ABSTRACT
A recent paper by Miszczak et al. (2020) examines metal contamination of mires in Poland and Norway. The authors conclude that lead (Pb) records in ombrotrophic peatlands cannot be used to reconstruct the chronological history of anthropogenic activities due to post-depositional mobility of the metal. We contest this general conclusion which stands in contrast with a significant body of literature demonstrating that Pb is largely immobile in the vast majority of ombrotrophic peatlands. Our aim is to reaffirm the crucial contribution that peat records have made to our knowledge of atmospheric Pb contamination. In addition, we reiterate the necessity of following established protocols to produce reliable records of anthropogenic Pb contamination in environmental archives.
ABSTRACT
The accumulation rates of atmospheric Pb and Ti were obtained using the production rates of Sphagnum mosses collected in four ombrotrophic bogs from two regions of southern Germany: Upper Bavaria (Oberbayern, OB) and the Northern Black Forest (Nordschwarzwald, NBF). Surfaces of Sphagnum carpets were marked with plastic mesh and one year later the production of plant matter was harvested. Metal concentrations were determined in acid digests using sector field ICP-MS employing well established analytical procedures. Up to 12 samples (40 x 40 cm) were collected per site, and 6-10 sites were investigated per bog. Variations within a given sampling site were in the range 2.3-4x for Pb concentrations, 1.8-2.5x for Ti concentrations, 3-8.3x for Pb/Ti, 5.6-7.8x for Pb accumulation rates, and 2.3-6.4x for Ti accumulation rates. However, the median values of these parameters for the sites (6-10 per bog) were quite consistent. The mosses from the bogs in NBF exhibited significantly greater productivity (187-202 g m(-2) a(-1)) compared to the OB peat bogs (71-91 g m(-2) a(-1)), and these differences had a pronounced effect on the Pb and Ti accumulation rates. Highly productive mosses showed no indication of a "dilution effect" of Pb or Ti concentrations, suggesting that more productive plants were simply able to accumulate more particles from the air. The median rates of net Pb accumulation by the mosses are in excellent agreement with the fluxes obtained by direct atmospheric measurements at nearby monitoring stations in both regions (EMEP and MAPESI data).
Subject(s)
Air Pollutants/metabolism , Lead/metabolism , Sphagnopsida/growth & development , Sphagnopsida/metabolism , Titanium/metabolism , Air Pollutants/chemistry , Atmosphere , Biodegradation, Environmental , Lead/chemistry , Sphagnopsida/chemistry , Titanium/chemistryABSTRACT
Concentrations of 3alpha-reduced neuroactive steroids are altered in depression and normalize after antidepressant pharmacotherapy with selective serotonin re-uptake inhibitors (SSRIs). We investigated the impact of mirtazapine on the activity of a key neurosteroidogenic enzyme, the 3alpha-hydroxysteroid dehydrogenase (3alpha-HSD), and on the levels of neuroactive steroids in relation to clinical response. A total of 23 drug-free in-patients suffering from a major depressive episode (DSM-IV criteria) underwent 5-week treatment with mirtazapine (45 mg/day). Plasma samples were taken weekly at 0800 and quantified for neuroactive steroids by means of combined gas chromatography/mass spectrometry analysis. Enzyme activity was determined by assessment of steroid conversion rates. Irrespective of clinical outcome, there were significant increases in 3alpha,5alpha-tetrahydroprogesterone, 3alpha,5beta-tetrahydroprogesterone, 5alpha-dihydroprogesterone, and 5beta-dihydroprogesterone after mirtazapine treatment, whereas 3beta,5alpha-tetrahydroprogesterone levels were significantly decreased. In vitro investigations demonstrated a dose-dependent inhibitory effect of mirtazapine on the activity of the microsomal 3alpha-HSD in the oxidative direction (conversion of 3alpha,5alpha-tetrahydroprogesterone to 5alpha-dihydroprogesterone). Mirtazapine affects neuroactive steroid composition similarly as do SSRIs. The inhibition of the oxidative pathway catalyzed by the microsomal 3alpha-HSD is compatible with an enhanced formation of 3alpha-reduced neuroactive steroids. However, the changes in neuroactive steroid concentrations more likely reflect direct pharmacological effects of this antidepressant rather than clinical improvement in general.
Subject(s)
3-alpha-Hydroxysteroid Dehydrogenase (B-Specific)/metabolism , Antidepressive Agents, Tricyclic/pharmacology , Depressive Disorder/blood , Mianserin/analogs & derivatives , Steroids/blood , Adult , Aged , Female , Gas Chromatography-Mass Spectrometry , Humans , Male , Mianserin/pharmacology , Middle Aged , Mirtazapine , Treatment OutcomeABSTRACT
A case of nonsecretory multiple myeloma is presented. Radiological findings and bone marrow examination provided the diagnosis. Bone scintigraphy showed metastatic pulmonary calcification, thus demonstrating the potential superiority to any other routine diagnostic modality in detection of visceral calcification.
Subject(s)
Calcinosis/diagnostic imaging , Lung Neoplasms/secondary , Multiple Myeloma/diagnosis , Adult , Biopsy , Bone Marrow/pathology , Humans , Lung Neoplasms/diagnosis , Male , Multiple Myeloma/diagnostic imaging , Multiple Myeloma/pathology , Radiography , Radionuclide Imaging , Technetium Tc 99m MedronateABSTRACT
In 110 patients with signs of cerebral infarct computed tomography (CT) and intravenous digital subtraction angiography (DSA) were performed. With DSA 63 arterial wall lesions could be seen, in CT 27 infarcts were found. In 9 examinations DSA was not diagnostic. Combination of both methods makes it possible to relate vascular lesions with size and localisation of cerebral infarcts.
