Biomedical subjects

F Torres

Publications and source records attributed to F Torres.

At least 73 records · Page 4Linked to original sources

PubMed1994

[An analysis of the factors and phenomena associated with the formation of a spontaneous echo contrast in the left atrium].

INTRODUCTION AND AIMS: To determine the factors related to the formation of spontaneous echo contrast in left atrium. PATIENTS AND METHODS: We have analyzed our series of 1,066 patients undergoing transesophageal echocardiography until December 1991. It was found in left atrium in 387 patients (36%) and was associated with another pathology in 99%. We defined spontaneous echo contrast as mild in 64% and severe in 36%. RESULTS: The prevalence of spontaneous echo contrast was greater in patients with atrial fibrillation (p < 0.001), mitral stenosis (p < 0.001), double mitral lesion (p < 0.001), prosthesis (p < 0.001), embolism (p < 0.05) and a dilated left atrium (left atrial dimension greater than 60 ml) (p < 0.01). The presence of mitral regurgitation made it less frequent (p < 0.05). Thrombi were visualized in 104 patients and they were more frequent in the presence of spontaneous echo contrast. Severe spontaneous echo contrast was significantly more frequent in patients with atrial fibrillation (p < 0.001), mitral stenosis (p < 0.05) and thrombi (p < 0.001). CONCLUSIONS: Spontaneous echo contrast in left atrium is a common finding in transesophageal studies and it is associated with another pathology in 99%. It is more frequent in patients with atrial fibrillation, mitral stenosis, embolism or prosthesis. Left atrial enlargement is one of the more important factors. It is less frequent in patients with mitral regurgitation. Thrombi are less frequent in patients without spontaneous echo contrast. Severe spontaneous echo contrast is significantly associated with mitral stenosis, atrial fibrillation and left atrial thrombi.

Acute Disease↗

PubMed1993

Clinical and hemodynamic predictors of survival in patients aged < 65 years with severe congestive heart failure secondary to ischemic or nonischemic dilated cardiomyopathy.

To identify which clinical or hemodynamic parameters predict survival in patients with end-stage heart failure due to dilated cardiomyopathy, 130 consecutive patients aged < 65 years (mean 46 +/- 13) assessed for heart transplantation from May 1986 to April 1991 were studied. Mean follow-up was 15 +/- 11 months. Left ventricular ejection fraction was 22 +/- 7%. Left ventricular end-diastolic pressure was 27 +/- 9 mm Hg, and cardiac index was 2.2 +/- 0.6 liter/min/m2. Symptom class was IV in 91% of patients and III in 9%. Etiology was ischemic in 40% of patients and idiopathic in 60%. After intensive medical therapy, heart transplantation was considered indicated in 53% of patients, contraindicated in 20% and not indicated in 27%. Transplantation was performed in 36% of patients during follow-up, and 35% died and 29% were alive without transplantation. A comparison, excluding patients with transplantation, was performed between those who were alive and had survived > or = 6 months after assessment, and those who died. On multivariate analysis, the following 3 parameters were independent predictors of prognosis: intravenous inotropic requirement (p < 0.001), maximal, tolerated captopril dose (p = 0.013) and systolic blood pressure (p = 0.003). When patients with transplantation were considered as deaths, stabilization on medical therapy also reached statistical significance (p = 0.009). Classic prognostic markers including ventricular arrhythmias, left ventricular end-diastolic pressure, cardiac index, amiodarone therapy and etiology were not associated with prognosis in this homogeneous population of severely ill patients.

Adolescent↗

PubMed1993

Plasticity of the sensorimotor cortex representation of the reading finger in Braille readers.

We studied the organization of the somatosensory cortex in proficient Braille readers, recording somatosensory evoked potentials (SEPs) in 10 subjects and using transcranial magnetic stimulation (TMS) in five subjects, and compared the results with those of 15 control subjects. Somatosensory evoked potentials were elicited by a focal electrical stimulus to the tip of the index finger and recorded from a contralateral 4 x 4 grid of scalp electrodes centred around C3' and C4'. Transcranial magnetic stimulation, with an 8-shaped coil centred over the same scalp positions, was delivered simultaneously with, and at different intervals after, the finger stimulus. The results of the right index (reading) finger in Braille readers were compared with those of their left index (non-reading) finger and of the right and left index fingers of the control subjects. The scalp areas from which we recorded N20 and P22 components of the SEP with an amplitude of at least 70% of the maximal amplitude recorded in each trial were significantly larger in SEPs evoked from the reading fingers. Detection of the stimulus applied to the reading finger was blocked by TMS delivered over a larger contralateral scalp area and during a longer time window after the stimulus. These experiments suggest that reading Braille is associated with expansion of the sensorimotor cortical representation of the reading finger.

