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Biomedical subjects

P Neveu

Publications and source records attributed to P Neveu.

At least 19 recordsLinked to original sources
PubMed1992

Prolonged increase of corticosterone secretion by chronic social stress does not necessarily impair immune functions.

The influence of a chronic social stress upon immunity was investigated in Wistar rats, submitted for four weeks to two different behavioral situations, balanced in a factorial design: housing with three females and membership rotation. The combination of these two factor led to adrenal enlargement (43.3%), thymus involution (39.5%) and increased basal corticosterone levels, all indices of activation of the hypothalamic-hypophysis-adrenal axis. However, neither natural killer cell activity, splenocyte reactivity to mitogen nor the rate of spontaneous development of antibodies against Mycoplasma pulmonis, a common pathogen of the respiratory tract, were changed in the endocrine activated animals. Analysis of the data on kinetics of stress at 1, 7 and 28 days after the initial mixing of the animals gave the same results. These data question the immunosuppressant activity usually conferred to corticosteroids, at least when adrenal hyperactivity is induced by chronic environmental stressors.

Adrenal Glands↗
PubMed1991

Evaluation of the immunomodulatory potential of diethyl dithiocarbamate derivatives.

The cytotoxicity, immunotoxicity and immunomodulatory potential of four dithiocarbamate derivatives were assessed and compared with the effects of Immuthiol (diethyl dithiocarbamate, DE-DTC) in mice. Cellular stimulation and cell viability were examined after in vitro exposure of spleen lymphocytes to selected DTC analogues: N-methyl-D-glucamine dithiocarbamate (NMG-DTC), dimethyl dithiocarbamate (DM-DTC), dibuthyl dithiocarbamate (DB-DTC) and diisobuthyl dithiocarbamate (DIB-DTC). Lymphocyte activation by plant and bacterial mitogens: concanavalin A (Con A), phytohaemagglutinin (PHA), lipopolysaccharide (LPS) and allogeneic stimulation of cells in mixed lymphocyte reaction (MLR) were examined in vitro in the presence of 10(-4)-10(-9) g/ml DE-DTC and other selected DTC derivatives. No direct in vitro lymphoproliferative activity of DTC derivatives was observed, although a relatively stronger cytotoxicity with DE-DTC and DM-DTC was noted. In addition, the in vivo effects of DTC derivatives were examined by cytofluorometric profile of splenic and bone marrow cells as well as in mitogenic and allogenic responses, after i.v. exposures of animals to two subsequent (25 mg/kg b.w.) doses of the chemical. Less cytotoxic DIB-DTC, NMG-DTC and DB-DTC expressed weak in vivo immunostimulatory potential when compared with the effect of DE-DTC, whereas the effects of DM-DTC on alloantigenic and mitogenic lymphocyte stimulation were comparable with the known effects of DE-DTC. Cytofluorometric studies showed that the number of cytotoxic/suppressor T-cells (Ts) and helper T-cells (Th) in the cell was increased by DE-DTC and NMG-DTC only. In addition, DM-DTC appeared to affect the Ts/Th ratio. DE-DTC did not affect the B-cell subpopulation, whereas other derivatives induced marked modifications of the pre-B-cell subpopulations in bone marrow. Our data suggest that in vivo the immunostimulatory effect of DM-DTC could be accompanied with major changes in bone marrow B-cell frequency and alteration of spleen Ts/Th ratio.

Adjuvants, Immunologic↗
PubMed1986

[Evaluation of the neurological risk of asymptomatic carotid stenosis and discussion of the value of carotid surgery in stage 0. Apropos of a study of 123 obliterative lesions].

The authors analyzed neurological risk on the basis of the study of 123 asymptomatic obstructive carotid lesions. Patients were divided into two groups: Group A (54 patients undergoing prophylactic endarterectomy). Group B (69 patients not undergoing surgery). Definition of the carotid lesion was based upon a combination of Doppler, sonography and arteriography results. Assessment of comparative neurological risk, on the basis of a hemodynamic definition of the stenosis, in the two patient groups, led to definition of appropriate management of an asymptomatic carotid stenosis. In group A, operative mortality was nil and there was one transient ischemic accident. In group B, there were 12 accidents, 9 transient and 3 permanent. In this latter group there was one neurological death, i. e. mortality of neurological origin of 1.5%. Evaluation of risk initially requires definition of the stenosis. The presence of a carotid bruit alone is inadequate. Doppler and sonography, followed where necessary by arteriography, define the degree of stenosis which is the primordial prognostic feature. The difference of risk between a population undergoing surgery or not is statistically significant, in particular in hemodynamically tight stenosis. Finally, the degree of stenosis influences the severity of any subsequent accident, although this has not been proved statistically. In the majority of cases, the initial accident would appear to be regressive. In total, 4 concepts have been defined: the risk of carotid surgery at stage 0 is low, being of the order of 0. Overall neurological risk is less in the long term in asymptomatic patients who have undergone surgery than in those who have not been operated upon.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1986

[Evaluation of the surgical risk in surgery of aneurysms of the abdominal aorta. Therapeutic deductions. Apropos of a retrospective study of 250 surgically treated aneurysms].

