Comparative histological study of human adult cervical and lumbar intervertebral discs and its relation to functions and diseases

The intervertebral discs are the major structural links between adjacent vertebrae. They serve to allow greater movement and compression between vertebral bodies. However, there is regional difference in disc structure and pathology relative to different mechanical stresses and load bearing. Comparing the histological structure of human cervical and lumbar intervertebral discs at adult age to analyze the extent of variations in structure between these regions and its relation to their functions and diseases. [12] IVDs: [4] C3C4, [4] L4L5 and [4] L5S1 and adjacent bony vertebrae were removed from each of 12 adult male and female humans at autopsy. The discs and vertebrae were processed for paraffin sections and stained by haematoxylin and eosin, trichrome, orcein and safranin stains. Histomorphometric study and statistical analysis were conducted. L4-L5, L5-S1 IVDs presented less collagen and more elastic fibers in posterior region of annulus fibrosus than anterior region, peripheral regions were thicker than central one of lumbar end plate. The annulus fibrosus invading nucleus pulposus and dividing it but at cervical level invading without dividing it. Safranin reaction was positive and much higher in cervical than in lumbar annulus fibrosus. The reaction was much higher in lumbar than in cervical nucleus pulposus. There are significant differences in collagen, elastic fibers and heights of cervical and lumbar discs. There are histological differences of human adult intervertebral discs in cervical and lumber regions which may affect their mechanical and physiologic functions and provide a better understanding of the external factors causing spinal disorders and enable the best method to be applied to the patients both at the diagnosis and the treatment stage

histological study on the effect of prenatal and postnatal administration of monosodium glutamate on the developing renal cortex of male albino rats

Monosodium glutamate [MSG] is a widely used flavour enhancer. Its use in high concentration could affect vital functions, including those of the kidney. The present study is concerned with evaluation of the effect of prenatal and postnatal MSG administration on the developing male albino rat renal cortex. Twenty pregnant female albino rats were divided into two equal groups: group I [control] and group II [treated]. In group II, MSG was administered orally at a dose of 2 mg/kg/day from the 12th day of gestation until the 21st day postnatally. After delivery, the offspring of both groups were sacrificed at the newborn stage, at 3 weeks and at 3 months. Kidney specimens were processed for examination by light and scanning electron microscopy. Maternal MSG administration affected both the renal glomeruli and tubules of the offspring. In the newborn stage, the glomeruli at the subcapsular zone appeared immature and crowded. The foot processes showed apparent elongation and disruption of their interdigitations. In weaned rats, apparent widening of Bowman's space in some glomeruli, detachment of podocytes and effacement of foot processes were noticed. In adult rats, the glomeruli showed hypercellularity with apparent elongation and fusion of the foot processes. The renal tubules at the different ages studied showed degenerative changes with sloughs inside the lumen of some tubules accompanied by proliferative changes. The proximal tubules showed partial loss of the brush border. MSG causes a delay in the development of glomeruli. Some glomeruli showed hypercellularity with affection of podocytes, which makes the glomeruli liable to glomerulosclerosis

Effect of ethanol administration on thyroid gland of adult albino rat: histological and steriological study

Excessive consumption of ethanol is well known to cause many harmful health effects, involving damage to various organs and systems. The effect of continuous administration of 10% ethanol, the only drinking fluid for eight weeks on the structure of the gland were studied. Ten male albino rats Wistar strain of ten weeks old and 250 gm initial body weight were used. The animals were randomly divided into two groups. One group was received 10% ethanol as the only drinking fluid [ad-libitum], for eight weeks. The second group drank distilled water free of ethanol, and served as control. Thyroid lobes were collected and immediately fixed. Fixation was done in formaldehyde 10% [for paraffin section] and gluteraldehyde 5% for semithin sections, for 24 hours for both. Paraffin sections were cut at 7 micro/m and routinely were stained with hematoxylin and eosin [Hx and E] for morphological examination by a light microscope, and others were stained by Van Gisson stain for the reticular fibres. Toluidine blue stain was done for the semithin sections [0.5 micro m]. Stereological techniques were done to estimate the volume proportion of the reticular fibres and fibrous element relative to total glandular tissue of both control and treated animals using the point counting technique. Also the thickness of the follicular epithelium was measured. Exposure to ethanol results in changes in the histology and morphometry of the thyroid. Changes were in the form of desquamation of the lining epithelium in some follicles, increased thickness of the glandular epithelium, increased amount of fibrous tissues between the follicles. Increased number of dilated blood vessels in the thyroid gland of the rats exposed to ethanol. Our study seems to indicate that excessive consumption of ethanol can affect the structure of the thyroid gland

