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PubMed1998

A re-appraisal of the tri-axial chart for monitoring arterial acid-base values.

OBJECTIVE: To demonstrate the practicability of a tri-axial chart for the graphical and quantitative monitoring of arterial pH, arterial carbon dioxide partial pressure (PaCO2) and actual arterial bicarbonate-ion concentration (a[HCO3-]) in intensive care patients. DESIGN: Case report. SETTING: A general intensive care unit (ICU). METHODS: Using a standard mathematical transformation, a data set of pH, log PaCO2 and log a[HCO3-] values can be transformed in such a way that a graphical display of all three variables is possible while being faithful to their linear relationship. Remarkably, the graphical display closely resembles the tri-axial chart that Hastings and Steinhaus described in 1931 for studying displacements of the acid-base balance. Two new monitoring parameters based on the chart and the transformation are described. One monitors the abnormality of the acid-base status while the other monitors the rate of acid-base changes. CONCLUSIONS: With the tri-axial acid-base chart, the complete acid-base status can be faithfully monitored. Moreover, the proposed monitoring parameters provide extra information about the arterial acid-base status that, otherwise, would remain hidden.

Acid-Base Imbalance↗
PubMed2004

Geovisualization to support the exploration of large health and demographic survey data.

BACKGROUND: Survey data are increasingly abundant from many international projects and national statistics. They are generally comprehensive and cover local, regional as well as national levels census in many domains including health, demography, human development, and economy. These surveys result in several hundred indicators. Geographical analysis of such large amount of data is often a difficult task and searching for patterns is particularly a difficult challenge. Geovisualization research is increasingly dealing with the exploration of patterns and relationships in such large datasets for understanding underlying geographical processes. One of the attempts has been to use Artificial Neural Networks as a technology especially useful in situations where the numbers are vast and the relationships are often unclear or even hidden. RESULTS: We investigate ways to integrate computational analysis based on a Self-Organizing Map neural network, with visual representations of derived structures and patterns in a framework for exploratory visualization to support visual data mining and knowledge discovery. The framework suggests ways to explore the general structure of the dataset in its multidimensional space in order to provide clues for further exploration of correlations and relationships. CONCLUSION: In this paper, the proposed framework is used to explore a demographic and health survey data. Several graphical representations (information spaces) are used to depict the general structure and clustering of the data and get insight about the relationships among the different variables. Detail exploration of correlations and relationships among the attributes is provided. Results of the analysis are also presented in maps and other graphics.

Journal Article↗
PubMed2000

Complete cytoreduction: is epithelial ovarian cancer confined to the pelvis biologically different from bulky abdominal disease?

OBJECTIVES: The aim of this study was to determine whether site and size of tumor masses prior to complete surgical cytoreduction affect outcome survival. METHODS: A retrospective review was performed of 53 women with stage II and III epithelial ovarian cancer following complete surgical cytoreduction. RESULTS: Fifteen cases (28%) were classified as stage II and the remaining 38 cases (72%) as stage III. The overall median survival was 58 months with overall 2- and 5-year survivals of 76 and 42%, respectively. On univariate analysis, women with well differentiated tumors did significantly better than those with moderately or poorly differentiated tumours (P = 0.0009). FIGO stage did not reach statistical significance (P = 0.066). On multivariate analysis, comparing patient's age, previous history of pelvic surgery, previous history of malignancy, performance of lymphadenectomy for visibly/palpably enlarged nodes, performance of bowel resection, presence of concomitant tumors, positive pelvic and/or para-aortic lymph nodes, histological type, histological grade, and FIGO stage, only histological grade remained an independent variable affecting outcome survival (P = 0.0004; FIGO stage, P = 0.22) (hazard ratio = 6.5: well versus poor differentiation, 95% confidence interval, 1.7-25.5). CONCLUSION: When surgical cytoreduction to no visible disease has been achieved in women with stage II and III epithelial ovarian cancer, FIGO stage, i.e., site and size of tumor masses prior to surgical cytoreduction, does not appear to influence outcome survival. The aggressiveness of the remaining microscopic disease would seem to be determined largely by histological grade. Bearing in mind the retrospective nature of this study and the relatively small cohort of patients, the results would appear to suggest that it is unlikely that there are any other significant parameters (hidden factors) affecting tumor biology which are independent of tumor grade in these patients. A possible implication of this result is that complete surgical cytoreduction confers a survival benefit by producing a biologically more homogeneous tumor.

