Effects of Theophylline with Methylprednisolone Combination Therapy on Biomechanics and Histopathology in Diaphragm Muscles of Rats.

The purpose of this study was to investigate the effects of theophylline and methylprednisolone on the mechanical response and histopathology of hemidiaphragm muscle in rats. In the current study, we aimed to investigate the effects of theophylline and methylprednisolone, which are frequently used in clinics and which have different effects on the respiratory system and on the biomechanics and histopathology of the diaphragm muscle. The study included four groups of rats. Group T received 1 mg/kg of intraperitoneal theophylline, group M received 2 mg/kg of intraperitoneal methylprednisolone, group TM received 1 mg/kg of intraperitoneal theophylline plus 2 mg/kg of intraperitoneal methylprednisolone, and group K received of 1 mL intraperitoneal isotonic solution (of 0.9 % NaCl). The medications were continued for 7 days in each group. The rats underwent cervical dislocation under anesthesia on the eighth day, and their diaphragm samples were extracted. The left hemidiaphragm was used for the investigation of biomechanical parameters, and the right hemidiaphragm was used for the histopathological evaluation. It was observed that the medication administered in group T increased the contraction strength and duration compared with that in group M. Additionally, the duration of semi-relaxation was prolonged in group T compared with group M. The highest contraction strength and the longest contraction period among all of the groups were observed in group TM. It was concluded that the combined use of theophylline and methylprednisolone had positive effects on the contraction strength and the durations of contraction and semi-relaxation of the diaphragm muscle. In addition, both drugs had synergistic effects on each other.

Effects of crush and axotomy on oxidative stress and some trace element levels in phrenic nerve of rats.

This study was designed to investigate the effect of crush and axotomy on oxidative stress and some trace element levels in phrenic nerve of rats. Eighteen male Wistar-albino rats were divided randomly into three groups, each consisting of 6 rats. The animals in the first group were not crushed or axotomized and served as control. Phrenic nerves of the animals in the second and third groups were crushed and axotomized, respectively. Animals in all groups were sacrificed one week after the crush or axotomy, and degenerated phrenic nerves were harvested for the determination of tissue oxidative stress and trace element levels. Lipid peroxidation product malondialdehyde and antioxidant glutathione levels increased in both crushed and axotomized phrenic nerves. The activities of antioxidant enzymes such as superoxide dismutase, catalase and glutathione peroxidase were lower in crushed and axotomized phrenic nerves than in controls. The levels of Fe, Pb, Mn, Cd and Co increased, and Mg and Cu levels decreased in crushed phrenic nerves. The levels of Fe and Mg decreased, Pb and Co levels increased in axotomized phrenic nerves. It was concluded that crushing or axotomizing the phrenic nerves may produce oxidative stress by increasing lipid peroxidation and decreasing antioxidant enzyme activities. It was also concluded that while crush to phrenic nerves causes accumulation of minerals, axotomizing phrenic nerves causes depletion of minerals in the tissues.

Effects of extracorporeal shock-wave lithotripsy directed at the parotid gland on oxidative stress parameters and some trace element levels in facial nerve of rats.

INTRODUCTION: This study was designed to assess the effect of extracorporeal shock-wave lithotripsy (ESWL) exposure of the parotid gland on oxidative stress and some trace element levels in the facial nerves of rats. METHODS: Twelve male Wistar albino rats were divided into two groups, each consisting of 6 animals. The rats in the first group served as controls. The left parotid glands of animals in the second group were treated with 1000 18-kV shock waves while anesthetized with ketamine. The animals in both groups were euthanized 72 h after the ESWL treatment, and the right facial nerve was harvested for determination of oxidant/antioxidant status and trace element levels. RESULTS: Lipid peroxidation product malondialdehyde (MDA) and antioxidant glutathione (GSH) levels increased, and the activities of antioxidant enzymes, such as superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GSH-Px), decreased in the facial nerves of ESWL-treated rats. The levels of iron, lead, manganese, and cobalt increased, and magnesium, cadmium, and copper levels decreased. CONCLUSIONS: ESWL treatment of the parotid gland may increase lipid peroxidation and decrease antioxidant enzyme activity in adjacent tissues such as the facial nerve. It also causes a decrease or increase in many mineral levels of the facial nerve, which is an undesirable condition for normal physiological function.

Effect of crush and axotomy of phrenic nerves on oxidative stress in diaphragm muscle of rats.

INTRODUCTION: In this study we investigated the effect of crush and axotomy of phrenic nerves on oxidative stress and antioxidant enzyme activities in rat diaphragm muscle. METHODS: The animals in the first group were not crushed or axotomized and served as controls. Phrenic nerves of the rats in the second and third groups were crushed or axotomized in the diaphragm muscle. RESULTS: The malondialdehyde level increased in diaphragm muscles after both crush and axotomy. The antioxidant enzymes, such as superoxide dismutase, glutathione peroxidase, carbonic anhydrase, and catalase, decreased in diaphragm muscles after both crush and axotomy. CONCLUSIONS: Crushing or axotomizing the phrenic nerves may produce oxidative stress in the diaphragm muscle of the rat by increasing lipid peroxidation and decreasing antioxidant enzyme activities.

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.

Biomechanical comparison of Achilles tenotomy and achilloplasty techniques in young rats: an experimental study.

BACKGROUND: Tendo Achillis lengthening is performed by means of Z-plasty in the classic treatment of clubfoot. In the Ponseti method for treating clubfoot, Achilles tenotomy is performed percutaneously for residual equine deformity. A randomized study was designed to compare tendon healing after tenotomy versus Z-plasty. METHODS: Thirty-six Sprague-Dawley rats were divided randomly into two groups. On the first day, while the right tendo Achillis of group 1 rats underwent tenotomy, those of group 2 rats underwent Z-plasty. Nine rats from each group were humanely killed on days 21 and 45 postoperatively. The two groups were compared with each other biomechanically and histologically. The Achilles tendons of eight rats in each group were evaluated biomechanically, and the remaining rat in each group underwent histologic evaluation. RESULTS: Mean +/- SD maximum load at rupture of the treated tendons on days 21 and 45 in the tenotomy group was 26.38 +/- 7.31 N and 47.16 +/- 15.36 N, respectively, and in the Z-plasty group was 27.37 +/- 5.20 N and 45.27 +/- 9.59 N, respectively. The biomechanical evaluation revealed no significant difference in terms of breaking forces between the two groups. The difference between breaking forces on days 21 and 45 was statistically significant for both groups. CONCLUSIONS: Tendons in the tenotomy group healed as well as those in the Z-plasty group, and Achilles tenotomy in the rat was similar to Z-plasty for Achilles tendon lengthening. Human correlation may or may not exist, but this study suggests that it should be considered and investigated.

The relationships of dog hippocampus to sex and paw preference.

Previous studies have described paw preference and asymmetry in dog brains. Electrical activity of the dorsal hippocampus also indicated the existence of hippocampal asymmetry in dogs. In the present study, the possible paw and sex-related asymmetries and right-left differences in dog hippocampus were investigated. The hippocampus was dissected and weighed. Each hippocampus was cut into slices by the slicing apparatus placed horizontally on the tissues. The volumetric measurements were performed using the formula modified from the Cavalieri principle. The present study indicated the significant sex and paw differences and no right-left asymmetry in dog hippocampi. The morphological asymmetries in normal subjects might be related to functional hippocampal asymmetries in memory or in cognitive skills.