Morphological and immunohistochemical differentiation of neuronal and glial cells of the vascular and avascular regions of the donkey's paurangiotic retina.

INTRODUCTION: Ocular diseases pose a significant health concern for donkeys. However, studies examining the microanatomy and cell populations of the donkey retina are scarce. The current study aims to describe the vascular pattern of the donkey retina and document its cellular components. METHODS: The donkey retina specimens were obtained from different retinal regions and prepared for semithin sectioning and immunohistochemistry. RESULTS: The donkey has a paurangiotic retina in which retinal vessels are confined to a narrow area around the optic disc. Glial cells coexist with the blood vessels being very numerous in the vascular region and become scanty in the avascular ones. S-100 positive astrocytes could be observed in these avascular areas. Ganglion cells are organized in a single layer with the least population existing in the peripheral retina. Acidic fibroblast growth factor (AFGF) is immunoreactive in amacrine and ganglion cells. A subpopulation of amacrine cells reacted strongly to tyrosine hydroxylase (TH), and others reacted positively to S-100 protein. Ganglion cell nuclei exhibited a strong immunoreactivity to S-100 protein as well. Furthermore, glial fibrillary acidic protein (GFAP) is used to identify Müller cells which extend their processes across the retina from the inner to the outer limiting membrane. CONCLUSIONS: In conclusion, our findings provide novel insights into the normal retinal organization. The donkey retina shows the characteristic expression of immunohistochemical markers for the major cell types. In addition, the distribution of glial cells is comparable between the vascular and avascular regions.

Temporospatial dynamics of the morphogenesis of the rabbit retina from prenatal to postnatal life: Light and electron microscopic study.

The retina consists of various cell types arranged in eight cell layers and two membranes that originate from the neuroectodermal cells. In this study, the timing of differentiation and distribution of the cellular components and the layers of the rabbit retina are investigated using light and electron microscopy and immunohistochemical techniques. There were 32 rabbit embryos and 12 rabbits used. The rabbit retina begins its prenatal development on the 10th day of gestation in the form of optic cup. The process of neuro- and gliogenesis occurs in several stages: In the first stage, the ganglionic cells are differentiated at the 15th day. The second stage includes the differentiation of Muller, amacrine, and cone cells on the 23rd day. The differentiation of bipolar, horizontal, and rod cells and formation of the inner segments of the photoreceptors consider the late stage that occurs by the 27th and 30th day of gestation. On the first week of age postnatally, the outer segments of the photoreceptors are developed. S100 protein is expressed by the Muller cells and its processes that traverse the retina from the outer to the inner limiting membranes. Calretinin is intensely labeled within the amacrine and displaced amacrine cells. Ganglionic cells exhibited moderate immunoreactivity for calretinin confined to their cytoplasm and dendrites. In conclusion, all stages of neuro- and gliogenesis of the rabbit retina occur during the embryonic period. Then, the retina continues its development postnatally by formation of the photoreceptor outer segments and all layers of the retina become established. RESEARCH HIGHLIGHTS: The aim of this study is to investigate the morphogenesis of the rabbit retina during pre- and postnatal life. The primordia of the retina could be observed in the form of the optic cup. The ganglionic cells are the first cells to differentiate, while the photoreceptor cells are the last. S100 protein is expressed by the Muller cells and its processes. Calretinin is intensely labeled in the amacrine and displaced amacrine cells and moderately expressed in the cytoplasm and dendrites of ganglionic cells.

Prenatal developmental sequences of the esophageal epithelium in the New Zealand white rabbits: Light and electron microscopic analysis.

