Characterization of XV7 and XV9 cDNA clones which confer osmotolerance to Eschericia coli

The sequence similarity between XV7 and the mammalian syntaxin-like protein kinase receptor shows that XV7 may function similar to that of animal protein kinases. The syntaxin-like protein kinase receptor was recently entered into the Genbank (Thoreau, unpublished), therefore not much is known about its characteristics. It does show similarity to a myotonin protein kinase, MtPK (Thoreau, unpublished). The plant receptor-like protein kinases (RLKs) are structurally related to the polypeptide growth factor receptors of animals (Walker, 1994). Although several ABA and stressresponsive gene have been characterised, their physiological role in the initial perception and transduction of stress signals is not well defined Recent reports suggest that characterising phosphorylation/ dephosphorylation responses and investigation of stress-responsive protein kinases may contribute towards identifying the pivotal regulatory steps in plant responses to environmental stress

Orthopaedic device innovation in South Africa: A study of patenting activity

We assessed knowledge development and exchange among actors who patent orthopaedic devices in South Africa over the period 2000–2015. A social network analysis was performed on bibliometric data using co-inventorship on patents as an indicator of collaboration between different organisations, with a focus on the spatial and sectoral contexts. Network metrics and innovation system indices are used to describe knowledge development and exchange. The results show that university, healthcare and industry organisations have primarily been responsible for increased patenting over time. The key actors were a set of industry actors – a national actor and its US partner – who have patented many devices jointly. National universities were found to make a small contribution, and science councils were found to be absent, despite the efforts in the changing innovation landscape to encourage publicly financed research organisations to protect their intellectual property. The collaboration networks were found to be sparse and disjointed, with many actors – largely from the private healthcare sector – patenting in isolation.Significance: The considerable number of patents filed by private sector clinicians in orthopaedic device innovation in their personal capacity is highlighted. Few patents emanate from national universities, and science council actors are largely absent, despite the Intellectual Property Rights from Publicly Financed Research and Development Act to protect intellectual property emanating from public research organisations. Patenting networks are more fragmented than are scientific publication networks

Symptomatic HIV infection in infancy - clinical and laboratory markers of infection

Objective. To investigate the usefulness of immunological tests in the diagnosis of HIV infection in young symptomatic children < 15 months of age).Design. Tests were evaluated in HIV-infected (HIV antibody- and PCR-positive) patients and non-infected individuals.Setting. Hospitalised patients in a referral centre (Red Cross War Memorial Children's Hospital, Cape Town). Patients. All admissions under 15 months of age who had HIV antibody requested were eligible, provided there was sufficient serum (150 1-11) for further study. Overall, there were 201 symptomatic cases and 49 healthy controls. Twenty of the symptomatic cases were HIV antibody-positive and 19 of these were HIV-infected on the basis of a positive PCR for HIV viral productResults. Of the tests we evaluated (total IgG, IgM, IgA and rheumatoid factors of the same classes), raised total IgG level (cut-off 18 g/I or above) was the most useful. We used a commercial radial immunodiffusion plate which was found to have excellent reproducibility (inter-assay coefficient of variation 3.2%). The test detected 16 of 19 infected infants (sensitivity 84%, negative predictive value 98%). With the exception of the finding of oral thrush (odds ratio 7; P < 0.001), the clinical signs at presentation did not distinguish those who were HIV antibody-positive from those who were negative.Conclusions. In our study of hospital admissions, the finding of elevated IgG and HIV antibody was diagnostic of HIV infection. (The positive predictive value of the combination was 100%.) Likewise, the presence of raised IgG levels and oral candidosis had a high specificity for HIV infection (98%) but the sensitivity was low (37%).Measurement of total IgG levels by radial immunodiffusion is simple, relatively inexpensive < 10% of the cost of PGR), helpful in diagnosing HIV infection in symptomatic infants and able to be performed in areas with minimal laboratory back-up

Innovation in sport medicine and science: a global social network analysis of stakeholder collaboration in rugby union

Objectives To investigate the network of stakeholders involved in rugby union research across the globe. Methods Using author affiliations listed on scientific publications, we identified the organisations that contributed to rugby union research from 1977 to 2022 and examine collaboration through coauthorship indicators. We determined the locations and sectors of identified organisations and constructed a collaboration network. Network metrics, including degree centrality and betweenness centrality, are computed to identify influential organisations and measure intersector collaboration. Results There is an increase in scientific knowledge creation and collaboration between organisations for rugby union research over time. Among the sectors, the university, professional sports team and sports governing body sectors exhibit the highest intersectoral and intrasectoral density. Predominantly, influential actors are located in England, Australia, France, New Zealand, Ireland and South Africa. Australian Catholic University, Leeds Beckett University, Stellenbosch University, Swansea University, University College London and the University of Cape Town emerge as influential actors between 2016 and 2022. Conclusions Our study underscores the ongoing growth of scientific knowledge generation in rugby union, primarily led by organisations in tier 1 rugby-playing nations within the university sector. Intersectoral collaboration with sports governing bodies plays a crucial role, acting as a broker between sectors. However, the overall collaboration landscape between and within sectors is low. These results highlight an opportunity for improved collaboration opportunities, as the organisations driving knowledge creation have been identified

