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Biomedical subjects

I Pinto

Publications and source records attributed to I Pinto.

At least 37 records · Page 2Linked to original sources
PubMed1998

Acute colorectal obstruction: stent placement for palliative treatment--results of a multicenter study.

PURPOSE: To evaluate the usefulness of stent implantation as a palliative treatment in patients with acute colonic obstruction who are not surgical candidates. MATERIALS AND METHODS: Twenty-four patients (eight women, 16 men; age range, 60-98 years) with acute colonic obstruction underwent colonic stent placement. In nine patients, the procedure was considered a primary palliative treatment; seven patients had a previous diagnosis of disseminated neoplastic disease, and two were not surgical candidates because of their poor general condition. In the remaining 15 patients, stent placement was considered the definitive palliative treatment after tumor staging. The mean time of follow-up was 8.4 months (range, 1-24 months) for patients who lived and 6.3 months (range, 1-12 months) for those who died. RESULTS: Stent placement was successful in all patients. Clinical and radiographic findings of bowel obstruction resolved within 24 hours after stent placement in 23 (96%) patients. None of the patients required colostomy for bowel decompression after immediate stent placement. Complications developed in 10 (42%) patients: Two (8%) patients had mild rectal bleeding; three (12%), abdominal pain; two (8%), malpositioning of the stent; two (8%), pseudo-obstructive episodes due to fecal impaction; and one (4%), occlusive tumor ingrowth into the stent lumen. One (4%) patient underwent surgery to resolve stent malfunction due to poor positioning. Two (8.3%) patients--one with malpositioning of the prosthesis and the other with stent occlusion--required a new stent. The remaining complications required no further treatment. The mortality rate at 6 months was 24%. Eight patients were alive at the time this article was written. CONCLUSION: Colorectal stent placement resulted in successful palliation of acute colonic obstruction in patients with disseminated neoplastic disease.

Acute Disease↗
PubMed1997

Initial results of a new procedure for treatment of malignant obstruction of the left colon.

PURPOSE: This study was undertaken to analyze the results obtained in 38 unselected patients using a new and original procedure for treatment of malignant obstructions of the left colon. METHOD: This procedure involves three phases: 1) resolution of the obstruction by means of a stent placed at the site of the tumor; 2) recovery of the general state of the patient, study of the extent of disease, and mechanical preparation of the colon; 3) regulated and final surgery (if this is not suitable, the stent may be used as definitive palliative treatment). RESULTS: In 35 patients (92 percent), the obstruction was resolved with the stent. In 22 patients the three phases were completed, and in 13 patients the stent constituted definitive palliative treatment. Only one patient (2.6 percent) died after resection of the tumor. CONCLUSION: This procedure offers a new, safe, and efficacious option for treatment of neoplastic colorectal obstructions.

Adenocarcinoma↗
PubMed1997

Application of self-expanding stents in prostate cancer with rectal involvement. Report of two cases and review of the literature.

OBJECTIVES: Rectal involvement due to local spread from prostate cancer is an uncommon finding. When this condition occurs, prognosis is ominous. Our objective is to report our experience in the use of self-expanding endorectal stents in the management of rectal invasion from prostate cancer. Two cases are presented and a review of the literature is carried out. METHODS AND RESULTS: In both cases, self-expanding Wallstent devices were placed (under fluoroscopic control), in order to solve their episodes of bowel obstruction. It was successfully performed in both patients. Therefore, an open surgery procedure was avoided. CONCLUSIONS: When facing the evidence of a tumor that invades the rectal wall, it is important to rule out the existence of prostate cancer (the surgical option in these patients carries an ominous prognosis). Therefore, we propose this new procedure whose results could be very satisfactory in certain settings.

Aged↗
PubMed1995

[The efficacy of iodine prophylaxis in the prevention of endemic goiter in the southwestern area of Asturias].

The aim of the present work was to assess the prevalence of the endemic goiter in Asturias southwestern area (46,000 inhabitants; 6,638 in school age), after 10 years of iodized salt introduction in diet. 317 schooling children were randomly chosen (stratified by age, sex and geographic area). We evaluated thyroid gland size and urinary iodine excretion (microgram of iodine per gram of creatinine = I/C). Previously, studies of infantile population suggested a 63% of prevalence. Our results indicate a decrease to 16.4% of endemic goiter prevalence. Nevertheless, the success of iodine prophylaxis was heterogeneous and not good in some case: point out Ibias population with a prevalence of 48.5% (2,000 inhabitants and 353 in schooling). Remainder population was prevalences between 6.9% and 19.8%. The mean of urinary iodine excretion increased to I/C = 106 (previously I/C = 53). The smallest index I/C become to Ibias population = 78. (p < 0.01 and p < 0.05 with regard to Cangas del Narcea and Tineo population respectively). Only 2 of the 52 cases of goiter were hypothyroidism (but because of autoimmune thyroiditis). We conclude that iodine prophylaxis with salt was effective generally, in order to diminish the endemic goiter in the area.

