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1.
Staphylococci in healthy and diseased animals   总被引:2,自引:1,他引:1  
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Ohne Zusammenfassung
Oenothera nanella healthy and diseased
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4.
Notch signalling is an evolutionarily highly conserved signalling mechanism governing differentiation and regulating homeostasis in many tissues. In this review, we discuss recent advances in our understanding of the roles that Notch signalling plays in the vasculature. We describe how Notch signalling regulates different steps during the genesis and remodelling of blood vessels (vasculogenesis and angiogenesis), including critical roles in assigning arterial and venous identities to the emerging blood vessels and regulation of their branching. We then proceed to discuss how experimental perturbation of Notch signalling in the vasculature later in development affects vascular homeostasis. In this review, we also describe how dysregulated Notch signalling, as a consequence of direct mutations of genes in the Notch pathway or aberrant Notch signalling output, contributes to various types of vascular disease, including CADASIL, Snedden syndrome and pulmonary arterial hypertension. Finally, we point out some of the current knowledge gaps and identify remaining challenges in understanding the role of Notch in the vasculature, which need to be addressed to pave the way for Notch-based therapies to cure or ameliorate vascular disease.  相似文献   

5.
The primary function of the skin is to protect the body for unwanted influences from the environment. The main barrier of the skin is located in the outermost layer of the skin, the stratum corneum. The stratum corneum consists of corneocytes surrounded by lipid regions. As most drugs applied onto the skin permeate along the lipid domains, the lipid organization is considered to be very important for the skin barrier function. It is for this reason that the lipid organization has been investigated quite extensively. Due to the exceptional stratum corneum lipid composition, with long chain ceramides, free fatty acids and cholesterol as main lipid classes, the lipid organization is different from that of other biological membranes. In stratum corneum, two lamellar phases are present with repeat distances of approximately 6 and 13 nm. Moreover the lipids in the lamellar phases form predominantly crystalline lateral phases, but most probably a subpopulation of lipids forms a liquid phase. Diseased skin is often characterized by a reduced barrier function and an altered lipid composition and organization. In order to understand the aberrant lipid organization in diseased skin, information on the relation between lipid composition and organization is crucial. However, due to its complexity and inter-individual variability, the use of native stratum corneum does not allow detailed systematic studies. To circumvent this problem, mixtures prepared with stratum corneum lipids can be used. In this paper first the lipid organization in stratum corneum of normal and diseased skin is described. Then the role the various lipid classes play in stratum corneum lipid organization and barrier function has been discussed. Finally, the information on the role various lipid classes play in lipid phase behavior has been used to interpret the changes in lipid organization and barrier properties of diseased skin.  相似文献   

6.
The primary function of the skin is to protect the body for unwanted influences from the environment. The main barrier of the skin is located in the outermost layer of the skin, the stratum corneum. The stratum corneum consists of corneocytes surrounded by lipid regions. As most drugs applied onto the skin permeate along the lipid domains, the lipid organization is considered to be very important for the skin barrier function. It is for this reason that the lipid organization has been investigated quite extensively. Due to the exceptional stratum corneum lipid composition, with long chain ceramides, free fatty acids and cholesterol as main lipid classes, the lipid organization is different from that of other biological membranes. In stratum corneum, two lamellar phases are present with repeat distances of approximately 6 and 13 nm. Moreover the lipids in the lamellar phases form predominantly crystalline lateral phases, but most probably a subpopulation of lipids forms a liquid phase. Diseased skin is often characterized by a reduced barrier function and an altered lipid composition and organization. In order to understand the aberrant lipid organization in diseased skin, information on the relation between lipid composition and organization is crucial. However, due to its complexity and inter-individual variability, the use of native stratum corneum does not allow detailed systematic studies. To circumvent this problem, mixtures prepared with stratum corneum lipids can be used. In this paper first the lipid organization in stratum corneum of normal and diseased skin is described. Then the role the various lipid classes play in stratum corneum lipid organization and barrier function has been discussed. Finally, the information on the role various lipid classes play in lipid phase behavior has been used to interpret the changes in lipid organization and barrier properties of diseased skin.  相似文献   

