Effects of losartan treatment on the physicochemical properties of diabetic rat bone.

Inhibitors of the renin-angiotensin system used to treat several diseases have also been shown to be effective on bone tissue, suggesting that angiotensin-converting enzyme inhibitors and angiotensin receptor blockers may reduce fracture risk. The present study investigated the effects of losartan on the physicochemical and biomechanical properties of diabetic rat bone. Losartan (5 mg/kg/day) was administered via oral gavage for 12 weeks. Bone mineral density (BMD) was measured using dual-energy X-ray absorptiometry. Whole femurs were tested under tension to evaluate the biomechanical properties of bone. The physicochemical properties of bone were analyzed by Fourier transform infrared spectroscopy. Although losartan did not recover decreases in the BMD of diabetic bone, it recovered the physicochemical (mineral and collagen matrix) properties of diabetic rat bone. Furthermore, losartan also recovered ultimate tensile strength of diabetic rat femurs. Losartan, an angiotensin II type 1 receptor blocker, has a therapeutic effect on the physicochemical properties of diabetic bone resulting in improvement of bone strength at the material level. Therefore, specific inhibition of this pathway at the receptor level shows potential as a therapeutic target for diabetic patients suffering from bone diseases such as osteopenia.

The Effect of Traction Force and Hip Abduction Angle on Pudendal Nerve Compression in Hip Arthroscopy: A Cadaveric Model.

PURPOSE: To investigate the site of pudendal nerve compression and the relation between traction force and abduction angle regarding pressure levels at setup for hip arthroscopy. METHODS: A total of 17 hips from 9 fresh-frozen cadavers (6 male and 3 female cadavers) were used. The pudendal nerves were dissected, and 3 FlexiForce force sensors (Tekscan, Boston, MA) were implanted on the pudendal nerve where the inferior rectal nerve, perineal nerve, and dorsal nerve of the clitoris/penis emerge. A custom-made traction table in a supine position was used with a padded perineal post of 9 cm. Recordings were made at 0, 10, 20, 30, and 40 kg of traction at varying hip abduction angles of 0°, 15°, 30°, and 45°. RESULTS: The tuber ischiadicum (perineal nerve) and genital region (dorsal nerve of penis/clitoris) had statistically higher pressure values when compared with the pudendal canal (inferior rectal nerve) (P < .05). There was a significant increase in forces acting on the pudendal nerve with increasing application of 0 to 40 kg of traction in steps of 10 kg, with the exception of the pudendal canal sensor and reading of the perineal nerve sensor at 45° of hip abduction (P < .004 with Bonferroni correction for significant values). On the contrary, hip abduction angle had no statistically significant effect on pudendal nerve compression. (All specific P values with Bonferroni correction were greater than .003.) CONCLUSIONS: To avoid nerve palsy completely, the etiopathogenesis of compressive neuropathy should be identified. The location for compression and relation between different traction positions and forces are clarified in this study. This information can be used for further research and prevention. CLINICAL RELEVANCE: This study adds objective data on the etiopathogenesis of pudendal nerve compression, which potentially contributes to prevention of pudendal nerve palsy as a common complication of hip arthroscopy.

[Morphometric anatomic study and clinical significance of lunate fossa]. / Lunat fossanin morfometrik anatomik çalismasi ve klinik önemi.

OBJECTIVES: This study aims to investigate the depth, transverse and sagittal diameters of lunate fossa which is a significant structure of the wrist in terms of reducing the risk for volar plate screws, which are administered in distal radius fractures, from penetrating into the joint. MATERIALS AND METHODS: Depth, transverse and sagittal diameters of lunate fossa in 50 right and 50 left adult dried radius bones without distal tip damage were measured by using MicroscribeG2X from the MicroScribe G series. RESULTS: Mean lunate fossa depth: left 2.419886±0.51 mm/right 2.543052±0.78 mm, mean lunate fossa sagittal diameter: left 19.656±1.57 mm/right 18.796±1.53 mm, mean lunate fossa transverse diameter: left 11.382±0.65 mm/right 11.106±0.91 mm. There was no statistically significant difference between right and left depth values of lunate fossa (p=0.320), whereas there was statistically significant difference between right and left transverse and sagittal diameters (p=0.006, p=0.048). CONCLUSION: Measurements involving depth of lunate fossa may guide the development of new anatomic plates and decrease complications like the penetration of screw into joint whilst volar plate administrations.

