RESUMO
Most glycosyltransferases show remarkable gross and fine substrate specificity, which is reflected in the old one enzyme-one linkage paradigm. While human Gb3/CD77 synthase is a glycosyltransferase that synthesizes the Galα1â4Gal moiety mainly on glycosphingolipids, its pigeon homolog prefers glycoproteins as acceptors. In this study, we characterized two Gb3/CD77 synthase paralogs found in pigeons (Columba livia). We evaluated their specificities in transfected human teratocarcinoma 2102Ep cells by flow cytofluorometry, Western blotting, high-performance thin-layer chromatography, mass spectrometry and metabolic labelling with 14C-galactose. We found that the previously described pigeon Gb3/CD77 synthase (called P) can use predominately glycoproteins as acceptors, while its paralog (called M), which we serendipitously discovered while conducting this study, efficiently synthesizes Galα1â4Gal caps on both glycoproteins and glycosphingolipids. These two paralogs may underlie the difference in expression profiles of Galα1â4Gal-terminated glycoconjugates between neoavians and mammals.
Assuntos
Aves/metabolismo , Galactosiltransferases/metabolismo , Glicoproteínas/metabolismo , Glicoesfingolipídeos/metabolismo , Animais , Galactosiltransferases/genética , Expressão Gênica , Glicoproteínas/genética , Glicosilação , Humanos , Especificidade por SubstratoRESUMO
N-glycosylation is one of the most important posttranslational modifications of proteins. It plays important roles in the biogenesis and functions of proteins by influencing their folding, intracellular localization, stability and solubility. N-glycans are synthesized by glycosyltransferases, a complex group of ubiquitous enzymes that occur in most kingdoms of life. A growing body of evidence shows that N-glycans may influence processing and functions of glycosyltransferases, including their secretion, stability and substrate/acceptor affinity. Changes in these properties may have a profound impact on glycosyltransferase activity. Indeed, some glycosyltransferases have to be glycosylated themselves for full activity. N-glycans and glycosyltransferases play roles in the pathogenesis of many diseases (including cancers), so studies on glycosyltransferases may contribute to the development of new therapy methods and novel glycoengineered enzymes with improved properties. In this review, we focus on the role of N-glycosylation in the activity of glycosyltransferases and attempt to summarize all available data about this phenomenon.
Assuntos
Glicosiltransferases/química , Polissacarídeos/metabolismo , Glicosilação , Glicosiltransferases/metabolismo , Humanos , Polissacarídeos/química , Processamento de Proteína Pós-TraducionalRESUMO
BACKGROUND: Major symptoms of chronic obstructive pulmonary disease (COPD) are chronic bronchitis and emphysema leading from lung tissue destruction, that is an effect of an imbalance between metalloproteinases (MMPs) and their tissue inhibitors activity. As potential factor involved in this COPD pathogenesis, MMP-12 is considered. We investigated the role of genetic polymorphism and protein level of MMP-12 in the COPD development among Poles. METHODS: We analyzed - 82 A > G SNP in the promoter region of MMP-12 gene (rs2276109) among 335 smoked COPD patients and 309 healthy individuals, including 110 smokers. Additionally, 60 COPD patients and 61 controls (23 smokers) were tested for serum levels of MMP-12 using ELISA. All subjects were analyzed for lung function using spirometry (FEV1% and FEV1/FVC parameters). RESULTS: We observed that -82G allele and -82GG homozygous genotype frequencies of the SNP rs2276109 were significantly lower in COPD patients than in controls (12.5% vs 16.9%, respectively; χ2 = 4.742, p = 0.02 for allele and 0.5% vs 3.9%, respectively; χ2 = 9.0331, p = 0.01 for genotype). Moreover, -82G allele was more frequent in controls smokers than in non-smokers (22.3% vs 14.1%, χ2 = 6.7588, p = 0.01). Serum level of MMP-12 was significantly higher in COPD patients than in controls groups (6.8 ng/ml vs 3.3 ng/ml, respectively; F = 7.433, p < 0.0001), although independently of analyzed gene polymorphisms. Additionally, no correlation between parameters of lung function (FEV1% and FEV1/FVC) and protein level was found. CONCLUSIONS: We found that -82G allele of SNP rs2276109 was associated with reduced risk of COPD, and COPD patients released more MMP-12 than healthy individuals, but independently on this SNP.
