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C Noel

Publications and source records attributed to C Noel.

At least 37 records · Page 2Linked to original sources
PubMed1995

Implication of cyclosporine in up-regulation of Bcl-2 expression and maintenance of CD8 lymphocytosis in cytomegalovirus-infected allograft recipients.

T cell homeostasis and CD4/CD8 ratios are normally reestablished by apoptotic clearance of activated T cells after immune stimulation. In allograft recipients with cytomegalovirus infection, CD8 lymphocytosis persists after negativation of viral cultures, contrary to immunocompetent hosts. We investigated the expression of Bcl-2 protein, an intracellular suppressor of apoptosis, and of CD95 (APO-1/Fas), a membrane inducer of apoptosis, in peripheral blood lymphocytes from 45 solid organ recipients. During the viremic phase of CMV infection, we found absence or diminished expression of Bcl-2 protein and increased expression of CD95 antigen in activated CD8+ T cells. Opposite evolution of these molecular regulators of apoptosis was reflected by the presence of 10-25% of apoptotic lymphocytes with fragmented DNA, as shown by both in situ nick translation and electrophoresis. Normalization of Bcl-2 expression was progressive over several months but still lower than in uninfected allograft recipients. These results suggest that the initial evolution of CMV infection in allograft recipients resembles acute viral infection in immunocompetent hosts. Conversely, we showed that overexpression of Bcl-2 protein in lymphocytes from uninfected allograft recipients, and culture of unstimulated normal lymphocytes with 0.5 micrograms/ml cyclosporine led to an increase in the expression of intracellular Bcl-2. This up-regulation of Bcl-2 protein by cyclosporine suggests the acquisition of resistance to apoptosis. Thus, the reversion of balance between T cell death and survival after acute CMV infection might be impeded by cyclosporine. Combination of CMV latent infection and cyclosporine therapy appears therefore critical to shift the homeostatic maintenance of the peripheral lymphocyte compartment toward persistingly high numbers of CD8+ T cells.

Adolescent↗
PubMed1995

Diagnostic and predictive value of an immunohistochemical profile in asymptomatic acute rejection of renal allografts.

We have retrospectively studied the diagnostic and predictive value of immunohistochemical characterization of adhesion molecules (ICAM-1, CD54, VCAM-1) and HLA-DR antigen in a homogeneous clinical group of 36 patients. Between 1 January 1991 and 31 January 1993, 130 patients received a kidney transplant in our unit. Biopsies of renal allografts were only performed in asymptomatic patients who had graft dysfunction, revealed by an isolated serum creatinine increase. Available frozen samples were included in this study (n = 44). The 35 cases of acute rejection diagnosed by biopsy corresponded to mild acute rejection according to the Banff classification criteria. First, we compared the expression of HLA-DR, ICAM-1 and VCAM-1 to morphological data to determine if the immunohistochemical data improved the histopathological diagnosis when the interstitial infiltrate was mild with slight tubulitis. We also studied the phenotype of infiltrating cells with monoclonal antibodies directed against T helper cells, T cytotoxic-suppressor cells, activated T cells and macrophages. Expression on tubular epithelium and density of each type of cell was graded semiquantitatively. Expression of HLA-DR, ICAM-1 and VCAM-1 was observed on tubular epithelium and endothelium in both acute rejection and other causes of graft dysfunction, limiting its diagnostic value. Activated T cells expressing CD69-AIM (activation inducer molecule) and/or HLA-DR were frequently observed in acute rejection (24/35 (69%) and 25/35 (71%) respectively) but not in other causes of renal dysfunction. We then studied the prognostic usefulness of the immunohistochemical profile in acute rejection. Of 27 patients, 12 had a progressively decreased renal function or returned to dialysis within one year after transplantation while the other 15 had a stable graft function after at least 18 months of follow-up. In the group of bad prognosis (n = 12), corticosteroid-resistant rejection episodes were significantly more frequent (p < 0.01). In this group, nine patients had an overexpression of HLA-DR on tubular epithelium versus one patient in the group of stable graft function (chi 2c = 10.57, p < 0.002). Seven patients included in the group of bad prognosis showed tubular overexpression of both ICAM-1 and VCAM-1 versus one patient in the other group chi 2c = 6.23, p < 0.02). Moreover, patients of the first group had a significantly higher number of interstitial macrophages as compared with those who had stable graft function (chi 2c = 4.87, p < 0.01). Thus, our data show that the immunohistochemical profile studied is of little value in the diagnosis of renal allograft rejection. However, an intense tubular expression of HLA-DR and/or both ICAM-1 and VCAM-1, and a high number of interstitial macrophages are significantly related to unfavorable graft outcome.

Acute Disease↗
PubMed1995

Histologic observations of bone remodeling adjacent to endosteal dental implants.

