MedWorm provides a medical RSS filtering service. Over 6000 RSS medical sources are combined and output via different filters. This feed contains the latest medical blog items that have been tagged with 'homeostasis'. Sat, 03 Sep 2011 02:31:53 +0100 http://www.medworm.com/index.php?rid=4040651&cid=t_308327_113_f&fid=39278&url=http%3A%2F%2Fblogsite.mdbuyline.com%2F%3Fp%3D54 Can it be? Controlling internal bleeding without surgery or stitches?  Didn’t I see that on Star Trek?  Yes, but autonomous acoustic hemostasis is already here.  It’s an exciting technology based on high-intensity focused ultrasound (HIFU) used to induce targeted blood coagulation within the body. Uncontrolled bleeding is a life-threatening concern with trauma, surgery, and stroke patients. When I asked Dr. Timothy Fabian, MD, Wilson alumni professor of surgery and chairman of the department of surgery, University of Tennessee Health Science Center, about the numbers, he confirmed, “Traumatic injuries kill more than 170,000 people each year.” Blood loss is one of the first priorities in treating trauma and hemorrhagic stroke.  In fact, according to the National Trauma Institute... MD Buyline blogs http://www.medworm.com/rss/comments.php?id=4040651 Thu, 07 Oct 2010 13:49:34 +0100 4040651 http://www.medworm.com/index.php?rid=3416085&cid=t_308327_109_f&fid=34750&url=http%3A%2F%2Fpsychcentral.com%2Fblog%2Farchives%2F2010%2F03%2F29%2Fam-i-normal%2F This is a common theme I hear echoed from a lot of people I meet. “Am I normal?” “I can’t wait to feel more normal again.” “Must be nice being so normal…” The problem is, I don’t know what normal is. I suppose for some of the people, they mean “without the symptoms of my disorder.” That makes sense, especially as some symptoms of some disorders can be pretty severe and debilitating toward living their everyday life. But then I realize that even people without a diagnosed condition still don’t often feel “normal.” We live our lives, we have our stresses, we hate our bosses or the 9-to-5 routine, we get into arguments with our significant others. Is this “normal?” Some days you don’t know... World of Psychology blogs http://www.medworm.com/rss/comments.php?id=3416085 Mon, 29 Mar 2010 11:52:02 +0100 3416085 http://www.medworm.com/index.php?rid=3220091&cid=t_308327_77_f&fid=37259&url=http%3A%2F%2Fwww.horizonpress.com%2Fblogger%2F2010%2F01%2Firon-in-yeasts.html Yeasts take up iron by three main mechanisms. In the reductive uptake mechanism, specialized flavo-hemoproteins (Fre) dissociate extracellular ferric complexes by reduction involving trans-plasma membrane electron transfer. The resulting free iron is then imported by a high-affinity permease system (Ftr), coupled to a copper-dependent oxidase (Fet), which channels iron through the plasma membrane. As a consequence, iron uptake by this mechanism is dependent on the availability of copper. In the siderophore-mediated mechanism, siderophores excreted by the cells or produced by other bacterial or fungal species are taken up without prior dissociation, via specific, copper-independent high-affinity receptors. The iron is then dissociated from the siderophores intracellularly, probably by reduc... Microbiology Blog: The weblog for microbiologists. blogs http://www.medworm.com/rss/comments.php?id=3220091 Thu, 28 Jan 2010 13:52:00 +0100 3220091 http://www.medworm.com/index.php?rid=3220092&cid=t_308327_77_f&fid=37259&url=http%3A%2F%2Fwww.horizonpress.com%2Fblogger%2F2010%2F01%2Firon-in-staphylococci.html Staphylococcus aureus causes a significant amount of human morbidity and mortality. The ability of S. aureus to cause disease is dependent upon its acquisition of iron from the host. S. aureus can obtain iron from various sources during infection, including heme and transferrin. The most abundant iron source in humans is heme-iron bound by hemoglobin contained within erythrocytes. S. aureus is known to lyse erythrocytes through secretion of pore-forming toxins, providing access to host hemoglobin. Proteins of the iron-regulated surface determinant (Isd) system bind host hemoproteins, remove the heme cofactor, and shuttle