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PubMed1989

Pre-escape and escape aircraft maneuvers and gyrations: a critical under-reported problem affecting escape system performance and aircrew safety.

A major problem confronting both the requirements formulators and the designers of aircrew escape systems is defining the systems' operational emergency conditions. For years the community has relied on computerized compilations of such data. However, increasingly, examination of original records reveals that the report originators are not sufficiently thorough in completing the block sections of the form. As a consequence computerized searches for pre-escape and escape aircraft maneuvering and gyrations show these conditions to be dramatically under-reported. Several recent studies suggest this under-reporting approximates 100%. This is critical because the associated aircraft motions may adversely affect seat separation from the aircraft, degrading system stability, and aircrew safety.

Aerospace Medicine↗
PubMed1988

Interdisciplinary case management: a model for intervention.

Interdisciplinary case management is required when clients present problems that do not fall within the purview of any one discipline. The interdisciplinary approach entails the participation of professional and support staff, along with the client and his/her family, in diagnosis, individual program planning, implementation, and evaluation. For example, interdisciplinary case management for a patient with Prader-Willi syndrome (PWS) results in cost-effective, efficacious treatment. Because of the diversity of symptoms, the treatment of Prader-Willi syndrome must incorporate knowledge and skills from a variety of areas. A model for the interdisciplinary case management of PWS is presented. The model is problem focused and emphasizes goals formulated and acted upon by the disciplines represented on the client's treatment team. Communication and coordination of efforts are central to the utility of the model. Additional benefits of interdisciplinary case management include the opportunity for ongoing education and role expansion of team members.

Adolescent↗
PubMed1986

Computerized documentation of scoliosis.

The authors report their experience in the development of a computerized recording system in their scoliosis unit. The form of documentation used must be designed to comply with the memory of the available computer. Following a detailed analysis of the various fields comprising the documentation proforma, the technical methods used to minimise errors while loading the maximum number of cases into the computer are discussed. Complex statistical analyses are possible only with the aid of computerized documentation and it is hoped this will be used more frequently in future in departments specialising in the problems of vertebral deformity. The formulation of a common documentation proforma for scoliosis would unify the terminology, and make it possible to introduce comparability and homogeneity into the clinical data as well as the results of different techniques.

Computers↗
PubMed1985

Grief in chronic illness: assessment and management.

Grief is a normal reaction to the loss of physical function. Its symptoms, however, are often mistaken for major depressive episode and treatment may be inappropriate. Symptoms of grief include a preoccupation with the lost object (a limb, a function, a loved one), somatic distress, inappropriate behavior, hostility, and denial. Depression may be a manifestation of illness or drug therapy. Grief should be treated like a major depressive episode but without antidepressive medications. The first step in management of grief is the development of a proper therapeutic milieu which will encourage the reappearance of self worth. Once the milieu is established, specific rehabilitation problems can be addressed. In formulating a prognosis, it is important to consider the severity of the patient's disability, the premorbid psychologic make-up, and the type of family and community support available to the patient.

Chronic Disease↗
PubMed1993

Group sequential tests for bivariate response: interim analyses of clinical trials with both efficacy and safety endpoints.

We describe group sequential tests for a bivariate response. The tests are defined in terms of the two response components jointly, rather than through a single summary statistic. Such methods are appropriate when the two responses concern different aspects of a treatment; for example, one might wish to show that a new treatment is both as effective and as safe as the current standard. We present a formulation of the bivariate testing problem, introduce group sequential tests that satisfy Type I error conditions, and show how to find the sample size guaranteeing a specified power. We describe how properties of group sequential tests for bivariate normal observations can be computed by numerical integration.

Biometry↗
PubMed1993

Deficiency and envy: some factors impacting the analytic mind from listening to interpretation.

This paper examines some aspects of an unconscious process developing within the mind of the analyst; a process affecting both the way in which the analyst listens to the patient's material and the interpretations subsequently formulated. The paper highlights the problem of the analyst's 'mis-use' of theory as a protection against unbearable feelings of psychic pain, evoked by what is perhaps the most essential tool of psychoanalysis: the analyst's emotional contact with the patient's early experiences in infancy. Both the 'deficiency theory' and the concept of 'primary envy' are called into question during this inquiry. Some of the most recent work of the 'post-Kleinians (from Bion through to the present-day workers in England as well as in the Americas) is reviewed. Clinical examples, both from the author's own experience and from previously published material, are considered as illustrative of some factors which may impact upon the mind of the psychoanalyst from listening and interpretation.

