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Biomedical subjects

C Sampaio

Publications and source records attributed to C Sampaio.

At least 19 recordsLinked to original sources
PubMed1997

Movement Disorders Cochrane Collaborative Review Group.

Evidence-based medicine is the process of systematically finding, appraising, and applying contemporaneous research findings as the basis for clinical decisions. The individual clinician is too busy to perform this long and arduous task across the whole of their specialty, so they must rely on the highest quality reviews available in the literature. The Cochrane Collaboration is an international network of individuals preparing, maintaining, and disseminating systematic reviews of trials of all health care interventions. We examine the work of the Collaboration and the major method it uses to disseminate systematic reviews through the Cochrane Library. The rationale for the Cochrane Movement Disorders Group is discussed, and its management structure outlined.

Databases, Factual↗
PubMed1997

DYSBOT: a single-blind, randomized parallel study to determine whether any differences can be detected in the efficacy and tolerability of two formulations of botulinum toxin type A--Dysport and Botox--assuming a ratio of 4:1.

BACKGROUND: Elston and Russell discovered a difference in the biological potency of the English formulation of botulinum toxin type A or BTX-A (Dysport) and the American formulation (Botox). Potency of both is expressed in LD50 mouse units, but because of assay differences, these units are not equivalent. Since the first warning by Quinn and Hallet on the clinical importance of this issue, it has been impossible to reach a consensus on the conversion factor for the potency of these formulations. OBJECTIVE: To test the hypothesis that the conversion factor for the clinical potency of Dysport to Botox is approximately 4:1. DYSBOT is an acronym that results from adding "DYS" from Dysport with "BOT" from Botox. PATIENTS AND METHODS DESIGN: A single-blind, randomized, parallel comparison. A total of 91 patients with blepharospasm or hemifacial spasm were randomized to treatment with Dysport or Botox using a fixed potency ratio of 4:1. Clinical evaluations: The patients were evaluated at baseline (day of the treatment). 1 month after treatment, and whenever the effect was judged to be fading. Objective and functional rating scales were used as quantitative measures of the change in clinical status. Adverse reactions were collected using a systematic questionnaire. RESULTS: Using this ratio between products, both Dysport and Botox groups produced similar clinical efficacy and tolerability. For patients showing a positive response without the need of a booster, the duration of effect was 13.3 +/- 5.9 weeks for the Dysport group and 11.2 +/- 5.8 weeks for the Botox group. Of 48 patients, 11 (23%) needed booster treatment in the Dysport group compared with five (12%) of 43 in Botox group. Adverse events were noted in 24 (50%) of 48 patients in the Dysport group and 20 (47%) of 43 of the Botox-treated group. CONCLUSIONS: Using a 4:1 conversion ratio for Dysport and Botox, similar results were obtained for the two treatments in an appropriately powered study, suggesting that this conversion factor is a good estimate of their comparative clinical potencies.

Aged↗
PubMed1997

Botulinum toxin type A for the treatment of arm and hand spasticity in stroke patients.

BACKGROUND: Focal spasticity can be a major drawback in the rehabilitation of stroke patients. Previous studies suggest a beneficial effect for botulinum toxin A (BTX-A) for relief of spasticity. OBJECTIVE: To evaluate the safety and efficacy of BTX-A in the treatment of spasticity in a homogeneous group of stroke patients. METHODS: In this phase III open label trial 19 stroke patients stable for at least six months were enrolled (mean age 53.1 (SD 3.27) years; range 26-72). There were 16 males and 4 females. ASSESSMENTS: Clinical (Ashworth spasticity rating scale, scores for joint mobility, pain and frequency of spasms, Frenchay arm test (FAT)) and subjective (semi-quantitative rating scale filled out by the patient). Only hand and finger flexors were injected. The maximum dosage was 150 U BOTOX (25 U/muscle), the mean dosage was 92.1 +/- 31.6 U BOTOX. RESULTS: Ashworth rating scale and joint mobility scores improved from a median value of 2 at baseline to a median value of 1 one month after treatment, FAT scores also improved from a median value of 0 at baseline to a median value of 1 one month after treatment (Kruskall-Wallis test p < 0.01). Two-thirds of the patients rated their functional improvement as none or mild. CONCLUSIONS: Our study confirmed that BTX-A has an anti-spastic effect but its functional impact needs further evaluation.

Adult↗
PubMed1995

A behavioral evaluation of PCE exposure in patients and dry cleaners: a possible relationship between clinical and preclinical effects.

