Melatonin in preservation solutions prevents ischemic injury in rat kidneys.

Transplantation is lifesaving and the most effective treatment for end-stage organ failure. The transplantation success depends on the functional preservation of organs prior to transplantation. Currently, the University of Wisconsin (UW) and histidine-tryptophan-ketoglutarate (HTK) are the most commonly used preservation solutions. Despite intensive efforts, the functional preservation of solid organs prior to transplantation is limited to hours. In this study, we modified the UW solution containing components from both the UW and HTK solutions and analyzed their tissue-protective effect against ischemic injury. The composition of the UW solution was changed by reducing hydroxyethyl starch concentration and adding Histidine/Histidine-HCl which is the main component of HTK solution. Additionally, the preservation solutions were supplemented with melatonin and glucosamine. The protective effects of the preservation solutions were assessed by biochemical and microscopical analysis at 2, 10, 24, and 72 h after preserving the rat kidneys with static cold storage. Lactate dehydrogenase (LDH) activity in preservation solutions was measured at 2, 10, 24, and 72. It was not detectable at 2 h of preservation in all groups and 10 h of preservation in modified UW+melatonin (mUW-m) and modified UW+glucosamine (mUW-g) groups. At the 72nd hour, the lowest LDH activity (0.91 IU/g (0.63-1.17)) was measured in the mUW-m group. In comparison to the UW group, histopathological damage score was low in modified UW (mUW), mUW-m, and mUW-g groups at 10, 24, and 72 hours. The mUW-m solution at low temperature was an effective and suitable solution to protect renal tissue for up to 72 h.

The Protective Effects of Thymosin-ß-4 in a Rat Model of Ischemic Acute Kidney Injury.

BACKGROUND: Despite the progress in the treatment of acute kidney injury (AKI), current curative approaches fail to provide adequate treatment. In this study, we aimed to investigate the possible protective effects of thymosin-ß-4(Tß4) on an ischemic AKI model in rats. METHODS: Rats were randomly assigned into four groups (n = 8/group): The control group (sham-operated), the ischemia-reperfusion (I/R) group; renal ischemia (90 min) by infrarenal abdominal aortic occlusion followed by reperfusion (3 h), the Tß4 + I/R group; treated with Tß4 before I/R, and the I/Tß4/R group; treated with Tß4 just before reperfusion. Besides renal function determination (creatinine (Cr) and blood urea nitrogen (BUN)); histological evaluation was also conducted. Renal tissue caspase-9, matrix metalloproteinase (MMP-9) activities, and hyaluronan levels were measured. Additionally, renal tissue oxidative stress (lipid hydroperoxide, malondialdehyde, superoxide dismutase, glutathione, pro-oxidant-antioxidant balance, ferric reducing antioxidant power, nitric oxide), inflammation (tumor necrosis factor-α, interleukin-1ß, interleukin-6, nuclear factor-κß) were evaluated. RESULTS: I/R increased the level of caspase-9, MMP-9 activity, and hyaluronan (p < 0.001) and these were significantly decreased in both Tß4 groups. Moreover, I/R led to increases in oxidative stress and inflammation parameters (p < 0.001) while the levels of antioxidants were decreased. Nevertheless, Tß4 in both groups were able to restore oxidative stress and inflammation parameters. Furthermore, Tß4 attenuated histologic injury caused by I/R (p < 0.01) and diminished serum urea-creatinine levels (p < 0.001). CONCLUSION: These results suggest that Tß4 has significant improving effects in ischemic acute kidney injury. This beneficial effect might be a result of the inhibition of extracellular matrix remodeling and apoptosis cascade via modulation in renal redox status and inflammation.

Opuntia ficus indica Fruits Ameliorate Cisplatin-Induced Nephrotoxicity in Mice.

This study aims to determine the potential renal protective effects of Opuntia ficus-indica (L.) Miller (OFI) fruits against cisplatin-induced nephrotoxicity in mice. The antioxidant activity of OFI methanol extract was calculated by 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2'-azino-bis-3-ethylbenzthiazoline-6-sulfonic acid (ABTS) free radical scavenging assays. Furthermore, the LC-mass spectroscopy (MS) analysis of the OFI fruit extract was carried out. Mice were treated with OFI extract (250 mg/kg) for 10 d and injected with a single dose of cisplatin (20 mg/kg) on the 7th day. The blood samples were collected to measure blood urea nitrogen (BUN) and serum creatinine level on the 10th day. Their kidneys were removed for histopathological examination. The renal morphological alterations were assessed through the mesangial matrix index and transmission electron microscopy (TEM). The OFI fruit extract showed significant in vitro antioxidant activity. In further, it was revealed that the cisplatin-induced nephrotoxicity in mice was ameliorated; this outcome was supported by both histological examination results and the depicted reduced levels of BUN and serum creatinine. The potent antioxidant compounds which were detected in the extract of OFI fruits such as myricetin, quercetin, luteolin might be responsible for the observed renoprotective effect. The results clarified that the OFI fruit extract could ameliorate cisplatin-induced renal toxicity in mice via including antioxidant and renoprotective compounds.

