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Biomedical subjects

P Serrano

Publications and source records attributed to P Serrano.

At least 37 records · Page 2Linked to original sources
PubMed2002

Helicobacter pylori increases the risk of upper gastrointestinal bleeding in patients taking low-dose aspirin.

AIM: To evaluate the role of Helicobacter pylori infection and other clinical factors in the risk of upper gastrointestinal bleeding in patients taking low-dose aspirin. SUBJECTS AND METHODS: A case-control study was carried out of consecutive current users of low-dose aspirin admitted because of upper gastrointestinal bleeding. Within a cohort of 695 patients with upper gastrointestinal bleeding, 98 patients had taken low-dose aspirin and no other non-steroidal anti-inflammatory drug. Controls were 147 low-dose aspirin users without upper gastrointestinal bleeding of similar age, sex and extent of aspirin use as cases. H. pylori infection was determined by CagA/VacA serology and 13C-urea breath test in all cases and controls. Adjusted odds ratios (OR) are provided. RESULTS: H. pylori infection was identified as an independent risk factor of upper gastrointestinal bleeding in this population (OR, 4.7; 95% confidence interval (95% CI), 2.0-10.9), but the presence of CagA-positive serology was not. Other risk factors identified were a previous ulcer history (OR, 15.2; 95% CI, 3.8-60.1), alcohol use (OR, 4.2; 95% CI, 1.7-10.4) and use of calcium channel blockers (OR, 2.54; 95% CI, 1.25-5.14). Antisecretory therapy (OR, 0.1; 95% CI, 0.02-0.3) and nitrovasodilators (OR, 0.2; 95% CI, 0.1-0.6) decreased the risk of bleeding. CONCLUSIONS: H. pylori infection is a risk factor for upper gastrointestinal bleeding in low-dose aspirin users, which might have therapeutic implications in high-risk patients.

Aged↗
PubMed2002

Risk of upper gastrointestinal bleeding in patients taking low-dose aspirin for the prevention of cardiovascular diseases.

BACKGROUND: Most patients with vascular-occlusive diseases benefit from low-dose aspirin (75-325 mg/day). However, they have an increased risk of upper gastrointestinal bleeding (UGIB). AIMS: To analyse the incidence and factors influencing the occurrence of UGIB in patients taking low-dose aspirin for the prevention of cardiovascular diseases outside clinical trials. METHODS: We studied 903 consecutive patients discharged on low-dose aspirin from the Cardiology Department of a general hospital. Data were collected from medical charts and structured telephone interviews. RESULTS: Forty-one patients (4.5%) presented with UGIB requiring hospitalization during follow-up (45 +/- 22 months). The incidence of UGIB was uniform during follow-up (1.2 UGIB per 100 patient years). Multivariate analysis showed that a history of peptic ulcer or UGIB [risk ratio: 3.1, 95% CI: (1.5-6.5)] and aspirin dose (per 100 mg/day) [1.8 (1.5-2.9)] was associated with higher risk of UGIB. On the other hand, antisecretory [0.22 (0.07-0.75)] and nitrovasodilator drugs [0.73 (0.55-0.96)] were associated with a decreased risk. CONCLUSIONS: Cardiovascular patients on long-term low-dose aspirin have a stable risk of major UGIB, which is higher than published controlled clinical trials. Antisecretory and nitrovasodilator drugs protect from UGIB, whereas previous peptic ulcer or UGIB and higher doses of aspirin increase the risk.

Aged↗
PubMed2002

Flow velocity and predictors of a suboptimal coronary flow velocity reserve after coronary balloon angioplasty.

AIMS: This study was conducted to analyse flow velocity parameters and predictors of a suboptimal coronary flow reserve (<2.5) following balloon angioplasty. METHODS: Two hundred and twenty-five patients underwent sequential intracoronary Doppler as part of the DEBATE I study. Of these, 183, with complete angiography and Doppler at the 6-month follow-up, were included. Univariate and multivariate logistic analysis was performed to identify independent predictors of post-procedural suboptimal coronary flow reserve, defined as coronary flow reserve <2.5. RESULTS: Forty-eight per cent (n=88) of the patients achieved a suboptimal coronary flow reserve. These patients had higher baseline velocities (cm.s(-1)) before balloon angioplasty (18+/-9 vs 14+/-6, P=0.004), after balloon angioplasty (22+/-11 vs 14+/-5, P<0.001) and at follow-up (19+/-9 vs 16+/-6, P=0.011) than the optimal coronary flow reserve group. Although the suboptimal group had lower hyperaemic velocities (cm.s(-1)) after balloon angioplasty than the optimal group (42+/-17 vs 49+/-16, P=0.008), these velocities became similar at follow-up. Increasing age (odds ratio, OR 1.071, P=0.0002), female gender (OR 2.52, P=0.014) and increasing pre-procedural baseline average peak velocities (OR 1.056, P<0.001) were found to be independent predictors of a suboptimal coronary flow reserve following balloon angioplasty. CONCLUSION: A suboptimal coronary flow reserve was associated with (1) a chronically elevated baseline average peak velocity (2) a transient deficit in the hyperaemic average peak velocity (3) the elderly, and female gender.

