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E Rocha

Publications and source records attributed to E Rocha.

At least 217 records · Page 12Linked to original sources
PubMedDate not supplied

Quantitative age-changes in endoplasmic reticulum and nucleus of cerebellar granule cells.

A stereological study was performed on cerebellar granule cells from rats 2 to 24 months of age (eight different ages, five animals per age group) to quantify age-related alterations in the rough endoplasmic reticulum (RER). The mean surface density and the mean total surface area of the nucleus, as well as the mean absolute volume of euchromatin per cell, were also estimated to examine whether or not these had quantitative relationships with the RER. The mean surface density and the mean total surface area of RER per cell changed significantly, attaining maximum values at 24 months of 1733 microm(2)/1000 microm(3) (0.06) and 64 microm(2) (0.03), respectively, (coefficients of variation in parentheses). The corresponding values at 2 months were 706 microm(2)/1000 microm(3) (0.20) and 26 microm(2) (0.24). The mean absolute volume of the euchromatin changed significantly, with a minimum value of 57 microm(3) (0.05) occurring at 21 months. We postulate that the increase in RER may be part of a mechanism that compensates for an age-related decrease in euchromatin. An increase in the RER network may improve intracellular transport of proteins, production of which is apparently diminished with aging. The increase may also compensate for the reported decrease in calcium buffer capacity of smooth endoplasmic reticulum.

Aging↗
PubMedDate not supplied

A stereological study on the nuclear volume of cerebellar granule cells in aging rats.

A morphometric study on age changes of rat cerebellar cortex (Crus I and Crus II) was carried out. The nuclear volume of the granule cells was estimated by means of two unbiased stereological methods: the nucleator, which enabled the estimation of the number-weighted mean volume (VN), and the point-sampled intercepts method, allowing the determination of the volume-weighted mean volume (VV). These parameters enabled the estimation of the coefficient of variation of nuclear volume in the number-weighted distribution [CV(VN)]. All parameters were determined in eight age groups (2, 6, 9, 12, 15, 18, 21, and 24 months--five animals per age) and the mean values of each age group were compared using one-way ANOVA with post hoc comparisons, and regression analysis. It was demonstrated for the first time, using unbiased techniques, that the nucleus of granule cells of the cerebellar cortex showed a significant decrease in its mean volumes (VV) with age, especially from 21 months onwards. Although CV(VN) was not correlated with age, it was also demonstrated that these cells bear a considerable nuclear size pleomorphy that was maintained throughout the age spectrum.

Aging↗
PubMedDate not supplied

Age-related changes in the volume of somata and organelles of cerebellar granule cells.

Because cerebellar granule cells are fixed post-mitotic cells, it is expected that they undergo age-related changes like other neurons. To examine this possibility, a stereological study on granule cells of rat neocerebellar cortex was performed for an age spectrum of 2 to 24 months using eight different age groups. The nucleator method, together with point and intersection counting, was used to obtain primary data; arithmetical calculations determined the secondary data. In the soma, the absolute surface area did not change significantly; the volume did, however, exhibit a significant negative linear trend with age. Excluding dense bodies, the absolute volumes of the cytoplasmic components did not vary significantly. The absolute volume of dense bodies displayed a significant positive linear trend with age. Significant positive correlations were detected between the somatic volume and the absolute volume of either mitochondria or ground substance. It was concluded that granule cells showed a fair degree of morphological stability through 18 months. However, the observed changes warn that accompanying physiological alterations may occur, with putative effects on motor coordination.

Aging↗
PubMedDate not supplied

Increased concentrations of tumor necrosis factor and interleukin-6 contribute to the hemostatic abnormalities in advanced liver disease.

Abnormal cytokine levels have been described in patients with chronic liver disease, but studies correlating cytokine homeostasis with abnormalities in coagulation and fibrinolysis are lacking. In order to establish a link between cytokines and the hemostatic changes the following parameters were determined in 44 patients with cirrhosis (alcoholic = 15, postnecrotic = 22, others = 7): TNF-alpha, IL-6, thrombin-antithrombin (TAT) complexes, prothrombin fragment 1 + 2 (F1 + 2) and t-PA by using enzyme-linked immunosorbent assays, and PAI-1, plasminogen and alpha 2-antiplasmin (alpha 2-AP) by using chromogenic substrates. All patients were at stages B and C of Child's classification when entering the study. Mean cytokine concentrations were significantly higher in cirrhotic patients as compared to age- and sex-matched controls (p < 0.009). There was a significant increase of TAT (p < 0.02) and F1 + 2 (p < 0.001) in the patients groups, suggesting a grade of intravascular coagulation. A hyperfibrinolytic state as demonstrated by an increase of t-PA and decrease of plasminogen and alpha 2-AP was also observed (p < 0.001). We could define a subgroup of patients with cytokine values higher than 20 pg/ml. Interestingly, in this group there was a significant increase of TAT (p < 0.04) and t-PA (p < 0.02) levels and a decrease of plasminogen and alpha 2-AP (p < 0.02) as compared to values observed in patients with cytokines lower than 20 pg/ml. We conclude that high levels of TNF-alpha and IL-6 may contribute to hyperfibrinolysis and intravascular coagulation in patients with liver cirrhosis, as assessed by the increase of TAT and t-PA levels and the reduction of plasminogen and alpha 2-AP.

