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Biomedical subjects

L Coelho

Publications and source records attributed to L Coelho.

At least 19 recordsLinked to original sources
PubMed2005

C-reactive protein as a marker of infection in critically ill patients.

A prospective, observational study was conducted in a medico-surgical intensive care unit to assess the value of C-reactive protein (CRP), temperature and white cell count (WCC) measurements for the diagnosis of infection in critically ill patients. CRP, temperature and WCC were monitored daily in 76 infected and 36 non-infected patients. Multiple receiver-operating characteristics (ROC) curves were used to compare each parameter for infection diagnosis. The area under the curve (AUC) of CRP was significantly higher than that of temperature (0.93 and 0.75, respectively; p < 0.001). A CRP concentration of >8.7 mg/dL and a temperature of >38.2 degrees C were associated with infection, with a sensitivity of 93.4% and 54.8%, and a specificity of 86.1% and 88.9%, respectively. The ROC curve of WCC showed a poor diagnostic performance. The combination of CRP and temperature increased the specificity for infection diagnosis to 100%. In the subgroup of patients with ventilator-associated pneumonia (n = 48), CRP measurements were more reliable than temperature (AUC 0.92 and 0.78, respectively; p 0.006). The CRP levels in infected patients with sepsis, severe sepsis and septic shock were 15.2 +/- 8.2, 20.3 +/- 10.9 and 23.3 +/- 8.7 mg/dL, respectively (p 0.044). It was concluded that CRP was a better marker of infection than temperature. However, the combination of CRP and temperature measurements further increased the specificity for infection diagnosis, even in the subgroup of patients with VAP.

Adult↗
PubMed2005

C-reactive protein as a marker of ventilator-associated pneumonia resolution: a pilot study.

The aim of this study was to evaluate C-reactive protein (CRP) levels, body temperature and white cell count (WCC) after prescription of antibiotics in order to describe the clinical resolution of ventilator-associated pneumonia (VAP). A cohort of 47 VAP patients with microbiological confirmation of disease was assessed. CRP levels, body temperature and WCC were monitored daily. On day 4 of the antibiotic therapy, the CRP level of survivors was 0.62 times the initial value, whereas, in nonsurvivors, it was 0.98. Body temperature and WCC remained almost unchanged. By day 4, a CRP of >0.6 times the initial level was a marker of poor outcome (sensitivity 0.92; specificity 0.59). Patients were divided according to their CRP patterns of response to antibiotics: fast response, slow response, nonresponse, and biphasic response. All patients with fast and slow response patterns survived, whereas those showing nonresponse and a biphasic response pattern exhibited a mortality of 78 and 75%, respectively. The adequacy of the initial antibiotic therapy had a marked influence on the rate of CRP decrease, as well as on mortality. In conclusion, daily C-reactive protein measurements after antibiotic prescription were useful in the identification, as early as day 4, of ventilator-associated pneumonia patients with poor outcome. The identification of the pattern of C-reactive protein response to antibiotics was useful in the recognition of individual clinical course, improving or worsening, as well as of the rate of improvement.

Aged↗
PubMed2002

Additive host genetic factors influence fecal egg excretion rates during Schistosoma mansoni infection in a rural area in Brazil.

This study quantifies the influence of shared household and kinship on egg counts during Schistosoma mansoni infection in a sample from rural Brazil. Detailed genealogic information allowed assignment of 597 individuals to 6 multihousehold pedigrees residing in 145 households. A variance component method was used to partition egg counts into shared household, additive genetic, and individual-specific environmental effects. Host additive genetic effects consistently accounted for a large proportion of the variation in egg counts: 43% in an unadjusted model and 40% in model adjusted for covariates. In a model that examined the confounding of shared household with kinship, additive genetic effects still accounted for 27% of the variation in egg counts and shared household only 12%. The consistently important role for host additive genetic factors on the variation in egg counts points to new ways of modeling and understanding the mechanisms that contribute to trait variation during infection with S. mansoni.

Animals↗
PubMed2001

Opportunities on the Web: a role for information professionals, using the development of the BMA Library Online Service as a case study.

