Effects of vitrification solution supplemented with platelet-rich plasma in rat ovarian tissue cryopreservation.

Background/aim: The subject of this study was to investigate the utility of platelet-rich plasma (PRP) in the cryopreservation process to reduce cryodamage and increase tissue viability. Materials and methods: Twenty-one female Wistar rats were randomly allocated to three groups. In Group 1 (G1), rats were not subjected to vitrification (n = 7). Group 2 (G2) was the vitrification group in which PRP was added to the basic vitrification solution (n = 7). Group 3 (G3) was the vitrification group in which fetal bovine serum was added to the basic vitrification solution (n = 7). Warmed tissues were evaluated with histochemical (HC) and immunohistochemical (IHC) staining, the TUNEL method, immunofluorescence (IF) staining, and biochemical analyses. Results: The percentages of IHC staining, TUNEL method positivity, and IF staining were significantly higher in G2 compared to both G1 and G3 (P < 0.05). G2 ovaries exhibited a significant increase in both malondialdehyde and catalase values in comparison to G1 (P < 0.05). In HC staining, degenerations in primary and secondary follicles and in ovarian tissue were more common in the PRP-supplemented group. The calcium used in PRP activation was suspected to have increased the degeneration and prevented the possible positive effects of PRP. Conclusion: To the best of our knowledge, PRP-supplemented vitrification solution was used for the first time in the literature in this study in whole rat ovarian tissue vitrification. If PRP is to be used as a component in vitrification solution for rat ovarian tissue, the use of lower amounts of calcium or different methods in PRP activation, or the use of nonactivated PRP, should be considered from the beginning.

Acute hypoxia exposure following prenatal stress impairs hippocampus and novelty-seeking behavior in adolescent rats.

OBJECTIVES: The present study aimed to investigate the effects of acute hypoxia exposure following prenatal stress on the novelty-seeking behavior and hippocampus of adolescent rats. METHODS: The offspring were divided into prenatal stress (PS) and non-stress (NS) groups. Both groups were exposed to hypoxia on postnatal day 10 (P10) while control groups were undisturbed. Novel object recognition task was performed in each group. Next, brains were collected to examine hippocampus via immunohistochemical and biochemical studies on postnatal day 35 (P35). RESULTS: PS decreased novelty discrimination and synaptophysin (SYN) expressions in both CA1 and CA3 of the hypoxia group prominently (p < 0.05). Nestin-expressing cells were reduced while vascular endothelial growth factor (VEGF) expression was enhanced in the subgranular zone (SGZ) of PS-hypoxia group (p < 0.05). VEGF enhancement triggered angiogenesis in the CA1 and CA3 significantly (p < 0.05). PS also increased thiobarbituric acid reactive substances (TBARS) levels in the hypoxia group as a result of oxidative stress (p < 0.05). CONCLUSION: These findings demonstrated that PS exacerbates neurodevelopmental deficits in the hippocampus of acute hypoxia-induced offspring in adolescence.

The effects of IGF-1 and erythropoietin on apoptosis and telomerase activity in necrotizing enterocolitis model.

BACKGROUND: Apoptosis that occurs after hypoxia/reoxygenation (H/R) has an important role in the pathogenesis of necrotizing enterocolitis (NEC). Telomerase activity, showing the regeneration capacity, may also be important in the recovery process. Therefore, we aimed to investigate the effects of insulin-like growth factor-1 (IGF-1) and erythropoietin (EPO) on apoptosis and telomerase activity in an H/R model. METHODS: Young mice were divided into four groups each containing ten Balb/c mice. Group 1 (H/R) were exposed to H/R; group 2 and group 3 were pretreated with IGF-1 and EPO, respectively, for 7 days before H/R. Group 4 served as control. Intestinal injury was evaluated by histological scoring and assessment of apoptosis was performed by terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL) test. Proapoptotic and antiapoptotic gene expressions and telomerase activity were analyzed by real-time PCR. RESULTS: IGF-1- and EPO-treated animals had decreased histological damage and apoptosis, confirmed by TUNEL test and caspase activity. Telomerase activity was increased in these animals in addition to increased expression of antiapoptotic genes. However, proapoptotic gene expressions were not statistically different. CONCLUSIONS: The protective effects of IGF-1 and EPO in H/R damage may be through increased expression of antiapoptotic genes and increased telomerase activity, especially for IGF-1. IMPACT: This is a comprehensive study measuring various variables, namely IGF-1, EPO, apoptosis, apoptotic and antiapoptotic genes, and telomerase activity in the NEC model. The intestinal protective effects of IGF-1 and EPO in H/R damage may occur through increased expression of antiapoptotic genes and increased telomerase activity. To the best of our knowledge, telomerase activity has not been investigated in the NEC model before. Regarding our results, novel strategies may be implemented for the early definitive diagnosis, robust preventive measures, and effective treatment modalities for NEC.

