Pharmacological Doses Research Articles

The Pathophysiological Role of CoA.

The importance of coenzyme A (CoA) as a carrier of acyl residues in cell metabolism is well understood. Coenzyme A participates in more than 100 different catabolic and anabolic reactions, including those involved in the metabolism of lipids, carbohydrates, proteins, ethanol, bile acids, and xenobiotics. However, much less is known about the importance of the concentration of this cofactor in various cell compartments and the role of altered CoA concentration in various pathologies. Despite continuous research on these issues, the molecular mechanisms in the regulation of the intracellular level of CoA under pathological conditions are still not well understood. This review summarizes the current knowledge of (a) CoA subcellular concentrations; (b) the roles of CoA synthesis and degradation processes; and (c) protein modification by reversible CoA binding to proteins (CoAlation). Particular attention is paid to (a) the roles of changes in the level of CoA under pathological conditions, such as in neurodegenerative diseases, cancer, myopathies, and infectious diseases; and (b) the beneficial effect of CoA and pantethine (which like CoA is finally converted to Pan and cysteamine), used at pharmacological doses for the treatment of hyperlipidemia.

How predictive is body weight on fluid intake in rats? It depends on sex.

The assumption that body weight is a predictor of fluid intake is often used as rationale for normalizing intake to body weight when examining sex differences in drinking behavior. Nonuniform application of this body weight correction likely contributes to discrepancies in the literature. We, however, previously demonstrated sex differences in the relationship between body weight and angiotensin II (AngII)-stimulated water intake. Only after a pharmacological dose of AngII did water intake correlate with body weight, and only in males. Here we investigated whether body weight correlated with fluid intake stimulated by additional dipsogenic agents in male and female rats. We found that intake stimulated by either water deprivation or furosemide correlated with body weight in male rats. We found no relationship between intake and body weight after water deprivation, furosemide treatment, or isoproterenol treatment in females, nor did we find a relationship between intake and body weight after hypertonic saline treatment in either males or females. Finally, we report that daily water intake correlated with body weight in females. This effect, however, is likely the result of a relationship between body weight and food intake because when food was absent or reduced, the correlation between body weight and intake disappeared. These results demonstrate that multiple factors need to be considered when determining the best way to compare fluid intake between males and females and provides insight to help explain the discrepancies in the literature regarding sex differences in fluid intake.

Signaling in rat brainstem via Gpr160 is required for the anorexigenic and antidipsogenic actions of cocaine- and amphetamine-regulated transcript peptide.

Recent work identified Gpr160 as a candidate receptor for cocaine- and amphetamine-regulated transcript peptide (CARTp) and described its role in pain modulation. The aims of the present study were to determine if Gpr160 is required for the CARTp's ability to reduce food intake and water intake and to initially identify the distribution of Gpr160-like immunoreactivity (Gpr160ir) in the rat brain. A passive immunoneutralization approach targeting Gpr160 was used to block the behavioral effects of a pharmacological dose of CARTp in the fourth cerebroventricle (4V) of rats and to determine the importance of endogenously produced CARTp in the control of ingestive behaviors. Passive immunoneutralization of Gpr160 in the 4V blocked the actions of CARTp to inhibit food intake and water intake. Blockade of Gpr160 in the 4V, independent of pharmacological CART treatment, caused an increase in both overnight food intake and water intake. The decrease in food intake, but not water intake, caused by central injection of CARTp was demonstrated to be interrupted by prior administration of a glucagon-like peptide 1 (GLP-1) receptor antagonist. Gpr160ir was observed in several, distinct sites throughout the rat brain, where CARTp staining has been described. Importantly, Gpr160ir was observed to be present in both neuronal and nonneuronal cell types. These data support the hypothesis that Gpr160 is required for the anorexigenic actions of central CARTp injection and extend these findings to water drinking. Gpr160ir was observed in both neuronal and nonneuronal cell types in regions known to be important in the multiple pharmacological effects of CARTp, identifying those areas as targets for future compromise of function studies.

