مقالات رزومه دکتر ناهید رئیسی

Light-dark cycles regulate the body’s physiological activity; hence, marked changes in these cycles could lead to conditions with impaired brain functions and disrupted moods (e.g., stress). Therefore, this study compared the impact of stress due to various photoperiodic durations on anxiety-like behavior, learning, memory, locomotor activity and memory consolidation in rats.

Thirty-five male rats were divided into five groups with different light(L)-dark(D) cycles: L20/D4, L16/D8, L12/D12 (control), L8/D16 and L4/D20 groups. After14 days, the elevated plus-maze (EPM) and passive avoidance (PA) tests were performed to assess the anxiety-like behaviors and brain functions.

The percentage of spent time, number of entries to the open arm of the EPM test and the entrance latency to the dark room of the PA test decreased significantly in the L20/D4 and L4/D20 groups; however, the reduction of latency to enter the dark room was particularly significant in the L20/D4 group. In addition, there were significant differences between the initial latency and latency after one day (as learning) in all experimental groups. The total dark stay time increased significantly in different photoperiods.

An abnormal light-dark length could disrupt certain brain functions, such as learning, memory, locomotor activity, memory consolidation and anxiety-like behavioral responses at different levels in a time-independent manner. The light-dark length (both minimum and especially the maximum day length) led to increased learning impairment and memory deficits, as well as worsened anxiety-like behaviors. The memory consolidation was also disrupted with various photoperiods.

Administration of antidepressants and exercise are among the therapeutic approaches to chronic stress. Therefore, this study compared the therapeutic effects of different doses of escitalopram, exercise, and exercise-accompanied escitalopram on synaptic potency and long-term plasticity in the hippocampal CA1 area in rats under chronic restraint stress.

The rats were allocated to different groups. The chronic restraint stress (6 hr/day) continued for 14 days. Injection of escitalopram (10 and 20 mg/kg) and treadmill running (1 hr/day) were performed after the stress induction. The input/output (I/O) functions and LTP induction were evaluated in the hippocampal CA1 area.

The fEPSP slope and amplitude after the LTP induction significantly decreased in the chronically stressed group. However, the serum corticosterone levels had significant enhancement in this group. In addition to serum corticosterone levels, the fEPSP slope and amplitude after the LTP induction were enhanced by exercise, escitalopram 20 mg/kg alone, and exercise-accompanied escitalopram 10 and/or 20 mg/kg in chronically stressed groups.

Overall, chronic stress impaired synaptic potency and long-term plasticity. These impairments were effectively reversed by exercise, escitalopram 20 mg/kg alone, and exercise-accompanied escitalopram 10 and 20 mg/kg. However, escitalopram 10 mg/kg alone could not alleviate the memory deficits in chronically stressed subjects. Therefore, exercise with both doses of escitalopram seems to have had additive effects on chronic stress conditions.

Vitamin D (Vit-D) is a necessary ingredient for human growth and its deficiency may increase the risk of cancer and its recurrence. The main purpose of this research was to assess the levels of Vit-D in children with recurrence of malignancy and compare it with new cases of malignancy and the control group.

The status of 25(OH) Vit-D was determined utilizing the HPLC method in 47 patients with recurrence of malignancy (group A), 50 children with new malignancy (group B) and 49 normal healthy siblings of the two groups as a control (group C).

Vit-D was low (<30 ng/ml) in the 92% of patients with recurrence of malignancy, which was a significant difference compared to groups B (60%) and C (45%). Vit-D insufficiency (10-30 ng/dl) in group A was also higher than the other two groups. The mean levels of Vit-D in patients with recurrence were significantly lower than the new cases and controls. Low Vit-D (<30 ng/ml) in group A in both male and female, and also in all ages (<6 and ≥ 6 years) was higher than groups B and C. Also, low Vit-D in terms of the type of malignancy in group A was higher than group B only in leukemic patients while this was not different for non-leukemic patients in these two groups.

Results of this study showed an increased prevalence of low Vit-D in children with recurrence of malignancies. Therefore, it may increase the risk of recurrence of malignancies in children.

The development of secondary malignancy (SM) is the most worrisome long-term complication of childhood cancer. Acute myeloid leukemia is the most prevalent neoplasm that occurs after treatment with alkylating agents and topoisomerase II inhibitors. Pleuropulmonary blastoma (PPB) is a rare lung neoplasm in children. Type II and type III of this cancer are markedly aggressive and have a recurrent nature. Chemotherapy, radiation therapy, and hematopoietic stem cell transplant (HSCT) are treatment modalities that make these patients prone to secondary malignancy. Here was presented and discussed a case of myeloid leukemia 3.5 years after treatment of Pleuropulmonary blastoma in a 5.5-year-old boy who was a candidate for high dose chemotherapy and autologous stem cells transplant (auto-SCT) because of frequent recurrence and lack of response to chemotherapy and radiation therapy. It seems this is the first reported case of therapy-related myeloid leukemia (t-AML) after PPB in children. Awareness of the creation of this complication following administration of cytotoxic therapies in the treatment of solid tumors will increase physician attention in the selection of treatment modality as well as the counseling of patients at the time of diagnosis.

Bernard-Soulier syndrome (BSS) is a rare, autosomal recessive platelet function disorder which is commonly mistaken for idiopathic thrombocytopenic purpura (ITP).The report includes seven cases of BSS that have been diagnosed and treated as ITP for a long time.

Between 2006 and 2016, data of seven BSS patients who have long been diagnosed and treated as ITP were collected and analyzed.

Two patients were males and 5 were females. The patient's age range was between one day and four years at the onset of symptoms. Easy bruising, nose bleeds and mucocutaneous bleeding   were the most frequent symptoms. Bleeding attacks of the gum, gastrointestinal tract and menorrhagia also occurred and in one case bleeding in the injection site of the first vaccination was reported. In 6 patients, parents were relatives and in three cases, there was a family history of low platelet counts. Variable thrombocytopenia, prolonged bleeding time (BT), and large platelets with increased bone marrow megakaryocyte were seen in all cases. Most patients were treated with steroids, Intravenous immunoglobulin (IVIG), and some with IV anti-D, Azathioprine, Danazol, Rituximab. Splenectomy was performed in one case. In supplementary tests the platelet aggregation to ristocetin was absent and GPIb expression level by flow cytometry method was lower than 10%.

BSS should always be considered in differential diagnosis of ITP especially in persistent and refractory ITP.

Neurocognitive deficits and decrease in intelligence quotient (IQ) is one of the complication of prophylactic central nervous system (CNS) treatment in acute lymphoblastic leukemia (ALL) patients. In this study, we compare the IQ in survivors of ALL that were treated with different prophylactic CNS treatments.

We compared 43 long-term survivors of ALL: 21 survivors with intrathecal methotrexate (IT MTX) as CNS prophylaxis, 22 with IT MTX+1800-2400 rads cranial irradiation and 20 healthy controls. The IQ was measured using the Raven’s test in these patients.

Raven’s test revealed significant differences in IQ between the survivors of ALL that were treated with IT MTX, IT MTX plus cranial irradiation and control group. There was no significant difference in the IQ with respect to sex, age and irradiation dose.

We can that reveal that CNS prophylaxis treatment, especially the combined treatment, is associated with IQ score decline in ALL survivors. Therefore,a baseline and an annual assessment of their educational progress are suggested.