Mustafa Yavuz Gulbahar

Subacute oral toxicity of combinations of selected synthetic pyrethroids, piperonyl butoxide, and tetramethrin in rats

In this study, 70 Wistar rats were randomly divided into seven equal groups (six experimental and one control), which consisted of animals belonging to both sexes. Different combinations of insecticides were administered daily to the experimental groups (group 1: cypermethrin + piperonyl butoxide (PBO); group 2: alphacypermethrin + PBO; group 3: deltamethrin + PBO; group 4: cypermethrin + PBO + tetramethrin; group 5: alphacypermethrin + PBO + tetramethrin; and group 6: deltamethrin + PBO + tetramethrin) for 28 days. During the study period, mortality and serious clinical findings were not observed in any animal. However, feed consumptions decreased in groups 1 and 3 (p < 0.05). Red blood cells, white blood cells, and hemoglobin levels, especially in cypermethrin and alphacypermethrin groups (groups 1, 2, and 4), were found to be higher than the control group (p < 0.05). Furthermore, biochemical changes related to liver, kidney functions, and protein metabolism occurred in males of almost all the groups. Relative liver and kidney weights of the male animals increased in the cypermethrin and alphacypermethrin groups (p < 0.05). The most common finding observed during the histopathological examination of all the experimental groups was centrilobular degeneration in the liver. It was concluded that although clinical symptoms were not observed, synthetic pyrethroid, synergist, and knockdown agent combinations might cause serious abnormalities when administered in certain doses in mammalians.

Repeated-dose 14-day dermal toxicity of different combinations of some synthetic pyrethroid insecticides, piperonyl butoxide, and tetramethrin in rats

The aim of this study was to evaluate the repeated-dose 14-day dermal toxicity of different combinations of some synthetic pyrethroid insecticides, piperonyl butoxide, and tetramethrin in rats. A total of 70 adult Wistar rats were randomly divided into 7 (6 experimental and 1 control) groups. Different combinations of insecticides were dermally applied to the rats in the experimental groups for 14 days. Clinical observations were performed daily; hematologic and biochemical parameters were also determined. Gross necropsy and histopathologic examinations were performed systematically, and organ weights were recorded. Although the administered doses of the insecticides were relatively lower than their acute dermal toxicity values, a high mortality rate (27 of 60 experimental animals, 45%) was observed. Furthermore, the insecticide combinations caused decreased body weights and feed consumptions, increased organ weights, and hematologic, biochemical, and common histopathologic changes. As a result, the findings showed that although pyrethroids are considered to be of low acute toxicity, they become more toxic when combined with piperonyl butoxide or tetramethrin in certain doses.

The expressions of HSP70 and αB-crystallin in myocarditis associated with foot-and-mouth disease virus in lambs.

This study describes the expression of heat shock protein70 (HSP70) and alpha-basic-crystallin (α-BC) and their association with apoptosis and some related adaptor proteins in the pathogenesis of foot-and-mouth disease virus (FMDV)-induced myocarditis in lambs. HSP70 was generally overexpressed in the myocardial tissues and inflammatory cells of FMDV-induced myocarditis with differential accumulation and localization in same hearts when compared to non-foot-and-mouth disease control hearts. α-BC immunolabeling showed coarse aggregations in the Z line of the cardiomyocytes in FMDV-infected hearts in contrast to control hearts. Overall, the results of this study show that the anti-apoptotic proteins, HSP70 and α-BC, were overexpressed with increased apoptosis in FMDV-infected heart tissues. Both proteins failed to protect the cardiomyocytes from apoptosis as defense mechanisms to the FMDV during the infection, suggesting that the virus is able to increase apoptosis via both downregulation and/or upregulation of these anti-apoptotic proteins.

Immunohistochemical Analysis of Reconstructed Sheep Mandibles: Transport Distraction Osteogenesis Versus Autogenous Bone Grafting

PURPOSE Although many studies have been conducted that related to growth factor expression in mandibular distraction osteogenesis, to our knowledge, no study comparing the immunohistochemical outcomes of autologous bone grafting (ABG) and transport distraction osteogenesis has been conducted up to now. The aim of this study was to histologically and immunohistochemically analyze newly formed bone in the resected mandible reconstructed by transport distraction osteogenesis and iliac crest bone grafting in a sheep model. MATERIALS AND METHODS Mandibular discontinuity defects created in the jaws of sheep were reconstructed by distraction osteogenesis (n = 7) and bone grafting (n = 7) and allowed to heal for 3 mos. The animals were then sacrificed and their jaws resected and prepared for decalcification. Histological and immunohistochemical examinations of transforming growth factor-beta 1 (TGF-β1) and bone morphogenetic protein (BMP) -2, -4 were performed in the newly formed bone in the defect area. RESULTS Positive staining for BMP-2, -4, and TGF-β was observed in the cells and matrix components. BMP is present in both processes, but the expression of BMP-2, -4, and TGF-β in the distraction regenerate is stronger when compared with bone graft healing. CONCLUSIONS The only limitation of the present study was that it evaluated the role of BMP-2, -4, and TGF-β expressions in bone repair process at 3 mo postoperatively. Determination of growth factor expression at more than 1 time point would be ideal in elucidating the role of these factors during bone healing.

Immunohistochemical detection of autophagy-related microtubule-associated protein 1 light chain 3 (LC3) in the cerebellums of dogs naturally infected with canine distemper virus.

