Tying up loose ends: a method for constructing and evaluating decision aids that meet blunt and sharp-end goals

We present a methodological framework for constructing and evaluating decision aids--fast and frugal trees (FFTs)--ideally suited to the front line of an organisation. Their performance can be analysed in signal detection theory, allowing for transparent selection of FFTs given managerial-level trade-offs among type I and II errors. We extend FFTs from binary classification to selection from multiple actions (FFT multiple) as well as performance analysis to organisational goal states beyond type I and II error reduction. Concepts and framework are introduced and a tutorial-style example application (threat assessment at military checkpoints) is provided. Throughout, we discuss ways to deal with missing or incomplete data and show that the performance of decision aids may be overestimated if the effectiveness of actions is not heeded. The methodology can be used to construct and evaluate decision aids in any area characterised by dichotomised cues and a one-to-many mapping between categorisation outcomes and actions.

Caspase-8 as a regulator of tumor cell motility

The caspases are a family of ubiquitously expressed cysteine proteases best known for their roles in programmed cell death. However, caspases play a number of other roles in vertebrates. In the case of caspase-8, loss of expression is an embryonic lethal phenotype, and caspase-8 plays roles in suppressing cellular necrosis, promoting differentiation and immune signaling, regulating autophagy, and promoting cellular migration. Apoptosis and migration require localization of caspase-8 in the periphery of the cells, where caspase-8 acts as part of distinct biosensory complexes that either promote migration in appropriate cellular microenvironments, or cell death in inappropriate settings. In the cellular periphery, caspase-8 interacts with components of the focal adhesion complex in a tyrosine-kinase dependent manner, promoting both cell migration in vitro and metastasis in vivo. Mechanistically, caspase-8 interacts with components of both focal adhesions and early endosomes, enhancing focal adhesion turnover and promoting rapid integrin recycling to the cell surface. Clinically, this suggests that the expression of caspase-8 may not always be a positive prognostic sign, and that the role of caspase-8 in cancer progression is likely context-dependent.

Direct evidence of Fe(2+)-Fe3+ charge ordering in the ferrimagnetic hematite-ilmenite Fe(1.35)Ti(0.65)O(3-δ) thin films

In this Letter we highlight direct experimental evidence of Fe(2+)-Fe3+ charge ordering at room temperature in hematite-ilmenite Fe(1.35)Ti(0.65)O(3-δ) epitaxial thin films grown by pulsed laser deposition, using aberration-corrected scanning transmission electron microscopy coupled to high-resolution energy electron-loss spectroscopy. These advanced spectromicroscopy techniques demonstrate a strong modulation of the Fe2+ valence state along the c axis. Density functional theory calculations provide crucial information on the key role of oxygen vacancies in the observed charge distributions. Their presence at significant levels leads to the localization of extra electrons onto reduced Fe2+ sites, while Ti remains solely +4. The magnetic and transport properties of these films are reviewed in the light of the present results regarding their ferrimagnetic character correlated with the Fe2+ modulation and their semiconducting behavior interpreted by an Efros-Shklovskii variable-range hopping conduction regime via Fe2+ and Fe3+ centers. The experimental evidence of only one type of mixed valence state, i.e., Fe2+ and Fe3+, in the Fe(2-x)Ti(x)O(3-δ) system will thus help to interpret further the origin of its geomagnetic properties and to illuminate fundamental issues regarding its spintronic potential.

Src-inducible association of CrkL with procaspase-8 promotes cell migration

Procaspase-8, the zymogen form of the apoptosis-initiator caspase-8, undergoes phosphorylation following integrin-mediated cell attachment to an extracellular matrix substrate. Concordant with cell attachment to fibronectin, a population of procaspase-8 becomes associated with a peripheral insoluble compartment that includes focal complexes and lamellar microfilaments. Phosphorylation of procaspase-8 both impairs its maturation to the proapoptotic form and can promote cell migration. Here we show that the cytoskeletal adaptor protein CrkL promotes caspase-8 recruitment to the peripheral spreading edge of cells, and that the catalytic domain of caspase-8 directly interacts with the SH2 domain of CrkL. We show that the interaction is abolished by shRNA-mediated silencing of Src, in Src-deficient MEFs, and by pharmacologic inhibitors of the kinase. The results provide insight into how tyrosine kinases may act to coordinate the suppression caspase-8 mediated apoptosis, while promoting cell invasion.

Dynamics of childhood invasive meningococcal disease in Israel during a 22-year period (1989-2010)

AIM

To describe the dynamics in the incidence of childhood invasive meningococcal disease (IMD) in Israel during a 22-year period (1989-2010).

