Effects of Dibutyltin Exposures on Translation Regulatory Factor S6 in Human Immune Cells

Dibutyltin is an organotin contaminating the environment through its use as a stabilizer in polyvinylchloride, PVC plastics. DBT has been found in drinking water and beverages, such as beer and wine, due to leaching from the PVC plastics used during the distribution of these drinks. Along with PVC plastics, DBT has been used as a deworming agent in poultry, infiltrating additional food products and increasing the exposure of the toxin to humans. Due to its multiple uses, it has entered the food chain and has been detected in human blood at levels as high as 0.3μM. Inflammatory cytokines are important mediators of the response to injury or infection. However, if their levels are increased in the absence of a needed immune response, chronic inflammation can occur. Chronic inflammation is associated with a number of pathologies including, rheumatoid arthritis, Crohn’s disease, atherosclerosis, and cancer. DBT can increase the synthesis of pro-inflammatory cytokines such as interferon gamma (IFNγ), tumor necrosis factor alpha (TNFα), interleukin 1 beta (IL-1β), and interleukin 6 (IL-6) in human immune cells. DBT appears to use the ERK 1/2 and/or p38 MAPK pathways to stimulate pro-inflammatory cytokine production by immune cells. MAPK pathways have the capacity to regulate translation including processes leading to the phosphorylation (activation) of the S6 ribosomal subunit. The current study examines the levels and phosphorylation state of S6 after 1-hour and 6-hour exposures to DBT in peripheral blood mononuclear cells (PBMCs). The results indicated that, within 1 hour of exposure, DBT (at several concentrations) elevated levels of phospho (P)-S6 and S6. At 6 hours of exposure, DBT caused increased levels of S6, along with significant increases at higher concentrations for P-S6. These results suggest that DBT may be elevating the synthesis of key pro-inflammatory cytokines in immune cells by its ability to activate translation

Archeota, Fall/Winter 2022

Archeota is a platform for SJSU iSchool students to contribute to the archival conversation. It is written BY students, FOR students. It provides substantive content on archival concerns and issues and promotes professional development in the field of archival studies. Archeota upholds the core values of the archival profession. Contents: The Forward Club: Archival Outreach and Community Connections By Sarah Lewis Putting the Spotlight on Women’s History: The Significance of Reevaluating Historic Site Narratives By Lawrence Mullen Meet the 2022-2023 Archeota Team Farm to Folder: Found Ephemera Joins the Dziekanowski Farm Papers Collection By Emma Ruff An Archivists’ Evolving Role By Amanda Galvez My Journey to Becoming a Certified Archivist: A Five-Year Process By Heather Reinold Farewell to Our Fall 2022 Graduates Interviews With SAA Student Chapter Leaders The Katz Family Archive: A Reflection on Identity and Artifact Ownership By Kit Katz The Writer’s Guild Foundation: Interning in the Shalverson-Webb Library By Rachael Sevilla SJSU SAA Student Chapter 2022-2023 Board SJSU SAA Student Chapter Past Events 2022-2023https://scholarworks.sjsu.edu/saasc_archeota/1016/thumbnail.jp

Bis(triphenyl-λ5-phosphanylidene)ammonium hydrogen dichloride

In the title compound, [(Ph3P)2N]+·[Cl-H-Cl]− or C36H30NP2 +·Cl2H−, the H atom of the [Cl—H—Cl]− anion and the N atom of the [(Ph3P)2N]+ cation are located on a twofold axis, yielding overall symmetry 2 for both the cation and the anion. The central P—N—P angle [144.12 (13)°] of the cation is in the expected range and indicates only weak cation–anion inter­actions. The almost linear [Cl—H—Cl]− anion is a rare example of a symmetric hydrogen bridge in a hydrogen dichloride anion. The Cl⋯Cl distance and two equal Cl—H bonds are typical of such a symmetric hydrogen dichloride anion

Pkd2 Mesenteric Vessels Exhibit a Primary Defect in Endothelium-Dependent Vasodilatation Restored by Rosiglitazone

Patients with autosomal dominant polycystic kidney disease have a high prevalence of hypertension and structural vascular abnormalities, such as intracranial aneurysms. Hypertension can develop in childhood and often precedes a significant reduction in the glomerular filtration rate. The major aim of this study was to investigate whether a primary endothelial defect or a vascular smooth muscle (VSM) defect was present in murine polycystic kidney disease (Pkd)2 heterozygous mesenteric vessels before the development of renal failure or hypertension. Using pressure myography, we observed a marked defect in ACh-stimulated endothelium-dependent vasodilatation in Pkd2 arterioles. In contrast, Pkd2 vessels responded normally to sodium nitroprusside, phenylephrine, KCl, and pressure, indicating unaltered VSM-dependent responses. Pretreatment with the peroxisome proliferator-activated receptor-gamma agonist rosiglitazone significantly restored ACh-dependent vasodilation in Pkd2 mice. Isolated heterozygous Pkd2 endothelial cells displayed normal ACh-stimulated Ca2+ and nitric oxide production. However, isolated Pkd2 heterozygous VSM cells displayed basal increases in superoxide and sodium nitroprusside-stimulated peroxynitrite formation, which were both suppressed by rosiglitazone. Furthermore, we observed a defective response of Pkd2 mesenteric venules to ACh in vivo, which was more marked after ischemia-reperfusion injury. In conclusion, the results of our study suggest that the defect in vasodilatation in Pkd2 heterozygous vessels is primarily due to a reduction in nitric bioavailability secondary to increased vascular oxidative stress. The ability of rosiglitazone to correct this phenotype suggests that this defect is potentially reversible in patients with autosomal dominant polycystic kidney disease

