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1.
Environ Pollut ; 255(Pt 2): 113162, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31546079

RESUMO

Hexa-mix-chlorinated/brominated benzenes (HXBs), a group of newly found analogues of hexachlorobenzene (HCB) and hexabromobenzene (HBB), may exhibit similar environmental risks and toxicities as HCB and HBB, and therefore possess high interests in environmental and toxicological research. Yet information regarding HXBs in the environment remains scarce. In this study, we developed an isotope dilution method for quantitative and semiquantitative determination of five HXBs in fly ash, soil and air using gas chromatography high resolution mass spectrometry (GC-HRMS) in multiple ion detection mode. The samples were Soxhlet-extracted and purified with multilayer composite silica gel-alumina columns, followed by GC-HRMS detection. Identification of HXBs was conducted by the comparison between theoretical and detected mass spectra using paired-samples T test and cosine similarity analysis. Two HXBs (C6BrCl5 and C6Br4Cl2) with reference standards were quantitatively determined while the rest three (C6Br2Cl4, C6Br3Cl3 and C6Br5Cl) without reference standards were semiquantitatively analyzed by sharing the calibration curves of C6BrCl5 and C6Br4Cl2 in cooperation with isotopologue distribution computation. The accuracies for C6BrCl5 and C6Br4Cl2 were 87.3-107.8% with relative standard deviations (RSD) of 2.8-5.0%. The method limits of quantification of the HXBs were 0.10 ng/g in fly ash and soil samples and 0.09 pg/m3 in ambient air samples. The recoveries ranged from 42.7% to 102.1% with RSD of 3.7-13.9%. This method has been successfully applied to the analysis of the HXBs in the environmental samples. The total concentrations of HXBs in the fly ash, soil and ambient air samples were 19.48 ng/g, 10.44 ng/g and 5.13 pg/m3, respectively, which accounted for 10.6%, 0.4% and 10.8% of the corresponding total concentrations of HCB and HBB. This study provides a reference method for quantitative and/or semiquantitative analyses of novel mix-halogenated organic compounds, and sheds light on the full picture of HXBs pollution in the environment.


Assuntos
Benzeno/análise , Cinza de Carvão/análise , Monitoramento Ambiental/métodos , Poluentes Ambientais/análise , Cromatografia Gasosa-Espectrometria de Massas/métodos , Halogenação , Hexaclorobenzeno/análise , Hexosaminidase A , Solo/química
2.
Protein Expr Purif ; 163: 105446, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-31271862

RESUMO

Helicobacter pylori is a pathogenic microorganism infecting approximately 50% of the global population, and establishes life-long colonization despite the hostile stomach environment. H. pylori employs a wide range of outer membrane proteins (adhesins) for epithelial attachment, which specifically bind to glycans or non-carbohydrate structures expressed on the gastric epithelium. A recently described adhesin from H. pylori is LabA, named after its ability to bind to a disaccharide present in gastric mucus (LacdiNAc-specific adhesin). Here, we describe the recombinant expression of LabA from H. pylori strains J99 and 26695 in E. coli. High yields of recombinant LabA were obtained using periplasmic expression. We found that the addition of a C-terminal hexalysine (6K) tag enhanced the thermal stability of LabA without affecting its secondary structure, using differential scanning fluorimetry and circular dichroism spectroscopy. In contrast to our previous report for another H. pylori adhesin (BabA), the 6K tag did not enhance recombinant protein yield or solubility. Both versions of LabA, with or without the 6K tag, were expressed and isolated from the periplasmic space of Escherichia coli, with a surprisingly high yield of at least 40 mg/L for each independent preparation, following a two-step purification protocol. The proteins were analyzed with mass spectrometry (MS). Unlike its reported effect on stability of BabA, the 6K tag did not appear to protect the N-term of recombinant LabA from partial periplasmic degradation.


Assuntos
Adesinas Bacterianas/metabolismo , Helicobacter pylori/metabolismo , Adesinas Bacterianas/genética , Adesinas Bacterianas/isolamento & purificação , Clonagem Molecular , Escherichia coli , Helicobacter pylori/genética , Hexosaminidase A/metabolismo , Lactose/análogos & derivados , Lactose/metabolismo , Lisina/metabolismo , Espectrometria de Massas , Modelos Moleculares , Periplasma , Ligação Proteica , Estabilidade Proteica , Estrutura Secundária de Proteína
3.
BMJ Case Rep ; 11(1)2018 Dec 13.
Artigo em Inglês | MEDLINE | ID: mdl-30567231

RESUMO

Lysosomal storage disorders or lipidoses are a wide spectrum of inherited diseases caused by deficiency of a specific lysosomal hydrolase. About 134 mutations have been described so far and this number is gradually increasing with newer mutations being reported. We report a 28-month-old child who presented to us with neurodevelopment regression, seizures and cherry red spot in both eyes. His hexosaminidase A enzyme activity was reduced and genetic testing revealed a homozygous novel variation in HEXA (hexosaminidase A) gene in the DNA sample of the patient.


