Time-lapse analysis of cell death in mammalian and fungal cells

Time-lapse video microscopy was designed to follow the movement of single cells for an unlimited period of time under physiological conditions. The system is based on two inverted microscopes located in a CO(2) incubator and equipped with charge-coupled device cameras connected to the computer. Frames were recorded every minute and the subsequent video sequence was converted to database form. The system was applied to describe the movements of normal HaCaT cells and Pb-treated cells causing the so-called apoptotic dance during cell death. The apoptotic movement was also followed in high-osmolarity glycerol-type mitogen-activated protein kinase (MAPK) null mutant of Fusarium proliferatum, a filamentous fungus, during osmotic stress. The shortest (20 min) and most vigorous death movements were observed in apoptotic fungal cells subjected to salt stress. The necrotic process at higher Pb concentration (50 microM) took 2-3 h, whereas the apoptotic process at lower Pb concentrations lasted from minutes to days.

Hungarian web-based nationwide anaesthesia and intensive care data collection and reporting system: its development and experience from the first 5 yr

BACKGROUND

Annual data collection is obligatory in Hungary for every department in the fields of anaesthesia and intensive care. A new, web-based data-reporting system was introduced in Hungary in 2003. The present paper summarizes experience from the first 5 yr of its operation.

METHODS

The Information Technology Working Group of Hungarian Society of Anaesthesia and Intensive Care developed a data collection system, which was Internet-based, provided web surface for every accredited department, and used the integration of international code systems. The analysis mode summarized the data automatically at loco-regional, national, or both levels. In 2008, a questionnaire was sent to the users in order to evaluate the usefulness of, and user satisfaction with, the web-based system.

RESULTS

The examples of anaesthetic and intensive therapy workload activities reflect the status of the discipline in Hungary. There have been no significant changes in the total number of anaesthesias per year in the past 5 yr, except that the number of combined general and regional anaesthesias has been elevated by more than 30%. The physicians' workload has increased by 13.2% in relation to the total number of anaesthetic procedures per physician per year. In this field, our data have verified that the number of physicians has decreased in Hungary. On the basis of the opinion of the users, the web-based data collection system has increased the effectiveness and accuracy of annual data collection.

CONCLUSIONS

The developed web-based system is an effective tool for data collection. Its usefulness was also borne out by its users on the basis of experience from the first 5 yr.

Selective association of endogenous ouabain with subclinical organ damage in treated hypertensive patients

According to previous studies endogenous ouabain (EO) closely correlates with high blood pressure, congestive heart failure and kidney disease in humans. Our aims were to analyse associations between plasma, urinary EO level and various markers of cardiovascular damage in treated hypertensive patients. Forty-one adult patients with hypertension and/or diabetes mellitus (DM) and/or chronic kidney disease (CKD) were studied. We assessed plasma and urinary EO, pro-brain natriuretic peptide and catecholamines, profile of ambulatory blood pressure monitor and cardiovascular status by echocardiography and echo-tracking. The highest level of plasma EO (19.7±9.5 pmol l⁻¹) was measured in hypertensive patients with DM and CKD. The nighttime mean arterial blood pressure independently correlated with the level of plasma EO (P=0.004), while independent predictor of the β-stiffness of carotid artery was the urinary EO (P=0.011). Elevated level of EO was associated with nighttime blood pressure and subclinical organ damage in treated hypertensive patients, suggesting possible role of EO in the pathogenesis of impaired diurnal blood pressure rhythm and arterial stiffness.

Prehospital emergency care in Hungary: what can we learn from the past?

BACKGROUND

In Hungary, prehospital emergency medical services are provided by the National Ambulance Service. The 60(th) anniversary of the National Ambulance Service provides a good opportunity to give an overview of the current trends in prehospital emergency medical care in Hungary.

OBJECTIVES

In this report, a description of the organizational structure and the latest developments in the National Ambulance Service are described with the intention to highlight future directions in emergency medical services, as well as the influence of international trends in emergency patient care.

