Anaerobic Bioremediation of Groundwater Containing a Mixture of 1,1,2,2-Tetrachloroethane and Chloroethenes

This study investigated the biotransformation pathways of 1,1,2,2-tetrachloroethane (1,1,2,2-TeCA) in the presence of chloroethenes (i.e. tetrachloroethene, PCE; trichloroethene, TCE) in anaerobic microcosms constructed with subsurface soil and groundwater from a contaminated site. When amended with yeast extract, lactate, butyrate, or H₂ and acetate, 1,1,2,2-TeCA was initially dechlorinated via both hydrogenolysis to 1,1,2-trichloroethane (1,1,2-TCA) (major pathway) and dichloroelimination to dichloroethenes (DCEs) (minor pathway), with both reactions occurring under sulfidogenic conditions. In the presence of only H₂, the hydrogenolysis of 1,1,2,2-TeCA to 1,1,2-TCA apparently required the presence of acetate to occur. Once formed, 1,1,2-TCA was degraded predominantly via dichloroelimination to vinyl chloride (VC). Ultimately, chloroethanes were converted to chloroethenes (mainly VC and DCEs) which persisted in the microcosms for very long periods along with PCE and TCE originally present in the groundwater. Hydrogenolysis of chloroethenes occurred only after highly reducing methanogenic conditions were established. However, substantial conversion to ethene (ETH) was observed only in microcosms amended with yeast extract (200 mg/l), suggesting that groundwater lacked some nutritional factors which were likely provided to dechlorinating microorganisms by this complex organic substrate. Bioaugmentation with an H₂-utilizing PCE-dechlorinating Dehalococcoides spp. -containing culture resulted in the conversion of 1,1,2,2-TeCA, PCE and TCE to ETH and VC. No chloroethanes accumulated during degradation suggesting that 1,1,2,2-TeCA was degraded through initial dichloroelimination into DCEs and then typical hydrogenolysis into ETH and VC.     

Magnetic Resonance Imaging Allows the Evaluation of Tissue Damage and Regeneration in a Mouse Model of Critical Limb Ischemia

Magnetic resonance imaging (MRI) provides non-invasive, repetitive measures in the same individual, allowing the study of a physio-pathological event over time. In this study, we tested the performance of 7 Tesla multi-parametric MRI to monitor the dynamic changes of mouse skeletal muscle injury and regeneration upon acute ischemia induced by femoral artery dissection. T2-mapping (T2 relaxation time), diffusion-tensor imaging (Fractional Anisotropy) and perfusion by Dynamic Contrast-Enhanced MRI (K-trans) were measured and imaging results were correlated with histological morphometric analysis in both Gastrocnemius and Tibialis anterior muscles. We found that tissue damage positively correlated with T2-relaxation time, while myofiber regeneration and capillary density positively correlated with Fractional Anisotropy. Interestingly, K-trans positively correlated with capillary density. Accordingly, repeated MRI measurements between day 1 and day 28 after surgery in ischemic muscles showed that: 1) T2-relaxation time rapidly increased upon ischemia and then gradually declined, returning almost to basal level in the last phases of the regeneration process; 2) Fractional Anisotropy dropped upon ischemic damage induction and then recovered along with muscle regeneration and neoangiogenesis; 3) K-trans reached a minimum upon ischemia, then progressively recovered. Overall, Gastrocnemius and Tibialis anterior muscles displayed similar patterns of MRI parameters dynamic, with more marked responses and less variability in Tibialis anterior. We conclude that MRI provides quantitative information about both tissue damage after ischemia and the subsequent vascular and muscle regeneration, accounting for the differences between subjects and, within the same individual, between different muscles.     