Assuntos
Hexosaminidase A/genética , Mutação , Doença de Tay-Sachs/genética , Pré-Escolar , Humanos , Índia , Masculino
4.
J Mol Med (Berl) ; 96(12): 1359-1373, 2018 12.
Artigo em Inglês | MEDLINE | ID: mdl-30341570

RESUMO

Tay-Sachs disease (TSD) is a lethal lysosomal storage disease (LSD) caused by mutations in the HexA gene, which can lead to deficiency of ß-hexosaminidase A (HexA) activity and consequent accumulation of its substrate, GM2 ganglioside. Recent reports that progranulin (PGRN) functions as a chaperone of lysosomal enzymes and its deficiency is associated with LSDs, including Gaucher disease and neuronal ceroid lipofuscinosis, prompted us to screen the effects of recombinant PGRN on lysosomal storage in fibroblasts from 11 patients affected by various LSDs, which led to the isolation of TSD in which PGRN demonstrated the best effects in reducing lysosomal storage. Subsequent in vivo studies revealed significant GM2 accumulation and the existence of typical TSD cells containing zebra bodies in both aged and ovalbumin-challenged adult PGRN-deficient mice. In addition, HexA, but not HexB, was aggregated in PGRN-deficient cells. Furthermore, recombinant PGRN significantly reduced GM2 accumulation and lysosomal storage in these animal models. Mechanistic studies indicated that PGRN bound to HexA through granulins G and E domain and increased the enzymatic activity and lysosomal delivery of HexA. More importantly, Pcgin, an engineered PGRN derivative bearing the granulin E domain, also effectively bound to HexA and reduced the GM2 accumulation. Collectively, these studies not only provide new insights into the pathogenesis of TSD but may also have implications for developing PGRN-based therapy for this life-threatening disorder. KEY MESSAGES: GM2 accumulation and the existence of typical TSD cells containing zebra bodies are detected in both aged and ovalbumin-challenged adult PGRN deficient mice. Recombinant PGRN significantly reduces GM2 accumulation and lysosomal storage both in vivo and in vitro, which works through increasing the expression and lysosomal delivery of HexA. Pcgin, an engineered PGRN derivative bearing the granulin E domain, also effectively binds to to HexA and reduces GM2 accumulation.


Assuntos
Gangliosídeos/metabolismo , Hexosaminidase A/metabolismo , Lisossomos/metabolismo , Progranulinas/metabolismo , Doença de Tay-Sachs/metabolismo , Animais , Encéfalo/metabolismo , Modelos Animais de Doenças , Fibroblastos/efeitos dos fármacos , Fibroblastos/metabolismo , Células HEK293 , Humanos , Camundongos , Camundongos Knockout , Progranulinas/genética , Células RAW 264.7 , Proteínas Recombinantes/farmacologia
5.
Orphanet J Rare Dis ; 13(1): 152, 2018 09 17.
Artigo em Inglês | MEDLINE | ID: mdl-30220252

RESUMO

BACKGROUND: Tay-Sachs disease (TSD) is a rare neurodegenerative disorder caused by autosomal recessive mutations in the HEXA gene on chromosome 15 that encodes ß-hexosaminidase. Deficiency in HEXA results in accumulation of GM2 ganglioside, a glycosphingolipid, in lysosomes. Currently, there is no effective treatment for TSD. RESULTS: We generated induced pluripotent stem cells (iPSCs) from two TSD patient dermal fibroblast lines and further differentiated them into neural stem cells (NSCs). The TSD neural stem cells exhibited a disease phenotype of lysosomal lipid accumulation. The Tay-Sachs disease NSCs were then used to evaluate the therapeutic effects of enzyme replacement therapy (ERT) with recombinant human Hex A protein and two small molecular compounds: hydroxypropyl-ß-cyclodextrin (HPßCD) and δ-tocopherol. Using this disease model, we observed reduction of lipid accumulation by employing enzyme replacement therapy as well as by the use of HPßCD and δ-tocopherol. CONCLUSION: Our results demonstrate that the Tay-Sachs disease NSCs possess the characteristic phenotype to serve as a cell-based disease model for study of the disease pathogenesis and evaluation of drug efficacy. The enzyme replacement therapy with recombinant Hex A protein and two small molecules (cyclodextrin and tocopherol) significantly ameliorated lipid accumulation in the Tay-Sachs disease cell model.


