Control of canine ACTH by corticosteroids: an integral feedback effect of steroids

1989 ◽  
Vol 257 (2) ◽  
pp. R427-R430 ◽  
Author(s):  
M. Keller-Wood
Keyword(s):  
Time Domain ◽  
Adrenocorticotropic Hormone ◽  
Corticosteroid Treatment ◽  
Steroid Treatment ◽  
Feedback Signal ◽  
Plasma Acth ◽  
Corticosteroid Dose ◽  
Treatment Changes ◽  
The Mean ◽  
Total Interval

These experiments were designed to test whether the pattern of change in plasma corticosteroid or the total corticosteroid dose is important in determining the degree of inhibition of adrenocorticotropic hormone (ACTH) responses to stress by corticosteroid intermediate-delayed feedback. Five conscious dogs were studied. The ACTH response to induced hypoglycemia was measured after no prior corticosteroid feedback signal or after a corticosteroid feedback signal produced by infusion, two bolus injections, or three bolus injections of cortisol and corticosterone. The total corticosteroid dose (45 micrograms/kg) and the total interval of steroid treatment (60-30 min before hypoglycemia) were the same in all three cases of corticosteroid treatment. Changes in plasma glucose concentration during induced hypoglycemia were not altered by corticosteroid treatment. The plasma ACTH response to hypoglycemia was inhibited by all three patterns of treatment with corticosteroids. The inhibition of ACTH response was not significantly altered among the patterns of treatment with corticosteroids. The data suggest that the integrated (total) or the mean change in plasma corticosteroid concentration over time determines the degree of inhibition of stimulated ACTH in this time domain.

scholarly journals Effect of delayed plasma centrifugation on equine adrenocorticotropic hormone concentration

2019 ◽  
Vol 31 (4) ◽  
pp. 585-587 ◽  
Author(s):  
Kayla N. Shepard ◽  
John C. Haffner ◽  
Dwana L. Neal ◽  
Steven T. Grubbs ◽  
Greg L. Pearce
Keyword(s):  
Whole Blood ◽  
Adrenocorticotropic Hormone ◽  
Animal Health ◽  
Pars Intermedia ◽  
Plasma Acth ◽  
Cornell University ◽  
Diagnostic Center ◽  
Acth Concentration ◽  
Baseline Values ◽  
The Mean

Plasma adrenocorticotropic hormone (ACTH) concentration is used in the diagnosis of pituitary pars intermedia dysfunction (PPID) in horses. We enrolled 10 horses, 5 PPID-positive and 5 PPID-negative, in our study, September 20–22, 2016. On day 0, 5 mL of whole blood was collected into each of 6 EDTA tubes and immediately placed in a refrigerator at 7°C. One tube was centrifuged within 15 min of collection, followed by centrifugation of one tube from each horse at 4, 8, 12, 24, and 36 h following collection. At each time, centrifuged plasma was pipetted into 1.5-mL polypropylene tubes and stored at −80°C. None of the plasma samples were turbid, hemolyzed, or icteric. Plasma was shipped frozen with cold packs overnight to the Animal Health Diagnostic Center of Cornell University (Ithaca, NY) for analysis. The percent change from baseline (PCFB) was reported to standardize the data given that baseline values differed. The mean PCFB was 2.8 (95% confidence interval: –2.9%, 7.0%). Neither refrigeration of whole blood for up to 36 h prior to centrifugation nor freezing affected plasma ACTH concentrations significantly.

Corticotropin responses to hypoglycemia and hypotension during ovine pregnancy

1994 ◽  
Vol 266 (1) ◽  
pp. R180-R187
Author(s):  
M. Keller-Wood
Keyword(s):  
Adrenocorticotropic Hormone ◽  
Regular Insulin ◽  
Plasma Acth ◽  
Specific Effects ◽  
Arterial Blood ◽  
Multiple Stimulus ◽  
The Mean ◽  
Pregnant State ◽  
The Right ◽  
Pituitary Adrenal Axis

