Therapeutic effect of 5-ASA and hesperidin-loaded chitosan/Eudragit® S100 nanoparticles as a pH-sensitive carrier for local targeted drug delivery in a rat model of ulcerative colitis.

Ulcerative colitis (UC) is an idiopathic disease characterized by colonic mucosal tissue destruction secondary to an excessive immune response. We synthesized pH-sensitive cross-linked chitosan/Eudragit® S100 nanoparticles (EU S100/CS NPs) as carriers for 5-aminosalicylic acid (5-ASA) and hesperidin (HSP), then conducted in-vitro and in-vivo studies and evaluated the therapeutic effects. In-vitro analysis revealed that the 5-ASA-loaded EU S100/CS NPs and the HSP-loaded EU S100/CS NPs had smooth and curved surfaces and ranged in size between 250 and 300 nm, with a zeta potential of 32 to 34 mV. FTIR analysis demonstrated that the drugs were loaded on the nanoparticles without significant alterations. The loading capacity and encapsulation efficiency of loading 5-ASA onto EU S100/CS NPs were 25.13 % and 60.81 %, respectively. Regarding HSP, these values were 38.34 % and 77.84 %, respectively. Drug release did not occur in simulated gastric fluid (SGF), while a slow-release pattern was recorded for both drugs in simulated intestinal fluid (SIF). In-vivo macroscopic and histopathological examinations revealed that both NPs containing drugs significantly relieved the symptoms of acetic acid (AA)-induced UC in Wistar rats. We conclude that the synthesized pH-sensitive 5-ASA/EU S100/CS NPs and HSP/EU S100/CS NPs offer promise in treating UC.

The association between iris color and refractive errors in children.

This study aimed to evaluate the association between iris color and refractive errors in children aged 6-12 years. This cross-sectional study was based on data obtained from the first phase of the Shahroud Schoolchildren Eye Cohort Study. The target population was 6 to12 year-old students living in urban and rural areas. Iris colors were classified by comparing eye colors with close-up images of iris colors. Myopia was defined as a spherical equivalent (SE) ≤ - 0.5 diopter and hyperopia was defined as SE ≥ 2 diopter in cycloplegic refraction. The association of iris color with hyperopia and myopia was investigated by fitting two separate multiple logistic regression models adjusted for place of residence, age, sex, and times for outdoor activity and near work. Among the 5394 participates with the mean age of 9.7 year, the prevalence of myopia and hyperopia was 4.8% and 4.7% respectively. The number and proportion (in parentheses) of amber, light blue, light brown, dark brown, gray, green and hazel iris colors were 19(0.4%), 26(0.5%), 645(12.0%), 4517(83.7%), 4(0.1%), 59(1.1%), and 124(2.3%) respectively. Compared to dark brown, the odds ratios and 95% confidence intervals (in parentheses) of myopia were 4.8(1.2-18.7), 0.8(0.1-5.8), 1.0(0.7-1.5), 0.4(0.1-2.7) and 0.6(0.2-1.8) for amber, light blue, light brown, green and hazel iris colors in multiple logistic regression model. No significant association was observed between iris colors and hyperopia. This study shows that amber iris is significantly associated with higher odds of myopia. These children should be further monitored and examined. More studies with higher sample size in all iris colors are recommended.

Synthesis, characterization and hepatoprotective effect of silymarin phytosome nanoparticles on ethanol-induced hepatotoxicity in rats.

