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1.
Allergol Immunopathol (Madr) ; 48(6): 560-567, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32423618

RESUMO

INTRODUCTION: Eosinophilic oesophagitis (EoE) is a chronic clinical-pathological disorder with an immunological basis characterised by symptoms of oesophageal dysfunction and, histologically, eosinophilic inflammation. OBJECTIVE: To evaluate the clinical characteristics and differences in children and adults diagnosed with EoE in a tertiary level hospital. METHOD: Descriptive, retrospective and cross-sectional study. We randomly selected 40 children and 40 adults diagnosed with EoE between 2009 and 2016. The patient characteristics were analysed by means of epidemiological, clinical, diagnostic and therapeutic variables. RESULTS: The average age at diagnosis was 10 years (children) and 34 years (adults), with a higher frequency in males. The majority were sensitised to aeroallergens (77.5% children vs. 82.5% adults) and foods (75% children vs. 82.5% adults). Statistically significant differences were detected in sensitisation to fruits (p=0.007) and grains (p<0.001). Differences were observed in impaction (22.5% children vs. 82.5% adults), dysphagia (42.5% children vs. 77.5% adults) and abdominal pain (25% children vs. 7.5% adults). Endoscopy showed that children had a higher frequency of exudates (92.5%) and adults, trachealisation (50% vs. 5%) and stenosis (17.5% vs. 2.5%). Statistically significant differences were found in treatment with topical corticosteroids (30% children vs. 77.5% adults), with a variable positive response. 77.5% of the patients received elimination diets. CONCLUSIONS: Statistically significant differences were observed between the paediatric and adult populations in the food sensitisation profiles, clinical manifestations, endoscopic findings and treatments received. This is a complex pathology that calls for a multidisciplinary team and would require new non-invasive techniques to facilitate its management.


Assuntos
Dor Abdominal/epidemiologia , Transtornos de Deglutição/epidemiologia , Esofagite Eosinofílica/imunologia , Mucosa Esofágica/patologia , Hipersensibilidade Alimentar/imunologia , Dor Abdominal/imunologia , Administração Tópica , Adolescente , Adulto , Fatores Etários , Alérgenos/imunologia , Criança , Pré-Escolar , Estudos Transversais , Transtornos de Deglutição/imunologia , Endoscopia/estatística & dados numéricos , Esofagite Eosinofílica/complicações , Esofagite Eosinofílica/diagnóstico , Esofagite Eosinofílica/terapia , Mucosa Esofágica/diagnóstico por imagem , Mucosa Esofágica/imunologia , Feminino , Hipersensibilidade Alimentar/diagnóstico , Hipersensibilidade Alimentar/patologia , Glucocorticoides/administração & dosagem , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Adulto Jovem
3.
Allergol Immunopathol (Madr) ; 44(5): 455-60, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27255475

RESUMO

OBJECTIVE: Examine the prevalence of asthma and associated predictive factors in a group of 468 students. PATIENTS AND METHODS: A descriptive, cross-sectional observational study in a randomly selected population of 468 children aged 10-12, in the city of Zaragoza. We used the ISAAC questionnaire on asthma completed by children under supervision of the investigators. We assessed the genetic risk (family history of asthma) and environmental risks. The risk for atopy was assessed by the presence of positive skin prick tests. RESULTS: 25.3% of the children had symptoms consistent with asthma in the city of Zaragoza. Among them 33.1% reported a history of asthma in close relatives (OR=1.78, p<0.001). The history of hospitalisations for lower respiratory tract illness was strongly associated with the presence of asthma (OR=6.72, p<0.0001). Positive skin tests to Alternaria (OR=2.00, p<0.0001) and grass pollen (OR=1.76, p<0.001) were predictors of asthma. 63.6% of asthmatic children had presented clinical rhinitis in the previous 12 months, compared with 32% of non-asthmatics, and this difference was statistically significant (OR=3.89, p<0.0001). 47% of asthmatics presented with or previously had eczema, whereas only 26.9% of non-asthmatics presented with or previously had these types of lesions (p<0.0001). CONCLUSION: The following are predictors of asthma: History of hospital admissions for lower respiratory tract illness, presence of rhinitis and/or eczema, positive prick test for certain aeroallergens, especially Alternaria and grass pollen, and family history of asthma.


