Home About us Contact
|
Home About us Contact | ||
|
|
||
Long-term Detrimental Effects (long-term + detrimental_effects)
Selected AbstractsMolecular control of ethylene production by cyanide in Arabidopsis thalianaPHYSIOLOGIA PLANTARUM, Issue 2 2000Jennifer McMahon Smith Although cyanide has long been recognized as a co-product of ethylene synthesis, little attention has been given to its potential physiological and molecular roles. In the present work, the long-term effects of cyanide on growth and development were observed in Arabidopsis thaliana. Two days after a single 20-min application of cyanide, plants demonstrated visible signs of stress. Long-term detrimental effects on growth and photosynthetic capabilities were noted, including low chlorophyll accumulation and stunted growth. Because of the relationship between cyanide and ethylene production, we chose to evaluate the results of cyanide treatment on genes encoding proteins involved in ethylene synthesis. We have found that only the 1-aminocyclopropane-1-carboxylic acid (ACC) synthase gene, ACS6, is rapidly activated in response to cyanide treatment, while other ACS genes were unaffected. This same gene has previously been shown to be transcriptionally activated in response to touch and other environmental stimuli. Cyanide was capable of activating ACS6 transcription within 10 min of treatment, and the amount of transcript correlated positively with the cyanide dosage. Due to the toxic nature of cyanide, plant in vivo concentrations are generally maintained lower than 10 ,M, but can increase under certain stresses. In the present work, we observed that physiologically relevant concentrations as low as 1 ,M HCN, considered metabolically ,safe', were capable of initiating ACS6 transcription. ACS6 transcripts were not substantially reduced as a result of multiple cyanide treatments, which is in contrast with the effects of mechanical stimulation on transcription. Our results suggest a relationship between cyanide production during ethylene synthesis and the molecular control of ethylene synthesis. This work corresponds with earlier experiments that have demonstrated that ethylene and cyanide can elicit some similar physiological responses. It is possible that cyanide may play an active role in ethylene regulation under conditions where rapid cyanide accumulation occurs. Since cyanide can rapidly activate ethylene synthesis, it is possible that it is involved in the positive-feedback regulation of ethylene that occurs in some plant tissues. [source] Effect of anti-inflammatory and antioxidant drugs on the long-term repair of severely injured mouse skeletal muscleEXPERIMENTAL PHYSIOLOGY, Issue 4 2005A. Vignaud Non-steroidal anti-inflammatory drugs are frequently prescribed after skeletal muscle injury. It is not known whether this type of medication can interfere with muscle repair, although inflammatory response is thought to play an important role in this process. Tibialis anterior muscles of mice were injured by myotoxic agent (snake venom) or crushed. Then, animals were treated daily for 10,14 days with different types of non-steroidal anti-inflammatory and antioxidant drugs. The long-term repair was studied 10,42 days after injury by analysing the recovery of in situ muscle force production, size of regenerating muscle cells and expression of myosin heavy chain. Our results show that diclofenac, diferuloylmethane (curcumin), dimethylthiourea or pyrrolidine dithiocarbamate treatment did not significantly affect muscle recovery after myotoxic injury (P > 0.05). Similarly, diferuloylmethane, dimethyl sulphoxide or indomethacin administration did not markedly change muscle repair after crush injury. However, we noted that high doses (> 2 mg kg,1) of diferuloylmethane or indomethacin increased lethality and reduced muscle repair after crush injury. In conclusion, non-steroidal anti-inflammatory and antioxidant drugs did not exhibit long-term detrimental effects on muscle recovery after injury, except at lethal doses. [source] Caloric Restriction and Calcium's Effect on Bone Metabolism and Body Composition in Overweight and Obese Premenopausal WomenNUTRITION REVIEWS, Issue 12 2004Tim L. Radak DrPH Obesity results in numerous preventable deaths and comorbidities. Unfortunately, a reduction of body weight has been correlated with a reduction in bone mass, the reasons for which have not been fully elucidated. The importance of maximizing