Introduction: Silymarin proved to be a beneficial herbal medicine against many hepatic disorders such as alcoholic liver disease (ALD). However, its application is restricted due to its low bioavailability and consequently decreased efficacy. We herein used a nano-based approach known as "phytosome", to improve silymarin bioavailability and increase its efficacy. Methods: Phytosome nanoparticles (NPs) were synthesized using thin film hydration method. NPs size, electrical charge, morphology, stability, molecular interaction, entrapment efficiency (EE %) and loading capacity (LC %) were determined. Moreover, in vitro toxicity of NPs was investigated on mesenchymal stem cells (MSCs) viability using MTT assay. In vivo experiments were performed using 24 adult rats that were divided into four groups including control, ethanol (EtOH) treatment, silymarin/EtOH treatment and silymarin phytosome/EtOH, with 6 mice in each group. Experimental groups were given 40% EtOH, silymarin (50 mg/kg) and silymarin phytosome (200 mg/kg) through the gastric gavage once a day for 3 weeks. Biochemical parameters, containing ALP, ALT, AST, GGT, GPx and MDA were measured before and after experiment to investigate the protective effect of silymarin and its phytosomal form. And histopathological examination was done to evaluate pathological changes. Results: Silymarin phytosome NPs with the mean size of 100 nm were produced and were well tolerated in cell culture. These NPs showed a considerable protective effect against ALD through inverting the biochemical parameters (ALP, ALT, AST, GGT, GPx) and histopathological alterations. Conclusion: Silymarin phytosomal NPs can be used as an efficient treatment for ALD.

Protective effects of honey, Apis mellifera meda skorikov, on ischemia-reperfusion induced muscle injury / Efectos protectores de la miel, Apis mellifera meda skorikov, sobre la lesión muscular inducida por isquemia-reperfusión

Honey is a natural antioxidant that its protective effects have been proven against ischemia-reperfusion (IR) injury. The aim of this study was to evaluate the ameliorative effect of Persian Honey, Apis mellifera meda skorikov, on gastrocnemius muscle IR injury. Eighty adult male Sprague-Dawley rats weighing 250-300 g were used. They were divided into ten groups (N=8 per group). The ischemia was conducted with a silk suture 6-0 using the slipknot technique. All groups were rendered in ischemic for 3 h, and reperfused for various times of 3 days (3-day reperfusion), 7 days (7-day reperfusion), 14 days (14-day reperfusion), and 28 days (28-day reperfusion). Half of the groups had experimental honey (5 %) treatment immediately after ischemia. After reperfusion, the rats, based on the grouping, were killed with high doses of anesthetic, and the gastrocnemius muscles were removed and fixed. After the tissue processing, the evaluation of edema and mast cells infiltration was performed with hematoxylin-eosin and toluidine blue staining, respectively. TNF-α was detected with immunohistochemistry method. The amount of TNF-α as an index of acute inflammatory except the 3rd day significantly decreased on the other day of reperfusion (7th, 147th and 287th days). The mast cells infiltration was significantly decreased on 77th and 147th days. The tissue edema was decreased significantly in honey administrated group in the comparison with placebo groups. Honey administration can reduce damage caused by ischemia-reperfusion in the rat gastrocnemius muscle.

La miel es un antioxidante natural; sus efectos protectores han sido probados contra la lesión por isquemiareperfusión (IR). El objetivo de este estudio fue evaluar el efecto de mejora de la miel persa Apis mellifera meda skorikov, en la lesión por IR del músculo gastrocnemio. Se utilizaron 80 ratas Sprague-Dawley macho adultas con un peso entre 250 y 300 g divididas en diez grupos (N = 8 por grupo). La isquemia se realizó con una sutura de seda 6-0 utilizando la técnica slipknot permaneciendo isquémicos durante 3 h. La reperfusión se realizó durante varios tiempos de 3 días, 7 días (reperfusión de 7 días), 14 días (reperfusión de 14 días) y 28 días (28 días reperfusión). La mitad de los grupos recibió tratamiento experimental con miel (5 %) inmediatamente después de la isquemia. Después de la reperfusión, las ratas, fueron sacrificadas con altas dosis de anestésico, y los músculos gastrocnemios fueron removidos y fijados. Después de procesar el tejido, se realizó la evaluación del edema y la infiltración de mastocitos se realizó con tinción de hematoxilina-eosina y azul de toluidina, respectivamente. TNF-α se detectó con el método de inmunohistoquímica. La cantidad de TNF-α como índice de inflamación inflamatoria aguda, excepto en el tercer día, disminuyó significativamente al día siguiente de la reperfusión (7, 14 y 28 días). La infiltración de mastocitos disminuyó significativamente a los 7 y 14 días. El edema tisular disminuyó significativamente en el grupo administrado con miel en comparación con los grupos placebo. El tratamiento con miel puede reducir el daño causado por la isquemia-reperfusión en el músculo gastrocnemio de la rata.

