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Biomedical subjects

C Fermon

Publications and source records attributed to C Fermon.

At least 19 recordsLinked to original sources
PubMed2006

Continuous intraperitoneal insulin infusion does not increase the risk of organ-specific autoimmune disease in type 1 diabetic patients: results of a multicentric, comparative study.

AIM: The purpose of this national multicenter prospective study by the French EVADIAC group was to investigate the possibility that continuous intraperitoneal insulin infusion using an implanted pump (CIpii) increases the risk of autoimmune disease in type 1 diabetic patients as it increased anti-insulin immunogenicity. METHODS: Prevalence of clinical (Hashimoto's disease, hyperthyroidism, gastric atrophic disease and vitiligo) and subclinical (presence of anti-thyroperoxidase antibodies, anti-intrinsic factor antibodies, abnormal TSH levels) autoimmune diseases was estimated by comparing two groups of patients already treated by either CIpii (n=154) or external pump (CSII) (n=121) for an average of 6 years. Incidence of autoimmune disease was determined by comparing the same measurements one year after inclusion. RESULTS: No significant difference was observed for the total prevalence of clinical and subclinical auto-immune thyroid and gastric di-seases (35.6% and 3.2% respectively in the CIpii group versus 40.4% and 2.6% in the CSII group). No significant difference for the incidence of clinical and subclinical auto-immune diseases was observed: 7.2% and 0% in CIpii and 7.3% and 1.7% in CSII. CONCLUSION: As previously shown AIA (anti-insulin antibodies) levels were higher in CIpii than in CSII (32.9% vs 20.2%, P<0.0001) but no correlation was observed with either clinical or subclinical autoimmune disease. This large-scale study eliminates the possibility that CIpii increases the risk of autoimmune disease.

Adult↗
PubMed2005

Advantages to using capillary blood beta-hydroxybutyrate determination for the detection and treatment of diabetic ketosis.

Ketone body determination is indicated in all diabetic patients when the risk of ketotic decompensation exists. New methods of screening for ketosis, in particular capillary blood ketone body determination, provide analytical, technical and clinical advantages compared to the conventional ketonuria. It is proposed that a diabetic patient with hyperglycaemia (capillary blood glucose > 2.50 g.l(-1)) and capillary blood ketone bodies exceeding 0.5 mmol.l(-1) requires therapeutic management. For values greater than 3 mmol.l(-1) or in case of more serious clinical symptoms, hospitalisation is indicated, considering the high probability of ketoacidotic decompensation. The advantages of capillary blood ketone body determination including easy use, and rapid and objective results may improve management of the diabetic patient, especially in emergency situations. However, prescription by a physician of capillary blood ketone body determination should be offered to targeted populations that have a high risk of ketoacidotic decompensation, after providing education to patients that is above all aimed at preventing this metabolic complication. In this context of determining ketone bodies in capillary blood, the term "capillary blood ketone bodies" is therefore preferable to the term "capillary blood beta-hydroxybutyrate determination". Indeed, it appears more appropriate, simple, descriptive and significant both for health-care staff and for patients.

3-Hydroxybutyric Acid↗
PubMed2005

Subcutaneous insulin resistance successfully circumvented on long term by peritoneal insulin delivery from an implantable pump in four diabetic patients.