RESULTS

In Hungary, the ambulance cars are staffed by two or three crew members trained in rescue, stabilization of the patient's status, transport, and advanced care of traumatic and medical emergencies. There are three major levels of care provided by ambulance personnel: a basic level ambulance crew (Emergency Medical Technician Unit), a second level (Ambulance Officer Unit), and the highest level (Emergency Physician Unit). The personnel on the latter two units are trained in all aspects of Basic Life Support and Advanced Life Support procedures for prehospital emergency care. Following the latest international developments in medical rescue devices and guidelines, all staff are retrained yearly. Recently, private services for transportation for non-acute illnesses have been introduced, allowing the National Ambulance Service to concentrate on emergencies only.

CONCLUSIONS

Although the Hungarian Ambulance Service has a very long and meaningful past and a respected professional development, new challenges facing prehospital emergency care are inevitable and continuous development is necessary.

C1-inhibitor autoantibodies in SLE

The presence of anti-C1-inhibitor (anti-C1-INH) autoantibodies is a hallmark of acquired C1-inhibitor deficiency. However, only scarce data are available on their prevalence, diagnostic value, and/or significance in systemic lupus erythematosus (SLE). In a multicentre study, we determined the levels of autoantibodies to C1-inhibitor in sera from 202 patients with SLE and 134 healthy controls. Additional clinical and laboratory parameters, such as organ involvement, as well as anti-C1q, anti-double-stranded DNA antibody, erythrocyte sedimentation rate, C-reactive protein, C3 and C4 serum complement levels have been studied in patients. The level of anti-C1-INH IgG was significantly higher (p = 0.034) in SLE patients, than in the controls. A high anti-C1-INH level of ≥0.4 U/ml (mean of controls + 2 SD) was found in 17% of the patients, but in only 4% of the controls (p = 0.0003). The SLEDAI score was significantly higher (p = 0.048) and the duration of SLE was significantly longer (p = 0.0004) among patients with elevated anti-C1-INH levels compared with patients without this autoantibody (median disease duration 8 vs. 17 years, respectively). Anti-C1-INH level was not correlated with any other laboratory parameter or organ manifestation of the disease. These findings indicate that the anti-C1-INH level is higher in SLE patients than in healthy controls and furthermore, the anti-C1-INH level correlates with the duration and activity of the disease. Lupus (2010) 19, 634—638.

Lymphatic spread of mesenchymal renal tumor to metastatic parathymic lymph nodes in rat

Rat mesenchymal renal tumor cells (NeDe) transplanted under the kidney capsule of F344 rats resulted in metastases in the parathymic lymph nodes. Tumor cells were isolated from these tumor-bearing lymph nodes and 106 cells were implanted under the kidney capsule. Tumor growth after this implantation could be traced within six days. India ink was implanted to prove that there is a connection between the lymphatic vessels of the kidney capsule and the parathymic lymph nodes. The distribution of the radioligand 18FDG in different organs also provided evidence that the parathymic lymph nodes are the primary sites of metastatic tumor growth. Tumor growth was followed after staining sections of biopsies of normal, tumorous kidneys and parathymic lymph nodes embedded in paraffin. The progression of tumor formation was seen as a frontline between the healthy and tumor bearing tissue. This demarcation line was sharp at the beginning of the invasion and at the peripheral regions of the tumor, while the central region infiltrated into the healthy kidney tissue. The initial invasion gradually turned to an infiltration resulting in the disruption of the renal tissue, especially at the periphery. Accumulation of lipids and flow of blood to the lymphatic vessels was due to the lack of angiogenesis, leading to an increased pressure of the interstitial fluid. Interstitial damage ultimately led to the appearance of blood and the growth of tumor cells in parathymic lymph nodes. The kidney capsule-parathymic lymph node complex is proposed as a suitable metastatic model for the isolated in vivo examination of tumor development and for the analysis of secondary tumors.

