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Biomedical subjects

A Bernard

Publications and source records attributed to A Bernard.

At least 19 recordsLinked to original sources
PubMed2006

Ecological association between childhood asthma and availability of indoor chlorinated swimming pools in Europe.

BACKGROUND: It has been hypothesised that the rise in childhood asthma in the developed world could result at least in part from the increasing exposure of children to toxic chlorination products in the air of indoor swimming pools. OBJECTIVES: Ecological study to evaluate whether this hypothesis can explain the geographical variation in the prevalence of asthma and other atopic diseases in Europe. METHODS: The relationships between the prevalences of wheezing by written or video questionnaire, of ever asthma, hay fever, rhinitis, and atopic eczema as reported by the International Study of Asthma and Allergies in Childhood (ISAAC), and the number of indoor chlorinated swimming pools per inhabitant in the studied centres were examined. Associations with geoclimatic variables, the gross domestic product (GDP) per capita, and several other lifestyle indicators were also evaluated. RESULTS: Among children aged 13-14 years, the prevalence of wheezing by written questionnaire, of wheezing by video questionnaire, and of ever asthma across Europe increased respectively by 3.39% (95% CI 1.96 to 4.81), 0.96% (95% CI 0.28 to 1.64), and 2.73% (95% CI 1.94 to 3.52), with an increase of one indoor chlorinated pool per 100 000 inhabitants. Similar increases were found when analysing separately centres in Western or Northern Europe and for ever asthma in Southern Europe. In children aged 6-7 years (33 centres), the prevalence of ever asthma also increased with swimming pool availability (1.47%; 95% CI 0.21 to 2.74). These consistent associations were not found with other atopic diseases and were independent of the influence of altitude, climate, and GDP per capita. CONCLUSIONS: The prevalence of childhood asthma and availability of indoor swimming pools in Europe are linked through associations that are consistent with the hypothesis implicating pool chlorine in the rise of childhood asthma in industrialised countries.

Adolescent↗
PubMed2006

Analysis of risk factors for skip lymphatic metastasis and their prognostic value in operated N2 non-small-cell lung carcinoma.

BACKGROUND: The aim of this study is to report a series and to analyze risk factors for skip lymphatic metastasis an their prognostic value in operated N2 non-small-cell lung carcinoma. METHODS: From 1997 to 2002, 142 patients classified pN2 were included in the study. Tumours were classified according to the TNM classification. Skips metastases were defined by the cases of N2 disease without lobar and interlobar and hilar lymph node involvement. A skip (+) and a skip (-) group were defined. Characteristics of tumours, ganglionar involvement and survival were analysed in both groups. RESULTS: Forty-two patients fulfilled the criteria for skip metastasis. The average number of mediastinal lymph nodes resected by patient was similar in both groups, whereas more intrapulmonary nodes were dissected in the skip (-) group (4.7 +/- 3 vs 3 +/- 3; p < 0.002). The ratio of involved to resected lymph nodes was 0.47 +/- 0.27 in the skip (-) group vs 0.23 +/- 0.20 in the skip (+) group (p < 0.0001). In the skip (+) group, 85% of the patients presenting with a right upper lobe tumour had involvement of the superior mediastinal lymph nodes against 40% in the skip (-) group. The 5-year survival rate was 48% in the skip (-) group vs 37% in the skip (+) group (p = 0.49). In multivariate analysis, incomplete resection, tumour size, extended resection and pT were significant prognostic factors. CONCLUSIONS: Skip metastasis are frequent in non-small-cell lung cancer and complete dissection of hilar and mediastinal lymph nodes should remain the surgical standard procedure for this disease. However, skip metastasis are not an independent prognostic factor in survival.

Adult↗
PubMed2006

[From the creation to the appreciation of a pedagogic Internet site in anaesthesia and intensive care].

