Why is sex so rare in Lecane inermis (Rotifera: Monogononta) in wastewater treatment plants?

The monogonont rotifer Lecane inermis is commonly known as a facultative parthenogen. Unexpectedly, among numerous lineages we isolated from wastewater treatment plants (WWTP), only one was capable of sexual reproduction. We investigated why sex was so rare among L. inermis in WWTP. The reproductive modes of lineages derived from the sexual lineage were examined. Among all lineages, the fraction of those reproducing only asexually for 14 d was 0.39. In the subsequent round, the fraction of asexual lineages reached 0.61. The population growth rate of the parthenogenetic lineages was significantly higher than that of the sexual lineages. We simulated the fate of rotifer populations in WWTP by removing 10% of the experimental cultures each day. After 10 d of these conditions, the mean number of females was greater in parthenogenetic than in sexual lineages. After 20 d, only solitary dormant eggs remained in the sexual lineages. It therefore appears that the loss of sex may be attributed to the specific conditions of the WWTP. When there is no risk of desiccation and no need for dormancy, the fast‐growing parthenogens outcompete lineages investing in costly sex. Furthermore, even if some resting eggs were deposited, they would be washed out from the system with the excess sludge.     

Lipase‐catalyzed kinetic resolution of novel antitubercular benzoxazole derivatives

Novel benzoxazole derivatives were synthesized, and their antitubercular activity against sensitive and drug‐resistant Mycobacterium tuberculosis strains (M. tuberculosis H₃₇Rv, M. tuberculosis sp. 210, M. tuberculosis sp. 192, Mycobacterium scrofulaceum, Mycobacterium intracellulare, Mycobacterium fortuitum, Mycobacterium avium, and Mycobacterium kansasii) was evaluated. The chemical step included preparation of ketones, alcohols, and esters bearing benzoxazole moiety. All racemic mixtures of alcohols and esters were separated in Novozyme SP 435‐catalyzed transesterification and hydrolysis, respectively. The transesterification reactions were carried out in various organic solvents (tert‐butyl methyl ether, toluene, diethyl ether, and diisopropyl ether), and depending on the solvent, the enantioselectivity of the reactions ranged from 4 to >100. The enzymatic hydrolysis of esters was performed in 2 phase tert‐butyl methyl ether/phosphate buffer (pH = 7.2) system and provided also enantiomerically enriched products (ee 88‐99%). The antitubercular activity assay has shown that synthesized compounds exhibit an interesting antitubercular activity. Racemic mixtures of alcohols, (±)‐4‐(1,3‐benzoxazol‐2‐ylsulfanyl)butan‐2‐ol ((±)‐ 3a ), (±)‐4‐[(5‐bromo‐1,3‐benzoxazol‐2‐yl)sulfanyl]butan‐2‐ol ((±)‐ 3b ), and (±)‐4‐[(5,7‐dibromo‐1,3‐benzoxazol‐2‐yl)sulfanyl]butan‐2‐ol ((±)‐ 3c ), displayed as high activity against M. scrofulaceum, M. intracellulare, M. fortuitum, and M. kansasii as commercially available antituberculosis drug‐Isoniazid. Moreover, these compounds exhibited twice higher activity toward M. avium (MIC 12.5) compared with Isoniazid (MIC 50).     

The effect of genotype,media composition,pH and sugar concentrations on oat (<Emphasis Type="Italic">Avena sativa</Emphasis> L.) doubled haploid production through oat × maize crosses

Doubled haploid (DH) technology in oat has not reached the same stage as in other cereals leading to its application in plant breeding. The objective of this investigation was to increase the effectiveness of Avena sativa L. haploid embryo germination obtained by the distant crosses with maize. Developed embryos (obtained from 22 genotypes) were transferred on five germination media: MS (Murashige and Skoog, Physiol Plant 15:473–497, 1962) with 3% sucrose, pH 5.8 (control medium), and 190-2 supplemented with 6 and 9% maltose. The pH of 190-2 was adjusted to 5.5 and 6.0. Of all tested genotypes, 591 haploid embryos were obtained, almost half of them (279) germinated. The rate of haploid embryo germination induced on 190-2 was 6.92%, while in MS it was 3.25%. The sugar and its concentration significantly affected the germination of haploid embryos. The highest percentage of haploid embryo germination (9.11%) and DH lines production (1.64%) was achieved on 190-2 with 9% maltose and pH 6.0. All DH lines are incorporated to breeding programs for the development of new cultivars.     

Perfusion-CT - Can We Predict Acute Pancreatitis Outcome within the First 24 Hours from the Onset of Symptoms?

