Mesenchymal stem cells derived from epicardial adipose tissue reverse cardiac remodeling in a rabbit model of myocardial infarction.

OBJECTIVE: Myocardial infarction (MI) is one of the most important causes of death. MI-related tissue loss and cardiac remodeling may result in heart failure. Intramyocardial injection of mesenchymal stem cells derived from adipose tissues, in acute MI animal models, has shown promising regenerative capabilities. This study aimed to investigate the myocardial regenerative capacity of epicardial adipose tissue-derived mesenchymal stem cells (ADSCs) in a rabbit model of MI. MATERIALS AND METHODS: A rabbit model of MI was performed in three groups: a sham-operated group, a control group, and a treatment group. MI was induced by coronary artery ligation via thoracotomy in the first operation. Four weeks after the first operation, intramyocardial injections of phosphate-buffered saline (PBS; control group) or ADSCs (10×106 in 100 µL; treatment group) were performed in the peri-infarct zone. Four weeks after the second operation, rabbits were sacrificed for further analysis. RESULTS: A significant increase in ejection fraction (p<0.0001) was detected in the treatment group, along with a significant increase in vascular density (p<0.001) and a significant decrease in infarct size (p<0.05) compared to the control group. CONCLUSIONS: Epicardial adipose tissue is a rich source of mesenchymal stem cells, which can differentiate into cardiomyocytes, as well as having neoangiogenic properties. Due to its potential to ameliorate chronic ischemic changes in the heart, it may be preferable in cardiac regenerative cell therapies.

The Systematic Effect of Mesenchymal Stem Cell Therapy in Critical COVID-19 Patients: A Prospective Double Controlled Trial.

The aim of this clinical trial was to control the cytokine storm by administering mesenchymal stem cells (MSCs) to critically-ill COVID-19 patients, to evaluate the healing effect, and to systematically investigate how the treatment works. Patients with moderate and critical COVID-19 clinical manifestations were separated as Group 1 (moderate cases, n = 10, treated conventionally), Group 2 (critical cases, n = 10, treated conventionally), and Group 3 (critical cases, n = 10, treated conventionally plus MSCs transplantation therapy of three consecutive doses on treatment days 0, 3, and 6, (as 3 × 106 cells/kg, intravenously). The treatment mechanism of action was investigated with evaluation markers of the cytokine storm, via biochemical parameters, levels of proinflammatory and anti-inflammatory cytokines, analyses of tissue regeneration via the levels of growth factors, apoptosis markers, chemokines, matrix metalloproteinases, and granzyme-B, and by the assessment of the immunomodulatory effects via total oxidant/antioxidant status markers and the levels of lymphocyte subsets. In the assessment of the overall mortality rates of all the cases, six patients in Group-2 and three patients in Group-3 died, and there was no loss in Group-1. Proinflammatory cytokines IFNγ, IL-6, IL-17A, IL-2, IL-12, anti-inflammatory cytokines IL-10, IL-13, IL-1ra, and growth factors TGF-ß, VEGF, KGF, and NGF levels were found to be significant in Group-3. When Group-2 and Group-3 were compared, serum ferritin, fibrinogen and CRP levels in Group-3 had significantly decreased. CD45 +, CD3 +, CD4 +, CD8 +, CD19 +, HLA-DR +, and CD16 + / CD56 + levels were evaluated. In the statistical comparison of the groups, significance was only determined in respect of neutrophils. The results demonstrated the positive systematic and cellular effects of MSCs application on critically ill COVID-19 patients in a versatile way. This effect plays an important role in curing and reducing mortality in critically ill patients.

Mesenchymal stem cells treatment in COVID-19 patient with multi-organ involvement.

The aim of this study is to evaluate the therapeutic effect of mesenchymal stem cells (MSCs) in a severe case of brain and multiple organ involvement in a patient with COVID-19. Here, a 51-year-old male patient with multi-organ involvement due to COVID-19 infection and developing cardiac arrest is presented. MSCs were transplanted to the patient four times systematically and once intrathecally. As a result, the application of MSCs has been found to have a healing effect on organs in this patient with severe COVID-19 infection. In addition, transplantation of MSCs both systematically and intrathecally is considered to be effective in the treatment of the central nervous system (Tab. 2, Fig. 2, Ref. 24). Keywords: mesenchymal stem cell, COVID-19, organ involvement.

