Expenditures for the care of patients with HIV.
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Antiretroviral Therapy, Highly Active↗
Biomedical subjects
M Velasco
Publications and source records attributed to M Velasco.
[Sexual behavior risk in Spanish international travelers].
BACKGROUND: To know the sexual behavior of Spanish international travelers and its association with geographical destinations and sexually transmitted disease acquisition. PATIENTS AND METHOD: 1,008 consecutive patients who attended a tropical out-patient clinic during 26 months were surveyed by means of a previously designed clinical questionnaire that included specific questions regarding sexual practices during the trip. RESULTS: 19% of travelers had sexual intercourse; 53.6% of them having employed a condom. There were no differences regarding gender or destination. 3.4% of travelers who had unprotected sexual intercourse acquired HIV. CONCLUSIONS: A high proportion of travelers have unprotected, risk sexual contacts. A low but alarm
Adult↗
Centromedian-thalamic and hippocampal electrical stimulation for the control of intractable epileptic seizures.
The following two different modulatory procedures to control intractable epileptic seizures are presented: (1) chronic electrical stimulation of the centromedian-thalamic nucleus (ESCM) for control of generalized tonic-clonic seizures and atypical absences, and (2) subacute hippocampal stimulation (SAHCS) and chronic hippocampal stimulation for control of nonlesional temporal lobe seizures. The ESCM antiepileptic effect seems to be the result of activation of a nonspecific reticulothalamocortical system responsible for generalized electrocortical responses (recruiting, desynchronization, negative direct current shifts, and three spike-wave complexes per second). The success of the ESCM procedure depends on the following predictor factors: case selection (primary and secondary tonic-clonic seizures and atypical absences of the Lennox Gastaut syndrome), ventriculographic and electrophysiologic definition of the optimal stereotactic targets (based on the anterior commissure, posterior commissure, and the vertical line perpendicular to the posterior commissure and electrocortical recruiting responses), periodic electrophysiologic monitoring of the reliability of ESCM in the absence of the patient's subjective sensations and with totally internalized subcutaneous stimulation systems (by recording scalp electrocortical recruiting, desynchronizing, and direct current responses), quantitative evaluation of clinical and EEG improvement, and analysis of the ON and OFF effects, taking into account a long-lasting (possibly plastic) effect of ESCM. SAHCS blocks clinical and EEG signs of temporal lobe epileptogenesis with no additional damage of the stimulated hippocampal tissue. Preliminary results suggest that this antiepileptic effect is, at least in part, the result of a physiologic inhibition of the stimulated hippocampal tissue, because after SAHCS the authors found the following: (1) increased threshold and decreased duration, propagation, and blockage of the clinical signs accompanied with the hippocampal afterdischarge; (2) flattening of the hippocampal-evoked response recovery cycles; (3) single photon emission computed tomographic hypoperfusion; and (4) increased concentration of benzodiazepine receptor binding at the stimulated hippocampal region. Chronic hippocampal stimulation persistently blocked temporal lobe epileptogenesis in one patient under open protocols during 24 months with no apparent additional alterations in recent memory.
Brain Mapping↗
Electrical stimulation of the prelemniscal radiation in the treatment of Parkinson's disease: an old target revised with new techniques.
