Changes In Physiological State Research Articles

A CONTINUOUSLY UPDATED HYBRID BLOOD GAS MODEL FOR VENTILATED PATIENTS

SOPAVent (Simulation of Patients under Artificial Ventilation) is a blood gas model for ventilated patients in intensive care units. In this paper, a continuously updated blood gas model based on SOPAVent is developed and extended to simulate patients' states from a stable to an unstable status. The changes in the patient's physiological state are simulated by updating the shunt and relative dead space in the patient model. The model was validated against blood gas measurements from real patients during a 7-hour period and with changes to the ventilator settings. Results show that, with a selector based on a time criterion, the autonomous model can represent the real patient with a changing physiological state and give good blood gas predictions.

Repressing the expression of the SUCROSE NONFERMENTING-1-RELATED PROTEIN KINASE gene in pea embryo causes pleiotropic defects of maturation similar to an abscisic acid-insensitive phenotype.

The classic role of SUCROSE NONFERMENTING-1 (Snf1)-like kinases in eukaryotes is to adapt metabolism to environmental conditions such as nutrition, energy, and stress. During pea (Pisum sativum) seed maturation, developmental programs of growing embryos are adjusted to changing physiological and metabolic conditions. To understand regulation of the switch from cell proliferation to differentiation, SUCROSE NONFERMENTING-1-RELATED PROTEIN KINASE (SnRK1) was antisense repressed in pea seeds. Transgenic seeds show maturation defects, reduced conversion of sucrose into storage products, lower globulin content, frequently altered cotyledon surface, shape, and symmetry, as well as occasional precocious germination. Gene expression analysis of embryos using macroarrays of 5,548 seed-specific genes revealed 183 differentially expressed genes in two clusters, either delayed down-regulated or delayed up-regulated during transition. Delayed down-regulated genes are related to mitotic activity, gibberellic acid/brassinosteroid synthesis, stress response, and Ca2+ signal transduction. This specifies a developmentally younger status and conditional stress. Higher gene expression related to respiration/gluconeogenesis/fermentation is consistent with a role of SnRK1 in repressing energy-consuming processes in maturing cotyledons under low oxygen/energy availability. Delayed up-regulated genes are mainly related to storage protein synthesis and stress tolerance. Most of the phenotype resembles abscisic acid (ABA) insensitivity and may be explained by reduced Abi-3 expression. This may cause a reduction in ABA functions and/or a disconnection between metabolic and ABA signals, suggesting that SnRK1 is a mediator of ABA functions during pea seed maturation. SnRK1 repression also impairs gene expression associated with differentiation, independent from ABA functions, like regulation and signaling of developmental events, chromatin reorganization, cell wall synthesis, biosynthetic activity of plastids, and regulated proteolysis.

Concanavalin A-captured Glycoproteins in Healthy Human Urine

Both the urinary proteome and its glycoproteome can reflect human health status, and more directly, functions of kidney and urinary tracts. Because the high abundance protein albumin is not N-glycosylated, the urine N-glycoprotein enrichment procedure could deplete it, and urine proteome could thus provide a more detailed protein profile in addition to glycosylation information especially when albuminuria occurs in some kidney diseases. In terms of describing the details of urinary proteins, the urine glycoproteome is even a better choice than the proteome itself. Pooled urine samples from healthy volunteers were collected and acetone-precipitated for proteins. N-Linked glycoproteins enriched with concanavalin A affinity purification were separated and analyzed by SDS-PAGE-reverse phase LC/MS/MS or two-dimensional LC/MS/MS. A total of 225 urinary proteins were identified based on two-hit criteria with reliability over 97% for each peptide. Among these proteins, 94 were identified in previous urine proteome works, 150 were annotated as glycoproteins in Swiss-Prot, and 43 were predicted as glycoproteins by NetNGlyc 1.0. A number of known biomarkers and disease-related glycoproteins were identified. Because changes in protein quantity or the glycosylation status can lead to changes in the concanavalin A-captured glycoprotein profile, specific urine glycoproteome patterns might be observed for specific pathological conditions as multiplex urinary biomarkers. Knowledge of the urine glycoproteome is important in understanding kidney and body function.

Measuring randomness by leave-one-out prediction error. Analysis of EEG after painful stimulation

A parametric approach, to measure randomness in time series, is presented. Time series are modelled by a kernel machine performing regularized least squares and the leave-one-out (LOO) error is used to quantify unpredictability. On analyzing simulated data sets, we find that structure in data leads to a minimum of the LOO error as the regularizing parameter is varied. We consider electroencephalographic signals from migraineurs and healthy humans, after painful stimulation and use the proposed approach to detect changes of physiological state and to find differences between the response from patients and healthy subjects. As painful stimulus causes organization of the local activity in the cortex, EEG series become more predictable after stimulation. This phenomenon is less evident in patients: the inadequate cortical response to pain in migraineurs separates patients from controls with a probability close to 0.005 .

