Pocket computers: a new aid to nutritional support.

A program has been written to run on a pocket computer (Sharp PC-1500) that can be used at the bedside to predict the nutritional requirements of patients with a wide range of clinical conditions. The predictions of the program showed good correlation with measured values for energy and nitrogen requirements. The program was used, with good results, in the management of over 100 patients needing nutritional support. The calculation of nutritional requirements for each patient individually facilitates more appropriate treatment and may also produce financial savings when compared with administration of a standard feeding regimen to all patients.     

Issues in clinical ethics consultation: an introduction

Any area that surges ahead as rapidly as this one [clinical ethics] has over the last five years is virtually certain to find that there are many problems which will need to be addressed. There will also be a need for persons working in this field (or studying it) to take some time to reflect on where it is going, as well as to examine some of the possible pitfalls -- both the obvious and the not so obvious -- which lie ahead. The series of papers in this issue of Theoretical Medicine have been written by a group of ethicists who have had a longstanding interest in the field of clinical ethics, and most of whom have spent many years working in the area. While all of the papers focus on the field of clinical ethics, they are very diverse in the topics covered. Some may be viewed as controversial by readers....     

Breeding aye-ayes: an aid to preserving biodiversity

In August 1992 an aye-aye Daubentonia madagascariensis (Primates) was bred in captivity for the first time. This species is the only living representative of a monotypic family and is endangered in its native Madagascar. A brief history of the captive breeding effort and a summary of the conservation problems facing the fauna, flora, and people of Madagascar is given. The role that a captive breeding programme for aye-ayes can fulfil as an aid to preserving biodiversity is discussed.     

Partial alignment of biomolecules: an aid to NMR characterization

Partial alignment of biomolecules in solution has added a new dimension to structural investigation by high-resolution NMR methods. Applications to proteins, nucleic acids and carbohydrates now abound. Limitations initially associated with compatibility of biomolecules with the liquid-crystal media commonly used to achieve alignment have begun to disappear. This is, in part, a result of the introduction of a wide variety of new media. Future applications to biologically important problems such as the structural organization of multi-domain proteins and multi-protein assemblies look very promising.     

LARaLink 2.0: a comprehensive aid to basic and clinical cytogenetic research

LARaLink 2.0 (Loci Analysis for Rearrangement Link) is an enabling web technology that permits the rapid retrieval of clinical cytogenetic and molecular data. New data mining capabilities have been incorporated into version 2.0, building upon LARaLink 1.0, to extend the utility of the system for applications in both the clinical and basic sciences. These include access to the Chromosomal Variation in Man database and the GEO database. Together these new resources enhance the user's ability to associate genotype with phenotype to identify potential gene candidates. Unlimited access for researchers exploring disease-gene relationships and for clinicians extending practice in patient care is available at LARaLink.bioinformatics.wayne.edu:8080/ unigene.     

Cats as an aid to teaching genetics

I have used an exercise involving domestic cats in the General Genetics course at the University of Nebraska-Lincoln for the past 5 years. Using a coherent set of traits in an organism familiar to the students makes it easy to illustrate principles of transmission and population genetics. The one-semester course consists primarily of sophomores and juniors who have either taken a one-semester introductory biology course, a one-semester cell biology course, or have a strong high school biology background. The students are given a handout and asked to determine the genotype at seven unlinked loci of at least one cat. To fill out the form, the students have to grasp such concepts as dominance, incomplete dominance, temperature-sensitive mutations, epistatic interactions, sex linkage, and variable expressivity. Completing the form reinforces these concepts as they observe the cat's phenotype and fill in the genotype. I then analyze the collected data and use it in my lectures on population genetics to illustrate the Hardy-Weinberg equilibrium, calculate allele frequencies, and use statistics. This allows the students to look at population genetics in a very positive light and provides concrete examples of some often misunderstood principles.     

Molecular simulation as an aid to experimentalists

Computer-based molecular simulation techniques are increasingly used to interpret experimental data on biomolecular systems at an atomic level. Direct comparison between experiment and simulation is, however, seldom straightforward. The available experimental data are limited in scope and generally correspond to averages over both time and space. A critical analysis of the various factors that may influence the apparent degree of agreement between the results of simulations and experimentally measured quantities is presented and illustrated using examples from recent literature.     

Locomotion studies as an aid in clinical assessment of childhood gait.

A clinical locomotion laboratory has been developed to provide quantitative information in the management of gait disorders. The biomedical engineering development of this system identified two major clinical constraints: (a) the need for instrumentation that would not alter the natural gait of the patient and (b) the need for data-processing techniques that would permit analysis and correlation of the large volume of electromyographic (EMg) and kinematic information. The net result has been a unit that incorporates a multichannel telemetry system to capture the EMG and foot-switch information and a television computer system to handle the kinematic information. Gait studies on children with hemiparesis, muscular dystrophy and cerebral palsy have yielded quantitative EMG and kinematic information on the pathomechanics of ambulation in these disorders. Because the information obtained is quantitative, an accurate measure of improvement (or lack of it) after treatment can be documented. Therefore, the locomotion laboratory may have an important role in the preoperative and postoperative evaluation of children whose abnormal gait may require surgical corrective procedures or rehabilitative treatment including the use of prostheses or orthoses.     

Problems in cervicovaginal cytology: fine structure as an aid to diagnosis

The ultrastructure of cytologically abnormal, thick cell groups and epithelial fragments in cervical and vaginal scrape material was investigated and found to be useful in differentiating between carcinoma in situ, invasive nonkeratinizing squamous carcinoma and adenocarcinoma of the endocervix and also in confirming the presence of cytologically suspected vault deposits of recurrent endometrial adenocarcinoma. It was demonstrated that although accurate evaluation of these thick groups in smear preparations is often not possible, thick sections of similar, plastic-embedded material showed some features which enabled a distinction to be made between squamous and glandular lesions and that these differences were more pronounced at the ultrastructural level. The squamous lesions were characterized by wide intercellular spaces with microvilli and tonofibrils within the cytoplasm while glandular lesions showed narrow intercellular spaces, prominent Golgi zones and endoplasmic reticulum together with mucus droplets in some cells.     

Freshwater diatom ecology: developing an experimental approach as an aid to interpreting field data

The observational and experimental approaches to ecological studies are outlined and contrasted. Most studies involving benthic diatoms are still at the observational stage. Community analyses are interpreted in relation to physico-chemical variables, but without reference to the intrinsic growth characteristics of the species or to biological interactions. By allowing separate investigation of the effects of chosen variables under controlled conditions, culture studies permit field predictions to be tested and our understanding of the constraints on growth of particular species to be improved.Results of culture experiments on four benthic diatom species grown under contrasting light, temperature, and pH regimes are presented and discussed in relation to their field distributions. Synedra ulna showed a positive response to both light and temperature; Meridion circulare was more sensitive to raised water temperature at higher light intensity; Pinnularia viridis and Eunotia exigua grew over wider ranges of temperature and pH than recorded from published data. The experimental results indicate that distribution data provide only partial information on ecological range; growth in the field may be constrained by one or more factors and their interactions.Whereas analysis of field data is a correlative exercise, an experimental approach allows investigation of the physiological responses contributing to the survival of species and the demonstration of causal relationships.