Subject(s)
Cerebrovascular Disorders/diagnostic imaging , Subtraction Technique , Tomography, X-Ray Computed , Aged , Cerebral Angiography/methods , Cerebral Infarction/diagnostic imaging , Diagnosis, Differential , Female , Humans , Male , Middle AgedABSTRACT
Intravenous digital subtraction angiography (DSA) and 131J-hippuran clearance (NSS) were evaluated in 113 patients, both methods were made as screening tests for renovascular hypertension. In 9 examinations DSA was not diagnostic, in 18 patients arterial wall lesions were found. The dynamic renal imaging with hippuran showed alterations in 86 patients, 2 patients with renal arterial stenosis had normal findings. Combination of both methods yields good results in estimation of the haemodynamic significance of a renal arterial narrowing.
Subject(s)
Hypertension, Renovascular/diagnosis , Radioisotope Renography , Renal Artery/diagnostic imaging , Renal Veins/diagnostic imaging , Subtraction Technique , Adult , Evaluation Studies as Topic , Female , Humans , Iodohippuric Acid , Male , Middle Aged , Radiography , Renal Artery Obstruction/diagnosisABSTRACT
Venous digital subtraction angiography was performed in 248 patients for the diagnosis of renal arterial stenosis. In 88% of the investigations the digital subtraction angiograms were of diagnostic value. Comparison of digital angiography and conventional angiography was made for 57 renal arteries (25 investigations). In 52 renal arteries we found the same results with both methods, in 5 renal arteries the digital angiography showed false positive results. The spatial resolution of digital subtraction angiography is sufficient for the correct diagnosis of significant renal arterial stenosis. With regard to the lower invasion of digital subtraction angiography compared to conventional angiography the first method should be used for clarification of renal arterial hypertension.
Subject(s)
Angiography/methods , Hypertension, Renovascular/diagnostic imaging , Renal Artery Obstruction/diagnostic imaging , Subtraction Technique , Contrast Media/administration & dosage , Humans , Injections, Intravenous , Middle AgedABSTRACT
Intravenous digital subtraction angiography has been employed to examine arteries in 600 patients. Conventional angiography was used in 41 cases where insufficient DSA was made, or as definitive preoperative investigation. In 88% the digital subtraction angiogram is diagnostic, and conventional angiography then shows little more additional information.
Subject(s)
Angiography/methods , Subtraction Technique , Carotid Artery, Internal/diagnostic imaging , Constriction, Pathologic , Humans , Iliac Artery/diagnostic imaging , Middle Aged , Renal Artery Obstruction/diagnostic imagingABSTRACT
Intravenous digital subtraction angiography (DSA) was obtained in 55 cases after reconstructive procedures of the carotid arteries, the pelvic and lower limb arteries. In 48 cases (87%) the studies were of technically satisfactory or good quality. On DSA 32 vascular reconstructions were normal and 16 had typical complications like occlusions, stenoses, aneurysms and insufficient run-off. -Experience indicates that the spatial resolution of DSA is adequate for clinical purposes such as determining graft patency or the presence of postoperative complications. Because DSA is less invasive than catheter angiography, postoperative evaluation of patients having undergone peripheral surgical revascularization should start with DSA.
Subject(s)
Angiography/methods , Arterial Occlusive Diseases/diagnostic imaging , Subtraction Technique , Aged , Aorta/surgery , Arterial Occlusive Diseases/surgery , Female , Femoral Artery/surgery , Humans , Iliac Artery/surgery , Intermittent Claudication/diagnostic imaging , Intermittent Claudication/surgery , Leriche Syndrome/diagnostic imaging , Leriche Syndrome/surgery , Male , Middle AgedSubject(s)
Hypertension, Renovascular/diagnostic imaging , Renal Artery/diagnostic imaging , Subtraction Technique , Adolescent , Adult , Aged , Female , Humans , Male , Middle Aged , RadiographyABSTRACT
We studied 46 patients with a history of transmural myocardial infarction or angiographic evidence of coronary artery stenosis with both conventional contrast ventriculography and digital subtraction ventriculography from May to September 1982. Urografin 76, 30 ml, was administered at a flow rate of 18 ml/s, by means of a catheter in the superior vena cava during digital subtraction ventriculography (DSV). Results of the latter were compared with conventional contrast ventriculograms. The correlation coefficient was r =0.938 (p less than 0.001) for determination of ejection fraction with both methods. The data in individual cases suggest that DSV is more sensitive than conventional contrast ventriculography in determination of severely reduced ejection fractions. The methods are practically identical in qualitative evaluation of disorders of regional wall motion in the anterolateral region, while DSV is more sensitive than conventional ventriculography in evaluating the apical region. Sensitivity was 85.7% when the two methods were compared in evaluation of the inferior region of the left ventricle. Both methods are identical in demonstration of severely deformed ventricles. Digital subtraction ventriculography may replace conventional contrast ventriculography in some of the situations discussed above.
Subject(s)
Angiocardiography/methods , Aortic Valve/physiopathology , Coronary Disease/physiopathology , Myocardial Infarction/physiopathology , Adult , Aged , Cardiomyopathies/physiopathology , Computers , Computers, Analog , Female , Heart Diseases/physiopathology , Heart Valve Diseases/physiopathology , Heart Ventricles/physiopathology , Humans , Male , Middle AgedABSTRACT
Following venous injection of radiopaque contrast material, digital subtraction angiography was employed to examine coronary bypass grafts in ten patients. In LAO projection 18 of 24 grafts could be identified. This result shows the ability to assess patency of bypass grafts using computerized fluoroscopy.
