For ethical and logistical reasons, population-genetic studies of parasites often rely on the non-invasive sampling of offspring shed from their definitive hosts. However, if the sampled offspring are naturally derived from a small number of parents, then the strong family structure can result in biased population-level estimates of genetic parameters, particularly if reproductive output is skewed. Here, we document and correct for the strong family structure present within schistosome offspring (miracidia) that were collected non-invasively from humans in western Kenya. By genotyping 2,424 miracidia from 12 patients at 12 microsatellite loci and using a sibship clustering program, we found that the samples contained large numbers of siblings. Furthermore, reproductive success of the breeding schistosomes was skewed, creating differential representation of each family in the offspring pool. After removing the family structure with an iterative jacknifing procedure, we demonstrated that the presence of relatives led to inflated estimates of genetic differentiation and linkage disequilibrium, and downwardly-biased estimates of inbreeding coefficients (FIS). For example, correcting for family structure yielded estimates of FST among patients that were 27 times lower than estimates from the uncorrected samples. These biased estimates would cause one to draw false conclusions regarding these parameters in the adult population. We also found from our analyses that estimates of the number of full sibling families and other genetic parameters of samples of miracidia were highly intercorrelated but are not correlated with estimates of worm burden obtained via egg counting (Kato-Katz). Whether genetic methods or the traditional Kato-Katz estimator provide a better estimate of actual number of adult worms remains to be seen. This study illustrates that family structure must be explicitly accounted for when using offspring samples to estimate the genetic parameters of adult parasite populations.
Genetic epidemiology uses genetic data to uncover patterns of disease processes. To acquire data for these analyses, individual pathogens are collected and scored at genetic markers, and the resultant data are analyzed to infer biological patterns about the pathogen populations. In lieu of invasive sampling of adult pathogens in humans, researchers have relied on non-invasive sampling of parasite offspring (often shed in fecal samples). One potential problem with this approach is that analyses using the offspring data will be biased because many of the offspring are related and family sizes are likely to be unequal. We show that this sampling issue is relevant in a natural transmission zone in western Kenya and that it yields biases in three important parameters: genetic differentiation, inbreeding coefficients, and estimates of the amount of non-random association between loci (linkage disequilibrium). We also develop a method to remove these biases by removing the sibling structure present in the dataset. Finally, we suggest that our measure of family number, as well as other genetic measures, may be useful measures of the worm burdens in patients.
A vaccine against schistosomiasis would contribute significantly to reducing the 3-70 million disability-adjusted life years lost annually to the disease. Towards this end, inoculation with the large extracellular loop (EC-2) of Schistosoma mansoni tetraspanin-2 protein (Sm-TSP-2) has proved effective in reducing worm and egg burdens in S. mansoni-infected mice. The EC-2 loop of S. japonicum TSP-2, however, has been found to be highly polymorphic, perhaps diminishing the likelihood that this antigen can be used for vaccination against this species. Here, we examine polymorphism of the EC-2 of Sm-TSP-2 in genetically unique worms derived from six individuals from Kisumu, Kenya.
Schistosoma; Polymorphism; Tetraspanin-2; Genotype; Kozak sequence; Vaccine
Diabetes mellitus type 1 is an autoimmune disorder caused by lymphocytic infiltration and beta cells destruction. Curcumin has been identified as a potent inducer of heme-oxygenase-1 (HO-1), a redoxsensitive inducible protein that provides protection against various forms of stress. A novel water soluble curcumin derivative (NCD) has been developed to overcome low in vivo bioavailability of curcumin. The aim of the present work is to evaluate the anti diabetic effects of the “NCD” and its effects on diabetes-induced ROS generation and lipid peroxidation in experimental type- 1 diabetes mellitus. We also examine whether the up regulation of HO-1 accompanied by increased HO activity mediates these antidiabetic and anti oxidant actions.
Materials and methods
Rats were divided into control group, control group receiving curcumin derivative, diabetic group, diabetic group receiving curcumin derivative and diabetic group receiving curcumin derivative and HO inhibitor ZnPP. Type-1 diabetes was induced by intraperitoneal injection of streptozotocin. Curcumin derivative was given orally for 45 days. At the planned sacrification time (after 45 days), fasting blood samples were withdrawn for estimation of plasma glucose, plasma insulin and lipid profile . Animals were sacrificed; pancreas, aorta and liver were excised for the heme oxygenase - 1 expression, activity and malondialdehyde estimation.