General Anesthesia Improves Fetal Cerebral Oxygenation without Evidence of Subsequent Neuronal Injury

Anesthetic exposure during pregnancy is viewed as a relatively routine medical practice. However, recent rodent studies have suggested that common anesthetic agents can damage the developing brain. Here we assessed this claim in a higher order species by exposing previously instrumented near-term pregnant sheep at gestational day 122 (+/-1) to a combination of midazolam, sodium thiopental, and isoflurane at clinically relevant doses and means of anesthetic delivery (i.e., active ventilation). Four hours of maternal general anesthesia produced an initial increase in fetal systemic oxygenation and a sustained increase in fetal cerebral oxygenation, as determined by in utero near-infrared spectroscopy. Postexposure monitoring failed to identify changes in physiologic status that could be injurious to the fetal brain. Finally, through the histologic assessment of noninstrumented sheep at the same gestational time point, we found no evidence for a direct fetal neuro-toxic effect of our triple-drug regimen. Collectively, these results appear to corroborate the presumed safety of inhalational anesthetic use during pregnancy.

The application of micro-FTIR spectroscopy to analyze nutrient stress-related changes in biomass composition of phytoplankton algae

Micro-Fourier transform infrared (FTIR) spectroscopy was used to study changes in spectral features of three species of Cyanobacteria ( Microcystis aeruginosa, Croococcus minutus, and Nostoc sp.) and two Bacillariophyceae ( Cyclotella meneghiniana, and Phaeodactylum tricornutum) in response to nutrient stress. The change of physiological state of the cells was followed during a 4-week starvation period on the basis of physiological key parameters and by means of FTIR spectroscopy. Changes in the integrated FTIR bands of cell spectra assigned to proteins, lipids, carbohydrates and silicate were used to calculate relative biomass composition. The results show that short-term acclimatization become visible at first in pigmentation and photosynthetic efficiency, whereas changes in biomass composition reflect long term modulation in the metabolism. Simultaneous monitoring of short term and long term stress acclimatization showed evidence that the metabolic strategies to cope with increasing nutrient limitation are highly species-specific. This species-specificity can only be resolved in natural phytoplankton samples by single cell techniques. The results show that the FTIR technique has the potential to become applicable for the determination of single cell biomass composition from natural phytoplankton communities.

Rapid change in energy status in fighting animals: causes and effects of strategic decisions

Energetic costs of fighting, such as high lactate or low glucose, have been shown in a range of species to correlate with the decisions made by each opponent, particularly the decision by one opponent, the ‘loser’, to end the fight by ‘giving up’. Studies based on complete fights of differing duration, however, do not provide information on the changes in the physiological correlates of fighting that may take place during the course of the encounter, or how these changes may influence the capability and decisions of the contestants. We interrupted fights between hermit crabs, Pagurus bernhardus, at specific points, and related energy status to the preceding activities. Costs rose quickly with a rapid accumulation of lactic acid in attackers and declining muscular glycogen in defenders. Changes in physiological status appeared much earlier than the changes in behaviour that they may have caused. Furthermore, some physiological changes might have been an effect, rather than the cause, of fight decisions.

Changes in a pattern of HMW-DNA fragmentation accompany differentiation and ageing of plant cells

Nuclear DNA is arranged into loop domains by periodical attachment of chromatin fibers to nuclear matrix at highest level of chromatin compactisation. Chromatin loops represent the basic structural components of higher order chromatin folding, which are maintained during cell cycle and in differentiated cells. An increasing number of evidences suggests strong relationship between chromatin structure compactisation and functional activity of cell nucleus. We showed previously that regular DNA cleavage into high molecular weight (HMW) DNA fragments can be induced in intact nuclei, resulting in formation of ~300 kb and 50–100 kb fragments. The patterns of induced cleavage were essentially similar both in intact and high-salt-extracted nuclei suggesting that HMW-DNA fragments represent DNA loop domains (or their associates). Biochemical properties of induced HMW-DNA cleavage suggest involvement of matrix-associated topoisomerase II in excision of DNA loop domains. We demonstrated further that patterns of HMW-DNA cleavage are distinct in plant tissues differed on proliferative activity and differentiation status. The least fragmentation was found in the embryos of dry quiescent seeds, whereas the induction of growth and development was accompanied by increase in HMW-DNA fragmentation. The study of cell nuclei during natural and accelerated ageing of rye seeds demonstrated that loss of germination capacity was associated with decreased excision of chromatin loop domains. Taken together, our data demonstrate that changes in physiological status of plant tissues are accompanied with the changes in patterns of HMW-DNA fragmentation. The HMW-DNA fragments are generated by the scaffold-associated topo II-like endonuclease activity that cleaves nuclear DNA probably at the positions of its attachment to nuclear scaffold. We hypothesize that HMW-DNA cleavage activity is related to some DNA metabolic processes in cell nuclei and is necessary for maintaining active physiological status of plant tissues.

