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1.
Int J STD AIDS ; 20(7): 473-6, 2009 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-19541889

RESUMO

The objective of the study was to investigate the HIV-mother-to-child transmission (MTCT) rate in Israel. This was a retrospective study of HIV-infected pregnant women, mainly immigrants from Ethiopia, in six Israeli AIDS centres, in 2000-2005. Medical records of mothers and newborns were evaluated for HIV status, treatment and MTCT rates. Three hundred pregnancies of 241 HIV-infected women, resulting in 304 live births, were studied. In 86/241(36%) women, HIV diagnosis was made during the current pregnancy or shortly after labour. Thirty others were diagnosed during previous pregnancies. Highly active antiretroviral therapy (HAART) was prescribed in 76% of pregnancies. The mean viral load before labour was 23,000 +/- 100,000 copies/mL with a mean CD4 of 406 +/- 223 (range 4-1277) cells/mm(3). Caesarian sections were preformed in 175/300 pregnancies (103/175 with viral load <1000 copies/mL). During labour, azidothymidine (AZT) was given to 80% and nevirapine to 8% of the women. Eighty-eight percent of the neonates received AZT for six weeks. The overall HIV-MTCT rate was 3.6%. MTCT correlated significantly with delayed HIV diagnosis, low CD4, lack of HAART during pregnancy and lack of perinatal treatment. HIV treatment of mothers and their newborns throughout pregnancy, labour and perinatal period are crucial for effective prevention of MTCT, emphasizing the need for early HIV screening, diagnosis and treatment.


Assuntos
Terapia Antirretroviral de Alta Atividade , Infecções por HIV , Transmissão Vertical de Doenças Infecciosas/prevenção & controle , Transmissão Vertical de Doenças Infecciosas/estatística & dados numéricos , Complicações Infecciosas na Gravidez/tratamento farmacológico , Adolescente , Adulto , Fármacos Anti-HIV/uso terapêutico , Emigrantes e Imigrantes , Etiópia , Feminino , Infecções por HIV/epidemiologia , Infecções por HIV/prevenção & controle , Infecções por HIV/transmissão , Infecções por HIV/virologia , Humanos , Recém-Nascido , Israel/epidemiologia , Pessoa de Meia-Idade , Programas Nacionais de Saúde , Nevirapina/uso terapêutico , Gravidez , Complicações Infecciosas na Gravidez/epidemiologia , Complicações Infecciosas na Gravidez/virologia , Avaliação de Programas e Projetos de Saúde , Inibidores da Transcriptase Reversa/uso terapêutico , Carga Viral , Adulto Jovem , Zidovudina/uso terapêutico
2.
J Inherit Metab Dis ; 30(2): 165-74, 2007 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-17347914

RESUMO

Mucopolysaccharidosis IVA (MPS IVA; Morquio A disease) is a lysosomal storage disorder caused by deficiency of N-acetylgalactosamine-6-sulfate sulfatase. The natural history of this disease is incompletely understood. To study which variables influence the clinical outcome, we conducted a study in which MPS IVA patients were asked to fill out a questionnaire with inquiries regarding family history, diagnosis, signs and symptoms, height, weight, surgical history, physical activity, and general complaints. A total of 326 patients (172 male, 154 female) from 42 countries enrolled in the Morquio A Registry programme. The mean age of patients enrolled was 14.9 years for males and 19.1 years for females, with a wide range of 1-73 years. Sixty-four per cent of the patients were under 18 years. Initial symptoms were recognized between 1 and 3 years of age (mean age 2.1 years) and mean age at diagnosis for the patients was 4.7 years. A progressive skeletal dysplasia was commonly observed among the MPS IVA patients. Fifty per cent of patients underwent surgical operations to improve their quality of life. The most frequent surgical sites include neck (51%), ear (33%), leg (26%) and hip (25%). The birth length for affected males and females was 52.2 +/- 4.7 cm and 52.2 +/- 4.5 cm, respectively. The final adult height for affected males and females was 122.5 +/- 22.5 cm and 116.5 +/- 20.5 cm, respectively. The results of this study provide a reference for assessment of efficacy for studies of novel therapies.


