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Antonio Alvarez

Publications and source records attributed to Antonio Alvarez.

13 recordsLinked to original sources
PubMed2006

Validation of an algorithm based on direct examination of specimens in suspected ventilator-associated pneumonia.

BACKGROUND: The management of suspected ventilator-associated pneumonia (VAP) is traditionally based on either a clinical or a "bacteriological" approach. Direct examination of specimens may provide a valuable help to both approaches. OBJECTIVE: The objective was to test an algorithm for the management of suspected pneumonia based on severity criteria and Gram stains of specimens, including early treatment of patients with a positive Gram stain of a protected telescoping catheter specimen and awaiting culture results in patients with either Gram stains of endotracheal aspirate and protected specimen both being negative, or only positive endotracheal aspirate (EA), except in the presence of the severity criteria. METHODS: Observational study including 76 first episodes of suspected pneumonia in 4 units. We assessed the rates of correctly diagnosed episodes and of those treated empirically (i.e., ultimately confirmed pneumonia), or appropriately not receiving such therapy (non-confirmed pneumonia), based on protected specimen culture results. RESULTS: When adhered to, the algorithm allowed early appropriate management in 80% of patients, including 83% of those with confirmed pneumonia, and 74% of those without confirmed infection. The rate of appropriately managed episodes using this algorithm was significantly higher than that using a strategy based on the modified clinical pulmonary infection score (CPIS) alone (80 vs. 50%, p<0.001). The empiric regimen was adequate in 86% of confirmed episodes. CONCLUSION: A strategy based on severity criteria and Gram stain examination of respiratory tract specimens allows correct identification and appropriate management of more than 80% of mechanically ventilated patients who need or do not need therapy for suspected pneumonia.

Adult↗
PubMed2006

Software tools for interactive instruction in radiologic anatomy.

RATIONALE AND OBJECTIVES: To promote active learning in an introductory Radiologic Anatomy course through the use of computer-based exercises. MATERIALS AND METHODS: DICOM datasets from our hospital PACS system were transferred to a networked cluster of desktop computers in a medical school classroom. Medical students in the Radiologic Anatomy course were divided into four small groups and assigned to work on a clinical case for 45 minutes. The groups used iPACS viewer software, a free DICOM viewer, to view images and annotate anatomic structures. The classroom instructor monitored and displayed each group's work sequentially on the master screen by running SynchronEyes, a software tool for controlling PC desktops remotely. RESULTS: Students were able to execute the assigned tasks using the iPACS software with minimal oversight or instruction. Course instructors displayed each group's work on the main display screen of the classroom as the students presented the rationale for their decisions. The interactive component of the course received high ratings from the students and overall course ratings were higher than in prior years when the course was given solely in lecture format. CONCLUSIONS: DICOM viewing software is an excellent tool for enabling students to learn radiologic anatomy from real-life clinical datasets. Interactive exercises performed in groups can be powerful tools for stimulating students to learn radiologic anatomy.

Anatomy↗
PubMed2006

Bovine babesiosis live vaccine production: use of gamma irradiation on the substrate.

Gamma irradiation on bovine serum and red blood cells (RBC) allows proliferation and growth of in vitro-cultured Babesia sp., and has potential application to inactivate contaminating viruses and bacteria from the substrate. Gamma irradiation with 25 kGy in a source of (60)Co was able to inactivate infectious bovine rinotracheitis (IBR) and bovine viral diarrhea (BVD) viruses in artificially contaminated serum; besides, bacteria were also eliminated. In vitro culture of Babesia bovis (B. bovis) in modified substrate, by adding irradiated serum with (60)Co at 25 kGy was propagated from 24-well culture plates to 225 cm(2) tissue culture flasks, and percentages of parasitized erythrocytes (PPE) from 2.4% to 8.8% were obtained. Infected RBC adapted to Irrad S were transferred to the irradiated substrate in vitro culture system, by using serum irradiated at 25 kGy and RBC from 10 to 70 Gy. The PPE ranged from 3.1 to 11. Culture of Babesia bigemina (B. bigemina) was established with Irrad S (25 kGy); its propagation was achieved in tissue culture flasks reaching PPE from 0.5 to 4.3 with no statistical difference (P > 0.05) when compared to the nonirradiated control culture (1.2-4.8). B. bigemina-infected RBCs were transferred to the modified culture system by adding irradiated serum and RBC (25 kGy and 70 Gy, respectively). PPE obtained in culture flasks were from 0.8 to 4.2. The results indicate that gamma irradiation is a suitable method to inactivate potential viral contamination and eliminate bacteria from bovine serum, to produce a live attenuated vaccine through the in vitro culture.

Animals↗
PubMed2005

A prospective controlled crossover trial of a new presentation (10% vs. 5%) of a heat-treated intravenous immunoglobulin.

