Administration Of Dose Research Articles

Lack of Acute Agomelatine Effect in a Model of Social Anxiety in Healthy Volunteers: A Double-Blind, Placebo-Controlled Trial.

Agomelatine is an antidepressant drug that acts as an agonist of melatoninergic MT1/2 receptors and an antagonist of serotonergic 5-HT2C receptors. Studies suggest that agomelatine has anxiolytic properties in social anxiety, but there are no studies that assessed the effects of this compound in human experimental anxiety induced by a public speaking test. The objective of our investigation was to assess the effects of agomelatine on human experimental anxiety using the Simulation Public Speaking Test (SPST). Agomelatine (25 mg, n = 14), citalopram (20 mg, n = 14), venlafaxine (75 mg, n = 14), or placebo (n = 14) were administered in single doses to healthy volunteers in a double-blind study. Subjective anxiety was assessed with the Visual Analogue Mood Scale. Arterial blood pressure, heart rate, and blood levels of prolactin and cortisol were also recorded, as well as plasma levels of the 3 drugs. The SPST induced significant subjective, physiological, and hormonal effects in all groups. The SPST also increased the anxiety and decreased mental sedation Visual Analogue Mood Scale factors during the anticipatory and performance phases of the test. Citalopram increased anxiety during the test in females, whereas agomelatine and venlafaxine were not different from placebo. Confirming previous results, a serotonin selective reuptake inhibitor, citalopram, caused an anxiogenic effect in the SPST only in females. Acute administration of a low dose of agomelatine failed to modify the behavioral and physiological changes caused by this test. Future studies using higher doses and repeated administration should investigate if agomelatine behavioral and physiological effects could be detected in human experimental anxiety models.

Early Detection and Management of Lamanema chavezi infection in a llama (Lama glama) in Switzerland.

Lamanema chaveziis an entero-hepatic strongylid parasite specific to South American camelids. It has been reported only on few occasions outside South America. Due to its hepaticmigration, it can cause extensive liver damage, leading to granulomatous and fibrotic hepatitis and manifesting with lethargy, anorexia, and even death. We are reporting the second case ofL. chavezi infection in Europe and the first in Switzerland. The patient was a three-year old neutered male llama (Lama glama). Clinical examination revealed bloody mucous discharge from the anus. Fecal sedimentation/flotation revealed strongylid eggs consistent with L. chavezi, which were molecularly confirmed by a PCR targeting the ITS2 plus 5.8S and 28S rDNA flanking regions and amplicon sequencing. Eighteen weeks after administration of a single dose of eprinomectin (0.2mg/kg i.m.), no further L. chavezi eggs were detected in the feces. The source of infection could not be traced back. The entire herd consisted of llamas bred in Switzerland. L. chavezi has been rarely reported outside South America, but its potential for pathogenicity and establishment should not be underestimated. Fecal sedimentation/flotation techniques should be routinely performed to ensure early detection of the parasite.

The effect of carbohydrate adjuvants in the composition of the experimental hantavirus vaccine on the dynamics of neutralizing antibodies in the blood sera of guinea pigs

Introduction. Vaccination could be the most effective means of preventing hemorrhagic fever with renal syndrome (HFRS), which is one of the leading zoonoses and a major cause of natural disease in humans. Therefore, research to develop an effective vaccine and the search for new non-toxic and effective adjuvants that can enhance and prolong the immune response, reduce the antigen concentration and reduce the frequency of dose administration is an urgent task. The aim of the study was to determine the dependence of the immunogenic activity of an experimental hantavirus vaccine based on Puumala virus (HV) on the antigen dose both in native form and in combination with carbohydrate adjuvants. Materials and methods. The immunoadjuvant effect of Ac3-LPS S. sonnei and S. flexneri 1B and emulsions of nanoemulsified squalene Sepivac SWE (SWE) as part of HV at the optimal and minimal doses was investigated by induction of neutralising antibodies after 3-fold immunisation (day 0, 14, 182) of guinea pigs (Cavia porcellus). Differences in the immunogenic activity of HV were assessed in the neutralisation reaction by 50% suppression of focal units in Vero E6 cell cultures. Results. A statistically significant increase in neutralising antibodies levels was observed after immunization both with HV at the optimal dose and for its combination with adjuvants. Ac3-LPS S. sonnei and SWE showed the most pronounced immunoadjuvant effect at concentrations of 50 and 100 μg/dose, respectively. The immunoadjuvant effect of the combination of the hantavirus vaccine with Ac3-LPS S. sonnei and SWE contributed to both an enhanced immune response and its duration. The tenfold reduction of the antigen dose in the presence of SWE allows optimization of the immune response to the vaccine. Conclusion. The results of this study show the prospects of using Ac3-LPS S. sonnei and Sepivac SWE in the vaccine for the prevention of HFRS.