Straightforward method for calibration of mechanistic cation exchange chromatography models for industrial applications

Mechanistic modeling of chromatography processes is one of the most promising techniques for the digitalization of biopharmaceutical process development. Possible applications of chromatography models range from in silico process optimization in early phase development to in silico root cause investigation during manufacturing. Nonetheless, the cumbersome and complex model calibration still decelerates the implementation of mechanistic modeling in industry. Therefore, the industry demands model calibration strategies that ensure adequate model certainty in a limited amount of time. This study introduces a directed and straightforward approach for the calibration of pH-dependent, multicomponent steric mass action (SMA) isotherm models for industrial applications. In the case investigated, the method was applied to a monoclonal antibody (mAb) polishing step including four protein species. The developed strategy combined well-established theories of preparative chromatography (e.g. Yamamoto method) and allowed a systematic reduction of unknown model parameters to 7 from initially 32. Model uncertainty was reduced by designing two representative calibration experiments for the inverse estimation of remaining model parameters. Dedicated experiments with aggregate-enriched load material led to a significant reduction of model uncertainty for the estimates of this low-concentrated product-related impurity. The model was validated beyond the operating ranges of the final unit operation, enabling its application to late-stage downstream process development. With the proposed model calibration strategy, a systematic experimental design is provided, calibration effort is strongly reduced, and local minima are avoided.     

Homeostasis of cell composition during prolonged darkness

The chemical composition of organisms in relation to their environmental resource availability is an area of intense research activity. We studied the changes in cell composition of the cyanobacterium Phormidium autumnale in response to prolonged darkness. Cells allocated their internal resources in a homeostatic manner, oxidizing all the three major cellular constituents in a proportional way. This resulted in constant C/N and carbohydrates, lipids and proteins ratios that remained unaltered throughout the whole incubation period. We propose the maintenance of balanced cell composition (homeostasis) as an evolutionary strategy related to environmental transitory changes.     

Temporal generalization accounts for response resurgence in the peak procedure

The peak interval (PI) procedure is commonly used to evaluate animals' ability to produce timed intervals. It consists of presenting fixed interval (FI) schedules in which some of the trials are replaced by extended non-reinforced trials. Responding will often resume (resurge) at the end of the non-reinforced trials unless precautions are taken to prevent it. Response resurgence was replicated in rats and pigeons. Variation of the durations of the FI and the non-reinforced probe trials showed it to be dependent on the time when reinforcement is expected. Timing of both the normal time to reinforcement, and the subsequent time to reinforcement during the probe trials followed Weber's law. A quantitative model of resurgence is described, suggesting how animals respond to the signaling properties of reinforcement omission. Model results were simulated using a stochastic binary counter.     

Bladder Cancer After Radiotherapy for Prostate Cancer

External beam radiotherapy (EBRT) is frequently used in the management of prostate cancer (PCa) as definitive, postoperative, or salvage local treatment. Although EBRT plays a central role in the management of PCa, complications remain a troubling by-product. Several studies have demonstrated an association between radiotherapy and elevated risk of acute and late toxicities. A secondary malignancy induced by initial therapy represents one of the most serious complications related to definitive cancer treatment. The radiation-related secondary primary malignancy risk increases with increasing survival time. Transitional cell carcinoma of the bladder is the most frequent secondary primary malignancy occurring after radiotherapy and is described as more aggressive; it may be diagnosed later because some radiation oncologists believe that the hematuria that occurs after prostate EBRT is normal. Some patients treated for localized PCa will subsequently develop invasive bladder cancer requiring surgical intervention. Patients with PCa treated with EBRT should be monitored closely for the presence of bladder cancer.Key words: Bladder cancer, Prostate cancer, Radiotherapy, External beam radiotherapyThe phenomenon of radiation-inducing the carcinogenesis has been well described in literature for decades. The correlation between ionizing radiation and DNA damage has been discussed in several studies.^1–4 Most of these studies evaluated the growth of solid tumors in a large population exposed to moderate to heavy doses of radiation, such as factory workers, patients exposed to a large number of diagnostic radiographic studies, and survivors of atomic and nuclear explosions. ¹ The casual effects of radiation exposure with subsequent mutagenesis are quite clear, shown both in vivo and in vitro.² Previous radiotherapy (RT) for prostate cancer (PCa) may play an important role in the development of secondary primary bladder cancer. This is a fairly uncommon event but a very real entity, of which both urologists and radiation oncologists need to be aware.     