METHODS

A longitudinal prospective surveillance in all 27 medical centers with pediatric services in Israel. All cases of children <15 years old with positive blood/cerebrospinal fluid (CSF) culture for Neisseria meningitidis were reported. Demographic, clinical, and bacteriological data were recorded. Meningococcal vaccine was not routinely given to Israeli children during the study period.

RESULTS

The mean age ± standard deviation (SD) among the 743 cases was 40.7 ± 40.2 months. The mean yearly incidence/100,000 was 2.0 ± 0.8. Age-specific incidences were 8.7 ± 2.8, 2.9 ± 1.5, and 0.8 ± 0.5 for children <1, 1-4, and >4 years old, respectively. The overall incidence decreased significantly from 3.7 in 1989 to 1.5 in 2010. Meningitis constituted 69.2 % of all cases. The most common serogroups were: B (76.9 %), C (10.9 %), Y (8.0 %), and W(135) (2.9 %). 78.6 % of all serogroup B isolates were from children <5 years old (p < 0.01). Serogroup C was found mainly in children ≥5 years old (63.4 %). The case fatality rates (CFRs) for children <1, 1-4, >4 years old, and the total study population were 9.2, 12.3, 7.7, and 9.9 %, respectively. CFRs were higher for children without meningitis (14.9 %) compared to children with meningitis (7.9 %) (p < 0.01).

CONCLUSIONS

Overall, and for serogroups B and W135, childhood IMD rates decreased significantly in Israel during the study period, without routine vaccine usage. The most common serogroup in all age groups was B, which was most prevalent in children <5 years old. No change in the trend of the overall CFR was noted during the study period.

Outcome of carbapenem resistant Klebsiella pneumoniae bloodstream infections

The aim of this study was to evaluate the impact of carbapenem-resistant K. pneumoniae bloodstream infections on mortality. During the study period 42, 68 and 120 patients were identified with carbapenem-resistant, extended-spectrum β-lactamase producers (ESBL) and susceptible K. pneumoniae bloodstream infections, respectively. Patients with carbapenem-resistant K. pneumoniae had higher rates of prior antimicrobial exposure, other nosocomial infections, and use of invasive devices. Infection-related mortality was 48% for carbapenem-resistant, 22% for ESBL producers and 17% for susceptible K. pneumoniae. Independent risk factors for infection-related mortality were Pitt bacteraemia score, Charlson score and carbapenem resistance.

Clinical characteristics of Stenotrophomonas maltophilia infection in hematopoietic stem cell transplantation recipients: a single center experience

Background

Recipients of hematopoietic stem-cell transplantation (HSCT) are at high risk for infections caused by Stenotrophomonas maltophilia.

Methods

We conducted a retrospective analysis of all infections caused by S. maltophilia in HSCT recipients in a single center in Israel during a 4 year period.

Results

Of 570 patients undergoing HSCT, 19 patients with an invasive S. maltophilia infection were identified. Sixteen had allogeneic HSCT and 3 had autologous HSCT. Seventeen patients (90%) had an indwelling central venous catheter (CVC) at the time of infection. S. maltophilia infections were detected in three clinical settings: as a complication of prolonged neutropenia (n = 9), as a CVC-related non-neutropenic infection occurring after CVC manipulation (n = 8) and as a respiratory tract infection (n = 2). Eleven patients (58%) had a polymicrobial infection. Ten patients (52.6%) received carbapenems during the previous month. The treatment for all patients included broad spectrum antibiotics, which were switched according to susceptibilities upon identification of the isolates. All isolates were susceptible in vitro to TMP-SMX. CVCs were removed in 12 patients (70%). Six patients, all after allogeneic HSCT, died. The CVC was removed in only two of the five patients with CVCs who died.

Conclusions

Stenotrophomonas maltophilia is an emerging nosocomial pathogen in HSCT recipients, both in the early neutropenic phase and in the non-neutropenic phase. It is commonly associated with the presence and manipulation of an indwelling CVC. Removal of the CVC in addition to appropriate antibiotic therapy (TMP-SMX) is crucial for infection control.

