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1.
Mult Scler Relat Disord ; 68: 104121, 2022 Dec.
Article in English | MEDLINE | ID: mdl-36088727

ABSTRACT

BACKGROUND: Following the outbreak of COVID-19, global healthcare systems have had to rapidly adapt. People with multiple sclerosis (pwMS) were required to make decisions about their individual risk and consequent work and social behaviors. This study aimed to evaluate risk perception and patterns of shielding behavior amongst pwMS at the onset of the COVID-19 pandemic and the subsequent impact on patients' employment and access to disease modifying therapies (DMTs). METHODS: Postal surveys were sent to 1690 people within a UK population-based MS cohort during the first wave of the COVID-19 pandemic. Patients were surveyed on: (i) perceived vulnerability to COVID-19; (ii) isolation behavior; (iii) interruption to DMT; (iv) employment status; (v) level of satisfaction with their current working arrangement. RESULTS: Responses were received from 1000 pwMS. Two thirds of patients reported isolating at home during the first wave of the pandemic. This behavior was associated with increased age (p<0.0001), higher disability (p<0.0001) and use of high-efficacy DMTs (p = 0.02). The majority of patients reported feeling vulnerable (82%) with perceived vulnerability associated with higher EDSS (p<0.0001) and receiving a high-efficacy DMT (p = 0.04). Clinician-defined risk was associated with shielding behavior, with those at high-risk more likely to self-isolate/shield (p<0.0001). Patients on high-efficacy DMTs were more likely to have an interruption to their treatment (50%) during the first wave of the pandemic. Most pwMS experienced a change to their working environment, and most were satisfied with the adjustments. CONCLUSION: This study highlights the risk perception, social behavioral practices and changes to treatment experienced by pwMS during the first wave of the COVID-19 pandemic in a large, well-described UK cohort. The results may help inform management of pwMS during future pandemic waves.


Subject(s)
COVID-19 , Multiple Sclerosis , Humans , COVID-19/complications , Multiple Sclerosis/drug therapy , Multiple Sclerosis/epidemiology , Multiple Sclerosis/complications , Pandemics , Delivery of Health Care , Perception
2.
Med. infant ; 28(1): 27-32, Marzo 2021. Tab
Article in Spanish | BINACIS, UNISALUD, LILACS | ID: biblio-1282913

ABSTRACT

Introducción: El mielomeningocele (MMC) es una de las malformaciones congénitas más severas compatible con la vida. El 90% de los pacientes presenta vejiga neurogénica que debe ser evaluada y tratada precozmente. Objetivos: Describir la evaluación y tratamiento nefrourológico recibido por pacientes con MMC hasta el momento de la primera consulta en el Hospital Garrahan (periodo pre-ingreso). Describir la evaluación realizada y el tratamiento urológico implementado a partir del ingreso al hospital Garrahan (periodo post-ingreso). Evaluar la prevalencia de Enfermedad Renal Crónica (ERC). Población y Métodos: Se realizó un estudio con diseño clínico analítico, retrospectivo, longitudinal sobre pacientes con MMC de 1 mes a 18 años derivados al Hospital Garrahan para atención ambulatoria en los años 2011 y 2012. Resultados: Se incluyeron115 pacientes. Al momento de la derivación al hospital ("pre-ingreso") 7% de los pacientes habían logrado completar evaluación nefrourológica, (ecografía vesicorenal, urodinamia, Cistouretrografía, Centellograma renal y Creatininemia). Tratamiento: 33% vaciaban vejiga por CIL o vesicostomía y 21% recibían Oxibutinina. A partir del ingreso al seguimiento en el Garrahan 83% lograron completar la evaluación, y en función del resultado de la misma se indicó CIL en 87% y Oxibutinina en el 66% de los pacientes. La prevalencia de ERC al ingreso fue de 43%; la mayoría en estadio I. Conclusiones: La mayoría de los pacientes con MMC fueron derivados al hospital de tercer nivel con evaluaciones urológicas incompletas y sin el tratamiento adecuado de la vejiga neurogénica. El inicio del seguimiento interdisciplinario en un hospital de alta complejidad facilitó la realización de las evaluaciones necesarias y la implementación del tratamiento adecuado (AU)