UNLABELLED: Extreme subcutaneous insulin resistance is a rare syndrome characterized by a severe resistance to subcutaneous (S/C) insulin together with persistence of normal or near normal intravenous (IV) insulin sensitivity. Its pathophysiology is unknown, although increased insulin degrading activity has been reported in the S/C adipose tissue fraction in some cases. Until now, proposed treatments have been disappointing. We report 4 cases who were successfully treated by intraperitoneal (IP) route. METHODS: The diagnosis of subcutaneous insulin resistance was based upon following combined conditions: resistance to hypoglycaemic action of subcutaneous insulin but normal or near normal sensitivity to IV or IP insulin. RESULTS: 4 patients among those followed by EVADIAC group met these criteria: 3 with type 1 diabetes (C peptide=0), the last one with unexplained non insulin-deficient diabetes (no anti-GAD antibodies, C peptide=5 ng/ml). All of them had been treated with subcutaneous insulin therapy without success despite huge doses (up to 4000 IU/day in two patients). The 3 type 1 diabetic patients presented with a history of repeated ketoacidosis episodes. A treatment of insulin mixed with aprotinin had been proposed to 2 patients without success. The IV insulin sensitivity was proved to be normal in two patients by euglycaemic clamp data. A skin biopsy was performed in 1 patient. An accumulation of insulin in the derma was revealed with no increase of degradation products of insulin. In these 4 patients, a dramatic improvement of diabetes control was obtained by IP insulin delivery from an implantable pump (HbA1c decrease by at least 3%). CONCLUSION: Although pathophysiology of the subcutaneous insulin resistance syndrome remains unexplained, our data show that intra-peritoneal insulin therapy from an implantable pump allows diabetes control in patients affected by this uncommon but severely disabling condition.

Adult↗
PubMed2003

Extreme subcutaneous insulin resistance: a misunderstood syndrome.

Extreme subcutaneous insulin resistance (SIR) is a rare syndrome characterized by severe resistance to subcutaneous insulin with normal intravenous insulin sensitivity. Its pathophysiology is unknown, though an increased insulin degrading activity has been suggested. We report the case of a 35 year-old female patient with type I diabetes since the age of 3. Despite five shots of insulin/day, the patient progressively developed permanent ketosis related to severe acquired SIR with insulin doses as high as 500 U/day. Subcutaneous infusion of insulin and lispro insulin through an external pump did not improve resistance: HbA(1c) levels remained between 14 and 18% (N<6.5%). After numerous ketoacidotic episodes, continuous ambulatory intravenous insulin infusion was attempted through a central port due to a lack of peripheral venous access. HbAlc improved (8.5%) and daily insulin needs decreased to below 40U. However, the treatment had to be discontinued because of thrombosis and infection at different times. Intraperitoneal insulin infusion with an external pump was then proposed. HbAlc improved to 8% during 18 months but several episodes of catheter infection and encapsulation led to its removal. An intraperitoneal pump was surgically implanted, leading to the stabilization of HbA(1c) to around 8%. An insulin degradation assay did not demonstrate any excess of insulin degrading activity in the patient's or controls' subcutaneous tissue; nevertheless, excessive amounts of insulin were found in the patient's derm compared to controls. This case report of acquired SIR raises the question of its treatment and mechanisms. Regarding treatment, intraperitoneal delivery of insulin appears to be the best solution, but the mechanisms underlying SIR still remain unclear.

Adult↗
PubMed2003

[Today data management in self-monitoring of blood glucose for diabetic patients].

Improving diabetes treatment needs intensive glucose monitoring which is restricting for patients and time-consuming for physicians. Up-to-date tools of data management were developed, following progress in computing technology and home computing. Glucometers with memory and softwares are able to improve data management of self blood glucose monitoring, personalized interactivity with physician. They are very important to develop telemedecine systems in diabetes care. These systems are designed to complement the daily care and intensive management of diabetics through telemonitoring and telecare services.

Blood Glucose↗
PubMed2002

Individual domain wall resistance in submicron ferromagnetic structures.

The resistance generated by individual domain walls is measured in a FePd nanostructure. Combining transport and magnetic imaging measurements, the intrinsic domain wall resistance is quantified. It is found positive and of a magnitude consistent with that predicted by models based on spin scattering effects within the walls. This magnetoresistance at a nanometer scale allows a direct counting of the number of walls inside the nanostructure. The effect is then used to measure changes in the magnetic configuration of submicron stripes under application of a magnetic field.

Journal Article↗
PubMed2002

Spin wave wells in nonellipsoidal micrometer size magnetic elements.

We show experimentally and by model calculations that in finite, nonellipsoidal, micrometer size magnetic thin film elements the dynamic magnetic eigenexcitations (spin waves) may exhibit strong spatial localization. This localization is due to the formation of a potential well for spin waves in the highly inhomogeneous internal magnetic field within the element.

