New chromosome counts in the Centaurea Jacea group (Asteraceae, Cardueae) and some related taxa

Twenty-seven chromosome counts are reported in 23 species of the genus Centaurea , mostly eastern endemic species of the Jacea group, which has become the core of the re-defined genus Centaurea . Twenty reports are new, one is a correction of a previous count, one is a confirmation of limited previous data and one represents a new basic number in the Centaureinae. The prevalence of the basic chromosome number x  = 9 among the Eastern sections of the Jacea group is confirmed, together with the close correlation between karyological data and classification of the genus. Two alternative hypotheses on the aberrant chromosome number (for the Centaureinae) found in C. behen are proposed. One of them, if verified, would confirm that a cycle of polyploidy and descending dysploidy is a key mechanism in the speciation of the group.  © 2004 The Linnean Society of London, Botanical Journal of the Linnean Society , 2004, 145 , 345–352.     

Water-Stress Induced Changes in Concentrations of Proline and Other Solutes in Growing Regions of Young Barley Leaves

Riazi, A., Matsuda, K. and Arslan, A. 1985. Water-stress inducedchanges in concentrations of proline and other solutes in growingregions of young barley leaves.—J. exp. Bot. 36: 1716–1725. Young, intact barley Hordeum vulgare L. cv. ‘Arivat’seedlings stressed with PEG or NaCl were measured for waterstatus and levels of proline, sugars and inorganic cations ingrowing (basal 1.0 cm) and other areas of leaves. In growingregions, reductions in _n were found within 1 h in seedlingsstressed with PEG (–0.8 M Pa) but 4 h were required beforeproline increased and proline accounted for less than 5% ofthe osmotic adjustment after 24 h. Increases in proline occurredto a lesser extent in expanded mid-blade regions where osmoticadjustment was less. After one or more days stress, prolinelevels in basal tissues were 10 x higher than in mid-blade tissues,and proline increases in these and intervening tissues occurredwithout loss of turgor. When seedlings were stressed for extendedperiods with mild to moderate concentrations of PEG, prolineelevations in basal to mid-blade areas were proportional toreductions in tissue and _n NaCl-stress led to similar responsesexcept prohne increases per unit decrease in _x, were 2–3x greater than in PEG-stressed tissues. Time-course studiesshowed levels of inorganic cations were not altered in the growingareas during the first few h of PEG-induced stress, but glucoseincreased as _x, decreased. The results showed that proline increaseis not the cause but could be a consequence of osmotic adjustment,and its increase is not due to cell death. They also providedindependent evidence that stress responses of growing tissuesdiffer substantially from expanded areas in young barley leaves. Key words: Proline, water stress, growing regions     

Evolutionary history of mole rats (genus Nannospalax) inferred from mitochondrial cytochrome b sequence

Mole rats (genus Nannospalax) display prolific chromosomal variation with more than 50 distinct cytotypes. These cytotypes are largely indistinguishable morphologically, are mainly allopatric and their taxonomic ranking is contradictory. We established a cytochrome b phylogeny for 15 cytotypes belonging to all three species recognized on morphological grounds (morphospecies): N. leucodon, N. xanthodon and N. ehrenbergi. Phylogenetic reconstructions yielded two highly divergent groups which are in agreement with the current division into two subgenera (Nannospalax and Mesospalax). The former comprised samples from south‐eastern Turkey, Israel and Egypt (the morphospecies N. ehrenbergi). Basal dichotomy within Mesospalax remained unresolved and the putative sister position of N. leucodon against the two lineages of N. xanthodon was not supported in our analysis. Net divergences between sister cytotypes were low (< 2.0%) and two N. leucodon cytotypes were not even reciprocally monophyletic. Among the three morphospecies, the genetic diversity was lowest in N. leucodon (2.4% ± 0.3%), highest in N. xanthodon (8.8% ± 0.7%) and intermediate in N. ehrenbergi (5.0% ± 0.5%). Our results show that associations between genetic and chromosomal variation are not widespread and common in mole rats, and therefore refute the generalization of a ‘cytotype‐equals‐species’ approach. © 2011 The Linnean Society of London, Biological Journal of the Linnean Society, 2012, 105 , 446–455.     