Assuntos
Células-Tronco Neurais/citologia , Doença de Tay-Sachs/tratamento farmacológico , Doença de Tay-Sachs/terapia , 2-Hidroxipropil-beta-Ciclodextrina/uso terapêutico , Diferenciação Celular/fisiologia , Linhagem Celular , Terapia de Reposição de Enzimas/métodos , Feminino , Imunofluorescência , Gangliosidoses GM2/metabolismo , Hexosaminidase A/metabolismo , Humanos , Células-Tronco Pluripotentes Induzidas/citologia , Células-Tronco Pluripotentes Induzidas/fisiologia , Masculino , Repetições de Microssatélites/genética , Células-Tronco Neurais/metabolismo , Células-Tronco Neurais/fisiologia , Pichia/metabolismo , Espectrometria de Massas em Tandem , Doença de Tay-Sachs/genética , Doença de Tay-Sachs/metabolismo , Tocoferóis/uso terapêutico
6.
Orphanet J Rare Dis ; 13(1): 130, 2018 08 03.
Artigo em Inglês | MEDLINE | ID: mdl-30075786

RESUMO

BACKGROUND: Infantile Sandhoff disease (ISD) is a GM2 gangliosidosis that is classified as a lysosomal storage disorder. The most common symptoms of affected individuals at presentation are neurologic involvement. Here we report clinical course and demographic features in a case series of infantile Sandhoff disease. Enzymatically and some genetically proven cases of ISD were extracted from the Iranian Neurometabolic Registry (INMR) in Children's Medical Center, Iran, Tehran from December 2010 to December 2016. RESULT: Twenty five cases of infantile SD (13 female, 12 male) were included in this study. The age range of patients was 9-24 months with a mean of 15.8 months. The consanguinity rate of parents affected families was about 80%. The mean age of patients at disease onset was 6.4 months and the mean age at diagnosis was 14 months. Patients were diagnosed with a mean delay of 7.8 months. Eleven of patients died due to aspiration pneumonia and intractable seizure. The most common features at presentation (92%) were developmental delay or regression in speech and cognitive domains. Cherry red spots were detected in 17 patients (68%). Organomegaly was detected only in two patients. Enzyme studies showed marked reductions of both Hexosaminidase A and B in all patients. HEXB gene mutation studies performed in eight patients identified 6 different mutations, which five of them were novel. CONCLUSION: Infantile SD should be considered for each child presented with neurologic symptoms such as developmental delay and regression and cherry red spots in ophthalmic examination. Organomegaly is not a frequent clinical finding in infantile SD. Additionally; there are a genetic heterogenisity among Iranian patients.


Assuntos
Mutação/genética , Doença de Sandhoff/genética , Doença de Sandhoff/patologia , Pré-Escolar , Feminino , Hexosaminidase A/genética , Humanos , Lactente , Irã (Geográfico) , Masculino , Cadeia beta da beta-Hexosaminidase/genética
8.
Org Biomol Chem ; 15(44): 9297-9304, 2017 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-28959811

RESUMO

The affinity of a series of iminosugar-based inhibitors exhibiting various ring sizes toward Hex A and their essential interactions with the enzyme active site were investigated. All the Hex A-inhibiting iminosugars tested formed hydrogen bonds with Arg178, Asp322, Tyr421 and Glu462 and had the favorable cation-π interaction with Trp460. Among them, DMDP amide (6) proved to be the most potent competitive inhibitor with a Ki value of 0.041 µM. We analyzed the dynamic properties of both DMDP amide (6) and DNJNAc (1) in aqueous solution using molecular dynamics (MD) calculations; the distance of the interaction between Asp322 and 3-OH and Glu323 and 6-OH was important for stable interactions with Hex A, reducing fluctuations in the plasticity of the active site. DMDP amide (6) dose-dependently increased intracellular Hex A activity in the G269S mutant cells and restored Hex A activity up to approximately 43% of the wild type level; this effect clearly exceeded the border line treatment for Tay-Sachs disease, which is regarded as 10-15% of the wild type level. This is a significantly greater effect than that of pyrimethamine, which is currently in Phase 2 clinical trials. DMDP amide (6), therefore, represents a new promising pharmacological chaperone candidate for the treatment of Tay-Sachs disease.


