Gene-targeted CEP164-deficient cells show a ciliation defect with intact DNA repair capacity

Primary cilia are microtubule structures that extend from the distal end of the mature, mother centriole. CEP164 is a component of the distal appendages carried by the mother centriole that is required for primary cilium formation. Recent data have implicated CEP164 as a ciliopathy gene and suggest that CEP164 plays some roles in the DNA damage response (DDR). We used reverse genetics to test the role of CEP164 in the DDR. We found that conditional depletion of CEP164 in chicken DT40 cells using an auxin-inducible degron led to no increase in sensitivity to DNA damage induced by ionising or ultraviolet irradiation. Disruption of CEP164 in human retinal pigmented epithelial cells blocked primary cilium formation but did not affect cellular proliferation or cellular responses to ionising or ultraviolet irradiation. Furthermore, we observed no localisation of CEP164 to the nucleus using immunofluorescence microscopy and analysis of multiple tagged forms of CEP164. Our data suggest that CEP164 is not required in the DDR.

Gastroprotective effects of CoQ10 on ethanol-induced acute gastric lesions

INTRODUCTION

Alcohol consumption is frequently associated with gastric mucosal lesions. The purpose of this study was to determine the effect of Coenzyme-Q10 (CoQ10) supplementation on the ethanol-induced gastric mucosal damage in a rat model.

MATERIAL AND METHOD

Sixty-four female wistar albino rats were randomly divided into 8 groups (n = 8). Studies were performed in ethanol induced gastric ulcer model in Wistar albino rats. Famotidine at a dose of 5 mg/kg or 20 mg/kg and CoQ10 at a single dose of 10 mg/kg or 20 mg/kg and 30 mg/kg for 7 days were administered as pretreatment. All the rats in study groups received 2 ml/kg ethanol 95 % intragastrically, 30 minutes after pretreatment. Four hour after ethanol administration, all rats were sacrificed and their stomachs were removed under ketamin anaesthesia. Gastric protection was evaluated by measuring the ulcer index, MDA concentrations, and histopathological studies.

RESULTS AND DISCUSSION

Rats pretreated either with famotidine or CoQ10 had significantly diminished gastric mucosal damage which was assessed with gross and microscopic analysis (p < 0.00625). MDA levels were significantly lower in famotidine 20 mg/kg and CoQ10 pretreatment for 7 days group (p < 0.00625).

EVI1 inhibits apoptosis induced by antileukemic drugs via upregulation of CDKN1A/p21/WAF in human myeloid cells

Overexpression of ecotropic viral integration site 1 (EVI1) is associated with aggressive disease in acute myeloid leukemia (AML). Despite of its clinical importance, little is known about the mechanism through which EVI1 confers resistance to antileukemic drugs. Here, we show that a human myeloid cell line constitutively overexpressing EVI1 after infection with a retroviral vector (U937_EVI1) was partially resistant to etoposide and daunorubicin as compared to empty vector infected control cells (U937_vec). Similarly, inducible expression of EVI1 in HL-60 cells decreased their sensitivity to daunorubicin. Gene expression microarray analyses of U937_EVI1 and U937_vec cells cultured in the absence or presence of etoposide showed that 77 and 419 genes were regulated by EVI1 and etoposide, respectively. Notably, mRNA levels of 26 of these genes were altered by both stimuli, indicating that EVI1 regulated genes were strongly enriched among etoposide regulated genes and vice versa. One of the genes that were induced by both EVI1 and etoposide was CDKN1A/p21/WAF, which in addition to its function as a cell cycle regulator plays an important role in conferring chemotherapy resistance in various tumor types. Indeed, overexpression of CDKN1A in U937 cells mimicked the phenotype of EVI1 overexpression, similarly conferring partial resistance to antileukemic drugs.

Overexpression of EVI1 interferes with cytokinesis and leads to accumulation of cells with supernumerary centrosomes in G0/1 phase

Ectopic viral integration site 1 (EVI1), a transcription factor frequently overexpressed in myeloid neoplasias, has been implicated in the generation of malignancy-associated centrosomal aberrations and chromosomal instability. Here, we sought to investigate the underlying cause of centrosome amplification in EVI1-overexpressing cells. We found that overexpression of EVI1-HA in U2OS cells induced supernumerary centrosomes, which were consistently associated with enlarged nuclei or binuclear cells. Live cell imaging experiments identified cytokinesis failure as the underlying cause of this phenotype. In accordance with previous reports, EVI1 overexpression induced a partial cell cycle arrest in G0/1 phase, accompanied by elevated cyclin D1 and p21 levels, reduced Cdk2 activity and activation of the p53 pathway. Supernumerary centrosomes predominantly occurred in resting cells, as identified by low levels of the proliferation marker Ki-67, leading to the conclusion that they result from tetraploidization after cytokinesis failure and are confined to G0/1-arrested tetraploid cells. Depletion of p53 using siRNA revealed that further polyploidization of these cells was inhibited by the p53-dependent tetraploidy checkpoint.