Cortical and Autonomic Correlates of Visual Selective Attention in Introverted and Extraverted Children

Abstract. We investigated the performance on a selective attention task in two groups of 8- to 12-year-old healthy children being characterized as extraverted and introverted, respectively. During task performance EEG-activity was recorded to investigate differential effects on a specific selection-related potential, the N2b. Cardiac activity was recorded continuously before, during and after task performance. Spectral energy was computed for three distinguishable frequency bands corresponding with a low (LF), mid- (MF), and high-frequency (HF) component in heart rate variability (HRV). The extraverted children were found to show greater perceptual sensitivity in response to irrelevant information. They also exhibited a greater N2b-component while showing significantly greater decreases in, particularly, the LF- and MF-power of HRV during task performance as compared to baseline periods. The magnitude of the N2b and the task-related decreases in LF-power of HRV were found to correlate significantly with the degree of extraversion and task performance, as well as with each other. The findings are discussed in the light of how selective attention and changes in physiological state may be related to the children's temperament.

Gene Expression Programs during Brassica oleracea Seed Maturation, Osmopriming, and Germination Are Indicators of Progression of the Germination Process and the Stress Tolerance Level

During seed maturation and germination, major changes in physiological status, gene expression, and metabolic events take place. Using chlorophyll sorting, osmopriming, and different drying regimes, Brassica oleracea seed lots of different maturity, stress tolerance, and germination behavior were created. Through careful physiological analysis of these seed lots combined with gene expression analysis using a dedicated cDNA microarray, gene expression could be correlated to physiological processes that occurred within the seeds. In addition, gene expression was studied during early stages of seed germination, prior to radicle emergence, since very little detailed information of gene expression during this process is available. During seed maturation expression of many known seed maturation genes, such as late-embryogenesis abundant or storage-compound genes, was high. Notably, a small but distinct subgroup of the maturation genes was found to correlate to seed stress tolerance in osmoprimed and dried seeds. Expression of these genes rapidly declined during priming and/or germination in water. The majority of the genes on the microarray were up-regulated during osmopriming and during germination on water, confirming the hypothesis that during osmopriming, germination-related processes are initiated. Finally, a large group of genes was up-regulated during germination on water, but not during osmopriming. These represent genes that are specific to germination in water. Germination-related gene expression was found to be partially reversible by physiological treatments such as slow drying of osmoprimed seeds. This correlated to the ability of seeds to withstand stress.

Effect of dietary restriction, pregnancy, and fetal type on intestinal cellularity and vascularity in Columbia and Romanov ewes.

The objectives of this study were to evaluate intestinal cellularity and vascularity in mature ewes in response to dietary restriction and pregnancy status and to quantify the response of these variables to increased nutrient demand of fetal growth. In Exp. 1, 28 mature Dorset x crossbred white-faced ewes (61.6+/-1.8 kg initial BW) were fed a pelleted, forage-based diet. Treatments were arranged in a 2 x 3 factorial, with dietary restriction (60% restriction vs. 100% maintenance for respective states of pregnancy) and pregnancy status (nonpregnant, NP; d 90 and 130) as main effects. Dietary treatments were initiated on d 50 of gestation and remained at 60 or 100% maintenance throughout the experiment. Nonpregnant ewes were fed dietary treatments for 40 d. In Exp. 2, four Romanov ewes were naturally serviced (Romanov fetus and Romanov dam; R/R); two Romanov embryos per recipient were transferred to four Columbia recipients (Romanov fetus and Columbia recipient; R/C), and three Columbia ewes were naturally serviced (Columbia fetus and Columbia dam; C/C). In Exp. 1, dietary restriction and pregnancy status interacted with regard to maternal jejunal DNA concentration (P < 0.01), with restricted ewes having a greater DNA concentration (mg/g; fresh basis) at d 130. Vascularity (percentage of total tissue area) in the jejunum was increased (P < 0.06) as a result of dietary restriction and pregnancy status. Total microvascular volume ofjejunal tissue was not altered by dietary restriction and increased (P < 0.01) at d 130 of pregnancy. In Exp. 2, R/R ewes had less (P < 0.09) DNA (g) in the jejunum compared with R/C and C/C ewes. Jejunal vascularity (%) was increased (P < 0.05) in R/R ewes compared with R/C or C/C ewes, whereas total jejunal microvascular volume remained unchanged. These data demonstrate intestinal vascular density responds to changes in diet and physiological state. In addition, pregnancy increased total jejunal microvascular volume.