Assuntos
Metaloproteinase 12 da Matriz/sangue , Metaloproteinase 12 da Matriz/genética , Polimorfismo de Nucleotídeo Único , Doença Pulmonar Obstrutiva Crônica/genética , Fumar/genética , Alelos , Estudos de Casos e Controles , Feminino , Estudos de Associação Genética , Predisposição Genética para Doença , Humanos , Masculino , Polônia , Regiões Promotoras Genéticas , Doença Pulmonar Obstrutiva Crônica/sangue , Doença Pulmonar Obstrutiva Crônica/induzido quimicamente , Fumar/efeitos adversosRESUMO
PURPOSE: Identify children at greatest risk for dog bite injuries and to provide injury prevention recommendations. METHODS: A retrospective review of patients aged ≤18â¯years treated for dog bite injuries from October 2011 to October 2016 was performed. Data collected included patient demographics, parental presence, time of injury, dog breed and ownership status, injury location and characteristics, need for operative intervention, and hospitalization. RESULTS: One-hundred and two patients met the inclusion criteria. The mean age was 5.84â¯years, and 43.1% were preschool-aged (2-5â¯years). Parental presence was reported in 43.6% of cases, and most attacks occurred in the evening (46.8%). Injuries often involved the head-neck region (92.1%), and 72.5% were of major severity. Pet dogs were responsible for 42% of injuries, and pit bull was the most-identified breed (36.2%). Most injuries occurred while the child was at home (57.8%) and was petting or playing with the dog (28.4%). Intervention in the operating room was required in 34.3% of patients. Major injury was more likely to require operative intervention (pâ¯=â¯0.015) but was not associated with patient age, sex, pet status, or the need for hospitalization. CONCLUSIONS: Preschool-aged children are more likely to be injured by dog bites, and dog bites can result in major injury to the head and neck region. Prevention efforts should focus on dog training, public education (children and adults), vigilant adult supervision, and a zero-tolerance policy. LEVEL OF CLINICAL EVIDENCE: Level IV-case series with no comparison group. TYPE OF STUDY: Prognostic.
Assuntos
Prevenção de Acidentes , Mordeduras e Picadas , Tratamento de Emergência/estatística & dados numéricos , Educação em Saúde/organização & administração , Pais/educação , Animais , Sistema de Vigilância de Fator de Risco Comportamental , Mordeduras e Picadas/epidemiologia , Mordeduras e Picadas/prevenção & controle , Mordeduras e Picadas/terapia , Criança , Pré-Escolar , Cães , Feminino , Conhecimentos, Atitudes e Prática em Saúde , Hospitalização/estatística & dados numéricos , Humanos , Lactente , Escala de Gravidade do Ferimento , Masculino , Estudos Retrospectivos , Texas/epidemiologiaRESUMO
The objective of this study was to identify a normalizer or combination of normalizers for quantitative evaluation of the expression of a target gene of interest during melanoma progression. Adult melanocytes, uveal primary melanoma cells and cutaneous primary and metastatic melanoma cells were used to construct a panel of 14 experimental models reflecting cancer promotion and progression. Hypoxanthine phosphoribosyltransferase 1 (HPRT1), glucuronidase beta (GUSB), ribosomal protein S23 (RPS23), phosphoglycerate kinase 1 (PGK1) and small nuclear ribonucleoprotein progression. Adult melanocytes, uveal primary melanoma cells and cutaneous primary and metastatic melanoma cells were used to construct a panel of 14 experimental models reflecting cancer promotion and progression. Hypoxanthine phosphoribosyltransferase 1 (HPRT1), glucuronidase beta (GUSB), ribosomal protein S23 (RPS23), phosphoglycerate kinase 1 (PGK1) and small nuclear ribonucleoprotein polypeptide A (SRNPA) were chosen as candidate housekeeping genes. NormFinder software was used to identify the best reference gene or pair of reference genes from five candidate housekeeping genes, on the basis of expression stability in a given experimental model. The suitability of references was validated by normalizing the transcriptional activities of E-cadherin (CDH1), N-cadherin (CDH2) and endoplasmic reticulum aminopeptidase 1 (ERAP1) target genes. It has been shown that the relative expression of CDH2 and ERAP1 target genes in a given cell line may vary between experimental models, leading to biological misinterpretation. In view of this, we devised a strategy for improved selection of the best stable reference and for obtaining biologically consistent results. This strategy avoided experimental model- and normalizer-dependent conclusions concerning the relative expression of target gene, in the examined cell lines.
