Identifying the Components of Acidosis in Patients With Severe Plasmodium falciparum Malaria Using Metabolomics.

BACKGROUND: Acidosis in severe Plasmodium falciparum malaria is associated with high mortality, yet the pathogenesis remains incompletely understood. The aim of this study was to determine the nature and source of metabolic acids contributing to acidosis in patients with severe falciparum malaria. METHODS: A prospective observational study was conducted to characterize circulating acids in adults with P. falciparum malaria (n = 107) and healthy controls (n = 45) from Bangladesh using high-resolution liquid chromatography-mass spectrometry metabolomics. Additional in vitro P. falciparum culture studies were performed to determine if parasites release the acids detected in plasma from patients with severe malaria acidosis. RESULTS: We identified previously unmeasured plasma acids strongly associated with acidosis in severe malaria. Metabolomic analysis of P. falciparum parasites in vitro showed no evidence that these acids are released by the parasite during its life cycle. Instead, 10 of the plasma acids could be mapped to a gut microbial origin. Patients with malaria had low L-citrulline levels, a plasma marker indicating reduced gut barrier integrity. Longitudinal data showed the clearance of these newly identified acids was delayed in fatal cases. CONCLUSIONS: These data suggest that a compromise in intestinal barrier function may contribute significantly to the pathogenesis of life-threatening acidosis in severe falciparum malaria. CLINICAL TRIALS REGISTRATION: NCT02451904.

Rickettsial Illnesses as Important Causes of Febrile Illness in Chittagong, Bangladesh.

We conducted a yearlong prospective study of febrile patients admitted to a tertiary referral hospital in Chittagong, Bangladesh, to assess the proportion of patients with rickettsial illnesses and identify the causative pathogens, strain genotypes, and associated seasonality patterns. We diagnosed scrub typhus in 16.8% (70/416) and murine typhus in 5.8% (24/416) of patients; 2 patients had infections attributable to undifferentiated Rickettsia spp. and 2 had DNA sequence-confirmed R. felis infection. Orientia tsutsugamushi genotypes included Karp, Gilliam, Kato, and TA763-like strains, with a prominence of Karp-like strains. Scrub typhus admissions peaked in a biphasic pattern before and after the rainy season, whereas murine typhus more frequently occurred before the rainy season. Death occurred in 4% (18/416) of cases; case-fatality rates were 4% each for scrub typhus (3/70) and murine typhus (1/28). Overall, 23.1% (96/416) of patients had evidence of treatable rickettsial illnesses, providing important evidence toward optimizing empirical treatment strategies.

Phytochemical and pharmacological evaluation of ethanolic extract of Lepisanthes rubiginosa L. leaves.

BACKGROUND: The current study was conducted to evaluate the antioxidant, analgesic, antihyperglycemic, neuropharmacological and antidiarrheal activities of ethanolic extract of Lepisanthes rubiginosa L. leaves in different experimental models. METHODS: Quantitative and qualitative analysis were done by TLC (thin layer chromatography) and DPPH (1,1-diphenyl-2-picrylhydrazyl) free radical scavenging assay. Analgesic, antihyperglycemic and antidiarrheal activities were evaluated using acetic acid induced writhing in mice, oral glucose tolerance test and castor oil induced diarrhea, respectively. Neuropharmacological activity was investigated in mice using both Open Field and Hole Board methods. RESULTS: TLC analysis indicated the presence of antioxidant compounds in the extract we used. The extract showed IC50 value was 31.62 µg/mL whereas the standard ascorbic acid showed 12.02 µg/mL. In acetic acid induced writhing assay, the extract showed 46.07% and 58.43% writhing inhibition at the doses of 250 mg/kg and 500 mg/kg body weight, respectively whereas standard diclofenac-Na (25 mg/kg) showed 86.52% writhing inhibition. The plant extract showed significant (p < 0.05) antihyperglycemic activity on mice as compared to control groups. In neuropharmacological activity assay the experimental animal showed a noticeable decrease in locomotion by showing a decrease in number of square crossed and head dipping at both doses (250 mg/kg & 500 mg/kg). In antidiarrheal activity test, the plant extract at the doses of 250 mg/kg and 500 mg/kg showed percent inhibition of defecation 57.89 and 77.19 respectively, whereas standard loperamide (3 mg/kg) showed percent inhibition of defecation 88.59. CONCLUSION: The results demonstrated that the extract has potential antioxidant, analgesic, antihyperglycemic, neuropharmacological and antidiarrheal activity.

