Effects of postnatal exposure to static magnetic field on the development of the cerebellar granule cells

Many studies were performed to evaluate the effects of static magnetic fields [SMFs] on the processes of proliferation and migration of cerebellar cells to their final postnatal destinations. Granule cells are the most abundant interneurons in the cerebellum. Progenitors of these neurons actively proliferate during the first 2 postnatal weeks in external granular layer [EGL]. The granule cells in the EGL migrate inwards to form the internal granular layer [IGL], and the EGL disappears. So the postnatal development of the cerebellum depends on their postnatal proliferation and migration which is vulnerable to any micro-environmental insult. to evaluated the light and electron microscopic changes occurred to the cerebellar granule cells of the pups after postnatal exposure to SMF [20 mT]. Postnatal exposure to SMFs showed that there was a significant thinning in the EGL at the beginning of the study at postnatal thy 4, this significant decrease in thickness progressed in the first week. At two weeks when normally the EGL starts to disappear, it showed persistent increase in its thickness indicating delayed migration. At all ages of exposed group [P], EGL contained many apoptotic cells and some degenerated cells. IGL showed significant decrease in its cellular density till the postnatal day 15 concomitant with the period of delayed migration in the EGL. At the postnatal days 22, the cells in IGL began to regain its near normal cellular density but the IGL showed disarrangement of its crowded granule cells with absence of appearance of regular glomeruli among them with appearance of some degenerated cells among the granule cells. Many cells of the IGL also showed areas of cytoplasmic vacuolation. Postnatal exposure to SMFs produces some delay in the development and appearance of more apoptotic cells. But some of these changes in different stages of the postnatal development of the cerebellar cortex began to be less apparent with advancement of age

Effects of prenatal exposure to static magnetic field on the development of the cerebellar purkinje cells

Many studies were performed to evaluate the effects of static magnetic fields [SMFs] on the processes of proliferation and migration of cerebellar cells to their final postnatal destinations. Purkinje cell [PC] as one of the most critical station for all afferent input to the cerebellum as well as the major output from the cerebellum either direct or indirect through the other cerebellar neurons and development of Purkinje cells depends on their postnatal migration which is vulnerable to any micro-environmental insult. To evaluate the light and electron microscopic changes occurred to the cerebellar PCs of the pups after prenatal exposure to SMF [20 mT]. Prenatal exposure showed a significant decrease in the number of PCs as compared with that number in the control group throughout the time of study with appearance of some pathological changes at the cellular level obvious from the postnatal day 4 till the end of the study, as there were many apoptotic cells, few cells degenerated with astrocytosis near the Purkinje cells with large cytoplasmic vacuoles inside the cells and many cells became atrophied cells. The prenatal exposure to static magnetic field led to decrease ability of the proliferation, delay in the development and appearance of some degenerative changes in different stages of the postnatal development of the cerebellar cortex and these changes persisted till the adult life

Light and electron microscopic study on the effect of colchicine on skeletal muscle of albino rat

Colchicine has anti-inflammatory action, thus it is used in the treatment of gouty arthritis, familial Mediterranean fever, amyloidosis, dermatosis and some cutaneous diseases. This study was designed to investigate the effect of colchicine on skeletal muscle of the albino rat. Twenty eight adult rats [20 females and 8 males] were used. Only 12 females were allowed to get pregnant. All the animals were divided into 5 groups. The 1st group contained the control offsprings of 4 pregnant rats. The 2nd group contained the nontreated offsprings of 4 treated pregnant rats. Each pregnant rat was treated daily by a single oral dose [0.03 mg] of colchicine for 5 successive weeks, from the first day of pregnancy up to the end of the 2nd week after delivery.The 3rd group, contained treated offsprings of non treated four mothers. Each offspring was treated daily by a single oral dose [0.003 mg] of colchicine for 5 successive weeks from the beginning of the 2nd week up to the end of the 6th week of post natal life. The 4th group contained 8 control adult rats [4 males and 4 females]. The 5th group contained 8 treated adult rats [4 males and 4 females]. Each rat was treated by a daily oral dose [0.03 mg] of colchicine for 5 successive weeks. At the end of the determined period of the experiment, the gastrocnemius muscles of all groups were collected and were prepared for light and electronmicroscopic study- Light microscopic examination of all treated groups displayed widening of the intercellular spaces with shrinkage and disarray of the muscle fibres. Some myofibers in the 2nd and 3rd groups comprised degenerated nuclei. Moreover, all treated groups exhibited marked reduction of the collagenous supporting tissue. Under the electron microscope, the 2nd group revealed severe ultrastructural changes, while the 3rd group revealed marked changes. However, the 5th group revealed moderate changes. In all treated groups there was irregularity of the sarcolemmal membrane, disorientation and disorganization of the muscle fibers with focal areas of myofilaments loss or fragmentation. Mitochondrial degeneration, electron dense bodies and increased glycogen granules were also observed. The tubular system were either dilated or disrupted. Moreover, vacuolar myopathy due to the presence of the autophagic vacuoles was the characteristic myopathetic changes induced by colchicine. Lysosomes and streaming or degeneration of the Z bands were also regarded. Furthermore other myotoxic changes were only recognized in the 2nd and 3rd groups. These changes included loss of cross striations of myofibrils, loss of the sarcomeric structure and the presence of large fat globules in the sarcoplasm. In addition, lacking of most of the myofibrils and its replacement by granular pattern was only observed in the 2nd group

Clinico-pathological observations and ultra-structural alterations of nasal mucosa after cessation of airflow light and electron microscopic study of laryngectomy patients

The effect of the airflow cessation on the human nasal mucosa can be studied conveniently in the laryngectomy patients. Twenty-one of laryngectomized patients and 10 apparently healthy adults served as controls were rhinoscopically examined. By time, the nasal mucosa became thinner and its color changed. Mucociliary clearance showed many variations following surgery when compared with control group. Light and transmission electron microscopic examination of nasal mucosal specimens showed significant changes in the respiratory lining of the nose. The results of this study concluded that the airflow changes have effects on nasal mucous structural and function