Characterization of the autoimmune response against the nerve tissue S100ß in patients with type 1 diabetes.

Type 1 diabetes results from destruction of insulin-producing beta cells in pancreatic islets and is characterized by islet cell autoimmunity. Autoreactivity against non-beta cell-specific antigens has also been reported, including targeting of the calcium-binding protein S100ß. In preclinical models, reactivity of this type is a key component of the early development of insulitis. To examine the nature of this response in type 1 diabetes, we identified naturally processed and presented peptide epitopes derived from S100ß, determined their affinity for the human leucocyte antigen (HLA)-DRB1*04:01 molecule and studied T cell responses in patients, together with healthy donors. We found that S100ß reactivity, characterized by interferon (IFN)-γ secretion, is a characteristic of type 1 diabetes of varying duration. Our results confirm S100ß as a target of the cellular autoimmune response in type 1 diabetes with the identification of new peptide epitopes targeted during the development of the disease, and support the preclinical findings that autoreactivity against non-beta cell-specific autoantigens may have a role in type 1 diabetes pathogenesis.

Hiperplasia nodular regenerativa del hígado secundaria a uso de azatioprina por trasplante renal previo, tratado con trasplante combinado hepático y renal / Combined hepatic and renal transplant after nodular regenerative hyperplasia of the liver secondary to azathioprine in renal transplant patient

Nodular regenerative hyperplasia is an uncommon condition, characterized by the presence of regenerative nodules with minimal or absence of fibrosis, which can lead to non-cirrhotic portal hypertension. There are numerous diseases, conditions and drugs that can cause it. Thiopurines, a group of immunosuppressors used in transplanted patients, has been linked to this entity. We report a case of a renal transplant woman, who has been on chronic therapy with azathioprine and that develops portal hypertension and end-stage renal disease, undergoing combined hepatic and renal transplant. Histological examination of the explanted liver was compatible with nodular regenerative hyperplasia. How azathioprine causes this entity is unknown, but endothelial vascular damage in a dose-dependent manner is postulated as the main mechanism. To our knowledge, this is the first case report of a renal transplant patient who develops nodular regenerative hyperplasia of the liver in association with azathioprine, and undergoes combined hepatic and renal transplant, with a favorable outcome 5 years post procedure.

La hiperplasia nodular regenerativa es una entidad infrecuente, que se caracteriza por la presencia de nódulos hepáticos con ausencia o mínima fibrosis y que puede llevar a hipertensión portal de origen no cirrótico. Existen diversas enfermedades, condiciones y medicamentos que la causan, destacando entre estos últimos las tiopurinas, inmunosupresores utilizados habitualmente en trasplantados. Se presenta el caso de una paciente trasplantada renal usuaria crónica de azatioprina, que desarrolla hipertensión portal además de deterioro de la función renal, requiriendo de un doble trasplante hepático y renal, destacando en la biopsia del explante hallazgos histológicos compatibles con hiperplasia nodular regenerativa. Los mecanismos de daño por azatioprina en esta entidad son desconocidos, pero se postula al daño endotelial dosis-dependiente como principal causa. La revisión de la literatura demuestra que este caso corresponde al primero de hiperplasia nodular regenerativa secundaria a azatioprina en trasplantado renal, que requiere de doble trasplante hepático y renal con evolución favorable hasta 5 años post trasplante.

Caracterización del nivel de dependencia al alcohol entre habitantes de la Ciudad de México