Dilated Minute Chambers in Laryngeal Vocal Fold Polyps: Histopathological and Ultrastructural Features.

In Reinke's space of human vocal fold, type III collagen forms a three dimensional network and this contains numerous minute chambers in between these fibers. These compartments are occupied by glycosaminoglycans and glycoproteins. In laryngeal fold lesions, such as Reinke's edema and vocal fold polyps, proteoglycan (PG)/hyaluronic acid (HA) components of extracellular matrix increased. We investigated the size and quantity of the minute chambers within Reinke's space, filled with PG/HA with the aid of transmission electron microscopy. Eight vocal fold polyps and 10 mucosal biopsies (as control group) were all evaluated by light microscopy and electron microscopy. We detected that PG/HA in extracellular matrix had been increased in vocal fold lesions when compared with control group, by Alcian Blue-pH 2.5 stain. The mean volume of the chambers in Reinke's space of normal larynx was measured as 0.040233 µm2 whereas the mean volume of these chambers in vocal fold polyps was measured as 6.420221 µm2. The difference between the volumes of these chambers in vocal fold polyps and in control group was statistically significant (P = 0.001). Within these chambers PG/HA were found and PG/HA filling these chambers were increased in vocal fold polyps. We think proteoglycan and glycosaminoglycans, especially HA, play an important role in determining biochemical properties of vocal fold lesions.

Anti-inflammatory and ultrastructural effects of Turkish propolis in a rat model of endotoxin-induced uveitis.

INTRODUCTION: Experimental animal models of acute uveitis, an inflammatory eye disease, can be established via endotoxin-induced inflammation. Propolis, a natural substance collected by honeybees from buds and tree exudates, has antioxidant, antibacterial, antiviral, and anti-inflammatory effects. We investigated the effects of propolis, obtained from the Sakarya province of Turkey, on endotoxin-induced uveitis using immunohistochemical, ultrastructural, and biochemical approaches. MATERIAL AND METHODS: Male Wistar albino rats (n = 6/group) received intraperitoneal (ip) lipopolysaccharide (LPS) endotoxin (150 µg/kg) followed by aqueous extract of propolis (50 mg/kg ip) or vehicle; two additional groups received either saline (control) or propolis only. After 24 h, aqueous humor (AH) was collected from both eyes of each animal for analysis of tumor necrosis factor-α (TNF-α) and hypoxia-inducible factor-1α (HIF-1α). Right eyeballs were paraffin-embedded for immunohistochemical staining of nuclear factor κB (NF-κB)/p65 and left eyeballs were araldite-embedded for ultrastructural analysis. RESULTS: Treatment of LPS-induced uveitis with propolis significantly reduced ciliary body NF-κB/p65 immunoreactivity and AH levels of HIF-1α and TNF-α. Ultrastructural analysis showed fewer vacuoles and reduced mitochondrial degeneration in the retinal pigment epithelium, as compared to the uveitis group. The intercellular spaces of the inner nuclear layer and outer limiting membrane were comparable with those of the control group; no polymorphonuclear cells or stasis was observed in intravascular or extravascular spaces. CONCLUSIONS: This is the first report demonstrating an anti-inflammatory effect of Turkish propolis in a rat model of LPS-induced acute uveitis, suggesting a therapeutic potential of propolis for the treatment of inflammatory ophthalmic diseases.

Histologic Findings of Corneal Buttons in Decompensated Corneas With Toxic Anterior Segment Syndrome After Cataract Surgery.