Fetal Gene Therapy Using a Single Injection of Recombinant AAV9 Rescued SMA Phenotype in Mice.

Symptoms of spinal muscular atrophy (SMA) disease typically begin in the late prenatal or the early postnatal period of life. The intrauterine (IU) correction of gene expression, fetal gene therapy, could offer effective gene therapy approach for early onset diseases. Hence, the overall goal of this study was to investigate the efficacy of human survival motor neuron (hSMN) gene expression after IU delivery in SMA mouse embryos. First, we found that IU-intracerebroventricular (i.c.v.) injection of adeno-associated virus serotype-9 (AAV9)-EGFP led to extensive expression of EGFP protein in different parts of the CNS with a great number of transduced neural stem cells. Then, to implement the fetal gene therapy, mouse fetuses received a single i.c.v. injection of a single-stranded (ss) or self-complementary (sc) AAV9-SMN vector that led to a lifespan of 93 (median of 63) or 171 (median 105) days for SMA mice. The muscle pathology and number of the motor neurons also improved in both study groups, with slightly better results coming from scAAV treatment. Consequently, fetal gene therapy may provide an alternative therapeutic approach for treating inherited diseases such as SMA that lead to prenatal death or lifelong irreversible damage.

Melatonin Attenuates Histopathological Changes in the Hippocampus of Infantile Rats with Kaolin-Induced Hydrocephalus.

OBJECTIVE/AIM: Hydrocephalus is defined as an incapacitating neurological disorder characterized by ventricular enlargement in children, but the effects of melatonin on this hydrocephalus have not yet been fully elucidated. In the present experiment, we attempted to investigate the effects of exogenous melatonin administration on hydrocephalus-induced hippocampal changes in infantile rats. METHODS: In this study, we randomly divided 45 Swiss albino rats aged 2 weeks into 3 groups: group I, the control group received a sham injection with needle insertion only; groups II and III were given kaolin injections before treatment - group II, the hydrocephalus group, was treated with an isotonic NaCl solution, and group III, the hydrocephalus plus melatonin group, was treated with 0.5 mg/100 g body weight of exogenous melatonin. Both immunohistochemical and histological analyses were performed after hydrocephalus induction and melatonin administration. Immunohistochemical staining consisted anti-glial fibrillary acidic protein staining. The TUNEL technique was used for defining quantitate apoptosis. RESULTS: Melatonin administration significantly attenuated chronic hydrocephalus-induced histopathological changes in the hippocampal subregions of infantile rats. Compared to hydrocephalic rats treated with saline solution, melatonin significantly decreased the number of apoptotic cells and pyknotic index values of each hippocampal subregion after the kaolin-induced hydrocephalus (p < 0.001). CONCLUSION: The present results demonstrate that the chronic hydrocephalus-induced histopathological changes in the hippocampus were partially reversible with melatonin treatment, suggesting its neuroprotective effects in infantile rats. However, these findings need to be confirmed by further experimental studies and clinical trials.

Effects of Melatonin on the Cerebellum of Infant Rat Following Kaolin-Induced Hydrocephalus: a Histochemical and Immunohistochemical Study.