Lyophilized Human Platelets Restore Hemostasis in the Presence of the P2Y12 Inhibitors Cangrelor, Ticagrelor and Clopidogrel

• Background: P2Y12 inhibitors block platelet ADP receptors thereby reducing clotting capacity. In an emergency, these agents must be reversed or therapeutically overcome to stop bleeding. Additionally, prior to and during elective procedures these inhibitors must be withdrawn, thereby increasing thrombotic risk. Lyophilized human platelets (Thrombosomes®) are stabilized platelet derived hemostatic agents currently under Phase 2 clinical development for thrombocytopenia and have potential as antiplatelet reversal agents. • Aims: The aim of this study was to determine if lyophilized human platelets are resistant to the antiplatelet effect of P2Y12 inhibitors and therefore restore hemostasis in the presence of P2Y12 inhibitors. • Methods: Fresh drawn platelet rich plasma (PRP) was treated with pharmacological concentrations of P2Y12 inhibitors cangrelor or ticagrelor and confirmed to inhibit ADP-stimulated aggregation on the PAP-8E Platelet Aggregometer. Changes in hemostatic properties of the P2Y12 inhibitor treated PRP were also tested under shear force on the Total Thrombus formation Analysis System (T-TAS®). P2Y12 inhibitor treated PRP samples were dosed with lyophilized platelets and tested for return of hemostatic properties by T-TAS. NOD SCID mice were used in a tail snip model to determine hemostatic efficacy of Thrombosomes® after super pharmacological doses of clopidogrel treatment. • Results: Fresh PRP derived platelet aggregation response to ADP was inhibited by cangrelor or ticagrelor whereas lyophilized platelets did not respond to either inhibitor. Normal thrombus formation of PRP as measured by T-TAS occurred at 19.5± 1.5 minutes (n=4) but increases to 28.0±3.0 minutes with cangrelor (n=4) or 28.0±3.0 minutes with ticagrelor (n=5) treatment. The addition of 150k/µL lyophilized platelets to P2Y12-inhibited PRP reduced time to thrombus formation to lower than PRP alone; 15.5 ±0.5 minutes in the presence of cangrelor (n=3) versus 17.5 ±1.5 minutes in the presence of ticagrelor (n=5). In the in vivo tail snip mouse model animals treated with super pharmacological dose of clopidogrel bled for 18.0±10.0 minutes (n=5) unlike those not treated that only bleed for 9.5±2.5 minutes (n=6). Lyophilized platelet treated clopidogrel animals stopped bleeding at 12.5 ±4.5 minutes (n=5) after tail snip. • Conclusion: Lyophilized human platelets, unlike normal platelets were resistant to the antiplatelet effects of P2Y12 inhibitors. In vitro and in vivo studies reveal that lyophilized human platelets can be used to recover the anti-thrombotic effect of P2Y12 antagonists, potentially allowing continued drug compliance prior to elective procedures and as a possible treatment for emergent acute bleeding while on P2Y12 antagonist therapy. Disclosures Dickerson: Cellphire Inc.: Current Employment. Lee:Cellphire, Inc.: Current Employment. Hale:Cellphire: Current Employment. Moskowitz:Cellphire Inc.: Current Employment.

Plasma and urinary F2-isoprostane markers of oxidative stress are increased in cats with early (stage 1) chronic kidney disease.

Oxidative stress contributes to chronic kidney disease (CKD) progression in humans and rodent models; F2-isoprostanes (F2-IsoPs) are established biomarkers of oxidative stress. Our primary aim was to evaluate plasma F2-IsoPs in cats with International Renal Interest Society stage 1 and 2 CKD, compared with healthy cats, and to determine whether plasma and urinary F2-IsoPs are equivalent biomarkers. The secondary aim was to assess whether consumption of a renal diet enriched in omega-3 fatty acids led to improvements in plasma and urinary F2-IsoPs. Plasma and urinary F2-IsoPs were measured in 24 cats with stage 1 or 2 CKD, and 12 unaffected controls aged ⩾6 years. Twelve CKD cats were re-evaluated after feeding a commercial renal diet for at least 4 weeks. Median plasma F2-IsoPs were significantly higher in stage 1 CKD (96.2 pg/ml), early stage 2 CKD (83.2 pg/ml) and late stage 2 CKD (80.8 pg/ml) compared with healthy cats (22.8 pg/ml; P = 0.03-0.002). Median urinary F2-IsoPs were significantly higher in cats with stage 1 CKD (231.2 pg/mg) compared with healthy cats (152.5 pg/mg) or cats with late stage 2 CKD (124.8 pg/mg; P = 0.01). Plasma F2-IsoPs remained increased, while urinary F2-IsoPs fell with transition from stage 1 to stage 2 CKD. Feeding a commercial renal diet led to significant decreases in plasma F2-IsoPs in the small group of cats with stage 1 CKD (25-75% decrease) compared with cats with stage 2 CKD (20% decrease to 53% increase; P = 0.01). Oxidative stress is prominent in cats with stage 1 CKD. Plasma and urinary F2-IsoPs are not interchangeable biomarkers in cats with stage 2 CKD. Placebo-controlled studies are indicated to evaluate dietary or pharmacologic doses of omega-3 fatty acids on redox stress and progression of renal dysfunction in cats with stage 1 CKD.

