CpG-induced secretion of MHCIIβ and exosomes from salmon (Salmo salar) APCs

Major histocompatibility complex class II (MHCII) is encoded by polymorphic genes present in vertebrates and expressed predominately in leukocytes. Upon leukocyte differentiation, intracellular MHCII is dynamically redistributed within the cells and it is expressed at maximal levels on mature antigen presenting cells (APCs). In addition, APCs secrete MHCII within endosome-derived vesicles known as exosomes which possess diverse immunomodulatory properties. Genetic and biochemical data have confirmed that piscine leukocytes express the MHCII components as well as costimulatory molecules that are necessary for the function of APCs. However data concerning the biosynthesis and the distribution of the MHCII complex within leukocytes of lower vertebrates is scarce. The presented data demonstrates for the first time that salmon leukocytes secrete vesicles that contain exosomal markers and the abundance of MHCII indicates that these exosomes are released by APCs. The secretion was specifically induced by CpG stimulation in vitro and it was observed only in head kidney leukocytes but not in splenocyte cultures. Flow cytometry revealed that, unlike splenocytes, the majority of the MHCII-positive head kidney leukocytes were Ig-negative and a population of cells expressing high levels of surface MHCII underwent degranulation upon CpG stimulation suggesting that the MHCII-containing exosomes were derived from maturing salmon APCs. Gene expression analyses have further demonstrated that CpG-B, despite its relatively weak proinflammatory activity compared to LPS, induced expression of a larger group of genes involved in regulation of the adaptive immune response.     

The impact of transcranial direct current stimulation on cerebral vasospasm in a rat model of subarachnoid hemorrhage

Transcranial direct current stimulation (tDCS) has been shown to induce changes in cortical excitability and perfusion in a rat ischemic stroke model. Since perfusion disturbances are a common phenomenon, not only in ischemic but also in hemorrhagic stroke, tDCS might have a possible beneficial effect on cerebral perfusion in hemorrhagic stroke as well. We applied tDCS in a rat model of subarachnoid hemorrhage (SAH) and evaluated its impact on vasospasm. SAH was induced using the double-hemorrhage rat model. TDCS was applied on day 3 and 4. For vasospasm assessment magnetic resonance angiography was performed on day 1, day 2 and day 5. A total of 147 rats were operated, whereat 72 rats died before day 5 and 75 rats survived the whole experiment and could be analyzed. The cathodal group consisted of 26 rats, the anodal group included 24 rats. Thirteen rats served as controls without tDCS, and twelve rats underwent a sham operation. The cathodal group revealed the lowest incidence of new vasospasm on day 5 (p = 0.01), and the lowest mean number of vasospastic vessels per rat (p = 0.02). TDCS influences the vasospasm incidence in an SAH-model in rats, where cathodal-tDCS was associated with a lower vasospasm incidence and severity.     

Dendritic cells produce TSLP that limits the differentiation of Th17 cells, fosters Treg development, and protects against colitis

Thymic stromal lymphopoietin (TSLP) is produced by epithelial cells and keratinocytes, and is involved in immune homeostasis or inflammation. The mechanism through which TSLP regulates intestinal inflammation is unclear. Here, we report that mouse dendritic cells (DCs) express TSLP both in vitro and in vivo in response to Toll-like receptor ligation in a MyD88-dependent fashion. TSLP is produced by the CD103+ subset of tolerogenic gut DCs and is downregulated during experimental colitis. TSLP produced by DCs acts directly on T cells by reducing their capacity to produce interleukin (IL)-17 and fostering the development of Foxp3⁺+ T cells. Consistently, TSLP protects against colitis development through a direct action on T cells, as adoptive transfer of naïve T cells from TSLPR^−/− to SCID mice results in a more severe colitis, with increased frequency of IL-17-producing T cells and inflammatory cytokines. Hence, we describe a new anti-inflammatory role of TSLP in the gut.     

Astrocytic tissue remodeling by the meningitis neurotoxin pneumolysin facilitates pathogen tissue penetration and produces interstitial brain edema

Astrocytes represent a major component of brain tissue and play a critical role in the proper functioning and protection of the brain. Streptococcus pneumoniae, the most common cause of bacterial meningitis, has a high lethality and causes serious disabilities in survivors. Pneumolysin (PLY), a member of the cholesterol-dependent cytolysin group and a major S. pneumoniae neurotoxin, causes deterioration over the course of experimental S. pneumoniae meningitis. At disease-relevant sub-lytic concentrations, PLY produces actin and tubulin reorganization and astrocyte cell shape changes in vitro. In this article, we show that sub-lytic amounts of PLY remodel brain tissue and produce astrocytic process retraction, cortical astroglial reorganization and increased interstitial fluid retention, which is manifested as tissue edema. These changes caused increased tissue permeability to macromolecules and bacteria. The pore-forming capacity of PLY remained necessary for these changes because none of the nonpore-forming mutants were capable of producing similar effects. We suggest that PLY can increase the permeability of brain tissue toward pathogenic factors and bacteria in the course of meningitis, thus contributing to the deterioration caused by the disease.     

