Insulin-like growth factor (IGF)-I regulates IGF-binding protein-5 gene expression through the phosphatidylinositol 3-kinase, protein kinase B/Akt, and p70 S6 kinase signaling pathway

Expression of the insulin-like growth factor-binding protein 5 (IGFBP-5) gene in vascular smooth muscle cells is up-regulated by IGF-I through an IGF-I receptor-mediated mechanism. In this study, we studied the possible involvement of the mitogen-activated protein kinase (MAPK) and PI 3-kinase signaling pathways in mediating IGF-I-regulated IGFBP-5 gene expression. The addition of Des(1-3)IGF-I, an IGF analog with reduced affinity to IGFBPs, resulted in a transient activation of p44 and p42 MAPK. Inhibition of the MAPK activation by PD98059, however, did not affect IGF-I-stimulated IGFBP-5 expression. Des(1-3)IGF-I treatment also strongly activated PI 3-kinase. This activation was probably mediated through IRS-1, because IGF-I stimulation resulted in a significant increase in IRS-1- but not IRS-2-associated PI 3-kinase activity. This activation occurred within 5 min and was sustained at high levels for over 6 h. Likewise, Des(1-3)IGF-I caused a long lasting activation of PKB/Akt and p70(s6k). When LY294002 and wortmannin, two specific inhibitors of PI 3-kinase, were added with Des(1-3)IGF-I, the IGF-I-regulated IGFBP-5 expression was negated. The addition of rapamycin, which inhibits IGF-I-induced p70(s6k) activation, significantly inhibited IGF-I-regulated IGFBP-5 gene expression. These results suggest that the action of IGF-I on IGFBP-5 gene expression requires the activation of the PI 3-kinase-PKB/Akt-p70(s6k) pathway but not the MAPK pathway in vascular smooth muscle cells.     

Vasopressin Antagonist Disrupts the Circadian Rhythm of Water Intake on Suprachiasmatic Injection

The present study makes an attempt to find out the action of arginine vasopressin (AVP) and its antagonist d-(CH₂)₅Tyr (Me) AVP applied at the suprachiasmatic nuclei (SCN) on the circadian rhythm of water intake. Chronic implantation of a 22 G stainless steel cannula for injection was performed using a stereotaxic technique under Nembutal anesthesia. AVP and its antagonist were injected into the SCN of free-moving rats at the beginning of light and dark phases of the light-dark (LD) cycle. Injections of AVP during either phase did not disrupt the circadian pattern of water intake while the injections of the antagonist disrupted it. The findings are suggestive of the involvement of AVP as a mediator of the circadian rhythm of water intake at the level of the neural pacemaker, SCN.     

Isolation and characterization of a symbiotic cellulolytic mixed bacterial culture

Summary By using batch-culture enrichment techniques a mixed culture of two bacterial spe cies identified as Cellulomonas flavigena and Xanthomonas sp was isolated. The capacity of both bacteria to grow as pure cultures in a min eral medium with alkaline pretreated sugar cane bagasse or cellobiose was tested. C. flavigena as pure culture was able to grow on both substrates only when yeast extract or biotin and thiamine were added to the culture medium, while Xanthomonas sp. could not grow on sugar cane ba gasse, but assimilated cellobiose if yeast extract was supplied. However, both bacteria in mixed culture grew very well on both substrates and did not require any growth factor. It was concluded that the interaction was favourable to both species. The mixed culture had the capacity to degrade a number of different agricul tural wastes and to use them as the sole carbon and energy source for the production mainly of biomass. More than 80% of pineapple bagasse, without chemical pretreatment, was used up by the microbial system.     

