Thyroxine Concentrations Research Articles

Changes of the Heart Rhythm in Imbalance of Thyroid Gland Hormones and its Morphology in Outbred Rats

To analyze the relationship between the occurrence of atrial fibrillation (AF) and thyroid dysfunction caused by low concentrations of free triiodothyronine (FT3), free triiodothyronine and free thyroxine (FT3 and FT4), and high concentrations of free thyroxine (FT4) with normal values of thyroid-stimulating hormone (TSH) in experiments on outbred rats. The pathogenesis of AF with low concentrations of FT3, FT3 and FT4, and a high concentration of FT4 was studied in an experiment on 146 outbred rats. In the experiment, hypothyroidism, euthyroidism, and thyrotoxicosis were modeled by changing the concentrations of thyroid hormones, and the effect of these conditions on ECG and the incidence of AF was evaluated. The types of the hypothalamic-pituitary-thyroid system response to the L-thyroxine administration in experimental hypothyroidism were identified. A relationship was determined between AF paroxysms and threshold values of thyroid hormones at low concentrations of FT3, FT3 and FT4, and a high concentration of FT4 with normal TSH values. It was shown that achieving the euthyroid status did not reduce the incidence of AF paroxysms by more than 70.0%. In AF with low FT3, low FT3 and FT4, and high FT4, the dose of L-thyroxine must be adjusted.

Changes in Erythrocytes in 88 Hyperthyroid Cats.

There is only a limited number of studies that show alterations in erythrocytes in feline hyperthyroidism. Discrepancies between the findings of these studies may be caused by the presence of concurrent diseases and the use of various haematological analysers. This study analysed changes in red blood cells (RBCs) in 88 hyperthyroid cats without concurrent diseases, to identify associations between observed changes and to assess the influence of serum thyroxine (T4) concentration, cat age, and sex, on RBC changes. Among the eighty-eight hyperthyroid cats, erythrocytosis was observed in twelve, anaemia in four, macrocytosis in two, and microcytosis in three. Three of the four cases of anaemia probably resulted from concurrent unrecognised disease. Interestingly, all cases of microcytosis were recognized in cats that had erythrocytosis. This study identified a moderate negative correlation between RBC count and mean corpuscular volume (MCV; r = -0.57, p < 0.001). Concluding, it appears that erythrocytosis may be a response to the development of microcytosis. The correlation between RBC count and MCV in hyperthyroid cats may result from the increased action of hepcidin and erythropoietin coupled with the decreased action of thyroid-stimulating hormone (TSH).

Alteration of the gut microbiota changes during the one-year Antarctic deployment in a group of Chinese Han population

BackgroundIt is common knowledge that people’s intestinal microbiota is significantly influenced by the external environment. Although the Antarctic continent has been discovered for nearly 200 years, it is still unclear how this environment affects the human intestinal microbiota, especially that of the Chinese Han population.MethodsTwelve explorers underwent a one-year Antarctic deployment from December 2017 to December 2018. The gut microbiota and clinical indexes at five time points, including two months (T1), five months (T2), eight months (T3), 11 months (T4) of residence in Antarctica and 7 months after returning to China (T5), were investigated.ResultsThe intestinal microbiota of the participants was changed after one-year Antarctic deployment even after they left Antarctica. For the microbiota tested after returning to China (T5), the amount of Citrobacter, Akkermansia and conditional pathogens such as Escherichia-Shigella increased significantly (P < 0.05). The concentration of the major biochemical indicators in the serum exhibited an increasing trend before T3, and decreased significantly at T4. When tested again at T5, most of the serum concentrations increased, only 5-hydroxytryptamine was significantly decreased. Spearman correlation analysis showed the change in the relative abundance of Anaerotruncus was negatively associated with the changes in the concentration of total thyroxine, alanine transaminase, γ-glutamyl transpeptidase, serum cystatin C and apolipoprotein A1. The relative abundance change in Citrobacter was positively associated with the change in the concentration of uric acid.ConclusionBy objectively analyzing the influence of the Antarctic environment on the change of intestinal microbiota, we were able to provide theoretical support for subsequent Antarctic related research.

Propylthiouracil thyroid manipulation positively affects the metabolic adaptability of primiparous dairy cows to early lactation requirements

The study examined effects of thyroid manipulation with propylthiouracil (PTU) on the metabolic adaptability of transitional dairy cows to early lactation. The study included 30 primiparous Holstein-Friesian cows, which were divided into two groups: PTU+ (n = 15; received orally 4 mg/kg PTU during 20 days before expected calving) and PTU− (n = 15; did not receive orally PTU). Blood was sampled from each cow consecutively from − 20, − 17, − 13, − 5, − 4, − 3, − 2, and − 1 days before the expected term of calving, calving day (0), and + 1, + 2, + 3, + 4, + 5, + 10, + 15, + 30 and + 60 days after the calving to measure thyroid stimulating hormone (TSH), triiodothyronine (T3), thyroxine (T4), insulin, glucose, beta-hydroxybutyrate (BHB), bilirubin, total protein and albumin concentrations. Liver samples were biopsied at −7 ± 2 and +7 day relative to calving from both groups of cows to determine deiodinase (DIO) expressions and fat and glycogen content. Additionally, milk yield was monitored during the first 60 days of lactation. PTU successfully induced thyroid suppression by significantly reducing T3 and T4 concentrations and hepatic DIO1 expressions and caused PTU+ cows to have significantly higher insulin and glucose concentration in the precalving period. After calving, PTU+ cows had higher insulin and glucose concentration, liver glycogen content and overall milk production, lower BHB concentration, BCS loss, and liver fat deposits. Accordingly, cows treated with PTU have a more favourable energy balance and metabolic adaptation to early lactation.

