Embracing unity at OMERACT: Valuing equity, promoting diversity, fostering inclusivity

OBJECTIVE

To increase awareness and understanding of the principles of Equity, Diversity, and Inclusivity (EDI) within Outcome Measures in Rheumatology's (OMERACT) members. For this, we aimed to obtain ideas on how to promote and foster these principles within the organization and determine the diversity of the current membership in order to focus future efforts.

METHODS

We held a plenary workshop session at OMERACT 2023 with roundtable discussions on barriers and solutions to increased diversity within OMERACT. We conducted an anonymous, web-based survey of members to record characteristics including population group, gender identity, education level, age, and ability.

RESULTS

The workshop generated ideas to increase diversity of participants across the themes of building relationships [12 topics], materials and methods [5 topics], and conference-specific [6 topics]. Four hundred and seven people responded to the survey (25 % response rate). The majority of respondents were White (75 %), female (61 %), university-educated (94 %), Christian (42 %), spoke English at home (60 %), aged 35 to 55 years (50 %), and did not report a disability (64 %).

CONCLUSION

OMERACT is committed to improving its diversity. Next steps include strategic recruitment of members to the EDI working group, drafting an EDI mission statement centering equity and inclusivity in the organization, and developing guidance for the OMERACT Handbook to help all working groups create actionable plans for promoting EDI principles.

Coalition for Health and Gender Equity (CHANGE)-a protocol for a global cross-sectional survey of health and gender equity in rheumatology

Objectives

The primary aim of the CHANGE survey is to determine the current state of gender equity within rheumatology, and secondarily, to review the physician perspective on bullying, harassment and equipoise of opportunities within rheumatology.

Methods

The CHANGE e-survey is a cross-sectional self-reported questionnaire adapted from EULAR's gender equity in academic rheumatology task force. The survey was launched in January 2023; it is available in six languages and distributed widely via rheumatology organizations and social media. Eligible participants include rheumatologist physicians and rheumatology health-care professionals. Survey responses will undergo descriptive analysis and inter-group comparison aiming to explore gender-based discrimination using logistic regression, with subgroup analyses for country/continent variations.

Conclusion

This e-survey represents a comprehensive global initiative led by an international consortium, aimed at exploring and investigating the gender-related disparities and obstacles encountered by rheumatologists and rheumatology health-care professionals across diverse communities and health-care environments. By pursuing this initiative, we aim to take the broader rheumatology community a step closer to understanding the underlying origins of inequities and their determinants. Such insights are pivotal in identifying viable interventions and strategies to foster gender equity within the field. Ultimately, our collective objective is to ensure equitable access to opportunities for every individual, irrespective of gender, thereby promoting inclusivity and fairness across the entire spectrum of professional practice and career development.

Patient-reported outcomes of upadacitinib versus abatacept in patients with rheumatoid arthritis and an inadequate response to biologic disease-modifying antirheumatic drugs: 12- and 24-week results of a phase 3 trial

Background

In previous clinical trials, patients with active rheumatoid arthritis (RA) treated with upadacitinib (UPA) have improved patient-reported outcomes (PROs). This post hoc analysis of SELECT-CHOICE, a phase 3 clinical trial, evaluated the impact of UPA vs abatacept (ABA) with background conventional synthetic disease-modifying antirheumatic drugs (csDMARDs) on PROs in patients with RA with inadequate response or intolerance to biologic disease-modifying antirheumatic drugs (bDMARD-IR).

Methods

Patients in SELECT-CHOICE received UPA (oral 15 mg/day) or ABA (intravenous). PROs evaluated included Patient Global Assessment of Disease Activity (PtGA) by visual analog scale (VAS), patient’s assessment of pain by VAS, Health Assessment Questionnaire Disability Index (HAQ-DI), morning stiffness duration and severity, 36-Item Short Form Health Survey (SF-36), Functional Assessment of Chronic Illness Therapy-Fatigue (FACIT-F), Work Productivity and Activity Impairment (WPAI), and EQ-5D 5-Level (EQ-5D-5L) index score. Least squares mean (LSM) changes from baseline to weeks 12 and 24 were based on an analysis of covariance model. Proportions of patients reporting improvements ≥ minimal clinically important differences (MCID) were compared using chi-square tests.

Results

Data from 612 patients were analyzed (UPA, n=303; ABA, n=309). Mean age was 56 years and mean disease duration was 12 years. One-third received ≥2 prior bDMARDs and 72% received concomitant methotrexate at baseline. At week 12, UPA- vs ABA-treated patients had significantly greater improvements in PtGA, pain, HAQ-DI, morning stiffness severity, EQ-5D-5L, 2/4 WPAI domains, and 3/8 SF-36 domains and Physical Component Summary (PCS) scores (P<0.05); significant differences persisted at week 24 for HAQ-DI, morning stiffness severity, SF-36 PCS and bodily pain domain, and WPAI activity impairment domain. At week 12, significantly more UPA- vs ABA-treated patients reported improvements ≥MCID in HAQ-DI (74% vs 64%) and SF-36 PCS (79% vs 66%) and 4/8 domain scores (P<0.05).

Conclusions

At week 12, UPA vs ABA treatment elicited greater improvements in key domains of physical functioning, pain, and general health and earlier improvements in HAQ-DI. Overall, more UPA- vs ABA-treated patients achieved ≥MCID in most PROs at all timepoints; however, not all differences were statistically significant. These data, however, highlight the faster response to UPA treatment.

Trial registration

NCT03086343, March 22, 2017.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13075-022-02813-x.

The Evolving Workforce in Rheumatology: The Effect of Gender

Population shifts in the workforce have been noted for the past few decades. In the United States, the number of people aged 65 and older is expected to double, reaching almost a quarter of the population.1 By 2045, the US is expected to experience a demographic shift, with an increase in the percentage of minority populations to greater than 50%.

