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Biomedical subjects

A Freire

Publications and source records attributed to A Freire.

At least 19 recordsLinked to original sources
PubMed2005

Independent patterns of damage within magno-, parvo- and koniocellular pathways in Parkinson's disease.

Sensory deficits have been documented in Parkinson's disease, in particular within the visual domain. However, ageing factors related to the brain and to neural and non-neural ocular structures could explain some of the previously reported results, in particular the claimed impairment within the koniocellular pathway. This study addressed visual impairment attributable to the magno- (luminance), parvo- (red-green) and koniocellular (blue-yellow) pathways in a population of Parkinson's disease patients. To avoid potentially confounding factors, all subjects underwent a full neurophthalmological assessment which led to exclusion of subjects with increased intraocular pressure, diabetes even in the absence of retinopathy, and ocular abnormalities (from a total of 72 patients' eyes, 12 were excluded). Both parvo- and koniocellular pathways were studied by means of contrast sensitivity (CS) measurements along protan, tritan and deutan axes and also by fitting chromatic discrimination ellipses using eight measured contrast axes. Magnocellular function was assessed, using stimuli that induce a frequency doubling illusion, in 17 locations in the fovea and periphery. Achromatic (luminance modulation) thresholds were significantly higher in Parkinson's disease both in foveal and peripheral locations. A significant impairment was observed along protan and deutan axes, but only marginally along the tritan axis. These results were corroborated by a significant elongation of chromatic discrimination ellipses in our Parkinson's disease group. Correlation analysis showed that achromatic and chromatic CS measures were independent, which implies that multiple visual pathways are affected independently in Parkinson's disease. Magnocellular impairment was significantly correlated with age and disease stage, in contrast to the measured chromatic deficits. We conclude that in Parkinson's disease, independent damage occurs in the early magno- and parvocellular pathways. Furthermore, traditional koniocellular probing strategies in Parkinson's disease may be confounded by ageing factors, which may reconcile the previously reported controversial findings concerning chromatic impairment in Parkinson's disease.

Aging↗
PubMed2003

Evaluation of two different oestrus-synchronisation methods with timed artificial insemination and resynchronisation of returns to oestrus in lactating Holstein cows.

To examine the outcomes of adding medroxyprogesterone acetate (MAP) to the ovsynch protocol with the traditional ovsynch protocol in both cycling and anoestrus cows, and to evaluate a resynchronisation protocol, 742 cows averaging more than 40 days postpartum were assigned to the following four treatments: (1) ovsynch (OVS): day 0: GnRH; day 7: PGF2alpha; day 9: a similar dose of GnRH; day 10: timed artificial insemination (TAI), approximately 16-20h later; (2) ovsynch+MAP (MAP): the same ovsynch protocol plus an intravaginal insert made of polyurethane sponge impregnated with 300mg of MAP immediately after the first GnRH treatment and on day 7, at the time of the PG treatment, the sponge was removed; (3) resynchronisation (MAP+ODB): 1mg of oestradiol benzoate (ODB) on day 13 after TAI and a new sponge impregnated with MAP was inserted and; on day 20, 1mg of ODB was given and the sponge removed; and (4) no resynchronisation (No MAP): only oestrus detection and AI at any repeat oestrus detected after TAI. Progesterone was measured in milk samples collected on days -17, -10, -3, 13 and 20 (TAI=day 0). Based on milk P4 at days -17 and -10, 27.4% of the cows were still anoestrus. At PG injection, 67.7% of the cycling and 21.3% of the anoestrus cows had elevated P4. Farm, days postpartum and parity variations were detected in both cases. On day 20 after TAI 42.6% of cycling and 8.3% of the anoestrous cows had elevated P4. Pregnancy rates were similar in both pre-breeding treatments (20%), but interactions (P<0.001) were detected between treatment and cycling activity (for anoestrous cows: MAP=34.9%; OVS=11.1%. Average interval from TAI to subsequent AI was 37+/-3 days. Resynchronisation resulted in more (P<0.001) cows in oestrus between days 18 and 25 after TAI. Conception rate in the MAP+ODB treatment was lower (P<0.05) than the No MAP group (22.8% versus 47.4%). It was concluded that the addition of a progestin to the ovsynch protocol resulted in increased pregnancy rates of cows treated during anoestrus. The benefit of including MAP with the ovsynch protocol for cycling cows is equivocal.

