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Background Fever accompanying vaso-occlusive crisis is a common presentation in patients with sickle cell disease (SCD) and carries a broad differential diagnosis. Here, we report a case of transfusion-transmitted malaria in a patient with SCD presenting with acute vaso-occlusive crisis and rapidly decompensating to multisystem organ failure (MSOF). Case report An 18-year-old African American male with SCD was admitted after multiple days of fever and severe generalized body pain. He received monthly blood transfusions as stroke prophylaxis. A source of infection was not readily identified, but treatment was initiated with continuous intravenous fluids and empiric antibiotics. The patient developed acute renal failure, acute hypoxic respiratory failure, and shock. He underwent red blood cell (RBC) exchange transfusion followed by therapeutic plasma exchange and continuous veno-venous hemodialysis. A manual peripheral blood smear revealed intraerythrocytic inclusions suggestive of Plasmodium, and molecular studies confirmed Plasmodium falciparum infection. Intravenous artesunate was given daily for 1 week. A look-back investigation involving two hospitals, multiple blood suppliers, and state and federal public health departments identified the source of malaria as a unit of RBCs transfused 2 weeks prior to admission. Conclusions Clinical suspicion for transfusion-related adverse events, including hemolytic transfusion reactions and transfusion-transmitted infections, should be high in typically and atypically immunocompromised patient populations (like SCD), especially those on chronic transfusion protocols. Manual blood smear review aids in the evaluation of patients with SCD presenting with severe vaso-occlusive crisis and MSOF and can alert clinicians to the need for initiating aggressive therapy like RBC exchange and artesunate therapy.

Individuals that become immunized to red blood cell (RBC) alloantigens can experience an increased rate of antibody formation to additional RBC alloantigens following subsequent transfusion. Despite this, how an immune response to one RBC immunogen may impact subsequent alloimmunization to a completely different RBC alloantigen remains unknown. Our studies demonstrate that Kell blood group antigen (KEL) RBC transfusion in the presence of inflammation induced by poly (I:C) (PIC) not only enhances anti-KEL antibody production through a CD4+ T-cell-dependent process but also directly facilitates anti-HOD antibody formation following subsequent exposure to the disparate HOD (hen egg lysozyme, ovalbumin, fused to human blood group antigen Duffy b) antigen. PIC/KEL priming of the anti-HOD antibody response required that RBCs express both the KEL and HOD antigens (HOD × KEL RBCs), as transfusion of HOD RBCs plus KEL RBCs or HOD RBCs alone failed to impact anti-HOD antibody formation in recipients previously primed with PIC/KEL. Transfer of CD4+ T cells from PIC/KEL-primed recipients directly facilitated anti-HOD antibody formation following (HOD × KEL) RBC transfusion. RBC alloantigen priming was not limited to PIC/KEL enhancement of anti-HOD alloantibody formation, as HOD-reactive CD4+ T cells enhanced anti-glycophorin A (anti-GPA) antibody formation in the absence of inflammation following transfusion of RBCs coexpressing GPA and HOD. These results demonstrate that immune priming to one RBC alloantigen can directly enhance a humoral response to a completely different RBC alloantigen, providing a potential explanation for why alloantibody responders may exhibit increased immune responsiveness to additional RBC alloantigens following subsequent transfusion.

Background There is limited data on the markers of coagulation and hemostatic activation (MOCHA) profile in Coronavirus disease 2019 (COVID-19) and its ability to identify COVID-19 patients at risk for thrombotic events and other complications. Methods Hospitalized patients with confirmed SARS-COV-2 from four Atlanta hospitals were included in this observational cohort study and underwent admission testing of MOCHA parameters (plasma d-dimer, prothrombin fragment 1.2, thrombin-antithrombin complex, fibrin monomer). Clinical outcomes included deep vein thrombosis, pulmonary embolism, myocardial infarction, ischemic stroke, access line thrombosis, ICU admission, intubation and mortality. Main results Of 276 patients (mean age 59 ± 6.4 years, 47% female, 62% African American), 45 (16%) had a thrombotic endpoint. Each MOCHA parameter was independently associated with a thrombotic event (p Conclusions An admission MOCHA profile is useful to risk-stratify COVID-19 patients for thrombotic complications and more effective than isolated d-dimer for predicting risk of ICU admission and intubation.

A heavy-ion detector was developed for decay studies in the Experimental Storage Ring (ESR) at the GSI Helmholtz Centre for Heavy Ion Research in Darmstadt, Germany. This detector serves as a prototype for the in-pocket particle detectors for future experiments with the Collector Ring (CR) at FAIR (Facility for Antiproton and Ion Research). The detector includes a stack of six silicon pad sensors, a double-sided silicon strip detector (DSSD), and a CsI(Tl) scintillation detector. It was used successfully in a recent experiment for the detection of the β+-decay of highly charged 142Pm60+ ions. Based on the Δ E / E technique for particle identification and an energy resolution of 0.9% for Δ E and 0.5% for E (Full Width at Half Maximum (FWHM)), the detector is well-suited to distinguish neighbouring isobars in the region of interest.

The impacts of emissions sources on air quality in St. Louis, Missouri are assessed for use in acute health effects studies. However, like many locations in the United States, the speciated particulate matter (PM) measurements from regulatory monitoring networks in St. Louis are only available every third day. The power of studies investigating acute health effects of air pollution is reduced when using one-in-three day source impacts compared to daily source impacts. This paper presents a temporal interpolation model to estimate daily speciated PM2.5 mass concentrations and source impact estimates using one-in-three day measurements. The model is used to interpolate 1-in-3 day source impact estimates and to interpolate the 1-in-3 day PM species concentrations prior to source apportionment (SA). Both approaches are compared and evaluated using two years (June 2001–May 2003) of daily data from the St. Louis Midwest Supersite (STL-SS). Data withholding is used to simulate a 1-in-3 day data set from the daily data to evaluate interpolated estimates. After evaluation using the STL-SS data, the model is used to estimate daily source impacts at another site approximately seven kilometers (7 km) northwest of the STL-SS (Blair); results between the sites are compared. For interpolated species concentrations, the model performs better for secondary species (sulfate, nitrate, ammonium, and organic carbon) than for primary species (metals and elemental carbon), likely due to the greater spatial autocorrelation of secondary species. Pearson correlation (R) values for sulfate, nitrate, ammonium, elemental carbon, and organic carbon ranged from 0.61 (elemental carbon, EC2) to 0.97 (sulfate). For trace metals, the R values ranged from 0.31 (Ba) to 0.81 (K). The interpolated source impact estimates also indicated a stronger correlation for secondary sources. Correlations of the secondary source impact estimates based on measurement data and interpolation data ranged from 0.68 to 0.97, whereas for primary source contribution estimates the correlations ranged from −0.042 to 0.95. Comparison of daily source impact estimates with source impacts from the interpolation models indicated that interpolation of source contributions was preferable over interpolating species concentrations then applying a SA model. This was based on better agreement in the predicted source impact concentrations and higher correlation with daily SA results. Overall, this study indicates that the temporal interpolation model produces results that may be used to estimate source impacts for health studies, though the additional uncertainty should be considered.