Wharton's Jelly Mesenchymal Stem Cell: Various Protocols for Isolation and Differentiation of Hepatocyte-Like Cells; Narrative Review.

There are several differentiation methods for mesenchymal stem cells (MSCs) into hepatocyte-like cell. Investigators reported various hepatic differentiation protocols such as modifying culturing conditions or using various growth factors/cytokines. In this literature review, we compared different MSCs extraction and isolation protocols from Wharton's jelly (WJ) and explored various MSCs differentiation methods. Various protocols have been recommended for MSCs isolated from WJ, such as enzymatic, enzymatic-explant, and explant methods. In the explant method, valuable time is wasted, but the cost and biological contaminations are reduced and the number of isolated cells is high. However, other features, such as immune phenotype and multiline-age differentiation capacity, do not differ from other methods. There are also several differentiation methods for hepatocyte-like cell including the induction of MSC by cytokines and growth factors, and the differentiation of MSC in 2- and 3-dimensional matrix (2D and 3D). Among several cytokines, hepatocyte growth factor (HGF) and fibroblast growth factor (FGF) are essential. In the early stage of the differentiation, 2D culture is useful, and in the development stage, 3D culture system with HGF and FGF cytokines are more effective in the process of differentiation. Some studies have used 3D culture system in biocompatible scaffolds, such as alginate, collagen, gelatin, and peptide-Gly-Leu-amide (PGLA). In conclusion, Wharton's jelly-Mesenchymal stem cells (WJ-MSCs) can be considered as an appropriate source for hepatocyte differentiation. Moreover, we introduced the explant method as the most effective protocol. This review attempted to highlight factors in hepatocyte differentiation, but the most effective protocol is not still unknown.

Shear bioreactors stimulating chondrocyte regeneration, a systematic review.

It is commonly accepted that the mechanical stimuli are important factors in the maintenance of normal structure and function of the articular cartilage. Despite extensive efforts, the cellular mechanisms underlying the responses of articular chondrocytes to mechanical stresses are not well understood. In the present review, different types of shear bioreactor and potential mechanisms that mediate and regulate the effect of shear on chondrocyte are discussed. For this review, the search of the literature was done in the PubMed, Scopus, Web of sciences databases to identify papers reporting data about shear on chondrocyte. Keywords "shear, chondrocyte, cartilage, bioreactor" were used. Studies published until the first of March 2018 were considered in this paper. The review focused on the experimental studies conducted the effect of shear stress on cartilage tissue in vivo and in vitro. In this review, both experimental studies referring to human and animal tissues were taken into account. The following articles were excluded: reviews, meta-analysis, duplicate records, letters, and papers that did not add significant information. Mechanism of shear stress on chondrocyte, briefly can be hypothesized as (1) altered expression of aggrecan and collagen type II, (2) altered cartilage oligomeric matrix protein (COMP) serum levels, consequently, organizing the arrangement binding of glycosaminoglycans, integrins, and collagen, (3) induction of apoptosis signals, (4) altered expression of integrin.

Calendula officinalis stimulate proliferation of mouse embryonic fibroblasts via expression of growth factors TGFß1 and bFGF.

