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Giornale Italiano Di Nefrologia :... 2010Central venous catheters (CVCs) are fundamental in the management of hemodialysis. Despite major efforts to provide arteriovenous access, their use is increasing in...
Central venous catheters (CVCs) are fundamental in the management of hemodialysis. Despite major efforts to provide arteriovenous access, their use is increasing in dialysis units worldwide. The presence of a catheter inside a vein increases the risk of thrombosis, both within the catheter and in the vein. Thrombosis is a serious complication because it can lead to inefficient dialysis, alter the venous circulation, and facilitate infections. In this article, questions regarding anticoagulant treatment in dialysis patients with CVCs are explored and specific suggestions offered for clinical practice, based on the evidence available and the personal experience of the authors. Should CVC-induced thrombosis be treated? The duration, site and extension of the thrombotic complication should be assessed. If thrombosis is recent and symptomatic, heparin treatment followed by oral anticoagulant therapy is suggested. Is oral anticoagulant therapy useful for primary prevention of thrombosis, both within the CVC and the vein where the catheter is inserted? The available evidence favoring the use of oral anticoagulant therapy is not entirely convincing. At any rate, before such treatment is started the balance between the antithrombotic efficacy and the possible side effects should be carefully weighed. Is oral anticoagulant therapy useful for secondary prevention of CVC thrombosis? If a permanent CVC is in place and its position is correct and the blood flow < 250 mL/min, we recommend - before replacing the CVC - thrombolytic treatment followed by oral anticoagulants, aiming at an INR target between 2 and 3. Are the side effects of oral anticoagulant therapy an issue? The use of anticoagulants in renal failure carries an increased risk of complications, in particular bleeding and vascular calcifications, which could annul the advantages derived from reduced thrombotic events. Before starting oral anticoagulant therapy we suggest to carefully evaluate if there are potential overall benefits and to pay attention to concomitant antiplatelet therapy.
Topics: Administration, Oral; Anticoagulants; Catheterization, Central Venous; Humans; Renal Dialysis; Thrombosis
PubMed: 20922680
DOI: No ID Found -
The Journal of Biological Chemistry Mar 1990Phosphatidylserine decarboxylase from Escherichia coli uses a pyruvate group as the enzyme cofactor (Satre, M., and Kennedy, E. P. (1978) J. Biol. Chem. 253, 479-483)....
Phosphatidylserine decarboxylase from Escherichia coli uses a pyruvate group as the enzyme cofactor (Satre, M., and Kennedy, E. P. (1978) J. Biol. Chem. 253, 479-483). Comparison of the DNA sequence of the psd gene with the partial amino acid sequence of the mature gene product suggests that the two nonidentical subunits of the mature enzyme are formed by cleavage of a proenzyme resulting in the conversion of Ser-254 to an amino-terminal pyruvate residue (Li, Q.-X., and Dowhan, W. (1988) J. Biol. Chem. 263, 11516-11522). The cleavage of the wild-type proenzyme occurs rapidly with a half-time on the order of 2 min. When Ser-254 is changed to cysteine (S254C), threonine (S254T), or alanine (S254A) by site-directed mutagenesis, the rate of processing of the proenzyme and the production of the functional enzyme are drastically affected. Proenzymes with S254C or S254T are cleaved with a half-time of around 2-4 h while the S254A proenzyme does not undergo processing. The reduced processing rate for the mutant proenzymes is consistent with less of the functional enzyme being made. Mutants encoding the S254C and S254T protein produce 16 and 2%, respectively, of the activity of the wild-type allele but can still complement a temperature-sensitive mutant in the psd locus. There is no detectable activity or complementation observed with the S254A protein. These results are consistent with the hydroxyl group of Ser-254 playing a critical role in the cleavage of the peptide bond between Gly-253 and Ser-254 of the prophosphatidylserine decarboxylase and support the mechanism proposed by Snell and coworkers (Recsei and Snell (1984) Annul Rev. Biochem. 53, 357-387) for the formation of the prosthetic group of pyruvate-dependent decarboxylases.
