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Biomedical subjects

A de Diego

Publications and source records attributed to A de Diego.

At least 19 recordsLinked to original sources
PubMed2005

[Prevalence of hyperventilation syndrome in patients treated for asthma in a pulmonology clinic].

OBJECTIVE: Although the presence of hyperventilation syndrome can affect the symptoms of patients with asthma, there is very little information available regarding its frequency in Spain. The aim of this study was to investigate the prevalence of hyperventilation syndrome in the asthmatic population treated as outpatients and establish its relationship with anxiety disorders. PATIENTS AND METHOD: We studied 157 consecutive asthmatic patients (61 men and 96 women; mean [SD] age, 45 [17] years; forced expiratory volume in the first second, 84% [21%] of the predicted value) treated in our outpatients clinic. The patients had stable disease with varying degrees of severity. After collecting demographic data and medical histories, we asked the patients to complete the Spanish versions of the Anxiety Sensitivity Index, the Asthma Symptom Checklist, and the Nijmegen questionnaire; in the latter test, a score of 23 or over was considered diagnostic for hyperventilation syndrome. Finally, patients were evaluated to determine whether they had suffered from panic disorder in the last 6 months (according to the criteria of the fourth edition of the Diagnostic and Statistical Manual of Mental Disorders). RESULTS: Hyperventilation syndrome was present in 57 asthmatic patients (36%) and panic disorder in 4 patients (2%). The majority of patients with hyperventilation syndrome were women (78% vs 51%; P=.001) and were older (49 vs 42; P=.01); they displayed more basal dyspnea (1.26 vs 0.89 on the Medical Research Council scale; P=.01), greater sensitivity to anxiety (P=.001), and went to the emergency room more often for exacerbations (P=.002). Patients with hyperventilation syndrome scored significantly higher on all subscales of the Asthma Symptoms Checklist. Finally, the variables introduced in the regression analysis (stepwise) to explain the score on the Nijmegen questionnaire (r(2)=0.57) were basal dyspnea and sensitivity to anxiety. CONCLUSIONS: Approximately one third of the asthmatic patients treated in a pulmonology clinic also present hyperventilation syndrome. This cannot be explained by comorbidity of asthma with panic disorder, and is only partly linked to the symptoms associated with hyperventilation that appear during an asthma attack.

Adult↗
PubMed2005

[Agreement in asthmatics' perception of dyspnea during acute and chronic obstruction].

OBJECTIVE: Three types of asthmatic patients can be identified during periods of clinical stability: "poor perceivers," "normal perceivers," and "over perceivers." When asthmatics undergo bronchial challenge in the laboratory, the same distinctions in type of perception can be observed. The aim of the present study was to determine the level of agreement between the 2 situations. PATIENTS AND METHODS: A total of 93 patients with persistent moderate asthma (36 men and 57 women; mean age 40 years) were studied. We asked them to assess their dyspnea on a modified Borg scale when stable and after each histamine dose in a bronchial provocation test. When a patient's Borg scale assessment in stable situation was below the 25th percentile, that patient was classified as a poor perceiver. Patients were considered over perceivers if their score in stable situation was in the 75th percentile. Others were labeled normal perceivers. Type of perception during acute bronchoconstriction was defined in function of the change in Borg assessment once forced expiratory volume in the first second had decreased 20%: poor perceivers were those whose change in Borg assessment was in the 25th percentile, over perceivers were in the 75th percentile, and normal perceivers in the middle percentiles. RESULTS: In stable situation, 23 patients were poor perceivers, 58 were normal perceivers, and 12 were over perceivers. During bronchoconstriction, there were 23 poor perceivers, 47 normal perceivers, and 23 over perceivers. Agreement was estimated by a kappa index of 0.0574 for poor perception, 0.1521 for over perception, and 0.3980 for normal perception. CONCLUSIONS: Asthmatics' perception of dyspnea during periods of stability and during acute bronchoconstriction are independent phenomena. It is therefore not possible to infer how a patient will perceive an asthmatic attack by evaluating only how he or she perceives breathlessness during stable periods.

Acute Disease↗
PubMed2003

[Characterization of de novo malignancies in liver transplantation].

