viernes, 31 de agosto de 2018

A look at drug craving | National Institute on Drug Abuse (NIDA)

A look at drug craving | National Institute on Drug Abuse (NIDA)

NIDA



A look at drug craving



Science Highlight

August 28, 2018
The concept of thinking background with brainThe concept of thinking.©Shutterstock/vladguk
Studies using animal models of addiction have shown that drug seeking progressively increases after drug self-administration stops, which is a phenomenon called incubation of drug craving. Using neuroanatomical and neuropharmacological methods to measure brain activity, NIDA neuroscientists have identified a novel motivation-related thalamus-to-striatum brain projection that is critical to incubation of methamphetamine craving in the rat model. Identifying brain projections related to incubation of drug craving could provide new insights on the circuits that control drug craving and relapse.

Study:

Novel intervention halves rate of death among people living with HIV who inject drugs | National Institutes of Health (NIH)

Novel intervention halves rate of death among people living with HIV who inject drugs | National Institutes of Health (NIH)

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Novel intervention halves rate of death among people living with HIV who inject drugs

NIH-supported study finds intervention boosts treatment participation, HIV suppression.
An intervention designed to facilitate treatment for HIV and substance use was associated with a 50 percent reduction in mortality for people living with HIV who inject illicit drugs, a study has found. In addition, the people who received the intervention were nearly twice as likely to report being in treatment for HIV and substance use after one year as those who received their national standard of care. They also were about twice as likely to have suppressed their HIV to undetectable levels after one year. The intervention consisted of psychosocial counseling along with guidance and support navigating the healthcare system. These findings were reported today in the journal The Lancet.
People who inject drugs often have high rates of HIV infection, poor access to and use of treatment for HIV and substance use, and high mortality in the United States and globally. Needle sharing among people who inject drugs is the main route of HIV transmission in some parts of the world.
“People living with HIV who inject drugs often encounter multiple obstacles to beginning and adhering to treatment for HIV infection and substance use,” said Anthony S. Fauci, M.D., director of the National Institute of Allergy and Infectious Diseases (NIAID), part of the National Institutes of Health. “This study demonstrates that providing guidance and counseling can help such individuals overcome barriers to starting and staying in care and treatment, leading to a significantly higher rate of HIV suppression and a much lower rate of death.”
NIAID co-funded the study with the National Institute on Drug Abuse (NIDA), also part of NIH. The NIH-funded HIV Prevention Trials Network (HPTN) implemented the trial, called HPTN 074.
“People who inject drugs and are living with HIV have potentially fatal co-occurring conditions, yet they and their at-risk partners often face different and confusing care delivery systems,” said NIDA Director Nora D. Volkow, M.D. “This study shows that integrated interventions, including help from systems navigators, can dramatically reduce mortality for both conditions.”
None of the few new HIV infections in the trial occurred among the injection partners of people living with HIV who received the study intervention. Scientists could not draw a firm conclusion about the impact of the intervention on HIV transmission through injection drug use, however, because the study was not statistically powered to measure that effect. 
HPTN 074 took place in three countries with HIV epidemics driven by injection drug use: Indonesia, Ukraine and Vietnam. The study team enrolled 502 men and women ages 18–60 years who are living with HIV and inject drugs, and 806 HIV-uninfected men and women who inject drugs with them (injection partners). At least one injection partner of every person in the study living with HIV enrolled. The people living with HIV were assigned at random to receive either the national standard of care for HIV infection and substance use or the standard of care plus an integrated and flexible intervention designed to facilitate treatment. The study participants were followed for one to two years.
Study participants assigned to receive the intervention were immediately referred to local health-care providers for anti-HIV therapy to treat their infection, prevent sexual transmission of HIV, and potentially prevent HIV transmission via needle sharing. In addition, each participant who received the study intervention was assigned a systems navigator who helped the participant identify and overcome structural barriers to starting and staying in care and treatment for HIV and substance use. Such barriers could include unfamiliarity with how to enroll in medical care for HIV or difficulty keeping treatment-related appointments. Finally, psychosocial counselors helped each study participant overcome their unique psychological obstacles to starting and staying in treatment, such as lack of interest in therapy, difficulty establishing a medication-taking routine, or stigma.
