Catalysis leads to posttranslational inactivation of the type 1 deiodinase and alters its conformation

Previously, it was shown that the type 1 deiodinase (D1) is subject to substrate-dependent inactivation that is blocked by pretreatment with the inhibitor of D1 catalysis, propylthiouracil (PTU). Using HepG2 cells with endogenous D1 activity, we found that while considerable D1-mediated catalysis of reverse tri-iodothyronine (rT(3)) is observed in intact cells, there was a significant loss of D1 activity in sonicates assayed from the same cells in parallel. This rT(3)-mediated loss of D1 activity occurs despite no change in D1 mRNA levels and is blocked by PTU treatment, suggesting a requirement for catalysis. Endogenous D1 activity in sonicates was inactivated in a dose-dependent manner in HepG2 cells, with a ～50% decrease after 10?nM rT(3) treatment. Inactivation of D1 was rapid, occurring after only half an hour of rT(3) treatment. D1 expressed in HEK293 cells was inactivated by rT(3) in a similar manner. (75)Se labeling of the D1 selenoprotein indicated that after 4?h rT(3)-mediated inactivation of D1 occurs without a corresponding decrease in D1 protein levels, though rT(3) treatment causes a loss of D1 protein after 8-24?h. Bioluminescence resonance energy transfer studies indicate that rT(3) exposure increases energy transfer between the D1 homodimer subunits, and this was lost when the active site of D1 was mutated to alanine, suggesting that a post-catalytic structural change in the D1 homodimer could cause enzyme inactivation. Thus, both D1 and type 2 deiodinase are subject to catalysis-induced loss of activity although their inactivation occurs via very different mechanisms.     

Surgical management of pneumosinus dilatans frontalis in the setting of chronic rhinosinusitis and type III frontal Cell

Pneumosinus dilatans (PD) represents a rare lesion of unknown etiology in which progressive enlargement of an air-filled paranasal sinus results in cosmetic and functional complications. The absence of pathologic mucosa has traditionally been considered a hallmark of this disorder. A 24-year-old man presented with 2 years of chronic rhinosinusitis and recurrent, acute episodes of severe forehead pain with worsening outward prominence of the frontal sinus during air travel. Computed tomography and findings at surgery were notable for diffuse nonpolypoid inflammatory changes of the paranasal sinuses, a type III frontal sinus cell, and PD of the frontal sinus with severe deformity and thinning of the anterior table. A bicoronal approach was used for frontal sinus obliteration and cranioplasty. Excellent cosmetic and functional results were noted at the last follow-up. To our knowledge, this is the first report of PD frontalis presenting in the setting of chronic rhinosinusitis. Surgical management of this disorder requires consideration of both the functional and cosmetic issues.     

Assessment of dental anxiety and its correlation with denture satisfaction in edentulous patients

Objective: The objectives of this study were to measure the level of dental anxiety and its correlation with dental history, denture satisfaction and other variables. Materials and methods: A cross-sectional study was conducted on 150 completely edentulous patients reporting to the Department of Prosthodontics, KLES's Institute of Dental Sciences, Belgaum, over a period of 17 months (August 2005 to March 2007). The anxiety level of the patients was assessed with the help of a questionnaire, after obtaining an informed consent. Reliability of the dental anxiety scale was assessed by means of coefficient alpha. Results: The results of this study concluded that dental anxiety scale for edentulous patients was a reliable scale for measuring dental anxiety. The anxiety score was higher for female than male patients. A significant correlation was found between denture satisfaction score and anxiety. Discussion: Anxiety plays a major role in denture satisfaction. The variables included: Previous denture experience, occupation, medical history, age, gender, dental anxiety scale, period of edentulousness, age of previous dentures, number of complete dentures, denture satisfaction score, and the score on the Hamilton anxiety scale Conclusion: The study indicated that gender correlates significantly with dental anxiety. Patients with medical history were found to be more anxious than normal patients. Patients with higher anxiety values were less satisfied with the treatment. Lastly, subjects with higher general anxiety showed greater values on the dental anxiety scale. Clinical significance: The assessment of dental anxiety will help the prosthodontist in the management of anxious patients and secondly to provide evidence-based research into this psychological construct which has been shown to predict dental avoidance. Keywords: Dental anxiety, Denture satisfaction, Completely edentulous patients. How to cite this article: Shrivastava R, Srivastava R, Shigli K, Prashanth MB, Kumaraswamy BN, Nethravathi TD. Assessment of Dental Anxiety and its Correlation with Denture Satisfaction in Edentulous Patients. J Contemp Dent Pract 2012;13(3):257-260. Source of support: Nil Conflict of interest: None declared.     

