The search for the ideal biocatalyst.

While the use of enzymes as biocatalysts to assist in the industrial manufacture of fine chemicals and pharmaceuticals has enormous potential, application is frequently limited by evolution-led catalyst traits. The advent of designer biocatalysts, produced by informed selection and mutation through recombinant DNA technology, enables production of process-compatible enzymes. However, to fully realize the potential of designer enzymes in industrial applications, it will be necessary to tailor catalyst properties so that they are optimal not only for a given reaction but also in the context of the industrial process in which the enzyme is applied.     

In search of the ideal nose

The proportions of the so-called ideal nasal shape and the operations designed to achieve this have been the subject of innumerable papers. The vast majority of patients in the authors' practices desire a more refined version of the nose and do not want the so-called nosejob look with ideal proportions. A total of 2930 cosmetic rhinoplasties performed over the past 20 years, based on the philosophy of refining the more unrefined features of the nose according to the patients' wishes, have been reviewed, and almost all of these patients were satisfied with the long-term shape of their nose, even though in many cases these noses would be considered less than ideal by some of the newer criteria.     

In search of the ideal female umbilicus

The umbilicus is essential to the aesthetic appearance of the abdomen. However, little research exists on what characterizes an aesthetically pleasing umbilicus. Often, the plastic surgeon is called on to reconstruct the umbilicus. Although a variety of reconstructive methods are available, no real standards define the appearance of an aesthetically pleasing umbilicus. To ascertain the characteristics of an aesthetically pleasing umbilicus, a photographic analysis was undertaken using 147 female participants between the ages of 18 and 62 years. Each subject's age, height, and weight were recorded. Photographs of each participant's umbilicus were then taken from 30 cm and 50 cm away. The photographs were reviewed by the authors, and each umbilicus was categorized on the basis of size, shape, hooding, or protrusion. The photographs were then reviewed by a panel and given a score between 1 and 10 to rate attractiveness. Using linear regression analysis, the effects of body mass index, shape, hooding, and umbilical protrusion on attractiveness were assessed. The T- or vertically shaped umbilicus with superior hooding consistently scored the highest in aesthetic appeal, whereas the presence of any degree of protrusion and a horizontal orientation or distorted shape detracted from the score. Those with a large umbilicus tended to score consistently lower than those with a smaller configuration. A desirable goal in umbilical reconstruction is, thus, to create a small T or vertically oriented umbilicus with the addition of a superior hood or shelf.     

Immunomarkers in gynecologic cytology: the search for the ideal 'biomolecular Papanicolaou test'

Harnessing the knowledge we have gained on the cell cycle disruption caused by human papillomaviruses (HPV) will likely lead to improved screening modalities for cervical cancer and its precursors. An easily applied biomarker that has high specificity and sensitivity would represent an attractive alternative or complement to cytology and HPV testing. To date, a number of promising markers have been investigated. These include p16(INK4A), MIB-1, BD-ProEx C, and L1. Newer possibilities involve a variety of gene products associated with aberrations of chromosome 3q, such as telomerase, p63, and PIK3CA, as well the combination of biomarkers such as p16(INK4A) and MIB-1 in the same assay. Although none of them has yet been incorporated into screening algorithms or found its way into routine practice, their performance characteristics remain a focus of current investigations. This review summarizes what we know and where we hope to go in translating basic pathobiology into clinical practice.     

A search for the ideal type I β-turn

In 1968 C. Venkatachalam (Biopolymers, Vol. 6, pp. 1425–1436) predicted the ideal forms of β-turns (type I, type II, etc.) based entirely on theoretical calculations. Subsequently, over a thousand x-ray structures of different globular proteins have been analyzed, with results suggesting that the most important form among the hairpin conformers is the type I β-turn. For the latter type of hairpin conformation, the original computations had predicted ϕ_i+1 = −60°, ψ_i+1 = −30°, ϕ_i+2 = −90°, and ψ_i+2 = 0° as backbone torsion angle values, and these have been used from that time as reference values for the identification of the type I β-turn. However, it has never been clarified whether these “ideal” backbone torsion angle values exist in real structures, or whether these torsion angles are only “theoretical values.” Using the most recent release of the Protein Data Bank (1994), a survey has been made to assign amino acid pairs that approach the ideal form of the type I β-turn. The analysis resulted in four sequences where the deviation from ideal values for any main-chain torsion angles was less than 2°. In order to determine whether such a backbone fold is possible only in proteins owing to fortuitous cooperation of different folding effects, or whether it occurs even in short peptides, various attempts have been made to design the optimal amino acid sequence. Such a peptide model compound adopting precisely the predicted torsion angle values [ϕ_i+1 = −60°, ψ_i+1 = −30°, ϕ_i+2 = −90°, and ψ_i+2 = 0°] could provide valuable information. The solid state conformation of cyclo[(δ) Ava-Gly-Pro-Thr (O¹Bu)-Gly] reported herein, incorporating the -Pro-Thr- subunit, yields values suggesting that the “ideal” type I β-turn is even possible for a peptide where there are no major environmental effects present. © 1996 John Wiley & Sons, Inc.     

Migration dynamics for the ideal free distribution

This article verifies that the ideal free distribution (IFD) is evolutionarily stable, provided the payoff in each patch decreases with an increasing number of individuals. General frequency-dependent models of migratory dynamics that differ in the degree of animal omniscience are then developed. These models do not exclude migration at the IFD where balanced dispersal emerges. It is shown that the population distribution converges to the IFD even when animals are nonideal (i.e., they do not know the quality of all patches). In particular, the IFD emerges when animals never migrate from patches with a higher payoff to patches with a lower payoff and when some animals always migrate to the best patch. It is shown that some random migration does not necessarily lead to undermatching, provided migration occurs at the IFD. The effect of population dynamics on the IFD (and vice versa) is analyzed. Without any migration, it is shown that population dynamics alone drive the population distribution to the IFD. If animal migration tends (for each fixed population size) to the IFD, then the combined migration-population dynamics evolve to the population IFD independent of the two timescales (i.e., behavioral vs. population).     

Searching for the ideal forms of proteins

A modification of the Structure Alignment Program (SAP), combined with a novel automatic method for the definition of structural elements, correctly identified the core folds of a variety of small beta/alpha proteins when compared with a series of ideal architectures. This approach opens the possibility of not just determining whether one structure is like another, but given a range of ideal forms, determining what the protein is. Preliminary studies have shown it to work equally well on the all alpha-class and the all-beta class of protein, each of which have corresponding ideal forms. Given the speed of the algorithm, it will be possible to compare all of these against the Protein Structure Database and determine the extent to which the current ideal forms can account for the variety of protein structure. Analysis of the remainder should provide a base for the development of further forms.     

二十一世纪的理想食品─螺旋藻

本文全面综述了螺旋藻的营养价值、保健功效、药用价值及其在水产养殖方面的应用,并展望了其开发前景。