Spontaneous Resolution and Super-coiling in Xerogels of the Products of Photo-Induced Formose Reaction

This work addresses the supramolecular self-organization in the xerogels of formose reaction products. The UV-induced formose reaction was held in over-saturated formaldehyde solutions at 70^°C without a catalyst. The solutions of the obtained carbohydrates were dried on a glass slide, and the obtained xerogels demonstrated a prominent optical activity, while the initial solutions were optically inactive. The xerogels contained highly elongated crystalline elements of a helical structure as well as the isometric ones. Thus xerogel formation was accompanied by a spontaneous resolution of enantiomers and separation of different-shaped supramolecular structures. The thick helices were twisted of thinner ones, while the latter were twisted of elementary structures having a diameter much smaller than 400 nm. Similar structural hierarchy is typical of biological macromolecules (DNA, proteins, and cellulose). Summarizing the obtained results, we proposed a hypothetical mechanism explaining the amplification of the initial enantiomeric excess, as well as chiral and chemical purification of the substances which were essential for the evolution of Life to start.

     

MEKK3 is required for endothelium function but is not essential for tumor growth and angiogenesis

Mitogen-activated protein kinase kinase kinase 3 (MEKK3) plays an essential role in embryonic angiogenesis, but its role in tumor growth and angiogenesis is unknown. In this study, we further investigated the role of MEKK3 in embryonic angiogenesis, tumor angiogenesis, and angiogenic factor production. We found that endothelial cells from Mekk3-deficient embryos showed defects in cell proliferation, apoptosis, and interactions with myocardium in the heart. We also found that MEKK3 is required for angiopoietin-1 (Ang1)-induced p38 and ERK5 activation. To study the role of MEKK3 in tumor growth and angiogenesis, we established both wild-type and Mekk3-deficient tumor-like embryonic stem cell lines and transplanted them subcutaneously into nude mice to assess their ability to grow and induce tumor angiogenesis. Mekk3-deficient tumors developed and grew similarly as control Mekk3 wild-type tumors and were also capable of inducing tumor angiogenesis. In addition, we found no differences in the production of VEGF in Mekk3-deficient tumors or embryos. Taken together, our results suggest that MEKK3 plays a critical role in Ang1/Tie2 signaling to control endothelial cell proliferation and survival and is required for endothelial cells to interact with the myocardium during early embryonic development. However, MEKK3 is not essential for tumor growth and angiogenesis. cardiovascular; mitogen-activated protein kinase; embryonic development     

Design and synthesis of phenethyl benzo[1,4]oxazine-3-ones as potent inhibitors of PI3Kinasegamma

The Type 1 PI3Kinases comprise a family of enzymes, which primarily phosphorylate PIP2 to give the second messenger PIP3, a key player in many intracellular signaling processes [Science, 2002, 296, 1655; Trends Pharmacol. Sci.2003, 24, 366]. Of the four type 1 PI3Ks, the gamma-isoform, which is expressed almost exclusively in leukocytes [Curr. Biol., 1997, 7, R470], is of particular interest with respect to its role in inflammatory diseases such as rheumatoid arthritis (RA) and chronic obstructive pulmonary disease (COPD) [Mol. Med. Today, 2000, 6, 347]. Investigation of a series of 4,6-disubstituted-4H-benzo[1,4]oxazin-3-ones has led to the identification of single-digit nanomolar inhibitors of PI3Kgamma, several of which had good cell based activity and were shown to be active in vivo in an aspectic peritonitis model of inflammatory cell migration.     

Characterization of antibodies for quantitative determination of spiggin protein levels in male and female three-spined stickleback (Gasterosteus aculeatus)