Abdominal Neoplasms↗
PubMed2000

Eavesdropping on insects hidden in soil and interior structures of plants.

Accelerometer, electret microphone, and piezoelectric disk acoustic systems were evaluated for their potential to detect hidden insect infestations in soil and interior structures of plants. Coleopteran grubs (the scarabaeids Phyllophaga spp. and Cyclocephala spp.) and the curculionids Diaprepes abbreviatus (L.) and Otiorhynchus sulcatus (F.) weighing 50-300 mg were detected easily in the laboratory and in the field except under extremely windy or noisy conditions. Cephus cinctus Norton (Hymenoptera: Cephidae) larvae weighing 1-12 mg could be detected in small pots of wheat in the laboratory by taking moderate precautions to eliminate background noise. Insect sounds could be distinguished from background noises by differences in frequency and temporal patterns, but insects of similarly sized species could not be distinguished easily from each other. Insect activity was highly variable among individuals and species, although D. abbreviatus grubs tended to be more active than those of O. sulcatus. Tests were done to compare acoustically predicted infestations with the contents of soil samples taken at recording sites. Under laboratory or ideal field conditions, active insects within approximately 30 cm were identified with nearly 100% reliability. In field tests under adverse conditions, the reliability decreased to approximately 75%. These results indicate that acoustic systems with vibration sensors have considerable potential as activity monitors in the laboratory and as field tools for rapid, nondestructive scouting and mapping of soil insect populations.

Acoustics↗
PubMed2002

A role for tertiary structure in the generation of antigenic diversity and molecular association of the Tams1 polypeptide in Theileria annulata.

The major merozoite-piroplasm surface antigen (mMPSA) of Theileria annulata, Tams1, is known to be antigenically diverse. The possession of variable N-linked glycosylation sites and removal of monoclonal antibody 5E1 reactivity by mild periodate treatment suggested, previously, that divergent epitopes may be conferred by secondary modification. This study has shown that monoclonal antibody 5E1 and polyspecific antisera raised against the native protein react against divergent amino acid epitopes that are dependent on a molecular conformation that is sensitive to periodate. Therefore, no experimental evidence exists to confirm the sequence prediction that Tams1 undergoes N-linked glycosylation. Data is also presented indicating that the conformation of the antigen results in presentation of divergent regions on the external surface of the molecule, while conserved regions are more likely to be internal and hidden. In addition, non-reducing SDS-PAGE analysis demonstrated that Tams1 can undergo molecular association to form homo-dimers, trimers and multimers. The potential influence of tertiary structure and inter-molecular association on Tams1 diversity and function is discussed.

Amino Acid Sequence↗
PubMedDate not supplied

['Intuition or exactness? Intuitive positioning of the bed headboard in critical patients. Do we need to measure it?].

OBJECTIVE: To explore the skill of the nursery staff of an intensive care unit (ICU) to set the head of the bed accurately and to determine the need to incorporate a slope indicator in each bed. METHODS: Observational prospective study to measure the positioning of the head of the bed at 30 degrees and 45 degrees from 0 degrees in beds with slope indicator that was hidden during the study. SETTING: A neurosurgery ICU with thirteen boxes. STUDY PERIOD: from November-2003 to January-2004. Subject : nursery staff. RESULTS: 228 measures were made, 160 (50% at 30 degrees and 50% at 45 degrees ) were made by nurses, and 68 (50% at 30 degrees and 50% at 45 degrees ) by auxiliary nurses. At both positions there were 26 correct settings. Mean was 20 degrees and 30 degrees at 30 degrees and 45 degrees , respectively. There were not differences between nurses and auxiliary nurses at 30 degrees (22.6 +/- 1.5 vs 21.8 +/- 2.4) nor at (33.3 +/- 2 vs 33.8 +/- 3.3). There were not significant differences due to work experience nor respect of analysed variables (intracranial pressure monitoring, squatting, etc.). CONCLUSION: We set the head of the bed under the recommended slope for this type of patients, regardless of the analysed variables. We think that an objective slope degree indicator is mandatory in this kind of beds in order to achieve an accuracy positioning.