Several morphogenetic sequences occur during esophageal development and birth defects occur due to defects in foregut morphogenesis. This work aimed to record the cellular events in the morphogenesis of rabbits' esophageal epithelium. On the 16th day of gestation, the esophageal epithelium varied from stratified ciliated columnar to stratified squamous type. The surface epithelium presented mucous cells with mucigen granules of various sizes occupying their supranuclear cytoplasm. Cytoplasmic vacuolation was evident in all layers of the esophageal epithelium at this age. On the 18th gestational day, some light cells could be detected in the middle portion of the epithelium, while others occupied the whole epithelial length. On the 21st day, mucous cells are more frequently observed at the apical esophageal part as well as at the surface epithelium. Numerous elongated dark cells could be distinguished embedded between the basal cells. On the 24th gestational day the number of the mucous cells reached its peak. Reaching the 30th gestational day, several lamellar bodies, a keratinized layer and mitotic divisions could be demonstrated, and the number of both mucous and dark cells was greatly decreased. Collectively, detection of surface mucous and dark cells together with the non-cornified surface in some regions of the rabbit esophageal epithelium at the end of gestation ensure a postnatal development to reach the adult epithelium essential to sustain the passage of the harsh raw food. Future immunohistochemical studies are recommended to investigate the components of secretions in mucous cells and functional studies to highlight the dark cells significance. RESEARCH HIGHLIGHTS: Esophageal epithelium of fetal rabbit was analyzed by light and transmission microscopy. Surface epithelium presented mucous cells with mucigen granules of various sizes. They reached their maximum number on 24th day then decreased. On the 16th day, cytoplasmic vacuolation was evident in all epithelial layers. On the 21st day, numerous elongated dark cells could be distinguished embedded between the basal cells. Before birth, several lamellar bodies, a keratinized layer and mitotic divisions could be demonstrated, and the number of both mucous and dark cells was greatly decreased.

Morphological studies on the prehatching development of the glandular stomach of Japanese quails using light, electron, and fluorescent microscopy.

The development of the glandular stomach was studied using light, electron, and fluorescent microscopy. The research used 130 Japanese quail eggs from the second to the seventeenth days of incubation.The proventriculus could be distinguished on the3rd day. Its wall consisted of four tunics: tunica mucosa, very thin tunica submucosa, tunica muscularis, and outermost tunica serosa. Mucosal folds appeared on the 8th day. The luminal epithelium was pseudostratified columnar in type and transformed into simple columnar by the 10th day. The mucosal papillae emerged on the 11th day, spiraled on the 15th day, and had a distinct whorled look by the 17th day. Two types of proventricular glands were recognized: compound tubuloalveolar and simple tubular glands. Both types were situated within the tunica mucosa. On the 4th day, the compound glands emerged as evaginations of the lining epithelium. It began to branch on the 8th day and became well established by the 11th day. The simple glands appeared on the 11th day as localized down-growths of the luminal epithelium forming solid cords. On the 15th day, many of them showed complete canalization. On the 8th day, the muscular coat was differentiated into the lamina muscularis mucosae and tunica muscularis.

Morphogenetic events influencing corneal maturation, development, and transparency: Light and electron microscopic study.

The development of the cornea is a fascinating process. Its dual origin involves the differentiation of surface ectoderm cells and the migration of mesenchymal cells of neural crest origin. This research aimed to demonstrate the morphogenesis of the rabbit cornea from fetal to postnatal life using light- and electron microscopy, and immunohistochemical analysis. There were 27 rabbit embryos and nine rabbits used. The rabbit cornea begins its prenatal development on the twelfth day of gestation. The surface ectoderm differentiates into the corneal epithelium on day 13. Intriguingly, telocytes were visible within the epithelium. The secondary stroma develops on the sixteenth day of gestation by differentiation of keratocytes. At the age of 2 weeks, the lamellae of collagenous fibers become highly organized, and the stroma becomes avascular, indicating that the cornea has become transparent. Bowman's membrane appears on day 23 of pregnancy and disappears on day 30. The Descemet's membrane appears at this time and continues to thicken postnatally. The corneal endothelium appears on the twentieth gestational day as double layer of flattened cells and becomes a single layer of cuboidal cells on day 30. The spaces between the endothelial cells resemble craters. VEGF immunohistochemical expression increases over the course of development, reaching its peak in the first week after birth before decreasing in all corneal layers and becoming negative in the stroma. In conclusion, numerous morphogenetic events contribute to corneal maturation and transparency, allowing the cornea to perform its vital functions.

Developmental morphological analyses on the preglottal salivary gland in Japanese quails (Coturnix japonica).

