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Biomedical subjects

L Castillo

Publications and source records attributed to L Castillo.

At least 55 records · Page 3Linked to original sources
PubMed1998

[Cerebral metabolic monitoring experience in critical neurological patients].

BACKGROUND: Cerebral metabolic monitoring in critical neurological patients allows the assessment of neuronal tissue response to injury and to plan the best therapy to correct each critical brain situation. AIM: To evaluate the usefulness of cerebral metabolic monitoring in patients with acute cerebral injury. PATIENTS AND METHODS: A retrospective analysis of 29 patients with acute brain injury, in whom a catheter was located in the bulb of the jugular vein to perform a cerebral metabolic monitoring. These patients were compared with others that were not subjected to this monitoring. The evolution at six months of follow up was assessed using the Glasgow outcome score, considering a favorable evolution when this score was 4 or greater. RESULTS: Patients with an hyperemic state on admission or after optimization of therapy did not have hospital mortality, and 73% had Glasgow outcome score of 4 or greater at six months of follow up. On the other hand, 50% of those with hypoperfusion or global ischemia died during hospitalization and 72% had a Glasgow outcome score of 3 or less at six months. Patients not subjected to cerebral metabolic monitoring behave as those with hypoperfusion or global ischemia. CONCLUSIONS: Cerebral metabolic monitoring is an useful tool to optimize the management of patients with acute cerebral injury, and those patients with an hyperemic cerebral state have the best prognosis.

Adolescent↗
PubMed1998

[Cardiac manifestations of primary hypothyroidism. Determinant factors and treatment response].

INTRODUCTION AND OBJECTIVES: Previous studies have not fully established the magnitude and determinant factors of cardiac manifestations of primary hypothyroidism. This study was aimed to assess the effects of thyroid deficiency on cardiac performance and structure. PATIENTS AND METHODS: We studied by echocardiography 19 patients with overt and 23 with subclinical hypothyroidism, and 21 control subjects. Patients were restudied one year after L-thyroxine therapy. Systolic function was assessed by the observed/predicted fractional shortening ratio. The predicted fractional shortening was calculated from the inverse relation of fractional shortening to end-systolic stress (p < 0.0001) in normal subjects. RESULTS: The observed/predicted fractional shortening ratio was lower (p = 0.043) and left ventricular mass was higher (p = 0.028) in overt hypothyroidism than in subclinical hypothyroidism and control subjects. By multivariate analysis, fractional shortening ratio was related to thyroxine levels (p = 0.0002), systemic vascular resistance (p = 0.0001) and age (p = 0.0009), and left ventricular mass was related to thyroxine levels (p = 0.0004) and weight (p = 0.0001). Pericardial effusion was observed in 37% of patients with overt hypothyroidism and 9% of patients with subclinical hypothyroidism (p = 0.03), and was mainly related to TSH levels (p = 0.0098). Hormone replacement therapy increased systolic function in overt hypothyroidism. Left ventricular mass did not change after therapy. Pericardial effusion disappeared in all patients. CONCLUSIONS: Primary hypothyroidism produces a decrease in myocardial contractility and an increase in left ventricular mass, both related to the severity of hormone deficiency. Pericardial effusion is mainly related to thyrotrophin plasma levels. Most of cardiac manifestations of hypothyroidism reverse with L-thyroxine therapy.

Adolescent↗
PubMed1997

[The obtaining of neural cell suspensions. Their application in neurobiological studies].

INTRODUCTION: Techniques of intracranial grafting have become powerful tools used in the study of the mechanisms of regeneration and plasticity taking place in the central nervous system (CNS). Suspensions of foetal neural cells have been successfully used as intracerebral grafts in deep regions of the brain. OBJECTIVE: The objective of this paper is to describe the methodology used by our group to obtain and prepare suspensions of cells from different parts of rat embryo brain (midbrain, striatum and septum) used for experimental transplants in animal models. MATERIAL AND METHODS: We give a detailed description of the steps involved in the preparation of tissue in the form of a suspension of cells. These steps include the obtention of tissue at the optimum stage of development, dissection of the donor tissue, enzymatic treatment and mechanical dissociation until a suspension of cells is obtained. Viability counts showed a high percentage (more than 95%) of viable cells in the suspensions thus obtained. Cellular viability is affected by different factors and is a prerequisite for good survival of the graft. CONCLUSION: The methodology described permits obtention of suspensions of foetal neural cells which are optimal for use in studies both in vitro and in experimental transplants.

Animals↗
PubMed1997

[Malignant nasosinusal melanomas. Review of the literature apropos of 12 cases].