Beds↗
PubMed2006

Evaluating disease management programme effectiveness: an introduction to instrumental variables.

This paper introduces the concept of instrumental variables (IVs) as a means of providing an unbiased estimate of treatment effects in evaluating disease management (DM) programme effectiveness. Model development is described using zip codes as the IV. Three diabetes DM outcomes were evaluated: annual diabetes costs, emergency department (ED) visits and hospital days. Both ordinary least squares (OLS) and IV estimates showed a significant treatment effect for diabetes costs (P = 0.011) but neither model produced a significant treatment effect for ED visits. However, the IV estimate showed a significant treatment effect for hospital days (P = 0.006) whereas the OLS model did not. These results illustrate the utility of IV estimation when the OLS model is sensitive to the confounding effect of hidden bias.

Data Interpretation, Statistical↗
PubMed2000

Effect of isocapnic hypoxia on variational activity of breathing.

In the presence of either hypocapnia or sleep, hypoxia has been shown to induce periodic breathing and increase the total variational activity of breath components. It is not known whether hypoxia induces alterations in breathing variability during wakefulness and in the absence of hypocapnia. To address this issue, we studied nonobtrusively 14 healthy awake subjects before and during the delivery of a hypoxic gas mixture via a plastic hood; the subjects' oxygen saturation decreased from 98 to 79% and end-tidal carbon dioxide tension was kept constant. Compared with air, isocapnic hypoxia increased the gross variability of minute ventilation (V I), tidal volume (VT), inspiratory time (TI), and expiratory time (TE) (all p < 0.004). Isocapnic hypoxia decreased the autocorrelation coefficient at a lag of one breath for TE (p < 0. 008) and V I (p = 0.07), the number of consecutive breath lags having significant autocorrelation coefficients for TE (p = 0.03), and the cycle time of oscillations in V I (p = 0.03). When partitioned, the increase in total variational activity during isocapnic hypoxia was found to result from increases in the random fractions of V I, VT, TI, and TE (all p < 0.05), and the oscillatory fractions of V I, VT, and TE (all p < 0.03). In conclusion, hypoxia induced hidden oscillations in V I, VT, and TE despite wakefulness and an isocapnic state, suggesting that neural responses may have a more important role in the genesis of hypoxia-induced oscillations than previously reported.

Adult↗
PubMed1977

[The trigemino-facial reflexes: a methodological approach to the evaluation of facial nerve function (author's transl)].

Since 1952 electromyographic registration of the trigemino-facial reflexes have been repeatedly described to evaluate facial nerve function. Comparable to peripheral nerve conduction velocity studies, this method enables us to detect intratemporal lesions. In order to obtain optimal results, we modified the registration technique of the trigemino-facial reflexes as regard to the following items: 1. Because of great interindividual variability of latencies and amplitudes this method should be used only by comparing the right and the left side. For a reliable assessment of both, recovery and detoriation of the facial nerve a standardized stimulation and recording technique is necessary. Stimulus strength should be defined by the applied current rather than voltage. 2. Since, in many cases, only certain neurones of the facial nerve are affected with different degree, important information is gained by recording not only from the M. orbicularis oculi but also from M. levator labii, M. zygomaticus and M. orbicularis oris. 3. In order to detect small reflex responses in severe and advanced cases, averaging technique should be applied. Thus, minute potentials hidden in the amplifier noise can be detected and clearly defined as either a stimulus dependent reflex response or unvoluntary muscle activity.

Evoked Potentials↗
PubMed2004

The role of context specificity in learning: the effects of training context on explosives detection in dogs.