BACKGROUND: TGF-ß has an important role in the process of wound healing and scar formation. The aim of this study is to determine the effects of ethanolic and methanolic extracts of Calendula officinalis on the expression of TGFß1 and bFGF in the mouse embryonic fibroblast cells (MEFs). METHODS: Calendula officinalis extract was purchased and different substances defined with gas chromatography and mass spectrometry. MEFs were prepared and after incubating for 15 min, cell viability analyzed. TGF ß 1 and bFGF gene expression was evaluated by real-time PCR. TGFß1 and bFGF protein expression analyzed by ELISA. The statistical analysis of data was done by using SPSS software. Differences were considered significant at (P < 0.05). RESULTS: The results of the MTT test showed that the concentrations of 5 µg/ml and10 µg/ml were more suitable for cell proliferation. There was an increase in TGF ß 1 gene expression in the MEFs. Expression of TGF ß 1 gene remains the same after 24 h. Gene expression of bFGF showed a similar pattern with TGF ß 1 expression for both solvents. Analysis of TGFß1 protein expression showed an increase in TGFß1 gene expression in the MEFs. Protein expression of bFGF in the MEFs increased at different concentrations at 12 and 24 h after treatment (P < 0.05 and P < 0.01 respectively). CONCLUSION: Calendula officinalis stimulates proliferation of MEFs. Calendula via increased expression of growth factors (TGFß1 and bFGF) at the first 12 h and a decrease of these factors at 24 h after treatment may ameliorate function of the MEFs in the during wound healing.

Encapsulation of Satureja khuzistanica extract in alginate hydrogel accelerate wound healing in adult male rats.

BACKGROUND: Finding the best dressing for a specific wound had continued from the past to present. The aim of this study was to evaluate the effect of encapsulated extract of Satureja khuzistanica in hydrogel alginate at wound healing. METHODS: Thirty-two male Wistar rats with a puncture wound in the back of the neck skin were divided randomly into four groups including a control group, Satureja khuzistanica-treated group, hydrogel alginate-treated group, and Satureja khuzistanica encapsulated in hydrogel alginate-treated group. Rats were treated for 22 days. The skin samples were taken on 3rd, 7th, 14th, and 22nd days after treatment for light microscopy. Results were analyzed in accordance with Kruskal-Wallis and Friedman test (for histopathology analysis) by using SPSS v.22 software. RESULTS: Macroscopically evaluations and measurement of wound size showed increased wound healing process in the treated groups. The complete improvement was created on the 14th day. The wound site was not observed on the 22nd day. But the wound site was observed on the 22nd day in the control group. Also, comparison of the percentage of wound healing between the treated and control groups on 3rd, 7th, 14th, and 22nd days showed a significant difference (p < 0.05). Comparison of the H&E stained sections in the studied groups showed that treated groups were effective on wound healing in comparison with the control group. CONCLUSIONS: Encapsulated extract of Satureja khuzistanica in hydrogel alginate may accelerate wound improvement and increase the rate of wound healing without scar formation.

Encapsulated explant in novel low shear perfusion bioreactor improve cell isolation, expansion and colony forming unit.

One of most important issue in the field of regenerative medicine is selection of appropriate cells, scaffolds and bioreactors. The present study aimed to investigate the appropriate method for the isolation of human UC-MSCs cells from explant cultured in alginate scaffold within novel perfusion bioreactor. MSCs were isolated with explant method and CD markers such CD73, CD31, CD90 and CD105 as were analyzed by flow cytometry. The culture chamber of the novel perfusion bioreactor was made from Plexiglas and housed the cell/scaffold constructs in the central part and the medium for the whole culture period. The flow behavior within the bioreactor chamber were performed for closed and open bypass systems. The shear stress profiles simulated using CFD modeling. The fluid flow distribution within the bioreactor chamber was performed in PBS solution containing a blue colorant. UC explants were resuspended in sodium alginate and were allowed to polymerize and placed in the perfusion bioreactor and cultured. MSCs were positive for mesenchymal markers such as CD73 and CD31. All 3D Perfusion bioreactor parts, except peristaltic pump was sterilizable by autoclaving. Results of CFD indicated very low wall shear stress on surface of culture chamber at flow rate 2 ml/min. The maximum wall shear stress was 1.10 × 10-3 m/s = 0.0110 dyne/cm2 (1 Pa = 10 dyne/cm2). The fluid flow distribution within the alginate gel initially exhibited oscillation. In comparison, when encapsulated explants were placed in the perfusion bioreactor, cell proliferation appeared faster (4.6 × 1011 ± 9.2 × 1011) than explants cultures in 2D conventional culture method (3.2 × 1011 ± 1 × 1011). Proliferated cell formed several colonies. Migration of chondrocytes to the periphery of the alginate bead was visible after 1 week of culture. Perfusion bioreactor with low shear stress and alginate hydrogel improve cell isolation and expansion and eliminate cell passaging and enhance colony forming unit of UC-MSCs.