Spiggin is an adhesive glycoprotein produced in the kidney of sticklebacks during the breeding season and is subsequently secreted into the urinary bladder from where it is employed for nest building. Since the production of the protein has been shown to be under androgenic control, spiggin has been suggested to be a useful biomarker for androgenic substances in the environment. In this study, two polyclonal spiggin antibodies based on synthetic peptides and one polyclonal antibody directed against native spiggin have been characterized. The antibodies ability to identify spiggin was investigated by quantitative immunoassay. For both peptide antibodies the quantification range was determined to be between 1 and 80 ng spiggin and determination of renal spiggin levels from immature and mature males displayed a 15-fold increase in total spiggin content of the kidney resulting in a 6-fold increase in male kidney weight due to hypertrophy. The kidney somatic index (KSI) was found to correlate well with the total renal spiggin content and therefore it appears that KSI in sticklebacks could be used as an initial method to identify substances displaying androgenic effects. Furthermore, western blot analysis revealed that the polyclonal antibodies recognize different spiggin isoforms and that spiggin can be detected in the urinary bladder and kidney of both males and female sticklebacks. In order to develop a quantitative detection method for native spiggin it is necessary to produce a standard that can be used in a bioassay. Due to the adhesive and polymerization characteristics of spiggin the protein is difficult to use as a standard in bioassays. So far spiggin has been shown to exist in at least 14 isoforms, all of which contain polymerization domains. To overcome the solubility problem we have produced recombinant spiggin gamma, with only one polymerization domain, that can be expressed in E. coli. Western blot analysis demonstrated that the polyclonal antibodies were able to detect recombinant spiggin gamma protein in bacterial cell lysate, suggesting that it may be developed into a useful source of standard spiggin to be used for quantitative determination of androgen induced spiggin production in sticklebacks.     

“If You Are Not Circumcised,I Cannot Say Yes”: The Role of Women in Promoting the Uptake of Voluntary Medical Male Circumcision in Tanzania

Voluntary Medical Male Circumcision (VMMC) for HIV prevention in Tanzania was introduced by the Ministry of Health and Social Welfare in 2010 as part of the national HIV prevention strategy. A qualitative study was conducted prior to a cluster randomized trial which tested effective strategies to increase VMMC up take among men aged ≥20 years. During the formative qualitative study, we conducted in-depth interviews with circumcised males (n = 14), uncircumcised males (n = 16), and participatory group discussions (n = 20) with men and women aged 20–49 years in Njombe and Tabora regions of Tanzania. Participants reported that mothers and female partners have an important influence on men’s decisions to seek VMMC both directly by denying sex, and indirectly through discussion, advice and providing information on VMMC to uncircumcised partners and sons. Our findings suggest that in Tanzania and potentially other settings, an expanded role for women in VMMC communication strategies could increase adult male uptake of VMMC services.     

Standard and C-banded meiotic karyotypes of Psylloidea (Sternorrhyncha, Homoptera, Insecta).

Meiotic karyotypes were studied in males of Craspedolepta sonchi (Foerster, 1848), Diaphorina chobauti Puton, 1898, D. lamproptera Burckhardt, 1981, Psylla hartigii Flor, 1861, Cacopsylla palmeni (Loew, 1878), C. hippophaes (Foerster, 1848), C. melanoneura (Foerster, 1868), C. pyricola (Foerster 1848), C. moscovita (Andrianova, 1848), Bactericera salicivora (Reuter, 1876), Trioza abdominalis Flor, 1861, T. lauri = Lauritrioza alacris (Flor, 1861). Karyotypes were 2n = 25 (24 + XO) in all species except B. salicivora with 2n = 26 (24 + neo-XY). Testes consisted of two follicles each in all species but P. hartigii with four-follicular testes in males. The discussion covers the problems of chromosome numbers, sex-determining chromosome systems, B-chromosomes, patterns of C-banding, testis structure, and spermatid development in Psylloidea.     

Meiotic karyotypes in males of nineteen species of Psylloidea (Hemiptera) in the families Psyllidae and Triozidae

Meiotic karyotypes in males of 16 species (assigned to 9 genera and 7 subfamilies) ofthe family Psyllidae and 3 species (assigned to 3 genera of the subfamily Triozinae) of the family Triozidae are described for the first time. The first data on the genus Ligustrinia are presented. All the species were shown to exhibit the modal karyotype for psyllids, 2n = 24 + X, except Bactericera nigricornis and Arytainilla spartiophila, in which 2n = 24 + XY and 2n = 22 + X were found, respectively. The karyotype of Ctenarytaina eucalypti (Psyllidae, Spondyliaspidinae) was reinvestigated, and the karyotype 2n = 10 + X, characteristic of Spondyliaspidinae, was revealed. The karyotypes ofStrophingia fallax, S. arborea, and Craspedolepta topicalis were studied using the C-banding technique.