In addition, all study participants, including the HIV-uninfected injection partners, received their country’s standard of care for people who inject drugs. This typically included referral for treatment of substance use; referral to needle/syringe exchange programs, if legal and available; injection risk reduction counseling; sexual risk reduction counseling; HIV counseling and testing; and referral for diagnosis and treatment of sexually transmitted infections, hepatitis B and C viruses, and tuberculosis, as appropriate. Those study participants living with HIV who received only the standard of care also were referred to local health-care providers for anti-HIV therapy according to national guidelines for when to start treatment.
At the end of the study, 15 percent of participants with HIV who had received the standard of care had died, compared to seven percent of participants with HIV who had received the intervention, corresponding to a 53 percent reduction in mortality.
Some 26 percent of deaths among study participants who had HIV were considered clearly HIV-related, and 3 percent were due to drug overdose. Among the 42 percent of deaths with unknown cause, 24 percent occurred among people whose immune systems were in poor health. Non-HIV-related medical events caused 21 percent of deaths overall, and trauma and suicide accounted for the remaining eight percent.  
After one year, 41 percent of study participants who received the intervention had undetectable levels of HIV in their blood, compared to 24 percent of participants who received only the standard of care. Also, 72 percent of study participants who received the intervention reported being in treatment for HIV at the end of one year, compared to 43 percent of those who received only the standard of care. Forty-one percent of study participants who received the intervention reported being in treatment for substance use at the end of one year, compared to 25 percent of those who received only the standard of care.
“The intervention in this study had a remarkably positive impact on people living with HIV who inject drugs,” said Protocol Chair William C. Miller, M.D., Ph.D. “It was designed to be scalable to other settings, and we hope that it can help this important population worldwide.” Dr. Miller is professor and chair of the Division of Epidemiology at The Ohio State University College of Public Health in Columbus.
Previous studies have demonstrated that when a person takes anti-HIV medication that suppresses the amount of virus in the blood to undetectable levels, it both protects the health of the individual and prevents sexual transmission of the virus. Whether viral suppression also prevents HIV transmission through needle sharing with injection partners remains unknown. The HPTN 074 study was not designed to determine whether the intervention would reduce the rate of HIV infection among injection partners of the participants living with HIV, but rather to determine the feasibility of a larger study that could measure this effect. In HPTN 074, seven injection partners of participants living with HIV who received only the standard of care became infected, while no injection partners of participants living with HIV who received the study intervention became infected. This result is promising, according to the investigators, but because the overall HIV incidence among injection partners was so low, a larger clinical trial to test the effect of the study intervention on HIV transmission among injection drug users would not be feasible.
Given the success of the study intervention at reducing mortality and increasing the rates of both participation in treatment and viral suppression, investigators have offered the intervention to all the HPTN 074 study participants living with HIV. In addition, all participants living with HIV are being followed for a second year to determine whether the positive effects of the intervention are maintained.
NIAID conducts and supports research — at NIH, throughout the United States, and worldwide — to study the causes of infectious and immune-mediated diseases, and to develop better means of preventing, diagnosing and treating these illnesses. News releases, fact sheets and other NIAID-related materials are available on the NIAID website.
About the National Institute on Drug Abuse (NIDA): The National Institute on Drug Abuse (NIDA) is a component of the National Institutes of Health, U.S. Department of Health and Human Services. NIDA supports most of the world’s research on the health aspects of drug use and addiction. The Institute carries out a large variety of programs to inform policy, improve practice, and advance addiction science. Fact sheets on the health effects of drugs and information on NIDA research and other activities can be found at www.drugabuse.gov, which is now compatible with your smartphone, iPad or tablet. To order publications in English or Spanish, call NIDA’s DrugPubs research dissemination center at 1-877-NIDA-NIH or 240-645-0228 (TDD) or email requests to drugpubs@nida.nih.gov(link sends e-mail). Online ordering is available at drugpubs.drugabuse.gov. NIDA’s media guide can be found at www.drugabuse.gov/publications/media-guide/dear-journalist, and its easy-to-read website can be found at www.easyread.drugabuse.gov. You can follow NIDA on Twitter(link is external) and Facebook(link is external).
About the National Institutes of Health (NIH): NIH, the nation's medical research agency, includes 27 Institutes and Centers and is a component of the U.S. Department of Health and Human Services. NIH is the primary federal agency conducting and supporting basic, clinical, and translational medical research, and is investigating the causes, treatments, and cures for both common and rare diseases. For more information about NIH and its programs, visit www.nih.gov.
NIH…Turning Discovery Into Health®

