Melatonin (Low-dose 0.3mg)

STUDY OBJECTIVE: Compare adverse effects and analgesic efficacy of low-dose ketamine for acute pain in the ED administered either by single intravenous push (IVP) or short infusion (SI). METHODS: Patients 18-65, presenting to ED with acute abdominal, flank, or musculoskeletal pain with initial pain score≥5, were randomized to ketamine 0.3mg/kg by either IVP or SI with placebo double-dummy. Adverse effects were evaluated by Side Effects Rating Scale for Dissociative Anesthetics (SERSDA) and Richmond Agitation-Sedation Scale (RASS) at 5, 15, 30, 60, 90, and 120min post-administration; analgesic efficacy was evaluated by Numerical Rating Scale (NRS). RESULTS: 48 patients enrolled in the study. IVP group had higher overall rates of feeling of unreality on SERSDA scale: 92% versus 54% (difference 37.5%; p=0.008; 95% CI 9.3-59.5%). At 5min median severity of feeling of unreality was 3.0 for IVP versus 0.0 for SI (p=0.001). IVP also showed greater rates of sedation on RASS scale at 5min: median RASS -2.0 versus 0.0 (p=0.01). Decrease in mean pain scores from baseline to 15min was similar across groups: 5.2±3.53 (95% CI 3.7-6.7) for IVP; 5.75±3.48 (95% CI 4.3-7.2) for SI. There were no statistically significant differences with respect to changes in vital signs and need for rescue medication. CONCLUSION: Low-dose ketamine given as a short infusion is associated with significantly lower rates of feeling of unreality and sedation with no difference in analgesic efficacy in comparison to intravenous push.

BACKGROUND: To date, no data have been reported on the pharmacokinetic and pharmacodynamic properties of landiolol, a fast-acting cardioselective β1-adrenergic antagonist, in non-Asian subjects. The aim of this study was to compare two landiolol formulations in healthy Caucasian subjects. MATERIALS AND METHODS: We conducted a single-center, prospective, double-blinded, randomized study in two cross-over periods with 12 healthy subjects (7 women and 5 men) each receiving three doses (0.1, 0.2, and 0.3mg/kg BW) of Onoact® 50 Lyophilized powder (50mg) or Rapibloc® concentrate IV (20mg/2mL) to evaluate the pharmacokinetics (PK), pharmacodynamics (PD), safety, and tolerability of the two landiolol formulations. RESULTS: For both formulations, maximum blood concentrations of landiolol were rapidly reached (median tmax 2.3±0.65 and 2.8±1.13min for the high dose of each formulation). The compounds had a short half-life (t1/2=3.2±1.2min and 3.0±1.1min for the low dose of the concentrate formulation and the lyophilized powder, respectively). The results showed no statistically significant differences between both formulations of landiolol for any PK parameters, at study doses. Both formulations dose-dependently and significantly decreased the heart rate values from 62.2bpm at baseline to minimum values of 55-56, 52-53, and 50-52bpm after 0.1, 0.2, and 0.3mg/kg respectively. This bradycardic effect was achieved within 1 to 3min. The decrease in systolic blood pressure (baseline: 107mmHg, minimum values were around 99mmHg) was significant but not dose dependent, and occurred within 3 to 12min. Seven mild to moderate AEs occurred after administration of the concentrate formulation. No SAEs were reported in this study. CONCLUSION: In Caucasians, both landiolol formulations showed similar pharmacokinetic behaviours, displaying very short half-lives (3.0 to 3.6min). In addition, after administration of both formulations, the landiolol-induced heart rate reduction showed fast onset and dose dependence, whilst the decrease of systolic blood pressure occurred more slowly, was less pronounced, and dose independent. In summary, both landiolol formulations delivered comparable plasma

