Safety and immunogenicity of a 20-valent pneumococcal conjugate vaccine coadministered with quadrivalent influenza vaccine: A phase 3 randomized trial

INTRODUCTION

Older adults are at increased risk of adverse outcomes from pneumococcal disease and influenza infections. Vaccination is an established strategy for preventing both illnesses. This study evaluated coadministration of 20-valent pneumococcal conjugate vaccine (PCV20) and an adjuvanted quadrivalent inactivated influenza vaccine (QIV).

METHODS

This phase 3, randomized, double-blind, multicenter study included 1796 US adults ≥ 65 years of age randomized 1:1 to receive either PCV20 and QIV followed 1 month later by saline (Coadministration group) or QIV and saline followed 1 month later by PCV20 (Separate Administration group). Primary immunogenicity objectives were to show noninferiority of PCV20 and QIV coadministration compared with separate administration of either vaccine based on serotype-specific opsonophagocytic activity (OPA) titers for PCV20 and strain-specific hemagglutination inhibition assay (HAI) titers for QIV. Safety endpoints included local reactions, systemic events, and adverse events (AEs).

RESULTS

Noninferiority for pneumococcal and influenza antibody responses (lower bound 95 % CI of the OPA and HAI geometric mean ratios of > 0.5 and > 0.67, respectively) was shown for the Coadministration group compared with the Separate Administration group for all 20 pneumococcal serotypes and all 4 influenza vaccine strains. Local reactions and systemic events were mostly mild or moderate in severity across groups; injection site pain was the most frequent local reaction, and fatigue was the most frequent systemic event. Mild and moderate fatigue were reported more frequently after PCV20 and QIV coadministration compared with separate administration (mild, 20.0 % vs 10.8 %-12.6 %; moderate, 12.3 % vs 8.4 %-9.6 %); this was not considered clinically significant. AE reporting rates were similar across groups, and no serious AEs were considered vaccination-related.

CONCLUSIONS

Immune responses after coadministration of PCV20 and QIV were noninferior to separate administration of either vaccine. The PCV20 safety profile was similar when given together with or after QIV. These findings support PCV20 and QIV coadministration.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT04526574.

Pivotal Phase 3 Randomized Clinical Trial of the Safety, Tolerability, and Immunogenicity of 20-Valent Pneumococcal Conjugate Vaccine in Adults 18 Years and Older

BACKGROUND

Pneumococcal conjugate vaccines (PCVs) have significantly reduced pneumococcal disease, but disease from non-PCV serotypes remains. Safety, tolerability, and immunogenicity of a 20-valent PCV (PCV20) were evaluated.

METHODS

This pivotal phase 3, randomized, double-blind study enrolled adults into 3 age groups (≥60, 50-59, 18-49 years) at US and Swedish sites. Participants were randomized to receive one PCV20 or PCV13 dose. After 1 month, participants ≥60 years also received one dose of saline or 23-valent polysaccharide vaccine (PPSV23). Safety assessments included local reactions, systemic events, adverse events, serious adverse events, and newly diagnosed chronic medical conditions. Opsonophagocytic activity (OPA) geometric mean titers (GMTs) 1 month after PCV20 were compared to 13 matched serotypes after PCV13 and to 7 additional serotypes after PPSV23 in participants ≥60 years; noninferiority was declared if lower bound of the 2-sided 95% CI for OPA GMT ratio (PCV20/saline:PCV13/PPSV23 group) was >0.5. PCV20-elicited immune responses in younger participants were also bridged to those in 60-64-year-olds.

RESULTS

Severity and frequency of prompted local reactions and systemic events were similar after PCV20 or PCV13; no safety concerns were identified. Primary immunogenicity objectives were met, with immune responses after PCV20 noninferior to 13 matched serotypes after PCV13 and to 6 additional PPSV23 serotypes in participants ≥60 years; serotype 8 missed the statistical noninferiority criterion. PCV20 induced robust responses to all 20 vaccine serotypes across age groups.

CONCLUSIONS

PCV20 was safe and well tolerated, with comparable immunogenicity to PCV13/PPSV23. PCV20 is anticipated to expand protection against pneumococcal disease in adults.

A trial to evaluate the safety and immunogenicity of a 20-valent pneumococcal conjugate vaccine in populations of adults ≥65 years of age with different prior pneumococcal vaccination

INTRODUCTION

A 20-valent pneumococcal conjugate vaccine, PCV20, was developed to expand protection against vaccine-preventable pneumococcal disease. PCV20 contains the components of the 13-valent pneumococcal conjugate vaccine, PCV13, and includes capsular polysaccharide conjugates for 7 additional serotypes. Thus, PCV20 may cover those additional serotypes in individuals previously vaccinated with PCV13 or provide benefits of immunization with a conjugate vaccine to individuals previously immunized with a pneumococcal polysaccharide vaccine. This study described the safety and immunogenicity of PCV20 in adults ≥65 years of age with prior pneumococcal vaccination.

