Immunohistochemical and ultrastructural changes in rat fat tissue related to the local hCG injection.

OBJECTIVES: Recently, it has been observed that weight loss is accelerated by human chorionic gonadotropin (hCG) hormone preparation used for hypothalamic dysfunction in obesity treatment in both sexes. hCG is also used for in vitro fertilization and in treatment of hypogonadotropic hypogonadism. Our aim was to observe the ultrastructural changes caused by local injections of hCG made for purpose of weight loss and to present them to inform those receiving such therapy. MATERIALS AND METHODS: In our study, 10 obese female, 10 male obese, 10 non-obese female and 10 non-obese male rats were used. In each group, single dose of subcutaneous hCG injection has been applied to 7 rats for 5 weeks in 5 days of the week, and placebo has been applied to the remaining 3 rats. Following the injection, the tissues were evaluated morphologically, immunohistochemically and ultrastructurally. RESULTS: Leptin immunoreactivity was similar in all groups. When the adipose tissue samples were examined under electron microscope, they were observed to exhibit normal structure with organelles located around the nuclei and nucleoli, and no distinctive features were found among the groups. CONCLUSIONS: Administering hCG in addition to diet had no advantage on weight reduction in rats.

Dose-dependent immunohistochemical changes in rat cornea and retina after oral methylphenidate administration.

Methylphenidate hydrochloride (MPH), more commonly known as Ritalin, is a piperidine derivative and is the drug most often used to treat attention deficit/hyperactivity disorder, one of the most common behavioural disorders of children and young adults. The aim of this study was to investigate dose-dependent immunohistochemical Dopamine 2 receptor (D2) expression and apoptosis in the rat cornea and cornea. In this study, 27 female pre-pubertal Wistar albino rats, divided into three different dose groups (5, 10 and 20 mg/kg) and their control groups, were used. They were treated orally with methylphenidate dissolved in saline solution for 5 days per week during 3 months. At the end of the third month, after perfusion fixation, eye tissue was removed. Paraffin sections were collected for immunohistochemical and terminal deoxynucleotidyl-transferase-mediated dUTP-biotin nick end labelling assay studies. In our study, we observed that the cornea D2 receptor reactivity showed a dose-related increase after MPH treatment, especially in basal cells of the epithelium and a dose-dependent decrease in the retinal ganglion cell which was statistically meaningful. Analysis of the cornea thickness results showed no meaningful difference between groups. Apoptotic cell number showed a meaningful increase in the high dose treated group compared to the other groups of the study. The data suggest that Ritalin has degenerative effect on the important functional part of the eye, such as cornea and retina and its activating dopaminergic mechanism via similar neuronal paths, functionally and structurally, to induce morphological changes. As a result, we believe that this morphological changes negatively effecting functional organization of the affected cornea and retina.

Dose-dependent immunohistochemical and ultrastructural changes after oral methylphenidate administration in rat heart tissue.

Methylphenidate, more commonly known as Ritalin, is a piperidine derivative and is the drug most often used to treat attention deficit/hyperactivity disorder, one of the most common behavioural disorders of children and young adults. Our aims were to investigate dose-dependent immunohistochemical D2 expression and ultrastructural changes of the rat heart tissue, and to demonstrate possible toxicity of the long-term and high dose use of the methylphenidate. In this study, 27 female pre-pubertal Wistar albino rats, divided into three different dose groups (5, 10 and 20 mg/kg) and their control groups, were used. They were treated orally with methylphenidate dissolved in saline solution for 5 days/week during 3 months. At the end of the third month, after perfusion fixation, left ventricle of cardiac tissue was removed. Paraffin, semi-thin and thin sections were collected and immunohistochemical, terminal deoxynucleotidyl transferase-mediated Dig-dUTP nick end labelling assay and ultrastructural studies were performed. In conclusion, we believe that Ritalin is dose-related affecting dopaminergic system to increase heart rhythm and contraction. Thus, this drug may cause degenerative ultrastructural changes in mitochondrial path.

Age-related immunohistochemical and ultrastructural changes in rat oculomotor nerve.

During ageing process, multiple changes occur on nervous tissue composed of cells and extracellular matrix. Changes on nervous tissues are usually known as degenerative changes on axon structure and connective tissue covering the nerve such as a decrease in the number of fibre or general structural changes. For this purpose, we have studied age-dependent ultrastructural changes in the rat oculomotor nerve with electron microscopy and also demonstrated collagen structure of the neural sheaths with immunohistochemical techniques. This study was conducted in Gazi University Faculty of Medicine, Department of Anatomy with a total of nine Wistar albino rats. We observed strong collagen type I immunoreactivity in endoneurium and slight to moderate reactivity in fibroblast cytoplasm in 3-month- and 12-month-old groups and mild reactivity in 24-month-old group. Collagen type IV immunoreactivity was stronger in endoneurium and perineurium in the 3-month- and 12-month-old groups compared with collagen type I and fibroblast cytoplasm showed a very strong reactivity. On the other hand, in the 24-month-old group, there was slight reactivity in endoneurium and a strong reactivity in perineurium. NGF staining showed moderate to strong reactivity on Schwann cells of the 3-month-old group. The immunoreactivity decreased in the 12-month- and 24-month-old groups. In the 3-month-old rat group, Schwann cell cytoplasm, mitochondrial structure and neurofilaments were normal. In the 12-month-old group, there were no changes in organelle distribution, mitochondrial structure and neurofilaments, but there was an increase in the connective tissue. An inconsiderable number of degenerated myelinated nerves were observed. We detected an important decrease in the collagen type I immunoreactivity, which could suggest that the endoneurium, perineurium and epineurium are less resistant to the age-related collagen loss and that the peripheral nerve is protected by a weaker barrier in the old group. The collagen type IV immunoreactivity was significantly decreased with age. NGF synthesis decreases with age because of Schwann cell structural degeneration or for different reasons. Thus, this could explain the diminished capacity of regeneration and damage of the myelination of the peripheral nerve.