Understanding differences between men and women with axial spondyloarthritis

Axial spondyloarthritis (axSpA) is a chronic inflammatory immune-mediated disease resulting in inflammatory low back pain and other inflammatory manifestations in peripheral joints and entheses. AxSpA encompasses both ankylosing spondylitis (AS), in which patients present with definitive sacroiliitis visible on radiographic imaging, as well as nonradiographic axSpA (nr-axSpA), in which such changes may not be discernable. Emerging evidence suggests that women and men experience axSpA differently. Although the prevalence of AS is approximately 2- to 3- fold higher in men than in women, nr-axSpA occurs with roughly equal frequency in women and men. The goal of this review is to increase awareness of sex differences in axSpA by exploring the distinct manifestations of disease and disease characteristics in women, the overall clinical burden, recommendations for diagnosis, and potential treatment options. We summarize and contextualize the results of recent studies that illuminate sex differences in nr-axSpA and AS, including differences in disease manifestation and progression. It is important that sex differences in axSpA are understood and considered when diagnosing and treating the spectrum of axSpA, including AS and nr-axSpA.

Evaluation of unfractionated heparin versus low-molecular-weight heparin and fondaparinux for pharmacologic venous thromboembolic prophylaxis in critically ill patients with cancer

Essentials Critically ill cancer patients require pharmacologic prophylaxis for venous thromboembolism (VTE). Patients from 566 hospitals in the United States between 2010 and 2014 were included. Low-molecular-weight heparin (LMWH) prophylaxis was not associated in a reduction of VTE rates. LMWH prophylaxis was associated with a reduction in bleeding and heparin induced thrombocytopenia. SUMMARY: Background Critically ill patients with cancer are at increased risk of venous thromboembolism (VTE) from physical and cellular factors, requiring pharmacologic prophylaxis to reduce the risk of VTE. Objectives To assess whether low-molecular-weight heparin (LMWH) prophylaxis reduces in-hospital rates of VTE or improves clinical outcomes compared with unfractionated heparin (UFH) prophylaxis in critically ill patients with cancer. Methods We used a propensity-matched comparative-effectiveness cohort from the Premier Database. Patients aged 18 years or older with a primary diagnosis of cancer, intensive care unit admission and VTE prophylaxis within 2 days of admission between 1 January 2010 and 31 December 2014 were included. Patients were divided into LMWH or UFH prophylaxis groups. Results A total of 103 798 patients were included; 75 321 (72.6%) patients received LMWH and 28 477 (27.4%) patients received UFH. Propensity analysis matched (2 : 1) 42 343 LMWH patients and 21 218 UFH patients. Overall, LMWH was not associated with a decreased incidence of VTE (5.32% vs. 5.50%). LMWH prophylaxis was associated with a reduction in pulmonary embolism (0.70% vs. 0.99%), significant bleeding (13.3% vs. 14.8%) and heparin-induced thrombocytopenia (HIT) (0.06% vs. 0.19%). In non-metastatic solid disease, LMWH was associated with decreased VTE (4.27% vs. 4.84%) and PE (0.47% vs. 0.95%). Conclusions The use of an LMWH for VTE prophylaxis was not associated with a reduction in the incidence of in-hospital VTE as compared with UFH, but was associated with significant reductions in PE, clinically important bleeding events, and incidence of HIT in critically ill patients with cancer.

The potential impact of monitoring disease activity biomarkers on rheumatoid arthritis outcomes and costs

Rheumatoid arthritis (RA) management requires monitoring of disease activity to determine course of treatment. Global assessments are used in clinical practice to determine RA disease activity. Monitoring disease activity via biomarkers may also help providers optimize biologic and nonbiologic drug use while decreasing overall drug spend by delaying use of expensive biologic therapies. By testing multiple biologic domains at the same time, a multibiomarker disease activity test may have utility in RA patient management, through improved intra- and inter-rater reliability. This report provides a comprehensive review of studies of objective measures, single biomarkers and multibiomarker disease activity tests as disease activity measures to decrease uncertainty in treatment decisions, and of biomarkers’ potential impact on economic and clinical outcomes of treatment choices.

Patient Expectations and Perceptions of Goal-setting Strategies for Disease Management in Rheumatoid Arthritis

OBJECTIVE

To identify how patients perceive the broad effect of active rheumatoid arthritis (RA) on their daily lives and indicate how RA disease management could benefit from the inclusion of individual goal-setting strategies.

METHODS

Two multinational surveys were completed by patients with RA. The "Good Days Fast" survey was conducted to explore the effect of disease on the daily lives and relationships of women with RA. The "Getting to Your Destination Faster" survey examined RA patients' treatment expectations and goal-setting practices.

RESULTS

Respondents from all countries agreed that RA had a substantial negative effect on many aspects of their lives (work productivity, daily routines, participation in social and leisure activities) and emotional well-being (loss of self-confidence, feelings of detachment, isolation). Daily pain was a paramount issue, and being pain- and fatigue-free was considered the main indicator of a "good day." Setting personal, social, and treatment goals, as well as monitoring disease progress to achieve these, was considered very beneficial by patients with RA, but discussion of treatment goals seldom appeared to be a part of medical appointments.

CONCLUSION

Many patients with RA feel unable to communicate their disease burden and treatment goals, which are critically important to them, to their healthcare provider (HCP). Insights gained from these 2 surveys should help to guide patients and HCP to better focus upon mutually defined goals for continued improvement of management and achievement of optimal care in RA.