METHODS

This phase 3, multicenter, randomized, open-label study was conducted in the United States and Sweden. Adults ≥65 years of age were enrolled into 1 of 3 cohorts based on their prior pneumococcal vaccination history (23-valent pneumococcal polysaccharide vaccine [PPSV23], PCV13, or both PCV13 and PPSV23). Participants were randomized 2:1 within their cohort to receive a single dose of PCV20 or PCV13 in those with prior PPSV23 only, and PCV20 or PPSV23 in those with prior PCV13 only; all participants with prior PCV13 and PPSV23 received PCV20. Safety was assessed by prompted local reactions within 10 days, systemic events within 7 days, adverse events (AEs) within 1 month, and serious AEs (SAEs) and newly diagnosed chronic medical conditions (NDCMCs) within 6 months after vaccination. Immune responses 1 month after PCV20 were assessed.

RESULTS

The percentages of participants reporting local reactions, systemic events, and AEs after PCV20 administration were similar across cohorts and comparable with the PCV13 and PPSV23 control groups. SAE and NDCMC rates were low in all groups. Robust immune responses, including opsonophagocytic antibody responses, to the 20 vaccine serotypes were observed 1 month after PCV20 regardless of prior pneumococcal vaccination.

CONCLUSIONS

PCV20 was well tolerated and immunogenic in adults ≥65 years of age previously vaccinated with different pneumococcal vaccine regimens. Clinicaltrials.gov NCT03835975.

REGEN-COV Antibody Combination and Outcomes in Outpatients with Covid-19

BACKGROUND

In the phase 1-2 portion of an adaptive trial, REGEN-COV, a combination of the monoclonal antibodies casirivimab and imdevimab, reduced the viral load and number of medical visits in patients with coronavirus disease 2019 (Covid-19). REGEN-COV has activity in vitro against current severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants of concern.

METHODS

In the phase 3 portion of an adaptive trial, we randomly assigned outpatients with Covid-19 and risk factors for severe disease to receive various doses of intravenous REGEN-COV or placebo. Patients were followed through day 29. A prespecified hierarchical analysis was used to assess the end points of hospitalization or death and the time to resolution of symptoms. Safety was also evaluated.

RESULTS

Covid-19-related hospitalization or death from any cause occurred in 18 of 1355 patients in the REGEN-COV 2400-mg group (1.3%) and in 62 of 1341 patients in the placebo group who underwent randomization concurrently (4.6%) (relative risk reduction [1 minus the relative risk], 71.3%; P<0.001); these outcomes occurred in 7 of 736 patients in the REGEN-COV 1200-mg group (1.0%) and in 24 of 748 patients in the placebo group who underwent randomization concurrently (3.2%) (relative risk reduction, 70.4%; P = 0.002). The median time to resolution of symptoms was 4 days shorter with each REGEN-COV dose than with placebo (10 days vs. 14 days; P<0.001 for both comparisons). REGEN-COV was efficacious across various subgroups, including patients who were SARS-CoV-2 serum antibody-positive at baseline. Both REGEN-COV doses reduced viral load faster than placebo; the least-squares mean difference in viral load from baseline through day 7 was -0.71 log10 copies per milliliter (95% confidence interval [CI], -0.90 to -0.53) in the 1200-mg group and -0.86 log10 copies per milliliter (95% CI, -1.00 to -0.72) in the 2400-mg group. Serious adverse events occurred more frequently in the placebo group (4.0%) than in the 1200-mg group (1.1%) and the 2400-mg group (1.3%); infusion-related reactions of grade 2 or higher occurred in less than 0.3% of the patients in all groups.

CONCLUSIONS

REGEN-COV reduced the risk of Covid-19-related hospitalization or death from any cause, and it resolved symptoms and reduced the SARS-CoV-2 viral load more rapidly than placebo. (Funded by Regeneron Pharmaceuticals and others; ClinicalTrials.gov number, NCT04425629.).

