Angiomixoma agresivo en un hombre: reporte de un caso / Aggressive angiomyxoma in a man: a case report

El Angiomixoma agresivo es una neoplasia de diferenciación incierta descrita por primera vez por Steeper y Rosai (1983), que tiene predilección por la región pélvica y perineal de mujeres entre la 3ra y la 6ta década de la vida, afectando con menor frecuencia al sexo masculino, con casos descritos de localización escrotal. En Venezuela hasta la fecha, no hay casos informados de este tumor en pacientes masculinos. Presentamos un caso de localización pélvica, confirmado mediante estudios de inmuno-histoquímica en un varón de 27 años de edad con una recidiva luego de 3 años de la exéresis inicial.

Aggressive angiomyxoma is a neoplasm of uncerta in differentiation first described by Steeper and Rosai (1983), which has a predilection for the pelvic and perineal region of females between the 3rd and 6th decade of life, affecting males less frequently, with reported cases of scrotal location. In Venezuela, to date, no cases were reported in male patients. A case of pelvic location we presented, confirmed by immunohistochemistry studies in a male of 27 years-old with a relapse after three years of the initial excision.

Meningiomas: hallazgos clínicos y morfológicos en una casuística de 24 años

Los meningiomas son neoplasias primarias frecuentes del sitema nervioso central, usualmente benignas y susceptibles de curación mediante cirugía. Se presentan los hallazgos clínicos y morfológicos en una casuística de 580 meningiomas diagnosticados durante el período 1980 a 2003. Estos tumores representaron el 16 por ciento de las neoplasias del sistema nervioso central y la gran mayoría fueron únicos (85 por ciento de los casos), con localización intracraneana preferente y manifestaciones clínicas relacionadas con el tamaño y localización del tumor. Afectaron con mayor frecuencia a mujeres (relación 2.4:1) y a pacientes con edades comprendidas entre los 30 a 59 años (67 por ciento de los casos). Según la clasificación histológicas de la Organización Mundial de la Salud, 80 por ciento de los meningiomas correspondieron al grado histológico I (beningnos), 17 por ciento al grado II (atípicos) y apenas 3 por ciento al grado (malignos). El subtipo histológico más frecuente fue la variante transicional. Resulta importante para el patólogo reconocer y clasificar adecuadamente a los meningiomas, puesto que de ello depende el tratamiento y pronóstico de este tipo frecuente de neoplasia

Meningiomas are frequent primary neoplasms of the central nervous system, usually benign and susceptible to healing through surgery. The clinical and morphological discoveries are presented in a study of 580 meningiomas diagnosed during the period 1980-2003. These tumors represented a 16% of the neoplasms of the central nervous system and most of them were unique (85% of the cases), with preferential intracranial localization and clinical manifestations related to the size and localization of the tumor. Women were affected more frequently (the rate female/male of 2.4:1) and patients with ages among 30 and 59 years (67% of the cases). According to the histologic classification of the World Health Organization, 80% of the meningiomas corresponded to histological grade I (benign), 17% to grade II (atypical) andonly 3% to grade III (malignant). The most frequent histological subtype was the transitional variant. It is important for the pathologist to recognize and classify adequately the meningiomas, since upon this depends the treatment and prognosis of this frequent kind of neoplasm

Tryptophan and serotonin in blood and platelets of depressed patients: Effect of an antidepressant treatment

