Circadian Synchronization of Feeding Attenuates Rats' Food Restriction-Induced Anxiety and Amygdalar Thyrotropin-Releasing Hormone Downregulation.

Anxiety is a common comorbidity of obesity, resulting from prescribing long-term caloric restriction diets (CRDs); patients with a reduced food intake lose weight but present anxious behaviors, poor treatment adherence, and weight regain in the subsequent 5 years. Intermittent fasting (IF) restricts feeding time to 8 h during the activity phase, reducing patients' weight even with no caloric restriction; it is unknown whether an IF regime with ad libitum feeding avoids stress and anxiety development. We compared the corticosterone blood concentration between male Wistar rats fed ad libitum or calorie-restricted with all-day or IF food access after 4 weeks, along with their anxiety parameters when performing the elevated plus maze (EPM). As the amygdalar thyrotropin-releasing hormone (TRH) is believed to have anxiolytic properties, we evaluated its expression changes in association with anxiety levels. The groups formed were the following: a control which was offered food ad libitum (C-adlib) or 30% of C-adlib's energy requirements (C-CRD) all day, and IF groups provided food ad libitum (IF-adlib) or 30% of C-adlib's requirements (IF-CRD) with access from 9:00 to 17:00 h. On day 28, the rats performed the EPM and, after 30 min, were decapitated to analyze their amygdalar TRH mRNA expression by in situ hybridization and corticosterone serum levels. Interestingly, circadian feeding synchronization reduced the body weight, food intake, and animal anxiety levels in both IF groups, with ad libitum (IF-adlib) or restricted (IF-CRD) food access. The anxiety levels of the experimental groups resulted to be negatively associated with TRH expression, which supported its anxiolytic role. Therefore, the low anxiety levels induced by synchronizing feeding with the activity phase would help patients who are dieting to improve their diet therapy adherence.

Thyrotropin-Releasing Hormone and Food Intake in Mammals: An Update.

Thyrotropin-releasing hormone (TRH; pGlu-His-Pro-NH2) is an intercellular signal produced mainly by neurons. Among the multiple pharmacological effects of TRH, that on food intake is not well understood. We review studies demonstrating that peripheral injection of TRH generally produces a transient anorexic effect, discuss the pathways that might initiate this effect, and explain its short half-life. In addition, central administration of TRH can produce anorexic or orexigenic effects, depending on the site of injection, that are likely due to interaction with TRH receptor 1. Anorexic effects are most notable when TRH is injected into the hypothalamus and the nucleus accumbens, while the orexigenic effect has only been detected by injection into the brain stem. Functional evidence points to TRH neurons that are prime candidate vectors for TRH action on food intake. These include the caudal raphe nuclei projecting to the dorsal motor nucleus of the vagus, and possibly TRH neurons from the tuberal lateral hypothalamus projecting to the tuberomammillary nuclei. For other TRH neurons, the anatomical or physiological context and impact of TRH in each synaptic domain are still poorly understood. The manipulation of TRH expression in well-defined neuron types will facilitate the discovery of its role in food intake control in each anatomical scene.

The diagnosis and prevalence of hypoprolactinemia in patients with panhypopituitarism and the effects on depression and sexual functions.

PURPOSE: We aimed to investigate the prevalence and the diagnostic criteria of hypoprolactinemia in patients with panhypopituitarism and the effects of hypoprolactinemia on depression and sexual functions. MATERIALS AND METHODS: Forty-eight patients with panhypopituitarism and 20 healthy volunteers were included. Basal hormone levels were measured and a TRH stimulation test was performed. For the evaluation of sexual functions, questionnaries of Female Sexual Functional Index (FSFI) for females and International Erectile Functional Index for males were performed to the subjects. Depressive symptoms were evaluated by Beck Depression Envontory score (BDI-II). RESULTS: The peak PRL response to TRH stimulation test at 5th percentile in the control group was 18.6 ng/ml in males and 41.6 ng/ml in females and accepted as the cut-offs for sufficient response of PRL. Prolactin was insufficient in 42(87.5%) patients. A basal PRL level of ≤ 5.7 ng/ml in males and 7.11 ng/ml in females was 100% specific in predicting an inadequate response to TRH stimulation test with 80% and 70% sensitivity respectively. A basal PRL level of ≥ 8.5 ng/dl in males was 100% specific and 76% sensitive, and in females a level of ≥ 15.2 ng/dl was 96% specific and 66% sensitive in predicting an adequate response to TRH. PRL deficient patients with panhypopituitarism had higher depression scores compared to the controls, lower sexual function scores in males. CONCLUSION: PRL deficiency is prevalent among individuals with panhypopituitarism, with the potential to result in elevated depression scores in both sexes and impaired sexual functions in males. A basal PRL level seems to be sufficient for the diagnosis of hypoprolactinemia in routine clinical practice.

