α-[11C] methyl-L tryptophan-PET as a surrogate for interictal cerebral serotonin synthesis in migraine without aura

Background

Alteration in central serotonin biology has been implicated in migraine, and serotonin (5-HT) agonists have been available for more than a decade in the treatment of that condition.

Objectives

To test this hypothesis, we studied in vivo using positron-emission tomography (PET) and α-[11C] methyl-L-tryptophan (α-[11C]MTrp) as a surrogate marker of cerebral 5-HT synthetic rate before and after administration of eletriptan in migraine and control subjects.

Methods

Six nonmenopausal female migraine subjects with migraine without aura (MoA) and six nonmenopausal age-matched female control subjects were scanned at baseline and after oral administration of 40 mg of eletriptan. Migraine subjects at the time of PET had to have been headache free for a minimum of three days. Images of (α-[11C]MTrp) brain trapping were colocalized with individual MRI images in three dimensions and analyzed.

Results

There was no difference in baseline cerebral global 5-HT synthesis between migraine and control subjects. After administration of eletriptan, there was a striking global reduction in cerebral 5-HT synthesis (K*) in the migraine group and in 22 regions of interest (ROIs). In control subjects, no significant changes were found in global cerebral 5-HT synthesis (K*) or in any of the ROIs.

Conclusions

These findings suggest in migraine an interictal alteration in the regulation mechanisms of cerebral 5-HT synthesis.

The effect of risedronate (17.5 mg/week) treatment on quality of life in Japanese women with osteoporosis: a prospective observational study

A prospective observational study to test the effects of risedronate 17.5 mg/week treatment on quality of life (QOL) of 1,363 Japanese female patients with osteoporosis showed QOL improvement after 12 weeks of administration. Comorbid factors such as ischemic heart disease, hip osteoarthritis, and higher values of FRAX blunted the effects of QOL of the treatment. Few studies have investigated the effect of osteoporosis treatment on QOL in relationship to comorbid factors other than osteoporosis and fracture. Efficacy was determined by changes over time in EQ-5D at baseline, at 12 and 24 weeks, and at the final assessment. Factors affecting changes in EQ-5D were evaluated with a multivariate analysis. Safety was determined by assessing the incident rate of adverse events. The improvement of EQ-5D compared to baseline was observed as significant after 12 weeks of treatment (p < 0.001). The greatest improvement was observed in the dimension of "pain/discomfort" by the multivariate analysis (p < 0.001). Factors affecting QOL improvement were FRAX value without BMD, age, glucocorticoid use, ischemic heart disease, hip osteoarthritis, and pain. The incidence rate of drug-related adverse events was 4.72 % (95 % confidence interval 3.63-6.02 %). Risedronate at 17.5 mg/week improved the QOL in patients with osteoporosis among Japanese women, and comorbidity factors decreased the effects.

Functional coupling of cerebral ?-aminobutyric acid (GABA)(B) receptor with adenylate cyclase system: effect of phaclofen

Using synaptic membrane from bovine cerebral cortex, effects of ?-aminobutyric acid (GABA), (?)-baclofen, and phaclofen on the cyclic AMP formation mediated by adenylate cyclase were studied. In addition, the binding affinity of phaclofen, a GABA(B) antagonist, to synaptic membrane was compared with those of GABA and (?)-baclofen. GABA and (?)-baclofen, GABA(B) receptor agonists, induced significant inhibitions on the basal and forskolin-stimulated adenylate cyclase activities. Treatment of synaptic membrane with the islet-activating protein, pertussis toxin, completely eliminated the inhibitory effects of GABA and (?)-baclofen on the forskolin-stimulated adenylate cyclase activity. In solubilized fraction of synaptic membrane, the forskolin-stimulated adenylate cyclase was no longer affected by the additions of GABA and (?)-baclofen. Phaclofen displaced 50% of the bound [(3)H](?)-baclofen from synaptic membrane at the concentration of 10(?3) M, and also completely abolished inhibitory effects of GABA and (?)-baclofen on the forskolin-stimulated adenylate cyclase activity. These results suggest that GABA(B) receptor in synaptic membrane of the bovine cerebral cortex may be functionally coupled with adenylate cyclase system via Ni and/or No proteins. The present results also suggest that phaclofen may have selective affinity to the same binding sites as those of GABA(B) receptor agonists such as (?)-baclofen, and induce a suppressive effect on GABA(B) receptor mediated inhibition of adenylate cyclase.

Engineering of implantable liver tissues

In this chapter, from the engineering point of view, we introduce the results from our group and related research on three typical configurations of engineered liver tissues; cell sheet-based tissues, sheet-like macroporous scaffold-based tissues, and tissues based on special scaffolds that comprise a flow channel network. The former two do not necessitate in vitro prevascularization and are thus promising in actual human clinical trials for liver diseases that can be recovered by relatively smaller tissue mass. The third approach can implant a much larger mass but is still not yet feasible. In all cases, oxygen supply is the key engineering factor. For the first configuration, direct oxygen supply using an oxygen-permeable polydimethylsiloxane membrane enables various liver cells to exhibit distinct behaviors, complete double layers of mature hepatocytes and fibroblasts, spontaneous thick tissue formation of hepatocarcinoma cells and fetal hepatocytes. Actual oxygen concentration at the cell level can be strictly controlled in this culture system. Using this property, we found that initially low then subsequently high oxygen concentrations were favorable to growth and maturation of fetal cells. For the second configuration, combination of poly-L: -lactic acid 3D scaffolds and appropriate growth factor cocktails provides a suitable microenvironment for the maturation of cells in vitro but the cell growth is limited to a certain distance from the inner surfaces of the macropores. However, implantation to the mesentery leaves of animals allows the cells again to proliferate and pack the remaining spaces of the macroporous structure, suggesting the high feasibility of 3D culture of hepatocyte progenitors for liver tissue-based therapies. For the third configuration, we proposed a design criterion concerning the dimensions of flow channels based on oxygen diffusion and consumption around the channel. Due to the current limitation in the resolution of 3D microfabrication processes, final cell densities were less than one-tenth of those of in vivo liver tissues; cells preferentially grew along the surfaces of the channels and this fact suggested the necessity of improved 3D fabrication technologies with higher resolution. In any case, suitable oxygen supply, meeting the cellular demand at physiological concentrations, was the most important factor that should be considered in engineering liver tissues. This enables cells to utilize aerobic respiration that produces almost 20 times more ATP from the same glucose consumption than anaerobic respiration (glycolysis). This also allows the cells to exhibit their maximum reorganization capability that cannot be observed in conventional anaerobic conditions.