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Biomedical subjects

A Tridon

Publications and source records attributed to A Tridon.

At least 19 recordsLinked to original sources
PubMed2003

Increase in complement component C3 is an early response to experimental magnesium deficiency in rats.

The importance of the inflammatory process in the pathology of experimental Mg-deficiency has been reconsidered but the sequence of events leading to inflammatory response remains unclear. In this study, the effect of Mg-deficiency on complement system by measuring total C3 concentration, mRNA abundance for rat pre-pro complement C3 in liver by RT-PCR, complement haemolytic activity and C3 activation by Western Blot was studied. Weaning male Wistar rats were fed either Mg-deficient or control experimental diets for 2 or 8 days. At 8 days, a characteristic inflammatory response of Mg-deficiency including hyperaemia, leukocytosis and enlarged spleen was accompanied by an increase in the total C3 quantity in plasma. Moreover, at 8 days, RT-PCR analysis indicated higher level of mRNA rat pre-pro complement C3 in liver from Mg-deficient rats compared to control rats. Even if the inflammatory syndrome was not observed in rats after 2 days, total plasma C3 was shown to be significantly increased as compared to total plasma C3 level in control rats. Because of the high variability of complement haemolytic activity values in Wistar rats, weaning male Sprague-Dawley rats were used in a second experiment. At 8 days, the inflammatory response of Sprague-Dawley rats was accompanied by an increase in total C3 quantity and by a higher haemolytic activity. The Western Blot technique failed to display distinct bands resulting from C3 cleavage in plasma from Mg-deficient rats. Since, the complement C3 is a positive acute phase reactant, the elevation of C3 indicates that the modification of inflammatory response is an early event of Mg-deficiency. However, complement activation does not appear to be involved in the acute phase of the deficiency.

Animals↗
PubMed2002

High magnesium concentration in vitro decreases human leukocyte activation.

In view of experimental data suggesting that pharmacological magnesium (Mg) therapy could be expected to temper hypersensitivity, the aim of the present study was to assess the effect of in vitro high Mg concentration (8 mmol/l vs. 0.8 mmol/l) on human leukocyte activation. The first experiment in nine healthy volunteers was performed on total leukocyte suspension containing 82 +/- 4 per cent of neutrophils. The results demonstrate the inhibitory effect of high Mg concentration as shown by the significant reduction of superoxide anion production following phorbol myristate acetate (PMA) or formyl-methionyl-leucyl-phenylalanine (fMLP) activation. Moreover, neutrophils activated with fMLP showed an increased respiratory burst when incubated in low Mg concentration (0.2 mmol/l) as compared to normal Mg concentration (0.8 mmol/l). Similarly, high concentration of Mg resulted in a significant reduction in superoxide anion production by eosinophils in response to PMA in five eosinophilic patients. In patients showing Hymenoptera venom hypersensitivity, high Mg concentration resulted in a significant reduction of sulphidoleukotrienes production by leukocytes in response to venom allergen (six patients) or in response to zymosan activated particules (fourteen patients). Taken together, the results suggests that Mg acts via a non specific mechanism and appears to be non specific to a particular cell type. As Mg counteracts calcium in many physiological and pathological processes, it is reasonable to hypothesise that extracellular Mg can diminish leukocyte activation by its calcium antagonism.

Anions↗
PubMed2002

[Analysis of eosinophilia and ECP levels in blood and nasal secretions of 119 nasal polyposis patients].