PURPOSE: To report the histologic findings of penetrating keratoplasty buttons in decompensated corneas with toxic anterior segment syndrome (TASS) after a cataract surgery is performed. METHODS: We evaluated the histologic findings of 16 corneal buttons of 16 patients who exhibited decompensation findings because of TASS by means of light microscopy. The patients were classified into 3 groups: The first group consisted of 5 corneal buttons with mild symptoms in which the central corneal thicknesses (CCTs) were ≤650 µm, and the visual acuities (VAs) were ≥0.1. The second group consisted of 7 corneal buttons that exhibited moderate symptoms in which the CCTs were between 650 and 750 µm and the VAs were between 0.1 and 0.03. The third group consisted of 4 corneal buttons that had severe symptoms in which the CCTs were ≥750 µm and the VAs were ≤0.03. RESULTS: Light microscopy showed endothelial cell loss, vacuolated and thinned epithelial cell layers, disturbed collagen bonds, and Descemet membrane invaginations in patients in group I. Group II corneal buttons exhibited inflammatory cells (lymphocytes) and extended intercellular space between the epithelial cells, wrinkled Bowman membrane separated from the stroma in some local areas, stromal edema, and early vascularization. In group III, endothelial and epithelial cell layer loss, wrinkled Descemet and Bowman membranes, inflammatory cells, and structurally disturbed collagen bonds located beneath the Bowman membrane, and a greater amount of vascularization in the area of inflammation were observed. CONCLUSIONS: The results of the histologic evaluation of the decompensated corneas caused by the TASS are compatible with the clinical severity of the disease. In mild cases, the histologic findings were insignificant; however, when the clinical situation deteriorated, histologic findings became increasingly worse.

Experimentally induced puromycine aminonucleoside nephrosis (PAN) in rats: evaluation of angiogenic protein platelet-derived endothelial cell growth factor (PD-ECGF) expression in glomeruli.

BACKGROUND: In experimentally induced puromycine aminonucleoside nephrosis (PAN) animal models, nephrotic syndrome with minimal change disease and focal and segmental sclerosis-like nephritis similar to that in human is demonstrated; however, the real mechanism of PAN is not yet elucidated. Platelet derived endothelial cell growth factor (PD-ECGF), an endothelial mitogen protein, is believed to take part in microvessel formation and in stimulation of angiogenesis and its expression has not been totally demonstrated in PAN rats yet. In this study, we aimed to examine PD-ECGF expression in acute and chronic PAN induced in rats and find out the association between its expression and the stages of angiogenesis in kidney. METHODS: For the experiment, twenty-four Male Wistar Albino rats were used and divided into four groups; control group (n = 6), pre-proteinuria group (n = 6), acute group (n = 6) and chronic group (n = 6). We compared statistically all data by One-way ANOVA Test followed by Dunn Multiple Comparison Test. RESULTS: Proteinurea levels in control and pre-proteinuria groups were not statistically different; however, it was remarkably higher in the acute nephrosis group and significantly greater in the chronic nephrosis group than control group (p < 0.0025). In pre-proteinuria group, the serum albumin and creatinine clearances also did not significantly differ from the control group. On the other hand, in the acute and chronic nephrosis groups, serum albumin and creatinine clearances progressively decreased (p < 0.05). In our immunohistochemical studies, we showed elevated PD-ECGF expression in glomeruli of acute and chronic PAN rats. Microscopic and ultrastructural appearances of the glomeruli of acute and chronic PAN showed various sequential steps of angiogenesis, macrophages and immature capillaries with primitive lumens and apoptotic endothelial cells in the increased mesangial matrix. CONCLUSIONS: It is reported that acute and chronic PAN progressively increase PD-ECGF expression and following induction of angiogenesis in the affected glomeruli.

Corneal tissue welding with infrared laser irradiation after clear corneal incision.

PURPOSE: The aim of this study was to investigate the potential of infrared lasers for corneal welding to seal corneal cuts done in an experimental animal model. MATERIALS AND METHODS: Full-thickness corneal cuts on freshly enucleated bovine eyes were irradiated with infrared (809-nm diode, 980-nm diode, 1070-nm YLF, and 1980-nm Tm:YAP) lasers to get immediate laser welding. An 809-nm laser was used with the topical application of indocyanine green to enhance the photothermal interaction at the weld site. In total, 60 bovine eyes were used in this study; 40 eyes were used in the first part of the study for the determination of optimal welding parameters (15 eyes were excluded because of macroscopic carbonization, opacification, or corneal shrinkage; 2 eyes were used for control), and 20 eyes were used for further investigation of more promising lasers (YLF and Tm:YAP). Laser wavelength, irradiating power, exposure time, and spot size were the dose parameters, and optimal dose for immediate closure with minimal thermal damage was estimated through histological examination of welded samples. RESULTS: In the first part of the study, results showed that none of the applications was satisfactory. Full-thickness success rates were 28% (2 of 7) for 809-nm and for 980-nm diode lasers and 67% (2 of 3) for 1070-nm YLF and (4 of 6) for 1980-nm Tm:YAP lasers. In the second part of the study, YLF and Tm:YAP lasers were investigated with bigger sample size. Results were not conclusive but promising again. Five corneal incisions were full-thickness welded out of 10 corneas with 1070-nm laser, and 4 corneal incisions were partially welded out of 10 corneas with 1980-nm laser in the second part of the study. CONCLUSIONS: Results showed that noteworthy corneal welding could be obtained with 1070-nm YLF laser and 1980-nm Tm:YAP laser wavelengths. Furthermore, in vitro and in vivo studies will shed light on the potential usage of corneal laser welding technique.

