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Biomedical subjects

A Melchor

Publications and source records attributed to A Melchor.

18 recordsLinked to original sources

Antigenicity of chimeric synthetic peptides based on HTLV-1 antigens and the impact of epitope orientation.

The present study evaluated four chimeric synthetic peptides incorporating immunodominant sequences from HTLV-1 virus. Monomeric peptides M1, M2, and M3 represent sequences from core (p19) and envelope (gp46) of the virus. The peptide M1 is a p19 (105-124) sequence, the peptide M2 is a gp46 (190-207) sequence, and the peptide M3 is a gp 46 sequence with substitution of proline at position 192 by serine. Those peptides were arranged in such a way that permits one to obtain different combinations of chimeric peptides (M1-M2, M2-M1, M1-M3, and M3-M1). Two glycine residues were used as arm spacers for separating the two sequences. The antigenicity of these peptides was evaluated in an ultramicroenzyme-linked immunosorbent assay (UMELISA) using sera of human T cell leukemia virus type I (HTLV-I)-infected individuals (n = 24), while specificity was evaluated with anti-HTLV-II-positive samples (n = 11) and healthy blood donors (n = 25). The results were compared to plates coated with monomeric peptides M1, M2, and M3. The chimeric peptide orientation (M1-M2) and the proline at position 192 of the gp46 peptide showed higher sensitivity.

Amino Acid Sequence↗

Chimeric synthetic peptide as antigen for immunodiagnosis of HIV-1 infection.

One chimeric peptide incorporating antigenic sequences from the gp41 transmembrane region (peptide H-18) and the gp120 envelope region (peptide H-15) corresponding to amino acids (587-617) on gp41 and (495-516) on gp120 of human immunodeficiency virus (HIV 1) was synthesized. Both sequences were separated by two glycine residues. This peptide was evaluated as antigen in an ultramicro-enzyme-linked immunosorbent assay (UMELISA) with samples derived from HIV-1 (n = 30) with different titers of antibodies and healthy blood donors (n = 30). The results were compared to plates coated with monomeric peptides and to plates coated with two monomeric peptides together. Results demonstrated that monomeric peptides gp41 (H-18) and gp120 (H-15) were good as antigens with samples that present antibodies to these regions. The chimeric peptide was the most antigenic. Those results may be related to the peptide structure, adsorption to the solid surface, and epitope accessibility to the antibodies. This chimeric peptide would be very useful for HIV-1 diagnostics.

AIDS Serodiagnosis↗

[Traffic accidents: a health problem in primary care].

OBJECTIVE: To discover the prevalence and most relevant epidemiological characteristics of the victims of traffic accidents which occur in our health area. SETTING: Hospital Casualty department (HC), Health area 19, Alcoy. PATIENTS: This was an observational, crossover study, based on the collection of data from all those patients who had been brought into the HC for attention because of a traffic accident and who were attended between October 1, 1990 and September 31, 1991. MEASUREMENTS AND MAIN RESULTS: During the study period a total of 1,111 traffic accident victims were attended. Their average age was 26.62 (SD +/- 15.95), with 69.6% being men and 30.2% women. 60.7% of the victims were attended on non-working days or the eve of a non-working day. 44.5% of those involved in accidents were in four-wheeled vehicles; 40% on two-wheeled vehicles and 11.1% of the victims were pedestrians. Injuries were light in 73.3% of cases; moderate in 15.9% and in the other 8.8% serious, grave or critical. 43.7% of the total had the accident in an urban area and 40.9% on the open road. CONCLUSIONS: The high prevalence of victims of accidents (8.3 per 1000 inhabitants) observed in our health area can be explained by the type of study. It is vital to obtain valid information of the real importance of this health problem. The primary care doctor must take preventive action concerning traffic accidents: a) through full studies of traffic accident levels among primary care centre users; b) primary preventive action, through the spreading of information on norms of safety; and c) secondary and tertiary prevention, by means of effective and efficacious outpatient emergency measures, as well as a thorough rehabilitation of accident victims.

