histological study of bowman's glands in human olfactory mucosa

The histology of olfactory mucosa has been previously studied under light and electron microscope. There are marked geographical differences between Pakistan and other countries where most of the research on olfactory epithelium has been conducted. To study morphology and quantitative analysis of Bowman's glands in human olfactory mucosa in Pakistani population. An observational study. This research was done in the Anatomy Department, A M College, Rawalpindi. The duration of study was two years from January 2001 to December 2003. Enbloc specimens were obtained from 20 autopsy cases. After decalcification, they were processed, stained with haematoxylin and eosin [H and E] and seen under light microscope. The olfactory mucosa was observed in the roof, medial and lateral walls of both nasal cavities. The type of glandular tissue and its morphology was observed. The olfactory epithelium was morphologically pseudostraified columnar with a characteristic lamina propria containing numerous olfactory nerve fascicles and Bowman's glands, observed in the roof, medial and lateral walls of both nasal cavities. The secretory acini were almost circular in cross section and measured 20 to 25 micro m in diameter. The secretory cells [7-10 micro m] were pyramidal in shape, with rounded darkly stained nuclei lying in the basal half of the cells. The ducts were seen leading from the glands onto epithelial surface. Mean number of serous acini when compared in the roof, medial and lateral walls of right and left nasal cavities was statistically insignificant. Olfactory mucosa was lined with pseudostratified columnar epithelium. The secretory acini of Bowman's glands were almost circular in cross section and cells were pyramidal in shape. Mean number of serous acini when compared in the roof, medial and lateral walls of right and left nasal cavities was statistically insignificant

Dinâmica dos precursores celulares do epitélio olfatório de cães sem raça definida: um estudo imunohistoquímico e ultra-estrutural / The dynamic of precursor of the olfactory epithelium of mongrel dogs: an immunohistochemical and ultrastructural study

O epitélio olfatório apresenta um mecanismo de diferenciação em que células-tronco dão origem a células progenitoras amplificadoras, as quais expressam um gene pró-neural denominado Mammalian Achaete Scute Homolog 1 (Mash1). Estas células podem se diferenciar em receptores olfatórios. O epitélio olfatório de cães sem raça definida (3 machos de um ano e 2 fêmeas de três de idade) foi analisado por imunolocalização do antígeno nuclear de proliferação celular (PCNA) e por microscopia eletrônica de transmissão. Verificou-se marcação positiva para PCNA em células do epitélio olfatório, particularmente acima da linha da membrana basal. A ultra-estrutura do epitélio olfatório revelou células adjacentes à lâmina basal, cuja eletrodensidade assemelha-se àquelas presentes no epitélio de sustentação, reforçando a idéia da renovação das células de sustentação e dos neurônios olfatórios locais. O epitélio olfatório é composto células basais, comprometidas com sua renovação, caracterizadas através da intensa atividade mitótica, identificada pela reação positiva ao PCNA. Estes resultados sugerem que há reposição das células sustentaculares locais e do sistema através de mecanismos semelhantes.

Olfactory epithelium presents a mechanism of differentiation where stem cells give arise to amplifying progenitor cell which express Mammalian Achaete Scute Homolog 1 (Mash1). These cells can be differentiated into olfactory receptors. An immunolocalization study and ultrastructural analysis by transmission electron microscopy of olfactory epithelium of mongrel dogs were made using 3 males (one year old) and 2 females (three years old). Labeled cells with positive staining by Proliferating cell nuclear antigen (PCNA) were observed in specific areas of the olfactory epithelium, especially above the basal membrane. The ultrastructure revealed cells adjacent to the basal membrane with morphology resembling sustentacular cells, supporting the idea of renewal of sustentacular and olfactory sensorial cells. Olfactory epithelium contains basal cells committed to self-renewal, characterized by high metabolic activity, identified by positive reaction to PCNA. These results suggested the renewal of sustentacular and sensorial olfactory cells through the same pathway.

