Assessment of uncertainty and risk in modeling regional heavy-metal accumulation in agricultural soils

Present agricultural land use and atmospheric deposition may lead to heavy-metal accumulation rates in soils that may violate soil quality standards in the future. To undertake suitable preventive measures against heavy-metal enrichment, flux balances in agroecosystems and their uncertainties have to be assessed. For this reason we developed an empirical stochastic model, PROTERRA-S, that considers heavy-metal inputs through agricultural management as well as outputs by crop removal and leaching on a regional scale. In this manuscript we describe application of PROTERRA-S to the Sundgau region in Switzerland. Considering uncertainty in informational and natural variability, large variations of the aggregated regional cadmium and zinc balances were found, with standard deviations that were of the same order of magnitude as their average values. Uncertainty in the simulated net zinc flux originated mainly from uncertainty in the zinc concentrations of manure and crops and from uncertainty in atmospheric deposition of zinc. For cadmium, the main contribution to the total uncertainty came from uncertainty in crop concentration, regression functions to estimate Freundlich parameters, atmospheric deposition, and from spatial variation of soil pH and cation exchange capacity (CEC). For both zinc and cadmium, informational uncertainty in input data were large, indicating that significant uncertainty reduction could be achieved by additional data collection campaigns. A monetary risk value for the regional zinc accumulation rate in Sundgau was calculated to be on the order of 22 million Euro.

A central neural circuit for experience-independent olfactory and courtship behavior in Drosophila melanogaster

We have studied the function of the major central olfactory pathway in fruit flies. Key elements of this pathway, the projection neurons (PNs), connect the antennal lobes with the lateral protocerebrum both directly and indirectly, the latter via the mushroom bodies (MBs). Transgenic expression of tetanus toxin in the majority of PNs and few MB neurons leads to defects in odor detection and male courtship. Considering behavioral data from flies lacking MBs, our results argue that the direct PN-to-lateral protocerebrum pathway is necessary and sufficient to process these experience-independent behaviors. Moreover, the involvement of an olfactory pathway in male courtship suggests a role of volatile attractive female pheromones in Drosophila.

A stochastic empirical model for regional heavy-metal balances in agroecosystems

Mass flux balancing provides essential information for preventive strategies against heavy-metal accumulation in agricultural soils that may result from atmospheric deposition and application of fertilizers and pesticides. In this paper we present the empirical stochastic balance model, PROTERRA-S, that estimates heavy-metal and phosphorus accumulation in agricultural soils on the regional level. The basic units of these balances are land use systems defined by livestock production and cultivated crops. The model is designed to use available databases, such as regional agricultural statistics and soil information systems. In a case study, we assessed the phosphorus, cadmium, and zinc balances for the Sundgau region, Switzerland. The regional P requirements of crops were mainly supplied by animal manure (56%) and commercial fertilizers (40%). Net cadmium fluxes of the land use systems ranged from 1.0 g ha(-1) yr(-1) (dairy and mixed farm types) to 17.8 g ha(-1) yr(-1) (animal husbandry systems), whereas the regional net cadmium flux was only 1.4 g ha(-1) yr(-1). The regional net zinc flux was 605 g ha(-1) yr(-1). The smallest net zinc flux of 101 g ha(-1) yr(-1) was found for an arable farm type, whereas for animal husbandry systems fluxes up to 39.8 kg ha(-1) yr(-1) were estimated. Comparison of model results with reported metal balances of experimental farms shows that identification of agricultural land with high risks of heavy-metal accumulation benefits from stratification of heavy-metal balances according to land use systems while accounting for their P fertilization plans. Consequently, the model may support sustainable management of heavy-metal cycles in agricultural soils.

The role of condensation and coagulation in aerosol monitoring

We derive general-purpose mathematical model for pollution concentration studies. The model is based on the aerosol general dynamic equation (GDE). It accounts for aerosol processes like coagulation and growth by deposition and is therefore suited for suspended-particle monitoring. Our model is validated by controlled experiments done using standard aerosol monitoring devices that measure PM10, particle cross section, particle-bound polycyclic aromatic hydrocarbons (PPAHs) and number concentration, showing an excellent agreement with the experimental data in a 77-m(3) room with a time sequence of cigarettes smoked. As an example of an application, we calculated the mean PPAH emission rate in environmental tobacco smoke (ETS) for a "smolder-smoked" cigarette and found it to be 8 ng/s for a total emission of 5.28 microg per cigarette. The results show that real aerosol dynamics should be taken into account when monitoring suspended particles.

