become an important tool in the evaluation of fetuses at risk for cardiac anomalies. It can both guide prenatal treatment and assist the management and timing of delivery. We recommend that a fetal echocardiogram be done when there is a family history of congenital heart disease; maternal disease that may affect the fetus; a history of maternal drug use, either therapeutic or illegal; evidence of other fetal abnormalities; or evidence of fetal hydrops. The optimal timing of evaluation is 18 to 22 weeks' gestation. An entire range of structural cardiac defects can be visualized prenatally, including atrioventricular septal defect, ventricular septal defect, cardiomyopathy, ventricular outlet obstruction, and complex cardiac defects. The outcome for a fetus with a recognized abnormality is unfavourable, with less than 50% surviving the neonatal period. Fetal cardiac arrhythmias are also a common occurrence, 15% in the series described here. Premature atrial or ventricular contractions are most commonly seen and usually require no treatment. Supraventricular tachycardia can result in hydrops and require in utero treatment to prevent fetal demise. Complete heart block, particularly in association with structural heart disease, has a poor prognosis for fetal survival.

Pulmonary arterial hypertension and cor pulmonale associated with chronic domestic woodsmoke inhalation

We describe the clinical, radiologic, functional, and pulmonary hemodynamic characteristics of a group of 30 nonsmoking patients with a lung disease that may be related to intense, long-standing indoor wood-smoke exposure. The endoscopic and some of the pathologic findings are also presented. Intense and prolonged wood-smoke inhalation may produce a chronic pulmonary disease that is similar in many aspects to other forms of inorganic dust-exposure interstitial lung disease. It affects mostly country women in their 60s, and severe dyspnea and cough are the outstanding complaints. The chest roentgenograms show a diffuse, bilateral, reticulonodular pattern, combined with normalized or hyperinflated lungs, as well as indirect signs of pulmonary arterial hypertension (PAH). On the pulmonary function test the patients show a mixed restrictive-obstructive pattern with severe hypoxemia and variable degrees of hypercapnia. Endoscopic findings are those of acute and chronic bronchitis and intense anthracotic staining of the airways appears to be quite characteristic. Fibrous and inflammatory focal thickening of the alveolar septa as well as diffuse parenchymal anthracotic deposits are the most prominent pathologic findings, although inflammatory changes of the bronchial epithelium are also present. The patients had severe PAH in which, as in other chronic lung diseases, chronic alveolar hypoxia may play the main pathogenetic role. However, PAH in wood-smoke inhalation-associated lung disease (WSIALD) appears to be more severe than in other forms of interstitial lung disease and tobacco-related COPD. The patients we studied are a selected group and they may represent one end of the spectrum of the WSIALD.

Cardiac dimensions determined by cross-sectional echocardiography in the normal human fetus from 18 weeks to term

Assessment of cardiac dimensions of the chambers, great arteries and veins in the human fetus is important to distinguish abnormal dimensions from normal. This study establishes normal values based on cross-sectional echocardiographic measurements over the gestational period where these measurements may be clinically useful. Ventricular and atrial dimensions were measured from the 4-chamber view, the short-axis dimension immediately below the mitral and tricuspid valve leaflets in diastole, and the long axis from the closed apposed atrioventricular valves to their respective apices. The ventricular walls and septum were measured at the level at which cavity dimensions in diastole were measured, defining both the left and right ventricular wall thickness, as well as that of the ventricular septum. Furthermore, the long axis of the right and left atria was measured from the center of the apposed atrioventricular valve leaflets to the posterior atrial wall, and the sizes of the atrial chambers were defined using their widths at the prospective broadest points through the area of foramen ovale. From a variety of views, diameters were measured at maximal expansion of the main, left and right pulmonary arteries, the ductus arteriosus, and the superior and inferior venae cavae. The data were evaluated longitudinally from 18 weeks to term, and regression analysis was performed using the best fit of a linear or polynomial equation. The data provide a means for evaluating the normal sizes and dimensions of the fetal heart chambers, as well as the thickness of the ventricular walls and septum.