Assuntos
Internacionalidade , Mucopolissacaridose IV/fisiopatologia , Sistema de Registros , Adolescente , Adulto , Idade de Início , Idoso , Estatura , Peso Corporal , Criança , Pré-Escolar , Progressão da Doença , Feminino , Humanos , Lactente , Masculino , Prontuários Médicos , Pessoa de Meia-Idade , Atividade Motora , Mucopolissacaridose IV/epidemiologia , Mucopolissacaridose IV/genética , Mucopolissacaridose IV/cirurgia , Fenótipo
3.
Arch Dis Child ; 88(10): 940-2, 2003 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-14500320

RESUMO

Two cases of atypical Kawasaki disease (KD) manifested as persistent lobar lung consolidation, prolonged fever, and active inflammatory laboratory markers unresponsive to antibiotic treatment are reported. One of the children developed a giant coronary aneurysm. Atypical KD should be considered in the differential diagnosis of young children with prolonged fever and lobar consolidation unresponsive to antibiotics.


Assuntos
Síndrome de Linfonodos Mucocutâneos/complicações , Pneumonia/etiologia , Aneurisma Coronário/etiologia , Feminino , Seguimentos , Humanos , Lactente , Masculino , Síndrome de Linfonodos Mucocutâneos/diagnóstico , Pneumonia/diagnóstico por imagem , Radiografia
4.
Pediatrics ; 108(6): E113, 2001 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-11731640

RESUMO

A 4-year-old Jewish boy presented with dysuria, urinary dribbling, increased urinary frequency, and new onset of diurnal enuresis. An infiltrating solid mass involving the entire bladder wall was found. Biopsy revealed "tumor-forming" eosinophilic cystitis, a rare bladder lesion of unclear cause. Antitoxocariasis treatment was unsuccessful. High-dose corticosteroids failed. The child's clinical condition and bladder sonographic findings continued to deteriorate. Treatment with cyclosporin A was given for 8 months, with a complete clinical, radiologic, and histopathologic cure and no side effects. Two years of follow-up showed a complete recovery.


Assuntos
Ciclosporina/uso terapêutico , Cistite/tratamento farmacológico , Eosinofilia/tratamento farmacológico , Imunossupressores/uso terapêutico , Pré-Escolar , Cistite/diagnóstico , Cistite/imunologia , Eosinofilia/diagnóstico , Humanos , Masculino
5.
AIDS ; 15(12): 1453-60, 2001 Aug 17.
Artigo em Inglês | MEDLINE | ID: mdl-11504976

RESUMO

OBJECTIVE: To compare drug-resistant variants from untreated (naive) and treated patients infected with clade B or C virus. METHODS: Consecutive samples (165) from patients throughout Israel were analyzed. All those in the treated group were failing highly active antiretroviral therapy. RESULTS: There were 87 clade B (14 naive) and 78 clade C (20 naive) [corrected] with significant differences in the prevalence of known drug-resistance mutations between the clades: in naive patients in the protease region M36I 7% and 95% (P < 0.0001), K20R 0% and 27% (P = 0.063), A71V 18% and 0% (P = 0.063), M46I 0% and 13%, and V77I 18% and 0% (P = 0.063), respectively, and in the reverse transcriptase region A98G/S 0% and 20% (P = 0.12), respectively. Most clade C viruses also showed significant differences from clade B consensus sequence at additional protease sites: R41K 100%, H69K/Q 85%, L89M 95% and I93L 80% (P < 0.0001). There were also significant differences (P < 0.03 to < 0.0001) in treated patients in clades B and C: in the protease region L10I 40% and 12%, M36I 26% and 95%, L63P 67% and 40%, A71I 38% and 7%, G73I and V77I 18% and 0%, I84V 16% and 3%, and L90M 40% and 12%, respectively; in the reverse transcriptase M41L 41% and 17%, D67N 41% and12%, K70R 30% and 7%, T215Y 48% and 29%, K219Q 21% and 7%, and A98G/S 3% and 24%, respectively. CONCLUSION: Significantly differences between clade B and C viruses may be associated with development of differing resistance patterns during therapy and may affect drug utility in patients infected with clade C.