Angioplasty, Balloon↗
PubMed2002

Location of zinc and 65Zn in spinal ganglia of the rat.

Following the works of Velazquez et al. (1999), Jo-Seung et al. (2000), Wang et al. (2001), Danscher et al. (2001) and the criteria of Zinc-containing neurons established by Frederickson et al.(2000), we have found the presence and localisation of Zinc in the neurons of the dorsal root ganglia of Wistar rat, by using Timm's thecnique and by studying the autoradiographic uptake of 65Zn. The agreement between the results of both techniques allows us to classify these spinal ganglion neurons as Zinc-containing neurons and also, to confirm some of the results of Velazquez et al. (1999).

Animals↗
PubMed2001

In vitro study of FFR, QCA, and IVUS for the assessment of optimal stent deployment.

We tested whether fractional flow reserve (FFR) discriminates between suboptimally and optimally deployed stents. Latex tubes (diameter solidus in circle = 4 mm) with diameter stenosis 40% (n = 3), 50% (n = 3) and 60% (n = 3) were tested in a pulsatile flow system, using water. Measurements were done at baseline (n = 9; FFR/QCA) and after suboptimal (SOD; 3-mm balloon at 8 atm) and optimal (OD; 4 mm balloon at 16 atm) deployment of a 35-mm stent (n = 6; FFR/QCA/IVUS). Varying Q from 150 to 50 ml/min increased FFR by 2-7%. Conversely, at 100 ml/min, FFR increased by only 0.8% from SOD to OD (P < 0.05). Extrapolating data to blood flow, the gain in FFR from SOD to OD is less than 5% for Q = 100 ml/min, while FFR may increase by 15-20% by changes in blood flow from 50 to 150 ml/min. We conclude that IVUS and QCA are more appropriate for the assessment of optimal stent deployment.

Blood Flow Velocity↗
PubMed2001

Application of strengths, weaknesses, opportunities and threats analysis in the development of a health technology assessment program.

There has been recent interest in developing a health technology assessment (HTA) function in Estonia. A group of individuals knowledgeable about HTA in Canada, Germany, Romania and Spain, along with representatives of the University of Tartu, Estonia, was convened by the Institute of Health Economics in Edmonton, Canada, to consider options for such a function. In a one-day workshop strengths, weaknesses, opportunities and threats (SWOT) analyses of HTA were conducted, first at a 'global' level, and then of the Estonian situation. The 'global' SWOT analysis yielded a large number of items that pertain to institutionalized HTA in a generic sense, i.e. not based on any individual HTA agency. The 'Estonian' SWOT yielded a subset of items, which pertain to development of HTA in that country. Ten actionable steps were then developed on the basis of this subset, which could be used to initiate the creation of an HTA body in Estonia.

Delivery of Health Care↗
PubMed2001

Hernia surgery for the third millennium. Does classical herniorraphy still play a role?

The steadily increasing use of prosthetic grafts in hernia repairs can be said to play down the classical approach for repairing groin hernia. We retrospectively report on 894 patients operated on for groin hernia at our out-patient surgery clinic from June 1992 to May 1998. Herniorraphy was widely performed (96.3%). The recurrence rate was of 1.6% (overall). For patients younger than 45 yr with no systemic concurrent disease, as few as 0.1% relapsed after a 58-month average follow-up. According to our results, ambulatory herniorraphy can provide an excellent degree of efficiency in selected young patients suffering from indirect unilateral primary groin hernia. Likewise, we regard the prosthetic repair as the gold standard technique in those patients with a weakened posterior inguinal wall.

Journal Article↗
PubMed2001

Rhabdomyolysis, acute renal failure, and death after monensin ingestion.

