AS1411aptamer conjugated liposomes for targeted delivery of arsenic trioxide in mouse xenograft model of melanoma cancer.

Development of AS1411aptamer-conjugated liposomes for targeted delivery of arsenic trioxide is the primary goal of this study. AS1411aptamer was used as ligand to target nucleolin, which is highly expressed on the surface of melanoma cancer cells. The targeted liposomes were constructed by the thin film method, and arsenic trioxide was loaded as cobalt (II) hydrogen arsenite (CHA) to increase the loading efficiency and stability of the liposomes. The liposomal structure was characterized by Fourier Transform Infrared Spectroscopy (FT-IR) and field emission scanning electron microscopy (FESEM). In addition, particle sizes and zeta potential of the CHA-loaded liposomes (CHAL) and aptamer-functionalized CHA-loaded liposomes (AP-CHAL) were determined. In vitro cytotoxicity of CHAL and AP-CHAL were evaluated using MTT assay in murine melanoma (B16) and mouse embryonic fibroblast (MEF) cell lines. The encapsulation efficiency of CHAL and AP-CHAL was reported as 60.2 ± 6.5% and 58.7 ± 4.2%, respectively. In vivo antitumor activity of CHAL and AP-CHAL in the B16 tumor-xenograft mouse model was dramatically observed. All mice of both groups survived until the end of treatment and showed body weight gain. The tumor protrusion completely disappeared in 50% of the mice in these groups. Furthermore, histopathology studies demonstrated that CHAL and AP-CHAL did not induce significant toxicity in healthy mice tissues. However, unlike the CHAL group, which showed an initial increase in tumor volume, a specific antitumor effect was observed in the AP-CHAL group from the beginning of treatment. The results showed that AP-CHAL can be used as an effective drug delivery system with high potential in the treatment of solid tumors.

Histopathological evaluation of the effect of melatonin gel on bone regeneration in rat model.

Background: The purpose of this research was to investigate the effects of different doses of topical melatonin gel on bone regeneration in rat calvarial defects using histological analysis. Materials and Methods: Fifteen adult female Wistar rats weighing approximately 200 g were used and 8 mm in diameter defects were created in their calvaria. The rats were divided into three groups: 1.2% melatonin gel, 5% melatonin gel, and the control group. The animals were sacrificed after 4 weeks. Hematoxylin and eosin staining were used to prepare histological sections. Statistical analysis was performed using the Analysis of variance and Tukey's post-hoc test. P < 0.05 was considered significant. Results: The results showed a significant difference in rate of ossification (P < 0.001), area of new capillaries (P = 0.002), and mean degree of inflammation (P < 0.001) between the three groups. Comparing groups pairwise, degree of inflammation (P = 0.003) and area of new capillaries (P = 0.019) were significantly lower in the 5% melatonin gel group than the 1.2% melatonin gel group (P = 0.003). The percentage of ossification was substantially greater in the 5% melatonin gel group than in the control and 1.2% melatonin gel groups (P < 0.001). Conclusion: Within the limitations of this animal study, our findings revealed that melatonin gel can be used as a stimulant of bone formation. Outcomes in this study show increased percentage of ossification in the melatonin groups when compared with the control, in a dose-dependent manner, as 5% melatonin gel has a greater effect on ossification.

Study on the effect of medicinal leech therapy (Hirudo medicinalis) on full-thickness excisional wound healing in the animal model.

The possible impacts of alternative and conventional medicines on wound healing are now of growing interest. This study aimed to evaluate and elucidate the wound healing activity of medicinal leech therapy in wound excision of the rat model. After a round, full-thickness excision was made in the dorsal region of the body, the animals (n = 30) were randomly divided into three equal groups: I) the treatment group (MLT), where the wounds received leech treatment; II) the positive control group (PC), where the wounds received 1% sodium phenytoin treatment; and III) the negative control group (NC), where the wounds did not receive any treatment. On days 6 and 16, wound biopsy specimens were taken, and prepared sections were stained using various methods. The contraction rate differed significantly (P < 0.05) between the NC group and the other groups. The histopathological evaluation revealed that MLT group showed an accelerated healing process and lower inflammatory response compared to other groups. In ML-treated group maturation and remodeling of collagen had occurred, while in 1% sodium phenytoin treated group, proliferation was the prominent feature. Results showed that the fibroblast was significantly lower in the NC group in comparison to other groups. The number of MNC, s, and PMN, s was significantly higher in the NC group compared to other groups (P < 0.0001). In our study, medicinal leech therapy had a higher success rate in healing for the treatment of excisional wounds in animal models.

