Ah Receptor-mediated impairment of interrenal steroidogenesis involves StAR protein and P450scc gene attenuation in rainbow trout.

The objective of the study was to investigate the impact of aryl hydrocarbon receptor (AhR) activation on interrenal steroidogenesis in rainbow trout. To this end, fish were fed AhR agonist (beta-naphthoflavone (BNF): 10 mg/kg body mass/day) and antagonist (alpha-naphthoflavone (ANF): 10 mg/kg body mass/day) either singly or in combination (ABNF) for 5 days to elucidate the mechanisms involved in AhR-mediated depression of cortisol production. Liver AhR protein expression was significantly elevated only with ABNF, but not with BNF and ANF compared to the control group. However, all three treatments (BNF, ANF, and ABNF) significantly elevated cytochrome P450 1A1 (CYP1A1) gene and protein expression in the kidney and liver, respectively. Also, these three treatment groups had significantly depressed ACTH-stimulated cortisol production in vitro compared to the control group. This attenuation of interrenal steroidogenesis corresponded with a lower mRNA abundance of steroidogenic acute regulatory (StAR) protein and cytochrome P450 cholesterol side chain cleavage enzyme (P450scc), but not 11beta-hydroxylase. Furthermore, in vitro incubation of head kidney pieces with 7-3H-pregnenolone failed to show any treatment effects on pathways downstream of P450scc, except for a significantly higher conversion to progesterone in the BNF and ANF groups. Plasma cortisol and glucose levels showed no significant change between the treated groups and control, but liver and brain glucocorticoid receptor (GR) protein expression was higher in the BNF group, and ANF abolished this response. Taken together, both BNF and ANF impaired cortisol production, and the mechanism may involve attenuation of StAR and P450scc, the rate limiting steps in steroidogenesis. Overall, endocrine disruption by xenobiotics acting via AhR includes impaired cortisol biosynthesis and abnormal cortisol target tissue GR responses in rainbow trout.     

Electrolytic transport through a synthetic nanometer-diameter pore

We have produced single, synthetic nanometer-diameter pores by using a tightly focused, high-energy electron beam to sputter atoms in 10-nm-thick silicon nitride membranes. Subsequently, we measured the ionic conductance as a function of time, bath concentration, and pore diameter to infer the conductivity and ionic mobility through the pores. The pore conductivity is found to be much larger than the bulk conductivity for dilute bath concentrations, where the Debye length is larger than the pore radius, whereas it is comparable with or less than the bulk for high bath concentrations. We interpret these observations by using multiscale simulations of the ion transport through the pores. Molecular dynamics is used to estimate the ion mobility, and ion transport in the pore is described by the coupled Poisson-Nernst-Planck and the Stokes equations that are solved self-consistently for the ion concentration and velocity and electrical potential. We find that the measurements are consistent with the presence of fixed negative charge in the pore wall and a reduction of the ion mobility because of the fixed charge and the ion proximity to the pore wall.     

Comprehensive review on natural pharmacophore tethered 1,2,3-triazoles as active pharmaceuticals

The privileged 1,2,3-triazole scaffold is drawing researcher's attention due to its widespread applications in diverse fields such as drug discovery (e.g., carboxyamidotriazole), organic synthesis (click-reaction template), polymeric materials (e.g., triazolamer), supramolecular receptors (e.g., triazolophane), fluorescent materials (e.g., metal–organic frameworks), and agricultural sectors (e.g., fungicides). Various 1,2,3-triazole persuasion modules are also currently available in the market that have multiple assets such as active pharmaceuticals and agricultural purposes. Owed to the highly consistent and firmest synthesis approach, that is, click reaction of various azides and acetylene derivatives by copper (I)-catalyzed 1,3-dipolar cycloaddition (CuAAC), highly functionalized 1,2,3-triazoles are prepared in scalar yields for drug discovery. Given the importance of 1,2,3-triazole chemistry, the present review focuses specifically on the synthesis of structurally diverse 1,2,3-triazoles linked to natural pharmacophores and their biological importance. Furthermore, the dual/multi-pharmacophores assimilated 1,2,3-triazoles have listed interesting biological activities that could be valuable as future drug leads. In addition, this comprehensive review can serve as a template for the development of new diverse scaffolds that will ensure for new therapeutic approaches for the existing myriad diseases and disorders.     