Wound healing effect of Euphorbia hirta linn. (Euphorbiaceae) in alloxan induced diabetic rats.

BACKGROUND: Euphorbia hirta linn., is a species of Euphorbiaceae family. They are known as asthma plant, barokhervi. The plant E. hirta is famous for its medicinal importance among the tribal population. It is a common practice to use the whole to heal wounds. Several pharmacological properties including antiseptic, anti-inflammatory, antidibetic, antispasmodic, antibacterial, antiviral, antifungal, anticonvulsant, nootropic, antifertility and aphrodisiac properties have already been reported for this plant. The aim of present work was to evaluate the wound healing property in diabetic animals by oral and topical administration of ethanolic extract of E. hirta whole plant. METHODS: The ethanolic extract of E. hirta was subjected to determine the total phenolic content and total flavonoid content using galic acid and quercetin, respectively as standard. A single injection of alloxan monohydrate (120 mg/kg, i.p.) prepared in normal saline was administered to produce diabetes in rats, after overnight fasting. For analyzing the rate of contraction of wound, excision wounds sized 4.90cm2 and of 2 mm depth were used. Oral (100, 200 and 400 mg/kg/day; p.o.) and topical treatment with the extract (5% and 10% ointment 50 mg/kg/day) and standard (5% povidone iodine ointment 50 mg/kg/day) was started on the day of induction of wound and continued up to 16 days. The means of wound area measurement between groups at different time intervals were compared using ANOVA and Dunnet's test. The diabetic wound healing mechanism was studied by measuring the plasma level of glucose, malondialdehyde (MDA) and nitric oxide (NO) in both control and treated groups. For the confirmation of activity, histopathology of the wounds tissues from excision wound model was performed. RESULTS: Phytochemical investigations showed the presence of various phytoconstituents (carbohydrates, saponins, alkaloids, glycosides, steroids, flavonoids, tannins). In the ethanolic extract of E. hirta the total phenol content was 285 ± 3.22 mg/g whereas the total flavonoid content was 118.46 ± 1.85 mg/g. In the present study, E. hirta caused significant wound closer both orally (35.92%, 44.69% and 61.42% at the doses of 100, 200 and 400, respectively) and topically (32.86% and 36.32% at the doses of 5% and 10%) treated groups as compared to diabetic control. However, the orally treated groups showed more significant effect than the topically treated groups. Moreover, oral administration of E. hirta ethanolic extract significantly reduced the blood glucose levels in diabetic wound rats (p < 0.01) on day 8 and day 16 as compared to the diabetic wound control (p < 0.01). On the other hand, topical application of E. hirta did not influence the blood glucose levels in diabetic rats (p > 0.05). It also demonstrated a significant decrease in the plasma levels of lipid malondialdehyde and nitric oxide. The results of biochemical parameters were further supported by the histopathological changes of different organs (liver, pancrease, kidney, heart and skin from wound area) which were evidenced through a decrease in inflammatory cell infiltration. CONCLUSION: The present study demonstrates that E. hirta whole plant extract promotes healing of wounds more significantly as compared to diabetic control rats, where healing is otherwise delayed.

Evaluation of anti-inflammatory and gastric anti-ulcer activity of Phyllanthus niruri L. (Euphorbiaceae) leaves in experimental rats.

