The effect of chronic ethanol on glutamate binding in human and rat brain

Quantitative autoradiographic techniques demonstrate that chronic alcohol administration causes a decrease in [3H]-glutamate binding to hippocampal N-methyl-D-aspartate (NMDA) receptors. A 14% decrease in [3H]-glutamate binding in the hippocampal CA1 region is seen both in the rat after five days of ethanol administration and in postmortem hippocampal tissues from alcoholics. In the rat, 24 hr ethanol withdrawal values are intermediate between control and alcohol binding levels. There was no significant effect of ethanol on [3H]-glutamate binding in the cortex or caudate.     

Leaf hydraulic conductance varies with vein anatomy across Arabidopsis thaliana wild‐type and leaf vein mutants

Leaf venation is diverse across plant species and has practical applications from paleobotany to modern agriculture. However, the impact of vein traits on plant performance has not yet been tested in a model system such as Arabidopsis thaliana. Previous studies analysed cotyledons of A. thaliana vein mutants and identified visible differences in their vein systems from the wild type (WT). We measured leaf hydraulic conductance (K_leaf), vein traits, and xylem and mesophyll anatomy for A. thaliana WT (Col‐0) and four vein mutants (dot3‐111 and dot3‐134, and cvp1‐3 and cvp2‐1). Mutant true leaves did not possess the qualitative venation anomalies previously shown in the cotyledons, but varied quantitatively in vein traits and leaf anatomy across genotypes. The WT had significantly higher mean K_leaf. Across all genotypes, there was a strong correlation of K_leaf with traits related to hydraulic conductance across the bundle sheath, as influenced by the number and radial diameter of bundle sheath cells and vein length per area. These findings support the hypothesis that vein traits influence K_leaf, indicating the usefulness of this mutant system for testing theory that was primarily established comparatively across species, and supports a strong role for the bundle sheath in influencing K_leaf.     