Administration, Intravaginal↗
PubMed2001

Face recognition in 4- to 7-year-olds: processing of configural, featural, and paraphernalia information.

We tested 4- to 7-year-old children's face recognition by manipulating the faces' configural and featural information and the presence of superfluous paraphernalia. Results indicated that even with only a single 5-s exposure to the target face, most children could use configural and feature cues to make identity judgments. Repeated exposure and experimenter feedback enabled other children to do so as well. Even after attaining proficiency at identifying the target face, however, children's recognition was impaired when a superfluous hat was added to the face. Thus, although young children can process featural and configural face information, their memories are highly susceptible to disruption from superfluous paraphernalia.

Age Factors↗
PubMed2000

Clinical and economic impact of a pharmacist-intervention to promote sequential intravenous to oral clindamycin conversion.

A multicentre, prospective, controlled study compared the clinical efficacy, safety and economic impact of a pharmacist intervention to promote sequential intravenous to oral clindamycin conversion. A total of 473 patients receiving intravenous clindamycin for at least 72 hours were included in the study. Two groups were established: an intervention group (204 patients) in which an informative sheet recommending the sequential treatment was provided, and a control group (269 patients). Clindamycin was prescribed for respiratory infections in 38.9% and for prophylaxis in surgery in 25.4% of the patients (71% were contaminated surgery). No difference between groups regarding sex, infection severity, health status or clinical progress was observed. Both the step-down treatments after 72 hours of intravenous clindamycin and the change to the oral route later on, were significantly increased with the intervention (p < 0.001, p < 0.001 respectively). No significant differences between both groups were found in the number of patients with adverse effects associated with the i.v. therapy, although the incidence tended to be lower in the intervention group (49/204 intervention versus 85/269 control, p = 0.07). Compliance with the recommended clindamycin dosing regimen was significantly higher in the intervention group, in which 1.3 days reduction of intravenous therapy provided an average cost savings of PTA5246 (95% CI 2556-7935) per treatment. A higher reduction of 1.7 days was achieved in those patients candidates for switch therapy on the third day of intravenous clindamycin. A sequential program with clindamycin may provide a cost-effective alternative to conventional therapy and the introduction of an information sheet is a cost-effective strategy to promote it.

Administration, Oral↗
PubMed2000

The face-inversion effect as a deficit in the encoding of configural information: direct evidence.

We report four experiments leading to conclusions that: (i) the face-inversion effect is mainly due to the deficits in processing of configural information from inverted faces; and (ii) this effect occurs primarily at the encoding stage of face processing, rather than at the storage stage. In experiment 1, participants discriminated upright faces differing primarily in configuration with 81% accuracy. Participants viewing the same faces presented upside down scored only 55%. In experiment 2, the corresponding discrimination rates for faces differing mainly in featural information were 91% (upright) and 90% (inverted). In experiments 3 and 4, the same faces were used in a memory paradigm. In experiment 3, a delayed matching-to-sample task was used, in which upright-face pairs differed either in configuration or features. Recognition rates were comparable to those for the corresponding upright faces in the discrimination tasks in experiments 1 and 2. However, there was no effect of delay (1 s, 5 s, or 10 s). In experiment 4, we repeated experiment 3, this time with inverted faces. Results were comparable to those of inverted conditions in experiments 1 and 2, and again there was no effect of delay. Together these results suggest that an 'encoding bottleneck' for configural information may be responsible for the face-inversion effect in particular, and memory for faces in general.

