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J Ruíz

Publications and source records attributed to J Ruíz.

15 recordsLinked to original sources
PubMed2001

Effects of MA 956 superalloy and alpha-alumina particles on some markers of human osteoblastic cells in primary culture.

One of the problems associated with the modern biomaterials used in prostheses is osteolysis, which, although its exact origin is unknown, has been associated with wear particles. Osteoblasts seem to participate directly in this phenomenon. This paper investigates in vitro cellular response to the wear particles from the metal substrate and ceramic covering (alpha-alumina) of a new titanium yttrium aluminum alloy, MA 956, that has been proposed as a biomaterial because of its exceptional mechanical and electrochemical properties. The effect of different sizes (10 and 80 microm) of MA 956 and alpha-alumina particles on osteoblast function was studied in primary human bone cell cultures. Cells were harvested from trabecular bone fragments obtained during knee arthroplasty. Osteoblastic cell response to the particles was measured by assaying C-terminal type I procollagen (PICP), alkaline phosphatase, and osteocalcin secretion, with and without 1.25(OH)(2)D(3) stimulation, in the cell-conditioned medium. Both sizes of MA 956 and alpha-alumina particles decreased PICP secretion in nonstimulated osteoblastic cells, but this secretion was not affected in the cultures stimulated with 1.25(OH)(2)D(3). Only the 10 microm alpha-alumina particles inhibited alkaline phosphatase activity in 1.25(OH)(2)D(3)-stimulated and nonstimulated cultures. The rise in osteocalcin levels after 1.25(OH)(2)D(3) stimulation was lower in the presence of the 10 microm MA 956 particles than in the presence of alpha-alumina particles. Although both materials seem to have directly affected in vitro osteoblastic cell function, the increase in osteocalcin levels after 1.25(OH)(2)D(3) stimulation was lower after exposure to MA 956 particles than the increase observed after exposure to alpha-alumina particles. Therefore, it does not seem that osteocalcin stimulated bone resorption, suggesting that MA 956 would be less likely to provoke osteolysis.

Aged↗
PubMed2001

Influence of particle size in the effect of polyethylene on human osteoblastic cells.

The influence of two different sizes of polyethylene particles (< 30 and 20-200 microm) on osteoblastic function has been studied in primary human bone cell cultures. Cells were obtained from trabecular bone fragments of patients undergoing knee reconstructive surgery. On reaching confluency, cells were subcultured in three flasks: < 30 microm polyethylene particles were added to the first flask, 20-200 microm particles to the second flask and none to the third flask, which was the control. The resulting subcultures were incubated until confluence. Osteoblastic function was evaluated by assaying the secretion of osteocalcin, alkaline phosphatase, and C-terminal type I procollagen (PICP), with or without 1.25(OH)2D3 stimulation in the cell-conditioned medium. Adding < 30 microm polyethylene particles to these osteoblastic cell cultures increased the levels of osteocalcin secreted after 1,25(OH)2D3 stimulation. Treating stimulated or basal osteoblastic cultures with either polyethylene particle size did not affect alkaline phosphatase secretion. However, the addition of <30 microm polyethylene particles decreased PICP levels in the basal and stimulated cultures. A parallel series of osteoblastic cultures was treated with < 30 microm polyethylene particles and stimulated or not with 1,25(OH)2D3 to determine the effect on osteocalcin mRNA expression using RT-PCR amplification. Polyethylene particle-treated cultures had higher osteocalcin mRNA expression regardless of whether they had been stimulated with 1,25(OH)2D3 or not. We conclude that particle size affects the influence of polyethylene on osteoblastic function markers. Particles with a diameter of less than 30 microm increase osteocalcin expression and secretion.

Alkaline Phosphatase↗
PubMed2001

Liver transplantation in patients with portal vein thrombosis.

The aim of this study is to analyze the incidence, risk factors, management, and follow-up of patients with portal vein thrombosis (PVT) undergoing primary orthotopic liver transplantation (OLT). Four hundred fifteen OLTs were performed in 391 patients. In 62 patients, partial (group 1; n = 48) or complete (group 2; n = 14) PVT was found at the time of surgery. Portal flow was reestablished by venous thrombectomy. In this study, we compare 62 primary OLTs performed in patients with PVT at the time of OLT with a group of 329 primary OLTs performed in patients without PVT (group 3) and analyze the incidence of PVT, use of diagnostic methods, surgical management, and outcome. We found no significant differences among the 3 groups for length of surgery, cold and warm ischemic times, and postoperative stay in the intensive care unit. With the piggyback technique, groups 1 and 2 had greater blood losses and required more blood transfusions than group 3. The early reoperation rate was greater in group 2. The incidence of rethrombosis was 4.8% (group 1, 2%; group 2, 14.3%). Reexploration and thrombectomy (2 patients) and retransplantation (1 patient) had a 100% mortality rate. In particular, the mortality rate of patients with complete PVT with extension into the splanchnic veins is high (33%). Three-month and 4-year patient survival rates were statistically similar in the 3 groups. The presence of PVT at the time of OLT is not a contraindication for OLT. However, if PVT extends into the splanchnic veins, the outcome is guarded.

