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Biomedical subjects

A Arana

Publications and source records attributed to A Arana.

At least 19 recordsLinked to original sources
PubMed2004

Remifentanil vs fentanyl/morphine for pain and stress control during pediatric cardiac surgery.

BACKGROUND: Remifentanil is a short acting, potent synthetic opioid that does not accumulate after infusion or repeated bolus doses. It may be rapidly titrated to the requirements of individual patients. Titrated infusion of remifentanil may be able to provide potent analgesia required for pediatric cardiac surgery and obtund the stress response in theater whilst not having the persistent respiratory depression and sedation seen with longer acting opioids. METHODS: Twenty patients were randomized to receive a titrated infusion of remifentanil (0-1 microg x kg(-1) x min(-1)) or a standard dose of fentanyl (30 microg x kg(-1)) prebypass plus morphine (1 mg x kg(-1)) on rewarming. Blood samples for glucose and cortisol were taken at regular intervals from induction through bypass and into the first 24 h of postoperative intensive care. In addition to biochemical indicators of the stress response we recorded baseline hemodynamic parameters and any acute physiological events. RESULTS: Ten patients received morphine, seven received remifentanil. There were no statistically significant differences between the two treatment groups in cortisol measurements, mean arterial pressure or heart rate recordings. In the last time period the remifentanil group had a larger rise in blood glucose concentration (baseline 3.9, rise 3 mmol x l(-1)) than the fentanyl/morphine group (baseline 4.2 rise 1.9 mmol x l(-1)), CI -4.3 to -0.2. CONCLUSIONS: The only significant difference was in glucose in the postbypass time periods. Although statistically significant, this difference is insufficient evidence of increased stress in the remifentanil group. The results show that in the patients studied there was no clinically important difference between the two techniques.

Analgesics, Opioid↗
PubMed2003

Oesophageal pH monitoring in children: how is it perceived by the parents and does the technique change feeding and daily activity?

AIM: To determine whether oesophageal pH monitoring in infants induces changes in daily activity and feeding, and with the help of a questionnaire to evaluate how parents perceive pH monitoring. METHODS: The parents of 100 children, consecutively referred for oesophageal pH monitoring, were asked by one of the authors (A.A.) to respond to a standardized questionnaire immediately after the end of the procedure. Twenty questions were asked, concerning five topics: feeding (4 questions), activity (6 questions), perception of the parents (6 questions), accuracy of the provided information (3 questions), and previous experience with oesophageal pH-metry (1 question). For statistical analysis, every variable was qualified as "no change" and "change" for feeding and activity, as "positive" or "negative" regarding the perception of the test, and as "sufficient" or "insufficient" regarding the information provided. The answers to the questions were also analysed according to the result of the oesophageal pH monitoring (normal vs abnormal), and according to whether or not there was previous experience of oesophageal pH-metry in a first degree relative. RESULTS: Changes in feeding occurred in 28% of cases and changes in activity in 30%, but did not differ according to the oesophageal pH-metry result. Equally, the perception of the parents regarding the test (37% negative), the acceptability of a second pH-metry test (refusal in 52%) and previous experience with oesophageal pH-metry (positive in 25%) were not influenced by the result of the pH monitoring. Parents of infants with abnormal oesophageal pH monitoring were more frequently dissatisfied with the information about the nature of the test provided before the test and also the results than parents of infants with normal results (52% vs 19%, respectively; p < 0.05). CONCLUSION: According to the perception of the parents, pH monitoring induces changes in feeding and activity in 28% and 30%%, respectively; 63% of the parents considered pH monitoring to be well tolerated. Parents of infants with abnormal pH monitoring results need more attention.

Attitude↗
PubMed2003

Lipogenic enzyme activities in different adipose depots of Pirenaican and Holstein bulls and heifers taking into account adipocyte size.