OBJECTIVES: The aim of this study was to conceive, create, validate and assess a pedagogic site to teach students. STUDY DESIGN: Survey with questionnaires. METHODS: First, we performed an educational need assessment in that field, conducting a review of legal regulations and international guidelines and a survey of 91 students. Afterwards, we drew up a reference document based on proven scientific data, with selected bibliography and we wrote a list of specific teaching objectives. We then created a pedagogic Web site including illustrated references, documents, a selected bibliography and useful Internet links. These pedagogic Web sites could be associated to well-conducted tutorial sites by qualified senior physicians in an academic process to improve procedural skill teaching. After internal and external validation, this educational Web site was evaluated by students. This evaluation used the questionnaire proposed by "Régie Régionale de la Santé et des Services Sociaux de Montréal" (regional authority control of health and social services of Montreal). Our pedagogic Web site obtained 76 out of 100 and can be considered satisfactory. CONCLUSION: This study demonstrated that adapted multimedia tools can improve procedural skill teaching in anaesthesia and intensive care.

Adult↗
PubMed2006

[Multiple embolizations of the branches of the ophthalmic artery: an unknown serious complication of facial surgeries].

We present a patient with ocular ischemia following autologous refined fat injection (lipostructure) into the glabellar area to treat wrinkles. We think this visual loss is directly a consequence of the surgery, by retrograde arteriolar microembolus into the ophthalmic artery via peripheral anastomoses with the arteries of the face. These complications are on the rise because of the esthetic facial injections of viscous materials. We explain the pathophysiology and present a review of the litterature.

Cosmetic Techniques↗
PubMed2006

Bone marrow CD34+/B220+ progenitors target the inflamed brain and display in vitro differentiation potential toward microglia.

Recent evidence indicates that microglial cells may not derive from blood circulating mature monocytes as they express features of myeloid progenitors. Here, we observed that a subpopulation of microglial cells expressed CD34 and B220 antigens during brain development. We thus hypothesized that microglia, or a subset of microglial cells, originate from blood circulating CD34+/B220+ myeloid progenitors, which could target the brain under developmental or neuroinflammatory conditions. Using experimental allergic encephalomyelitis (EAE) as a model of chronic neuroinflammation, we found that a discrete population of CD34+/B220+ cells expands in both blood and brain of diseased animals. In EAE mice, intravenous transfer experiments showed that macrophage-colony stimulating factor (M-CSF) -expanded CD34+ myeloid progenitors target the inflamed central nervous system (CNS) while keeping their immature phenotype. Based on these results, we then assessed whether CD34+/B220+ cells display in vitro differentiation potential toward microglia. For this purpose, CD34+/B220+ cells were sorted from M-CSF-stimulated bone marrow (BM) cultures and exposed to a glial cell conditioned medium. Under these experimental conditions, CD34+/B220+ cells were able to differentiate into microglial-like cells showing the morphological and phenotypic features of native microglia. Overall, our data suggest that under developmental or neuroinflammatory conditions, a subpopulation of microglial cells derive from CNS-invading CD34+/B220+ myeloid progenitors.

Animals↗
PubMed2006

Pulmonary response to methylcyclopentadienyl manganese tricarbonyl treatment in rats: injury and repair evaluation.

Methylcyclopentadienyl manganese tricarbonyl (MMT), an organometallic compound, used as an antiknock additive in fuels, may produce alveolar inflammation and bronchiolar cell injury. The aim of the experimental study on female rats was to determine by morphological examination and sensitive biomarkers, the course of the injury and repair process following a single i.p. injection of 5 mg/kg MMT. The animals were sacrificed 12, 24, 48 hours or 7 days post-exposure (PE). The first biochemical changes 12 h PE showed an increase in GSH-S-transferase (GST) activity in the lung parallel to the earliest observed morphological changes -vacuolation and swollen cytoplasm in type I pneumocytes. Alterations in type I pneumocytes were most prevalent in rat lung 24 h PE. Clara cells with dilated smooth endoplasmic reticulum membranes and cytoplasmic vacuolation could be observed. Compared to the values found for controls, Clara cell protein (CC16) in the bronchoalveolar lavage fluid (BALF) at 24 and 48 h PE decreased by 58% and 55%, respectively. At the same time (at 24 and 48 h), the total protein concentration in BALF increased 5 and 7 times, respectively. A significant rise in hyaluronic acid (HA) level was observed 24 and 48 h PE. Divided type II pneumocyte cells and Clara cells in their mitotic phase were observed in immunocytochemistry (detecting BrdU binding into DNA) 48 h PE. Seven days after MMT administration, fibroblasts, macrophages, collagen and elastin fibres could be seen in the alveolar walls as well as neutrophils, lymphocytes, and alveoli macrophages in the alveolar lumen. We conclude that injury and repair of bronchial epithelium cells, especially of Clara cells and type II pneumocyte cells, play an important part in MMT toxicity, probably depending on the antioxidant status of these cells. The sensitive biomarkers of CC16 and hyaluronic acid in BALF and serum reflect lung injury and indicate the time course of pulmonary damage and repair processes.