The adrenocorticotropic hormone (ACTH) responses to hypoglycemia and to hypotension were compared in pregnant and nonpregnant ewes. In the first study pregnant and nonpregnant ewes were each subjected to hypoglycemia induced by injection of 0.05, 0.10, or 0.25 U regular insulin/kg body wt or to saline infused as a control. In the second study pregnant and nonpregnant ewes were subjected to hypotension induced by the infusion of 2.5, 5.0, or 10.0 micrograms nitroprusside.kg-1.min-1 or to dextrose infused as a control. ACTH responses to hypoglycemia were significantly increased in the pregnant ewes, and the relation between plasma glucose and plasma ACTH was shifted to the right, indicating greater ACTH responses for a given level of hypoglycemia in the pregnant state. The mean ACTH response to infusion of nitroprusside was reduced during pregnancy, despite significantly lower mean arterial blood pressure in the pregnant ewes. When the relation between mean arterial pressure and ACTH was compared in the two groups of ewes, the relation was significantly shifted to the left in the pregnant ewes, indicating lower ACTH responses to a given level of pressure during pregnancy. The results suggest that pregnancy does not uniformly alter ACTH responses to stimuli, suggesting multiple, stimulus-specific effects of pregnancy on the hypothalamo-pituitary-adrenal axis.

scholarly journals Macrolide-Resistant and Macrolide-Sensitive Mycoplasma pneumoniae Pneumonia in Children Treated Using Early Corticosteroids

2021 ◽  
Vol 10 (6) ◽  
pp. 1309
Author(s):  
Hye Young Han ◽  
Ki Cheol Park ◽  
Eun-Ae Yang ◽  
Kyung-Yil Lee
Keyword(s):  
Mycoplasma Pneumoniae ◽  
Serological Test ◽  
Corticosteroid Treatment ◽  
23S Rrna ◽  
Laboratory Parameters ◽  
The Mean ◽  
Domain V ◽  
Positive Results ◽  
Mycoplasma Pneumoniae Pneumonia

We have found that early corticosteroid therapy was effective for reducing morbidity during five Korea-wide epidemics. We evaluated the clinical and laboratory parameters of 56 children who received early corticosteroid treatment for pneumonia that was caused by macrolide-resistant Mycoplasma pneumoniae (M. pneumoniae) or macrolide-sensitive M. pneumoniae between July 2019 and February 2020. All subjects had dual positive results from a PCR assay and serological test, and received corticosteroids within 24–36 h after admission. Point mutation of residues 2063, 2064, and 2067 was identified in domain V of 23S rRNA. The mean age was 6.8 years and the male:female ratio was 1.2:1 (31:25 patients). Most of the subjects had macrolide-resistant M. pneumoniae (73%), and all mutated strains had the A2063G transition. No significant differences in clinical and laboratory parameters were observed between macrolide-resistant and macrolide-sensitive M. pneumoniae groups that were treated with early dose-adjusted corticosteroids. Higher-dose steroid treatment may be needed for patients who have fever that persists for >48 h or increased biomarkers such as lactate dehydrogenase concentration at follow-up despite a usual dose of steroid therapy.

scholarly journals Prediction of shallow bit position based on vibration signal monitoring of bit broken rock

2021 ◽  
Vol 17 (1) ◽  
pp. 155014772199170
Author(s):  
Jinping Yu ◽  
Deyong Zou
Keyword(s):  
Acoustic Emission ◽  
Time Domain ◽  
Vibration Signal ◽  
Rock Breaking ◽  
Drill String ◽  
Mean Square ◽  
Drilling Force ◽  
Emission Signal ◽  
Force Signal ◽  
The Mean

The speed of drilling has a great relationship with the rock breaking efficiency of the bit. Based on the above background, the purpose of this article is to predict the position of shallow bit based on the vibration signal monitoring of bit broken rock. In this article, first, the mechanical research of drill string is carried out; the basic changes of the main mechanical parameters such as the axial force, torque, and bending moment of drill string are clarified; and the dynamic equilibrium equation theory of drill string system is analyzed. According to the similarity criterion, the corresponding relationship between drilling process parameters and laboratory test conditions is determined. Then, the position monitoring test system of the vibration bit is established. The acoustic emission signal and the drilling force signal of the different positions of the bit in the process of vibration rock breaking are collected synchronously by the acoustic emission sensor and the piezoelectric force sensor. Then, the denoised acoustic emission signal and drilling force signal are analyzed and processed. The mean value, variance, and mean square value of the signal are calculated in the time domain. The power spectrum of the signal is analyzed in the frequency domain. The signal is decomposed by wavelet in the time and frequency domains, and the wavelet energy coefficients of each frequency band are extracted. Through the wavelet energy coefficient calculated by the model, combined with the mean, variance, and mean square error of time-domain signal, the position of shallow buried bit can be analyzed and predicted. Finally, by fitting the results of indoor experiment and simulation experiment, it can be seen that the stress–strain curve of rock failure is basically the same, and the error is about 3.5%, which verifies the accuracy of the model.

