Regulatory T cells in multiple sclerosis and myasthenia gravis.

Multiple sclerosis (MS) is a chronic debilitating disease of the central nervous system primarily mediated by T lymphocytes with specificity to neuronal antigens in genetically susceptible individuals. On the other hand, myasthenia gravis (MG) primarily involves destruction of the neuromuscular junction by antibodies specific to the acetylcholine receptor. Both autoimmune diseases are thought to result from loss of self-tolerance, which allows for the development and function of autoreactive lymphocytes. Although the mechanisms underlying compromised self-tolerance in these and other autoimmune diseases have not been fully elucidated, one possibility is numerical, functional, and/or migratory deficits in T regulatory cells (Tregs). Tregs are thought to play a critical role in the maintenance of peripheral immune tolerance. It is believed that Tregs function by suppressing the effector CD4+ T cell subsets that mediate autoimmune responses. Dysregulation of suppressive and migratory markers on Tregs have been linked to the pathogenesis of both MS and MG. For example, genetic abnormalities have been found in Treg suppressive markers CTLA-4 and CD25, while others have shown a decreased expression of FoxP3 and IL-10. Furthermore, elevated levels of pro-inflammatory cytokines such as IL-6, IL-17, and IFN-γ secreted by T effectors have been noted in MS and MG patients. This review provides several strategies of treatment which have been shown to be effective or are proposed as potential therapies to restore the function of various Treg subsets including Tr1, iTr35, nTregs, and iTregs. Strategies focusing on enhancing the Treg function find importance in cytokines TGF-ß, IDO, interleukins 10, 27, and 35, and ligands Jagged-1 and OX40L. Likewise, strategies which affect Treg migration involve chemokines CCL17 and CXCL11. In pre-clinical animal models of experimental autoimmune encephalomyelitis (EAE) and experimental autoimmune myasthenia gravis (EAMG), several strategies have been shown to ameliorate the disease and thus appear promising for treating patients with MS or MG.

Cattle trypanosomosis: the diversity of trypanosomes and implications for disease epidemiology and control.

Trypanosomosis is one of the most significant infectious threats to cattle in sub-Saharan Africa, and one form has also spread to Asia and South America. The disease is caused by a complex of trypanosome species, and the species and strain of parasite can have a profound influence upon the epidemiology of the host-parasite-vector relationships, the severity and course of infection, and, consequently, the implementation and development of control methods. This review will summarise our current knowledge of the relationship between trypanosome species/genotype and the phenotype of disease in cattle, and the implications that this has for ongoing efforts to develop diagnostics, drugs and vaccines for the control of cattle trypanosomosis.

Polyamine metabolism impacts T cell dysfunction in the oral mucosa of people living with HIV.

Metabolic changes in immune cells contribute to both physiological and pathophysiological outcomes of immune reactions. Here, by comparing protein expression, transcriptome, and salivary metabolome profiles of uninfected and HIV+ individuals, we found perturbations of polyamine metabolism in the oral mucosa of HIV+ patients. Mechanistic studies using an in vitro human tonsil organoid infection model revealed that HIV infection of T cells also resulted in increased polyamine synthesis, which was dependent on the activities of caspase-1, IL-1ß, and ornithine decarboxylase-1. HIV-1 also led to a heightened expression of polyamine synthesis intermediates including ornithine decarboxylase-1 as well as an elevated dysfunctional regulatory T cell (TregDys)/T helper 17 (Th17) cell ratios. Blockade of caspase-1 and polyamine synthesis intermediates reversed the TregDys phenotype showing the direct role of polyamine pathway in altering T cell functions during HIV-1 infection. Lastly, oral mucosal TregDys/Th17 ratios and CD4 hyperactivation positively correlated with salivary putrescine levels, which were found to be elevated in the saliva of HIV+ patients. Thus, by revealing the role of aberrantly increased polyamine synthesis during HIV infection, our study unveils a mechanism by which chronic viral infections could drive distinct T cell effector programs and Treg dysfunction.

A cattle graph genome incorporating global breed diversity.

