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1.
Int J Obstet Anesth ; 58: 103968, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38485584

RESUMO

BACKGROUND: Hypotension is common during spinal anesthesia for cesarean delivery. Preventive strategies include fluid loading and phenylephrine. We hypothesized that if prophylactic phenylephrine infusion is used, omission of fluid loading would be non-inferior to fluid co-loading in maintaining cardiac output. We assumed that if there was a difference, the increase in cardiac output would be greater in the no-loading than in the co-loading group. METHODS: Term pregnant women scheduled for elective cesarean delivery were randomized to receive 1 L crystalloid co-loading or maintenance fluids only. Phenylephrine was titrated to maintain blood pressure. Changes in cardiac output following spinal anesthesia were the primary outcome. The study was powered as a non-inferiority trial, allowing the no-loading arm to have a 50% greater change in cardiac output. Heart rate, dose of phenylephrine, occurrence of nausea and vomiting, Apgar scores and neonatal acid base status were secondary outcomes. RESULTS: Data from 63 women were analyzed. In contrast to our hypothesis, there was 33% less increase in cardiac output with no loading (ratio 0.67, 95% CI 0.15 to 1.36), and 60% greater reduction of cardiac output with no loading (ratio 1.6, 95% CI 1.0 to 2.7). Total dose of phenylephrine was higher in the no-loading group. There may be a less favorable neonatal acid base status without volume loading. CONCLUSION: Omission of crystalloid co-loading leads to a decrease in cardiac output which has a potentially unfavorable impact on neonatal acid base status. We conclude that crystalloid co-loading may be useful in the presence of phenylephrine infusion.


Assuntos
Raquianestesia , Cesárea , Soluções Cristaloides , Hipotensão , Fenilefrina , Humanos , Feminino , Cesárea/métodos , Gravidez , Soluções Cristaloides/administração & dosagem , Soluções Cristaloides/uso terapêutico , Método Duplo-Cego , Hipotensão/prevenção & controle , Hipotensão/etiologia , Adulto , Raquianestesia/métodos , Raquianestesia/efeitos adversos , Fenilefrina/uso terapêutico , Anestesia Obstétrica/métodos , Anestesia Obstétrica/efeitos adversos , Procedimentos Cirúrgicos Eletivos , Débito Cardíaco/efeitos dos fármacos , Vasoconstritores/uso terapêutico
2.
Philos Trans A Math Phys Eng Sci ; 377(2137)2018 Dec 10.
Artigo em Inglês | MEDLINE | ID: mdl-30530544

RESUMO

The dome of Santa Maria del Fiore, Florence Cathedral, was built between 1420 and 1436 by architect Filippo Brunelleschi and it is now cracking under its own weight. Engineering efforts are under way to model the dome's structure and reinforce it against further deterioration. According to some scholars, Brunelleschi might have built reinforcement structures into the dome itself; however, the only known reinforcement is a wood chain 7.75 m above the springing of the Cupola. Multiple scattering muon radiography is a non-destructive imaging method that can be used to image the interior of the dome's wall and therefore ascertain the layout and status of any iron substructure in it. A demonstration measurement was performed at the Los Alamos National Laboratory on a mock-up wall to show the feasibility of the work proposed, and a lightweight and modular imaging system is currently under construction. We will discuss here the results of the demonstration measurement and the potential of the proposed technique, describe the imaging system under construction and outline the plans for the measurement.This article is part of the Theo Murphy meeting issue 'Cosmic-ray muography'.