OBJECTIVE: In the treatment of tremor and rigidity in patients with Parkinson's disease (PD), the prelemniscal radiation (RAPRL), a subthalamic bundle of fibers, is an exquisite target that can be visualized easily on ventriculograms. We sought to evaluate the effect of electrical stimulation of the RAPRL on symptoms and signs of PD in a long-term trial and to determine the localization of the stimulated area by means of stereotactic magnetic resonance imaging studies. METHODS: Ten patients with PD predominantly on one side had tetrapolar electrodes stereotactically oriented through a frontal parasagittal approach to the RAPRL contralateral to the most prominent symptoms. Preoperative and postoperative evaluations at 3, 6, 9, and 12 months after surgery were performed using conventional PD scales and quantitative evaluations of tremor amplitude and reaction time. Stereotactic high-resolution magnetic resonance imaging studies with the electrodes in place were used for anatomic localization. RESULTS: In all patients, temporary suppression of tremor occurred when the electrodes reached the target. The most effective stimulation was obtained when the pair of contacts was placed in the RAPRL. Long-term stimulation at 130 Hz, 0.09 to 0.450 milliseconds, and 1.5 to 3.0 V produced significant improvement in tremor and rigidity and mild improvement in bradykinesia. CONCLUSION: The RAPRL is an effective target for the alleviation of tremor and rigidity in patients with PD by either lesioning or neuromodulation; however, neuromodulation has the advantage of not inducing an increase in bradykinesia. The stimulated area seems to be independent of the subthalamic nucleus.
Aged↗
Electrical stimulation for epilepsy: stimulation of hippocampal foci.
Subacute and chronic continuous electrical stimulation at the epileptic focus in the hippocampus or parahippocampal cortex at 130 Hz, 0.21-1.0 ms, 2.5-3.5 V (about 200-300 microA) induces a decrease in focal EEG epileptic interictal activity and also in the occurrence of clinical seizures. This may represent an alternative for the treatment of temporal lobe seizures originated in bilateral independent temporal lobe foci or occurring in patients where one is uncertain whether memory deficit might result from ablative procedures.
Electric Stimulation Therapy↗
Stimulation of the central median thalamic nucleus for epilepsy.
Electrical stimulation of the centromedian thalamic nucleus (ESCM) has been used in cases of difficult to control seizures with multifocal onset in frontal and temporal lobes, as well as in cases of seizures with no evidence of focal onset, such as Lennox-Gastaut syndrome. The stimulation program consists of 1 min stimulation on one side, 4 min interval OFF stimulation and 1 min stimulation on the other side, alternating from one side to the other for 24 h, at 60-130 Hz, 2.5-5.0 V, 0.21-0.45 ms. 49 cases have been treated and followed for periods of 6 months to 15 years. Results indicate that ESCM is highly efficient to control generalized tonic clonic seizures (GTC), atypical absences (AA) and tonic seizures (TS) and less efficient to control complex partial seizures (CxP).
Child↗
Semipersonalized psychological evaluation of quality of life in hypertensive patients during a trial with two calcium antagonists: a multicenter Latin-American Study (LASTLHY).
OBJECTIVE: The main objective of this study was to evaluate well-being and physical activity of 248 hypertensive patients, including 177 females, who had previously been included in the Latin-American Study on Lacidipine in Hypertension (LASTLHY). SUBJECTS, MATERIALS AND METHODS: This open study was carried out in 12 clinical centers in Argentina, Brazil, Colombia, Mexico and Venezuela, to compare, over a period of 16 weeks, the antihypertensive action of a fixed-dose, once daily of 4 mg lacidipine administered orally to 120 patients and 30 mg nifedipine GITS (Gastro-Intestinal Therapeutic System) administered to 128 patients, aged between 40 and 65 years. All patients had mild to moderate hypertension and treatment was begun at the end of a one-week placebo run-in period (end of week -1). Well-being and physical activity were assessed by means of single questionnaire, which reflected the physical and cultural diversities amongst the clinical centers and patients. The questionnaire included 13 multiple-choice and 8 contingent open questions. The score of each question was multiplied by a coefficient related to the importance of each question to the patient (semipersonalization); the coefficient was obtained from cultural and socioeconomic data collected at the time of enrollment. The semipersonalization was carried out by a blind psychological study with respect to the medication and had a high repeatability in the assignment of personalized coefficients to the score of each question. The scores of each question were added to obtain an overall well-being and activity scoring. The possible theoretical range for the overall scoring in this study was 10 - 124. RESULTS: See Table 1. CONCLUSION: The study revealed that the administration of calcium channel blockers such as lacidipine and nifedipine GITS, and lacidipine in particular, produced low incidence of side effects, and lacidipine in particular induced significant improvement in the quality of life.
