Senior house officers: the lost tribes.

There are more senior house officers than doctors in any other training grade in Britain but nobody knows what they do in hospitals or has a clear idea what skills they should be learning. Nobody is responsible for them and they suffer from having a poor career structure and inadequate training. Now that there are government initiatives to reduce the hours that junior doctors work and to limit the time it takes to train to become a specialist, the problems that senior house officers face can no longer be ignored. A conference for senior house officers held last week talked about the problems that they face and tried to find some solutions.     

The stem cell system in demosponges: suggested involvement of two types of cells: archeocytes (active stem cells) and choanocytes (food-entrapping flagellated cells)

Major questions about stem cell systems include what type(s) of stem cells are involved (unipotent/totipotent/pluripotent/multipotent stem cells) and how the self-renewal and differentiation of stem cells are regulated. Sponges, the sister group of all other animals and probably the earliest branching multicellular lineage of extant animals, are thought to possess totipotent stem cells. This review introduces what is known about the stem cells in sponges based on histological studies and also on recent molecular biological studies that have started to reveal the molecular and cellular mechanisms of the stem cell system in sponges (mainly in demosponges). The currently proposed model of the stem cell system in demosponges is described, and the possible applicability of this model to other classes of sponges is discussed. Finally, a possible scenario of the evolution of stem cells, including how migrating stem cells arose in the urmetazoan (the last common ancestor of metazoans) and the evolutionary origin of germ line cells in the urbilaterian (the last common ancestor of bilaterians), are discussed.     

Ocular immune privilege: a review

The definition of the term 'immune privilege' has evolved over the last century. Current usage refers to a state within a particular organ or tissue in which elements of normal immunity are absent. The fact that this deficiency is thought to be generally beneficial has compelled others to go a step further and venture that immune privilege acts to minimize expression of immunopathology. The purpose of this article is to review which parts of the eye hold immune privileged status, what mechanisms contribute to it, and what clinical benefits may have driven the development of these unique immune environments. The article ends with an examination of recent studies which have sought to use components of ocular immune privilege to prevent systemic autoimmune disease.     

DNA sequencing: present limitations and prospects for the future

As the human genome program gets under way, we examine the progress made since the first human genome meeting in Santa Cruz in 1985. The lessons of the last 5 years demonstrate that progress has been much slower than anticipated. The new technology being developed in 1985 was fluorescent sequencing and multiplexing. These techniques are now established, but they still have to produce a substantial sequence to rival those determined by conventional technology. Inspection of the EMBL and GenBank databases shows few large sequences have been determined and that there is a large discrepancy between what is theoretically possible and what has been achieved so far.     

Telomeric chromatin: roles in aging, cancer and hereditary disease

Over the last several years there has been an explosion in our understanding of the organization of telomeric chromatin in mammals. As in other regions of the genome, chromatin composition at the telomere regulates structure, which defines function. Mammalian telomeres, similar to what has been demonstrated for telomeres of other eukaryotes, carry marks of heterochromatin and alteration in this underlying epigenetic code has effects on telomere replication and recombination. Experiments aimed at determining links between changes in telomeric chromatin and possible roles in aging and disease are beginning to emerge. The rapid refinement of our knowledge of the structure and alterations in telomeric chromatin over the last several years makes it likely that we are just seeing the tip of the iceberg.     

Beyond the Taboo: Imagining Incest

This article provides an overview of anthropology's 150-year discussion of the incest taboo in light of the last 30 years of feminist and psychoanalytic discoveries about the incestuous abuse of children, it invites anthropologists to explore incest ethnographically and offers three suggested ways: one biosocial, a second social relational, and a third psychoanalytic, focusing on a connection between what psychologists call dissociation and what anthropologists call trance or possession. [Key words: incest taboo, childhood sexual abuse, dissociation, trance/possession, innate avoidance mechanism]     

Music Education for Young Children in Scandinavia: Policy,Philosophy, or Wishful Thinking?

