Clinical characteristics of vulnerable populations hospitalized and diagnosed with COVID-19 in Buenos Aires, Argentina.

There is not in Argentina publications regarding the presentation of patients with COVID-19 requiring hospitalized and emergency care in vulnerable populations (lower incomes and less education tend at greater risk for poor health status and healthcare access), and it has few reports in developing countries. The objective is to determine whether in the care of vulnerable patients, to succeed against COVID-19, multiple public health tools and interventions will be needed to minimize morbidity and mortality. The study is a prospective cohort investigation of patients with lab-confirmed COVID-19, who required to any of the Health Centers response from April 8, 2020, to August 18, 2020. In Buenos Aires Metropolitan Area (AMBA), April 8, 2020 the virus was identified in patients hospitalized in the "Southeast Network" (SN), AMBA. SN covering an area of 661 square kilometers, with 1.8 million inhabitants residing in urban, and rural areas. A total of 14 health centers with different levels of care complexity provide care to patients in the region. The information of each patient with COVID-19 evaluated by SN, was incorporated in an Epidemiological Dashboard. The investigation was designed and reported with consideration of observational studies in epidemiology. We describe the hospitals presentation and care of persons who required SN response and were ultimately diagnosed with COVID-19. From April 8, 2020, to August 18, 2020, were included 1495 patients with lab-confirmed COVID-19 in SN. A total of 58% patients were men, and the mean age (SD) was 48.9 (15.59) years. Eighty one percent patients with pre-existing diseases, most frequent hypertension and diabetes, but hypertension, chronic lung disease, and cardiovascular disease presented higher risk. A total of 13% were hospitalized in Intensive Therapy Unit. The mortality of the cohort was 9.77%. Mortality was higher for patients aged 65 or more (OR 5.09), and for those had some pre-existing disease (OR 2.61). Our observations are consistent with reports demonstrating older persons, and those with comorbidities have the highest risk of mortality related to COVID-19. However, unlike other reports from developed or some developing countries, the mortality in our study is lower. This finding may be related to age of our cohort is younger than other published. Also, the health system was able to respond to the demand.

Liposome-encapsulated antigens induce a protective CTL response against Listeria monocytogenes independent of CD4+ T cell help.

Protection against intracellular pathogens is usually mediated by cytotoxic T lymphocytes (CTL). Induction of a protective CTL response for vaccination purposes has proven difficult because of the limited access of protein antigens or attenuated pathogens to the MHC class I presentation pathway. We show here that pH-sensitive PE/CHEMS liposomes can be used as a vehicle to efficiently deliver intact proteins for presentation by MHC class I. Mice immunized with listerial proteins encapsulated in such liposomes launched a strong CTL response and were protected against a subsequent challenge with L. monocytogenes. Remarkably, the CTL response was induced independently of detectable CD4(+) T cell help.

The action of red wine and purple grape juice on vascular reactivity is independent of plasma lipids in hypercholesterolemic patients.

Although red wine (RW) reduces cardiovascular risk, the mechanisms underlying the effect have not been identified. Correction of endothelial dysfunction by RW flavonoids could be one mechanism. We measured brachial artery reactivity by high-resolution ultrasonography, plasma lipids, glucose, adhesion molecules (ICAM-1 and VCAM), and platelet function in 16 hypercholesterolemic individuals (8 men and 8 women; mean age 51.6 +/- 8.1 years) without other risk factors. Twenty-four normal subjects were used as controls for vascular reactivity. Subjects randomly received RW, 250 ml/day, or purple grape juice (GJ), 500 ml/day, for 14 days with an equal wash-out period. At baseline, all 16 subjects were hypercholesterolemic (mean LDL = 181.0 +/- 28.7 mg/dl) but HDL, triglycerides, glucose, adhesion molecules, and platelet function were within normal limits. Brachial artery flow-mediated dilation was significantly decreased compared to controls (9.0 +/- 7.1 vs 12.1 +/- 4.5%; P < 0.05) and increased with both GJ (10.1 +/- 7.1 before vs 16.9 +/- 6.7% after: P < 0.05) and RW (10.1 +/- 6.4 before vs 15.6 +/- 4.6% after; P < 0.05). RW, but not GJ, also significantly increased endothelium-independent vasodilation (17.0 +/- 8.6 before vs 23.0 +/- 12.0% after; P < 0.01). GJ reduced ICAM-1 but not VCAM and RW had no effect on either molecule. No significant alterations were observed in plasma lipids, glucose or platelet aggregability with RW or GJ. Both RW and GJ similarly improved flow-mediated dilation, but RW also enhanced endothelium-independent vasodilation in hypercholesterolemic patients despite the increased plasma cholesterol. Thus, we conclude that GJ may protect against coronary artery disease without the additional negative effects of alcohol despite the gender.

