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Biomedical subjects

I Pinto

Publications and source records attributed to I Pinto.

At least 19 recordsLinked to original sources
PubMed2006

Synthesis and characterization of membranes obtained by graft copolymerization of 2-hydroxyethyl methacrylate and acrylic acid onto chitosan.

Chitosan based membranes to be applied on wound healing as topical drug delivery systems were developed by graft copolymerization of acrylic acid (AA) and 2-hydroxyethyl methacrylate (HEMA) onto chitosan using cerium ammonium nitrate as chemical initiator. Evidence for graft copolymerization of the vinyl monomers onto chitosan was obtained by FTIR and DMTA. Swelling degree, cytotoxicity, thrombogenicity and haemolytic activity of these membranes were evaluated. Chitosan-graft-AA-graft-HEMA showed to be the best matrix for drug delivery systems than chitosan-graft-AA because it retains good swelling properties, but the content in HEMA has improved cytocompatibility, hemocompatibility and thrombogenic character.

Acrylates↗
PubMed2006

[Complications in laparoscopic nephrectomy].

OBJECTIVE: To report the complications and their respective management in our series of laparoscopic nephrectomy. MATERIAL AND METHODS: Between November 1992 and March 2004, 319 patients underwent laparoscopic ablative renal surgery: 152 were women and 167 were men, mean age was 45 years (range: 0,5-82 years). There were 70 radical nephrectomies, 16 radical nephroureterectomies, 63 partial nephrectomies, 124 simples nephrectomies, 15 simples nephroureterectomies, 8 heminephrectomies and 23 living donor nephrectomies. RESULTS: The complication rate was 5.64%. The most frequent complications were bleeding (2.5%) and retroperitoneal haematoma (1.2%). There was not statically difference in complications rate by age, sex, or approach via: transperitoneal versus retroperitoneal. Complication rate was alike with laparoscopic or hand assisted technique. There was not mortality in the series. CONCLUSIONS: We have a low complication rate in laparoscopic nephrectomy. We believe that laparoscopy is a safe technique for patients that require ablative renal surgery when the surgical team has experience in advanced laparoscopic surgery.

Adolescent↗
PubMed2006

[Laparoscopic surgery in the treatment of adrenal pathology: experience with 200 cases].

OBJECTIVE: We report our experience in laparoscopic adrenalectomy, after adopting the laparoscopic technique for 10 years as a primary option for suprarenal surgery. METHODS: We included 200 laparoscopic adrenal surgeries performed consecutively in 183 patients with surgical adrenal pathology between November 1994 and November 2005. Sixty-seven (36.6%) patients were male and 116 (63.4%) were female, with an average age of 49.1 years (age range 8 months to 78 years). RESULTS: The most frequents clinical diagnosis were hyperaldosteronism (17.5%), metastatic cancer (15.8%), pheochromocytoma (15.3%), Cushing syndrome (7.1%), adrenal cyst (4.9%) and myelolipoma (2.7%). A total of 164 total adrenalectomies, 29 partial adrenalectomies and 7 marsupializations of adrenal cysts were performed. Mean surgical time was 82.6 minutes (range 25 to 240 minutes) and mean hospitalization time was 2.5 days (range 1-10 days). The size of the suprarenal gland and/or tumor varied between 1 and 14 cm (average 5.6 cm). The rate of complication was 6%. In 8 of the patients, there was another laparoscopic procedure besides the adrenal surgery: cholecystectomies (2), marsupialization of a renal cyst (2), block nephrectomy (2), partial nephrectomy for a tumor (1) and pancreatic cystectomy (1). One patient underwent a right laparoscopic adrenalectomy and an ipsilateral percutaneous nephrolithotomy. CONCLUSION: The accumulated experience with 200 laparoscopic adrenal procedures has allowed the management of endocrine pathologies, such as, aldosteroma, pheochromocytoma, Cushing syndrome and rare entities, such as, cysts, myelolipomas in a suitable manner. Additionally, it has permitted us to extend the benefits of a minimally invasive procedure for large adrenal masses and selected oncology cases.