This work examines the kinetic and equilibrium sorption characteristics of a variety of chemical penetrants in the polyimide polymer Matrimid. Liquid equilibrium sorption for dense films with thicknesses of 50 µm for a large variety of organic species including alkanes, alcohols, acetates, furans, and ionic liquids is presented. Vapor equilibrium sorption isotherms and kinetic sorption behavior for water and C1-C6 alcohols as a function of chemical activity from 0 to 0.9 were measured using a quartz crystal microbalance with films ranging in thickness from 0.07 to 2.0 µm. Diffusion coefficients and relaxation parameters were calculated according to the diffusion-relaxation model for penetrants in glassy polymers. Diffusion coefficients at infinite dilution for water and C1-C6 alcohols are given as a function of van der Waals molar volume and a clear dependency is shown ranging from 2E-11 to 6.5E-13 cm2/s for water and hexanol, respectively, for 0.26 µm thick films. Diffusion coefficients for all studied vapor penetrants displayed a marked dependence on thickness spanning approximately two orders of magnitude for each respective vapor penetrant over the range 0.1–1.0 µm. Penetrant-induced relaxation behavior accounts for the majority of mass sorption at chemical activities of 0.2 and above for the C1-C6 alcohol vapors.

Monitoring antiplatelet therapy is critical in patients undergoing cardiac or neurologic stent placement to ensure adequate platelet suppression and prevent thrombosis. Light transmission aggregometry (LTA) using platelet-rich plasma (PRP) is the gold standard to assess platelet responsiveness to aspirin (ASA) and P2Y12 inhibitors (P2Y12-I). Other platforms for antiplatelet therapy monitoring employ whole-blood aggregometry (WBA) via electrical impedance (EA) or ELISA-based detection of urinary metabolites. The goal of this study was to evaluate the concordance of four antiplatelet therapy monitoring platforms. Blood and urine samples from 20 patients receiving antiplatelet therapy prior to neurologic stent placement were prospectively collected. Blood samples were analyzed by LTA using PRP on the Helena AggRAM and by WBA-EA using the Chrono-log Lumi-aggregometer to assess ASA and P2Y12-I response. For the LTA, the maximum amplitude (MA) of the platelet aggregation curve was determined using high-dose (HD) and low-dose (LD) ADP agonist for measuring P2Y12-I response and with arachidonic acid (AA) for ASA response. For the WBA, resistance (ohms) was measured with ADP for P2Y12-I response and with HD and LD collagen for ASA response. Whole-blood samples were also analyzed with the VerifyNow PRUTest to assess platelet response to P2Y12-I. Urine samples were analyzed with AspirinWorks. Concordance of antiplatelet response based on predefined cutoff values (eg, concordant = optimal/optimal, discordant = optimal/suboptimal), as well as correlation between actual units of measure, was determined. When comparing P2Y12-I response determined by LTA and WBA, overall concordance was 55% (correlation was r = 0.75 and 0.65 for HD and LD ADP, respectively). VerifyNow was concordant with LTA in 70% (r = 0.86 and 0.75 for HD and LD ADP, respectively) and with WBA in 45% (r = 0.57) of samples. When comparing ASA response between LTA and WBA, overall concordance was 70% (r = 0.09 and 0.19 for HD and LD collagen, respectively). AspirinWorks was concordant with LTA and WBA in 60% of samples (r = 0.32 for LTA; r = 0.08 LD collagen, r = 0.02 for HD collagen on WBA). In summary, concordance varied between 45% and 70% on the four antiplatelet therapy monitoring platforms. Testing of P2Y12 inhibition showed the best correlation between LTA HD ADP and VerifyNow (r = 0.86). When comparing WBA vs LTA, the strongest correlation was between LD ADP LTA and WBA (r = 0.75). Correlation with ASA inhibition was overall poor between the various assays (r ranging between 0.02 and 0.58). The results from this correlation study support the continued use of LTA with HD and LD ADP and AA; other testing methods can be used as adjuncts when LTA proves difficult to interpret.

Benzodiazepine drugs, through interaction with GABAAα1, GABAAα2,3, and GABAAα5 subunits, modulate cortical network oscillations, as reflected by a complex signature in the EEG power spectrum. Recent drug discovery efforts have developed GABAAα2,3-subunit-selective partial modulators in an effort to dissociate the side effect liabilities from the efficacy imparted by benzodiazepines. Here, we evaluated rat EEG and behavioral end points during dosing of nine chemically distinct compounds that we confirmed statistically to selectively to enhance GABAAα2,3-mediated vs. GABAAα1 or GABAAα5 currents in voltage clamped oocytes transfected with those GABAA subunits. These compounds were shown with in vivo receptor occupancy techniques to competitively displace [3H]flumazenil in multiple brain regions following peripheral administration at increasing doses. Over the same dose range, the compounds all produced dose-dependent EEG spectral power increases in the β- and and γ-bands. Finally, the dose range that increased γ-power coincided with that eliciting punished over unpunished responding in a behavioral conflict model of anxiety, indicative of anxiolysis without sedation. EEG γ-band power increases showed a significant positive correlation to in vitro GABAAα2,3 modulatory intrinsic activity across the compound set, further supporting a hypothesis that this EEG signature was linked specifically to pharmacological modulation of GABAAα2,3 signaling. These findings encourage further evaluation of this EEG signature as a noninvasive clinical translational biomarker that could ultimately facilitate development of GABAAα2,3-subtype-selective drugs for anxiety and potentially other indications.