Stimulation of matrix formation in rabbit chondrocyte cultures by ascorbate. 1. Effect of ascorbate analogs and beta-aminopropionitrile

The most consistent effects of 0.2 mM L-ascorbate on monolayer cultures of rabbit articular chondrocytes were a diversion of incorporated radiosulfate into a pericellular matrix and enhancement of cell proliferation. Only with certain batches of fetal bovine serum (FBS) was there a cell-for-cell increase of proteoglycan synthesis. These actions increased as the cell inoculum rose from 0.5 to 2 x 10(5) cells/T25 flask. Maximal effects of ascorbate and D-isoascorbate were found over a range of 0.05-0.2 mM. L-Dehydroascorbic acid was less effective than either, and no stimulatory action was exerted by L-cysteine, glutathione, dithiothreitol, methylene blue, or phenazine methosulfate. Ascorbate increased the hypro:pro ratio of newly synthesized proteins. beta-Aminopropionitrile (1 mM) reduced the proportion of [3H]hydroxyproline and [35S]O4-proteoglycans in the ascorbate-supplemented matrix 31 and 7%, respectively. In corresponding electronmicrographs, the number of pericellular filaments was reduced. We conclude: (a) Ascorbate has a general anabolic effect on chondrocytes in culture and enhances matrix assembly through mechanisms other than its redox function; (b) deposition of proteoglycans in the matrix is not simply the result of mechanical entrapment by allysine- or hydroxyallysine-derived cross-linking of collagen; and (c) contradictory reports on the subject result from variations in the serum employed, inoculum density, and concentration of ascorbate.

Resistance to Phytophthora citrophthora and P. parasitica and Nursery Characteristics of Several Citrus Rootstocks

Studies were conducted to compare existing and potential citrus rootstocks with respect to resistance to root rot and gummosis caused by Phytophthora citrophthora and P. parasitica in greenhouse and growth chamber experiments and horticultural performance under simulated nursery conditions. Depending upon rootstock and experiment, mean root weights resulting from inoculation with P. citrophthora were 27 to 96% lower than the comparable controls. In similar experiments with the same rootstocks, inoculation with P. parasitica resulted in root weights that were 38 to 95% less than weights of the noninoculated controls. During 1994 or 1995, mean root weight reduction compared with noninoculated plants among Citrus macrophylla, rough lemon, C. volkameriana, and Sunki mandarin × Flying Dragon trifoliate (62-109-19) attributable to P. citrophthora and mean root weight reduction among C. macrophylla, C. volkameriana, rough lemon, Sacaton citrumelo, Sunki mandarin × Flying Dragon trifoliate (62-109-19), African shaddock × Rubidoux trifoliate, and Shekwasha mandarin × English trifoliate attributable to P. parasitica were significantly less than those recorded for all other tested rootstocks. Rootstocks that sustained a low percentage of root weight reduction generally experienced a low percentage of shoot weight reduction and survived longer as well. In evaluation of resistance to gummosis, depending on rootstock and experiment, the mean length of stem lesions caused by P. citrophthora on rootstocks ranged from 0.2 to 25.0 mm, whereas values for P. parasitica ranged from 0.2 to 18.5 mm. Stem lesions smaller than 5 mm in length were recorded for 21 and 14 of 36 different rootstocks inoculated with P. citrophthora and P. parasitica, respectively. On the other hand, P. citrophthora and P. parasitica caused stem lesions of at least 10 mm in length on 8 and 16 citrus rootstocks, respectively. Desirable nursery characteristics, including vigorous growth, minimal branching, and high leaf chlorophyll content, were demonstrated most prominently by Gomiri rough lemon, C. volkameriana, and Benton citrange, and to a lesser degree by some other rootstocks. Possible factors that could account for inconsistent classification of some citrus rootstocks as susceptible or resistant to Phytophthora root rot and gummosis are discussed.

Comparative analyses of the latency-associated transcript promoters from herpes simplex virus type 1 strains H129, +GC and KOS-63

We have analyzed the activity of a specific portion of the latency-associated transcript (LAT) promoter of three strains of herpes simplex virus type 1 (HSV-1) in neuronal and non-neuronal cell types. Restriction fragments containing the LAT promoter sequences and the 5'-end of the LATs were isolated from HSV-1 strains H129, +GC and KOS-63, sequenced and cloned into a chloramphenicol transferase (CAT) plasmid vector. These vectors were separately assayed for CAT production in human (SknSH) and mouse (C-1300) neuroblastoma cell lines and a human continuous cell line (HeLa). Strain KOS-63 contained a C to T base substitution within the LAT promoter binding factor element upstream of the cAMP response element binding sequence. In replicate experiments, in which the construct DNA was used for transfection, the CAT constructs from strains H129 and +GC functioned equally well in all three cell lines. In contrast, the strain KOS-63 CAT construct functioned significantly better in HeLa cells than in neuroblastoma cell lines and better than the identical CAT constructs from strains H129 and +GC. In addition, the construct from strain KOS-63 functioned less well in the human neuroblastoma cell line than in HeLa or C-1300 neuroblastoma cells. When LAT expression was examined directly in vivo by in situ hybridization, strain KOS-63 produced slightly less LAT RNA than strain H129 within trigeminal ganglionic neurons of latently infected rabbits. However, utilizing competitive gel-shift assays, DNA fragments containing the LAT promoter binding element from all three strains bound equivalent amounts of HeLa cell nuclear proteins. Together, these results suggest that the activity expressed by the strain KOS-63 LAT promoter in vivo and in vitro may relate to positive or negative effects of DNA binding proteins on LAT transcription, and that these effects are cell-type dependent.

Distribution of nitrogen and radiation use efficiency in peanut canopies

The allocation pattern of leaf nitrogen throughout a crop canopy can theoretically affect crop photosynthetic performance and radiation use efficiency (RUE). No information is available on the existence of leaf nitrogen gradients in peanut (Arachis hypogaea L.) canopies, nor on how these gradients might impact on RUE. Peanut crops (cv. Tifton-8) were grown in warm and cool environments, and the canopy profiles of leaf area index, light interception, specific leaf weight (SLW), leaf nitrogen concentration (LNC) and specific leaf nitrogen (SLN) were examined at 73 and 112 days after planting. Crop RUE was also measured during this period. There was a marked decline in SLN from the top to the base of the canopy in both environments. The gradient in SLN occurred due to changes in SLW and LNC in the warm environment, but only due to changes in SLW in the cool environment. The gradient appeared to be largely controlled by the light environment within the canopy, as evidenced by the commonality (across environments) of the relationship between SLN and cumulative light interception throughout the canopy. Radiation use efficiency was 33% higher in the crop grown in the warm compared to the cool environment, suggesting that cool temperatures can limit RUE in peanut. For the crop at the warm site, RUE was 32% higher than the theoretical RUE assuming a uniform SLN distribution in the canopy. It is suggested that the existence of non-uniform SLN distribution in the canopy may allow enhanced RUE compared to canopies with uniform SLN distribution.