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Studies on aerobic bacterial flora of faecal samples from healthy and diarrhoeal patients of different age groups were carried out. Giardia cysts were observed in the faecal sample of both the diarrhoeal patients. Organisms were cultivated on non-specific as well as specific enrichment media. Based on morphological, physiological and biochemical characteristics, organisms were identified to genus level. Irrespective of the age, a sharp decrease in the population of Lactobacilli, Proteus, Aeromonas, Yersinia, Micrococci and Escherichia coli with concomitant increase in the population of Klebsiella were observed in the diseased individuals when compared with the healthy ones. Significant differences were observed in the population of spore-forming Bacillus and Staphylococcus when both the diseased individuals were compared. Absence of Enterococcus and Providencia both in the child and adult diseased individuals were quite significant. Association of Candida, Pseudomonas and other aerobic spore formers only with the adult individuals confirmed some of the earlier observations. The presence of Gram-positive Diplococci and unidentified Gram-negative cocci in the healthy child were quite significant. It was therefore, evident that the alteration of resident flora was associated with the disease.  相似文献   

10.
The presence of Malassezia spp. yeasts was investigated in dermatological specimens of 224 dogs, 164 dermatologically diseased and 60 normal dogs. Subjects included in the study were of different breed, age, sex and habitat. Malassezia spp. positive cultures were obtained in 142 (63.4%) specimens: 67.6% from dermatologically diseased subjects and 51.6% from healthy dogs. Malassezia pachydermatis, either as a pure culture or in association with lipid-dependent species, was identified in 138 (97%) specimens. Malassezia furfur was identified in 69 (48.6%) specimens and was associated with other Malassezia species in 68 dogs, as a pure culture in one subject: at the best of our knowledge, this species was identified before as the sole species from canine dermatitis. Malassezia sympodialis was identified in 11 (7.7%) specimens, always in association with other species: it was never isolated from kennel dogs. Statistical analysis of data showed a very significant difference (P < 0.01) in the prevalence of isolation of Malassezia spp. between animals with and without dermatological signs, and in the distribution of cultural burden between diseased and healthy dogs. A statistically significant difference (P<0.05) was also detected in the group of animals between 1- and 5-years of age. No significant difference was found between male and female dogs.  相似文献   

11.
Factor analysis was applied to EEG recordings of healthy and diseased subjects to be analyzed by an "on line" broad-band frequency analyser. Differences between the healthy and the diseased as to the number of given factors were established by means of the Lawly test. Up to 6 factors were determined for patients, up to 3 for the healthy. On medication, the number of factors rose in the delta and beta bands, remaining unchanged in the alpha band dropping the theta band. The patients manifested a sort of interindividual uniformity and intraindividual simplification. Except for different sites of pathological foci, the patients' EEG recordings were more like each other than those of healthy subjects. The latter might have undergone a similar process on medication. This enabled to establish more factors in the patients, moreover in such a way as to expose some general laws of cortical electric activity, such as unified cortical activity despite its various facets, hemispheral specificity, and finally also a relative autonomy of the frontal lobes.  相似文献   

12.
The heart is capable of utilizing a variety of substrates to produce the necessary ATP for cardiac function. AMP-activated protein kinase (AMPK) has emerged as a key regulator of cellular energy homeostasis and coordinates multiple catabolic and anabolic pathways in the heart. During times of acute metabolic stresses, cardiac AMPK activation seems to be primarily involved in increasing energy-generating pathways to maintain or restore intracellular ATP levels. In acute situations such as mild ischemia or short durations of severe ischemia, activation of cardiac AMPK appears to be necessary for cardiac myocyte function and survival by stimulating ATP generation via increased glycolysis and accelerated fatty acid oxidation. Whereas AMPK activation may be essential for adaptation of cardiac energy metabolism to acute and/or minor metabolic stresses, it is unknown whether AMPK activation becomes maladaptive in certain chronic disease states and/or extreme energetic stresses. However, alterations in cardiac AMPK activity are associated with a number of cardiovascular-related diseases such as pathological cardiac hypertrophy, myocardial ischemia, glycogen storage cardiomyopathy, and Wolff-Parkinson-White syndrome, suggesting the possibility of a maladaptive role. Although the precise role AMPK plays in the diseased heart is still in question, it is clear that AMPK is a major regulator of cardiac energy metabolism. The consequences of alterations in AMPK activity and subsequent cardiac energy metabolism in the healthy and the diseased heart will be discussed.  相似文献   

