Potential changes with gamma-band oscillation at the frontal scalp elicited by intravenous olfactory stimulation in humans

Intravenous olfaction is a unique stimulation method often used in Japan to diagnose olfactory disturbances. Odorant is injected into a vein and transported by blood flow and respiration to the upper air tract. The intravenous olfaction might allow the potential at the frontal scalp to be recorded without contamination from electromyograms, such as those caused by sniffing. We injected Alinamin (thiamine propyldisulphide) into healthy subjects according to a standard protocol for clinical intravenous olfaction testing and we simultaneously recorded potential changes at the frontal scalp. When Alinamin was injected into the right median cubital vein over a 20 s period, the potential changes with gamma-band oscillations were detected 17.6 +/- 6.7 s (mean +/- SD) after the start of the injection. The main frequency component of this gamma-band oscillation is 30-160 Hz. The gamma-band oscillation elicited by intravenous olfactory stimulation (VOP) was similar to the induced wave of the olfactory bulb. Mapping the VOPs on the frontal scalp of a subject with less developed frontal sinuses and the relation between the thickness of the frontal sinuses and VOP amplitude suggest an intracranial source, possibly the olfactory bulb. The gamma-band potential at the frontal scalp is a useful measure of central disturbance.     

Antibacterial effect of Kampo herbal formulation Hochu-ekki-to (Bu-Zhong-Yi-Qi-Tang) on Helicobacter pylori infection in mice

Because Helicobacter pylori (H. pylori) infection is a major cause of gastroduodenal diseases in humans, the eradication of H. pylori using antibiotics is very effective for the treatment of gastroduodenal diseases. However, it has recently been reported that resistance to these antibiotics is developing. In the present study, the antibacterial effect of a Kampo (traditional Japanese medicine) herbal formulation, Hochu-ekki-to (RET; Formula repletionis animalis et supletionis medii), against H. pylori was examined in vitro and in vivo. HET inhibited the growth of antibiotic-resistant strains of H. pylori as well as antibiotic-sensitive strains at a dose of 2.5 mg/ml in vitro. When 1,000 mg/kg of HET was administered orally to C57BL/6 mice for 7 days before or after inoculation with H. pylori, H. pylori in the stomach was significantly reduced in the HET-pre-treatment group compared with the control group. Furthermore, HET in combination with antibiotics completely eradicated the bacteria in mice. The expression of interferon (IFN)-gamma was induced in the gastric mucosa of the mice pre-treated with HET. There were no significant differences between the colonization of H. pylori in the control and HET treatment groups in IFN-gamma gene-deficient mice. These results suggest that the antibacterial effect of HET may be partly due to IFN-gamma induction, and that HET may be clinically useful for treatment of H. pylori infection.     

Distinct N-terminal regulatory domains of Ca(2+)/H(+) antiporters

The regulation of intracellular Ca(2+) levels is achieved in part by high-capacity vacuolar Ca(2+)/H(+) antiporters. An N-terminal regulatory region (NRR) on the Arabidopsis Ca(2+)/H(+) antiporter CAX1 (cation exchanger 1) has been shown previously to regulate Ca(2+) transport by a mechanism of N-terminal auto-inhibition. Here, we examine the regulation of other CAX transporters, both within Arabidopsis and from another plant, mung bean (Vigna radiata), to ascertain if this mechanism is commonly used among Ca(2+)/H(+) antiporters. Biochemical analysis of mung bean VCAX1 expressed in yeast (Saccharomyces cerevisiae) showed that N-terminal truncated VCAX1 had approximately 70% greater antiport activity compared with full-length VCAX1. A synthetic peptide corresponding to the NRR of CAX1, which can strongly inhibit Ca(2+) transport by CAX1, could not dramatically inhibit Ca(2+) transport by truncated VCAX1. The N terminus of Arabidopsis CAX3 was also shown to contain an NRR. Additions of either the CAX3 or VCAX1 regulatory regions to the N terminus of an N-terminal truncated CAX1 failed to inhibit CAX1 activity. When fused to N-terminal truncated CAX1, both the CAX3 and VCAX1 regulatory regions could only auto-inhibit CAX1 after mutagenesis of specific amino acids within this NRR region. These findings demonstrate that N-terminal regulation is present in other plant CAX transporters, and suggest distinct regulatory features among these transporters.     

Differential expression of tissue factor and tissue factor pathway inhibitor in metastatic melanoma lesions

Tissue factor (TF) is involved in tumor progression and metastatic potency in some malignant tumors and its function is regulated by tissue factor pathway inhibitor (TFPI) therefore the interaction of both molecules is crucial for their functional role. We evaluated the clinical relevance of TF and TFPI expression in benign and malignant melanocytic lesions. Expression of both was examined by immunoperoxidase staining using serial tissue sections in 16 nevi, 34 primary and 15 metastatic melanoma lesions. TF and TFPI were ubiquitously expressed in benign and malignant melanocytic lesions. This finding was confirmed by Western blot analysis using cultured human melanocytes, nevi cells (NCN) and melanoma cell lines. Although TF expression was not associated with malignant transformation and disease progression, TFPI expression in primary and metastatic melanoma lesions was significantly lower and weaker than that in nevi lesions in terms of intensity and percentage of stained cells. In addition, TFPI expression in metastatic lesions was significantly lower and weaker than that of TF. These results suggest that the relative expression of TF to TFPI may play a crucial role in the malignant transformation and metastatic potency in melanocytic cells.     