Differential sensitivities of triple-negative breast cancer stem cell towards various doses of vitamin C: An insight into the internal antioxidant systems.

Cancer stem cells (CSCs) are quiescent and self-renewing, having low levels of reactive oxygen species (ROS), and are responsible for cancer recurrence after chemotherapy and radiotherapy. However, the interplay between the ROS production and scavenging from the oxidative stress has never been studied in breast CSCs. In this present study, we have investigatedthe cellular energetics of two triple-negative breast cancer stem cells (MDA-MB-231 and MDA-MB-468) treated with two pharmacological doses of vitamin C (10 and 20 mM) that generated ROS. Our results indicate a differential behavior of ROS scavenging by both the CSCs. MDA-MB-468 CSCs exhibited higher resistance to ROS induced damage owing to the higher antioxidant activity, lower mitochondrial damage, and less decrease in membrane potential (ΔΨm ) as compared with MDA-MB-231 CSCs. Moreover, MDA-MB-231 CSCs exhibited an intrinsic apoptosis pathway by activating the cytochrome c, caspase-9, 3, 7, and cleaved PARP upon treatment with vitamin C. This data suggestsa possible strategy for targeting breast CSCs using vitamin C. Taken together, the CSCs from MDA-MB-231 could be easily targeted by high/pharmacological doses of vitamin C (≥20 mM) thereby indicating a less robust internal antioxidant machinery.

P.470 A multicentre, pragmatic trial of a digital medicine system: results of the hummingbird study

Phosphodiesterase (PDE) 10A is an attractive therapeutic target for schizophrenia. Here, we investigated the antipsychotic-like effects of a novel PDE10A inhibitor, 1-({2-(7-fluoro-3-methylquinoxalin-2-yl)-5-[(3R)-3-fluoropyrrolidin-1-yl]pyrazolo[1,5-α]pyrimidin-7-yl}amino)-2-methylpropan-2-ol hydrochloride (MT-3014) in rats. MT-3014 showed a potent and selective inhibitory effect against PDE10A (IC50 = 0.357 nmol/L). Oral administration of MT-3014 (1.0–10 mg/kg) significantly increased the levels of cAMP, cGMP and cAMP response element-binding protein (CREB) phosphorylation in the rat striatum. MT-3014 decreased MK-801 (0.075 mg/kg)-induced hyperactivity (ED50 = 0.30 mg/kg) in a dose-dependent manner, although it decreased spontaneous locomotion in control rats (ED50 = 0.48 mg/kg); its effects were equivalent to those of risperidone. MT-3014 (0.3–3.0 mg/kg and 0.2 mg/kg) attenuated MK-801-induced prepulse inhibition deficits and cognitive deficits in rats, respectively, whereas risperidone attenuated MK-801-induced prepulse inhibition at only a high dose and failed to improve MK-801-induced cognitive deficits. Similar to risperidone (ID50 = 0.63 mg/kg), MT-3014 suppressed the conditioned avoidance response (ID50 = 0.32 mg/kg). Interestingly, MT-3014 did not elicit catalepsy and plasma prolactin increases at high doses. Furthermore, it also did not affect body weight. A positron emission tomography study using [11C]IMA107 showed a plasma concentration-dependent increase in brain PDE10A occupancy after oral administration of MT-3014 within the pharmacological dose range in rats. Brain PDE10A occupancy corresponding to the ID50 value in the conditioned avoidance response was approximately 60%, predicting the target occupancy in patients with schizophrenia. These results suggest that MT-3014 may be a novel antipsychotic drug, which is expected to have additional effects on cognitive impairment, without the prominent side effects associated with current atypical antipsychotics.

