Fluctuating asymmetry of the normal facial skeleton.

The purpose of this study was to produce reliable estimations of fluctuating facial asymmetry in a normal population. Fifty-four computed tomography (CT) facial models of average-looking and symmetrical Chinese subjects with a class I occlusion were used in this study. Eleven midline landmarks and 12 pairs of bilateral landmarks were digitized. The repeatability of the landmark digitization was first evaluated. A Procrustes analysis was then used to measure the fluctuating asymmetry of each CT model, after all of the models had been scaled to the average face size of the study sample. A principal component analysis was finally used to establish the direction of the fluctuating asymmetries. The results showed that there was excellent absolute agreement among the three repeated measurements. The mean fluctuating asymmetry of the average-size face varied at each anthropometric landmark site, ranging from 1.0mm to 2.8mm. At the 95% upper limit, the asymmetries ranged from 2.2mm to 5.7mm. Most of the asymmetry of the midline structures was mediolateral, while the asymmetry of the bilateral landmarks was more equally distributed. These values are for the average face. People with larger faces will have higher values, while subjects with smaller faces will have lower values.

Effects of nitrogen-deficiency on efficiency of light-harvesting apparatus in radish.

Nitrogen starvation has been stated to reduce chlorophyll a and accessory pigments, decrease photosynthetic efficiency, as well as modify chloroplast thylakoid membranes. However, the impact of N-deficiency on light-dependent reactions of photosynthesis has not been well understood. In this study, efficiency and structure of light-harvesting complex under N-deficiency conditions were investigated in two radish cultivars (Raphanus sativus var. sativus 'Fluo HF1' and 'Suntella F1'). Light-dependent reactions of photosynthesis were investigated by measuring in vivo chlorophyll a prompt fluorescence signal. Acquired data were utilised in two ways: by plotting fast induction curves and calculating OJIP-test biophysical parameters. Detailed analysis of difference curves as well as OJIP-test results showed that major disturbances were associated with photosystem II and its subunits, including decoupling of light-harvesting complexes, dysfunction of oxygen-evolving complex, and reaction centres inactivation. The maximum quantum yield of photosystem II primary photochemistry was severely restricted, causing an inhibition in electron transport through successive protein complexes in the thylakoid membrane. Structural changes were demonstrated by recording images using Transmission Electron Microscopy (TEM). TEM investigations showed intensive starch accumulation under N-deficiency. Rare thylakoid stacks distributed in tiny layers of stroma around grains and chloroplast periphery were observed in cells of N-deficient plants. The application of principal component analysis (PCA) on OJIP-test results allowed characterizing the dynamics of stress response and separating parameters according to their influence on plants stress response. 'Suntella F1' genotype was found to be more sensitive to nitrogen deficiency as compared to 'Fluo HF1' genotype.

Mechanisms of inhibitory effects of polycyclic aromatic hydrocarbons in photosynthetic primary processes in pea leaves and thylakoid preparations.

Inhibitory effects of polycyclic aromatic hydrocarbons (PAHs) on plants were studied in pea leaves in order to elucidate the mechanisms of action of PAHs such as naphthalene (Naph) and phenanthrene (Phen) on activity of photosystem II (PSII). The changes in different Chl fluorescence parameters were calculated on the basis of Chl fluorescence induction curves. H2 O2 content was measured in leaf homogenates with the luminol-dependent chemiluminescence method. We demonstrated that following PAH treatment, total energy dissipation (DI0 /ABS) and amount of QB -non-reducing complexes of PSII significantly increased. Non-photochemical quenching (NPQ) also increased, when weak oxidative stress after PAH application developed. In leaves, a two-step increase in H2 O2 was found with time of incubation in the presence of PAHs, which may be associated with damage to the lipid bilayer of the plasma membrane and then violation of lipid bilayer membranes of cell organelles. A hypothesis for the mode of action of PAHs is provided that involves the role of ROS, membrane permeability and associated functional changes in PSII.

Association of Relationship between Periodontal Disease and Cardiovascular Disease.

The present study was undertaken to determine the relationship between periodontal and cardiovascular disease. Previous studies have shown some co-relation between the two conditions. We included 186 patients divided into four groups. First two Groups (A1 & A2) were the patients with cardiac disease (100 in numbers) whilst Groups (B1 & B2) (86 in numbers) were treated as controls (without cardiac disease). Following markers of periodontal disease were assessed - plaque index, calculus index, gingival and periodontal index. Markers of cardiovascular disease included were LDL, HDL, total cholesterol and CRP. Ramfjords periodontal index was used to assess the extent of periodontal disease. In the present study there was a significant increase in CRP levels in Group A1 (CVD + PD) compared to controls and overall the two cardiac groups showed a significant increase in CRP compared to controls. There was a non-significant change in lipid profile markers (LDL, HDL and total cholesterol). Periodontal Disease Index (PDI) was also increased in Group A1 compared to other groups except Group B1 and overall in cardiac groups compared to non-cardiac (PD) groups. In this study no correlation between periodontal and cardiovascular disease was found. This may be due intake of statins by few patients in Group A with a confirmed diagnosis of cardiovascular disease.

