Vasile Rus

Role of nitro-oxidative stress in the pathogenesis of experimental rat periodontitis.

Background and aims Periodontitis is a common chronic adult condition that implicates oxidative damage to gingival tissue, periodontal ligament and alveolar bone. This study aimed at assessing the association between the nitro-oxidative stress and the periodontal tissues destructions in experimental rat periodontitis. Methods Periodontitis was induced in 15 male albino rats by repetitive lesions to the gingiva adjacent to the inferior incisors, performed daily, for 16 days. On D1, D3, D6, D8, and D16 the onset and evolution of periodontitis were monitored by clinical and histopathological examinations; blood was collected and serum nitro-oxidative stress was evaluated through total nitrites and nitrates, total oxidative status, total antioxidant capacity, and oxidative stress index. Results The results demonstrated that there was a graded and continuous increase in serum levels of total nitrites and nitrates, total oxidative status and oxidative stress index, which was consistent with the severity of periodontal destructions during periodontitis progression. However, total antioxidant capacity was not significantly influenced by the disease progression. Conclusions In experimental rat periodontitis, the systemic nitro-oxidative stress was associated with the severity of periodontal destructions assessed clinically and histopathologically. Therefore, systemic nitro-oxidative stress parameters might be used as diagnostic tools in periodontitis.

Titania versus Ceria Alumina/Zirconia Composites: Structural Aspects and Biological Tolerance

The aim of our study is to compare the structural and biological tolerance of novel Al2O3/3Y-TZP composites with ceria respectively titania addition (5 wt%). Scanning electron microscopy, X-ray diffraction, infrared spectroscopy and XPS results are reported for structural characteristics and surface modifications upon different fluoride treatments. The biocompatibility of the samples was evaluated using an animal model (rabbit). The explants were analyzed at a specific period (6 weeks).The sections of implanted bone area were subjected to histological evaluation. Upon correlating the structural properties and in vivo evaluation, we concluded that the addition of both TiO2 and CeO2 to Al2O3/3Y-TZP implies similar properties and satisfactory biological tolerance. With respect to the surface treatment, qualitative and quantitative results show that the alumina/zirconia with titania addition are more sensitive to fluoride treatment.

Microscopic Structure of the Epithelium Lining the Epiglottis in Wistar Rats

The aim of this study was to investigate the type of the epithelium present on the epiglottis surface, through histological examination. The epithelium lining the pharyngeal side of epiglottis is keratinized stratified squamous. The thickness of the keratin layer is different from one subject to another. Usually the keratin layer extends to the apex of the epiglottis, but in some of the animals taken into study, the keratin layer extends to the apical third of the laryngeal side of epiglottis. The epithelium lining the laryngeal side is different. In most of the epiglottises examined, the surface is lined by non-keratinized stratified squamous epithelium in the apical third. The rest of the laryngeal side of the epiglottis is lined by respiratory epithelium type. In one subject, the entire laryngeal surface is lined by a non-keratinized stratified squamous epithelium. Our study highlights that the pharyngeal side of epiglottis is lined by a keratinized stratified squamous epithelium, whereas on the laryngeal side, the epithelium in the apical third is non-keratinized stratified squamous and at the rest of the surface the epithelium is pseudostratified.

The Structure of Urethral Epithelium in Merinos Lambs

The aim of this study was to investigate by histological techniques the structure of urethral epithelium in lambs. In this study, we harvested several fragments (prostatic, membranous and cavernous) from urethra from 5 merino’s lambs of 3 months old. The first anatomical segment, the prostatic urethra, is lined by a urinary epithelium. The intermediary layer of this epithelium is formed of 5-6 rows of oval cells. The second segment of urethra has the same type of epithelium but the intermediary layer is formed of 6-7 rows of oval cells. In the last anatomical segment, the penile urethra, the epithelium is the same, but the intermediary layer has 3-4 rows of oval cells. In lambs, the urethra is lined by urinary epithelium. The urethral epithelium does not have the same thickness in all segments. The thinner epithelium it is in the cavernous urethra, the ticker is the membranous urethra.

Comparative immunohistochemical assessment of the effect of repetitive anesthesia with isoflurane and sevoflurane on rat liver

BACKGROUND AND OBJECTIVES Inhalation anesthetics are used in human, as well as veterinary medical practice. In the present study we investigated the effect of isoflurane and sevoflurane on rat hepatocytes. METHODS A total of 40 Wistar female rats were used in this study. Animals were divided in groups of 5 rats. Groups IM, SM served as control groups. Groups I1, I2, I3 were used to study isoflurane and S1, S2, S3 for sevoflurane study. They were anesthetized 3 times, for 2h long, at 2 days interval with a concentration of: 1.5% isoflurane (I1, I2, I3) and 2% sevoflurane (S1, S2, S3). The oxygen supply throughout the anesthesia was 1LO2/min. Groups IM, IS, I1, S1 were sacrificed immediately after the last anesthesia. Groups I2, S2 were sacrificed 6h after the last anesthesia, and groups I3, S3, 24h post-anesthesia. Liver samples were harvested to highlight caspase-3 in apoptotic hepatocytes. RESULTS Following isoflurane administration, there were less than 1% cells in apoptosis highlighted in rat livers from groups IM, I1 and I2. At 24h post-anesthesia (group I3), a small number of apoptotic hepatocytes was highlighted (around 3.23% cells in apoptosis), with a strictly periacinar disposition, randomly distributed in a small number of hepatic lobules. After sevoflurane administration, less than 1% apoptotic hepatocytes were identified at all control moments throughout the study. CONCLUSIONS The results suggest that the anesthetics do not present a considerable hepatotoxicity. The comparative assessment of the two anesthetics shows that sevoflurane is superior to isoflurane.