Adult↗

PubMed1993

Pharmacokinetic interaction between high-dose methotrexate and amoxycillin.

A case report of toxicity following concurrent administration of high-dose methotrexate and amoxycillin is presented. A 16-year-old male patient was administered 10 high-dose methotrexate cycles for treatment of a fully malignant osteogenic sarcoma. Methotrexate was administered at a dosage of 8 g/m2 and infused intravenously over a 6-h period. The patient received pre- and posttreatment hydration and sodium bicarbonate for alkalinization of urine. Calcium folinate rescue was performed when appropriate. During the 10th cycle, coadministration of amoxycillin (1 g/6 h, p.o.) resulted in prolonged and marked enhancement of methotrexate serum levels. Pharmacokinetic parameters obtained in cycle 10 indicate significant differences for total plasma clearance, mean residence time, and distribution half-life when compared to those in cycles 1-9. Amoxycillin decreased the renal clearance of methotrexate, probably by competition at the common tubular secretion system and by secondary methotrexate-induced renal impairment. The patient experienced acute and subacute toxicity with renal failure, myelosuppression, mucositis, nausea, vomiting, fever, and dermatologic abnormalities. Patients receiving amoxycillin during methotrexate therapy should be closely monitored to avoid severe toxicity.

Adolescent↗

PubMed1993

[Patients with an acute myocardial infarct treated in a coronary unit or in a general cardiology ward A comparative study].

INTRODUCTION AND OBJECTIVES: Coronary care units have been accepted as the standard location for treatment for patients with acute myocardial infarction. Nevertheless, controversy over their clinical impact, current role and cost-effectiveness still remains. Due to the increased incidence of coronary artery disease in Spain, coronary care units are often full, and patients with acute myocardial infarction must be cared for in a general cardiology ward. METHODS: We have studied the features and results of 420 patients with acute myocardial infarction consecutively admitted to our hospital and compared patients cared for in the coronary care unit (329 [78%]) with those cared for in the cardiology ward (91 [22%]). Admission to cardiology ward or coronary care unit was based on the clinical judgment of emergency room physicians and the bed availability. No differences in age, sex, risks factors, prior history of coronary heart disease, blood pressure on admission, extension and complications of myocardial infarction were found between both groups. RESULTS: The percentage of patients with evolved and non-Q wave acute myocardial infarction, and admission electrocardiogram not suggestive of infarction was significantly higher in ward group (23 versus 2.4%, p < 0.001; 19 versus 11%, p < 0.01; and 43 versus 15%, p < 0.01; respectively). Although patients admitted to the coronary care unit underwent intravenous thrombolysis and coronary artery revascularization procedures in a higher proportion, mortality was similar in both groups (14% for ward patients and 17% for coronary care unit patients). When patients with evolved or non-Q wave infarctions and those with admission electrocardiograms not suggestive of infarction were excluded from the analysis, mortality rates remained similar. Subgroups mortality was in general similar for patients cared for in cardiology ward or in coronary care unit, although patients without shock, with Killip class I or II, and older than 70 years, had a slightly lesser mortality when treated in the Cardiology ward (5 versus 11%, 6 versus 11%, and 14 versus 28%, respectively). By contrast, patients with shock, Killip class III or IV, and electrocardiogram at admission not suggestive of infarction, had a lesser mortality when cared for in coronary care unit. CONCLUSIONS: We conclude that some subgroups of patients with acute myocardial infarction can be, if needed, effective and safely cared for in cardiology ward.

Aged↗

PubMed1993

[Infectious endocarditis due to Q fever. A report of 4 new cases].

Q fever (Coxiella burnetii) is an uncommon cause of culture-negative infective endocarditis. Four cases of Q fever endocarditis diagnosed at our hospital in the last 7 years are reported (8% of all infective endocarditis). Infection involved a prosthetic heart valve in 3 cases (15% of all prosthetic valve endocarditis), and one patient with single ventricle and pulmonary stenosis in the remaining case. Important complications developed in all cases, and 3 patients underwent cardiac surgery. Mortality was 50%. Some diagnostic and therapeutical aspects of this disease are discussed.

Adult↗

PubMed1992

Longitudinal neurophysiologic studies in a patient with metachromatic leukodystrophy following bone marrow transplantation.