OBJECTIVE: The aim of this prospective study was to determine eosinophilia and ECP (Eosinophilic Cationic Protein) levels in blood and in nasal secretions of patients with nasal polyposis (NP). PATIENTS: 119 patients with NP were prospectively studied. The control group included 25 patients. METHODS: They included: questionnaire about asthma and intolerance to aspirin; nasal endosopic grading; nasal symptoms scoring; allergy testing; measurements of serum and nasal values of eosinophilia expressed as a percentage; measurements of serum and nasal values of ECP expressed in ng/ml; the Spearman correlation test, the T series and Khideux tests were used in the statistical analysis. RESULTS: In NP group, 66 were asthmatic (As) and 53 non asthmatics (NAs), 40 were atopic (ATo), and 79 were non atopic (NAto). Values of nasal eosinophilia and nasal ECP in NP patients were significantly higher (respectively 40.7+/-35.6% and 22.8+/-48.0 ng/ml) than the control group (respectively 3.0+/-14% and 2.1+/-3.6 ng/ml). Nasal and serum eosinophilia values in asthmatic patients (As) (respectively 47+/-36% and 7.6+/-6.3%) were significantly higher (p<0.05) than in non asthmatic patients (NAs) (respectively 32.6+/-33.8% and 4.6+/-3.1%). No difference was found in nasal and serum ECP values between asthmatic and non asthmatic patients. Nasal eosinophilia values were significantly correlated (p=0.02) with nasal scoring in NP patients. No correlation was found between nasal ECP and serum ECP values and clinical scoring. CONCLUSION: Nasal eosinophilia and nasal ECP values are significantly increased in NP. Nasal eosinophilia seems to be a relevant biological marker of clinical severity (association with asthma and a high clinical score) in NP patients. By contrast, nasal ECP cannot be consider as a marker of clinical severity.

Adult↗
PubMed2001

[Chronic urticaria and Hashimoto-Hashimoto's thyroiditis: report of 6 cases].

PURPOSE: Chronic urticaria is a common skin disorder. The cause is rarely determined. Autoimmune diseases, particularly autoimmune thyroiditis, have been implicated in the occurrence of chronic urticaria. METHODS: We reviewed clinical records of patients with Hashimoto's disease and chronic urticaria. RESULTS: In our department, six patients had presented chronic urticaria associated with Hashimoto's thyroiditis: four patients, of which three treated with L-thyroxine were euthyroid, the other two were hypothyroid. Hashimoto's thyroiditis had been diagnosed for three patients during the investigation of chronic urticaria. Three patients developed chronic urticaria though they were treated with thyroid suppression for Hashimoto's disease. Two of them had a dramatic improvement with opotherapy. One patient who was euthyroid without treatment improved with hormonal therapy. The fourth patient had a partial remission with thyroid hormones and was cured with corticotherapy. CONCLUSION: The mechanism by which thyroid autoimmunity is associated with urticaria is poorly understood. A cross-linking of IgE receptors of mastocytes induced by antithyroid antibodies may be a cause of histamine release. Hormonal therapy may be a potent event for the clinical improvement by the suppression of chronic thyroid stimulation. Assay of thyroid hormone and antithyroid antibodies should be performed in patients with chronic urticaria. Discovery of Hashimoto's thyroiditis with chronic urticaria requires thyroid hormone replacement not only in hypothyroid but also euthyroid patients.

Adult↗
PubMed2001

[Ophthalmologic manifestations of systemic vasculitis: report of six cases and review of the literature].

PURPOSE: Study of characteristics of ocular involvement in systemic vasculitis. METHODS: We describe six cases of systemic vasculitis with ocular involvement observed between 1992 and 2000. These cases are compared with those reported in the literature. RESULTS: Our patients suffered from Wegener's granulomatosis (four cases), periarteritis nodosa and Churg-Strauss syndrome. Ocular manifestations were conjunctivitis, scleritis, orbital pseudotumor, optic neuritis and extraocular muscle palsy. These manifestations are similar to those reported in the literature. Their treatment requires steroids and immunosuppressive drugs. In one of our cases, intravenous immunoglobulins were effective in controlling an optic neuritis. CONCLUSION: Ocular involvement in systemic vasculitis may concern any orbital structure. It usually occurs during the course of vasculitis but may be one of its first manifestations. It requires an appropriate treatment to prevent ophthalmic complications and especially blindness.

Adrenal Cortex Hormones↗
PubMed2001

Specific and nonspecific immune responses to fasting and refeeding differ in healthy young adult and elderly persons.