Novel Leptin-Cardiac TRH pathway responsible for the cardiac alterations in the Hyperleptinemic obesity.

The association between hypertension and obesity-induced cardiac damage is usually accepted. However, no studies have been focused on cardiac alterations in obesity, independently of blood pressure increase. It is well known that Cardiac TRH induces Left Ventricular Hypertrophy (LVH) and fibrosis, and its inhibition prevents the development of hypertrophy. Also, it has been described that the adiponectin leptin induces TRH expression. Thus, we hypothesized that in obesity, the increase in TRH induced by hyperleptinemia is responsible for LVH, until now mostly attributed to pressure load. We studied obese Agouti mice suffering from hypertension with hyperleptinemia and found a significant LVH development with increased TRH gene expression. Consequently, we found higher fibrotic (collagens and TGF-ß) and hypertrophic markers (BNP and ß-MHC) expression vs lean black controls. As pressure could explain these results, we treated obese mice with diuretic (hydrochlorothiazide 20 mg/kg/day) since weaning. Diuretic treatment was successful as the diuretic group was normotensive in contrast to control obese mice. Nevertheless, both groups showed LVH development, higher cardiac precursor TRH gene and peptide expressions and elevated fibrotic and hypertrophic markers expression, pointing out that obesity-induced LVH is not due to hypertension. In addition, we performed Cardiac TRH inhibition by specific siRNA injection compared to control siRNA treatment and evaluated cardiac damage. As expected, expressions and protein increase in hypertrophic and fibrotic markers observed in the AG mouse with the native cTRH system were not seen in the AG mouse with the cTRH silencing. Indeed, the AG + TRH-siRNA group showed hypertrophic markers expression and fibrosis measurements similar to the lean BL mice. On the whole, these results point out that the novel Leptin-Cardiac TRH pathway is responsible for the cardiac alterations present in hyperleptinemic obesity, independent of blood pressure, and cTRH long-term silencing since early stages totally prevent LVH development and cardiac fibrosis.

Characterization of thyrotropin-releasing hormone producing neurons in sea urchin, from larva to juvenile.

Most sea urchin species are indirect developers, going through a larval stage called pluteus. The pluteus possesses its own nervous system, consisting mainly of the apical organ neurons (controlling metamorphosis and settlement) and ciliary band neurons (controlling swimming behavior and food collection). Additional neurons are located in various areas of the gut. In recent years, the molecular complexity of this apparently "simple" nervous system has become apparent, with at least 12 neuronal populations identified through scRNA-sequencing in the species Strongylocentrotus purpuratus. Among these, there is a cluster of neurosecretory cells that produce a thyrotropin-releasing hormone-type neuropeptide (TRHergic) and that are also photosensory (expressing a Go-Opsin). However, much less is known about the organization of the nervous system in other sea urchin species. The aim of this work was to thoroughly characterize the localization of the TRHergic cells from early pluteus to juvenile stages in the Mediterranean sea urchin species Paracentrotus lividus combining immunostaining and whole mount in situ hybridization. We also compared the localization of TRHergic cells in early plutei of two other sea urchin species, Arbacia lixula and Heliocidaris tuberculata. This work provides new information on the anatomy and development of the nervous system in sea urchins. Moreover, by comparing the molecular signature of the TRHergic cells in P. lividus and S. purpuratus, we have obtained new insights how TRH-type neuropeptide signaling evolved in relatively closely related species.

Valproate decreases transgenerationally blood pressure by affecting thyrotropin-releasing hormone promoter DNA methylation and gene expression in spontaneously hypertensive rat.

