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Fabien Calvo

Publications and source records attributed to Fabien Calvo.

24 records · Page 2Linked to original sources
PubMed2003

Effect of a diabetic environment in utero on predisposition to type 2 diabetes.

BACKGROUND: Type 2 diabetes is affected by genetics and environmental factors. We aimed to assess the effect of an in-utero diabetic environment independently of the genetic background for type 2 diabetes. METHODS: We measured insulin sensitivity and insulin secretion in response to oral and intravenous glucose in 15 non-diabetic adult offspring of mothers with type 1 diabetes (exposed participants) and 16 offspring of type 1 diabetic fathers (controls). No participants had type 1 diabetes-associated autoantibodies. We also measured pancreatic polypeptide, a marker of parasympathetic drive to the pancreas. FINDINGS: There was no difference between the groups with respect to percent body fat and insulin sensitivity. Five of the 15 exposed participants, but none of the controls had impaired glucose tolerance (p=0.02). Early insulin secretion after an oral glucose tolerance test was lower in exposed participants than in controls: 8.6 IU/mmol (SD 5.4) in exposed participants with impaired glucose tolerance, 14.2 IU/mmol (6.5) in those with normal glucose tolerance and 17.7 IU/mmol (10.9) in controls (p=0.04). Mean insulin secretion rate during glucose infusion study was 4.7 pmol/kg per min (3.6) in people with impaired glucose tolerance, 5.5 pmol/kg per min (4.5) in exposed participants with normal glucose tolerance and 7.5 pmol/kg per min (6.1) in controls (p<0.0001). The area under the curve of pancreatic polypeptide 120 min after oral glucose ingestion was 1007 (429) in people with impaired glucose tolerance, 2829 (1701) in those with normal glucose tolerance, and 3224 (1352) in controls (p=0.04). INTERPRETATION: Exposure to a diabetic environment in utero is associated with increased occurrence of impaired glucose tolerance and a defective insulin secretory response in adult offspring, independent of genetic predisposition to type 2 diabetes. This insulin secretory defect could be related to low parasympathetic tone. Epidemiological studies are needed to confirm our observations before therapeutic strategies can be devised.

Adult↗
PubMed2003

Randomized trial and local biological effect of autologous platelets used as adjuvant therapy for chronic venous leg ulcers.

OBJECTIVES: Platelet products have been proposed as adjuvant therapy for wound healing. We undertook this study to determine the healing effect of topically applied frozen autologous platelets (FAP) on chronic venous ulcers, compared with effect of placebo, and whether use of topical FAP modifies local expression of vascular endothelial growth factor (VEGF), keratinocyte growth factor (KGF), interleukin 8 (IL-8), and tissue inhibitor of metalloproteinase-1 (TIMP-1) in wound fluid. METHODS: This randomized, placebo-controlled, double-blind trial was carried out in institutional practice, with ambulatory patients with proved chronic venous leg ulcers. In all patients, whole venous blood was drawn for preparation of FAP. FAP or normal saline solution was applied three times per week for up to 12 weeks, together with hydrocolloids and standardized compression bandages. Leg ulcer surface was assessed with numerical pictures. IL-8, VEGF, KGF, and TIMP-1 levels were determined (enzyme-linked immunosorbent assay) in wound fluid after each 4 weeks of treatment. RESULTS: Fifteen patients were randomized into two groups with comparable leg ulcer characteristics. Mean percent reduction in ulcer area was 26.2% in the FAP group versus 15.2% in the placebo group (P =.94). One ulcer in each group was completely healed at study end. Levels of TIMP-1 increased significantly during FAP treatment. IL-8 concentration was significantly lower in wound fluid of healing ulcers than in the fluid of nonhealing ulcers, in both FAP and placebo groups. Growth factor levels were not modified with FAP treatment. CONCLUSION: Topical autologous platelets have no significant adjuvant effect on healing of chronic venous leg ulcers and increased wound fluid TIMP-1 concentration. Ulcer healing is associated with a decrease in wound fluid IL-8.

