Biokinetic aspects for biocatalytic remediation of xenobiotics polluted seawater.

AIMS: This research was conducted to investigate the biocatalytic remediation of xenobiotics polluted seawater using two biocatalysts; whole bacterial cells of facultative aerobic halotolerant Corynebacterium variabilis Sh42 and its extracted crude enzymes. METHODS AND RESULTS: One-Factor-at-A-Time technique and statistical analysis were applied to study the effect of initial substrate concentrations, pH, temperature, and initial biocatalyst concentrations on the batch biocatalytic degradation of three xenobiotic pollutants (2-hydroxybiphenyl (2-HBP), catechol and benzoic acid) in artificial seawater (salinity 3·1%). HPLC and gas-chromatography mass spectroscopy analyses were utilized to illustrate the quantitative removal of the studied aromatic xenobiotic pollutants and their catabolic pathway. The results revealed that the microbial and enzymatic cultures followed substrate inhibition kinetics. Yano and Koga's equation showed the best fit for the biokinetic degradation rates of 2-HBP and benzoic acid, whereas Haldane biokinetic model adequately expressed the specific biodegradation rate of catechol. The biokinetic results indicated the good efficiency and tolerance of crude enzyme for biocatalytic degradation of extremely high concentrations of aromatic pollutants than whole C. variabilis Sh42 cells. The monitored by-products indicated that the catabolic degradation pathway followed an oxidation mechanism via a site-specific monooxygenase enzyme. Benzoic acid and catechol were identified as major intermediates in the biodegradation pathway of 2-HBP, which were then biodegraded through meta-cleavage to 2-hydroxymuconic semialdehyde. With time elapsed, the semialdehyde product was further biodegraded to acetaldehyde and pyruvic acid, which would be further metabolized via the bacterial TCA cycle. CONCLUSION: The batch enzymatic bioreactors performed superior-specific biocatalytic degradation rates for all the studied xenobiotic pollutants. SIGNIFICANCE AND IMPACT OF THE STUDY: The enzymatic system of C. variabilis Sh42 is tolerable for toxic xenobiotics and different physicochemical environmental parameters. Thus, it can be recommended as an effective biocatalyst for biocatalytic remediation of xenobiotics polluted seawater.

Early administration of phosphodiesterase 5 inhibitors after induction of diabetes in a rat model may prevent erectile dysfunction.

BACKGROUND: The possible role of phosphodiesterase 5 inhibitors (PDE5Is) in prevention of negative effect of diabetes mellitus (DM) on erectile function is not well settled. OBJECTIVES: To investigate the effect of early administration of vardenafil on erectile function, cavernosal structure, and genes expression in a rat model of DM. MATERIALS AND METHODS: This experimental study was carried out at Suez Canal University's research laboratory. This study was conducted on a total of 60 adult male Albino Wistar rats, aged 60-80 days and weighing an average of 200 g. Rats were equally divided into six groups of 10 rats each: Group I (sham); Group II (DM with no treatment); Groups III, IV, V, and VI received vardenafil started at day 1, week 4, week 8, and week 12 after induction of DM, respectively. Functional study assessment of all groups was performed before euthanization, and then tissues were harvested for histopathological, ultrastructural, and molecular examinations. RESULTS: There was a significant difference of intracavernosal pressure between early (94 ± 2.18) and late (40.5 ± 1.94) treatment groups (p = 0.011). Histopathological and ultrastructural changes of DM with no treatment and late treatment groups showed distorted cavernous architecture and extensive fibrosis. There was significant difference of smooth muscle to collagen ratio between early and late treatment groups (p = 0.035). There was significant upregulation of nNOS(p = 0.021) and iNOS (p = 0.047) in early vs. late treatment group. The difference was insignificant in eNOS (p = 0.386) or TGF-ß1(p = 0.149). DISCUSSION AND CONCLUSION: Early treated rats with vardenafil had preserved erection and normal cavernosal structure, ultrastructure and gene expression of iNOS, nNOS, eNOS, and TGF-ß1. Quantification of gene expression would improve our knowledge regarding cytokines expression and molecular background of DM-associated ED. Clinical application of this result may encourage early administration of PDE5I to prevent deleterious effects of DM on erectile function in newly diagnosed DM patients with probable uncontrolled blood glucose.

