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C Germain

Publications and source records attributed to C Germain.

18 recordsLinked to original sources
PubMed2006

Location of major histocompatibility complex class II molecules in rafts on dendritic cells enhances the efficiency of T-cell activation and proliferation.

The existence of major histocompatibility complex (MHC) class II molecules in lipid rafts has been described in dendritic cells (DC); however, the importance of rafts in T-cell activation has not been clarified. In this study, the distribution of the lipid raft components (CD59 and GM1 ganglioside) in human monocyte-derived DC was investigated. DC had an even distribution of these components at the cell surface. In addition, raft-associated GM1 ganglioside colocalized with cross-linked MHC class II. This implies coaggregation of raft components with these MHC molecules, which may be important in the interaction between T cells and antigen-presenting cells. In studies carried out to investigate the effect of the DC : T-cell interaction on raft distribution, we found a clustering of the lipid raft component CD59 on DC at the synaptic interface, with associated activation of the interacting T cell. In an antigen-specific response between DC and CD4+ T-cell clones, disruption of lipid rafts resulted in inhibition of both CD59 clustering and T-cell activation. This was most pronounced when limiting amounts of cognate peptide were used. Together, these data demonstrate the association of MHC class II with lipid rafts during DC : T-cell interaction and suggest an important role for DC lipid rafts in T-cell activation.

CD4-Positive T-Lymphocytes↗
PubMed2005

Comparison of measurements of canine plasma creatinine, glucose, proteins, urea, alanine aminotransferase, and alkaline phosphatase obtained with Spotchem SP 4430 and Vitros 250 analyzers.

The suitability of the Spotchem 4430 benchtop biochemistry analyzer for canine blood samples was tested for creatinine, glucose, proteins, urea, alkaline phosphatases and alanine aminotransferase. Results obtained from whole blood and corresponding heparin plasma were identical except for proteins which were higher in plasma (n=10). Between series imprecision (n=10) was <5% for substrates and <10% for enzymes. Comparison of results from 100 Li-heparin samples with those measured with a Vitros 250 analyzer showed good correlation (r>0.93). The slopes of the Passing-Bablock's regression ranged from 0.90 to 1.20 and intercepts were low. The mean biases were low, except for creatinine for which the results obtained by Spotchem (Jaffe reaction) were about 20 micromol/L higher than with the Vitros (enzymatic reaction). The results of this study show that the Spotchem analyzer is suitable for use in canine whole blood or plasma when small numbers of tests are to be performed and large analyzers are not available.

Alanine Transaminase↗
PubMed2005

Grid-enabling medical image analysis.

Grids have emerged as a promising technology to handle the data and compute intensive requirements of many application areas. Digital medical image processing is a promising application area for grids. Given the volume of data, the sensitivity of medical information, and the joint complexity of medical datasets and computations expected in clinical practice, the challenge is to fill the gap between the grid middleware and the requirements of clinical applications. The research project AGIR (Grid Analysis of Radiological Data) presented in this paper addresses this challenge through a combined approach: on one hand, leveraging the grid middleware through core grid medical services which target the requirements of medical data processing applications; on the other hand, grid-enabling a panel of applications ranging from algorithmic research to clinical applications.

Computer Communication Networks↗
PubMed2003

Comparison of the techniques of evaluation of urine dilution/concentration in the dog.

The objective of this study was to evaluate the quality of the measurement of dog urine dilution/concentration by comparing osmolality with three methods of specific gravity (USG) measurement, i.e. weighing, refractometry and test strips. In unselected urine samples from 182 dogs there was a better agreement between osmolality and USG determination by refractometry (r = 0.92) than by weighing (r = 0.82) or by test strips (r = 0.27). There was an almost linear relationship between osmolality and USG: osmolality (mOsm/kg) = 36646(34318/38974) x (USGref - 1) + 25(-39/88); calculated osmolality differed from measured osmolality by more than 500 mOsm/kg in only 8 of 181 samples. There was a good agreement between USG determination by weighing and refractometry: USGref = 1.000(0.905/1.095) x USGweighing - 0.0004(-0.0019/0.0027), with a moderate bias. Only 12% of the differences between the two methods exceeded 0.010. Test strip assessment of USG was unreliable because of systematic underestimation and should not be used for dog urine. Refractometry is the best technique for routine evaluation of urine concentration/dilution when osmometry is not available.