resumen está disponible en el texto completo

Summary: The dynamic and scope of the consumption of alcoholic beverages, in Mexico, have been known by household surveys, since the last third of the last century. Nowadays those surveys describe alcohol use as one of the main public health tasks nationwide, due not only to its consequences but also to the damage on the different areas of individual's everyday life. A number of indicators have been highlighted by the first survey on 1988, such as teetotalism rates, the alcohol consumers proportion, age of first use, and problems associated with alcohol consumption. As a public health problem, alcohol consumption represents high costs to health institutions because of the problems related to the consumption. So, it requires undertaking certain actions that would be deal with this problem on primary and structural attention, as well as in the individual susceptibility as prevention, or attention levels, diagnosis and treatment. All actions to face this problem are practically impossible in the absence of instruments to establish differential diagnosis between heavy drinking and alcohol dependence. Along the study of alcoholism, have been distinguished two issues to establish differential diagnosis. First is a traditional version of dependence diagnosis by DSM criterions, defined as disadaptative pattern of alcohol consumption that produces significant malaise, expressed trough one year long. The second diagnosis issue quantifies the individual differences of physical, psychological and social damage degrees, caused by the alcohol consumption. From this, appears the motion of Multiple Alcoholism Syndrome. From this last point of view, The Alcohol Use Inventary by Skinner, Horn and Wanberg (1983), is compose by 147 items self administrated, clusted in 24 scales. Time latter, as of many researches done by this research group, aroused The Multiple-syndrome Alcohol Model as The Alcohol Use Inventary simplified version, used as a useful differential diagnosis questionnaire in alcoholics. There for, last version has been done many researches that agree on characterize the alcohol use inventory as screening questionnaire useful to detect problematic drinking to implement primary intervention. Those authors suggest the use of this questionnaire at different stages and populations, with different cut points. Antecedent's use of the questionnaire in Mexico, by Ayala et al., made the adapted version, however, researches seems to be not enough to know the validity of diagnostic instruments on ethanol dependence. The Alcohol Dependence Scale (ADS) consider the dependence as a continuum of four levels, depending on the damage degree associated with alcohol consumption, on the different areas of physical, intellectual, social and psychiatric functioning. In the questionnaire 1 is the minimum cut point for dependence diagnostic and 48 as the highest point, this rank lets differentiate with respect to low dependence, moderate dependence, substantial dependence and severe dependence. This article pretends to diffuse the EDS's validity on inhabitants in Mexico City. As methodology, a case design and 1:1 paired controls were used by age and marital status. Through a not intentioned sampling by quotas were selected 240 men of 18 to 50 years old. The cases group was integrated by 120 individuals that voluntarily sought treatment at the Center of Assistance for the Alcoholic and Relatives (CAAF) from June, 1998 to June, 2000. All cases comply with DSM-IV alcohol dependence criterion; they reported the last consumption at one month before the beginning of the research and with basic school as scholar level. In the control group were 120 volunteers that request treatment to CAAF from June, 1998 to June, 2000. They did not comply with alcohol dependence criterion. As gold standard, was considered the DSM-IV criteria to sensibility, specificity and predictive values; the factorial structure and internal consistency of the scale are indicated. Socio-demographic data indicated 34 years old as sample average, just over the half had a partner at the time of the study; the predominant education level was secondary school (35%). In the cases the 86% covered 6 to 7 criteria for ethanol dependence in the DSM-IV; the predominant dependence level was moderate at 37%, while 53% of the control group had no evidence of dependence. The heterogeneity test showed significant statistics differences on dependence levels in cases and controls (t=23, df=238 and p=0.00). The ADS displays overall internal consistency of 0.96, based on the Cronbach Reliability Coefficient, a higher level of consistency than that reported in previous studies. With a factorial analysis by varimax rotation and maximum likelihood extraction, revealed the presence of three factors with 56.5% of variance explained: intoxication (48.3%), abstinence (5.6%) and delirium tremens. In the application manual, the authors specify 13/14 as values to use the DAS as a diagnosis questionnaire, and 9 for a screening instrument. While other authors suggest less cut points 13/14 to 2/3 to reduce the false-negative; however, on Mexico City inhabitants, such cut points were inappropriate. The most suitable cut point to detect a significant dependence on clinical was at 8 points, with 96% sensitivity, 98% specificity and a 94% likelihood of making correct diagnoses. These findings show that DAS is a suitable screening instrument for using on Mexico City inhabitants. We suggest including items to evaluate social area or any other scale to complement the ADS.

Alteration of the serum levels of the epidermal growth factor receptor and its ligands in patients with non-small cell lung cancer and head and neck carcinoma.