3.
Phys Med ; 32(12): 1659-1666, 2016 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-27765457

RESUMO

PURPOSE: To predict patients who would benefit from adaptive radiotherapy (ART) and re-planning intervention based on machine learning from anatomical and dosimetric variations in a retrospective dataset. MATERIALS AND METHODS: 90 patients (pts) treated for head-neck cancer (H&N) formed a multicenter data-set. 41 H&N pts (45.6%) were considered for learning; 49 pts (54.4%) were used to test the tool. A homemade machine-learning classifier was developed to analyze volume and dose variations of parotid glands (PG). Using deformable image registration (DIR) and GPU, patients' conditions were analyzed automatically. Support Vector Machines (SVM) was used for time-series evaluation. "Inadequate" class identified patients that might benefit from replanning. Double-blind evaluation by two radiation oncologists (ROs) was carried out to validate day/week selected for re-planning by the classifier. RESULTS: The cohort was affected by PG mean reduction of 23.7±8.8%. During the first 3weeks, 86.7% cases show PG deformation aligned with predefined tolerance, thus not requiring re-planning. From 4th week, an increased number of pts would potentially benefit from re-planning: a mean of 58% of cases, with an inter-center variability of 8.3%, showed "inadequate" conditions. 11% of cases showed "bias" due to DIR and script failure; 6% showed "warning" output due to potential positioning issues. Comparing re-planning suggested by tool with recommended by ROs, the 4th week seems the most favorable time in 70% cases. CONCLUSIONS: SVM and decision-making tool was applied to overcome ART challenges. Pts would benefit from ART and ideal time for re-planning intervention was identified in this retrospective analysis.


Assuntos
Aprendizado de Máquina , Planejamento da Radioterapia Assistida por Computador/métodos , Radioterapia Assistida por Computador/métodos , Estudos de Coortes , Humanos , Reprodutibilidade dos Testes , Estudos Retrospectivos
4.
Am J Forensic Med Pathol ; 23(4): 326-8, 2002 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-12464805

RESUMO

The authors describe a case of suicide by a single shot to the head from the latest type of captive bolt pistol (which has lateral instead of frontal gas outlets), with the aim of finding criteria to identify correctly the lesions caused by this type of weapon correctly and to distinguish them from those caused by typical firearms.


Assuntos
Traumatismos Cranianos Penetrantes/patologia , Suicídio , Ferimentos por Arma de Fogo/patologia , Humanos , Masculino , Pessoa de Meia-Idade
5.
Clin Ter ; 152(4): 255-61, 2001.
Artigo em Italiano | MEDLINE | ID: mdl-11725619

RESUMO

Anaplastic thyroid carcinoma (ATC), accounting for 5% to 15% of primary malignant thyroid neoplasm, is one of the most aggressive solid tumors in humans. It is rapidly fatal, with a mean survival of 6 months after diagnosis. Multimodality treatment with surgery and/or external beam radiotherapy and chemotherapy are of fundamental importance for local control of disease and to enhance survival. Molecular biology studies have shown that ATC is associated with a p 53 mutation. ATC usually does not concentrate radioiodine or express thyroglobulin. It is essential to verify the diagnosis histologically because insular thyroid cancer, lymphomas, and medullary thyroid cancer are occasionally confused with undifferentiated neoplasms. Immunohistochemical study is helpful in establishing the diagnosis. Multimodal therapy and development of effective systemic chemotherapy agents would provide to result in improvements in survival although no single agent has yet been identified. Aggressive multimodality treatment regimens show promise in improving local control in patients with ATC. Survival rates however remain low. Despite intense applications of such integrated therapy, no standardized successful treatment protocol has yet been established.


Assuntos
Carcinoma/diagnóstico , Carcinoma/terapia , Neoplasias da Glândula Tireoide/diagnóstico , Neoplasias da Glândula Tireoide/terapia , Humanos
6.
Andrologia ; 33(3): 143-50, 2001 May.
Artigo em Inglês | MEDLINE | ID: mdl-11380329

RESUMO

To be practical, any method for improving bull semen must yield a large quantity of motile spermatozoa. Some separation methods based on physical properties, e.g. filtration, chromatography, centrifugation, washing and pooling, have been reported as satisfactory, but generally are not repeatable. Nevertheless, filtration methods appear to allow the attainment of an acceptable number of spermatozoa, thus allowing such a technique to be introduced in the production of standard bovine semen doses for artificial insemination. The aim of this work was to evaluate systematically the relative effects of three filtration matrixes (silica oxide, glass beads or Sephadexätrade mark) on the improvement of whole ejaculate quality. Analysis of the type of matrix and the volume and height of the filtration column was performed. The only characteristic of the columns that appears to influence ejaculate quality after filtering is the matrix volume. While all matrixes produced improvement of semen quality, SephadexTM was better than the other matrixes tested. An explanation for the mechanism of column filtration is proposed.