Assuntos
Alternaria/imunologia , Asma/epidemiologia , Hipersensibilidade/epidemiologia , Antígenos de Fungos/imunologia , Antígenos de Plantas/imunologia , Criança , Estudos Transversais , Interação Gene-Ambiente , Humanos , Poaceae/imunologia , Pólen/imunologia , Prevalência , Fatores de Risco , Espanha/epidemiologia , Inquéritos e Questionários
4.
Artigo em Inglês | MEDLINE | ID: mdl-16433206

RESUMO

UNLABELLED: We performed a prospective observational study to establish a relationship between pollen counts of Chenopodiacea/Amaranthacea and clinical symptoms of rhinoconjunctivitis and asthma in a group of monosensitised patients. MATERIAL AND METHODS: A total of 60 patients (19 with asthma) were included in the study. All patients collected daily symptom scores during the summer months of 1999, 2000 and 2001. The questionnaire included ocular, nasal and pulmonary symptoms. Pollen counts were expressed as pollen grains/m3. Symptom scores and pollen counts were correlated using correlation coefficients and Log transformed variables. RESULTS: In the 3 seasons studied we identified a peak of pollen and clinical symptoms in the second half of August and first half of September. In 1999, there was a significant positive correlation between total symptoms and daily pollen grains/m3 (p<0.005, r = 0.347). This correlation was not significant for the summers of 2000 and 2001. After further analysis, and by displacing one of both variables between 11 to 17 days, the correlation coefficients for total symptoms, improved for 1999 (r = 0. 744; p < 0.0001) and became significant for 2000 (r = 0. 521; p < 0.0001) and 2001 (r = 0.635; p < 0.0001). CONCLUSION: We identified a significant time lag between pollen counts and symptom scores in S. kali monosensitized patients.


Assuntos
Amaranthaceae/imunologia , Chenopodiaceae/imunologia , Hipersensibilidade/etiologia , Pólen/imunologia , Salsola/imunologia , Adolescente , Adulto , Alérgenos/análise , Alérgenos/imunologia , Feminino , Humanos , Hipersensibilidade/epidemiologia , Masculino , Pessoa de Meia-Idade
6.
Eur J Hum Genet ; 8(5): 360-6, 2000 May.
Artigo em Inglês | MEDLINE | ID: mdl-10854096

RESUMO

We have analysed a large set of autosomal short tandem repeat (STR) loci in several Arabic and Berber-speaking groups from north-west Africa (ie Moroccan Arabs, northern-central and southern Moroccan Berbers, Saharawis, and Mozabites). Two levels of analysis have been devised using two sets of 12STR loci, (D3S1358, vWA, FGA, THO1, TPOX, CSF1PO, D8S1179, D21S11, D18S51, D5S818, D13S317 and D7S820) and 21 (the former set plus D9S926, D11S2010, D13S767, D14S306, D18S848, D2S1328, D4S243, F13A1, and FES/FPS). For each set, data for a number of external reference populations were gathered from the literature. Several methods of analysis based on genetic distances (neighbour-joining trees, principal coordinate analysis, boundary detection), as well as AMOVA, showed that genetic differentiation among NW African populations was very low and devoid of any spatial pattern. When the NW African populations were grouped according to cultural or linguistic differences, the partition was not associated with genetic differentiation. Thus, it is likely that Arabisation was mainly a cultural process. A clear genetic difference was found between NW African populations and Iberians, which underscores the Gilbraltar Straits as a strong barrier to genetic exchange; nonetheless, some degree of gene flow into Southern Iberia may have existed. NW Africans were genetically closer to Iberians and to other Europeans than to African Americans.


Assuntos
Árabes/genética , Repetições de Microssatélites/genética , Sequências de Repetição em Tandem/genética , África do Norte/etnologia , Heterogeneidade Genética , Genética Populacional , Humanos
7.
Arch Bronconeumol ; 33(9): 444-9, 1997 Oct.
Artigo em Espanhol | MEDLINE | ID: mdl-9424260

RESUMO

Specific bronchial challenge (SBC) testing is a key technique for diagnosing the origin of occupational asthma (OA). SBC is indicated in specific circumstances, including whenever several agents present in the work environment may be the cause of OA, when new or unusual occupational agents need to be identified, when evidence for legal action is required, or when research is conducted. SBC procedures are not standardized, because of the great diversity of occupational agents and the variety of physical and chemical properties involved. Thus, SBC testing with agents found in fumes, gases or vapors can be administered in special cabins or in closed circuits with continuous monitoring of sub-irritant concentrations. Agents found in dust, most but not all of which have high molecular weights, may be appropriate for routine SBC testing in an allergy laboratory. This paper will treat only these cases. SBC must be formed in specialized centers by experienced personnel, as it is a sophisticated and potentially dangerous technique. We describe a series of 20 patients diagnosed of OA in our unit over the past two years in whom SBC provided an etiologic diagnosis. All were exposed to dust or aerosols at work. The cause was a substance of high molecular weight in 17 cases, and low molecular weight in 3. The procedure used is described and models of bronchial response are discussed.