Journal Article↗
PubMed2001

Factor VII, tissue factor pathway inhibitor, and monocyte tissue factor in diabetes mellitus: influence of type of diabetes, obesity index, and age.

Changes of the tissue factor (TF) pathway of blood coagulation have been described in diabetes and could be involved in its vascular complications. In order to evaluate the influence of the type of diabetes and of the obesity index and age on these changes, factor VII coagulant activity, factor VII antigen, activated factor VII, monocyte TF expression, and plasma Tissue Factor Pathway Inhibitor (TFPI) were examined in 18 Type 1 and 16 Type 2 diabetic patients compared to non-diabetic control subjects matched for age, sex, and obesity index (Types 1 and 2 controls, respectively). Multicomplicated patients were excluded. FVIIc, FVIIAg, and FVIIa were higher in Type 2 diabetic patients and controls than in Type 1 diabetic patients and controls (P< .03). However, FVIIc and FVIIAg were lower in diabetic patients than in their matched controls (P< .03). Monocyte expression of TF was not different between Types 1 and 2 diabetic patients and their matched controls except for LPS-stimulated monocyte TF activity which was lower in Type 2 diabetic patients than in Type 2 controls (P< .05). Plasma TFPI was slightly but significantly higher in Type 1 diabetic patients than in Type 1 controls (P= .01) and was correlated to glycemia. However, both in Type 2 diabetic patients and controls, TFPI was higher than in Type 1 controls and was correlated with BMI (P< .0003). These results indicate that in not multicomplicated patients, the increase of FVII and TFPI was highly dependent on obesity index and age rather than on diabetes by itself.

Adult↗
PubMed2000

Anisotropy of domain wall resistance

The resistive effect of domain walls in FePd films with perpendicular anisotropy was studied experimentally as a function of field and temperature. The films were grown directly on MgO substrates, which induces an unusual virgin magnetic configuration composed of 60 nm wide parallel stripe domains. This allowed us to carry out the first measurements of the anisotropy of domain wall resistivity in the two configurations of current perpendicular and parallel to the walls. At 18 K, we find 8.2% and 1.3% for the domain wall magnetoresistance normalized to the wall width (8 nm) in these two respective configurations. These values are consistent with the predictions of Levy and Zhang.

Journal Article↗
PubMed1998

Efficient Time Propagation Technique for MAS NMR Simulation: Application to Quadrupolar Nuclei.

The quantum mechanical Floquet theory is investigated in order to derive an efficient way of performing numerical calculations of the dynamics of nuclear spin systems in MAS NMR experiments. Here, we take advantage of time domain integration of the quantum evolution over one period as proposed by Eden et al. (1). But a full investigation of the propagator U(t, t0), and especially its dependence with respect to t and t0 within a formalized approach, leads to further simplifications and to a substantial reduction in computation time when performing powder averaging for any complex sequence. Such an approximation is suitable for quadrupolar nuclei (I > 1/2) and can be applied to the simulation of the RIACT (rotational induced adiabatic coherence transfer) phenomenon that occurs under special experimental conditions in spin locking experiments (2-4). The present method is also compared to the usual infinite dimensional Floquet space approach (5, 6), which is shown to be rather inefficient. As far as we know, it has never been reported for quadrupolar nuclei with I >/= 3/2 in spin locking experiments. The method can also be easily extended to other areas of spectroscopy. Copyright 1998 Academic Press.

Journal Article↗
PubMed1998

Guidelines for the treatment of acidaemia with THAM.

