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1.
Rep Prog Phys ; 83(12): 124201, 2020 Nov 21.
Artigo em Inglês | MEDLINE | ID: mdl-33226008

RESUMO

The combination of the high intensity proton beam facilities and massive detectors for precision measurements of neutrino oscillation parameters including the charge-parity violating (CPV) phase will open the door to help make beyond the standard model (BSM) physics reachable even in low energy regimes in the accelerator-based experiments. Large-mass detectors with highly precise tracking and energy measurements, excellent timing resolution, and low energy thresholds will enable the searches for BSM phenomena from cosmogenic origin, as well. Therefore, it is also conceivable that BSM topics in the next-generation neutrino experiments could be the dominant physics topics in the foreseeable future, as the precision of the neutrino oscillation parameter and CPV measurements continue to improve.This paper provides a review of the current landscape of BSM theory in neutrino experiments in two selected areas of the BSM topics-dark matter and neutrino related BSM-and summarizes the current results from existing neutrino experiments to set benchmarks for both theory and experiment. This paper then provides a review of upcoming neutrino experiments throughout the next 10 to 15 year time scale and their capabilities to set the foundation for potential reach in BSM physics in the two aforementioned themes. An important outcome of this paper is to ensure theoretical and simulation tools exist to carry out studies of these new areas of physics, from the first day of the experiments, such as Deep Underground Neutrino Experiment in the U.S. and Hyper-Kamiokande Experiment in Japan.

2.
Curr Top Microbiol Immunol ; 324: 149-65, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-18481459

RESUMO

T cells play a central role in the development of immune responses. Patients lacking T cells because of genetic defects such as DiGeorge or Nezelof syndromes and patients infected with the human immunodeficiency virus are highly susceptible to infections and cancers. The lack of adequate in vivo models of T cell neogenesis have hindered the development and clinical implementation of effective therapeutic modalities aimed at treating these and other clinically important maladies. Transplantation of severe combined immunodeficient (SCID) mice with human hematopoietic stem cells results in long-term engraftment and systemic reconstitution with human progenitor, B, and myeloid cells, but curiously, human T cells are rarely present in any tissue. While the implantation of SCID mice with human fetal thymus and liver (SCID-hu thy/liv mice) allows the development of abundant thymocytes that are localized in the human organoid implant, there is minimal systemic repopulation with human T cells. However, we have recently shown that transplantation of autologous human hematopoietic fetal liver CD34+ cells into the nonobese diabetic (NOD)/SCID mouse background previously implanted with fetal thymic and liver tissues results in long-term, systemic human T cell homeostasis. In addition to human T cells, these mice have systemic repopulation with human B cells, monocytes/macrophages, and dendritic cells (DC). Importantly, in these mice the T cells developed in the human thymic implant are capable of being activated by human antigen-presenting cells and mount potent human MHC-restricted T cell immune responses.


Assuntos
Sistema Hematopoético/fisiologia , Sistema Imunitário/fisiologia , Modelos Animais , Animais , Transplante de Células-Tronco Hematopoéticas , Humanos , Camundongos , Camundongos Endogâmicos NOD , Camundongos SCID , Transplante de Órgãos , Timo/imunologia
3.
Science ; 270(5237): 819-22, 1995 Nov 03.
Artigo em Inglês | MEDLINE | ID: mdl-7481775

RESUMO

Severe childhood autosomal recessive muscular dystrophy (SCARMD) is a progressive muscle-wasting disorder common in North Africa that segregates with microsatellite markers at chromosome 13q12. Here, it is shown that a mutation in the gene encoding the 35-kilodalton dystrophin-associated glycoprotein, gamma-sarcoglycan, is likely to be the primary genetic defect in this disorder. The human gamma-sarcoglycan gene was mapped to chromosome 13q12, and deletions that alter its reading frame were identified in three families and one of four sporadic cases of SCARMD. These mutations not only affect gamma-sarcoglycan but also disrupt the integrity of the entire sarcoglycan complex.


