Search PubMed⌕ Search

Biomedical subjects

M Costa

Publications and source records attributed to M Costa.

At least 19 recordsLinked to original sources
PubMed2006

Impact of intraoperative ultrasonography in laparoscopic liver surgery.

BACKGROUND: Laparoscopic surgery has gained growing acceptance, but this does not hold for laparoscopic surgery of the liver. This mainly includes diagnostic procedures, interstitial therapies, and treatment of liver cysts. However, the authors believe there is room for a laparoscopic approach to the liver in selected cases. METHODS: A prospective study of laparoscopic liver resections was undertaken with patients who had preoperative diagnoses of benign lesion and hepatocellular carcinoma with compensated cirrhosis. The inclusion criteria required that hepatic involvement be limited and located in the left or peripheral right segments (segments 2-6), and that the tumor be 5 cm or smaller. The location of the tumor and its transection margin were defined by laparoscopic ultrasound (LUS). RESULTS: From December 1996, 17 (5%) of 313 liver resections were included in the study. There were 5 benign lesions and 12 hepatocellular carcinomas in cirrhotic patients. The mean age of the study patients was 59 years (range, 29-79 years). The LUS evaluation identified the presence of new hepatocellular carcinoma nodules in two patients (17%). The resections included 1 bisegmentectomy, 8 segmentectomies, 3 subsegmentectomies, and 3 nonanatomic resections. The mean operative time, including laparoscopic ultrasonography, was 156 +/- 50 min (median, 150 min; range, 60-250 min), and the perioperative blood loss was 190 +/- 97 ml. There was no mortality. Conversion to laparotomy was necessary for two patients. Postoperative complications were experienced by 3 of 15 patients, all of them cirrhotics. One of the patients had a wall hematoma, and the remaining two patients had bleeding from a trocar access requiring a laparoscopic reexploration. The mean hospital stay for the whole series was 6.9 +/- 4.9 days (median, 6 days; range, 2-25 days) and 5.6 +/-1.4 days (median, 6 days; range, 2-8 days) for the 15 laparoscopic patients. CONCLUSION: Laparoscopic treatment should be considered for selected patients with benign and malignant lesions in the left lobe or frontal segments of the liver. Evaluation by LUS is indispensable to guarantee precise determination of the segmental tumor location and the relationship of the tumor to adjacent vascular or biliary structures, excluding adjacent or adjunctive new lesions. The evolution of laparoscopic hepatectomies probably will depend on the development of new techniques and instrumentations.

Adult↗
PubMed2006

Effect of glatiramer acetate (Copaxone) on the immunophenotypic and cytokine profile and BDNF production in multiple sclerosis: a longitudinal study.

We assessed the effect of glatiramer acetate (GA) on the immunophenotypic and cytokine profile and the BDNF production by peripheral blood mononuclear cells, and their association with the clinical response in 19 naïve-treated MS patients prospectively followed-up after GA therapy. Two patients withdrew the therapy. After a median follow-up of 21 months, twelve were considered responders and five as non-responders. Non-responder patients had significant longer disease duration and a higher EDSS score at baseline. In the responder group, a significant decrease in the percentage of INF-gamma producing total lymphocytes, CD4+ and CD8+ T cells, and reduced percentage of IL-2 producing CD4+ and CD8+ T cells were observed at 12, 18 and 24 months. These changes were associated with a significant increase in the percentage of CD3+, CD4+ and CD4(+) CD45RA(+) T cells, and BDNF production from month 6 that remained significant throughout the study. We did not observe significant changes in the nonresponder group for any of the parameters studied. Our data suggest that GA treatment induces a downmodulation of proinflammatory cytokines associated with the regulation of the peripheral T cell compartment and with increased production of BDNF that might be related to the clinical response.

Adjuvants, Immunologic↗
PubMed2006

Laparoscopic ultrasound-guided resection of gastric submucosal tumors.