Malignant melanoma with primary onset in the nasal cavity and paranasal sinuses remains a scarcely encountered malignancy and we report 12 cases of our own experience from 1991. These mucosal melanomas occur mainly in the elderly and present most commonly as a one sided airway obstructive syndrome with often bleeding in the nasal cavity. No sex or race ratio is found. Histological examination of the surgical specimen has been made easier since the use of immunohistochemical studies. The original site of onset is commonly located at the inferior part of the nasal cavity but in many cases, it is noted several sites of tumor localization. Despite well conducted treatment the prognosis remains quite deceiving and significantly poor. In our study, the 4-year actuarial survival was 26%. The 5-year survival rate ranges in the literature from 10% to 40%. Short and long term follow-up show an important rate of recurrence (local and lymph node metastases as well as distant metastases). The insidious evolution of the malignancy usually happens during the first year. Computed tomography and MRI are essential in the evaluation of tumor extension. The treatment is based on the combination of surgery and radiotherapy: Surgery is practised first and must ensure sufficient excision of the tumor without minimal functional or aesthetic damage in this complex region. This surgery is based on surgical approaches to the midface known as Lateral rhinotomy and midfacial degloving. When there is cervical lymph node involvement at the time of diagnosis it is suitable to treat it, even in case of recurrence. Complementary high dose radiation is required to treat tumors which could not undergo surgery and also as adjuvant therapy after removal of the mass.

Aged↗
PubMed1997

Analysis of retinoic acid receptor beta expression in normal and malignant laryngeal mucosa by a sensitive and routine applicable reverse transcription-polymerase chain reaction enzyme-linked immunosorbent assay method.

Retinoic acid receptor beta (RAR-beta) seems to be a useful intermediate marker in trials of retinoids, and the aim of this work was to describe a fast, sensitive, and routine applicable method to measure RAR-beta expression in tumor biopsies. We developed a new technique combining reverse transcription-PCR with a colorimetric ELISA detection of amplification products. The principle of this nonradioactive method is based on digoxigenin labeling of PCR products during amplification. Amplified DNA is hybridized with a biotinylated capture probe. The generated hybrid is immobilized on a streptavidin-coated microtiter plate, and detection is performed with the use of an antidigoxigenin peroxidase conjugate. We applied this method to quantify the expression of RAR-beta and an internal control (beta2 microglobulin) in laryngeal tumors. We found a detection threshold at 50 pg of PCR products, which represents a 100-fold improvement when compared to the detection limit of ethidium bromide detection. The method was reproducible (intra- and interassay reproducibilities at 7 and 5%, respectively). We used this technique for determining RAR-beta expression in 20 patients with laryngeal carcinoma and in 20 patients without cancer. The data show that the value of the RAR-beta:beta2 microglobulin ratio is decreased in tumoral versus nontumoral specimens (P = 0.0012), which is consistent with previously published results.

Adult↗
PubMed1996

Whole body nitric oxide synthesis in healthy men determined from [15N] arginine-to-[15N]citrulline labeling.

The rates of whole body nitric oxide (NO) synthesis, plasma arginine flux, and de novo arginine synthesis and their relationships to urea production, were examined in a total of seven healthy adults receiving an L-amino acid diet for 6 days. NO synthesis was estimated by the rate of conversion of the [15N] guanidino nitrogen of arginine to plasma [15N] ureido citrulline and compared with that based on urinary nitrite (NO2-)/nitrate (NO3-) excretion. Six subjects received on dietary day 7, a 24-hr (12-hr fed/12-hr fasted) primed, constant, intravenous infusion of L-[guanidino-15N2]arginine and [13C]urea. A similar investigation was repeated with three of these subjects, plus an additional subject, in which they received L-[ureido-13C]citrulline, to determine plasma citrulline fluxes. The estimated rates (mean +/- SD) of NO synthesis over a period of 24 hr averaged 0.96 +/- 0.1 mumol .kg-1.hr-1 and 0.95 +/- 0.1 mumol.kg-1.hr-1, for the [15N]citrulline and the nitrite/nitrate methods, respectively. About 15% of the plasma arginine turnover was associated with urea formation and 1.2% with NO formation. De novo arginine synthesis averaged 9.2 +/- 1.4 mumol. kg-1.hr-1, indicating that approximately 11% of the plasma arginine flux originates via conversion of plasma citrulline to arginine. Thus, the fraction of the plasma arginine flux associated with NO and also urea synthesis in healthy humans is small, although the plasma arginine compartment serves as a significant precursor pool (54%) for whole body NO formation. This tracer model should be useful for exploring these metabolic relationships in vivo, under specific pathophysiologic states where the L-arginine-NO pathway might be altered.

Adult↗
PubMed1996

[Adequacy of the pharmacologic treatment to the recommendations of a performance protocol in hypercholesterolemia in primary care].