BACKGROUND: The medicinal plants signify a massive basin of potential phytoconstituents that could be valuable as a substitute to allopathic drugs or considered as an analogue in drug development. Phyllanthus niruri L. (Euphorbiaceae) is generally used in traditional medicine to treat ulcer and inflammation. In this project we investigated the methanolic extract of leaves of Phyllanthus niruri for anti-inflammatory and anti-ulcer activity. METHODS: The anti-inflammatory activity of methanol extract of Phyllanthus niruri leaves was evaluated at the doses of 100, 200 and 400 mg/kg, p.o. while using ibuprofen (20 mg/kg, p.o) as the standard drug. The animals used were Swiss albino rats. Inflammation was induced by injecting 0.1 ml carrageenan (1% w/v) into the left hind paw. Paw tissues from the different groups were examined for inflammatory cell infiltration. On the other hand, antiulcer activity of methanolic extract of P. niruri leaves at the doses of 100, 200 and 400 mg/kg, p.o. were examined against ethanol-acid induced gastric mucosal injury in the Swiss albino rats - keeping omeprazole (20 mg/kg, p.o.) as reference. The rats were dissected and the stomachs were macroscopically examined to identify hemorrhagic lesions in the glandular mucosa. RESULTS: P. niruri significantly (p < 0.01) decreased carrageenan-induced paw edema; it exhibited a reduction of 46.80%, 55.32% and 69.14% at doses of 100, 200 and 400 mg/kg, respectively. These findings were further supported by the histological study. The methanolic extract also disclosed good protective effect against ethanol-acid induced gastric mucosal injury in the rats. Administration of the extract's doses (100, 200 and 400 mg/kg) demonstrated a significant (p < 0.01) reduction in the ethanol- acid induced gastric erosion in all the experimental groups when compared to the control. The methanolic extract at the higher dose (400 mg/kg) resulted in better inhibition of ethanol-acid induced gastric ulcer as compare to omeprazole (20 mg/kg). Histological studies of the gastric wall revealed that toxic control rats revealed mucosal degeneration, ulceration and migration of numerous inflammatory cells throughout the section. On the other hand, MEPN treatment groups showed significant regeneration of mucosal layer and significantly prevented the formation of hemorrhage and edema. CONCLUSIONS: The investigation suggests that methanolic extract of P. niruri leaf possess anti-inflammatory activity and promotes ulcer protection as ascertained by regeneration of mucosal layer and substantial prevention of the formation of hemorrhage and edema.

Sequestration and Red Cell Deformability as Determinants of Hyperlactatemia in Falciparum Malaria.

BACKGROUND: Hyperlactatemia is a strong predictor of mortality in severe falciparum malaria. Sequestered parasitized erythrocytes and reduced uninfected red blood cell deformability (RCD) compromise microcirculatory flow, leading to anaerobic glycolysis. METHODS: In a cohort of patients with falciparum malaria hospitalized in Chittagong, Bangladesh, bulk RCD was measured using a laser diffraction technique, and parasite biomass was estimated from plasma concentrations of Plasmodium falciparum histidine-rich protein 2 (PfHRP2). A multiple linear regression model was constructed to examine their associations with plasma lactate concentrations. RESULTS: A total of 286 patients with falciparum malaria were studied, of whom 224 had severe malaria, and 70 died. Hyperlactatemia (lactate level, ≥ 4 mmol/L) was present in 111 cases. RCD at shear stresses of 1.7 Pa and 30 Pa was reduced significantly in patients who died, compared with survivors, individuals with uncomplicated malaria, or healthy individuals (P < .05, for all comparisons). Multiple linear regression analysis showed that the plasma PfHRP2 level, parasitemia level, total bilirubin level, and RCD at a shear stress of 1.7 Pa were each independently correlated with plasma lactate concentrations (n = 278; R(2) = 0.35). CONCLUSIONS: Sequestration of parasitized red blood cells and reduced RCD both contribute to decreased microcirculatory flow in severe disease.

Participants' perceptions and understanding of a malaria clinical trial in Bangladesh.