Impact of instructor-provided notes on the learning and exam performance of medical students in an organ system-based medical curriculum.

PURPOSE: The present study aimed to explore the impact of instructor-provided notes on the learning and exam performance of medical students. PATIENTS AND METHODS: The participants involved in this study were the first year medical students who enrolled in the auditory system course in the second semester of the academic years 2012-2016 (N=380, 170 males and 210 females). The medical students were divided into two groups: teaching without guided note-taking approach and teaching with guided note-taking approach. To measure the note-taking process of students, quantity and quality of notes were recorded and scored. At the end of the course, the questionnaire was administered to all students in the experimental group in order to cover student's satisfaction with the instructor-provided notes. Chi-squared tests using SPSS software were performed on categorical variables for comparison of exam score between classes with/without guided note-taking approach. A P<0.05 was considered as statistically significant. RESULTS: When compared, more females (75%) than males were included in the note-taking process. Females wrote more information in greater detail than males. In the control group, only 58 students from 193 students attempted to take notes, but in the experimental group, all of the students were encouraged to complete guided notes and take notes. When students were provided with guided notes, the structure of their notes reflected more outline, examples, verbatim and words than the control group. The students connected the main idea with their details in the spaces of the guided notes. The course final exam performance for the class with the guided note-taking approach was statistically significantly higher than that for the class without a guided note-taking approach (χ2) = 10.542; P=0.023). Nearly all of the students agreed to receive instructor-provided notes before class. CONCLUSIONS: Findings of the present study indicated that when students are provided with guided notes, their note-taking process develops; consequently improving students' learning and exam performance.

Current status of stem cell therapy, scaffolds for the treatment of diabetes mellitus.

Diabetes mellitus (DM) remains the 7th leading cause of death in the world. Daily insulin injection is one component of a treatment plan for people with Diabetes mellitus type 1 (T1DM) that restores normal or near-normal blood sugar levels. However, Insulin treatment depends upon a variety of individual factors and leads to poor and drastic glycemic control. The need for an effective cell replacement strategy will be the aim of future clinical trials. Therefore, the aim of this systematic review is to outline the latest advances in scaffolding and stem cell therapy as a non-pharmacologic treatment for T1DM. It also emphasizes on some pancreas differentiation protocols and the clinical trials associated with stem cell therapy regarding T1DM in vitro and in vivo.

Protective effects of persian honey, Apis Mellifera Meda Skorikov on side effects of chemotherapy and ischemia/reperfusion induced testicular injury.