Sodium tungstate alleviates biomechanical properties of diabetic rat femur via modulation of oxidative stress.

Diabetes mellitus leads to bone disorders such as osteopenia and osteoporosis that can increase fracture risk. On the other hand, sodium tungstate is an inorganic compound which exerts anti-diabetic activity in experimental studies due to its suggested insulin-mimetic or antioxidant activity. Therefore this study was designed to investigate the effect of tungstate on bone quality in diabetic rat femurs. The rats were divided into four groups: Control (C), tungstate-treated control (C+Tung), diabetes (STZ-D) and tungstate-treated diabetes (STZ-D+Tung). Diabetes mellitus was induced by single injection of streptozotocin (50 mg/kg). The treated rats received 150 mg/kg/day of sodium tungstate for 12 weeks. Sodium tungstate achieved a little (17%) but significant reduction on blood glucose levels, while it didn't recover the reduced body weights of diabetic rats. In addition, impaired bone mechanical quality was reversed, despite the unchanged mineral density. Sodium tungstate administration significantly lowered the 2-thiobarbituric acid reactive substances and restored the activity of tissue antioxidant enzymes such as glutathione peroxidase, catalase and superoxide dismutase in diabetic rats. On the other hand, glutathione levels didn't change in either case. These findings indicate that tungstate can improve the reduced mechanical quality of diabetic rat femurs due probably to reduction of reactive oxygen species and modulation of antioxidant enzymes as well as reduction in blood glucose levels.

Effect of angiotensin II type 1 receptor blocker on osteoporotic rat femurs.

BACKGROUND: Osteoblasts and osteoclasts are known to express Ang II type I (AT1) receptor in cell cultures, suggesting the existence of local renin-angiotensin system (RAS) in bone. This study was designed to investigate the effects of losartan as AT1 receptor blocker on ovariectomized rats' femur. METHODS: Losartan (5 mg/kg/day) was administered via oral gavage for 8 weeks. Bone mineral density (BMD) was measured using dual energy X-ray absorptiometry, while tensile and three-point bending tests were performed for evaluation of biomechanical properties of bone. The trabecular porosity was analyzed by scanning electron microscopy. RESULTS: There was a significant decrease in BMD values of ovariectomized rats' femurs which were reversed by losartan treatment. According to tensile test results, ultimate tensile strength and strain values of losartan treated ovariectomized rats' femurs increased and decreased, respectively, when compared to that of ovariectomized animals. Losartan treatment also caused a significant recovery in flexural strength and modulus parameters regarding respective control values, which mean losartan treated ovariectomized rats' femur had more force tolerance until break than ovariectomized rats' femur. Quantitative microscopic analysis showed larger trabecular porosity in ovariectomized rats than control rat femurs and it was significantly decreased after losartan treatment. CONCLUSION: Blockage of AT1 receptor increased strength, mass and trabecular connections of ovariectomized rat femurs. Therefore, it is tempting to speculate that drugs, including AT1 receptor blockers, may be used for the treatment of osteoporosis or reduction of its detrimental effects in the future.

Definition of a safe-zone in open carpal tunnel surgery: a cadaver study.

