379 research outputs found

    Fluorescent D-amino-acids reveal bi-cellular cell wall modifications important for Bdellovibrio bacteriovorous predation

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    Modification of essential bacterial peptidoglycan (PG) containing cell walls can lead to antibiotic resistance, for example β-lactam resistance by L,D-transpeptidase activities. Predatory Bdellovibrio bacteriovorus are naturally antibacterial and combat infections by traversing, modifying and finally destroying walls of Gram-negative prey bacteria, modifying their own PG as they grow inside prey. Historically, these multi-enzymatic processes on two similar PG walls have proved challenging to elucidate. Here, with a PG labelling approach utilizing timed pulses of multiple fluorescent D-amino acids (FDAAs), we illuminate dynamic changes that predator and prey walls go through during the different phases of bacteria:bacteria invasion. We show formation of a reinforced circular port-hole in the prey wall; L,D-transpeptidaseBd mediated D-amino acid modifications strengthening prey PG during Bdellovibrio invasion and a zonal mode of predator-elongation. This process is followed by unconventional, multi-point and synchronous septation of the intracellular Bdellovibrio, accommodating odd- and even-numbered progeny formation by non-binary division

    Low-cost liquid medium for in vitro cultivation of Leishmania parasites in low-income countries

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    Background: Cutaneous Leishmaniasis (CL) induced by Leishmania aethiopica has two clinical manifestations: ulcerating, self-healing CL and non-ulcerating, non-healing CL. The grossly disfiguring multiple nodules on the face and exterior surface of limbs during non-ulcerative CL are sometimes misdiagnosed as other skin infections. Thus the need for definitive and prompt laboratory diagnosis will be required. Identifying Leishmania parasite by culture method is considered as a definitive method for initiation of treatment and as an effective component of leishmaniasis control methods. Recently the involvement of Fas (CD95) and Tumor Necrosis Factor (TNF) Related Apoptosis Inducing Ligand (TRAIL) induced apoptotic pathways were proposed to be involved in tissue destruction and ulceration during L. major induced CL. Aims: 1) to develop an alternative culture media that could minimize the cost for culturing Leishmania from patient lesions. 2) to investigate if the expression of FasL and TRAIL differs in ulcerating and non- ulcerative CL. Methods: GALF-1 media was formulated in our lab and compared to RPMI 1640 medium and conventional Locke s semi solid media (LSSM) which is one of the modifications of Novy-MacNeal-Nicolle (NNN) culture media. Amastigotes transformation, cryopreservation, recovery of parasites, cost and mass cultivation were analysed. Expression of Fas ligand (FasL), TRAIL and apoptosis were assessed by immunohistology in human skin biopsies from L. aethiopica induced ulcerative or non-ulcerative CL. FasL and TRAIL blocking experiments were performed in a murine model of CL. Results and discussion: GALF-1 is cheap and its ingredients available in a low income country such as Ethiopia. GALF-1 was able to transform amastigotes from Ethiopian patients samples and could be used to cultivate promastigotes in large quantities. Cost analysis showed 80% to 95 % decreased costs as compared to conventional media. Promastigotes cultured with GALF-1 could be cryopreserved in liquid nitrogen with comparable re-culture potential to conventional media. Affordability of diagnostic assays is a key issue for resource poor countries and the possibility to cut the cost of the efficient culture method for diagnosis through the use of inexpensive local formulated reagents could improve the diagnosis of leishmaniasis in low income endemic countries. More FasL expressing cells were detected in dermis of ulcerative CL as compared to non-ulcerative CL and controls. TRAIL expression was higher in ulcerative CL as compared to non-ulcerative CL and controls in both epidermis and dermis. Increased dermal expression of FasL and TRAIL was associated with ulcer formation during CL. This correlated with an inhibition of the ulcerative process in a murine CL model during FasL and TRAIL neutralisation.The mechanisms of the involvement of FasL and TRAIL in ulceration was not elucidated and putative reason(s) for the difference in dysregulation of apoptosis are discussed

    Physiotherapy scoliosis-specific exercises: a comprehensive review of seven major schools

