Naringin attenuates oxaliplatin-induced nephrotoxicity and hepatotoxicity: A molecular, biochemical, and histopathological approach in a rat model.

Oxaliplatin (OXL) is a significant therapy agent for the worldwide increase in cancer cases. Naringin (4',5,7-trihydroxy flavonon 7-rhamnoglucoside, NRG) has a wide range of biological and pharmacological activities, including antioxidant and anti-inflammatory potentials. This research aimed to investigate NRG activity in OXL-induced hepatorenal toxicity. Accordingly, OXL (4 mg/kg b.w.) in 5% glucose was injected intraperitoneally on the first, second, fifth, and sixth days, and NRG (50 and 100 mg/kg b.w.) was given orally 30 min before to treatment. Biochemical, genetic, and histological methods were utilized to investigate the function tests, oxidant/antioxidant status, inflammation, apoptosis, and endoplasmic reticulum (ER) stress pathways in kidney and liver tissues. Administration of NRG demonstrated an antioxidant effect by increasing the activities of OXL-induced reduced antioxidant enzymes (superoxide dismutase, catalase, and glutathione peroxidase) and decreasing the elevated lipid peroxidation parameter malondialdehyde levels. Nuclear factor-κB, tumor necrosis factor-α, interleukin-1ß, and inducible nitric oxide synthase levels increased in OXL administered groups but reduced in NRG-treated groups. In the OXL-administered groups, NRG reduced the apoptosis-inducing factors Caspase-3 and B-cell lymphoma 2 (Bcl-2)-associated X protein levels, while elevating the antiapoptotic factor Bcl-2 levels. OXL triggered prolonged ER stress by increasing the levels of ER stress parameters activating transcription factor 6, protein kinase R-like ER kinase, inositol-requiring enzyme 1α, and glucose-regulated protein 78. Therefore, with the NRG administration, this activity was reduced and the ER stress level decreased. Taken together, it was found that OXL induced toxicity by increasing the levels of urea and creatinine, alanine transaminase, aspartate aminotransferase, and alkaline phosphatase activities, inflammation, apoptosis, ER stress, and oxidants in the liver and kidney tissue, and NRG had a protective effect by reversing the deterioration in these pathways.

Positive effect of ulnar nerve fascicle transfer to musculocutaneous nerve seeded with allogeneic adipose tissue derived stem cells on nerve regeneration for repairing upper brachial plexus injury in a rat model: A preliminary study.

BACKGROUND: Traumatic peripheral nerve injury, with an annual incidence reported to be approximately 13-23 per 100,000 people, is a serious clinical condition that can often lead to significant functional impairment and permanent disability. Although nerve transfer has become increasingly popular in the treatment of brachial plexus injuries, satisfactory results cannot be obtained even with total nerve root transfer, especially after serious injuries. To overcome this problem, we hypothesize that the application of stem cells in conjunction with nerve transfer procedures may be a viable alternative to more aggressive treatments that do not result in adequate improvement. Similarly, some preliminary studies have shown that adipose stem cells combined with acellular nerve allograft provide promising results in the repair of brachial plexus injury. The purpose of this study was to assess the efficacy of combining adipose-derived stem cells with nerve transfer procedure in a rat brachial plexus injury model. METHODS: Twenty female Wistar rats weighing 300-350 g and aged 8-10 weeks were randomly divided into two groups: a nerve transfer group (NT group) and a nerve transfer combined adipose stem cell group (NT and ASC group). The upper brachial plexus injury model was established by gently avulsing the C5-C6 roots from the spinal cord with microforceps. A nerve transfer from the ulnar nerve to the musculocutaneous nerve (Oberlin procedure) was performed with or without seeded allogeneic adipose tissue-derived stem cells. Adipose tissue-derived stem cells at a rate of 2 × 106 cells were injected locally to the surface of the nerve transfer area with a 23-gauge needle. Immunohistochemistry (S100 and PGP 9.5 antibodies) and electrophysiological data were used to evaluate the effect of nerve repair 12 weeks after surgery. RESULTS: The mean latency was significantly longer in the NT group (2.0 ± 0.0 ms, 95% CI: 1.96-2.06) than in the NT and ASC group (1.7 ± 0.0 ms, 95% CI: 1.7-1.7) (p < .001). The mean peak value was higher in the NT group (1.7 ± 0.0 mV, 95% CI: 1.7-1.7) than in the NT and ASC group (1.7 ± 0.3 mV, 95% CI: 1.6-1.9) with no significant difference (p = .61). Although S100 and PGP 9.5 positive areas were observed in higher amounts in the NT and ASC group compared to the NT group, the differences were not statistically significant (p = .26 and .08, respectively). CONCLUSIONS: This study conducted on rats provides preliminary evidence that adipose-derived stem cells may have a positive effect on nerve transfer for the treatment of brachial plexus injury. Further studies with larger sample sizes and longer follow-up periods are needed to confirm these findings.

