Gross, Light and Scanning Electron Microscopic Studies on the Ampulla Ductus Deferentis of Dromedary Camel with Special Reference to its Seasonal Variations

The morphological structure and morphometrical features of the ampulla ductus deferens of the adult camels were studied by light and scanning electron microscopy to get better understand with its seasonal variations. The wall of ampulla was composed of mucosa, submucosa, muscularis and serosa or adventitia. It was lined by pseudostratified columnar epithelium containing intraepithelial glands. The lamina propria and tunica submucosa formed together the thickest part of the ampullary wall. The ampullary glands were branched tubulo-alveolar, with diverticulae-like appearance and occupied mostly the lamina propria- submucosa. Each gland consisted of peripheral wide and central narrow alveoli that were lined by simple low columnar or cuboidal epithelium and mostly contained spermatozoa and secretory materials. The gland opened in the ampullary lumen by short tubule, which was lined by pseudostratified columnar epithelium. Histochemically, the epithelial cells reacted positively to Alcian blue, PAS and sudan black stains and negatively to the Best's carmine stain, indicating the presence of the acid, neutral glycoprotein and fatty droplet, as well as absence of the glycogen. Morphometrically, the height of the luminal and glandular epithelia, thickness of the lamina propria- submucosa and ratio of the glandular to the connective tissue showed seasonal variations. The height of the luminal and glandular epithelia reached their maximum values in winter and decreased gradually throughout spring and recorded the lowest values in summer. Scanning electron microscopy revealed various shaped openings in the luminal surface of the ampulla. The cells apices were studded with short microvilli and many secretory granules or vesicles. The ampullary glands appeared as a network of diverticulae-like structure, which occupied mostly the lamina propria-submuosa. The cells apices of the glandular epithelium were stereo-ciliated, microvilliated cells or showed central bleb-like protrusion surrounded by thin long microvilli. The glandular alveoli contained spermatozoa and secretory materials. In conclusion, the camel ampulla ductus deferentis performs a storage function in addition to its secretory one, where both are subjecting to seasonal variations

Morphological Studies on the Upper Beak of Turkey (Meleagris gallopavo)

This study was carried out to provide a detailed description about the upper beak of turkey, regarding its gross anatomical, light and scanning electron microscopic morphology. The upper beak extends in a hook like infront of the lower beak. It measures 53.80 mm long. The height and width of the upper beak increase caudalwards. SEM shows that the tip and the lateral sides of the upper beak are covered with numerous flakes of keratin. At the free tip of the beak, these keratinized flakes have an irregular appearance which may be due to desquamation of the epithelium during manipulation of foods. Immediately in front of the angle of the mouth, the lateral edge of the upper beak is characterized by the presence of transverse furrows which giving it a serrated appearance. The upper beak of the turkey consists of a bony support covered by dermal and epidermal layers

Palate of turkey (Meleagris gallopavo): Gross Anatomical, Light and Scanning Electron Microscopical Study

This investigation aimed to determine the morphological characteristics of the palate of bronze black turkey by gross anatomy, light and scanning electron microscopy. The oral roof (palate) constitutes 87.73% of the oropharyngeal roof length, comprising two parts; rostral and caudal. The rostral part of is characterized by the presence of median palatine ridge, rostral and caudal lateral palatine ridges, narrow part of the choanal slit and three rows of palatine papillae. The median palatine ridge shows rostral continued and caudal interrupted parts. This ridge as shown by scanning electron microscopy (SEM) bears 4-5 transverse furrows at the level of the beginning of the caudal lateral palatine ridges. Numerous Periodic Acid-Schiff (PAS)-positive compound tubular mucous maxillary, palatine and sphenopterygoid salivary glands are distributed in the mucosa of the palate. From all above mentioned, it's clear that the palate in turkey reveals some different anatomical features in compared with that of the other birds

Gross Anatomical, Light and Scanning Electron Microscopic Studies on the Pharyngeal Roof of Turkey (Meleagris gallopavo): Comparative Study

The present study was carried out to investigate the histomorphological features of the turkey's pharyngeal roof using light and scanning electron microscopy. Studied parts from the roof of the turkey's pharynx were processed and stained by convential stains to illustrate the mucosa, salivary glands, and connective tissue infiltration. Also, Scanning electron investigations were applied on pharyngeal papillae and pharyngeoseophageal junction. Grossly, the pharyngeal roof was shown to constitute about 12.27% of the oropharyngeal roof length, continue rostrally with the oral roof at the level located between the choanal and infundibular slits, and terminate caudally at the pharyngeoesophageal junction, demarcated by a transverse row of caudally directed conical papillae. Numerous different sized and shaped caudally directed pharyngeal papillae were distributed in the roof of the pharynx. Histologically, the pharyngeal mucosa demonstrated pharyngeal folds, intraepithelial mucous glands, abundant lymphoid infiltration and lymphatic nodules, in addition to intraepithelial sensory corpuscles. Numerous compound tubular mucous sphenopterygoid salivary glands were observed in the mucosa of the pharyngeal roof. This study in conclusion provided comprehensive information on the structure of the pharyngeal roof of the turkey, comparing these findings with those of other birds