OBJECTIVE: To evaluate whether hypolipaemiant treatment in patients with hypercholesterolaemia (HC) corresponds to the recommendations in a primary care diagnosis and treatment protocol. DESIGN: Descriptive observational study. SETTING: Primary care centre. PATIENTS: 304 patients whose long-term prescription records recorded hypolipaemiant drugs. RESULTS: Average age was 62.7 and 198 were women. 176 presented simple HC and 125 mixed dyslipaemia. 46 had a history of ischaemic cardiopathy. Pre-treatment LDL-cholesterol (LDL-c) was recorded for 224; 168 of them had 2 or more cardiovascular risk factors. Of the 202 who had a record of post-treatment LDL-c, 163 were at level III of risk, which went down to 47 at 6 months. The values before and after medication were as follows: total cholesterol (TC) 290.3 mg/dl and 246.2 mg/dl; LDL-c 207.8 mg/dl and 166.0 mg/dl; HDL-cholesterol 50.5 mg/dl and 53.1 mg/dl; and triglycerides (TG) 156.1 mg/dl and 133.6 mg/dl. Mean reduction of TC and LDL-c was greater in the patients treated with statins that in those treated with fibrates. Decrease in TG was greater with fibrates. CONCLUSIONS: Treatment was initiated when LDL-c figures were over the limit specified in the protocol. In most cases this was because of the accumulation of cardiovascular risk factors.

Adult↗
PubMed1996

Twenty-four-hour intravenous and oral tracer studies with L-[1-13C]phenylalanine and L-[3,3-2H2]tyrosine at a tyrosine-free, generous phenylalanine intake in adults.

The daily rates of whole-body phenylalanine oxidation and hydroxylation were determined in young men receiving [1-13C]phenylalanine and [2H2]tyrosine via primed, constant intravenous (n=3) or oral (n=5) infusion for 24 consecutive hours (12-h fast followed by 12-h fed period), and given a generous phenylalanine (100 mg.kg-1.d-1), tyrosine-free, but otherwise adequate L-amino acid-based diet for 6 d before the tracer study. Our hypothesis was that subjects would be in whole-body phenylalanine equilibrium. Estimates of the daily rates of phenylalanine oxidation (phe-ox) and hydroxylation (phe-OH) were significantly higher for the subjects receiving the oral compared with intravenous tracer (P<0.01 for both comparisons), with the estimates of phe-ox obtained with oral tracer during the 12-h fast period being close to those predicted from similar 24-h leucine kinetic studies. The precision of the agreement between the measured 24-h rates of phe-ox and phe-OH compared with the predicted daily rates by extrapolation from the last hour of the 12-h fast and fifth hour of the fed period was poor. From the 24-h data, daily phenylalanine balances were estimated to be positive for both the intravenous and oral tracer protocols, although it was less positive for the oral tracer group. These results imply that the [13C]phenylalanine probe underestimated whole-body irreversible loss of phenylalanine, and suggest that daily phenylalanine balance in earlier 24-h phenylalanine-tyrosine tracer studies at low phenylalanine intakes may have been overestimated. Studies involving [13C]tyrosine as tracer will be required to further assess whole-body aromatic amino acid balance.

Administration, Oral↗
PubMed1996

A two-dimensional electrophoretic analysis of latex peptides reacting with IgE and IgG antibodies from patients with latex allergy.

Latex proteins from nonammoniated natural rubber latex were investigated for their reactivity with antibodies in the sera of patients with spina bifida and health care workers with allergy to latex. Immunoblots of two-dimensional electrophoresis were used to compare the reactivity of various polypeptides against IgE, IgG, and subclasses of IgG. A total of 79 polypeptides showed reactivity with IgG and IgE antibodies from different patients. IgG showed reactivity with all the 79 polypeptides, while IgE reacted with 56 allergens. IgG2 reacted with the least number of proteins, while IgG4 reacted with the largest number of polypeptides. Several antigens were identified as significant due to their reactivity with antibodies in latex-allergic patients. Four proteins reacted with IgE, IgG1, IgG3 and IgG4 of only spina bifida patients with latex allergy, while one other protein reacted only with health care workers. Thus, these relevant latex peptides may be isolated, purified, and used in various assays for more reliable diagnosis of latex allergy.

Adolescent↗
PubMed1996

[Extracorporeal respiratory assistance. Experience in the treatment of severe acute respiratory failure].