Improving effects of mesenchymal stem cells on symptoms of chronic obstructive pulmonary disease.

AIM: We aimed to identify the improving effects of umbilical cord tissue-derived (UCTD) MSCs on the symptoms of COPD in our phase 1.2 clinical study. MATERIAL METHODS: Our study consisted of five patients with COPD. Respiratory function tests, SGRQ symptom, activity and impact scores and 6-minute walk test (6MWT) were examined before UCTD MSC treatment. All the patients were administered a total of 4 doses of UCTD MSCs by intravenous infusion at two-week intervals. All the tests were repeated three months after the treatment for evaluation of the response to MSCs treatment. RESULTS: The mean age of five male patients was 56. The mean pretreatment FEV1/FVC ratios were 66.9 %. Pretreatment mean SGRQ symptom, activity and impact scores of the patients were 78.2, 83.8 and 58.02 respectively. The mean walking distance of the patients was 307 meters before MSCs treatment. The mean FEV1/FVC value of raised to 69.58 % after the treatment. The mean SGRQ symptom, activity and impact scores were noted as 39.8, 60.98 and 45.18 respectively. The mean walking distance of the patients raised to 362 meters after the treatment. CONCLUSIONS: Our results showed that four doses of MSC treatment considerably alleviated the severity of symptoms of COPD (Tab. 2, Fig. 7, Ref. 25).

Calvarial bone defects in ovariectomised rats treated with mesenchymal stem cells and demineralised freeze-dried bone allografts.

BACKGROUND: The aim of the study was to investigate the ability of a combination of bone marrow mesenchymal stem cells (BM-MSCs) with and without demineralised freeze-dried bone allografts (DFDBAs) to induce bone regeneration in calvarial defects in ovariectomised rats. MATERIALS AND METHODS: Critical size defects were filled with a combination of DFDBAs and BM-MSCs or BM-MSCs alone. Eight weeks after calvarial surgery, the rats were sacrificed. The samples were analysed histologically and immunohistochemically. RESULTS: No difference was observed in vascularisation between groups C1 (animals with cranial defect only, control group) and O1 (animals with cranial defect only, ovariectomy group). Intramembranous ossification was observed at a limited level in groups C2 (animals with cranial defect with MSCs, control group) and O2 (animals with cranial defect with MSCs, ovariectomy group) compared to C1 and O1. In group C3 (animals with DFDBAs with MSCs, control group), the fibrous structures of the matrix became compact as a result of a bone graft having been placed in the cavity, but in group O3 (animals with DFDBAs with MSCs, ovariectomy group), the fibrous tissue was poorly distributed between the bone grafts for the most parts. CONCLUSIONS: We conclude that the insertion of BM-MSCs enhances bone healing; however, the DFDBA/BM-MSC combination has little effect on overcoming impaired bone formation in ovariectomised rats.

Neuronal regeneration in injured rat spinal cord after human dental pulp derived neural crest stem cell transplantation.

OBJECTIVE: This study aimed to analyze the effect of human Dental Pulp-Neural Crest Stem Cells (hDP-NCSCs) delivery on lesion site after spinal cord injury (SCI), and to observe the functional recovery after transplantation. METHODS: Neural Crest Stem Cells (NCSCs) were isolated from human Dental Pulp (hDP). The experimental rat population was divided into four groups (n = 6/24). Their behavioral motility was scored regularly. After 4-weeks, rats were sacrificed, and their spinal cords were examined for Green Fluorescent Protein (GFP) labeled hDP-NCSCs by immunofluorescence (IF) staining. RESULTS: In early post-injury (p.i) period, the ultrastructure of spinal cord tissue was preserved in Group 4. The majority of cells forming the ependymal region around the central canal were found to be hDP-NCSCs. While the grey-and-white-matter around the ependymal region was composed of e.g. GFP cells, with astrocytic-like appearance. The scores showed significant motor recovery in hind limb functions in Group 4. However, no obvious change was observed in other groups. CONCLUSION: Cells e.g., mesenchymal (Vimentin+) which express GFP+ cells in the gray-and-white-matter around the ependymal region could indicate the potential to self-renewal and plasticity. Thus, transplantation of hDP-NCSCs might be an effective strategy to improve functional recovery following spinal cord trauma (Fig. 10, Ref. 32).