Venezuelan equine encephalitis virus (VEEV), a mosquito-borne alphavirus, causes periodic epizootics in equines and is a recognized biological defense threat for humans. There are currently no FDA-licensed vaccines against VEEV. We developed a candidate DNA vaccine expressing the E3-E2-6K-E1 genes of VEEV (pWRG/VEE) and performed a Phase 1 clinical study to assess the vaccine's safety, reactogenicity, tolerability, and immunogenicity when administered by intramuscular (IM) or intradermal (ID) electroporation (EP) using the Ichor Medical Systems TriGrid™ Delivery System. Subjects in IM-EP groups received 0.5mg (N=8) or 2.0mg (N=9) of pWRG/VEE or a saline placebo (N=4) in a 1.0ml injection. Subjects in ID-EP groups received 0.08mg (N=8) or 0.3mg (N=8) of DNA or a saline placebo (N=4) in a 0.15ml injection. Subjects were monitored for a total period of 360 days. No vaccine- or device-related serious adverse events were reported. Based on the results of a subject questionnaire, the IM- and ID-EP procedures were both considered to be generally acceptable for prophylactic vaccine administration, with the acute tolerability of ID EP delivery judged to be greater than that of IM-EP delivery. All subjects (100%) in the high and low dose IM-EP groups developed detectable VEEV-neutralizing antibodies after two or three administrations of pWRG/VEE, respectively. VEEV-neutralizing antibody responses were detected in seven of eight subjects (87.5%) in the high dose and five of eight subjects (62.5%) in the low dose ID-EP groups after three vaccine administrations. There was a correlation between the DNA dose and the magnitude of the resulting VEEV-neutralizing antibody responses for both IM and ID EP delivery. These results indicate that pWRG/VEE delivered by either IM- or ID-EP is safe, tolerable, and immunogenic in humans at the evaluated dose levels. Clinicaltrials.gov registry number NCT01984983. Published by Elsevier Ltd.

OBJECTIVES: To compare the maximum change in numeric rating scale (NRS) pain scores, in patients receiving low-dose ketamine (LDK) or morphine (MOR) for acute pain in the emergency department. METHODS: We performed an institutional review board-approved, randomized, prospective, double-blinded trial at a tertiary, level 1 trauma center. A convenience sample of patients aged 18 to 59 years with acute abdominal, flank, low back, or extremity pain were enrolled. Subjects were consented and randomized to intravenous LDK (0.3mg/kg) or intravenous MOR (0.1mg/kg). Our primary outcome was the maximum change in NRS scores. A sample size of 20 subjects per group was calculated based on an 80% power to detect a 2-point change in NRS scores between treatment groups with estimated SDs of 2 and an α of .05, using a repeated-measures linear model. RESULTS: Forty-five subjects were enrolled (MOR 21, LDK 24). Demographic variables and baseline NRS scores (7.1 vs 7.1) were similar. Ketamine was not superior to MOR in the maximum change of NRS pain scores, MOR=5 (confidence interval, 6.6-3.5) and LDK=4.9 (confidence interval, 5.8-4). The time to achieve maximum reduction in NRS pain scores was at 5 minutes for LDK and 100 minutes for MOR. Vital signs, adverse events, provider, and nurse satisfaction scores were similar between groups. CONCLUSION: Low-dose ketamine did not produce a greater reduction in NRS pain scores compared with MOR for acute pain in the emergency department. However, LDK induced a significant analgesic effect within 5 minutes and provided a moderate reduction in pain for 2 hours.