Ozone Prevents Cochlear Damage From Ischemia-Reperfusion Injury in Guinea Pigs.

The cochlea is an end organ, which is metabolically dependent on a nutrient and oxygen supply to maintain its normal physiological function. Cochlear ischemia and reperfusion (IR) injury is considered one of the most important causes of human idiopathic sudden sensorineural hearing loss. The aim of the present study was to study the efficacy of ozone therapy against cochlear damage caused by IR injury and to investigate the potential clinical use of this treatment for sudden deafness. Twenty-eight guinea pigs were randomized into four groups. The sham group (S) (n = 7) was administered physiological saline intraperitoneally (i.p.) for 7 days. The ozone group (O) (n = 7) was administered 1 mg/kg of ozone i.p. for 7 days. In the IR + O group (n = 7), 1 mg/kg of ozone was administered i.p. for 7 days before IR injury. On the eighth day, the IR + O group was subjected to cochlear ischemia for 15 min by occluding the bilateral vertebral artery and vein with a nontraumatic clamp and then reperfusion for 2 h. The IR group was subjected to cochlear IR injury. After the IR procedure, the guinea pigs were sacrificed on the same day. In a general histological evaluation, cochlear and spiral ganglionic tissues were examined with a light microscope, and apoptotic cells were counted by terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) staining. The apoptotic index (AI) was then calculated. Blood samples were sent for analyses of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), catalase, malondialdehyde (MDA), the total oxidant score (TOS), and total antioxidant capacity (TAC). Data were evaluated statistically using the Kruskal-Wallis test. The AI was highest in the IR group. The AI of the IR + O group was lower than that of the IR group. The biochemical antioxidant parameters SOD and GSH-Px and the TAC values were highest in the O group and lowest in the IR group. The MDA level and TOS were highest in the IR group and lowest in the O group. Controlled ozone administration stimulated endogenous antioxidant defense systems, thereby helping the body to combat IR injury. Although this study revealed a statistically significant decrease in cochlear IR damage following ozone therapy, further studies will be necessary to explain the protective mechanisms of ozone therapy in cochlear IR injury.

Antiangiogenic effect of itraconazole on corneal neovascularization: a pilot experimental investigation.

PURPOSE: To investigate the antiangiogenic effect of itraconazole for the prevention of experimentally induced corneal neovascularization and whether the efficacy depends on the route of administration. MATERIALS AND METHODS: Thirty-six rats were randomly divided into 6 groups with 6 rats in each group. Chemical cauterization of the cornea was performed using silver nitrate/potassium nitrate sticks, and the rats were subsequently treated daily with topical (10 mg/ml), subconjunctival (10 mg/ml) or intraperitoneal (19 mg/kg) itraconazole for 7 days. Control rats received topical, subconjunctival or intraperitoneal 0.9% saline. On the 8th day of the experiment, the rat corneas were photographed to determine the percentage area of the cornea covered by neovascularization. The maximum density of corneal neovascularization was determined by microscopy. RESULTS: The median percentage of corneal neovascularization for group 1 was 31.5% (95% confidence interval, 27.5-35.5%); in group 3, it was 32% (23.5-39.8%); in group 5, it was 47% (36.3-60.0%). The percentages of corneal neovascularization in groups 2, 4 and 6 (the control groups) were 70% (95% confidence interval, 60.7-77.3%), 69% (63.0-77.7%) and 68% (56.5-78.5%), respectively. The area of neovascularization was smaller after itraconazole treatment as compared to saline treatment. Further, the area of neovascularization was smaller after topical and subconjunctival administration than after intraperitoneal administration. Histological evaluation of the corneas showed the most extensive corneal neovascularization in the control group. No local or systemic adverse effects were seen from either treatment group. CONCLUSION: Itraconazole reduces corneal neovascularization shortly after chemical burn. However, a larger experimental study is necessary to confirm the data of this investigation.