Assuntos
Domínio Catalítico , Simulação por Computador , Hexosaminidase A/metabolismo , Açúcares/metabolismo , Açúcares/farmacologia , Doença de Tay-Sachs/tratamento farmacológico , Inibidores Enzimáticos/química , Inibidores Enzimáticos/metabolismo , Inibidores Enzimáticos/farmacologia , Inibidores Enzimáticos/uso terapêutico , Hexosaminidase A/antagonistas & inibidores , Hexosaminidase A/química , Hexosaminidase A/genética , Humanos , Simulação de Dinâmica Molecular , Mutação , Açúcares/química , Açúcares/uso terapêutico
9.
Annu Rev Med ; 68: 445-458, 2017 01 14.
Artigo em Inglês | MEDLINE | ID: mdl-28099085

RESUMO

Several proteins that are mutated in lysosomal storage diseases are linked to neurodegenerative disease. This review focuses on some of these lysosomal enzymes and transporters, as well as current therapies that have emerged from the lysosomal storage disease field. Given the deeper genetic understanding of lysosomal defects in neurodegeneration, we explore why some of these orphan disease drug candidates are also attractive targets in subpopulations of individuals with neurodegenerative disease.


Assuntos
Doenças por Armazenamento dos Lisossomos/tratamento farmacológico , Doenças por Armazenamento dos Lisossomos/genética , Lisossomos/enzimologia , Doenças Neurodegenerativas/genética , Proteínas/genética , Acetilglucosaminidase/genética , Proteínas Amiloidogênicas/metabolismo , Autofagia , Proteínas de Transporte/genética , Endocitose , Glucosilceramidase/genética , Hexosaminidase A/genética , Hexosaminidase B/genética , Humanos , Doenças por Armazenamento dos Lisossomos/complicações , Doenças por Armazenamento dos Lisossomos/metabolismo , Glicoproteínas de Membrana/genética , Proteínas/metabolismo , ATPases Translocadoras de Prótons/genética , Esfingomielina Fosfodiesterase/genética
10.
Brain Res ; 1657: 52-61, 2017 02 15.
Artigo em Inglês | MEDLINE | ID: mdl-27923633

RESUMO

Niemann-Pick disease Type C1 (NPC1) is a rare progressive neurodegenerative disorder caused by mutations in the NPC1 gene. On the cellular level NPC1 mutations lead to an accumulation of cholesterol and gangliosides. As a thorough analysis of the severely affected neuronal cells is unfeasible in NPC1 patients, we recently described the cellular phenotype of neuronal cells derived from NPC1 patient iPSCs carrying the compound heterozygous mutation c.1836A>C/c.1628delC. Here we expanded the analysis to cell lines carrying the prevalent mutation c.3182T>C and the novel mutation c.1180T>C, as well as to the determination of GM2 and GM3 gangliosides in NPC1 patient-specific iPSC-derived neurons and glia cells. Immunocytochemical detection of GM2 revealed punctated staining pattern predominantly localized in neurons. Detection of cholesterol by filipin staining showed a comparable staining pattern, colocalized with GM2, indicating a deposit of GM2 and cholesterol in the same cellular compartments. Accumulations were not only restricted to cell bodies, but were also found in the neuronal extensions. A quantification of the GM2 amount by HPLC-MS/MS confirmed significantly higher amounts in neurons carrying a mutation. Additionally, these cells displayed a lowered activity of the catabolic enzyme Hex A, but not B4GALNT1. Molecular docking simulations indicated binding of cholesterol to Hex A, suggesting cholesterol influences the GM2 degradation pathway and, subsequently, leading to the accumulation of GM2. Taken together, this is the first study showing an accumulation of GM2 in neuronal derivatives of patient-specific iPSCs and thus proving further disease-specific hallmarks in this human in vitro model of NPC1.