Introduction The aim of the present study was to survey the protective effect of pretreatment with Persian honey on amelioration of side effects of chemotherapy and ischemia/reperfusion induced testicular injury. Materials and methods Forty adult's male wistar rats were divided into four groups of ischemia-reperfusion (IR), honey + ischemia-reperfusion (HIR), Busulfan (B) and Busulfan intraperitoneally+ honey (BH). The seminiferous tubules were rated for their modified spermatogenesis index (SI) by Johnsons score. Detection of single- and double-stranded DNA breaks at the early stages of apoptosis was performed using the in-situ cell death detection kit. Total serum concentration of Follicle-stimulating hormone (FSH) , Luteinizing hormone (LH) and testosterone was measured using ELISA. All data were expressed as mean ± SD and significance was set at p≤0.05. Results Honey improved SI in the HIR and BH groups and serum levels of FSH and LH in the BH and HIR groups (p<0.001). Also, serum levels of testosterone were significantly higher in BH and HIR groups. But, apoptotic cells in IR and B groups significantly increased (p<0.001), while in HIR and BH groups, the number of apoptotic cells decreased and the positive cells of TUNEL (TdT-mediated dUTP-X nick end labelling) staining were detected in spermatocytes and spermatid. Discussion Pretreatment with honey protect testis against chemotherapy and testicular IR injury, increase FSH and LH and testosterone and decrease the cellular damage and apoptosis. Honey can decrease the side effects of chemotherapy on reproductive system and prevent sterility.

Coenzyme Q10 protects skeletal muscle from ischemia-reperfusion through the NF-kappa B pathway.

OBJECTIVE: Coenzyme Q10 (CoQ10) has antioxidant and anti-inflammatory activity. The aim of this study was to investigate the effects of CoQ10 on the inhibition of nuclear factor-kappa B (NF-κB) activation during ischemia-reperfusion (I/R) of skeletal muscle. METHODS: For ischemia induction, the animals were anesthetized and the external iliac vessels blocked for three hours. CoQ10 or vehicle was given intraperitoneally during ischemia, just before reperfusion. Four groups received 3,7,14 and 28 days' reperfusion, respectively, after the intraperitoneal injection of CoQ10 and four corresponding groups received vehicle only. After reperfusion, the gastrocnemius muscles were removed, fixed and stained for the analysis of edema and mast cell infiltration. RESULTS: Immuno-histochemistry staining was performed for the detection of tumor necrosis factor alpha (TNF-α) and NF-κB. CoQ10-treated groups showed a significant decrease of mast cell infiltration in the gastrocnemius muscle and edema as compared with the corresponding non-treated groups. Also, CoQ10-treated groups showed a significant TNF-α and NF-κB expression decrease when compared to the corresponding non-treated controls. The results of this study showed CoQ10 administration with ischemia decreased interstitial edema, degeneration of muscle fibers and infiltration of mast cells. CONCLUSIONS: It seems that CoQ10 has inhibitory effects on NF-κB and TNF-α activation.

Quercetin ameliorates peripheral nerve ischemia-reperfusion injury through the NF-kappa B pathway.

This study aimed to investigate the protective effect of quercetin against ischemia-reperfusion (IR) injury induced in the sciatic nerve of the rat. Quercetin (20 mg/kg) was given during ischemia just before reperfusion. Four groups of rats (Q+IR3, Q+IR7, Q+IR14, and Q+IR28) received 3, 7, 14, and 28 days of reperfusion, respectively, after the intraperitoneal injection of quercetin. After reperfusion, a behavioral test was performed and the sciatic functional index was calculated. Each sciatic nerve was stained to check for edema and ischemic fiber degeneration. Immunohistochemical staining was performed to detect TNF-alpha and NF-kappa B, and TUNEL staining was carried out to detect apoptosis. The Q+IR3, Q+IR7, and Q+IR14 groups showed significantly increased behavioral scores and ameliorated sciatic functional index values compared to IR-injured rats that received vehicle alone during ischemia and then the same period of reperfusion. The Q+IR3, Q+IR7, Q+IR14, and Q+IR28 groups presented significant ischemic fiber degeneration (IFD), TNF-alpha expression, and apoptosis as compared with the IR-injured and perfused rats that did not receive quercetin. The Q+IR3, Q+IR7, and Q+IR28 groups also exhibited significantly decreased NF-kappa B expression (p < 0.001, p = 0.001, p = 0.026) as compared with the IR-injured rats that were perfused but did not receive quercetin. These results imply that quercetin may be beneficial in the treatment of sciatic IR injury because of its antiapoptotic and antiinflammatory effects and its ability to decrease the expression of NF-kappa B.

