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Biomedical subjects

C Rey

Publications and source records attributed to C Rey.

At least 19 recordsLinked to original sources
PubMed1997

Colonic xanthelasma due to glyceride accumulation associated with an adenoma.

The case is reported of a 66-year-old woman who presented with endoscopic and histological features of multiple lipid deposits in the mucosa of the sigmoid colon associated with an adenoma. Associated clinical features were abdominal pain and diarrhea. Colectomy led to the complete resolution of symptoms. Biochemical analysis disclosed the presence of glycerides in the mucosa. The pathogenesis of lipid deposits and the possible link with the formation of an adenoma is discussed.

Adenomatous Polyps↗
PubMed1996

Variation in the inflammatory properties of basic calcium phosphate crystals according to crystal type.

OBJECTIVE: To determine the inflammatory potential of basic calcium phosphate (BCP) crystals, which have been identified in human joints. METHODS: Hydroxyapatite, carbonate apatite, whitlockite, and octacalcium phosphate crystals were injected in rat air pouches. Volume and cellularity of the exudate were measured. Physicochemical properties of the injected BCP crystals were determined, and correlations with the magnitude of induced inflammatory responses were sought. RESULTS: Significant differences were observed among the volumes and white blood cell (WBC) counts of the pouch exudates, based on the various crystal types used to induce inflammation. A strong correlation was demonstrated between the specific surface (SS) area of the injected crystals and the area under the curve for induced WBC count versus time (R2 = 0.88, P = 0.05). This correlation was observed for SS area values below 50 m2/gm, but when SS area increased further, this parameter plateaued. Another parameter of inflammatory response was obtained by dividing the area under the curve figuring WBC counts versus time by the corresponding SS area for each crystal type. This parameter increased linearly with the Ca:P ratio (R2 = 0.97, P = 0.0003). CONCLUSION: The inflammatory potential of BCP crystals appeared to vary according to crystal features. SS area and the Ca:P ratio (which correlates with crystal solubility) influenced inflammatory properties. These results could explain the variable clinical consequences of BCP deposits, and must be taken into account in the choice of apatite ceramics for use as biomaterials.

Animals↗
PubMed1996

Acquisition of syncytium-inducing HIV-1 strains during therapy with zidovudine alone or combined with alpha interferon or didanosine.

The effect of antiretroviral treatment on HIV-1 phenotype was studied in a group of 83 nucleoside-naive patients. These initially nonsyncytium-inducing HIV-1 positive patients were followed prospectively for their HIV-1 phenotype. Syncytium-inducing variants were detected by cocultivation of peripheral blood mononuclear cells with the MT-2 T-cell line. Overall, 16 of 83 (19%) patients underwent a shift to syncytium-inducing phenotype: 11 of 67 during zidovudine treatment, 3 of 10 during zidovudine plus alpha interferon treatment, and 2 of 6 under initial zidovudine plus didanosine therapy. The results of this study demonstrate that neither zidovudine therapy alone nor combined with interferon or didanosine prevents the acquisition of syncytium-inducing strains.

Adult↗
PubMed1996

X-ray diffraction, electron microscopy, and Fourier transform infrared spectroscopy of apatite crystals isolated from chicken and bovine calcified cartilage.

Apatite crystals of the calcified zone of the subarticular cartilaginous growth plates of the long bones of young growing chickens and calves were isolated by low temperature reaction with hydrazine and plasma ashing and examined by electron microscopy, electron diffraction and microprobe analysis, and computer-generated deconvolution of the spectra obtained by Fourier transform infrared spectroscopy. The crystal habit was that of wide, very thin, relatively long rectangular plates, which tended to form small clusters of crystals, possibly because reaction with hydrazine alone did not remove all of the organic matrix constituents. Further reaction with low power plasma ashing released more of the isolated crystals although to a lesser extent than was possible with bone. Stereograms of the small clusters showed that many of the crystals in the small isolated aggregates of crystals were bent and/or curved. Together with the resultant overlap of individual adjacent crystals, they also produced images of sharp, very dense lines, reminiscent of the electron-dense needle or rod-like appearances frequently observed by transmission electron microscopy of thin sections of calcified cartilage and thought to represent the habit of the apatite crystals. No true rod or needle-like crystals were observed in the isolated crystals. Although the overall general apatitic structure of the apatite crystals was similar to that of the apatitic crystals of bone, the individual crystals were significantly larger than those of bone from the same specimen, and there were small but significant differences in the concentrations of acid phosphate and carbonate groups and in their short range order.

