Development of a Fully-automated On-line Oxidation Column-switching HPLC System for the Determination of Endogenous Melatonin in Human Clinical Samples.

A fully-automated on-line oxidation column-switching HPLC system has been developed for the determination of endogenous melatonin in human plasma and saliva. This HPLC system consists of four processes. In the first step, melatonin is fractionated using a reversed-phase C4 column (Proteonavi, 75 mm × 1.0 mm i.d.). In the second step, the obtained melatonin fraction is on-line collected, and oxidized to a highly-fluorescent compound, N-[(6-methoxy-4-oxo-1,4-dihydroquinolin-3-yl)methyl]acetamide (6-MOQMA), by mixing with hydrogen peroxide under alkaline conditions. In the third step, the produced 6-MOQMA is concentrated, and the oxidation reagents are removed using an alkaline resistive reversed-phase column, Asahipak ODP (35 mm × 1.0 mm i.d.). In the final fourth step, the 6-MOQMA is determined by a microbore-ODS column packed with ultrafine particles (CAPCELL PAK C18 IF, 250 mm × 1.0 mm i.d.). The limit of detection of melatonin using this system is about 200 amol/injection, and the determination of endogenous melatonin in a small volume of human physiological fluids, such as 100 µL of plasma and 300 µL of saliva, was successfully accomplished.

Rac1 recruitment to the archipelago structure of the focal adhesion through the fluid membrane as revealed by single-molecule analysis.

The focal adhesion (FA) is an integrin-based structure built in/on the plasma membrane (PM), linking the extracellular matrix to the actin stress-fibers, working as cell migration scaffolds. Previously, we proposed the archipelago architecture of the FA, in which FA largely consists of fluid membrane, dotted with small islands accumulating FA proteins: membrane molecules enter the inter-island channels in the FA zone rather freely, and the integrins in the FA-protein islands rapidly exchanges with those in the bulk membrane. Here, we examined how Rac1, a small G-protein regulating FA formation, and its activators αPIX and ßPIX, are recruited to the FA zones. PIX molecules are recruited from the cytoplasm to the FA zones directly. In contrast, majorities of Rac1 molecules first arrive from the cytoplasm on the general inner PM surface, and then enter the FA zones via lateral diffusion on the PM, which is possible due to rapid Rac1 diffusion even within the FA zones, slowed only by a factor of two to four compared with that outside. The constitutively-active Rac1 mutant exhibited temporary and all-time immobilizations in the FA zone, suggesting that upon PIX-induced Rac1 activation at the FA-protein islands, Rac1 tends to be immobilized at the FA-protein islands.

Patients with 47, XXX karyotype who experienced premature ovarian failure (POF): two case reports.

PURPOSE: Pubertal onset and sexual development are usually normal in 47, XXX individuals; however, we report two cases of premature ovarian failure (POF) in infertile women with trisomy X. METHODS: Chromosome analysis was conducted with G-banding and fluorescence in situ hybridization using X- and Y-bearing probe. Hormonal administration was primarily Kaufmann's treatment or long-term estradiol treatment, followed by withdrawal bleeding from estrogen and progesterone. RESULTS: Two patients with trisomy X, aged 31 (patient 1) and 27 years (patient 2), were diagnosed with POF due to hypergonadotropic hypogonadism. Their ovaries were small. Patient 1 had a FSH level of 44.6 mIU/ml and patient 2 had a FSH level of 74.6 mIU/ml. In patient 1, with Kaufmann's treatment, the FSH decreased to 13.5 mIU/ml; however, follicle growth did not occur following HMG stimulation. In patient 2, FSH did not decrease despite Kaufmann's treatment; therefore, she was given a GnRH agonist and her FSH level decreased to 7.1 mIU/ml. However, her ovaries never responded to HMG stimulation. CONCLUSION: We report on two patients with a 47, XXX karyotype who became infertile due to POF. We recommend that when a patient is diagnosed with trisomy X, the possibility of POF must be strongly considered.

Sensitization of hyperthermic treatment of leukemic cell lines by a synthetic peptide.

A compound named HPH-Pep, a peptide constructed from pyridine and histidine units, showed sensitizing effect on the hyperthermic treatment of L-1210, Molt-4, and HL60 cells. The survival rate of these cells was greatly reduced by combined treatment with heating at 44 degrees C and HPH-pep. The treatment of L-1210 and Molt-4 cells with HPH-Pep resulted in a significant breakdown of the survival rate at 44 degrees C. The cell death induced by HPH-Pep under hyperthermic condition seemed to involve iron and peroxide.