Adult↗
PubMed1997

Lactose intolerance in persistent diarrhoea during childhood: the role of a traditional rice-lentil (Khitchri) and yogurt diet in nutritional management.

Lactose intolerance is frequently encountered in children with persistent diarrhoea (PD). Selection of an appropriate milk-based formulation is a major management problem in the developing world. In a consecutive series of studies, we evaluated the role of feeding a traditional rice-lentil (khitchri) diet alone (KY) or in combination with either soy formula (KY-Soy) a dilute buffalo milk (KY-B), in children (age 6 months-3 years) with PD. Serial observations of stool output, caloric intake and weight gain of these children over a 14 day period indicated satisfactory tolerance of the KY diet with adequate weight gain. The weight gain and stool output was however higher in lactose intolerant children, with the worst results seen with K-Y and buffalo milk combination. While lactose intolerant children with PD do have higher. rates of therapeutic failure, our data indicates that a traditional diet and yogurt combination can be used satisfactorily for nutritional rehabilitation in over 80% of such children.

Animals↗
PubMed1997

Dynamic organization of search results using the UMLS.

When people search the medical literature, they often are overwhelmed by the large number of documents retrieved. Many systems try to solve this problem by helping the user formulate a more specific search strategy. However, when users do not have a more specific question, they need tools to help them explore and understand the results, rather than to eliminate a portion of those results. This paper describes an approach that addresses this need by automatically grouping the results of a broad search into meaningful categories based on the user's query. This approach combines the main benefit of clustering techniques with the main benefit of classification techniques by taking advantage of the domain knowledge present in the UMLS. I present a preliminary evaluation that demonstrates that a categorization produced by this approach corresponds reasonably well to a physician's categorization.

Computer Systems↗
PubMed1997

Controlled diffusional release of dispersed solute drugs from biodegradable implants of various geometries.

Chronic diseases and pathological medical conditions requiring the administration of longterm pharmaceutical dosages have in the past been treated by oral administrations of tablets, pills and capsules or through the use of creams and ointments, suppositories, aerosols, and injectables. Such forms of drug delivery, which are still currently used today, provide a prompt release of the drug, but with significant fluctuations in the drug levels within various regions of the body. Repeated administrations of the drug are often needed, at rather precise intervals of time, in order to maintain these levels within a relatively narrow therapeutic range as a means of assuring effectiveness at the low end and of minimizing adverse effects at the higher end of the fluctuation spectrum. Recent technical advances now permit one to control the rate of drug delivery. The required therapeutic levels may thus be maintained over long periods of months and years through implanted rate-controlled drug release capsules. Two such novel drug delivery systems currently employed are implanted erodible polymeric and ceramic capsules. Mathematical modeling and computer simulations can be very effective in improving and optimizing the performance of the self-regulating release of therapeutic drugs into specific regions of the body. Further development is needed for the optimal design of such capsules. It is in this area, in particular, that a review will be presented of the mathematical modeling techniques susceptible to refine the development of a reliable tool for designing and predicting the resulting pharmaceutical dosages as a function of time and space. Of primary importance in such models are the time-varying effective permeability of the capsule to the various molecules composing the drug, the effective solubility and diffusion coefficients of the drug and its metabolites in the surrounding tissues and fluids and, finally, the uptake of the drug at the target organ. Mathematical models are presented for the diffusional release of a solute from an erodible matrix in which the initial drug loading c0 is greater than the solubility limit cs. An inward moving diffusional front separates the reservoir (unextracted region) containing the undissolved drug from the partially extracted region. The mathematical formulation of such moving boundary problems has wide application to heat transfer with melting phase transitions and diffusion-controlled growth of particles, in addition to our topic of controlled-release drug delivery. In spite of this diversity of applications, only a very few mathematical descriptions have been published for the analysis of release kinetics of a dispersed solute from polymeric or ceramic matrices. In these rare instances, perfect sink conditions are assumed, while matrix swelling, concentration-dependence of the solute diffusion coefficient and the external mass transfer resistance have been largely neglected. The ultimate goal of such an investigation is to provide a reliable design tool for the fabrication of specialized implantable capsule/drug combinations which will deliver pre-specified and reproducible dosages over a wide spectrum of conditions and required durations of therapeutic treatment. Such a mathematical/computational tool can also prove effective in the prediction of suitable dosages for other drugs of differing chemical and molecular properties which have not been subjected to time-consuming animal laboratory testing. Finally, such models may permit more realistic scaling of the required dosages of therapeutic drug for variations in diverse factors such as body weight or organ size and capacity of the patient (clinical medicine) or animal (veterinary medicine for farm animals). Additional applications of controlled-release drug delivery for insecticide and pesticide use in agriculture, and the control of pollution in lakes, rivers, marshes, etc. in which a pre-programmed dose-time schedule is necessary, further