Sensitivity Analysis in Mathematical Models of the Hypothalamus-Pituitary-Thyroid Axis

Mathematical models are promising and important for advancing the current medical practice in the field of endocrinology. To assess the reliability of the range of mathematical models describing the hypothalamuspituitary- thyroid axis and to establish their applicability in clinical decision support, we conducted a local and global sensitivity analysis of the model. Thyroid regulation in euthyroid and diseased individuals may be quantified and dynamic behavior predicted through mathematical models, thereby revolutionizing the current clinical practice. We investigated the influence of model parameters of a selected mathematical model utilizing ordinary differential equations describing the HPT-axis. Motivated by a graphical depiction of the varying influence of the model parameters, feasible methods such as a local sensitivity analysis are conducted. Furthermore, to account for the influence of parameters on the output variance of the considered model, the theory of Sobol’ indices is utilized. Although the system of differential equations describing the hormone concentrations of thyroid-simulating hormones and unbound Thyroxine has similar equation structures, the results of the sensitivity analyses varied according to the equation.

Thyroid function tests in healthy kittens aged between 2 and 16 weeks.

This study aimed to determine thyroid hormone concentrations in a cohort of healthy kittens due to the paucity of information in the literature, and the potential for congenital hypothyroidism (CH) to contribute to fading kitten syndrome (FKS). The serum concentrations of total thyroxine (TT4), free thyroxine (fT4), total triiodothyronine (TT3), free triiodothyronine (fT3) and thyroid-stimulating hormone (TSH) were measured in 19 healthy kittens aged 2-16 weeks. Mean TT4, fT4, TT3 and fT3 concentrations significantly differed across age groups. Mean TT4 and fT4 concentrations peaked at 6 and 5 weeks of age, respectively. The TT4 concentration exceeded the adult cat reference interval (ACRI) in 54% (32/59) of samples at week 6, with the highest TT4 concentration being 7.1 µg/dl (91 nmol/l). Mean TT3 and fT3 concentrations also peaked at 6 weeks of age. Mean TT3 concentration started below the ACRI until 4 weeks of age, after which it remained within the ACRI. The mean fT3 concentration was within the ACRI at all ages. The mean TSH concentration did not differ across age groups and remained within the ACRI in nearly 100% of samples. Peak TT4, fT4, TT3 and fT3 concentrations in healthy kittens at 5 and 6 weeks of age are likely due to changes in the maternal transfer of thyroid hormones after weaning and organ system development. Knowing healthy neonatal and pediatric thyroid hormone concentrations in a cohort of kittens might help a veterinarian interpret thyroid hormone levels when trying to rule out CH in a kitten with FKS.

Exposure to PM2.5 and its constituents in relation to thyroid function of pregnant women: Separate and mixture analyses

The relationships between exposure to PM2.5 and its constituents and thyroid hormone (TH) levels in pregnant women are still uncertain, particularly regarding the impact of mixed exposure to PM2.5 constituents on thyroid function during pregnancy. This study aimed to investigate the individual and mixed effect of PM2.5 and its constituents on TH levels during pregnancy. Fluorescence and chemiluminescence immunoassays were utilized to measure serum concentrations of free thyroxine (FT4) and thyroid-stimulating hormone (TSH) in pregnant women participating in the Fujian Birth Cohort Study (FJBCS). PM2.5 and its constituents were obtained from the ChinaHighAirPollutants dataset. Generalized linear regression model and mixture analysis were applied to explore the individual and mixed effect of PM2.5 and its constituents on TH levels. 13711 participants from the FJBCS were taken into the final analysis. In the context of separate exposure, an increase of one interquartile range (IQR) in PM2.5 exposure during the 1st trimester, 2nd trimester, and entire pregnancy was associated with a decrease of −0.042 (−0.050, −0.034), −0.017 (−0.026, −0.009), and −0.011 (−0.017, −0.004) in FT4 level, respectively. As well, significant negative associations were observed between FT4 level and PM2.5 constituents. Additionally, PM2.5 and its constituents were in relation to an increased risk of hypothyroxinemia in pregnant women. It is noteworthy that, in the context of mixed exposure, the weighted quantile sum regression (WQS) indices were significantly associated with both FT4 level (1st trimester: −0.031 (−0.036, −0.026); 2nd trimester: −0.026 (−0.030, −0.023); whole pregnancy: −0.024 (−0.028, −0.020)) and hypothyroxinemia risk (1st trimester: 1.552 (1.312, 1.821); 2nd trimester: 1.453 (1.194, 1.691); whole pregnancy: 1.402 (1.152, 1.713)). PM2.5 and its chemical constituents may affect thyroid function in pregnant women individually and in combination, with the effect observed during early gestational exposure being most pronounced.