Despite only 8% of cattle being found in Europe, European breeds dominate current genetic resources. This adversely impacts cattle research in other important global cattle breeds, especially those from Africa for which genomic resources are particularly limited, despite their disproportionate importance to the continent's economies. To mitigate this issue, we have generated assemblies of African breeds, which have been integrated with genomic data for 294 diverse cattle into a graph genome that incorporates global cattle diversity. We illustrate how this more representative reference assembly contains an extra 116.1 Mb (4.2%) of sequence absent from the current Hereford sequence and consequently inaccessible to current studies. We further demonstrate how using this graph genome increases read mapping rates, reduces allelic biases and improves the agreement of structural variant calling with independent optical mapping data. Consequently, we present an improved, more representative, reference assembly that will improve global cattle research.

Toward construct validity for a novel sensorized instrument-based minimally invasive surgery simulation system.

Minimally invasive surgical training is complicated due to the constraints imposed by the surgical environment. Sensorized laparoscopic instruments capable of sensing force in five degrees of freedom and position in six degrees of freedom were evaluated. Novice and expert laparoscopists performed the complex minimally invasive surgical task of suturing using the novel instruments. Their force and position profiles were compared. The novel minimally invasive surgical instrument proved to be construct valid and capable of detecting differences between novices and experts in a laparoscopic suturing task with respect to force and position. Further evaluation is mandated for a better understanding of the ability to predict performance based on force and position as well as the potential for new metrics in minimally invasive surgical education.

Guided interventions in musculoskeletal ultrasound: what's the evidence?

Increasing histological and radiological understanding of the processes involved in soft-tissue injury is leading to novel targeted treatments. A number of reviews have recommended that these treatments should be performed with image guidance. This review describes current ultrasound-guided interventions and injections, together with the level of evidence for these. Discussion of guided interventions will include; percutaneous lavage (barbotage), brisement, dry needling, electrocoagulation, and of guided injections; corticosteroids, autologous substances (blood and platelet rich plasma), sclerosants, and prolotherapy (hyperosmolar dextrose). Representative imaging illustrating some of these techniques is included for correlation with the methods described. As these procedures are often performed in sportspeople, it is essential that the radiologist is aware of prohibited substances and methods outlined in an annual publication from the World Anti-Doping Association (WADA). Finally, future directions, including the use of autologous substances, mesenchymal and stem cells will be discussed.

Hapten-specific responses to the phenyltrimethylamino hapten. III. Mice whose delayed-type hypersensitivity responses cannot be abrogated by the presence of anti-idiotypic suppressor T cells lack a critical modulatory T cell function.

A single intraperitoneal injection of the monovalent synthetic antigen, tyrosinated trimethylaminoaniline [tyr(TMA)] in Freund's complete adjuvant induces an antiidiotypic second-order T suppressor (Ts2) cell population 6 wk later. This population was able to suppress TMA-specific delayed-type hypersensitivity (DTH) responses when adoptively transferred into normal syngeneic recipients. However, they failed to function intrinsically. The inability of the Ts2 to function intrinsically was not caused by compensating idiotype-negative T cells that mediate DTH. Rather, this paradoxical observation was found to be caused by the absence or loss of function of a critical modulatory T cell population in the suppressor cell-bearing mice. This cell is functionally active in normal mice immunized for DTH responses and is sensitive to cyclophosphamide treatment. In addition, this cell type bears idiotype on its surface and is Thy-1+ and Lyt-1-,2+. It was demonstrated that by adoptively transferring the activated modulatory T cells from normal mice into tyr(TMA)-immune recipients, it was possible to observe suppressor cell function intrinsically. The potential importance of modulatory T cell function in the regulation of antibody and DTH responses is discussed.

T cell replacing factor substitutes for an I-J+ idiotype-specific T helper cell.

An in vitro system for the study of idiotype (Id) expression on antitrimethylamino hapten antibody-producing cells and its regulation by two classes of helper T cells is described. These cells are distinguished in four ways: one requires a hapten-carrier bridge and gives a good response that is low in Id; it does not bind to Id-coated dishes and is not affected by anti-I-J plus complement. The other requires antigen but not a hapten-carrier bridge, is bound by Id-coated dishes and is killed by anti-I-J and complement. The Id-specific cell appears to be antigen specific and acts via a soluble factor(s).

Essential role of lymph nodes in contact hypersensitivity revealed in lymphotoxin-alpha-deficient mice.