The author discusses current policies, philosophies, and educational practices of early childhood music education in Scandinavia (Denmark, Norway, and Sweden) and to what extent they meet the challenges of music education for young children. Nearly all children use day care provisions, and they are a governmental responsibility. The author reviews governmental policies regarding general pedagogical goals of day care and kindergarten in Scandinavia. During the last decade, teaching plans for preschool pedagogy were implemented and the author discusses to what extent the plans meet current challenges of music education. The author also discusses the challenges of teacher-training programs in light of current policies regarding music education in early childhood.     

Commentary: setting aside tradition when dealing with endocrine disruptors

In 1996, the US Congress directed the Environmental Protection Agency to produce screens and assays to detect estrogenic and other endocrine-disrupting chemicals in food and water. To date, there are none. Years have been wasted in attempts to utilize traditional toxicological approaches to solve the problem, when in retrospect, it is now apparent that the delay in part stems from the reluctance to attack the problem with entirely new approaches. To develop new testing protocols, it is necessary to set aside much of the dogma of toxicology and to begin again with open minds. A few pertinent examples are provided concerning what has been overlooked and what needs to be done. In particular, it is necessary to give close attention to the selection of animal strain and diet, factors that were only loosely controlled historically when one takes into consideration what has been learned in the last decade. Vast numbers of animals have been sacrificed, and more will be sacrificed, in futile attempts to validate assays and to develop safety standards unless knowledge gained over the past decade concerning the sensitivity and complexity of the endocrine system is taken into consideration.     

Phenotypic variation with respect to fitness: the basis for rank-order selection*

Having argued that phenotypic variation with respect to the component of fitness involved in withstanding density stress is useful for the persistence of populations through time, the sources of such variation are described. Age differences and differences caused by the accidental encounters of dissimilar microenvironments are non-genetic in origin. Genetic bases for phenotypic variation can either be proximate (each individual having a unique genotype) or ultimate. The latter case is one in which the genotypes of individuals are such that the progeny they produce are phenotypically variable. Selection favouring such genotypes can be shown to be Darwinian; group selection is not required. A means for revealing instances of the ultimate genetic control of phenotypic variation is suggested: measures of what should be error variance prove to be larger than those which should, under normal circumstances, include error variance. The last increment of variation that causes what might otherwise be repetitive structures to differ can be ascribed to decisions that are genetically pre-set within developmental programmes.     

Proteomics data validation: why all must provide data

The field of proteomics has gained considerable momentum over the last years as new technologies and better instrumentation allowed the field to mature from what resembled a cottage industry into a high-throughput means to identify, characterize and quantify hundreds of proteins. The identifications and (relative) quantitation values obtained are often controversial however, as various techniques and different software platforms are used in the many laboratories worldwide. This Opinion attempts to shed some light on some of the underlying issues, and proposes certain guidelines authors can adhere to in order to allow others to validate their findings.     

Old people's homes: the relatives' view.

On 1 April new arrangements came into force for arranging and funding residential care for elderly people in Britain. From now on those who seem to need full time care will be assessed first by care managers employed by local authority social services departments. This may lead to admission to an old people''s home or a nursing home. Local authorities have been told to consult both users and carers about such decisions. But what about relatives who have not actually been giving care directly? The Relatives Association was set up last year as a voluntary organisation for the relatives and friends of older people living in residential homes. Below, its vice president, Mavis Nicholson, a journalist and broadcaster whose mother died of Alzheimer''s disease in a residential home last year, gives her personal view of being such a relative. And Dorothy White, the association''s founder, explains what the future may hold for elderly residents and their relatives.     

The Drosophila circadian clock: what we know and what we don't know.

Circadian rhythms are regulated by endogenous body clocks, which are formed by rhythmic cycles of clock gene expression. Almost all reviews of the Drosophila circadian clock state that the intracellular oscillator is based on a simple negative feedback loop. However, not many 'simple' feedback loops in biology last for 24 h. Instead, the Drosophila clock is a series of precisely timed steps that are deliberately slow. In this paper, I will discuss the current model for how the Drosophila clock is regulated, and ask what questions remain to be answered.     

