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Flavin mononucleotide (FMN) and flavin adenine dinucleotide (FAD) are utilized as coenzymes in many biochemical reduction-oxidation reactions owing to the ability of the tricyclic isoalloxazine ring system to employ the oxidized, radical and reduced state. We have analyzed the genome of Arabidopsis thaliana to establish an inventory of genes encoding flavin-dependent enzymes (flavoenzymes) as a basis to explore the range of flavin-dependent biochemical reactions that occur in this model plant. Expectedly, flavoenzymes catalyze many pivotal reactions in primary catabolism, which are connected to the degradation of basic metabolites, such as fatty and amino acids as well as carbohydrates and purines. On the other hand, flavoenzymes play diverse roles in anabolic reactions most notably the biosynthesis of amino acids as well as the biosynthesis of pyrimidines and sterols. Importantly, the role of flavoenzymes goes much beyond these basic reactions and extends into pathways that are equally crucial for plant life, for example the production of natural products. In this context, we outline the participation of flavoenzymes in the biosynthesis and maintenance of cofactors, coenzymes and accessory plant pigments (e. g. carotenoids) as well as phytohormones. Moreover, several multigene families have emerged as important components of plant immunity, for example the family of berberine bridge enzyme-like enzymes, flavin-dependent monooxygenases and NADPH oxidases. Furthermore, the versatility of flavoenzymes is highlighted by their role in reactions leading to tRNA-modifications, chromatin regulation and cellular redox homeostasis. The favorable photochemical properties of the flavin chromophore are exploited by photoreceptors to govern crucial processes of plant adaptation and development. Finally, a sequence- and structure-based approach was undertaken to gain insight into the catalytic role of uncharacterized flavoenzymes indicating their involvement in unknown biochemical reactions and pathways in A. thaliana., (Copyright © 2021 The Author(s). Published by Elsevier Ltd.. All rights reserved.)

Reconstructive surgery of the peripheral nerve has undergone major technical improvements over the last decades, leading to a significant improvement in the clinical outcome of surgery. Nonetheless, functional recovery remains suboptimal in the majority of patients after nerve repair surgery. In this review, we first discuss the molecular mechanisms involved in peripheral nerve injury and regeneration, with a special emphasis on the role of neurotrophic factors. We then identify five major challenges that currently exist in the clinical practice of nerve repair and their molecular basis. The first challenge is the slow rate of axonal outgrowth after peripheral nerve repair. The second problem is that of scar formation at the site of nerve injury, which is detrimental to functional recovery. As a third issue, we discuss the difficulty in assessing the degree of injury in closed traction lesions without total loss of continuity of the involved nerve elements. The fourth challenge is the problem of misrouting of regenerating axons. As a fifth and final issue we discuss the potential drawbacks of using sensory nerve grafts to support the regeneration of motoneurons. For all these challenges, solutions are likely to emerge from (a) a better understanding of their molecular basis and (b) the ability to influence these processes at a molecular level, possibly with the aid of viral vectors. We discuss how lentiviral vectors have been applied in the peripheral nerve to express neurotrophic factors and summarize both the advantages and drawbacks of this approach. Finally, we discuss how lentiviral vectors can be used to provide new, molecular neurobiology-based, approaches to address the clinical challenges described above.

Background: In 2000, the WHO African Region adopted a plan to accelerate efforts to lower measles mortality with the goal of decreasing the number of measles deaths to near zero. By June, 2003, 19 African countries had completed measles supplemental immunisation activities (SIA) in children aged 9 months to 14 years as part of a comprehensive measles-control strategy. We assessed the public-health impact of these control measures by use of available surveillance data., Methods: We calculated percentage decline in reported measles cases during 1-2 years after SIA, compared with 6 years before SIA. On the basis of data from 13 of the 19 countries, we assumed that the percentage decline in measles deaths equalled that in measles cases. We also examined data on routine and SIA measles vaccine coverage, measles case-based surveillance, and suspected measles outbreaks., Findings: Between 2000 and June, 2003, 82.1 million children were targeted for vaccination during initial SIA in 12 countries and follow-up SIA in seven countries. The average decline in the number of reported measles cases was 91%. In 17 of the 19 countries, measles case-based surveillance confirmed that transmission of measles virus, and therefore measles deaths, had been reduced to low or very low rates. The total estimated number of deaths averted in the year 2003 was 90,043. Between 2000 and 2003 in the African Region as a whole, we estimated that the percentage decline in annual measles deaths was around 20% (90,043 of 454,000)., Interpretation: The burden of measles in sub-Saharan Africa can be reduced to very low levels by means of appropriate strategies, resources, and personnel.

Background: Measles is the leading cause of vaccine-preventable death in Africa. Regional measles elimination is considered feasible using current vaccines and a series of WHO-recommended strategies. We aimed to interrupt transmission of measles, and to use case-based surveillance to show the effect of such interruption., Methods: In southern Africa from 1996, seven countries with a total population of approximately 70 million and with relatively high routine vaccination coverage implemented measles elimination strategies. In addition to routine measles immunisation at 9 months of age, these included nationwide catch-up campaigns among children aged 9 months to 14 years, then follow-up campaigns every 3-4 years among children aged 9-59 months, and the establishment of case-based measles surveillance with serological diagnostic confirmation., Results: Nearly 24 million children aged 9 months to 14 years were vaccinated, with overall vaccination coverage of 91%. Reported clinical measles cases declined from 60000 in 1996 to 117 laboratory-confirmed measles cases in 2000. Reported measles deaths declined from 166 in 1996 to zero in 2000. No increase in adverse events was noted after the measles vaccination campaign., Conclusion: A reduction in measles mortality and morbidity can be achieved in very low-income countries, in countries that split their vaccination campaigns by geographical area or by age-group of the target population, and where initial routine measles vaccination coverage among infants was <90%, even when prevalence of HIV/AIDS was extremely high. Continued high-level national commitment will be crucial to implementation and maintenance of proven strategies in southern Africa.

Short oligonucleotide probes have been linked to a solid support by simple electrostatic adsorption onto a positively charged surface film. Attachment was obtained by microfluidic application of unmodified oligonucleotides in distilled water onto amino-silanized glass. It has been demonstrated that an extremely stable monolayer of oligonucleotide is obtained by this method, at a density of about 10(11) molecules/mm(2), which approaches the limit expected for a two-dimensional closest-packed array. Application of oligonucleotide by adsorption is followed by capping with acetic anhydride in the vapor phase, and then capping with succinic anhydride in solution to form a surface with weak negative charge. The capping method has been successfully employed for microarray fabrication and for the analysis of single nucleotide polymorphisms in the k-ras gene. The data reveal that, subsequent to capping, the adsorptive association of oligonucleotide to the surface yields a probe layer which is capable of single nucleotide base mismatch discrimination and high apparent binding affinity., (Copyright 2001 Academic Press.)

The commentary is based on our results of biological aging research with the following findings: a loss of neurons cannot be found, the size of neurons and the number of synapses decrease with age, the various regions of brain react quite differently. Altogether, these results speak for "use it or lose it." However, the genetically determined decreased brain function during aging can only be inhibited, not permanently preserved.