Background: Exposure to red blood cell (RBC) alloantigens during pregnancy or transfusion can lead to the development of alloantibodies and result in transfusion-related complications, including hemolytic transfusion reactions and hemolytic disease of the fetus and newborn. However, the factors that regulate RBC alloimmunization remain incompletely understood. Several studies suggest that alterations in factors that regulate RBC clearance may impact RBC uptake and antigen presentation, directly influencing the likelihood of RBC alloimmunization. To test this, we directly examined the potential role of CD47, a master regulator of RBC removal previously shown to be altered during RBC senescence and cold storage. To accomplish this, we crossed transgenic mice that express the model HOD antigen (a fusion protein consisting of hen egg lysozyme fused to ovalbumin and human Duffy b) with CD47 knock out (KO) mice to generate HOD RBC donors with wild type, heterozygous or homozygous KO levels of CD47 and used these donors to define the impact of CD47 on antibody formation following RBC transfusion. Methods: HOD transgenic mice expressing the HOD antigen exclusively on RBCs were crossed with CD47-/- mice to produce HOD CD47+/- or HOD CD47-/- mice. HOD and CD47 levels were assessed by flow cytometric analysis using anti-HOD and anti-CD47 antibodies. HOD CD47+/+, HOD CD47+/- or HOD CD47-/- RBCs were transfused into C57BL6 recipients, followed by serum collection on days 14 and 28 post transfusion and evaluation of anti-HOD antibodies by flow cytometry crossmatch. To determine the CD4 T cell response to transfusion, TCR transgenics specific to ovalbumin (OTII) were labeled with CFSE, followed by adoptive transfer, transfusion of HOD CD47+/+, HOD CD47+/- or HOD CD47-/- RBCs and evaluation of T cell proliferation, activation and cytokine secretion. Cellular removal of HOD RBCs was determined by flow cytometric examination of CFSE-labeled HOD RBCs. Finally, antigen levels on HOD RBCs was determined by staining cells with anti-HEL antibodies followed by flow cytometric examination. All three groups were subjected to one-way ANOVA analysis with a p value Results: While HOD CD47+/+ RBCs expressed levels of CD47 comparable to WT RBCs, HOD CD47+/- RBCs exhibited significantly reduced CD47 levels (nearly half that observed on WT HOD RBCs) and HOD CD47-/-RBCs failed to express any detectable CD47 (p < 0.0001). Following transfusion, HOD CD47+/- and HOD CD47-/- RBCs produced significantly higher levels of IgG anti-HOD antibodies than HOD CD47+/+ RBCs on days 14 and 28 post-transfusion (p < 0.001). However, while HOD CD47-/- RBCs displayed increased clearance consistent with the possible enhancement of a CD4 T cell response (p < 0.0001), HOD CD47+/- RBCs failed to exhibit any different in clearance when compared to HOD CD47+/+ RBCs overtime. To examine the potential impact of differences in HOD RBC clearance on CD4 T cell activation, OTII T cell proliferation was evaluated. While HOD CD47-/- RBC transfusion resulted in significantly increased 33D1+ dendritic cell uptake, OTII proliferation, activation and cytokine secretion (p < 0.05), no difference in 33D1+ dendritic cell uptake or T cell response was observed following HOD CD47+/+ RBC or HOD CD47+/- RBC transfusion. Instead, HOD CD47+/- RBCs exhibited enhanced antigen removal, while also displaying an increased ability to activate HEL specific B cells when compared to HOD CD47+/+ or HOD CD47-/- RBC transfusion. Conclusions: These results demonstrate that alterations in CD47, which occur during normal RBC senescence and cold storage, directly influence RBC alloimmunization through different mechanisms depending on the extent of CD47 loss. While complete loss of CD47 results in enhanced RBC clearance, antigen presentation and CD4 T cell activation, reductions in CD47 to half WT levels failed to impact RBC clearance or T cell activation, but instead enhanced antigen specific B cell activation. These results demonstrate that even partial loss of CD47 is capable of significantly enhancing alloantibody formation completely independent of its role in regulating RBC clearance. In doing so, these findings provide novel insight into the role of CD47 as a key regulator of RBC alloimmunization. Disclosures Stowell: Grifols: Honoraria.

To evaluate the ethanol production performance of waxy sorghum hybrids and the effects of location and harvest year on ethanol yield, samples of four waxy sorghum hybrids collected from two Nebraska locations (Mead and Lincoln) in both 2009 and 2010 were tested for ethanol production in a dry-grind process. No significant difference (P = 0.216) in starch contents was observed among the four hybrids, but starch contents of the hybrids were significantly affected by growth location (P = 0.0001) and harvest year (P = 0.0258). Location, hybrid, and harvest year all had significant effects on ethanol fermentation efficiency in the dry-grind process. Lincoln sorghum samples showed higher (P = 0.022) ethanol fermentation efficiency (90.4%) than did Mead sorghum samples (90.0%). Sorghums harvested in 2010 had higher (P < 0.001) ethanol fermentation efficiency (91.1%) than those harvested in 2009 (89.3%). The 2009 sorghum flours had more amylose-lipid complexes than the 2010 samples did, and amylose-lipid...

Neuronal nicotinic acetylcholine receptor (nAChR) agonists active at the alpha-7 (α-7) receptor subtype are potential therapeutics for cognitive deficits in schizophrenia, Alzheimer's disease, and other mental disorders. SSR180711, an α-7 selective partial agonist, has been shown to improve preclinical cognition. A novel positron emission tomography (PET) radioligand, ¹¹C-Chiba1001, is a close analog of SSR180711. We labeled Chiba-1001 with tritium in order to evaluate its utility as a preclinical radioligand tool. In vitro, the binding affinity of [³H]Chiba-1001 at the α-7 receptor was low (K(d) = 120-180 nM) in both HEK239 cell membranes expressing human α-7 receptor and in native rat hippocampus membranes. The α-7 selective ligands AZD0328, ARR17779, and MLA did not inhibit [³H]Chiba-1001 binding (K(i) > 10,000 nM). In rat hippocampal membranes, Chiba-1001 and SSR180711 inhibited [³H]Chiba-1001 binding (K(i) = 220 and 230 nM, respectively), consistent with the literature reports. The in vivo binding profile of the radioligand was examined in normal rat, wild type mouse, and α-7 knockout mouse brain. We found that [³H]Chiba-1001 lacks adequate and specific brain regional uptake in rat and mouse brain. No significant inhibition of the radioligand binding was obtained following pretreatment of the animal with AZ11637326, AZD0328, or MLA. Our results indicate that [³H]Chiba-1001 has low affinity for α-7 nAChRs in vitro and poor α-7 regional and pharmacological selectivity in the rodent brain.

Herein we describe the discovery of compounds that are competitive antagonists of the CP101-606 binding site within the NR2B subtype of the NMDA receptor. The compounds identified do not possess phenolic functional groups such as those in ifenprodil and related analogs. Initial identification of hits in this series focused on a basic, secondary amine side chain which led to good potency, but also presented a hERG liability. Further modifications led to examples of non-basic replacements which demonstrated much less liability in this regard. Finally, one compound in the series, 6a, was tested in the mouse forced swim depression assay and found to show activity (sc 60 mg/kg).

