Ali Zamani

Lithium's effect on bone mineral density.

Lithium salts are widely used in treating psychiatric patients. Lithium may be associated with hyperparathyroidism, a risk factor for osteoporosis. However, the data on the effect of lithium on bone mass are conflicting. We assessed bone mineral density with dual-energy X-ray absorptiometry at the hip and lumbar spine in 75 lithium treated outpatients and 75 normal subjects matched for age, sex and body mass index. Serum total calcium, intact parathyroid hormone (PTH), estradiol, osteocalcin, total alkaline phosphatase (ALP) and C-telopeptide (CTX) in addition to fasting urinary calcium excretion were also determined in both groups. The mean (+/-SD) bone density in lithium treated patients was 4.5% higher at the spine (P<0.05), 5.3% higher at the femoral neck (P<0.05) and 7.5% higher at the trochanter (P<0.05). In addition, lithium treated patients had lower serum total ALP (P<0.005), lower serum osteocalcin (P<0.005) and lower serum CTX (P<0.05) but the total calcium, PTH and urinary calcium excretion did not differ significantly between patients and controls. In conclusion, our results suggest that maintenance therapy with lithium carbonate may preserve or enhance bone mass. These data also suggest a lower bone turnover state in those receiving lithium.

EFFECTS OF HYPERHOMOCYSTEINEMIA DURING THE GESTATIONAL PERIOD ON OSSIFICATION IN RAT EMBRYO

Severe hyperhomocysteinemia, as seen in classic homocystinuria, is associated with several skeletal malformations and osteopenia. Moreover, hyperhomocysteinemia during pregnancy has been associated with multiple developmental defects in the fetus. This study was undertaken to determine whether offspring of hyperhomocysteinemic mothers have demonstrable changes in bone volume and the epiphyseal growth plate. Ten adult female Sprague-Dawley rats were randomly assigned to the control or experimental group. The experimental group received 100 mg/kg/day of homocysteine in their drinking water for 3 weeks before mating and for the total duration of pregnancy. In each group, three pups per mother were randomly selected. The histomorphometric properties of tibial, radial and vertebral growth plates of newborn rats and the volume fraction of bone were compared between groups. The plasma homocysteine concentration at the end of study was significantly higher in dams in the experimental group (16.42+/-1.5 vs. 4.7+/-1.7 mumol/L, P<0.05). In offspring born to dams given the homocysteine supplement, the volume fraction of bone in the tibia (30.7+/-1.5% vs. 36.8+/-1.9%, P<0.05), radius (29.6+/-1.1% vs. 37.4+/-2%, P<0.05) and vertebra (34.4+/-1.8% vs. 41+/-1.9%, P<0.05) were significantly decreased whereas vertical heights of proliferative (423+/-25.1 vs. 301.8+/-28.1 microm for radius and 131.9+/-5.9 vs. 107.8+/-3.5 microm for vertebra) and hypertrophic zones (213.1+/-12 vs. 163.3+/-7.5 microm for tibia, 153.2+/-7.7 vs. 121.1+/-7.9 microm for radius and 112+/-9.9 vs. 88.4+/-10.1 microm for the vertebra) were increased (P<0.05). The results showed that the administration of homocysteine caused osteopenia in newborn rats. In addition, these data suggest that hyperhomocysteinemia may induce disruption of normal development of epiphyseal cartilage in the rat embryo.

Azelnidipine, a new calcium channel blocker, promotes skin wound healing in diabetic rats.

OBJECTIVE Impaired wound healing in diabetes is associated with decreased nitric oxide (NO) bioavailability in wound tissue. We hypothesized azelnidipine (AZL), a new calcium channel blocker with antioxidant properties, would enhance wound healing in streptozotocin-induced diabetic rats by restoring NO synthesis. METHODS Twelve male rats were taken as non-diabetic group. Twenty four rats were taken and caused to be diabetic by a single streptozotocin injection. Diabetic rats were divided randomly to two groups: control and treatment. Half of non-diabetic and also diabetic rats (in each group of control and treatment) randomly served as excisional-wound model and the other half as nitrite-measurement model. Six weeks after causing diabetes, the excisional wound model underwent dorsal full-thickness excisional wounds (1 × 1 cm). After wound healing completion, full-thickness skin samples (1 × 1 cm) were taken from the wound sites for evaluation of stereological parameters. The nitrite-measurement model (6 wk after causing diabetes) underwent insertion of subcutaneous polyvinyl alcohol sponges in dorsum. The rats were killed 2 wk post-wounding, and wound fluid was analyzed. In the study, after wounding, the treatment groups were gavaged with AZL (3 mg/kg/d) and control and non-diabetic groups with AZL vehicle till euthanasia. RESULTS AZL accelerated wound healing rate and also improved wound fluid NO level toward normal value in diabetic rats. Volume density of collagen fibers, numerical density of fibroblasts, and length density of vessels were increased in AZL-treated rats compared with control group. CONCLUSION AZL administration promotes diabetic wound healing by stimulating NO production and enhancing histologic processes central to normal wound healing.