Activities of Daily Living↗
Elevated liver enzymes following initiation of antiretroviral therapy.
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Anti-HIV Agents↗
Acoustic analysis after radiotherapy in T1 vocal cord carcinoma: a new approach to the analysis of voice quality.
PURPOSE: The study of acoustic voice parameters (fundamental frequency, jitter, shimmer, and harmonics-to-noise ratio) in extended vowel production, oral reading of a standard paragraph, spontaneous speech and a song in irradiated patients for Tis-T1 vocal cord carcinoma. METHODS AND MATERIALS: Eighteen male patients irradiated for Tis-T1 vocal cord carcinoma and a control group of 31 nonirradiated subjects of the same age were included in a study of acoustic voice analysis. The control group had been rigorously selected for voice quality and the irradiated group had previous history of smoking in two-thirds of the cases and a vocal cord biopsy. Radiotherapy patients were treated with a 6MV Linac receiving a total dose of 66 Gy, 2 Gy/day, with median treatment areas of 28 cm(2). Acoustic voice analysis was performed 1 year after radiotherapy, the voice of patients in extended vowel production, oral reading of a standard paragraph, spontaneous speech, and in a song was tape registered and analyzed by a Kay Elemetric's Computerized Speech Lab (model CSL# 4300). Fundamental frequency, jitter, shimmer, and harmonics-to-noise ratio were obtained in each case. Mann Whitney analysis was used for statistical tests. RESULTS: The irradiated group presented higher values of fundamental frequency, jitter, shimmer, and harmonics-to-noise ratio. Mann-Whitney analysis showed significant differences for fundamental frequency and jitter in vowel production, oral reading, spontaneous speech, and song. Shimmer only showed differences in vowel production and harmonics-to-noise ratio in oral reading and song. CONCLUSIONS: In our study only fundamental frequency and jitter showed significant increased values to the control group in all the acoustic situations. Sustained vowel production showed the worst values of the acoustic parameters in comparison with the other acoustic situations. This study seems to suggest that more work should be done in this field.
Aged↗
Neuromodulations of the intractable neurologic symptoms
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Journal Article↗
Seizures induced by penicillin microinjections in the mesencephalic tegmentum.
The location and extension of a convulsive area in the brain stem in cats was determined through penicillin microinjections (0.5-1.0 microl) of a concentrated sodium penicillin solution (500 IU/microl), stereotactically oriented to multiple structures, in fully awake animals, partially restrained through a rod fixation system that avoided pain, allowed the observation of clinical seizures and simultaneous recording of EEG, EMG and multiple unit activity (MUA) from the injected site and the motor cortex (Cx). Clinical and EEG seizure patterns in relation to the injected sites and penicillin doses were studied in another group of animals using doses from 12.5 IU/0.1 microl to 125 IU/1.0 microl. The time relationship between muscular clonus, EEG spikes and MUA at the injected site and Cx were analyzed. The only area in which penicillin induced seizures was the mesencephalic tegmentum (MT). The amount of penicillin but not the stereotactic coordinates determined the seizure type. MT EEG and MUA paroxysms anticipated clinical seizure and Cx EEG spikes. When Cx EEG appeared, they were accompanied by an increase in MUA beginning in the Cx and EMG, followed by significant increase in MT MUA. The sequence of events suggest that MT seizure activity propagates via alternative pathways not involving direct reticulospinal or pyramidal tract pathways.
Animals↗
Hypertension and cardiovascular health in Venezuela and Latin American countries.