Development of Biomarkers Based on Diet-Dependent Metabolic Serotypes: Concerns and Approaches for Cohort and Gender Issues in Serum Metabolome Studies

Mathematical models that reflect the effects of dietary restriction (DR) on the sera metabolome may have utility in understanding the mechanisms of DR and in applying this knowledge to human epidemiological studies. Previous studies demonstrated both the feasibility of identifying biomarkers through metabolome analysis and the validity of our approach in independent cohorts of 6-month-old male and female ad libitum fed or DR rats. Cross-cohort studies showed that cohort-specific effects distorted the dataset. The present study extends these observations across the entire sample set, thereby validating our markers independently of specific cohorts. Metabolites originally identified in males were examined in females and vice-versa. DR's effect on the metabolome is partially gender-specific and is modulated by environmental factors. DR reduces inter-gender differences in the metabolome. Univariate statistical methods showed that 56/93 metabolites in the female samples and 39/93 metabolites in the male samples were significantly altered (using our previous cut-off criteria of p < or = 0.2) by DR. The metabolites modulated by DR present a wide spectrum of concentration, redox reactivity and hydrophilicity, suggesting that our serotype is broadly representative of the metabolome and that DR has broad effects on the metabolome. These studies, coupled with those in the preceding and following reports, also highlight the utility for consideration of the metabolome as a network of metabolites using appropriate data analysis approaches. The inter-cohort and inter-gender differences addressed herein suggest potential cautions, and potential approaches, for identification of multivariate biomarker profiles that reflect changes in physiological status, such as a metabolism that predisposes to increased risk of neoplasia.

Gcn4p and novel upstream activating sequences regulate targets of the unfolded protein response.

Eukaryotic cells respond to accumulation of unfolded proteins in the endoplasmic reticulum (ER) by activating the unfolded protein response (UPR), a signal transduction pathway that communicates between the ER and the nucleus. In yeast, a large set of UPR target genes has been experimentally determined, but the previously characterized unfolded protein response element (UPRE), an upstream activating sequence (UAS) found in the promoter of the UPR target gene KAR2, cannot account for the transcriptional regulation of most genes in this set. To address this puzzle, we analyzed the promoters of UPR target genes computationally, identifying as candidate UASs short sequences that are statistically overrepresented. We tested the most promising of these candidate UASs for biological activity, and identified two novel UPREs, which are necessary and sufficient for UPR activation of promoters. A genetic screen for activators of the novel motifs revealed that the transcription factor Gcn4p plays an essential and previously unrecognized role in the UPR: Gcn4p and its activator Gcn2p are required for induction of a majority of UPR target genes during ER stress. Both Hac1p and Gcn4p bind target gene promoters to stimulate transcriptional induction. Regulation of Gcn4p levels in response to changing physiological conditions may function as an additional means to modulate the UPR. The discovery of a role for Gcn4p in the yeast UPR reveals an additional level of complexity and demonstrates a surprising conservation of the signaling circuit between yeast and metazoan cells.

Hyperhydricity of Micropropagated Shoots: A Typically Stress-induced Change of Physiological State

Hyperhydricity of micropropagated shoots, formerly called vitrification, undoubtedly results from growth and culture conditions, subjectively reputated as stressing factors: wounding, infiltration of soft culture medium, generally of a high ionic strength, rich in nitrogen and in growth regulators in a special balance, in a humid and gaseous confined atmosphere. Stress is (objectively) defined as a disruption of homeostasis resulting from a constraint escaping the usual flexibility of metabolism. It induces another temporary (reversible) or definitive (irreversible) thermodynamic physiological state. The state-change concept developed by Strasser (1988) and Strasser and Tsimilli-Michael (2001) is applicable to the phenomenon of hyperhydricity. An appraisal of the redox capacities of hyperhydrated shoots together with a study of some enzymic activities that catalyse pentose phosphate and glycolytic pathways has indeed shown that such shoots have evolved towards a temporary state of lower differentiation or a juvenile state with a sufficient activity to survive and to defend themselves.