Relationship of Polycystic Ovaries with some Hormones

The study aims to determine the relationship of polycystic ovaries with LH, FSH, Prolactin, Testosterone, Estrogen, T4, T3 hormones, fertility, hirsutism and acne. The sample was divided into two groups; the first group includes 200 women with polycystic ovaries and the second group is the control group which includes 25 healthy women.The results showed a significant decrease (P≤0.01) in FSH and T3 in the first group compared with control group and a significant increase((p≤0.05), (P≤0.01) ) in LH, Prolactin, Testosterone, Estrogen, T4 compared with control groups and 40 % of 134 married women did not get pregnant after ( 1-7) years of marriage , 5 % are suffered abortion without giving birth any child and among the 200 infected women with PCOS There were %26 of them suffering from hirsutism and acne and %32 suffering from hirsutism only and %11 acne only. There is relationship between the concentration of LH, FSH, Prolactin, Testosterone, Estrogen, Thyroxin, hirsutism and acne with development of PCOS and its impact on fertility.

Changes in the level of immune checkpoints in patients with various forms of autoimmune thyroiditis

Background. Autoimmune thyroiditis (AIT) affects more than 5 % of the world’s population.The aim. To determine the level of sPD-1, sPD-L1, sCTLA-4 and sB7.2 molecules in individuals suffering from various forms of autoimmune thyroiditis.Methods. The study included 31 individuals aged 18 to 40 years. They were divided into four groups: group I – healthy individuals (n = 10); group II – carriers of antibodies to thyroid peroxidase (n = 11); group III – individuals with AIT accompanied with subclinical form of hypothyroidism (n = 6); group IV – individuals with AIT complicated by compensated hypothyroidism (n = 4). Venous blood was collected to determine the level of antibodies to thyroid peroxidase using enzyme immunoassay, the concentration of thyroid stimulating hormone and free thyroxine – using chemiluminescence immunoassay, and the levels of sPD-1, sPD-1L, sCTLA-4, and sB7.2 – using flow cytofluorometry. Statistical processing was performed using the Kruskal – Wallis one-way analysis of variance.Results. When comparing the level of sPD-1L in groups I (54.1 (28.7; 67.6) pg/ml) and II (4.36 (2.36; 18.0) pg/ml), the decreased in this indicator was 91.94 % (p = 0.001). When comparing the sPD-1 level in the group of healthy individuals (16.6 (13.6; 37.2) pg/ml) and group IV (7.28 (5.18; 11.1) pg/ml), werecorded a decrease of 56.14 % (p = 0.001). The sB7.2 concentration decreased by 65.03 % in group II (16.4 (15.6; 32.7) pg/ml) compared to the control group (46.9 (39.3; 54.4) pg/ml) (p = 0.001). In group III, the sCTLA-4 level was 3.22 (3.06; 3.33) pg/ml and decreased by 88.66% compared to the control group (p = 0.001).Conclusion. The development of autoimmune thyroiditis is accompanied with the decrease in the concentration of sPD-1, sPD-1L, sCTLA-4 and sB7.2.

Effect of highly-active antiretroviral therapy on neuroendocrine regulation of immunogenesis in HIV-infected children

Comparative assay has been made against the parameters of the immune and endocrine systems in 84 HIV-infected children born from HIV-infected mothers. One group of analyzed children (36 patients) did not receive highly-active antiretroviral therapy. Another group (48 patients) received different variants of highly-active antiretroviral therapy. Children aged from 1 to 182 months were examined. Venous blood samples taken from young patients were used to determine leukocyte blood composition considering the relative (%) and absolute number of blood cell counts. Hormone concentration was determined concurrently. CD-molecule expression by mononuclear cells was registered using flow cytofluorimeter. Plasma viral load in HIV-infected children was quantitatively detected with RT-PCR. Statistically significant lowering in the levels of free thyroxin, cortisol and progesterone was observed in children against a background of highly-active antiretroviral therapy as compared to those without HAART use. Correlation assay between the hormone level and the immunological parameters in children not receiving the antiretroviral preparations revealed marked positive correlations among the somatotropic hormone level and CD3+, CD4+ and CD8+ absolute numbers. Similar positive correlation with absolute T-subset number was found against free T4. The progesterone level also positively correlated with relative CD3+ and CD8+ numbers and showed negative correlation with absolute CD4+ amount. There is another positive correlation with relative T-subset number against the dehydroepiandrosterone level in the group of children without antiretroviral preparation therapy. As for HIV-infected group of children, against a background of highly-active antiretroviral therapy, the results of correlation assay between the hormone concentrations and cell parameters were found to significantly vary. There were observed positive correlations between the levels of cortisol and CD3+ (%), cortisol and CD8+ (%), estradiol and CD4/CD8, progesterone and absolute CD8+ number. As with children not receiving the antiretroviral preparations marked positive relation was revealed between the concentration of free thyroxin and absolute values of CD4+. Negative correlations were recorded between the estradiol level and the relative CD3+ numbers. Against a background of applying the antiretroviral preparations the correlation assay conducted between the viral RNA concentration (lg of copy number of mRNA/ml) and analyzed endocrinological parameters was found to have marked positive correlation with HIV concentration demonstrated by estradiol and testosterone. During the antiretroviral therapy, however, the negative correlation between the thyrotropin level and lg concentration of viral RNA was observed. Analytical results of correlation among the viral RNA concentration (lg copy number of mRNA/ml) and analyzed immunological parameters in this group of children evidence for specific ‘normalization’ due to highly-active antiretroviral therapy as the only positive correlation with virus concentration was detected for CD4+T subsets. Therefore, the alteration in endocrine system state in children born from HIV-infected mothers could be of great significance while monitoring the systemic regulation of the immunogenesis.