Assuntos
Regulação Neoplásica da Expressão Gênica , Genes Essenciais , Melanoma/genética , Proteínas de Neoplasias/genética , Reação em Cadeia da Polimerase em Tempo Real/normas , Neoplasias Uveais/genética , Aminopeptidases/genética , Aminopeptidases/metabolismo , Animais , Antígenos CD/genética , Antígenos CD/metabolismo , Caderinas/genética , Caderinas/metabolismo , Linhagem Celular , Progressão da Doença , Perfilação da Expressão Gênica , Glucuronidase/genética , Glucuronidase/metabolismo , Humanos , Hipoxantina Fosforribosiltransferase/genética , Hipoxantina Fosforribosiltransferase/metabolismo , Melanócitos/citologia , Melanócitos/metabolismo , Melanoma/diagnóstico , Melanoma/metabolismo , Melanoma/patologia , Antígenos de Histocompatibilidade Menor/genética , Antígenos de Histocompatibilidade Menor/metabolismo , Proteínas de Neoplasias/metabolismo , Fosfoglicerato Quinase/genética , Fosfoglicerato Quinase/metabolismo , Cultura Primária de Células , Padrões de Referência , Ribonucleoproteínas Nucleares Pequenas/genética , Ribonucleoproteínas Nucleares Pequenas/metabolismo , Proteínas Ribossômicas/genética , Proteínas Ribossômicas/metabolismo , Neoplasias Uveais/diagnóstico , Neoplasias Uveais/metabolismo , Neoplasias Uveais/patologiaRESUMO
Normocephalic pancraniosynostosis is defined as the premature fusion of 3 or, more major sutures in the absence of another primary etiology, including primary, microcephaly, ventriculoperitoneal shunting, hypothyroidism, rickets, mucopolysaccharidoses, or other lysosomal storage diseases. It is very rare, thus far only 6 patients have been reported in the literature. Patients tend to present much later than those with single sutural, synostoses, and up to half have evidence of elevated intracranial pressure. The authors wish to present another patient, with emphasis on a unique treatment approach.
Assuntos
Craniossinostoses/cirurgia , Criança , Craniossinostoses/diagnóstico por imagem , Craniotomia , Humanos , Masculino , Procedimentos Neurocirúrgicos/métodosRESUMO
BACKGROUND: Prompt identification of significant ocular injuries in patients who sustain an orbital fracture is important to prevent any potential long-term visual sequelae. The true incidence of these injuries has not been determined, however. As a consequence, most surgeons choose to have all patients evaluated by an ophthalmologist. The objective of this study was to conclusively identify the incidence of significant ocular injuries in patients with isolated orbital fractures and to determine their predictors to guide more efficient patient care. METHODS: A prospective cohort study powered to detect a 15% incidence of ocular injuries was designed. All patients presenting to our center with computed tomography findings of an isolated orbital fracture were included and evaluated by plastic surgery and ophthalmology services. Patients were followed up for a minimum of 1 week to identify any delayed injuries. RESULTS: Eighty patients were enrolled from 2012 to 2014. There were 46 men and 34 women with a mean age of 42.8 years. Assault was the most common mechanism of injury. There were 8 ocular injuries (10%): ruptured globe (1), uveal prolapse (1), retrobulbar hemorrhage (2), hyphema (2), hemorrhagic glaucoma with hyphema (1), and scleral tear (1). Predictors for significant ocular injuries were grossly abnormal visual acuity and abnormal pupillary reactivity of the affected eye. CONCLUSIONS: The incidence of significant ocular injuries in isolated orbital fractures is lower than previously reported. Patients presenting with grossly abnormal visual acuity or abnormal pupillary reactivity are at high risk and should receive prompt ophthalmology service evaluation.