NCD supplementation to diabetic rats significantly lowered the plasma glucose by 27.5% and increased plasma insulin by 66.67%. On the other hand, the mean plasma glucose level in the control group showed no significant difference compared to the control group receiving the oral NCD whereas, NCD supplementation to the control rats significantly increased the plasma insulin by 47.13% compared to the control. NCD decreased total cholesterol, triglycerides, LDL cholesterol and increased HDL cholesterol levels. Also, it decreased lipid peroxides (malondialdehyde) in the pancreas, aorta and liver.
The (NCD) by its small dose possesses antidiabetic actions and that heme oxygenase induction seems to play an important role in its anti-diabetic effects. NCD also improves the lipid profile and oxidative status directly, proved by decreasing lipid peroxides (malondialdehyde) in pancreas, liver & aorta. The new water soluble curcumin derivative still retains the essential potencies of natural curcumin.
Diabetes Type 1; Heme oxygenase −1; Curcumin; Insulin secretion; Oxidative stress
A 30-year-old female patient presented to the gynecology clinic with a small (painless) swelling at the urethral orifice. She underwent surgical excision of the lesion. Pathological examination revealed non-Hodgkin's lymphoma of diffuse large B-cell type and mucosa-associated lymphoid tissue type, stage IE. The patient refused radiotherapy. Accordingly, we started CHOP-R chemotherapy. She received a total of 6 cycles of CHOP and 8 cycles of rituximab. Patient follow-up was done 3 months later through CT scan and cytoscopy confirming the complete remission. The patient has been disease-free for 4 years. We reviewed 26 cases of this rare entity reported previously.
Urethra; NHL; Chemotherapy; Malignant lymphoma; Female urethra; CHOP-R chemotherapy
In the title compound, C12H12N2O3S·2C2H6OS, the acetic acid and cinnamoyl groups adopt Z and E configurations, respectively, with respect to the thio group about the C—N bonds. The components of the asymmetric unit are connected by N—H⋯O and O—H⋯O hydrogen bonds and in the crystal weak intermolecular C—H⋯O and C—H⋯S hydrogen bonds further connect the components into chains along the b axis. In the main molecule, an intramolecular N—H⋯O hydrogen bond is also present.
The thiono and carbonyl groups in the title compound, C21H18N2O2S, adopt an anti disposition with respect to the central C—N bond. The diphenylamine rings are twisted relative to each other by a dihedral angle of 82.55 (10)°. The 3-methoxybenzoyl fragment is twisted relative to one of the diphenylamine rings, forming a dihedral angle of 74.04 (9)°. In the crystal, pairs of intermolecular N—H⋯S hydrogen bonds link the molecules into centrosymmetric dimers, forming columns parallel to the a axis.
In the title compound, C22H19FN2OS, the 2-fluorobenzoyl group adopts a trans conformation with respect to the thiono S atom across the N—C bond. In the crystal, intermolecular N—H⋯S, C—H⋯S and C—H⋯O hydrogen bonds link the molecules, forming a two-dimensional network parallel to (101).
BRAF, a cellular oncogene and effector of RAS-mediated signaling, is activated by mutation in ~60% of melano-mas. Most of these mutations consist of a V600E substitution resulting in constitutive kinase activation. Mutant BRAF thus represents an important therapeutic target in melanoma. In an effort to produce a pre-clinical model of mutant BRAF function in melanoma, we have generated a mouse expressing BRAF V600E targeted to melanocytes. We show that in these transgenic mice, widespread benign melanocytic hyperplasia with histolo-gical features of nevi occurs, with biochemical evidence of senescence. Melanocytic hyperplasia progresses to overt melanoma with an incidence dependent on BRAF expression levels. Melanomas show CDKN2A loss, and genetic disruption of the CDKN2A locus greatly enhances melanoma formation, consistent with collaboration between BRAF activation and CDKN2A loss suggested from studies of human melanoma. The development of melanoma also involves activation of the Mapk and Akt signaling pathways and loss of senescence, findings that faithfully recapitulate those seen in human melanomas. This murine model of mutant BRAF-induced melanoma formation thus provides an important tool for identifying further genetic alterations that cooperates with BRAF and that may be useful in enhancing susceptibility to BRAF-targeted therapeutics in melanoma.
BRAF; p53; CDKN2A; AKT; melanoma; senescence
In the title compound, C22H19ClN2OS, the thiono and carbonyl groups are trans positioned with respect to a partially double C—N bond. The amide group is twisted relative to the thiourea fragment, forming a dihedral angle of 46.75 (11)°. In the crystal, intermolecular N—H⋯S and C—H⋯O hydrogen bonds link the molecules into a one-dimensional polymeric structure parallel to the c axis.