Mesenchymal stem cells increase antioxidant capacity in intestinal ischemia/reperfusion damage.

BACKGROUND: Mesenchymal stem cells (MSCs) may have beneficial effects in reversing intestinal damage resulting from circulatory disorders. The hypothesis of this study is that MSCs increase antioxidant capacity of small bowel tissue following intestinal ischemia reperfusion (I/R) damage. METHODS: A total of 100 rats were used for the control group and three experimental groups, as follows: the sham control, local MSC, and systemic MSC groups. Each group consisted of 10 animals on days 1, 4, and 7 of the experiment. Ischemia was established by clamping the superior mesenteric artery (SMA) for 45min; following this, reperfusion was carried out for 1, 4, and 7days in all groups. In the local and systemic groups, MSCs were administered intravenously and locally just after the ischemia, and they were investigated after 1, 4, and 7days. The superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (Gpx) activities, as well as malondialdehyde (MDA) and total protein levels, were measured. Histopathological analysis was performed using light and electron microscopy. The indicators of proliferation from the effects of anti- and pro-inflammatory cytokines were evaluated using immunohistochemistry. RESULTS: MDA was increased (P<0.05) in the sham control group and decreased (P<0.05) in the MSC groups. SOD, CAT, and Gpx were decreased in the local MSC group (P<0.05). The highest level of amelioration was observed on day 7 in the local MSC group via light and electron microscopy. It was found that the MSCs arrived at the damaged intestinal wall in the MSC groups immediately after injection. Pro-inflammatory cytokines interleukin-1ß (IL1ß), transforming growth factor-ß1 (TGFß1), tumor necrosis factor-α (TNFα), IL6, MIP2, and MPO decreased (P<0.05), while anti-inflammatory cytokines EP3 and IL1ra increased (p<0.05) in the local and systemic MSC groups. In addition, proliferation indicators, such as PCNA and KI67, increased (P<0.05) in the local and systemic MSC groups. CONCLUSIONS: Parallel to our hypothesis, MSC increases the antioxidant capacity of small bowel tissue after intestinal I/R damage. The MSCs migrated to the reperfused small intestine by homing and reduced oxidative stress via the effects of SOD, CAT, and Gpx, as well as reducing the MDA level; thus, they could increase antioxidant capacity of intestine and have a therapeutic effect on the damaged tissue. We think that this effect was achieved via scavenging of oxygen radicals, suppression of pro-inflammatory cytokines, and increasing the expression of anti-inflammatory cytokines.

Differentiation Potential of Mouse Embryonic Stem Cells into Insulin Producing Cells in Pancreatic Islet Microenvironment.

BACKGROUND: The differentiation capacity of embryonic stem cells (ESCs) has great promise for type-1 diabetes for cellular treatment. Therefore, different strategies have been reported so far for derivation of insulin producing cells (IPCs) from ESCs. Providing similar microenvironmental conditions as in vivo, functional differentiation of stem cells into desired cell types could be obtained in vitro. The aim of the present research was to utilize differentiation potential of ESCs to IPCs by co-culture with mouse pancreatic islets (mPIs) for the first time. METHODS: We present an in-direct differentiation protocol which compared with a conventional differentiation protocol. Novel in-direct co-culture differentiation protocol in which mPIs induced differentiation of ESCs into IPCs was used. This technique was compared with the chemical differentiation protocol that involved supplementing the differentiation media with specific growth factors. We analyzed differentiated cells in both groups by immune labelling, gene expression and protein secretion. RESULTS: IPCs were obtained with in-direct co-culture within 30 days. Differentiated ESCs were found to be positive for IPC specific markers, Pdx1, Insulin, C-peptide, Glut2 and MafA. The results of immunocytochemical and gene expression analysis showed higher differentiation efficiency in co-culture group than chemical differentiation group. These results were confirmed by the response assay to high glucose levels with ELISA for insulin. DISCUSSION: Our findings illustrate the significant effect of co-culture in different stages of differentiation and maturation of ESCs in vitro. We have developed an efficient and easy way to differentiate ESCs into IPCs, which possess similar characters of mature insulin positive cells.