[Detection of early occlusion of aortocoronary by-passes. Usefulness of a non-angiographic method]

A total of 83 bypasses were studied. Angiographic results demonstrated occlusion in 3 of 24 bypass of internal mammary artery placed in the anterior descending artery, 2 in the right coronary artery, 1 in the posterolateral of the circumflex and 1 in the first diagonal branch, with a total occlusion average of 8.4% within the first 8 days. We found a good correlation between the coronarographic angiograms and the positivity or negativity of the echo-electrocardiographic tests, during atrial pacing. We believe that this simple method could be done routinely in all the patients after coronary surgery, to decide the need of a new coronary angiogram. Furthermore, this study shows that the occlusion of a single coronary bypass does not produce myocardial infarction, detectable by enzymatic measures or by resting EKG. This method also detects the early post-operatory sinus sick syndrome.

Two dimensional and Doppler echocardiographic diagnosis of bicuspid pulmonary valve

The diagnosis of bicuspid pulmonary valve is usually established postmortem, occurring in 7% of patients with pulmonary stenosis and is usually associated to tetralogy of Fallot or ventricular septal defect. The authors report the case of a 14-year-old girl with patent ductus arteriosus in whom 2-D echocardiography disclosed a pulmonary valve formed of two slightly thickened leaflets that opened with the shape of a dome in systole, and moved under the valve ring plane during diastole. A Doppler examination showed a 21 mmHg transvalvar gradient. These characteristic features suggest that 2-D and Doppler echocardiography are the techniques of choice in the diagnosis of bicuspid pulmonary valve.

[The clinical features of myocardial infarct via "normal" coronary angiography. The experience of the Instituto Nacional de Cardiología]

The end-point of our study was to find clinical differences between patients with myocardial infarction and evident obstructions in coronary angiography, and patients without coronary obstructions. In a 10 years follow-up period, 48 patients with diagnosis of myocardial infarction and normal coronary arteries by angiography (group A) where admitted al hospital. We compared this group with 80 patients (group B), randomly selected from all patients with myocardial infarction and evident obstructions in coronarography. Patient age at the ischemic event, familiar history of ischemic heart disease or sudden death, obesity, drug habits, contraception drugs use, and history of migraine and Raynaud's phenomenon were pointed out. Thirty patients from group A were admitted with acute myocardial infarction, and we also analysed in these patients prodromal symptoms, precipitating factors, AMI localisation, serum enzymatic levels, rhythm and/or conduction disturbances, clinical condition, treatment and new ischemic events. Group A patients showed lower age-average, smoking habit, prodromal symptoms and serum CPK levels. They have better ventricular performance parameters and a greater incidence of women. The only different risk factor for ischemic heart disease between both groups was smoking.

[Partial pericardial tamponade immediately after cardiac surgery]

Partial pericardial tamponade is a critical situation frequently misdiagnosed. We describe five patients with this entity during an urgent surgical reintervention performed few hours after the initial one. We found clots compressing cardiac cavities in all, usually in the right atrium. In one of them we found also a clot compressing the left atrium. None of the patients studied had the classical clinical features of cardiac tamponade (Kussmaul's sign: pulsus paradoxus) and we found no difference in blood pressure, quantity of bleeding or pulmonary capillary pressure, considering the reinterventional moment in comparison to the values taken immediately after the initial surgery and the ones registered during the surgical reintervention. There was significative increase in the central venous pressure value, decreased urine output and drop in the cardiac index. Based on this observation, we believe it is possible to have a presumptive diagnosis of partial pericardial tamponade by bidimensional echocardiographic studies just before the surgical reintervention.

[Doppler color transesophageal echocardiography. Report of the first 110 studies carried out at the Ignacio Chávez National Institute of Cardiology]

Transesophageal echocardiography allows views of the posterior structures of the heart. This approach provides additional and complementary information to the transthoracic study, it is also an alternative in those patients with technical limitations for optimal precordial imaging. This study analysis the first 110 cases studied with transesophageal echocardiography in the National Institute of Cardiology Ignacio Chávez. They correspond to patients with valvular heart disease, prosthesis, acute and chronic ischemic heart disease, dissecting aortic aneurysm, cardiomyopathies, thrombus, tumors and masses. As well as paediatric and adult with complex congenital heart disease. The advantages of the transesophageal technique compared with the precordial approach are described.

[Transesophageal echocardiography. General principles and applications]

A new echocardiographic technique is described, which allows cardiovascular ultrasonic exploration by means of a transducer mounted on the distal tip of a gastroscope. The transducer is moved along the esophagus and from time to time into the stomach, which permits real-time visualization of the different cardiac segments and the great arteries. This technique is of special utility in the exploration of posterior structures as are the left atrium and its appendage, the pulmonary veins, etc. The most important views in the transverse plane are described, as well as the technical aspects, the limitations and the possible complications.