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Biomedical subjects

D Barbier

Publications and source records attributed to D Barbier.

At least 19 recordsLinked to original sources
PubMed2002

Screw fixation to the posterior cortical shell does not influence peak torque and pullout in anterior cervical plating.

There is no consensus over whether screw fixation for anterior cervical plating should include the posterior cortical shell of the vertebral bodies or not. Thus, the purpose of this study was to investigate the function of the posterior cortical shell with respect to maximal screw torque and pullout force. Twenty-four fresh frozen human cervical vertebrae coming from six spinal segments C4-C7 were used. They were scanned for bone mineral density (BMD) and then assigned to two groups with comparable bone density and segmental distribution. The posterior longitudinal ligament was resected carefully and two parallel burr holes were drilled into each vertebral body. The posterior cortical shell was removed in one burr hole, using a 6-mm steel burr, producing a shallow excavation with a depth of approximately 2 mm. An ABC screw was inserted into each burr hole. The screw to be inserted into the hole with the posterior excavation was called "monocortical". In contrast, the contralateral screw was called "bicortical". Peak torque was measured in one group, while pullout force was analyzed using the specimens of the second group. Mean value and standard deviation were calculated for peak torque and pullout force with respect to the type of fixation. A paired t-test was used to determine the effect of fixation type on peak torque and pullout force. Pearson moment correlation coefficients were calculated to determine the effect of BMD on peak torque and pullout force with respect to whether the screw was "mono- or bicortical". A 95% level of significance was used for all tests. No significant differences for peak torque and pullout force could be found comparing monocortical and bicortical screw fixation. However, for both monocortical and bicortical screw fixation, a positive correlation was seen for peak torque versus BMD and for pullout force versus bone mineral density, respectively. The importance of the posterior cortical shell for screw pullout force and screw peak torque seems to be negligible. In constrast, BMD greatly influences both peak torque and pullout force for both types of fixation.

Bone Density↗
PubMed2002

Down's syndrome screening with nuchal translucency at 12(+0)-14(+0) weeks and maternal serum markers at 14(+1)-17(+0) weeks: a prospective study.

BACKGROUND: Sonographic and biochemical methods for Down's syndrome screening have developed simultaneously, but independently. As a consequence, the rate of invasive procedures for fetal karyotyping has dramatically increased and become an important public health issue which needs to be controlled. One approach is to combine sonographic and biochemical results into a single risk assessment. METHODS: In a multicentre interventional study, nuchal translucency (NT) was measured between 12(+0) and 14(+0) weeks of gestation. Maternal serum markers (MSM) were measured between 14(+1) and 17(+0) weeks of gestation. Karyotyping was advised when: (i) NT was > or =3 mm; or (ii) the MSM-related risk was > or =1 in 250 at term. Karyotyping was delayed until after a maternal blood sample had been taken. NT and MSM were expressed as multiples of the medians (MoMs), and risks were calculated and tailored to the study population. A combined risk for NT and MSM was estimated retrospectively. Costs per case diagnosed, and the cost per case averted were calculated for the three screening strategies. RESULTS: A total of 9444 women was screened. Twenty-one fetuses (0.22%) had Down's syndrome, whilst 326 women (3.4%) were lost to follow-up. Among 9118 women followed up, 5506 had both NT and MSM, 821 had only NT, and 2791 had only MSM. Median maternal age was 30.5 years. False-positive rates for NT, MSM and NT combined with MSM were 3.0, 5.8 and 0.23% respectively. The false-positive rate generated by a sequential two-stage screening was 8.6%. Detection rates of Down's syndrome were 62 and 55% for NT and MSM respectively. Seven cases with Down's syndrome (35%) had raised NT and MSM, and 17 (81%) had either raised NT, MSM, or both. For a 5% false-positive rate, detection rates were 55 and 80% for NT alone and for combined NT and MSM respectively. Ultrasound alone appears to be more cost-effective ( pound50 per case diagnosed) than both tests ( pound61 per case diagnosed). CONCLUSIONS: The study results suggest a 25% increase in the detection rate of Down's syndrome using a combination of NT measurement at 12(+0)-14(+0) weeks and MSM at 14(+1)-17(+0) weeks for a 5% false-positive rate, with modest increase in cost.

