Insulin hypersensitivity in mice lacking the V1b vasopressin receptor

We have reported that [Arg⁸]-vasopressin-stimulated insulin release is blunted in islet cells isolated from V1b receptor-deficient ( V1bR ^−/−) mice. In this study, we used V1bR ^−/− mice to examine the physiological role of the V1b receptor in regulating blood glucose levels in vivo , and we found that the fasting plasma glucose, insulin and glucagon levels were lower in V1bR ^−/− mice than in wild-type ( V1bR ^+/+) mice. Next, we evaluated glucose tolerance by performing an intraperitoneal glucose tolerance test (GTT). The plasma glucose and insulin levels during the GTT were lower in V1bR ^−/− mice than in V1bR ^+/+ mice. An insulin tolerance test (ITT) revealed that, after insulin administration, plasma glucose levels were lower in V1bR ^−/− mice than in V1bR ^+/+ mice. In addition, a hyperinsulinaemic–euglycaemic clamp study showed that the glucose infusion rate was increased in V1bR ^−/− mice, indicating that insulin sensitivity was enhanced at the in vivo level in V1bR ^−/− mice. Furthermore, we found that the V1b receptor was expressed in white adipose tissue and that insulin-stimulated phosphorylation of Akt as an important signaling molecule was increased in adipocytes isolated from V1bR ^−/− mice. Thus, the blockade of the V1b receptor could result, at least in part, in enhanced insulin sensitivity by altering insulin signalling in adipocytes.     

Rapid detection of Epstein-Barr virus DNA by loop-mediated isothermal amplification method.

BACKGROUND: The loop-mediated isothermal amplification (LAMP) method is a novel technique for the amplification of specific DNA sequences. OBJECTIVES: To establish the LAMP method for amplifying Epstein-Barr virus (EBV) DNA and to examine its reliability for the detection of EBV DNA in clinical specimens. STUDY DESIGN: Sera from 108 patients, who were initially suspected of primary EBV infection, were tested by the EBV LAMP method, and the results were compared with those of the real-time PCR assay. Serological examination was regarded as the standard diagnostic method. RESULTS: To diagnose primary EBV infection, the sensitivity of LAMP was 86.4% and the specificity was 100%. The sensitivity of the real-time PCR assay was 84.1% and the specificity was 98.4%. Longitudinal analysis showed that the detection rate of EBV DNA in serum by the LAMP method decreased with time in accordance with the decrease of the EBV load. EBV DNA could not be detected in serum 40 days after onset of symptoms. CONCLUSIONS: These results indicate that the sensitivity and specificity of the LAMP method are comparable to those of real-time PCR and that detecting EBV DNA in serum by this method is potentially useful for diagnosing primary EBV infection.     

Selective loss of gastrointestinal mast cells and impaired immunity in PI3K-deficient mice

Mice that lack the p85alpha regulatory subunit of phosphatidylinositol-3 kinase (PI3K) are deficient in gastrointestinal and peritoneal mast cells but have dermal mast cells. Accordingly, these mice show impaired bacterial clearance in response to acute septic peritonitis and are highly susceptible to infection by the intestinal nematode Strongyloides venezuelensis. Systemic anaphylactic shock responses, however, are intact. We found that although reconstitution of PI3Kminus sign/minus sign mice with bone marrow--derived mast cells (BMMCs) restored anti-bacterial immunity, only T helper type 2 (TH2)-conditioned BMMCs, not "standard" BMMCs, were able to restore anti-nematode immunity. This finding highlights the importance of the TH2 response in the control of nematode infection. Thus, PI3K likely plays an essential role in host immune responses by regulating both the development and induction of mast cells.     

Synthesis and properties of thermotropic liquid-crystalline polymers containing transition metals

New thermotropic, liquid-crystalline polyesters ( 5a, b, 6a, b ) with mesogenic bipyridinediyl units were synthesized. They form complexes with Fe(II) and Cu(II) salts. Homopolyesters 5a, b , containing no metal or less than a certain amount of metal, are smectic. A nematic mesophase was observed in the case of copolyester 6a, b . The structural properties of a polyester complex 5a with Cu, as crystal, liquid-crystal and isotropic liquid, were examined by ESR.     

