Long-term adaptation of methanol-fed thermophilic (55 °C) sulfate-reducing reactors to NaCl

A laboratory-scale upflow anaerobic sludge bed (UASB) reactor was operated during 273 days at increasing NaCl concentrations (0.5–12.5 g NaCl l^–1) to assess whether the stepwise addition of the salt NaCl results in the acclimation of that sludge. The 6.5-l thermophilic (55 °C), sulfidogenic [a chemical oxygen demand (COD) to SO₄^2– ratio of 0.5] UASB reactor operated at an organic loading rate of 5 g COD l^–1 day^–1, a hydraulic retention time of 10 h and was fed with methanol as the sole electron donor. The results show that the adaptation of the thermophilic, sulfidogenic methanol-degrading biomass to a high osmolarity environment is unlikely to occur. Sulfide was the main mineralization product from methanol degradation, regardless of the NaCl concentration added to the influent. However, sulfide production in the reactor steadily decreased after the addition of 7.5 g NaCl l^–1, whereas acetate production was stimulated at that influent NaCl concentration. Batch tests performed with sludge harvested from the UASB reactor when operating at different influent salinities confirmed that acetate is the main metabolic product at NaCl concentrations higher than 12.5 g l^–1. The apparent order of NaCl toxicity towards the different trophic groups was found to be: sulfate-reducing bacteria > methane-producing archaea > acetogenic bacteria.     

Outcome study: periareolar mammaplasty patients' perspective

Residual scars on occasion compromise patient satisfaction with breast reduction procedures. Periareolar breast reduction was proposed to minimize the scarring produced by the operation. This technique was criticized predominantly for producing a breast with low projection, for recurrence of ptosis after surgery, and for widening of the periareolar scar. The purpose of this study was to evaluate patient satisfaction from this technique. In the first branch of the study, 11 patients who had periareolar or circumareolar breast reduction were compared with 13 patients who had vertical scar reduction mammaplasty. The groups were matched for patient's age, size of reduction, and follow-up period. The patients were contacted by phone and requested to comment on four aspects of their operation: breast size, symmetry, quality of scars, and appearance and position of the nipple-areola complex. The replies were converted to numerical values and analyzed statistically. A panel of three women, prospective patients for breast reduction, were presented with standardized five-view before-and-after photographs and requested to score the results using the same criteria. Their responses were analyzed in the same manner. Both phases of the study produced similar results. Breast reduction done through a periareolar scar scored higher than a vertical scar technique. The operation did not differ with respect to shape, symmetry, or nipple-areola shape but did with respect to dissatisfaction with scars, which affected the overall result. This experimental model of assessing results of cosmetic operations is proposed as a tool to assess the patient's rather than the surgeon's perspective of a surgical technique, and it could find application in assessing other cosmetic operations.     

Diffusional properties of methanogenic granular sludge: 1H NMR characterization

The diffusive properties of anaerobic methanogenic and sulfidogenic aggregates present in wastewater treatment bioreactors were studied using diffusion analysis by relaxation time-separated pulsed-field gradient nuclear magnetic resonance (NMR) spectroscopy and NMR imaging. NMR spectroscopy measurements were performed at 22 degrees C with 10 ml of granular sludge at a magnetic field strength of 0.5 T (20 MHz resonance frequency for protons). Self-diffusion coefficients of H(2)O in the investigated series of mesophilic aggregates were found to be 51 to 78% lower than the self-diffusion coefficient of free water. Interestingly, self-diffusion coefficients of H(2)O were independent of the aggregate size for the size fractions investigated. Diffusional transport occurred faster in aggregates growing under nutrient-rich conditions (e.g., the bottom of a reactor) or at high (55 degrees C) temperatures than in aggregates cultivated in nutrient-poor conditions or at low (10 degrees C) temperatures. Exposure of aggregates to 2.5% glutaraldehyde or heat (70 or 90 degrees C for 30 min) modified the diffusional transport up to 20%. In contrast, deactivation of aggregates by HgCl(2) did not affect the H(2)O self-diffusion coefficient in aggregates. Analysis of NMR images of a single aggregate shows that methanogenic aggregates possess a spin-spin relaxation time and self-diffusion coefficient distribution, which are due to both physical (porosity) and chemical (metal sulfide precipitates) factors.     

Effects of emotion-oriented care on elderly people with cognitive impairment and behavioral problems in residential homes

This study investigates the effects of emotion-oriented care on the behavior of elderly people with cognitive impairment and behavioral problems. This approach is mainly based on the validation approach, but uses also insights from other approaches like reminiscence and sensory stimulation. Sixteen homes for the aged with structured day care units were randomly allocated to an intervention or control group. 151 Residents with cognitive impairment and behavioral problems were included in the study. The eight intervention homes received a training program with regard to emotion-oriented care. In the eight control homes usual care was continued. Measurements were performed at baseline and after three, six and twelve months of follow-up (assessment by caregivers and relatives). The primary outcome measure was the change in behavior of the residents. The results of multilevel analyses (overall, subgroup and per protocol) showed no statistically significant, nor clinically relevant effects in favor of the intervention group on the behavioral outcome measures. A possible reason for this is that the intervention did not result in significant contrast between the study groups. There is insufficient scientific evidence yet to justify the implementation of emotion-oriented care in residential homes, for residents with moderate to severe cognitive impairment and behavioral problems, on a large scale. Additional studies are needed in which special attention should be given to the implementation process.     