Diversity in spindle morphology in Arabidopsis root tip

A primary function of the spindle apparatus is to segregate chromosomes into two equal sets in a dividing cell. It is unclear whether spindles in different cell types play additional roles in cellular regulation. As a first step in revealing new functions of spindles, we investigated spindle morphology in different cell types in Arabidopsis roots in the wild-type and the cytokinesis defective1 (cyd1) mutant backgrounds. cyd1 provides cells larger than those of the wild type for testing the cell size effect on spindle morphology. Our observations indicate that cell type (shape), not cell size, is likely a factor affecting spindle morphology. At least three spindle types were observed, including small spindles with pointed poles in narrow cells, large barrel-shaped spindles (without pointed poles) in wide cells, and spindles intermediate in pole focus and size in other cells. We hypothesize that the cell-type-associated spindle diversity may be an integral part of the cell differentiation processes.Key words: spindle pole, microtubule, morphogenesis, cell type, metaphaseThe cellular apparatus for chromosome segregation during mitosis is typically described as a spindle composed of microtubules and microtubule-associated proteins. Research on the structure and function of the spindle is usually conducted under the assumption that spindles are structurally the same or alike in different cell types in an organism. If the assumption is true, it would indicate that either the intracellular conditions in different dividing cells are very similar or the assembly and maintenance of the spindle are insensitive to otherwise variable intracellular conditions. But experimental evidence related to this assumption is relatively sparse.The root tip in Arabidopsis, as in other higher plants, contains dividing cells of different shapes and sizes. These cells include both meristem initial and derivative cells, with the former and latter being proximal and distal to the quiescent center, respectively.¹ The diversity in dividing cells in the root tip provides an opportunity for testing whether the spindles also exhibit diversity in morphology. To visualize the spindles at the metaphase stage in the root tip cells, we conducted indirect immunofluorescence labeling of the β-tubulin in single cells prepared from wild-type Arabidopsis (in Col-0 background) root tips as previously described in references ² and ³. The spindles in cells of different morphologies were then observed under a confocal laser scanning microscope.³ Three types of spindle were detected. The first type (Fig. 1A) was the smallest in width and length and had the most-pointed poles among the three types. The second type (Fig. 1B) was wider and longer than the first type but with less-pointed poles than the first type. The third type (Fig. 1C) was similar in height to the second type but lacked the pointed poles. In fact, the third type is shaped more like a barrel than a spindle. The first type was found in cells narrow in the direction parallel to the equatorial plane of the spindle, a situation opposite to that of the third type whose cells were wide in the equatorial direction. The wide cells containing the barrel-shaped spindles likely belonged to the epidermal layer in the root tip.¹ The second type was found in cells intermediate in width. Examples of metaphase spindles morphologically resembling the three types of spindles in Arabidopsis root can also be found in a previous report by Xu et al. even although spindle diversity was not the subject of the report.⁴ In Xu et al.''s report, type 1- or 2-like metaphase spindles can be identified in Figures 2B and 3A, and type 3-like metaphase spindles can be identified in Figures 1A and 3B. These observations indicate that at least three types of spindles exist in the root cells.Open in a separate windowFigure 1Spindles in wild-type root cells. (A) Type-1 spindle. (B) Type-2 spindle. (C) Type-3 spindle. The spots without fluorescence signals in the middle of the spindles are where the chromosomes were located. Scale bar for all the figures = 20 µm.Open in a separate windowFigure 2Spindles in cyd1 root cells. (A) Type-1 spindle. Arrows indicate the upper and lower boundaries of the cell. (B and C) Two type-2 spindles. (D and E) Two type-3 spindles. (F) DAPI-staining image corresponding to (E), showing chromosomes at the equatorial plane. Scale bar for the images = 20 µm.The above observations suggest that either the cell size or the cell type (shape) might be a factor in the type of spindle found in a specific cell. To further investigate the relationship between cell morphology and spindle morphology, we studied metaphase spindles in root cells of the cytokinesis defective1 (cyd1) mutant.⁵ Because the root cells in cyd1 were larger than corresponding cells in the wild type, presumably due to abnormal polyploidization prior to the collection of the root cells,^5,6 this investigation might reveal a relationship between increasing cell size and altered spindle morphology. A pattern of different spindle types in different cell types similar to that in the wild type was observed in cyd1 (Fig. 2). Figures 2A–C show narrow cells that contained spindles with pointed poles even though the spindles differed in size and focus. Figure 2D shows a barrel-shaped spindle in a wide cell, resembling Figure 1C in overall appearance. The large number of chromosomes at metaphase (more than the diploid number of 10) in Figure 2F indicates that the cells in Figure 2 were polyploid. These figures thus demonstrate that the enlargement in cell size did not alter the pattern of types 1 and 2 spindles in narrow cells, as well as type 3 spindles in wide cells. Moreover, the edges of the spindles in Figure 2B and E were similarly distanced to the cell walls in the equatorial plane, and yet they differ greatly in shape with the former being type 2 and the latter being type 3. This finding argues against that the cell width in the equatorial direction dictates the spindle shape. On the other hand, the cells in Figure 2B and E are obviously of different types. Taken together, these observations suggest that the spindle diversity in both wild type and cyd1 is associated with cell-type diversity.It is unclear whether the different spindle types have different functions in their respective cell types, in addition to the usual role for chromosome segregation. One possibility is that, at the ensuing telophase, the pointed spindles result in compact chromosomal congregation at the poles whereas the barrel-shaped spindles result in loose chromosomal congregation at the poles, which in turn may differentially affect the shape of the subsequently formed daughter nuclei and their organization. Different nuclear shape and organization are likely to be integrated into the processes that confer cell differentiation.     

Outcome prediction in pneumonia induced ALI/ARDS by clinical features and peptide patterns of BALF determined by mass spectrometry

Background

Peptide patterns of bronchoalveolar lavage fluid (BALF) were assumed to reflect the complex pathology of acute lung injury (ALI)/acute respiratory distress syndrome (ARDS) better than clinical and inflammatory parameters and may be superior for outcome prediction.

