Structure and serological studies of the O-polysaccharide of Proteus penneri 75 Epitopes and subgroups of Proteus serogroup O73

The O-specific polysaccharide of the lipopolysaccharide of Proteus penneri strain 75 consists of tetrasaccharide-ribitol phosphate repeating units and resembles ribitol teichoic acids of Gram-positive bacteria. The following structure of the polysaccharide was elucidated by chemical methods and 1H and 13C NMR spectroscopy: [structure in text] where Rib-ol is ribitol. Serological studies with polyclonal antisera showed that the same structure of the O-polysaccharide occurred in two strains: P. penneri 75 and 128. A similar structure has been established earlier for the O-polysaccharide of P. penneri 103 [Drzewiecka, D., et al., Carbohydr. Res. 337 (2002) 1535-1540]. On the basis of complex serological investigations with use of two polyclonal P. penneri 75 and 103 O-antisera, five strains could be classified into Proteus O73 serogroup: P. penneri 48, 75, 90, 103 and 128, two of which (P. penneri 75 and 128) should be subdivided into subgroup 73a, 73b and three others (P. penneri 48, 90 and 103) into subgroup 73a, 73c. Epitopes responsible for the cross-reactivity of P. penneri O73 strains and a related strain of P. mirabilis O20 were tentatively defined.     

Type 1 diabetes as a mask of a neuroendocrine tumour of pancreas

Neuroendocrine tumours of pancreas originating from pancreatic islet cells are uncommon neoplasms with clinical manifestation depending on a type of hormone secreted. Diabetes as a clinical sign of such a tumour has been reported many times and is not an uncommon finding but it is generally mild and makes only a part ofa whole pattern of symptoms. We report on a case of a malignant neuroendocrine pancreatic tumour in 19 years old patient, where diabetes, with a clinical course typical for type 1 diabetes, was the first and the main symptom of the disease.     

Anti-inflammatory and opioid-mediated effects of melatonin on experimental peritonitis in chickens

The immunomodulatory properties of melatonin (Mel) are generally recognized but the mechanisms of its action are not fully understood. In mammals, some of the immunomodulatory effects of Mel are mediated by opioids synthesized by immune cells under its influence. The present study was performed to examine whether Mel-induced opioids are involved in the immunomodulatory activity of Mel in chickens. Experimental peritonitis was evoked by a single ip injection of thioglycollate (TG), and half of the birds were pre-treated with Mel. Some of the Mel-treated birds were additionally pre-treated with naltrexone, an antagonist of opioid receptors. Control birds received an injection of saline, Mel or were untreated. At specific post-injection intervals chickens were sacrificed, the peritoneal cavity was flushed out and peritoneal leukocytes (PTLs) were counted. The activity of PTLs was measured in vitro by the level of reactive oxygen species (ROS). Splenocytes were isolated aseptically and mitogen-stimulated in vitro proliferation was assessed. In PTLs and splenocytes the expression of opioid (proopiomelanocortin and proenkephalin) genes was also examined. Mel exerted a bi-phasic effect on TG-induced peritonitis in chickens: initially it blocked the development of peritonitis, decreasing the number of PTLs and intracellular ROS level (anti-inflammatory action), and thereafter an increase in both PTL number and ROS level was observed (pro-inflammatory action). The pro-inflammatory effect occurred a few hours after the induction of expression of the proenkephalin gene in PTLs and both the proenkephalin and proopiomelanocortin genes in splenocytes. These effects were prevented by naltrexone, suggesting involvement of the opiatergic mechanism.     