Assuntos
Variação Genética , Infecções por HIV/virologia , Protease de HIV/genética , Transcriptase Reversa do HIV/genética , HIV-1/enzimologia , Adolescente , Adulto , Idoso , Fármacos Anti-HIV/farmacologia , Fármacos Anti-HIV/uso terapêutico , Criança , Pré-Escolar , Resistência Microbiana a Medicamentos/genética , Quimioterapia Combinada , Feminino , Genótipo , Infecções por HIV/tratamento farmacológico , Infecções por HIV/epidemiologia , HIV-1/classificação , HIV-1/efeitos dos fármacos , HIV-1/genética , Humanos , Masculino , Pessoa de Meia-Idade , Mutação , Polimorfismo Genético , Inibidores da Transcriptase Reversa/farmacologia , Inibidores da Transcriptase Reversa/uso terapêutico
6.
J Bone Miner Res ; 16(12): 2245-50, 2001 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-11760838

RESUMO

Spondyloepiphyseal dysplasia tarda (SEDT), an X-linked recessive skeletal disorder, presents with disproportionate short stature and "barrel-chest" deformity in affected (hemizygous) adolescent boys. In four reported families to date, mutations in a gene designated SEDL (spondyloepiphyseal dysplasia late) cosegregate with SEDT. We diagnosed SEDT in a short-stature, kyphotic 15-year-old boy because of his characteristic vertebral malformations. Clinical manifestations of SEDT were evident in at least four previous generations. A novel 2-base pair (bp) deletion in exon 5 of SEDL was found in the propositus by polymerase chain reaction (PCR) amplification and sequencing of all four coding exons. The mutation ATdel241-242 cosegregated with the kindred's skeletal disease. The deletion is adjacent to a noncanonical splice site for exon 5 but does not alter splicing. Instead, it deletes 2 bp from the coding sequence, causing a frameshift. A maternal aunt and her three young sons were investigated subsequently. Radiographs showed subtle shaping abnormalities of her pelvis and knees, suggesting heterozygosity. X-rays of the spine and pelvis of her 8-year-old son revealed characteristic changes of SEDT, but her younger sons (aged 6 years and 3 years) showed no abnormalities. SEDL analysis confirmed that she and only her eldest boy had the 2-bp deletion. Molecular testing of SEDL enables carrier detection and definitive diagnosis before clinical or radiographic expression of SEDT. Although there is no specific treatment for SEDT, preexpression molecular testing of SEDL could be helpful if avoiding physical activities potentially injurious to the spine and the joints proves beneficial.


Assuntos
Pareamento de Bases , Proteínas de Transporte/genética , Proteínas de Membrana Transportadoras , Osteocondrodisplasias/genética , Deleção de Sequência , Osteofitose Vertebral/genética , Adolescente , Adulto , Criança , Pré-Escolar , Éxons , Feminino , Humanos , Vértebras Lombares/anormalidades , Vértebras Lombares/diagnóstico por imagem , Masculino , Osteocondrodisplasias/fisiopatologia , Linhagem , RNA Mensageiro , Radiografia , Osteofitose Vertebral/fisiopatologia , Fatores de Transcrição
7.
J Clin Endocrinol Metab ; 85(9): 3343-7, 2000 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-10999831