Is occupational irritant contact dermatitis predictable by cutaneous bioengineering methods? Results of the Swiss Metalworkers' Eczema Study (PROMETES).

BACKGROUND: Since identification of subjects with high eczema risk by screening tests is desirable, different skin bioengineering methods were studied for their validity as predictive measures for the development of hand eczema. METHODS: 205 metalworker trainees were followed up over 2.5 years from the beginning of their apprenticeship to observe the occurrence of hand eczema. Within the first weeks of their training they underwent a number of noninvasive biophysical tests. Transepidermal water loss, skin moisture and skin roughness were measured, and irritation tests with dimethyl sulfoxide (DMSO), sodium hydroxide (NaOH) and sodium lauryl sulfate were conducted. Sensitivity, specificity and predictive values of the performed tests and test combinations were calculated. RESULTS: None of the observed single biophysical methods can be considered a valid screening test. CONCLUSION: A combination of short irritation tests (DMSO and NaOH tests) and the measurement of skin moisture, however, allows to identify individuals at high risk for hand dermatitis with a high sensitivity, though low specificity.     

Evaluation of four methods of flexor tendon repair for postoperative active mobilization

Evaluation of four methods of flexor tendon repair for postoperative active mobilization@Gu YT @Rice K @Chen F @Pan CZ     

Human neutrophil degranulation during extracorporeal circulation

Cardiopulmonary bypass, especially when prolonged, may result in hemostatic failure and pulmonary dysfunction, which has been attributed to changes in platelets and leukocytes, respectively. It has been well documented that contact of blood with synthetic surfaces causes platelet activation. In this report, we explore mechanisms of the activation of neutrophils during simulated in vitro extracorporeal circulation and document the release of neutrophil lactoferrin and elastase during clinical cardiopulmonary bypass (CCB). Inhibition in the simulated circuit by prostaglandin E1 (PGE1) and lidocaine suggests different mechanisms for release of neutrophil-specific proteins. During CCB with a bubble oxygenator it was observed that platelet counts fell to 42% +/- 2% of baseline. In addition, beta- thromboglobulin antigen (beta TG), a platelet-specific, alpha-granule protein marker reflecting the release reaction, increased from 0.15 +/- 0.05 to 0.84 +/- 0.11 microgram/mL. Neutrophil counts decreased to 67% +/- 7% of prebypass levels but then gradually rose as bypass continued. Both lactoferrin, a neutrophil-specific granule marker, and neutrophil elastase, an azurophilic granule marker, increased in plasma threefold to 1.66 +/- 0.33 micrograms/mL and 1.65 +/- 0.68 microgram/mL, respectively, just before bypass was stopped. When fresh heparinized human blood was recirculated within an extracorporeal membrane oxygenator bypass circuit for 120 minutes, plasma beta-TG rose to 5.13 micrograms/mL, lactoferrin increased from 0.13 +/- 0.04 to 1.62 +/- 0.22 micrograms/mL, and neutrophil elastase rose from 0.05 +/- 0.02 to 1.86 +/- 0.41 micrograms/mL. At 120 minutes, lidocaine (100 mumol/L), which inhibits neutrophil activation, delayed release of lactoferrin (1.33 +/- 0.26 micrograms/mL) and markedly inhibited release of elastase (0.24 +/- 0.05 microgram/mL) but did not inhibit release of beta-TG antigen (5.66 micrograms/mL at 120 minutes). PGE1 (0.3 mumol/L) inhibited significantly the release of beta-TG (0.31 microgram/mL) and elastase (0.52 +/- 0.11 microgram/mL) and attenuated the release of lactoferrin (1.57 +/- 0.45 micrograms/mL).     