The effects of sex, genotype, and adipose depot on lipogenic enzyme activity have been investigated in Holstein and Pirenaican bulls and heifers, taking into account differences in adipocyte size. Fifteen Pirenaican bulls and 15 heifers and 15 Holstein bulls and 13 heifers were fattened until slaughter (12 to 13 mo old and 450 to 500 kg of body weight). During the fattening period, animals had ad libitum access to commercial concentrates and straw. The 10th rib was dissected to determine the fat content. Adipocyte size and activities of the following lipogenic enzymes were determined: glycerol 3-phosphate dehydrogenase, fatty acid synthase, nicotinamide adenine dinucleotide phosphate (NADP)-malate dehydrogenase, glucose 6-phosphate dehydrogenase, and NADP-isocitrate dehydrogenase, in the omental, perirenal, subcutaneous, and intermuscular adipose depots, respectively. Because adipocyte mean cell volume varied with sex, breed, and depot, regression analyses of log(e) activity per cell and log(e) cell volume were used to compare activities per unit volume. Sex, breed and depot had no effect (P > 0.05) on the gradients of regressions, which did not differ significantly from 1. Thus, activity per unit volume did not vary with cell size. Consequently, sex, breed, and depot effects on the regression analyses were equivalent to effects on activity per unit volume. Females had greater amounts of fat in the 10th rib (P < 0.001), larger adipocytes (P < 0.001) and, in general, greater (P < 0.05) lipogenic activity per cell, even when adjusted for cell size, than males. These findings suggest that differences in adiposity between sexes are mainly due to females having a greater capacity for lipid synthesis, and hence, hypertrophy, than males. When adjusted for differences in carcass weight, Holsteins had larger adipocytes than Pirenaicans. The abdominal depots, omental and perirenal, had a greater adipocyte size (P < 0.001) and, in general, greater lipogenic enzyme activities per cell (P < 0.05) than the subcutaneous and intermuscular carcass depots. However, when activity per cell was adjusted for cell size, subcutaneous depots had greater fatty acid synthae, glucose 6-phosphate dehydrogenase, and NADP-malate dehydrogenase activities than omental and perirenal, indicating that other factors such as nutrient supply may restrict hypertrophy of carcass adipocytes.

Adipocytes↗
PubMed2001

Management of ingested foreign bodies in childhood and review of the literature.

UNLABELLED: The management of ingested foreign bodies in children is not standardised. During a 15-year period, we recorded 325 consecutive paediatric cases of accidental ingestion of foreign bodies or with symptoms suggesting oesophageal obstruction presented at the emergency department or the paediatric gastroenterology unit. The foreign bodies that had to be removed were, in decreasing order of frequency: coins, toy parts, jewels, batteries, sharp materials such as needles and pins, fish and chicken bones, and "large" amounts of food. Only 54% of the patients had transient symptoms at the moment of ingestion, such as retrosternal pain, cyanosis and dysphagia. A minority (28, 9%) of foreign bodies could be removed with a McGill forceps; 65 (20%) were removed with a magnet probe. Endoscopic removal was performed in 82 cases (25%). In the majority of cases (150, 46%) natural elimination occurred. The outcome of all patients was uneventful. CONCLUSION: Recommendations for management of children presenting with a history of suspected accidental ingestion of a foreign body for the community paediatrician are proposed.

Adolescent↗
PubMed2001

Treatment with paracetamol in infants.