Thirty-five patients with primary or secondary immunoglobulin deficiency were included in a crossover study to test the tolerance, clinical efficacy, and safety of a liquid pasteurized 10% concentrated intravenous gammaglobulin versus a 5% concentrated presentation. No statistically significant differences were found between these parameters. Total serum immunoglobulin-(Ig)G and IgG subclass levels were similar in both groups. No modifications in serum alanine transferase (ALT) levels and viral status (HBsAg, HCV-RNA, p24 antigen or RNA for HIV) were observed throughout treatment. Adverse reactions were reported in 3 out of 70 infusions (4.3%), 2 in the experimental group and 1 in the control group. The maximum recommended rate of infusion for the 10% gammaglobulin is the same as for the 5% gammaglobulin product (0.04 ml/kg/min); generally speaking, this means that infusion time is halved. We conclude that a 10% gammaglobulin product is a well-tolerated, clinically efficacious and safe intravenous preparation, and that it could be a short infusion time alternative for primary and secondary antibody deficiencies.

Adolescent↗
PubMed2005

Antibody production deficiency with normal IgG levels in bronchiectasis of unknown etiology.

BACKGROUND: No defined cause of bronchiectasis is currently found in approximately 50% of cases. Bronchiectasis is a common long-term complication in patients with primary hypogammaglobulinemia. STUDY OBJECTIVES: To ascertain whether antibody production deficiency with normal total serum IgG levels is associated with bronchiectasis. DESIGN: Antibody response to a pneumococcal unconjugate vaccine and an Haemophilus influenzae type b conjugate vaccine was prospectively studied in all consecutive adult patients with bronchiectasis of unknown etiology who were assessed in our chest outpatient clinic from January 1994 to October 2001. Serum-specific antibodies were measured by enzyme-linked immunosorbent assay, and the results were compared with those obtained in a healthy adult control group. Antibody production deficiency was defined as a failure to respond to either vaccine. RESULTS: One hundred seven patients were included in the study (mean age, 46.3 years). Antibody production deficiency was diagnosed in 12 patients (11%). A significantly higher incidence of otitis media, lower serum IgG2 subclass levels, and lower preimmunization antibody levels to Streptococcus pneumoniae and H influenzae type b were observed in patients with antibody production deficiency. The probability of antibody production deficiency in patients with a history of otitis media was 20%, 26% in those with low IgG2 subclass levels, and 58% in those with both a history of otitis media and low IgG2 subclass levels. CONCLUSIONS: Antibody production deficiency with normal IgG levels may be associated with bronchiectasis, making it advisable to evaluate the antibody response to both the H influenzae and pneumococcal vaccines in patients with bronchiectasis of unknown etiology, particularly in those with a history of otitis media, low IgG2 subclass levels, and low levels of baseline specific antibodies.

Adolescent↗
PubMed2005

Modulating effects of intravenous immunoglobulins on serum cytokine levels in patients with primary hypogammaglobulinemia.

BACKGROUND: Intravenous immunoglobulins (IVIG) have usually been administered for replacement therapy of humoral immunodeficiencies, but their use in treating other disorders with an immune pathogenesis is increasing. The exact mechanism of action by which IVIG are of benefit in such diseases is complex and only partly understood. One of the proposed mechanisms of action is the modulation of cytokine release. METHODS: We selected 29 patients with primary hypogammaglobulinemia (common variable immunodeficiency), receiving long-term substitutive therapy with IVIG, and 14 healthy blood donors as a control group. Blood samples were then taken before and 1 hour after finishing the IVIG infusion. Only one blood sample was obtained from the healthy controls. The cytokines studied were interleukin (IL)-1 beta, IL-1 receptor antagonist (IL-1Ra), IL-2, IL-6, IL-8, tumor necrosis factor (TNF)-alpha, and interferon (IFN)-gamma. RESULTS: Patients with primary hypogammaglobulinemia showed significantly higher serum levels of IL-6, IL-8, IL-1Ra, and TNF alpha than healthy controls. IVIG infusion significantly increased serum concentration levels of IL-6, IL-8, IL-1Ra, and TNF alpha. No significant variation was observed in serum levels of IL-beta, IFN gamma, or IL-2 after IVIG infusion. Age, IVIG commercial preparation, and IVIG dose did not influence cytokine serum levels. Moreover, a significant correlation was observed between serum level variations of IL-1Ra and TNF alpha, as well as an associative trend between maximum changes in IL-6 and IL-8 concentrations. CONCLUSIONS: IVIG administration significantly alters the serum pattern of selected cytokines, which might explain, at least in part, the mechanism of action of IVIG in autoimmune or inflammatory disorders.

Adult↗
PubMed2004

Immunoglobulin therapy to control lung damage in patients with common variable immunodeficiency.