Adolescent↗
PubMed2006

[Urinary undiversion; Bricker to Studer. With regard of two cases].

We present two cases of urinary undiversion from an ileal loop (Bricker) to an orthotopic neobladder. Due to miss adaptation to the stoma, two patients demanded reconversion to a continent urinary diversion. We proceed to change their urinary diversion to an ileal neobladder (Studer), one by open surgery and the other by laparoscopic surgery. In both cases immediate postoperative went uneventful. Both patients are continent, satisfied with their new situation, and without metabolic complications. Urinary undiversion from an ileal conduit to an orthotopic neobladder is technically feasible by open or laparoscopic surgery. It is a valid alternative for patients with complications due to their urinary diversion or miss adaptation to the cutaneous stoma.

Humans↗
PubMed2005

Reduction of exposure of newborns and caregivers to very high electromagnetic fields produced by incubators.

The aims of this paper is to measure whether ferromagnetic panels sufficiently reduce the high electromagnetic fields (EMF) to which newborns are exposed in incubators and to which caregivers are exposed when working near the incubators. We measured EMF at mattress level in three neonatal incubators with and without ferromagnetic panels between the electric motor and the mattress. We then measured the EMF at the level of the maximum emission point for caregivers, i.e., near the display panel. The ferromagnetic panels were (a) 5 mm thick iron, (b), (c), (d) respectively, one, two, and three sheets of 0.3 mm thick mu-metal. The weight of iron sheet was 4 g/cm2, and mu-metal 0.2 g/cm2. The use of the ferromagnetic panels significantly reduced the EMF. No significant difference in attenuation was recorded using one, two, or, three sheets of mu-metal, or a single sheet of iron. One, two, and three sheets of mu-metal reduced EMFs by 77%, 82%, and 84.3%, respectively; the reduction with iron was 80%. EMF values measured in incubators were higher than those to which the general population is exposed. The use of ferromagnetic panels significantly reduces the level of EMFs to which neonates and caregivers are exposed.

Caregivers↗
PubMed2004

[Vibration risk during neonatal transport].

AIM: The aim of this paper is to assess the entity of the mechanical vibrations which newborn and medical staff are exposed to and to evaluate the possible risks connected with excessive exposure. METHODS: Vibrations during a simulated emergency ambulance transport were studied. Vibration values with an accelerometer at the level of the incubator's mattress and at passengers' and pilot's seat level were measured. Mean accelerations (awz) and peak accelerations (awpeak), measured using a ponderation filter, according with ISO standard 2631, were considered. RESULTS: Inside the incubator an acceleration mean value of 1.33 (+/-0.13) m/s(2) and peak values of 11.8 (+/-0.1) m/s(2) were found. On passengers' seats the awz findings were 0.55 m/s(2) (+/-0.13) and 0.56 m/s(2) (+/-0.08) while awpeak respectively 4.8 m/s(2) (+/-0.1) and 10.2 m/s(2) (+/-0.1). On pilot's seat a mean acceleration of 0.48 m/s(2) (+/-0.08) and an awpeak value of 4.5 m/s(2) (+/-0.1) were found. CONCLUSION: Peak vibration values which newborns are exposed to (11.8 m/s(2)) are high, when compared with acceleration of gravity (9.8 m/s(2)); this can provoke repeated jerks. Environmental stress can easily alter the stability of an ill newborn and interfere with care manoeuvres. Decreasing vibrations in neonatal transport unit could increase the safety of newborns, reducing the risks which newborns are actually exposed to.

Humans↗
PubMed2003

Treatment of complete obstruction of the nasolacrimal system by temporary placement of nasolacrimal polyurethane stents: preliminary results.