BACKGROUND: Existing evidence suggests that there is often limited understanding among participants in clinical trials about the informed consent process, resulting in their providing consent without really understanding the purpose of the study, specific procedures, and their rights. The objective of the study was to determine the subjects' understanding of research, perceptions of voluntariness and motivations for participation in a malaria clinical trial. METHODS: In this study semi-structured interviews of adult clinical trial participants with uncomplicated falciparum malaria were conducted in Ramu Upazila Health Complex, in Bangladesh. RESULTS: Of 16 participants, the vast majority (81%) were illiterate. All subjects had a 'therapeutic misconception' i.e. the trial was perceived to be conducted primarily for the benefit of individual patients when in fact the main objective was to provide information to inform public health policy. From the patients' perspective, getting well from their illness was their major concern. Poor actual understanding of trial specific procedures was reported despite participants' satisfaction with treatment and nursing care. CONCLUSION: There is frequently a degree of overlap between research and provision of clinical care in malaria research studies. Patients may be motivated to participate to research without a good understanding of the principal objectives of the study despite a lengthy consent process. The findings suggest that use of a standard consent form following the current ICH-GCP guidelines does not result in achieving fully informed consent and the process should be revised, simplified and adapted to individual trial settings.

Magnetic resonance imaging of the brain in adults with severe falciparum malaria.

BACKGROUND: Magnetic resonance imaging (MRI) allows detailed study of structural and functional changes in the brain in patients with cerebral malaria. METHODS: In a prospective observational study in adult Bangladeshi patients with severe falciparum malaria, MRI findings in the brain were correlated with clinical and laboratory parameters, retinal photography and optic nerve sheath diameter (ONSD) ultrasound (a marker of intracranial pressure). RESULTS: Of 43 enrolled patients, 31 (72%) had coma and 12 (28%) died. MRI abnormalities were present in 79% overall with mostly mild changes in a wide range of anatomical sites. There were no differences in MRI findings between patients with cerebral and non-cerebral or fatal and non-fatal disease. Subtle diffuse cerebral swelling was common (n = 22/43), but mostly without vasogenic oedema or raised intracranial pressure (ONSD). Also seen were focal extracellular oedema (n = 11/43), cytotoxic oedema (n = 8/23) and mildly raised brain lactate on magnetic resonance spectroscopy (n = 5/14). Abnormalities were much less prominent than previously described in Malawian children. Retinal whitening was present in 36/43 (84%) patients and was more common and severe in patients with coma. CONCLUSION: Cerebral swelling is mild and not specific to coma or death in adult severe falciparum malaria. This differs markedly from African children. Retinal whitening, reflecting heterogeneous obstruction of the central nervous system microcirculation by sequestered parasites resulting in small patches of ischemia, is associated with coma and this process is likely important in the pathogenesis.

Relative contributions of macrovascular and microvascular dysfunction to disease severity in falciparum malaria.

BACKGROUND: Sequestration of parasitized erythrocytes in the microcirculation is considered the central pathophysiological process in severe falciparum malaria. Hypovolemia with reduced oxygen delivery and microvascular obstruction have different implications for patient management; however, their relative contributions to disease severity are uncertain. METHODS: Adult patients (n = 28) with severe Plasmodium falciparum malaria were enrolled in a prospective hemodynamic study. Volume status and oxygen delivery were assessed using transpulmonary thermodilution. Microvascular sequestration was measured using orthogonal polarized spectroscopy. FINDINGS: Duration of therapy before study enrollment was correlated with the amount of directly visualized and quantitated microvascular sequestration (P = .03). The amount of sequestration correlated with plasma lactate (r(s )= 0.55; P = .003) and disease severity (r(s )= 0.41; P = .04). In patients who had received artesunate for <10 hours, sequestration was higher in fatal cases than in survivors: median (range) 45% (32-50) vs 15% (0-40); P = .03). Parasite biomass estimated from plasma P. falciparum histidine-rich protein 2 correlated positively with disease severity (r(s )= 0.48; P = .01) and was significantly higher in patients who died (P = .046). There was no relationship between oxygen delivery and disease severity (P = .64) or outcome (P = .74). INTERPRETATION: Vital organ dysfunction in severe malaria results primarily from sequestration of parasitized erythrocytes in the microvasculature rather than reduction in circulating blood volume and oxygen delivery.