Hydrocephalus is a developmental disorder causing abnormally collected cerebrospinal fluid within the cerebral ventricles. It leads to bigger skulls and many dysfunctions related to the nervous system. Here, we addressed whether exogenous melatonin administration could reverse the clinical features of kaolin-induced hydrocephalus in infantile rats. A controlled double-blinded study was conducted in 2-week-old 45 Wistar albino rats, which were divided into three groups: Group A, the control group, received intracisternal sham injection with solely the needle insertion; group B, the hydrocephalus group, was treated with isotonic NaCl after kaolin injection; and group C, the hydrocephalus + melatonin group, was given i.p. exogenous melatonin at a dose of 0.5 mg/100 g body weight after kaolin injection. Histological and immunohistochemical analyses were performed after the induction of hydrocephalus and melatonin administration. Glial fibrillary acidic protein was stained by immunohistochemical method. TUNEL method was used to define and quantitate apoptosis in the cerebellar tissues. Statistical analysis was performed by nonparametric Kruskal-Wallis H test, and once significance was determined among means, post hoc pairwise comparisons were carried out using Mann-Whitney U test. We found that melatonin administration significantly ameliorated ratio of substantia grisea area/substantia alba area in the cerebellum of infantile rats. Histologically, there was a significant reduction in the number of cerebellar apoptotic cells after the hydrocephalus induced by kaolin (P < 0.05). Our results clearly revealed that the histopathological changes in the cerebellum were reversed by systemic melatonin administration in infantile rats with kaolin-induced hydrocephalus. Nevertheless, further studies are needed to suggest melatonin as a candidate protective drug in children with hydrocephalus.

Effects of Levetiracetam on neural tube development and closure of the chick embryos in ovo.

PURPOSE: Effects of Levetiracetam (LEV) within its therapeutic range at a 50 mg/kg dose for the chick embryo in ovo has been studied in order to demonstrate whether LEV would effect neural tube closure at the macroscopic morphology or LEV administered embryos still encounter neuroglial detrimental effects at the histological level. METHODS: Embryos were randomly seperated into control (n = 20) and study (n = 20) groups. The eggshell was windowed at specifically 24 h of incubation, and area underlying the membrane was excised to allow injection with 4.5 µl LEV in the study group, while physiologic saline (0.045 ml) were injected in the control group and each egg were re-incubated for 48 h more. Then, histological and immunohistochemical evaluation of the subjects were done. RESULTS: Macroscopic evaluation revealed immaturity of the placental vessel network in number and width for the study group in comparison to the controls. Defects of migration, decrease in the crista neuralis content, delay of the basal plates structures in the formation of the usual configuration, and delay in the cellular proliferation and the delay of development for the central nervous system were determined in the LEV-exposed group. Immunostaining of S100 proteins in this study has clearly demonstrated increased expression patterns of both neuroglial and neuronal cell populations. Toluidine blue stainings revealed mostly bipolar, differentiating neurons and crista neuralis cells which is concordant with active migration and differentiation. CONCLUSIONS: LEV found that delay in the closure of the neural tube and microcephalic fetuses disturb further morphological, biochemical, and functional development.

Investigation of maternal melatonin effect on the hippocampal formation of newborn rat model of intrauterine cortical dysplasia.

OBJECTIVES: Cortical dysplasia is a cortical malformation resulting from any developmental defects during different periods of development. This study aims to investigate the hippocampal histopathological alterations in the neonates with cortical dysplasia due to the prenatal exposure to carmustine (1,3-bis (2-chloroethyl)-1-nitrosourea; BCNU) and the possible effects of prophylaxis with melatonin, a neuroprotective agent. METHODS: Wistar albino female rats were randomly divided into four experimental groups; control, melatonin-treated, BCNU-exposed and BCNU-exposed+melatonin-treated. Light microscopy and immunohistochemistry were carried out on the newborn hippocampus. RESULTS: Histopathology of hippocampus from the control and melatonin-treated groups showed continuity of migration and maturation as pathognomonic signs of the normal newborn hippocampus. Hippocampal cortex from the newborns exposed in utero to BCNU showed the histology of early embryonic hippocampal formation with immunohistochemical increase in the number of nestin positive cells and decreases in the immunoreactivity of glial fibrillary acidic protein (GFAP) and synaptophysin. These findings indicate a significant delay in hippocampal maturation, migration, and synaptogenesis. Intrauterine treatment of BCNU-exposed rats with melatonin resulted in histopathological features almost similar to control group. CONCLUSION: It has been concluded that cortical dysplasia induced by intrauterine BCNU administration results in delayed hippocampal maturation, which is successfully restored by intrauterine melatonin treatment.