Construction of GSH-responsive polyethyleneimine-based delivery vector for effective gene transfection.

The rise of gene therapy has solved many diseases that cannot be effectively treated by conventional methods. Gene vectors is very important to protect and deliver the therapeutic genes to the target site. Polyethyleneimine (PEI) modified with mannitol could enhance the gene transfection efficiency reported by our group previously. In order to further control and improve the effective gene release to action site, disulfide bonds were introduced into mannitol-modified PEI to construct new non-viral gene vectors PeiSM. The degrees of mannitol linking with disulfide bonds were screened. Among them, moderate mannitol-modified polyethyleneimine with disulfide bonds (M-PeiSM) showed the best transfection efficiency, and significantly enhanced long-term systemic transgene expression for 72 hours in vivo even at a single dose administration, and could promote caveolae-mediated uptake through up-regulating the phosphorylation of caveolin-1 and increase the loaded gene release from the nanocomplexes in high GSH intracellular environment. This functionalized gene delivery system can be used as an potential and safe non-viral nanovector for further gene therapy.

Impact of COVID-19 vaccines in patients on hemodialysis: an Italian multicentre cohort study.

The aim of this study was to evaluate the impact on the national health system of COVID-19 infection in vaccinated patients undergoing haemodialysis. From the cohort of vaccinated dialysis patients enrolled in 118 dialysis centres, we calculated hospitalisation incidence in COVID-19-infected subjects. COVID-19-related hospitalisations and ICU admissions were analysed over two time periods (prior to administration of the third dose and following administration of the third dose of vaccine) and adjusted for several co-variates. Using the general population as the reference, we then calculated the Standardized Incidence Ratio (SIR) of hospitalisation. Eighty-two subjects out of 1096 infected patients were hospitalised (7.5%) and sixty-four hospitalisations occurred among the 824 infected persons after the third dose. Age ≥ 60years (Adj RR 2.91; 95% CI 1.34-6.30) and lung disease (Adj RR = 2.45; 95% CI 1.32-4.54) were the only risk factors associated with hospitalisation. The risk of ICU admission in the second time period (Time 2) was reduced by 86% (RR = 0.14; 95% CI 0.03-0.71) compared to the first time period (Time 1). The SIR of hospitalisation (SIR 14.51; 95% CI 11.37-17.65) and ICU admission (SIR 14.58; 95% CI 2.91-26.24) showed an increase in the number of events in dialysis patients compared to the general population. Our analysis revealed that while the second variant of the virus increased infection rates, it wasconcurrently associated withmitigated severity of infections. Dialysis patients exhibited a higher susceptibility to both COVID-19 hospitalisation and ICU admission than the general population throughout the pandemic.

The effect of single low-dose primaquine treatment for uncomplicated Plasmodium falciparum malaria on haemoglobin levels in Ethiopia: a longitudinal cohort study