Adlayer Structures Probed by Distance Tunnelling Spectroscopy for Au(111)/H2SO4 + Cu2+

We performed a series of distance tunnelling characteristics measurements for the system Au(111)/0.05 M H2SO4 + 1 mM Cu2+ to understand, if it is possible to map the liquid part of the double layer perpendicular to the electrode surface. We found that we probed the double layer in a distance range where we do not penetrate into the inner Helmholtz layer. Nevertheless, the tip is sufficiently close to the metal surface to address adlayer features showing sensitivity toward long-range ordered structures. The bias between the STM tip and the sample drops in the inner Helmholtz layer, and electronic overlap exists between the adsorbed layer and the metal surface. Molecular contributions to the electronic structure of ordered adlayers appear to be detectable. At larger distances from the surface the average barrier height was found to be about 1 eV, practically independent on the electrode potential.

The changing face of European healthcare education: the Hungarian experience

Throughout Europe, higher education is undergoing great changes in order to establish what is being called the European Higher Education Area (EHEA) based on the Bologna process. The goal being the establishment of a uniform, transparent and efficient development of professionals in a higher education system that can react in a flexible way to the changes in the labor market, and to the challenges presented by increasing globalization. The aim of this article is to provide an overview of the Bologna process and to give a summary of the implemented initial stages in the health care higher education of Hungary. As a consequence, the Hungarian higher education in healthcare has undergone considerable reforms to facilitate transition into this new system. The results indicate that the new structure in health sciences is not compatible with other way of European countries of introducing Bologna reforms, although the content of the former BSc curriculum still remained the same. MSc programs are still being discussed.

Far-from-constant mean curvature solutions of Einstein's constraint equations with positive Yamabe metrics

We establish new existence results for the Einstein constraint equations for mean extrinsic curvature arbitrarily far from constant. The results hold for rescaled background metric in the positive Yamabe class, with freely specifiable parts of the data sufficiently small, and with matter energy density not identically zero. Two technical advances make these results possible: A new topological fixed-point argument without smallness conditions on spatial derivatives of the mean extrinsic curvature, and a new global supersolution construction for the Hamiltonian constraint that is similarly free of such conditions. The results are presented for strong solutions on closed manifolds, but also hold for weak solutions and for compact manifolds with boundary. These results are apparently the first that do not require smallness conditions on spatial derivatives of the mean extrinsic curvature.

Liquid water confined in carbon nanochannels at high temperatures

Structure, hydrogen bonding, electrostatics, dielectric, and dynamical properties of liquid water confined in flat graphene nanochannels are investigated by molecular dynamics simulations. A wide range of temperatures (between 20 and 360 degrees C) have been considered. Molecular structure suffers substantial changes when the system is heated, with a significant loss of structure and hydrogen bonding. In such case, the interface between adsorbed and bulk-like water has a marked tendency to disappear, and the two preferential orientations of water nearby the graphite layers at room temperature are essentially merging above the boiling point. The general trend for the static dielectric constant is its reduction at high temperature states, as compared to ambient conditions. Similarly, residence times of water molecules in adsorbed and bulk-like regions are significantly influenced by temperature, as well. Finally, we observed relevant changes in water diffusion and spectroscopy along the range of temperatures analyzed.

Chemically Induced Carcinogenesis Affecting Chromatin Structure in Rat Hepatocarcinoma Cells

A new, chemically induced animal tumor cell line (HeDe) was established and characterized by its property of causing aggressively growing tumors in specific strain of rats and changes in the chromatin structure. Results show that (1) the nuclear material in nuclei of normal resting (G0) hepatocytes consists mainly of decondensed veil-like chromatin, chromosomes being clustered in six lobular domains; (2) nuclei of HeDe cells contain primarily supercoiled chromatin; or (3) the nuclear material of tumor cells undergoes apoptosis seen as apoptotic bodies. Heterogeneity of chromatin structures was expressed as contour/area ratio and was nine times higher in apoptotic cells and two times higher in tumor cells compared to resting cells.

