How blood group O protects against malaria

18 05 2015

It has long been known that people with blood type O are protected from dying of severe malaria. In a study published in Nature Medicine, a team of Scandinavian scientists explains the mechanisms behind the protection that blood type O provides, and suggest that the selective pressure imposed by malaria may contribute to the variable global distribution of ABO blood groups in the human population.

Anopheles albimanus mosquito. Credit: James Gathany (Wikimedia Commons).

Malaria is a serious disease that is estimated by the WHO to infect 200 million people a year, 600,000 of whom, primarily children under five, fatally. Malaria, which is most endemic in sub-Saharan Africa, is caused by different kinds of parasites from the plasmodium family, and effectively all cases of severe or fatal malaria come from the species known as Plasmodium falciparum. In severe cases of the disease, the infected red blood cells adhere excessively in the microvasculature and block the blood flow, causing oxygen deficiency and tissue damage that can lead to coma, brain damage and, eventually death. Scientists have therefore been keen to learn more about how this species of parasite makes the infected red blood cells so sticky.

It has long been known that people with blood type O are protected against severe malaria, while those with other types, such as A, often fall into a coma and die. Unpacking the mechanisms behind this has been one of the main goals of malaria research.

A team of scientists led from Karolinska Institutet in Sweden have now identified a new and important piece of the puzzle by describing the key part played by the RIFIN protein. Using data from different kinds of experiment on cell cultures and animals, they show how the Plasmodium falciparum parasite secretes RIFIN, and how the protein makes its way to the surface of the blood cell, where it acts like glue. The team also demonstrates how it bonds strongly with the surface of type A blood cells, but only weakly to type O.

 

Conceptually simple

Principal investigator Mats Wahlgren, a Professor at Karolinska Institutet’s Department of Microbiology, Tumour and Cell Biology, describes the finding as “conceptually simple”. However, since RIFIN is found in many different variants, it has taken the research team a lot of time to isolate exactly which variant is responsible for this mechanism.

“Our study ties together previous findings”, said Professor Wahlgren. “We can explain the mechanism behind the protection that blood group O provides against severe malaria, which can, in turn, explain why the blood type is so common in the areas where malaria is common. In Nigeria, for instance, more than half of the population belongs to blood group O, which protects against malaria.”

The study was financed by grants from the Swedish Foundation for Strategic Research, the EU, the Swedish Research Council, the Torsten and Ragnar Söderberg Foundation, the Royal Swedish Academy of Sciences, and Karolinska Institutet. Except Karolinska Institutet, co-authors of the study are affiliated to Stockholm University, Lund University, Karolinska University Hospital, and the national research facility SciLifeLab in Sweden, and to the University of Copenhagen in Denmark and University of Helsinki in Finland. Mats Wahlgren is a shareholder and board member of drug company Dilaforette AB, which is working on an anti-malaria drug. The company was founded with support from Karolinska Development AB, which helps innovators with patent-protected discoveries reach the commercial market.

 

Publication

RIFINs are Adhesins Implicated in Severe Plasmodium falciparum Malaria

Suchi Goel, Mia Palmkvist, Kirsten Moll, Nicolas Joannin, Patricia Lara, Reetesh Akhouri, Nasim Moradi, Karin Öjemalm, Mattias Westman, Davide Angeletti, Hanna Kjellin, Janne Lehtiö, Ola Blixt, Lars Ideström, Carl G Gahmberg, Jill R Storry, Annika K. Hult, Martin L. Olsson, Gunnar von Heijne, IngMarie Nilsson and Mats Wahlgren

Nature Medicine, AOP 9 March 2015, doi: 10.1038/nm.3812

 

 

 

Ki.se [en línea] Solna (SUE): ki.se, 18 de mayo de 2015 [ref. 10 de marzo de 2015] Disponible en Internet: http://ki.se/en/news/how-blood-group-o-protects-against-malaria



Nueva combinación de fármacos orales eficaz contra el virus de la hepatitis C en pacientes con VIH

12 02 2015

Entre 130 y 150 millones de personas en el mundo están infectadas por el virus de la hepatitis C (VHC) y, de éstas, alrededor de 5 millones también lo están por el virus del VIH. Un estudio publicado en la prestigiosa revista The Lancet demuestra la eficacia en la curación del VHC en pacientes mono o coinfectados por VIH con el uso combinado de dos fármacos orales administrados durante 12 semanas. En este trabajo ha participado el Dr. Josep Mallolas, consultor del Servicio de Enfermedades Infecciosas del Hospital Clínic e Investigador del Grupo IDIBAPS Enfermedades Infecciosas y SIDA. El Clínic ha sido el único centro español que ha participado en este estudio.