The paper considers how attributes and skills fundamental to the information profession may be applied to the development and management of Web-based services and resources. It also looks at the need for the acquisition of new skills as part of a continuing professional development programme. The report considers the changing role of the Webmaster and the implications this might have in terms of the role of information professionals. To offer a practical example, from within the healthcare sector, the article goes on to describe the development of BMA Library Online. This is the BMA Library's own suite of Web-based information services and resources for personal members, institutional members and staff. The library's own Web team has been responsible for the development and maintenance of BMA Library Online. To conclude, the paper looks forward to future possibilities for information professionals as Web developers and at how this might be influenced by changes in the Webmaster role. It is crucial that skills and expertise are shared as the roles that go to make up a Webmaster or Webmaster team continue to merge and evolve, and with the possible wider distribution of provision of Web content within organizations.

Information Management↗
PubMed2001

Autonomic function in chronic liver disease assessed by Heart Rate Variability Study.

BACKGROUND: Chronic liver disease is associated with cardiovascular changes, including hyperdynamic circulation with increased blood volume and cardiac output, and with reduced peripheral vascular resistance. Autonomic dysfunction is a common finding in these patients, being involved in the pathogenesis of the hyperdynamic condition. The aim of our study was to evaluate autonomic function in cirrhotic patients by using the 24 hour Heart Rate Variability study. We also sought to relate the degree of autonomic dysfunction with the severity of the liver disease. MATERIAL AND METHODS: We studied 22 cirrhotic patients, 50% of whom were male, mean age 44.14 +/- 11.32 years. The etiology was alcohol related in 12 (54.6%), virus hepatitis in 6 (27.2%), autoimmune related in two (9.1%) and other in the remaining two (9.1%). In terms of severity liver disease 6 patients were in Child-Pugh's class A (27.3%), 9 in Child-Pugh's class B (40.9%) and 7 in Child-Pugh's class C (31.8%). Thirteen patients (59%) had ascites. Both patients and 20 age-sex matched healthy volunteers underwent 24 hour ECG Holter study with assessment of Heart Rate Variability (time and frequency domains). RESULTS: The cirrhotic patients showed severe decrease in Heart Rate Variability when compared to healthy volunteers: SDNN (84.14 +/- 35.78 ms vs 148.9 +/- 33.97 ms; p < 0.0001), pNN50 (3.54 +/- 4.61 vs 11.17 +/- 9.88; p = 0.004). The spectral analysis revealed markedly decrease of average total power, with reduction of all components (VLF, LF, HF), in the absence of significant difference in LF/HF ratio (2.52 +/- 1.40 vs 2.98 +/- 1.57; p = NS). Ascites had relationship with more pronounced autonomic impairment: SDNN (70.31 +/- 30.32 ms vs 104.11 +/- 34.97 ms; p = 0.03). On the other hand, alcohol related etiology did not influence Heart Rate Variability parameters. Moreover, we found significant positive correlations between SDNN (dependent variable) and Prothrombin activity (r = 0.64; p = 0.001), as well as with Serum Albumin (r = 0.40; p = 0.05), but not with Total Bilirubin (r = -0.14; p = 0.51). Prothrombin activity was the only independent predictor of autonomic dysfunction. CONCLUSION: Chronic liver disease is accompanied by a significant Heart Rate Variability decrease. Alcohol related etiology does not indicate further autonomic dysfunction. The greater the hepatopathy severity, the greater the Heart Rate Variability impairment. Hepatocellular dysfunction indicators have more accuracy to demonstrate autonomic disturbances than cholestasis indicators.

Adult↗
PubMed2001

[Mitral flow propagation velocity assessed with M-mode color Doppler in patients with dilated cardiomyopathy].