Spectral, mineralogical, and geochemical variations across Home Plate, Gusev Crater, Mars indicate high and low temperature alteration

Over the last ~ 3 years in Gusev Crater, Mars, the Spirit rover observed coherent variations in color, mineralogy, and geochemistry across Home Plate, an ~ 80 m-diameter outcrop of basaltic tephra. Observations of Home Plate from orbit and from the summit of Husband Hill reveal clear differences in visible/near-infrared (VNIR) colors between its eastern and western regions that are consistent with mineralogical compositions indicated by Mössbauer spectrometer (MB) and by Miniature Thermal Emission Spectrometer (Mini-TES). Pyroxene and magnetite dominate the east side, while olivine, nanophase Fe oxide (npOx) and glass are more abundant on the western side. Alpha Particle X-Ray Spectrometer (APXS) observations reveal that eastern Home Plate has higher Si/Mg, Al, Zn, Ni, and K, while Cl and Br are higher in the west. We propose that these variations are the result of two distinct alteration regimes that may or may not be temporally related: a localized, higher temperature recrystallization and alteration of the east side of Home Plate and lower temperature alteration of the western side that produced npOx

Adynamia episodica hereditaria with myotonia: A non-inactivating sodium current and the effect of extracellular pH

To study the mechanism of periodic paralysis, we investigated the properties of intact muscle fibers biopsied from a patient who had adynamia episodica hereditaria with electromyographic signs of myotonia. When the potassium concentration in the extracellular medium, [K]e, was 3.5 mmol/l, force of contraction, membrane resting potential, and intracellular sodium activity were normal, but depolarizing voltage clamp steps revealed the existence of an abnormal inward current. This current was activated at membrane potentials less negative than -80 mV, reached a maximum within 50 msec, and was not inactivated with time. The inward current was completely and reversibly blocked by tetrodotoxin, which indicates that it was carried by sodium ions. In a solution containing 9 mmol/l potassium, normal muscle would depolarize to -63 mV and yet be capable of developing full tetanic force upon stimulation. The muscle from the patient depolarized to -57 mV and became inexcitable, i.e., it was paralyzed. A contracture did not develop. Lowering of the extracellular pH did not influence the resting potential, but it effectively antagonized or prevented the paralytic effect of high [K]e by changing the inactivation characteristics of the sodium channels. Hydrochlorothiazide, which had a therapeutic effect on the patient, did not prevent paralysis in vitro. An abnormal rise of the intracellular sodium activity was recorded when the extracellular potassium concentration was raised to 10 mmol/l

Analysing the consistency of martian methane observations by investigation of global methane transport

Reports of methane on Mars at different times imply varying spatial distributions. This study examines whether different observations are mutually consistent by using a global circulation model to investigate the time evolution of methane in the atmosphere. Starting from an observed plume of methane, consistent with that reported in 2003 from ground-based telescopes, multiple simulations are analysed to investigate what is required for consistency with an inferred methane signal from the Thermal Emission Spectrometer made 60 sols later. The best agreement between the existing observations is found using continued release from a solitary source over Nili Fossae. While the peaks in methane over the Tharsis Montes, Elysium Mons and Nili Fossae regions are well aligned with the retrievals, an extra peak on the south flank of the Isidis basin is apparent in the model due to the prevailing eastward transport of methane. The absence of this feature could indicate the presence of a fast-acting localised sink of methane. These results show that the spatial and temporal variability of methane on Mars implied by observations could be explained by advection from localised time-dependent sources alongside a currently unknown methane sink. Evidence is presented that a fast trapping mechanism for methane is required. Trapping by a zeolite structure in dust particles is a suggested candidate warranting further investigation; this could provide a fast acting sink as required by this reconstruction

Simulating the interannual variability of major dust storms on Mars using variable lifting thresholds