AIMS: The role of low-dose dopamine infusion in patients with acute decompensated heart failure (ADHF) remains controversial. We aim to evaluate the efficacy and safety of high- versus low-dose furosemide with or without low-dose dopamine infusion in this patient population. METHODS AND RESULTS: 161 ADHF patients (78 years; 46% female; ejection fraction 31%) were randomized to 8-hour continuous infusions of: a) high-dose furosemide (HDF, n=50, 20mg/h), b) low-dose furosemide and low-dose dopamine (LDFD, n=56, 5mg/h and 5 μg kg(-1)min(-1) respectively), or c) low-dose furosemide (LDF, n=55, furosemide 5mg/h). The main outcomes were 60-day and one-year all-cause mortality (ACM) and hospitalization for HF (HHF). Dyspnea relief (Borg index), worsening renal function (WRF, rise in serum creatinine (sCr) ≥ 0.3mg/dL), and length of stay (LOS) were also assessed. The urinary output at 2, 4, 6, 8, and 24h was not significantly different in the three groups. Neither the ACM at day 60 (4.0%, 7.1%, and 7.2%; P=0.74) or at one year (38.1%, 33.9% and 32.7%, P=0.84) nor the HHF at day 60 (22.0%, 21.4%, and 14.5%, P=0.55) or one year (60.0%, 50.0%, and 47%, P=0.40) differed between HDF, LDFD, and LDF groups, respectively. No differences in the Borg index or LOS were noted. WRF was higher in the HDF than in LDFD and LDF groups at day 1 (24% vs. 11% vs. 7%, P<0.0001) but not at sCr peak (44% vs. 38% vs. 29%, P=0.27). No significant differences in adverse events were noted. CONCLUSIONS: In ADHF patients, there were no significant differences in the in-hospital and post-discharge outcomes between high- vs. low-dose furosemide infusion; the addition of low-dose dopamine infusion was not associated with any beneficial effects.

Classical risk assessment models for setting safe occupational exposure limits (OEL) have used multiple uncertainty factors (UF) applied to a point of departure (POD), e.g., a No Observed Effect Level (NOEL), which in some cases is the pharmacological effect. Dapagliflozin promotes glucosuria by inhibiting the renal sodium-glucose cotransporter-2 transporter. The initial OEL for dapagliflozin (0.002mg/m(3)) was calculated when low dose clinical data was not available to identify a NOEL resulting in the need to use excessive UFs. To reduce the UFs from the OEL, a clinical pharmacodynamic [glucosuria and urinary glucose dipstick (UGD)] and pharmacokinetic study was conducted with single oral doses of 0.001, 0.01, 0.1, 0.3, 1.0 or 2.5mg administered to 36 healthy subjects. Dose-related dapagliflozin systemic exposures were observed at doses ⩾0.1mg and glucosuria was observed at doses ⩾0.3mg and corroborated by UGD. The NOEL was therefore 0.1mg for glucosuria. For setting the new OEL, no UFs were required. Dividing the POD by 10m(3) (the volume of air an adult inhales in a workday), the resulting OEL was 0.01mg/m(3). In conclusion, low-dose clinical pharmacodynamic and pharmacokinetic data can allow the OEL to be adjusted to the highest safe level.

In an 8-week, multicenter, randomized, double-blind study, we evaluated the efficacy and tolerability of pantoprazole (0.3mg/kg [low dose (LD)], 0.6 mg/kg [medium dose (MD)], and 1.2 mg/kg [high dose (HD)]) for delayed-release oral suspension (granules) in patients 1 to 5 years with documented symptoms of gastroesophageal reflux disease (GERD) and endoscopic evidence of reflux-related erosive esophagitis (EE) or histologic esophagitis (HE) consistent with GERD. Patients with HE were randomly assigned to LD, MD, or HD, and patients with EE, to MD or HD. A daily eDiary captured 5 individual GERD symptoms. A total of 60 patients (56 HE, 4 EE) were randomized. Mean weekly GERD symptom score (WGSS, sum of weekly mean frequency scores for 5 individual GERD symptoms) for the modified intention-to-treat HE population at the final week was improved with LD ( P < .001), MD (P = .063), and HD (P < 0.001) (paired t-tests). Patients with EE were healed at week 8. Adverse event incidences did not increase with dose.

