Effect of light intensity and ammonium-N on carotenogenesis ofTrentepohlia odorata andDunaliella bardawil

AxenicTrentepohlia odorata was cultured at three different NH₄Cl levels (3.5 × 10^–2, 3.5 × 10^–3, 3.5 × 10^–4 M) and three different light intensities (48, 76, 122 µmol m^–2 s^–1). Chloride had no effect on growth over this range of concentration. High light intensity and high NH₄Cl concentration enhanced the specific growth rate. The carotenoid content increased under a combination of high light intensity and low N concentration. WhenD. bardawil was exposed to the same combination of growth conditions, there was an increase in its carotenoid content. The light saturation and the light inhibition constants (K _s andK _i, respectively) for growth, and the saturation constant (K _m) for NH₄Cl were determined. TheK _s andK _i values were higher inT. odorata (66.7 and> 122 mol m^–2 s^–1, respectively) than inD. bardawil (5.1 and 14.7 µmol m^–2 s^–1, respectively). TheK _m value determined at 122 µmol m^–2 s^–1, however, was lower inT. odorata (0.048 µM) than inD. bardawil (0.062 µM).Author for correspondence     

Assignment of the dipeptidylpeptidase IV (DPP4) gene to pig Chromosome 15q21

A porcine 2-kb partial dipeptidylpeptidase IV (DPP4, EC 3.4.14.5) cDNA clone and a porcine 16-kb genomic fragment containing parts of the DPP4 gene were isolated, characterized, and used as probes to map the DPP4 gene to pig Chr (Chr) 15q21 by fluorescence in situ hybridization. A two-allele RFLP was revealed for the DPP4 gene. This polymorphism was utilized in a linkage test against the erythrocyte antigen G (EAG), previously assigned to Chr 15, and the microsatellite S0088, which is linked to EAG. The linkage analyses revealed significant evidence for linkage confirming the assignment of DPP4 to Chr 15.     

The int genes of bacteriophages P22 and λ are regulated by different mechanisms

Bacteriophage P22 and λ are related bacteriophages with similar gene organizations. In λ the cII-dependent P_I promoter is responsible for λint gene expression. The only apparent counterpart to P_I in P22 is oriented in the opposite direction, and cannot transcribe the P22 int gene. We show that this promoter, called P_al, is active both in vivo and in vitro, and is dependent upon the P22 cII-like gene, called c1. We have also determined the DNA sequence of a 3.3 kb segment that closes the gap between previously reported sequences to give a continuous sequence between the P22 p_L promoter and the int gene. The newly determined sequence is densely packed with genes from the p_L direction, and the proteins predicted by the sequence show excellent correlation with the proteins mapped by Youderian and Susskind in 1980. However, the sequence contains no apparent genes in the opposite (p_al) direction, and no additional binding motifs for the P22 c1 protein. We conclude that int gene expression in P22 is regulated by a different mechanism than in λ.     

Novel (E)-3-(3-Oxo-4-substituted-3,4-dihydro-2H-benzo[b][1,4]oxazin-6-yl)-N-hydroxypropenamides as Histone Deacetylase Inhibitors: Design,Synthesis and Bioevaluation

Herein, we report the design, synthesis and evaluation of novel (E)-3-(3-oxo-4-substituted-3,4-dihydro-2H-benzo[b][1,4]oxazin-6-yl)-N-hydroxypropenamides ( 4 a – i , 7 a – g ) targeting histone deacetylases. Three human cancer cell lines were used to test the cytotoxicity of the synthesized compounds (SW620, colon; PC-3, prostate; NCI−H23, lung cancer); inhibitory activity towards HDAC; anticancer activity; as well as their impact on the cell cycle and apoptosis. As a result, compounds 4 a – i bearing the alkyl substituents seemed to be less potent than the benzyl-containing compounds 7 a – g in all biological assays. Compounds 7 e – f were found to be the most active HDAC inhibitors with IC₅₀ of 1.498±0.020 μM and 1.794±0.159 μM, respectively. In terms of cytotoxicity and anticancer assay, 7 e and 7 f also showed good activity with IC₅₀ values in the micromolar range. In addition, the cell cycle and apoptosis of SW620 were affected by compound 7 f in almost a similar manner to that of reference compound SAHA. Docking assays were carried out for analysis the binding mode and selectivity of this compound toward 8 HDAC isoforms. Overall, our data confirmed that the inhibition of HDAC plays a pivotal role in their anticancer activity.     

