International Standards for Neurological Classification of Spinal Cord Injury: cases with classification challenges.

The International Standards for the Neurological Classification of Spinal Cord Injury (ISNCSCI) is routinely used to determine the levels of injury and to classify the severity of the injury. Questions are often posed to the International Standards Committee of the American Spinal Injury Association regarding the classification. The committee felt that disseminating some of the challenging questions posed, as well as the responses, would be of benefit for professionals utilizing the ISNCSCI. Case scenarios that were submitted to the committee are presented with the responses as well as the thought processes considered by the committee members. The importance of this documentation is to clarify some points as well as update the SCI community regarding possible revisions that will be needed in the future based upon some rules that require clarification.

International standards for neurological classification of spinal cord injury: cases with classification challenges.

The International Standards for the Neurological Classification of Spinal Cord Injury (ISNCSCI) is routinely used to determine levels of injury and to classify the severity of the injury. Questions are often posed to the International Standards Committee of the American Spinal Injury Association (ASIA) regarding the classification. The committee felt that disseminating some of the challenging questions posed, as well as the responses, would be of benefit for professionals utilizing the ISNCSCI. Case scenarios that were submitted to the committee are presented with the responses as well as the thought processes considered by the committee members. The importance of this documentation is to clarify some points as well as update the SCI community regarding possible revisions that will be needed in the future based upon some rules that require clarification.

Induction of autoimmune diabetes in non-obese diabetic mice requires interleukin-21-dependent activation of autoreactive CD8⁺ T cells.

Non-obese diabetic (NOD) mice lacking interleukin (IL)-21 or IL-21 receptor do not develop autoimmune type 1 diabetes (T1D). We have shown recently that IL-21 may promote activation of autoreactive CD8(+) T cells by increasing their antigen responsiveness. To investigate the role of IL-21 in activating diabetogenic CD8(+) T cells in the NOD mouse, we generated IL-21-deficient NOD mice expressing the highly pathogenic major histocompatibility complex (MHC) class-I-restricted 8.3 transgenic T cell receptor (TCR). IL-21 deficiency protected 8.3-NOD mice completely from T1D. CD8(+) T cells from the 8.3-NOD.Il21(-/-) mice showed decreased antigen-induced proliferation but displayed robust antigen-specific cytolytic activity and production of effector cytokines. IL-21-deficient 8.3 T cells underwent efficient homeostatic proliferation, and previous antigen stimulation enabled these cells to cause diabetes in NOD.Scid recipients. The 8.3 T cells that developed in an IL-21-deficient environment showed impaired antigen-specific proliferation in vivo even in IL-21-sufficient mice. These cells also showed impaired IL-2 production and Il2 gene transcription following antigen stimulation. However, IL-2 addition failed to reverse their impaired proliferation completely. These findings indicate that IL-21 is required for efficient initial activation of autoreactive CD8(+) T cells but is dispensable for the activated cells to develop effector functions and cause disease. Hence, therapeutic targeting of IL-21 in T1D may inhibit activation of naive autoreactive CD8(+) T cells, but may have to be combined with other strategies to inhibit already activated cells.

Compliance with AZT treatment regimen of HIV-seropositive injection drug users: a neglected issue.

Although treatment with zidovudine (AZT) is now recommended for asymptomatic and symptomatic HIV-infected persons with CD4+ cell counts of 0.20 to 0.50 x 10(9)/L and under, data gathered from a small convenience sample of current and former injection drug users with AIDS in the New York City metropolitan region suggest that noncompliance with HIV/AIDS-related therapeutic regimen may be common in this population. This paper enumerates the reasons for noncompliance offered by these informants, reviews the general literature on treatment compliance to identify additional potential reasons for non-adherence to AZT treatment regimen, and outlines some suggestions for future research into this important issue that may prompt changes in the antiviral delivery system.

Seroprevalence and risk factors associated with HTLV-I/II infection in injection drug users in northern New Jersey.