Characteristics course and outcomes of children admitted to a paediatric intensive care unit after cardiac arrest

Background. Cardiac arrest is a potentially devastating event, associated with death or severe neurological complications in survivors. There is little evidence on paediatric cardiac arrest prevalence, characteristics and outcomes in South Africa (SA). Objective. To describe the characteristics, course and outcomes of children admitted to an SA paediatric intensive care unit (PICU) following cardiac arrest. Methods. Retrospective descriptive study of routinely collected data (January 2010 - December 2011). Results. Of 2 501 PICU admissions, 110 (4.4%) had preceding cardiac arrest. The median (interquartile range (IQR)) age of children was 7.2 (2.5 - 21.6) months. In-hospital arrests accounted for 80.6% of the events. The most common primary diagnostic categories were respiratory (29.1%), cardiovascular (21.4%) and gastrointestinal (21.4%). Twenty-four patients (23.3%) arrested during endotracheal intubation. Cardiopulmonary resuscitation (CPR) was applied for a median (IQR) of 10 (5 - 20) minutes. Duration of CPR for non-survivors and survivors was 17.5 (10 - 30) v. 10 (5 - 15) minutes (p=0.006). PICU mortality was 38.8%, with half of the deaths occurring within 24 hours of admission. The standardised mortality ratio was 0.7. The median (IQR) length of stay in the PICU and hospital was 3 (1 - 8) and 27 (9 -52) days, respectively. No independent predictors of mortality were identified. Thirty-nine surviving patients (76.5%) had normal neurological function or mild disability at follow-up after hospital discharge. Six (11.8%) survived with severe disability. Conclusion. Mortality was lower than predicted in children admitted to the PICU following cardiac arrest. The majority of survivors had good neurological outcomes

Ventilator-associated pneumonia in PICU – how are we doing?

Introduction. Ventilator-associated pneumonia (VAP) is a common hospital-acquired infection in children, leading to an increase in morbidity and mortality. A previous study in 2013 showed that VAP rates decreased dramatically after implementation of a VAP bundle and appointing a VAP coordinator. As part of a ‘Plan, Do, Study, Act’ cycle, it was necessary to evaluate the efficacy of these interventions. Objective. To evaluate the VAP rate in the paediatric intensive care unit (PICU) over 2 years (2017 - 2018), and to describe the causative organisms and antibiotic sensitivity/resistance patterns during this period. Methods. This was a retrospective, descriptive study using the existing PICU VAP database as well as clinical folders. Results. Over the 2 years, 31 VAP cases were identified. The VAP rate for 2017 was 4.0/1 000 ventilator days and 5.4/1 000 ventilator days for 2018. Compliance with the VAP bundle was 68% in 2017 and 70% in 2018. The median (interquartile range (IQR)) duration of ventilation in 2017 was 9 (6 -12) days and 15 (11 - 28) days in 2018. The median (IQR) length of PICU stay in 2017 was 11 (8 - 22) days and 25 (17 - 37) days in 2018. The most common cultured organism was an extended-spectrum beta-lactamase (ESBL) Klebsiella pneumoniae sensitive to amikacin and carbapenems. Conclusion. Our VAP rate has not decreased since 2013. It is imperative that we improve compliance with the VAP bundle, in order to reduce VAP rates. K. pneumoniae and Pseudomonas aeruginosa were the most common organisms causing VAPs and empiric use of piptazobactam and amikacin is still appropriate

Revival of the magnetar PSR J1622-4950: observations with MeerKAT, Parkes, XMM-Newton, Swift, Chandra, and NuSTAR

New radio (MeerKAT and Parkes) and X-ray (XMM-Newton, Swift, Chandra, and NuSTAR) observations of PSR J1622-4950 indicate that the magnetar, in a quiescent state since at least early 2015, reactivated between 2017 March 19 and April 5. The radio flux density, while variable, is approximately 100x larger than during its dormant state. The X-ray flux one month after reactivation was at least 800x larger than during quiescence, and has been decaying exponentially on a 111+/-19 day timescale. This high-flux state, together with a radio-derived rotational ephemeris, enabled for the first time the detection of X-ray pulsations for this magnetar. At 5%, the 0.3-6 keV pulsed fraction is comparable to the smallest observed for magnetars. The overall pulsar geometry inferred from polarized radio emission appears to be broadly consistent with that determined 6-8 years earlier. However, rotating vector model fits suggest that we are now seeing radio emission from a different location in the magnetosphere than previously. This indicates a novel way in which radio emission from magnetars can differ from that of ordinary pulsars. The torque on the neutron star is varying rapidly and unsteadily, as is common for magnetars following outburst, having changed by a factor of 7 within six months of reactivation.Comment: Published in ApJ (2018 April 5); 13 pages, 4 figure

