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Biomedical subjects

A Serra

Publications and source records attributed to A Serra.

At least 109 records · Page 6Linked to original sources
PubMed1996

Endothelial dysfunction of the non-infarct related, angiographically normal, coronary artery in patients with an acute myocardial infarction.

BACKGROUND: Patients with acute myocardial infarction and single-vessel disease may have early atherosclerosis in other angiographically normal coronary arteries. METHODS: Coronary endothelial responses were analysed in 20 non-diabetic patients with an acute myocardial infarction and one-vessel disease. In an angiographically normal, non-infarct related, coronary artery serial acetylcholine doses of 10(-7) M, 10(-6) M, 10(-5) M and 10(-4) M and nitroglycerin 40 micrograms were infused over 3 min. The responses of the coronary vessel were measured with quantitative angiography. Coronary blood flow was also measured with a Doppler catheter in 11 of the 20 patients. RESULTS: Four patients showed a trend towards vasodilation during acetylcholine infusion in the proximal and distal segments: from 2.49 +/- 0.23 mm to 2.95 +/- 0.42 mm and 2.43 +/- 0.56 mm to 2.81 +/- 0.66 mm, respectively. Coronary vascular resistance decreased to 57 +/- 4% (P = 0.03). The other 16 patients presented vasoconstriction in the proximal and distal segments: 2.61 +/- 0.75 mm to 2.03 +/- 0.65 mm (P = 0.0001), and 2.40 +/- 0.58 to 1.81 +/- 0.56 mm (P = 0.0036), respectively. Nitroglycerin caused vasodilation in the proximal (2.69 +/- 0.61 mm, P = 0.017, ANOVA) and distal segments (2.48 +/- 0.45 mm, P = 0.009, ANOVA). Coronary vascular resistance increased to 141 +/- 43% (P = 0.03) over the basal value in this group of patients. CONCLUSION: Endothelial dysfunction of the epicardial and resistance vessels was found in angiographically normal coronary arteries of patients with one-vessel disease in 75% of this population.

Adult↗
PubMed1996

Optimizing sodium balance in hemodialysis.

this paper develops and tests a mathematical model for Na+ kinetics applied to standard hemodialysis. The volume of distribution of exchangeable Na+, dialyzer surface area, blood and dialysis fluid flow rate, target weight loss, treatment duration and the Na+ diffusibility constant are taken into account. The model is used to compute the optimal hour by hour dialysis fluid Na+ concentration required to achieve the prescribed end-dialysis natremia and maintain a constant end-dialysis body Na+ pool, while providing a nearly uniform removal of Na+ over dialysis. The model was preliminary tested on 10 consecutive dialyses in a single patient using special dialyzer which generates a part of ultrafiltrate uncontaminated by dialysate.

Aged↗
PubMed1996

High incidence of chronic GVHD after primary allogeneic peripheral blood stem cell transplantation in patients with hematologic malignancies.

To assess feasibility and potential advantages of PBSC allograft, we transplanted nine patients (age 20-47 years) with advanced or poor-risk hematologic malignancies. These included eight HLA-identical sibling transplants and one partially matched. Cells were collected from donors by apheresis after rh-G-CSF 10-16 micrograms/kg/day for 4-5 days, and stored at 4 degrees C until infusion. Patients were conditioned with busulfan 16 mg/kg and cyclophosphamide 200 mg/kg, and received GVHD prophylaxis with CSA-MTX. The graft consisted of PBSC alone, with a median of 101.2 (range 28-254.2) x 10(4)/kg CFU-GM, 6.84 (range 4.57-15.9) x 10(6)/kg CD34+ cells and 2.5 (range 1.2-6) x 10(8)/kg CD3+ cells. An ANC > 0.5 x 10(9)/1 occurred on (median) day 13 range 11-17), and a platelet count > 50 x 10(9)/l on (median) day 15 (range 12-29) post graft. One patient died of ARDS on day 13, the others are alive 96-485 (median 245) days from the graft. Two patients have relapsed, one of them with isolated CNS involvement. Acute GVHD (grade I-II) occurred in three patients and severe chronic GVHD in six patients, with no relationship to CSA withdrawal. This unexpected incidence of chronic GVHD might be linked to the high number of CD3+ cells in the graft, contributing to a favourable GVL effect.

Adult↗
PubMed1996

Histochemical demonstration of acetylcholinesterase activity in human Meibomian glands.

The distribution of acetylcholinesterase activity in human Meibomian glands was evaluated using enzyme-histochemical methods. The butyrylcholinesterase (BuChE) inhibitor, tetraisopropyl pyrophosphoramide (iso-OMPA), was used to localize acetylcholinesterase (AChE) activity, the AChE inhibitor, 1,5-bis (4-allyldimethylammoniumphenyl) pentan-3-one dibromide (BW284c51), was used to localize BuChE activity, and eserine was used to inhibit all cholinesterase activity in control incubations; the appropriate specific inhibitors for competing enzymic activities were added to the incubation medium. At the light microscopic level, acetylcholinesterase reaction product appeared as cytoplasmic brown deposits, often crystalline. A very dense accumulation of AChE-positive nerve fibers was seen in the form of a network around the acinar and the ductal tissue of the glands. No discrete nerve endings were observed, whereas a strong reaction was elicited in some fibers in close association with blood vessels. These observations suggest that the cholinergic system is involved in the regulation of the Meibomian glands secretory function.