INTRODUCTION: The incidence of de novo malignancies after liver transplantation varies from 3-15%, and is greater than that in the general population. Immunosuppression may play a significant role in the development of most of these tumors. OBJECTIVE: To evaluate the incidence and clinical features of de novo tumors in liver transplant recipients in our center as well as to assess survival. PATIENTS AND METHODS: We retrospectively analyzed 437 liver transplantations (380 patients) performed from April 1990 to July 2001. The incidence of de novo malignancies was 7.4% (n = 28). Four patients presented two different tumors during their lifetime. The etiology of the underlying disease was alcoholic cirrhosis (45.8%), hepatitis C virus cirrhosis (20.8%), hepatitis B virus cirrhosis (12.5%), autoimmune disease (8.4%) and other causes (12.5%). The most frequent neoplasms were cutaneous and epidermoid tumors (21.4% of the malignancies both groups). All the patients with epidermoid tumors and adenocarcinomas were active smokers. The mean age at diagnosis was 58 9 years and this was a factor that influenced tumoral type (adenocarcinomas in older patients and epidermoid tumors in younger patients; p = 0.04). RESULTS: Sarcomas and adenocarcinomas appeared sooner after transplantation than epidermoid and cutaneous tumors (p = 0.04). Fifty percent of the malignancies developed in the second and third year after transplantation. The type of immunosuppression did not influence tumoral type, although most patients received cyclosporin A in combination with azathioprine and/or corticoids. The mean duration of follow-up after diagnosis of the tumor was 23.1 28 months (range, 1-81). Mortality was 58.4% with a median survival of 9 16 months. The actuarial probability of survival at 1, 3 and 5 years was 46.1, 27.7 and 27.7%, respectively. CONCLUSIONS: De novo malignancies are frequent after liver transplantation and their clinical course differs from that in the general population. Because their clinical course is more aggressive, regular follow-up of these patients is essential for early diagnosis.

Adult↗
PubMed2003

[Asthma patients' perception of dyspnea during acute bronchoconstriction].

The aim of this study was to analyze variations in the perception of acute bronchial obstruction among asthmatics in our practice and to try to define the variables that influence inter-individual differences. We studied 153 asthmatics in stable condition, using a Borg scale to measure dyspnea perceived during a histamine bronchial challenge test. To study individual perception we analyzed both absolute magnitude of perception of dyspnea on the Borg scale when forced expiratory volume in 1 second (FEV1) fell 20% (perception score 20-PS20) and the mathematical difference between PS20 and baseline dyspnea (change in Borg, CB). The results were as follows. 1) The factors that affected PS20 according to multiple linear regression were anxiety, baseline dyspnea and the provocative concentration required to produce a 20% fall in FEV1 (PC20). 2) Within each level of asthma severity, there were differences in dyspnea perception when FEV1 fell 20% (analysis of variance of repeated measures), such that patients with mild asthma and no bronchial obstruction perceived more change in dyspnea. 3) CB during the bronchial challenge test distinguished four ways of perceiving dyspnea: 15% were dysperceivers, 13% were hypoperceivers, 48% were normoperceivers and 24% were hyperperceivers. 4) Hypoperceivers and dysperceivers were at greater risk of severe exacerbation whereas hyperperceivers requested unnecessary medical consultations. 5) Subjects with poorer quality of life were usually dysperceivers; hyperperceivers were the second most common type among those with poorer quality of life. In conclusion, a large percentage of asthmatics do not appropriately perceive acute bronchial obstruction, and the simplest way to evaluate their perception is to calculate the change in dyspnea (on a Borg scale) during the bronchial challenge test. The manner of perceiving dyspnea can not be predicted beforehand, yet it has a significant impact on the use of medical resources and patient quality of life, among other aspects.

Acute Disease↗
PubMed2003

Cough reflex testing with inhaled capsaicin in the study of chronic cough.

OBJECTIVES: To assess the utility of capsaicin test in the differential diagnosis of non-productive causes of chronic cough and to examine the effects of treatment on this reflex. PARTICIPANTS: 86 healthy volunteers and 101 patients with chronic cough: asthma (n: 54) gastroesophageal reflux (n: 35) and post-nasal drip syndrome (n: 12). DESIGN: Prospective intervention trial. Spirometry, bronchoprovocation test with histamine (PC20), and cough challenge with ascending concentrations of capsaicin (0.49-500 microM) were initially performed in all subjects. Patients were treated for 3 months according to the origin of the cough. Concentrations that elicited two (C2) and five or more coughs (C5) were determined before and after treatment. RESULTS: In healthy subjects, cough sensitivity to capsaicin was not influenced by gender or smoking status; however, women with chronic cough were more sensitive to cough challenge than men. C2 and C5 were significantly lower in patients with asthma or gastroesophageal reflux than in post-nasal drip syndrome. No significant correlation was observed between the capsaicin cough threshold and PC20. Cough sensitivity did not improve significantly in most patients with asthma or gastroesophageal reflux despite adequate medical treatment during 3 months. Discriminative value of capsaicin test to differentiate healthy subjects from patients with asthma or reflux was poor. CONCLUSIONS: Cough sensitivity to inhaled capsaicin is a safe and reproducible tool in the study of chronic cough. However, its usefulness for the management and differential diagnosis is limited.

Administration, Inhalation↗
PubMed2002

[Variability of the clinical expression of Ecstasy-induced hepatotoxicity].

