Weed problems in various tillage systems in the Nordic countries

There is an increasing use of various forms of reduced tillage or no-tillage in the Nordic countries. This will favour the growth of grass weed species and perennial species. Perennial creeping weeds like Elymus repens, Cirsium arvense, and Sonchus arvensis are important in all Nordic countries. Stationary weeds such as Taraxacum spp., Artemisia vulgaris and volunteer grassland species increase in areas with reduced tillage and especially no-tillage systems. Winter annual and biennial species such as Matricaria perforata, Poa annua, Alopecurus geniculatus and Stellaria media are frequently occuring weeds in reduced tillage systems in all countries, while Alopecurus myosuroides and Apera spica-venti are problems in Denmark and Southern parts of Sweden and Finland

Chemoenzymatic Synthesis of Cryptophycin Anticancer Agents by an Ester Bond-Forming Non-ribosomal Peptide Synthetase Module

Cryptophycins (Crp) are a group of cyanobacterial depsipeptides with activity against drug-resistant tumors. Although they have been shown to be promising, further efforts are required to return these highly potent compounds to the clinic through a new generation of analogues with improved medicinal properties. Herein, we report a chemosynthetic route relying on themultifunctional enzyme CrpD-M2 that incorporates a 2-hydroxy acid moiety (unit D) into Crp analogues. CrpD-M2 is a unique nonribosomal peptide synthetase (NRPS) module comprised of condensation-adenylation-ketoreduction-thiolation (C-A-KR-T) domains. We interrogated A-domain 2-keto and 2-hydroxy acid activation and loading, and KR domain activity in the presence of NADPH and NADH. The resulting 2-hydroxy acid was elongated with three synthetic Crp chain elongation intermediate analogues through ester bond formation catalyzed by CrpD-M2 C domain. Finally, the enzyme-bound seco-Crp products were macrolactonized by the Crp thioesterase. Analysis of these sequential steps was enabled through LC-FTICR-MS of enzyme-bound intermediates and products. This novel chemoenzymatic synthesis of Crp involves four sequential catalytic steps leading to the incorporation of a 2-hydroxy acid moiety in the final chain elongation intermediate. The presented work constitutes the first example where a NRPS-embedded KR domain is employed for assembly of a fully elaborated natural product, and serves as a proof-of-principle for chemoenzymatic synthesis of new Crp analogues

Response of the Esophageal Epithelium to Concomitant Cis-Dichlorodiammineplatinum(II) and Radiation Treatment. An Electron Microscopic Study in Rabbits

The rabbit esophageal mucosa was irradiated with daily fractions of 2 Gy up to an accumulated dose of 20 Gy (total dose 2, 6, 10. 16 or 20 Gy). Fifteen to forty-five minutes before the start of each irradiation 0.3 mg Cis-dichlorodiammineplatinum (cis-DDP, cisplatinum) was given by intraperitoneal injection to each rabbit. Examinations were carried out 1-10 days after each fractionation schedule, when specimens were taken for morphological investigations. Scanning electron microscope (SEM) examination showed a gradual development of damage with cell loss and structural disarrangement of the microridges and whorls on the surface. However, with further treatment the esophageal mucosa exposed to cis-DDP and radiation normalized faster and more complete compared to the esophageal part exposed to cis-DDP alone. The difference may depend on an accelerated proliferation in the part of the trachea that is exposed to a combined treatment

The Response of the Tracheal Epithelium to Concomitant Cis-Diamminedichloroplatinum (II) and Radiation. An Electron Microscopic Study in Rabbits

The ciliated epithelium of the rabbit trachea was irradiated with daily fractions of 2 Gy up to an accumulated dose of 20 Gy (total dose: 2, 6, 10, 16, or 20 Gy). Fifteen to forty-five minutes before the start of each irradiation 0.3 mg Cis-diamminedichloroplatinum (cis-DDP) was given by intraperitoneal injection to each rabbit. Examinations were carried out 1-10 days after each fractionation schedule, when specimens were taken for morphological investigations. Scanning electron microscope (SEM) examination showed a gradual development of ciliary damage, from blebs on the cilia to swollen tips, broken and bent cilia and finally an epithelial injury with areas free from cilia, and a surface covered with microvilli-like structures. SEM also showed cell loss, and remnants of dead cells on the surface together with detritus. By transmission electron microscopy (TEM), ciliary damage, cell death and cell loss of the ciliated cell layer, as well as exfoliation of portions of goblet-like cells on the surface, could be confirmed. Scoring of SEM and TEM micro graphs showed that for the tracheal part treated with cis-DDP and radiation, the maximal damage was expressed in the dose group 10 Gy, and above this no further increase in the average reaction occurred. For the part of the trachea only exposed to cis-DDP, the damage increased with the dose. The difference observed speaks for an accelerated proliferation exerted by the radiation