Treatment-resistant depression: definition,prevalence, detection,management, and investigational interventions

Treatment-resistant depression (TRD) is common and associated with multiple serious public health implications. A consensus definition of TRD with demonstrated predictive utility in terms of clinical decision-making and health outcomes does not currently exist. Instead, a plethora of definitions have been proposed, which vary significantly in their conceptual framework. The absence of a consensus definition hampers precise estimates of the prevalence of TRD, and also belies efforts to identify risk factors, prevention opportunities, and effective interventions. In addition, it results in heterogeneity in clinical practice decision-making, adversely affecting quality of care. The US Food and Drug Administration (FDA) and the European Medicines Agency (EMA) have adopted the most used definition of TRD (i.e., inadequate response to a minimum of two antidepressants despite adequacy of the treatment trial and adherence to treatment). It is currently estimated that at least 30% of persons with depression meet this definition. A significant percentage of persons with TRD are actually pseudo-resistant (e.g., due to inadequacy of treatment trials or non-adherence to treatment). Although multiple sociodemographic, clinical, treatment and contextual factors are known to negatively moderate response in persons with depression, very few factors are regarded as predictive of non-response across multiple modalities of treatment. Intravenous ketamine and intranasal esketamine (co-administered with an antidepressant) are established as efficacious in the management of TRD. Some second-generation antipsychotics (e.g., aripiprazole, brexpiprazole, cariprazine, quetiapine XR) are proven effective as adjunctive treatments to antidepressants in partial responders, but only the olanzapine-fluoxetine combination has been studied in FDA-defined TRD. Repetitive transcranial magnetic stimulation (TMS) is established as effective and FDA-approved for individuals with TRD, with accelerated theta-burst TMS also recently showing efficacy. Electroconvulsive therapy is regarded as an effective acute and maintenance intervention in TRD, with preliminary evidence suggesting non-inferiority to acute intravenous ketamine. Evidence for extending antidepressant trial, medication switching and combining antidepressants is mixed. Manual-based psychotherapies are not established as efficacious on their own in TRD, but offer significant symptomatic relief when added to conventional antidepressants. Digital therapeutics are under study and represent a potential future clinical vista in this population.     

Heat shock in mechanically wounded carrot root disks causes destabilization of stable secretory protein mRNA and dissociation of endoplasmic reticulum lamellae

In many organisms, the synthesis of heat shock proteins during heat shock is concomitant with the cessation of at least a portion of normal cellular protein synthesis. Heat shocked barley aleurone layers selectively stop the synthesis and secretion of secretory proteins. Exposure to 40°C causes a disruption of endoplasmic reticulum (ER) lamellae, which we have hypothesized leads to the destabilization of otherwise stable mRNA previously associated with ER‐bound polyribosomes. We report here that this was also observed in wounded carrot ( Daucus carota L.) root parenchyma tissue which synthesizes and secretes cell wall proteins when mechanically wounded. Nondenaturing cationic polyacrylamide gel electrophoresis of radiolabeled proteins indicated that heat shock caused the cessation of the synthesis and secretion of extensin, a hydroxyproline‐rich cell wall glycoprotein. Northern blot analyses indicated that the mRNA levels for both extensin and another cell wall protein (p33) were rapidly diminished during heat shock. Under nonheat shock conditions extensin mRNA had a half‐life of greater than 4 h, but this appeared to be reduced to less than 30 min during heat shock. There was also a concomitant dissociation of ER lamellae in wounded, heat shocked carrot root tissue, as observed by transmission electron microscopy. These observations indicate that this response may be universal among plant secretory tissues.     

