Biomedical subjects

P Gorce

Publications and source records attributed to P Gorce.

12 recordsLinked to original sources

PubMed2006

Kinematic analysis of handbike propulsion in various gear ratios: implications for joint pain.

BACKGROUND: Though considered more efficient and less constraining than the hand-rim wheelchair, the handbike has rarely been studied especially as regards its kinematic parameters. The hypothesis of this investigation is that the range of upper extremity motions are risk factors for joint pain during handbiking as is the case during hand-rim wheelchair propulsion. This paper aims to study handbike propulsion in maximal sprint conditions in order to determine potential risk factors for joint pain. METHODS: Eight able-bodied participants with no experience in handbike propulsion performed three sprints of 8 s each using three gear ratios in a handbike mounted on a home-trainer. The mean velocity per arm cycle, the cycle frequency, the angular parameters for the upper extremities were calculated, as well as the corresponding angular accelerations, with the help of a 3D movement analysis. FINDINGS: An increase in gear ratio (22/21, 32/21, and 44/21) significantly increases the maximal velocity, the flexion/extension of the trunk, as well as the adduction/abduction of the elbow, while it reduces the frequency of movements and the flexion/extension angular accelerations of the shoulder and the elbow. Regardless of what gear ratio is used, maximal angular amplitudes of the upper extremities are comparable to the values obtained with a hand-rim wheelchair. Interpretation. The high amplitudes and fast angular joint accelerations of the upper extremity found in this study are near or superior to the ergonomic recommendations generally advised. These considerations could be taken into account to prevent overuse injuries.

Acceleration↗

PubMed2006

Substrate optimization in nut cracking by capuchin monkeys (Cebus apella).

We conducted an experiment to examine the effect of substrate on the nut-cracking behavior of a group of semicaptive capuchin monkeys. We wanted to determine whether tufted capuchin monkeys were selective in choosing the substrate on which they pound nuts, and whether the choice of substrate affected the outcome. Eight adult females and eight juveniles were provided with nuts in the outdoor facility. We found that 1) all adult females and three young capuchins succeeded in cracking nuts; 2) they preferred the hardest substrates (concrete and stone); 3) there is a link between the substrate and the amount of time needed to crack a nut; 4) most young capuchins used various substrates, some of which were inadequate, in a haphazard manner; and 5) there are different forms of nut cracking. We conclude that adult capuchins choose the hardest substrates, and that these substrates support efficient cracking.

Animals↗

PubMed2006

Reproducibility of performance in three types of training test in swimming.

A variety of testing procedures are used to assess the effects of particular treatments on the training status of athletes. The present study aims to investigate the reproducibility of selected tests in swimming. Sixteen trained swimmers performed three kinds of test: 1) Constant Distance Test (CDT), 2) Constant Time Test (CTT), and 3) Constant Velocity Test (CVT). The analysis of the reproducibility was based on a test-retest procedure. The test-retest performances were highly correlated for the three kinds of test (r = 0.98, 0.98, and 0.93 for CDT, CTT and CVT, respectively). The mean Coefficient of Variation (CV) was computed between test-retest for each subject and each procedure. A repeated measures one-way ANOVA showed that CVT was significantly less reliable (CV = 6.46 +/- 6.24 %) than CDT and CTT (CV = 0.56 +/- 0.6 0 % and 0.63 +/- 0.54 % respectively) (p < 0.001). Psychological factors and a lack of familiarity with CVT (not extensively used during training session) could explain its greater variability. Thus, CDT and CTT seem to be the most reliable tests to detect the smallest meaningful change in the training status of swimmers. Post-hoc power calculations of the experimental design showed the sample size would have to increase to 80, 113, and 228 subjects for CWT, CDT and CPT respectively, to reach a power of 80 %. The minimal detectable differences have to be calculated to ensure a real effect of a particular treatment on a group of swimmers, according to the kind of test used.

Adult↗

PubMed2000

[Meningitis after locoregional spinal anesthesia].