Persistent median artery in the carpal tunnel and anastomosis with superficial palmar arch.

Persistent median artery (PMA) in present cadaver originated from the brachial artery and anastomosed with the superficial palmar arch (SPA). As the PMA may be the cause of carpal tunnel syndrome and SPA is the main source of arterial supply, knowledge of which are important for the hand surgical interventions.

Staining of cerebellar cortex granular layer interneurons with natural dye of Madder.

BACKGROUND: The objective of the present study was an investigation of root Rubia Tinctorum (Madder) as a natural dye to identification of granular layer interneurons of the rat cerebellum. METHODS: Seven to ten micrometre sections were collected from the cerebellum and stained only with Madder for 2, 24 and 48 h. Other sections were stained with Madder then with hematoxyllin, cresyl violet, eosin, light green. Microscopic identification of cells was performed based on cell morphology, reaction and binding of with the dye. All data were expressed as mean ± SD in and significance was set at p ≤0.05. RESULTS: Madder with alum as mordant resulted a deep red staining of interneurons. Unipolar brush cells (UBCs) were observed with a cell body diameter intermediate between granule and Golgi cells in the superficial layer of the granular layer. Golgi cells were identified almost as large as Purkinje cells with irregular rounded or polygonal morphology. Lugaro cells were observed as spindle-shaped cells adjacent to Purkinje layer. CONCLUSION: Results of the present study showed that mader could stain granular layer interneurons in cerebellum cortex of rat.

Fluid-induced low shear stress improves cartilage like tissue fabrication by encapsulating chondrocytes.

In the recent years, there has been considerable development in the regenerative medicine, which aims to repair, regenerate, and improve injured articular cartilage. The aim of the present study was to investigate the effect of flow-induced shear stress in perfusion bioreactor on alginate encapsulating chondrocytes. The shear stress imposed on the cells in the culture chamber of bioreactor was predicted with computational fluid dynamic. Bovine nasal chondrocytes were isolated and expanded to obtain a pellet. The cell pellet was resuspends in alginate solution, transferred to the culture chamber, and dynamically cultured under direct perfusion. At the end of culture, tissue constructs were examined histologically and by immunohistochemistry. The results of computational fluid dynamic modeling revealed that maximum wall shear stress was 4.820 × 10(-3) Pascal. Macroscopic views of the alginate/chondrocyte beads suggested that it possessed constant shape but were flexible. Under inverted microscope, round shape of chondrocyte observed. Cell distribution was homogeneous throughout the scaffold. Tissue construct subjected to shear showed morphological features, which are characteristic for natural cartilage. Immunohistochemistry results revealed immunopositivity for type II collagens in tissue constructs samples. Flow induced shear stress in the perfusion bioreactor and chnondrocyte encapsulation provide environment to support cell growth, and tissue regeneration and improve cartilage like tissue fabrication.

Direct expansion of chondrocytes in a dynamic three-dimensional culture system: overcoming dedifferentiation effects in monolayer culture.

