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Biomedical subjects

A Barrera

Publications and source records attributed to A Barrera.

At least 19 recordsLinked to original sources
PubMed2002

Lower cortisol levels in depressed patients with comorbid post-traumatic stress disorder.

Post-traumatic stress disorder (PTSD) is often comorbid with major depressive episodes (MDEs) and both conditions carry a higher rate of suicidal behavior. Hypothalamic-pituitary-adrenal (HPA) axis and serotonin abnormalities are associated with both conditions and suicidal behavior, but their inter-relation is not known. We determined cortisol response to placebo or fenfluramine in MDE, MDE and PTSD (MDE+PTSD), and healthy volunteers (HVs) and examined the relation of cortisol responses to suicidal behavior. A total of 58 medication-free patients with MDE (13 had MDE+PTSD) and 24 HVs were studied. They received placebo on the first day and fenfluramine on the second day. Cortisol levels were drawn before challenge and for 5 h thereafter. The MDE+PTSD group had the lowest plasma cortisol, the MDE group had the highest, and HVs had intermediate levels. There were no group differences in cortisol response to fenfluramine. Suicidal behavior, sex, and childhood history of abuse were not predictors of baseline or postchallenge plasma cortisol. Cortisol levels increased with age. This study finds elevated cortisol levels in MDE and is the first report of lower cortisol levels in MDE+PTSD. The findings underscore the impact of comorbidity of PTSD with MDE and highlight the importance of considering comorbidity in psychobiology.

Adult↗
PubMed2002

Usefulness of sputum culture for diagnosis of bacterial pneumonia in HIV-infected patients.

The use of sputum culture in immunocompetent patients with community-acquired pneumonia is controversial. The usefulness of this technique in HIV-infected patients has not been evaluated. A prospective, observational, multicenter, hospital-based study of bacterial community-acquired pneumonia was carried out to analyze the value of sputum culture in HIV-infected patients. Only good-quality sputum samples were cultured. Altogether, 355 cases of bacterial community-acquired pneumonia were included. An etiological diagnosis was obtained in 190 (53.5%) cases. Sputum was cultured in 313 (88.1%) cases, being diagnostic in 108 (34.5%). The microorganism identified in sputum culture was the same as that identified in sterile samples in 26 of 27 (96.3%) cases in which both cultures were diagnostic. The microbiologic findings in sputum and bronchoscopic cultures were concordant in seven of eight (87.5%) cases in which both were positive. These results suggest that sputum culture is a useful technique, given its availability and ease of performance and its good correlation with culture of sterile samples.

AIDS-Related Opportunistic Infections↗
PubMed2002

[Nocardiosis in patients with HIV infection].

OBJECTIVE: To know the characteristics of nocardiosis in HIV infected patients. PATIENTS AND METHODS: Retrospective analysis of HIV infected patients with a concomitant Nocardia spp. infection in nine Andalusian hospitals. RESULTS: Eighteen cases of nocardiosis were studied. Seventeen patients were males and the mean age was 33.1 years. The risk behaviour for acquiring HIV infection was parenteral drug use in 15 patients (83.3%) and seven of them were active users when acquiring nocardiosis. The mean CD4 lymphocyte count was 66.3 106/l. The nocardiosis was manifested as disseminated disease in eight patients, only pulmonary disease in four cases, lymphocutaneous or soft-tissue nocardiosis in five, and pericarditis in the remaining patient. In the ten cases with pulmonary involvement, the chest X-ray revealed an alveolar, interstitial, and mixed pattern in five, three, and two patients, respectively. Most patients were treated with cotrimoxazole, with good clinical and microbiological responses in 88.8% of them. Some surgical procedures were required in six patients. Eight patients died, three on account of nocardiosis and five on account of other causes. There were three relapses. CONCLUSIONS: Nocardia spp. infection is rare among patients with AIDS and occurs in immunosuppressed patients and drug users. The pulmonary, cutaneous, and soft-tissue were the most commonly observed forms in our series. Despite the high frequency of disseminated infection, the response to th

Adult↗
PubMed2001

Does angina the week before protect against first myocardial infarction in elderly patients?