Carpal tunnel decompression is one of the most common surgical procedures in hand surgery. Cutaneous innervation of the palm by median and ulnar nerves was evaluated to find a suitable incision preserving cutaneous nerves. A morphometric study was designed to define the safe-zone for mini-open carpal tunnel release. Sixteen fresh-frozen (8 right, 8 left) and 14 formalin-fixed (8 right, 6 left) cadaveric hands were dissected. Anatomy of the palmar cutaneous branch of the median and the ulnar nerve, motor branch of the median nerve, superficial palmar arch were evaluated relative to the surgical incision. We also identified the motor branch of the median nerve. Detailed measurements of the whole palmar region are reported in this study. The motor branch of the median nerve was extraligamentous as 60%, subligamentous as 34%, transligamentous as 6%. The palmar cutaneous branches of the median and the ulnar nerves in the palmar region were classified as Type A (34%), Type B (13%), Type C (13%), Type D (none), Type E (40%) according to forms of palmar cutaneous innervation originating from the ulnar and median nerves. Injury to the palmar cutaneous branch of the median nerve (PCBMN) is the most common complication of the carpal tunnel surgery. Various techniques were described to decrease post-operative morbidity. Based on these anatomic findings mini incision between the superficial palmar arch and the most distal part of the PCBMN in the palmar region is the safe-zone for carpal tunnel surgery.

[E-learning and problem based learning integration in cardiology education]. / Kardiyoloji egitiminde e-ögrenme ve probleme dayali ögrenme entegrasyonu.

OBJECTIVE: The aim of this study was to determine students' satisfaction with an e-learning environment which is developed to support classical problem-based learning (PBL) in medical education and its effect on academic achievement. METHODS: In this cross-sectional study, students were provided with a web-based learning environment including learning materials related to objectives of the subject of PBL module, which could be used during independent study period. The study group comprised of all of the second year students (164 students) of Akdeniz University, Medical Faculty, during 2007-2008 education period. In order to gather data about students' satisfaction with learning environment, a questionnaire was administered to the students. Comparison of students' academic achievement was based on their performance score in PBL exam. Statistical analyses were performed using unpaired t test and Mann Whitney U test. RESULTS: Findings indicated that 72.6% of the students used e-learning practice. There is no statistically significant difference between mean PBL performance scores of users and non-users of e-learning practice (103.58 vs. 100.88) (t=-0.998, p=0.320). It is found that frequent users of e-learning application had statistically significant higher scores than non-frequent users (106.28 vs. 100.59) (t=-2.373, p=0.01). In addition, 72.6% of the students declared they were satisfied with the application. CONCLUSION: Our study demonstrated that the most of the students use e-learning application and are satisfied with it. In addition, it is observed that e-learning application positively affects the academic achievement of the students. This study gains special importance by providing contribution to limited literature in the area of instructional technology in PBL and Cardiology teaching.

Effects of formaldehyde inhalation on the junctional proteins of nasal respiratory mucosa of rats.

Exposure to formaldehyde, which is an organic compound, disturbs the integrity of nasal mucosa. In this study, we aimed to clarify the protein changes in the junctional complex of nasal mucosa of Wistar rats exposed to formaldehyde inhalation. The study was performed in 20 female Wistar rats. Rats were divided into two groups randomly. Control rats were allowed free access to standard rat chaw and tap water (n:10). Experimental group was exposed to formaldehyde vapor at 15ppm, 6h/day, 5 days/week for 12 weeks (n:10). Histological evaluation of the experimental model was determined by hematoxylin-eosin (HE) and periodic acid Schiff (PAS) stainings of paraffin-embedded nasal mucosa tissues and by electron microscopy. The effects of formaldehyde inhalation on the distribution of occludin, E-cadherin, and gamma-catenin were assessed by immunohistochemistry. The nasal mucosa of the experimental group was correlated with hypertrophy in goblet cell, degeneration in basal lamina, stratification of epithelium, and proliferation. Thickness of basal lamina and also local degenerative regions, vacuole increase in cytoplasmic areas, irregular forms of kinocilium and loss of sharpness in the kinocilium membrane were the findings at the ultrastructural level. The expressions of E-cadherin, occludin, gamma-catenin proteins in intercellular junctional complexes of rat nasal mucosa were also decreased in experimental group compared to control group. The findings of the present study indicated that formaldehyde vapor inhalation in the concentrations and duration of exposure used in the present experiment significantly decreased the density of structural proteins of the junctional complex in the nasoepithelium. It was suggested that, the formaldehyde inhalation could cause complete impairment of intercellular junctional complexes and disturb the tissue integrity in nasal mucosa at higher concentrations.