AIM: To assess the efficacy of the temporary placement of polyurethane nasolacrimal stents as a treatment for complete post-saccal obstruction of the lacrimal apparatus. MATERIALS AND METHODS: Polyurethane nasolacrimal stents were inserted under radiological guidance in nine patients with grade IV epiphora due to complete obstruction of the lacrimal system, at the junction of the lacrimal sac and duct (eight patients) or in the lacrimal duct (one patient). On average, the stents were removed 4 months (range: 3-6 months) after insertion. Dacryocystography was performed immediately before and after each stent was removed. Subsequently, periodic clinical and radiological examinations were performed until recurrence of the epiphora, at which point follow-up concluded. RESULTS: All patients remained free of epiphora and clinical inflammation while the stents were in place, but re-obstruction of the lacrimal system occurred in all patients less than 2 months after the stents were removed. Adhesion of three stents to the lacrimal tract was observed upon removal. In seven cases the dacryocystography results at the end of follow-up revealed changes in the configuration of the lacrimal apparatus. CONCLUSION: Based on our preliminary experience, temporary placement of polyurethane stents would not appear to be an efficacious therapeutic option for treating epiphora caused by post-saccal obstruction.

Adult↗
PubMed2002

[Cauda equina meningioma in a girl: presentation of a case and review of the literature].

Meningiomas are unusual in childhood, and the intraspinal location is very uncommon. Those arising from lumbar dura matter are the most rare among spinal neoplasms of meningeal origin. We present the case of a 12-years-old girl with a cauda equina meningioma. As in previously reported cases, the initial complain was back pain with radicular irradiation. The girl had few neurological findings, with pyramidal signs of both lower limbs as single neurological impairment. She underwent surgical treatment through an open door laminoplasty and the tumour was completely removed without neurological deficit. After 2-year of follow-up she remains asymptomatic.

Back Pain↗
PubMed2001

The peroxisome proliferator-activated receptor delta promotes lipid accumulation in human macrophages.

The peroxisome proliferator-activated receptors (PPARs) are a family of fatty acid-activated transcription factors which control lipid homeostasis and cellular differentiation. PPARalpha (NR1C1) controls lipid oxidation and clearance in hepatocytes and PPARgamma (NR1C3) promotes preadipocyte differentiation and lipogenesis. Drugs that activate PPARalpha are effective in lowering plasma levels of lipids and have been used in the management of hyperlipidemia. PPARgamma agonists increase insulin sensitivity and are used in the management of type 2 diabetes. In contrast, there are no marketed drugs that selectively target PPARdelta (NR1C2) and the physiological roles of PPARdelta are unclear. In this report we demonstrate that the expression of PPARdelta is increased during the differentiation of human macrophages in vitro. In addition, a highly selective agonist of PPARdelta (compound F) promotes lipid accumulation in primary human macrophages and in macrophages derived from the human monocytic cell line, THP-1. Compound F increases the expression of genes involved in lipid uptake and storage such as the class A and B scavenger receptors (SRA, CD36) and adipophilin. PPARdelta activation also represses key genes involved in lipid metabolism and efflux, i.e. cholesterol 27-hydroxylase and apolipoprotein E. We have generated THP-1 sublines that overexpress PPARdelta and have confirmed that PPARdelta is a powerful promoter of macrophage lipid accumulation. These data suggest that PPARdelta may play a role in the pathology of diseases associated with lipid-filled macrophages, such as atherosclerosis, arthritis, and neurodegeneration.

Animals↗
PubMed2001

Acute myocardial infarction in progressively elderly patients. A comparative analysis of immediate results in patients who underwent primary percutaneous coronary intervention.

