Evaluación del proceso de atención urológica de pacientes pediátricos con mielomeningocele / Evaluation of the urological care process of pediatric patients with myelomeningocele

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)

Associations between endocrine disrupting chemicals and equine metabolic syndrome phenotypes.

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.

Structural studies of substrate and product complexes of 5-aminolaevulinic acid dehydratase from humans, Escherichia coli and the hyperthermophile Pyrobaculum calidifontis.

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.

A male genital tract-specific carbohydrate epitope on human CD52: implications for immunocontraception.

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.

5-Aminolaevulinic acid dehydratase: metals, mutants and mechanism.

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.

Trasplante hepático. Seguimiento a largo plazo / Liver transplantation. Long term follow up

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.

Differential nuclear localization of the cancer/testis-associated protein, SPAN-X/CTp11, in transfected cells and in 50% of human spermatozoa.

Cancer-testis antigens (CTAs) represent potential targets for cancer immunotherapy because these proteins are widely distributed in tumors but not in normal tissues, except testes. In this paper, we identify homology of the CTA CTp11 with SPAN-X (sperm protein associated with the nucleus mapped to the X chromosome). On two-dimensional Western blots of human sperm extracts, SPAN-X antibodies recognized 19 spots ranging from 20 to 23 kDa with isoelectric points from 5.0 to 5.5. Differential extraction of spermatozoa demonstrated that the SPAN-X protein is highly insoluble. Only 50% of ejaculated spermatozoa exhibited SPAN-X immunofluorescent staining. Dual localization of the sex chromosomes and the SPAN-X protein demonstrated that an equal number of X- and Y-bearing spermatozoa exhibited SPAN-X staining. In transfected mammalian CV1 cells, the SPAN-Xa and SPAN-Xb proteins were localized to the nucleus and cytoplasm, respectively, by indirect immunofluorescence. On immunoblots of CV1 cells, the SPAN-Xa protein migrated at 15-20 kDa, whereas the SPAN-Xb protein migrated at a higher molecular weight of 21-22 kDa. The SPAN-X protein was ultrastructurally associated with nuclear vacuoles and the redundant nuclear envelope. SPAN-X is the first protein specifically localized to these poorly characterized structures of the mammalian sperm nucleus and provides a unique biochemical marker for investigation of their function in spermatozoa as well as the role of SPAN-X/CTp11 in human tumors.

Anti-sperm antibodies from infertile patients and their cognate sperm antigens: a review. Identity between SAGA-1, the H6-3C4 antigen, and CD52.

PROBLEM: The correlation of anti-sperm antibodies (ASA) with some instances of unexplained infertility implicates a role for these antibodies in blocking fertilization. Improved diagnosis and treatment of immunologic infertility, as well as a more complete understanding of the mechanism behind this phenomenon, are dependent on the identification and characterization of relevant sperm antigens. METHOD OF STUDY: In this article, we review literature on methods employed to identify sperm antigens using anti-sperm polyclonal and monoclonal antibodies from infertile patients and vasectomized men. Particular focus is given to approaches using human and mouse monoclonal antibodies to define the SAGA-1 human sperm antigen. RESULTS: ASA present in sera and genital tract secretions from infertile patients and vasectomized men have been employed in a variety of methods to identify sperm antigens. In an alternate approach, a monoclonal antibody (mAb), H6-3C4, was immortalized from the lymphocytes of an infertile woman who exhibited sperm-immobilizing titers. Subsequently, the sperm-agglutinating, murine S19 mAb was shown to react with the H6-3C4 cognate antigen. The H6-3C4 S19 cognate antigen, designated Sperm Agglutination Antigen-1 (SAGA-1), was characterized as a polymorphic, highly acidic, GPI-anchored glycoprotein on the surface of human spermatozoa. Purification with the S19 mAb followed by microsequencing demonstrated that the SAGA-1 core peptide is identical to CD52, a glycoprotein on the surface of human lymphocytes. Immunoblot analysis demonstrated that these two glycoproteins differed in carbohydrate composition. Thus, sperm SAGA-1 and lymphocyte CD52 represent glycoforms, glycoproteins with the same core peptide but with different carbohydrate structures. CONCLUSIONS: Autoimmunity to the SAGA-1 and/or CD52 glycoforms may lead to infertility. Structural and immunologic differences between these glycoproteins may be important factors in the etiology of immunologic infertility and other autoimmune disorders.

Evidence for a unique N-linked glycan associated with human infertility on sperm CD52: a candidate contraceptive vaccinogen.