Adult↗
PubMed1998

Oral metamizol (1 g and 2 g) versus ibuprofen and placebo in the treatment of lower third molar surgery pain: randomised double-blind multi-centre study. Cooperative Study Group.

OBJECTIVE: To assess the efficacy of metamizol 1 g and 2 g in the relief of pain after surgical extraction of the lower third molar, and to compare the therapeutic effect with that of ibuprofen 600 mg or placebo. METHODS: A total of 253 patients aged between 18 years and 60 years who had undergone extraction of the lower third molar (types II-IV) under local anaesthesia, up to a maximum of 108 mg of mepivacaine, were randomly assigned to a single oral dose of a new galenic form (drinkable vials) of metamizol 1 g (n = 75), metamizol 2 g (n = 72), ibuprofen 600 mg (n = 74) or placebo (n = 32). Pain intensity was evaluated by a 100-mm visual analogue scale. To enter the study, a pain level of 50 mm or more was required. The duration of the trial was 1 h. Assessments were carried out at 15, 30 and 60 min after treatment. RESULTS: The analgesic efficacy of metamizol 2 g was significantly better than ibuprofen and placebo with regard to all evaluated parameters. The values of the pain intensity difference at 15 min, the percentage of patients with a decrease of 50% or more on the visual analogue scale at 60 min and the sum of pain intensity differences at 60 min showed metamizol 2 g to be significantly more effective than metamizol 1 g. In general, metamizol 1 g was as effective as ibuprofen 600 mg. The analgesic efficacy of placebo was significantly lower than that of all active treatments. A lower number of patients treated with metamizol 1 g (n = 1) or metamizol 2 g (n = 1) needed rescue medication than those given ibuprofen (n = 7) or placebo (n = 5). No serious adverse effects developed and none of the patients had to leave the study for this reason. CONCLUSIONS: The model of the lower third molar, for which the analgesic outcome referred to the first hour after drug administration, demonstrated that the analgesic efficacy of oral metamizol 2 g was significantly higher than that of ibuprofen 600 mg or placebo. Metamizol 1 g and ibuprofen 600 mg showed a similar therapeutic effect. All regimens were as well tolerated as placebo.

Adult↗
PubMed1997

Should patients with sleep apnoea/hypopnoea syndrome be diagnosed and managed on the basis of home sleep studies?

The purpose of this study was to analyse the validity and the economic efficiency of a portable monitor of respiratory parameters (PMRP), used in a home setting for the diagnosis of sleep apnoea/hypopnoea syndrome (SAHS). Eighty nine patients with suspected SAHS were studied in two settings: in the sleep laboratory using full-polysomnography (full-PSG); and at the patient's home using a PMRP. In the home setting, 50 patients were assisted by a technician and 39 set up the equipment themselves. SAHS (apnoea/hypopnoea index (AHI) >10 events x h(-1) by means of full-PSG) was diagnosed in 75 of the 89 patients. An acceptable agreement was obtained between the AHI measured by full-PSG and PMRP, according to the Bland and Altman method of concordance (mean bias 2.56; 95% confidence interval 3.25). Sensitivity and specificity of PMRP were adequate for diagnostic purposes; however, their values rely on the prior PMRP-AHI cut-off point selected with reference to full-PSG-AHI >10. The clinical therapeutic decision taken after PMRP agreed with that taken with full-PSG in 79 patients (89%). Although 10% of the studies with an individual set-up needed repetition, both of the domiciliary modalities (with and without a technician's intervention) were, economically, about three times more efficient than full-PSG. In conclusion, we believe that patients with a suspected sleep apnoea/hypopnoea syndrome should initially be studied in a home setting with a portable monitor of respiratory parameters, since it is a reliable method with an acceptable cost-effective profile.

Adult↗
PubMed1992

Deep venous thrombosis and the risk of pulmonary embolism. A systematic study.

The influence of several diseases and clinical conditions on the presence of pulmonary embolism (PE) in a large series of patients with deep venous thrombosis (DVT) in the lower extremities was analyzed prospectively. Lung scan findings from a series of 434 consecutive patients with DVT (with and without symptoms of PE) were studied and then correlated to five clinical variables: age, sex, elapsed time since clinical symptoms had appeared in the leg to diagnosis, degree of proximity of venous thrombus, and the presence or not of several risk factors that could have predisposed to thrombus development. According to scintigraphic findings, 164 patients were considered to have PE (asymptomatic in 76 of them), while 200 patients were classified as having only DVT. Lung scan was considered to be indeterminate for PE in 70 patients, and they were not included in the study. No differences were found in terms of age, sex, interval of time elapsed since onset of symptoms to diagnosis, or in the degree of proximity of the thrombus. However, several differences between groups were found when comparing the presence or absence of several predisposing factors for thrombosis: DVT developing in immobilized patients was associated with a significantly lower incidence of PE as compared with nonimmobilized patients (p = 0.005). Conversely, patients with a history of venous thromboembolism (VTE) had a significantly higher rate of embolism (31/51 vs 133/313; p = 0.01). On logistic regression analysis, a history of VTE showed a statistically significant association with more than a twofold higher risk of having PE for patients with such an antecedent. Our findings suggest that different pathophysiologic pathways could perhaps explain differences in embolic potential.