Rigorous time-domain analysis of statistically oriented graphene sheet fluctuations

2017 ◽  
Vol 36 (5) ◽  
pp. 1351-1363 ◽  
Author(s):  
Athanasios N. Papadimopoulos ◽  
Stamatios A. Amanatiadis ◽  
Nikolaos V. Kantartzis ◽  
Theodoros T. Zygiridis ◽  
Theodoros D. Tsiboukis
Keyword(s):  
Monte Carlo ◽  
Standard Deviation ◽  
Finite Difference ◽  
Surface Waves ◽  
Time Domain ◽  
Finite Difference Time Domain ◽  
Mean Value ◽  
Content Type ◽  
The Mean ◽  
Difference Time

Purpose Important statistical variations are likely to appear in the propagation of surface plasmon polariton waves atop the surface of graphene sheets, degrading the expected performance of real-life THz applications. This paper aims to introduce an efficient numerical algorithm that is able to accurately and rapidly predict the influence of material-based uncertainties for diverse graphene configurations. Design/methodology/approach Initially, the surface conductivity of graphene is described at the far infrared spectrum and the uncertainties of its main parameters, namely, the chemical potential and the relaxation time, on the propagation properties of the surface waves are investigated, unveiling a considerable impact. Furthermore, the demanding two-dimensional material is numerically modeled as a surface boundary through a frequency-dependent finite-difference time-domain scheme, while a robust stochastic realization is accordingly developed. Findings The mean value and standard deviation of the propagating surface waves are extracted through a single-pass simulation in contrast to the laborious Monte Carlo technique, proving the accomplished high efficiency. Moreover, numerical results, including graphene’s surface current density and electric field distribution, indicate the notable precision, stability and convergence of the new graphene-based stochastic time-domain method in terms of the mean value and the order of magnitude of the standard deviation. Originality/value The combined uncertainties of the main parameters in graphene layers are modeled through a high-performance stochastic numerical algorithm, based on the finite-difference time-domain method. The significant accuracy of the numerical results, compared to the cumbersome Monte Carlo analysis, renders the featured technique a flexible computational tool that is able to enhance the design of graphene THz devices due to the uncertainty prediction.

scholarly journals Endocrine and Electrolyte Balances during Periovulatory Period in Cycling Mares

Animals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 520 ◽  
Author(s):  
Katiuska Satué ◽  
Esterina Fazio ◽  
Ana Muñoz ◽  
Pietro Medica
Keyword(s):  
Estrous Cycle ◽  
Hpa Axis ◽  
Adrenocorticotropic Hormone ◽  
Venous Blood ◽  
Competitive Elisa ◽  
Direct Relation ◽  
Plasma Acth ◽  
Blood Samples ◽  
Hypothalamic Pituitary Adrenal ◽  
Stimulation Of

In cycling females, the periovulatory period is characterized by stimulation of the hypothalamic pituitary adrenal (HPA) axis. The aim of present study was to analyze the pattern and interrelationships among adrenocorticotropic hormone (ACTH), cortisol (CORT), aldosterone (ALD) and electrolytes (sodium—Na+, potassium—K+ and chloride—Cl−) during periovulatory period in cycling mares. Venous blood samples were obtained daily from a total of 23 Purebred Spanish broodmares, aged 7.09 ± 2.5 years, from day −5 to day +5 of estrous cycle, considering day 0, the day of ovulation. Plasma ACTH was measured by a fluorescent immunoassay kit, serum CORT and ALD by means of a competitive ELISA immunoassay, and plasma Na+, K+ and Cl− were quantified by an analyzer with selective electrodes for the three ions. ACTH showed higher concentrations at day 0 compared to days −5 to −1 and +1 to +3 (p < 0.05). CORT showed higher concentrations at day 0 compared to days −5 to −2 and +1 to +5 (p < 0.05). ALD showed higher concentrations at day 0 compared to days −5 to −2 (p < 0.05) and +2 (p < 0.05). Na+ and Cl− showed higher concentrations at day 0, compared to day −5 and +5. K+ showed lower concentrations at day 0 compared to day +1 (p < 0.05). The significant correlations obtained between ACTH and CORT (r = 0.20) and between ACTH and ALD (r = 0.32) suggest that although ACTH may have an effect both on CORT and ALD, there are other very important determinants that could be considered. Hence, it is possible to presume that the pituitary adrenocortical response and ALD may be involved in the ovulatory mechanisms without a direct relation with electrolyte pattern.

