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Biomedical subjects

J Castillo

Publications and source records attributed to J Castillo.

At least 163 records · Page 9Linked to original sources
PubMed1997

[Mortality due to traffic accidents in Chile, 1994: an epidemiological approach].

BACKGROUND: Traffic accidents are one of the most important public health problems in the world and produce social, work and human resources losses. AIM: To perform an epidemiological description of traffic accidents occurred in Chile during 1994. MATERIAL AND METHODS: Data were obtained from death certificates in which the cause of death was a traffic accident. All death certificates obtained by the National Institute of Statistics during 1994 were used. Social, demographic and seasonal variables were recorded. RESULTS: During 1994, there were 1679 deaths due to traffic accidents (81% male), with a rate of 19.6 per 100,000 inhabitants. Gender specific risks were 19.62 and 4.48 for men and women, respectively. Mean age at the moment of death was 39 years old. Fifty three percent of deceased people were single, 42% married and 5% widowers. Ten percent had no formal education, 48% had basic education, 23% college education and 6.5% university education. Seventy seven percent of fatalities occurred in urban areas. The risk of death by traffic accidents was 7.02 per 100,000 inhabitants in the metropolitan region. CONCLUSIONS: The information obtained in the present study may help to generate preventive strategies to control deaths caused by traffic accidents.

Accidents, Traffic↗
PubMed1996

Orthotopic liver transplantation from a donor with abdominal situs inversus.

The good results reported for liver transplantation have encouraged a much wider application of the procedure, broadening the list of indications and increasing the number of candidates. The shortage of organs for transplantation is a main problem that limits hepatic replacement in the potential recipients. Consequently, the number of contraindications for donor selection has been reduced over the last years. Some factors that were previously thought to preclude successful transplantation have now been relegated to relative contraindications, while others are no longer included. This has frequently led to the use of livers under suboptimal conditions or with anatomical anomalies. This is the case of donors with abdominal situs inversus. In this article, we report an orthotopic liver transplantation using a donor with abdominal situs inversus. Immunosuppressive protocol following surgery was composed of a classic three-drug therapy (cyclosporine, azathioprine, and prednisolone). The modified piggyback technique was performed over the right suprahepatic vein with orthotopic position of the graft. The graft showed good long-term function in the recipient, with a normal hepatic biopsy 5 months after the transplantation. There was no patient readmission or other medical problem after a 2 1/2-year follow-up.

Humans↗
PubMed1996

Nitric oxide production during the hyperacute vascular rejection.

A complete understanding of the biological mechanisms that take part in the hyperacute vascular rejection is necessary to prevent its development. Nitric Oxide (NO) release by the graft could be one of those mechanisms as cytokine induction of NO synthase in reticuloendothelial cells produces NO with cytotoxic activity. We have performed 20 heterotopic pig-to-dog kidney xenotransplantations in order to determine if cytotoxic NO is released during the hyperacute rejection. Nitrites and cGMP levels were determined in plasma samples taken from the graft artery and vein until vessel thromboses. NO synthase activity was measured in pieces from renal artery and renal tissue. The results show that after discordant xenotransplantation, inducible NO synthase is activated in the transplanted organ, indicating that NO can mediate host tissue damage during the hyperacute rejection.

Acute Disease↗
PubMed1996

Seasonality of cryptosporidiosis in children.

The seasonal distribution of cryptosporidiosis in children in Aragón, a region in northeastern Spain, was determined. Over a period of six years (October 1988 to September 1994), 10,034 stool samples from 4,508 children with gastrointestinal symptoms were analyzed for this purpose. The age of the patients ranged from 1 month to 14 years. Cryptosporidium oocysts were identified in 87 (1.93%) patients. Prevalence was highest (6.20%) in children aged 1 to 3 years old. The prevalence was significantly higher in the autumn-winter period (October to March) than in the spring-summer period (April to September) in the whole population (2.41% vs. 1.35%, p = 0.010) and in the 1- to 3-year-old age group (8.44% vs. 3.20%, p = 0.002), but not in the other age groups. A possible relationship of this pattern to attendance at child care centres is suggested.

Adolescent↗
PubMed1996

"Fast tracking" patients in an urban pediatric emergency department.

