RESUMO
Each of the two mutants isolated from a fliC (= hag, flagellin-deficient) Escherichia coli strain made motile by a plasmid carrying the fliC gene of Salmonella muenchen by selection for motility in the presence of anti-d (Salmonella flagellar antigen) serum had both lost and gained one or more subfactors of the wild-type antigen. In one mutant codon 246 was GAC (alanine) instead of GCC (asparagine); the other had a deletion of 105 base pairs, explicable by a 10bp direct repeat, starting at bases 782 and 887. The in vitro removal of a 48bp EcoRV(631)/EcoRV(679) fragment produced plasmid pLS408, which was found to lack a subfactor of wild-type antigen d but able to confer motility on flagellin-negative Salmonella sp. (and used for insertion of epitope-specifying oligonucleotides at its EcoRV site). Immunoblotting with absorbed and unabsorbed sera from rabbits immunized with E. coli with wild-type or mutated antigen d showed that the fusion proteins specified by lambda gt11 with the N-terminal part of gene lacZ joined to a restriction fragment coding for residues 145-391 of flagellin gave the same pattern of parent-specific and mutant-specific reactions as the flagellate bacteria. Four out of five similarly selected mutants had the same 105 bp deletion as the first-isolated mutant; the fifth had a 72 bp deletion made possible by a 7-base pair direct repeat, starting at positions 649 and 721. All these changes in serological character without loss of function affected segment IV, specifying residues 182 to 308 of the total of 505, where there is little homology between different flagellar-antigen alleles.
Assuntos
Antígenos de Bactérias/genética , Epitopos/genética , Flagelos/imunologia , Flagelina/genética , Salmonella/genética , Antígenos de Bactérias/imunologia , Western Blotting , Clonagem Molecular , Epitopos/imunologia , Flagelina/imunologia , Mutação , Plasmídeos , Mapeamento por Restrição , Salmonella/imunologiaRESUMO
A male infant with complete hereditary deficiency of hepatic ornithine transcarbamylase was fed a low-protein diet (1 gm/kg/day) supplemented with nitrogen-free analogues of essential amino acids from the age of 2 days until his death at 5 months. Blood ammonia and plasma acid concentrations were maintained in the near normal range during most of his lifetime. Growth and development were entirely normal. Abrupt, unprecipitated hyperammonemia, which could not be reversed by intensive treatment, led to his death. To our knowledge, this child lived longer than any previously reported infant with OTC deficiency of this severity.
Assuntos
Aminoácidos Essenciais/uso terapêutico , Doença da Deficiência de Ornitina Carbomoiltransferase , Aminoácidos/sangue , Amônia/sangue , Desenvolvimento Infantil , Proteínas Alimentares , Ingestão de Energia , Crescimento , Humanos , Lactente , Recém-Nascido , Masculino , Nitrogênio/metabolismo , Ácido Orótico/metabolismoAssuntos
Anormalidades Induzidas por Medicamentos/etiologia , Hidantoínas/efeitos adversos , Teratogênicos , Epilepsia/tratamento farmacológico , Feminino , Transtornos do Crescimento/induzido quimicamente , Humanos , Hidantoínas/uso terapêutico , Deficiência Intelectual/induzido quimicamente , Troca Materno-Fetal , Gravidez , Complicações na GravidezRESUMO
The genetic knowledge of parents of children with congenital heart disease, who had received genetic counseling, was compared with that of a control noncounseled group attending the same cardiac clinic. A follow-up questionnaire showed that both groups had excellent knowledge of the nature of their children's heart lesions. The counseled group had significantly more accurate knowledge of their recurrence risks. Inasmuch as the reproductive attitudes of some of these parents were found to be influenced by genetic information, parents of children with CHD should be given a better understanding of recurrence risks for CHD than many of them possess.
PIP: Parents of a group of children with congenital heart disease attendi ng the Yale-New Haven Pediatric Clinic were given genetic counseling which included an explanation of the genetic basis for their child's cardiac lesion and the risk of probable recurrence. This group was questioned 6 months later and compared to a control group of parents which did not receive the genetic counseling lecture. There was a highly significant (at the p less than .005 level) difference in genetic knowledge and knowledge of recurrence risk between the counseled and the control group. This type of counseling is recommended for parents of children with congenital heart disease.