Assuntos
Asma/diagnóstico , Testes de Provocação Brônquica , Doenças Profissionais/diagnóstico , Adolescente , Adulto , Aerossóis , Poluentes Ocupacionais do Ar/efeitos adversos , Alérgenos , Asma/induzido quimicamente , Asma/fisiopatologia , Testes de Provocação Brônquica/métodos , Testes de Provocação Brônquica/estatística & dados numéricos , Poeira/efeitos adversos , Feminino , Humanos , Masculino , Fluxo Expiratório Máximo , Pessoa de Meia-Idade , Peso Molecular , Doenças Profissionais/induzido quimicamente , Doenças Profissionais/fisiopatologia
9.
Clin Infect Dis ; 14(2): 592-3, 1992 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-1554848

RESUMO

The usual battery of skin tests employed for determining penicillin allergy may fail to detect allergic reactions to side chain-specific beta-lactam agents. We report the cases of six patients who experienced anaphylactic reactions after treatment and challenge with amoxicillin but who tolerated parenteral challenges with benzylpenicillin, aztreonam, and ceftazidime. Results of skin tests for amoxicillin (10 mg/mL) were positive for four of the six patients.


Assuntos
Amoxicilina/efeitos adversos , Aztreonam/efeitos adversos , Ceftazidima/efeitos adversos , Hipersensibilidade a Drogas/diagnóstico , Penicilina G/efeitos adversos , Adolescente , Adulto , Tolerância a Medicamentos , Feminino , Humanos , Testes Intradérmicos , Masculino , Pessoa de Meia-Idade , Testes Cutâneos
10.
Allergy ; 51(5): 337-9, 1996 May.
Artigo em Inglês | MEDLINE | ID: mdl-8836339

RESUMO

This report deals with clinical and immunologic studies in a butcher with work-related asthma. Both the positive methacholine inhalation test and the significant changes observed in PEFR measurements supported the diagnosis of asthma. The significant fall observed in PEFR measurements when the patient handled aniseed supported the diagnosis of occupational asthma. Skin prick tests carried out with 13 spices showed positive reactions only to aniseed extract. The patient had high levels of specific antianiseed IgE antibodies. The bronchial challenge test with an aniseed extract showed an immediate response without a late response. These findings suggest that the respiratory symptoms in our patient were induced by the inhalation of aniseed dust through an IgE-mediated immunologic mechanism of immediate hypersensitivity. This study established the diagnosis of occupational asthma from aniseed dust sensitization.


Assuntos
Asma/etiologia , Doenças Profissionais/etiologia , Especiarias/efeitos adversos , Adulto , Asma/fisiopatologia , Testes de Provocação Brônquica , Poeira/efeitos adversos , Humanos , Testes Intradérmicos , Masculino , Doenças Profissionais/fisiopatologia , Teste de Radioalergoadsorção , Sementes/imunologia
11.
Curr Microbiol ; 30(3): 177-82, 1995 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-7765851

RESUMO

The effect of exposure of bacterial suspensions to UV radiation by means of the dose-response curves was assessed. The D37 and D10 values were used for subsequent statistical analysis of the results. The aim of this article is to evaluate the sensitivity to UV radiation of several microorganisms of different habitats (Rhizobium meliloti, Rhodobacter sphaeroides, Escherichia coli, and Deinococcus radiodurans), two mutants with nonfunctional SOS DNA repair system (R. meliloti recA- and E. coli recA-), and a mutant in the synthesis of carotenoids (R. sphaeroides crtD). The results reveal that D. radiodurans was an extremely resistant bacterium, R. meliloti was more resistant than R. sphaeroides, and E. coli was the most sensitive bacterium tested. The high sensitivity of recA- mutants was also verify. Moreover, it seems that the possession of pigments had no important effect in the sensitivity of R. sphaeroides to UV radiation.