BACKGROUND: The laparoscopic resection of gastric stromal tumors is being performed with increased frequency. Wedge resection of anterior wall lesions is generally performed. The treatment of posterior wall lesions is still controversial. METHODS: We report three cases of gastric submucosal tumors treated by a laparoscopic wedge resection of the stomach. All lesions were localized anterior gastric wall by intraoperative ultrasound on the. In the first patient the resection was performed with an endoscopic stapler; in the other patients, ultrasonic coagulation in association with an intracorporeal suture has been used. RESULTS: All patients were successfully treated laparoscopically; there were no conversions to open surgery. In all cases the operative course was uneventful. The postoperative hospital stay ranged from 6 to 8 days. CONCLUSIONS: The results suggest that laparoscopic surgery is an adequate strategy for gastric submucosal neoplasms including gastrointestinal stromal tumors (GIST). Intraoperative ultrasound is very useful in the selection of the technical approach with or without the endoscopic stapler.

Adult↗
PubMed2006

Fast detection of arbitrarily shaped disease clusters.

Disease cluster detection and evaluation have commonly used spatial statistics methods that scan the map with a fixed circular window to locate candidate clusters. Recently, there has been interest in searching for clusters with arbitrary shape. The circular scan test retains high power of detecting a cluster, but does not necessarily identify the exact regions contained in a non-circular cluster particularly well. We propose, implement and evaluate a new procedure that is fast and produces clusters estimates of arbitrary shape in a rich class of possible cluster candidates. We showed that our methods contain the so-called upper level set method as a particular case. We present a power study of our method and, among other results, the main conclusion is that the likelihood-based arbitrarily shaped scan method is not appropriate to find a cluster estimate. When the parameter space includes the set of all possible spatial clusters in a map, a large and discrete parameter space, maximum likely cluster estimates tend to overestimate the true cluster by a large extent. This calls for a new approach different from the maximum likelihood method for this important public health problem.

Brazil↗
PubMed2006

Factors predicting intermediate endpoints of cervical cancer and exposure to human papillomavirus (HPV) infections in young women screened as potential targets for prophylactic HPV vaccination in south of Brazil.

OBJECTIVE: To explore the predictors of intermediate endpoints of cervical cancer in 500 women living in Porto Alegre. STUDY DESIGN: Five hundred randomly selected women (mean age 20.3 years, range 15-25) were screened using PCR detecting 25 HPV types (HPV6, 11, 16, 18, 31, 33, 34, 35, 39, 40, 42, 43, 44, 45, 51, 52, 53, 54, 56, 58, 59, 66, 68, 70, and 74). Women were interviewed and serum samples were analysed for antibodies to HPV16 and HPV18 VLPs. Regression models were constructed to analyse predictive factors for (a) HPV PCR status, (b) HPV16-seropositivity, (c) HPV18-seropositivity, and (d) SIL in the PAP smear, used as intermediate endpoints of cervical cancer. RESULTS: Specific HPV types were identified in 137 (27.4%) of the 157 (31.4%) PCR-positive women. PAP test result was the most powerful independent predictor of HPV status in PCR (p = 0.0001), followed by the sexual activity started (p = 0.001) (adjusted OR 34.075, 95% CI: 4.650-249.715). PAP test SIL was independently predicted only by the HPV PCR status (p = 0.0001) (OR 7.561, 95% CI: 2.787-20.514). HPV16 and HPV18 serostatus were the most significant predictors of each other (p=0.0001), and the life-time number of sexual partners was more significant (p=0.001) predictor of HPV16 than HPV18 serostatus (p = 0.049). CONCLUSION: These data are useful in evaluating the exposure status of the women to the risk factors of cervical cancer in south of Brazil.

Adolescent↗
PubMed2006

Solutions to a combined problem of excessive hydrogen sulfide in biogas and struvite scaling.