THAM (trometamol; tris-hydroxymethyl aminomethane) is a biologically inert amino alcohol of low toxicity, which buffers carbon dioxide and acids in vitro and in vivo. At 37 degrees C, the pK (the pH at which the weak conjugate acid or base in the solution is 50% ionised) of THAM is 7.8, making it a more effective buffer than bicarbonate in the physiological range of blood pH. THAM is a proton acceptor with a stoichiometric equivalence of titrating 1 proton per molecule. In vivo, THAM supplements the buffering capacity of the blood bicarbonate system, accepting a proton, generating bicarbonate and decreasing the partial pressure of carbon dioxide in arterial blood (paCO2). It rapidly distributes through the extracellular space and slowly penetrates the intracellular space, except for erythrocytes and hepatocytes, and it is excreted by the kidney in its protonated form at a rate that slightly exceeds creatinine clearance. Unlike bicarbonate, which requires an open system for carbon dioxide elimination in order to exert its buffering effect, THAM is effective in a closed or semiclosed system, and maintains its buffering power in the presence of hypothermia. THAM rapidly restores pH and acid-base regulation in acidaemia caused by carbon dioxide retention or metabolic acid accumulation, which have the potential to impair organ function. Tissue irritation and venous thrombosis at the site of administration occurs with THAM base (pH 10.4) administered through a peripheral or umbilical vein: THAM acetate 0.3 mol/L (pH 8.6) is well tolerated, does not cause tissue or venous irritation and is the only formulation available in the US. In large doses, THAM may induce respiratory depression and hypoglycaemia, which will require ventilatory assistance and glucose administration. The initial loading dose of THAM acetate 0.3 mol/L in the treatment of acidaemia may be estimated as follows: THAM (ml of 0.3 mol/L solution) = lean body-weight (kg) x base deficit (mmol/L). The maximum daily dose is 15 mmol/kg for an adult (3.5L of a 0.3 mol/L solution in a 70kg patient). When disturbances result in severe hypercapnic or metabolic acidaemia, which overwhelms the capacity of normal pH homeostatic mechanisms (pH < or = 7.20), the use of THAM within a 'therapeutic window' is an effective therapy. It may restore the pH of the internal milieu, thus permitting the homeostatic mechanisms of acid-base regulation to assume their normal function. In the treatment of respiratory failure, THAM has been used in conjunction with hypothermia and controlled hypercapnia. Other indications are diabetic or renal acidosis, salicylate or barbiturate intoxication, and increased intracranial pressure associated with cerebral trauma. THAM is also used in cardioplegic solutions, during liver transplantation and for chemolysis of renal calculi. THAM administration must follow established guidelines, along with concurrent monitoring of acid-base status (blood gas analysis), ventilation, and plasma electrolytes and glucose.

Acidosis↗
PubMed1985

Medical treatment of hyperprolactinemia.

The current treatment of choice for primary hyperprolactinemia is medical. This is true not only for idiopathic forms, but also for micro- and macroprolactinomas, which are the most frequent causes of this pathology. Although questioned by some authors, the slow evolution of the illness, the rarity of transformation of a microadenoma into a macroadenoma, and the possibility of spontaneous cure cause most authors to favor medical treatment, with which they observe both normalization of gonadal function and tumor regression. By retrospective analysis of 95 hyperprolactinemic patients (72 women and 23 men including 26 cases of suspected microadenoma and 44 macroadenomas) treated with 3 dopamine agonists (bromocriptine, metergoline and CU 32085) between 1975 and 1983, and with the help of large series published in the literature, we have tried to review the present knowledge of this subject. After a quick review of different medications, we will consider their prolactin-suppressing effects, their influences upon gonadal and gonadotropic functions, and their antitumoral action. More specific problems will then be discussed: side effects, resistance, possibility of cure, the evolution of the prolactinoma, the place of medical therapy relative to surgery, and contraception in association with dopaminergics.

Adenoma↗
PubMed1982

[Bromocriptine treatment of prolactinomas and primary hyperprolactinemia (author's transl)].

The therapeutic efficacy of bromocriptine was evaluated in 48 patients; 27 with macroadenomas (16 cases before and 10 cases after surgery, and 1 isolated case); 16 with suspected microadenomas; 5 cases with primary hyperprolactinaemia and a normal sella turcica, for which the product had been prescribed alone for 1 to 4 years. Pretreatment with bromocriptine may provide for postoperative recovery this never occurring after surgery alone, whether or not it is followed by radiotherapy. Though the therapeutic effect is usually constant in other cases, recovery is rarely obtained even after prolonged treatment; it was observed in only 2 of the 21 cases treated.

Adenoma↗