Inhomogeneous Kondo-lattice in geometrically frustrated Pr2Ir2O7

Magnetic fluctuations induced by geometric frustration of local Ir-spins disturb the formation of long-range magnetic order in the family of pyrochlore iridates. As a consequence, Pr₂Ir₂O₇ lies at a tuning-free antiferromagnetic-to-paramagnetic quantum critical point and exhibits an array of complex phenomena including the Kondo effect, biquadratic band structure, and metallic spin liquid. Using spectroscopic imaging with the scanning tunneling microscope, complemented with machine learning, density functional theory and theoretical modeling, we probe the local electronic states in Pr₂Ir₂O₇ and find an electronic phase separation. Nanoscale regions with a well-defined Kondo resonance are interweaved with a non-magnetic metallic phase with Kondo-destruction. These spatial nanoscale patterns display a fractal geometry with power-law behavior extended over two decades, consistent with being in proximity to a critical point. Our discovery reveals a nanoscale tuning route, viz. using a spatial variation of the electronic potential as a means of adjusting the balance between Kondo entanglement and geometric frustration.

Pyrochlore iridates lie at a tuning-free magnetic quantum critical point hosting several complex exotic phenomena. Here, the authors discover an electronic phase separation in single crystalline Pr₂Ir₂O₇, where well-defined Kondo resonances are interweaved with a non-magnetic metallic phase with Kondo-destruction.

A text message intervention to support women's physical and mental health after breast cancer treatments (EMPOWER-SMS): a randomised controlled trial protocol

Background

Breast cancer is the most common cancer diagnosed in women worldwide. In developed countries, 80–90% of women will survive five years after diagnosis but the transition from hospital-based care to health self-management and self-efficacy can be difficult. Text messaging programs offer a simple and proven way to provide support to people with chronic diseases. This study aims to test the effectiveness of a text message support program at improving women’s health self-efficacy, and physical and mental health outcomes after breast cancer treatments compared to usual care at 6-months and to understand the barriers and enablers to widespread implementation.

Methods

Single-blind randomised control trial (RCT; N = 160) comparing a text message support intervention to usual care in women with breast cancer (recruited from a large tertiary referral hospital in Sydney, Australia). The intervention group will receive a six-month text message support program, which consists of semi-personalised, supportive, lifestyle-focused text messages (4 messages/week) in addition to usual care. The control group will receive usual care without the text message program. Outcomes will be assessed at 6-months. The primary outcome is change in self-efficacy for managing chronic disease. Secondary outcomes include change in clinical outcomes (body mass index), lifestyle outcomes (physical activity levels, dietary behaviours), mood (depression and anxiety scales), quality of life, satisfaction with, and usefulness of the intervention. Analyses will be performed on the principle of intention-to-treat to examine differences between intervention and control groups.

Discussion

This study will test if a scalable and cost-effective text-messaging intervention is effective at improving women’s health self-efficacy, as well as physical and mental health outcomes. Moreover, this study will provide essential preliminary data to bolster a large multicentre RCT to helpsupport breast cancer survivors throughout recovery and beyond.

Trial registration

Australia New Zealand Clinical Trials Registry (ANZCTR) number ACTRN12618002020268, 17 December 2018

The Listeria monocytogenes PASTA Kinase PrkA and Its Substrate YvcK Are Required for Cell Wall Homeostasis, Metabolism, and Virulence