Central TRH, a neuropeptide, is involved in cardiovascular regulation. We demonstrated that the overexpression of diencephalic TRH (dTRH) in SHR rats can be prevented by antisense treatment, normalizing blood pressure (BP). Valproate (VPA) is an inhibitor of histone deacetylases (HDAC) which modulates gene expression through epigenetic modifications such as DNA methylation. AIMS: Study the role of HDAC inhibition in the regulation of dTRH gene expression and its effect on the pathogenesis of hypertension. MAIN METHODS: We treated 7-weeks-old male and female SHR and WKY rats with VPA for 10 weeks and evaluated BP, dTRH mRNA and methylation gene status. KEY FINDINGS: VPA attenuated the elevated BP and dTRH mRNA expression characteristic of SHR. Indeed, we found a significant 62% reduction in dTRH mRNA expression in the SHR + VPA group compared to control SHR. The decrease TRH mRNA expression induced by VPA was confirmed "in vitro" in a primary neuron culture using trichostatin A. With methylation specific PCR we demonstrated a significant increase in TRH promoter DNA methylation level in SHR + VPA group compared to control SHR. After 2 weeks of treatment interruption, rats were mated. Although they did not receive any treatment, the offspring born from VPA-treated SHR parents showed similar changes in BP, dTRH expression and methylation status, implying a transgenerational inheritance. Our findings suggest that dTRH modulation by epigenetics mechanism affects BP and could be inherited by the next generation in SHR rats.

Cobertura de MRS e indicación de terapia hormonal en Pedro Aguirre Cerda, septiembre de 2019

Introducción: El envejecimiento de la población en todo el mundo es un fenómeno progresivo y Chile no se queda atrás frente a esto. Actualmente existe un subprograma de climaterio mujeres entre los 45 a 64 años, que presenta diversas acciones y propósitos. Objetivo: Describir la cobertura de la aplicación de la Menopause Rating Scale (MRS) e indicación de terapia de reemplazo hormonal en mujeres inscritas en los CESFAM de la comuna de Pedro Aguirre Cerda. Método: Descriptivo transversal. Resultados: La cobertura de aplicación de MRS en mujeres entre 45-64 años fue de un 62,6%. Un 34,3% de mujeres presentaron un puntaje MRS alterado, indicándose terapia hormonal en un 37,8% de los casos, en las indicaciones un 21,8% eran usuarias candidatas acorde a criterios médicos y un 78,2% no lo eran. Conclusiones: Se debe aumentar la cobertura de MRS y recursos para exámenes de laboratorio, de imágenes y capacitaciones, esto para mejorar la entrega de las prestaciones en el subprograma climaterio.

Introduction: The aging of the population worldwide is a progressive phenomenon and Chile is not lagging behind in this. Currently, there is a climacteric subprogram for women between 45 and 64 years of age, which has various actions and purposes. Objective: To describe the coverage of the application of the Menopause Rating Scale (MRS) and indication of hormone replacement therapy in women enrolled in the CESFAM of the commune of Pedro Aguirre Cerda. Method: Cross-sectional descriptive study. Results: The coverage of the MRS application in women between 45-64 years old was 62.6%. A 34.3% of women presented an altered MRS score, indicating hormone therapy in 37.8% of the cases, 21.8% of the indications were candidates according to medical criteria and 78.2% were not. Conclusions: There is a lack of labs and images tests in the climacteric controls, resulting in a mayor number of women no candidates to the hormonal therapy according to medical criteria.

Analyses of mRNA Expression Levels of Pituitary Hormones, Their Hypothalamic Regulating Factors, and Receptors Involved in Metamorphosis with Special Reference to the Summer and Winter Seasons.

Bullfrog (Rana catesbeiana) larvae inhabiting the main island of Japan overwinter as preclimax animals, whereas the larvae that reached climax in summer complete metamorphosis. We analyzed the mRNA expression levels of the adenohypophyseal hormones, hypothalamic hormones, and their receptors that are involved in controlling metamorphosis in tadpoles at various developmental stages available in summer and winter in order to understand the hormonal mechanism regulating metamorphosis progression. Corticotropin-releasing factor (CRF) and thyrotropin ß-subunit (TSHß) mRNA expression was enhanced as they reached the climax stage in metamorphosing summer tadpoles, although type 2 CRF receptor (CRFR2) mRNA levels demonstrated a tendency of elevation, indicating the activation of the hypothalamo-hypophyseal axis for stimulating the release of thyroid hormone in summer. Arginine vasotocin (AVT) mRNA levels were elevated as metamorphosis progressed, but mRNA expression levels were not synchronized with those of proopiomelanocortin (POMC) and V1b-type AVT receptor (V1bR). The elevation of mRNA levels of prolactin (PRL) 1A and type 3 thyrotropin-releasing hormone receptor (TRHR3), but not of thyrotropin-releasing hormone (TRH) precursor mRNA levels, was noted in climactic tadpoles, indicating that PRL mRNA levels are not simply dependent on the expression levels of TRH precursor mRNA. In the preclimactic larvae captured in winter, which are in metamorphic stasis, mRNA levels of pituitary hormones, hypothalamic factors, and their receptors remained low or at levels similar to those of the larvae captured in summer. These results indicate the relationship between the mRNA expression of metamorphosis-related factors and the seasonal progression/stasis of metamorphosis.