Folic acid may be a potential addition to diabetic foot ulcer treatment - a hypothesis.

Delayed wound healing in diabetes is a challenging medical and societal problem for which there is currently no efficacious treatment. One of the major contributors of this problem is nitric oxide (NO) deficiency. NO is a critical signalling molecule essential for normal wound repair. Sustained hyperglycaemia in diabetes leads to increased vascular superoxide production, which inactivates NO and causes vascular dysfunction. New therapeutic regiments and strategies to enhance endothelial NO production are a new hope to improve impaired diabetic wound healing. One of the agents that have the ability to improve endothelial NO generation in diabetic patients is folic acid. Folic acid ability to conserve NO bioactivity may be due to homocysteine‐lowering effects of folates, antioxidant actions and effects on cofactor availability. Considering these data, we hypothesised that folic acid supplementation may ameliorate delayed diabetic wound healing by increasing NO bioavailability. The potential of exogenous folic acid as an inexpensive and safe oral therapy stimulates ongoing investigations.

Design and Manufacture a Haptic System to Rehabilitate the Muscles of the Hand

The paper’s objective is to fabricate a novel haptic system for hand muscular rehabilitation applications after hemiplegia that happens after stroke. This prototype is categorised as end-effectors. By using this equipment, patient can perform both active range of motion and passive range of motion. Each rehabilitation device equipped haptic technology for evaluation of force exerted by patient’s limb using multi-axial force sensors. Unlike previous proposed devices and state of the art devices, our proposed device evaluates force exerted only receiving feedback of haptic device the current draw of DC motor. In fact, no force sensor has been used in our proposed haptic device.

Accuracy of software designed for automated localization of the inferior alveolar nerve canal on cone beam CT images.

OBJECTIVES The aim of this study was to design and evaluate a new method for automated localization of the inferior alveolar nerve canal on CBCT images. METHODS The proposed method is based on traversing both panoramic and cross-sectional slices. For the panoramic slices, morphological skeletonization is imposed, and a modified Hough transform is used while traversing the cross-sectional slices. A total of 40 CBCT images were randomly selected. Two experts twice located the inferior alveolar nerve canal during two examinations set 6 weeks apart. Agreement between experts was achieved, and the result of this manual technique was considered the gold standard for our study. The distances for the automated method and those determined using the gold standard method were calculated and recorded. The mean time required for the automated detection was also recorded. RESULTS The average mean distance error from the baseline was 0.75 ± 0.34 mm. In all, 86% of the detected points had a mean error of <1 mm compared with those determined by the manual gold standard method. CONCLUSIONS The proposed method is far more accurate and faster than previous methods. It also provides more accuracy than human annotation within a shorter time.

ScintSim1 : A new Monte Carlo simulation code for transport of optical photons in 2D arrays of scintillation detectors

Two-dimensional (2D) arrays of thick segmented scintillators are of interest as X-ray detectors for both 2D and 3D image-guided radiotherapy (IGRT). Their detection process involves ionizing radiation energy deposition followed by production and transport of optical photons. Only a very limited number of optical Monte Carlo simulation models exist, which has limited the number of modeling studies that have considered both stages of the detection process. We present ScintSim1, an in-house optical Monte Carlo simulation code for 2D arrays of scintillation crystals, developed in the MATLAB programming environment. The code was rewritten and revised based on an existing program for single-element detectors, with the additional capability to model 2D arrays of elements with configurable dimensions, material, etc., The code generates and follows each optical photon history through the detector element (and, in case of cross-talk, the surrounding ones) until it reaches a configurable receptor, or is attenuated. The new model was verified by testing against relevant theoretically known behaviors or quantities and the results of a validated single-element model. For both sets of comparisons, the discrepancies in the calculated quantities were all <1%. The results validate the accuracy of the new code, which is a useful tool in scintillation detector optimization.