To understand the development of the mucous preglottal salivary gland in Coturnix japonica (Japanese quail), morphological and histochemical studies were performed on 20 healthy Japanese quail embryos (aging from 10th to 17th incubation days) and 25 healthy quail chicks (aging from 0th to 60th days). The primordia of preglottal salivary gland were observed as an epithelial bud at the early embryonic stage, which then elongated and differentiated into secretory units by the end of this stage. In Japanese quails, the preglottal salivary gland was a mucous polystomatic tubuloalveolar unpaired gland composed of two lateral portions and a middle one embedded into the submucosa of the lingual root. The gland openings accompanied taste pore (8.17 µm) of taste buds associated salivary glands type; some skeletal muscle fibers embedded among secretory lobules extended from muscle cricohyoideus at 14th day-old quail chick. Also, both herbts corpuscles and secretory motor plexus could be detected among secretory lobules. Based on our investigations, the development of the preglottal salivary gland could clearly be distinguished in the embryonic stage into pre bud and bud stages at 10th day old, cord and branching stages ended by cavitation at 11th day old, canalization stage at 13th day old, lobulation and secretory stages by the 17th day old. The secretory materials showed different histochemical reactions ended with highly alcinophilic mucous indicated highly sialomucin (acidic) content. Myoepithelial cells could be demonstrated at a 17-day old quail embryo and thereafter surrounded the secretory endpieces of the preglottal salivary gland.

A Novel Technique for Partial V-shaped Zygomatic Arch Ostectomy for Excision of Zygomatic Salivary Glands in Dogs.

The present study described a novel technique for a partial V-shaped ostectomy of the zygomatic arch (ZA) for surgical excision of the zygomatic salivary glands (ZSG) in dogs and addressed advantages and disadvantages related to this procedure. The study was conducted on 6 clinically healthy mongrel dogs. A 3-4 cm curvilinear transcutaneous incision was performed parallel to the dorsal margin of the ZA. An additional 2 cm vertical incision was performed perpendicular to the former one forming a T-shaped incision over the ZA. The skin, subcutaneous tissue, and periosteum over the ZA were dissected and reflected laterally. At 0.5 cm from the orbital ligament, a V-shaped segment from the ZA was resected using an electrical saw. The base of the V-shaped segment was 1.5 cm wide and its apex was 0.5 cm from the ventral margin of the ZA. A combination of sharp and blunt dissection was used to dissect and excise the ZSG from the surrounding tissues. The periosteal flaps were coaptated in a simple continuous pattern. The subcutaneous tissue and skin were closed as usual. The new approach was a feasible technique for the excision of the ZSGs without considerable postoperative complications in dogs. The novel V-shaped partial ostectomy of the ZA technique is reliable, satisfactory, and relatively less invasive for surgical excision of ZSGs in dogs. Further work should be conducted on clinical cases.

Onset of Appearance and Potential Significance of Telocytes in the Developing Fetal Lung.

CD34, vimentin, and vascular endothelial growth factor immunohistochemical analysis and electron microscopic tools were employed to record the initial appearance of telocytes (TCs) and stage-by-stage variations in TC localizations in the developing rabbit lung. TCs could not be identified in the primitive embryonic lung until day 18 of gestation. In the pseudoglandular lung, CD34+ TCs had been recorded under the cartilage of the main bronchus, in the wall of large-sized pulmonary vessels and large epithelial tubes. In the canalicular phase, TCs could be demonstrated in the smooth muscle layer of the bronchioles including the terminal ones. The strength of CD34 immunoreactive signals had been amplified by age until the day of parturition. Ultrastructurally, TCs consisted of a tiny body and exceptionally long telopodes (Tps). The Tp consisted of alternating thin segments (podomers) and dilated ones (podoms). The Tp sometimes branched with a dichotomous pattern. TCs interconnected in a network either by homocellular junctions with neighboring TCs or by heterocellular junctions with smooth muscle cells and alveolar cells. Collectively, early detection of TCs in pulmonary vessels suggests a potential role for TCs in their angiogenesis. For the lung tissue, TCs seem to be involved in the regulation of lung histogenesis.

Interrenal tissue, chromaffin cells and corpuscles of Stannius of Nile tilapia (Oreochromis niloticus).

