جلال بابایی

Toxoplasma gondii is an obligate intracellular parasite. T. gondii leads to increased production of dopamine in the host's brain. It is possible that dopamine plays a role in the proliferation of T. gondii. In this study, the effect of dopamine on the proliferation of Toxoplasma tachyzoites in HFF-1 cells was investigated.

HFF-1 cells were cultured and treated with 500 nM dopamine. 4 × 105 tachyzoites were added to the cell wells. To investigate the role of receptors, first the confluensed cells were treated with dopamine. Dopamine D1 and D2 receptor antagonists (SCH-23390 and sulpiride, respectively), alone and in combination, were added to the culture medium at a concentration of 10 nM. The treated cells were infected with Tachyzoite. The amounts of tachyzoites were evaluated by microscopic counting and by RT-qPCR method.

Dopamine significantly (p < 0.05) increases proliferation of tachyzoites in HFF-1 cells. SCH-23390 significantly neutralized the effect of dopamine in treated cells (p < 0.05), while sulpiride could not avert the effect of dopamine. Moreover, combination of two antagonists, SCH-23390 and sulpiride, significantly reduced the proliferation of tachyzoites in HFF-1 cells (p < 0.05).

Our study showed that dopamine stimulates proliferation of tachyzoites in HFF-1 cell line. In addition, dopamine exerts its effect on parasite proliferation through D1 receptors. These results can help to design and develop effective drugs against Toxoplasma.

Extraction of Toxoplasma gondii genomic DNA from rat brain is challenging due to low level of contamination and high fat content. Quantitative real-time polymerase chain reaction (RT-qPCR) is associated with false negative results despite detecting small amounts of the gene. By changing method of DNA extraction, we could decrease number of false negative results.

Brains of eleven male Wistar rats infected with Tehran strain of Toxoplasma parasite (with 8 weeks of parasite infection) and three uninfected rats were isolated. The whole brain was used to purify DNA instead of 20 mg brain in the conventional method. Amount of protein kinase was doubled and the incubation period increased to 6 times. Then DNA of the samples was measured by RT-qPCR.

Only three of the eleven infected rats were infection positive by the conventional method, while nine mice were positive by the optimizing method.
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Toxoplasmosis is a globally prevalent parasitic infection caused by Toxoplasma gondii. A flu-like syndrome is seen in the acute phase of infection with no obvious symptoms in the chronic phase. In this study effect of co-trimaxazole on parasite load and inflammation in the brain of infected mice was examined.

Mice were infected by intraperitoneal injection T. gondii cysts. Transcription of REP-529 (as indicator of parasite load) and TNF-α (as indicator of inflammation) were measured in the mice brain by RT-qPCR, at weeks 1-8 after injection of cysts, and after treatment with co-trimoxazole. Co-trimoxazole was administered 10 days before the weeks 4 and 8 of the infection for 10 days.

Severe ascites was observed during 4-14 days after injection of cysts. The REP-529 transcription level indicates that the parasite enters the brain 1 week after cyst injection and proliferated rapidly in the second and third weeks. TNF-α level increased and reached the maximum level in the second week and then decreased in the next weeks. Co-trimoxazole significantly reduced transcription of both REP-529 and TNF-α during 4 and 8 weeks of infection. Co-trimoxazole caused significant (p < 0.01) weight gain in mice at the week 4 of infection compared to the untreated group.

We found chronic administration of co-trimoxazole to mice infected by T. gondii can inhibit parasite proliferation and inflammation in the brain and cure the disease.

Epilepsy is the third most common neurological disorder after stroke and Alzheimer's disease. Genetic factors, infectious diseases, brain trauma / stroke, inflammation and febrile seizure during childhood are among the factors that cause epilepsy. However, the underlying cause of epilepsy is not known in 60% of patients, which is called cryptogenic epilepsy. Toxoplasmosis is an important parasitic infection with a worldwide spread caused by Toxoplasma gondii. Chronic infection does not have symptoms in people with an effective immune system. Nevertheless, recent studies have shown that this infection is probably a risk factor for some of the neurological abnormalities, including epilepsy. The aim of this study was to review published articles to estimate the risk of epilepsy due to Toxoplasmosis.

We directed a systematic literature search on the history of toxoplasmosis and epilepsy from different databases without any date limitation, to identify studies published in Persian or English. Search was conducted in a series of keywords in both Persian and English. The odds ratio was used to calculate the risk factor of Toxoplasma gondii for epilepsy. In all experiments, p < 0.05 was considered statistically significant.

Ten studies were found until 2017. 3925 cases were studied, of which 2023 cases (627 Toxoplasma-positive) were epileptic and 1902 cases were not (572 Toxoplasma-positive). The total odds ratio was 1.16 (1.01-1.32), p = 0.034.

Despite few studies, toxoplasmosis might be considered as a risk factor for acquisition of epilepsy. To further clarify the effect of this parasite on acquisition of epilepsy, more comprehensive studies with enough number of different types of epilepsy and appropriate controls are required.