OBJECTIVE: Analysis of the in-hospital results, in progressively elderly patients who undergo primary percutaneous coronary intervention (PCI) in the first 24 hours of AMI. METHODS: The patients were divided into three different age groups (60/69, 70/79, and > or =80 years) and were treated from 7/95 until 12/99. The primary success rate and the occurrence of major clinical events were analyzed at the end of the in-hospital phase. Coronary stent implantation and abciximab use were employed at the interventionist discretion. RESULTS: We analyzed 201 patients with age ranging from 60 to 93 years, who underwent primary PCI. Patients with ages above 70 were more often female (p=.015). Those with ages above 80 were treated later with PCI (p=.054), and all of them presented with total occlusion of the infarct-related artery. Coronary stents were implanted in 30% of the patients. Procedural success was lower in > or =80 year old patients (p=.022), and the death rate was higher in > or =70 years olds (p=.019). Reinfarction and coronary bypass surgery were uncommon events. A trend occurred toward a higher combined incidence of major in-hospital events according to increased age (p=.064). CONCLUSION: Elderly patients (> or =70 years) presented with adverse clinical and angiographic profiles and patients > or =80 years of age obtained reduced TIMI 3 flow success rates after primary PTCA, and those > or =70 years had a higher death rate.

Age Distribution↗
PubMed2000

Histone H2A is required for normal centromere function in Saccharomyces cerevisiae.

Histones are structural and functional components of the eukaryotic chromosome, and their function is essential for normal cell cycle progression. In this work, we describe the characterization of two Saccharomyces cerevisiae cold-sensitive histone H2A mutants. Both mutants contain single amino acid replacements of residues predicted to be on the surface of the nucleosome and in close contact with DNA. We show that these H2A mutations cause an increase-in-ploidy phenotype, an increased rate of chromosome loss, and a defect in traversing the G(2)-M phase of the cell cycle. Moreover, these H2A mutations show genetic interactions with mutations in genes encoding kinetochore components. Finally, chromatin analysis of these H2A mutants has revealed an altered centromeric chromatin structure. Taken together, these results strongly suggest that histone H2A is required for proper centromere-kinetochore function during chromosome segregation.

Base Sequence↗
PubMed1999

Mutational analysis of yeast TFIIB. A functional relationship between Ssu72 and Sub1/Tsp1 defined by allele-specific interactions with TFIIB.

TFIIB is an essential component of the RNA polymerase II core transcriptional machinery. Previous studies have defined TFIIB domains required for interaction with other transcription factors and for basal transcription in vitro. In the study reported here we investigated the TFIIB structural requirements for transcription initiation in vivo. A library of sua7 mutations encoding altered forms of yeast TFIIB was generated by error-prone polymerase chain reaction and screened for conditional growth defects. Twenty-two single amino acid replacements in TFIIB were defined and characterized. These replacements are distributed throughout the protein and occur primarily at phylogenetically conserved positions. Most replacements have little or no effect on the steady-state protein levels, implying that each affects TFIIB function rather than synthesis or stability. In contrast to the initial sua7 mutants, all replacements, with one exception, have no effect on start site selection, indicating that specific TFIIB structural defects affect transcriptional accuracy. This collection of sua7 alleles, including the initial sua7 alleles, was used to investigate the allele specificity of interactions between ssu72 and sub1, both of which were initially identified as either suppressors (SUB1 2mu) or enhancers (sub1Delta, ssu72-1) of sua7 mutations. We show that the interactions of ssu72-1 and sub1Delta with sua7 are allele specific; that the allele specificities of ssu72 and sub1 overlap; and that each of the sua7 alleles that interacts with ssu72 and sub1 affects the accuracy of transcription start site selection. These results demonstrate functional interactions among TFIIB, Ssu72, and Sub1 and suggest that these interactions play a role in the mechanism of start site selection by RNA polymerase II.

DNA-Binding Proteins↗
PubMed1999

Acute colorectal obstruction: treatment with self-expandable metallic stents before scheduled surgery--results of a multicenter study.

PURPOSE: To evaluate the efficacy of treatment with self-expandable metallic stents for acute colonic obstruction before elective surgical resection. MATERIALS AND METHODS: In 71 patients with malignant obstruction seen from October 1993 through December 1996, lesions were located in the transverse colon in one patient, in the descending colon in 22 patients, and in the rectosigmoid region in 48. A total of 72 self-expandable metallic stents were implanted within 24 hours of diagnosis. RESULTS: Technical success was obtained in 64 patients (90%). In two cases (3%), it was not possible to advance across the obstructing mass. In five cases (7%), the prostheses were poorly positioned at the site of obstruction, requiring placement of a new stent in three cases. Clinical improvement and resolution of the obstruction were confirmed in 66 patients (93%) within 96 hours. Minor complications developed in nine cases (13%). One patient (1%) underwent surgery to resolve a colonic perforation caused by wires at the ends of the stent. The mean time between stent placement and surgery was 8.6 days (range, 6-16 days). CONCLUSION: Implantation of colorectal stents is a safe treatment of acute malignant colonic obstruction before resection.

