A simple cost-effective high performance liquid chromatographic assay of sulphadoxine in whole blood spotted on filter paper for field studies

<p>Abstract</p> <p>Background</p> <p>Artesunate plus sulphadoxine-pyrimethamine is one of the four artemisinin-based combination therapies currently recommended by WHO as first-line treatment for falciparum malaria. Sulphadoxine-pyrimethamine is also used for intermittent preventive treatment for malaria in pregnancy. Drug use patterns and drug pharmacokinetics are important factors impacting the spread of drug resistant parasites hence it is imperative to monitor the effect of pharmacokinetic variability on therapeutic efficacy. Unfortunately, information on the pharmacokinetics of sulphadoxine in children and pregnant women with malaria is very limited. Methods for the assay of sulphadoxine-pyrimethamine have been previously reported, but they are not cost-effective and practicable in analytical laboratories in low resource areas where malaria is endemic. Efforts in this study were thus devoted to development and evaluation of a simple, cost-effective and sensitive method for quantification of sulphadoxine in small capillary samples of whole blood dried on filter paper.</p> <p>Methods</p> <p>Sulphadoxine was determined in whole blood by reversed-phase high performance liquid chromatography with UV detection at 340 nm. Sulisoxazole (SLX) was used as internal standard. Chromatographic separation was achieved using a Beckman Coulter ODS C₁₈and a mobile phase consisting of 0.05 M phosphate buffer-methanol-acetonitrile (70:17:13 V/V/V) containing 1% triethylamine solution.</p> <p>Results</p> <p>Standard curves from sulphadoxine-spiked blood added to filter paper were linear over the concentration range studied. Linear regression analysis yielded correlation coefficient r²> 0.99 (n = 6). Extraction recoveries were about 82-85%. The limit of quantification was 120 ng/ml while the within and between assay coefficient of variations were < 10%. The inter-day precision was < 5.8% and inter-day accuracy ranged from 4.1 to 5.3%. There was no interference from endogenous compounds or any of the commonly used anti-malarial, analgesic and anti-infective drugs with the peaks of SDX or the internal standard.</p> <p>Conclusion</p> <p>The recovery and accuracy of determination of SDX from whole blood filter paper samples using the method described in this study is satisfactory, thus making the method a valuable tool in epidemiological studies and therapeutic drug monitoring in developing endemic countries. Furthermore, the applicability of the method in studying the pharmacokinetic disposition of SDX in a patient suggests that the method is suitable in malaria endemic areas.</p

Stakeholder narratives on trypanosomiasis, their effect on policy and the scope for One Health

Background This paper explores the framings of trypanosomiasis, a widespread and potentially fatal zoonotic disease transmitted by tsetse flies (Glossina species) affecting both humans and livestock. This is a country case study focusing on the political economy of knowledge in Zambia. It is a pertinent time to examine this issue as human population growth and other factors have led to migration into tsetse-inhabited areas with little historical influence from livestock. Disease transmission in new human-wildlife interfaces such as these is a greater risk, and opinions on the best way to manage this are deeply divided. Methods A qualitative case study method was used to examine the narratives on trypanosomiasis in the Zambian policy context through a series of key informant interviews. Interviewees included key actors from international organisations, research organisations and local activists from a variety of perspectives acknowledging the need to explore the relationships between the human, animal and environmental sectors. Principal Findings Diverse framings are held by key actors looking from, variously, the perspectives of wildlife and environmental protection, agricultural development, poverty alleviation, and veterinary and public health. From these viewpoints, four narratives about trypanosomiasis policy were identified, focused around four different beliefs: that trypanosomiasis is protecting the environment, is causing poverty, is not a major problem, and finally, that it is a Zambian rather than international issue to contend with. Within these narratives there are also conflicting views on the best control methods to use and different reasoning behind the pathways of response. These are based on apparently incompatible priorities of people, land, animals, the economy and the environment. The extent to which a One Health approach has been embraced and the potential usefulness of this as a way of reconciling the aims of these framings and narratives is considered throughout the paper. Conclusions/Significance While there has historically been a lack of One Health working in this context, the complex, interacting factors that impact the disease show the need for cross-sector, interdisciplinary decision making to stop rival narratives leading to competing actions. Additional recommendations include implementing: surveillance to assess under-reporting of disease and consequential under-estimation of disease risk; evidence-based decision making; increased and structurally managed funding across countries; and focus on interactions between disease drivers, disease incidence at the community level, and poverty and equity impacts

Etiology of Severe Non-malaria Febrile Illness in Northern Tanzania: A Prospective Cohort Study.

