Assuntos
Trigêmeos/genética , Adulto , Chile , Bandeamento Cromossômico , Feminino , Humanos , Masculino , FenótipoRESUMO
Premature ovarian failure is defined as the occurrence of menopause before the age of 40 years. Etiology has been related to genetic, autoimmune or infectious factors, resistance to gonadotropins and others. Forty-seven patients with this diagnosis were referred for cytogenetic analysis. Sixty-eight percent of the cases had a normal karyotype. In 10.7% there was one 45,X cell and they were catalogued as normal. In 15% of the patients there was a mosaicism with normal cell lines and additional 45,X, 47,XXXX and 48,XXXX ones. Two women had a chromosomal constitution 47,XXX. In one 22-year old patient there was a reciprocal balanced translocation 46,X t(X; 18) (q21.2;q22). The presence of different cell lines, including 45,X cells, could explain an accelerated loss of gametes in the ovary. In women with 47,XXX karyotype, fertility problems and premature menopause have been described. The study of the balanced X-autosome translocation with DNA technics could allow to find the molecular basis of the ovarian failure, permitting the direct search of the gene involved at the site of disruption.
Assuntos
Insuficiência Ovariana Primária/genética , Adolescente , Adulto , Feminino , Humanos , Cariotipagem , Menopausa Precoce/genética , Mosaicismo , Linhagem , Insuficiência Ovariana Primária/diagnóstico , Cromossomo XRESUMO
Among 257 patients with clinical diagnosis of Down's syndrome, 56.4% of male gender, in whom cytogenetic studies were performed, 14 (5.4%) had normal karyotypes and 243 (94.6%) had 21 trisomy. Of these last, 225 (92.6%) had free 21 trisomy, 10 (4.1%) showed mosaics, 8 (3.3%) had translocations. Average maternal age of this sample was significantly higher than that of patients attending the same maternity wards (32.14 vs. 24.85 years) and 41% of Down syndrome's patients came from mothers aged 36 years or more, even though only 9.7% of this country's deliveries proceed from women of that age group. As to seasonal occurrence, the proportions of births which happened in summer almost doubled that of winter (33.1% vs. 16.9%). The frequency of characteristic clinical signs of Down's syndrome was somewhat different than that described for patients from some other countries, for instance: epicanthus, short neck and widening of the space between 1st. and 2nd. toe were more frequent, while Brushfield's spots, depressed occiput, dental anomalies, heart malformations and fissured tongue seemed less frequent. The importance of cytogenetic studies for diagnosis and genetic counseling is stressed.
Assuntos
Síndrome de Down/genética , Chile/epidemiologia , Citogenética , Síndrome de Down/epidemiologia , Feminino , Humanos , Masculino , Idade Materna , Mosaicismo , Estações do Ano , Translocação GenéticaRESUMO
Cytogenetic study in couples with recurrent reproductive failure allows the detection of structural chromosome anomalies which don't have a phenotypic effect in carriers, but permit the explanation of the production of genetically unbalanced gametes. We present the investigation performed in 270 couples which demonstrated a chromosomal alteration in 9.2% of them. This allows genetic counselling in respect of the importance of the finding, recurrence risk and reproductive alternatives. In 8.6% we found some cellular lines with aneuploidies in sexual chromosomes, which don't represent a such concrete risk.
Assuntos
Aberrações Cromossômicas/genética , Infertilidade Feminina/diagnóstico , Infertilidade Masculina/diagnóstico , Adulto , Citogenética , Feminino , Humanos , Infertilidade Feminina/genética , Infertilidade Masculina/genética , Masculino , Mosaicismo/genética , Translocação Genética/genéticaRESUMO
During the period june 1987-January 1988, 35 consecutive pairs of twins born at two maternity hospitals in the northern area of Santiago were studied to search evidence of genetic or other factors which could eventually favour twinning. Sixteen of these pairs were considered to be monozygotic (MZ) after studying five blood group systems (ABO, Rh, MNSs, Duffy and Kidd) applying the method of Smith and Penrose. Maternal age was higher in dizygotic twins (DZ) than in the MZ group (average 30.1 yrs. v/s 26.8 yrs. respectively (p < 0.05). Family history of twinning was positive in 73% of the MZ and in 82% of the DZ twins. The Duffy and Kidd systems were not in Hardy-Weinberg equilibrium due to a deficit of heterozygotes in MZ as well as in DZ twins. There was a significant increase in MS and Ms haplotypes in both groups of twins respect to the Chilean general population (p = 0.01). These results suggest the presence of a genetic determinant that favors the production of twinning of DZ as well as MZ type. A larger number of cases will be required to test this hypothesis.
