Further evidence that central neurotensin inhibits pituitary prolactin secretion by stimulating dopamine release from the hypothalamus

Intracerebroventricular (icv) injection of neurotensin (NT) (2 micrograms/rat) suppressed prolactin (PRL) release induced by L-5-hydroxytryptophan (1 mg/100 g body wt, iv), prostaglandin E2(1 microgram/rat, icv), and FK33-824 (10 micrograms/100 g body wt, iv), a Met5-enkephalin analog, in urethane-anesthetized or conscious rats. In contrast, NT did not suppress elevated plasma PRL levels sustained by a large dose of domperidone (10 micrograms/100 g body wt, iv), a peripheral dopamine antagonist. In in vitro experiments, NT (10(-5) M) stimulated dopamine release from perifused rat hypothalamic fragments. These results suggest that central NT inhibits PRL secretion by stimulating dopamine release from the hypothalamus into hypophysical portal blood in the rat.     

Synthesis of complex-type glycans derived from parasitic helminths

Chemical synthesis of complex-type glycans 1 and 2 derived from eggs of parasitic helminths, Schistosoma mansoni and Schistosoma japonicum, is described. These branched sugar chains were synthesized regio- and stereoselectively by using beta-mannosylation, desilylation under high pressure, and glycosylation in frozen solvent as key transformations.     

Effect of Osmotic Stress on Turgor Pressure in Mung Bean Root Cells

Turgor pressure in cells of the elongating region of intactmung bean roots was directly measured by using the pressure-probetechnique. After the external osmotic pressure had been increasedfrom 0 MPa to 0.5 MPa, turgor pressure rapidly decreased byabout 0.5 MPa from 0.65 MPa to 0.14 MPa and root elongationstopped. Subsequent turgor regulation was clearly confirmed,which followed the osmotic adjustment to maintain a constantdifference in the osmotic pressure between root-cell sap andthe external medium ( II). It took at least 6 h for turgor pressureto recover to an adjusted constant level of about 0.5 MPa dueto turgor regulation, but rootelongation resumed within onlyan hour after the osmotic treatment. Therefore, the resumptionof root elongation under osmotic stress could not have beendirectly connected with turgor regulation. Furthermore, sincethe amounts of decrease in turgor pressure just after applicationsof various degrees of osmotic stress could be interpreted inrelation to those in II, hydraulic conductivity between theinside and the outside of root cells must be large enough toattain water potential equilibrium rapidly in response to osmoticstress. We conclude that turgor pressure in the cells of theelongating region of mung bean roots is determined mainly by II because of water potential equilibrium. (Received January 27, 1987; Accepted May 21, 1987)     

On the constancy of the evolutionary rate of cistrons

Summary The variations of evolutionary rates in hemoglobins and cytochrome c among various lines of vertebrates are analysed by estimating the variance. The observed variances appear to be larger than expected purely by chance.If the amino acid substitutions in evolution are the result of random fixation of selectively neutral or nearly neutral mutations, the evolutionary rate of cistrons can be represented by the integral of the product of mutation rate and fixation probability in terms of selective values around the neutral point. This integral is called the effective neutral mutation rate.The influence of effective population number and generation time on the effective neutral mutation rate is discussed. It is concluded that the uniformity of the rate of amino acid substitutions over diverse lines is compatible with random fixation of neutral or very slightly deleterious mutations which have some chance of being selected against during the course of substitution. On the other hand, definitely advantageous mutations will introduce significant variation in the substitution rate among lines. Approximately 10% of the amino acid substitutions of average cistrons might be adaptive and create slight but significant variations in evolutionary rate among vertebrate lines, although the uniformity of evolutionary rate is still valid as a first approximation.Contribution No. 813 from the National Institute of Genetics, Mishima, Shizuokaken 411 Japan. Aided in part by a grant-in-aid from the Ministry of Education, Japan.     

A novel DNA polymerase inhibitor and a potent apoptosis inducer: 2-mono-O-acyl-3-O-(alpha-D-sulfoquinovosyl)-glyceride with stearic acid

Sulfo-glycolipids in the class of sulfoquinovosyl diacylglycerol (SQDG) including the stereoisomers are potent inhibitors of DNA polymerase alpha and beta. However, since the alpha-configuration of SQDG with two stearic acids (alpha-SQDG-C(18)) can hardly penetrate cells, it has no cytotoxic effect. We tried and succeeded in making a permeable form, sulfoquinovosyl monoacylglycerol with a stearic acid (alpha-SQMG-C(18)) from alpha-SQDG-C(18) by hydrolysis with a pancreatic lipase. alpha-SQMG-C(18) inhibited DNA polymerase activity and was found to be a potent inhibitor of the growth of NUGC-3 cancer cells. alpha-SQMG-C(18) arrested the cell cycle at the G1 phase, and subsequently induced severe apoptosis. The arrest was correlated with an increased expression of p53 and cyclin E, indicating that alpha-SQMG-C(18) induced cell death through a p53-dependent apoptotic pathway.     

Relationships between Micro-Vascular and Iodine-Staining Patterns in the Vicinity of the Tumor Front of Superficial Esophageal Squamous Carcinoma

Objective

The aim of the present study was to clarify differences between micro-vascular and iodine-staining patterns in the vicinity of the tumor fronts of superficial esophageal squamous cell carcinomas (ESCCs).