Timing of cyber conflict

Nations are accumulating cyber resources in the form of stockpiles of zero-day exploits as well as other novel methods of engaging in future cyber conflict against selected targets. This paper analyzes the optimal timing for the use of such cyber resources. A simple mathematical model is offered to clarify how the timing of such a choice can depend on the stakes involved in the present situation, as well as the characteristics of the resource for exploitation. The model deals with the question of when the resource should be used given that its use today may well prevent it from being available for use later. The analysis provides concepts, theory, applications, and distinctions to promote the understanding strategy aspects of cyber conflict. Case studies include the Stuxnet attack on Iran’s nuclear program, the Iranian cyber attack on the energy firm Saudi Aramco, the persistent cyber espionage carried out by the Chinese military, and an analogous case of economic coercion by China in a dispute with Japan. The effects of the rapidly expanding market for zero-day exploits are also analyzed. The goal of the paper is to promote the understanding of this domain of cyber conflict to mitigate the harm it can do, and harness the capabilities it can provide.The world’s economy and international security have come to depend on what the Council on Foreign Relations called “an open, global, secure, and resilient Internet” (1). From an American point of view, cyber security is essential for the health of the nation’s economy and national security. In fact, the Director of National Security, James R. Clapper, listed cyber security first among the threats facing America today (2). The risks include financial loss, loss of privacy, loss of intellectual property, breaches of national security through cyber espionage, and potential large-scale damage in a war involving cyber sabotage.This paper seeks to contribute to our understanding of cyber conflict by developing ways to analyze the issues, and concepts with which to do the analysis.This paper focuses on one aspect of the problem: the timing of a cyber conflict, either in the form of espionage or disruption. The paper takes the point of view of an actor who has a resource to exploit a vulnerability in a target’s computer system, and a choice of just when to use that resource. The best time to use such a resource depends on the stakes involved in the present situation, as well as the characteristics of the resource for exploitation. A mathematical model is offered to help analyze such a choice. Our model deals with the question of when the resource should be used by the attacker, knowing that its use today may well prevent it from being effective later. The heart of our model is the trade-off between waiting until the stakes of the present situation are high enough to warrant the use of the resource, but not waiting so long that the vulnerability the resource exploits might be discovered and patched even if the resource is never used. The question of when to use a resource to exploit a vulnerability in the target’s computer network is ultimately a matter of human judgment, as Milevski (3) says. The intent of our model is to help in making informed choices about the trade-offs involved in such a judgment.Others studies have clearly recognized that a cyber weapon has a strong tendency to depreciate once used (e.g., ref. 4) The implication has often been more or less explicitly drawn that it may pay to wait for an appropriate moment to deploy such a resource. The next step in the logic has also not escaped the notice of some previous studies, namely that the longer one waits the more likely the target will have recognized and fixed the vulnerability one’s resource is meant to exploit. What is unique here is a formal model that specifies how to conceptualize the variables that are implicit in this logic of the timing of cyber conflict, how to specify the decision problem inherent in the trade-offs among these variables, and how to solve the resulting decision problem.For the present paper, we need a term to describe the means to exploit a specific vulnerability in a given target’s computer system. The term that will be used here is “cyber resource,” or just “resource.” A resource need not be a weapon in the sense of something that can cause damage by itself. It might instead be used for espionage in which case its use is not necessarily an attack. A resource might use one or more zero-day exploits, which are ways to take advantage of hitherto-unknown vulnerabilities in computer software. In addition, a resource to exploit a target’s vulnerability might include nontechnical means such as social engineering or an insider, either on their own or in conjunction with technical means of intrusion.The question of timing is analogous to the question of when to use a double agent to mislead the enemy, where it may be worth waiting for an important event but waiting too long may mean the double agent has been discovered by the target and become useless. The present model is an adaption and extension of the model developed to study “the rational timing of surprise” (5).Our model is presented from the perspective of the offense: when should a cyber resource be used to exploit a vulnerability in a target’s computer network. The results, however, are equally relevant to a defender who wants to estimate how high the stakes have to be in order for the offense to exploit an unknown vulnerability.Section 1 provides a model that expresses the value of a resource for exploiting a vulnerability in the target’s computer system, and then calculates when best to use that resource. The development of our model provides some useful concepts including the Stealth and Persistence of a resource for exploiting a cyber vulnerability. Section 2 applies our model to illuminate some recent cases including the Stuxnet attack on the Iranian nuclear program, the Iranian cyber attack on Saudi Aramco, the persistent cyber espionage carried out by the Chinese military, and Chinese economic warfare against Japan. Section 3 analyzes the effects of the flourishing market for zero-day exploits, i.e., ways to take advantage of hitherto-unknown vulnerabilities in computer software or hardware. Section 4 concludes with a review of concepts, a list of some future avenues for research, and the implications of our model for the future of cyber conflict.     

