Skeletal muscle repair in a mouse model of nemaline myopathy

Nemaline myopathy (NM), the most common non-dystrophic congenital myopathy, is a variably severe neuromuscular disorder for which no effective treatment is available. Although a number of genes have been identified in which mutations can cause NM, the pathogenetic mechanisms leading to the phenotypes are poorly understood. To address this question, we examined gene expression patterns in an NM mouse model carrying the human Met9Arg mutation of alpha-tropomyosin slow (Tpm3). We assessed five different skeletal muscles from affected mice, which are representative of muscles with differing fiber-type compositions, different physiological specializations and variable degrees of pathology. Although these same muscles in non-affected mice showed marked variation in patterns of gene expression, with diaphragm being the most dissimilar, the presence of the mutant protein in nemaline muscles resulted in a more similar pattern of gene expression among the muscles. This result suggests a common process or mechanism operating in nemaline muscles independent of the variable degrees of pathology. Transcriptional and protein expression data indicate the presence of a repair process and possibly delayed maturation in nemaline muscles. Markers indicative of satellite cell number, activated satellite cells and immature fibers including M-Cadherin, MyoD, desmin, Pax7 and Myf6 were elevated by western-blot analysis or immunohistochemistry. Evidence suggesting elevated focal repair was observed in nemaline muscle in electron micrographs. This analysis reveals that NM is characterized by a novel repair feature operating in multiple different muscles.Despina Sanoudou, Mark A. Corbett, Mei Han, Majid Ghoddusi, Mai-Anh T. Nguyen, Nicole Vlahovich, Edna C. Hardeman, and Alan H. Begg

Root Canal Anatomy of Maxillary and Mandibular Teeth

It is a common knowledge that a comprehensive understanding of the complexity of the internal anatomy of teeth is imperative to ensure successful root canal treatment. The significance of canal anatomy has been emphasized by studies demonstrating that variations in canal geometry before cleaning, shaping, and obturation procedures had a greater effect on the outcome than the techniques themselves. In recent years, significant technological advances for imaging teeth, such as CBCT and micro-CT, respectively, have been introduced. Their noninvasive nature allows to perform in vivo anatomical studies using large populations to address the influence of several variables such as ethnicity, aging, gender, and others, on the root canal anatomy, as well as to evaluate, quantitatively and/or qualitatively, specific and fine anatomical features of a tooth group. The purpose of this chapter is to summarize the morphological aspects of the root canal anatomy published in the literature of all groups of teeth and illustrate with three-dimensional images acquired from micro-CT technology.info:eu-repo/semantics/publishedVersio

Histological Study of the Effects of Ibuprofen on Acute Apical Inflammation Following Root Canal Therapy in Cats

Postoperative pain following Root Canal Therapy (RCT) is the common problem for patients,"ndentist and dental staff. Regardless of cause it appears that postoperative pain and discomfort is related to"nperiapical inflammation. The purpose of this study was to investigate histologically the effect of"nIbuprofen on acute apical inflammation following RCT. on cat. Fifty-six cuspids teeth of 14 cats were"ndivided into three groups, 6 cats for experimental group, 6 cats for positive control group and 2 cats for"nnegative control group. In first group, to anesthesize the animals each cat received 10 mg/kg Ibuprofen"n36 hours before RCT and repeated every 24 hours. In second group RCT was performed in 24 cat teeth"nwithout any prescription. In negative control groups 2 cats, no RCT were done."nFollowing vital perfusion, in interval of 6, 12, 24 hours, samples were post fixed in 10% formalin and"nfive micron sections were prepared, and stained with H&E and studied under the Mann Whitney"nparameter test. Infilteration of inflamatory cells in 6 hours interval in experimental group was"nsignificantly less than two control groups. In 12 hours samples, however, inflammation in experimental"ngroup reduced, but it was not significant. In 24 hours samples there was no significant difference"nbetween experimental groups and controls. The result of this in-vivo study shows prescription of"nIbuprofen before root canal therapy can reduce inflammatory reaction

Histological evaluation of the effect of platelet-rich plasma on pulp regeneration in nonvital open apex teeth: An animal study

Aim: Platelet-rich plasma (PRP), which is a concentration of growth factors found in platelets, may be a suitable material for pulp regeneration. The aim of this animal study was a histological evaluation of PRP on pulp regeneration in nonvital teeth with immature apices. Materials and methods: A total of 40 premolar dogs' teeth were chosen for this study. After general anesthesia, the teeth were exposed, and subsequently, pulps were removed and the cavities were opened to the oral cavity. After 2 weeks, root canals were irrigated and disinfected with sodium hypochlorite with noninstrumentation technique, and triple antibiotic paste was placed inside the canals. Cavities were sealed with a temporary restoration. About 4 weeks later, canals were irrigated again and the teeth were randomly divided into three groups. Bleeding was evoked with overinstrumentation, then experimental materials for each group PRP, mineral trioxide aggregate (MTA), and parafilm respectively were placed over the bleeding, and orifices were sealed with MTA and glass ionomer. After 3 months, dogs were sacrificed and the teeth were separated from the jaws and sections prepared for histological evaluation. Results: Regeneration was shown in 44.7% of the samples. About 47.3% of the samples in the MTA group and 42.1% of the samples in the PRP group showed regeneration; however, no regeneration was observed in the parafilm group. Chi-square test showed no significant difference between groups I and II. The soft regenerative tissue included pulp-like tissue and vessels. Mineralized regenerative tissue included cementumlike, periodontal ligament-like, and bone-like tissues. No normal pulp and nerve tissue were observed. Conclusion: Both PRP and MTA may be ideal scaffolds to accelerate the regeneration process. Clinical significance: Pulp repair in immature permanent teeth with weak roots has a better outcome than replacement of the pulp with gutta-percha or biomaterials

An Apparent Outbreak of Cutaneous Papillomatosis in Merino Sheep in Patagonia, Argentina

A retrospective study was performed on skin samples from an outbreak of cutaneous papillomatosis in Merino sheep that occurred in 1995. The samples were processed for routine histology, electron microscopy and immunocytochemistry for papilloma viruses. Particles of approximately 55 nm diameter were found in some nuclei of the stratum granulosum cells, while immunocytochemistry gave positive staining of cell nuclei in this layer. This study confirms that papillomas associated with papillomaviruses occur in sheep in Patagonia