Nephrotoxicity of Albendazole and Albendazole Loaded Solid Lipid Nanoparticles in Mice with Experimental Hydatidosis.

Purpose: Cystic echinococcosis (CE) is a serious contemporary public health problem. Different CE treatment methods are of considerable importance, with albendazole (ABZ) being one of the most preferred drugs for CE treatment and prophylaxis. In this study, we evaluated the nephrotoxicity caused by ABZ and ABZ-loaded solid lipid nanoparticles (SLNs) in mice with experimental hydatid cyst. Methods: ABZ-loaded SLNs were produced by micro-emulsification and a high shear homogenization technique. Thereafter, we evaluated the physicochemical characterization of the product. Live protoscolices were injected into mice to induce experimental hydatidosis. Mice were then treated with ABZ and ABZ-loaded SLNs. The nephrotoxicity effects were evaluated by biochemical and histopathological surveys. Results: Significantly different blood urea nitrogen (BUN) levels were observed between the two infected groups (ABZ treatment and ABZ-loaded SLN treatment) and the control group. The kidney malondialdehyde (MDA) and glutathione (GSH) levels of the infected groups were not significantly different from those of the control group. The histopathological study revealed nephropathic and pathologic changes in the ABZ and ABZ-loaded SLN groups. Conclusion: ABZ formulated for ABZ-loaded SLNs had a more prominent chemoprophylactic efficacy on CE and fewer side effects than ABZ alone. Neither ABZ nor ABZ-loaded SLNs caused significant biochemical and histopathological defects on the kidney, and all functional biochemical markers stayed within the normal range. Therefore, ABZ-loaded SLNs could be a potential new product for CE treatment.

Evaluation of Wound Healing Activity of Sea Cucumber Holothuria parva Hydroalcoholic Extract in Rat.

A significant challenge in biomedicine is the development of Biomaterials with the potential to accelerate wound healing. The aim of this study was to investigate the effect of the gel prepared from sea cucumber on wound healing in rats. Full-thickness wounds were created in male rats divided into five experimental groups, negative control (NC), positive control (PC), and treatments. The NC and PC groups received respectively gel base and phenytoin cream 1%. Treatment groups were treated topically by gels of 1%, 3%, and 5% Holothuria parva extract (HPE) in the gel base. The rats were sacrificed on days 7, 14, and 21. Pathological reports revealed the proliferation of keratinocytes in the borders of the wound in treatment groups and controls. Formation of granulation tissue was seen on day 7 in treatment groups, collagen fibers in granulation tissue were randomly organized, and the rate of fibroblast decreased. Results showed that there were statistically significant differences in wound contraction between all groups in comparison to the NC group (P < .05) on day 8. It was concluded that the 1% HPE gel has a good potential for promoting wound healing. [Formula: see text].

The potential therapeutic effect of adipose-derived mesenchymal stem cells in the treatment of cutaneous leishmaniasis caused by L. major in BALB/c mice.

Leishmaniasis is one of the most neglected tropical infectious diseases in the world. The emergence of drug resistance and toxicity and the high cost of the available drugs with a lack of new anti-leishmanial drugs highlight the need to search for newer therapies with anti-leishmanial activities. Due to the mesenchymal stem cell (MSC) immunomodulatory capacity, they have been applied in a wide variety of disorders. In this study, the potential effects of adipose-derived MSC (AD-MSCs) therapy and its combination with glucantime were evaluated in a murine model of cutaneous leishmaniasis induced by L. major. The results showed that AD-MSCs improved wound healing and decreased parasite burden. The real-time PCR results obtained from mice treated with AD-MSCs showed that IL-12 and TNF-α genes were upregulated. IL-10, arginase, and FOXP3 genes were downregulated whereas no differences in expression of the IL-4 gene were found. Overall, it seems that AD-MSCs therapy enhances Th1 immune response in L. major infected BALB/c mice. Unexpectedly, our results showed that the association of glucantime to AD-MSCs treatments did not lead to an increment in the anti-leishmanial activity.

Chemical profiling and anti-psoriatic activity of marine sponge (Dysidea avara) in induced imiquimod-psoriasis-skin model.