Various experiments revealed that if an animal learns a stimulus-response-reinforcer relationship in one context and is then tested in another context there is usually a lessening of stimulus control, and the same discriminative stimuli that reliably controlled the behavior in the first context will have less effect in the new context. This reduction in performance is known as the "context shift effect." The effect of changing context on the probability of detecting explosives was investigated in seven highly trained explosives detection dogs (EDDs). In experiment 1 the dogs were trained alternately on path A, which always had five hidden explosives, and on a very similar path B, which never had any explosives. Within a few sessions the dogs showed a significant decrease in search behavior on path B, but not on path A. In experiment 2 the same dogs were trained only on path B with a target density of one explosive hidden every 4th day. The probability of the dogs now detecting the explosive was found to be significantly lower than in experiment 1. In experiment 3 the effect of the low target density as used in experiment 2 was investigated on a new but very similar path C. Both the detection probability for the one explosive every 4th day on the new path and the motivation to search were significantly higher than found in experiment 2. Finally, in experiment 4, an attempt was made to recondition the dogs to search on path B. Although trained for 12 daily sessions with one explosive hidden every session, the dogs failed to regain the normal levels of motivation they had shown on both new paths and on the paths that they knew usually contained explosives. The findings reveal that even a very intensively trained EDD will rapidly learn that a specific stretch of path does not contain explosives. The dog will then be less motivated to search and will miss newly placed targets. This learning is specific to the formerly always-clean path and is to some extent irreversible. However, the dog will search and detect normally on new paths even if they are very similar to the always-clean path. The data are discussed in terms of variables affecting renewal. The results suggest that following training designed to make a behavior "context independent," any extinction training will not generalize beyond that specific context used during the extinction training. In addition, if the behavior is extinguished in a specific context, it will be very difficult to restore that behavior in that context. These conclusions should be considered by anyone attempting to extinguish well-established trans-context behaviors.

Animals↗
PubMed2006

CHARGE syndrome.

CHARGE syndrome was initially defined as a non-random association of anomalies (Coloboma, Heart defect, Atresia choanae, Retarded growth and development, Genital hypoplasia, Ear anomalies/deafness). In 1998, an expert group defined the major (the classical 4C's: Choanal atresia, Coloboma, Characteristic ears and Cranial nerve anomalies) and minor criteria of CHARGE syndrome. Individuals with all four major characteristics or three major and three minor characteristics are highly likely to have CHARGE syndrome. However, there have been individuals genetically identified with CHARGE syndrome without the classical choanal atresia and coloboma. The reported incidence of CHARGE syndrome ranges from 0.1-1.2/10,000 and depends on professional recognition. Coloboma mainly affects the retina. Major and minor congenital heart defects (the commonest cyanotic heart defect is tetralogy of Fallot) occur in 75-80% of patients. Choanal atresia may be membranous or bony; bilateral or unilateral. Mental retardation is variable with intelligence quotients (IQ) ranging from normal to profound retardation. Under-development of the external genitalia is a common finding in males but it is less apparent in females. Ear abnormalities include a classical finding of unusually shaped ears and hearing loss (conductive and/or nerve deafness that ranges from mild to severe deafness). Multiple cranial nerve dysfunctions are common. A behavioral phenotype for CHARGE syndrome is emerging. Mutations in the CHD7 gene (member of the chromodomain helicase DNA protein family) are detected in over 75% of patients with CHARGE syndrome. Children with CHARGE syndrome require intensive medical management as well as numerous surgical interventions. They also need multidisciplinary follow up. Some of the hidden issues of CHARGE syndrome are often forgotten, one being the feeding adaptation of these children, which needs an early aggressive approach from a feeding team. As the child develops, challenging behaviors become more common and require adaptation of educational and therapeutic services, including behavioral and pharmacological interventions.

Abnormalities, Multiple↗
PubMed2003

Repeated spatial acquisition: effects of NMDA antagonists and morphine.

Effects of morphine and 2 N-methyl-D-aspartate (NMDA) receptor antagonists, phencyclidine and LY235959, were studied using a within-subject, repeated-acquisition/performance procedure adapted to the Morris Swim Task. In the performance component, subjects swam to a hidden platform that was always in the same location in the pool. In the acquisition component, the platform was moved to a different place for each session. Baseline training produced rapid and direct swims to the platform in the performance component and steep within-session learning curves in the acquisition component. All 3 compounds increased swim distances, escape latencies, and slowed swim speed in a dose-dependent manner, but only morphine consistently produced selective impairments on acquisition. NMDA antagonists generally affected acquisition only at doses that also disrupted performance, although phencyclidine produced selective effects in some animals. These outcomes were different than those from studies of response chains in primates, suggesting that task and species variables may be important determinants of drug effects on acquisition.