Obstacles to bacterial survival and replication in the cytosol of host cells, and the mechanisms used by bacterial pathogens to adapt to this niche are not well understood. Listeria monocytogenes is a well-studied Gram-positive foodborne pathogen that has evolved to invade and replicate within the host cell cytosol; yet the mechanisms by which it senses and responds to stress to survive in the cytosol are largely unknown. To assess the role of the L. monocytogenespenicillin-binding-protein and serine/threonine associated (PASTA) kinase PrkA in stress responses, cytosolic survival and virulence, we constructed a ΔprkA deletion mutant. PrkA was required for resistance to cell wall stress, growth on cytosolic carbon sources, intracellular replication, cytosolic survival, inflammasome avoidance and ultimately virulence in a murine model of Listeriosis. In Bacillus subtilis and Mycobacterium tuberculosis, homologues of PrkA phosphorylate a highly conserved protein of unknown function, YvcK. We found that, similar to PrkA, YvcK is also required for cell wall stress responses, metabolism of glycerol, cytosolic survival, inflammasome avoidance and virulence. We further demonstrate that similar to other organisms, YvcK is directly phosphorylated by PrkA, although the specific site(s) of phosphorylation are not highly conserved. Finally, analysis of phosphoablative and phosphomimetic mutants of YvcK in vitro and in vivo demonstrate that while phosphorylation of YvcK is irrelevant to metabolism and cell wall stress responses, surprisingly, a phosphomimetic, nonreversible negative charge of YvcK is detrimental to cytosolic survival and virulence in vivo. Taken together our data identify two novel virulence factors essential for cytosolic survival and virulence of L. monocytogenes. Furthermore, our data demonstrate that regulation of YvcK phosphorylation is tightly controlled and is critical for virulence. Finally, our data suggest that yet to be identified substrates of PrkA are essential for cytosolic survival and virulence of L. monocytogenes and illustrate the importance of studying protein phosphorylation in the context of infection.

Infection with intracellular pathogens causes a majority of the global infectious disease associated mortality. A number of intracellular pathogens must directly access the host cytosol in order to cause disease; however, non-cytosol adapted bacteria do not survive or replicate upon access to the cytosol. The mechanisms cytosolic pathogens use to adapt to this niche are largely unknown. The model cytosolic bacterial pathogen Listeria monocytogenes contains a single penicillin-binding-protein and serine/threonine associated (PASTA) kinase, PrkA. In other bacteria, PASTA kinases bind cell wall fragments and phosphorylate downstream effectors involved in cell wall synthesis, central metabolism, virulence, cell division, and biofilm formation. We demonstrate that in L. monocytogenes, PrkA is required for cell wall homeostasis, growth under nutrient limiting conditions, survival and replication in host cells, and virulence in vivo. Furthermore, we identify a highly conserved protein of unknown function, YvcK, as a PrkA substrate. We demonstrate that L. monocytogenes YvcK is similarly required for cell wall stress responses, growth on glycerol, cytosolic survival and virulence in vivo. Surprisingly, a phosphomimetic, nonreversible negative charge at the phosphorylation sites on YvcK inactivates functions of the protein related to intracellular survival and virulence, suggesting that the identification of PASTA kinase substrates phosphorylated during infection will be critical to our understanding of this central regulator metabolism, cell wall homeostasis and ultimately virulence.

Smart tool for force measurements during knee arthroscopy: in vivo human study

This paper describes the magnitude and patterns of forces obtained by using a probe, equipped with a six-axis force torque sensor, in knee arthroscopy. The probe was used by orthopaedic surgeons and trainees, who performed 11 different tasks in 10 standard knee arthroscopies. The force magnitude and patterns generated are presented; which can support the development of virtual arthroscopy systems with realistic haptic feedback. The results were compared across both groups of surgeons. A difference in the force patterns generated by senior versus junior surgeons was noted which can aid in the development of an objective assessment system for arthroscopy skills. The results could potentially be useful to assess future performance in real arthroscopy.

Computer assisted orthopaedic surgical system for insertion of distal locking screws in intra-medullary nails: a valid and reliable navigation system

The insertion of distal locking screws is a difficult task in intra-medullary (IM) nailing operations of long bones and contributes a significant proportion to the overall operating time. The current technique to insert these screws uses numerous fluoroscopic images and depends on the skills and expertise of the surgeon. The Computer Assisted Orthopaedic Surgical System (CAOSS) was developed to assist orthopaedic surgeons in these operations. The laboratory based test results for insertion of distal locking screws in IM nailing procedures are presented and discussed in terms of accuracy and as part of the validation process to introduce new CAOS procedures into clinical use. This study shows that CAOSS in IM nailing is robust and reliable. Positional accuracy was shown to be within 0.3 mm and angular accuracy within 0.2 degrees with femoral IM nail. CAOSS was also shown to be very reliable and accurate at different angles of distal screws in fluoroscopic image space.