Stereological analysis of sciatic nerve in chickens following neonatal pinealectomy: an experimental study.

BACKGROUND: Although the injury to the peripheral nervous system is a common clinical problem, understanding of the role of melatonin in nerve degeneration and regeneration is incomplete. METHODS: The current study investigated the effects of neonatal pinealectomy on the sciatic nerve microarchitecture in the chicken. The chickens were divided into two equal groups: unpinealectomized controls and pinealectomized chickens. At the end of the study, biochemical examination of 10 sciatic nerve samples from both groups was performed and a quantitative stereological evaluation of 10 animals in each group was performed. The results were compared using Mann-Whitney test. RESULTS: In this study, the results of axon number and thickness of the myelin sheath of a nerve fiber in newly hatched pinealectomy group were higher than those in control group. Similarly, surgical pinealectomy group had significantly larger axonal cross-sectional area than the control group (p < 0.05). In addition, the average hydroxyproline content of the nerve tissue in neonatal pinealectomy group was higher than those found in control group. Our results suggest that melatonin may play a role on the morphologic features of the peripheral nerve tissue and that melatonin deficiency might be a pathophysiological mechanism in some degenerative diseases of peripheral nerves. The changes demonstrated by quantitative morphometric methods and biochemical analysis has been interpreted as a reflection of the effects of melatonin upon nerve tissue. CONCLUSION: In the light of these results from present animal study, changes in sciatic nerve morphometry may be indicative of neuroprotective feature of melatonin, but this suggestion need to be validated in the human setting.

Effects of 2,4-dichlorophenoxyacetic acid formulation on medulla spinalis of Poecilia reticulata: a histopathological study.

This study investigated the possible effects of a commonly used foliar herbicide 2,4-dichlorophenoxyacetic acid (2,4-D) formulation on medulla spinalis of lebistes. Fish were exposed to 2,4-D (15, 30, 45 mg L(-1)), behavioral changes were monitored. Fish were fixed, histopathological examination was carried out on sections taken from the upper parts of the fish body. Histopathology showed increase in neuronal loss, swelling indicating formation of intracellular edema, vacuolization noticed as the formation of vacuoles within or adjacent to cells, deformation in the Nissl granules, pyknosis and gliosis in medulla spinalis. Behavioral changes were decreased general activity, grouping, shortness in breath, sudden rotations and jumping, loss of equilibrium and colour. In conclusion, this commercial formulation of 2,4-D is considerably neurotoxic to lebistes. Fish constitute the last link in the chain of the feeding cycle in aquatic eco-system, number of studies investigating acute and chronic neurotoxicity of various herbicides in fish should be increased.

Immunohistochemical and histopathological evaluation of 2,4-dichlorophenoxyacetic acid-induced changes in rat kidney cortex.

This study aims to investigate the effect of 2,4-dichlorophenoxyacetic acid (2,4-D) on rat kidney cortex histology. Oral exposure of rats to 2,4-D for 28 days resulted in decreases in body weight gain and kidney weight. Histological examination showed degeneration in renal corpuscles and podocytes; vacuolization in the glomerulus with disintegration of the basal membrane; tissue edema; vacuolization, cystic dilation and invagination of the basal laminae in the tubular structures; dilation and congestion in renal corpuscular vessels and marked decrease in glomerular and stromal fibronectin reaction; suggesting that subacute 2,4-D administration induces dose-dependent histopathological degenerative effects in rat kidney cortex.

Reabsorption of ascites and the factors that affect this process in cirrhosis.