Methodology/Principal Findings

A training group of patients suffering from ALI/ARDS was compiled from equal numbers of survivors and nonsurvivors. Clinical history, ventilation parameters, Murray''s lung injury severity score (Murray''s LISS) and interleukins in BALF were gathered. In addition, samples of bronchoalveolar lavage fluid were analyzed by means of hydrophobic chromatography and MALDI-ToF mass spectrometry (MALDI-ToF MS).Receiver operating characteristic (ROC) analysis for each clinical and cytokine parameter revealed interleukin-6>interleukin-8>diabetes mellitus>Murray''s LISS as the best outcome predictors. Outcome predicted on the basis of BALF levels of interleukin-6 resulted in 79.4% accuracy, 82.7% sensitivity and 76.1% specificity (area under the ROC curve, AUC, 0.853). Both clinical parameters and cytokines as well as peptide patterns determined by MALDI-ToF MS were analyzed by classification and regression tree (CART) analysis and support vector machine (SVM) algorithms. CART analysis including Murray''s LISS, interleukin-6 and interleukin-8 in combination was correct in 78.0%. MALDI-ToF MS of BALF peptides did not reveal a single identifiable biomarker for ARDS. However, classification of patients was successfully achieved based on the entire peptide pattern analyzed using SVM. This method resulted in 90% accuracy, 93.3% sensitivity and 86.7% specificity following a 10-fold cross validation (AUC = 0.953). Subsequent validation of the optimized SVM algorithm with a test group of patients with unknown prognosis yielded 87.5% accuracy, 83.3% sensitivity and 90.0% specificity.

Conclusions/Significance

MALDI-ToF MS peptide patterns of BALF, evaluated by appropriate mathematical methods can be of value in predicting outcome in pneumonia induced ALI/ARDS.     

Organization of the CTX prophage in environmental isolates of Vibrio mimicus

The organization of the CTX prophage in environmental strains of Vibrio mimicus was investigated. Sixteen hundred non-sucrose fermenting vibrios were examined for ctx gene by hybridization. Out of 1,600 isolates, 6 V. mimicus isolates contained ctxA gene. The organization of CTX prophage was determined by RFLP using ctxA probe. The CTX prophage integrated at a single site in V. mimicus genome which was present as a single copy flanked by at least a single RS element. Ribotype pattern revealed that a particular clone of V. mimicus acquired the CTXPhi in the aquatic environment. This study demonstrated that V. mimicus could act as a reservoir of CTXPhi in the aquatic environment.     

Critical factors influencing the occurrence of Vibrio cholerae in the environment of Bangladesh

The occurrence of outbreaks of cholera in Africa in 1970 and in Latin America in 1991, mainly in coastal communities, and the appearance of the new serotype Vibrio cholerae O139 in India and subsequently in Bangladesh have stimulated efforts to understand environmental factors influencing the growth and geographic distribution of epidemic Vibrio cholerae serotypes. Because of the severity of recent epidemics, cholera is now being considered by some infectious disease investigators as a "reemerging" disease, prompting new work on the ecology of vibrios. Epidemiological and ecological surveillance for cholera has been under way in four rural, geographically separated locations in Bangladesh for the past 4 years, during which both clinical and environmental samples were collected at biweekly intervals. The clinical epidemiology portion of the research has been published (Sack et al., J. Infect. Dis. 187:96-101, 2003). The results of environmental sampling and analysis of the environmental and clinical data have revealed significant correlations of water temperature, water depth, rainfall, conductivity, and copepod counts with the occurrence of cholera toxin-producing bacteria (presumably V. cholerae). The lag periods between increases or decreases in units of factors, such as temperature and salinity, and occurrence of cholera correlate with biological parameters, e.g., plankton population blooms. The new information on the ecology of V. cholerae is proving useful in developing environmental models for the prediction of cholera epidemics.     

The dependence of leaf hydraulic conductance on irradiance during HPFM measurements: any role for stomatal response?