Lymph nodes (LNs) are important sentinal organs, populated by circulating lymphocytes and antigen-bearing cells exiting the tissue beds. Although cellular and humoral immune responses are induced in LNs by antigenic challenge, it is not known if LNs are essential for acquired immunity. We examined immune responses in mice that lack LNs due to genetic deletion of lymphotoxin ligands or in utero blockade of membrane lymphotoxin. We report that LNs are absolutely required for generating contact hypersensitivity, a T cell-dependent cellular immune response induced by epicutaneous hapten. We show that the homing of epidermal Langerhans cells in response to hapten application is specifically directed to LNs, providing a cellular basis for this unique LN function. In contrast, the spleen cannot mediate contact hypersensitivity because antigen-bearing epidermal Langerhans cells do not access splenic white pulp. Finally, we formally demonstrate that LNs provide a unique environment essential for generating this acquired immune response by reversing the LN defect in lymphotoxin-alpha(-/)- mice, thereby restoring the capacity for contact hypersensitivity.

Interleukin 3-dependent and -independent mast cells stimulated with IgE and antigen express multiple cytokines.

In response to IgE and specific multivalent antigen, mast cell lines (both growth factor-dependent and -independent) induce the transcription and/or secretion of a number of cytokines having a wide spectrum of activities. We have identified IL-1, IL-3, IL-5, IL-6, IFN-gamma, GM-CSF, JE, MIP1 alpha, MIP1 beta, and TCA3 RNA in at least two of four mast cell clones. The production of these products (except JE) is activation-associated and can be induced by IgE plus antigen. In selected instances cytokine expression can also be induced by activation with Con A or phorbol ester plus ionophore, albeit to levels less than those observed with IgE plus antigen. In addition, long-term mast cell clones and primary cultures of bone marrow-derived mast cells specifically release IL-1, IL-4, and/or IL-6 bioactivity after activation. These findings suggest that in addition to their inflammatory effector function mast cells may serve as a source of growth and regulatory factors. The relationship of mast cells to cells of the T lymphocyte lineage is discussed.

The epidemiology and prehospital care of motorcycle crashes in a sub-Saharan African urban center.

OBJECTIVE: Road traffic crashes (RTCs) are common among motorcyclists in Kigali, Rwanda. The Service d'Aide Medicale Urgente (SAMU), a prehospital ambulance service, responds to many of these crashes. We aimed to describe motorcycle-related RTCs managed by SAMU. METHODS: SAMU clinical data including demographic information, injury characteristics, and management details were analyzed descriptively for all motorcycle crashes occurring between December 2012 and July 2016. RESULTS: Every patient included in this study was injured. These patients all called the ambulance for their injuries after a motorcycle crash. There were 2,912 motorcycle-related RTCs over the study period, representing 26% of all patients managed by SAMU. The incidence of motorcycle crashes in Kigali was 258 crashes per 100,000 people over the 3.5-year study period. The average age was 30 years and 80% were males. The most common injuries were to the lower extremities (n = 958, 33%), head (n = 878, 30%), or upper extremities (n = 453, 16%). Injuries often resulted in fractures of extremities (n = 740, 25%) and external hemorrhage anywhere in the body (unspecified region; n = 660, 23%), yet few were severe based on the Kampala Trauma Score (n = 23, 2%) and Glasgow Coma Scale (n = 42, 1.5%). The most common interventions were provision of diclofenac (n = 1,526, 52.5%), peripheral intravenous (IV) access (n = 1,217, 42%), and administration of IV fluids (n = 1,048, 36%). CONCLUSION: Motorcycle-related RTCs represent a large burden of disease for patients treated by SAMU in Kigali, Rwanda. Young men are most at risk of injury, which imposes a financial strain on society. Though injuries occurred frequently, critical trauma cases from motorcycle crashes were uncommon. This may be a result of several initiatives in Rwanda to improve road safety.

Pain in the Prehospital Setting in Rwanda: Results of a Mixed-Methods Quality Improvement Project.

