Finite Element Model of Ocular Adduction by Active Extraocular Muscle Contraction

PurposeIn order to clarify the role of the optic nerve (ON) as a load on ocular rotation, we developed a finite element model (FEM) of incremental adduction induced by active contractility of extraocular muscles (EOMs), with and without tethering by the ON.MethodsThree-dimensional (3-D) horizontal rectus EOM geometries were obtained from magnetic resonance imaging of five healthy adults, and measured constitutive tissue properties were used. Active and passive strain energies of EOMs were defined using ABAQUS (Dassault Systemes) software. All deformations were assumed to be caused by EOM twitch activation that rotated the eye about a fixed center. The medial rectus (MR) muscle was commanded to additionally contract starting from 26 degrees adducted position, and the lateral rectus (LR) to relax, further adducting the eye either with or without loading by the ON. Tridimensional heat maps were generated to represent the stress and strain distributions.ResultsTensions in the EOMs were physiologically plausible during incremental adduction. Force in the MR increased from 10 gm at 26 degrees adduction to approximately 28 gm at 32 degrees adduction. Under identical MR contraction, adduction with ON loading reached 32 degrees but 36 degrees without it. Maximum and minimum principal strains within the MR were 16% and 22%, respectively, but when ON loading was included, resulting stress and strain were concentrated at the optic disc.ConclusionsThis physiologically plausible method of simulating EOM activation can provide realistic input to model biomechanical behavior of active and passive tissues in the orbit to clarify biomechanical consequences of ON traction during adduction.     

Potential effect of opium addiction on lipid profile and blood glucose concentration in type 2 diabetic patients in Iran

Background: Diabetes is one of the most common chronic diseases in the world. People believe that opium improves blood glucose and lipid profiles in these patients and controversial studies show the effect of consumption of opium in controlling these indices. Accordingly, this study aimed to compare the serum levels of blood indices such as fasting blood glucose (FBS), Hemoglobin A1c (HbA1c) and lipid profile in opium users and non-users in type ΙΙ diabetic patients.

Methods: In this cross-sectional study, among type II diabetic patients referred to the Diabetes Clinic of Birjand 45 opium users and 135 non-users were selected and entered the study by the convenience sampling method.

Results: The results of this study showed that the mean serum levels of FBS, HbA1c, and serum lipid profiles were not significantly different between the two groups of opium users and non-users, but the levels of triglyceride (TG) were significantly 0.18 unit higher in the opium users, compared to non-opium users.

Conclusion: According to the results, the use of opium does not affect the indices of blood glucose, HbA1c and serum lipid profiles except triglyceride in diabetic patients. The general belief that opioid use reduces biochemical indices does not seem to be correct.

Abbreviations: FBS: fasting blood sugar; HbA1c: Hemoglobin A1c; LDL: low-density lipoprotein; HDL: High-density lipoproteins; HDL-C: High-density lipoproteins-cholesterol; BMI: Body mass index; IQR: Inter quartile range; TG: triglyceride; TC: total cholesterol; NS: non-significant; S: significant; ATN: Acute tubular necrosis     

Effects of dietary red clover on blood factors and cardiovascular fatty streak formation in hypercholesterolemic rabbits

Phytoestrogens with a biological activity like estradiol are naturally found in many plants. This study was designed to investigate the effect of red clover, a phytoestrogen-rich member of the legume family (Trifolium pratense) on the development of atherosclerosis in male hyperlipidemic rabbits. Twenty rabbits were semi-randomly distributed into four groups of five each. Two groups received either normal diet or normal diet supplemented with red clover. Two other groups received similar diets to both of which 1% cholesterol was added. Dietary use of red clover (RC) in hyperlipidemic rabbits significantly decreased C-reactive protein (CRP), triglyceride (TG), total cholesterol and LDL-cholesterol (LDL-C) whereas, HDL-cholesterol (HDL-C) was significantly increased in those animals (p < 0.05). Fatty streak formation was also significantly lower in aorta and left and right coronary arteries in the same animals due to use of dietary RC supplementation. These findings suggest that dietary RC may reduce cardiovascular risk factors.     

