Hybrid scaffolds of Mg alloy mesh reinforced polymer/extracellular matrix composite for critical‐sized calvarial defect reconstruction

The challenge of developing scaffolds to reconstruct critical‐sized calvarial defects without the addition of high levels of exogenous growth factor remains relevant. Both osteogenic regenerative efficacy and suitable mechanical properties for the temporary scaffold system are of importance. In this study, a Mg alloy mesh reinforced polymer/demineralized bone matrix (DBM) hybrid scaffold was designed where the hybrid scaffold was fabricated by a concurrent electrospinning/electrospraying of poly(lactic‐co‐glycolic acid) (PLGA) polymer and DBM suspended in hyaluronic acid (HA). The Mg alloy mesh significantly increased the flexural strength and modulus of PLGA/DBM hybrid scaffold. In vitro results demonstrated that the Mg alloy mesh reinforced PLGA/DBM hybrid scaffold (Mg‐PLGA@HA&DBM) exhibited a stronger ability to promote the proliferation of bone marrow stem cells (BMSCs) and induce BMSC osteogenic differentiation compared with control scaffolding materials lacking critical components. In vivo osteogenesis studies were performed in a rat critical‐sized calvarial defect model and incorporated a variety of histological stains and immunohistochemical staining of osteocalcin. At 12 weeks, the rat model data showed that the degree of bone repair for the Mg‐PLGA@HA&DBM scaffold was significantly greater than for those scaffolds lacking one or more of the principal components. Although complete defect filling was not achieved, the improved mechanical properties, promotion of BMSC proliferation and induction of BMSC osteogenic differentiation, and improved promotion of bone repair in the rat critical‐sized calvarial defect model make Mg alloy mesh reinforced PLGA/DBM hybrid scaffold an attractive option for the repair of critical‐sized bone defects where the addition of exogenous isolated growth factors is not employed.     

A comparative histological study on the uterovaginal junction in the laying hen in embryonated and non-embryonated egg producers

The uterovaginal junction, part of the reproductive duct, was studied in domestic hens, specifically the special tubular structures known as the sperm host gland. The results were compared between two groups—non-embryonated and embryonated egg producers. Relevant samples were collected, processed to paraffin wax blocks, and sections cut and stained with H&E and PAS stains. Two types of glands were observed in the lamina propria and submucosa. The results from the sperm host glands in chicken’s oviduct suggested that it might have a functional role in oviductal sperm storage in and release of spermatozoa from the sperm host glands of native hens. Sperm storage structures in the form of tubules are observed in the wall of the uterovaginal junction. These tubules are lined by both ciliated and secretory cells and may play a role in the storage of sperm. These features showed better development in the group of egg-laying hens producing embryonated eggs in comparison to the ones producing non-embryonated eggs.     

Association between long-term aspirin use and periodontal attachment level in humans: a cross-sectional investigation

Background: Pharmaceutical inhibition of host response pathways may be an adjunctive or alternative strategy for treating periodontal diseases. In addition to inhibition of prostaglandin synthesis, aspirin is known to modify the action of cyclo‐oxygenase, changing its activity to a lipoxygenase and leading to formation of lipoxins which have a proresolving effect. This study evaluated the periodontal attachment level of subjects on long‐term low dose aspirin therapy. Methods: Oral hygiene index simplified, clinical attachment loss and bleeding index were recorded for 162 subjects who were on long‐term (>6 months) low dose (75 mg and 150 mg) aspirin therapy (study group) and 146 subjects not taking the drug (control group). Results: Mean clinical attachment loss was 2.38 ± 0.49 mm in the control group and 2.01 ± 0.69 mm in the study group. The difference was statistically significant at p < 0.001. Correlation analysis suggested that there was a negative correlation between clinical attachment loss and duration of aspirin intake but the clinical attachment loss was not significantly different in the two dosage groups. Conclusions: The results of this study suggest that low dose aspirin may reduce the risk of periodontal attachment loss. This hypothesis needs to be tested by larger sample sized prospective cohort studies.     

A histological study of the outer layer of rabbit fish (Siganus javus) eye

The rabbit fish is an economically valuable teleost species which lives in shallow coastal waters amongst aquatic plants. Two species of rabbit fish, Siganus sutore and Siganus javus, have been identified in the sea south of Iran. In this study, in order to investigate the histology of the outer layer of the S. javus eye, the eyes of 12 healthy specimens of S. javus were extracted and histologic sections were prepared. The sections were studied under a light microscope after staining with hematoxylin and eosin and Masson's trichrome stains. The outer layer was composed of the cornea cranially and the sclera caudally. The sclera contained an episclera zone and two cartilaginous segments with connective tissue correlation. The cornea included dermal components (stratified cuboidal epithelium, Bowman's membrane, and dermal stroma with occasional flattened cells); the scleral part consisted of two main layers (irregular fibers of connective tissue overlaying the second scleral stroma layer). The fibers of the scleral stroma were the only component present at the posterior part of the cornea. These results reveal that the eye of S. javus does not possess Descemet's membrane or endothelium in the cornea.     

Computer-aided dermoscopy for diagnosis of melanoma

Background

Recently, it has been observed that Video Display Terminals (VDTs) usage for long periods can cause some dermatological manifestations on the face. An analytical cross-sectional study was designed in order to determine this relationship.

Methods

In this study, 600 office workers were chosen randomly from an organization in Tehran (Iran). The subjects were then divided into two groups based on their exposure to VDTs. 306 workers were considered exposure negative (non VDT user) who worked less than 7 hours a week with VDTs. The remainders 294 were exposure-positive, who worked 7 hours or more with VDTs. The frequency of dermatologic manifestations was compared in these two groups.

Results

In the exposure-positive and exposure-negative groups, the frequency of these dermatologic manifestations were 27 and 5 respectively. After statistical analysis, a P.value of < 0.05 was obtained indicating a statistically significant difference between these two groups for dermatological manifestations.

Conclusion

According to our study, there is a relationship between dermatologic manifestations on the face and exposure to VDTs.