Sleep disturbances in peri- and postmenopausal women may result from hormonal changes, vasomotor symptoms, and possibly psychological factors. Hormone replacement therapy (HRT) seems to diminish the disruption of sleep in climacteric women. The aim of this study was to determine the effects of a low dose of conjugated equine estrogens (CE) in combination with different progestins (LD-HRT) and evaluate differences between regimens on sleep in symptomatic postmenopausal women. Postmenopausal women were recruited and assigned to calcium-vitamin (control group) or to LD-HRT with 0.3mg of CE associated with a daily administration at bedtime of a progestin (2.5 mg MPA, CE + MPA, n = 20), or 100 mg natural micronized progesterone (CE + P, n = 20). Subjective symptoms were evaluated by the Greene climacteric scale, and by a visuanalogic graduated scale (0-10) at baseline and after 4, 8, and 12 weeks of study. Greene's scores for the control group were similar to those in LD-HRT group at baseline, and showed no significant modification at all subsequent measurements. Conversely, in LD-HRT group, a significant (P < 0.05) reduction in the scores of all Greene's domains was evident versus corresponding baseline and control group values. Conversely, in LD-HRT group, a significant (P < 0.05) reduction in the scores of all Greene's domains was evident with no difference in the scores of the two treated group. Both CE + MPA and CE + P significantly (P = 0.05) reduced the HF and sleep visuanalogic score in comparison to the control group. The score of sleep was significantly (P = 0.05) lower in the CE + P group in comparison to that measured in the CE + MPA group. No significant correlation between sleep and vasomotor score was found. In conclusion, low estrogen dose may have a value in the treatment of menopausal women in which sleep disturbances may be a symptom of estrogen deprivation. Low-dose estrogen associated with low-dose micronized progesterone may especially benefit women who complain of disturbed sleep.

BACKGROUND AND OBJECTIVES: Ketamine is increasingly being utilized in the management of acute pain in the emergency department (ED), including for older adults, a population at increased risk of adverse effects from medications. We aimed to compare the safety and analgesic effects of high-dose (≥0.3mg/kg) to low-dose (<0.3mg/kg) intravenous (IV) ketamine among older ED patients. METHODS: Multi-center, retrospective cohort study of adults ≥60years who received IV ketamine for pain between 2018 and 2021. The primary outcome was pain improvement as measured by the Numerical Rating Scale (NRS) pain score within 60min after administration. Secondary outcomes included adverse effects (early discontinuation, nausea, rescue benzodiazepines and intubation) and the need for rescue analgesia. Linear regression was used to assess the association between the change in NRS pain scores and dose after adjusting for baseline pain, requiring an additional dose of ketamine, and receiving an opioid. RESULTS: A total of 130 older adults received ketamine as an analgesic (37 high-dose, 93 low-dose). Median age was 69.2years, 52 % were women, 40 % had a history of substance use disorder. Prior to ketamine, 76 % received alternate analgesics and 23 % antiemetics. Baseline mean pain score was lower in the high-dose group (6.7 vs. 8.3, difference -1.7 [95 % CI -2.6 to -0.7], p = 0.013). Change in NRS pain scores were similar between the high-dose and low-dose groups (-2.4 [95 % CI -3.6 to -1.3] vs -1.6 [95 % CI -2.2 to -0.9], p = 0.27). After adjustment for baseline pain score, the high-dose group had a larger reduction in pain scores (-1.3 [95 % CI -2.6 to -0.1], p = 0.042) and percent change of pain (-23.8 % [95 % CI -42.1 % to -5.4 %], p = 0.012). There was no significant difference in rates of rescue analgesia (35.1 % vs. 44.1 %, p = 0.35) or early discontinuation (29.7 % vs. 32.3 %, p = 0.78). Rates of adverse effects were similar. CONCLUSION: High-dose and low-dose ketamine reduced pain scores in older adults. High-dose ketamine led to a greater reduction in pain scores, and there was no observed difference in adverse effects or the need for rescue analgesia. One-third needed disco