Low-dose theophylline does not exert its anti-inflammatory effects in mild asthma through upregulation of interleukin-10 in alveolar macrophages

BACKGROUND

There is accumulating evidence that theophylline has anti-inflammatory or immunomodulatory effects. This may be, in part, mediated via an upregulation in the production of the anti-inflammatory cytokine interleukin (IL)-10. We determined whether low-dose theophylline (LDT) would increase the production of IL-10, and attenuate the production of proinflammatory cytokines by alveolar macrophages.

METHODS

In a double-blind, placebo-controlled, crossover study involving 15 steroid-free patients with mild asthma, fiberoptic bronchoscopy and bronchoalveolar lavage (BAL) were performed at the end of the treatment and placebo periods. Alveolar macrophages were cultured in vitro, and we measured their release of IL-10, GM-CSF, and TNF-alpha. We also measured IL-10 production in whole blood together with the number of monocytes and T cells expressing intracellular IL-10 by flow cytometry.

RESULTS

LDT did not increase the production of IL-10, or attenuate the production of GM-CSF or TNF-alpha by alveolar macrophages. However, after theophylline treatment, there was a significant reduction in mean (SD) (95% CI) BAL eosinophil number from 3.4 (1.7)% (95% CI 2.4-4.4) to 1.7 (1.0)% (95% CI 1.1-2.3) compared with placebo (P<0.05). Similarly, there was no increase in whole-blood IL-10 release or in the number of monocytes and T cells expressing intracellular IL-10 after treatment.

CONCLUSIONS

LDT has an anti-inflammatory effect in asthma; however, this effect is not mediated via the production of IL-10 or the attenuation of GM-CSF or TNF-alpha. The mechanisms of theophylline activity remain to be determined.

Ephaptic interactions in the mammalian olfactory system

Ephaptic coupling refers to interactions between neurons mediated by current flow through the extracellular space. Ephaptic interactions between axons are considered negligible, because of the relatively large extracellular space and the layers of myelin that separate most axons. By contrast, olfactory nerve axons are unmyelinated and arranged in tightly packed bundles, features that may enhance ephaptic coupling. We tested the hypothesis that ephaptic interactions occur in the mammalian olfactory nerve with the use of a computational approach. Numerical solutions of models of axon fascicles show that significant ephaptic interactions occur for a range of physiologically relevant parameters. An action potential in a single axon can evoke action potentials in all other axons in the fascicle. Ephaptic interactions can also lead to synchronized firing of independently stimulated axons. Our findings suggest that ephaptic interactions may be significant determinants of the olfactory code and that such interactions may occur in other, similarly organized axonal or dendritic bundles.

Patent foramen ovale presenting as platypnea-orthodeoxia: diagnosis by transesophageal echocardiography

Platypnea-orthodeoxia is a rare syndrome that is often associated with interatrial shunting through a patent foramen ovale or atrial septal defect. We describe the case of a 65-year-old woman with progressive dyspnea and hypoxia when standing and walking, which was relieved by assuming the recumbent position. The diagnosis was confirmed by tilt-table transesophageal echocardiography demonstrating a large right-to-left shunt through a patent foramen ovale while the patient was in a semiupright position and no significant shunt while in a recumbent position. This case demonstrates that platypnea-orthodeoxia caused by a patent foramen ovale can be clearly demonstrated by the technique of contrast transesophageal echocardiography performed on a tilt table.

Beta-enolase deficiency, a new metabolic myopathy of distal glycolysis

A severe muscle enolase deficiency, with 5% of residual activity, was detected in a 47-year-old man affected with exercise intolerance and myalgias. No rise of serum lactate was observed with the ischemic forearm exercise. Ultrastructural analysis showed focal sarcoplasmic accumulation of glycogen beta particles. The enzyme enolase catalyzes the interconversion of 2-phosphoglycerate and phosphoenolpyruvate. In adult human muscle, over 90% of enolase activity is accounted for by the beta-enolase subunit, the protein product of the ENO3 gene. The beta-enolase protein was dramatically reduced in the muscle of our patient, by both immunohistochemistry and immunoblotting, while alpha-enolase was normally represented. The ENO3 gene of our patient carries two heterozygous missense mutations affecting highly conserved amino acid residues; a G467A transition changing a glycine residue at position 156 to aspartate, in close proximity to the catalytic site, and a G1121A transition changing a glycine to glutamate at position 374. These mutations were probably inherited as autosomal recessive traits since the mother was heterozygous for the G467A and a sister was heterozygous for the G1121A transition. Our data suggest that ENO3 mutations result in decreased stability of mutant beta-enolase. Muscle beta-enolase deficiency should be considered in the differential diagnosis of metabolic myopathies due to inherited defects of distal glycolysis.