Age-Specific Reference Intervals for Thyroid-Stimulating Hormones and Free Thyroxine to Optimize Diagnosis of Thyroid Disease.

Background: Thyroid-stimulating hormone (TSH) and subsequent free thyroxine (FT4) concentrations outside the reference interval (RI) are used to diagnose thyroid diseases. Most laboratories do not provide age-specific RIs for TSH and FT4 beyond childhood, although TSH concentrations vary with age. Therefore, we aimed to establish TSH and FT4 age-specific RIs throughout life and aimed to determine whether using these RIs would result in reclassification of thyroid disease diagnoses in adults. Methods: This multicenter retrospective cross-sectional study used big data to determine indirect RIs for TSH and FT4. These RIs were determined by TMC and refineR-analysis, respectively, using four different immunoassay platforms (Roche, Abbott, Siemens, and Beckman Coulter). Retrospective data (2008-2022) from 13 Dutch laboratories for general practitioners and local hospitals were used. RIs were evaluated per manufacturer. Age groups were established from 2 to 20 years by 2-year categories and decade categories between 20 and 100 years. Results: We included totally 7.6 million TSH and 2.2 million FT4 requests. TSH upper reference limits (URLs) and FT4 lower reference limits were higher in early childhood and decreased toward adulthood. In adulthood, TSH URLs increased from 60 years in men, and from 50 years in women, while FT4 URLs increased from 70 years onward. Using adult age-specific RIs resulted in a decrease in diagnoses of subclinical and overt hypothyroidism in women above 50 and men above 60 years in our Roche dataset. Conclusion: This study stressed the known importance of using age-specific RIs for TSH and FT4 in children. This study also showed the clinical relevance of using age-specific RIs for TSH in adulthood to reduce diagnoses of subclinical hypothyroidism in older persons. Therefore, implementation of adult TSH age-specific RIs should be strongly considered. Data are less uniform regarding FT4 age-specific RIs and more research should be performed before implementing these in clinical practice.

105 Fetal hypothyroidism dysregulates local hepatic and renal renin-angiotensin systems in a temporal manner

Abstract The renin-angiotensin system (RAS) is an essential endocrine system with roles in electrolyte balance, blood volume, and blood pressure. While the canonical RAS exerts systemic vasoregulatory effects through steps involving hepatic, renal, and pulmonary-derived compounds, there is also evidence of localized, independently acting RAS in organs such as the liver and kidney. Further, modulations in RAS resulting from fetal hypothyroidism have previously been documented, although the temporal specificity of this endocrine interaction is not well-characterized. Thus, the objective of the current study was to examine the time-dependency of modulations in local hepatic and renal RAS in a porcine model of fetal hypothyroidism. To achieve this, pregnant gilts (n = 24) were divided evenly into either a control (CON) or methimazole (MMI) treatment group, with the MMI group receiving 5 mgּ kg-1ּ d-1 of oral MMI treatment and the CON group receiving an equivalent sham carrier. Each group was further divided into four timepoints (n = 3/treatment at each timepoint), with treatment beginning on d 34, 45, 55, or 65 of gestation. After 21 d of treatment, and at d 55, 66, 76, and 86, respectively, the gilts were humanely euthanized, blood samples taken from all fetuses (n = 340), and thyroid, liver (LVR), and kidney (KID) collected from a subset of four fetuses per litter (n = 96). Confirmation of fetal hypothyroidism in the MMI group was accomplished via histological assessment of the thyroid and measurement of circulating thyroxine (T4) concentrations. Each MMI-treated fetus (n = 96) subset showed evidence of goitrous thyroid histology, with the absence of healthy eosinophilic colloid indicating successful disruption of the fetal hypothalamic-pituitary-thyroid axis. T4 assays performed on a similar subset of n = 96 fetuses showed that MMI treatment significantly reduced T4 concentrations within each timepoint relative to CON (P &amp;lt; 0.001 at all timepoints). Following confirmation of hypothyroidism, RNA was extracted from the fetal LVR and KID samples to allow for gene expression analysis by qPCR. Ct values were normalized, fold changes calculated using the 2-∆∆Ct method, and differences within timepoint determined using a Wilcoxon signed-rank test. AGT, the precursor to all bioactive RAS peptides, was significantly downregulated in LVR at d 66 (P = 0.014) and 76 (P &amp;lt; 0.001). ACE was significantly upregulated at d 76 in both LVR (P = 0.037) and KID (P = 0.005). No significant changes were observed for ACE2 in either tissue, or for renal REN. Finally, AGTR1, the receptor that mediates RAS effects, was significantly downregulated at d 55 in KID (P &amp;lt; 0.001) and d 76 in LVR (P = 0.023), while also being upregulated at d 86 in LVR (P = 0.033). Collectively, these results show that fetal hypothyroidism modulates RAS function in a gestational age-dependent manner, which may alter fetal development and subsequent postnatal physiology.