Preapoptotic chromatin changes induced by ultraviolet B irradiation in human erythroleukemia K562 cells

Exponentially growing human erythroleukemia K562 cells were permeabilized and the dose dependent decrease of DNA synthesis rate was measured after ultraviolet (UV B, 290 nm) irradiation. Cells were able to overcome 2 and 5 J/m2 UV doses, partial recovery was observed at 15 J/m2, while at high (25 J/m2) UV dose replicative DNA synthesis remained suppressed. K562 cells were subjected to synchronization prior to and after UV irradiation (24 J/m2) and 18 fractions were collected by centrifugal elutriation. Cell cycle analysis by flow cytometry did not show early apoptotic cells after UV irradiation. The gradual increase in DNA content typical for non-irradiated cells was contrasted by an early S phase block between 2.2 and 2.4 C-values after UV irradiation. Cell cycle dependent chromatin changes after ultraviolet irradiation were seen as a fine fibrillary network covering the mainly fibrous chromatin structures and incompletely folded primitive chromosomes. Based on observations after UV irradiation and on earlier results with cadmium treatment and gamma irradiation, we confirm that typical chromatin changes characteristic to genotoxic agents can be recognized and classified.

First Report of Botrytis Blight Caused by Botrytis cinerea on Sweet Basil in Hungary

In Hungary, sweet basil (Ocimum basilicum L.) is an important medicinal and aromatic plant cultivated over a large area. During field surveys conducted in August and September of 2001 and 2002, significant blossom and leaf blight were observed in plant stands located near Budapest and in the northern region of Hungary at Herencsény. Incidence of disease occurrence ranged between 49 and 92%. Abundant grayish-brown mold consisting of mycelia and conidiophores was observed on necrotic flowers and upper leaves. The fungus was identified as Botrytis cinerea Pers.:Fr.. Conidia were one-celled, ovoid to elliptical, and measured 11.2 × 7.4 μm (7.5 to 15.0 × 5.0 to 10.0 μm). The fungus was isolated on Leonian malt media. In culture, small and large irregular sclerotia, as well as conidiophores, were produced abundantly. Size of large sclerotia ranged between 45 and 95 mm. Sclerotia were produced only in culture. Pathogenicity of two isolates originating from Herencsény was confirmed by spraying eight sweet basil potted plants with a conidial suspension (6.3 × 10⁵ conidia/ml) made from a pure culture. Two noninoculated plants served as controls. Half of the plants were wounded with needles to make incisions on the leaves and flower axes prior to the inoculation, while the remaining plants were directly sprayed. After inoculation, plants were kept in plastic bags in a greenhouse to maintain 90 to 100% relative humidity at 15 to 40°C. After 5 days, water-soaked chlorotic lesions appeared on the wounded leaves of the inoculated plants. After day 12, brown necrosis developed on the flowers of all inoculated plants. Flower axes often broke. Sporulation of the fungus was abundant. Wounding contributed to earlier appearance of the symptoms and more intensive disease development. To our knowledge, this is the first report of botrytis blight on sweet basil in Hungary. In Europe, the disease has been observed in Italy (1) and Greece (2). References: (1) A. Garibaldi et al. Plant Dis. 81:124, 1997. (2) C. D. Holevas et al. Benaki Phytopathol. Inst. Kiphissia, Athens 19:1, 2000.

Transition from Chromatin Bodies to Linear Chromosomes in Nuclei of Murine PreB Cells Synchronized in S Phase

Chromatin structures and individual interphase chromosomes escaping nuclei of reversibly permeabilized cells were analyzed in a cell cycle-dependent manner. Cells were synchronized by counterflow centrifugal elutriation. Individual interphase chromosomes became visible as distinct fibrous chromatin bodies from mid-S-phase, turning to elongated chromosomes by the end of S phase. Major interphase chromosomal forms include (1) mid-S-phase chromatin bodies at 3.0 C-value, (2) elongated chromatin bodies later in mid-S-phase (3.25 C-value), (3) chromatin bodies with head and leg portions later in S phase (3.5 C-value), (4) supercoiled ribbons later in S phase seen as twisted prechromosomes (3.7 C-value), and (5) end-S-phase elongated, bent prechromosomal structures (3.9 C-value). The first karyotype analysis of the earliest forms of chromosomes referred to as chromatin bodies was performed.