Novel DNA methylation biomarkers for early diagnosis of oral tongue squamous cell carcinoma (OTSCC).

Oral tongue squamous cell carcinoma (OTSCC) is the most common malignancy type among males across the world. However, analysis of molecular markers could be useful in detecting the early-stage OTSCC, which would allow optimal clinical treatments and prolong the survival rate of patients consequently. The study has the objective of detecting the role of salivary biomarkers based on gene promoter hypermethylation. Sample data from 45 OTSCC and normal groups were analyzed to exhibit the methylation levels of salivary biomarkers (TRH, FHIT, MGMT, p16, and RASSF1A). The specificity and sensitivity analysis of methylation biomarkers was conducted in addition to the receiver operating characteristic (ROC) curve for both early-stage and advanced OTSCC stages. Quantitative data findings showed the perfect sensitivity and specificity for TRH, MGMT, p16, and RASSF1A with 100%, and > 90%, respectively. In addition, the results indicated an inefficient area under curves (> 0.7) for these biomarkers to detect the OTSCC. There were no significant differences observed between TRH and FHIT and p16 and MGMT based on the Wilcoxon signed-rank test. The methylation statuses of genes TRH, RASSF1A, p16, and MGMT might become utilized as predictive biomarkers for clinical application in early diagnosis of OTSCC and noninvasive oral cancer screening.

Intracerebroventricular administration of TRH Agonist, RX-77368 alleviates visceral pain induced by colorectal distension in rats.

Thyrotropin-releasing hormone (TRH) acts centrally to exert pleiotropic actions independently from its endocrine function, including antinociceptive effects against somatic pain in rodents. Whether exogenous or endogenous activation of TRH signaling in the brain modulates visceral pain is unknown. Adult male Sprague-Dawley rats received an intracerebroventricular (ICV) injection of the stable TRH analog, RX-77368 (10, 30 and 100 ng/rat) or saline (5 µl) or were semi-restrained and exposed to cold (4°C) for 45 min. The visceromotor response (VMR) to graded phasic colorectal distensions (CRD) was monitored using non-invasive intracolonic pressure manometry. Naloxone (1 mg/kg) was injected subcutaneously 10 min before ICV RX-77368 or saline. Fecal pellet output was monitored for 1 h after ICV injection. RX-77368 ICV (10, 30 and 100 ng/rat) reduced significantly the VMR by 56.7%, 67.1% and 81.1% at 40 mmHg and by 30.3%, 58.9% and 87.4% at 60 mmHg respectively vs ICV saline. Naloxone reduced RX-77368 (30 and 100 ng, ICV) analgesic response by 51% and 28% at 40 mmHg and by 30% and 33% at 60 mmHg respectively, but had no effect per se. The visceral analgesia was mimicked by the acute exposure to cold. At the doses of 30 and 100 ng, ICV RX-77368 induced defecation within 30 min. These data established the antinociceptive action of RX-77368 injected ICV in a model of visceral pain induced by colonic distension through recruitment of both opioid and non-opioid dependent mechanisms.

Quetiapine and Valproic Acid-induced Central Hypothyroidism in a Patient with Autism Spectrum Disorder and Intractable Epilepsy: A Case Report.

OBJECTIVES: Patients with an autism spectrum disorder (ASD) are prone to disruptive behaviors and aggression. Atypical antipsychotics are used to treat these difficult ASD conditions. Several psychotropic drugs have been linked to hypothyroidism. The clinical manifestation of hypothyroidism is indistinguishable from that of an antipsychotic's general adverse effect, which can lead to a delayed or missed diagnosis. Conversely, thyroid dysfunction can exhibit an impact on mood, anxiety, depression, and cognitive functions. CASE STUDY: We present a case of central hypothyroidism caused by long-term use of valproic acid (VPA) and adding quetiapine to risperidone. The current case had a history of hyperprolactinemia and subclinical hypothyroidism caused by risperidone and VPA, respectively, before the administration of quetiapine. CONCLUSION: This is the first report of quetiapine-induced central hypothyroidism in a patient with ASD, as determined by a thyrotropin-releasing hormone (TRH) loading test. TRH loading test may be useful in elucidating the pathogenesis of hypothyroidism in patients receiving quetiapine and VPA. Thyroid function monitoring in patients taking quetiapine and VPA may provide an opportunity to begin replacement therapy.