Adolescent↗
PubMed1995

[Intracoronary isosorbide mononitrate versus placebo. A double-blind study with quantitative coronary angiography].

PURPOSE: To evaluate the vasodilation effect of intracoronary isosorbide mononitrate (ISMN) on the coronary arteries, systolic aortic pressure (SAP) and cardiac rhythms. METHODS: Forty patients aged 61 (40-72) years, 30 (75%) male, were randomized to receive on a double blind fashion, 20 mg of ISMN or placebo. The two groups had similar baseline characteristics. Quantitative coronary arteriography [by cardiovascular measurement system (CMS)] and SAP were compared before and after ISMN. We also observed the cardiac rhythm. RESULTS: There were no arrhythmias. Reference vessel diameter increased from 2.6 +/- 0.5 mm before to 2.9 +/- 0.4 mm after ISMN and did not change, mean 2.9 +/- 0.5 mm, before and after placebo. There was a difference between ISMN and placebo (p < 0.0001). There was no difference in the SAP change between the two groups, 4.2 +/- 0.7 mmHg with ISMN and 1.8 +/- 0.5 mmHg with placebo (p = NS). CONCLUSION: ISMN promotes a safe and effective vasodilation of the coronary arteries with no major effects in cardiac rhythm and systolic aortic pressure.

Adult↗
PubMed1994

Characterization of sua7 mutations defines a domain of TFIIB involved in transcription start site selection in yeast.

The SUA7 gene of Saccharomyces cerevisiae encodes the general transcription factor TFIIB. SUA7 was identified based on the ability of mutations at this locus to shift transcription start site selection at the cyc1 gene downstream of normal. Here, we report the nature of these mutations; the sua7-1 and sua7-2 alleles encode identical E62K replacements, and sua7-3 encodes an R78C replacement. Both Glu-62 and Arg-78 are phylogenetically invariant and occur within the most highly conserved region of TFIIB, immediately distal to a zinc finger motif. A double E62K,R78C mutant was constructed and exhibited the same phenotypes associated with the single mutants, including cold sensitivity and altered start site selection, suggesting that Glu-62 and Arg-78 are functionally related. This observation, and the opposite charge of the 2 residues, suggested that Glu-62 and Arg-78 might interact to form a salt bridge. This was tested by constructing reciprocal E62R and R78E replacements. The E62R mutant is phenotypically identical to the E62K mutant, whereas the R78E mutant is inviable. However, an E62R,R78E double mutant was not only viable but is phenotypically similar to the single mutants. These results define the highly conserved sequence adjacent to the zinc finger of TFIIB as a critical determinant of start site selection and suggest that an Glu-62-Arg-78 salt bridge is an important structural element of that domain.

Alleles↗
PubMed1994

Chronic haemodialysis for very old patients.

There is in the Western World a progressive ageing of the population, and consequently haemodialysis patients are also getting older. Some ethical questions have been raised as a consequence of the economic issues related to the scarcity of available resources. In this paper we review our experience in the treatment of very old chronic haemodialysis patients. Fifty patients (7.2% of our haemodialysis patients) aged over 80 years at the beginning of dialysis were included (f = 25, m = 26, age = 82.6 +/- 0.3 years). In 42% of the patients the aetiology of renal disease was unknown. In the remainder, the aetiology was: interstitial nephritis 26%, hypertensive nephrosclerosis 14%, chronic glomerulonephritis 8%, diabetes 8% and polycystic disease 2%. There was a great comorbidity: intradialytic hypotension 82%, cardiac disease 74%, gastrointestinal disease 32%, cerebrovascular disease 26%. Vascular access related problems were the main reason for hospitalization. The major cause of death was vascular (cardiac and cerebral disease). Actuarial survival was 89%, 78%, 56% and 48% at 6, 12, 24 and 36 months, respectively. We think that haemodialysis is the best available choice for treating very old chronic renal failure patients. However further studies are needed to improve the quality of life of these patients.

Aged↗
PubMed1992

The yeast SUA7 gene encodes a homolog of human transcription factor TFIIB and is required for normal start site selection in vivo.