Mini-review: Mechanical factors affecting cartilage regeneration in vitro

In the last 5 to 10 years, tissue engineering has revolutionized the way in which medical researchers and clinicians are thinking of and, in some cases, actually treating diseases involving tissue damage and destruction. One such disease, osteoarthritis, results from progressive degeneration of articular cartilage, which has a limited ability to repair itself. With tissue engineering, scientists are now able to regenerate cartilage in vitro from isolated mature chondrocytes. While the regeneration process is still not fully understood, enough has been learned that physicians are already implanting cultured chondrocytes into humans and other animals in the hopes of effecting joint repair. One aspect which has not been fully explored is the effect of mechanical stress on developing and implanted cartilage, especially over the long term. This article will review in brief what is now known about the mechanical factors affecting cartilage regeneration in vitro and what still remains to be determined for optimum tissue engineering of cartilage constructs. (c) 1996 John Wiley & Sons, Inc.     

Microevolution of the Chibcha-speaking peoples of lower Central America: rare genes in an Amerindian complex.

Models are developed for the survival, history, and spread of variant alleles, in order to consider what can, and what cannot, be inferred from this type of data. The high variances of the processes involved, and questions of sampling, place severe limitations on inferences. Nonetheless, by combining information on a number of rare variants observed in a group of interrelated populations, reliable qualitative inferences are possible. These ideas and models are developed in the context of data on five rare variants and six private polymorphisms observed in eight Chibcha-speaking tribes of Costa Rica and Panama. The decline and fragmentation of the Amerindian populations of Central America over the last 300 years create considerable difficulties in attempting inference of past genetic events. However, these tribes have been well studied genetically, anthropologically, and linguistically and thus provide an excellent framework for the study of rare-variant spread.     

British mammal populations: fifty years of change

• 1 Agricultural intensification, urbanization, overpopulation by both native and invasive species and diseases have all had marked effects on populations of British mammals over the last 50 years.
• 2 Here, accounts are presented of the effects of these processes with a prospective view of what the future holds for the mammals of Britain.

     

Predicting multisite protein subcellular locations: progress and challenges

In the last two decades, predicting protein subcellular locations has become a hot topic in bioinformatics. A number of algorithms and online services have been developed to computationally assign a subcellular location to a given protein sequence. With the progress of many proteome projects, more and more proteins are annotated with more than one subcellular location. However, multisite prediction has only been considered in a handful of recent studies, in which there are several common challenges. In this special report, the authors discuss what these challenges are, why these challenges are important and how the existing studies gave their solutions. Finally, a vision of the future of predicting multisite protein subcellular locations is given.     

Bodies and borders: a new cultural history of medicine

Both medicine and the history of medicine have seen many changes in the last four decades. The way we tell the story of medical developments no longer concentrates on the important doctors and their ideas. The influences of social history in the 1960s and 1970s and cultural history in the 1980s and 1990s have broadened and enriched the interpretations of our medical past. The social historians have helped us to include politics, economics, and the leading ideas of any period we wanted to study; the cultural approach has added ethnography as well as an emphasis on language or discourse.Today there is a new history of medicine, one far more willing to cross disciplinary boundaries to ask questions about how we know what we know and why we do what we do.This article highlights some of the work in the adjoining fields of medical anthropology and of literature and medicine to demonstrate new interests, new questions, and new methods of inquiry. However, although we have cast our nets far more widely in the process of professionalizing the history of medicine, there is a question about whether we have lost the appeal to one of our core constituencies: medical students and physicians. We need to welcome some of the new changes in medical history as in medicine itself; the common goal is to achieve a better understanding of what we have done and what we are doing.     

Postgenomic futures: translations across the machine-nature border in systems biology

Abstract

This article discusses the production of new “postgenomic” knowledges that aim to be more ecological and “wholistic” than the reductionist genetics of the last forty years. It examines systems biology and, briefly, developmental systems theory, which are two approaches that attempt to model complexities in biology. System biological metaphors and languages have been in part taken from engineering models of automobiles, airplanes and robots and then applied to complex living systems. Systems biology is only the most recent example and perhaps an excellent case in which to study this movement back and forth across the machine-living organism border in Euro-American biology to track how what we know to be nature and machine is constituted. This article argues for a careful analysis of this historical production specifically around the question of what is lost in translation at these border crossings and their potential consequences.