The syndrome of fever is a commonly presenting complaint among persons seeking healthcare in low-resource areas, yet the public health community has not approached fever in a comprehensive manner. In many areas, malaria is over-diagnosed, and patients without malaria have poor outcomes. We prospectively studied a cohort of 870 pediatric and adult febrile admissions to two hospitals in northern Tanzania over the period of one year using conventional standard diagnostic tests to establish fever etiology. Malaria was the clinical diagnosis for 528 (60.7%), but was the actual cause of fever in only 14 (1.6%). By contrast, bacterial, mycobacterial, and fungal bloodstream infections accounted for 85 (9.8%), 14 (1.6%), and 25 (2.9%) febrile admissions, respectively. Acute bacterial zoonoses were identified among 118 (26.2%) of febrile admissions; 16 (13.6%) had brucellosis, 40 (33.9%) leptospirosis, 24 (20.3%) had Q fever, 36 (30.5%) had spotted fever group rickettsioses, and 2 (1.8%) had typhus group rickettsioses. In addition, 55 (7.9%) participants had a confirmed acute arbovirus infection, all due to chikungunya. No patient had a bacterial zoonosis or an arbovirus infection included in the admission differential diagnosis. Malaria was uncommon and over-diagnosed, whereas invasive infections were underappreciated. Bacterial zoonoses and arbovirus infections were highly prevalent yet overlooked. An integrated approach to the syndrome of fever in resource-limited areas is needed to improve patient outcomes and to rationally target disease control efforts

A simple and rapid approach for screening of SARS-coronavirus genotypes: an evaluation study

BACKGROUND: The Severe Acute Respiratory Syndrome (SARS) was a newly emerged infectious disease which caused a global epidemic in 2002–2003. Sequence analysis of SARS-coronavirus isolates revealed that specific genotypes predominated at different periods of the epidemic. This information can be used as a footprint for tracing the epidemiology of infections and monitor viral evolution. However, direct sequencing analysis of a large number of clinical samples is cumbersome and time consuming. We present here a simple and rapid assay for the screening of SARS-coronavirus genotypes based on the use of fluorogenic oligonucleotide probes for allelic discrimination. METHODS: Thirty SARS patients were recruited. Allelic discrimination assays were developed based on the use of fluorogenic oligonucleotide probes (TaqMan). Genotyping of the SARS-coronavirus isolates obtained from these patients were carried out by the allelic discrimination assays and confirmed by direct sequencing. RESULTS: Genotyping based on the allelic discrimination assays were fully concordant with direct sequencing. All of the 30 SARS-coronavirus genotypes studied were characteristic of genotypes previously documented to be associated with the latter part of the epidemic. Seven of the isolates contained a previously reported major deletion but in patients not epidemiologically related to the previously studied cohort. CONCLUSION: We have developed a simple and accurate method for the characterization and screening of SARS-coronavirus genotypes. It is a promising tool for the study of epidemiological relationships between documented cases during an outbreak

Protection of rat renal vitamin E levels by ischemic-preconditioning

BACKGROUND: During renal transplantation, the kidney remains without blood flow for a period of time. The following reperfusion of this ischemic kidney causes functional and structural injury. Formation of oxygen-derived free radicals (OFR) and subsequent lipid peroxidation (LP) has been implicated as the causative factors of these injuries. Vitamin E is known to be the main endogenous antioxidant that stabilizes cell membranes by interfering with LP. The present study was designed to examine the role of ischemic-preconditioning (repeated brief periods of ischemia, IPC) in prevention of renal injury caused by ischemia-reperfusion (IR) in rats. METHODS: IPC included sequential clamping of the right renal artery for 5 min and release of the clamp for another 5 min for a 3 cycles. IR was induced by 30 min ischemia followed by 10 min reperfusion. Four groups of male rats were used: Control, IPC, IR and IPC-IR. Vitamin E, an endogenous antioxidant and as an index of LP, was measured by HPLC and UV detection in renal venous plasma and tissue. Renal function was assessed by serum creatinine and BUN levels. Renal damage was assessed in sections stained with Haematoxylin and Eosin. RESULTS: In the IR group, there was a significant decrease in vitamin E in plasma and tissue compared to a control group (p,0.05). In the IPC-IR group, vitamin E concentration was significantly higher than in the IR group (p,0.01). The results showed that 30 min ischemia in the IR group significantly (p,0.05) reduced renal function demonstrated by an increase in serum creatinine levels as compared with the control group. These results in the IPC group also showed a significant difference with the IR group but no significant difference in serum BUN and creatinine between IR and IPC-IR group were detected. Histological evaluation showed no structural damage in the IPC group and an improvement in the IPC-IR group compared to IR alone. CONCLUSIONS: In this study, IPC preserved vitamin E levels, but it could not markedly improve renal function in the early phase (1–2 h) of reperfusion. IPC may be a useful method for antioxidant preservation in organ transplantation

Ferromagnetism in semiconductors and oxides: prospects from a ten years' perspective