Effect of Presence of Uni- or Bilateral Thyroid Adenoma on Recovery of Pituitary-Thyroid Axis and Creatinine Concentration in Radioiodine-Treated Cats.

Radioiodine therapy (RAIT) is the gold standard for treatment of hyperthyroidism in cats. The aim of this study was to evaluate the effect of the presence of uni- or bilateral thyroid adenoma on changes in total thyroxine (TT4), thyroid-stimulating hormone (TSH), and creatinine concentration over a period of 6 to 12 months following RAIT. Fifty-one hyperthyroid cats presented for RAIT between April 2021 and April 2022 were prospectively enrolled. Cats with an increased creatinine concentration (creatinine ≥ 140 µmol/L), renal morphology abnormalities, and suspected thyroid carcinoma were excluded. TT4, TSH, and creatinine were determined before and one week and one, three, six, and twelve months following RAIT. The effects of the re-examination timepoint following RAIT and the presence of uni- or bilateral thyroid adenoma based on technetium-99m scintigraphy on TT4, TSH, and creatinine were analysed by mixed effects modelling. Cats with bilateral adenoma had significantly higher TSH concentrations after RAIT compared to those with unilateral adenoma. TT4 concentration significantly decreased one week (p < 0.001) and again one month following RAIT (p < 0.001). TSH and creatinine concentration significantly increased one month post RAIT (both p < 0.001). As indicated by an increase in TSH concentration, the pituitary-thyroid axis needs a minimum of one month post RAIT to recover from hyperthyroidism-induced suppression, but hypothyroidism necessitating levothyroxine supplementation might not be diagnosed before 6 or even 12 months post RAIT. Although creatinine did not increase significantly after one month post RAIT in this cohort, an increased creatinine concentration was detected at later timepoints in individual cats.

Suppression of Hippocampal Neurogenesis and Oligodendrocyte Maturation Similar to Developmental Hypothyroidism by Maternal Exposure of Rats to Ammonium Perchlorate, a Gunpowder Raw Material and Known Environmental Contaminant.

The environmental contaminant perchlorate raises concern for hypothyroidism-related brain disorders in children. This study investigated the effects of developmental perchlorate exposure on hippocampal neurogenesis and oligodendrocyte (OL) development. Pregnant Sprague-Dawley rats were administered with ammonium perchlorate (AP) in drinking water at concentrations of 0 (control), 300, and 1000 ppm from gestation day 6 until weaning [postnatal day (PND) 21]. On PND 21, offspring displayed decreased serum triiodothyronine and thyroxine concentrations at 1000 ppm and thyroid follicular epithelial cell hyperplasia at ≥300 ppm (accompanying increased proliferation activity at 1000 ppm). Hippocampal neurogenesis indicated suppressed proliferation of neurogenic cells at ≥300 ppm, causing decreases in type-1 neural stem cells (NSCs) and type-2a neural progenitor cells. In addition, an increase of SST+ GABAergic interneurons and decreasing trend for ARC+ granule cells were observed at 1000 ppm. CNPase+ mature OLs were decreased in number in the dentate gyrus hilus at ≥300 ppm. At PND 77, thyroid changes had disappeared; however, the decrease of type-1 NSCs and increase of SST+ interneurons persisted, CCK+ interneurons were increased, and white matter tissue area was decreased at 1000 ppm. Obtained results suggest an induction of hypothyroidism causing suppressed hippocampal neurogenesis (targeting early neurogenic processes and decreased synaptic plasticity of granule cells involving ameliorative interneuron responses) and suppressed OL maturation during the weaning period. In adulthood, suppression of neurogenesis continued, and white matter hypoplasia was evident. Observed brain changes were similar to those caused by developmental hypothyroidism, suggesting that AP-induced developmental neurotoxicity was due to hypothyroidism.

Serum chemistry, thyroxine concentration, and blood cell morphology of wild, young Blackchin Guitarfish Glaucostegus cemiculus sampled on the eastern Mediterranean coastline.