peak bone mass during premenopausal years is well known. Most studies demonstrate a positive relationship between calcium intake and bone mass. However, during caloric restriction, which is commonly used for weight loss, calcium intake has shown mixed results. Calcium from dairy sources has received additional attention, beyond its importance to bone, for its role in regulating body weight and composition. Dairy foods are perceived as high fat, and therefore, are generally minimized or avoided during caloric restriction. The current calcium intake for premenopausal women is significantly below recommendations, and even if met during caloric restriction, may not be adequate. This review underscores the need for maintaining at least adequate intake levels of calcium, if not more, during weight loss regimens to minimize potential long-term detrimental effects on bone metabolism. [source] Airway function in infants treated with inhaled nitric oxide for persistent pulmonary hypertensionPEDIATRIC PULMONOLOGY, Issue 3 2008Aparna U. Hoskote MD Abstract Rationale Inhaled nitric oxide (iNO), used for treatment of persistent pulmonary hypertension of newborn (PPHN), is an oxygen free radical with potential for lung injury. Deferring ECMO with iNO in these neonates could potentially have long-term detrimental effects on lung function. We studied respiratory morbidity (defined as occurrence of respiratory infections requiring treatment, episodes of wheezing, and/or need for ongoing medications following discharge) and airway function at 1 year postnatal age in term neonates treated with iNO but not ECMO for PPHN, and compared data from similar infants recruited to the UK ECMO Trial randomized to receive ECMO or conventional management (CM). Methods Maximal expiratory flow at FRC (V'maxFRC) was measured in infants treated with iNO for PPHN (oxygenation index ,25) at birth. Results V'maxFRC was measured in 23 infants and expressed as z -scores, to adjust for sex and body size and compared to data from 71 (46 ECMO, 25 CM) infants studied at a similar age in the ECMO Trial. Respiratory morbidity was low in iNO group. V'maxFRCz -score was lower than predicted in all groups (P,<,0.001), with no significant difference between those treated with iNO [mean (SD) z -score: ,1.65 (1.2)] and those treated with ECMO [,1.59 (1.2)] or CM [,2.1(1.0)]. Within iNO, ECMO and CM groups; 26%, 37% and 56%, respectively, had V'maxFRCz -scores below normal. Conclusions Respiratory outcome at 1 year in iNO treated neonates with moderately severe PPHN is encouraging, with no apparent increase in respiratory morbidity when compared to the general population. Sub-clinical reductions in airway function are evident at 1 year, suggesting that continuing efforts to minimize lung injury in the neonatal period are warranted to maximize lung health in later life. Pediatr Pulmonol. 2008; 43:224,235. © 2008 Wiley-Liss, Inc. [source] Guidelines for procedural pain in the newbornACTA PAEDIATRICA, Issue 6 2009Paola Lago Abstract Despite accumulating evidence that procedural pain experienced by newborn infants may have acute and even long-term detrimental effects on their subsequent behaviour and neurological outcome, pain control and prevention remain controversial issues. Our aim was to develop guidelines based on evidence and clinical practice for preventing and controlling neonatal procedural pain in the light of the evidence-based recommendations contained in the SIGN classification. A panel of expert neonatologists used systematic review, data synthesis and open discussion to reach a consensus on the level of evidence supported by the literature or customs in clinical practice and to describe a global analgesic management, considering pharmacological, non-pharmacological, behavioural and environmental measures for each invasive procedure. There is strong evidence to support some analgesic measures, e.g. sucrose or breast milk for minor invasive procedures, and combinations of drugs for tracheal intubation. Many other pain control measures used during chest tube placement and removal, screening and treatment for ROP, or for postoperative pain, are still based not on evidence, but on good practice or expert opinions. Conclusion: These guidelines should help improving the health care professional's awareness of the need to adequately manage procedural pain in neonates, based on the strongest evidence currently available. [source] | |||||||||||||