Serum pyroglutamyl aminopeptidase activity: a promising novel biomarker candidate for liver cirrhosis.

OBJECTIVE: As a reflect of tissue damage, serum aminopeptidases have been proposed as biomarkers of various diseases. In order to search new serologic markers for liver cirrhosis we conducted a preliminary study in which we analyzed a broad range of aminopeptidase activities in serum of controls and patients diagnosed with pancreatitis, hepatitis, and liver cirrhosis without distinction among the etiological type or the degree of severity of each condition. METHODS: Alanyl-, arginyl-, glutamyl-, cystinyl- pyroglutamyl-, and aspartyl-aminopeptidase activities were analyzed fluorometrically, using aminoacyl-ß-naphthylamides as substrates. In addition, various parameters, such as alanine transaminase, aspartate transaminase, alkaline phosphatase, total bilirubin, direct bilirubin, and gamma glutamyl transpeptidase were assayed as routine laboratory test for liver function. RESULTS: Compared with control group, alanyl- and arginyl-aminopeptidase activities increased nonspecifically in pancreatitis, hepatitis and liver cirrhosis, glutamyl- and cystinyl-aminopeptidases did not differ between groups and pyroglutamyl-aminopeptidase demonstrated that while pancreatitis and hepatitis did not differ between them and with controls, this activity decreased selectively in liver cirrhosis compared with all the rest of groups (p<0.001 vs. control and p<0.01 vs. pancreatitis and hepatitis). Aspartyl-aminopeptidase also decreased significantly (p<0.05) in liver cirrhosis compared with controls. Routine parameters for liver function test increased, as expected, in the three pathologies analyzed. CONCLUSIONS: Despite the heterogeneous composition of the three patient groups, the specific reduction of the levels of pyroglutamyl-aminopeptidase activity in serum of liver cirrhosis patients might be considered as a potential candidate to be included in a combination of markers for the diagnosis of this disease.

Asimetrías neuroquímicas en las alteraciones psiquiátricas / Neurochemical asymmetries in psychiatric disorders

La asimetría cerebral se podría definir como la existencia de una diferencia anatómica, funcional o bioquímica entre ambos hemisferios cerebrales. Más que estático se trata de un concepto dinámico en el que diversos factores endógenos y ambientales actúan como moduladores. Además, el desarrollo y el envejecimiento modifican la asimetría cerebral y algunas alteraciones neuropsiquiátricas ­como, por ejemplo, la esquizofrenia, la depresión, el autismo infantil o la enfermedad de Alzheimer­ se caracterizan en parte por un desequilibrio en determinadas asimetrías cerebrales. Sin embargo, no está claro si estos cambios son causa o consecuencia de tales alteraciones. Aunque la asimetría cerebral es un fenómeno ampliamente estudiado, su significado funcional y las bases neuroquímicas que subyacen a las asimetrías anatómicas y/o funcionales aún no han sido del todo dilucidados. En el presente trabajo se revisa la bibliografía más significativa referente a la asimetría cerebral en el ser humano, así como las alteraciones psiquiátricas más destacadas en las que se han descrito desequilibrios en la asimetría cerebral, incidiendo especialmente en los aspectos neuroquímicos de ésta

Brain asymmetry can be defined as an anatomical, functional or neurochemical difference between the two hemispheres. It is not a static but is rather a dynamic phenomenon in which both environmental and endogenous factors act as modulators. Moreover, aging modifies brain asymmetry, and an imbalance in specific asymmetries characterizes some brain disorders such as schizophrenia, depression, infantile autism and Alzheimer's disease. However, it is not clear whether these changes are a cause or a consequence of these disorders. Although this phenomenon has been extensively studied, its functional significance is not yet clear, and the neurochemical bases underlying anatomical or functional asymmetries in the brain are still poorly understood. In the present article the most important literature on human brain asymmetry, as well as the most significant psychiatric disorders in which imbalances in brain asymmetry have been described are reviewed, with special emphasis on its neurochemical component