Evaluation of Oral Mucosal Lesions in Iranian Smokers and Non-smokers.

BACKGROUND: Tobacco smoking statistics are alarming and the oral mucosa is the first human part of the body that is exposed to the toxic substances of smoking. AIMS: Considering the high prevalence rate of tobacco-associated problems in the oral cavity and few studies on the Iranian population regarding the effects of smoking on the oral cavity, this study aimed to evaluate the relationship between smoking and oral lesions in the Iranian population. MATERIALS AND METHODS: Observational study. In this observational study, the oral cavities of 200 participants (smokers = 100 and non-smokers = 100) were examined by a trained dental student under the supervision of an oral and maxillofacial medicine expert, and the presence of coated tongue, leukoedema, leukoplakia, smoker's palate, smoker's melanosis, erythroplakia, frictional hyperkeratosis, acute pseudomembranous candidiasis, and erythematous candidiasis were recorded. Xerostomia was evaluated based on participants' self-reporting through a questionnaire. All data were analyzed using T-test, Chi-square test, odd ratio, 95% confidence interval, Fisher's exact test, and Spearman's rank correlation coefficient. RESULTS: The results of this study showed smoking is significantly associated with an increased risk of coated tongue (OR: 1.80, 95% CI: 1.32-3.54, P = 0.005), smoker's melanosis (OR: 6.176, 95% CI: 3.28-11.62, P = 0.00002), and frictional hyperkeratosis (OR: 1.33, 95% CI: 0.68-2.60, P = 0.005). However, no significant association was observed between smoking and leukoedema (OR: 1, 95% CI: 0.51-1.94, P = 1). None of the participants presented smoker's palate, erythroplakia, and candidiasis. CONCLUSIONS: This study's results showed that smokers exhibited a greater chance of developing oral lesions compared to non-smokers.

The role of stem cell therapy in regeneration of dentine-pulp complex: a systematic review.

Infection of the dental pulp will result in inflammation and eventually tissue necrosis which is treated conventionally by pulpectomy and root canal treatment. Advances in regenerative medicine and tissue engineering along with the introduction of new sources of stem cells have led to the possibility of pulp tissue regeneration. This systematic review analyzes animal studies published since 2010 to determine the ability of stem cell therapy to regenerate the dentine-pulp complex (DPC) and the success of clinical protocols. In vitro and human clinical studies are excluded and only the experimental studies on animal models were included. Dental pulp stem cells constitute the most commonly used cell type. The majority of stem cells are incorporated into various types of scaffold and implanted into root canals. Some of the studies combine growth factors with stem cells in an attempt to improve the outcome. Studies of ectopic transplantation using small animal models are simple and non-systematic evaluation techniques. Stem cell concentrations have not been so far reported; therefore, the translational value of such animal studies remains questionable. Though all types of stem cells appear capable of regenerating a dentine-pulp complex, still several factors have been considered in selecting the cell type. Co-administrative factors are essential for inducing the systemic migration of stem cells, and their vascularization and differentiation into odontoblast-like cells. Scaffolds provide a biodegradable structure able to control the release of growth factors. To identify problems and reduce costs, novel strategies should be initially tested in subcutaneous or renal capsule implantation followed by root canal models to confirm results.

Co-relation of estrous cycle phases with uterine bacterial and fungal flora in non-pregnant female laboratory rabbits.

This study was designed to investigate the relationship between the estrous cycle phases with uterine bacterial and fungal flora in non-pregnant female rabbits. Thirty laboratory mature multiparous rabbits were used for this purpose. Samples from uterine lavage for culture of bacteria and fungi were collected at different stages of estrous cycle (based on vaginal cytology), and histopathological observations were evaluated based on the scoring system used for defining the infection of the uterus. Various types of bacteria and fungi were isolated from rabbits at all stages of estrous cycle. The widest variety of bacteria and fungi was isolated at Di-estrous stage and the lowest variety was detected at estrous stage. Klebsiella oxytoca as well as yeast have been isolated at all stages of estrous cycle. This study showed that infection with K. oxytoca and yeast had no relationship with different stages of estrous cycle but other bacteria and fungus were associated with one or more stages of the estrous cycle in rabbits.

Burn wound healing: present concepts, treatment strategies and future directions.

