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Biomedical subjects

A Montes

Publications and source records attributed to A Montes.

At least 19 recordsLinked to original sources
PubMed2004

Treatment of malignant superior vena cava syndrome by endovascular stent insertion. Experience on 52 patients with lung cancer.

BACKGROUND: Superior vena cava syndrome (SVCS) is a frequent presentation of malignancies involving the mediastinum and can seriously compromise treatment options and prognosis. Stenting of superior vena cava is a well-known but not so commonly used technique to alleviate this syndrome. PATIENTS AND METHODS: Between August 1993 and December 2000 we performed 52 stenting procedures in patients affected by non-small cell lung cancer (NSCLC). RESULTS: Phlebographic resolution of the obstruction was achieved in 100% of cases with symptomatic and subjective improvement in more than 80%. One major complication was observed due to bleeding during anticoagulation. Re-obstruction of the stent occurred in only 17% of the cases, the majority due to disease progression. Improvement of the syndrome allowed hydration necessary for full dose platinum treatment when indicated in patients affected by lung cancer. CONCLUSIONS: Stenting of the superior vena cava syndrome is a safe and effective procedure achieving a rapid alleviation of symptoms in almost all patients, and allowing for full dose treatment in lung cancer patients. This procedure could change the traditional poorer prognosis attributed to non-small cell lung cancer patients presenting with this syndrome.

Adult↗
PubMed2003

Simple method to determine the size of the laryngeal mask airway in children.

BACKGROUND AND OBJECTIVE: The size of the laryngeal mask airway in children is determined by the patient's weight. However, in some instances an alternative method may be wanted. The aim was to search for a new method that would be easy to perform at the bedside. METHODS: The size of the laryngeal mask airway was determined in 183 children by choosing the laryngeal mask that best matched the combined widths of the patient's index, middle and ring fingers. The results were compared with the standard method recommended by the manufacturer's weight-related guidelines. The patients were classified in different groups depending on the laryngeal mask airway sizes determined by both methods. A kappa coefficient evaluated the agreement between both techniques. RESULTS: The kappa coefficient was 0.81, showing an 'excellent agreement' between both methods. The size was the same for both methods in 142 children (78%). The disagreement between both techniques was only of one size in the remaining 41 patients (22%). In such patients, the weight was a borderline value that would indicate a change in the size of the laryngeal mask airway using the classic method. CONCLUSIONS: This new approach is of valid and practical use in children, particularly as an alternative in those situations where the patient's weight is unknown, such as in emergency situations or in those borderline instances where an alternative measurement would be useful.

Adolescent↗
PubMed2002

Effects of haemolysis, lipaemia, bilirubinaemia and fibrinogen on protein electropherogram of canine samples analysed by capillary zone electrophoresis.

The possible interference of haemolysis, lipaemia, bilirubinaemia and fibrinogen on capillary zone electrophoresis of canine samples were studied. Solutions of haemoglobin, lipid and bilirubin were prepared and mixed with serum aliquots to make up samples containing different concentrations of the putative interferent substance. In addition, samples of serum and plasma were assayed to assess the influence of fibrinogen. Haemolysis and lipids produced a change in electropherogram morphology giving an interference peak located in the beta-2 region when haemoglobin was increased, and in the alpha-2 region when lipids were increased. A rise in concentration of these interferents caused an increase in the beta and alpha-2 fractions respectively, and a decrease in the other fractions. Bilirubin did not alter morphology but gave an increase in the albumin and alpha-1 and a decrease in the alpha-2 and beta-2 fractions. No differences were found between serum and plasma samples, and fibrinogen did not produce any additional peak.

Animals↗
PubMed2002

[Cardiorespiratory arrest: a rare complication of subdural block].