Characterization of microsatellite loci for Cypripedium kentuckiense (Orchidaceae)

Cypripedium kentuckiense is one of the 15 Cypripedium species found in North America. Its populations are threatened by illegal collection and land conversion. Assessing the level of genetic variation within-and-among populations employing species-specific and variable co-dominant molecular markers such as microsatellite can assist in developing appropriate conservation strategies. For the first time, we report eight polymorphic nuclear microsatellite markers for C. kentuckiense. Number of alleles per locus ranged from two to eight and the mean number of alleles across eight loci was 4.13. Mean observed (H _o ) and expected heterozygosity (H _e ) values were 0.514 and 0.522, respectively. The eight markers reported in this study can be used to estimate genetic diversity, genetic structure, gene flow, and mating system of the species.     

Pulmonary embolectomy with use of pediatric bronchoscope for the detection of residual emboli: an innovative surgical technique

Pulmonary embolectomy in the treatment of massive pulmonary embolus has been in doubt since the introduction of thrombolytic therapy. Recent indications for surgical intervention are- contraindication to thrombolysis, failed medical treatment and severe Right Ventricular (RV) dysfunction. A 54-year male came to us with complaints of palpitation, tachypnea and repeated syncope . Transthoracic echocardiography and Computed Tomography pulmonary angiogram demonstrated- Biatrial mass with right atrial mass extending into right ventricle and main pulmonary artery. Pulmonary embolectomy was performed. Residual emboli of bilateral pulmonary arteries were detected with a fiberoptic pediatric bronchoscope and removed. Bronchoscopic evaluation appears to be safe and useful for direct visual detection of emboli.     

Elective hip and knee arthroplasty and the effect of rivaroxaban and enoxaparin thromboprophylaxis on wound healing

Introduction

Rivaroxaban is the first licensed oral direct inhibitor of factor Xa. Recent studies from the RECORD trials suggest rivaroxaban has superior efficacy compared to enoxaparin in preventing venous thromboembolism (VTE) with no significant increase in the major bleeding risk. Concerns remain regarding the incidence of minor bleeding, consequent delayed wound healing and subsequent risk of infection. The aim of this observational study was to assess the incidence of post-operative complications in patients receiving either rivaroxaban or enoxaparin thromboprophylaxis following elective hip and knee arthroplasty.

Methods

A total of 258 patients undergoing elective total hip or knee arthroplasty within one NHS Trust were included. A total of 202 subjects (mean age, 70.7 years ± 10.0, 43 % men) received a daily dose of 10 mg of oral rivaroxaban and 56 (mean age, 70.9 years ± 9.8, 39 % men) had a daily subcutaneous injection of 40 mg of enoxaparin as thromboprophylaxis. Endpoints included VTE (deep vein thrombosis and pulmonary embolism), haemorrhagic wound complications, hospital re-admission, requirement for blood transfusion, minor and major bleeding and death.

Results

There were no significant differences in the incidence of VTE, requirement for blood transfusion and readmission rate between rivaroxaban and enoxaparin-treated patients. The incidence of minor bleeding (2.0 vs. 0 %) and haemorrhagic wound complications (5.0 vs. 1.8 %) were non-significantly higher in the rivaroxaban-treated group. There were no cases of pulmonary embolism, major bleeding or death in either group.

