Short Term vs Long Term Dexamethasone Treatment: Effects on Rat Diaphragm Structure and Function

Lung ◽  
1998 ◽  
Vol 176 (4) ◽  
pp. 267-280 ◽  
Author(s):  
D. J. Prezant ◽  
M. L. Karwa ◽  
B. Richner ◽  
D. Maggiore ◽  
E. I. Gentry ◽  
...  
Keyword(s):  
Treatment Effects ◽  
Structure And Function ◽  
Rat Diaphragm ◽  
Dexamethasone Treatment ◽  
Short Term ◽  
And Function

Gender-specific effects of dexamethasone treatment on rat diaphragm structure and function

1997 ◽  
Vol 82 (1) ◽  
pp. 125-133 ◽  
Author(s):  
D. J. Prezant ◽  
M. L. Karwa ◽  
B. Richner ◽  
D. Maggiore ◽  
E. I. Gentry ◽  
...  
Keyword(s):  
Structure And Function ◽  
Male Rats ◽  
Diaphragm Muscle ◽  
Rat Diaphragm ◽  
Dexamethasone Treatment ◽  
Testosterone Levels ◽  
Specific Effects ◽  
And Function ◽  
Gender Specific

Prezant, D. J., M. L. Karwa, B. Richner, D. Maggiore, E. I. Gentry, and J. Cahill. Gender-specific effects of dexamethasone treatment on rat diaphragm structure and function. J. Appl. Physiol. 82(1): 125–133, 1997.—The effects of long-term dexamethasone treatment on diaphragm muscle were studied in female and male rats. Compared with pair-fed control animals, dexamethasone treatment did not significantly affect estrous cycling or peak serum estradiol levels; however, testosterone levels were significantly increased in females and decreased in males. Dexamethasone significantly reduced body and costal diaphragm weights, but to a lesser extent in females than in males. Reductions in diaphragm weight were proportional to reductions in body weight. In females and males, dexamethasone treatment significantly decreased diaphragm fiber (types I and II) cross-sectional area and the relative expression of myosin heavy chain isoform 2B. With the exception of type I fiber atrophy, these changes occurred to a lesser extent in females. Dexamethasone did not significantly affect specific forces. Dexamethasone significantly increased twitch one-half relaxation time and fatigue resistance indexes in males but not in females. In conclusion, the effects of long-term dexamethasone treatment were gender specific, with significantly fewer effects in females, and changes in serum testosterone levels were associated with these findings.

scholarly journals The Effect of Perfluorooctane Sulfonate, Exposure Time, and Chemical Mixtures on Methanogenic Community Structure and Function

2015 ◽  
Vol 8s2 ◽  
pp. MBI.S31345 ◽  
Author(s):  
Patrick J. McNamara ◽  
Timothy M. LaPara ◽  
Paige J. Novak
Keyword(s):  
Community Structure ◽  
Exposure Time ◽  
Methane Production ◽  
Perfluorooctane Sulfonate ◽  
Structure And Function ◽  
Short Term ◽  
Anaerobic Digesters ◽  
And Function ◽  
The Impact

A plethora of organic micropollutant mixtures are found in untreated municipal wastewater. Anaerobic digesters receive large loadings of hydrophobic micropollutants that sorb to wastewater biosolids. Despite micropollutants being pervasive as mixtures, little research is available to explain the impact that mixtures of compounds, as well as exposure time, have on microbial communities in anaerobic digesters. Perfluorooctane sulfonate (PFOS) was added to anaerobic enrichment cultures in both short-term (14 days) and long-term (140 days) studies to determine the impact of exposure time. Additionally, triclosan was added during the experiments to investigate the impact of mixtures on community structure and function. PFOS did not alter methane production in short-term studies, but in long-term studies, methane production increased, consistent with our hypothesis that PFOS may act as a metabolic uncoupler. The impact of triclosan on methane production was exacerbated when PFOS was already present in the anaerobic enrichment cultures. Triclosan also had greater impacts on microbial community structures in the bottles that had been exposed to PFOS long-term. These results demonstrate that both chemical mixtures and exposure time are important parameters to address when trying to define the impacts of micropollutants on anaerobic microbial communities.

Changes in Liver Structure and Function after Short-Term and Long-Term Treatment of Rats with Dehydroepiandrosterone

1992 ◽  
Vol 122 (4) ◽  
pp. 967-976 ◽  
Author(s):  
Monica Bellei ◽  
Daniela Battelli ◽  
Claudio Fornieri ◽  
Giuseppe Mori ◽  
Umberto Muscatello ◽  
...  
Keyword(s):  
Term Treatment ◽  
Structure And Function ◽  
Short Term ◽  
Long Term Treatment ◽  
Liver Structure ◽  
And Function

scholarly journals Short-Term Disruption of Diurnal Rhythms After Murine Myocardial Infarction Adversely Affects Long-Term Myocardial Structure and Function