As developmental psychologist cease to perceive adolescence as a period of turmoil and adopt the Positive Youth Development (PYD) perspective, pschometrically sound measurement tools will be needed to assess adolescent positive attributes. The present research aimed to study psychometrics characteristics of positive youth development questionnaire in students. The present study was descriptive and correlation studie's type. For this purpose, 400 students (200 boys and 200 girls) were selected by multistage cluster sampling method & answered positive youth development Geldhof et al (2014) and Illinois bullying (2001) scales. For data analysis, was used from factor analysis, Cronbach's alpha coefficient and Pearson correlation methods. Factor analysis result showed that this scale was saturated with five factors. In addition, Pearson correlation results indicated that the positive youth development with discipline (r=0.32) academic achievement (r=0.31) and bullying (r=-0.45) significant relationship p≤0.01 there. Also positive youth development questionnaire reliability using Cronbach's alpha for the total scale was 0.81 and for each of the subscales, including competence 0.50, confidence 0.86, character 0.52, caring 0.63 and connection 0.79. Results indicated that positive youth development in the Persian version of the questionnaire can be used as a valid instrument in psychological research.

The aim of this study was to investigate the relationship of positive youth development and life satisfaction with attitude toward substance use in high school students of Qom city.
This study was a descriptive research, which falls within the category of correlational studies. The senior high school students of Qom city constituted the statistical population of this study, among whom the number of 385 students (198 girls and 187 boys) was selected through multistage cluster sampling. The participants completed Geldhof et al.'s Positive Youth Development Scale, Diener et al.'s Satisfaction with Life Scale, and Rezaee et al.'s Attitude toward Substance Use Questionnaire.
Pearson correlation results indicated that the components of positive youth development has a significant negative relationship with attitude toward substance use. In addition, a significant negative relationship was observed between the components of attitude toward substance use and life satisfaction. Stepwise regression analysis revealed that the components of positive youth development (connection, character, and caring) and life satisfaction respectively make the highest contribution to the prediction of attitude toward substance use.
The current research findings emphasized the need for attention to the assets and resources of positive youth development and life satisfaction as the effective factors in reducing addiction and substance use among students.

The aim of this study was to predict bullying on the basis of positive youth development and life satisfaction in adolescents. For this purpose, a sample comprising of 385 students (198 girls, 187 boys) were selected through multistage cluster sampling. They completed Geldhof et al positive youth development questionnaire, Diener et al life satisfaction scale and Illinois bullying scale. Data were analyzed using Pearson correlation and multiple linear regression analysis. Result indicated that relationship between the components of positive youth development and bullying was negatively significant. In addition, relationship between components of positive youth development and life satisfaction was positively significant. Also relationship between bullying and life satisfaction was negatively significant. Linear regression analysis revealed that the components of positive youth development and life satisfaction are able to predict bullying. Result revealed that assets and resources of positive youth development and life satisfaction are essential in effectuating aggression and bullying

The present research aimed to study the psychometric characteristics of a subjective well-being questionnaire among high school students.
This was a descriptive correlational study. A total of 400 high school students (200 boys and 200 girls) in the City of Ghom, Iran were selected by multistage cluster sampling. Data were collected using the Oxford subjective well-being and happiness inventory questionnaire. Factor analysis and Cronbach's alpha coefficient and the Pearson correlation test were used to analyze the data.
Factor analysis showed that the scale was saturated with four factors. In addition, Pearson correlation test indicated that subjective well-being was positively associated (p Based on the findings is concluded that the Persian version of the subjective well-being questionnaire is an acceptable tool to determine the psychometric characteristics of high school students and can be used as a valid instrument in psychological research.

Backgrounds & Dense granule antigen(GRA) of Toxoplasma gondii parasite is important in survival and pathogenicity of Toxoplasmosis. GRA2 is one of the dense granule proteins that can be useful specifically in detection of antibodies against toxoplasm antigens and diagnosis of infection.The aim of this survey was to evaluate recombinant GRA2 protein in diagnosis of toxoplasmosis by ELISA. The recombinant GRA2 protein was produced by culturing of Escherichia coli (BL21(DE3)pLysS) and purified by affinity chromatography. GRA2 was then used as antigen in ELISA Plate for evaluation of serum diagnosis ability which was previously identified as a standard method in both acute and chronic phases. In this study, 35 acute and 40 chronic phase sera were distinctly investigated, using the plates coated by recombinant GRA2 protein. All of 35 acute phase sera (100%) and 31 (77.5%) out of 40 chronic phases reacted with recombinant GRA2 antigen. The results showed that they were all over cut off point or line. The recombinant GRA2 protein may improve diagnosis process with a higher accuracy specificity compared with whole antigen. It may be also considered for standardization improvment in diagnosis techniques for Toxoplasma gondii.