scholarly journals Thyroid hormone concentrations associated with age, sex, reproductive status and apparent reproductive failure in the Amazon river dolphin (Inia geoffrensis)

2019 ◽  
Vol 7 (1) ◽  
Author(s):  
T R Robeck ◽  
R S Amaral ◽  
V M F da Silva ◽  
A R Martin ◽  
G A Montano ◽  
...  

AbstractThis study was conducted to characterize immunoreactive thyroid hormone concentrations in wild Amazon river dolphins, also called boto (Inia geoffrensis) by age group, sex, pregnancy and lactation status, and to determine if thyroid hormone concentration differences could be detected between pregnant females with and without successful parturition outcomes. Radioimmunoassays were used to analyse total T3 and total T4 in 182 serum samples collected from 172 botos living in the Mamirauá Sustainable Development Reserve, in the Brazilian Amazon from 2003 through 2015. Age significantly affected tT3 and tT4 concentrations in males, with values in immature males and females being significantly lower than those in adult males, whereas no age effects were noted between immature females and adult non-pregnant, non-lactating females. Significant sex differences were noted in tT3 concentrations between immature males and females and in tT4 concentrations between adult males and females. These resulted in significant differences in the tT3:tT4 ratio between males and females within the immature and adult groups. Lactating and non-pregnant adult females had significantly higher tT3 concentrations than pregnant females, and this difference was primarily driven by a 12% drop in tT3 concentrations during the last two-thirds of pregnancy. No differences in thyroid hormone concentrations were detected between females diagnosed as pregnant and later found to have or not have a live calf. These results are the first to define thyroid hormone reference intervals and normal physiological variations in a wild population of river dolphins.

2020 ◽  
Vol 11 ◽  
pp. 204201882092268
Author(s):  
Qian Sun ◽  
Lívia Avallone ◽  
Brian Stolze ◽  
Katherine A. Araque ◽  
Yesim Özarda ◽  
...  

Background: There has been a wide range of reference intervals proposed in previous literature for thyroid hormones due to large between-assay variability of immunoassays, as well as lack of correction for collection time. We provided the diurnal reference intervals for five thyroid hormones, namely total thyroxine (TT4), total triiodothyronine (TT3), free thyroxine (FT4), free triiodothyronine (FT3), and reverse T3 (rT3), measured in serum samples of healthy participants using a liquid chromatography/tandem mass spectrometry (LC-MS/MS) method. Methods: Couplet serum samples (a.m. and p.m.) were collected from 110 healthy females and 49 healthy males. Healthy volunteers were recruited from four participating centers between 2016 and 2018. Measurements of thyroid hormones were obtained by LC-MS/MS analysis. Results: Our study revealed significant uptrend in AM to PM FT4 ( p < 0.0001) samples, downtrend in AM to PM TT3 ( p = 0.0004) and FT3 samples ( p < 0.0001), and AM to PM uptrend in rT3 samples ( p < 0.0001). No difference was observed for TT4 between AM and PM. No significant sex differences were seen for any of the five thyroid hormones. Conclusion: When diagnosing thyroid disorders, it is important to have accurate measurement of thyroid hormones, and to acknowledge the diurnal fluctuation found, especially for FT3. Our study highlights the importance of standardization of collection times and implementation of LC-MS/MS in thyroid hormone measurement.


2007 ◽  
Vol 85 (5) ◽  
pp. 653-664 ◽  
Author(s):  
M. Dietz ◽  
E.K.V. Kalko

Nearly all mammals in the temperate zone breed in spring and summer when climatic conditions are favourable and food is abundant. Similar to other mammals, food requirements of female bats are particularly high during pregnancy and lactation and of males during spermatogenesis. Seasonal changes in energy demand and reproductive condition should therefore result in different foraging activity within and between sexes. This assumption was tested on 16 adult females and 13 adult males of the Palaearctic Daubenton’s bat, Myotis daubentoni (Kuhl, 1817), that were radio-tracked during pregnancy, lactation, and post-lactation periods. Pregnant females, as hypothesized, flew significantly longer (mean: 358.9 min; 70% of the night length) than males (mean: 228.5 min; 42.4% of the night length) during spring. In contrast, nightly flight time of lactating females decreased and was significantly less than that of pregnant females, but was similar to that of males during the same period. The longest flight times of males were registered during late summer when spermatogenetic activity is high. However, there were distinct differences in the use of foraging areas between female and male Daubenton’s bats. Female bats used small, individual foraging areas during pregnancy and lactation. The pattern was reversed in females after the young had been weaned and in males after they entered spermatogenesis. Overall, the results confirmed our proposition that flight activity reflects the higher energy demand and nutrition requirements in the different reproductive periods.