Ascites is one of the main features of liver decompensation in cirrhosis, and it is considered to be a dynamic process. In this study, we aimed to (1) measure the reabsorption rate of ascites; (2) evaluate whether these findings were related to features of ascites, hemodynamics, and serum measurements; and (3) examine morphologic changes in the diaphragm of cirrhotic patients. In all, 42 cirrhotic patients with ascites were enrolled in the study to comprise our study group. Using the dextran 70 test, patient ascites volumes and reabsorption rates were measured. Biopsies from the peritoneal side of the diaphragm were also processed for scanning electron microscopy and lymphatic immunohistochemical studies from the cirrhotic patients and control cadavers. The mean ascites reabsorption rate was 4.5 +/- 4.5 (0.18-14.6) mL/min, which correlated significantly with the calculated ascites volume (r = 0.75, P < 0.001). The mean ascites viscosity was 1.07 +/- 0.07 (0.99-1.17) centipoise, which demonstrated a high degree of negative correlation with the ascites reabsorption rate (r = -0.77, P < 0.001). Patients with a history of spontaneous bacterial peritonitis had significantly lesser ascites reabsorption rates than patients without this particular history. The size of lymphatic stomata in scanning electron microscopy depictions was increased, and lymphatic lacunae were dilated in immunohistochemical studies in the cirrhotic patients with ascites. However, these findings were not uniform in every cirrhotic patient with ascites. The volume and viscosity of ascites seem to influence its reabsorption rate. Additionally, previous episodes of spontaneous bacterial peritonitis may be responsible for the decreased ascites reabsorption rates observed in certain patient populations.

Epidural lornoxicam administration -- innocent.

We aimed to determine the analgesic efficacy and clinical or histopathological neurotoxicity of epidural single-dose lornoxicam. Caudal epidural catheters were inserted into 28 rabbits, divided into four groups, on day 1. Pain latency and degree of motor and sensory loss for each animal for different concentrations of lornoxicam were determined on day 2. All animals were sacrificed on day 3 and laminectomy was performed. Five-mum thick sections of spinal cord, obtained from two segments caudal and two segments rostral from tip of the catheter, were fixed and were stained and evaluated by light microscopy. Lornoxicam produced dose-dependent analgesia (increase in pain latency), brief, mild and reversible motor and sensory block, and histopathological signs of neurotoxicity. Clinical application of epidural lornoxicam should proceed with caution.

Neuroprotective effects of melatonin upon the offspring cerebellar cortex in the rat model of BCNU-induced cortical dysplasia.

Cortical dysplasia is a malformation characterized by defects in proliferation, migration and maturation. This study was designed to evaluate the alterations in offspring rat cerebellum induced by maternal exposure to carmustine-[1,3-bis (2-chloroethyl)-1-nitrosoure] (BCNU) and to investigate the effects of exogenous melatonin upon cerebellar BCNU-induced cortical dysplasia, using histological and biochemical analyses. Pregnant Wistar rats were assigned to five groups: intact-control, saline-control, melatonin-treated, BCNU-exposed and BCNU-exposed plus melatonin. Rats were exposed to BCNU on embryonic day 15 and melatonin was given until delivery. Immuno/histochemistry and electron microscopy were carried out on the offspring cerebellum, and levels of malondialdehyde and superoxide dismutase were determined. Histopathologically, typical findings were observed in the cerebella from the control groups, but the findings consistent with early embryonic development were noted in BCNU-exposed cortical dysplasia group. There was a marked increase in the number of TUNEL positive cells and nestin positive cells in BCNU-exposed group, but a decreased immunoreactivity to glial fibrillary acidic protein, synaptophysin and transforming growth factor beta1 was observed, indicating a delayed maturation, and melatonin significantly reversed these changes. Malondialdehyde level in BCNU-exposed group was higher than those in control groups and melatonin decreased malondialdehyde levels in BCNU group (P<0.01), while there were no significant differences in the superoxide dismutase levels between these groups. These data suggest that exposure of animals to BCNU during pregnancy leads to delayed maturation of offspring cerebellum and melatonin protects the cerebellum against the effects of BCNU.

Light, electron microscopic and immunohistochemical study of the effect of low-dose aspirin during the proestrus phase on rat endometrium in the preimplantation period.

