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Biomedical subjects

C Levy

Publications and source records attributed to C Levy.

At least 91 records · Page 5Linked to original sources
PubMed1991

[Conflicting xenograft. Role of preoperative total lymphoid irradiation].

This study deals with an experimental model of discordant cardiac xenograft between 24 donor lambs of the Préalpes race and 24 recipient Camborough pigs divided up into 4 groups: I control (6) without immunosuppressive treatment; II (5) with pharmacological immunosuppression (IP); III (13) with PI and total lymphoid irradiation (TLI) and immediate graft, divided up into IIIa (5) with high-rate (HR) TLI and IIIb with low-rate (LR) TLI; IV (4) with a two-week lapse between TLI and grafting. The best graft survival rate (GSR) is obtained either after delayed LR-TLI or after LR-TLI without delay. This study seems to be the first one demonstrating that for discordant xenogenic grafts, TLI associated to PI with cyclosporin A (Cy A) significantly prolongs the survival of the graft (30 times).

Animals↗
PubMed1991

Nocardia asteroides infection following scleral buckling.

We report a case of delayed external ocular Nocardia asteroides infection following scleral buckling for rhegmatogenous detachment. Surgical removal of the exoplant material allowed isolation and identification of the organism. Topical and systemic antibiotic therapy following exoplant removal yielded a favorable result.

Aged↗
PubMed1990

Ethanol and opiate decrease the axonal transport of substance-P like immunoreactive material in rat vagus-nerves.

Since an enhanced retrograde axonal transport of receptor-bound opiate was observed in the ligated vagus nerves of rats treated chronically with alcohol, we decided to look at the anterograde axonal transport of substance P in the same experimental conditions and, after opiate administration. From 1 day up to 24 days' treatment with alcohol, we observed a decrease in the accumulation of substance P like immunoreactive material (SPLM) in rat ligated vagus nerves. Acute administration of lofentanil, an mu opiate agonist, caused the same reduction of anterograde axonal transport of SPLM and this effect could be prevented by naloxone. When naloxone or bezitramide, an opiate agonist, was given during the alcoholization period, the preference for alcohol in a choice test was reduced or prevented suggesting that opioid peptides are probably involved in chronic alcoholism. The present results support the idea that a common denominator could exist in drug addition and in chronic alcoholism and that substance P may be directly or indirectly involved.

Analgesics↗
PubMed1990

Axonal transport of synaptic vesicles and muscarinic receptors: effect of protein synthesis inhibitors.

The effect of cycloheximide, a protein synthesis inhibitor, was studied on the axonal transport of noradrenergic synaptic vesicles and presynaptic muscarinic receptors, identified by in vitro binding of [3H]dihydrotetrabenazine and [3H]quinuclidinylbenzilate, respectively, in rat sciatic nerve. Cycloheximide (1.5 mg/kg) administered subcutaneously 2 h before ligation decreased by approximately 50% the accumulation of vesicles and receptors in the proximal segment above the ligature placed on the nerve; its action was detectable after a lag period of 10 h and disappeared 96 h after administration. Double ligatures were placed on the nerve at various time intervals between the first (distal) and the second (proximal) ligature, and the accumulation of vesicles and receptors proximal to the second ligature was measured; the first ligature diminished the accumulation above the second ligature. At an interval of 96 h between the first and the second ligature, cycloheximide completely prevented the accumulation of vesicles and receptors proximal to the second ligature. The effects of double ligatures and the response to cycloheximide treatment can best be explained on the assumption that an important proportion of synaptic vesicles and presynaptic receptors is being recycled in the nerve cell bodies after retrograde transport.

Animals↗
PubMed1990

Plasma levels of 3-methoxy-4-hydroxyphenylglycol in depressed patients compared with normal controls.

Plasma levels of total 3-methoxy-4-hydroxyphenylglycol (MHPG) were measured in a group of 104 hospitalized depressed patients and a group of 104 age- and sex-matched normal controls. Plasma MHPG levels were found to be normally distributed in both groups and significantly lower in depressives than in controls. However, this difference could be related to an increase in plasma MHPG levels with age found in controls (r = 0.601, d.f. = 102, p less than 0.01) but not in depressives (r = 0.013, d.f. = 102, NS). Men had significantly higher levels than women in both groups. There was no significant difference in plasma MHPG levels among any DSM-III-R diagnostic subgroups of depressives or between patients who were suppressors on the dexamethasone suppression test and those who were nonsuppressors. Significant correlations were found between AMDP Depression Rating Scale item and total scores and levels of plasma MHPG. Age, sex and clinical symptoms appeared to be main sources of variance in studying depressed patients and comparing them with normal controls.

Adult↗
PubMed1990

[Rapid imaging in orbito-ocular pathology. Contribution of gadolinium].

To evaluate Gradient-Echo Imaging (GEI) in orbito-ocular pathology, 15 volunteers and 34 patients (40 lesions) were examined with GEA T1 and GEA T2 (0.5 T). Results were compared with SE T1 in all cases, with SE T2 in 20 cases and with other imaging modalities (CT). 30 patients were examined before and after injection of gadolinium. Final diagnosis was obtained by surgery or biopsy in 24 cases or by combined results of imaging and clinical findings in 16 cases. Compared with SE, GEA demonstrated a better visualisation of optic nerve, orbital muscles, choroidal-retinal layer, lens capsule and episclera and a better detection of small lesions. It is very helpful for characterisation of lesions containing hemorrhages or paramagnetic components (melanine, gadolinium) or of vascular nature (angioma). Gadolinium was useful for detection of small lesions or characterisation of a few lesions. Thus GEA seems to be an efficient method for the evaluation of orbito-ocular pathology.

