[Electron microscopy study of an androgen-forming adrenocortical adenoma].
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17-Hydroxycorticosteroids↗
Biomedical subjects
R Calvo
Publications and source records attributed to R Calvo.
Sulfamethazine absorption and disposition: effect of surgical procedures for gastroduodenal ulcers.
This study was designed to determine whether the surgical procedures for gastroduodenal ulcers influence sulfamethazine (SMZ) absorption and disposition. Prior to and on the average 79 days after surgery, eight patients received 10 mg kg-1 of sulfamethazine orally. Blood samples were obtained at regular intervals over 24 h and urine was collected for 48 h. Vagotomy with pyloroplasty or with gastrojejunostomy had no effect on SMZ kinetics. Vagotomy with partial gastrectomy decreased the SMZ plasma peak concentrations from 43.9 +/- 7.1 (mean +/- SEM) to 17.2 +/- 5.2 micrograms ml-1 (p less than 0.05) and increased the time required to reach this peak from 2.6 +/- 0.8 to 9.8 +/- 2.8 h (p less than 0.05). SMZ rate constant of absorption decreased only slightly (1.22 +/- 0.45 to 0.24 +/- 0.07 h-1) and SMZ bioavailability was not affected at all. In two (out of four) patients, SMZ volume of distribution and total body clearance increased, as reflected in the 41 per cent decrease in the mean area under the SMZ plasma concentration-time curve. No changes were detected in SMZ protein binding. Computer simulations indicated that in some subjects SMZ plasma concentrations at steady state could be 76 per cent lower following vagotomy with partial gastrectomy than before surgery. It was concluded that vagotomy and antrectomy with a gastroduodenostomy or Billroth I reconstruction decreased the rate of SMZ absorption and only in some subjects increased the SMZ volume of distribution and rate of elimination. The possible mechanisms involved in these reported kinetic changes are discussed.
Adult↗
Paracetamol metabolism in two ethnically different Spanish populations.
The 24 h urinary excretion of paracetamol and its metabolites following a single oral dose of 1.5 g was compared in two ethnically different Spanish populations: 39 volunteers from the Basque country and 32 from Alicante. The urinary concentrations of unchanged paracetamol and its glucuronide, sulphate, cysteine, and mercapturic acid conjugates were determined by high-performance liquid chromatography. Statistically significant differences in the urinary excretion of unchanged paracetamol and the fractional urinary recovery of each conjugate between subjects from Alicante and subjects from the Basque country were not found. In both populations, an inverse relationship between glucuronide and sulphate conjugation following a bimodal frequency distribution pattern was found. In contrast to paracetamol oxidation, intersubject variation in paracetamol conjugation was negligible. The urinary excretion of unchanged paracetamol was higher in smokers than in nonsmokers. As compared with other studies, the urinary excretion of oxidation-derived paracetamol metabolites in both Spanish populations was intermediate and significantly different than that found in Caucasians from Scotland and West Africans (Ghana). This may determine a susceptibility to paracetamol hepatotoxicity following overdosage in the Spanish population.
Acetaminophen↗
Plasma protein binding of penbutolol in pregnancy.
Penbutolol is a not cardioselective beta-adrenergic blocking drug; it is lipid soluble and differs in its protein binding from the other members of its group because shows linkage to alpha 1-glycoprotein, with no detectable binding to albumin. AAG levels change during pregnancy and so the binding of [3H]-penbutolol was compared in 11 pregnant patients and in 10 healthy women. Binding was obtained by ultrafiltration and measurement of the free fraction by scintillation spectrometry. The free penbutolol fraction was significantly higher in the pregnant women than in the controls (6.06 +/- 0.34 compared with 3.55 +/- 0.29, P less than 0.001). The AAG levels in the pregnant women were significantly lower (0.40 +/- 0.03 g/l) than in the controls (0.77 +/- 0.06 g/l) (P less than 0.001) which showed a significant correlation with the bound/free penbutolol ratio (r = 0.61, P less than 0.005). On the other hand there was no significant correlation with the extent of penbutolol's protein binding even though the albumin levels were lower in the pregnant women (2.83 +/- 0.17 compared with 4.86 +/- 0.17; P less than 0.001). Penbutolol's nK1a for AAG was lower in pregnant women, and this suggests that the fall in AAG levels is not the only factor involved in the reduced binding of penbutolol in pregnancy.
Adult↗
Differential effect of cancer on the serum protein binding to mianserin and imipramine.