Since 1950 all countries of the Latin-American subcontinent have experienced very important changes in several health indicators, in the demographic, epidemiological, socio-cultural and way of living profiles. The proportion of the population over 65 years old tend to be low in the Latin American countries in contrast to developed countries. Cardiovascular diseases are the main cause of death in most of the Latin American countries at a similar rate to that of the developed world. As infectious diseases are reduced, cardiovascular diseases takes their place as the main cause of death in Latin American countries. Prevalence of hypertension in different reports show variations from 40 to 8% in the adult population, but on average 20 to 23% of the adult population have elevated blood pressure. This prevalence is similar to reports in the developed world. However there is considerable variability in each country and its regions so it is important that local studies of prevalence and local factors in the development of hypertension are investigated. The degree of awareness, treatment and control of hypertension is lower than that reported in the developed world, and it is important to establish programmes to attend to this public health problem, from prevention to treatment, from primary care to higher levels of attention.
Age Factors↗
Endothelial dysfunction in arterial hypertension.
Systemic arterial pressure is a dynamic and reactive physiological parameter depending on a great many factors. The endothelial cells of the vascular system are responsible for many biochemical reactions maintaining vascular homeostasis and therefore arterial pressure. Arterial hypertension, atherosclerosis and endothelial dysfunction constitute risk factors increasing morbidity and mortality of cardiovascular origin. These three elements are closely related and frequently act simultaneously damaging different organs. In this paper we review the physiology of the endothelium and the probable consequences of endothelial dysfunction on the pathophysiology of arterial pressure.
Arteries↗
Diabetes and hypertension physiopathology and therapeutics.
Diabetes mellitus by itself, is a frequent and increasing public health problem. The prevalence in most Western countries varies between 2 to 5% and it is rapidly increasing in Asiatic countries due to changes in dietary habits during the last years. The association between diabetes mellitus and hypertension has been described in 60 to 65% of diabetics. In hypertension we find insulin resistance mainly in skeletal muscle involving the conversion of glucose to glycogen independently of blood flow. The degree of resistance is related to the severity of hypertension and varies between races. States of hyperinsulinaemia and insulin-resistance have been postulated as causes and/or consequences of hypertension. Regardless of the type of diabetes, hypertension is two to three times more common among diabetics compared with non-diabetics. In this paper we propose to review the essential physiopathological mechanisms involved in this association that causes high morbidity and mortality rates and increases disability among the population involved.
Antihypertensive Agents↗
Angiotensin II receptor antagonists in arterial hypertension.
Angiotensin II receptor antagonists (AT-1) represent a new group of orally active antihypertensive agents. Activation on AT-1 receptor leads to vasoconstriction, stimulation of the release of catecholamines and antidiuretic hormone with production of thirst, and promote growth of vascular and cardiac muscle; these effects are blocked by AT-1 antagonist agents. The first chemically useful, orally active AT-1 receptor antagonist was losartan, followed by other agents currently in clinical use, such as: valsartan, eprosartan, irbesartan, telmisartan, candesartan, and many others under investigation. AT-1 receptor antagonists are effective in reducing high blood pressure in hypertensive patients. Monotherapy in mild to moderate hypertension controls blood pressure in 40 to 50% of these patients; when a low dose of a thiazide diuretic is added, 60 to 70% of patients are controlled. The efficacy is similar to angiotensin-converting enzyme inhibitors, diuretics, calcium antagonists and beta-blocking agents. Tolerability has been reported to be very good. AT-1 receptor antagonists would be a drug of choice in otherwise well-controlled hypertensive patients treated with angiotensin-converting enzyme inhibitors who developed cough or angioedema. The final position in the antihypertensive therapy in this special population and other clinical situations, such as left ventricular hypertrophy, heart failure, diabetes mellitus and renal disease, has to be determined in large prospective clinical trials, some of which are now being conducted.
Angiotensin Receptor Antagonists↗
Effect of lacidipine and nifedipine GITS on platelet function in patients with essential hypertension.