Differential in vitro inhibition effects of some antibiotics on tumor associated carbonic anhydrase isozymes of hCA-IX and hCA-XII

Hypoxia is a common characteristic of locally advanced solid tumors that has been associated with diminished therapeutic response and malignant progression. Human carbonic anhydrase (hCA) hCA IX and XII isozymes are tumor associated isoforms which contribute to acidification of the tumor environment by catalyzing the hydration of carbon dioxide to bicarbonate and protons.In the present study our goal was to investigate the inhibition effects of 15 different antibiotics belonging to the following classes: Lactams, cephalosporins, macrolides etc., on the tumor associated carbonic anhydrase isozymes hCA-IX, hCA-XII and cytosolic carbonic anhydrase hCA-I and hCA-II.     

Germination responses to GA3 and short‐time chilling of three endemic species: Tripleurospermum pichleri,Cirsium leucopsis and Senecio olympicus (Asteraceae)

In the present study, the germination characteristics of three endemic species from Turkey, Tripleurospermum pichleri (Boiss.) Bornm., Cirsium leucopsis D.C and Senecio olympicus Boiss. (Asteraceae), were investigated. Germination was studied for fresh seeds, for seeds subjected to short‐time chilling (15 days, moist +4°C), to GA₃ (100, 150 and 250 ppm) and a combination of chilling and GA₃; in all cases seeds were incubated either at 20/10°C day/night with light daytime or at 20°C in darkness with daily short‐time dim light (DSDL). In C. leucopsis seeds, all GA₃ treatments enhanced the final germination percentages. The mean germination time (MGT) of C. leucopsis was lower under DSDL than with photoperiod. The chilling treatment with GA₃ in DSDL significantly increased germination in S. olympicus seeds (from 45 to 87%). Germination increased to 55% in T. pichleri by chilling under photoperiod compared with 32% by chilling followed by DSDL. In conclusion, these three co‐existing endemic Asteraceae species have different germination behaviours; something that should be taken into account for ex situ propagation. However, an efficient way to germinate all species is to use 250 ppm GA₃ and 20/10°C with photoperiod.     

Treatment of COVID-19 patients with quercetin: a prospective,single center,randomized, controlled trial

Scientific research continues on new preventive and therapeutic strategies against severe acute respiratory syndrome Coronavirus-2 (SARS-CoV-2). So far, there is no proven curative treatment, and a valid alternative therapeutic approach needs to be developed. This study is designed to evaluate the effect of quercetin in COVID-19 treatment. This was a single-centre, prospective randomized controlled cohort study. Routine care versus QCB (quercetin, vitamin C, bromelain) supplementation was compared between 429 patients with at least one chronic disease and moderate-to-severe respiratory symptoms. Demographic features, signs, laboratory results and drug administration data of patients were recorded. The endpoint was that QCB supplementation was continued throughout the follow-up period from study baseline to discharge, intubation, or death. The most common complaints at the time of hospital admission were fatigue (62.4%), cough (61.1%), anorexia (57%), thirst (53.7%), respiratory distress (51%) and chills (48.3%). The decrease in CRP and ferritin levels was higher in the QCB group (all Ps were < 0.05). In the QCB group, the increase in platelet and lymphocyte counts was higher (all Ps were < 0.05). QCB did not reduce the risk of events during follow-up. Adjustments for statistically significant parameters, including the lung stage, use of favipiravir and presence of comorbidity did not change the results. While there was no difference between the groups in terms of event frequency, the QCB group had more advanced pulmonary findings. QCB supplement is shown to have a positive effect on laboratory recovery. While there was no difference between the groups in terms of event frequency, QCB supplement group had more advanced pulmonar findings, and QCB supplement is shown to have a positive effect on laboratory recovery/results. Therefore, we conclude that further studies involving different doses and plasma level measurements are required to reveal the dose/response relationship and bioavailability of QCB for a better understanding of the role of QCB in the treatment of SARS CoV-2.