Low-dose theophylline reduces eosinophilic inflammation but not exhaled nitric oxide in mild asthma

Theophylline is well-established in the management of asthma, and there is some evidence of an antiinflammatory effect in asthma. It is not known whether theophylline affects inflammatory markers such as sputum eosinophils and exhaled nitric oxide (NO) in patients with mild asthma not receiving inhaled steroid therapy. In a double-blind, placebo-controlled, cross-over study of 15 patients with mild asthma, we assessed the effect of low-dose theophylline therapy (250 mg twice per day) on eosinophils in induced sputum, bronchoalveolar lavage (BAL) and airway biopsies at the end of both the treatment and placebo periods. Measurements of exhaled nitric oxide (NO) were made at the end of the active and placebo treatment periods of 5 wk each. Low-dose theophylline (mean serum level, 6.1 mg/L) led to a significant reduction in mean (95% confidence interval [CI]) sputum eosinophils from 11.3% (7.80-14.76%) to 8.0% (5.46-10.44%), BAL eosinophils from 3.4% (2.4-4.4%) to 1.7% (1.1-2.3%) and biopsy eosinophils from 1.83% (0.76-2.89%) to 1.20% (0.27-2.13%) compared with placebo (all p < 0.05). There was no significant change in levels of exhaled NO or improvement in lung function and bronchial responsiveness. Low-dose theophylline induced antiinflammatory effects in asthma, reflected by a fall in airway eosinophils with no change in exhaled NO or changes in lung function.

Membrane bistability in olfactory bulb mitral cells

Whole-cell patch-clamp recordings were used to investigate the electrophysiological properties of mitral cells in rat main olfactory bulb brain slice preparations. The majority of mitral cells are bistable. These cells spontaneously alternate between two membrane potentials, separated by approximately 10 mV: a relatively depolarized potential (upstate), which is perithreshold for spike generation, and a relatively hyperpolarized potential (downstate), in which spikes do not occur. Bistability occurs spontaneously in the absence of ionotropic excitatory or inhibitory synaptic inputs. Bistability is voltage dependent; transition from the downstate to the upstate is a regenerative event activated by brief depolarization. A brief hyperpolarization can switch the membrane potential from the upstate to the downstate. In response to olfactory nerve (ON) stimulation, mitral cells in the upstate are more likely to fire an action potential than are those in the downstate. ON stimulation can switch the membrane potential from the downstate to the upstate, producing a prolonged and amplified depolarization in response to a brief synaptic input. We conclude that bistability is an intrinsic property of mitral cells that is a major determinant of their responses to ON input.

The Deep Inferior Epigastric Perforator Free Flap for Breast Reconstruction

Deep inferior epigastric perforator (DIEP) flap breast reconstruction is an improved method of autologous tissue breast reconstruction with minimal insult to the abdominal wall. This study summarizes the data collected on 148 consecutive DIEP flaps used for breast reconstruction in 109 patients. Of the patients, 90.7% had immediate breast reconstruction after mastectomy, 6.5% had secondary reconstruction, and 2.8% had bilateral reconstruction after having had a mastectomy and having a new primary cancer diagnosed in the remaining breast. A total of 78.7% patients underwent unilateral reconstruction, 21.3% underwent bilateral reconstruction, and 15.7% needed two flaps to make a single larger breast. There was one flap failure. Incidence of fat necrosis was 6.8% and incidence of incisional hernia was 1.4%. The advantages of a free transverse rectus abdominis musculocutaneous flap breast reconstruction are inherent in DIEP flap breast reconstruction. The increased technical effort for DIEP flap reconstruction is offset by the lesser insult to the abdominal wall with maintenance of the entire rectus abdominis muscle.

A psychological view of people with serious mental illness

Focusing on a variety of relevant psychological theories, this chapter addresses important elements in the recovery process for people with serious mental disabilities.

Reliability of the isokinetic trunk extensor test, Biering-Sørensen test, and Astrand bicycle test: assessment of intraclass correlation coefficient and critical difference in patients with chronic low back pain and healthy individuals

STUDY DESIGN

A reliability study was performed.

OBJECTIVE

To determine the intersession reproducibility of the isokinetic trunk extensor strength test, the Biering-Sørensen test, and the Astrand test by calculation of the intraclass correlation coefficient and the critical difference.