BACKGROUND: Paracetamol (N-acetyl-p-amino-phenol) or acetaminophen has become the most widely used analgesic and antipyretic in children. However, there is a wide discrepancy between the extent to which paracetamol is used and the limited available pharmacological data in small infants. The purpose of this article is to present a review of the current literature regarding the use of paracetamol in neonates and infants with a particular emphasis on pharmacological issues. METHODS: A MEDLINE search (up to March 2000) was conducted to identify relevant English-language publications using paracetamol, children, infants and neonates as search terms. Additional studies were identified from bibliographies of the reviewed literature. RESULTS: Pharmacological studies on paracetamol in infants are few. Most studies have focused on the administration of one single paracetamol dose, and the problem of cumulative toxicity with repeated dosing has not been addressed. Plasma paracetamol concentration should be 10-20 mg ml(-1) to achieve antipyretic and analgesic effects. The bioavailability of the different formulations and routes of administration vary with age. Rectal absorption is slower and more erratic than the oral; however, in the very young, rectal bioavailability is higher than in older patients. Volume of distribution seems to be age-independent, whereas clearance is reduced in neonates and particularly in preterm babies. Neonates and infants are capable of forming the reactive intermediate metabolite that causes hepatocellular damage, particularly after multiple doses. They have an immature glucuronide conjugation system, but the rate constant for the sulphation metabolic pathway is larger than in older children, and this is the most important route of metabolism. CONCLUSIONS: The pharmacokinetics and pharmacodynamics of paracetamol differ substantially in neonates and infants from those in older children and adults; hence, dosing should be adjusted accordingly.

Acetaminophen↗
PubMed2001

PH monitoring in the distal and proximal esophagus in symptomatic infants.

BACKGROUND: Standard distal esophageal pH monitoring data are sometimes within normal ranges in children with clinically suspected gastroesophageal reflux disease. Therefore, the authors hypothesized that the amount of acid reflux reaching the proximal esophagus may be greater in some subgroups of patients than in healthy controls or in other subgroups of patients. METHODS: The parameters of 24-hour pH monitoring in the proximal part of the esophagus were analyzed in 120 symptomatic infants in who the reflux parameters in the lower esophagus were clearly within normal ranges (reflux index < 5.0%). The infants were classified into four patient groups: excessive regurgitation (n = 41): inconsolable crying (n = 31), apparent life-threatening event (ALTE) (n = 18), and chronic respiratory disorders (n = 30). The control group consisted also of 120 infants. The following parameters were calculated: reflux index, the number of reflux episodes, the number of reflux episodes lasting longer than 5 minutes, the duration of the longest reflux episode, and the acid clearance time (ACT, duration of reflux episodes divided by number of reflux episodes). RESULTS: The patients with chronic respiratory disorders were significantly older than the patients in the other groups and the controls. In the distal esophagus, there was no statistically significant difference between the reflux parameters. As could be expected, every parameter was statistically (paired t test, Wilcoxon signed-rank test) significantly smaller in the proximal than in the distal esophagus, except for the ACT in infants who presented with inconsolable crying. In the proximal esophagus, there was no statistically significant difference between the different patient subgroups or controls, except for the number of reflux episodes in the group with chronic respiratory disorders and the group with inconsolable crying, applying one-way analysis of variance. As determined by applying the Mann-Whitney test, the number of reflux episodes in the upper esophagus was significantly higher in the group with chronic respiratory disorders than in the other patient groups and controls. Therefore, the authors' data do not support the hypothesis that reflux reaching the proximal esophagus is a frequent cause of ALTE. However, the data may suggest that the number of reflux episodes reaching the proximal esophagus in children with chronic respiratory disorders and with distal pH monitoring data within normal ranges may be increased. Whether this finding reflects reality or a statistical coincidence, or is influenced by the older age of this patient group, needs further evaluation. CONCLUSIONS: In theory, dual simultaneous esophageal pH monitoring in the distal and proximal esophagus may increase the diagnostic accuracy of pH monitoring in infants. Our results do not support a substantial advantage of a systematic application of this new technique, especially not in infants presenting with ALTE, excessive regurgitation, or inconsolable crying. In the subgroup of patients with chronic respiratory disorders, more data are needed before conclusions can be determined and recommendations can be made.

Cohort Studies↗
PubMed2001

Efficacy and tolerability of cisapride in children.