Modern health care reform emphasizes efficient resource and facility management and the need to develop strategies to direct patients with lower-acuity concerns away from the relatively cost-inefficient full-service pediatric emergency department (ED). This study examined a pediatric fast track system for triage accuracy and turnaround times. Egleston Children's Hospital is a regional, urban, tertiary-care academic center which is a major teaching affiliate of Emory University School of Medicine. The pediatric ED has an annual census of more than 30,000 patient encounters. During the 9-month period from December 1993 through August 1994, 2,243 lower-acuity patients were evaluated in the fast track section of the ED. Patients assigned to the fast track system maintained a quicker turnaround time than the aggregate of all patients seen in the ED (107 [95% CI 0, 245] minutes versus 149 [95% CI 0, 341] minutes, P < .01). Their total turnaround time was also less than that for patients with similar acuity levels seen during the hours that the fast track system was not in operation (120 [95% CI 0, 300 minutes], P < .01). Only 63 of the 2,243 (2.8%) patients assigned to fast track were found to have higher acuity levels than suspected at initial triage. In all cases they were appropriately cared for in the fast track area. The fast track system appears to be an effective method by which an urban pediatric ED can efficiently maintain patient flow in light of limited resources, space constraints, limited manpower, and an increasing census.

Academic Medical Centers↗
PubMed1996

Cerebrospinal fluid tyrosine and 3,4-dihydroxyphenylacetic acid levels in migraine patients.

We studied biochemical parameters related with central dopaminergic neurotransmission in migraine patients during crisis. We determined tyrosine and 3,4-dihydroxyphenylacetic acid (DOPAC) levels in cerebrospinal fluid (CSF) of 47 patients, 29 suffering migraine without aura and 18 suffering migraine with aura, comparing them with 27 control subjects. Tyrosine levels did not differ significantly between patients and controls. The CSF concentration of DOPAC was 0.73 +/- 0.55 ng/ml in the control population, 3.84 +/- 2.08 ng/ml in patients with migraine without aura and 3.30 +/- 1.49 ng/ml in patients suffering migraine with aura. The concentration of DOPAC correlated positively with the intensity of headache. These results suggest that patients with migraine have a central dopaminergic hyperfunction, probably related to a coexisting central dysfunction of noradrenergic neurotransmission.

3,4-Dihydroxyphenylacetic Acid↗
PubMed1996

Prolonged regional nerve blockade. Injectable biodegradable bupivacaine/polyester microspheres.

BACKGROUND: Biodegradable microspheres are a useful method of drug delivery because they are both injectable and biodegradable, eliminating the need for surgical implantation or removal. Previous work has characterized implantable preparations of local anesthetics in polymer pellets for prolonged regional anesthesia. In this article, the authors characterize injectable suspensions of bupivacaine-polymer microspheres and examine whether they can produce prolonged blockade of the sciatic nerve in rats. METHODS: Microspheres were prepared using polylactic-co-glycolic acid polymers loaded with 75% w/w bupivacaine by a solvent evaporation method. Bupivacaine release from microspheres was determined in vitro by ultraviolet spectroscopy and scintillation counting. Sensory and motor blockade of the rat sciatic nerve were assessed in vivo after injection of microsphere suspensions. RESULTS: Depending on the type of microspheres, the dose, and the additive used, mean duration of sciatic nerve block ranged from 10 h to 5.5 days. Incorporation of 0.05% w/w dexamethasone into the microspheres resulted in significant prolongation of block (up to 13-fold), and only preparations that contained dexamethasone produced blocks lasting beyond 1 day. Bupivacaine was released in a controlled manner in vitro. Dexamethasone does not substantially slow bupivacaine release from microspheres in vitro. CONCLUSIONS: Prolonged percutaneous blockade of peripheral nerves is feasible. The recovery from blockade is complete, and plasma bupivacaine levels are far below the range associated with systemic toxicity. The mechanisms underlying the dexamethasone block-prolonging effect are under investigation.

Anesthetics, Local↗
PubMed1996

Glucocorticoids prolong rat sciatic nerve blockade in vivo from bupivacaine microspheres.