Genetics and pollution drive severity of asthma symptoms | National Institutes of Health (NIH)

Genetics and pollution drive severity of asthma symptoms | National Institutes of Health (NIH)

National Institutes of Health (NIH) - Turning Discovery into Health



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Genetics and pollution drive severity of asthma symptoms

Asthma patients, with a specific genetic profile, exhibit more intense symptoms following exposure to traffic pollution, according to researchers at the National Institutes of Health and collaborators. The study appeared online in Scientific Reports.
The research team, made up of scientists from the National Institute of Environmental Health Sciences (NIEHS), part of NIH, and Rice University, Houston, also found that asthma patients that lack this genetic profile do not have the same sensitivity to traffic pollution and do not experience worse asthma symptoms. The work brings scientists closer to being able to use precision medicine, an emerging field that intends to prevent and treat disease based on factors specific to an individual.
Co-lead author Shepherd Schurman, M.D., associate medical director of the NIEHS Clinical Research Unit, stated the results are based on genetic variation, the subtle differences in DNA that make each person unique. He further added that to understand the concept, one should think of human genes, which are made up of DNA base pairs A, C, G, and T, as written instructions for making proteins.
"All humans have the same genes, in other words the same basic instructions, but in some people one DNA base pair has been changed," Schurman said. "This common type of genetic variation is called a single nucleotide polymorphism or SNP, and it can alter the way proteins are made and make individuals more or less prone to illness."
Schurman is also head of the Environmental Polymorphisms Registry (EPR), the DNA bank in North Carolina that provided volunteers for the study. The EPR studies how SNPs impact disease risk in combination with environmental exposures.
Together with NIEHS colleague and lung disease expert Stavros Garantziotis, M.D., medical director of the NIEHS Clinical Research Unit, the two scientists examined four SNPs that are involved in a biochemical pathway that leads to inflammatory responses in the body. They explained that SNPs are usually studied one at a time, but they wanted to learn if different combinations of these SNPs, along with pollution exposure, could worsen symptoms in a person with an inflammatory disease like asthma.
Schurman and Garantziotis gathered information about the SNPs, severity of asthma symptoms, and residential addresses of 2,704 EPR participants with asthma. Using the SNPs data, they divided the participants into three groups: hyper-responders, or those very sensitive to air pollution and likely to develop inflammation; hypo-responders, or those insensitive to air pollution and less likely to develop inflammation; and those in between. With the help of collaborators at Rice University, the team used the participants’ addresses to calculate their distance from a major road. Participants were categorized depending on whether they lived more or less than 275 yards from a major roadway. Data suggest that air pollution levels are elevated closer to major roads.
The researchers found that asthma sufferers who were hyper-responders and lived closer to heavily travelled roads had the worst asthma symptoms, such as difficulty breathing, chest pain, cough, and wheezing, compared to the other groups. In contrast, asthma patients who were hypo-responders and lived further away from busy roads had milder symptoms. Garantziotis concluded the work could greatly enhance the quality of life for people with asthma.
"Based on this research, we could propose that hyper-responders, who are exposed to traffic pollution, receive air purification intervention, such as HEPA filters, for their home," Garantziotis said.
NIEHS Clinical Director Janet Hall, M.D., said the results emphasize the importance of gene-environment interactions in the progression of disease.
"This research is a great example of how we can approach disease prevention on a personal level, and tailor our treatments to suit individual patients," she said. "That way we can be more efficient with our treatments and preventative measures, while at the same time cutting health care costs."
Grant Numbers: ZIDES102465, ZIAES102605
About the National Institute of Environmental Health Sciences: NIEHS supports research to understand the effects of the environment on human health and is part of the National Institutes of Health. For more information on NIEHS or environmental health topics, visit www.niehs.nih.gov or subscribe to a news list.
About the National Institutes of Health (NIH): NIH, the nation's medical research agency, includes 27 Institutes and Centers and is a component of the U.S. Department of Health and Human Services. NIH is the primary federal agency conducting and supporting basic, clinical, and translational medical research, and is investigating the causes, treatments, and cures for both common and rare diseases. For more information about NIH and its programs, visit www.nih.gov.
NIH…Turning Discovery Into Health®