P.472 Effectiveness of pharmacotherapies for delusional disorder in a Swedish national cohort of 9076 patients

Phosphodiesterase (PDE) 10A is an attractive therapeutic target for schizophrenia. Here, we investigated the antipsychotic-like effects of a novel PDE10A inhibitor, 1-({2-(7-fluoro-3-methylquinoxalin-2-yl)-5-[(3R)-3-fluoropyrrolidin-1-yl]pyrazolo[1,5-α]pyrimidin-7-yl}amino)-2-methylpropan-2-ol hydrochloride (MT-3014) in rats. MT-3014 showed a potent and selective inhibitory effect against PDE10A (IC50 = 0.357 nmol/L). Oral administration of MT-3014 (1.0–10 mg/kg) significantly increased the levels of cAMP, cGMP and cAMP response element-binding protein (CREB) phosphorylation in the rat striatum. MT-3014 decreased MK-801 (0.075 mg/kg)-induced hyperactivity (ED50 = 0.30 mg/kg) in a dose-dependent manner, although it decreased spontaneous locomotion in control rats (ED50 = 0.48 mg/kg); its effects were equivalent to those of risperidone. MT-3014 (0.3–3.0 mg/kg and 0.2 mg/kg) attenuated MK-801-induced prepulse inhibition deficits and cognitive deficits in rats, respectively, whereas risperidone attenuated MK-801-induced prepulse inhibition at only a high dose and failed to improve MK-801-induced cognitive deficits. Similar to risperidone (ID50 = 0.63 mg/kg), MT-3014 suppressed the conditioned avoidance response (ID50 = 0.32 mg/kg). Interestingly, MT-3014 did not elicit catalepsy and plasma prolactin increases at high doses. Furthermore, it also did not affect body weight. A positron emission tomography study using [11C]IMA107 showed a plasma concentration-dependent increase in brain PDE10A occupancy after oral administration of MT-3014 within the pharmacological dose range in rats. Brain PDE10A occupancy corresponding to the ID50 value in the conditioned avoidance response was approximately 60%, predicting the target occupancy in patients with schizophrenia. These results suggest that MT-3014 may be a novel antipsychotic drug, which is expected to have additional effects on cognitive impairment, without the prominent side effects associated with current atypical antipsychotics.

Changes in Bone Metabolism and Structure in Primary Hyperparathyroidism

Abstract Parathyroid hormone (PTH) is a key regulator of bone turnover. Depending on the duration of action, the hormone causes catabolic and anabolic effects by binding with specific receptors (PTHR1) in the bone. Various cells expressing PTHR1 on their surface are involved in the process – osteoblasts, osteocytes, bone marrow stromal cells, T-lymphocytes and macrophages. In physiological conditions PTH balances the bone metabolism. Intermittent pharmacological doses of PTH lead to the prevalence of bone formation and are used in the treatment of osteoporosis. Persistently elevated levels of PTH stimulate bone resorption by impacting mainly the cortical bone. New imaging and analysis techniques show that high PTH levels can also have an adverse effect on trabecular microarchitecture. Primary hyperparathyroidism (PHPT) is a disease characterized by increased bone metabolism, decreased bone mineral density (BMD), inadequate osteoid mineralization and an increased risk of fractures. Prolonged overproduction of PTH leads to stimulation of bone resorption and defects in bone formation, mainly causing loss of cortical bone mass, while in the trabecular bone predominate demineralization processes. One explanation of these findings is the enhanced stimulation of RANKL expression by osteoblasts with decreased OPG expression and bone formation at the same time.

Different mechanisms of GIP and GLP-1 action explain their different therapeutic efficacy in type 2 diabetes

