40 research outputs found
Morphometry of muscular pulmonary arteries: with special reference to the effects of age and smoking
Structural changes in the pulmonary vessels are usually first
evident in the muscular pulmonary arteries. Current methods for
quantitating the media, intima and artery size are inadequate
because they produce measurements that are affected by artery
collapse/constriction or the irregular distribution of intimal
abnormality within and between vessels, or they are unacceptably
tedious. New techniques were developed in this study to overcome
these problems; using a semi-automatic digitising system
measurements are produced, directly from histological sections, of
medial and intimal area, and artery size is defined as total length
of internal elastic lamina (IEL).Technique validation was carried out on thirteen subjects with
a variety of cardio-pulmonary disorders. At an appropriate
magnification reproducibility of the measurements is excellent.
Although only cross-sectional arteries with a well-defined IEL
('digitisable') may be measured these are representative of the
total population.The relationship between medial area and artery size is a
curved one, best linearised by taking the square root of medial
area. This latter relationship was used to investigate the effect
of different tissue preparation procedures on the measurements
obtained, specifically by comparing slopes of the regression lines.
Complete arterial distension by an injection medium caused the IEL
to stretch, x 1.5. However, neither the pressure/method used for lung inflation/fixation nor the tissue embedding medium affected the
above relationship. Tissue shrinkage was considerable with paraffin
embedding/sectioning and negligible with glycol methacrylate in
which more arteries were considered 'digitisable'.A new method for expressing intimal abnormality was devised,
the Intima Index, namely intimal area expressed as a proportion of
the area enclosed by the IEL in its theoretically unwrinkled state.
Values range from >0 to ^1 indicating minimal through to total lumen
occlusion. Subjects are compared by calculating mean Intima Indices
for arteries sub-divided by size.The medial and intimal areas of cross-sectional but
'undigitisable' arteries may be obtained by simply delineating the
boundaries of intima-media, and media-adventitia. The total length
of the IEL in such arteries is readily obtained by multiplying the
length of the intima-media boundary by a factor based on a by-eye
estimate of the degree of lamina 'crinkling'.The effects of age and smoking on muscular pulmonary arteries
were studied in thirty-two resection specimens and twenty-three
autopsy specimens. The amount of medial muscle was unaffected by
age, sex or smoking habit, and varied considerably between subjects.
In small arteries it correlated with absolute weight of right
ventricle.In the autopsy group the amount of intimal abnormality,
although very varied, increased with age in all sizes of artery but
was most prominent in the smaller ones; contrary to previous reports no lobar differences were evident. These trends were
strongest in smokers.The resection group was unsuitable for this study, the results
suggesting that superimposed on the effects of age and smoking there
is a degree of intimal fibrosis which results either directly or
indirectly from the presence of the bronchial carcinoma itself
The contribution of metacognitions and attentional control to decisional procrastination
Earlier research has implicated metacognitions and attentional control in procrastination and self-regulatory failure. This study tested several hypotheses: (1) that metacognitions would be positively correlated with decisional procrastination; (2) that attentional control would be negatively correlated with decisional procrastination; (3) that metacognitions would be negatively correlated with attentional control; and (4) that metacognitions and attentional control would predict decisional procrastination when controlling for negative affect. One hundred and twenty-nine participants completed the Depression Anxiety Stress Scale 21, the Meta-Cognitions Questionnaire 30, the Attentional Control Scale, and the Decisional Procrastination Scale. Significant relationships were found between all three attentional control factors (focusing, shifting, and flexible control of thought) and two metacognitions factors (negative beliefs concerning thoughts about uncontrollability and danger, and cognitive confidence). Results also revealed that decisional procrastination was significantly associated with negative affect, all measured metacognitions factors, and all attentional control factors. In the final step of a hierarchical regression analysis only stress, cognitive confidence, and attention shifting were independent predictors of decisional procrastination. Overall these findings support the hypotheses and are consistent with the Self-Regulatory Executive Function model of psychological dysfunction. The implications of these findings are discussed