Positron emission tomography (PET) antagonist ligands such as [(11)C]-raclopride are commonly used to study dopamine D2 receptor (D2) binding of antipsychotics. It has been suggested that agonist radioligands bind preferentially to the high-affinity state of D2 receptor and may provide a more relevant means of assessing D2 occupancy. The main objective of this study was to determine if D2 receptor occupancy (RO) could be differentiated with agonist and antagonist radioligands in vivo. Agonist radioligands [(3)H]-MNPA and [(3)H]-(+)-PHNO were synthesized and compared to antagonist [(3)H]-raclopride in the in vitro binding and in vivo occupancy studies. In vivo, unanesthetized rats were pretreated with quinpirole (full agonist), aripiprazole (partial agonist), or haloperidol (antagonist) prior to administration of the agonist or antagonist radioligand. All three pretreatment compounds showed equivalent dose-dependent D2 receptor occupancy in the rat striatum with each radioligand. The in vivo receptor occupancy results suggested that the binding of quinpirole, aripiprazole, and haloperidol to the high or low affinity state of the D2 receptor could not be differentiated using radiolabeled agonists or antagonists, presumably due to a predominance of high affinity states of the D2 receptor in vivo. This hypothesis was supported in part by the in vitro binding results. Our in vitro results show that [(3)H]-MNPA binds to D2S transfected CHO cell membranes at a single high affinity site. Displacement of [(3)H]-(+)-PHNO binding by quinpirole and elimination of most [(3)H]-(+)-PHNO binding by the guanine nucleotide GppNHp in striatal membranes suggest that the majority of D2 in striatal tissue is G-protein coupled. Together, these findings suggest that D2 agonist radioligands produce in vivo receptor occupancy comparable to [(3)H]-raclopride.

Background: Exposure to red blood cell (RBC) alloantigens during pregnancy or transfusion can lead to the development of alloantibodies and result in transfusion-related complications, like hemolytic transfusion reactions, or hemolytic disease of the fetus and newborn. Currently, antibody-mediated immune suppression (AMIS) is the only known methodology to actively inhibit RBC alloantibody formation. The best-known example of AMIS is Rh immune globulin, which is given to Rh(D) negative women to prevent the development of anti-D alloantibodies. Mouse models to elucidate the mechanism by which AMIS occurs have used mice genetically engineered to specifically express the human KEL antigen (KEL RBCs) or the Hel-Ova-Duffy antigen (HOD RBCs) on murine RBCs, and found that AMIS to these two antigens is dependent on antigen loss (also called antigen modulation). As RBCs express many antigens simultaneously, we sought to determine whether AMIS to one antigen can impact the immune response to a completely different antigen on the same RBC by generating mice that express both the KEL and HOD antigens (HOD x KEL RBCs). Methods: WT recipients received polyclonal anti-KEL antibody, a cocktail of two anti-HEL monoclonal antibodies, or PBS, followed by transfusion with WT and HOD x KEL donor RBCs. HOD x KEL RBCs were labeled with the lipophilic dye DiI prior to transfusion, while WT RBCs were labeled with the lipophilic dye DiO and served as a RBC tracer population. RBC survival and levels of detectable IgG, Kel antigen, Hel antigen, Duffy antigen, and complement (C3) on transfused cells were measured by flow cytometry at 10min, 1hr, 2hr, and 4hr, and on days 1, 2, 3, and 5 post-transfusion. Serum was collected on day 5 and analyzed for IgM antibody development by flow-crossmatch using KEL or HOD RBCs. Results: Anti-KEL and anti-HEL treated WT recipients demonstrated significant IgG deposition on transfused HOD x KEL RBCs at 10min post-transfusion. Levels of IgG on transfused RBCs decreased over time but did not correlate with complete RBC clearance. RBC survival was nearly 100% over 5 days in recipients passively immunized with anti-HEL antibodies, while a fraction of RBCs (~20%) were cleared within 4hr post-transfusion but not thereafter (survival plateaued at 80% thru day 5) in anti-KEL immunized recipients. Conversely, decreased bound IgG on transfused RBCs was found to correlate with a decrease in target antigen levels. KEL antigen levels decreased on transfused RBCs in the anti-KEL immunized recipients beginning at 1hr post transfusion, as compared to anti-HEL and PBS recipients. Similarly, HEL antigen expression decreased on transfused RBCs in the anti-HEL immunized recipients, but not in the anti-KEL or PBS recipients, demonstrating that passive immunization causes antigen modulation for the corresponding antigen only. C3 deposition was found to occur on transfused RBCs at 10min post-transfusion in the anti-KEL recipients that remained significantly increased at other time-points, but was not detected on RBCs in the anti-HEL or PBS recipients until day 3, when recipients develop IgM antibodies. Flow crossmatch of serum samples showed that anti-KEL treated recipients did not make anti-KEL IgM but did make anti-HOD IgM, while anti-HEL treated recipients did not make anti-HOD IgM but did make anti-KEL IgM. Conclusions: Although AMIS serves as the basis of a widely successful clinical intervention, the mechanism by which it occurs, including any impact on additional antigens, remains incompletely understood. Here we demonstrate that AMIS is antigen specific - that is, passively acquired antibody can inhibit the immune response only to the corresponding antigen. Specifically, murine RBCs expressing both the human and model RBC antigen KEL and HOD, respectively, demonstrate similar clearance kinetics, antigen modulation, complement deposition, and antibody development after transfusion into WT mice as is observed when KEL-only or HOD-only RBCs are used. Although it is unclear whether these findings apply to all RBC antigens and what relevance this holds for human patients, our study provides insight into the specificity of AMIS that may enlighten development of additional therapeutics based on this mode of immune suppression. Disclosures No relevant conflicts of interest to declare.