A theoretical analysis of nitrogen and radiation effects on radiation use efficiency in peanut

Radiation use efficiency (RUE) of well-watered crops, measured as grams of biomass accumulated for each megajoule of intercepted total solar radiation, is affected by the level of leaf nitrogen in the canopy and has been related to the canopy specific leaf nitrogen (SLN; g N m-2 leaf area). A number of field experiments on peanut have measured RUE values greater than current theories predict on the basis of their canopy SLN levels. It is possible that these discrepancies between measured and theoretical values may be caused by non-uniform distribution of SLN in the canopy, incident radiation level, and/or the influence of diffuse radiation. In this study, we developed a theoretical framework to predict the consequences of these factors on RUE in peanut and used it to explain the causes of discrepancies between theory and practice. The framework is structured to determine photosynthesis of a layered crop canopy by distributing incident radiation among sunlit and shaded leaves in each layer. It allows for variation in incident direct and diffuse radiation associated with location (latitude), time of year, time of day, and atmospheric condition, which is expressed as the degree of transmission of extra-terrestrial radiation. It also allows for variation in photosynthetic capacity associated with average SLN of the canopy and its distribution in the canopy. Daily canopy photosynthesis, intercepted radiation, and RUE are obtained by numerical integration of instantaneous values calculated at specific times of the day. The framework predicted experimentally determined RUE values accurately and quantified the contribution of each major factor to variation in RUE. On clear days, with high canopy SLN, RUE was predicted to be 1.l g MJ-1. The major cause of previous underestimation of RUE was found to be variation in RUE associated with the level of incident radiation flux density as affected by the degree of atmospheric transmission. RUE increased by up to 0.4 g MJ-1 as atmospheric transmission decreased from 0.75 (clear sky) to 0.35 (heavy cloud). However, varying incident radiation by changing time of year or latitude did not affect RUE. Partitioning incident radiation into direct and diffuse components and consideration of canopy gradients in SLN both had significant effects on RUE, but of a lesser magnitude than effects of degree of atmospheric transmission. The former caused increases in RUE of up to 0.15 g MJ-l, while the latter caused increases of up to 0.13 g MJ-1 at low canopy SLN. Hence, by quantifying the understanding of plant physiological processes and integrating appropriately to the canopy scale, this theoretical framework has explained the causes of discrepancies between measured RUE and previous theoretical estimates.

The N2-fixing capacity of peanut cultivars with differing assimilate partitioning characteristics

The contribution of symbiotic N2 fixation to the total N budget of irrigated crops of peanut (Arachis hypogaea L.) during vegetative and reproductive growth was investigated using four peanut cultivars with differing patterns of dry matter (DM) partitioning to developing pods. Estimates of NZ fixation were obtained with the 15N natural abundance procedure by using a non-nodulating peanut genotype as a non-N2-fixing reference plant. Partitioning was assessed on the basis of vegetative DM equivalents, with adjustments to pod DM based on relative synthesis costs of vegetative and pod DM. Cultivars differed in crop duration, DM production and yield of pods and kernels. Despite large differences in derived DM partitioning coefficients among cultivars (0.68 to 1.03), both total crop N and fixed N increased as a constant proportion of accumulated, energy-adjusted DM. Crop duration was the primary factor determining both total crop N and fixed N. In addition to fixation, all cultivars continued to accumulate soil mineral N throughout the season. However, in all cultivars except TMV-2, crop N uptake during reproductive growth was insufficient to meet the demands of developing pods and N was renlobilized from vegetative plant parts. Remobilized N was almost exclusively N derived originally from N2 fixation. Despite relatively high levels of N2 fixation (from 140 to 210 kg N ha-1, depending on crop duration), all cultivars except Virginia Bunch showed a negative apparent N balance when the amounts of N2 fixed were compared to N removed in pods at final harvest. This was primarily due to high N harvest indices (0.62 to 0.73), and is likely to be a feature of many recently released, high yielding cultivars.

22-Oxacalcitriol: dissection of 1,25(OH)2D3 receptor-mediated and Ca2+ entry-stimulating pathways

22-Oxa-1,25-dihydroxyvitamin D3 (oxacalcitriol, or OCT) is a bioactive analogue of 1 alpha,25-dihydroxyvitamin D3 [1,25(OH)2D3] with lower calcemic activity than the parent compound. We investigated the ability of OCT to stimulate 1) genomic pathways mediated by nuclear receptors for 1,25(OH)2D3 versus 2) nongenomic pathways mediated by voltage-sensitive Ca2+ channels in growth phase rat osteosarcoma cells (ROS 17/2.8) and in chick intestine. Effects on nuclear receptor-mediated pathways were evaluated by measuring the ability of OCT to compete with [3H]1,25(OH)2D3 for soluble receptors. We also measured the ability of OCT to increase mRNA encoding osteoblast marker proteins osteopontin (OPN) and osteocalcin (OCN), which are both increased by 1,25(OH)2D3. Effects on Ca2+ entry into osteoblasts were measured using 45Ca2+ influx assays. The rapid stimulation of calcium absorption (transcaltachia) in chick intestine treated with OCT also was measured. We found that OCT bound to the nuclear receptor with lower binding affinity [relative competitive index (RCI) = 48.1 for ROS 17/2.8; RCI = 14.8 for chick intestine] than 1,25(OH)2D3 (RCI = 100). Like 1,25(OH)2D3, OCT increased mRNA levels of OPN and OCN in ROS 17/2.8 cells over a 48-h period. In contrast, OCT had no effect on transmembrane influx of 45Ca2+ across ROS cell membranes, whereas uptake was stimulated within 1 min by 1 nM 1,25(OH)2D3. In transcaltachia assays in perfused duodenum, OCT stimulated absorption with a maximum response at 6.5 nM.(ABSTRACT TRUNCATED AT 250 WORDS)