Acute Disease↗
PubMed1999

Safety and efficacy of coronary stent implantation. Acute and six month outcomes of 1,126 consecutive patients treated in 1996 and 1997.

PURPOSE: The authors analyzed the 30-day and 6-month outcomes of 1,126 consecutive patients who underwent coronary stent implantation in 1996 and 1997. METHODS: The 30-day results and 6-month angiographic follow-up were analyzed in patients treated with coronary stents in 1996 and 1997. All patients underwent coronary stenting with high-pressure implantation (> 12 atm) and antiplatelet drug regimen (aspirin plus ticlopidine). RESULTS: During the study period, 1,390 coronary stents were implanted in 1,200 vessels of 1,126 patients; 477 patients were treated in the year 1996 and 649 in 1997. The number of percutaneous procedures performed using stents increased significantly in 1997 compared to 1996 (64% vs 48%, p = 0.0001). The 30-day results were similar in both years: the success and stent thrombosis rates were equal (97% and 0.8%, respectively). The occurrence of new Q wave MI (1.3% vs 1.1%, 1996 vs 1997, p = NS), emergency coronary bypass surgery (1% vs 0.6%, 1996 vs 1997, p = NS) and 30-day death rates (0.2% vs 0.5%, 1996 vs 1997, p = NS) were similar. The 6-month restenosis rate was 25% in 1996 and 27% in 1997 (p = NS); the target vessel revascularization rate was 15% in 1996 and 16% in 1997 (p = NS). CONCLUSIONS: Intracoronary stenting showed a high success rate and a low incidence of 30-day occurrence of new major coronary events in both periods, despite the greater angiographic complexity of the patients treated with in 1997. These adverse variables did not have a negative influence at the 6-month clinical and angiographic follow-up, with similar rates of restenosis and ischemia-driven target lesion revascularization rates.

Aged↗
PubMed1999

Coronary angioplasty in Brazil.

In 1979, the first transluminal coronary angioplasty (PTCA) was performed in Brazil, two years after the original contribution of Andreas Gruentzig, in Zurich. In the years which followed, the development of PTCA in the country grew and in the mid eighties several centres had already had the experience of more than 600 cases. In the beginning of the nineties, PTCA underwent an additional promotion with a large number of procedures, now subventioned by the bodies of public health. In addition to this, the introduction of new technologies such as directional atherectomy, rotablator, laser and stents. In 1991, the Brazilian Society of Interventional Cardiology created a national registry (CENIC) to gather data on the coronary procedures performed in the country. The CENIC data for the 1992/1993 and 1996/1997 bienniums were compared and it was observed that there had been a significant increase in the number of cases treated (from 16,429 in 92/93 to 22,025 in 96/97), complex lesions of the B/C type (from 71.4% to 92.3%), patients with previous revascularisation (from 22% to 28.3%), acute myocardial infarction (from 16% to 17.4%) and multiarterial lesions (from 34.4% to 38.8%). However, despite a greater clinical and angiographic complexity, the success of the procedure grew (from 89.7% to 92.8%) and complications reduced: acute occlusion (from 3.2% to 1.5%); acute myocardial infarction (from 2.5% to 1.2%) and death (from 1.8% to 1.4%). Interventional cardiology in Brazil has consequently progressed at the same rate as that of other countries. The incorporation of new technologies, particularly coronary endoprostheses has increased, guaranteeing better success rates, better results and a decrease in complications arising from acute occlusion of the target vessel.

Angioplasty, Balloon, Coronary↗