The Blackchin Guitarfish Glaucostegus cemiculus is endemic to the Mediterranean Sea and is critically endangered, but relevant routine laboratory data are unavailable. Our objectives were to determine the packed cell volume (PCV), comprehensive serum chemistry analytes, and serum total thyroxine (sTT4) concentration; compare serum albumin and serum globulin concentrations as measured by two different methods; and describe the blood cell morphology of healthy, free-ranging Blackchin Guitarfish. Wild Blackchin Guitarfish were captured using a seine net. Blood samples for serum chemistry and hematological analyses were obtained and measured using routine laboratory methods. The fish were tagged and released. This study included 43 Blackchin Guitarfish (17 males and 26 females) that were younger than 6 months as estimated based on total length and body weight. The median PCV (n = 23) was 22% (minimum-maximum [min-max] = 15-25%). Median sTT4 (n = 10) measured by chemiluminescence immunoassay was 7.86 nmol/L (min-max = 7.52-9.57 nmol/L). The study included a comprehensive, 25-analyte serum chemistry analysis (e.g., serum iron and unbound and total iron-binding capacity) and a morphological description of all blood cells. Serum electrophoresis (SEP; n = 13) yielded a consistent serum albumin-migrating protein fraction and four globulin fractions. Serum electrophoretograms corroborating these results are presented. In Blackchin Guitarfish, the serum albumin-migrating fraction measured by SEP combined with serum total protein concentration yields a much higher albumin concentration compared to that measured by bromocresol green spectrophotometry. The true identity of this albumin-migrating fraction remains to be identified. The analytes' calculated 2.5-97.5% interpercentile intervals should be considered as reference intervals applying to Blackchin Guitarfish of similar age but should be applied cautiously to adult fish.

Effects of Acremonium terricola Culture on Lactation Performance, Immune Function, Antioxidant Capacity, and Intestinal Flora of Sows.

This study aimed to determine the effects of different doses of Acremonium terricola culture (ATC) on lactation performance, immune function, antioxidant capacity, and intestinal flora of sows. Forty-five Landrace sows (3-6 parity) were randomly assigned to the following three treatments from 85 days of gestation to 21 days after farrowing: a control diet (CON, basal diet), a low-dose Acremonium terricola culture diet (0.2% ATC, basal diet + 0.2% ATC), and a high-dose Acremonium terricola culture diet (0.4% ATC, basal diet + 0.4% ATC). Compared with the CON group, the supplementation of 0.2% ATC increased the average daily milk yield of sows by 4.98%, increased milk fat, total solids, and freezing point depression on day 1 postpartum (p < 0.05), increased serum concentration of Triiodothyronine, Thyroxin, and Estradiol on day 21 postpartum (p < 0.05). Compared with the CON group, the supplementation of 0.4% ATC increased the average daily milk yield of sows by 9.38% (p < 0.05). Furthermore, the supplementation of 0.2% ATC increased serum concentration of IgG, IgM, and IFN-γ, CD4 on day 1 postpartum (p < 0.05) and increased serum concentration of immunoglobulin A ( IgA), immunoglobulin G (IgG), immunoglobulin M ( IgM), complement 3 (C3), cluster of differentiation 4 (CD4), cluster of differentiation 8 (CD8), interferon-γ (IFN-γ) on day 21 postpartum (p < 0.05), while the supplementation of 0.4% ATC reduced serum concentration of IL-2 on day 21 postpartum (p < 0.05). Moreover, the supplementation of 0.4% ATC significantly increased serum concentration of catalase (CAT) (p < 0.05). Additionally, the supplementation of ATC affected the relative abundance of the intestinal flora at different taxonomic levels in sows and increased the abundance of beneficial bacteria such as in the norank_f__Eubacterium_coprostanoligenes group, Eubacterium_coprostanoligenes group, and Lachnospiraceae_XPB1014 group of sows, while reducing the abundance of harmful bacteria such as Phascolarctobacterium and Clostridium_sensu_stricto_1. These data revealed that the supplementation of ATC during late gestation and lactation can improve lactation performance, immune function, antioxidant capacity, and the gut microbiota. Compared with supplementation of 0.4% ATC, 0.2% ATC enhances the levels of thyroid-related hormones, specific antibodies, and cytokines in serum, promotes the diversity of beneficial gut microbiota, beneficial bacteria in the intestine, reduces the population of harmful bacteria, and thereby bolsters the immunity of sows. Hence, 0.2% ATC is deemed a more optimal concentration.