Oral Human Papillomavirus Infection in Children.

Oral human papillomavirus infection is rare in children, but the presence of a villous lesion with slow but continuous growth concerns parents, who need information and therapeutic solutions from the physician. All these aspects are discussed based on a case report of a 9-year-old child with an oral human papillomavirus infection.

Histological evidence concerning the osseointegration of titanium implants in the fractured rabbit femur

Stabilization of the broken bone is achieved using biocompatible materials. Since histology is still considered the gold standard technique for the assessment of bone formation around metallic implants, this report investigated the titanium implant integration in the accidentally broken bone in rabbits. The experimental protocol was reviewed and approved by the Ethical Committee of the Faculty of Medicine and Pharmacy Oradea, Romania. Holes were drilled in the diaphysis of the femur, and titanium implants were inserted in the created bone defect. In two subjects, fractures occurred on days two and three after the metallic alloy implantation. The other two rabbits presented no fractures following the surgical procedure. The rabbits were euthanized and the bones (with metallic implants) were harvested for histopathological investigation. Following decalcification, the bone samples were processed using the standard paraffin technique and stained by Goldner’s trichrome procedure. In subjects with a perfect immobilization of the titanium implants, the osseointegration occurred with minimal callus formation (i.e. primary cortical healing). In rabbits with bone fractures, the callus was more exuberant. A progressive replacement of the granulation tissue with hyaline cartilage and woven bone occurred soon after. The former aspects suggested an indirect metaplasia in the created callus. In all subjects, no inflammatory cells were identified in the created callus. The bone regeneration occurred either by primary cortical healing (in perfectly immobilized titanium implants) or by a process similar to the endochondral ossification (in poorly immobilized titanium implants following accidental post-implantation bones fracture).

MICROSCOPICAL ASPECTS CONCERNING THE PRESENCE AND DISTRIBUTION OF MITOCHONDRIA IN INTRALOBULAR AND INTERLOBULAR DUCTS FROM RAT PAROTID GLAND

Saliva secreted by acini from parotid gland is concentrated in the excretory ducts. This study aims to highlight certain microscopical aspects concerning the presence, density and disposition of mitochondria in intralobular and interlobular ducts from parotid parenchyma in rats. In the intralobular ducts’ segment lined by cuboidal cells, mitochondria are present throughout the whole cytoplasm, without a regular arrangement. In the area where cells are columnar, mitochondria become more numerous and most of them are disposed in the basal half and have a regular disposition (perpendicular to the basal pole). In the interlobular ducts, mitochondria are somehow less, but their disposition is similar to the one in the previous segment. In intralobular ducts with a thin wall, mitochondria have an irregular disposition and are present throughout the whole cytoplasm, while in striated and interlobular ducts, they have a regular disposition, perpendicularly on the basal pole of the cell and most of them are concentrated in the basal half of the cell.

STRUCTURAL PARTICULARITIES OF THE EPITHELIUM LINING THE LAMB EPIGLOTTIS

Epiglottis presents a central axis covered by mucosa. The aim of this study was highlighting the type of epithelium lining the lamb epiglottis. Thus, we histologically processed the epiglottis from 3 lambs. The epithelium lining the whole epiglottis surface is non-keratinized stratified squamous, with different thickness from one side to the other. Hence, on the pharyngeal side the epithelium is twice as thick as the one found on the laryngeal side.

Human papillomavirus infection in the oromaxillofacial area: Clinical anatomy and histological considerations

Clinical manifestations of human papillomavirus (HPV) infection in the head and neck can range from benign lesions, which are the most frequent, to malignant lesions. The prevalence of head and neck cancer is increasing, despite currently decreasing trends in known risk factors such as smoking and alcohol use. A new patient profile has appeared in recent practice: most frequently a middle‐aged male patient who does not smoke or drink alcohol, is sexually active (possibly having multiple partners), and presents with oral or cervicofacial lesions requiring diagnosis and treatment. Another risk factor that should be considered in these patients is HPV infection. The association of oral potentially malignant disorders (OPMD) with HPV is a challenge for the medical practitioner. The gold standard for diagnosis is histopathological examination, which can also yield evidence suggesting HPV infection. Determination of the viral genotype provides additional data for assessing the oncological risk of an HPV infection. Treatment of these patients is aimed at removing the lesions, in association or not with antiviral treatment and recurrence control. Clin. Anat. 28:1002–1007, 2015.