The rising prevalence of early-life opioid exposure has become a pressing public health issue in the U.S. Neonates exposed to opioids in utero are at risk of experiencing a constellation of postpartum withdrawal symptoms commonly referred to as neonatal opioid withdrawal syndrome (NOWS). Buprenorphine (BPN), a partial agonist at the mu-opioid receptor (MOR) and antagonist at the kappa-opioid receptor (KOR), is currently approved to treat opioid use disorder in adult populations. Recent research suggests that BPN may also be effective in reducing withdrawal symptoms in neonates who were exposed to opioids in utero. We sought to determine whether BPN attenuates somatic withdrawal in a mouse model of NOWS. Our findings indicate that the administration of morphine (10mg/kg, s.c.) from postnatal day (PND) 1-14 results in increased somatic symptoms upon naloxone-precipitated (1mg/kg, s.c.) withdrawal. Co-administration of BPN (0.3mg/kg, s.c.) from PND 12-14 attenuated symptoms in morphine-treated mice. On PND 15, 24h following naloxone-precipitated withdrawal, a subset of mice was examined for thermal sensitivity in the hot plate test. BPN treatment significantly increased response latency in morphine-exposed mice. Lastly, neonatal morphine exposure elevated mRNA expression of KOR, and reduced mRNA expression of corticotropin-releasing hormone (CRH) in the periaqueductal gray when measured on PND 14. Altogether, this data provides support for the therapeutic effects of acute low-dose buprenorphine treatment in a mouse model of neonatal opioid exposure and withdrawal.

INTRODUCTION: The nature of thyroid nodules is heterogenous. Most of them are benign and, in the absence of pressure symptoms of adjunct structures, no treatment is needed. Our objective was to investigate the acute effects of a low dose of recombinant human TSH (rhTSH) on the volume of benign thyroid nodules. METHODS: we studied 27 nodules (14 isoechoic and 13 hypoechoic) in 15 (11 women and 4 men; mean age: 51.0 ± 15.9 years) consecutive patients with one to three well-separated asymptomatic benign thyroid nodules. All subjects were euthyroid, with negative thyroid antibodies, and none received levothyroxine. The total thyroid volume and thyroid nodule volume were sonographically determined by two independent examiners (P.B. and M.M.) before, 48 hours and 6 months post intramuscular (IM) administration of 0.3mg rhTSH, and the mean values of the two examiners' measurements were used; thyroid function tests were obtained at the same time points. RESULTS: The mean volume of isoechoic nodules increased by 57.3%, of hypoechoic nodules by 46.6% and of the surrounding thyroid parenchyma by 70.4% 48 hours post-rhTSH; mean volumes had returned to baseline levels 6 months later. A large variance in the volume change responses was observed. The relative change in nodule volume (defined as the percent change in nodule volume divided by the percent change in the surrounding parenchyma) from baseline to 48 hours was significantly higher in isoechoic versus hypoechoic nodules (p<0.05). CONCLUSIONS: A single dose of 0.3 mg rhTSH transiently increased the volume of benign thyroid nodules. The increase was more pronounced in isoechoic nodules and had a great variability. Our findings could be useful in the management of benign thyroid nodules, by helping in understanding which nodules would be more responsive to TSH suppression therapy.

INTRODUCTION: Efficient treatment of asthma can play an important role in controlling asthma attacks, rapid recovery and decrease of patient mortality. Therefore, in the present study the therapeutic effect of low-dose ketamine is evaluated in patients with acute asthma attack. METHODS: In the present single-blind, randomized clinical trial with placebo control, the effect of low-dose intravenous ketamine in treating 18 to 85 year-old asthmatic patients who presented to the emergency department was evaluated. Peak expiratory flow rate (PEFR) and the patients' response to treatment were measured before and 1 hour after treatment. Additionally, using SPSS 22.0, effectiveness of ketamine with 0.3, 0.4, and 0.5 mg/kg doses followed by infusion of the same dose during 30 minutes were compared with placebo. RESULTS: 92 patients were enrolled (59.8% female, mean age 48.5 ± 13.9 years). 15 (16.3%) patients were treated with 0.3 mg/kg ketamine, 14 (15.2%) with 0.4 mg/kg, and 16 (17.4%) with 0.5 mg/kg doses. Mean PEFR was 336.2 ± 101.5 liters in the placebo group and 345.8 ± 84.7 liters in the ketamine group before intervention (p = 0.6), while after intervention, they were 352.1 ± 101.2 and 415.8 ± 76.2 liters, respectively (p = 0.001). Ketamine treatment with 0.4 and 0.5 mg/kg doses led to a higher increase in PEFR compared to 0.3mg/kg dose (df: 3, 88; F = 23.8; p < 0.001). CONCLUSION: It seems that administration of 0.4 - 0.5 mg/kg doses of intravenous ketamine followed by infusion of the same dose during 30 minutes can be effective for rapid recovery of PEFR in patients with mild to moderate asthma.