Todos los pacientes con VHC, tanto mono infectados como coinfectados por el VIH, están en riesgo de presentar las complicaciones derivadas de la enfermedad y acabar requiriendo un trasplante de hígado. Además, en los pacientes con VIH la carga viral es más alta, la enfermedad progresa de una forma más rápida y hay menos opciones de tratamiento.

En este estudio multicéntrico internacional en fase II se administraron dos antivirales,grazoprevir y elbasvir, con o sin ribavirina, durante 8 o 12 semanas a 218 pacientes con hepatitis C no tratados previamente (159 con VHC y 59 coinfectados por VIH). El hecho de administrar este tratamiento de forma paralela a pacientes mono y coinfectados es innovador, ya que los pacientes con VIH suelen participar en ensayos clínicos independientes. Así, este estudio constituye una oportunidad única para determinar qué papel juega la infección por VIH en la respuesta a los tratamientos por el VHC.

Los resultados indican que la pauta terapéutica fue muy bien tolerada y, pasadas las 12 semanas, entre el 87 y el 98% de los participantes en el estudio presentaban una cantidad de RNA del virus de la hepatitis C inferior a 25 IU/ml, lo que indica una respuesta virológica sostenida o, lo que es lo mismo, curaron la hepatitis C. Esta respuesta fue similar tanto para los pacientes mono infectados como los coinfectados, lo que sugiere que esta combinación de fármacos proporciona una opción de tratamiento eficaz y segura para los dos grupos de pacientes.

Con estos prometedores resultados de curación de la hepatitis con tan sólo 12 semanas de tratamiento y con una tolerancia muy buena, ya se han puesto en marcha diferentes ensayos clínicos en fase III que evaluarán la eficacia de esta pauta terapéutica en un número mayor de pacientes.

Referencia del artículo:

Efficacy and safety of 8 weeks versus 12 weeks of treatment with grazoprevir (MK-5172) and elbasvir (MK-8742) with or without ribavirin in patients with hepatitis C virus genotype 1 mono-infection and HIV/hepatitis C virus co-infection (C-WORTHY): a randomised, open-label phase 2 trial

Sulkowski M, Hezode C, Gerstoft J, Vierling JM, Mallolas J, Pol S, Kugelmas M, Murillo A, Weis N, Nahass R, Shibolet O, Serfaty L, Bourliere M, DeJesus E, Zuckerman E, Dutko F, Shaughnessy M, Hwang P, Howe AY, Wahl J, Robertson M, Barr E, Haber B.

Lancet. 2014 Nov 11. pii: S0140-6736(14)61793-1. doi: 10.1016/S0140-6736(14)61793-1. [Epub ahead of print]

 

Hubc.ub.edu [en línea] Barcelona (ESP): aip.org, 12 de febrero de 2015 [ref. 20 de enero de 2015] Disponible en Internet: http://hubc.ub.edu/es/el-hubc/actualidad/noticias/una-nueva-combinacion-de-farmacos-orales-demuestra-su-eficacia-contra-el



Podoconiosis una enfermedad olvidada. Experiencia en Etiopía.

5 02 2015
Laura Prieto estuvo en las III Jornadas de Cooperación al Desarrollo y en Salud de la Universidad Miguel Hernández de Elche hablando de la podoconiosis y su experiencia en Etiopía en el mes de mazo del 2014
Dicha ponencia se ha grabado y editado gracias a los servicios de innovación docente de la UMH, dentro del PLAN  DIVULGA de la UMH.
Imagen de previsualización de YouTube
Ha sido un magnifico trabajo de todos
Gracias
José Manuel Ramos
Posted by 
Información acerca del voluntariado en Hospital de Gambo: http://www.gambohospital.org/voluntariado/
 
 
Gambohospital.org [en línea] Arsi (ETH): gambohospital.org, 05 de febrero de 2015 [ref. 25 de noviembre de 2014] Disponible en Internet: http://www.gambohospital.org/blog/podoconiosis-una-enfermedad-olvidada-experiencia-en-etiopia/



Wireless Electronic Implants Stop Staph, Then Harmlessly Dissolve

29 01 2015

Researchers at Tufts University, in collaboration with a team at the University of Illinois at Champaign-Urbana, have demonstrated a resorbable electronic implant that eliminated bacterial infection in mice by delivering heat to infected tissue when triggered by a remote wireless signal.  The silk and magnesium devices then harmlessly dissolved in the test animals. The technique had previously been demonstrated only in vitro. The research is published online in the Proceedings of the National Academy of Sciences Early Edition the week of November 24-28, 2014.

