1,504 research outputs found

    The expression of genes coding for distinct types of glycine-rich proteins varies according to the biology of three metastriate ticks, Rhipicephalus (Boophilus) microplus, Rhipicephalus sanguineus and Amblyomma cajennense

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    <p>Abstract</p> <p>Background</p> <p>Ticks secrete a cement cone composed of many salivary proteins, some of which are rich in the amino acid glycine in order to attach to their hosts' skin. Glycine-rich proteins (GRPs) are a large family of heterogeneous proteins that have different functions and features; noteworthy are their adhesive and tensile characteristics. These properties may be essential for successful attachment of the metastriate ticks to the host and the prolonged feeding necessary for engorgement. In this work, we analyzed Expressed Sequence Tags (ESTs) similar to GRPs from cDNA libraries constructed from salivary glands of adult female ticks representing three hard, metastriate species in order to verify if their expression correlated with biological differences such as the numbers of hosts ticks feed on during their parasitic life cycle, whether one (monoxenous parasite) or two or more (heteroxenous parasite), and the anatomy of their mouthparts, whether short (Brevirostrata) or long (Longirostrata). These ticks were the monoxenous Brevirostrata tick, <it>Rhipicephalus </it>(Boophilus) <it>microplus</it>, a heteroxenous Brevirostrata tick, <it>Rhipicephalus sanguineus</it>, and a heteroxenous Longirostrata tick, <it>Amblyomma cajennense</it>. To further investigate this relationship, we conducted phylogenetic analyses using sequences of GRPs from these ticks as well as from other species of Brevirostrata and Longirostrata ticks.</p> <p>Results</p> <p>cDNA libraries from salivary glands of the monoxenous tick, <it>R. microplus</it>, contained more contigs of glycine-rich proteins than the two representatives of heteroxenous ticks, <it>R. sanguineus </it>and <it>A. cajennense </it>(33 versus, respectively, 16 and 11). Transcripts of ESTs encoding GRPs were significantly more numerous in the salivary glands of the two Brevirostrata species when compared to the number of transcripts in the Longirostrata tick. The salivary gland libraries from Brevirostrata ticks contained numerous contigs significantly similar to silks of true spiders (17 and 8 in, respectively, <it>R. microplus </it>and <it>R. sanguineus</it>), whereas the Longirostrata tick contained only 4 contigs. The phylogenetic analyses of GRPs from various species of ticks showed that distinct clades encoding proteins with different biochemical properties are represented among species according to their biology.</p> <p>Conclusions</p> <p>We found that different species of ticks rely on different types and amounts of GRPs in order to attach and feed on their hosts. Metastriate ticks with short mouthparts express more transcripts of GRPs than a tick with long mouthparts and the tick that feeds on a single host during its life cycle contain a greater variety of these proteins than ticks that feed on several hosts.</p

    Accelerating Discovery for Complex Neurological and Behavioral Disorders Through Systems Genetics and Integrative Genomics in the Laboratory Mouse

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    Recent advances in systems genetics and integrative functional genomics have greatly improved the study of complex neurological and behavioral traits. The methods developed for the integrated characterization of new, high-resolution mouse genetic reference populations and systems genetics enable behavioral geneticists an unprecedented opportunity to address questions of the molecular basis of neurological and psychiatric disorders and their comorbidities. Integrative genomics augment these strategies by enabling rapid informatics-assisted candidate gene prioritization, cross-species translation, and mechanistic comparison across related disorders from a wealth of existing data in mouse and other model organisms. Ultimately, through these complementary approaches, finding the mechanisms and sources of genetic variation underlying complex neurobehavioral disease related traits is becoming tractable. Furthermore, these methods enable categorization of neurobehavioral disorders through their underlying biological basis. Together, these model organism-based approaches can lead to a refinement of diagnostic categories and targeted treatment of neurological and psychiatric disease

    SILAC-based proteomic quantification of chemoattractant-induced cytoskeleton dynamics on a second to minute timescale