Apoptosis of hippocampus and cerebellum induced with brain ischemia reperfusion prevented by 3',4'-dihydroxyflavonol (DiOHF).

The present study aimed to determine the effect of 3',4'-dihydroxyflavonol (DiOHF) on apoptosis in the cerebellum and hippocampus in rats with ischemia-reperfusion. A total of 38 Wistar albino male rats were used. Experimental groups were designed as Group 1-Sham; Group 2-Ischemia-reperfusion (IR), in which animals were anesthetized and carotid arteries ligated for 30 minutes (ischemia) and reperfused 30 minutes; Group 3- IR + DiOHF (10 mg/kg); Group 4- Ischemia + DiOHF (10 mg/kg) + reperfusion; Group 5-DiOHF + IR. DiOHF was supplemented as 10 mg/kg by intraperitoneal injection 30 minutes before IR. Following application, the animals were sacrificed under general anesthetic by cervical dislocation, and the cerebellum and hippocampus tissues were analyzed for apoptosis. IR significantly increased hippocampus and cerebellum apoptosis activity, confirmed by Hematoxylin-Eosin, TUNEL labeling, and Caspase-8 activity. However, these values were significantly suppressed by the administration of DiOHF, especially when used before the ischemia and reperfusion. The results of the study show that increased apoptosis in the cerebellum and hippocampus tissue was inhibited by intraperitoneal DiOHF supplementation.

Effect of 2-Week Naringin Supplementation on Neurogenesis and BDNF Levels in Ischemia-Reperfusion Model of Rats.

BACKGROUND: Ischemic stroke is the leading cause of mortality and disability worldwide with more than half of survivors living with serious neurological sequelae; thus, it has recently attracted a lot of attention in the field of medical study. PURPOSE: The aim of this study was to determine the effect of naringin supplementation on neurogenesis and brain-derived neurotrophic factor (BDNF) levels in the brain in experimental brain ischemia-reperfusion. STUDY DESIGN: The research was carried out on 40 male Wistar-type rats (10-12 weeks old) obtained from the Experimental Animals Research and Application Center of Selçuk University. Experimental groups were as follows: (1) Control group, (2) Sham group, (3) Brain ischemia-reperfusion group, (4) Brain ischemia-reperfusion + vehicle group (administered for 14 days), and (5) Brain ischemia-reperfusion + Naringin group (100 mg/kg/day administered for 14 days). METHODS: In the ischemia-reperfusion groups, global ischemia was performed in the brain by ligation of the right and left carotid arteries for 30 min. Naringin was administered to experimental animals by intragastric route for 14 days following reperfusion. The training phase of the rotarod test was started 4 days before ischemia-reperfusion, and the test phase together with neurological scoring was performed the day before and 1, 7, and 14 days after the operation. At the end of the experiment, animals were sacrificed, and then hippocampus and frontal cortex tissues were taken from the brain. Double cortin marker (DCX), neuronal nuclear antigen marker (NeuN), and BDNF were evaluated in hippocampus and frontal cortex tissues by Real-Time qPCR analysis and immunohistochemistry methods. RESULTS: While ischemia-reperfusion increased the neurological score values, DCX, NeuN, and BDNF levels decreased significantly after ischemia in the hippocampus and frontal cortex tissues. However, naringin supplementation restored the deterioration to a certain extent. CONCLUSION: The results of the study show that 2 weeks of naringin supplementation may have protective effects on impaired neurogenesis and BDNF levels after brain ischemia and reperfusion in rats.

Investigation of the hepatoprotective effects of Sesame (Sesamum indicum L.) in carbon tetrachloride-induced liver toxicity.

More than 600 chemicals can cause damage in liver, one of which is carbon tetrachloride (CCl4). Hepatoprotective agents could prevent tissue damage and reduce morbidity and mortality rates; such agents may include alternative or folkloric treatments. We investigated sesame (Sesamum indicum L.) for its hepatoprotective effect in CCl4-induced experimental liver damage. To this end, 0.8 mg/kg of sesame fixed oil was provided intraperitoneally to rats whose livers were damaged by CCl4. Tissue and blood samples were taken at the end of the experiments and evaluated histologically and biochemically. Ballooning degenerations and an increase in lipid droplets in liver parenchyma and increases in serum alanine transaminase, aspartate transaminase, and bilirubin were found in the CCl4 group. Biochemical and histopathological findings in the sesame fixed oil treated group were not significantly different from the CCl4 group. Sesame did not show a hepatoprotective effect in CCl4-induced liver toxicity.