Animals↗
PubMed2001

HLA-DP allele-specific T cell responses to beryllium account for DP-associated susceptibility to chronic beryllium disease.

Occupational exposure to small molecules, such as metals, is frequently associated with hypersensitivity reactions. Chronic beryllium (Be) disease (CBD) is a multisystem granulomatous disease that primarily affects the lung, and occurs in approximately 3% of individuals exposed to this element. Immunogenetic studies have demonstrated a strong association between CBD and possession of alleles of HLA-DP containing glutamic acid (Glu) at position 69 in the HLA-DP beta-chain. T cell clones were raised from three patients with CBD in whom exposure occurred 10 and 30 years previously. Of 25 Be-specific clones that were obtained, all were restricted by HLA-DP alleles with Glu at DP beta69. Furthermore, the proliferative responses of the clones were absolutely dependent upon DP beta Glu(69) in that a single amino acid substitution at this position abolished the response. As befits a disease whose pathogenesis involves a delayed type hypersensitivity response, the large majority of Be-specific clones secreted IFN-gamma (Th1) and little or no IL-4 (Th2) cytokines. This study provides insights into the molecular basis of DP2-associated susceptibility to CBD.

Alleles↗
PubMed2000

Human T cells elicit IFN-alpha secretion from dendritic cells following cell to cell interactions.

Major insights into events that control Th1/Th2 differentiation have been acquired recently, and highlight the role of Type I IFN in Th1 generation, by inducing up-regulation of the IL-12 receptor beta(2) subunit. IFN-alpha induces responsiveness to IL-12, and here we have investigated the source and the circumstances under which IFN-alpha is produced, in the absence of viral infections. Human dendritic cells (DC) were co-cultured with autologous T cells activated by cross-linking the CD3 complex. DC were also cultured with L cells expressing human CD40 ligand (CD40L). Our results show that large amounts (>200 IU IFN-alpha from 2.5x10(4) cells) of IFN-alpha are produced by DC following interaction with stimulated T cells. Similar effects were observed when DC were cultured with CD40L-expressing transfectants, although the amount of IFN-alpha produced was reduced, suggesting that the CD40-CD40L interaction may be important. These results show that stimulated T cells can solicit the signals from DC that allow their polarization towards a Th1 phenotype. Type I DC produce Type I IFN not only following viral infection but also during an immunological interaction and this may be the basic mechanism that assists in the development of a Th1 response.

Animals↗
PubMed1997

Frequency of human anti-FVIII antibodies in humanized SCID mice elicited by recombinant deleted factor VIII and by a plasma derived factor VIII.

SCID mice were grafted with human PBL (hu-PBL-SCID) from healthy or haemophilia A donors. Those containing human and no murine Ig in their plasma, were injected with 100 U VIII:Ag of a plasma derived (pd) FVIII or recombinant deleted Factor VIII (FVIII deltaII) and with 10 microg of tetanus toxoid as control immunogen. The frequency and the intensity of the humoral specific responses were measured in 253 mice humanized with PBL from 13 different donors. There was no significant difference in the frequency or intensity of the anti-FVIII immune responses to pd FVIII and FVIII deltaII. Neutralizing antibodies were only detected in the plasma of mice humanized with cells from haemophiliacs having FVIII inhibitors in their blood. The immune responses observed in hu-PBL-SCID mice correlated with the immune status of the corresponding human donor.

Adult↗
PubMed1997

Patient information about radiation therapy: a survey in Europe.