“This is an important demonstration step forward for the development of  on-demand medical devices that can be turned on remotely to perform a therapeutic function in a patient and then safely disappear after their use, requiring no retrieval,” said senior author Fiorenzo Omenetto, professor of biomedical engineering and Frank C. Doble professor at Tufts School of Engineering. “These wireless strategies could help manage post-surgical infection, for example, or pave the way for eventual ‘wi-fi’ drug delivery.”

Implantable medical devices typically use non-degradable materials that have limited operational lifetimes and must eventually be removed or replaced. The new wireless therapy devices are robust enough to survive mechanical handling during surgery but designed to harmlessly dissolve within minutes or weeks depending on how the silk protein was processed, noted the paper’s first author, Hu Tao, Ph.D., a former Tufts post-doctoral associate who is now on the faculty of the Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences.

Each fully dissolvable wireless heating device consisted of a serpentine resistor and a power-receiving coil made of magnesium deposited onto a silk protein layer. The magnesium heater was encapsulated in a silk “pocket” that protected the electronics and controlled its dissolution time.

Devices were implanted in vivo in S. aureus infected tissue and activated by a wireless transmitter for two sets of 10-minute heat treatments. Tissue collected from the mice 24 hours after treatment showed no sign of infection, and surrounding tissues were found to be normal. Devices completely dissolved after 15 days, and magnesium levels at the implant site and surrounding areas were comparable to levels typically found in the body.

The researchers also conducted in vitro experiments in which similar remotely controlled devices released the antibiotic ampicillin to kill E. coli and S. aureus bacteria. The wireless activation of the devices was found to enhance antibiotic release without reducing antibiotic activity.

Omenetto holds an adjunct appointment in the Department of Physics in the School of Arts and Sciences at Tufts as well as appointments in the Departments of Biomedical Engineering and Chemical and Biological Engineering in the School of Engineering.

In addition to Omenetto and Tao, authors on the paper were co-first author Suk-Won Hwang, formerly of the Department of Materials Science and Engineering, Beckman Institute for Advanced Science and Technology, and Frederick Seitz Materials Research Laboratory, University of Illinois at Urbana-Champaign, and now at KU-KIST Graduate School of Converging Science and Technology, Korea University; Benedetto Marelli, Bo An, Jodie E. Moreau, Miaomiao Yang, and Mark A. Brenckle, Department of Biomedical Engineering, Tufts University; Stanley Kim, Department of Materials Science and Engineering, Beckman Institute for Advanced Science and Technology, and Frederick Seitz Materials Research Laboratory, University of Illinois at Urbana-Champaign; David L. Kaplan, Department of Biomedical Engineering and Department of Chemical and Biomedical Engineering, Tufts University; and co-corresponding author John A. Rogers, Department of Materials Science and Engineering, Beckman Institute for Advanced Science and Technology, Frederick Seitz Materials Research Laboratory, Department of Chemistry, and Department of Electrical and Computer Engineering, University of Illinois at Urbana-Champaign.

Research reported in this paper was supported by the National Institutes of Health under award number P41-EB002520 and by the National Science Foundation under grant number DMR-1242240.

“Silk-based resorbable electronic devices for remotely controlled therapy and in vivo infection abatement,” http://www.pnas.org/cgi/doi/10.1073/pnas.1407743111

Located on Tufts’ Medford/Somerville campus, Tufts’ School of Engineering offers a rigorous engineering education in a unique environment that blends the intellectual and technological resources of a world-class research university with the strengths of a top-ranked liberal arts college. Close partnerships with Tufts’ excellent undergraduate, graduate and professional schools, coupled with a long tradition of collaboration, provide a strong platform for interdisciplinary education and scholarship. The School of Engineering’s mission  is to educate engineers committed to the innovative and ethical application of science and technology in addressing the most pressing societal needs, to develop and nurture twenty-first century leadership qualities in its students, faculty, and alumni, and to create and disseminate transformational new knowledge and technologies that further the well-being and sustainability of society in such cross-cutting areas as human health, environmental sustainability, alternative energy, and the human-technology interface.

