Morphogenetic lability of reproductive structures in Ruppia maritima (Ruppiaceae, Alismatales): from two lateral flowers to a terminal flower

Flowers of Ruppia are normally arranged into an open two-flowered spike, but sometimes the two lateral flowers are congenitally united with each other and form a terminal flower-like structure. This developmental abnormality resembles those described in well-investigated mutants of model organisms of developmental genetics such as Arabidopsis Antirrhinum. A study of Ruppia allows investigating morphogenetic lability of this feature in natural populations. These data will be important for understanding evolutionary transitions between open and closed inflorescences. This paper presents first data on frequencies ofterminal flower-like structures in natural populations of Ruppia maritima and first observations of their development. Vascular supply of inflorescences with free and united flowers is compared for the first time. Strong differences in frequencies of occurrence of terminal flower-like structures among examined natural populations are revealed. Data on variation of organ numbers in flowers of plants from different populations allow hypothesizing that increased size of floral primordia is a factor that plays a role in their amalgamation into ajoint primordium of a terminal structure. Vascular system of inflorescences of R. maritima with united flowers is quite similar to the vascular system of a flower and nothing contradicts a hypothesis on terminal position ofthis structure. Transversally inserted stamens in inflorescences with united flowers are usually of inverted polarity. This appears to be the first documented example of an inversion of relative polarity of stamens and carpels in angiosperms.     

Microbiological characteristics and sanitary status of Lake Peipsi-Pihkva and its inflows in 1980s

In 1980, 1982 and 1984–1987 the total count of bacteria (TC), the number of saprophytic bacteria (plate count, PC), total Coliforms and Enterococci were determined at 22 to 30 sampling sites in the pelagial of Lake Peipsi-Pihkva. Bacterioplankton production was investigated seasonally at two locations from May to November 1985–1987. Eleven inflows and the outflowing River Narva were studied three times in the vegetation period 1985–1987 and in winter 1987.The average TC was highest in L. Pihkva (4.3 × 10⁶ cells ml^–1), lower in L. Lämmijärv (3.9 × 10⁶ cells ml^–1) and the lowest in the northern part of L. Peipsi (2.2 × 10⁶ cells ml^–1). According to these data, L. Pihkva and L. Lämmijärv were similar to typical Estonian eutrophic lakes. L. Peipsi had mesotrophic features with a tendency to eutrophy in its southern part.The numbers of saprophytic bacteria (PC) in L. Pihkva and L. Lämmijärv fluctuated from 110 to 360 cells ml^–1, in L. Peipsi from 98 to 290 cells ml^–1, and up to 5400 and 5900 cells ml^–1 in the mouths of the Rivers Velikaja and Suur Emajõgi, respectively. The average production value per vegetation period was 37.9 g C m^–2.The numbers of Coliforms and Enterococci indicated that the pelagial was in a good sanitary state. Enterococci and high total Coliform numbers (up to 1000 per 100 ml) were determined at the mouths of the Rivers Suur Emajõgi and Velikaja.In comparison with the early 1960s, 1.5–2.0-fold increase in the total amount of bacteria in the 1980s was revealed in the southern more eutrophic regions of L. Peipsi-Pihkva where the fluctuation of parameters was greater.     

Arrayed primer extension on in situ synthesized 5'-->3' oligonucleotides in microchannels

Arrays of oligonucleotides synthesized in the 5'-->3' direction have potential benefit in several areas of life sciences research because the free 3'-end can be modified by enzymatic reactions. A Geniom One instrument (febit biomed GmbH, Germany), with integrated chip fabrication, multiplex primer extension, fluorescence imaging, and data analysis, was evaluated for studies of genomic variations. Microchannels used for the array synthesis in Geniom One were not optimized before for the APEX method and, as preliminary experiments demonstrated in this study, the signals were strongly affected by the speed of the process inside reaction channels. Using the two-compartment model (TCM), target binding to feature were quantitatively analyzed, revealing profound mass-transport limitations in the observed kinetics and enabling us to draw a series of physicochemical conclusions of the optimal set-up for the APEX reaction. Some kinetically relevant parameters such as target concentration, reaction time, and temperature were comprehensively analyzed. Finally, we applied the arrays and methods in a proof-of-principle experiment where 36 individuals were typed with 900 oligonucleotide probes (sense and antisense primers for 450 markers), using the ABCR gene as a test system. A new DNA analysis method for studies of genomic variation was developed using this all-in-one platform.     

Macrophage migration inhibitory factor in pediatric patients undergoing surgery for congenital heart repair

Macrophage migration inhibitory factor (MIF), a proinflammatory mediator, has been shown to be elevated following heart surgery in adults and may be associated with several postoperative complications, including cardiac and pulmonary dysfunction. In this study, we aimed to measure perioperative plasma MIF, interleukin (IL)-8, and free T4 in 20 children age <4 years undergoing surgical repair of congenital heart lesions with left ventricular volume overload, and to determine whether the response of these mediators determined postoperative outcomes. Plasma samples were obtained preoperatively, immediately on arrival in the pediatric intensive care unit (PICU), and at 12, 24, and 48 h. Patients were continuously monitored in the PICU, and data were recorded daily for therapeutic and monitoring procedures that reflected the invasiveness, intensity, and complexity of care rendered (therapeutic interventional scoring system, TISS). Preoperative plasma MIF, IL-8, and free T4 were not different from age-matched healthy children. However, plasma MIF and IL-8 increased significantly 2 h after completion of cardiopulmonary bypass, and then normalized within 24 h. Peak postoperative levels of MIF (48 +/- 24 ng/mL) and IL-8 (79 +/- 57 pg/mL) correlated significantly with duration of cardiopulmonary bypass. The magnitude of the postoperative increase in plasma MIF was associated with increased number of days required for mechanical ventilation (r = 0.553; P = 0.012), and peak plasma IL-8 correlated significantly with the fraction of inhaled oxygen (FiO(2)) required immediately after surgery (r = 0.510; P = 0.02). Higher circulating MIF levels correlated significantly with increased inotropic support requirements on the second postoperative day, whereas higher postoperative IL-8 levels were associated with higher TISS scores, suggesting increased need for postoperative medical care. These data suggest a potential negative effect of high circulating levels of MIF in the immediate postoperative period on respiratory and cardiovascular functions, and support the development of therapeutic strategies targeting MIF function in this clinical setting.