Animals↗
PubMed1996

Occlusion of large atrial septal defects with a centering buttoned device: early clinical experience.

A feasibility clinical study was conducted for the transcatheter occlusion of large ostium secundum atrial septal defects with the centering buttoned device. The centering buttoned device is a modification of the regular buttoned device in which a centering counter-occluder is sutured at the central 40% portion of the occluder. During centering it is stretched, forming a parachute-shaped structure and pulling the occluder over the center of the defect. During buttoning, the counter-occluder forms a double figure eight, opposing the right atrial side of the atrial septum. Occlusion was performed in 12 patients aged 6 to 56 years. All had been rejected for transcatheter occlusion by the regular buttoned device, because of either their defect size or the lack of adequate septal rim. The defect size varied between 23 and 31 mm, and the device size varied between 45 and 60 mm. Nine had immediate effective occlusions of their defects and three residual shunts. One patient with unbuttoning had hemolysis at 2 weeks and underwent surgery. Early results of the transcatheter occlusion of large atrial septal defects are promising, and larger clinical trials are justified.

Adolescent↗
PubMed1996

Rate of development of mutation at codon 215 of HIV-1 reverse transcriptase and its predictive factors at the time of initiation of zidovudine therapy.

The objective of the present study was to determine the rate of development of mutation at codon 215 of HIV-1 reverse transcriptase and to identify baseline characteristics associated with this mutation following initiation of zidovudine therapy. To achieve such a purpose, 80 HIV-1-infected patients starting zidovudine therapy have been submitted to clinical, immunological and virological monitoring at entry and every 12 weeks. The critical end point of the study was time to development of mutation at codon 215. The association of key baseline characteristics (CD4+ counts, clinical stage, HIV-1 p24 antigen, CD8+ counts, serum beta 2-microglobulin and virus phenotype) with the mutation at codon 215 was also investigated. A total of 38 subjects (48%) developed mutation at codon 215 during follow-up. The estimated Kaplan-Meier probability of remaining with wild genotype at 24, 48 and 96 weeks (96% CI) was 0.82 (0.73-0.90), 0.70 (0.60-0.80) and 0.53 (0.41-0.66) respectively. Univariate analysis showed that time to the development of mutation at codon 215 was positively associated with baseline p24 positivity, C clinical stage, low CD4+ count and high beta 2-microglobulin level. Only p24 antigenaemia and CD4+ count remained significantly independent predictive factors for the development of mutation at codon 215 in the Cox proportional hazard stepwise regression analysis [risk ratio (95% CI): 3.67 (1.75-7.70), P = 0.0007; 2.89 (1.17-6.72), P = 0.0073 respectively]. Thus, a continuous emergence of mutation at codon 215 was observed and HIV-1 p24 antigenaemia should be considered an independent predictor for faster development of zidovudine resistance.

Adolescent↗
PubMed1996

HIV-1 viraemia changes in patients with and without syncytium-inducing phenotype treated with nucleoside analogues: a case-control study.

The objective of the present study was to investigate the effect of the nucleoside analogue treatment on serum viraemia, CD4+ cell count and disease progression in patients with and without syncytium-inducing (SI) HIV-1 variants. To achieve this in a case-control study, 11 nucleoside-naive patients harbouring SI variants who started treatment with zidovudine or zidovudine plus didanosine were matched with 11 control patients who never formed SI variants during a follow-up of 48 weeks. The matching criteria were age, CD4+ cell count and CDC clinical category at the start of the study and exposure to the same antiretroviral treatment. During the follow-up there were no significant differences in the changes of serum HIV-1 RNA viral load and CD4+ cell counts between the two groups. In contrast, AIDS or new AIDS-defining events were observed in five SI cases but in none of the non-SI controls (P = 0.002). The emergence of a zidovudine-resistant mutation at codon 215 was observed in all the patients harbouring SI strains and in six of the subjects with non-SI variants (P = 0.03). The results of the present study show that in patients carrying SI virus, measurements of CD4+ count or RNA viral burden are neither related to the virulence of the virus strains nor able to predict the clinical course of the disease, at least under anti-retroviral drug conditions. Thus, determination of SI phenotype should be considered in the evaluation and monitoring of HIV-1 therapies.