Aims: Previous studies have demonstrated that rapamycin prevents seizure-induced anxiety-like behaviors. However, rapamycin had been used at a higher dose of 3 mg/kg and resulted in side effects in immature animals. This work was designed to explore whether a lower dose of rapamycin has similar efficacy but has milder side effects.Methods: Acute seizures were induced by injection of pilocarpine at postnatal 10-day Sprague-Dawley rats. Western blot analysis was used to detect changes in mammalian target of rapamycin (mTOR) pathway after seizure. Immunofluorescent intensity of doublecortin (DCX) was conducted to evaluate the development of neurons in hippocampus. Morris water maze and Y-maze test were used to assess cognitive functions and open-field test and elevated plus maze were used to detect anxiety-like behaviors 4 weeks after seizure onset.Results: mTOR pathway was abnormally activated with two peaks after pilocarpine-induced seizures, and no difference of DCX-positive cells and body weight were noticed between control and pilocarpine-induced seizure rats. Pilocarpine-induced seizure in postnatal 10 days rats did not exert impairment on cognitive functions, but resulted in obvious anxiety-like behaviors. Low dose of rapamycin at 0.3 mg/kg significantly reversed seizure-induced increase of p-S6 levels as well as abnormal anxiety-like behaviors. In addition, rapamycin at the dose of 0.3mg/kg did not affect normal development and cognitive functions.Conclusion: lower doses of rapamycin should be used in infants compared with older children or adults.

INTRODUCTION: PPARβ/δ agonists are known to modulate the systemic inflammatory response after sepsis. In this study, inflammation modulation effects of PPARβ/δ are investigated using the selective PPARβ/δ agonist (GW0742) in a model of haemorrhagic shock (HS)-induced sterile systemic inflammation. METHODS: Blood pressure-controlled (35±5mmHg) HS was performed in C57/BL6 mice for 90min. Low-dose GW0742 (0.03mg/kg/BW) and high-dose GW0742 (0.3mg/kg/BW) were then administered at the beginning of resuscitation. Mice were sacrificed 6h after induction of HS. Plasma levels of IL-6, IL-1β, IL-10, TNFα, KC, MCP-1, and GM-CSF were determined by ELISA. Myeloperoxidase (MPO) activity in pulmonary and liver tissues was analysed with standardised MPO kits. RESULTS: In mice treated with high-dose GW0742, plasma levels of IL-6, IL-1β, and MCP-1 were significantly increased compared to the control group mice. When compared to mice treated with low-dose GW0742 plasma levels of IL-6, IL-1β, GM-CSF, KC, and MCP-1 were significantly elevated in high-dose-treated mice. Low-dose GW0742 treatment was associated with a non-significant downtrend of inflammatory factors in mice with HS. No significant changes of MPO activity in lung and liver were observed between the control group and the GW0742 treatment groups. CONCLUSION: This study identified dose-dependent effects of GW0742 on systemic inflammation after HS. While high-dose GW0742 substantially enhanced the systemic inflammatory response, low-dose GW0742 led to a downtrend of pro-inflammation cytokine expression. The exact mechanisms are yet unknown and need to be assessed in further studies.