Assuntos
Cromossomos Humanos Par 13 , Proteínas do Citoesqueleto , Glicoproteínas de Membrana/genética , Distrofias Musculares/genética , Sequência de Aminoácidos , Animais , Sequência de Bases , Mapeamento Cromossômico , DNA Complementar/genética , Distrofina/química , Distrofina/genética , Distrofina/metabolismo , Humanos , Desequilíbrio de Ligação , Glicoproteínas de Membrana/química , Glicoproteínas de Membrana/metabolismo , Dados de Sequência Molecular , Peso Molecular , Músculo Esquelético/química , Músculo Esquelético/metabolismo , Mutação , Fenótipo , Coelhos , Sarcoglicanas , Deleção de Sequência
4.
Nat Commun ; 9(1): 3525, 2018 08 30.
Artigo em Inglês | MEDLINE | ID: mdl-30166549

RESUMO

Plasmacytoid dendritic cells (pDC) are essential for immune competence. Here we show that pDC precursor differentiated from human CD34+ hematopoietic stem and progenitor cells (HSPC) has low surface expression of pDC markers, and has limited induction of type I interferon (IFN) and IL-6 upon TLR7 and TLR9 agonists treatment; by contrast, cGAS or RIG-I agonists-mediated activation is not altered. Importantly, after priming with type I and II IFN, these precursor pDCs attain a phenotype and functional activity similar to that of peripheral blood-derived pDCs. Data from CRISPR/Cas9-mediated genome editing of HSPCs further show that HSPC-pDCs with genetic modifications can be obtained, and that expression of the IFN-α receptor is essential for the optimal function, but dispensable for the differentiation, of HSPC-pDC percursor. Our results thus demonstrate the biological effects of IFNs for regulating pDC function, and provide the means of generating of gene-modified human pDCs.


Assuntos
Antígenos CD34/metabolismo , Células Dendríticas/metabolismo , Sistemas CRISPR-Cas/genética , Diferenciação Celular/genética , Diferenciação Celular/fisiologia , Células Cultivadas , Proteína DEAD-box 58/metabolismo , Ensaio de Imunoadsorção Enzimática , Edição de Genes , Humanos , Interferon Tipo I/metabolismo , Interleucina-6/metabolismo , Nucleotidiltransferases/metabolismo , Reação em Cadeia da Polimerase , Receptor de Interferon alfa e beta/genética , Receptor de Interferon alfa e beta/metabolismo , Receptores Imunológicos , Receptor 7 Toll-Like/agonistas , Receptor Toll-Like 9/agonistas
5.
Mucosal Immunol ; 11(2): 449-461, 2018 03.
Artigo em Inglês | MEDLINE | ID: mdl-28766555

RESUMO

Toll-like receptor 9 (TLR9) agonists are being developed for treatment of colorectal and other cancers, yet the impact of these drugs on human intestines remains unknown. This, together with the fact that there are additional potential indications for TLR9 agonist therapy (e.g., autoimmune and infectious diseases), led us to investigate the impact of MGN1703 (Lefitolimod) on intestinal homeostasis and viral persistence in HIV-positive individuals. Colonic sigmoid biopsies were collected (baseline and week four) from 11 HIV+ individuals on suppressive antiretroviral therapy, who received MGN1703 (60 mg s.c.) twice weekly for 4 weeks in a single-arm, phase 1b/2a study. Within sigmoid mucosa, global transcriptomic analyses revealed 248 modulated genes (false discovery rate<0.05) including many type I interferon (IFN)-stimulated genes. MGN1703 increased the frequencies of cells exhibiting MX1 (P=0.001) and ISG15 (P=0.014) protein expression. No changes were observed in neutrophil infiltration (myeloperoxidase; P=0.97). No systematic effect on fecal microbiota structure was observed (analysis of similarity Global R=-0.105; P=0.929). TLR9 expression at baseline was inversely proportional to the change in integrated HIV DNA during MGN1703 treatment (P=0.020). In conclusion, MGN1703 induced a potent type I IFN response, without a concomitant general inflammatory response, in the intestines.


Assuntos
Colo Sigmoide/fisiologia , DNA/uso terapêutico , Microbioma Gastrointestinal/efeitos dos fármacos , Infecções por HIV/imunologia , HIV-1/fisiologia , Intestinos/imunologia , Receptor Toll-Like 9/agonistas , Colo Sigmoide/efeitos dos fármacos , Colo Sigmoide/virologia , Citocinas/genética , Citocinas/metabolismo , DNA Viral/genética , Feminino , Perfilação da Expressão Gênica , Infecções por HIV/tratamento farmacológico , Homeostase , Humanos , Imunidade nas Mucosas/efeitos dos fármacos , Interferon Tipo I/metabolismo , Intestinos/efeitos dos fármacos , Intestinos/virologia , Masculino , Proteínas de Resistência a Myxovirus/genética , Proteínas de Resistência a Myxovirus/metabolismo , Ubiquitinas/genética , Ubiquitinas/metabolismo , Carga Viral/efeitos dos fármacos
6.
J Diabetes Complications ; 14(1): 18-24, 2000.
Artigo em Inglês | MEDLINE | ID: mdl-10925062