Topics: Carboxy-Lyases; Escherichia coli; Molecular Weight; Mutation; Plasmids; Pyruvates; Restriction Mapping
PubMed: 2406271
DOI: No ID Found -
Clinical and Experimental Immunology Jul 1975(1) There is evidence that the symptoms of multiple sclerosis (MS) are at least partly the consequence of an auto-aggressive immunological reaction. For this reason, we...
(1) There is evidence that the symptoms of multiple sclerosis (MS) are at least partly the consequence of an auto-aggressive immunological reaction. For this reason, we undertook a small (fourteen patients) trial of the remedial effects of intensive immunosuppression: the combined administration of corticosteroid, Imuran (azathioprine) and antilymphocyte globulin (ALG). (2) When the trial started the patients were 19–58 years old (eleven under 40) and their disease was of 1–33 years duration (ten had the disease for 3 years or less, and twelve had active disease at the outset). (3) Taking day 0 as the first day of treatment, prednisone (150 mg/day) was started on day 0 and tapered rapidly to 20 mg/day by day 7. In an attempt to annul the immunogenicity of ALG as a foreign protein all patients received intravenous infusions of aggregate-free normal horse IgG on days 1 and 4 at dosages of 60 mg/kg and 30 mg/kg respectively. Imuran (3 mg/kg) was started on day 0 and continued at this level throughout the study. (4) Intravenous ALG/500 mg was given on day 7, and on the weekdays of the following 3 weeks. During this intensive immunosuppression the patients were maintained in semi-isolation using barrier nursing techniques. (5) Patients were kept in hospital for 1 week after the end of ALG treatment, and then discharged on a maintenance dose of prednisone (20 mg/day) and Imuran (3 mg/day). Patients were asked to attend Outpatients at 3-monthly intervals to evaluate their progress. At the end of a year immunosuppressive drugs were tapered in preparation for complete withdrawal. (6) Undesirable side effects, classified under the agents probably responsible for them, were as follows. ALG. Minor phlebitic episodes responding to warm soaks, and in one patient evidence of anaphylaxis relieved by hydrocortisone, antihistamine and reduction of ALG. A second patient developed signs of serum sickness which disappeared when ALG was stopped and the steroid dosage temporarily increased. . Some hair loss, but no patient became anaemic or leukopaenic, and liver function tests revealed no abnormality. . This was responsible for the most distressing side effects; mild to moderate moon facies and weight gain in eleven out of fourteen patients. Six patients were dyspeptic, and one developed duodenal ulceration with occult bleeding. One patient with a long history of ACTH treatment developed osteoporosis and a spontaneous compression fracture. Infection was not a cause of anxiety. (7) The clinical appraisal was based on a 4-point scalar evaluation of sensory and motor modalities, balance, speech and vision. The final ratings were agreed by three assessors. (8) Most patients reported improvement during the first 2–3 weeks' treatment, especially during the first few days of ALG therapy, though the degree and nature of the improvement varied greatly. In a few patients symptoms of many years' standing improved. (9) As most patients had MS of the intermittently active type, special attention was paid to relapse rates before, during and after treatment. Relapses were signalized by the appearance of any new sign or symptom or progression for more than 10 days of a pre-existing complaint. (10) In two patients who relapsed at 6 and 9 months respectively, the relapses were less severe than those which had occurred before treatment and were easier to control. (11) Using patients as their own controls, there was found to be a significant reduction in relapse rate compared with the number predicted on the basis of their experience before treatment. (12) Some patients underwent relapses a few weeks or months after significant drug reductions; for this reason some patients required continued immunosuppressive treatment, though all drugs have been withdrawn from three patients. (13) Intensive immunosuppression, well tolerated by patients, is a feasible and clinically acceptable procedure, and its results, taken in conjunction with those of Brendel in Munich, justify further investigation of its use for the treatment of MS. (14) Detailed immunological findings are the subject of two succeeding papers.