Mortality rates for coronary artery disease are greater in elderly patients. Although prodromal angina occurring shortly before an acute myocardial infarction (MI) has protective effects against ischemia, this effect has not been well documented in older patients. This study investigated whether angina 1 week before a first MI provides protection in this group of patients. A total of 290 consecutive elderly (>64 years old, n = 143) and adult patients (<65 years old, n = 147) with a first MI were examined to assess the effect of preceding angina on the short- and long-term prognosis. Elderly patients with a history of prodromal angina were less likely than those without angina to experience in-hospital death, heart failure, or the combined end point of in-hospital death and heart failure (6% vs 20.4%, p = 0.02; 10% vs 23.7%, p = 0.07; 14% vs 32.3%, p = 0.01, respectively). Left ventricular function was more frequently depressed (ejection fraction <40%) in elderly patients without (44.8%) than with (26%, p = 0.04) preinfarction angina, and the incidence of arrhythmias (complete heart block and ventricular fibrillation) was greater in the former group (16.1% vs 4%, p = 0.03). Multivariate analysis confirmed that the presence of preinfarction angina was an independent predictor of in-hospital death and heart failure in older patients (odds ratio 0.28, p = 0.009). The occurrence of angina 1 week before a first MI may confer protection against in-hospital adverse outcomes, and may preserve left ventricular function in older patients.

Aged↗
PubMed2001

[The influence of angina the week before a first myocardial infarction on short and medium-term prognosis].

INTRODUCTION AND OBJECTIVES: The implications of early angina on the prognosis of myocardial infarction are controversial. The aim of this study was to assess the effect of angina one week before the first myocardial infarction on short and medium-term prognosis. PATIENTS AND METHOD: A total of 290 consecutive patients (107 with previous angina and 183 without it) with the first myocardial infarction were studied to determine the effect of preceding angina on short and medium-term prognosis. Further criteria for inclusion were no previous history of angina > 1 week before the first myocardial infarction, and no evidence of prior structural cardiopathy. The end points studied were death and congestive heart failure in the acute phase of myocardial infarction and during the follow-up. RESULTS: Patients with a history of prodromal angina were less likely to experience in-hospital death, heart failure or combined end-point (3.7 vs 11.5%; 4.6 vs 15.8%; 7.5 vs 21.3%) (p = 0.002). There was also a difference between groups in the follow-up (4.1 vs 13.2%; p = 0.03). Multivariate analysis confirmed that the presence of preinfarction angina was an independent predictor of death and heart failure in the acute phase of myocardial infarction as well as in the follow-up. CONCLUSIONS: The occurrence of angina one week before the first myocardial infarction protects against death and heart failure in the acute phase of myocardial infarction as well as in the medium follow-up.

Analysis of Variance↗
PubMed2001

[Prognostic factors in colorectal neoplasm. Multivariate analysis in 224 patients].

BACKGROUND: Staging of colorectal carcinoma has prognostic value and allows to take decisions about adjuvant therapy and follow up. Prognostic factors are not universally accepted and there are different staging classifications. AIM: To assess the prognostic value of clinical and pathological variables in 224 patients subjected to a curative resection of a colorectal carcinoma. PATIENTS AND METHODS: A retrospective analysis of 99 men and 125 women, aged 23 to 91 years old subjected to a curative resection of a colorectal carcinoma and followed up for a mean of 72 months. RESULTS: Global survival at 60 months was 72%. Univariate analysis showed that tumor localization, vascular permeation, wall infiltration and number of involved lymph nodes had an influence on survival. A Cox regression model disclosed tumor localization (colon versus rectum), a carcino-embryonic antigen over 30 ng/ml, vascular permeation, presence of 1 to 4 involved lymph nodes, or 5 or more lymph nodes and the presence of an apical lymph node as variables with significant prognostic value. CONCLUSIONS: Our series confirms the prognostic importance of lymph node involvement. This parameter is incorporated in Jass, GITSG (both modifications of Dukes classIfication) and TNM staging scores.