Serum levels of the soluble epidermal growth factor receptor (sEGFR) and its ligands epidermal growth factor (EGF), transforming growth factor-alpha (TGF-alpha) and amphiregulin (AR) were measured in healthy donors and patients with non-small cell lung cancer (NSCLC) and head and neck carcinoma (HNC). In NSCLC, we found sEGFR and EGF levels significantly lowered in patients with respect to healthy donors. In HNC patients, significantly diminished levels were found in the case of sEGFR, EGF and also AR. In both malignancies, no significant association was found between the serum levels of the molecules and the patients' gender, age or smoking habit. Only a significant association was found between the decrease of sEGFR and the absence of distant metastasis in NSCLC and the tumour stage in HNC. The most interesting result was that combining sEGFR and EGF, sensitivities of 88% in NSCLC and 100% in HNC were reached without losing specificity (97.8% in both cases). The use of discriminant analysis and logistic regression improved the sensitivity for NSCLC and the specificity for HNC. These data demonstrate a potentially interesting value of the serum levels of sEGFR and EGF, especially when combined, as markers for NSCLC and HNC.

Identification of receptors for prothymosin alpha on human lymphocytes.

Prothymosin alpha (ProTalpha) is a highly conserved and widely distributed protein whose physiological functions remain elusive. In previous work we identified high and low affinity-binding sites for ProTalpha in lymphoid cells. Here we demonstrate, by affinity cross-linking and affinity chromatography, the existence of three binding partners (31, 29, and 19 kDa) for ProTalpha in the membrane of PHA-activated lymphoblasts. These surface molecules possess the expected affinity and specificity for a ProTalpha receptor. Examination of the expression of this complex of molecules by flow cytometry reveals that they bind ProTalpha in a specific and saturable way. In addition, the distribution of the receptor on the cell surface was studied by fluorescence microscopy; a cap-like structure at one of the poles of the cells was identified. These results represent a new and promising approach in the research on ProTalpha, opening the way toward the understanding of the molecular mechanism of action of this protein.

Cytokines regulate membrane adenosine deaminase on human activated lymphocytes.

CD26 is a lymphocyte marker that can anchor adenosine deaminase (ADA) on the T cell surface. We found that ADA is regulated by cytokines on the cell surface during T cell activation. By means of flow cytometry, immunofluorescence, and immunoblotting techniques, we found that interleukin (IL)-2 and IL-12 up-regulate ecto-ADA and CD26 expression. In clear contrast, IL-4 led to down-regulation of lymphocyte surface ADA without modifying the level of CD26. Moreover, neither circulating ADA transcription nor mRNA translation was regulated by cytokines. These results, along with absence of total-ADA modulation, the variable amount of ADA found in purified plasma membranes, and the different effect of Brefeldin A on the surface presence of ADA and CD26 indicated that cytokines regulate the translocation of ADA towards the cell surface through a mechanism not involving CD26. Ecto-ADA protected activated lymphocytes from the toxic effects of extracellular adenosine. Therefore, this cell surface ADA control might constitute part of the fine immunoregulatory mechanism of adenosine-mediated signaling through purinergic receptors in leukocytes.

Serum interleukin-12, interleukin-15, soluble CD26, and adenosine deaminase in patients with rheumatoid arthritis.

CD26, a transmembrane ectoenzyme, is overexpressed on rheumatoid arthritis (RA) peripheral blood T cells. As it has been recently described that IL-12 and IL-15 upregulate CD26 in vitro, we hypothesized that this CD26 overexpression might be interleukin dependent. The concentrations of IL-12 and IL-15, and soluble CD26 and adenosine deaminase (enzymes related to CD26) were analyzed in the serum of 35 patients with active and inactive RA and of healthy control subjects. IL-12 and IL-15 levels were significantly higher in patients' serum, independently of disease activity, even in patients on steroid therapy, i.e., the present therapies cannot eradicate their origin. Soluble CD26 was significantly reduced and related to the disease activity. In particular, it correlated inversely with the number of swollen joints. Although these data did not support our hypothesis, they support that interleukins not only initiate RA pathology but they can also participate in the maintenance of this immune response.

Cell surface human alpha-L-fucosidase.

The acid alpha-L-fucosidase is usually found as a soluble component of lysosomes where fucoglycoconjugates are degraded. In the present investigation, we have demonstrated the existence of a cell surface protein with enzymatic alpha-L-fucosidase activity that crossreacts specifically with a rabbit anti-(alpha-L-fucosidase) Ig. By different approaches, this alpha-L-fucosidase, which represents 10-20% of the total cellular fucosidase activity, was detected in all the tested human cells (hemopoietic, epithelial, mesenchymal). Two bands of approximately 43-49 kDa were observed, although theoretical data support the possibility of having the same genetic origin that the known 50 to 55-kDa Mr alpha-L-fucosidase. We speculate about an alternative traffic pathway for the plasma membrane alpha-L-fucosidase to work on the rapid turnover of glycoproteins.