Biocompatible Materials↗
PubMedDate not supplied

[The past, present and future of cell pathology problems].

Three stages of development in cellular pathology are analyzed. Evaluation of important achievements in the past which permitted the advance to the present stage in cellular pathology is given. New methods in experimental pathology resulted in the appearance of a new direction--molecular morphology and molecular cell pathology. The basic features of this direction and new problems to be resolved are formulated.

Animals↗
PubMed2002

A cognitive therapy model of social anxiety problems: potential limits on its effectiveness?

Cognitive therapy formulations of, and interventions for, social phobia are increasingly influential. In this article, relevant studies are reviewed and lead to a tentative conclusion that purely 'cognitive' interventions may, in fact, fail to provide optimum help for a large number of people likely to present to mental health services with problems of social anxiety.

Cognitive Behavioral Therapy↗
PubMed1984

The computation of the velocity field.

The organization of movement in the changing retinal image provides a valuable source of information for analysing the environment in terms of objects, their motion in space, and their three-dimensional structure. A description of this movement is not provided to our visual system directly, however; it must be inferred from the pattern of changing intensity that reaches the eye. This paper examines the problem of motion measurement, which we formulate as the computation of an instantaneous two-dimensional velocity field from the changing image. Initial measurements of motion take place at the location of significant intensity changes. These measurements provide only one component of local velocity, and must be integrated to compute the two-dimensional velocity field. A fundamental problem for this integration stage is that the velocity field is not determined uniquely from information available in the changing image. We formulate an additional constraint of smoothness of the velocity field, based on the physical assumption that surfaces are generally smooth, which allows the computation of a unique velocity field. A theoretical analysis of the conditions under which this computation yields the correct velocity field suggests that the solution is physically plausible. Empirical studies show the predictions of this computation to be consistent with human motion perception.

Humans↗
PubMedDate not supplied

Evaluation of intravenous flavopiridol formulations.

Flavopiridol is currently under consideration as a parenteral treatment of breast tumors. The solubility of this poorly water-soluble compound can be increased by a number of methods. However, because of its low water solubility, precipitation of the solubilized drug upon injection can be a problem. The potential of several flavopiridol formulations to precipitate is evaluated using a static serial dilution technique. It is shown that formulations containing up to 10 mg/mL of flavopiridol which produce negligible precipitation on dilution can be developed.

Antineoplastic Agents↗
PubMed2003

[Evaluation for enhanced aphidicidal activity of a noval emulsifiable formulation of Beauveria bassiana conidia].