We describe a girl with late infantile metachromatic leukodystrophy. The patient has been followed up with serial neurologic and neurophysiologic examinations for 8 years following bone marrow transplantation, which she underwent when she was 4 3/4 years old. Her older sister died from metachromatic leukodystrophy at the age of 8 years, whereas our patient has retained significant cognitive and motor skills. Serial neurophysiologic studies initially demonstrated continued deterioration after the bone marrow transplantation, but since then, most results have remained stable or improved. Although, to our knowledge, there have been no previous serial studies of metachromatic leukodystrophy, individual case studies suggest that these findings in our patient are very unusual. With the advent of possible treatment for this condition, there is a need for further serial neurophysiologic studies to characterize the natural progression and the possible detection of progression or reversal with treatment.

Action Potentials↗

PubMed1992

[Bradyarrhythmias secondary to the use of ophthalmic timolol. A report of 3 cases].

Three cases of symptomatic bradycardia due to topical ocular timolol administration are reported. Two patients had syncope related to atrioventricular block, and the other one complained of dizziness due to sinus bradycardia. Heart disease was not present in any case, although a right bundle branch block was observed in one patients. A normal sinus rhythm resumed in all patients after discontinuation of timolol.

Aged↗

PubMed1992

[Spontaneous remission in a patient with long-term idiopathic dilated myocardiopathy].

The case of a patient with long-term idiopathic dilated cardiomyopathy, functional class IV, very depressed left ventricular ejection fraction (13%) and history of severe dyspnea for more than four years, who experienced an spontaneous clinical and hemodynamic recovery (functional class I, left ventricular ejection fraction 51%) while being on waiting list for heart transplantation is reported. The patient remains in good clinical condition after a follow-up of two years.

Cardiomyopathy, Dilated↗

PubMed1991

Both cell surface and internalized beta-adrenoceptors are reduced in the failing myocardium.

To study myocardial beta-adrenoceptor internalization in heart failure, we measured beta-adrenoceptor density in the particulate, light vesicle and supernatant fractions of ventricular tissue of dogs with experimental right ventricular failure and sham-operated dogs. Tissue was fractionated by centrifugation, and beta-adrenoceptors were measured by [125I]iodocyanopindolol binding. Compared to sham-operated controls, beta-adrenoceptors were reduced in all fractions of right ventricular tissue from heart failure animals. Thus, the decreased surface (particulate fraction) receptors observed cannot be explained by internalization alone, and must be associated with altered receptor synthesis or degradation.

Animals↗

PubMed1991

[Cough caused by angiotensin-converting enzyme inhibitors. A series of cases collected by spontaneous notification of adverse reactions].

Cough is one of the possible untoward adverse drug effects of angiotensin converting enzyme inhibitors. We describe the available information on 50 cough episodes attributable to captopril and 18 episodes attributable to enalapril reported to the Spanish Drug Surveillance System. Cough represented 37% and 39% of the reports of side effects of captopril and enalapril, respectively. There was a remarkable female predominance among the patients with cough. Cough developed at very low doses (15 mg of captopril and 5 mg of enalapril daily), although the patients on captopril who developed cough were receiving higher doses than those who presented other side effects. A high proportion of patients (29%) continued with the drug for more than six months after cough had developed, suggesting the need for a wider knowledge of this side effect.

Aged↗

PubMed1991

P300 brain activity in seizure patients preceding temporal lobectomy.

Event-related potentials were recorded over occipital and parietal scalp from 20 patients suffering from intractable partial complex seizures prior to undergoing a temporal lobectomy. Subjects were presented with language and nonlanguage visual stimuli using a divided-field, "odd-ball" paradigm. Although behavioral performance (button-press accuracy, reaction time, and running counts) was comparable across all groups (although accuracy was worse for those in the left temporal group), patients showed tremendous variability in both the amplitude and latency of the P300 response. Particularly notable was the observation that more slow wave activity was present among the patients than among the control subjects, and those scheduled for a left temporal resection evinced more amplitude reduction than those scheduled for a right temporal resection. In addition, a number of patients appeared not to show a P300 response at all. These results are discussed in the context of the utility of using noninvasive event-related potential measures to examine both memory impairment and the integrity of the neural structures that mediate memory functioning in certain patient populations.

Adult↗

PubMed1991

Status epilepticus: clinical experience with two special devices for continuous cerebral monitoring.

