Comparative study of DNA damage and repair in head and neck cancer after radiation treatment

We compared DNA damage and the efficacy of its repair after genotoxic treatment with γ-radiation of lymphocytes and tissue cells isolated from patients with squamous cell carcinoma of head and neck (HNSCC) and healthy donors. Thirty-seven subjects with HNSCC and 35 healthy donors were enrolled in the study. The extent of DNA damage including oxidative lesions and efficiency of the repair were examined by alkaline comet assay. HNSCC cancer cells were more sensitive to genotoxic treatment and displayed impaired DNA repair. In particular, lesions caused by γ-radiation were repaired less effectively in metastasis of HNSCC than in healthy controls. The differences in radiation sensitivity of cancer and control cells suggested that DNA repair might be critical for HNSCC treatment. We conclude that γ-radiation might be considered as an effective therapeutic strategy for head and neck cancers, including patients in advanced stage of the disease with clear evidence of metastasis.     

New bradykinin analogues substituted in positions 7 and 8 with sterically restricted 1-aminocyclopentane-1-carboxylic acid.

A sterically constrained non-coded amino acid, 1-aminocyclopentane-1-carboxylic acid (Apc), was introduced in position 7 or 8 of the bradykinin (BK) B(2) receptor antagonist, [D-Arg(0), Hyp(3), Thi(5, 8), D-Phe(7)]BK, previously synthesized by Stewart's group. This modification is believed to reduce the flexibility of the peptides, thereby forcing the peptide backbone and side chains to adopt specific orientations. Apc substitution was combined with acylation of the N-terminus with 1-adamantaneacetic acid (Aaa). The activity of four new analogues was assayed in isolated rat uterus and in rat blood pressure tests. The results clearly demonstrated that the Apc residue inserted in position 7 led to a reduction of antagonistic properties in the rat uterus assay or even restored the agonism in the blood pressure test, whereas Apc at position 8 enhanced antagonistic potency in both the tests. In both cases, acylation of the N-terminus led to the enhancement of the antagonistic potency. On the basis of these findings, new potent and selective B(2) blockers might be designed.     

Analysis of apoptosis by cytometry using TUNEL assay

Activation of endonucleases that cleave chromosomal DNA preferentially at internucleosomal sections is a hallmark of apoptosis. DNA fragmentation revealed by the presence of a multitude of DNA strand breaks, therefore, is considered to be the gold standard for identification apoptotic cells. Several variants of the methodology that is based on fluorochrome-labeling of 3'-OH termini of DNA strand breaks in situ with the use of exogenous terminal deoxynucleotidyl transferase (TdT), commonly defined as the TUNEL assay, have been developed by us. This Chapter describes the variant based on strand breaks labeling with Br-dUTP that is subsequently detected immunocytochemically with Br-dUAb. Compared with other TUNEL variants the Br-dU-labeling assay offers the greatest sensitivity in detecting DNA breaks. Described also are modifications of the protocol that allow one to use other than Br-dUTP fluorochrome-tagged deoxynucleotides to label DNA breaks. Concurrent staining of DNA with propidium or 4',6-diamidino-2-phenylindole (DAPI) and multiparameter analysis of cells by flow- or laser scanning cytometry enables one to correlate induction of apoptosis with the cell cycle phase.     

Bloodstream Infections in the Intensive Care Unit: A Single-Center Retrospective Bacteriological Analysis Between 2007 and 2019

Hospital-acquired bloodstream infections are a severe worldwide problem associated with significant morbidity and mortality. This retrospective, single-center study aimed to analyze bloodstream infections in patients hospitalized in the intensive care unit of the Military Institute of Medicine, Poland. Data from the years 2007–2019 were analyzed. When the infection was suspected, blood samples were drawn and analyzed microbiologically. When bacterial growth was observed, an antimicrobial susceptibility/resistance analysis was performed. Among 12,619 analyzed samples, 1,509 were positive, and 1,557 pathogens were isolated. In 278/1,509 of the positive cases, a central line catheter infection was confirmed. Gram-negative bacteria were the most frequently (770/1,557) isolated, including Acinetobacter baumannii (312/770), Klebsiella pneumoniae (165/770; 67/165 were the isolates that expressed extended spectrum beta-lactamases (ESBL), 5/165 isolates produced the New Delhi metallo-β-lactamases (NDM), 4/165 isolates expressed Klebsiella pneumoniae carbapenemase (KPC), and 1/165 isolate produced OXA48 carbapenemase), Pseudomonas aeruginosa (111/770; 2/111 isolates produced metallo-β-lactamase (MBL), and Escherichia coli (69/770; 11/69 – ESBL). Most Gram-positive pathogens were staphylococci (545/733), mainly coagulase-negative (368/545). Among 545 isolates of the staphylococci, 58 represented methicillin-resistant Staphylococcus aureus (MRSA). Fungi were isolated from 3.5% of samples. All isolated MRSA and methicillin-resistant coagulase-negative Staphylococcus (MRCNS) strains were susceptible to vancomycin, methicillin-sensitive Staphylococcus aureus (MSSA) isolates – to isoxazolyl penicillins, and vancomycin-resistant Enterococcus (VRE) – to linezolid and tigecycline. However, colistin was the only therapeutic option in some infections caused by A. baumannii and KPC-producing K. pneumoniae. P. aeruginosa was still susceptible to cefepime and ceftazidime. Echinocandins were effective therapeutics in the treatment of fungal infections.     