Development of Multienzyme Isothermal Rapid Amplification (MIRA) Combined with Lateral-Flow Dipstick (LFD) Assay to Detect Species-Specific tlh and Pathogenic trh and tdh Genes of Vibrio parahaemolyticus.

Vibrio parahaemolyticus causes severe gastroenteritis in humans after consuming contaminated raw or undercooked seafood. A species-specific marker, the thermolabile hemolysin (tlh) gene, and two pathogenic markers, thermostable-related hemolysin (trh) and thermostable-direct hemolysin (tdh) genes, have been used to identify V. parahaemolyticus and determine its pathogenicity using both PCR and qPCR assays. To enable testing in field conditions with limited resources, this study aimed to develop a simple and rapid method to detect the species-specific (tlh) and pathogenic (trh and tdh) genes of V. parahaemolyticus using multienzyme isothermal rapid amplification (MIRA) combined with a lateral-flow dipstick (LFD). The amplification of the tlh, trh, and tdh genes could be completed within 20 min at temperatures ranging from 30 to 45 °C (p < 0.05). The test yielded positive results for V. parahaemolyticus but produced negative results for nine Vibrio species and eighteen foodborne pathogenic bacterial species. MIRA-LFD could detect 10 fg of DNA and 2 colony-forming units (CFU) of V. parahaemolyticus per reaction, demonstrating a sensitivity level comparable to that of qPCR, which can detect 10 fg of DNA and 2 CFU per reaction. Both MIRA-LFD and qPCR detected seven tlh-positive results from thirty-six oyster samples, whereas one positive result was obtained using the PCR assay. No positive results for the trh and tdh genes were obtained from any oyster samples using MIRA-LFD, PCR, and qPCR. This study suggests that MIRA-LFD is a simple and rapid method to detect species-specific and pathogenic genes of V. parahaemolyticus with high sensitivity.

Total thyroxine and thyroid-stimulating hormone responses of healthy cats to different doses of thyrotropin-releasing hormone.

Thyrotropin-releasing hormone (TRH) stimulation can be used as a test of thyroid function and pituitary thyrotropin (thyroid-stimulating hormone, TSH) reserve, but optimal stimulation testing protocols in cats are unreported. We randomly divided 6 healthy young adult cats into 3 groups of 2 and administered 3 different intravenous doses of TRH (0.01, 0.05, 0.1 mg/kg) at weekly intervals in our crossover study. Serum TSH and thyroxine (T4) concentrations were measured using chemiluminescent immunoassay before, and at 30 and 60 min after, TRH administration. All cats were monitored for 4 h post-TRH administration for side effects. All 3 TRH doses induced significant TSH (0.01 mg/kg, p = 0.001; 0.05 mg/kg, p = 0.002; 0.1 mg/kg, p = 0.006) and total T4 (0.01 mg/kg, p = 0.008; 0.05 mg/kg, p = 0.006; 0.1 mg/kg, p = 0.001) responses. Lower TRH doses (0.01 and 0.05 mg/kg) caused fewer side effects (1 of 6 cats) than did the highest dose (3 of 6 cats), and may be safer in cats than the previously reported higher dose (0.1 mg/kg) of TRH. Our results do not support the use of maropitant to prevent side effects of a TRH stimulation test in cats.

GLP-1 Receptor Signaling Has Different Effects on the Perikarya and Axons of the Hypophysiotropic Thyrotropin-Releasing Hormone Synthesizing Neurons in Male Mice.

Background: Glucagon-like peptide 1 (GLP-1) is involved in the regulation of energy and glucose homeostasis. As GLP-1 has similar effects on the energy homeostasis as the hypophysiotropic thyrotropin-releasing hormone (TRH) neurons that regulate the hypothalamic-pituitary-thyroid (HPT) axis, we raised the possibility that the TRH neurons are involved in the mediation of the effects of GLP-1. Therefore, the relationship and interaction of the GLP-1 system and the TRH neurons of the hypothalamic paraventricular nucleus (PVN) were studied. Methods: To examine the anatomical and functional relationship of TRH neurons and the GLP-1 system in the PVN, immunocytochemistry, in situ hybridization, in vitro patch-clamp electrophysiology, metabolic phenotyping, and explant experiments were performed. Results: Our data demonstrate that the TRH neurons of the PVN are innervated by GLP-1 producing neurons and express the GLP-1 receptor (GLP-1R). However, not only do the GLP-1-innervated TRH neurons express GLP-1R but the receptor is also present in the axons of the hypophysiotropic TRH neurons in the blood-brain barrier free median eminence (ME) suggesting that peripherally derived GLP-1 may also influence the TRH neurons. In vitro, GLP-1 increased the firing rate of TRH neurons and depolarized them. In addition, GLP-1 directly stimulated the GABAergic input of a population of TRH neurons. Furthermore, GLP-1 inhibited the release of TRH from the hypophysiotropic axons in the ME. In vivo, peripheral GLP-1R agonist administration markedly inhibited the food intake and the energy expenditure, but had no effect on the TRH expression in the PVN and resulted in lower circulating free T4 levels. Conclusions: Our results indicate that GLP-1R activation has a direct stimulatory effect on TRH neurons in the PVN, but the activation of GLP-1R may also inhibit TRH neurons by facilitating their inhibitory inputs or by inhibiting the axon terminals of these cells in the ME. The innervation of TRH neurons by GLP-1 neurons suggests that TRH neurons might be influenced by both circulating GLP-1 and by GLP-1 neurons of the nucleus tractus solitarii. The lack of GLP-1R agonist-induced regulation of TRH neurons in vivo suggests that the HPT axis does not mediate the GLP-1R agonist-induced weight loss.