Fifteen years of prothymosin alpha: contradictory past and new horizons.

Prothymosin alpha (ProTalpha) is a highly acidic and small protein of only 111 amino acids with an unusual primary structure. One would expected it to play an essential role in the organism, as it has a wide distribution and is high conserved among mammals, yet its exact function remains elusive. Despite the number of effects described for ProTalpha, intracellular and extracellular, none are accepted as its physiological role. Furthermore, many other aspects of its biology still remain obscure. In this review, we discuss the structural properties, location, gene family, functions and immunomodulatory activities of and cellular receptors for ProTalpha. These topics are addressed in an attempt to reconcile opposing outlooks while emphasizing those points where scant investigations do exist. We have also re-evaluated some previous results in light of the structural properties of ProTalpha and have found that molecular mimetism could be the underlying basis. This molecular mimicry hypothesis provides a clue that must not be overlooked for a realistic appraisal of future results.

Preoperative serum CD26 levels: diagnostic efficiency and predictive value for colorectal cancer.

CD26 is an ectoenzyme with dipeptidyl peptidase IV activity expressed on a variety of cell types. Although the function of the high concentration of serum-soluble CD26 (sCD26) is unknown, it may be related to the cleavage of biologically active polypeptides. As CD26 or enzymatic activity levels were previously associated with cancer, we examined the potential diagnostic and prognostic value of preoperative sCD26 measurements by ELISA in colorectal carcinoma patients. We found a highly significant difference between sCD26 levels in healthy donors (mean 559.7 +/- 125.5 microg l(-1)) and cancer patients (mean 261.7 +/- 138.1 microg l(-1)) (P< 0.001). A cut-off at 410 microg l(-1)gave 90% sensitivity with 90% specificity which means that the diagnostic efficiency of sCD26 is higher than that shown by other markers, particularly in patients at early stages. Moreover, sCD26 as a variable is not related with Dukes' stage classification, age, gender, tumour location or degree of differentiation. With a follow-up of 2 years until recurrence, preliminary data show that sCD26 can be managed as a prognostic variable of early carcinoma patients. In addition, the origin of sCD26 is discussed.

Mechanisms of CD26/dipeptidyl peptidase IV cytokine-dependent regulation on human activated lymphocytes.

Among the cellular pathways activated by IL-12, we had previously found that both the percentage and intensity of CD26(+)cells in the PHA-stimulated T cells increased when IL-12 was present (independently of its CD4 or CD8 phenotype). Now, we examined the molecular mechanisms of this IL-12-mediated effect. The IL-12 regulation pathway is dependent of de novo protein synthesis and independent of cytokine secretion. Our results show two transcripts for CD26 in PBMC for the first time and no regulation by ILs at this level. Furthermore, secretion of the serum forms of CD26/DPPIV were not affected by IL-12. Interestingly, assays with neutralizing mAbs against TNF-alpha suggest that this cytokine negatively modulates CD26 expression. The fact that translation and probably translocation of CD26 toward the cell surface can be regulated by IL-12 and TNF-alpha reveals new aspects about the control of this T(H1)marker.

[The prevalence of urinary incontinence in a population over 60 treated in primary care]. / Prevalencia de incontinencia urinaria en la población mayor de 60 años atendida en atención primaria.

