35 research outputs found
Pulpal Tissue in Bilateral Talon Cusps of Primary Central Incisors: Report of a Case
Talon cusp is a tooth anomaly that affects both the primary and the permanent dentitions. However, the occurrence of this anomalous cusp is rather infrequent in the primary dentition. Only 7 cases of bilateral talon cusps affecting the primary teeth have been reported in the dental literature. This is a case report of bilateral talon cusps on primary maxillary central incisors whose histologic evaluation revealed the existence of pulpal tissue in the anomalous cusps
Effects of Topical Ozone Application on Outcomes after Accelerated Corneal Collagen Cross-linking: An Experimental Study
Purpose: Ozone is a trioxygen molecule that spontaneously degrades into oxygen and oxygen free radicals. This study was designed to assess the effects of topical ozone application on outcomes after corneal collagen cross-linking (CXL).
Methods: Enucleated fresh cadaver yearling sheep eyes (n = 28) were divided into five groups: control (C, n = 6), sham (S, n = 6), ozone only (Z, n = 6), CXL only (X, n = 5), and Ozone + CXL (ZX, n = 5). In all groups, except C, the epithelial layer was removed. In group Z, 20 μg/mL liquid ozone was topically applied. In group X, CXL was performed in the accelerated pulse mode. In group ZX, both CXL and ozone were applied. Post-interventional oxygen levels were determined and corneal confocal microscopy and optical coherence tomography were performed. Corneas were evaluated using light and electron microscopy.
Results: Pre-interventional central corneal thickness (CCT) was highest in the control group and considerably similar in the remaining groups (P = 0.006). Pre- and post-interventional CCT were significantly different in the ozonated groups (Z and ZX) (P = 0.028; P = 0.043). Demarcation line depths were similar in groups Z, X, and ZX (P = 0.343). Increased stromal tissue reflectivity was observed in groups Z, X, and ZX. Oxygen levels were higher in the ozonated groups (Z and ZX) (P = 0.006), and caspase activity was higher in the CXL groups (X and ZX) (P = 0.028) as compared to the other groups. Group ZX showed tighter, more regular, and parallel fibrils.
Conclusion: Ozone increases corneal stromal oxygenation which can probably augment the effect of CXL. Future studies should investigate the safety and feasibility of ozone application during CXL
Comparison of collagen biomatrix and omentum effectiveness on peripheral nerve regeneration
Despite the presence of various nerve coaptation materials and techniques, achievement of the functional nerve regeneration is still inadequate. This study was aimed to compare the effectiveness of conduit composed of collagen biomatrix and omentum graft on peripheral nerve regeneration. Thirty-five male Wistar rats were divided into four groups. In the control group, the right sciatic nerve was skeletonized from the sciatic notch till the point of bifurcation. In the primary epineural repair group, the nerve was transected 1 cm proximal to the bifurcation with a sharp pair of micro scissors and then repaired with four epineural sutures. In the collagen biomatrix group, the epineural repaired nerve was wrapped with collagen biomatrix. In the collagen group, the epineural repaired nerve was wrapped with the nonpediculated omentum. Assessment of the nerve regeneration was based on functional (Walking Track Analysis, Electrophysiological Measurements), histological, and morphometric criteria. Light and electron microscopic examinations showed that collagen-biomatrix-wrapped specimens have the best regeneration. The electrophysiological study confirmed the recovery of electrical activity in the regenerated axons
Synthesis of microbial elastomers based on soybean oily acids. Biocompatibility studies
Biocompatibility studies of the autoxidized and unoxidized unsaturated medium-long chain length (m-lcl) co-poly-3-hydroxyalkanoates (m-lclPHAs) derived from soya oily acids have been reported. Pseudomonas oleovorans was grown on a series of mixtures of octanoic acid (OA) and soya oily acids (Sy) with weight ratios of 20:80, 28:72 and 50:50 in order to obtain unsaturated m-lcl copolyesters coded PHO-Sy-2080, PHO-Sy-2872 and PHO-Sy-5050, respectively. The PHA films were obtained by solvent cast from CHCl3. They were all originally sticky and waxy except PHO-Sy-5050. Autoxidation of the unsaturated copolyester films was carried out on exposure to air at room temperature in order to obtain crosslinked polymers. They became a highly flexible elastomer after being autoxidized (about 40 days of autoxidation). The in vivo tissue reactions of the autoxidized PHAs were evaluated by subcutaneous implantation in rats. The rats appeared to be healthy throughout the implantation period. No symptom such as necrosis, abscess or tumorigenesis was observed in the vicinity of the implants. Retrieved materials varied in their physical appearance after 6 weeks of implantation. In vivo biocompatibility studies of the medical applications indicated that the microbial copolyesters obtained were all biocompatible and especially the PHOSy series of copolyesters had the highest biocompatibility among them. © 2009 IOP Publishing Ltd