OBJECTIVE: Meningitis is a severe and an uncommon complication of both spinal and epidural anaesthesia. This review summarizes the knowledge on epidemiology, clinical and microbiological diagnosis and the ways to prevent them. DATA SOURCES: Articles published in English and French language since 1989 has been collected on Medline database, using "meningitis", "spinal anaesthesia" and "epidural anaesthesia" as keywords. DATA SYNTHESIS: Bacterial meningitis are usually in relation with Gram positive bacterias which is a clue for an exogenous contamination. Another unusual ways of contamination are blood circulating bacterias and spreading of local infection. Aseptic meningitis has been described, in relation to introduction of irritant agents in subarachnoid space. Lumbar puncture must be done each time meningitis suspected so that it can assert the diagnosis and guide antibiotherapy. Easy hygienic guidelines has been widely published to prevent meningitis. Usually, antibiotherapy alone is sufficient to treat meningitis but with an unjustified cost and sometimes severe persistent neurologic sequelae. CONCLUSION: The unexpected appearance of meningitis during the wearing-off of a spinal anesthesia is exceptional; the possibility of death or serious sequela must be taken into account. The sources of contamination are quite frequently exogenous, the germs coming most often from the patient's cutaneous flora or the anesthetist's ENT flora. Prevention of this risk involves a rigorous respect for cutaneous disinfection and hygiene procedures. The anesthetist's medico-legal responsibilities will be called upon in case of exogenous contamination.

Adolescent↗

PubMed2000

Effects of isoflurane on bacterial growth.

Anaesthetic agents have been implicated in the development of postoperative pneumonia, but the direct effect of volatile anaesthetics on bacterial growth has given contradictory results. The effects of isoflurane on the growth of Staphylococcus aureus and Escherichia coli were investigated under conditions similar to those of clinical practice, using standardized microbiological methods. An open anaesthetic circuit was adjusted to the normal ventilatory settings of an adult patient. A spray, installed on the inspiratory side of the circuit, ensured the delivery of isoflurane at 1.5 minimal alveolar concentration. The bacterial strains studied were both wild-type and reference strains. Bacterial inoculums were prepared to obtain a bacterial exponential growth of 10(3) colony-forming units per mL in 10 mL of nutritive broth. Each strain was studied with and without exposure to isoflurane and measured by the usual criteria of bacterial growth, and by bacterial regrowth after exposure to isoflurane. Under experimental conditions close to clinical practice, exposure to isoflurane did not alter bacterial growth of S. aureus and E. coli, or their bacterial regrowth when isoflurane exposure is over.

Anesthesia, Inhalation↗

PubMed2000

[Meningitis after spinal anesthesia].

The occurrence of meningitis after spinal anaesthesia is a very rare event. We report a case of Streptococcus sanguis meningitis following spinal anaesthesia for orthopaedic material removal. The presence of Gram positive cocci (Streptococcus sanguis) in the cerebrospinal fluid was in favour of an exogenous contamination, originating either from the patient's skin or the anaesthesiologist's oropharynx. The outcome was uneventful. The responsibility of the latter can result in legal consequences. The scrupulous compliance with guidelines prevents this risk.

Adult↗

PubMed1999

[Drug expenses from anesthesiologists].

OBJECTIVES: To assess expenses generated by prescriptions from anaesthesiologists in the operating theatre, recovery rooms, surgical intensive therapy units, postoperative care on surgical wards (digestive surgery, orthopaedics, gynaecology, obstetrics, paediatric surgery). METHODS: Prospective study (one year) with evaluation of the costs induced by intravenous and volatile anaesthetics, morphinic and non morphinic analgesics, neuromuscular blocking agents, crystalloids, antibiotics, intravenous nutrient solutions, blood substitutes, anticoagulants, vitamins and vasoactive drugs. RESULTS: The expenses resulting from these prescriptions reached the quarter of the total drug hospital budget. They were equally distributed between anaesthesia and intensive therapy units on the one hand and postoperative care on surgical wards on the other hand. Intravenous anaesthetic agents, antibiotics, crystalloids, represented each one more than 10% of the total cost. CONCLUSIONS: This study demonstrates the weight of prescriptions by anaesthesiologists in the hospital budget. At our hospital, it was mainly due to their activity outside the operating theatre, especially on surgical wards. Therefore anaesthesiologists are essential partners for the elaboration of a cost containment policy.