Adenocarcinoma↗
PubMed2000

Effect of methyl tertiary butyl ether concentrations on exhaust emissions from gasoline used in the metropolitan area of Mexico City.

In this work, the primary objective was to assess the impact of oxygenated fuel on the exhaust emissions from an important fraction of vehicles in the Metropolitan Area of Mexico City (MAMC). The results aim to provide information on the actual effect of MTBE on a fleet that represents more than 60% of the in-use vehicles in the MAMC. Ten vehicles were tested with a low-octane base gasoline, and 10 more with a regular-grade unleaded base gasoline. Three MTBE concentrations, 5, 10, and 15 vol %, were tested following the U.S. Federal Test Procedure (FTP). CO, total HC, and NOx from the exhaust gases were quantitatively evaluated and also characterized for FTP speciated organic emissions. From this data, the O3-forming potential of the fuels was calculated. Results show that for the fleet using low-octane gasoline, the addition of 10% MTBE substantially reduced CO emissions, but total HC concentration in the exhaust showed a modest decrease. For the regular gasoline, the 10% MTBE blend seemed to be the best choice, but there was not a significant decrease in emissions. The specific reactivity of each fuel, expressed in grams of O3 per gram of nonmethane organic gases, increased with MTBE concentration in both cases. This result is important to consider, especially for a region like Mexico City, which has high atmospheric O3 concentrations.

Air Pollutants↗
PubMed2000

Contribution of LPG-derived emissions to air pollution in the metropolitan area of Guadalajara City.

Measurements of hydrocarbon (HC) emissions generated by the use of liquefied petroleum gas (LPG) in the metropolitan area of Guadalajara City (MAG) are presented in this work. Based on measurements in the course of distribution, handling, and consumption, an estimated 4407 tons/yr are released into the atmosphere. The three most important contributors to LPG emissions were refilling of LPG-fueled vehicles and commercial and domestic consumption. The MAG shows a different contribution pattern of LPG emission sources compared with that of the metropolitan area of Mexico City (MAMC). These results show that each megacity has different sources of emissions, which provides more accurate strategies in the handling procedures for LPG to decrease the impact in O3 levels. This work represents the first evaluation performed in Guadalajara City, based on current measurements, of the LPG contribution to polluting emissions.

Air Pollution↗
PubMed2000

Haemophilus influenzae pneumonia in human immunodeficiency virus-infected patients. The Grupo Andaluz para el Estudio de las Enfermedades Infecciosas.

Although Haemophilus influenzae is a common etiologic agent of pneumonia in patients infected with human immunodeficiency virus (HIV), the characteristics of this pneumonia have not been adequately assessed. We have prospectively studied features of H. influenzae pneumonia in 26 consecutive HIV-infected inpatients. Most of these patients were severely immunosuppressed; 73.1% had a CD4+ cell count <100/microL. A subacute clinical presentation was observed in 27% of the patients and was associated with a higher degree of immunosuppression (P=.04). Bilateral lung infiltrates were noted radiographically in 57.7% of the cases. The mortality attributable to H. influenzae pneumonia was 11.5%. Thus, pneumonia caused by H. influenzae affects mainly patients with advanced HIV disease, and since its clinical and radiological features may be diverse, this etiology should be considered when pneumonia occurs in patients with advanced HIV infection. The mortality rate associated with H. influenzae pneumonia is not higher than that occurring in the general population.

AIDS-Related Opportunistic Infections↗
PubMed2000

Community-acquired bacterial pneumonia in human immunodeficiency virus-infected patients: validation of severity criteria. The Grupo Andaluz para el Estudio de las Enfermedades Infecciosas.

