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Objective: In‐depth suicide risk assessments are particularly important to long‐term suicide prevention. Broadband measures of psychopathology, such as the Minnesota Multiphasic Personality Inventory (MMPI) instruments, assess suicide risk factors and various mental health comorbidities. With the recent release of the MMPI‐3, the Suicidal/Death Ideation (SUI) scale underwent revisions to improve its construct validity and detection of suicide risk factors. Thus, we hypothesized the MMPI‐3 SUI scale would demonstrate medium to large associations with suicidal experience and behaviors, future ideation, and interpersonal risk factors of suicide. Methods: A sample of 124 college students screened for elevated depressive symptoms completed a brief longitudinal study. Participants completed a baseline session including the MMPI‐3 and criterion measures and three brief follow‐ups every 2 weeks. Results: SUI scores were most robustly associated with increased risk for past suicidal ideation, planning, and perceived burdensomeness. Prospectively assessed suicidal ideation was also meaningfully associated with SUI. SUI scale elevations indicate an increased risk of suicide‐related risk factors. Conclusion: The MMPI‐3 is a valuable tool to inform long‐term suicide prevention for those experiencing elevated depressive symptoms as the SUI scale can assess past, current, and future suicide‐related risk factors, including suicidal ideation and behaviors. [ABSTRACT FROM AUTHOR]

Golf course superintendents may use bensulide to control annual grassy weeds and carfentrazone‐ethyl (CE) to control silvery‐thread moss (Bryum argenteum Hedw.) in creeping bentgrass putting greens. Creeping bentgrass injury has been reported if CE is applied soon after treatment with bensulide and the safe application interval varies as much as 68 days. Our goal was to improve the precision of recommendations for safe application of CE following bensulide, considering both CE rate and timing. We used a factorial treatment structure that included (1) bensulide or no bensulide, (2) three rates of CE, and (3) nine CE application timings in 2018 and 2019 at locations in Nebraska and Ohio. Because of limited effects in 2018, different CE rates and application timings were used in 2019. Significant creeping bentgrass injury was only observed at 6.7 or 13.4 fl oz acre−1 rates of CE that were applied within 3 days of applying bensulide. Even the 13.4 fl oz acre−1 rate (a 2× rate) of CE did not injure creeping bentgrass when applied at least 7 days after applying bensulide. The 2.0 fl oz acre−1 rate of CE never injured creeping bentgrass, even when applied the same day as bensulide. Cultivar, management, and environmental differences may influence whether subsequent application of bensulide and CE injures creeping bentgrass. Based on the environmental/cultural conditions and cultivars used in this research, golf course superintendents should expect little to no injury when CE is applied at least 1 week after applying bensulide. Plain Language Summary: The herbicides bensulide and carfentrazone‐ethyl are often used to control weeds in golf course putting greens, but researchers have reported injury to creeping bentgrass if carfentrazone‐ethyl is applied too soon after and application of bensulide. The objective of our research was to determine the safe application interval for various rates of carfentrazone‐ethyl following and application of bensulide. Based on this research, golf course superintendents should expect little to no injury when CE is applied according to label specifications and withheld for at least 7 days after applying bensulide. [ABSTRACT FROM AUTHOR]

Objective: To evaluate the accuracy of two portable ultrasound machines (PUM) in assessing fetal biometry and estimated gestational age (EGA). Methods: This was a secondary analysis of data from the Fetal Age Machine Learning Initiative, an observational study of pregnant women in the USA and Zambia. Each participant underwent ultrasound assessment by an experienced sonographer using both a high‐specification ultrasound machine (HSUM) and a PUM (Butterfly iQ or Clarius C3) to measure fetal biometry and calculate EGA at each visit. By comparing paired PUM and HSUM scans, we estimated agreement between individual biometry measurements and aggregate gestational age estimates by reporting mean difference, intraclass correlation coefficient (ICC) and Bland–Altman plots, adjusting for trend. Results: Between April and December 2021, 818 participants contributed 1386 paired PUM–HSUM ultrasound investigations, of which 991 PUM scans were obtained using the Butterfly iQ device and 395 using the Clarius C3 device. Gestational age at scan ranged from 7 to 38 weeks. Compared with HSUM, the Butterfly iQ PUM had a mean difference of −0.20 (95% CI, −0.60 to 0.20) days in the first trimester and −0.68 (95% CI, −0.93 to −0.44) days in the second/third trimesters. Compared with HSUM, the Clarius C3 PUM had a mean difference of −0.47 (95% CI, −1.11 to 0.18) days in the first trimester and −1.67 (95% CI, −2.10 to −1.25) days in the second/third trimesters. ICCs were 0.989 or greater throughout. Increasing gestational age was associated with increasing error and absolute error in EGA and fetal biometry. Both PUM devices demonstrated a modest trend toward underestimation of EGA with advancing gestational age in second/third‐trimester scans, compared with HSUM. Conclusion: The Butterfly iQ and Clarius C3 PUM devices were highly accurate in performing fetal biometry in a diverse population from the USA and Zambia. © 2023 International Society of Ultrasound in Obstetrics and Gynecology. [ABSTRACT FROM AUTHOR]