Analgesics, Opioid↗
PubMed1980

Morphological and cytoenzymatic characteristics of peripheral zone of lytic plaques induced by mycobacterial phages.

Morphology and cytoenzymatic characteristics were studied using potassium tellurite, of peripheral zones of lytic plaques in fast growing mycobacteria (ATCC 607, Redmond No 521, Penso S1P) exposed to various mycobacterial phages and slowly growing M. bovis BCG, H37RV 50 gamma INH resistant strains. The latter revealed on borders of lytic plaques a bright tellurite-negative zone of variable width, macroscopically undemonstrable in culture free from potassium tellurite. Microscopically only single mycobacteria of various shapes, whereas in the tellurite-positive zone typical arrangement of BCG rods in compact, strong acid-fast cords present also in the so-called grey zone contacting the tellurite-negative zone, were found. The said tellurite zonal phenomen is explained by abortive infection with phages under study, which results in killing the mycobacterial cells without phage multiplication. The microscopical examination of surface pellicles by thin section showed the phage abortive infection to form a much broader zone than demonstrable in macroscopical examination, since under the black pellicle containing reduced metallic tellurite another tellurite-negative layer is hidden. The quickly growing mycobacteria in the peripheral zones of lytic plaques were either fully tellurite-positive or showed on the inside of the plaque a very narrow, hardly visible tellurite-negative border, microscopically similar to M. bovis BCG and H37RV. The possible utilization of tellurite cytoenzymatic reaction in differential diagnostics both of mycobacteria and mycobacterial phages is discussed.

Culture Media↗
PubMed1998

Out-of-pocket expenditures of outpatients receiving chemotherapy.

PURPOSE/OBJECTIVES: To examine the magnitude of out-of-pocket expenditures for patients undergoing chemotherapy in an outpatient clinic. DESIGN: Cross-sectional survey. SETTING: An urban outpatient chemotherapy clinic. SAMPLE: Convenience sample of 20 adult patients with cancer. METHODS: Birenbaum's Cost Interview Schedule was administered to patients as they awaited treatment in the chemotherapy clinic; demographic data were collected from patients' charts. MAIN RESEARCH VARIABLE: Out-of-pocket expenditures incurred during a one-month period of chemotherapy treatment. FINDINGS: Estimated out-of-pocket expenses, excluding lost income, ranged widely from $12-$3,130. CONCLUSIONS: Out-of-pocket expenses come from multiple sources over time and can be more costly than previously recognized. Extent of out-of-pocket expenditures may depend on treatment protocol, ease of symptom management, functional status, and nonclinical elements such as socioeconomic factors. Additional investigation can identify which patients are most vulnerable to excessive out-of-pocket expenses and who may be at risk for treatment delay or withdrawal because of difficulties in meeting expenses. IMPLICATIONS FOR NURSING PRACTICE: Recognition of the hidden costs incurred by patients with cancer as they undergo treatment enables nurses to anticipate the financial burden of illness, make necessary referrals, address quality-of-life issues because of financial distress, and avert critical delays in treatment related to overwhelming healthcare costs.

Adult↗
PubMed1981

The genetics of Drosophila subobscura populations. XVII. Further genic heterogeneity within electromorphs by urea denaturation and the effect of the increased genic variability on linkage disequilibrium studies.

