130 research outputs found

    Control of plant stem cell function by conserved interacting transcriptional regulators

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    Plant stem cells in the shoot apical meristem (SAM) and root apical meristem are necessary for postembryonic development of aboveground tissues and roots, respectively, while secondary vascular stem cells sustain vascular development. WUSCHEL (WUS), a homeodomain transcription factor expressed in the rib meristem of the Arabidopsis SAM, is a key regulatory factor controlling SAM stem cell populations, and is thought to establish the shoot stem cell niche through a feedback circuit involving the CLAVATA3 (CLV3) peptide signalling pathway. WUSCHEL-RELATED HOMEOBOX 5 (WOX5), which is specifically expressed in the root quiescent centre, defines quiescent centre identity and functions interchangeably with WUS in the control of shoot and root stem cell niches. WOX4, expressed in Arabidopsis procambial cells, defines the vascular stem cell niche. WUS/WOX family proteins are evolutionarily and functionally conserved throughout the plant kingdom and emerge as key actors in the specification and maintenance of stem cells within all meristems. However, the nature of the genetic regime in stem cell niches that centre on WOX gene function has been elusive, and molecular links underlying conserved WUS/WOX function in stem cell niches remain unknown. Here we demonstrate that the Arabidopsis HAIRY MERISTEM (HAM) family of transcription regulators act as conserved interacting cofactors with WUS/WOX proteins. HAM and WUS share common targets in vivo and their physical interaction is important in driving downstream transcriptional programs and in promoting shoot stem cell proliferation. Differences in the overlapping expression patterns of WOX and HAM family members underlie the formation of diverse stem cell niche locations, and the HAM family is essential for all of these stem cell niches. These findings establish a new framework for the control of stem cell production during plant development

    Application of real-time PCR to quantify hepatitis B virus DNA in chronic carriers in The Gambia

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    BACKGROUND/AIM: The study aimed at developing a real-time quantitative PCR assay to monitor HBV serum virus load of chronic carriers enrolled in therapeutic trials. METHOD: Quantitative real-time PCR assay was carried out using SYBR-Green signal detection and primers specific to the S gene. Thermal cycling was performed in an ABi 5700 sequence detection system. The assay was calibrated against an international HBV DNA standard and inter- and intra-assay reproducibility determined. Levels of viral load were monitored for 1-year in lamivudine treated carriers. Correlation between HBV DNA levels and HBeAg sero-status was determined in untreated carriers. RESULTS: The qPCR assay showed good intra- and inter-assay reproducibility over a wide dynamic range (1.5 Ă— 10(3 )to 1.5 Ă— 10(8 )copies/mL) and correlated well with those from a commercial assay (r = 0.91, (p < 0.001). Viral load levels dropped dramatically but temporarily during and after a short course of lamivudine therapy. HBV DNA was a more reliable indicator of the presence of virus than HBe antigen and was detected in 77.0% (161/209) of HBeAg negative and in all HBeAg positive carriers. CONCLUSION: This method is reliable, accurate, and reproducible. HBV DNA Quantification by qPCR can be used to monitor the efficacy of HBV therapy and useful in understanding the natural history of HBV in an endemic area

    Long-term protection against HBV chronic carriage of Gambian adolescents vaccinated in infancy and immune response in HBV booster trial in adolescence.

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    BACKGROUND: Chronic infection with hepatitis B virus (HBV) arising in childhood is associated with hepatocellular carcinoma in adult life. Between 1986 and 1990, approximately 120,000 Gambian newborns were enrolled in a randomised controlled trial to assess the effectiveness of infant HBV vaccination on the prevention of hepatocellular carcinoma in adulthood. These children are now in adolescence and approaching adulthood, when the onset of sexual activity may challenge their hepatitis B immunity. Thus a booster dose in adolescence could be important to maintain long-term protection. METHODS: Fifteen years after the start of the HBV infant vaccination study, 492 vaccinated and 424 unvaccinated children were identified to determine vaccine efficacy against infection and carriage in adolescence. At the same time, 297 of the 492 infant-vaccinated subjects were randomly offered a booster dose of HBV vaccine. Anti-HBs was measured before the booster, and two weeks and 1 year afterwards (ISRCTN71271385). RESULTS: Vaccine efficacy 15 years after vaccination was 67.0% against infection as manifest by anti-HBc positivity (95% CI 58.2-74.6%), and 96.6% against HBsAg carriage (95% CI 91.5-100%). 31.2% of participants had detectable anti-HBs with a GMC of 32 IU/l. For 168 boosted participants GMC anti-HBs responses were 38 IU/l prior to vaccination, 524 IU/l two weeks after boosting, and 101 IU/l after 1 year. CONCLUSIONS: HBV vaccination in infants confers very good protection against carriage up to 15 years of age, although a large proportion of vaccinated subjects did not have detectable anti-HBs at this age. The response to boosting persisted for at least a year. TRIAL REGISTRATION: Controlled-Trials.com ISRCTN71271385