Introduction: Myelomeningocele (MMC) is one of the most severe congenital malformations compatible with life. Of all the patients, 90% presents with a neurogenic bladder requiring early evaluation and treatment. Objectives: To describe the uronephrological evaluation and treatment received by patients with MMC up to the first consultation at Garrahan Hospital (pre-follow-up period). To describe the urological evaluation and treatment implemented from referral to Garrahan Hospital (follow-up period). To evaluate the prevalence of chronic kidney disease (CKD). Population and Methods: A retrospective, longitudinal study with a clinical, analytical design was conducted in patients with MMC between 1 months and 18 years of age referred to Garrahan Hospital for outpatient care in 2011 and 2012. Results: 115 patients were included. At the time of referral to the hospital ("pre-follow-up") 7% of the patients had undergone complete uronephrological evaluation (kidney-bladder ultrasonography, urodynamic studies, cystourethrography, renal scintigraphy, and creatininemia levels). Treatment: 33% emptied their bladder by CIC or vesicostomy and 21% received oxybutynin. From follow-up initiation at Garrahan Hospital, 83% underwent complete evaluation, and based on the results CIC was indicated in 87% and oxybutynin in 66% of the patients. On admission, prevalence of CKD was 43%; with stage I in the majority of the patients. Conclusions: The majority of the patients with MMC were referred to a third-level hospital with incomplete urological studies and without adequate treatment of the neurogenic bladder. Initiation of interdisciplinary follow-up at a tertiary hospital allowed for the necessary studies and implementation of adequate treatment (AU)


Subject(s)
Humans , Infant , Child, Preschool , Child , Adolescent , Patient Care Team , Urinary Bladder, Neurogenic/diagnosis , Urinary Bladder, Neurogenic/etiology , Urinary Bladder, Neurogenic/therapy , Meningomyelocele/complications , Meningomyelocele/diagnosis , Meningomyelocele/epidemiology , Renal Insufficiency, Chronic/therapy , Kidney Function Tests
3.
Anim Genet ; 51(4): 607-610, 2020 Aug.
Article in English | MEDLINE | ID: mdl-32412131

ABSTRACT

An 11G nucleotide repeat in the 3' UTR of FAM174A was recently postulated as a risk allele with a dominant mode of inheritance for equine metabolic syndrome (EMS) and laminitis status in Arabian horses. The objective of this project was to evaluate this hypothesis in a large and diverse across-breed population. A total of 301 ponies, 292 Morgans, 64 Arabians, 49 Tennessee Walking Horses and 59 Quarter Horses were genotyped for six observed G repeat alleles in the FAM174A 3' UTR. Phenotype data included laminitis status, baseline insulin, glucose, non-esterified fatty acids, triglycerides, adiponectin, leptin, ACTH, insulin and glucose post oral sugar test, and two proxies for insulin resistance. The 11G allele frequencies were 18.8, 6.9, 1.8, 0.2 and 0.0% in the Arabians, Tennessee Walkers, ponies, Morgans and Quarter Horses respectively. Association analyses between FAM174A genotype and EMS phenotypes, and between allele count and EMS phenotypes, identified no statistically significant associations. When a dominant effect for the 11G allele was evaluated, a statistically significant association with adiponectin levels was identified in the ponies, and pairwise comparisons revealed that the estimated marginal means were higher in ponies with the 11G allele vs. alternative alleles (i.e. the allele had a protective effect). In conclusion, our data do not support the FAM174A 11G allele as a risk allele for EMS in our studied breeds.


Subject(s)
Foot Diseases/veterinary , Horse Diseases/genetics , Metabolic Syndrome/veterinary , Alleles , Animals , Female , Foot Diseases/genetics , Horses , Male , Metabolic Syndrome/genetics , Risk Factors
4.
Sci Rep ; 9(1): 15128, 2019 10 22.
Article in English | MEDLINE | ID: mdl-31641151

ABSTRACT

Enterotoxin-based adjuvants including cholera toxin and heat-labile toxin (LT) are powerful manipulators of mucosal immunity; however, past clinical trials identified unacceptable neurological toxicity when LT or mutant AB5 adjuvant proteins were added to intranasal vaccines. Here, we examined the isolated enzymatic A1 domain of LT (LTA1) for intranasal safety and efficacy in combination with influenza (flu) vaccination. LTA1-treated mice exhibited no neurotoxicity, as measured by olfactory system testing and H&E staining of nasal tissue in contrast with cholera toxin. In vaccination studies, intranasal LTA1 enhanced immune responses to inactivated virus antigen and subsequent protection against H1N1 flu challenge in mice (8-week or 24-months). In addition, lung H1N1 viral titers post-challenge correlated to serum antibody responses; however, enhanced protection was also observed in µMT mice lacking B-cells while activation and recruitment of CD4 T-cells into the lung was apparent. Thus, we report that LTA1 protein is a novel, safe and effective enterotoxin adjuvant that improves protection of an intranasal flu vaccination by a mechanism that does not appear to require B-cells.