Assuntos
Separação Celular/métodos , Filtração , Espermatozoides/citologia , Espermatozoides/fisiologia , Acrossomo/fisiologia , Animais , Bovinos , Adesão Celular , Tamanho Celular , Corantes , Amarelo de Eosina-(YS) , Vidro , Soluções Hipotônicas , Modelos Lineares , Masculino , Microesferas , Contagem de Espermatozoides , Motilidade dos Espermatozoides
7.
Brain ; 124(Pt 4): 698-704, 2001 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-11287370

RESUMO

Nonsense mutations outside the splicing consensus sequence have been reported to cause skipping of the nonsense-containing exon in several human diseases. We describe, for the first time, nonsense-mediated exon skipping in the laminin alpha2 (LAMA2) gene. Two siblings from a consanguineous family had altered expression of the laminin alpha2 chain and moderate clinical manifestations. In both we identified the new nonsense mutation Arg744Stop, which we expected to result in a totally non-functional polypeptide. However, analysis of the transcript revealed skipping of exon 15, containing the mutation, even though the consensus sequences for splicing at both ends of the exon and the beginning of intron 15 were unaltered. Exon skipping restored the open reading frame of the mutant transcript and resulted in a truncated protein. In cases where the genetic findings do not elucidate the phenotype, mRNA analysis is necessary to clarify the primary effect of mutations. Our findings also point to the necessity of immunochemical screening for expression of laminin alpha2 chain in atypical dystrophic adults as well as children.


Assuntos
Códon sem Sentido , Éxons/genética , Laminina/genética , Distrofias Musculares/diagnóstico , Distrofias Musculares/genética , Adulto , Processamento Alternativo/genética , Consanguinidade , Contratura/etiologia , Análise Mutacional de DNA , Eletromiografia , Feminino , Humanos , Imuno-Histoquímica , Masculino , Debilidade Muscular/etiologia , Músculo Esquelético/patologia , Distrofias Musculares/fisiopatologia , Linhagem , Fenótipo , RNA Mensageiro/genética
8.
Horm Res ; 56(3-4): 130-3, 2001.
Artigo em Inglês | MEDLINE | ID: mdl-11847476

RESUMO

A 35-year-old woman was admitted to our hospital with the following complaints, headache, sweating, anxiety, dizziness, nausea, vomiting and severe hypertension. The technical images (abdominal CT, scintigraphic octreotide scan and renal arteriography) revealed the presence of a left adrenal pheochromocytoma and stenosis of the renal artery. Ten days following adrenalectomy, watery diarrhea appeared. The long-acting somatostatin analogue octreotide (LAR, 30 mg/month, i.m.), was started, and after 2 weeks diarrhea decreased and gradually disappeared. In conclusion, we were confronted with an unusual case of pheochromocytoma associated with renal artery stenosis and the appearance of watery diarrhea some days after surgical treatment. Treatment with octreotide brought about the remission of diarrhea in this patient.


Assuntos
Neoplasias das Glândulas Suprarrenais/complicações , Neoplasias das Glândulas Suprarrenais/cirurgia , Adrenalectomia/efeitos adversos , Diarreia/etiologia , Feocromocitoma/complicações , Feocromocitoma/cirurgia , Obstrução da Artéria Renal/complicações , Neoplasias das Glândulas Suprarrenais/diagnóstico , Adulto , Angiografia , Antidiarreicos/uso terapêutico , Diarreia/tratamento farmacológico , Feminino , Humanos , Octreotida/uso terapêutico , Feocromocitoma/diagnóstico , Obstrução da Artéria Renal/diagnóstico , Tomografia Computadorizada de Emissão de Fóton Único , Tomografia Computadorizada por Raios X
9.
Neuromuscul Disord ; 10(8): 567-71, 2000 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-11053683