Background and aimsThe reduced action of incretin hormones in type 2 diabetes (T2D) is mainly attributed to GIP insensitivity, but efficacy estimates of GIP and GLP-1 differ among studies, and the negligible effects of pharmacological GIP doses remain unexplained. We aimed to characterize incretin action in vivo in subjects with normal glucose tolerance (NGT) or T2D and provide an explanation for the different insulinotropic activity of GIP and GLP-1 in T2D subjects. MethodsWe used in vivo data from ten studies employing hormone infusion or an oral glucose test (OGTT). To homogeneously interpret and compare the results of the studies we performed the analysis using a mathematical model of the β-cell incorporating the effects of incretins on the triggering and amplifying pathways. The effect on the amplifying pathway was quantified by a time-dependent factor that is greater than one when insulin secretion (ISR) is amplified by incretins. To validate the model results for GIP in NGT subjects, we performed an extensive literature search of the available data. Resultsa) the stimulatory effects of GIP and GLP-1 differ markedly: ISR potentiation increases linearly with GLP-1 over the whole dose range, while with GIP infusion it reaches a plateau at ~100 pmol/L GIP, with ISR potentiation of ~2 fold; b) ISR potentiation in T2D is reduced by ~50% for GIP and by ~40% for GLP-1; c) the literature search of GIP in NGT subjects confirmed the saturative effect on insulin secretion. ConclusionWe show that incretin potentiation of ISR is reduced in T2D, but not abolished, and that the lack of effects of pharmacological GIP doses is due to saturation of the GIP effect more than insensitivity to GIP in T2D.

Preparation and evaluation of kojic acid dipalmitate solid lipid nanoparticles

IntroductionNatural dissolution of kojic acid dipalmitate (KAD) in oil medium makes it difficult to load pharmacologic dose in a stable penetrative drug delivery system as topical dosage form. This study aimed to evaluate solid lipid nanoparticles (SLNs) as a drug delivery platform for the topical delivery KAD. MethodsSLNs were made with five different lipids and homogenization methods. The particle size was analyzed and the best lipid was chosen. Fourier-transform infrared spectroscopy, scanning electron microscopy, and differential scanning calorimetry were done. Then, KAD cream, KAD hydrogel, SLN-based KAD cream, and SLN-based KAD hydrogel were prepared and their release and permeation profile were evaluated on rat skin by Franz cell. ResultThe particle size of SLNs prepared with glycerol monostearate was about 70 nm. The optimum formulation was the combination with GMS 100 mg, KAD 10 mg, and ethanol/acetone in 2.5:1.5; all of which had the KAD entrapment efficiency of about 47%. The release of KAD powder was the fastest, and release from the SLN-based KAD hydrogel was slower than others. The KAD loaded in the SLN had the highest concentration in the stratum corneum, and KAD loaded in hydrogel formulation had the most concentration in the epidermis layer. ConclusionKAD can be loaded in the SLN with fair entrapment efficiency and particle size of <100 nm. KAD loaded in SLN-based cream made the maximum concentration of KAD in the epidermis compared with other formulations. Thus, SLN-based KAD cream is suggested as a proper topical formulation.

Effects of Hot-Melt Extruded Nano-Copper as an Alternative for the Pharmacological Dose of Copper Sulfate in Weanling Pigs.

This study was conducted to investigate the effects of hot-melt extrusion (HME)-processed copper (Cu) sulfate supplementation on the growth performance, gut microbiota, metabolic function of Cu, and bioavailability of Cu in weanling pigs fed a corn-soybean meal basal diets. A total of 180 piglets (Yorkshire × Landrace × Duroc) of mixed-sex randomly were allotted to six treatments on the basis of initial average body weight (6.36 ± 0.39kg) to six dietary treatments. There were six replicates in each treatment with 5 pigs per replicates. The dietary treatments included levels of CuSO4 (IN6, 6mg Cu/kg diets; IN125, 125mg Cu/kg diets), nano-CuSO4 (HME6, 6mg Cu/kg diets; HME65, 65mg Cu/kg diets; and HME125, 125mg Cu/kg diets), and Cu-methionine (ORG125, 125mg Cu/kg diets). The weanling pigs fed diets supplemented with the HME65 and HME125 showed a greater body weight and feed intake compared with IN6 and IN125 (P < 0.05). The weaning pigs fed diets supplemented with the HME125 showed the highest digestibility of gross energy in phase 1 and phase 2 (P < 0.05). The supplementation of HME125 significantly reduced theEscherichia coli (E.coli) in cecum and colon (P < 0.05). The supplementation of HME65 showed statistically equivalent effect on reduction of E. coli in the cecum and colon compared with IN125 and ORG125 treatments. The villus height in duodenum and jejunum of piglets in HME65 and HME125 treatments were higher than ORG125, HME6, IN6, and IN125 (P < 0.05). The gene expression of Atox1 was upregulated in IN125, HME125, and ORG125 treatments (P < 0.05). The expression of Sod1 was increased in IN125 treatment compared with IN6 treatment (P < 0.05). The HME125 treatment had the highest gene expression of ghrelin (P < 0.05). The Cu concentration of serum and liver was higher in the HME125 treatment than the HME6, IN6, and IN125 treatments (P < 0.05). The HME125 and ORG125 treatments showed a lower fecal Cu compared with IN125 treatment (P < 0.05). Taken together, these results suggest that the HME65 can be an alternative to IN125 in weanling pigs due to the greater overall average daily gain, improved villus height, and higher bioavailability.