Mutations in the Saccharomyces cerevisiae SUA7 gene were isolated as suppressors of an aberrant ATG translation initiation codon in the leader region of the cyc1 gene. Molecular and genetic analysis of the cloned SUA7 gene demonstrated that SUA7 is a single copy, essential gene encoding a basic protein (calculated Mr of 38,142) that is homologous to human transcription factor TFIIB. Analysis of cyc1 transcripts from sua7 strains revealed that suppression is a consequence of diminished transcription initiation at the normal start sites in favor of initiation at downstream sites, including a major site between the aberrant and normal ATG start codons. A similar effect was found at the ADH1 locus, establishing that this effect is not cyc1 gene-specific. Thus, SUA7 encodes a yeast TFIIB homolog and functions in transcription start site selection.

Amino Acid Sequence↗
PubMed1992

Isolation and characterization of SUA5, a novel gene required for normal growth in Saccharomyces cerevisiae.

We have identified the sua5 locus as a suppressor of an aberrant ATG codon located in the leader region of the cyc1 gene. The sua5-1 allele enhances the iso-1-cytochrome c steady state level in the cyc1-1019 mutant from 2% to approximately 60% of normal (Cyc+) and also confers a marked slow growth (Slg-) phenotype. Suppression is not a consequence of altered transcription initiation at the cyc1 locus. The SUA5 wild-type gene was isolated and sequenced, revealing an open reading frame (ORF) encoding a potential protein of 46,537 Da. SUA5 transcript analyses were consistent with expression of the predicted ORF and Sua5 antisera detected a protein with an apparent molecular mass of 44 kDa. SUA5 was mapped to chromosome VII, immediately adjacent to the PMR1 gene. Hybridization analysis revealed the presence of a related gene on chromosome XII. Neither the SUA5 DNA sequence nor deduced amino acid sequence showed homology to any sequences in the data banks. Disruption of SUA5 conferred the same Cyc+ and Slg- phenotypes as the sua5-1 suppressor, which is the result of a missense mutation, encoding a Ser107----Phe replacement. In addition, sua5 null mutants lack cytochrome a.a3 and fail to grow on lactate or glycerol medium. These results define SUA5 as a new gene encoding a novel protein that is necessary for normal cell growth.

Alleles↗
PubMed1992

cis- and trans-acting suppressors of a translation initiation defect at the cyc1 locus of Saccharomyces cerevisiae.

The cyc1-362 mutant of Saccharomyces cerevisiae is deficient in iso-1-cytochrome c as a consequence of an aberrant ATG codon that initiates a short open reading frame (uORF) in the cyc1 transcribed leader region. We have isolated and characterized functional revertants of cyc1-362 in an effort to define cis- and trans-acting factors that can suppress the effect of the uORF. Genetic and DNA sequence analyses have defined three classes of revertants: (i) those that acquired point mutations in the upstream ATG (uATG), restoring iso-1-cytochrome c to its normal level; (ii) substitution of the normal A residue at position -1 relative to the uATG by either C or T, enhancing iso-1-cytochrome c production from approximately 2% to 6% (C) or 10% (T) of normal, indicating that the nucleotide immediately preceding the initiator codon can affect the efficiency of AUG start codon recognition and that purines are preferred over pyrimidines at this site; and (iii) extragenic suppressors that enhance iso-1-cytochrome c expression to 10-40% of normal while retaining the uATG. These suppressors are represented by five different genes, designated sua1-sua4 and sua6. In contrast to the previously described sua7 and sua8 suppressors, they do not compensate for the uATG by affecting cyc1 transcription start site selection. Potential suppressor mechanisms are discussed.

Amino Acid Sequence↗
PubMed1992

[Chronic hemodialysis with acetate in patients over 70 years old].

During the last years there has a significant increase of elderly patients included in chronic dialysis programs. No agreement has been reached about the preferable treatment modality. In this study we analyse our experience in the management of patients over 70 years of age undergoing chronic acetate hemodialysis (HDCA). Sixty four of those patients have initiated HDCA between May 1982 and December 1990 (Mean age 75.9 +/- 4.8). The etiology of renal disease was unknown in a significant number of cases. Morbility was largely due to vascular disease (both cardiac and cerebral). Main causes of death were also vascular disease and infections. Actuarial survival was 79.6% at 12 months and 46.3% after 5 years. Although HDCA is associated with a greater morbility it is the most widely used modality of treatment for chronic renal failure in Portugal and in our experience, it is an acceptable method for elderly patients.

Acetates↗
PubMed1991

Extragenic suppressors of a translation initiation defect in the cyc1 gene of Saccharomyces cerevisiae.

