Immunohistologic studies of lymphomas. New methodology yields new information and poses new problems.

There occur tumors corresponding to almost all kinds of normal tissues, and clearly our classification of tumors will run parallel with our classification of normal tissues.     

人类起源研究的新进展和新问题

人类起源研究的新进展和新问题吴汝康（中国科学院古脊椎动物与古人类研究所,北京１０００４４）人类起源的研究近年来有了很大的进展,与人类起源有关的猿类化石和各种人类化石有了很多新的发现,分布的范围扩大了,研究的方法从宏观到微观,从形态到生态,更为多样化,...     

未来的保育议题

未来的保育议题黄生（国立台湾师范大学生物系,台北１１７１８）要回答为什么生物歧异度（ｂｉｏｌｏｇｉｃａｌｄｉｖｅｒｓｉｔｙ）如此快速的、世界性的衰退这个问题其实并不困难。生物社会被破坏及物种趋于灭绝,主要是由于有些人从中获利,获利的可能是当地人,外地...     

Obesity and time preference: the health consequences of discounting the future

Much focus has been placed on the obesity epidemic due to its high prevalence and the costs it imposes on society. Using 2004 data from the Roper Center, complemented with 2003 data from the Behavioural Risk Factor Surveillance System, this study analyses the possible effect that time preference has on health in the United States, as measured by the body mass index. After controlling for a variety of covariates and correcting for potential selectivity, some evidence of a positive association between time preference for the present and the body mass index can be found, particularly for males. Research in this area has policy implications in terms of creating incentives for those who lack self-control through the use of pre-commitment devices. Measures addressing self-control issues may be more effective in reducing the rising obesity rates across the world.     

New issues and future legislation on biosafety.

The current debate on gene technology in Europe is reviewed with particular emphasis on the role of EFB and science in general. From this debate important lessons have been learned by scientists, industrial companies, legislators, parliamentarians and interest organisations. This gives confidence that the continued debate will eventually lead to public acceptance of gene technology even in the food area.     

Psychophysics of sweet and fat perception in obesity: problems, solutions and new perspectives

Psychophysical comparisons seem to show that obese individuals experience normal sweet and fat sensations, they like sweetness the same or less, but like fat more than the non-obese do. These psychophysical comparisons have been made using scales (visual analogue or category) that assume intensity labels (e.g. extremely) which denote the same absolute perceived intensity to all. In reality, the perceived intensities denoted by labels vary because they depend on experiences with the substances to be judged. This variation makes comparisons invalid. Valid comparisons can be made by asking the subjects to rate their sensory/hedonic experiences in contexts that are not related to the specific experiences of interest. Using this methodology, we present the evidence that the sensory and hedonic properties of sweet and fat vary with body mass index. The obese live in different orosensory and orohedonic worlds than do the non-obese; the obese experience reduced sweetness, which probably intensifies fat sensations, and the obese like both sweet and fat more than the non-obese do. Genetic variation as well as taste pathology contribute to these results. These psychophysical advances will impact experimental as well as clinical studies of obesity and other eating disorders.     

Postmarketing surveillance of adverse drug reactions: problems and solutions.

The surveillance of adverse drug reactions (ADRs) is an unqualified must. However, the optimal means of surveillance is still unclear. Although anecdotal reports are the backbone of an ADR surveillance system, they are not enough. The pharmaceutical industry, academics and regulatory agencies need to expand their efforts in monitoring ADRs. The author discusses the various techniques for counting and evaluating adverse reactions and suggests ways in which the system could be improved.     

Enzymatic conversions of polar lipids. Principles, problems and solutions

This text provides a brief overview of the principles of enzymatic lipid conversion and some recent advances in the enzymatic conversion of glycerophospholipids and galactolipids. Lipases and phospholipases are used to exchange fatty acids or the polar group in the lipids. The reactions can be carried out either as hydrolysis–esterification sequences or as one-step transferase reactions. The scope and limitations of the different methods are discussed.     

The future of new oral antibiotics including the quinolones.