Continuous cerebral monitoring (CCM) was performed on 34 patients in status epilepticus (SE), using changes in amplitude detected by the cerebral function monitor (CFM) and changes in frequency detected by compressed spectral array (CSA). The EEG was used intermittently to help identify seizure patterns obtained with these methods. Seventeen patients in clinically manifest SE also had non-convulsive seizures. In 17 patients, SE was refractory to conventional anticonvulsants, requiring treatment with pentobarbital or paraldehyde. In these patients, CCM provided dynamic electroencephalographic monitoring of burst-suppression and prompt detection of breakthrough seizures. Patients in SE should undergo CCM to differentiate between non-convulsive seizures and post-ictal state both of which may produce prolonged unresponsiveness following clinical seizures. CCM after data reduction with the two special devices used is a viable and practical alternative to continuous conventional EEG monitoring during SE. However, in order to evaluate the sensitivity and specificity of these methods, it will be necessary to design a study in which both the EEG and the devices using data reduction be used continuously and concurrently.

Adolescent↗

PubMed1991

The prognostic value of residual spikes in the postexcision electrocorticogram after temporal lobectomy.

We correlated the postresection electrocorticograms (ECoGs) of 80 patients who underwent temporal lobectomy under general anesthesia for treatment of intractable complex partial seizures with surgical results in three groups: seizure/aura free (32 patients), auras only (16 patients), and one or more postoperative seizures (32 patients) at mean follow-up times of 34, 31, and 38 months, respectively. Spontaneous "residual spikes," ie, present after all resections, were present in 47% of patients who had no postoperative seizures or auras. However, they occurred in 72% of patients with any postoperative seizures (p less than 0.05). The location (convexity, mesial, or edge of resections) or the distribution (unifocal versus multifocal) of the residual spikes was not of prognostic value. Quantitative studies in 5-minute epochs of the postexcision ECoGs did not reveal a significant difference in the morphology of the residual spikes, ie, the amplitude or firing pattern (single versus polyspike), in the three groups. The group with postoperative seizures showed a higher number of spikes per epoch (greater than or equal to 50), but it was not significant. Although the study shows that patients with residual spikes may have good prognosis, they are at significantly higher risk for postoperative seizures as compared with those without residual spikes. The possibility that intensity of firing of residual spikes may be an additional predictor of outcome warrants further study.

Cerebral Cortex↗

PubMed1991

Intraoperative monitoring of the facial nerve during decompressive surgery for hemifacial spasm.

In 11 consecutive patients, intraoperative electromyographic (EMG) recordings were made from the facial muscles during microvascular decompression for hemifacial spasm. In one patient, recordings could not be obtained for technical reasons, and two patients had no abnormality. In the remaining eight patients, the abnormal response resolved before decompression in two, resolved immediately at the time of decompression in five, and failed to resolve in one. All patients were relieved of their hemifacial spasm. In the five patients whose abnormalities resolved at the time of decompression, there was a precise intraoperative correlation between decompression of the nerve and disappearance of the abnormal EMG response. In three cases, this was a useful guide to the need to decompress more than one vessel. These results confirm the findings of Møller and Jannetta, support the use of this technique for intraoperative monitoring of facial nerve decompression procedures, and provide strong circumstantial evidence that vascular cross-compression is an important etiological factor in hemifacial spasm.

Electromyography↗

PubMed1990

The lateralization of language comprehension using event-related potentials.

Event-Related Potentials were recorded over occipital and parietal scalp from left- and right-handed adults presented with a language and a non-language visual stimulus using a divided field, "oddball" paradigm. The major finding of interest was that the P300 component was larger over the left than the right hemisphere of the right-handers when the language stimulus was presented to the left hemisphere; there were no hemispheric differences for the left-handers, regardless of field of presentation. These results are discussed in the context of developing noninvasive measures to lateralize language function.

Arousal↗

PubMed1990

Serial epilepsy caused by levodopa/carbidopa administration in two patients on hemodialysis.

Two patients with similar clinical features are presented: both patients had chronic renal failure, on hemodialysis for many years but recently begun on a high-flux dialyzer; both had been receiving a carbidopa/levodopa preparation; and both had the onset of hallucinosis and recurrent seizures, which were refractory to anticonvulsants. The first patient died without a diagnosis; the second patient had a dramatic recovery following the administration of vitamin B6. Neither patient was considered to have a renal state sufficiently severe enough to explain their presentation.

Aged↗

PubMed1988

Postprandial blood pressure changes during hemodialysis.

The effect of eating on BP during hemodialysis was examined in nine nondiabetic end-stage renal disease (ESRD) patients. A standard meal was given during 62 of 125 dialysis treatments in a prospectively controlled study. Diastolic (P = 0.01) and mean (P = 0.03) BPs fell significantly faster in the 45-minute postprandial period in the fed treatments compared with equivalent times in the fasting treatments. In this period, symptomatic hypotension occurred 13 times in five patients fed during dialysis compared with two episodes in one patient while fasting (P less than 0.05). Consumption of meals during hemodialysis should be avoided in patients at risk for hypotension during treatment.

Adult↗