Supramolecular polymers based on the quadruplex formation of ditopic guanosine macromonomers in nonaqueous media

The formation of supramolecular polymeric aggregates with a molecular mass of 100 kDa in a nonaqueous solution from a telechelic dimer of isopropylidene guanosine in the presence of K(+) ions is reported. The possible structure of macromonomers resulting from the development of G4 quartets was deduced from DOSY NMR, circular dichroism spectra, and dynamic light scattering measurements.

Cell culture density dependent toxicity and chromatin changes upon cadmium treatment in murine pre-B-cells

Murine pre-B-cells grown in the presence of lower (1 microM) or higher (5 microM) concentration of cadmium chloride were separated into 13 fractions by centrifugal elutriation. The rate of DNA synthesis after cadmium treatment determined in permeable cells was dependent on cell culture density during cadmium treatment. Cell cycle analysis revealed a shift in the profile of DNA synthesis from replicative to repair DNA synthesis upon cadmium treatment. The study of the relationship between cell culture density and cell diameter at lower and higher cell densities in the presence of 1 microM cadmium chloride concentration showed that a. at 5 x 10(5) cell/ml or lower densities cells were shrinking indicating apoptotic changes, b. at higher cell culture densities the average cell size increased, c. the treatment of cells with low CdCl(2) concentration (1 microM) at higher cell culture density (>5 x 10(5) cell/ml) did not change significantly the average cell diameter. At 5 microM cadmium concentration and higher cell culture densities (>5 x 10(5) cell/ml) the average cell size decreased in each elutriated fraction. Most significant inhibition of cell growth took place in early S phase (2.0-2.5 C value). Apoptotic chromatin changes in chromatin structure after cadmium treatment were seen as large extensive disruptions, holes in the nuclear membrane and stickiness of incompletely folded chromosomes.

Supranucleosomal Organization of Chromatin Fibers in Nuclei ofDrosophilaS2 Cells

Earlier, the interphase chromatin structures could not be visualized due to the stickiness of the nuclear material. We have reduced stickiness by the reversal of permeabilization allowing the isolation and microscopic imaging of interphase chromatin structures. By using a high resolution of synchronization, collecting 36 elutriation fractions, we show that major intermediates of chromatin condensation include: (a) decondensed veillike chromatin at the unset of the S phase (2.0-2.2 C-value), (b) polarization of veiled chromatin (2.2-2.6 C), (c) fibrous chromatin (2.6-3.0 C), chromatin bodies (3.0-3.3 C), early precondensed chromosomes (3.3-3.6). The compaction of Drosophila chromosomes did not reach that of the mammalian cells in the final stage of condensation (3.6-4.0 C). Drosophila chromosomes consist of smaller units called rodlets. Results demonstrate that nucleosomal chromatin ("beads on string") does not form a solenoid structure; rather, the topological arrangement consists of meandering and plectonemic loops.

Molecular Dynamics Simulation of Liquid Water Confined inside Graphite Channels: Dielectric and Dynamical Properties

Electric and dielectric properties and microscopic dynamics of liquid water confined between graphite slabs are analyzed by means of molecular dynamics simulations for several graphite-graphite separations at ambient conditions. The electric potential across the interface shows oscillations due to water layering, and the overall potential drop is about -0.28 V. The total dielectric constant is larger than the corresponding value for the bulklike internal region of the system. This is mainly due to the preferential orientations of water nearest the graphite walls. Estimation of the capacitance of the system is reported, indicating large variations for the different adsorption layers. The main trend observed concerning water diffusion is 2-fold: on one hand, the overall diffusion of water is markedly smaller for the closest graphite-graphite separations, and on the other hand, water molecules diffuse in interfaces slightly slower than those in the bulklike internal areas. Molecular reorientational times are generally larger than those corresponding to those of unconstrained bulk water. The analysis of spectral densities revealed significant spectral shifts, compared to the bands in unconstrained water, in different frequency regions, and associated to confinement effects. These findings are important because of the scarce information available from experimental, theoretical, and computer simulation research into the dielectric and dynamical properties of confined water.