RESUMO

To ascertain the quality of life associated with the health state of diabetes mellitus using utility value analysis. Consecutive adult patients with diabetes mellitus for at least 1 year and a mean age of 61.7 years (range 21-85 years) were interviewed in a cross-sectional fashion using standardized research methodology. Utility analysis values were obtained employing the time tradeoff method and were correlated with clinical parameters of the sample group, as well as with co-morbidities using the heteroscedastic Student's t-test and multivariate linear regression. The chi(2) distribution to test for independence was used to compare sample subgroups. With a sample of 292 patients, the mean, patient-preference-based, time tradeoff utility value associated with the health state of diabetes mellitus was 0.88 (standard deviation (SD)=0.17; 95% confidence interval (CI), 0.86-0.90). Repeat analysis confirmed the reproducibility of the data. Thus, the average diabetic was willing to trade away 12% of his or her remaining life in return for a diabetic-free health state. Factors associated with a significant decrease in diabetic-associated quality of life included: (1) the requirement for insulin (p=0.05), (2) the presence of depression (p=0.01), (3) the presence of diabetic retinopathy (p=0.03) and the presence of co-morbidities in general (p=0.01). The health state of diabetes mellitus has a significant effect upon patient, preference-based quality of life. The presence of diabetic co-morbidities and dependence upon insulin appear to decrease quality of life. The utility value associated with the health state of diabetes mellitus is of substantial importance for use in the calculation of cost-effective analyses.


Assuntos
Diabetes Mellitus/psicologia , Qualidade de Vida , Adulto , Idoso , Idoso de 80 Anos ou mais , Depressão , Complicações do Diabetes , Nefropatias Diabéticas , Neuropatias Diabéticas , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Reprodutibilidade dos Testes
7.
Adv Neurol ; 79: 239-52, 1999.
Artigo em Inglês | MEDLINE | ID: mdl-10514818

RESUMO

To understand the cellular and molecular mechanisms that underlie generalized absence seizures sufficiently well to design rational, efficacious new therapies for patients, it is necessary to turn to animal models to gain insights into these mechanisms. The lethargic (lh/lh) mutant mouse expresses spontaneous absence seizures that share behavioral, electrographic, and anticonvulsant profiles with absence seizures in patients. This validates its use to study the mechanisms that underlie absence seizures. This chapter discusses two scientific approaches that involve the use of lh/lh mice. The first part of the chapter discusses neurobiologic approaches used to investigate critical mechanisms that regulate the synchronized burst firing within the thalamocortical network that generates absence seizures. Two of these critical mechanisms have been studied in detail with lh/lh mice. The first critical mechanism involves the required activation of gamma-aminobutyric acid B (GABAB) receptors to generate absence seizures. Because the numbers of GABAB receptors are increased in thalamocortical populations among lh/lh mice compared with littermates without epilepsy, these receptors appear to play a pathophysiologic role in the expression of absence seizures among lh/lh mice. Moreover, there may be a role for GABAB receptors in the generation of absence seizures among humans, because administration of compounds that activate GABAB receptors can produce absence seizures among humans. These findings suggest that GABAB receptor antagonists may represent a new class of antiabsence compounds that will be efficacious against absence seizures among patients. A second critical mechanism that regulates generation of absence seizures involves GABAA receptors in the nucleus reticularis thalami (NRT), a nucleus that sends GABA-ergic afferents to thalamic relay nuclei. Activation of GABAA receptors in the NRT appears to suppress the generation of absence seizures among lh/lh mice and in other models. Moreover, clonazepam may exert its antiabsence actions through this mechanism. Together, these findings suggest that compounds that selectively activate GABAA receptor isoforms expressed in NRT may represent a class of antiabsence drugs that could have fewer side effects than compounds currently used to treat patients. The second part of the chapter discusses a molecular genetic approach to delineation of the mechanisms that underlie absence seizures. Absence seizures among lh/lh mice are caused by a single-gene defect on chromosome 2. If positional cloning and gene isolation techniques are successful, it will be possible to identify the lh disease gene. Subsequent studies of the lh gene product should greatly increase not only our understanding of the pathophysiologic basis for absence seizures among lh/lh mice but also our ability to seek similar mutations in homologous genes in human families that express absence seizures. Accordingly, strategies and progress in cloning and identifying the lh disease gene are presented.


