Relaxin-3 and RXFP3 expression, and steroidogenic actions in the ovary of teleost fish

Relaxins are peptides similar in secondary structure to insulins. In teleost genomes, five or six relaxin genes have been identified. Two relaxins group closely with mammalian relaxin-3 on phylogenetic analysis and are named relaxin-3a and b. We refer to the remainder as relaxins c to f. Ovarian expression of relaxin-3a, d and f genes, and the relaxin-3 receptor gene Rxfp3, was studied in Danio rerio using RT-PCR. Immunohistochemistry was used to determine the distribution of relaxin-3 peptides and RXFP3 in the ovary of Fundulus heteroclitus (killifish). Thirdly, enzyme immunoassays and ovarian follicular culture were used to determine the effect of treatment with human recombinant relaxin-3 on the production of 17beta-estradiol and 17 alpha, 20 beta-dihydroxy-4-pregnen-3-one in killifish ovarian follicles. Relaxin-3a, d, f, and Rxfp3 genes were expressed regardless of sex or reproductive condition. Relaxin-3 immunostaining was present in mid to late follicular stages within cortical alveoli of the oocyte cytopasm, whereas receptor staining was localized to follicular cells. Treatment with relaxin-3 enhanced 17beta-estradiol production in early and late maturing follicles, but did not have an effect in vitellogenic follicles. Relaxin-3 appeared to suppress the release of MIS production. This suggests that relaxin peptides may be involved with estradiol-dependant events in follicular development.     

Biosynthesis of chiral 3-hydroxyvalerate from single propionate-unrelated carbon sources in metabolically engineered <Emphasis Type="Italic">E. coli</Emphasis>

Background  

The ability to synthesize chiral building block molecules with high optical purity is of considerable importance to the fine chemical and pharmaceutical industries. Production of one such compound, 3-hydroxyvalerate (3HV), has previously been studied with respect to the in vivo or in vitro enzymatic depolymerization of biologically-derived co-polymers of poly(3-hydroxybutyrate-co-3-hydroxyvalerate). However, production of this biopolymeric precursor typically necessitates the supplementation of a secondary carbon source (e.g., propionate) into the culture medium. In addition, previous approaches for producing 3HV have not focused on its enantiopure synthesis, and thus suffer from increased costs for product purification.     

Electron microscopic map of divisions 61, 62, and 63 of the salivary gland 3L chromosome in Drosophila melanogaster

The banding pattern in the three distal divisions of the salivary gland 3L chromosome of Drosophila melanogaster was analysed with electron microscopy (EM). New maps for divisions 61, 62, and 63 were drawn on the basis of electron micrographs taken from thin-sectioned squash preparations. Observations showed 41 regularly and 16 occasionally detectable new bands in these three divisions. On the other hand, only 9 of 24 Bridges' doublets also appeared as double bands on the EM maps. Accordingly, the total number of bands is more than 25% higher in the EM maps of divisions 61–63 than in Bridges' revised map of 3L. At least 13 sites of puffing activity can be localized in the electron micrographs of divisions 61–63.Dedicated to Prof. Dr. Hans Bauer on the occasion of his 80th birthday on September 27, 1984     

Preservation of fresh edible cactus stems (<i>Opuntia ficus indica</i> Mill.) by modified atmosphere packaging

Cactus stems, the cladodes of Opuntia spp. cacti, are consumed in Mexico and other countries due to their fresh and herbaceous flavor, and because of their widely known nutraceutical benefits. In order to extend the postharvest life of this vegetable, the effect of a modified atmosphere packaging (MAP) was studied in cactus stems of the cultivar Atlixco stored at 4 ± 1 °C for 20 days under three types of atmospheres: (1) air (passive atmosphere), (2) 5 kPa O₂ + 4 kPa CO₂, and (3) N₂. During storage, the titratable acidity decreased and the color of cladodes became darker and less green; however, the 5 kPa O₂ + 4 kPa CO₂ atmosphere was able to preserve both quality characteristics. All modified atmospheres reduced weight loss (from 8 to <2%) and the symptoms of chilling injury, and this physiological disorder appeared earlier in controls than in MAP-stored cladodes. The levels of fermentation metabolites were low in all three evaluated atmospheres. Because of this, only cladodes stored under the N₂ atmosphere were selected for furthersensory analysis of the MAP effect on odor perception as evaluated by a trained panel. Results indicated that there was no detrimental effect (atypical odors) of MAP on this sensory characteristic. We conclude that cultivar Atlixco is suitable for preservation using MAP technology.     