Analysis of E-cadherin (CDH1) Gene Polymorphism and Its Association with Cervical Cancer Risk in Bangladeshi Women.

BACKGROUND: E-cadherin (CDH1), a tumor suppressor gene, encodes a transmembrane glycoprotein that helps in maintaining squamous epithelium integrity of the cervix. We aimed to investigate the association between -160C/A genetic polymorphism in CDH1 and the risk of cervical cancer in Bangladeshi females. METHOD: The present case-control study included 117 cervical cancer cases and 147 age-matched controls. The genomic DNA was extracted from peripheral blood and genotyped by using PCR-RFLP analysis. RESULTS: Genotyping results demonstrated that the occurrences of normal homozygous (-160C/C), heterozygous (-160C/A) and variant homozygous (-160A/A) genotypes were 64.10, 27.35 and 8.55% in cases, and 77.55, 19.73 and 2.72% in controls, respectively. Compared to normal C/C genotype, variant A/A and combined (C/A+A/A) or 'any A' genotypes exhibited 3.80-fold (95% CI=1.150-12.561, P=0.029) and 1.93-fold (95% CI=1.126-3.323, P=0.017) increased risk of cervical cancer development. The -160C allele was found to be positively linked to cervical cancer incidence and raised the risk by 1.81-fold (OR= 1.814, 95% CI=1.152-2.857, p=0.01). Moreover, women carrying -160A/A variant homozygosity along with an early marital history (<18 years) were more susceptible to cervical cancer development (χ2 =6.605, p=0.037). CONCLUSION: The study suggests that the (A/A) and combined (C/A +A/A) genotypes are associated with greater risk of cervical cancer in Bangladeshi women.

Effects of antibiotic, acidifier, and probiotic supplementation on mortality rates, lipoprotein profile, and carcass traits of broiler chickens.

Antimicrobial resistance is a significant issue, therefore it's relevant to assess the effects of antibiotics, acidifiers, and probiotic supplementation finding a good alternative to reduce the use of antibiotics in broiler production in rural areas of Bangladesh. Using randomized control trial, this 28-day study evaluated 360 Hubbard Classic broiler chicks divided into four groups: oxytetracycline-treated, acidifier-treated, Lactobacillus-based probiotic-treated, and control (no antibiotics, acidifiers, or probiotics). Each group was replicated three times with 30 birds each with adlibitum feeding. Body weight and feed intake were recorded weekly, and on 28th day, carcass traits and blood lipoprotein levels were evaluated. Results showed that in first and fourth weeks, the body weight gain significantly varied in probiotics and acidifier-treated birds than the control group (P < 0.001). The probiotic group had gained considerable increase in body weight (185.0 g vs 161.7 g and 1745.0 g vs 1592.7 g) than the control group. Notably, in the first week, the feed conversion ratio for the probiotic group was 0.76, but the antibiotic group's was 0.96 (P < 0.001). The weights of the drumstick (88.33 g) and liver (61.0 g) having probiotic supplements were substantially higher than those in the control group (77.0 g and 51.33 g, respectively) (P < 0.001). According to serum lipoprotein analysis, the probiotic and acidifier groups exhibited lower LDL levels (71.1 mg/dl and 69.8 mg/dl, respectively) and higher triglyceride levels (122.9 mg/dl and 135.4 mg/dl). These findings highlight the potential of probiotics and acidifiers as effective antibiotic alternatives, promoting carcass traits and lowering LDL levels in broilers in Bangladesh.

Using behavioural science to explore impact and implementation of obstetric anaesthesia training in Tanzania, Nepal and Bangladesh: a qualitative evaluation study with obstetric anaesthesia providers.