Novel parameters of global and regional mitral annulus geometry in man: comparison between normals and organic mitral regurgitation, before and after mitral valve repair.

AIMS: The mitral annulus (MA) saddle shape is complex but vital for a normal functioning mitral apparatus. Although conventional parameters of MA geometry such as area and height are helpful, they fall short of describing its complex regional geometry. METHODS AND RESULTS: In this prospective study, novel parameters of MA curvature and torsion were derived from three-dimensional (3D) transoesophageal echocardiography. These quantitative indices were computed in 15 patients with normal valves (age 53 ± 8 years) and in 15 patients with organic significant mitral regurgitation (MR, age 66 ± 11 years), before and after mitral valve repair (MVR). The MA was traced and modelled in mid- and end-systole. Curvature and torsion were computed at 500 points across the MA to derive regional and global indices. Overall, patients with organic MR presented the smallest global curvature and torsion; this decrease in curvature and torsion reflects a loss of tonicity of the MA tissue. These changes were largely corrected with MVR surgery, to higher values, compared with normals. The regional analysis revealed similar trends. The maximal MA curvature was found to be at the MA 'anterior horn', whereas the MA 'posterior horn' had the lowest curvature values. CONCLUSION: Novel MA parameters of curvature and torsion can be computed from 3D echocardiography and provide quantitative characteristics of dynamic regional MA geometry. In patients with organic MR, the reduced regional and global curvatures improve following surgical MVR. These quantitative parameters may help further refine the quantitative description of MA geometry in various mitral valve pathologies and after MVR.

The primal sagittal plane of the head: a new concept.

To assess facial form, one has to determine the size, position, orientation, shape, and symmetry of the different facial units. Many of these assessments require a frame of reference. The customary coordinate system used for these assessments is the 'standard anatomical frame of reference', a three-dimensional Cartesian system made by three planes: the sagittal, the axial, and the coronal. Constructing the sagittal plane seems simple, but because of universal facial asymmetry, it is complicated. Depending on the method one selects, one can build hundreds of different planes, never knowing which one is correct. This conundrum can be solved by estimating the sagittal plane a patient would have had if his or her face had developed symmetrically. We call this the 'primal sagittal plane'. To estimate this plane we have developed a mathematical algorithm called LAGER (Landmark Geometric Routine). In this paper, we explain the concept of the primal sagittal plane and present the structure of the LAGER algorithm.

Algorithm for planning a double-jaw orthognathic surgery using a computer-aided surgical simulation (CASS) protocol. Part 2: three-dimensional cephalometry.

Three-dimensional (3D) cephalometry is not as simple as just adding a 'third' dimension to a traditional two-dimensional cephalometric analysis. There are more complex issues in 3D analysis. These include how reference frames are created, how size, position, orientation and shape are measured, and how symmetry is assessed. The main purpose of this article is to present the geometric principles of 3D cephalometry. In addition, the Gateno-Xia cephalometric analysis is presented; this is the first 3D cephalometric analysis to observe these principles.

Assessment of phytotoxicity of anthracene in soybean (Glycine max) with a quick method of chlorophyll fluorescence.

A decrease in photosynthetic efficiency may indicate the toxic effects of environmental pollutants on higher plants. Measurement of chlorophyll (Chl) a fluorescence to assess the performance of photosystem II (PSII) was used as an bioindicator of toxicity of the polycyclic aromatic hydrocarbon (PAH) anthracene (ANT) in soybean plants. The results revealed that ANT treatment caused a reduction in quantum yield of PSII, damage to the oxygen evolving complex, as well as a significant reduction in performance index of PSII. However, change in performance index was more prominent, and it seems that the performance index is a more sensitive parameter to environmental contaminants. Moreover, a change in heterogeneity of PSII was also observed. The number of active reaction centres decreased with increasing concentration of ANT, as secondary plastoquinone reducing centres were converted into non-reducing centres, and PSIIα centres were converted into PSIIß and PSIIγ centres. The influence of ANT on PSII heterogeneity could be an important reason for reductions in the PSII performance.

Analysis of elevated temperature-induced inhibition of photosystem II using chlorophyll a fluorescence induction kinetics in wheat leaves (Triticum aestivum).

