A two-vessel aortic arch: Rare configuration with bilateral brachiocephalic arteries

We present a case of type B aortic dissection with a rare aortic arch branching variation whereby two separate brachiocephalic trunks arise from the arch. This case also highlights the potential implications of this variant in the management of thoracic aortic dissections and aneurysms.     

Induction of renin activity by gonadotropic hormones in cultured Leydig tumor cells

The hormonal regulation of renin activity in cloned and cultured Leydig tumor cells (designated MA-10) was examined. The treatment of Leydig cell cultures with bovine LH (bLH), hCG, or with (Bu)2cAMP elicited a dose- and time-dependent induction of renin activity and a concomitant increase in steroid biosynthesis. The optimum concentration of hCG was 25 ng/ml, which caused an average 25-fold increase in renin activity compared to the control value. bLH action was optimum at 75-100 ng/ml and induced an approximately 35-fold increase in renin activity. The maximum inducible level of renin activity was attained after 8-9 h of hormone treatments. The addition of progesterone (the major steroid product of the MA-10 cells) did not induce a significant increase in renin activity. Treatment of MA-10 cells with epidermal growth factor also failed to produce any increase in renin activity. The optimum concentration of (Bu)2cAMP was 800 microM for the induction of renin activity and caused an approximately 40-fold increase compared to the control value. Renin activity induced by bLH, hCG, or (Bu)2cAMP was completely inhibited by mouse anti-renin antibody, indicating the specific nature of renin. Upon withdrawal of (Bu)2cAMP from the culture medium, renin activity gradually declined to the control level, and with retreatment of these cultures with (Bu)2cAMP, a newly induced state of enzyme activity was resumed. Indirectly, the role of new protein and RNA synthesis was examined during hormonal regulation of renin induction using protein and RNA synthesis inhibitors such as cycloheximide, puromycin, actinomycin D, or rifampicin. Both protein and RNA synthesis inhibitors blocked the induction of renin activity in the presence of all three inducing agents, bLH, hCG, or (Bu)2cAMP. The results provide evidence that the induction of renin activity is modulated by bLH, hCG, or (Bu)2cAMP and represent the de novo synthesis of enzyme molecules.     

Dual antiplatelet therapy plus postoperative heparin and dextran is safe and effective for reducing risk of embolic stroke during aneurysm coiling

Background

Thromboembolic events represent a clinically significant cause of neurological morbidity during the endovascular management of cerebral aneurysms. We have implemented an anti-thromboembolic regimen consisting of pre- and postoperative dual antiplatelet therapy, as well as postoperative anticoagulation using heparin and dextran. The aims of our study were to examine the effect of this regimen on thromboembolic rates during elective aneurysm coiling, and to elucidate risk factors associated with the development of thromboembolic events in this setting.

Methods

We conducted a retrospective review of patients who underwent elective intracranial aneurysm coiling between January 2005 and February 2012. The primary outcome of interest was the occurrence of a clinically significant peri-procedural thromboembolic event. Secondary outcomes included the occurrence of a central nervous system (CNS) or systemic hemorrhage.

Results

During the study period, 312 patients underwent elective aneurysm coiling and six (2 %) thromboembolic events occurred; three (1 %) occurred in the group that received the anti-thromboembolic regimen (261 patients) and three (6 %) occurred in the group that did not receive the regimen (51 patients), resulting in a statistically significant difference (P?=?0.024). Both the presence of a hypercoagulable state (P?=?0.014) and the lack of the anti-thromboembolic regimen (P?=?0.043) were significantly associated with the occurrence of a thromboembolic event.

Conclusions

This study provides evidence that the regimen described here is safe and reduces thromboembolic complications during elective aneurysm coiling. Ours is likely the most aggressive regimen in the published literature and significantly reduced the rate of thromboembolism without any significant increase hemorrhagic complications.     

Toxicity evaluation and nasal mucosal tissue deposition of dexamethasone-infused mucoadhesive in situ nasal gelling systems

To demonstrate safety of a developed intranasal dexamethasone-infused in situ gelling formulation, quantification of a validated clinical biomarker indicative of cytotoxic potential using a human sinonasal explant model was first confirmed. Systematic cytotoxicity studies using the lactate dehydrogenase (LDH) detection assay revealed no elevation from baseline, in LDH levels, with tissue integrity of explanted human nasal mucosa also maintained; this was further corroborated using tissue histopathological examination. Next, with safety confirmed ex vivo, freshly excised human nasal tissue was utilised to quantify dexamethasone release from the lead sol–gel systems; this being achieved through development and validation of a HPLC-UV analytical method, which reliably quantified controlled therapeutic release and deposition into mucosal tissue. Collectively, these findings indicate promise in the safety of each excipient within the concentrations employed in the functional sol–gel system, complemented by successful and reliable drug release and deposition into human nasal mucosal tissue. These findings pave the way for application of the dexamethasone-based sol–gel system to the extended delivery of corticosteroids to nasal mucosa in the management of localised inflammatory conditions of an acute and chronic nature, such as chronic rhinosinusitis, which can be expected to benefit from controlled and extended drug delivery characteristics imparted by appropriately engineered in situ gelling systems.     

Squamous cell carcinoma arising from pilonidal sinus

Pilonidal sinus is usually present in the sacrococcygeal region. The common presentations are cellulitis, abscess or sinus. Rarely malignant change may be seen in chronic pilonidal sinus. We report a case of chronic pilonidal sinus complicated with squamous cell carcinoma.