To examine bone morphology associated with endosteal dental implants at various time intervals, we inserted 20 one-stage and 20 two-stage titanium blade implants and 20 one-stage and 20 two-stage titanium root-form implants into 30 dog mandibles. Sixteen implants in 6 control (c) dogs (in situ five months) did not receive bridgework. Sixty-four implants in 24 dogs supported bridges for six, 12, 18, or 24 months. The entire area of the mandible containing the implants was examined by routine light and Nomarski differential interference microscopy (NM) for bone morphology (including osteon orientation) at the implant surface and at regions away from the implant. Control root-form implants were apposed by woven bone, with homogenous compact bone in the cortical plate distant to the implant. After 6 mo of load, immature bone was predominant apposing the implant, but initial osteonal maturation was apparent. NM clearly demonstrated the interstitial and concentric lamellae of the bone. Surprisingly, compact bone formed internal to the cortical plate, an area where trabecular bone is expected. At later periods of load, more mature osteons were seen apposing the implants; however remodeling events were still apparent. These remodeling events extend further away from the implant than was expected if the events resulted only from surgical repair. Also, when the implant inclined so that half was totally in the cortical plate and half in the marrow (in trabecular patterns), osteonal bone appeared to remodel in both areas. Control blade implants and blades loaded for six months were apposed by immature osteons when the implant was placed into the cortical plate. A trabecular meshwork was inferior to the osteonal bone. At 12 mo of load, the bone internal to the cortical plate appeared similar to the lamina dura supporting teeth; however, no PDL existed; the lamina-dura-like pattern directly apposed the implant. Even after 24 mo of load, extensive bone remodeling was apparent adjacent to the implant, markedly different from the bone making up the existing cortical plate. From these data, remodeling activities to blade implants may involve the development of a lamina-dura-like bone morphology after longer periods of load. Osteonal bone was apparent, but only at regions where the implant was inserted into the cortical plate. Further, bone remodeling was apparent even after long periods of load.

Alveolar Process↗
PubMed1995

[Oxalosis].

Explore the source record for details and available documents.

Calcinosis↗
PubMed1994

CD8 lymphocytosis in primary cytomegalovirus (CMV) infection of allograft recipients: expansion of an uncommon CD8+ CD57- subset and its progressive replacement by CD8+ CD57+ T cells.

Allograft recipients undergoing cytomegalovirus infection present increased proportions of circulating CD8+ lymphocytes. A longitudinal study of 11 kidney and five liver allograft recipients with primary CMV infection but no other etiological factor of graft dysfunction revealed selective imbalances of peripheral blood CD8+ T cell subsets. Initially, CMV viraemia is associated with elevated CD8+bright T cell numbers and T cell activation. Activation markers fall to normal when viral cultures become negative (before the end of the first month). During the second to sixth month, most (12/16) patients keep up high CD8+ T cell counts (1050-2900 CD8+ cells/mm3), comprising an uncommon CD8+ T cell subset, as 45-73% of CD8+bright lymphocytes were CD3+ and TCR alpha beta+, but were not stained by anti-CD28, CD11b, CD16, CD56, and CD57 antibody. Unexpectedly, CD8+CD57+ T cells, a hallmark of CMV infection, do not appear until the second to sixth month of primary CMV infection, and their numbers increase progressively thereafter. They become the predominant CD8+ T cell subset after 6 months of infection and their persistence for several (up to 4) years is strongly correlated (r = 0.87) with expansion of CD8+ cells. By analysis with MoAbs, there was no bias towards the use of particular TCR-V beta gene families at any time of primary CMV infection. Persistence of CD8 lymphocytosis is thus directly related to the rate of expansion of an uncommon CD8+CD57- subset and its progressive replacement by CD8+CD57+ T cells that are chronically elicited by CMV.

Antigens, CD↗
PubMed1994

Successive emergence of two CD8 subsets in primary CMV infection of allograft recipients.

Allograft recipients with cytomegalovirus (CMV) infection develop increased proportions of circulating CD8+ lymphocytes. A longitudinal study of 11 kidney and 5 liver allograft recipients with primary CMV infection but no other aetiological factor to explain graft dysfunction revealed selective imbalances in peripheral blood CD8+ T cell subsets. Initially, CMV viraemia was associated with elevated CD8+bright T cell numbers and T cell activation. Activation markers fell to normal when viral cultures became negative (before the end of the 1st month). During the 2nd-6th months, most (12/16) patients continued to have high CD8+ T cell counts (1050-2900 CD8+ cells/mm3), comprising an uncommon CD8+ T cell subset, as 45-73% of CD8+bright lymphocytes were CD3+ and TCRalphabeta+ but were not stained by anti-CD28, CD11b, CD16, CD56 and CD57 antibody. Unexpectedly, CD8+ CD57+ T cells, a hallmark of CMV infection, did not appear until the 2nd-6th months of primary CMV infection, and their numbers increased progressively thereafter. They became the predominant CD8+ T cell subset after about 6 months of infection and their persistence for several (up to 4) years was strongly correlated (r = 0.87) with expansion of CD8+ cells. Persistence of CD8 lymphocytosis was, thus, directly related to the rate of expansion of an uncommon CD8+ CD57- subset and its progressive replacement by CD8+ CD57+ T cells that were chronically elicited by CMV.

