Potential role of CXCR4 in trastuzumab resistance in breast cancer patients.

Despite the efficacy of trastuzumab in treating HER2-positive breast cancer patients, a significant proportion of patients relapse after treatment. The role of C-X-C chemokine receptor type 4 (CXCR4) in trastuzumab resistance was studied only in cell lines and the underlying mechanisms remain largely unclear. This study investigated the role of CXCR4 in trastuzumab resistance in breast cancer patients and explored the possible underlying mechanisms. The study was performed retrospectively on tissue samples from 62 breast cancer patients including 42 who were treated with trastuzumab and chemotherapy and 20 who received chemotherapy alone in adjuvant setting. Expression levels of CXCR4 and its regulators hypoxia-inducible factor 1-alpha (HIF-1α), tristetraprolin (TTP), human antigen R (HuR), itchy E3 ubiquitin protein ligase (ITCH), miR-302a and miR-494 were determined and their associations with tumor recurrence and disease-free survival were analyzed. In trastuzumab-treated patients, high CXCR4 expression was associated with recurrence and was an independent predictor of progression risk after therapy. CXCR4 correlated positively with its transcriptional regulator, HIF-1α, and negatively with its post-translational regulator, ITCH. HIF-1α, HuR and ITCH were significantly associated with clinical outcome. In chemotherapy-treated patients, neither CXCR4 nor any of its regulators were associated with recurrence or predicted disease progression risk after chemotherapy. In conclusion, this study suggests a potential role for CXCR4 in recurrence after trastuzumab-based therapy in human breast cancer that could be mediated, at least in part, by hypoxia and/or decreased ubiquitination. These findings highlight the potential utility of CXCR4 as a promising target for enhancing trastuzumab therapeutic outcome.

Promising antiparasitic agents from marine sponges.

Parasitic diseases especially those prevail in tropical and subtropical regions severely threaten the lives of people due to available drugs found to be ineffective as several resistant strains have been emerged. Due to the complexity of the marine environment, researchers considered it as a new field to search for compounds with therapeutic efficacy, marine sponges represents the milestone in the discovery of unique compounds of potent activities against parasitic infections. In the present article, literatures published from 2010 until March 2021 were screened to review antiparasitic potency of bioactive compounds extracted from marine sponges. 45 different genera of sponges have been studied for their antiparasitic activities. The antiparasitic activity of the crude extract or the compounds that have been isolated from marine sponges were assayed in vitro against Plasmodium falciparum, P. berghei, Trypanosoma brucei rhodesiense, T. b. brucei, T. cruzi, Leishmania donovani, L. tropica, L. infantum, L. amazonesis, L. major, L. panamesis, Haemonchus contortus and Schistosoma mansoni. The majority of antiparastic compounds extracted from marine sponges were related to alkaloids and peroxides represent the second important group of antiparasitic compounds extracted from sponges followed by terpenoids. Some substances have been extracted and used as antiparasitic agents to a lesser extent like steroids, amino acids, lipids, polysaccharides and isonitriles. The activities of these isolated compounds against parasites were screened using in vitro techniques. Compounds' potent activity in screened papers was classified in three categories according to IC50: low active or inactive, moderately active and good potent active.

Cnidarians as a potential source of antiparasitic drugs.

New antiparasitic drugs are urgently required for treating parasitic infections. The marine environment has proven to be a valuable source of compounds with therapeutic properties against many diseases, including parasitic diseases. Cnidarian venoms are known for their toxicological properties and are candidates for developing medications. In this review, the antiparasitic properties of cnidarian toxins, discovered over the last two decades, were examined. A total of 61 cnidarian compounds from 18 different genera of cnidaria were studied for their antiparasitic activities. The assessed genera belonged mainly to three geographical areas: South America, North America, and Southeast Asia. The in vitro activities of crude extracts and compounds against a range of parasites including Plasmodium falciparum, Trypanosoma brucei gambiense, T. cruzi, T. congolense, Leishmania donovani, L. chagasi, L. braziliensis, and Giardia duodenalis are reviewed. The challenges involved in developing these compounds into effective drugs are discussed.

Seroprevalence and molecular characterization of Toxoplasma gondii infecting ruminants in the North-West of Egypt.