Lithium in drinking water and crime rates in Japan: cross-sectional study.

In pharmacological doses, lithium successfully treats bipolar disorder and it can reduce violent crimes committed by individuals with this disorder. To investigate whether naturally occurring lithium in drinking water lowers rates of violent crime in the general population. We examined lithium levels in the drinking water of the 274 municipalities of Kyushu Island in Japan and compared these with the crime rates in each municipality. We found that lithium levels were significantly and inversely associated with crime rates in 2009. Our findings suggest that even very low levels of lithium in drinking water may play a role in reducing crime rates in the general population.

A single dose of estrogen during hemorrhagic shock protects against Kidney Injury whereas estrogen restoration in ovariectomized mice is ineffective

The protective effect of estrogens against chronic glomerular diseases is admitted but remains debated during acute kidney injury (AKI). Using a model of resuscitated hemorrhagic shock in C57/Bl6 female mice, this study evaluated at 1 and 21 days the renal effect of (1) endogenous estrogen, using ovariectomized mice with or without chronic estrogen restoration, or (2) exogenous estrogen, using a single administration of a pharmacological dose during shock resuscitation. In both ovariectomized and intact mice, hemorrhagic shock induced epithelial cell damages (assessed by KIM-1 renal expression) with secondary renal fibrosis but without significant decrease in GFR at day 21. Ovariectomy with or without estrogen restoration have no significant effect on renal damages and dysfunction. This lack of effect was associated with a marked (> 80%) reduction of total kidney GPR30 expression. By contrast, a single high dose of estradiol in intact mice reduced renal KIM-1 expression by 2/3, attenuated the severity of cell death related to pyroptosis, and prevented the increase of fibrosis by 1/3. This provides a rationale to investigate the benefits of a single administration of estrogen or estrogen modulators during acute kidney injuries in males. Furthermore, the cost/benefit ratio of such administration should be investigated in Human.

Regulation of extracellular and intracellular prolactin on cell proliferation and survival rate through GHR/JAK2/STAT3 pathway in NSCLC

Styrene increases serum prolactin (PRL) concentration. Hyperprolactinemia is associated with poor prognosis in lung cancer patients, but the mechanism of PRL action is unclear. The aims of this study were to (i) investigate the mechanism of PRL-action receptor in NSCLC cells (ii) measure whether PRL was secreted by NSCLC cells and its stimulatory mechanism in vitro and in vivo. We found that cell proliferation was increased after treatment of a pharmacological dose of PRL in A549 cells, which through up regulation of growth hormone receptor (GHR) and downstream of JAK2/STAT3/VEGF pathway. All NSCLC cells in the present study secreted PRL and expressed GHR, but not PRLR. Inhibition of GHR protein level led to decrease the PRL-induced cell proliferation. PRL was detected in NSCLC cells culture medium. Knockdown of intracellular PRL downregulated JAK2/STAT3 protein activities and GHR and VEGF protein levels. Furthermore, knockdown of intracellular PRL reduced the cell proliferation and the ability of colony-forming. In lung cancer tissues, PRL, GHR and VEGF levels were higher in the tumor tissues than in normal tissues and the protein expressions of these three proteins are positively correlated, respectively. High expression levels of both PRL and GHR cause a poor survival rate in lung cancer patients. Taken together, our results suggested that extracellular and intracellular PRL were involved in cell proliferation through GHR. Combination of in vitro and in vivo results, GHR and PRL are important targets for suppressing NSCLC cell proliferation, which might improve the survival rate in NSCLC patients.

Effect of growth hormone therapy on thyroid function in isolated growth hormone deficient and short small for gestational age children: a two-year study, including on assessment of the usefulness of the thyrotropin-releasing hormone (TRH) stimulation test.