Conclusion

Our experience with rivaroxaban in elective hip and knee arthroplasty showed no significant difference in the incidence of VTE or major bleeding. There was, however, a tendency to greater risk of minor bleeding and wound complications that were largely haemorrhagic in nature, which may have reached significance in a larger study.     

Adenoid cystic carcinoma of female breast: A case report

INTRODUCTIONAdenoid cystic carcinoma (ACC) of the breast is a rare neoplasm accounting for 0.1% of breast carcinomas.PRESENTATION OF CASEA 30 year old female patient presented with multiple lumps in the right breast. Excision biopsy of a lump in the lower outer quadrant revealed adenoid cystic carcinoma. A right sided modified radical mastectomy (MRM) was performed, with axillary clearance. Histopathology revealed a fibroadenoma accounting for one mass and adenoid cystic carcinoma in another, confirmed on Periodic acid Schiff (PAS) staining. Three out of the eight excised axillary lymph nodes contained malignancy. There was no evidence of recurrence or distant spread at follow-up 6 months postoperatively.DISCUSSIONACC of the breast is a rare neoplasm accounting for 0.1% of breast carcinomas and is of special interest because of its favourable prognosis and distinctive histological appearance. This tumor occurs predominantly in women in their sixth decade and usually presents as a tender breast mass, often in the subareolar area though in our case it was not tender and presented as multiple lumps in the right breast. The diagnosis can be made on fine needle aspiration cytology (FNAC), but in our case FNAC was inconclusive. We performed MRM with axillary clearance, and three out eight lymph nodes proved positive for malignancy.CONCLUSIONACC is a rare malignant neoplasm. Surgical treatment is the mainstay with little role for radiotherapy and chemotherapy according to the published literature.     

Primary angiosarcoma of breast: A case report

INTRODUCTIONPrimary breast angiosarcoma is a rare form of breast cancer, accounting for only 0.04% of all malignant breast tumours.PRESENTATION OF CASEA 28-year-old woman presented with a progressive lump in the right breast for one month. Fine needle aspiration cytology (FNAC) was highly suspicious of angiosarcoma, and this diagnosis was confirmed on core needle biopsy. Modified radical mastectomy was performed as sole treatment.DISCUSSIONPrimary breast angiosarcoma is a rare type of breast malignancy, usually occurring in the third to fourth decade and only reported in women. The histological features of angiosarcoma of the breast are conventionally graded I, II or III. Total mastectomy appears to be the only treatment conferring benefit, chemotherapy and radiation therapy being of little proven value to date. The 5-year disease-free survival for grade I tumours can be as high as 76%, and up to 70% for grade II tumours whereas for grade III tumours it is reportedly about 15%.CONCLUSIONPrimary angiosarcoma of the breast is a rare malignancy with a poor prognosis, even after complete resection. Surgery is the mainstay of treatment with a limited role for chemotherapy and radiotherapy.     

β‐amyloid and ATP‐induced diffusional trapping of astrocyte and neuronal metabotropic glutamate type‐5 receptors

β‐Amyloid (Aβ) oligomers initiate synaptotoxicity following their interaction with the plasma membrane. Several proteins including metabotropic glutamate type 5 receptors (mGluR5s) contribute to this process. We observed an overexpression of mGluR5s in reactive astrocytes surrounding Aβ plaques in brain sections from an Alzheimer's disease mouse model. In a simplified cell culture system, using immunocytochemistry and single molecule imaging, we demonstrated a rapid binding of Aβ oligomers on the plasma membrane of astrocytes. The resulting aggregates of Aβ oligomers led to the diffusional trapping and clustering of mGluR5s. Further, Aβ oligomers induced an increase in ATP release following activation of astroglial mGluR5s by its agonist. ATP slowed mGluR5s diffusion in astrocytes as well as in neurons co‐cultured with astrocytes. This effect, which is purinergic receptor‐dependent, was not observed in pure neuronal cultures. Thus, Aβ oligomer‐ and mGluR5‐dependent ATP release by astrocytes may contribute to the overall deleterious effect of mGluR5s in Alzheimer's disease. GLIA 2013;61:1673–1686