As gastro-oesophageal reflux disease (GORD) in infants and children is a motility disorder which differs in pathophysiology and clinical course from GORD in adults, prokinetics should be considered the drug of choice in certain circumstances. Indeed, cisapride may result in improvement of feeding tolerance in premature infants. Cisapride has a better tolerability profile than a 'wait-and-see-if-improvement-comes-spontaneously' policy or the other therapeutic options available. A careful and critical review of published data suggests that cisapride may have a QTc-prolonging effect. However, provided the precautions for cisapride administration are followed, the QTc-prolonging effect remains consistently without clinically relevant adverse effects. Correct dosage and avoidance of concurrent treatment with macrolides and/or azoles are the most relevant tolerability recommendations in children. Although there is a need for a prokinetic with better efficacy, cisapride is currently the prokinetic with the best benefit-to-risk ratio available. Thus, withdrawal of cisapride would result in a significantly increased risk for severe complications in infants and children with GORD or other gastrointestinal motility disorders such as chronic intestinal pseudo-obstruction, gastroparesis and feed intolerance in premature infants.

Child↗
PubMed2000

Oesophageal pH monitoring in infants: elimination of gastric buffering does not modify reflux index.

BACKGROUND: Oesophageal pH monitoring is considered to be the gold standard investigation in the diagnosis of gastro-oesophageal reflux disease. Results of pH monitoring in regurgitating infants, however, may be within normal ranges. Therefore it was hypothesized that prolonged buffering of gastric acidity caused by milk-feeding may falsely normalize the pH data. Therefore, it may be relevant to omit the periods of gastric acid buffering in the analysis of the oesophageal pH monitoring data. METHODS: Combined gastric and oesophageal pH monitoring (Digitrapper Mark III, two-channel antimony electrode, Synectics) was performed in 90 consecutive infants, 0.5-10 months old, who were referred to the unit by outdoor paediatricians for pH measurement. The data were analysed in three different ways. The reflux index (RI), or the percentage time that the pH in the oesophagus was < 4.0, was calculated in three different ways: (i) the total duration of the investigation; (ii) excluding 90-min postprandial periods, starting from the beginning of a feeding; and (iii) excluding all periods with a gastric pH > 4.0, which are the periods of gastric buffering with a theoretical impossibility of recording an oesophageal pH < 4.0. RESULTS: The mean duration of the pHmetries was 19.20+/-2.01h (A; mean +/- 1 SD), with a RI of 5.38+/-5.39% (B; median 3.45%). If the 90-min postprandial periods were not considered, the mean duration decreased to 12.21+/-2.41h (C; P(A vs C) < 0.001), with an oesophageal RI of 6.82+/-6.57% (D; median: 4.65; P(B vs D) = NS; r (B vs D) = 0.97). If all periods with a gastric pH > 4.0 were elminated, the duration available for analysis of the data with a gastric pH < 4.0 was 12.53+/-4.00 h (E; P(A vs E) < 0.001; P(C vs E) = NS), with an oesophageal RI of 7.06+/-7.52% (F; median: 4.50; P(B vs D vs F) = NS; r(B vs F), (D vs F) = 0.96). CONCLUSION: Overall the data do not support a benefit from including periods of gastric buffering in the routine analysis of oesophageal pH monitoring data. Therefore standard oesophageal pH monitoring should be with a single electrode and should not include periods of gastric buffering.

Cisapride↗
PubMed1999

Paracetamol-induced fulminant hepatic failure in a child after 5 days of therapeutic doses.

We report the case of a two and a half year-old girl who developed fulminant hepatic failure following 5 days of regular oral ingestion of paracetamol, approximately 90 mg x kg-1 x day-1. She presented with the typical findings of hepatomegaly, encephalopathy, high ammonia levels, high transaminases, hypoglycaemia and lactic acidosis. After stabilization, she was transferred to a specialist paediatric liver failure unit and fortunately she made a full recovery with intensive medical management.