13.
Aldehyde dehydrogenase (ALDH, EC 1.2.1.3) of the human prostate was the subject of investigation in this study. The possible physiological role of aldehyde dehydrogenase in the human prostate might be to detoxify aldehydes arising from the oxidation of the polyamines via monoamine or diamine oxidases. The specific activity of the enzyme with 1 mM propionaldehyde as substrate and 0.5 mM NAD at pH 7.4 in the control normal prostates and prostates afflicted with the disease, benign prostatic hyperplasia (BPH), was 26.06 +/- 2.96 and 5.17 +/- 0.48 nmol/g prostate per min, respectively. When 100 microM gamma-aminobutyraldehyde was used as a substrate, the specific activity in the normal controls and prostates with benign prostatic hyperplasia was 19.80 +/- 1.33 and 2.95 +/- 2.46 nmol/g prostate per min, respectively. Upon isoelectric focusing of the extracts of the control prostates when the gels were developed for aldehyde dehydrogenase activity, there were three aldehyde dehydrogenase activity bands visible, pI 4.9 (mitochondrial), 5.4 (cytosolic) and about 6.0-6.5, on the IEF gels developed with gamma-aminobutyraldehyde as a substrate. With the extracts of prostates with benign prostatic hyperplasia the pI 4.9 band was significantly reduced, the pI 5.4 band enhanced and the approx. pI 6.0 band was not detectable on the IEF gels with propionaldehyde as a substrate. There was no detectable aldehyde dehydrogenase activity in the extract of the prostate with cancer on IEF gels nor in the activity assays with propionaldehyde or gamma-aminobutyraldehyde as substrates.  相似文献   

14.
This paper presents a new concentrated parameter model for cardiovascular dynamics that includes an innovative model of heart valve dynamics, which is embedded in the overall model of the four chambers of the heart and the systemic and pulmonary circulation loops. The heart chambers are described with a variable elastance model, and the systemic and pulmonary loops are described with modified Windkessel models. In modelling the heart valve dynamics, the various factors that influence the valve motion are examined, and the governing differential equation for valve motion is derived. The heart valve model includes the influence of the blood pressure effect, the friction effect from the tissue, and from blood motion. As improvement from previous works, the contribution of the blood vortex effect in the vicinity of the valve leaflets to valve motion is specially considered. The proposed model is then used in simulation of healthy and certain pathological conditions such as mitral valve stenosis and aortic regurgitation. The predicted results agree well with results illustrated in cardiology textbooks.  相似文献   

15.
The vitamin D(3) and nicotine (VDN) model is a model of isolated systolic hypertension (ISH) due to arterial calcification raising arterial stiffness and vascular impedance similar to an aged and stiffened arterial tree. We therefore analyzed the impact of this aging model on normal and diseased hearts with myocardial infarction (MI). Wistar rats were treated with VDN (n = 9), subjected to MI by coronary ligation (n = 10), or subjected to a combination of both MI and VDN treatment (VDN/MI, n = 14). A sham-treated group served as control (Ctrl, n = 10). Transthoracic echocardiography was performed every 2 wk, whereas invasive indexes were obtained at week 8 before death. Calcium, collagen, and protein contents were measured in the heart and the aorta. Systolic blood pressure, pulse pressure, thoracic aortic calcium, and end-systolic elastance as an index of myocardial contractility were highest in the aging model group compared with MI and Ctrl groups (P(VDN) < 0.05, 2-way ANOVA). Left ventricular wall stress and brain natriuretic peptide (P(VDNxMI) = not significant) were highest, while ejection fraction, stroke volume, and cardiac output were lowest in the combined group versus all other groups (P(VDNxMI) < 0.05). The combination of ISH due to this aging model and MI demonstrates significant alterations in cardiac function. This model mimics several clinical phenomena of cardiovascular aging and may thus serve to further study novel therapies.  相似文献   