2000 ◽  
Vol 27 (1) ◽  
pp. 91 ◽  
Author(s):  
T. Chekchak ◽  
J.-L. Chapuis ◽  
B. Pisanu ◽  
P. Boussès

Introductions of the rabbit flea, Spilopsyllus cuniculi (Dale), were made on an island (3.1 km2) of the Kerguelen subantarctic archipelago in January and December 1987. Despite a small founding population, the species succeeded in establishing itself. Three years after introduction, the rate of spread was 614 ± 133 m (between 1990 and 1993). Despite the subantarctic climate of Kerguelen, the burdens were similar to those noted in habitats favourable to this ectoparasite. The flea burden of adult rabbits after colonisation of the whole island was higher for pregnant females (182 ± 21, n = 98) than for non-pregnant ones (85 ± 16, n = 68) or males (20 ± 3, n = 116). The circulation of myxoma virus, present on this island for several decades, has been favoured by the flea. As a result, the proportion of rabbits with antibodies rose from 34% before introduction of the flea to 85% in 1998. Moreover, the introduction of fleas has changed the relative proportions of both adult males and females with antibodies. Those proportions were not different before the introduction but more males than females showed antibodies when the flea colonised the whole island. Finally, the prospects of the introduction of Spilopsyllus cuniculi on the main island of the archipelago are discussed.


2020 ◽  
Vol 66 (4) ◽  
pp. 556-566
Author(s):  
Rutchanna M S Jongejan ◽  
Theo Klein ◽  
Marcel E Meima ◽  
W Edward Visser ◽  
Ramona E A van Heerebeek ◽  
...  

Abstract Background While thyroxine (T4), 3,3’,5-triiodothyronine (T3), and 3,3’,5’-triiodothyronine (rT3) have routine methods available for evaluating patients with suspected thyroid disease, appropriate methods for the measurement of other thyroid hormone metabolites (THMs) are lacking. The effects of other iodothyronines or iodothyroacetic acids are therefore less explored. To better understand the (patho)physiological role of THMs, a robust method to measure iodothyronines and iodothyroacetic acids in serum in a single analysis is needed, including associated reference intervals. Methods Clinical and Laboratory Standards Institute guidelines, European Medicines Agency guidelines, and the National Institute of Standards and Technology protocol were used for the method validation and reference intervals. Reference intervals were determined in 132 healthy males and 121 healthy females. Serum samples were deproteinized with acetonitrile, followed by anion-exchange solid phase extraction and analysis with LC-MS/MS, using eight 13C6-internal standards Results The analytical method validation was performed for all nine THMs. Reference intervals (2.5th to 97.5th percentile) were determined for L-thyronine (4.9–11.3 ng/dL), 3-monoiodothyronine (0.06 --0.41 ng/dL), 3,5-diiodothyronine (&lt;0.13 ng/dL), 3,3’-diiodothyronine (0.25--0.77 ng/dL), T3 (66.4--129.9 ng/dL), rT3 (15.0--64.1 ng/dL), T4 (4.3--10.0 µg/dL), triac/3,3’,5-triiodothyroacetic acid (not detected), and tetrac/3,3’,5,5’-tetraiodothyroacetic acid (2.2--27.2 ng/dL). Conclusions A broad dynamic concentration range exists among the nine THMs. This method should help to develop a better understanding of the clinical relevance of other THMs, as well as an understanding of thyroid hormone metabolism in health and disease.


Author(s):  
Joseph D Sciurba ◽  
Jennifer M Hayes ◽  
Seyed Mehdi Nouraie ◽  
Heather M Wilson ◽  
Jeffrey D Fortman ◽  
...  