Burns are the most extensive forms of soft tissue injuries occasionally resulting in extensive and deep wounds and death. Burns can lead to severe mental and emotional distress, because of excessive scarring and skin contractures. Treatment of burns has always been a difficult medical problem and many different methods have been used to treat such injuries, locally. Biofilms are a collection of microorganisms that delay wound healing. One of the new methods of prevention and treatment of burn wound infections is application of antimicrobials, which act on biofilms and prevent the wound infection. Biofilm initiates a persistent, low-grade, inflammatory response, impairing both the epithelialisation and granulation tissue formation. Skin grafts have been shown to dramatically reduce deaths from infection. However, grafting has considerable limitations. Such injuries are long-lasting and many patients suffer from chronic pain for a long time. Tissue engineering is a new approach in reducing the limitations of conventional treatments and producing a supply of immunologically tolerant artificial tissue, leading to a permanent solution for damaged tissues; such criteria make it a cost-effective and reliable treatment modality. To overcome the present limitations of burn wound healing, knowledge about the latest findings regarding healing mechanisms is important. Here the authors discuss the most important events regarding burn wound healing and review the latest treatment strategies that have been used for burn wounds from in vitro to clinical levels. Finally, we discuss the role of tissue engineering and regenerative medicine in the future of burn wound healing, modelling and remodelling.

Finasteride is effective for the treatment of central serous chorioretinopathy.

PurposeTo evaluate the safety and efficacy of finasteride treatment in patients with central serous chorioretinopathy (CSC).MethodsRetrospective review of 29 eyes of 23 patients who were treated with finasteride for CSC. Previous medical and ocular history, steroid use, length of finasteride treatment, additional treatments for CSC, visual acuity (VA), central macular thickness (CMT), and presence of subretinal fluid (SRF) throughout the follow-up period, and the occurrence of any complications were recorded.ResultsInitial VA was 0.29±0.31 logMAR, and a trend towards improved VA was noted after 3 months (0.25±0.36 logMAR; P=0.07). VA was significantly improved at the final follow-up (0.23±0.27 logMAR; P=0.024). Initial CMT was 354±160 µm, and was significantly reduced after 1 month of treatment (284±77 µm; P=0.002) and this was maintained to the end of follow-up (247±85 µm; P=0.001). A significant reduction in SRF presence was found at all time points, with an overall 75.9% rate of complete resolution. Following discontinuation, SRF recurrence was noted in 37.5% of cases. No adverse events were recorded.ConclusionsFinasteride is a safe and effective treatment for CSC. It may be a possible new option for the initial management of patient with CSC, and a suggested treatment approach is presented.

Collagen implants in experimental tendon injury in rabbits: a clinical, ultra-structural and biomechanical investigation.

This study investigated the effects of hybridized micro and nano structured collagen implants on tendon healing in an experimental tendon injury in rabbits. Fifty mature male New Zealand white rabbits were randomly divided into two groups of treated and control. Two cm of the left Achilles tendon were discarded. In the treated group, a 3-dimensional (3D) collagen implant was engineered and implanted in the defect area. No implant was used in the control group. At day 120 after injury, the Achilles tendon of the animals were ultrasonographically (days 0-120 after injury) and radiographically (day 120 after injury) examined, and the animals were euthanized. The tendons were dissected and used for gross pathological, histopathological, ultra-structural and biomechanical investigations. Application of the collagen implant significantly increased the diameter of the newly regenerated tissue in the defect area compared to the control tendons. Treatment also significantly increased the echogenicity and homogeneity of the injured area, the diameter of the collagen fibrils and fibers, maturity of the tenoblasts, number of tenocytes, collagen density, alignment, ultimate and yield load, stiffness, stress and modulus of elasticity. The collagen implants were almost totally absorbed 120 days after surgery. No inflammatory reaction or tissue degeneration or necrosis was evident in the treated tendons compared to the control ones. 3D collagen implants produced a newly regenerated tendinous tissue at the defect area that was morphologically and biomechanically superior to the control group. This collagen implant was biocompatible and biodegradable with high bio-safety in rabbits.

Recombinant fibroblast growth protein enhances healing ability of experimentally induced tendon injury in vivo.

This study was designed to investigate the effects of recombinant human basic fibroblast growth factor (bFGF) on a complete superficial digital flexor tendon (SDFT) rupture after surgical repair in rabbits. Eighty mature New Zealand White rabbits of both sexes were randomly divided into two equal groups: Treated and Control. Each group was subdivided into two 28- and 84-day post-injury subgroups. After tenotomy and surgical repair, the animals were immobilized for 14 days. In the treated group, bFGF was directly applied subcutaneously over the lesion on days 3, 7 and 10 after injury. The control animals received normal saline injection of the same viscosity and volume and at the same intervals. Ultrasonographical observations were conducted at weekly intervals. The animals were euthanized at 28 and 84 days after injury. The tendons were evaluated at macroscopic, histopathologic and ultrastructural levels and were assessed for biomechanical and percentage dry weight parameters. Compared to injured control animals, treated animals showed a decrease in the diameter of the injured tendon and peritendinous adhesion as well as increased tenoblast proliferation, collagen production and ultimate strength of the injured tendons (p < 0.005). At 84 days after injury, treatment resulted in enhanced maturation of the cellular and collagen elements and improved tissue alignment and density. These improvements resulted in increased biomechanical performance of the injured tendons compared to controls (p = 0.001). bFGF showed promising curative effects on restoration of the biomechanical and morphological properties of the ruptured SDFT in rabbits and may be applicable in clinical studies.

