Aging changes in the retina of male albino rat: a histological, ultrastructural and immunohistochemical study

BACKGROUND

Degenerative changes caused by aging may affect the eye, especially the retina. Such changes occur as a part of normal physiological process and may be irreversible. The aim of the study was to demonstrate the influence of aging on the morphology of the retina to provide a basis to explain the pathogenesis of age-associated decline in visual acuity, scotopic and photopic sensitivity.

MATERIALS AND METHODS

Forty male albino rats were used and divided into four age groups (group I: age of cortical maturity, group II: middle-aged, group III: aged group and group IV: senile group). The rats were sacrificed, the eye balls were enucleated. Intra-vitreal injections of formalin for haematoxylin and eosin and immunohistochemical sections, glutaraldehyde for toluidine blue semithin and E/M ultra-thin sections were performed. Measurements and quantitative histomorphometric estimation of the layers of the retina were done.

RESULTS

Light microscopic examination revealed age-dependent attenuation of photoreceptor striations. Aged and senile groups presented pyknotic, widely- -spaced nuclei of the outer nuclear layer. The inner nuclear layer was thinned out to 2 or 3 cellular rows. Retinal capillaries showed progressive dilatation and congestion. Statistical analysis proved significant thinning of the retina with variable degrees of thinning of the constituting layers. Decreased arborisation with age was confirmed with quantification of synaptophysin-immunostained sections. Glial fibrillary acidic protein immunostaining revealed the picture of reactive gliosis. On the ultrastructural level, the retinal pigment epithelium exhibited major alterations with aging. Numerous phagosomes, lipofuscin and melanolipofusin granules appeared within the cells, together with exaggerated basal infoldings. The pho- toreceptor nuclei became degenerated and the perinuclear space was widened.

CONCLUSIONS

Rat retinae clearly undergo age-related morphological changes. Such changes provide a cellular base for explanation of decreased vision in humans with aging other than reflection errors. Effect of aging was not only qualitative, but also quantitative.

Can constant light exposure affect the thyroid gland in prepubertal male albino rats? Histological and ultrastructural study

BACKGROUND

Through scientific literature, there is evidence that light affects thyroid function in human, mice and rabbits. Constant light and sleep deprivation is also used as a form of human torture, as it has impact on cognitive performances. The present work was conducted to study the effect of constant light for short and long periods on the thyroid gland in the prepubertal male albino rats.

MATERIALS AND METHODS

A total of 30 prepubertal male albino rats were used. The rats separated into three groups: group I (control); group II were those rats put under steady encompassing light (24 h/day, light intensity of 600 lux) for 4 weeks; and group III were the rats maintained in constant light for 3 months. The rat thyroid gland was subjected to histological and ultrastructural examination.

RESULTS

The rats exposed to light for long durations showed disturbed architecture; the follicles exhibited back to back arrangement (signs of hypertrophy with hyperplasia), lined by multiple layers of follicular cells or were lined by vacuolated cells. Few thyroid follicles exhibited cystic hyperplasia. Congested blood capillaries were demonstrated between the follicles.

CONCLUSIONS

It can be concluded that the short-term exposure to constant light for 1 month had no apparent effect on thyroid gland tissues while longer exposure to light for 3 months had detrimental effects on the thyroid gland structure of male albino rats.

Stress-induced changes in the aged-rat adrenal cortex. Histological and histomorphometric study

BACKGROUND

Stress exposure exerts direct effects on the morphology and functionality of the adrenal cortex. In addition, ageing effects growth, differentiation, apoptosis and cellularity of the cortex. The missing data is the combined effect of stress and ageing on the adrenal cortex. The aim of this study was to demonstrate the structural changes in the adrenal cortex following the exposure to stress in the adult and aged albino rats.

MATERIALS AND METHODS

Forty rats were divided into groups I and II (adult and senile). Each group was further subdivided into subgroups a and b (control and stressed). Light and electron microscopic studies were done. Area per cent of collagen fibres (Masson's trichrome-stained sections), number of proliferating cells (optical density immunoreactivity in the Ki67 stained sections) and thickness of the three adrenal zones were also measured.

RESULTS

Lamellar separation of the capsule with subcapsular spindle cell hyperplasia and areas of ghost cells were observed in zona glomerulosa (ZG) and zona fasciculata (ZF) in group I-b. Separation and indentation of the capsule with its lamellar separation were observed in group II-a with the existence of multiple scattered degenerative foci in ZF and zona reticularis (ZR). Similar and aggressive was the architectural pattern of ZF in group II-b with the presence of areas of homogenous degeneration. The nuclei of ZG had marginated chromatin in group I-b and were pyknotic with deformed irregular outlines in group II-b. Multiple lysosomes and vacuolar degeneration mitochondria were also seen in group I-b. The nuclei of ZF were irregular with condensed marginated heterochromatin in group I-b, irregular with scattered chromatin in group II-a and indented with areas of chromatin destruction in group II-b. Mitochondria with disrupted cristae and cristolysis were also detected in group I-b. Numerous lipofuscin granules and dilated smooth endoplasmic reticulum were revealed in group II-b. The mean collagen fibre area per cent and the mean number of the proliferating cells in group II-b were significantly higher by 39% and 23%. The thickness of ZG decreased significantly by 20% in group I-b. Contrary, the thickness of both ZF and ZR increased significantly by 10% in group I-b.