Studies of the molecular mechanism of caspase-8 activation by solution NMR

Caspases are the key players of apoptosis and inflammation. They are present in the cells as latent precursors, procaspases, and are activated upon an apoptotic or inflammatory stimulus. The activation mechanism of caspases has been studied extensively by biochemical and biophysical methods. Additional structural information on active caspases with a variety of different inhibitors bound at the active site is available. In this study, we investigated the cleavage mechanism of caspase-8 from its zymogen to active caspase-8 by solution NMR and by biochemical methods. The intermolecular cleavage reaction using the catalytically inactive C285A procaspase-8 mutant is triggered by adding caspase-8 and followed by (15)N,(1)H-NMR spectroscopy. The spectrum that initially resembles the one of procaspase-8 gradually over time changes to that of caspase-8, and disappearing peaks display exponential decaying intensities. Removal of either one of the cleavage recognition motifs in the linker, or phosphorylation at Tyr380, is shown to reduce the rate of the cleavage reaction. The data suggest that dimerization repositions the linker to become suitable for intermolecular processing by the associated protomer. Furthermore, analysis of inhibitor binding to the active caspase-8 reveals an induced-fit mechanism for substrate binding.

Structural and biochemical studies on procaspase-8: new insights on initiator caspase activation

Caspases are proteases with an active-site cysteine and aspartate specificity in their substrates. They are involved in apoptotic cell death and inflammation, and dysfunction of these enzymes is directly linked to a variety of diseases. Caspase-8 initiates an apoptotic pathway triggered by external stimuli. It was previously characterized in its active inhibitor bound state by crystallography. Here we present the solution structure of the monomeric unprocessed catalytic domain of the caspase-8 zymogen, procaspase-8, showing for the first time the position of the linker and flexibility of the active site forming loops. Biophysical studies of carefully designed mutants allowed disentangling dimerization and processing, and we could demonstrate lack of activity of monomeric uncleaved procaspase-8 and of a processed but dimerization-incompetent mutant. The data provide experimental support in so-far unprecedented detail, and reveal why caspase-8 (and most likely other initiator caspases) needs the dimerization platform during activation.

Atrial natriuretic peptide during exercise in patients with coronary heart disease before and after single dose atenolol and acebutolol

Plasma atrial natriuretic peptide (ANP) was measured during dynamic exercise in 10 patients with coronary heart disease before and after single dose atenolol 50 mg and acebutolol 200 mg, respectively. Systolic blood pressure, heart rate and the rate-pressure product increased during exercise before and after beta-blockade, but levels were lower after beta-blockade. Plasma ANP levels at rest were unchanged after atenolol, but rose after acebutolol (p less than 0.01). During exercise plasma ANP increased significantly both before and after beta-blockade, but plasma ANP levels were higher after acebutolol at all workloads (p less than 0.05), whereas plasma ANP levels after atenolol were higher at 125 W exclusively (p less than 0.05). The augmented ANP levels during exercise after beta-blockade probably reflect catecholamine-stimulated ANP release, whereas the elevated plasma ANP levels after acebutolol at rest might be a beta-adrenoceptor-mediated ANP release due to the intrinsic sympathomimetic effect of acebutolol.

Electrocardiographic changes in spontaneous left pneumothorax

A 25-year-old man was admitted with severe chest pain and an electrocardiogram suggestive of anterior myocardial infarction. Echocardiogram was normal, but chest X-ray showed left-sided pneumothorax. The electrocardiogram showed increasing R-wave amplitude in the days after correction of pneumothorax. Taken in the supine position the electrocardiogram can be misleading in case of pneumothorax or mediastinal emphysema, but the electrocardiogram should be normal if taken in the erect position.

Changes in plasma atrial natriuretic peptide during exercise in healthy volunteers

Graded exercise was performed in three healthy volunteers. Plasma levels of immunoreactive atrial natriuretic peptide (iANP) were determined at different workloads. Unchanged or slightly decreased plasma levels of iANP were observed during light exercise, whereas at medium to high workloads a considerable increase in plasma levels of iANP was found. Factors responsible for the increase in plasma levels of iANP might include elevated right atrial pressure and increased plasma levels of epinephrine and norepinephrine.

Lipid-bloated subretinal microglial cells are at the origin of drusen appearance in CX3CR1-deficient mice

Drusen, the white yellowish deposits that can be seen in funduscopy, are a hallmark of age-related macular degeneration. Histologically, drusen are believed to be dome-shaped or more confluent lipid accumulations between the retinal pigment epithelium and the choriocapillaries. Recent advances in mouse funduscopy have revealed the presence of drusen-like structures in chemokine knockout animals in the absence of sizeable dome-shaped material below the retinal pigment epithelium. We show that aged CX3CR1-/- mice present with drusen-like appearance in funduscopy that is associated with a progressive age-related microglial cell accumulation in the subretinal space. We demonstrate that the anatomical equivalent of the drusen-like appearance in these mice are lipid-bloated subretinal microglial cells rather than subretinal pigment epithelium deposits [Combadière C, et al: J Clin Invest 2007;117:2920-2928].