BACKGROUND: The role of diastolic disfunction in the setting of severe left ventricular (LV) disfunction is usually forgotten due to difficulties in quantification and interpretation. The propagation velocity (PV) of mitral inflow into the left ventricle has been proposed as a load independent indicator of LV diastolic function. Our aim was to correlate PV with age, body surface, chambers dimensions, wall thickness and with classic parameters of systolic and diastolic function. We had in mind the validation of this index in the quantification of LV filling and in risk stratification of patients with dilated cardiomyopathy (DC). MATERIAL AND METHODS: We prospectively studied 32 consecutive patients, mean age 56.1 +/- 15.7 years, 22 (68.75%) male, mean ejection fraction 28.1 +/- 7.5%. All of them were in NYHA class < or = II and on ACE inhibitors. Eight (25%) were on beta-blockers. Patients without sinus rhythm, paced or with significant hypertensive, congenital or valvular heart disease were previously excluded. The following parameters of LV systolic function were assessed by echocardiography: fractional shortening, ejection fraction and cardiac output. LV filling was assessed by transmitral flow pulsed Doppler analysis: isovolumic relaxation time (IVRT), peak E and A wave velocities, E wave deceleration time (DT). We also evaluated a new Doppler index of combined systolic and diastolic myocardial performance (Tei index). PV (cm/s) was calculated by Color M-mode. Univariate regression analysis was performed (PV as dependent variable). RESULTS: We detected a high prevalence of diastolic function disturbances: 25 (78.1%) patients with a delayed relaxation pattern and only 3 (9.4%) with a restrictive pattern. PV did not correlate with age, body surface and LV geometry. There was a significant correlation between PV and E/A ratio (r = 0.61; p < 0.0001), IVRT (r = -0.50; p = 0.006), DT (r = -0.41; p = 0.01) and Tei index (r = -0.36; p = 0.04). CONCLUSIONS: Our results indicate that, in patients with a predominance of delayed relaxation, there is a strong relationship between PV and the classic parameters of LV filling. For similar levels of systolic impairment, PV could be an easy, fast and reproducible quantitative indicator of severity on DC.

Cardiomyopathy, Dilated↗
PubMed2000

[Transient cortical blindness after cardiac catheterization in a post-surgical coronary patient].

Transient cortical blindness is a known complication after cerebral and vertebral angiography although is a rare complication following cardiac catheterization. In this report, we describe a seventy-six-year-old male patient who had cortical blindness after coronary bypass graft angiography. The development of cortical blindness, in this setting, appears to be an osmotic disruption of the blood-brain barrier which is selective for the occipital cortex. Other hypotheses, such as an immunological reaction to the contrast agent or a direct injection of dye into the vertebral artery system, were considered. The clinical outcome is usually favourable, with vision completely restored within 24-48 hours, as was the case of the patient described in the present report.

Aged↗
PubMed2000

Repolarization abnormalities after catheter ablation of differently located overt accessory pathways.

PURPOSE: Electrical repolarization abnormalities are usually seen after radiofrequency catheter ablation in overt accessory atrio-ventricular pathways. These abnormalities have been recognised as "cardiac memory". The aim of this study was to assess the relationships between electrical repolarization abnormalities and the location of the accessory atrioventricular pathway in the atrio-ventricular junction. We also assessed the relationship between electrical repolarization abnormalities and the degree of ventricular preexcitation. MATERIAL AND METHODS: Our group consisted of 45 patients with overt and persistent preexcitation who were successfully submitted to radiofrequency catheter ablation. Mean age was 38.9 +/- 14.9 years (14 to 64), 28 of whom (62.2%) were male and 17 (37.8%) female. The location of accessory pathways the was left lateral in 14 patients, right posteroseptal in 14 patients, right mesoseptal in eight patients, right anteroseptal in four patients and other locations in the remaining four. Surface electrocardiograms were performed immediately following ablation, 24 hours later and three or more months after the procedure. RESULTS: T wave abnormalities (flattened, inverted or peaked) were detected on the first day in 51% of patients, being more frequent after right accessory pathway ablation (86.9% versus 13.1% in left accessory pathways). These electrocardiographic changes were particularly frequent in patients with right mesoseptal (5/8, 62.5%) and posteroseptal (13/14, 93.3%) pathways, of which 62.5% and 71.5%, respectively, showed marked preexcitation before ablation. These findings were significantly different from those observed in patients with left lateral pathways--only 35.7% showed marked preexcitation and only two of fourteen patients (14.3%) presented T wave abnormalities after ablation. After the third month, most of the patients that had undergone successful ablation presented completed electrocardiographic normalization. CONCLUSIONS: Patients undergoing radiofrequency catheter ablation for right accessory pathways show more frequently repolarization abnormalities than those submitted to ablation of the left lateral accessory pathways. The occurrence of these changes after preexcitation resolution may depend on the degree of previous preexcitation.