Data from an AIDS Demonstration Research project in Paterson, NJ, that enrolled out-of-treatment injection drug users (IDUs) were analyzed to detect demographic patterns and risk factors associated with infection with human immunodeficiency virus (HIV) and human T-lymphotropic virus types I or II (HTLV-I/II). Of 410 IDUs screened, 44.2% were HIV-positive and 19.3% were HTLV-I/II-positive. African-Americans were significantly more likely than other racial groups to be HTLV-I/II-seropositive and to be HIV-seropositive. Over one-fifth of African-Americans--but no Latinos or whites--were doubly infected with HIV and HTLV-I/II. In logistic regression analysis, African-American race, long-term injection drug use, and age were significant predictors of HTLV-I/II-seropositivity. While the associations between recent needle practices and HTLV-I/II-seropositivity fell short of significance, the trends in the data were consistent with a hypothesis that HTLV-I/II is transmitted through the sharing of injection equipment. Public health implications of the data are discussed.

[Brucellar hepatic abscess: resolution with antibiotic treatment]. / Absceso hepático brucelar: resolución con tratamiento antibiótico.

Liver damage in Brucellosis is in the form of granulomas and the finding of liver abscess is not frequent. Most of the cases reported in the medical literature have been described in Spain. The treatment was surgery. We present a hepatic abscess due to Brucellosis that responded to medical treatment. For we discuss the indication of surgery in the case described.

[Acute pancreatitis with fluid collections complicated with cutaneous fistula]. / Pancreatitis aguda necrotizante con colecciones líquidas complicadas con fístulas cutáneas.

The presence of acute fluid collections is an habitual event in an acute pancreatitis, generally followed by a favourable outcome. We present a case about an ancient woman suffering from an acute necrotizing pancreatitis with tense fluid collections that produced espontaneously several cutaneous fistula. We find no report on literature about this uncommon complication. We revised clinical management of acute fluid collections and pancreatic fistulas.

[Role of direct radionuclide cystography and renal study by dimercaptosuccinic acid (DMSA) in the diagnosis and follow-up of vesicoureteral reflux]. / La cistografía isotópica directa y la gammagrafía renal con ácido dimercaptosuccínico (DMSA) en el diagnóstico y seguimiento del reflujo vesicoureteral.

AIM: To evaluate the role of isotopic studies in the diagnosis and follow-up of vesicoureteral reflux (VUR) and to present the results of our current protocol. MATERIAL AND METHODS: Forty three patients with VUR were retrospectively studied with a mean follow-up of 43 years (1-11 years). VUR was diagnosed by voiding cystourethrography and followed-up by direct radionuclide cystography. During the follow-up all patients were studied by means of renal DMSA scintigraphy (21 were also studied during the acute phase of febrile urinary tract infection). RESULTS: Eighty three renal units were examined. Voiding cystourethrography was positive for VUR in 49 renal units (59%; 8 grade I, 18 grade II, 15 grade III, and 8 grade IV). During the follow-up, direct radionuclide cystography showed decrease or disappearance of VUR in 29 renal units (35%; 4 grade I, 16 grade II, 7 grade III, and 2 grade IV). DMSA studies performed during the follow-up showed cortical lesions in 17 renal units (5 with VUR grade II, 7 with grade III, and 5 grade IV). Nine of 21 patients examined by DMSA during the acute phase of febrile urinary tract infection showed cortical damage (43%), and 6 of them (67%) progressed to cortical lesion in the follow-up DMSA. CONCLUSIONS: The present protocol allows for the correct diagnosis and control of VUR, the early detection of acute renal damage, and the control of its evolution.

[Consensus document: recommendations for the use of equations to estimate glomerular filtration rate in children]. / Documento de consenso: recomendaciones sobre la utilización de ecuaciones para la estimación del filtrado glomerular en niños.