Adolescent↗
PubMed1989

Structural alterations and breaking strength of mouse femora exposed to three activity regimens.

Mice were used as a model system to correlate loading, changes in cortical and trabecular bone growth and remodeling, and differences in breaking strength of the whole femur. BALB/c mice were raised for 30 days, starting at day 14, under three conditions of loading or exercise: (a) normal exercise control (NE), (b) 4 x normal gravity for a total of one h/day in addition to normal exercises (HG), and (c) chronic digging and burrowing (high-litter cage) (HL). Results indicate that both HG and HL groups significantly increased the cortical cross-sectional area of the mid-shaft of the femur, the moment of inertia in the antero-posterior direction at the mid-shaft, anterior wall thickness of the midshaft cross section, and changed the architecture of trabecular bone in the proximal one-third of the femur. The extent of these structural changes, however, was unique in each group. The HG group (high-intensity, short duration loading) demonstrated the greatest structural changes in the moment of inertia in the antero-posterior direction, which increased by 44% over the control (p less than .001), and in the architecture of trabecular bone. The HL group (lower-intensity, chronic exercise), demonstrated the greatest structural change in cortical bone cross-sectional area, which increased by 27% (p less than .0001). Despite the differences in loading and structural changes in the HG and HL groups, the breaking strength of the whole femur for both groups was approximately 64% greater than the controls (p less than .0001). A mechanical analysis of our data revealed that for our tests the contribution of bending to the total stress on the shaft may be over 50 times greater than that of either compression or tension. Further, the change in the geometry of the cortical bone may account for only approximately 50% of the increase in breaking strength; the remaining increase must be accounted for by changes in material properties and/or placement of trabeculae within the lumen of the shaft.

Animals↗
PubMed1989

High affinity acceptor sites in guinea pig brain for [3H]52770 RP, a PAF antagonist.

[3H]52770 RP, a PAF antagonist, was found to bind with high affinity and in a reversible manner on specific and saturable binding sites in guinea pig cortical membranes. Scatchard analysis revealed the presence of one class of binding sites with an equilibrium dissociation constant of 0.38 nM and a Bmax of 1190 fmol/mg protein. However, these binding sites did not correspond to the PAF receptors described with this ligand in platelet plasma membranes; indeed, PAF and its analogs were unable to displace [3H]52770 RP binding in guinea pig brain. Therefore, one may conclude that [3H]52770 RP in guinea pig brain labels acceptor or recognition sites, rather than true receptor sites.

Animals↗
PubMed1989

[Intraocular pressure during vitrectomy in the diabetic patient].

23 eyes underwent vitrectomy for diabetic proliferative retinopathy complications: vitreous hemorrhage with or without tractional retinal detachment. After 6 months of follow-up, 64% of eyes had final visual acuities of 1/40 or better. Preoperative iris neovascularization and preoperative detachment of the macula have a worse prognosis. Decrease of peroperative complications is allowed by checking of intraocular pressure during vitrectomy.

Adolescent↗
PubMed1989

[Intraocular pressure during vitrectomy in diabetic patients].

23 eyes underwent vitrectomy for diabetic proliferative retinopathy complications: vitreous hemorrhage with or without tractional retinal detachment. After 6 months of follow-up, 64% of eyes had final visual acuities of 1/40 or better. Preoperative iris neovascularization and preoperative detachment of the macula have a worse prognosis. Decrease of peroperative complications is allowed by checking of intraocular pressure during vitrectomy.

Adolescent↗
PubMed1989

Molecular deletion patterns in Duchenne muscular dystrophy patients.

We have studied 30 French patients with X-linked muscular dystrophy of the Duchenne (DMD) and Becker (BMD) types for intragenic deletions, using the cDNA probes of the DMD/BMD gene. Sixteen patients (53%) had molecular deletions in one or several of the 65 Hind III fragments containing exons detected with the DNA probes; in four deletion cases junction, fragments of altered size were seen. Fourteen (87%) of the deletions were detected using only two (1-2a and 8) and fifteen with 8+(2b-3) of the cDNA subclones. In our limited sample, BMD was caused by deletions in the 5' end of the gene, and in two instances of DMD, deletions of similar types resulted in diseases of similar severity. Of two patients with mental retardation, both had deletions comprised exons contained in probe 8, but other patients without mental retardation are also deleted with probe 8. We conclude that cDNA hybridization studies provide a powerful diagnostic tool in DMD and BMD families.

Chromosome Deletion↗
PubMed1989

[Nosocomial sinusitis and nasotracheal intubation. Prospective study of 53 patients].

The authors studied the frequency of sinusitis in nasotracheally intubated patients in an Intensive Care Unit. All patients intubated nasotracheally during an 8 day period were included in a prospective study which included CT scanning with views of all the paranasal sinuses. Sinusitis was defined as opacification of the sinus with an air-fluid level. Transantral punctures were performed in cases of maxillary sinusitis. Fifty-three patients were included. Local symptoms and/or unexplained fever were present in 22% of cases. CT scanning showed sinusitis in 49 of the 53 cases (pansinusitis 42 cases, maxillary alone 5 cases, sphenoidal 16 cases). Bacteriological cultures of sinus punctures were positive in 39 cases, monomicrobial in 21 and polymicrobial in 18 cases. Twenty of the 53 patients developed a lower respiratory tract infection with the same germ and 10 developed septicemia (3 with isolated sinusitis and 7 with pneumonia). Eighteen patients died (6 of their infection and 12 of the underlying disease). This study shows the high frequency of bacterial sinusitis and the necessity of sinus puncture for bacteriological identification of the causal organism to adapt antibiotic therapy.

Aged↗