Exposure to excessive or uncontrolled stress is a major factor associated with various diseases including posttraumatic stress disorder (PTSD). The consequences of exposure to trauma are affected not only by aspects of the event itself, but also by the frequency and severity of trauma reminders. It was suggested that in PTSD, hippocampal-dependent memory is compromised while amygdala-dependent memory is strengthened. Several lines of evidence support the role of the endocannabinoid (eCB) system as a modulator of the stress response. In this study we aimed to examine cannabinoids modulation of the long-term effects (i.e., 1 month) of exposure to a traumatic event on memory and plasticity in the hippocampus and amygdala. Following exposure to the shock and reminders model of PTSD in an inhibitory avoidance light-dark apparatus rats demonstrated: (i) enhanced fear retrieval and impaired inhibitory extinction (Ext), (ii) no long-term potentiation (LTP) in the CA1, (iii) impaired hippocampal-dependent short-term memory in the object location task, (iv) enhanced LTP in the amygdala, and (v) enhanced amygdala-dependent conditioned taste aversion memory. The cannabinoid CB1/2 receptor agonist WIN55-212,2 (0.5mg/kg, i.p.) and the fatty acid amide hydrolase (FAAH) inhibitor URB597 (0.3mg/kg, i.p.), administered 2 hr after shock exposure prevented these opposing effects on hippocampal- and amygdala-dependent processes. Moreover, the effects of WIN55-212,2 and URB597 on Ext and acoustic startle were prevented by co-administration of a low dose of the CB1 receptor antagonist AM251 (0.5mg/kg, i.p.), suggesting that the preventing effects of both drugs are mediated by CB1 receptors. Exposure to shock and reminders increased CB1 receptor levels in the CA1 and basolateral amygdala 1 month after shock exposure and this increase was also prevented by administering WIN55-212,2 or URB597. Taken together, these findings suggest the involvement of the eCB system, and specifically CB1 receptors, in the opposite effects of severe stress on memory and plasticity in the hippocampus and amygdala. © 2017 Wiley Periodicals, Inc.

Ongoing development of the dopamine system during adolescence may provide a partial mechanism for behavioral and psychiatric vulnerabilities. Despite early evidence for a hyperactive adolescent dopaminergic system, recent data suggest that adolescent dopamine may be functionally hypoactive compared to in adults. While this distinction has been established in response to dopaminergic drugs and natural rewards, little is known about age-related differences in cognitive efficacy of dopaminergic drugs. Using a recently established Cued Response Inhibition Task, we tested the effects of acute systemic methylphenidate, commonly known as Ritalin, on response inhibition and response initiation in adolescent and adults rats. First, we replicated previous data that adolescents are able to inhibit a response to a cue on par with adults, but are slower to produce a rewarded response after a stop cue. Next, we observed that methylphenidate modulated response inhibition in adult rats, with low dose (0.3mg/kg) improving inhibition, and high dose (3mg/kg) impairing performance. This dose-response pattern is commonly observed with psychostimulant cognitive modulation. In adolescents, however, methylphenidate had no effect on response inhibition at any dose. Latency of response initiation after the stop cue was not affected by methylphenidate in either adult or adolescent rats. These data establish that dose-response of a commonly prescribed psychostimulant medication is different in adolescents and adults. They further demonstrate that healthy adolescent response inhibition is not as sensitive to psychostimulants as in adults, supporting the idea that the dopamine system is hypoactive in adolescence. This article is part of a Special Issue entitled SI: Adolescent plasticity.