Immunomodulatory properties of pancreatic islet-derived stem cells co-cultured with T cells: Does it contribute to the pathogenesis of type 1 diabetes?

BACKGROUND: Previously, we isolated stem cells from rat pancreatic islets (rPI-SCs) with similar characteristics of bone-marrow derived-mesenchymal stem cells (MSCs). We aimed to investigate the immunomodulatory effects of them on stimulated T-cells. METHODS: Following in vitro co-culturing directly and indirectly, the response of T-cells stimulated by concanavalin-A and immunosuppressive activity of rPI-SCs were evaluated by analysing in terms of cell viability, proliferation and apoptosis, cell cycle, differentiation of Treg, cytokines and some regulatory factors produced from T and SCs. RESULTS: Our results have firstly demonstrated that rPI-SCs like MSCs could regulate stimulated T-cell responses by altering their cell-cycle and cytokine profile, inhibiting the cell proliferation, and inducing the apoptosis and differentiation of Treg. Direct and indirect in vitro co-cultures of rPI-SCs with stimulated T-cells showed immunosuppressive effects. CONCLUSION: Therefore, we are introducing a novel type of stem cell with immunomodulatory properties. On the other hand, it is questionable why PI-SCs cannot protect the insulin producing cells from attacks of autoreactive T-cells in the developing of type1 diabetes. For this purpose, further molecular researches in vitro and in vivo are needed to clarify why PI-SCs may not suppress attacks of autoreactive-immune-cells towards PIs. PI-SCs from diseased people should be compared with pancreas of healthy ones at both genomic and proteomic levels.

Effect of hypothyroidism in the thyroidectomized rats on immunophenotypic characteristics and differentiation capacity of adipose tissue derived stem cells.

INTRODUCTION: Thyroid hormones influence multiple physiological functions, like growth, differentiation, protein synthesis and metabolic rate. The hypothyroid state is a complex hormonal dysfunction rather than a single hormonal defect. The relation between hypothyroidism after thyroidectomy and stem cells is not clear. AIM: This study was designed to investigate the effect of thyroidectomy on the proliferation, telomerase enzyme activities, immunophenotypic properties and differentiation potentials of adipose tissue-derived (AT-) stem cells (SCs). MATERIALS AND METHODS: AT-SCs after 60 and 120 days of thyroidectomized (Tx) rats were compared to normal rats by flow cytometry and immunocytochemistry analyses, and their telomerase activities were estimated. RESULTS: The telomerase activity was found to be positive for AT-SCs of Tx rats of both 60 and 120 days used in this study, but a decrease was noticed in the cells with the long-term exposure to hypothyroidism. This might indicate the decrease in the regenerative ability of the AT-SCs after 120 days of Tx compared to cells after 60 days of Tx. Both cell lines were induced to differentiate into adipogenic, osteogenic and neurogenic cell lineages, but osteogenic marker expression was not detected in the undifferentiated AT-SCs of the Tx rats. Osteogenic differentiation was also failed in stem cells derived from Tx rats, shown by Alizarin red S staining and alkaline phosphates enzyme assays. DISCUSSION: These results suggest that hypothyroidism affected SCs, altered stem cell characteristics, like telomerase activity and loss of in vitro bone formation, but not adipogenic or neurogenic differentiation ability. CONCLUSIONS: Hypothyroidism after Tx affects the osteogenic differentiation capacity of stem cells, which might be one of the factors of bone loss due to postnatal hypothyroidism.