The 2-bromobenzoyl group in the title compound, C22H19BrN2OS, adopts an E conformation with respect to the thiono S atom across the N—C bond. In the crystal structure, the molecule is stablized by N—H⋯O intermolecular hydrogen bonds, forming a one-dimensional chain along the b axis.
In the title compound, C12H14N2O3S, the propyl acetate group and the benzoyl group adopt a cis–trans conformation, respectively, with respect to the thiono S atom across the C—N bonds. The phenyl ring is twisted relative to the the thiourea mean plane, forming a dihedral angle of 24.16 (9)°. An intramolecular N—H⋯O hydrogen bond occurs. The crystal packing is stabilized by intermolecular N—H⋯O and C—H⋯O hydrogen bonds, forming a chain along the a axis.
HuHMFG1 (AS1402) is a humanised monoclonal antibody that has undergone a phase I trial in metastatic breast cancer. The aim of this study was to characterise the pharmacokinetics (PKs) of HuHMFG1 using a population PK model.
Data were derived from a phase I study of 26 patients receiving HuHMFG1 at doses ranging from 1 to 16 mg kg−1. Data were analysed using NONMEM software and covariates were included. A limited sampling strategy (LSS) was developed using training and a validation data set.
A linear two-compartment model was shown to be adequate to describe data. Covariate analysis indicated that weight was not related to clearance. An LSS was successfully developed on the basis of the model, in which one sample is collected immediately before the start of an infusion and the second is taken at the end of infusion.
A two-compartment population PK model successfully describes HuHMFG1 behaviour. The model suggests using a fixed dose of HuHMFG1, which would simplify dosing. The model could be used to optimise dose level and dosing schedule if more data on the correlation between exposure and efficacy become available from future studies. The derived LSS could optimise further PK assessment of this antibody.
HuHMFG1; AS1402; population pharmacokinetic; antibody; linear two-compartment; breast cancer
Dystonia is characterised by two main pathophysiological abnormalities: reduced excitability of inhibitory systems at many levels of the sensorimotor system, and increased plasticity of neural connections in sensorimotor circuits at a brainstem and spinal level. A surprising finding in two recent papers has been the fact that abnormalities of inhibition similar to those in organic dystonia are also seen in patients who have psychogenic dystonia. To try to determine the critical feature that might separate organic and psychogenic conditions, we investigated cortical plasticity in a group of 10 patients with psychogenic dystonia and compared the results with those obtained in a matched group of 10 patients with organic dystonia and 10 healthy individuals. We confirmed the presence of abnormal motor cortical inhibition (short interval intracortical inhibition, SICI) in both organic and psychogenic groups. However, we found that plasticity (paired associative stimulation, PAS) was abnormally high only in the organic group, while there was no difference between the plasticity measured in psychogenic patients and healthy controls. We conclude that abnormal plasticity is a hallmark of organic dystonia; furthermore it is not a consequence of reduced inhibition since the latter is seen in psychogenic patients who have normal plasticity.
associative plasticity; organic dystonia; psychogenic dystonia; paired associative stimulation; transcranial magnetic stimulation
In the title compound [systematic name: 1-(3-phenylprop-2-enoyl)thiourea], C10H10N2OS, the acetylthiourea fragment and the phenyl ring adopt an E configuration. The roughly planar but-2-enoylthiourea fragment [maximum deviation = 0.053 (3) Å] forms a dihedral of 10.54 (11)° with the phenyl ring. An intramolecular N—H⋯O hydrogen bond generates an S(6) ring. In the crystal, molecules are linked into sheets parallel to (100) by N—H⋯S hydrogen bonds.
In the title compound, C14H16N2O3S, the phenyl ring and the ethyl 2-(3-formylthioureido)acetate fragment adopt an E configuration with respect to the C=C bond. An intramolecular N—H⋯O hydrogen bond generating an S(6) ring motif is observed. In the crystal, molecules are linked by N—H⋯S, C—H⋯S and C—H⋯O hydrogen bonds, forming sheets lying parallel to the ab plane.
In the title compound, C13H14N2O3S, the methyl 2-(3-formylthioureido)acetate fragment and the phenyl ring adopt an E configuration. The molecule exhibits an intramolecular N—H⋯O hydrogen bond, which completes a six-membered ring. The crystal packing is stabilized by intermolecular N—H⋯S contacts, generating a two-dimensional hydrogen-bonding network.
The molecule of the title compound, C22H18N4O2S2, lies across a crystallographic inversion centre. The central benzene ring forms dihedral angles of 29.39 (9) and 79.11 (12)°, respectively, with the thiourea unit and the terminal phenyl ring. Intramolecular N—H⋯O hydrogen bonds generate two S(6) ring motifs. In the crystal, molecules are linked into chains along  by intermolecular N—H⋯S hydrogen bonds.