Adult↗
PubMedDate not supplied

Calibration of trephine blade depth.

PURPOSE: To assess the accuracy and precision of the Barron radial vacuum trephine as an instrument for corneal lamellar dissection. METHODS: We describe a practical method to calibrate individual trephines prior to lamellar corneal procedures using the calibration microscope designed for diamond knives. RESULTS: We observed that one turn (360 degrees) of the trephine produced a mean blade displacement of 0.25 mm. However, individual trephines demonstrated a significant range of variability. CONCLUSION: For highly accurate trephination, it is useful to calibrate each individual trephine using the calibration microscope.

Calibration↗
PubMedDate not supplied

[Active immunotherapy in the treatment of haematological neoplasias].

The continuous search for therapeutic approaches that improve the conventional treatments of neoplasms, together with an improved understanding of the immune system, has led in recent years to the development of Immunotherapy. Basically, a distinction can be made between two forms of immunotherapy: passive immunotherapy, which consists in the transfer of antibodies or cells previously generated in vitro that are directed against the tumour, and active immunotherapy, which attempts to activate in vivo the immune system and induce it to elaborate a specific response against the tumor antibodies. Hematological neoplasms, specifically some B lymphomas, express in their membrane an immunoglobulin that is considered a specific antigen of the tumour, which is why these diseases have become the ideal target for immunotherapy treatments. There are many alternatives, ranging from protein vaccines, which have already shown clinical benefits, to those of the second generation, which make use of the new techniques of molecular biology to increase the efficacy of the vaccines and obtain their production in a quicker and less costly way, but with which there are not yet definitive clinical results.

Cancer Vaccines↗
PubMedDate not supplied

[A coronary disease registry. The fundamental basis for its control].

A register may be a list in which each item is individually identified, corresponding to uniform information about individual persons, collected in a systematic way, in order to serve predetermined purposes. However, disease registration, more than "notification", requires a permanent record for cases to be followed-up and statistical analysis to cover the frequency and survival. The register requires information to be up-to-date for individual and general disease surveillance. Nevertheless, on establishing a register, it is fundamental to define the purposes within the main areas of interest: identification of individuals; protection of the individual; surveillance; epidemiology (incidence; distribution, etiology, diagnosis, prognosis, prevention, analysis of benefits and risks); planning and evaluation of health care services; evaluation of treatment; research; education; development of methodology. The advantages of developing a coronary heart disease register are multiple: standardization of methods, accessibility to a database resulting from a multicentric study (inter-center cooperation and participation), definition of the problem magnitude, acquisition of a large range of concrete knowledge. The aims of registers determine the data to be recorded and the analysis. Before starting a Myocardial Infarction Register, or a register for another specified disease, we need to establish some questions: Who should be registered? What data should be recorded? How many cases? Where can they be established?, and when? The functioning of a register is based on the following steps: definition of criteria introduced; mode of detection; initial examination; follow-up (annual?) and computer system. The organization and maintenance of a disease register is not easy (in terms of time, money and personnel). Therefore, a successful register should be established when the previous conditions are fulfilled and if the required information (aims) cannot be obtained by other means. Even so, problems may occur in case-finding (sub-registration is the principal risk) and certainty of diagnosis or during the follow-up (data loss and patient drop-out). It is essential to maintain the efforts to guarantee the quality of the data and the surveillance of the patients that entered the study. Thus, a coronary heart disease (myocardial infarction) register may be fundamental for its control and, simultaneously, it forms an important part of the health information systems.

Coronary Disease↗
PubMedDate not supplied

Haemostatic changes in systemic inflammatory response syndrome during continuous renal replacement therapy.