Active shrinkage protects neurons following axonal transection.

Trauma, vascular events, or neurodegenerative processes can lead to axonal injury and eventual transection (axotomy). Neurons can survive axotomy, yet the underlying mechanisms are not fully understood. Excessive water entry into injured neurons poses a particular risk due to swelling and subsequent death. Using in vitro and in vivo neurotrauma model systems based on laser transection and surgical nerve cut, we demonstrated that axotomy triggers actomyosin contraction coupled with calpain activity. As a consequence, neurons shrink acutely to force water out through aquaporin channels preventing swelling and bursting. Inhibiting shrinkage increased the probability of neuronal cell death by about 3-fold. These studies reveal a previously unrecognized cytoprotective response mechanism to neurotrauma and offer a fresh perspective on pathophysiological processes in the nervous system.

The Effects of Silymarin Supplementation on Post-Thawed Human Sperm Functional Parameters.

This study investigated the effect of silymarin on human sperm quality during cryopreservation. Samples were collected from 20 normospermic individuals, and each sample was divided into different concentrations of silymarin comprising the following groups: (0, 20, 100, 500, and 1000 µg/mL silymarin). Sperm quality parameters, such as plasma membrane integrity, mitochondrial membrane potential, acrosomal membrane integrity, and caspase 3 were estimated. Silymarin concentrations of 100-500 µg/mL significantly increased motility, plasma membrane integrity, and mitochondrial activity compared with the frozen control group. Acrosomal integrity was increased in the 1000 µg/mL silymarin group. Moreover, 20 and 100 µg/mL concentrations significantly decreased the percentage of caspase 3. The addition of silymarin antioxidant to the frozen medium reduced damage in the sperm after freezing and thawing. This is the first study that showed silymarin can be useful in cryopreservation of human sperm.

A new definition about the relationship of intercellular fluid in the brain with the mandibular and parotid lymph nodes.

This study was carried out to reveal the relationship of the brain with both the mandibular lymph node (MLN) and parotid lymph node (PLN) by the hyperspectral fluorescence imaging techniques of Qdot 800 (QD) nanoparticles using in vivo. This relationship of the brain with both lymph nodes offers the preliminary morphological definition of lymphatic drainage. QD was injected into the left parietal brain lobe of each rat at a depth of 2.50 mm. In 65% of the rats that were imaged in vivo, signals were received first from the right MLN and PLN, and then from the left MLN and PLN. In contrast, in two female rats, the first signal was received from the right PLN. There was no difference between the female and male rats overall. The most noteworthy finding of this study was that the tracer injected into the left parietal lobe reached the right mandibular and parotid lymph nodules earlier. This result indicates a different and unknown pathway in the brain that communicates with the lymph nodes. Moreover, this study shows that these lymph nodes pathways can be used in the treatment of diseases such as brain trauma, cerebral edema, and Alzheimer's disease (AD).

Effects of amantadine and topiramate on neuronal damage in rats with experimental cerebral ischemia-reperfusion.

BACKGROUND: Ischemia-reperfusion models are used to evaluate treatment options that may minimize cellular damage after ischemia. OBJECTIVES: To investigate the effects of amantadine and topiramate on apoptosis and cellular oxidative damage. MATERIAL AND METHODS: This experiment was performed using 30 male Wistar albino rats. The right internal carotid artery was identified and clamped with an aneurysm clip under general anesthesia, except for animals in the control group. After 10 min of occlusion, the aneurysm clip was removed, allowing reperfusion. After reperfusion and a waiting period of 12 h, the test and control groups were intraperitoneally administered the following solutions: the sham group received 10 mg/kg of isotonic solution, the amantadine group received 20 mg/kg of amantadine, the topiramate group received 40 mg/kg of topiramate, and the amantadine-topiramate group received 20 mg/kg of amantadine and 40 mg/kg of topiramate. After 24 h, the rats were euthanized. RESULTS: Apoptosis was evaluated using the TUNEL method. Total antioxidant status (TAS), total oxidant status (TOS), total thiol, and ischemia-modified albumin (IMA) levels were measured in both brain tissue and serum samples. The rate of apoptosis in the sham and amantadine groups increased significantly compared to the control group and the non-ischemic counter hemisphere. In the amantadine-topiramate group, both serum TAS and tissue thiol levels decreased. Tissue TOS levels were significantly higher in the topiramate group compared to all other test groups. Tissue TAS levels were significantly higher in the amantadine group compared to all other test groups. CONCLUSIONS: This experimental ischemia-reperfusion model revealed that topiramate reduces apoptosis in the early period after ischemia and that its combination with amantadine does not provide additional benefits against cell death. However, topiramate did not have an inhibitory effect on the oxidative stress biomarkers used in our study (TAS, TOS, IMA, and thiol). Studies that reveal the neuroprotective mechanism of action and long-term effects of topiramate are needed to complement this study.