Assuntos
Escherichia coli/efeitos da radiação , Rhodobacter sphaeroides/efeitos da radiação , Sinorhizobium meliloti/efeitos da radiação , Raios Ultravioleta , Escherichia coli/crescimento & desenvolvimento , Testes de Sensibilidade Microbiana , Rhodobacter sphaeroides/crescimento & desenvolvimento , Sinorhizobium meliloti/crescimento & desenvolvimento
12.
Allergy ; 58(11): 1152-6, 2003 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-14616126

RESUMO

BACKGROUND: Salsola kali (Russian thistle) is a weed which belongs to the Chaenopodiacea family. It is widely distributed along the coasts of Europe, North Africa, USA and Australia. The objectives of this study were to study the allergenic composition of S. kali pollen and to purify an important allergen from the pollen extracts of this plant. METHODS: A population of 66 individuals with specific IgE-mediated allergic symptoms and positive skin tests to S. kali were included in the study. Specific IgE to S. kali was determined by direct enzyme-linked immunosorbent assay (ELISA). The antigenic and allergenic profile of S. kali was evaluated by sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE), isoelectric focussing (IEF) and immunoblot. Allergen purification was conducted by preparative SDS-PAGE. The allergenicity of the protein was evaluated by skin testing, direct ELISA, ELISA inhibition and immunoblots. RESULTS: Specific IgE to S. kali was detected in 39 of the 66 individuals (59%). An allergen with a molecular weight of approximately 43 kDa was purified. This allergen was termed Sal k 1. A partial sequencing was obtained and no homology was found with other known proteins/allergens. The allergenicity of Sal k 1 was tested in vitro and in vivo. Of the 39 individuals with a positive specific IgE determination to S. kali, 26 (66.6%) had detectable specific IgE to Sal k 1. Twenty of these 39 individuals were skin-prick tested with the purified allergen (0.5 mg/ml) and all of them had a positive skin test to the purified allergen. Ten additional individuals, used as negative controls, had a negative response. CONCLUSIONS: Sal k 1, an important allergen of S. kali, is recognized, in vitro, by approximately 67% of the patients sensitized to S. kali. Twenty patients with a positive skin test to a standardized S. kali extract had a positive reaction to the purified allergen.


Assuntos
Alérgenos/imunologia , Pólen/imunologia , Salsola/imunologia , Alérgenos/química , Alérgenos/isolamento & purificação , Sequência de Aminoácidos , Eletroforese em Gel de Poliacrilamida , Ensaio de Imunoadsorção Enzimática , Humanos , Immunoblotting , Imunoglobulina E/sangue , Focalização Isoelétrica , Pólen/química , Hipersensibilidade Respiratória/imunologia , Salsola/química , Testes Cutâneos
13.
Allergy ; 47(4 Pt 2): 439-40, 1992 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-1456417

RESUMO

We describe 2 cases of paediatric patients who developed the main clinical features of a serum sickness reaction, while on treatment with cefaclor. A decrease in complement values was observed in both cases. Physicians should be aware of the possibility of such drug adverse reaction.


Assuntos
Cefaclor/efeitos adversos , Doença do Soro/induzido quimicamente , Pré-Escolar , Humanos , Lactente , Masculino , Otite Média/tratamento farmacológico , Infecções Respiratórias/tratamento farmacológico , Síndrome
14.
J Allergy Clin Immunol ; 89(4): 884-94, 1992 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-1373162

RESUMO

Several monoclonal antibodies (MAbs) were raised against Olea europaea pollen-extract components. Two of these antibodies, named OL 2 and OL 7, recognize two nonoverlapping, nonrepeating epitopes on the olive-allergen Ole e I, as demonstrated by different techniques. The allergen was purified in a single step by MAb-based affinity chromatography, and the allergen revealed a band at molecular weight 20 kd as well as a minor band at 18 kd on sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The contribution of allergen Ole e I to the allergenic activity of O. europaea pollen extracts was determined from the effect of allergen depletion by affinity chromatography on skin reactivity and a histamine-release test. The removal of allergen caused a large reduction in the activity of the preparation in 25 monospecific olive-allergic patients. In agreement, the affinity-purified allergen demonstrated a similar response when it was compared with the whole extract in these assays. The results indicated that Ole e I is by far the most important olive-pollen allergen. A two-site solid-phase radioimmunoassay was developed for the quantitation of the allergen Ole e I in mass units. The assay was based on the MAbs, OL 2 and OL 7, and had a detection limit in the nanogram range. A good correlation was found between allergenic activity, as determined by RAST inhibition, and allergen content in 18 olive-pollen extracts. This result indicates that the assay can be a good alternative to RAST inhibition for the standardization of O. europaea extracts.