Evaluation of Prenatal Transportation Stress on the Number of Pituitary Corticotrophs in Mature Brahman Cows

2021 ◽  
Vol 99 (Supplement_2) ◽  
pp. 24-25
Author(s):  
Victoria Kamilar ◽  
Sarah West ◽  
Brittni P Littlejohn ◽  
Charles R Long ◽  
David G Riley ◽  
...  
Keyword(s):  
Fetal Programming ◽  
Anterior Pituitary ◽  
Adrenocorticotropic Hormone ◽  
Developmental Changes ◽  
Control Group ◽  
Midsagittal Plane ◽  
Gland Weight ◽  
Group Control ◽  
The Mean ◽  
Transportation Stress

Abstract Prenatal transportation stress (PNS) results in calves that are more temperamental and have greater circulating concentrations of cortisol compared to control calves. The objective of this experiment was to evaluate whether PNS alters the number of pituitary corticotrophs in mature Brahman cows. We hypothesized that the increased circulating cortisol concentrations previously characterized in this bovine model is associated with developmental changes in the anterior pituitary leading to an increased number of corticotrophs. Pregnant Brahman cows (n = 48) were transported in trailers for 2-hour periods at 60±5, 80±5, 100±5, 120±5, and 140±5 days of gestation. Non-transported pregnant cows (n = 48) were designated as the Control group. Control and PNS offspring heifers were managed together under the same environmental conditions. At approximately 5 yr of age, randomly selected non-pregnant cows (Control, n = 8; PNS, n = 6) were humanely harvested and the whole pituitaries were collected. Pituitaries were weighed, fixed in paraformaldehyde, serially dehydrated with graded ethanol, embedded in paraffin blocks, and cut into 5-μm sections. Immunohistochemistry was performed to detect cells expressing adrenocorticotropic hormone (ACTH) as a marker for corticotrophs. Three comparable sections from the midsagittal plane from each animal were processed using an ovine ACTH-specific antibody (Dr. A.F. Parlow, NIDDK). Five fields of view were analyzed per section (15 fields per animal). Anterior pituitary gland weight did not differ (P &gt; 0.10) between groups (Control = 2.11 ± 0.12 g; PNS = 2.10 ± 0.15 g). The mean number of ACTH-positive cells between control (531±56 cells/section) and PNS cows (477±49 cells/section) also did not differ (P &gt; 0.10). In conclusion, the number of pituitary corticotrophs in mature Brahman cows was not affected by prenatal transportation stress and is likely not a mechanism mediating the increased circulating cortisol concentrations seen in this bovine model of fetal programming.

scholarly journals Feline plasma adrenocorticotropic hormone: validation of a chemiluminescent assay and concentrations in cats with hypercortisolism, primary hypoadrenocorticism and other diseases

2020 ◽  
pp. 1098612X2092568
Author(s):  
Antonio M Tardo ◽  
Claudia E Reusch ◽  
Sara Galac ◽  
Sofia Fornetti ◽  
Alessandro Tirolo ◽  
...  
Keyword(s):  
Adrenocorticotropic Hormone ◽  
Reference Interval ◽  
Robust Methods ◽  
Hormone Concentration ◽  
Plasma Acth ◽  
Naturally Occurring ◽  
Assay Precision ◽  
Diagnostic Work ◽  
Work Up ◽  
Interassay Precision

Objectives The aims of this study were to validate a commercially available chemiluminescent assay for measurement of feline plasma adrenocorticotropic hormone concentration (ACTH), to determine the normal reference interval (RI) of plasma ACTH in healthy cats, to assess plasma ACTH in cats with naturally occurring hypercortisolism (HC), primary hypoadrenocorticism (PH) and other diseases (OD), and to evaluate the effect of aprotinin on plasma ACTH degradation. Methods Forty healthy cats, 10 with HC, 11 with PH and 30 with OD, were included. The chemiluminescent enzyme immunometric assay was evaluated by measurement of intra-assay precision, interassay precision and linearity. The RI for plasma ACTH in healthy cats was established using robust methods. Plasma ACTH of samples collected with and without aprotinin, stored at 4°C and assayed over a 6-day period, was measured. Results The intra-assay coefficients of variance (CVs) ranged from 2.7% to 4.3% and interassay CVs from 3.3% to 10.7%. Dilution studies showed excellent accuracy (R2 >0.99). The RI for plasma ACTH in healthy cats was 32–370 pg/ml. Plasma ACTH was not significantly different between healthy cats and the OD group. Cats with pituitary-dependent hypercortisolism (PDH) and PH had significantly higher plasma ACTH than the other groups. Plasma ACTH did not show significant differences when samples collected with and without aprotinin were compared. Conclusions and relevance The Immulite chemiluminescent assay is a valid technique for measuring plasma ACTH in cats and the RI of plasma ACTH is quite wide. Owing to the low overlap between healthy or OD cats and cats with HC or PH, the measurement of plasma ACTH appears to be useful and should be included in the diagnostic work-up when HC or PH are suspected. Furthermore, the measurement of plasma ACTH may be an accurate test for differentiating PDH from adrenal-dependent hypercortisolism.