It is estimated that more than 110 million dollars'' worth of oral antibiotics will have been sold in Canada in 1987. In the next few years several new oral antimicrobial agents will reach the market, including beta-lactamase inhibitors, cephalosporins, monobactams, erythromycins and quinolones. Most of these new agents have a broader spectrum of antibacterial activity than the presently available oral antibiotics. A few have a longer half-life and can be administered once a day. The new oral drugs, especially the quinolones and possibly beta-lactams, will now be used to treat infections that in the past could be treated only parenterally. Exacerbations of pulmonary infections due to Pseudomonas aeruginosa in cystic fibrosis can now be successfully treated at home with the new quinolones. Osteomyelitis, arthritis, pneumonia and pyelonephritis will most likely be treated at home in the future. In severe infections patients will be admitted to hospital for short courses of parenteral therapy, followed by oral treatment. If used appropriately the new oral agents may lead to new approaches to the treatment of infectious diseases.     

Hydrodynamic multibead modeling: problems, pitfalls and solutions. 3. Comparison of new approaches for improved predictions of translational properties

Modeling simple and complex biopolymers in solution requires the shapes of these molecules to be approximated by bead modeling procedures, primarily for the prediction of hydrodynamic and scattering quantities. Though several bead modeling strategies (strict, shell and filling models) and a variety of computer programs (preferably the HYDRO suite by the García de la Torre group) are available, several subtle questions remain to be answered, in particular concerning the appropriate volume correction for intrinsic viscosity computations. In this context, various versions of the HYDRO programs and different types of volume corrections, as well as the novel, alternative program ZENO of the Mansfield group, were applied to a plethora of thoroughly designed multibead models of spherical, ellipsoidal, cylindrical and prismatic shapes. A critical comparison of the results obtained reveals a variety of new aspects, useful for many future applications. Among these, application of our recently suggested “reduced volume correction” (RVC) together with specially adapted HYDRO versions and use of ZENO turned out to be highly effective, in particular when aiming at filling model strategies and using high bead numbers, a domain not fully supported by the recent HYDRO++ versions. By our approaches, the values of translational properties (diffusion coefficients, D, and intrinsic viscosities, [η]) of all multibead models applied were anticipated correctly.     

Opinions of Obesity Experts on the Causes and Treatment of Obesity - A New Survey

A survey of opinions on the causes of and effectiveness for treatment of obesity was carried out on data provided by questionnaires from 57 physicians and scientists involved in obesity research. Responses were grouped by region (Europe, North America, and South America), gender, age (30–50 and over 50 years), and professional training (MD or PhD). Metabolic factors were considered the most important cause of obesity overall with physical inactivity only slightly behind. There were no gender differences, but the older group thought physical inactivity was a more important cause than the younger group. Weight cycling overall was not considered very important, although it was significantly more important among the Ph.D. group. Low-fat diets were considered the most effective treatment, with the older group of respondents rating low-fat diet more highly than their younger colleagues. Exercise was viewed as a more important treatment among North Americans, and medications as less in the treatment of obesity. All groups viewed serotonergic and thermogenic drugs as the most effective treatments whose usefulness would increase during the next 10 years.     

Cholesterol lowering and the vessel wall: new insights and future perspectives.

The basis for most acute coronary events is either rupture or fissuring of unstable atherosclerotic plaques with subsequent thrombosis leading to coronary artery occlusion. The development of atherosclerotic plaques takes several decades, but the mechanical features determining its stability and the risk of rupture can change very rapidly depending on a number of internal factors. Unstable plaques have a large lipid core, a thin overlying fibrous cap and an abundance of inflammatory cells. The most important factor determining the plaque stability is the plasma level of atherogenic LDL particles. Increased levels of these particles cause endothelial dysfunction with impaired vasodilatation capacity and prevalence of vasoconstriction, maintain inflammatory infiltration of the plaque, impair the strength of the fibrous cap and facilitate aggregation and coagulation. Effective lowering of plasma cholesterol by pharmacological and non-pharmacological means can revert most of these processes and increase the plaque's mechanical stability within several hours to days. Lipid lowering therapy can therefore decrease the risk of acute coronary events within a very short space of time. Thus a radical decrease in lipid levels, along with modification of other risk factors, may become the cornerstone for treatment of acute coronary syndromes, in addition to being an effective treatment in primary and secondary prevention of coronary heart disease (CHD).