Adolescent↗
PubMed2000

[Isolated non-compaction of left ventricular myocardium].

Noncompaction of the ventricular myocardium, also known as "spongy myocardium", is a rare congenital abnormality resulting from an arrest in the normal endomyocardial embryogenesis. The echocardiographic findings consist of multiple, prominent myocardial trabeculations and deep intratrabecular recesses in communication with the left ventricular cavity. This entity is a not well known cause of dilated cardiomyopathy. Some cases were described as X-linked familial forms. We report the clinical case of a 13-year-old female patient with severe left ventricular disfunction, a very trabeculated left ventricle on echocardiography and two admissions in class IV heart failure.

Adolescent↗
PubMed2000

Permanent pacing in patients with congenital atrio-ventricular block--experience of 33 cases.

OBJECTIVES: The authors review permanent pacing in patients with congenital atrioventricular block (CAVB) and present their experience in permanent pacing in this pathology. STUDY POPULATION AND METHODS: In a population of 4,355 patients submitted to implantation of permanent pacing between January 1980 and January 1998, 33 (0.75%) had CAVB. The mean age of the patient population with CAVB was 16.7 years (aged from eleven days to 35 years); 33% were below 10 years of age; 16 patients were male. The majority of the patients had symptoms of brain hypoperfusion; two patients had concomitant malignant ventricular tachyarrythmias (one of these with Torsade de Pointes due to congenital long QT syndrome). Transvenous (endocardial) pacing was used in 32 patients (two with previous epicardial pacing and exit block) and epicardial pacing in one. The mode of stimulation used was VVI in three patients, DDD in eight patients, VVIR in 14 patients, DDDR in four patients and VDD in four. Smaller pulse generators were used in children of lower weight. In recent years single lead VDD systems have been preferred whenever technically possible. Vascular access was the left cephalic vein in 17 patients; the left subclavian vein in 14 patients and the right jugular vein in one patient. During a mean follow-up of 6.9 years, two patients with ventricular stimulation systems developed "Pacemaker Syndrome" and required a change of mode of stimulation. Lead fracture and posterior cutaneous necroses were observed in two other patients, who were accordingly submitted to surgical revision. It was deemed necessary, one year later, to increase the lead loop in a child with a permanent pacemaker implanted at eleven days of age. No other complications occurred with the other patients; replacement of the pulse generators was performed in an elective manner. CONCLUSIONS: CAVB is a rare indication for the implantation of a permanent pacemaker. In children, in the majority of cases, endocardial stimulation is possible in spite of the obvious technical difficulties due to low weight. Sequential, more physiological, stimulation systems should be preferred. However, VVIR stimulation systems of smaller dimensions can be the first choice of mode of stimulation in smaller children, mainly due to anatomical and technical limitations.

Adolescent↗
PubMed1999

Ropivacaine 0.25% compared with bupivacaine 0.25% by the caudal route.

We compared in a randomized double-blind study, the postoperative analgesia and degree of motor block produced by the new local anaesthetic ropivacaine, with bupivacaine, for caudal anaesthesia in children. Eighty children, 2-5-years-old, ASA I, received one of two local anaesthetics; either ropivacaine 0.25% (1.0 ml x kg(-1)) or bupivacaine 0.25% (1.0 ml x kg(-1)). They were sedated with a continuous infusion of propofol (200 microg x kg(-1) min(-1). The lungs were ventilated with a mixture of 50% nitrous oxide with oxygen. 60 min after local anaesthetic injection, and every 60 min, the extent of the motor block in the recovery room was scored as 1-3, according to a modified Bromage scale. Adverse events and the time to the first analgesic requirement were reported. Patients in the two groups did not differ with respect to age, weight and height. There were no differences in heart rate and arterial pressure between the two groups(P>0.05). No adverse events were observed. The ropivacaine group showed a shorter duration of motor block than the bupivacaine group (P<0.05). The first postoperative analgesic requirement was a mean (sd) of 5 h+/-4.32 after the operation in the ropivacaine group and 5 h+/-3.81 for the bupivacaine group. These findings suggest that caudal anaesthesia with ropivacaine 0.25% in paediatric patients can be effective, with less motor blockade in the postoperative period.