Interaction between mesoscale eddies and near‐inertial internal waves can contribute to enhanced turbulence mixing but quantitative knowledge from in situ observations is still lacking. This study reveals how eddy/near‐inertial wave interactions (ENIs) can affect the variability of turbulent mixing in the ice‐covered Canada Basin of the Arctic Ocean. We use data from five Ice‐Tethered Profiler with Velocity (ITP‐V) systems that autonomously obtained vertical profiles of horizontal velocity as well as temperature and salinity, which enabled quantification of ENI‐caused turbulent mixing using a fine‐scale parameterization. From the ITP‐V observations in 2013–2015, 67 anticyclones were detected, of which 90% had a deep core at 150–250 m depth. The remaining eddies had a shallow core, typically embedded in the Pacific Summer Water (PSW). Just over one third of the eddies showed evidence of ENI with enhanced near‐inertial internal wave amplitude (NIW) near the eddy cores. For these ENI cases, the parameterized turbulence dissipation rate was O (10−10–10−8 W kg−1), the larger estimates being several orders of magnitude greater than the background level. For the deep eddies, the ENI process can largely be accounted for by the classical theory, NIWs are trapped inside the negative relative vorticity core of anticyclones. For one shallow eddy, the NIW signal was greatest below the core. We postulate that a vertically elongated system of NIWs cannot be constrained vertically within such small‐cored eddies. It is also interpreted that the wave enhancement below the core was supported by the isopycnal slope near the PSW through its geostrophic shear. Plain Language Summary: Two ocean phenomena, eddies and internal waves, are known to interact and contribute to hotspots of strong mixing in the upper ocean. We analyze extensive observations of the interaction of eddies and internal waves in the ice‐covered Arctic Canada Basin using data from several autonomous instruments: the Ice‐Tethered Profiler with Velocity (ITP‐V). The ITP‐V repeatedly measures vertical profiles of ocean temperature, salinity, and currents at 1 m vertical resolution. During 2013–2015, ITP‐Vs encountered 67 individual eddies with core depths ranging between 40 and 250 m. Of these, 90% were found at depths of 150–250 m, while the rest were shallow features. Approximately one third of the observed eddies exhibited internal waves with enhanced amplitudes near the eddy core depths that are inferred to support intensified mixing. For the deep eddies, the amplified waves were mostly observed within the eddies, consistent with previous studies. For one shallow eddy, enhanced wave signals were found below something that has not been previously reported. For this case, we deduced that the sloping stratification associated with the eddy azimuthal flow modified the propagation of waves and resulting in the enhanced mixing on the underside of the eddy. Key Points: High‐resolution autonomous observations of hydrography and currents were conducted in pack ice regions of the Canada Basin, Arctic OceanInteraction between anticyclonic mesoscale eddies and near‐inertial internal waves enhanced turbulent mixing roughly by factor of twoA shallow eddy showed significant wave enhancement below its core resulting from combination of negative vorticity and slanted isopycnals [ABSTRACT FROM AUTHOR]

Objectives: Carbapenems are a critically important class of antimicrobials used to treat infections caused by multi‐drug‐resistant bacteria. Following an outbreak of a carbapenemase (NDM‐5)‐producing strain of Escherichia coli at our veterinary institution, we opted to describe the use of carbapenems in our institution and the role that drug contraindications in patients may have played when culture and susceptibility testing identified alternative drug options. Materials and Methods: Medical record reviews of all cases where a carbapenem was prescribed were performed, and indications for use, timing of prescribing relative to culture and susceptibility reports, and alternative possible antimicrobial treatments were extracted. Contraindications to alternative antimicrobials were also documented. Results: Carbapenems were prescribed infrequently: from 2013 to 2018, they accounted for 0.47% of all antimicrobial prescriptions and were administered to 108 of 56,776 (0.2%) patients seen at our institution. They were prescribed empirically in slightly more than half of the patients (57.6%). Among cases where a carbapenem was prescribed after culture and susceptibility results were available, alternative antimicrobials could have been used in 68.3% of cases. Clinical Significance: Variability in use of these drugs within an institution highlights the need to develop well‐defined use guidelines, including when to use these drugs empirically and how to safely de‐escalate or choose alternative drugs guided by culture and susceptibility results. [ABSTRACT FROM AUTHOR]

Most cell penetrating peptides (CPPs) are unstructured and susceptible to proteolytic degradation. One alternative is to incorporate D‐chirality amino acids into unstructured CPPs to allow for enhanced uptake and intracellular stability. This work investigates CPP internalization using a series of time, concentration, temperature, and energy dependent studies, resulting in a three‐fold increase in uptake and 50‐fold increase in stability of D‐chirality peptides over L‐chirality counterparts. CPP internalization occurred via a combination of direct penetration and endocytosis, with a percentage of internalized CPP expelling from cells in a time‐dependent manner. Mechanistic studies identified that cells exported the intact internalized D‐chirality CPPs via an exocytosis independent pathway, analogous to a direct penetration method out of the cells. These findings highlight the potential of a D‐chirality CPP as bio‐vector in therapeutic and biosensing applications, but also identify a new expulsion method suggesting a relationship between uptake kinetics, intracellular stability, and export kinetics. [ABSTRACT FROM AUTHOR]