Long-term deficits in visuospatial function and memory and disturbances in mood have been clinically identified and followed in four patients occupationally exposed to perchloroethylene (PCE). A frontal/limbic hypothesis is offered as the site of pathology. A separate study among 65 dry cleaners was conducted to provide similar evidence of impairment, suggesting a continuum between clinical and preclinical effects. Three exposure zones were identified for the counter clerks, pressers, and operators corresponding to air levels of 11.2, 23.2, and 40.8 ppm. Decrements were found for visual reproductions (14.4%), the number correct (6.7%) and the latency (10%) for pattern memory, and the number correct (3.9%) for pattern recognition. Chronic, life-long deficits appear below 50 ppm and require at least 3 years of exposure. A reexamination of the OSHA standard is recommended and shows that behavioral testing can be used as an early indicator of more serious clinical effects.

Adult↗
PubMed1995

The response of "de novo" Parkinson's disease patients to bromocriptine in a "low and slow" regimen is predictive for prognosis.

It is possible that Bromocriptine only determines a complete antiparkinson effect in a subset of P.D. patients that have a good dopaminergic reserve. Our study intent to demonstrate that a good short-term response to Bromocriptine used in a "low and slow" regimen is a marker of long term good prognosis. We studied a series of 36 sequential "de novo" P.D. patients treated with Bromocriptine in a "low and slow" regimen. The principal end-point was the introduction of Levodopa. "Good prognosis" was defined as no need of Levodopa until five years of follow-up. An improvement greater than 33% in the Columbia rating scale, at the 6th month of treatment, was the cut-off point to decide that a patient had a good short term response to Bromocriptine. Nine patients fulfilled the criteria for being good short term responders. Multiple regression analysis showed that this outcome could not be predicted by the clinical characteristics of the patients at admission. The sensitivity and the specificity of the short term response to Bromocriptine to predict a good prognosis were 70% and 90.5% respectively. We conclude that Bromocriptine in monotherapy is an efficient antiparkinson agent in 1/3 of "de novo" P.D. patients and good short term response to Bromocriptine is an acceptable marker for a good prognosis. Therefore it is possible that the response to Bromocriptine is a discriminator for a subset of P.D. patients in the early phases of the disease.

Adult↗
PubMed1991

Acute behavioural comparisons of toluene and ethanol in human subjects.

A comparison of toluene and ethanol (EtOH) induced changes in central nervous system (CNS) function and symptoms were evaluated in two studies, and when possible the effects of toluene were expressed in EtOH equivalent units. The toluene concentrations were 0, 75, and 150 ppm, bracketing the American Conference of Governmental Industrial Hygienists threshold limit value (ACGIH TLV) of 100 ppm. The socially relevant EtOH doses were 0.00, 0.33, and 0.66 g EtOH/kg body weight, equivalent to two and four 3.5% 12 ounce beers. Forty two paid college students were used in each study. In the first study, subjects were exposed to toluene and an odour masking agent menthol (0.078 ppm) for seven hours over three days. In the second study EtOH or a placebo was administered at 1530 across three days also in the presence of menthol. Verbal and visual short term memory (Sternberg, digit span, Benton, pattern memory), perception (pattern recognition), psychomotor skill (simple reaction time, continuous performance, symbol-digit, hand-eye coordination, finger tapping, and critical tracking), manual dexterity (one hole), mood (profile on mood scales (POMS), fatigue (fatigue checklist), and verbal ability were evaluated at 0800, 1200, and 1600. Voluntary symptoms and observations of sleep were collected daily. A 3 x 3 latin square design evaluated solvent effects simultaneously controlling for learning and dose sequence. An analysis of variance and test for trend were performed on am-pm differences reflecting an eight hour workday and on pm scores for each solvent, in which subjects were their own control Intersubject variation in absorbance was monitored in breath. A 5 to 10% decrement was considered meaningful if consistent with a linear trend at p less than 0.05. At 150 ppm toluene, losses in performance were 6.0% for digit span, 12.1% for pattern recognition (latency), 5% for pattern memory (number correct), 6.5% for one hole, and 3% for critical tracking. The number of headaches and eye irritation also increased in a dose-response manner. The greatest effect was found for an increasing number of observations of sleep. A range of 2 to 7% decrements suggest the ACGIH TLV of 100 ppm toluene may be a good estimate of the biological threshold supporting a re-evaluation of the TLV. At 0.66 g EtOH/kg body weight symptoms and performance decrements were 6.6% for digit span, 9.2% for pattern recognition, 4.0% for continuous performance, 7.9% for symbol-digit, 16.5% for finger tapping, 6.2% for critical tracking, and 5.2% for the one hole test. The EtOH equivalents at 150 ppm toluene for digit span (0.56g EtOH/kg/body weight), the latency for pattern recognition (0.66 g EtOH kg body weight), and the one hole element "move" (0.37 g EtOH kg body weight) show that the first two measures would be affected at or above the 50 mg% blood alcohol concentration. This concentration is recognised as the lowest alcohol concentration associated with increased numbers of automobile accidents. The results suggest that EtOH may be a useful acute standard to compare the effects of various industrial solvents and support investigating an association between exposure to solvents and increased risk to safety in industry.