Subject(s)
Adjuvants, Immunologic/administration & dosage , Aging/immunology , B-Lymphocytes/immunology , Enterotoxins/administration & dosage , Lymphocyte Depletion , Orthomyxoviridae Infections/immunology , Orthomyxoviridae Infections/prevention & control , Adjuvants, Immunologic/pharmacology , Administration, Intranasal , Animals , Antibodies/blood , Antibody Formation/drug effects , B-Lymphocytes/drug effects , CD4-Positive T-Lymphocytes/drug effects , CD4-Positive T-Lymphocytes/immunology , Dose-Response Relationship, Immunologic , Enterotoxins/immunology , Enterotoxins/toxicity , Female , Immunity, Mucosal/drug effects , Immunization , Inflammation/pathology , Influenza A Virus, H1N1 Subtype/immunology , Lung/virology , Lymphocyte Activation/drug effects , Mast Cells/drug effects , Mast Cells/pathology , Mice, Inbred C57BL , Orthomyxoviridae Infections/blood , Orthomyxoviridae Infections/virology
5.
Equine Vet J ; 51(4): 475-480, 2019 Jul.
Article in English | MEDLINE | ID: mdl-30472742

ABSTRACT

BACKGROUND: Equine metabolic syndrome (EMS) is a complex clinical disorder with both environmental and genetic factors contributing to EMS phenotypes. Estimates of heritability determine the proportion of variation in a trait that is attributable to genetics. OBJECTIVES: To provide heritability estimates for nine metabolic traits associated with EMS in two high-risk breeds. STUDY DESIGN: Retrospective cohort study. METHODS: High-density single-nucleotide polymorphism (SNP) genotype data was used to estimate the heritability (h2 SNP ) of nine metabolic traits relevant to EMS in a cohort of 264 Welsh ponies and 286 Morgan horses. Traits included measurements of insulin, glucose, non-esterified fatty acids (NEFA), triglycerides, leptin, adiponectin, ACTH, and glucose (GLU-OST) and insulin (INS-OST) following an oral sugar challenge. RESULTS: In Welsh ponies, seven of the nine traits had statistically significant h2 SNP estimates that were considered moderately to highly heritable (h2 SNP >0.20) including: triglycerides (0.313; s.e. = 0.146), glucose (0.408; s.e. = 0.135), NEFA (0.434; s.e. = 0.136), INS-OST (0.440; s.e. = 0.148), adiponectin (0.488; s.e. = 0.143), leptin (0.554; s.e. = 0.132) and insulin (0.808; s.e. = 0.108). In Morgans, six of the nine traits had statistically significant h2 SNP estimates that were also determined to be moderately to highly heritable including: INS-OST (0.359; s.e. = 0.185), leptin (0.486; s.e. = 0.177), GLU-OST (0.566 s.e. = 0.175), insulin (0.592; s.e. = 0.195), NEFA (0.684; s.e. = 0.164), and adiponectin (0.913; s.e. = 0.181). MAIN LIMITATIONS: Insufficient population size may have limited power to obtain statistically significant h2 SNP estimates for ACTH (both breeds), glucose and triglycerides in Morgans and GLU-OST in Welsh ponies. CONCLUSIONS: This study provides the first concrete evidence of a genetic contribution to key phenotypes associated with EMS. Eight of these nine traits had moderate to high h2 SNP estimates in this cohort. These data demonstrate that continued research for identification of the genetic risk factors for EMS phenotypes within and across breeds is warranted.


