For Online E-newspaper
The East African : Dec 15th 2014
The EastAfrican 36 OUTLOOK DECEMBER 13-19,2014 S CI E N C E Rice powder best for treating cholera Using ≥ice sta≥ch instead of suga≥ with the ≥ehyd≥ation salts is mo≥e e≠ective in ≥educing its toxicity By CHRISTABEL LIGAMI Special Correspondent R ice could be a better option for treating cholera as opposed to the current oral rehydration method used, a new study shows. The main treatment for cholera involves oral rehydration therapy where the patient drinks water mixed with salts and glucose, which can increase the toxicity of the cholera bacterium. The study published in PLOS Journal for Neglected Tropical Diseases said using rice starch instead of sugar with the rehydration salts is more effective in reducing the toxicity of the cholera causing bacterium. The scientists from the Swiss Fed- eral Institute of Technology (EPFL) said that replacing glucose with rice powder can reduce its toxicity by almost 75 per cent. Their findings show that the cholera toxin increases when the bacterium is fed with glucose, but decreases considerably when fed with starch from rice. Since cholera infects the small in- testine, it often leads to diarrhoea and vomiting, resulting in dehydration and death. The normal treatment involves giving patients water mixed with salt and glucose in regular intervals. The idea is to replace the fluids and essential salts that patients lose, while the glucose acts as a source of carbon and helps the intestine to absorb the salts more efficiently. The patient continues the therapy until the infection has run its course. Although this treatment has proven to be effective, the EPFL HOW CHOLERA AFFECTS THE BODY Cholera is an acute intestinal infection that causes severe diarrhoea, dehydration and, if not treated promptly, death. How it spreads • People ingest water or food contaminated with cholera bacteria • In an epidemic, the faeces of diseased persons are the source of contamination Treatment • Salt solution, intravenous fluids, antibiotics Small intestine Large intestine Source: WHO scientists said that too much glucose intake is likely to increase the toxicity of the cholera bacterium by increasing the expression of its genes and thereby intensifying the disease further. The researchers therefore say that their new findings feed into the current discussion of cholera treatment. They strongly suggest a review of current approaches and the use of this modified model to include oral rehydration therapy based on rice starch instead of glucose as it will reduce cholera cases by 30 per cent. “Of course, we’re not saying ‘stop giving oral rehydration therapy with glucose right away’ because it works so well,” said Melanie Blokesch, the lead scientist from EPFL. “But still, the data suggests that the regimen can be significantly improved, and that the community needs to start discussing this possibility again — especially in areas endemic to cholera.” The cholera bacterium, Vibrio cholerae, infects humans by releasing a protein called the “cholera toxin.” Consequently, regulating the genes that produce the cholera toxin can either increase or decrease the bacterium’s capacity to spread disease. Melanie Blokesch and Andrea Rinaldo, researchers at EPFL, correlated data from a recent cholera “Of course, we’re not saying ‘stop giving oral rehydration therapy with glucose right away’...” Melanie Blokesch, EPFL scientist In the large intestine 1 Bacteria multiply rapidly outbreak in Haiti with the effectiveness of oral rehydration therapy. The scientists grew the chol- era bacterium with different sugars (glucose, sucrose) and starch from potatoes and rice to see how each would affect the cholera toxin genes. They found that both the activ- ity of the genes as well as the production of the cholera toxin itself were increased when the bacterium was fed with glucose, but they were considerably decreased when it was fed with starch from rice. “The reasons to this is that the 2 3 Toxin from bacteria penetrates cells of intestinal wall Toxin prevents the intestine from absorbing water from digested food; results in diarrhoea and dehydration type of sugar available (glucose, starch) to the bacterium affects the mechanisms that regulate the activity of its toxin-producing genes,” said the researchers. “Ultimately, this effect influences the bacterium’s ability to infect humans.” The scientists focused on match- ing the data to the actual cholera epidemic in Haiti. Using data from the outbreak of cholera that started in 2010 in the region, they developed a mathematical model of the disease’s epidemiology. They then modified the model to include oral rehydration therapy based on rice starch instead of glucose. The results showed that using this alternative approach could have a 30 per cent reduction of cholera cases (375,000 instead of 520,000 cases) on the island within the first 14 months of the