فصلنامه پاتوبیولوژی مقایسه ای
سال بیستم شماره 79 (بهار 1402)

This study was conducted with the aim of investigating the effectiveness of titanium dioxide nanocomposite scaffolds for the reconstruction of femur defects in rabbits. To investigate the effect of nanocomposites on the healing processes of broken bone (bone defect). 18 New Zealand adult male white rabbits weighing 3 kg were studied. A cylindrical defect with a diameter of 6 x 5 mm was created in the femur of rabbits. The animals were divided into three experimental groups. The experimental groups after the defect were created included control, control (hydroxyapatite) and treatment (titanium dioxide). On the 15th and 45th days after surgery, the animals were killed and a sample was taken from the bone defect site and placed in 10% buffered formalin. 5 μm sections were evaluated after general and trichrome staining. Improvement of inflammation on day 15 and formation of new bone on day 45 in the nanocomposite group was the best in terms of ossification repair unit and reduction of inflammation. Nanocomposite had a significant recovery function in bone regeneration of defective areas.

Recently, nidoviruses have been described as a possible cause of severe respiratory diseases in reptiles and especially pythons from different parts of the world. The aim of this study is to isolate the pathogenic agent along with the precise determination of its characteristics and to examine the histopathological findings in a female iguana. During the iguana post-mortem examination, pyogranulomatous and fibronecrotic lesions were observed in various organs other than the respiratory system, and the results of the reverse transcription polymerase chain reaction were also positive. Therefore, the relationship between the observation of these extensive lesions and the Necropsy findings obtained from Previous cases of serpanovirus infection and the amount and type of changes in the genome of the serpentovirus identified with the previous serpentovirus were investigated. Cell culture inoculation and then RT-PCR was used to collect and obtain the virus isolate. Next, immunohistochemistry was performed. Staining for the nucleoprotein of the serpentine virus showed that this virus infects not only a wide range of epithelia (respiratory and gastrointestinal epithelium, hepatocytes, urinary tubules, pancreatic ducts, etc.), but also contaminates the intravascular monocytes, intralesional macrophages, and endothelial cells too. With next-generation sequencing, the complete genome for this new serpentine virus species was obtained.The analysis of the viral genome recovered from this respiratory and systemic disease associated with serpentine virus infection did not show a sequence correlation with the phenotype of other strains. The results showed that this serpentine virus has a wide cell and tissue tropism, and the course of infection by it can be different, and as a result of the systemic spread of the virus in the body, it causes lesions in a wide range of different body systems.

Special features of nanoparticles such as high surface to volume ratio, homogeneous particle size, high stability and ease of production have led to their widespread use in various fields of pharmacy, dentistry, medicine, biology and materials engineering. In fact, the existence of many pathogenic bacteria that have created many risks in various industries, including medical equipment, dentistry, drinking water treatment and sewage treatment, is another reason for using nanoparticles to protect human health. Meanwhile, the green synthesis of nanoparticles by different strains of cyanobacteria has led to the production of environmentally friendly nanoparticles with various unique biological, physical and chemical properties. Cyanobacteria also have a variety of bioactive compounds such as pigments and enzymes that can act as regenerating and stabilizing agents in the process of producing nanoparticles. In addition, with their unique biochemical compositions that include several bioactive compounds with proven pharmacological activities, they also have potential antibacterial, antifungal, anti-algal, anti-cancer and photocatalytic properties. These properties have caused cyanobacteria to be used not only as useful natural resources, but also to be effective in the prevention and treatment of many diseases. Although many researches have been conducted in the field of biological synthesis using various microorganisms, fewer studies have focused on the use of cyanobacteria in the synthesis of nanoparticles. This article comprehensively examines the characteristics and commercial applications of nanoparticles synthesized by cyanobacteria in different fields, as well as the strategies of toxicity of nanoparticles against living cells.