We investigated the expression of microtubule-associated protein 1 light chain 3 (LC3) protein in the cerebellums of dogs infected with canine distemper virus (CDV) using immunohistochemistry to detect autophagy. The cerebellums of 20 dogs infected with CDV were used. Specimens showing demyelination of white matter were considered to have an acute infection, whereas specimens showing signs of severe perivascular cuffing and demyelination of white matter were classified as having chronic CDV. Cerebellar sections were immunostained with CDV and LC3 antibodies. The cytoplasm of Purkinje cells, granular layer cells, motor neurons in large cerebellar ganglia and some neurons in white matter were positive for the LC3 antibody in both the control and CDV-infected dogs. In the infected cerebellums, however, white matter was immunostained more intensely, particularly the neurons and gemistocytic astrocytes in the demyelinated areas, compared to controls. Autophagy also was demonstrated in CDV-positive cells using double immunofluorescence staining. Our findings indicate that increased autophagy in the cerebellum of dogs naturally infected with CDV may play a role in transferring the virus from cell to cell.

Immunohistochemical characterization of peroxisome proliferator-activated receptors in canine normal testis and testicular tumours.

Peroxisome proliferator-activated receptors (PPARs) are ligand-activated transcription factors belonging to the nuclear hormone receptor superfamily. Recent studies have demonstrated that PPARs regulate lipid metabolism and are expressed in various cancers. The aim of the present study was to investigate the expression of PPAR-α, -β and -γ in normal canine testicular tissue and canine testicular tumours (CTTs). Expression of PPAR-α, -β and -γ was greater (P <0.05) than in normal testicular tissue. PPARs were therefore induced in CTTs and they may play a role in the biology of these tumours.

Alpha basic crystallin expression in canine mammary tumors.

The aim of this study was to evaluate prognostic and/or diagnostic factors of canine mammary tumors by immunohistochemically analyzing the expression of alpha basic crystallin (αB-c). For this, formalin-fixed, paraffin-embedded blocks of 51 naturally-occurring canine mammary tumors (11 benign and 40 malignant) were used. Tissue from eight normal canine mammary glands were served as a control. Immunohistochemically, in the control mammary tissues, a few luminal epithelial cells were αB-c positive but myoepithelial cells were negative. In benign or simple type malignant tumors, αB-c expression was observed in luminal epithelial cells while the myoepithelial basal cells were negative. In benign or complex type malign tumors, positive staining was predominantly found in the cytoplasm of epithelial cells. Immunoreactivity of αB-c was also observed in neoplastic myoepithelial cells. Statistically, the number of cells immunolabeled with αB-c was found to be significantly different among tissues from normal canine mammary glands, benign lesions, and malignant tumors (p < 0.05). αB-c immunoreactivity was higher in malignant tumors than the control mammary tissues (p < 0.001). Data obtained in the current study revealed a strong association between high expression levels of αB-c and primary mammary gland tumors in canines.

Nesidioblastosis in a Simmental Calf

A 2-day-old Simmental calf with arthrogryposis and astasia was subjected to necropsy examination. The calf was normoglycaemic and normoinsulinaemic. Microscopically, pancreatic tissue was hyperplastic with an irregular lobular arrangement of pancreatic islets. Newly-formed islet cells budded from intralobular or intercalated ducts (so-called ductulo-insular complexes) and there were prominent blood vessels with telangiectatic features surrounded by rows of cuboidal-columnar islet cells. The newly-formed islets expressed insulin antigen immunohistochemically. The lesion was diagnosed as nesidioblastosis, an uncommon abnormality previously associated with the double muscling trait in cattle.

The Effect of Infliximab on Intestinal Anastomosis Healing in Rats

Intestinal anastomosis healing is a complex physiological process in which many local and systemic factors play a role. One of the significant cytokines in this process is TNF-α. Infliximab is a chimeric monoclonal antibody which binds to TNF-α with high affinity. Although this agent is used in ulcerative colitis and Crohns disease, intestinal surgery may be required in these patients. In this study it was aimed to determine whether or not there was any negative effect of preoperative single dose infliximab treatment on intestinal anastomosis healing. Two groups of 10 rats were formed. One of these groups was administered with a single dose of infliximab 8 mg/kg as a 20-minute intravenous infusion from the femoral vein. Four days after the infusion, a full layer incision was made to the colon and anastomosis was applied to all the rats. At 7 days after anastomosis, the subjects were sacrificed. The anastomosis segment was removed and the bursting pressure was measured. Tissue samples were taken from this segment for hydroxyproline concentration and histopathological examination. A blood sample was taken to measure TNF-α values. No statistically significant difference was determined between the groups in terms of bursting pressure, tissue hydroxyproline concentration or histopathological scoring. A single dose of 8 mg/kg infliximab administered 4 days preoperatively was not found to have any negative effect on intestinal anastomosis healing in rats.

IMMUNOHISTOCHEMICAL DISTRIBUTION OF ALPHA B-CRYSTALLIN IN THE CEREBELLUM OF DOGS INFECTED WITH CANINE DISTEMPER VIRUS

The cerebella of 12 dogs infected with canine distemper virus (CDV) and those of three normal dogs were examined. The avidin-biotin-peroxidase complex technique was used to detect alphaB-crystallin (alphaB-c) immunoreactivity and immunolocalisation of the CDV antigen. CDV antigens, immunopositive astrocytes, oligodendrocytes and granular neurons were seen in both the white and grey matter of the infected dogs. In the controls, alphaB-c immunopositive glial cells were seen in the white matter and around the Purkinje cells. In dogs with distemper, alphaB-c immunoreactivity was not observed in some of the glial cells around the Purkinje cells. A significant negative correlation of P < 0.01 level was found between areas of severe demyelination and the number of alphaB-c immunopositive cells in dogs infected with CDV. Such correlation was not observed between mild and moderate demyelinating areas and alphaB-c immunostaining. The alphaB-crystallin/ total number of cells ratio was found to be significant in severely affected demyelinating areas (P < 0.05). These data indicate that there was a relationship between the degrees of CDV associated with demyelination and the level of alphaB-c expression in the glial cells.