A major objective in developing a sperm antigen-based contraceptive vaccine for humans is the discovery of sperm surface immunogens that are functionally relevant and sperm specific. The latter criterion is deemed essential to avoid the possibility of inducing autoimmune disease upon vaccination. This review presents evidence that a unique carbohydrate epitope is synthesized in the human epididymis, is attached to the core peptide of CD52, a lymphocyte differentiation marker, and is subsequently inserted into the sperm membrane via a glycosylphosphatidylinositol anchor. This unique CD52 glycoform is localized to the entire sperm surface, functions as a potent target for agglutinating and cytotoxic antibodies, and is one of the few well-defined sperm surface glycoproteins indicated in human antibody-mediated infertility.

N-linked glycan of a sperm CD52 glycoform associated with human infertility.

In a benchmark study, Isojima and colleagues established H6-3C4, the first successful heterohybridoma immortalized from the peripheral blood lymphocytes of an infertile woman who exhibited high sperm-immobilizing antibody titers. The present report demonstrates the identity between the glycoprotein antigens recognized by the human H6-3C4 monoclonal antibody (mAb) and the murine S19 mAb, generated in our laboratory to sperm agglutination antigen-1 (SAGA-1). Both mAb's recognize N-linked carbohydrate epitopes on the 15-25 kDa, polymorphic SAGA-1 glycoprotein that is localized to all domains of the human sperm surface. Treatment with phosphatidylinositol-specific phospholipase C demonstrated that SAGA-1 is anchored in the sperm plasmalemma via a GPI-lipid linkage. Immunoaffinity purification and microsequencing indicated that the core peptide of the SAGA-1 glycoprotein is identical to the sequence of CD52, a GPI-anchored lymphocyte differentiation marker implicated in signal transduction. Comparison of anti-SAGA-1 and anti-CD52 immunoreactivities revealed that the sperm form of CD52 exhibits N-linked glycan epitopes, including the epitope recognized by the infertility-associated H6-3C4 mAb, which are not detected on lymphocyte CD52. Thus, the two populations of the CD52 glycoprotein on lymphocytes and spermatozoa represent glycoforms, glycoprotein isoforms with the same core amino acid sequence but different carbohydrate structures. Furthermore, mAb's to the unique carbohydrate epitopes on sperm CD52 have multiple inhibitory effects on sperm function, including a cytotoxic effect on spermatozoa in the presence of complement. These results are the first to implicate unique carbohydrate moieties of a sperm CD52 glycoform as target epitopes in the anti-sperm immune response of an infertile woman. Furthermore, localization of CD52 on all domains of the sperm surface coupled with the multiple sperm-inhibitory effects of antibodies to its unique carbohydrate moieties suggest opportunities for immunocontraceptive development.

X-ray structure of 5-aminolevulinic acid dehydratase from Escherichia coli complexed with the inhibitor levulinic acid at 2.0 A resolution.

5-Aminolevulinic acid dehydratase (ALAD), an early enzyme of the tetrapyrrole biosynthesis pathway, catalyzes the dimerization of 5-aminolevulinic acid to form the pyrrole, porphobilinogen. ALAD from Escherichia coli is shown to form a homo-octameric structure with 422 symmetry in which each subunit adopts the TIM barrel fold with a 30-residue N-terminal arm. Pairs of monomers associate with their arms wrapped around each other. Four of these dimers interact, principally via their arm regions, to form octamers in which each active site is located on the surface. The active site contains two lysine residues (195 and 247), one of which (Lys 247) forms a Schiff base link with the bound substrate analogue, levulinic acid. Of the two substrate binding sites (referred to as A and P), our analysis defines the residues forming the P-site, which is where the first ALA molecule to associate with the enzyme binds. The carboxyl group of the levulinic acid moiety forms hydrogen bonds with the side chains of Ser 273 and Tyr 312. In proximity to the levulinic acid is a zinc binding site formed by three cysteines (Cys 120, 122, and 130) and a solvent molecule. We infer that the second substrate binding site (or A-site) is located between the triple-cysteine zinc site and the bound levulinic acid moiety. Two invariant arginine residues in a loop covering the active site (Arg 205 and Arg 216) appear to be appropriately placed to bind the carboxylate of the A-site substrate. Another metal binding site, close to the active site flap, in which a putative zinc ion is coordinated by a carboxyl and five solvent molecules may account for the activating properties of magnesium ions.

The effect of hospital volume on the in-hospital complication rate in knee replacement patients.