Subject(s)
Genetic Predisposition to Disease , Horse Diseases/metabolism , Metabolic Syndrome/veterinary , Animals , Blood Glucose , Fatty Acids, Nonesterified , Female , Genotype , Horse Diseases/genetics , Horses , Insulin/blood , Male , Metabolic Syndrome/genetics , Polymorphism, Single Nucleotide
6.
Chemosphere ; 218: 652-661, 2019 Mar.
Article in English | MEDLINE | ID: mdl-30502704

ABSTRACT

Equine Metabolic Syndrome (EMS) is characterized by abnormalities in insulin regulation, increased adiposity and laminitis, and has several similarities to human metabolic syndrome. A large amount of environmental variability in the EMS phenotype is not explained by commonly measured factors (diet, exercise, and season), suggesting that other environmental factors play a role in EMS development. Endocrine disrupting chemicals (EDCs) are associated with metabolic syndrome and other endocrine abnormalities in humans. This led us to hypothesize that EDCs are detectable in horse plasma and play a role in the pathophysiology of EMS. EDCs acting through the aryl hydrocarbon and estrogen receptors, were measured in plasma of 301 horses from 32 farms. The median (range) TEQ (2,3,7,8-TCDD equivalent) and EEQ (17ß-estradiol equivalent) were 19.29 pg/g (0.59-536.36) and 10.50 pg/ml (4.35-15000.00), respectively. TEQ was negatively associated with plasma fat extracted and batch analyzed. EEQ was positively associated with pregnancy and batch analyzed, and negatively associated with being male and superfund score ≤100 miles of the farm. Of particular interest, serum glucose and insulin, glucose and insulin post oral sugar challenge, and leptin concentrations were associated with EEQ, and serum triglyceride concentration was associated with TEQ. Overall, we demonstrated that EDCs are present in the plasma of horses and may explain some of the environmental variability in measured EMS phenotypes. This is the first example of EDCs being associated with clinical disease phenotype components in domestic animals.


Subject(s)
Endocrine Disruptors/blood , Horse Diseases/metabolism , Metabolic Syndrome/metabolism , Animals , Blood Glucose , Endocrine Disruptors/chemistry , Female , Horse Diseases/etiology , Horses , Insulin/blood , Leptin/blood , Male , Metabolic Syndrome/etiology , Phenotype , Pregnancy
7.
Anim Genet ; 50(1): 78-81, 2019 Feb.
Article in English | MEDLINE | ID: mdl-30353927

ABSTRACT

Osteochondrosis is a common developmental orthopedic disease characterized by a failure of endochondral ossification. Standardbred horses are recognized as being predisposed to tarsal osteochondrosis. Prior heritability estimates for tarsal osteochondrosis in European Standardbreds and related trotting breeds have been based on pedigree data and range from 17-29%. Here, we report on genetic architecture and heritability based on high-density genotyping data in a cohort of North American Standardbreds (n = 479) stringently phenotyped for tarsal osteochondrosis. Whole-genome array genotyping data were imputed to ~2 million single nucleotide polymorphisms (SNPs). SNP-based heritability of osteochondrosis in this population was explained by 2326 SNPs. The majority of these SNPs (86.6%) had small effects, whereas fewer SNPs had moderate or large effects (10% and 2.9% respectively), which is consistent with a polygenic/complex disease. Heritability was estimated at 0.24 ± 0.16 using two methods of restricted maximum likelihood analysis, as implemented in gcta (with and without a weighted relatedness matrix) and ldak software. Estimates were validated using bootstrapping. Heritability estimates were within the range previously reported and suggest that osteochondrosis is moderately heritable but that a significant portion of disease risk is due to environmental factors and/or genotype × environment interactions. Future identification of the genes/variants that have the most impact on disease risk may allow early recognition of high-risk individuals.


Subject(s)
Horse Diseases/genetics , Horses/genetics , Osteochondrosis/veterinary , Polymorphism, Single Nucleotide , Animals , Gene-Environment Interaction , Genetic Predisposition to Disease , Genotype , Interatrial Block , Likelihood Functions , Models, Genetic , North America , Osteochondrosis/genetics , Phenotype
9.
Acta Crystallogr D Struct Biol ; 73(Pt 1): 9-21, 2017 Jan 01.
Article in English | MEDLINE | ID: mdl-28045381