RESUMO

We report on a patient with the typical clinical findings of Emery-Dreifuss muscular dystrophy due to a mutation in the emerin gene that should have produced a higher molecular weight protein. Immunohistochemical analysis showed emerin localized only in the cytoplasm of muscle fibres and lymphoblastoid cells. The emerin molecule contained the nucleoplasmic domain and the transmembrane domain responsible for nuclear membrane targeting, so its incorrect localization and lack of function could be due to abnormal folding resulting in rapid degradation or inability to bind other nuclear proteins.


Assuntos
Proteínas de Membrana/genética , Proteínas de Membrana/metabolismo , Músculo Esquelético/metabolismo , Distrofia Muscular de Emery-Dreifuss/genética , Timopoietinas/genética , Timopoietinas/metabolismo , Adolescente , Citoplasma/metabolismo , Citoplasma/ultraestrutura , Análise Mutacional de DNA , Humanos , Linfócitos/metabolismo , Masculino , Membrana Nuclear/metabolismo , Membrana Nuclear/ultraestrutura , Proteínas Nucleares , Estrutura Terciária de Proteína/genética
10.
Artigo em Inglês | MEDLINE | ID: mdl-10958151

RESUMO

1. The gamma-aminobutyric acid (GABA)-ergic system, which is functionally altered in obese (fa/fa) Zucker rats, plays an important role in controlling energy balance within the central nervous system. 2. GABA receptors seem to be involved in the dysfunction of the hypothalamic energy homeostasis-controlling mechanisms in these animals due to a genetically-induced defect of the leptin-neuropeptide Y system. 3. To shed further light on the possible role played by the GABA system in the pathogenesis of this rat model, two benzodiazepine (BDZ) receptor agonists (diazepam and clonazepam) and one BDZ antagonist (flumazenil) were administered intraperitoneally in obese and lean Zucker rats. 4. Body weight gain was reduced by the BDZ agonists in both phenotypes, and one receptor-agonist (diazepam) lowered insulin concentration in obese rats. In GABA-antagonist-treated obese rats, the daily amount of body weight gain and food intake acquired an oscillatory rhythm similar to that of normal rodents. 5. By demonstrating the role of BDZ receptors, these findings may help clarify the pathophysiology of obesity and insulin resistance in fatty Zucker rats.


Assuntos
Benzodiazepinas/farmacologia , Peso Corporal/efeitos dos fármacos , Ingestão de Alimentos/efeitos dos fármacos , Obesidade/fisiopatologia , Receptores de GABA-A/fisiologia , Animais , Feminino , Sistema Hipotálamo-Hipofisário/fisiologia , Resistência à Insulina , Masculino , Obesidade/veterinária , Ratos , Ratos Zucker
11.
Ann Neurol ; 47(6): 811-6, 2000 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-10852549

RESUMO

It is becoming evident that clinical phenotypes associated with partial laminin alpha2 chain deficiency are variable. We recently observed a 29-year-old man with leukoencephalopathy and vacuolar myopathy resembling inclusion body myositis. Laminin alpha2 immunohistochemical analysis showed reduction of the protein on muscle fiber surfaces. Molecular analysis revealed two novel compound heterozygous mutations in the LAMA2 gene. This is the first report linking a mutation in the LaMA2 gene with leukoencephalopathy and inclusion body-like myositis.


