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Biomedical subjects

J Bolaños

Publications and source records attributed to J Bolaños.

At least 19 recordsLinked to original sources
PubMed2002

Effects of copper on hatching of larvae and prezoea survival of Petrolisthes galathinus (Porcellanidae): assays with ovigerous females and isolated eggs.

Ovigerous females of the porcellanid crab Petrolisthes galathinus were selected for toxicological bioassays. A first assay was made on isolated eggs, exposing them to 0 (control), 0.5, or 1 mgL(-1) copper. Both copper concentrations caused significant mortality just before hatching. The few prezoeas hatched at 0.5 and 1 mgL(-1) were unable to reach the zoea stage. A second assay was conducted on the ovigerous females isolated and exposed to 0 or 0.1 mgL(-1) copper. Females were checked daily and the percentages of mortality, egg loss, and hatching larvae were recorded. No differences in either mortality of females or number of hatched larvae were noted between control and copper-exposed groups. From each of these groups, 15 recently hatched prezoeas were transferred to clean seawater, while another 15 were exposed to 0.1 mgL(-1) copper. The numbers of dead or alive prezoeas, transitional larvae, and zoeas were ascertained every 24 h. Prezoeas hatched from exposed eggs and transferred to clean seawater at hatching showed enhanced mortality and a delay in development, compared with control larvae maintained in clean water throughout. Copper at 0.1 mgL(-1) was lethal to almost all larvae exposed only after hatching, while those that had also been preexposed to copper during embryonic development showed a certain degree of tolerance to copper exposure, at least during the first 24 h after hatching.

Animals↗
PubMed2001

Discordant CD4 T lymphocyte responses to antiretroviral therapy for HIV infection are associated with ex-vivo rates of apoptosis.

Our purpose was to determine if changes in CD4 cell counts in HIV-infected patients with good viral suppression on stable antiretroviral regimens could be predicted by ex-vivo rates of apoptosis of peripheral blood mononuclear cells (PBMC). Patients were grouped by lowest pre-treatment and highest on-treatment CD4 cell counts and classified as complete immune responders, partial responders, or non-responders. Whole blood was collected from a subgroup of patients and controls, and rates of the ex-vivo apoptosis of PBMC were assessed. Non-responders exhibited significantly increased apoptosis, whereas good immune responses were associated with decreased apoptosis. Persistently accelerated apoptosis may contribute to persisting immune deficiency independent of the viral load.

Adult↗
PubMed2001

Survival and molting of the pea crab larvae Tunicotheres moseri Rathbun 1918 (Brachyura, Pinnotheridae) exposed to copper.

The acute lethal toxicity of copper, as well as its sublethal effect on molting, was studied on larval and postlarval stages of the pinnotherid crab Tunicotheres moseri. The most sensitive stage was zoea I, presenting a significant mortality above 0.5 microg x L(-1). Abnormal setation of the maxillipeds was observed in zoeae II moulted from zoeae I exposed to 100 microg x L(-1) and higher copper concentrations, causing a reduced swimming activity of the larvae. This pathology could be reverted after molting of affected zoea II to megalopa, which would be the first report in crustacean larvae that states the possibility of reverting morphological abnormalities after molting. For zoeae II and megalopae, the inhibition of molting and high mortality was registered at 1,000 microg x L(-1). The effect of copper on the duration of the larval and postlarval stages was differential: It retarded the duration of the stage zoea I, did not modify that of zoea II, and accelerated the ecdysis of the megalopae to first crab. However, precocious molting to megalopae was associated with a smaller body size at the concentration of 100 microg x L(-1). This differential effect of copper on the larval stages throughout the larval development could be ecologically relevant. Because of their lecithotrophia, their short developmental period, their good survival in control conditions, and the high sensitivity showed to copper (especially zoea I), larvae of T. moseri have shown that they are an excellent model for studying the effect of pollutant on survival, molting rate, growth, and morphogenetic changes during development.

Animals↗
PubMed2000

Diffuse axonal injury with or without an evacuated intracranial hematoma in head injured patients. Are they different lesions?