Antigens, CD↗
PubMed1994

Detergent extraction and enzymatic analysis for fecal long-chain fatty acids, triglycerides, and cholesterol.

We report a procedure for determining fecal long-chain fatty acids (LCFA), triglycerides, and cholesterol after detergent extraction with 10 mL/L Triton X-100, 6 mL/L Brij 30, and 0.1 mol/L HCl in isotonic saline by enzymatic analysis of the extraction supernates. Mean recoveries of calibrators ranged from 105% to 117%. Assays of fecal extracts were linear with concentration from 0 to 1000 mumol/L for LCFA, from 10 to 90 mumol/L for triglycerides, and from 0 to 300 mumol/L for cholesterol. Within-run CVs were < 3% for medium and high concentrations, and 3%, 14%, and 28% for low concentrations of LCFA, cholesterol, and triglycerides, respectively. Correlation with gravimetric determination resulted in coefficients (r2) of 0.72 for total fat, 0.63 for neutral fat, and 0.66 for nonesterified fat. Assays of extracts and residues prepared for gravimetric determination indicated that approximately 90% of triglycerides, cholesterol, and LCFA were extracted by organic solvents and that the extracts contain a significant amount of other fats. The proposed method appears accurate, precise, specific, and suitable for routine analysis.

Cholesterol↗
PubMed1992

[Transplantation for primary hyperoxaluria. Role of oxalate crystal deposits in the occurrence of kidney failure].

We analyzed the records of 3 patients transplanted for end-stage renal failure due to primary hyperoxaluria and evaluated on repeat biopsies the role played by oxalate deposits in the constitution of renal failure after isolated kidney graft, or combined liver and kidney transplantation. Early failure of the renal graft is frequent and often interpreted as the consequence of recurrence because of the presence of oxalate deposits on the graft biopsy. In fact, the decrease in oxalate deposits observed in our 2 cases of combined liver and kidney transplantation despite the progressive renal failure, indicates that crystal deposition is not responsible for the renal lesions. However, we cannot exclude that the oxalate molecule toxicity plays a role in the constitution of the diffuse sclerosis which occurred in these two cases after a primary renal non function, aggravating a hemodynamic process by using cyclosporin. On the other hand, as observed in our isolated kidney graft, renal crystal deposition occurring before the onset of renal failure suggests the true mechanism explaining the slow recurrence of renal oxalosis.

Adult↗
PubMed1990

Acrolein depletes the neuropeptides CGRP and substance P in sensory nerves in rat respiratory tract.

The mammalian respiratory tract is densely innervated by autonomic and sensory nerves around airways and blood vessels. Subsets of these nerves contain a number of putative neurotransmitter peptides, such as substance P and calcitonin gene-related peptide (CGRP) in sensory nerves and vasoactive intestinal polypeptide (VIP), possibly serving autonomic functions. CGRP is also found in endocrine cells in rat airway epithelium. These peptides are all pharmacologically potent effectors of bronchial and vascular smooth muscle and bronchial secretion. Their functions in vivo are less well established. We have therefore examined the effects of inhaled acrolein, a sensory irritant, on three pulmonary neuropeptides: CGRP, substance P, and VIP. Groups of rats (n = 3 each) were exposed for 10 min to acrolein in air (Ct = 510, 1858, and 5693 mg.min/m3) or to air alone. Fifteen minutes later they were killed (pentabarbitone IP) and their respiratory tracts were dissected and fixed in 0.4% p-benzoquinone solution. Cryostat sections were stained by indirect immunofluorescence for a general nerve marker (PGP 9.5) and neuropeptides. The acrolein-treated animals had a dose-related decrease in tracheal substance P- and CGRP-immunoreactive nerve fibers compared with controls. No change was seen in total nerve fiber distribution and number (PGP 9.5) or VIP immunoreactivity, nor in CGRP-immunoreactive epithelial endocrine cells. It is concluded that the rat tracheal peptidergic nerves are a sensitive indicator of inhaled irritant substances. Their reduced immunoreactivity may be because of a release of sensory neuropeptides that could play a role in the physiological response to irritant or toxic compounds.

Acrolein↗
PubMed1989

Influence of diet on plasma steroids and sex hormone-binding globulin levels in adult men.