Over the last decade the search for compounds combining the resources of semiconductors and ferromagnets has evolved into an important field of materials science. This endeavour has been fuelled by continual demonstrations of remarkable low-temperature functionalities found for ferromagnetic structures of (Ga,Mn)As, p-(Cd,Mn)Te, and related compounds as well as by ample observations of ferromagnetic signatures at high temperatures in a number of non-metallic systems. In this paper, recent experimental and theoretical developments are reviewed emphasising that, from the one hand, they disentangle many controversies and puzzles accumulated over the last decade and, on the other, offer new research prospects.Comment: review, 13 pages, 8 figures, 109 reference

The course of traumatic pancreatitis in a patient with pancreas divisum: a case report

BACKGROUND: The peculiar anatomy of pancreatic ducts in pancreas divisum (PD) may interfere with the development of acute chronic pancreatitis. In the presented case, PD influenced the evolution of lesions after pancreatic trauma. CASE PRESENTATION: A 38 years old patient refferred to our hospital with recurrent episodes of mild pancreatitis during the last two years. The first episode occurred four months after blunt abdominal trauma. Endoscopic Retrograde Cholangiopancreatography, Magnetic Resonance Imaging of upper abdomen and Magnetic Resonance Cholangiopancreatography disclosed pancreas divisum, changes consistent with chronic pancreatitis in the dorsal pancreatic duct, atrophy in the body and tail of the pancreas and a pseudocyst in the pancreatic head, that was drained endoscopically. CONCLUSION: Pancreas Divisum may interfere with the evolution of posttraumatic changes in the pancreas after blunt abdominal trauma

Construct and face validity of SINERGIA laparoscopic virtual reality simulator

Purpose Laparoscopic techniques have nowadays become a gold standard in many surgical procedures, but they imply a more difficult learning skills process. Simulators have a fundamental role in the formative stage of new surgeons. This paper presents the construct and face validity of SINERGIA laparoscopic virtual reality simulator in order to decide whether it can be considered as an assessment tool. Methods Twenty people participated in this study, 14 were novices and 6 were experts. Five tasks of SINERGIA were included in the study: coordination, navigation, navigation and touch, precise grasping and coordinate traction. For each one of these tasks, a certain number of metrics are automatically recorded. All subjects accomplished each task only once and filled in two questionnaires. A statistical analysis was made and results from both groups were compared with the Mann–Whitney U-test, considering significant differences when P ≤ 0.05. Internal consistency of the system has been analyzed with the Cronbach’s alpha test. Results Novices and experts positively rated SINERGIA characteristics. At least one of the evaluated metrics of each exercise presented significant differences between both groups. Nevertheless, all metrics under study gave a better punctuation to the executions accomplished by experts (lower time, higher efficiency, fewer errors. . .) than to those made by novices. Conclusion SINERGIA laparoscopic virtual reality simulator is able to discriminate subjects according to their level of experience in laparoscopic surgery; therefore, it can be used within a training program as an assessment too

A comprehensive 1000 Genomes-based genome-wide association meta-analysis of coronary artery disease

Existing knowledge of genetic variants affecting risk of coronary artery disease (CAD) is largely based on genome-wide association studies (GWAS) analysis of common SNPs. Leveraging phased haplotypes from the 1000 Genomes Project, we report a GWAS meta-analysis of 185 thousand CAD cases and controls, interrogating 6.7 million common (MAF>0.05) as well as 2.7 million low frequency (0.005<MAF<0.05) variants. In addition to confirmation of most known CAD loci, we identified 10 novel loci, eight additive and two recessive, that contain candidate genes that newly implicate biological processes in vessel walls. We observed intra-locus allelic heterogeneity but little evidence of low frequency variants with larger effects and no evidence of synthetic association. Our analysis provides a comprehensive survey of the fine genetic architecture of CAD showing that genetic susceptibility to this common disease is largely determined by common SNPs of small effect siz

Neuroinflammation, Mast Cells, and Glia: Dangerous Liaisons

The perspective of neuroinflammation as an epiphenomenon following neuron damage is being replaced by the awareness of glia and their importance in neural functions and disorders. Systemic inflammation generates signals that communicate with the brain and leads to changes in metabolism and behavior, with microglia assuming a pro-inflammatory phenotype. Identification of potential peripheral-to-central cellular links is thus a critical step in designing effective therapeutics. Mast cells may fulfill such a role. These resident immune cells are found close to and within peripheral nerves and in brain parenchyma/meninges, where they exercise a key role in orchestrating the inflammatory process from initiation through chronic activation. Mast cells and glia engage in crosstalk that contributes to accelerate disease progression; such interactions become exaggerated with aging and increased cell sensitivity to stress. Emerging evidence for oligodendrocytes, independent of myelin and support of axonal integrity, points to their having strong immune functions, innate immune receptor expression, and production/response to chemokines and cytokines that modulate immune responses in the central nervous system while engaging in crosstalk with microglia and astrocytes. In this review, we summarize the findings related to our understanding of the biology and cellular signaling mechanisms of neuroinflammation, with emphasis on mast cell-glia interactions