Biomarkers↗
PubMed2001

[Suicide].

BRIEF HISTORY: The definition of suicide differs depending on the era, author or theory. Society's attitude has varied throughout history. When psychiatry appeared in the nineteenth century it medicalized the problem. First with Esquirol in 1838, followed by Delmas in 1932. Whereas Durkheim, with his theory of anomia in 1897, defended the sociological position presented in the form of a law: the percentage of suicides increases in inverse proportion to the social integration of the individual and one should not forget Halbwachs (1930) in this debate. Re-medicalization was mainly due to Deshaies in 1947, who dismissed the excessiveness of these two trends, while remaining open to them. According to his theory, "suicidal equivalences" should also be taken into account, even if the individual's death wish is subconscious. CONTRIBUTION OF THE PSYCHOANALYTICAL THEORY: This contribution is considerable and has gone through several stages. Currently, psychoanalysts accept the influence of extrinsic factors in suicidal behavior. This is the case, for example, for the pre-morbid states or the initiating factors, the importance of which are no longer denied and which favor regression and destruction of the personality and resulting in suicidal behavior. DOES A CLINICAL PROFILE EXIST?: Fifteen percent of depressive patients commit suicide. With regard to the act itself, it is far more dangerous and violent in the elderly than in young adults. The suicide rate of elderly people is 2-fold greater than that of the general population. Suicidal equivalents consist in letting oneself die, because of the loss in will to fight that characterizes the classical syndrome of this attitude. EPIDEMIOLOGICAL DATA: In France there are around 12,000 suicidal deaths per year among 150,000 suicide attempts, i.e., 1 attempt every 4 minutes and 1 suicide every 40 minutes. This corresponds to a raw mortality rate of 20 out of 100,000 inhabitants. However, epidemiologists consider that these figures are underestimated by around 20%. Since 1983, they exceed the mortality rate caused by road accidents (8,000/year in France). MISINTERPRETED DEPRESSION: Most suicides result from depression that was not recognized and treated as such. Clinical intuition is essential. It is the risk of suicide that renders the diagnosis of depression urgent. Retrospective surveys show that 50% of individuals having attempted suicide had consulted a doctor the month preceding their act. It is therefore important to organize the prevention of such risks. When depressive patients do not express any suicidal tendency, it is essential to raise the subject. In most cases, verbalization relieves the patients. However the eventual hospitalization of such patients should always be boum in mind.

Adult↗
PubMed2001

[Mourning].

A PAINFUL EXPERIENCE: Mourning characterizes the grief of a person who has lost a loved one forever. The bereavement that follows is natural and should not be medicated. Mourning is not a disease; it is one of the most painful facts of life. In fact, the more we are attached to someone, the more we will suffer his or her loss. This is unavoidable. The grief expressing our attachment is accompanied by immediate and intense regression with repeated need for consolation. For some people, it can be the means of coming to terms with their own mortality. THE STAGES OF MOURNING: There are several stages of mourning: the living person's ambivalence toward the deceased, the recollection corresponding to the progressive acceptance of the loss, which represents the first phase of the mourning process. During the healing phase, the mourner is gradually capable of recalling the good times during the life of the deceased and then progressively of evacuating the souvenirs and start living and opening up to others again. COMPLICATED MOURNING: Mourning may be passionate and characterized by the refusal to integrate the loss, or delayed, with an apparent lack of grief and sorrow. Chronic depression is a sort of greater degree of severity compared with delayed mourning. A denial mechanism installs: the loved one is not dead and will return. A split in personality can be observed: part of the person will integrate the reality; the other will retreat from it. In this case, recollection will not lead to integration of the loss. Somatization disorders or organic problems can be observed and more rarely grief melancholia, mania, hysteria or obsessional grief. These are the domain of the specialist. GENERAL PRINCIPLES FOR THE PHYSICIAN: Reality is always preferable to imagination. Listening to the patient must precede any medication. In severe cases of grief, sedative antidepressors are preferable and the co-prescription of anxiolytics, particularly benzodiazepines should be avoided. One should not hesitate to seek advice from a specialist.

