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Biomedical subjects

M Avila

Publications and source records attributed to M Avila.

31 records · Page 2Linked to original sources
PubMed1990

A phospho-oligosaccharide can reproduce the stimulatory effect of insulin on glycolytic flux in human fibroblasts.

It has been recently demonstrated that insulin promotes the hydrolysis of a glycosyl-phosphatidylinositol, stimulating the release of a phospho-oligosaccharide which displays several insulin-like effects. In the present study we have investigated whether the compound is able to mimic insulin action on glucose metabolism in human fibroblasts. Similarly to the hormone, the phospho-oligosaccharide elicited a dose dependent increase in lactate output and fructose 2,6-bisphosphate content. The effect of the compound was time dependent with a progressive increase starting from 2 hours of incubation. 1 microM phospho-oligosaccharide had half maximal effect on both parameters, increasing glycolytic flux by approximately 30% and fructose 2,6-bisphosphate content by 70%. Therefore the phospho-oligosaccharide appears to be able to strictly reproduce insulin action on glucose metabolism in human fibroblasts.

Cells, Cultured↗
PubMed1988

Anaphylaxis to amoxycillin but good tolerance for benzyl penicillin. In vivo and in vitro studies of specific IgE antibodies.

Three patients are reported on who suffered anaphylactic reactions after amoxycillin (AX) treatment and challenge but tolerated benzylpenicillin (BP) parenterally and orally. Two of the three patients had positive skin tests and RAST to AX reagents but negative responses to benzyl penicilloyl (BPO) specific skin tests and RAST and the minor determinant mixture (MDM) skin test reagent. The third case was negative to all skin tests and RAST. RAST and RAST inhibition on the two positive sera suggest that the response is related to the acyl side chain of AX.

Adult↗
PubMedDate not supplied

Epidemiologic risk factors for children with acute lower respiratory tract infection in Buenos Aires, Argentina: a matched case-control study.

The risk factors that predisposed 516 hospitalized and 154 ambulatory patients to acute lower respiratory tract infection (ALRI) are examined in a matched case-control study. The control group was selected from children attending immunization and well-baby clinics at the same institution that was treating the children with ALRI. Sex, age, nutritional status, socioeconomic level, as well as season and place of residence were used as matching criteria. Because of their distinct profiles, hospitalized and outpatient groups were analyzed separately. However, the four variables with the highest odds ratios (incidence ratios or relative risk) were found to be the same for both groups. These variables were related to the host's condition (bronchial hyperreactivity, presence of persistent symptoms of the upper respiratory tract), family (presence of acute respiratory tract disease in household members), and environment (indoor contaminants).

Acute Disease↗
PubMedDate not supplied

Etiologic, clinical, and pathologic analysis of 31 fatal cases of acute respiratory tract infection in Argentinian children under 5 years of age.

During a 3-year survey of 805 children with acute lower respiratory tract infection (ALRI) who were admitted to three hospitals in Buenos Aires, 31 fatal cases were recorded--a fatality rate of 3.8%. Of the 31 children who died, 77% were less than 1 year of age, 48% were boys, 58% were malnourished, 29% had previous respiratory disease, and 22% had previous congenital disease. All children who died had clinical diagnoses of pneumonia (71%) or bronchiolitis (29%). Autopsies were performed in 14 of the cases. Viral etiology was determined by both cell culture and indirect immunofluorescence (IIF) assay of either nasopharyngeal aspirates (NPA) or lung tissue and bacterial etiology was determined by isolation of organisms from blood, lung tissue, and/or pleural fluid. NPA was examined for Bordetella pertussis by IIF. Pathogens were identified in 65% of fatal cases. Seven cases were bacterial; seven cases were viral; and six cases resulted from mixed infections. Lung tissue yielded positive etiologic results in 10 of 13 cases. Histopathologic examination performed on specimens from the 14 autopsied children revealed necrotizing bronchiolitis with intranuclear inclusions (n = 5) and multifocal pneumonia (n = 9).

Acute Disease↗
PubMedDate not supplied

Etiologic and clinical evaluation of acute lower respiratory tract infections in young Argentinian children: an overview.