Abstract: Platelets llave serotonin (5-HT) uptake and storage mechanisms similar to those from neurons. In addition, they represent nearly 99% of blood 5-HT concentration. For these characteristics, platelets are considered useful biomarkers of the serotonergic synaptic neurotransmission, particularly in psychiatric disturbances such as depression. However, most studies which have evaluated platelet 5-HT concentrations in depression have not shown similar findings. It has been suggested that changes in plasma tryptophan (TRP) concentrations might modify 5-HT concentration in the brain, as well as in platelets. Likewise, decreased plasma concentrations of TRP have been found in depressed patients, and the selective 5-HT reuptake inhibitors (SSRIs) induce changes in platelet 5-HT concentration. Considering the controversy surrounding platelet 5-HT concentrations in depressed patients, and the fact that blood 5-HT and TRP have not been studied in the Mexican population, we decided to study 5-HT and tryptophan concentrations in blood and platelets from depressed and control Mexican subjects to evaluate a possible correlation with the severity of depression. The effect of fluoxetine and citalopram treatment on blood and platelet 5-HT and TRP concentrations in depressed patients was also studied. Material and methods Depressed patients The patients of this study were carefully selected and evaluated. Scales based on semi-structured interviews were applied (MINI and SCID-II) by clinical investigators to reduce any possible bias in patient selection. The influence of the seasonal variability on the 5-HT or TRP blood concentrations was controlled by pairing depressed patients and healthy subjects according to age, gender and, in the case of women, menstrual cycle phase. Patients with a complete remission of depression symptoms (defined as a score not higher than 5 points in the Hamilton's scale, and lower than 7 points in Beck's scale) were asked for a blood sample to measure platelet and blood concentrations of 5-HT and TRP. The patients were weighted before the treatment and after their improvement. Control subjects The control group was integrated by 30 healthy subjects, 24 women and 6 men, with an average age of 32.3 ± 10.8 years. Participants were recruited from the overall Mexican population, interviewed by a psychiatrist, and evaluated with the structured interview MINI and the SCID-II, all these to discard any psychiatric diagnose. None of them had received any pharmacological treatment during the three weeks prior to the study. Control and depressed women were paired according to their menstrual cycle phase. All participants received a detailed explanation of the study, and those who voluntarily accepted the stipulations signed an informed consent document. Control and patient subjects were clinically examined and studied with routine laboratory tests (blood count, blood chemistry, urinalysis, and thyroid function test). Blood sample procedures 5-HT and TRP measurements in total blood preparation were carried out according to the method described by Anderson, and were quantified by high performance liquid chromatography (HPLC). Statistical analysis The differences were statistically determined through an analysis of variance (ANOVA), with the assistance of the SPSS 12.00 (Statistical Software by SPPS Inc.). Results Results from laboratory tests, such as blood count, blood chemistry, thyroid function (T3, T4 and TSH) and urinalysis were normal in depressed subjects, as well as in healthy volunteers. Platelet number, blood 5-HT concentration, platelet content of 5-HT, and blood tryptophan concentration showed no significant differences in depressed patients in comparison to control subjects. 5-HT values in blood and platelet were significantly lower than the initial concentrations in patients after antidepressant treatment. Discussion and conclusions Discrepancies between our study and those found in the literature can be explained with three different approaches: ethnical, physiological, and methodological, as is further discussed. The significant decrease produced by the antidepressant treatment in blood and platelet serotonin concentration may be a consequence of the action of SSRIs, due to a 5-HT diminished uptake by the platelet. Considering our results, we conclude that: Blood and platelet 5-HT concentrations were not different between depressed patients and healthy volunteers. Blood TRP concentrations were not different between depressed patients and healthy volunteers. SSRIs (fluoxetine or citalopram) used in the treatment of depressed patients induced a significant decrease in blood and platelet content of 5-HT, and had no effect in TRP concentrations. Based on these results, neither blood/platelet 5-HT nor blood tryptophan concentrations seem to be good biological markers of depressive patients status. However, 5-HT, but not tryp-tophan, might be a reference point for pharmacological treatment effect.

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Estado actual del trasplante cardíaco en Nuevo León: primeros 33 casos / Heart transplant in Nuevo Leon: the first 33 cases

Heart failure is one of the most important causes of death worldwide. Heart transplant is the last effective alternative when the medical and surgical treatments have failed in patients with end stage heart failure, giving them an 80% one year survival rate. Unfortunately, during the outcome, the heart transplant patients can develop complications such as graft rejection and opportunistic infections because of the use of immunosuppressive therapy. In the present article we report the experience with 33 heart transplant patients. Our program not only has successfully transplanted patients with advanced age but, for the first time in Latin America we have transplanted patients assisted with the ambulatory Thoratec TLC II system. Even with limited resources, we have managed the same complications than other heart transplant programs, our 82% one year survival rate is similar than reports in medical literature.