Background The relationship between growth hormone (GH)-replacement therapy and the thyroid axis in GH-deficient (GHD) children remains controversial. Furthermore, there have been few reports regarding non-GHD children. We aimed to determine the effect of GH therapy on thyroid function in GHD and non-GHD children and to assess whether thyrotropin-releasing hormone (TRH) stimulation test is helpful for the identification of central hypothyroidism before GH therapy. Methods We retrospectively analyzed data from patients that started GH therapy between 2005 and 2015. The free thyroxine (FT4) and thyroid-stimulating hormone (TSH) concentrations were measured before and during 24months of GH therapy. The participants were 149 children appropriate for gestational age with GHD (IGHD: isolated GHD) (group 1), 29 small for gestational age (SGA) children with GHD (group 2), and 25 short SGA children (group 3). Results In groups 1 and 2, but not in group 3, serum FT4 concentration transiently decreased. Two IGHD participants exhibited central hypothyroidism during GH therapy, and required levothyroxine (LT4) replacement. They showed either delayed and/or prolonged responses to TRH stimulation tests before start of GH therapy. Conclusions GH therapy had little pharmacological effect on thyroid function, similar changes in serum FT4 concentrations were not observed in participants with SGA but not GHD cases who were administered GH at apharmacological dose. However, two IGHD participants showed central hypothyroidism and needed LT4replacement therapy during GH therapy. TRH stimulation test before GH therapy could identify such patients and provoke careful follow-up evaluation of serum FT4 and TSH concentrations.

Amelioration of adrenaline induced oxidative gastrointestinal damages in rat by melatonin through SIRT1-NFκB and PGC1α-AMPKα cascades

Adrenaline at high pharmacological doses may lead to oxidative damages in diverse organs including gut. In this study, we attempt to elucidate the potentially protective effects of melatonin on gastrointestinal (GI) tissue damages induced by adrenaline. Rats were injected (s.c.) with different doses (0.125, 0.25 and 0.50 mg/kg) of adrenaline bitartrate (AD) for 15 days with or without melatonin (2.5, 5 and 10 mg/kg; orally). The results showed that adrenaline caused massive histological and ultra-structural GI injuries and melatonin (20 mg/kg) effectively protected these injuries. The protective mechanisms are related to the antioxidant and anti-inflammatory activities of melatonin indicated by increased glutathione levels and antioxidant enzymes as well as decreased oxidative stress markers and pro-inflammatory cytokines in GI tissues. The signal pathways of melatonin include up-regulating expression of Nrf2, SIRT1 and Bcl2, while down-regulating NFκB, TNFα and Bax. Melatonin also targeted mitochondrial energy homeostasis and biogenesis by up-regulating expression of PGC1α, AMPKα and SOD2 and reduced leakage of cytochrome c. The SIRT1-NFκB and PGC1α-AMPKα signal transduction pathways seem to play the central roles involving in melatonin’s protective effects on gastric damages induced by the high doses of adrenaline.

Efficacy of corticosteroid in decreasing scoliosis and extending time to loss of ambulation in a single clinic: an effectiveness trial.

PurposePharmacologic doses of corticosteroid (CS) have been shown to ameliorate the progression of Duchenne muscular dystrophy (DMD) preserving strength, pulmonary function and ambulation as well as reducing the incidence of scoliosis. However, there are serious side effects of CS, which may impact dose tolerance. The purpose of this study was to compare the magnitude of positive CS effects on patients in our clinic to those reported in the literature.MethodsWe retrospectively reviewed medical records and radiographs of 142 DMD patients who were seen between 1st January 1991 and 31st December 2017.ResultsIn total, 101 boys met study inclusion criteria. Of these 32 were steroid naïve, 37 took the recommended dose (standard of care, SOC) of Prednisone or Deflazacort, and 32 took a lower dose (LD). Following initiation of CS, both treatment groups showed an increase in weight velocity and decrease in linear growth velocity. Although there was a trend to later loss of ambulation (LOA) in the SOC group relative to the naïve group by one year, this was not significant, however, a small subgroup of boys on Deflazacort showed a 3.4 year later LOA than the naïve group. The incidence of scoliosis was reduced from 69% in the naïve, to 41% in the LD and 47% in the SOC group.ConclusionsAlthough there was a reduction in the incidence of scoliosis, it was not as robust as seen elsewhere. Many published studies have inadequate data on scoliosis probably due to the lack of inclusion of orthopaedists in the study group.Level of evidenceIV

