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Biomedical subjects

F Feron

Publications and source records attributed to F Feron.

11 recordsLinked to original sources
PubMed2006

[Chronic instability in the ankle area].

For ankle sprains, the initial radiological work-up must include weight-bearing AP and lateral stress views of the sprained and healthy ankle. Films are taken in auto-varus. Other explorations included arthroMRI, arthroscanner or MRI which can be indicated preoperatively to confirm suspected cartilage injury or an associated ligament tear. These techniques should be employed when pertinent information can be expected according to the clinical situation and the operator's experience. In the emergency setting, ultrasonography can provide a simple low-cost confirmation of joint hematoma which is more precise than x-rays with a positive predictive value of nearly 100%. The objective and subjective clinical outcome after surgical anatomic repair or ligamentoplasty are quite similar. The two principal differences relate to persistent subjective instability and post-operative surgical complications. Thus there are advantages and disadvantages for each option advantage for anatomical repair because of the low rate of surgical complications and advantage for ligament repairs which stabilize the subtalar joint with a low rate of residual instability.

Ankle↗
PubMed2005

[Peripheral nerve repair: 30 centuries of scientific research].

INTRODUCTION: Nerve injury compromises sensory and motor functions. Techniques of peripheral nerve repair are based on our knowledge regarding regeneration. Microsurgical techniques introduced in the late 1950s and widely developed for the past 20 years have improved repairs. However, functional recovery following a peripheral mixed nerve injury is still incomplete. STATE OF ART: Good motor and sensory function after nerve injury depends on the reinnervation of the motor end plates and sensory receptors. Nerve regeneration does not begin if the cell body has not survived the initial injury or if it is unable to initiate regeneration. The regenerated axons must reach and reinnervate the appropriate target end-organs in a timely fashion. Recovery of motor function requires a critical number of motor axons reinnervating the muscle fibers. Sensory recovery is possible if the delay in reinnervation is short. Many additional factors influence the success of nerve repair or reconstruction. The timing of the repair, the level of injury, the extent of the zone of injury, the technical skill of the surgeon, and the method of repair and reconstruction contribute to the functional outcome after nerve injury. CONCLUSION: This review presents the recent advances in understanding of neural regeneration and their application to the management of primary repairs and nerve gaps.

Axons↗
PubMed2005

The combination of shared family environment and individual-specific developmental deviance as a cause for treated psychiatric morbidity in children.

OBJECTIVE: There is an incomplete understanding of why some children growing up in the same family are in need of treatment for psychiatric morbidity whilst their siblings are not. The present paper examined the possible role of individual-specific developmental risk factors. METHOD: Three case-control analyses were conducted: i) 80 children referred to the Community Mental Health Centre (cases) and 320 population controls, ii) 68 healthy siblings of cases and 272 population controls, and iii) 80 children and 68 healthy siblings. Measures of development and psychosocial circumstances were obtained from routine, longitudinal, standardized child medical records. RESULTS: Given shared family environments, additional presence of delays in speech and motor development contributed most to differential sibling mental health outcomes. In addition, cases displayed both earlier expression and more severe levels of developmental behavioural deviance than their healthy siblings, who in turn had higher levels of behavioural deviance than population controls. CONCLUSION: In siblings sharing a familial risk environment, development of psychiatric morbidity may be canalized through additional individual-specific developmental exposures.

Adolescent↗
PubMed2003

Vitamin D3 and brain development.

Evidence for the presence of the vitamin D receptor in brain implies this vitamin may have some function in this organ. This study investigates whether vitamin D(3) acts during brain development. We demonstrate that rats born to vitamin D(3)-deficient mothers had profound alterations in the brain at birth. The cortex was longer but not wider, the lateral ventricles were enlarged, the cortex was proportionally thinner and there was more cell proliferation throughout the brain. There were reductions in brain content of nerve growth factor and glial cell line-derived neurotrophic factor and reduced expression of p75(NTR), the low-affinity neurotrophin receptor. Our findings would suggest that low maternal vitamin D(3) has important ramifications for the developing brain.

Animals↗
PubMed1994

Anaphylatoxin C5a production during short-term submaximal dynamic exercise in man.