Objective: High quality obstetric anaesthetic care is integral to reducing preventable maternal deaths in Low-and-Middle-Income-Countries (LMICs). We applied behavioural science to evaluate SAFE Obstetrics, a 3-day Continuing Professional Development (CPD) course, on physician and non-physician anaesthetists' practice behaviours across 3 LMICs.Methods: Seven anaesthetist Fellows from Bangladesh, Nepal and Tanzania were trained in qualitative methods and behavioural science. Structured interviews were undertaken by Fellows and two UK behavioural scientists with course participants. Interviews were based on the Theoretical Domains Framework: a comprehensive framework of influences on behaviour change. Interviews were recorded, transcribed and analysed using content and thematic analysis.Results: 78 physician and non-physician anaesthetists participated (n = 26 Bangladesh, n = 24 Nepal and n = 28 Tanzania). Participants reported positive improvements in patient-centered working, safety, teamwork and confidence. Across countries, we found similar barriers and facilitators: environmental resources, a strong professional identity and positive social influences were key facilitators of change.Conclusion: This multi-country theory-based evaluation highlighted the impact of SAFE Obstetrics on participants' clinical practice. A supportive work environment was crucial for implementing learning following training; CPD courses in LMICs must furnish participants with skills and equipment to address training implementation challenges. Building local behavioural science capacity can strengthen LMIC health intervention evaluations.

The use of placebo in a trial of rectal artesunate as initial treatment for severe malaria patients en route to referral clinics: ethical issues.

Placebo-controlled trials are controversial when individuals might be denied existing beneficial medical interventions. In the case of malaria, most patients die in rural villages without healthcare facilities. An artesunate suppository that can be given by minimally skilled persons might be of value when patients suddenly become too ill for oral treatment but are several hours from a facility that can give injectable treatment for severe disease. In such situations, by default, no treatment is (or can be) given until the patient reaches a facility, making the placebo control design clinically relevant; alternative bioequivalence designs at the facility would misrepresent reality and risk incorrect conclusions. We describe the ethical issues underpinning a placebo-controlled trial in severe malaria. To protect patients and minimise risk, all patients were referred immediately to hospital so that each had a higher chance of prompt treatment through participation. There was no difference between artesunate and placebo in patients who reached clinic rapidly; among those who could not, a single artesunate suppository significantly reduced death or permanent disability, a finding of direct and indirect benefit to patients in participating villages and elsewhere.

Metabolic Acidosis, Hyperkalemia, and Renal Unresponsiveness to Aldosterone Syndrome: Response to Treatment with Low-Potassium Diet.

Gordon syndrome involves hyperkalemia, acidosis, and severe hypertension (HTN) with hypercalciuria, low renin and aldosterone levels. It is commonly observed in children and adolescents. Such patients respond successfully to sodium restriction and thiazide diuretics. In this article, we present three cases of metabolic acidosis, hyperkalemia, and renal unresponsiveness to aldosterone (MeHandRU Syndrome). All three patients did not have HTN or hypercalciuria and demonstrated normal renin and aldosterone levels. These patients did not respond to thiazide-type diuretic therapy and salt restriction. Two males (aged 55- and 62-year) and a female patient (aged 68-year) presented to the clinic with unexplained hyperkalemia (5.9 mEq/L, 5.9 mEq/L and 6.2 mEq/L, respectively). On physical examination, blood pressure (BP) was found to be normal (<140/90 mm Hg). Over the counter potassium supplement, nonsteroidal anti-inflammatory drugs, angiotensin converting enzyme inhibitors, angiotensin receptor blockers, potassium sparing diuretic use, as well as hyporeninemic hypoaldosteronism states such as diabetes mellitus were excluded. Plasma renin and aldosterone levels were normal. All three patients had low transtubular potassium gradient, despite high serum potassium levels. None of the patients reported a family history of hyperkalemia or kidney failure. All failed to demonstrate a response to hydrochlorothiazide and salt restriction. After careful consideration, strict low potassium diet (<2 g/day) was initiated in consultation with the dietician. Diuretic therapy was discontinued while BP remained within normal range (<140/90 mm Hg). At eight weeks, all three patients demonstrated normalization of potassium and correction of acidosis. At follow-up of six months, all patients are maintaining a normal potassium level. We suggest that potassium restriction can be successful in patients presenting with MeHandRU syndrome.