Face↗
PubMed1999

Effects of face configuration change on shape perception: a new illusion.

We report two experiments indicating that varying the configuration of face features changes perception of an oval aperture windowing the face: as the eyes and mouth of a frontal-view face photograph are moved vertically toward face boundaries, the oval appears increasingly clongated, taller, and narrower; when eyes and mouth are moved toward the nose, the oval appears increasingly rounder, shorter, and wider. This shape illusion is maximised when faces appear upright within the oval and major face features (eyes, nose, and mouth) appear in their correct relative locations. These results establish that processing of a face configuration can affect perception of a geometric shape that shares visual space with a face. Whether the illusion is face-specific or a special case of a more general geometric illusion is discussed.

Face↗
PubMed1998

[Secondary stroke prevention].

The guidelines for secondary stroke prevention, graded following available scientific evidence, are presented. Stroke and TIA are defined and the indications for referral established. Basic assessment of stroke patients should include laboratory evaluation, ECG, brain CT, ultrasound examination of the extracranial vessels for events in the carotid distribution, and transthoracic or transesophageal echocardiogram if cardioembolism is suspected. The pharmacological and non-pharmacological reduction of blood pressure and serum cholesterol, stopping smoking and reducing alcohol intake are general measures recommended for secondary stroke prevention, together with healthier life-style changes (eating a Mediterranean type diet and performing regular moderate physical exercise). Concerning antithrombotic therapy, oral anticoagulants are recommended for patients with atrial fibrillation and other high to medium emboligenic cardiac risk conditions. Antiplatelet drugs are recommended for all other survivors of an ischemic cerebral event. Aspirin (75-325 mg/day) is the drug of choice. Alternative antiplatelet agents are clopidrogrel, ticlopidine, dipiridamol or triflusal. They can be used in patients with intolerance or contraindication to aspirin or in high-risk subjects. Endarterectomy of the symptomatic carotid is an additional procedure recommended for patients with ischemic stroke or TIA and carotid stenosis > 80% on the side of the symptomatic cerebral hemisphere.

Anticoagulants↗
PubMed1996

Biochemical and biological characterization of Ecuadorian pitviper venoms (genera Bothriechis, Bothriopsis, Bothrops and Lachesis).

The lethality and enzymatic activities of venoms from six Ecuadorian pitvipers (Bothriechis schlegelii, Bothriopsis punctata, Bothriopsis taeniata, Bothrops asper, Bothrops atrox and Lachesis muta) are similar to those of other South and Central American species, but with a few exceptions: Bothriopsis taeniata venom had no coagulant activity, and Bothriechis schlegelii venom had no haemorrhagic activity.

Amino Acid Oxidoreductases↗
PubMed1995

Cisapride compared with ranitidine in the treatment of functional dyspepsia.

OBJECTIVE: To compare the efficacy of the prokinetic drug cisapride and the antisecretory agent ranitidine in relieving symptoms of functional dyspepsia, as well as their effect on the recurrence of symptoms after the discontinuation of treatment. DESIGN: A randomized double-blind parallel-group trial of cisapride 30 mg daily and ranitidine 300 mg daily given for 2, 4 or 8 weeks, followed by a 4-week drug-free follow-up of the patients with a good or excellent response. Rescue antacid tablets were allowed only if pain was unbearable. PATIENTS: A total of 203 patients (99 cisapride, 104 ranitidine) with symptoms of functional dyspepsia for more than 4 weeks, after the exclusion of organic disease by endoscopy and sonography or radiology. RESULTS: Cisapride and ranitidine improved the symptoms of diffuse epigastric pain, postprandial epigastric fullness, epigastric distension, belching, heartburn, regurgitation, and nausea when compared with baseline. Pain at night and gastric discomfort also greatly improved. Cisapride produced a greater reduction in epigastric pain (P = 0.07) and epigastric distension (P = 0.03) scores than ranitidine. Both drugs were equally effective in reducing the concomitant reflux-like symptoms of heartburn and regurgitation. At week 8, 87% of cisapride patients versus 61% of ranitidine patients had an excellent or good result. The deterioration of symptoms during the follow-up phase was limited in both groups. However, after the withdrawal of medication there was a greater reduction in scores in the cisapride group than in the ranitidine group for diffuse epigastric pain (P = 0.05), epigastric distension (P = 0.002), the cluster of six symptoms of epigastric discomfort (P = 0.05), and the cluster of all nine upper gastrointestinal symptoms (P = 0.06). Adverse events occurred in 15 cisapride patients and 18 ranitidine patients, and two of the ranitidine patients were withdrawn from treatment. CONCLUSIONS: Although cisapride and ranitidine both improved the symptoms of functional dyspepsia, cisapride was superior to ranitidine, particularly on the combined evaluation of the response to treatment and the recurrence of symptoms.

