Interaction between smoking and glutathione S-transferase polymorphisms in solvent-induced chronic toxic encephalopathy

Exposure to organic solvents is still common in industrial and other work environments, and increases the risk of chronic toxic encephalopathy (CTE). Genetic variation in metabolic enzymes for solvents and other xenobiotics may modify the risk of developing toxic effects. Therefore, we investigated the presence of null genotypes for glutathione S-transferases M1 and T1 (GSTM1, GSTT1) and two genetic polymorphisms of microsomal epoxide hydrolase (mEPHX) in relation to the risk for chronic toxic encephalopathy (CTE) when exposed to solvents and smoking. We genotyped 115 patients who were classified into three categories: CTE (n = 56), incipient CTE (n = 27) and non-CTE (n = 32) patients. DNA was isolated from leucocytes and the GSTM1 and GSTT1 null genotypes were determined by multiplex-polymerase chain reaction. The two polymorphisms of mEPHX were analysed by PCR-RFLP (restriction fragment length polymorphism) based assays. All analyses were performed blindly with regard to both exposure and disease status. An increased binomial regression risk ratio = 2.5, 95% confidence interval (CI) 1.5-4.2, of the GSTM1 null genotype for CTE was found in smokers and for the GSTT1 null genotype (binomial regression risk ratio 1.5, 95% CI 1.0-2.0). In nonsmokers, the GSTM1 null genotype did not confer any risk for CTE. None of the studied mEPHX polymorphisms were associated with an increased risk for CTE. We suggest that the GSTM1 null genotype in smokers is a possible risk for solvent-induced CTE.     

Putative role of 67 kDa elastin-laminin receptor in tumor invasion

Cellular regulatory mechanisms normally maintain a delicate balance between cell proliferation, quiescence and death. The imbalance between these functions resulting from molecular intracellular changes is a key factor in tumorigenesis. Tumor cells detaching from the primary tumor possess a propension for invasion and metastasis formation. These tumor cells can attach, migrate, proliferate and grow in host tissue. The surrounding extracellular matrix (ECM) modulates these functions. It is now widely accepted that cell-matrix interactions play an important role in these processes. Most investigators concentrated their attention on the role of integrins in the above processes. There are, however, only scant data on the role of elastin and its receptors in tumor invasion. Nevertheless, experimental evidence indicates that the 67 kDa elastin-laminin receptor (ELR) subunit plays an important role in tumor invasion by mediating essential tumor cell functions leading to metastases. In this review we will concentrate on the putative role of the 67 kDa ELR subunit in tumor invasion.     

Treatment of subclavian-axillary vein thrombosis: long-term outcome of anticoagulation versus systemic thrombolysis

Objective: To investigate long-term clinical and morphological outcome of patients with subclavian–axillary vein thrombosis treated with systemic thrombolysis compared to anticoagulation in a retrospective, nonrandomised study. Methods: We studied 95 consecutive inpatients with subclavian–axillary vein thrombosis treated either with systemic urokinase thrombolysis and subsequent oral anticoagulation (n=33) or with anticoagulation only (n=62). Anticoagulation was performed with heparin and phenprocoumon. Patients were followed for median 40 months (IQR 14 to 94) for symptomatic upper extremity post-thrombotic syndrome and for venous recanalisation by duplex ultrasound. Results: Primary technical success rate of the systemic thrombolysis was 88% (n=29) with seven peri-intervention bleeding complications (21%). No complication was observed in patients with anticoagulation only (p<0.0001). At the time of follow-up, duplex sonography showed a thrombotic subclavian vein in 40 of 83 patients (48%), but only 9 of 95 patients (10%) had a symptomatic upper extremity post-thrombotic syndrome. Patients with systemic thrombolysis exhibited a 60% adjusted reduced risk for a thrombotic subclavian vein at the time of follow-up compared to patients with anticoagulation only (95% CI: 0.2 to 0.9, p=0.03). However, the frequency of symptomatic post-thrombotic syndrome after thrombolysis and anticoagulation was similar (adjusted p=0.6). Conclusion: Systemic thrombolysis of subclavian–axillary vein thrombosis has an acceptable primary technical success rate and improves venous recanalisation rates compared to anticoagulation. However, the high rate of complications during thrombolysis and the lack of clinical benefit suggest that conservative treatment may be favoured.     