Reference

Schurman SH, Bravo MA, Innes CL, Jackson WB 2nd, McGrath JA, Miranda ML, Garantziotis S. 2018. Toll-like receptor 4 pathway polymorphisms interact with pollution to influence asthma diagnosis and severity. Sci Rep; doi: 10.1038/s41598-018-30865-0 [Online 23 August 2018].

New guideline developed to help physicians diagnose idiopathic pulmonary fibrosis

New guideline developed to help physicians diagnose idiopathic pulmonary fibrosis

News-Medical

New guideline developed to help physicians diagnose idiopathic pulmonary fibrosis

A new international guideline has been developed to help physicians diagnosis idiopathic pulmonary fibrosis (IPF), a rare and often fatal lung disease whose cause is unknown.
The 2018 clinical practice guideline was developed by experts representing four major respiratory societies-;the American Thoracic Society (ATS), the European Respiratory Society (ERS), Japanese Respiratory Society (JRS) and the Latin American Thoracic Society (ALAT)-;and published online and in the American Thoracic Society's Sept. 1 edition of the American Journal of Respiratory and Critical Care Medicine.
IPF is the most common and deadly form of a group of more than 200 conditions known broadly as interstitial lung disease. Most often, IPF is diagnosed in adults over age 60 and more often in men than women. Symptoms include shortness of breath, a dry cough and low oxygen levels. The median survival is three to five years after the diagnosis.
"Diagnosing IPF is challenging because these symptoms are non-specific: they occur with all other interstitial lung diseases and with other respiratory problems," said Ganesh Raghu, MD, chair of the guideline committee and professor of medicine and director of the Center for Interstitial Lung Disease at the University of Washington in Seattle. "Because drugs may slow the progression of IPF, an early and accurate diagnosis is essential for prompt and appropriate treatment for this fatal disease."
The 29-member guideline committee included international clinical and scientific experts and an IPF patient. The committee discussed the findings of all accumulated evidence pertinent to IPF, rated the strength of those findings using the GRADE (Grading of Recommendations, Assessment, Development and Evaluation) system and made recommendations.
"The approach used to develop the guidelines adhered strictly to the state-of-the-art Institute of Medicine Standards for Trustworthy Guidelines," said Kevin C. Wilson, MD, lead methodologist and project manager, as well as professor of medicine at Boston University School of Medicine. "This should provide the health care community with confidence that the recommendations are as unbiased and evidence-based as possible."
The 2018 guideline is an update of IPF diagnostic guidelines the four respiratory societies produced in 2011.
"The 2011 guideline provided the first evidence-based, formal criteria for diagnosis of IPF and allowed patients with a well-defined diagnosis of IPF to participate in numerous clinical studies and randomized controlled trials that enhanced our understanding of the disease," Dr. Raghu said. "However, it became clear that there were significant challenges in ascertaining the diagnosis per the 2011 criteria, and abundant evidence accumulated since then allowed the committee to refine the diagnostic criteria now."
Chief among the refinements included in the criteria is the use of four diagnostic categories based on high-resolution tomography (HRCT) of the lung: usual interstitial pneumonia (UIP) pattern, probable UIP pattern, indeterminate pattern and alternative diagnosis.
The committee recommended the same terminology for both images produced using HRCT of the lung and microscopic analysis of biopsied tissue. Consistent categorization should facilitate multidisciplinary discussions (MDD) between a pulmonologist (and in some cases, a rheumatologist), radiologist and pathologist of a diagnosis, the committee wrote.
The committee made the following recommendations for diagnosing IPF in all adult patients with newly detected interstitial lung disease (ILD) of unknown cause:
For all patients, a detailed history should be taken of both medication use and environmental exposures and serological testing should be performed to exclude connective tissue disease as a potential cause of the ILD.
For patients with a HRCT pattern of probable UIP, indeterminate, or an alternative diagnosis, conditional recommendations were made for performing bronchoalveolar lavage (BAL) and surgical lung biopsy (SLB); due to lack of evidence, no recommendation was made for or against performing transbronchial lung biopsy (TBBx) or lung cryobiopsy.
Conditional recommendation for MDD to aid in diagnosing IPF, particularly when the HRCT pattern has features of probable UIP pattern, indeterminate or alternative diagnosis.
In contrast, for patients with newly detected ILD who have a HRCT pattern of UIP, strong recommendations were made against performing SLB, TBBx and lung cryobiopsy; a conditional recommendation was made against performing BAL.
Strong recommendation against measurement of serum biomarkers for the sole purpose of distinguishing IPF from other ILDs.
"Our hope is that this new guideline will bridge the gap between the experienced IPF experts and general pulmonologists in making a prompt and accurate diagnosis of IPF for the individual unfortunately confronted with the disease," Dr. Raghu said. "This will allow patients to make well-informed decisions about treatment options and participation in clinical trials."