El sistema serotoninérgico en el paciente deprimido. Segunda parte

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Abstract: Nowadays there are increasing number of studies to support the crucial role of monoamines in depressive disorders. Among them are studies such as long-term treatment of antidepressants whose mechanism of action regulates monoamine metabolism, monoamine receptor density and post-mortem studies. An acute increase in monoamine concentration at the synaptic cleft might induce desensitization of brain auto- and hetero-receptors which explains the therapeutic antidepressive response. This has been proved by monoamine depletion studies in which an antidepressant effect or a patient relapse has been observed. Likewise, the antidepressive therapeutic response occurs earlier when auto-receptors are pharmacologically blocked at nervous and somatodendritic terminals. In the first part of this review, post-mortem studies related with the serotoninergic system were analyzed, as well as the usefulness of measuring serotonin, triptophan, and serotonin metabolite levels in different biological fluids of depressed patients. In this second part, alterations in platelet transporter and serotonin receptors are discussed as platelet is considered a neural serotoninergic model. Platelets are capable of storing and releasing serotonin in a similar manner as serotoninergic synaptosomes. Thus, platelets and serotoninergic synaptic terminals share biochemical and morphological properties. Serotonin transporter in platelets of depressed patients Due to the difficulty to obtain human brain samples and disagreements in the post-mortem studies, platelets have been suggested as a peripheral model to study neural serotonin uptake. The model is supported by the fact that platelet properties are similar to those of neuronal serotoninergic synaptic terminals. Serotonin studies in platelets have been useful in clinical aspects such as depressive disturbances. Radioligand studies in platelets from untreated depressed patients have shown a decrease in [H]-imipramine binding sites, compared to the binding in platelets from control subjects. Since that decrease has been consistently confirmed in studies on affective subjects, it has been proposed as a specific biomarker of depressed patients. Nevertheless, some researchers have not found similar results, and no explanation of the variability in the density of [H]-imipramine binding sites has been proposed. Serotonin receptor changes in depressed patients The hypothesis on receptor adaptative changes proposes that there is a depletion of monoaminergic neurotransmitters in depressed subjects which induces a compensatory regulation in the number and/or function of receptors. To explore this different techniques as the following have been developed: • Techniques to evaluate receptor density and affinity, including post-mortem radioligand binding to serotonin receptors in brain tissue and in platelets from depressed patients. • Techniques to evaluate receptor regulation and sensitivity by using neuroendocrine tests described below. Somatodendritic 5HT 1A autoreceptor dysfunction in depressive disorders Dysfunction of presynaptic somatodendritic 5HTja autoreceptors has been found in behavioral changes related to anxiety, depression and alcoholism. Neuroendocrine tests after the administration of 5-HT1a agonists have been used as an index of 5-HTta receptor function. It seems that azapirodecanediones increase plasmatic concentrations of prolactin, somatotropin, and adrenocortico-tropin; they also seem to decrease body temperature. In depressed patients, the hypothermia response, following presynaptic 5-HTta receptor stimulation, and the neuroendocrine response, following hypothalamus postsynaptic 5-HTta receptor stimulation, were both diminished. These findings suggest a desensitization or down-regulation of pre- and post-synaptic 5-HTja receptors in depressed patients. Platelet 5-HT 2A receptors in depressed patients Density and affinity Most radioligand studies have found an increase of platelet 5-HT2a receptors either in major depression patients or in attempted suicide patients. However, Rosel et al. studied platelets from depressed patients, finding an increment in the 5-HT2a platelet receptors affinity for [H]-ketanserin, but not in the receptors density. Functional capacity The evaluation of receptor function and sensitivity in platelets is performed after serotonin stimulation by using neuroendocrine tests and some other functional tests, such as platelet aggregation, morphological changes, quantification of intracellular calcium, and second messengers quantification. Despite being widely used, neuroendocrine tests are not completely reliable because they could be influenced by factors such as: stress on the hypothalamus-hypophysis axis, the lack of stereo-selective agonists and antagonists for different subtype serotonin receptors, and the effect of the drugs on other neurotransmitter systems. Other methodological aspects, such as: population heterogeneity, small samples, lack of variable control (i.e. age, sex, doses, diet, menstrual cycle), and placebo effects, are limitations to the neuroendocrine tests related to a single neurotransmitter system (serotonin). Results from platelet functional studies are contradictory as well. Platelet aggregation assays in depressed patients suggested a down-regulation of 5-HT2A receptors, compared to platelets from healthy subjects. However, some other studies have found no differences. Other platelet function responses mediated by 5-HT2A receptors, such as morphology changes, intracellular calcium, and phosphatidyl inositol hydrolysis, suggest a receptor up-regulation or hypersensitivity in depressed patients. Despite some disagreement among the results of platelet 5-HT2A receptor studies in depressed patients, most of them have reported an increase in 5-HT2A receptors density in these patients. However, suicidal behavior is clearly correlated to such an increase. Similar results have been observed in most post-mortem studies reporting an increase of 5-HT2A receptors in the prefrontal cortex. Protein synthesis and mRNA for 5-HT2A receptors are increased in prefrontal cortex and hippocampus in adolescent and adult suicide victims. These findings suggest that changes in the brain serotonergic system are related to depressive states and suicidal behavior. Human brain imaging techniques as well as molecular genetics studies may be additional tools to support the understanding of the neurobiology of depressive states, and their treatment.