We report a case of human monensin intoxication; to our knowledge, this is the first reported case in the medical literature. The patient took a dose of monensin three times higher than a dose considered lethal for cattle and developed a clinical picture similar to that reported in veterinary medicine. There was an early and extremely severe rhabdomyolysis followed by acute renal failure, heart failure, and death. The main changes observed at autopsy were extensive skeletal muscle necrosis, complement deposition at the myocardial level, pulmonary edema, and acute tubular damage.

Acute Kidney Injury↗
PubMed2001

Indirect evidence for a role of a subpopulation of activated neutrophils in the remodelling process after percutaneous coronary intervention.

AIM: Leukocytes have been implicated in restenosis following percutaneous transluminal coronary angioplasty. We investigated the link between the activated status of circulating neutrophils and restenosis after angioplasty. METHODS AND RESULTS: The population of 108 patients with single, de novo lesions located in native coronary arteries were treated with elective balloon angioplasty (n=44) or stenting (n=64). Pre-, post-procedure and 6-month follow-up, angiograms were analysed by an independent core laboratory. Blood samples were collected immediately before treatment and the antigen CD66, which is specifically expressed by activated neutrophils, was measured. Overall, the average expression of CD66 was 6.4+/-3.6 of mean fluorescence intensity. In the stepwise linear regression model, which included biological, clinical and angiographic variables, absolute gain showed a direct association (P<0.001) with relative late loss (relative late loss=absolute late loss/pre-procedure reference diameter), whereas CD66 expression was inversely associated with relative late loss (P=0.004). CD66 expression also showed an inverse association with relative late loss in the balloon angioplasty treated patients (P=0.002, beta=-0.49). In the stent subgroup, only reference vessel diameter and acute gain were independent predictors of relative late loss. CONCLUSION: Our results confirm the beneficial role of activated neutrophils pre-procedure in the restenotic process after balloon angioplasty. The lack of a relationship between CD66 expression by neutrophils and relative late loss after stenting suggests that this leukocyte may be involved in the remodelling process.

Angioplasty, Balloon, Coronary↗
PubMed2001

Acetylcholinesterase-positive and paraformaldehyde-induced-fluorescence-positive innervation in the upper eyelid of the sheep (Ovis aries).

This is the first study which describes the innervation of some eyelid structures, such as the glands of Moll and the glands of Zeiss. It is also the first to investigate the innervation pattern of the eyelid as a whole. We have studied the acetylcholinesterase-positive and paraformaldehyde-induced-fluorescence-positive (FIF+) innervation pattern of the different structures that constitute the upper eyelid of the sheep. There is widespread acetylcholinesterase-positive innervation in the epithelium, but not such an abundant FIF+ innervation. Both types of innervation are represented in the connective tissue by trunks or fibers that are distributed towards the different structures immersed within them. In the glands of Zeiss, cholinesterase-positive innervation is much more widespread than FIF innervation. On the contrary, the glands of Moll present denser FIF+ innervation than acetylcholinesterase-positive innervation. The Meibomian glands and the lachrymal glands show a rich acetylcholinesterase-positive and FIF+ innervation. Eyelid muscle innervation is mainly acetylcholinesterase-positive. In the conjunctive membrane there is no acetylcholinesterase-positive innervation, and only scarce FIF+ fibers can be demonstrated.

Acetylcholinesterase↗
PubMed2001

Enteric plexus and interstitial cells of Cajal: interrelationship in the stomach of Podarcis hispanica (Reptilia). An ultrastructural study.

The ultrastructure organization of the stomach enteric plexus was examined in the lizard Podarcis hispanica. The ganglions of the myenteric plexus present a low number of nerve cell bodies with a peculiar nucleus, which occasionally establish direct contacts with cells of the circular muscle layer. Glial cells are smaller than the neurones, and their nucleus is very electron-dense. They surround the axons that constitute the fibres of the myenteric plexus. Four main types of axon profile are described in a morphological consideration of the vesicle population. In the interstice of the circular muscle layer we describe two types of interstitial cells that, due to their ultrastructural characteristics, may be equivalent to the interstitial cells of Cajal which have been described in mammalians. These cells shows parallel distribution to the stomach nerve plexuses, establishing close contacts with them through their long cytoplasmic prolongations. By means of small gap-like unions, they contact both each other and the smooth muscle cells near them. We describe a submucous plexus, where neuronal bodies are scattered among bundles of nervous fibres, some of which are myelinated. A mucous plexus with isolated neurones is located in the lamina propria. Axonal varicosities containing vesicles contact with the cells of the mucous. Interconnected interstitial cells may also be found in this plexus.