heme into the cytoplasm for use as a nutrient iron source. Deletion of Isd system components decreases staphylococcal virulence, underscoring the importance of heme-iron a... Microbiology Blog: The weblog for microbiologists. blogs http://www.medworm.com/rss/comments.php?id=3220092 Thu, 28 Jan 2010 13:51:00 +0100 3220092 http://www.medworm.com/index.php?rid=3220093&cid=t_308327_77_f&fid=37259&url=http%3A%2F%2Fwww.horizonpress.com%2Fblogger%2F2010%2F01%2Firon-in-bacillus.html Bacillus subtilis is a metabolically versatile soil microbe and Gram-positive model organism that displays a sophisticated adaptive response to conditions of iron limitation. The endogenous siderophore of B. subtilis is bacillibactin, a trimeric catecholate siderophore similar in structure to enterobactin. In addition to bacillibactin, B. subtilis can obtain iron from several xenosiderophores, ferric citrate, heme, and through a newly discovered elemental iron permease. The regulation of iron homeostasis in B. subtilis is complex and involves a ferric uptake regulator (Fur) protein as master regulator and at least two subsidiary regulatory systems. The most significant of these is an iron-sparing/prioritization response controlled by the small RNA FsrA and three auxiliary proteins (FbpABC)... Microbiology Blog: The weblog for microbiologists. blogs http://www.medworm.com/rss/comments.php?id=3220093 Thu, 28 Jan 2010 13:50:00 +0100 3220093 http://www.medworm.com/index.php?rid=3220095&cid=t_308327_77_f&fid=37259&url=http%3A%2F%2Fwww.horizonpress.com%2Fblogger%2F2010%2F01%2Firon-in-campylobacter.html Iron is known to catalyze a wide range of biochemical reactions essential for most living organisms, including Campylobacter jejuni. Paradoxically, this iron reactivity is also responsible for the generation of hydroxyl radicals (·OH), which are particularly biotoxic. In order to avoid iron toxicity, microorganisms must achieve an effective iron homeostasis by tightly regulating the expression of genes encoding the proteins involved in iron acquisition, metabolism and oxidative stress defences in response to iron availability. Interestingly, in addition to the classical ferric uptake regulator Fur, C. jejuni carries another member of the Fur family of metalloregulators, PerR. PerR is a peroxide-sensing regulator and typically regulates peroxide stress response in Gram-positive bacteri... Microbiology Blog: The weblog for microbiologists. blogs http://www.medworm.com/rss/comments.php?id=3220095 Thu, 28 Jan 2010 13:49:00 +0100 3220095 http://www.medworm.com/index.php?rid=3220094&cid=t_308327_77_f&fid=37259&url=http%3A%2F%2Fwww.horizonpress.com%2Fblogger%2F2010%2F01%2Firon-in-cyanobacteria.html Cyanobacteria are dependent on but can also be compromised by metals such as iron. On the one hand the demand for iron for photosystem functionality represents a challenge for the iron uptake machinery in iron limiting environments. On the other hand intoxication by iron causes a severe problem for growth and reproduction. To overcome this dilemma cyanobacteria have developed a regulatory network controlling iron uptake. They produce siderophores, which are distinct from that of other bacteria. Furthermore, the iron metabolism is linked to the nitrogen metabolism as documented for example in Anabaena sp. PCC 7120.Further reading: Iron Uptake and Homeostasis in MicroorganismsFull range of books on microbiology at Microbiology Books (Source: Microbiology Blog: The weblog for microbiologists.... Microbiology Blog: The weblog for microbiologists. blogs http://www.medworm.com/rss/comments.php?id=3220094 Thu, 28 Jan 2010 13:49:00 +0100 3220094 http://www.medworm.com/index.php?rid=3220096&cid=t_308327_77_f&fid=37259&url=http%3A%2F%2Fwww.horizonpress.com%2Fblogger%2F2010%2F01%2Firon-in-bacteroides.html Bacteroides spp. have an essential requirement for heme and non-heme iron. They cannot synthesize the tetrapyrrole macrocycle ring due to a lack of genes for the heme biosynthetic pathway. It is remarkable that heme-dependent organisms outnumber heme-independent organisms in the lower intestinal tract suggesting that heme biosynthesis