Effects of spermine and the passive avoidance learning (PAL) following cerebral ischemia in chicks: Association with neuroprotection of pyramidal cells.

The aim of this study is to investigate the effects of spermine and the passive avoidance learning on hippocampus following transient cerebral ischemia in the chicks. The study is composed of the pure control (CG), sham (SG) and experimental groups (n=20). Experimental groups (ischemia group, IG and ischemia-spermine group, ISG) were exposed to ischemia for 20min whereas the SG was exposed to sham operation and CG group was not exposed to any operation. Passive avoidance learning (PAL) was applied to the half number of the subjects in each group. Both before and after 7days from the ischemia, operated animals were taken to PAL and then they were sacrificed. Total numbers of neurons in the hippocampus were stereologically estimated using Cresyl violet stained sections. We detected that number of neurons was increased following PAL and especially spermine treatment. According to our results, we suggested that spermine may reduce the deleterious effects of the ischemia by causing to increase in the neuronal number and so, it may be slightly supportive to the PAL.

The Use of Sequential VEGF- and BMP2-Releasing Biodegradable Scaffolds in Rabbit Mandibular Defects.

PURPOSE: Promising developments have materialized in reconstructive surgical procedures with the applications of tissue engineering. In our study, we used tissue scaffolds fabricated from polylactic acid-polyethylene glycol (PLLA-PEG) copolymers to ensure different release rates of selective growth factors recombinant human bone morphogenetic protein 2 [rhBMP-2] and vascular endothelial growth factor (rhVEGF165) in the repair of mandibular bone defects. MATERIALS AND METHODS: In our experimental study, 54 New Zealand rabbits were used. The rabbits were separated into 4 groups: group I (control group), PLLA-PEG scaffold only; group II, PLLA-PEG scaffold plus rhBMP-2 application; group III, PLLA-PEG scaffold plus VEGF165 application; and group IV, PLLA-PEG scaffold plus rhBMP-2 and VEGF165 applications. The rabbits were killed at 4 and 8 weeks postoperatively, and histopathologic and immunohistochemical assessments were performed. RESULTS: The greatest bone volume was observed in rhBMP-2-containing groups, the greatest vessel volume was observed in VEGF165-containing groups; however, the scaffold containing rhBMP-2 and VEGF165 provided the best outcomes in conjunction with increased remodeling of the new bone. CONCLUSIONS: The use of polymer tissue scaffolds that release rhVEGF165 and rhBMP-2 in coordination and mimic the natural healing process in the regeneration of especially complex tissues, such as bone, is a promising treatment alternative in the field of reconstructive surgery.

Controversies on electromagnetic field exposure and the nervous systems of children.

This paper reviewed possible health effects from exposure to low levels of electromagnetic field (EMF) in children, arising from electrical power sources and mobile phones. Overall, the information about effects on developmental processes and cognitive functions is insufficient and further research on children and adolescents is critically needed. New research approaches are required focused on the effects on the developmental processes of children exposed to electromagnetic fields, using consistent protocols. When the current data were considered in detail, it was noted that children's unique vulnerabilities make them more sensitive to EMFs emitted by electronics and wireless devices, as compared to adults. Some experimental research shows a neurological impact and exposure in humans may lead to the cognitive and behavioral impairments. Because of the proliferation of wireless devices, public awareness of these dangers now is important to safeguard children's future healthy brain development.

Effects of melatonin on diclofenac sodium treated rat kidney: a stereological and histopathological study.

OBJECTIVE: In this study, we aimed to investigate the effect of diclofenac sodium (DS) and melatonin (MEL) on kidney of the prenatally administered rats. MATERIALS AND METHODS: Pregnant rats were divided into the control, physiological saline, DS, and DS + MEL groups. All injections were given beginning from the 5th day after mating to the 15th day of the pregnancy. Physical dissector and Cavalieri principle were used to estimate the numerical density and total number of glomeruli and the volumetric parameters of kidney, respectively. RESULTS: Our stereological results indicated that DS application during the pregnancy lead to decrease in the mean volume, numerical density, and total number of the glomeruli (p < 0.05). In addition, we determined that usage of the MEL with the DS caused increases in the mean volume, numerical density, and total number of the glomeruli (p < 0.05). So, there was no significant difference in terms of the any parameter between the CONT and DS + MEL groups (p > 0.05). Light microscopic investigation showed congestion in blood vessels and shrinkage of the Bowman's space in the DS group. Moreover, there was degeneration in nephrons including glomerulosclerosis and tubular defects, and an increase in the connective tissue in the kidneys of the DS-treated group. However, usage of the MEL with the DS caused preventing of these pathological alterations in the kidney. DISCUSSION: We suggested that DS might lead to adverse effects in the kidneys of the rats that are prenatally subjected to this drug. Fortunately, these adverse effects can be prevented by the melatonin supplementation.

