Search PubMed⌕ Search

Biomedical subjects

L Aguilar

Publications and source records attributed to L Aguilar.

142 records · Page 8Linked to original sources
PubMedDate not supplied

Current prevalence of hepatitis B, A and C in a healthy Spanish population. A seroepidemiological study.

A seroepidemiological study was carried out in order to determine the prevalence of markers of viral hepatitis infection in employees of five health-care companies and their cohabiting family members. Each participating family unit was required to fill out a questionnaire, in which, among other data, the employee was requested to indicate his or her job category. Markers of hepatitis B infection (anti-HBs, anti-HBc or HBsAg) were observed in 11.7% (58/497) of all subjects. When employees and family members were analysed according to the employee's job category, significant differences were found between "staff" (3%) and "administrative personnel" (13.3%; p less than 0.01) or "factory workers" (16.9%; p less than 0.01). Of 489 individuals tested for the presence of anti-HAV and anti-HCV, 59.1% and 0.6% respectively, were positive. There was a correlation between the prevalence of anti-HAV and age; a large proportion of the subjects under the age of 30 years had no evidence of prior HAV infection.

Adolescent↗
PubMedDate not supplied

A seroepidemiologic study of hepatitis A in Spanish children. Relationship of prevalence to age and socio-environmental factors.

Three child population groups from the Madrid area were studied for anti-HAV antibodies. Analysis was carried out with respect to age and socio-environmental factors. The population understudy was composed of 156 children, with ages ranging from 1 to 14 years; they were stratified in three socio-environmental groups (white-family unit, gypsy-family unit and orphanage), and also divided into subgroups according to age. As a whole, an age-related increase in prevalence was found. The overall seroprevalence by socio-environmental groups was: gypsy-family unit 63%, orphanage 46%, and white-family unit 23%. Significant differences between groups appeared from seven years on, being more marked among the eldest subgroups. Among the factors evaluated, hygienic-sanitary conditions and overcrowding influenced the high prevalence rate found in the gypsy-family unit subjects, whereas overcrowding appeared to be responsible for the higher prevalence in orphanage residents, as compared to white-family unit children.

Adolescent↗
PubMedDate not supplied

Identification of phosphatidate nonlamellar phases on liposomes by flow cytometry.

This study is the first report that demonstrates nonlamellar arrangements, or lipidic particles, of phosphatidate inserted in the lipid bilayer of liposomes using polyclonal antibodies from mice and flow cytometry. Sera immunoreactivity was analyzed using liposomes that displayed smooth bilayers of phosphatidate particles, as shown by electron microscopy. This cytofluorimetric analysis showed that immune mice sera have a specific immunoreactivity with the phosphatide particles formed by Mn2+, which also cross-reacted with those formed by Ca2+ and with cardiolipin particles formed by Mn2+. In addition, these immune sera hardly reacted with smooth bilayered liposomes, independently of the lipid composition studied. Thus, this new methodology can be applied to demonstrate nonlamellar molecular arrangements in biological membranes.

Animals↗
PubMedDate not supplied

[Hiatal hernia in asthmatic patients: prevalence and its association with gastroesophageal reflux].

INTRODUCTION: Evidence of a high prevalence of hiatal hernia (HH) and gastroesophageal reflux (GER) in asthmatic patients has been found. However, the relationship between these entities has not been studied in our country. OBJECTIVES: 1) To inform the prevalence of hiatal hernia in asthmatic patients, 2) To compare the prevalence of hiatal hernia in asthmatic vs. non-asthmatic patients, 3) To establish a possible association between hiatal hernia and GER in asthmatic patients. MATERIALS AND METHODS: In order to detect and to compare the prevalence of hiatal hernia in asthmatic and non-asthmatic patients, upper gastrointestinal endoscopy was performed. To establish the association between asthma and GER, data obtained from a gastrointestinal symptoms questionnaire, an esophageal manometry and an ambulatory pH recording in asthmatics with or without hiatal hernia were compared. RESULTS: Hiatal hernia was more frequently observed in asthmatics than in non-asthmatics (62% vs. 34%, p = 0.02). The frequency of typical symptoms of GER was similar in both asthmatics with or without hiatal hernia (54 vs. 43%, p = 0.3). Lower esophageal sphincter incompetence was similar in asthmatics with hiatal hernia (35%) vs. asthmatics without hiatal hernia (22%), as detected by manometry. Pathological GER was diagnosed by pH recording in 81% of the asthmatics with hiatal hernia and in 65% of asthmatics without hiatal hernia (p = 0.1). CONCLUSIONS: There is a high prevalence of hiatal hernia in asthmatics, which in turn results to be greater than in non-asthmatic patients. The presence of hiatal hernia does not correlate with the detection of pathological GER as determined by pH recording in this group of patients.