Effects of topotecan treatment on nasal, buccal, and lingual mucosa in the rabbit: light and transmission electron microscopic evaluation
WOS: 000243000300015PubMed: 17063354Anticancer agents may cause side effects and some of which may be dose dependant. It is important for clinicians to see the effects on tissues histopathologically. The aim of this study was to investigate the effects of topotecan (hycamtin((R))), a topoisomerase I inhibiting anticancer agent, on nasal, buccal, and lingual mucosa of rabbits. The study was carried out in two groups each consisting of 20 rabbits. Rabbits in group I received i.v. topotecan (0.5 mg/kg once daily) for 3 days. Rabbits in group II received i.v. topotecan (0.25 mg/kg once daily) for 3 days. In group I and II, biopsies from the nasal, buccal, and lingual mucosa were taken on the fourth (1 day after the 3-day topotecan treatment) and 15th day (12 days after the 3-day topotecan treatment). Light and transmission electron microscopic (TEM) observations have shown that nasal mucosa was not affected by topotecan administration. Topotecan treatment resulted in the formation of some ulcerative lesions in the lingual mucosa especially on the lower surface of the tongue. On the dorsal surface, the epithelium showed highly edematous and degenerating cells and separations in the stratum granulosum. In the buccal mucosa, effects were similar. In lingual and buccal mucosa, healing was observed on the 15th day. The oral (lingual and buccal) mucosal side effects of topotecan were observed as reversible and not dose dependent. It was concluded that these side effects are not severe, and topotecan may be used safely in cancer treatment
Tavuk Embriyosu Koryoallantoik Membranında Görülen Anjiyogenez Sürecinde C-Tipi Natriüretik Peptid-3 ve Natriüretik Peptid Reseptör-B mRNA İfadelerinin Analizi: Tanımlayıcı Bir Çalışma
Tavuk koryoallantoik membran (CAM) modeli, anjiyogenez çalışmalarında gelişimsel süreçleri takip etmek için yaygın olarak kullanılan bir modeldir. Bu çalışmada, CAM kullanılarak, embriyonik gelişimin 7. ve 20. günleri (E7 ve E20) arasında görülen anjiyogenez süreci ışık ve transmisyon elektron mikroskop analizleri ile takip edilmiştir. Ayrıca, aynı günlerde alınan CAM örnekleri kullanılarak, anjiyogenez meka nizmalarında görevli [Vasküler Endotelyal Büyüme Faktörü (VEGF)-A ve Fibroblast Büyüme Faktörü (FGF)-2] ve reseptörlerinin [Vasküler Endotelyal Büyüme Faktörü Reseptörü (VEGFR)-2 ve Fibroblast Büyüme Faktörü (FGFR)-2] yanı sıra, insan C-tipi natriüretik peptid (CNP) homoloğu olan tavuk CNP-3 ve reseptörü natriüretik peptid reseptörü (NPR)-B'nin mRNA ifade düzeylerinin zamana bağımlı değişimi analiz edilmiştir. Işık mikroskobu ve elektron mikroskobu analizleri, endotel tüp benzeri vasküler yapıları yoğun olarak E7-E8 günlerinde ve koryonik mezenşim içinde bulunduğunu göstermiştir. E9-E20 günler sürecinde ise mezenşim içinde yer alan vasküler yapıların progresif gelişimi, stabilizasyonu ve kompleks dallanması gözlenmiştir. Bu vasküler gelişim sürecinde, VEGF-A ve FGF-2 mRNA ifadesi, CAM gelişiminin erken aşamalarında E7 ile E9 arasında ve E8'de pik yapacak şekilde gözlenmiştir. Bu moleküller, CAM gelişiminin geç döneminde, E16 civarında ikinci bir pik göstermiştir. CNP-3 mRNA ifadesi E16 ile E20 arasında VEGF-A ve FGF-2 mRNA ifadeleri ile eş zamanlı olarak tespit edilmiştir. VEGFR-2 mRNA ifadesi E7-E12 arasında gözlenirken, FGFR-2 mRNA ifadesi ilk pikini E7-E9 arasında ve ikinci pikini E16-20 arasında göstermiştir. NPR-B mRNA ifadesi ise en yüksek seviyesi E16’da olmak üzere E7-E20 arasında gözlenmiştir. Sonuç olarak elde edilen veriler, CNP-3'ün özellikle CAM gelişiminin geç döneminde (E16-E20 günleri sürecinde), NPR-B reseptörü aracılığıyla, ileri vasküler organizasyonda rol oynayabileceğini ortaya koymuştur.The chick chorioallantoic membrane (CAM) is a widely used model to follow the developmental processes in angiogenesis studies. This study aims to describe the putative involvement of CNP-3, the chick homolog of human CNP, and its receptor natriuretic peptide receptor (NPR)-B besides known angiogenic factors and their receptors, vascular endothelial growth factor (VEGF)-A/ vascular endothelial growth factor receptor (VEGFR)-2 and fibroblast growth factor (FGF)-2/fibroblast growth factor receptor (FGFR)-2, in angiogenesis of the CAM. CAM samples