BACKGROUND: Endothelial damage and hemostatic imbalance play an important role in the evolution of the Systemic Inflammatory Response Syndrome (SIRS) into the Multiple Organ Dysfunction Syndrome (MODS). In Acute Renal Failure associated with SIRS, different types of Continuous Renal Replacement Therapies (CRRT) may give non-renal benefits by modifying the levels of some factors related to those disturbances. METHODS: Forty patients with SIRS-associated ARF were randomised to receive either continuous venovenous hemofiltration (CVVH) or continuous venovenous hemodiafiltration (CVVHDF) for the first 24 h. Afterwards the CRRT method was reversed. The group treated with CVVH moved to CVVHDF and that treated with CVVHDF to CVVH for the next 24 h. Plasma levels of: von Willebrand Factor (vWF), thrombomodulin, plasminogen activity inhibitor type 1 (PAI-1: antigen and activity), tissue type plasminogen activator (t-PA: antigen), prothrombin fragment 1+2 (F1+2) and thrombin-antithrombin complexes (TAT) were measured previously to CRRT (base-line), and after 24 and 48 hours of therapy. Multivariate ANOVA was the statistical method used. RESULTS: In the MANOVA study a significant decrease in PAI-1 activity during the treatment procedure was observed (horizontality p <0.05). PAI-1 antigen showed a tendency to decrease although without statististical significance. There were no significantly different changes in the other factors analysed during either CRRT (parallelism p >0.05). At the base-line point, all the factors were higher than normal values in healthy adults. CONCLUSIONS: The present study suggests that CRRT, in patients with SIRS, may promote a decrease in PAI-1 and consequently, a better outcome. There were no differences between the CVVH and the CVVHDF methods regarding the factors analysed. The present data confirms that there is an important endothelial and hemostatic dysfunction in SIRS from the early phases.

Acute Kidney Injury↗
PubMedDate not supplied

[Von Willebrand factor as an intermediate between hemostasis and angiogenesis of tumor origin].

Cancer patients often show an imbalance condition between coagulation system and fibrinolysis which causes a prothrombotic state. Different molecular factors like von Willebrand factor (vWf), presenting higher plasmatic rates in these patients, play an important role in this situation. During active angiogenesis taking place in tumor growth, the vascular endothelial growth factor (VEGF) and the fibroblast growth factor (FGF-2) contribute to the proliferation and differentiation of endothelial tissue, the main vWf producer, promoting increased rates of vWf in the serum of neoplastic patients. Recently vWf's contribution to tumor cells and platelet adhesion has been described. In this process, the discovery of platelet, endothelial and tumor cell membrane integrins and their implication in cellular adhesion has represented a major step in demonstrating how blood clotting and platelet aggregation are mediated by tumor cell and platelet linkage. Migration properties acquired by tumor cells as a result of this binding have been also pointed out. Clinical trials show higher rates of plasmatic vWf in cancer patients the more advanced clinical and radiological stage they present (metastasic versus localized). Moreover, higher pre-surgical serum vWf rates in patients can be used to predict poorer survival after resection surgery. vWf high molecular weight multimers have been also related to a cleavage protease deficiency in the serum of the oncologic population. The promising results of antiaggregation/anticoagulation therapies in these patients permit us to envisage new therapeutic targets.

Hemostasis↗
PubMedDate not supplied

[Past, present and future of anti-idiotype vaccination].

Cancer vaccines are conceived as therapeutic tools, in contrast to the prophylactic vaccines used to fight against infectious diseases. Among the most potent therapeutic vaccines, anti-idiotype vaccination is directed against the tumor idiotype, the only well-characterized tumor antigen displayed in neoplastic B-cells. Anti-idiotype vaccines have demonstrated clinical benefit against follicular lymphoma and are currently being evaluated in two different phase III clinical trials. Additional emerging strategies, which include the use of dendritic cells and the production of vaccines via molecular means will surely allow us to draw important conclusions concerning the treatment of cancer patients.

Cancer Vaccines↗
PubMedDate not supplied

[Thrombotic, thrombocytopenic purpura: treatment with plasmapheresis, fresh plasma, platelet antiaggregants and corticoids].

A combination of antiplatelet agents, corticosteroids, plasmapheresis and fresh plasma achieved complete remission in a 35-yr old man diagnosed of thrombotic thrombocytopenic purpura who presented with hemolytic anemia, renal and neurologic damage. No symptoms 9 months after finishing treatment have been observed. Platelet and lactate dehydrogenase levels were the most useful analytical parameters in the follow-up.

Adrenal Cortex Hormones↗