Irish setter dogs affected with rod/cone dysplasia contain a nonsense mutation in the rod cGMP phosphodiesterase beta-subunit gene

Irish setter dogs affected with a rod/cone dysplasia (locus designation, rcd1) display markedly elevated levels of retinal cGMP during postnatal development. The photoreceptor degeneration commences approximately 25 days after birth and culminates at about 1 year when the population of rods and cones is depleted. A histone-sensitive retinal cGMP phosphodiesterase (PDE; EC 3.1.4.35) activity, a marker for photoreceptor PDEs, was shown previously to be present in retinal homogenates of immature, affected Irish setters. Here we report that, as judged by HPLC separation, this activity originates exclusively from cone photoreceptors, whereas rod PDE activity is absent. An immunoreactive product the size of the PDE alpha subunit, but none the size of the beta subunit, can be detected on immunoblots of retinal extracts of affected dogs, suggesting a null mutation in the PDE beta-subunit gene. Using PCR amplification of Irish setter retinal cDNA, we determined the complete coding sequence of the PDE beta subunit in heterozygous and affected animals. The affected PDE beta-subunit mRNA contained a nonsense amber mutation at codon 807 (a G-->A transition converting TGG to TAG), which was confirmed to be present in putative exon 21 of the affected beta-subunit gene. The premature stop codon truncates the beta subunit by 49 residues, thus removing the C-terminal domain that is required for posttranslational processing and membrane association. These results suggest that the rcd1 gene encodes the rod photoreceptor PDE beta subunit and that a nonsense mutation in this gene is responsible for the production of a nonfunctional rod PDE and the photoreceptor degeneration in the rcd1/rcd1 Irish setter dogs.

Improved binding of acidic bone matrix proteins to cationized filters during solid phase assays

A number of commercially available matrix filter supports have been designed for the immobilization of proteins following either electrotransfer from sodium dodecyl sulfate (SDS) polyacrylamide gels or direct application during dot blotting assays. These matrices differ with respect to chemical composition, charge, pore size, and degree of hydrophobicity. It follows that the properties of the protein(s) of interest will greatly influence the degree to which they interact with and ultimately bind to various filters. Acidic bone proteins contain diverse post-translational modifications that influence their interactions with solid phase matrices such as those used in immunoblotting (Western or dot blotting) or ion binding (overlay) procedures. This communication describes the results of a study comparing binding of various mixtures of non-collagenous acidic bone matrix phosphoproteins as well as purified osteopontin and osteocalcin to various filters including nitrocellulose and cationized paper or nylon. Based on our findings, we recommend the use of cationized filters for solid phase assays requiring the binding of these acidic macromolecules to background supports.

Plant population studies on peanut (Arachis hypogaea L.) in subtropical Australia. 1. Growth under fully irrigated conditions

Effects of plant density and spatial arrangement on growth and yield responses of 4 peanut cultivars were examined under fully irrigated conditions at Kingaroy, south-eastern Queensland (26�33'S., 151�50'E.). Cultivars represented either the Spanish or Virginia botanical type. Spanish cultivars had either very early (Chico) or early (McCubbin) maturity, while Virginia cultivars had either medium (Early Bunch) or very late (Mani Pintar) maturity. The interaction of plant density (44 000-376 000 plants/ha) with sowing date was assessed in 3 sowings in 1984-85 (S1, 1 November; S2, 5 December; S3, 15 January), with a further sowing in 1985-86 (S4, 21 November). The interaction of plant density and spatial arrangement was assessed in 1985-86. Total dry matter (TDM) and pod yields showed highly significant (P<0.01) linear and quadratic responses to increasing plant density. Cultivars differed in their response to density. McCubbin, Early Bunch and Mani Pintar showed no responses to increased density above 88 000 plants/ha, while maximum TDM and pod yields of Chico were recorded at 352 000 plants/ha. Sowing date had no significant effect on the response of any cultivar to plant density. However, all cultivars except Chico produced significantly less TDM and pod yield in S3, due to cool temperatures and/or frosts terminating growth. A 1 : 1 (square) planting arrangement produced significantly greater pod yields and more TDM than the conventional commercial practice of rows 90 cm apart. Planting in a double-row arrangement (20 cm between 2 rows) based on 90 cm centres produced intermediate pod and TDM yields. A simple model was used to describe the effects of plant density and sowing date on yield, and proved useful for highlighting differences among cultivars and sowing dates. A limitation of the model was a tendency to overestimate pod yield at low plant density in Spanish cultivars, where the harvest index declined at very low plant densities.

Physiological analysis of peanut cultivar response to timing and duration of drought stress

Pod yield response of two spanish (McCubbin and Red Spanish) and two virginia (Virginia Bunch and Q18801) cultivars were compared under a range of irrigation treatments applied at different growth stages on a Xanthozem soil in a subtropical environment in south-east Queensland. Detailed growth and soil water use measurements were taken on a fully irrigated treatment and a treatment which received no rainfall after 83 days after planting (DAP). Soil water deficits occurring during the flowering to the start of pod growth phase (R/I) significantly reduced pod yields (range, 17-25%) relative to the well-watered control plots (I/I) for all cultivars. Where crops were irrigated until 83 DAP, then crop water deficits occurred throughout the pod growth phase (I/R), a significant cultivar by irrigation treatment interaction was observed for pod yield. The greatest reduction in yield occurred when severe stress occurred during the pod filling phase (Sh). Significant cultivar variation in pod yield was apparent. Differences in pod yield within this treatment were analysed in terms of a simple framework where pod yield is a function of transpired water (T), transpiration efficiency (TE) and harvest index ( H ) . Estimates of TE derived from measurements of carbon isotope discrimination in leaves indicated only small variation in TE, and suggest this trait contributed little to pod yield variation in the cultivars used in this experiment. Variation in pod yield among the four cultivars was largely a result of differences in harvest index characteristics.