Antioxidant and hepatoprotective activity of Piper retrofractum against Paracetamol-induced hepatotoxicity in Sprague-Dawley rat.

The ethanol extracts of Piper retrofractum were investigated for antioxidant and hepatoprotective activity. Hepatoprotective activity against paracetamol-induced acute hepatotoxicity was estimated in Sprague-Dawley rat. In DPPH free radical assay the root and stem extracts showed IC50 values at 133 and 91 µg/mL, respectively, while ascorbic acid at 14 µg/mL. Extracts also exhibited hydroxyl radical scavenging activity and reducing power. HPLC-DAD analysis indicated the presence of some polyphenolic compounds. Treatment of extracts significantly reduced the elevated serum levels of GPT (P < 0.01), GOT (P < 0.01) and bilirubin (P < 0.001). Both extracts restored the reduced level of total proteins and albumin. A significant increase in HDL-c but decrease in LDL-c level was observed compared to induced control. In histopathological study of liver sections, both extracts showed minimal to mild multifocal and diffuse granular degeneration and mild to moderate lobular disarray compared to control group. Results suggest that both extracts can prevent paracetamol induced hepatotoxicity.

Comparison of two models of surface display of xylose reductase in the Saccharomyces cerevisiae cell wall.

In order to display xylose reductase at the surface of S. cerevisiae cells two different gene constructs have been prepared. In the first, xylose reductase gene GRE3 was fused with two parts of the CCW12 gene, the N-terminal one coding for the secretion signal sequence, and the C-terminal coding for the glycosylphosphatidylinositol anchoring signal. Transformed cells synthesized xylose reductase and incorporated it in the cell wall through the remnant of the glycosylphosphatidylinositol anchor. The other construct was prepared by fusing the GRE3 with the PIR4 gene coding for one of the proteins of the Pir-family containing the characteristic N-terminal repetitive sequence that anchors Pir proteins to ß-1,3-glucan. In this way xylose reductase was covalently attached to glucan through its N-terminus. For the expression of the constructs either the GAL1, or the PHO5 promoters have been used. Both strains displayed active xylose reductases and their enzyme properties were compared with the control enzyme bearing the secretion signal sequence but no anchoring signals, thus secreted into the medium. The enzyme displayed through the N-terminal fusion with PIR4 had higher affinity for xylose than the other construct, but they both expressed somewhat lower affinity than the control enzyme. Similarly, the Km values for NADPH of both immobilized enzymes were somewhat higher than the Km of the control XR. Both displayed enzymes, especially the one fused with Pir4, had higher thermal and pH stability than the control, while other enzymatic properties were not significantly impaired by surface immobilization.

Amino acid derangements in adults with severe falciparum malaria.

Amino acid derangements are common in severe falciparum malaria and have been associated with endothelial dysfunction (L-arginine), metabolic acidosis (alanine and lactate), and disease severity (phenylalanine and tryptophan metabolites). Whether these amino acid perturbations reflect isolated pathogenic mechanisms or if they are part of overall changes in amino acid metabolism is unclear. To investigate this, we prospectively simultaneously quantified a broad range of plasma free amino acids (PFAA) using HPLC-MRM-Mass spectrometry in relation to presenting symptoms in adults with severe malaria (n = 88), septicaemia (n = 88), uncomplicated malaria (n = 71), and healthy controls (n = 48) from Bangladesh. The total plasma concentration of measured amino acids was significantly reduced in each of the patient groups when compared to normal levels observed in healthy local controls: uncomplicated malaria -54%, severe malaria -23%, and sepsis -32%, (p = <0.001). Inspection of amino acid profiles revealed that in each group the majority of amino acids were below normal levels, except for phenylalanine. Among patients with severe malaria, L-lactate was strongly associated with an increase of the total amino acid concentration, likely because this reflects tissue hypoxia. Our data confirm previously described amino acid abnormalities, likely resulting from overall changes in the concentration of PFAA.

Malaria in southeast Bangladesh: a descriptive study.