BackgroundTo interrupt residual malaria transmission and achieve successful elimination of Plasmodium falciparum in low-transmission settings, the World Health Organization (WHO) recommends the administration of a single dose of 0.25 mg/kg (or 15 mg/kg for adults) primaquine (PQ) combined with artemisinin-based combination therapy (ACT), without glucose-6-phosphate dehydrogenase (G6PD) testing. However, due to the risk of haemolysis in patients with G6PD deficiency (G6PDd), PQ use is uncommon. Thus, this study aimed to assess the safety of a single low dose of PQ administered to patients with G6PD deficiency.MethodsAn observational cohort study was conducted with patients treated for uncomplicated P. falciparum malaria with either single-dose PQ (0.25 mg/kg) (SLD PQ) + ACT or ACT alone. Microscopy-confirmed uncomplicated P. falciparum malaria patients visiting public health facilities in Arjo Didessa, Southwest Ethiopia, were enrolled in the study from September 2019 to November 2022. Patients with uncomplicated P. falciparum malaria were followed up for 28 days through clinical and laboratory diagnosis, such as measurements of G6PD levels and haemoglobin (Hb) concentrations. G6PD levels were measured by a quantiative CareSTART™ POCT S1 biosensor machine. Patient interviews were also conducted, and the type and frequency of clinical complaints were recorded. Hb data were taken on days (D) 7, 14, 21, and 28 following treatment with SLD-PQ + ACT or ACT alone.ResultsA total of 249 patients with uncomplicated P. falciparum malaria were enrolled in this study. Of these, 83 (33.3%) patients received ACT alone, and 166 (66.7%) received ACT combined with SLD-PQ treatment. The median age of the patients was 20 (IQR 28–15) years. G6PD deficiency was found in 17 (6.8%) patients, 14 males and 3 females. There were 6 (7.2%) and 11 (6.6%) phenotypic G6PD-deficient patients in the ACT alone and ACT + SLD-PQ arms, respectively. The mean Hb levels in patients treated with ACT + SLD-PQ were reduced by an average of 0.45 g/dl (95% CI = 0.39 to 0.52) in the posttreatment phase (D7) compared to a reduction of 0.30 g/dl (95% CI = 0.14 to − 0.47) in patients treated with ACT alone (P = 0.157). A greater mean Hb reduction was observed on day 7 in the G6PDd ACT + SLD-PQ group (− 0.60 g/dL) than in the G6PDd ACT alone group (− 0.48 g/dL); however, there was no statistically significant difference (P = 0.465). Overall, D14 losses were 0.10 g/dl (95% CI = − 0.00 to 0.20) and 0.05 g/dl (95% CI = − 0.123 to 0.22) in patients with and without SLD-PQ, respectively (P = 0.412).ConclusionsThis study’s findings indicate that using SLD-PQ in combination with ACT is safe for uncomplicated P. falciparum malaria regardless of the patient's G6PD status in Ethiopian settings. Caution should be taken in extrapolating this finding in other settings with diverse G6DP phenotypes.

Food Effect and Pharmacokinetic Bridging of Avacopan in Caucasian and Japanese Healthy Participants.

Avacopan 30mg twice daily (BID) is approved for the treatment of severe active antineutrophil cytoplasmic autoantibody-associated vasculitis (granulomatosis with polyangiitis and microscopic polyangiitis). Food effect on avacopan pharmacokinetics (PKs) and PK bridging in Japanese participants were examined through 2 phase 1 studies involving healthy adult participants. In Study 1, an open-label, crossover trial, participants received oral administration of a single 30-mg dose of avacopan under fasted and fed conditions. Study 2 was a randomized, single-blind, placebo-controlled trial in Caucasian and Japanese participants: Part A investigated single doses of 10 and 30mg of avacopan under fasted and fed conditions and Part B investigated 30 and 50mg BID avacopan. The PKs of single-dose administrations of 10 and 30mg in Japanese participants was compared with that in Caucasian participants under fasted conditions. Food substantially increased plasma avacopan area under the plasma concentration-time curve from time 0 to time infinity (AUC0-inf) by 1.72-fold, supporting the recommendation of taking avacopan with food. Maximum plasma concentration (Cmax) remained relatively unchanged. The median time to reach Cmax (tmax) was delayed by 3hours. No significant food effect was observed on the active metabolite CCX168-M1 (M1) AUC. Avacopan and M1 exposures were <1.5-fold higher in Japanese participants than in Caucasian participants following multiple-dose administration of avacopan.

Effects of Denosumab and Bisphosphonates on Glucocorticoid-induced Osteoporosis in Patients with Neuroimmunological Disorders.