    Identification of pathways that regulate circadian rhythms using a larval zebrafish small molecule screen

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    The circadian clock ensures that behavioral and physiological processes occur at appropriate times during the 24-hour day/night cycle, and is regulated at both the cellular and organismal levels. To identify pathways acting on intact animals, we performed a small molecule screen using a luminescent reporter of molecular circadian rhythms in zebrafish larvae. We identified both known and novel pathways that affect circadian period, amplitude and phase. Several drugs identified in the screen did not affect circadian rhythms in cultured cells derived from luminescent reporter embryos or in established zebrafish and mammalian cell lines, suggesting they act via mechanisms absent in cell culture. Strikingly, using drugs that promote or inhibit inflammation, as well as a mutant that lacks microglia, we found that inflammatory state affects circadian amplitude. These results demonstrate a benefit of performing drug screens using intact animals and provide novel targets for treating circadian rhythm disorders

    Colistin Resistance in Carbapenem-Resistant Klebsiella pneumoniae: Laboratory Detection and Impact on Mortality

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    Background: Polymyxins including colistin are an important "last-line" treatment for infections caused by carbapenem-resistant Klebsiella pneumoniae (CRKp). Increasing use of colistin has led to resistance to this cationic antimicrobial peptide. Methods: A cohort nested within the Consortium on Resistance against Carbapenems in Klebsiella pneumoniae (CRACKLE) was constructed of patients with infection, or colonization with CRKp isolates tested for colistin susceptibility during the study period of December, 2011 to October, 2014. Reference colistin resistance determination as performed by broth macrodilution was compared to results from clinical microbiology laboratories (Etest) and to polymyxin resistance testing. Each patient was included once, at the time of their first colistin-tested CRKp positive culture. Time to 30-day in-hospital all-cause mortality was evaluated by Kaplan-Meier curves and Cox proportional hazard modeling. Results: In 246 patients with CRKp, 13% possessed ColR CRKp. ColR was underestimated by Etest (very major error rate = 35%, major error rate = 0.4%). A variety of rep-PCR strain types were encountered in both the ColS and the ColR groups. Carbapenem resistance was mediated primarily by blaKPC-2 (46%) and blaKPC-3 (50%). ColR was associated with increased hazard for in-hospital mortality (aHR 3.48; 95% confidence interval, 1.73-6.57; P < .001). The plasmid-associated ColR genes, mcr-1 and mcr-2 were not detected in any of the ColR CRKp. Conclusions: In this cohort, 13% of patients with CRKp presented with ColR CRKp. The apparent polyclonal nature of the isolates suggests de novo emergence of ColR in this cohort as the primary factor driving ColR. Importantly, mortality was increased in patients with ColR isolates

    Responsible, Safe, and Effective Use of Biologics in the Management of Low Back Pain: American Society of Interventional Pain Physicians (ASIPP) Guidelines