BACKGROUND AND PURPOSE: We performed a survey to evaluate the present status and means of information given to patients treated by radiotherapy. A short questionnaire was sent, with the help of ESTRO, to 746 European heads of department with a request to send specific documents used for informing the patient. Within 2 months (March and April 1996) we received 290 answers (39%) and 97 centres sent documents. MATERIALS AND METHODS: Analysis of the questionnaire and the documents was performed quantitatively with usual statistical methods and qualitatively with a socio-anthropological method of content analysis. RESULTS: Analysis of the questionnaire shows the major role of the radiation oncologist in giving information and writing documents. The 298 different samples sent from 97 centres represent a wide panel with a booklet of general information (59 booklets/57 centres), practical advice and specific explanations (177 documents/49 centres) and informed consent (36 documents/28 centres). The anthropological study was centred on the way information was given, evaluation of the patient's understanding and analysis of documents sent. CONCLUSION: This preliminary survey needs to be completed by a study, including the patient's point of view and needs, about the information given.

Humans↗
PubMed1983

Insulin is a physiological inhibitor of urinary zinc excretion in anesthetized dogs.

Renal clearance experiments were performed on anesthetized dogs to determine the role of insulin in regulation of urinary zinc excretion. Intravenous infusion of somatostatin (2 micrograms/min) increased zinc excretion by approximately 100%, in association with 67% decreases in the plasma concentrations of both insulin and glucagon. Infusion of insulin (30 mU X kg-1 X min-1) along with the somatostatin maintained plasma insulin constant and completely eliminated the somatostatin-induced hyperzincuria; indeed, a small decrease in zinc excretion invariably occurred. Infusion of insulin alone (60 mU X kg-1 X min-1) decreased zinc excretion in five of six dogs. Plasma zinc concentration fell progressively, but to the same extent, throughout the experiment in all protocols. None of the hormonal infusions altered glomerular filtration rate, plasma concentrations of sodium, calcium, or magnesium or urinary excretion of these cations. We conclude that insulin, at physiological plasma concentrations, exerts an inhibitory effect on urinary zinc excretion.

Animals↗
PubMed1983

Plasma renin is increased in young rats exposed to lead in utero and during nursing.

Rats were exposed continuously to Pb in utero and after birth by giving their mothers, during pregnancy and lactation, drinking water containing 0, 5, 25, 100, or 500 ppm Pb (as Pb acetate); they were sacrificed at 1 month of age, at which time their mean blood Pb concentrations were, respectively, approximately 3, 9, 19, 30, and 70 micrograms/dl. All Pb-exposed groups sacrificed by decapitation had elevated mean plasma renin activities (PRA), relative to controls. Pentobarbarbital-anesthesia and laparotomy markedly increased PRA in the 0, 100, and 500 ppm groups, but the increase was significantly less in the 100 ppm group. Renal renin concentration was normal in the 5 and 25 ppm groups, but was significantly increased in the 100 and 500 ppm groups. The ratio of plasma angiotensin II to PRA was normal in the 100 ppm group but significantly reduced in the 500 ppm group. We conclude that exposure of rats in utero and during lactation to doses of Pb which produce blood Pb concentrations similar to those generally present in human populations stimulates basal renin secretion in 1-month-old rats, but partially inhibits the response to renin-releasing stimuli. The highest dose reduces plasma angiotensin II at any given PRA. These results, taken with previous publications, emphasize that the effects of lead on plasma renin even within a single species are greatly affected by the timing of the exposure.

Animals↗
PubMedDate not supplied

Autoradiography in brain of Macaca fascicularis monkeys after injection of acetyl-DL-leucine [2-14C] (Tanganil).

Acetyl-DL-leucine [2-14C]: Tanganil a antivertigal drug has been injected intravenously in two macaca monkeys which have been sacrificed 2 and 5 minutes later. Radioactivity distribution has been studied by autoradiography in the brain. An important uptake of radioactivity is localized in the cortical structures and in several tisses such as nuclei of the vestibular system, including the inner ear.

Acetylation↗
PubMedDate not supplied

[The subjective quality of life of patients with schizophrenia: influence of psychopathology and patients' expectations. A comparative study].