Objective Although patients with neuroimmunological disorders often need to be treated with glucocorticoids and are at risk of developing glucocorticoid-induced osteoporosis, no research has focused on the treatment of glucocorticoid-induced osteoporosis in such patients. Methods We compared the efficacy of denosumab and bisphosphonates in glucocorticoid-induced osteoporosis in neuroimmunological diseases. In 57 patients with neuroimmunological disorders treated with corticosteroids (34 with neuromyelitis optica spectrum disorders, 16 with myasthenia gravis, and 7 with others), we retrospectively studied the long-term effects of denosumab (n=23) and bisphosphonates (n=34) on spine and total hip bone mineral density (BMD) measured by dual energy X-ray absorptiometry. Results There were no significant differences in the age, lumbar spine BMD, or mean dose or duration of prednisolone administration at baseline between the denosumab and bisphosphonate groups. During the follow-up period of up to 6 years, the increase in the lumbar spine and total hip BMD was greater in the denosumab group than in the bisphosphonate group (p<0.01). Insufficient bone fractures were observed in 2 (9%) of the 23 patients in the denosumab group and in 2 (6%) of the 34 patients in the bisphosphonate group (not significant). Conclusion Denosumab is more effective than bisphosphonates in increasing the BMD of patients with neuroimmunological disorders receiving glucocorticoids.

Model-Informed Reinforcement Learning for Enabling Precision Dosing Via Adaptive Dosing.

Precision dosing, the tailoring of drug doses to optimize therapeutic benefits andminimize risks in each patient, is essential for drugs with a narrow therapeutic window and severe adverse effects. Adaptive dosing strategies extend the precision dosing concept to time-varying treatments which require sequential dose adjustments based on evolving patient conditions. Reinforcement learning (RL) naturally fits this paradigm: it perfectly mimics the sequential decision-making process where clinicians adapt dose administration based on patient response and evolution monitoring. This paper aims to investigate the potentiality of coupling RL with population PK/PD models to develop precision dosing algorithms, reviewing the most relevant works in the field. Case studies in which PK/PD models were integrated within RL algorithms as simulation engine to predict consequences of any dosing action have been considered and discussed. They mainly concern propofol-induced anesthesia, anticoagulant therapy with warfarin and a variety of anticancer treatments differing for administered agents and/or monitored biomarkers. The resulted picture highlights a certain heterogeneity in terms of precision dosing approaches, applied methodologies, and degree of adherence to the clinical domain. In addition, a tutorial on how a precision dosing problem should be formulated in terms of the key elements composing the RL framework (i.e., system state, agent actions and reward function), and on how PK/PD models could enhance RL approaches is proposed for readers interested in delving in this field. Overall, the integration of PK/PD models into a RL-framework holds great promise for precision dosing, but further investigations and advancements are still needed to address current limitations and extend the applicability of this methodology to drugs requiring adaptive dosing strategies.

A Case Report on Granulomatosis with Polyangitis and Diffuse Alveolar Haemorrhage

Granulomatous polyangitis (GPA), formerly known as Wegener’s granulomatosis, is a rare form of small-vessel vasculitis. It has no gender predominance and tends to present between the ages of 40 and 55 years old in more than two-thirds of cases. GPA should be critically considered as a diagnosis when a presentation involves multiple systems, including joint, kidney, and lung. Lifesaving treatment of GPA is based on prompt and aggressive administration of pulse steroids and high doses of cyclophosphamide in repeat intervals.

The future of cancer treatment: combining radiotherapy with immunotherapy

Radiotherapy (RT) and immunotherapy (IT) are the powerful tools for cancer treatment which act through the stimulation of immune response, and evidence suggest that combinatorial actions of these therapies may augment each other’s beneficial effect through complex synergistic mechanisms. These molecular strategies are designed to target rapidly dividing cancer cells by either directly or indirectly inducing DNA damage. However, when cells detect DNA damage, they activate a range of signalling pathways known as the DNA damage response (DDR) to repair. Strategies are being developed to interfere with the DDR pathways in cancer cells to ensure their damage-induced degeneration. The stability of a cell’s genetic material is largely dependent on the efficacy of DNA repair and therefore, an in-depth understanding of DNA damages and repair mechanism(s) in cancer cells is important to develop a promising therapeutic strategies for ensuring the efficacy of damage-induced tumor cell death. In recent years, a wide range of small molecule drugs have been developed which are currently being employed to combat the DNA repair deficiencies associated with tumor cells. Sequential or concurrent use of these two modalities significantly enhances the anti-tumor response, however with a concurrent probability of increased incidence of symptomatic adverse effects. With advent of newer IT agents, and administration of higher doses of radiation per fraction, such effects are more difficult to predict owing to the paucity of randomized trial data. It is well established that anti cytotoxic-T-lymphocyte-associated antigen 4 (CTLA-4), anti- Programmed cell death protein 1(PD-1), anti-Programmed cell death one ligand 1 (PD-L1) can be safely administered with RT and many studies have demonstrated survival benefit with such combination for patients with metastatic malignancy. However, the biology of radioimmunotherapy (RT/IT) is still an open area where research need to be focused to determine optimum dosage specially the interaction of the RT/IT pathways to determine optimum dosing schedule. In the current article we have summarised the possible intracellular immunological events that might be triggered when RT and IT modalities are combined with the DDR antagonists and highlighted present clinical practices, outcome, and toxicity profile of this novel treatment strategy.

