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1.
J Infect Dis ; 2024 Mar 01.
Article in English | MEDLINE | ID: mdl-38428995

ABSTRACT

BACKGROUND: Critical illness induces immune disorders associated with an increased risk of hospital-acquired pneumonia (HAP) and acute respiratory distress syndrome (ARDS). Torque Teno Virus (TTV), from the Anelloviridae family, are proposed as a biomarker to measure the level of immunosuppression. Our objective was to describe the kinetics of TTV DNA loads and their association with critical-illness related complications. METHODS: We performed a longitudinal study in 115 brain-injured patients from a prospective cohort, collected endotracheal and blood samples at three time points (T1, T2, T3) during the two weeks post-admission in intensive care unit, and measured viral DNA loads using the TTV R-gene® kit (Biomerieux) and a pan-Anelloviridae in house qRT-PCR. RESULTS: TTV DNA was detected in the blood of 69, 71, and 64% of brain-injured patients at T1, T2 and T3 respectively. Time-associated variations of TTV and Anellovirus (AV) DNA loads were observed. Using a linear mixed-effects model, we found that HAP and ARDS were associated with lower blood AV DNA loads. CONCLUSION: Our results show that HAP or ARDS in critically ill patients are associated to changes in AV DNA loads, and should be evaluated further as a biomarker of immune disorders leading to these complications.

3.
Neurochirurgie ; 66(4): 195-202, 2020 Aug.
Article in English | MEDLINE | ID: mdl-32645393

ABSTRACT

INTRODUCTION: The management of antithrombotic therapy (AT) after surgery for chronic subdural hematoma (cSDH) requires taking account of the balance of risk between hemorrhage recurrence (HR) and the prophylactic thromboembolic effect (TE). The goal of the present study was to evaluate the prevalence of vascular events (VE: TE and/or HR) in the first 3 postoperative months after cSDH evacuation in patients previously treated by AT. The impact of AT resumption was also evaluated. PATIENTS AND METHODS: This observational prospective multicenter collaborative study (14 French neurosurgery centers) included patients with cSDH treated by AT and operated on between May 2017 and March 2018. Data collection used an e-CRF, and was principally based on an admission questionnaire and outcome/progression at 3 months. RESULTS: In this cohort of 211 patients, VE occurred in 58 patients (27.5%): HR in 47 (22.3%), TE in 17 (8%), with mixed event in 6 cases (2%). Median overall time to onset of complications 26 days±31.5, and specifically 43.5 days±29.25 for HR. Non-resumption of AT significantly increased the relative risk of VE [OR: 4.14; 95% CI: 2.08 - 8.56; P <0.001] and especially of TE [OR: 7.5; 95% CI: 1.2 - 42; P<0.001]. The relative risk of HR was significantly increased when AT was resumed at less than 30 days (P=0.015). CONCLUSION: The occurrence of VE in patients operated on for cSDH and previously treated by AT was statistically significant (27.5%). HR was the most common event (22.3%), whereas TE accounted for only the 8%, although with shorter time to onset. In order to prevent TE risk, AT should be restarted after 30 days, as HR risk is greatly decreased beyond this time.


Subject(s)
Fibrinolytic Agents/therapeutic use , Hematoma, Subdural, Chronic/surgery , Aged , Aged, 80 and over , Drainage , Female , France , Hematoma, Subdural, Chronic/prevention & control , Humans , Longitudinal Studies , Male , Neurosurgical Procedures , Postoperative Complications/epidemiology , Prevalence , Prospective Studies , Recurrence , Risk Factors , Surveys and Questionnaires , Treatment Outcome
6.
J Fr Ophtalmol ; 38(10): 904-11, 2015 Dec.
Article in French | MEDLINE | ID: mdl-26542679