OBJECTIVES: To determine the prevalence of urine incontinence (UI) among the over-60 population treated in primary care, identifying the types and associated epidemiological factors. DESIGN: Descriptive and crossover. SETTING: Primary care. PATIENTS: Sample of 400 people aged 60 or over, stratified by sex and chosen from those who attended their health centre spontaneously for a consultation. MEASUREMENTS AND RESULTS: Age, sex, chronic illnesses, treatments, previous childbirths, grade of immobility and presence or absence of involuntary discharge of urine. If the reply was positive: frequency, characteristics and evolution of UI, and prior consultations on the problem were also measured. 400 people (254 women and 146 men). Mean age: 71 (SD = 7.3 years). 145 people (36.2%) recognised they had UI. 43.3% of women and 23.9% of men (p < 0.001) were incontinent. UI prevalence increased with age: 31.7% among the 60-69 year old group; 35% among the 70-79 group; and 53.3% in those over 80. Among women the most common types are stress and urge incontinence, whereas among men the most common are urge and overflow UI. UI prevalence is greater among women with previous childbirths and among immobile patients. Of the 145 people who recognised their UI, only 31 (21.3%) had previously consulted the doctor on this problem, although men had consulted significantly more than women (40% vs. 15.4%; p < 0.01). CONCLUSIONS: Over a third of the people over 60 in our clinics suffer from UI. Prevalence increases with age and is greater among women, especially if there is a history of childbirth. Urge UI predominates among men and stress UI among women. Most people with UI do not consult concerning their problem, for which reason, so as to identify it and adopt corrective measures, women especially must be systematically asked about the symptom.

Thymic peptides and preparations: an update.

The possibilities of thymic peptides in human therapy are still being described. Here, we focus on their general characteristics and on recent advances in this area.

Expression of A2B adenosine receptors in human lymphocytes: their role in T cell activation.

Extracellular adenosine has a key role in the development and function of the cells of the immune system. Many of the adenosine actions seem to be mediated by specific surface receptors positively coupled to adenylate cyclase: A2A and A2B. Despite the fact that A2A receptors (A2ARs) can be easily studied due to the availability of the specific agonist CGS21680, a pharmacological and physiological characterization of adenosine A2B receptors (A2BRs) in lymphocytes has not been possible due to the lack of suitable reagents. Here we report the generation and characterization of a polyclonal antipeptide antibody raised against the third extracellular loop of the A2BR human clone which is useful for immunocytochemical studies. This antibody has permitted the detection of A2BR+ cells in lymphocyte samples isolated from human peripheral blood. The pharmacology of cAMP-producing compounds is consistent with the presence of functional A2BRs but not of A2A receptors in these human cells. The percentage of A2BR-expressing cells was similar in the CD4(+) or CD8(+) T cell subpopulations. Interestingly activation signals delivered by either phytohemagglutinin or anti-T cell receptor/CD3 complex antibodies led to a significant increase in both the percentage of cells expressing the receptor and the intensity of the labeling. These receptors are functional since interleukin-2 production in these cells is reduced by NECA but not by R-PIA or CGS21680. These results show that A2BR expression is regulated in T cell activation and suggest that the role of adenosine in lymphocyte deactivation is mediated by A2BRs.

Interleukin-12-dependent activation of human lymphocyte subsets.

Recently, we reported that IL-12 increased expression and function of CD26/DPPIV, this may be a new cellular pathway of the Th1-like immune responses. Here, we looked for a specific subset which would respond to CD26 upregulation by IL-12. Contrary to previously described results, under our culture conditions (1 microg/ml of PHA), IL-12 enhanced preferentially the CD8 cell proliferation. By using dual fluorescence analysis, IL-12-dependent CD26 expression was found in both CD4 and CD8 (previously CD26+ or CD26-) activated T cells and, moreover, the CD45RO percentage was unaffected. However, the density of CD45RO Ag (which was reported to coexpress with CD26) was impaired. These effects can be implicated in the biological functions of IL-12 and provide some clinical possibilities.

Interleukin-12 enhances CD26 expression and dipeptidyl peptidase IV function on human activated lymphocytes.

Research of a cellular pathway activated by IL-12 which may result in new therapeutical approaches for IL-12, led us to find an intriguing relationship between IL-12 and CD26/DPPIV ectopeptidase on activated T cells. Both the percentage and median fluorescence intensity (MFI) of CD26+ cells in the PHA-stimulated PBMC or lymphoblasts increased when IL-12 (optimum dose, 2 ng/ml) was present. Maximum CD26 expression was observed on day-2 cultures of lymphoblasts, the presence of IL-12 receptor probably being necessary for this upregulation. In addition, CD26 upregulation correlated with enhanced DPPIV function. Enzyme affinity and secretion of the soluble form of DPPIV were not affected by IL-12. Kinetic behaviours of Ag expression and enzymatic activity support a different CD26 regulation pathway by IL-12. These data suggest that the correlation found in vivo between the CD26 expression and Th1-like immune responses is due to this IL-12-dependent upregulation.