Tissue-specific regulation of pyroglutamate aminopeptidase II activity by thyroid hormones

Among the enzymes capable of degrading thyrotropin-releasing hormone (TRH) in vitro, two pyroglutamate aminopeptidases (PGA) are specific for TRH: thyroliberinase, a seric enzyme and PGAII, a membrane-bound peptidase. The effect of thyroid hormone status on the activity of these enzymes was evaluated in serum and various tissues. Only in adenohypophysis, triiodothyronine treatment increased PGAII to 376% of control; hypothyroidism produced the reverse effect (decrease to 23% of control). As previously reported, similar changes were observed for thyroliberinase. TRH degradation at the adenohypophysis level may participate in the negative feedback control of thyroid hormones.     

The effect of amiloride on sodium and potassium fluxes in red cells

1. The effect of amiloride on the influx and efflux of (24)Na and (42)K in red cells was studied. The drug was added to the bathing Ringer or else incorporated in resealed ghosts.2. Amiloride does not inhibit the active or the passive (ouabain insensitive) extrusion of (24)Na.3. Amiloride inhibits the influx of (24)Na into red cells by 70%.4. Whether added to the inside or to the outside of the cells amiloride has no effect on the efflux of (42)K.5. Amiloride does not modify the uptake of (42)K from control Ringer. This uptake is strongly inhibited by the removal of Na. Amiloride has no effect on the extent of this inhibition.6. It is concluded that amiloride specifically inhibits the passive penetration of Na, and has no effect on the Na-K-pumping mechanism. However, at the concentration which inhibits 70% of the influx, amiloride fails to produce an observable effect on the ouabain-insensitive Na-efflux.7. On the basis that the information obtained could be extrapolated to other membranes, the effect of amiloride on epithelial membranes is discussed.     

Trauma-Informed Pediatric Primary Care: Facilitators and Challenges to the Implementation Process

This article describes the process of integrating trauma-informed behavioral health practices into a pediatric primary care clinic serving low-income and minority families while facing barriers of financial, staffing, and time limitations common to many community healthcare clinics. By using an iterative approach to evaluate each step of the implementation process, the goal was to establish a feasible system in which primary care providers take the lead in addressing traumatic stress. This article describes (1) the process of implementing trauma-informed care into a pediatric primary care clinic, (2) the facilitators and challenges of implementation, and (3) the impact of this implementation process at patient, provider, and community levels. Given the importance of trauma-informed care, especially for families who lack access to quality care, the authors conceptualize this paper as a guide for others attempting to integrate best behavioral health practices into pediatric clinics while working with limited resources.

     

Virtual Seminar on Coronavirus 2019 for the US-Mexico Border Region: Building Opportunities for Communication and Collaboration

While the US-Mexico border region has had increasing restrictions due to coronavirus 2019 (COVID-19), the economically and socially integrated region continues to facilitate necessary movement between the two countries. Binational partners representing universities, government, and health delivery worked together to develop a COVID-19 Virtual Seminar for the US-Mexico Border Region, which consisted of weekly sessions in Spanish designed to better facilitate communication and collaborative systems between border states. In total 835 participants registered for the virtual seminar with attendance ranging from 394 in Session 1 to 269 in Session 6. From evaluation surveys (n?=?297), organizers observed a large plurality of healthcare professionals, followed by students, researchers, and government employees. The seminar’s contribution to increasing collaborative and communication systems identified major needs in the region surrounding surveillance and monitoring; increased resources for migrant shelters to control outbreaks; an increase in personal protective equipment; tracking binational cases.

     

Neuroendocrine regulation of adrenal 5'-monodeiodination during acute cold exposure in the rat. I. Effects of hypophysectomy

Circulating levels of T4, T3, corticosterone, noradrenaline, and adrenaline, as well as 5'-monodeiodinase activity (5'-MA) were measured in control and hypophysectomized rats acutely exposed to cold environment (15-120 min, 4 C). In addition to the well known activation of the sympathoadrenomedullary system and the hypothalamic-pituitary-adrenal and-thyroid axes, cold exposure was followed by a rapid and sustained increase of 5'-MA in the hypothalamus, and a byphasic course of activation in the adrenal gland in control rats. The adrenal rapid activation (30 min) corresponded to the medulla and the slower activation (120 min) to the cortex. Both, the basal adrenal 5'-MA and the response to cold in adrenal and hypothalamus were 2-fold higher in hypophysectomized rats compared to control. The time course of enzyme activation in these structures suggests that: 1) organ-specific increases in 5'-MA may be associated to a simultaneous rise in their metabolic and/or functional activity, 2) the triggering mechanisms involves an immediate sympathetic signal activating the hypothalamic-adrenal medulla response and a pituitary signal eliciting a slower adrenocortical response, and 3) the compensatory sympathetic hyperactivity after panhypopituitarism contribute to enhance both the adrenal enzyme basal activity and the hypothalamic and adrenal hyperresponse to cold stress.     

