Effect of ofloxacin on the cartilage of the knee joint of juvenile rats

Ofloxacin is one of fluoroquinolones derivatives, which has a broad spectrum bacterial activity. It is contraindicated in children and adolescents because of its potential chondotoxicity in juveniles. However, fluoroquinolones continue to be prescribed as a drug of choice for treatment of some life threatening diseases in pediatrics. This study was conducted to examine the effect of ofloxacin on cartilage of juvenile rats by light and electron microscopes. Twenty newborn albino rats were treated with an oral dose of 900 mg/kg/day of ofloxacin for 28 days. The animals were sacrificed after the completion of the administration and the knee joints were prepared for light and electron microscopic examination. Morphometric study and statistical analysis of the results were also performed. The lesions were demonstrated in the articular cartilage of all the animals. Fissures, chondrtocyte clusters and wide area of matrix devoid of cells in the intermediate zone were observed. The surface of the premature articular cartilage of the femur was irregular. The matrix of the articular cartilage showed less staining with toluidine blue and masson trichrome. Electron microscopic results showed separation between chondrocyte cell membrane and the matrix. The chondrocytes were necrotic with pyknotic nuclei and vacuolation of their cytoplasm. There were electron dense aggregates on the cell membrane and inside the cells. The thickness of the premature articular cartilage and epiphyseal plate cartilage were significantly decreased. The numbers of chondrocytes of the premature articular cartilage and epiphyseal plate cartilage were significantly decreased. The numbers of chondrocytes of the premature articular cartilage and epiphyseal plate cartilage were significantly decreased

Effect of caffeine administration on the development of skeleton of albino rat

Caffeine, a naturally occurring central nervous system stimulant, is found in coffee and coca-based foods. Although caffeine passes readily through the placenta to the fetus, caffeine-containing products are still widely consumed during pregnancy. The present work was conducted to evaluate the effects of dietary caffeine intake during pregnancy and lactation on the skeleton of the developing rat. A total number of 20 pregnant albino rats were randomly chosen and divided into 2 groups: control group: 10 dams were given saline daily from the 10[th] day of gestation until delivery through a gastric tube, and an experimental group: 10 dams were given caffeine at a dose of 100 mg /kg/day dissolved in distilled water through a gastric tube for the same period of gestation. After normal delivery, some litters from both groups were sacrificed at postnatal day 1, and others were left for lactation and sacrificed at postnatal day 30. Samples from the lumbar region of the vertebral column, upper end of ulna and upper and lower ends of radius were taken from all groups, prepared for light microscopic examination and stained with haematoxylin and eosin and toluidine blue stains. Other samples from all groups were taken randomly and stained with alizarin red stain for gross skeletal examination. Caffeine treated groups showed delayed ossification in the developing bones including the skull, forelimb, hind limb and caudal vertebrae. Histological study of the growing ends of the long bones and vertebral bodies revealed cellular disorganization of chondrocytes especially in the hypertrophic zone, delayed ossification in between degenerating chondrocytes and less developed 2ry centers of ossification in treated animals. Also, degenerative changes were observed in the histological structure of the inter-vertebral disc in both newborn and one month old treated animals in the form of shrunken nucleus pulposus and disturbed lamellar arrangement of annulus fibrosus. These observed changes could be attributed to the direct effect of caffeine on the developing skeleton or due to some of its derivatives; theobromine or methylxanthine. The delay in the endochondral ossification may be attributed to zinc deficiency produced by the administration of caffeine