Topics: Adrenal Cortex Hormones; Adult; Anaphylaxis; Animals; Antilymphocyte Serum; Azathioprine; Female; Follow-Up Studies; Horses; Humans; Immunoglobulin G; Immunosuppression Therapy; Infusions, Parenteral; Male; Middle Aged; Multiple Sclerosis; Phlebitis; Prednisone; Remission, Spontaneous; Serum Sickness; Water-Electrolyte Balance
PubMed: 1237376
DOI: No ID Found -
Annals of Surgery Aug 2006To estimate the prevalence of residual pain 2 to 3 years after hernia surgery, to identify factors associated with its occurrence, and to assess the consequences for the...
OBJECTIVE
To estimate the prevalence of residual pain 2 to 3 years after hernia surgery, to identify factors associated with its occurrence, and to assess the consequences for the patient.
SUMMARY BACKGROUND DATA
Iatrogenic chronic pain is a neglected problem that may totally annul the benefits from hernia repair.
METHODS
From the population-based Swedish Hernia Register 3000 patients aged 15 to 85 years were sampled from the 9280 patients registered as having undergone a primary groin hernia operation in the year 2000. Of these, the 2853 patients still alive in 2003 were requested to fill in a postal questionnaire.
RESULTS
After 2 reminders, 2456 patients (86%), 2299 men and 157 women responded. In response to a question about "worst perceived pain last week," 758 patients (31%) reported pain to some extent. In 144 cases (6%), the pain interfered with daily activities. Age below median, a high level of pain before the operation, and occurrence of any postoperative complication were found to significantly and independently predict long-term pain in multivariate logistic analysis when "worst pain last week" was used as outcome variable. The same variables, along with a repair technique using anterior approach, were found to predict long-term pain with "pain right now" as outcome variable.
CONCLUSION
Pain that is at least partly disabling appears to occur more often than recurrences. The prevalence of long-term pain can be reduced by preventing postoperative complications. The impact of repair technique on the risk of long-term pain shown in our study should be further assessed in randomized controlled trials.
Topics: Adolescent; Adult; Age Factors; Aged; Aged, 80 and over; Female; Follow-Up Studies; Hematoma; Hernia, Femoral; Hernia, Inguinal; Humans; Iatrogenic Disease; Longitudinal Studies; Male; Middle Aged; Pain; Pain, Postoperative; Population Surveillance; Postoperative Complications; Prevalence; Risk Factors; Surgical Wound Infection; Sweden; Treatment Outcome
PubMed: 16858183
DOI: 10.1097/01.sla.0000218081.53940.01 -
Materials Science & Engineering. C,... May 2021The recently proposed concept of quaternary bioreceptivity applies to substrates treated with coating materials and it is considered in the present study with the alga...
The recently proposed concept of quaternary bioreceptivity applies to substrates treated with coating materials and it is considered in the present study with the alga Bracteacoccus minor and the cyanobacterium Nostoc sp. onto granite specimens treated with ethyl silicate and nano-sized silica doped with different amounts of TiO (0, 0.5, 1 and 3 wt%). The findings showed a lack of correlation between the amount of TiO and the level of colonization (main bioreceptivity estimator) to the presence of cracks on the surface, which annul the biocidal power of TiO. Crack formation, which depends on the mechanical properties, greatly influences the bioreceptivity of the material. Thus, the cracks provided anchor points where water is retained, in turn strongly influencing the early stages of colonization kinetics, to a greater extent than the biocidal power of TiO, which will probably increase as the biofilm develops over the entire surface. In addition, although the cracks were more abundant and wider in the ethyl silicate-based consolidant, the nano-sized silica provided better anchoring points, making the material treated with the corresponding consolidant more bioreceptive.
Topics: Biofilms; Construction Materials; Ecosystem; Humans; Titanium
PubMed: 33947552
DOI: 10.1016/j.msec.2021.112058 -
Plant Methods Nov 2008Analysis of survival is commonly used as a means of comparing the performance of plant lines under drought. However, the assessment of plant water status during such...