The general classification of head injury proposed by Marshall et al., based on admission CT scan findings, might mask a group of patients who have Diffuse Brain Injury (DI) in addition to intracranial haematomas. The aim of this study was to assess possible differences in outcome with respect to the level of intracranial pressure (ICP) and cerebral perfusion pressure (CPP) between a group of patients with DI: III-IV (Marshall's classification) after the evacuation of an intracranial haematoma (group A) and another group with DI: III-IV in the absence of a mass lesion (group B). We prospectively studied 129 patients with isolated and closed severe head injury (GCS < 9). In group A (n = 61), the median percentage of hours with ICP > 20 mmHg and CPP < 70 mmHg was 42.8 and 18, respectively and 17 (28%) survived with GOS 4-5. In group B (n = 68), median values of 20 and 5.5 hours were obtained for ICP > 20 and CPP < 70 respectively, whilst 39 (57.3%) survived with favourable outcomes. When we analysed the effects of the DI: III-IV in both groups of patients, we found that the differences in percentage of time with ICP > 20 and CPP < 70 were statistically significant (p < 0.01) and patients in group A had a higher morbidity and mortality (p < 0.05). This study has demonstrated that the levels of ICP, morbidity and mortality in patients with DI: III-IV and an evacuated mass lesion were higher than in patients with DI: III-IV without a mass lesion.

Adolescent↗
PubMed1999

Prognostic value of early computerized tomography scanning following craniotomy for traumatic hematoma.

OBJECT: Patients with head injuries traditionally were categorized on the basis of whether their lesions appeared to be diffuse, focal, or mass lesions on admission computerized tomography (CT) scanning. In the classification of Marshall, et al., the presence of a hematoma (evacuated or not evacuated) is more significant than any diffuse injury (DI). The CT scan appearance after evacuation of a mass lesion has not been analyzed previously in relation to outcome. The authors have investigated the importance of: 1) neurological assessment at hospital admission; 2) the status of the basal cisterns and associated intracranial lesions on the admission CT scan; and 3) the degree of DI on the early CT scan obtained after craniotomy to identify patients at risk for development of raised intracranial pressure (ICP) and lowered cerebral perfusion pressure (CPP) and to discover the influence of the postoperative CT appearance of the lesion on patient outcome. METHODS: The authors prospectively studied 82 patients with isolated, severe closed head injury (Glasgow Coma Scale [GCS] score < or = 8), all of whom had intracranial hematoma. Both ICP and CPP were continuously monitored, and a CT scan was obtained within 2 to 12 hours after craniotomy. The CT images were categorized according to the classification of Marshall, et al. The mortality rate during the hospital stay was 37%, and 50% of the patients achieved a favorable outcome. Compression of the basal cistern on the admission (preoperative) CT scan was associated with raised ICP and a CPP of less than 70 mm Hg but not with any other features or with poor patient outcome. In 53 patients the postoperative CT scan revealed DIs III or IV and 29 patients had DIs I or II. The percentages of time during the hospital stay in which ICP was higher than 20 mm Hg and CPP was lower than 70 mm Hg as well as unfavorable outcome were higher in the group of patients in whom DI III or IV was present (p < 0.001). Raised ICP, CPP lower than 70 mm Hg, DI III or IV, and unfavorable outcome were more frequently observed in patients who presented with a motor (m)GCS score of 3 or less, bilateral unreactive pupils, associated intracranial injuries, and hypotension (p < 0.001). When logistic regression analysis was performed, an mGCS score of 3 or less (p = 0.0013, odds ratio [OR] 10.8), bilateral unreactive pupils (p = 0.0047, OR 31.8), and DI III or IV observed on CT scanning after surgery (p = 0.015, OR 8.9) were independently associated with poor outcome. CONCLUSIONS: Features on CT scans obtained shortly after craniotomy constitute an independent predictor of outcome in patients with traumatic hematoma. Patients in whom DI III or IV appears on postoperative CT scanning, who often present with an mGCS score of 3 or less and nonreactive pupils, are at high risk for the development of raised ICP and lowered CPP.

Adolescent↗
PubMed1996

Comparison of bronchoscopic diagnostic techniques with histological findings in brain dead organ donors without suspected pneumonia.

