G2019S LRRK2 mutation in familial and sporadic Parkinson's disease in Russia.

Among mutations associated with autosomal dominant and sporadic Parkinson's disease (PD) the G2019S substitution in the leucine-rich repeat kinase 2 (LRRK2) gene is the most frequently identified. To estimate its frequency in Russia, we analyzed 208 patients with PD from the Northwestern region of Russia. Of these, 51 patients were probands from families with PD compatible with autosomal dominant inheritance. The control group represented 161 subjects without neurological disorders settled in the same region. The frequency of the G2019S mutation was greater in familial PD (2 [3.9%] of 51) than in sporadic PD (1 [0.6%] of 157). In addition, this mutation was found in the proband's father, who also had PD, in 1 PD family, and in 1 carrier without signs of PD at age 40 in another PD family. All carriers were heterozygous for the G2019S mutation and reported the Ashkenazi Jewish origin. The mutation was not found in the control group.     

Molecular Modeling Evidence for His438 Flip in the Mechanism of Butyrylcholinesterase Hysteretic Behavior

Cholinesterases display a hysteretic behavior with certain substrates and irreversible inhibitors. For years, this behavior has remained puzzling. However, several lines of evidence indicated that it is caused by perturbation of the catalytic triad and its water environment. In the present study, using molecular dynamics simulations of Ala328Cys BuChE mutant and wild-type BuChE in the absence and presence of a co-solvent (sucrose, glycerol), we provide evidence that hysteresis originates in a flip of the catalytic triad histidine (His438). This event is controlled by water molecules that interact with active site residues. The physiological significance of this phenomenon is still an issue.     

Apoptosis-based evaluation of chemosensitivity in ovarian cancer patients

OBJECTIVE: Induction of apoptosis in target cells is a key mechanism by which chemotherapy induces cell killing. We have established an in vitro system for determining the chemosensitivity of epithelial ovarian cancer cells to carboplatin and paclitaxel (Taxol). Practical assays to predict the likelihood of individual tumor sensitivity are needed to facilitate the choice of adequate treatment. We sought to determine whether epithelial ovarian cancer cells (EOC) collected from the ascites fluid of patients known to be clinically chemosensitive or chemoresistant to carboplatin and paclitaxel would show a similar response to chemotherapeutic drugs after in vitro treatment. METHODS: Thirteen patients with stage III and IV ovarian cancer treated with carboplatin and paclitaxel were studied. Caspase-3 activation was used as a surrogate marker for activation of chemotherapy-induced programmed cell death. We compared the in vitro apoptotic response to the clinical response of the patients from whom the tumor cells were isolated. Clinical sensitivity was defined as no evidence of disease recurrence for 6 months after optimal debulking surgery and completion of chemotherapy. RESULTS: Of seven chemosensitive patients, five cell samples treated in vitro had increased caspase-3 activity in response to both carboplatin and paclitaxel. Five of six chemoresistant cases did not show caspase-3 activity in response to only one or to neither agent. CONCLUSION: Quantifiable markers of apoptosis such as caspase-3 activation have the potential to predict the clinical response to chemotherapy. Application of this assay in clinical laboratories could optimize the potential for efficient treatment and avoid the toxicities of ineffective drugs.     

Bullous oral lichen planus: report of two cases

Lichen planus is a common chronic mucocutaneous disease of unknown cause. Several types of lichen planus (reticular, atrophic, erosive and bullous) within the oral cavity have been described, among which the reticular and erosive types are the most common types,1,2 while the bullous type is rarely observed.1,3 Bullous lichen planus (BLP) lesions are commonly seen on the buccal mucosa, most frequently at the posterior areas adjacent to the second and third molar teeth. Less common localizations are gingiva and inner aspect of the lips.4 Bullae are generally short lived and leave ulcerated lesions on rupturing.1 The clinical diagnosis of bullous lichen planus is extremely difficult, and pathological examinations may be necessary to establish a definitive diagnosis.5     

The Role of Nonvitamin K Antagonist Oral Anticoagulants (NOACs) in Stroke Prevention in Patients with Atrial Fibrillation

Anticoagulation is important in stroke prevention in patients with atrial fibrillation. Until recently, heparins and vitamin K antagonists were the only available therapy for stroke reduction in atrial fibrillation (AF) patients. Non-vitamin K antagonist oral anticoagulants (NOACs) including direct thrombin inhibitor (dabigatran) and direct factor Xa inhibitors (rivaroxaban, apixaban and edoxaban) are now available and offer new options for stroke prevention. This article reviews the available data on the use of NOACs for primary and secondary stroke prevention in AF patients and describes specific patient populations to guide clinician in making the informed decision regarding appropriate use of those agents. It also addresses the use of NOACs early after acute stroke and use of thrombolysis while on NOAC.