Protein binding of mianserin and imipramine in vitro was determined in sera from 10 patients with cancer and from 28 drug-free normal subjects. alpha 1-acid glycoprotein (AAG) concentrations ranged from 0.91 +/- 0.04 g/l in control subjects to 2.17 +/- 0.18 g/l in cancer patients. Albumin concentrations ranged from 55.80 +/- 1.68 g/l in control subjects to 39.71 +/- 4.40 g/l, respectively. Serum samples containing concentrations of 100 ng/ml for mianserin and 500 ng/ml for imipramine were ultrafiltered and the free concentration were measured with scintillation spectrophotometer. The mean free percentage of mianserin was significantly less in patients with cancer (8.70 +/- 0.29% in patients vs 14.30 +/- 0.50% in control subjects P < 0.001). A multiple regression analysis revealed a significant contribution of plasma AAG (r2 = 0.56, P < 0.01), but not of albumin to the overall variability in mianserin binding. No correlation was observed between protein binding of imipramine and AAG concentrations in serum of cancer patients. No significant changes were observed for protein binding of imipramine in cancer patients as compared with control subjects. Our results suggest that for antidepressant (AD) drugs, of which the binding depends on AAG, variability in protein binding could be expected in cancer patients. Thus, in cancer therapy, changes in analgesic doses could be necessary with this kind of antidepressant drug.
Adolescent↗
[Accident and emergency department inappropriate utilization. An evaluation with explicit criteria].
BACKGROUND: Several studies have shown a growth in the number of visits to accident and emergency (A&E) hospital departments with a high proportion of inappropriate utilization. Methods to identify improper use based on implicit criteria limit the comparisons between hospitals. The aim of this study is to know the proportion of inappropriate attendance's in an A&E department and their associated factors, using a method with objective criteria. METHODS: An instrument based on diagnosis-independent explicit criteria was used to identify inappropriate visits in a random sample of 1845 14-year-old greater patients attended to A&E medical services, and the factors associated with improper demand were analysed. RESULTS: The proportion of inappropriate attendance's was of the 26,8% (495/1. 845). The unadjusted analysis show that the smaller age, absence of comorbidity, spontaneous visit and some diagnostic groups (diseases of the skin, muscle-skeletal, mental, and bad defined symptoms) were associated to a greater proportion of improper use. Upon adjusting the variables through logistics regression, the age, associated pathology, the spontaneous attendance's and diagnostic groups, maintained the association with improper use, but other variables as woman gender, and night hours were also associated to inappropriate utilization. CONCLUSIONS: At least the fourth part of the attendance's in the A&E medical services do not require urgent attention. Inappropriate utilization is associated to characteristic of the patient and the attended process.
Adult↗
Biowaste effects on soil and native plants in a semiarid ecosystem.
Many soils of the Mediterranean region with a semiarid climate are subjected to progressive degradation as a result of water erosion. Biosolids and municipal solid wastes (MSW) were surface-applied once at three rates (40, 80, and 120 Mg ha(-1)) to different plots in a degraded semiarid ecosystem. The study was conducted to determine the effects of such applications on soil chemical properties and native vegetation over a three-year period. Soil N, P, and K initially increased with increasing biowaste application rates, but then decreased over time. Levels of Zn and Cu were higher in MSW than biosolid-treated plots, and increased in both years after application. Concentrations of soil Cd, Pb, Ni, and Cr did not change as a result of biowaste amendment in the study period. The growth of native plants was enhanced by the addition of biowastes. Total plant canopy and plant biomass increased significantly and remained higher in all treatments than in the control plot over the three-year period. The species richness of native plants decreased with increasing biowaste rates. Differences in the development of native plant communities between treatments were observed, and were more remarkable three years after biowaste application. Tissue N, P, K, Zn, and Cu levels increased with the biowaste application rate, but concentrations of tissue Pb, Cd, Ni, and Cr did not increase significantly. Biowastes applied at the rate of 80 Mg ha(-1) gave rise to the most favorable soil and native vegetation results while avoiding environmental risks.
Agriculture↗
Plasma protein binding of etomidate in patients with renal failure or hepatic cirrhosis.
The influence of renal failure and of hepatic cirrhosis on the plasma protein binding of etomidate, an intravenous anaesthetic agent of basic nature, has been investigated. The percentage of free etomidate in plasma containing 1 microgram/ml was markedly increased in patients with renal failure and in patients with hepatic cirrhosis, when compared with a group of healthy volunteers (43.4 +/- 2.9% and 44.2 +/- 2.1 versus 24.9 +/- 1.4%). This decrease in binding correlated inversely with serum albumin levels in both conditions (r = -0.88 and r = 0.72, respectively) but a slight decrease in the amount bound per mole of albumin was also apparent in both types of disease.
Adult↗
Unilateral angiofibromas. An oligosymptomatic and segmentary form of tuberous sclerosis.
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Angiofibroma↗
Proposal of a dimensional model of personality disorders.