BACKGROUND: The techniques for recognising pneumonia in mechanically ventilated patients were evaluated as no "gold standard" is available to establish the diagnosis in these patients. METHODS: A prospective study was performed on nine brain dead organ donors not suspected of having pneumonia to assess the specificity of bacteriological results from different samples by comparing them with the histological findings from an open pulmonary biopsy specimen taken immediately after death through a mini-thoracotomy. RESULTS: Seven of the nine organ donors without clinical evidence of pulmonary infection and not on antibiotic therapy showed histological features of bronchopneumonia. There was no association between the histological findings and quantitative cultures of the lung biopsy specimen. CONCLUSIONS: Histological evidence of pneumonia was common in this group of ventilated patients who had no clinical signs of the disease.

Adult↗
PubMed1995

Removal of infected dual chambered transvenous pacemaker and implantation of a new epicardial dual chambered device with cardiopulmonary bypass: experience with seven cases.

Seven patients with infected transvenous dual chambered pacemakers have undergone removal of the device using cardiopulmonary bypass. There were four women and three men with a mean age of 58 years. Six patients had localized infection in the generator pocket (mean of 4.6 previous unsuccessful operations for surgical sterilization). Four infections were due to Staphylococcus epidermidis, two to Staphylococcus aureus, and one patient presented septicemia caused by Staphylococcus epidermidis and Pseudomonas aeruginosa. The atrial and ventricular transvenous electrodes were removed under direct vision using cardiopulmonary bypass. A new dual chambered epicardial pacemaker was implanted. The procedure was well-tolerated, and all patients are infection free with working pacemakers after a mean follow-up of 25.4 months.

Cardiopulmonary Bypass↗
PubMed1995

[Children's accidents treated at health centers].

OBJECTIVES: To find the characteristics of accidents to children treated at our Health Centres. DESIGN: A descriptive crossover study. SETTING: Almanjayar and Cartuja Health Centres, Granada. PATIENTS: The 0 to 14 age-group treated at our centres because of an accident. MEASUREMENTS AND MAIN RESULTS: The number of accidents to children treated at our health centres during 1994 was 217. The most common accidents were, in descending order: falls, 27%; burns, 20.7%; traffic accidents, 17%; poisoning, 15%; inhalation of foreign bodies, 10.5%; bites and aggressions, 9.2%. 48.3% of the accidents occurred at home, 37.7% in the street and 13.8% at school. In the relation of type of accident to age group, we found that burns affected children under 5 to a greater extent. Poisoning was more common between 5 and 9. Traffic accidents and falls affected children between 10 and 14 more. The relationship between age and type of accident is significant (p < 0.005). There is no significant connection between gender and type of accident. CONCLUSIONS: Age and some types of accident are directly related. The majority of accidents tend to occur at home and in the street. We consider that prevention is the best way of decreasing accidents to children. Programmes involving children, parents and teachers should be set up.

Accident Prevention↗
PubMed1994

Effect of alpha-interferon on erythrocyte and hepatocyte plasma membranes derived from cirrhotic rats.

Interferons are recognized to inhibit collagen production. Since fibrosis has been associated with liver dysfunction, we investigated the effects of alpha-interferon on the function and lipid composition of hepatocyte and erythrocyte plasma membranes derived from CCl4-cirrhotic male Wistar rats. In both cell types, CCl4 decreased Na+/K+ and Ca(2+)-ATPase activity and increased the cholesterol to phospholipids (CH/PL) ratio (p < 0.05). Administration of interferon (80,000 IU/kg s.c. for 8 weeks) increased survival from 40 to 90%, and preserved normal ATPase activity and CH/PL ratio. Our results show that administration of alpha-interferon to CCl4-cirrhotic rats improves survival, and liver and erythrocyte membrane function and composition, probably as a result of its antifibrogenic effect.

Animals↗
PubMed1993

The spatial location of EEG electrodes: locating the best-fitting sphere relative to cortical anatomy.