Maintenance of the chondrocyte phenotype during cell culture to successful transplantation of cartilage is highly challenging. However, the question of the optimal method of isolation and expansion of chondrocytes for tissue engineering has not previously been investigated in detail. The present study investigates the possibility of improved in vitro maturation of chondrocytes through a method of cell duplication that does not subject chondrocytes to dedifferentiation. The culture chamber of the bioreactor was designed with an internal geometry that mimicked that of a ball-and-socket joint. The shear stresses exerted on the surface of the bioreactor chamber wall by a peristaltic pump operating at flow rates of 2 mL/min were simulated by computational fluid dynamics (CFD) modeling. Small pieces (5 mm) of calf nasal septum cartilage were prepared and exposed to trypsin and 0.2% collagenase type II in Dulbecco's modified Eagle's medium (DMEM), which was then replaced with unsupplemented DMEM. The cells were harvested and then immediately seeded into alginate scaffolds. All cell-seeded scaffolds were cultured for 3-5 days in flasks, then transferred to the bioreactor and dynamically cultured for 3-5 days under direct perfusion with 2 mL/min DMEM. After culture in the bioreactor, all cell-seeded scaffolds were fixed in Bouin fixative, dehydrated, cleared, and then embedded in paraffin wax. Sections of 5-7 µm were cut and stained with several histochemical staining methods. The results of CFD modeling indicated peak velocity and maximum wall shear stress were 3.406 × 10(-3) m/s and 0.0482 dyn/cm(2) (1 Pa = 10 dyn/cm(2) ), respectively. Histological examination of chondrocytes cultured in the bioreactor revealed evidence of cartilage-like tissue with lacuna and chondron formation. The cartilage-like matrix had accumulated within the lumen of clusters of round mature chondrocytes, with the cells surrounding the metachromatic territorial matrix-staining strongly with toluidine blue. Sections stained with the hematoxylin/safranin O/fast green and Alcian blue/nuclear fast red methods show sulfated glycosaminoglycans in the matrix (produced by the chondrocytes) as intense red and blue, respectively. The findings of the present study indicate that incubation in DMEM supplemented with enzymes followed by explant isolation and culture in a bioreactor is the optimal method for the direct expansion of chondrocytes for cartilage tissue engineering.

The Incomplete Superficial Palmar Arch.

INTRODUCTION: Superficial palmar arch (SPA) is dominant vascular structure in palm of hand. In present study we described a case of Ulnar / Radiopalmar pattern of incomplete SPA in an Iranian cadaver. When the SPA is complete, the superficial palmer branches of the radial artery contribute to the ulnar artery. In incomplete type of SPA, there was no anastomosis between the ulnar and radial arteries (UA, RA). CASE REPORT: In the present case, the brachial artery divided into RA and UA at the cubital fossa. There was no anastomosis between radial and ulnar arteries (RA, UA) in the palm of the hand. UA gave three palmar digital arteries; proper palmar digital artery and two common palmar digital arteries. RA gave proper palmar digital artery and arteria princeps pollicis. CONCLUSION: Knowledge of anatomical variation of SPA is important for the hand surgical interventions and this is a very rare variation which can be easily tested clinically by Allen's test.

Design and fabrication of anatomical bioreactor systems containing alginate scaffolds for cartilage tissue engineering.

The aim of the present study was to develop a tissue-engineering approach through alginate gel molding to mimic cartilage tissue in a three-dimensional culture system. The perfusion biomimetic bioreactor was designed to mimic natural joint. The shear stresses exerting on the bioreactor chamber were calculated by Computational Fluid Dynamic (CFD). Several alginate/bovine chondrocyte constructs were prepared, and were cultured in the bioreactor. Histochemical and immunohistochemical staining methods for the presence of glycosaminoglycan(GAG), overall matrix production and type II collagen protein were performed, respectively. The dynamic mechanical device applied a linear mechanical displacement of 2 mm to 10 mm. The CFD modeling indicated peak velocity and maximum wall shear stress were 1.706×10(-3)m/s and 0.02407 dyne/cm(2), respectively. Histochemical and immunohistochemical analysis revealed evidence of cartilage-like tissue with lacunas similar to those of natural cartilage and the production of sulfated GAG of matrix by the chondrons, metachromatic territorial matrix-surrounded cells and accumulation of type II collagen around the cells. The present study indicated that when chondrocytes were seeded in alginate hydrogel and cultured in biomimetic cell culture system, cells survived well and secreted newly synthesized matrix led to improvement of chondrogenesis.