Prospects for observing and localizing gravitational-wave transients with Advanced LIGO, Advanced Virgo and KAGRA

We present our current best estimate of the plausible observing scenarios for the Advanced LIGO, Advanced Virgo and KAGRA gravitational-wave detectors over the next several years, with the intention of providing information to facilitate planning for multi-messenger astronomy with gravitational waves. We estimate the sensitivity of the network to transient gravitational-wave signals for the third (O3), fourth (O4) and fifth observing (O5) runs, including the planned upgrades of the Advanced LIGO and Advanced Virgo detectors. We study the capability of the network to determine the sky location of the source for gravitational-wave signals from the inspiral of binary systems of compact objects, that is binary neutron star, neutron star-black hole, and binary black hole systems. The ability to localize the sources is given as a sky-area probability, luminosity distance, and comoving volume. The median sky localization area (90% credible region) is expected to be a few hundreds of square degrees for all types of binary systems during O3 with the Advanced LIGO and Virgo (HLV) network. The median sky localization area will improve to a few tens of square degrees during O4 with the Advanced LIGO, Virgo, and KAGRA (HLVK) network. During O3, the median localization volume (90% credible region) is expected to be on the order of 10 5 , 10 6 , 10 7 Mpc 3 for binary neutron star, neutron star-black hole, and binary black hole systems, respectively. The localization volume in O4 is expected to be about a factor two smaller than in O3. We predict a detection count of 1 - 1 + 12 ( 10 - 10 + 52 ) for binary neutron star mergers, of 0 - 0 + 19 ( 1 - 1 + 91 ) for neutron star-black hole mergers, and 17 - 11 + 22 ( 79 - 44 + 89 ) for binary black hole mergers in a one-calendar-year observing run of the HLV network during O3 (HLVK network during O4). We evaluate sensitivity and localization expectations for unmodeled signal searches, including the search for intermediate mass black hole binary mergers.

Crystal structures of two 1,3-thia-zolidin-4-one derivatives featuring sulfide and sulfone functional groups

The crystal structures of two closely related compounds, 1-cyclo-hexyl-2-(2-nitro-phen-yl)-1,3-thia-zolidin-4-one, C15H18N2O3S, (1) and 1-cyclo-hexyl-2-(2-nitro-phen-yl)-1,3-thia-zolidin-4-one 1,1-dioxide, C15H18N2O5S, (2), are presented. These compounds are comprised of three types of rings: thia-zolidinone, nitrophenyl and cyclo-hexyl. In both structures, the rings are close to mutually perpendicular, with inter-planar dihedral angles greater than 80° in each case. The thia-zol-idinone rings in both structures exhibit envelope puckering with the S atom as flap and the cyclo-hexyl rings are in their expected chair conformations. The two structures superpose fairly well, except for the orientation of the nitro groups with respect to their host phenyl ring, with a difference of about 10° between 1 and 2. The extended structure of 1 has two kinds of weak C-H⋯O inter-actions, giving rise to a closed ring formation involving three symmetry-related mol-ecules. Structure 2 has four C-H⋯O inter-actions, two of which are exclusively between symmetry-related thia-zolidinone dioxide moieties and have a parallel 'give-and-take-fashion' counterpart. In the other two inter-actions, the nitrophenyl ring and the cyclo-hexane ring each offer an H atom to the two O atoms on the sulfone group. Additionally, a C-H⋯π inter-action between a C-H group of the cyclo-hexane ring and the nitrophenyl ring of an adjacent mol-ecule helps to consolidate the structure.

Crystal structures of two thia-zolidinone derivatives bearing a tri-chloro-methyl substituent at the 2-position

The title compounds 2-tri-chloro-methyl-3-phenyl-1,3-thia-zolidin-4-one (C10H8Cl3NOS), 1 and 3-(4-chloro-phen-yl)-2-tri-chloro-methyl-1,3-thia-zolidin-4-one (C10H7Cl4NOS) 2, are structurally related with one atom substitution difference in the para position of the benzene ring. In both structures, the thia-zolidinone ring adopts an envelope conformation with the S atom as the flap. The dihedral angles between the rings [48.72 (11) in 1 and 48.42 (9)° in 2] are very similar and the mol-ecules are almost superimposable. In both crystal structures, C-H⋯O 'head-to-tail' inter-actions between the chiral carbon atoms and the thia-zolidinone oxygen atoms result in infinite monochiral chains along the direction of the shortest unit-cell parameter, namely a in 1 and b in 2. C-H⋯π inter-actions between the thia-zolidinone carbon atom at the 4-position and the phenyl ring of the neighboring enanti-omer also help to stabilize the packing in each case, although the crystals are not isostructural.