OBJECTIVE: To evaluate structural alterations in rat endometrium at preimplantation following treatment with aspirin beginning from proestrus by light microscopy, electron microscopy and immunohistochemical techniques. STUDY DESIGN: Twenty rats were divided into control (n = 10) and experimental (n = 10) groups. Experimental rats were treated with low-dose aspirin daily (2 mg/kg/day) during estrus, beginning from the proestrus phase, mated at end of cycle and treated with aspirin. Untreated pregnant rats were the control group. Rats in both groups were sacrificed at the 84th pregnancy hour; the uterus was rapidly removed and dissected free of surrounding adipose tissue. Uteri specimens from nonpregnant rats were transferred into fixative solution and processed for light, electron microscopic and immunohistochemical study. RESULTS: Light and electron microscopy of endometrium from control rats conformed to mid-diestrus phase; endometrial histology of the aspirin-treated group conformed to late diestrus phase. The endometrial layer was significantly thicker in the aspirin-treated group compared to the untreated control group (p <0.001). No significant difference was found in vessel number between groups. Staining with alphaV integrin was more dense in the aspirin-treated group. CONCLUSION: Based on histologic findings, we suggest low-dose aspirin has positive effects on preparing endometrium before implantation.

Efficacy of melatonin on offspring liver maturation in pinealectomized pregnant rats subjected to experimental epilepsy.

BACKGROUND AND AIMS: In clinical practice, maternal epilepsy is a disabling disease for newborn infants, but current data concerning the effect of epileptic phenomena in pregnant mothers on newborns are still limited. This study was undertaken to investigate the effects of pinealectomy (Px) and melatonin treatments on the morphological changes in the liver tissue of newborn rats following experimental epilepsy during pregnancy. METHODS: Female Swiss Albino rats were divided into five groups: intact control group; saline control group; epilepsy group; epilepsy plus Px group; and melatonin-treated epilepsy plus Px group. At one month after Px, an acute grand mal epileptic seizure was induced by penicillin-G during their pregnancy in all animals except the control groups. On the neonatal first day, newborn rats were perfused with intracardiac fixative solution, and then livers were removed and processed for toluidine blue, periodic acid-Schiff (PAS) and terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling (TUNEL) reactivity. RESULTS: Normal migration and hepatic maturation were determined in the postnatal rat liver in the control groups, while the morphological structure of the liver in the epilepsy and epilepsy plus Px groups corresponded to the early embryonic period. In the melatonin-treated epilepsy plus Px group, the number of TUNEL positive cells decreased significantly compared to both epilepsy and epilepsy plus Px groups; however, there was no statistically significant difference from the control groups as a result of melatonin activity. CONCLUSIONS: Some histological findings consistent with chronic fetal distress in newborns of mother rats with epilepsy and Px were observed. Melatonin could be a candidate protective drug for the development of liver tissue in pregnant patients with epilepsy.

Pinealectomy stimulates and exogenous melatonin inhibits harmful effects of epileptiform activity during pregnancy in the hippocampus of newborn rats: an immunohistochemical study.

OBJECTIVES: Epilepsy during the pregnancy is an important problem in clinical practice for newborn individuals. Recently, it has been demonstrated that mothers' epileptic seizures have some harmful effects on newborns, but present data concerning the effects of epileptic phenomena in pregnant mothers on newborn pups are still limited. The current study was undertaken to investigate the morphological changes in the hippocampus of newborn pups of pinealectomized rats subjected to experimental epilepsy during pregnancy. METHODS: In this study, rats were randomly divided into four groups (ten animals each): intact control group, epilepsy control group, surgical pinealectomy + epilepsy group, and group with melatonin treatment following pinealectomy procedure. The animals in surgical pinealectomy + epilepsy and melatonin treatment groups underwent a surgical intervention consisting of pineal gland removal. At 1 month after surgical pinealectomy, an acute grand mal epileptic seizure was induced by 400 IU penicillin G administration into their hippocampal CA3 region on the 13th day of their pregnancy in all animals except the intact control animals. On the first neonatal day, the hippocampi were removed and processed for microscopic examination. Nestin expression was analysed in the developing hippocampal tissue. RESULTS: Normal migration and hippocampal maturation were determined in the postnatal rat hippocampus in intact control group, but the morphological structure of the hippocampus in the epilepsy control group corresponded to the early embryonal period. It was found that experimental epilepsy and pinealectomy enhanced nestin immunoreactivity, whereas exogenous melatonin treatment (30 mug/100 g body weight, intraperitoneal) inhibited pinealectomy-stimulated nestin expression in CA1 region of the hippocampus. CONCLUSION: These findings suggest that epileptic seizures during pregnancy may cause an impaired hippocampal neurogenesis and neuronal maturation in the newborn, and the negative effects in the postnatal rat hippocampus are more dramatic after pinealectomy of the mother; conversely, melatonin administration suppresses these negative changes. This is the first report investigating the effects of maternal epilepsy during pregnancy in pinealectomized rats on nestin immunoexpression in the newborn rat hippocampus.