The future of cancer treatment: combining radiotherapy with immunotherapy

Radiotherapy (RT) and immunotherapy (IT) are the powerful tools for cancer treatment which act through the stimulation of immune response, and evidence suggest that combinatorial actions of these therapies may augment each other’s beneficial effect through complex synergistic mechanisms. These molecular strategies are designed to target rapidly dividing cancer cells by either directly or indirectly inducing DNA damage. However, when cells detect DNA damage, they activate a range of signalling pathways known as the DNA damage response (DDR) to repair. Strategies are being developed to interfere with the DDR pathways in cancer cells to ensure their damage-induced degeneration. The stability of a cell’s genetic material is largely dependent on the efficacy of DNA repair and therefore, an in-depth understanding of DNA damages and repair mechanism(s) in cancer cells is important to develop a promising therapeutic strategies for ensuring the efficacy of damage-induced tumor cell death. In recent years, a wide range of small molecule drugs have been developed which are currently being employed to combat the DNA repair deficiencies associated with tumor cells. Sequential or concurrent use of these two modalities significantly enhances the anti-tumor response, however with a concurrent probability of increased incidence of symptomatic adverse effects. With advent of newer IT agents, and administration of higher doses of radiation per fraction, such effects are more difficult to predict owing to the paucity of randomized trial data. It is well established that anti cytotoxic-T-lymphocyte-associated antigen 4 (CTLA-4), anti- Programmed cell death protein 1(PD-1), anti-Programmed cell death one ligand 1 (PD-L1) can be safely administered with RT and many studies have demonstrated survival benefit with such combination for patients with metastatic malignancy. However, the biology of radioimmunotherapy (RT/IT) is still an open area where research need to be focused to determine optimum dosage specially the interaction of the RT/IT pathways to determine optimum dosing schedule. In the current article we have summarised the possible intracellular immunological events that might be triggered when RT and IT modalities are combined with the DDR antagonists and highlighted present clinical practices, outcome, and toxicity profile of this novel treatment strategy.

Evaluation of the Antioxidant and Anti-Inflammatory Activities and Acute Toxicity of Caco Seed (Chrysobalanus icaco L.) in Murine Models

Chysobalanus icaco L. (C. icaco) is a plant that is native to tropical America and Africa. It is also found in the southeast region of Mexico, where it is used as food and to treat certain diseases. This study aimed to carry out a phytochemical analysis of an aqueous extract of C. icaco seed (AECS), including its total phenol content (TPC), total flavonoid content (TFC), and condensed tannins (CT). It also aimed to examine the antioxidant and metal-ion-reducing potential of the AECS in vitro, as well as its toxicity and anti-inflammatory effect in mice. Antioxidant and metal-ion-reducing potential was examined by inhibiting DPPH, ABTS, and FRAP. The acute toxicity test involved a single administration of different doses of the AECS (0.5, 1, and 2 g/kg body weight). Finally, a single administration at doses of 150, 300, and 600 mg/kg of the AECS was used in the carrageenan-induced model of subplantar acute edema. The results showed that the AECS contained 124.14 ± 0.32 mg GAE, 1.65 ± 0.02 mg EQ, and 0.910 ± 0.01 mg of catechin equivalents/g dried extract (mg EC/g de extract) for TPC, TFC and CT, respectively. In the antioxidant potential assays, the values of the median inhibition concentration (IC50) of the AECS were determined with DPPH (0.050 mg/mL), ABTS (0.074 mg/mL), and FRAP (0.49 mg/mL). Acute toxicity testing of the AECS revealed no lethality, with a median lethal dose (LD50) value of &gt;2 g/kg by the intragastric route. Finally, for inhibition of acute edema, the AECS decreased inflammation by 55%, similar to indomethacin (59%, p &gt; 0.05). These results demonstrated that C. icaco seed could be considered a source of bioactive molecules for therapeutic purposes due to its antioxidant potential and anti-inflammatory activity derived from TPC, with no lethal effect from a single intragastric administration in mice.