Novel mycosynthesis of cobalt oxide nanoparticles using Aspergillus brasiliensis ATCC 16404-optimization, characterization and antimicrobial activity.

AIMS: Investigate the capability of Aspergillus brasiliensis ATCC 16404 to mycosynthesize Co3 O4 -NPs. METHODS AND RESULTS: Mycelial cell-free filtrate of A. brasiliensis ATCC 16404 was applied for mycosynthesis of Co3 O4 -NPs. The preliminary indication for the formation of Co3 O4 -NPs was the change in colour from yellow to reddish-brown. One-factor-at a time-optimization technique was applied to determine the optimum physicochemical conditions required for the mycosynthesis of Co3 O4 -NPs and they were found to be: 72 h for reaction time, pH 11, 30°C, 100 rev min-1 for shaking speed in the darkness using 4 mmol l-1 of CoSO4. 7H2 O and 5·5% of A. brasiliensis dry weight mycelium (w/v). The mycosynthesized Co3 O4 -NPs were characterized using various techniques: spectroscopy including UV/Vis spectrophotometry, dynamic light scattering (DLS), zeta potential measurement, energy-dispersive X-ray analysis, Fourier transform infrared spectroscopy and X-ray diffraction; and vibrating sample magnetometry and microscopy including field emission scanning electron microscopy and high-resolution transmission electron microscopy. Spectroscopic techniques confirmed the formation of Co3 O4 -NPs and the microscopic ones confirmed the shape and size of the mycosynthesized Co3 O4 -NPs as quasi-spherical shaped, monodispersed nanoparticles with a nano size range of 20-27 nm. The mycosynthesized Co3 O4 -NPs have excellent magnetic properties and exhibited a good antimicrobial activity against some pathogenic micro-organisms. CONCLUSION: Ferromagnetic Co3 O4 -NPs with considerable antimicrobial activity were for the first time mycosynthesized. SIGNIFICANCE AND IMPACT OF THE STUDY: The use of fungi as potential bionanofactories for mycosynthesis of nanoparticles is relatively a recent field of research with considerable prospects.

Efficacy of direct-acting anti-viral therapy on chronic, naïve hepatitis C virus patients of Punjab, Pakistan: a cross-sectional study.

The success of interferon-free regimens using new direct-acting antiviral (DAA) is a revolution and major breakthrough in the development of new therapeutic options against hepatitis C virus (HCV). Accumulating evidence suggest sustained virological response (SVR) with DAA in 95% of patients. To date, however, there are very few data related to efficacy of DAA in the Pakistani population. We aimed to investigate the efficacy of sofosbuvir-based regimen among Pakistani population. A total of 1,913 patients who attained SVR24 after being treated with sofosbuvir and ribavirin from August 2015 to March 2017 were enrolled in this study. We analyzed the demographic, clinical and virological data and screened all patients for HCV in March 2017 to evaluate the response rate. We found an overall response rate of 92.8%. In addition, we also observed lower response rates among older patients. It can be inferred that a large proportion of patients achieved SVR after treatment with sofosbuvir-based regimen.

Physiochemical properties of Trichoderma longibrachiatum DSMZ 16517-synthesized silver nanoparticles for the mitigation of halotolerant sulphate-reducing bacteria.

