Iranian Biomedical Journal
Year:2012 | Volume:16 | Issue:1|Papers Count:8

Background: Alzheimer's disease (AD) is characterized by progressive neuronal loss in hippocamp. Epidermal neural crest stem cells (EPI-NCSC) can differentiate into neurons, astrocytes and oligodendrocytes. The purpose of this study was to evaluate the effects of transplanting EPI-NCSC into AD rat model.Methods: Two weeks after induction of AD by injection of Amyloid-b 1-40 into CA1 area of rat hippocamp, Y-maze and single-trial passive avoidance tests were used to show deficit of learning and memory abilities. EPI-NCSC were obtained from the vibrissa hair follicle of rat, cultured and labeled with bromodeoxyuridine. When Alzheimer was proved by behavioral tests, EPI-NCSC was transplanted into CA3 area of hippocamp in AD rat model. The staining of EPINCSC markers (nestin and SOX10) was donein vitro. Double-labeling immunofluorescence was performed to study survival and differentiation of the grafted cells.Results: We showed that transplanted EPI-NCSC survive and produce many neurons and a few glial cells, presenting glial fibrillary acidic protein. Total number of granule cells in hippocamp was estimated to be more in the AD rat model with transplanted cells as compared to AD control group. We observed that rats with hippocampal damage made more errors than control rats on the Y-maze, when reward locations were reversed.Conclusion: Transplanted cells were migrated to all areas of hippocamp and the total number of granule cell in treatment group was equal compared to control group. Transplantation of EPI-NCSC into hippocamp might differentiate into cholinergic neurons and could cure impairment of memory in AD rat model.

Background: The secondary genetic changes other than the promyelocytic leukemia-retinoic acid receptor (PMLRARA) fusion gene may contribute to the acute promyelocytic leukemogenesis. Chromosomal alterations and mutation of FLT3 (FMS-like tyrosine kinase 3) tyrosine kinase receptor are the frequent genetic alterations in acute myeloid leukemia. However, the prognostic significance of FLT3 mutations in acute promyelocytic leukemia (APL) is not firmly established.Methods: In this study, the chromosomal abnormalities were analyzed by bone marrow cytogenetic in 45 APL patients and FLT3 internal tandem duplications (ITD) screening by fragment length analysis and FLT3 D835 mutation by melting curve analysis were screened in 23 APL samples.Results: Cytogenetic study showed 14.3% trisomy 8 and 17.1% chromosomal abnormalities other than t (15; 17). About 13% of the patients had FLT3 ITD, and 26% had D835 point mutation. FLT3 ITD mutation was associated with higher white blood cell count at presentation and poor prognosis.Conclusion: The PML-RARA translocation alone may not be sufficient to induce leukemia. Therefore, we assume that FLT3 mutations and the other genetic and chromosomal alterations may cooperate with PML-RARA in the development of APL disease.

Background: Bone tissue engineering requires materials that are biocompatible, mechanically suited for bone function, integrated with the host skeleton, and support osteoinduction of the implanted cells for new bone formation. The aim of this study was to compare the osteogenic potential of xenograft withhydroxyapatite/b-tricalcium phosphate (HA/b -TCP) scaffold.Methods: New Zealand rabbits (n=9) were divided into 3 groups.Osteoblast cells were originally isolated from rabbit iliac crest and cultured in DMEM/F12. After creating a critical-sized defect (2 × 3 cm) in rabbit tibia bone, the defect was filled with an implant of HA/TCP with osteoblasts and xenograft in the hole of left (as control) and right tibia, respectively. The new bone formation and the development of bone union within the defect were evaluated by x-ray images and eosine and hematoxylin staining at 4, 8, and 12 weeks post-operation.Results: The bone partially formed in both groups was filled with osteoblast cultured on porous implants at 4 weeks. Over time, progressive bone regeneration was observed inside the pores. Moreover, a progressive vascular ingrowth and progressive integration with the host bone were obvious in xenograft when comparedto HA/b -TCP. A good integration between the xenograft implants and the bone was observed radiographically and confirmed by histological section.Conclusion: The result showed that the bone defect can be repaired using both synthetic and xenograft implants. However, the xenograft showed a better osteointegration as comparedto HA/b -TCP scaffold.

Background: Hippocampal damages, which are accompanied by inflammation, are among the main causes of epilepsy acquisition. We previously reported that chronic intracerebroventricular (i.c.v.) injection of lipopolysaccharide (LPS) modulates epileptogenesis in rats. There is a network of gap junction channels in the hippocampus that contribute to epileptogenesis. Gap junction channels are formed by oligomeric protein subunits called connexins (Cx). Astrocytic Cx43 and neuronal Cx36 are expressed in the hippocampus. In order to find out the possible role of gap junctions in seizure-modulating effect of LPS and neuroinflammation, we studied the effect of central administration of LPS on expression of Cx36 and Cx43 in rat hippocampus.Methods: LPS, 2.5 mg/rat/day, was injected i.c.v. to male Wistar rats for 14 days. M RNA and protein abundance of Cx36, Cx43 and IL1-b were measured in rat hippocampus by real time-PCR, Western blot and ELISA techniques, at the beginning, in the middle, and at the end of the treatment period.Results: IL1-b protein level was significantly increased 6 h after first injection of LPS. Cx36 and Cx43 mRNA expression did not alter during chronic administration of LPS.A selective decrease in Cx43 protein expression was observed after 7 injections of LPS.Conclusion: It is suggested that Cx43 containing gap junctions in the hippocampus is down-regulated in response to chronic injection of LPS. This event can inhibit propagation of toxic and noxious molecules to neighboring cells and modulate hippocampal excitability and epileptogenesis.