Could cinnamaldehyde be harnful? histological, cytogenetical and biochemical studies on the effects on some organs of mice

Cinnamaldehyde [CNMA] is present naturally as cinnamon tree. Because of its widespread use as fragrance additive, it was chosen for the current study. Sixty mice were divided into 6 equal groups. First three groups were control groups and the other three groups received CNMA daily, orally in three dose regimens; 1/2 LD50, 1/4 LD50 and 1/8 LD50 for 30 consecutive days, then animals were sacrificed; Liver function tests and liver tissue glutathione concentration were determined. Pancreatic specimens and olfactory mucosa were processed for both light and transmission electron microscopic studies and for scanning electron microscopic study respectively. Bone marrow cells micronucleus and chromosomal aberration tests were performed for cytogenetical study. cinnamaldehyde, in a dose related manner resulted in abnormal nuclear morphology and hyperchromatasia with increased nuclear/cytoplasinic ratio of the pancreatic acinar cells and decreased tendency for acinar formation, suggesting pancreatic acinar dysplasia. Atrophy of receptor cells of olfactory mucosa with diminished surface processes was observed in mice received 1/2 LD50 cNMA. cinnamaldehyde induced dose dependent increase in the frequency of both micro nucleated polychromatic erythrocytes and chromosomal aberrations. Significant elevation of the liver enzymes, total bilirubin and a significant reduction of the liver glutathione concentration were also detected in a dose related manner in conclusion, the considered toxicity assay parameters had shown a correlation between the administered dose of CNMA and its deteriorative effects. So, it is recommended that CNMA should not be consumed in a dose more than the acceptable daily intake and its use as flavoring agent should be kept as low as possible

Assessment of the influence of aging on the olfactory epithelium of rabbits: light and electron microscopic study

The present work was carried out to study the olfactory epithelium of rabbits in different ages and to compare age changes in the anterior and posterior areas of the olfactory mucosa. Twelve male Balady rabbits were used and they were divided equally into three age groups, group [1] 3 month old, group [2] 12 month old and group [3] 36 month old. The animals were sacrificed and the olfactory mucosa was peeled from two fixed parts in each group. Part 1: the posterior area of the roof of the nose and Part 2; the anterior upper area of the nasal septum. In group 1, the two examined parts of the olfactory mucosa were similar. The olfactory mucosa was composed of olfactory epithelium resting on a thin basal lamina and lamina propria that was characterized by the presence of Bowman's glands. The olfactory epithelium was composed of olfactory receptor neurons, supporting cells, microvillar cells that occupied the upper and the middle zones of the epithelium and basal cells in the basal zone of the epithelium. In group2, some degenerative changes were encountered in the olfactory epithelium of the two parts, but the anterior part was more affected than the posterior part. In the posterior part, the thickness of the epithelium and the cell population appeared within normal. However, in the anterior part, the thickness of the epithelium and the cell population demonstrated significant decrease. In group3, there were more degenerative changes than those of group 2. The olfactory mucosa from both parts suffered equally from severe degeneration. The most striking feature was replacement of wide areas of the olfactory epithelium with respiratory epithelium. Other areas showed many degenerated cells with significant reduction in the thickness of the epithelium. The presence of Bowman's glands was still characteristic to the olfactory epithelium. From the present study, it could be concluded that the olfactory epithelium was subjected to natural degenerative changes, which increased steadily with age. These changes began firstly in the anterior exposed areas of the epithelium and with the progress of age both areas were equally affected

Olfactory sensory-cell-number changes with age in albino mice

The area of the olfactory neuroepithelium, neuronal cell density, and the estimated total number of cells were studied in 1, 3, 4, 5 and 13 month-old Albino mice. The area increased from 363.7 mm2 for one month old to a maximum of 559 mm2 for 4 month old mice and then declined to 396.2 mm2 by the age of 13 month. Cell density increased with age and reached its maximum of 5.53 x 10 4 per mm2. at 5 moth-old. There was a 64% increase in total number of neurons from 1-4 months of age followed by a 28% decrease between 4 to 13 months of age