RESUMO

A six-generation kindred from Arkansas with X-linked recessive spondyloepiphyseal dysplasia tarda (SEDT) was investigated by genetic linkage and mutation analysis. SEDT had been mapped on the X-chromosome (Xp22.2), and the clinical and radiographic evolution of this kindred had been published. Linkage analysis proved informative for all five polymorphic markers tested, and DXS987 and DXS16 co-segregated with the Arkansas kindred (peak logarithm of the odds scores, 3.54 and 3.36, respectively). Subsequently, dinucleotide deletion in a new gene designated "sedlin" was reported to cause SEDT in three families. In an affected man and obligate carrier woman in the Arkansas kindred, we found a 5-bp deletion in exon 5 of sedlin. The defect causes a frameshift, resulting in eight missense amino acids and premature termination. The 5-bp deletion was then demonstrated to segregate with SEDT in the four living generations, including eight affected males and nine obligate carrier females. Furthermore, the deletion was identified in four females who potentially were heterozygous carriers for SEDT. The mutation was not detected in the two young sons of the consultand (believed to be a carrier because of her subtle radiographic skeletal changes and then shown to have the deletion), but they were too young for x-ray diagnosis Identification of a defect in sedlin in this SEDT kindred enables carrier detection and presymptomatic diagnosis and reveals an important role for this gene in postnatal endochondral bone formation.


Assuntos
Proteínas de Transporte/genética , Proteínas de Membrana Transportadoras , Osteocondrodisplasias/genética , Adulto , Cromossomos Humanos Par 22/genética , DNA/análise , DNA/genética , Éxons/genética , Feminino , Ligação Genética/genética , Heterozigoto , Humanos , Masculino , Mutação/genética , Linhagem , Fenótipo , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Deleção de Sequência , Fatores de Transcrição
8.
Am J Med Genet ; 92(2): 132-5, 2000 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-10797438

RESUMO

Individuals with neurofibromatosis 1 (NF1) develop both benign and malignant tumors at an increased frequency. One of the most common benign tumors in NF1 is the plexiform neurofibroma. These tumors cause significant morbidity and mortality on account of their propensity to grow and affect adjacent normal tissues. To determine the clinical profile of plexiform neurofibromas in NF1, we conducted a retrospective review of 68 NF1 patients with plexiform neurofibroma. In our series, 44% of tumors were detected by 5 years of age and most were located in the trunk and extremities. Only two patients developed malignant peripheral nerve sheath tumors in their preexisting plexiform neurofibromas. Lastly, we demonstrate that there were no specific clinical features of NF1 associated with the presence of plexiform neurofibroma. These results underscore the importance of careful serial examinations in the evaluation of patients with NF1.


Assuntos
Neurofibroma Plexiforme/patologia , Neurofibromatose 1/patologia , Adolescente , Adulto , Criança , Pré-Escolar , Estudos de Coortes , Feminino , Humanos , Lactente , Recém-Nascido , Masculino , Prontuários Médicos , Neurofibroma Plexiforme/etiologia , Neurofibromatose 1/complicações , Estudos Retrospectivos
9.
Am J Med Genet ; 90(4): 276-82, 2000 Feb 14.
Artigo em Inglês | MEDLINE | ID: mdl-10710223

RESUMO

We report on the use of fluorescence in situ hybridization (FISH) with specific chromosome 8 arm painting to characterize further small supernumerary chromosome 8-derived markers/rings (SMC/SRC) identified in three patients. Two patients (patients 1 and 2) who carried the marker (SMC) were evaluated because of mental retardation and minor facial anomalies. The patient (patient 3) who carried the ring (SRC) had ventriculomegaly. Parental blood chromosomes of patients 2 and 3 were normal and unavailable on patient 1. The identification of the SMC/SRC was first characterized by FISH specific alpha-repeat centromeric probes, second by FISH whole chromosome painting (WCP), and finally by FISH chromosome arm painting (CAP). The latter showed involvement of only the short arm of chromosome 8 in all three SMC/SRC cases, suggesting a U-type exchange mechanism.