Iodine deficiency as an environmental risk factor for thyroid gland diseases in animals

Among non-infectious diseases in humans and animals, iodine deficiency pathology is a significant problem worldwide due to its high prevalence and broad spectrum of clinical signs and consequences. Increasing anthropogenic pressure on the natural environment has led to an ecological crisis. The situation is complicated in the biogeochemical zones of Ukraine, where insufficient or excessive content of mobile forms of microelements in soils and water sources determines the biological reaction of local flora and fauna. In animals, this is manifested by endemic diseases, including hypothyroidism. Mineral elements, including iodine, are a structural material in the body of animals; they participate in the processes of digestion and absorption in the digestive tract, synthesis, splitting, and excretion of metabolic products, creating the necessary conditions for the normal functioning of enzymes, hormones, vitamins, stabilize acidic-alkaline balance and osmotic pressure. Of all the organs of the endocrine system, the thyroid gland is the most closely related to the environment since its structure and function largely depend on the supply of iodine from the outside. The authors describe in detail the role of synergists of iodine (selenium, iron, copper, zinc, cobalt) and antagonists, the imbalance of trace elements, the influence of ionizing radiation, and the nature of feeding. It is substantiated that the action of environmental elements and anthropogenic factors determines the appearance and risk of developing thyroid pathology in cows. The article presents materials from a complex study of the clinical course of iodine deficiency, as well as morphological and biochemical parameters of the blood of cows. The object of research is clinically healthy and sick animals – cattle. Diagnosis of thyroid pathology was carried out with the help of clinical and laboratory tests. The clinical examination of cows was carried out according to the generally accepted scheme, taking into account the results of the general condition and studies of individual organs and systems. The research was conducted in three districts of the Zhytomyr region (Korostenskyi, Narodytskyi, and Popilnianskyi). During the external examination of the animals, swelling in the intermaxillary space (Myxedema) was observed, which was found only in 5 out of 90 dairy cows (5.6 %), mainly from Narodytsky district (8.9 %), compared to 2.2 % in Korosten district. It was observed that goiter was established in only three cows out of 90 (3.35%); all were in Narodytsky district (6.7 %). Enophthalmos was detected in 24 out of 90 dairy cows (26.7 %), including 16 out of 45 cows (35.4 %) in the Narodytsky District, while this symptom was not detected in the Popilnya District dairy cows. It was established that the content of thyroxine in dairy cows of Narodytskyi and Korostensky districts ranged from 2.2 to 4.25 μg/100 ml (28.3–54.7 nmol/l), respectively, and was on average 3.4 ± 0.21 μg/100 ml (43.8 ± 2.70 nmol/l, in cows from the conditionally clean territory (Popelnyan district) – 5.3 ± 0.65 nmol/l.

Effects of GH L127V and TG5 C422T polymorphisms on the hormonal profile, slaughter traits, and meat quality of Hereford bulls.

The creation of objective methods for the evaluation and improvement of quantitative and qualitative indicators of meat productivity in farm animals should be based on a comprehensive analysis of the genetic, physiological, and biochemical parameters of the animal. This study aimed to investigate the effects of growth hormone (GH) and thyroglobulin (TG5) gene polymorphisms on the hormonal status, slaughter traits, and chemical, amino acid, and fatty acid composition of meat in Hereford bulls. Hereford bulls (n = 9) were reared under the same feeding and housing conditions until the age of 21 months, after which they were slaughtered. Polymerase chain reaction-restriction fragment length polymorphism was performed for genotyping GH L127V and TG5 C422T polymorphisms. The experimental animals were evaluated to determine slaughter traits (including pre-slaughter weight, carcass, and internal fat weight and yield), chemical, fatty acid, and amino acid composition of ground beef, and hormonal status using serum concentrations of GH, triiodothyronine, and thyroxine. Animals with the valine homozygous (VV) genotype of GH had the maximum serum GH level of 9.33 mIU/mL (p = 0.10) higher than leucine homozygous (LL) genotype carriers. Individuals with the LL genotype outperformed V-allele carriers in serum thyroxine (T4) concentration by 21.3-30.5 nmol/L (16.15%-24.86%; p < 0.01-0.05). Genetic differentiation induced by TG5 C422T polymorphism was determined to a lesser extent by the hormonal status of the Hereford animals. The V-allele was associated with increased carcass weight, with VV homozygotes significantly outperforming LL individuals by 45.0 kg (13.61%; p < 0.05). The T allele at the TG5 gene polymorphism was associated with more intense lipogenesis and less protein synthesis in muscle tissue and these effects were enhanced in the homozygous state. Young animals with the TT variant of the TG5 gene exhibited a significantly superior polyunsaturated fatty acid/saturated fatty acid ratio of 0.012 units (p < 0.01). Carriers of the LL genotype were characterized by minimum amino acid content in muscle tissue. Heterozygous bulls exceeded LL homozygotes in the sum of essential amino acids by 3.09% (p = 0.10) and non-essential amino acids by 1.9% (p < 0.05). The development of breeding programs for the Hereford breed should be carried out considering genetic features that determine the formation of economic traits in animals. Analysis of polymorphisms in the TG5 gene is a promising method for the early diagnosis of the fatty acid composition of beef. Identification of polymorphisms in the GH gene allows the prediction of higher productivity potential and amino acid composition of meat. The different effects of the GH and TG5 genes on the development of various economic traits allowed us to determine further vectors for scientific research on their complex associations in Hereford cattle, which will be useful for planning effective breeding schemes.

