Escherichia coli lacking the AcrAB multidrug efflux pump also lacks nonproteinaceous,PHB-polyphosphate Ca2+ channels in the membrane

PHB(polyP) complexes bind calcium and form calcium channels in the cytoplasmic membrane in Escherichia coli and are likely to be important in Ca(2+) homeostasis in this organism. E. coli N43, which lacks the AcrA component of a major multidrug resistance pump, was shown to be defective in calcium handling, with an inability to maintain submicromolar levels of free Ca(2+) in the cytoplasm. Therefore, using an N-phenyl-1-napthylamine (NPN)-dependent fluorescence assay, we measured temperature-dependent phase transitions in the membranes of intact cells. These transitions specifically depend on the presence of PHB(Ca(2+)polyP) complexes. PHB(Ca(2+)polyP) channel complexes, particularly in stationary phase cultures, were detected in wild-type strains; however, in contrast, isogenic acrA(-) strains had greatly reduced amounts of the complexes. This indicates that the AcrAB transporter may have a novel, hitherto undetected physiological role, either directly in the membrane assembly of the PHB complexes or the transport of a component of the membrane, which is essential for assembly of the complexes into the membrane. In other experiments, we showed that the particular defective calcium handling detected in N43 was not due to the absence of AcrA but to other unknown factors in this strain.     

Reproductive features of <Emphasis Type="Italic">Upeneus margarethae</Emphasis> (Mullidae), a species recorded in the coastal zone of Vietnam for the first time

The species Upeneus margarethae described recently from the western Indian Ocean is recorded in the coastal zone of Vietnam for the first time. The reproductive features of the representatives of the species from southern Central Vietnam (Nha Trang Bay), Central Vietnam (Da Nang), and North Vietnam (Ha Long Bay) are studied. Based on the analysis of maturity stages of female’s ovaries and gonadosomatic index, the fishes spawn over the entire year in Central Vietnam, but the spawning interruption is observed in North Vietnam during a winter season. In Nha Trang Bay, 50% of females reach sexual maturity at the body length (FL) 9.8 cm. Based on histological structure of ovaries and frequency distribution of oocyte diameter before the spawning, the oogenesis is continuous. Anomalous oocyte structure is registered in 20% of the females. Egg morphology is described for 3 h after activation of ovulated oocytes. A comparison of reproductive parameters in U. margarethae and U. tragula is conducted.     

A synthetic approach to novel carvotacetone and antheminone analogues with anti-tumour activity

A synthetic approach to analogues of the terpenoid natural product antheminone A is described which employs (?)-quinic acid as starting material. A key conjugate addition step proved to be unpredictable regarding its stereochemical outcome however the route allowed access to two diastereoisomeric series of compounds. The results of biological assay of the toxicity of the target compounds towards non-small-cell lung cancer cell line A549 are reported.     

Physiological roles of the angiogenic factors during posthatching development period and adults in the quail lung

The bronchus and vasculature form an intrinsic functional component of the avian lung, and its growth must be tightly regulated and coordinated by lung epithelial and endothelial development. Vascular endothelial growth inhibitor (VEGI), vascular endothelial growth factor (VEGF) and its receptors (flk1/KDR, flt1/fms, flt4) are required for epithelial and endothelial cell survival and apoptosis. Especially, VEGF and its receptors are critical for the development of the lung and serve as a maintenance factor during adult life. To determine the function of VEGI, VEGF and its receptors in the posthatching lung development, we revealed its expression and localization using by immunohistochemical procedure. VEGI, VEGF and its receptors were observed in the structural components of the bronchi, atria and air capillaries, as well as in the pulmonary blood vessels throughout the posthatching development period. On the other hand, immunostaining for VEGI, VEGF and its receptors was faintly detected in the glands of the secondary bronchi. Furthermore, it was determined that the secondary bronchial and atrial muscles did not display VEGF immunoreactions. Our results showed that VEGF and its receptors (flt1/fms, flk1/KDR and flt4) and VEGI were expressed at varying intensity by different cell groups. Therefore, they are also required for the development of the lung component during posthatching period.     

Evaluation of Antifungal Susceptibility Testing with Microdilution and Etest Methods of <Emphasis Type="Italic">Candida</Emphasis> Blood Isolates

Candida species that show an increasing number of clinical and/or microbiological resistance to several antifungals and are the most common agents of invasive fungal infections. The aim of this study was to investigate the in vitro susceptibility of Candida blood isolates to antifungal agents (amphotericin B, fluconazole, itraconazole, and voriconazole) by comparative use of the CLSI reference microdilution method and Etest. Four hundred Candida blood isolates (215 Candida albicans, 185 non-albicans Candida strains) were included in the study. The broth microdilution test was performed according to the CLSI M27 A2 document. Etest was carried out according to the manufacturer’s instructions. The MIC results obtained with reference microdilution were compared with those obtained with the Etest by using percent and categorical agreements. According to MIK₉₀ values, voriconazole was the most active and itraconazole was the least active drug in vitro against all Candida species. Other than voriconazole, statistically significant differences were found when the susceptibility of Candida albicans and non-albicans Candida spp. to amphotericin B, fluconazole, and itraconazole were compared. These antifungal agents were found to be more active to C. albicans. Among the non-albicans Candida species, the lowest MIC values were obtained for Candida parapsilosis isolates. When the standard method was compared with Etest, the total agreement was higher for C. albicans than for non-albicans species, especially for fluconazole and voriconazole. In view of the findings, it was concluded that itraconazole showed the lowest activity against all Candida species. Etest could be an alternative method in assessing the in vitro antifungal susceptibility of Candida spp., but it is more convenient to use the microdilution method for studying in vitro susceptibility of non-albicans species, in particular for those possessing high MIC values against azoles.     