Malate plays a crucial role in starch metabolism, ripening, and soluble solid content of tomato fruit and affects postharvest softening
Despite the fact that the organic acid content of a fruit is regarded as one of its most commercially important quality traits when assessed by the consumer, relatively little is known concerning the physiological importance of organic acid metabolism for the fruit itself. Here, we evaluate the effect of modifying malate metabolism in a fruit-specific manner, by reduction of the activities of either mitochondrial malate dehydrogenase or fumarase, via targeted antisense approaches in tomato (Solanum lycopersicum). While these genetic perturbations had relatively little effect on the total fruit yield, they had dramatic consequences for fruit metabolism, as well as unanticipated changes in postharvest shelf life and susceptibility to bacterial infection. Detailed characterization suggested that the rate of ripening was essentially unaltered but that lines containing higher malate were characterized by lower levels of transitory starch and a lower soluble sugars content at harvest, whereas those with lower malate contained higher levels of these carbohydrates. Analysis of the activation state of ADP-glucose pyrophosphorylase revealed that it correlated with the accumulation of transitory starch. Taken together with the altered activation state of the plastidial malate dehydrogenase and the modified pigment biosynthesis of the transgenic lines, these results suggest that the phenotypes are due to an altered cellular redox status. The combined data reveal the importance of malate metabolism in tomato fruit metabolism and development and confirm the importance of transitory starch in the determination of agronomic yield in this species.Fil: Centeno, Danilo C.. Max Planck Institute Of Molecular Plant Physiology; AlemaniaFil: Osorio, Sonia. Max Planck Institute Of Molecular Plant Physiology; AlemaniaFil: Nunes Nesi, Adriano. Max Planck Institute Of Molecular Plant Physiology; AlemaniaFil: Bertolo, Ana L. F.. Cornell University; Estados UnidosFil: Carneiro, Raphael T.. Cornell University; Estados UnidosFil: Araújo, Wagner L.. Max Planck Institute Of Molecular Plant Physiology; AlemaniaFil: Steinhauser, Marie Caroline. Max Planck Institute Of Molecular Plant Physiology; AlemaniaFil: Michalska, Justyna. Max Planck Institute Of Molecular Plant Physiology; AlemaniaFil: Rohrmann, Johannes. Max Planck Institute Of Molecular Plant Physiology; AlemaniaFil: Geigenberger, Peter. Technische Universitat München; AlemaniaFil: Oliver, Sandra N.. Max Planck Institute Of Molecular Plant Physiology; AlemaniaFil: Stitt, Mark. Max Planck Institute Of Molecular Plant Physiology; AlemaniaFil: Carrari, Fernando Oscar. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación en Ciencias Veterinarias y Agronómicas. Instituto de Biotecnología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Rose, Jocelyn K. C.. Cornell University; Estados UnidosFil: Fernie, Alisdair R.. Max Planck Institute Of Molecular Plant Physiology; Alemani
Mechanisms of SARS-CoV-2 neutralization by shark variable new antigen receptors elucidated through X-ray crystallography
Acknowledgements This work was supported by the Chief Scientist Office, Scottish Government, Grant COV/ABN/20/01 (Elasmogen, Ltd.), a 2018 Prostate Cancer Foundation Challenge Award (AML), a 2013 Prostate Cancer Foundation Young Investigator Award (AML), NCI R01s CA237272, CA233562, and CA245922 (AML). WEM was supported by the NIH T32 HL007741 and JMT by the NIH T32 AI055433. JSM was funded by NIGMS R01 GM088790. HA was funded by NIGMS R35 GM118047 and NCI P01 CA234228. X-ray diffraction data were collected at the Northeastern Collaborative Access Team beamlines, which are funded by the US National Institutes of Health (NIGMS P30 GM124165). The Pilatus 6M detector on 24-ID-C beamline is funded by a NIH-ORIP HEI grant (S10 RR029205). We thank the Marco Pravetoni lab for providing training and access to the OctetRED96e for BLI experiments.Peer reviewedPublisher PD