Bacterial phospholipid hydrolysis enhances the destruction of Escherichia coli ingested by rabbit neutrophils. Role of cellular and extracellular phospholipases

Escherichia coli ingested by PMN are promptly growth arrested but undergo limited destruction. We have studied bacterial phospholipid hydrolysis as a possible limiting factor in the disassembly of ingested E. coli, comparing the fates, during phagocytosis by rabbit peritoneal exudate PMN, of three isogenic strains, differing in their content of the pldA gene encoding the principal E. coli phospholipase A (PLA), i.e., pldA-, pldA+, pldA (the latter strain bearing the pldA gene in a multicopy plasmid resulting in a 20-fold increase in PLA content). Ingestion and growth inhibition (greater than 99% within 15 min) were the same for the three strains, but phospholipid degradation differed according to bacterial PLA content: pldA up to 60%, pldA+ up to 30%, and pldA- up to 20%. Since the pldA- strain has no activatable PLA, phospholipid degradation in this strain demonstrates the action of a PMN PLA. Added PLA2-rich ascitic fluid (AF) or purified AF PLA2 increased the rate and extent of degradation of the pldA- strain, provided the enzyme was added before ingestion was complete. 125I-AF-PLA2 binds to both E. coli and PMN and thus can enter the vacuole during phagocytosis. Although up to 50-fold more AF-PLA2 than the PLA2 content of the PMN could be loaded into the PMN in this way, degradation of pldA- E. coli did not exceed 30%. Increased phospholipid degradation had no effect on the degradation of bacterial macromolecules. In contrast, bacterial disassembly manifest as structural disorganization, release of bacterial protein derived material, and inhibition of protein synthesis were markedly enhanced when greater than 50% of prelabelled bacterial phospholipids were degraded. These findings reveal a link between envelope phospholipid degradation and overall bacterial destruction, suggesting therefore that factors limiting PLA action limit the destruction of E. coli ingested by PMN.

A calcium-binding, asparagine-linked oligosaccharide is involved in skeleton formation in the sea urchin embryo

We have previously identified a 130-kD cell surface protein that is involved in calcium uptake and skeleton formation by gastrula stage embryos of the sea urchin Strongylocentrotus purpuratus (Carson et al., 1985. Cell. 41:639-648). A monoclonal antibody designated mAb 1223 specifically recognizes the 130-kD protein and inhibits Ca+2 uptake and growth of the CaCO3 spicules produced by embryonic primary mesenchyme cells cultured in vitro. In this report, we demonstrate that the epitope recognized by mAb 1223 is located on an anionic, asparagine-linked oligosaccharide chain on the 130-kD protein. Combined enzymatic and chemical treatments indicate that the 1223 oligosaccharide contains fucose and sialic acid that is likely to be O-acetylated. Moreover, we show that the oligosaccharide chain containing the 1223 epitope specifically binds divalent cations, including Ca+2. We propose that one function of this negatively charged oligosaccharide moiety on the surfaces of primary mesenchyme cells is to facilitate binding and sequestration of Ca+2 ions from the blastocoelic fluid before internalization and subsequent deposition into the growing CaCO3 skeleton.

Effect of fusarochromanone and T-2 toxin on articular chondrocytes in monolayer culture

The effect of fusarochromanone and T-2 toxin on DNA synthesis and radio-sulfate incorporation by rabbit articular chondrocytes was studied in monolayer culture. T-2 toxin reduced DNA more than 50% at 5 x 10(-9) M; fusarochromanone caused small but progressive decrements over a range of 5 x 10(-8) to 10(-6) M. These actions are not specific for chondrocytes. The findings lend no support to the hypothesis that fusarochromanone, at least in unmodified form, is the etiologic agent in Kashin-Beck disease.

Mseleni disease serum is not harmful to cultured chondrocytes

The origins of Mseleni disease, an acquired polyarticular degenerative joint disease, are unknown. We examined sera from 12 patients with the disease, 5 unaffected Mseleni residents, and 5 Durban residents. The effects of sera from the 12 patients with Mseleni disease on DNA or sulfated proteoglycan synthesis by cultured rabbit or human infant articular chondrocytes were no different from those of control sera. Cells derived from 2 children contained no stainable DR antigens; coculture had no impact on either of the above measures of cell function.

Angiotensin I converting enzyme inhibitors containing unnatural alpha-amino acid analogues of phenylalanine

The activity of three angiotensin I converting enzyme (ACE) inhibitors with unique related structures was assessed in vitro and in vivo. The three compounds were (S)(-)-1,2,3,4-tetrahydro-2-(3-mercapto-1-oxopropyl)-3-isoquinoline carboxylic acid (EU-4865), 1,2,3,4-tetrahydro-2-(3-mercapto-1-oxopropyl)-1- isoquinolinecarboxylic acid (EU-4881), and (S)(-)-1,2,3,4-tetrahydro-1-(3-mercapto-1-oxopropyl)-2- quinolinecarboxylic acid (EU-5031). In vitro EU-4881 was a competitive inhibitor that lacked potency (IC50 = 1980 nM) against purified ACE. The other two compounds were equipotent (IC50 = 41 nM) against purified ACE but differed in their inhibition kinetics. EU-4865 (Ki = 38 nM) was a noncompetitive inhibitor, and EU-5031 (Ki = 6.9 nM) was a competitive inhibitor. Against caveolae membrane-bound ACE EU-4881 also lacked potency (IC50 = 2852 nM). In vivo in the conscious acute aortic coarctate (AAC) rat it also lacked potency, having an ED30 (oral dose decreasing blood pressure 30 mmHg) greater than 100 mg/kg. The activity of EU-4865 and EU-5031 in the caveolae membrane-bound ACE and AAC rat reflected their different Ki values rather than their similar IC50 values. In vitro, EU-4865 and EU-5031 had IC50 values of 19 and 6.7 nM, respectively, and in vivo, they had ED30 values of 52 and 1.1 mg/kg, respectively. These results suggest that ACE has a binding requirement for a carboxy-terminus, hydrophobic amino acid that is important for in vivo activity.