Inflammatory response to stent implantation: differences in femoropopliteal,iliac, and carotid arteries

PURPOSE: To examine how frequently Breast Imaging Reporting and Data System (BI-RADS) mammographic screening assessments were associated with expected clinical management recommendations. MATERIALS AND METHODS: Seven Breast Cancer Surveillance Consortium mammography registries recorded screening assessments and recommendations in 1997 to identify the proportion of women in each BI-RADS category. The first screening assessment for a woman without cancer or a prior mammogram within 9 months was associated with its independently recorded recommendation. RESULTS: Among 292,795 women, screening assessments included 269,022 (91.9%) with a "negative" or "benign finding," and 267,103 (99.3%) of these women were recommended for normal interval follow-up. Among 11,861 (4.1%) women with screening assessments of "probably benign finding," 4,782 (40.3%) were recommended for short interval follow-up as expected on the basis of the BI-RADS, but a high proportion (36.9%) were recommended for additional imaging. Among 1,625 (0.6%) women with "suspicious abnormality," most were recommended for biopsy (48.7%) or clinical examination and/or surgical consult (9.0%), but many were recommended for additional imaging (38.7%). Among 243 (0.1%) women with screening assessments "highly suggestive of malignancy," a majority were recommended for biopsy (73.3%) or clinical examination and/or surgical consult (18.1%) consistent with BI-RADS, but some were recommended for additional imaging (6.6%). CONCLUSION: BI-RADS assessments and management recommendations are consistent for negative and benign assessments, but inconsistencies were found in assessments and recommendations for mammographic abnormalities.     

B-flow evaluation of carotid arterial stenosis: initial experience

In this prospective pilot trial, B-flow ultrasonographic (US) imaging was compared with color duplex flow US in the evaluation of internal carotid arterial stenosis. Despite almost excellent interobserver variability, none of the investigated B-flow imaging parameters correlated with those of duplex US. In conclusion, the investigated B-flow imaging parameters cannot be used in evaluating internal carotid arterial stenosis.     

Predictors of long-term results after treatment of iliac artery obliteration by transluminal angioplasty and stent deployment

Purpose: To investigate initial and long-term success rate after percutaneous treatment of iliac artery occlusion with angioplasty and stent deployment. To investigate the influence of vascular comorbidity, lesion length, stent placement and lesion coverage as possible predictors of outcome. Methods: Between January 1994 and December 1999, 80 iliac recanalizations were performed on 78 patients, median age 61.1 ± 11.5 (SD) years. All patients were followed up by clinical examinations, duplex ultrasound and intravenous digital subtraction angiography. Mean follow-up time was 2.0 ± 1.53 (SD) years. Multivariate Cox regression analysis was used to determine the influence of cofactors on patency. Results: One, 2 and 4 years after recanalization, primary patency was 78.1%, 74.5% and 64.0%; secondary patency was 88.8%, 88.8% and 77.9%, respectively. Patients with shorter occlusions, complete lesion coverage and patent ipsilateral femoral arteries had significantly longer patency rates. Complications included inguinal hematoma (n=1), technical failure (n=3) aortic dissection (n=1), embolic occlusions (n=7), gluteal claudication (n=1) and genital necrosis after subsequent urethral surgery in one patient with contralateral occlusion and ipsilateral overstenting of the internal iliac artery with subsequent stenosis. Complications were of permanent clinical significance in seven of 78 (9%) of the patients. In 17 (22%) cases, percutaneous reintervention was performed with angioplasty in the stent (n=16) or deployment of a new stent (n=1). Conclusion: Endoluminal stent placement has its place in an interdisciplinary therapeutic approach as a viable therapeutic alternative to major transabdominal bypass surgery and can be performed with comparable complication rates. Patients with short occlusions, patent femoral arteries, and stents covering the entire occlusion have significant longer patency.     