Severity criteria for community-acquired pneumonia (CAP) have always excluded patients with human immunodeficiency virus (HIV) infection. A 1-yr, multicenter, prospective observational study of HIV-infected patients with bacterial CAP was done to validate the criteria used in the American Thoracic Society (ATS) guidelines for CAP, and to determine the prognosis-associated factors in the HIV-infected population with bacterial CAP. Overall, 355 cases were included, with an attributable mortality of 9.3%. Patients who met the ATS criteria had a longer hospital stay (p = 0.01), longer duration of fever (p < 0.001), and higher attributable mortality (13.1% versus 3.5%, p = 0.02) than those who did not. Three factors were independently related to mortality: CD4(+) cell count < 100/microl, radiologic progression of disease, and shock. Pleural effusion, cavities, and/or multilobar infiltrates at admission were independently associated with radiologic progression. A prognostic rule based on the five criteria of shock, CD4(+) cell count < 100/microl, pleural effusion, cavities, and multilobar infiltrates had a high negative predictive value for mortality (97.1%). The attributable mortality for severe pneumonia was 11.3%, as compared with 1.3% for nonsevere disease (p = 0.008). The ATS severity criteria are valid in HIV-infected patients with bacterial CAP. Our study provides the basis for identification of patients who may require hospitalization determined by clinical judgment and the five clinical criteria of shock, a CD4(+) cell count < 100/microl, pleural effusion, cavities, and multilobar involvement. These prognostic factors should be validated in independent cohort studies.

AIDS-Related Opportunistic Infections↗
PubMed1999

A comparison of graft implantation techniques for hair transplantation.

Modern hair restoration surgery involves moving hair-bearing grafts from the posterior scalp into areas of hair loss for correction of androgenic alopecia. Over the past decade, this procedure has been refined in multiple ways for the creation of increasingly natural results. The following is a comparison of commonly used graft harvesting, sectioning, and implantation techniques currently in use for hair restoration today. This comparison includes data on total procedure time, graft cutting time, graft insertion time, labor requirements, and cost.

Alopecia↗
PubMed1999

Face lift and hair transplantation as a single procedure.

Frequently, when a face lift procedure is performed, several pieces of healthy scalp are discarded as waste unless a prehairline incision is used. In selected cases, such as patients with hair loss, these pieces of scalp may be used to create micrografts (grafts with 1 to 2 hairs) and minigrafts (grafts with 3 to 4 hairs) and transplanted to the areas of need in the same session. I have found particularly rewarding the combination of face lift and hair transplantation, because patients who need both procedures benefit immensely by doing them together. This way, the pieces of healthy scalp that normally would have gone to waste are recycled. In a preliminary fashion, a strip of retroauricular and occipital scalp that normally would be discarded is harvested from one side and handed to my assistants. Under magnification, they dissect it into micrografts and minigrafts as I do the face lift on that side. When I go to the second side of the face lift, I give them the other strip of scalp; again, as they dissect it into grafts, I continue with the face lift. Usually, we generate about 1000 micrografts and minigrafts from those strips that would have normally been discarded. If I want more grafts, I would (in a preliminary fashion) harvest the donor strip of the size required. As the face lift with or without eyelids is completed, we usually have the grafts ready for insertion. Today, we are able to transplant approximately 1000 grafts in about 1 hour. Therefore, combining the two procedures adds only about an hour to our surgical and anesthesia time.

Combined Modality Therapy↗
PubMed1998

The use of micrografts and minigrafts for the correction of the postrhytidectomy lost sideburn.

A tell-tale and unsightly deformity that can result from a rhytidectomy is the loss of the sideburn. As redundant skin is lifted, the hairless skin of the cheek may be advanced into the sideburn area. Several techniques have been described for sideburn reconstruction, mainly punch grafts and various scalp flaps. I use micrografts and minigrafts to effectively correct this deformity in a single session, under local anesthesia and mild intravenous sedation. I use basically the same technique previously described for the treatment of male-pattern baldness, with the direction of graft insertion being at a very acute angle to obtain the growth of hair in a natural downward direction. I found the procedure safe and predictable, and the patients treated were very satisfied with the aesthetically pleasing and natural result.