This paper summarizes the first study on clinical, etiologic, and epidemiologic features of acute lower respiratory tract infection (ALRI) in children in Argentina. A total of 1,003 children less than 5 years of age (805 inpatients and 198 outpatients) presenting with ALRI were studied during a 40-month period. Nasopharyngeal aspirate (NPA), blood, urine, and throat-swab samples were collected when each child was first seen for care. Virologic studies were performed on the NPA by means of indirect immunofluorescence and isolation of virus in cell culture. Bacteriologic studies primarily were done by means of culture of blood or pleural fluid (when available); Bordetella pertussis and Mycoplasma pneumoniae, however, were searched for by the use of immunofluorescence and complement-fixation testing, respectively, in paired sera. Respiratory syncytial virus was the most commonly isolated virus, followed by adenovirus, parainfluenza virus, and influenza virus. Streptococcus pneumoniae was the most frequently isolated bacterium, followed by B. pertussis and Haemophilus influenzae type b. Overall, the patient fatality rate was 3.8% among inpatients with pneumonia or bronchiolitis.

Acute Disease↗
PubMedDate not supplied

Isolation and identification of viral agents in Argentinian children with acute lower respiratory tract infection.

From a total population of 1,002 children with acute lower respiratory infection (ALRI), identification of virus was achieved in 304 cases. In this survey, 1,000 nasopharyngeal aspirate and 13 lung tissue samples were tested in four cell lines (HEp-2, MRC-5, MDCK, and LLC-MK2) and by indirect immunofluorescence (IIF), while 242 paired sera were studied by complement fixation. Respiratory syncytial virus (RSV) was the most frequently detected agent (n = 183), followed by adenovirus (n = 28), parainfluenza (n = 5) and 3 (n = 16) viruses, and influenza A (n = 10) and B (n = 4) viruses. The sensitivity and specificity of IIF identification vs. isolation in cell culture were high for RSV (91.5% and 94.9%, respectively). However, IIF proved poorly sensitive for detection of adenovirus (sensitivity, 23.8%; specificity, 100%). The complement-fixation test proved the least effective, with a sensitivity of only 41.5%. Therefore, on the basis of our experience, it appears that the yield for positive diagnosis of virus is increased if both isolation in multiple cell lines and identification by means of IIF are used. Our survey provides for the first time reliable data on the viral etiology of ALRI in Argentina, as determined by three different methods.

Adenoviruses, Human↗
PubMedDate not supplied

Adenovirus type 7h respiratory infections: a report of 29 cases of acute lower respiratory disease.

Twenty-nine cases of pediatric acute lower respiratory disease associated with adenovirus genome type 7h were evaluated retrospectively. They constituted 2.4% of 1233 cases of acute respiratory infections treated in five hospitals in Buenos Aires, between September 1984 and September 1988. Pneumonia and bronchiolitis were the principal diagnoses. The mean age of patients was 8.8 months and 82.7% of the children were less than one year of age. None of the patients had previously been exposed to measles or was immunocompromised. A mixed infection, viral or bacterial, was demonstrated in 8 of the 29 patients. Sixteen children developed a severe pulmonary disease which required intensive care. Ten with a clinical diagnosis of multifocal pneumonia and necrotizing bronchiolitis died. Extrapulmonary manifestations were observed in the most severe cases. Observations suggest a possible high pathogenicity of adenovirus type 7h and emphasize the need for adequate control and case management programs.

Acute Disease↗
PubMedDate not supplied

HLA-B27 subtypes in patients with ankylosing spondylitis (As) in Colombia.

OBJECTIVE: We investigated the distribution of HLA-B27 subtypes in patients with ankylosing spondylitis (AS) belonging to two ethnic groups of Colombia. MATERIAL AND METHODS: PCR-SSOs was used to detect the polymorphism in exons 2 and 3 of HLA-B27 in two groups of patients: 39 Mulattos and 20 Mestizos. Fifty-nine of them suffered of ankylosing spondylitis (AS), including two patients with ankylosing spondylitis plus anterior uveitis (AU). Only two out of eight HLA-B27 subtypes studied (B*2701-B*2708) were found. RESULTS: The distribution of these alleles in the whole population was: B*2705: 87.1% and B*2702: 12.8% in the Mulattos group; 80% were B*2705 and 20% B*2702 in Mestizos group. The distribution of HLA-B27 subtypes was: 84.74% of patients with AS were B*2705 and 15.26% B*2702. CONCLUSIONS: There was no significant difference in the distribution of HLA-B27 subtypes among the patients ethnic groups studied. Other authors have shown that B*2705, B*2702 and B*2704, the more frequent subtypes, are equally associated to the disease. Although population studies need to be done to analyze the distribution of subtypes between patients and controls, the low frequency of HLA-B27 within the normal population does not permit to do a representative number of controls; our results suggest that HLA-B*2705 and HLA-B*2702 are the subtypes more frequently associated with AS in patients from the two more prevalent patients ethnic groups in Colombia.