Assuntos
Variação Genética , Gêmeos Dizigóticos/genética , Gêmeos Monozigóticos/genética , Antígenos de Grupos Sanguíneos , Chile , Feminino , Humanos , Recém-Nascido , Masculino , Idade Materna , Fenótipo , Estudos ProspectivosRESUMO
From 1983 to 1987 we studied 30 patients with leukemia searching for chromosomal alterations. Cytogenetic studies of bone marrow showed an abnormal karyotype in 19 (67%). Seven out of 14 cases of acute leukemia presented different chromosomic alterations. The Philadelphia chromosome was found in 11 patients with chronic myeloid leukemia and 3 patients with chronic lymphatic leukemia; a Pseudo-Philadelphia chromosome was present in one patient, this being the first such finding in Chile. Thus, the karyotype is a valuable complementary study not only in chronic myeloid leukemia but also in chronic lymphatic leukemia and the acute lymphoblastic and non-lymphoblastic varieties.
Assuntos
Aberrações Cromossômicas/genética , Leucemia Mielogênica Crônica BCR-ABL Positiva/genética , Leucemia-Linfoma Linfoblástico de Células Precursoras/genética , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Feminino , Humanos , Cariotipagem , Leucemia Mielogênica Crônica BCR-ABL Positiva/tratamento farmacológico , Masculino , Pessoa de Meia-Idade , Cromossomo Filadélfia , Leucemia-Linfoma Linfoblástico de Células Precursoras/tratamento farmacológicoAssuntos
Aberrações Cromossômicas/epidemiologia , Adolescente , Adulto , Criança , Pré-Escolar , Chile , Aberrações Cromossômicas/genética , Transtornos Cromossômicos , Mapeamento Cromossômico , Estudos Transversais , Feminino , Humanos , Lactente , Recém-Nascido , Cariotipagem , Masculino , Aberrações dos Cromossomos Sexuais/genéticaRESUMO
Immunogenicity of Plasmodium gallinaceum sporozoites for chicks and their in vitro reactivity with normal and specific immune sera were studied. Two sporozoite populations recovered from experimentally infected Aedes fluviatilis were used: sporozoites from salivary glands and sporozoites from midgut oocysts. Populations seven to nine days old of sporozoites recovered from salivary glands were infective for all chicks until the chicks were three weeks old; however, sporozoites recovered from midguts containing oocysts infected these chicks only if isolated on days 8-9, but not on day 7 after the mosquitoes' infective blood meal. Infectivity of the sporozoites was lost after exposure to ultraviolet (UV) light (30 min) or X-rays (13 krad). Inactivated sporozoites from both sources proved highly immunogenic to chicks that were immunized by several intravenous or intramuscular injections. These parasites elicited a strong humoral immune response in the chicks, as measured by the circumsporozoite precipitation (CSP) reaction. The levels of the CSP antibodies were similar with sporozoites from both sources, there being no detectable differences in the percentage of reactive sporozoites or the intensity of the CSP reaction with sera containing antibodies to either sporozoites from salivary glands or sporozoites from oocysts. These results provide the first evidence that avian malaria sporozoites express the circumsporozoite protein that has been extensively characterized in mammalian malaria (rodent, simian, human sporozoites). Furthermore, we observed that the yields of sporozoites obtained from mosquito midguts, on days 8 and 9 of the P. gallinaceum infection, were at least twice as great as those obtained by salivary gland dissection, even 20 days after a blood meal.(ABSTRACT TRUNCATED AT 250 WORDS)
Assuntos
Aedes/parasitologia , Antígenos de Protozoários/imunologia , Galinhas/parasitologia , Malária Aviária/parasitologia , Plasmodium gallinaceum/imunologia , Plasmodium/imunologia , Proteínas de Protozoários , Animais , Anticorpos Antiprotozoários/biossíntese , Antígenos de Protozoários/análise , Antígenos de Superfície/análise , Antígenos de Superfície/imunologia , Malária Aviária/imunologia , Plasmodium gallinaceum/crescimento & desenvolvimento , Plasmodium gallinaceum/efeitos da radiação , Vacinação/veterináriaRESUMO
Se realizó estudio citogenético de médula ósea en 25 pacientes con alteraciones hematológicas malignas o premalignas. En 22 pacientes se obtuvo células en mitosis para análisis cromosómico (88%). En 10 pacientes (40%) se observó un cariotipo alterado en algún momento de su evolución. La alteración cromosómica más frecuente fue la presencia de un cromosoma Philadelphia (Ph') en seis pacientes, cinco de los cuales tenían un diagnóstico de leucemia mieloide crónica (LMC). El resto de los pacientes con cariotipo alterado tenía un diagnóstico de preleucemia. Dos de ellos tenían células poliploides, en uno se encontró cromosomas marcadores y en otro, un cromosoma 22q+