Toxoplasma gondii is a coccidian parasite known for its heavy toll on people and livestock. It can cause abortion and a variety of congenital diseases. The current study aimed to examine some seroprevalence and molecular attributes of T. gondii obtained from ruminants in the North-West of Egypt. Specimens were random selected from five different locations in Alexandria and Matrouh governorates. A total of 483 blood samples, collected from 96 mixed flocks, were screened for anti-T. gondii IgG antibodies using enzyme-linked immunosorbent assay (ELISA). The seropositive results were then confirmed using polymerase chain reaction (PCR) primers for the B1 and P30 genes. Specific PCR products were selected for sequencing and alignment against the GenBank, where phylogeny has been examined using the maximum likelihood, neighbor-joining, and maximum parsimony in MEGA6. ELISA confirmed the presence of T. gondii in 188 of the investigated samples (38.92%), indicating a higher prevalence in camels (64.51%) and sheep (43.75%) as compared to goats (27.93 %) and cattle (13.46%). PCR confirmed the presence of T. gondii-specific sequences in 159 seropositive specimens, with homology between 98.3 and 100%. The genetic distances between the investigated variants ranged from 0.1 to 0.9, and 7 single nucleotide polymorphisms (SNPs), were identified in the examined T. gondii specimens. The camel T. gondii parasite, isolated from Matrouh, showed a 100% homology with the most dangerous reference strains of T. gondii-RH in the GenBank. Our results showed that B1 and P30-specific PCR could detect T. gondii in blood samples more accurately than ELISA. In addition, the statistical analysis of our data indicated that species, age, sex, and animal location were all risk factors for toxoplasmosis. These findings are likely to boost disease control and help contain the spread of T. gondii infections.

The potential role of 2D-speckle tracking echocardiography for detecting left ventricular systolic dysfunction in patients with Parkinson's disease: a case control study.

BACKGROUND: The prevalence of heart failure among patients with Parkinson's disease (PD) was found to be twice that of the general population. The aim of this work is to evaluate the global left ventricular systolic function in patients with PD in comparison with healthy controls using speckle tracking echocardiography and to correlate the global left ventricular systolic function with both motor and cognitive functions in PD patients. METHODS: A case-control study was conducted on 40 patients diagnosed with PD and 40 healthy controls. Evaluation and staging of PD were performed using the Modified Hoehn and Yahr staging scale (H&Y staging) and Unified Parkinson's Disease Rating Scale (UPDRS). Cognitive assessment for PD patients was done using Parkinson's Disease - Cognitive Rating Scale (PD-CRS). Conventional and two-dimensional (2D) speckle-tracking strain echocardiography was done for both groups to assess the global left ventricular systolic function. RESULTS: There was a statistically significant difference between PD patients and controls regarding global longitudinal strain (p = 0.025), left ventricular end-diastolic dimension (p = 0.032), left ventricular end-systolic dimension (p = 0.003) and ejection fraction (p = 0.015). There were statistically significant negative correlations between both H&Y staging and UPDRS and both GLS (p ˂ 0.001, p ˂ 0.001) and EF (p = 0.017, p = 0.05). There were statistically significant positive correlations between PD-CRS and both GLS (p = 0.025) and EF (p = 0.012). CONCLUSION: PD patients were found to have significant subclinical left ventricular systolic dysfunction in comparison with healthy controls. Such dysfunction was correlated with the severity of the motor disability and cognitive impairment.

TH1/TH2 chemokines/cytokines profile in rats treated with tetanus toxoid and Euphorbia tirucalli.

Natural products, including their purified materials, play a remarkable role in drug development. The Euphorbiaceae family, mainly Euphorbia tirucalli, is used in some traditional medicine, and has evidence that its latex comprises immunomodulatory properties and cytokine production. This study aimed to measure the in vivo production of chemokines (IL-1α, IL-1ß, IL-12, and RANTES), TH1 cytokines (IFN-γ, TNF-α, GM-CSF, and IL-2) and TH2 cytokines (IL-4, IL-6, IL-10, and IL-13) in rats after treatments with ethanol latex extract of E. tirucalli. Vaccine treated and untreated rats were divided into seven groups to assess antimicrobial activities of the extracted components. After completion of the treatment schedule, blood was withdrawn and sera were collected. The results showed that the main component of the extract was a euphol compound. The extract showed antimicrobial activity and had the ability to modulate innate and adaptive immunity. Animals treated with extract for only 7 days before vaccination showed higher levels of antibody production. The extract showed antibacterial and antifungal activities. The extract could stimulate both adaptive and innate immunity. Pre-treatment with the extract increased immune responses in vaccinated animals, indicating the usefulness of the extract before immunization.