ABSTRACT

INTRODUCTION: Cross-linking (CXL) increases corneal biomechanical strength in progressive keratoconus. Since riboflavin cannot penetrate intact corneal epithelium, removal of epithelium is necessary for the classic CXL procedure (epi-off), but can cause severe postoperative pain. To avoid this problem, a method preserving the epithelium (epi-on) is used. In this study, we aimed to evaluate and compare postoperative pain after epi-off CXL and epi-on CXL. MATERIALS AND METHODS: We present a retrospective study assessing the level of pain postoperatively in 38 patients between the age of 12 and 53 years who underwent CXL procedures at the University Hospital of Clermont-Ferrand from July 2013 to May 2014. Epi-off consisted of manual corneal de-epithelialization and riboflavin instillation for 20minutes, followed by UVA exposure for 9minutes. The epi-on technique used an applicator on the eye, filled with riboflavin, and a generator delivered a continuous low-level current for 5minutes. The duration of light exposure was similar in both groups. Postoperative medications were the same for both techniques. Assessment of pain and analgesic intake were reported by the patient on paper questionnaires. Pain was evaluated from preoperatively up until the end of the month. Statistical analyses were performed in bilateral formulation to an alpha type I and error risk of 5%. RESULTS: Twenty-three epi-off patients and 15 epi-on patients. Twenty-nine men and 9 women (76.3%/23.7%). Mean age: 28 years. Reference base time was the return from the operating room. In the epi-off group, pain increased significantly until the morning of D2 and did not return to its intraoperative level until noon D2, 1.8±2.0 vs 2.5±2.5 (P=0.12). Pain remained stable until the morning of D4. From noon D4 until D30, it was significantly less than intraoperatively 1.8±2.0 vs 0.7±1.4 (P=0.01). In the epi-on group, pain was significantly higher than intraoperatively until noon of D1 2.5±2.2 vs 3.8±2.5 (P=0.01). From the evening of D1, it returned to its intraoperative level until the evening of D2 2.5±2.2 vs 2±1.7 (P=0.34). From the morning of D3 it was significantly less than intraoperatively 2.5±2.2 vs 0.8±0.9 (P=0.001). Considering all measurement times, there was no significant difference between the two groups (P=0.75), except from evening of D2 until evening of D3 in favor of iontophoresis: 1.9±2.3 vs 1.0±1.3 (P=0.038). DISCUSSION: Epi-on seems less painful in the short term (up to noon of D1 for epi-on vs morning of D2 for epi-off) and with a shorter duration than epi-off. This can be explained by the absence of corneal de-epithelialization. However, the reduction in pain is not significant at all postoperative times, and a risk of epithelial abrasion during placement and removal of the corneal applicator may exist. CONCLUSION: Iontophoresis maintains the corneal epithelium, decreases pain and improves patient comfort. A new study involving more patients and strict monitoring of medication intake would strengthen the validity of these results.


Subject(s)
Cross-Linking Reagents/therapeutic use , Iontophoresis , Keratoconus/drug therapy , Pain, Postoperative/etiology , Riboflavin/therapeutic use , Adult , Analgesics/therapeutic use , Collagen , Cross-Linking Reagents/administration & dosage , Epithelium, Corneal/surgery , Female , Humans , Instillation, Drug , Male , Pain, Postoperative/drug therapy , Pain, Postoperative/prevention & control , Retrospective Studies , Riboflavin/administration & dosage , Surveys and Questionnaires , Time Factors
7.
Virologie (Montrouge) ; 11(6): 409-421, 2007 Dec 01.
Article in French | MEDLINE | ID: mdl-36131464

ABSTRACT

Beet necrotic yellow vein virus is responsible for sugar beet rhizomania. Root proliferation is characteristic of the viral infection and lead to sugar losses. Pathogenicity is particularly linked to the expression of RNA-3-encoded p25. The extensive use of viral tolerant crops allows maintenance of sugar yields but also permits viruliferous vector to be maintained and therefore the appearance of resistance breaking isolates. The resistance breaking isolates present some amino acid variations within the p25 protein sequence, a key determinant in BNYVV pathogenicity. Here, we will review the molecular biology of BNYVV, of its vector and the antiviral strategies that may be used against rhizomania.