Several experimental studies have suggested that diet can alter the production and metabolism of steroids in men. The purpose of this study was to determine the levels of unconjugated steroids and steroid glucuronides as well as sex hormone-binding globulin (SHBG) among normal adult men who were either omnivorous or vegetarians. The participants were white volunteers ranging from 25-35 years of age and the blood samples were taken between 0900 h and 1000 h and between 1600 h and 1700 h for two consecutive days. No significant statistical change was found in plasma dehydroepiandrosterone, dehydroepiandrosterone sulfate, testosterone, dihydrotestosterone and estradiol levels. Vegetarian group showed a higher levels of sex hormone-binding globulin (SHBG) while the free androgen index (FAI; calculated by the ratio testosterone/SHBG) was lower in this group. Although the concentrations of androsterone glucuronide were higher in vegetarian group, the vegetarians had a 25-50% lower level of androstane-3 alpha, 17 beta-diol glucuronide and androstane-3 beta,17 beta-diol glucuronide. Our data further indicate that both, androstane-3 alpha,17 beta-diol glucuronide and androstane-3 beta,17 beta-diol glucuronide concentrations are significantly correlated with SHBG levels and with the FAI values. The increases in androstane-3 alpha,17 beta-diol glucuronide and androstane-3 beta,17 beta-diol glucuronide levels in the omnivorous group are probably a consequence of the elevation of the FAI. Our data suggest that in a vegetarian group, less testosterone is available for androgenic action.

Adult↗
PubMed1989

Indirect clinical evidence that 1 alpha OH vitamin D3 increases the intestinal absorption of aluminum.

In a previous study we showed that 1 alpha OH vitamin D3 [1 alpha (OH)3] given to 16 hemodialyzed patients taking Al(OH)3 at a constant dose increased their plasma concentrations of aluminum [Demontis et al. 1986]. In order to choose between 2 possible mechanisms explaining this increase (increased intestinal absorption or decreased tissue storage of aluminum), we gave, in the present study, 1 alpha (OH)3 the same dose (6 micrograms per week) for the same period (4 weeks) to 15 stable hemodialyzed patients after their Al(OH)3 had been discontinued for 6 weeks. Under Al(OH)3 treatment they had a mean plasma aluminum (2.33 +/- 2.36 mumol/l) which was not significantly different from that of the patients in our former study (1.23 +/- 0.25 mumol/l). After Al(OH)3 discontinuation, plasma aluminum (measured by inductively coupled plasma emission spectrometry) decreased significantly as early as the 2nd week of the control period (1.39 mumol/l). The decrease was maintained at a plateau throughout the 5 weeks of the control period (1.38 mumol/l), the 4 weeks of 1 alpha OH vitamin (vit) D3 administration (1.40 mumol/l) and the 8 weeks of the post 1 alpha (OH)3 period (1.22 mumol/l). Plasma calcium and phosphate concentrations increased significantly with 1 alpha (OH)3 and decreased thereafter whereas plasma PTH concentrations decreased during 1 alpha (OH)2 D3 and increased after its discontinuation suggesting biological activity of 1 alpha (OH)3. Since 1 alpha (OH)3 increases plasma aluminum in hemodialyzed patients only when they are simultaneously taking Al(OH)3, it is suggested that this increase is explained by an increase of intestinal absorption of aluminum and not by a tissue redistribution of aluminum.

Adolescent↗
PubMed1984

[Phospho-calcium metabolism and bone histomorphometry in chronic alcoholism. Apropos of 25 cases].

Twenty five subjects, chronic alcoholics for more than five years, without any past history or clinical signs of portal hypertension or oedemato-ictero-ascitic decompensation, were examined by laboratory tests reflecting phosphoro-calcium metabolism and by transiliac bone biopsy with histomorphometric examination of nondecalcified bone. The subjects were fairly homogeneous in terms of liver function and liver disease, when present, was only minimal. The phosphoro-calcium parameters were generally normal, but hypomagnesaemia was observed. On the other hand, the histomorphometric study often revealed marked alterations: hyperosteoidosis: raised index of osteoid thickness (IOT) in 15 of the 25 cases, increase in the relative osteoid volume (ROV) in 12 cases and increase in the osteoid area (OA) in 8 cases. The bony trabecular volume (BTV) was only mildly reduced (13 out of 24) and there was increased resorption, reflected by an increase in the area of resorption (AR) seen in 15 cases, associated with a moderate increase in the area of periosteocytic lacunae (APOL). The essential changes consist of hyperosteoidosis with morphological osteomalacia in 60% of cases and reduction of the trabecular volume in 54%. Comparison of the different parameters reveals the following histomorphometric profile: BTV; AR; ROV; OA; IOT; APOL. Thus, histological bone changes occur in chronic alcholics before the appearance of signs of liver failure. These quantitatively minor changes are suggestive deficiency type bone.

Adult↗