Genes in food--why the furore?

Although unprecedented and perhaps unique in its irrationality, the recent furore over genetically modified (GM) food holds extremely important lessons for scientists. Some sections of the media undoubtedly bear a heavy responsibility for giving the expression 'GM' threatening connotations that are quite unwarranted. However, influential contributions to the hysteria have come from a surprising range of other sources, including some scientists. The research community has failed in its responsibility to society in three ways. Firstly, plant scientists did not appreciate that certain techniques (such as the use of antibiotic resistance genes as markers during plant transformation) would inevitably provoke public consternation. As a result, they took no steps to address such concerns. Secondly, researchers overlooked, minimized or in some cases simply dismissed the significance of public fears that they were 'interfering with Nature' or 'playing God'. Thirdly, plant breeders apparently saw no need to take pro-active measures with regard to the media and public in placing potential environmental and nutritional benefits of GM crops on the agenda in a positive fashion. Partly because of this failure, GM food is now firmly established in the public mind as wholly objectionable. One measure of how far we have travelled down that road is that it hardly matters any more whether objections are based on alleged environmental risks of cultivating GM crops or alleged toxicological hazards of eating them. 'Genetically modified organism', like 'radioactivity', has become an odious, generic shibboleth. Given that millions of people throughout the world are already benefiting from pharmaceuticals made by GM organisms, this is bizarre.     

Neuropeptides in the pineal gland?

Summary In an attempt to localize components of the renin angiotensinsystem in the pineal gland of rats, immunocytochemical studies using the PAP-technique were performed with antisera against angiotensin I, angiotensin II and angiotensinogen. The staining pattern thus obtained was not only the same for the three antisera, but was also identical to that shown for many other peptide-antisera in the literature. In those studies, the immunocytochemical staining had been ascribed to a distinct pineal cell population or to cell processes. However, by examining adjacent semithin and ultrathin sections by immunocytochemistry and electron microscopy, respectively, we could identify the extracellular perivascular compartment and its flocculent material as the site of staining.This unexpected localization and the observation of immunoreactivity of some preimmunsera in the same compartment as well as several additional findings and arguments are taken to suggest the likelihood of pseudopositive immunostaining, typical for the pineal gland.These studies were supported by the German Research Foundation within the SFB 90 Cardivasculäres System     

Is neurotensin in the brain involved in thermoregulation of the monkey?

Cannulae for intracerebroventricular (ICV) infusion were implanted stereotaxically in monkeys (Macaca fasicularis) maintained post-operatively in a primate restraint chair. During each experiment, a series of physiological measures was recorded simultaneously on a polygraph which included colonic temperature, vasomotor tone, heart rate, respiratory rate, and basal metabolism as reflected by O₂ uptake. The ICV infusion in a volume of 0.5 ml of neurotensin (NT) in doses ranging from 3–150 μg produced neither a statistically significant nor consistent change in body temperature or vasomotor response. Although the highest dose of 450 μg NT infused ICV caused an immediate bradycardia and a concomitant decline in metabolic and respiratory rates, an average decline in core temperature of 0.6°C and the accompanying cutaneous vasodilation often had a latency as long as 1.0 hr. In contrast to the typical hypothermia in this species following an ICV infusion of catecholamines, implicated in the central pathways underlying thermoregulation, NT failed to elicit a coordinated set of physiological responses for heat dissipation in the monkey. Therefore, it is unlikely that this tridecapeptide plays a role in the central mechanisms mediating the control of body temperature of this primate species.     

Is beauty in the eye of the beholder?

Theories of beauty were evaluated by requiring subjects to “evolve” a beautiful female face using a Genetic Algorithm. In this procedure, a computer program generated a small population of faces (first generation of phenotypes) from a set of random binary strings (genotypes). Genotypes specified the shapes and soft tissue anthropometrics of facial features. Each of the first generation of faces was rated by a subject (relative fitness measure) for beauty. The fittest genotypes then bred in proportion to their fitness, with crossover and mutation of the binary strings, to produce offspring which were again rated by the subject. This process continued until the most beautiful face, for that subject, was evolved. Forty Caucasian subjects (20 M, 20 F) were required to evolve their idealized beautiful female face using this procedure. The features and soft tissue anthropometrics of their final composites were compared to population norms. Also, the final composites, and different faces generated from the same data base, were rated for beauty by independent judges. The results support the conclusion that the concept of facial beauty is the result of sexual selection, and a beautiful female face has features and proportions indicative on high fertility.     

Which is the phyte in epiphyte?

The term “Epiphyte” has been used for a plant growing on any object, and also for any organism growing on a plant. Evidence from analogy, dictionaries, use and precedence supports the two interpretations equally. We recommend that “epiphyte” be used only for an organism growing on a plant.     

Plakophilins—hard work in the desmosome,recreation in the nucleus?

The linkage of the different types of cytoskeletal proteins to cell adhesion structures at the cytoplasmic membrane and the connection of these contact sites to corresponding sites of adjacent cells is a prerequisite for integrity and stability of cells and tissues. The structurally most prominent types of such cell-cell adhesion complexes are the desmosomes (maculae adhaerentes), which are found in all epithelia and certain non-epithelial tissues. As an element of the cytoskeleton, intermediate filaments are connected to the adhesive desmosomal transmembrane proteins by the cytoplasmic desmosomal plaque proteins. At least three different types of proteins are found in the desmosomal plaque, one of which is represented by the plakophilins, a recently described sub-family of sequence-related armadillo-repeat proteins. Consisting of three isoforms, plakophilins (plakophilin 1 to 3, PKP 1 to 3) are located in all desmosomes in a differentiation-dependent manner. While PKP 2 and PKP 3 are part of almost all desmosome-bearing cell types (PKP 2 except for differentiated cells of stratified epithelia and PKP 3 for hepatocytes and cardiomyocytes), PKP 1 is restricted to desmosomes of cells of stratified and complex epithelia. Besides the architectural function that plakophilins seem to fulfill in the desmosomes, at least PKP 1 and 2 are also localized in the nucleus independently of any differentiation-related processes and with an up to now enigmatic function in this compartment. In the following article we want to summarize the current knowledge concerning structure, function and regulation of the plakophilins that has been achieved during the last decade.