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Biomedical subjects

P Simon

Publications and source records attributed to P Simon.

At least 145 records · Page 8Linked to original sources
PubMed1998

Diagnostic and therapeutic approach of dermoid cysts: retrospective study of 30 cases.

Dermoid cysts are benign tumours affecting young patients that can derive benefits from conservative and minimally invasive surgery. MRI and endovaginal sonogram appear to be useful tools in the pre-operative selection for this surgery. Tumour markers are definitely indicated for postmenopausal patients whereas they appear less useful in young patients. With adequate pre-operative selection, both conservative and minimally invasive surgery can be applied with a clear benefit for the patient.

Adult↗
PubMed1997

Isolation and characterization of a cDNA clone encoding an osmotin-like protein from Arabidopsis thaliana.

A phage library of cDNA from Arabidopsis thaliana has been screened with oligodeoxyribonucleotides designed from regions of high homology found in tobacco osmotin and other osmotin-like proteins. One of the selected clones, Atosm34, presents a 734 bp open reading frame encoding a polypeptide of 244 amino acids, including the putative N-terminal signal and C-terminal propeptide sequences. Comparative alignment reveals extensive homologies to osmotin and the osmotin-like proteins found in Solanaceae, and also to a related polypeptide found in soybean. Genomic hybridization suggests that the cDNA obtained here corresponds to a single copy gene, and RNA blot analysis showed that the level of expression is highest in old leaves.

Amino Acid Sequence↗
PubMed1997

Randomised trial of effect of amiodarone on mortality in patients with left-ventricular dysfunction after recent myocardial infarction: EMIAT. European Myocardial Infarct Amiodarone Trial Investigators.

BACKGROUND: Ventricular arrhythmias are a major cause of death after myocardial infarction, especially in patients with poor left-ventricular function. Previous attempts to identify and suppress arrhythmias with various antiarrhythmic drugs failed to reduce or actually increase mortality. Amiodarone is a powerful antiarrhythmic drug with several potentially beneficial actions, and has shown benefit in several small-scale studies. We postulated that this drug might reduce mortality in patients at high risk of death after myocardial infarction because of impaired ventricular function, irrespective of whether they had ventricular arrhythmias. METHODS: The European Myocardial Infarct Amiodarone Trial (EMIAT) was a randomised double-blind placebo-controlled trial to assess whether amiodarone reduced all-cause mortality (primary endpoint) and cardiac mortality and arrhythmic death (secondary endpoints) in survivors of myocardial infarction with a left-ventricular ejection fraction (LVEF) of 40% or less. Intention-to-treat and on-treatment analyses were done. FINDINGS: EMIAT enrolled 1486 patients (743 in the amiodarone group, 743 in the placebo group). Median follow-up was 21 months. All-cause mortality (103 deaths in the amiodarone group, 102 in the placebo group) and cardiac mortality did not differ between the two groups. However, in the amiodarone group, there was a 35% risk reduction (95% CI 0-58, p = 0.05) in arrhythmic deaths. INTERPRETATION: Our findings do not support the systematic prophylactic use of amiodarone in all patients with depressed left-ventricular function after myocardial infarction. However, the lack of proarrhythmia and the reduction in arrhythmic death support the use of amiodarone in patients for whom antiarrhythmic therapy is indicated.

Aged↗
PubMed1997

Census tract analysis of lead exposure in Rhode Island children.

There has been increasing interest in a targeted approach to the screening and prevention of lead exposure in children. Targeted screening requires an understanding of variation in lead exposure in individual children or by region. In order to better understand variation by region, we studied Rhode Island lead poisoning screening data, examining average lead exposure to children living in 136 Providence County census tracts (CTs). The study population included 17,956 children aged 59 months and under, who were screened between May 1, 1992, and April 30, 1993. We evaluated the relationship between the percentage of children with blood lead > or = 10 micrograms/dL (pe10) and sociodemographic and housing characteristics, derived from United States 1990 Census data, of these CTs. CT descriptors included population density, percentage of households receiving public assistance income, median per capita income, percentage of households female headed, percentage of houses owner occupied, percentage of houses built before 1950, percentage of houses vacant, percentage of population Black, percentage of recent immigrants, and intraurban mobility. On average, 109 children were screened in each census tract; mean screening rate was 44%. There was wide variation in average lead exposure among census tracts, with pe10 ranging from 3 to 60% of screened children (mean 27%). Individual census variables explained between 24 and 67% of the variance in pe10 among CTs. A multiple regression model including percentage screened, percentage of households receiving public assistance, percentage of houses built before 1950, In (percentage of houses vacant), and percentage of recent immigrants explained 83% of variance in pe10. The percentage of houses built before 1950, a variable which models the presence of lead paint in old houses, displayed the largest adjusted effect on pe10 over the range observed for that variable in RI CTs. The percentage of houses vacant was also a highly significant and robust predictor; we suggest that vacancy is an ecological marker for the deterioration of leadbased paint, with higher vacancy neighborhoods containing houses in poorer condition. In Rhode Island, census tracts with high vacancy rates also have high rates of recent immigration, making immigrant groups vulnerable to lead exposure. Small-areas analysis may be useful in directing resources to high risk areas, explaining the sociocultural forces which produce such exposure and analyzing the effects of housing policy over time in states with high screening penetration.

