Effects of statins and cholesterol on memory functions in mice

Studies on influence of lipid lowering therapies have generated wide controversial results on the role of cholesterol on memory function. However recent studies revealed that cholesterol lowering treatment substantially reduce the risk of dementia. The objectives of this study were to analyze the effect of statins on memory function and to establish the relationship between increase/decrease in cholesterol synthesis, total cholesterol level and memory function in animals. We examined the relationship between biosynthesis of cholesterol and memory function using two statins (lipophilic simvastatin and hydrophilic pravastatin) and high cholesterol diet in mice for 15?days and 4?months. Memory performance was evaluated with two different behavioral tests and various biochemical parameters such as serum cholesterol, whole brain cholesterol, brain 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) activity and brain acetylcholine esterase (AChE) activity. We found that statin treatment for 4?months, but not for 15?days, showed significant improvement in memory function whereas high cholesterol diet showed significant impairment of memory. However long-term statin treatment showed significant decrease in serum cholesterol level as well as brain AChE level. Moreover high cholesterol diet showed significant decrease in memory function with an increase in serum cholesterol level as well as brain AChE level. There is no direct correlation between brain cholesterol level, as well as HMG-CoA activity with memory function regulation. However there is definite link between plasma cholesterol level and AChE level. A long-standing plasma cholesterol alteration may be essential to regulate memory function which in turn might be mediated through AChE modulated pathway.     

Gastrointestinal stromal tumour of the duodenum: single institution experience

Background

Primary gastrointestinal stromal tumours (GISTs) of the duodenum are rare. The aim of this study was to review the surgical management of GISTs in this anatomically complex region.

Methods

Retrospective review from January 1999 to August 2011 of patients with primary GISTs of the duodenum.

Results

Forty-one patients underwent resection of duodenal GISTs. All operations were performed with intent to cure with negative margins of resection. The most common location of origin was the second portion of the duodenum. Local excision (n = 19), segmental resection with primary anastomosis (n = 11) and a pancreatoduodenectomy (n = 11) were performed. Two patients underwent an ampullectomy with local excision. Peri-operative mortality and overall morbidity were 0 and 12, respectively. Patients with high-risk GISTs (P = 0.008) and those who underwent a pancreatoduodenectomy (P = 0.021) were at a greater risk for morbidity. The median follow-up was 18 months. Eight patients developed recurrence. High-risk GISTs and neoplasms with ulceration had the greatest risk for recurrence (P = 0.017, P = 0.029 respectively). The actuarial 3- and 5-year survivals were 85% and 74%, respectively.

Conclusion

The choice and type of resection depends on the proximity to the ampulla of Vater, involvement of adjacent organs and the ability to obtain negative margins. The morbidity depends on the type of procedure for GIST.     

Acute-on-Chronic Liver Failure: What are the Implications?

Acute-on-chronic liver failure (ACLF) is a clinical entity that is well recognized by those who care for patients with cirrhosis, however in spite of this widespread recognition, there remains little consensus with regard to definition and clinical features. While many similarities exist between ACLF and decompensated cirrhosis, there are also key differences, the implications of which are far reaching for both clinicians and patients alike. Among these differences are the possibility of a reversible component, the presence of a defined insult, prognosis, and outcomes associated with ACLF (see Fig. 1). However, for ACLF to have meaningful clinical implications, it first must be defined. If ACLF can be clearly defined and more easily recognized, then clinicians may be better able to prevent, treat, prognosticate, and counsel such patients.     

Ultrasonication assisted fabrication of a tungsten sulfide/tungstite heterostructure for ppb-level ammonia detection at room temperature

A heterostructure of WS₂/WO₃·H₂O has been prepared by partial oxidation of WS₂ nanosheets by exposing bulk WS₂ micron powder to ultrasonic waves in a bath sonicator. The as-prepared nanomaterial was used as a sensing film in an interdigitated electrode-based gas detecting device. The device was found to be specific towards ammonia gas among a group oxidizing and reducing gases. In particular, a response of as high as 11.36–254.66% was recorded for ammonia concentrations of 50 ppb to 2 ppm with excellent repeatability and reproducibility at room temperature. The response time and recovery time of the device was found to be a few tens of seconds suggesting its practicability. A plausible mechanism based on different active sites present in the receptor film is proposed and a logical reason behind its specificity towards ammonia gas is also inferred based on the Lewis acidic centers on the nano-surfaces. Overall, this proposed nanomaterial has very high potential for practical use as a room temperature ammonia sensor.

