Metabolic surgery: Quo Vadis?

The impact of bariatric surgery beyond its effect on weight loss has entailed a change in the way of regarding it. The term metabolic surgery has become more popular to designate those interventions that aim at resolving diseases that have been traditionally considered as of exclusive medical management, such as type 2 diabetes mellitus (T2D). Recommendations for metabolic surgery have been largely addressed and discussed in worldwide meetings, but no definitive consensus has been reached yet. Rates of diabetes remission after metabolic surgery have been one of the most debated hot topics, with heterogeneity being a current concern. This review aims to identify and clarify controversies regarding metabolic surgery, by focusing on a critical analysis of T2D remission rates achieved with different bariatric procedures, and using different criteria for its definition. Indications for metabolic surgery for patients with T2D who are not morbidly obese are also discussed.     

Proteomics and the dynamic plasma membrane: Quo Vadis?

Quo Vadis: where are you going? Advances in MS-based proteomics have enabled research to move from obtaining the basic protein inventory of cells and organelles to the ability of monitoring their dynamics, including changes in abundance, location and various PTMs. In this respect, the cellular plasma membrane is of particular interest, by not only serving as a barrier between the "cell interior" and the external environment, but moreover by organizing and clustering essential components to enable dynamic responses to internal and external stimuli. Defining and characterizing the dynamic plasma membrane proteome is crucial for understanding fundamental biological processes, disease mechanisms and for finding drug targets. Protein identification, characterization of dynamic PTMs and protein-ligand interactions, and determination of transient changes in protein expression and composition are among the challenges in functional proteomic studies of the plasma membrane. We review the recent progress in MS-based plasma membrane proteomics by presenting key examples from eukaryotic systems, including mammals, yeast and plants. We highlight the importance of enrichment and quantification technologies required for detailed functional and comparative analysis of the dynamic plasma membrane proteome.     

Quo Vadis Brain Repair? A Long Axonal Journey in the Adult CNS

Recently in Nature Neuroscience, Gaillard et al. (2007) study axonal projections from embryonic cortical explants grafted into acutely damaged adult motor cortex. After attempting to rule out fusion of donor tissue with pre-existing host circuitry, the authors report robust long-distance donor axonal projections and synaptic integration into target regions appropriate for the motor system.     

Chrysanthemum Biotechnology: Quo vadis?

Chrysanthemum is globally the second most important ornamental in terms of socioeconomic importance. Even though the vast range of flower colors, shapes and forms were initially created using conventional and mutation breeding, transgenic strategies are now more frequently used with Agrobacterium-mediated transformation being the most popular form of introducing foreign genes into chrysanthemums. Even so, transformation efficiency remains dependent on cultivar and regeneration procedure. Transgenic molecular breeding has seen the introduction of important traits such as novel flower color and form and plant architecture, prolonged cut-flower vase-life, resistance to biotic stresses such as viruses/viroids, pathogens and insects. However, chimerism and transgene silencing continue to be limiting factors. Transgenic strategies, despite opening up new avenues for creating new cultivars with improved agronomic and horticultural traits, may be limited due to the risk of transgenic pollen escaping into the wild.     

Glycosylation diseases: Quo vadis?

About 250 to 500 glycogenes (genes that are directly involved in glycan assembly) are in the human genome representing about 1–2% of the total genome. Over 40 human congenital diseases associated with glycogene mutations have been described to date. It is almost certain that the causative glycogene mutations for many more congenital diseases remain to be discovered. Some glycogenes are involved in the synthesis of only a specific protein and/or a specific class of glycan whereas others play a role in the biosynthesis of more than one glycan class. Mutations in the latter type of glycogene result in complex clinical phenotypes that present difficult diagnostic problems to the clinician. In order to understand in biochemical terms the clinical signs and symptoms of a patient with a glycogene mutation, one must understand how the glycogene works. That requires, first of all, determination of the target protein or proteins of the glycogene followed by an understanding of the role, if any, of the glycogene-dependent glycan in the functions of the protein. Many glycogenes act on thousands of glycoproteins. There are unfortunately no general methods to identify all the potentially large number of glycogene target proteins and which of these proteins are responsible for the mutant phenotypes. Whereas biochemical methods have been highly successful in the discovery of glycogenes responsible for many congenital diseases, it has more recently been necessary to use other methods such as homozygosity mapping. Accurate diagnosis of many recently discovered diseases has become difficult and new diagnostic procedures must be developed. Last but not least is the lack of effective treatment for most of these children and of animal models that can be used to test new therapies.     

Adenosine Receptor Classification: Quo Vadimus?

Abstract

Considerable progress has been made in our understanding of the diversity of adenosine receptors during the last decade, with the cloning of the orphan receptors RDC7 and RDC8 (1), and their subsequent characterisation as canine A₁ and A₂ receptors respectively (2,3), in the late 1980s. The principal objective of this review is to produce an integrated view of adenosine receptor classification, using the important observations from studies of molecular biology, receptor binding characteristics and functional pharmacology.     

Quo vadis porphyrin chemistry?

This review summarizes recent developments in the area of porphyrin chemistry in the direction of biological applications. Novel synthetic methodologies are reviewed for porphyrin synthesis, porphyrin analog synthesis, stable porphyrinogens -- calixpyrroles, expanded porphyrins. Unique biological properties of those compounds are desribed with focus on photodynamic therapy (PDT) and molecular recognition properties. Special attentions given to metalloporphyrins with potential to affect heme degradation and CO formation.     

Quo vadis plant hormone analysis?

Plant hormones act as chemical messengers in the regulation of myriads of physiological processes that occur in plants. To date, nine groups of plant hormones have been identified and more will probably be discovered. Furthermore, members of each group may participate in the regulation of physiological responses in planta both alone and in concert with members of either the same group or other groups. The ideal way to study biochemical processes involving these signalling molecules is ‘hormone profiling’, i.e. quantification of not only the hormones themselves, but also their biosynthetic precursors and metabolites in plant tissues. However, this is highly challenging since trace amounts of all of these substances are present in highly complex plant matrices. Here, we review advances, current trends and future perspectives in the analysis of all currently known plant hormones and the associated problems of extracting them from plant tissues and separating them from the numerous potentially interfering compounds.     

Neural stem cells and neuro‐oncology: Quo vadis?

Conventionally, gliomas are assumed to arise via transformation of an intraparenchymal glial cell that forms a mass that then expands centrifugally, eventually invading surrounding tissues. We propose an alternative model in which gliomas arise via initiation and promotion of cells within the brain's subependymal layer or subventricular zone, the source of a recently characterized pool of neural cells with the properties of self-renewal and multipotentiality (i.e., stem cells) that persists into adulthood. In this model, the particular histological subtype of glioma would represent the effects of temporal and spatial environmental influences rather than the particular cell of origin and the disease's centrifugal point would be the subependymal layer. The implications of such a model are discussed.