Ministry of Health Clinical Practice Guidelines: Diabetes Mellitus

The Ministry of Health (MOH) have updated the clinical practice guidelines on Diabetes Mellitus to provide doctors and patients in Singapore with evidence-based treatment for diabetes mellitus. This article reproduces the introduction and executive summary (with recommendations from the guidelines) from the MOH clinical practice guidelines on Diabetes Mellitus, for the information of SMJ readers. Chapters and page numbers mentioned in the reproduced extract refer to the full text of the guidelines, which are available from the Ministry of Health website: http://www.moh.gov.sg/content/moh_web/healthprofessionalsportal/doctors/guidelines/cpg_medical.html. The recommendations should be used with reference to the full text of the guidelines. Following this article are multiple choice questions based on the full text of the guidelines.

1.1 Objectives and scope of guideline

The first edition of the MOH clinical practice guidelines on diabetes mellitus for Singapore was published in 1999. Since that time, more facts about this important condition have emerged, not only with regard to its diagnosis and treatment, but also about whether or not type 2 diabetes may be prevented, and, if so, how this may be achieved.As diabetes mellitus has great public health significance in developed countries and developing nations alike, managing it properly involves a consideration, not just of clinical issues, but also of health economics. This second edition of the guidelines attempts to address some of these complex issues wherever evidence-based information pertaining to them is available.

1.2 Target group

The main aim of these guidelines is to help physicians make sound clinical decisions about diabetes mellitus by presenting up-to-date information about diagnosis, classification, treatment, outcomes, and follow-up.These guidelines are developed for all health care professionals in Singapore. We hope they would be helpful especially to primary care physicians who care for patients with diabetes mellitus.

1.3 Guideline development

These guidelines have been produced by a committee of endocrinologists, family practitioners and primary care specialists, ophthalmologist, dietitian, social worker, and patient representative, appointed by the Ministry of Health. They were developed by the adaptation of existing guidelines, by the review of relevant literature and by expert clinical consensus with consideration of local practice. The guidance does not override the individual responsibility of healthcare professionals to make decisions appropriate to the circumstances of the individual patient, in consultation with the patient and/or guardian or carer.

1.4 What’s new in the revised guidelines

The following is a list of the major revisions and additions to the previous guidelines:

• In Chapter 3, we have explained the rationale for criteria in diagnosing diabetes. In particular, for asymptomatic patients with a first test that meets criteria, we have attempted to provide more clarity on how to choose a second test, and how to interpret the findings.
• Chapter 4 is a new chapter which brings emphasis to two areas contributing towards positive outcomes in diabetes care: diabetes self-management education, and psychosocial assessment and holistic care of the person with diabetes.
• Chapter 5 on pharmacotherapy in diabetes mellitus has been updated to take into account recent clinical trial evidence of the efficacy of the newer classes of pharmacological agents.
• Chapter 6 focuses on glycaemic control, and emphasizes the importance of individualised targets, balancing the benefits of achieving targets without incurring undue risk of hypoglycaemia or other adverse effects, and considering the risk profile of the patient.
• In Chapter 7 on prevention of cardiovascular disease in diabetes mellitus, recommendations on decision-making in the area of therapeutics have been updated and harmonised with current local guidance on lipid, blood pressure and cardiovascular management. Target blood pressure ranges and LDL levels are discussed, as well as the role of antiplatelet therapy.
• Chapter 8 on prevention and management of diabetic nephropathy has been revised to present recent clinical trial evidence regarding the efficacy of, and indications for, the use of angiotensin-converting enzyme inhibitors and angiotensin receptor blockers.
• Chapter 9 on the prevention and management of eye complications has been updated to include developments such as intravitreal injection of anti-vascular endothelial growth factor in patients with diabetic macular oedema.
• Chapter 11 on pre-gestational and gestational diabetes has been updated. Women at high risk for gestational diabetes, but who are not found to have glucose intolerance in early pregnancy, are now recommended to be re-evaluated with a 75 gram OGTT at 24–28 weeks gestation.
• Chapter 13 is a new chapter outlining key principles in the management of the adult with type 1 diabetes, relevant to the primary care healthcare professional.

1.5 Review of guidelines

Evidence-based clinical practice guidelines are only as current as the evidence that supports them. Users must keep in mind that new evidence could supersede recommendations in these guidelines. The workgroup advises that these guidelines be scheduled for review four years after publication, or earlier if new evidence emerges that necessitates substantive changes to the recommendations.Future revisions may include management of hypoglycaemia in persons with diabetes, and evolving areas like bariatric surgery and pancreas/islet cell transplantation.