The location of the international 10-20 system electrode positions and 14 fiducial landmarks are described in cartesian coordinates (+/- 1.4 mm average accuracy). Six replications were obtained on 3 separate days from 4 normal subjects, who were compared to each other with a best-fit sphere algorithm. Test-retest reliability depended on the electrode position: the parasagittal electrodes were associated with greater measurement errors (maximum 7 mm) than midline locations. Location variability due to head shape was greatest in the temporal region, averaging 5 mm from the mean. For each subject's electrode locations a best-fitting sphere was determined (79-87 mm radius, 6% average error). A surface-fitting algorithm was used to transfer the electrode locations and best-fitting sphere to MR images of the brain and scalp. The center of the best-fitting sphere coincided with the floor of the third ventricle 5 mm anterior to the posterior commissure. The melding of EEG electrode location information with brain anatomy provides an empirical basis for associating hypothetical equivalent dipole locations with their anatomical substrates.

Adult↗
PubMed1992

[Dehydroepiandrosterone sulfate and lipids in acute myocardial infarct].

To establish the possible relationship between acute myocardial infarction (AMI) and dehydroepiandrosterone-sulfate (DHEA-S) in a group of 15 patients with AMI, blood levels of DHEA-S and certain lipids (total cholesterol, LDL-cholesterol, HDL-cholesterol and triglycerides) were determined at admission in the hospital and after 10 days. As controls a group of healthy individuals or with minor diseases, and a group of 24 severely ill non-cardioischaemic patients have been studied. DHEA-S and HDL-cholesterol levels have been found significantly lowered both in patients with AMI (at 10th day) as well as in the severely ill non-cardioischaemic patients, in comparison with the healthy volunteers group. We conclude, then, than the lowering in DHEA-S and HDL-cholesterol seems not to be specifically relates with AMI but has a certain relationship with severe disorders in general.

Aged↗
PubMed1991

Stress-induced gastroduodenal lesions and total parenteral nutrition in critically ill patients: frequency, complications, and the value of prophylactic treatment. A prospective, randomized study.

OBJECTIVE: To assess the frequency, complications, and value of prophylactic treatment of stress-induced gastroduodenal lesions. DESIGNS: Patients were prospectively randomized to treatment with total parenteral nutrition, either alone, with sucralfate, or with ranitidine. SETTING: A multidisciplinary ICU from a tertiary care referral center. PATIENTS: Ninety-seven patients submitted to prolonged mechanical ventilation, with normal hepatic and renal function, in metabolic stress, and receiving total parenteral nutrition. INTERVENTIONS: On admission, we determined the Acute Physiology and Chronic Health Evaluation II score and the catabolic index score. We also performed an endoscopic examination on day 3, every 7 days subsequently, and whenever needed. Thirty patients received total parenteral nutrition alone. Twenty-four patients received total parenteral nutrition and sucralfate (1 g by nasogastric tube every 4 hrs). Nineteen patients received total parenteral nutrition and ranitidine (50 mg iv every 6 hrs). MAIN RESULTS: The overall occurrence rate of gastroduodenal mucosal damage was 29.6%. The overall frequency rate for stress ulcerations was 15.6% and was 6.2% for stress hemorrhage. There were no deaths secondary to stress hemorrhage. The difference in the frequency of stress-induced mucosal lesions and stress hemorrhage between the studied groups was not statistically significant. CONCLUSIONS: Additional prophylaxis to total parenteral nutrition in the form of sucralfate and ranitidine to prevent acute upper gastrointestinal bleeding is not required in this group of ICU patients.

Adolescent↗
PubMed1991

[Evaluation of nutritional status in patients admitted to an internal medicine department. Study of 100 cases].

We have confirmed that malnutrition is very frequent in hospitalized patients. There is no agreement about which are the indexes or criteria agreement about which are the indexes or criteria that can be used to define malnutrition, specially in early stages. In the present work, we have studied 100 patients randomly chosen amongst the admissions that occurred in the Internal Medicine Department over a period of one year. The patients were submitted to a protocol which included the following: anthropometric measurements, seric proteins and routine determinations (sugar level, cholesterol, uric acid, etc.) It has been considered as malnourished those patients who presented some marker with a value lower than 90% of the standard value. According to these criteria, 25 of them had a caloric-protein malnutrition, 24 had a proteic malnutrition and 25 of them had mixed malnutrition. The most sensible parameters had been the triceps skin fold and retinal transporting protein.

Adolescent↗