Animals↗
PubMed2000

Three-dimensional intravascular ultrasound assessment of noninjured edges of beta-irradiated coronary segments.

BACKGROUND: The "edge effect," late lumen loss at the margins of the treated segment, has become an important issue in the field of coronary brachytherapy. The aim of the present study was to assess the edge effect in noninjured margins adjacent to the irradiated segments after catheter-based intracoronary beta-irradiation. METHODS AND RESULTS: Fifty-three vessels were assessed by means of 3-dimensional intravascular ultrasound after the procedure and at 6- to 8-month follow-up. Fourteen vessels (placebo group) did not receive radiation (sham source), whereas 39 vessels were irradiated. In the irradiated group, 48 edges (5 mm in length) were identified as noninjured, whereas 18 noninjured edges were selected in the placebo group. We compared the volumetric intravascular ultrasound measurements of the noninjured edges of the irradiated vessels with the fully irradiated nonstented segments (IRS, n=27) (26-mm segments received the prescribed 100% isodose) and the noninjured edges of the vessels of the placebo patients. The lumen decreased (6 mm(3)) in the noninjured edges of the irradiated vessels at follow-up (P:=0. 001). We observed a similar increase in plaque volume in all segments: noninjured edges of the irradiated group (19.6%), noninjured edges of the placebo group (21.5%), and IRS (21.0%). The total vessel volume increased in the IRS in the 3 groups. No edge segment was subject to repeat revascularization. CONCLUSIONS: The edge effect occurs in the noninjured margins of radiation source train in both irradiated and placebo patients. Thus, low-dose radiation may not play an important role in this phenomenon, whereas nonmeasurable device injury may be considered a plausible alternative explanation.

Angioplasty, Balloon↗
PubMed2000

Nitrovasodilators, low-dose aspirin, other nonsteroidal antiinflammatory drugs, and the risk of upper gastrointestinal bleeding.

UNLABELLED: BACKGROUND The relation between medications that release nitric oxide, such as nitroglycerin and other nitrovasodilators, and upper gastrointestinal bleeding is uncertain. In animals, these medications reduce the gastric damage induced by nonsteroidal antiinflammatory drugs. Nitric oxide, however, inhibits platelet aggregation and may contribute to bleeding from an ulcer. METHODS: We performed a case-control study to determine the risk of bleeding in patients taking nitrovasodilators, low-dose aspirin, or other nonsteroidal antiinflammatory drugs. The case group was made up of 1122 consecutive patients admitted to one of four hospitals with bleeding from a peptic lesion. The 2231 control subjects were 1109 patients hospitalized for other reasons and 1122 outpatients from the same geographic area. RESULTS: In the week before admission, 520 (46.3 percent) of the patients with bleeding had taken a nonsteroidal antiinflammatory drug other than low-dose aspirin, 120 (10.7 percent) had taken low-dose aspirin (< or = 300 mg per day), 60 (5.3 percent) a nitrovasodilator, and 135 (12.0 percent) an antisecretory agent such as a histamine H2-receptor antagonist or a proton-pump inhibitor. In multivariate models that adjusted for age, sex, and clinical risk factors, the use of a nonsteroidal antiinflammatory drug other than low-dose aspirin was independently associated with an increased risk of bleeding from a peptic ulcer (odds ratio, 7.4; 95 percent confidence interval, 4.5 to 12.0), as was the use of low-dose aspirin alone (odds ratio, 2.4; 95 percent confidence interval, 1.8 to 3.3). The use of a nitrovasodilator was associated with a decreased risk of bleeding (odds ratio, 0.6; 95 percent confidence interval, 0.4 to 0.9), as was antisecretory therapy (odds ratio, 0.6; 95 percent confidence interval, 0.4 to 0.8). In patients taking any type of nonsteroidai antiinflammatory drug, the use of a nitrovasodilator or antisecretory therapy was independently associated with a decreased risk of bleeding. CONCLUSIONS: The use of nitrovasodilator drugs is independently associated with a decreased risk of upper gastrointestinal bleeding.

Aged↗
PubMed2000

Enhanced learning after genetic overexpression of a brain growth protein.