Deuterium and tritium labeling of carbohydrates and glycoconjugates has very wide applicability in the biochemical and biophysical fields. Carbohydrates function as receptors for a variety of hormones and play critical roles in cell recognition and differentiation. Deuterium labeled compounds are frequently utilized in the conformational analysis of oligosaccharides, as well as other glycoconjugates, to alleviate resonance overcrowding in 1 H NMR spectroscopy. Raney® nickel catalyzed 1 H→ 2 H ( 3 H) isotopic exchange is conducted under mild conditions using Ni catalysts, singular metal catalysts, or multi-phasic catalysts were ineffective or caused substrate decomposition. We have explored new digestion conditions for the preparation of highly active Raney nickel catalysts and have developed new protocols for the stereospecific incorporation of 2 H ( 3 H) in a wide variety of glycoconjugates using our facile C-H→C-D (C-T) exchange reactions. The regioselectivity of isotope incorporation is controlled by the judicious use of modified catalysts, co-solvents, and the isotopic source. formula. chem. either ultrasonic or microwave irradiation. The initial and overall rates of isotopic exchange are modulated by the presence of transition metals. Only the Raney-nickel® type alloys afforded stereospecific C- 1 H → C- 2 H isotopic exchange in an ultrasonic or microwave field. Typical supported precious metal catalysts, supported Reactions are easily performed using either a dedicated ultrasound probe, a slightly modified commercial microwave oven, or a dedicated commercial microwave synthesis unit. Research over the past several years is the subject of this attenuated review.

Chronic neutrophilic inflammation leads to oxidative damage, which may play an important role in the pathogenesis of cystic fibrosis lung disease. Bronchoalveolar lavage levels of the antioxidant glutathione are diminished in patients with cystic fibrosis. Here we evaluated the effects of glutathione aerosol on lower airway glutathione levels, lung function, and oxidative status. Pulmonary deposition of a radiolabeled monodisperse aerosol generated with a Pari LC Star nebulizer (Allergy Asthma Technology, Morton Grove, IL) connected to an AKITA inhalation device (Inamed, Gauting, Germany) was determined in six patients. In 17 additional patients bronchoalveolar lavage fluid was assessed before and after 14 days of inhalation with thrice-daily doses of 300 or 450 mg of glutathione. Intrathoracic deposition was 86.3 +/- 1.4% of the emitted dose. Glutathione concentration in lavage 1 hour postinhalation was increased three- to fourfold and was still almost doubled 12 hours postinhalation. FEV(1) transiently dropped after inhalation but increased compared with pretreatment values after 14 days (p0.001). This improvement was not related to the lavage content of oxidized proteins and lipids, which did not change with treatment. These results show that, using a new inhalation device with high efficacy, glutathione treatment of the lower airways is feasible. Reversion of markers of oxidative injury may need longer treatment, higher doses, or different types of antioxidants.

The objective of this paper is to study hydrogen assisted catalytic combustion of methane on platinum experimentally and numerically. In the experiment, we measure the exit temperatures of methane/hydrogen/air mixtures flowing at atmospheric pressure through platinum coated honeycomb channels. A single channel of this monolith is investigated numerically by a two-dimensional Navier-Stokes simulation including an elementary-step surface reaction mechanism. Furthermore, a one-dimensional time-dependent simulation of a stagnation flow configuration is performed to elucidate the elementary processes occurring during catalytic ignition in the mixtures studied. The dependence of the hydrogen assisted light-off of methane on hydrogen and on methane concentrations is discussed. The light-off is primarily determined by the catalyst temperature that is a result of the heat release due to catalytic hydrogen oxidation. Increasing hydrogen addition ensures light-off, decreasing hydrogen addition requires an increasing methane feed for light-off.

During acute inflammation, neutrophil recruitment into extravascular tissue requires neutrophil tethering and rolling on cytokine-activated endothelial cells (ECs), tight adhesion, crawling towards EC junctions and transendothelial migration (TEM). Following TEM, neutrophils must still traverse the subendothelial basement membrane and network of pericytes (PCs). Until recently, the contribution of the PC layer to neutrophil recruitment was largely ignored. Here we analyze human neutrophil interactions with interleukin (IL)-1β-activated human EC monolayers, PC monolayers and EC/PC bilayers in vitro. Compared to EC, PC support much lower levels of neutrophil binding (54.6% vs. 7.1%, respectively) and transmigration (63.7 vs. 8.8%, respectively) despite comparable levels of IL-8 (CXCL8) synthesis and display. Remarkably, EC/PC bilayers support intermediate levels of transmigration (37.7%). Neutrophil adhesion to both cell types is Mac-1-dependent and while ICAM-1 transduction of PCs increases neutrophil adhesion to (41.4%), it does not increase transmigration through PC monolayers. TEM, which increases neutrophil Mac-1 surface expression, concomitantly increases the ability of neutrophils to traverse PCs (19.2%). These data indicate that contributions from both PCs and ECs must be considered in evaluation of microvasculature function in acute inflammation.

Activity-dependent plasticity in rodent whisker barrel cortex was examined by means of high-resolution 2-deoxyglucose (2-DG) with immunohistochemical double labeling. Hamsters with all but one, two, or four follicles ablated on postnatal day 7 received 2-DG injections as adults. Autoradiograms of follicle-ablated animals showed heavy activation of the entire barrel field during normal behavior, despite the missing whiskers. The intensity of 2-DG labeling was significantly reduced if the whiskers spared after follicle ablation were trimmed prior to the 2-DG injection, demonstrating that the widespread activation was driven by the spared whiskers. This widespread metabolic activation of the adult barrel field after neonatal follicle ablation was in sharp contrast to the somatotopically appropriate 2-DG labeling in barrel fields of normal adults subject to acute trimming of most whiskers, but was similar to that seen in normal adult animals with all whiskers intact. The results demonstrate large-scale plasticity of barrel circuitry following neonatal sensory deprivation, and provide a powerful functional anatomical setting to investigate underlying mechanisms.

Herein, we describe the discovery of inhibitors of norepinephrine (NET) and dopamine (DAT) transporters with reduced activity relative to serotonin transporters (SERT). Two compounds, 8b and 21a, along with nomifensine were tested in a rodent receptor occupancy study and demonstrated dose-dependent displacement of radiolabeled NET and DAT ligands. These compounds were efficacious in a rat forced swim assay (model of depression) and also had activity in rat spontaneous locomotion assay.