Comparative study between: Carboxytherapy, platelet-rich plasma, and tripolar radiofrequency, their efficacy and tolerability in striae distensae.

BACKGROUND: Striae distensae are very common cutaneous disorders that produce great psychological stress for women. OBJECTIVE: measure and compare between efficacy and tolerability of three modalities for treatment of striae distensae. PATIENTS AND METHODS: Forty-five female patients with striae distensae were randomly selected from the outpatient dermatology clinics of Al-Zahra university Hospital within 6 months period. Patients divided into three groups according to the therapeutic modalities were used. Group A: treated with carboxytherapy using carbon dioxide (CO2) injection, Group B: where patients were treated with intradermal injection of autologous platelet-rich plasma (PRP), and Group C: where we used tripolar radiofrequency (RF) for treatment. RESULTS: All treated groups showed overall clinical improvement as regards the width, texture, and overall improvement after treatment (P > .05), with no statistically significant differences between the three groups. Patient's satisfaction was statistically significantly better in both group C (93.33%) and group A (80%) while group B (53.33%) was less with minimal side effects such as pain and ecchymosis, which were more frequent in group B than the other two groups; but with no statistically significance differences both groups A and C were effective with no significant differences in both types of striae and in any site of the body but group B is significantly more effective on striae rubra on trunk, with better improvement of lesions texture. CONCLUSION: The three modalities of treatments proved to be effective clinically and histopathologically in treating both types of striae, which were well tolerated by the patients with minimal, transient side effects and our study results gave us guidelines for their clinical application.

Coat's like vasculopathy in leber congenital amaurosis secondary to homozygous mutations in CRB1: a case report and discussion of the management options.

BACKGROUND: Mutations in the CRB1 gene are associated with variable phenotypes of severe retinal dystrophies, and retinal dystrophies resulting from CRB1 mutations may be accompanied by specific fundus features such as coat's like vasculopathy in retinitis pigmentosa patients. This is the first report of the occurrence of coat's like vasculopathy in a patient diagnosed with Leber congenital amaurosis caused by a CRB1 mutation. CASE PRESENTATION: An 18-year old Syrian female patient presented with bilateral gradual loss of vision since early childhood, with recent deterioration in her left eye. She appeared to have an asymmetric bilateral coat's like vasculopathy which was more severe in the left eye. The diagnosis of Leber congenital amaurosis was suggested, and a genetic CRB1 sequencing for the patient and her two younger siblings, who also had severe vision loss, was done, upon which the diagnosis of Leber congenital amaurosis associated with exudative retinal detachment due to coat's like vasculopathy was made. Treatment with panretinal photocoagulation was attempted in the worse left eye, but with no improvement. As the disease suddenly progressed in both eyes, pars plana vitrectomy with endolaser and silicone oil tamponade was performed in the better right eye which led to anatomical stabilization of the case without improvement in the visual acuity. CONCLUSION: Leber congenital amaurosis is reported to be associated with multiple systemic and ocular findings, none of which is coat's like vasculopathy. CRB1 gene mutations are associated with remarkable retinal findings in patients with retinitis pigmentosa and other fundus dystrophies. In this unique case we are reporting the incidence of coat's like vasculopathy in a patient diagnosed with Leber congenital amaurosis caused by CRB1 gene mutation, and its management. CRB1 mutant patients should be followed up closely as sudden progression can have permanent poor outcomes and as early management is vital in such cases.

Development of species-specific primers for identification of Biomphalaria arabica, the intermediate host of Schistosoma mansoni in Saudi Arabia.

Schistosoma mansoni is mediated through the intermediate host Biomphalaria arabica which lives in Saudi Arabia. Molecular characterization and identification of this intermediate host are important for epidemiological studies of schistosomiasis. The present work aimed to determine the molecular variations among the populations of B. arabica found in Southern part of Saudi Arabia, and to develop species-specific primers for identification of these snails as a first step in the development of multiplex PCR for simultaneously identifying the snails and diagnosing its infections in a single step. Five populations of Saudi B. arabica snails were collected from freshwater bodies. Three populations were collected from Asser and two populations were collected from AL-Baha. Genomic DNA was extracted from snails and was amplified using five different RAPD-PCR primers. The banding patterns of amplified materials by primers P1 and P5 were identical in all populations. However, the rest primers displayed intra-specific differences among populations with variable degrees. Largest sizes of RAPD-PCR products were cloned into TA cloning vector as a preparatory step for DNA sequence analysis. After sequencing, similarity searches of obtained DNA sequences revealed that there are no similar sequences submitted to genebank data bases and its associated banks. The results obtained will be helpful in the development of simultaneous identification of B. arabica snails and diagnosis of S. mansoni infection within it in a single step by an implementation of multiplex PCR.

