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Biomedical subjects

T Lang

Publications and source records attributed to T Lang.

At least 145 records · Page 8Linked to original sources
PubMed1997

Incidence, case fatality, risk factors of acute coronary heart disease and occupational categories in men aged 30-59 in France.

OBJECTIVES: To assess the incidence and case fatality rate (CFR) from acute coronary insufficiency in men among occupational categories and to analyse the relationship between these disparities and the distribution of cardiovascular risk factors in the French population. SETTING: Three registers of the WHO-MONICA project in France: the urban area of Lille and two French districts: Bas-Rhin and Haute-Garonne. METHODS: Two sets of data were used: 1) the incident cases collected by the three MONICA Collaborating Centres (MCC) of the French WHO-MONICA Project (Lille, Strasbourg and Toulouse), between 1985 and 1989; 2) a cross-sectional study on cardiovascular risk factor prevalence performed in 1985-1989 in the three areas corresponding to the MCC. SUBJECTS: The data concern 5133 new coronary events in men aged 30-59 and a sample of 1863 men aged 30-59. RESULTS: A strong relationship was observed between occupational categories and the incidence of acute myocardial infarction and coronary events as well as CFR. Both incidence and CFR were lower among senior executives. Incidence was higher among employees and workers. However, employees, as opposed to unskilled workers, did not have higher CFR. Using occupational category as a statistical unit, the incidence of first acute myocardial infarction and coronary events was associated with the prevalence of smokers in the population (r = 0.50, P = 0.06 and r = 0.61, P = 0.02). The CFR was associated with systolic blood pressure (r = 0.82, P = 0.002), and the prevalence of smokers (r = 0.65, P = 0.02). None of the measures of incidence or case fatality among categories was related to cholesterol, HDL-cholesterol or body mass index. CONCLUSIONS: Strong differences were observed between occupational categories and the incidence of acute myocardial infarction, coronary events and CFR. These differences were found to be closely related to the social distribution of two major cardiovascular risk factors: tobacco smoking and blood pressure.

Adult↗
PubMed1997

Percutaneous endoscopic gastrostomy in children and adolescents.

BACKGROUND: Long-term nasogastric tube feeding is often associated with irritation of the hypopharynx or dislocation of the tube. These pitfalls may be circumvented by percutaneous endoscopic gastrostomy. Although frequently used in adults, there is limited experience with the procedure in children. METHODS: A series of 139 patients (aged 3 weeks to 36.5 years, mean age, 4.4 years; weight 3.1-60 kg, mean weight, 15 kg) underwent placement of a percutaneous endoscopic gastrostomy because of central dysphagia (n = 103); general dystrophy caused by chronic renal failure, congenital heart disease, neoplasms, or cystic fibrosis (n = 26); requirement for special diets (n = 7); malnutrition related to respiratory insufficiency (n = 2); and gastric volvulus (n = 1). RESULTS: The percutaneous endoscopic gastrostomy was placed either in the stomach (n = 122) or in the duodenum (n = 15). In two patients a direct percutaneous endoscopic jejunostomy was performed, because duodenal placement proved impossible. Percutaneous endoscopic gastrostomies were placed using intravenous sedation (midazolam, etomidate, or diazepam). None of the patients required general or inhalation anesthesia. We observed 19 complications including: dislocation of the duodenal part into the stomach (n = 5); inflammation at the insertion site (n = 3); perforation of the stomach (n = 2), which healed under conservative treatment; disconnection of the retention disk (n = 4); occlusion of the tube (n = 4), and chronic vomiting (n = 1). Mean lifetime of a percutaneous endoscopic gastrostomy was more than 1 year. CONCLUSIONS: Percutaneous endoscopic gastrostomy provides a major improvement for children requiring long-term tube feeding. High efficacy and low rates of complication suggest that percutaneous endoscopic gastrostomy should be considered more often, even in infants.

Adolescent↗
PubMed1997

The early postoperative morbidity of transurethral resection of the prostate and of 4 minimally invasive treatment alternatives.