BACKGROUND: Undernutrition is a main cause of immunodeficiency. Many confounding factors limit the interpretation of immune function in hospitalized elderly patients. OBJECTIVE: We compared the effects of short-term fasting and refeeding on lymphocyte subset distribution and neutrophil function in healthy subjects. DESIGN: Seven young adult (x +/- SE age: 24 +/- 2 y) and 8 elderly (71 +/- 3 y) subjects were fed standardized diets (1.6 x predicted resting energy expenditure; 16% protein) for 7 d. They then fasted for 36 h and were refed for 4 h (42 kJ/kg). Lymphocyte subsets were quantified by using fluorochrome-conjugated monoclonal antibodies. Neutrophil chemotactic migration was evaluated by using a 2-compartment chamber. Neutrophil reactive oxygen species production was measured by using a luminol-amplified chemiluminescence assay and oxidation of 2'7'-dichlorofluorescein diacetate. RESULTS: Baseline total and cytotoxic T lymphocyte subpopulations were lower in elderly than in adult subjects (P < 0.01). Nutritional state had a significant effect (P < 0.05) on total, helper, and cytotoxic T and B lymphocyte counts in all subjects, and the response of lymphocyte subpopulations to nutritional fluctuations was significantly affected by age. The chemotactic index was lowered by fasting in both groups (P < 0.05 compared with basal values). After refeeding, neutrophil migration was restored in adult but not elderly subjects. The superoxide anion production rate increased with fasting and reverted to prefasting values with refeeding in both groups (P < 0.05). Fasting induced a significant decrease in hydrogen peroxide production in stimulated neutrophils that was reversed by refeeding in adult but not elderly subjects. CONCLUSION: The lack of response of lymphocyte subpopulation counts and neutrophil function to nutritional changes may help to explain the proneness of elderly persons to infection.

Adult↗
PubMed2001

Leptin: a potential regulator of polymorphonuclear neutrophil bactericidal action?

It is well known that leptin, the ob gene product, is involved in the regulation of food intake and thermogenesis. Recent studies also demonstrate that leptin may be able to modulate functions of cells involved in nonspecific immune response such as phagocytosis and secretion of cytokines by macrophages. This and the prominent implication of polymorphonuclear neutrophils (PMNs) in infectious response suggested a possible role of leptin as a modulator of PMN functions. We detected a leptin receptor on the PMN membrane by immunocytochemistry with an anti-leptin receptor. Using chemiluminescence we then demonstrated that leptin enhances oxidative species production by stimulated PMNs. These results show for the first time that a functional leptin receptor is present on PMNs and that leptin may be able to influence their oxidative capacity.

Blood Bactericidal Activity↗
PubMed1999

Acquired angioedema with C1 inhibitor deficiency: is the distinction between type I and type II still relevant?

BACKGROUND: Acquired angioedemas are divided into type I associated with lymphoproliferation and type II caused by anti-C1-inhibitor antibodies. Recent reports have suggested that this distinction is not so clear-cut, mainly because of the presence of antibodies against the C1 inhibitor in some cases belonging to the type I group. We report herein 2 additional cases of acquired angioedema with anti-C1-inhibitor antibody. MATERIAL AND METHODS: One man and 1 woman had had acquired angioedema for several years. In the man, a monoclonal component had been detected several years before the present study. In the second patient, a monoclonal component was detected during the study. The following data were studied on successive blood samples collected during angioedema manifestations: complement component levels, functional activity of the classical pathway, functional and antigenic C1 inhibitor doses, ELISA test to detect autoantibodies to C1 inhibitor and Western blot analysis of the C1 inhibitor. RESULTS: In both patients, CH50 and C4 activities were decreased, and an autoantibody to C1 inhibitor was detected. In 1 case, the antibody appeared after the monoclonal component; in the second case, it appeared before and belonged to a different immunoglobulin class. CONCLUSION: Our data suggest that the distinction between type I and type II acquired angioedema is no longer valid because of overlapping in some cases.