Developing species-specific primers to identify Bulinus truncatus and Bulinus beccari, the intermediate hosts of Schistosoma haematobium in Saudi Arabia.

This work aimed to determine the inter- and intra-specific variations in populations of Bulinus truncatus and Bulinus beccari, the intermediate hosts of Schistosoma haematobium in Saudi Arabia, and to develop species-specific primers to identify these snails as a first step in the development of multiplex PCR for simultaneously identifying the snails and diagnosing its infections in a single step. Two populations of B. truncatus were collected from Asser and Bisha (A and B), and two B. beccari populations were collected from Mahial Asser and Merba (C and D). The snails' genomic DNA was extracted and amplified using 5 different primers. The primers displayed variable intra- and inter-specific differences across the populations. The largest RAPD-PCR fragments were cloned into a vector as a preparatory step for sequencing. Similarity searches for the sequenced cloned inserts revealed no similar sequences in the GenBank database or its associated databases. Specific primers used to target the B. truncatus and B. beccari genomes were designed using the Gene Runner program and based on the DNA sequences obtained from RAPD fragment sequence analyses. Using these primers for specific PCRs resulted in expected single-band PCR products of 536 bp for B. beccari and 478 bp for B. truncatus. These results will be helpful for simultaneously identifying B. truncatus and B. beccari snails and diagnosing S. haematobium infections within the snails using single step multiplex PCR.

Nutrition, physical activity, and gender risks for adolescent obesity in Southwestern Saudi Arabia.

BACKGROUND/AIM: The aim of the study was to investigate gender differences in obesity and related behavior among adolescent school boys and girls in southwestern Saudi Arabia. PATIENTS AND METHODS: A cross-sectional study on a stratified sample of 1,249 adolescent boys and 620 adolescent girls, was conducted in southwestern Saudi Arabia. They were interviewed and examined for weight and height using standardized techniques. RESULTS: The prevalence of obesity and overweight in the present study amounted to 23.2% among boys and 29.4% among girls. The following significant risk factors were identified; being a female [adjusted odds ratio (aOR) =1.372, 95% confidence interval (CI) =1.099-1.753] and lack of class physical exercise (aOR =1.452, 95% CI =1.149-2.117). CONCLUSION: Obesity among adolescents is a public health problem in Southwestern Saudi Arabia. The problem is more prevalent among girls. Thus, there is a need for a national programme in the country to prevent and control obesity among adolescents.

Fingerprint of Biomphalaria arabica, the intermediate host of Schistosoma mansoni in Saudi Arabia, using RAPD-PCR.

In the time schistosomisis control programs are implemented in many countries, schistosomiasis continues to spread throughout the world. Among these control strategies is the vector control. Within this context, analysis of the genetic variability of the intermediate host snails is important because it allows identification of specific sequences of the genome of this mollusk related to determine their fingerprint. We investigated Biomphalaria arabica, which is found in Saudi Arabia, the intermediate host of Schistosoma mansoni infection. Genetic fingerprint was studied by RAPD-PCR using our own different random primers as well as published primers. The electrophoretic patterns resulting from amplification showed specific polymorphic markers of B. arabica. This information will be helpful in the identification of the snails and demonstrating that RAPD-PCR is an appropriate and efficient methodological approach for establishment of genetic barcode development.

Susceptibility of Biomphalaria spp. to infection with Schistosoma mansoni in sympatric and allopatric combinations with observations on the genetic variability between snails.