Maintenance therapy with a probiotic in antibiotic-dependent pouchitis: experience in clinical practice

BACKGROUND

Management of antibiotic-dependent pouchitis is often challenging. Oral bacteriotherapy with probiotics (such as VSL #3) as maintenance treatment has been shown to be effective in relapsing pouchitis in European trials. However, this agent has not been studied in the US, and its applicability in routine clinical practice has not been evaluated.

AIM

To determine compliance and efficacy of probiotic treatment in patients with antibiotic-dependent pouchitis.

METHODS

Thirty-one patients with antibiotic-dependent pouchitis were studied. VSL #3 is a patented probiotic preparation of live freeze-dried bacteria. All patients received 2 weeks of ciprofloxacin 500 mg b.d. followed by VSL #3 6 g/day for 8 months. Baseline Pouchitis Disease Activity Index scores were calculated. Patients' symptoms were reassessed at week 3 when VSL #3 therapy was initiated and at the end of the 8-month trial. Some patients underwent repeat pouch endoscopy at the end of the trial.

RESULTS

All 31 patients responded to the 2-week ciprofloxacin trial with resolution of symptoms and they were subsequently treated with VSL #3. The mean duration of follow-up was 14.5+/-5.3 months (range: 8-26 months). At the 8-month follow-up, six patients were still on VSL #3 therapy, and the remaining 25 patients had discontinued the therapy due to either recurrence of symptoms while on treatment or development of adverse effects. All six patients who completed the 8-month course with a mean treatment period of 14.3+/-7.2 months (range: 8-26 months) had repeat clinical and endoscopic evaluation as out-patients. At the end of 8 months, these six patients had a mean Pouchitis Disease Activity Index symptom score of 0.33+/-0.52 and a mean Pouchitis Disease Activity Index endoscopy score of 1.83+/-1.72, which was not statistically different from the baseline Pouchitis Disease Activity Index endoscopy score of 2.83+/-1.17 (P=0.27).

CONCLUSION

This study was conducted to evaluate bacteriotherapy in routine care. The use of probiotics has been adopted as part of our routine clinical practice with only anecdotal evidence of efficacy. Our review of patient outcome from the treatment placebo showed that only a minority of patients with antibiotic-dependent pouchitis remained on the probiotic therapy and in symptomatic remission after 8 months.

Antiapoptotic role of the p38 mitogen-activated protein kinase-myocyte enhancer factor 2 transcription factor pathway during neuronal differentiation

Myocyte enhancer factor 2 (MEF2) is in the MADS (MCM1agamous-deficiens-serum response factor) family of transcription factors. Although MEF2 is known as a myogenic factor, the expression pattern of the MEF2 family of genes (MEF2A-D) in developing brain also suggests a role in neurogenesis. Here we show that transfection with MEF2C, the predominant form in mammalian cerebral cortex, induces a mixed neuronal/myogenic phenotype in undifferentiated P19 precursor cells. During retinoic acid-induced neurogenesis of these cells, a dominant negative form of MEF2 enhances apoptosis but does not affect cell division. The mitogen-activated protein kinase p38alpha activates MEF2C. Dominant negative p38alpha also enhances apoptotic death of differentiating neurons, but these cells can be rescued from apoptosis by coexpression of constitutively active MEF2C. These findings suggest that the p38alpha/MEF2 pathway prevents cell death during neuronal differentiation.