The Woodman Point Wastewater Treatment Plant (WWTP) in Western Australia has experienced two separate problems causing avoidable maintenance costs: the build-up of massive struvite (MgNH4PO4. 6H2O) scaling downstream of the anaerobic digester and the formation of hydrogen sulfide (H2S) levels in the digester gas to levels that compromised gas engine operation and caused high operating costs on the gas scrubber. As both problems hang together with a chemical imbalance in the anaerobic digester, we decided to investigate whether both problems could be (feasibly and economically) addressed by a common solution (such as dosing of iron solutions to precipitate both sulfide and phosphate), or by using separate approaches. Laboratory results showed that, the hydrogen sulfide emission in digesters could be effectively and economically controlled by the addition of iron dosing. Slightly higher than the theoretical value of 1.5 mol of FeCl3 was required to precipitate 1 mol of dissolved sulfide inside the digester. Due to the high concentration of PO4(3-) in the digested sludge liquor, significantly higher iron is required for struvite precipitation. Iron dosing did not appear an economic solution for struvite control via iron phosphate formation. By taking advantage of the natural tendency of struvite formation in the digester liquid, it is possible to reduce the risk of struvite precipitation in and around the sludge-dewatering centrifuge by increasing the pH to precipitate struvite out before passing through the centrifuge. However, as the Mg2+/PO4(3-) molar ratio in digested sludge was low, by increasing the pH alone (using NaOH) the precipitation of PO4(3-) was limited by the amount of cations (Ca2+ and Mg2+) available in the sludge. Although this would reduce struvite precipitation in the centrifuge, it could not significantly reduce PO4(3-) recycling back to the plant. For long-term operation, maximum PO4(3-) reduction should be the ultimate aim to minimise PO4(3-) accumulation in the plant. Magnesium hydroxide liquid (MHL) was found to be the most cost-effective chemical to achieve this goal. It enhanced struvite precipitation from both, digested sludge and centrate to the point where more than 95% PO4(3-) reduction in the digested sludge was achieved.

Bacteria, Anaerobic↗
PubMed2005

Evolution of brain-derived neurotrophic factor levels after autologous hematopietic stem cell transplantation in multiple sclerosis.

A neuroprotective role of inflammation has been suggested based on that immune cells are the main source of brain-derived neurotrophic factor (BDNF). We investigated the 3-year evolution of BDNF levels in serum, CSF and culture supernatant of peripheral blood mononuclear cells (PBMC), unstimulated and stimulated with anti-CD3 and soluble anti-CD28 antibodies, in 14 multiple sclerosis patients who underwent an autologous hematopoietic stem cell transplantation (AHSCT). BDNF levels were correlated with previously reported MRI measures that showed a reduction of T2 lesion load and increased brain atrophy, mainly at first year post-transplant. A significant decrease of serum BDNF levels was seen at 12 months post-transplant. BDNF values were found significantly lower in stimulated but not in unstimulated PBMC supernatants during the follow-up, supporting that AHSCT may induce a down-regulation of BDNF production. The only significant correlation was found between CSF BDNF levels and T2 lesion load before and 1 year after AHSCT, suggesting that BDNF reflects the past and ongoing inflammatory activity and demyelination of these highly active patients. Our study suggests that AHSCT can reduce BDNF levels to values associated with lower activity. This decrease does not seem to correlate with the brain atrophy measures observed in the MRI.

Antibodies↗
PubMed2005

Biochemical properties of new synthetic carnosine analogues containing the residue of 2,3-diaminopropionic acid: the effect of N-acetylation.