between developmental days E7 and E20 were collected for light microscopic and transmission electron microscopic analyses. Expression of CNP-3/NPR-B, VEGF-A/VEGR-2, FGF-2/FGFR-2 mRNA in these CAM samples were also studied between E7 and E20. Light microscopy and electron microscopy analyzes showed that, vascular organization was mostly within the chorionic mesenchyme as endothelial tube-like structures on E7-E8 days. On E9 and later, advanced blood vessels were observed within the mesenchyme. VEGF-A and FGF-2 expression were observed in the early stages of CAM development (E7-E9) with a peak at E8. These molecules showed a second peak at around E16. Co- expression of VEGF-A, FGF-2 and CNP-3 were seen at E16-E20. VEGFR-2 expression was observed between E7- E12, whereas expression of FGFR-2 showed its first peak between E7-E9 and its second peak between E16-20. NPR-B expression, on the other hand, was observed between E7-E20 with its highest level at E16. In conclusion, the results revealed that CNP-3 may have a role in vascular organization via its NPR-B receptor in the later stages, i.e., E16-E20, of CAM development
Congenital Microvillus Inclusion Disease In The Differential Diagnosis Of Intractable Metabolic Acidosis
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The Time Course Changes In Expression Of Aquaporin 4 And Aquaporin 1 Following Global Cerebral Ischemic Edema In Rat
Background: The aim of this global cerebral ischemia study was to study the changes in expression levels of aquaporin 4 (AQP4) and AQP1 over time. Methods: Sprague-Dawley type male rats were divided into six groups. Sham group and ischemia/reperfusion were performed on five other groups using the four-vessel occlusion model. Reperfusion was done 30 min after the occlusion, and each group was tested at 1, 6, 12, 24, and 48 h for brain wet-dry weight ratio and AQP4 and AQP1 expression levels using immunohistochemistry. To prove ischemia development exists in both hippocampal neurons and epithelia of choroid plexus, hematoxylin, and eosin and neuronal marker (NeuN) immune-staining have been applied to the sham experimental group at 48 h. AQP4 expression levels are also measured with western blotting. Results: After ischemia/reperfusion it is observed that the decrease in brain water content between 12 and 24 h was statistically significant (P < 0.01). In parallel and based on immunohistochemical staining, AQP4 expression levels did not exhibit any statistically significant change. AQP4 levels did not show any statistically significant change in western blotting. AQP1 expression in choroid plexus epithelial cells decreased at the 12 and 24 h but increased in 48 h (P < 0.05). Conclusions: Lack of change in AQP4 expression levels is thought as its dual role in formation and elimination of ischemic brain edema. Decrease in AQP1 expression levels in 24 h can be explained with necrosis in choroid plexus after ischemia and the increase in 48 h mark can be related to recovery in choroid plexus.PubMe
The effect of subcutaneously injected nicotine on achilles tendon healing in rabbits
The objective of this study was to evaluate the effect of subcutaneously injected nicotine on transversely transected and sutured achilles tendon healing in an experimental rabbit model. Adult New Zealand rabbits (n=22) weighting 3,000-3,500 g were used in this experimental study. Rabbits were randomly divided into two groups. Achilles tendon was transversely incised and repaired in all animals. In the experiment group subcutaneous injection of Nicotine tartrate 3 mg/kg/day was done. In the control group Serum physiologic injection was done at the same dosage. The injections were made three times a day in equal dosages. Nicotine and SF injections were made until the end of the 8-week, and then all animals were euthanized. Both light microscopic and electron microscopic evaluations were made on 14 animals. In N group light microscopic evaluation showed a visible gap in repair site. The total tendon score represented in N group was less than in SF group. The statistical analysis of the groups was significantly different for total tendon scores (P=0.002). Beside this electron microscopic examination showed inactive and degenerated fibroblasts and irregular collagen fibrils around them as well as collagen synthesis interruption in N group. Biomechanical evaluation was made on eight animals. The average tensile strength values in Group N (139.47 +/- 44.55 N) were significantly lower than those in Group SF (265.9 +/- 39.01 N) (z=2.309, P=0.029). Nicotine is the major chemical component common to all cigarettes and previously has been shown to affect wound and fracture healing adversely. The results of this study show that nicotine impairs achilles tendon healing after a surgical repair