The redistribution of a finite amount of martian surface dust during global dust storms and in the intervening periods has been modelled in a dust lifting version of the UK Mars General Circulation Model. When using a constant, uniform threshold in the model’s wind stress lifting parameterisation and assuming an unlimited supply of surface dust, multiannual simulations displayed some variability in dust lifting activity from year to year, arising from internal variability manifested in surface wind stress, but dust storms were limited in size and formed within a relatively short seasonal window. Lifting thresholds were then allowed to vary at each model gridpoint, dependent on the rates of emission or deposition of dust. This enhanced interannual variability in dust storm magnitude and timing, such that model storms covered most of the observed ranges in size and initiation date within a single multiannual simulation. Peak storm magnitude in a given year was primarily determined by the availability of surface dust at a number of key sites in the southern hemisphere. The observed global dust storm (GDS) frequency of roughly one in every 3 years was approximately reproduced, but the model failed to generate these GDSs spontaneously in the southern hemisphere, where they have typically been observed to initiate. After several years of simulation, the surface threshold field—a proxy for net change in surface dust density—showed good qualitative agreement with the observed pattern of martian surface dust cover. The model produced a net northward cross-equatorial dust mass flux, which necessitated the addition of an artificial threshold decrease rate in order to allow the continued generation of dust storms over the course of a multiannual simulation. At standard model resolution, for the southward mass flux due to cross-equatorial flushing storms to offset the northward flux due to GDSs on a timescale of ∼3 years would require an increase in the former by a factor of 3–4. Results at higher model resolution and uncertainties in dust vertical profiles mean that quasi-periodic redistribution of dust on such a timescale nevertheless appears to be a plausible explanation for the observed GDS frequency

Long-term decoding of movement force and direction with a wireless myoelectric implant

Objective. The ease of use and number of degrees of freedom of current myoelectric hand prostheses is limited by the information content and reliability of the surface electromyography (sEMG) signals used to control them. For example, cross-talk limits the capacity to pick up signals from small or deep muscles, such as the forearm muscles for distal arm amputations, or sites of targeted muscle reinnervation (TMR) for proximal amputations. Here we test if signals recorded from the fully implanted, induction-powered wireless Myoplant system allow long-term decoding of continuous as well as discrete movement parameters with better reliability than equivalent sEMG recordings. The Myoplant system uses a centralized implant to transmit broadband EMG activity from four distributed bipolar epimysial electrodes. Approach. Two Rhesus macaques received implants in their backs, while electrodes were placed in their upper arm. One of the monkeys was trained to do a cursor task via a haptic robot, allowing us to control the forces exerted by the animal during arm movements. The second animal was trained to perform a center-out reaching task on a touchscreen. We compared the implanted system with concurrent sEMG recordings by evaluating our ability to decode time-varying force in one animal and discrete reach directions in the other from multiple features extracted from the raw EMG signals. Main results. In both cases, data from the implant allowed a decoder trained with data from a single day to maintain an accurate decoding performance during the following months, which was not the case for concurrent surface EMG recordings conducted simultaneously over the same muscles. Significance. These results show that a fully implantable, centralized wireless EMG system is particularly suited for long-term stable decoding of dynamic movements in demanding applications such as advanced forelimb prosthetics in a wide range of configurations (distal amputations, TMR).German Federal Ministry for Education and Reseach (BMBF) grant No, 16SV3695, 16SV3699, 16SV3697 and 01GQ1005C, DFG Deutsche Forschungsgemeinschaft grant No. GA1475-C

Hydrophilic sulfonated bis-1,2,4-triazine ligands are highly effective reagents for separating actinides(iii) from lanthanides(iii) via selective formation of aqueous actinide complexes

We report the first examples of hydrophilic 6,6′-bis(1,2,4-triazin-3-yl)-2,2′-bipyridine (BTBP) and 2,9-bis(1,2,4-triazin-3-yl)-1,10-phenanthroline (BTPhen) ligands, and their applications as actinide(III) selective aqueous complexing agents. The combination of a hydrophobic diamide ligand in the organic phase and a hydrophilic tetrasulfonated bis-triazine ligand in the aqueous phase is able to separate Am(III) from Eu(III) by selective Am(III) complex formation across a range of nitric acid concentrations with very high selectivities, and without the use of buffers. In contrast, disulfonated bis-triazine ligands are unable to separate Am(III) from Eu(III) in this system. The greater ability of the tetrasulfonated ligands to retain Am(III) selectively in the aqueous phase than the corresponding disulfonated ligands appears to be due to the higher aqueous solubilities of the complexes of the tetrasulfonated ligands with Am(III). The selectivities for Am(III) complexation observed with hydrophilic tetrasulfonated bis-triazine ligands are in many cases far higher than those found with the polyaminocarboxylate ligands previously used as actinide-selective complexing agents, and are comparable to those found with the parent hydrophobic bis-triazine ligands. Thus we demonstrate a feasible alternative method to separate actinides from lanthanides than the widely studied approach of selective actinide extraction with hydrophobic bis-1,2,4-triazine ligands such as CyMe4-BTBP and CyMe4-BTPhen