We report a case of accidental subdural block after epidural anesthesia that manifested as cardiac arrest due to extensive spinal blockade 20 minutes after administration of 50 mg of 0.5% bupivacaine. The event resolved without sequelae. Subdural placement of the catheter was verified by computed axial tomography contrast medium. Clinical signs of subdural block are highly variable, extensive neural block being among the possible rare presentations, with latency ranging from a few minutes to as long as 30. Recent electron microscope observations with new methods for fixing and preparing tissues suggest that the dubdural space does not exist naturally, but rather forms artificially within a low-resistance cell plane composed of neurothelial cells, as a result of trauma or the injection of a local anesthetic. The characteristics of the space depend, therefore, on factors that come together at the site. These data explain the great variability in the clinical manifestations of a subdural block. The case of cardiopulmonary arrest we report is rare in the literature.

Aged↗
PubMed2001

Lovastatin induces apoptosis of spontaneously immortalized rat brain neuroblasts: involvement of nonsterol isoprenoid biosynthesis inhibition.

We have examined the effects of lovastatin and pravastatin (competitive HMG-CoA reductase inhibitors) on the growth and survival of rat brain neuroblasts. Lovastatin, but not pravastatin, suppressed cell growth by inducing apoptosis of neuroblasts in a dose- and time-dependent manner. Apoptosis was accompanied by a decrease in both Bcl-2 and Bcl-xL protein levels, suggesting that changes in the expression of these genes may contribute to apoptosis following lovastatin treatment. Lovastatin treatment was also associated with decreased prenylation of both Ras and Rho A proteins whereas Rac 1 geranylgeranylation was not affected. Lovastatin effects were fully prevented by mevalonate. The present data suggest that lovastatin induces apoptosis of rat brain neuroblasts by its capacity to decrease the prenylation of specific proteins involved in signal transduction pathways that control growth and survival of neuronal cells.

Animals↗
PubMed2001

Management of postoperative pain in Spain.

BACKGROUND: The management of postoperative pain is suboptimal world-wide. This survey was carried out to determine current management in Spanish hospitals. METHODS: Spanish hospitals were divided into two groups: <200 beds (n=346) and >200 beds (n=186). A structured questionnaire was mailed to the heads of the anaesthesiology services of a random sample of 150 of hospitals of <200 beds, and all larger hospitals. RESULTS: Only 19% of hospitals with <200 beds responded and further analysis of this group was not possible; 53% of hospitals with >200 beds responded. In this sample (>200 beds), 45% of patients receive information on postoperative pain, given by the anaesthesiologist in 78% of cases. Over 70% of the hospitals do not have an acute pain unit and responsibility for postoperative pain lies with the anaesthesiology team in 71%, with the surgical team in 40% and with nursing in 33%, with an overlap of pain caretakers. Pain is measured on the surgical wards in 36% and recorded with the vital signs in 34%. On post-anaesthetic recovery wards, analgesia is most frequently given by intravenous (83%), epidural (78%) and continuous intravenous (66%) administration. On surgical wards, the most frequent routes that are available are epidural (72%), intravenous (69%) and intramuscular (58%). Only 28% of the anaesthesiology services are satisfied with the pain treatment carried out in their hospitals. No significant differences on postoperative pain management were observed between teaching and non-teaching institutions. CONCLUSION: The survey shows that the management of postoperative pain in hospitals with >200 beds in Spain is suboptimal and this is associated with dissatisfaction among many anaesthesiologists.

Data Collection↗
PubMed2001

The price of cigarettes in the European Union.

BACKGROUND: A major factor influencing tobacco use is its price. Fiscal policies on tobacco are a key ingredient of any comprehensive control strategy, as they can be used to raise prices. The European Union (EU) developed directives to ensure some harmonisation of the fiscal pressure on tobacco across its member states. OBJECTIVES: To provide a simple comparison of tobacco prices in the EU, adjusting for the purchasing power of each currency. DESIGN: For price comparisons, a 20 units pack of Marlboro was the reference product, and data refer to April 2000. Purchasing power parities (PPP) for each member state currency have been compiled. These are currency conversion rates, which convert to a common currency and equalise the purchasing power of different currencies. MAIN OUTCOME MEASURES: Nominal prices of a Marlboro pack for each member state, and a price index, estimated taking as reference the EU mean. Adjusted prices and an adjusted price index have been estimated using PPP. RESULTS: Nominal prices show wide variation, with the cheapest pack in Portugal (59) and the most expensive in the UK (196); the range of variation is three-fold. However, PPP adjusted prices reveal a different distribution. In three countries adjusted prices are outliers, but all other countries make two clusters, one around the average EU index of 100, the other around a lower value of 85. CONCLUSIONS: These results suggest that fiscal harmonisation policies in the EU do not have an even effect at reducing availability by its impact in price.