The Effect of Ionizing Irradiation on Type I Collagen of the Tail in Growing Mice: A Histology and Electron Microscopy Study

In order to examine the effect of radiation on growing tissue, especially the fibroblasts and their end-product, the collagen fibres, tails from 24 mice were irradiated at an age of 8 days with 20 Gy and 30 Gy (\u3e°Co). Tails from 18 animals served as controls. Six mice from each group were sacrificed on day 8, 20 and 30. Transmission electron microscopy was used to examine the fibroblasts and the collagen fibrils. Non-irradiated fibroblasts had a nucleus rich in chromatin and an abundant endoplasmic reticulum with cistemae and condensing vacuoles. On day 20, approximately 50 % , and on day 30, 25 % of the fibroblasts irradiated with 30 Gy had a sparse endoplasmic reticulum pointing to a reduction of protein synthesis. While, on day 20, the fibrils irradiated with 20 Gy and with 30 Gy had significantly larger diameters compared to the controls, on day 30, the irradiated fibrils had a notably smaller diameter compared to the controls; 30 Gy-fibrils were larger than the 20 Gy-fibrils on both days. On day 20, the binding mean value of the 30 Gy-fibrils exceeded that of the controls and was significantly higher than that of the 20 Gy-fibrils, which was lower, though not significantly, than the controls. On day 30, the banding mean value of the 30 Gy-fibrils was notably lower than the control; and the value of the 20 Gy-fibrils was significantly lower than that of the 30 Gy-fibrils. The results are explained as an edema together with an inhibitory effect on the protein synthesis of the fibroblasts caused by the irradiation. This deduction 1s further supported by light microscopy of the tails

Fully engineered homoepitaxial zinc oxide nanopillar array for near-surface light wave manipulation

We report accurate light wave manipulation by means of an inverse designed homoepitaxial ZnO nanopillar array. Our proof-of-concept structure was optimized for focusing a near-surface light beam which propagates in a free-space parallel to the metal top surface. The on-purpose positioned and perpendicularly aligned vertical ZnO nanopillars were fabricated by homoepitaxial chemical growth technique. The obtained focal distance of 28 (mű)m as well as the light intensity distribution pattern was verified by three-dimensional finite-difference time-domain method. The demonstrated approach can provide inter- and intrachip optical connections in the next generation ZnO nanowire-based integrated photonic devices

Allelic loss at chromosome 13q12-q13 is associated with poor prognosis in familial and sporadic breast cancer.

Loss of heterozygosity (LOH) was analysed in 84 primary tumours from sporadic, familial and hereditary breast cancer using five microsatellite markers spanning the chromosomal region 13q12-q13 which harbours the BRCA2 breast cancer susceptibility gene, and using one other marker located within the RBI tumour-suppressor gene at 13q14. LOH at the BRCA2 region was found in 34% and at RBI in 27% of the tumours. Selective LOH at BRCA2 occurred in 7% of the tumours, whereas selective LOH at RBI was observed in another 7%. Moreover, a few tumours demonstrated a restricted deletion pattern, suggesting the presence of additional tumour-suppressor genes both proximal and distal of BRCA2. LOH at BRCA2 was significantly correlated to high S-phase values, low oestrogen and progesterone receptor content and DNA non-diploidy. LOH at BRCA2 was also associated, albeit non-significantly, with large tumour size and the ductal and medullar histological types. No correlation was found with lymph node status, patient age or a family history of breast cancer. A highly significant and independent correlation existed between LOH at BRCA2 and early recurrence and death. LOH at RBI was not associated with the above mentioned factors or prognosis. The present study does not provide conclusive evidence that BRCA2 is the sole target for deletions at 13q12-q13 in breast tumours. However, the results suggest that inactivation of one or several tumour-suppressor genes in the 13q12-q13 region confer a strong tumour growth potential and poor prognosis in both familial and sporadic breast cancer

Scanning Electron Microscopy of Human Esophageal Mucosa in Patients with Carcinoma of the Esophagus

Specimens taken at surgery from 15 patients with carcinoma of the esophagus were examined with scanning electron microscopy. Nine patients were treated with chemotherapy (cisplatin + 5-fluorouracil), surgery and radiotherapy; one received preoperative radiotherapy only; and the remaining five primary surgery only. Scanning electron microscopy was performed on specimens of both tumor tissue and the mucosa at least 5 cm from the tumor. In adjacent non-tumor tissue, damage due to treatment was observed in the form of changes in microridges and increased cell loss. In tumor tissue, the degree of damage was correlated to tumor response to treatment. For patients with no residual tumor after treatment, the ultrastructure was normalized with a low tumor score, while for patients with residual tumor, the score was high