defense mechanisms

Breast cancer, as the most common cancer, is the cause of death of millions of people around the world. Given that psychological status can be effective in responding to treatment by affecting the immune system, the aim of this study was to present a model for predicting the status of the immune system through personality type D mediated by defense mechanisms in patients with breast cancer.

The statistical population of the present study included all women with breast cancer in Tehran and Gilan in 1398, from which 250 were selected by purposive sampling. Data were collected using a Type D personality, Questionnaire Defense Style Questionnaire and Warning Signs of Immunodeficiency. Pearson correlation coefficient and structural equation modeling were used to analyze the data using AMOS and SPSS software version 22.

The results showed that there was a significant and direct correlation between the status of the immune system and the neurotic defense mechanism, undeveloped defense mechanism and personality type D and a significant and inverse correlation between the status of the immune system and the developed defense mechanism. Also, defense mechanisms played a mediating role in the relationship between personality type D and immune system status in breast cancer patients.

Accordingly, in patients with breast cancer, the status of the immune system can be predicted through defense mechanisms and personality type D. Therefore, therapists and health professionals can help these people overcome their disease by designing interventions based on modifying defense mechanisms and personality type D. Thus, the more an individual uses the immature defense mechanism, the weaker the immune system is, and the use of the developed defense mechanism is associated with a stronger immune system. Based on the findings, it can be said that designing psychological interventions based on modifying defense mechanisms and changing personality type D, can help a patient with breast cancer to manage and treat the disease.

Today, the ornamental plants survival in the green space due to climate change and a sudden increase in temperature in cold seasons has been compromised. In order to evaluate the effect of irrigations and temperatures on viola plants, a factorial experiment was conducted based on completely randomized design with four replications in faculty of agriculture, Ferdowsi University of Mashhad. Experimental factors include levels of irrigation water (80%, 60 % and 40 % FC) and levels of temperatures (20, 0, -3, -6, -9, -12, -15, -18, -21 and -24 °C). After irrigation treatments, some traits including proline, carbohydrate, chlorophyll (a, b and total), carotenoid and relative water content and after temperature treatments activity of superoxide dismutase, ascorbate peroxidase and total phenol were determined. The results showed that carbohydrate and proline significantly increased and chlorophyll and relative water content decreased at 40% irrigation treatment. Interaction effects of irrigation and temperature treatments significantly affected the activity of two enzymes. The maximum activity of superoxide dismutase and ascorbate peroxidase in 40% FC level of irrigation water at 0 °C were seen, but with decreasing temperature, the activity of these enzymes were reduced. In three irrigation levels, the amounts of total phenols were increased from 20 to 0 °C and reached to minimum at -24 °C. After the recovery period, plants treated with 60% FC at 0 °C showed the highest vegetative traits (height, number of nodes, leaves, offshoot and flower diameter).

Medicinal plants, as one of the important sources for the treatment of diseases, have been used from thousands years ago. These plants produce a major and diverse group of secondary metabolites. Secondary metabolites are the compounds derived from the primary metabolites (metabolites associated with the plant nutrition and survival) essential to sustain plant life. Manipulation of the cell culture media by the abiotic elicitors is one of the important strategies for the induction and production of valuable metabolites, because the potential of natural producing of these compounds is very limited. Elicitors induce secondary metabolites by the activation of defense mechanisms and genes through the increasing ionic flow across the plasma membrane, reactive oxygen production, structural changes in the cell wall as well as phytoalexin production. In this paper, various aspects of increasing secondary metabolites production have been reviewed in the plant cell culture systems using abiotic elicitors.

Regarding negative effects of Cd on wheat growth, it seems that evaluation of wheat cultivars behaviors in response to Cd existence is necessary. In this regard, six different cultivars of wheat were selected and cultivated by aeroponic system. Then they were treated by 200 mM cadmium chloride for 14 days since they have reached 3 or 4 leaves stage. Finally, plants were sampled and morphological characteristics, parameters subjected to defense mechanisms as well as amount of accumulated Cd in tissues were evaluated. The results showed that cadmium accumulation in tissues significantly decreased root length and dry matter of root, shoot and whole plant. Cd accumulation also increased hydrogen peroxide amount in leaf cells of Kohdasht and Pishtase cultivars. However, lipid peroxidation was noticed in Izengeran cultivar as well as two previously mentioned cultivars. The reduced activities of glutathione
S-transferase, catalase and ascorbate peroxidase enzymes are probably the main reasons of the lipid peroxidation increase in Kohdasht cultivar. However, there was no damage on membranes of Izengran and Pishtase cultivars, which indicates the balance between production and scavenging of damaging factors of these cultivars. Generally, it can be stated that available Cd in medium was adsorbed and accumulated in wheat leaves resulting in reduction in dry matter of different parts and whole seedling of wheat which is due to susebtability of different cultivars to Cd. However, there were no oxidative stresses in leaves of Gaskogen, Agosta and MV17 cultivars due to their better defense mechanisms.

Sunflower seeds were planted under field conditions in order to investigate the behavioral pattern of photooxidation tolerance in plants in response to leaf aging. During pollination stage, the leaves were theoretically divided into three sections including young, middle aged and senescent leaves, so that the cell defense potential would change with leaf aging, and then modeling of different intensities of light and its effects on light oxidation of biological materials in the leaves of different ages was investigated. The results from the first series of experiments showed that despite of no change of chlorophyll content in leaves due to leaf aging, total protein content and membrane stability index were declined. Furthermore, lipid peroxidation and hydrogen peroxide were increased in respond to leaf aging. Meanwhile, the activity of hydrogen peroxide scavenging enzymes and glutathione S-transferase in senescent leaves were higher than that of young leaves. Overall, the results showed that with any increase in leaf age, defense potential of cells slowed down and the production of oxidants exceeded the scavenging potential of the cells. The results of modeling of different intensities of light revealed that in senescent leaves under high light intensities, hydrogen peroxide reached to its highest levels. However, under those light condition, hydrogen peroxide scavenging enzymes and glutathione S-transferse activities were recorded at amounts lower than that of low light intensities. The outcome of the above mentioned factors lead to oxidation of chlorophyll and subsequently its content reduction under highlight intensities in aged leaves. In total, under high light intensities, the damage of oxidation stress on aged leaves was more intensified compared to young leaves mainly due to diminished defense potential of stress faced cells.