Aged↗
PubMed1998

Electrophoretic analyses in a case of monoclonal gamma chain disease.

Abnormal low molecular weight immunoglobulin heavy chain can be detected in serum samples from patients with heavy chain disease. In this paper, we report the characterization of a gamma heavy chain in a patient suffering from a lymphoplasmocytic disorder, using immunofixation analysis and two-dimensional polyacrylamide gel electrophoresis. We demonstrate that the combination of serum protein agarose electrophoresis and two-dimensional electrophoresis (three-dimensional electrophoresis) can be used to further characterize abnormal protein bands detected by immunofixation.

Electrophoresis, Gel, Two-Dimensional↗
PubMed1997

[Mixed cryoglobulins and autoimmunity in hepatitis C].

We explored and studied cryoglobulins and autoantibodies in 149 patients with hepatitis C. 49% of untreated patients have cryoglobuliemia (36% polyclonal cryoglobulins) and 76% of ineffectively treated patients since more than 6 months (50% polyclonal cryoglobulins). Other observed cryoglobulins are half of type II and half oligoclonal. In 22 cryoglobulinemic patients before treatment, a good clinical response to IFN is induced only among patients for which cryoglobulins are negative at the end of treatment. Cryoglobulins could be indicators of viremia. The prevalence of autoantibodies is low and without clinical significance (they are more frequently detected in cryoglobulinemic patients, except anti-thyroid autoantibodies). Nevertheless, autoantibodies induced by IFN in our study (anti-thyroid autoantibodies, ANCA) are associated with clinical symptoms.

Adolescent↗
PubMed1996

[Cold agglutinins and cryoglobulinemia in a patient with hepatitis C].

OBJECTIVES: Cold agglutinins and cryoglobulins are uncommon in the same patient as observed in our case. CASE REPORT: A 74-year-old patient suffered repeated episodes of hemolytic anemia for one year and had hepatitis C anti-virus antibodies. Mixed cryoglobulinemia was found at levels which increased during episodes of acute hemolysis in addition to anti-I cold agglutinins. Two-dimensional electrophoresis revealed identical oligoclonal cold agglutinins and cryoglobulins. DISCUSSION: Unlike mixed cryoglobulinemia, cold agglutinins are not known to occur subsequent to hepatitis C infection. The identical immunoglobulins observed in our patient suggest a common origin. Chronic anti-I cold oligoclonal agglutinins are rarely observed and could be an intermediary step towards monoclonal lymphopathy as has been described in prolonged hepatitis C infection.

Aged↗
PubMed1994

[Multiple complications of monoclonal IgM].

A 64 year old woman with monoclonal IgM Kappa cryoglobulinemia had developed neurologic, vascular and bone involvements. If each features were previously reported, their association appears to be rare. The polyneuropathy was consistent with an IgM anti MAG neuropathy rather than a cryoglobulinemic neuropathy. The vascular occlusion is well known in dysglobulinemia. The diffuse osteosclerosis without medullary fibrosis or myeloproliferative disorder was as like as a Schnitzler's syndrome (chronic urticaria, osteosclerosis, monoclonal IgM Kappa gammopathy.

Cryoglobulinemia↗
PubMed1994

[Semi-invasive diffuse pulmonary aspergillosis with antineutrophil cytoplasmic antibodies. 2 cases].

We report two cases of semi-invasive pulmonary aspergillosis with a thoracic wall extension in the first case and a parietal vasculitis without Aspergillus invasion in the second. Semi-invasive pulmonary aspergillosis is an identifiable entity. It is characterized by impairment of local pulmonary defense mechanisms and/or a mild systemic immunosuppression as well as a slowly progressive course. Pulmonary symptoms are not specific. The thoracic wall involvement subsequent to a contiguous pulmonary lesion occurs rarely and indicates poor prognosis. CT scan improves diagnosis significantly, confirmed by histology and/or by the biopsy growth of Aspergillus. Itraconazole, tolerated better than amphotericin B, is an efficient treatment though prognosis remains poor (28% of deaths). Detection of anti-neutrophil cytoplasmic antibodies (diffuse cytoplasmic staining) evolving conversely to this disease seems to be associated with infectious vasculitis. These antibodies are found in vasculitis and especially in Wegener's granulomatosis with a high specificity. They have also been described in a few patients with infectious diseases.