The expression of EGFR and p53 has not been adequately studied as a prognostic tool in urinary bladder tumors. We analyzed 74 bladder cancer samples from Egypt for EGFR and p53 expression using immunohistochemistry. The tumors were of different histological types, grades and clinical stages, and with established lymph node status. Almost 61% of the tumors showed positive membranous EGFR expression and 74.3% had positive nuclear staining of p53. Analysis of correlation of the IHC staining with clinical variables showed a significant correlation only between EGFR expression and histological type (p=0.002, ANOVA), in that the expression was higher in squamous cell carcinomas than in other histological types. There were no significant correlations between p53 or EGFR with the other clinicopathological variables, including age, sex, staging, grading, and lymph node status. Further studies are needed to determine if EGFR and p53 might be used as prognostic tools in bladder cancer.
Bladder cancer; p53; EGFR; Immunohistochemistry; Clinical data
In the title compound, C11H12N2O3S, the methyl acetate and benzoyl groups adopt a cis-trans configuration with respect to the thiono S atom across the C—N bonds. An intramolecular N—H⋯O hydrogen bond is observed. In the crystal packing, molecules are linked by intermolecular N—H⋯S and C—H⋯O hydrogen bonds to form a two-dimensional network lying parallel to (101).
The near exclusive use of praziquantel (PZQ) for treatment of human schistosomiasis has raised concerns about the possible emergence of drug-resistant schistosomes.
We measured susceptibility to PZQ of isolates of Schistosoma mansoni obtained from patients from Kisumu, Kenya continuously exposed to infection as a consequence of their occupations as car washers or sand harvesters. We used a) an in vitro assay with miracidia, b) an in vivo assay targeting adult worms in mice and c) an in vitro assay targeting adult schistosomes perfused from mice. In the miracidia assay, in which miracidia from human patients were exposed to PZQ in vitro, reduced susceptibility was associated with previous treatment of the patient with PZQ. One isolate (“KCW”) that was less susceptible to PZQ and had been derived from a patient who had never fully cured despite multiple treatments was studied further. In an in vivo assay of adult worms, the KCW isolate was significantly less susceptible to PZQ than two other isolates from natural infections in Kenya and two lab-reared strains of S. mansoni. The in vitro adult assay, based on measuring length changes of adults following exposure to and recovery from PZQ, confirmed that the KCW isolate was less susceptible to PZQ than the other isolates tested. A sub-isolate of KCW maintained separately and tested after three years was susceptible to PZQ, indicative that the trait of reduced sensitivity could be lost if selection was not maintained.
Isolates of S. mansoni from some patients in Kisumu have lower susceptibility to PZQ, including one from a patient who was never fully cured after repeated rounds of treatment administered over several years. As use of PZQ continues, continued selection for worms with diminished susceptibility is possible, and the probability of emergence of resistance will increase as large reservoirs of untreated worms diminish. The potential for rapid emergence of resistance should be an important consideration of treatment programs.
The emergence of drug resistant pathogens is a great challenge to the control of infectious diseases. Schistosomiasis is one of the world's greatest neglected tropical diseases, and it is primarily controlled with the drug praziquantel. This drug is often used by repeatedly treating patients to maintain reduced worm burdens, an ideal situation to encourage the evolution of resistant worms. Although drug based control programs are increasing, monitoring efforts for drug resistance remain rare. We measured drug susceptibility of schistosomes from a cohort of patients in Kenya who are enrolled in a longitudinal study in which they are repeatedly treated with praziquantel. We found that schistosomes from previously treated patients were significantly less susceptible than those that were not. Also, schistosomes derived from a single patient who had been treated with praziquantel 18 times showed marked resistance. Although the findings of this study indicated that reduced drug susceptibility occurs in this population of schistosomes, this trait does not seem to be spreading widely or creating clinical levels of resistance. We hypothesize that the trait remains at low frequency because of the large population of schistosomes that are not exposed to the drug and/or potential fitness costs associated with reduced susceptibility.
To determine the epidemiology of Crohn's disease (CD) in an outpatient clinic and compare it with data previously reported from different centers in the Kingdom of Saudi Arabia and outside.
Materials and Methods:
The medical records of all patients with CD seen in the clinic in the period from January 1993 through December 2007 were reviewed. The demographic, clinical data and methods of diagnosis were retrieved.