Treatment of ischemic colonic anastomoses with systemic transplanted bone marrow derived mesenchymal stem cells.

BACKGROUND: The aim of the study is to investigate the healing effect of the bone-marrow derived mesenchymal stem cells (BM-MSCs) on ischemic colon anastomosis in systemic application and to recovery the adverse effect of ischemia. MATERIALS AND METHODS: Fourty male Wistar Albino rats weigthing 250-300 g were divided into four equal groups (n=10 Group 1: control; ischemic left colonic anastomoses (4th day); Group 2: control; ischemic left colonic anastomoses (7th day); Group 3: ischemic left colonic anastomoses + systemic transplanted BM-MSCs (4th day); Group 4: ischemic left colonic anastomoses + systemic transplanted BM-MSCs (7th day). BMSCs labelled with bromodeoxyuridine (BrdU) were transplanted into the vena cava. Group 1 and group 3 were killed four days after surgery. In group 2 and group 4 were sacrificed seven days after the surgical procedure. Histopathological features, hydroxyproline levels in the tissue, and anastomotic strength were investigated. RESULTS: There was no mortality all of the groups.The mean bursting pressures of ischemic colonic anastomoses in group 3 were higher than in control group 1 (4th day). We found significantly higher hydroxyproline values in group 3 and were significantly higher in group 4 than in control groups. We investigated the early period of wound healing (4th day and 7th day). When comparing between group 1 and group 3, we found higher levels for all of the histological parameters except inflammation in group 3. On day 7, when comparing between group 2 and group 4, we found higher levels for parameters of necrosis, collagen deposition. CONCLUSIONS: BM-MSCs therapy significantly accelerated all of the healing parameters for ischemic colonic anastomosis except for inflammation on fourth day. On the seventh day, BM-MSCs augmented the levels of the hydroxyproline. Histological parameters, necrosis and collagen deposition were also found to be important for healing of ischemic colonic anastomoses. However, they did not accelerate the others histological parameters especially angiogenesis.

Effects of mesenchymal stem cells in critical size bone defect.

BACKGROUND AND OBJECTIVES: The aim of this study was to compare culture-expanded, bone marrow-derived mesenchymal stem cells (MSCs) and platelet-rich plasma (PRP) loaded to biphasic calcium phosphate (BCP) bone ceramic in the repair of rat calvarial bone. MATERIALS AND METHODS: Critical-size (7 mm dia.) calvarial defects were prepared in the frontal-parietal bones of 90 adult female Sprague-Dawley rats. Rats were randomly divided into 5 groups, according to defect filling, as follows: Group I (n = 21), BCP; Group II (n = 21), BCP+PRP; Group III (n = 21), BCP+MSC; Group IV (n = 21), BCP+PRP+MSC; Group V (n = 6) (control), no treatment. Animals were sacrificed at 2, 8 and 12 weeks postsurgery and bone regeneration was evaluated both histologically and immunohistochemically. RESULTS: Statistically significant differences were observed in bone osteoblastic activity in calvarial defects among the groups (p < 0.05). PRP and MSC used in combination with BCP as a defect filling resulted in greater osteoblastic bone formation activity when compared to the use of BCP alone. CONCLUSIONS: The combination of mesenchymal stem cells, platelet rich plasma and synthetic bone substitute was found to be more effective in inducing new bone formation (osteogenesis) than the use of platelet rich plasma combined with synthetic bone substitute and the use of synthetic bone substitute alone.

Pancreatic islet derived stem cells can express co-stimulatory molecules of antigen-presenting cells.

