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Biomedical subjects

M Castro

Publications and source records attributed to M Castro.

At least 181 records · Page 10Linked to original sources
PubMed1995

[Pseudosarcomatous tumor of the bladder].

Pseudosarcomatous tumour of the bladder is a benign neoforming process of uncommon occurrence, consisting in a fibroblastic proliferation originated in the vesical wall and the perivesical fat, with unknown etiology, that given its cellular pleomorphism and the infiltrative nature of the injury can be incorrectly diagnosed as a sarcoma. This paper presents one case of pseudosarcomatous tumour of the bladder in a 9 year-old child, with no history of local traumatism or previous surgery, consisting in a tumoration affecting the vesical wall associated with a significant perivesical fibrosis with extension towards the area of the iliac veasels. Microscopically, the injury shows proliferation of spindle cells, arranged in a myxoid stroma with a prominent vascular net. No cytologic atypia is demonstrated or increase in the number of mitosis. The immunohistochemical study shows features of myofibroblasts in the proliferant cell. A review of the literature is made on 40 cases of inflammatory pseudosarcoma, evaluating the clinical characteristics, morphologic findings and treatment involved, as well as the postoperative evolution of the patient.

Child↗
PubMed1995

Hepatic and blood lead levels in patients with chronic liver disease.

OBJECTIVE: To investigate the relationship between lead levels in the liver and blood, liver function indices and other biological variables in patients with liver disease. DESIGN: Prospective study. METHOD: The levels of lead in blood and hepatic tissue was measured in 92 patients with different liver diseases and in a control group (n = 100). Lead levels were analysed by electrothermic atomic absorption spectrophotometry. RESULTS: For controls, the mean lead level in blood was 175 +/- 87 micrograms/l. Blood lead levels were significantly linked with alcohol intake. They were raised in patients with alcoholic liver disease, including both those with cirrhosis (230 +/- 65 micrograms/l) and those with chronic non-cirrhotic liver disease (247 +/- 82 micrograms/l). The differences between these subgroups, the control group, and the patients with non-alcoholic liver disease were statistically significant. The mean hepatic lead level for patients was 2.30 +/- 1.40 micrograms/g dry weight (d.w.), and 2.15 +/- 1.71 micrograms/g d.w. for controls (not significant). Patients with alcoholic cirrhosis had higher hepatic lead levels than non-alcoholic patients (2.62 +/- 1.48 micrograms/g d.w. versus 2.07 +/- 1.14 micrograms/g d.w., respectively), although the difference was not statistically significant. There was no relationship between blood and hepatic lead levels (r = 0.27; not significant). Blood lead levels correlated with phosphorus (r = -0.36; P < 0.001), and alcohol intake (g/day; r = 0.32; P < 0.001). Blood and hepatic lead levels in patients with cirrhosis were similar for patients with Child-Pugh class A, B and C disease. CONCLUSIONS: Increased levels of lead were found in the blood of patients who consumed alcohol and those with alcoholic liver disease. Our data suggest that both blood and hepatic lead levels are not influenced by changes in liver function.

Adolescent↗
PubMed1995

[Lipid peroxidation, production of PGE2 and cellular mortality induced by UV in cultured human skin fibroblasts].

UV irradiation induces lipid peroxidation (LPO) and cell damage. The aim of the present work was the study of UVB radiation effects on cultured human skin fibroblasts, concerning LPO, prostaglandine E2 (PGE2) formation and cell viability. The cells were exposed to 50, 100, and 150 mJ/cm2 of UVB irradiation. Cellular TBARS and supernatant fluorescent substances were measured spectrofluorimetrically. PGE2 was measured using an immunoenzymatic method. Cell viability was evaluated by the MTT test. All determinations were done after a 2 h incubation period post-irradiation. TBARS were increased for all doses of irradiation (p < 0.001). Fluorescent substances differed from controls at 50 mJ/cm2 (p < 0.001). UVB at 100 and 150 mJ/cm2 decreased cellular viability (p < 0.001). An increase of PGE2 was observed with UVB at 150 mJ/cm2 (p < 0.001). These results confirm the occurrence of LPO and cytotoxicity after UV irradiation; on the other hand, this study showed the formation of PGE2 induced by UV light on cultured human skin fibroblasts. We propose a relationship between these phenomena.