Beneficial effects of melatonin on morphological changes in postnatal cerebellar tissue owing to epileptiform activity during pregnancy in rats: light and immunohistochemical study.

Although it has been demonstrated that maternal epilepsy has some harmful effects on newborn individuals, current data concerning the effects of epileptic phenomena in pregnant mothers on newborn pups are still limited. This study was undertaken to investigate the changes in the cerebellum of newborns of pinealectomized rats subjected to experimental epilepsy during pregnancy. In our study, the rats were randomly divided into six groups: intact control group, anesthesia control group, epilepsy group, melatonin-treated epileptic group, surgical pinealectomy group, and group of melatonin treatment following pinealectomy procedure. At 1 month after pinealectomy, an acute grand mal epileptic seizure was induced by 400 IU penicillin-G administration into their intrahippocampal CA3 region during the 13th day of their pregnancy in all animals except intact control group. On the neonatal first day, pups were perfused transcardially and the cerebellums removed were processed for light microscopic and immunohistochemical studies. Normal migration and maturation were determined in the postnatal rat cerebellum in both intact control and anesthesia (ketamine-xylazine) control groups, but the morphological structure of cerebellum in the epilepsy control group corresponded to the early embryonal period. It was found that experimental epilepsy or pinealectomy procedure enhanced nestin immunoreactivity, but exogenous melatonin treatment (30 microg/100 g body weight, i.p.) following pinealectomy inhibited increased nestin expression induced by melatonin deprival in vermis region of newborn rat cerebellum (P < 0.001). Our results confirm that epileptic seizures during pregnancy may impair neurogenesis and neuronal maturation in newborns, which are more dramatic in the presence of melatonin deficiency during pregnancy, explaining more harmful effects of epileptic seizures to embryos of aged mothers. To the best of our knowledge, this is the first study reporting the effects of maternal epilepsy during pregnancy in pinealectomized rats on nestin immunoexpression in the newborn rat cerebellum.

Pinealectomy exaggerates and melatonin treatment suppresses neuroma formation of transected sciatic nerve in rats: gross morphological, histological and stereological analysis.

At present, an intensive effort for prevention of neuroma formation following peripheral nerve section continues. It has been recently suggested that surgical pinealectomy (Px) induces elevation of the collagen content in the granulation tissue of a wound, while melatonin application after Px suppresses elevation of the collagen accumulation in the tissue. The aim of the present study was to assess whether melatonin had the ability to suppress collagen production and neuroma formation following peripheral nerve transection. A total of 40 male rats (four groups of 10) were left intact (intact controls) or sham operated (sham group), were Px, or were Px and given melatonin (Px + melatonin group). All animals underwent a surgical intervention consisting of right sciatic nerve neurectomy. After 4 wk, the animals were killed following intracardiac perfusion. Gross morphology of neuroma formation in the proximal nerve segment was examined and proximal neuroma evaluated. Macroscopic and microscopic findings revealed that Px caused a proliferation of connective tissue and large neuroma formation at the proximal ends of transected nerves. Stereological analysis showed that there was a statistically significant reduction in connective tissue content of the same region in Px animals treated with melatonin (P < 0.005). The results achieved in a rodent model of sciatic nerve neuroma formation showed that there was a positive correlation between macroscopic and microscopic observations, and that melatonin enhanced axonal regeneration presumably due to its inhibitory effect on neuroma formation.