Effects of medroxy-progesterone administration on testicular interstitial tissue of adult albino rat

The present work was carried out to study the effect of a single hormone, progesterone, as a method of controlling fertility in male rats. Histological and ultrastructural changes in the testicular interstitial tissue were evaluated as a result of progesterone administration. A total number of thirty adult albino rats [4 months of age] were used in this work Animals were classified into three groups, control treated, and rehabilitated groups. The progesterone is now widely used as a method of contraception in females, and under trial for contraception in males. A dose of 150 mg of medroxy progesterone was given for each experimental animal as 5 mg/day intramuscularly for one month. The rats were scarified on day after period of administration, testis were weighed and then prepared for semi -thin and ultrastructural examinations. The results of this work revealed that the applied regimen showed histological changes in the form of shrinkage and degeneration of the interstitial tissue with empty spaces. The Leydig cells are also shrunken and degenerated Also peritubular myoid cells are shrunken with thin basement membrane. Blood vessels showed narrowing and thin walled Ultrastructurally, the leydig cells showed nuclear irregularity with disturbed chromatin distribution. Degenerated vacuoles and scanty cell organelles are also noticed. In rehabilitated animals some of these changes retained to the more or less normality with some healthy leydig cells and also, more or less normal interstitial vascularity could be seen. These Promising results after rehabilitation in addition to prolongation of period of recovery may retain more healthy interstitum and reversibility of these changes could be reached

Teratogenic effects of the organophosphate insecticide, malathion, on the skeleton of developing chick embryo gross morphological study

The objective of this study was to document teratogenicity observed in chick embryos following administration of insecticide malathion in a dose of 2mg in 0.1 ml corn oil, and to suggest reasonable explanations for these anomalies. A total number of 300 eggs of Gallus domesticus species were used. After 48 hours of incubation eggs were divided into 5 groups, of 60 eggs each. The individual groups were subdivided into control [20], and treated [40] eggs. The control eggs were injected with 0.1 ml of corn oil, while the treated eggs were injected with 0.1 ml of corn oil in which 2 mg of malathion were dissolved. Eggs of both control and treated groups were examined at the 5[th], 7[th], 10[th], 14[th] and 18[th] days of incubation, for weight, mortality and morbidity, external malformations and body measurements. Embryos were prepared for skeletal examination with Alizarin red stain and Victoria blue stain. It's observed from the present study that lethality; external malformations and growth retardation, are characteristic features for malathion toxicity in chick embryo. It is observed that, malathion mortality is more frequent in higher age groups [14[th] and 18[th] days of incubation] while teratogenicity is more frequent in younger age groups [5[th] and 7[th] day of incubation]. Significant loss of weight in the treated groups is also observed. The characteristic external malformations were in the form of short lower peak, parrot beak, short neck, wry neck, micromelia of both fore limbs and hind limbs. In addition, tibiotarsal angulations and claw toes were also observed. Abnormal feather distribution, persistence of mesencephalic bulge, eye anomalies and visceral herniation could also be detected. It is concluded from this study that malathion injection is teratogenc in chick embryo when given in the 2[nd] day of incubation. The lethality detected in older age groups could be explained to be secondary to marked teratogenicity in vital organs such as heart [congestive heart failure] or neural tube defects. The toxicity of malathion on developing chick embryo could be explained by its anticholinesterase action or its suppressive effect on nicotinamid dinucleotide [NAD] levels. Also, its genotoxicity or mutagenicity could not be excluded