AIMS: In order to efficiently control the corrosive sulphate-reducing bacteria (SRB), the main precursor of the microbial influenced corrosion (MIC) in oil industry, the ability of Trichoderma longibrachiatumDSMZ 16517 to synthesize silver nanoparticles (AgNPs) was investigated and their biocidal activity against halotolerant SRB was tested. METHODS AND RESULTS: The mycelial cell-free filtrate (MCFF) bioreduced the silver ions (Ag+ ) to their metallic nanoparticle state (Ag0 ), which was presumptively indicated by the appearance of a dark brown suspension and confirmed by the characteristic absorbance of AgNPs at ʎ422nm . One-factor-at-a-time technique was used to optimize the effect of temperature, time, pH, fungal biomass and silver nitrate concentrations, stirring rates and dark effect. The dynamic light scattering (DLS) analysis revealed average AgNPs size and zeta potential values of 17·75 nm and -26·8 mV, respectively, indicating the stability of the prepared AgNPs. The X-ray diffraction (XRD) pattern assured the crystallinity of the mycosynthesized AgNPs, with an average size of 61 nm. The field emission scanning electron microscope (FESEM) and high-resolution transmission electron microscope (HRTEM) showed nonagglomerated spherical, triangular and cuboid AgNPs ranging from 5 to 11 ± 0·5 nm. The Fourier transform infrared spectroscopy (FT-IR) analysis of the mycosynthesized AgNPs affirmed the role of MCFF as a reducing and capping agent. A preliminary suggested mechanism for mycosynthesis of AgNPs was elucidated. The mycosynthesized AgNPs expressed high biocidal activity against a halotolerant planktonic mixed culture of SRB. The HRTEM analysis showed a clear evidence of an alteration in cell morphology, a disruption of SRB cell membranes, a lysis in cell wall and a cytoplasmic extraction after treatment with AgNPs. This confirmed the bactericidal effect of the mycosynthesized AgNPs. CONCLUSION: The biocidal activity of the mycosynthesized AgNPs against halotolerant planktonic SRB makes it an attractive option to control MIC in the petroleum industry. SIGNIFICANCE AND IMPACT OF THE STUDY: This research provides a helpful insight into the development of a new mycosynthesized biocidal agent against the corrosive sulphate-reducing bacteria.

Synthesis of recyclable carbon/lignin biocomposite sorbent for in-situ uptake of BTX contaminants from wastewater.

In this work, both palm-date pits and pulping black liquor industrial wastes were recycled as low-cost starting materials for the production of three series of granule activated carbon (gAC)/Kraft lignin (KL) (gAC/KLx, x = 33, 50 and 67%) biocomposites using a one-pot solid-state method. The gAC/KLx biocomposites with defined characteristics were examined towards batch adsorption of BTX (Benzene, Toluene, and Xylene) in multi-solute salty wastewaters. Optimization of adsorption performances under different experimental conditions were carried out using high performance liquid chromatography (HPLC). Adsorption modeling versus contact time (0-12 h) and BTX concentrations (150-2250 mg/L) were examined using non-linear forms of nine kinetic and five isotherm equations to best understand gAC/KL0.5 suitability for BTX sorption/recovery processing. Accordingly, the gAC/KLx at KL blended ratio of 50% was found to be the topmost to achieve the highest BTX capacity even at broad ranges of water salinity (0-100 g/L) and pH (3-9) values. The adsorption mechanism found to best described by physico-sorption (E ≈ 0.12-1.38 kJ/mol) via the hydrophobic interaction and diffusion mechanisms. In respect to gAC/KL0.5 affinities, the sorption capacity followed the descending sequence of X ≥ T > B. Particularly, the maximum theoretical BTX capacity using the best fitted Langmuir-Freundlich model (L-FM) for gAC/KL0.5 was found to be slightly higher than obtained by gAC (363.9 and 360.1 mg/g, respectively), along with higher initial sorption (h) rate (≈742.47 mg/g.h) than of gAC (≈559.85 mg/g.h) and KL (≈22.22 mg/g.h). Batch BTX sorption/recovery processes and estimated cost suggested the effective utilization of gAC/KL0.5 as a promising in-expensive sorbent (0.31 ±â€¯0.05 US$/kg) for commercial decontamination of petroleum hazardous (BTX) pollutants from wastewaters up to five reuse cycles.

Statistical enhancement of lipase extracellular production by Bacillus stratosphericus PSP8 in a batch submerged fermentation process.