European Union↗
PubMed2000

Use of intravenous patient-controlled analgesia for the documentation of synergy between tramadol and metamizol.

The quantification of the synergistic interactions (beneficial and adverse) of analgesic drug combinations in humans has been elusive. We propose a new procedure based on analgesic requirements (i.v.-PCA) and pain intensity (VAS-PI). One hundred and one post-hysterectomy patients received at the time of analgesia request (TAR) tramadol (100 mg, group I) or metamizol (1.2 g, group II) alone, or combined in 1:1 (III), 1:0.3 (IV) or 1:3 ratio (V). After 15 min, they received the same treatment by PCA. VAS-PI, analgesic consumption and adverse effects were assessed at TAR, and periodically for 24 h. Data were analysed using interaction indexes and isobolograms. All treatments produced equivalent VAS-PI, per cent efficacy and adverse effects. When drugs were combined in a 1:1 ratio, synergy was present for the analgesic and adverse effects; all other treatments were additive.

Adult↗
PubMed1999

Morphology and amplitude values of the P and T waves in the electrocardiograms of Spanish-bred horses of different ages.

This investigation was undertaken to determine values of electrocardiographic parameters in Spanish-bred horses at different stages of growth. The study was carried out on 179 healthy Spanish-bred (Andalusian) horses (98 females and 81 males), which were aged between 1 month and 17 years. The ECGs showed P waves of different configurations. The bifid shape deflection of the P wave was generally more frequent than the simple one in animals from 6 months of age. The first component of bifid P waves (P1) did not vary in a statistically significant way with increasing age, showing a mean value of 0.105 mV. The amplitudes of the P2 (the second component of the bifid P waves) and simple P waves showed statistically significant differences between the age groups. The highest values were found in animals up to 3 months and over 2 years of age. Several configurations of the T wave were observed in the different age groups: a negative shape was generally present for the youngest animals (foals up to 2 years old); the biphasic (/+) pattern became more frequent in animals 3 and 4 years old. In adult horses the positive configuration was the most frequent. No statistically significant differences according to age were found for the amplitude values of the different T-wave configurations.

Aging↗
PubMed1998

A randomized trial of maintenance interferon following high-dose chemotherapy in multiple myeloma: long-term follow-up results.

High-dose chemotherapy (melphalan) with autologous marrow stem cell support (AMSCS) results in high response rates in multiple myeloma (MM), with up to 50% of patients achieving complete remission. However, these remissions are generally not durable. As the cytokine interferon alpha has been shown to prolong partial response following conventional chemotherapy, this trial was conducted to evaluate its role following high-dose chemotherapy. 85 patients were randomly assigned to maintenance treatment with interferon alpha, 3 x 10(6) units/m2 subcutaneously three times weekly until relapse or no further treatment following recovery from high-dose chemotherapy (melphalan 140-200 mg/m2 or busulphan 16 mg/kg) combined with AMSCS. At 5.8 years following the accrual of the last patient in this trial, 38 patients had died, 17 in the interferon arm and 21 in the control arm. The median progression-free survival (PFS) in the 42 patients randomized to interferon alpha was 46 months versus 27 months in the controls. Both overall survival and PFS, which were highly significant at median follow-up of 52 months, have now ceased to be significant, because most patients have ultimately succumbed to their disease. Interferon was tolerated by the majority of patients with very good compliance. Toxicity consisted mainly of flu-like symptoms and malaise which were usually self-limiting. The results of such a pilot study should be carefully interpreted and the benefits of interferon should be confirmed in larger multicentre studies in the setting of minimal residual disease following autologous transplantation.

Adult↗
PubMed1998

Modifications of the form and amplitude of the electrocardiographic QRS complex during growth in the Spanish-bred Horse.