BACKGROUND
Analysis of survival is commonly used as a means of comparing the performance of plant lines under drought. However, the assessment of plant water status during such studies typically involves detachment to estimate water shock, imprecise methods of estimation or invasive measurements such as osmotic adjustment that influence or annul further evaluation of a specimen's response to drought.
RESULTS
This article presents a procedure for rapid, inexpensive and non-invasive assessment of the survival of soil-grown plants during drought treatment. The changes in major photosynthetic parameters during increasing water deficit were monitored via chlorophyll fluorescence imaging and the selection of the maximum efficiency of photosystem II (Fv/Fm) parameter as the most straightforward and practical means of monitoring survival is described. The veracity of this technique is validated through application to a variety of Arabidopsis thaliana ecotypes and mutant lines with altered tolerance to drought or reduced photosynthetic efficiencies.
CONCLUSION
The method presented here allows the acquisition of quantitative numerical estimates of Arabidopsis drought survival times that are amenable to statistical analysis. Furthermore, the required measurements can be obtained quickly and non-invasively using inexpensive equipment and with minimal expertise in chlorophyll fluorometry. This technique enables the rapid assessment and comparison of the relative viability of germplasm during drought, and may complement detailed physiological and water relations studies.
PubMed: 19014425
DOI: 10.1186/1746-4811-4-27 -
Proceedings of the National Academy of... Oct 2015The complement system has evolved to annul pathogens, but its improper regulation is linked with diseases. Efficient regulation of the system is primarily provided by a...
The complement system has evolved to annul pathogens, but its improper regulation is linked with diseases. Efficient regulation of the system is primarily provided by a family of proteins termed regulators of complement activation (RCA). The knowledge of precise structural determinants of RCA proteins critical for imparting the regulatory activities and the molecular events underlying the regulatory processes, nonetheless, is still limited. Here, we have dissected the structural requirements of RCA proteins that are crucial for one of their two regulatory activities, the cofactor activity (CFA), by using the Kaposi's sarcoma-associated herpesvirus RCA homolog Kaposica as a model protein. We have scanned the entire Kaposica molecule by sequential mutagenesis using swapping and site-directed mutagenesis, which identified residues critical for its interaction with C3b and factor I. Mapping of these residues onto the modeled structure of C3b-Kaposica-factor I complex supported the mutagenesis data. Furthermore, the model suggested that the C3b-interacting residues bridge the CUB (complement C1r-C1s, Uegf, Bmp1) and MG2 (macroglobulin-2) domains of C3b. Thus, it seems that stabilization of the CUB domain with respect to the core of the C3b molecule is central for its CFA. Identification of CFA-critical regions in Kaposica guided experiments in which the equivalent regions of membrane cofactor protein were swapped into decay-accelerating factor. This strategy allowed CFA to be introduced into decay-accelerating factor, suggesting that viral and human regulators use a common mechanism for CFA.
Topics: Complement C3b; Complement Factor I; Herpesvirus 8, Human; Humans; Models, Molecular; Multiprotein Complexes; Protein Structure, Quaternary; Protein Structure, Tertiary; Viral Proteins
PubMed: 26420870
DOI: 10.1073/pnas.1506449112 -
Scientific Reports Mar 2020Ecological degradation impedes sustainable development in Southwest China, and artificial afforestation has been a key strategy of the Government of China to effectively...
Ecological degradation impedes sustainable development in Southwest China, and artificial afforestation has been a key strategy of the Government of China to effectively curb it. However, the water consumed by large-scale afforestation has a huge impact on water supply in Southwest China, which also arise a new challenge causing severe drought here recently. In order to determine the impact of artificial afforestation on the region, this study conducts spatiotemporal, abrupt change, and correlation and regression analyses. Results show that although water resources fluctuate, they exhibit a general declining trend. Especially after 2000, water resources showed a significant downward trend. In terms of spatial tendency, there has been an obvious decrease in water resources in the Sichuan Basin, the mountainous region of eastern Chongqing, and the Yunnan-Guizhou Plateau. Due to extensive afforestation and vegetation cover growth, there has been an increase in most trends of forest-shrub ecosystems, resulting in substantially enhanced evapotranspiration effects. The uptake of water by afforestation in Southwest China could reach 40.42 billion m, which is equivalent to 10.69% of its annul available water supply (1980-2015). Generally, afforestation disrupts the water balance of the region. This study recommends substituting afforestation for natural restoration or, at the very least, selecting vegetation that requires less water for the restoration of the ecological environment of Southwest China, which provide scientific method for regional sustainable development.