Introduction: Pain is a universal human experience tied to an individual's health but difficult to understand. It is especially important in health emergencies. We performed a two-step quality improvement project to assess pain management by the SAMU ambulance service in Kigali, Rwanda, examining how pain is assessed and treated by ambulance staff to facilitate development of standardized guidelines of pain management in the prehospital setting, which did not exist at the time of the study. Materials and Methods: Deidentified ambulance service records from December 2012 to May 2016 were analyzed descriptively for patient demographics, emergency conditions, pain assessment, and medications given. Then, anonymized, semistructured interviews of ambulance staff were conducted until thematic saturation was achieved. Data were analyzed using a grounded theory approach. Results: SAMU managed 11,161 patients over the study period, of which 6,168 (55%) were documented as reporting pain and 5,010 (45%) received pain medications. Men had greater odds of receiving pain medications compared to women (OR = 3.8, 95% CI (3.5, 4.1), p < 0.01). Twenty interviews were conducted with SAMU staff. They indicated that patients communicate pain in different ways. They reported using informal ways to measure pain or a standardized granular numeric scale. The SAMU team reviewed these results and developed plans to modify practices. Conclusions: We reviewed the existing quality of pain management in the prehospital setting in Kigali, Rwanda, assessed the SAMU staff's perceptions of pain, and facilitated standardization of prehospital pain management through context-specific guidelines.

The association between central venous pressure, pneumoperitoneum, and venous carbon dioxide embolism in laparoscopic hepatectomy.

BACKGROUND: Laparoscopic hepatectomy (LH) is increasingly used. However, the safety and outcomes of LH have yet to be elucidated. The risk of venous gas embolism is increased during liver parenchymal transection. This risk may be increased with positive pressure carbon dioxide (CO(2)) pneumoperitoneum (PP). This may be exacerbated further when low central venous pressure (CVP) anesthesia is used to minimize hemorrhage during liver resection. METHODS: To determine the risk of CO(2) venous embolism, hand-assisted laparoscopic left hepatic lobectomy was performed for 26 domestic pigs. They were divided into three groups involving, respectively, positive gradient (normal-pressure PP of 12-14 mmHg and low CVP of 5-7 mmHg), negative gradient (low-pressure PP of 7-8 mmHg and normal CVP of 10-12 mmHg), and neutral gradient (normal-pressure PP and normal CVP or low-pressure PP and low CVP). Transesophageal echocardiography (TEE) was used intraoperatively to assess the presence of emboli in the suprahepatic vena cava and the right side of the heart. The TEE was recorded and analyzed by blinded observers. Carbon dioxide embolism also was monitored using end-tidal CO(2) and compared with TEE. RESULTS: Carbon dioxide embolism was demonstrated in 19 of the 26 cases. The majority of gas emboli were small gas bubbles associated with dissection of the major hepatic veins. No statistically significant difference in the occurrence of gas emboli was observed between the groups. Of the 19 animals, 18 experienced no significant hemodynamic changes. One pig in the positive gradient group experienced hypotension in relation to gas embolism. The effects were only transient and did not preclude safe completion of the operation. CONCLUSIONS: Carbon dioxide embolism during LH occurs frequently. Clinically, this finding appears to be nominal, but care must be taken when dissection around large veins is performed, and awareness by the surgical and anesthesiology teams of potential venous air embolism is essential. Further evaluation of this phenomenon is required.

Noninvasive in vivo fluorescence measurement of airway-surface liquid depth, salt concentration, and pH.

The concentration of salt in the thin layer of fluid at the surface of large airways, the airway-surface liquid (ASL), is believed to be of central importance in airway physiology and in the pathophysiology of cystic fibrosis. Invasive sampling methods have yielded a wide range of ASL [NaCl] from 40 to 180 mM. We have developed novel fluorescent probes and microscopy methods to measure ASL thickness, salt concentration, and pH quantitatively in cell-culture models and in the trachea in vivo. By rapid z-scanning confocal microscopy, ASL thickness was 21 +/- 4 microm in well-differentiated cultures of bovine tracheal epithelial cells grown on porous supports at an air-liquid interface. By ratio imaging fluorescence microscopy using sodium, chloride, and pH-sensitive fluorescent indicators, ASL [Na+] was 97 +/- 5 mM, [Cl-] was 118 +/- 3 mM, and pH was 6.94 +/- 0.03. In anesthetized mice in which a transparent window was created in the trachea, ASL thickness was 45 +/- 5 microm, [Na+] was 115 +/- 4 mM, [Cl-] was 140 +/- 5 mM, and pH was 6.95 +/- 0.05. Similar ASL tonicity and pH were found in cystic fibrosis (CFTR-null) mice. In freshly harvested human bronchi, ASL thickness was 55 +/- 5 microm, [Na+] was 103 +/- 3 mM, [Cl-] was 92 +/- 4 mM, and pH was 6.78 +/- 0.2. These results establish by a noninvasive approach the key properties of the ASL and provide direct evidence that the ASL is approximately isotonic and not saltier in cystic fibrosis.