A tungsten sulfide/tungstite heterostructure is prepared via a modified liquid exfoliation technique. A chemiresistive sensor based on this nanomaterial demonstrates excellent sensitivity and selectivity towards ammonia gas even at room temperature.     

A Safe Overhang Limit for Unicompartmental Knee Arthroplasties Based on Medial Collateral Ligament Strains : An In Vitro Study

Excessive tibial component overhang during unicompartmental knee arthroplasty (UKA) may cause medial collateral ligament (MCL) impingement, which, in turn, may lead to medial knee pain [Chau et al. Tibial component overhang 226 following unicompartmental knee replacement—does it matter? The Knee. 2009;16(5):310-3]. This study examines MCL loads in 6 human cadaveric knees for different levels of overhang using a robotic testing system. The results indicated no statistically significant difference between the baseline MCL load (no overhang) and the 2-mm overhang (P = .261). However, there were significant differences in MCL load between 2- vs 4-mm (P = .012) and 2- vs 6-mm overhang (P = .022). The loads were almost doubled from 2 to 4 mm of overhang. We conclude that, to minimize pain from excessive MCL loading, surgeons should avoid tibial component overhang greater than 2 mm in unicompartmental knee arthroplasties.     

Trochlear Inclination Angles in Normal and Dysplastic Knees

Trochlear morphology impacts component position in patellofemoral arthroplasty. We devised a measurement of the trochlear inclination angle (TIA) and determined the average TIA in normal and dysplastic knees. Three hundred twenty-nine consecutive magnetic resonance imagings of normal and dysplastic knees were evaluated. The TIA was measured by 2 reviewers. The Student t test was used, and intraobserver reliability measurements were made. The mean TIA in normal and dysplastic knees was internally rotated 11.4° (range, 6°-20°) and 9.4° (range, 4°-15°), respectively. The mean TIA did not differ significantly by sex or age. Trochlear inclination angles in both normal and dysplastic knees tend toward internal rotation. Positioning a trochlear patellofemoral arthroplasty component flush with the articular surface of the native trochlea would result in internal rotation malposition.     

Prospective Study of Unplanned Admission to the Intensive Care Unit after Total Hip Arthroplasty

The morbidity associated with elective total hip arthroplasty (THA) may result in intensive care unit (ICU) admission. A total of 175 consecutive THA patients were prospectively triaged to either an ICU bed or routine post-operative floor according to admission criteria based on a prior published study of 1259 THA patients. Primary end points were a reduction in unplanned ICU admission, as well as major complications. With our triage model, the rate of unplanned ICU admissions dropped from 7.1% to 2.2% (P = 0.013). The as-treated odds of unplanned admission pre- versus post-intervention were 3.2 (1.2, 10.6). The complication rate fell from 12.5% to 2%, and the mortality index decreased from 4.77 to 1.62. Triage according to selected risk factors affects a reduction in unplanned ICU admissions and major complications after THA.     

Delirium during the course of electroconvulsive therapy in a patient on lithium carbonate treatment

Objective

The safety of concurrent mood stabilizers during the course of electroconvulsive therapy (ECT) is yet to be clearly established. Delirium with concurrent administration of ECT and lithium carbonate is described in this case report.

Methods

A 30-year-old male with a past history of significant head injury developed delirium during the course of bitemporal ECT.

Results

The clinical picture and the details of the cognitive impairment have been discussed in the report with a focus on relationship between the lithium carbonate administration and the concurrent ECT.

Conclusion

Patients with preexisting organic brain damage could be prone to develop the cognitive adverse effect while on a combination of lithium and ECT. Possible interactions between lithium and ECT need further systematic evaluation.