3,4-methylenedioxymethamphetamine (MDMA) is an amphetamine derivative, known as ecstasy. Because of its euphoric effects, the use of this substance as a drug of abuse is becoming increasingly widespread. The development of hyperthermia, disseminated intravascular coagulation, rhabdomyolysis, acute renal failure, cardiac arrhythmia and neurotoxicity have been described in association with the use of this drug. Moreover, in the last few years, cases of liver involvement, associated or not with the above-mentioned entities, have been described, ranging from mild acute hepatitis to fulminant hepatic failure and death. We present four cases of ecstasy-induced hepatotoxicity. Outcome was favorable in three patients while the fourth required liver transplantation. Consequently, ecstasy ingestion should be ruled out as a cause of acute non-viral hepat

Abdominal Pain↗
PubMed2002

[Perception of improvement in asthma patients].

The objective of this study was to investigate the ability of patients with stable asthma to recognize improvement in bronchial obstruction with treatment. We enrolled 75 stable asthmatics (44 women and 31 men, mean age 43 17 years) who reported baseline dyspnea on a modified Borg scale. Acute bronchodilation of 15% was provoked in the laboratory, after which the patients were asked if there was a change in dyspnea. Our results were as follows. 1) Overall, 19 asthmatics (25%) failed to perceive improvement in dyspnea with bronchodilation. 2) The mean change in dyspnea was 1.17 1.11, although the change was greater in patients with more severe asthma (0.60 0.5 for mild asthmatics, 1.05 1.07 for moderate asthmatics and 1.93 1.4 for severe asthmatics; p < 0.0001). 3) Perception of improvement was significantly related to level of the patient's emotional balance (anxiety-depression), quality of life, education, socioeconomic level, age, age of onset, severity, baseline dyspnea and obstruction, thoracic pressure and number of visits to the doctor in the preceding year. 4) The variables entered into the stepwise regression model were baseline dyspnea, depression, thoracic pressure and age. 5) Generally, young asthmatics whose disease appeared at a younger age and who also had less ventilatory obstruction and greater quality of life, showed a tendency to underestimate the beneficial effect of bronchodilator treatment. Moreover, when asthma was severe, non-perceptive individuals had significantly more admissions to intensive care units due to asthma exacerbation.In conclusion, 25% of our asthmatics are unable to recognize whether their bronchia dilate as a result of treatment, meaning that they would delay the start of rescue medication during an exacerbation. Such patients should be identified in order to establish therapeutic guidelines in function of objective home criteria (peak-flow monitoring).

Adolescent↗
PubMed2001

[Diagnostic utility of hepatic hemodynamics study in hepatoportal sclerosis].

AIM: To evaluate the diagnostic utility of catheterization of the suprahepatic veins in patients with suspected non-cirrhotic portal hypertension as well as to characterize the clinical features and evolution of this process. PATIENTS AND METHODS: Hepatic hemodynamics studies, transjugular biopsy and venography were performed in seven patients with suspected non-cirrhotic portal hypertension. In all patients the combination of the three procedures gave the diagnosis of hepatoportal sclerosis, which was subsequently confirmed by direct portography and percutaneous or laparoscopic liver biopsy. RESULTS: Three patients presented esophageal variceal bleeding at diagnosis. Only one patient required intrahepatic shunting due to refractory bleeding. None of the patients required surgical shunting or presented alterations in liver function. CONCLUSIONS: Hepatic hemodynamics study with transjugular biopsy and venography is an effective procedure in the diagnosis of hepatoportal sclerosis and in most cases invasive confirmatory tests are not required. The course of the disease is relatively benign if variceal bleeding is controlled. The treatment of choice in these patients is pharmacological and endoscopic.

Adult↗
PubMed2000

Modulation of ICAM-1 tissue expression in patients with liver transplantation (LT) and acute rejection (AR) after glucocorticoid treatment.

Acute rejection (AR) is a frequent complication following liver transplantation (LT). ICAM-1 may be involved in its pathogenesis. High doses of glucocorticoids are the standard treatment in these patients. The aim of this study was to describe corticoid effects on ICAM-1 tissue expression in liver biopsies of patients with LT and AR. The study included liver biopsies performed before and after treatment in 12 patients with LT and proven AR. In 10 patients AR was reversible and in 2, was steroid resistant. For immunohistochemistry, an indirect immunoperoxidase technique was used. Each histology section was semiquantitatively evaluated as follows: 0: < 10% staining, 1: 10-25%, 2: 25-50%, 3: > 50%. The control group comprised nine patients with LT and normal liver biopsies. In pre-treatment liver biopsy samples, ICAM-1 was markedly expressed on sinusoidal cells (2.41 +/- 0.66), and there was also expression on periportal (0.66 +/- 0.65) and perivenular hepatocytes (0.83 +/- 0.57). By contrast, in the liver tissue from the control group, sinusoidal ICAM-1 reactivity was significantly lower (0.88 +/- 0.33; P < 0.05), and hepatocytes showed no reliable ICAM-1 expression. After steroid treatment the intensity of ICAM-1 decreased significantly in sinusoids (1.5 +/- 0.67; P < 0.05) and in perivenular hepatocytes (0.25 +/- 0.86; P < 0.05). Additionally, we also observed a decreased ICAM-1 reactivity in portal hepatocytes (0.25 +/- 0.62), but these differences did not reach statistical significance. Remarkably, after treatment, hepatocytes did not show ICAM-1 reactivity in resolved AR, but in corticoid-resistant patients AR did not change or increase. In conclusion, in patients with LT and AR, ICAM-1 was expressed in hepatocytes and with more intensity in sinusoid cells. Additionally, a down-regulation of the ICAM-1 tissue expression after corticoid treatment may exist, although in corticoid-resistant AR no modulation on ICAM-1 tissue expression was observed.