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    In recent decades, there has been a call for change among all stakeholders involved in scoliosis management. Parents of children with scoliosis have complained about the so-called “wait and see” approach that far too many doctors use when evaluating children’s scoliosis curves between 10° and 25°. Observation, Physiotherapy Scoliosis Specific Exercises (PSSE) and bracing for idiopathic scoliosis during growth are all therapeutic interventions accepted by the 2011 International Society on Scoliosis Orthopaedic and Rehabilitation Treatment (SOSORT). The standard features of these interventions are: 1) 3-dimension self-correction; 2) Training activities of daily living (ADL); and 3) Stabilization of the corrected posture. PSSE is part of a scoliosis care model that includes scoliosis specific education, scoliosis specific physical therapy exercises, observation or surveillance, psychological support and intervention, bracing and surgery. The model is oriented to the patient. Diagnosis and patient evaluation is essential in this model looking at a patient-oriented decision according to clinical experience, scientific evidence and patient’s preference. Thus, specific exercises are not considered as an alternative to bracing or surgery but as a therapeutic intervention, which can be used alone or in combination with bracing or surgery according to individual indication. In the PSSE model it is recommended that the physical therapist work as part of a multidisciplinary team including the orthopeadic doctor, the orthotist, and the mental health care provider - all are according to the SOSORT guidelines and Scoliosis Research Society (SRS) philosophy. From clinical experiences, PSSE can temporarily stabilize progressive scoliosis curves during the secondary period of progression, more than a year after passing the peak of growth. In non-progressive scoliosis, the regular practice of PSSE could produce a temporary and significant reduction of the Cobb angle. PSSE can also produce benefits in subjects with scoliosis other than reducing the Cobb angle, like improving back asymmetry, based on 3D self-correction and stabilization of a stable 3D corrected posture, as well as the secondary muscle imbalance and related pain. In more severe cases of thoracic scoliosis, it can also improve breathing function. This paper will discuss in detail seven major scoliosis schools and their approaches to PSSE, including their bracing techniques and scientific evidence. The aim of this paper is to understand and learn about the different international treatment methods so that physical therapists can incorporate the best from each into their own practices, and in that way attempt to improve the conservative management of patients with idiopathic scoliosis. These schools are presented in the historical order in which they were developed. They include the Lyon approach from France, the Katharina Schroth Asklepios approach from Germany, the Scientific Exercise Approach to Scoliosis (SEAS) from Italy, the Barcelona Scoliosis Physical Therapy School approach (BSPTS) from Spain, the Dobomed approach from Poland, the Side Shift approach from the United Kingdom, and the Functional Individual Therapy of Scoliosis approach (FITS) from Poland

    A Major Role for Perifornical Orexin Neurons in the Control of Glucose Metabolism in Rats

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    OBJECTIVE-The hypothalamic neuropeptide orexin influences (feeding) behavior as well as energy metabolism. Administration of exogenous orexin-A into the brain has been shown to increase both food intake and blood glucose levels. In the present study, we investigated the role of endogenous hypothalamic orexin release in glucose homeostasis in rats. RESEARCH DESIGN AND METHODS-We investigated the effects of the hypothalamic orexin system on basal endogenous glucose production (EGP) as well as on hepatic and peripheral insulin sensitivity by changing orexinergic activity in the hypothalamus combined with hepatic sympathetic or parasympathetic denervation, two-step hyperinsulinemic-euglycemic clamps, immunohistochemistry, and RT-PCR studies. RESULTS-Hypothalamic disinhibition of neuronal activity by the gamma-aminobutyric acid receptor antagonist bicuculline (BIC) increased basal EGP, especially when BIC was administered in the perifornical area where orexin-containing neurons but not melanocortin-concentrating hormone-containing neurons were activated. The increased BIC-induced EGP was largely prevented by intracerebroventricular pretreatment with the orexin-1 receptor antagonist. Intracerebroventricular administration of orexin-A itself caused an increase in plasma glucose and prevented the daytime decrease of EGP. The stimulatory effect of intracerebroventricular orexin-A on EGP was prevented by hepatic sympathetic denervation. Plasma insulin clamped at two or six times the basal levels did not counteract the stimulatory effect of perifornical BIC on EGP, indicating hepatic insulin resistance. RT-PCR showed that stimulation of orexin neurons increased the expression of hepatic glucoregulatory enzymes. CONCLUSIONS-Hypothalamic orexin plays an important role in EGP, most likely by changing the hypothalamic output to the autonomic nervous system. Disturbance of this pathway may result in unbalanced glucose homeostasis. Diabetes 58:1998-2005, 200