Aged↗
PubMed1993

Treatment of homozygous familial hypercholesterolemia by plasma exchange and LDL-apheresis.

Two girls with familial hypercholesterolemia were treated for 7 years by plasma exchanges (PE) or LDL-apheresis (LA). We compared different methods of treatment; PE with or without reuse of the plasma separator, LA of varying frequency, and LA with or without oral administration of simvastatin. We assessed the long-term results by measuring the blood levels of the biochemical parameters before sessions, and determined the effectiveness of each session by the percentage of decrease in the blood levels between the beginning and the end of the sessions. LA led to a more selective treatment (lowering of LDL cholesterol and maintenance of HDL cholesterol), but the blood levels of total cholesterol before sessions were the same as those obtained by PE. IgG and haemoglobin levels decreased little with LA. The rhythm of one session a week gave better results in LA. Although reuse of the plasma separator represents a financial saving it produced poorer results. The oral administration of simvastatin improved the results of LA.

Adolescent↗
PubMed1993

[Detection and analysis of cryoglobulins: comparative study of a population of patients and one of healthy controls].

During an 11-month period, 270 cryoglobulins were identified in 735 sera from patients versus 34 in 82 sera from apparently healthy blood donors. Western-blot analysis of the cryoglobulins was performed and cryoglobulin protein content was determined using a colorimetric assay. Comparison of findings in the two groups suggested that a substantial proportion of cryoglobulins identified in the sera of patients are quantitatively and qualitatively indistinguishable from cryoglobulins identified in healthy controls.

Bacterial Infections↗
PubMed1992

Complement activation during low-density lipoprotein apheresis.

Complement system activation was investigated in two girls with familial homozygous hypercholesterolemia undergoing two monthly sessions on LA15 or LA40 (Kaneka liposorber). We determined blood levels of C3c and C3a, leukocyte counts, and plasma levels of C3c and C3a in the extracorporeal circulation device at the start of the sessions and 15 and either 60 or 120 min into them. Sequential eluates were collected from LA40 at the end of the sessions (0.5M NaCl, 1M hydroxylamine). Anaphylatoxin C3a increased throughout, especially with LA40. As previously reported, C3a was trapped in the dextran column but was noticeably present in efferent plasma. Besides many proteins, nonnative complement fragments bearing C3a and C3d antigens were detected in almost all the eluates, suggesting possible in situ complement activation. Practically, complement activation induced by the first filter is a risk; long-term side effects may arise from this extracorporeal circulation device.

Blood Component Removal↗
PubMed1991

Analysis of proteins eluted from hemodialysis membranes.

To further investigate the types of interactions occurring between blood and hemodialysis membranes, proteins were sequentially eluted from used dialysers. Four different membranes (cuprophan, hemophan, cellulose acetate and polyacrylonitrile) were successively treated with a hydrogen bond cleaving agent (10 M urea), an ionic detergent destabilizing the hydrophobic interactions between apolar groups (SDS solution), and a hydroxylamine solution at alkaline pH to release postulated covalently bound C3 fragments. The eluted proteins were analyzed by SDS-PAGE and immunological techniques. Total protein determinations demonstrate different behaviour of the membranes as regards the 'protein cake'. Electrophoretic analysis suggests that qualitative and quantitative differences in the binding of the blood proteins are related to the membrane material. Complement fragment studies indicate that the complement activating potential of the dialysis membrane may not be determined by the availability of potential binding sites for activated C3b. An attempt is made to correlate these results with the biocompatibility concept.

Acrylic Resins↗