Evaluation of the Antioxidant and Anti-Inflammatory Activities and Acute Toxicity of Caco Seed (Chrysobalanus icaco L.) in Murine Models

Chysobalanus icaco L. (C. icaco) is a plant that is native to tropical America and Africa. It is also found in the southeast region of Mexico, where it is used as food and to treat certain diseases. This study aimed to carry out a phytochemical analysis of an aqueous extract of C. icaco seed (AECS), including its total phenol content (TPC), total flavonoid content (TFC), and condensed tannins (CT). It also aimed to examine the antioxidant and metal-ion-reducing potential of the AECS in vitro, as well as its toxicity and anti-inflammatory effect in mice. Antioxidant and metal-ion-reducing potential was examined by inhibiting DPPH, ABTS, and FRAP. The acute toxicity test involved a single administration of different doses of the AECS (0.5, 1, and 2 g/kg body weight). Finally, a single administration at doses of 150, 300, and 600 mg/kg of the AECS was used in the carrageenan-induced model of subplantar acute edema. The results showed that the AECS contained 124.14 ± 0.32 mg GAE, 1.65 ± 0.02 mg EQ, and 0.910 ± 0.01 mg of catechin equivalents/g dried extract (mg EC/g de extract) for TPC, TFC and CT, respectively. In the antioxidant potential assays, the values of the median inhibition concentration (IC50) of the AECS were determined with DPPH (0.050 mg/mL), ABTS (0.074 mg/mL), and FRAP (0.49 mg/mL). Acute toxicity testing of the AECS revealed no lethality, with a median lethal dose (LD50) value of &gt;2 g/kg by the intragastric route. Finally, for inhibition of acute edema, the AECS decreased inflammation by 55%, similar to indomethacin (59%, p &gt; 0.05). These results demonstrated that C. icaco seed could be considered a source of bioactive molecules for therapeutic purposes due to its antioxidant potential and anti-inflammatory activity derived from TPC, with no lethal effect from a single intragastric administration in mice.

The effectiveness of the lorazepam challenge test in pediatric catatonia: A multisite retrospective cohort study

ObjectiveCatatonia is a neuropsychiatric disorder associated with changes in behavior and affect. In adults, catatonia can respond rapidly to treatment with benzodiazepines as part of the “lorazepam challenge test.” The acute effectiveness of benzodiazepine treatment in pediatric catatonia, however, has received less study. This study reports catatonia severity as measured by the Bush Francis Catatonia Rating Scale (BFCRS) in pediatric patients before and after treatment with lorazepam. MethodsMulticenter retrospective cohort study from 1/1/2018 to 6/1/2023 of patients aged 18 and younger with a clinical diagnosis of catatonia and assessment using the BFCRS before and after treatment with lorazepam. ResultsAmong 54 patients, median age was 16, and 26 (48.1 %) were female. Neurodevelopmental disabilities were present in 24 (44.4 %) of patients. Prior to treatment, patients had a mean BFCRS score of 16.6 ± 6.1, which significantly reduced to 9.5 ± 5.3 following treatment with lorazepam (mean paired difference 7.1; t = 9.0, df = 53, p < 0.001), representing a large effect size (Hedges's g = 1.20; 95 % CI: 0.85 to 1.55). No significant association was found between lorazepam dose or route of administration and clinical response, nor were age, sex, study site, the presence of a neurodevelopmental disorder, the presence of hyperactive catatonic features, or the time between treatment and reassessment associated with post-treatment BFCRS. ConclusionsLorazepam resulted in a rapid improvement in BFCRS score in pediatric patients, with a large effect size. Further research is needed into optimal dosing and route of administration of the lorazepam challenge test in pediatric patients.

A quantitative modeling framework to understand the physiology of the hypothalamic-pituitary-adrenal axis and interaction with cortisol replacement therapy.