El sistema serotoninérgico en el paciente deprimido. Primera parte

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Summary According to Spitzer et al., depression is a mood disorder characterized by sadness and accompanied by other symptoms such as irritability, anxiety, significant weight/appetite loss or gain, and feelings of guilt, worthlessness and hopelessness. Depressed patients are unable to accomplish everyday activities and may develop thoughts of death or suicide. Different neurotransmitters have been involved in the pathogenesis of depression; among them are noradrenaline, dopamine, gamma-aminobutyric acid, neuropeptides such as vasopressin and somatostatin, and endogenous opioids. However, serotonin (5-HT) has been the most studied and is suggested to play a central, but not exclusive, role in depression. This review analyzes studies which have involved serotonin as the vulnerable biochemical factor in depression. Postmortem studies Postmortem studies and 5-HT and 5-hydroxy-indolacetic acid quantification Many researchers have reported a decrease in 5-HT or its metabolite 5-hydroxy-indolacetic acid (5-HIAA) concentration in the brain stem of suicidal people. However, results are inconsistent since in other cerebral regions, such as the hypothalamus, cingulate and frontal cortex, no 5-HT or 5-HIAA concentrations have been found. Validity of postmortem results is limited by methodological issues as postmortem interval length, age of subjects, lack of assessment of nutritional status of suicide victims, drug abuse, medication, and differences in psychiatric diagnosis. Serotonin transporter and post-mortem studies Serotonin transporters are localized in cell presynaptic membranes in raphe and serotoninergic terminals projected to brain cortex. Radioligand studies have shown the occurrence of high affinity binding sites for [3H]-imipramine in human brain. Because of their localization in serotoninergic terminals and their likely participation in depression pathology, these binding sites have been suggested to be depression biomarkers. Early studies reported a decrease in [3H]-imipramine binding to prefrontal cortex in suicide victims with previous depression, as well as in occipital cortex and hippocampus in depressed patients who died of natural causes. These findings have been confirmed by other compound studies including [3H]-citalopram which has been identified as a more selective ligand for the serotonin transporter. A review by Purselle and Nemeroff of studies correlating depression, serotonin and suicide behavior found ambiguous data. These were likely due to methodological deficiencies such as a small sample size, deficient pairing criteria for control and treated groups, differences in radioligands, as well as disregarding comorbidity. These differences limit validation, comparison and interpretation of study results. Serotonin receptors and postmortem studies 5-HT 1A receptors. A decrease in 5-HT1A receptor density has been reported in suicidal depressed victims in the hippocampus, an important brain area for cognitive function. However, this receptor is highly sensitive to antidepressant treatment, which makes its determination rather ambiguous. On the other hand, no significant difference in brain cortex 5-HT1A receptors has been found between non-suicidal and suicidal subjects. 5-HT 1D receptors affinity has been reported to be decreased in depressed patients. 5-HT 2 receptors. Several researchers have observed an increase in postsynaptic 5-HT2 receptors in the frontal cortex and amygdala in suicidal depressed victims and depressed patients with no pharmacological treatment. An increase in 5-HT2A receptors has been reported in prefrontal cortex of suicidal adolescents, as well as higher levels of mRNA codifying for these receptors in prefrontal cortex and hippocampus. Tryptophan, serotonin, melatonin and 5-hydroxy-indolacetic acid in biological fluids Tryptophan in cerebrospinal fluid Findings on tryptophan levels in cerebrospinal fluid are controversial, for both normal and low levels have been found in depressed patients. Tryptophan in plasma Using the hypothesis of a decreased tryptophan availability to explain a low serotoninergic central activity in depressed patients does not stand due to different findings in levels of plasma-free tryptophan. Lower, normal and even higher levels of free tryptophan have been reported. Tryptophan availability might be influenced by neutral amino acids competing to cross the blood-brain barrier. Brain tryptophan levels might be modified if the free tryptophan/neutral amino acids ratio is reduced. It has been observed that depressed patients receiving antidepressants experienced a depressive relapse after receiving a low-tryptophan diet and returned to the remission state on returning to a regular food intake. Pharmacokinetic and pharmacodynamic factors might play a role in tryptophan availability in some depressed patients. Serotonin in cerebrospinal fluid Serotonin levels in cerebrospinal fluid are very low; this difficult carrying out studies in depressed patients. Serotonin in platelets Methodological and clinical criteria may explain the controversial results on platelet serotonin levels, which have found to be increased, decreased or unchanged. Serotonin in blood As platelet serotonin content includes 99% blood serotonin, serotonin blood levels might reflect brain serotonin content. After using fluvoxamine, a specific serotonin-reuptake inhibitor, the serotonin concentration in whole-blood preparation of patients was strongly reduced. After treatment with an unspecific mono-amine oxidase inhibitor, serotonin content was increased. Determination of 5-HT in whole blood preparation of patients treated with fluvoxamine might indicate a measure of drug compliance. Serotonin in plasma A significant decrease in plasma serotonin levels has been reported in depressed patients. Melatonin in plasma The melatonin synthesis use serotonine as building blocka. Melatonin have an important role in depression. It has been proposed that depressive states are a consequence of an inappropriate melatonin secretion. Therefore low plasmatic melatonin levels may be used as a biological marker for some types of depression. 5-HIAA in cerebrospinal fluid and plasma 5-HIAA, the major metabolite of 5-HT in plasma, has been suggested as a depression biomarker since cerebrospinal fluid 5-HIAA levels have found to be decreased in depressed patients. On the other hand, plasma 5-HIAA levels from untreated depressed patients were found to be significantly negatively correlated with severity of depression, despite the fact that the origin of plasma 5-HIAA is largely peripheral. 5-HIAA in urine Studies concerning urine 5-HIAA levels have been inconclusive in depression, likely due to the 5-HIAA urinary level variations from one day to another. Furthermore, the major fraction of 5-HIAA in blood as an intestinal precedence, therefore, blood 5-HIAA levels may not correlate with cerebral levels. Conclusion The serotoninergic system seems to be the neurotransmission system whose variations may explain every clinical manifestation in depressed patients. However, interpretation of measurements of tryptophan, serotonin, and its metabolites in biological fluids as an index of brain serotonin availability and function is difficult to achieve, mainly due to methodological discrepancies.