A long-term in vivo investigation on the effects of xenogenous based, electrospun, collagen implants on the healing of experimentally-induced large tendon defects.

AIM: This study was designed to investigate the effect of novel 3-dimensional (3-D) collagen implants on the healing of large, experimentally-induced, tendon-defects in rabbits. METHODS: Forty mature male white New Zealand rabbits were divided randomly into treated and control groups. Two cm of the left Achilles tendon was excised and the gap was spanned by Kessler suture. In the treated group, a novel 3-D collagen implant was inserted between the cut ends of the tendon. No implant was used in the control group. During the course of the experiment the bioelectrical characteristics of the healing and normal tendons of both groups were investigated weekly. At 120 days post injury (DPI), the tendons were dissected and inspected for gross pathology, examined by transmission and scanning electron microscopy, and their biomechanical properties, percentage dry matter and hydroxyproline concentration assessed. RESULTS: The collagen implant significantly improved the bioelectrical characteristics, gross appearance and tissue alignment of the healed, treated tendons, compared to the healed, control scars. It also significantly increased fibrillogenesis, diameter and density of the collagen fibrils, dry matter content, hydroxyproline concentration, maximum load, stiffness, stress and modulus of elasticity of the treated tendons, as compared to the control tendons. Treatment also significantly decreased peri-tendinous adhesions, and improved the hierarchical organization of the tendon from the collagen fibril to fibre-bundle level. 3-D xenogeneic-based collagen implants induced newly regenerated tissue that was ultrastructurally and biomechanically superior to tissue that was regenerated by natural unassisted healing. CONCLUSION: This type of bioimplant was biocompatible, biodegradable and appeared suitable for clinical use.

Modulation of cutaneous wound healing by silymarin in rats.

OBJECTIVE: To investigate the effect of topical application of silymarin on full-thickness cutaneous wounds in rats. METHOD: A full-thickness cutaneous defect (2×2cm) was induced on the back of 85 male and female Wister rats. The animals were randomly divided into four groups (n=20 in each group), treated with 1ml basal cream (placebo group), low-dose (6mg/ml/rat) and high-dose (12mg/ml/rat) silymarin, and untreated (control). Five rats remained uninjured to serve as comparisons for biomechanical analysis. Wounds were evaluated 10, 20 and 30 days after injury, through histopathologic, biochemical and biomechanical analyses. RESULTS: There was a significant (p < 0.05) increase observed in the amount of glycosaminoglycans and collagen present on days 10, 20 and 30 for both low-dose and high-dose silymarin groups. Low-dose silymarin reduced the number of lymphocytes and enhanced the number of fibrocytes at the earlier stages of wound healing; however, high-dose silymarin reduced both lymphocytes and macrophages, and increased number of fibrocytes at the later stages of wound healing. Silymarin significantly improved alignment of the healing tissue, enhanced maturity of the collagen fibres and fibroblasts (p < 0,05), and increased the ultimate tensile strength and stress of the healing tissue. CONCLUSION: The results suggest that topical application of silymarin improved the morphological, biochemical and biomechanical properties of experimentally-induced wound defects in rats. DECLARATION OF INTEREST: There were no external sources of funding for this study. The authors have no conflicts of interest to declare.

A long term study on the role of exogenous human recombinant basic fibroblast growth factor on the superficial digital flexor tendon healing in rabbits.

BACKGROUND: This study was designed to investigate the effects of basic fibroblast growth factor on the remodeling phase of the tenotomized superficial digital flexor tendon in rabbits. METHODS: Forty white New Zealand mature male rabbits were divided randomly into two equal groups of treated and control. After tenotomy and surgical repair, using modified Kessler technique and running pattern, the injured legs were casted for 14 days. Human recombinant basic fibroblast growth factor (bFGF) was injected subcutaneously over the lesion on days 3, 7 and 10 post injuries. The control animals received normal saline injection similarly. The weight of the animals, tendon diameter, radiographic and ultrasonographic evaluations was conducted at weekly intervals. The animals were euthanized 84 days post-injury and the tendons were evaluated at macroscopic, histopathologic and ultrastructural level and were also assessed for biomechanical and percentage dry weight parameters. RESULTS: Treatment significantly reduced the diameter and increased the echogenicity and dry weight content of the injured tendons. Treatment also significantly enhanced the maturation of the tenoblasts, fibrillogenesis, the collagen fibrils' diameter, fibrillar density, stiffness, and ultimate and yield strength. CONCLUSIONS: Subcutaneous administration of human recombinant bFGF is effective in restoring the morphological and biomechanical properties of the injured SDFT in rabbits.