BACKGROUND: Previous work showed that incorporation of dexamethasone (0.05 weight/weight percentage) into bupivacaine microspheres prolonged blockade by eight to 13 times compared with that produced by bupivacaine microspheres alone. The determinants of dexamethasone's block-prolonging effect were examined and reported here. METHODS: Polylactic-co-glycolic acid polymer microspheres (65/35) with 75 weight/weight percentage bupivacaine were prepared. Microspheres were injected adjacent to the rat sciatic nerve, and sensory and motor blockade were assessed. A procedure was developed to test drugs for block-prolonging ability in vivo by placing test drugs in the injection fluid along with a suspension of bupivacaine microspheres. RESULTS: Dexamethasone alone in suspension did not produce blockade, nor did it prolong blockade induced by aqueous bupivacaine. Bupivacaine microspheres (150 mg drug/kg rat weight) produced blockade for 6 to 10 h. Dexamethasone in the suspending solution of microspheres prolonged block by up to five times. Glucocorticoids prolonged block in proportion to glucocorticoid/antiinflammatory potency. The corticosteroid antagonist cortexolone inhibited dexamethasone's blockade-prolonging action. Durations of blockade with or without dexamethasone were unaltered by hydroxyurea-induced neutrophil depletion. Microspheres were extracted from rats at time points ranging from 7 h to 7 days, and residual microsphere dry weight and bupivacaine content were similar in groups of rats injected with either bupivacaine microspheres or bupivacaine microspheres containing dexamethasone, respectively. CONCLUSIONS: Glucocorticoids prolong blockade from bupivacaine microspheres. The mechanism appears unrelated to the kinetics of bupivacaine release in vivo.

Anesthetics, Local↗
PubMed1996

Neuroexcitatory amino acids and their relation to infarct size and neurological deficit in ischemic stroke.

BACKGROUND AND PURPOSE: The participation of excitatory amino acids (EAAs) in the pathogenesis of ischemic neuronal lesion has been experimentally demonstrated, but clinical experience is scarce. Our objective was to examine EAA levels during the acute phase of cerebral infarction in relation to infarct size and intensity of neurological deficit. METHODS: Using high-performance liquid chromatography, we determined the glutamate, aspartate, taurine, and glycine concentrations in the plasma and cerebrospinal fluid (CSF) of 128 patients with ischemic cerebral infarction confirmed by CT and 43 control subjects. Blood and CSF samples were obtained on admission within the first 24 hours from symptom onset. The severity of the neurological deficit was assessed with the Canadian Stroke Scale immediately after these tests and at 48 hours after inclusion in the study. Infarct volume was determined in a second CT performed between the 4th and 7th day after the patient's inclusion. RESULTS: The concentration of plasmatic glutamate was 121.39 +/- 80.89 mumol/L in the control group and 163.71 +/- 103.13 mumol/L in the patient group (P = .015); in CSF it was 3.46 +/- 1.20 mumol/L in control subjects and 6.55 +/- 4.65 mumol/L in patients (P < .0001). The concentration of glycine in plasma was 158.02 +/- 32.15 mumol/L in control subjects and 189.37 +/- 74.04 mumol/L in patients (P = .007); in CSF it was 6.18 +/- 2.28 mumol/L in control subjects and 11.23 +/- 6.96 mumol/L in patients (P < .0001). The concentrations of glutamate in plasma and in CSF were significantly higher in patients with large cerebral infarcts and in those with cortical infarcts. Levels of glutamate and glycine in plasma and CSF were significantly higher in patients with a higher degree of neurological deficit. CONCLUSIONS: Our results support the excitotoxic activity of glutamate and glycine in patients with cerebral infarction.

Adult↗
PubMed1996

Neck and brain transitory vascular compression causing neurological complications. Results of surgical treatment on 1,300 patients.

In this brief article we describe the role of compression of the vertebral subclavian arteries, internal mammary, internal carotid arteries, brachial plexus and coiling and kinking of the vertebral and basilar arteries, the faulty irrigation of blood supply and oxygen of the cerebellum and basal ganglia of the brain. Among the effects are: a decrease in the secretion of dopamine at the level of the putamen, which produces the symptoms of Parkinson's disease, and chorea due to chronic transitory faulty blood supply and oxygen to the caudate nucleus, ballism by hypoxia at the level of subthalamic nuclei and athetosis in the lenticular nucleus. This compression is caused by the anterior scalene muscles and the cervical ribs at the level of the vertebrae C6-C7; by the sternocleidomastoid at the level of the cervical atlas; and coiling and kinking of the vertebral, basilar and the internal carotid arteries. The decreased blood supply to the cerebellum and basal ganglia is the cause of the Cerebellar Thoracic Outlet Syndrome (CTOS) and its neurological complications, among which are ipsilateral paralysis, Parkinson disease and others. We are presently engaged in several studies to widen our understanding of this phenomenon.

Aged↗
PubMed1996

The use of valproate in an elderly population with affective symptoms.