Cell Death↗
PubMed1995

[Program of hypertransfusion and chelation with desferrioxamine in 10 patients with thalassemia major].

PURPOSE: Thalassaemia maior is an inherited severe anaemia due to abnormal haemoglobin synthesis. Hypertransfusion therapy is based on the reduction of ineffective erythropoiesis and improvement of the anaemia. To prevent iron overload, continuous chelation therapy was performed with desferrioxamine (DFO). The efficacy of such management in 10 thalassaemia maior patients followed-up for 11 years has been evaluated. PATIENTS AND METHODS: Packed red-cell transfusions were administered to maintain haemoglobin rates over 100 g/L; 40 mg/Kg DFO was given five days a week subcutaneously. The mean age at the start of such treatment was 9.3 years. Clinical problems due to iron overload were evaluated, such as heart function, growth and development, endocrinopathies, along with DFO toxicity and complications of transfusion (positive indirect antiglobulin test (IAT), hepatitis, HIV infection). RESULTS: Two patients died of heart haemosiderosis. The mean ferritin values at the end of the study were around 3.031 mg/mL. Heart dysfunction was seen in 2 cases; 2 patients had retarded growth, decreased IGF-1 being found in both; 3 cases had hypogonadotropic hypogonadism, and 2 had clinical hypoparathyroidism. Bilateral opacification of the eye lens appeared in one patients as a consequence of prolonged DFO therapy. Positive IAT was found in 3 cases, and one patient developed positive hepatitis C serology. CONCLUSIONS: Control of iron deposits by iron chelators can prevent the damages of iron overload. Adequate accomplishment of programmes may be difficult, especially in children.

Adolescent↗
PubMed1994

Vitronectin, fibronectin, and gp120 antibody enhance macrophage release of TNF-alpha in response to Pneumocystis carinii.

Alveolar macrophages (AMS) initiate inflammation during Pneumocystis carinii pneumonia by releasing cytokines including TNF-alpha. Recent studies suggest that macrophage responses to P. carinii are enhanced by serum opsonization, but the mechanisms of enhancement are not well defined. To determine whether macrophage release of TNF-alpha in response to P. carinii was augmented by immune opsonization, alveolar macrophages obtained from rabbits were cultured with P. carinii that had been opsonized with either nonimmune rabbit serum, immune serum generated against P. carinii, or an affinity-purified polyclonal Ab recognizing the major P. carinii surface Ag gp120. Each experiment also included organisms maintained in media alone (nonopsonized P. carinii). Opsonization of P. carinii with immune serum or gp120 Ab significantly enhanced macrophage TNF-alpha release. Interestingly, however, opsonization with nonimmune serum also increased TNF-alpha response to the organism. Because P. carinii is known to interact with the adhesive glycoproteins, vitronectin (VN) and fibronectin (FN), we hypothesized that they might also augment TNF-alpha release. Opsonization of P. carinii with VN or FN resulted in significant potentiation of macrophage TNF-alpha liberation. We further determined that VN and FN were present in increased quantities in the lower respiratory tract of patients with P. carinii pneumonia compared with normal volunteers. Additionally, VN and FN were demonstrated on the surface of freshly isolated P. carinii organisms by immunoblot analysis. Our study suggests that immune and nonimmune opsonins contribute to host defenses during P. carinii pneumonia by enhancing regional TNF-alpha release in response to the organism.

Animals↗
PubMed1994

Candida albicans stimulates arachidonic acid liberation from alveolar macrophages through alpha-mannan and beta-glucan cell wall components.