Toxicokinetics and effects of PCBs in Arctic fish: a review of studies on Arctic charr

In a series of environmentally realistic laboratory experiments, toxicokinetics and effects of polychlorinated biphenyls (PCBs) were studied in the Arctic charr (Salvelinus alpinus). Winter fasting and emaciation, which are common among Arctic charr living in high latitudes, resulted in a redistribution of the lipophilic PCBs from lipid-storing tissue such as the muscle, to vital organs that must be considered sensitive toward PCB (liver and brain). This redistribution was accompanied by a significant potentiation of the hepatic cytochrome P-450 (CYP) 1A biomarker response, from low activities in October (within those measured in uncontaminated charr) to a high, probably maximum, induction in May. Performance studies demonstrated a clear effect of environmentally realistic PCB levels on endocrine mechanisms, immune function, and seawater preadaptation (smoltification) in charr that had been feed deprived for several months after contamination with Aroclor 1254, whereas a high PCB dose exerted only minor, if any, effects in charr that had been fed after contamination. These results demonstrate that emaciation results in decreased dose-response relationships in fish, and indicate that arctic animals undergoing seasonal cycles of "fattening" and emaciation may be extra sensitive toward persistent, lipophilic organochlorines. Pilot studies on Arctic charr from Bj?rn?ya Island revealed marked CYP1A biomarker responses and an upregulation of genes involved in cellular homeostatic mechanisms in charr from Lake Ellasj?en (high PCB levels).     

PCAP: a whole-genome assembly program

We describe a whole-genome assembly program named PCAP for processing tens of millions of reads. The PCAP program has several features to address efficiency and accuracy issues in assembly. Multiple processors are used to perform most time-consuming computations in assembly. A more sensitive method is used to avoid missing overlaps caused by sequencing errors. Repetitive regions of reads are detected on the basis of many overlaps with other reads, instead of many shorter word matches with other reads. Contaminated end regions of reads are identified and removed. Generation of a consensus sequence for a contig is based on an alignment of reads in the contig, in which both base quality values and coverage information are used to determine every consensus base. The PCAP program was tested on a mouse whole-genome data set of 30 million reads and a human Chromosome 20 data set of 1.7 million reads. The program is freely available for academic use.     

Fasting augments PCB impact on liver metabolism in anadromous arctic char.

Anadromous arctic char (Salvelinus alpinus) undertake short feeding migrations to seawater every summer and accumulate lipids, while the rest of the year is spent in fresh water where the accumulated lipid reserves are mobilized. We tested the hypothesis that winter fasting and the associated polychlorinated biphenyls' (PCBs) redistribution from lipid depots to critical tissues impair the liver metabolic capacity in these animals. Char were administered Aroclor 1254 (0, 1, 10, and 100 mg/kg body mass) orally and maintained for 4 months without feeding to mimic seasonal winter fasting, while fed groups (0 and 100 mg Aroclor 1254/kg) were maintained for comparison. A clear dose-related increase in PCB accumulation and cytochrome P4501A (CYP1A) protein content was observed in the livers of fasted fish. This PCB concentration and CYP1A response with the high dose of Aroclor were 1.5-fold and 3-fold greater in the fasted than in the fed fish, respectively. In fed fish, PCB exposure lowered liver glycogen content, whereas none of the other metabolic indicators were significantly affected. In fasted fish, PCB exposure depressed liver glycogen content and activities of glucose-6-phosphate dehydrogenase, alanine aminotransferase, lactate dehydrogenase, and phosphoenolpyruvate carboxykinase and elevated 3-hydroxyacylcoA dehydrogenase activity and glucocorticoid receptor protein expression. There were no significant impacts of PCB on heat shock protein 70 (hsp70) and hsp90 contents in either fed or fasted fish. Collectively, our study demonstrates that winter emaciation associated with the anadromous lifestyle predisposes arctic char to PCB impact on hepatic metabolism including disruption of the adaptive metabolic responses to extended fasting.     

Organ‐preserving surgery for penile cancer: description of techniques and surgical outcomes

Study Type – Therapy (case series) Level of Evidence 4 What's known on the subject? and What does the study add? Organ‐preserving surgeries for penile cancer have been described to reduce the morbidity associated with traditional operations. Patients derive better functional outcomes from penile‐preserving surgery, although local recurrence rates can be higher. Excellent results can be obtained at large‐volume centres. With close follow‐up, local recurrences can be identified and treated promptly (often with further local excision).

OBJECTIVE

• ? To describe the outcomes of organ‐preserving surgery for penile cancer at a UK tertiary referral centre.

PATIENTS AND METHODS

• ? Patients at Sunderland Hospital (UK) between 2001 and 2008 who had squamous cell tumours limited to the glans penis underwent penile‐preserving surgery including total glansectomy and glanuloplasty, partial glansectomy, glans relining and distal penectomy with glans reconstruction.
• ? Recurrence rates, cosmetic and functional outcomes were recorded.

RESULTS

• ? In all, 65 patients were identified with a median follow‐up of 40 months. Local recurrence was present in four patients (6%) despite 72% having intermediate or poorly differentiated tumours and 30% with T2 disease.
• ? Complications included partial graft loss (1.5%), graft contractures (4.5%) and meatal stenosis (7.5%).
• ? In all, 5% were deemed to have poor cosmetic outcome and 85% described good erections at 1 year after surgery.

CONCLUSION

• ? Penile‐preserving surgery can achieve good penile cancer control with minimal morbidity and reduced psychosexual side‐effects.