Acetaminophen↗
PubMed1999

Active monitoring of 12,760 clozapine recipients in the UK and Ireland. Beyond pharmacovigilance.

BACKGROUND: People prescribed clozapine for treatment-resistant schizophrenia have mandatory haematological monitoring through a case register for identifying reversible neutropenia. AIMS: To quantify risk factors for agranulocytosis in subjects receiving clozapine. METHOD: Data from 12,760 subjects registered to receive clozapine from January 1990 to April 1997 were analysed. Risk factors for agranulocytosis were quantified using a Cox proportional-hazards regression analysis. RESULTS: The risk for agranulocytosis in Asian subjects was 2.4 times that in Caucasians (P = 0.03). There was an age-related increase in risk of 53% per decade (P = 0.0001). CONCLUSIONS: The case register yielded valuable information for guiding research into the causes of the haematological reactions.

Adolescent↗
PubMed1997

[Epidemiology of cerebrovascular diseases in Sabaneta, Colombia (1992-1993)].

INTRODUCTION AND OBJECTIVES: In Columbia the epidemiology of cerebrovascular illness (ECV) is unknown. For this reason a study was made to determine the prevalence, incidence and annual mortality, and to identify the different types of ECV and the demographic characteristics of the population. MATERIAL AND METHODS: In the urban area of Sabaneta, Columbia 13,588 door to door interviews were carried out among the inhabitants. A cutoff study carried out between April and June 1992 showed the prevalence of ECV. One year follow-up of persons without ECV between June 1992 and June 1993, enabled the incidence and annual mortality to be evaluated. A structured interview was used to identify the demographic characteristics of the population and classify people as healthy or as possibly having ECV. The latter were examined by neurologists to confirm or rule out the presence of ECV and to determine the type of ECV involved. Of the total urban population, 76.9% agreed to participate in the study. During the follow-up year, 8.4% were lost trace of. RESULTS AND CONCLUSIONS: The prevalence of ECV was 559.3/ 100,000 inhabitants, increasing with age (15). In the 15-40 year old group, the incidence of ECV was 44 times higher in women than in men. The annual incidence rate was 88.9/100,000 inhabitants: thromboembolic disease was the most frequent. Of a total of 87 cases of ECV, 12 (13.98%) died of various causes during the year in which they were being observed. The annual mortality rate for ECV was 16.2/100,000 inhabitants, all being primary cases.

Adolescent↗
PubMed1997

[Prevalence of neurocysticercosis in individuals affected by epilepsy].

INTRODUCTION: In this investigations, was carried out a neurocysticercosis (NC) prevalence study during seven months in the Instituto Neurológico de Antioquia with the purpose of known neurocysticercosis frequency as cause of epilepsy in patients older than ten years that we attended in our institute. MATERIAL AND METHODS: Computerized tomographies (CT) were made to 503 patients, with epilepsy, 24.7% of them were CT positive for NC. Cysticercosis enzyme linked immunoelectrotransfer blot (EITB) and enzyme linked immunoabsorbent assay (ELISA) test were made to 178 patients, 19.6% were EITB positive for NC and 5% ELISA positive for NC. Results. From this result it is possible to infer that about 8% of the 503 patients with epilepsy had cysticercosis, according to EITB that is the golden assay for NC. The CT and ELISA test had 94.3% and 27.7% sensitivity, respectively, according to EITB. The specificity of the CT for NC was 49.2% and specificity for ELISA test was 100% as compared to EITB. The multivariate analysis with logistic regression allowed to establish association of positive EITB with factors such as male sex, eating pork, headaches and multiple lesions in CT. CONCLUSIONS: Prevention and education actions are necessary for the interruption of the neurocysticercosis transmission chain in order to diminish the high prevalence of epilepsy in the country and its complication and consequences.

Adult↗
PubMed1989

Blood biochemical polymorphisms as markers for genetic characteristics of wild Spanish and domestic rabbits.