Background: To achieve multiple oocytes for in vitro fertilization, ovulation induction is induced by gonadotropins; however, it has several effects on oocytes and embryo quality and endometrium receptivity. The aim of this study was to assess ultrastructural changes of corpus luteum after ovarian induction using human menopausal gonadotropin (HMG) and human chorionic gonadotropin (HCG) during luteal phase at implantation period.Methods: Female NMRI mice (6-8 weeks) were divided into control and stimulated groups. In the control group, the mice were rendered pseudopregnant and in the ovarian induction group, the mice were rendered pseudopregnant after the ovarian induction. The samples were obtained from the ovary in each group at the same time during luteal phase at implantation period. Ultrastructural changes were assessed using electron microscopy study.Results: Our results displayed some identifiable changes in ultrastructure of corpus luteum in ovarian induction group. These changes included enhancement of the apoptosis and intercellular space, whereas the angiogenesis was decreased. The findings indicated a decline in organelle density in the cytoplasm of ovarian induction, such as mitochondria, endoplasmic reticulum and polyribosome. Furthermore, chromatin condensation of nuclei was observed in some cells.Conclusion: The ovarian induction using HMG and HCG resulted in some ultrastructural changes on the corpus luteum at implantation period, which could affect on the pregnancy rate.

Endometriosis is a common chronic inflammation causing major problems including infertility. The role of omega-3 and omega-6 fatty acids as their potential anti-inflammatory effects in endometriosis needs to be further explored. The objective of this study was to compare serum phospholipid fatty acid profile in endometriosis patients with controls, and to explore the correlation of this profile with the severity of the disease.Methods: Sixty four endometriosis patients and 74 control women, in reproductive age, participated in this study. Among the endometriosis patients, 19 cases were in stage I, 27 cases in stage II, 8 cases in stage III, and 10 cases in stage IV.Each patient underwent laparoscopy. Before surgery, 5 ml of blood was obtained. After extraction of the total lipids, serum total phospholipid fraction was isolated by thin layer chromatography. Fatty acid composition of the phospholipid fraction was determined by gas chromatography and the resulted profile was compared in endometriosis patients and controls. The profile was also compared in the endometriosis group based on the severity of disease.Results: Stearic acid was significantly lower in the endometriosis group as compared to controls (P=0.030). No other fatty acid compositions were significantly different between patients and controls.Serum ratio of eicosapentaenoic acid (EPA) to arachidonic acid (AA) was in reasonable correlation with the severity of endometriosis (r=0.34, P=0.006).Conclusion: According to these findings, levels of fatty acids in serum total phospholipids seem not to be a marker for endometriosis, but the EPA to AA ratio was a relevant factor indicating severity of illness.

Background: Antioxidants such as a-tocopherol (vitamin E) and b-carotene (vitamin A) play an important role in protective effect of repeated brief periods of ischemia, namely ischemic preconditioning (IPC). Values of these antioxidants were investigated and compared after induction of ischemia reperfusion (IR) and kidney IPC in both male and female rats.Methods: Forty eight Wistar rats were divided randomly into six groups of 8: groups A and B (male and female controls, respectively), group C (male IR or IR cases), group D (female IR cases) and groups E and F (male and female IPC cases, respectively). In groups C and D, ischemia was induced by clamping of left renal arteries for 45 min. In groups E and F, rats underwent four cycles of 4 min of arterial clamping and 11 min of de-clamping before final 45 min ischemia induction. Afterward, serum was collected to assess the blood urea nitrogen, creatinine and vitamins E and A values. Renal tissues were obtained for histological assessments.Results: a-tocopherol levels in male and female rats showed a significant increase in IPC compared with IR group (P<0.01) and also in female IPC compared with male IPC group. b-carotene levels had no significant variations.Histological evaluation showed that IR-induced renal injuries were less in female rats. Also, protective effects of IPC were more in female rats (P<0.01). Conclusions: Renal IPC reduced damages in both male and female rats, but tissue injuries in females were decreased much more along with the increase of endogenous vitamin E.

Background: To develop a new green approach for biosynthesis of silver nanoparticles, myconanotechnology has been represented as a novel field of study in nanotechnology. In this study, we have reported the extracellular synthesis of highly stable silver nanoparticles using three species of dermatophytes: Trichophyton rubrum, Trichophyton mentagrophytesand Microsporum canis.Methods: Clinical strains of these species were grown in a liquid medium containing mineral salt and incubated at 25°C for 5-7 days. The cell-free filtrate of each culture was obtained and subjected to synthesize silver nanoparticles in the presence of 1 mM AgNO3.Results: The reduction of Ag+ ions in metal nanoparticles was investigated virtually by tracing the solution color which was switched into reddish-light brown after 72 h. ForT. mentagrophytes, a UV-visible spectra demonstrating a strong, quite narrow peak located between 422 and 425 nm was obtained. ForM. canis, a fairly wide peak centering at 441 nm and for T. rubrum, a weak spectrum to decipher were observed. According to transmission electron microscopy (TEM) results, fairly uniform, spherical, and small in size with almost less than 50 nm particles were forms in case of T.mentagrophytes. For the other two species, TEM images showed existence of small spherical nanosilvers but not as small as nanoparticles synthesized byT. mentagrophytes.Conclusion: We observed that species belong to a single genus of the fungi have variable ability to synthesize silver nanoparticles extracellulary with different efficiency.Furthermore, the extracellular synthesis may make the process simpler and easier for following processes.