Assuntos
Coloração Cromossômica , Cromossomos Humanos Par 8 , Marcadores Genéticos , Pré-Escolar , Humanos , Hibridização in Situ Fluorescente , Recém-Nascido , Cariotipagem , Masculino
10.
Medicine (Baltimore) ; 78(1): 9-25, 1999 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-9990351

RESUMO

We characterize the clinical and radiographic evolution of X-linked recessive spondyloepiphyseal dysplasia tarda (SEDT) in a 6-generation kindred from Arkansas (SEDT(AK)). Our observations show the natural progression of SEDT(AK) and enable carrier detection by radiographic study. We find that, SEDT(AK) manifests as a postnatal defect. Affected hemizygous males can have radiographically normal vertebrae at birth. The pathogenesis seems to involve a developmental disturbance in endochondral bone formation that is reflected most dramatically in vertebrae by a radiographically inapparent ring apophysis. This defect leads to distinctive malformation of the anterior margins of the lumbar vertebrae during childhood. Subsequently, there is degeneration of intervertebral discs and destruction of spinal facet joints. In the femur, the head, neck, and distal condyles are abnormally shaped and become distorted so that osteoarthritis of the hip is not uncommon. Obligate carrier females heterozygous for the SEDT(AK) gene defect demonstrate several similar but more subtle skeletal abnormalities beginning in early adult life. These women seem to be troubled frequently by arthralgia by middle age. The cumulative findings in SEDT(AK) implicate a defect in a gene at Xp22.2-22.1 that engenders a relatively mild disturbance in endochondral bone formation, especially in the axial skeleton. Accounts of large, well-characterized SEDT kindreds remain essential to appreciate fully any interfamily variability of disease expression and to understand better the pathogenesis of the SEDT defect on the X chromosome.


Assuntos
Genes Recessivos/genética , Ligação Genética/genética , Osteocondrodisplasias/diagnóstico por imagem , Osteocondrodisplasias/genética , Cromossomo X/genética , Adulto , Artralgia/etiologia , Progressão da Doença , Feminino , Triagem de Portadores Genéticos , Heterozigoto , Humanos , Vértebras Lombares/diagnóstico por imagem , Vértebras Lombares/patologia , Masculino , Osteoartrite/etiologia , Osteocondrodisplasias/complicações , Osteocondrodisplasias/patologia , Linhagem , Radiografia
13.
Pediatr Radiol ; 27(5): 436-41, 1997 May.
Artigo em Inglês | MEDLINE | ID: mdl-9133359

RESUMO

Four members of a family - three of whom have facial features mildly resembling those of the trichorhinophalangeal syndrome, type I, and all of whom manifested appendicular bony prominences similar to trichorhinophalangeal syndrome, type II - were found to have the radiographic findings of metachondromatosis. The radiographic manifestations and evolution of metachondromatosis are depicted in this report.


Assuntos
Exostose Múltipla Hereditária/diagnóstico , Síndrome de Langer-Giedion/diagnóstico , Adulto , Criança , Pré-Escolar , Diagnóstico Diferencial , Exostose Múltipla Hereditária/diagnóstico por imagem , Exostose Múltipla Hereditária/genética , Fácies , Feminino , Humanos , Lactente , Masculino , Linhagem , Radiografia
15.
Pediatr Infect Dis J ; 15(7): 610-5, 1996 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-8823856

RESUMO

BACKGROUND: Brucellosis has become a major medical problem in Israel particularly in the Muslim Arab population. METHODS: Eighty-eight children with acute brucellosis are described. Sixty-seven were studied retrospectively during 1987 through 1988, and 21 children were studied prospectively during 1989 through 1992. Epidemiologic, clinical and laboratory features were evaluated, and the outcome of 4 antimicrobial regimens are compared. RESULTS: Although the clinical manifestation varied, the classical triad of fever (91%), arthralgia or arthritis (83%) and hepato- and/or splenomegaly (63%) characterized most patients. Sixty-one percent of the children had elevated liver enzymes. Brucella melitensis was isolated from 61% of blood cultures. The relapse rate in patients who were treated with monotherapy (doxycycline) was 43% compared with 14% with regimens of combined therapy with rifampin and doxycycline, streptomycin and doxycycline or rifampin and trimethoprim-sulfamethoxazole (P < 0.049). Eleven children (33%) who were treated for 3 weeks had relapse compared with 1 patient (3.5%) treated for 4 weeks or longer. The total relapse or reinfection rate was 20%. All patients with relapse recovered after a second course of antibiotic therapy. During the 2 years of follow-up one child progressed to chronic osteomyelitis. CONCLUSIONS: Combination therapy and extending treatment for 4 weeks or longer gave significantly better results than monotherapy or shorter courses of therapy and resulted in fewer relapses.