The effect of sodium selenite on chondrocytes in monolayer culture

The effect of sodium selenite on DNA and sulfated proteoglycan synthesis by cultured rabbit articular and growth plate chondrocytes was studied as an in vitro model for Kashin-Beck disease. The selenium content of a defined medium (DMEM, fibroblast growth factor, insulin, and dexamethasone) was below the limit of detection by isotope dilution mass spectrometry. The chondrocytes were viable in the Se-free basal medium. Selenite over a range of 5 X 10(-9) M to 5 X 10(-7) M had no stimulatory effect on DNA or sulfated proteoglycan synthesis by either type of chondrocyte or skin fibroblasts. Proliferation of bovine endothelial cells was enhanced by 5 X 10(-7) M Se. At Se concentrations of greater than or equal to 10(-6) M, there was progressive inhibition of cell growth and radiosulfate incorporation of the connective tissue cells; bovine endothelial cells were more resistant. Twice equimolar concentrations of vitamins C and E exerted no protective effect against the cytotoxicity of higher concentrations of Se. Se supplementation also failed to stimulate growth of human infant chondrocytes. The model enabled simulation of conditions of hyposelenosis below those encountered in nature. The data provide no evidence that chondrocytes have idiosyncratic requirements for Se, and do not support the hypothesis that Se deficiency is a major etiologic factor in Kashin-Beck disease.

Induction of bone xenografts of rabbit growth plate chondrocytes in the nude mouse

Subcutaneous transplantation of growth plate chondrocytes isolated enzymatically from the proximal tibia of 6-week-old rabbits into athymic (nu/nu) mice resulted in the formation of cartilaginous nodules. Calcification of the matrix was first seen after 48 hrs, and endochondral ossification at 12 days. The mineral first occurred about hypertrophic cells. Histochemical alkaline phosphatase activity was concentrated in pericellular collars at the same location. Immunofluorescence examination with rabbit anti-mouse lymphocyte serum disclosed that the bulk of the osteoblasts was derived from the mouse. A small quantity of mouse antigen was present in the cartilage matrix at its junction with bone. It presumably diffused into the cartilaginous interface from the host, but the possibility that some chondrocytes were of murine origin has not been excluded. Five of six grafts of cells grown to confluence in monolayer culture for 10 to 14 days became ossified. The ability to induce mineralization declined in subculture. Chondrocytes killed by heating to 56 degrees did not induce calcified cartilage or bone.

Furrow irrigation of grain sorghum in a tropical environment. I. Influence of period of inundation and nitrogen fertilizer on dry matter production, grain yield and soil aeration

An experiment was conducted during the dry season in monsoonal tropical Australia to determine the influence of applied nitrogen (N) and period of inundation during furrow irrigation on the growth and yield of grain sorghum. Water was run in the furrows for 3, 6, 12 and 24 h at all irrigations, which were applied every 7-10 days throughout the season. A sprinkler irrigated crop was used to represent zero inundation. Increasing the period of inundation from 0 to 24 h at each irrigation reduced grain yield by 43.8, 49.5 and 43.2% for crops supplied with 0, 80 and 170 kg N ha-1 respectively. This yield reduction was associated with fewer grains per plant, grain weight having only a small influence on final yield. Air-filled porosity of the soil recovered more slowly as the period of inundation increased. The time taken to reach an air-filled porosity of 0.10 at the 10-20 cm depth interval was highly correlated with grain yield. The results indicate that grain yield is strongly influenced by the duration of waterlogging associated with flood irrigation. To minimize yield losses crops should be irrigated and drained rapidly to reduce the duration and severity of soil anaerobiosis.

Fate of urea nitrogen applied at planting to grain sorghum grown under sprinkler and furrow irrigation on a cracking clay soil

Uptake of nitrogen (N) fertilizer and yields of grain by sorghum on Cununurra clay in north-western Australia have been found previously to be higher under sprinkler than under furrow irrigation. The cause of this was investigated using a 15N balance technique on field microplots. Additional data on sequential changes in the distribution of mineral-N in the soil, and on volatilization of ammonia, were collected from outside the 15N microplots. The improved effectiveness of N fertilizer under sprinkler irrigation was associated with less upward movement of 15N into the top of the ridge and thus out of the rooting zone of the crop. Furrow irrigation caused 22% of the 15N applied to move into the top of the ridge, sprinkler irrigation caused only 2% of the 15N to do this. The urea appeared to move upwards during the first irrigation, and this N became unavailable to the sorghum because of soil dryness, high temperatures, and osmotic effects in the surface soil. Loss of 15N from the soil-plant system was approximately 27% under both systems of irrigation. This loss was attributed to denitrification, because there was no evidence for large losses of N by leaching or volatization of ammonia.