Effects of prenatal 900 MHz electromagnetic field exposures on the histology of rat kidney.

PURPOSE: To research the harmful effects of prenatal exposure of 900 megahertz (MHz) electromagnetic field (EMF) on kidneys of four-week-old male rats and to determine protective effects of melatonin (MEL) and omega-3 (ω-3). MATERIALS AND METHODS: Twenty-one Wistar albino rats were randomly placed into seven groups as follows: Control (Cont), Sham, MEL, ω-3, EMF, EMF+ MEL and EMF+ω-3. After mating, three groups (EMF, EMF+ MEL, EMF+ ω-3) were exposed to an EMF. In the fourth week subsequent to parturition, six rats were randomly chosen from each group. Mean volume of kidneys and renal cortices, the total number of glomeruli and basic histological structure of kidney were evaluated by stereological and light microscopical methods, respectively. RESULTS: Stereological results determined the mean volume of the kidneys and cortices were significantly increased in EMF-exposed groups compared to the Cont group. However, EMF-unexposed groups were not significantly modified compared to the Cont group. Additionally, the total number of glomeruli was significantly higher in EMF-unexposed groups compared to the Cont group. Alternatively, the number of glomeruli in EMF-exposed groups was decreased compared to the Cont group. CONCLUSIONS: Prenatal exposure of rat kidneys to 900 MHz EMF resulted in increased total kidney volume and decreased the numbers of glomeruli. Moreover, MEL and ω-3 prevented adverse effects of EMF on the kidneys.

Chronic treatment of haloperidol induces pathological changes in striatal neurons of guinea pigs: a light and electron microscopical study.

In the present work, we investigated whether there would be any change in histological structure of striatal neurons after haloperidol applications at different doses. Adult male guinea pigs were treated once-daily with saline (group 4, control) or haloperidol during 6 weeks, and the dose was 1, 2, or 3 mg/kg (groups 1, 2, and 3, respectively). After treatment, all animals were anesthetized and striata were dissected and examined. When striata were evaluated histologically, dark neurons and some degenerating striatal neurons had distinctive morphological changes consistent with cell death, including reduced neuronal size with nuclear and cytoplasmic shrinkage. Also, in sections of striata in groups 1 and 2, but not in group 3, more glial cells were observed than in those of the control group. In all treated groups, fibrous content of intersititium was paralelly increased by increasing dose. Ultrastructural investigation of striatal neurons in haloperidol-treated rats showed notched nuclei and many lysosomes. Moreover, degeneration of myelin, scarce microglial macrophages, expansion of nuclear intermembranous space, degenerated mitochondria, and vacuoles were found. Also, cytoplasmic swelling, lysosomes, and apoptotic bodies were present. These results suggest that haloperidol treatment may lead to damage in neurons via the necrotic process in both low- and high-dose applications.

Does haloperidol have side effects on histological and stereological structure of the rat kidneys?

Haloperidol, a typical antipsychotic, is the most commonly prescribed medication for the treatment of mental health problems such as agitation and psychosis. We attempted to determine the effects of haloperidol treatment on the kidneys of female rats. In addition, we aimed to estimate the numerical density, total number, and height of renal glomeruli and the volume and volumetric fractions of the cortex, medulla, and whole kidneys, and tried to determine whether there was a change in these stereological parameters depending on haloperidol treatment. Both the qualitative and quantitative histological features of the kidney samples were analyzed with conventional histopathological and modern stereological methods at the light microscopic level. The total number of glomeruli and numerical density of glomerulus in the haloperidol-treated groups was not changed by increasing the dose in comparison to the control group. The mean height of the glomerulus significantly increased, especially in low-dose groups. In the haloperidol-treated groups, the volumetric fractions of the cortex to the whole kidney of the rats were significantly decreased by increasing the dose. The volumetric fractions of the medulla to the whole kidney of the rats were increased significantly in parallel by the given dose. In addition, we present quantitative findings showing that haloperidol is associated with many alterations in rat kidneys. It was shown that haloperidol may lead to undesirable changes in the kidney after chronic treatment with especially high doses.