Assuntos
Brucelose/epidemiologia , Surtos de Doenças , Adolescente , Brucelose/diagnóstico , Brucelose/tratamento farmacológico , Brucelose/fisiopatologia , Criança , Pré-Escolar , Surtos de Doenças/estatística & dados numéricos , Quimioterapia Combinada , Feminino , Humanos , Incidência , Israel/epidemiologia , Masculino , Prognóstico , Estudos Prospectivos , Recidiva , Estudos Retrospectivos , Fatores de Risco , Testes Sorológicos
17.
Eur J Immunol ; 20(9): 2083-7, 1990 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-2209704

RESUMO

It was shown previously that experimental autoimmune diseases could be prevented or treated specifically by administering suitably attenuated autoimmune T lymphocytes to animals, a process termed T cell vaccination (Cohen, I. R., Sci. American 1988. 256: 52). We now report that T cell vaccination is an effective way of inducing tolerance to contact sensitivity to simple chemical haptens. Vaccines were prepared from populations of lymph node cells from specifically sensitized mice by activating the T cells with the T cell mitogen concanavalin A and then treating the T cell blasts with glutaraldehyde. The vaccinated mice showed decreased delayed sensitivity responses to the specific sensitizing antigen and developed significant delayed sensitivity responses to the T cells of the same specificity as those used for vaccination. Thus, T cell vaccination against contact sensitivity reactions appears to function similarly to T cell vaccination against autoimmune disease.


Assuntos
Dermatite de Contato/imunologia , Tolerância Imunológica , Imunoterapia Adotiva , Linfócitos T/imunologia , Vacinação , Animais , Dinitrofluorbenzeno/imunologia , Feminino , Hipersensibilidade Tardia , Idiótipos de Imunoglobulinas/imunologia , Ativação Linfocitária , Camundongos , Camundongos Endogâmicos BALB C , Oxazolona/imunologia
18.
Nucleic Acids Res ; 18(14): 4227-36, 1990 Jul 25.
Artigo em Inglês | MEDLINE | ID: mdl-1696002

RESUMO

We have developed a strategy for the detection, localization and sequence determination of point mutations in the mRNA coding for the alpha 1(I) and alpha 2(I) chains of type I collagen. Point mutations are detected by RNase A cleavage of mismatches in RNA/RNA hybrids. The mRNAs coding for the fibrillar collagens present special problems for hybrid analysis because of their large size and their GC-rich and repetitive sequences. We have generated a series of overlapping antisense riboprobes covering the entire pro alpha 1(I) and pro alpha 2(I) mRNAs. Uniformly labelled normal antisense riboprobes are hybridized with the total fibroblast RNA of patients with possible mutations in type I collagen. Mismatches in the resulting RNA/RNA hybrids are cleaved with RNase A and the labelled riboprobe cleavage products are examined electrophoretically. The sensitivity and specificity of the system were demonstrated by the detection and localization of a known point mutation in the codon for alpha 1(I) glycine 988 (1). DNA for sequencing the mutations localized by hybrid analysis may be obtained by either (1) generation of a fibroblast cDNA library and isolation of both alleles by plaque screening, or (2) a more rapid method using first strand cDNA synthesis from poly (A+)-mRNA, followed by PCR amplification of the mutation-containing region of the DNA/RNA hybrid. This strategy for detection and isolation has wide application not only for mutations causing connective tissue disorders, but also for mutations in other large and repetitive genes. We have used this strategy for the detection and sequencing of a point mutation in alpha 2(I) mRNA associated with a case of lethal osteogenesis imperfecta. The G----A point mutation in the codon for alpha 2(I) glycine residue 805 results in the substitution of an aspartic acid at this position and is consistent with the proband's collagen protein data.