Acute respiratory distress syndrome (ARDS) secondary to systemic injury has a high mortality. Symptomatic treatment with mechanical ventilation, PEEP and high levels of inspired oxygen is effective for most of the patients. When ventilatory support fails in reversing hypoxemia, extracorporeal respiratory assistance has been advocated as a temporary treatment until lung repair occurs. We described our experience in eleven patients (9M, 2F, 41 +/- 16 yo) with severe ARDS refractory to conventional treatment and expected to die if not assisted with extracorporeal oxygenation. All patients required invasive monitoring; seven needed continuous renal therapy because of concurrent renal failure. Venous-venous percutaneous cannulation and systemic anticoagulation were performed and extracorporeal oxygenation and CO2 removal started with blood pump flows of 20 to 30% of patient cardiac output. Improved oxygenation and decreased CO2 levels were immediately observed in 10/11 patients. One patient failed to have reversal of hypoxemia because recirculation and died shortly after initiation of extracorporeal therapy. Plasma leak syndrome and bleeding were observed in 3 and 2 patients respectively. Extracorporeal assistance was maintained for 52 +/- 34 h (19-134). Five (45%) patients were weaned off the pump and two (18%) survived and were discharged. Despite the high cost, extracorporeal respiratory assistance, when applied to selected patients, can reverse hypoxia and may save some previously unsalvagable patients, allowing them to return to a normal life.

Acute Disease↗
PubMed1996

[Prolonged inhalation of nitric oxide in adult respiratory distress syndrome in a case].

Inhalation therapy with nitric oxide has been suggested as beneficial in the adult respiratory distress syndrome, however there are few reports of its prolonged use. We report a patient with a chronic lymphocytic leukemia that developed an adult respiratory distress syndrome with severe hypoxemia, refractory to conventional therapeutic measures, during the course of a septic shock. The patient received nitric oxide (19 ppm) improving arterial oxygen saturation and allowing the reduction of FiO2 to 40%. The patient died five days later due to a multiple organ failure.

Aged↗
PubMed1996

Arginine: new and exciting developments for an "old" amino acid.

Arginine (2-amino-5-guanidino pentanoic acid) was shown in 1895 by Hedin to be present in the proteins of horn. Metabolic nitrogen balance studies, conducted in 1957 by Rose in human adults and in 1959 by Snyderman and coworkers in young infants revealed that a dietary source of this amino acid was not an obligatory requirement for growth and maintenance of nitrogen homeostasis in healthy individuals. Hence, it was initially classified as a non-essential (dispensable) amino acid and, perhaps, for reasons of this classification arginine did not receive the earlier attention it now deserves, in relation to an understanding of the nutritional biochemistry and physiology of its metabolism in humans subjects. However, there is currently a considerable interest in the cellular and tissue functions, as well as clinical, therapeutic significance, of arginine. In this paper we review the multiple functions of arginine, including its role in the L-arginine-nitric oxide pathway, cellular regeneration, immune function, protein synthesis and protein breakdown. We then consider some in vivo aspects of the physiology of arginine metabolism, which varies greatly among eukaryotes, with particular reference to humans. Against this background, studies of arginine in the nutrition of humans under various pathophysiological conditions are reviewed briefly. Finally, a new, updated concept for the metabolic basis for the "conditional essentiality" of arginine is proposed.

Arginine↗
PubMed1996

[Systemic leptospirosis as a cause of multiple organ failure. Report of a case].

Leptospirosis is a world-spread zoonosis that is incidentally acquired by humans. It causes a diphasic febrile illness in which the Weil syndrome is its severest form, with renal, hepatic, clotting and central nervous system involvement. We report a 73 years old male, that was admitted to an intensive care unit with multiple organ failure due to leptospirosis. The clinical picture initially resembled a sepsis due to biliary tract obstruction and was operated, not finding a biliary tract obstruction. Considering the history of a fall to sewed waters, leptospirosis was suspected and treatment with penicillin was started, obtaining a full recovery of the patient.

Abdominal Pain↗
PubMed1996

Complications of endoscopically guided sinus surgery.

The authors reviewed a series of 553 consecutive patients who underwent endoscopically guided sinus surgery. Major complications occurred in six patients (2.2%). There was one death due to incorrect positioning of the frontal drain. One patient developed a cerebrospinal fluid leak which had to be closed with an osteomucosal graft. Two patients who developed severe bleeding after removal of the nasal packing, needed ligation of the sphenopalatine artery and the internal maxillary artery, respectively. Two patients developed a complete stenosis of the nasolacrimal duct, necessitating a dacryocystorhinostomy. Minor complications occurred in 36 patients (13.4%). These included damage to the lamina papyracea (n = 11), severe bleeding after removal of the nasal packing treated conservatively (n = 6), intranasal mucosal adhesions (n = 17), and atrophic rhinitis (n = 2). The aetiology, prevention and treatment of complications during and after sinus surgery are also discussed.

Adolescent↗