Rapid and high quality DNA isolation from Origanum onites for RAPD and ISSR analysis

Origanum onites is an economically important medicinal plant with high essential oil content. Lack of an appropriate DNA isolation procedure is a limiting factor for any molecular study of this plant. We have used a protocol for genomic DNA isolation based on a hexadecyltrimethylammonium bromide (CTAB) method described for other plant species. The method involves mortar grinding of leaf tissue, modified CTAB extraction using high salt concentrations and polyvinyl pyrrolidone, and successive isoamyl alcohol/chloroform extractions. The yield was approx. 20 microg DNA per 200 mg of initial fresh plant material. The genomic DNA obtained by this method was suitable to be used in restriction digests, inter simple sequence repeat (ISSR) and randomly amplified polymorphic DNA (RAPD) reactions. This extraction method should facilitate the molecular analysis of Origanum chemotypes.     

Zinc deficiency as a critical problem in wheat production in Central Anatolia

In a soil and plant survey, and in field and greenhouse experiments the nutritional status of wheat plants was evaluated for Zn, Fe, Mn and Cu in Central Anatolia, a semi-arid region and the major wheat growing area of Turkey.All 76 soils sampled in Central Anatolia were highly alkaline with an average pH of 7. 9. More than 90% of soils contained less than 0.5 mg kg^-1 DTPA-extractable Zn, which is widely considered to be the critical deficiency concentration of Zn for plants grown on calcareous soils. About 25% of soils contained less than 2.5 mg kg^-1 DTPA-extractable Fe which is considered to be the critical deficiency concentration of Fe for plants. The concentrations of DTPA-extractable Mn and Cu were in the sufficiency range. Also the Zn concentrations in leaves were very low. More than 80% of the 136 leaf samples contained less than 10 mg Zn kg^–1. By contrast, concentrations of Fe, Mn and Cu in leaves were in the sufficient range.In the field experiments at six locations, application of 23 kg Zn ha^-1 increased grain yield in all locations. Relative increases in grain yield resulting from Zn application ranged between 5% to 554% with a mean of 43%. Significant increases in grain yield (more than 31%) as a result of Zn application were found for the locations where soils contained less than 0.15 mg kg^-1 DTPA-extractable Zn.In pot experirnents with two bread (Triticum aestivum, cvs. Gerek-79 and Kirac-66) and two durum wheats (Triticum durum, cvs. Kiziltan-91 and Kunduru-1149), an application of 10 mg Zn kg^-1 soil enhanced shoot dry matter production by about 3.5-fold in soils containing 0.11 mg kg^-1 and 0.15 mg kg^-1 DTPA-extractable Zn. Results from both field observations and greenhouse experiments showed that durum wheats were more susceptible to Zn deficiency than the bread wheats. On Zn deficient soils, durum wheats as compared to bread wheats developed deficiency symptoms in shoots earlier and to a greater extent, and had lower Zn concentration in shoot tissue and lower Zn content per shoot than the bread wheats.The results presented in this paper demonstrate that (i) Zn deficiency is a critical nutritional problem in Central Anatolia substantially limiting wheat production, (ii) durum wheats possess higher sensitivity to Zn deficient conditions than bread wheats, and (iii) wheat plants grown in calcareous soils containing less than 0.2 mg kg^-1 DTPA-extractable Zn significantly respond to soil Zn applications. The results also indicate that low levels of Zn in soils and plant materials (i.e. grains) could be a major contributing factor for widespread occurrence of Zn deficiency in children in Turkey, whose diets are dominated by cereal-based foods.     

Sperm motility in three coral reef fish species

A method of computer assisted sperm analysis (CASA) is used to determine the parameters of sperm motility in three fish species from the coral reefs of the Nha Trang Bay, South China Sea, Vietnam: Zebrasoma scopas (Acanthuridae), Abudefduf sexfasciatus, and Dascyllus trimaculatus (Pomacentridae). The representatives of the families are characterized by different reproductive tactics and possess pelagic and demersal eggs, respectively. The main morphological parameters of spermatozoa have been measured. The average curvilinear velocity of spermatozoa movement along the real trajectory (VCL) after 1 min of sperm activation ranges from 15.3 to 74.5 μm/s in Z. scopas, it is comparatively low (12.7–21.6 μm/s) in A. sexfasciatus, and high (58.4–92.2 μm/s) in D. trimaculatus. The duration of progressive movements in more than 50% of spermatozoa at 25°C is 3–20, 5–11, and 6–9 min after sperm activation, respectively. Following storage of the sperm of three species at 4.5°C for 7, 20, and 28 h, respectively, spermatozoa retain the ability of progressive movements. The results are discussed based on the available information on the activity of sperm in fish.     

Chromosome 11 rearrangements in various hematological neoplasias

Chromosome 11 abnormalities in leukemic bone marrow cells were observed in 14.0% of the cases of acute lymphoblastic leukemia (ALL), in 18.7% of acute myeloid leukemia (AML) cases, and in 16.7% of refractory anemia (RA) cases. Bands 11pl3, 11pl4, 11pl5 on the short arm and 11ql4, 11q21, 11q23 on the long arm of chromosome 11 were involved in these rearrangements. Rearrangements of band 11q23 were detected most often. Reciprocal translocations were found with the highest frequency, while para-and pericentic inversions and deletions, both terminal and interstitial, occurred less often. In RA cases only deletions were observed. Comparison of clinical features showed no correlation with age and major hematological indexes such as the number of blast cells in the initial period. These results show that the prognosis is poor in cases of abnormalities at both 11q21 and 11q23 in acute leukemia (AL) as well as in 11pl3 and 11pl5 in AML. This is the first observation of these phenomena.