Twenty-three fishes were used to study the structure and ultrastructure of interrenal tissue, chromaffin cells and corpuscles of Stannius of Nile tilapia. The interrenal tissue and chromaffin cells are present within the head kidney. The interrenal tissue is arranged in the form of highly convoluted cords, bordered by the lining endothelium of the adjacent sinusoids. It has no connective tissue capsule. The cytoplasm of the interrenal cells contains abundance of mitochondria, vacuoles and smooth endoplasmic reticulum, characterizing of steroid-producing tissues. Two types of chromaffin cells; noradrenaline (NA) cells and adrenaline cells (A) could be recognized by light microscope using chromaffin reaction, as well as by electron microscope they could be distinguished depending on the size and electron density of their granules. The corpuscles of Stannius are two in number and located on the dorsal aspect of the tail kidney. Each corpuscle is surrounded by thick connective tissue capsule. The parenchyma is divided into lobules, each of which is surrounded by distinct basal lamina and has a pseudo lumen. Depending on the presence of secretory granules and the relative abundance of cell organelles, three cell types could be recognized; granular cell, agranular cell (Type I) and agranular cell (Type II). In conclusion, the morphological and ultrastructural analysis of the endocrine tissues of the kidney of Nile tilapia has revealed only one type of interrenal cells, two types of chromaffin cells and three staged-cells of Stannius corpuscles.

Temporospatial localization of telocytes during esophageal morphogenesis in rabbit.

Telocytes (TCs) are CD34 and Vimentin positive (+) immunoreactive stromal cells with a small-sized body and several extremely long telopodes. TCs have been described to provide a mechanical support throughout the tissue by making cellular connections (homo- or hetero) to form a 3D network. Such network can transmit the intercellular signaling. Recently, TCs have been described in the esophageal wall. However, information concerning the role of these cells in esophageal organization and development is rare. Thus, we aimed to record the temporo-spatial localization pattern of TCs during esophageal morphogenesis in rabbit. Embryos and fetuses of New Zealand White rabbits (10th-30th gestational days) were collected. Using CD34 immunostaining, TCs have not been demonstrated in the wall of the developing esophagus till the end of the second third of pregnancy. On 24th gestational day, CD34+ TCs were organized in the adventitia of the esophageal wall specifically in close association with the endothelial cells lining the micro vessels. Later on 26th gestational day, CD34+TCs were additionally expressed in the sub-mucosa and in lamina propria (sub-epithelial). On 28th gestational day, additional CD34+TCs were detected among the smooth muscle bundles of the muscular layer. Reaching the last gestational day, CD34+TCs formed several sheaths in the esophageal wall namely sub epithelial sheath, sub-mucosal, muscular (circular and longitudinal) and inter-muscular sheaths and an outer adventitial one. On the other hand, vimentin immunohistochemistry revealed wider spread TCs positivity in all developmental ages. Presumptively, arrangement of CD34 and vimentin positive TCs in all layers of the developing esophageal wall hypothesizes that TC may play a potential role as a progenitor cell initially in differentiation of the epithelial and muscular precursors and finally in shaping of the various layers of the rabbit esophageal wall during its morphogenesis. TCs are also proposed to be involved in the angiogenesis of the esophageal blood capillaries.

Group therapy in a cohort study of Egyptian patients with rheumatoid arthritis.

INTRODUCTION: Rheumatoid arthritis (RA) affects many individuals' issues beyond those which are medically treated. OBJECTIVE: To study the impact of group therapy sessions on disease activity and functional abilities in RA patients. METHODS: One hundred and two patients with RA were divided into two groups; group A included 52 RA patients receiving their regular medical care in addition to group therapy sessions (cases); and group B included 50 RA patients receiving their regular medical care only (controls). Demographic, clinical and serological data were prospectively evaluated. All patients were assessed by using the Disease Activity Score of 28 joints (DAS28) and modified Health Assessment Questionnaire - Disability Index (mHAQ-DI), Hospital Anxiety and Depression scale (HAD) before, during and after group therapy sessions. RESULTS: Group A showed a statistically significant improvement in DAS28 at the 3rd and 6th months (P < 0.01 and P < 0.04) respectively, significant improvement in mHAQ score at the 3rd and 6th months (P < 0.02 and P < 0.00) respectively, and significant improvement in HAD scale for depression and anxiety (P <0.001). In group A there was no significant correlation between DAS28 and both anxiety or depression (P = 0.6, r = 0.5 and P = 0.06, r = 0.06) respectively, but on correlating mHAQ to both anxiety and depression, there was a statistically significant positive correlation at 6 months (P = 0.01, r = 0.3 and P = 0.03, r = 0.3) respectively. CONCLUSION: Group therapy sessions improve disease outcome, functional disability and psychological well-being in RA patients.