Acquired Immunodeficiency Syndrome↗
PubMed1996

Chronic renal failure and human growth hormone treatment do not modify endothelium-dependent reactions in the rat aorta in vitro.

1. Growth hormone (GH) increases glomerular filtration rate and renal plasma flow and decreases renal vascular resistance. Sustained GH-induced hyperfiltration might be undesirable in children with chronic renal failure (CRF) who are receiving recombinant human GH (rhGH) therapy. 2. In order to determine the effect of CRF on vascular reactivity and the modifications induced by rhGH administration, two endothelium-dependent effects, acetylcholine relaxation and decrease of contractile response to noradrenaline, were studied in aorta segments of various groups of male Sprague-Dawley rats: CRF rats (CRF, n = 8) with serum urea nitrogen (SUN) 68 +/- 16 mg dl-1 (mean +/- SEM), CRF rats treated with intraperitoneal rhGH at 10 IU kg-1 day-1 for 13 days (CRFGH, n = 6, SUN = 88 +/- 15 mg dl-1), sham operated rats (SHAM, n = 8, SUN: 21 +/- 1 mg dl-1) and control rats (CONTROL, n = 8, SUN 20 +/- 1 mg dl-1), housed in identical conditions but without undergoing surgical intervention or manipulation. CRF was induced by 5/6 two stage nephrectomy. 3. Rats were sacrificed and a segment of thoracic aorta was immediately removed, cut into spirals, and suspended in organ baths according to standard procedures. First, dose-response curves to noradrenaline and acetylcholine relaxation, in strips previously exposed to noradrenaline, were determined. Then, the endothelium was removed and both dose-response curves were repeated. Acetylcholine induced a greater relaxation, P < 0.05, in the aorta of CONTROL rats (82.6 +/- 6.1%) as compared with SHAM (60.3 +/- 4.7%), CRF (60.0 +/- 6.8%) and CRFGH (54.8 +/- 8.2%) rats. 4. Endothelium removal only caused a greater contractile response to noradrenaline (10(-9) and 3 x 10(-9)M) in the CONTROL group, P < 0.05. 5. No differences to acetylcholine and noradrenaline responses were found among the SHAM, CRF and CRFGH groups. 6. These results suggest that the endothelium-dependent vascular reactivity was modified by the experimental protocol to induce chronic renal failure but no further changes resulted from uraemia and rhGH treatment.

Acetylcholine↗
PubMed1996

Effects of valproate-induced alteration of the GABAergic system on pulsatile luteinizing hormone secretion in ovariectomized women.

It is well established that valproate increases hypothalamic concentrations of gamma-aminobutyric acid (GABA). Although little research has been done on the role of GABA in the control of pulsatile luteinizing hormone (LH) secretion in humans, our group recently found that administration of valproate had no significant effect on pulsatile LH secretion in late follicular and mid-late luteal phase normal women. However, the results of several studies of rats suggest that GABAergic regulation of LH secretion may depend on steroid levels. The objective of this work was to determine whether regular administration of sodium valproate inhibits pulsatile LH secretion in ovariectomized women. Twelve women who had undergone ovariectomy for causes other than malignant tumors were each studied in two 8 h sessions, in each of which blood samples were taken every 5 min. The first session was the control; for the second. 400 mg of sodium valproate was administered every 8 h during the seven preceding days and at 08.00 h and 14.00 h on the day of the study session. Serum valproate was determined by repolarization fluorescence spectrophotometry, and LH, estradiol and progesterone by radioimmunoassay. The serum LH series were subjected to a deconvolution procedure to reconstruct the pattern of pituitary LH secretion. Luteinizing hormone pulses were identified by the authors' non-parametric method. Control and post-valproate results were compared with regard to number of pulses, pulse duration, the quantity of LH secreted in each pulse, interpulse interval and mean serum LH level. There was no statistically significant difference between control and post-valproate results for any of the variables considered. It is concluded that sustained serum valproate levels do not alter pulsatile secretion of LH in ovariectomized women. This implies that, in humans, GABA is probably not a decisive factor in the regulation of the GnRH pulse generator.