Since Marine sponge Dysidea avara is regarded as a source of anti-inflammatory compounds, we decided to evaluate its potential anti-psoriatic activity in a psoriasis Imiquimod-induced in the mouse model. Psoriatic mice were treated with three different methanolic extracts of Dysidea avara compared with betamethasone-treated mice in in- vivo studies. Clinical skin severity was assessed with the psoriasis area index (PASI), whilst ELISA detected the expression of TNF-α, IL-17A, and IL-22. Dysidea avara activity was studied by employing GC-MS (to distinguish compounds), HPTLC (for skin permeation and accumulation), and SEA DOCK to predict single compound potential anti-inflammatory activity. After 7 days of treatment, mice treated with Dysidea avara displayed a dose-dependent, statistically significant improvement compared to controls (p< 0.001). In line with the clinical results, ELISA revealed a statistically significant decrease in IL-22, IL-17A, and TNF-α after treatment; the same SEA DOCK analysis suggests a possible anti-psoriatic activity of the extracts.

Helicobacter genus in the intestine and liver of stray cats: the molecular, histopathological, and immunohistochemical study.

OBJECTIVES: The study was designed to determine the presence of Helicobacter genus and three species of H. pylori, H. bilis, and H. canis, in the duodenum, ileum, colon, and liver of stray cats. Moreover, the histopathological and immunohistochemical analyses have been performed. METHODS: Samples were taken from the duodenum, ileum, colon, and liver of 30 cats for molecular and histopathological evaluations. Polymerase chain reaction was carried out for the detection of the Helicobacter genus in the mentioned samples. Then, species-specific primers were used in Helicobacter-positive samples. RESULTS: Helicobacter genus prevalence rates in the duodenum, ileum, colon, and liver samples were 50%, 60%, 50%, and 43.3%, respectively. Helicobacter pylori, H. canis, and H. bilis were isolated from at least one tissue of 18 (60%), 13 (43.3%), and 8 (26.7%) of the cats, respectively. Immunohistochemical findings confirmed the presence of bacteria in the intestinal crypt or the mucosal layer of duodenum, ileum, colon, and hepatic sinusoids. CONCLUSION: In the present study, the concurrent infection of duodenum and liver was noticeable. Furthermore, the high prevalence of H. pylori in cats, as a well-known human pathogen, should be considered. High incidence of Helicobacter in gut and liver of Ahvaz stray cats is noticeable. According to the zoonotic importance of Helicobacter, more studies in the field of treatment and prevention are highly recommended.

Concurrent occurrence of granulosa cell tumor, uterine adenomyosis, cystic endometrial hyperplasia and uterine serosal inclusion cyst in a bitch.

An eleven-year-old Doberman-German Shepherd mixed bitch was presented with vulvar enlargement, vaginal discharge, and bleeding for two months and a week before, respectively. The dog was operated for routine ovariohysterectomy. During the surgery, a liquid-filled sac was observed on the ventrolateral border of the right uterine horn. The sac was ligated and excised. The uterine horns and ovaries were stained for histopathological evaluation. Granulosa cell tumor (GCT), adenomyosis (CUA), endometrial cystic hyperplasia (CEH), and uterine serosal inclusion cyst (USC) were diagnosed through histopathology assessment. Following up, 12 weeks after surgery revealed that the patient was in good condition with a good appetite and without any vaginal discharge. It seems the initial problem of the present bitch and the main cause of clinical signs was GCT. Probably, other abnormal conditions including CUA, CEH, and USC occurred as a result of hormonal disturbance associated with GCT. This report described the concurrent occurrence of GCT, CUA, CEH, and USC in a bitch as it has not been reported before.

Histopathological and cytological analyses of endometrium in water buffaloes (Bubalus bubalis) to detect estrus and endometritis.

This study aimed to determine cytological, histopathological and cytomorphometrical characteristics of endometrium in healthy and endometritic uterus in the water buffalo. Fifty eight non-pregnant reproductive systems were collected from slaughterhouse. Efficiency of three methods of sampling including cotton swab, smear, and aspiration were compared for cytologic study. Concurrent histopathologic examination revealed endometritis in 38 uteri including 8 (21.00%) with mild endometritis, 7 (18.42%) with moderate endometritis, 6 (15.90%) with severe endometritis and 17 (44.73%) with chronic endometritis. Cyto-morphometrical results showed significant relationship between diameter and area of epithelial nuclei with phases of estrus cycle. Neutrophil and lymphocytes densities in swab and aspiration samples were significantly higher in severe endometritis than normal and chronic endometritis samples. Similarly, lymphocytes density in smear and aspiration methods was significant between normal and moderates, and also severe and chronic endometritis. Cytomorphometric analysis of epithelial nuclei characteristics (diameter and area) in buffalo were performed for the first time and it could be valuable to identify estrus cycle in this species. Aspiration had the most efficiency to identify endometritis in comparison with other methods.