Increased apoptosis, tumor necrosis factor-α, and DNA damage attenuated by 3',4'-dihydroxyflavonol in rats with brain Ischemia-reperfusion.

OBJECTIVES: This research was aimed to find out the effects of 3',4'-dihydroxyflavonol (DiOHF) on apoptosis, DNA damage, and tumor necrosis factor-α (TNF-α) levels in the frontal cortex of rats with induced experimental brain ischemi reperfusion. MATERIALS AND METHODS: A total of 38 Wistar albino male rats were used. Groups were created as 1-Sham; 2-Ischemia-reperfusion (I/R); 3-I/R + DiOHF (10 mg/kg); 4-Ischemia + DiOHF + reperfusion; 5-DiOHF + I/R. I/R was performed by carotid artery ligation for 30 min in anesthesized animals. Following experimental applications, blood samples were taken from anesthetized rats to obtain erythrocyte and plasma. Later, the rats were killed by cervical dislocation, and frontal cortex samples were taken and stored at - 80oC for the analysis. RESULTS: In the ischemic frontal cortex tissue sections degenerate neuron numbers, Terminal deoxynucleotidyl transferase-dUTP nick end labeling (TUNEL) positive cell ratio and caspase-3 positive cell ratio increased. Malondialdehyde, TNF-α, and 8-OHdG levels were increased in both plasma and tissue in ischemia group, whereas tissue and erythrocyte glutathione levels were significantly suppressed. However, these values were significantly reversed by DiOHF treatment. CONCLUSION: The results of the study showed that I/R significantly increased apoptosis, TNF-α, and DNA damage in rats with brain I/R. However, 10 mg/kg intraperitoneal DiOHF treatment improved deterioted parameters.

Postconditioning Ozone Alleviates Ischemia-Reperfusion Injury and Enhances Flap Endurance in Rats.

Introduction: Muscle-flap transferring is a routine approach utilized in reconstructive operations; however, flap morbidity is often a source of post-operative difficulty. Ischemia-Reperfusion Injury (IRI) is an important contributor to the viability of flaps after transferring. The goal of this research was for assess the probable useful impacts of ozone on flap survival in a rat muscle-flap design. Materials and Methods: We examined the effects of postconditioning ozone administration on viability of pedicled composite flaps. Twenty-eight Wistar rats were randomized into four groups: sham-operated (S), ischemia-reperfusion (IR), sham-operated + ozone (O), IR + ozone (IR + O), respectively. The animals were sacrificed on the eighth day. In a general histological evaluation, flap tissues were examined with a light microscope, and apoptotic cells were counted. The Apoptotic Index (AI) was then calculated. Flap-tissue samples were sent for analyses of malondialdehyde (MDA), catalase (CAT), glutathione peroxidase (GSH-Px), superoxide dismutase (SOD), and protein carbonyl (PCO), and blood samples were sent for analyses of Total Oxidant Score (TOS), and Total Antioxidant Capacity (TAC). Data were evaluated statistically using the Kruskal-Wallis test. Results: The histomorphometric score was remarkably greater in O (p = .002). The AI was greater in IR (p = .002). The antioxidant parameters values as regards SOD, GSH-Px, CAT, and TAC were found to be greater in O (p < .005). The oxidant parameters values as regards MDA, PCO, TOS were found to be greater in IR (p < .005). Discussion: The current research indicates that ozone application can attenuate the muscle-flap injury brought about by IR through triggering the increase of the antioxidant capacity.

Transfer and Integration of Breast Milk Stem Cells to the Brain of Suckling Pups.