Visualization of elusive structures using intracardiac echocardiography: Insights from electrophysiology

Echocardiography has the ability to noninvasively explore hemodynamic variables during pharmacologic or exercise stress test in patients with heart failure. In this review, we detail some important potential applications of stress echocardiography in patients with heart failure. In patients with coronary artery disease and chronic LV dysfunction, dobutamine stress echocardiography is able to distinguish between viable and fibrotic tissue to make adequate clinical decisions. Exercise testing, in combination with echocardiographic monitoring, is a method of obtaining accurate information in the assessment of functional capacity and prognosis. Functional mitral regurgitation is a common finding in patients with dilated and ischaemic cardiomyopathy and stress echocardiography in the form of exercise or pharmacologic protocols can be useful to evaluate the behaviour of mitral regurgitation. It is clinical useful to search the presence of contractile reserve in non ischemic dilated cardiomyopathy such as to screen or monitor the presence of latent myocardial dysfunction in patients who had exposure to cardiotoxic agents. Moreover, in patients with suspected diastolic heart failure and normal systolic function, exercise echocardiography could be able to demonstrate the existence of such dysfunction and determine that it is sufficient to limit exercise tolerance. Finally, in the aortic stenosis dobutamine echocardiography can distinguish severe from non-severe stenosis in patients with low transvalvular gradients and depressed left ventricular function.     

The role of transforming growth factor-beta on retarded osteoblastic differentiation in vitro

Various matrix growth factors play important roles in the development and growth of cartilage and bone. Among them transforming growth factor-beta superfamily and especially bone morphogenetic proteins are known to be important factors, since they induce bone and cartilage formation in ectopic sites in vivo. We have previously shown that the human osteosarcoma cell line Saos-2 expresses molecules that in vivo induce new bone formation with asymmetric bone maturation. In this study we examined the role of Saos-2-conditioned medium in prolonged cultures of mesenchymal C3H/10T1/2 cells. The C3H/10T1/2 cells were cultured with Saos-2-conditioned medium for 28 days. We show that Saos-2-treated C3H/10T1/2 cells performed retarded osteoblastic differentiation when compared to recombinant BMP-2 and -4 induced differentiation. We further show that this retardation is due to excessive amounts of transforming growth factor-beta in Saos-2-conditioned medium. Our results also suggest that this model can well be used to study additional cofactors involved in retarded osteogenesis.     

The polytene dot chromosome of <Emphasis Type="Italic">Drosophila</Emphasis>: <Emphasis Type="Italic">D. melanogaster</Emphasis> and <Emphasis Type="Italic">D. subobscura</Emphasis>

The chromosome arms are assumed to be homologous within the genus Drosophila. Homology at the level of the polytene chromosome banding pattern between non-sibling species is, however, almost impossible to establish as different processes such as inversion, transposition and unequal crossing over, have disturbed it. Even though the band sequences cannot be followed, we may ask whether there is a correlation in the total number of bands between species. The polytene dot chromosome is an excellent starting point for such an approach. Here we present the detailed cytology of polytene chromosome 4 of D. melanogasterand the polytene dot chromosome of D. subobscura using electron microscopy. The results show that the number of bands is about the same, around 30, in both species. We predict that by using thin sections and electron microscopy for the longer polytene chromosome arms, both species will turn out to have approximately equal band numbers.     

Tumor-associated trypsinogen-2 (trypsinogen-2) activates procollagenases (MMP-1, -8, -13) and stromelysin-1 (MMP-3) and degrades type I collagen

A critical step in cancer growth and metastasis is the dissolution of the extracellular matrix surrounding the malignant tumor, which leads to tumor cell invasion and dissemination. Type I collagen degradation involves the initial action of collagenolytic matrix metalloproteinases (MMP-1, -8, and -13) activated by MMP-3 (stromelysin-1). The role of interactive matrix serine proteinases (MSPs), including tumor-associated trypsinogens, has been unclear in collagenolysis. Now, we provide evidence that the major isoenzyme of human tumor-associated trypsinogens, trypsin-2, can directly activate three collagenolytic proMMPs as well as proMMP-3. These proMMP activations are inhibited by tumor-associated trypsin inhibitor (TATI). Furthermore, we demonstrate that trypsin-2 efficiently degrades native soluble type I collagen, which can be inhibited by TATI. However, cell culture studies showed that trypsin-2 transfection into the HSC-3 cell line did not result in MMP-1, -3, -8, and -13 activation but affected MMP-3 and -8 production at the protein level. These findings indicate that human trypsin-2 can be regarded as a potent tumor-associated matrix serine protease capable of being the initial activator of the collagenolytic MMP activation network as well as directly attacking type I collagen.