Embryonated pigeon eggs as a model to investigate Neospora caninum infection.

It has been shown that embryonated chicken eggs can be used as animal models for experimental infections. The aim of the present study was to investigate pigeon embryonated eggs as animal models for experimental neosporosis. An infection with Neospora caninum Nc1 isolate was conducted in chicken and pigeon embryonated eggs to evaluate LD50. After calculation of LD50, 2LD50 of tachyzoites were injected into the eggs. Macroscopic changes of each embryo were observed, and immunohistochemistry (IHC) and molecular methods were used to investigate the parasitic distribution in the tissues. In the present study, histopathological changes were considered, and sections of those used for histopathological examination including the heart, liver, brain and chorioallantoic (CA) membrane were also subjected to IHC. Pigeon embryos showed more macroscopic changes than chicken embryos. A hemorrhage of the CA membrane was the main gross lesion. Microscopic examination of tissues revealed acute neosporosis due to hemorrhage, necrosis and infiltration of mononuclear inflammatory cells. Based on IHC and molecular results, the parasite DNA was detected in the liver, heart and CA membrane. As with chicken embryonated eggs, these results reinforce the susceptibility of pigeon embryonated eggs to N. caninum, and provide new insights into using an inexpensive and available animal model for N. caninum research. The results of the present study suggest that pigeon embryos may be a good choice for studying the biology of N. caninum in living organisms.

Case report of chondroma in a grass carp (Ctenopharyngodon idella).

The grass carp (Ctenopharyngodon idella) is a herbivorous, freshwater fish species of the family Cyprinidae, and the only species of the genus Ctenopharyngodon. Neoplasms in fishes are generally less aggressive than neoplasms in mammals and are most commonly discrete, focal and benign neoplasms. A 3-year-old grass carp with a big mass on the vertebrae was referred to the clinic. According to the owner's statements, the fish had no signs of lethargy, ataxia and abnormal behaviors. The size of the mass was 7 × 6 × 6 cm. It cut hardly with audible sounds. The consistency of the mass was as hard as a cartilage. Microscopic examination revealed numerous irregular crests of hyaline cartilage beneath the skin. According to histopathologic characteristics, chondroma on the vertebrae of grass carp was diagnosed.

Rhabdomyosarcoma in a Silver Carp.

Rhabdomyosarcoma is a primitive neoplasm that originates from skeletal muscle progenitor cells. In a routine inspection of a cyprinid farm in southwestern Iran, an approximately 2-year-old female Silver Carp was observed to have a raised mass located on the dorsolateral surface just caudal to the head. Macroscopic examination revealed a firm irregular fleshy pink mass (5 × 4 cm, depth = 3 cm) that appeared to arise from the subcutaneous musculature. Histologic sections were prepared using routine methods and separate sections were stained with hematoxylin-eosin and Massons' trichrome. Microscopically, the tumor mass was composed of spindle cells that were densely packed and arranged in long interwoven bundles. The nuclei were vesicular and oval to elongated or cigar-shaped. Nuclear pleomorphism and multinucleate tumor giant cells were clearly evident. The neoplastic cell cytoplasm was eosinophilic with indistinct cell margins, and clear cross striations were observed in fibrils. The striated fibrils stained diffusely red with Masson's trichrome. This account represents the first reported occurrence of rhabdomyosarcoma in Silver Carp Hypophthalmichthys molitrix. Received July 10, 2015; accepted February 4, 2016.

Statistical optimization of tretinoin-loaded penetration-enhancer vesicles (PEV) for topical delivery.