Amides↗
PubMed1998

Caudal anaesthesia with 0.375% ropivacaine or 0.375% bupivacaine in paediatric patients.

We have determined the effectiveness and degree of motor block produced by the new local anaesthetic, ropivacaine, when used for caudal anaesthesia in children. We studied 60 children, aged 3-6 yr, ASA I, allocated randomly in a double-blind manner, to receive one of two local anaesthetics: 0.375% ropivacaine 1.0 ml kg-1 or 0.375% bupivacaine 1.0 ml kg-1. Patients were anaesthetized with continuous infusion of propofol 200 micrograms kg-1 min-1. The lungs were ventilated with 50% nitrous oxide in oxygen. Heart rate and arterial pressure were measured every 5 min after administration of local anaesthetic until discharge from the recovery room. The extent of motor block in the recovery room was scored as 1-3. Adverse events and time to first analgesic requirements were recorded. Patients in the two groups did not differ in age, weight or height. There were no differences in heart rate or arterial pressure between the two groups. No adverse events were observed. The degree of motor block was significantly different between the two groups. The ropivacaine group showed a shorter duration of motor block than the bupivacaine group (P < 0.05). Postoperative analgesia was required at a mean time of 5 (SD 3.2) h in the ropivacaine group compared with 5 (2.8) h in the bupivacaine group. These findings suggest that caudal anaesthesia with ropivacaine in paediatric patients is effective and produces less motor block in the postoperative period.

Amides↗
PubMed1998

Defensive ink pigment processing and secretion in Aplysia californica: concentration and storage of phycoerythrobilin in the ink gland.

The marine snail Aplysia californica obtains its defensive ink exclusively from a diet of red seaweed. It stores the pigment (phycoerythrobilin, the red algal photosynthetic pigment, r-phycoerythrin, minus its protein) in muscular ink-release vesicles within the ink gland. Snails fed a diet of green seaweed or romaine lettuce do not secrete ink and their ink-release vesicles are largely devoid of ink. Successive activation of individual ink-release vesicles by ink motor neurons causes them to secrete approximately 55 % of their remaining ink (similar to the percentage of ink reserves released from the intact gland). The peripheral activation of vesicles appears to be cholinergic: 70 % of isolated vesicles were induced to squeeze ink from their valved end by solutions of acetylcholine at concentrations of 0.5 mmol l-1 or below. Ultrastructural analysis commonly found three cell types in the ink gland. The RER cells, the most numerous, were characterized by an extensive rough endoplasmic reticulum with greatly distended cisternae. This cell type is probably the site for synthesis of the high molecular mass protein of secreted ink. The granulate cells, less common than RER cells, had nuclear and cell areas significantly larger than those of RER cells. In addition, granulate cells of red-algal-fed snails had 4-14 vacuoles that contained electron-dense material with staining characteristics similar to that of ink in mature ink-release vesicles. The granulate cell's plasma membrane was regularly modified into grated areas, which both localized and expanded the surface area for coated vesicle formation and provided a sieve structure that prevented large particles in the hemolymph either from being taken up by, or from occluding, the coated vesicles. Electron-dense particles within coated vesicles were similar in size to those in granulate vacuoles but larger (on average by approximately 1 nm) than those that make up the ink. In green-seaweed-fed snails, granulate cells and their vacuoles were present but the vacuoles were empty. The third cell type, the vesicle cell, expands markedly, with its nucleus enlarging concurrent with cell growth until it is on average 50 times larger in cross-sectional area than the nuclei of either RER or granulate cells; the cytoplasm eventually becomes filled with ink, which obscures the mitochondria, vacuoles and nucleus. Continued cell expansion ceases with the appearance of an encircling layer of muscle and 1-3 layers of cells of unknown origin, thereby becoming the ink-release vesicle itself. The absorption spectra of the soluble contents of mature ink-release vesicles from snails fed red algae had peaks characteristic of the red algal pigment r-phycoerythrin or/and phycoerythrobilin. Immunogold localization of r-phycoerythrin showed no statistical difference in the amount of label within the ink-release vesicles, RER or granulate cell types. Furthermore, there was no localization of phycoerythrin immunoreactivity within the various cellular compartments of either the RER or granulate cells (nucleus, endoplasmic reticulum, mitochondria, vacuoles). Immunogold labeling in the ink gland ranged from 11 to 16 % of that for the digestive vacuoles of the rhodoplast digestive cells lining the tubules of the digestive gland. Our observations suggest (a) that the main form of the ink pigment in the gland is phycoerythrobilin or/and a non-antigenic form of phycoerythrin, and (b) that separation of the bilin from phycoerythrin (or its modification so that it is no longer antigenic) occurs before it reaches the ink gland, probably within the vacuoles of the rhodoplast digestive cells of the digestive gland. We propose the following model. The ink pigment, phycoerythrobilin, is cleaved from its protein in rhodoplast digestive vacuoles in the digestive gland. (ABSTRACT TRUNCATED)