8.
Eur J Pediatr ; 159(10): 778-82, 2000 Oct.
Article in English | MEDLINE | ID: mdl-11039136

ABSTRACT

UNLABELLED: The effectiveness and tolerance of antiretroviral therapy with a combination of three reverse transcriptase inhibitors starting at the time of diagnosis (before 2 months of age) was evaluated in four infants with vertically acquired HIV-1 infection. Plasma HIV-1 RNA levels ranged from 230,000 to 1,000,000 copies/ml before onset of triple therapy and fell below 50 copies/ml at 12 to 33 weeks of life in three of the infants. These three children, currently aged 158, 105 and 72 weeks, are asymptomatic, have normal lymphocyte subsets and no hypergammaglobulinaemia. Two children experienced a profound reduction in the amount of proviral DNA detected in blood and have become HIV-1 seronegative, although one of them has had HIV-1 RNA detectable on a single occasion at 114 weeks of life (303 copies/ml). Transient interruption of therapy resulted in a rapid but reversible increase in HIV-1 RNA levels in the third child and was associated with the production of HIV-specific antibodies. The fourth child whose parents were not compliant to treatment and follow-up had a poor virological response. CONCLUSION: Early treatment of vertically acquired human immunodeficiency virus type 1 infection with three reverse transcriptase inhibitors is well tolerated and can result in such suppression of viral replication that specific antibodies are not produced, that proviral DNA falls to the lower limit of quantitation in blood and that all clinical and immunological manifestations of infection are avoided. Parental adhesion is crucial to the effectiveness of therapy.


Subject(s)
Anti-HIV Agents/therapeutic use , HIV Infections/drug therapy , HIV-1/isolation & purification , Infant, Newborn, Diseases/drug therapy , Infectious Disease Transmission, Vertical , Reverse Transcriptase Inhibitors/therapeutic use , Antibodies, Viral/blood , Antibodies, Viral/drug effects , DNA, Viral/blood , DNA, Viral/drug effects , Drug Therapy, Combination , Female , HIV Infections/diagnosis , HIV Infections/transmission , Humans , Infant , Infant, Newborn , Infant, Newborn, Diseases/diagnosis , Treatment Outcome
9.
Biochem Cell Biol ; 77(4): 265-75, 1999.
Article in English | MEDLINE | ID: mdl-10546890

ABSTRACT

The role of mechanical and chemical signalling pathways in the organization and function of chromatin is the subject of this review. The mechanical signalling pathway consists of the tissue matrix system that links together the three-dimensional skeletal networks, the extracellular matrix, cytoskeleton, and nuclear matrix. Intermediate filament proteins are associated with nuclear DNA, suggesting that intermediate filaments may have a role in the organization of chromatin. In human hormone-dependent breast cancer cells, the interaction between cytokeratins and chromatin is regulated by estrogens. Transcription factors, histone acetyltransferases, and histone deacetylases, which are associated with the nuclear matrix, are components of the mechanical signalling pathway. Recently, we reported that nuclear matrix-bound human and chicken histone deacetylase 1 is associated with nuclear DNA in situ, suggesting that histone deacetylase has a role in the organization of nuclear DNA. Chemical signalling pathways such as the Ras/mitogen-activated protein kinase (Ras/MAPK) pathway stimulate the activity of kinases that modify transcription factors, nonhistone chromosomal proteins, and histones. The levels of phosphorylated histones are increased in mouse fibroblasts transformed with oncogenes, the products of which stimulate the Ras/MAPK pathway. Histone phosphorylation may lead to decondensation of chromatin, resulting in aberrant gene expression.


Subject(s)
Chromatin/ultrastructure , Neoplasms/genetics , Signal Transduction , Amino Acid Sequence , Animals , Chromatin/physiology , Histone Deacetylases/metabolism , Humans , Models, Chemical , Molecular Sequence Data , Oncogenes , Protein Conformation , Transcription, Genetic
10.
Diabetes Metab ; 24(1): 55-61, 1998 Feb.
Article in English | MEDLINE | ID: mdl-9534010

