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Obesity is a risk factor for poor transplant outcomes in the adult population. The effect of pre-transplant weight on pediatric kidney transplantation is conflicting in the existing literature. Data was collected from the Organ Procurement and Transplantation Network (OPTN) database on recipients aged 2–21 years who received a kidney-only transplant from 1987 to 2017. Recipients were categorized into underweight, normal, overweight, and obese cohorts. Using adjusted regression models, the relationship between recipient weight and various graft outcomes (delayed graft function [DGF], acute rejection, prolonged hospitalization, graft failure, mortality) was examined. 18,261 transplant recipients (mean age 14.1 ± 5.5 years) were included, of which 8.7% were underweight, 14.8% were overweight, and 15% were obese. Obesity was associated with greater odds of DGF (OR 1.3 95% CI 1.13–1.49, p

We address a challenge in the engineering of proteins to redirect electron transfer pathways, using the bacterial photosynthetic reaction centre (RC) pigment–protein complex. Direct electron transfer is shown to occur from the QA quinone of the Rhodobacter sphaeroides RC containing a truncated H protein and bound on the quinone side to a gold electrode. In previous reports of binding to the quinone side of the RC, electron transfer has relied on the use of a soluble mediator between the RC and an electrode, in part because the probability of QB quinone reduction is much greater than that of direct electron transfer through the large cytoplasmic domain of the H subunit, presenting a ~ 25 A barrier. A series of C-terminal truncations of the H subunit were created to expose the quinone region of the RC L and M proteins, and all truncated RC H mutants assembled in vivo. The 45M mutant was designed to contain only the N-terminal 45 amino acid residues of the H subunit including the membrane-spanning α-helix; the mutant RC was stable when purified using the detergent N-dodecyl-β-d-maltoside, contained a near-native ratio of bacteriochlorophylls to bacteriopheophytins, and showed a charge-separated state of $${{\text{P}}^{\text{+}}}{{\text{Q}}_{\text{A}}^-}$$ . The 45M-M229 mutant RC had a Cys residue introduced in the vicinity of the QA quinone on the newly exposed protein surface for electrode attachment, decreasing the distance between the quinone and electrode to ~ 12 A. Steady-state photocurrents of up to around 200 nA/cm2 were generated in the presence of 20 mM hydroquinone as the electron donor to the RC. This novel configuration yielded photocurrents orders of magnitude greater than previous reports of electron transfer from the quinone region of RCs bound in this orientation to an electrode.

Fifteen Amaryllidaceae alkaloids (1–15) of various structural types were isolated by standard chromatographic methods from fresh bulbs of Narcissus poeticus cv. Pink Parasol. The chemical structures were elucidated by MS, and 1D and 2D NMR spectroscopic analyses, and by comparison with literature data. Narcipavline (5) and narcikachnine (6) are reported here for the first time. In their structure are combined two basic structural types of Amaryllidaceae alkaloids (galanthamine- and galanthindole-structural types), which represent a new structural type of these compounds. Alkaloids isolated in sufficient amounts were evaluated for their human erythrocytic acetylcholinesterase, and human serum butyrylcholinesterase (HuBuChE) inhibition activity using Ellman’s method. Z-Gly-Pro-p-nitroanilide was used as substrate in the prolyl oligopeptidase (POP) assay. Untested alkaloids were also screened for their cytotoxic activity against a small panel of human cancer cells, which spanned cell lines from different tissue types. In parallel, MRC-5 human fibroblasts were employed to determine overall toxicity against noncancerous cells. Some compounds were evaluated for their antiprotozoal activity. The newly isolated alkaloid narcipavline (5) showed interesting HuBuChE inhibition activity (IC50 = 24.4 ± 1.2 µM), and norlycoramine (11) demonstrated promising POP inhibition (IC50 = 0.21 ± 0.01 mM).

