Neuropeptide Y: its diversity and the apparent contradictoriness of its functions. An analysis of its possible mediated effects

The review of NPY functions summarizes so fare accumulated data of its physiological effects. The estimation of heterogeneity of NPY receptors in responding reactions is made. The analysis of possible direct and indirect NPY effects is performed including cascade mechanism of other peptides releasing. Peptide cascade regulation modeling software created on database programming language Visual FoxPro 5.0 allows to trace several induction steps and estimate possible contribution of each peptide into final spectrum of biological activity.     

Enzymatic transamination: the history of its discovery and milestones in the study of its mechanism and biological role (on the 50th anniversary of its discovery)

The history of discovery of enzymic transamination is described. A survey presents the crucial steps of the investigations of the catalytic mechanisms and metabolic functions of transaminases.     

Influence of the Aptamer Grafting on its Conformation and its Interaction with Targeted Protein

Plasmonics - Aptamers are functional small single-strand oligonucleotides (DNA) that show high affinity to their target molecules such as proteins or small analytes through the formation of...     

Metabolism and the problem of its universalization

Metabolism tends to be conceived either as an operationally closed network of production of components or as an autonomous apparatus of management of energy flows. Taking up some recent ideas that connect the concept of autonomy with thermodynamic requirements, we move further to defend the hypothesis that there must be a deep intertwinement between the relational-constructive logic of a basic biological system and the logic of its thermodynamic implementation. Hence, we propose that metabolism should be universally defined as the recursive self-maintenance of controls upon the energy flows necessary for the physical realization of a component production system operationally closed. Finally, being critical with some claims of the so-called 'strong' artificial life approach, we try to show that present 'computational metabolisms' are necessarily different in their structure and functioning from any real metabolic system, due to the distinct type of causal relations and mechanisms which are respectively established in them.     

Torsion of the Testis and its Appendages

In a survey of 101 cases with an index diagnosis of torsion of the testis or its appendage, there were 86 instances of torsion of the testis and 14 of torsion of the hydatid of Morgagni. In 38 of the patients with testicular torsion there were one or more “warning” attacks of pain and swelling, due to torsion which became spontaneously untwisted. In 19 cases operative fixation was performed because of this warning history, and all the testes were preserved. In the other 19 the testes were not explored until the patient came in with a severe “classical” episode of torsion: seven of these testicles were lost from gangrene or delayed atrophy.In 31 cases torsion resulted in failure to save the testis. Of these, 20 were misdiagnosed and treated initially as epididymo-orchitis, despite there being no evidence of a urinary tract infection. There is no excuse for not exploring any actuely inflammed testicle which is unaccompanied by definite evidence of urinary or urethral infection.     

From the conception of the PRINS to its coronation

As a non-isotopic molecular cytogenetic technique, the primed in situ (PRINS) labelling reaction represents a major technological progress achieved in the past decade. It has become a routine technique for the microscopic visualization of specific DNA sequences in cells and nuclei and constitutes a good alternative to the fluorescence in situ hybridization (FISH) procedure. Among the multiple advantages that characterize the PRINS technique, specificity, rapidity, reliability, reproducibility, and cost-effectiveness can be mentioned. PRINS can be in addition associated with other techniques like FISH, indirect immunofluorescence, and nick translation. The most recent developments show the great potential of this technique. Now PRINS can be used to study single-copy genes and, consequently, can be routinely used to investigate deletions associated with microdeletion syndromes. Therefore, the PRINS technique has the potential to become a widely used molecular cytogenetic tool in clinics and research. This short review presents how the PRINS technique contributed to further the understanding of biological phenomena and describes the different possibilities and applications of the PRINS method in several biological and clinical fields (pre-implantation testing, prenatal, constitutional and oncologic genetic diagnosis).     

Laser light: its nature and its action on the eye.

Lasers produce a coherent, focused, monochromatic, high-energy form of light. Because laser surgery is more versatile and precise and is freer of complications than conventional surgery it has become widely accepted in ophthalmology over the past 10 years. Applications range from routine procedures in the fundus to recent, more delicate interventions in the cornea. The argon laser is the most widely used to treat extrafoveal chorioretinal diseases such as age-related macular degeneration and diabetic retinopathy; it has also been used successfully to treat glaucoma by iridectomy or trabeculoplasty. The krypton red laser is the argon laser''s counterpart in the treatment of subfoveal and pigment-epithelium-related diseases. Posterior capsulotomy is the most widespread and successful intervention with the neodymium:yttrium-aluminum-garnet crystal laser; this laser is also used to cut vitreous traction bands and is increasingly used in iridectomy. Although the use of the excimer laser in corneal surgery is still largely investigational it has been shown to produce precise cuts in corneal layers for the correction of myopia or astigmatism. The variable-wavelength dye laser, capable of reaching a specific level in the retina or choroid, has offered exciting new developments, and it promises to soon be part of the ophthalmologist''s armamentarium in the treatment of eye disease.     

How the white tiger lost its color,but kept its stripes

<正>The fantastic range of animal coloration is produced by pigment particles of colored material or microscopic structures in scales,bristles or feathers that give rise to brilliant iridescent colors.In mammals,except for a few exceptions involving nano-or micro-scale structural color(e.g.,the blue faces of male baboons),fur color is determined by the pigment melanin.Melanin is synthesized and stored in     

Role of ATP on the interaction of alpha-crystallin with its substrates and its implications for the molecular chaperone function

ATP plays a significant role in the function of molecular chaperones of the large heat shock protein families. However, its role in the functions of chaperones of the small heat shock protein families is not understood very well. We report here a study on the role of ATP on the structure and function of the major eye lens chaperone alpha-crystallin. Our in vitro study shows that at physiological temperature, ATP induces the association of alpha-crystallin with substrate proteins. The association process is reversible and low affinity in nature with unit binding stoichiometry. 4,4'-Dianilino-1,1'-binaphthyl-5,5-disulfonic acid, dipotassium salt, binding studies show that ATP induces the exposure of additional hydrophobic sites on alpha-crystallin, but no appreciable enhancement of the same was observed for the substrate protein gamma-crystallin or carbonic anhydrase. An equilibrium unfolding study reveals that ATP at 3 mgm concentration stabilizes the alpha-crystallin structure by 4.5 kJ/mol. The compactness induced by ATP makes it more resistant to tryptic cleavage. ATP-induced association of chaperone alpha-crystallin with substrate enhanced its aggregation prevention ability and also enhanced the refolding yield of lactate dehydrogenase from the unfolded state. Our results suggest that the binding of ATP to alpha-crystallin and not its hydrolysis is required for all these effects, as replacement of ATP by its nonhydrolyzable analogue adenosine-5'-O-(3-thiotriphosphate), tetralithium salt, reproduced all the results faithfully. The implication of the ATP-induced reversible protein-protein association at physiological temperatures on the functional role of alpha-crystallin in vivo is discussed.