During recent years there has been a growing interest on several aspects regarding psychopathology in general and particularly with personality disorders, such as dual psychopathology, comorbidity and dimensional models. Going from the Eysenck's three-factor model to the Fiske's five-factor one, from the Cloninger's psychobiological model to the Millon's biosocial one, a wide variety of personality analysis models, as well as dimensions to which the different personality disorders should be anchored, have been proposed. Here, we propose a dimensional model for personality disorders based on DSM-IV criteria, which are cognitive style (field dependence-independence), prevalent emotion (anger-fear), interpersonal style (submissiveness-dominance), and impulse control (impulsiveness-compulsiveness). We consider that these dimensions are related to different levels of cerebral complexity, assuming that evolution operates under the redundancy principle. Based on these dimensions, a bimodal model in which antisocial personality (high field dependence, anger, dominance, and impulsiveness) and schizotypal personality (low field dependence, fear, submissiveness, and compulsiveness) would be anchored in each extreme is proposed. Between these two extremes, the rest of personality disorders, such as borderline, paranoid, narcissist, histrionic, dependent, passive-aggressive, avoidant, obsessive-compulsive, paranoid, and schizoid, would be anchored.
Humans↗
[Short-term prophylaxis with aztreonam in gastrointestinal surgery].
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Adult↗
[Resistance to pancuronium caused by theophylline and forskolin].
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Animals↗
[Characterization of propofol binding to plasma proteins and possible interactions].
OBJECTIVES: a) To study the binding of propofol to proteins in plasma samples from healthy volunteers and in solutions of albumin and alpha 1-acid glycoprotein (AGA); b) to describe the nature of the bond and possible interactions with other substances that are potential displacers: salicylate, phenylbutazone, sulfisoxazole, tolbutamide, sodium valproate, sodium oleate and penbutolol; c) to assess the effect of propofol on the binding of specific markers and possible binding sites in the following proteins: 14C-warfarin, 3H-diazepam, 3H-midazolam, 3H-imidazole, 3H-penbutolol and 3H-morphine. MATERIAL AND METHODS: The free fraction was obtained in all samples by ultrafiltration and measurement of the free concentration of propofol by liquid chromatography and of the markers by scintillation spectrometry. RESULTS: The free fraction of propofol in plasma was 0.98 +/- 0.12% and binding was not saturable. Albumin seems to play an important role (95% bound), whereas the participation of AGA was low (54% bound). Propofol did not affect the binding of any of the markers studied. Nor did the presence of other drugs at therapeutic plasma concentrations affect the binding of propofol. CONCLUSIONS: The binding of propofol to plasma proteins seems unlikely to cause drug interactions in clinical practice.
Blood Proteins↗
Influence of several surgical techniques in peptic ulcer disease on the oral kinetic of a basic drug.
The effect of gastric surgery on the absorption of a basic drug propranolol was studied in 11 patients. 80 mg of propranolol were administered orally before and after surgery. Irrespective of the surgical technique, there was only a significant decrease in the absorption constant Ka (1.10 +/- 0.14 vs 0.72 +/- 0.09) (p < 0.05), indicating a delay in the gastrointestinal absorption, which agreed with the delay in the urine excretion in the first six hours after surgery (6.8 +/- 0.8 vs 1.7 +/- 0.4) (p < 0.001). Patients with vagotomy but without gastric resection showed a significant increase in the time of attainment of peak concentration tmax (2.4 +/- 0.2 vs 3.2 +/- 0.3), and decrease in Ka (1.5 +/- 0.12 vs 0.73 +/- 0.17) (p < 0.05), indicating also a delay in the gastrointestinal absorption, that is not seen in patients with partial gastric resection. We conclude that vagotomy with gastric resection does not modify the absorption of propranolol, and vagotomy without resection delays its absorption but does not decrease it.
Administration, Oral↗
[Allografts in extensive spinal arthrodesis].
Surgery of spinal deformities and vertebral tumors often requires extensive arthrodesis, with the difficulty of obtaining sufficient autogenous bone graft (particularly in children and cases of paralytic deformities) and the necessity of a second incision, thus lengthening the operation and eventual increase of the morbidity. We present 52 patients who suffered from vertebral tumours, fractures or spinal deformities and underwent spinal arthrodesis surgery. Femoral head allografts were used as cancellous bone graft to add to the amount obtained from the arthrodesis bed itself (posterior structures). In three occasions, femoral head grafts shaped as a strut were also used as intersomatic bone graft, being implanted via a costotansversectomy. The only complication was the appearance of seromas of spontaneous resorption in the first 15 cases (thereafter repeated cleaning of the bone graft avoided this problem). In our experience, bone grafts facilitate the carrying out of shorter surgical operations but can also avoid having to recourse the further incisions without reducing the possibility of obtaining a successful arthrodesis.
Adolescent↗
[Psychiatric disorders and cognitive deterioration in Friedreich ataxia].
The present study was designed with the aim of examining the presence of psychiatric diagnosis and intellectual impairment in a sample of patients with Friedreich's ataxia. A consecutive sample of 21 patients presenting with Friedreich's Ataxia were evaluated by means of a neuropsychiatric interview. Only one patient was diagnosed as mentally retarded. Out of the 15 patients of the sample who were evaluated with be WAIS, all of them fell within a normal intellectual range. The idea that Friedreich's Ataxia produces cognitive impairment and serious psychiatric symptoms came from the earliest descriptions of the disease at the beginning of this century, which probably included many patients in their samples who had other diseases.
Adolescent↗