Anesthesiology↗

PubMed1994

[Distribution of a hypoxic gas mixture by retro-pollution of a medical gas distribution system].

The authors report a case of retropollution through the defective gas mixer of a Logic O4T-IMV ventilator (Ohmeda) located in the recovery room. Due to a defective check valve inside the mixer, medical air entered into the oxygen pipeline when the O2 pressure decreased below the pressure inside the medical air pipeline. This incident resulted in episodes of hypoxic gas mixture delivery in the operating theatre, when nitrous oxide was associated with oxygen polluted with medical air. The occurrence of such an incident, rarely described so far, requires the association of several factors. It can be recognized without delay with the continuous use of an oxygen analyser.

Air↗

PubMed1993

[Transcranial Doppler: methodology and indications in 1993].

Transcranial Doppler ultrasound is a new non-invasive method of exploration which through the use of low frequencies and transcranial windows is able to investigate the main vessels in the Willis polygon. It now has a variety of applications: diagnosis of stenoses and intracranial occlusions, assessment of the intracerebral impact of stenoses and occlusions of the internal carotid artery, monitoring of the middle cerebral artery in situations involving intensive care or carotid surgery, diagnosis of cerebral arteriovenous malformations, the diagnosis of brain death and the follow-up of secondary spasm due to meningeal hemorrhage. The combination of continuous Doppler and ultrasound scan with a transcranial Doppler scan is able to modify the indications for an arterial angiography, notably in cerebral ischemic disease. Its non-invasive nature and convenience will favor its future development for diagnostic purposes and, above all, for short-term monitoring or periodic long-term check-ups.

Adult↗

PubMed1989

Intrathecal porcine calcitonin enhances the release of [Met5]enkephalin-like material from the rat spinal cord.

Perfusion of the intrathecal space of halothane-anaesthetized rats with artificial cerebro-spinal fluid supplemented with porcine calcitonin (1-10 microM) produced a significant increase (+67-110%) in the spinal release of [Met5]enkephalin-like material. The effect of porcine calcitonin was markedly enhanced (+100%) in animals receiving a continuous i.v. infusion of the opioid antagonist naloxone (65 micrograms/kg per min). These data strongly suggest that the antinociceptive effect of intrathecal porcine calcitonin might involve a stimulatory action of the hormone on spinal enkephalinergic interneurones. In addition, presynaptic opioid autoreceptors probably control the activity of these neurones in the rat.

Animals↗

PubMed1987

Motor neuron disease, parkinsonism and dementia. Report of a case with diffuse Lewy body-like intracytoplasmic inclusions.

The clinicopathological findings in a 49-year-old man who presented multisystemic neurological degenerative disease are reported. The patient presented, at the age of 36, distal upper limb amyotrophy and 8 years later pyramidal signs with fasciculations. In his last year of life, he suffered extrapyramidal hypertonus and mental deterioration. Neuropathological examination showed anterior spinal root and cerebral atrophy. Myelin pallor was mild and predominated on posterior cords. Anterior horn neuronal loss was noted in the spinal cord as well as Alzheimer-type changes in the brain. Inclusion bodies consistent with Lewy bodies were diffusely apparent. The peculiar clinical progression in this case and the extension of neuropathological lesions with inclusion bodies mainly in the substantia nigra and cerebral cortex are an interesting subject of discussion.

Brain↗

PubMed1984

Inhibition of polyriboinosinic:polyribocytidylic acid-induced depression of mouse hepatic mixed function oxidases by actinomycin D or cycloheximide.

Administration of a single dose of the potent interferon inducer poly rI:rC to Swiss Webster mice depressed hepatic cytochrome P-450 to 75% of control, ethylmorphine N-demethylase to 56% of control and DMN N- demethylases I and II to about 80% of control. Although each enzyme responded in a unique manner, maximum depression occurred at 24 hours after poly rI:rC administration and the concurrent administration of inhibitors of protein synthesis (actinomycin D or cycloheximide) prevented this depression. These data suggest that poly rI:rC effects on the mixed function oxidases are not species specific although depression follows a time course shorter than that reported in the rat (maximum depression at 40 hours after poly rI:rC administration) and that depression occurs through the stimulation of a protein responsible for degrading cytochrome P-450.

Animals↗