The appearance of the K/DOQI guidelines in 2002 on the definition, evaluation and staging of chronic kidney disease (CKD) have led to a major change in how to assess renal function in adults and children. These guidelines, recently updated, recommended that the study of renal function is based, not only on measuring the serum creatinine concentration, but this must be accompanied by the estimation of glomerular filtration rate (GFR) obtained by an equation. However, the implementation of this recommendation in the clinical laboratory reports in the paediatric population has been negligible. Numerous studies have appeared in recent years on the importance of screening and monitoring of patients with CKD, the emergence of new equations for estimating GFR, and advances in clinical laboratories regarding the methods for measuring plasma creatinine and cystatin C, determined by the collaboration between the departments of paediatrics and clinical laboratories to establish recommendations based on the best scientific evidence on the use of equations to estimate GFR in this population. The purpose of this document is to provide recommendations on the evaluation of renal function and the use of equations to estimate GFR in children from birth to 18 years of age. The recipients of these recommendations are paediatricians, nephrologists, clinical biochemistry, clinical analysts, and all health professionals involved in the study and evaluation of renal function in this group of patients.

Documento de consenso: recomendaciones sobre la utilización de ecuaciones para la estimación del filtrado glomerular en niños / Consensus document: Recommendations for the use of equations to estimate glomerular filtration rate in children

La aparición de las guías K/DOQI en el año 2002 sobre definición, evaluación y clasificación en estadios de la enfermedad renal crónica (ERC) han supuesto un cambio importante en la forma de evaluar la función renal en adultos y en niños. Estas guías, recientemente actualizadas, recomiendan que el estudio de la función renal se realice a partir de la medida de la concentración sérica de creatinina y de la estimación del filtrado glomerular (FG) obtenido mediante una ecuación. Sin embargo, la implementación de esta recomendación en los informes del laboratorio clínico en población pediátrica ha sido casi nula. Los estudios aparecidos en los últimos años sobre la importancia de la detección y seguimiento de los pacientes con ERC, la aparición de nuevas ecuaciones de estimación del FG y los avances en los laboratorios clínicos respecto a los métodos de medida de creatinina y de cistatina C han determinado la colaboración entre los servicios de pediatría y de los laboratorios clínicos con objeto de establecer recomendaciones homogéneas y basadas en la mejor evidencia científica sobre la utilización de las ecuaciones de estimación del FG en este grupo de población. El objetivo de este documento es proporcionar recomendaciones sobre la evaluación de la función renal y la utilización de ecuaciones de estimación del FG en niños. Los destinatarios de estas recomendaciones son los pediatras, nefrólogos, bioquímicos clínicos, analistas clínicos y todos los profesionales de la salud relacionados con el estudio y la evaluación de la función renal de este grupo de pacientes (AU)

The appearance of the K/DOQI guidelines in 2002 on the definition, evaluation and staging of chronic kidney disease (CKD) have led to a major change in how to assess renal function in adults and children. These guidelines, recently updated, recommended that the study of renal function is based, not only on measuring the serum creatinine concentration, but this must be accompanied by the estimation of glomerular filtration rate (GFR) obtained by an equation. However, the implementation of this recommendation in the clinical laboratory reports in the paediatric population has been negligible. Numerous studies have appeared in recent years on the importance of screening and monitoring of patients with CKD, the emergence of new equations for estimating GFR, and advances in clinical laboratories regarding the methods for measuring plasma creatinine and cystatin C, determined by the collaboration between the departments of paediatrics and clinical laboratories to establish recommendations based on the best scientific evidence on the use of equations to estimate GFR in this population. The purpose of this document is to provide recommendations on the evaluation of renal function and the use of equations to estimate GFR in children from birth to 18 years of age. The recipients of these recommendations are paediatricians, nephrologists, clinical biochemistry, clinical analysts, and all health professionals involved in the study and evaluation of renal function in this group of patients (AU)

Destructive proteolysis by cysteine proteases in antigen presentation of ovalbumin.

Most native antigens require digestion by acidic proteases in order to be recognized in the context of major histocompatibility complex class II by T helper cells (Th). We have studied the roles of three different acidic proteases, cathepsin D, cathepsin B and cathepsin L, in the processing of ovalbumin (OVA) for presentation in the context of I-Ad. We report that digestion of OVA in vitro with the aspartyl protease cathepsin D generates the epitope OVA322-336, which is recognized by I-Ad-restricted OVA-specific Th in the presence of paraformaldehyde-fixed antigen-presenting cells (APC). In contrast, digestion of OVA with the cysteine proteases cathepsin B and L not only failed to generate an epitope, but also destroyed OVA322-336. In the presence of fixed APC expressing I-Ad. OVA322-336 was protected from destructive proteolysis by cathepsin L. These results illustrate the dependence of epitope selection on the intracellular proteolytic environment in APC, and suggest that mechanisms must exist for protection of epitopes from destructive proteolysis in the processing compartments.