Ribonuclease activity in roots of soybean seedlings subjected to chilling stress and recovery

Many developmental and physiological changes, including alterations of enzyme activities, occur in plants under low temperature stress. In this study the total ribonuclease activity was determined in crude extracts from root tips of soybean seedlings germinated at 25 °C, subjected to chilling conditions (10°C) and recovered at optimal temperature (25°C). Measurements of RNase activity were performed every 24 hours starting from the third to the 10-th day of growth. We found that chilling caused a considerable increase in ribonuclease activity (in comparison with the control), with an activity peak on the fourth day of the cold treatment. The enzyme activity in root extracts of the plants recovered after cold stress decreased along with the time of recovery. No differences were found in approximate molecular weight (35 kDa) and pH optimum (6.0) for ribonucleases extracted from control and chilled soybean roots.     

Two new species of the genus Pelexia (Orchidaceae, Spiranthinae) from South America

Szlachetko, D. L. 1995. Two new species of the genus Pelexia (Orchidaceae, Spiranthinae) from South America. - Nord. J. Bot. 15: 173–175. Copenhagen. ISSN 0107–055X.
Pelexia sheviakii and Pelexia collocaliae are described as new species from Ecuador and Paraguay respectively. Pelexia sheviakii differs from Pelexia bonariensis and any other species related by its lip form, which is rhomboid, has no constriction, and with basal lip thickenings produced on upper surface of claw. The most characteristic features of Pelexia collocaliae are U-shaped callus at apices of petals, erect flowers, straight lateral sepals and narrow lip with two small calli near isthmus.     

If Artificial In Vitro Microenvironment Can Influence Tumor Drug Resistance Network via Modulation of lncRNA Expression?—Comparative Analysis of Glioblastoma-Derived Cell Culture Models and Initial Tumors In Vivo

Cellular and Molecular Neurobiology - The tumor resistance of glioblastoma cells in vivo is thought to be enhanced by their heterogeneity and plasticity, which are extremely difficult to curb in...     

Morphogenetic response of shoot tips to cryopreservation by encapsulation-dehydration in a solid mutant and periclinal chimeras of <Emphasis Type="Italic">Chrysanthemum</Emphasis> × <Emphasis Type="Italic">grandiflorum</Emphasis> /Ramat./Kitam.

Cryopreservation is widely applied to many economically important species excluding chimera plants which are problematic for long-term conservation. Their storage problems can be circumvented only by cryopreserving meristems. This study looked at the morphogenetic response of shoot tips of periclinal chimera chrysanthemum ‘Lady Orange’ and ‘Lady Salmon’, as well as the solid mutant ‘Richmond’, that were cryopreserved by encapsulation-dehydration technique. By applying 10 µM ABA in the preculture medium followed by 4-day-long dehydration treatment, the explant survival reached up to 67%. Besides the stimulation of typical single shoot recovery, cryopreservation led to direct or indirect multiple shoot formation, shoot malformation, as well as inhibited their spontaneous rooting. Microscopic analysis revealed three types of structural damages of shoot tips which can correspond with their morphogenetic response in recovery culture. No influence of cryostorage on the acclimatisation efficiency of the recovered chrysanthemums was observed.     

The arterial circle of the brain,its branches and connections in selected representatives of the Antilopinae

The arterial circle of the brain, that is, the circle of Willis, and its branches in ruminants have been chiefly described in farm animals and only in selected wild species. In view of the deficit of information about this vascular region in numerous other species of the Ruminantia, the arteries of the encephalic base were analyzed in five antelope species representing different genera of the Bovidae, Antilopinae. Specimens of the following species were examined: springbuck (Antidorcas marsupialis), blackbuck (Antilope cervicapra), dik‐dik (Madoqua kirkii), saiga (Saiga tatarica), and oribi (Ourebia ourebi). Post‐autopsy material received from domestic zoological gardens was used to inject the bilateral common carotid arteries with a stained acetone solution of vinyl superchloride. When the material was polymerized, the specimens were macerated enzymatically. The process resulted in casts of arteries of the head and encephalic base on a skeletal scaffold. The investigations revealed that the bilateral components of the arterial circle of the brain, that is, the rostral cerebral artery and caudal communicating artery, arose from the division of the intracranial segment of the internal carotid artery, which emerges from the rostral epidural rete mirabile. The extracranial segment of the internal carotid artery was obliterated. In consequence of this process, the blood reaches the brain chiefly from the maxillary artery. The research proved that the arteries of the encephalic base in the Antilopinae are most similar to the vessels described in antelopes of Tragelaphus, Taurotragus, and Boselaphus genera and small domestic ruminants. However, they are different from the arterial pattern of the encephalic base in bovines and other species classified as the Bovini. J. Morphol. 276:766–771, 2015. © 2015 Wiley Periodicals, Inc.