Core Ideas: It is common to scalp glyphosate‐treated areas to sow desirable species following treatment.Product labels recommend withholding mowing for several days before or after an application.Information is needed to precisely define scalping restriction recommendations surrounding glyphosate applications.Scalping tall fescue from one hour before to one hour after glyphosate treatment reduces efficacy.Glyphosate efficacy is not reduced when scalping occurs as soon as one day following treatment. Glyphosate (N‐(phosphonomethyl)glycine) is commonly used during renovations and to control difficult weeds. Users commonly scalp treated areas to sow desirable species following treatment, and most product labels recommend withholding mowing for several days before or after treatment. Our objective was to determine the effect of scalping timing on tall fescue [Schedonorus arundinaceus (Schreb.) Dumort.] control with glyphosate in fall or spring. Three‐inch tall fescue was treated with glyphosate at 2.24 lbs a.e./acre and scalped one day or one hour before treatment, or one hour or one to five days after treatment at two locations (Nebraska and Kansas) in fall and spring. Green cover of tall fescue was rated until 32 or 8 weeks after treatment (WAT) for fall and spring experiments, respectively. In fall, glyphosate efficacy was not reduced when turf was scalped one to five days after treatment (0 to 3% green tall fescue cover by 32 WAT). With the exception of scalping two days after spring treatment with glyphosate in Nebraska, the same was also true in spring at both locations (0 to 8% green tall fescue cover by 8 WAT). Scalping within one hour of glyphosate treatment consistently and significantly reduced efficacy, and scalping one day before treatment only yielded control similar to the best treatments in Kansas in spring. Tall fescue control with glyphosate is not reduced by scalping as soon as one day following treatment in either fall or spring, which is two days sooner than typically recommended. [ABSTRACT FROM AUTHOR]

For ice concentrations less than 85%, internal ice stresses in the sea ice pack are small and sea ice is said to be in free drift. The sea ice drift is then the result of a balance between Coriolis acceleration and stresses from the ocean and atmosphere. We investigate sea ice drift using data from individual drifting buoys as well as Arctic‐wide gridded fields of wind, sea ice, and ocean velocity. We perform probabilistic inverse modeling of the momentum balance of free‐drifting sea ice, implemented to retrieve the Nansen number, scaled Rossby number, and stress turning angles. Since this problem involves a nonlinear, underconstrained system, we used a Monte Carlo guided search scheme—the Neighborhood Algorithm—to seek optimal parameter values for multiple observation points. We retrieve optimal drag coefficients of CA=1.2×10−3 and CO=2.4×10−3 from 10‐day averaged Arctic‐wide data from July 2014 that agree with the AIDJEX standard, with clear temporal and spatial variations. Inverting daily averaged buoy data give parameters that, while more accurately resolved, suggest that the forward model oversimplifies the physical system at these spatial and temporal scales. Our results show the importance of the correct representation of geostrophic currents. Both atmospheric and oceanic drag coefficients are found to decrease with shorter temporal averaging period, informing the selection of drag coefficient for short timescale climate models. Key Points: The momentum balance of free‐drifting sea ice has been invertedWe use buoy and satellite/reanalysis coincident wind, sea ice and ocean dataDrag coefficients for various data formats are retrieved [ABSTRACT FROM AUTHOR]

Core Ideas: The fall is the optimum time to control winter annual and perennial broadleaf weeds.More information is needed on postemergence herbicide safety in the fall as buffalograss enters winter dormancy.Many postemergence herbicides can be safely applied to buffalograss entering winter dormancy with no effect on spring greenup.Turf managers have many herbicide and application timing options for weed control in buffalograss. [ABSTRACT FROM AUTHOR]

Existing surface water flood forecasting methods in Scotland are based on indicative depth-duration rainfall thresholds with limited understanding of the likelihood of inundation or associated impacts. Innovative risk-based solutions are urgently needed to advance surface water forecasting capabilities for improved flood resilience in urban centres. A new model-based solution was developed for Glasgow, linking 24-h ensemble rainfall predictions from the Met Office Global and Regional Ensemble Prediction System for the UK (MOGREPS-UK) with static flood risk maps through the Grid-to-Grid hydrological model. This new forecasting capability was used operationally by the Scottish Flood Forecasting Service during the 2014 Commonwealth Games to provide bespoke surface water flooding guidance to responders. The operational trial demonstrated the benefits of being able to provide targeted information on real-time surface water flood risk. It also identified the high staff resource requirement to support the service due to the greater uncertainty in surface water flood forecasting compared to established fluvial and coastal methods. [ABSTRACT FROM AUTHOR]

Inadequate dose selection for confirmatory trials is currently still one of the most challenging issues in drug development, as illustrated by high rates of late-stage attritions in clinical development and postmarketing commitments required by regulatory institutions. In an effort to shift the current paradigm in dose and regimen selection and highlight the availability and usefulness of well-established and regulatory-acceptable methods, the European Medicines Agency (EMA) in collaboration with the European Federation of Pharmaceutical Industries Association (EFPIA) hosted a multistakeholder workshop on dose finding (London 4-5 December 2014). Some methodologies that could constitute a toolkit for drug developers and regulators were presented. These methods are described in the present report: they include five advanced methods for data analysis (empirical regression models, pharmacometrics models, quantitative systems pharmacology models, MCP-Mod, and model averaging) and three methods for study design optimization (Fisher information matrix (FIM)-based methods, clinical trial simulations, and adaptive studies). Pairwise comparisons were also discussed during the workshop; however, mostly for historical reasons. This paper discusses the added value and limitations of these methods as well as challenges for their implementation. Some applications in different therapeutic areas are also summarized, in line with the discussions at the workshop. There was agreement at the workshop on the fact that selection of dose for phase III is an estimation problem and should not be addressed via hypothesis testing. Dose selection for phase III trials should be informed by well-designed dose-finding studies; however, the specific choice of method(s) will depend on several aspects and it is not possible to recommend a generalized decision tree. There are many valuable methods available, the methods are not mutually exclusive, and they should be used in conjunction to ensure a scientifically rigorous understanding of the dosing rationale. [ABSTRACT FROM AUTHOR]