Assuntos
Traumatismos Oculares/etiologia , Fraturas Orbitárias/complicações , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Criança , Traumatismos Oculares/diagnóstico , Traumatismos Oculares/epidemiologia , Feminino , Seguimentos , Humanos , Incidência , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Fatores de Risco , Adulto JovemRESUMO
Transcription factor EKLF (Erythroid Krüppel-Like Factor) belongs to the group of Krüppellike factors, which regulate proliferation, differentiation, development and apoptosis of mammalian cells. EKLF factor is present in erythroid cells, where it participates in regulation of hematopoiesis, expression of genes encoding transmembrane proteins (including blood group antigens), and heme biosynthesis enzymes. It is also a key factor in downregulation of γ-globins and activation of ß-globin gene expression. The EKLF factor consists of two domains: proline-rich transactivation domain and DNA-binding domain containing three zinc finger motifs, which recognize DNA. EKLF can act as a transcription activator (for example in the case of ß-globin gene) or repressor, which depends on the type of posttranslational modification (phosphorylation, SUMOylation, ubiquitination and acetylation). Mutations in the gene encoding EKLF may cause hemoglobinopathies, such as hereditary persistence of fetal hemoglobin and ß-thalassemia intermedia, and congenital dyserythropoietic anemia type IV, which is a hematopoietic disorder. These changes may impede invasion of red blood cells by malaria merozoites and cause faster removal of invaded erythrocytes. In addition, mutations in KLF1 may decrease the number of erythrocyte surface antigens that belong to blood group systems such as MN, P1PK, Lutheran, Duffy, Diego and OK. Such antigens can be receptors for protozoans (such as Plasmodium falciparum or Plasmodium vivax), bacteria (like uropathogenic strains of Escherichia coli, Neisseria meningitidis), and toxins (Shiga toxins), which may cause several dangerous diseases including malaria, pyelonephritis, hemorrhagic colitis, hemolytic uremic syndrome (HUS) and meningitis. Here, we propose a hypothesis on possible liaisons between mutations in the gene encoding EKLF and resistance to pathogens.
Assuntos
Infecções Bacterianas/imunologia , Resistência à Doença , Fatores de Transcrição Kruppel-Like/genética , Mutação , Doenças Parasitárias/imunologia , Humanos , Fatores de Transcrição Kruppel-Like/imunologiaRESUMO
Human Gb3/CD77 synthase (α1,4-galactosyltransferase) is the only known glycosyltransferase that changes acceptor specificity because of a point mutation. The enzyme, encoded by A4GALT locus, is responsible for biosynthesis of Gal(α1-4)Gal moiety in Gb3 (CD77, Pk antigen) and P1 glycosphingolipids. We showed before that a single nucleotide substitution c.631C > G in the open reading frame of A4GALT, resulting in replacement of glutamine with glutamic acid at position 211 (substitution p. Q211E), broadens the enzyme acceptor specificity, so it can not only attach galactose to another galactose but also to N-acetylgalactosamine. The latter reaction leads to synthesis of NOR antigens, which are glycosphingolipids with terminal Gal(α1-4)GalNAc sequence, never before described in mammals. Because of the apparent importance of position 211 for enzyme activity, we stably transfected the 2102Ep cells with vectors encoding Gb3/CD77 synthase with glutamine substituted by aspartic acid or asparagine, and evaluated the cells by quantitative flow cytometry, high-performance thin-layer chromatography and real-time PCR. We found that cells transfected with vectors encoding Gb3/CD77 synthase with substitutions p. Q211D or p. Q211N did not express Pk, P1 and NOR antigens, suggesting complete loss of enzymatic activity. Thus, amino acid residue at position 211 of Gb3/CD77 synthase is critical for specificity and activity of the enzyme involved in formation of Pk, P1 and NOR antigens. Altogether, this approach affords a new insight into the mechanism of action of the human Gb3/CD77 synthase.
Assuntos
Galactosiltransferases , Glicoesfingolipídeos/biossíntese , Mutação de Sentido Incorreto , Acetilgalactosamina/genética , Acetilgalactosamina/metabolismo , Substituição de Aminoácidos , Antígenos Nucleares/genética , Antígenos Nucleares/metabolismo , Linhagem Celular Tumoral , Galactosiltransferases/genética , Galactosiltransferases/metabolismo , Glicoesfingolipídeos/genética , Humanos , Especificidade por SubstratoRESUMO
Orbital fractures are common, accounting for nearly 40% of all facial fractures. Open repair is required to restore preinjury orbital volume and relieve any extra-ocular muscle entrapment. Monitoring for postoperative intraorbital hemorrhage, and its consequent potential for visual impairment, has triggered most surgeons to observe their patients in the hospital overnight postoperatively. The real risk of postoperative hemorrhage in this patient group, however, is uncertain and the need to contain healthcare costs clear. The objective of this study was thus to determine the incidence of emergent postoperative complications in patients undergoing orbital fracture repair to determine the feasibility of performing this operation on an outpatient basis. Patients who sustained isolated orbital fractures and underwent open repair at this level-1 trauma center between January 2002 and January 2012 using International Classification of Disease-9 and Current Procedural Terminology 2012 coding were identified. Demographic data and postoperative complications were identified by reviewing the electronic medical record. Furthermore, critical analysis of available published evidence was performed. Ninety-three patients who satisfied the inclusion criteria were selected. There were no patients of an intraorbital hematoma or other immediate postoperative complications that required operative intervention. Average hospital length of stay was 0.85 days. Repair of orbital fractures on an outpatient basis appears to be safe. The theoretical risk of a complicating intraorbital hematoma seems to be between 0 and 3.2%. This can be minimized through: the use of open surgical access site and perforated floor replacement materials, careful early monitoring, education of patients, and admission of those at potentially elevated risk.