PURPOSE: We compared the early postoperative morbidity of transurethral resection of the prostate to minimally invasive treatment alternatives with respect to the objective rate of complications and subjective morbidity assessed by a patient addressed diary-type questionnaire. MATERIALS AND METHODS: Parameters evaluated preoperatively were the International Prostate Symptom Score (I-PSS), free flow study, post-void residual, transrectal ultrasonography and a pressure-flow study. The patients underwent transurethral resection (28), transrectal high intensity focused ultrasound (20), visual laser ablation (15), transurethral needle ablation (15) and transurethral electrosurgical vaporization (17) of the prostate. On the day of hospital discharge the patients received the questionnaire and were asked to answer daily 7 questions concerning micturition status. After 6 weeks the questionnaire was returned and an I-PSS, uroflowmetry and post-void residual were obtained. RESULTS: Preoperatively, there was no statistically significant difference regarding the I-PSS, peak flow rate, prostate volume and degree of bladder outlet obstruction. After 6 weeks the peak flow rate improved most prominently after transurethral electrosurgical vaporization (+ 13.2 ml. per second), transurethral resection of the prostate (+ 12.3 ml. per second) and visual laser ablation (+ 11.1 ml. per second). The I-PSS decreased most significantly after transurethral resection (-14.1) and transurethral electrosurgical vaporization (-8.4). There was no difference regarding the rate of adverse events within the first 6 weeks postoperatively in the 5 treatment arms. Mean duration of catheter drainage plus or minus standard deviation was 3.7 +/- 1.2 days after transurethral resection of the prostate, 6.8 +/- 1.7 days after high intensity focused ultrasound, 7.8 +/- 1.5 days after visual laser ablation, 2.0 +/- 0.4 days after transurethral needle ablation and 3.3 +/- 0.8 days after transurethral electrosurgical vaporization. Analysis of the questionnaire revealed that the daytime frequency, degree of hematuria and incontinence were comparable for all 5 procedures within the first 6 weeks postoperatively. Postoperative dysuria was greatest after visual laser ablation and transurethral electrosurgical vaporization. Regarding the degree of nocturia, there was no improvement after visual laser ablation, while the remaining 4 procedures yielded a significant and comparable decrease. The most significant subjective improvement in uroflowmetry was reported after transurethral resection of the prostate and transurethral electrosurgical vaporization. Regarding the global quality of life question, the patients were generally more worried after visual laser ablation and transurethral needle ablation compared to the other 3 procedures. CONCLUSIONS: The overall morbidity of transurethral resection of the prostate within the first 6 weeks postoperatively is equivalent to that of the 4 minimally invasive treatment alternatives evaluated in our study. When comparing the 4 minimally invasive procedures, no dramatic differences were notable, although visual laser ablation seems to be associated with a greater degree of morbidity as assessed by this questionnaire.

Aged↗
PubMed1997

Nramp1 transfection transfers Ity/Lsh/Bcg-related pleiotropic effects on macrophage activation: influence on antigen processing and presentation.

The natural resistance-associated macrophage protein (Nramp1) regulates macrophage activation. One of its pleiotropic effects on macrophage function is to regulate expression of major histocompatibility class II molecules. In this study macrophages stably transfected with the wild-type (infection-resistant) or the natural mutant (infection-susceptible) allele of the Nramp1 gene were used to study class II expression and processing and presentation of recombinant protein antigens to CD4+ T-cell hybridomas. As demonstrated previously for macrophages from Nramp1-resistant and -susceptible congenic mouse strains, transfected macrophage clones carrying the wild-type allele showed enhanced upregulation of class II molecules in response to gamma interferon compared to that shown by macrophage clones carrying an endogenous mutant allele or transfected with the mutant allele expressed under a viral long terminal repeat promoter. The wild-type allele-transfected macrophage clones also demonstrated an enhanced, lipopolysaccharide-dependent ability to process the recombinant leishmanial antigen LACK-delta 1 (the Leishmania homolog of receptors for activated C kinase) for presentation to LACK-specific CD4+ T cells. An influence on antigen processing must therefore be added to the growing list of pleiotropic effects of the Nramp1 gene potentially contributing to its role in infectious and autoimmune disease susceptibility. These results also have important implications for analysis of T-cell responses to vaccination, especially where antigens are presented to the immune system using live Salmonella species or Mycobacterium bovis BCG as a vaccine vehicle.

Animals↗
PubMed1997

Synthesis, stability, and subcellular distribution of major histocompatibility complex class II molecules in Langerhans cells infected with Leishmania major.

