What may be the markers of the male equivalent of polycystic ovary syndrome?

Polycystic ovary syndrome (PCOS), the most common endocrinopathy in women (with a prevalence of 5-10 %), is characterized by hormonal and metabolic imbalance. Complexity of symptoms of close relatives of women with PCOS and genetic autosomal trait initiated a hypothesis about the existence of a male equivalent of PCOS. Premature alopecia was suggested as one of the signs of a male phenotype of this syndrome. The present study investigated a group of 30 men, in which premature hair loss started before 30 years of age. In all patients, their hormonal profile was determined. It was possible to form two subgroups. The first one showed similar hormonal changes as women with PCOS, the other had either no anomalies in steroid spectrum or just only lower level of sexual hormones binding globulin (SHBG). Both subgroups did not differ in either BMI or age. In all men with premature alopecia insulin tolerance test was also carried out and the occurrence of allele 3 INS VNTR was investigated, which is one of the candidate genes for PCOS. The subgroup with hormonal changes resembling those of women with PCOS showed a significantly higher insulin resistance than the group without these changes. About one third of the premature balding men showed the combination of hormonal shifts and higher insulin resistance. This frequency corresponds to the prevalence of PCOS in women. There was no significant difference between the two subgroups in the occurrence of allele 3 INS VNTR.     

The nature of “internal sensations” of higher brain functions may be derived from the design rules for artificial machines that can produce them

Modeling various neuronal functions in search of emergent properties may achieve success when the gold standard of replicating the models in physical systems starts exhibiting some of these properties. Since very large number of functions can be modeled and need testing, we suggest an alternate method of examining higher brain functions: seeing them as internal sensations formed from their hypothetical basic units. Here, we explain the need to replicate the natural mechanism using electronic circuits, discuss some of the technical aspects and introduce some concepts for searching for properties of internal sensations evolving from them.     

What is a desirable statistical energy functions for proteins and how can it be obtained?

Can one obtain a physical energy function for proteins from statistical analysis of protein structures? A direct answer to this question is likely “no”. A less demanding question is whether one can produce a statistical energy function that has the desirable features of a physical-based energy function. Such a desirable energy function would be founded on a physical basis with few or no adjustable parameters, reproduce the known physical characters of amino acid residues, be mostly database independent and transferable, and, more importantly, reasonably accurate in various applications. In this review, we show how such a desirable energy function can be obtained via introducing a simple physical-based reference state called DRIRE (Distance-scaled, Finite, Ideal-gas Reference state).     

UV-induced changes in the skin: can they be repaired?

Abstract

The damaging effects of UVB light have been described previously and include a number of changes to multiple cell types. At previous meetings of this society, we have shown that Langerhans' cells are the most susceptible to UVB induced damage which can be shown as ultrastructural changes in dendrites, nucleus and cytoplasm by transmission electron microscopy. We have also shown that their patterns of migration from skin to regional lymph node and their ability to present antigens to autologous T cells have been profoundly altered by UVB irradiation.

The aim of this work was to establish if it was possible to reverse any of the damage done to Langerhans' cells by UVB exposure by topical application of a DNA repair enzyme such as T4N5 endonuclease. These experiments were undertaken in a sheep model that allowed collection of cells as they migrate from the skin. This allowed for a direct examination of the migration characteristics and ultrastructural features of all Langerhans' cells before, during, and for 2 weeks after exposure to a single dose of UVB.

Results obtained from this project indicate that treatment by topical application of DNA repair enzyme immediately after UVB irradiation may restore a number of normal immune parameters associated with the structure and function of migrating Langerhans' cells. It appears that there is a dose related correction of the increased tempo of cell migration and some improvements in the number of ultrastructurally damaged Langerhans' cells have also been associated with application of higher doses of DNA repair enzyme. These preliminary findings indicate that some potential therapeutic benefits are associated with the use of such agents in reversing the immunological damage caused by exposure to erythemal doses of UVB light.     

UV-induced changes in the skin: can they be repaired?

The damaging effects of UVB light have been described previously and include a number of changes to multiple cell types. At previous meetings of this society, we have shown that Langerhans' cells are the most susceptible to UVB induced damage which can be shown as ultrastructural changes in dendrites, nucleus and cytoplasm by transmission electron microscopy. We have also shown that their patterns of migration from skin to regional lymph node and their ability to present antigens to autologous T cells have been profoundly altered by UVB irradiation. The aim of this work was to establish if it was possible to reverse any of the damage done to Langerhans' cells by UVB exposure by topical application of a DNA repair enzyme such as T4N5 endonuclease. These experiments were undertaken in a sheep model that allowed collection of cells as they migrate from the skin. This allowed for a direct examination of the migration characteristics and ultrastructural features of all Langerhans' cells before, during, and for 2 weeks after exposure to a single dose of UVB. Results obtained from this project indicate that treatment by topical application of DNA repair enzyme immediately after UVB irradiation may restore a number of normal immune parameters associated with the structure and function of migrating Langerhans' cells. It appears that there is a dose related correction of the increased tempo of cell migration and some improvements in the number of ultrastructurally damaged Langerhans' cells have also been associated with application of higher doses of DNA repair enzyme. These preliminary findings indicate that some potential therapeutic benefits are associated with the use of such agents in reversing the immunological damage caused by exposure to erythemal doses of UVB light.     