Acetylcholinesterase↗
PubMed1996

[Proposal of new formulas for three-point urea kinetics, compared with traditional kinetics and direct dialysis quantification].

Classical urea kinetic model (UKM) has been followed by several proposals to determine dialysis adequacy either by direct quantification (DDQ), either by simplified two-points formulas (pre- and post-dialysis BUN), or by mUKM, a modified three-point algorithm (pre-post and pre-next dialysis), where urea distribution volume is input to obtain clearance and urea generation rate. Our new formulas (mUKM2) are derived from urea mass balance, and avoid iterative calculation: their results are similar to those obtained by UKM and mUKM when the standard post-dialysis BUN value is employed. On the contrary, when the equilibrated net-rebound value (Cpwnr) is employed their results are very close to the reference DDQ model: however the new approach is simpler and more practical, to measure dialysis dose taking account of the urea rebound phenomenon.

Female↗
PubMed1996

[The history and evolution of the surgical techniques in rhinoplasty].

Few other forms of surgery embody the authentic, full essence of surgery as does rhinoplasty, where functional results are joined to meet one's innermost expectations. the present work reviews the main stages in the course of the evolution of the philosophy and surgical techniques adopted to resolve both the functional and esthetic problems of the nose. This provides a broad view of the issues every surgeon has had to deal with in this regard. The history of rhinoplasty once more teaches us that the evolution of a discipline hinges around the daily renewal of one's preparation through study, observation and insights.

History, 15th Century↗
PubMed1996

[Registry of activities at the Section of Hemodynamics and Interventional Cardiology in 1995].

The results of the Spanish Registry of Hemodynamic and Interventional Cardiology are presented. Eighty hospitals have collaborated, which represent 100% of the cardiac catheterization laboratories. Seventy-two of which performed cardiac catheterization in adults and eight laboratories which exclusively performed pediatric cardiac catheterizations. We have studied 57,773 diagnostic procedures which were performed, which represents an increase of 11% from 1994. In addition, 12,359 angioplasties were performed, representing an increase of 18%. This represents 312 PTCAs per million people. PTCA success (91%) and global complications (3.2%) were similar to those of 1994. There was an increase in stent implantation: 3,418 procedures with 4,321 stents. This represents 1.26 stent per procedure. Sixty-four per cent of them were done electively and with a marked reduction in complications rate: subacute thrombosis, 1.6%, MI, 1.8% and a mortality of 1.1%. The number of mitral valvuloplasties decreases 16% and the pediatric interventional procedures (464) were similar to those of last year.

Adult↗
PubMed1996

[Identification of a variant D(IVa) with anti-D in serum].

The first D(IVa) variant described so far in Spain is presented. This variant was identified, by means of a commercial monoclonal antibodies panel, in a RhD positive patient with anti-D in her serum. Differential diagnosis is discussed and the clinical relevance of identifying these variants is commented.

Antibodies, Monoclonal↗
PubMed1995

Cross-linking of alpha 4 beta 1 and alpha 5 beta 1 fibronectin receptors enhances natural killer cell cytotoxic activity.

Cell/extracellular matrix interactions mediated by integrins regulate differentiation, migration, and effector functions of immune system components. Human NK cells express alpha 4 beta 1 and alpha 5 beta 1 integrins, which mediate their binding to fibronectin (FN). We have investigated the ability of FN and its beta 1 integrin receptors to modulate NK cytotoxicity. Our data show that the presence of immobilized FN significantly augments the spontaneous cytotoxic activity of in vitro cultured human NK cells against several NK-susceptible, but not NK-resistant, target cells; Ab-dependent cytotoxicity against Ab-coated P815 target cells and the redirected lysis of anti-CD16 hybridomas are also enhanced in the presence of FN. Solid-phase-bound anti-human beta 1, or its F(ab')2 fragment, anti-alpha 4 and anti-alpha 5 mAbs, all consistently enhance Ab-dependent cytotoxicity against Ab-coated murine target cells. The 120-kDa (alpha 5 beta 1-binding), but not the 40-kDa (alpha 4 beta 1-binding), FN fragment fully reproduced the enhancing effect observed with the entire molecule. Our data also demonstrate that alpha 4 beta 1 and alpha 5 beta 1 cross-linking on NK cells induces an increase of intracellular Ca2+ concentration that is abrogated by EGTA, thus suggesting that the capacity to mobilize Ca2+ is involved in the coactivating role of alpha 4 beta 1 and alpha 5 beta 1 FN receptors in the cytotoxic functions of NK cells.