BACKGROUND: Lung damage progression is the most frequent condition in patients with common variable immunodeficiency (CVID). Appropriate immunoglobulin dose adjustments and follow-up guidelines to evaluate this have not been well established. OBJECTIVE: To assess the evolution of lung damage once stable residual serum levels of IgG over 600 mg/dl had been achieved. METHODS: A prospective study was conducted in 24 adult patients consecutively diagnosed with CVID, with no previous intravenous immunoglobulin (IVIG) treatment. IVIG dose, total serum IgG level, bacterial infection rate, pulmonary function tests (PFTs) and high resolution computed tomography (HRCT) of the thorax were monitored over 2 years. Moreover, outcome data were determined by measurement of chronic pulmonary disease (CPD). RESULTS: IVIG dose variability (205-372 mg/kg/21 days) to obtain the required serum IgG levels was determined. Patients with CPD needed higher doses than those without CPD (p=0.045). A significant reduction in severe and mild infections/patient-year was observed during treatment. Overall, there were no changes in PFTs and HRCT scores in patients without CPD, but both improved in patients with CPD. An increase of over 15% in overall HRCT score was detected in two patients without evidence of impairment in either clinical status or PFT values. CONCLUSIONS: Residual levels of total IgG over 600 mg/dl may help prevent progression of lung damage in patients with CVID. Levels of IgG, clinical manifestations and PFTs seem sufficient for routine follow-up. HRCT examination of the thorax, at least biennially, may help to identify patients in whom lung injury is progressing even though they may remain symptom-free and with stable PFTs.

Adult↗
PubMed2003

Use of endoscopic fibrinogen-thrombin in the treatment of severe hemoptysis.

Bronchial artery embolization (BAE) is the treatment of choice in the majority of patients with severe hemoptysis. However, this procedure may be unavailable and even fail or be counterindicated in 4-13% of cases. In these cases, the efficacy of fibrinogen-thrombin (FT) instilled endoscopically as treatment for massive hemoptysis was assessed. Between August 1993 and February 1996 a prospective clinical study was performed. FT instillation was indicated in all patients with severe hemoptysis (> 150 ml/12 h) in whom BAE had failed, was counterindicated or not available. FT was instilled endoscopically. Patients were followed up until June 2001. Eleven of 101 patients (11%) with hemoptysis > 150 ml/12 h in whom BAE was not possible or proved ineffective were included. The severe hemoptysis was controlled immediately in all cases. During the follow-up period (mean: 39.4 months), early relapse of the severe hemoptysis occurred in two patients (18%) and a long-time relapse in one. Mean procedure duration was 3 min and no attributable complications were observed in any case. In conclusion, these results suggest that topical treatment with FT could be considered in the initial endoscopic evaluation of patients with severe hemoptysis while awaiting BAE or surgery, or as alternative treatment to arterial embolization when the latter is not available, has proved ineffective or is counterindicated.

Adult↗
PubMed2003

Predicting pulmonary complications after pneumonectomy for lung cancer.

OBJECTIVES: Patients undergoing pneumonectomy for lung cancer are thought to be at high risk for the development of postoperative pulmonary complications (PC) and these complications are associated with high mortality rates. The purpose of this study was to identify independent factors associated with increased risk for the development of postoperative PC after pneumonectomy for lung cancer, and to assess the usefulness of predicted pulmonary function to identify high risk patients and other adverse outcomes. PATIENTS AND METHODS: We reviewed retrospectively 242 patients undergoing pneumonectomy for lung cancer during a 12-year period. Perioperative data (clinical, pulmonary function test, and surgical) were recorded to identify risk factors of PC by univariate and multivariate analyses. RESULTS: Overall mortality and morbidity rates were 5.4 and 59%, respectively. Thirty-four patients (14%) developed PC (acute respiratory failure, ARF = 8.7%, reintubation = 5.4%, pneumonia = 3.3%, atelectasis = 2.9%, postpneumonectomy pulmonary edema = 2.5%, mechanical ventilation more than 24 h = 1.2%, pneumothorax = 0.8%). Patients with surgical (P < 0.001), cardiac (P < 0.001) and other complications (P < 0.01) had higher incidence of PC than those without postoperative complications. Intensive care unit stay (53 +/- 39 h vs. 35 +/- 19 h; P < 0.001) and hospital stay (18 +/- 11 days vs. 12 +/- 7 days; P < 0.001) was significantly longer in patients with PC. The mortality rate associated with PC was 35.5% (P < 0.001). By univariate analysis, it was found that older patients (P = 0.007), chronic obstructive pulmonary disease (COPD) (P = 0.023), heart disease (P = 0.019), no previous record of chest physiotherapy (P = 0.008), poor predicted postoperative forced expiratory volume in 1s (ppo-FEV1) (P = 0.001), and prolonged anesthetic time (P < 0.001) were related with higher risk of PC. In the multiple logistic regression model, the anesthetic time (minutes; odds ratio, OR = 1.012), ppo-FEV1 (ml/s; OR = 0.998), heart disease (OR = 2.703), no previous record of previous chest physiotherapy (OR = 2.639), and COPD (OR = 2.277) were independent risk factors of PC. CONCLUSIONS: PC after pneumonectomy are associated with high mortality rates. Careful attention must be paid to patients with COPD and heart disease. Our results confirm the relevance of previous chest physiotherapy and the importance of the length of the surgical procedure to minimize the incidence of PC. The predicted pulmonary function (ppo-FEV1) may be useful to identify high risk patients for PC development and adverse outcomes.