Child, Preschool↗
PubMed1997

The Marchetti bundle nail for femoral shaft fractures: a review of 56 cases.

The aim of this retrospective study of 56 cases was to determine the risks and the limits of the Marchetti bundle nail in the treatment of femoral shaft fractures. According to the AO classification, 25 fractures were in category A, 20 in category B, 7 in category C and 4 were distal metaphysio-diaphyseal fractures with intercondylar separation classified as 33C2. Intraoperative complications were not directly related to the type of nail. Postoperative complications included nonunion, delayed union, malunion such as axial deformity, and shortening. We conclude that the Marchetti bundle nail is a successful method for the treatment of femoral shaft fractures taking into consideration the short operation time, the efficacy of distal locking and the lack of preliminary reaming. Moreover, it is clear that our results were prejudiced due to our learning experience with this new implant. Proximal locking should only be carried out when indicated, in order to prevent delayed union. It may be combined with interfragmental screw fixation, and this is useful in the treatment of complex supracondylar fractures.

Adolescent↗
PubMed1997

The use of profound hypothermia and circulatory arrest in operations on the thoracic aorta.

OBJECTIVE: This retrospective study reviews the contemporary surgical outcome of our patients undergoing operations on thoracic aneurysms in deep hypothermic circulatory arrest. METHODS: Between January 1989 and February 1995, 279 patients were operated on in our institution on various portions of the aorta. In 143 patients (97 male, 46 female), deep hypothermia and circulatory arrest were used as the standard operative technique. Patients age ranged from 16 to 83 years (mean 55). Final indication for operation was dissection Type A in 80 patients (61 acute, 19 chronic), dissection Type B in 21 patients (17 acute, 4 chronic) and atherosclerotic aneurysms in 42 patients (11 acute, 31 chronic). 16 patients were operated under preoperative unstable hemodynamic conditions, 6 patients had been resuscitated preoperatively. Surgical technique included cardiopulmonary bypass with femoral artery cannulation. For added cerebral protection all patients received Cortisone and barbiturates right before circulatory arrest (confirmed by 0-EEG). The segment of the aorta containing the area with the aneurysm, was resected and replaced with a tubular albumin coated graft. RESULTS: The 30-day mortality was 31.15% (19/61) in the acute and 23.52% (4/19) in the chronic type A dissection group, 35.29% (6/17) in the acute and 25% (1/4) in the chronic type B group, 36.3% (4/11) in the acute and 22.58% (7/31) in the chronic atherosclerotic group. Causes of postoperative death in order of frequency were: multiorgan failure (n = 15), myocardial failure (n = 13), bleeding (n = 4), sepsis (n = 4), myocardial infarction (n = 3) and stroke (n = 2). CONCLUSION: Despite rather high mortality rates in the acute aneurysm groups, the technique of profound hypothermic circulatory arrest represents a relatively safe method for operations on the thoracic aorta.

Adolescent↗
PubMed1997

Increased pulmonary flow velocities in oversized homografts in patients after the Ross procedure.