Three novel carnosine analogues 7-9 containing the residue of L(+)2,3-diaminopropionic acid with different degree of N-acetylation instead of beta-alanine have been synthesized and characterized. Comparative analysis of hydrolysis by carnosinase revealed that the mono- and bis-acetylated compounds 8 and 9 are resistant to enzymatic hydrolysis and act as competitive inhibitors of this enzyme. The hydroxyl radical scavenging potential of the three analogues was evaluated by their ability to inhibit iron/H(2)O(2)-induced degradation of deoxyribose. The second-order rate constants of the reaction of compounds 7-9 with hydroxyl radical were almost identical to that of carnosine. These compounds were also found to act as protective agents against peroxynitrite-dependent damage as assessed by their ability to prevent nitration of free tyrosine induced by this species.

Acetylation↗
PubMed2005

Diabetes: a major co-morbidity of cystic fibrosis.

Cystic fibrosis-related diabetes (CFRD) is a frequent complication of cystic fibrosis, its prevalence increases with age of patient and is close to 30% at the age of 30 years. As life expectancy greatly increases, the number of cystic fibrosis patients developing diabetes will increase too. CFRD shares some features with type 1 and type 2 diabetes, initial phase is characterised by postprandial hyperglycaemia followed by a progression toward insulin deficiency. Insulin deficiency is an essential factor in the development of diabetes with an additional contribution of insulin resistance. Systematic screening with an oral glucose tolerance test is recommended from the age of 14 years because clinical signs of CFRD are often confused with signs of pulmonary infection and CFRD occurrence is associated with weight and pulmonary function deterioration. In observational studies CFRD diagnosis is associated with a significant increase in mortality, while treatment allow correction of weight and lung deterioration suggesting that CFRD has a significant impact on CF evolution. Microvascular complications are recognised, although paucity of data does not permit a clear description of their natural history. Annual screening for microvascular complication is recommended. There is no evidence by now that CF patients develop macrovascular complications. The only recommended pharmacological treatment is insulin therapy.

Comorbidity↗
PubMed2005

In vivo and in vitro analysis of the human tissue-type plasminogen activator gene promoter in neuroblastomal cell lines: evidence for a functional upstream kappaB element.

Besides its well-established role in wound healing and fibrinolysis, tissue-type plasminogen activator (t-PA) has been shown to contribute to cognitive processes and memory formation within the central nervous system, and to promote glutamate receptor-mediated excitotoxicity. The t-PA gene is expressed and regulated in neuronal cells but the regulatory transcriptional processes directing this expression are still poorly characterized. We have used DNase I-hypersensitivity mapping and in vivo foot printing to identify putative regulatory elements and transcription factor binding sites in two human neuroblastomal (KELLY and SK-N-SH) and one human glioblastomal (SNB-19) cell lines. Hypersensitive sites were found in the proximal promoter region of all cell lines, and within the first exon for KELLY and SNB-19 cells. Mapping of methylation-protected residues in vivo detected a cluster of protected residues corresponding to a cAMP response element (CRE) and Sp1 sites in the proximal promoter previously shown to be essential for basal expression in other cell types. Protected residues were also found at other sites, notably a kappaB element at position bp -3081 to -3072 that was partly protected in KELLY and SNB-19 cells. Analysis of transfected reporter constructs in KELLY and SNB-19 cells confirmed that this particular element is functionally significant in the transactivation of the t-PA promoter in both cell types. This study defines, by in vivo and in vitro methods, a previously undescribed kappaB site in the t-PA gene promoter that influences t-PA expression in neuronal cells.

Cell Line, Tumor↗
PubMed2004

Nickel(II) binding to Cap43 protein fragments.