Reelin influences the expression and function of dopamine D2 and serotonin 5-HT2A receptors: a comparative study.

Reelin is an extracellular matrix protein that plays a critical role in neuronal guidance during brain neurodevelopment and in synaptic plasticity in adults and has been associated with schizophrenia. Reelin mRNA and protein levels are reduced in various structures of post-mortem schizophrenic brains, in a similar way to those found in heterozygous reeler mice (HRM). Reelin is involved in protein expression in dendritic spines that are the major location where synaptic connections are established. Thus, we hypothesized that a genetic deficit in reelin would affect the expression and function of dopamine D2 and serotonin 5-HT2A receptors that are associated with the action of current antipsychotic drugs. In this study, D2 and 5-HT2A receptor expression and function were quantitated by using radioligand binding studies in the frontal cortex and striatum of HRM and wild-type mice (WTM). We observed increased expression (p<0.05) in striatum membranes and decreased expression (p<0.05) in frontal cortex membranes for both dopamine D2 and serotonin 5-HT2A receptors from HRM compared to WTM. Our results show parallel alterations of D2 and 5-HT2A receptors that are compatible with a possible hetero-oligomeric nature of these receptors. These changes are similar to changes described in schizophrenic patients and provide further support for the suitability of using HRM as a model for studying this disease and the effects of antipsychotic drugs.

Carotid arterial compliance in patients with congestive heart failure secondary to idiopathic dilated cardiomyopathy.

Conduit artery distensibility affects the pulsatile component of afterload and may contribute to impaired left ventricular function in patients with congestive heart failure (CHF). The objectives of this study were to (1) determine whether arterial distensibility is reduced in patients with CHF, and (2) determine whether decreased arterial compliance is related to an abnormality in vascular wall structure (i.e., wall thickness or excessive levels of circulating neurohumoral vasoconstrictors, or both). The study participants included 40 patients with CHF secondary to idiopathic dilated cardiomyopathy and 33 age-matched healthy volunteers. High-resolution ultrasonography was performed to directly visualize the common carotid artery and measure its diameter and wall thickness. Its elastic properties were determined by relating changes in arterial diameter to changes in pressure generated with each heart beat. Carotid artery distensibility was less (14.1 +/- 1.1 vs 25.3 +/- 1.6 10(-6).N-1.m2, p < 0.001) and Young's modulus of elasticity was greater (3.99 +/- 0.51 vs 2.29 +/- 0.23 10(5).N.m-2, p < 0.005) in patients with CHF than in normal subjects. Also, carotid artery wall thickness was increased in patients with CHF. When the entire population was considered, age, wall thickness, and plasma norepinephrine and aldosterone concentrations correlated inversely with distensibility, whereas age and plasma norepinephrine concentration correlated directly with elasticity. Among normal subjects, only age correlated inversely with distensibility; among patients with CHF, only plasma norepinephrine concentration correlated with elasticity. It is concluded that carotid artery distensibility is reduced in patients with CHF.(ABSTRACT TRUNCATED AT 250 WORDS)

Oral delivery of DNA vaccines using attenuated Salmonella typhimurium as carrier.