Candida albicans is an increasingly important fungal pathogen. Alveolar macrophages respond to fungal components such as zymosan by releasing arachidonic acid (AA) and AA metabolites. However, few studies hypothesized that macrophages respond to C. albicans by releasing AA and generating AA metabolites as a consequence of interaction of mannose and beta-glucan receptors with fungal cell wall components. [14C]AA-labeled rabbit alveolar macrophages released AA following stimulation with either live or heat-killed C. albicans. High-pressure liquid chromatography analysis revealed that 55% of the AA released was metabolized via cyclooxygenase and lipoxygenase pathways. The metabolites consisted of prostaglandin E2, prostaglandin F2 alpha, 6-ketoprostaglandin F1 alpha, thromboxane B2, and leukotrienes B4 and D4. We further examined the roles of alpha-mannan and beta-glucan components of C. albicans in mediating these alterations of eicosanoid metabolism. Prior work in our laboratory has shown that soluble alpha-mannan and beta-glucan inhibit macrophage mannose and beta-glucan receptors, respectively. Incubation of alveolar macrophages with soluble alpha-mannan derived from C. albicans (1 mg/ml) resulted in 49.8% +/- 2.6% inhibition of macrophage AA release during stimulation with intact C. albicans (P = 0.0001 versus control). Macrophage AA release in response to C. albicans was also inhibited to a significant but lesser degree by soluble beta-glucan (36.2% +/- 1.3%; P = 0.008 versus control). These results indicate that C. albicans stimulates macrophage AA metabolism and that these effects are partly mediated by alpha-mannan and beta-glucan constituents of the fungus.

Animals↗
PubMed1994

[Descriptive epidemiology of bladder cancer in the health area 8 in Madrid. Retrospective study on 315 patients].

The Madrid Health Care District No. 8 includes 19 town councils located in the South and West of the Autonomous Community. The actual population is 381,052 inhabitants with a floating population of 50,000 people. Currently, Mostoles Hospital is the Referral Health Centre of this district. Between 1983 and 1992, 315 patients received treatment for vesical cancer. Of them, 77% were primarily superficial and 23% infiltrant. 98% were transitional carcinomas. Patient's mean age was 65.9 years, with 83.5% men and 15.5% women. Incidence obtained was 14 x 10(5) inhabitants (23.5 men and 4.6 women). Smoking was the only risk factor statistically significant. Prevalence was 39.3 x 10(5). Actual mortality rate obtained for vesical cancer was 1.3 x 10(5). Comparison of our overall data with national and international statistics show extended consistence except for the mortality rate which was lower than the data consulted.

Aged↗
PubMed1994

[Transitional carcinomas of the urinary tract: synchronous and metachronous lesions].

OBJECTIVE: The urothelium is a pseudostratified cylindrical epithelium that lines the calices, renal pelvis, urethers, bladder, part of the urethra and part of the prostate ducts. Transitional cell carcinoma (TCC) is a malignant neoplasia that can appear in any site where urothelium is present, being the bladder the most frequently affected organ. We performed an analysis of our experience and conducted a literature-based metanalysis to evaluate the coexistence of tumoral lesions at different locations in the urinary tract. MATERIAL AND METHODS: Between 1983 and 1993, 397 patients with TCC lesions involving the upper urinary tract (UUT), bladder, urethra or prostate, were diagnosed and treated. Coexistence, either synchronic or metachronic, of several lesions in different sites of the urinary tract was considered as a multiple tumor. RESULTS: Overall, 440 tumors were diagnosed in 397 patients. A single lesion appeared in 360 patients, while 37 presented multiple locations with a total of 79 tumors. The lesions were located at the following levels: 17 renal, 21 uretheral, 372 vesical, 13 in the urethra and 17 in the prostate ducts. According to the location, the frequency of single lesions was: UUT 58%, bladder 91%, urethra 8% and prostate ducts 35%. Synchronic UUT and intravesical tract tumors develops in 1% and 4% of patients with bladder TCC, respectively. Two percent of vesical tumors showed metachronic relationship with UUT tumors and the same rate was seen for intravesical lesions. CONCLUSIONS: Urothelial UUT tumors have a typical nosologic entity with specific features. Their coexistence with vesical tumors is frequent. When tumors of the bladder occur after a UUT tumor the interval of highest incidence between diagnoses is 2-3 years, and there are no histological risk factors among them for prognosis. Transitional cell prostatic urethral tumors are most often secondary to histologically similar, poor prognosis, bladder tumors, and usually synchronic.