ABSTRACT

A number of X-ray analyses of an enzyme involved in a key early stage of tetrapyrrole biosynthesis are reported. Two structures of human 5-aminolaevulinate dehydratase (ALAD), native and recombinant, have been determined at 2.8 Šresolution, showing that the enzyme adopts an octameric quaternary structure in accord with previously published analyses of the enzyme from a range of other species. However, this is in contrast to the finding that a disease-related F12L mutant of the human enzyme uniquely forms hexamers [Breinig et al. (2003), Nature Struct. Biol. 10, 757-763]. Monomers of all ALADs adopt the TIM-barrel fold; the subunit conformation that assembles into the octamer includes the N-terminal tail of one monomer curled around the (α/ß)8 barrel of a neighbouring monomer. Both crystal forms of the human enzyme possess two monomers per asymmetric unit, termed A and B. In the native enzyme there are a number of distinct structural differences between the A and B monomers, with the latter exhibiting greater disorder in a number of loop regions and in the active site. In contrast, the second monomer of the recombinant enzyme appears to be better defined and the active site of both monomers clearly possesses a zinc ion which is bound by three conserved cysteine residues. In native human ALAD, the A monomer also has a ligand resembling the substrate ALA which is covalently bound by a Schiff base to one of the active-site lysines (Lys252) and is held in place by an ordered active-site loop. In contrast, these features of the active-site structure are disordered or absent in the B subunit of the native human enzyme. The octameric structure of the zinc-dependent ALAD from the hyperthermophile Pyrobaculum calidifontis is also reported at a somewhat lower resolution of 3.5 Å. Finally, the details are presented of a high-resolution structure of the Escherichia coli ALAD enzyme co-crystallized with a noncovalently bound moiety of the product, porphobilinogen (PBG). This structure reveals that the pyrrole side-chain amino group is datively bound to the active-site zinc ion and that the PBG carboxylates interact with the enzyme via hydrogen bonds and salt bridges with invariant residues. A number of hydrogen-bond interactions that were previously observed in the structure of yeast ALAD with a cyclic intermediate resembling the product PBG appear to be weaker in the new structure, suggesting that these interactions are only optimal in the transition state.

12.
IET Nanobiotechnol ; 2(2): 47, 2008 Jun.
Article in English | MEDLINE | ID: mdl-18500912

ABSTRACT

A nanoscale sensor employing fluorescent resonance energy transfer interactions between fluorescent quantum dots (QDs) and organic quencher molecules can be used for the multiplexed detection of biological antigens in solution. Detection occurs when the antigens to be detected displace quencher-labelled inactivated (or dead) antigens of the same type attached to QD-antibody complexes through equilibrium reactions. This unquenches the QDs, allowing detection to take place through the observation of photoluminescence in solution or through the fluorescence imaging of unquenched QD complexes trapped on filter surfaces. Multiplexing can be accomplished by using several different sizes of QDs, with each size QD labelled with an antibody for a different antigen, providing the ability to detect several types of antigens or biological contaminants simultaneously in near real-time with high specificity and sensitivity.


Subject(s)
Biosensing Techniques/methods , Fluorescence Resonance Energy Transfer , Nanotechnology/methods , Quantum Dots , Affinity Labels/chemistry , Animals , Antibodies/chemistry , Antigen-Antibody Reactions , Antigens, Bacterial/analysis , Competitive Bidding , Energy Transfer , Escherichia coli , Kinetics , Particle Size , Sensitivity and Specificity
13.
Intensive Care Med ; 34(1): 174-8, 2008 Jan.
Article in English | MEDLINE | ID: mdl-17962921

ABSTRACT

OBJECTIVE: There remains significant variation in the level and rate of adoption of new pediatric respiratory technologies, in spite of two decades of focus on "evidence-based medicine". Nearly 50 years ago Rogers introduced a rubric for understanding issues that effect the adoption of technologies that included four factors plus evidence of advantage. We sought to determine whether Rogers' factors were useful in understanding contrasts between clinical utilization of technology and evidence of advantage. DESIGN, SETTING, PARTICIPANTS: We conducted a written survey at two international neonatal/pediatric respiratory conferences. We asked about use of four specific indications for high-frequency ventilation (HFV) and nasal continuous positive airway pressure (nCPAP). RESULTS: These four specific respiratory therapies were aggressively used by most, despite significant differences in the evidence supporting their utility: elective use of HFV (57.4%); HFV to treat ARDS (62.7%); nCPAP for weaning following extubation (83.9%); and nCPAP to avoid intubation (82.1%). CONCLUSIONS: Evidence of outcomes advantage should be the key factor in assessing potentially beneficial technologies. However, we suggest that understanding the influence of observe-ability, complexity and subjectivity of relative advantage explains much of the contrast between adoption level and outcome evidence. These factors described by Rogers, that encourage adoption of mediocre technologies or that retard adoption of potentially beneficial technologies, should be understood and acknowledged. This perspective can be applied not only to national adoption patterns, but also to adoption of best practices within an individual unit.