PubMed: 32139773
DOI: 10.1038/s41598-020-61108-w -
Brazilian Journal of Medical and... Nov 2008Chronic neurodegenerative processes have been identified in the rat forebrain after prolonged survival following hyperthermia (HT) initiated a few hours after transient...
Chronic neurodegenerative processes have been identified in the rat forebrain after prolonged survival following hyperthermia (HT) initiated a few hours after transient global ischemia. Since transient global ischemia and ischemic penumbra share pathophysiological similarities, this study addressed the effects of HT induced after recirculation of focal brain ischemia on infarct size during long survival times. Adult male Wistar rats underwent intra-luminal occlusion of the left middle cerebral artery for 60 min followed by HT (39.0-39.5 degrees C) or normothermia. Control procedures included none and sham surgery with and without HT, and middle cerebral artery occlusion alone. Part I: 6-h HT induced at recirculation. Part II: 2-h HT induced at 2-, 6-, or 24-h recirculation. Part III: 2-h HT initiated at recirculation or 6-h HT initiated at 2-, 6- or 24-h recirculation. Survival periods were 7 days, 2 or 6 months. The effects of post-ischemic HT on cortex and striatum were evaluated histopathologically by measuring the area of remaining tissue in the infarcted hemisphere at -0.30 mm from bregma. Six-hour HT initiated from 6-h recirculation caused a significant decrease in the remaining cortical tissue between 7-day (N = 8) and 2-month (N = 8) survivals (98.46 +/- 1.14 to 73.62 +/- 8.99%, respectively). When induced from 24-h recirculation, 6-h HT caused a significant reduction of the remaining cortical tissue between 2- (N = 8) and 6-month (N = 9) survivals (94.97 +/- 5.02 vs 63.26 +/- 11.97%, respectively). These data indicate that post-ischemic HT triggers chronic neurodegenerative processes in ischemic penumbra, suggesting that similar fever-triggered effects may annul the benefit of early recirculation in stroke patients over the long-term.
Topics: Animals; Brain Ischemia; Cerebral Cortex; Chronic Disease; Fever; Male; Nerve Degeneration; Rats; Rats, Wistar; Time Factors
PubMed: 19099155
DOI: 10.1590/s0100-879x2008001100014 -
Cancer Informatics 2013Cancer risk management involves obliterating excess concentration of cancer causing trace elements by the natural immune system and hence intake of nutritious diet is of...
Cancer risk management involves obliterating excess concentration of cancer causing trace elements by the natural immune system and hence intake of nutritious diet is of paramount importance. Human diet should consist of essential macronutrients that have to be consumed in large quantities and trace elements are to be consumed in very little amount. As some of these trace elements are causative factors for various types of cancer and build up at the expense of macronutrients, cancer risk management of these trace elements should be based on their initial concentration in the blood of each individual and not on their tolerable upper intake level. We propose an information theory based Expert System (ES) for estimating the lowest limit of toxicity association between the trace elements and the macronutrients. Such an estimate would enable the physician to prescribe required medication containing the macronutrients to annul the toxicity of cancer risk trace elements. The lowest limit of toxicity association is achieved by minimizing the correlated information of the concentration correlation matrix using the concept of Mutual Information (MI) and an algorithm based on a Technique of Determinant Inequalities (TDI) developed by the authors. The novelty of our ES is that it provides the lowest limit of toxicity profile for all trace elements in the blood not restricted to a group of compounds having similar structure. We demonstrate the superiority our algorithm over Principal Component Analysis in mitigating trace element toxicity in blood samples.
PubMed: 23439401
DOI: 10.4137/CIN.S10770