OBJECTIVE: To examine the effect of hospital volume on in-hospital surgical outcomes for knee replacement using six years of Medicare claims data. DATA SOURCES/STUDY SETTING: The data include inpatient claims for a 100 percent sample of Medicare patients who underwent primary knee replacement during 1985-1990. We supplemented these data with information from HCFA's denominator files, the Area Resource File, and the American Hospital Association survey files. STUDY DESIGN: We estimated the probability that a patient has an in-hospital complication in the initial hospitalization for the first primary knee replacement, using a Logit model, for three definitions of complication. The models controlled for hospital volume, other hospital characteristics, patient demographics, and patient health status. We tested for the endogeneity of hospital volume. DATA COLLECTION/EXTRACTION METHODS: A panel of two orthopaedic surgeons and two internists reviewed diagnosis codes to determine whether a complication was likely, possible, or due to anemia. After removing the few observations with bad or missing data, the final population has 295,473 observations. PRINCIPAL FINDINGS: The probability of a likely in-hospital complication declines rapidly from 53 through 107 operations per year, then levels off. Statistical tests imply that hospital volume is exogenous in this patient-level data. Complication rates increased steadily through the study period. Although obesity appeared to lower the probability of a complication, a counterintuitive result, further investigation revealed this to be an artifact of the claims data limit of listing no more than five diagnoses. Controlling for this restriction reversed the effect of obesity. CONCLUSIONS: Rather than uncontrolled expansion of knee surgery to small hospitals, decentralization to regional centers where at least about 50, and preferably about 100, operations per year are assured appears to be the optimal policy to reduce in-hospital complications.

Controlling for the endogeneity of peer substance use on adolescent alcohol and tobacco use.

This study examines whether the effects of peer substance use on adolescent alcohol and tobacco use are due to endogeneity of adolescents selecting their peer group. We analyzed data collected for a longitudinal analysis of a drug-use prevention programme for upper elementary school students. We used a two-step probit regression to control for the potentially endogenous explanatory variable peer substance use. Rigorous tests of endogeneity and the validity of the instrumental variables showed that controlling for the endogeneity of peer substance use to reduce bias is not worth the reduction in mean squared error in these data. Peer substance use has a positive and significant effect on adolescent substance use for both drinking and smoking. These results imply that peer influence is empirically more important than peer selection (endogeneity) in our sample of adolescents in grades 6-9. Living in a single-parent family was by far the strongest predictor of adolescent drinking and smoking.

School and neighborhood characteristics associated with school rates of alcohol, cigarette, and marijuana use.

Previous research has noted that schools vary in substance use prevalence rates, but explanations for school differences have received little empirical attention. We assess variability across elementary schools (N = 36) in rates of early adolescent alcohol, cigarette, and marijuana use. Characteristics of neighborhoods and schools potentially related to school prevalence rates are examined, as well as whether these characteristics have independent effects or whether neighborhood characteristics are mediated by school characteristics. Neighborhood and school characteristics were measured using student, parent, and archival data. The findings show substantial variation across schools in substance use. Attributes of neighborhoods and schools are statistically significantly related to school rates of lifetime alcohol use, lifetime cigarette use, and current cigarette use. Contrary to expectations, lifetime alcohol and cigarette use rates are higher in schools located in neighborhoods having greater social advantages as indicated by the perceptions of residents and archival data. Neighborhood effects are expressed both directly and indirectly through school characteristics. The findings are discussed in light of contagion and social disorganization theories.

Protection of mice and swine from pseudorabies virus conferred by vaccinia virus-based recombinants.

Glycoproteins gp50, gII, and gIII of pseudorabies virus (PRV) were expressed either individually or in combination by vaccinia virus recombinants. In vitro analysis by immunoprecipitation and immunofluorescence demonstrated the expression of a gII protein of approximately 120 kDa that was proteolytically processed to the gIIb (67- to 74-kDa) and gIIc (58-kDa) mature protein species similar to those observed in PRV-infected cells. Additionally, the proper expression of the 90-kDa gIII and 50-kDa gp50 was observed. All three of these PRV-derived glycoproteins were detectable on the surface of vaccinia virus-PRV recombinant-infected cells. In vivo, mice were protected against a virulent PRV challenge after immunization with the PRV glycoprotein-expressing vaccinia virus recombinants. The coexpression of gII and gIII by a single vaccinia virus recombinant resulted in a significantly reduced vaccination dose required to protect mice against PRV challenge. Inoculation of piglets with the various vaccinia virus-PRV glycoprotein recombinants also resulted in protection against virulent PRV challenge as measured by weight gain. The simultaneous expression of gII and gp50 in swine resulted in a significantly enhanced level of protection as evaluated by weight evolution following challenge with live PRV.