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Cardiac arrhythmia is a serious clinical condition, which is frequently associated with abnormalities of mechanical loading and changes in wall tension of the heart. Recent novel findings suggest that fibroblasts may function as mechano-electric transducers in healthy and diseased hearts. Cardiac fibroblasts are electrically non-excitable cells that respond to spontaneous contractions of the myocardium with rhythmical changes of their resting membrane potential. This phenomenon is referred to as mechanically induced potential (MIP) and has been implicated in the mechano-electric feedback mechanism of the heart. Mechano-electric feedback is thought to adjust the frequency of spontaneous myocardial contractions to changes in wall tension, which may result from variable filling pressure. Electrophysiological recordings of single atrial fibroblasts indicate that mechanical compression of the cells may activate a non-selective cation conductance leading to depolarisation of the membrane potential. Reduced amplitudes of MIPs due to pharmacological disruption of F-actin and tubulin suggest a role for the cytoskeleton in the mechano-electric signal transduction process. Enhanced sensitivity of the membrane potential of the fibroblasts to mechanical stretch after myocardial infarction correlates with depression of heart rates. It is assumed that altered electrical function of cardiac fibroblasts may contribute to the increased risk of post-infarct arrhythmia.  相似文献   

18.

Background  

Toll-like receptors (TLRs) play an essential role in the innate immune system by initiating and directing immune response to pathogens. TLRs are expressed in the human endometrium and their regulation might be crucial for the pathogenesis of endometrial diseases.  相似文献   

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Infectious diseases such as white plague syndrome (WPS) and black band disease (BBD) have caused massive coral loss worldwide. We performed a metaproteomic study on the Abrolhos coral Mussismilia braziliensis to define the types of proteins expressed in healthy corals compared to WPS‐ and BBD‐affected corals. A total of 6363 MS/MS spectra were identified as 361 different proteins. Healthy corals had a set of proteins that may be considered markers of holobiont homoeostasis, including tubulin, histone, Rab family, ribosomal, peridinin–chlorophyll a‐binding protein, F0F1‐type ATP synthase, alpha‐iG protein, calmodulin and ADP‐ribosylation factor. Cnidaria proteins found in healthy M. braziliensis were associated with CnidariaSymbiodinium endosymbiosis and included chaperones (hsp70, hsp90 and calreticulin), structural and membrane modelling proteins (actin) and proteins with functions related to intracellular vesicular traffic (Rab7 and ADP‐ribosylation factor 1) and signal transduction (14‐3‐3 protein and calmodulin). WPS resulted in a clear shift in the predominance of proteins, from those related to aerobic nitrogen‐fixing bacteria (i.e. Rhizobiales, Sphingomonadales and Actinomycetales) in healthy corals to those produced by facultative/anaerobic sulphate‐reducing bacteria (i.e. Enterobacteriales, Alteromonadales, Clostridiales and Bacteroidetes) in WPS corals. BBD corals developed a diverse community dominated by cyanobacteria and sulphur cycle bacteria. Hsp60, hsp90 and adenosylhomocysteinase proteins were produced mainly by cyanobacteria in BBD corals, which is consistent with elevated oxidative stress in hydrogen sulphide‐ and cyanotoxin‐rich environments. This study demonstrates the usefulness of metaproteomics for gaining better comprehension of coral metabolic status in health and disease, especially in reef systems such as the Abrolhos that are suffering from the increase in global and local threatening events.  相似文献   

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