Beside its unique nutritional content breast milk also contains live cells from the mother. Fate of these cells in the offspring has not been adequately described. In this study, we aimed to detect and identify maternal cells in the suckling's blood and the brain. Green fluorescent protein expressing transgenic female mice (GFP+) were used as foster mothers to breastfeed wildtype newborn pups. One week and two months after the birth, blood samples and brains of the sucklings were analyzed to detect presence of GFP+ cells by fluorescence activated cell sorting, polymerase chain reaction and immunohistochemistry on the brain sections and optically cleared brains. The tests confirmed that maternal cells were detectable in the blood and the brain of the pups and that they differentiated into both neuronal and glial cell types in the brain. This phenomenon represents breastfeeding - induced microchimerism in the brain with functional implications remain to be understood.

Isolation and culture of adult mouse vestibular nucleus neurons

Background/aim: Isolated cell cultures are widely used to study neuronal properties due to their advantages. Although embryonic animals are preferred for culturing, their morphological or electrophysiological properties may not reflect adult neurons, which may be important in neurodegenerative diseases. This paper aims to develop a method for preparing isolated cell cultures of medial vestibular nucleus (MVN) from adult mice and describe its morphological and electrophysiological properties.Materials and methods: Vestibular nucleus neurons were mechanically and enzymatically isolated and cultured using a defined medium with known growth factors. Cell survival was measured with propidium iodide, and electrophysiological properties were investigated with current-clamp recording.Results: Vestibular neurons grew neurites in cultures, gaining adult-like morphological properties, and stayed viable for 3 days in culture. Adding bovine calf serum, nerve growth factor, or insulin-like growth factor into the culture medium enhanced neuronal viability. Current-clamp recording of the cultured neurons revealed tonic and phasic-type neurons with similar input resistance, resting membrane potential, action potential amplitude, and duration. Conclusion: Vestibular neurons from adult mice can be cultured, and regenerate axons in a medium containing appropriate growth factors. Culturing adult vestibular neurons provides a new method to study age-related pathologies of the vestibular system.

Effects of exposure to 2100MHz GSM-like radiofrequency electromagnetic field on auditory system of rats.

INTRODUCTION: The use of mobile phones has become widespread in recent years. Although beneficial from the communication viewpoint, the electromagnetic fields generated by mobile phones may cause unwanted biological changes in the human body. OBJECTIVE: In this study, we aimed to evaluate the effects of 2100MHz Global System for Mobile communication (GSM-like) electromagnetic field, generated by an electromagnetic fields generator, on the auditory system of rats by using electrophysiological, histopathologic and immunohistochemical methods. METHODS: Fourteen adult Wistar albino rats were included in the study. The rats were divided randomly into two groups of seven rats each. The study group was exposed continuously for 30days to a 2100MHz electromagnetic fields with a signal level (power) of 5.4dBm (3.47mW) to simulate the talk mode on a mobile phone. The control group was not exposed to the aforementioned electromagnetic fields. After 30days, the Auditory Brainstem Responses of both groups were recorded and the rats were sacrificed. The cochlear nuclei were evaluated by histopathologic and immunohistochemical methods. RESULTS: The Auditory Brainstem Responses records of the two groups did not differ significantly. The histopathologic analysis showed increased degeneration signs in the study group (p=0.007). In addition, immunohistochemical analysis revealed increased apoptotic index in the study group compared to that in the control group (p=0.002). CONCLUSION: The results support that long-term exposure to a GSM-like 2100MHz electromagnetic fields causes an increase in neuronal degeneration and apoptosis in the auditory system.

Multidimensional long-term time-lapse microscopy of in vitro peripheral nerve regeneration.

In order to test the effectiveness of a new advanced time-lapse microscopy imaging and image processing and analysis system, and to do quantitative and qualitative temporal analyses of in vitro peripheral nerve regeneration, long-term time-lapse imaging of cultures of mouse dorsal root ganglia (DRGs) was performed. DRGs were placed in a Petri dish, covered with collagen gel, their attached peripheral nerves were cut in the middle, creating a gap, and the dish was filled with culture medium. Six preparations were kept on the time-lapse imaging system, which provides a suitable incubation environment and enables to capture images from multiple coordinates at x,y,z axes at desired time intervals for 13 days. In general, the time-lapse imaging system proved quite stable and efficient, although some improvements are certainly required. Two main components of peripheral nerve regeneration, outgrowth of axons and activities of resident cells, were examined. Axons started to grow during the first hour of incubation with a 16.5 microm/h rate and showed the slowest rates (0.7 microm/h) on days 8 and 9, after which they resumed higher speeds again. The first cell came out of the proximal end of the cut nerve on the second day and it was a Schwann cell (SC), which was the prominent cell type in the preparations throughout the experiment. SCs were higher in number (83.15% of all cells) but slower in migration (3.4 vs. 7.3 microm/h, P < 0.001) than other cells. Other observed characteristics of axonal outgrowth and cellular activity and interactions between axons and the cells are discussed.