Irreversible inhibition of acetylcholinesterase (AChE) by organophosphates leads to many failures in living organism and ultimately in death. Organophosphorus compounds developed as nerve agents such as tabun, sarin, soman, VX and others belong to the most toxic chemical warfare agents and are one of the biggest threats to the modern civilization. Moreover, misuse of nerve agents together with organophosphorus pesticides (e.g. malathion, paraoxon, chlorpyrifos, etc.) which are annually implicated in millions of intoxications and hundreds of thousand deaths reminds us of insufficient protection against these compounds. Basic treatments for these intoxications are based on immediate administration of atropine and acetylcholinesterase reactivators which are currently represented by mono- or bis-pyridinium aldoximes. However, these antidotes are not sufficient to ensure 100 % treatment efficacy even they are administered immediately after intoxication, and in general, they possess several drawbacks. Herein, we have reviewed new efforts leading to the development of novel reactivators and proposition of new promising strategies to design novel and effective antidotes. Structure-activity relationships and biological activities of recently proposed acetylcholinesterase reactivators are discussed and summarized. Among further modifications of known oximes, the main attention has been paid to dual binding site ligands of AChE as the current mainstream strategy. We have also discussed new chemical entities as potential replacement of oxime functional group.

A series of cholinesterase inhibitors acting as dual binding site heterodimers for the management of Alzheimer’s disease were developed. The series of 7-methoxytacrine (7-MEOTA)-amantadine ureas (11–17) was designed, prepared evaluated in vitro towards human acetyl/butyryl cholinesterase (hAChE, hBChE) and compared with the series of 7-MEOTA-amantadine thioureas (4–10). The heterodimers have different length of linkers combining 7-MEOTA and amantadine moieties. In comparison with 7-MEOTA, the newly synthesized compounds were better inhibitors of both cholinesterases. The urea analogues did not have the anticipated benefit of increased inhibitory activity and have comparable IC50 values with thiourea derivatives.

A new gene expression system was developed in Rhodobacter sphaeroides, replacing a pRK415-based system used previously. The broad host-range IPTG-inducible plasmid pIND4 was used to create the plasmid pIND4-RC1 for expression of the puhA and pufQBALMX genes, encoding the reaction centre (RC) and light-harvesting complex 1 (LH1) proteins. The strain R. sphaeroides ΔRCLH was used to make a knockout of the rshI restriction endonuclease gene, enabling electroporation of DNA into the bacterium; a subsequent knockout of ppsR was made, creating the strain R. sphaeroides RCx lacking this oxygen-sensing repressor of the photosynthesis gene cluster. Using pIND4-RC1, LH1 levels were increased by a factor of about 8 over pRS1 per cell in cultures grown semi-aerobically. In addition, the ppsR knockout allowed for photosynthetic pigment-protein complex synthesis in the presence of high concentrations of molecular oxygen; here, LH1 levels per cell increased by 20 % when grown under high aeration conditions. A new medium (called RLB) is the E. coli medium LB supplemented with MgCl2 and CaCl2, which was found to increase growth rates and final cell culture densities, with an increase of 30 % of LH1 per cell detected in R. sphaeroides RCx(pIND4-RC1) grown in RLB versus LB medium. Furthermore, cell density was about three times greater in RLB compared to semi-aerobic conditions. The combination of all the modifications resulted in an increase of LH1 and RC per mL of culture volume by approximately 35-fold, and a decrease in the length of culture incubation time from about 5 days to ~36 h.

10-Methylacridinium iodide (methylacridinium; MA) is an inhibitor of cholinesterases. Inhibitors of acetylcholinesterase (AChE) are used in the treatment of myasthenia gravis, Alzheimer's disease, and in the prophylaxis of poisoning with organophosphates. Using spectrophotometric Ellman's method at 436 nm and commercial enzymes we found that MA inhibits AChE by binding with relatively high potency to the peripheral anionic site (IC(50) = 1.68 +/- 0.14 1M; human recombinant AChE) and equally to its inhibition of butyrylcholinesterase (BuChE; IC(50) = 3.54 +/- 0.27 1M; BuChE from human serum). MA also inhibits the binding of [(3)H]N-methylscopolamine to the muscarinic M2 receptor subtype, possibly in an allosteric manner (IC(50) = 1.90 1M). Functional effects on both the enzyme and the receptor could be observed in contractile studies on the isolated rat bladder. The ability of MA to cross the blood-brain barrier (log P = -0.32; polar surface area 3.88) provides prerequisites for a potential use of the drug in the treatment of neural disorders.