Adult↗
PubMed1996

Assessment of protein intake in children with chronic renal insufficiency.

Daily nitrogen intake was estimated in 19 children, aged (mean +/- SD) 9.9 +/- 5.0 (range: 1-19) years with chronic renal insufficiency (creatinine clearance 47.1 +/- 19.3 ml/min/1.73 m2, range: 11-75) by 31 three-day prospective dietary records (NIDR) and simultaneous 24-hour urine urea excretion (NIUE). Daily nitrogen intake was 11.05 +/- 3.9 g by NIDR and 8.52 +/- 3.3 g by NIUE, and a significant correlation (r = 0.61; p = 0.0003) existed between both methods of measurement. However, the difference in nitrogen intake estimated from dietary records and from 24-hour urine collection (NIDR-NIUE) was 2.5 +/- 3.3 g, greater than the mean estimated nitrogen intake calculated from both methods, (NIDR + NIUE)/2, 95% limits of agreement being +9.1 to -4.1. Thus, NIDR and NIUE values show a good correlation in children with chronic renal insufficiency, although both methods may provide quite a different estimation in a given child.

Adolescent↗
PubMed1996

Analysis of growth in five-sixths-nephrectomized rats.

The present study was designed in an attempt to better define the pattern of growth in five-sixths-nephrectomized rats. Male Sprague-Dawley rats underwent two-stage (days 0 and 7) five-sixths nephrectomy (NX, n = 16) or sham surgery (SHAM, n = 9). At the time of sacrifice (day 21), renal failure (CRF) of NX rats was confirmed by elevated (p < or = 0.0001) serum concentrations (X +/- SEM) of urea nitrogen (SUN) (56 +/- 5 vs. 20 +/- 1 mg/dl) and creatinine (0.7 +/- 0.04 vs. 0.4 +/- 0.02 mg/dl) and reduced SUN (0.13 +/- 0.02 vs. 0.44 +/- 0.05 ml/min/100 g) and creatinine clearances (0.23 +/- 0.02 vs. 0.58 +/- 0.05 ml/min/100 g). As shown by lower cumulative gains of weight (41 +/- 6 vs. 74 +/- 4 g) and length (5.0 +/- 0.4 vs. 6.8 +/- 0.3 cm), NX rats grew subnormally. Detailed analysis of growth data revealed: (1) In spite of being identically matched in weight and length on day 0, at day 7, NX rats already weighed less than SHAM animals (147.1 +/- 2.3 vs. 153.4 +/- 1.9 g, p = 0.03). (2) From day 7 on, daily gain of weight was lower in the NX group only on days 8 (-6.08 +/- 0.52 vs. -1.60 +/- 0.69 g/100 g body weight) and 9 (-0.41 +/- 1.73 vs. 5.18 +/- 0.63 g/100 g body weight). (3) Following the early post-second-nephrectomy period, two subgroups of NX rats were clearly differentiated according to whether or not their daily growth rate was lower than that of SHAM animals. Maintained subnormal growth rate was observed in rats with severe CRF (SUN 73 +/- 5 mg/dl, range 54-90) but not in rats having milder uremia (42 +/- 3 mg/dl, range 31-51). Thus, growth in five-sixths-nephrectomized rats should be reported based on daily weight increments (g/100 g body weight). Subnormal growth can be attributed to CRF provided SUN is at least 3 times as high as normal while growth impairment of rats with less marked reduction of renal function is likely related to transient acute renal failure and postsurgical catabolic state.

