Dissipation and effects of chlortetracycline and tylosin in two agricultural soils: a field-scale study in southern Denmark

Presently, there is a basic lack of information concerning the accumulation of antibacterial agent residues in agricultural soils. In this field study, performed in southern Denmark, we assess the dissipation of chlortetracycline (CTC), and tylosin A (TYL A) as a function of time. Field soils were classified as a sandy loam soil (field A) and a sandy soil (field B) and each field was sampled on six occasions during the 155-d experimental period from May to October 2000 for chemical analysis and counts of colony-forming units (CFU) detecting the level of aerobic bacteria surviving antibiotic exposure. Colony-forming units and TYL A were detected throughout the entire sampling period, with respective starting soil concentrations of 30 and 50 microg kg(-1) soil declining to 1 and 5 microg kg(-1) soil, on day 155. Compound half-lives (95% confidence limits in parentheses) were estimated for both fields and T1/2 for CTC was 25 d (20-34) and 34 d (28-42) in fields A and B, respectively, and T1/2 for TYL A was 67 d (54-86) and 49 d (40-64) in fields A and B, respectively. No significant difference was determined between compound half-lives on the two fields. The level of aerobic antibiotic-resistant bacteria in the soil over time and soil fauna community was assessed in relation to application of manure containing antibacterial agents to the agricultural fields. The level of both CTC- and TYL-resistant bacteria was affected in the soil by amendment of manure, but declined during the study to the same level as observed at the beginning.     

Monitoring of trace elements in breast milk sampling and measurement procedures

The aims of this study were to test analytical procedures for the determination of Cd, Cu, Mn, Pb, Se and Zn in breast milk and to establish optimum sampling conditions for monitoring purposes. Two population groups were analysed: (1) Seven women from Prague whose breast milk was sampled on days 1,2, 3, 4, 10, 20 and 30 after delivery; (2) 200 women from four (two industrial and two rural) regions whose breast milk was sampled at defined intervals. All samples were mineralised in a microwave oven in the mixture of HNO3 + H2O2 and analysed by atomic absorption spectrometry. Conditions for the measurement of the elements under study (i.e. those for the electrothermal atomisation for Cd, Mn and Pb, flame technique for Cu and Zn, and hydride generation technique for Se) were optimized. Using optimized parameters the analysis was performed and the following conclusion has been made: the concentrations of zinc and manganese decreased very sharply over the first days, that of copper slightly increased within the first two days and then slightly decreased, that of selenium did not change significantly. Partial "stabilisation" was achieved after the second decade. No correlation among the elements was found. A significant difference between whole and skim milk was only found for selenium (26% rel. higher in whole milk). The majority concentrations of cadmium and lead were below the detection limit of the method (0.3 microg x l(-1) and 8.2 microg x l(-1), respectively, as calculated for the original sample). To provide biological monitoring, the maintenance of sampling conditions and especially the time of sampling is crucial.     

Messsystem zur Erfassung der „binaural masking level difference“ (BMLD) bei Kindern

BACKGROUND: The binaural masking level difference (BMLD) is defined as the contrast between homophasic and antiphasic signal conditions, and can be regarded as a measure for noise suppression by the auditory system. METHODS: An adaptive two interval forced choice (IFC) measurement method was designed to assess BMLDs in children. The target tone was a 500 Hz sine pip which was masked with narrow band noise. The presentation of homo- and antiphasic signals was staggered in order to take into account artefacts--such as changes in vigilance--in a similar manner for both conditions. RESULTS: Measurement was feasible in 57 out of 85 children (6-14 y.) with suspected auditory processing disorders. Mean BMLD was 7.4(+/-4.5 SD) dB. Five children revealed a BMLD close to 0 dB suggesting that they had no advantage in signal detection for the antiphasic condition. Eleven children were not able to cope with the task of measurement. In another 17 children, the measurements did not converge to a stable threshold. DISCUSSION: The proposed measurement method was feasible with most of the children. With slight modifications of the threshold convergence, this proportion can be further increased. Whether or not the large inter-individual scatter of the results is an expression of the heterogeneous clinical clientele can only be determined when normative data are available.     