Increased arterial stiffness in rheumatoid arthritis and Its relation to disease activity: A cross sectional study.

BACKGROUND: Rheumatoid arthritis (RA) is associated with elevated plasma level of inflammatory markers. Chronic inflammation is known to predispose to endothelial dysfunction and increased arterial stiffness, which is an important marker of subclinical atherosclerosis and increased cardiovascular risk. OBJECTIVE: The aim is to test for the relationship between disease activity and arterial stiffness in RA patients. METHODS: The study included 90 RA patients, at different grades of disease activity and 45 healthy subjects, as a control group. Patients were subjected to full history taking and clinical examination, laboratory investigations including serum lipid profile and high sensitivity CRP (hs-CRP) measurements and plain x-rays of hands and feet. Modified Larsen method was used as radiographic scoring method. Disease activity score (DAS 28) was used for assessment of disease activity. Transthoracic echocardiography was performed to detect aortic stiffness parameters. Duplex ultrasound imaging of both common carotid arteries was performed to measure carotid stiffness parameters. RESULTS: The mean age of RA patients was 39.86 ±â€¯9.39 years and most of them (83.3%) were females. RA patients had higher carotid stiffness index compared to control group patients (8.57 ±â€¯4.83 vs 4.08 ±â€¯1.13, p < .001). Very poor correlation was found between DAS-28 and aortic (r = 0.1, p = .28) as well as carotid (r = 0.05, p = .7) stiffness indices. No statistically significant correlation was found between hs-CRP and aortic stiffness index (r = 0.64, p = .55). Disease duration was significantly correlated to intima-media thickness (p < .01) as well as with other carotid stiffness parameters. Age also show a statistically significant positive correlation with carotid stiffness parameters. CONCLUSION: RA is associated with increased arterial stiffness, a well-recognized marker of cardiovascular risk. This is attributed to the inflammatory nature of the disease. It seems that the most important factors determining stiffness are patients' age and duration of illness.

Assessment of Corneal and Tear Film Parameters in Rheumatoid Arthritis Patients Using Anterior Segment Spectral Domain Optical Coherence Tomography.

PURPOSE: To study the corneal changes in rheumatoid arthritis (RA) patients in vivo, using spectral domain anterior segment optical coherence tomography (AS-OCT). METHODS: A case-control study was done on 43 RA patients and 40 controls. The disease activity score (DAS28-ESR) was calculated and all participants had lower tear meniscus, corneal thickness, and epithelial thickness evaluation using AS-OCT. RESULTS: The lower tear meniscus height (LTMH) and the lower tear meniscus area (LTMA) were significantly lower in the RA patients than in controls (p < 0.001). RA patients also had a significantly thinner central corneal thickness (p = 0.02) and their epithelium was found to be thinner in the superotemporal peripheral sector. CONCLUSIONS: The LTMH and LTMA are significantly reduced in RA patients, despite the absence of clinical diagnosis of dry eye. RA patients have thinner corneal thickness and epithelial thickness than controls, which did not correlate with either disease duration or activity.

Magnetic resonance sialography of the parotid glands in chronic hepatitis C virus patients with and without vasculitis.

AIM: Hepatitis C virus (HCV) is sialotropic. The pathogenesis of sicca manifestations in patients with chronic HCV infection is not fully understood. We aimed to detect changes in magnetic resonance sialography (MRS) of HCV patients with and without vasculitis. METHOD: We studied 32 HCV patients (19 female, mean age 48.8 ± 10.3 years) and 20 age- and gender-matched healthy controls. Half of the patients had vasculitis. Demographic, clinical and serological data were prospectively evaluated. In patients with vasculitis, the disease activity was assessed by the Birmingham Vasculitis Activity Score (BVAS). MRS was performed on all patients and controls. RESULTS: Abnormal MRS was found in 25% of patients, (6/16 and 2/16 in patients with and without vasculitis, respectively). Among patients with vasculitis, those with abnormal MRS had longer disease duration, higher leukocytic and lymphocytic counts and more frequent cryoglobulinemia (P < 0.01, P < 0.001, P < 0.001 and P < 0.008, respectively), while BVAS scores were not significantly different. CONCLUSION: Among HCV patients with vasculitis, longer disease duration and cryoglobulinemia were associated with abnormal findings on MRS. To confirm our results, we propose larger-scale, multicentre studies with longer evaluation periods.