ABSTRACT

To determine the effect of benfluorex on glycaemic control in obese insulin-requiring Type 2 diabetes, 76 patients (aged 53.8 +/- 12.8 years) receiving insulin (> or = 0.5 IU/kg) and an appropriate low-calorie diet were evaluated after a 1-month run-in followed by a 3-month double-blind treatment period (3 tablets daily) with benfluorex (B; n = 37) vs placebo (P; n = 39). At inclusion, the B and P groups respectively did not differ in body weight (80.9 +/- 10.3 vs 77.2 +/- 9.1 kg), body mass index (BMI) (30.1 +/- 4.6 vs 29.0 +/- 2.3 kg/m2) or fasting blood glucose (11.22 +/- 4.33 vs 10.35 +/- 4.42 mmol/l). However, daily insulin dose and HbA1c levels were higher in the B group (59.9 +/- 18.6 vs 50.4 +/- 12.8 IU, p = 0.012; and 7.72 +/- 1.60 vs 6.96 +/- 1.27%, p = 0.025, respectively). After 3 months of treatment, the decrease in daily insulin dose was greater in the B group (8.7 +/- 10.1 vs 2.7 +/- 8.1 IU; p = 0.032), with a decrease in HbA1c (-0.73 +/- 1.74%, p = 0.026), vs no change in the P group (+0.01 +/- 1.65%, NS) and a tendency towards a greater decrease in fasting blood glucose (-1.43 +/- 5.41 vs +0.42 +/- 3.78 mmol/l respectively). Body weight and BMI were also lower in the B group (1.77 ñ 2.27 vs 0.21 ñ 2.68 kg, p = 0.013; and 0.64 +/- 0.84 vs 0.07 +/- 1.07 kg/m2, p = 0.019, respectively) in parallel with the decrease in insulin dose. Triglycerides decreased in the B group vs an increase in the P group (-0.54 +/- 2.04 vs +0.21 +/- 0.70 mmol/l p = 0.06). Total cholesterol decreased within the B group (-0.47 +/- 1.01 mmol/l; p = 0.013) and vs the P group (intergroup p = 0.006). Adverse events were reported in 11 patients in the B group vs 5 in the P group (NS), causing dropout in only one case (intercurrent illness, P group). Addition of benfluorex in obese insulin-requiring Type 2 diabetes thus enhances glycaemic control and lowers both daily insulin requirement and body weight. Benfluorex + insulin is a valid alternative for obese patients who remain poorly controlled despite insulin or who require high doses of insulin.


Subject(s)
Blood Glucose/metabolism , Diabetes Mellitus, Type 2/drug therapy , Diabetes Mellitus/drug therapy , Fenfluramine/analogs & derivatives , Hypolipidemic Agents/therapeutic use , Insulin/therapeutic use , Obesity , Adolescent , Adult , Aged , Body Weight/drug effects , C-Peptide/metabolism , Dose-Response Relationship, Drug , Female , Fenfluramine/therapeutic use , Humans , Insulin Resistance , Male , Middle Aged , Monitoring, Physiologic , Postprandial Period
11.
Psychiatr Enfant ; 38(2): 655-91, 1995.
Article in French | MEDLINE | ID: mdl-8657805

ABSTRACT

Clinicians and parents are familiar with the fact that adolescents have a special vocabulary, but very few studies have examined this. Linguists describe it as deeply metaphoric, creative and lively, thus showing that young people have a deep knowledge of language and truly experience pleasure using words. This contrasts with teachers' complaints about the little taste adolescents show for oral school activities and how poorly they express themselves. Some of them link this to the use of this polysemic and all purpose vocabulary. The context of locution is probably the explanation for these diverging opinions. Using this hypothesis, we have realised a quantitative study of the lexical variations depending on the person the adolescent is talking to in two groups (20 and 19 subjects), from very different social and educational backgrounds. Each teen-ager had to perform the same linguistic task: the description of a photograph on two occasions, once with an adult examiner and once with a friend. We studied the lexical differences between the two narratives. When adolescents are together they use their particular vocabulary four times more than when with an adult. But this qualitative difference is not a quantitative one, such as the length of the narrative or the number and repetition of whole words, and isn't correlated with the lexical stock. The use of this vocabulary runs across gender and social class categories. It can equally be found in high performance and upper class students as well as in underprivileged youngsters of technical schooling. It is the only variable that does not change between the two high schools. Thus this special vocabulary would not be connected to the subject's lexical competence, nor to gender or social background. It is the psychological function of this language that seems to be prominent.