    Feasibility study of intelligent autonomous determination of the bladder voiding need to treat bedwetting using ultrasound and smartphone ML techniques

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    Unsatisfactory cure rates for the treatment of nocturnal enuresis (NE), i.e. bed-wetting, have led to the need to explore alternative modalities. New treatment methods that focus on preventing enuretic episodes by means of a pre-void alerting system could improve outcomes for children with NE in many aspects. No such technology exists currently to monitor the bladder to alarm before bed-wetting. The aim of this study is to carry out the feasibility of building, refining and evaluating a new, safe, comfortable and non-invasive wearable autonomous intelligent electronic device to monitor the bladder using a single-element low-powered low-frequency ultrasound with the help of Machine Learning techniques and to treat NE by warning the patient at the pre-void stage, enhancing quality of life for these children starting from the first use. The sensitivity and specificity values are 0.89 and 0.93 respectively for determining imminent voiding need. The results indicate that customised imminent voiding need based on the expansion of the bladder can be determined by applying a single-element transducer on a bladder in intermittent manner. The acquired results can be improved further with a comfortable non-invasive device by adding several more features to the current features employed in this pilot study

    Transperineal prostate biopsies for diagnosis of prostate cancer are well tolerated: a prospective study using patient-reported outcome measures

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    We aimed to determine short-term patient-reported outcomes in men having general anesthetic transperineal (TP) prostate biopsies. A prospective cohort study was performed in men having a diagnostic TP biopsy. This was done using a validated and adapted questionnaire immediately post-biopsy and at follow-up of between 7 and 14 days across three tertiary referral hospitals with a response rate of 51.6%. Immediately after biopsy 43/201 (21.4%) of men felt light-headed, syncopal, or suffered syncope. Fifty-three percent of men felt discomfort after biopsy (with 95% scoring <5 in a 0-10 scale). Twelve out of 196 men (6.1%) felt pain immediately after the procedure. Despite a high incidence of symptoms (e.g., up to 75% had some hematuria, 47% suffered some pain), it was not a moderate or serious problem for most, apart from hemoejaculate which 31 men suffered. Eleven men needed catheterization (5.5%). There were no inpatient admissions due to complications (hematuria, sepsis). On repeat questioning at a later time point, only 25/199 (12.6%) of men said repeat biopsy would be a significant problem despite a significant and marked reduction in erectile function after the procedure. From this study, we conclude that TP biopsy is well tolerated with similar side effect profiles and attitudes of men to repeat biopsy to men having TRUS biopsies. These data allow informed counseling of men prior to TP biopsy and a benchmark for tolerability with local anesthetic TP biopsies being developed for clinical use.Boris Hadaschik received funding from the German Research Foundation and the European Foundation for Urology. Karan Wadhwa is sponsored by a Medical Research Council Research Training Fellowship. No other funding was received for this work

    Dysferlin Forms a Dimer Mediated by the C2 Domains and the Transmembrane Domain In Vitro and in Living Cells

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    Dysferlin was previously identified as a key player in muscle membrane repair and its deficiency leads to the development of muscular dystrophy and cardiomyopathy. However, little is known about the oligomerization of this protein in the plasma membrane. Here we report for the first time that dysferlin forms a dimer in vitro and in living adult skeletal muscle fibers isolated from mice. Endogenous dysferlin from rabbit skeletal muscle exists primarily as a ∼460 kDa species in detergent-solubilized muscle homogenate, as shown by sucrose gradient fractionation, gel filtration and cross-linking assays. Fluorescent protein (YFP) labeled human dysferlin forms a dimer in vitro, as demonstrated by fluorescence correlation spectroscopy (FCS) and photon counting histogram (PCH) analyses. Dysferlin also dimerizes in living cells, as probed by fluorescence resonance energy transfer (FRET). Domain mapping FRET experiments showed that dysferlin dimerization is mediated by its transmembrane domain and by multiple C2 domains. However, C2A did not significantly contribute to dimerization; notably, this is the only C2 domain in dysferlin known to engage in a Ca-dependent interaction with cell membranes. Taken together, the data suggest that Ca-insensitive C2 domains mediate high affinity self-association of dysferlin in a parallel homodimer, leaving the Ca-sensitive C2A domain free to interact with membranes
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