This investigation was carried out to study the susceptibility of Saudi Biomphalaria arabica to Egyptian Schistosoma mansoni in comparison with the susceptibility of Egyptian Biomphalaria alexandrina to the same parasite. This was in order to know the possibility that the parasite might be able to spread into Saudi Arabia and to determine the genetic variability between Egyptian B. alexandrina and Saudi Biomphalaria arabica snails. Lab bred Egyptian B. alexandrina and Saudi B. arabica snails were exposed individually to 10 freshly hatched Egyptian S. mansoni miracidia/snail. The mortality rate, infection rate, prepatent period, duration of cercarial shedding and cercariae production per snail were recorded in both the sympatric couple (Egyptian B. alexandrina and Egyptian S. mansoni) and in the allopatric combination (Saudi B. arabica and Egyptian S. mansoni). The results revealed that, the survival rate of snails exposed to Egyptian S. mansoni miracidia at 34th day post-exposure (at first cercarial shedding) was higher in B. arabica than in B. alexandrina. After shedding, the mortality rate was higher in the B. arabica, compared to B. alexandrina. The infection rate was higher in B. arabica than B. alexandrina; the mean of prepatent period was shorter in the B. arabica than in the B. alexandrina. However, the duration of cercarial shedding was longer in the Egyptian snails and the cercarial production per snail was higher in B. alexandrina snails than in B. arabica. To study the genetic variability between B. alexandrina and B. arabica, RAPD-PCR on the genomic DNA of snails was done. RAPD-PCR revealed significant variation between the two snail species. In conclusion, the results suggest that B. arabica can play a role in the transmission of Egyptian S. mansoni in Saudi Arabia and therefore this parasite might be able to spread into the Kingdom. In addition, the RAPD-PCR results demonstrated genetic variability between the two species which may be related to the differences in susceptibility of both Saudi and Egyptian Biomphalaria snails to Egyptian S. mansoni infection.

Antischistosomal activity of ginger (Zingiber officinale) against Schistosoma mansoni harbored in C57 mice.

The repeated chemotherapy of schistosomiasis has resulted in the emergence of drug-resistant schistosome strains. The development of such resistance has drawn the attention of many authors to alternative drugs. Many medicinal plants were studied to investigate their antischistosomal potency. The present work aimed to evaluate antischistosomal activity of crude aqueous extract of ginger against Schistosoma mansoni. Sixteen mice of C57 strain were exposed to 100 ± 10 cercariae per mouse by the tail immersion method; the mice were divided into two groups: untreated group and ginger-treated one. All mice were sacrificed at the end of 10th week post-infection. Worm recovery and egg counting in the hepatic tissues and faeces were determined. Surface topography of the recovered worms was studied by scanning electron microscopy. Histopathological examination of liver and intestine was done using routine histological procedures. The worm burden and the egg density in liver and faeces of mice treated with ginger were fewer than in non-treated ones. Scanning electron microscopical examination revealed that male worms recovered from mice treated with ginger lost their normal surface architecture, since its surface showed partial loss of tubercles' spines, extensive erosion in inter-tubercle tegumental regions and numerous small blebs around tubercles. Histopathological data indicated a reduction in the number and size of granulomatous inflammatory infiltrations in the liver and intestine of treated mice compared to non-treated mice. The results of the present work suggested that ginger has antischistosomal activities and provided a basis for subsequent experimental and clinical trials.

Cardiovascular risk factors among adolescent secondary school boys in Ahad Rufeida, southwestern Saudi Arabia.

A cross-sectional stratified sample of 1249 adolescent secondary school boys was studied. More than 25% of boys did not practice any physical exercise. More than half of the parents (54.5%) were consanguineous. High prevalence of parental history of hypertension, diabetes and high blood lipids was found. Smoking amounted to 11.8%. The prevalence of obesity was 23.3%. The study showed that 6.8% had a high systolic blood pressure and 13.0% (162) had high diastolic blood pressure. There is a need for a national programme to prevent and control cardiovascular risk factors among adolescents.

Green tea (Camellia sinesis) ameliorates female Schistosoma mansoni-induced changes in the liver of Balb/C mice.

This study was designed to assess the effect of green tea, an aqueous extract of Camellia sinensis, on the oxidative stress, antioxidant defense system and liver pathology of Schistosoma mansoni-infected mice. Green tea at concentration of 3% (w/v) was given orally to treated mice as sole source of drinking water from the end of the 4th week to the end of 10th week post-infection; untreated mice were allowed to drink normal water. The data of the studied S. mansoni-infected mice exhibited a suppression of hepatic total antioxidant capacity, superoxide dismutase (SOD), catalase (CAT) activity and glutathione content. The liver lipid peroxidation was deleteriously elevated in S. mansoni-infected mice. The hepatic total protein content, AST and ALT activities were profoundly decreased in the S. mansoni-infected mice. Most hepatocytes were damaged and showed abnormal microscopic appearance with aggressive necrosis. Both total protein and glycogen levels have been greatly reduced as indicated by histochemical examination. The treatment of S. mansoni-infected mice with green tea succeeded to suppress oxidative stress by decreasing the lipid peroxides but failed to significantly enhance the antioxidant defense system and deteriorated changes owing to liver damage and necrosis. In consistence with biochemical data, histopathological and histochemical data indicated that treatment of S. mansoni-infected mice with green tea could ameliorate hepatocytes thus reduce cellular necrosis and partially restore both total protein and glycogen levels. Thus, the study concluded that the green tea suppresses the oxidative stress through its constituent with free radicals scavenging properties rather than through the endogenous antioxidant defense system.