Influence of feeding and other factors on adrenocorticotropin concentration and thyrotropin-releasing hormone stimulation test in horses and ponies.

BACKGROUND: The basal (bACTH) and post-thyrotropin-releasing hormone stimulation concentration of adrenocorticotropin (pACTH) are recommended for diagnosis of pituitary pars intermedia dysfunction (PPID). Many factors influence bACTH (e.g., disease, age, month) and some affect the results only in autumn (e.g., breed, colour, sex). There are discrepancies about the impact of feeding on b/pACTH. OBJECTIVES: To determine whether feeding, month, age, breed, colour, sex and body condition score affect b/pACTH. STUDY DESIGN: Prospective crossover. METHODS: Sixty-one animals were divided into groups: healthy, PPID, treated-PPID. The b/pACTH was measured three times (1 mg protirelin; blood collection after 10 min; mid-November to mid-July) after different feedings: fasting, hay, hay + grain. Friedman's test was applied to evaluate the influence of feeding on b/pACTH and linear mixed model to evaluate impact of further factors. RESULTS: The b/pACTH was not significantly affected by feeding (p = 0.7/0.5). The bACTH was lowest in healthy (29.3 pg/mL, CI 9-49.5 pg/mL) and highest in PPID-group (58.9 pg/mL, CI 39.7-78.1 pg/mL). The pACTH was significantly lower in healthy (396.7 pg/mL, CI 283.2-510.1 pg/mL) compared to PPID (588.4 pg/mL, CI 480.7-696.2 pg/mL) and treated-PPID group (683.1 pg/mL, CI 585.9-780.4 pg/mL), highest in July (881.2 pg/mL, CI 626.3-1136.3 pg/mL) and higher in grey (723.5 pg/mL, CI 577.5-869.4 pg/mL) than other colours (338.7 pg/mL, CI 324.8-452.5 pg/mL). The size of effect for those variables was >0.5. MAIN LIMITATIONS: Small number of animals, subsequent bACTH measurements were significantly lower in each horse. CONCLUSIONS: There was no evidence that feeding influences the b/pACTH. There was evidence that pergolide affects the bACTH but it had little effect on pACTH. Further investigation of the impact of month and coat colour on b/pACTH is warranted to better interpret the results.

BEVA primary care clinical guidelines: Diagnosis and management of equine pituitary pars intermedia dysfunction.