Adult↗
PubMed1994

Esophageal motility disorders in patients with Sjögren's syndrome.

Esophageal motility was studied in 21 patients with Sjögren's syndrome, and in 25 normal volunteers, in order to record the prevalence and type of esophageal motor abnormalities. Esophageal motor abnormalities were detected in seven of the 21 patients (33.3%). These esophageal abnormalities did not correlate with the presence of dysphagia, the extraglandular involvement, or the presence of autoantibodies.

Deglutition Disorders↗
PubMed1977

Beckwitt-Wiedemann's syndrome with medullary sponge kidneys, agonadism and persistent testosterone production.

A patient with Beckwitt-Wiedemann's syndrome is described in which associated malformations were hemihypertrophy of the body, medullary sponge kidneys and absence of testes and internal ducts. On the other hand, we demonstrated biochemically the existence of testosterone secretion, with active response to a 3-day HCG stimulation as well as prepuberty levels LH and FSH. This demonstrated the existence of functioning Leydig's cells. The diagnosis of agonadism and anorchia could not be entirely true since they lead to an erroneous conclusion that there always are some disseminated Leydig's cells.

Abnormalities, Multiple↗
PubMedDate not supplied

[Alcoholism in an industrial population: diagnosis, prevalence and conditioning factors].

The pattern of alcohol consumption has been studied among 92 males, workers in a factory of the Lisbon area. In this population there were three groups of ethanol consumers: I--non consumers, 6%; II--medium, up to 80g/day, 68%; III--heavy consumers, more than 80g/day, 26%. Another group (IV) was considered, for reference, with 23 patients with heavy alcoholism in the outpatients of an alcoholic addicts clinic. Besides the clinical questionnaire and medical examination, the following methods have been used and analysed: brief MAST; Le Gô, Mean Corpuscular Volume (MCV), serum glutamic oxalacetic Trasaminase (SGOT), and gama-glutamyl transpepticlase (gamma GT). The mean ethanol consumption in group IV was significantly higher than in group III (p less than 0.005), and in group III higher than in group II (p less than 0.001). Group IV demarked itself form group III due to a higher prevalence of symptoms of physical dependence (p less than 0.001), and of consumption of tranquilizers (p less than 0.01). In group III the sensitivity of brief MAST has been only 8.5% and of Le Gô 13%. An increased MCV was found in 20% of individuals in group I, 4.9% in group II, 20% in group IV. The SGOT was normal in groups I and II, and increased in 8.7% of group III and 30.4% of group IV (p less than 0.05). The gamma GT was normal in group I and abnormal in 4.7% of group IV (p less than 0.01). In conclusion, approximately 25% of the workers have an excessive ethanol consumption.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMedDate not supplied

[Functional disorders of Oddi's sphincter].

The sphincter of Oddi (SO), located at a crucial anatomical site, continues to present diagnostic and therapeutic problems. A combination of the techniques of endoscopic retrograde cholangiopancreatography and manometry has permitted direct assessment of the SO function, and has opened up a new era in the study of this structure.

Ampulla of Vater↗