Malaria in Asia is thought to be grossly under-reported and this is evident from previously published statistics from Bangladesh. Malaria screening data from four Upazillas was analysed alongside census data to assess the trends in malaria incidence over time and distribution of malaria by age and gender. Malaria incidence in this area has decreased by around two thirds since 2003, although control measures were not significantly increased until 2005. Malaria occurred in people of all ages with the highest incidence being in young adults. This is consistent with higher occupational exposure in this group. The probability of being screened for malaria decreased with age suggesting significant numbers of adults with malaria may be being missed.

Diagnostic Accuracy of the InBios Scrub Typhus Detect™ ELISA for the Detection of IgM Antibodies in Chittagong, Bangladesh.

Here we estimated the accuracy of the InBios Scrub Typhus Detect™ immunoglobulin M (IgM) ELISA to determine the optimal optical density (OD) cut-off values for the diagnosis of scrub typhus. Patients with undifferentiated febrile illness from Chittagong, Bangladesh, provided samples for reference testing using (i) qPCR using the Orientia spp. 47-kDa htra gene, (ii) IFA ≥1:3200 on admission, (iii) immunofluorescence assay (IFA) ≥1:3200 on admission or 4-fold rise to ≥3200, and (iv) combination of PCR and IFA positivity. For sero-epidemiological purposes (ELISA vs. IFA ≥1:3200 on admission or 4-fold rise to ≥3200), the OD cut-off for admission samples was ≥1.25, resulting in a sensitivity (Sn) of 91.5 (95% confidence interval (95% CI: 96.8⁻82.5) and a specificity (Sp) of 92.4 (95% CI: 95.0⁻89.0), while for convalescent samples the OD cut-off was ≥1.50 with Sn of 66.0 (95% CI: 78.5⁻51.7) and Sp of 96.0 (95% CI: 98.3⁻92.3). Comparisons against comparator reference tests (ELISA vs. all tests including PCR) indicated the most appropriate cut-off OD to be within the range of 0.75⁻1.25. For admission samples, the best Sn/Sp compromise was at 1.25 OD (Sn 91.5%, Sp 92.4%) and for convalescent samples at 0.75 OD (Sn 69.8%, Sp 89.5%). A relatively high (stringent) diagnostic cut-off value provides increased diagnostic accuracy with high sensitivity and specificity in the majority of cases, while lowering the cut-off runs the risk of false positivity. This study underlines the need for regional assessment of new diagnostic tests according to the level of endemicity of the disease given the high levels of residual or cross-reacting antibodies in the general population.

TP53 codon 72 polymorphism and breast cancer risk in Bangladeshi population.

BACKGROUND: Breast cancer, a hereditary or heterogeneous sporadic disease, is the most common cancer in women worldwide. The tumor suppressor TP53 gene has been found to be the most commonly mutated genes in many types of human cancers, including breast cancer. This study aimed to investigate the association of codon 72 polymorphism of TP53 gene with breast cancer risk in Bangladeshi females. METHODS: The study included 125 cases and 125 healthy controls. Genotyping and polymorphism were determined by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis. RESULTS: The frequencies of the three genotypes Arg/Arg, Arg/Pro, and Pro/Pro were 43.2, 33.6, and 23.2% in cases, whereas 48.8, 40.8, and 10.4% in controls, respectively. The frequency of mutant homozygous (Pro/Pro) genotype was significantly increased in breast cancer patients as compared with controls (23.2 vs 10.4%), and showed 2.52-fold significantly increased risk for breast cancer (OR 2.5199, 95% CI 1.19-5.33, p = 0.0157). The frequencies of Pro/Pro genotype were significantly higher in breast cancer cases with non-breast feeding status. Pro allele frequency was found to be significantly increased in breast cancer cases (OR 1.4978, 95% CI 1.0357-2.1662, p = 0.0318). CONCLUSIONS: Our data suggest that mutant (Pro/Pro) homozygosity at codon 72 of TP53 gene is significantly associated with breast cancer susceptibility in Bangladeshi women. In addition, this association was significantly related to lactating status.