Antibodies, Monoclonal↗
PubMed1995

The double spermatogenesis in Scutigera coleoptrata (Myriapoda, Chilopoda): macro- and microspermatocyte growth.

In Scutigera coleoptrata, double spermatogenesis (macro and micro germinal cells) was reinvestigated by means of both image analysis and electron microscopy. Image analysis of the two cell-lines showed no differences in DNA content between the two types of spermatogenesis. The only difference found, with the exception of the size and the related number of organelles, was that in the macro-cell line the chromatin was well dispersed and not condensed, which is the opposite of what was observed in the micro-cell line. It is assumed that the level of activity related to this condensation process is at the origin of the two pathways of development.

Animals↗
PubMed1995

Mitral valve rupture following percutaneous mitral commissurotomy: existence of predictive factors.

The purpose of this study was to describe the mechanism and determine predictive factors of mitral valve rupture requiring valve replacement following percutaneous mitral commissurotomy. Of the 350 consecutive patients treated by balloon mitral commissurotomy, the procedure was not completed in 16, and 11 developed acute severe mitral regurgitation requiring valve replacement: seven cases of anterior leaflet rupture, three cases of posterior leaflet rupture and one case of anterior chordal surface. These 27 group I patients were compared to the remaining 323 (group II) in whom the procedure was completed. The 11 excised valves were evaluated by an experienced pathologist. Eight of the 11 patients had an echocardiographic score < 8 (mean score 6.5 +/- 1), no valvular calcification at X-ray and double balloon percutaneous mitral commissurotomy. Microscopy in six patients showed focal fibrous thickening at the site of the rupture but no calcification. One patient developed severe mitral regurgitation due to chordal rupture with an Inoue balloon. The two remaining patients had an echo score of ten and valve calcification on X-ray. Microscopy revealed severe homogeneous chronic rheumatic mitral disease. In one of these two patients, leaflet rupture was related to an 'oversized balloon' (2 x 19 mm + 15 mm). Statistical analysis showed only echo score differences between the two groups (6.9 +/- 1.4 in group I vs 8.2 +/- 1.6 in group II, P < 0.02).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1995

Involvement of the cyclin-dependent kinase-4 inhibitor (CDKN2) gene in the pathogenesis of lymphoid blast crisis of chronic myelogenous leukaemia.

Recent data suggest that homozygous deletion of the cyclin-dependent kinase 4 inhibitor gene (CDKN2), a putative tumour suppressor gene located on chromosome 9p21, represents a common genetic event in human cancer. As the molecular basis of the evolution of chronic myelogenous leukaemia (CML) into blast crisis remains largely unknown, we decided to investigate if the occurrence of similar deletions could represent one of the mechanisms underlying the disease progression. Whereas none of 22 chronic phase CML cases examined showed alterations, we found that 3/17 total blast crisis examined (18%) showed a homozygous deletion of the CDKN2 gene. The deletions were restricted to cases of lymphoid blast crisis, being present in 3/8 (40%) of the lymphoid and in none of the nine myeloid cases examined. The fact that the chronic phase DNA obtained at diagnosis in one of the cases lacks the homozygous deletion observed in blast crisis, suggests that the final deletion event took place concomitantly with the progression of the disease. Furthermore, the analysis of polymorphic regions on chromosome 9p21 flanking at both sides the CDKN2 gene, showed that deletions at 9p21 differ between cases and are characterized by a wide range of extensions. A concomitant search for a possible involvement of the p53 tumour suppressor gene in the same series of patients showed mutations of the gene and loss of heterozygosity at 17p only in myeloid blast crisis, suggesting the presence of distinct molecular pathways in the pathogenesis of lymphoid and myeloid blast crisis.

Base Sequence↗
PubMed1995

Evaluation of the API-campy system in the biochemical identification of hippurate negative campylobacter strains isolated from faeces.

The aim was to evaluate the efficacy of the API-Campy system in the biochemical identification of 62 hippurate negative campylobacter strains isolated from the faeces. The strains were identified manually as 34 nalidixic acid susceptible C coli (NAS), 20 nalidixic acid resistant C coli (NAR), and eight C lari. The 34 strains of NAS C coli were identified as such by the API-Campy system. Of the 20 strains of NAR C coli, 15 (75%) were correctly identified by the commercial system. None of the five NAR C coli strains which were also erythromycin resistant was identified as such by the system. The eight C lari strains could not be identified by the API-Campy system because the bionumber obtained does not exist in the database of the computer system. The API-Campy system could be very useful for the identification of NAS C coli. However, failure to allow for a higher percentage of resistance to nalidixic acid in this species does not permit good identification of NAR strains. More important discrepancies are observed in C lari strains. In order to improve the identification of NAR C coli and C lari stains, it is advisable to include, or recommend as complementary, the indoxyl acetate hydrolysis test.

Bacterial Typing Techniques↗