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Biomedical subjects

P Simon

Publications and source records attributed to P Simon.

At least 109 records · Page 6Linked to original sources
PubMed1999

Protein tyrosine dephosphorylation and the maintenance of cell adhesions in the pancreas.

Cell-cell contacts are important regulatory elements in tissue development, organ morphogenesis and malignant tumor invasion. In recent in vivo studies we have identified the members of the cadherin/catenin family of cell adhesion proteins that are differentially expressed in the pancreas and have determined their cell biological dynamics during dissociation and repair of adherens junctions. To further characterize these events, epithelial cell culture systems were used and a number of type II protein tyrosine phosphatases (PTPs) were found to colocalize and interact with the cadherin/catenin complex. These observations suggest that tyrosine dephosphorylation in general and PTPs in particular are involved in cell contact formation. Our most recent experiments indicate 1) that inhibition of PTPs alone dissociates pancreatic adherens junctions, 2) that cytosolic and transmembrane PTPs are differentially expressed in acinar cells, and 3) that a subset of them can associate with proteins of the cadherin/catenin complex at pancreatic cell-cell adhesions.

Cell Adhesion↗
PubMed1999

[Smart card systems in health care (protection, key-functions, divided data bases, applications)].

Barely more than 15 years have passed since electronic memory cards appeared, their popularity has grown rapidly (first of all as a cash-saving device and later for other purposes, as well). This is due also to the growing interest towards development of the intelligence of information systems for the follow-up of patients' health condition and medical care in countries with a highly developed health and insurance system (need for the creation of data bases divided for individuals) and also to their commitment towards a better control of the quality and costs of health care. We can come to the conclusion that the aim of research, development and the creation of systems in health informatics is to prevent illness and to give a direct informatic support to medical and nursing activity carried out in the patients' interests. The smart card and the surrounding application systems are certainly the appropriate means for the achievement of these aims.

Databases as Topic↗
PubMed1999

Probable transmission of HIV from an orthopedic surgeon to a patient in France.

BACKGROUND: Transmission of HIV from infected health care workers to patients has been documented in only one cluster involving 6 patients of a dentist in Florida. In October 1995, the French Ministry of Health offered HIV testing to patients who had been operated on by an orthopedic surgeon in whom AIDS was recently diagnosed. OBJECTIVE: To determine whether the surgeon transmitted HIV to patients during operations. DESIGN: Epidemiologic investigation. SETTING: The practice of an orthopedic surgeon in a French public hospital. PARTICIPANTS: 1 surgeon and 983 of his former patients. MEASUREMENTS: 3004 patients who had undergone invasive procedures were contacted by mail for counseling and HIV testing. One HIV-positive patient was interviewed, and DNA sequence analysis was performed to compare the genetic relation of the patient's and the surgeon's viruses. Infection-control precautions and the surgeon's practices were assessed. RESULTS: Of 983 patients in whom serologic status was ascertained, 982 were HIV negative and 1 was HIV positive. The HIV-positive patient, a woman born in 1925, tested negative for HIV before placement of a total hip prosthesis with bone graft (a prolonged operation) performed by the surgeon in 1992. She had no identified risk for HIV exposure. Molecular analysis indicated that the viral sequences obtained from the surgeon and the HIV-infected woman were closely related. Infection-control precautions were in accordance with recommendations, but blood contact between the surgeon and his patients occurred commonly during surgical procedures. CONCLUSIONS: An HIV-infected surgeon may have transmitted HIV to one of his patients during surgery.

Base Sequence↗
PubMed1999

Complications of Marchetti locked nailing for humeral shaft fractures.

In this retrospective study 50 humeral fractures (36 acute, 6 pathological fractures and 8 non-unions) were treated by retrograde locked bundled Marchetti nailing. No intraoperative complications occurred. Postoperative complications included 7 non-unions (4/36 acute fractures and 3/8 delayed union), and 2 intraarticular penetrations of the secondary nails. However, at the subsequent removal of the implant 5 supracondylar fractures occurred.

Adult↗
PubMed1999

Estimation of the percutaneous absorption of styrene in an industrial situation.

OBJECTIVE: This field study was designed to compare the level of styrene absorbed percutaneously with that absorbed by inhalation in a real situation in the fiberglass-reinforced polyester industry. METHODS: The study protocol consisted of comparisons of the patterns of urinary excretion of styrene metabolites by four groups of workers, all of whom performed the same task at the same time in the same workshop but wore the following different protective equipment: total protection with an insulating suit and mask, respiratory equipment only, percutaneous protection only, and no protection. RESULTS: The urinary excretion level of the group with total protection did not significantly differ from that of the group with respiratory protection only. CONCLUSIONS: Precutaneous absorption is not a particularly important pathway for styrene absorption during stratification work in the polyester industry. Completely insulating personal protective equipment provides no greater level of protection than does a respirator at positive pressure alone.