Assuntos
Colesterol/metabolismo , Gangliosídeo G(M2)/metabolismo , Células-Tronco Pluripotentes Induzidas/metabolismo , Doença de Niemann-Pick Tipo C/metabolismo , Proteínas de Transporte/genética , Proteínas de Transporte/metabolismo , Células Cultivadas , Gangliosídeo G(M3)/metabolismo , Hexosaminidase A/metabolismo , Humanos , Células-Tronco Pluripotentes Induzidas/patologia , Glicoproteínas de Membrana/genética , Glicoproteínas de Membrana/metabolismo , Simulação de Acoplamento Molecular , Mutação , Células-Tronco Neurais/metabolismo , Células-Tronco Neurais/patologia , Neuroglia/metabolismo , Neuroglia/patologia , Neurônios/metabolismo , Neurônios/patologia , Doença de Niemann-Pick Tipo C/genética , Doença de Niemann-Pick Tipo C/patologia
11.
Mol Biol Cell ; 27(24): 3813-3827, 2016 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-27682588

RESUMO

Loss of function of the enzyme ß-hexosaminidase A (HexA) causes the lysosomal storage disorder Tay-Sachs disease (TSD). It has been proposed that mutations in the α chain of HexA can impair folding, enzyme assembly, and/or trafficking, yet there is surprisingly little known about the mechanisms of these potential routes of pathogenesis. We therefore investigated the biosynthesis and trafficking of TSD-associated HexA α mutants, seeking to identify relevant cellular quality control mechanisms. The α mutants E482K and G269S are defective in enzymatic activity, unprocessed by lysosomal proteases, and exhibit altered folding pathways compared with wild-type α. E482K is more severely misfolded than G269S, as observed by its aggregation and inability to associate with the HexA ß chain. Importantly, both mutants are retrotranslocated from the endoplasmic reticulum (ER) to the cytosol and are degraded by the proteasome, indicating that they are cleared via ER-associated degradation (ERAD). Leveraging these discoveries, we observed that manipulating the cellular folding environment or ERAD pathways can alter the kinetics of mutant α degradation. Additionally, growth of patient fibroblasts at a permissive temperature or with chemical chaperones increases cellular Hex activity by improving mutant α folding. Therefore modulation of the ER quality control systems may be a potential therapeutic route for improving some forms of TSD.


Assuntos
Hexosaminidase A/genética , Hexosaminidase A/metabolismo , Retículo Endoplasmático/metabolismo , Degradação Associada com o Retículo Endoplasmático/fisiologia , Células HEK293 , Hexosaminidase A/biossíntese , Hexosaminidase A/fisiologia , Humanos , Lisossomos/metabolismo , Chaperonas Moleculares/metabolismo , Mutação , Cultura Primária de Células , Transporte Proteico/fisiologia , Proteólise , Doença de Tay-Sachs/genética , Doença de Tay-Sachs/metabolismo , beta-N-Acetil-Hexosaminidases/metabolismo
12.
Mol Neurobiol ; 53(4): 2287-96, 2016 May.
Artigo em Inglês | MEDLINE | ID: mdl-25976368

RESUMO

Abnormalities in lysosomal function have been reported in diabetes, aging, and age-related degenerative diseases. These lysosomal abnormalities are an early manifestation of neurodegenerative diseases and often precede the onset of clinical symptoms such as learning and memory deficits; however, the mechanism underlying lysosomal dysfunction is not known. In the current study, we investigated the mechanism underlying lysosomal dysfunction in the cortex and hippocampi, key structures involved in learning and memory, of a type 2 diabetes (T2D) mouse model, the leptin receptor deficient db/db mouse. We demonstrate for the first time that diabetes leads to destabilization of lysosomes as well as alterations in the protein expression, activity, and/or trafficking of two lysosomal enzymes, hexosaminidase A and cathepsin D, in the hippocampus of db/db mice. Pioglitazone, a thiazolidinedione (TZD) commonly used in the treatment of diabetes due to its ability to improve insulin sensitivity and reverse hyperglycemia, was ineffective in reversing the diabetes-induced changes on lysosomal enzymes. Our previous work revealed that pioglitazone does not reverse hypercholesterolemia; thus, we investigated whether cholesterol plays a role in diabetes-induced lysosomal changes. In vitro, cholesterol promoted the destabilization of lysosomes, suggesting that lysosomal-related changes associated with diabetes are due to elevated levels of cholesterol. Since lysosome dysfunction precedes neurodegeneration, cognitive deficits, and Alzheimer's disease neuropathology, our results may provide a potential mechanism that links diabetes with complications of the central nervous system.