Configuration and amplitude values of the QRS complex of the electrocardiogram were studied with standard Einthoven leads in 173 healthy Spanish-bred (Andalusian) horses, aged between 1 month and 17 years. Animals which were 1 month old had a predominantly negative QRS complex, whereas a predominantly positive complex direction was found in the rest of the animals. Statistically significant variations were found for the Q-wave and QRS main vector between the different age groups, with highest values for the Q-wave and most negative values for the direction of the QRS main vector in animals up to 2 months of age. The effect of age on the form and amplitude values of the QRS complex could be related to the changes in size and position of the heart in the thorax during growth. This study provides standard electrocardiographic values for the Andalusian horse at different ages.

Aging↗
PubMed1997

Lovastatin decreases prolactin and growth hormone gene expression in GH4C1 cells through a cAMP dependent mechanism.

The heterotrimeric G protein Gs couples several surface ligand receptors to cAMP production, as well as to both growth hormone (GH) and prolactin (PRL) gene expression in pituitary and GH cells. It has been shown that constitutively active alpha s stimulates transient expression of both PRL- and GH- chloramphenicol acetyl transferase (CAT) constructions, which indicates that both the PRL and GH promoter regions are under the influence of signal pathways mediated by alpha s. We have previously shown that the cholesterol lowering drug lovastatin decreases both the amount of G alpha s subunit in the membrane and the adenylyl cyclase activity in GH4C1 cells. Thus, we tried to verify whether that decrease in alpha s levels could affect PRL and GH secretion, as well as the expression of PRL- and GH-CAT constructions. Since the regulation of these two genes is dependent on the pituitary specific transcription factor Pit-1, the effect of lovastatin on the expression of Pit-1-CAT constructions was also studied. Our results show that lovastatin decreased the basal expression of these three cAMP-responsive genes in GH4C1 cells, being partially reversed by the addition of mevalonate to the culture medium. This effect of lovastatin on the promoter activities of the transfected constructions was also observed in PRL and GH secretion to the medium, suggesting that this drug produces similar changes in the endogenous promoters of both hormones. Moreover, the presence of lovastatin did not prevent the response to the cAMP activator forskolin, indicating that the main effect of this drug could be exerted through upstream adenylyl cyclase. In conclusion, our data indicate that lovastatin decreases the basal expression of Pit-1 and consequently of both GH and PRL genes through a mechanism probably mediated by the decrease of G alpha s levels in the cell membrane. Taken together, these results suggest that the activity of membrane heterotrimeric G proteins regulates the basal transcription of specific cellular genes in GH4C1 cells. Moreover the effects of lovastatin may be taken into account in the study of constitutively endocrine disorders associated with an increased secretion of either PRL or GH.

Animals↗
PubMed1997

Effect of mevalonate availability on the association of G-protein alpha-subunits with the plasma membrane in GH4C1 cells.

We show that the levels and activity of the alpha-subunits of Gs and Gi proteins in plasma membrane of GH4C1 cells are regulated by the availability of mevalonate (MVA), and not by changes in cholesterol cell content. Changes in the levels of MVA, induced by modulation of 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase, determine the amount of both membrane-bound G alpha-subunits, which correlated with the activity of their effector adenylyl cyclase. Lipoprotein deficient serum (LPDS) decreases cholesterol content and increases both HMG-CoA reductase activity and G alpha-subunits in the membrane. Cholesterol and 25-hydroxycholesterol (25-HC) each repress HMG-CoA reductase and diminish G alpha-subunit levels. However, while cholesterol cell content is also decreased by 25-HC, exogenous cholesterol increases it. In addition, the decrease of both G alpha-subunits is reversed by the presence of MVA. This regulation appears to be mediated by nonsterol products generated from MVA. We assume that the first is the prenylation of the gamma-subunits, since the attachment of G alpha-subunits to the membrane is dependent on this modification. However, as neither of our treatments completely abolished protein prenylation, we conclude that another MVA derivative is required in addition to prenyl residues to the presence and activity of alpha-subunits in the membrane.

Blood↗