Biological reduction of nitric oxide in aqueous Fe(II)EDTA solutions

The reduction of nitric oxide (NO) in aqueous solutions of Fe(II)EDTA is one of the core processes in BioDeNOx, an integrated physicochemical and biological technique for NO(x)() removal from industrial flue gases. NO reduction in aqueous solutions of Fe(II)EDTA (20-25 mM, pH 7.2 +/- 0.2) was investigated in batch experiments at 55 degrees C. Reduction of NO to N(2) was found to be biologically catalyzed with nitrous oxide (N(2)O) as an intermediate. Various sludges from full-scale denitrifying and anaerobic reactors were capable to catalyze NO reduction under thermophilic conditions. The NO reduction rate was not affected by the presence of ethanol or acetate. EDTA-chelated Fe(II) was found to be a suitable electron donor for the biological reduction of nitric oxide to N(2), with the concomitant formation of Fe(III)EDTA. In the presence of ethanol, EDTA-chelated Fe(III) was reduced to Fe(II)EDTA. This study strongly indicates that redox cycling of FeEDTA plays an important role in the biological denitrification process within the BioDeNOx concept.     

The expression level determines the surface distribution of the transferrin receptor in Trypanosoma brucei

The transferrin receptor (TfR) of Trypanosoma brucei is a heterodimer attached to the surface membrane by a glycosylphosphatidylinositol (GPI) anchor. The TfR is restricted to the flagellar pocket, a deep invagination of the plasma membrane. The membrane of the flagellar pocket and the rest of the cell surface are continuous, and the mechanism that selectively retains the TfR in the pocket is unknown. Here, we report that the TfR is retained in the flagellar pocket by a specific and saturable mechanism. In bloodstream-form trypanosomes transfected with the TfR genes, TfR molecules escaped flagellar pocket retention and accumulated on the entire surface, even at modest (threefold) overproduction levels. Similar surface accumulation was observed when the TfR levels were physiologically upregulated threefold when trypanosomes were starved for transferrin. These results suggest that the TfR flagellar pocket retention mechanism is easily saturated and that control of the expression level is critical to maintain the restricted surface distribution of the receptor.     

Molecular cloning and partial characterization of a plant VAP33 homologue with a major sperm protein domain

In a search for proteins interacting with the resistance protein Cf9 from tomato, a new cDNA was cloned and characterized. Protein sequence database searches suggested that the 120 residue-N terminal domain of the encoded protein (named VAP27) is highly similar to the VAP33 protein family from animals, to uncharacterized plant proteins, and to a lower extent, to the major sperm protein (MSP) from nematodes. The second half of the protein is similar to VAMP and to the VAP33 N-terminus comprising a predicted coiled-coil region followed by a transmembrane segment. The sequence/structure comparison of VAP27 with the crystal structure of AsMSP1 from Ascaris suum, using molecular modeling with the threading method, suggested that the N-terminus of VAP27 does possess a MSP-like domain that might participate in the formation of a protein-protein network. The coiled-coil region of VAP27 was modeled based on the structure of the VAP- and VAMP-containing SNARE complex. The coiled-coil region might also be involved in protein-protein interactions similar to VAP-VAMP interactions.     

Increased cell division but not thymic dysfunction rapidly affects the T-cell receptor excision circle content of the naive T cell population in HIV-1 infection

Recent thymic emigrants can be identified by T cell receptor excision circles (TRECs) formed during T-cell receptor rearrangement. Decreasing numbers of TRECs have been observed with aging and in human immunodeficiency virus (HIV)-1 infected individuals, suggesting thymic impairment. Here, we show that in healthy individuals, declining thymic output will affect the TREC content only when accompanied by naive T-cell division. The rapid decline in TRECs observed during HIV-1 infection and the increase following HAART are better explained not by thymic impairment, but by changes in peripheral T-cell division rates. Our data indicate that TREC content in healthy individuals is only indirectly related to thymic output, and in HIV-1 infection is mainly affected by immune activation.     

Large-scale screening assay to measure epidermal growth factor internalization

Recently, we showed that the internalization of the epidermal growth factor (EGF) receptor is inhibited by hydrogen peroxide (H(2)O(2)) in human fibroblasts. In order to test the effect of various stress conditions on receptor internalization and to test a variety of antioxidants in their capacity to prevent or reduce the H(2)O(2)-induced inhibition of internalization, a screening assay was developed to measure the internalization in 96-well plates. In this assay, cells are exposed to biotin-conjugated EGF and the amount of internalized EGF is detected with horseradish peroxidase-conjugated streptavidin. We show that the results obtained by this new assay are comparable with those from internalization studies performed with radioactive labeled EGF. Therefore, the cellular internalization assay as presented here is a reliable method to measure EGF receptor internalization. Moreover, because elaborate processing of the cells is not required, the assay is a relatively fast and inexpensive method to study ligand-induced internalization in 96-well plates and thereby is suitable for large-scale screening of compounds or conditions interfering with this internalization.