Lessons Learned from Inherited Metabolic Disorders of Sulfur-Containing Amino Acids Metabolism

The metabolism of sulfur-containing amino acids (SAAs) requires an orchestrated interplay among several dozen enzymes and transporters, and an adequate dietary intake of methionine (Met), cysteine (Cys), and B vitamins. Known human genetic disorders are due to defects in Met demethylation, homocysteine (Hcy) remethylation, or cobalamin and folate metabolism, in Hcy transsulfuration, and Cys and hydrogen sulfide (H2S) catabolism. These disorders may manifest between the newborn period and late adulthood by a combination of neuropsychiatric abnormalities, thromboembolism, megaloblastic anemia, hepatopathy, myopathy, and bone and connective tissue abnormalities. Biochemical features include metabolite deficiencies (e.g. Met, S-adenosylmethionine (AdoMet), intermediates in 1-carbon metabolism, Cys, or glutathione) and/or their accumulation (e.g. S-adenosylhomocysteine, Hcy, H2S, or sulfite). Treatment should be started as early as possible and may include a low-protein/low-Met diet with Cys-enriched amino acid supplements, pharmacological doses of B vitamins, betaine to stimulate Hcy remethylation, the provision of N-acetylcysteine or AdoMet, or experimental approaches such as liver transplantation or enzyme replacement therapy. In several disorders, patients are exposed to long-term markedly elevated Met concentrations. Although these conditions may inform on Met toxicity, interpretation is difficult due to the presence of additional metabolic changes. Two disorders seem to exhibit Met-associated toxicity in the brain. An increased risk of demyelination in patients with Met adenosyltransferase I/III (MATI/III) deficiency due to biallelic mutations in the MATIA gene has been attributed to very high blood Met concentrations (typically >800μmol/L) and possibly also to decreased liver AdoMet synthesis. An excessively high Met concentration in some patients with cystathionine β-synthase deficiency has been associated with encephalopathy and brain edema, and direct toxicity of Met has been postulated. In summary, studies in patients with various disorders of SAA metabolism showed complex metabolic changes with distant cellular consequences, most of which are not attributable to direct Met toxicity.

The Vitamin D Receptor in Osteoblast-Lineage Cells Is Essential for the Proresorptive Activity of 1α,25(OH)2D3 In Vivo.

We previously reported that daily administration of a pharmacological dose of eldecalcitol, an analog of 1α,25-dihydroxyvitamin D3 [1α,25(OH)2D3], increased bone mass by suppressing bone resorption. These antiresorptive effects were found to be mediated by the vitamin D receptor (VDR) in osteoblast-lineage cells. Using osteoblast-lineage-specific VDR conditional knockout (Ob-VDR-cKO) mice, we examined whether proresorptive activity induced by the high-dose 1α,25(OH)2D3 was also mediated by VDR in osteoblast-lineage cells. Administration of 1α,25(OH)2D3 (5 μg/kg body weight/day) to wild-type mice for 4 days increased the number of osteoclasts in bone and serum concentrations of C-terminal crosslinked telopeptide of type I collagen (CTX-I, a bone resorption marker). The stimulation of bone resorption was concomitant with the increase in serum calcium (Ca) and fibroblast growth factor 23 (FGF23) levels, and decrease in body weight. This suggests that a toxic dose of 1α,25(OH)2D3 can induce bone resorption and hypercalcemia. In contrast, pretreatment of wild-type mice with neutralizing anti-receptor activator of NF-κB ligand (RANKL) antibody inhibited the 1α,25(OH)2D3-induced increase of osteoclast numbers in bone, and increase of CTX-I, Ca, and FGF23 levels in serum. The pretreatment with anti-RANKL antibody also inhibited the 1α,25(OH)2D3-induced decrease in body weight. Consistent with observations in mice conditioned with anti-RANKL antibody, the high-dose administration of 1α,25(OH)2D3 to Ob-VDR-cKO mice failed to significantly increase bone osteoclast numbers, serum CTX-I, Ca, or FGF23 levels, and failed to reduce the body weight. Taken together, this study demonstrated that the proresorptive, hypercalcemic, and toxic actions of high-dose 1α,25(OH)2D3 are mediated by VDR in osteoblast-lineage cells.