Assuntos
Alérgenos/imunologia , Anticorpos Monoclonais/imunologia , Pólen/imunologia , Alérgenos/isolamento & purificação , Animais , Afinidade de Anticorpos , Especificidade de Anticorpos , Cromatografia de Afinidade , Feminino , Liberação de Histamina , Camundongos , Camundongos Endogâmicos BALB C , Extratos Vegetais/imunologia , Teste de Radioalergoadsorção , Árvores
15.
Clin Exp Allergy ; 23(12): 996-1001, 1993 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-10779292

RESUMO

Type I hypersensitivity to pistachio nut antigens was demonstrated in three patients by means of immediate skin-test reactivity, specific IgE determination by a fluoroimmunoassay (CAP), CAP-inhibition and leucocyte histamine release. Sensitization to other dried fruits and pollens was observed in the patients. The CAP-inhibition studies revealed significant crossreactivity between pistachio and cashew nut belonging to the Anacardiaceae family, and between pistachio nut and other dried fruits belonging to taxonomically unrelated botanical families. No relevant crossallergenicity was observed between pistachio nut and Lolium and Olea pollens. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) of a pistachio nut extract followed by immunoblotting analysis identified four IgE-binding bands with molecular weights of 34, 41, 52 and 60 kD.


Assuntos
Alérgenos/isolamento & purificação , Hipersensibilidade Alimentar/etiologia , Nozes/efeitos adversos , Proteínas de Plantas/isolamento & purificação , Alérgenos/efeitos adversos , Alérgenos/imunologia , Angioedema/etiologia , Reações Cruzadas , Feminino , Hipersensibilidade Alimentar/sangue , Liberação de Histamina/efeitos dos fármacos , Humanos , Imunoglobulina E/sangue , Masculino , Pessoa de Meia-Idade , Nozes/química , Extratos Vegetais/efeitos adversos , Proteínas de Plantas/efeitos adversos , Proteínas de Plantas/imunologia , Testes Cutâneos , Especificidade da Espécie , Árvores/classificação , Urticária/etiologia
16.
Allergy ; 48(4): 296-7, 1993 May.
Artigo em Inglês | MEDLINE | ID: mdl-8328667

RESUMO

A case of fixed eruption caused by ciprofloxacin is reported. To our knowledge, no other cases have been published. Cross-sensitivity with another fluoroquinolone has been demonstrated.


Assuntos
Ciprofloxacina/efeitos adversos , Toxidermias/etiologia , Idoso , Toxidermias/diagnóstico , Toxidermias/patologia , Interações Medicamentosas , Feminino , Humanos , Norfloxacino/efeitos adversos , Testes Cutâneos
17.
Ann Allergy ; 70(4): 324-7, 1993 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-7682042

RESUMO

Vegetable-induced asthma is an uncommon hazard. We report an atopic housewife, in whom rhinoconjunctivitis and acute asthma were associated with two vegetables of taxonomically unrelated botanical families (Swiss chard/Chenopodiaceae family and green beans/legume family). Type I hypersensitivity to the antigens in Swiss chard and green beans was demonstrated by means of skin tests, histamine release test, and specific IgE determination by RAST. Bronchial responses after specific bronchial challenges indicated that Swiss chard and green beans might be the causative factor for the acute asthma.


Assuntos
Asma/etiologia , Fabaceae/efeitos adversos , Hipersensibilidade Alimentar/etiologia , Plantas Medicinais , Verduras/efeitos adversos , Anticorpos/imunologia , Asma/imunologia , Testes de Provocação Brônquica , Feminino , Hipersensibilidade Alimentar/imunologia , Volume Expiratório Forçado , Liberação de Histamina , Humanos , Imunoglobulina E/análise , Leucócitos/metabolismo , Cloreto de Metacolina , Pessoa de Meia-Idade , Pico do Fluxo Expiratório , Testes Cutâneos
18.
Allergy ; 49(2): 92-5, 1994 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-7513507

RESUMO

We report the case of an atopic housewife who presented with rhinoconjunctivitis-asthma and contact urticaria from handling rice and other cereals. She tolerated cooke cereals. Both skin prick tests with a rice extract (20% w/v) and a rub test with raw rice gave positive results. Bronchial challenge test with methacholine revealed a PC20 of 0.45 mg/ml. The challenge test with raw rice resulted in immediate and late clinical and spirometric responses; pretreatment with DSCG inhibited both responses. The histamine release test (HRT) with rice was positive, and we detected rice-specific IgE antibodies by REIA in the patient's serum. Skin prick tests, HRT, and RAST with a battery of cereals gave positive results. Finally, the rice REIA was inhibited by rice (75%), rye (63%), corn (64%), and wheat (51%) extracts.