Assuntos
Procedimentos Cirúrgicos Ambulatórios/métodos , Fixação Interna de Fraturas/métodos , Fraturas Orbitárias/cirurgia , Pacientes Ambulatoriais , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Criança , Feminino , Humanos , Incidência , Masculino , Pessoa de Meia-Idade , Fraturas Orbitárias/diagnóstico , Complicações Pós-Operatórias/epidemiologia , Estudos Retrospectivos , Tomografia Computadorizada por Raios X , Resultado do Tratamento , Estados Unidos/epidemiologia , Adulto JovemRESUMO
INTRODUCTION: Repair of zygomatic fractures can be classified into the early closed reduction or the more recent open reduction and rigid internal fixation (ORIF) methods. Surgical training and literature advocate ORIF, but the actual frequency of the different techniques in clinical practice is unknown. The purpose of this study was to determine the current trends in the management of zygomatic fractures among US surgeons and elucidate their influences. METHODS: A 10-question survey was developed and distributed to over 16,000 practicing US facial trauma surgeons, including plastic surgeons (PS), oral and maxillofacial surgeons (OMFS), and otorhinolaryngologists (ENT). The survey queried training background, zygoma fracture treatment preferences, and rationale. Responses were tabulated and both univariate and bivariate statistical analyses completed. RESULTS: One thousand six hundred eleven (10%) total responses were received. Zygomatic fractures are treated most commonly by OMFS (61%), then PS (20%) and ENT (19%), with 71% of repairs being performed in private practice. Open reduction and rigid internal fixation is the most common treatment modality (81%), with most surgeons using 2 to 3 sites for exposure, reduction, and fixation with titanium miniplates (70%). Thirty-five percent of surgeons perform routine orbital floor exploration. Forty-three percent quoted training and 32% reported accuracy of repair as the primary reason for choosing ORIF. CONCLUSIONS: This is the largest reported survey on the repair of zygoma fractures. The response rate suggests dominance of OMFS in zygoma fracture care, an area pioneered by PS. Evolution of technique is also evident by predominance of ORIF with emphasis of multiple points of exposure, reduction, and fixation with rigid hardware.
Assuntos
Fixação Interna de Fraturas/métodos , Procedimentos Cirúrgicos Ortognáticos , Padrões de Prática Médica , Fraturas Zigomáticas/cirurgia , Humanos , Inquéritos e QuestionáriosRESUMO
Reconstruction of combined nose, cheek, and/or inferior eyelid defects is facilitated by stable anchorage at the nasal-cheek junction. The previously reported techniques of drill holes and Mitek anchors are not without disadvantages. The authors present a simple means of anchoring soft tissue flaps at the nasal-cheek junction: a titanium miniplate secured with a screw at each end. Our case report describes successful, lasting, and complication-free anchorage of cheek, forehead, and eyelid flaps to a single miniplate placed along the piriform aperture.
Assuntos
Materiais Biocompatíveis/química , Placas Ósseas , Bochecha/cirurgia , Nariz/cirurgia , Titânio/química , Idoso , Pálpebras/cirurgia , Feminino , Seguimentos , Testa/cirurgia , Humanos , Masculino , Pessoa de Meia-Idade , Cavidade Nasal/cirurgia , Neoplasias Nasais/cirurgia , Procedimentos de Cirurgia Plástica/instrumentação , Procedimentos de Cirurgia Plástica/métodos , Estudos Retrospectivos , Retalhos Cirúrgicos/transplante , Âncoras de SuturaRESUMO
BACKGROUND: Although excellent techniques for reconstruction of nasal cover and support have been described, reconstruction of large nasal lining defects remains a challenge. Currently available methods have several shortcomings including limited size, airway obstruction, need for multiple procedures, and creation of septal fistulae. METHODS: We present 2 cases of nasal lining reconstruction for the lower and mid nasal vaults using a contralateral dorsally based septal mucoperichondrial page flap transposed dorsal to nasal septum and superficial to the ipsilateral upper lateral cartilage. Appropriate, uncomplicated, reconstruction of nasal lining was confirmed in both cases. DISCUSSION: In the lower vault, the flap permits a single-stage reconstruction, without obstruction of the external nasal valve or compromise of caudal septal support. In the mid-vault, the flap allows for reconstruction without creation of a septal fistula or narrowing of the internal nasal valve. In both locations, the size of the flap may be increased by extending it onto nasal floor, and support may be added by combining the flap with septal cartilage. CONCLUSION: The contralateral dorsally based septal mucoperichondrial flap is a useful option for reconstruction of lower and mid nasal vault lining defects.