Assuntos
Colágeno/genética , Mutação , RNA Mensageiro/genética , Ribonucleases/metabolismo , Alelos , Composição de Bases , Sequência de Bases , Clonagem Molecular , Brometo de Cianogênio , Humanos , Dados de Sequência Molecular , Hibridização de Ácido Nucleico , Osteogênese Imperfeita/genética , Reação em Cadeia da Polimerase , RNA/genética , RNA Antissenso , RNA Mensageiro/antagonistas & inibidores , Sequências Repetitivas de Ácido Nucleico , Mapeamento por Restrição
19.
J Biol Chem ; 264(20): 11893-900, 1989 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-2745420

RESUMO

We have identified a point mutation in one alpha 1(I) collagen allele (COL1A1) of a child with the type IV osteogenesis imperfecta phenotype. When compared to parental and control samples, skin fibroblasts of the proband synthesized two populations of type I collagen molecules. One population was normal; the other was delayed in secretion and electrophoretic migration due to post-translational overmodification. Two-dimensional gel electrophoresis of the CNBr peptides demonstrated a gradient of overmodification beginning near the carboxyl-terminal CB peptides. This predicts that the mutation delaying helix formation is near the carboxyl-terminal end of one of the component chains of type I collagen. The mRNA of the patient was probed with overlapping antisense riboprobes to type I collagen cDNA. Cleavage of a mismatch in RNA/RNA hybrids of RNase A allowed the location of the mutation to a 225-base pair region of alpha 1(I) cDNA. The mismatch was not present in RNA/RNA hybrids from either parent. This region of both alpha 1(I) alleles of the patient was isolated by screening a lambda ZAP cDNA library. Sequence determination of both alleles demonstrated a single nucleotide change, G----A, resulting in the substitution of a serine for a glycine at amino acid residue 832. This point mutation occurs in the coding region for alpha 1(I) CB6 and is concordant with the protein data. The finding of a glycine substitution in an alpha 1(I) chain of a patient with the milder type IV osteogenesis imperfecta phenotype requires modification of current molecular models for types II and IV osteogenesis imperfecta.


Assuntos
Alelos , Colágeno/genética , Mutação , Osteogênese Imperfeita/genética , Sequência de Aminoácidos , Autorradiografia , Sequência de Bases , Eletroforese em Gel Bidimensional , Feminino , Humanos , Lactente , Dados de Sequência Molecular , Hibridização de Ácido Nucleico
20.
Biochemistry ; 27(9): 3351-6, 1988 May 03.
Artigo em Inglês | MEDLINE | ID: mdl-3390435

RESUMO

Type I collagen, a heterotrimer of two alpha 1(I) chains and one alpha 2(I) chain, is the major structural protein of bone, skin, and tendon. The collagen of patients with bone diseases has been studied in skin fibroblasts instead of osteoblasts because the genes for type I collagen are single-copy genes. While these studies should detect structural changes in the gene, they might fail to detect defects in processes which are dependent on tissue-specific expression. The studies reported here sought to determine whether the expression of type I collagen in skin and bone was characterized by the use of alternate promoters or alternative splicing in the N-propeptide region. Primer extension and nuclease S1 protection experiments were used to analyze the structure of the alpha 2(I) mRNA from the 5' end of the gene through the N-telopeptide coding region (exons 1-6) in human and chick osteoblasts and fibroblasts. The protection and primer extension experiments using human and chick mRNA demonstrated identical routes of splicing in skin and bone at the first five splice junctions. These studies provide reassurance that information obtained from the study of type I collagen in fibroblasts may be extrapolated to bone.


Assuntos
Colágeno/genética , Tecido Conjuntivo/metabolismo , Osteoblastos/metabolismo , RNA Mensageiro/genética , Animais , Osso e Ossos/metabolismo , Embrião de Galinha , Fibroblastos/metabolismo , Humanos , Especificidade de Órgãos , RNA Mensageiro/isolamento & purificação , Especificidade da Espécie
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