BACKGROUND: Antigen-presenting cells (APCs) are crucial intermediates in the generation of both innate and specific immune responses. It has long been understood that some APCs are resident in islets in situ as well as after isolation. Our aim was to investigate the presence of molecules involved in antigen presentation in rat pancreatic islet-derived stem cells (PI-SCs). METHODS: We used immunocytochemistry and reverse transcription polymerization chain reaction to study immunophenotypic characteristics; pluripotent-related gene expressions; transcripts coding for antigen-presenting surface proteins CD40, CD80, CD86; and major histocompatibility complex class II in addition to genes with known antiapoptotic functions including mitogen-activated protein kinase-activated protein kinase 2 (MAPKAPK2), tumor necrosis factor alpha-induced protein 3 (TNFAIP3) interacting protein 1 (TNIP1) and BCL3 of the PI-SCs. RESULTS: Rat PI-SCs were negative for CD45 as demonstrated by flow cytometry and for CD31, CD34, and CD71 as demonstrated by immunocytochemistry. Therefore, there was no evidence of hematopoietic precursors in the cultures. OCT4, SOX2, and REX1 were expressed by rat PI-SCs. We determined the expression of genes for antigen-presenting surface proteins CD40 and CD80, and genes with known antiapoptotic functions including MAPKAPK2, TNIP1 and BCL3, besides the surface protein, CD80, by flow cytometry. CONCLUSION: Expression of these genes by rat PI-SCs implied that they could be involved in the regulation of immunity in islets, highlighting the influence of protective role-playing antiapoptotic mechanisms on pancreatic islet cells. This study offers the potential to understand the molecular mechanisms of a devastating disease, type-1 diabetes mellitus.

Protection of rat pancreatic islet function and viability by coculture with rat bone marrow-derived mesenchymal stem cells.

The maintenance of viable and functional islets is critical in successful pancreatic islet transplantation from cadaveric sources. During the isolation procedure, islets are exposed to a number of insults including ischemia, oxidative stress and cytokine injury that cause a reduction in the recovered viable islet mass. A novel approach was designed in which streptozotocin (STZ)-damaged rat pancreatic islets (rPIs) were indirectly cocultured with rat bone marrow-derived mesenchymal stem cells (rBM-MSCs) to maintain survival of the cultured rPIs. The results indicated that islets cocultured with rBM-MSCs secreted an increased level of insulin after 14 days, whereas non-cocultured islets gradually deteriorated and cell death occurred. The cocultivation of rBM-MSCs with islets and STZ-damaged islets showed the expression of IL6 and transforming growth factor-ß1 in the culture medium, besides the expression of the antiapoptotic genes (Mapkapk2, Tnip1 and Bcl3), implying the cytoprotective, anti-inflammatory and antiapoptotic effects of rBM-SCs through paracrine actions.

Leptin expression in the testicular tissue of fertile and infertile men.

There have been several studies about the presence of leptin in serum and testicular tissue, and none of them compares the leptin expression in the testicular tissue of fertile and infertile men. We assessed the presence of leptin expression in the testicular tissue of fertile and infertile men. 20 azoospermic infertile men were included in the study. All patients underwent testicular sperm extraction (TESE) for ICSI. For the detection of leptin, the immunohistochemistry was carried out. Intensity of immunohistochemical staining was subjectively estimated and expressed as negative (-), weak positive (+), intermediate positive (++) and strong positive (+++). Testicular tissues of 5 fertile patients, aged 50-60 years, was stained with leptin for control group. Mann-Whitney U test was used as the statistical method. There was no statistically significant difference in leptin staining between infertile patients and control group (p < 0.05). Leptin staining in tubuli seminiferi and Leydig cells were generally equal or Leydig cells were stained (+) much. This difference was not statistically significant. We found that there is leptin staining in Leydig cells and tubuli seminiferi. There is no difference in normal and infertile men for leptin staining properties in testicular tissue. This condition suggests that the effect of leptin on reproductive functions originates from a systemic effect related to central neuroendocrine system, androgen levels or spermatogenic existence rather than its direct effect on testicular tissue.

Effect of thyroidectomy on the histology of rat sublingual gland.

