Cesium reversibly suppresses HeLa cell proliferation by inhibiting cellular metabolism.

The aim of the present study was to investigate the influence of Cs+ on cultured human cells. We find that HeLa cell growth is suppressed by the addition of 10 mm CsCl into the culture media. In the Cs+ -treated cells, the intracellular Cs+ and K+ concentrations are increased and decreased, respectively. This leads to a decrease in activity of the glycolytic enzyme pyruvate kinase, which uses K+ as a cofactor. Cs+ -treated cells show an intracellular pH shift towards alkalization. Based on these results, CsCl presumably suppresses HeLa cell proliferation by inducing an intracellular cation imbalance that affects cell metabolism. Our findings may have implications for the use of Cs+ in cancer therapy.

Capillary isoelectric focusing after sample enrichment with immunoaffinity chromatography in a single capillary.

For accurate micro-scale quantification of a specific protein in biological fluids, immunoaffinity chromatography (IAC) and isoelectric focusing (IEF) were combined in a single fused-silica capillary. The inner wall of the capillary was coated with an anti-E-tag antibody at the inlet side to form an IAC column, and polydimethylacrylamide, a neutral polymer, at the outlet side to form the capillary for IEF. After loading a sample, the whole capillary was filled with a carrier ampholyte solution. An anode solution, an acid, was then introduced to fill only the IAC column segment. Focusing was started with a pressure that balances with the electroosmotic flow produced in the acidified IAC column. Fluorescence-labeled recombinant Fab with an E-tag spiked at 16 pM to 10 nM in 50% serum was separated and detected with high precision. The coupling principle allows rapid and high-resolution IEF analysis of a protein in a biological sample without any loss of the immunoaffinity captured protein.

A novel case of functional gastric neuroendocrine carcinoma occurred after endoscopic submucosal dissection.

In Japan, endoscopic submucosal dissection (ESD) is becoming a standard treatment for intramucosal differentiated gastric cancer. Although ESD is associated with a high cure rate for patients with early gastric cancer, tumors may recur, albeit rarely. We performed ESD on an 80-year-old man with a small depressed type of gastric cancer of the posterior wall of the cardia, found to be locally invasive on histology. Thirty months later, local recurrence and multiple liver metastases were detected, accompanied by frequent severe hypoglycemia. Despite chemotherapy, the patient died 6 months after relapse. On autopsy, the recurrent gastric lesion and liver metastases were examined immunohistochemically. Several characteristic tumor cells were positive for chromogranin A, cluster of differentiation (CD) 56, Ki-67, and insulin-like growth factor (IGF)-II. Western blot analysis of the patient's serum obtained during a hypoglycemic attack showed the high molecular weight form of IGF-II or "big" IGF-II. The patient was diagnosed with non-islet cell tumor hypoglycemia (NICTH), with "big" IGF-II being produced by the gastric neuroendocrine carcinoma. This is the novel case of a functional gastric neuroendocrine carcinoma that occurred after ESD and induced a hypoglycemic attack associated with NICTH.

Matrix effects in clinical immunoassays and the effect of preheating and cooling analytical samples.

Immunological reactions are influenced by various factors including antigens, antibodies and other variables. We focused on two items: i) matrix effects, especially of detergents and ii) temperature effects: preheating sera, especially effects on rheumatoid factor (RF) measurement and false-positive reactions in ELISAs, and cold storage of sera, especially effects on complement. Among various additives, detergents affected the agglutination reaction for fecal hemoglobin and hepatitis B surface (HBs) antigen. Some of the detergents examined abolished these antigenicities, however, polyethylenglycols enhanced the reactions. Heat-inactivation of sera at 56 degrees C for 30 min was employed in serological testing. However, in RF measurement, 10 min of preheating was sufficient to abolish C1q (subcomponent of C1), which could participate in the agglutination reaction. In ELISA for antibodies, false-positive reactions were caused by preheating sera. By the analyses of assays for antibodies to hepatitis C virus (HCV) and cardiolipin, it was found that they were induced by immunoglobulin G (IgG) modified by preheating. Cold storage induced activation of complement (cold activation) in anti-HCV antibody positive sera. CH50 titers in the sera were lowered by one cycle of freezing at -20 degrees C and thawing, and the decrease was affected by the containers.