AIM: The aim of this study was to isolate and identify lipolytic bacteria. Perform a statistical stepwise physicochemical optimization for maximum production of extracellular lipase and its validation in a bioreactor. METHODS AND RESULTS: Several lipolytic bacteria were isolated from petroleum hydrocarbon-polluted soil. The strain expressing the highest lipase activity (47 U ml-1 ) was genetically identified as Gram-positive Bacillus stratosphericus PSP8 (NCBI GenBank accession no. MH120423). The response surface methodology (RSM)-central composite face centre (CCF) design of experiments was performed based on the preselected levels of the studied parameters obtained from the performed one-factor-at-a-time sequential experiments. A second-order polynomial model was predicted and improved the lipase production by approximately 1·6-fold. Preliminary scaling up of the validated optimized process was carried out in a batch 10-l stirred tank bioreactor, applying the optimum predicted operating conditions; pH 6·98, 34·8°C, 2·2 × 106 cells per ml, 200 rev min-1 , 4·82 g l-1 tributyrine concentration, 1% sucrose and 0·1% yeast extract. This yielded 89 U ml-1 at the late log phase of bacterial growth (48 h). Logistic kinetic model effectively characterized the submerged fermentation process, and the maximum specific growth and lipase production rates were estimated to be 0·338 and 0·164 h-1 respectively. CONCLUSIONS: The mesophilic and neutrophilic B. stratosphericus PSP8 isolated from petroleum hydrocarbon-contaminated soil is a proper source of lipase. The closeness of the predicted response with that of the experimental value and the enhancement of lipase productivity in fermenter scale by approximately 1·9-fold, showed that statistically optimized design can be used in order to improve the lipase production to meet the increasing demand. SIGNIFICANCE AND IMPACT OF THE STUDY: The RSM-CCF statistical optimization is useful for optimizing a large number of variables and studying their interactive effects on extracellular lipase production.

Batch bioethanol production via the biological and chemical saccharification of some Egyptian marine macroalgae.

AIMS: Marine seaweeds (macroalgae) cause an eutrophication problem and affects the touristic activities. The success of the production of the third-generation bioethanol from marine macroalgae depends mainly on the development of an ecofriendly and eco-feasible pretreatment (i.e. hydrolysis) technique, a highly effective saccharification step and finally an efficient bioethanol fermentation step. Therefore, this study aimed to investigate the potentiality of different marine macroalgal strains, collected from Egyptian coasts, for bioethanol production via different saccharification processes. METHODS AND RESULTS: Different marine macroalgal strains, red Jania rubens, green Ulva lactuca and brown Sargassum latifolium, have been collected from Egyptian Mediterranean and Red Sea shores. Different hydrolysis processes were evaluated to maximize the extraction of fermentable sugars; thermochemical hydrolysis with diluted acids (HCl and H2 SO4 ) and base (NaOH), hydrothermal hydrolysis followed by saccharification with different fungal strains and finally, thermochemical hydrolysis with diluted HCl, followed by fungal saccharification. The hydrothermal hydrolysis of S. latifolium followed by biological saccharification using Trichoderma asperellum RM1 produced maximum total sugars of 510 mg g-1 macroalgal biomass. The integration of the hydrothermal and fungal hydrolyses of the macroalgal biomass with a separate batch fermentation of the produced sugars using two Saccharomyces cerevisiae strains, produced approximately 0·29 g bioethanol g-1 total reducing sugars. A simulated regression modelling for the batch bioethanol fermentation was also performed. CONCLUSIONS: This study supported the possibility of using seaweeds as a renewable source of bioethanol throughout a suggested integration of macroalgal biomass hydrothermal and fungal hydrolyses with a separate batch bioethanol fermentation process of the produced sugars. SIGNIFICANCE AND IMPACT OF THE STUDY: The usage of marine macroalgae (i.e. seaweeds) as feedstock for bioethanol; an alternative and/or complimentary to petro-fuel, would act as triple fact solution; bioremediation process for ecosystem, renewable energy source and economy savings.

Testosterone level and endothelial dysfunction in patients with vasculogenic erectile dysfunction.