The cycl-362 allele contains a point mutation that generates an aberrant AUG codon upstream of the normal CYC1 translation initiation codon. Mutants containing this allele express only about 2% of normal iso-1-cytochrome c, presumably due to translation initiation at the upstream AUG, termination at a UAA sequence six codons downstream, and failure to reinitiate at the normal AUG codon two nucleotides later. Both intragenic and extragenic revertants of cycl-362, expressing elevated levels of iso-1-cytochrome c, have been isolated simply by selecting for growth on lactate medium. Here we describe an improved method for isolating and readily distinguishing cis- from trans-acting suppressors of the upstream AUG. Eight different genes, designated sua1-sua8, are represented in our current collection of extragenic suppressors; all are recessive and enhance iso-1-cytochrome c levels to 10-60% of normal. None of the sua genes is allelic to SUI2 or sui3, which encode eIF-2 alpha and eIF-2 beta, respectively, or to SUI1. Many of the suppressors exhibit pleiotropic phenotypes, including slow growth, cold (16 degrees C) and heat (37 degrees C) sensitivity. These phenotypes have been exploited to clone the SUA5, SUA7 and SUA8 genes, which are presently being characterized. The structure of cyc1-362 and the number of sua genes already uncovered suggest that the SUA genes are likely to encode factors affecting several different cellular processes, including translation initiation, mRNA stability and possibly transcription start site selection.

Alleles↗
PubMed1990

Intestinal intussusception as a presenting feature of choledochocele.

Choledochocele is a rare form of choledochal cyst [1, 2]. Usually, it manifests clinically with epigastric pain of colic type, jaundice, and/or pancreatitis. Occasionally, a palpable mass may be found. We describe two cases of intestinal intussusception as a presenting feature of choledochocele.

Adult↗
PubMed1990

Pharmacokinetics and cardiovascular dynamics of pipecuronium bromide during coronary artery surgery.

The haemodynamic effects of 200 micrograms.kg-1 pipecuronium and pancuronium were compared under etomidate/piritramide anaesthesia in 20 patients scheduled for elective coronary artery surgery. Following the completion of the haemodynamic measurements (ten minutes), anaesthesia was maintained by etomidate/sufentanil infusion. The mean changes in cardiac output were approximately -19 and -2 per cent and in heart rate -1 and +26 per cent for pipecuronium and pancuronium respectively. Plasma and urine concentrations of pipecuronium were also measured and the pharmacokinetic variables obtained indicated rapid initial decrease in plasma concentration (t1/2 = 7.6 minutes) followed by a longer terminal phase (t1/2 = 161 minutes). The central compartment volume was 102 +/- 24 ml.kg-1 and plasma clearance was 1.8 +/- 0.4 ml.kg-1 min-1. Approximately 56 per cent of the dose was recovered from the urine within 24 hours of administration and about 25 per cent of this was the metabolite, 3-desacetyl pipecuronium. High-dose pipecuronium administration under the anaesthetic regimen employed did not produce deleterious haemodynamic effects. The pharmacokinetic variables after bolus injection of pipecuronium did not deviate from those reported under normothermic conditions.

Adjuvants, Anesthesia↗
PubMed1989

Assay and characteristics of the iron binding moiety of reticulocyte endocytic vesicles.

A 59Fe assay was designed to detect an Fe(III) binding capacity in NP-40 solubilized proteins from rabbit reticulocyte endocytic vesicles. The iron binding capacity had an apparent molecular weight as determined by gel exclusion chromatography of 450,000 daltons. The iron binding moiety coincided with the major nontransferrin iron-containing material of endocytic vesicles labeled in vivo by incubation of cells with 59Fe, 125I-labeled transferrin. The material solubilized from vesicles with NP-40 exhibited two classes of saturable binding sites, one with an association constant for 59Fe-citrate of 3.63 x 10(9) M-1 and with 6.6 x 10(-12) moles of iron bound per mg protein and the other with a constant of 3.96 x 10(8) M-1 and 1.0 x 10(-12) moles of iron bound per mg protein. These affinities are sufficient to satisfy the solubility characteristics of Fe(III) at pH 5.0. Most of the 59Fe bound both in vivo and in vitro to the iron binding moiety could be displaced with 56Fe and an equivalent amount of 59Fe could subsequently be rebound in vitro. The iron binding assay was adopted to vesicle proteins separated by SDS-polyacrylamide gel electrophoresis with subsequent transfer to nitrocellulose and revealed an iron binding activity of molecular weight approximately 95,000 daltons.

Animals↗