Cap43 protein has been tested for metal binding domains. The protein, specifically induced by nickel compounds in cultured human cells, had a new mono-histidinic motif consisting of 10 amino acids repeated three times in the C-terminus. The 20-Ac-TRSRSHTSEG-TRSRSHTSEG (Thr(341)-Arg-Ser-Arg-Ser-His(346)-Thr-Ser-Glu-Gly-Thr-Arg-Ser-Arg-Ser-His(356)-Thr-Ser-Glu-Gly(360) - peptide 1) and the 30-Ac-TRSRSHTSEG-TRSRSHTSEG-TRSRSHTSEG (Thr(341)-Arg-Ser-Arg-Ser-His(346)-Thr-Ser-Glu-Gly-Thr-Arg-Ser-Arg-Ser-His(356)-Thr-Ser-Glu-Gly-Thr-Arg-Ser-Arg-Ser-His(366)-Thr-Ser-Glu-Gly(370) - peptide 2) amino acids sequence has been analyzed as a site for Ni(II) binding. A combined pH-metric and spectroscopic (UV-visible, CD, NMR) studies of Ni(II) binding to both fragments were performed. The 20-amino acid peptide can bind one and two metal ions while the 30-amino acid fragment one, two and three metal ions. At physiological pH, depending on the metal to ligand molar ratio, peptide 1 forms the Ni(2)L species while peptide 2 the NiL, Ni(2)L and Ni(3)L complexes where each metal ion is coordinated to the imidazole nitrogen atom of the histidine residue of the 10-amino acid fragment. Octahedral complexes at pH 8-9 and planar 4N complexes with (N(Im), 3N(-)) bonding mode at pH above 9, are formed. This work supports the existence of an interesting binding site at the COOH-terminal domain of the Cap43 protein.

Amino Acid Motifs↗
PubMed2004

Effectiveness of diet in hyperlipidemia in renal transplant patients.

In renal transplant patients dietary therapy alone does not always provide satisfactory results to control hyperlipidemia. To assess the effectiveness of diet, 151 renal transplant patients were selected for a prospective clinical study using pre- and posttest groups. During 8 weeks these patients received a diet with 25% energy intake from lipids, less than 10% from saturated fats, and less than 500 mg of cholesterol per day. Total cholesterol, LDL cholesterol, HDL cholesterol, and triglycerides were measured (pre- versus postdiet). The degree of compliance with the diet was measured by a 24-hour food recall record. Patients who had 90% compatibility between the questionnaire and the prescribed diet were considered compliant. The diet was considered effective in the patients who achieved a reduction of cholesterolemia to less than 200 mg/dL after 8 weeks of treatment. Ultimately 108 patients completed the study, with a significant reduction in total serum cholesterol from 262.37 mg/dL pretest to 252.85 mg/dL posttest (P =.010); LDL cholesterol from 174.29 mg/dL pretest to 166.60 mg/dL posttest (P =.036), of body weight from 68.98 kg pretest to 67.78 kg posttest (P =.01) and of body mass index from 25.86 kg/m(2) pretest to 25.41 kg/m(2) posttest (P =.01). Cholesterol variation was 3.63% as compared to prediet levels. Only 22 patients (20.4%) achieved cholesterol levels below 200 mg/dL. In conclusion, although diets decrease cholesterolemia, they alone are not effective to control hyperlipidemia in most renal transplant patients.

Adult↗
PubMed2004

[Evolution study in children with suspected obstructive sleep apnea].

INTRODUCTION: Obstructive sleep apnea syndrome is a common disorder in childhood with an uncertain evolution. OBJECTIVES: Study of children's clinical evolution with suspected diagnosis of OSAS, which was carried out after two years of an overnight polisomnogram. PATIENTS AND METHODS: 73 children were studied. We evaluated if they had been operated and what type of surgery was performed, Brouillete Scale and subjective impressions. We have correlated: age, clinical evolution and surgery. RESULTS: Age was inversely correlated with changes in Brouillete (r=-0.39, p=0.002), standing out that children that underwent surgery were younger (4.1 vs. 7.0 years, Student t: -4.22, p=0.00009). Without the influence of age, the difference between evolution in operated and not operated ones was not significative, statistically speaking, but it was if we analysed the different types of surgery by themselves (Snedecor F: 3.9, p=0.007), tonsillectomy was the larger. CONCLUSION: The middle-term evolution in children with OSAS is good if we use the correct treatment.

Adenoidectomy↗