Eimeria species in wild rabbits (Oryctolagus cuniculus) in Fars province, Iran.

This investigation was accomplished during February to November 2008. A total of 71 wild rabbits (Oryctolagus cuniculus) of about 5 to 12 months age were collected alive from different parts of Fars province, south of Iran. Faecal sampling was carried out directly from recti and the oocysts were isolated using sedimentation and floatation techniques and the sporulated oocyst were identified based on morphological and biological characteristics. All the rabbits were apparently healthy and showed no clinical symptoms. Twenty two rabbits (31.0%) were positive for infection with Eimeria and six species including Eimeria perforans (18.3%), Eimeria magna (16.9%), Eimeria media (14.1), Eimeria irresidua (11.2%), Eimeria flavescens (4.2%), and Eimeria coecicola (2.8%) were identified. Eighty six percent of the infected rabbits showed mixed infections with two or three Eimeria species. Lack of clinical signs could be due to the agro ecological and environmental conditions of rabbit habitats specifically dry and hot climatic features in recent years. In addition, immunity induced by long term exposure to low doses of oocysts shedded by the carrier animals probably have pivotal role in impairing parasitic developmental cycles and preventing acute coccidiosis.

A comparative study of neurogenesis in the retinal ciliary marginal zone of homeothermic vertebrates.

The retina of many fish and amphibians grows throughout life, roughly matching the overall growth of the animal. The new retinal cells are continually added at the anterior margin of the retina, in a circumferential zone of cells, known as the ciliary marginal zone, or CMZ. Recently, Fischer and Reh [Dev. Biol. 220 (2000) 197] have found that new neurons are added to the retina of the chicken via proliferation and subsequent differentiation of neurons and glia at the retinal margin in a zone highly reminiscent of the CMZ of lower vertebrates. In addition, other groups have reported that putative retinal stem cells could be isolated from the ciliary margin of the adult mouse. In light of these findings, we have re-investigated the eyes of three additional species to determine whether other homeothermic vertebrates also possess CMZ cells and whether we could detect evidence for addition of neurons at the retinal margin in mature animals. We examined one additional avian species, the quail, one marsupial, the opposum, and one mammal, the mouse. We find that the CMZ cells have been gradually diminished during vertebrate evolution. The quail has a reduced CMZ as compared to the chicken, while the opposum has only a few cells likely related to the CMZ and we failed to find evidence of CMZ cells at the margin of the mouse retina.

Location of the sulphonylurea receptor at the cytoplasmic face of the beta-cell membrane.

1. In insulin-secreting cells the location of the sulphonylurea receptor was examined by use of a sulphonylurea derivative representing the glibenclamide molecule devoid of its cyclohexy moiety (compound III) and a benzenesulphonic acid derivative representing the glibenclamide molecule devoid of its cyclohexylurea moiety (compound IV). At pH 7.4 compound IV is only present in charged form. 2. Lipid solubility declined in the order tolbutamide > compound III > compound IV. 3. The dissociation constant (KD) for binding of compound IV to the sulphonylurea receptor in HIT-cells (pancreatic beta-cell line) was similar to the KD value for tolbutamide and fourfold higher than the KD value for compound III. 4. In mouse pancreatic beta-cells, drug concentrations inhibiting adenosine 5'-triphosphate-sensitive K+ channels (KATP-channels) half-maximally (EC50) were determined by use of the patch-clamp technique. When the drugs were applied to the extracellular side of outside-out or the intracellular side of inside-out membrane patches, the ratio of extracellular to intracellular EC50 values was 281 for compound IV, 25.5 for compound III and 1.2 for tolbutamide. 5. In mouse pancreatic beta-cells, measurement of KATP-channel activity in cell-attached patches and recording of insulin release displayed much higher EC50 values for compound IV than inside-out patch experiments. A corresponding, but less pronounced difference in EC50 values was observed for compound III, whereas the EC50 values for tolbutamide did not differ significantly. 6. It is concluded that the sulphonylurea receptor is located at the cytoplasmic face of the beta-cell plasma membrane. Receptor activation is induced by the anionic forms of sulphonylureas and their analogues.