204 research outputs found
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 variations 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
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 consequently 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 computed 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 arteries 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
Long-term protection of hepatitis B vaccination among Egyptian children
Background: Hepatitis B Vaccination is the most effective way to prevent transmission of hepatitis B virus (HBV). Objective: to detect the long-term immunogenicity of the vaccine in Egyptian children after five and ten years of vaccination. Methods: Two hundreds healthy children were recruited. They were divided into two groups according to their age. Group A included 100 child, around 6 years old, vaccinated 5 years ago. Group `B` included 100 child, around 11 years old, vaccinated 10 years ago. Hepatitis B surface antibody (HBsAb) titre was tested, booster dose of the vaccine was given to children whose HBsAb was < 10 mIU/ml, then one and half month later, they were retested for HBsAb to evaluate the response. Results: Both groups had a wide range of HBsAb (2-1000 mlU/ml), and there was a significant difference in the level of the two groups. Our data proves the decline of antibody titre with time. In group A, 19 children needed a booster dose, 14 of them were vaccinated, and 10 were retested after one and half month. The results showed that 9 (90%) responded by increased level of HBsAb, with six (66.6%) showing an adequate response. In group B, 52 children had antibody titre < 10, 48 of them were vaccinated and 34 were retested one and half months later. Two out of the 34 did not respond and 32 (94.2%) responded by an increase in the antibody titre. Of those who responded, 19 had adequate response (HBsAb ≥ 100) and 13 had hypo-response (HBsAb = 10 -100). Eighty percent (80%) of boys versus 51.7% of girls responded adequately. Conclusion: Hepatitis B vaccine is an effective and successful way for preventing HBV infection. No need for booster dose at least for 5 years after vaccination .Keywords: HBV- HB vaccine- long term immunityEgypt J Pediatr Allergy Immunol 2011;9(1):35-4
Assessing and Analysing Value Added by Private Equity/Venture Capital Firms to Portfolio Companies
The idea of private equity (PE) and/or venture capital (VC) is under an on-going debate, especially when it comes to “adding value” to portfolio firms. Researches find PE/VCs have great contributions to the value of their portfolios. However, there is no definite consensus on the way PE/VCs add value to portfolio companies. Literature suggested many factors influencing value, yet, minimal quantified. Based on a sample size of 1,061 buyout transactions in the UK market over the period 1970–2010, this research will use proxies for measuring value adding inputs and output through two multiple regression models. Overall, results were not very conclusive, yet, for some variables, results of the analysis were coherent with the literature and also gave good indications for the direction and magnitude of relations between some of the suggested variables and the value added proxy. Accordingly, this research will try to contribute to the existing literature through an attempt to shape and quantify some of the previous research suggested factors which add value to firms, while presenting the theory behind them
Preoperative Evaluation and Management of Patients with Liver Disease
Patients with liver disease who undergo surgery have an increased risk of morbidity and mortality. Impairment of the liver functions increases the risks of surgery and anesthesia.The risk depends on the severity of liver disease, nature of the surgery and comorbid conditions. Patients with compensated cirrhosis and normal synthetic function have a low risk. Elective surgery should be postponed in patients with abnormal liver tests. All patients should have thorough preoperative evaluation, and their conditions are to be optimized before elective surgery. Thorough history and physical examination usually provide important informatation. Elective surgery can be rescheduled or cancelled once the severity of underlying liver disease is assessed. When surgery is mandatory, meticulous perioperative management is required, including hemodynamic stability, broad-spectrum antibiotics, correction of coagulopathy, improvement of nutritional status, avoidance of nephrotoxins and sedatives that could precipitate hepatic encephalopathy, and intensive care unit admission if needed
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.
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
The Effect of Nano-SiO2 on the Structural, Electrical and Magnetic Properties of SiO2-LiFe5O8 Glass–ceramics Prepared by Sol Gel Auto-combustion Processing
The glass–ceramic with the composition x(LiFe5O8)/(100 – x) SiO2 (x = 20, 30, 40, 50, 100 wt. % ) were prepared by sol gel auto-combustion method. The influence of the SiO2 ratio in the glass-ceramics strucure prepared was investigated by X-ray diffraction (XRD) and scanning electron microscopy (SEM). Crystalline phases (LiFe5O8, SiO2, Fe2O3) were observed by X-ray powder diffraction in the glasses annealed at 800°C
for 2h. The crystallite size was found to increase from 27.29 nm (x = 20%) to 91.48 nm(x = 100 %). The microstructure of the formed powders was SiO2 ratio dependent. Increasing the SiO2 ratio was found to inhibit the grain growth of the formed ferrite. The electrical conductivity of glass-ceramics samples were raised with increasing the concentration of SiO2 ratio as the result of increasing the hopping of electrons between
Fe2+ and Fe3+ ions. The magnetic characteristics of the prepared glass ceramics were performed using a vibrating sample magnetometer in function of the magnetic field. The samples heat -treated at 800°C for 2h present a ferrimagnetic behavior. Alongside, the formed crystalline silicate lithium ferrite had good magnetic properties. High saturation magnetization (51.9 emu/g) was attained the formed ferrite sample of x = 100 % ratio annealed at 800°C for 2h
The Effect of Nano-SiO2 on the Structural, Electrical and Magnetic Properties of SiO2-LiFe5O8 Glass–ceramics Prepared by Sol Gel Auto-combustion Processing
The glass–ceramic with the composition x(LiFe5O8)/(100 – x) SiO2 (x = 20, 30, 40, 50, 100 wt. % ) were prepared by sol gel auto-combustion method. The influence of the SiO2 ratio in the glass-ceramics strucure prepared was investigated by X-ray diffraction (XRD) and scanning electron microscopy (SEM). Crystalline phases (LiFe5O8, SiO2, Fe2O3) were observed by X-ray powder diffraction in the glasses annealed at 800°C
for 2h. The crystallite size was found to increase from 27.29 nm (x = 20%) to 91.48 nm(x = 100 %). The microstructure of the formed powders was SiO2 ratio dependent. Increasing the SiO2 ratio was found to inhibit the grain growth of the formed ferrite. The electrical conductivity of glass-ceramics samples were raised with increasing the concentration of SiO2 ratio as the result of increasing the hopping of electrons between
Fe2+ and Fe3+ ions. The magnetic characteristics of the prepared glass ceramics were performed using a vibrating sample magnetometer in function of the magnetic field. The samples heat -treated at 800°C for 2h present a ferrimagnetic behavior. Alongside, the formed crystalline silicate lithium ferrite had good magnetic properties. High saturation magnetization (51.9 emu/g) was attained the formed ferrite sample of x = 100 % ratio annealed at 800°C for 2h
- …