Number of axons in the right and left optic nerves of right-pawed and left-pawed rats: a stereologic study.

OBJECTIVE: To compare the number of axons in the right and left optic nerves of right- and left-pawed rats. STUDY DESIGN: In this study, optic nerve samples were obtained from right- and left-pawed rats and axon numbers of optic nerves and vice versa were stereologically and histologically evaluated. RESULTS: In the right-pawed rats, more axons were found in the right optic nerve than in the left optic nerve, and left-pawed rats had more axons in the left optic nerve than in the right optic nerve. CONCLUSION: The paw preference is associated with eye dominance and the number of axons in the ipsilateral optic nerve.

The protective effect of dehydroepiandrosterone on ovarian tissues after torsion-detorsion injury: a stereological and histopathological study.

OBJECTIVE: Ovarian torsion is a rare problem in pre-pubescent girls that must be included in the differential diagnosis of patients with abdominal or pelvic pain. Current advice for treatment to support ovary preservation considers the macroscopic appearance of the ovary, but this is not a reliable indicator of the degree of injury in cases of ovarian torsion. The aim of this study was to determine the effects of dehydroepiandrosterone (DHEA) treatment on the rat ovary after torsion-detorsion injury using a histopathological approach and stereological methods. MATERIALS AND METHODS: Fifteen adult female Sprague Dawley rats were divided into three groups: sham operated (Control; n=5), torsion-detorsion with saline (Saline; n = 5), and torsion-detorsion with DHEA (DHEA; n = 5). Rats in the sham-operated group underwent a surgical procedure similar to the other groups, but the adnexa were not torsioned. The DHEA group was injected intraperitoneally 3 hours before detorsion and saline was administered to the saline group. After 24 h of adnexal detorsion, the rats in all groups were sacrificed and the adnexa were removed. The volume of ovarian stroma and edema were estimated using the Cavalieri Principle and were applied to serial paraffin sections. Ovary sections were also evaluated histopathologically. RESULTS: The volume of ovarian edema was 35.4% lower in the saline group compared to the control group (p> 0.05). The volume of ovarian edema increased by 73.4% in the DHEA group (p<0.05). In the experimental groups, stromal volume was 41.0% higher in the saline group and 52% higher in the DHEA group in comparison to the control group. Statistically significant differences were found when comparing the volume of both ovarian edema and stroma between experimental groups (Detorsion/Saline group - Detorsion/DHEA group; p< 0.01). Histopathologically, mononuclear cell infiltration and vascular dilatation, perivascular edema and common necrotic changes were obvious in the torsion-detorsion damaged ovary. These changes were partially ameliorated by DHEA treatment. CONCLUSIONS: The present study shows that administration of DHEA has beneficial effects in the prevention of ischemia-reperfusion injuries of the ovaries.

Neuroprotective effects of methylprednisolone and hypothermia after experimental spinal cord injury: a histopathological and stereological study.

OBJECTIVE: Spinal cord injury is a common trauma among severe accidents in which the spinal cord has been severed; intravenous methylprednisolone and hypothermia are widely used in the treatment of traumatic spinal cord injuries. However, no common consensus has been reached on therapeutic approaches to prevent and reduce disability caused by spinal cord injuries. In this study, the efficacy of methylprednisolone and hypothermia treatments after experimental spinal cord injury made by dynamic weight-drop model in rabbits was investigated. MATERIALS AND METHODS: This experiment consists of three groups: injured, methylprednisolone-treated and hypothermia-treated groups. The methylprednisolone-treated group received intravenous methylprednisolone (30 mg/kg/day) immediately after spinal cord injury for three days. In the hypothermia-treated group, cold isotonic saline (5°C) was infused via a cannula into the epidural space at a rate of 10 ml/min. The temperature of the tissue was allowed to reach 25ºC, and then isotonic saline solution was given at a rate of 5 ml/min for 3 hours. Saline was given to the injured group following spinal cord injury. After 1 week of experimental injury, mid-thoracic level tissue was removed from the spinal cord for histopathological evaluation and subsequent stereological analysis. RESULTS: The volume of spinal cord segment, not only parenchyma of grey and white matter but also cavity, was estimated by the Cavalieri principle. Significant differences were seen between the injured group and methylprednisolone /hypothermia-treated groups in terms of the total volume cavity of spinal cord segment; cavity volume in the grey matter and cavity volume in the white matter. No significant differences were seen between methylprednisolone and hypothermia-treated groups in terms of the total volume cavity of spinal cord segment; cavity volume in the grey matter and cavity volume in the white matter. CONCLUSIONS: These results suggested that both methylprednisolone and hypothermia treatment are neuroprotective in preventing spinal cord tissue from tissue damage after experimental injury.