Morphological and ultrasonographic characterization of the three zones of supratesticular region of testicular artery in Assaf rams

[EN] To fully understand the histological, morphometrical and heamodynamic variations of different supratesticular artery regions, 20 mature and healthy Assaf rams were examined through ultrasound and morphological studies. The testicular artery images of the spermatic cord as shown by B-mode analysis indicated a tortuous pattern along its course toward the testis, although it tends to be less tortuous close to the inguinal ring. Doppler velocimetric values showed a progressive decline in flow velocity, in addition to pulsatility and vessel resistivity when entering the testis, where there were significant differences in the Doppler indices and velocities among the different regions. The peak systolic velocity, pulsatility index and resistive index were higher in the proximal supratesticular artery region, followed by middle and distal ones, while the end diastolic velocity was higher in the distal supratesticular region. The total arterial blood flow and total arterial blood flow rate reported a progressive and significant increase along the testicular cord until entering the testis. Histological examination revealed presence of vasa vasorum in the tunica adventitia, with their diameter is higher in the proximal supratesticular zone than middle and distal ones. Morphometrically, the thickness of the supratesticular artery wall showed a significant decline downward toward the testis; meanwhile, the outer arterial diameter and inner luminal diameter displayed a significant increase distally. The expression of alpha smooth muscle actin and vimentin was higher in the tunica media of the proximal supratesticular artery zone than in middle and distal ones.SIThe authors acknowledge the staff members and technicians of Comparative Anatomy and Pathology Department, and Animal Medicine and Surgery Department, Faculty of Veterinary Medicine, León University, Spain, and specially Professor P de Paz for their great help in the practical and laboratory parts of this study. Many thanks are extended to staff member of Anatomy and Embryology Department, Faculty of Veterinary Medicine, Sohag University, for their help with histological and morphometrical analyses. We are thankful and grateful for European Union for the financial support of this study through the project (ERASMUS+ KA107 2019/2020). This work was financially supported by the Junta de Castilla y León (LE253P18) and MINECO (AGL2017-83098-R) project and the University of León, and also by Sohag University, Egypt.This article was funded by Ministerio de Economía, Industria y Competitividad, Gobierno de España (AGL2017-83098-R) and Junta de Castilla y León (LE253P18)

The evolving SARS-CoV-2 epidemic in Africa: Insights from rapidly expanding genomic surveillance

INTRODUCTION Investment in Africa over the past year with regard to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) sequencing has led to a massive increase in the number of sequences, which, to date, exceeds 100,000 sequences generated to track the pandemic on the continent. These sequences have profoundly affected how public health officials in Africa have navigated the COVID-19 pandemic. RATIONALE We demonstrate how the first 100,000 SARS-CoV-2 sequences from Africa have helped monitor the epidemic on the continent, how genomic surveillance expanded over the course of the pandemic, and how we adapted our sequencing methods to deal with an evolving virus. Finally, we also examine how viral lineages have spread across the continent in a phylogeographic framework to gain insights into the underlying temporal and spatial transmission dynamics for several variants of concern (VOCs). RESULTS Our results indicate that the number of countries in Africa that can sequence the virus within their own borders is growing and that this is coupled with a shorter turnaround time from the time of sampling to sequence submission. Ongoing evolution necessitated the continual updating of primer sets, and, as a result, eight primer sets were designed in tandem with viral evolution and used to ensure effective sequencing of the virus. The pandemic unfolded through multiple waves of infection that were each driven by distinct genetic lineages, with B.1-like ancestral strains associated with the first pandemic wave of infections in 2020. Successive waves on the continent were fueled by different VOCs, with Alpha and Beta cocirculating in distinct spatial patterns during the second wave and Delta and Omicron affecting the whole continent during the third and fourth waves, respectively. Phylogeographic reconstruction points toward distinct differences in viral importation and exportation patterns associated with the Alpha, Beta, Delta, and Omicron variants and subvariants, when considering both Africa versus the rest of the world and viral dissemination within the continent. Our epidemiological and phylogenetic inferences therefore underscore the heterogeneous nature of the pandemic on the continent and highlight key insights and challenges, for instance, recognizing the limitations of low testing proportions. We also highlight the early warning capacity that genomic surveillance in Africa has had for the rest of the world with the detection of new lineages and variants, the most recent being the characterization of various Omicron subvariants. CONCLUSION Sustained investment for diagnostics and genomic surveillance in Africa is needed as the virus continues to evolve. This is important not only to help combat SARS-CoV-2 on the continent but also because it can be used as a platform to help address the many emerging and reemerging infectious disease threats in Africa. In particular, capacity building for local sequencing within countries or within the continent should be prioritized because this is generally associated with shorter turnaround times, providing the most benefit to local public health authorities tasked with pandemic response and mitigation and allowing for the fastest reaction to localized outbreaks. These investments are crucial for pandemic preparedness and response and will serve the health of the continent well into the 21st century