The efficacious delivery of eukaryotic expression plasmids to inductive cells of the immune system constitutes a key prerequisite for the generation of effective DNA vaccines. Here, we have explored the use of bacteria as vehicles to orally deliver expression plasmids. Attenuated Salmonella typhimurium aroA harbouring eukaryotic expression plasmids that encoded virulence factors of Listeria monocytogenes were administered orally to BALB/c mice. Strong cytotoxic and helper T cell responses as well as antibody production were elicited even after a single administration. Mice immunised four times with Salmonella that carried a eukaryotic expression plasmid encoding the secretory listerial protein listeriolysin were protected against a subsequent lethal challenge with this pathogen. A single dose was already partially protective. The efficiency of this vaccination procedure was due to transfer of the expression plasmid from the bacterial carrier to the mammalian host. Evidence for such an event could be obtained in vivo and in vitro. Expression of the desired antigen in various lymphoid tissues was already detectable 1 day after administration of the DNA vaccine and persisted for at least 1 month in spleen and mesenteric lymph nodes. Induction of cytotoxic and helper T cell responses was observed in all mouse strains tested including outbred strains whereas antibodies were mainly detected in BALB/c. Furthermore, we could show that immunogenicity could be improved by increasing the invasiveness of the bacterial carrier.

Lactic acid concentration and acid-base balance in cerebrospinal fluid: observations of diagnostic importance in non-Hodgkin lymphoma.

Measurements of lactic acid concentration and gas analysis were performed in lumbar cerebrospinal fluid from 36 patients without malignant central nervous system involvement and four patients with meningeal dissemination of non-Hodgkin lymphoma. The upper lactic acid concentration in controls of 2.48 mmol/l was exceeded in all four patients, also in cases with low blast counts and normal protein and glucose content. The pH, pCO2, pO2 and standard bicarbonate concentration in spinal fluid of patients with meningeal dissemination in non-Hodgkin lymphoma did not show significant differences compared with other patients and controls. Determination of the lactic acid concentration in cerebrospinal fluid add information, relevant to the diagnosis of meningeal involvement in non-Hodgkin lymphoma.

Acute myocardial infarction after simultaneous thrombosis in normal right and left coronary arteries.

A 32-year-old male patient with clinical and electrocardiographic evidence of acute myocardial infarction underwent coronary angiographic study. We observed nonocclusive thrombosis simultaneously in right and left anterior descending coronary arteries, without confirmation of spasm or obstructive artery disease in other coronary branches. Documentation of coronary thrombosis in more than one artery is rare, and its pathophysiology is still unknown. With the advent of thrombolytic therapy and immediate coronary angiographic studies in patients with evolving myocardial infarction, it has been possible to confirm the presence of thrombus and the type of coronary disease. In this case, we observed total lysis of both thrombi and the final aspect of "normal" angiographically reperfused coronary arteries.

Difference between the response of the pulmonary and systemic circulation during exercise in congestive heart failure.

Thirty nine patients with cardiomyopathy were evaluated by a hemodynamic study at rest and during isotonic exercise. These patients were divided into two groups on the basis of their left ventricular ejection fraction (LVEF): A, control group (LVEF greater than 40%, N = 19); B, severe congestive heart failure group (LVEF less than or equal to 40%, N = 20). Patients in group A showed adequate cardiovascular responses to exercise, i.e. increased cardiac index (80%) and stroke volume index (17%), decreased systemic vascular resistance (36.8%) but no significant change in pulmonary arteriolar resistance values. In contrast, patients in group B showed a slight and heart rate-dependent increase in cardiac index (38.5%), no improvement of stroke volume index (-3.4%), decreased systemic vascular resistance (21.6%) and increased pulmonary arteriolar resistance (41.2%) with exercise. This group also showed a significant increase in right atrial pressure that might reflect a decrease in right ventricular performance secondary to an abnormal pulmonary vascular response during exercise.

[Intensive Care Unit stay. Variables that affect emotional reactions]. / Internação em UTI. Variáveis que interferem na resposta emocional.