Assuntos
Encefalopatias/genética , Encefalopatias/patologia , Laminina/deficiência , Laminina/genética , Fibras Musculares Esqueléticas/patologia , Miosite/genética , Miosite/patologia , Adulto , Sequência de Aminoácidos , Sequência de Bases , Diagnóstico Diferencial , Éxons , Feminino , Heterozigoto , Humanos , Imuno-Histoquímica , Laminina/análise , Masculino , Miosite de Corpos de Inclusão/patologia , Linhagem , Vacúolos/patologia , Vacúolos/ultraestrutura
12.
J Med Genet ; 37(2): 102-7, 2000 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-10662809

RESUMO

Two young males with limb-girdle muscular dystrophy (LGMD) resulting from sarcoglycan deficiency died at 27 (patient 1) and 18 years (patient 2) of severe cardiomyopathy. Genetic analysis showed that they were compound heterozygotes for mutations in the beta sarcoglycan gene. One of these mutations, an 8 bp duplication in exon 3, was common to both patients. The second mutation in patient 2 was a 4 bp deletion at the splice donor site of intron 2, not reported previously. Patient 2 had more severe heart and skeletal muscle defects with faster deterioration; no sarcoglycans were detected in his skeletal muscle. The second mutation in patient 1, inferred because the unaffected father carries the 8 bp duplication, was not found. In patient 1, both heart and skeletal muscle were analysed and showed reduction of all sarcoglycans in both tissues and incorrect localisation of alpha and gamma sarcoglycans in heart. Therefore mutations in one sarcoglycan gene can disrupt the entire sarcoglycan complex in both skeletal and cardiac muscle. Differing expression patterns of sarcoglycan components in heart and skeletal muscle could be the result of alternatively spliced transcripts in these tissues. By sequencing an alternative transcript, highly expressed in the heart and skeletal muscle of patient 1, we found an 87 bp cryptic exon not previously reported. Although cardiomyopathy can result from mutations in alpha and gamma sarcoglycans, we show for the first time that the condition can also be caused by mutations in the beta sarcoglycan gene. This report therefore expands the phenotype of sarcoglycanopathies and suggests that cardiac function in LGMD patients with defective sarcoglycan expression should be monitored.


Assuntos
Cardiomiopatias/genética , Proteínas do Citoesqueleto/genética , Glicoproteínas de Membrana/genética , Distrofias Musculares/genética , Miocárdio/metabolismo , Adolescente , Adulto , Sequência de Bases , Análise Mutacional de DNA , Distroglicanas , Distrofina/genética , Éxons , Evolução Fatal , Feminino , Duplicação Gênica , Humanos , Masculino , Dados de Sequência Molecular , Músculo Esquelético/metabolismo , Mutação , Linhagem , Fenótipo
14.
Neuromuscul Disord ; 9(1): 28-33, 1999 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-10063832

RESUMO

We evaluated transforming growth factor-beta1 (TGF-beta1) expression in the muscle of four laminin alpha2-negative, four laminin alpha2-positive and seven partial laminin alpha2-deficient congenital muscular dystrophy (CMD) patients, and compared it to Duchenne muscular dystrophy (DMD) patients and controls. TGF-beta1 mRNA levels in skeletal muscle from laminin alpha2-negative and laminin alpha2-positive CMD patients were significantly greater than in controls (P < 0.05 and P < 0.005, respectively), while in partial laminin alpha2-deficient muscular dystrophy patients the amount was not significantly higher than in controls (P > 0.1). The TGF-beta1 values were lower than those found in DMD, although the extent of fibrosis was greater in CMD than in DMD and controls. Our findings suggest that TGF-beta1 is involved in CMD muscle fibrosis, but differently from what we observed in DMD muscles as it seems not to be the major player in connective tissue proliferation.


Assuntos
Distrofias Musculares/metabolismo , Distrofias Musculares/patologia , Fator de Crescimento Transformador beta/metabolismo , Adulto , Criança , Pré-Escolar , Tecido Conjuntivo/metabolismo , Tecido Conjuntivo/patologia , Feminino , Fibrose , Humanos , Imuno-Histoquímica , Lactente , Laminina/biossíntese , Laminina/deficiência , Masculino , Distrofias Musculares/genética , RNA Mensageiro/biossíntese , Fator de Crescimento Transformador beta/genética
15.
Arch Neurol ; 56(2): 209-15, 1999 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-10025426