 

 

Now.tufts.edu [en línea] Boston, MA (USA): now.tufts.edu, 29 de enero de 2015 [ref. 24 de noviembre de 2014] Disponible en Internet: http://now.tufts.edu/news-releases/wireless-electronic-implants-stop-staph-then-harmlessly-dissolve



Liposomes: a possible alternative to antibiotics

5 01 2015

Scientists from the University of Bern have developed a novel substance for the treatment of severe bacterial infections without antibiotics, which would prevent the development of antibiotic resistance.

 

Credit: Eric Erbe, Christopher Pooley, Wikipedia

Ever since the development of penicillin almost 90 years ago, antibiotics have remained the gold standard in the treatment of bacterial infections. However, the WHO has repeatedly warned of a growing emergence of bacteria that develop antibiotic resistance. Once antibiotics do no longer protect from bacterial infection, a mere pneumonia might be fatal.

Alternative therapeutic concepts which lead to the elimination of bacteria, but do not promote resistance are still lacking.

A team of international scientists has tested a novel substance, which has been developed by Eduard Babiychuk and Annette Draeger from the Institute of Anatomy, University of Bern in Switzerland. This compound constitutes a novel approach for the treatment of bacterial infections: the scientists engineered artificial nanoparticles made of lipids, “liposomes” that closely resemble the membrane of host cells. These liposomes act as decoys for bacterial toxins and so are able to sequester and neutralize them. Without toxins, the bacteria are rendered defenseless and can be eliminated by the cells of the host’s own immune system. The study will be published in Nature Biotechnology Nov 2.

 

Artificial bait for bacterial toxins

In clinical medicine, liposomes are used to deliver specific medication into the body of patients. Here, the Bernese scientists have created liposomes which attract bacterial toxins and so protect host cells from a dangerous toxin attack.

“We have made an irresistible bait for bacterial toxins. The toxins are fatally attracted to the liposomes, and once they are attached, they can be eliminated easily without danger for the host cells”, says Eduard Babiychuk who directed the study.

“Since the bacteria are not targeted directly, the liposomes do not promote the development of bacterial resistance”, adds Annette Draeger. Mice which were treated with the liposomes after experimental, fatal septicemia survived without additional antibiotic therapy.

 

Explore further: Old drug may be key to new antibiotics

More information: Brian D. Henry, Daniel R. Neill, Katrin Anne Becker, Suzanna Gore, Laura Bricio-Moreno, Regan Ziobro, Michael J. Edwards, Kathrin Mühlemann, Jörg Steinmann, Burkhard Kleuser, Lukasz Japtok, Miriam Luginbühl, Heidi Wolfmeier, André Scherag, Erich Gulbins, Aras Kadioglu, Annette Draeger & Eduard B. Babiychuk: “Engineered liposomes sequester bacterial exotoxins and protect from severe invasive infections in mice,” Nature Biotechnology, 2.11.2014, DOI: 10.1038/nbt.3037

Journal reference: Nature Biotechnology

Provided by University of Bern

 

 

Phys.org [en línea] Douglas, Isle of Man (UK): phys.org, 05 de enero de 2015 [ref. 04 de noviembre de 2014] Disponible en Internet: http://phys.org/news/2014-11-alternative-antibiotics.html



Typhoid gene unravelled

20 11 2014

People who carry a particular type of gene have natural resistance against typhoid fever according to new research published in Nature Genetics.

Lead researcher, Dr Sarah Dunstan from the Nossal Institute of Global Health at the University of Melbourne said the study is the first large-scale, unbiased search for human genes that affect a person’s risk of typhoid.

Typhoid is a health burden to lower income countries- www.ecofriend.com

Enteric fever, or typhoid fever as it more commonly known, is a considerable health burden to lower-income countries.

This finding is important because this natural resistance represents one of the largest human gene effects on an infectious disease.

“We screened the human genome to look for genes associated with susceptibility to, or resistance from typhoid.,” Dr Dunstan said.

“We found that carrying a particular form of the HLA-DRB1 gene provides natural resistance against typhoid fever.  This gene codes for a receptor that is important in the immune response, by recognising proteins from invading bacteria.”

Typhoid is contracted, by consuming food or water contaminated with the bacteria, Salmonella Typhi or Paratyphi. It has been estimated that typhoid causes 200,000 deaths a year globally, and infects 26.9 million people per year.