Animals↗
PubMed1996

[French experience in the closure of atrial septal defects of the ostium secundum type with the Sideris button occluder].

From February 1992 to November 1995, four French teams used the Sideris button occluder to close 122 ostium secundum, foramen ovale or surgical fenestration atrial septal defects in 121 patients aged 2 to 79 years with body weights of 10 to 96 kg. a left-to-right shunt in 110 cases (average QP/QS = 2.09) or right-to-left shunt in 12 cases. The usual type of prosthesis was used in 115 cases, 8 centered on a guide wire, reverse type in 5 cases and the "centering-device" type in 2 patients. Nineteen implantation attempts were abandoned before releasing the prosthesis. The immediate results were: closure of the atrial septal defect in 116 patients: 59 were completely occluded, 43 had minimal residual shunts. Five patients were operated for non-buttoning or malposition of the prosthesis. In one other case, the device was removed by catheterisation. During follow-up ranging from 1 month to 3 years, 20 patients were operated for varying complications, the commonest of which was malposition of the prosthesis (17 cases) with a shunt of variable volume. In one other case, a second device was inserted. Seventy-seven patients were reviewed at 1 year, 28 a 2 years and 6 at 3 years. The residual shunts decreased with time but only completely disappeared in half the cases. Secondary fractures not requiring surgery were observed in 5 patients. Failures and complications were the result of various causes which are discussed. Successive technological improvements and the experience of the medical teams should reduce this incidence, but caution is required especially in the treatment of young children.

Adolescent↗
PubMed1996

[Percutaneous implantation of endoprostheses in stenosis of the pulmonary branches].

Between July 1992 and October 1995. 10 Palmaz stents were implanted in 6 patients aged 2 to 25 years with stenoses of pulmonary artery branches. The stenoses were located on the right (n = 2) or left pulmonary artery (n = 3) or both branches (n = 1). Stenoses of the right pulmonary artery were secondary to a Waterston (n = 1) or Blalock-Taussig (n = 1) anastomosis or to surgical plasty with Dacron (n = 1). Stenoses of the left pulmonary artery were secondary to surgical plasty with Goretex (n = 2), pericardium (n = 1) or Dacron (n = 1): three of these patients had undergone a left Blalock-Taussig anastomosis before complete correction. After implantation of the stent, the pulmonary artery diameter increased from 4 +/- 2 mm to 11 +/- 2 mm (p = 0.0117) and the transstenotic gradient decreased from 44 +/- 18 to 15 +/- 12 mmHg (p = 0.0277). Similarly, the percentage of homolateral pulmonary perfusion at scintigraphy increased from 22 +/- 13% to 53 +/- 17% (p = 0.0431). There were no deaths. The major complication was migration of the stent, observed in three patients at the moment of implantation in two cases and in the hours following implantation in the other case. In these 3 patients, the embolised stent was left in the pulmonary arteries with no adverse consequences on pulmonary perfusion. Two of these patients later successfully underwent further catheterisation for implantation of another stent. Implantation of a stent is a therapeutic alternative in pulmonary artery stenoses which often recur after surgery and/or angioplasty. They increase the diameter of the stenosed vessel and reestablish the equilibrium of perfusion between the two lungs.

Adolescent↗
PubMed1996

[Percutaneous valvotomy of aortic valve stenoses in children].

A retrospective cooperative study of percutaneous aortic valvuloplasty was undertaken in 12 French centres from 1985 and included 90 children over 3 months of age (average 8.5 +/- 5.2 years) treated for isolated aortic valve stenosis with peak transvalvular pressure gradients of 80.7 +/- 23 mmHg. over 50 mmHg in 92% of cases. The majority of cases were performed by a retrograde femoral arterial approach with inflation of a balloon with a diameter approximating that of the aortic annulus. There was one serious complication (lethal collapse occurring before dilatation) and 12% of local complications due to arterial trauma: the latter were temporary or accessible to simple therapeutic measures. Overall, the pressure gradient decreased by an average of 39.2 +/- 25.4 mmHg. There were 15 immediate failures (17%) and 21 partial results (23%) requiring a further procedure at varying intervals after the valvuloplasty. There were 54 primary successes (60%) with annulation of the pressure gradient and this result was sustained in 45 of the 51 cases followed up for an average of 34 +/- 21 months. Aortic regurgitation was observed or aggravated in 29 children; at the end of the study, this remained a serious problem in 15 cases (17%). The authors conclude that interventional catheterisation is an elegant. simple and relatively economical alternative to conventional surgery. It is as safe, but less immediately effective overall; aortic continence may be compromised in the long-term. In the absence of technical innovations, a parallel development of the two therapeutic procedures is to be expected.