Subject(s)
Adolescent Behavior , Communication , Interpersonal Relations , Vocabulary , Adolescent , Adult , Female , Humans , Male , Paris , Peer Group , Psycholinguistics , Social Class , Socioeconomic Factors
13.
Biochemistry ; 32(3): 784-90, 1993 Jan 26.
Article in English | MEDLINE | ID: mdl-8422382

ABSTRACT

Aminopeptidases catalyze the hydrolysis of amino acid residues from the amino terminus of peptide substrates. Their activity has been implicated in myriad fundamental biochemical and physiological processes, and alterations in aminopeptidase activity have been correlated with a variety of pathologies. Nevertheless, information about this group of proteases is less well developed. Bovine lens leucine aminopeptidase (blLAP) can be considered prototypical of many enzymes in this family of peptidases. It shows common features of (1) requiring divalent metal ions for activity, (2) having a relatively large size, and (3) having slow, relatively tight binding of bestatin, a transition-state analog of the substrate PheLeu. Bovine lens LAP is the only bestatin-inhibitable aminopeptidase for which structural and mechanistic data are available. However, full exploitation of these data required knowledge of the number of inhibitor molecules bound per subunit. Independent direct binding experiments and kinetic determinations indicate that one bestatin is bound per subunit in blLAP. Ki and Ki* for formation of the initial and final complexes are approximately 1.1 x 10(-7) and 1.3 x 10(-9) M, respectively. The mode of binding is slow and competitive. The t1/2 for formation and deformation of the final enzyme-inhibitor complex is approximately 30 and 22 min, respectively, with 10(-8) M bestatin. To perform these measures, a new assay using physiological peptides (LeuGlyGly) as substrate was adapted. Taken together with prior NMR, photoaffinity labeling, and crystallographic data, these binding data allow us to propose a mechanism of the blLAP-catalyzed hydrolysis of peptides.


Subject(s)
Lens, Crystalline/enzymology , Leucine/analogs & derivatives , Leucyl Aminopeptidase/antagonists & inhibitors , Aminopeptidases/antagonists & inhibitors , Aminopeptidases/metabolism , Animals , Binding Sites , Binding, Competitive , Cattle , Kinetics , Leucine/metabolism , Leucine/pharmacology , Leucyl Aminopeptidase/metabolism , Models, Chemical , Peptides/metabolism , Substrate Specificity , Time Factors
15.
Arch Mal Coeur Vaiss ; 85 Spec No 2: 185-8, 1992 Sep.
Article in French | MEDLINE | ID: mdl-1337427

ABSTRACT

Coronary artery disease in cardiac transplant recipients is the main cause of mortality after the first postoperative year. This atheroma has unique anatomical features with widespread infiltration of the intima by inflammatory cells. The different physiopathological hypotheses are analysed. Immunological processes are probably responsible, suggesting chronic rejection. The cytomegalovirus could be an inductive mechanism. The classical vascular risk factors probably play a role but their action is not as clear as that of immunological and viral factors. Hyperlipidaemia is a causative mechanism and the predisposing role of steroid therapy is also recognised. From the practical point of view, correction of the classical risk factors is the only available therapeutic possibility at present.


Subject(s)
Coronary Disease/etiology , Heart Transplantation/adverse effects , Animals , Coronary Disease/physiopathology , Coronary Disease/prevention & control , Cytomegalovirus Infections/complications , Graft Rejection , Heart Transplantation/mortality , Humans , Immunosuppression Therapy/adverse effects , Male , Rabbits , Risk Factors
16.
Biochemistry ; 31(16): 4141-50, 1992 Apr 28.
Article in English | MEDLINE | ID: mdl-1567860

