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Biomedical subjects

R Nunes

Publications and source records attributed to R Nunes.

At least 19 recordsLinked to original sources
PubMed2004

Endoscopic sphincterotomy for prevention of the recurrence of acute biliary pancreatitis in patients with gallbladder in situ: long-term follow-up of 88 patients.

BACKGROUND: Endoscopic sphincterotomy without cholecystectomy is a therapeutic option in selected patients after acute biliary pancreatitis. We conducted a prospective evaluation of the long-term effects of sphincterotomy in terms of the need for of subsequent cholecystectomy and the recurrence of gallstone pancreatitis. METHODS: We studied 88 patients with acute biliary pancreatitis and an intact gallbladder who, underwent endoscopic sphincterotomy either because they were high-risk candidates for surgery or because they had refused of cholecystectomy. The median follow-up was 51 months (range, 5-86). RESULTS: Only two patients (2.2%) experienced recurrent pancreatitis. Subsequent cholecystectomy was performed in 10 patients because of acute cholecystitis in eight cases and biliary colic in two cases. Sixty-six patients (75%) remained asymptomatic. CONCLUSIONS: Endoscopic sphincterotomy is a safe and acceptable alternative to cholecystectomy for the prevention of recurring attacks of gallstone pancreatitis. As a result of this procedure, 75% of patients remained free of symptoms in the long term.

Acute Disease↗
PubMed2001

Multicenter evaluation of resistance patterns of Klebsiella pneumoniae, Escherichia coli, Salmonella spp and Shigella spp isolated from clinical specimens in Brazil: RESISTNET Surveillance Program.

Surveillance programs are essential to detect the increase of antimicrobial resistance, and several different programs are being conducted in many countries. The RESISTNET is a surveillance program for bacterial resistance against several antimicrobial agents initiated in 1998 among Latin American countries. In Brazil, several centers were invited to join this surveillance and a total of 11 centers (6 from São Paulo and 5 from other states) participated in the study. All results were analyzed using the WHONET program. A total of 894 Escherichia coli, 386 Klebsiella pneumoniae, 70 Shigella spp and 57 Salmonella spp strains were analyzed in this study from April, 1998, to April, 1999. Susceptibility testing was performed by the disk diffusion method using NCCLS 1998 guidelines for several different drugs. For all strains, imipenem was the most effective drug (100% of the strains were susceptible). Klebsiella pneumoniae presented a high resistance rate to ampicillin (96.4%). The rate of probable ESBL producers among K. pneumoniae strains was 36.3%, most of them being isolated from catheters (58.8%). Among all Escherichia coli strains analyzed, the highest resistance rate was found for trimethoprim/sulfamethoxazole (46.9%) and the majority of the resistant strains were isolated from urine samples (47.8%). Among Salmonella spp, the resistance rates were low for all antibiotics tested. For Shigella spp strains there was a high resistance to trimethoprim/sulfamethoxazole (80.0%). No resistance to ceftriaxone was observed in these strains. Surveillance of antimicrobial resistance is critical for the successful management of infectious diseases. The results of this survey show significant resistance rates among these bacteria which are responsible for several types of human infections.

Anti-Bacterial Agents↗
PubMed2001

Ethical dimension of paediatric cochlear implantation.

In congenitally or prelingually deaf children cochlear implantation is open to serious ethical challenge. The ethical dimension of this technology is closely related to both a social standard of quality of life and to the uncertainty of the overall results of cochlear implantation. Uncertainty with regards the acquisition of oral communicative skills. However, in the western world, available data suggest that deafness is associated with the lowest educational level and the lowest family income. Notwithstanding the existence of a Deaf-World, deafness should be considered as a handicap. Therefore, society should provide the means for the fulfilment of a deaf child's specific needs. For the time being there is no definitive answer with regard the best way to rehabilitate a particular deaf child. Therefore, communitarian values may be acceptable. If the deaf child parents' decide not to implant, their decision should be respected. Guardians are entitled to determine which standard of best interest to use in a specific circumstance. They are the proper judges of what (re)habilitation process is best for their deaf child. However, most deaf children are born to two hearing parents. Probably, they will not be acculturated in the Deaf-World. It follows that cochlear implantation is a welcomed (re)habilitation technology. If auditory (re)habilitation will in the future provide the necessary communicative skills, in particular oral language acquisition, customs, values and attitudes of the hearing world should be regarded as necessary to accomplish a deaf child's right to an open future. If cochlear implantation technology will provide all deaf children with the capacity to develop acceptable oral communicative skills--whatever the hearing status of the family and the cultural environment--then auditory (re)habilitation will be an ethical imperative.