Melatonin improves sleep quality of patients with chronic schizophrenia

BACKGROUND: Accumulating evidence indicates decreased melatonin levels in patients with schizophrenia. Insomnia, mainly difficulty in falling asleep at night, is commonly reported in this population. Association of insomnia with low or abnormal melatonin rhythms has been repeatedly documented. Melatonin is an endogenous sleep promoter in humans. We hypothesized that insomnia in patients with schizophrenia may be partially due to diminished melatonin output. In this study, we measured melatonin output in patients with chronic schizophrenia and assessed the effects of melatonin replacement on their sleep quality. METHOD: In a randomized, double-blind, cross-over, clinically based trial, 19 patients with DSM-IV schizophrenia who were treated with the normal treatment regimen were given melatonin (2 mg, controlled release) or placebo for 2 treatment periods of 3 weeks each with 1 week washout between treatment periods (7 weeks total). For measuring endogenous melatonin production, urine was collected from each patient every 3 hours between 9:00 p.m. and 9:00 a.m. Actigraphy was performed for 3 consecutive nights at the end of each period. Activity- and rest-derived sleep parameters were compared for the whole population with treatment arm as the intervening variable. A separate analysis was performed for patients subgrouped into high versus low sleep efficiency. RESULTS: All patients had low melatonin output. Melatonin replacement significantly improved rest-derived sleep efficiency compared with placebo (83.5% vs. 78.2%, p = .038) in this population. Improvement of sleep efficiency was significantly greater (p < .0014) in low-efficiency (80% vs. 67%) than high-efficiency sleepers (88% vs. 90%). In addition, during melatonin therapy, tendencies toward shortened sleep latency (by 40 minutes, p < .056) and increased sleep duration (by 45 minutes, p < .078) were observed in low- but not high-efficiency sleepers. CONCLUSION: Melatonin improves sleep efficiency in patients with schizophrenia whose sleep quality is low.     

The effects of 1.5T magnetic resonance imaging on early murine in-vitro embryo development

Although no ionizing radiation is involved, patients undergoing magnetic resonance imaging (MRI) are exposed to powerful static magnetic fields, magnetic field gradients, and radio-frequency fields that may be potentially damaging. Our study aims to document the effect of MRI imaging sequences on early murine embryo development (two-cell to blastocyst stage) in vitro. Two-cell murine embryos were exposed to various lengths of MRI using pulse sequences employed in present day clinical imaging. Early murine embryo development was documented in vitro, and blastocyst development rates were computed for both the control and exposed groups. There were no significant differences detected in the rate of blastocyst formation between the control groups and the embryos exposed to MRI.     

The costs of cardiorespiratory disease episodes in a study of emergency department use

OBJECTIVE: The average per person direct cost of illness of cardiorespiratory disease episodes was estimated based on a prospective study of emergency department visits. METHODS: Economic modelling of health care costs using prospectively collected resource utilization data (9/1/94 to 8/31/95) from hospital emergency department visitors assigned a diagnosis of asthma, chronic obstructive pulmonary disease (COPD), respiratory infections or cardiac conditions. RESULTS: The total direct costs (1997 CDN$) [95% C.I.] per patient were $1,043.55 [$922.65, $1,164.47] for asthma, $1,690.11 [$1,276.92, $2,103.30] for COPD, $676.50 [$574.46, $778.54] for respiratory infections, and $3,318.74 [$2,937.72, $3,699.76] for cardiac conditions. CONCLUSIONS: This study showed that on average, patients diagnosed with a cardiac condition had the highest total direct cost. Hospitalization cost was the largest component of costs for all diagnoses except asthma, for which medications were the single largest component of direct costs.     

Binaural sensitivity to temporal fine structure and lateralization ability in children with suspected (central) auditory processing disorder

Objective

Previous studies have shown that a subgroup of children with suspected (central) auditory processing disorder (SusCAPD) have insufficient ability to use binaural cues to benefit from spatial processing. Thus, they experience considerable listening difficulties in challenging auditory environments, such as classrooms. Some researchers have also indicated the probable role of binaural temporal fine structure (TFS) in the perceptual segregation of target signal from noise and hence in speech perception in noise. Therefore, in the present study, in order to further investigate the underlying reason for listening problems against background noise in this group of children, their performance was measured using binaural TFS sensitivity test (TFS-LF) as well as behavioral auditory lateralization in noise test, both of which are based on binaural temporal cues processing.