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    BACKGROUND: Regenerative medicine is a medical subspecialty that seeks to recruit and enhance the body\u27s own inherent healing armamentarium in the treatment of patient pathology. This therapy\u27s intention is to assist in the repair, and to potentially replace or restore damaged tissue through the use of autologous or allogenic biologics. This field is rising like a Phoenix from the ashes of underperforming conventional therapy midst the hopes and high expectations of patients and medical personnel alike. But, because this is a relatively new area of medicine that has yet to substantiate its outcomes, care must be taken in its public presentation and promises as well as in its use. OBJECTIVE: To provide guidance for the responsible, safe, and effective use of biologic therapy in the lumbar spine. To present a template on which to build standardized therapies using biologics. To ground potential administrators of biologics in the knowledge of the current outcome statistics and to stimulate those interested in providing biologic therapy to participate in high quality research that will ultimately promote and further advance this area of medicine. METHODS: The methodology used has included the development of objectives and key questions. A panel of experts from various medical specialties and subspecialties as well as differing regions collaborated in the formation of these guidelines and submitted (if any) their appropriate disclosures of conflicts of interest. Trustworthy standards were employed in the creation of these guidelines. The literature pertaining to regenerative medicine, its effectiveness, and adverse consequences was thoroughly reviewed using a best evidence synthesis of the available literature. The grading for recommendation was provided as described by the Agency for Healthcare Research and Quality (AHRQ). SUMMARY OF EVIDENCE: Lumbar Disc Injections: Based on the available evidence regarding the use of platelet-rich plasma (PRP), including one high-quality randomized controlled trial (RCT), multiple moderate-quality observational studies, a single-arm meta-analysis and evidence from a systematic review, the qualitative evidence has been assessed as Level III (on a scale of Level I through V) using a qualitative modified approach to the grading of evidence based on best-evidence synthesis. Based on the available evidence regarding the use of medicinal signaling/ mesenchymal stem cell (MSCs) with a high-quality RCT, multiple moderate-quality observational studies, a single-arm meta-analysis, and 2 systematic reviews, the qualitative evidence has been assessed as Level III (on a scale of Level I through V) using a qualitative modified approach to the grading of evidence based on best evidence synthesis. Lumbar Epidural Injections Based on one high-quality RCT, multiple relevant moderate-quality observational studies and a single-arm meta-analysis, the qualitative evidence has been assessed as Level IV (on a scale of Level I through V) using a qualitative modified approach to the grading of evidence based on best evidence synthesis. Lumbar Facet Joint Injections Based on one high-quality RCT and 2 moderate-quality observational studies, the qualitative evidence for facet joint injections with PRP has been assessed as Level IV (on a scale of Level I through V) using a qualitative modified approach to the grading of evidence based on best evidence synthesis. Sacroiliac Joint Injection Based on one high-quality RCT, one moderate-quality observational study, and one low-quality case report, the qualitative evidence has been assessed as Level IV (on a scale of Level I through V) using a qualitative modified approach to the grading of evidence based on best evidence synthesis. CONCLUSION: Based on the evidence synthesis summarized above, there is Level III evidence for intradiscal injections of PRP and MSCs, whereas the evidence is considered Level IV for lumbar facet joint, lumbar epidural, and sacroiliac joint injections of PRP, (on a scale of Level I through V) using a qualitative modified approach to the grading of evidence based on best evidence synthesis.Regenerative therapy should be provided to patients following diagnostic evidence of a need for biologic therapy, following a thorough discussion of the patient\u27s needs and expectations, after properly educating the patient on the use and administration of biologics and in full light of the patient\u27s medical history. Regenerative therapy may be provided independently or in conjunction with other modalities of treatment including a structured exercise program, physical therapy, behavioral therapy, and along with the appropriate conventional medical therapy as necessary. Appropriate precautions should be taken into consideration and followed prior to performing biologic therapy. Multiple guidelines from the Food and Drug Administration (FDA), potential limitations in the use of biologic therapy and the appropriate requirements for compliance with the FDA have been detailed in these guidelines. KEY WORDS: Regenerative medicine, platelet-rich plasma, medicinal signaling cells, mesenchymal stem cells, stromal vascular fraction, bone marrow concentrate, chronic low back pain, discogenic pain, facet joint pain, Food and Drug Administration, minimal manipulation, evidence synthesis

    Risk factors for borderline personality disorder in treatment seeking patients with a substance use disorder: An international multicenter study

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    Borderline personality disorder (BPD) and substance use disorders (SUDs) often co-occur, partly because they share risk factors. In this international multicenter study, risk factors for BPD were examined for SUD patients. In total, 1,205 patients were comprehensively examined by standardized interviews and questionnaires on psychiatric diagnosis and risk factors, and it was found that 1,033 (85.7%) had SUDs without BPD (SUD) and 172 (14.3%) had SUD with BPD (SUD + BPD). SUD + BPD patients were significantly younger, more often females and more often diagnosed with comorbid adult attention deficit/hyperactivity disorder. SUD + BPD patients did not differ from SUD patients on most risk factors typical for SUD such as maternal use of drugs during pregnancy or parents having any SUD. However, SUD + BPD patients did have a higher risk of having experienced emotional and physical abuse, neglect, or family violence in childhood compared to SUD patients, suggesting that child abuse and family violence are BPD-specific risk factors in patients with SUDs

    Failure to Detect the Novel Retrovirus XMRV in Chronic Fatigue Syndrome

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    BACKGROUND:In October 2009 it was reported that 68 of 101 patients with chronic fatigue syndrome (CFS) in the US were infected with a novel gamma retrovirus, xenotropic murine leukaemia virus-related virus (XMRV), a virus previously linked to prostate cancer. This finding, if confirmed, would have a profound effect on the understanding and treatment of an incapacitating disease affecting millions worldwide. We have investigated CFS sufferers in the UK to determine if they are carriers of XMRV. METHODOLOGY:Patients in our CFS cohort had undergone medical screening to exclude detectable organic illness and met the CDC criteria for CFS. DNA extracted from blood samples of 186 CFS patients were screened for XMRV provirus and for the closely related murine leukaemia virus by nested PCR using specific oligonucleotide primers. To control for the integrity of the DNA, the cellular beta-globin gene was amplified. Negative controls (water) and a positive control (XMRV infectious molecular clone DNA) were included. While the beta-globin gene was amplified in all 186 samples, neither XMRV nor MLV sequences were detected. CONCLUSION:XMRV or MLV sequences were not amplified from DNA originating from CFS patients in the UK. Although we found no evidence that XMRV is associated with CFS in the UK, this may be a result of population differences between North America and Europe regarding the general prevalence of XMRV infection, and might also explain the fact that two US groups found XMRV in prostate cancer tissue, while two European studies did not