Depression↗
PubMed2001

[Depression in the elderly. Clinical aspects].

DIFFICULT DIAGNOSIS: Depression in the elderly can take on many often misleading aspects. Sadness may be considered legitimate or "normal" for an elderly person. Depression may masquerade as an organic disorder where somatic complaints, pain and anxiety predominate. All these different clinical forms may mislead the clinician. THE MASK OF HYPOCHONDRIA: A tendency to hypochondria, found in more than one-half of all depressed elderly subjects, may be reinforced by bouts of complementary examinations. The patient is convinced of having an unrecognized organic disease. The mask of hypochondria must be considered with special care because it is a major risk factor for attempted and successful suicide. THE MASK OF DELUSIONS: Elderly patients often develop a state of melancolia-like depression with delusions. Delusions may be congruent with the predominant depressed mood, for example a guilt feeling for an act never committed, or inversely, non-congruent with the thymic state (persecution, negation delusin), for example Cotard syndrome where the patient is persuaded that his/her organs are malfunctioning or have disappeared. Despite these impressive mood disorders that often incite prescription of a neuroleptic, these elderly patients respond favorably to antidepressor treatment.

Aged↗
PubMed2001

[Depression in the elderly. Principles of treatment].

DRUG THERAPY: Drug therapy must be reassessed regularly to avoid overdosing or poor observance. Use of multiple drugs must be carefully monitored. PSYCHOTHERAPY: Listening to the patient and establishing an understanding friendly relationship are essential to successful psychotherapy in the depressed elderly. SUPPORT: Repulsion is common because old age evokes death. The reactions of family and friends may take on many forms, sometimes leading to counter-transfer. EIGHT SIMPLE RULES FOR PRESCRIPTION: Ask key questions. Treat what is essential. Prescribe few drugs starting at low dose. Check observance. Favor good diet and hygiene. Help the patient accept the aging process. Avoid pseudo placebos. Use appropriate dose timing.

Aged↗
PubMed2001

[Depression in the elderly. Medical treatment].

THE ADVENT OF DRUG THERAPY: In 1957, the advent of two compounds caught the attention of clinicians and psychopharmacologist: G 22355 or Tofranil, the leading drug in the tricyclic family, and iproniazid or Marsilid, a non-sedative monoamine oxidase inhibitor. WHAT IS AN ANTIDEPRESSOR DRUG?: Antidepressor drugs are not effective in all domains simultaneously: it takes 7 to 10 days before an effective equilibrium of mood is reached. Adverse effects often occur earlier, but generally fade out or are well tolerated when the antidepressor effect becomes patent. CASE-BY-CASE PRESCRIPTION: Twenty-four different antidepressor drugs are available in France, classed among imipramines, non-imipramines and non IMAO, serotonine and noradrenaline reuptake inhibitors, and specific serotonin reuptake inhibitors. Each class has its own contraindications, adverse effects and precautions for use. Normothymic drugs and mood' regulators are a separate category that constitute considerable progress for the treatment of relapse and recurrent depression.

Affect↗
PubMed2001

[Depression in the elderly. Rigorous evaluation of drug treatment].

CONSENSUS: There is a general consensus on two points: it takes about 2 months for symptoms to resolve; treatment for 4 to 6 months thereafter reduces the risk of relapse. The same dose should be used for both periods. Likewise for prophylaxis against recurrent depression (long-term treatment for several years). QUALITY CARE: There are three major risks in elderly patients with depression: relapse, chronic depression, suicide. Improved quality care for depressive patients is a major public health issue. It is essential to recognize affected patients who require regular care in order to reduce the risk of non-observance (30-70% of the cases). PRESCRIPTION RULES: Differentiate minor depression from major depression. Wait 7 days before evaluating drug efficacy. Be aware of the risk of desinhibition. See the patient and his/her relations often. Take steps to prevent suicide using appropriate drugs. Favor psychological counseling. Use single-drug regimens preferentially. Prescribe for a sufficiently long period (life?).

Aged↗
PubMed2000

[Did the Erve Valley in Mayenne (the Armoricain Massif, France) play the role of a refuge station during the last (Weichsélien) glaciation?].