Aberrant extradural spinal migration of Spirocerca lupi: four dogs

Spirocerca lupi is a nematode mainly affecting dogs but has been found in other animals, particularly carnivores. Anatomical areas of typical and aberrant migration vary. This report describes four cases of Spirocerca lupi causing neurological symptoms, similar to thoracolumbar disc syndrome, as a result of aberrant migration of the nematode into the spinal canal. In two of the cases, the nematode could be demonstrated intraoperatively. The third was discovered on post-mortem examination, while the fourth case displayed compelling evidence of Spirocerca lupi involvement. Surgical removal of the Spirocerca lupi nematode would be the treatment of choice in cases of spinal migration, with therapeutic and preventive treatment with doramectin instituted to treat remote sites and prevent re-infection. In areas endemic for spirocercosis, Spirocerca lupi should be considered as an important differential diagnosis in cases that are presented with clinical signs suggestive of a spinal cord lesion.

Stable gastric pentadecapeptide BPC 157 in trials for inflammatory bowel disease (PL-10, PLD-116, PL 14736, Pliva, Croatia). Full and distended stomach, and vascular response

Gastric pentadecapeptide BPC 157 (GEPPPGKPADDAGLV, M.W. 1419, safe in clinical trials for inflammatory bowel disease (PL 10, PLD 116, PLD 14736, Pliva, Croatia)) has a particular cytoprotective/adaptive cytoprotective activity. The cytoprotective/adaptive cytoprotection researches largely neglect that stomach distension could per se jeopardize the mucosal integrity, with constantly stretched mucosa and blood vessels, and sphincters more prone for reflux induction. After absolute alcohol instillation in fully distended rat stomach, gastric, esophageal and duodenal lesions occur. Throughout next 3 min, left gastric artery blood vessels clearly disappear at the serosal site, indicative for loss of vessels both integrity and function. Contrary, constant vessels presentation could predict the beneficial effect of applied agent. After pentadecapeptide BPC 157 instillation into the stomach the vessels presentation remains constant, and lesions of stomach, esophagus, and duodenum are inhibited. Standards (atropine, ranitidine, omeprazole) could only slightly improve the vessels presentation compared to control values, and they have only a partial effect on the lesions. In this review we emphasize BPC 157 unusual stability, and some of its important effects: effectiveness against various lesions in gastrointestinal tract, on nitric oxide (NO)-system, and NO-agents effects, on somatosensory neurons, salivary glands function, recovery of AMP-ADP-ATP system, endothelium protection, effect on endothelin, and on angiogenesis promotion. It also antagonizes other alcohol effects, including acute and chronic intoxication. Given peripherally, it counteracts the consequence of central dopamine system disturbances (receptor blockade), and induces serotonin release in substantia nigra. Therapeutic potential of BPC 157 as a cytoprotective agent is also seen in its capability to heal various wounds. Given directly into the stomach, BPC 157 instantly recovers disturbed lower esophageal and pyloric sphincter pressure in rats after 12-20 months of untreated esophagitis. All these could be suggestive for its role as a natural protectant in gastric juice with particular function throughout stomach distension.

An outbreak of Mycobacterium jacuzzii infection following insertion of breast implants

BACKGROUND

Surgical wound infections caused by rapidly growing mycobacteria developed in 15 women after insertion of breast implants from August to November 2003 at a single medical center.

METHODS

A case-control study was conducted that included the identified patients, as well as women who underwent breast operations at the same center who did not develop infections. The study was accompanied by an extensive environmental investigation. Isolates were identified by standard bacteriological methods and by comparison of their 16S rRNA, HSP65, RPOB, SODA, and RECA gene sequences. Isolates were compared by random amplified polymorphic DNA analysis and by pulsed-field gel electrophoresis.

RESULTS

The risk factors for infection included surgery performed by 1 specific surgeon (odds ratio, 21.3; 95% confidence interval, 3.64-125.6). Identical strains of mycobacteria were isolated from the infected wounds of the patients; from the eyebrows, hair, face, nose, ears, and groin of this particular surgeon; and from this surgeon's outdoor whirlpool. The isolates exhibited a biochemical profile overlapping that of Mycobacterium wolinskyi, but their sequences of 16S rRNA and HSP65, RPOB, SODA, and RECA genes differed. We propose the name "Mycobacterium jacuzzii" for this new species. DNA fingerprints of cultured isolates from the surgical wounds, areas of the surgeon's body that grow hair, and the surgeon's whirlpool were identical. When the surgeon discontinued his use of the whirlpool and began cleaning the hairy areas of his body with a shampoo containing triclosan, the outbreak ended.

CONCLUSIONS

This outbreak brings to light the possibility of the colonization of human skin and human-to-human transmission of environmental mycobacteria during surgery that involves implant insertion.