Physiologically based pharmacokinetic (PBPK) modeling is a valuable tool in drug development and regulatory assessment, as it offers the opportunity to simulate the pharmacokinetics of a compound, with a mechanistic understanding, in a variety of populations and situations. This work reviews the use and impact of such modeling in selected regulatory procedures submitted to the European Medicines Agency (EMA) before the end of 2015, together with its subsequent reflection in public documents relating to the assessment of these procedures. It is apparent that the reference to PBPK modeling in regulatory public documents underrepresents its use. A positive trend over time of the number of PBPK models submitted is shown, and in a number of cases the results of these may impact the decision-making process or lead to recommendations in the product labeling. These results confirm the need for regulatory guidance in this field, which is currently under development by the EMA. [ABSTRACT FROM AUTHOR]

Background Distinct gene expression profiles in peripheral blood mononuclear cells ( PBMCs) consistent with increased sympathetic nervous system activity have been described in different populations under chronic stress. Neuroinflammatory brain changes, possibly related to the migration of primed monocytes to the brain, have been implicated in the pathophysiology of chronic pain. Irritable bowel syndrome ( IBS) is a stress-sensitive gastrointestinal disorder associated with altered brain-gut interactions and increased sympathetic/vagal tone and anxiety. Reports about immune alterations in IBS are conflicting. This pilot study aimed to test how PBMC gene expression inflammatory profiles are correlated with altered brain signatures in the salience system. Methods Sixteen IBS and 16 healthy controls ( HCs) completed resting state MRI scans. Gene expression profiles in PBMCs were assessed using human transcriptome array-2. Bioinformatic analyses determined differential expression of PBMCs between IBS and HCs. Partial least squares, a multivariate analysis technique, was used to identify disease correlations between PBMC gene expression profiles and functional activity in the brain's salience network. Key Results Regions of the salience network, including the mid cingulate cortex, and mid and superior temporal gyrus were positively correlated with several pro-inflammatory genes (interleukin 6, APOL2) in IBS, but negatively correlated with several anti-inflammatory genes ( KRT8, APOA4) in HCs. Conclusions & Inferences Based on rodent studies, one may speculate that chronically activated stress signaling pathways in IBS maintain a pro-inflammatory state in the periphery. Alternatively, primed monocytes may migrate to the brain during stress, inducing regional neuroinflammatory changes in salience regions involved in the modulation of visceral sensitivity. [ABSTRACT FROM AUTHOR]

Core Ideas: More information is needed to improve late‐season bermudagrass control strategies in the Central Plains region of the United States.A single autumn application of glyphosate reduces bermudagrass cover the following spring.Bermudagrass control with a single autumn application of glyphosate was not improved by adding fluazifop, mesotrione, or both. Multiple summer applications of glyphosate (N‐(phosphonomethyl)glycine) are commonly recommended for bermudagrass (Cynodon spp.) control. However, this regime results in an extended period of displeasing and nonfunctional turfgrass, and is not ideal for spring establishment. An autumn glyphosate application prior to winter dormancy can control bermudagrass and may benefit spring establishment projects. However, research is needed to more precisely define the parameters of efficacious late‐season herbicide applications for bermudagrass control as it transitions into dormancy. Therefore, our objective was to examine late‐season bermudagrass removal using combinations of glyphosate, fluazifop‐p‐butyl (fluazifop) (Butyl (R)‐2‐[4[[5‐(trifluoromethyl)‐2‐pyridinyl]oxy]phenoxy]propanoate), and mesotrione (2‐(4‐methylsulfonyl‐2‐nitrobenzoyl)‐1,3‐cyclohexanedione). Experiments were initiated in October 2013 at the Rocky Ford Turfgrass Research Center in Manhattan, KS, on mature 'Midlawn' hybrid bermudagrass [Cynodon dactylon (L.) Pers. × C. transvaalensis Burtt‐Davy], and at Stagg Hill Golf Course in Manhattan, KS, on mature common bermudagrass [C. dactylon (L.) Pers.]. Seven herbicide treatments containing combinations of glyphosate, fluazifop, and mesotrione were evaluated. Green bermudagrass cover (0–100%) was visually estimated when treatments were applied and every 14 d after application. Only treatments containing glyphosate reduced the green cover of bermudagrass at each site the following year. Across all ratings dates and locations, adding mesotrione, fluazifop, or both to glyphosate did not further reduce green bermudagrass cover. Overall, results indicate that a single autumn application of glyphosate prior to bermudagrass dormancy reduces bermudagrass cover the following spring. The significant reduction at spring green‐up may allow turf managers to make additional applications in the spring for increased control before spring establishment. [ABSTRACT FROM AUTHOR]