PURPOSE: To evaluate the anxiety and depression levels during five days of stay in a Clinical Cardiological Intensive Care Unit (ICU) and verify the relation to different variables. METHODS: Forty seven patients were submitted to IDATE scale for anxiety and an avaliation for depression. The scores were compared to medical diagnoses, age, local of stay before the ICU, number of hospitalizations. RESULTS: Anxiety and depression scores decrease significant from first to fifth day of ICU stay. No significant correlation was found between age, number of hospitalizations, medical diagnoses and the anxiety and depression scores. Patients admitted from the emergency unit presented a correlation between anxiety and depression scores. CONCLUSION: Anxiety and depression decrease during the five days of ICU stay. Emotional reactions are not influenced by medical diagnoses, age and number of hospitalizations. The emergency unit stay affects emotionally the patient in the first days of ICU admission.

[Acute liver failure secondary to cardiogenic shock in patients with congestive heart failure]. / Falência hepática aguda secundária a choque cardiogênico em portadores de insuficiência cardíaca congestiva.

Fulminant hepatic failure is a complication of severe cardiocirculatory failure, with high morbidity and mortality, and is frequently misdiagnosed as fulminant viral hepatitis. We report three cases of patients with chronic severe heart failure who developed cardiogenic shock complicated by elevation of aminotransferase levels above 1,000 soon after the most severe episode of hypotension. All the three patients presented regression of hepatic enzymes 72h after admission. Two patients developed hepatic encephalopathy and renal failure. One underwent the implantation of an artificial left ventricle, followed by orthotopic heart transplantation. One died of systemic multiple organ failure, after he had showed improvement on his hepatic profile, and one was sent to the ward, after 15 days with marked improvement on his clinical status and no signs of hepatic disease.

[Thiocyanate toxicity arising from prolonged use of sodium nitroprusside in severe heart failure]. / Toxicidade pelo tiocianato decorrente do uso prolongado de nitroprussiato de sódio na insuficiência cardíaca grave.

PURPOSE: To evaluate the toxicity of thiocyanate induced by the infusion of sodium nitroprusside in patients with severe congestive failure. METHODS: We studied 23 patients with congestive heart failure, in class IV (NYHA) under continuous infusion of sodium nitroprusside with doses varying between 0.5 and 5.5 micrograms/kg/min. Clinical evaluation, thiocyanate serum dosage and laboratorial evaluation of renal, hepatic and pulmonary functions were done. RESULTS: Seventeen patients (74%) presented toxic levels of thiocyanate (over 10 micrograms/ml), with the average of 29.9 +/- 4.4 micrograms/ml. Only renal function was related to the presence of intoxication. Clinical evaluation was not accurate to diagnose the thiocyanate toxicity in the patients. CONCLUSION: Sodium nitroprusside is potentially toxic, especially when the renal function is abnormal. Thiocyanate dosage is useful in diagnosing nitroprusside induced toxicity and then it contributes to an adequate treatment and prevention of clinical toxicity.

Arterial distensibility as a possible compensatory mechanism in chronic aortic insufficiency.

OBJECTIVE: To evaluate elastic properties of conduit arteries in asymptomatic patients who have severe chronic aortic regurgitation. METHODS: Twelve healthy volunteers aged 30+/-1 years (control group) and 14 asymptomatic patients with severe aortic regurgitation aged 29+/-2 years and left ventricular ejection fraction of 0.61+/-0.02 (radioisotope ventriculography) were studied. High-resolution ultrasonography was performed to measure the systolic and diastolic diameters of the common carotid artery. Simultaneous measurement of blood pressure enabled the calculation of arterial compliance and distensibility. RESULTS: No differences were observed between patients with aortic regurgitation and the control group concerning age, sex, body surface, and mean blood pressure. Pulse pressure was significantly higher in the aortic regurgitation group compared with that in the control group (78+/-3 versus 48+/-1mmHg, P<0.01). Arterial compliance and distensibility were significantly greater in the aortic regurgitation group compared with that in the control group (11.0+/-0.8 versus 8.1+/-0.7 10(-10) N-1 m4, P=0.01 e and 39.3+/-2.6 versus 31.1+/-2.0 10(-6) N-1 m2, P=0.02, respectively). CONCLUSION: Patients with chronic aortic regurgitation have increased arterial distensibility. Greater vascular compliance, to lessen the impact of systolic volume ejected into conduit arteries, represents a compensatory mechanism in left ventricular and arterial system coupling.