RESUMO

BACKGROUND: Many patients with classic congenital muscular dystrophy have been found to have partial or total deficiency of the alpha2 chain of laminin 2 (merosin). This deficiency has mostly been studied using only 1 antibody against a fragment of the protein. OBJECTIVES: To characterize the expression of laminin alpha2 in the skeletal muscle of patients with laminin alpha2 deficiency using antibodies against 2 different portions of the protein and to correlate the immunochemical findings with clinical phenotype. METHODS: We studied 4 patients with total lack of laminin alpha2 and 12 with partial laminin alpha2 deficiency with immunohistochemical techniques and Western blot analysis. We used antibodies recognizing an 80-kd fragment toward the C-terminus and a 300-kd fragment toward the amino-terminal. Patient characteristics examined were functional compromise, magnetic resonance imaging or computed tomography of the brain, electromyography, evoked potentials, and creatine kinase levels. RESULTS: In 4 patients, immunohistochemical analysis revealed no reactivity to either antibody; in 2 patients, the 300-kd fragment alone was partially expressed; in 2 patients, the 80-kd fragment alone was partially expressed; and in 8 patients, both fragments were partially expressed. Immunoblot analysis revealed bands of reduced intensity and normal molecular weight generally corresponding to the immunohistochemical findings. Absence of both fragments or of one with reduction of the other always produced a severe clinical phenotype, while a milder clinical phenotype was observed when both fragments were partially expressed. CONCLUSIONS: Extent of laminin alpha2 deficiency in most cases correlates with clinical phenotype but not with peripheral and central white matter abnormalities. Skin biopsy specimens may reveal laminin alpha2 deficiency in patients who have normal laminin alpha2 levels in muscle biopsy specimens.


Assuntos
Laminina/deficiência , Fragmentos de Peptídeos/imunologia , Adolescente , Anticorpos Monoclonais , Criança , Humanos , Imuno-Histoquímica , Lactente , Recém-Nascido , Fenótipo
16.
Ann Ital Med Int ; 13(2): 111-6, 1998.
Artigo em Italiano | MEDLINE | ID: mdl-9734143

RESUMO

Two cases of neuroleptic malignant syndrome are reported. Although affecting chiefly psychiatric patients, this rare, polymorphic disease should be well-known to internists, general practitioners, and emergency staff because of its high risk of fatality. Our patients, who presented without some of the main symptoms, fell in the category of incomplete variants of the syndrome, the most difficult to recognize. In both patients, computerized tomography carried out at the outset of symptoms, evidenced signs of cerebral edema, a datum never before reported. The symptomatic polymorphism, pathogenesis, differential diagnosis, and therapy of this disease are illustrated and discussed.


Assuntos
Antipsicóticos/efeitos adversos , Síndrome Maligna Neuroléptica/etiologia , Esquizofrenia/tratamento farmacológico , Adulto , Diagnóstico Diferencial , Feminino , Humanos , Masculino , Síndrome Maligna Neuroléptica/diagnóstico
17.
Ann Neurol ; 42(2): 249-53, 1997 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-9266737

RESUMO

We have raised an anti-emerin polyclonal antibody against a fusion protein encompassing most of the hydrophilic portion of emerin. Using this antibody, we have analyzed emerin expression in Emery-Dreifuss muscular dystrophy (EDMD) patients and controls, by immunocytochemistry, in skeletal muscle and skin, and by immunoblot, in peripheral blood mononuclear cells and lymphoblasts. Emerin was localized on the surfaces of nuclei in control skeletal muscle and skin but was absent or reduced in patient skeletal muscle, was absent from the skin of patients, and was expressed only in a few nuclei in a patient's mother. Immunoblot of peripheral blood cells from EDMD patients showed absence of the emerin band, altered-size emerin, or a protein of normal molecular mass but slightly reduced quantity. The diagnosis of X-linked EDMD is normally confirmed by genetic analysis of the STA gene coding for emerin. We propose immunocytochemical evaluation of emerin expression in skin biopsies as a sensitive and more convenient tool for diagnosing X-linked EDMD and, in particular, for distinguishing it from the autosomal dominant form. This technique may be applied to suspected EDMD patients, especially sporadic cases or those with incomplete clinical phenotype, and also suspected carriers. Immunoblot of peripheral blood cells is also useful, but it may not unequivocally identify carriers and some patients.