Adult↗
PubMed2003

Hemimegalencephaly: part 2. Neuropathology suggests a disorder of cellular lineage.

Cerebral tissue from hemispherectomy in three children (two 4-month-old girls and one 4-year-old boy) with hemimegalencephaly was studied using histochemical and immunocytochemical markers of neuronal and glial maturation and identity. Histologic abnormalities of cellular growth and cytomorphology, including "balloon cells," were present in both gray and white matter, in addition to disorganized tissue architecture. Cells in the mitotic cycle were absent. Many hypertrophic, atypical cells with enlarged processes exhibited mixed or ambiguous lineage, with immunoreactivity for both glial (glial fibrillary acidic protein [GFAP]; S-100beta) and neuronal proteins (microtubule-associated protein 2 [MAP2], neuronal nuclear antigen, chromogranin A, and neurofilament protein [NFP]). Strong vimentin reactivity was present in neurons, as well as glial cells and cells of mixed lineage, suggesting incomplete maturation. Synaptophysin-reactive axons terminated on a minority of balloon cells and on most heterotopic single neurons in white matter, confirmed by electron microscopy, demonstrating that single heterotopic neurons are not synaptically "isolated," as they may appear; thus, they are capable of contributing to epilepsy. Oligodendrocytes are the least affected cells, at least in some cases. The findings are reminiscent of the hamartomas of tuberous sclerosis. We conclude that hemimegalencephaly is a primary disorder of neuroepithelial lineage and cellular growth. A migratory disturbance contributes to disorderly tissue architecture but is secondary. No pathologic difference is detected between isolated and syndromic forms of hemimegalencephaly.

Biomarkers↗
PubMed2002

[Cystic fibrosis in adults: study of 111 patients].

BACKGROUND: Our goal was to establish the clinical and genetic characteristics of patients diagnosed with adult-onset cystic fibrosis (CF). PATIENTS AND METHOD: This was a retrospective observational descriptive comparative study of CF patients according to their age at the time of diagnosis. All adult patients (> 16 years old) attended in our CF Unit until November 2001 were included in the study. Those patients diagnosed of CF at their childhood (< 16 years old) were categorized as Group A patients, and those diagnosed in adulthood (>= 16 years old) were categorized as group B patients. Anthropometric parameters, respiratory and digestive clinical abnormalities, chest and abdominal radiological exams, sputum bacteriology, respiratory function and genetic tests were evaluated. Statistical analysis between groups was performed by comparing chi square test for qualitative values and the Student t test for quantitative values. RESULTS: One hundred and eleven patients (60 women, mean age 28, range 16-69 years) out of a total sample of 245 (45.3%) patients attended at the CF unit were enrolled in the study. Group A included 61 patients (32 women; mean age 23) and group B included 50 patients (28 women; mean age 32). The comparative study between both groups showed that patients in group B were older, had a higher weight and less incidence of initial digestive abnormalities, pancreatic insufficiency, malnutrition, hepatic disease, chronic bronchial colonization by Pseudomonas aeruginosa, admissions, lung transplantation and deaths due to CF. On the contrary, these patients had a higher incidence of pancreatitis, allergic bronchopulmonary aspergillosis at diagnosis and better respiratory function test parameters. The sweat test was negative in 4 patients of group B and 1 of group A. The genetic study showed 31 different CF mutations, from which only 10 were observed in group B. CONCLUSIONS: CF can also be diagnosed in adult age. Patients diagnosed in adulthood have less digestive abnormalities, better lung function and different genetic mutations. The sweat test can be negative or undetermined. These patients also display a better prognosis.

Adolescent↗
PubMedDate not supplied

Gas chromatographic-mass spectrometry study of the essential oils of Pimenta racemosa var. terebinthina and P. racemosa var grisea.

The essential oil of the leaves of P. racemosa var. terebinthina and P. racemosa var. grisea were examined by GC and GC/MS. The major constituents were alpha-terpineol acetate (27%), alpha-terpineol (20%) and 4-methoxy eugenol (12.6%) for Pracemosa var. terebinthina and 4-methoxy-isoeugenol (75.2%) and 4-methoxy-eugenol (4.5%) for P. racemosa var. grisea.

Aldehydes↗