2014 ◽  
Vol 114 (11) ◽  
pp. 1713-1722 ◽  
Author(s):  
Faisal J. Alibhai ◽  
Elena V. Tsimakouridze ◽  
Nirmala Chinnappareddy ◽  
David C. Wright ◽  
Filio Billia ◽  
...  
Keyword(s):  
Myocardial Infarction ◽  
Structure And Function ◽  
Diurnal Rhythms ◽  
Short Term ◽  
Myocardial Structure ◽  
And Function

scholarly journals Dietary supplements for treating osteoarthritis: a systematic review and meta-analysis

2017 ◽  
Vol 52 (3) ◽  
pp. 167-175 ◽  
Author(s):  
Xiaoqian Liu ◽  
Gustavo C Machado ◽  
Jillian P Eyles ◽  
Varshini Ravi ◽  
David J Hunter
Keyword(s):  
Treatment Effects ◽  
Meta Analysis ◽  
Type Ii Collagen ◽  
Controlled Trials ◽  
Type Ii ◽  
Medium Term ◽  
Short Term ◽  
And Function ◽  
Undenatured Type Ii Collagen

ObjectiveTo investigate the efficacy and safety of dietary supplements for patients with osteoarthritis.DesignAn intervention systematic review with random effects meta-analysis and meta-regression.Data sourcesMEDLINE, EMBASE, Cochrane Register of Controlled Trials, Allied and Complementary Medicine and Cumulative Index to Nursing and Allied Health Literature were searched from inception to April 2017.Study eligibility criteriaRandomised controlled trials comparing oral supplements with placebo for hand, hip or knee osteoarthritis.ResultsOf 20 supplements investigated in 69 eligible studies, 7 (collagen hydrolysate, passion fruit peel extract, Curcuma longa extract, Boswellia serrata extract, curcumin, pycnogenol and L-carnitine) demonstrated large (effect size >0.80) and clinically important effects for pain reduction at short term. Another six (undenatured type II collagen, avocado soybean unsaponifiables, methylsulfonylmethane, diacerein, glucosamine and chondroitin) revealed statistically significant improvements on pain, but were of unclear clinical importance. Only green-lipped mussel extract and undenatured type II collagen had clinically important effects on pain at medium term. No supplements were identified with clinically important effects on pain reduction at long term. Similar results were found for physical function. Chondroitin demonstrated statistically significant, but not clinically important structural improvement (effect size −0.30, –0.42 to −0.17). There were no differences between supplements and placebo for safety outcomes, except for diacerein. The Grading of Recommendations Assessment, Development and Evaluation suggested a wide range of quality evidence from very low to high.ConclusionsThe overall analysis including all trials showed that supplements provided moderate and clinically meaningful treatment effects on pain and function in patients with hand, hip or knee osteoarthritis at short term, although the quality of evidence was very low. Some supplements with a limited number of studies and participants suggested large treatment effects, while widely used supplements such as glucosamine and chondroitin were either ineffective or showed small and arguably clinically unimportant treatment effects. Supplements had no clinically important effects on pain and function at medium-term and long-term follow-ups.

scholarly journals Cardiac structure and function in lowlanders at high altitude: short-term adaptation and chronic remodeling

2021 ◽  
Author(s):  
guyue liu ◽  
liming zhao ◽  
qing xu ◽  
rong xiao ◽  
mingjian lang
Keyword(s):  
Sea Level ◽  
Structure And Function ◽  
Cardiac Structure ◽  
Short Term ◽  
Right Heart ◽  
Short Term Exposure ◽  
Short Term Adaptation ◽  
Cardiac Structure And Function ◽  
And Function

Aims: The purpose of this study was to examine cardiac structure and function in lowlanders at high altitude(HA) to investigate short-term adaptation and long-term cardiac remodeling. Methods: In total of 301 healthy subjects included in this study, short-term exposed (STE) and acclimatized lowlanders (AL) at HA, native Tibetans(NT) and sea level residents(SLR) were comprised of 75,77,69 and 80 participants, respectively. Standard echocardiography was performed on all groups, subjects at HA were examined after return to sea level in <24 hours. Results: SBP and HR did not increase significantly after short-term exposure to HA in STE, but increased after long-term exposure in AL, which could be detected even after returning to the plain. Exposure to HA enlarged right heart, widened pulmonary artery and reduced left ventricular(LV) diastolic function in lowlanders. The degree of diastolic dysfunction was more obvious in AL. LV wall thickness increased even after short-term exposure to HA in lowlanders. Ejection fraction did not change significantly in STE, but decreased in AL. Conclusions: Exposure to HA could enlarged the right heart and decrease the diastolic function of LV in lowlanders. The LV systolic function was preserved after short-term HA exposure, but decreased after long-term HA exposure.