BACKGROUND: Little is known about the efficacy and tolerability of valproate in the elderly population with affective disorders. This pharmacoepidemiologic study was undertaken to determine the side effect profile and efficacy of valproate in an elderly population with psychiatric symptomatology. METHOD: This was a retrospective chart review of all elderly inpatients at McLean Hospital who received valproate between May 8, 1989, and May 8, 1992. Charts were reviewed to determine gender, discharge diagnosis, indication for the agent, and length of time on each medication. Charts were also reviewed for abnormalities in liver function tests, blood cell dyscrasias, sedation, nausea and vomiting, weight gain, impairment of cognition, tremor, and hair loss. The efficacy of the medication was also determined. RESULTS: Thirty-five elderly subjects who suffered from an affective disorder and who had received valproate were identified. The mean age was 71.3 years. The mean length of time the patient received valproate was 32.7 days. The mean dose was 743 mg/day, and the mean blood drug level was 52.9 mg/L. The valproate was rated as efficacious in 18 (62%) of the 29 patients who had had an adequate drug trial at discharge. Overall the medication was well tolerated. There were no reports of liver function test abnormalities. One patient experienced transient leukopenia. Other adverse events included two reports of nausea, two reports of sedation, and one complaint of confusion. None of the variables examined were found to be statistically significant in regard to efficacy. CONCLUSION: Valproate was well tolerated and efficacious in this elderly population with affective disorders. Further controlled studies are needed to confirm our results.

Affective Disorders, Psychotic↗
PubMed1996

[Cerebral hemorrhage and migraine].

The connection between migraine and brain haemorrhage is controversial. We present the case of eight nonhypertense patients all aged under 57 with migraine antecedents who suffered brain haemorrhage during an attack. All underwent analytical study, chest X-ray, electrocardiography, computerized tomography scan and brain panangiography. The study was completed in six cases with an immunological analysis and in a further five with brain magnetic resonance. Seven patients habitually took vasoactive drugs to relieve migraine. The results do not show any other cause of brain haemorrhage. It is possible haemorrhage may be related to vascular lesion brought about by ischaemia secondary to vasospasms.

Adolescent↗
PubMed1996

[The prognostic value and evolution of blood pressure during an acute phase of stroke].

We studied the prognostic influence and evolution of blood pressure during the acute phase of stroke in 89 patients (50 men and 39 women) with an average age of 69.4 +/- 10.8 years. Seventy-two were diagnosed as having ischaemic infarct and 17 as having spontaneous intracerebral haemorrhage. Blood pressure was taken every four hours for twelve days. Clinical situation was evaluated using the Rankin scale. Systolic and diastolic blood pressure progressively decreased without needing any medication in the first two weeks of evolution. The decrease was greatest in hypertense patients and in those with left ventricle hypertrophy. We found the initial figures for systolic and diastolic blood pressure significantly higher in those patients with brain infarct who had not died and in those in a better functional position the second week of evolution. Blood pressure did not influence the prognosis of intracerebral haemorrhage patients.

Acute Disease↗
PubMed1996

[The prognostic value of analytical hemorheological factors in stroke].

Plasmatic hyperviscosity is a known vascular risk factor which depends, among other parameters, upon total proteins, haematocrit value and fibrinogen. The aim of this study was to determine the relationship between these analytical haemorrological parameters and mortality and acute stroke sickness rate. We studied 216 patients with brain infarct and spontaneous intracerebral haemorrhage out of a sample of 256 acute stroke patients. We evaluated neurological affectation using the Canadian scale upon admission, on the seventh day and after three months. We determined plasmatic haemorrological factors (haematocrit, fibrinogen and total proteins) upon admission and again after one week and then at three months High fibrinogen levels in plasma were related to brain infarct mortality regardless of the cause of death.

Adult↗
PubMed1996

[3 year survival in patients hospitalized for acute cerebrovascular disorders].

For three years we studied the mortality and functional situation of all patients admitted in 1991 to the Neurology Service suffering from acute stroke with the exception of subarachnoid haemorrhage cases. We analyzed the cause of death whether directly related to the initial illness or not. Out of 134 patients admitted for acute stroke, 48 (41.02% of the 117 patients examined after excluding 17 whom we did not obtain complete information from) had died after three years. The main causes of death were directly related to acute stroke (37.5%) and pneumonia (37.5%). Death occurred mainly in the first month (79.16% of deaths). Predictive variables for mortality directly related to acute stroke during the first month include severe weakness, brain haemorrhage, dysphasia and earlier incidence of acute stroke. Variables related to higher mortality rate due to other causes in the first month were dysphasia, age and angina antecedents, whereas earlier incidence of acute stroke was associated with a lesser mortality rate for these causes, as distinct from acute stroke itself. Greater levels of weakness and sphincteral incontinence are the best predictive signs of dependency functional situation at the end of the first month and, along with diabetes, after one and three years.

Acute Disease↗