Methods

Ten consecutive patients with ESCCs who were treated by endoscopic submucosal dissection (ESD) were enrolled. At the edge of the iodine-unstained area, we observed 183 sites in total using image-enhanced magnifying endoscopy. We classified the micro-vascular and iodine-staining patterns into three types: Type A, in which the line of vascular change matched the border of the iodine-unstained area; Type B, in which the border of the iodine-unstained area extended beyond the line of vascular change; Type C, in which the line of vascular change extended beyond the border of the iodine-unstained area. Then, by examining histopathological sections, we compared the diameter of intra-papillary capillary loops (IPCLs) in cancerous areas and normal squamous epithelium.

Results

We investigated 160 sites that the adequate quality of pictures were obtained. There was no case in which the line of vascular change completely matched the whole circumference of the border of an iodine-unstained area. Among the 160 sites, type A was recognized at 76 sites (47.5%), type B at 79 sites (49.4%), and type C at 5 sites (3.1%). Histological examination showed that the mean diameter of the IPCLs in normal squamous epithelium was 16.2±3.7μm, whereas that of IPCLs in cancerous lesions was 21.0±4.4μm.

Conclusions

The development of iodine-unstained areas tends to precede any changes in the vascularity of the esophageal surface epithelium.     

Characterization of Cep135, a novel coiled-coil centrosomal protein involved in microtubule organization in mammalian cells.

By using monoclonal antibodies raised against isolated clam centrosomes, we have identified a novel 135-kD centrosomal protein (Cep135), present in a wide range of organisms. Cep135 is located at the centrosome throughout the cell cycle, and localization is independent of the microtubule network. It distributes throughout the centrosomal area in association with the electron-dense material surrounding centrioles. Sequence analysis of cDNA isolated from CHO cells predicted a protein of 1,145-amino acid residues with extensive alpha-helical domains. Expression of a series of deletion constructs revealed the presence of three independent centrosome-targeting domains. Overexpression of Cep135 resulted in the accumulation of unique whorl-like particles in both the centrosome and the cytoplasm. Although their size, shape, and number varied according to the level of protein expression, these whorls were composed of parallel dense lines arranged in a 6-nm space. Altered levels of Cep135 by protein overexpression and/or suppression of endogenous Cep135 by RNA interference caused disorganization of interphase and mitotic spindle microtubules. Thus, Cep135 may play an important role in the centrosomal function of organizing microtubules in mammalian cells.     

Assessment of border control measures and community containment measures used in Japan during the early stages of Pandemic (H1N1) 2009

Background

In the early stages of Pandemic (H1N1) 2009, border control measures were taken by quarantine stations to block the entry of infected individuals into Japan and community containment measures were implemented to prevent the spreading. The objectives of this study were to describe these measures and the characteristics of infected individuals, and to assess the measures'' effectiveness.

Methodology/Principal Findings

Border control and community containment measures implemented from April to June (Period I: April 28–May 21, Period II: May 22–June 18) 2009 were described. Number of individuals identified and disease characteristics were analyzed. For entry screening, a health declaration form and an infrared thermoscanner were used to detect symptomatic passengers. Passengers indicated for the rapid influenza test underwent the test followed by RT-PCR. Patients positive for H1N1 were isolated, and close contacts were quarantined. Entry cards were handed out to all asymptomatic passengers informing them about how to contact a health center in case they developed symptoms. Nine individuals were identified by entry screening and 1 during quarantine to have Pandemic (H1N1) 2009. Health monitoring by health centers was performed in period I for passengers arriving from affected countries and in period II for those who had come into contact with the individuals identified by entry screening. Health monitoring identified 3 infected individuals among 129,546 in Period I and 5 among 746 in Period II. Enhanced surveillance, which included mandatory reporting of details of the infected individuals, identified 812 individuals, 141 (18%) of whom had a history of international travel. Twenty-four of these 141 passengers picked up by enhanced surveillance had been developing symptoms on entry and were missed at screening.

Conclusion/Significance

Symptomatic passengers were detected by the various entry screening measures put in place. Enhanced surveillance provided data for the improvement of public health measures in future pandemics.     

Analysis of substrate specificity and cyclin Y binding of PCTAIRE-1 kinase

PCTAIRE-1 (cyclin-dependent kinase [CDK] 16) is a highly conserved serine/threonine kinase that belongs to the CDK family of protein kinases. Little is known regarding PCTAIRE-1 regulation and function and no robust assay exists to assess PCTAIRE-1 activity mainly due to a lack of information regarding its preferred consensus motif and the lack of bona fide substrates. We used positional scanning peptide library technology and identified the substrate-specificity requirements of PCTAIRE-1 and subsequently elaborated a peptide substrate termed PCTAIRE-tide. Recombinant PCTAIRE-1 displayed vastly improved enzyme kinetics on PCTAIRE-tide compared to a widely used generic CDK substrate peptide. PCTAIRE-tide also greatly improved detection of endogenous PCTAIRE-1 activity. Similar to other CDKs, PCTAIRE-1 requires a proline residue immediately C-terminal to the phosphoacceptor site (+1) for optimal activity. PCTAIRE-1 has a unique preference for a basic residue at +4, but not at +3 position (a key characteristic for CDKs). We also demonstrate that PCTAIRE-1 binds to a novel cyclin family member, cyclin Y, which increased PCTAIRE-1 activity towards PCTAIRE-tide >100-fold. We hypothesised that cyclin Y binds and activates PCTAIRE-1 in a way similar to which cyclin A2 binds and activates CDK2. Point mutants of cyclin Y predicted to disrupt PCTAIRE-1-cyclin Y binding severely prevented complex formation and activation of PCTAIRE-1. We have identified PCTAIRE-tide as a powerful tool to study the regulation of PCTAIRE-1. Our understanding of the molecular interaction between PCTAIRE-1 and cyclin Y further facilitates future investigation of the functions of PCTAIRE-1 kinase.