Purpose

Severe acute pancreatitis (AP) is still a significant clinical problem which is associated with a highly mortality. The aim of this study was the evaluation of prognostic value of CT regional perfusion measurement performed on the first day of onset of symptoms of AP, in assessing the risk of developing severe form of acute pancreatitis.

Material and Methods

79 patients with clinical symptoms and biochemical criteria indicative of acute pancreatitis (acute upper abdominal pain, elevated levels of serum amylase and lipase) underwent perfusion CT within 24 hours after onset of symptoms. The follow-up examinations were performed after 4–6 days to detect progression of the disease. Perfusion parameters were compared in 41 people who developed severe form of AP (pancreatic and/or peripancreatic tissue necrosis) with parameters in 38 consecutive patients in whom course of AP was mild. Blood flow, blood volume, mean transit time and permeability surface area product were calculated in the three anatomic pancreatic subdivisions (head, body and tail). At the same time the patient''s clinical status was assessed by APACHE II score and laboratory parameters such as CRP, serum lipase and amylase, AST, ALT, GGT, ALP and bilirubin were compared.

Results

Statistical differences in the perfusion parameters between the group of patients with mild and severe AP were shown. Blood flow, blood volume and mean transit time were significantly lower and permeability surface area product was significantly higher in patients who develop severe acute pancreatitis and presence of pancreatic and/or peripancreatic necrosis due to pancreatic ischemia. There were no statistically significant differences between the two groups in terms of evaluated on admission severity of pancreatitis assessed using APACHE II score and laboratory tests.

Conclusions

CT perfusion is a very useful indicator for prediction and selection patients in early stages of acute pancreatitis who are at risk of developing pancreatic and/or peripancreatic necrosis already on the first day of the onset of symptoms and can be used for treatment planning and monitoring of therapy of acute pancreatitis. Early suspicion of possible pancreatic necrosis both on the basis of scores based on clinical status and laboratory tests have low predictive value.     

Transfer of nodulation ability in Rhizobium using R68.45 derived plasmids

Summary Nodulation ability was transferred from Rhizobium meliloti L5.30 to the non-nodulating mutant Rhizobium trifolii 24K using plasmid R68.45. Transconjugants selected for the carbenicillin resistance (cb ^r) marker became simultaneously capable of nodulating clover and showed changes in phage sensitivity. Besides the indigenous plasmid of 90 MD (pUCS201), the nodulating transconjugants harbored the newly introduced plasmid pUCS202 (ca. 40 MD). After treatment of the transconjugants with curing agents the simultaneous loss of antibiotic resistance and ability to form nodules were associated with the disappearance of pUCS202. nod and cb ^r genes were cotransferred into R. trifolii strains by conjugation and transformation. There is genetic evidence that the nod gene(s) was integrated into R68.45.     

Antioxidant defense markers modulated by glutathione S-transferase genetic polymorphism: results of lung cancer case–control study

Oxidative stress and xenobiotic metabolizing enzymes are suspected to be related to carcinogenesis by different cellular mechanisms. Hence, our study aimed at identifying potential relationships between antioxidant defense parameters measured in blood and glutathione S-transferase (GST) genetic polymorphisms of four GST izoenzymes in lung cancer patients and reference individuals. The case-control study included 404 lung cancer patients and 410 non-cancer subjects as controls, matched by age, gender and place of living (central Poland). In control subjects with GSTM3*A/*A, GSTT1 null, GSTM1 null + GSTT1 null, GSTM3*A/*A + GSTT1 null genotype, glutathione peroxidase activity was significantly higher (P < 0.05) than in controls possessing respective potential protective GST genotypes. Controls with GSTM3*A/*A + GSTP1*B genotype presented significantly higher ceruloplasmin activity (P < 0.05) than GSTM3*B + GSTP1*A/*A carriers. Zinc level was significantly higher (P < 0.05) in controls and cases with GSTP1*B + GSTT1 null genotype and in cases with GSTM1 null + GSTP1*B genotype, when compared with respective potential protective GST genotypes. This case-control study indicates that particular defective GST genotypes may enhance the defense against oxidative stress. The potential relationship between the investigated antioxidative enzymes and microelements, and common functional genetic polymorphism of GST was observed mostly in control subjects.     

Microbial transformation of baicalin and baicalein

As a result of microbial transformation of baicalin and baicalein the products of 4′-hydroxylation of the B ring, O-methylation at C-6, and both O-methylation at C-6 and hydroxylation at C-4′ were obtained. Transformations of baicalin were accompanied by the reaction of hydrolysis.