Seventeen blood proteins were studied in a sample of 412 Spanish wild rabbits and in 598 domestic rabbits belonging to various breeds. The wild rabbit populations showed a high level of genetic polymorphism. Six loci were monomorphic, while the remaining ten loci were segregating for at least two alleles. Two of the loci that were polymorphic in the wild rabbits were monomorphic in the domestic ones. Wright's inbreeding coefficient in the total Spanish wild rabbit population was F = 5.66, indicating subdivision of the total population. Inbreeding coefficients, estimated by Kidd et al.'s method (Anim. Blood Grps, Biochem. Genet. 11: 21-38), differed significantly from zero, being 15.62%, in wild rabbits and 6-12% in domestic breeds, indicating consanguinity. Genetic distances between wild rabbit populations showed that factors other than geographic distance (e.g., bottlenecks, barriers such as rivers, mountains, etc.) may explain the result that a northern population forms a cluster with two central populations whereas the northeastern populations form a different cluster with another central population. Populations of the first cluster are more closely related to the captive populations than others. There are three population clusters of domestic rabbits, namely (1) New Zealand White and a hybrid combination; (2) Spanish Common, Butterfly, Burgundy, and Californian; and (3) Spanish Giant.

Animals↗
PubMed1987

Relationship between rabbit transferrin electrophoretic patterns and plasma iron concentrations.

Rabbit transferrin (Tf) was studied electrophoretically using 1141 blood samples from individuals belonging to seven populations (Spanish Common, Spanish Giant, Butterfly, Lyoné de Bourgogne, New Zealand White, Californian and New Zealand White X Californian hybrids). No Tf polymorphism was found by starch gel electrophoresis, but six patterns, differing in the presence and/or intensity of three bands ('a', anodic; 'b', intermediate; and 'c', cathodic) were observed by polyacrylamide gel electrophoresis. No genetic model could explain these patterns, since they reflect differences in plasma Tf iron content. The electrophoretic test allowed a direct observation of the relative in vivo levels of the different Tf molecular species; saturated (band 'a', Fe2Tf); semi-saturated (band 'b', Fe1Tf); and without iron (band 'c' Fe0Tf, apotransferrin). The degree of iron saturation of Tf varied among individuals and throughout the individual's life. Specifically, in pregnant females, Fe2Tf and Fe1Tf are generally observed, except in late pregnancy (from day 25 to parturition), when mainly apotransferrin is observed. Significantly, within 24 h post-partum, high levels of Fe2Tf are reached in the female's serum.

Animals↗
PubMed1987

Evidence for transferrin polymorphism in Spanish wild rabbits.

Serum samples from 412 Spanish wild rabbits were analysed by starch and polyacrylamide gel electrophoresis. Three different transferrin (Tf) phenotypes (A, AB and B) were observed by both methods. The occurrence of two codominant alleles (TfA and TfB with frequencies of 0.89 and 0.11 respectively) at an autosomal locus (Tf) was supported by the population data on genetic equilibrium. Electrophoretic mobility differences between the Tf variants A and B could not be explained by differences in sialic acid or iron contents. Each of the two Tf variants were shown to have two sialic acid residues by neuraminidase treatment. These variants had similar affinities for iron, and iron binding did not lead to the conversion of one variant into the other.

Alleles↗
PubMed1984

Influence of following Green's criteria for urinary stress incontinence surgical procedures.

A series of 161 patients with urinary stress incontinence and who underwent either Kelly urethral plication or Marshall-Marchetti procedures were reviewed in order to evaluate the usefulness of following Green's criteria in the selection of type of surgery for stress incontinence. One-year follow-up failure rate was higher in patients with type I stress incontinence (23%) than in type II stress incontinence (15.5%), and also when the choice of surgical approach did not follow Green's criteria; statistical analysis of these data showed that differences did not reach a significant level (P greater than 0.05).

Female↗