Animals↗
PubMed1998

Processing of defensive pigment in Aplysia californica: acquisition, modification and mobilization of the red algal pigment, r-phycoerythrin by the digestive gland.

The marine snail Aplysia californica obtains its purple defensive ink exclusively from the accessory photosynthetic pigment r-phycoerythrin, which is found in the red seaweeds of its diet. The rhodoplast digestive cell, one of three types of cell lining the tubules of the digestive gland, appears to be the site of catabolism of red algal chloroplasts (rhodoplasts) since thylakoid membranes, including phycobilisome-sized membrane-associated particles, were found within the large digestive vacuoles of this cell. Immunogold localization showed that there was a statistically significant occurrence of the red algal phycobilisome pigment r-phycoerythrin within these rhodoplast digestive vacuoles, but not in other compartments of this cell type (endoplasmic reticulum, mitochondria, nucleus) or in other tissues (abdominal ganglion). Immunogold analysis also suggested that the rhodoplast vacuole is the site for additional modification of r-phycoerythrin, which makes it non-antigenic: the chromophore is either cleaved from its biliprotein or the biliprotein is otherwise modified. The hemolymph had spectrographic absorption maxima typical of the protein-free chromophore (phycoerythrobilin) and/or r-phycoerythrin, but only when the animal had been feeding on red algae. Rhodoplast digestive cells and their vacuoles were not induced by the type of food in the diet: snails fed green seaweed and animals fed lettuce had characteristic rhodoplast cells but without the large membranous inclusions (rhodoplasts) or phycobilisome-like granules found in animals fed red seaweed. Two additional cell types lining the tubules of the digestive gland were characterized ultrastructurally: (1) a club-shaped digestive cell filled with electron-dense material, and (2) a triangular 'secretory' cell devoid of storage material and calcium carbonate. The following model is consistent with our observations: red algal rhodoplasts are freed from algal cells in the foregut and then engulfed by rhodoplast digestive cells in the tubules of the digestive diverticula, where they are digested in membrane-bound vacuoles; r-phycoerythrin is released from phycobilisomes on the rhodoplast thylakoids and chemically modified before leaving the digestive vacuole and accumulating in the hemolymph; the pigment then circulates throughout the body and is concentrated in specialized cells and vesicles of the ink gland, where it is stored until secreted in response to certain predators.

Journal Article↗
PubMed1998

[Congenital afibrinogenemia].

The authors present a case of congenital afibrinogenemia. A review of the literature is made, and some aspects of this rare inherited coagulation disorder are suggested and commented on.

Afibrinogenemia↗
PubMed1989

Gossypol affects the responsiveness of isolated rat myometrium and vas deferens.

The effects of gossypol on responsiveness of both rat myometrium and vas deferens were analyzed. In myometrial strips, gossypol (1-30 microM) produced rightward displacements of the cumulative concentration-response curves to acetylcholine, bradykinin and oxytocin, accompanied by reductions in maximal responses. Gossypol (30 microM) also completely abolished the contractions induced by field stimulation of the rat vas deferens. The IC50 values for gossypol against agonist-induced myometrial contractions and field-stimulated vas deferens contractions were similar, ranging between 13 and 18 microM. These results provide additional evidence that gossypol exerts a direct and irreversible inhibition of the contractility of both male and female reproductive organs.

Acetylcholine↗