The effects of ultraviolet C radiation on the ultrastructure of the liver cells of mole rats

The aim of this study was to elucidate the ultrastructural changes in the liver cells of mole rats (Spalax leucodon) exposed to ultraviolet radiation (UVR). Thirteen mole rats used in this study were caught from nature. They were divided into four groups. The first group was separated as a control and was not given any radiation. The rest were exposed to ultraviolet C (UVC) radiation for 7, 14, and 21 days. The electron microscopic examinations revealed that significant ultrastructural changes occurred in the liver tissue. These changes were the reduction in cytoplasmic organelles, dilatation in rough endoplasmic reticulum, impairment of nucleus membrane, and broadened and vacuolated mitochondria in the cytoplasm. Also, UVC radiation caused significant changes in liver enzymes of aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase, and gama-glutamiltransferase values. After long-term exposure to radiation, some excessive ultrastructural changes occurred. These results indicated that longer exposure to UVR would cause more ultrastructural effects on the liver cells and liver enzymes.     

Molecular epidemiology of HIV type 1 in Singapore and identification of novel CRF01_AE/B recombinant forms

To investigate HIV-1 molecular epidemiology in Singapore, we sequenced portions of three regions of the HIV-1 genome (protease HXB2: 2163 to 2620, gp120 HXB2: 6904 to 7628, and gp41 HXB2: 7817 to 8264) from 212 plasma samples collected between February 2008 and August 2009. From these samples, 109 (51.4%) generated interpretable data in all regions. Sixty-one (56.0%) were identified as CRF01_AE, 26 (23.9%) as subtype B and 14 (12.8%) as possible novel recombinant forms. The main novel recombinant pattern, detected in 13 sequences, had subtype B in protease and gp41 and CRF01_AE in gp120. There was intermixing of subtypes within transmission risk groups. However, 85% of subjects infected with the novel recombinant forms self-identified as men who have sex with men or bisexuals compared with only 41% of individuals infected with CRF01_AE and 62% infected with subtype B (p = 0.001).     

In vitro biomechanical evaluation of modified plating techniques for bilateral sagittal split ramus osteotomy in mandibular advancement

ABSTRACT: The aim of this study was to compare the biomechanical properties of modified plate techniques using a newly designed three-dimensional test model after sagittal split ramus osteotomy. Fifteen synthetic polyurethane mandibular replicas were used and divided into 3 groups. Self-tapping 6-mm titanium screws with an outer diameter of 2.0 mm and private designed plates produced by 316-L stainless steel were used in the study. After the osteotomy, the distal part was advanced by 5 mm. The jaw models were placed to the three-dimensional test model designed by the authors, and the Instron Lloyd LRX device was used to apply a double-sided tensile force from the mandible angulus region of each group. Resistance forces that caused a displacement of 1.5 and 3 mm were recorded with the Instron program. The mean (SD) of the 3 groups were calculated using analysis of variance and the Tukey test. The results were compared statistically, with values of P < 0.05 determined as statistically significant. On the basis of the results of the Tukey comparison within the groups, there was a statistically significant difference between groups 1 and 2 and between groups 1 and 3 at both 1.5- and 3-mm displacement (P < 0.05). No significant difference was observed between groups 2 and 3 (P > 0.05). This test model was able to identify the most appropriate plate type of 3 different modified plate techniques after sagittal split ramus osteotomy.     

Prenatal diagnosis of ranula at 21 weeks of gestation.

A fetal sublingual cystic lesion was diagnosed by routine prenatal ultrasonography at 21 weeks of gestation and followed up until term in a tertiary care center. Fetal growth was normal as was the amniotic fluid volume. Ex utero intrapartum treatment was performed and the cyst was aspirated to allow breathing and swallowing during planned Cesarean section. The cyst was totally excised when the newborn was 27 days of age and histological examination revealed a mucous cyst of the mouth floor.     

The effect of benzalkonium chloride on rabbit nasal mucosa in vivo: an electron microscopy study

In this study we investigated the histopathological changes of nasal mucosa after the use of topical benzalkonium-chloride solution. In the study, 28 male New Zealand white rabbits were used. The animals were divided into two groups. In the first group, 50 micro l of 0.001% benzalkonium-chloride solution was sprayed into the right nostril and 50 micro l of 0.9% saline into the left twice daily for 14 days. In the second group, the same solutions were applied twice daily for 28 days. All of the biopsies from each nasal cavity were processed for electron microscopy. In the nostrils treated with 0.001% benzalkonium chloride, there were areas with obvious squamous cell metaplasia. Some cells showed broken cristae of the mitochondria. Degenerative changes in the supportive and olfactory cells, deformation of nuclei and the increase of heterochromatin were observed. The present investigation has shown that the application of topical benzalkonium chloride does induce degenerative morphologic changes in the nasal mucosa in rabbits in vivo.     