Mycobacterial cell walls are complex structures containing a broad range of unusual lipids, glycolipids and other polymers, some of which act as immunomodulators or virulence determinants. Better understanding of the enzymes involved in export processes would enlighten cell wall biogenesis. Bernut et al. () present the findings of a structural and functional investigation of one of the most important transporter families, the MmpL proteins, members of the resistance-nodulation-cell division (RND) superfamily. A Tyr842His missense mutation in the mmpL4a gene was shown to be responsible for the smooth-to-rough morphotype change of the near untreatable opportunistic pathogen Mycobacterium bolletii due to its failure to export a glycopeptidolipid (GPL). This mutation was pleiotropic and markedly increased virulence in infection models. Tyr842 is well conserved in all actinobacterial MmpL proteins suggesting that it is functionally important and this was confirmed by several approaches including replacing the corresponding residue in MmpL3 of Mycobacterium tuberculosis. Structural modelling combined with experimental results showed Tyr842 to be a critical residue for mediating the proton motive force required for GPL export. This mechanistic insight applies to all MmpL proteins and probably to all RND transporters. [ABSTRACT FROM AUTHOR]

Background Reduced intensity conditioning ( RIC) protocols for allogeneic haemopoietic cell transplants ( HCT) have become commonplace treatments for patients with haematological disease, extending allogeneic HCT to older and less fit patients. There is a perception that centres treating larger numbers of patients have improved outcomes. Aims We wanted to examine whether outcomes for adult allogeneic HCT patients from our smaller centre were equivalent to those expected at larger centres internationally. Methods Clinical and laboratory data were collected on all patients who received allogeneic HCT during 2000-2012. Outcomes, including overall survival ( OS) and progression-free survival, were compared between patients receiving myeloablative conditioning ( MAC) and RIC protocols. Results One hundred and eighteen adult patients underwent allogeneic HCT with MAC ( n = 51) or RIC ( n = 67). The mean age of patients receiving MAC (35.8 years, range 18-56) was lower than those receiving RIC (48.4 years, range 19-64). Two-year OS was similar for MAC and RIC patients (66% vs 62%, P = 0.17), whereas 2-year progression-free survival was superior in MAC patients (63% vs 50%, P = 0.01) due to fewer relapses. OS was reduced in older patients irrespective of conditioning. Patients with chronic graft-versus-host disease had improved survival due to fewer relapses. OS was unaffected by HCT comorbidity index, donor, cell source or patient/donor cytomegalovirus status. Conclusion RIC protocols have resulted in long-term survival in many patients ineligible for MAC protocols. In our smaller centre, patient age but not conditioning intensity influenced survival, which was equivalent to reports from larger centres. [ABSTRACT FROM AUTHOR]

Summary Mycolic acids are major components of the cell envelope of mycobacteria, such as Mycobacterium tuberculosis, and play an important role in its architecture, impermeability and interaction with the environment. Synthesis of mycolic acids is carried out by two types of fatty acid synthases (FAS) working in concert: type I FAS, a multifunctional enzyme capable of de novo synthesis of medium-chain fatty acids, and type II FAS, responsible for their elongation. In this article we report the identification and characterization of a transcriptional regulator (MabR), whose binding to the FAS-II promoter region was demonstrated in vitro and in vivo. Overexpression and knock-down studies in Mycobacterium smegmatis revealed the repressor nature of MabR, with reduced amounts of FAS-II transcripts and fatty acids in the overproducing strain. Under these conditions, downregulation of fas transcription was also observed, thereby suggesting the existence of cross-talk between the two FAS, mediated by MabR. Finally, the finding that a mabR knock-out mutant could only be obtained in a merodiploid strain of M. smegmatis, confirmed the predicted essentiality, thus implying an essential role for MabR in mycobacterial fatty acid metabolism. [ABSTRACT FROM AUTHOR]

To better understand the personal barriers that limit participation in faecal occult blood test (FOBT) screening for colorectal cancer, non-participants from a recent screening initiative were sent detailed questionnaires, defining their reasons for not participating, as well as how to make screening more attractive. The important barrier was procrastination. The type of FOBT kit offered influenced the reasons for not participating. Convenient FOBT and greater general practitioner involvement may be important for optimizing community acceptance of FOBT-based screening. [ABSTRACT FROM AUTHOR]

One concern over growing herbicide-tolerant crops is that herbicide-tolerance genes may be transferred into the weeds they are designed to control. Brassica napus (oilseed rape) has a number of wild relatives that cause weed problems and the most widespread of these is Sinapis arvensis (charlock). Sinapis arvensis seed was collected from 102 populations across the UK, within and outside B. napus -growing areas. These populations were tested for sexual compatibility with B. napus and it was found that none of them hybridized readily in the glasshouse. In contrast to previous studies, we have found that hybrids can be formed naturally with S. arvensis as the maternal parent. Six diverse B. napus cultivars (Capricorn, Drakkar, Falcon, Galaxy, Hobson and Regent) were tested for their compatibility with S. arvensis but no cultivar hybridized readily in the glasshouse. We were unable to detect gene transfer from B. napus to S. arvensis in the field, confirming the extremely low probability of hybridization predicted from the glasshouse work. [ABSTRACT FROM AUTHOR]