Ramón y Cajal proposed 100 years ago that memory formation requires the growth of nerve cell processes. One-half century later, Hebb suggested that growth of presynaptic axons and postsynaptic dendrites consequent to coactivity in these synaptic elements was essential for such information storage. In the past 25 years, candidate growth genes have been implicated in learning processes, but it has not been demonstrated that they in fact enhance them. Here, we show that genetic overexpression of the growth-associated protein GAP-43, the axonal protein kinase C substrate, dramatically enhanced learning and long-term potentiation in transgenic mice. If the overexpressed GAP-43 was mutated by a Ser --> Ala substitution to preclude its phosphorylation by protein kinase C, then no learning enhancement was found. These findings provide evidence that a growth-related gene regulates learning and memory and suggest an unheralded target, the GAP-43 phosphorylation site, for enhancing cognitive ability.

Animals↗
PubMed2000

Distinct NMDA receptor subpopulations contribute to long-term potentiation and long-term depression induction.

Long-term potentiation (LTP) and long-term depression (LTD) are persistent modifications of synaptic strength that have been implicated in learning, memory, and neuronal development. Despite their opposing effects, both forms of plasticity can be triggered by the activation of NMDA receptors. One mechanism proposed for this bidirectional response is that the specific patterns of afferent stimulation producing LTP and LTD activate to different degrees a uniform receptor population. A second possibility is that these patterns activate separate receptor subpopulations composed of different NMDA receptor (NR) subunits. To test this hypothesis we examined the inhibition of LTP and LTD by a series of competitive NMDA receptor antagonists that varied in their affinities for NR2A/B and NR2C/D subunits. The potency for the inhibition of LTP compared with inhibition of LTD varied widely among the agents. Antagonists with higher affinity for NR2A/B subunits relative to NRC/D subunits showed more potent inhibition of LTP than of LTD. D-3-(2-carboxypiperazine-4-yl)-1-propenyl-1-phosphonic acid, which binds to NR2A/B with very high affinity relative to NR2C/D, showed an approximately 1000-fold higher potency for LTP than for LTD. These results show that distinct subpopulations of NMDA receptors characterized by different NR2 subunits contribute to the induction mechanisms of potentiation and depression.

Aging↗
PubMed2000

Geographic miss: a cause of treatment failure in radio-oncology applied to intracoronary radiation therapy.

BACKGROUND: A recognized limitation of endovascular beta-radiation therapy is the development of new stenosis at the edges of the irradiated area. The combination of injury and low-dose radiation may be the precursor of this phenomenon. We translated the radio-oncological concept of "geographic miss" to define cases in which the radiation source did not fully cover the injured area. The aims of the study were to determine the incidence and causes of geographic miss and evaluate the impact of this inadequate treatment on the outcome of patients treated with intracoronary beta-radiation. METHODS AND RESULTS: We analyzed 50 consecutive patients treated with beta-radiation after percutaneous coronary intervention. The prescribed dose ranged between 12 and 20 Gy at 2 mm from the source axis. By means of quantitative coronary angiography, the irradiated segment (IRS) and both edges were studied before and after intervention and at 6-month follow-up. Edges that were injured during the procedure constituted the geographic miss edges. Twenty-two edges were injured during the intervention, mainly because of procedural complications that extended the treatment beyond the margins of the IRS. Late loss was significantly higher in geographic miss edges than in IRSs and uninjured edges (0.84+/-0.6 versus 0.15+/-0.4 and 0.09+/-0.4 mm, respectively; P<0.0001). Similarly, restenosis rate was significantly higher in the injured edges (10% within IRS, 40.9% in geographic miss edges, and 1.9% in uninjured edges; P<0.001). CONCLUSIONS: These data support the hypothesis that the combination of injury and low-dose beta-radiation induces deleterious outcome.

Angioplasty, Balloon, Coronary↗
PubMed2000

Vineberg revisited. Long-term survival more than two decades after direct surgical myocardial revascularization.

A 65-year old patient was referred to our institution for a diagnostic catheterization. 23 years before, a direct surgical myocardial procedure using the Vineberg technique was performed. Currently, the angiogram shows patent left and right internal mammary arteries implanted directly into the myocardium and connecting with the native circulation through collaterals. As the native coronary artery tree shows very severe three vessel disease, it is hypothesized that the major contribution of myocardial perfusion comes from the implanted vessels. This is the first case to show a long-term success of the Vineberg operation, with persistence of myocardial perfusion through newly formed vasculature.

Aged↗