La plaqueta como marcador biológico periférico de la función serotoninérgica neuronal

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Abstract: Among all neurotransmitters, serotonin or 5-hydroxi-triptamine (5-HT) is probably the most studied in neuropsychopharmacology. Interest in this neurotransmitter is due to cumulative evidences showing that neuronal serotonergic systems are altered in depressed patients, as well as in several behavior dysfunctions like aggressiveness, impulsiveness, and suicide attempts, among others. Also, specific agonists and antagonists have been synthesized, which has enabled the characterization of the serotonergic receptor subtypes. Furthermore, highly selective inhibitors ofserotonin uptake have been developed, and these are capable of working in the synaptic terminals, as well as in other cell systems, such as platelets. This has allowed for the understanding and characterization of the action mechanisms of diverse psychoactive drugs interacting with the serotonergic system. Platelets have been proposed as an outlying model resembling that of serotonergic neurons due to the similarities they present in the uptake, storage, and serotonin release mechanisms, as well as the presence in platelet membranes of serotonin 5-HT2A receptors. The platelets have a serotonergic system consisting of four main components: 1. an uptake mechanism, 2. intracellular storage organelles, 3. serotonergic receptors in the plasmatic membrane, and 4. a mitochondrial enzyme, the monoamine oxidase (MAO), which metabolizes serotonin. All these elements show physiologic similarities with the neuronal serotonergic system. Serotonergic similarities in neurons and platelets In the Central Nervous System (SNC) serotonin acts mainly as an inhibitory neurotransmitter. The precursor for its synthesis is the aminoacid tryptophan. This is taken from the blood to the cerebral interstice, where it is taken up by the nervous terminals and converted into 5-hidroxytryptophan (5-HTP) by the enzyme tryptophan hydroxilase. The conversion to 5-HTP is a key regulatory step in serotonin synthesis, and is converted quickly in 5-HT by the action of the aromatic L-acid descarboxilase. However, platelets do not synthesize 5-HT, since they do not possess tryptophan hydroxilase. Thus they only display uptake, storage, and serotonin release functions. Serotonin actions The neurotransmitter functions of neuronal serotonin, generally inhibitory, depend on the serotonergic receptor characteristics it interacts with. Its action mechanism can be mediated through second messengers (metabotrophic receptors) or through a direct action over ionic channels (ionotrophic receptors). In the platelets, serotonin is stored in a slow replacement depot, where it can be released from by exocythotic mechanisms. Serotonin participates in the platelet activation that allows for their aggregation to each other for blood clotting process. Serotonin uptake To stop the serotonin neurotransmitter function, neuronal serotonin is taken up from the synaptic cleft by transporter proteins. The serotonin neuronal uptake is impelled by a proton gradient that requires ATP. The 5-HT uptake can follow two paths: the 5-HT can be metabolized by the MAO into 5-hydroxy-indolacetic acid, or it can be reintroduced into release vesicles in order to be reutilized as a neurotransmitter. The serotonin uptake by platelets occurs either by passive diffusion or by active transport mechanisms. Under physiological conditions, the active uptake mechanism is the most effective. This uptake is mediated by proteins similar to the ones required for the neuronal serotonin uptake in the brain. It requires energy and the presence of Na+ and Cl-. The platelet uptake system has a relatively high affinity (Kd) for 5-HT, being similar in magnitude from platelets to neurons. The platelet storage of 5-HT is located mainly in the dense bodies and in the storage granules. Serotonin transporters in platelets and synaptic terminals The main form of ending a serotonergic transmission pulse is by taking up 5-HT molecules from the synaptic cleft directed to reduce the serotonin concentration, which then stops the serotonergic neurotransmission. The uptake process involves a molecular recognition of 5-HT by the transporter, its binding, and passing through the membrane to be released within the cellular. Serotonin molecules bound to its transporter protein cross through the membrane using Na+ as a driving force. The return ofthe transporter to its original position requires K+ as the driving force to step this protein toward its original position. When a selective serotonin reuptake inhibitor is administered, the 5-HT concentration increases in the synaptic cleft, which enhances serotonin neurotransmission. This increase induces a down regulation cascade of both: serotonin autoreceptors (presynaptic) and postsynaptic receptors, that may finally reestablish the resting state of the neuron. It has been confirmed that the protein for neuronal as well as platelet serotonin uptake transport are synthesized by the same gene. Experimental evidence has shown that the platelet transporter presents the same functional and pharmacological characteristics than the neuronal transporter. Serotonergicreceptors Seven types of pre and post synaptic serotonin receptors, which have also several subtypes, have been characterized. Pre and post synaptic 5-HT 1 receptors . The 5-HT1 receptors are involved in both pre and post synaptic serotonergic neurotransmission. The presynaptic 5-HT1A receptors are autoreceptors. Due to their localization in the cellular body and in the dendrites, they have been named somatodendritic autoreceptors, which control the serotonin release. The postsynaptic receptors may play a role in hypothalamic thermoregulation. The presynaptic 5-HT1D receptors are autoreceptors that perform a regulation by blocking the 5-HT release. These receptors are not synthesized in platelets. Postsynaptic 5-HT 2 receptors . The 5-HT2 receptor subtypes are 5-HT2A,BandC. When postsynaptic 5-HT2Areceptors are bound to serotonin, they drive the transduction of neuronal impulses through the production of second messengers within the postsynaptic neuron. These second messengers induce the synthesis of intracellular proteins denominated transcription factors, which may regulate the expression of several neuronal genes. Platelet 5-HT2A receptors correspond to the neuronal 5-HT2A metabothropic receptors and induce alterations in platelet density and affinity. 5-HT 3 receptors . These receptors were originally described in the periphery, specifically as part of the enteric nervous system. In the CNS 5-HT3 receptors are densely present in the solitary tract nucleus and in the area postrema. These receptors are the onlymonoaminergic receptors consistingofionic channels operated by aminergic neurotransmitters. The stimulation of 5-HT3 receptors is responsible of several secondary effects of the selective inhibitors of serotonin reuptake (SISR). These effects are not mediated only in the CNS, but also in sites outside the brain, such as the intestine, which possess this type of receptors also. These receptors are not located in the platelets. 5HT 4-7 serotonergic receptors . These receptors are distributed throughout the body, where they stimulate the alimentary tract secretions and facilitate peristaltic reflexes. Their localization in serotonergic areas in the brain and platelets has not been established. Notwhithstanding their limitations, the characteristics reviewed support the conclusion that platelets can be used as partial models to study the neuronal serotonin 5-HT2 binding and uptake functions. As Alfred Pletscher stated: "although the incomplete of the pattern demands care in its application, they could have the advantage of the relative simplicity".