Animals↗
PubMed2005

Conversion of a CHO cell culture process from perfusion to fed-batch technology without altering product quality.

During the development of a new drug product, it is a common strategy to develop a first-generation process with the aim to rapidly produce material for pre-clinical and early stage clinical trials. At a later stage of the development, a second-generation process is then introduced with the aim to supply late-stage clinical trials as well as market needs. This work was aimed at comparing the performance of two different CHO cell culture processes (perfusion and fed-batch) used for the production of a therapeutically active recombinant glycoprotein at industrial pilot-scale. The first-generation process was based on the Fibra-Cel packed-bed perfusion technology. It appeared during the development of the candidate drug that high therapeutic doses were required (>100mg per dose), and that future market demand would exceed 100 kg per year. This exceeded by far the production capacity of the first-generation process, and triggered a change of technology from a packed-bed perfusion process with limited scale-up capabilities to a fed-batch process with scale-up potential to typical bioreactor sizes of 15m(3) or more. The productivity per bioreactor unit volume (in product m(-3)year(-1)) of the fed-batch process was about 70% of the level reached with the first-generation perfusion process. However, since the packed-bed perfusion system was limited in scale (0.6m(3) maximum) compared to the volumes reached in suspension cultures (15m(3)), the fed-batch was selected as second-generation process. In fact, the overall process performance (in product year(-1)) was about 18-fold higher for the fed-batch compared to the perfusion mode. Data from perfusion and fed-batch harvests samples indicated that comparable product quality (relative abundance of monomers dimers and aggregates; N-glycan sialylation level; isoforms distribution) was obtained in both processes. To further confirm this observation, purification to homogeneity of the harvest material from both processes, followed by a complementary set of studies (e.g. full physico-chemical characterization, assessment of in vitro and in vivo bioactivity, comparative pharmacokinetics and pharmacodynamics studies in relevant species, etc.) would be required. Finally, this illustrates the need to fix the production process early during the development of a new drug product in order to minimize process conversion efforts and to shorten product development time lines.

Animals↗
PubMed2005

CC16 as a marker of lung epithelial hyperpermeability in an acute model of rats exposed to mainstream cigarette smoke.

The Clara cell secretory protein (CC16), which is produced along the tracheal-bronchial tree, has been shown to be a sensitive marker for the detection of lung hyperpermeability. Cigarette smoke inhalation has been associated with increased lung epithelial permeability. In this study we investigated the changes in CC16 in serum and bronchoalveolar lavage fluid (BALF) from female Sprague Dawley rats after a single exposure (2 x 1 h) to diluted mainstream cigarette smoke (MS) from the Reference Cigarette 2R4F. Rats were nose-only exposed to MS at concentrations of 0 (sham exposure), 250, 500, 750, 1000 or 1250 microg total particulate matter per liter. At 2, 4, 15 and 24h after exposure, serum and BALF-samples were collected. CC16 was determined in BALF and serum. Albumin in BALF, another marker for lung permeability was also determined. A trend towards a lower CC16 recovery was observed in BALF from smoke-exposed rats. The CC16 concentration in serum showed a marked (up to five-fold) concentration- and time-dependent increase after MS exposure. The increase of CC16 in serum was most prominent at the early timepoints, i.e. 2 and 4 h after exposure, and a return to baseline concentrations was obvious at 24 h after exposure. The effect of MS exposure on the amount of albumin in BALF was limited (up to 60% increase). This study clearly showed that CC16 is a good marker for the assessment of the increased permeability of the lung/blood barrier after MS-exposure.