    Bone Marrow Concentrate (BMC) Therapy in Musculoskeletal Disorders: Evidence-Based Policy Position Statement of American Society of Interventional Pain Physicians (ASIPP)

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    BACKGROUND: The use of bone marrow concentrate (BMC) for treatment of musculoskeletal disorders has become increasingly popular over the last several years, as technology has improved along with the need for better solutions for these pathologies. The use of cellular tissue raises a number of issues regarding the US Food and Drug Administration\u27s (FDA) regulation in classifying these treatments as a drug versus just autologous tissue transplantation. In the case of BMC in musculoskeletal and spine care, this determination will likely hinge on whether BMC is homologous to the musculoskeletal system and spine. OBJECTIVES: The aim of this review is to describe the current regulatory guidelines set in place by the FDA, specifically the terminology around minimal manipulation and homologous use within Regulation 21 CFR Part 1271, and specifically how this applies to the use of BMC in interventional musculoskeletal medicine. METHODS: The methodology utilized here is similar to the methodology utilized in preparation of multiple guidelines employing the experience of a panel of experts from various medical specialties and subspecialties from differing regions of the world. The collaborators who developed these position statements have submitted their appropriate disclosures of conflicts of interest. Trustworthy standards were employed in the creation of these position statements. The literature pertaining to BMC, its effectiveness, adverse consequences, FDA regulations, criteria for meeting the standards of minimal manipulation, and homologous use were comprehensively reviewed using a best evidence synthesis of the available and relevant literature. RESULTS/Summary of Evidence: In conjunction with evidence-based medicine principles, the following position statements were developed: Statement 1: Based on a review of the literature in discussing the preparation of BMC using accepted methodologies, there is strong evidence of minimal manipulation in its preparation, and moderate evidence for homologous utility for various musculoskeletal and spinal conditions qualifies for the same surgical exemption. Statement 2: Assessment of clinical effectiveness based on extensive literature shows emerging evidence for multiple musculoskeletal and spinal conditions. • The evidence is highest for knee osteoarthritis with level II evidence based on relevant systematic reviews, randomized controlled trials and nonrandomized studies. There is level III evidence for knee cartilage conditions. • Based on the relevant systematic reviews, randomized trials, and nonrandomized studies, the evidence for disc injections is level III. • Based on the available literature without appropriate systematic reviews or randomized controlled trials, the evidence for all other conditions is level IV or limited for BMC injections. Statement 3: Based on an extensive review of the literature, there is strong evidence for the safety of BMC when performed by trained physicians with the appropriate precautions under image guidance utilizing a sterile technique. Statement 4: Musculoskeletal disorders and spinal disorders with related disability for economic and human toll, despite advancements with a wide array of treatment modalities. Statement 5: The 21st Century Cures Act was enacted in December 2016 with provisions to accelerate the development and translation of promising new therapies into clinical evaluation and use. Statement 6: Development of cell-based therapies is rapidly proliferating in a number of disease areas, including musculoskeletal disorders and spine. With mixed results, these therapies are greatly outpacing the evidence. The reckless publicity with unsubstantiated claims of beneficial outcomes having putative potential, and has led the FDA Federal Trade Commission (FTC) to issue multiple warnings. Thus the US FDA is considering the appropriateness of using various therapies, including BMC, for homologous use. Statement 7: Since the 1980\u27s and the description of mesenchymal stem cells by Caplan et al, (now called medicinal signaling cells), the use of BMC in musculoskeletal and spinal disorders has been increasing in the management of pain and promoting tissue healing. Statement 8: The Public Health Service Act (PHSA) of the FDA requires minimal manipulation under same surgical procedure exemption. Homologous use of BMC in musculoskeletal and spinal disorders is provided by preclinical and clinical evidence. Statement 9: If the FDA does not accept BMC as homologous, then it will require an Investigational New Drug (IND) classification with FDA (351) cellular drug approval for use. Statement 10: This literature review and these position statements establish compliance with the FDA\u27s intent and corroborates its present description of BMC as homologous with same surgical exemption, and exempt from IND, for use of BMC for treatment of musculoskeletal tissues, such as cartilage, bones, ligaments, muscles, tendons, and spinal discs. CONCLUSIONS: Based on the review of all available and pertinent literature, multiple position statements have been developed showing that BMC in musculoskeletal disorders meets the criteria of minimal manipulation and homologous use. KEY WORDS: Cell-based therapies, bone marrow concentrate, mesenchymal stem cells, medicinal signaling cells, Food and Drug Administration, human cells, tissues, and cellular tissue-based products, Public Health Service Act (PHSA), minimal manipulation, homologous use, same surgical procedure exemption
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