Assuntos
Clonagem Molecular , Epilepsia Tipo Ausência/genética , Regulação da Expressão Gênica , Camundongos Mutantes Neurológicos/genética , Camundongos Mutantes Neurológicos/fisiologia , Receptores de GABA/genética , Animais , Mapeamento Cromossômico , Camundongos
8.
Bioorg Chem ; 28(4): 205-213, 2000 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-11034782

RESUMO

A structure-activity relationship is presented that satisfactorily predicts the rates of hydrolysis of a series of acetylglycine derivatives by porcine aminoacylase. It is apparent that the substrate specificity of aminoacylase is mainly kinetic in origin, the observed correlation with Taft's E(s) parameter supporting the notion that enzymolysis proceeds through a mechanism that is analogous to chemical hydrolysis. It is suggested that the alpha-CH(2)CH group of those substrates that possess this moiety is conformationally immobile upon binding. This lock facilitates rapid hydrolysis and results from steric interactions between the enzyme and substrate. The incorporation of alpha-methyl amino acid derivatives in the structure-activity relationship is consistent with a flexible active site model and it is concluded that the alpha-methyl effect in this system is a binding phenomenon. It is evident that the active center of porcine aminoacylase can comfortably accommodate amino acid derivatives with side chains containing less than six carbon atoms, contrary to previous assertions. It is suggested that the binding of bulkier derivatives necessitates the distortion of the active site. Derivatives possessing beta-hydroxyl groups are found to deviate from expected behavior and a nonproductive binding model is presented. Copyright 2000 Academic Press.

9.
Mucosal Immunol ; 5(5): 555-66, 2012 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-22569301

RESUMO

Intestinal immune cells are important in host defense, yet the determinants for human lymphoid homeostasis in the intestines are poorly understood. In contrast, lymphoid homeostasis has been studied extensively in mice, where the requirement for a functional common γ-chain molecule has been established. We hypothesized that humanized mice could offer insights into human intestinal lymphoid homeostasis if generated in a strain with an intact mouse common γ-chain molecule. To address this hypothesis, we used three mouse strains (non-obese diabetic (NOD)/severe-combined immunodeficient (SCID) (N/S); NOD/SCID γ-chain(-/-) (NSG); and Rag2(-/-) γ-chain(-/-) (DKO)) and two humanization techniques (bone marrow liver thymus (BLT) and human CD34(+) cell bone marrow transplant of newborn mice (hu)) to generate four common types of humanized mice: N/S-BLT, NSG-BLT, NSG-hu, and DKO-hu mice. The highest levels of intestinal human T cells throughout the small and large intestines were observed in N/S-BLT mice, which have an intact common γ-chain molecule. Furthermore, the small intestine lamina propria T-cell populations of N/S-BLT mice exhibit a human intestine-specific surface phenotype. Thus, the extensive intestinal immune reconstitution of N/S-BLT mice was both quantitatively and qualitatively better when compared with the other models tested such that N/S-BLT mice are well suited for the analysis of human intestinal lymphocyte trafficking and human-specific diseases affecting the intestines.


Assuntos
Células da Medula Óssea/imunologia , Subunidade gama Comum de Receptores de Interleucina/metabolismo , Intestinos/imunologia , Linfócitos T/imunologia , Quimeras de Transplante , Animais , Animais Recém-Nascidos , Antígenos CD34/metabolismo , Transplante de Medula Óssea , Proteínas de Ligação a DNA , Modelos Animais de Doenças , Homeostase , Humanos , Subunidade gama Comum de Receptores de Interleucina/genética , Camundongos , Camundongos Endogâmicos NOD , Camundongos Knockout , Camundongos SCID
11.
Nurs Stand ; 9(22): 55, 1995.
Artigo em Inglês | MEDLINE | ID: mdl-7703139
16.
Mult Scler ; 8(6): 469-74, 2002 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-12474985