Congenital adrenal hyperplasia (CAH) is characterized by impaired adrenal cortisol production. Hydrocortisone (synthetic cortisol) is the drug-of-choice for cortisol replacement therapy, aiming to mimic physiological cortisol circadian rhythm. The hypothalamic-pituitary-adrenal (HPA) axis controls cortisol production through the pituitary adrenocorticotropic hormone (ACTH) and feedback mechanisms. The aim of this study was to quantify key mechanisms involved in the HPA axis activity regulation and their interaction with hydrocortisone therapy. Data from 30 healthy volunteers was leveraged: Endogenous ACTH and cortisol concentrations without any intervention as well as cortisol concentrations measured after dexamethasone suppression and single dose administration of (i) 0.5-10mg hydrocortisone as granules, (ii) 20mg hydrocortisone as granules and intravenous bolus. A stepwise model development workflow was used: A newly developed model for endogenous ACTH and cortisol was merged with a refined hydrocortisone pharmacokinetic model. The joint model was used to simulate ACTH and cortisol trajectories in CAH patients with varying degrees of enzyme deficiency, with or without hydrocortisone administration, and healthy individuals. Time-dependent ACTH-driven endogenous cortisol production and cortisol-mediated feedback inhibition of ACTH secretion processes were quantified and implemented in the model. Comparison of simulated ACTH and cortisol trajectories between CAH patients and healthy individuals showed the importance of administering hydrocortisone before morning ACTH secretion peak time to suppress ACTH overproduction observed in untreated CAH patients. The developed framework allowed to gain insights on the physiological mechanisms of the HPA axis regulation, its perturbations in CAH and interaction with hydrocortisone administration, paving the way towards cortisol replacement therapy optimization.

A quantitative modeling framework to understand the physiology of the hypothalamic-pituitary-adrenal axis and interaction with cortisol replacement therapy.

Congenital adrenal hyperplasia (CAH) is characterized by impaired adrenal cortisol production. Hydrocortisone (synthetic cortisol) is the drug-of-choice for cortisol replacement therapy, aiming to mimic physiological cortisol circadian rhythm. The hypothalamic-pituitary-adrenal (HPA) axis controls cortisol production through the pituitary adrenocorticotropic hormone (ACTH) and feedback mechanisms. The aim of this study was to quantify key mechanisms involved in the HPA axis activity regulation and their interaction with hydrocortisone therapy. Data from 30 healthy volunteers was leveraged: Endogenous ACTH and cortisol concentrations without any intervention as well as cortisol concentrations measured after dexamethasone suppression and single dose administration of (i) 0.5-10mg hydrocortisone as granules, (ii) 20mg hydrocortisone as granules and intravenous bolus. A stepwise model development workflow was used: A newly developed model for endogenous ACTH and cortisol was merged with a refined hydrocortisone pharmacokinetic model. The joint model was used to simulate ACTH and cortisol trajectories in CAH patients with varying degrees of enzyme deficiency, with or without hydrocortisone administration, and healthy individuals. Time-dependent ACTH-driven endogenous cortisol production and cortisol-mediated feedback inhibition of ACTH secretion processes were quantified and implemented in the model. Comparison of simulated ACTH and cortisol trajectories between CAH patients and healthy individuals showed the importance of administering hydrocortisone before morning ACTH secretion peak time to suppress ACTH overproduction observed in untreated CAH patients. The developed framework allowed to gain insights on the physiological mechanisms of the HPA axis regulation, its perturbations in CAH and interaction with hydrocortisone administration, paving the way towards cortisol replacement therapy optimization.

Enhanced radiotheranostic targeting of integrin α5β1 with PEGylation-enabled peptide multidisplay (PEGibody): A strategy for prolonged tumor retention with fast blood clearance