Adult↗
PubMed1994

[Flow index: a substitute for uroflow nomograms?].

One hundred and twenty-nine flowmetries from an equal number of male patients with urinary obstructive symptoms have been analyzed, and the data provided by Siroky's nomogram compared to the flow ratios. Flow ratio was considered compatible with obstruction if below 0.80, which in turn correlated to -2 DE in Siroky's nomogram. Agreement between both parameters was noted in 95% cases (p < 0.05). The use of a flow ratio as a substitute for Siroky's nomogram to evaluate urinary obstructive disease would be justified by the easiness of interpretation, since it avoids translation of maximum flow and mean flow data to a plot. Flowmetry should only be considered determinant with clearly obstructive values.

Adolescent↗
PubMed1994

[Extracorporeal lithotripsy for urolithiasis: retrospective study of 227 patients].

Presentation of a retrospective study in 227 lithiasic patients with indication for extracorporeal lithotrity (ESWL) as first line of therapy or as adjuvant treatment, referred to three lithotripter units over the last five years. There was a high percentage of personal history of lithiasis (55.5%), colic pain being the most frequent symptom (78%). Lithiasis largely affected one single renal unit, most often the left one (54.7%) and was solitary in 54.6% of cases. Calyceal and pyelic sites were the most common ones, the size of the stones ranging between 10-19 mm in 44.5% of cases. Overall results reflect a 78.5% success rate, with statistically significant lower occurrence of residual fragments in the right renal unit. There was greater success rates in ureteral calculi followed by calyceal ones and also in the smaller ones compared to those greater than 20 mm. Double-J ureteral catheterism was performed in 27% patients, with evidence of statistical significance between them and those uninstrumented in relation to occurrence of lithiasic trail. An 11% rate of significant complications requiring endourological handling due to obstruction in 7.5%, and open surgery in 3.5% due to complication or lack of resolution was detected.

Adolescent↗
PubMed1993

Impaired insulin release in aging rats: metabolic and ionic events.

We investigated the effect of aging on glucose uptake, glucose-induced O2 consumption, glucose-induced 45Ca movements, and calmodulin content to elucidate age-related impairment of glucose-induced insulin release in pancreatic islets of Wistar rats. Intact pancreatic islets from old (24-month-old) rats showed impaired glucose-induced insulin release; glucose uptake and O2 consumption were lower in old than in young (2-month-old) or adult (12-month-old) rats. Moreover, 45Ca uptake and calmodulin content were decreased in pancreatic islets from older rats, which explained the impairment in glucose-induced insulin release in aging. No major differences between the 3 age groups in glucose-induced 45Ca efflux in pancreatic islets were observed.

Aging↗
PubMed1993

Studies with etofibrate in the rat. Part II: A comparison of the effects of prolonged and acute administration on plasma lipids, liver enzymes and adipose tissue lipolysis.