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    Cytoskeletal dynamics during cell behaviours ranging from endocytosis and exocytosis to cell division and movement is controlled by a complex network of signalling pathways, the full details of which are as yet unresolved. Here we show that SILAC-based proteomic methods can be used to characterize the rapid chemoattractant-induced dynamic changes in the actin–myosin cytoskeleton and regulatory elements on a proteome-wide scale with a second to minute timescale resolution. This approach provides novel insights in the ensemble kinetics of key cytoskeletal constituents and association of known and novel identified binding proteins. We validate the proteomic data by detailed microscopy-based analysis of in vivo translocation dynamics for key signalling factors. This rapid large-scale proteomic approach may be applied to other situations where highly dynamic changes in complex cellular compartments are expected to play a key role

    Acute WNT signalling activation perturbs differentiation within the adult stomach and rapidly leads to tumour formation

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    A role for WNT signalling in gastric carcinogenesis has been suggested due to two major observations. First, patients with germline mutations in adenomatous polyposis coli (APC) are susceptible to stomach polyps and second, in gastric cancer, WNT activation confers a poor prognosis. However, the functional significance of deregulated WNT signalling in gastric homoeostasis and cancer is still unclear. In this study we have addressed this by investigating the immediate effects of WNT signalling activation within the stomach epithelium. We have specifically activated the WNT signalling pathway within the mouse adult gastric epithelium via deletion of either glycogen synthase kinase 3 (GSK3) or APC or via expression of a constitutively active ÎČ-catenin protein. WNT pathway deregulation dramatically affects stomach homoeostasis at very short latencies. In the corpus, there is rapid loss of parietal cells with fundic gland polyp (FGP) formation and adenomatous change, which are similar to those observed in familial adenomatous polyposis. In the antrum, adenomas occur from 4 days post-WNT activation. Taken together, these data show a pivotal role for WNT signalling in gastric homoeostasis, FGP formation and adenomagenesis. Loss of the parietal cell population and corresponding FGP formation, an early event in gastric carcinogenesis, as well as antral adenoma formation are immediate effects of nuclear ÎČ-catenin translocation and WNT target gene expression. Furthermore, our inducible murine model will permit a better understanding of the molecular changes required to drive tumourigenesis in the stomach

    Increased circulating ANG II and TNF-α represents important risk factors in obese Saudi adults with hypertension irrespective of diabetic status and BMI

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    Central adiposity is a significant determinant of obesity-related hypertension risk, which may arise due to the pathogenic inflammatory nature of the abdominal fat depot. However, the influence of pro-inflammatory adipokines on blood pressure in the obese hypertensive phenotype has not been well established in Saudi subjects. As such, our study investigated whether inflammatory factors may represent useful biomarkers to delineate hypertension risk in a Saudi cohort with and without hypertension and/or diabetes mellitus type 2 (DMT2). Subjects were subdivided into four groups: healthy lean controls (age: 47.9±5.1 yr; BMI: 22.9±2.1 Kg/m2), non-hypertensive obese (age: 46.1±5.0 yr; BMI: 33.7±4.2 Kg/m2), hypertensive obese (age: 48.6±6.1 yr; BMI: 36.5±7.7 Kg/m2) and hypertensive obese with DMT2 (age: 50.8±6.0 yr; BMI: 35.3±6.7 Kg/m2). Anthropometric data were collected from all subjects and fasting blood samples were utilized for biochemical analysis. Serum angiotensin II (ANG II) levels were elevated in hypertensive obese (p<0.05) and hypertensive obese with DMT2 (p<0.001) compared with normotensive controls. Systolic blood pressure was positively associated with BMI (p<0.001), glucose (p<0.001), insulin (p<0.05), HOMA-IR (p<0.001), leptin (p<0.01), TNF-α (p<0.001) and ANG II (p<0.05). Associations between ANG II and TNF-α with systolic blood pressure remained significant after controlling for BMI. Additionally CRP (p<0.05), leptin (p<0.001) and leptin/adiponectin ratio (p<0.001) were also significantly associated with the hypertension phenotype. In conclusion our data suggests that circulating pro-inflammatory adipokines, particularly ANG II and, TNF-α, represent important factors associated with a hypertension phenotype and may directly contribute to predicting and exacerbating hypertension risk