Researchers discover materials which form new presynapses for release of transmitters

Researchers discover materials which form new presynapses for release of transmitters



News-Medical

Researchers discover materials which form new presynapses for release of transmitters

Synapses are the interfaces for information exchange between neurons. Teams of scientists working with Professor Dr. Volker Haucke, Director at the Leibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP) and Professor at the Freie Universitaet Berlin, and Professor Dr. Stephan Sigrist at the Freie Universität Berlin discovered the materials, which form new presynapses for the release of transmitters. The findings may help to design better nerve-regenerating therapies in the future.
To date, we have a fairly good understanding how nerve cells (neurons) communicate with each other. Central in this information transfer is the release of neurotransmitters at chemical synapses. At synapses, signal-transmitting presynapses face postsynapses, which recognize the chemical signals and relay them. "By contrast, we still know relatively little as to how synapses are formed", points out Professor Volker Haucke.
The release of neurotransmitter at presynapses requires their storage synaptic vesicles (bubble-like structures). Furthermore, scaffold proteins have to be present at the right time and location to ensure proper transmitter release. Until now, it was unclear how synaptic vesicle components and scaffold proteins get to synaptic cell junctions. Moreover, it was unclear from which cellular building blocks scaffold proteins and vesicles are made. The teams of Professor Dr. Volker Haucke and Professor Dr. Stephan Sigrist studied neurons from mouse brain and Drosophila larvae to learn more about the processes forming presynapses. The results of their work have just been published in the prestigious journal Neuron on August 30, 2018. The scientists found answers to both questions: They discovered that for the most part, vesicle and scaffold proteins are co-transported to the presynapse in a packet (Figure 1). Hence, vesicle and scaffold proteins arrive at the nascent synapse as a preformed functional unit, so neurotransmitter release may start instantaneously. The scientists could also show that this mechanism is evolutionary conserved from flies to mice and probably humans. The team also revealed that scaffold and vesicle proteins are transported in organelles that share characteristics with so-called lysosomes. Professor Haucke explains: "This is extremely surprising as scientists used to believe that lysosomes are mostly responsible for the degradation of cell components. However, in the context of the developing nervous system, these lysosome-related vesicles appear to have a distinct assembly function as they are involved in forming the presynapses where transmitters are released."
These discoveries made by the scientists at the Leibniz-Forschungsinstitut für Molekulare Pharmakologie and the Freie Universitaet Berlin are of significance beyond basic research: For example, during learning processes synapses need to be remodelled to amplify signals. Professor Dr. Stephan Sigrist comments: "We were able to establish such a signal amplification in Drosophila larvae. When we programmed the neurons to deliver additional scaffold proteins and transport packets, they fired with more intensity than before." This correlation may prove useful in the treatment of congenital degenerative neuronal diseases or for the regeneration of neurons after major accidents for example. To enable injured people to walk again, nerve paths must regenerate and new synapses must form or be re-established. The described findings may allow to accelerate this process in a targeted fashion.