Protozoan parasites of the genus Leishmania exist as obligatory intracellular amastigotes and invade macrophages and Langerhans cells, the dendritic cells of the skin. Langerhans cells are much more efficient in presenting Leishmania major antigen to T cells than macrophages are and have the unique ability to retain parasite antigen in immunogenic form for prolonged periods. To analyze the mechanisms that are responsible for this potency, we defined the synthesis, turnover, conformation, and localization of major histocompatibility complex (MHC) class II molecules in Langerhans cells. Hence, Langerhans cells were pulse-labeled; immunoprecipitation of MHC class II molecules and gel electrophoresis followed. In addition, the subcellular distribution of MHC class II molecules in L. major-infected Langerhans cells was analyzed by confocal microscopy. The results show that (i) newly synthesized MHC class II molecules are required for L. major antigen presentation by Langerhans cells, (ii) MHC class II-peptide complexes in Langerhans cells are long-lived, (iii) phagocytosis of L. major modulates MHC class II biosynthesis by reducing its downregulation during Langerhans cell differentiation, and (iv) newly synthesized MHC class II molecules are associated with the parasitophorous vacuole of infected Langerhans cells. These findings support the conclusion that the traits of MHC class II expression correspond to the highly specialized functions of Langerhans cells in the immunoregulation of cutaneous leishmaniasis.

Animals↗
PubMed1997

Predicting the outcome in elderly patients of hospital admission for acute care in Paris, France: construction and initial validation of a simplex index.

OBJECTIVE: To develop a simple index able to identify at an early stage those elderly patients at high risk of requiring discharge to a residential or nursing home after admission to hospital for acute care. For these patients, early discharge planning might lead to a more effective management and reduce the length of hospitalisation. DESIGN, SETTING, AND PATIENTS: This was a prospective study conducted in two teaching hospitals in Paris, France. A total of 510 consecutive patients was included. They were aged 75 years or more and had been admitted to acute medical care units through the emergency department. MEASUREMENTS: Demographic data, social support, physical disability, mental disability, and pathologic status were assessed shortly after admission (within 24-48 hours). MAIN OUTCOME MEASURES: Outcome of hospitalisation was defined as discharge to home or residential/nursing home. RESULTS: The index, developed by multiple logistic regression, included six variables: the wish of patients' principal career about their returning home after acute hospitalisation, presence of a chronic condition, ability to perform toileting, ability to know the name of the hospital or the city, their age, and their living arrangements. The sensitivity of the index in identifying patients at high risk of requiring discharge to a residential/nursing home was 74.4%, the specificity 63.8% the positive predictive value was 57.8%, and the negative predictive value was 80.6%. CONCLUSIONS: The simple index, using data available very early in the course of hospitalisation, provides an accurate prediction of the hospitalisation outcome. The performance of the index should be tested in other populations and the practical benefits of risk screening should be assessed in a controlled trial to evaluate whether the intervention is useful and without any adverse effects.

Activities of Daily Living↗
PubMed1997

A preliminary evaluation of the lunar expert-XL for bone densitometry and vertebral morphometry.

We have evaluated the Lunar Expert-XL for standard bone mineral densitometry (BMD) and for morphometric imaging of the spine in the lateral projection. The short-term precision in vitro of the Expert-XL for BMD measurements was 0.7% for the Hologic and European spine phantoms, and the long-term stability (15-month) measurements had a 1.1% coefficient of variation. The precision in vivo for three operators examining a group of 10 premenopausal women was 0.9-1.5% for lumbar spine (L2-L4), 1.7-2.2% for the femoral neck, and 0.9% for the total hip region of interest. For a group of nine postmenopausal women, the lumbar spine, femoral neck, and total femur precision ranges were 2.0-2.4, 1.2-2.9, and 1.6-1.7% respectively. For L2-L4, BMD comparison between the Expert-XL and DPX-L yielded a correlation coefficient of r = 0.98, a slope of 0.86, and an intercept of 0.139 g/cm2. The femoral neck results were r = 0.92, slope = 1.00, and intercept = 0.03 g/cm2. In an evaluation of the Expert-XL for lateral morphometry, we employed a group of 16 postmenopausal women. Comparison of vertebral dimensions between the Expert-XL and radiographic morphometry showed strong agreement (r = 0.97), but the interobserver variability for vertebral height was higher for the Expert-XL than for radiographs (3-5% vs. 1-2%). In a subset of four women who had repeat scans, the interscan precision for measuring vertebral dimensions was 1.9, 4.1, and 43% for the L1-L4, T12-T8, and T7-T5 levels respectively. In the Expert-XL images, it was possible to identify clearly L4-T4 in 10 of 16 patients and L4-T6 in 15 of 16, indicating potential utility for vertebral fracture prescreening.