Mammary gland sympathetic innervation is a major component in type 1 deiodinase regulation

Recent observations have shown that in lactating rats previously deprived of suckling, either suckling stimulus or ip injection of norepinephrine was capable of increasing mammary deiodinase type 1 (M-D1) mRNA content and enzyme activity. In the present work, we show that intact efferent sympathetic mammary innervation is required to restore both mammary D1 mRNA content and enzyme activity, whereas suckling-induced secretion of catecholamines from the adrenal glands does not seem to participate in M-D1 enzyme regulation. The data also indicate that the sympathetic reflex activation in response to suckling involves two complementary autonomic components: (1) activation, presumably through mammary segmental arrangement affecting neighboring mammary glands; and (2) an individual reflex regulatory mechanism capable of maintaining M-D1 activity within each mammary gland. In addition to these findings, we show that the suckling-induced sympathetic activation of M-D1 activity could be blocked by prior activation of ductal mechanoreceptors. This set of regulatory and counterregulatory mechanisms seems to ensure the optimal control of mammary energetic expenditure according to litter size.     

Presynaptic D1 dopamine receptors facilitate glutamatergic neurotransmission in the rat globus pallidus

The effects of D1/5 dopamine agonists on spontaneous excitatory postsynaptic currents (sEPSCs) were studied in neurons of the rat globus pallidus using whole-cell recordings in the presence of TTX and bicuculline. In this condition, CNQX abolished the sEPSCs, indicating that they were solely mediated by AMPA receptors. SKF 38393, a D1-like agonist, increased the frequency but not the amplitude of the sEPSCs, suggesting a presynaptic site of action. The increase in frequency was blocked by SCH 23390, a D1/5 antagonist. Quinpirole, a D2-like agonist, decreased the frequency but did not affect the amplitude of the synaptic currents. SKF 38393 increased the frequency of sEPSCs currents, even in presence of quinpirole, indicating that D1/5- and D2-like receptors independently modulate glutamate release upon a single neuron. The results suggest that the dopaminergic control of the glutamate transmission in the globus pallidus may play a role in processing cortical information in the indirect pathway of the basal ganglia.     

Dietary and nutraceutical approach to type 2 diabetes

Nutritional medical treatment is the first step to achieve adequate glycemic control and prevent diabetic complications. Lifestyle changes include moderate weight loss (7%) and regular physical activity (150 min/week). The appropriate diet composition is < 30% total fat, < 10% saturated fats, > 15 g/1000 kcal fiber, half soluble, 45–60% of carbohydrates with amoderate intake of sugar (50 g/day) and protein intake of 15–20% of the total calories a day. Patients need to limit the intake of saturated fats to < 7% of the daily calorie intake. Monounsaturated fatty acids such as olive oil and other vegetable oils are recommended. L-carnitine, α-lipoic acid, berberine and ω-3 fatty acids can be useful supplements.     

APOA1 (-75 G>A and 83 C>T) and APOB (2488 C>T) polymorphisms and their association with myocardial infarction,lipids and apolipoproteins in patients with type 2 diabetes mellitus

IntroductionThe increased risk of myocardial infarction (MI) in type 2 diabetes mellitus (T2DM) is well documented. Polymorphisms in APOA1 and APOB genes allow us to identify new genetic markers in the Mexican population with T2DM and MI.Material and methodsWe studied 135 patients with DMT2 and MI (DI); another 85 non-infarcted diabetic individuals with DMT2 but without previous ischemic events (NID) and 242 healthy subjects (HS). All three groups were selected with the aim to investigate the association between the polymorphisms and infarction when T2DM is present or absent.Results-75 G>A polymorphism: Differences were found in genotype distribution between DI and NID individuals (OR = 2.01, 95% CI: 1.117–3.623, p = 0.019) with an increased risk for A in the dominant model (OR = 1.77, 95% CI: 1.020–3.084, p = 0.042); also concentrations of ApoA-I for A/A were lower in comparison with G/A (p = 0.038) and LDL-C and HDL-C levels were lower in G/A compared to G/G carriers. 83 C>T polymorphism of APOA1: For DI individuals, HDL-C was lower in T/T compared to C/C and triglyceride levels were lower in C/T compared to C/C carriers.ConclusionsThe -75 G>A APOA1 polymorphism could be considered as a susceptibility factor for myocardial infarction in individuals with T2DM and 2488 C>T APOB polymorphism is associated with changes in HDL-C and LDL-C and triglycerides in the same group.