OBJECTIVE: Between September 1991 and July 1996, 60 patients (mean age 29.8 +/- 9 years; range 5-57) underwent aortic root replacement with pulmonary autograft, a viable biologic and nondegenerating substitute. The pulmonary root was replaced with cryopreserved homografts from cardiac transplant recipients. The aim of this study was to evaluate differences in early valve function of viable and cryopreserved allografts. METHODS: All patients had Doppler echocardiographic examinations preoperatively, at discharge from hospital and 54 patients at 1 year follow-up. We measured aortic and pulmonary peak flow velocities with continuous and pulsed-wave Doppler, and graded aortic and pulmonary insufficiency (AI, PI) with color Doppler flow (grade 0-IV). Intraoperatively, the diameters of the pulmonary root and the pulmonary homograft were measured with standard valve probes and matched to body surface area. RESULTS: Pulmonary peak flow velocity (PVmax) increased significantly from preoperative 0.87 +/- 0.11 m/s to 1.30 +/- 0.34 m/s postoperatively (P < 0.001). The implanted homografts (mean 25.9 +/- 2.4 mm) were larger than their native pulmonary diameter (mean 23.3 +/- 1.8 mm) in all patients. Homograft size matched for body surface area (BSA) did not correlate with increased PVmax. There was a significant increase of PVmax at follow-up (FU) since discharge, also (1.83 +/- 0.53 m/s; P < 0.001). Pulsed-wave Doppler demonstrates that increase of PVmax is located directly at the homograft leaflets and not at the anastomoses. Aortic peak flow velocities (AVmax) were normal postoperatively and at FU (post = 1.35 +/- 0.35 m/s; FU = 1.17 +/- 0.27 m/s). There was no significant change in AI or PI since discharge (AI FU = 0.8 +/- 0.4; PI FU = 0.7 +/- 0.5). Eight patients with fever and symptoms diagnosed as post-pericardiotomy syndrome had significantly higher PVmax at FU (PVmax = 2.41 +/- 0.40 m/s; P < 0.02). CONCLUSIONS: The Ross procedure leads to normal AVmax but significant increase of PVmax even in oversized cryopreserved homografts immediately after surgery. Further increase of PVmax without changes in AVmax in the first year demonstrates that changes in flow velocities are valve related and not due to increase in cardiac output. Further investigations will be necessary to determine whether this observation is due to valve rejection or early leaflet degeneration and treatment with immunosuppressive therapy is warranted.

Adult↗
PubMed1997

Frequent reduction or loss of DCC gene expression in human osteosarcoma.

The 'deleted in colon carcinoma' (DCC) gene has been considered a candidate tumour-suppressor gene that encodes for a transmembrane protein with strong structural similarity to members of the superfamily of neural cell adhesion molecules. It has been mapped to the chromosomal region 18q21.1 and it is implicated in cellular differentiation and developmental processes. In human osteosarcoma allelic loss frequently occurs on the long arm of chromosome 18, suggesting a possible involvement of the DCC gene in the pathogenesis of this tumour entity. In the present study the mRNA and protein expression and rearrangements at the DNA level of the DCC gene were addressed in 25 osteosarcomas and several tumour cell lines, including osteosarcoma- and colon carcinoma-derived cell lines. Using an reverse transcriptase polymerase chain reach in (RT-PCR)-based approach DCC expression was found to be lost or substantially reduced in 14 of 19 high-grade osteosarcomas, in three of six lower grade osteosarcomas and most of the tumour cell lines, in contrast to normally differentiated osteoblasts. Immunohistochemical studies on DCC protein expression of 14 selected tumours correlated well with the RT-PCR-based results. In view of the putative tumour-suppressor characteristics of the DCC gene its loss or reduction of expression could be a specific event in the development or progression of many high-grade osteosarcomas.

Adolescent↗
PubMed1997

Autoantibodies against a kidney--liver protein associated with quinolone-induced acute interstitial nephritis or hepatitis.

In the present study we report on four cases of acute interstitial nephritis (AIN) and two cases of hepatitis induced by quinolone. We show by immunoblotting analysis that all sera from these patients contained autoantibodies that recognize a 65-kDa protein expressed in normal human kidney and liver microsomes. Only 6% of sera from healthy individuals who did not ingest quinolone recognized the same protein. These findings suggest that the presence of autoantibodies could be used as a sensitive marker and that a modification of microsomal proteins by quinolone itself or by a metabolite could generated an autoimmune response.

Acute Disease↗
PubMed1996

Cyclosporine may affect improvement of cognitive brain function after successful cardiac transplantation.

BACKGROUND: The effects of cardiac transplantation on cognitive brain function are uncertain. METHODS AND RESULTS: We measured cognitive brain function and quality of life in out-of-hospital cardiac transplant candidates (n = 55; ejection fraction, 19.9%; age, 54.8 years [means]). After transplantation, the patients were serially reevaluated at 4 months (n = 25) and at 12 months (n = 19). Brain function was measured objectively by cognitive P300 evoked potentials. Additionally, standard psychometric tests (Trail Making Test A, Mini-Mental State Examination, and Profile of Mood State test) were performed. Cognitive P300 evoked potentials were impaired in cardiac transplant candidates (359 ms, recorded at vertex) compared with 55 age- and sex-matched healthy subjects (345 ms, P < .01). Trail Making Test A was also abnormal (45 versus 31 seconds in 55 healthy subjects, P < .01). After transplantation, P300 measures were normalized at 4 months (345 ms, P < .05 versus before transplantation) but declined again at 12 months (352 ms, P = NS versus before transplantation). Stepwise multiple regression analysis revealed that cumulative cyclosporine dosage was the only predictor of individual cognitive brain function 4 months (753 mg/kg body wt, P < .05) and 12 months (2006 mg/kg body wt, P < .01) after transplantation, respectively. CONCLUSIONS: Objective cognitive P300 auditory evoked potential measurements indicate that cognitive brain function is significantly impaired in patients suffering from stable end-stage heart failure. Successful cardiac transplantation is effective to fully normalize impaired brain function. Subsequent relative long-term decline of cognitive brain function after successful cardiac transplantation is strongly suggested to be related to cumulative cyclosporine neurotoxicity.