BACKGROUND: Pituitary pars intermedia dysfunction (PPID) is a prevalent, age-related chronic disorder in equids. Diagnosis of PPID can be challenging because of its broad spectrum of clinical presentations and disparate published diagnostic criteria, and there are limited available treatment options. OBJECTIVES: To develop evidence-based primary care guidelines for the diagnosis and treatment of equine PPID based on the available literature. STUDY DESIGN: Evidence-based clinical guideline using the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) framework. METHODS: Research questions were proposed by a panel of veterinarians and developed into PICO or another structured format. VetSRev and Veterinary Evidence were searched for evidence summaries, and systematic searches of the NCBI PubMed and CAB Direct databases were conducted using keyword searches in July 2022 and updated in January 2023. The evidence was evaluated using the GRADE framework. RESULTS AND RECOMMENDATIONS: The research questions were categorised into four areas: (A) Case selection for diagnostic testing, pre-test probability and diagnostic test accuracy, (B) interpretation of test results, (C) pharmacological treatments and other treatment/management options and (D) monitoring treated cases. Relevant veterinary publications were identified and assessed using the GRADE criteria. The results were developed into recommendations: (A) Case selection for diagnostic testing and diagnostic test accuracy: (i) The prevalence of PPID in equids aged ≥15 years is between 21% and 27%; (ii) hypertrichosis or delayed/incomplete hair coat shedding provides a high index of clinical suspicion for PPID; (iii) the combination of clinical signs and age informs the index of clinical suspicion prior to diagnostic testing; (iv) estimated pre-test probability of PPID should be considered in interpretation of diagnostic test results; (v) pre-test probability of PPID is low in equids aged <10 years; (vi) both pre-test probability of disease and season of testing have strong influence on the ability to diagnose PPID using basal adrenocorticotropic hormone (ACTH) or ACTH after thyrotropin-releasing hormone (TRH) stimulation. The overall diagnostic accuracy of basal ACTH concentrations for diagnosing PPID ranged between 88% and 92% in the autumn and 70% and 86% in the non-autumn, depending on the pre-test probability. Based on a single study, the overall diagnostic accuracy of ACTH concentrations in response to TRH after 30 minutes for diagnosing PPID ranged between 92% and 98% in the autumn and 90% and 94% in the non-autumn, depending on the pre-test probability. Thus, it should be remembered that the risk of a false positive result increases in situations where there is a low pre-test probability, which could mean that treatment is initiated for PPID without checking for a more likely alternative diagnosis. This could compromise horse welfare due to the commencement of lifelong therapy and/or failing to identify and treat an alternative potentially life-threatening condition. (B) Interpretation of diagnostic tests: (i) There is a significant effect of breed on plasma ACTH concentration, particularly in the autumn with markedly higher ACTH concentrations in some but not all 'thrifty' breeds; (ii) basal and/or post-TRH ACTH concentrations may also be affected by latitude/location, diet/feeding, coat colour, critical illness and trailer transport; (iii) mild pain is unlikely to have a large effect on basal ACTH, but caution may be required for more severe pain; (iv) determining diagnostic thresholds that allow for all possible contributory factors is not practical; therefore, the use of equivocal ranges is supported; (v) dynamic insulin testing and TRH stimulation testing may be combined, but TRH stimulation testing should not immediately follow an oral sugar test; (vi) equids with PPID and hyperinsulinaemia appear to be at higher risk of laminitis, but ACTH is not an independent predictor of laminitis risk. (C) Pharmacologic treatments and other treatment/management options: (i) Pergolide improves most clinical signs associated with PPID in the majority of affected animals; (ii) Pergolide treatment lowers basal ACTH concentrations and improves the ACTH response to TRH in many animals, but measures of insulin dysregulation (ID) are not altered in most cases; (iii) chasteberry has no effect on ACTH concentrations and there is no benefit to adding chasteberry to pergolide therapy; (iv) combination of cyproheptadine with pergolide is not superior to pergolide alone; (v) there is no evidence that pergolide has adverse cardiac effects in horses; (vi) Pergolide does not affect insulin sensitivity. (D) Monitoring pergolide-treated cases: (i) Hormone assays provide a crude indication of pituitary control in response to pergolide therapy, however it is unknown whether monitoring of ACTH concentrations and titrating of pergolide doses accordingly is associated with improved endocrinological or clinical outcome; (ii) it is unknown whether monitoring the ACTH response to TRH or clinical signs is associated with an improved outcome; (iii) there is very weak evidence to suggest that increasing pergolide dose in autumn months may be beneficial; (iv) there is little advantage in waiting for more than a month to perform follow-up endocrine testing following initiation of pergolide therapy; there may be merit in performing repeat tests sooner; (v) timing of sampling in relation to pergolide dosing does not confound measurement of ACTH concentration; (vi) there is no evidence that making changes after interpretation of ACTH concentrations measured at certain times of the year is associated with improved outcomes; (vii) evidence is very limited, however, compliance with PPID treatment appears to be poor and it is unclear whether this influences clinical outcome; (viii) evidence is very limited, but horses with clinical signs of PPID are likely to shed more nematode eggs than horses without clinical signs of PPID; it is unclear whether this results in an increased risk of parasitic disease or whether there is a need for more frequent assessment of faecal worm egg counts. MAIN LIMITATIONS: Limited relevant publications in the veterinary scientific literature. CONCLUSIONS: These findings should be used to inform decision-making in equine primary care practice.

Fitness and transcriptomic analysis of pathogenic Vibrio parahaemolyticus in seawater at different shellfish harvesting temperatures.