Clear cell adenocarcinoma with endobronchial polypoid growth

Clear cell adenocarcinoma of the lung is extremely rare. On radiography, a 45-year-old female with fever was found to have an abnormal shadow in the left lower lung field. Bronchoscopy revealed a polypoid tumor in the left bronchus. On biopsy, the tumor was determined to be adenocarcinoma. Preoperative examination found no tumors outside of the lung. The patient underwent left lower lobectomy with bronchial wedge resection. The tumor had completely obstructed and dilated the left lower bronchus, but had not invaded the tissue outside the bronchial wall. Microscopically, the cytoplasm of the tumor cells contained abundant glycogen, and the tumor had solid and glandular structures. The tumor was diagnosed as clear cell adenocarcinoma of the lung.     

Projection of the retinal ganglion cells to the tectum differentiated from the prosencephalon.

The alar plate of the prosencephalon differentiates into a tectum-like structure when transplanted into the mesencephalon around the 10-somite stage. Here, we report on the projection pattern of the retinal ganglion cells to the transplants. Optic nerve fibers were labeled with horseradish peroxidase (HRP) and 3H-proline, and the innervation of the optic nerve fibers to the chimeric tectum was analyzed by HRP histochemistry on whole-mounted specimens, by autoradiography and by electron microscopy on embryonic day 16. In the chimeric tectum, the transplant was distinguished from the host by difference in nuclear structure between the quail and the chick cells. It was shown that the transplant had the laminar pattern of the optic tectum when the transplant was integrated into the host mesencephalon. The whole-mount HRP histochemistry showed that the optic nerve fibers extend to the transplants. Autoradiography showed that the distribution pattern of silver grains was similar in both the host and the transplant. These results may indicate that the optic nerve fibers turn to the transplant and terminate on the transplant. Electron microscopy further confirmed that optic nerve fibers ended by making synaptic contacts with the dendrites in the transplant region of the tectum. These results indicate that the transplant with the laminar pattern of the optic tectum is a true tectum receiving input from the eye.     

A calorimetric study of the interaction of synthetic phospholipid liposomes with lipid-soluble small molecules used as dental materials and devices

The interaction of 22 lipid-soluble small molecules, widely used in dental materials and devices, with synthetic phospholipid liposomes, was investigated by the application of differential scanning calorimetry (DSC), in order to clarify the mechanism of small molecules in biological systems. Dimyristoyl phosphatidyl choline (DMPC) and dipalmitoyl phosphatidyl choline (DPPC) were used as lipids. The interaction of various monomers with liposomes has been reported by us in this journal. In this experiment, various compounds such as redox-initiator, photo-initiator or photo-sensitizer, inhibitor, root-canal disinfectant, cement-base materials (eugenol and 2-ethoxybenzoic acid) etc., were investigated. From changes in the phase transition temperature (T), enthalpy (delta H kcal mol-1) and H/HHW values of both DMPC and DPPC liposomes induced by these molecules, it was concluded that aromatic tertiary amine, benzoyl peroxide and hydroquinone monomethyl ether had a relatively large effect on liposomes, and that in phenol derivatives, m-cresol and p-chlorophenol had a large effect on liposomes compared to phenol. Eugenol used as dental cement also had a large effect on liposomes due to its high hydrophobicity. Changes in the transition properties of liposomes induced by small molecules (characterized by shift of T to a lower temperature, an increase or decrease in cooperativity (H/HHW), and a decrease in delta H of a endothermic peak) seemed to be related to biological activities.     

Purification and characterization of gene 17 product of bacteriophage T3

Tail fiber proteins of bacteriophage T3 are encoded by gene 17. By using in vitro complementation for phage assembly as an assay, the product of gene 17 (gp17) was purified to near homogeneity from cells infected with a double mutant of T3 defective in DNA synthesis and head assembly. The purified gp17 consists of a single polypeptide having a molecular weight of 67,000. Electron microscopy of the purified gp17 showed a fiber structure similar to the tail fiber in a virion. The subunit structure of the purified, native gp17 was analyzed by using a crosslinking agent, dimethyl suberimidate. The results indicate that native gp17 is a trimer of gp17 monomer.