Prevalencia de sucesos violentos y de trastorno por estrés postraumático en la población mexicana / Prevalence of violent events and post-traumatic stress disorder in the Mexican population

OBJETIVO: Reportar el índice de exposición a diferentes sucesos violentos, los correlatos demográficos, la prevalencia de trastorno por estrés postraumático y el impacto sobre la calidad de vida. MATERIAL Y MÉTODOS: La Encuesta Nacional de Epidemiología Psiquiátrica es representativa de la población mexicana urbana de 18 a 65 años de edad. Se realizó entre 2001 y 2002, con el instrumento diagnóstico de la versión computarizada de la Entrevista Internacional Compuesta de Diagnóstico (CIDI-15, por sus siglas en inglés). Los análisis toman en cuenta el diseño complejo de la muestra aleatoria, multietápica y estratificada. Se utilizaron el Método Kaplan-Meir y regresiones logísticas. RESULTADOS: El 68 por ciento de la población ha estado expuesta al menos a un suceso estresante en su vida. La exposición varía por sexo (violación, acoso y abuso sexual son más frecuentes en mujeres; los accidentes y robos, entre los hombres) y por edad (niños, adolescentes, mujeres adultas jóvenes y personas de la tercera edad). El 2.3 por ciento de las mujeres y 0.49 por ciento de los hombres presentaron un trastorno de estrés postraumático. La violación, el acoso, el secuestro y el abuso sexual son los sucesos con mayor manifestación de trastornos por estrés postraumático. CONCLUSIONES: Los resultados refuerzan la necesidad de ampliar la cobertura de tratamiento para atender las secuelas de la violencia, considerando las importantes variaciones de género y estadios de desarrollo.

Carcinoma transicional de la vejiga urinaria metastásico al sistema nervioso central: reporte de un caso / Transitional carcinoma of urinary bladder metastasic to the central nervous system: case report

Los tumores metastásicos al sistema nervioso central se presentan con una frecuencia del 20 por ciento al 25 por ciento. El carcinoma transicional de la vejiga urinaria constituye del 4 por ciento al 8 por ciento de todos los carcinomas y, la metástasis se presentan en orden de frecuencia en ganglios linfáticos, pulmones, hígado y hueso; en el sistema nervioso central es muy raro. Presentamos el caso de un paciente masculino de 49 años con carcinoma de células transicionales de vejiga, quién tres años después fue intervenido por dos metástasis intracerebrales corroboradas por estudio histológico e inmunohistoquímico. La metástasis al sistema nervioso central del carcinoma transicional de vejiga ocurren entre el 0.4 por ciento al 12 por ciento y, la mayoría se presentan cuando existe diseminación sistémica. Algunos investigadores han encontrado un aumento en la frecuencia de estas metástasis después del tratamiento del tumor primariocon quimioterapia

Miopatía por depósito de lípidos: una entidad válida en el diagnóstico del síndrome hipotónico correlación clínico-morfológica / Lipid storage myopathy:a valid entity in the diagnostic of hypotonic syndrome: clinical-morphological correlation

Las miopatías por depósito de lípidos son la expresión fundamental de los trastornos del metabolismo lipídico muscular. En el presente estudio exponemos cuatro casos de la entidad y señalamos las características clínicas, histopatológicas y bioquímicas que están presentes en los defectos genéticos del metabolismo de los ácidos grasos del músculo esquelético. En tres casos los hallazgos fueron compatibles con el diagnóstico de la entidad por déficit de carnitina y en uno por déficit de flavoproteínas. Tres correspondieron a pacientes del sexo femenino. Concluimos que con una correlación sistemática de los datos clínicos y paraclínicos, así como también del estudio morfológico, se puede inferir la posible etiología de estas miopatías, cuyo diagnóstico definitivo es por medio del análisis bioquímico