Subject(s)
Diffusion of Innovation , Respiratory Distress Syndrome/therapy , Continuous Positive Airway Pressure/statistics & numerical data , Health Care Surveys , High-Frequency Ventilation/statistics & numerical data , Humans , Infant, Newborn , Practice Patterns, Physicians'
16.
J Dent Res ; 84(10): 942-6, 2005 Oct.
Article in English | MEDLINE | ID: mdl-16183795

ABSTRACT

When randomization is not possible, researchers must control for non-random assignment to experimental groups. One technique for statistical adjustment for non-random assignment is through the use of a two-stage analytical technique. The purpose of this study was to demonstrate the use of this technique to control for selection bias in examining the effects of the The Supplemental Program for Women, Infants, and Children's (WIC) on dental visits. From 5 data sources, an analysis file was constructed for 49,512 children ages 1-5 years. The two-stage technique was used to control for selection bias in WIC participation, the potentially endogenous variable. Specification tests showed that WIC participation was not random and that selection bias was present. The effects of the WIC on dental use differed by 36% after adjustment for selection bias by means of the two-stage technique. This technique can be used to control for potential selection bias in dental research when randomization is not possible.


Subject(s)
Aid to Families with Dependent Children , Data Interpretation, Statistical , Dental Care for Children/statistics & numerical data , Health Services Accessibility/statistics & numerical data , Health Services Research/methods , Logistic Models , Adult , Child, Preschool , Cohort Studies , Delivery of Health Care , Dental Health Services/statistics & numerical data , Dental Health Surveys , Dental Research/methods , Female , Humans , Infant , Longitudinal Studies , Male , Medicaid/statistics & numerical data , Models, Economic , Randomized Controlled Trials as Topic/methods , Regression Analysis , Selection Bias , Socioeconomic Factors , United States
18.
Tissue Antigens ; 60(5): 354-64, 2002 Nov.
Article in English | MEDLINE | ID: mdl-12492811

ABSTRACT

The identification of unique sperm surface epitopes that are not expressed or exposed in the female reproductive tract is a key element in the development of antibody-based contraceptives. Western blotting and immunohistochemistry were performed to define the tissue distribution of the S19 epitope, which has been proposed as a target for immunocontraception. S19 is an IgG1 murine monoclonal antibody (mAb) directed to an N-linked carbohydrate epitope on a 15-25 kDa glycoprotein, sperm agglutination antigen-1 (SAGA-1), containing a peptide core identical to that of the lymphocytic surface protein CD52. In this study, the S19 epitope was shown to be absent from human lymphocytes, demonstrating a distinction between this epitope and the CAMPATH epitope that is recognized by an antibody against the terminal tripeptide and GPI-anchor of CD52. Further tissue specificity analysis identified the S19 epitope in the epithelium of the human epididymis and vas deferens, as well as on both epididymal and ejaculated spermatozoa. In contrast, the S19 epitope was absent in the five human female reproductive tract and 18 other somatic tissues tested. These results support the use of the S19 epitope as a contraceptive immunogen and the suitability of the S19 mAb as an intravaginal contraceptive. To test the agglutinating activity of the S19 mAb in a formulation designed for vaginal use, S19 mAb were bound to the surface of Novasomes, a multilamellar liposome delivery vehicle. S19-Novasome formulations agglutinated human spermatozoa and were as effective as unbound S19 mAb, demonstrating the feasibility of spermistatic contraceptives targeted to the male reproductive tract specific carbohydrate epitope.