Assuntos
Leucócitos Mononucleares/metabolismo , Linfócitos/metabolismo , Proteínas de Membrana/análise , Distrofias Musculares/diagnóstico , Distrofias Musculares/genética , Pele/patologia , Timopoietinas/análise , Cromossomo X , Adolescente , Adulto , Biomarcadores , Biópsia , Pré-Escolar , Feminino , Humanos , Imuno-Histoquímica , Laminas , Leucócitos Mononucleares/patologia , Linfócitos/patologia , Masculino , Proteínas de Membrana/biossíntese , Músculo Esquelético/metabolismo , Distrofias Musculares/sangue , Distrofias Musculares/patologia , Distrofia Muscular de Emery-Dreifuss , Proteínas Nucleares/análise , Valores de Referência , Pele/citologia , Pele/metabolismo , Timopoietinas/biossíntese
18.
Acta Neuropathol ; 94(1): 28-35, 1997 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-9224527

RESUMO

We have investigated the expression, using immunohistochemistry, of beta- and gamma-sarcoglycans in the muscles of 20 patients in whom previous screening had revealed a deficiency of alpha-sarcoglycan. alpha-, beta- and gamma-sarcoglycans were absent in 7 patients and variably reduced in 8 patients, in 2 of whom beta-sarcoglycan was more reduced than the alpha- and gamma-proteins. In 5 other patients with variably reduced alpha- and beta-sarcoglycans, gamma-sarcoglycan was completely absent. In all patients the distribution of hyposthenia at disease onset was similar, and predominantly involved pelvic girdle muscles; however, the age at onset and rate of disease progression were highly variable. In severely compromised patients, the onset of disease was before 10 years of age and gamma-sarcoglycan or all three sarcoglycans were absent from muscles. Immunohistochemical analysis of sarcoglycans should be part of routine screening for muscle dystrophies to identify patients with sarcoglycanopathy. Gene analysis is necessary to identify the primary defect; however, sarcoglycan immunohistochemistry may be useful for indicating which gene to investigate. Further biochemical characterization of the interactions between these proteins is required to fully elucidate their roles in causing severe, moderate or mild muscular dystrophy.


Assuntos
Proteínas do Citoesqueleto/deficiência , Glicoproteínas de Membrana/deficiência , Adolescente , Adulto , Western Blotting , Criança , Pré-Escolar , Proteínas do Citoesqueleto/química , Proteínas do Citoesqueleto/genética , Distroglicanas , Distrofina/biossíntese , Distrofina/deficiência , Distrofina/genética , Feminino , Humanos , Imuno-Histoquímica , Lactente , Recém-Nascido , Masculino , Glicoproteínas de Membrana/química , Glicoproteínas de Membrana/genética , Sarcoglicanas
19.
Hum Mol Genet ; 6(13): 2257-64, 1997 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-9361031

RESUMO

Emery-Dreifuss muscular dystrophy (EDMD) is an X-linked inherited disease characterized by early contracture of the elbows, Achilles tendons and post-cervical muscles, slow progressive muscle wasting and weakness and cardiomyopathy presenting with arrhythmia and atrial paralysis: heart block can eventually lead to sudden death. The EDMD geneencodes a novel ubiquitous protein, emerin, which decorates the nuclear rim of many cell types. Amino acid sequence homology and cellular localization suggested that emerin is a member of the nuclear lamina-associated protein family. These findings did not explain the role of emerin nor account for the skeletal muscle- and heart-specific clinical manifestations associated with the disorder. Now we report that emerin localizes to the inner nuclear membrane, via its hydrophobic C-terminal domain, but that in heart and cultured cardiomyocytes it is also associated with the intercalated discs. We propose a general role for emerin in membrane anchorage to the cytoskeleton. In the nuclear envelope emerin plays a ubiquitous and dispensable role in association of the nuclear membrane with the lamina. In heart its specific localization to desmosomes and fasciae adherentes could account for the characteristic conduction defects described in patients.