This paper examines the dependence of whole leaf hydraulic conductance to liquid water (K(L)) on irradiance when measured with a high pressure flowmeter (HPFM). During HPFM measurements, water is perfused into leaves faster than it evaporates hence water infiltrates leaf air spaces and must pass through stomates in the liquid state. Since stomates open and close under high versus low irradiance, respectively, the possibility exists that K(L) might change with irradiance if stomates close tightly enough to restrict water movement. However, the dependence of K(L) on irradiance could be due to a direct effect of irradiance on the hydraulic properties of other tissues in the leaf. In the present study, K(L) increased with irradiance for 6 of the 11 species tested. Whole leaf conductance to water vapour, g(L), was used as a proxy for stomatal aperture and the time-course of changes in K(L) and g(L) was studied during the transition from low to high irradiance and from high to low irradiance. Experiments showed that in some species K(L) changes were not paralleled by g(L) changes. Measurements were also done after perfusion of leaves with ABA which inhibited the g(L) response to irradiance. These leaves showed the same K(L) response to irradiance as control leaves. These experimental results and theoretical calculations suggest that the irradiance dependence of K(L) is more consistent with an effect on extravascular (and/or vascular) tissues rather than stomatal aperture. Irradiance-mediated stimulation of aquaporins or hydrogel effects in leaf tracheids may be involved.     

Wastewater-grown duckweed may be safely used as fish feed

Duckweed has been used for the treatment of wastewater and as fish feed. A comparative study was carried out to determine (i) the efficacy of duckweed in treating hospital-based wastewater and (ii) the level of the microbial contamination of fish fed on wastewater-grown duckweed. There were two groups of ponds where fish farming was done. In one group of ponds (control ponds), duckweed that was grown using artificial fertilizer was used as fish feed; in another group (study ponds), wastewater-grown duckweed was used as fish feed. The faecal contamination of water, duckweed, and fish from study and control ponds were monitored by faecal coliform estimation. The presence of enteric pathogens among handlers, water, duckweed, and fish samples was also examined. It was observed that the faecal coliform counts of raw wastewater were 4.7 Log10 CFU/mL, which was reduced to <1 Log10 CFU/mL after treating with duckweed. There was no significant difference (P > 0.05) in faecal coliform counts in water collected from duckweed ponds and fish ponds of study and control areas. The wastewater-grown duckweed did not pose any health hazard to the handlers. These results demonstrated that the wastewater-treated duckweed may be safely used as fish feed.     

Novel aspects of systems biology and clinical cytomics.

The area of Cytomics and Systems Biology became of great impact during the last years. In some fields of the leading cytometric techniques it represents the cutting edge today. Many different applications/variations of multicolor staining were developed for flow- or slide-based cytometric analysis of suspensions and sections to whole animal analysis. Multispectral optical imaging can be used for studying immunological and tumorigenic processes. New methods resulted in the establishment of lipidomics as the systemic research of lipids and their behavior. All of these development push the systemic approach of the analysis of biological specimens to enhance the outcome in the clinic and in drug discovery programs.     

Multiplex analysis of cytokines in exhaled breath condensate.

BACKGROUND: To improve monitoring of lung diseases, we analyzed cytokines in exhaled breath condensate (EBC). The main challenge in measurement of cytokines in EBC is the low protein content, which requires concentration steps that conflict with the need for excessive fluid required by most commonly used kits. METHODS: Here, a multiplex bead array for the detection of interleukins (IL) -1beta, -6, -8, -10, TNF-alpha, and IL-12p70 was modified and validated for analysis in EBC samples. Furthermore, 33 healthy volunteers and 11 patients with acute lung injury were investigated. RESULTS: In patients with inflammatory lung diseases, cytokine levels for all investigated cytokines were higher in comparison to healthy smokers or healthy volunteers. DISCUSSION: Multiplexed immunoassays in highly sensitive approaches allow for cytokine detection in EBC. We found significant differences between patients and controls for all investigated cytokines.