is not essential for colonization of the colonic environment. However, this colonization advantage may be due to the fact that under anaerobic conditions in the presence of heme, B. fragilis can generate nearly the double amount of ATP than Escherichia coli per mol of glucose. This high energy yield is linked to a rudimentary heme-induced fumarate reductase and cytochrome b-dependent electron transport energy metabolism pathway which uses fumarate as the term... Microbiology Blog: The weblog for microbiologists. blogs http://www.medworm.com/rss/comments.php?id=3220096 Thu, 28 Jan 2010 13:48:00 +0100 3220096 http://www.medworm.com/index.php?rid=3220097&cid=t_308327_77_f&fid=37259&url=http%3A%2F%2Fwww.horizonpress.com%2Fblogger%2F2010%2F01%2Firon-in-francisella.html Francisella tularensis is unusual among Gram-negative bacteria in that its genome does not encode orthologs for TonB, ExbB and ExbD that typically energize the uptake of iron across the outer membrane. This organism secretes however a siderophore similar in structure to rhizoferrin. The fsl operon of six genes encodes functions for biosynthesis and uptake of the siderophore. Two of these genes encode a siderophore synthetase belonging to the nonribosomal peptide synthetase (NRPS)-independent synthetase (NIS)-family and a protein belonging to the pyridoxyl phosphate-dependent decarboxylase family, and both are required for siderophore production. Siderophore utilization involves the product of the fslE gene, a protein unique to Francisella species that could function as a siderophore recept... Microbiology Blog: The weblog for microbiologists. blogs http://www.medworm.com/rss/comments.php?id=3220097 Thu, 28 Jan 2010 13:47:00 +0100 3220097 http://www.medworm.com/index.php?rid=3220099&cid=t_308327_77_f&fid=37259&url=http%3A%2F%2Fwww.horizonpress.com%2Fblogger%2F2010%2F01%2Firon-in-erwinia.html The critical role of iron in host-pathogen relationships has been elucidated in infectious diseases of mammals, where the importance of siderophores in microbial pathogenesis has been demonstrated. Our group has established the role of iron and its ligands in the virulence of the plant pathogenic bacteria Dickeya dadantii (Erwinia chrysanthemi) and Erwinia amylovora. The genomes of the two pectinolytic enterobacterial species Pectobacterium atrosepticum SCRI1043 and D. dadantii 3937 have been sequenced and annotated. This review focuses on the functions involved in iron acquisition in both species. Besides the production and utilization of siderophores, P. atrosepticum and D. datantii have the capacity to use other iron sources. Indeed, both species are able to use haem iron, whereas only ... Microbiology Blog: The weblog for microbiologists. blogs http://www.medworm.com/rss/comments.php?id=3220099 Thu, 28 Jan 2010 13:45:00 +0100 3220099 http://www.medworm.com/index.php?rid=3220100&cid=t_308327_77_f&fid=37259&url=http%3A%2F%2Fwww.horizonpress.com%2Fblogger%2F2010%2F01%2Firon-shigella-and-e-coli.html Shigella spp. and pathogenic E. coli are characterized by a variety and abundance of iron transport systems. Although members of this group of bacteria are closely related genetically, they differ widely in the iron transport systems they use. This may reflect the different niches occupied by different strains and the nature of the source of iron available in a specific environment. Only the ferrous iron transporter Feo is common to all the commensals and pathogens. All members of this group produce one or more siderophore, but no single siderophore is produced by all. Other iron transport systems include heme transporters and the ferrous iron transporters Sit and Efe. With the exception of the genes for enterobactin and the Feo system, the iron transport genes in the enterics are found wi... Microbiology Blog: The weblog for microbiologists. blogs http://www.medworm.com/rss/comments.php?id=3220100 Thu, 28 Jan 2010 13:43:00 +0100 3220100 http://www.medworm.com/index.php?rid=3220102&cid=t_308327_77_f&fid=37259&url=http%3A%2F%2Fwww.horizonpress.com%2Fblogger%2F2010%2F01%2Firon-in-rhizobia.html The rhizobia live as free-living