“If we can understand this natural mechanism of disease resistance, then we can use this knowledge to help develop improved vaccines for typhoid fever, but also potentially for other invasive bacterial disease,”

Better treatments and vaccines are needed for typhoid fever as the infecting bacteria are getting increasingly more resistant to antibiotic treatment, and the current vaccine is only moderately effective and does not protect against paratyphoid fever, which is increasing within Asia.

This work was conducted in patients from Vietnam with findings then replicated in independent patient cohorts from Vietnam and Nepal

The research collaboration was between the Genome Institute of Singapore and Oxford University Clinical Research Units in Vietnam and Nepal.

 

 

Newsroom.melbourne.edu [en línea] Melbourne (AUS): newsroom.melbourne.edu, 20 de noviembre de 2014 [ref. 10 de noviembre de 2014] Disponible en Internet: http://newsroom.melbourne.edu/news/typhoid-gene-unravelled



Why live vaccines may be most effective for preventing Salmonella infections

9 10 2014

Vaccines against Salmonella that use a live, but weakened, form of the bacteria are more effective than those that use only dead fragments because of the particular way in which they stimulate the immune system, according to research from the University of Cambridge published today.

 

The BBSRC-funded researchers used a new technique that they have developed where several populations of bacteria, each of which has been individually tagged with a unique DNA sequence, are administered to the same host (in this case, a mouse). This allows the researchers to track how each bacterial population replicates and spreads between organs or is killed by the immune system. Combined with mathematical modelling, this provides a powerful tool to study infections within the host. The findings are published today in the journal PLOS Pathogens

 

“We effectively ‘barcode’ the bacteria so that we can see where in the body they go and how they fare against the immune system,” explains Dr Pietro Mastroeni from the Department of Veterinary Medicine at the University of Cambridge, who led the study. “This has provided us with some important insights into why some vaccines are more effective than others.”

 

The multidisciplinary research team led by Dr Mastroeni used the new technique to look at the effectiveness of vaccines against infection by the bacterium Salmonella enterica, which causes diseases including typhoid fever, non-typhoidal septicaemia and gastroenteritis in humans and animals world-wide. Current measures to control S. enterica infections are limited and the emergence of multi-drug resistant strains has reduced the usefulness of many antibiotics. Vaccination remains the most feasible means to counteract S. enterica infections.

 

There are two main classes of vaccine: live attenuated vaccines and non-living vaccines. Live attenuated vaccines use a weakened form of the bacteria or virus to stimulate an immune response – however, there are some concerns that the weakened pathogen may become more virulent when used in patients with compromised immune systems, for example people infected with HIV, malaria or TB. Non-living vaccines, on the other hand, are safer as they usually use inactive bacteria or viruses, or their fragments – but these vaccines are often less effective. Both vaccines work by stimulating the immune system to recognise a particular bacterium or virus and initiate the fight back in the event of future infection.

 

Using their new technique, Dr Mastroeni and colleagues showed that live Salmonella vaccines enhance the ability of the immune system to prevent the bacteria from replicating and spreading to other organs. They can also prevent the spread of the bacteria into the bloodstream, which causes a condition known as bacteraemia, a major killer of children in Africa.

 

They also found that the antibody response induced by live vaccines enhances the ability of immune cells known as phagocytes to kill bacteria in the very early stages of infection, but that a further type of immune cell known as the T-cell – again stimulated by the live vaccine – is subsequently necessary for control and clearance of the bacteria from the blood and tissues. The killed vaccine, whilst able to boost the phagocyte response via the production of antibodies, did not stimulate a protective form of T-cell immunity and was unable to prevent the subsequent bacterial growth in infected organs or the development of bacteraemia, and was unable to control the spread of the bacteria in the body.

 

Dr Chris Coward, first author on the study, says: “We have used a collaboration between experimental science and mathematical modelling to examine how vaccines help the immune system control infection. We found that, for Salmonella infections, the immune response induced by a killed vaccine initially kills a proportion of the invading bacteria but the surviving bacteria then replicate resulting in disease. The live vaccine appears superior because it induces a response that both kills the bacteria and restrains their growth, leading to elimination of the infection.”