Assuntos
Encéfalo/metabolismo , Encéfalo/patologia , Colesterol/metabolismo , Diabetes Mellitus Tipo 2/patologia , Lisossomos/patologia , Animais , Catepsina D/metabolismo , Córtex Cerebral/enzimologia , Córtex Cerebral/patologia , Diabetes Mellitus Tipo 2/complicações , Diabetes Mellitus Tipo 2/enzimologia , Fluorescência , Glucose/metabolismo , Hexosaminidase A/metabolismo , Hipocampo/enzimologia , Concentração de Íons de Hidrogênio , Hiperglicemia/complicações , Hiperglicemia/patologia , Membranas Intracelulares/metabolismo , Camundongos , Oxirredução , Fenótipo , Pioglitazona , Coloração e Rotulagem , Tiazolidinedionas/farmacologia
13.
Orphanet J Rare Dis ; 10: 45, 2015 Apr 17.
Artigo em Inglês | MEDLINE | ID: mdl-25896637

RESUMO

BACKGROUND: Late Onset Tay- Sachs disease (LOTS) is a rare neurodegenerative lysosomal storage disease which results from mutations in the gene encoding the α subunit (HEXA) of ß-hexosaminidase enzyme (HexA). At the present time, no effective treatment exists for LOTS and other neurodegenerative diseases involving the central nerve system (CNS). Pyrimethamine (PMT) was previously shown to act as a HexA chaperone in human fibroblasts in vitro carrying some (e.g., αG269S), but not all LOTS-related mutations. The present study assessed the effect of cyclic, low dose and long term pyrimethamine treatment on HexA in subjects with LOTS. METHODS: In an open label trial in 4 LOTS patients, PMT was initiated at an average daily dose of ~2.7 mg and administered cyclically guided by blood lymphocyte HexA activity for a mean duration of 82.8 (±22.5; SD) weeks (~1.5 year). RESULTS: HexA activity rose in all subjects, with a mean peak increase of 2.24 folds (±0.52; SD) over baseline activity (range 1.87-3). The mean treatment time required to attain this peak was of 15.7 (±4.8; SD) weeks. Following increase in activity, HexA gradually declined with the continued use of PMT, which was then stopped, resulting in the return of HexA activity to baseline. A second cycle of PMT treatment was then initiated, resulting again in an increase in HexA activity. Three of the patients experienced a measurable neuropsychiatric deterioration whereas one subject remained entirely stable. CONCLUSIONS: Cyclic low dose of PMT can increase HexA activity in LOTS patients. However, the observed increase is repeatedly transient and not associated with discernible beneficial neurological or psychiatric effects.


Assuntos
Pirimetamina/administração & dosagem , Pirimetamina/uso terapêutico , Doença de Tay-Sachs/tratamento farmacológico , Adulto , Relação Dose-Resposta a Droga , Esquema de Medicação , Regulação Enzimológica da Expressão Gênica , Hexosaminidase A/genética , Hexosaminidase A/metabolismo , Humanos , Masculino , Projetos Piloto , Adulto Jovem
14.
Muscle Nerve ; 52(1): 83-7, 2015 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-25736958

RESUMO

INTRODUCTION: The clinical diagnosis of amyotrophic lateral sclerosis (ALS) relies on exclusion of mimic syndromes, but there are no specific guidelines regarding the extent of laboratory testing required. METHODS: A survey was sent to 274 physicians listed in the Neuromuscular Section of the American Academy of Neurology. The survey asked how often they order 21 different laboratory tests in patients suspected of having ALS. RESULTS: Ninety-nine responses were received (36% response rate). Greater than 75% ordered serum creatine kinase, chemistry panel, and thyroid functions often or always. Fewer than 25% tested for serum complement, hexosaminidase A, spinal muscular atrophy, Kennedy disease, heavy metals, or human T-cell lymphotrophic virus often or always. Twelve other tests had intermediate responses. CONCLUSIONS: There is a lack of consensus among respondents regarding the laboratory evaluation of suspected ALS. Prospective studies are needed to define the diagnostic yield and cost-effectiveness of laboratory testing in this population.


Assuntos
Técnicas de Laboratório Clínico/métodos , Doença dos Neurônios Motores/diagnóstico , Médicos , Creatina Quinase/sangue , Coleta de Dados , Diagnóstico Diferencial , Feminino , Hexosaminidase A/sangue , Humanos , Masculino , Doença dos Neurônios Motores/sangue
16.
Zhonghua Er Ke Za Zhi ; 52(4): 313-6, 2014 Apr.
Artigo em Chinês | MEDLINE | ID: mdl-24915922