Effects of Schistosoma mansoni experimental infection on some inorganic elements in the snail host Biomphalaria alexandrina.

The alteration in the concentrations of metallic ion Pb, Zn, K, Na, Co, Fe, and Cu in the soft parts of the Biomphalaria alexandrina snails shedding Schistosoma mansoni cercariae was detected by flame atomic absorption spectrometry. Six elements Pb, Zn, K, Na, Co, and Cu were found to be present at significantly higher concentrations in cercariae-shedding snails compared with uninfected snails. The concentration of Fe ion showed non-significant decrease in the tissues of cercariae-shedding snails. Variation in the present results compared with related previous studies lead to the suggestion that the effect of trematode parasitism on fresh-water snails should not be considered universal and might be varies according to the trematode-snail combination, the organs or the tissues analyzed and the analytical method used.

Isoenzyme electrophetic characterization of Leishmania major, the causative agent of zoonotic cutaneous Leishmaniasis in North and West Saudi Arabia.

Several expeditions were carried out to four localities (Al-Madinah Almona-warah, Tabouk region, Al-Jouf and Northern Frontiers regions) in Northern and Western Saudi Arabia for sampling zoonotic cutaneous leishmaniasis (ZCL) cases from patients and rodents. Biopsy samples were collected from 51 patients complaining of skin lesions, most of which (40 or 78.4%) proved to be ZCL. Amastigotes were detected in 33 patients (64.7%), but only 30 (58.9%) gave successful growth of promastigotes in the culture media. The positive cases were Saudis 14(35%) and non-Saudis 26 (65%). Five species of rodents were caught, Meriories libycus, Psammomys obesus, Rattus rattus, jaculus and Hystrix indica. The first species was the most dominant (90%) in which Leishmania parasites were detected. The Leishmania isolates from man and rodents were identified by isoenzyme electrophoresis and proved to be Zymodeme LON-4.

Susceptibility of Saudi Bulinus truncatus to infection with Egyptian Schistosoma haematobium with observations on protein electrophoretic pattern of the snails.

A laboratory-based susceptibility study was carried out on snails Bulinus truncatus collected from highland Abha, Asser, Saudi Arabia to Egyptian Schistosoma haematobium to investigate the potential role of Saudi B. truncatus in the transmission of Egyptian S. haematobium and to know the possibility that the parasite might be able to spread into Saudi Arabia. The results revealed that, compared to Egyptian snails, survival of snails at day 25 post-exposure was significantly higher in Saudi B. truncatus ones. The infection rate was higher in Saudi snails as compared to Egyptian ones. The incubation period was shorter in Saudi snails but the duration of cercarial shedding was longer in the Egyptian than in the Saudi snails. The production of S. haematobium cercariae per snail was higher in Egyptian snails than in Saudi ones. These results suggest that Saudi B. truncatus can play a role in the transmission of Egyptian S. haematobium in Saudi Arabia and therefore this parasite might be able to spread into the Kingdom. In addition, electrophoretic analysis of tissue soluble proteins was done to determine the effects of the parasite on both the Egyptian and Saudi snails. The electrophoretic analysis revealed the occasional presence or absence of certain bands in infected snails in comparison with non-infected one.

Susceptibility of two strains of mice to the infection with Schistosoma mansoni: parasitological and biochemical studies.

In this article, two strains of mice BALB/C and C57 were infected with Egyptian strain of Schistosoma mansoni. BALB/C mice appeared to harbor fewer parasites than did C57 mice. The hepatic and intestinal tissues of C57 mice were loaded with more eggs than that of BALB/C mice. Regardless the strain of mice, the number of eggs per gram of liver tissues was higher than in the intestinal tissues. Some biochemical parameters were measured in the liver of infected and non-infected mice; a significant decrease in the activities of alkaline phosphatase, catalase, glutathione-s-transferase, glutathione, and total lipids of infected mice compared to their matched control were observed. However, there was a significant increase in malondialdehyde level of infected mice compared to their matched group. Detailed discussion on the parasitological and biochemical differences between the two strains was presented.