Immunogenicity and safety of a cell culture-based quadrivalent influenza vaccine in adults: A Phase III, double-blind, multicenter, randomized, non-inferiority study

Quadrivalent influenza vaccines (QIVs), which include both B lineage strains, are expected to provide broader protection than trivalent influenza vaccines (TIVs). The non-inferiority, immunogenicity, and safety of a cell culture-based investigational QIVc and 2 TIVs (TIV1c, TIV2c), in adults (≥18 y), were evaluated in this Phase III, double-blind, multicenter study. A total of 2680 age-stratified subjects were randomized (2:1:1) to receive 1 dose of QIVc (n = 1335), TIV1c (n = 676), or TIV2c (n = 669). TIV1c (B/Yamagata) and TIV2c (B/Victoria) differed only in B strain lineage. The primary objective was to demonstrate non-inferiority of the hemagglutinin-inhibition antibody responses of QIVc against TIVc, 22 d post-vaccination. Secondary objectives included the evaluation of immunogenicity of QIVc and TIVc in younger (≥18 - <65 y) and older (≥65 y) adults. Hemagglutinin inhibition assays were performed at days 1 and 22. Solicited local and systemic adverse events (AEs) were monitored for 7 d post-vaccination, and unsolicited AEs and serious AEs until day 181. QIVc met the non-inferiority criteria for all 4 vaccine strains and demonstrated superiority for both influenza B strains over the unmatched B strain included in the TIV1c and TIV2c, when geometric mean titers and seroconversion rates with TIVc were compared at day 22. Between 48%-52% of subjects experienced ≥1 solicited AE, the most common being injection-site pain and headache. Serious AEs were reported by ≤1% of subjects, none were vaccine-related. The results indicate that QIVc is immunogenic and well tolerated in both younger and older adults. The immunogenicity and safety profiles of QIVc and TIVc were comparable at all ages evaluated.

Magnetic resonance venography to assess thrombus resolution with edoxaban monotherapy versus parenteral anticoagulation/warfarin for symptomatic deep vein thrombosis: A multicenter feasibility study

The feasibility of magnetic resonance venography (MRV) for measuring change in thrombus volume with a novel anticoagulation regimen versus standard anticoagulation in patients with symptomatic deep vein thrombosis (DVT) has not been assessed. Our aim was to study the feasibility of MRV to measure change in thrombus volume in patients with acute symptomatic objectively confirmed proximal DVT in an open-label multicenter trial (edoxaban Thrombus Reduction Imaging Study, eTRIS). We randomized patients in a 2:1 allocation ratio to edoxaban 90 mg/day for 10 days followed by 60 mg/day versus parenteral anticoagulation bridging to warfarin for 3 months. The primary efficacy outcome was a surrogate end point of the relative change in MRV-quantified thrombus volume from baseline to Day 14–21. A total of 85 eligible patients from 26 study sites were randomized to edoxaban monotherapy (n=56) versus parenteral anticoagulation as a ‘bridge’ to warfarin (n=29). The mean relative change in MRV-quantified thrombus volume from baseline to Day 14–21 was similar in patients treated with edoxaban and parenteral anticoagulation as a ‘bridge’ to warfarin (−50.1% vs −58.9%; 95% confidence interval of treatment difference, −12.7%, 30.2%). However, thrombus extension was observed in eight patients in the edoxaban monotherapy group and in none in the warfarin group. Rates of recurrent venous thromboembolism (3.6% vs 3.6%, p=0.45) and clinically relevant non-major bleeding (5.4% vs 7.1%, p=0.34) were also similar. No major bleeds occurred in either on-treatment group during the study period. In conclusion, MRV can assess change in thrombus volume in patients with acute DVT randomized to two different anticoagulant regimens.

ClinicalTrials.govIdentifier: NCT01662908

Investigational New Drug (IND) Application: Edoxaban IND # 63266

Synthesis and Spectroscopic Properties of 2,3-Diphenyl-1,3-thiaza-4-one Heterocycles

Synthetic and spectroscopic data (1H NMR, 13C NMR, IR, UV/Vis) for a series of six 2,3-diphenyl-1,3-thiaza-4-one heterocycles which differ in ring size and substitution is reported. The results show that there are significant differences in spectroscopic signals common to all six compounds. Distinctions can be made among the compounds using the IR absorbance of the C4 carbonyl and the 1H NMR signal at C2, and to a lesser extent the 13C NMR signal at C4 and the UV/Vis spectrum.{The equation can be found in the PDF file}.

Crystal Structures of 1,3-Thiaza-4-one Heterocycles

The five-, six-, and seven-membered 1,3-thiaza-4-one heterocycles are known for their bioactivity. Five-membered 1,3-thiazolidin-4-ones are known to have a very wide range of biological activity, so much that the ring system has been referred to as a "magic moiety" or "wonder nucleus" [1]. Six-membered 1,3-thiazin-4-ones have often been investigated for their biological activity and are of potential medicinal use [2]. The activity of seven-membered 1,3-thiazepan-4-ones is exemplified by the investigational compound omapatrilat [3]. Crystal structures of 1,3-thiaza-4-one heterocycles recently obtained in our laboratory will be presented.