 

Dr Mastroeni adds: “There is a big push towards the use of non-living vaccines, which are safer, particularly in people with compromised immune systems – and many of the infections such as Salmonella are more prevalent and dangerous in countries blighted by diseases such as HIV, malaria and TB. But our research shows that non-living vaccines against Salmonella may be of limited use only and are not as effective as live vaccines. Therefore more efforts are needed to improve the formulation and delivery of non-living vaccines if these are to be broadly and effectively used to combat systemic bacterial infections. We have used Salmonella infections as a model, but our research approaches can be extended to many pathogens of humans and domestic animals.”

 

The research was carried out Dr Mastroeni, Dr Coward and colleagues Dr Andrew Grant, Dr Oliver Restif, Dr Richard Dybowski and Professor Duncan Maskell. It was funded by the Biotechnology and Biological Sciences Research Council, which has recently awarded Dr Mastroeni funding  to extend this research to the study of how antibiotics work. The new research aims to optimise treatments and reduce the appearance of antibiotic resistance.

 

Professor Melanie Welham, BBSRC’s Science Director, said: “To protect our health and the health of animals we rely on, such as livestock, effective vaccines are needed against disease. This new technique provides unique insights that will help us compare vaccines produced in different ways to ensure the best disease prevention strategies.”

 

Reference

Coward, C et al. The Effects of Vaccination and Immunity on Bacterial Infection Dynamics In Vivo. PLOS Pathogens; 18 Sept 2014

 

 

Cam.ac.uk [en línea] Cambridge (UK): cam.ac.uk, 09 de octubre de 2014 [ref. 18 de septiembre de 2014] Disponible en Internet: http://www.cam.ac.uk/research/news/why-live-vaccines-may-be-most-effective-for-preventing-salmonella-infections



Technique for early and rapid malaria diagnosis

29 09 2014

Low-cost field detection system can detect malaria infection within minutes with just a drop of blood

 

Red blood cells from a patient infected with Plasmodium falciparum.
Credit: Osaro Erhabor

 A team of Singapore scientists have invented a new technique to detect malaria within minutes and all that is required is a drop of blood.

Malaria is a mosquito-borne parasite which affects over 60 million people worldwide and could be fatal in serious cases. It is still a huge problem in developing countries because there is no vaccine for malaria while antimalarial drugs are losing their efficacy with increasing drug resistance on the rise.

 

The research entitled ‘Micromagnetic Resonance Relaxometry for rapid label-free malaria diagnosis’ was published online on 31 Aug 2014 in the prestigious scientific journal Nature Medicine. This innovative technique is developed by the Singapore-MIT Alliance for Research and Technology (SMART) [新加坡-麻省理工学院科研中心] in collaboration with Nanyang Technological University (NTU).

With this disruptive new technology, hospitals may soon have the ability to rapidly screen and monitor hundreds of patients at the point-of-care for malaria, at much lower cost per patient.

Despite technological advances, currently malaria infection is still detected via stained blood smear microscopy. Lab technician will need to spot the tiny parasitized red blood cells among millions of healthy uninfected red blood cells, especially in the case of early infection, which is like finding a needle in a haystack. It is not only time-consuming and labour-intensive but also often not conclusive as it is highly dependent on the subjective judgement of the microscopist. Therefore, a false-positive call is not unusual.

Other malaria diagnostic techniques such as the Polymerase Chain Reaction (PCR) also have limitations as it is not field-deployable and can only provide semi-quantitative analysis.

 

SMART new technique

The solution developed by the SMART team since 2010, works by detecting the biomarker hemozoin crystallites, the metabolic waste product of malaria parasites during the intra-erythrocytic* cycle As the technique uses miniaturized Magnetic Resonance Relaxometry (MRR) system, a cousin of Magnetic Resonance Imaging (MRI), it is also more sensitive, accurate and faster than traditional methods.

The technique detects malaria infections at a very early stage, even when the amount of parasites in the blood is extremely low. It was successfully proven in mouse studies, where the presence of malaria parasites was detected at the very next day of infection. Moving forward the team is currently working on human study at clinical settings.

At the onset of malaria, the malaria parasites “eat up” large amount of haemoglobin^ and converts them into hemozoin crystallites. These crystallites are basically oxidized iron nanoparticles (Fe3+), making them way more “magnetic” than the healthy red blood cells, which can be easily picked up by the miniaturized MRR developed by SMART.