Association of maternal mild hypothyroidism in the first and third trimesters with obstetric and perinatal outcomes: a prospective cohort study

BackgroundMild hypothyroidism, including subclinical hypothyroidism (SCH) and isolated maternal hypothyroxinemia (IMH), is fairly common in pregnant women, but its impact on pregnancy outcomes is less clear, especially mild hypothyroidism in late pregnancy. ObjectiveTo evaluate the impact of SCH and IMH in the first and third trimesters, respectively, on obstetric and perinatal outcomes. Study DesignThis large prospective study was conducted at the International Peace Maternity and Child Health Hospital (IPMCH) in Shanghai. 52,027 pregnant women who underwent the first-trimester antenatal screening at IPMCH were consecutively enrolled from January 2013 to December 2016. To evaluate the impact of maternal SCH and IMH in the first trimester on pregnancy outcomes, participants were divided into three groups according to thyroid function in the first trimester: first-trimester euthyroidism group (n= 33,130), first-trimester SCH group (n= 884), and first-trimester IMH group (n= 846). Then, to evaluate the impact of maternal SCH and IMH in the third trimester on pregnancy outcomes, the first-trimester euthyroidism group was subdivided into three groups according to thyroid function in the third trimester: third-trimester euthyroidism group (n= 30,776), third-trimester SCH group (n= 562), and third-trimester IMH group (n= 578). Obstetric and perinatal outcomes, including preterm birth (PTB), preeclampsia, gestational hypertension, gestational diabetes mellitus (GDM), large for gestational age (LGA), small for gestational age, macrosomia, cesarean section, and fetal demise were measured and compared between those in either SCH/IMH group and euthyroid group. Binary logistic regression was used to assess the association of SCH or IMH with these outcomes. Results34,860 pregnant women who had first (weeks 8–14) and third trimester (weeks 30–35) thyrotropin and free thyroxine concentrations available were included in the final analysis. Maternal SCH in the first trimester was linked to a lower risk of GDM (aOR 0.64, 95% CI 0.50–0.82) compared with the euthyroid group. However, third-trimester SCH is associated with heightened rates of PTB (aOR 1.56, 95%CI 1.10–2.20), preeclampsia (aOR 2.23, 95%CI 1.44–3.45), and fetal demise (aOR 7.00, 95%CI 2.07–23.66) compared with the euthyroid group. IMH in the first trimester increased risks of preeclampsia (aOR 2.14, 95% CI 1.53–3.02), GDM (aOR 1.45, 95%CI 1.21–1.73), LGA (aOR 1.64, 95%CI 1.41–1.91), macrosomia (aOR 1.85, 95%CI 1.49–2.31) and cesarean section (aOR 1.35, 95%CI 1.06–1.74), while IMH in the third trimester increased risks of preeclampsia (aOR 2.85, 95%CI 1.97–4.12), LGA (aOR 1.49, 95%CI 1.23–1.81) and macrosomia (aOR 1.60, 95%CI 1.20–2.13) compared with the euthyroid group. ConclusionThis study indicates that while first-trimester SCH did not elevate the risk for adverse pregnancy outcomes, third-trimester SCH was linked to several adverse pregnancy outcomes. IMH in the first and third trimesters was associated with adverse pregnancy outcomes, yet the impact varied by trimester. These results suggest the timing of mild hypothyroidism in pregnancy may be pivotal in determining its effects on adverse pregnancy outcomes and underscore the importance of trimester-specific evaluations of thyroid function.

Ostruthin, a TWIK-Related Potassium Channel Agonist, Increases the Body Temperature in Ovariectomized Rats With or Without Progesterone Administration.

The TWIK-related potassium (TREK) channel subfamily, including TREK1 and TREK2, is a novel cold receptor. Ostruthin, a TREK1 and TREK2 agonist, is a component found in the plant Paramignya trimera and is traditionally used as an anticancer medicine in Vietnam, with its stems and roots treating various ailments. The female hormone progesterone (P4) influences body temperature in women; however, the effect of P4 on thermoregulation via TREK has not been examined. This study aims to investigate the effects of P4 on thermoregulatory responses in ostruthin-administered ovariectomized rats, which are animal models of human menopause. Wistar rats were ovariectomized and implanted with silastic tubes with or without P4 (P4(+) and P4(-) groups). The TREK agonist or vehicle was injected intraperitoneally. Body temperature, locomotor activity, tail skin temperature, and thermoregulatory behavior (assessed by tail-hiding behavior) were continuously measured. Plasma concentrations of catecholamines, triiodothyronine, and thyroxine were also measured. In both the P4(+) and P4(-) groups, the change in body temperature was greater among the rats administered the TREK agonist compared to the vehicle. No significant differences were observed between the groups in locomotor activity, tail skin temperature, or tail-hiding behavior. The dopamine concentration in the P4(+) group was lower than that in the P4(-) group. Ostruthin, the TREK agonist, increases body temperature in ovariectomized rats; however, P4 may not affect these responses in ovariectomized rats.