Directional limits on persistent gravitational waves using LIGO S5 science data

The gravitational-wave (GW) sky may include nearby pointlike sources as well as stochastic backgrounds. We perform two directional searches for persistent GWs using data from the LIGO S5 science run: one optimized for pointlike sources and one for arbitrary extended sources. Finding no evidence to support the detection of GWs, we present 90% confidence level (C.L.) upper-limit maps of GW strain power with typical values between 2-20×10(-50)  strain(2) Hz(-1) and 5-35×10(-49)  strain(2) Hz(-1) sr(-1) for pointlike and extended sources, respectively. The latter result is the first of its kind. We also set 90% C.L. limits on the narrow-band root-mean-square GW strain from interesting targets including Sco X-1, SN 1987A and the Galactic center as low as ≈7×10(-25) in the most sensitive frequency range near 160 Hz.

Search for gravitational-wave bursts from soft gamma repeaters

We present a LIGO search for short-duration gravitational waves (GWs) associated with soft gamma ray repeater (SGR) bursts. This is the first search sensitive to neutron star f modes, usually considered the most efficient GW emitting modes. We find no evidence of GWs associated with any SGR burst in a sample consisting of the 27 Dec. 2004 giant flare from SGR 1806-20 and 190 lesser events from SGR 1806-20 and SGR 1900+14. The unprecedented sensitivity of the detectors allows us to set the most stringent limits on transient GW amplitudes published to date. We find upper limit estimates on the model-dependent isotropic GW emission energies (at a nominal distance of 10 kpc) between 3x10;{45} and 9x10;{52} erg depending on waveform type, detector antenna factors and noise characteristics at the time of the burst. These upper limits are within the theoretically predicted range of some SGR models.

Upper limits on a stochastic background of gravitational waves

The Laser Interferometer Gravitational-Wave Observatory has performed a third science run with much improved sensitivities of all three interferometers. We present an analysis of approximately 200 hours of data acquired during this run, used to search for a stochastic background of gravitational radiation. We place upper bounds on the energy density stored as gravitational radiation for three different spectral power laws. For the flat spectrum, our limit of omega0 < 8.4 x 10(-4) in the 69-156 Hz band is approximately 10(5) times lower than the previous result in this frequency range.

Temporal and Spatial Changes of the Agroclimate in Alberta, Canada, from 1901 to 2002

This paper analyzes the long-term (1901–2002) temporal trends in the agroclimate of Alberta, Canada, and explores the spatial variations of the agroclimatic resources and the potential crop-growing area in Alberta. Nine agroclimatic parameters are investigated: May–August precipitation (PCPN), the start of growing season (SGS), the end of the growing season (EGS), the length of the growing season (LGS), the date of the last spring frost (LSF), the date of the first fall frost (FFF), the length of the frost-free period (FFP), growing degree-days (GDDs), and corn heat units (CHUs). The temporal trends in the agroclimatic parameters are analyzed by using linear regression. The significance tests of the trends are made by using Kendall’s tau method. The results support the following conclusions. 1) The Alberta PCPN has increased 14% from 1901 to 2002, and the increment is the largest in the north and the northwest of Alberta, then diminishes (or even becomes negative over two small areas) in central and southern Alberta, and finally becomes large again in the southeast corner of the province. 2) No significant long-term trends are found for the SGS, EGS, and LGS. 3) An earlier LSF, a later FFF, and a longer FFP are obvious all over the province. 4) The area with sufficient CHU for corn production, calculated according to the 1973–2002 normal, has extended to the north by about 200–300 km, when compared with the 1913–32 normal, and by about 50–100 km, when compared with the 1943–72 normal; this expansion implies that the potential exists to grow crops and raise livestock in more regions of Alberta than was possible in the past. The annual total precipitation follows a similar increasing trend to that of the May–August precipitation, and the percentile analysis of precipitation attributes the increase to low-intensity events. The changes of the agroclimatic parameters imply that Alberta agriculture has benefited from the last century’s climate change.

Validation of the NFL-225 test for predicting 1-RM bench press performance in college football players

BACKGROUND

The purpose of this study was to evaluate the accuracy of repetitions-to-fatigue (RTF) using an absolute load of 102.3 kg (225 lbs) to estimate one-repetition maximum (1-RM) bench press performance in college football players using various prediction equations.

METHODS

EXPERIMENTAL DESIGN

a prospective study on the association between muscular endurance and muscular strength.