Analysis of Variance↗
PubMed1999

Midterm results after aortic valve replacement with the autologous tissue cardiac valve.

OBJECTIVE: To assess midterm results after aortic valve replacement (AVR) with an autologous tissue cardiac valve (ATCV). This new technique was developed to construct a tissue prosthesis for AVR using the patients pericardium, harvested at the time of operation with negligible effect on operating time. METHODS: Briefly, glutaraldehyde tanned pericardium is mounted on a stent requiring no suturing. Between March 1994 and December 1996, 87 patients, 44/43 M/F and aged 70 +/- 6 years had AVR for aortic stenosis (80%), aortic insufficiency (6%) and combined lesions (14%), one patient suffered from endocarditis. Additional coronary artery bypass was done in 25%, aortic root enlargement in 7%. Aortic cross clamp and cardiopulmonary bypass times were 69 +/- 21 and 93 +/- 29 min. All patients were followed by clinical examination and color flow Doppler echocardiography in 3-12 months interval. Follow up was 99% complete. RESULTS: There were five perioperative deaths (6%), none of them valve related. Eighty-one patients were followed up to a period of 52 months (mean interval 37.5 +/- 1.3 months), one patient was lost for follow up. Overall survival was 86, 81, 79 and 71% at 12, 24, 36 and 48 months, respectively. There were 14 late deaths with eight (10%) valve related (four cerebral deaths, four sudden deaths). Sixteen patients (20%) had to be re-operated due to severe valve incompetence. Freedom from reoperation was 98, 97, 90 and 63% at 12, 24, 36, and 48 months, respectively. Valve incompetence occurred suddenly, without previous signs in the follow-up examinations. Selection and preparation of the pericardium, the way of fixation of the tissue--brief immersion in glutaraldehyde--and engineering problems might be responsible for this disastrous outcome. CONCLUSION: Due to these results we must state, that the ATCV did not fulfill our expectations and presently we can not recommend it as an aortic valve substitute.

Aged↗
PubMed1999

Noninvasive monitoring of peak filling rate with acoustic quantification echocardiography accurately detects acute cardiac allograft rejection.

BACKGROUND: Acute cardiac allograft rejection is associated with early diastolic dysfunction. The development of chronic rejection is dependent on the frequency and severity of acute rejection episodes. Therefore, early diagnosis and therapy influence long-term survival significantly. For the first time, acoustic quantification, a new echocardiographic technology for on-line measurement of cardiac volumes and their changes, facilitates quantitative assessment of systolic and diastolic function noninvasively. METHODS: Since May 1996, all consecutive patients after cardiac transplantation (n = 94) underwent 475 endomyocardial biopsies and the same number of echocardiographic studies within 6 hours after biopsy before the histological results were available. RESULTS: Nineteen patients showed 23 episodes of acute rejection (ISHLT > or = 2). There was a significant decrease in left ventricular peak filling rate [PFR: end-diastolic volume (EDV)/ second) as a parameter of diastolic function during rejection (2.9 +/- 0.4, n = 23) as compared to PFR measured under nonrejection status (4.5 +/- 0.8; n = 452; p < 0.0001). Most importantly we found that in these 19 patients showing rejection, the PFR was normal in the last examination before rejection, but was significantly reduced during rejection (2.9 +/- 0.4 vs 4.5 +/- 0.7; n = 23, p < 0.0001). After successful rejection therapy, PFR again normalized in all patients, with the exception of 1 patient with steroid-refractory humoral rejection. We calculated sensitivity and specificity for several cutpoints for the event "first rejection" in 15 patients and plotted them in a receiver operating characteristic curve, showing that a PFR > or = 4.0 EDV/second is never associated with treatable rejection. A decrease of PFR of more than 18% from its prevalue of the last biopsy with no rejection increases the accuracy for the diagnosis of rejection significantly. CONCLUSIONS: We conclude that diastolic dysfunction during acute cardiac allograft rejection can be accurately detected by noninvasive measurement of peak filling rate with acoustic quantification echocardiography. Monitoring of this parameter provides reliable discrimination between treatable and nontreatable rejection.

Acute Disease↗
PubMed1999

Overexpression of Smad2 and colocalization with TGF-beta1 in human pancreatic cancer.