Antibacterial and dermal toxicological profiles of ethyl acetate extract from Crassocephalum bauchiense (Hutch.) Milne-Redh (Asteraceae)

<p>Abstract</p> <p>Background</p> <p>The emergence in recent years of numerous resistant strains of pathogenic bacteria to a range of formerly efficient antibiotics constitutes a serious threat to public health. <it>Crassocephalum bauchiense</it>, a medicinal herb found in the West Region of Cameroon is used to treat gastrointestinal infections as well as liver disorders. The ethyl acetate extract from the leaves of <it>C. bauchiense </it>was evaluated for its antibacterial activity as well as acute and sub-acute toxicities.</p> <p>Methods</p> <p>The plant extract was prepared by maceration in ethyl acetate. Its phytochemical screening was done by standard methods. The broth microdilution method was used to evaluate the <it>in vitro </it>antibacterial activity. The <it>in vivo </it>antibacterial activity of a gel formulation (0.05, 1 and 2% w/v) of this extract was evaluated using a <it>Staphylococcus aureus</it>-induced dermatitis in a murine model. Selected haematological and biochemical parameters were used to evaluate the dermal sub-acute toxicity of the extract in rats.</p> <p>Results</p> <p>Phytochemical screening of the <it>C. bauchiense </it>extract revealed the presence of alkaloids, phenols, tannins and sterols. <it>In vitro </it>antibacterial activities were observed against all the tested microorganisms (MIC = 0.04-6.25 mg/ml). Formulated extract-gel (2% w/v) and gentamycin (reference drug) eradicated the microbial infection after five days of treatment. A single dermal dose of this extract up to 32 g/kg body weight (bw) did not produce any visible sign of toxicity. Also, daily dermal application of the <it>C. bauchiense </it>extract gel formulation for 28 days did not show any negative effect, instead some biochemical parameters such as alanine aminotransferase (ALT and AST), low density lipoprotein (LDL), high density lipoprotein (HDL) and triglycerides were significantly (p < 0.05) affected positively.</p> <p>Conclusion</p> <p>These results indicate that the <it>C. bauchiense </it>ethyl acetate extract can be used safely for the treatment of some bacterial infections.</p

Physiological Notch Signaling Maintains Bone Homeostasis via RBPjk and Hey Upstream of NFATc1

Notch signaling between neighboring cells controls many cell fate decisions in metazoans both during embryogenesis and in postnatal life. Previously, we uncovered a critical role for physiological Notch signaling in suppressing osteoblast differentiation in vivo. However, the contribution of individual Notch receptors and the downstream signaling mechanism have not been elucidated. Here we report that removal of Notch2, but not Notch1, from the embryonic limb mesenchyme markedly increased trabecular bone mass in adolescent mice. Deletion of the transcription factor RBPjk, a mediator of all canonical Notch signaling, in the mesenchymal progenitors but not the more mature osteoblast-lineage cells, caused a dramatic high-bone-mass phenotype characterized by increased osteoblast numbers, diminished bone marrow mesenchymal progenitor pool, and rapid age-dependent bone loss. Moreover, mice deficient in Hey1 and HeyL, two target genes of Notch-RBPjk signaling, exhibited high bone mass. Interestingly, Hey1 bound to and suppressed the NFATc1 promoter, and RBPjk deletion increased NFATc1 expression in bone. Finally, pharmacological inhibition of NFAT alleviated the high-bone-mass phenotype caused by RBPjk deletion. Thus, Notch-RBPjk signaling functions in part through Hey1-mediated inhibition of NFATc1 to suppress osteoblastogenesis, contributing to bone homeostasis in vivo

Growth hormone secretion is correlated with neuromuscular innervation rather than motor neuron number in early-symptomatic male amyotrophic lateral sclerosis mice

GH deficiency is thought to be involved in the pathogenesis of amyotrophic lateral sclerosis (ALS). However, therapy with GH and/or IGF-I has not shown benefit. To gain a better understanding of the role of GH secretion in ALS pathogenesis, we assessed endogenous GH secretion in wild-type and hSOD1(G93A) mice throughout the course of ALS disease. Male wild-type and hSOD1(G93A) mice were studied at the presymptomatic, onset, and end stages of disease. To assess the pathological features of disease, we measured motor neuron number and neuromuscular innervation. We report that GH secretion profile varies at different stages of disease progression in hSOD1(G93A) mice; compared with age-matched controls, GH secretion is unchanged prior to the onset of disease symptoms, elevated at the onset of disease symptoms, and reduced at the end stage of disease. In hSOD1(G93A) mice at the onset of disease, GH secretion is positively correlated with the percentage of neuromuscular innervation but not with motor neuron number. Moreover, this occurs in parallel with an elevation in the expression of muscle IGF-I relative to controls. Our data imply that increased GH secretion at symptom onset may be an endogenous endocrine response to increase the local production of muscle IGF-I to stimulate reinnervation of muscle, but that in the latter stages of disease this response no longer occurs