PARTICIPANTS

260 players from NCAA Division IA (n=43), IAA (n=63), II (n=129), and red-shirts (n=25) were evaluated at the conclusion of a minimum of eight weeks of heavy-resistance training during the off-season.

MEASURES

all subjects performed a 1-RM bench press and RTF using an absolute load of 102.3 kg.

RESULTS

The Mayhew et al. NFL-225 equation nonsignificantly overestimated 1-RM from RTF by 0.5 kg, while the Chapman et al. NFL-225 equation significantly underpredicted by 3.2 kg, although both equations were comparable in the number of players predicted within +/-4.5 kg of actual 1-RM (52% vs 51%, respectively). Only two of nine RTF equations currently in use produced predicted 1-RM values that were not significantly different from actual 1-RM performance.

CONCLUSIONS

Specific NFL-225 equations are more accurate in estimating 1-RM bench press from absolute muscle endurance in college football players than previous published RTF equations. The accuracy of prediction decreases at higher repetitions.

Therapeutic effect of a Gag-nuclease fusion protein against retroviral infection in vivo

Recently, remarkable progress has been made in developing effective combination drug therapies that can control but not cure retroviral replication. Even when effective, these drug regimens are toxic, they require demanding administration schedules, and resistant viruses can emerge. Thus the need for new gene-based therapies continues. In one such approach, capsid-targeted viral inactivation (CTVI), nucleases fused to viral coat proteins are expressed in infected cells and become incorporated during virion assembly. CTVI can eliminate infectious murine retrovirus titer in tissue culture. Here we describe transgenic mice expressing fusions of the Moloney murine leukemia virus (Mo-MuLV) Gag protein to staphylococcal nuclease. This work tests the protective effect and demonstrates in vivo proof-of-principle of CTVI in transgenic mice expressing endogenous proviral copies of Mo-MuLV. The antiviral protein-expressing mice are phenotypically normal, attesting to the lack of toxicity of the fusion protein. The Mo-MuLV infection was much less virulent in transgenic littermates than in nontransgenic littermates. Gag-nuclease expression reduced infectious titers in blood up to 10-fold, decreased splenomegaly and leukemic infiltration, and increased life spans up to 2.5-fold in transgenic relative to nontransgenic infected animals. These results suggest that gene therapies based on similar fusion proteins, designed to attack human immunodeficiency virus or other retroviruses, could provide substantial therapeutic benefits.

Synthesis of novel 2-azabicyclo[2.2.0]- and [2.1.1]hexanols

Methyl- and phenyl-substituted N-(ethoxycarbonyl)-2-azabicyclo[2.2.0]hex-5-enes 6 were reacted with NBS in wet DMSO to afford bromohydrins. Mixtures of unrearranged 6-exo-bromo-5-endo-hydroxy-2-azabicyclo[2.2.0]hexanes 7a,b and rearranged 5-anti-bromo-6-anti-hydroxy-2-azabicyclo[2.1.1]hexanes 8a,b were formed stereoselectively from the parent alkene 6a and 4-methyl alkene 6b. The 5-methyl alkene 6c affords only unrearranged bromohydrin 7c and dibromohydrin 9. By contrast, solely rearranged 3-endo-substituted-2-azabicyclo[2.1.1]hexane bromohydrins 8d-f result from additions to 3-endo-methyl alkene 6d, 3-endo-4-dimethyl alkene 6e, and 3-endo-phenyl alkene 6f. As an alternative route to bromohydrins, the parent 5,6-exo-epoxide 10a and 5-endo-methyl-5,6-exo-epoxide 10b were ring opened with bromine/triphenylphosphine to afford unrearranged 5-endo-bromo-6-exo-hydroxy-2-azabicyclo[2.2.0]hexanes 11a,b, while the 3-endo-methyl epoxide 10c afforded solely the rearranged 5-anti-bromo-6-anti-hydroxy-3-exo-methyl-2-azabicyclo[2.1.1]hexane isomer 8g. Tributyltin hydride reduction of bromohydrins 7a,b and 11a afforded novel 2-azabicyclo[2.2.0]hexan-5-ols 13a,b and -6-ol 14, and bromohydrins 8a,b, 8d-g afforded new 2-azabicyclo[2.1.1]-hexan-5-ols 15a,b and 15d-g.

Moloney murine leukemia virus protease expressed in bacteria is enzymatically active

Replication of Moloney murine leukemia virus requires a readthrough translation mechanism to generate the Gag-Pol polyprotein. One of the final products of this polyprotein is the protease (PR), which is required to generate the mature virion proteins. The assembly of Gag and Gag-Pol polyprotein into a virion followed by activation of the viral protease is necessary to produce a mature, infectious particle. These events are believed to occur near the cell membrane just prior to the budding of the virion. We report here the autoproteolytic activity of the viral PR when a Gag-PR fusion protein is expressed in E. coli. Efficient cleavage at the p12/CA, CA/NC and NC/PR junctions was observed. Thus the Moloney murine leukemia virus PR is capable of cleaving its substrates in the absence of specific host factors.