Role of cathepsin D in antigen presentation of ovalbumin.

Modification of protein Ag by proteolysis is one of the principal steps in the presentation of Ag to Th cells. However, little is known about the enzymes participating in these events, their specificity or the characteristics of the natural fragments that they produce. Cathepsin D (CD) is an aspartyl protease identified in endosomes of APC. In this report, the role of CD in the processing of OVA has been investigated. OVA digested in vitro with purified CD was able to stimulate IL-2 secretion by three different OVA-specific I-Ad restricted Th cell hybridomas when it was presented by fixed APC. The digest of OVA was recognized in the context of I-Ad, but not by I-Ak-restricted OVA-specific Th cells. No difference was observed in the ability of OVA digested with CD to stimulate Th cells in the absence of FCS or in the presence of protease inhibitors indicating that extracellular proteases were not likely to contribute to processing of OVA. Taken together, these results suggest that CD is necessary and sufficient for the generation of an antigenic epitope from OVA. A fragment containing the epitope was isolated from the OVA digest by reverse phase HPLC. This fragment, which migrates in SDS-PAGE as a 10-kDa polypeptide, is a potent epitope. Its capacity to activate Th cells is compared to that of the tryptic peptide OVA323-339.

A comparison of male and female intravenous drug users' risk behaviors for HIV infection.

Despite the central role played by female intravenous drug users (IVDUs) in the worsening AIDS statistics of states in the northeastern United States, the relative paucity of research into the HIV risk behaviors--particularly risky needle practices--of female drug injections has left significant gaps in researchers' understanding of how and to what extent such women may differ in their risks from their better-studied male counterparts. This study, derived from a sample of 769 out-of-treatment IVDUs residing in an area (Paterson, New Jersey) characterized by high levels of AIDS and HIV infection among drug users, attempts to address this lacuna in the research literature by comparing the drug usage, AIDS knowledge, and needle and sexual behaviors of male and female IVDUs that place them at risk for HIV infection. In this sample, gender was found to be unrelated to HIV serostatus, injection frequency and injected drug of choice, and to most dimensions of knowledge about AIDS and the means of HIV transmission. Overall, it appears that the average Paterson female IVDU may be at greater risk for HIV infection as a result of involvement with a drug-using sex partner than because of especially risky needle practices, for females in this sample were significantly more likely than males to report injecting with a sex partner in the previous 6 months, and female IVDUs with one sex partner were more than twice as likely as males with one partner to report that this individual was an IVDU. Condom use was relatively rare, particularly among those with one partner. Moreover, female IVDUs were significantly more likely than males to be daily users of crack cocaine, and significantly more likely to report poorer health. However, current needle and sexual practices were found to be unrelated to HIV seropositivity among both males and females. In logistic regression analysis, only length of IV drug involvement was found to be independently associated with HIV seropositivity for both sexes. Implications of the data for future prevention efforts aimed at female IVDUs are discussed.

Identification and characterization of two divergently transcribed iron regulated genes in Mycobacterium tuberculosis.

SETTING: Low iron availability in the host induces the expression of iron acquisition systems and virulence genes in many pathogens. IdeR is a mycobacterial iron dependent regulator that controls the iron starvation and oxidative stress responses in Mycobacterium smegmatis. It is important to determine the role of IdeR and its regulon in M. tuberculosis, as identification of iron regulated genes can aid in the design of new drugs and generation of attenuated strains. OBJECTIVE: A potential IdeR binding site was found in the M. tuberculosis genome flanked by two divergently oriented open reading frames, irg1 and irg2. The aim of this study was to determine whether irg1 and irg2 were iron and IdeR regulated genes. DESIGN: Interaction of IdeR with the putative binding sequence was examined by gel shift and footprinting assays. Transcriptional fusions of irg1 and irg2 to IacZ were used to study the effect of iron levels on the expression of these genes. RESULTS: IdeR binds to the predicted binding site, which overlaps with the irg1 promoter. irg1 and irg2 expression was decreased by iron in M. tuberculosis and in wild type M. smegmatis, but not in a M. smegmatis ideR mutant. CONCLUSION: Two M. tuberculosis iron/IdeR regulated genes were identified. irg1 is predicted to be the M. tuberculosis hisE gene, which is involved in histidine biosynthesis. It is directly upstream of the M. tuberculosis hisG. irg2 encodes a putative membrane protein that is a member of the PPE family.

