PINK1 mutations in sporadic early-onset Parkinson's disease.

Pathogenic PINK1 mutations have been described in PARK6-linked Parkinson's disease (PD) patients of Asian origin. However, data on the frequency of PINK1 mutations in sporadic early-onset Parkinson's disease (EOPD) Asian patients are lacking. The objectives of this study were to report the frequency of PINK1 mutations of sporadic EOPD in an Asian cohort comprising of ethnic Chinese, Malays, and Indians, and to highlight a PINK1-positive patient who presented with restless legs symptoms. Eighty consecutive sporadic EOPD patients from the movement disorder clinics of two major tertiary institutions in the country were included. We performed sequence analysis of all the coding and exon-intron junctions of the PINK1 using specific primer sets. In addition, we genotyped polymorphisms detected from the analysis in a group of sporadic PD patients and controls. Three different mutations (two homozygous nonsense and one heterozygous missense) in the putative kinase domain were found in three patients, giving a 3.7% frequency of PINK1 mutations in our EOPD cohort. All the mutations were absent in 200 healthy controls. One patient with a novel homozygous nonsense PINK1 mutation presented unusually with restless legs symptoms. Separately, analysis of the frequency of four PINK1 polymorphisms in a group of sporadic PD and controls did not reveal any significant differences. We highlight a 3.7% frequency of PINK1 mutations in an Asian cohort (ethnic Chinese, Malay, and Indian) of EOPD. The phenotypic spectrum associated with PINK1-positive patients may be wider than previously reported. Polymorphisms of PINK1 do not appear to modulate risk of PD in our population.     

Secondary closure of oroantral and oronasal fistulas: a modification of existing techniques

Fifty-three patients, 25 with oroantral and 28 with oronasal fistulas, were treated using a modified technique of peripheral de-epithelialization and overlapping flaps. This technique was used with sliding buccal flaps, palatal rotation flaps, palatal island flaps, tongue flaps, and distant tubed pedicle flaps. The advantage of the flap is that it provides more tissue attachment, which promotes healing and resists the tendency of the flap to return to its original position. A high degree of success can be predicted. Only two failures were observed in 53 cases.     

Transdermal Dual-Controlled Delivery of Contraceptive Drugs: Formulation Development,in Vitro and in Vivo Evaluations,and Clinical Performance

Several transdermal contraceptive device (TCD) formulations were developed to provide a dual-controlled transdermal delivery of levonorgestrel (LN), a potent progestin, and 17-estradiol (E₂), a natural estrogen. Using a sensitive HPLC method, the in vitro release and skin permeation profiles of LN and E₂ from various TCD formulations were simultaneously characterized in the hydrodynamically well-calibrated Valia–Chien skin permeation cells and both were found to follow zero-order kinetics. The rates of drug release and skin permeation were observed to vary significantly depending upon some formulation parameters. Six-month stability studies were performed on seven formulations at room and elevated temperatures (37 and 45°C), and two (Formulations 4 and 5) were found to be acceptable, based on drug recovery, release rate, and skin permeation rate data. Judging from the 6-month accelerated stability studies, it is projected these two formulations will have shelf-life of at least 2 years. As a result of development of an efficient manufacturing process, Formulation 4 was selected for further evaluation. One-week primary skin irritation evaluation in 6 rabbits indicated that Formulation 4 is nonirritating, and it was thus selected for Phase I clinical bioavailability/dose proportionality studies in 12 healthy female volunteers of child-bearing age. Results of pharmacokinetic and pharmacodynamic analyses demonstrated that it is capable of achieving and maintaining a steady-state serum level of LN throughout the 3-week treatment period by weekly applications of one or two TCD patches (10 or 20 cm²). A dose proportionality was obtained in the serum drug levels, daily dose delivered, and contraception efficacy. An excellent correlation was obtained for the rates of transdermal delivery determined by the in vitro studies using human cadaver skin, the in vivo studies in rabbits, and the clinical studies in living subjects.     

Structure-based pharmacophore modeling and virtual screening to identify novel inhibitors for anthrax lethal factor

Inhibition of anthrax lethal factor (LF) has been reported to be a potent strategy for the treatment of anthrax; however, no effective LF inhibitors are currently available. In this study, a structure-based pharmacophore model was developed based on the co-crystallized structure of anthrax LF with the active inhibitor GM6001. The best pharmacophore model (denoted as SB_Hypo1), consisting of two hydrogen bond acceptors, one hydrogen bond donor and one hydrophobic, was further validated using Gunner-Henry score method. The well-validated SB_Hypo1 was then used as a 3D-query in virtual screening to identify potential hits from NCI database. These hits were subsequently filtered by ADMET and validated by molecular docking experiments, and their binding stabilities were validated by 10-ns MD simulations. Finally, three hits were identified as potential leads based on their favorable binding interactions.     

Renosplenic Shunting in the Nutcracker Phenomenon: A Discussion and Paradigm Shift in Options? A Novel Approach to Treating Nutcracker Syndrome

The nutcracker syndrome is a rare clinical manifestation of symptoms caused by the compression of the left renal vein by an overriding superior mesenteric artery, an anatomical variant otherwise known as the nutcracker phenomenon. Usually present in women and children, when symptomatic, it commonly presents with hematuria, proteinuria, and chronic pelvic pain. Effective modalities of treatment apart from conservative management, include both invasive surgical procedures such as renal vein transposition and autotransplantation of the kidney and more popular recently, the less invasive endovascular stenting. Both options, however, are not without complications, such as, retroperitoneal hematomas or stent migration, thrombosis and restenosis. We now present a case of spontaneous renosplenic shunting in a 68-year-old lady of Chinese descent with the nutcracker syndrome—the first of such cases to be ever reported in a patient with no preexisting predilection for chronic liver disease and portosystemic shunting. Despite having significant pelvic venous congestion as evident on computed tomography scans, she remained asymptomatic. This may present a novel paradigm shift for the treatment of the nutcracker syndrome —surgical creation of a renosplenic bypass instead of current modalities, an alternative solution which can be performed laparoscopically and is without problems related to stent use. The creation of laparoscopic splenorenal bypass has been reported once thus far in Cleveland Ohio by Chung and Gill with good symptomatic improvement but no further studies since to validate its long-term effectiveness.     

A Novel Target and Approach for Identifying Antivirals against Molluscum Contagiosum Virus

The dermatological disease molluscum contagiosum (MC) presents as lesions restricted solely to the skin. The poxvirus molluscum contagiosum virus (MCV) is responsible for this skin disease that is easily transmitted through casual contact among all populations, with greater frequency in children and immunosuppressed individuals. In addition, sexual transmission of MCV in adolescents and adults is a health concern. Although the skin lesions ultimately resolve in immunocompetent individuals, they can persist for extended periods, be painful, and result in scarring. Treatment is problematic, and there is no drug that specifically targets MCV. The inability of MCV to propagate in cell culture has impeded drug development. To overcome these barriers, we integrated three new developments. First, we identified a new MCV drug target (mD4) that is essential for processive DNA synthesis in vitro. Second, we discovered a small chemical compound that binds to mD4 and prevents DNA synthesis in vitro. Third, and most significant, we engineered a hybrid vaccinia virus (mD4-VV) in which the natural vaccinia D4 (vD4) gene is replaced by the mD4 target gene. This hybrid virus is dependent on mD4 for viral growth in culture and is inhibited by the small compound. This target system provides, for the first time, a platform and approach for the discovery and evaluation of new therapeutics that can be used to treat MC.