Antiretroviral effect of a gag-RNase HI fusion gene

We have previously shown that a molecule consisting of a fusion of a Ca(2+)-dependent nuclease (from Staphylococcus aureus) to a retroviral coat protein specifies a potent antiviral specific for that retrovirus. Genes specifying such fusion proteins can be delivered to virus-susceptible cells, providing an antiviral gene therapy aimed at limiting virus spread. We report here the results of experiments to vary the nuclease moiety of such fusion proteins. We found that one nuclease. Serratia marcescens nuclease, was extremely toxic to host cells and hence not likely to be useful for therapeutic purposes. A second nuclease, Escherichia coli RNase Hl was found to be nontoxic and highly effective against a murine leukemia virus when it was fused to the leukemia virus coat protein. The fusion protein was enzymatically active and stably expressed, without apparent toxicity to host cells. Reduction in infectious virus output was as high as 97-99%. These studies provide a model system for the development of gene therapeutic agents aimed at combating retroviral infections in vivo.

NF-kappa B-mediated chromatin reconfiguration and transcriptional activation of the HIV-1 enhancer in vitro

NF-kappa B is a potent inducible transcription factor that regulates many genes in activated T cells. In this report we examined the ability of different subunits of NF-kappa B to enhance HIV-1 transcription in vitro with chromatin templates. We find that the p65 subunit of NF-kappa B is a strong transcriptional activator of nucleosome-assembled HIV-1 DNA, whereas p50 does not activate transcription, and that p65 activates transcription synergistically with Sp1 and distal HIV-1 enhancer-binding factors (LEF-1, Ets-1, and TFE-3). These effects were observed with chromatin, but not with nonchromatin templates. Furthermore, binding of either p50 or p65 with Sp1 induces rearrangement of the chromatin to a structure that resembles the one reported previously for integrated HIV-1 proviral DNA in vivo. These results suggest that p50 and Sp1 contribute to the establishment of the nucleosomal arrangement of the uninduced provirus in resting T cells, and that p65 activates transcription by recruitment of the RNA polymerase II transcriptional machinery to the chromatin-repressed basal promoter.

Activation of the HIV-1 enhancer by the LEF-1 HMG protein on nucleosome-assembled DNA in vitro

Lymphoid enhancer-binding factor 1 (LEF-1) is a regulatory high mobility group (HMG) protein that activates the T cell receptor alpha (TCR alpha) enhancer in a context-restricted manner in T cells. In this paper we demonstrate that the distal region of the human immunodeficiency virus-1 (HIV-1) enhancer, which contains DNA-binding sites for LEF-1 and Ets-1, also provides a functional context for activation by LEF-1. First, we show that mutations in the LEF-1-binding site inhibit the activity of multimerized copies of the HIV-1 enhancer in Jurkat T cells, and that LEF-1/GAL4 can activate a GAL4-substituted HIV-1 enhancer 80- to 100-fold in vivo. Second, recombinant LEF-1 is shown to activate HIV-1 transcription on chromatin-assembled DNA in vitro. By using a nucleosome-assembly system derived from Drosophila embryos, we find that the packaging of DNA into chromatin in vitro strongly represses HIV-1 transcription and that repression can be counteracted efficiently by preincubation of the DNA with LEF-1 (or LEF-1 and Ets-1) supplemented with fractions containing the promoter-binding protein, Sp1. Addition of TFE-3, which binds to an E-box motif upstream of the LEF-1 and Ets-1 sites, further augments transcription in this system. Individually or collectively, none of the three enhancer-binding proteins (LEF-1, Ets-1, and TFE-3) could activate transcription in the absence of Sp1. A truncation mutant of LEF-1 (HMG-88), which contains the HMG box but lacks the trans-activation domain, did not activate transcription from nucleosomal DNA, indicating that bending of DNA by the HMG domain is not sufficient to activate transcription in vitro. We conclude that transcription activation by LEF-1 in vitro is a chromatin-dependent process that requires a functional trans-activation domain in addition to the HMG domain.