Evaluation of palatal saliva flow rate and oral manifestations in patients with Sjögren's syndrome

OBJECTIVE

The purpose of this study was to describe the oral properties of Sjögren's syndrome (SS), including the determination of palatal saliva (PS) flow rate.

SUBJECTS AND METHODS

Forty-nine SS patients and 43 healthy controls participated. Subjective symptoms were recorded and clinical assessments of the oral mucosal, dental and periodontal status were made. Unstimulated whole saliva (WS) and PS flow rates, the number of decayed, missing and filled teeth (DMF-T number), the gingival bleeding index (GBI) and the periodontal probing depth (PPD) were determined.

RESULTS

Despite the decrease in the flow rate of WS in SS patients, PS was not different from those of the controls (1.57 +/- 1.02 and 1.35 +/- 2.5 microl cm(-2) min(-1), respectively). GBI (20.0% vs. 10.5%, respectively), DMF-T (27.1 +/- 6.12 vs. 23.0 +/- 6.99, respectively) and PPD (2.28 +/- 1.09 mm vs. 1.82 +/- 0.73 mm, respectively) were higher in SS compared with the controls (P < 0.05). DMF-T and PPD showed a positive correlation with anti-SSA and/or anti-SSB antibody positivity in the serum (P < 0.05).

CONCLUSIONS

Data of the present study suggest that the subjective feeling of xerostomia in SS patients is the result of a decrease in the volume of the whole saliva, and not of the viscous PS. Correlation of DMF-T and PPD with autoantibody positivity reveals that the oral health status of SS patients may be associated with the general autoimmune process.

Regional variations in community consumption of antibiotics in Hungary, 1996-2003

AIMS

To study regional differences and identify determinants of antibiotic consumption in ambulatory care in Hungary.

METHODS

Regional distribution-based antibiotic sales data were converted into a number of defined daily doses (DDD) per 1000 inhabitant-days. Correlations were assessed with the Spearman rank test.

RESULTS

There were large and stable interregional differences in antibiotic consumption. They were associated with socio-economic determinants, e.g. the population receiving free access to medicines and receiving regular social assistance.

CONCLUSIONS

More detailed studies are needed to better understand the determinants of antibiotic use in these specific patient populations and to identify additional determinants at regional level.

Targeting dsRNA-specific single-chain Fv antibody fragments to different cellular locations in Nicotiana tabacum L

Expression of antibodies or antibody fragments in plants is a useful tool for producing active antibody derivatives for diagnostic or pharmaceutical purposes as well as for immunomodulation. We investigated the effect of cellular expression site on the stability and yield of double-stranded RNA (dsRNA)-specific single-chain Fv-fragments (scFv) in transgenic tobacco. Two antibodies (J2 and P6) belonging to the V23(J558) heavy chain variable gene family but differing in the light chain variable domain were used. scFvs were targeted to the cytoplasm - with or without anchoring them in the plasma membrane -, into the endoplasmic reticulum (ER) and to the apoplast. Although high mRNA concentrations were detected in all cases, scFv proteins accumulated only when scFvs were made ER-resident by appropriate signal sequences. When the ER retention signal was removed to allow scFv-secretion to the apoplast, no scFv-proteins were detected. Despite the strong homology of the VH-sequences of J2 and P6 antibodies, only P6 provided a stable scFv scaffold for intracytoplasmic expression. J2-scFv could not be stabilised either by adding a C-terminal stabilisation signal or by anchoring the protein on the cytoplasmic side of the plasma membrane (PM). It was found that dsRNA-specific J2-scFvs are active in vivo and enhance Potato Virus Y induced symptoms in infected tobacco. This is the first report describing the expression and biological effect of RNA-specific antibodies in plants.