New acetylcholinesterase reactivators with either a (E) or (Z)-but-2-ene connecting linker were recently prepared. The purity of the compounds was checked by HPLC and was found to be sufficient for in-vitro screening. All the discussed bispyridinium reactivators were analyzed by reversed-phase high performance liquid chromatography (RP-HPLC) to measure lipophilicity. The procedure was performed under isocratic conditions with methanol as organic modifier in the mobile phase using an end-capped non-polar C(18) stationary phase RP column. Relationships between the lipophilicity (logarithm of the RP-HPLC capacity factor, log k) and chemical structures of the studied compounds are discussed. Lipophilicity was different for the (E) and (Z) compounds and varied among the compounds in each of these groups. The lipophilicity differences also indicated an apparent influence of intramolecular interactions. Lipophilicity calculations (log P/Clog P) by means of commonly used software were not successful due to the presence of quaternary nitrogen atoms in the molecules of the reactivators.

Oximes in combination with atropine, are an integral part of the treatment of acute intoxications with organophosphorus insecticides or with the nerve agents such as tabun, sarin, soman, cyclosarin or VX. Organophosphorus compounds are extremely potent inhibitors of the enzyme acetylcholinesterase (AChE, 3.1.1.7). The pharmacological action of oximes is multiple: they are able to reactivate the inhibited AChE, but they affect acetylcholine release in peripheral and central cholinergic synapses, allosterically modulate the muscarinic receptors in peripheral and central synapses, and influence the nicotinic receptor-associated ion-channels. In our study, we have determined the acute toxicity of different structures of oximes after intramuscular application in mice. The acute toxicity of oximes is crucial for the assesment of a dose applied as a treatment for organophosphorus intoxications. We have tested 7 oximes of different structures (HS-6, K033, BI-6, MMB-4, K048, HI-6 and obidoxime ) and during our experiments we have observed the intoxication process including typical signs of intoxication, and times of death. K033 was the most toxic oxime with an LD50 of only 48 mg/kg, while the least toxic oxime - HI-6 - has an LD50 value of 671 mg/kg. All the oximes tested were of the bispyridinium type, with different length or shape of the connecting chain and positions of oxime groups at the pyridinium rings. All these structural features play an important role in biological activity of these compounds performed by their acute toxicity as well as by their reactivation potency.

Organophosphorus nerve agents inhibit the enzyme, acetylcholinesterase (AChE; EC 3.1.1.7). AChE reactivators (also known as oximes) are generally used for the reactivation of an inhibited enzyme.Two new AChE reactivators--K033 and K027--were tested for their in vitro reactivation of sarin-inhibited pig-brain AChE. Their reactivation potencies were compared with the commercially available AChE reactivators, pralidoxime, obidoxime, and HI-6.Of the oximes tested, the newly developed oxime K027 achieved the highest reactivation potency (100%; concentration of the oxime -10(-2) M). However, oxime HI-6 (33%) and obidoxime (23%) seem to be the best AChE reactivators for human relevant doses (10(-4) M and lower).For human relevant doses, newly developed oximes (K027 and K033) do not surpass the reactivation potency of the most promising oxime, HI-6.

Bacterial photosynthetic reaction centers (RCs) are promising materials for solar energy harvesting, due to their high internal quantum efficiency. However, applications of RCs in bio-photovoltaic devices so far show relatively low external power conversion efficiency, mainly due to low efficiency of the charge transfer to the electrode. Preferential orientation of RCs on an electrode’s surface can enhance the charge transfer rate to some extent. Yet, the results of direct coupling of RCs to an Au electrode, through cysteine residues from the H-subunit, revealed that direct electron transfer is not efficient. This work focuses on a different approach to achieve high charge transfer rate between an Au electrode and RC protein complexes by employing cytochrome c (Cyt c)\carboxylic acid-terminated linker molecules. This approach preferentially orients RCs with the primary donor site to the electrode. Furthermore, Cyt c can be considered as a conductive linker, while the charge transfer mechanism through carboxylic acid-terminated linker molecules is dominated by tunneling. The photochronoamperometric results for a two electrode cell setup indicated a 156 nA.cm-2 cathodic photocurrent density; the photocurrent was measured in an electrochemical cell with ubiquinone-10 (Q2) in the electrolyte. Negligible photocurrents were observed in the case of coupled RCs to the Au via cysteine residues on H-subunit, with only Cyt c in the electrolyte. These findings contribute to the design of highly efficient bio-photovoltaic devices.