The effects of resveratrol on the healing of left colonic anastomosis

INTRODUCTION

Resveratrol (RSV) is a natural polyphenolic compound found in grape skins and the red wine which improves histological reorganization of the regenerating tissue in dermal wound healing. Since anastomotic healing possesses paramount importance to prevent complications in colorectal surgery, the present study is aimed to evaluate the effect of RSV on the healing of experimental left colonic anastomoses.

METHODS

Thirty-two male Wistar albino rats were randomized into two groups and subjected to colonic anastomosis. The study group was treated with RSV and the control group received tap water instead. The rats were sacrificed 3 and 7 days postoperatively. Wound complications, intra-abdominal abscesses, and anastomotic leaks and stenosis were recorded. Four types of assessment were performed: bursting pressure, hydroxyproline (OHP) content, histopathology, and biochemical analysis.

RESULTS

Compared to the control group, the RSV-treated rats displayed a higher bursting pressure (p < .001) and anastomotic OHP content (p < .05)]. RSV treatment leads to significant increase in PON activity at both time points and decrease in malondialdehyde levels on postoperative day 3 (p < .001). Histopathological analysis revealed that RSV administration leads to a better anastomotic healing in terms of mucosal ischemia, neovascularization, reepithelialization, fibroblast, and lymphocyte infiltration.

CONCLUSION

The study results suggest that exogenous RSV administration exerts a positive effect on experimental colonic wound healing in the rat. Although the precise cellular mechanisms by which RSV enhances anastomotic wound healing is not clear, stimulation of neovascularization, generation of collagen synthesis, inhibition of over inflammation, and restriction of oxidative injury seems to be of paramount importance.

Experimental obstructive jaundice results in oxidized low-density-lipoprotein accumulation in surgical wound of rats

INTRODUCTION

Mounting evidence suggests that impaired wound healing is a well-defined consequence in obstructive jaundice and, as redox-regulated processes are relevant to wound healing, it is not unreasonable to suppose that oxidative stress associated with lipid peroxidation in cholestasis might be a systemic phenomenon probably comprising all tissues and organs, including wounds. The aim of the present investigation was to analyse the lipid peroxidation status of surgical wounds, in terms of oxidized low-density-lipoprotein (oxLDL) accumulation in experimental obstructive jaundice.

METHODS

Sixteen Wistar-Albino rats weighing 200-230 gr were randomly divided into two groups. Group I (n = 8) was designed as the prolonged obstructive jaundice group and was subjected to bile duct ligation. Group II (Sham-control, n = 8) rats underwent laparotomy alone and bile duct was just dissected from the surrounding tissue. Histopathological evaluation, immunohistochemical screening and immunoflourescent staining of the surgical wound was conducted to the bile-duct ligated rats and control group on the 21st postoperative day.

RESULTS

Wound healing was found to be impaired in jaundiced rats histopathologically. When compared with the control group, significant positive oxLDL staining and intracellular accumulation of TNF-alpha, IL-2 and IL-6 was detected in the wound sections of the prolonged obstructive jaundice group.

CONCLUSION

Our present data is the first in the literature, indicating significant oxLDL accumulation in surgical wounds of cholestatic rats, which might be one of the results of systemic oxidative stress leading to deficient healing capacity as a consequence of persistent inflammation.

Inadvertent parathyroidectomy and temporary hypocalcemia: an adverse natural outcome or a true complication during thyroidectomy?

OBJECTIVE

The aim of this study was to assess the factors that might predict patients at increased risk for inadvertent parathyroidectomy and postoperative symptomatic hypocalcemia during thyroidectomy.

METHODS

Demographic data as well as the data on preoperative diagnosis, preoperative ultrasonography reports, operation reports, histological findings, and postoperative symptomatic hypocalcemia were collected. A total of 273 (83 male and 190 female patients) thyroid operations were included in this study.