Diagnostic properties of metabolic perturbations in rheumatoid arthritis
Introduction: The aim of this study was to assess the feasibility of diagnosing early rheumatoid arthritis (RA) by measuring selected metabolic biomarkers. Methods: We compared the metabolic profile of patients with RA with that of healthy controls and patients with psoriatic arthritis (PsoA). The metabolites were measured using two different chromatography-mass spectrometry platforms, thereby giving a broad overview of serum metabolites. The metabolic profiles of patient and control groups were compared using multivariate statistical analysis. The findings were validated in a follow-up study of RA patients and healthy volunteers. Results: RA patients were diagnosed with a sensitivity of 93% and a specificity of 70% in a validation study using detection of 52 metabolites. Patients with RA or PsoA could be distinguished with a sensitivity of 90% and a specificity of 94%. Glyceric acid, D-ribofuranose and hypoxanthine were increased in RA patients, whereas histidine, threonic acid, methionine, cholesterol, asparagine and threonine were all decreased compared with healthy controls. Conclusions: Metabolite profiling (metabolomics) is a potentially useful technique for diagnosing RA. The predictive value was without regard to the presence of antibodies against cyclic citrullinated peptides
Multiple strategies to prevent oxidative stress in Arabidopsis plants lacking the malate valve enzyme NADP-malate dehydrogenase
The nuclear-encoded chloroplast NADP-dependent malate dehydrogenase (NADP-MDH) is a key enzyme controlling the malate valve, to allow the indirect export of reducing equivalents. Arabidopsis thaliana (L.) Heynh. T-DNA insertion mutants of NADP-MDH were used to assess the role of the light-activated NADP-MDH in a typical C3 plant. Surprisingly, even when exposed to high-light conditions in short days, nadp-mdh knockout mutants were phenotypically indistinguishable from the wild type. The photosynthetic performance and typical antioxidative systems, such as the Beck–Halliwell–Asada pathway, were barely affected in the mutants in response to high-light treatment. The reactive oxygen species levels remained low, indicating the apparent absence of oxidative stress, in the mutants. Further analysis revealed a novel combination of compensatory mechanisms in order to maintain redox homeostasis in the nadp-mdh plants under high-light conditions, particularly an increase in the NTRC/2-Cys peroxiredoxin (Prx) system in chloroplasts. There were indications of adjustments in extra-chloroplastic components of photorespiration and proline levels, which all could dissipate excess reducing equivalents, sustain photosynthesis, and prevent photoinhibition in nadp-mdh knockout plants. Such metabolic flexibility suggests that the malate valve acts in concert with other NADPH-consuming reactions to maintain a balanced redox state during photosynthesis under high-light stress in wild-type plants
Rapid identification of causal mutations in tomato EMS populations via mapping-by-sequencing
The tomato is the model species of choice for fleshy fruit development and for the Solanaceae family. Ethyl methanesulfonate (EMS) mutants of tomato have already proven their utility for analysis of gene function in plants, leading to improved breeding stocks and superior tomato varieties. However, until recently, the identification of causal mutations that underlie particular phenotypes has been a very lengthy task that many laboratories could not afford because of spatial and technical limitations. Here, we describe a simple protocol for identifying causal mutations in tomato using a mapping-by-sequencing strategy. Plants displaying phenotypes of interest are first isolated by screening an EMS mutant collection generated in the miniature cultivar Micro-Tom. A recombinant F2 population is then produced by crossing the mutant with a wild-type (WT; non-mutagenized) genotype, and F2 segregants displaying the same phenotype are subsequently pooled. Finally, whole-genome sequencing and analysis of allele distributions in the pools allow for the identification of the causal mutation. The whole process, from the isolation of the tomato mutant to the identification of the causal mutation, takes 6-12 months. This strategy overcomes many previous limitations, is simple to use and can be applied in most laboratories with limited facilities for plant culture and genotyping