Reaction centers (RCs) from natural photosynthetic cells are photoactive proteins, which generate electron-hole pairs in presence of light. In a new approach presented in this work, a solution of suspended RCs with mediators has been applied as the electrolyte to build electrochemical based photovoltaic (PV) devices. In this approach, the mediators transfer charges from the RCs to the electrodes (indirect charge transfer). Various metallic and wide bandgap semiconducting materials, including Carbon, Au, Indium Tin Oxide (ITO), SnO2, WO3, have been tested as the electrodes. Among all WO3, which is a semiconductor, have shown the largest photocurrent density with an amount of ∼5.1 μA/cm2. The results show that the material of the electrode can affect the rates of the reactions in the cell. Choosing an appropriate material for the electrode, the charge transfer from the mediators to the electrode would be rectified to achieve a large photocurrent.

The high quantum efficiency (~100%) in the bacterial photosynthetic reaction center (RC) has inspired research on the application of RCs to build protein based solar cells. Conventionally, applying RCs as the photosensitive layer on the surface of a carbon electrode has shown poor photocurrents in the cells. The low photocurrent is partly due to the weak absorption of light in the monolayer of RCs. Also, an Atomic Force Microscopy image of the electrode shows lots of defects on the immobilized RCs at the electrode surface. In this work, we have built a bio-photoelectrochemical cell in which the RCs are floating in the electrolyte instead of being attached to the surface of an electrode. Despite the simple structure of the cell, the photocurrent is significantly higher in the new cell compared to when RCs are attached to an electrode. The amplitude of current reached to ~40 nA for free floating RCs, about five times larger than that in the cell with attached RCs. The aging effect was studied in both cells in a course of a week. The lifetime of attached RCs on electrode surface was slightly better than solubilized RCs in the electrolyte. Also, it is found that the mechanism which governs the charge transfer from RCs to the electrodes is the same in both bio-photoelectrochemical cells.

Arylalkanoic acid derivatives exhibit a variety of biological effects. In the current publication some of new glycidic acid derivatives were prepared via the Darzens condensation. The synthetic approach, analytical and spectroscopic data of all newly synthesized compounds are presented. The prepared compounds were evaluated as potential inhibitors of arachidonic acid-induced platelet aggregation and their activity was compared with that of acetylsalicylic acid as the standard. (±)-Ethyl 3-{4-[(4-methoxyphenyl)sulfanyl]phenyl}-3-methyl-cis-oxirane-2-carboxylate (IC50 = 0.07 mmol L−1) and (±)-3-{4-[(4-methoxyphenyl)sulfanyl]phenyl}-3-methyl-cis-oxirane-2-carboxylic acid (IC50 = 0.06 mmol L−1) showed the highest antiplatelet activity against arachidonic acid-induced platelet aggregation comparable with the standard. Structure-activity relationships between the chemical structure, lipophilicity, and the antiplatelet activity of the evaluated compounds are discussed.

Organophosphorus pesticides parathion, chlorpyrifos, and malathion inhibit the enzyme acetylcholinesterase (AChE; EC 3.1.1.7) via phosphorylation of its active site. AChE reactivators and anticholinergics are compounds used as antidotes in the case of intoxication by these AChE inhibitors. In this work, chlorpyrifos, a representative member of this pesticide family, was used to inhibit the AChE activity of rat brain. The effect of twenty-one structurally different AChE reactivators was tested in vitro and subsequently, the relationship between their chemical structure and biological activity was outlined.

Nine potential AChE reactivators were synthesized using modification of currently known synthetic pathways. Their potency to reactivate AChE inhibited by cyclosarin nerve agent was tested in vitro. According to the previous results, 1,4-bis(2-hydroxyiminomethylpyridinium)butane dibromide seems to be the most potent AChE reactivator. The reactivation potency of these compounds depends on structural factors such as presence of quaternary nitrogens, length of the linking chain between both pyridinium rings, and position of the oxime moiety at the pyridinium ring.