Neurons play active role in triggering a defense mechanism that leads to their own damage

Neurons play active role in triggering a defense mechanism that leads to their own damage

News-Medical

Neurons play active role in triggering a defense mechanism that leads to their own damage

Rasmussen's encephalitis is a rare autoimmune disease that primarily affects children and can lead to seizures. As the disease is resistant to drug treatments, it frequently requires surgical interventions aiming to remove or disconnect the affected part of the brain. Researchers from the University of Geneva (UNIGE) and the Geneva University Hospitals (HUG) have succeeded in describing and mastering the mechanisms at work within neurons in mice, opening the way to possible treatments. It was previously thought that neurons were the target of immune system cells that attack synapses, the connections between neurons. But researchers have discovered that the neurons themselves play an active role in triggering this process. Their research is published by Cell.
In Rasmussen encephalitis, like in other encephalitis, the presence of an antigen in the affected neurons triggers an immune system response, resulting in synaptic alterations. A team of researchers led by Doron Merkler, Associate Professor in the Department of Pathology and Immunology at the UNIGE Faculty of Medicine and senior consultant in the Clinical Pathology Service of the HUG, was able to show that neurons are not only passive victims of this attack, but play an essential role in triggering a defense mechanism that ultimately leads to their own damage. "Following the attack by CD8+ T lymphocytes of the immune system, which fight against viral infections, the neuron produces a chemical signal to other cells called phagocytes which then attack the synapses. It's a sort of tripartite tango with tragic consequences", explains Doron Merkler.
A double attack on the synapses
Triggered by the neuronal antigen, CD8+ T lymphocytes release a protein, IFN-γ, captured by corresponding neuronal receptor. Subsequently neurons activate the STAT 1 signaling pathway which leads to the production of a molecule called CCL2. The latter molecule diffuses into the neuronal environment where it activates other immune cell types called phagocytes: these are microglial cells present in the brain and macrophages derived from the blood circulation. These two types of phagocytes finally attack the synapses. &laquoIf we manage to cut off the signal emitted by the neuron, this whole cascade of causes and consequences could be blocked, stresses Giovanni Di Liberto, researcher in the Department of Pathology and Immunology at the UNIGE Faculty of Medicine and first author of the study.
A similar signaling signature could also be found in biopsies performed in more than 20 patients suffering from Rasmussen encephalitis, and researchers advocate that it is possibly identical for other forms of encephalitis. In mice experiments, this mechanism has been successfully blocked at different levels: The UNIGE and HUG teams have thus succeeded in blocking the signaling pathway of STAT1 and CCL2 molecules, as well as the migration and activation of phagocytes by pharmacological interventions and genetic manipulation, avoiding in all these cases the degradation of synapses and allowing for a better control of the disease.
Researchers will now have to partner to pursue the development of a possible treatment and conduct the necessary clinical trials, a difficult task when it comes to rare diseases. "But the principles we are describing are probably at work in other diseases that cause a strong immune response, and may even play a role in multiple sclerosis", says Merkler.