The association between endothelial dysfunction and late onset hypogonadism (LOH) in patients with vasculogenic erectile dysfunction (ED) is not yet well settled. Our objective was to assess the association between LOH and endothelial dysfunction in patients with vasculogenic ED. Throughout 2014-2015 a total of 90 men were enrolled in this cross-sectional observational study. Of them 60 patients with a clinical diagnosis of ED were further subdivided into two equal groups: patients with vasculogenic ED and LOH (A); patients with vasculogenic ED and euogonadal (B). Thirty age-matched men with no ED or hypogonadism were enrolled as control group (C). All patients were subjected to detailed medical and sexual history, total testosterone (TT), calculated free (FT) and bioavailable testosterone (BT), flow cytometric evaluation for endothelial progenitor cells (EPCs) (CD45negative/CD34positive/CD144positive) and endothelial microparticles (EMPs) (CD45negative/CD144positive/annexin V positive). The mean age ± SD of the three groups A, B and C were 51.3 ± 11.1, 53.6 ± 10.6 and 48.3 ± 5 years, respectively, with insignificant age differences (p = 0.089). The diagnostic criteria of LOH were adapted according to European male aging study, 2010. The means of TT(ng/mL) were 2.32 ± 0.21, 6.43 ± 0.36 and 5.37 ± 0.30 in groups A, B and C, respectively. There were highly significant differences between group A and groups B and C (p < 0.001 for each). The means of EPCs were 0.43 ± 0.070, 0.22 ± 0.05 and 0.032 ± 0.013 in groups A, B and C, respectively. The means of EMPs were 0.15 ± 0.029, 0.056 ±  .013 and 0.014 ± 0.002 in groups A, B and C, respectively. There were significant differences between group C and groups A and B (p < 0.05 for each). This study clearly demonstrated that there is a significant association between LOH and the higher expression of EPCs and EMPs in patients with vasculogenic ED.

Assessment of seminal mast cells in infertile men with varicocele after surgical repair.

This study aimed to assess seminal mast cells in infertile men associated with varicocele (Vx) pre- and post-surgical repair. Forty-five infertile men associated with Vx were subjected to history taking and clinical examination. In addition, semen parameters and seminal mast cells stained with 1% toluidine blue were estimated pre-varicocelectomy and three months post-varicocelectomy. Vx surgical repair revealed a significant improvement in the mean sperm concentration, progressive sperm motility, total sperm motility and sperm abnormal morphology and a significant decrement in seminal mast cells (mean ± SD, 3.56 ± 2.23 cells per high-power field (HPF) vs. 2.22 ± 1.06 cells per HPF, p = .01). The pre-operative mean mast cell count demonstrated significant increases in cases with Vx grade III compared with other Vx grades and in cases with bilateral Vx compared with unilateral Vx cases. Seminal mast cells demonstrated a significant correlation with sperm concentration, progressive sperm motility and total sperm motility and a nonsignificant correlation with age and sperm abnormal morphology. It is concluded that seminal mast cells decrease significantly in infertile men with Vx after surgical repair showing a significant negative correlation with sperm concentration, progressive sperm motility and total sperm motility.

Association between tumour necrosis-α gene polymorphisms and acne vulgaris in a Pakistani population.

BACKGROUND: The cytokine tumour necrosis factor (TNF)-α is a well-studied potent candidate mediator that is systemically involved in a variety of inflammatory diseases. Several single nucleotide polymorphisms (SNPs) of the TNF-α gene have been studied with regard the pathogenesis of acne vulgaris, but the results have been inconclusive. AIM: This case-control study investigated the association of the TNF -308 G>A and -238 G>A SNPs with acne vulgaris in a high-risk Pakistani population. METHODS: In total, 160 healthy controls and 140 patients with acne were enrolled in this study. Polymorphisms were determined by PCR and restriction fragment length polymorphism analysis. RESULTS: Our data showed that the TNF -308 G>A and TNF -238 G>A SNPs were present at a significantly higher rate in cases than in controls (P < 0.01 and P < 0.02; respectively). There was a significant difference between the G and A alleles from patients with acne and controls for -308 G>A (OR = 1.5, 95% CI = 1.07-2.19, P < 0.02) and -238 G>A (OR=1.6, 95% CI = 1.06-2.44, P = 0.02) genotype. Moreover, the severity of acne was significantly associated with TNF genotype (TNF -308 G>A: χ² = 34.6, P < 0.001; TNF -238 G>AL χ² = 12.9, P < 0.01). CONCLUSION: Our data suggest that the TNF -308 G>A and TNF -238 G>A SNPs may contribute to the pathogenesis of acne in the study population. Furthermore, patients with severe acne showed an increased frequency of mutant TNF genotypes at -308 and -238 compared with patients with less severe acne.