Lung Structure And Function Relation In Elastase-Treated Rats: A Long-Term Follow Up Study

2012 ◽  
Author(s):  
Margit V. Szabari ◽  
Jozsef Tolnai ◽  
Balazs Maar ◽  
Harikrishnan Parameswaran ◽  
Elizabeth Bartolak-Suki ◽  
...  
Keyword(s):  
Structure And Function ◽  
Follow Up Study ◽  
Lung Structure ◽  
Long Term Follow Up ◽  
And Function ◽  
Function Relation

Abstract P138: Long-term Effects Of Severe Caloric Restriction To The Heart Function

Hypertension ◽  
2021 ◽  
Vol 78 (Suppl_1) ◽  
Author(s):  
Aline M De Souza ◽  
Jonathas Almeida ◽  
Nataliia Shults ◽  
Hong Ji ◽  
Kathryn Sandberg
Keyword(s):  
Cardiovascular Disease ◽  
Caloric Restriction ◽  
Heart Function ◽  
Left Ventricular ◽  
Structure And Function ◽  
Long Term Effects ◽  
Isolated Hearts ◽  
Ad Libitum ◽  
And Function

Severe caloric restriction (sCR) increases the risk for acute cardiovascular disease. Less understood are the long-term effects on cardiovascular disease risk after the sCR period has ended. We investigated the effects of sCR on heart structure and function months after refeeding (sCR-Refed). Female Fischer rats (3-months-old) were maintained on (CT) ad libitum or a 60% caloric restricted diet for 2 weeks. Thereafter, all rats received ad libitum chow for 3 months and they were analyzed by precision ultrasound to assess their heart function. After imaging, the animals were sacrificed and the hearts were subjected to ischemia-reperfusion (I/R) using a Langendorff preparation. After 2 weeks of sCR, rats lost 15% of their initial body weight (BW) [% (100*(Final-Initial/Initial)): CT, 1.5±0.8 vs sCR, -15.4±1.1; p<0.001;n=8]. After 3 months of refeeding, there was no detectable difference in BW between CT and sFR-Refed groups. Isolated hearts from the sCR-Refed rats exhibited worse myocardial pathology after I/R compared to CT rats. The parallel orientation of myofibers and striations normally present in cardiomyocytes was lost in sCR-Refed rats. Further analysis revealed uneven blood-filling of the microcirculatory vessels and prominent interstitial edema of the myocardium. Hearts from sCR-Refed rats had more atrophied cardiomyocytes than CT [Atrophied/Total (%): CT, 0.2±0.1 vs sCR-Refed, 50.6±1.1; p<0.001; n=5]. The number of arrhythmic events during a 30 min ischemic interval in isolated hearts doubled after 2 weeks on the sCR diet ( data not shown ) and remained doubled 3 months later [Arrhythmias (% of time): CT, 34±8 vs sCR-Refed, 68±9; p=0.02; n=8]. Ultrasound imaging showed no difference in stroke volume, coronary perfusion pressure and left ventricular mass. However, the thickness of the left ventricular posterior wall was significantly reduced in sCR-Refed rats [(mm): CT, 2.55 ±0.03 vs sCR-Refed, 2.10±0.04; p=0.002; n=4]. These findings indicate heart structure and function remained damaged months after the sCR period ended and BW was restored. These studies have adverse cardiovascular risk implications for who are subjected either voluntarily (crash diets) or involuntarily (very low food security) to periods of inadequate caloric intake.

Long-term changes in structure and function of a tropical headwater stream following a disease-driven amphibian decline

2014 ◽  
Vol 60 (3) ◽  
pp. 575-589 ◽  
Author(s):  
Heidi M. Rantala ◽  
Amanda M. Nelson ◽  
Jessica N. Fulgoni ◽  
Matt R. Whiles ◽  
Robert O. Hall ◽  
...  
Keyword(s):  
Amphibian Decline ◽  
Structure And Function ◽  
Headwater Stream ◽  
Long Term Changes ◽  
And Function

scholarly journals Alterations of the thyroid structure and function in experimental hypopinealism

2011 ◽  
Vol 57 (2) ◽  
pp. 32-35
Author(s):  
L A Bondarenko ◽  
L Iu Sergienko ◽  
N N Sotnik ◽  
A N Cherevko
Keyword(s):  
Thyroid Gland ◽  
Structural Changes ◽  
Structure And Function ◽  
Initial Increase ◽  
Histological Structure ◽  
Pituitary Thyroid Axis ◽  
Thyroid Axis ◽  
And Function ◽  
Sexually Mature

The pituitary-thyroid axis of young sexually mature rabbits kept under a 24-hour daylight photoperiod was shown to undergo phase-modulated variations of hormonal activity with its initial increase (during the first month) and subsequent progressive decrease (within 2-5 months after the onset of exposure to light). These changes correlated with the time-dependent fall in the blood T3, T4, and TSH levels. Simultaneously, the animals developed pathological changes in the histological structure of the thyroid gland similar to those in patients with secondary or tertiary hypothyroidism. It is concluded that hormonal and structural changes in the thyroid gland during long-term hypopinealism should be regarded as an experimental model of hypothyroidism of neuroendocrine origin.

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