Administration, Topical↗
PubMed2002

Prognostic value of quantitative Kaposi sarcoma--associated herpesvirus load in posttransplantation Kaposi sarcoma.

Organ transplant recipients have a higher risk of Kaposi sarcoma (KS). A quantitative real-time polymerase chain reaction assay was developed to evaluate KS-associated herpesvirus (KSHV) as a prognostic tool in transplant recipients with KS. Forty-three patients who developed KS after transplantation were included in a cross-sectional study to correlate virus load with transplantation or KS parameters. Seventeen patients (40%) had KSHV viremia (>100 copies/microg of DNA; median, 6067 copies/microg of DNA). Factors associated with these levels of viremia by univariate analysis were progression of KS (P=.00002), time from KS diagnosis (P=.0007), actual stage of KS (P=.006), initial stage of KS (P=.22), graft loss (P=.013), and time from transplantation (P=.0246). Disease progression remained associated with KSHV viremia in a multivariate analysis (P=.01). Thus, quantification of KSHV load in peripheral blood mononuclear cells could represent a useful tool for monitoring transplant recipients with KS.

Cohort Studies↗
PubMed2002

Potential mechanisms of resistance to cytarabine in AML patients.

To determine whether the human equilibrative nucleoside transporter 1 (hENT1), deoxycytidine kinase (dCK), cytoplasmic 5'-nucleotidase (5NT), cytidine deaminase (CDD), topoisomerase I (TOPO I) and topoisomerase II alpha (TOPO II) are involved in clinical resistance to cytarabine (ara-C), we analyzed the level of expression of these parameters by reverse transcriptase polymerase chain reaction (rt-PCR), at diagnosis in the blast cells of 77 acute myeloid leukemia (AML) patients treated with ara-C, including 31 for whom samples were collected at first relapse. By univariate and/or multivariate analyses, patients with expression of 5NT or hENT1 deficiency at diagnosis had significantly shorter disease-free survival (DFS) and overall survival (OS). These results suggest that expression of 5NT and reduced hENT1 in leukemic blasts at diagnosis are correlated with clinical outcome and may play a role in resistance mechanisms to ara-C in patients with AML.

5'-Nucleotidase↗
PubMed2002

In vivo mechanisms of resistance to cytarabine in acute myeloid leukaemia.

Factors that reduce the intracellular concentration of triphosphorylated cytarabine (ara-CTP), the active form of cytarabine (ara-C), may induce chemoresistance in acute myeloid leukaemia (AML) patients. These factors include reduced influx of ara-C by the hENT1 transporter, reduced phosphorylation by deoxycytidine kinase (dCK), and increased degradation by high Km cytoplasmic 5'-nucleotidase (5NT) and/or cytidine deaminase (CDD). Increased levels of DNA polymerase alpha (DNA POL) and reduced levels of topoisomerase I (TOPO I) and topoisomerase II (TOPO II) have also been detected in ara-C-resistant cell lines. To determine whether these factors are implicated in clinical ara-C resistance, we analysed the expression of these parameters at diagnosis, using reverse transcription polymerase chain reaction, in the blast cells of 123 AML patients treated with ara-C. At diagnosis, hENT1, dCK, CDD, 5NT, TOPO I, TOPO II, DNA POL and MDR1 were expressed in 83%, 22%, 7%, 37%, 59%, 37%, 39% and 16% of patients respectively. In univariate analysis, patients with expression of 5NT or DNA POL at diagnosis had significantly shorter disease-free survival (DFS). In multivariate analysis, DNA POL positivity and hENT1 deficiency were related to a shorter DFS. In univariate analysis, patients with 5NT-positive blasts had significantly shorter overall survival (OS). In multivariate analysis, shorter OS was related to DNA POL positivity. These results suggest that expression of DNA POL, 5NT and hENT1 at diagnosis may be resistance mechanisms to ara-C in AML patients.

5'-Nucleotidase↗