Removal of ocular artifacts from EEG using adaptive thresholding of wavelet coefficients.

Electroencephalogram (EEG) gives researchers a non-invasive way to record cerebral activity. It is a valuable tool that helps clinicians to diagnose various neurological disorders and brain diseases. Blinking or moving the eyes produces large electrical potential around the eyes known as electrooculogram. It is a non-cortical activity which spreads across the scalp and contaminates the EEG recordings. These contaminating potentials are called ocular artifacts (OAs). Rejecting contaminated trials causes substantial data loss, and restricting eye movements/blinks limits the possible experimental designs and may affect the cognitive processes under investigation. In this paper, a nonlinear time-scale adaptive denoising system based on a wavelet shrinkage scheme has been used for removing OAs from EEG. The time-scale adaptive algorithm is based on Stein's unbiased risk estimate (SURE) and a soft-like thresholding function which searches for optimal thresholds using a gradient based adaptive algorithm is used. Denoising EEG with the proposed algorithm yields better results in terms of ocular artifact reduction and retention of background EEG activity compared to non-adaptive thresholding methods and the JADE algorithm.

Stapled versus conventional surgery for hemorrhoids.

BACKGROUND: Hemorrhoids are one of the most common anorectal disorders. The Milligan­Morgan open hemorrhoidectomy is the most widely practiced surgical technique used for the management of hemorrhoids and is considered the current "gold standard". Circular stapled hemorrhoidopexy was first described by Longo in 1998 as alternative to conventional excisional hemorrhoidectomy. Early, small randomized­controlled trials comparing stapled hemorrhoidopexy with traditional excisional surgery have shown it to be less painful and that it is associated with quicker recovery. The reports also suggest a better patient acceptance and a higher compliance with day­case procedures potentially making it more economical. A previous Cochrane Review of stapled hemorrhoidopexy and conventional excisional surgery has shown that the stapled technique is associated with a higher risk of recurrent hemorrhoids and some symptoms in long term follow­up. Since this initial review, several more randomized controlled trials have been published that may shed more light on the differences between the novel stapled approach and conventional excisional techniques. OBJECTIVES: This review compares the use of circular stapling devices and conventional excisional techniques in the surgical treatment of hemorrhoids. Its goal is to ascertain whether there is any difference in the outcomes of the two techniques in patients with symptomatic hemorrhoids. SEARCH STRATEGY: We searched all the major electronic databases (MEDLINE, EMBASE, and the Cochrane Central Register of Controlled Trials (CENTRAL) from 1998 to December 2009. SELECTION CRITERIA: All randomized controlled trials comparing stapled hemorrhoidopexy to conventional excisional hemorrhoidal surgeries with a minimum follow­up period of 6 months were included. DATA COLLECTION AND ANALYSIS: Data were collected on a data sheet. When appropriate, an Odds Ratio was generated using a random effects model. MAIN RESULTS: Patients with SH were significantly more likely to have recurrent hemorrhoids in long term follow up at all time points than those with CH (12 trials, 955 patients, OR 3.22, CI 1.59­6.51, p=0.001). There were 37 recurrences out of 479 patients in the stapled group versus only 9 out of 476 patients in the conventional group. Similarly, in trials where there was follow up of one year or more, SH was associated with a greater proportion of patients with hemorrhoid recurrence (5 trials, 417 patients, OR 3.60, CI 1.24­10.49, p=0.02). Furthermore, a significantly higher proportion of patients with SH complained of the symptom of prolapse at all time points (13 studies, 1191 patients, OR 2.65, CI 1.45­4.85, p=0.002). In studies with follow up of greater than one year, the same significant outcome was found (7 studies, 668 patients, OR 3.14, CI 1.20­8.22, p=0.02). Patients undergoing SH were more likely to require an additional operative procedure compared to those who underwent CH (8 papers, 553 patients, OR 2.75, CI 1.31­5.77, p=0.008). When all symptoms were considered, patients undergoing CH surgery were more likely to be asymptomatic (12 trials, 1097 patients, OR 0.59, CI 0.40­0.88). Non significant trends in favor of SH were seen in pain, pruritis ani, and fecal urgency. All other clinical parameters showed trends favoring CH.