To what extent can traditional medicine contribute a complementary or alternative solution to malaria control programmes?

Recent studies on traditional medicine (TM) have begun to change perspectives on TM effects and its role in the health of various populations. The safety and effectiveness of some TMs have been studied, paving the way to better collaboration between modern and traditional systems. Traditional medicines still remain a largely untapped health resource: they are not only sources of new leads for drug discoveries, but can also provide lessons and novel approaches that may have direct public-health and economic impact. To optimize such impact, several interventions have been suggested, including recognition of TM's economic and medical worth at academic and health policy levels; establishing working relationships with those prescribing TM; providing evidence for safety and effectiveness of local TM through appropriate studies with malaria patients; spreading results for clinical recommendations and health policy development; implementing and evaluating results of new health policies that officially integrate TM.     

To what extent can traditional medicine contribute a complementary or alternative solution to malaria control programmes?

Background

Sulphadoxine and pyrimethamine are anti-folate drugs that show synergistic anti-malarial effect. Point mutations in dihydrofolate reductase (dhfr) and dihydropteorate synthatase (dhps) cause anti-folate drug resistance phenotype in human malaria parasites. This study presents pattern of point mutations in dhfr/dhps genes among Indian sub-continent.

Methods

Microscopically diagnosed one hundred Plasmodium vivax field isolates were collected from five widely separated geographical regions of India. Dhfr and dhps genes were PCR amplified and sequenced. Previously published mutations data were collected and analyzed using Chi square test to identify geographical cluster of mutant/wild type genotypes.

Results

Sequence analysis revealed single (S58R), double (S58R/S117N) and quadruple (F57L/S58R/T61M/S117T/) point mutations at dhfr and single (A383G) to double (A383G/A553G) mutations at dhps in P. vivax field isolates. In addition, three new mutations were also observed at dhfr. Both, dhfr and dhps genes revealed tandem repeat variations in field isolates. Dhps revealed very low mutation frequency (14.0%) compared to dhfr (50.70%). Comparative analysis revealed a progressive increase in frequency of quadruple mutant dhfr genotype (p < 0.001) within five years in north-eastern state (Kamrup, Assam). Frequency of dhfr genotypes revealed three distinct geographical clusters of wild (northern India), double mutant (southern India), and quadruple mutant (north-eastern and island regions of India) on the Indian sub-continent.

Conclusion

Study suggests that SP may be susceptible to P. vivax in India, except Andaman and north-eastern state. The distinction of geographical regions with sensitive and resistant parasite phenotypes would be highly useful for designing and administering national anti-malarial drug policy.     

Plant secondary compounds as complementary resources: are they always complementary?

Generalist herbivores typically grow better on mixed- than on single-component diets. This response has been attributed to food complementarities that either enhance the utilization of nutrients or dilute the negative impacts of plant secondary compounds (PSC). For instance, when animals choose between foods that contain diverse PSC, they eat more than animals offered a food that contains just one PSC. In addition to their negative impacts on herbivore fitness, recent evidence suggests that at appropriate doses PSC may provide beneficial effects to herbivores (i.e., by reducing parasitic infections). Thus, complementarities among diverse PSC may not only influence an herbivore’s ability to consume food but also reduce the incidence of disease. We assessed the complementary effects of two PSC by offering sheep (Ovis aries) a choice of foods containing condensed tannins and saponins while challenged with a parasitic (Haemonchus contortus) infection. Animals offered a choice ate more than animals just offered tannins or saponins in single rations. However, sheep offered choices displayed greater fecal egg counts (an indirect measurement of parasitic burdens) than sheep offered single rations. Thus, saponin- and tannin-containing foods were complementary resources regarding nutrient intake but antagonistic regarding effects on parasitic loads. The nature of the relationship among PSC may depend on the dimension (i.e., nutrient intake, disease) where the interaction occurs. A unifying currency such as growth or reproductive output may help understand the trade-offs between costs (disease) and benefits (nutrient and medicine intake) for herbivores grazing multiple PSC.     

Evidence-based alternative medicine?

