New class of steroidal alkaloids from Fritillaria imperialis

Two members of a new class of C-nor-D-homo steroidal alkaloids, impranine (1). and dihydroimpranine (2). along with a new pyridyl-pregnane-type steroidal alkaloid, fetisinine (3). and a known base, korsevine (4). were isolated from the bulbs of Fritillaria imperialis. The structures of the compounds were established on the basis of spectroscopic techniques and some chemical transformations. Compounds 1 and 2 form a new class of steroidal alkaloids, named as "impranane."     

Event related desynchronization: use as a neurophysiologic marker is restricted

The present research aims to show that the occurrence of alpha blocking or event-related desynchronization (ERD) strongly depends on the amplitude and also on the phase angle of alpha activity at the stimulus onset. Simple visual stimulation was presented to 17 healthy subjects during EEG recording. An O₂ electrode was used for analysis with a 32 channel EEG sampling system. We used a segmentation of raw data in order to obtain the evoked potential. Prestimulus and poststimulus activities were filtered in the alpha (8–13 Hz) frequency band. Later, four different events (blocked, time-locked, phase-locked, and eliminated) were separately averaged. Phase-locked sweeps were determined by application of inter-trial coherence analysis. The evaluation of the data shows that “time-locked and phase-locked sweeps” were the dominating pattern and not “the blocked pattern”, which occurred only when the prestimulus alpha was high. In the analyses of EEG-EP sweeps, only 22 % of epochs showed (ERD). The ANOVA revealed significant differences between four different alpha responses (F(3,48) = 11.175; p < 0.001). Furthermore, alpha oscillations in time-locked responses were significantly higher than blocked (p < 0.0001). The analyses clearly demonstrate that important precaution is needed when using the ERD as a cognitive or pathological marker.     

PROGRESS STUDY: Progression of chronic kidney disease in children and heat shock proteins

Various molecular and cellular processes are involved in renal fibrosis, such as oxidative stress, inflammation, endothelial cell injury, and apoptosis. Heat shock proteins (HSPs) are implicated in the progression of chronic kidney disease (CKD). Our aim was to evaluate changes in urine and serum HSP levels over time and their relationships with the clinical parameters of CKD in children. In total, 117 children with CKD and 56 healthy children were examined. The CKD group was followed up prospectively for 24 months. Serum and urine HSP27, HSP40, HSP47, HSP60, HSP70, HSP72, and HSP90 levels and serum anti-HSP60 and anti-HSP70 levels were measured by ELISA at baseline, 12 months, and 24 months. The urine levels of all HSPs and the serum levels of HSP40, HSP47, HSP60, HSP70, anti-HSP60, and anti-HSP70 were higher at baseline in the CKD group than in the control group. Over the months, serum HSP47 and HSP60 levels steadily decreased, whereas HSP90 and anti-HSP60 levels steadily increased. Urine HSP levels were elevated in children with CKD; however, with the exception of HSP90, they decreased over time. In conclusion, our study demonstrates that CKD progression is a complicated process that involves HSPs, but they do not predict CKD progression. The protective role of HSPs against CKD may weaken over time, and HSP90 may have a detrimental effect on the disease course.Supplementary InformationThe online version contains supplementary material available at 10.1007/s12192-021-01239-9.     

Kinetic analysis of the inhibitory effect of trichloroethylene (TCE) on nitrification in cometabolic degradation

In this study, the inhibitory effect of TCE on nitrification process was investigated with an enriched nitrifier culture. TCE was found to be a competitive inhibitor of ammonia oxidation and the inhibition constant (K _I ) was determined as 666–802 μg/l. The TCE affinity for the AMO enzyme was significantly higher than ammonium. The effect of TCE on ammonium utilization was evaluated with linearized plots of Monod equation (e.g., Lineweaver–Burk, Hanes–Woolf and Eadie–Hofstee plots) and non-linear least square regression (NLSR). No significant differences were found among these data evaluation methods in terms of kinetic parameters obtained.     