Common Pathway of Chromosome Condensation in Mammalian Cells

Chromatin folding in the interphase nucleus is not known. We compared the pattern of chromatin condensation in Indian muntjac, Chinese hamster ovary, murine pre B, and K562 human erythroleukemia cells during the cell cycle. Fluorescent microscopy showed that chromosome condensation follows a general pathway. Synchronized cells were reversibly permeabilized and used to isolate interphase chromatin structures. Based on their structures two major categories of intermediates were distinguished: (1) decondensed chromatin and (2) condensed chromosomal forms. (1) Chromatin forms were found between the G1 and mid-S phase involving veil-like, supercoiled, fibrous, ribboned structures; (2) condensing chromosomal forms appeared in the late-S, G2, and M phase, including strings, chromatin bodies, elongated pre-chromosomes, pre-condensed chromosomes, and metaphase chromosomes. Results demonstrate that interphase chromosomes are clustered in domains; condensing interphase chromosomes are linearly arranged. Our results raise questions related to telomer sequences and to the chemical nature of chromosome connectivity.

Molecular simulation of liquid water confined inside graphite channels: Thermodynamics and structural properties

We carried out molecular dynamics simulations to describe the properties of water inside a narrow graphite channel. Two stable phases were found: a low-density one made of water clusters adsorbed on the graphite sheets and a liquid one that fills the entire channel, forming several layers around a bulk-like region. We analyzed the interfacial structure, orientational order, water residence times in several regions, and hydrogen bonding of this last water phase, calculating also a quantity of electrochemical interest, the probability of electron tunneling through interfacial water. The results are in good qualitative agreement with the available experimental data.

Circadian and extracircadian exploration during daytime hours of circulating corticosterone and other endocrine chronomes

During 7 consecutive days, blood and several tissues were collected during daytime working hours only, three times per day at 4-h intervals from inbred Wistar rats, which had been previously standardized for 1 month in two rooms on a regimen of 12 h of light (L) alternating with 12 h of darkness (LD12:12). In one room, lights were on from 09:00 to 21:00 and in the other room, lights were on from 21:00 to 09:00 (DL12:12; reversed lighting regimen). This setup provides a convenient design to study circadian and extracircadian variations over long (e.g., 7-day) spans. Prior checking of certain circadian rhythms in animals reared in the room on reversed lighting (DL) as compared with animals in the usual (LD) regimen provided evidence that the 180 degrees phase-shift had occurred. These measurements were limited to the circadian (and not extended to infradian) variation. As marker rhythm, the core temperature of a subsample of rats was measured every 4 h around the clock (by night as well as by day) before the start of the 7-day sampling. An antiphase of the circadian rhythm in core temperature was thus demonstrated between rats in the LD vs. DL rooms. A sex difference in core temperature was also found in each room. A reversed rhythm in animals kept in DL and an antiphase between rats kept in DL vs. LD was again shown for the circulating corticosterone rhythm documented in subsamples of 8 animals of each sex sampled around the clock during the first approximately 1.5 day of the 7-day sampling. The findings were in keeping with the proposition that sampling rats at three timepoints 4 h apart during daytime from two rooms on opposite lighting regimens allows the assessment of circadian changes, the daytime samples from animals kept on the reversed lighting regimen accounting for the samples that would have to be obtained by night from animals kept in the room with the usual lighting regimen. During the 7-day-long follow-up, circadian and extracircadian spectral components were mapped for serum corticosterone, taking into account the large day-to-day variability. A third check on the synchronization of the animals to their respective lighting regimen was a comparison (and a good agreement) between studies carried out earlier on the same variables and the circadian results obtained on core temperature and serum corticosterone in this study as a whole. The present study happened to start on the day of the second extremum of a moderate double magnetic storm. The study of any associations of corticosterone with the storm is beyond our scope herein, as are the results on circulating prolactin, characterized by a greater variability and a larger sex difference than corticosterone. Sex differences and extracircadian aspects of prolactin and endothelin determined in the same samples are reported elsewhere, as are results on melatonin. Prior studies on melatonin were confirmed insofar as a circadian profile is concerned by sampling on two antiphasic lighting regimens, as also reported elsewhere. Accordingly, a circadian map for the rat will eventually be extended by the result of this study and aligned with other maps with the qualification of the unassessed contribution in this study of a magnetic storm.