The positive allosteric modulator (PAM) binding site for metabotropic glutamate receptor subtype 5 (mGlu5) lacks a readily available radio-labeled tracer fordetailed structure-activity studies. This communication describes a selective mGlu5 compound, 7-methyl-2-(4-(pyridin-2-yloxy)benzyl)-5-(pyridin-3-yl)isoindolin-1-one (PBPyl) that binds with high affinity to human mGlu5 and exhibits functional PAM activity. Analysis of PBPyl by FLIPR revealed an EC50 of 87 nM with an 89% effect in transfected HEK293 cells and an EC50 of 81 nM with a 42% effect in rat primary neurons. PBPyl exhibited 5-fold higher functional selectivity for mGlu5 in a full mGlu receptor panel. Unlabeled PBPyl was tested for specific binding using a liquid chromatography mass spectrometry (LC/MS/MS)-based filtration binding assay and exhibited 40% specific binding in recombinant membranes, a value higher than any candidate compound tested. In competition binding studies with [3H]MPEP, the mGlu5 receptor negative allosteric modulator (NAM), PBPyl exhibited a k i value of 34 nM. PBPyl also displaced [3H]ABP688, a mGluR5 receptor NAM, in tissue sections from mouse and rat brain using autoradiography. Areas of specific binding included the frontal cortex, striatum and nucleus accumbens. PBPyl was radiolabeled to a specific activity of 15 Ci/mmol and tested for specific binding in a filter plate format. In recombinant mGlu5b membranes, [3H] PBPyl exhibited saturable binding with a Kd value of 18.6 nM. In competition binding experiments, [3H] PBPyl was displaced by high affinity mGlu5 positive and negative modulators. Further tests showed that PBPyl displays less than optimal characteristics as an in vivo tool, including a high volume of distribution and ClogP, making it more suitable as an in vitro compound. However, as a first report of direct binding of an mGlu5 receptor PAM, this study offers value toward the development of novel PET imaging agents for this important therapeutic target. Synapse, 2013. © 2012 Wiley Periodicals, Inc.

Αlpha-7 neuronal nicotinic receptors (NNRs) are considered targets for cognitive enhancement in schizophrenia and Alzheimer's disease. AZD0328 is an alpha-7 NNR partial agonist that enhances cognition in rodents and nonhuman primates at sub-microgram to microgram doses. We hypothesized that increased expression of the alpha-7 receptor contributes to this beneficial activity at low doses and tested this by examining the effect of AZD0328 using in vivo and ex vivo binding, RT-PCR and cognitive function in rodents. AZD0328 (0.00178 mg/kg) was subcutaneously administered to mice 4, 24, 48 and 72 hours prior to testing in novel object recognition and produced a significant increase in cognition at 4, 24 and 48 h post-dosing. In vivo binding was examined in rat brain using [(3)H]AZ11637326 and there was a dose-dependent reduction in receptor binding at higher doses of AZD0328 (0.001-3 mg/kg), and a second alpha-7 partial agonist, SSR180711 (0.01-30 mg/kg). Lower doses of both compounds (0.0001 mg/kg) produced a significant increase in binding of [(3)H]AZ11637326. Ex vivo binding using [(125)I]-α-bungarotoxin, showed a significant increase in receptor number (B(max.)) in the frontal cortex or hippocampus with no significant effect on receptor affinity (K(d)) 2 h post administration of AZD0328. [(3)H]AZ11637326 administered 1.5 h following AZD0328 produced a significant increase in specific binding in rat brain regions. We found that the effect on receptor number was long-lasting, with [(125)I]-α-bungarotoxin binding increased in rats given AZD0328 for 2-48 h, but this was not accompanied by increased mRNA synthesis. SSR180711 produced a similar increase in B(max.) and specific binding with no effect on K(d). Therefore, trace dose of alpha-7 partial agonists has rapid onset and produces a profound, sustained effect on novel object recognition in mice that corresponds by dose to an increase in receptor number in rat brain. These findings provide an explanation for the acute and sustained benefit of alpha-7 receptor activation in working memory in nonhuman primates and guidance for drug development initiatives and treatment regimens for nicotinic partial agonists.

The alpha-7 neuronal nicotinic receptor is a novel pharmacological target for psychiatric and cognitive disorders. Selective radiotracer tools for pre-clinical receptor occupancy can facilitate the interpretation of the biological actions of small molecules at a target receptor. We discovered a high affinity nicotinic alpha-7 subtype-selective ligand, AZ11637326, with physical–chemical and pharmacokinetic properties suitable for an in vivo radioligand tool. [3H]AZ11637326 synthesis by tritiodehalogenation of the corresponding tribromide precursor yielded a high specific activity radiotracer with high affinity alpha-7 receptor binding in the rat hippocampus determined by autoradiography (Kd = 0.2 nM). When [3H]AZ11637326 was administered to rats by intravenous bolus, rapid uptake was measured in the brain followed by a 3–4 fold greater specific binding in regions containing the alpha-7 receptor (frontal cortex, hippocampus, hypothalamus and midbrain) when compared to non-target regions (striatum and cerebellum). Systemic administration of the high affinity alpha-7 receptor antagonist, methyllycaconitine (MLA), or pretreatment with alpha-7 selective agonists (AR-R17779, PyrQTC, DBCO-4-POM, and DBCO-3-POM) significantly blocked the alpha-7 specific binding of [3H]AZ11637326 in the rat brain. The rank order of ligand ED50 values for in vivo alpha-7 receptor occupancy in rat hippocampus was: DBCO-4-POM > DBCO-3-POM ∼ MLA > PyrQTC > AR-R17779. The occupancy affinity shift was consistent with in vitro binding affinity in autoradiography. Our studies established the optimal conditions for [3H]AZ11637326 in vivo specific binding in the rat brain and support the use of [3H]AZ11637326 as a pre-clinical tool for assessment of novel alpha-7 compounds in drug discovery.

Single-walled carbon nanotubes have gained enormous popularity due to a variety of potential applications which will ultimately lead to increased human and environmental exposure to these nanoparticles. This study was carried out in order to evaluate the inflammatory response of immortalised and primary human lung epithelial cells (A549 and NHBE) to single-walled carbon nanotube samples (SWCNT). Special focus was placed on the mediating role of lung surfactant on particle toxicity. The toxicity of SWCNT dispersed in cell culture medium was compared to that of nanotubes dispersed in dipalmitoylphosphatidylcholine (DPPC, the main component of lung lining fluid). Exposure was carried out for 6 to 48 h with the latter time-point showing the most significant responses. Moreover, exposure was performed in the presence of the pro-inflammatory stimulus tumour necrosis factor-alpha (TNF-alpha) in order to mimic exposure of stimulated cells, as would occur during infection. Endpoints evaluated included cell viability, proliferation and the analysis of inflammatory mediators such as interleukin (IL)-8, IL-6, TNF-alpha and macrophage chemoattractant protein-1 (MCP-1). Crocidolite asbestos was included as a well characterised, toxic fibre control. The results of this study showed that HiPco SWCNT samples suppress inflammatory responses of A549 and NHBE cells. This was also true for TNF-alpha stimulated cells. The use of DPPC improved the degree of SWCNT dispersion in A549 medium and in turn, leads to increased particle toxicity, however, it was not shown to modify NHBE cell responses.