epidemic. Up to half the number of chol- era patients would die without treatment, but oral rehydration therapy has been shown to lower the deaths to around one per cent. However, there are concerns that using glucose in the rehydration mixture can actually exacerbate the disease. The problem is that the infecting bacterium also consumes glucose, and that increases the expression of its genes, which make it toxic. Autism in child≥en linked to p≥e-eclampsia in the ute≥us By CHRISTABEL LIGAMI Special Correspondent CHILDREN WITH autism are more than twice as likely to have been exposed to pre-eclampsia while in the uterus, and the likelihood of the disorder is even greater if the mother suffered more severe diseases, a study published in JAMA Pediatrics shows. More than 1,000 children between the ages of two and three were enrolled in the Childhood Risks of Autism study. “We found significant associations between pre-eclampsia and autism spectrum disorders (ASD). We also observed a significant association between severe pre-eclampsia and developmental delay,” said Cheryl Walker, the study’s senior author While pre-eclampsia has previously been ex- amined as a risk factor for autism, the literature has been inconsistent. The current study provides a robust population-based, case-controlled examination of the association between autism and pre-eclampsia and whether risk was associ- A woman gets an ultra sound exam done. Pic: File ated with its severity. Women with pre-eclampsia experience hyper- tension during the latter half of their pregnancies, and may have increased levels of protein in their urine and oedema, or fluid retention. Pre-eclampsia can develop into eclampsia, a lifethreatening condition. The research was conducted in more than 500 boys and girls diagnosed with autism; nearly 200 diagnosed with developmental delay; and 350 children who were developing typically. All of the mothers had confirmed diagnoses of preeclampsia. It found that the mothers with autistic chil- dren were more than twice as likely to have had pregnancies complicated by pre-eclampsia. Mothers of children with autism and children with developmental delay were also significantly more likely to have had placental insufficiency, severe pre-eclampsia or both, when compared with mothers of children who were developing typically. The children with autism, whose mothers had pre-eclampsia, were also more likely to be cognitively lower functioning. The study also found a correlation between pre-eclampsia and developmental delay without autism, primarily in instances involving placental insufficiency. “While single studies cannot establish causality, the cumulative evidence supports efforts to reduce pre-eclampsia and diminish severity to improve neonatal outcomes,” said Dr Walker. BRIEFS HIV/Aids incidence in children down 40pc The incidence of HIV/Aids among children has declined by 40 per cent, and to this end, about 1.1 million children have been prevented from contracting the disease between 2009 and 2013, according to a United Nations International Children’s Education Fund (Unicef) report. “We must invest more in reaching every mother, newborn, child and every adolescent with HIV prevention and treatment programmes,” said Anthony Lake, executive director of Unicef. Bed nets more effective in malaria prevention Spraying insecticides indoors offers children no additional protection from malaria when bed nets are used, according to a study as malaria cases and deaths worldwide continue to fall. The study by the medical journal Lancet said donors should invest their limited resources in additional bed nets as the most cost-effective solution to tackling malaria, costing an average of $2.20 per person compared with $6.70 for insecticide. Mosquito nets offer better, more affordable protection. Pic: File Spine drug gives hope for repair after injury A drug that can encourage nerves in the spinal cord to grow and repair injuries has been developed by US scientists. The study on rats, published in the journal Nature, showed that some degree of movement and bladder control could be restored. The drug works by disrupting the “sticky glue” that prevents nerve cells from growing during an injury. Further tests still need to take place, but the charity Spinal Research said “real progress” was being made. Brain scans a must after stroke, doctors urged Patients should be given a brain scan after a stroke, even if it is a mini-stroke, say Canadian researchers writing in the journal Stroke. This is because images of the brain can help doctors assess the damage done and predict the risk of another stroke occurring. The researchers say that these findings should prompt physicians to be more aggressive in managing patients. Other measures to prevent further stroke are cardiac monitoring or medication to lower blood pressure, treat high cholesterol or prevent blood clots.
Dec 8th 2014
Dec 22nd 2014