[Circulatory assist device in counterpulsation]. / Dispositivo de assistencia circulatoria em contrapulsacao.

PURPOSE: To test a circulatory assist device (CAD) developed in the University of São Paulo. Heart Institute, Bioengineering Division. It is a valveless chamber working through the counterpulsation principle, aiming at assistance to temporary the left ventricle. PATIENTS AND METHODS: The CAD consists of a rigid polycarbonate shell, which houses in its interior a polyurethane bag with a maximum volume of 110 cm3, driven alternately by pressure and vacuum from an external electropneumatic device synchronized with the ECG. The device worked for 300 hours in a test bench simulating the cardiovascular system in order to verify its resistance to wear and fatigue. The CAD was implanted near the aortic root of five dogs, in whom cardiac failure was induced through the use of propranolol and plasma expanders. The CAD was driven for five periods of 2 minutes separated by pauses of equal duration. The hemodynamic parameters were measured during the mentioned periods. RESULTS: "In vitro" testing resulted in no wear or fatigue. No leakage was observed. In the "in vivo" testing the averages obtained during the on and off periods of the device showed for the on periods; a) lowering of the systolic pressures of both the aorta (17.5%) and the left ventricle (LV) 15.1%), lowering of the final diastolic pressure of the LV (15.4%) and lowering of the diastolic pressure of the aorta (27.4%); b) increase in cardiac output (45.5%); c) increase of the endocardial viability ratio by 37.5%. CONCLUSION: The tested device represents a therapeutic option in cases of acute left ventricle failure, since with it an improved cardiac performance was measured and an increased coronary perfusion can be presumed.

[Hemodynamic variable analysis in patients with systemic arterial hypertension undergoing physical exercise]. / Análise das variáveis hemodinâmicas em pacientes com hipertensão arterial sistêmica submetidos ao exercício físico.

PURPOSE: To verify the exercise-induced hemodynamic changes in moderate hypertensive patients. METHODS: Twenty nine patients were studied and they were submitted to cycloergometer supine exercise (50w and 100w) during cardiac catheterization. The hemodynamic variables were measured: cardiac index (CI), stroke volume (SV), systemic arterial resistance (SAR), pulmonary arterial resistance (PAR), wedge pressure (WP), right atrial pressure (RA), systolic arterial pressure (SP), diastolic arterial pressure (DP), mean arterial pressure (MP) and heart rate (HR). To evaluate the cardiac function, the patients were divided in two groups: GI with CI > 2.5 ml/min/m2 and GII CI < 2.5 ml/min/m2. RESULTS: During exercise, patients from GI and GII were similar-according to MAP, RA, WP, and HR. On the other hand, GI and GII exhibited different (#) behavior regarding SV, PAR and SAR. During the three exercise conditions, rest (R), 50w and 100w it was observed: a) PAR-R = 50 = 100 (GI); b) MP, PAR, WP, SV, SAR-R #50 #100 (GI); c) HR, PAR and SAR-R #50 #100 (GII). There was no correlation between the cardiac function (CI, SV) and the circulatory adjustment (PAR and SAR) or the pressure curve (SP, DP, MP) and HR. CONCLUSION: The results suggest that the cardiac function of GI patients depends, mainly, on the inotropism, while in GII patients it depends on the decrease of the afterload (PAR and SAR). Those changes may appear even in the late exercise stage (100w), with a bias to attain the GI levels. Those observations suggest functional changes in vasomotor tone of GII patients.

[The effect of intravenous furosemide on the hemodynamic parameters and colloid osmotic pressure in patients with pulmonary edema]. / Efeito da furosemida endovenosa sobre os parâmetros hemodinãmicos e na pressão coloidosmótica em pacientes com congestão pulmonar.