Atrophic and regenerative changes in rabbit mimic muscles after lidocaine and bupivacaine application.

Destruction and denervation atrophy in skeletal muscles caused by the injection of local anaesthetics was investigated by injecting lidocaine or bupivacaine around the rabbit facial nerve to produce facial paralysis. Animals were then sacrificed at 2, 4, 6, and 8 weeks post-injection, and changes in mimic muscle tissue were assessed at each stage by light microscopy and electron microscopy. Atrophic changes were observed at 2-6 weeks after injection, and regeneration started at 6-8 weeks. Compared to bupivacaine, lidocaine caused more dramatic atrophic changes and was associated with slower muscle regeneration.

Long-term degeneration and regeneration of the rabbit facial nerve blocked with conventional lidocaine and bupivacaine solutions.

The alterations due to the long-term degeneration and regeneration of the rabbit facial nerve were investigated. The facial nerve was blocked with conventional lidocaine and bupivacaine solutions. The rabbits were sacrificed and facial nerves were removed 2, 4, 6 and 8 weeks after the administration of normal saline, lidocaine and bupivacaine. The samples were then processed for electron microscopic observation. Degenerations were seen 2-4 weeks after the injection of normal saline, lidocaine and bupivacaine. In the normal saline group the regeneration process was observed after 6 weeks, whereas in the lidocaine and bupivacaine groups this process was first noticed after 8 weeks. In the lidocaine and bupivacaine groups, regeneration was not completed at the end of 8 weeks; however, it was faster in the bupivacaine group. Bupivacaine is therefore suggested as the drug of choice for neural blockade as it caused less damage and a faster regeneration.

Effects of trauma and pain on the acute anterior pituitary hormonal response.

The aim of this study was to compare the effects of trauma and pain on the pituitary gland so as to determine whether pain is a significant component in the general acute hormonal trauma response. Adenohypophysis of rabbits that have undergone either diffuse traumatic brain injury or pain were investigated using immunohistochemistry. The ACTH staining pattern of the pain-administered rabbits was not as strong as the head-trauma-administered group, whereas PRL staining pattern of the former group was not so weak as the later group. As a conclusion, since adrenocorticotrophic hormone and prolactin staining patterns were different in the trauma administered and pain induced groups; it may be postulated that pain alone may not be an important factor in the hormonal response to trauma.

Branching patterns of rabbit oculomotor and trochlear nerves demonstrated by Sihler's stain technique.

A modified Sihler's stain technique was used to visualize the branching patterns of oculomotor and trochlear nerves. The levator palpebrae, superior rectus, inferior rectus, medial rectus, inferior oblique, superior oblique and tensor trochlea muscles were isolated from the eyes of normal rabbits and processed using modified Sihler's technique. The distributions and terminal ramifications of the oculomotor and trochlear nerves were observed. Two distinct divisions and terminal branches of the oculomotor nerve were shown in detail together with the trochlear nerve distribution. The application of Sihler's technique enables researchers to trace nerve branching within relatively transparent muscles, whereas the nerve fibers are counterstained and clearly visible. This technique could be useful for detailed studies of the motor control of extraocular muscles.

Morphological characteristics of styloid process evaluated by computerized axial tomography.

Morphological characteristics of styloid process and ossified stylohyoid ligament and their overall relationships to age and sex were studied by using computerized axial tomography images. The styloid process and ossified stylohyoid ligaments were classified into seven groups according to their shapes and lengths. The styloid process of a length of 25-40 mm, was the most frequently encountered. The elongated styloid process was mostly seen in males. There was no overall correlation between the types of SP and sex. The progressive increase in length with age was not seen in our study.

Measurements of the carotid canal in skulls from Anatolia.

Since widespread applications of microsurgery are being employed for aneurysms, clival tumors, etc., precise knowledge of the skull base measurements has become vital, and a study of 307 adult skulls--130 female and 177 male--has been undertaken. Measurements were made between the landmarks chosen in accordance with the study of Lang in 1983 and our average values were similar to his series, being closer to his female data. There was no significant difference between the right and left sides of the skull.

Neurocranial morphology as determined by asymmetries of the skull base.

The goal of the current study was to provide an easy to use criterion to diagnose neurocranial asymmetries. An anatomical survey of the external aspect of the skull base was planned to correlate with radiological studies. In a sample of 239 skulls, variations of the angular relationship between the structures seen on a basilar view of the cranium were analysed. An anterior and a posterior transverse line were plotted with respect to the midline. Departures from 90 degrees to the midline for either of the transverse lines were less than 5 degrees in normal skulls, between 5 degrees and 7 degrees in skulls classed by independent inspection as asymmetric, and more than 7 degrees in obviously malformed skulls.

Morphological analysis of the myocardial fiber architecture of ventriculus cordis in normal and malformed human hearts.

In this study, ten normal and one malformed adult human hearts obtained from the collections of Gazi University Department of Anatomy were investigated. Muscle maceration techniques of Romeis and Torrant-Guasp have been used. In the normal heart, the superficial layer of ventricular myocardium has been detected. Then, middle layer was demonstrated by lifting up the fibers of this layer. Endocardium of ventricles was dissected and inner layer was observed. Consequently, direction of muscle fibers was examined in ventricular myocardium. Sections of muscle samples from an hypertrophied heart were prepared by routine light microscopic procedures. In the normal heart, a thin middle layer was present in right ventricle. This layer was appeared to be hypertrophied in the malformed heart.