Albumins↗
PubMed2005

Biomarkers of cadmium and arsenic interactions.

Advances in proteomics have led to the identification of sensitive urinary biomarkers of renal dysfunction that are increasingly used in toxicology and epidemiology. Recent animal data show that combined exposure to inorganic arsenic (As) and cadmium (Cd) gives rise to more pronounced renal toxicity than exposure to each of the agents alone. In order to examine if similar interaction occurs in humans, renal dysfunction was studied in population groups (619 persons in total) residing in two metal contaminated areas in China: mainly a Cd contaminated area in Zhejiang province (Z-area) and mainly a As contaminated area in Guizhou province (G-area). Nearby control areas without excessive metal exposure were also included. Measurements of urinary beta(2)-microglobulin (UB2MG), N-acetyl-beta-glucosaminidase (UNAG), retinol binding protein (URBP) and albumin (UALB) were used as markers of renal dysfunction. Urinary Cd (UCd) and total As (UTAs) were analyzed by graphite-furnace atomic absorption spectrometry. Urinary inorganic As and its mono- and di-methylated metabolites (UIAs) were determined by Hydride generation. Results. As expected, the highest UCd values occurred in Z-area (Geometric mean, GM 11.6 microg/g crea) while the highest UTAs values occurred in G-area (GM = 288 microg/g crea). Statistically significant increases compared to the respective control area were present both for UTAs, UCd and for UB2MG, UNAG and UALB in Z-area as well as in G-area. UIAs was determined only in Z area. In G-area, there was a clear dose-response pattern both in relation to UTAs and UCd for each of the biomarkers of renal dysfunction. An interaction effect between As and Cd was demonstrated at higher levels of a combined exposure to As and Cd enhancing the effect on the kidney. In Z-area an increased prevalence of B2MG-uria, NAG-uria and ALB-uria was found in relation to UCd, but no relationship to UTAs was found. A statistically significant relationship between UIAs and UB2MG was found among women in this area and an interaction between As and Cd was indicated for B2MG. Conclusion. The present studies, which employed sensitive biomarkers of renal dysfunction, give support to the idea that human co-exposure to Cd and inorganic arsenic gives rise to more pronounced renal damage than exposure to each of the elements alone, but further studies are needed to establish and clarify this interaction.

Acetylglucosaminidase↗
PubMed2005

Clara cell protein and surfactant protein B in garbage collectors and in wastewater workers exposed to bioaerosols.

OBJECTIVES: Inhalation of bioaerosols has been hypothesised to cause "toxic pneumonitis" that should increase lung epithelial permeability at the bronchioloalveolar level. Serum Clara cell protein (CC16) and serum surfactant protein B (SPB) have been proposed as sensitive markers of lung epithelial injury. This study was aimed at looking for increased lung epithelial permeability by determining CC16 and SPB in workers exposed to bioaerosols from wastewater or garbage. METHODS: Subjects (778 wastewater, garbage and control workers; participation 61%) underwent a medical examination, lung function tests [American Thoracic Society (ATS) criteria], and determination of CC16 and SPB. Symptoms of endotoxin exposure and several potential confounders (age, gender, smoking, kidney function, obesity) were looked for. Results were examined with multiple linear or logistic regression. RESULTS: Exposure to bioaerosols increased CC16 concentration in the wastewater workers. No effect of exposure on SPB was found. No clue to work-related respiratory diseases was found. CONCLUSIONS: The increase in CC16 in serum supports the hypothesis that bioaerosols cause subclinical "toxic pneumonitis", even at low exposure.

Adult↗
PubMed2005

[Results of treating rhegmatogenous retinal detachment with vitrectomy and silicone oil tamponade].