RESUMO

Two histocompatible substrains of BALB/c mice (BALB/cByJ, BALB/cAnNCr) are resistant and susceptible, respectively, to Theiler's murine encephalomyelitis virus-induced demyelinating disease (TMEV-1DD)--a model for viral etiology of human multiple sclerosis. BALB/cByJ mice become susceptible following low-dose irradiation given prior to infection. Resistance is restored by adoptive transfer of CD8+ (but not CD4+) splenic T cells from infected, unirradiated BALB/cByJ donors. In contrast resistance is conferred to BALB/cAnNCr mice by adoptive transfer of either CD4+ or CD8+ T cells from resistant BALB/cByJ donors. T cells from BALB/cAnNCr mice cannot confer protection. To integrate these two observations, we hypothesized that the BALB/cAnNCr mice possess precursors of the regulatory CD8+ T cells, but fail to activate them because they lack a critical CD4+ T-cell subpopulation. We tested this model using serial transfers. The transfer of CD4+ T cells from the BALB/cByJ to the BALB/cAnNCr mice permitted development of BALB/cAnNCr CD8+ T cells that in turn, provided resistance when transferred into susceptible recipients. The BALB/cByJ CD4+ T cells, which activated the CD8+ cells, were sensitive to low-dose irradiation, unlike CD4+ T cells involved in the later inflammatory demyelination. Thus, susceptibility of BALB/cAnNCr mice is due to a defective/absent CD4+ T-cell subset acting immediately after infection.


Assuntos
Linfócitos T CD4-Positivos/imunologia , Infecções por Cardiovirus/imunologia , Doenças Desmielinizantes/imunologia , Doenças Desmielinizantes/virologia , Theilovirus , Animais , Linfócitos T CD4-Positivos/efeitos da radiação , Linfócitos T CD8-Positivos/imunologia , Suscetibilidade a Doenças/imunologia , Feminino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos DBA
17.
Blood ; 72(4): 1407-11, 1988 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-3262389

RESUMO

Two men with factor IX (FIX)antigen-positive (CRM+) hemophilia B were selected for study because of their abnormal expression of an immunologically defined epitope previously localized to the EGF-like domains of the molecule. Exons IV and V (coding for the first and second EGF-like domains) of FIX were amplified 10(7) times from the patients' genomic DNA by using polymerase chain reaction (PCR) technology and sequenced. Both patients had identical mutations which resulted in the highly conserved Gly 60 residue being changed to Ser. PCR-amplified exon IV from six normal males had the previously defined canonic sequence. The correlation between the mutation and defective epitope expression in the two patients suggests that a change in the tertiary structure of the EGF-like domain is likely to cause the mild hemophilia B.


Assuntos
DNA Polimerase Dirigida por DNA , Fator de Crescimento Epidérmico/genética , Fator IX/genética , Amplificação de Genes , Hemofilia A/genética , Adulto , Sequência de Aminoácidos , Clonagem Molecular , Humanos , Masculino , Pessoa de Meia-Idade , Dados de Sequência Molecular , Mutação
18.
Heart Vessels ; 9(3): 155-66, 1994.
Artigo em Inglês | MEDLINE | ID: mdl-8056722

RESUMO

The peak pressure which a chamber would develop in isovolumic contraction at end-diastolic distention (peak source pressure) is an expression of contractile vigor and a determinant of systolic performance. One can predict source pressure of an ejecting beat by fitting its isovolumic phases with a model isovolumic-wave function. Characteristics of the left-ventricular isovolumic pressure wave (amplitude, duration, shape) were studied in isolated, perfused, artificially loaded dog hearts, where strictly isovolumic conditions could be obtained over a wide range of cavity volumes at constant heart rate and approximately constant contractile state. The characterization involved two steps: (1) beginning and ending points were identified by a transition-locating algorithm, and (2) Fourier analysis was performed on points in between. The amplitude of the isovolumic pressure wave increased with cavity volume as expected, the duration of contraction increased with cavity volume, and the shape of the wave (normalized Fourier coefficients) depended slightly on the cavity volume. Duration of contraction declined slightly with increasing heart rate, but the shape of the isovolumic pressure wave was independent of heart rate. The mean shape was similar to that found in dog hearts subjected to one-beat aortic-root clamping in vivo-the wave being less sharply peaked than a cosine wave and tilted to the left because relaxation was slower than contraction. When ejecting beat duration declined linearly with increasing ejection fraction. This relation could be used to predict the duration of the isovolumic beat corresponding to the duration of an ejecting beat. Source pressure could then be predicted by fitting a model isovolumic wave of predicted duration to the isovolumic contraction phase of the ejecting beat. In 270 comparisons, the ratio of predicted peak source pressure to observed peak source pressure was 1.04 +/- 0.10 (SD). This method provides a reasonably accurate prediction of an important determinant of systolic performance.