The interleukin-6 and interleukin-1A gene promoter polymorphism is associated with the pathogenesis of acne vulgaris.

Acne vulgaris is a skin disorder with a complex pathogenesis. Better treatment strategies require comprehensive knowledge of molecular factors contributing to the acne pathophysiology. Recent studies are focused on investigating the influence of inflammatory cytokines on the disease. This case-control study investigated the association of IL-6-572 G/C and IL-1A-889 C/T gene polymorphisms with acne in a Pakistani population. Pakistani subjects (380 healthy controls and 430 acne patients) were enrolled in this study. Polymorphism in the promoter region of IL-6-572 and IL-1A-889 was determined by polymerase chain reaction and restriction fragment length polymorphism. The IL-6-572 and IL-1A-889 variant genotypes were significantly associated with the acne pathogenesis. The IL-6-572C and the IL-1A-889T alleles were significantly high in the patient vs. control group (p < 0.0001 for both loci). The IL-6-572 G/C and IL-1A-889 C/T variant allele haplotypes showed significantly high prevalence in patients with acne; G-T (P = 0.0014), C-C (P < 0.0001), and C-T (P < 0.0001). This is the first report on the association between the IL-6-572 G/C polymorphism and acne among any population. The IL-1A-889 C/T polymorphism is also significantly linked with acne in the study population; the -889 C/T association with acne has been reported in one ethnic group previously. Our findings suggest that the IL-6-572C and IL-1A-889T alleles may contribute to the pathogenesis of acne in a Pakistani population. Further studies are required to verify these findings in other populations.

Cardiac hydatid disease, case report, and review of literature.

Cardiac Hydatidosis is a rare but potentially very serious complication of hydatid disease. It is a diagnostic and therapeutic challenge due to the variability of signs and symptoms at presentation. A case of disseminated hydatidosis, affecting the heart muscle, which failed to surgical evacuation and followed by spread to the brain and elsewhere in the body, is presented, discussed, together with a review of the literature. The disease, hydatididosis, remains a challenge even in our days. Systematic radical control in the Middle East is required. Alternative surgical options include heart transplantation when the disease affects the heart muscles and there is more than one cyst which fails to surgical evacuation.

Primary cytomegalovirus infection in pregnant Egyptian women confirmed by cytomegalovirus IgG avidity testing.

OBJECTIVE: To determine the frequency of primary cytomegalovirus (CMV) infection in pregnant Egyptian women using CMV IgG avidity testing. SUBJECTS AND METHODS: A cross-sectional study was conducted at Suez Canal University Hospital, Ismailia, Egypt. A total of 546 pregnant women, presenting for routine antenatal screening, were tested for CMV IgG and IgM using a commercially available enzyme-linked immunosorbent assay (ELISA). Sera from CMV IgM-positive women were tested by CMV IgG avidity assay. RESULTS: All the 546 pregnant women were seropositive for anti-CMV IgG. Of the 546 women, 40 (7.3%) were positive or equivocal for IgM antibodies. All sera from the 40 women (IgG+/IgM+) showed a high or intermediate CMV IgG avidity index. Of the 40 women, 23 (57.5%) were in the second or third trimesters of pregnancy and had their first-trimester blood retrieved, and the tested CMV IgG avidity assay showed a high avidity index. CONCLUSION: Women who were IgM positive had no primary CMV infection in the index pregnancy as evidenced by the high CMV IgG avidity testing.