Inhibition of corneal neovascularization by topical and subconjunctival tigecycline.

Objective. To investigate the effects of topical and subconjunctival tigecycline on the prevention of corneal neovascularization. Materials and Methods. Following chemical burn, thirty-two rats were treated daily with topical instillation of 1 mg/mL tigecycline (group 1) or subconjunctival instillation of 1 mg/mL tigecycline (group 3) for 7 days. Control rats received topical (group 2) or subconjunctival (group 4) 0.9% saline. Digital photographs of the cornea were taken on the eighth day after treatment and analyzed to determine the percentage area of the cornea covered by neovascularization. Corneal sections were analyzed histopathologically. Results. The median percentages of corneal neovascularization in groups 1 and 3 were 48% (95% confidence interval (CI), 44.2-55.8%) and 33.5% (95% CI, 26.6-39.2%), respectively. The median percentages of corneal neovascularization of groups 1 and 3 were significantly lower than that of the control group (P = 0.03 and P < 0.001, resp.). Histologic examination of samples from groups 1 and 3 showed lower vascularity than that of control groups. Conclusion. Topical and subconjunctival administration of tigecycline seems to be showing promising therapeutic effects on the prevention of corneal neovascularization. Furthermore, subconjunctival administration of tigecycline is more potent than topical administration in the inhibition of corneal neovascularization.

Consequences of neurite transection in vitro.

In order to quantify degenerative and regenerative changes and analyze the contribution of multiple factors to the outcome after neurite transection, we cultured adult mouse dorsal root ganglion neurons, and with a precise laser beam, we transected the nerve fibers they extended. Cell preparations were continuously visualized for 24 h with time-lapse microscopy. More distal cuts caused a more elongated field of degeneration, while thicker neurites degenerated faster than thinner ones. Transected neurites degenerated more if the uncut neurites of the same neuron simultaneously degenerated. If any of these uncut processes regenerated, the transected neurites underwent less degeneration. Regeneration of neurites was limited to distal cuts. Unipolar neurons had shorter regeneration than multipolar ones. Branching slowed the regenerative process, while simultaneous degeneration of uncut neurites increased it. Proximal lesions, small neuronal size, and extensive and rapid neurite degeneration were predictive of death of an injured neuron, which typically displayed necrotic rather than apoptotic form. In conclusion, this in vitro model proved useful in unmasking many new aspects and correlates of mechanically-induced neurite injury.

Effects of topical mitomycin and trimetazidine on myringosclerosis.

INTRODUCTION: Myringosclerosis, one of the most common complications of ventilation tube placement, is a kind of tympanosclerosis and is defined as subepithelial hyalinization of the tympanic membrane. There are two arguments in the development of myringosclerosis: inflammation triggering the development of myringosclerosis and free oxygen radicals released during inflammation causing myringosclerosis. OBJECTIVE: The aim of the present study was to explore the effects on the development of myringosclerosis of mitomycin, which has anti-inflammatory effects, and trimetazidine, which is believed to inhibit free oxygen radicals when given systemically. MATERIALS AND METHOD: The study was carried out on rabbits. Animals were divided into five groups, with six rabbits in each group: three control groups (paracentesis only, paracentesis+tube placement, and no intervention), a trimetazidine group, and a mitomycin group. Mitomycin (0.4 mg/mL) and trimetazidine (20 mg/mL) were applied topically to the tympanic membrane, and the presence and degree of sclerosis were graded histopathologically after Masson's trichrome staining. RESULTS: In the histopathologic examination, sclerosis that developed in the tympanic membranes of rabbits that had undergone paracentesis or paracentesis plus tube application or received trimetazidine was significantly more extensive than sclerosis in the membranes of unoperated animals and those that had been administered mitomycin. CONCLUSIONS: Paracentesis in rabbits, independent of tube placement, causes sclerosis of the tympanic membrane. Results show that topical use of mitomycin, due to its anti-inflammatory effect, had alleviating effects on myringosclerosis, whereas topical trimetazidine did not.