To contribute to the understanding of the hypolipidemic action of etofibrate, which is the 1,2-ethandiol ester of clofibric acid and nicotinic acid, 300 mg of this drug/kg body weight or of the medium were administered daily by a stomach tube to normolipidemic rats. Some animals were decapitated at the 10th day of daily treatment (prolonged treatment), whereas others were studied at different times after one single administration (acute treatment). In animals on prolonged treatment etofibrate decreased plasma levels of cholesterol, triacylglycerols, free fatty acids (FFA) and glycerol, as well as the total and unesterified cholesterol concentrations, in liver microsomes. In these rats, etofibrate increased the activity of liver cytosolic glycerol-3-P dehydrogenase, whereas it decreased the activity of both microsomal HMG-CoA reductase and cholesterol 7 alpha-hydroxylase and did not affect acyl-CoA: cholesterol acyltransferase (ACAT). At 3, 5 and 7 h after acute treatment, etofibrate decreased plasma levels of triacylglycerols, glycerol and FFA, and this effect disappeared at 24 h, whereas plasma cholesterol did not change 3 h after etofibrate but decreased at 5 and 7 h and remained low after 24 h, and a similar change was found in the liver microsomes free cholesterol concentration. However, with the exception of a significant reduction in cytosolic glycerol-3-P dehydrogenase at 7 h and in ACAT at 5 h, acute etofibrate treatment did not affect the activity of the liver enzymes studied. At low concentrations (10(-5) M) in the incubation medium, etofibrate decreased the release of both FFA and glycerol by epididymal fat pad pieces incubated in vitro. These findings together with those previously reported by us in rats using a similar etofibrate treatment protocol [6] indicate that etofibrate decreases the availability of lipolytic products in the liver by acting on their release from adipose tissue and on their intrinsic hepatic metabolism. Consequently, this drug would decrease liver VLDL triacylglycerol synthesis and secretion, which together with facilitating the clearance of circulating triacylglycerols causes its hypotriglyceridemic effect. The hypocholesterolemic effect of etofibrate after acute treatment may be a secondary consequence of the reduced liver VLDL production caused by decreased adipose tissue lipolysis, but after prolonged treatment, this effect also seems to be influenced by the inhibition of HMG-CoA reductase activity which would reduce cholesterol synthesis.

Adipose Tissue↗
PubMed1993

Enteral nutrition with simultaneous gastric decompression in critically ill patients.

OBJECTIVE: Early enteral nutrition is an important adjunct in the care of critically ill patients. A double-lumen gastrostomy tube with a duodenal extension has been reported to enable early enteral feeding with simultaneous gastroduodenal decompression. We tested the ability of this device to achieve these goals in critically ill patients. DESIGN: Noncomparative, descriptive case series. SETTING: Surgical intensive care unit in a university hospital. PATIENTS: Fifteen consecutive critically ill patients, who, at the time of laparotomy, were assessed likely to need long-term nutritional support and gastric decompression, underwent tube placement. Mean age was 47 +/- 21 yrs. Mean Acute Physiology and Chronic Health Evaluation (APACHE II) and Therapeutic Intervention Scores were 15 +/- 7.3 (SD) and 29 +/- 10.2, respectively, and the mean Injury Severity Score of 11 trauma patients in the group was 27 +/- 7.4. INTERVENTIONS: Correct tube positioning was verified by radiograph or endoscopy. METHODS: Caloric and protein requirements, nutritional parameters, and problems encountered with the device were recorded. The correlation between the volume of feeding port input and suction port output was noted, and this correlation was considered significant if r2 was > or = .5. RESULTS: Only three (20%) of 15 patients reached full enteral nutritional support via the enteral route. None of these patients achieved this level of nutritional support within the first postoperative week. In 67% of the patients, large quantities of enteral feeding solution appeared in the gastroduodenal suction port effluent. When feeding port input was plotted against effluent volume, a correlation coefficient of > .71 (r2 = > or = .5) was found in 40% of the patients. Other complications included: a) excessive gastroduodenal drainage requiring fluid/electrolyte replacement in eight (53.3%) patients; and b) skin ulceration at the tube entrance site in seven (46.7%) patients. CONCLUSIONS: These data do not support the use of this device for early enteral feeding and simultaneous gastric decompression in critically ill patients.

Adolescent↗