Luteolin,a flavone,does not suppress postprandial glucose absorption through an inhibition of alpha-glucosidase action

In order to clarify the postprandial glucose suppression via alpha-glucosidase (AGH) inhibitory action by natural compounds, flavonoids were examined in this study. Among the flavonoids (luteolin, kaempferol, chrysin, and galangin), luteolin showed the potent maltase inhibitory activity with the IC50 of 2.3 mM, while less inhibitions were observed against sucrase. In addition, the effects of maltase inhibition by flavonoids were observed in the descending order of potency of luteolin > kaempferol > chrysin > galangin. Apparently, the AGH inhibition power greatly increased with the replacement of hydroxyl groups at 3' and 4'-position of the B-ring. However, the inhibitory power of luteolin was poorer than a therapeutic drug (acarbose: IC50; 430 nM). As a result of a single oral administration of maltose or sucrose (2 g/kg) in SD rats, no significant change in blood glucose level with the doses of 100 and 200 mg/kg of luteolin was observed. These findings strongly suggested that luteolin given at less than 200 mg/kg did not possess the ability to suppress the glucose production from carbohydrates through the inhibition of AGH action in the gut.     

Removal of mucus for ultrastructural observation of the surface of human gastric epithelium using pronase

Background. Helicobacter pylori adhering to the human gastric epithelium causes gastric diseases such as ulcer, carcinoma and lymphoma. It is thus important to observe in detail both the surface of the epithelial cells and the H. pylori that adhered to it for the elucidation of H. pylori‐induced diseases by scanning electron microscopy (SEM). Since the thick mucus layer blocks the observation of the cell surface and the bacteria, it is generally eliminated during the processing for SEM by roughly mechanical methods, but these treatments also demolish the ultrastructure of the cells. We studied the nonmechanical method for removal of mucus layer of gastric epithelium using pronase. Materials and Methods. To determine the optimal concentration of pronase, mucin was used as a substrate for inhibition of the viscosity. Pronase was added in 2% mucin at the concentration of 10, 50, 100, 500, 1000, 2000 or 5000 unit/ml and the flowing time of the mixture was measured. Based on the digestion experiment, biopsied specimens from 24 patients with dyspepsic symptoms were fixed in glutaraldehyde and then washed in rolling with different concentration of pronase. After the pretreatment by pronase, the specimens were treated according to the standard process for SEM. Results. We succeeded in removing the mucus layer on the surface of epithelial cells from the biopsied specimens fixed in glutaraldehyde by rinsing with 2000 unit/ml pronase for 24 hours. Conclusions. Using our digestive method without destroying the ultrastructure, the earliest stage which H. pylori has adhered onto the human gastric epithelium can be observed for the investigation of H. pylori‐induced gastric disorders by SEM.     

Differential recognition of tyrosine-based basolateral signals by AP-1B subunit mu1B in polarized epithelial cells

To investigate the importance of tyrosine recognition by the AP-1B clathrin adaptor subunit mu1B for basolateral sorting of integral membrane proteins in polarized epithelial cells, we have produced and characterized a mutant form of mu1B. The mutant (M-mu1B) contains alanine substitutions of each of the four conserved residues, which in the AP-2 adaptor subunit micro2 are critical for interacting with tyrosine-based endocytosis signals. We show M-mu1B is defective for tyrosine binding in vitro, but is nevertheless incorporated into AP-1 complexes in transfected cells. Using LLC-PK1 cells expressing either wild type or M-mu1B, we find that there is inefficient basolateral expression of membrane proteins whose basolateral targeting signals share critical tyrosines with signals for endocytosis. In contrast, membrane proteins whose basolateral targeting signals are distinct from their endocytosis signals (transferrin and low-density lipoprotein receptors) accumulate at the basolateral domain normally, although in a manner that is strictly dependent on mu1B or M-mu1B expression. Our results suggest that mu1B interacts with different classes of basolateral targeting signals in distinct ways.     

cDNA cloning and characterization of Drb1, a new member of RRM-type neural RNA-binding protein

Neural RNA recognition motif (RRM)-type RNA-binding proteins play essential roles in neural development. To search for a new member of neural RRM-type RNA-binding protein, we screened rat cerebral expression library with polyclonal antibody against consensus RRM sequences. We have cloned and characterized a rat cDNA that belongs to RRM-type RNA-binding protein family, which we designate as drb1. Orthologs of drb1 exist in human and mouse. The predicted amino acid sequence reveals an open reading frame of 476 residues with a corresponding molecular mass of 53kDa and consists of four RNA-binding domains. drb1 gene is specifically expressed in fetal (E12, E16) rat brain and gradually reduced during development. In situ hybridization demonstrated neuron-specific signals in fetal rat brain. RNA-binding assay indicated that human Drb1 protein possesses binding preference on poly(C)RNA. These results indicate that Drb1 is a new member of neural RNA-binding proteins, which expresses under spatiotemporal control.