Absorptiometry, Photon↗
PubMed1997

Serial tissue polypeptide specific antigen determination in the followup of hormone treated carcinoma of the prostate.

PURPOSE: We determined the impact of serum cytokeratin-18-related tissue polypeptide specific antigen (TPS) in monitoring hormone treated carcinoma of the prostate. MATERIALS AND METHODS: From 1991 to 1996, serial TPS and prostate specific antigen (PSA) determinations (3,882) in 443 hormone treated prostate carcinoma patients were correlated with the clinical course for a mean of 22 months. RESULTS: Elevated TPS levels were significantly associated with disease progression in hormone treated stage M1 carcinoma of the prostate (p = 0.001), even in high grade, PSA negative tumors. Post-therapy TPS declines following second line therapy in hormone refractory prostate cancer patients (92) correlated significantly with subjective response (p = 0.001, PSA p = 0.02) and progression-free survival time (r(s) = -0.76, PSA r(s) = -0.32). A TPS decrease of more than 50% coincided with palliation in 90% of patients (PSA 64%) and predicted the best chance of a longer progression of free survival (p < 0.00005, PSA p = 0.036). Vice versa, rising TPS levels (more than 20%) coincided with subjective response in only 1 of 37 patients (PSA 9 of 33). CONCLUSIONS: TPS may be a useful adjunct to PSA in monitoring hormone refractory, metastasized prostate cancer.

Aged↗
PubMed1996

Production of IL-4 and IL-10 does not lead to immune quiescence in vascularized human organ grafts.

The delineation of T helper cell subsets into T helper type 1 (Th1) and T helper type 2 (Th2) populations based on the production of specific cytokines has been useful in understanding the regulation and progression of immune-based pathologies. In order to test the relevance of this concept to human solid organ transplantation, in situ and system Th1 and Th2 cytokine profiles were characterized in liver allograft recipients. Bile and serum samples obtained posttransplant were analyzed for the cytokines IL-2, IFN-gamma, IL-4, and IL-10. Significant elevations of IL-4 and IL-10 were measured at the site of graft rejection. In contrast, IL-2, IFN-gamma, and IL-4 were markedly elevated in the circulation during rejection. Analyses of sequential bile samples revealed that Th1 and Th2 cytokines showed similar kinetics of production in response to alloantigen. Taken together, these results indicate that acute rejection of human allografts can proceed [correction of procede] in the presence of minimal levels of the Th1 cytokines IL-2 and IFN-gamma and high levels of IL-4 and IL-10.

Bile↗
PubMed1996

Increased expression of blood mononuclear cell nitric oxide synthase type 2 in rheumatoid arthritis patients.

Nitric oxide (NO) is an important inflammatory mediator in nonhuman animal models of rheumatoid arthritis (RA). The purpose of the present study was to determine whether blood mononuclear cells from patients with active RA (as compared to control subjects) have higher levels of NO synthase type 2 (NOS2) and produce more NO in vitro. Leukocytes from 25 RA patients and 20 normal subjects were examined. Arthritis activity was assessed by tender and swollen joint counts, duration of morning stiffness, patient assessment of pain, physician and patient global assessment of disease activity, the modified Stanford Health Assessment Questionnaire, and by blood levels of acute phase reactants. Blood mononuclear cell NOS enzyme activity/antigen content and nitrite/nitrate formation in vitro were measured. Blood mononuclear cells from RA patients had increased NOS activity and increased NOS2 antigen content as compared to those from normal subjects, and responded to interferon-gamma with increased NOS expression and nitrite/nitrate production in vitro. NOS activity of freshly isolated blood mononuclear cells correlated significantly with disease activity, as assessed by render and swollen joint counts. Our results demonstrate that patients with RA have systemic activation for NOS2 expression, and that the degree of activation correlates with disease activity. Increased NOS2 expression and NO generation may be important in the pathogenesis of RA.

Adult↗
PubMed1996

Presentation of the protective parasite antigen LACK by Leishmania-infected macrophages.