Calibration of cylindrical detectors using a simplified theoretical approach.

The calibration of cylindrical detectors using different types of radioactive sources is a matter of routine. The most accurate method, that of experiment, is limited by several factors when the energy interval is broad, requiring a relatively large number of primary standards, implying considerable investment of money and time. Several other techniques can be used instead, including Monte Carlo simulations and semi-empirical methods. Calculations based on the first technique require good definition of the geometry and materials, including the dead layer and window thickness together with an accurate set of cross-sections. The second technique requires two different types of experimental input, the first being from use of sources emitting cascade gamma rays and the second from use of sources emitting isolated gamma rays in order to cover the wide energy range and provide coincidence-summing corrections, respectively. Here, we introduce a new theoretical approach based on the Direct Statistical method proposed by Selim and Abbas to calculate the total and the full-energy peak (photopeak) efficiencies for both point and thin circular disk sources for scintillation and semiconductor detectors. The present method combines calculation of the average path length covered by the photon inside the detector active volume and the geometrical solid angle Omega, to obtain a simple formula for the different efficiencies. Results from the present model were tested against data sets obtained with previous treatments in order to underline how simple and fast our calculations are.

Immunogenicity and safety of autoclaved Leishmania major plus BCG vaccine in healthy Sudanese volunteers.

In a longitudinal study in the epidemiology of Leishmania donovani infection in an endemic focus in eastern Sudan, we observed that previous exposure or infection with Leishmania major appeared to protect against visceral leishmaniasis caused by L. donovani. We therefore conducted a study to test the safety and immunogenicity of a vaccine consisting of autoclaved L. major (ALM) plus BCG in inducing protection in vaccinated individuals. Leishmanin-negative healthy Sudanese volunteers were enrolled in the study and were divided into three groups: group (A) received ALM+BCG, group (B) received BCG alone, and group (C) received the vaccine diluent. The subjects were examined for their clinical and immunological responses before intervention, following intervention and 6-8 weeks after vaccination. Vaccinated subjects (group A) developed localized reactions at the sites of vaccine inoculation that ulcerated and healed within 4-6 weeks; 61.6% of them converted to leishmanin reactive following vaccination. Only one subject in group (C) became leishmanin-positive. A total 76.9% of the vaccinated volunteers in group (A) produced significant levels of interferon-gamma in response to L. major antigen. The vaccine produced significant cellular immune responses that may protect against natural challenge. None of the groups had systemic reactions and all the reactions observed in the vaccinated group were comparable with the BCG-vaccinated group.

Clinical, parasitological and immunological features of canal cleaners hyper-exposed to Schistosoma mansoni in the Sudan.

The present work was a longitudinal study on Schistosoma mansoni infection in occupationally hyperexposed canal cleaners in the Sudan and the influence of therapy on the parasitological and humoral immune parameters. Chronically infected canal cleaners (n = 28) were more resistant to reinfection (Fisher's exact test, P < 0.05) than newly recruited canal cleaners (n=17). Chronically infected canal cleaners had a significantly higher degree of Symmers' fibrosis (chi2 = 19.1, P < 0.0001), significantly larger portal vein diameter (P < 0.05) and enlarged spleen (chi2 = 4.2, P < 0.05) than recently infected, newly recruited canal cleaners. ELISA was used to detect IgG, IgA and IgM in response to whole worm homogenate (WWH) and cercarial homogenate (CH). Chronically infected canal cleaners had significantly higher IgG to WWH antigen than newly recruited canal cleaners and normally exposed individuals (P < 0.05), while both chronically infected and newly recruited canal cleaners had higher IgG levels to CH antigen than normally exposed individuals (P < 0.05). The newly recruited canal cleaners had a significantly higher IgM level to CH antigen than chronically infected canal cleaners (P < 0.05). The IgG level to WWH antigen increased significantly after treatment in newly recruited canal cleaners and normally exposed individuals (P < 0.05). The IgA level to CH antigen increased significantly after treatment in the chronically infected group (P < 0.05). Comparison of the serological parameters between the different study groups with regards to infection and treatment is discussed.