Changes in motor cortical excitability induced by paired associative stimulation.

OBJECTIVE: Changes in afferent input have been shown to be capable of inducing reorganisations of motor cortex in humans. Using TCMS we examined the efficacy of a new associative afferent stimulation paradigm in inducing motor cortical reorganisation in humans. METHODS: Using TCMS, stimulus response curves were constructed before and following a 1 h period of associative stimulation of two muscles motor points. The effect of an asynchronous peripheral stimulation paradigm was investigated in a separate series of control experiments. RESULTS: One hour of associative stimulation of two muscles motor points resulted in a significant increase in the excitability of the corticospinal projection to those stimulated muscles. The increase in excitability peaked 1 h following the stimulation period. This increase in excitability did not generalise to either adjacent or more remote muscles. The control stimulation paradigm produced no significant change in corticospinal excitability. CONCLUSIONS: These results confirm the importance of associative input for the induction of plasticity in the human motor cortex. SIGNIFICANCE: The findings reported here further elucidate the role of afferent input in motor cortical reorganisation. These findings have implications for our understanding of the mechanisms of motor learning and may also be relevant to the design of new afferent stimulation therapies.     

Plerixafor, a CXCR4 antagonist for the mobilization of hematopoietic stem cells

Stem cells harvested from peripheral blood are the most commonly used graft source in hematopoietic stem cell transplantation. While G-CSF is the most frequently used agent for stem cell mobilization, the use of G-CSF alone results in suboptimal stem cell yields in a significant proportion of patients undergoing autologous transplantation. Plerixafor (AMD3100, Genzyme Corporation) is a bicyclam molecule that antagonizes the binding of the chemokine stromal cell-derived factor-1 (SDF-1) to its cognate receptor CXCR4. Plerixafor results in the rapid and reversible mobilization of hematopoietic stem cells into the peripheral circulation and is synergistic when combined with G-CSF. In clinical studies of autologous stem cell transplantation, the combination of plerixafor and G-CSF allows the collection of large numbers of stem cells in fewer apheresis sessions and can salvage those who fail G-CSF mobilization alone.     

Analogues of acifran: agonists of the high and low affinity niacin receptors, GPR109a and GPR109b

Recently identified GPCRs, GPR109a and GPR109b, the high and low affinity receptors for niacin, may represent good targets for the development of HDL elevating drugs for the treatment of atherosclerosis. Acifran, an agonist of both receptors, has been tested in human subjects, yet until recently very few analogs had been reported. We describe a series of acifran analogs prepared using newly developed synthetic pathways and evaluated as agonists for GPR109a and GPR109b, resulting in identification of compounds with improved activity at these receptors.     

Effect of Extremely Low Frequency Electromagnetic Fields (EMF) on Phospholipase Activity in the Cultured Cells

This study was conducted to investigate the effects of extremely low frequency electromagnetic fields (EMF) on signal pathway in plasma membrane of cultured cells (RAW 264.7 cells and RBL 2H3 cells), by measuring the activity of phospholipase A₂ (PLA₂), phospholipase C (PLC) and phospholipase D (PLD). The cells were exposed to the EMF (60 Hz, 0.1 or 1 mT) for 4 or 16 h. The basal and 0.5 µM melittin-induced arachidonic acid release was not affected by EMF in both cells. In cell-free PLA₂ assay, we failed to observe the change of cPLA₂ and sPLA₂ activity. Also both PLC and PLD activities did not show any change in the two cell lines exposed to EMF. This study suggests that the exposure condition of EMF (60 Hz, 0.1 or 1 mT) which is 2.4 fold higher than the limit of occupational exposure does not induce phospholipases-associated signal pathway in RAW 264.7 cells and RBL 2H3 cells.     

Temporary hair removal in patients with hirsutism: a clinical study

Women with facial hirsutism are burdened with hairs that often interfere with personal and work activities. Temporary hair removal is a major component in the management of hirsute patients. From a caseload of 1,000 patients, we submitted questionnaires to 271 and interviewed 135. We found that shaving was the most helpful and most frequently used temporary method. Judicious plucking can be helpful if tolerated, but care must be taken to avoid folliculitis, pigmentation, and scarring. Waxing and depilatories were used by less than 6 percent of patients on the face and by about 20 percent on other parts of the body. The avoidance of irritants and the use of hydrocortisone 1 percent cream are important in the management of any irritation due to hair removal techniques. Cosmetic coverups may be helpful.     

Femtosecond phacoemulsification: the business and the medicine

PURPOSE FOR REVIEW: Phacoemulsification is the preferred method for cataract surgery in the developed world. The number of phacoemulsification procedures performed annually is expected to increase as the population ages. Femtosecond cataract surgery offers several surgical advantages over conventional phacoemulsification and has already attained commercial application in some countries. The purpose of this review is to outline the benefits, risks and commercial issues of femtosecond lasers as applied to cataract surgery. RECENT FINDINGS: Cataract surgeons are adopting femtosecond technology to perform laser capsulotomy, lens fragmentation, clear cornea incisions and limbal relaxing incisions. Femtosecond lasers clearly perform these surgical steps with greater precision and reproducibility. Further benefits such as improved postoperative refractive results and reduced complication rates are being investigated. Commercial issues have invariably arisen such as cost of installation and operation, value proposition and return on investment. SUMMARY: Femtosecond cataract surgery is an evolving procedure that can potentially lead to better and safer surgical outcomes. This review presents the currently available scientific evidence and discusses some of the relevant financial issues concerning this technology.