Adolescent↗
PubMed1990

Perchloroethylene exposure assessment among dry cleaning workers.

Perchloroethylene (Perc), the most widely used solvent in dry cleaning, is toxic to the liver, kidneys, and central nervous system and may be a human carcinogen. In the Detroit area, as part of a project investigating the health status of dry cleaning workers, an exposure assessment was carried out in dry cleaning plants using perchloroethylene. Breath samples were obtained from each participant, and time-weighted average (TWA) breathing zone air samples were obtained using passive dosimeters on a subset expected to experience a range of exposures. Perc in breath and Perc in air were highly correlated (r2 = 0.75, p less than 0.0001). On average, operators of dry cleaning equipment experienced significantly more exposure than nonoperators. Also, employees working in shops that use transfer equipment (requiring physical transfer of Perc-saturated clothing from washers to dryers) showed significantly higher exposure than those in shops utilizing dry-to-dry machinery (permitting washing and drying in one machine in a single cycle). One or more air samples in every transfer shop exceeded the recently revised Occupational Safety and Health Administration (OSHA) permissible exposure limit (PEL) of 25 ppm, while no air samples in dry-to-dry shops exceeded this limit. The results suggest concern for exposures to operators in transfer shops and that compliance with the PEL is achievable by engineering controls with presently existing technology.

Adult↗
PubMed1989

Acute neurobehavioural effects of toluene.

An acute inhalation chamber study of 42 college students was performed to investigate the relation between exposure to 0, 75, and 150 ppm of toluene and changes in central nervous system function and symptoms. Paid subjects were exposed for seven hours over three days. Verbal and visual short term memory (Sternberg, digit span, Benton, pattern memory); perception (pattern recognition); psychomotor skill (simple reaction time, continuous performance, digit symbol, hand-eye coordination, finger tapping, and critical tracking); manual dexterity (one hole); mood (profile of mood scales (POMS]; fatigue (fatigue checklist); and verbal ability were evaluated at 0800, 1200, and 1600 hours. Voluntary symptoms and observations of sleep were collected daily. An analysis of variance and test for trend was performed on the difference and score for each concentration reflecting an eight hour workday where each subject was their own control. A 3 x 3 Latin square study design evaluated toluene effects simultaneously, controlling for learning across the three days and the solvent order. Intersubject variation in solvent uptake was monitored in breath and urine. A 5-10% decrement in performance was considered significant if it was consistent with a linear trend at p less than 0.05. Adverse performance at 150 ppm toluene was found at 6.0% for digit span, 12.1% for pattern recognition (latency), 5.0% for pattern memory (number correct), 6.5% for one hole, and 3.0% for critical tracking. The number of headaches and eye irritation also increased in a dose response manner. The greatest effect was found for an increasing number of observations of sleep. Overall, no clear pattern of neurobehavioural effects was found consistent with the type 1 central nervous system as classified by the World Health Organisation. Subtle acute effects, however, were found just below and above the ACGIH TLV of 100 ppm toluene, supporting the position that the guideline be lowered since the biological threshold of behavioural effects may be comparable with the TLV.

Adolescent↗
PubMed1986

The liver is the main organ to clear plasma and tissue kallikreins from rat plasma, in vivo.

We report observations regarding the in vivo distribution of labelled kallikreins in plasma, liver and some other organs, twenty minutes following their intravenous injection in the rat. The kallikreins used were: tritiated homogeneous human plasma (HuPK) and horse urinary (HoUK) as well as highly purified iodinated rat plasma kallikrein (RPK). The main findings were: the liver cleared 15% of HuPK, 38% of RPK and 69% HoUK; with both types (plasma and tissue) of native kallikreins the liver was the main clearing organ.

Animals↗