Alterations in renal eicosanoid levels have been postulated as a factor in cyclosporin A (CSA) nephrotoxicity. The effects of CSA on renal eicosanoid excretion in rheumatoid arthritis were studied over a 24-week period, during which treatment with nonsteroidal antiinflammatory drugs was discontinued. The initial dosage of CSA was 4 mg/kg/day; at week 24, the mean dosage of CSA was 3.9 mg/kg/day. At week 24, the mean (+/- SD) serum creatinine level (1.04 +/- 0.24 mg/dl) was 32% above the baseline value; renal blood flow had decreased by 21% (P less than 0.03) and the glomerular filtration rate had decreased by 16%. There was a significant increase (P less than 0.03) in the 2,3-dinor thromboxane B2 level at week 2, but there was no significant change in the levels of the other eicosanoids. This study demonstrates that after CSA treatment, there is a selective increase in a thromboxane metabolite that parallels an increase in renal vascular resistance, even in the absence of nonsteroidal antiinflammatory drugs, and with unimpaired formation of other vasodilator eicosanoids.

The European physical journal / Web of Conferences 93, 05003 (2015). doi:10.1051/epjconf/20159305003, Published by EDP Sciences, Les Ulis

We used optical imaging of intrinsic cortical signals, elicited by whisker stimulation, to define areas of activation in primary sensory cortex of normal hamsters and hamsters subjected to neonatal follicle ablation at postnatal day seven (P7). Follicle ablations were unilateral, and spared either C-row whiskers or the second whisker arc. This study was done to determine if the intrinsic cortical connectivity pattern of the barrel cortex, established during the critical period, affects the process of representational plasticity that follows whisker follicle ablation. Additionally, we tested the ability to monitor such changes in individual cortical whisker representations using intrinsic signal imaging. Stimulation of a single whisker yielded peak activation of a barrel-sized patch in the somatotopically appropriate location in normal cortex. In both row and arc-spared animals, functional representations corresponding to spared follicles were significantly stronger and more oblong than normal. The pattern of activation differed in the row-sparing and arc-sparing groups, in that the expansion was preferentially into deprived, not spared areas. Single whisker stimulation in row-spared cases preferentially activated the corresponding barrel arc, while stimulation of one whisker in arc-spared cases produced elongated activation down the barrel row. Since whisker deflection normally has a net inhibitory effect on neighboring barrels, our data suggest that intracortical inhibition fails to develop normally in deprived cortical columns. Because thalamocortical projections are not affected by follicle ablation after P7, we suggest that the effects we observed are largely cortical, not thalamocortical.

Imaging agents targeting beta-amyloid (Abeta) may be useful for diagnosis and treatment of patients with Alzheimer's disease (AD). Compounds 3e and 4e are fluorinated stilbene derivatives displaying high binding affinities for Abeta plaques in AD brain homogenates (Ki = 15 +/- 6 and 5.0 +/- 1.2 nM, respectively). In vivo biodistributions of [18F]3e and [18F]4e in normal mice exhibited excellent brain penetrations (5.55 and 9.75% dose/g at 2 min), and rapid brain washouts were observed, especially for [18F]4e (0.72% dose/g at 60 min). They also showed in vivo plaque labeling in APP/PS1 or Tg2576 transgenic mice, animal models for AD. Autoradiography of postmortem AD brain sections and AD homogenate binding studies confirmed the selective and specific binding properties to Abeta plaques. In conclusion, the preliminary results strongly suggest that these fluorinated stilbene derivatives, [18F]3e and [18F]4e, are suitable candidates as Abeta plaque imaging agents for studying patients with AD.

This paper describes a novel series of 18 F-labeled polyethyleneglycol (PEG)-stilbene derivatives as potential β-amyloid (Aβ) plaque-specific imaging agents for positron emission tomography (PET). In these series of compounds, 18 F is linked to the stilbene through a PEG chain, of which the number of ethoxy groups ranges from 2 to 5. The purpose of adding PEG groups is to lower the lipophilicity and improve bioavailability. The syntheses of the "cold" compounds and the 18 F-labeled PEG stilbene derivatives are successfully achieved. All of the fluorinated stilbenes displayed high binding affinities in an assay using postmortem AD brain homogenates ( K i =2.9–6.7 nM). Labeling was successfully performed by a substitution of the mesylate group of 10a–d by [ 18 F]fluoride giving the target compounds [ 18 F] 12a–d (EOS, specific activity, 900–1500 Ci/mmol; radiochemical purity >99%). In vivo biodistribution of these novel 18 F ligands in normal mice exhibited excellent brain penetrations and rapid washouts after an intravenous injection (6.6–8.1 and 1.2–2.6 %dose/g at 2 and 60 min, respectively). Autoradiography of postmortem AD brain sections of [ 18 F] 12a–d confirmed the specific binding related to the presence of Aβ plaques. In addition, in vivo plaque labeling can be clearly demonstrated with these 18 F-labeled agents in transgenic mice (Tg2576), a useful animal model for Alzheimer's disease. In conclusion, the preliminary results strongly suggest these fluorinated PEG stilbene derivatives are suitable candidates as Aβ plaque imaging agents for studying patients with Alzheimer's disease.

In ambient aerosols, ultrafine particles (UFP) and their agglomerates are considered to be major factors contributing to adverse health effects. Reactivity of agglomerated UFP of elemental carbon (EC), Printex 90, Printex G, and diesel exhaust particles (DEP) was evaluated by the capacity of particles to oxidize methionine in a cell-free in vitro system for determination of their innate oxidative potential and by alveolar macrophages (AMs) to determine production of arachidonic acid (AA), including formation of prostaglandin E2 (PGE2), leukotriene B4 (LTB4), reactive oxygen species (ROS), and oxidative stress marker 8-isoprostane. EC exhibiting high oxidative potential induced generation of AA, PGE2, LTB4, and 8-isoprostane in canine and human AMs. Printex 90, Printex G, and DEP, showing low oxidative capacity, still induced formation of AA and PGE2, but not that of LTB4 or 8-isoprostane. Aging of EC lowered oxidative potential while still inducing production of AA and PGE2 but not that of LTB4 and 8-isoprostane. Cellular ROS production was stimulated by all particles independent of oxidative potential. Particle-induced formation of AA metabolites and ROS was dependent on mitogen-activated protein kinase kinase 1 activation of cytosolic phospholipase A2 (cPLA2) as shown by inhibitor studies. In conclusion, cPLA2, PGE2, and ROS formation was activated by all particle types, whereas LTB4 production and 8-isoprostane were strongly dependent on particles' oxidative potential. Physical and chemical parameters of particle surface correlated with oxidative potential and stimulation of AM PGE2 and 8-isoprostane production.