Detection of asymptomatic cranial neuropathies in patients with systemic lupus erythematosus and their relation to antiribosomal P antibody levels and disease activity.

The objectives of this study are to assess the risk of asymptomatic cranial neuropathy among patients with systemic lupus erythematosus (SLE) and find any association with disease activity and antiribosomal P antibodies. This study is a case-control study including 60 female patients and 30 healthy female controls. Disease activity was measured with the SLE disease activity index (SLEDAI). All patients were evaluated using evoked potentials, blink reflex, and levels of antiribosomal P antibodies. Patients with abnormal electrophysiological parameters had significantly higher levels of antiribosomal P antibodies (P = 0.034) and secondary antiphospholipid syndrome (P = 0.044). Antiribosomal P antibodies (odds ratio 5.4, 95 % confidence interval 1.002-1.03, P = 0.002) and presence of anti-DNA antibodies (odds ratio 1.01, 95 % confidence interval 1.2-24.8, P = 0.032) were independent risk factors for the presence of the abnormal electrophysiological parameters. Disease duration was positively correlated with wave 1 of the auditory brain reflex (P < 0.001) and a latency of the evoked blink reflex (component R1, P = 0.013). SLEDAI scores were positively correlated with latencies of the visually evoked potential (P100, P = 0.02), wave 1 of the auditory brain reflex (P < 0.001), and a latency of the evoked blink reflex (R2c, P = 0.005). Steroid dosage was negatively correlated with P100 latencies (P = 0.042) and components of the evoked blink reflex (R1, P = 0.042; R2i, P = 0.041; R2c, P < 0.001). Because abnormalities in the visually evoked potential and blink reflex were associated with antiribosomal P antibodies, they can be useful for detecting asymptomatic cranial neuropathy. Further studies on large number of patients should be done to determine any association.

The infantile visceral leishmaniasis: could it attack Egyptian north coastal region again?

Visceral leishmaniasis is caused by three species of the L. donovani complex: L. donovani, L. infantum, and L. chagasi. Infections with these organisms are often asymptomatic or very mild, but in a minority of individuals there is progression to severe symptomatic disease. This is associated with spread of the infection throughout the reticuloendothelial system. L. infantum typically affect children below the age of 5 years. However, IVL can also occur in immunosuppressed adults, such as transplant recipients and patients receiving immunosuppressive chemotherapy or patients suffering from chronic intestinal schistosomiasis. IVL was encountered in Al-Agamy, Alexandria on 1983 with Phlebotomus langeroni. This vector is still abundant with low density away from Al-Agamy. Urbanization of the north coastal area in the vicinity of Alexandria changes the ecological status but how does it affect the behavior of sandflies; mainly the IVL vector Phlebotomus langeroni? Many employees and their families return home from Libya with fever with or without other accompanying symptoms. Fever can be a manifestation of a minor, self-limited process or can herald a progressive, life-threatening illness. The detection of Phlebotomus langeroni in El-Hamam City, Sedi Barany City, and Matrooh City and the abundance P. papatasii in these three cities in addition to Al Agamy must be taken into consideration of the Public Health Authority.

Is plague a problem in the Egyptians returning back from Libya?

Many employees return home with fever with or without other accompanying symptoms. Fever can be a manifestation of a minor, self-limited process or can herald a progressive, life-threatening illness. The assessment of this group is often hampered by the clinician's lack of familiarity with the types of infections that the patient may have encountered while traveling. The evaluation of such patients should focus on: What infections are possible given where the patient has lived or traveled and the time when exposures may have occurred? Which of these infections is more probable given the patient's clinical findings and potential exposures? Which of these infections is treatable or transmissible or both? On the other hand, the outbreak of plague at the Libyan-Egyptian borders and the high density rodents and their ecto-parasitic fleas in many Egyptian governorates should be embarked a control program to rodents and fleas and to raise the awareness of the concerned authorizes.