Assuntos
Asma/etiologia , Hipersensibilidade Imediata/etiologia , Oryza/efeitos adversos , Urticária/etiologia , Adulto , Asma/diagnóstico , Testes de Provocação Brônquica , Conjuntivite Alérgica/etiologia , Feminino , Liberação de Histamina , Humanos , Hipersensibilidade Imediata/diagnóstico , Imunoglobulina E/análise , Rinite Alérgica Perene/etiologia , Testes Cutâneos , Urticária/diagnóstico
19.
Hum Biol ; 69(3): 295-311, 1997 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-9164042

RESUMO

After an intensive bibliographic search, we compiled all the available data on allele frequencies for classical genetic polymorphisms referring to North African populations and synthesized the data in an attempt to reconstruct the populations' demographic history using two complementary methods: (1) principal components analysis and (2) genetic distances represented by neighbor-joining trees. In both analyses the main feature of the genetic landscape in northern Africa is an east-west pattern of variation pointing to the differentiation between the Berber and Arab population groups of the northwest and the populations of Libya and Egypt. Moreover, Libya and Egypt show the smallest genetic distances with the European populations, including the Iberian Peninsula. The most plausible interpretation of these results is that, although demic diffusion during the Neolithic could explain the genetic similarity between northeast Africa and Europe by a parallel process of gene flow from the Near East, a Mesolithic (or older) differentiation of the populations in the northwestern regions with later limited gene flow is needed to understand the genetic picture. The most isolated groups (Mauritanians, Tuaregs, and south Algerian Berbers) were the most differentiated and, although no clear structure can be discerned among the different Arab- and Berber-speaking groups, Arab speakers as a whole are closer to Egyptians and Libyans. By contrast, the genetic contribution of sub-Saharan Africa appears to be small.


PIP: An extensive bibliographic search was conducted to compile all available data on allele frequencies for classical genetic polymorphisms referring to North African populations. The data were then synthesized to reconstruct the population's demographic history using principal components analysis and genetic distances represented by neighbor-joining trees. Both analyses identified an east-west pattern of genetic variation in northern Africa pointing to the differentiation between the Berber and Arab population groups of the northwest and the populations of Libya and Egypt. Libya and Egypt are also the smallest genetic distances away from European populations. Demic diffusion during the Neolithic period could explain the genetic similarity between northeast Africa and Europe through a parallel process of gene flow from the Near East, but a Mesolithic or older differentiation of the populations into the northwestern regions with later limited gene flow is needed to understand this genetic picture. Mauritanians, Tuaregs, and south Algerian Berbers, the most isolated groups, were the most differentiated, while Arab speakers overall are closer to Egyptians and Libyans. The genetic contribution of sub-Saharan Africa appears to be small.


Assuntos
Emigração e Imigração , Frequência do Gene/genética , Marcadores Genéticos/genética , Polimorfismo Genético/genética , África do Norte , Demografia , Análise Fatorial , Pool Gênico , Humanos , Mauritânia
20.
Int J Legal Med ; 109(3): 159-60, 1996.
Artigo em Inglês | MEDLINE | ID: mdl-8956994

RESUMO

An allele heterogeneity in a short tandem repeat at the human dihydrofolate reductase pseudogene (DHFRP2) was detected using non-denaturing gel electrophoresis and ethidium bromide staining. Sequence analysis of the allele, designated 9A, revealed the C to A substitution in the 8th AAAC repeat. A survey of 16 worldwide human populations showed that this mutation was spread through five continents at a relatively high frequency (up to p = 0.19 in Europeans). Some statistical parameters of forensic interest were also calculated (h, PD, EC and PIC) for this polymorphism. This type of heterogeneity stresses the complexity of STR variation.


Assuntos
Frequência do Gene , Repetições de Microssatélites/genética , Mutação Puntual , Pseudogenes/genética , Tetra-Hidrofolato Desidrogenase/genética , Alelos , Humanos
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