Accidents, Traffic↗

[Clinical features of migraine according to the questionnaire 'Alcoi-92' in the Comtat area].

INTRODUCTION: Headache is one of the commonest reasons for consultation and it might be useful to know its characteristics in order to determine which patients may need medical attention. OBJECTIVES: To carry out a randomized transverse study in a rural population using the validated questionnaire 'Alcoi-92', and to determine the clinical characteristics of the headaches detected. PATIENTS AND METHODS: A door to door survey was done by randomized selection of 790 persons aged over 18 and living in the Comarca del Comtat. A validated self-questionnaire was sent and this was followed by an interview with a doctor. RESULTS: Five hundred and forty-eight persons were interviewed. The standard prevalence of migraine is 19.6% with a sex incidence of 1:2.4 and an average age of 46.1 years. The average age of onset was 20.64 years. There were family histories of cerebrovascular accidents in 26.4% and of migraine in 57.1%. There were no differences in the use of toxic substances, of socio-economic status or of marital status. The commonest pre-existing pathology was arterial hypertension. The number of episodes of headache was one to seven per year in 50% of those with migraine, with an average duration of 4-24 hours, predominantly bilateral presentation and pulsatile in character with moderate repercussion in everyday activities. The commonest associated symptoms were photophobia and sonophobia. There were prodromal symptoms in 36.9%, most commonly confusion and photopsy. CONCLUSION: The questionnaire 'Alcoi-92' has been shown to be a useful tool for definition of the clinical characteristics of migraine.

Adolescent↗

[A descriptive study of migraine in a rural population of Area del Comtat].

INTRODUCTION: Headache is one of the commonest causes of consultation in neurology. There are many studies of the prevalence of migraine showing considerable variation in the results obtained. OBJECTIVES: To find the prevalence of migraine, with and without an aura, by means of a randomized transverse study carried out in a previously selected rural population, using the validated questionnaire 'Alcoi-92'. To find the overall prevalence of migraine, specifically regarding age and sex and adjusted for the European population. PATIENTS AND METHODS: A door-to-door study was made by random selection of 790 persons aged over 18, in three towns in the comarca del Comtat, Alacant, Spain. A self-questionnaire was sent to all persons studies and subsequently they were seen by a medical interviewer. RESULTS: We interviewed 548 persons (overall response rate 78%). The average age was 52.5 +/- 19.3 years. Sex distribution of the population interviewed showed a predominance of females (52.9%) as compared to males (47.1%). According to the type of headache: other types of headache 62.32%, persons with no previous history of headache 20.07%, amplified migraine 16.6%, typical migraine 12.6%, cluster type migraine 0.18%. CONCLUSIONS: The overall prevalence of amplified migraine was 16.6%. According to diagnostic groups the frequency of migraine with aura was 2.9%, migraine without aura 9.7% and typical migraine 12.6%. A predominance of women was seen in all types of migraine. The frequency of migraine, adjusted for the European population was 19.6%. Prevalence during the past year, as a measure of activity of the disorder was 15.7%.

Catchment Area, Health↗

[Indirect ultramicroElisa for the detection of total antibodies against cytomegaloviruses in human blood].

We have standardized an indirect ultramicro ELISA assay for detecting antibodies to human Cytomegalovirus (CMV) using human serum samples (UMELISA CMV). The optimal concentration of coating antigen (30 ug/ml), serum dilution (1:40) and anti-human conjugate working dilution (1:1500), were determined by a check board titration method. The UMELISA CMV was compared with the latex agglutination test for antibodies to CMV (Dupont de Nemours) and with an indirect immunofluorescent method. The results have showed the high coincidence, sensitivity and especificity of the proposed assay regarding the two methods compared with, and supporting its use either for a blood donors screening or in the serological diagnosis of this infection by paired serum samples.

Antibodies, Viral↗