Macronutrient Selection in Experimental Animals

To address the question of how animals choose diets from an array of nutritionally different foods, researchers have designed experiments in which animals are provided with separate sources of the three macronutrients, protein, fat and carbohydrate. These experiments are useful for investigating the neuroanatomical and neurochemical mechanisms involved in food choice, as well as for assessing the effects of changes in physiological status (e.g., pregnancy; lactation and increased energy expenditure) or disease states (e.g., diabetes; and obesity) on nutrient intakes.

Stoichiometric Modelling for Physiological State Changes Monitoring in Bioprocesses

Abstract This paper deals with the monitoring of physiological state changes that may occur during a culture of a single micro-organism. It rests on a partial measurement of component concentrations in the reactor and of the input and output flows and utilises a stoichiometric approach to model biochemical reactions involved by the culture. We propose to define the basic reaction structure from component compositions and from calculability conditions of the stoichiometric matrix. A given physiological state is associated with a set of basic reactions. The monitoring of a system is then derived from the obtained model by using a bank specialised unknown input observer.

Persistence of individually distinctive display patterns in fatigued side-blotched lizards ( Uta stansburiana )

Iguanian lizards perform conspicuous species-typical push-up displays, which are used in territory advertisement, threat, and courtship contexts. Subtle individually distinctive differences in push-up characteristics have been suggested to play a role in the recognition of social partners. However, if the structure of push-ups is responsive to changing physiological states then their capacity to promote recognition may be limited. The current study evaluated whether the push-ups performed while in an experimentally imposed state of fatigue by male side-blotched lizards (Uta stansburiana), retain the individually distinctive characteristics apparent in rested lizards. We found repeatable among-individual differences in the duration and the relative height of push-up components. Repeatability values did not change consistently between the rested and fatigued conditions, nor when both conditions were pooled, indicating that these push-up characteristics do not change with fatigue. Similarly, discriminant functions that were generated using push-ups from one state assigned push-ups performed in an alternate state to the correct individuals. Furthermore, when analyzed independently of individual identity, the values of display parameters examined in the current study did not change significantly between states, and discriminant function analysis could not reliably classify push-ups to the correct state. Taken together the results show that individually distinctive push-up characteristics are robust to effects of fatigue, consistent with their suggested role in social recognition. In the future, video playback experiments can test whether lizards utilize the signature-like characteristics of push-ups to discriminate among individuals.

Studying the visceral physiology of tadpoles through their naturally transparent abdominal walls

We propose using anuran tadpoles with naturally transparent abdominal skin to study the visceral physiology of amphibian larvae under microgravity. The transparency of the abdominal wall in certain tadpoles enables one to evaluate the basal physiological state and temporal changes in viscera from their movements without any invasive treatment. In order to validate our experimental design, the intestinal motility and heart rate of Rhacophorus tadpoles were examined as indices of physiological responses to stepwise changes in temperature.

A Hybrid Approach for the Monitoring of Physiological State Changes

This paper deals with the monitoring of biological states that may occur during a culture of micro-organisms. A hybrid dynmuic model is proposed. Each mode of the associated automaton is associated with a set of activated reactions which characterises a given biological state. The monitoring of a system described by such a model needs to evaluate the transition which is triggered on and when it is. The proposed solution deeply utilises the a priori knowledge, this contained in the hybrid model, and doesn't need the specific growth rate estimation. It is developed in this paper considering that the whole state is measured and the matrix of the yield coefficients is known

Physiologic data acquisition system and database for the study of disease dynamics in the intensive care unit.

To describe a real-time, continuous physiologic data acquisition system for the study of disease dynamics in the intensive care unit. Descriptive report. A 16-bed pediatric intensive care unit in a tertiary care children's hospital. A total of 170 critically ill or injured pediatric patients. None. None. We describe a computerized data acquisition and analysis system for the study of critical illness and injury from the perspective of complex dynamic systems. Both parametric (1 Hz) and waveform (125-500 Hz) signals are recorded and analyzed. Waveform data include electrocardiogram, respiration, systemic arterial pressure (invasive and noninvasive), central venous pressure, pulmonary arterial pressure, left and right atrial pressures, intracranial pressure, body temperature, and oxygen saturation. Details of the system components are explained and examples are given from the resultant physiologic database of signal processing algorithms and signal analyses using linear and nonlinear metrics. We have successfully developed a real-time, continuous physiologic data acquisition system that can capture, store, and archive data from pediatric intensive care unit patients for subsequent time series analysis of dynamic changes in physiologic state. The physiologic signal database generated from this system is available for analysis of dynamic changes caused by critical illness and injury.