Morphological and ultrastructural analysis of the watershed zones after stripping of the vasa nervorum.

Peripheral nerve trunks are well-vascularized structures where a well-developed collateral system may compensate for local vascular damage. Vasculitis in nerve has a predilection for epineurial vessels and causes to the peripheral neuropathy, which is a major clinical feature of primary and secondary systemic vasculitides. In the present study, the goal was to simulate the vasculitic neuropathy in rat sciatic nerve and to investigate the watershed zones after stripping of the epineural vessels of the sciatic nerve. Sciatic function index values, light and electron microscopic evaluations of the experimental sciatic nerve suggested that the sciatic nerve was normal except for some watershed zones located in the peripheral part of the nerve. Although there is abundant collateral circulation in the peripheral nerve, distribution of the vessels of the watershed zones as observed in the present study should be elucidated by further studies.

The evolution of the terminology of the basal ganglia, or are they nuclei?

Basal ganglia have been generally used to refer to some subcortical nuclei. However, it is a misnomer since ganglion is a group of nerve cells especially located outside of the brain or spinal cord. We evaluated the terminology of the basal ganglia from historical and terminological points of view.

Anterior intermeniscal ligament: an ultrastructural study.

The aim of the present study was to investigate the detailed histological characteristics of membranous and cord-like anterior intermeniscal ligaments (AIMLs) by transmission electron microscopy (TEM) and light microscopy. Ten biopsies of AIMLs were sampled from 10 knees during total knee arthroplasty procedures. Three of them were membranous and 7 of them were cord-like. They were processed for light and TEM evaluations. Histologically, the findings in the membranous and cord-like ligaments were similar. They consisted of parallel bundles of collagen fibrils and their posterior surfaces were covered by a layer of loose well-vascularized synovial tissue. The subsynovial region consisted of loose connective tissue and was rich in blood vessels and nerve endings. Fibroblasts embedded between parallel-oriented collagen fibrils were the major cell type that we observed. Free nerve endings were squeezed between bundles of collagen fibers. Electron microscopic observations revealed the presence of Ruffini corpuscles. The presence of neural mechanoreceptors in the membranous and cord-like intermeniscal ligaments may contribute to structural and proprioceptional function of the knee. Protection of those ligaments may be valuable in planning and performing meniscal surgeries.

Angiolipoma located inside the obturator canal and supplied by the umbilical artery.

During dissection of the retropubic region of a 55-year-old female cadaver, we encountered an angiolipoma located inside the obturator canal which was connected to the wall of the urinary bladder by a fibrous cord. The angiolipoma was supplied by a branch originating from the umbilical artery. Microscopically the benign soft tissue tumor was characterized by lobules of mature adipocytes and densely distributed networks of small and larger blood vessels, thus resembling typical histological features of an angiolipoma. Both the uncommon location of the angiolipoma and the abnormal branch of the umbilical artery entering the obturator canal should be taken into account during surgical procedures in this region, such as for orthopedic pelvic procedures, hernia repair or bladder/urethra-related interventions (e.g. transobturator tape, tension-free vaginal tape, colposuspension).

Is there any effect of suprascapular notch type in iatrogenic suprascapular nerve lesions? An anatomical study.

This anatomical study, which is aimed at assessing the effect of suprascapular notch type in iatrogenic suprascapular nerve lesions in surgical interventions, was conducted in two stages. A hundred dry scapulas and 20 scapulas of 11 cadavera were classified according to Rengachary. The point of measurement was determined medially as the deepest point of suprascapular notch and laterally as supraglenoid tubercle in dry scapulas and anchor of biceps in cadavera. It was found that in the measurements made in dry scapulas, notch Type-IV scapulas, despite not being statistically significant, had the lowest average (2.35 cm), with minimum and maximum values of 2.1 cm and 2.78 cm respectively, when compared to other scapula types. It was found in the cadavera study that the measurements of one Type-IV scapula and one Type-V scapula were lower than the other types. Determination of the notch type in the rotator-cuff tears--especially in massive and retracted tears where supraspinatus has to be released from the fossa--may be helpful in avoiding iatrogenic nerve lesion.