Adult↗
PubMedDate not supplied

[Gastroesophageal reflux in asthmatic patients: an incidence study and clinical correlation].

The prevalence of gastroesophageal reflux (GER) in asthmatic patients is elevated, but the exact frequency remains unknown. The relationship between GER and asthma has not been investigated in Mexico. The objective of this study is to know the frequency of GER in Mexican asthmatic patients and the possible relationship with the severity of asthma. Fifty patients with adult-onset asthma were studied. AII of them fulfill the diagnostic criteria of the National Institutes of Health, U.S. The evaluation included a symptoms questionnaire, spirometry, esophageal manometry, 24-h esophageal pH-recording, and an upper gastrointestinal endoscopy. Twenty-three patients had mild asthma (46%), 16 moderate (32%) and 11 had severe asthma (22%). Twenty-seven (54%) reported heartburn and regurgitation at least twice a week. The esophageal pH-recording showed pathologic GER in 37 subjects (74%) and endoscopic esophagitis was found in 7 cases (14%). The pH-recording showed pathologic GER in 13 patients with mild asthma (57%), in 13 with moderate asthma (81%) and in all patients with severe asthma (100%). The frequency of GER in Mexican asthmatic patients is high and increases proportionately with the severity of asthma. This factor must be considered in the integral evaluation of these patients.

Adult↗
PubMedDate not supplied

Electron microscopy and biological properties of pBR322 DNA condensed with the trivalent cations spermidine and hexammine cobalt (III).

Electron microscopy and the biological properties of susceptibility to DNase I, genetic transcription, and transformation of pBR322 DNA compacted with spermidine or hexammine cobalt (III), were analyzed in order to characterize the association of DNA in its compacted form with these two different trivalent cations. Spermidine and hexammine cobalt (III) produced an average 4-fold reduction of the DNA perimeter in compact DNA forms, which were doughnut-shaped toroids and cylinders. Both compacted DNAs were resistant to the hydrolytic activity of DNase I. However, spermidine-condensed pBR322 DNA was 10-fold and 4 to 6-fold more active in transcription and transformation, respectively, than naked pBR322. I. Hexammine cobalt (III)-condensed pBR322 was inactive in both biological properties. An inhibitory effect of hexammine cobalt (III) on RNA polymerase and genetic transformation activities was discarded because at higher ionic strength, in which DNA is not compacted by hexammine cobalt (III), transcription and transformation were similar to those observed with naked DNA. This information showed that the interaction of hexammine cobalt (III) with the DNA converted the pBR322 DNA into an inert molecule. In contrast, pBR322 did not loose its biological properties after its interaction with the polyamine spermidine; i.e., experimental condensation of pBR322 DNA by spermidine produced compacted DNA that is more similar to compact native genomes than relaxed DNA. These experiments led us to conclude that spermidine-condensed DNA can be used to study the roll of the native supercoiling of DNA in the regulation of genetic replication and transcription, as well as to study the mechanisms that allow the accessibility of the supercoiled or condensed DNA substrate for enzymes.

Cations↗
PubMedDate not supplied

[Acute glomerulonephritis in children: long-term prognosis].

Sixty-five children were studied for over five years following an acute glomerulonephritis episode. Proteinuria was detected in 15 but in one, it was massive proteinuria with edema and low renal function. The other 14 children were asymptomatic and proteinuria was close to or below 0.5 gms/24hs. Only one out of 10 renal biopsies was normal. Focal mesangial proliferation was described in 9. Such renal lesion was considered as residual rather than active. From these results it is concluded that the prognosis of acute glomerulonephritis in children is good in 98% of cases.

Acute Disease↗
PubMedDate not supplied

[Acute glomerulonephritis in children. I. Clinical manifestations].

The symptoms and short-term evolution of 617 patients with acute glomerulonephritis are discussed. Edema was the most frequent symptom (93%) at the time that gross hematuria was only present in 65% of cases. On the other side, heart failure was detected in 33% of patients and neurological symptoms in 6%. Short-term follow-up of 381 of these patients show that microscopic hematuria cleared up after six months in 73% of cases, but lasted more than one year in only 4% of patients.

Acute Disease↗
PubMedDate not supplied

[Familial incidence of post-streptococcal glomerulonephritis].

The investigation on siblings of AGN patients has shown a streptococcus carrier evidence of 45%, while glomerulonephritis incidence was 15%. These data allowed us to classify our population as highly susceptible to bacterial dissemination and to the development of non-suppurative complications. Renal compromise was clinical and histologically classified. Subclinical forms showed glomerular lesions of mesangial localization, while clinical forms exhibited variable degrees of cellular proliferation. All patients recovered except one who died of a rapidly progressive form.

Adolescent↗