Summary The exercise intensity of horses competing in the cross country phase of an advanced horse trial ( Group 1; n=17) and an advanced 3-day combined training event ( Group 2; n=7) over a similar course on the same day was investigated. Environmental conditions during the trial were cool. Heart rates were continuously recorded at 5 s intervals by a heart rate monitor. Mean ± s.d. heart rates for Group 1 and Group 2 were 167.7 ± 24.0 beats/min and 171.4 ± 19.2 beats/min, respectively, (P>0.05). Plasma lactate concentrations were determined at rest, within 60 s post exercise and 10 min post exercise. Mean lactate concentrations were highest immediately post exercise ( Group 1=15.18 ± 5.79 mmol/l; Group 2=19.10 ± 4.22 mmol/l) and had declined significantly in 10 min ( Group 1=11.15 ± 6.56 mmol/l; Group 2=16.06 ± 6.11 mmol/l). Lactate concentrations were not significantly different between groups at each time period. We concluded that the work effort for the cross country phase was not different between advanced horse trial and 3-day competitions for horses competing under similar conditions during non stressful environmental conditions. [ABSTRACT FROM AUTHOR]

The systems participating in detoxification of reactive oxygen intermediates in Mycobacterium tuberculosis are believed to play a dual role in the biology of this highly adapted human pathogen: (i) they may contribute to the survival of this bacterium in the host; and (ii) alterations in the gene encoding catalase/peroxidase have been linked to this organism's resistance to the front-line antituberculosis drug isoniazid. These relationships prompted us to extend investigations of the oxidative-stress-response systems in M. tuberculosis by analysing the alkyl hydroperoxide reductase gene ahpC and its putative regulator oxyR. Surprisingly, the oxyR gene was found to be inactivated by multiple lesions in M. tuberculosis H37Rv. These alterations were observed in all M. tuberculosis strains tested, and in members of the M. tuberculosis complex: Mycobacterium bovis BCG, Mycobacterium africanum, and Mycobacterium microti. The corresponding region carrying these genes in Mycobacterium leprae, an organism not sensitive to isoniazid, has a complete oxyR gene divergently transcribed from ahpC. An increase in minimal inhibitory concentration for isoniazid was observed upon transformation of M. tuberculosis H37RV with cosmids carrying the oxyR-ahpC region of M. leprae. In keeping with the observed inactivation of oxyR, transcriptional activity of the corresponding region in M. tuberculosis was an order of magnitude lower than that of the oxyR gene from M. leprae. While the loss of this putative regulator of oxidative-stress response in M. tuberculosis is paradoxical considering the fact that survival in host macrophages is regarded as a critical feature of this pathogen, it offers a partial explanation for the exquisite sensitivity of M. tuberculosis to isoniazid. [ABSTRACT FROM AUTHOR]

The nucleotide sequence of cosmid B1790, carrying the Rif-Str regions of the Mycobacterium leprae chromosome, has been determined. Twelve open reading frames were identified in the 36716bp sequence, representing 40% of the coding capacity. Five ribosomal proteins, two elongation factors and the β and β' subunits of RNA polymerase have been characterized and two novel genes were found. One of these encodes a member of the so-called ABC family of ATP-binding proteins while the other appears to encode an enzyme involved in repairing genomic lesions caused by free radicals. This finding may well be significant as M. leprae, an intracellular pathogen, lives within macrophages. [ABSTRACT FROM AUTHOR]

In an attempt to unify the genetic and biological research on Mycobacterium leprae, the aetiological agent of leprosy, a cosmid library was constructed and then ordered by a combination of fingerprinting and hybridization techniques. The genome of M. leprae is represented by four contigs of overlapping clones which, together, account for nearly 2.8Mb of DNA. Several arguments suggest that the gaps between the contigs are small in size and that virtually complete coverage of the chromosome has been obtained. All of the cloned M. leprae genes have been positioned on the contig maps together with the 29 copies of the dispersed repetitive element, RLEP. These have been classified into four groups on the basis of differences in their organization. Several key housekeeping genes were identified and mapped by hybridization with heterologous probes, and the current genome map of this uncultivable pathogen comprises 72 loci. [ABSTRACT FROM AUTHOR]

Linked genes encoding two outer membrane proteins (p76 and a family of proteins, p120) of the bovine pathogen, Haemophilus somnus, were investigated. The p120 group was previously shown to have immunoglobulin-bindlng activity and to react with polyclonal antiserum specific for a 270kDa antigen (p270) which also had Immunoglobulin Fc-binding activity. By Western blotting we showed that the p76 antigen also reacted with this antiserum. The p270, p120, and p76 antigens were undetectable in four serum-sensitive isolates from asymptomatic carriers but were present in the two serum-resistant virulent strains tested. Genes for p120 and p76 were subcloned on non-overlapplng pUC plasmids from a cosmid (pHS1) originally cloned from a serum-resistant strain. In Escherichia coli, plasmid pHS138 expressed p76, while the p120 antigens were produced by pHS140. Southern blots of DNA from the above six strains of H. somnus using probes derived from pHS1 subclones showed that a 13.4kb sequence was missing from the four serum-sensitive strains, but not the two serum-resistant strains. This segment included most of the insert in pHS138 and all of the pHS140 insert. The data indicate that p76 and the p120 proteins are absent from serum-sensitive strains because the coding sequences are missing, raising the possibility of insertion of these genes into the chromosome of both serum-resistant strains, or deletion from the four serum-sensitive strains. [ABSTRACT FROM AUTHOR]