Attitude to Health↗
PubMed2001

PD-L2 is a second ligand for PD-1 and inhibits T cell activation.

Programmed death I (PD-I)-deficient mice develop a variety of autoimmune-like diseases, which suggests that this immunoinhibitory receptor plays an important role in tolerance. We identify here PD-1 ligand 2 (PD-L2) as a second ligand for PD-1 and compare the function and expression of PD-L1 and PD-L2. Engagement of PD-1 by PD-L2 dramatically inhibits T cell receptor (TCR)-mediated proliferation and cytokine production by CD4+ T cells. At low antigen concentrations, PD-L2-PD-1 interactions inhibit strong B7-CD28 signals. In contrast, at high antigen concentrations, PD-L2-PD-1 interactions reduce cytokine production but do not inhibit T cell proliferation. PD-L-PD-1 interactions lead to cell cycle arrest in G0/G1 but do not increase cell death. In addition, ligation of PD-1 + TCR leads to rapid phosphorylation of SHP-2, as compared to TCR ligation alone. PD-L expression was up-regulated on antigen-presenting cells by interferon gamma treatment and was also present on some normal tissues and tumor cell lines. Taken together, these studies show overlapping functions of PD-L1 and PD-L2 and indicate a key role for the PD-L-PD-1 pathway in regulatingT cell responses.

Amino Acid Sequence↗
PubMed2001

Ethical and legal issues in xenotransplantation.

In most western countries, there is a 'human organ shortage' with waiting lists for the performance of transplantation. In a recent report of the UNOS Ethics Committee it is stated that there are approximately 31,000 potential recipients on waiting lists, but only one fourth of potential donors give their specific consent. Xenotransplantation--defined as the transplantation of animal cells, tissues or organs into human beings--is associated with particular ethical dilemmas, namely the problems of efficiency and safety of this medical procedure. The objective of this study is to analyse the ethical dilemmas in xenotransplantation with the background of a personal view of moral life. Also, xenotransplantation will be evaluated as far as the legal regulation of transplantation is concerned. In particular, we will consider patients rights in accordance with existing laws on organ and tissue transplantation, animal research and clinical trials.

Animal Experimentation↗
PubMed2001

Phaeohyphomycotic cyst caused by Colletotrichum crassipes.

A case of phaeohyphomycosis is reported in a male renal transplant recipient with a nodular lesion in the right leg who was treated with immunosuppressing drugs. The lesion consisted of a purulent cyst with thick walls. The cyst was excised surgically, and the patient did not receive any antifungal therapy. One year later he remains well. Histological study of the lesion showed a granulomatous reaction of epithelioid and multinucleate giant cells, with a central area of necrosis and pus. Fontana-Masson staining demonstrated the presence of pigmented hyphal elements. The fungus Colletotrichum crassipes was grown in different cultures from the cyst. The in vitro inhibitory activities of eight antifungal drugs against the isolate were tested. Clotrimazole and UR-9825 were the most active drugs. This case represents the first known reported infection caused by this rare species.

Adult↗
PubMed1999

Cardiac papillary fibroelastoma of a mitral valve chordae revealed by stroke.

We report the case of a young male patient referred to our hospital after having a stroke due to a papillary fibroelastoma arising from a mitral valve chorda. The tumor was identified by two-dimensional echocardiography and was treated by surgery with preservation of valve integrity. Cardiac papillary fibroelastoma as an uncommon source of cerebral emboli is discussed.