Assuntos
Cartilagens Nasais/transplante , Septo Nasal/cirurgia , Neoplasias Nasais/cirurgia , Rinoplastia/métodos , Retalhos Cirúrgicos , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-IdadeRESUMO
PURPOSE: Currently used open reduction and internal fixation techniques of zygoma fracture repair are not optimal. Surgical exposure of those sites needed to allow for accurate reduction and for rigid fixation has a high possibility of negative consequences. The objective of the present study was to present a single-incision, single-fixation site zygoma fracture repair technique using a single zygoma c-arm view to quantitatively determine its accuracy, complication rate, and practical aspects in a clinical series. MATERIALS AND METHODS: In a prospective study, consecutive patients with isolated, unilateral, displaced zygoma fractures not requiring orbital floor exploration treated using a c-arm-assisted repair technique at the author's institution from 2009 to 2011 were included. Objective outcomes assessed included accuracy of zygoma realignment (on postoperative computed tomogram), ocular globe projection symmetry (using a Naugle exophthalmometer), complication rate, and operative duration. Statistical analysis was performed using the Student t test. RESULTS: Twenty patients were included. Differences in zygoma projection, width, and height between the uninjured and repaired sides of the face were clinically noteworthy (>3 mm) in the first patient only. Average differences of these parameters for all 20 patients were clinically and statistically insignificant. Differences in ocular globe projection between the uninjured and repaired sides of the face for each patient were no greater than 2 mm. The average difference in globe projection for all 20 patients was also clinically and statistically insignificant. No major complications occurred, and the average operative duration was 76 minutes. CONCLUSIONS: The present study shows that the c-arm-assisted zygoma fracture repair technique is accurate, has a low complication rate, can be performed quickly, and has a relatively low level of difficulty.
Assuntos
Fixação Interna de Fraturas/métodos , Radiografia Intervencionista/métodos , Fraturas Zigomáticas/cirurgia , Adulto , Placas Ósseas , Cefalometria/métodos , Olho/patologia , Feminino , Seguimentos , Fixação Interna de Fraturas/instrumentação , Humanos , Imageamento Tridimensional/métodos , Luxações Articulares/diagnóstico por imagem , Luxações Articulares/cirurgia , Masculino , Maxila/patologia , Duração da Cirurgia , Complicações Pós-Operatórias , Estudos Prospectivos , Radiografia Intervencionista/instrumentação , Estudos Retrospectivos , Sela Túrcica/patologia , Deiscência da Ferida Operatória/etiologia , Tomografia Computadorizada por Raios X/métodos , Resultado do Tratamento , Ecrans Intensificadores para Raios X , Zigoma/patologia , Fraturas Zigomáticas/diagnóstico por imagemRESUMO
The erythrocyte binding ligand 140 (EBA-140) is a member of the Plasmodium falciparum DBL family of erythrocyte binding proteins, which are considered as prospective candidates for malaria vaccine development. The EBA-140 ligand is a paralogue of the well-characterized P. falciparum EBA-175 protein. They share homology of domain structure, including Region II, which consists of two homologous F1 and F2 domains and is responsible for ligand-erythrocyte receptor interaction during invasion. In this report we describe, for the first time, the glycophorin C specificity of the recombinant, baculovirus-expressed binding region (Region II) of P. falciparum EBA-140 ligand. It was found that the recombinant EBA-140 Region II binds to the endogenous and recombinant glycophorin C, but does not bind to Gerbich-type glycophorin C, neither normal nor recombinant, which lacks amino acid residues 36-63 of its polypeptide chain. Our results emphasize the crucial role of this glycophorin C region in EBA-140 ligand binding. Moreover, the EBA-140 Region II did not bind either to glycophorin D, the truncated form of glycophorin C lacking the N-glycan or to desialylated GPC. These results draw attention to the role of glycophorin C glycans in EBA-140 binding. The full identification of the EBA-140 binding site on glycophorin C molecule, consisting most likely of its glycans and peptide backbone, may help to design therapeutics or vaccines that target the erythrocyte binding merozoite ligands.