soil bacteria or in symbiosis with leguminous plants. The success of these organisms in each milieu involves the ability to sense the environment to assess the availability of nutrients, and to optimize cellular systems for their acquisition. Iron in the rhizosphere is mostly inaccessible due to low solubility, and microorganisms must compete for this limited nutrient. Rhizobia belong to the alpha-Proteobacteria, a diverse taxonomic group that includes numerous species that form close or intracellular associations with eukaryotic hosts in a symbiotic or pathogenic context. Thus, in addition to their agricultural and economic importance, rhizobia are model organisms that have given new insights into related, but less tractable animal pathogens. In particular... Microbiology Blog: The weblog for microbiologists. blogs http://www.medworm.com/rss/comments.php?id=3220102 Thu, 28 Jan 2010 13:41:00 +0100 3220102 http://www.medworm.com/index.php?rid=3220104&cid=t_308327_77_f&fid=37259&url=http%3A%2F%2Fwww.horizonpress.com%2Fblogger%2F2010%2F01%2Firon-uptake-and-homeostasis-in.html Iron is essential for almost all living organisms as it is involved in a wide variety of important metabolic processes. However, iron is not readily available and microorganisms therefore employ various iron uptake systems to secure sufficient supplies from their surroundings. There is considerable variation in the range of iron transporters and iron sources utilised by different microbial species. Pathogens, in particular, require efficient iron acquisition mechanisms to enable them to compete successfully for iron in the highly iron-restricted environment of the host's tissues and body fluids.Further reading: Iron Uptake and Homeostasis in MicroorganismsFull range of books on microbiology at Microbiology Books (Source: Microbiology Blog: The weblog for microbiologists.) Microbiology Blog: The weblog for microbiologists. blogs http://www.medworm.com/rss/comments.php?id=3220104 Thu, 28 Jan 2010 13:39:00 +0100 3220104 http://www.medworm.com/index.php?rid=832653&cid=t_308327_134_f&fid=36049&url=http%3A%2F%2Ffeeds.b5media.com%2F%7Er%2Fb5media%2FDiabetesNotes%2F%7E3%2F150317128%2F Scientists have revisited the fact that certain neurons in the brain are activated by glucose. And this time they have identified that defects in the brain’s ability to respond to glucose can play a role in the development of type 2 diabetes. How is this research of clinical use you ask… “By identifying glucose-sensing neurons in the brain as important players in regulating glucose, our findings may open a new avenue of research,” Dr. Coppari said. “Because these neurons play a role in maintaining glucose homeostasis throughout the body, an impairment in their glucose-sensing ability could play a pathogenic role in type 2 diabetes, where homeostasis is altered.” In a nut shell, curb the glucose-sensing neurons into reacting appropriately and there is a d... Diabetes Notes blogs http://www.medworm.com/rss/comments.php?id=832653 Fri, 31 Aug 2007 00:42:21 +0100 832653 http://www.medworm.com/index.php?rid=612016&cid=t_308327_87_f&fid=34867&url=http%3A%2F%2Fwww.thediabetesblog.com%2F2007%2F05%2F15%2Ftrying-to-turn-off-the-diabetes-switch%2F Filed under: Type 2, Adult Onset, ResearchScientists are looking to a specific gene called TXNIP as a possible means of preventing the onset of type 2 and prediabetes. What's known at this point is that in patients who express high levels TXNIP (which is oftentimes the case with those that have type 2 or prediabetes), these elevated levels can inhibit glucose uptake in fat and muscle cells. More or less, the researchers believe that TXNIP acts as a glucose/insulin sensitive switch, and this function becomes compromised early in the development of diabetes. But, there is still a great deal more investigation into the role of TXNIP to be done before scientists know its exact rule in glucose homeostasis. Nevertheless, the research thus far points to some connection between TXNIP and the ons... The Diabetes Blog blogs http://www.medworm.com/rss/comments.php?id=612016 Tue, 15 May 2007 04:00:00 +0100 612016