Complications of chronic suppurative otitis media: a retrospective review

The purpose of this study was to review our patients with complications of chronic suppurative otitis media (CSOM) and compare with literature. This retrospective study was performed over 10 years in our tertiary referral university hospital. During this period 4,630 patients with CSOM were admitted to the department and 906 patients underwent a surgery. From the records of the 4,630 patients, 121 patients (2.6%) with complications were identified. Of the 906 CSOM patients that underwent a surgery, 511 had cholesteatoma, and 395 had granulation and/or polyp tissue. Ninety-four of 511 (18.4%) patients with cholesteatoma and 27 of 395 (6.8%) patients with granulation and/or polyp tissue had a complication. Of the 121 complicated CSOM patients, 57 extracranial (47.1%) and 37 intracranial (30.6%). Multiple combined complications were occurred in 27 (22.3%) patients. The mastoid abscess was the commonest extracranial complication (28.3%); it was followed by labyrinthitis (9%), facial nerve paralysis (8.4%), and Bezold’s abscess (1.3%). The most common intracranial complication was lateral sinus thrombophlebitis (19.5%), followed by perisigmoid sinus abscess (13.5%), meningitis (9%), brain abscess (6.5%), and extradural abscess (4.5%). Most frequent intraoperative finding of complicated CSOM patients was cholesteatoma, with the exception of patients with facial nerve paralysis. There was no mortality in any of our patients. The additional morbidities were recorded in 25 patients (20.6%). In this study, we emphasize the importance of an accurate and early diagnosis, followed by adequate surgical therapy and a multidisciplinary approach.     

Evaluation of choroidal and retinal thickness measurements using optical coherence tomography in non-diabetic haemodialysis patients

The aim of this study is to evaluate the effects of haemodialysis with a high ultrafiltration rate on the choroidal and retinal thickness of non-diabetic end-stage chronic renal failure (CRF) patients using optical coherence tomography (OCT). Twenty-one eyes of 21 male CRF patients aged between 46 and 80 years were included in this prospective study. Retinal and choroidal thicknesses of the patients were measured using high-resolution OCT line scans with the activated enhanced depth imaging mode before and shortly after haemodialysis. Retinal and choroidal thickness measurements were taken at the fovea and at two points that were 1,500 μm nasal and temporal to the fovea. The relationships between the haemodynamic changes, intraocular pressure (IOP) and central corneal thickness (CCT) were also evaluated. The mean choroidal thicknesses before haemodialysis at the subfoveal, temporal and nasal locations were 232.81 ± 71.92, 212.43 ± 70.50 and 182.14 ± 68.88 μm, respectively. The mean choroidal thicknesses after haemodialysis at the subfoveal, temporal and nasal locations were 210.90 ± 65.53, 195.38 ± 66.48 and 165.19 ± 66.73 μm, respectively. There were significant differences between the choroidal thicknesses before and after haemodialysis (p < 0.001 for all). The mean retinal thicknesses before haemodialysis at the foveal, temporal and nasal locations were 215.86 ± 41.06, 308.86 ± 37.73 and 338.00 ± 33.32 μm, respectively. The mean retinal thicknesses after haemodialysis at the foveal, temporal and nasal locations were 216.90 ± 39.70, 313.86 ± 32.89 and 335.29 ± 36.85 μm, respectively. There was no significant difference between the retinal thicknesses before and after haemodialysis (p > 0.05 for all). The mean CCT decreased insignificantly from 550.48 ± 17.46 to 548.10 ± 21.12 μm (p = 0.411). The mean IOP decreased significantly from 14.09 ± 2.58 to 12.54 ± 2.23 mmHg (p = 0.003), which did not correlate with the CCT [r = (?)0.134, p = 0.562]. Haemodialysis with a high ultrafiltration volume did not alter the retinal thickness but caused a significant choroidal thinning and an IOP decrease in non-diabetic end-stage CRF patients.     

The role of adenosine receptors and endogenous adenosine in citalopram-induced cardiovascular toxicity

Aim:

We investigated the role of adenosine in citalopram-induced cardiotoxicity.

Materials and Methods:

Protocol 1: Rats were randomized into four groups. Sodium cromoglycate was administered to rats. Citalopram was infused after the 5% dextrose, 8-Cyclopentyl-1,3-dipropylxanthine (DPCPX; A₁ receptor antagonist), 8-(-3-chlorostyryl)-caffeine (CSC; A_2a receptor antagonist), or dimethyl sulfoxide (DMSO) administrations. Protocol 2: First group received 5% dextrose intraperitoneally 1 hour prior to citalopram. Other rats were pretreated with erythro-9-(2-hydroxy-3-nonyl) adenine (EHNA; inhibitor of adenosine deaminase) and S-(4-Nitrobenzyl)-6-thioinosine (NBTI; inhibitor of facilitated adenosine transport). After pretreatment, group 2 received 5% dextrose and group 3 received citalopram. Adenosine concentrations, mean arterial pressure (MAP), heart rate (HR), QRS duration and QT interval were evaluated.

Results:

In the dextrose group, citalopram infusion caused a significant decrease in MAP and HR and caused a significant prolongation in QRS and QT. DPCPX infusion significantly prevented the prolongation of the QT interval when compared to control. In the second protocol, citalopram infusion did not cause a significant change in plasma adenosine concentrations, but a significant increase observed in EHNA/NBTI groups. In EHNA/NBTI groups, citalopram-induced MAP and HR reductions, QRS and QT prolongations were more significant than the dextrose group.

Conclusions:

Citalopram may lead to QT prolongation by stimulating adenosine A₁ receptors without affecting the release of adenosine.KEY WORDS: Adenosine receptor, citalopram toxicity, endogenous adenosine, QT prolongation, rat