The validity of evidence-based medicine (EBM) is the subject of ongoing controversy. The EBM movement has proposed a "hierarchy of evidence," according to which randomized controlled trials (RCTs) and meta-analyses of RCTs provide the most reliable evidence concerning the efficacy of medical interventions. The evaluation of alternative medicine therapies highlights problems with the EBM hierarchy. Alternative medical researchers-like those in mainstream medicine-wish to evaluate their therapies using methods that are rigorous and that are consistent with their philosophies of medicine and healing. These investigators have three ways to relate their work to EBM. They can accept the EBM hierarchy and carry out RCTs when possible; they can accept the EBM standards but argue that the special characteristics of alternative medicine warrant the acceptance of "lower" forms of evidence; or they can challenge the EBM approach and work to develop new research designs and new standards of evidence that reflect their approach to medical care. For several reasons, this last option is preferable. First, it will best meet the needs of alternative medicine practitioners. Moreover, because similar problems beset the evaluation of mainstream medical therapies, reevaluation of standards of evidence will benefit everyone in the medical community--including, most importantly, patients.     

Why are complementary DNA strands symmetric?

MOTIVATION: Over sufficiently long windows, complementary strands of DNA tend to have the same base composition. A few reports have indicated that this first-order parity rule extends at higher orders to oligonucleotide composition, at least in some organisms or taxa. However, the scientific literature falls short of providing a comprehensive study of reverse-complement symmetry at multiple orders and across the kingdom of life. It also lacks a characterization of this symmetry and a convincing explanation or clarification of its origin. RESULTS: We develop methods to measure and characterize symmetry at multiple orders, and analyze a wide set of genomes, encompassing single- and double-stranded RNA and DNA viruses, bacteria, archae, mitochondria, and eukaryota. We quantify symmetry at orders 1 to 9 for contiguous sequences and pools of coding and non-coding upstream regions, compare the observed symmetry levels to those predicted by simple statistical models, and factor out the effect of lower-order distributions. We establish the universality and variability range of first-order strand symmetry, as well as of its higher-order extensions, and demonstrate the existence of genuine high-order symmetric constraints. We show that ubiquitous reverse-complement symmetry does not result from a single cause, such as point mutation or recombination, but rather emerges from the combined effects of a wide spectrum of mechanisms operating at multiple orders and length scales.     

RNA complementary to α-amylase mRNA in barley

Two experimental approaches demonstrate that different types of RNA complementary to -amylase mRNA are present in barley. S1 nuclease assays identify an RNA that is complementary to essentially the full length of both the type A and type B -amylase mRNAs. Complementarity, however, is imperfect: the S1 nuclease-resistant products can only be identified if they are electrophoresed as RNA-DNA hybrids. This RNA is present in developing endosperm + aleurone tissue and in mature aleurone tissue cultured in the absence of hormonal treatment or in the presence of abscisic acid, but not in shoot or root tissue. In mature aleurone tissue treated with abscisic acid, its steady-state abundance is similar to that of -amylase mRNA. Northern blot analysis indicated the presence of a second type of antisense RNA. Under conditions of moderate stringency, antisense-specific probes detect discrete hybridizing species of 1.6, 1.4, and 1.0 kilobases in mature aleurone and shoot tissues that do not represent spurious hybridization to rRNA, -amylase mRNA, or the abundant, G+C-rich mRNA for a probable amylase/protease inhibitor. The different results are consistent with the fact that the hybridization assay can tolerate relatively short regions of complementarity separated by large, nonhomologous sequences, while the nuclease protection assay cannot.     

Is personalized medicine finally arriving?

It's no gold rush, but dozens of players are emerging in personalized medicine, with biotechs, big and small, leading the way. Some big pharma companies and even payers remain skeptical, but economics aside, the real winners will be patients.     

Senescence and apoptosis: dueling or complementary cell fates?

In response to a variety of stresses, mammalian cells undergo a persistent proliferative arrest known as cellular senescence. Many senescence‐inducing stressors are potentially oncogenic, strengthening the notion that senescence evolved alongside apoptosis to suppress tumorigenesis. In contrast to apoptosis, senescent cells are stably viable and have the potential to influence neighboring cells through secreted soluble factors, which are collectively known as the senescence‐associated secretory phenotype (SASP). However, the SASP has been associated with structural and functional tissue and organ deterioration and may even have tumor‐promoting effects, raising the interesting evolutionary question of why apoptosis failed to outcompete senescence as a superior cell fate option. Here, we discuss the advantages that the senescence program may have over apoptosis as a tumor protective mechanism, as well as non‐neoplastic functions that may have contributed to its evolution. We also review emerging evidence for the idea that senescent cells are present transiently early in life and are largely beneficial for development, regeneration and homeostasis, and only in advanced age do senescent cells accumulate to an organism's detriment.