The neurodevelopmental fetal alcohol spectrum disorder (FASD) is characterized by cognitive and behavioral deficits in the offspring. Conferring the deficits to the next generation would increase overall FASD disease burden and prevention of this transmission could be highly significant. Prior studies showed the reversal of these behavioral deficits by low dose thyroxine (T4) supplementation to the ethanol-consuming mothers. Here we aim to identify whether prenatal ethanol (PE) exposure impairs hippocampus-dependent learning and memory in the second-generation (F2) progeny, and whether T4 administration to the ethanol-consuming dam can prevent it. Sprague-Dawley (S) dams received control diets (ad libitum and nutritional control) or ethanol containing liquid diet with and without simultaneous T4 (0.3mg/L diet) administration. Their offspring (SS F1) were mated with naive Brown Norway (B) males and females generating the SB F2 and BS F2 progeny. Hippocampus-dependent contextual fear memory and hippocampal expression of the thyroid hormone-regulated type 3 deiodinase, (Dio3) and neurogranin (Nrgn) were assessed. SS F1 PE-exposed females and their SB F2 progeny exhibited fear memory deficits. T4 administration to the mothers of F1 females reversed these deficits. Although SS F1 PE-exposed males also experienced fear memory deficit, this was neither transmitted to their BS F2 offspring nor reversed by prenatal T4 treatment. Hippocampal Dio3 and Nrgn expression showed similar pattern of changes. Grandmaternal ethanol consumption during pregnancy affects fear memory of the matrilineal second-generation progeny. Low dose T4 supplementation prevents this process likely via altering allele-specific and total expression of Dio3 in the hippocampus.

MCF-7 cells are a slow growing estrogen receptor (ER) positive human breast cancer cell line that is commonly used to model estrogen responsive breast cancer cell growth in-vitro and tumour growth in-vivo. These tumours require estrogen supplementation, and in-vivo doses of between 0.72mg and 2mg estradiol pellets are commonly implanted in the dorsal flank of ovariectomised, immunocompromised mice. We wanted to grow MCF-7 tumours in immunocompromised mice without the need to be ovariectomised. When we treated immunocompromised mice with 0.72mg pellets to induce MCF7 tumour growth, the mice developed urosepsis. We have now shown that lower doses of estradiol pellets, 0.3mg and 0.5mg, induce elevated serum estrogen levels and maintain tumour growth, without causing urosepsis. Supplementation for only one week did not support sustained MCF7 tumour growth. In conclusion, 0.3mg and 0.5mg silastic pellets can be used to stimulate ER+ breast cancer growth in ovary-intact, immune compromised mice.

The somatostatin analog pasireotide and the 11β-hydroxylase inhibitor osilodrostat (LCI699) reduce cortisol levels by distinct mechanisms of action. There exists a scientific rationale to investigate the clinical efficacy of these two agents in combination. This manuscript reports the results of a toxicology study in rats, evaluating different doses of osilodrostat and pasireotide alone and in combination. Sixty male and 60 female rats were randomized into single-sex groups to receive daily doses of pasireotide (0.3mg/kg/day, subcutaneously), osilodrostat (20mg/kg/day, orally), osilodrostat/pasireotide in combination (low dose, 1.5/0.03mg/kg/day; mid-dose, 5/0.1mg/kg/day; or high dose, 20/0.3mg/kg/day), or vehicle for 13weeks. Mean body-weight gains from baseline to Week 13 were significantly lower in the pasireotide-alone and combined-treatment groups compared to controls, and were significantly higher in female rats receiving osilodrostat monotherapy. Osilodrostat and pasireotide monotherapies were associated with significant changes in the histology and mean weights of the pituitary and adrenal glands, liver, and ovary/oviduct. Osilodrostat alone was associated with adrenocortical hypertrophy and hepatocellular hypertrophy. In combination, osilodrostat/pasireotide did not exacerbate any target organ changes and ameliorated the liver and adrenal gland changes observed with monotherapy. Cmax and AUC0-24h of osilodrostat and pasireotide increased in an approximately dose-proportional manner. In conclusion, the pasireotide and osilodrostat combination did not exacerbate changes in target organ weight or toxicity compared with either monotherapy, and had an acceptable safety profile; addition of pasireotide to the osilodrostat regimen may attenuate potential adrenal gland hyperactivation and hepatocellular hypertrophy, which are potential side effects of osilodrostat monotherapy.