Pulsed-field gel electrophoresis has been used to assess genomic diversity and to identify virulence regions in 10 strains, representing all five serotypes, of the anaerobic pathogen Clostridium perfringens. Detailed physical and gene maps of the ≈ 3.6 Mb circular chromosomes have been established in eight cases and used to deduce a consensus map. With one exception the chromosomal arrangement was relatively constant and map comparison allowed three hypervariable regions to be Identified, One of these was associated with the enterotoxin gene, cpe, which is an important cause of human diarrhoea following the ingestion of food contaminated with C. perfringens. Another variable region spanning the major virulence gene plc, which encodes the cytolytic toxin, α, was located near oriC in all cases whereas the gene for another lethal typing toxin, ε, was borne by an episome. It now seems likely that the serological variations, and the changes in the pathogenic spectrum which constitute the C. perfringens typing system, may be due entirely to the loss, or acquisition, of extrachromosomal genetic elements. [ABSTRACT FROM AUTHOR]

The genome of the causative agent of leprosy, Myco-bacterium leprae, contains at least 28 copies of a dispersed repetitive sequence, RLEP. From nucleotide sequence analysis it was clear that the RLEP element consists of a 545 bp central domain flanked by a 100bp left-end and a 44bp right-end, sometimes associated with a 47 bp extension. The presence of the left and right ends is variable and this allowed three different RLEP configurations to be defined. When the polymerase chain reaction was used to study variation of the central region at least twelve different classes were detected, suggesting that no two RLEP sequences may be identical. Furthermore, they have few features in common with classical bacterial insertion sequences. [ABSTRACT FROM AUTHOR]

In Klebsiella pneumoniae, the mucoid phenotype, which is a virulence factor, is distinct from capsule production. It is positively controlled by a plasmid gene, designated rmpA. When introduced into certain Escherichia coli strains, rmpA induces expression of a mucoid phenotype, which results from overproduction of colanic acid at 30°C but not at 37°C. In E. coli, production of colanic acid is regulated by three genes: rcsA and rcsB which act as positive regulators, and rcsC which is a negative effector. In this work we present evidence that the rmpA gene complemented an rcsA, lon double mutant of E. coli, but not an rcsA, lon+ isolate. This leads to the suggestion that rmpA expressed an rcsA-like activity and like rcsA, was negatively controlled at post-transcriptional level by the Lon protease. The nucleotide sequence of rmpA is reported. No homology could be found between the 27 kiloDalton RcsA protein and the deduced amino acid sequence of the 15.5 kiloDalton RmpA protein. Another gene, rmpB, which was required in E. coli recA isolates for full expression of rmpA at 30X, has been identified on the K. pneumoniae virulence plasmid and shown to encode a 37 kiloDalton protein. Although rmpB was closely linked to rmpA, it was not present on the same transcriptional unit. These results suggested that induction of colanic acid synthesis by the K. pneumoniae virulence gene rmpA, was, at least in E. coli, under the control of the RecA network via rmpB, which may act as a positive regulator of rmpA. We conclude that these plasmid genes may function in K. pneumoniae as regulatory genes controlling the mucoid phenotype, which is itself encoded by the chromosome. [ABSTRACT FROM AUTHOR]

In clinical isolates of Enterobacter cloacae, resistance to the newer β-lactam antibiotics often results from overproduction of a cephalosporinase encoded by the β-lactam-inducible ampC gene. Regulation of ampC is controlled by the divergently expressed activator gene, ampR, and a second unlinked locus. In this presentation we show that although Escherichia coli has lQst its ampR gene it has retained the second regulatory locus and that this comprises the bicistronic ampDE operon. Genetic and biochemical studies define the ampD gene as encoding a repressor for ampC transcription whereas the ampE gene product is a cytoplasmic membrane protein. Inactivation of the AmpD protein by mutation causes massive overproduction of cephalosporinase which, in E. cloacae, can terminate in therapeutic failure. In contrast, toss of AmpE results in a total block in induction, despite the presence of the activator, AmpR. [ABSTRACT FROM AUTHOR]

In enteric bacteria, the expression of many genes encoding various anaerobic electron transfer functions is controlled by FNR, the product of the autoregulated fnr gene. FNR is structurally and functionally homologous to CAP, the catabolite gene activator protein, and increased FNR production strongly stimulates transcription of its target genes. By analysis of RNA produced in vivo the promoters of four FNR-dependent genes were localized and shown to display a common arrangement. A 22bp dyad symmetry was found about 30 nucleotides upstream of the transcriptional startpoints and a similar sequence was shown to overlap the site of transcription initiation in the negatively controlled fnr gene. The consensus sequence for the half site recognized by FNR (AAATTGAT) is only slightly different from that of CAP (AA-TGTGA). Studies with two mutant frd promoters from Escherichia coli, displaying altered regulation and FNR response, provided additional evidence for recognition of this sequence by FNR. [ABSTRACT FROM AUTHOR]