Female↗
PubMed1997

Micrograft and minigraft megasession hair transplantation results after a single session.

The purpose of this article is to share observations made after performing 90 consecutive micrograft and minigraft megasessions for the treatment of male pattern baldness. Micrograft means grafts with 1 or 2 hairs, minigrafts are those with 3 or 4 hairs, and a megasession is a procedure in which more than 1000 micrografts and minigrafts are inserted in a single session. Between March of 1994 and June of 1996, the author performed 90 consecutive micrograft and minigraft megasessions on 86 men and 4 women ranging from 21 to 67 years of age (average age, 42 years). The surgical team consisted of three surgical assistants and a plastic surgeon. Today, usually between 1500 and 2000 grafts per session are performed in about 4 to 6 hours, with up to 2495 grafts done in a single session. All procedures were done under intravenous sedation and local anesthesia. A donor horizontal ellipse of scalp is harvested from the occipital area; the grafts are made out of it and then inserted through small slits. The procedure has been found to be safe and predictable with natural and aesthetically pleasing results, and there were no serious complications. The only complication found in this group was self-resolving inclusion cysts (ingrown hairs) occurring in 9 of 90 patients (10 percent). Even though the hair density achieved in a single megasession is limited, there is a high level of patient satisfaction: 83 of 85 patients were satisfied (97.65 percent).

Adult↗
PubMed1997

Complications of super-selective subarachnoid anesthesia (SSA) with hyperbaric bupivacaine: experiences with 355 patients in general and orthopaedic surgery.

The results obtained from 355 patients of both sexes subjected to general and orthopaedic surgery with super-selective subarachnoid anesthesia (SSA) by means of small (26-27 gauge) needles with a modified Whitacre needle with ogival point are described. The use of thin spinal needles with "pencil-point" type ends together with microdoses of local anesthetics has meant a reduction in the complications typical of this technique such as hypotension, post-dural puncture, headache (PDPH) and urinary retention. Super-selective subarachnoid anesthesia realised through an infusion of 0.8-1 ml of hyperbaric bupivacaine is a safe effective technique with a low percentage of side-effects.

Adolescent↗
PubMed1993

[DNA identification of human papillomavirus in anogenital condyloma of a male population].

Human Papillomaviruses (HPV) are the cause of benign human anogenital lesions where HPV 6 and HPV 11 are most commonly found. Conversely, HPV 16, 18, 31 and 33 are frequently detected in genital carcinomas and are thus considered as oncogenic types. In order to analyze the prevalence of specific HPV types in an Argentine male population, 43 anogenital lesions from different patients with diagnosis of condyloma acuminata were analyzed. These lesions were localized in different regions of the male genitalia comprising the corona glandis, urethral meatus, skin of the penis, scrotum and anus. The biopsies were screened for the presence of HPV 6, 11, 16, 18, 30, 31 and 33 by Southern blot at different stringent conditions of hybridization (Tm -48 degrees C and Tm -20 degrees C). HPV DNA was found in 41 examined cases (95.3%) with a clear prevalence of HPV 6 and HPV 11 types (51.2% and 23.3% respectively). Six samples (14.0%) were positive only under nonstringent conditions of hybridization. Mixed infections between HPV 16, 18, 30, 31, 33 or a HPV 30 related type with HPV 6 or HPV 11 were detected in 8 specimens (18.6%). Only one case was between HPV 16 and HPV 30. Two additional samples were only positive for HPV 30. Experiments in progress about the prevalence of HPV types in female lesions as well as in normal subjects will contribute to complete the description of the epidemiology of these infections in Argentina.

Adult↗