 

Professor Han Jongyoon, Principal Investigator from SMART’s BioSystems and Micromechanics (BioSyM) Interdisciplinary Research Group (IRG), said: “This system is more reliable and allows for rapid screening to be conducted. So, given the flux of people moving in and out of developed nations especially, this system has the potential to help prevent mass import of malaria by infected persons. For developing nations, this system, which does not require refrigeration or other extensive infrastructure, is portable enough to be deployed in rural areas, to help rapidly screen for malaria and hence stem the spread of this infectious disease.”

Professor Peter Preiser, SMART co-Investigator and Chair of NTU’s School of Biological Sciences said that the new test has the additional potential to rapidly detect parasites that are resistant to anti-malarial drugs particularly artemisinin thereby providing a valuable tool in trying to prevent the global spread of these resistant parasites.

“Importantly, rapid and accurate diagnosis will reduce the prescription of drugs to non-infected people – one factor that contributes to why we are seeing more malaria parasites developing resistance to anti-malarial drugs,” said Prof Preiser, a renowned expert in malaria.

“With a more accurate and sensitive detection system like the one we developed, doctors can better diagnose malaria infections in patients. We need to ensure that drug resistance is kept to the minimum because these drugs are really our last line of defence in helping malaria-stricken patients.”

 

SMART Research Scientist Dr Brian Peng Weng Kung and lead author of the paper, added: “The significant part of this research lies in the fact that this system is practically a “mini MRI” system that is much cheaper to produce than the million-dollar MRI machines used by hospitals. We built tiny radiofrequency (rf) coil which is used to apply rf-pulses and receive signal from a drop of blood, and the whole detection process happens in a few minutes. Furthermore, since this technique does not rely on immuno-assay# labelling that requires expensive chemical reagents, we are able to bring down the screening test cost to less than S$0.10 per test.”

SMART is now spinning off a company to commercialise this technology, which could also work for other types of blood disorders. Moving forward, the research team is also setting up field-tests in the South-East Asia region. They are testing if the system can be run on solar power, which will be useful in rural areas, where electricity is scarce. This research is funded by the Singapore National Research Foundation, Prime Minister’s Office, Singapore under its Campus for Research Excellence And Technological Enterprise (CREATE) programme.

*Intra-erythrocytic: Occurring within the red blood cells
^Haemoglobin: A protein in red blood cells that carries oxygen
#Immunoassay: A test that uses antibody and antigen complexes as a means of generating a measurable result 

 

Smart.mit.edu [en línea] Memphis, TN (USA): smart.mit.edu, 29 de septiembre de 2014 [ref. 02 de septiembre de 2014] Disponible en Internet: http://smart.mit.edu/news-a-events/press-room/article/49-scientists-in-singapore-develop-groundbreaking-technique-for-early-and-rapid-malaria-diagnosis.html



La heparina muestra una doble actividad contra la malaria

31 07 2014

Una investigación publicada en Nanomedicine y llevada a cabo por científicos del IBEC, ISGlobal y la UB abre la puerta a mejorar el tratamiento de la malaria mediante heparina.

 

El estudio publicado en Nanomedicine explora si la heparina, que ha mostrado tener actividad contra la malaria y afinidad de unión específica para los glóbulos rojos infectados por Plasmodium falciparum frente a los glóbulos no infectados, puede mostrar ambas propiedades y unirlas en una estrategia de administración de fármacos contra la malaria. En este caso la heparina tendría un doble papel como antimalárico y como elemento de focalización de las nanopartículas cargadas con fármacos que actuarían al unirse a los glóbulos rojos infectados. Este estudio, llevado a cabo por investigadores del CRESIB, centro de investigación del Instituto de Bioingeniería de Catalunya (IBEC), de ISGlobal y de la Universitat de Barcelona, ha sido publicado en Nanomedicine.

 

La heparina adsorbida electrostáticamente sobre los liposomas con carga positiva y cargados con primaquina, medicamento antimalárico, fue capaz de triplicar la actividad en cultivos de P. falciparum del fármaco encapsulado. En concentraciones inferiores a las que inducen anticoagulación de la sangre de ratón in vivo, la actividad parasiticida resultó ser la suma de las actividades separadas de heparina libre como antimalárico y de heparina unida al liposoma como elemento vectorizador para la primaquina encapsulada.

 

Los investigadores observaron mediante imágenes de fluorescencia confocal y de microscopía electrónica que al cabo de 30 minutos de haber tratado glóbulos rojos infectados por Plasmodium con heparina, ésta había penetrado los parásitos intracelulares.