Realizing the promise of population biobanks: a new model for translation

The promise of science lies in expectations of its benefits to societies and is matched by expectations of the realisation of the significant public investment in that science. In this paper, we undertake a methodological analysis of the science of biobanking and a sociological analysis of translational research in relation to biobanking. Part of global and local endeavours to translate raw biomedical evidence into practice, biobanks aim to provide a platform for generating new scientific knowledge to inform development of new policies, systems and interventions to enhance the public’s health. Effectively translating scientific knowledge into routine practice, however, involves more than good science. Although biobanks undoubtedly provide a fundamental resource for both clinical and public health practice, their potentiating ontology—that their outputs are perpetually a promise of scientific knowledge generation—renders translation rather less straightforward than drug discovery and treatment implementation. Biobanking science, therefore, provides a perfect counterpoint against which to test the bounds of translational research. We argue that translational research is a contextual and cumulative process: one that is necessarily dynamic and interactive and involves multiple actors. We propose a new multidimensional model of translational research which enables us to imagine a new paradigm: one that takes us from bench to bedside to backyard and beyond, that is, attentive to the social and political context of translational science, and is cognisant of all the players in that process be they researchers, health professionals, policy makers, industry representatives, members of the public or research participants, amongst others.     

Effects of citalopram on cognitive performance in passive avoidance, elevated plus-maze and three-panel runway tasks in naïve rats

Recent studies have shown that learning and memory capacity is disturbed in depressive patients, and it is important to reveal the effects of antidepressant drugs on cognitive function in depressive patients with memory problems. Citalopram, a selective serotonin reuptake inhibitor (SSRI), is one of the most widely used drugs for the treatment of disorders related to serotonergic dysfunction like depression and anxiety. Contradictory findings exist regarding the effects of SSRIs on memory. The aim of this study is to investigate whether citalopram affects memory in various models of learning and memory tasks in rats. Citalopram (at 20 and 50 mg/kg) significantly shortened the retention latency in the passive avoidance test and prolonged the transfer latency on the second day at 10 and 50 mg/kg doses in the elevated plus-maze test. Citalopram also significantly increased the number of errors (at the 10 mg/kg dose) and prolonged the latency values compared to the control group in both reference and working memory trials in the three-panel runway test. Citalopram also impaired reference memory trials of animals at the 20 mg/kg dose. In conclusion, citalopram impaired cognitive performance in passive avoidance, elevated plus-maze and three-panel runway tasks in naive rats. These effects might be related to serotonergic and nitrergic mechanisms, which need to be investigated in further studies.     

Higher Seroprevalence of Hepatitis B Virus Antigen in Patients with Cystic Hydatid Disease than in Patients Referred to Internal Medicine Clinics in Turkey

Turkey remains an intermediate area for prevalence of hepatitis B virus (HBV) surface antigenemia. The sheep-raising areas of Turkey also pose a high risk for cystic hydatid disease (CHD). Both HBV infection and CHD are major public health issues particularly in eastern parts of Turkey; however, there is no data regarding HBV infection in patients who have had CHD. The aims of this study were to evaluate the association between HBV infection and CHD and suggest ways to reduce HBV infection which is still widespread in Turkey. A retrospective study was conducted with 94 adult patients with active CHD referred to the hepatology department, Yuzuncuyil University School of Medicine from December 2010 to December 2012. All subjects came from rural areas of the region and underwent ultrasonography of abdomen which detected CHD of the liver. All the patients were serologically positive for Echinococcus granulosus. The control group consisted of 500 patients (300 men and 200 women) referred to the internal medicine clinics for other reasons. The patients with CHD and in the control group were tested for the existence of HBs antigen according to the standard procedures. The seroprevalence of HBs antigen was significantly higher in patients with active CHD than those in the control group (12.7% vs 5.2%; P=0.0017). Our data indicate that there is significant association between HBV infection and CHD. All patients with CHD should be screened for HBV infection.     