Chronomics, neuroendocrine feedsidewards and the recording and consulting of nowcasts--forecasts of geomagnetics

A multi-center four-hourly sampling of many tissues for 7 days (00:00 on April 5-20:00 to April 11, 2004), on rats standardized for 1 month in two rooms on antiphasic lighting regimens happened to start on the day after the second extremum of a moderate double magnetic storm gauged by the planetary geomagnetic Kp index (which at each extremum reached 6.3 international [arbitrary] units) and by an equatorial index Dst falling to -112 and -81 nT, respectively, the latter on the first day of the sampling. Neuroendocrine chronomes (specifically circadian time structures) differed during magnetically affected and quiet days. The circadian melatonin rhythm had a lower MESOR and lower circadian amplitude and tended to advance in acrophase, while the MESOR and amplitude of the hypothalamic circadian melatonin rhythm were higher during the days with the storm. The circadian parameters of circulating corticosterone were more labile during the days including the storm than during the last three quiet days. Feedsidewards within the pineal-hypothalamic-adrenocortical network constitute a mechanism underlying physiological and probably also pathological associations of the brain and heart with magnetic storms. Investigators in many fields can gain from at least recording calendar dates in any publication so that freely available information on geomagnetic, solar and other physical environmental activity can be looked up. In planning studies and before starting, one may gain from consulting forecasts and the highly reliable nowcasts, respectively.

Chronomics reveal and quantify circadian rhythmic melatonin in duodenum of rats

A circadian rhythm is documented in duodenal melatonin in rats, peaking 16.8 hours after light onset. This component is more readily detected after log10-transformation of the data. It differs between male and female rats, females having a larger circadian amplitude and an earlier acrophase. The circadian rhythm in duodenal melatonin is also found to lead that of pineal melatonin. The results are qualified by the presence at the start of mapping of the second extremum of a double magnetic storm.

Chronomics: circadian lead of extrapineal vs. pineal melatonin rhythms with an infradian hypothalamic exploration

A circadian rhythm is documented for plasma, pineal, and hypothalamic melatonin of male and female rats kept on staggered lighting regimens. Log[_10]-transformation of the data usually normalizes, when need be, the distribution of residuals from the 24-hour cosine curve fits. A tentative circadian acrophase chart is presented that shows a lead in circadian acrophase of duodenal over pineal melatonin. The use of antiphasic lighting regimens facilitates circadian studies that can be carried out for several days, thereby allowing the assessment of infradian components such as a circasemiseptan variation in hypothalamic melatonin documented herein. The results are qualified by the presence of a second extremum of a double magnetic storm at the start of mapping.

Continuous-time random-walk theory of interfering diffusion and chemical reaction with an application to electrochemical impedance spectra of oxidized Zr-1%Nb

A microscopic theory is developed for the interplay of diffusion and chemical reaction and the results are compared with electrode impedance measurements on an oxide electrode. The theory is based on the ideas of continuous-time random walk and accounts for the interference of diffusion and recombination of the charge carriers in the oxide. The treatment results in a dispersive diffusivity with two time constants, one of them corresponding to the random walk, the other to the reaction. Combining this diffusivity with the Warburg electrode admittance expression, which refers to cases where the rate-limiting step is diffusion in a semi-infinite medium bounded by a plane, an admittance function is obtained. The phase angle is found to be higher than 45 degrees distinguishing it from the Gerischer impedance which was developed for a related problem. The oxides were produced by hydrothermal oxidation of Zr-l%Nb alloy, a metal used as cladding material for nuclear fuel elements. The electrode impedance spectra of Zr/Zr-oxide electrodes in aqueous SO(3) (2-) solutions were taken at various anodic voltages between 1 Hz and 100 kHz and temperatures between 278 and 333 K. The theoretical admittance functions could be successfully compared with the observed spectra. Both the functional forms and the fitted parameter values support our theory which is also in keeping with Macdonald's point-defect model.