Causality↗
PubMed1991

Platelet count and venous thromboembolism. A useful test for suspected pulmonary embolism.

We have previously reported that patients with deep vein thrombosis (DVT) and scintigraphic evidence of pulmonary embolism (PE) had a fall in platelet count, as compared with their levels before thrombosis had developed. Otherwise, no changes were found in DVT patients without embolism. We recently conducted a prospective study with a larger series of patients and studied platelet count behavior in 189 consecutive patients with acute venous thromboembolism (VTE) in whom a baseline blood cell count was available (obtained before thromboembolism developed). We found no significant differences in baseline platelet counts between groups. However, at the time of VTE diagnosis the analysis of variance demonstrated that mean platelet count was significantly higher in patients without embolism as compared with PE patients (p less than 0.001). On the other hand, no differences were found between patients with silent PE and those with clinically obvious PE. When patients with postoperative VTE and those with nonpostoperative VTE were analyzed separately, mean platelet count increased only in postoperative DVT patients without embolism (p less than 0.001). In the absence of a previous intervention, DVT did not produce any change in platelet count, while PE significantly reduced platelet number (p less than 0.008). In DVT patients without respiratory symptoms of embolism, we suggest that a lung scan should be performed when platelet count is lower than baseline value. For patients with a higher count, the probability of finding PE is very low, and scintigraphy is not cost-effective.

Adolescent↗
PubMed1985

Physicochemical properties of a beta-lactamase from Streptomyces UCSM-104.

A purified beta-lactamase from Streptomyces UCSM-104 shows the presence of three subforms when stained for protein and/or for activity after polyacrylamide gel electrophoresis or after electrofocusing. The pI values of the three subforms were 5.45, 5.30 and 5.10, respectively. The respective electrophoretic mobilities were 4.6 X 10(-5), 5.2 X 10(-5) and 5.9 X 10(-5)m2/sV. Relative molecular mass of 14,900 was determined. The amino acid composition was established. Cysteine was not detected. A fairly high proline content (8.3%) differentiates this enzyme from other beta-lactamases. Lysine was the only N-terminal amino acid detected after dansylation. The possible origin of the subforms is discussed.

Amino Acids↗
PubMed1980

[Diagnosis of viral hepatitis type A by radioimmunoassay (author's transl)].

In the present work radioimmunoassay technique detecting antibodies have been used to diagnose viral hepatitis type A. Twenty-nine patients with sporadic acute hepatitis were studied. All of the cases were negative to surface antigen of viral hepatitis type B. Blood samples were obtained at the onset of clinical picture and on subsequent weeks. Antibody levels (anti-hepatitis virus A) showed a significant increase between the second and the sixth week in 21 cases (72.4 percent). An increased antibody titer in a single determination, however, is not sufficient for the diagnosis of hepatitis virus A, since antibodies against such virus are present in a large percentage of the normal population. At least two augmented titers in consecutive samples are necessary to diagnose viral hepatitis type A.

Adolescent↗
PubMedDate not supplied

[The endoscopic treatment of pancreatic pseudocyst].

We define in this paper different modalities of endoscopic treatment as well as the criteria for this procedure. Endoscopic drainage were done through cystoenterostomy and nasocystic drainage and enterocystic prosthesis plus sphincterostomy of the principal pancreatic and biliary duct, in all patients, but only in eleven of them we implanted the prosthesis in both ducts. The complication was bleeding, in two patients (16.7%) and they were treated with endoscopic inyectotherapy.

Acute Disease↗
PubMedDate not supplied

[Laparoscopic cholecystectomy. Report of the first 1300 cases carried out by a multidisciplinary team].

Nowadays, the laparoscopic cholecystectomy has been accepted as the more effective and safe procedure for the treatment of symptomatic gallstones. The present issue shows the initial result in the management of 1300 patients undergoing laparoscopic cholecystectomy, by a surgical team integrated by experienced endoscopist and surgeons. The diagnosis and treatment of common duct stones were performed preoperatively in 35 patients (2.7%). The ERCP, with endoscopic sphincterotomy and stone extraction was performed in all cases. The overall conversion rate to open cholecystectomy was 0.8%. The technical difficulty to identify the structures was the more frequent cause of conversion. On the other hand, the complication rate was 2.5%, there were no bile duct injuries, and the mortality associated was 0.15%. The 92.8% of our patients was discharged within 24 hours of surgery. We conclude that the medical team, integrated by endoscopist and surgeons, offer to patient an organic and sequential management of their illness; moreover, this was decisive to obtain lower rate of complications, mortality and conversion.

Adolescent↗