Sequence homology of polymorphic AFLP markers in garlic (Allium sativum L.).

Linkage mapping and genetic diversity studies with DNA markers in plant species assume that comigrating bands are identical, or at least that they have homologous sequences. To test this assumption in a plant with a large genome, sequence identities of 7 polymorphic amplified fragment length polymorphism (AFLP) markers of garlic, previously used to estimate similarity in genetic diversity studies, were characterized. Among 37 diverse garlic clones, 87 bands from these 7 polymorphisms were excised, amplicons were cloned, and 2 to 6 colonies were sequenced from each band, to yield a total of 191 DNA amplicons. Of these 87 bands, 83 bands (95.4%) contained AFLP amplicons that were identical or highly homologous to the typical marker of that band; only 4 bands contained amplicons with little homology to the same-sized amplicons of other garlic clones. Of these 83 bands, 64 (73.6%) contained only highly homologous amplicons (>90% sequence identity), whereas 19 (21.8%) contained both homologous and nonhomologous amplicons, with sequence identities less than 60%. Of the 37 nonhomologous amplicons identified, 25 (67.5%) differed in length from other amplicons in the band. Sequence conservation of AFLP amplicons followed patterns similar to phylogenetic relationships among garlic clones, making them useful for developing simple PCR-based markers in genetic mapping and diversity assessment.     

Wnt11/beta-catenin signaling in both oocytes and early embryos acts through LRP6-mediated regulation of axin

Current models of canonical Wnt signaling assume that a pathway is active if beta-catenin becomes nuclearly localized and Wnt target genes are transcribed. We show that, in Xenopus, maternal LRP6 is essential in such a pathway, playing a pivotal role in causing expression of the organizer genes siamois and Xnr3, and in establishing the dorsal axis. We provide evidence that LRP6 acts by degrading axin protein during the early cleavage stage of development. In the full-grown oocyte, before maturation, we find that axin levels are also regulated by Wnt11 and LRP6. In the oocyte, Wnt11 and/or LRP6 regulates axin to maintain beta-catenin at a low level, while in the embryo, asymmetrical Wnt11/LRP6 signaling stabilizes beta-catenin and enriches it on the dorsal side. This suggests that canonical Wnt signaling may not exist in simple off or on states, but may also include a third, steady-state, modality.     

Effects of lipopolysaccharide on blood-brain barrier permeability during pentylenetetrazole-induced epileptic seizures in rats

We investigated the effects of lipopolysachharide (LPS) on functional and structural properties of the blood-brain barrier (BBB) during pentylenetetrazole (PTZ)-induced epileptic seizures in rats. Arterial blood pressure was significantly elevated during epileptic seizures irrespective of LPS pretreatment. Plasma levels of interleukin (IL)-1, interleukin (IL)-6, nitric oxide (NO) and malondialdehyde (MDA) increased while catalase concentrations decreased in animals treated with LPS, PTZ and LPS plus PTZ. The significantly increased BBB permeability to Evans blue (EB) dye in the cerebral cortex, diencephalon and cerebellum regions of rats by PTZ-induced seizures was markedly reduced upon LPS pretreatment. Immunoreactivity for tight junction proteins, zonula occludens-1 and occludin, did not change in brain vessels of animals treated with PTZ and LPS plus PTZ. Glial fibrillary acidic protein immunoreactivity was increased in LPS, but not in PTZ and LPS plus PTZ. These results indicate that LPS pretreatment reduces the passage of EB dye bound to albumin into the brain, at least partly, by increasing plasma NO and IL-6 levels during PTZ-induced epileptic seizures. We suggest that LPS may provide protective effects on the BBB integrity during epileptic seizures through transcellular pathway, since the paracellular route remained unaffected by LPS and LPS plus PTZ.