Absence of binding activity of neuron-restrictive silencer factor is necessary, but not sufficient for transcription of NMDA receptor subunit type 1 in neuronal cells

Neuron-restrictive silencer factor (NRSF, also termed REST) has been proposed to restrict expression of a set of genes to neurons by blocking their transcription in nonneuronal cells. The N-methyl-D-aspartate (NMDA) receptor subunit type I (NR1) gene contains a consensus sequence for the NRSF/REST binding site (NRSE/RE1). In this study, we evaluated the contribution of NRSF/REST to neuronal specificity of the NR1 gene. NR1 mRNA expression correlates with the absence of NRSF/REST binding activity, rather than expression of NRSF/REST protein, in several cell lines, suggesting that the absence of NRSF/REST-binding activity is necessary for the expression of the NR1 gene. HeLa cells, which do not express the NR1 gene, have NRSF/REST binding activity to the NR1 NRSE/RE1, resulting in inhibition of NR1 promoter activity. However, we also found that two nonneuronal cell lines (C6 glioma and P19 embryonal carcinoma) that lack NRSF/REST-binding activity, manifest only small amounts of NR1 mRNA compared to neuronal cell lines (PC12 pheochromocytoma and neuronally differentiated P19 cells). The enhancement of NR1 mRNA levels during neuronal differentiation of P19 cells is accompanied by an increase in NR1 promoter activity in an NRSF/REST-binding independent manner. Our results suggest therefore that the absence of NRSF/REST-binding activity is necessary but not sufficient for robust NR1 transcription in neuronal cells.

Zhong Yi acupuncture and low-back pain: traditional Chinese medical acupuncture differential diagnoses and treatments for chronic lumbar pain

Little attention has been given to selecting treatments in clinical trials of acupuncture. Yet in order to perform objective tests of this procedure, it is crucial that the selected treatments are considered representative of the style of practice being tested. We examined 16 traditional Chinese medicine (TCM) acupuncture texts or treatment articles to determine the consistency of diagnosis and recommended treatment for chronic low-back pain. Although 24 diagnostic patterns were described by 1 or more texts, only 4 patterns were described by at least half of the texts. Most texts (12/16) described only 3 or 4 patterns. These could be categorized into 3 broad types: cold, damp, wind, heat channel obstruction patterns; kidney vacuity patterns (sometimes differentiated into yang and yin patterns); and blood (or blood and qi) stasis patterns. Several acupuncture points were recommended by most texts regardless of the diagnosis, whereas other acupoints were recommended for specific diagnostic patterns. There was, however, substantial variation between texts in recommended acupoints, with less than 20% of all acupoints recommended by half or more of the texts. This varibility will make it difficult to select TCM treatments for clinical trials of chronic low-back pain that have wide applicability. We believe that examining treatment patterns in actual clinical practice is crucial in this situation. We suggest that this method of selecting treatments should be part of the process used when selecting treatments for all clinical trials of acupuncture, regardless of the style of practice.

Structure-function analysis of the trypanosomatid spliced leader RNA

In trypanosomes, all mRNAs possess a spliced leader (SL) at their 5' end. SL is added to pre-mRNA via trans -splicing from a small RNA, the SL RNA. To examine structure-function aspects of the trypanosomatid SL RNA, an in vivo system was developed in the monogenetic trypanosomatid Leptomonas collosoma to analyze the function of chimeric and site-directed SL RNA mutants in trans -splicing. Stable cell lines expressing chimeric and mutated SL RNA from the authentic SL RNA regulatory unit were obtained. The chimeric RNA was expressed and assembled into an SL RNP particle, but could not serve as a substrate in splicing. Mutations in loop II and III of L.collosoma SL RNA formed the Y structure intermediate. In addition, a double SL RNA mutant in loop II, and positions 7 and 8 of the intron, also formed the Y structure intermediate, suggesting that these intron positions, although proposed to participate in the interaction of SL RNA with U5, may not be crucial for the first step of the trans -splicing reaction. A mutation in the exon located in loop I was not utilized in splicing, suggesting the importance of exon sequences for trans -splicing in trypanosomes. However, a double SL RNA mutant in loop II and exon position 31 was utilized in both steps of splicing; the mutant thus provides a model molecule for further analysis of positions essential for the function of the SL RNA.