Furrow irrigation of grain sorghum in a tropical environment. II. Influence of period of inundation on the utilization of soil and fertilizer nitrogen by the crop

Grain sorghum was grown in plots that had been fertilized, before sowing, with either 0, 80 or 170 kg Ha-1 nitrogen (N), and furrow irrigated for periods of 0 (sprinkler irrigated control), 3, 6, 12 or 24 h. The apparent uptake of fertilizer nitrogen declined from 63 to 7% as the period of inundation increased from 0 to 24 h. Large quantities of nitrate (up to 82 kg N ha-1) remained in the surface soil layers of all furrow irrigated ridges at crop maturity, in contrast to the sprinkler irrigated ridges (up to 4 kg N ha-1). At all inundation periods a constant proportion of the applied nitrogen was moved to the ridge tops, where it was unavailable for plant uptake. The differences in the recovery of applied nitrogen between the crops given 0 (sprinkler) and 3 h irrigation was mainly attributed to the surface accumulation of nitrate in the latter. Further reduction of nitrogen uptake with longer periods of inundation are attributed to differential rates of loss of nitrogen from the soil by denitrification and leaching.

2,3-dihydro-4H-1-benzopyran-4-one O-carbamoyloximes, a series of gastric antisecretory agents

A series of 2,3-dihydro-4H-1-benzopyran-4-one O-carbamoyloximes were synthesized and evaluated for gastric antisecretory activity in a pylorus-ligated rat model. Various substituents in the 6-position did not afford any compounds more active than I.

Differences between two grain sorghum genotypes in adaptation to drought stress. III. Physiological responses

A sorghum hybrid (E-57) giving a higher yield under rain-fed systems of production was studied to examine the physiological basis of this effect. A comparison was made with another hybrid (TX-671) with similar maturity. E-57 was able to maintain stomatal opening to a lower leaf water potential than TX-671 because of its greater capacity to osmoregulate. In E-57 osmotic potential declined due to active solute accumulation, thus maintaining turgor as leaf water potential declined to - 2.0 MPa. In contrast, TX- 671 could only maintain this adjustment to - 1.4 MPa. The differences in osmoregulation were associated with maintenance of leaf area, water extraction and possibly root growth by E-57. This indicated that osmoregulation enabled photosynthesis to continue and that a significant amount of the resultant assimilate may have been diverted to root growth.

Differences between two grain sorghum genotypes in adaptation to drought stress. I. Crop growth and yield responses

A sorghum F1-hybrid, E57 , with reputed drought resistance was compared with another F1-hybrid, TX- 671, under irrigation and dryland conditions of severe rainfall insufficiency but ample soil water at depth in a deep cracking clay soil. Significant cultivar differences in grain yield occurred under rain-fed but not under irrigated conditions. Differences in yield were associated with different morphological responses to drought stress, with the variety E-57, in comparison with TX-671, having a lower level of floret abortion, the ability to maintain green leaf area longer during grain-filling and probably a higher root to shoot ratio. The implication of these results in relation to adaptation to drought stress is discussed.

Differences between two grain sorghum genotypes in adaptation to drought stress. II. Root water uptake and water use

A study of two sorghum hybrids, E-57 and TX-671, indicated that differences in grain yield under conditions of low rainfall were associated with increased extraction of soil water at depth. E-57 used less water before anthesis than did TX-671, which was more than compensated for by increased water use after anthesis. As soil water declined in a drying cycle, TX-671 tended to restrict its water use at a higher water content than E-57. The implication of these results is discussed.

Rotavirus infection in Otago: a serological study

A method for measuring rotavirus antibody in human sera has been established using enzyme-linked immunosorbent assay (ELISA). A Simian strain of rotavirus (SA11) was used as the antigen. Serum eluted from dried blood spots on good quality chromatography paper was found suitable for analysis. Paired serum samples from children with gastroenteritis have shown a brisk antibody response in association with the presence of rotavirus in the faeces. Community studies indicate that although all older children and adults tested have detectable antibodies to rotavirus, there is a significant rise in the number of individuals with high titre antibody in the child bearing age group, after which the levels diminish. This finding suggests that repeated infections occur throughout childhood and early adult life.

Isolation, identification, and synthesis of 4-amino-6,7-dimethoxy-3-quinolinol, the major metabolite of amiquinsin hydrochloride in rats and humans

The metabolism of amiquinsin hydrochloride (4-amino-6,7-dimethoxyquinoline hydrochloride monohydrate, I) was studied in rats and humans. The major metabolite isolated from human urine was identified through synthesis as 4-amino-6,7-dimethoxy-3-quinolinol hydrochloride hydrate (II). Acid hydrolysis of the major metabolite from rat urine also gave II. The structure of the rat metabolite subsequently was tentatively identified as the potassium salt of the 3-O-sulfate of II. The pharmacological and toxicological properties of I and II are discussed.

Synthesis and skeletal muscle relaxant activity of quaternary ammonium salts of dantrolene and clodanolene

A series of quaternary ammonium salts of dantrolene and clodanolene was prepared and evaluated for skeletal muscle relaxant activity. The quaternary ammonium salts exhibit greater aqueous solubility and, therefore, facilitate intravenous administration. One member of this series, although less effective orally, exhibited greater aqueous solubility than the sodium salt. When administered intravenously, it was a more potent antagonist of skeletal muscle contraction and yielded comparable therapeutic and muscle relaxant efficacy indexes.

Phenylfurans IV: spasmolytic 3-diethylamino-2,2-(dimethyl)propyl esters of 5-substituted phenyl-2-furancarboxylic acids

A series of 3-diethylamino-2,2-(dimethyl)propyl 5-substituted phenyl-2-furancarboxylates was prepared and found to be pharmacologically active in vitro as GI tract nonanticholinergic smooth muscle spasmolytic agents. One of the more active compounds in the series contained the 5-(4-nitrophenyl) group.

Synthesis of methyl 1-(3,4-dichlorobenzyl)-hexahydro-2,3-dioxo-4-pyridinecarboxylate

Methyl 1-(3,4-dichlorobenzyl)-hexahydro-2,3-dioxo-4-pyridinecarboxylate was prepared by alkylation of methyl hexahydro-2,3-dioxo-4-pyridinecarboxylate with alpha,3,4-trichlorotoluene. The compound showed significant antifungal activity when challenged by a spectrum of pathogenic yeast species in a minimum inhibitory concentration test. It was active against some dermatophytic fungi and Aspergillus niger.