Assuntos
Baculoviridae/imunologia , Proteínas de Transporte/metabolismo , Eritrócitos/metabolismo , Glicoforinas/metabolismo , Proteínas de Protozoários/metabolismo , Vacinas Antimaláricas/imunologia , Malária Falciparum/imunologia , Malária Falciparum/prevenção & controle , Proteínas de Membrana , Plasmodium falciparum , Ligação ProteicaRESUMO
PURPOSE: The precise computed tomography-based calculation of the size of an orbital floor (OF) fracture defect is tedious and time-consuming. The aims of this study were to evaluate the accuracy of simple, rapid methods of calculating OF fracture defect size and to determine their suitability for clinical use. MATERIALS AND METHODS: A retrospective review of the electronic medical records of patients with OF fractures presenting to Baylor Scott and White Hospital between October 2009 and April 2013 was performed. True OF defect sizes (the outcome variable) were calculated using a previously validated formula, on the basis of measurements obtained from coronally reformatted thin (<3-mm) axial computed tomographic images. Estimated OF defect sizes (the predictor variable) were calculated using geometric area formulas, assuming that the defect approximated the shape of an ellipse, circle, square, or rectangle on the basis of measurements obtained from coronal and sagittal computed tomographic images. Accuracy, sensitivity, specificity, and negative and positive predictive values in declaring a defect critical were determined for each method. RESULTS: Ninety-nine patients with OF fractures were identified (69 men, 30 women; mean age = 46.9 years); 55 patients had a true OF defects of critical (≥2 cm(2)) or greater size. Geometric formulas showed ranges of accuracy (0.76 to 0.93), sensitivity (0.62 to 1.0), and specificity (0.63 to 0.91). The accuracy of defect size approximation using the area of an ellipse was highest. CONCLUSIONS: The geometric formulas estimated OF defect area with good but, in the authors' opinion, clinically unacceptable accuracy. Although highly sensitive, the formulas lacked specificity and tended to overestimate true defect sizes in most cases. Using rapid, simple geometric methods to assess the sizes of OF defects may lead to inappropriate surgical decisions. Thus, the most accurate estimation of OF defect size still requires the calculation of average defect length from coronal computed tomographic images, knowledge of slice thickness, and knowledge of the number of slices involved.
Assuntos
Cefalometria/estatística & dados numéricos , Fraturas Orbitárias/diagnóstico por imagem , Tomografia Computadorizada por Raios X/estatística & dados numéricos , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Algoritmos , Feminino , Humanos , Processamento de Imagem Assistida por Computador/estatística & dados numéricos , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Sistemas de Informação em Radiologia/estatística & dados numéricos , Estudos Retrospectivos , Sensibilidade e Especificidade , Adulto JovemRESUMO
Rare polyagglutinable NOR erythrocytes contain three unique globoside (Gb4Cer) derivatives, NOR1, NOR(int), and NOR2, in which Gal(α1-4), GalNAc(ß1-3)Gal(α1-4), and Gal(α1-4)GalNAc(ß1-3)Gal(α1-4), respectively, are linked to the terminal GalNAc residue of Gb4Cer. NOR1 and NOR2, which both terminate with a Gal(α1-4)GalNAc- sequence, react with anti-NOR antibodies commonly present in human sera. While searching for an enzyme responsible for the biosynthesis of Gal(α1-4)GalNAc, we identified a mutation in the A4GALT gene encoding Gb3/CD77 synthase (α1,4-galactosyltransferase). Fourteen NOR-positive donors were heterozygous for the C>G mutation at position 631 of the open reading frame of the A4GALT gene, whereas 495 NOR-negative donors were homozygous for C at this position. The enzyme encoded by the mutated gene contains glutamic acid instead of glutamine at position 211 (substitution Q211E). To determine whether this mutation could change the enzyme specificity, we transfected a teratocarcinoma cell line (2102Ep) with vectors encoding the consensus Gb3/CD77 synthase and Gb3/CD77 synthase with Glu at position 211. The cellular glycolipids produced by these cells were analyzed by flow cytometry, high-performance thin-layer chromatography, enzymatic degradation, and MALDI-TOF mass spectrometry. Cells transfected with either vector expressed the P1 blood group antigen, which was absent from untransfected cells. Cells transfected with the vector encoding the Gb3/CD77 synthase with Glu at position 211 expressed both P1 and NOR antigens. Collectively, these results suggest that the C631G mutation alters the acceptor specificity of Gb3/CD77 synthase, rendering it able to catalyze synthesis of the Gal(α1-4)Gal and Gal(α1-4)GalNAc moieties.