INTRODUCTION: Silicone oil is used in the treatment of rhegmatogenous retinal detachment when there is a high risk of postoperative proliferative vitreoretinopathy (PVR). This type of internal tamponade can be responsible for serious side effects. Removal of silicone oil is necessary to ensure a long-lasting functional result. The purpose of this study was to evaluate the results of using a transient internal tamponade with silicone oil. PATIENTS AND METHODS: A retrospective review of cases of rhegmatogenous retinal detachment treated with internal tamponade with silicone oil for the first time in a 1-year period (January 2001 to December 2001) was conducted. We studied the type of retinal detachment, treatment before vitrectomy and silicone oil tamponade, indication for silicone oil tamponade, surgical steps and their results, causes of recurrent retinal detachment, and final visual acuity. Anatomical success was defined as a reattached retina after silicone oil removal. RESULTS: Ninety-three patients were included. Anatomical success was achieved, after one or several procedures, in 71 patients (76.3%). The mean total number of surgical procedures was 2.6. After initial surgery, recurrence of retinal detachment after removal of silicone oil occurred in 17.0% of the cases. Recurrence of retinal detachment under silicone oil occurred in 45.1% of the cases; the cause of the recurrence was PVR in 97.6% of those patients. No serious complication of silicone oil tamponade occurred. The mean duration of the tamponade was 6.7 months. The best results were achieved among patients showing no recurrence with silicone oil: visual acuity above 4/200 in 84.6% of the patients, above 20/200 in 61.5% of the patients and above 80/200 in 20.5% of the patients. In case of recurrence with silicone oil treatment, visual acuity reached 4/200 in 70.4% of the patients and was above 20/200 in 25.9% of the patients. DISCUSSION AND CONCLUSION: The results of this study are equivalent to those of studies in which analysis was made after removal of silicone oil. Proliferative vitreoretinopathy remains the only risk factor of retinal detachment recurrence with silicone oil (p<0.01). The number of previous surgeries is not a risk factor for postoperative PVR. Retinectomy is a surgical procedure that seems to improve the results in cases of severe PVR.

Adult↗
PubMed2005

[Bowel perforation as late complication of tension-free vaginal tape].

Tension-free vaginal tape (TVT) is considered as the treatment of choice for female stress urinary incontinence. Bowel erosion is a rare complication of TVT that generally occurs a few days after surgery with a clinical picture of peritonitis and/or intestinal obstruction. Herein is reported a case of a bowel erosion with a late clinical manifestation 3 months after hysterectomy and TVT placement for genital prolapse and urinary incontinence. Bowel erosion may complicate TVT operation several months after surgery and should be considered as differential diagnosis in patients presenting with a clinical picture of peritonitis and/or intestinal obstruction.

Aged↗
PubMed2005

Intrahepatic CD4 T-Cell apoptosis is related to METAVIR score in patients with chronic hepatitis C virus.

Hepatitis C virus (HCV) infection leads to liver injury, which is thought to be immune-mediated. Apoptosis of hepatic T cells could influence histological damage. We quantified peripheral and intrahepatic T-cell apoptosis in 28 patients with chronic hepatitis C by using cytofluorometric techniques. METAVIR score and HCV plasma viral load were determined. Six liver biopsies, obtained from controls without chronic hepatitis during hepatobiliary surgery, served as controls. In patients, liver T-cell apoptosis was upregulated compared to peripheral T cells: 35 versus 7% for CD4+ and 56 versus 13% for CD8+ T cells (P < 0.001). Liver T-cell apoptosis levels from patients were increased compared to controls for both CD4+ (P = 0.041) and CD8+ T cells (P = 0.007). Nine patients exhibiting METAVIR scores A and F < or = 1 showed higher intrahepatic CD4+ T-cell apoptosis compared to the 19 patients with a higher METAVIR score (P = 0.001) and both histological activity and fibrosis were related to apoptosis level. There was also an inverse relationship between the level of intrahepatic CD8+ T-cell apoptosis and serum transaminase activity (P = 0.023). Our study shows immune compartmentalization, suggesting that the study of peripheral blood lymphocytes may not be fully relevant to the pathophysiology of HCV hepatitis, and that the severity of liver injury is inversely correlated with intrahepatic CD4+ T-cell apoptosis.