PHYLOGENY OF THE RUBIACEAE AND THE LOGANIACEAE: CONGRUENCE OR CONFLICT BETWEEN MORPHOLOGICAL AND MOLECULAR DATA?

Phylogenetic analyses of 33 genera of Rubiaceae were performed using morphological and a few chemical characters. Parsimony analysis based on 29 characters resulted in eight equally parsimonious trees, with a consistency index of 0.40 and a retention index of 0.69. These results were compared to a phylogenetic analysis of the same genera based on chloroplast DNA restriction site data. There are discrepancies between the two analyses, but if we consider groupings reflected in the present classification there is much congruency. With the exception of four genera, all the genera are positioned in the same group of taxa in the two analyses. Clades of taxa representing three of the four subfamilies (~the Antirheoideae, ~the Rubioideae, and the ~Ixoroideae) are monophyletic, while the fourth subfamily Cinchonoideae is shown to be paraphyletic. Both analyses support a widened tribe Chiococceae, including the former subtribe Portlandiinae (Condamineeae). Furthermore, in both analyses the tribe Hamelieae is placed outside the subfamily Rubioideae where it is now housed. In search for the most plausible sister group to the Rubiaceae, the genus Cinchona (Rubiaceae) was analyzed together with 13 genera of the Loganiaceae, Nerium (Apocynaceae), and Exacum (Gentianaceae). Cornus (Comaceae), Olea (Oleaceae), and these two genera together were used as outgroups. The analysis, including 25 characters, 16 taxa, and with Cornus and Olea together as an outgroup, resulted in four equally parsimonious trees, with a consistency index of 0.53 and a retention index of 0.62. The non-Loganiaceae taxa Cinchona (Rubiaceae), Nerium (Apocynaceae), and Exacum (Gentianaceae) were all found to have their closest relatives within the Loganiaceae indicating that the Loganiaceae are paraphyletic and ought to be reclassified. As a result of the morphological data the most plausible sister group to the Rubiaceae is the tribe Gelsemieae of the Loganiaceae.     

Internal pH crisis, lysine decarboxylase and the acid tolerance response of Salmonella typhimurium

Salmonella typhimurium possesses an adaptive response to acid that increases survival during exposure to extremely low pH values. The acid tolerance response (ATR) includes both log-phase and stationary-phase systems. The log-phase ATR appears to require two components for maximum acid tolerance, namely an inducible pH homeostasis system, and a series of acid-shock proteins. We have discovered one of what appears to be a series of inducible exigency pH homeostasis systems that contribute to acid tolerance in extreme acid environments. The low pH-inducible lysine decarboxylase was shown to contribute significantly to pH homeostasis in environments as low as pH 3.0. Under the conditions tested, both lysine decarboxylase and σ^s-dependent acid-shock proteins were required for acid tolerance but only lysine decarboxylase contributed to pH homeostasis. The cadBA operon encoding lysine decarboxylase and a lysine/cadaverine antiporter were cloned from S. typhimurium and were found to be 79% homologous to the cadBA operon from Escherichia coli . The results suggest that S. typhimurium has a variety of means of fulfilling the pH homeostasis requirement of the ATR in the form of inducible amino acid decarboxylases.     

Cell separation from high cell density broths of Alcaligenes eutrophus by using a coagulant

Summary Alcaligenes eutrophus was successfully recovered from high cell density broths by pre-treatment with polyaluminium hydroxide chloride silicate as a coagulant at 36–90 mg Al/l. The optimum pH range for cell coagulation was 10–12. Subsequent centrifugation (45×g) and filtration (pore size 0.5 mm) gave a cell recovery of higher than 90%. The energy demand for cell recovery with the coagulant was only 3–11% of that without it.