RESUMO

OBJECTIVE: To explore the clinical features and molecular mutation of HEXB gene in a case with juvenile Sandhoff disease. METHOD: We retrospectively reviewed the clinical, neuroimaging and biochemical findings in this Chinese child with juvenile Sandhoff disease. Hexosaminidase A and hexosaminidase A & B activities were measured in blood leukocytes by fluorometric assay. HEXB gene molecular analysis was performed by PCR and direct sequencing. RESULT: The 9-year-old boy was admitted for psychomotor regression. He presented slowly progressive gait disorder and dysarthria during the last three years. Cranial MRI revealed a marked cerebellar atrophy with normal intensity in the thalamus and basal ganglia. Brain MRS showed normal in the thalamus and basal ganglia. Hexosaminidase A was 69.5 (mg·h) [normal controls 150-360 nmol/(mg·h)], hexosaminidase A & B activity was 119 nmol/(mg·h)[normal controls 600-3 500 nmol/(mg·h)], confirming the diagnosis of Sandhoff disease. The patient was a compound heterozygote for a novel deletion mutation c.1404delT (p. P468P fsX62) and a reported mutation c.1509-26G>A. CONCLUSION: The clinical features of juvenile Sandhoff disease include ataxia, dysarthria and cerebellar atrophy. The enzyme assay and molecular analysis of HEXB gene can confirm the diagnosis of Sandhoff disease. The novel mutation c.1404delT(p. P468P fsX62) is a disease-related mutation.


Assuntos
Mutação , Doença de Sandhoff/diagnóstico , Doença de Sandhoff/genética , Cadeia beta da beta-Hexosaminidase/genética , Encéfalo/diagnóstico por imagem , Encéfalo/patologia , Ataxia Cerebelar/diagnóstico , Ataxia Cerebelar/enzimologia , Ataxia Cerebelar/genética , Criança , Análise Mutacional de DNA , Heterozigoto , Hexosaminidase A/sangue , Hexosaminidase A/metabolismo , Hexosaminidase B/sangue , Hexosaminidase B/metabolismo , Humanos , Leucócitos/enzimologia , Imagem por Ressonância Magnética , Masculino , Radiografia , Estudos Retrospectivos , Doença de Sandhoff/enzimologia
17.
Otolaryngol Pol ; 68(1): 20-4, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24484945

RESUMO

UNLABELLED: Nasal polyps and hypertrophic lower nasal conchae are common disorders of nasal cavity. The majority of etiopathogenetic theories indicate inflammatory background of polyps and hypertrophic concha. N-acetyl-ß-D-hexosaminidase and ß-glucuronidase are lysosomal exoglycosidases revealing accelerated activity in inflammatory processes. AIM: The aim of the study was to evaluate the catabolism of glycoconjugates in nasal polyps and hypertrophic nasal concha basing on the activity of N-acetyl-ß-D-hexosaminidase (HEX) and ß-glucuronidase (GLU). MATERIAL AND METHODS: Material consisted of nasal polyps taken from 40 patients during polypectomy in patients with chronic rhinosinusitis with nasal polyps (CRSwNP) and hypertrophic lower nasal conchae taken from 20 patients during mucotomy. The activity of HEX, HEX A, HEX B and GLU in supernatant of homogenates of nasal polyps and hypertrophic lower nasal concha tissues has been estimated using colorimetric method. RESULTS: Statistically significant decrease has been observed in concentration of the activity (per 1mg of tissue) of HEX (p<0.05), HEX B (p<0.001) and specific activity (per 1mg of protein) of HEX B (p<0.001) in nasal polyps tissue in comparison to hypertrophic lower nasal conchae tissue. CONCLUSIONS: Decrease in the activity and specific activity concentration of the majority of examined lysosomal exoglycosidases (increasing in inflammations) in comparison to hypertrophic lower nasal conchae suggests electrolytes disorders and questions the inflammatory background of nasal polyps.


Assuntos
Glucuronidase/metabolismo , Hexosaminidase A/metabolismo , Hexosaminidase B/metabolismo , Pólipos Nasais/enzimologia , Conchas Nasais/enzimologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Hipertrofia/enzimologia , Masculino , Pessoa de Meia-Idade , Conchas Nasais/patologia , Adulto Jovem
18.
Dis Markers ; 35(5): 457-63, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-24288426