Quantitative analysis of TEM-8 and CEA tumor markers indicating free tumor cells in the peripheral blood of colorectal cancer patients

Background

Colorectal cancer (CRC) remains the third most common cancer in the world. Approximately in 50 percent of patients, metastatic disease is a major cause of death. Therefore, early diagnosis of CRC is crucial for a successful outcome. For the detection of circulating cancer cells, this study applied a sensitive method that employed specific tumor markers for early detection.

Methods

A total of 80 blood samples from 40 CRC patients and 40 age-matched healthy controls were collected for the study. The circulating mRNA levels of two CRC tumor markers, tumor endothelial marker 8 (TEM-8) and carcinoembryogenic antigen (CEA) were evaluated using an absolute quantitative real-time PCR assay in a Stratagene Mx-3000P real-time PCR system. GAPDH was used as the endogenous control.

Results

TEM-8 and CEA were primarily detected more in the CRC patients rather than in the controls: 22/40 vs 9/40, p=0.009 and 30/40 vs 11/40, p=0.00054, respectively. In the CRC patients, the mRNA level of these markers was significantly higher in comparison to the normal controls (p=0.018 and 0.01). The overall sensitivity of this panel was 65% with a specificity of 75%. Statistical analysis for demographic variants did not reach significant values.

Conclusions

TEM-8 and CEA markers were detected more frequently and in significantly higher levels in the blood samples of patients compared with samples from age-matched healthy controls. The copy number of CEA and TEM-8 mRNA, as detected by a real-time quantitative PCR, appears to be a promising marker for evaluating the risk of tumor spread.     

Effects of folic acid supplementation on C-reactive protein: A systematic review and meta-analysis of randomized controlled trials

Background and aim

Given the contradictory results of previous randomized controlled trials (RCTs), we performed a systematic review and meta-analysis to quantify and summarize the effects of folic acid supplementation on C-reactive protein (CRP).

The lower incisors as a predictor for the size of unerupted canine and premolars in the Iranian ethnicity

The purpose of this study was to find the correlation coefficients between the mesiodistal widths of the permanent mandibular incisors and the permanent canine and premolars for each quadrant and establish a regression equation for prediction of the sum of canine and premolars based on the dimension of the lower incisors. 90 patients 12–20 years old (45 females and 45 males) were selected. The mesiodistal crown diameters of the permanent teeth were measured. The correlation coefficients between the permanent mandibular incisors and the permanent canine and premolars sizes varied from 0.63 to 0.8. An Iranian mixed dentition analysis based on the Tanaka and Johnston method was constructed with linear regression equations; for maxillary arch y = 6.3 + 0.65x (SEE = 0.8 mm) and for mandibular arch y = 5.1 + 0.67x (SEE = 0.8 mm). No significant sexual dimorphism was found in tooth sizes. This study revealed that Iranian population has smaller teeth than white North American. We found that prediction equations of Tanaka and Johnston or Moyers charts cannot accurately predict the size of buccal segment in Iranian population.     

Experiences of Kurdish war-wounded refugees in communication with Swedish authorities through interpreter

Objective

To study experiences of war-wounded Kurdish refugees with respect to cross-cultural communication through interpreters.

Method

Semi-structured interviews were conducted with ten men, aged 31–42. Content analysis was used for analysis and interpretation of data.

Result

War-wounded Kurdish refugees experienced a number of difficulties regarding communication through interpreters, mainly related to the insufficient language link to the Swedish authorities, particularly health care personnel. In many instances, interpreters were selected based on the immigrant's citizenship rather than mother tongue, leading to a more complex, tri-lingual interpretation situation. Differences in cultural background, fear, suspicion and lack of confidence in interpreters were addressed as other problems by the participants.

Conclusion

Interpreter competence and patient confidence in the interpreter are essential for an adequate cross-cultural health communication. Assignment of interpreters should be based on knowledge of the patient's/client's mother tongue, rather than citizenship, and the outcome is improved by a common ethnic and cultural background of interpreter and patient/client. Our study should be considered as a pilot study, and the results should be validated in larger cohorts as well as in other ethnic and language groups.

Practice implications

In order to minimize communication misunderstandings, complicated tri-lingual interpretation situations should be avoided. Interpreters should ideally be assigned according to patient's/client's mother tongue rather than citizenship. Interpreters’ competence and patient's/client's confidence in interpreter may have significant impact on communication outcome.