This study was carried out to investigate the effect of thyroidectomy on the histology of rat sublingual gland. Twenty-eight male Wistar albino rats, aged 4 weeks and weighing between 45-55 g, were used. The rats were divided into two experimental groups (control and thyroidectomy), each containing 14 animals. Total thyroidectomy of rats was performed under ether anesthesia in thyroidectomy group. The rats in the control group were sham operated without having the thyroidectomy. Seven rats randomly selected from both groups were fixed using the perfusion fixation technique 2 and 6 weeks after thyroidectomy, and their sublingual glands were harvested for histological investigation. No histological difference was observed between the two groups 2 weeks after thyroidectomy. However, 6 weeks after thyroidectomy considerable cytoplasmic vacuolization of the epithelial cells of the mucous tubules was seen in the thyroidectomy group compared to the controls. Enlargement of mucous tubules was also observed, and the lumina in most of the tubules was quite dilated. In the stroma surrounding the parenchymal tissues, increased lipid tissue mass was observed. In addition, increased connective tissue mass and mononuclear cell infiltrations were evident. Furthermore, the number of mast cells was significantly higher in the thyroidectomy group than in the controls 6 weeks after thyroidectomy. It was concluded that the thyroid gland and hormones might have an influence on the histology of the sublingual gland.

Splenectomy reduces remote organ damage after intestinal ischaemia-reperfusion injury.

PURPOSE: In this study, we aimed to reduce mononuclear phagocytic system (MFS) cells with splenectomy and investigate its preventive effects on lung, liver, and kidney ultrastructure and free radical generation after intestinal ischaemia-reperfusion (IIR). METHOD: Forty adult male albino Wistar rats were randomly divided into four groups as sham laparatomy (SL), splenectomy + sham laparatomy (SSL), intestinal ischaemia-reperfusion (IIR), and splenectomy + intestinal ischaemia-reperfusion (SIIR). One hour of mesenteric ischaemia and four hours of reperfusion were applied. Splenectomy was performed just before reperfusing the intestine. Serum levels of malonedialdehyde (MDA) was measured, and tissue samples obtained from the lung, liver, and kidneys were fixed in 2.5% glutaraldehyde for electron microscopy. RESULTS: Lung, liver, and kidney ultrastructures were normal in both groups of SL and SSL. In the IIR group, type 2 pneumocytes showed lamellar body degeneration, dilation of smooth endoplasmic reticulum, and thickening of the basal lamina. Hepatocytes showed dilation of the rough endoplasmic reticulum, mitochondrial degeneration, and cytoplasmic lipid droplets. The glomerular basement membrane was thickened and the endothelial cells showed discontinuity. The foot processes of the podocytes and microvilli of the proximal tubule cells had also disappeared in the kidney. Splenectomy attenuated these ultrastructural changes in the SIIR group. In the IIR group, serum MDA level was significantly increased to 171.7 +/- 6.7 nmol/ml (p < 0.05). Splenectomy significantly reduced serum MDA level to 87.8 +/- 2.5 nmol/ml in the SIIR group (p < 0.05). CONCLUSIONS: Splenectomy attenuated degenerative findings encountered in lung, liver, and kidney ultrastructure after IIR. Splenectomy also significantly decreased serum levels of MDA. The possible role of splenectomy is to reduce the MFS cells, which play an important role in the remote organ injury after intestinal reperfusion damage.

Ischemia, whether from ligation or torsion, causes ultrastructural changes on the contralateral testis.

OBJECTIVE: Unilateral testicular torsion results with a decrease in contralateral testicular blood flow caused by a reflexive sympathetic response. The aim of this study was to investigate whether twisting of the spermatic cord, or testicular ischemia without twisting, activates this reflex mechanism and causes ultrastructural changes in the contralateral side. MATERIALS AND METHODS: Thirty adult male albino Wistar rats were randomly allocated into three groups of sham, torsion, and ligation. Right testes were twisted 720 degrees counterclockwise in the torsion group. Right spermatic cords were ligated permanently with a silk suture including the vas deferens in the ligation group. After 24 h of testicular ischemia, contralateral left testes were removed for electron microscopic evaluation. RESULTS: Contralateral testes showed similar ultrastructural changes in the torsion and ligation groups. The fibrous tunica propria enveloping the seminiferous tubule was thickened due to increased collagen fibers. The basal lamina was continuous but thickened and showed several foldings. The gap between basal lamina and the germ cells was increased because of collagen fibers. Leydig cells showed mitochondrial degeneration with the loss of its cristae. Leydig cells lost their contact with its neighborhood cells in some areas, and these gaps were filled with collagen fibers. Germ cells showed dilated cisternae of smooth endoplasmic reticulum, cytoplasmic electron-dense bodies and clear regions. CONCLUSIONS: Similar electron microscopic findings observed in the torsion and ligation groups indicate that testicular ischemia rather than twisting of the spermatic cord is responsible for the ultrastructural changes in the contralateral side.