Effect of high fat diet on the volume of liver and quantitative feature of Kupffer cells in the female rat: a stereological and ultrastructural study.

BACKGROUND: The role of Kupffer cells (KCs) in nonalcoholic steatohepatitis (NASH) which is regarded as a major cause of cryptogenic cirrhosis of the liver was investigated using stereological methods and electron microscopy in the rat model. To our knowledge, there is no stereological study on the volume of liver, total number, numerical density, and nuclear height of KCs of liver in the female rat fed with a high fat diet (HFD) in the literature. METHOD: 16 female Sprague Dawley rats were randomized into HFD and control group, with HFD and standard diet for 12 weeks, respectively. In this study, two basic research methods were used to analyze the samples. One was histopathological observation at both light and electron microscopic level. The other was stereological methods that consist of Cavalieri principle for liver volume estimation and physical disector method for estimation of numerical density and total number of KCs in the liver. RESULTS: Liver volume, both mean numerical density and total number of KCs, were statistically increased in HFD rats. Ultrastructurally, a significant decrease in the mean nuclear height of KCs in HFD rats was also found. In the control group, no abnormal change was observed, but in the HFD group, some changes such as diffuse steatosis, mononuclear cell infiltration, necrosis, fibrosis, accumulation of fat droplets and intra-cytoplasmic vacuoles, and swollen mitochondria with irregular membranes were observed in the hepatocytes. CONCLUSION: The number and activity of KCs are increased significantly in NASH induced by HFD, and KCs might be involved in the pathogenesis of steatohepatitis as previously attributed as a major cause of cryptogenic cirrhosis of the liver.

Effect of a high fat diet on quantitative features of adipocytes in the omentum: an experimental, stereological and ultrastructural study.

BACKGROUND: Omental adipose tissue specimens of female rats that were fed a high fat (HF) diet were evaluated stereologically and histopathologically. To our knowledge, there is no stereological study on numerical density, nuclear height and volume of adipocytes in omental adipose tissue in the female rat fed a HF diet in the literature. METHOD: 20 female Spraque Dawley rats were used in the study. 10 of the animals were fed HF diet consisting of 30% of calories from fat for 3 months. The remaining 10 rats, the control group, were fed a normal diet. After the experimental procedure, all animals were anesthetized and omental adipose tissues in the same area were dissected and fixed for the histochemical process using a mixture of 3% glutaraldehyde and 1% osmium tetraoxide in 0.1 M phosphate buffer. After embedding of tissues in araldite CY 212, semi-thin and thin sections were cut. The semi-thin sections were stained with toluidine blue. The physical dissector counting method was used for estimation of numerical density and nuclear height of adipocytes. Cavalieri principle was used for the estimation of adipocyte volume; volume fraction approach was applied to find the volume fraction of adipose tissue components. RESULTS: The mean numerical density of adipocytes in the HF diet group was significantly higher than the control. The mean nuclear height of adipocytes was also very high in the HF diet group. The volume fraction of adipose mass was increased whereas the extracellular matrix volume fraction was reduced in the HF diet group compared to the controls. The mean volume of adipocytes in the HF diet group was also significantly higher than in the control group. At the light microscopy level, it was found that adipocytes were enlarged and gaining irregular shape in the HF diet group. Thicker basal lamina and electron dense lipid content were also found in this group at the electron microscopy level. CONCLUSION: Lipid content and number of adipocytes in the adipose tissue of HF diet rats were higher than in the controls. Thus, HF diet induces increase in body weight via both hypertrophy and hyperplasia of adipocytes.