Adult↗
PubMed2005

Intracytoplasmic sperm injection with motile and immotile frozen-thawed testicular spermatozoa (the Hungarian experience).

The authors summarize their experience in 75 in vitro fertilization cycles, where frozen-thawed testicular spermatozoa were used for intracytoplasmic sperm injection. In 32 cases, motile spermatozoa could be observed in the frozen-thawed sample. In 34 cases, motility could be induced by pentoxifylline and in nine cases immotile spermatozoa, selected with hypoosmotic swelling test, were used for fertilization. The fertilization rates obtained with motile and immotile spermatozoa (66.1% versus 52.3%) were not significantly different. Our data demonstrate that freezing of testicular spermatozoa opened new possibilities for the treatment of azoospermic men. The clinical pregnancy rate per embryo transfer (ET) (21.87%) was comparable with previous results use of fresh testicular spermatozoa (27.7%). The quality and number of transferred embryos had the most significant impact on the pregnancy rate. The fertilization rate and frequency distribution of good-quality embryos were lower in the case of immotile spermatozoa, and pregnancies were only achieved when motile spermatozoa had been used.

Adult↗
PubMed2005

Gender dependent accumulation of dioxins in smokers.

AIMS: To evaluate the contribution of tobacco smoking to dioxin accumulation. METHODS: Dioxin (17 PCDD/F) concentrations in fasting blood from 251 subjects (161 never smokers, 54 past smokers, and 36 current smokers) were quantified. RESULTS: Whereas serum dioxin concentrations of male smokers were on average 40% higher than those of non-smokers, in women, smoking was associated with significantly lower serum dioxin levels. A synergistic potentiation of dioxin metabolism by tobacco smoke in women is postulated to explain these paradoxical findings. CONCLUSIONS: Current smoking is associated with gender dependent effects on dioxin body burden and is a potential source of confounding in human studies using blood dioxins as indicators of exposure.

Adult↗
PubMed2005

Pneumoproteins as a lung-specific biomarker of alveolar permeability in conventional on-pump coronary artery bypass graft surgery vs mini-extracorporeal circuit: a pilot study.

BACKGROUND: Despite improvements of the heart-lung machine (HLM), oxidative stress and subsequent damage to the alveolar capillary membrane still occur after conventional on-pump coronary artery bypass graft (CCABG) surgery. In an attempt to further improve the conventional HLM, a mini-extracorporeal circuit (MECC) was introduced. This new concept is based on minimal volume shifts. The extent of alveolar injury that is associated with this new technique is unknown. The lung-specific biomarkers Clara-cell 16 (CC16) and KL-6 are applied in this study to quantify alveolar dysfunction in both techniques. METHODS: In a prospective observational setting, the concentrations of CC16 and KL-6 were measured during and after 10 consecutive CCABG operations and 10 consecutive coronary artery bypass graft (CABG) operations using MECC (MCABGs). These pneumoproteins were measured after the induction of anesthesia, before clamping of the ascending aorta, after unclamping of the aorta, on arrival to the ICU, and on the following days until discharge. Quantification of the differences of KL-6 and CC16 leakage through the alveolar membranes between the two techniques was realized by calculation of the Student t test. Perioperative and postoperative shunt fractions and clinical observations were monitored simultaneously. The potential value of pneumoproteins as biomarkers for quantification of alveolar permeability during CABG surgery was tested. RESULTS: Significantly reduced concentrations of CC16 were found early after MCABG as compared to CCABG surgery (p = 0.033). KL-6 showed no consistent pattern during both treatment modalities. Early after CCABG surgery, shunt fractions tended to show reduced oxygen transport over the alveolar membrane as compared to MCABG surgery. CONCLUSION: CC16 appears to be a useful biomarker for alveolar permeability during CABG surgery. Injury of the alveolar capillary membrane appears significantly reduced during MCABG surgery. Consistently early postoperative alveolar shunt fractions showed an increased value in CCABG compared to MCABG surgery in the early postoperative phase. Further randomized studies need to confirm the value of CC16 as marker in monitoring alveolar capillary damage during coronary bypass grafting.

Aged↗