We studied the effects of short-term submaximal exercise on the plasma levels of myeloperoxidase ([MPO]) and C5a anaphylatoxin ([C5a]), taken as specific markers of polymorphonuclear neutrophil (PMN) and complement activation, respectively. Eleven young, healthy male volunteers were subjected to a constant-load concentric exercise on a cycle ergometer (20 min at 80% maximal oxygen uptake). Mean resting MPO and C5a concentrations were 437 +/- 113 and 0.47 +/- 0.21 ng/ml, respectively. During exercise, [MPO] and [C5a] increased significantly (p < 0.001) towards respective peak values of 649 +/- 131 and 1.3 +/- 0.6 ng/ml. A rapid decrease of both [MPO] and [C5a] was observed during recovery. The similar time course of [MPO] and [C5a] changes and the highly significant relationship between these two variables (r = 0.651; p < 0.001) argues for the possible involvement of the complement anaphylatoxin C5a in the process of PMN degranulation. During exercise, the number of circulating PMN increased (+80%; p < 0.001) and remained practically unchanged up to 20 minutes of recovery. As [MPO] and PMN count were not significantly related (r = 0.2; p < 0.1), we concluded that the activation of PMN was independent of their mobilization.

Adult↗
PubMed1994

Decreased expression of the two D2 dopamine receptor isoforms in bromocriptine-resistant prolactinomas.

Bromocriptine or other dopamine agonists are usually effective for the treatment of prolactin-secreting adenomas. Five to 18% of prolactinomas, however, do not respond to such therapy. We have shown previously that such resistance to bromocriptine correlates with reduced binding to the D2 receptor subtype of dopamine, the major PRL inhibiting factor. In the present work, we demonstrated that reduced binding actually corresponds to decreased expression of the gene coding for the D2 receptor in the pituitary from bromocriptine-resistant patients, as shown by 4-fold lower levels of the corresponding mRNAs compared to those coding for actin. The existence of two D2 receptor isoforms, D2S and D2L generated by alternative splicing, has been described in several tissues, including the pituitary. Both are negatively coupled to adenylyl cyclase and inhibit prolactin secretion, but, in addition, the shortest one (D2S) is more efficiently coupled to phospholipase C. Consequently, we also investigated whether expression of a particular D2 receptor isoform was preferentially affected in resistant adenomas. The proportion of messengers corresponding to the short receptor isoform (D2S) was lower in resistant compared to responsive adenomas: D2S/D2L = 0.74 +/- 0.08 and 1.00 +/- 0.07, respectively. In parallel, much lower levels of D2 receptor mRNAs were found in growth hormone-secreting adenomas, with a D2S/D2L ratio comparable to those of both normal human pituitary and bromocriptine-sensitive prolactinomas (1.05 +/- 0.11). Thus, resistance to bromocriptine therapy seems to involve defects in D2 dopamine receptor expression and possibly in posttranscriptional splicing.

Adenoma↗
PubMed1991

[Mobilization of leukocytes during sub-maximal dynamic exercise].

Increase of blood leucocytes induced by a dynamic exercise has been studied in 10 adult male subjects (age: 22 +/- 2 years; body weight 73 +/- 10 kg; VO2max: 54 +/- 8 ml O2/kg.min. The exercise consisted of a 20 minutes test on a cycle ergometer at a work rate eliciting a total energy expenditure roughly equal to 80% of the maximal aerobic power (80% VO2max). During exercise the absolute number of circulating leucocytes (n Leu) increased significantly toward a maximal value reached in most cases at the end of exercise. The maximal values of n Leu--expressed as percentage of n Leu measured at rest--in the different blood leucocyte types (monocytes:n Mono; granulocytes:n GR; natural killer cells:n NK) and lymphocyte subsets (lymphocytes:n LY; lymphocytes T:n T; lymphocytes B:n B; lymphocytes T helper:n T4; lymphocytes T suppressor:n T8)--were as follows:n Mono:240%; n GR:170%; n NK:490%; n LY:220%; n T:200%; n B:190%; n T4:140%; n T8:190%. With the exception of n GR, n Leu decreased during recovery at a rate depending on the leucocyte type. The n T4/n T8 ratio, equal to 1 at rest, was reduced by about 40% during exercise. This ratio rose after exercise and reached a value equal to that measured at rest after 20 minutes recovery. In agreement with FERRY (1989), we concluded that exercise is accompanied by a selective mobilization of the different leucocyte types. The magnitude of this phenomenon and the kinetics of n Leu recuperation depend on cell types.

Adult↗