Subject(s)
Antigens, CD/immunology , Antigens, Neoplasm/immunology , Carbohydrates/immunology , Epitopes , Genitalia, Male/immunology , Glycoproteins/immunology , Antibodies, Monoclonal/immunology , Blotting, Western , CD52 Antigen , Contraception, Immunologic , Epitope Mapping , Epitopes/immunology , Fluorescent Antibody Technique , Humans , Immunohistochemistry , Male , Organ Specificity/immunology
19.
Biochem Soc Trans ; 30(4): 584-90, 2002 Aug.
Article in English | MEDLINE | ID: mdl-12196142

ABSTRACT

5-Aminolaevulinic acid dehydratase catalyses the formation of porphobilinogen from two molecules of 5-aminolaevulinic acid. The studies described highlight the importance of a bivalent metal ion and two active-site lysine residues for the functioning of 5-aminolaevulinic acid dehydratase. Dehydratases fall into two main categories: zinc-dependent enzymes and magnesium-dependent enzymes. Mutations that introduced zinc-binding ligands into a magnesium-dependent enzyme conferred an absolute requirement for zinc. Mutagenesis of lysine residues 247 and 195 in the Escherichia coli enzyme lead to dramatic effects on enzyme activity, with lysine 247 being absolutely essential. Mutation of either lysine 247 or 195 to cysteine, and treatment of the mutant enzyme with 2-bromethylamine, resulted in the recovery of substantial enzyme activity. The effects of the site-directed alkylating inhibitor, 5-chlorolaevulinic acid, and 4,7-dioxosebacic acid, a putative intermediate analogue, were investigated by X-ray crystallography. These inhibitors reacted with both active-site lysine residues. The role of these two lysine residues in the enzyme mechanism is discussed.


Subject(s)
Porphobilinogen Synthase/chemistry , Porphobilinogen Synthase/metabolism , Amino Acid Sequence , Amino Acid Substitution , Binding Sites , Crystallography, X-Ray , Escherichia coli/enzymology , Lysine , Models, Molecular , Molecular Sequence Data , Mutagenesis, Site-Directed , Porphobilinogen Synthase/genetics , Recombinant Proteins/chemistry , Recombinant Proteins/metabolism , Saccharomyces cerevisiae/enzymology
20.
Med. infant ; 9(2): 109-117, jun. 2002. graf, tab
Article in Spanish | LILACS | ID: lil-517347

ABSTRACT

El trasplante hepático (TH) constituye la única alternativa terapéutica para numerosas enfermedades hepáticas avanzadas. Los adelantos en la técnica quirúrgica y en la inmunosupresión desarrollados en los últimos años permitieron mejorar la sobrevida. En la evolución a largo plazo de los pacientes trasplantados pueden presentarse complicaciones de diversa severidad. Objetivo: analizar la evolución a largo plazo de los pacientes trasplantados con un seguimiento mayor de 1 año post-TH. Material y Métodos: Durante el período 11/92-11/01 se realizaron 264 TH en 238 pacientes. De estos pacientes 143 (157 TH) fueron seguidos más allá de un año post-TH. La mediana de edad (m.a más menos DS) fue de 5,41 años más menos 5,26 (r:0.58 - 21.7 años); 76 pertenecían al sexo femenino. Catorce (9.79 por ciento) recibieron un re-TH. Fueron excluidos los pacientes que no habían cumplido todavía un años post- TH o los que fallecieron antes de ese lapso de seguimiento. Las indicaciones de TH fueron: falla hepática fulminante (FHF) (n:50); atresia de vías biliares (AVB) (n:38); cirrosis (n: 37); colestasis crónica (n: 13) y otras (n: 5). Las indicaciones de Re-TH fueron: cirrosis biliar (n: 7); trombosis de la arteria hepática (n: 4) y rechazo crónico (n: 3). En 73/157 TH se utilizaron injertos reducidos: 14 donantes vivos relacionados (DVR) y 11 biparticiones hepáticas. Se sometieron a análisis estadístico variables potenciales de morbimortalidad. Resultados: La sobrevida global fue: pacientes 93 por ciento: injerto: 86 por ciento. El re-TH y el injerto reducido fueron las variables de mayor significación para aumento del riesgo de muerte en nuestra población. El déficit de talla y masa ósea se recuperó anes de los 3 años post-TH. La incidencia del síndrome linfoproliferativo (SLP) fue del 7.69 por ciento, su diagnóstico y tratamiento temprano permitió una evolución favorable en la mayoria de los casos.


Subject(s)
Child , Adolescent , Follow-Up Studies , Indicators of Morbidity and Mortality , Liver Transplantation/adverse effects , Data Interpretation, Statistical
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