Over a period of 15 years, we saw 133 Saudi patients with CD. They were predominantly young, with a median age of 26.2 years and male preponderance (2.3:1). The final diagnosis was established within 1 week of presentation in 47% of the patients. The leading symptoms were abdominal pain (88%), diarrhea (70%), bloating (61%), rectal bleeding (50%), weight loss (33%), constipation (24%) and perianal disease (23%). The diagnosis was established by endoscopy and histopathology. Ileocecal involvement was encountered in 40% of the patients.
From the current study, it is obviously possible to diagnose a large proportion of patients with CD in a gastroenterology outpatient clinic. The data revealed a strikingly increased incidence of CD in a mainly young Saudi population in the past few years.
Crohn's disease; increasing trend; Saudi Arabia
In the title compound, C14H18N2O3S, the butyl acetate fragment and the benzoyl group adopt a cis–trans configuration, respectively, with respect to the thiono S atom across the C—N bonds. In the crystal packing, the molecules are linked by intermolecular N—H⋯O and C—H⋯O hydrogen bonds to form a one-dimensional chain along the c axis. The terminal butyl C atom is disordered with occupancies 0.82 (2)and 0.18 (2).
The title compound, C13H16N2O3S, is a thiourea derivative with benzoyl and propoxycarbonylmethyl groups attached to the two terminal N atoms. These groups adopt trans and cis configurations, respectively, with respect to the S atom across the thiourea C—N bonds. The compound crystallizes in the P21/c space group with Z = 8, resulting in two unique molecules in the asymmetric unit linked by C—H⋯S and C—H⋯O hydrogen bonds, forming a one-dimensional zigzag chain along the c axis.
The title compound, C12H14N2O3S, adopts a cis–trans geometry of the thiourea group and is stabilized by intramolecular hydrogen bonds between the carbonyl O atoms and the H atom of the thioamide group and by a C—H⋯S interaction. Molecules are linked by two intermolecular hydrogen bonds (C—H⋯O and N—H⋯O), forming a one-dimensional chain parallel to the c axis.
Schistosoma mansoni exists in a complex environmental milieu that may select for significant evolutionary changes in this species. In Kenya, the sympatric distribution of S. mansoni with S. rodhaini potentially influences the epidemiology, ecology, and evolutionary biology of both species, because they infect the same species of snail and mammalian hosts and are capable of hybridization.
Over a 2-year period, using a molecular epidemiological approach, we examined spatial and temporal distributions, and the overlap of these schistosomes within snails, in natural settings in Kenya. Both species had spatially and temporally patchy distributions, although S. mansoni was eight times more common than S. rodhaini. Both species were overdispersed within snails, and most snails (85.2% for S. mansoni and 91.7% for S. rodhaini) only harbored one schistosome genotype. Over time, half of snails infected with multiple genotypes showed a replacement pattern in which an initially dominant genotype was less represented in later replicates. The other half showed a consistent pattern over time; however, the ratio of each genotype was skewed. Profiles of circadian emergence of cercariae revealed that S. rodhaini emerges throughout the 24-hour cycle, with peak emergence before sunrise and sometimes immediately after sunset, which differs from previous reports of a single nocturnal peak immediately after sunset. Peak emergence for S. mansoni cercariae occurred as light became most intense and overlapped temporally with S. rodhaini. Comparison of schistosome communities within snails against a null model indicated that the community was structured and that coinfections were more common than expected by chance. In mixed infections, cercarial emergence over 24 hours remained similar to single species infections, again with S. rodhaini and S. mansoni cercarial emergence profiles overlapping substantially.
The data from this study indicate a lack of obvious spatial or temporal isolating mechanisms to prevent hybridization, raising the intriguing question of how the two species retain their separate identities.
One of the world's most prevalent neglected diseases is schistosomiasis, which infects approximately 200 million people worldwide. Schistosoma mansoni is transmitted to humans by skin penetration by free-living larvae that develop in freshwater snails. The origin of this species is East Africa, where it coexists with its sister species, S. rodhaini. Interactions between these species potentially influence their epidemiology, ecology, and evolutionary biology, because they infect the same species of hosts and can hybridize. Over two years, we examined their distribution in Kenya to determine their degree of overlap geographically, within snail hosts, and in the water column as infective stages. Both species were spatially and temporally patchy, although S. mansoni was eight times more common than S. rodhaini. Both species overlap in the time of day they were present in the water column, which increases the potential for the species to coinfect the same host and interbreed. Peak infective time for S. mansoni was midday and dawn and dusk for S. rodhaini. Three snails were coinfected, which was more common than expected by chance. These findings indicate a lack of obvious isolating mechanisms to prevent hybridization, raising the intriguing question of how the two species retain separate identities.