Affect↗
PubMed1996

Capillary electrophoresis and supercritical chromatography, complementary and alternative techniques for the determination of urinary metabolites of styrene.

Two analytical methods without an extraction step were developed using capillary electrophoresis and supercritical fluid chromatography in order to determine phenylglyoxylic (PGA) and mandelic (MA) acids in urine, with minimum treatment and manipulation of biological samples. The urine was diluted ten-fold in acetonitrile and directly injected into the analytical systems after centrifugation. Analysis was performed by capillary electrophoresis on alkyl bonded phase capillary columns with sodium formiate (4 x 10(-2) M)-isopropanol (9:1, v/v) as a buffer, and by supercritical fluid chromatography on a Diol bonded phase silica column with ethanol-water-methanesulphonic acid (97.5:2.4:0.1, v/v) as coeluent of CO2. Detection of PGA and MA was performed by ultraviolet detection at 255 and 210 nm, respectively. The methods are in agreement, and are easily able to detect 5 mg/g creatinine for PGA, and 15 mg/g creatinine for MA, which are one twentieth of the lowest biological exposure index values.

Air Pollutants, Occupational↗
PubMed1996

Evidence for recent growth of the HIV epidemic among African-American men and younger male cohorts in Los Angeles County.

To estimate the recent course of the human immunodeficiency virus type 1 (HIV) epidemic among men within birth cohorts, ethnic groups, and HIV-risk groups in Los Angeles County, backcalculation methods were combined with log-linear models and census data to reconstruct HIV incidence in subgroups from AIDS surveillance data. Results were compared with directly measured HIV seroprevalence in public sexually transmitted disease (STD) clinics in Los Angeles. Models of HIV incidence indicate that the initial epidemic pattern among men who have sex with men, including a decline in incidence since the mid-1980s, does not apply to all post-1960 birth cohorts. Later peaks were observed in younger birth cohorts and among injection drug users, especially among African-American men, with no evidence of a peak before the 1990s among men born after 1960. Our results indicate that HIV continued to spread near peak rates into the 1990s among younger birth cohorts, especially among young African-American men who have sex with men. Because of the lengthy incubation period from HIV infection to AIDS incidence, our results imply that the AIDS epidemic has not yet peaked in these cohorts and may continue to grow through the present decade in several subgroups. The large variation in HIV incidence and prevalence across birth cohorts and other subgroups needs to be addressed in future community intervention plans.

Adolescent↗
PubMed1996

Outdoor experimental ponds (mesocosms) designed for long-term ecotoxicological studies in aquatic environment.

Outdoor artificial ponds (mesocosms) of 12 m3 were designed for long-term ecotoxicological studies. Sediment, macrophytes (Typha angustifolia and Elodea canadensis), and free and caged freshwater snails [Lymnaea palustris (Müller)] and wood lice (Asellus aquaticus L.) were collected in nearby natural ecosystems and introduced in the mesocosms. Sixty goldfish (Carassius auratus L.) were caged in each pond. Introduced species developed and reproduced in every mesocosm. Animal species (mainly insects and amphibians) spontaneously colonized the ponds, developed, and reproduced. The resulting communities qualitatively resemble those living in natural lentic systems in the surrounding area. Homogenity in physical and chemical conditions and in abundance of phytoplanktonic, periphytic, and macroinvertebrate communities between the different mesocosms was assessed during the stabilization period (8 months). Except for periphyton biomass, no divergent evolution was observed between the ponds. Mesocosm water was slightly eutrophic, alkaline (mean pH: 8.47 +/- 0.09), and moderately hard and mineralized. The homogenous and realistic environmental conditions and high ecological representativity of the outdoor experimental ponds were suitable for extensive ecotoxicological studies. Considerations on the choice and origin of introduced species and on possible interactive effects of the transfer of organisms from natural environments, maintainance conditions, and pollutant exposure are discussed.

Animals↗