A retrospective study of 250 patients operated upon for infrarenal abdominal aorta aneurysm provided data for evaluation of the surgical risk as a function of three developmental situations: asymptomatic aneurysms, aneurysms evolving by subacute symptomatology and ruptured aneurysms. Mortality varied as a function of group, being 3% for the asymptomatic group, 21% for evolving aneurysms and 69% for ruptured aneurysms. Perioperative mortality was related to age and cardiovascular risk factors. Various clinical and pathologic aspects as well as means of follow up review are discussed, allowing definition of therapy as a function of previous clinical status and evolution of the aneurysm.

Adult↗
PubMed1985

[Role of reconstructive surgery in post-traumatic occlusions of the renal artery. Apropos of a case].

Post-traumatic thrombosis of the renal artery was detected in a patient with multiple injuries. Based on findings in this case and those reported in the literature, the difficulties of early diagnosis, the viability of the renal parenchyma and the hypertensive risk of revascularization are discussed and an attempt made to define the place of arterial surgery in post-traumatic thrombosis of renal artery.

Abdominal Injuries↗
PubMed1983

[Echographic study in the exploration of supra-aortic trunks. Comparative study with doppler velocimetry and their respective roles in functional vascular explorations].

Over the last six months, 1,311 doppler examinations of the supra-aortic trunks have been performed with confrontation doppler, ultrasound, arteriography and intra-operative examination according to the cases. We studied these cases with the following questions in mind: Does real time ultrasound of the supra-aortic trunks give more valuable information than the classical doppler examination? Is the diagnosis simplified? Is the therapeutic management altered? We are able to conclude: 1. In the case of a mildly stenotic plaque (less than 50%), the doppler examination gives an acoustic and graphic representation which is rich and not differentiated for stenoses of between 10% and 50%, which corresponds to an ultrasound plaque of 1 mm to 4-5 mm: the ultrasound supports the diagnosis. 2. However, in stenoses greater than 50%, there is good correlation between the doppler examination, ultrasound and arteriography. Ultrasound enables the exact extent of the plaque to be visualised in sagittal and transverse planes. It can diagnose aneurysmal lesions and suggest ulcerated lesions. 3. Finally, the doppler examination seems to be indispensable in cases of pre-thrombosis or fresh thrombosis of the carotid. Ultrasound can be negative at this early stage.

Adult↗
PubMed1983

[Vascular complications of cervical ribs. Apropos of 15 cases].

Anatomical, etiopathogenic, clinical, and paraclinical aspects of vascular complication of cervical rib are discussed based on findings in 15 cases. Emphasis is placed on the value of newly available non-invasive functional tests, such as computerized angiography and particularly ultrasonography, which can modify surgical conduct. Operative technique is described, and indications for surgery and short- and long-term results obtained presented. Evaluation of results reported in the literature shows that they were excellent in 75 to 93% of cases, recent studies indicating an even higher rate of improvement.

Adolescent↗
PubMed1982

Intrauterine growth charts for twin fetuses.

In addition to centile curves for birth weight and height of single infants, the authors offer similar biometric references for twins derived from a large French data base. The aim of the work is to assist in discovering small-for-date twins. In the actual prenatal environment, the curves show a decrease in the evolution of these growth parameters in comparison with the single pregnancy standards as early as the 30th week of pregnancy.

Anthropometry↗
PubMed1982

[Iliocaval venous thrombosis. Clinical and paraclinical aspects and therapeutic approach, apropos of 58 cases].

The authors report 58 cases of ilio-femoral and ilio-caval thrombosis and emphasise the considerable contribution of two vascular function tests: Doppler and occlusion rheoplethysmography, which now compensate for clinical deficiencies. Nevertheless, phlebography remains essential in defining management which is based upon age, general condition, and the site and type of thrombosis (floating or adherent clot). An outline therapeutic approach is suggested on the basis of these data.

Female↗
PubMed1981

[Echotomography in nephroblastoma and neuroblastoma of the lumbar fossa in childhood. Comparison with intravenous pyelography and computerized tomography (author's transl)].

The respective values of intravenous pyelography, ultrasound examination and computerized tomography are compared with the findings at surgery and with histological data in 28 children with malignant tumors of the lumbar fossa. Ultrasound proved to be of significant value in assessing the extent of the tumor. At the present time, computerized tomography is only indicated when intravenous pyelography and ultrasound examination fail to provide adequate information.

Angiography↗
PubMed1979

[Indications and results of dorsal sympathectomy in vascular syndromes of the upper limb (author's transl)].

The authors report 50 cases of dorsal sympathectomy followed up on the cardiovascular surgery unit of the Amiens University Hospital over a period of six years. The authors then formulate a number of reflexions concerning the clinical findings, the therapeutic indications, and the way of assessing the results of this operation in vascular syndromes of the upper limb. This is a plea in favour of this operation as, in most cases, no other treatment is comparable.

Adolescent↗