RESUMO

BACKGROUND: Severe periodontitis leading to tooth loss is found in 5-15% of most populations worldwide. AIM: The applicability of salivary ß -hexosaminidase (ß-HEX A%, percentage of ß-HEX A isoenzyme to total ß-HEX) and ß-HEX B% (ß-HEX B/ß-HEX) indexes was investigated as a possible marker of periodontitis. METHODS: Thirty three alcohol-dependent smokers (AS) and 32 healthy controls (C) were enrolled in the study. The activity of ß-HEX was measured spectrophotometrically. RESULTS: ß-HEX A% was significantly higher and ß-HEX B% was lower in AS than in C group. We found a significant correlation between ß-HEX A% and gingival index (GI) and an inverse correlation between ß-HEX A% and salivary flow (SF), in all groups. Salivary ß-HEX A% index in smoking alcoholics at 0.23 had excellent sensitivity (96%) and specificity (91%); the AUC for ß-HEX A% was high (0.937). There were no correlations between amount/duration-time of alcohol drinking/smoking and ß-HEX A% or ß-HEX B%. We found significant correlations between the time period of denture wearing and GI, papilla bleeding index (PBI), and decayed missing filled teeth index (DMFT) and between GI and the amount of smoked cigarettes per day. CONCLUSION: Bad periodontal state was most likely due to the nicotine dependence. Salivary ß-HEX A% is a promising excellent marker for the diagnosis of periodontitis.


Assuntos
Alcoolismo/complicações , Hexosaminidase A/análise , Periodontite/diagnóstico , Saliva/química , Adulto , Biomarcadores/análise , Estudos de Casos e Controles , Feminino , Humanos , Masculino , Periodontite/complicações , Periodontite/enzimologia , Saliva/enzimologia , Sensibilidade e Especificidade , Fumar
19.
Gene ; 527(2): 679-82, 2013 Sep 25.
Artigo em Inglês | MEDLINE | ID: mdl-23820084

RESUMO

A case of late onset GM2 gangliosidodis with spinal muscular atrophy phenotype followed by cerebellar and extrapyramidal symptoms is presented. Genetic analysis revealed compound heterozygous mutation in exon 10 of the HEXA gene. Patient has normal intelligence and emotional reactivity. Neuroimaging tests of the brain showed only cerebellar atrophy consistent with MR spectroscopy (MRS) abnormalities. (18)F-fluorodeoxyglucose positron emission tomography (18)F-FDG PET/CT of the brain revealed glucose hypometabolism in cerebellum and in temporal and occipital lobes bilaterally.


Assuntos
Gangliosidoses GM2/diagnóstico , Atrofia Muscular Espinal/diagnóstico , Adulto , Diagnóstico Diferencial , Gangliosidoses GM2/genética , Heterozigoto , Hexosaminidase A/genética , Humanos , Imagem por Ressonância Magnética , Masculino , Mutação
20.
Pol Merkur Lekarski ; 34(203): 259-62, 2013 May.
Artigo em Polonês | MEDLINE | ID: mdl-23894776

RESUMO

UNLABELLED: Parenteral nutrition entails numerous metabolic complications resulting from food bypass of the gastrointestinal tract. Up to now have not been established all complications of parenteral nutrition, despite intensive research and clinical observations. Knowledge of the biochemical changes resulting from parenteral nutrition is essential to effective prevention, early detection and effective treatment of the metabolic disorders induced by parenteral nutrition. The aim of the study was to evaluate the catabolism of glycoconjugates of parenterally fed patients, reflected by the activity of N-acetyl-beta-D-hexosaminidase (HEX): HEX A and HEX B isoenzymes in serum and urine. MATERIAL AND METHODS: Samples of blood and urine were collected from 23 patients: before intravenous alimentation, at start, as well as of fifth and tenth day of parenteral nutrition. The activity of HEX A and HEX B in serum and urine was determined by the colorimetric method of Zwierz et al. as modified by Marciniak et al. The activity of urinary HEXA and HEX B has been calculated per 1 mg of creatinine. RESULTS: The activity of serum HEXA significantly decreased at fifth day, in comparison to the activity before parenteral alimentation, and significantly increased at tenth day of parenteral nutrition. The activity of HEX B in serum increased significantly at fifth and tenth day of the parenteral nutrition. CONCLUSIONS: Parenteral nutrition alter the catabolism of glycoconjugates, reflected by significant changes in serum HEX A and HEX B activities. Urine was the not appropriate material to evaluate the catabolism of glycoconjugates in view of HEX A and HEX B activities.


Assuntos
Hexosaminidase A/sangue , Hexosaminidase A/urina , Hexosaminidase B/sangue , Hexosaminidase B/urina , Nutrição Parenteral , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Doenças Metabólicas/etiologia , Doenças Metabólicas/metabolismo , Doenças Metabólicas/prevenção & controle , Pessoa de Meia-Idade , Nutrição Parenteral/efeitos adversos , Adulto Jovem
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