Smad2 belongs to a family of cytoplasmic molecules that are critical components in the transforming growth factor beta (TGF-beta) signaling pathway. Upon ligand binding, the type II TGF-beta receptor (TbetaRII) heterodimerizes with and activates TGF-beta receptor type I (TbetaRI). Activated TbetaRI phosphorylates Smad2, which then heterodimerizes with Smad4, translocates into the nucleus, and subsequently effects gene transcription. Previously we have shown that pancreatic cancers overexpress TGF-betas and TbetaRII. Here, we show by northern blot analysis that Smad2 mRNA levels are significantly increased in pancreatic cancer samples in comparison with normal pancreatic tissues. By immunohistochemistry, Smad2 is present in the cancer cells of 67% of the pancreatic cancer samples. Analysis of serial sections reveals coexpression of Smad2 and TGF-beta1 in the cancer cells. Furthermore, TGF-beta1 increases steady-state levels of Smad2 mRNA in the TGF-beta1-sensitive pancreatic cancer cell line COLO-357. It is suggested that pancreatic cancer cells have the capacity to up-regulate Smad2 expression, which may lead to excessive activation of specific components of the TGF-beta-signaling pathway.

Aged↗
PubMed1999

Coping strategies and behavior problems of urban African-American children: concurrent and longitudinal relationships.

The development and correlates of 82 inner-city African-American children's coping strategies were examined across three years. Results indicated no change in the mean frequency of self-reported coping strategies over the three years, and a significant correlation of emotion-focused strategies with increased self- and mother-reported behavior problems. Child-reported externalizing problems (and, to a lesser degree, internalizing problems) predicted changes in coping strategies across assessments.

Adaptation, Psychological↗
PubMed1999

Personal ammonia sensor for industrial environments.

The realisation of an opto-chemical ammonia sensor suitable for personal monitoring tasks is described, comprising a cyanine dye immobilised in a microporous glass thin film. The fabrication of sensor platforms incorporating embossed grating couplers provides a compact optical design with effective waveguiding characteristics, resulting in reversible ammonia sensitivity in the 5-100 ppm range in under 2 min. Cross-sensitivity of sensor response with water and other potential interferents is considered.

Air Pollution, Indoor↗
PubMed1999

Adenoid cystic carcinoma of Bartholin's gland: what is the optimal approach?

AIMS AND METHODS: We report the case of a locally advanced adenoid cystic carcinoma of Bartholin's gland which required posterior pelvic exenteration, radical vulvectomy and ablation of the ischiorectal fossa in order to obtain tumour clearance with negative margins. Including this case, only three pelvectomies have been performed for this disease. This is the first reported case in which a controlateral unsuspected intravulvar metastasis was found on histology. RESULTS AND CONCLUSIONS: No consensus exists on the adequate surgical management of this particular disease. Nevertheless, a review of the literature and this reported case suggest that radical vulvectomy with negative margins should be preferred to wide local excision as the primary surgical procedure. It also suggests that inguinofemoral lymph-node dissection should only be performed when suspect lymph nodes are found at clinical examination.

Bartholin's Glands↗
PubMed1999

Valve-preserving treatment of Ebstein's anomaly: perioperative and follow-up results.

BACKGROUND: Ebstein's anomaly is a rare congenital cardiac defect of the tricuspid valve (TV) leading to severe tricuspid insufficiency (TI). METHODS: In ten patients, 6 adults (39-53 years) and 4 children (5-10 years), operated between 1989 and 1995 echocardiography was performed pre and post repair and at follow-up. Patients were assessed in our institution at two cut-off points, resulting in a mean first follow-up of 17 +/-15 months and a mean second follow-up of 53+/-23 months. All patients had additional congenital cardiac defects (ASD,VSD). In all patients the TV was repaired by techniques described by Carpentier et al. with some modifications. The goal of this reparative attempt is to mobilize restricted leaflet tissue and aid coaptation through implantation of a ring. RESULTS: Echocardiographically we were able to identify significant characteristics for the successful repair of Ebstein's anomaly. The severity of the disease is represented by the size and function of the right ventricle and the atrialized chamber, the most advanced cases exhibiting a dilated right ventricle with poor contractility. There was severe preoperative TI ( mean grade 3.2 +/- 0.3). Postoperatively TI was significantly reduced to a mean grade of 2+/-0.2. 60% of the patients demonstrated an improvement in the ratio of atrialized chamber to functional right ventricle. Right-ventricular function was improved, the mean score being 2.8+/-0.1. At follow-up I and II right-ventricular function and tricuspid insufficiency was improved in most patients and all patients benefited in quality of life. CONCLUSION: These results suggest that surgical correction should not be delayed until severe right heart failure develops as, particularly in children, good results are achieved, improving the quality of life.

Adult↗
PubMed1999

Women who are HIV infected: the role of religious activity in psychosocial adjustment.