A noval emulsifiable formulation (EF) of Beauveria bassiana SG8702 containing 10(10) conidia/mL was prepared by suspending dry conidia in mineral oil-based liquid containing emulsifier, stabilizer and UV protectant (emulsion), and then bioassayed on newly merged adults of the green peach aphid, Myzus percisae, in parallel to the unformulated conidia (UC). For inoculation, five gradient concentrations of aqueous EF and UC suspensions (5 x 10(5) - 1 x 10(8) conidia/mL) were separately sprayed on to aphids on detached cabbage leaves (30 - 40 adults/leaf) using a Micro Ulva hand-held sprayer, generating EF dosages of 1.5, 6.3, 32.6, 87.6 and 701.1 conidia/mm2, and UC dosages of 2.8, 9.2, 52.7, 114.8 and 1005.9 conidia/mm2, respectively. All dosage treatments including controls for EF (100-fold dilution of the emulsion) and UC (water spray) were replicated three times (aphid colonies on three leaves), and maintained in Petri dishes at 23 degrees C and 12 : 12 (L: D) for 8-day daily records. Cadavers, whenever found, were moved into a moist chamber to facilitate fungal outgrowths for verification of B. bassiana infection. The resulting data fit very well to time-dose-mortality model with EF having a larger dose effect (1.05 +/- 0.10) than UC (0.82 +/- 0.11) and also faster time effect. The estimates of the dose- and time-effect parameters were then used to compute lethal concentrations (LC50) and time lengths (LT50). The estimates of LC50 with 95% confidence intervals for both EF and UC were 9.0 (6.9 - 11.6) and 634 (263 - 1532) conidia/mm2 on day 4 after spray, and 3.3 (2.4 - 4.6) and 5.3 (3.2 - 8.6) on day 7, apparently decreasing with increasing time lengths after spray. The estimates of LT50 for EF and UC were 4.9 d and 7.2 d at 5 conidia/mm2, 4.0 d and 5.6 d at 10 conidia/mm2, and 3.2 d and 4.5 d at 100 conidia/mm2, indicating a trend of decrease with increasing counts of conidia attached to the leaves. The results indicate that the emulsifiable formulation of B. bassiana conidia had greater aphidicidal activity than the unformulated conidia. Finally, problems with evaluation of mycoinsecticides and other microbial formulations are discussed and technical standards are recommended.

Animals↗
PubMedDate not supplied

[Contribution of the Italian Society of Occupational Medicine and Industrial Health to the formulation of the EEC Directives].

There are some problems in medico-legal approach and law interpretation about AIDS. The European Community has developed a wide program for health protection at workplace, giving Directives containing interesting starting points for AIDS prevention. The author discusses the main rules to be applied in regulations and specific procedures, and stresses the contribution of the Italian Society of Occupational Medicine and Industrial Hygiene to the formulation of these Directives.

Acquired Immunodeficiency Syndrome↗
PubMed1995

Pathways, pathway tubes, pathway docking, and propagators in electron transfer proteins.

The simplest views of long-range electron transfer utilize flat one-dimensional barrier tunneling models, neglecting structural details of the protein medium. The pathway model of protein electron transfer reintroduces structure by distinguishing between covalent bonds, hydrogen bonds, and van der Waals contacts. These three kinds of interactions in a tunneling pathway each have distinctive decay factors associated with them. The distribution and arrangement of these bonded and nonbonded contacts in a folded protein varies tremendously between structures, adding a richness to the tunneling problem that is absent in simpler views. We review the pathway model and the predictions that it makes for protein electron transfer rates in small proteins, docked proteins, and the photosynthetic reactions center. We also review the formulation of the protein electron transfer problem as an effective two-level system. New multi-pathway approaches and improved electronic Hamiltonians are described briefly as well.

Electron Transport↗
PubMed1984

Quantitative theories for clinical decision making.

Clinical work involves a great many decisions in situations characterized by uncertainty and by the need for value judgments. Formal, mostly quantitative approaches to medical decision making have been developed over the last thirty years. The best known theories are discriminant analysis or supervised pattern recognition, decision analysis and, more recently, artificial intelligence. Discriminant analysis is used for estimating diagnostic probabilities on the basis of diagnostic data. Outcome, action, state, probability, utility, and choice are the main concepts of decision analysis. Problems of diagnosis and therapy choice can be structured within the framework of decision analysis. The quality of a decision analysis largely depends on a good structuring of the problem, and on the quality of the probability and utility assessments made during the analysis. Decision analysis is basically a prescriptive theory for decision making in individual patient management. Other areas of application include basic and advanced teaching, formulation, explication and analysis of clinical problems, detection of gaps in clinical knowledge, development of clinical protocols, etc.

Decision Making↗