Bovine mu-calpain (CAPN1) gene: new SNP within intron 14

The calpain system originally comprised molecules: two Ca2+-dependent proteases, mu-calpain and m-calpain, and a third polypeptide, calpastatin, whose only known function is to inhibit the two calpains. This proteolytic system plays a key role in the tenderisation process that occurs during post-mortem storage of meat under refrigerated conditioning. Their polymorphism is examined from the point of view of their effect on corresponding production traits. The calpain genes are investigated as potential candidate genes for a quantitative trait locus (QTL) affecting meat tenderness. In this study a new single nucleotide polymorphism (SNP) was found within intron 14 of the bovine CAPN1 gene, being transition C --> T at position 4685 nt (consensus sequence - GenBank No. AF 248054), as this mutation creates a new FokI restriction site detected with PCR-RFLP analysis. This sequence fragment of the SNP position has already been deposited in the GenBank database under accession No. AY639597. The RFLP-FokI polymorphism was studied in 141 bulls of seven breeds, including the native Polish Red (PR, preserved), and Polish Black-and White (BW) breed. The frequency of alleles T and C varied between the breeds considered, the mean reaching 0.38 and 0.62, respectively. Associations between CAPN1/FokI gene polymorphism and meat production traits were studied in BW (n = 84) young bulls. In the animals of the TT genotype the lean share in valuable cuts (%) was found more favourable than in CC animals.     

PKC and Raf-1 inhibition-related apoptotic signalling in N2a cells

In this study, a neuroblastoma N2a cell line was applied to investigate mechanisms of apoptosis induced either by selective inhibition of protein kinase C (PKC) by low amounts of staurosporine (STS(10) ) or by inhibition PI3-K after wortmannin (WM) treatment. We present evidence that, in the absence of serum in the medium, decreased phosphorylation of Raf-1 and BAD112, as well as Akt and BAD136, proteins and their translocation to mitochondria coincided with STS10 - or WM-induced apoptosis, respectively. Concomitantly, release of cytochrome c into the cytosol indicated a BCL-2-dependent mode of cell death after both treatments. Furthermore, in typical 'gain of function' experiments, cells with overexpression of permanently active Raf-1 or Akt transgenes displayed a significantly higher and independent resistance to either STS10 or WM. Thus, our results indicate that PKC/Raf-1/BAD112, as well as PI3-K/Akt/BAD136 signalling pathways, are both necessary for N2a cell survival and thus are unable to functionally substitute for each other as long as the cells do not receive additional signal(s) derived from serum. However, in the presence of serum, undefined trophic signal(s) can stimulate cross-talk between these two pathways at a level upstream from Raf-1 and Akt phosphorylation. In this case, only simultaneous inhibition of PKC and PI3-K is able to induce apoptosis.     

Comparison of physical and chemical characters of tomato fruits grown from plants received from seeds or obtained in vitro

Results of experiments concerning comparison of tomato fruit properties which were collected from plants obtained in three manners are described. Control plants were received from seeds. Remaining plants were derived in vitro from leaf and shoot fragments on MS medium supplemented with IAA 0.2 mg·l⁻¹ and BA 2 mg·l⁻¹ (Górecka and Krzyżanowska 1991, Górecka et al. 1994) or with Fari’s et al. (1992) method of obtaining plants by decapitation of sterile seedlings and culture on MS medium without hormones. Evaluation of physical and chemical fruit characters was performed. In the spring experiment the biggest diameter (72 mm), weight (154 g) and volumne (151 ml) were characterized to fruits from plants obtained in vitro on MS medium with IAA and BA. Also fruits from plants received by Fari’s methods were significantly superior in these characters over fruits from the control plants. The fruits from the plants obtained in vitro on MS medium with IAA and BA had highest sugar content (2.95 % f.wt.) and fruits from in vitro plants after Fari’s method contained highest vit.C-13.4 mg·100 g⁻¹ f.wt (significant differences in comparison to control fruits). In other characters fruits from in vitro did not differ as compared to control ones. In the autumn experiments significant differences among fruit groups and characters evaluated were not stated. Generally, yield quality was poorer in the all autumn treatments.     

Effect of sugars,amino acids,and culture technique on maturation of somatic embryos of Pinus strobus on medium with two gellan gum concentrations

Maturation of five embryogenic lines of Pinus strobus L. was tested on media with various sugars and sources of organic nitrogen, and solidified with two gellan gum concentrations (0.6 and 1.0%). Mature somatic embryo production was more abundant at 1.0% gellan gum than at 0.6%. Complex combinations of amino acids had little effect on mature embryo production of most tested embryogenic lines. Increasing glutamine concentration of the maturation medium from 1.7 to 7.3 g l⁻¹ was beneficial to one embryogenic line. Increasing sucrose concentration or substituting part of the sucrose with mannitol or sorbitol had variable effects on somatic embryo maturation depending on the embryogenic line. A medium with 88 mM sucrose plus 175 mM sorbitol solidified with 1.0% gellan gum produced high numbers of somatic embryos in four out of five embryogenic lines tested. This revised version was published online in June 2006 with corrections to the Cover Date.     