Urea denaturation of allozymes was used to provide finer resolution of allelic states within classes of different electrophoretic mobility. This method gives perfectly repeatable results. About 170 isogenic strains for the O chromosome of Drosophila subobscura, derived from two natural populations, were constructed. Their gene arrangements were studied, as well as eight polymorphic genes located on the O chromosome (Est-5, Odh, Ao, ME, Xdh, Lap, Pept-1 and Acph). Crosses performed indicate that differences in urea sensitivity are genetically controlled by the same genes that control electrophoretic mobility. Twice as many alleles have been detected in comparison to the usual electrophoretic method. However, the effective number of alleles did not increase considerably. Studies of linkage disequilibria, by taking into account the finer resolution of allelic states, gave results nearly identical with those obtained in studies where the usual electrophoretic method was used. Although the power of the test is diminished, the absence of genic associations seems to indicate that there are no hidden linkage disequilibria in electrophoretic studies (because of consolidation effects of real alleles into few electromorph classes). The paucity of linkage disequilibria would indicate that there are no epistatic interactions such as those suggested in the model of FRANKLIN and LEWONTIN (1970).

Alleles↗
PubMed1996

Convergence Properties of High-order Boltzmann Machines.

The high-order Boltzmann machine (HOBM) approximates probability distributions defined on a set of binary variables, through a learning algorithm that uses Monte Carlo methods. The approximation distribution is a normalized exponential of a consensus function formed by high-degree terms and the structure of the HOBM is given by the set of weighted connections. We prove the convexity of the Kullback-Leibler divergence between the distribution to learn and the approximation distribution of the HOBM. We prove the convergence of the learning algorithm to the strict global minimum of the divergence, which corresponds to the maximum likelihood estimate of the connection weights, establishing the uniqueness of the solution. These theoretical results do not hold in the conventional Boltzmann machine, where the consensus function has first and second-degree terms and hidden units are used. Copyright 1996 Elsevier Science Ltd.

Journal Article↗
PubMed2000

Evaluation of antiretroviral drug efficacy for HIV-1 encephalitis in SCID mice.

OBJECTIVES: To compare the efficacy of the nucleoside reverse transcriptase inhibitors (NRTIs) abacavir, zidovudine (AZT), lamivudine (3TC), didanosine (ddI), and stavudine (d4T) to inhibit viral replication in brain macrophages. A severe combined immunodeficiency (SCID) mouse model of HIV-1 encephalitis (HIVE) was used to monitor spreading viral infection in the CNS. BACKGROUND: The development of antiretroviral therapies with CNS efficacy against neuroinvasive virus is important if eradication of HIV-1 can be achieved within critical "hidden reservoirs." METHODS: HIV-1-infected human monocyte-derived macrophages (MDMs) (after a single round of viral replication) were inoculated into the caudate and putamen of SCID mice. This resulted in the spreading of viral infection with a concomitant multinucleated giant cell encephalitis (astrogliosis, microglial activation, and neuronal injury). NRTIs were administered to animals at the time of intracerebral MDM inoculations and continued until the time of sacrifice. Antiretroviral effects were assessed by viral load and percentages of infected MDMs. RESULTS: In brains of SCID mice with HIVE, abacavir and lamivudine reduced HIV-1 p24 antigen-positive cells by 80% and 95%, respectively, whereas both decreased viral load by approximately 1 log. Zidovudine, didanosine, and stavudine showed variable effects. CONCLUSION: Abacavir and lamivudine showed significant antiretroviral activity in SCID mice with HIVE when compared with other NRTIs. The extrapolation of these results to humans with HIV-1 dementia awaits future investigations.

AIDS Dementia Complex↗
PubMedDate not supplied

Patterns of child maltreatment referrals among Asian and Pacific Islander families.

Much of the available data on Asian American families who become involved with the child welfare system relies on global ethnic categories, such as the category Asian/Pacific Islander. To explore the diversity of experience that is hidden by such categories, this article analyzes two years of child maltreatment referrals for Asian and Pacific Island families in Washington state. The study findings show that considerable variation exists within the Asian and Pacific Islander population with regard to child protection referrals. Although Asian Americans as a whole were less likely to be referred to child protective services than other groups, the within group picture that these data capture is considerably more complex. Some Asian/Pacific Islander ethnic groups, particularly those which have experienced higher levels of social and economic stress, were more at risk of child welfare involvement than other groups. Such findings underscore the need for child welfare policies and practice that are sensitive to the considerable variability within the Asian/Pacific Islander community.

Asian↗