Adolescent↗
PubMed1996

[Percutaneous pulmonary valvuloplasty in neonates and infants with tetralogy of Fallot].

Percutaneous pulmonary valvuloplasty remains controversial as a palliative procedure in Tetralogy of Fallot. This paper reports the results of this technique with respect to clinical improvement and growth of the pulmonary arterial tree. Between June 1990 and July 1995, valvuloplasty with a balloon catheter was performed in 25 neonates or infants with Tetralogy of Fallot (13 girls and 12 boys). All patients were symptomatic with severe cyanosis associated with anoxic malaise in 14 cases. At catheterisation, the children were aged 3.5 +/- 2.6 months and weighted 4.7 +/- 1.2 kg. After dilatation, cutaneous oxygen saturation increased from 75 +/- 11 to 88 +/- 8% (p = 0.001). However, 3 children were referred for early surgery (one complete correction and two systemico-pulmonary anastomoses because of persistent desaturation. There were no lethal complications. A control (catheterisation or surgery) allowed evaluation of the growth of the pulmonary tract, on average 5.5 +/- 4.3 months after dilatation. The pulmonary artery diameter increased from 6.17 +/- 1.26 mm to 8.66 +/- 1.22 mm (p = 0.0015). Expressed as a Z score, the annulus diameter changed from -3.93 +/- 0.91 to -2.54 +/- 1.2 SD (p = 0.0019). The mean Z score of the right pulmonary artery increased from -3.01 +/- 0.69 to -1.98 +/- 1.12 SD (p = 0.0251) and the Z score of the left pulmonary artery from -2.68 +/- 0.85 to -1.61 +/- 1.46 SD (p = 0.0357). At complete correction, 50% of patients had had correction of their malformation without section of the pulmonary annulus. In conclusion, pulmonary valvuloplasty in Tetralogy of Fallot enables growth of the annulus and pulmonary arteries and is a valuable alternative to palliative systemico-pulmonary anastomosis.

Blood Gas Analysis↗
PubMed1996

[Double outlet left ventricle: a rare and unusual cardiopathy. Apropos of 7 new cases].

Double outlet left ventricle is a very rare condition due to an abnormality of conotruncal morphogenesis. The authors report 7 new cases to the 119 already published, one with an anatomical variation not previously described. Three of the cases reported were of the most usual type similating tetralogy of Fallot. Two of these cases underwent complete correction with excellent results 13 months and 2 years after surgery. The third patient aged 6 months is well after initial palliative neonatal surgery. A case with an L-malposition pedicle with subpulmonary ventricular septal defect and pulmonary outflow tract obstruction died after early palliative surgery (Blalock-Taussig). A case with subaortic ventricular septal defect, pulmonary stenosis, and tricuspid atresia, underwent physiopathological correction (Fontan procedure) after a Waterston shunt and is well at 19 years of age. The other two cases presented more unusual anatomical forms aortic outflow obstruction: one had hypoplasia of the aortic arch with an isthmic coarctation requiring a Crafoord procedure in the neonatal period associating with banding followed by complete correction at 19 months of age. After 3 years, the patient is asymptomatic. The last case with atresia of the aortic valve and severe hypoplasia of the ascending aorta died after corrective surgery of first intent. Other cases have been described in the literature with different clinical presentations: absence of pulmonary or aortic obstruction; intact interventricular septum. The anatomical variability is due to the complex embryogenesis of the conotruncal region and explains the clinical diversity of this congenital cardiac malformation.

Aortic Valve↗