Alleles↗
PubMedDate not supplied

GGRGDSPCA peptide: a new antiscarring agent on glaucoma filtration surgery.

BACKGROUND AND OBJECTIVE: GGRGDSPCA synthetic peptide competes for integrin receptor in scar formation after glaucoma filtering surgery in a rabbit model. The purpose of this study was to evaluate the use of this peptide and compare it with mitomycin on glaucoma filtering surgery. MATERIALS AND METHODS: Posterior sclerectomy was performed in both eyes of 17 rabbits. The right eye received GGRGDSPCA (p605) at 0, 4, 8, 12, and 16 days after. Nine left eyes received saline as a control; the remaining 8 eyes received mitomycin C at 0.5 mg/mL intraoperative. Intraocular pressures and biomicroscopy were evaluated as well as bleb function. RESULTS: Intraocular pressure decreased significantly in both the peptide and mitomycin treated eyes in comparison with the saline group (P = 0.0003). Pressure was similar in both groups. The blebs showed filtrating function in a functional analysis at day 21 and 41 in the mitomycin cases as well as in the peptide group. Histologic analysis performed in both peptide and mitomycin groups showed inhibitory effect in fibrocellular and collagen organization with bleb formation. CONCLUSIONS: The p605 peptide showed to be similar to mitomycin C in controlling and improving glaucoma filtering surgery in rabbits. This alternative may potentially be useful for similar purposes in humans for the control of glaucoma and improvement of filtering surgery.

Animals↗
PubMedDate not supplied

Ameloblastic fibrosarcoma: report of a case. Immunohistochemical study and review of the literature.

Ameloblastic fibrosarcoma is a rare malignant odontogenic tumour characterized by a benign epithelial component within a malignant fibrous stroma. Its behaviour is relatively benign, with absence of metastatic disease, and the prognosis is reported to be good. It is a paradoxical neoplasm with "sarcomatous" morphological and immunohistochemical patterns but with a favourable clinical course. We report a new case of this tumour in a mandibular ramus of a 31-years-old male patient, that was surgically excised and treated with adjuvant chemotherapy and radiotherapy. Five years later the patient is free of disease. The growth potential of ameloblastic fibrosarcoma is evaluated and compared with a related lesion, the ameloblastic fibroma. The sarcomatous mesenchymal component of ameloblastic fibrosarcoma is positive to Ki67, PCNA and p53, in front of the negativity of ameloblastic fibroma.

Adult↗
PubMedDate not supplied

[Serologic response measured by complement fixation in children with acute respiratory infection].

The aim of this work was to evaluate the sensitivity of complement fixation for serological diagnosis of lower acute respiratory infections (ARI) in small children in comparison with direct methods such as indirect immunofluorescence (IIF) on nasopharyngeal aspirate and tissue culture isolation. Sera from children under 5 year of age with ARI were studied by complement fixation for 6 respiratory viruses (respiratory syncytial virus (RSV), adenovirus, influenza A and B and parainfluenza 1 and 3). In all, 264 pairs of serum samples from children with viral ARI diagnosis (n:135) or from doubtful cases (n:90) were studied. Thirty nine sera were anticomplementary. In samples from confirmed viral ARI patients, seroconversion was detected in 38%, whereas from those with a doubtful diagnosis it was only 14%. Seroconversion for RSV and adenovirus was 39% and 50%, respectively. On correlating seroconversion for the 6 viruses according to age group, 20% positivity was found in the 0-5 month-old group, 35% in the 6-10 month-old and 30% in those over 11 months of age. For RSV alone, 0-5 month-old patients presented 25% seroconversion, and in those over 6 months of age the percentage exceeded 60% (p less than 0.001). Complement fixation test sensitivity vs direct methods (IIF and/or culture) was 38.5%). Our findings confirm the low sensitivity of complement fixation to detect antibodies in ARI, particularly in children under 6 months of age and support the higher efficacy of direct diagnostic methods. However, complement fixation serology is useful for epidemiological studies in children over 6 months of age, since over 60% of RSV were readily detected.

Child, Preschool↗