Recruiting nurses based on competencies needed in the restructured environment

Although the market seems to be flooded with them, you may very well be facing a shortage of nurses. It has never been more critical to the survival of your organization to have the "right" nurses in place. By using a careful and intentional process of defining successful characteristics while your new care model is being designed, you should be able to avoid the pitfalls of recruiting during a period of urgent need. To hire the right nurses to support the restructured environment, you need to avoid the approach of hiring "all-at-once" just to fill vacancies.

Evidence for a global scanpath strategy in viewing abstract compared with realistic images

Scanpaths, the repetitive sequences of saccadic eye movements, occurred when subjects viewed slide projections of both realistic and abstract art. Variance analysis demonstrated that global/local eye movement indices were lower for local scanning by professional art viewers who relied on more global viewing, particularly in abstract images. Non-professional, unsophisticated subjects carried their local scanpath patterns from realistic images on to abstract images. The blink rate of professional subjects viewing abstract images was also significantly lower, indicating increased visual effort. Non-professional viewers showed no difference in blink rates.

Characterization of prediction in the primate visual smooth pursuit system

To define predictive behavior and mechanisms in visual smooth pursuit, various target motions were presented to 2 monkeys. Target stimuli included: single sinusoids (1's), triangle waves (T's), sums of 4 nonharmonically related sinusoids (4's), bandpass limited white noise (B's), and wideband white noise (N's). Velocity error was least for 1's, greatest for N's, and intermediate for T's, 4's, and B's. For the bandlimited 4's and B's, monkeys demonstrated the greatest relative amplitude response at the highest frequencies. Predictive mechanisms are classified as short- and long-term, depending on how much past target motion information is employed. The T's and a modification of this stimulus pattern involving a random perturbation were used to test the hypothesis that prediction is based exclusively on short-term signal processing related to target position and its derivatives. The existence of long-term predictive mechanisms in monkey smooth pursuit was unequivocally demonstrated with the use of the latter stimulus.

Potential pharmacotherapy of Alzheimer disease. A comparison of various forms of physostigmine administration

This paper reviews clinical trials with physostigmine administered to Alzheimer patients using three different routes of administration: oral, i.v. and intracerebroventricular (i.c.v.). It compares results obtained with three different routes by the authors as well as by other authors. Particular emphasis is given to a novel type of physostigmine administration, the i.c.v. route. Advantages and disadvantages, as well as side effects of each route are presented and discussed.

Congenital chylothorax: report of unique case associated with 'H' -type tracheo-oesophageal fistula

A case of congenital chylothorax associated with a congenital 'H'-type tracheo-oesophageal fistula is reported. The development of the thoracic duct is described and the possible embryological association with tracheo-oesophageal fistula is discussed. The management of the case is reviewed.

Proposed mechanisms of propranolol's antihypertensive effect in essential hypertension

We studied the antihypertensive effect of propranolol alone and in combination with diuretics in 13 patients with high, 18 with normal and nine with low-renin essential hypertension whose blood-pressure response to diuretics was previously established. Propranolol (160 mg daily) significantly lowered mean arterial pressure in high-renin (129 +/- 2.6 to 114 +/- 2.1 mm Hg) and normal-renin (131 +/- 2.7 to 119 +/- 3.5 mm Hg) patients but not in low-renin patients. A positive correlation (r = 0.36, P less than 0.05) between fall in pressure and fall in plasma renin activity occurred at this dose when the whole group was considered. An antihypertensive effect occurred in both high-renin and low-renin hypertension during large-dose (320 to 960 mg daily) propranolol therapy. This effect was independent of changes in plasma renin activity. The antihypertensive effects of propranolol and diuretics were additive in normal-renin and high-renin hypertension. These data suggest that propranolol's pressure-lowering activity is due to both renin-dependent and renin-independent effects.