Assuntos
Desmossomos/química , Proteínas de Membrana/análise , Proteínas Musculares/análise , Distrofias Musculares/genética , Miocárdio/química , Membrana Nuclear/química , Timopoietinas/análise , Arritmias Cardíacas/etiologia , Adesão Celular , Proteínas do Citoesqueleto/análise , Citoesqueleto/metabolismo , Sistema de Condução Cardíaco/fisiopatologia , Humanos , Proteínas de Membrana/genética , Proteínas de Membrana/fisiologia , Microscopia Imunoeletrônica , Proteínas Musculares/genética , Proteínas Musculares/fisiologia , Distrofias Musculares/complicações , Distrofias Musculares/metabolismo , Distrofias Musculares/fisiopatologia , Distrofia Muscular de Emery-Dreifuss , Miocárdio/ultraestrutura , Proteínas Nucleares , Fosforilação , Processamento de Proteína Pós-Traducional , Timopoietinas/genética , Timopoietinas/fisiologia , Cromossomo X
20.
Acta Neuropathol ; 92(4): 369-77, 1996 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-8891069

RESUMO

The absence of dystrophin in muscle fibers is associated with a major reduction in dystrophin-associated proteins (DAPs) and disruption of the linkage between the subsarcolemmal cytoskeleton and the extracellular matrix. We investigated the expression of the DAPs beta-dystroglycan, alpha-sarcoglycan, gamma-sarcoglycan and syntrophin as well as utrophin in the muscles of 13 Duchenne muscular dystrophy (DMD) carriers (with variable percentages of dystrophin-deficient fibers and with a range of clinical symptoms), 2 Becker muscular dystrophy (BMD) carriers (expressing a highly truncated protein in some fibers), 2 girls with a DMD-like phenotype, and 11 BMD carriers with almost normal dystrophin expression (reduced or patchy distribution in a few fibers only and rare dystrophin-deficient fibers). DAPs were highly reduced in all fibers lacking dystrophin in the DMD carriers, but were almost normal in the dystrophin-deficient fibers of the 2 BMD carriers with highly truncated dystrophin. In the 11 BMD carriers with nearly normal dystrophin, the few fibers with reduced or patchy dystrophin immunostaining also showed reduced DAP expression in correlation with dystrophin expression. Immunoblot for beta-dystroglycan and alpha-sarcoglycan confirmed the immunohistochemical findings. Utrophin expression was slightly increased in a proportion of fibers in the DMD and BMD carriers with dystrophin mosaicism. We found no correlation between utrophin expression and DAP expression. We conclude that absence or reduction of dystrophin in muscle fibers of DMD and BMD carriers causes a reduction of DAPs in the same fibers, as observed in DMD and BMD patients, while utrophin does not seem to play a role in DAP expression in adult muscle.


Assuntos
Proteínas do Citoesqueleto/análise , Proteínas Associadas à Distrofina , Distrofina/deficiência , Heterozigoto , Glicoproteínas de Membrana/análise , Fibras Musculares Esqueléticas/química , Fibras Musculares Esqueléticas/efeitos dos fármacos , Proteínas Musculares/imunologia , Distrofias Musculares/genética , Distrofias Musculares/fisiopatologia , Adolescente , Adulto , Idoso , Proteínas de Ligação ao Cálcio , Criança , Pré-Escolar , Distroglicanas , Distrofina/análogos & derivados , Feminino , Humanos , Immunoblotting , Lactente , Proteínas de Membrana/análise , Proteínas Musculares/análise , Distrofias Musculares/patologia , Sarcoglicanas , Utrofina
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