Atrofia muscular neurogénica en miopatía nemalínica: ¿fenómeno primario o secundario? a propósito de un caso / Neurogenic muscular atrophy in nemaline myopathy: ¿primary or secondary phenomenon? case report

La miopatía nemalínica es una miopatía congénita estructural que cursa con debilidad muscular generalmente no progresiva y se caracteriza por la presencia de los llamados "bastones" o "nemalines" en las fibras musculares. Se presenta el estudio anatomoclínico de una forma neonatal severa de la enfermedad en la cual encontramos, además, atrofia muscular neurogénica y escasas motoneuronas de la médula espinal con degeneración simple, sin otra evidencia de denervación. Se revisan otros casos similares descritos en la literatura y se plantea la posibilidad de un trastorno de la inervación, o bien, que el daño muscular por nemalines ocasione una lesión neurogénica por vía retrógrada

Macroangiopatía mediada por complejos inmunes en pacientes diabéticos tipo 2 con neuropatía proximal / Inmune complex mediated icroangiopathy in the type 2 diabetics with proximal neurophaty

Se estima que aproximadamente el 40 por ciento de los diabéticos presenta algún tipo de alteración neuropática en el momento del diagnóstico; de ellos la mitad evoluciona a complicaciones incapacitantes, entre ellas: la amiotrofia. Como mecanismo fisiopatológico se plantea una teoría inmune que puede ser identificada por estudios histopatológicos e inmunohistoquímicos de la vasa nervorum en las lesiones neurales de esos estudios descriptivo transversal, de 15 diabeticos tipo 2, con debilidad proximal progresiva en miembros inferiores, asimétrica, con o sin dolor neuropático, con evaluación no mayor de un año evaluados en el Hospital General del Oeste. Se realizó laboratorio, electromiografía, biopsia del nervio Sural del músculo cuadriceps. Los estudios histopatológicos del nervio evidenciaron que: 15 pacientes tenían algún grado de desmielización segmentaria, con vasculitis en 4 casos y perivasculitis en 12. En el músculo, se encontró atrofia no sistematizada en 13 pacientes. En el estudio inmunohistoquímico de nervio se encontró IgG positiva en todos los casos, con CD45RO positivo en todos los pacientes evaluados, CD68 positiva en 14 y la mieloperoxidasa en 7. También se documentó la presencia de vasculitis y/o perivasculitis en la biopsia del nervio sural y músculo cuadriceps. Se demostró la importancia del compromiso inmunológico en las lesiones del nervio periférico

Distrofina como herramienta diagnóstica / Dystrophin how implement diagnóstic

Las distrofias musculares constituyen un amplio grupo de enfermedades con una forma de presentación y un curso clínico variable; entre ellas, las distrofinopatías, con herencia ligada al cromosoma X como la distrofia muscular tipo Duchenne y tipo Becker son entidades poco frecuentes. Se estudiaron las biopsias de 5 pacientes pedíatricos con diagnóstico de distrofia muscular, con microscopia convencional, histoquímica enzimática e inmunorreacciones para distrofina. En tres casos se diagnosticó distrofia muscular tipo Duchenne y en dos casos, distrofia muscular tipo Becker. A través de esta presentación se pone en relieve la importancia de la realización de inmunorreacción para distrofina en el diagnóstico de estas entidades, del estudio del grupo familiar, de proporcionar consejo genético y de diferenciarlas de otras miopatías

Neurocitoma central a propósito de un caso diagnósticado por biopsia estereotáxica / Central neurocytoma a purpose of one case diagnostic for biopsy stereotaxic

El neurocitoma central (NC) es un tumor neuronal frecuentemente intraventricular, que generalmente afecta adultos jóvenes y suele cursar con una evolución clínica favorable. Varios cortes de un bloque celular, obtenido mediante biopsia estereotáxica de una mujer de 29 años con un tumor en el septum pellucidum, fueron evaluados por microscopía convencional e inmunocitoquímica. El tumor estuvo compuesto por células redondas pequeñas dispuestas en una matriz fibrilar y separadas por capilares ramificados, con presencia de pseudorosetas perivasculares. La sinaptofisina y proteína ácida glial fibrilar fueron positivas. Los NC pueden ser indistinguibles de los oligodendrogliomas y ependimomas, por lo cual es importante reconocerlos, dada las implicaciones pronósticas y terapéuticas. El conocimiento de las características clínicas y citomorfológicas del NC es fundamental en la evaluación de tumores intraventriculares de células redondas pequeñas, especialmente cuando se trata de biopsias estereotáxicas

Metaplasia transicional de la trompa uterina: una entidad poco conocida: presentación de un caso y revisión de la literatura / Transitional cell metaplasia of the fallopian tuve: one entity prominent limited: one case presentation and literature revision