IL-10 Inhibits the NF-κB and ERK/MAPK-Mediated Production of Pro-Inflammatory Mediators by Up-Regulation of SOCS-3 in Trypanosoma cruzi-Infected Cardiomyocytes

Trypanosoma cruzi (T. cruzi) infection produces an intense inflammatory response which is critical for the control of the evolution of Chagas’ disease. Interleukin (IL)-10 is one of the most important anti-inflammatory cytokines identified as modulator of the inflammatory reaction. This work shows that exogenous addition of IL-10 inhibited ERK1/2 and NF-κB activation and reduced inducible nitric oxide synthase (NOS2), metalloprotease (MMP) -9 and MMP-2 expression and activities, as well as tumour necrosis factor (TNF)-α and interleukin (IL)-6 expression, in T. cruzi-infected cardiomyocytes. We found that T. cruzi and IL-10 promote STAT3 phosphorylation and up-regulate the expression of suppressor of cytokine signalling (SOCS)-3 thereby preventing NF-κB nuclear translocation and ERK1/2 phosphorylation. Specific knockdown of SOCS-3 by small interfering RNA (siRNA) impeded the IL-10-mediated inhibition of NF-κB and ERK1/2 activation. As a result, the levels of studied pro-inflammatory mediators were restored in infected cardiomyocytes. Our study reports the first evidence that T. cruzi up- regulates SOCS-3 expression and highlights the relevance of IL-10 in the modulation of pro-inflammatory response of cardiomyocytes in Chagas’ disease.     

Comparison of rat hepatocyte and differentiated hepatoma cell line cultures as bio indicators of CYP 1A1 inducers in urban air

Cytochrome P450 1A1 CYP1A1 enzymatic activity was evaluated in cultured liver cells, and taken as a biological indicator of the presence of inducers of this isoform in urban airborne particulate matter fraction samples. It is known that CYP1A1 inducers can play an important role in the risk of mutagenesis and carcinogenesis by environmental pollution. A romatic polycyclic hydrocarbons PAH from urban air were collected in the city of Genoa Italy at two sites on two different days of the year. The objective of the study was to compare the inducibility of cultured rat hepatocytes with that of MH1C1 and FaO rat hepatoma cell lines after exposure to a PAH mixture and to a standard compound, such as benzo b fluoranthene B b F . Cytotoxic effects of the tested concentrations were evaluated by means of 3 4,5, dimenthylthyazol 2 yl 2,5 diphenyltetrazolium bromide MTT and lactate dehydrogenase release LDH tests, the potency of inducers by ethoxyresorufin O deethylase EROD assay. The results were in agreement in the three cellular systems: after exposure to the PAH mixture, an induction at low concentrations was observed; whereas no induction, but rather a decrease in activity was shown at higher concentrations; instead, the exposure to pure B b F showed a dose-response relationship in all cells, even at the highest doses. Such a difference between the toxicity of the complex mixture and that of the pure compound could be ascribed to the presence of drug metabolism inhibitors in the mixture, or to interactions between the original components and their metabolites. The finding that the cell lines responded to the CYP1A1 induction in a very efficient way gives further proof of the applicability of this system to environmental biomonitoring.     

Exome sequencing discloses <Emphasis Type="Italic">KALRN</Emphasis> homozygous variant as likely cause of intellectual disability and short stature in a consanguineous pedigree

Background

The recent availability of whole-exome sequencing has opened new possibilities for the evaluation of individuals with genetically undiagnosed intellectual disability.

Results

We report two affected siblings, offspring of first-cousin parents, with intellectual disability, hypotonia, short stature, growth hormone deficiency, and delayed bone age. All members of the nuclear family were genotyped, and exome sequencing was performed in one of the affected individuals. We used an in-house algorithm (CATCH v1.1) that combines homozygosity mapping with exome sequencing results and provides a list of candidate variants. One identified novel homozygous missense variant in KALRN (NM_003947.4:c.3644C>A: p.(Thr1215Lys)) was predicted to be pathogenic by all pathogenicity prediction software used (SIFT, PolyPhen, Mutation Taster). KALRN encodes the protein kalirin, which is a GTP-exchange factor protein with a reported role in cytoskeletal remodeling and dendritic spine formation in neurons. It is known that mice with ablation of Kalrn exhibit age-dependent functional deficits and behavioral phenotypes.

Conclusion

Exome sequencing provided initial evidence linking KALRN to monogenic intellectual disability in man, and we propose that KALRN is the causative gene for the autosomal recessive phenotype in this family.