BACKGROUND: The aim of this study was to develop and optimize deformable liposome for topical delivery of tretinoin. METHODS: Liposomal formulations were designed based on the full factorial design and prepared by fusion method. The influence of different ratio of soy phosphatidylcholine and transcutol (independent variables) on incorporation efficiency and drug release in 15 min and 24 h (responses) from liposomal formulations was evaluated. Liposomes were characterized for their vesicle size and Differential Scanning Calorimetry (DSC) was used to investigate changes in their thermal behavior. The penetration and retention of drug was determined using mouse skin. Also skin histology study was performed. RESULTS: Particle size of all formulations was smaller than 20 nm. Incorporation efficiency of liposomes was 79-93 %. Formulation F7 (25:5) showed maximum drug release. Optimum formulations were selected based on the contour plots resulted by statistical equations of drug release in 15 min and 24 h. Solubility properties of transcutol led to higher skin penetration for optimum formulations compared to tretinoin cream. There was no significant difference between the amount of drug retained in the skin by applying optimum formulations and cream. Histopatological investigation suggested optimum formulations could decrease the adverse effect of tretinoin in liposome compared to conventional cream. CONCLUSION: According to the results of the study, it is concluded that deformable liposome containing transcutol may be successfully used for dermal delivery of tretinoin.

Toxicity evaluation of microemulsion (nano size) of sour cherry kernel extract for the oral bioavailability enhancement.

BACKGROUND: In the recent years nanostructured materials have been the focus of researches due to their wide-spread possibilities to provide new shapes and structures for some materials. Microemulsions can provide uniform nano-sized droplets for templating. Microemulsions are isotropic, thermodynamically-stable systems of oil, water and surfactant with a 20-200 nm droplet size. They can be prepared as oil-in-water (o/w), water-in-oil (w/o) or bicontinuous systems, depending on the equilibrium spontaneous curvature of the surfactant layer at the oil-water interface. OBJECTIVES: The aim of this study was to introduce a system designed to improve and enhance the bioavailability of bioflavonoids in the Prunus cerasus (sour cherry) seed kernel extract by developing a novel delivery system, i.e. microemulsion (nanosized particles). MATERIALS AND METHODS: Microemulsion formulations were prepared by mixing appropriate amounts of surfactants (Tween 80 and Span 20), cosurfactant (propylene glycol) (3:1 ratio), and oil phase (olive oil). The prepared microemulsions were evaluated regarding their mean droplet size, transparency, viscosity, and pH. Sour cherry kernel extract microemulsion was orally administered to mice at doses of 2.5%, 5%, and 10% for 10 days. On the last day, their blood as well as their liver and kidney were used for biochemical and histopathological analyses, respectively. RESULTS: Biochemical factors levels and the pathological study indicated that there were not significant differences in microemulsion extracts compared with the control group (P > 0.05). CONCLUSIONS: Not only no toxicity evidence of this product was observed in the dose range used in foods or healthcare, but also it improved the cardiac function recovery.

Effect of topical Nanoliposomes of Paromomycin on Rats Liver and Kidney.

BACKGROUND: Hepatotoxicity due to drugs is the most common cause of deaths. Nephrotoxicity of the drugs is usually associated with the drugs accumulation in renal tissue. Paromomycin sulfate (PMS) is an anti-leishmania drug. Although the topical approach for the treatment of leishmania is attractive, its use might cause nephrotoxicity and hepatotoxicity. OBJECTIVES: This study aimed to evaluate probable nephrotoxicity and hepatotoxicity of topically administered PMS liposomes. MATERIALS AND METHODS: Nine groups of male rats were used in this study; each group consisted of 6 rats that were evaluated in 3 time periods of 10, 20, and 30 days. Three groups were placed in each time period; a control group did not receive any medicine; a negative control group received liposome without paromomycin sulfate; and a positive control group received nanoliposomal formulations containing paromomycin sulfate. Pharmaceutical formulation (topical form) was used 2 times a day in a 12-hour interval. At the end of the period, hepatic enzymes (ALT, AST, and ALK), BUN levels, and serum creatinine were measured. RESULTS: The results showed that no significant change was occurred in the amount of the above factors compared with the control group with the negative control group in 3 time periods (P > 0.05). The histopathological results of the liver and kidney showed that there was no difference in the between the negative control and positive control groups and the control group in the 10- and 20-day periods, and they had a normal structure. However, after the 30-day time period a reversible cellular inflammation in the liver and mild kidney necrosis was seen in the positive control group versus the control and negative control groups. CONCLUSIONS: In general, it can be said that the application of nanoliposomal paromomycin sulfate formulations for topical treatment of the cutaneous leishmaniasis does not create serious side effects in the short term, but its long-term use leads to mild renal and liver side effects that requires more attention.

Classification and grading of canine malignant mammary tumors.