En el aparato genital femenino son frecuentes los cambios metaplásticos del epitelio de revestimiento, siendo su patogénesis un hecho aún no aclarado. La metaplasia transicional es infrecuente y poco documentada en la literatura. Presentamos un caso de metaplasia transicional de la trompa de falopio; una lesión poco frecuente y rara vez informada. También llamamos la atención sobre la posibilidad de que lesiones metaplásicas del aparato genital femenino, puedan ser confundidas con lesiones neoplásicas; además de referirnos a las controversias existentes con relación a la histogénesis del carcinoma de células transicionales

Forma pseudotumoral de esclerosis multiple / Pseudotumoral of multiple sclerosis

La esclerosis múltiple (EM) es una enfermedad desmielinizante que puede presentarse clínica y radiologicamente como una lesión ocupante de espacio y ser confundida con una neoplasia. Nosotros pesentamos los hallazgos clínico - patológicos de dos casos de esta forma de presentación poco frecuente de esclerosis múltiple, uno ubicado en la médula espinal y otro en el bulbo raquídeo, ambas confirmadas morfológicamente. El objetivo de este trabajo es resaltar la importancia que para el clínico y el patólogo tienen el reconocer estas lesiones, ya que para una interpretación errónea podría conducir a tratamientos inadecuados, que afectarían el curso de la enfermedad

Enfermedad de lafora: una forma poco frecuente de epilepsia mioclónica: aspectos clínicos, histológicos, inmunohistoquímicos y ultraestructurales de un caso: revisión de la literatura / Lafora's disease: an form little frequent of myclonus epilepsies: aspect clinic histological inmunohistochemical and ultrastructural: revision of a case and of the literature

Los cuerpos de poliglucosán (CPG), se encuentran en diversas entidades patológicas e incluso en condiciones normales. Su hallazgo en biopsia, cerebrales de pacientes con epilepsia mioclónica progresiva es diagnóstico de enfermedad de Lafora, siendo también encontrados en hígado, músculo esquelético, músculo cardíaco y piel. Presentamos los hallazgos clínicos, gistoquímicos, inmunohistoquímicos y ultraestructurales de la biopsia cerebral de un paciente masculino de 18 años de edad, en el que clínicamente se sospechó la enfermedad

Enfermedad de Creutzfeldt-Jakob en Venezuela: informe de 10 casos y revisión de la literatura / The Creutzfeldt-Jakob disease in Venezuela: report of 10 cases and revition of the literature

La enfermedad de Creutzfeldt-Jakob (ECJ) es una encefalopatía espongiforme transmisible infrecuente y de amplia distribución mundial. Su incidencia en Venezuela es desconocida y sólo 5 casos previos han sido publicados. Se presentan en este informe 10 casos estudiados en los últimos 27 años. La confirmación del diagnóstico fue realizada mediante el estudio histológico y estructural de muestras del cerebro y/o cerebelo, obtenidas por biopsia en 3 casos y por autopsia en 7. El promedio de edad fue de 60,1 años. El intervalo entre el inicio de los síntomas y muerte fue de 4,5 meses. Todos los pacientes presentaron un síndrome demencial rápidamente progresivo asociado a signos piramidales y extrapiramidales, mioclonos y cambios en el electroencefalograma. El examen histológico reveló en todos los casos degeneración espongiosa, astrogliosis y pérdida neuronal en la sustancia gris de la corteza cerebral, núcleos basales y cerebelo. Desde el punto de vista estructural, las áreas afectadas en 4 casos estudiados mostraron vacuolización extensa del neurópilo, degeneración neuronal y prolongaciones astrogliales con numerosos filamentos intermedios. Ningún caso tenía antecedente familiar ni causa iatrogénica probable de la enfermedad. Se plantea la posibilidad de un subregistro de la ECJ en Venezuela y la importancia epidemiológica que tiene el conocimiento de esta entidad clínico-patológica en el diagnóstico diferencial de los diferentes tipos de trastornos demenciales

Neurotuberculosis: lesiones expansivas del sistema nervioso central / Neurotuberculosis: expansives injuries of the central nervous system

La tuberculosis (TBC) del sistema nervioso central (SNC), rara vez se manifiesta como una lesión ocupante del espacio (LOE), siendo los tuberculomas más frecuentes que los abscesos tuberculosos. Presentamos los hallazgos clínicos, imagenológicos e histopatológicos de tres tuberculomas y un absceso tuberculoso. En todos los casos se realizaron coloraciones para bacterias, hongos y bacilos ácido alcohol resistentes (BAAR). Todos los pacientes presentaron manifestaciones clínicas e imagenológicas de LOE. El diagnóstico de neurotuberculosis fue establecido por estudios histopatológicos. Las LOE por TBC en el SNC pueden presentar problemas en el diagnóstico diferencial, por lo que es necesario correlacionar la información clínica y los hallazgos anatomopatológicos, para establecer un diagnóstico y tratamiento temprano