Computed Tomographic measurement of distal femor rotation in Iranian population

Background: Proper rotation of components in total knee arthroplasty (TKA) will largely affect the postoperative outcome. Ethnical variation may affect rotational profile. We aimed to evaluate distal femur rotation in Iranian population using transepicondylar axes. Methods: From a total of 450 knee CT scans and via consecutive sampling, 150 qualified subjects with normal lower extremities alignment were selected comprising 96 (64) males and 54 (36) females aging 17-80 years. The posterior condylar angle and condylar twist angles were defined as angles between either surgical epicondylar axis (line connecting lateral epicondylar prominence and the medial sulcus) or clinical epicondylar axis (line connecting most prominent points of both epicondyle) and posterior conylar line. Data were compared among genders. Results: Average age of our samples was 43 years (ranging 11-80). Mean (±sd) values for posterior condylar angle and condylar twist angles were 2.35° (±1.34) and 5.77° (±1.70), respectively. The former variable was not discernible in twenty of our subjects because of obscure medial sulcus. Our findings were totally appeared similar to studies from other ethnicities and the observed minor differences may have originated from amount of osteoarthritis and malalignment. Conclusion: Overall, Iranian distal femur rotational profile was similar to other reports. Some minor observed differences may be partially due to samples' age and different amount of knee osteoarthritis. It is proposed to rely on several methods for determining rotational profile while performing TKA. Moreover, preoperative computed tomography should be fully scrutinized especially in severely osteoarthitic knees

Investigation of potential cognition factors correlated to fire evacuation

The design of a navigation system to support indoor fire evacuation depends not only on speed but also a relatively thorough consideration of the cognition factors. This study has investigated potential cognition factors which can affect the human behaviours and decision making during fire evacuation by taking a survey among indoor occupants in age of 20s under designed virtual scenarios. It mainly focuses on two aspects of Fire Responses Performances (FRP), i.e. indoor familiarity (spatial cognition) and psychological stress (situ-ated cognition). The collected results have shown that these cognition factors can be affected by gender and user height and they are correlated with each other in certain ways. It has also investigated users‟ attitudes to the navigation services under risky and non-risky conditions. The collected answers are also found to be correlated with the selected FRP factors. These findings may help to further design of personalized indoor navigation support for fire evacuation

Histone H1 Depletion Impairs Embryonic Stem Cell Differentiation

Pluripotent embryonic stem cells (ESCs) are known to possess a relatively open chromatin structure; yet, despite efforts to characterize the chromatin signatures of ESCs, the role of chromatin compaction in stem cell fate and function remains elusive. Linker histone H1 is important for higher-order chromatin folding and is essential for mammalian embryogenesis. To investigate the role of H1 and chromatin compaction in stem cell pluripotency and differentiation, we examine the differentiation of embryonic stem cells that are depleted of multiple H1 subtypes. H1c/H1d/H1e triple null ESCs are more resistant to spontaneous differentiation in adherent monolayer culture upon removal of leukemia inhibitory factor. Similarly, the majority of the triple-H1 null embryoid bodies (EBs) lack morphological structures representing the three germ layers and retain gene expression signatures characteristic of undifferentiated ESCs. Furthermore, upon neural differentiation of EBs, triple-H1 null cell cultures are deficient in neurite outgrowth and lack efficient activation of neural markers. Finally, we discover that triple-H1 null embryos and EBs fail to fully repress the expression of the pluripotency genes in comparison with wild-type controls and that H1 depletion impairs DNA methylation and changes of histone marks at promoter regions necessary for efficiently silencing pluripotency gene Oct4 during stem cell differentiation and embryogenesis. In summary, we demonstrate that H1 plays a critical role in pluripotent stem cell differentiation, and our results suggest that H1 and chromatin compaction may mediate pluripotent stem cell differentiation through epigenetic repression of the pluripotency genes

Distal femur morphology of Iranian population and correlation with current prostheses

Background: Maintaining proper size and rotation of components of total knee arthroplasty is mandatory for optimal longevity. Ethnical differences may affect the fitness of prostheses that were manufactured mainly based on Caucasian dimensions. Objectives: To evaluate the distal femur morphology of the Iranian population at the level of standard cuts simulated via computed tomography. Patients and Methods: During 2013, 150 consecutive patients (96 males and 54 females) from the outpatient Department of Orthopedic Surgery of Rasoul Akram Hospital with knee CT scans were studied. We entered cases with apparent normal extremity alignment and bone maturity. Exclusion criteria were history of fracture or conditions affecting knee profile. Standard cuts were simulated on the CT scan using the Marco Pacs program. For each bone, anteroposterior (AP), mediolateral (ML), and aspect ratio (ML/AP) were measured. Values were compared with the sizing of four currently available prostheses. Results: The mean age of the patients was 43 years (range: 17 to 80). All isolated parameters were higher in men significantly (P < 0.001). However, the aspect ratio did not show any significant difference (1.51 ± 0.11 vs 1.46 ± 0.1), suggestive of a similar configuration of distal femur profiles between genders. Ultimately, close correlations were observed among simulated cuts and size-matched femoral components of the prostheses. For females, however, components were mostly overhang mediolaterally except for one gender-specific subset. Decrement in the aspect ratio for larger knees was another mismatch with current prostheses that preserve an almost constant ratio throughout all sizes. Conclusions: Our findings may be applied by manufacturers to design prostheses more compatible with Asian populations. Alterations to the shape of components should be considered to provide optimal coverage. © 2016, Iranian Red Crescent Medical Journal

New method for fixation point of tibialis posterior tendon transfer

Background: The transfer of the tibialis posterior tendon to the dorsum of foot can restore the function of the paralyzed dorsiflexor muscles of the foot and ankle. In order to reduce the wound complication in the insertion site of tendon to bone by a plantar knop we used a new method of fixation by an absorbable screw inserted dorsally. Methods: we performed this operation on 15 patients in a 3 years period. All patients had drop foot deformity due to irreversible lesions of the peroneal nerve. The inclusion criteria was the peroneal nerve palsy that was not improved after 18 months even by using nerve releasing or nerve repairing. All patients were evaluated after 6 months for ankle function and wound complications. Result: Of 15 patients one was excluded from study. At 6 month ten patients got excellent score (66) and 4 good score (26) further ankle function. There was no wound complication at insertion site. Conclusion: This simple modification for insertion site fixation had good result in restoring ankle function whiles eliminated the possibility of plantar pressure sores caused by fixation knop

Effect of gamma irradiation on Cysticercusbovisin infested cattle carcasses

Taeniasis is one of the parasitic zoonotic diseases that could transmit through the consuming of semi-cooked or raw beef infested with Cysticercosebovis. Irradiation as a safe approach can be applied in order to eliminate parasites from foods. It can be used as a control method to prevent parasitic foodborne diseases. Therefore, in this study the cattle muscles containing live cysts were selected from two slaughterhouses of Alborz province and were subjected for gamma irradiation with different doses (0.5, 0.6, 0.7, 0.8, 0.9, 1 and 1.5) KGY. Afterwards, the samples were stained with Eosin Methylene-Blue and were observed with light microscope to determine the viability of the cysts. The analysis of data was conducted with SPSS version 22. The results indicated that 0.8, 0.9, 1 and 1.5 KGY doses were capable to inactivate viable cysts significantly, with 72%, 82.6%, 90.9% and 91.6%, respectively. Therefore, 1 KGY is recommended as appropriate dose for elimination of C. bovis

Evidence for a dynamic role of the linker histone variant h1x during retinoic acid-induced differentiation of nt2 cells

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