Sensitivity of apple seed germination to light and some growth regulators

Experiments were aimed at checking whether the non-stratified apple embryos are sensitive to growth factors and light. The effect of growth regulators on light sensitivity was also studied. The stimulating or inhibiting effect of GA3, benzyladenine and IAA or coumarin on the dynamics of apple embryo germination was demonstrated. Seasonal fluctuations of the effect of the growth factors were noted. The stimulating effect of light on the germination of non-stratified apple embryos was demonstrated. This effect is independent of season and seems to be independent of the effects of growth regulators.     

Strukturen endopolyploider Kerne im Bereich der Samenanlage einiger Monocotylen

Zusammenfassung Die Kerne der Antipoden vonHyacinthus orientalis (Kulturformen) undCrocus suaveolens wachsen endomitotisch heran und werden bei der erstgenannten Art schätzungsweise bis zu 32ploid, bei der anderen bis zu 64ploid.In diploiden sowie hypertriploiden Pflanzen vonHyacinthus sind zwei Strukturtypen der endopolyploiden Kerne vorhanden, und zwar solche mit gleichmäßiger Struktur und andere mit lockeren Bündeln von Endochromosomen. Im Nukleolus der Antipoden diploider Pflanzen tritt ein einziges wurstförmiges Endochromozentrum hervor; in den 1 oder 2 Nukleolen der hypertriploiden Pflanzen sind 2 solche Endochromozentren vorhanden.Die Kerne der endopolyploiden Antipoden vonCrocus suaveolens zeigen in einer euchromatischen Grundstruktur langgestreckte Endochromozentren, von denen eines in Verbindung mit dem Nukleolus steht. An diesem Nukleolus-assoziierten Endochromozentrum finden sich in manchen Kernen unmittelbar neben dem Hauptnukleolus zusätzliche kleine Nukleolen in verschiedener Zahl.Im Basalapparat des Endosperms vonAllium ursinum wurden in Kernen verschiedener Polyploidiegrade neben den bereits angegebenen Strukturen vereinzelt Riesenchromosomen beobachtet. Sie zeigen den charakteristischen Chromomerenbau.BeiNothoscordum fragrans geht das Kern Wachstum in den Synergiden, in den Antipoden und im Basalapparat des Endosperms endomitotisch vor sich. Die Biesenkerne des Endosperms zeigen Bündel von Endochromosomen mit Restspiralen.

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Summary The nuclei in the antipodals ofHyacinthus orientalis (cultivated forms) andCrocus suaveolens increase by endomitotic polyploidization; their highest degree of endopolyploidy is approximately 32 n inHyacinthus and 64 n inCrocus.In diploid as well as in hypertriploid plants ofHyacinthus two structural types of endopolyploid nuclei occur, viz. nuclei with equally distributed chromatin and others with loose strands obviously consisting of several to many endochromosomes. Within the nucleolus of the antipodals of diploid plants a single oblong chromocentre occurs, while in the 1 or 2 nucleoli of hypertriploids two such endochromocentres are regularly encountered.InCrocus suaveolens the nuclei of the endopolyploid antipodals show several oblong chromocentres together with the uniform euchromatic structure; one of them is connected with the nucleolus. In some nuclei this SAT-endochromocentre produces in close vicinity of the big main nucleolus additional small nucleoli in various number.As previously described, the basal apparatus of the endosperm ofAllium ursinum contains nuclei of various degrees of endopolyploidy; besides other well-known structures they show sporadically giant chromosomes with the characteristic chromomeric constitution.InNothoscordum fragrans the nuclei of the synergids, as well as those of the antipodals and the basal apparatus of the endosperm enlarge by endomitotic polyploidization. The giant nuclei of the endosperm show complex strands of endochromosomes with relic spirals.