Wheat is the major crop plant in many parts of the world. Elevated temperature-induced changes in photosynthetic efficiency were studied in wheat (T. aestivum) leaves by measuring Chl a fluorescence induction kinetics. Detached leaves were subjected to elevated temperature stress of 35 °C, 40 °C or 45 °C. Parameters such as Fv/Fm, performance index (PI), and reaction centre to absorbance ratio (RC/ABS) were deduced using radial plots from fluorescence induction curves obtained with a plant efficiency analyser (PEA). To derive precise information on fluorescence induction kinetics, energy pipeline leaf models were plotted using biolyzer hp3 software. At 35 °C, there was no effect on photosynthetic efficiency, including the oxygen-evolving complex, and the donor side of PSII remained active. At 40 °C, activity was reduced by 14%, while at 45 °C, a K intermediate step was observed, indicating irreversible damage to the oxygen-evolving complex. This analysis can be used to rapidly screen for vitality and stress tolerance characteristics of wheat growing in the field under high temperature stress.

High salt stress in coupled and uncoupled thylakoid membranes: a comparative study.

The effect of high salt concentration on photosystem II (PS II) electron transport rates and chlorophyll a fluorescence induction kinetics was investigated in coupled and uncoupled spinach thylakoid membranes. With increase in salt concentration, the rates of electron transport mediated by PS II and the F(v)/F(m) ratio were affected more in uncoupled thylakoids as compared to coupled thylakoid membranes. The uncoupled thylakoid membranes seemed to behave like coupled thylakoid membranes at high NaCl concentration (approximately 1 M). On increasing the salt concentration, the uncoupler was found to be less effective and Na+ probably worked as a coupling enhancer or uncoupling suppressor. We suggest that positive charge of Na+ mimics the function of positive charge of H+ in the thylakoid lumen in causing coupled state. The function of NaCl (monovalent cation) could be carried out by even lower concentration of Ca2+ (divalent cation) or Al3+ (trivalent cation). We conclude that this function of NaCl as coupling enhancer is not specific, and in general a positive charge is required for causing coupling in uncoupled thylakoid membranes.

Characterization of an rpoN mutant of Mesorhizobium ciceri.

AIMS: To study the genetic basis of C(4)-dicarboxylate transport (Dct) in relation to symbiotic nitrogen fixation in Mesorhizobium ciceri. METHODS AND RESULTS: A Tn5-induced mutant strain (TL16) of M. ciceri, unable to grow on C(4)-dicarboxylates, was isolated from the wild-type strain TAL 620. The mutant lacked activities of the enzymes, which use C(4)-dicarboxylates as substrate. The sequencing of the 3.2kb EcoRI fragment, which was the site of Tn5 insertion, revealed three complete and two partial open reading frames. In the mutant, Tn5 interrupted the rpoN gene, of which only one copy was there. Complementation and biochemical studies suggest that the M. ciceri rpoN activity is required for C(4)-Dct, maturation of bacteroids and symbiotic nitrogen fixation. The fine structure of the ineffective nodules produced by TL16 on Cicer arietinum L changed in comparison with those produced by the wild type. CONCLUSIONS: The mutant strain TL16 suffered a disruption in the rpoN gene. Only one copy of rpoN gene is present in M. ciceri. The mutation abolishes Dct activity. It additionally abolishes the symbiotic nitrogen fixation activity of the bacteroids in the nodules. SIGNIFICANCE AND IMPACT OF THE STUDY: This first document in M. ciceri shows that a functional rpoN gene is essential for the transport of dicarboxylic acids and symbiotic nitrogen fixation.

Inorganic anions induce state changes in spinach thylakoid membranes.

The role of cations in excitation energy distribution between the two photosystems of photosynthesis is well established. This paper provides evidence, for the first time, for an important role of anions in the regulation of distribution of absorbed light energy between the two photosystems. Inorganic anions caused redistribution of energy more in favour of photosystem I, as judged from measurements of chlorophyll a fluorescence transients, rates of electron transport in low light and 77 K fluorescence emission spectra: the Fv/Fm ratio was decreased by inorganic anions even in the presence of DCMU, the PS II electron transport was decreased whereas PS I electron transport was increased and the F735 (77 K emission from PS I)/F685 (77 K emission from PS II) ratio was increased. Such changes were observed with inorganic anions having different valencies (Cl- , SO4(2-), PO4(3-)): the higher the valency of the inorganic anion, the more the energy transferred towards PS I. Change in the valency of the inorganic anions thus regulates distribution of absorbed light energy between the two photosystems. However, organic anions like acetate, succinate, and citrate caused no significant changes in the Fv/Fm ratio, and in rates of PS I and PS II electron transport, showing their ineffectiveness in regulating light energy distribution.

Mg(2+)-induced lipid phase transition in thylakoid membranes is reversed by anions.

Effect of anions on thylakoid membrane fluidity as measured by rotational correlation time, order parameter (by ESR spectroscopy) and fluorescence polarization was studied. The data in the present study offer proof that Mg(2+)-induced rigidity of thylakoid membranes could be reversed by anions like bicarbonate and chloride. Anions were found to play a role in structural reorganization of thylakoid membranes.