scholarly journals Role of Type and Volume of Recreational Physical Activity on Heart Rate Variability in Men

2020 ◽  
Vol 17 (8) ◽  
pp. 2719 ◽  
Author(s):  
Shaea Alkahtani ◽  
Andrew A. Flatt ◽  
Jawad Kanas ◽  
Abdulaziz Aldyel ◽  
Syed Shahid Habib
Keyword(s):  
Physical Activity ◽  
Heart Rate ◽  
Time Domain ◽  
Active Group ◽  
Control Groups ◽  
Rr Intervals ◽  
The Mean ◽  
And Control ◽  
Arab Men ◽  
Frequency Power

The aim of this study was to investigate the effect of recreational aerobic physical activity (PA) type and volume on heart rate variability (HRV) in Arab men. This was a retrospective, cross-sectional study, and included men (n = 75, age = 37.6 ± 7.1 years, body mass index (BMI) = 26.7 ± 3.1 kg/m2) who were members of a walking group, cycling group, or were inactive controls. Monthly distances from the past three months were obtained from walking and cycling groups, and the volume of PA was classified into three subgroups (high, moderate, low). HRV was measured using a computerized electrocardiographic data acquisition device. R–R interval recordings were performed while participants rested in a motionless supine position. RR intervals were recorded for 15 minutes, and a five-minute segment with minimal ectopic beats and artifacts was selected for HRV analysis. Time-domain parameters included the mean R–R interval, standard deviation of the mean R–R interval (SDNN), and root-mean-squared difference of successive RR intervals (RMSSD). The frequency-domain parameters included high-frequency power (HF), low-frequency power (LF), and LF to HF ratio (LF/HF). Results showed that there were no significant differences between walking, cycling, and control groups for all HRV parameters. Time-domain analyses based on PA volume showed that age-adjusted SDNN for the high-active group was greater than the low-active group (P = 0.03), and RMSSD for the moderate-active group was greater than the control group (P = 0.009). For the frequency domain, LF for the high-active group was greater than the low-active and control groups (P = 0.006), and HF for the moderate-active group was greater than the low-active group (P = 0.04). These data indicate that walking >150 km per month, or cycling >100 km per month at a speed >20 km/h may be necessary to derive cardiac autonomic benefits from PA among Arab men.

Effect of ovariectomy on vasopressin, ACTH, and renin activity responses to hypotension

1991 ◽  
Vol 261 (1) ◽  
pp. R223-R230 ◽  
Author(s):  
M. Keller-Wood ◽  
C. E. Wood
Keyword(s):  
Plasma Renin Activity ◽  
Arginine Vasopressin ◽  
Adrenocorticotropic Hormone ◽  
Plasma Renin ◽  
Renin Activity ◽  
Plasma Acth ◽  
Blood Samples

The gonadal axis is thought to modulate adrenocorticotropic hormone (ACTH), arginine vasopressin (AVP), and plasma renin activity (PRA) responses to stimuli in several species. These experiments were designed to compare the responses to hypotension in chronically ovariectomized ewes and intact ewes. The ewes were infused with nitroprusside at rates of 5, 10, or 15 micrograms.kg-1.min-1 or infused with vehicle for 10 min. The response to 15 micrograms.kg-1.min-1 was also tested with or without treatment with 10 mg of dexamethasone 2 h before nitroprusside. Blood samples were collected before and at 5, 10, 15, 20, and 30 min after the start of the infusion for measurement of plasma ACTH, AVP, and PRA. In both groups of animals there were significant responses to hypotension. There was a significant effect of ovariectomy on ACTH, AVP, and PRA responses. ACTH and PRA responses were lower in the ovariectomized ewes; AVP responses were increased in the ovariectomized ewes. Administration of dexamethasone inhibited ACTH responses and did not inhibit PRA responses in both groups of ewes. Administration of dexamethasone did not inhibit the AVP response in the intact ewes but did reduce the response in the ovariectomized ewes.

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