CONCLUSIONS

Histological alterations occurred in the adrenal cortex in response to stress, especially when coupled with the advance of age. This was accompanied by increase in the area per cent of collagen fibres and increase in the mean number of the proliferating cells in the adrenal cortex.

The sphenopalatine foramen in man: anatomical, radiological and endoscopic study

BACKGROUND

Epistaxis is a frequent problem otorhinolaryngologists faces of in their practice. The variations of the sphenopalatine foramen (SPF) and consequ-ently the artery may be one of the major sources of such bleeding. The present work aimed to localise the site of SPF and also to illustrate its different shapes, number and any other variation.

MATERIALS AND METHODS

In the current study, 20 adult skulls of both sexes with total 40 half skulls were used in addition to 20 heads of adult living subjects of both sexes aged between 30 and 60 years examined with multislice helical com-puted tomography with 3-dimensional reconstruction of SPF. Then, examination of another ten dried skulls with endoscope was performed.

RESULTS

The number of the SPF is varied being single in nearly 80% and multiple in 20% of examined cases. The shape of the foramen also is varied; regular in 67.5% and irregular in 32.5% of all cases. The site of the foramen on the lateral nasal wall is placed in the superior meatus in most of examined skulls (62.5%) while in the rest (37.5%) they are found in the superior meatus and extending to the middle one.

CONCLUSIONS

There are variation of the number, shape and site of the SPF, and consequently of the branches of the sphenopalatine artery, and this may explain the surgical failure in management of severe epistaxis. The data obtained from the current work support the predication of more than one sphenopalatine ar-teries and gives ample knowledge on the endoscopic study of the lateral nasal wall and consequently the surgical treatment of severe epistaxis. (Folia Morphol 2018; 77, 2: 345-355).

Morphological and morphometric study of the cartilaginous framework of the dorsum and tip of the nose among Egyptian populations: a cadaveric study

BACKGROUND

Success or failure of rhinoplasty depends mainly on the awareness of the surgeon with the construction of the nasal cartilaginous framework and the knowledge of the morphology and different dimensions of these cartilages. The current study aimed at evaluation of the morphology of the nasal cartilages and to address their different measurements as well as observation of anatomical variations of these cartilages and elucidation of their implications in rhinoplasty.

MATERIALS AND METHODS

Thirty adult human cadaveric noses, males and females aged 20-70 years were used in the current study. The specimens were dissected; cartilages were exposed and examined morphologically for shape, parts and attachments. Different nasal cartilage measurements were done.

RESULTS

The examination of nasal cartilage revealed that the mean length of upper lateral cartilage was variable. The mean width and thickness were 12.8 ± 1.29 mm and 1.34 ± 0.14 mm, respectively. The mean length, width and thickness of alar cartilage were assessed. Angle of divergence was observed to be 23-44°. Statistically, there were no significant differences between genders.

CONCLUSIONS

Data obtained from this study confirmed the anatomical varia-tions of the nasal cartilages among the Egyptians and confirmed the differences with several ethnic groups. This has important surgical implications giving the attention required during different techniques in rhinoplasty in order to maintain dorsal aesthetic lines of the nose and proper respiratory function.

Morphological and radiometrical study of the human intervertebral foramina of the cervical spine

BACKGROUND

Degenerative changes of the cervical spine are an inevitable response to certain occupational status and aging processes. Compression of cervical nerve roots may result from disc degeneration, disc herniation or intervertebral foraminal stenosis. The precise and detailed anatomical knowledge of the intervertebral foramen of the cervical spine is essential for the diagnosis and management of cervical radiculopathy. The significance of the observations and findings of the present study was to elucidate the correlation between the morphology and disorders of the cervical intervertebral foramina in normal and pathological conditions especially at the level of C3-C4 to C6-C7 on both sides and in both sexes. Moreover, it will help greatly in the planning of both surgical and conservative strategies.

MATERIALS AND METHODS

In the present study, 5 formalin-fixed adult cadavers and radiological specimens of the cervical region of the vertebral column of 28 normal and 209 subjects suffering from cervical disorder from both sexes and different age groups. They subjected for morphological and radiometrical analysis.

RESULTS

All measurements of the present study of the cervical disorders in females were found to be 6% less than in males in all age groups, which is statistically significant (p < 0.01) as compared with the control group (2%). The mean intervertebral foraminal areas in the control group of C5-C6 and C6-C7 are significantly greater than those of C3-C4 and C4-C5.

CONCLUSIONS

The mean intervertebral foraminal area was greater in the lower cervical region than the upper in normal adult individuals. In pathological condition the affection of C3-C4 and C4-C5 intervertebral foramina was more due to narrower surface area. The pathology of cervical spine affecting the intervertebral foramina of female which complaint earlier than male due to narrower foramina.