RESULTS

Histopathological examination identified inadvertent parathyroidectomy in 10 (3.7%) cases. Statistical analysis identified the presence of cervical lymphadenopathy as detected by preoperative ultrasonography as a risk factor for inadvertent parathyroidectomy. In 57 patients (20.9%) clinically symptomatic postoperative hypocalcemia was observed. However, the difference in the frequency of such hypocalcemia between the patients with and without inadvertent parathyroidectomy was not significant. Statistical evaluation identified total thyroidectomy as a risk factor for postoperative hypocalcemia (p<0.005).

CONCLUSION

Due to our experience, inadvertent parathyroidectomy is not a rare entity during thyroidectomy and the presence of cervical lymphadenopathy, as observed by preoperative ultrasonography, is the only risk factor for inadvertent parathyroidectomy. In contrast, no association between inadvertent parathyroidectomy and postoperative hypocalcemia was detected. Total thyroidectomy was found to be the sole risk factor for symptomatic temporary hypocalcemia.

Polarization switching in BaTiO3thin films measured by X-ray diffraction exploiting anomalous dispersion

Films of BaTiO3ranging from 20 nm to 300 nm in thickness were grown with pulsed laser deposition on Nb:SrTiO3. The quality of the layers was investigated using atomic force microscopy, X-ray reflectivity and X-ray diffraction. Both the micrographs and the X-ray reflectivity spectra indicate a smooth surface of the layers. The X-ray diffraction profiles measured using synchrotron radiation show features characteristic for highly crystalline thin films. The application of an external electric field parallel to thecaxis changes anhklreflection of BaTiO3to anhk\bar{l} reflection. Due to the anomalous dispersion, the intensities of these two reflections are not equal and the atomic displacements can be determined from the intensity differences. The electric field-induced intensity changes can be as large as a few percent, which makes data collection from a 100 nm film using CuKα radiation from an X-ray tube feasible. The ΔI/Ivalues of a number of reflections from the 20 and 50 nm films were measured using synchrotron radiation. The observed ΔI/Ivalues were in good agreement with the intensity changes expected for polarization switching in the bulk.

A rare cause of acute abdomen: splenic infarction

Splenic infarction is a rare disorder. We have treated 4 patients during the last year. Abdominal pain in the left upper quadrant was the common complaint. Other complaints were fever, nausea and vomiting. Computed tomography showed infarcted areas in the spleen in all of the patients. Splenectomy was applied to three of the patients with recurring symptoms. The other patient had the first episode treated medically. Pulmonary embolism in one and surgical wound infection occurred in another patient during postoperative follow-up for nine (range: 4-14) months.

Retroperitoneal localization of hydatid cyst disease

In this study we discuss a rare case; hydatid cyst disease that is located in the retroperitoneum. Two cases were treated in our department with hydatid cyst disease located in the retroperitoneum; one of the cysts was in the minor pelvis and the other was on the left psoas muscle. Diagnosis was confirmed with blood tests, and radiological examinations. The cyst wall was excised partially and was oversewn. Following the operation both of the patients were given albendasole tablets for 10 weeks with blood count and liver enzyme monitorization. Hydatic cysts located in retroperitoneum were treated successfully. Especially in the endemic areas hydatid cyst should be remembered when evaluating cystic masses in the retroperitoneum. It can be treated successfully with surgery.

[Nine years of trauma cases]

Trauma is one of the major cause of death in the young population. The patients treated due to trauma were evaluated retrospectively during the last nine years. 212 cases with trauma were hospitalised in our clinic, between 1.7.1990-11.4.1999. 190 (89.6%) of them were operated and 22 (10.4%) of them were observed selectively. 36 (17%) of the cases were female and 176 (83%) of them were male. The mean age was 32.4 (16-81). 93 (43%) of them were hospitalized following traffic accidents; 56 (26.4%) of them stab wounds, 33 (15.6%) of them gunshots and 30 (14.1%) of them blunt trauma. The diagnosis was done through the diagnostic peritoneal lavage 95.1% of the traffic accident cases. The diagnosis was performed through diagnostic peritoneal lavage 76.9% of the after blunt trauma cases. After gunshots the diagnosis was done by 59.4% of the cases with physical examination. Local lesion exploration helped us to establish the diagnosis 51.4% of the stab wound cases. The most frequent organ injury following traffic accidents is splenic injury and injury of small intestine following penetrating trauma. The amount of our negative laparotomy was more than in literature and 47 (24.7%) cases were accepted as negative exploration. Negative laparotomy was seen mostly by stab wounds (49%). 17 (77.3%) of the 22 cases observed selectively were the cases of the last two years. In the recent two years the amount our negative laparotomy was six and our negative laparotomy ratio is 14%. Our mortality and the morbidity rates were at the acceptable level.