IMPORTANCE: Given the involvement of Vibrio parahaemolyticus (Vp) in a wide range of seafood outbreaks, a systematical characterization of Vp fitness and transcriptomic changes at temperatures of critical importance for seafood production and storage is needed. In this study, one of each virulent Vp strain (tdh+ and trh+) was tested. While no difference in survival behavior of the two virulent strains was observed at 10°C, the tdh+ strain had a faster growth rate than the trh+ strain at 30°C. Transcriptomic analysis showed that a significantly higher number of genes were upregulated at 30°C than at 10°C. The majority of differentially expressed genes of Vp at 30°C were annotated to functional categories supporting cellular growth. At 10°C, the downregulation of the biofilm formation and histidine metabolism indicates that the current practice of storing seafood at low temperatures not only protects seafood quality but also ensures seafood safety.

Utility of basal and peak TSH values in TRH stimulation testing for predicting the long-term therapeutic prognosis of primary congenital hypothyroidism.

In Japan, most neonates undergo screening for congenital hypothyroidism (CH). A TRH stimulation test (TRH-T) may be performed after initial treatment as a useful method for reevaluating the patient's thyroid status. However, no studies have compared basal and peak TSH values in TRH-T in patients with long-term follow-up. This was a retrospective and observational study. The inclusion criteria were as follows: (1) CH diagnosis based on positive newborn screening, (2) follow-up > 15 yr, and (3) TRH-T after LT4 discontinuation. The participants were divided into a no-treatment group (No-T group) and a treatment group (T group). The No-T and T groups included 14 and nine patients, respectively. The age at TRH-T was 5.38 yr for the No-T group and 4.25 yr for the T group, with no significant difference. The basal and peak TSH levels were significantly lower in the No-T group. The areas under the Receiver operating characteristic curve for basal and peak TSH values were 0.984 and 0.905, respectively. When the basal TSH level was under 4.594 IU/mL, the No-T group had a sensitivity of 1.00 and a specificity of 0.93. Basal TSH levels alone may be sufficient for predicting the long-term therapeutic prognosis of patients with CH.

The TRH test provides valuable information in the diagnosis of central hypothyroidism in patients with known pituitary disease and low T4 levels.

Objective: To evaluate the value of the thyrotropin-releasing hormone (TRH) test in the diagnosis of central hypothyroidism (CH) in patients with pituitary disease. Methods: Systematic evaluation of 359 TRH tests in patients with pituitary disease including measurements of thyroxine (T4), TBG-corrected T4 (T4corr), baseline TSH (TSH0) and relative or absolute TSH increase (TSHfold, TSHabsolute). Results: Patients diagnosed with CH (n=39) show comparable TSH0 (p-value 0.824) but lower T4corr (p-value <0.001) and lower TSH increase (p-value <0.001) compared to patients without CH. In 54% (42 of 78 cases) of patients with low T4corr, the CH diagnosis was rejected based on a high TSHfold. In these cases, a spontaneous increase and mean normalization in T4corr (from 62 to 73 nmol/L, p-value <0.001) was observed during the follow-up period (7.6 ± 5.0 years). Three of the 42 patients (7%) were started on replacement therapy due to spontaneous deterioration of thyroid function after 2.8 years. Patients diagnosed with CH reported significantly more symptoms of hypothyroidism (p-value 0.005), although, symptoms were reported in most patients with pituitary disease. The TRH test did not provide clinical relevant information in patients with normal T4 or patients awaiting pituitary surgery (78%, 281 of 359). There were only mild and reversible adverse effects related to the TRH test except for possibly one case (0.3%) experiencing a pituitary apoplexy. Conclusion: The TRH test could be reserved to patients with pituitary disease, low T4 levels without convincing signs of CH. Approximately 50% of patients with a slightly decreased T4 were considered to have normal pituitary thyroid function based on the TRH test results.

Diagnosis of equine pituitary pars intermedia dysfunction.

Equine pituitary pars intermedia dysfunction (PPID) is common in aged horses. The majority of horses respond well to treatment, but treatment is lifelong, meaning accurate diagnosis of PPID is important. Similar to any condition, there is no perfect laboratory test to diagnose PPID and accuracy is affected by the characteristics of the population in which the test is being evaluated. This review details the importance of consideration of clinical factors and diagnostic test accuracy. Basal adrenocorticotrophic hormone (ACTH) concentration is used most frequently in practice and has very good diagnostic accuracy when used in combination with clinical judgement and the correct application of diagnostic thresholds. The thyrotropin-releasing hormone stimulation test can be used in horses with equivocal test results following basal ACTH testing, or to evaluate subtle cases due to its improved accuracy.