Macrophages are apparently the only cells that in vivo allow the growth of the intracellular pathogen Leishmania. They are thus generally considered as likely candidates for the presentation of parasite Ag to CD4+ T lymphocytes known to be involved in protective and counterprotective immune responses. In the present study, we examined whether mouse macrophages infected with Leishmania were capable of stimulating T cell hybrids and a T cell clone reacting with the previously identified protective Ag LACK (Leishmania homologue of receptors for Activated C Kinase). This parasite protein is expressed in both promastigote and amastigote stages of Leishmania. We found that IFN-gamma-treated macrophages recently infected with live Leishmania promastigotes were fully competent to activate LACK-reactive T cells. However, at later times of infection, permissive macrophages infected with promastigotes were no longer able to present LACK, in spite of the presence of numerous intracellular parasites. This punctual presentation of LACK was apparently linked with the destruction, at least partial, of the intracellular parasites. In contrast, macrophages infected with live Leishmania amastigotes were always unable to stimulate the LACK-specific T cells. Amastigote-infected macrophages could, however, reactivate the T cells if LACK-delta(1), a recombinant form of LACK, was added as an exogenous protein in the culture medium. Similar results were obtained with all combinations tested involving macrophages from various origins, different activating cytokines (IFN-gamma, granulocyte-macrophage CSF, IL-4), several Leishmania species (L. amazonensis, L. major, L. donovani), and 15 different LACK-reactive T cell hybrids and clones. From these data, it is tempting to propose that the differentiation of promastigotes into amastigotes, which leads to a better survival of the parasites within macrophages, also allows them to go unnoticed by the immune system.

Animals↗
PubMed1996

Genotypes of the vitamin-D-receptor gene and bone mineral density in Caucasoid postmenopausal females.

OBJECTIVE: To evaluate the relation of bone mineral density (BMD) to inherited polymorphisms within the gene coding for the vitamin D receptor (VDR) in postmenopausal women. METHODS: DNA samples from 163 post-menopausal women and from 112 controls were genotyped for common allelic determinants within the VDR gene as defined by the restriction enzyme sites for BsmI, ApaI, and TaqI. BMD was evaluated at the lumbar spine (L2-L4) by dual energy X-ray absorptiometry. Single restriction enzyme site polymorphisms as well as their joint genotypes were evaluated for their association with BMD in postmenopausal women. RESULTS: The three restriction site polymorphisms showed a close association indicating linkage disequilibrium (P < 0.0001). There was no relationship between any of the single restriction site polymorphisms and BMD. The distribution of the five most common joint genotypes among postmenopausal women and controls was similar. There was no relation of BMD and any of the five most common VDR genotype groups. Females more than 5 years after menopause had a significantly lower BMD than those less than 5 years after menopause (P < 0.001). This age-related decrease of BMD was also decernible within genotype groups. CONCLUSION: In our population, the postmenopausal period has a major influence on BMD, but BMD is not controlled significantly by any of the common allelic variations within the VDR gene.

Absorptiometry, Photon↗
PubMed1996

Non-urgent care in the hospital medical emergency department in France: how much and which health needs does it reflect?

OBJECTIVES: The goal was to describe the use of the medical emergency department as a source of non-urgent medical care in order to assess unmet health care needs among its users. The specific objectives were thus to assess the proportion of emergency department visits for non-urgent medical care and to describe those who used the department for this reason. DESIGN: A cross sectional study was performed at the emergency department in two hospitals (around 12,000 visits per year each). Subjects were interviewed before and after the visit using a standardised questionnaire. SETTING: The medical emergency department of two university hospitals, one in Paris and one in Besançon (France). SUBJECTS: Each patient aged 15 and more attending the emergency department for a visit during 40 randomly selected periods of 12 hours was included. MAIN OUTCOME MEASURES: A definition of urgent care was adopted before the beginning of the study. Four expert judgments were then used for each case to determine whether the reason for the visit was urgent or not. RESULTS: Altogether 594 patients in the Paris emergency department and 614 in the Besançon one were included. In Besançon, the patients were older, a general practitioner was more often cited as the regular source of care, and the percentage of subsequent hospital admission was higher than in Paris (71% versus 34%). The non-urgent visits were estimated to account for 35% and 29% of the visits in Paris and Besançon respectively. Patients using the emergency department for a non-urgent visit were younger than other patients. More of them were unemployed, homeless, born outside of France, and without health insurance. CONCLUSIONS: Non-urgent use of the emergency department was observed in about one third of the visits. Groups using the department for primary care and/or non-urgent care were mostly young and socially fragile, with no regular source of health care. Their poor health condition suggests that there is a need for a structure providing primary care both inside and outside 'normal' working hours.

Adolescent↗