Could plant hormones be the basis of maturation indices in Pinus radiata?

Maturation and phase change in woody plants are developmental processes at present poorly understood, especially from a physiological point of view. Maturation indices, such as phytohormones, could be used to understand more about the events that accompany the increase in the developmental state and to choose optimal conditions in order to improve forest programs and make them more profitable. In order to determine this putative index, the contents in abscisic acid-like substances (ABA-like), indole-3-acetic acid (IAA) and several cytokinins (Cks) were analysed in terminal and axillary buds of Pinus radiata trees with different developmental states to compare their phytohormonal status. An increase in the content of some zeatin-type (Z-type) Cks, and a decrease in isopentenyladenine-type (iP-type) Cks levels throughout maturation were shown both in terminal and axillary buds. This fact allowed us to consider the ratio iP-type/Z-type Cks, which decreased in parallel with the increasing developmental state of the tree, as a maturation index. According to the results, ABA-like compounds and IAA contents could not be considered as a maturation index in Pinus radiata, even though similar patterns were in fact found between the two kinds of buds.     

What is the biological basis of sensorimotor integration?

This Prospects presents the problems that must be solved by the vertebrate nervous system in the process of sensorimotor integration and motor control. The concepts of efference copy and inverse model are defined, and multiple biological mechanisms are described, including those that form the basis of integration, extrapolation, and comparison/cancellation operations. Open questions for future research include the biological basis of continuous and distributed versus modular control, and somatosensory-motor coordination.     

How can we improve tracking of transplanted tissue in the United States?

Currently an estimated two million tissues are distributed for transplantation annually. With increasing use of recovered tissue, clusters of transplant-transmitted infection have shown the difficulty of tracking tissues from an infected donor to the recipient. The challenge of tissue tracking to multiple transplant recipients was illustrated in a recent investigation of transmission of hepatitis C virus infection from a donor of organs and tissues. When a tissue bank issued a recall of the donated tissue, the Centers for Disease Control and Prevention was notified to assist public health authorities; the mean time to locate and notify the physicians who had transplanted the tissue was 13 days, while the mean time to notify, inform, and test the patients was 29 days. Lack of common coding and nomenclature was one of the key challenges in tracking tissue to the recipient. Some changes that could improve timeliness in the event of a recall includes: (1) standardized tissue nomenclature and coding through unique donor identifiers; (2) tissue traceability requirements using systems similar to that used for blood products; (3) a surveillance system for adverse events that provides feedback at the provider level.     

What can be observed in real time PCR and when does it show?

Journal of Mathematical Biology - Real time, or quantitative, PCR typically starts from a very low concentration of initial DNA strands. During iterations the numbers increase, first essentially by...     

What can phylogenetics tell us about speciation in the Cape flora?

The spectacular diversity of the Cape flora has promoted wide speculation on the evolutionary processes behind its origins, but until recently these ideas could not be tested rigorously due to the almost complete absence of a fossil record for the region. Now, molecular phylogenetic approaches, combined with analyses of ecological and biogeographical information, offer the potential to test key hypotheses about speciation of so-called Cape clades of flowering plants. We outline the main theories and how they might be tested by phylogenetic approaches. One conclusion is that population level studies of particular species complexes are now needed to complement the growing volume of phylogenetic information for Cape clades and to provide better understanding of mechanisms of population divergence in the Cape. Another is that comparisons between Cape and non-Cape clades are needed to confirm whether speciation is indeed faster in the Cape region. An alternative possibility, that extinction rates are lower, should also be considered in these comparisons. By virtue of the ongoing, coordinated efforts by a global team of botanists, the Cape is now uniquely placed for exploring the origins and assembly of a regional assemblage or biome.     

What can myosin VI do in cells?

The recently solved structure of the myosin VI motor demonstrates that the unique insert at the end of the motor is responsible for the reversal of the normal myosin directionality. A second class-specific insert near the nucleotide-binding pocket contributes to myosin VI's unique kinetic tuning, allowing it to function either as an actin-based transporter or as an anchoring protein. Recent biochemical and biophysical studies have shown that the native molecule can form dimers upon clustering, and cell biological studies have demonstrated that it clearly does play both transport and anchoring roles in cells. These mechanistic insights allow us to speculate on how unusual aspects of myosin VI structure and function allow it to fill unique niches in cells.