Protective effect of a potent antioxidant, pomegranate juice, in the kidney of rats with nephrolithiasis induced by ethylene glycol.

PURPOSE: We aimed to study the protective effects of pomegranate juice (PJ) on ethylene glycol (EG)-induced crystal deposition in renal tubules, renal toxicity, and inducible nitric oxide synthase (iNOS) and nuclear factor-kappaB activities in rat kidneys. MATERIALS AND METHODS: Fifty-six rats were divided into four equal groups: Control, EG, EG + 50 microL PJ/d (PJ50), and EG + 100 microL PJ/d (PJ100). Rats were sacrified on days 10 and 45. Tissue sections were evaluated under light and polarized microscopy for the presence and degree of crystal deposition and toxicity in the kidneys. Crude extracts of the cortex were used to determine reduced gluthatione (GSH), nitric oxide (NO), and malondialdehyde (MDA) levels. RESULTS: In the EG group, crystal depositions were more evident and mild crystalization was observed in proximal tubules on day 10; severe crystalization and granulovacuolar epithelial cell degeneration were observed on day 45. There was limited or no crystal formation in the EG + PJ-given groups. There were completely normal renal and tubular structures in the control group. There was no significant difference between the four groups in serum levels of sodium, potassium, blood urea nitrogen, and creatinine in any sampling time. Hyperoxaluria, a marked increase in MDA and NO levels, and decrease of GSH were observed in the EG-given groups compared with the others. There were marked iNOS and p65 expressions in only the EG-given rats compared with control and PJ groups, immunohistochemically. CONCLUSION: This experiment shows the protective effect of PJ in the EG-induced crystal depositions in renal tubules.

Rapid communication: protective effect of a nuclear factor kappaB inhibitor, pyrolidium dithiocarbamate, in the kidney of rats with nephrolithiasis induced by ethylene glycol.

PURPOSE: To study the protective effects of a selective nuclear factor kappa B (NF-kappaB) inhibitor, pyrolidium dithiocarbamate (PDTC), on ethylene glycol-induced crystal deposition in the renal tubules, renal toxicity, as well as inducible nitric oxide synthase (iNOS) and NF-kappaB activities in rat kidneys. MATERIALS AND METHODS: Rats were divided into three equal groups: control, ethylene glycol-treated (EG), and ethylene glycol + PDTC treated (EG+PDTC). Rats were sacrificed on day 7, 15, or 45, and tissue sections were evaluated under light and transmission electron microscopy for the presence and degree of crystal deposition and toxicity in the kidneys. The iNOS and NF-kappaB activity were evaluated immunohistochemically, with p65 being stained to define NF-kappaB activity. Crude extracts of the cortex were used to determine reduced glutathione (GSH), nitric oxide (NO), and malondialdehyde (MDA) concentrations. RESULTS: Crystal depositions were more evident in the proximal tubules on day 7 in the EG than in the other groups. Mild crystallization was observed on day 15, and severe crystallization and granulovacuolar epithelial-cell degeneration were observed on day 45. There was limited or no crystal formation in the EG+PDTC group and completely normal renal and tubular structures in the control group. Whereas ethylene glycol administration stimulated iNOS and NF-kappaB/p65 activity in renal tubules, PDTC inhibited it. Rats given only vehicle demonstrated no significant alterations. Hyperoxaluria, a marked increase in MDA and NO concentrations, and a decrease in GSH were observed in the EG group. CONCLUSION: This experiment has shown the role of transcription factors, NF-kappaB, and iNOS in ethylene glycol-induced crystal depositions in renal tubules.