The Mycobacterium tuberculosis IdeR is a dual functional regulator that controls transcription of genes involved in iron acquisition, iron storage and survival in macrophages.

In this work, we characterize genes in Mycobacterium tuberculosis that are regulated by IdeR (iron-dependent regulator), an iron-responsive DNA-binding protein of the DtxR family that has been shown to regulate iron acquisition in Mycobacterium smegmatis. To identify some of the genes that constitute the IdeR regulon, we searched the M. tuberculosis genome for promoter regions containing the consensus IdeR/DxR binding sequence. Genes preceded by IdeR boxes included a set encoding proteins necessary for iron acquisition, such as the biosynthesis of siderophores (mbtA, mbtB, mbtI), aromatic amino acids (pheA, hisE, hisB-like) and others annotated to be involved in the synthesis of iron-storage proteins (bfrA, bfrB). Some putative IdeR-regulated genes identified in this search encoded proteins predicted to be engaged in the biosynthesis of lipopolysaccharide (LPS)-like molecules (rv3402c), lipids (acpP) and peptidoglycan (murB). We analysed four promoter regions containing putative IdeR boxes, mbtA-mbtB, mbI, rv3402c and bfrA-bfd, for interaction with IdeR and for iron-dependent expression. Gel retardation experiments and DNase footprinting analyses with purified IdeR showed that IdeR binds to these IdeR boxes in vitro. Analysis of the promoters by primer extension indicated that the IdeR boxes are located near the -10 position of each promoter, suggesting that IdeR acts as a transcriptional repressor by blocking RNA polymerase binding. Using quantitative reverse transcriptase-polymerase chain reaction (RT-PCR) coupled to molecular beacons, we showed that mRNA levels of mbtA, mbtB, mbtI, rv3402c and bfd are induced 14- to 49-fold in cultures of M. tuberculosis starved for iron, whereas mRNA levels of bfrA decreased about threefold. We present evidence that IdeR not only acts as a transcriptional repressor but also functions as an activator of bfrA. Three of the IdeR- and iron-repressed genes, mbtB, mbtI and rv3402c, were induced during M. tuberculosis infection of human THP-1 macrophages.

Lysosomal hydrolases are present in melanosomes and are elevated in melanizing cells.

Melanosomes, the subcellular site of melanin synthesis and deposition, may be related to the endolysosomal lineage of organelles. To determine if melanosomes contain lysosomal hydrolases, we examined the subcellular distribution of five of these enzymes in melanocytes cultured from C57BL/6J mice. Analyses of Percoll gradient density centrifugations demonstrated that beta-hexosaminidase, beta-galactosidase, beta-glucuronidase, and cathepsins B and L all co-sedimented with tyrosinase-rich densely sedimenting melanosomes. The melanosomal distribution of these enzymes was confirmed in studies of melanocytes cultured from albino mice and of melanocytes rendered amelanotic by transfection with the v-rasHa oncogene (which lack dense, melanized melanosomes). In these cells, only a less dense peak of activity for each hydrolase was present. The level of each hydrolase was elevated in black cells when compared with albino cells. Metabolic labeling studies confirmed that the increase in beta-glucuronidase in black versus albino cells resulted mainly from increased synthesis of this enzyme. The data suggest that melanosomes represent specialized lysosomes present within melanocytes, that they contain a broad array of lysosomal hydrolases, and that the levels of these hydrolases are elevated in cells actively engaged in pigment production.