Histological grading is a good parameter to stratify tumors according to their biological aggressiveness. The Elston and Ellis grading method in humans, invasive ductal breast carcinomas and other invasive tumors are routinely used. The aims of this study were classification of mammary gland tumors and also application of a human grading method in canine mammary carcinoma. The samples included 37 tumors of mammary glands. Mammary tumors were carcinomas (n = 32) and sarcomas (n = 5). The carcinomas were classified as simple carcinoma 56.8% (n = 21), complex carcinoma 13.5% (n = 5), carcinoma arising from benign tumor 10.8% (n= 4) and special type of carcinoma 5.4% (n = 2). Out of 32 carcinomas studied, 37.5% (n = 12) grade I, 46.9% (n = 15) grade II and 15.6% (n = 5) grade III. This study demonstrated that the Elston and Ellis method of histological grading in canine mammary tumor is a reliable prognostic factor which is correlated with histopathological classification.

Effects of Echinacea purpurea on Hepatic and Renal Toxicity Induced by Diethylnitrosamine in Rats.

BACKGROUND: Nitrites are mainly used in food preservation. These materials could change to nitrosamine due to the effect of heat and gastric acid. Nitrosamine is absorbed in intestine and enters the liver and hepatocytes by portal venous system, and hampers the detoxification system of liver by interfering in cytochrome P450 enzymes, so, the liver gently proceeds to cirrhosis and cancer. OBJECTIVES: The current study aimed to investigate the hepatic and renal protective effects of aerial parts of Echinacea purpurea extract (EPE) on injury induced by diethylnitrosamine (DEN). MATERIALS AND METHODS: Twenty Wistar rats were divided into 4 groups. Groups were as follow: Control group (normal saline), DEN (200 mg/kg, IP, a single dose), EPE (100 mg/kg, orally, daily) and DEN + EPE which received as group DEN and EPE. After 30 days, Blood samples, and liver and kidney tissues were taken for further examination. Aspartate transaminase (AST), alanine transaminase (ALT), alkaline phosphatase (ALP), BUN, Creatinine and total and direct bilirubin were estimated in serum. RESULTS: DEN induced hepatotoxicity and nephrotoxicity in all the treated animals by elevated serum ALT, AST, ALP and BUN, creatinin and total and direct bilirubin levels. AST, BUN and total and direct bilirubin significantly decreased in DEN + EPE compared to DEN group. After 30 days of DEN administration, histopathological investigation revealed proliferation of hepatic stellate cells and early fibrosis which were partly improved by EPE administration. CONCLUSIONS: The current study findings indicated that Echinacea purpurea extract played an important role in the protection against DEN toxicity in rats.

Preventive effects of pomegranate seed extract on bleomycin-induced pulmonary fibrosis in rat.

BACKGROUND: Oxidative stress plays an important role in the pathogenesis of bleomycin-induced lung fibrosis and many antioxidant agents have been used for the treatment of this disease in animals. OBJECTIVES: To evaluate the antioxidant effects of pomegranate seed extract (PSE) on bleomycin treated rats. MATERIALS AND METHODS: Male Spraque - Dawley rats were divided into 5 groups: rats in groups I (bleomycin) and II (control) were given a single dose of bleomycin (7.5 IU/kg, intratracheally) in the bleomycin group and same amount of saline in the control, respectively. Treatment groups (III-V) were given PSE (100,200,400 mg/kg) orally a week before the bleomycin injection and this was continued for 3 weeks. At day 28, animals were sacrificed and lungs were removed for histological investigation. RESULTS: Histological analysis showed that PSE could prevent pathological changes that were seen in the bleomycin group. CONCLUSIONS: Results of the present study showed that hydroalcoholic extracts of pomegranate seeds had a significant protective effect against bleomycin-induced lung fibrosis by its antioxidant properties. The highest protective effect was observed for the 400 mg/kg dose.

Protein 53 expression in a mixed Labrador subcutaneous lymphoma.

An 11 year - old mixed female Labrador was presented with two masses in trunk and neck. The tumoral masses were excised and sent for histopathological and immunohistochemical analyses. Histopathological examination of masses revealed diffuse infiltration of small sized lymphoid cells in subcutaneous tissue which were intense around the blood vessels. More than 10% lymphoid cells were CD3 positive in the immunohistochemical staining and most of them were accumulated around vessels. Protein 53 (p53) expression was detected by brown nuclei in immunohistochemical staining. Subcutaneous lymphoma was diagnosed according to histopathological results. After 6 months the case was referred with multicentric lymphoma and based on the owner request euthanasia was performed. These findings emphasize on poor prognosis for tumors with p53 mutation.