Deposition of beta-amyloid (Abeta) plaques in the brain is likely linked to the pathogenesis of Alzheimer's disease (AD). Developing specific Abeta aggregate-binding ligands as in vivo imaging agents may be useful for diagnosis and monitoring the progression of AD. We have prepared a thioflavin derivative, 6-iodo-2-(4'-dimethylamino-)phenyl-imidazo[1,2-a]pyridine, IMPY, which is readily radiolabeled with 125I/123I for binding or single-photon emission computerized tomography (SPECT) imaging studies. Characterization of [125I]IMPY binding to plaque-like structures was evaluated in double transgenic PSAPP mice. [125I]IMPY labeled Abeta plaques in transgenic mouse brain sections, and the labeling was consistent with fluorescent staining and Abeta-specific antibody labeling. Significant amounts of Abeta plaques present in the cortical, hippocampal, and entorhinal regions of the transgenic mouse brain were clearly detected with [125I]IMPY via ex vivo autoradiography. In contrast, [125I]IMPY showed little labeling in the age-matched control mouse brain. Tissue homogenate binding further corroborated the Abeta plaque-specific distribution in various brain regions of transgenic mouse, and correlated well with the known density of Abeta deposition. Using a tissue dissection technique, [125I]IMPY showed a moderate increase in the cortical region of transgenic mice as compared to the age-matched controls. In vitro blocking of [125I]IMPY by "carrier" observed via autoradiography in mouse brain sections was not replicated by an in vivo blocking experiment in living TT mouse brain. The failure was most likely due to a significant carrier effect, which slows down the tracer in vivo metabolism, leading to an increased brain uptake. Taken together, these data indicate that [123I]IMPY is a potentially useful SPECT imaging agent for in vivo labeling of Abeta plaques in the living brain.

A two-step process including standard ellipsometric and quasi-Brewster angle measurements has been employed to identify the process variations originating from coating and/or polished CaF2 substrates of AR coated CaF2 deep-ultraviolet (DUV) fluoride components.

Low-energy-plasma-ion treatment has been employed to identify color centers on CaF2 components originating from fluorine depletion on CaF2 surfaces. The initial time and saturation peak absorption depends on the surface processing conditions.

Two aldolases from the alga Cyanophora paradoxa (Glaucocystophyta) can be separated by chromatography on diethylaminoethyl-Fractogel. The two aldolases are inhibited by 1 mM ethylene-diaminetetraacetate (EDTA) and, therefore, are class II aldolases. When cells of C. paradoxa were fractionated, one aldolase was associated with the cytosol fraction and the other was associated with the cyanoplast fraction. The Km(fructose-1,6-bisphosphate) was 600 [mu]M for the cytosolic aldolase and 340 [mu]M for the cyanoplast aldolase. The activity of the cytosolic aldolase was increased up to 4-fold by 100 mM K+ and slightly inhibited by Li+ and Cs+, whereas the cyanoplast aldolase was not affected by these ions. Inactivation by 1 mM EDTA could be partly restored by the addition of Co2+ or Mn2+ and to a lesser extent by Zn2+ or Mg2+. The molecular masses of the native cytosolic and cyanoplast aldolases are about 90 and 85 kD, respectively, as estimated by velocity centrifugation in sucrose gradients. Implications for the evolution of class I and II aldolases in chloroplasts of higher plants and algae will be discussed.

Rhabdomeres are substantially smaller and visual pigment is nearly eliminated when Drosophila are carotenoid-deprived from egg to adult. Rhabdomeres enlarge and visual pigment increases with carotenoid replacement in adults using carrot juice. We used a monoclonal antibody to the opsin in R1-6 receptors in the compound eye to further quantify opsin recovery in such carotenoid replacement therapy. Density of immunogold, specific to R1-6 (vs. R7), increases between days 1 and 3 of replacement as visual pigment and rhabdomeres recover. In summary, visual pigment, opsin and the opsin-containing organelle recover during carotenoid replacement therapy in carotenoid-deprived Drosophila.

A heat-stable protein has been detected in Saccharomyces cerevisiae which inhibits mitochondrial ATPase activity. The protein inhibitor has been isolated from extracts prepared by brief heat treatment of unbroken cell suspensions. The isolated inhibitor is a small basic protein (molecular weight close to 7000, isoelectric proint 9.05) devoid of tryptophan, tyrosine, and cysteine as well as proline. The NHP2-terminal amino acid is serine. The ultraviolet absorption spectrum shows the vibrational fine structure of the phenyl-alanine band. Like the ATPase inhibitor from bovine heart mitochondria the yeast inhibitor is rapidly destroyed by trypsin. It is also inactivated by the yeast proteinases A and B. Radioimmunological analysis indicates that the inhibitor is synthesized on cytoplasmic ribosomes. Its accumulation seems to be connected to the formation of the mitochondrial ATPase complex, since its specific activity is greatly reduced both in extracts obtained from the F1-ATPase-deficient nuclear mutant pet 936 and from the cytoplasmic petite mutant D 273-10B-1.

The convenient preparation of some methyl, ethyl, vinyl and phenyl halo-arsines and -stibines by the action of the corresponding hydrocarbon halides on elementary arsenic and bismuth is described. Suitable conditions vary with the halide employed: methyl bromide and chloride react satisfactorily at 350–375° in the presence of copper as catalyst, but vinyl bromide and chloride require a temperature at least 100° above this. Methyl iodide reacts at 280°, but the yields are poor. Silver is a superior catalyst for the reaction of bromobenzene with arsenic. Bismuth gave no isolable product with methyl chloride, but methyl bromide gave a low yield of methyldibromobismuthine.

Organic substituted diphosphine disulphides are reduced by tributylphosphine, when heated in the ratio 1:2 to give excellent yields of tetra-alkyldiphosphines. In this reaction, tetra-alkyldiphosphine disulphides of the type RR′P(S)-(S)PRR′ yield two isomeric diphosphines, the structure of which has been proved without question by nuclear magnetic resonance (n.m.r.) and chemical reactions. It is believed this to be the first time that such isomerism has been observed with triply connected phosphorus compounds. If tetra-alkyldiphosphine disulphides are caused to react with tributylphosphine in the ratio 1:1 at elevated temperatures a new class of phosphorus compounds, the tetra-alkyldiphosphine monosulphides are produced. The structures and some of the chemical reactions of these compounds are discussed. A number of new n.m.r. chemical shifts are reported.