A Cadaveric Based Morphometric Analysis of the Sciatic Nerve with Clinical Implications

Background: The sciatic nerve is one of the very vital nerves of the body, which has importance not only in the field of Anatomy but also in various clinical fields such as Orthopaedics, Anaesthesia, Plastic & Reconstructive Surgery, and Neurosurgery. This study was the first attempt to analyze the different dimensions of the anatomically normal sciatic nerves at different levels, involving Malaysian cadavers.Material & Methods:The study was conducted on 78 adult, both cadaveric and disarticulated lower limb specimens belonging to both genders. The morphometric analysis was done in 64 specimens having anatomically normal sciatic nerves. The dimensions were measured by a digital Vernier caliper, a measuring tape, and thread.Results:The average width, thickness and circumference of the nerve at the lower border of piriformis muscle (PM) were 15.86 mm ± 1.47 (right) & 16.56 mm ± 1.08 (left); 4.22 mm ± 0.29 (right) & 4.10 mm ± 0.20 (left) and 27.70 mm ± 2.02 (right) & 27.72 mm ± 2.39 (left), respectively. Similarly, at the level between ischial tuberosity (IT) and greater trochanter (GT), the mean width was 11.59 mm ± 1.43 (right) & 11.50 mm ± 1.53 (left); thickness was 3.48 mm ± 0.18 (right) & 3.35 mm ± 0.17 (left) and circumference was 27.08 mm ± 2.79 (right) & 27.22 mm ± 2.87 (left). At bifurcation, the mean width was 8.66 mm ± 0.65 (right) & 8.90 mm ± 0.81 (left); thickness was 2.41 mm ± 0.12 (right) & 2.31 mm ± 0.15 (left) and circumference was 19.75 mm ± 1.44 (right) & 19.99 mm ± 1.45 (left). The average distance between IT and GT was 50.37 mm ± 4.47 (right) & 47.73 mm ± 4.24 (left); between lateral border of IT and medial border of sciatic nerve was 15.43 mm ± 1.45 (right) & 14.66 mm ± 1.37 (left); and between medial border of GT and lateral border of the nerve was 27.13 mm ± 1.38 (right) & 25.07 mm ± 1.73 (left). The average length of the nerve was 328.20 ± 26.26 (right) & 332.31 ± 21.89 (left); and that of the thigh was 412.19 ± 24.50 (right) & 407.24 ± 25.82 (left).Conclusion: This knowledge will not only aid future researchers but also will assist surgeons, orthopaedicians, anaesthetists, reconstructive surgeons, and neurosurgeons by preventing iatrogenic nerve injuries.

Sex hormones in Malay and Chinese men in Malaysia: are there age and race differences?

OBJECTIVES: Variations in the prevalence of sex-hormone-related diseases have been observed between Asian ethnic groups living in the same country; however, available data concerning their sex hormone levels are limited. The present study aimed to determine the influence of ethnicity and age on the sex hormone levels of Malay and Chinese men in Malaysia. METHODS: A total of 547 males of Malay and Chinese ethnicity residing in the Klang Valley Malaysia underwent a detailed screening, and their blood was collected for sex hormones analyses. RESULTS: Testosterone levels were normally distributed in the men (total, free and non-sex hormone-binding globulin (SHBG) bound fractions), and significant ethnic differences were observed (p<0.05); however, the effect size was small. In general, testosterone levels in males began to decline significantly after age 50. Significant ethnic differences in total, free and non-SHBG bound fraction estradiol levels were observed in the 20-29 and 50-59 age groups (p<0.05). The estradiol levels of Malay men decreased as they aged, but they increased for Chinese men starting at age 40. CONCLUSIONS: Small but significant differences in testosterone levels existed between Malay and Chinese males. Significant age and race differences existed in estradiol levels. These differences might contribute to the ethnic group differences in diseases related to sex hormones, which other studies have found in Malaysia.

Histomorphometric changes in the perirenal adipocytes of adrenalectomized rats treated with dexamethasone

INTRODUCTION: Prolonged steroid treatment administered to any patient can cause visceral obesity, which is associated with metabolic disease and Cushing's syndrome. Glucocorticoids have a profound negative effect on adipose tissue mass, giving rise to obesity, which in turn is regulated by the 11β-hydroxysteroid dehydrogenase type 1 enzyme. Adrenalectomized rats treated with dexamethasone exhibited an increase in visceral fat deposition but not in body weight. OBJECTIVES: The main aim of this study was to determine the effect of dexamethasone on the histomorphometric characteristics of perirenal adipocytes of adrenalectomized, dexamethasone-treated rats (ADR+Dexa) and the association of dexamethasone treatment with the expression and activity of 11 β-hydroxysteroid dehydrogenase type 1 (11 β-hydroxysteroid dehydrogenase type 1). METHODS: A total of 20 male Sprague Dawley rats were divided into 3 groups: a baseline control group (n = 6), a sham-operated group (n = 7) and an adrenalectomized group (n=7). The adrenalectomized group was given intramuscular dexamethasone (ADR+Dexa) 2 weeks post adrenalectomy, and the rats from the sham-operated group were administered intramuscular vehicle (olive oil). RESULTS: Treatment with 120 μg/kg intramuscular dexamethasone for 8 weeks resulted in a significant decrease in the diameter of the perirenal adipocytes (p<0.05) and a significant increase in the number of perirenal adipocytes (p<0.05). There was minimal weight gain but pronounced fat deposition in the dexamethasone-treated rats. These changes in the perirenal adipocytes were associated with high expression and dehydrogenase activity of 11β-hydroxysteroid dehydrogenase type 1. CONCLUSIONS: In conclusion, dexamethasone increased the deposition of perirenal fat by hyperplasia, which causes increases in the expression and dehydrogenase activity of 11 β-hydroxysteroid dehydrogenase type 1 in adrenalectomized rats.