Adult↗
PubMed1999

Efficacy of the nocturnal bite plate in the control of bruxism for 3 to 5 year old children.

Bruxism occurs in nearly 60% of children between 3 and 5 years, with important repercussions to the different components of the stomatognathic system. Nevertheless, there is little information in the literature about this topic. The aim of this study was to compare two groups of children with bruxism. One group was not submitted to treatment, serving as a control. To the other group, nocturnal bite plate was made. Cast models were made for both groups, to evaluate the progression of wear facets, during 8 months. The results are as follows: The 4 children of the control group displayed increased wear facets during the study period. On the other hand, of the 5 children that used nocturnal bite plate, showed no increase of wear facets, even after the removal of the device. From this study, we can conclude that the use of nocturnal bite plate is efficient against bruxism in 3- to 5-year-old children.

Bruxism↗
PubMed1997

[Systemic vasculitis as the initial presentation of a left atrial myxoma].

Left atrial myxoma remains a diagnostic challenge. The authors briefly review previously reported cases and their individualistic clinical and laboratory features. This report documents an unusual clinical presentation, initially directing attention to the central nervous system as well as bilateral tenderness and weakness of the extremities. The illness was considered to be a vasculitis until thirty-one months later when the diagnosis of left atrial myxoma was made. The tumor was successfully removed.

Diagnosis, Differential↗
PubMed1991

Evaluation of newborn arm circumference as an indicator of low birth weight.

A sample of 1,024 newborns in Recife, Brazil, was studied to help determine the precision with which arem circumference measurements could be used to indicate low birth weight. The results support the view that when birth weight data are unobtainable, arm circumference measurements may be of value in screening for newborns needing special care.

Anthropometry↗
PubMed1991

[Valve replacement with Macchi prosthesis].

OBJECTIVE: to evaluate the performance of a new ball valve prosthesis. DESIGN: set up of two groups of patients who underwent mitral valve replacement with two different prosthesis: the Macchi prosthesis under evaluation and the well known Starr-Edwards model prosthesis. The chi-square test was used to compare the results. PATIENTS: Patients referred for valvular surgery. INTERVENTIONS: One group of 98 consecutive patients who underwent isolated mitral valve replacement with a Macchi prosthesis from January 1984 to June 30 1986 was compared to a matched group of 49 patients who received a Starr-Edwards prosthesis in the same period of time. Follow-up data were available from 99% patients in the Macchi group 96% in the Starr-Edwards group, with a mean follow-up time of 35.2 (2-57) and 42.9 (4-62) months, respectively. RESULTS: There was no statistical difference in the incidence per 100 patients--month of prosthetic complications--thromboembolism, hemorrhagic events, prosthetic endocarditis, reoperation and mechanical failure. CONCLUSIONS: In our experience and with the available follow-up data the Macchi prosthesis is a good cost effective option when there is indication for a ball valve prosthesis.

Adult↗
PubMed1991

[Determination of the arm circumference in newborn infants as a method of verifying low birth weight].

The authors studied 1,024 newborns in Recife, Brazil, to determine the association between arm circumference and birth weight. A strong correlation between these two parameters was found (R = +0.78). Specificity and sensitivity of this measurement in detecting low birth weight were also high. The authors concluded that arm circumference can be used as an alternative method of detecting at-risk neonates in areas where birth weight cannot be measured accurately.

Anthropometry↗
PubMed1988

'Albumin-receptor' uptake kinetics do not require an intact lobular architecture and are not specific for albumin.

When freshly isolated well-stirred single cell suspensions of rat hepatocytes were incubated with 5-600 microM [3H]oleate or [35S]sulfobromophthalein (BSP) in the presence of 150 microM bovine serum albumin (BSA), uptake of both ligands increased as a linear function of the total ligand concentration in the medium. By contrast, when the same ligand concentrations were incubated as 1:1 complexes with BSA, apparent saturation of ligand uptake was observed. Analogous results were obtained in incubations employing beta-lactoglobulin instead of BSA. In none of these studies did ligand uptake velocity correlate in simple fashion with the concentration of unbound ligand in the incubation medium. These studies establish that the basis for the kinetic observations termed the 'albumin receptor phenomenon' does not require an intact hepatic lobular architecture or space of Disse, and is not specific for albumin.