With the aim of evaluating the effects on blood pressure, platelet function and insulin sensitivity of the dihydropiridines lacidipine and nifedipine GITS, a parallel double-blind study was carried out in a group of 20 patients with mild to moderate essential hypertension. They received a placebo for 4 weeks; then were divided at random into two groups of 10 patients each. Nifedipine GITS, 30 mg and lacidipine, 4 mg, were given during 16 weeks of active treatment. Blood pressure and heart rate were measured at the clinic in supine, sitting and standing positions, 24 +/- 1 h after the last dose. After the placebo and active phases were carried out, a platelet aggregation test was performed to determine platelet malondialdehyde production and a tolerance to 100 g of glucose by measuring glucaemia and plasma insulin. Both drugs reduced systolic and diastolic blood pressure at the same level, however there were observable differences in the rate of reduction. The nifedipine GITS reduced supine systolic blood pressure by 25 mm Hg in the first week, while the lacidipine did so by 11 mm Hg. At the end of the study period nifedipine reduced supine systolic blood pressure by 28 mm Hg and lacidipine by 20 mm Hg. Heart rate was increased slightly but significantly in the nifedipine GITS group only in the standing position. Both drugs reduced platelet aggregation ex vivo only marginally but they modified the malondialdehyde production, indicating an action on the arachidonic acid metabolic pathway.
Arachidonic Acid↗
Spatiotemporal profile of synaptic activation produced by the electrical and visual stimulation of retinal inputs to the optic tectum: a current source density analysis in the pigeon (Columba livia).
The optic tectum of the pigeon is a highly organized, multilayered structure that receives a massive polystratified afference of at least five different populations of retinal ganglion cells and gives rise to various anatomically segregated efferent systems. The synaptic organization of retino-tectal circuitry is, at present, mostly unknown. To investigate the spatiotemporal profile of synaptic activation produced by differential (electrical and visual) stimulation of the retinal inputs, we performed a high-spatial-resolution current source density analysis in the optic tectum of the anaesthetized pigeon. Electrical stimuli consisted of brief pulses of different durations applied to the optic nerve head, while visual stimuli consisted of light flashes of different intensities. Electrical stimulation generated sinks confined to retinorecipient layers. The temporal structure, spatial location and thresholds of these sinks indicated that they are all due to primary tectal synapses of retinal fibers with different conduction velocities. Sinks evoked by the fastest retinal axons were more superficially located than sinks produced by slower retinal fibers. Visual stimulation, on the other hand, resulted in a more complex pattern of current sinks, with various sinks located in the retinorecipient layers and also well below. Visual stimulation induced action potentials at superficial as well as deep tectal levels. We conclude that electrical stimulation activates most of the populations of ganglion cells as well as their primary tectal synapses, but is unable to elicit a significant activation of secondary tectal synapses. Visual stimulation, on the contrary, activates just some of the incoming retinal populations, but in a way that produces noticeable secondary activation of intratectal circuits. Laminar segregation of retinally evoked tectal activity, as reported here, has also been found in other vertebrates. Similarities and differences with previous studies are discussed.
Animals↗
Economic impact of HIV protease inhibitor therapy in the global use of health-care resources.
OBJECTIVE: To evaluate the clinical and economical impact of the introduction of HIV protease inhibitor (PI) therapy in the current clinical care of HIV-infected patients. METHODS: Cohort study with 155 HIV-infected patients with a full year of follow-up before and after the introduction of PI by June 1998. The setting was a large urban tertiary teaching hospital in Madrid, Spain. The main outcomes measures were clinical and immunological evolution, pharmacy, out-patient, emergency room and in-patient medical costs evaluated by diagnostic-related group classification, and the global economic costs of clinical care in HIV-infected patients (AIDS and non-AIDS). RESULTS: The cost of PI therapy was compensated fully by savings related to reduction of the number, length and severity of hospital admissions in AIDS cases. In contrast, more modest clinical effects with increased costs were observed in non-AIDS cases. Globally, there was an increase of about 20% in the total health-care costs of HIV-infected patients (P < 0.01). CONCLUSIONS: PI therapy is highly cost-effective in AIDS patients. Its value in less severely immunosuppressed patients requires further evaluation.
Adult↗