PURPOSE: To evaluate the effects of intravenous furosemide over hemodynamics variables and colloid osmotic pressure in patients with pulmonary edema. METHODS: Eight patients with pulmonary edema, mean age of 58.3 +/- 7.5 years, 6 men, were evaluated. Hemodynamic monitoring was performed by Swan-Ganz catheter in pulmonary artery to obtain RAP and PAWP, in mmHg, and HR, in bpm. Cardiac output (CO) was obtained by thermodilution method. Cardiac index (CI) in L/min/m2, and systolic index, in ml, arose from variables above. Mean arterial pressure (MAP), in mmHg, was obtained through catheterization of radial artery. patients were treated with 20 mg of intravenous furosemide, and hemodynamic variables were measured before and after 5, 15, 30, 60 and 120 minutes. COP was measured in Weil oncometer (IL 196) at same intervals. RESULTS: A significant reduction of RAP (p = 0.002) and PAWP (p < 0.0001), HR (p = 0.02), COP (p < 0.0001) and gradient between PAWP-COP (p < 0.0001) were observed. RAP and PAWP reduction was greater in the first five minutes and, otherwise, COP reduction was gradual in 120 min. PAWP-COP gradient initially positive, stayed negative during all study. MAP, CI, SI and SVR did not show statistical differences. CONCLUSION: Furosemide administration reduced RAP, PAWP, HR, COP and PAWP-COP gradient, probably by a redistribution of fluid excess in the interstitial to intravascular space, through changes in driving fluid forces, with predominance in colloid osmotic pressure, which reverse fluid from intravascular to interstitial observed in pulmonary edema.

[Nuclear magnetic resonance imaging in the diagnosis of left ventricular pseudoaneurysm. An old problem, a new option]. / Ressonância nuclear magnética no diagnóstico de pseudoaneurisma de ventrículo esquerdo. Antigo problema, nova opção.

We describe the case of a 61 year-old female patient admitted to the hospital with acute lateral myocardial infarction, in pulmonary edema, who evolved to cardiogenic shock in the first hours. Transesophageal echodoppler-cardiogram and nuclear magnetic resonance imaging showed the diagnosis of a left ventricular pseudoaneurysm. Surgical repair was successfully undertaken.

[Clinical and Doppler echocardiographic follow-up of elderly patients subjected to aortic balloon valvuloplasty]. / Seguimento clínco e ecodopplercardiográfico de idosos submetidos a valvuloplastia aórtica por cateter-balão.

PURPOSE: To evaluate the evolution of patients with critical aortic stenosis (AS) submitted to balloon aortic valvuloplasty (BAV). PATIENTS AND METHODS: sixteen patients (mean age 74.0 +/- 5.1 years), 11 (68.7%) women. The study periods consisted during the 3 rd (post-1) and 15th month (post-2) after dilatation. RESULTS: The functional class of angina and dyspnea persisted in all patients during period post-1, in 75% of the patients, during period post-2 in relation to intra-hospital evaluation. However, in period post-1, 53% of the patients had significant reduction of aortic valve area, trend which remained in period post-2. Simultaneously, progressive (insignificant) elevation of the left ventricular aortic peak to peak gradient was noticed in the periods post-1 and post-2. Two deaths and two aortic valve replacements occurred during the study. CONCLUSION: BAV is associated to maintenance of functional class improvement obtained immediately after dilatation despite the aortic valve restenosis registered by echodopplercardiography.

[Mitral subvalvular aneurysm of the left ventricle]. / Aneurisma subvalvar mitral de ventrículo esquerdo.

A 21-year-old white man presented with cardiogenic shock and refractory pulmonary congestion. At the transthoracic echocardiogram a subvalvar left ventricular aneurysm of the inferior wall with severe mitral regurgitation was observed. The outcome was favorable after surgical correction of the mitral regurgitation and of the subvalvar aneurysm. We emphasize that, whenever possible, valvar repair is better than mitral replacement, since annulus tissue fragility causes suturing of the mitral prosthesis to be difficult.