    Indications and outcome of repeat penetrating keratoplasty in India

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    BACKGROUND: Repeat penetrating keratoplasty is quite often required as there is high chance of failure of the primary graft particularly in the developing world. We planned a study to analyze the indications and outcome of repeat penetrating keratoplasty in a tertiary care centre in India. METHODS: A retrospective analysis of all the patients who underwent repeat penetrating keratoplasty, between January 1999 and December 2001 was performed. The parameters evaluated were indication for the primary penetrating keratoplasty, causes of failure of the previous graft, and final visual outcome and clarity of the repeat corneal grafts. RESULTS: Of fifty-three eyes of 50 patients with repeat penetrating keratoplasty (three patients underwent bilateral corneal regrafts), 37 eyes had undergone one regraft each, 14 eyes two regrafts and two eyes had three regrafts. The follow-up of the patients ranged from one to three years. The most common primary etiologic diagnosis was vascularized corneal scars (66%), of which the scars related to infection were most common (68.5%). Twenty-eight regrafts (52.8%) remained clear at a mean follow-up of 1.54 ± 0.68 years, of which 25 were single regrafts (89.3%). The commonest cause of failure of regraft was infection to the corneal graft (recurrence of herpetic infection in 9 eyes and perforated graft ulcers in 3 eyes). Three (18.6%) of the 16 eyes with multiple corneal regrafts achieved a BCVA of 6/60. Overall, only five eyes (all with single regraft) achieved a BCVA of 6/18 or better at the end of follow-up. CONCLUSION: Graft infection is the leading cause of failure of repeat keratoplasty in this part of the world. Prognosis for visual recovery and graft survival is worse in eyes undergoing multiple regrafts

    Fast track multi-discipline treatment (FTMDT trial) versus conventional treatment in colorectal cancer--the design of a prospective randomized controlled study

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    <p>Abstract</p> <p>Background</p> <p>Laparoscopy-assisted surgery, fast-track perioperative treatment are both increasingly used in colorectal cancer treatment, for their short-time benefits of enhanced recovery and short hospital stays. However, the benefits of the integration of the Laparoscopy-assisted surgery, fast-track perioperative treatment, and even with the Xelox chemotherapy, are still unknown. In this study, the three treatments integration is defined as "Fast Track Multi-Discipline Treatment Model" for colorectal cancer and this model extends the benefits to the whole treatment process of colorectal cancer. The main purpose of the study is to explore the feasibility of "Fast Track Multi-Discipline Treatment" model in treatment of colorectal cancer.</p> <p>Methods</p> <p>The trial is a prospective randomized controlled study with 2 × 2 balanced factorial design. Patients eligible for the study will be randomized to 4 groups: (I) Laparoscopic surgery with fast track perioperative treatment and Xelox chemotherapy; (II) Open surgery with fast track perioperative treatment and Xelox chemotherapy; (III) Laparoscopic surgery with conventional perioperative treatment and mFolfox6 chemotherapy; (IV) Open surgery with conventional perioperative treatment and mFolfox6 chemotherapy. The primary endpoint of this study is the hospital stays. The secondary endpoints are the quality of life, chemotherapy related adverse events, surgical complications and hospitalization costs. Totally, 340 patients will be enrolled with 85 patients in each group.</p> <p>Conclusions</p> <p>The study initiates a new treatment model "Fast Track Multi-Discipline Treatment" for colorectal cancer, and will provide feasibility evidence on the new model "Fast Track Multi-Discipline Treatment" for patients with colorectal cancer.</p> <p>Trial registration</p> <p>ClinicalTrials.gov: <a href="http://www.clinicaltrials.gov/ct2/show/NCT01080547">NCT01080547</a></p
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