 

Xavier Fernández-Busquets, investigador IBEC e ISGlobal y coordinador del estudio, comenta que “estos resultados abren la puerta a mejorar el tratamiento con heparina contra la malaria debido a su actividad aditiva como fármaco y como elemento vectorizador específico de otros antimaláricos; sin embargo, será necesario realizar más investigación a nivel clínico para comprobar el papel de la heparina en pacientes infectados por Plasmodium”.

 

Referencia del artículo: Marques J, Moles E, Urbán P, Prohens R, Busquets MA, Sevrin C, Grandfils C, Fernàndez-Busquets X. (2014). “Application of heparin as a dual agent with antimalarial and liposome targeting activities towards Plasmodium-infected red blood cells.” Nanomedicine, epub ahead of print

ibecbarcelona.eu [en línea] Barcelona (ESP): ibecbarcelona.eu, 28 de julio de 2014 [ref. 31 de julio de 2014] Disponible en Internet: http://www.ibecbarcelona.eu/NOTICIAS-DE-INVESTIGACION/heparin-exhibits-dual-activity-against-malaria.html



La presencia de hepatitis afecta a la producción de insulina

28 07 2014

La presencia de hepatitis afecta a la producción de insulina, advierte un experto.

Un especialista del IMSS expone que un alto porcentaje de los casos cursan sin síntomas evidentes, por lo que recomienda realizar estudios de manera periódica

El ataque de virus al hígado propicia que se inflame y endurezca (hepatitis) y no realice algunas de sus funciones principales, entre ellas la participación en la producción de insulina en conjunto con el páncreas. La falta de esta hormona disparará los niveles de glucosa en sangre, al grado de catalogar al afectado como paciente diabético.

 

Lo anterior fue explicado por el doctor Paulo López Guillén, titular de la Clínica de Infectología Juan I. Menchaca del IMSS en Jalisco. Añadió que los virus que derivan en hepatitis B y C son aún más perjudiciales, ya que tienden a hacer la enfermedad crónica y dañar al hígado paulatinamente.

 

El especialista advirtió que en alto porcentaje la hepatitis cursa sin síntomas evidentes, por lo cual es importante la realización periódica de estudios de laboratorio.

 

“La mayoría de las personas infectadas cursa con una hepatitis que no van a generar un daño hepático agudo como para que tengamos un cuadro clínico de ictericia o coloración amarillenta en la piel y en la parte blanca de los ojos (esclera)”, refiere el infectólogo.

 

Recomendó especialmente las evaluaciones periódicas a las personas que hayan recibido transfusiones sanguíneas antes de 1986, así como quienes tengan piercings y tatuajes, o incluso aquellos adictos a drogas intravenosas, porque el virus C de la hepatitis se concentra en la sangre.

 

Una vez que el virus C de la hepatitis ingresa al organismo, “en el 95 por ciento de los casos se queda y puede pasar mucho tiempo antes de que se exprese, de ahí que se le considere crónico; en el cinco por ciento restante, las personas que entran en contacto con el microorganismo forman anticuerpos que impiden al virus instalarse en el hígado y por lo tanto “no quedan ni como portadores ni mucho menos llegan a enfermar”, puntualizó el especialista.

 

Sobre la forma de contagio de la hepatitis B, el médico dijo su mecanismo de transmisión es muy similar al del VIH e incluye la vía sexual y la sanguínea, de manera que es sumamente riesgosa.

 

El médico familiar a través de un análisis de la sangre (biometría hemática) puede identificar disminución en plaquetas, aumento en glóbulos blancos y anemia, lo cual debe hacerle sospechar de presencia de hepatitis; asimismo, es importante que se haga una prueba de la función hepática, esto también mediante un análisis de las enzimas del hígado, las transaminasas concretamente, las cuales tienden a elevarse como manifestación de problemas, en este importante órgano.

 

Debido a que usa como transporte la sangre, la glucosa entra en contacto con prácticamente todos los órganos del cuerpo, de manera que es de vital importancia realizarse periódicas evaluaciones para mantener todo bajo control, sobre todo si se han identificado algunos riesgos de contagio.

 

 

Dicyt.com [en línea] Salamanca (ESP): dicyt.com, 28 de julio de 2014 [ref. 21 de julio de 2014] Disponible en Internet:

http://www.dicyt.com/noticias/la-presencia-de-hepatitis-afecta-a-la-produccion-de-insulina-advierte-un-experto