Animals↗
PubMed1986

Studies of the hepatocellular uptake of the hepatobiliary scintiscanning agent 99mTc-DISIDA.

Bilirubin (BR) and organic anionic dyes such as sulfobromophthalein (BSP), indocyanine green (ICG) and rose bengal (RB) enter the hepatocyte by a specific non-sodium-dependent membrane transport system. Two analogous but distinct Na+-dependent transport systems effect the uptake of conjugated bile acids such as taurocholate (TC) and free fatty acids such as oleate, respectively. The mechanism of uptake of the acetanilidoiminodiacetic acid (HIDA) class of biliary scintiscanning agents is unknown. Accordingly, rat hepatocytes were isolated by collagenase perfusion of the liver and differential centrifugation, and incubated with 99mTc-diisopropyl-HIDA (99mTc-DISIDA) alone, or in the presence of various concentrations of BSP, ICG, RB, oleate or TC, with and without bovine serum albumin (BSA). Initial uptake velocity (Vo) was determined from the initial slope of the cumulative radioactivity/time curve. In albumin free media, uptake of 99mTc-DISIDA was temperature- and pH-dependent, with maximal uptake at 37 degrees C. There was virtually no uptake of inorganic 99mTc. In incubations containing 15-1500 microM 99mTc-DISIDA, Vo was saturable, with estimated Vmax = 65 nmoles/min/10(6) hepatocytes, and Km = 1200 microM. In keeping with its weak albumin binding, 99mTc-DISIDA Vo was only minimally influenced by equimolar concentrations of BSA. 99mTc-DISIDA Vo was inhibited by BR, BSP, ICG and RB, as well as by a rabbit antibody to the rat liver plasma membrane BSP/BR binding protein. Surprisingly, Vo was also inhibited by TC and oleate, but not influenced either by ouabain or by substitution of Li+ for Na+ in the medium.(ABSTRACT TRUNCATED AT 250 WORDS)

Albumins↗
PubMed1986

Water and nonelectrolyte permeability of isolated rat hepatocytes.

We have measured the diffusive permeability coefficients of isolated rat hepatocytes to 3H2O, [14C]urea, [14C]erythritol, [14C]mannitol, [3H]sucrose, and [3H]inulin, employing a technique previously developed for erythrocytes (Redwood et al., J. Gen. Physiol 64:706-729, 1974). Diffusion coefficients for the tracer molecules were measured in packed hepatocytes, supernatant fluid, and intracellular medium (lysed hepatocytes) and were calculated assuming one-dimensional semi-infinite diffusion through a homogeneous medium. By applying the series-parallel pathway model, the following permeability coefficients (10(-5) cm/sec) for the hepatocyte plasma membrane were obtained. 3H2O, 98.6 +/- 18.4; [14C]urea, 18.2 +/- 5.3; [14C]erythritol, 4.8 +/- 1.6; [14C]mannitol, 3.1 +/- 1.4; [3H]sucrose, 0; [3H]inulin, 0. These results indicate that isolated rat hepatocytes are highly permeable to water and polar nonelectrolytes, when compared with other transporting epithelia. This relatively high cellular permeability is consistent with a model in which nonelectrolyte permeation is via an aqueous pathway of equivalent pore diameter of 8-12 A. The finding that [14C]erythritol and [14C]mannitol cross the hepatocyte plasma membrane indicates that these molecules enter the bile canaliculus through the transcellular route. Conversely, the failure of [3H]sucrose and [3H]inulin to permeate the hepatocyte in the isolated condition supports the concept that biliary entry of these large carbohydrates, at least that fraction which cannot be accounted for by a vesicular mechanism, must occur via the transjunctional shunt pathway.

Animals↗