Thyroid diseases, associated with either increased or decreased concentrations of circulating thyroid hormones, are prevalent in both human and veterinary populations. Hypothyroidism is a differential diagnosis for many medical problems as the disease presents with nonspecific clinical signs that can include lethargy, weight gain, cold intolerance, and dermatologic manifestations such as alopecia. Alopecia is a frequently reported problem in captive nonhuman primates (NHP), and hypothyroidism is considered to be a differential diagnosis. However, thyroid function test results in NHP using total T4 (TT4) and free T4 (FT4) assays are difficult to interpret without accurate reference intervals (RI) for comparison. As a consequence,hypothyroidism may be underdiagnosed in these species. The objective of this study was to establish RI for TT4 and FT4 in healthy populations of cynomolgus macaques (n = 133; age range 2.6 to 24.7 y) and rhesus macaques (n = 172; age range 0.8 to 31.0 y). Serum samples were collected across a 14-y period during routine anesthetic events in clinically healthy animals, and TT4 and FT4 concentrations were measured using commercially available immunoassays. The RI established for TT4 andFT4 were 5.1 to 14.9 ug/dL and 0.48 to 1.17 ng/dL for cynomolgus macaques, and 3.9 to 14.7 ug/dL and 0.36 to 1.12 ng/dL for rhesus macaques. Significant differences in thyroid hormone concentrations were found between Indian and Chinese origin rhesus, and between Mauritian and other origin cynomolgus. In addition, juvenile and subadult rhesus exhibited significantly higher FT4 and TT4 concentrations than did older animals. Individual RI were established for subgroups with adequately different thyroid hormone concentrations. These results will allow a more thorough diagnostic evaluation of cynomolgus and rhesus macaques with clinical signs consistent with thyroid disease and will ultimately be a refinement in NHP medicine.


2018 ◽  
Vol 9 (9) ◽  
pp. 293-297 ◽  
Author(s):  
Nagi I. Ali ◽  
Abdullah O. Alamoudi ◽  
Ishag Adam

Background: Thyroid-stimulating hormone (TSH), thyroxin (T4) and T3 levels are varied in the different settings with disorders of thyroid homeostasis. It is recommended that every setting has to establish its own reference intervals (RIs) for these hormones. Methods: A multi-stage stratified sampling method was used to select a representative sample of a Sudanese adult (>20 years of age) in Nyala in western Sudan in the Darfur region during the period between January and June 2016 to establish RIs of thyroid-related hormones (TSH, T4 and T3). In this study, 1753 serum samples (male and female) with different age groups were investigated. A radioimmunoassay gamma counter was used to measure the level of these hormones. Results: The median (95% intervals) of serum TSH, T4 and T3 levels was 1.2 (0.50–3.0) mIU/l, 111.0 (72.0–161.0) nmol/l and 1.5 (0.8–2.8) nmol/l respectively. While the level of TSH was significantly higher in the age group between 31 and 40 years, both T4 and T3 levels have shown a progressive increase with age. There was no significant difference in the TSH, T4 and T3 level when the RIs were compared between males and females. Conclusion: The RIs for TSH, T4 and T3 in this setting were different from the levels provided by the manufacturers. The RIs were different in the different age groups.


2019 ◽  
Vol 53 (4) ◽  
pp. 325-334
Author(s):  
V. N. Peskov ◽  
N. A. Petrenko ◽  
V. Yu. Reminnyi

Abstract We study size-at-age and sexual variability of morphometric characteristics of the marsh frog. According to the size of the body, males were divided into three size-age groups (juvenis, subadultus, adultus), females — into four groups (juvenis, subadultus, adultus, adultus-I). We found that the chronological age of frogs (skeletochronology) does not always correspond to their biological age (size and proportions of the body). We noted that the semi-adult males are reliably larger than females by mean values of 26 studied morphometric characters. Males and females of “adultus” group do not differ by linear body size, significant differences were found in body proportions (7 characters). For the females of “adultus-I” group, the mean values of 26 characters are significantly larger than for “adultus” males. The results of our study showed that with the age of the marsh frog, the level of exhibition, directionality and structure of morphometric sex differences changes.


2020 ◽  
Vol 17 (1) ◽  
pp. 28-37
Author(s):  
Tabinda Sattar

Background: Selenium is a micronutrient, although required in low amounts, its importance in male and female reproduction is well known. Objectives: The core purpose of this study is to evaluate the role of selenium in human reproduction, during pregnancy/ lactation in women and newborns. The review explains side by side the sources of selenium, required amounts of selenium in humans and during pregnancy or lactation. Methods: Selenium deficiency is a major cause of male infertility. Similarly, selenium deficiency, both in pregnant and postpartum women, would greatly affect the health of the newborn baby in all respects. The effect of maternal selenium upon the fetus and the neonates even one year after birth has been explained with some recent examples. Results: The study elaborates the fact that the selenium deficiency in pregnancy and lactation is common due to fetal/infant development, so selenium supplements must be provided in order to overcome these deficiency symptoms. Conclusions: The better reproductive health in humans is possible due to the sufficient amounts of selenium present both in males and females as well.


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