Assuntos
Substituição de Aminoácidos , Galactosiltransferases/genética , Hemaglutinação/genética , Mutação Puntual , Sequência de Carboidratos , Linhagem Celular Tumoral , Células-Tronco de Carcinoma Embrionário/metabolismo , Células-Tronco de Carcinoma Embrionário/patologia , Citometria de Fluxo , Galactosiltransferases/metabolismo , Predisposição Genética para Doença , Genótipo , Globosídeos/biossíntese , Globosídeos/química , Ácido Glutâmico/genética , Ácido Glutâmico/metabolismo , Glutamina/genética , Glutamina/metabolismo , Humanos , Dados de Sequência Molecular , Fenótipo , Polimorfismo de Nucleotídeo Único , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz , SíndromeRESUMO
Serum of animals belonging to the Camelidae family (camels and llamas) contains fully active antibodies that are naturally devoid of light chains. Variable domains derived from heavy chain antibodies (hcAb) called VHHs or nanobodies™ can bind antigens as effectively as full-length antibodies and are easy to clone and express. Because of their potential, VHHs are being intensively studied as potential therapeutic, diagnostic and imaging tools. The paper reviews the molecular background of heavy chain antibodies and describes methods of obtaining recombinant fragments of heavy chain antibodies as well as their therapeutic, diagnostic and other applications.
Assuntos
Fragmentos de Imunoglobulinas/uso terapêutico , Cadeias Pesadas de Imunoglobulinas/uso terapêutico , Animais , Antineoplásicos/metabolismo , Antineoplásicos/uso terapêutico , Doenças Autoimunes/tratamento farmacológico , Camelídeos Americanos , Cromatografia de Afinidade/métodos , Doenças Transmissíveis/tratamento farmacológico , Peixes , Doenças Hematológicas/tratamento farmacológico , Humanos , Fragmentos de Imunoglobulinas/química , Fragmentos de Imunoglobulinas/isolamento & purificação , Cadeias Pesadas de Imunoglobulinas/química , Cadeias Pesadas de Imunoglobulinas/isolamento & purificação , Anticorpos de Domínio Único/química , Anticorpos de Domínio Único/isolamento & purificação , Anticorpos de Domínio Único/uso terapêutico , Especificidade da EspécieRESUMO
BACKGROUND: Complex craniosynostoses (i.e., multisutural, nonsyndromic) are rare and present unique treatment challenges. The authors sought to assess long-term outcomes, including postsurgical growth and development, to develop evidence-based treatment algorithms. METHODS: A retrospective review of all patients identified as having multiple sutural synostosis excluding bicoronal and FGFR- and TWIST-associated synostoses was conducted. Data were summarized using descriptive statistics. RESULTS: Over an 18-year period, 858 patients underwent craniosynostosis correction, and 31 patients (3.6 percent) satisfied inclusion criteria. Average number of affected sutures was 2.9 (lambdoid, 36 percent; sagittal, 31 percent; coronal, 18 percent; metopic, 15 percent), and 1.7 procedures were performed per patient (mean follow-up, 3.5 years). Average hospital stay was 2.3 days, 21 percent required blood transfusions, and there were no major complications. For synostosis patterns isolated to one side of the anterior sagittal suture (anterior or posterior skull halves), 93 percent were corrected with a single procedure. When the synostosis pattern crossed both skull halves, 80 percent underwent two procedures (p<0.001). Forty percent developed acquired Chiari deformations; of these, 60 percent required decompression. The incidence of Chiari deformations increased from 7 percent to 70 percent with lambdoid sutural involvement (p<0.002). Anthropometric data revealed postoperative growth impairment. Gross developmental delays were noted in 20 percent (mild, 16 percent; moderate to severe, 4 percent). CONCLUSIONS: Complex craniosynostoses are associated with a higher incidence of acquired Chiari deformations (especially with lambdoid involvement), require multiple operative procedures, and may have more developmental delays than the isolated single sutural synostoses. The authors recommend surgical paradigms based on sutural involvement, compensatory surgical overcorrection, and routine magnetic resonance imaging monitoring for Chiari deformations. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, IV.