Palynological analysis of the basal sedimentary sequence of a peat bog in the upper northeastern part of Mayenne (Massif Armoricain, France) revealed the existence of two temperate oscillations towards the end of the Weichselian glaciation, which were related chronologically by AMS C14 dating to the Kesselt and Tursac interstadials already reported at cave sites. Pollen diagrams recorded mesothermophilic arboreal taxa apparently disseminated from a refuge station possibly corresponding to the Erve valley.

Climate↗
PubMed1999

Quantitative structure-activity relationship of human neutrophil collagenase (MMP-8) inhibitors using comparative molecular field analysis and X-ray structure analysis.

A set of 90 novel 2-(arylsulfonyl)-1,2,3, 4-tetrahydroisoquinoline-3-carboxylates and -hydroxamates as inhibitors of the matrix metalloproteinase human neutrophil collagenase (MMP-8) was designed, synthesized, and investigated by 3D-QSAR techniques (CoMFA, CoMSIA) and X-ray structure analysis. Docking studies of a reference compound are based on crystal structures of MMP-8 complexed with peptidic inhibitors to propose a model of its bioactive conformation. This model was validated by a 1. 7 A X-ray structure of the catalytic domain of MMP-8. The 3D-QSAR models based on a superposition rule derived from these docking studies were validated using conventional and cross-validated r2 values using the leave-one-out method, repeated analyses using two randomly chosen cross-validation groups plus randomization of biological activities. This led to consistent and highly predictive 3D-QSAR models with good correlation coefficients for both CoMFA and CoMSIA, which were found to correspond to experimentally determined MMP-8 catalytic site topology in terms of steric, electrostatic, and hydrophobic complementarity. Subsets selected as smaller training sets using 2D fingerprints and maximum dissimilarity methods resulted in 3D-QSAR models with remarkable correlation coefficients and a high predictive power. This allowed to compensate the weaker zinc binding properties of carboxylates by introducing optimal fitting P1' residues. The final QSAR information agrees with all experimental data for the binding topology and thus provides clear guidelines and accurate activity predictions for novel MMP-8 inhibitors.

Collagenases↗
PubMed1995

Polysyndactyly and asymptomatic hypothalamic hamartoma in mother and son: a variant of Pallister-Hall syndrome.

We report on a 53-year-old woman and her 20-year-old son who both presented with polysndactyly, without other external malformations or mental retardation. MRI imaging revealed, as an incidental finding, asymptomatic hypothalamic hamartomas in both patients. The siblings of both mother and son are unaffected. This family may represent an autosomal dominant variant of Pallister-Hall syndrome.

Abnormalities, Multiple↗
PubMed1994

Tumor necrosis factor-alpha levels and weight loss in chronic obstructive pulmonary disease.

Unexplained weight loss is common in chronic obstructive pulmonary disease (COPD). Blood levels of tumor necrosis factor-alpha (TNF-alpha), a cytokine causing cachexia in laboratory animals, are elevated in various human diseases associated with weight loss. We therefore prospectively measured TNF-alpha serum levels (immunoradiometric assay) in patients with clinically stable COPD (n = 30; all male; mean age, 65 yr) whose weight was less (Group I; n = 16) or more (Group II; n = 14) than the lower limit of normal taken from Metropolitan Life Insurance Company tables. The patients had no cause known to elevate TNF-alpha serum levels; notably, they were not infected. Group I patients had unintentionally lost weight during the previous year, whereas the weight of Group II patients had not changed during the same period. The two groups had similar chronic airflow obstruction and arterial blood gas impairment; hyperinflation and reduction in diffusing capacity were more pronounced in Group I, but differences were not significant. TNF-alpha serum levels (pg/ml; mean [SD]) were significantly higher in Group I than in Group II (70.2 [100.0] versus 6.7 [6.4]; p < 0.001). Group II TNF-alpha serum levels did not differ significantly from those of healthy subjects (7.8 [3.9]), whereas those of Group I were significantly higher (p < 0.001). Because renal function was in the normal range, we conclude that increased TNF-alpha production--and not decreased TNF-alpha clearance--is a likely cause of weight loss in patients with COPD.

Aged↗