Nephrotoxicity in rats induced by chlorpryfos-ethyl and ameliorating effects of antioxidants.

Nephrotoxicity induced by chlorpyrifos-ethyl (CE) and ameliorating effects of melatonin and vitamin E plus vitamin C were evaluated in rats exposed to CE. Experimental groups were as follows: control (C), CE treated (CE), vitamin E plus vitamin C treated (Vit), melatonin treated (Mel), vitamin E plus vitamin C plus CE treated (Vit+CE), and melatonin plus CE treated (Mel+CE). The rats in the CE, Vit+CE and Mel+CE groups were administered orally with CE in two equal doses of 41 mg/kg body weight (0.25 LD50). Melatonin and vitamins E and C were administrated intramuscularly at the doses of 10, 150 and 200 mg/kg, respectively. The levels of thiobarbituric acid reactive substance (TBARS) and antioxidant potential (AOP), and the activities of glutathione peroxidase (GSH-Px), catalase (CAT) and superoxide dismutase (SOD) were studied in the homogenates of kidney tissue. There were no significant differences in the activities of SOD and CAT between the experimental groups. The level of TBARS increased significantly (P<0.05) while AOP decreased significantly (P<0.05) in the CE group compared with the C group. GSH-Px activity was significantly (P<0.05) lower in the CE group and higher in the melatonin group than the control group. Histopathological changes were found in the kidney tissue of rats treated with CE. These were infiltration in mononuclear cells at perivascular and peritubular areas, hydropic degenerations in tubule epithelium and glomerular sclerosis. The severity of the lesions was reduced by administration of vitamins and melatonin. These results suggest that CE increases lipid peroxidation and decreases AOP by increasing oxidative stress, and that high doses of melatonin and a combination of vitamin E plus vitamin C considerably reduce the toxic effect of CE on kidney tissue of rats.

Effect of diclofenac sodium administration during pregnancy in the postnatal period.

OBJECTIVE: The present study aimed to investigate the possible postnatal effects on the liver, kidney and testicular tissues of the offspring of rats given diclofenac sodium (DS) during pregnancy. METHODS: At the beginning of the experiment, 80 rats (20 males and 60 females) were raised together for mating purposes. At the end, 50 pregnant rats were obtained and used as the experimental subjects. All pregnant rats were divided into 2 groups, each with 25 rats. The rats of the control group received physiological serum, 1 cm3/kg live weight per day, and the rats of the treatment group were injected with DS, 1 mg/kg live weight per day from the 5th to the 20th day of pregnancy. Four weeks after birth, tissue samples were obtained under anesthesia by perfusion fixation from a total of 40 offspring, 20 (10 males, 10 females) from the control group and 20 (10 males 10 females) from the DS group. Paraffin sections were dyed with hematoxylin eosin and examined under light microscopy. RESULTS: The gestation period was significantly prolonged with DS-treated rats (p < 0.001). A moderate significant enlargement in the periportal area (p < 0.05), sinusoidal dilatation (p < 0.001), bile duct proliferation (p < 0.001), pyknosis in the nucleus of hepatocytes, and vacuolar degeneration in parenchymal cells (p < 0.001) were observed in DS-treated rats. Morphological changes in the liver were found to be similar both in female and male rats. Under light microscopy a similar morphological structure was observed in the kidney and testicular tissues of both the DS-treated and control rats. CONCLUSION: Significant morphological changes were observed in the livers of the offspring whose parents had been treated with DS. No significant differences were observed in liver morphology between the female and male offspring. There were no significant effects of DS on the morphology of the kidney and testis in all offspring.