The role of religious activity in the psychosocial adjustment of 205 inner-city African-American women, one-half of whom are HIV infected, was examined. Those who were HIV infected reported praying more but viewed prayer as less effective in coping with a chronic illness. Frequency of prayer predicted optimism about the future, whereas religious activity was not related to current depressive symptoms.

Acquired Immunodeficiency Syndrome↗
PubMed1999

Immunization status of children enrolled in a hospital-based medicaid managed care practice: the importance of the timing of vaccine administration.

OBJECTIVES: To evaluate the immunization status of children enrolled in a hospital-based Medicaid managed care practice and to assess the impact of the timing of vaccine administration on measured immunization rates. DESIGN AND METHODS: The medical records of all children between the ages of 19 and 35 months who were continuously enrolled in the Medicaid managed care practice for the last 6 months of 1996 were reviewed. Immunization status was determined for the following vaccines: diphtheria-tetanus-pertussis/diphtheria-tetanus-acellular pertussis (4 doses); Haemophilus influenzae type b (3 doses); poliovirus (3 doses); hepatitis B (3 doses); measles-mumps-rubella (1 dose); and overall for the basic series. Two assessment methods were used to determine the immunization status of the study children: (1) a count of all documented vaccines ("count"); and (2) only including vaccines that met minimal age and spacing intervals based on American Academy of Pediatrics and CDC recommendations ("interval assessment"). RESULTS: With the count method vaccine-specific immunization rates ranged from 88 to 95%, with overall coverage of 80% for the basic series. With the interval assessment method vaccine-specific immunization rates ranged from 74 to 92%, with overall coverage of 53% for the basic series. CONCLUSIONS: When all documented vaccines were included in the assessment, vaccine-specific immunization rates approached national goals, although overall coverage remained below 90% in this Medicaid managed care practice. The substantially lower immunization rates obtained by the interval assessment method demonstrate the importance of considering the issue of vaccine timing when interpreting immunization rates and the need for policies for revaccinating children who were immunized at less than recommended intervals. The results also have implications for provider education regarding the early administration of vaccines.

Child, Preschool↗
PubMed1999

Effect of protein A immunoadsorption in nephrotic syndrome of various etiologies.

Protein A immunoadsorption (IA) has proved effective in reducing proteinuria in patients with nephrotic syndrome after recurrence of focal and segmental glomerulosclerosis (FSGS) in kidney transplants. The effect of IA in nephrotic syndrome of other etiologies remains unknown. Nine patients with nephrotic syndrome secondary to membranous nephropathy (four cases), diabetes mellitus (one case), IgA nephropathy (two cases), and amyloidosis (two cases) had three to five IA of 2.5 plasma volumes over 4 to 8 d. Patients received no concomitant immunosuppressive treatment, and antihypertensive drugs were left unchanged. Proteinuria decreased from 12.64 +/- 5.49 to 3.35 +/- 2.2 g/24 h (mean +/- SD) in all patients after three to five IA. Hematocrit decreased from 37.32 to 32.64% (12.5% hemodilution) and serum albumin from 25.43 to 18.6 g/L (26.4% decrease). Proteinuria returned to baseline levels within 1 mo, as described in recurrent FSGS following transplantation. When serum albumin balance was controlled by albumin infusion after IA in two patients, comparable decreases in proteinuria were observed. Therefore, IA is effective in producing short-term reduction of proteinuria in nephrotic syndromes related not only to FSGS but also to membranous and IgA nephropathies, diabetes mellitus, and amyloidosis, which suggests that IA removes a nonspecific circulating hemodynamic-altering or permeability-increasing factor.

Amyloidosis↗
PubMed1999

The association between state housing policy and lead poisoning in children.

OBJECTIVES: This study examined the effect of an active program of household lead paint hazard abatement, applied over 22 years, on childhood lead poisoning in Massachusetts. METHODS: A small areas analysis was used to compare screening blood lead levels of children in Worcester County, Mass (n = 27,590), with those in Providence County, RI (n = 19,071). Data were collapsed according to census tract. RESULTS: The percentage of children with lead poisoning (blood lead level > or = 20 micrograms/dL [Pe20]) was, on average, 3 times higher in Providence County census tracts (3.2% vs 0.9% in Worcester County census tracts, P < .0001), despite similar percentages of pre-1950s housing in both counties. The ratio of Pe20 in Providence vs Worcester County census tracts was 2.2 (95% confidence interval = 1.8, 2.7), after adjustment for differences in housing, sociodemographic, and screening characteristics. This estimate was robust to alternative regression methods and sensitivity analyses. CONCLUSIONS: Massachusetts policy, which requires lead paint abatement of children's homes and places liability for lead paint poisoning on property owners, may have substantially reduced childhood lead poisoning in that state.

Child↗