SUMMARY OF BACKGROUND DATA

Several physical measurements have been used in clinical evaluation of patients with chronic low back pain. Reliability can be evaluated by calculation of either intraclass correlation coefficient or critical difference, but interpretation of the results may vary depending on which method is used.

METHODS

For this study, 31 patients with chronic low back pain carried out the isokinetic trunk extensor test, the Biering-Sørensen test, and the Astrand test as also did age- and gender-matched healthy individuals. Measurements were performed in three separate sessions at the same time of the day and by the same experienced examiner. The intervals between the sessions were 5 to 10 days.

RESULTS

The isokinetic tests showed a learning effect between Tests 1 and 2. For the isokinetic test, the critical difference increased with increased angular velocities from 28% to 63% in the patients and from 27% to 39% in the healthy subjects. The critical differences for the patients and the healthy individuals were 57% vs 54% for the Biering-Sørensen test and 21% vs 23% for the Astrand test, respectively. The intraclass correlation coefficient ranged from 93% to 98% in the patients and 80%-98% in the healthy individuals.

CONCLUSIONS

The reliability was found to be acceptable for the Astrand test and the isokinetic test at 60 degrees per second, as evaluated by the critical difference. All the tests were highly reliable according to the intraclass correlation coefficient, except for Biering-Sørensen test for healthy individuals. The critical difference is the preferable measure because calculation of the intraclass correlation coefficient may give a misleading high estimate of reliability.

[Effect of retinal coagulation status on oxidative metabolite and VEGF in 208 patients with proliferative diabetic retinopathy]

BACKGROUND

Oxidative metabolites and different cytokines are believed to be involved in the pathogenesis of (proliferative) diabetic retinopathy. It was the aim of this study to analyze vitreous body and proliferations of diabetic patients for oxidative metabolites and VEGF und to correlate these values to the retinal coagulation status.

PATIENTS AND METHODS

The study was performed in 208 patients vitrectomized for diabetic retinopathy (Type I: n = 114, Type II: n = 94). Grouping of patients was performed according to retinal coagulations status: (1) no or minimal preoperative coagulation [mean coagulation area, CA: 156 mm2], (2) coagulation (scatter laser coagulation und/oder cryopexy) < 3 months before surgery [CA: 589 mm2]. (3) coagulation > 3 months before surgery [CA: 546 mm2]. In the vitreous body and, if present, in the fibrovascular proliferations (Type I: n = 83; Type II: n = 73) the level of lipid peroxides (LPO, measured with two methods) and VEGF was determined.

RESULTS

In the vitreous body LPO in group 1 were significantly (P < 0.01 (Type I und II)) higher as compared to other groups. In group 3 LPO were significantly lower as compared to group 2 (P < 0.01 (Typ I) and P < 0.05 (Typ II)). Similar results were observed in the proliferations. In Type I patients VEGF values were significantly (P < 0.01 for group 1 vs. 2 and groups 1/2 vs. 3) reduced following coagulation and coagulation + 3 months. In Type II patients only group 3 was significantly (P < 0.01) different from group 1. In proliferations groups 2 and 3 were significantly different from group 1 (P < 0.05 for Typ I and Type II patients).

CONCLUSIONS

The time course of the values leads to the conclusion that oxidative metabolites are able to directly modulate growth activity and to exert this effect via induction of VEGF. This hypothesis has to be confirmed in vitro and by means of a prospective study.

Differential stable isotope labeling of peptides for quantitation and de novo sequence derivation

We have demonstrated the use of per-methyl esterification of peptides for relative quantification of proteins between two mixtures of proteins and automated de novo sequence derivation on the same dataset. Protein mixtures for comparison were digested to peptides and resultant peptides methylated using either d0- or d3-methanol. Methyl esterification of peptides converted carboxylic acids, such as are present on the side chains of aspartic and glutamic acid as well as the carboxyl terminus, to their corresponding methyl esters. The separate d0- and d3-methylated peptide mixtures were combined and the mixture subjected to microcapillary high performance liquid chromatography/tandem mass spectrometry (HPLC/MS/MS). Parent proteins of methylated peptides were identified by correlative database searching of peptide tandem mass spectra. Ratios of proteins in the two original mixtures could be calculated by normalization of the area under the curve for identical charge states of d0- to d3-methylated peptides. An algorithm was developed that derived, without intervention, peptide sequence de novo by comparison of tandem mass spectra of d0- and d3-peptide methyl esters.