(11)C]MADAM, a new serotonin transporter radioligand characterized in the monkey brain by PET

The aim of this study was to explore the potential of a new selective serotonin transporter (5-HTT) inhibitor, N,N-dimethyl-2-(2-amino-4-methylphenylthio)benzylamine (MADAM, K(i)=1.65 nM), as a PET radioligand for examination of 5-HTT in the nonhuman primate brain. MADAM was radiolabeled by an N-methylation reaction using [(11)C]methyl triflate and the binding was characterized by PET in four cynomolgus monkeys. Metabolite levels in plasma were measured by gradient high-performance liquid chromatography (HPLC). The radiochemical incorporation yield of [(11)C]MADAM was 75-80% and the specific radioactivity at the time of administration was 34-652 GBq/micromol (n=8). The highest uptake of radioactivity was observed in striatum, thalamus, mesencephalon, and the lower brainstem. Lower binding was detected in neocortex and the lowest radioactive uptake was found in the cerebellum. This distribution is in accordance with the known expression of 5-HTT in vitro. The fraction of the total radioactivity in monkey plasma representing unchanged [(11)C]MADAM was 20% at 45 min after injection, as measured by gradient HPLC. Pretreatment measurements, using unlabeled citalopram, GBR 12909, and maprotiline, as well as a displacement measurement, using unlabeled MADAM, confirmed that [(11)C]MADAM binds selectively and reversibly to 5-HTT, and support the use of the cerebellum as reference region. The present characterization of binding in the monkey brain suggests that [(11)C]MADAM is a potential PET radioligand for quantitative studies of 5-HTT binding in the human brain.     

Sagittal abdominal diameter is a strong anthropometric marker of insulin resistance and hyperproinsulinemia in obese men

OBJECTIVE: It is clinically important to find noninvasive markers of insulin resistance and hyperproinsulinemia because they both predict cardiovascular and diabetes risk. Sagittal abdominal diameter (SAD) or "supine abdominal height" is a simple anthropometric measure previously shown to predict mortality in men, but its association with insulin resistance and hyperproinsulinemia is unknown. RESEARCH DESIGN AND METHODS: In a common high-risk group of 59 moderately obese men (aged 35-65 years, BMI 32.6 +/- 2.3 kg/m(2)), we determined anthropometry (SAD, BMI, waist girth, and waist-to-hip ratio [WHR]); insulin sensitivity (euglycemic-hyperinsulinemic clamp); and plasma concentrations of intact proinsulin, specific insulin, C-peptide, glucose, and serum IGF binding protein-1 (IGFBP-1). To compare SAD with other anthropometric measures, univariate and multiple regression analyses were used to determine correlations between anthropometric and metabolic variables. RESULTS: SAD showed stronger correlations to all measured metabolic variables, including insulin sensitivity, than BMI, waist girth, and WHR. SAD explained the largest degree of variation in insulin sensitivity (R(2) = 0.38, P < 0.0001) compared with other anthropometric measures. In multiple regression analyses, including all anthropometric measures, SAD was the only independent anthropometric predictor of insulin resistance (P < 0.001) and hyperproinsulinemia (P < 0.001). CONCLUSIONS: In obese men, SAD seems to be a better correlate of insulin resistance and hyperproinsulinemia (i.e., cardiovascular risk) than other anthropometric measures. In overweight and obese individuals, SAD could represent a simple, cheap, and noninvasive tool that could identify the most insulin resistant in both the clinic and clinical trials evaluating insulin sensitizers. These results need confirmation in larger studies that also include women and lean subjects.     

Endoscopic stapling diverticulostomy for Zenker diverticulum

INTRODUCTION: The authors have successfully applied the endoscopic stapling diverticulostomy for three patients with symptomatic Zenker diverticulum. METHOD: Under light general anesthesia the hypopharynx was explored with a rigid, double lipped laryngoscope (Weerda, Storz). The common wall between the esophagus and and diverticulum was cut across and reunited with a endosurgical stapler. RESULTS: Operating time was 25 minutes in average. There were no intraoperative or postoperative complications. The oral feeding was started on the 2. postoperative day. The patients were symptom-free and they were discharged on the fifth postoperative day. The preoperative symptoms were not reported at follow-up assessment. CONCLUSION: The endoscopic stapler diverticulostomy offers distinct advantages, including brief operative time, short hospitalization, reduced morbidity, early oral feeding and predictable resolution of symptoms. The authors proposed the technique in the treatment of the patients with Zenker's diverticulum especially for elderly cases with diverticulum larger than 3 cm.     

Epidemiologic indices of cervical cancer morbidity in areas with various levels of industrial pollution

While general cervical carcinoma morbidity is on the decline in most of the surveyed Russian Federation areas characterized by varying levels of industrial pollution, the heavily industrialized region of Salavat revealed a different tendency. Its level was 1.6 times (p<0.05) those in other areas. That was due to the morbidity of women aged 40-69 and even 20-29 and 30-39 years.