ABSTRACT

Aminopeptidases catalyze the hydrolysis of amino acid residues from the amino terminus of peptide substrates. They are found in most cells and tissues, and their activity has been implicated in myriad fundamental biochemical and physiological processes. Nevertheless, little is known about the structure of the aminopeptidase active sites. Beef lens leucine aminopeptidase (blLAP) can be considered prototypical of many enzymes in this family of peptidases. Bestatin, [(2S,3R)-(3-amino-2-hydroxy-4-phenyl-butanoyl)-L-leucine] is a nonhydrolyzable substrate analogue of a peptide, PheLeu, which is rapidly cleaved by blLAP. Bestatin incorporates elements of the putative tetrahedral intermediate, and this results in a greater than 10(5)-fold enhancement of binding relative to analogous peptides. Bestatin is the most tightly bound inhibitor of many aminopeptidases. Bestatin was successively converted to nitrobestatin, p-aminobestatin, [3H]-p-aminobestatin, and finally [3H]-p-azidobestatin (pAB). Like bestatin, pAB is a slow binding inhibitor of LAP (Ki*, the dissociation constant for the final complex, = approximately 4 x 10(-9); Ki, the dissociation constant for the initial collision complex, = approximately 10(-8). The t1/2 for binding of 2 x 10(-8) M and 8 x 10(-8) M bestatin are approximately 60 min and approximately 38 min, respectively. pAB, nitrobestatin, bestatin, and physiological peptides appear to bind in the same site, the first three with similar avidity. In the dark, pAB and bestatin protect low concentrations of the enzyme against inactivation upon extensive dialysis. The t1/2 for photoactivation of pAB is approximately 3 s. Irradiation of blLAP for such short periods of time resulted in insignificant change in activity. blLAP which was placed in 254-nm light in the presence of pAB was inactivated significantly. Treatment of photolabeled blLAP with trypsin produces only two peptides. Autoradiography and scintillation counting indicate that the active site is in the peptide which includes residues 138-487. Treatment of the same blLAP with hydroxylamine produces two different peptides, with the active site in the peptide 323-487. This indicates that the active site is in the carboxyl-terminal one-third of the protomer. It is likely that this photoaffinity label will be useful in identifying active sites in other aminopeptidases as well.


Subject(s)
Affinity Labels , Azides/metabolism , Leucine/analogs & derivatives , Leucyl Aminopeptidase/metabolism , Amino Acid Sequence , Azides/chemical synthesis , Azides/pharmacology , Binding Sites , Binding, Competitive , Hydroxylamine , Hydroxylamines/metabolism , Kinetics , Leucine/chemical synthesis , Leucine/metabolism , Leucine/pharmacology , Leucyl Aminopeptidase/antagonists & inhibitors , Molecular Sequence Data , Oligopeptides/metabolism , Photochemistry , Spectrophotometry , Trypsin/metabolism
18.
Exp Eye Res ; 46(4): 579-90, 1988 Apr.
Article in English | MEDLINE | ID: mdl-3289956

ABSTRACT

Beef lens cells in culture are readily obtained and provide many opportunities to study phenomena related to cell differentiation and maturation, environmental stress, disease, and perhaps mechanisms of transformation. Although altered rates of proteolysis are known to accompany these phenomena, the proteolytic activities available in cultured beef lens epithelial cells have not been documented. In this work are documented the specific activities, based on protein and DNA content, of neutral exo- and endopeptidase, cathepsins B- and D-like enzymes and acid phosphatase in lens epithelial cortical and core tissue and in cultured epithelial cells at passages 1-43. Maximal activity of each protease occurs almost routinely at passage 5 or 9, reaching values of approx. 1400-, 0.77-, 4520-nmol min-1 per mg protein for neutral exopeptidase (passage 5), neutral endopeptidase (passage 5) and cathepsin B (passage 5) respectively, and 7.1 micrograms trichloroacetic acid soluble peptide min-1 per mg protein for cathepsin D (passage 15). On a microgram-1 DNA basis, the maximal specific activities for the same enzymes were 48 (passage 5), 0.03 (passage 5), 283 (passage 9), and 0.5 (passage 9) respectively. In subsequent passages, the specific activities declined to values which were similar to or lower than the specific activities observed for these proteases in lens epithelial tissue.


Subject(s)
Lens, Crystalline/enzymology , Peptide Hydrolases/metabolism , Acid Phosphatase/metabolism , Animals , Cathepsin B/metabolism , Cathepsin D/metabolism , Cattle , Cells, Cultured , Crystallins/analysis , DNA/analysis , Endopeptidases/metabolism , Epithelium/enzymology , Exopeptidases , Neprilysin , Time Factors
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