Most studies on the quality of life (Qol) of patients with schizophrenia deal with objective living conditions and how they are perceived by hospitalized patients. The few studies that compare Qol for patients treated in part time services with the Qol of ambulatory patients do not show any significant difference in terms of subjective Qol. Some stu-dies evaluate the influence of psychopathology and needs (or expectations) on the subjective Qol in these groups of patients. Available data indicate that the general well-being is influenced by psychopathology (positive, negative or depressive symptoms) and unmet needs in ambulatory patients. They also show that subjective Qol in certain life domains (social relations, family relations, leisure, health, law and security) is influenced by negative symptoms, anxiety and depression in patients treated in part-time services. The aim of this study is to compare the objective and subjective Qol of patients with schizophrenia treated in part time services (day hospital and day care center) to the Qol of out-patients treated on a purely ambulatory basis (out patient clinic). We studied the Qol of 2 groups of 30 patients with schizophrenia (ICD 10 criteria) treated in various centers. The first group was made of ambulatory patients, the second one was constituted of patients treated in a day hospital or a day care center. Patients were matched for age, duration of illness, number of hospitalizations. The instruments used for rating were the following: Clinical Global Impression (CGI), Global Assessment of Functioning (GAF), Positive And Negative Symptoms Scale (PANSS), Drug Attitude Inventory (DAI-10). The Qol was measured with a french version of the Lancashire Quality Of Life Profile (LQOLP) (Salomé, Germain, Petitjean, Demant and Boyer, 2000). This instrument measures the objective Qol as well as the subjective Qol. It does possess satisfying psychometric properties and offers the possibility to establish Qol profiles. All Qol ratings were carried out by a clinician who was not involved in the treatment of the patients. When the 2 groups are compared our results indicate that ambulatory patients are less symptomatic, have a better level of functioning and a better objective Qol in such domains as: finances, living situation, family relations and health. There is no significant difference in terms of anxiety and depression as measured by the respective items of the PANSS. Patients treated in part-time services present higher scores of positive symptoms. Our results indicate that there is no significant difference for subjective Qol variables between the two groups, except for general well-being, that tends to be higher in ambulatory patients. When exploring the influence of clinical data on the Qol in each group, we find negative correlations in ambulatory patients between various domains of subjective Qol and illness severity (law and security, family relations, social relations, general well-being), global functioning (family relations, social relation, health) and positive symptoms (living conditions, law and security, family relations, social relations, health). In this same group, the subjective Qol for family relations is significantly correlated with several expectations in terms of Qol improvement (leisure, social relations, family relations, transport, work). In these patients, the subjective Qol for social relations is also significantly correlated with their expectations in terms of Qol improvement (work, money, lodging, affective relations, transport). There is no significant correlation between subjective Qol and expectations in patients treated in part-time services. Our results indicate that part time services treat schizophrenic patients with a lower level of global functioning and a higher level of symptom severity compared with ambulatory patients. These results confirm other studies that show no significant difference between these 2 groups in terms of subjective Qol. The subjective Qol in the field of relations (family and social) in ambulatory patients seems particularly sensitive to illness severity, positive symptoms and global functioning level. This has also been reported by other studies. In patients treated in part-time services, the subjective Qol, particularly for living conditions and security, seems sensitive to anxiety and depression. This has also been shown by other studies. Finally, our results underline the importance of patients' expectations in terms of subjective Qol, particularly in the field of relations (family and social) for ambulatory patients.

Adult↗
PubMedDate not supplied

[An anthropological study of radiotherapy care experience].

An anthropological study has been carried out in order to evaluate the need expressed by patients undergoing radiotherapy treatment. The study was mostly qualitative and based on the radiotherapy experiences of 13 women with breast cancer and six men with head and neck cancer. A 24-year-old female anthropologist spent one year in the department of radiotherapy at the Bergonié Institute in Bordeaux. She collected data on patients' needs through the observation of their experience of treatment and personal interviews. These were put in context, analyzed both by qualitative and quantitative methods. The results point out the need for more information on the different steps of treatment and the patient's need 'for a smile' from the medical team; in other words, emphatic support.

Adult↗