Acute Disease↗
PubMed1999

Carvedilol, a new nonselective beta-blocker with intrinsic anti- Alpha1-adrenergic activity, has a greater portal hypotensive effect than propranolol in patients with cirrhosis.

Only some patients show a substantial hepatic venous pressure gradient (HVPG) reduction after propranolol, which makes it desirable to investigate drugs with greater portal hypotensive effect. The aim of this study was to investigate whether carvedilol, a nonselective beta-blocker with anti-alpha1-adrenergic activity, may cause a greater HVPG reduction than propranolol. Thirty-five cirrhotic patients had hemodynamic measurements before and after the random administration of carvedilol (n = 14), propranolol (n = 14), or placebo (n = 7). Carvedilol markedly reduced HVPG, from 19.5 +/- 1.3 to 15.4 +/- 1 mm Hg (P <.0001). This HVPG reduction was greater than after propranolol (-20.4 +/- 2 vs. -12.7 +/- 2%, P <.05). Moreover, carvedilol decreased HVPG greater than 20% of baseline values or to </=12 mm Hg in a greater proportion of patients (64% vs. 14%, P <.05). Both drugs caused similar reductions in hepatic and azygos blood flows, suggesting that the greater HVPG decrease by carvedilol was because of reduced hepatic and portocollateral resistance. Propranolol caused greater reductions in heart rate and cardiac output than carvedilol, whereas carvedilol caused a greater decrease in mean arterial pressure (-23.1 vs. -11%, P <.05). Thus, carvedilol has a greater portal hypotensive effect than propranolol in patients with cirrhosis, suggesting a greater therapeutic potential. However, it causes arterial hypotension, which calls for careful evaluation before its long-term use.

Adrenergic alpha-Antagonists↗
PubMed1999

[Arterial complications after liver transplantation: early and late forms].

Arterial complications after liver transplantation (OLT) was related with high morbimortality rates, with variable consequences on patient and graft survival. 234 patients who underwent 270 liver transplantation between april of 1990 and december 1996 have been evaluated. Arterial complications were detected in 34 patients (12.5%), hepatic artery stenosis in 10 patients (29.4%), thrombosis in 24 (70.6%) and aneurysm in 2 (5.9%). It was considered early artery complications those diagnosed at the first month after OLT, and late complications the latest ones. Diagnosis was realized by Doppler sonography in all cases, and confirmed by celiac arteriography in those with Doppler abnormal findings. Clinical appearance of early artery complications were as acute liver failure (61.1%) or graft disfunction (38.8%). On the other hand, late complications were diagnosed incidentally in 46% of the patients due a programmed Doppler follow up. Actuarial survival at 24 months was higher in patients with late arterial complication (50 vs 30%; p < 0.01). Therapeutic measures applied were retransplantation, surgical artery reconstruction and angioplasty. Early complications required more frequently retransplantation or surgical reconstruction. Risk factors related with artery complications development were analyzed, but not significant differences between both types of arterial complications were found. It is concluded that programmed follow up by Doppler or arteriography is necessary to make an earlier diagnose and to detect silent arterial complications.

Adult↗
PubMed1998

Dehydroluciferyl-AMP is the main intermediate in the luciferin dependent synthesis of Ap4A catalyzed by firefly luciferase.

It was previously assumed that E x LH2-AMP was the intermediate complex in the synthesis of Ap4A catalyzed by firefly luciferase (EC 1.13.12.7), when luciferin (LH2) was used as cofactor. However, here we show that LH2 is partly transformed, shortly after the onset of the luciferase reaction, to dehydroluciferin (L) with formation of an E x L-AMP complex which is the main intermediate for the synthesis of Ap4A. Formation of three more derivatives of LH2 were also observed, related to the production of light by the enzyme. CoA, a known stimulator of light production, inhibits the synthesis of Ap4A by reacting with the E x L-AMP complex and yielding L-CoA.

Adenosine Monophosphate↗