Product of a new gene, syd, functionally interacts with SecY when overproduced in Escherichia coli

A mutant form of SecY, SecY-d1, was previously suggested to sequester a component(s) of the protein translocator complex. Its synthesis from a plasmid leads to interference with protein export in Escherichia coli. SecE is a target of this sequestration, and its overproduction cancels the export interference. We now report that overexpression of another gene, termed syd, also suppresses secY-d1. The nucleotide sequence of syd predicted that it encodes a protein of 181 amino acid residues, which has been identified by overproduction, purification, and determination of the amino-terminal sequence. Cell fractionation experiments suggested that Syd is loosely associated with the cytoplasmic surface of the cytoplasmic membrane. SecY may be involved in the membrane association of Syd since the association is saturable, the extent of which depends on the overproduction of SecY. SecY is rapidly degraded in vivo unless its primary partner, SecE, is sufficiently available. Overproduction of Syd was found to stabilize oversynthesized SecY. However, Syd cannot stabilize the SecY-d1 form of SecY. Thus, in the presence of both secY+ and secY-d1, Syd increases the effective SecY+/SecY-d1 ratio in the cell and cancels the dominant interference by the latter. We also found that overproduction of Syd dramatically inhibits protein export in the secY24 mutant cell in which SecY-SecE interaction has been weakened. These results indicate that Syd, especially when it is overproduced, has abilities to interact with SecY. Possible significance of such interactions is discussed in conjunction with the apparent lack of phenotypic consequences of genetic disruption of syd.

Two members of a distinct subfamily of 5-hydroxytryptamine receptors differentially expressed in rat brain

We report two serotonin (5-hydroxytryptamine, 5-HT) receptors, MR22 and REC17, that belong to the G-protein-associated receptor superfamily. MR22 and REC17 are 371 and 357 amino acids long, respectively, as deduced from nucleotide sequence and share 68% mutual amino acid identity and 30-35% identity with known catecholamine and 5-HT receptors. Saturable binding of 125I-labeled (+)-lysergic acid diethylamide to transiently expressed MR22 in COS-M6 cells was inhibited by ergotamine > methiothepin > 5-carboxamidotryptamine > 5-HT. For REC17, the rank of potency was ergotamine > 5-carboxamidotryptamine > methiothepin > methysergide > 5-HT. Both were insensitive to 5-HT1A, 5-HT1D or 5-HT2 serotonergic ligands [8-hydroxy-2-(di-n-propylamino)tetralin, sumatriptan, and 1-(2,5-dimethoxy-4-iodophenyl)-2-aminopropane]. The mRNAs encoding MR22 were detected in the CA1 region of hippocampus, the medial habenula, and raphe nuclei. In contrast, mRNAs encoding REC17 were found throughout the rat central nervous system. We propose that REC17 and MR22, designated as 5-HT5 alpha and 5-HT5 beta, represent a distinct subfamily of 5-HT receptors.

Evaluation of coagulation studies from heparinized arterial lines with use of Lab-Site high-pressure tubing

Heparinized arterial catheters are commonly used in critically ill patients to monitor pressures and to collect blood for laboratory analysis. To remove the heparinized fluid used to keep these lines patent large volumes of blood are often withdrawn and discarded or calculations of tube volume must be made. Repeated violation of stopcocks may lead to contamination and infection of arterial lines. In addition, discarded blood has become an increasing concern as a source of infection for health care personnel. This study evaluates the efficacy of noncompliant arterial line tubing that contains two polymer sampling ports permanently placed at prefixed distances such that if blood is withdrawn to the distal port, undiluted arterial blood can then be withdrawn from the proximal port. Blood from arterial lines that consisted of 20-gauge catheters connected to Lab-Site tubing was withdrawn in the method suggested by the manufacturer with no removal or wasting of excess blood from the system. Prothrombin time (PT) and activated partial thromboplastin time (aPTT) studies performed on this sample were compared with those performed on a simultaneously drawn venous sample. Regression analysis showed a correlation coefficient of 0.966 for PT and 0.935 for aPTT, demonstrating an excellent correlation for the technique. The average arterial PT was 0.12 seconds less than venous control and the average arterial aPTT was 0.49 seconds greater than control. Neither of these differences was significant. We conclude that this type of high-pressure tubing allows accurate blood samples to be obtained from arterial lines without the necessity of precise calculations or blood wastage.

Prospective randomized evaluation of two methods of drawing coagulation studies from heparinized arterial lines

To establish a standardized protocol of obtaining coagulation studies from arterial lines without heparin contamination, two methods were evaluated in a prospective randomized fashion for accuracy by comparing PT and aPTT results with simultaneous samples drawn by venipuncture. Fifty paired samples were obtained, 25 by method A and 25 by method B, from critically ill patients in the surgical intensive care unit at City of Memphis Hospital. Analyses of PT and aPTT from these samples revealed a close statistical correlation with the venous controls and no clinically significant difference between the samples.