The purpose of this study was to evaluate the type, severity and extent of tissue lesions induced by secondary infection with avian influenza virus following inoculation by ORT in SPF chickens. Sixty, one-day-old SPF chicks were provided and divided randomly into three groups. At the age of 21 days, the chicks in the first group were inoculated only with ORT and second group inoculated first with ORT and three days later with H9N2 virus. Each bird in third group was received only with PBS as control. Tissue samples were taken from trachea, lungs, liver, kidneys, bursa of fabricius, thymus, spleen and cecal tonsils for histopathological studies and after preparation and tissue sections were stained by Hematoxylin and Eosin (H&E) method. In chickens of the first group, ORT bacteria in addition to cause tissue lesions in organs of the respiratory system (loss of cilia with infiltration of mononuclear cells under the mucosa in the trachea, hyperemia and pneumonia in the lung), liver (congestion of sinusoids and central veins) and the kidneys (Hemorrhage and necrosis of urinary tubes) in  immune system organs also cause tissue lesions such as lymphocyte depletion in the bursa of fabricius, congestion and heterophil infiltration in thymus and increase in the of lymphoid follicles in the spleen and cecal tonsils. The histopathological lesions in chickens of the second group was more severe and longer than that of the first group. Tissue changes were not observed in control group. The results of this study showed that in chickens inoculated by ORT and under secondary infection with avian influenza virus cause exacerbate and lunge histopathological lesions induced by ORT.

Burns trigger intricate inflammatory processes and the generation of free radicals. The anti-inflammatory, antioxidant, and antibacterial characteristics of the Artemisia annua plant have a significant potential for enhancing the healing process for wounds. This study examines the impact of an Artemisia annua extract-coated copper nanoparticle ointment on the antioxidant enzyme activity in second-degree burns in mice. After the green synthesis of coated copper nanoparticles, 100 male mice were divided into five groups: control without treatment, eucerin ointment group, 0.2% copper nanoparticle ointment, 0.2% copper nanoparticles coated with Artemisia annua extract ointment, and 5% Artemisia annua extract ointment. The activity of antioxidant enzymes and the level of lipid peroxidation in tissue homogenates were measured on days 14, 7, 3, and 21. SOD, CAT, and GPX activities were all significantly higher on day 7 in the coated copper nanoparticle ointment group compared to the control group (P˂0.05). The level of MDA was also significantly lower in the control group on days 7, 14, and 21 (P 0.05). The extract of the medicinal plant Artemisia annua is useful for making and coating copper nanoparticles. In addition to the advantages of plant extract, copper nanoparticles have a synergistic impact that speeds up the healing of second-degree burn wounds in mice by lowering lipid peroxidation in wound tissue and boosting antioxidant activity.

Alzheimer's is the most common neurodegenerative disease of the elderly. Oxidative stress and inflammation play an important role in Alzheimer's disease. The risk of Alzheimer's disease is high in diabetic people, and insulin resistance occurs in the brain of Alzheimer's patients. Accumulation of amyloid plaques leads to angiogenesis and increased permeability of the vessels. Today, medicinal plants are receiving attention due to fewer side effects than chemical drugs. In the present study, the protective effect of Artemisia herbal product (artemisinin) along with endometrial stem cells containing the antiangiogenesis gene (thrombospondins-1 or TSP-1) was investigated in Alzheimer's disease induced by streptozotocin in a diabetic male rat laboratory model. 3 days after the induction of Alzheimer's and diabetes using streptozotocin, the animals received stem cells intranasally and then received artemisinin for one month (50 mg/kg). Initial and final weight, blood sugar, and interleukin-6 serum levels were measured, and brain amyloid plaques were examined by hematoxylin-eosin staining. The results showed that the induction of Alzheimer's and diabetes led to a significant decrease in body weight and an increase in blood sugar, interleukin-6, and brain amyloid plaques. Treatment with artemisinin and stem cells, separately and simultaneously, improved these parameters. The findings of this research showed that human endometrial stem cells that contain the TSP-1 gene can be used as a potential source of stem cells along with natural antioxidants artemisinin to reduce the symptoms of Alzheimer's disease.