Assuntos
Pressão Sanguínea/fisiologia , Modelos Cardiovasculares , Contração Miocárdica/fisiologia , Volume Sistólico/fisiologia , Função Ventricular Esquerda/fisiologia , Animais , Estimulação Cardíaca Artificial , Cães , Eletrocardiografia/instrumentação , Análise de Fourier , Frequência Cardíaca/fisiologia , Perfusão , Processamento de Sinais Assistido por Computador/instrumentação
19.
Am J Physiol ; 268(5 Pt 2): H1803-13, 1995 May.
Artigo em Inglês | MEDLINE | ID: mdl-7771531

RESUMO

Gadolinium-sensitive stretch-activated channels have been implicated in the process of mechanotransduction signaling of ventricular myocardium. Such channels nonspecifically transport Na+ and Ca2+ in the inward direction. We tested the hypothesis that Na+ and Ca2+ influx are important in the genesis of stretch-induced arrhythmias (SIAs) in an isolated, blood-perfused canine ventricle. To elicit SIAs, left ventricular volume was transiently increased in early diastole using a computerized servo-pump system. Monophasic action potential recordings revealed stretch-induced depolarizations (SIDs) that preceded the arrhythmias. In five ventricles, raising the perfusate Ca2+ concentration from 1 to 3 mM increased ventricular sensitivity to SIAs, manifested by a decrease in the volume change required to precipitate an arrhythmia 50% of the time (delta V50) from 19.5 +/- 2.7 to 15.2 +/- 1.9 ml (P < 0.05). When the perfusate Na+ concentration was decreased from 150 to 90 mM in seven ventricles, delta V50 greatly increased (31.1 +/- 14.4 vs. 17.7 +/- 5.3 ml, P < 0.05), and SID amplitude decreased by 47% (P = 0.002). The suppression of SIAs with low extracellular Na+ is unlikely to be mediated by voltage-gated Na+ channels because lidocaine (5 mg/dl) did not alter SID amplitude. Thus the transsarcolemmal Na+ gradient (and probably that of Ca2+) modulates the amplitude of SIDs, which, in turn, initiate SIAs. These data provide initial evidence that Na+ and Ca2+ help mediate the mechanotransduction processes that underly the genesis of SIAs.


Assuntos
Arritmias Cardíacas/etiologia , Arritmias Cardíacas/fisiopatologia , Cálcio/farmacologia , Contração Miocárdica/fisiologia , Sódio/farmacologia , Função Ventricular , Animais , Cães , Eletrofisiologia , Hemodinâmica/efeitos dos fármacos , Lidocaína/farmacologia , Concentração Osmolar , Ratos
20.
Am J Hum Genet ; 59(5): 1040-7, 1996 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-8900232

RESUMO

Autosomal recessive muscular dystrophy is genetically heterogeneous. One form of this disorder, limb-girdle muscular dystrophy type 2C (LGMD 2C), is prevalent in northern Africa and has been shown to be associated with a single mutation in the gene encoding the dystrophin-associated protein gamma-sarcoglycan. The previous mutation analysis of gamma-sarcoglycan required the availability of muscle biopsies. To establish a mutation assay for genomic DNA, the intron-exon structure of the gamma-sarcoglycan gene was determined, and primers were designed to amplify each of the exons encoding gamma-sarcoglycan. We studied a group of Brazilian muscular dystrophy patients for mutations in the gamma-sarcoglycan gene. These patients were selected on the basis of autosomal inheritance and/or the presence of normal dystrophin and/or deficiency of alpha-sarcoglycan immunostaining. Four of 19 patients surveyed had a single, homozygous mutation in the gamma-sarcoglycan gene. The mutation identified in these patients, all of African-Brazilian descent, is identical to that seen in the North African population, suggesting that even patients of remote African descent may carry this mutation. The phenotype in these patients varied considerably. Of four families with an identical mutation, three have a severe Duchenne-like muscular dystrophy. However, one family has much milder symptoms, suggesting that other loci may be present that modify the severity of the clinical course resulting from gamma-sarcoglycan gene mutations.


Assuntos
Proteínas do Citoesqueleto , Glicoproteínas de Membrana/genética , Distrofias Musculares/genética , Adolescente , Adulto , África do Norte/etnologia , Brasil/epidemiologia , Criança , Feminino , Humanos , Masculino , Dados de Sequência Molecular , Distrofias Musculares/etnologia , Linhagem , Mutação Puntual , Polimorfismo Genético , Sarcoglicanas
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