The transcriptional pattern of the 22 min region of the Escherichia coli chromosome containing the linked sulA and ompA genes, which encode an SOS-inducible inhibitor of cell division and a constitutively expressed, major outer membrane protein, respectively, has been re-examined. During normal growth, the sulA gene was repressed whereas the ompA gene produced a stable 1250 nucleotide transcript. Counter-transcription of sulA occurred from a promoter situated in the sulA-ompA intergenic region and the product of this transcriptional circuit, named isf, is a 353 nucleotide untranslated RNA. Since the isf RNA is complementary to the 3′-end of the sulA transcript, it could modulate sulA function by serving as an anti-messenger. On induction of the SOS-response, massive transcription of sulA took place, resulting in the ‘silencing’ of the isf gene, production of an abundant -615 nucleotide sulA mRNA and a novel hybrid transcript of ∼2100 nucleotides encoding both the SulA and OmpA proteins. Production of the latter RNA species, caused by transcription reading through the sulA terminator, the intergenic region and the coding sequences, was accompanied by a decrease in the abundance of the ompA mRNA as a result of promoter occlusion. However, the amount of OmpA protein produced was only slightly reduced. [ABSTRACT FROM AUTHOR]

The nucleotide sequence of a 6.5 kilobasepair chromosomal DNA fragment encoding the anaerobic dimethylsulphoxide (DMSO) reductase operon of Escherichia coli has been determined. The DMSO reductase structural operon was shown to consist of three open reading frames, namely dmsABC, encoding polypeptides with predicted molecular weights of 87350, 23070, and 30789 Daltons, respectively. The DMS A polypeptide displayed a high degree of amino acid sequence homology with the single-subunit enzyme, biotin sulphoxide reductase (bisC) and with formate dehydrogenase (fdhF), suggesting that the active site and molybdopterin cofactor binding site that is common to these enzymes is located in the DMS A subunit. A comparison of the predicted N-terminal amino acids of the dmsA gene product to those of the 82600 subunit of purified DMSO reductase indicated that post-translational processing of a 16 amino acid peptide at the amino terminus of DMS A had occurred. The DMS B polypeptide contains 16 cysteine residues organized in four clusters, two of which are typical of 4Fe-4S binding domains. The DMS C polypeptide is composed of eight segments of hydrophobic amino acids of appropriate length to cross the cytoplasmic membrane, suggesting that this subunit functions to anchor the enzyme to the membrane. [ABSTRACT FROM AUTHOR]

Expression of a 4kb segment of the bacteriocinogenic plasmid, plP404, from Clostridium perfringens is inducible by UV-irradiation. DNA sequence analysis revealed that this region contains three genes: uviA, uviB and bcn encoding the bacteriocin BCN5. Biochemical studies with mRNAs showed that expression was controlled at the transcriptional level and that the genes were organized in two independent transcriptional units, uviAB and bcn, both directed by tandem promoters inducible by UV light. The bcn gene is transcribed from three promoters (P1, P2, P3) while transcription of uviAB is directed by two promoters (P4, P5). With the exception of P4, which bears some resemblance to the consensus eubacterial promoter sequence, none of these promoters was recognized in vitro by the major forms of RNA polymerase from C. perfringens. Bacillus subtilis or Escherichia coli. Promoters P1, P3 and P5, which show striking homology with each other, contain unusual sequences in the ‘-35’ and ‘-10’ regions known to be recognized by RNA polymerase and this might indicate positive control. [ABSTRACT FROM AUTHOR]

Clostridium perfringens strain CPN50 harbours a 10.2 kb plasmid known as plP404 which, in addition to a set of UV-inducible genes involved in bacteriocin production, carries res, a gene probably encoding a site-specific recombinase. The RES protein is highly homologous to the resolvases of transposons from both Gram-negative and Gram-positive bacteria as well as enzymes involved in site-specific DNA inversion. A likely role for the RES protein would be to stabilize plP404 by reducing the number of plasmid multimers resulting from homologous recombination. A putative resolution site for RES action was found overlapping the res promoter. Phylogenetic analysis of the primary structures of ten site-specific recombinases suggested a common descent and showed the RES protein to be closest to the resolvase encoded by Tn917 from Streptococcus faecalis. [ABSTRACT FROM AUTHOR]

The nucleotide sequences of the glpT gene of Escherichia coli and its regulatory region have been elucidated and the primary structure of the glycerol-3-phosphate transport protein deduced. Extensive amino acid sequence homology was found with two other cytoplasmic membrane proteins: the functionally related hexose-6-phosphate transport protein, and the UHPC protein involved in regulating hexose-6-phosphate uptake. Although no significant amino acid sequence homology was found with other transport proteins, such as the arabinose, citrate, glucose, melibiose, lactose or xylose transporters, all of these proteins share a common secondary structure arrangement with the GLP T protein as they apparently contain twelve membrane-spanning alpha-helical segments. The promoter for glpT was located by transcript mapping and shown to overlap a site to which catabolite activator protein binds in vitro. These findings Indicate how catabolite repression may be mediated but do not explain its physiological significance in glycerol metabolism. [ABSTRACT FROM AUTHOR]

Six murine L cell lines expressing five different human cell surface antigens have been prepared by DNA-mediated gene transfer.Ltk-cells were transfected with calcium phosphate co-precipitates of human genomic DNA and a plasmid containing the Herpes simplex thymidine kinase gene. After HAT selection, transfectants expressing specific cell surface antigens were identified by in situ immune rosetting using monoclonal antibodies. In this way, transfected cell lines expressing the CD9 antigen, the CD31 antigen (two lines), a unique platelet antigen, an X-linked antigen (RI), and a previously unreported monocyte antigen 11 D1 were prepared. These cell lines have proved useful in the definitive assignment of monoclonal antibodies to specific CD groups. In addition, they provide a source of mRNA for use in expression cloning of the genes for these antigens. [ABSTRACT FROM AUTHOR]