Peptide-based radiopharmaceuticals targeting integrin α5β1 show promise for precise tumor diagnosis and treatment. However, current peptide-based radioligands that target α5β1 demonstrate inadequate in vivo performance owing to limited tumor retention. The use of PEGylation to enhance the tumor retention of radiopharmaceuticals by prolonging blood circulation time poses a risk of increased blood toxicity. Therefore, a PEGylation strategy that boosts tumor retention while minimizing blood circulation time is urgently needed. Here, we developed a PEGylation-enabled peptide multidisplay platform (PEGibody) for PR_b, an α5β1 targeting peptide. PEGibody generation involved PEGylation and self-assembly. [64Cu]QM-2303 PEGibody displayed spherical nanoparticles ranging from 100 to 200 nm in diameter. Compared with non-PEGylated radioligands, [64Cu]QM-2303 demonstrated enhanced tumor retention time due to increased binding affinity and stability. Importantly, the biodistribution analysis confirmed rapid clearance of [64Cu]QM-2303 from the bloodstream. Administration of a single dose of [177Lu]QM-2303 led to robust antitumor efficacy. Furthermore, [64Cu]/[177Lu]QM-2303 exhibited low hematological and organ toxicity in both healthy and tumor-bearing mice. Therefore, this study presents a PEGibody-based radiotheranostic approach that enhances tumor retention time and provides long-lasting antitumor effects without prolonging blood circulation lifetime. The PEGibody-based radiopharmaceutical [64Cu]/[177Lu]QM-2303 shows great potential for positron emission tomography imaging-guided targeted radionuclide therapy for α5β1-overexpressing tumors.

Effect of kynurenic acid on enzymatic activity of the DNA base excision repair pathway in specific areas of the sheep brain

Relatively low levels of antioxidant enzymes coupled with high oxygen metabolism result in the formation of numerous oxidative DNA damages in the tissues of the central nervous system. Recently, kynurenic acid (KYNA), knowns for its neuroprotective properties, has gained increasing attention in this context. Therefore, our hypothesis assumed that increased KYNA levels in the brain would positively influence mRNA expression of selected enzymes of the base excision repair pathway as well as enhance their efficiency in excising damaged nucleobases in specific areas of the sheep brain. The study was conducted on adult anestrous sheep (n = 18), in which two different doses of KYNA (20 and 100 μg/day) were infused into the third brain ventricle for three days. Molecular and biochemical analysis included the hypothalamus (preoptic and mediol-basal areas), hippocampus (CA3 field) and amygdala (central amygdaloid nucleus), dissected from the brain of sheep euthanized immediately after the last infusion. The results revealed a significant increase P < 0.001) in the relative mRNA abundance of N-methylpurine DNA glycosylase (MPG) following administration of both dose of KYNA across all examined tissues. The transcription of thymine-DNA glycosylase (TDG) increased significantly (P < 0.001) in all tissues in response to the lower KYNA dose compared to the control group. Moreover, 8-oxoguanine (8-oxoG) DNA glycosylase (OGG1) mRNA levels were also higher in both animal groups (P < 0.001). In addition, in the hypothalamus, hippocampus and amygdala, AP endonuclease 1 (APE1) mRNA expression increased under both doses of KYNA. Moreover, the both dose of KYNA significantly stimulated the efficiency of 8-oxoG excision in hypothalamus and amygdala (P < 0.05–0.001). The lower and higher doses of KYNA significantly influenced the effectiveness of εA and εC in all structures (P < 0.01–0.001). In conclusion, the favorable effect of KYNA in the brain may include the protection of genetic material in nerve and glial cells by stimulating the expression and efficiency of BER pathway enzymes.

Adipose mesenchymal stem cells-derived extracellular vesicles exert their preferential action in damaged central sites of SOD1 mice rather than peripherally.

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disorder involving motor neuron (MN) loss in the motor cortex, brainstem and spinal cord leading to progressive paralysis and death. Due to the pathogenetic complexity, there are no effective therapies available. In this context the use of mesenchymal stem cells and their vesicular counterpart is an emerging therapeutic strategy to counteract neurodegeneration. The extracellular vesicles derived from adipose stem cells (ASC-EVs) recapitulate and ameliorate the neuroprotective effect of stem cells and, thanks to their small dimensions, makes their use suitable to develop novel therapeutic approaches for neurodegenerative diseases as ALS. Here we investigate a therapeutic regimen of ASC-EVs injection in SOD1(G93A) mice, the most widely used murine model of ALS. Repeated intranasal administrations of high doses of ASC-EVs were able to ameliorate motor performance of injected SOD1(G93A) mice at the early stage of the disease and produce a significant improvement at the end-stage in the lumbar MNs rescue. Moreover, ASC-EVs preserve the structure of neuromuscular junction without counteracting the muscle atrophy. The results indicate that the intranasal ASC-EVs administration acts in central nervous system sites rather than at peripheral level in SOD1(G93A) mice. These considerations allow us to identify future applications of ASC-EVs that involve different targets simultaneously to maximize the clinical and neuropathological outcomes in ALS in vivo models.