Different Mechanisms Of Action Research Articles

Prefrontal cortex engagement during an fMRI task of emotion regulation as a potential predictor of treatment response in borderline personality disorder.

Borderline personality disorder (BPD) is a severe mental illness, with high rates of co-morbid depression and suicidality. Despite the importance of optimizing treatment in BPD, little is known about how neural processes relate to individual treatment response. This study examines how baseline regional brain blood oxygen level dependent (BOLD) activation during a functional magnetic resonance imaging (fMRI) task of emotion regulation is related to treatment response following a six-month randomized clinical trial of Dialectical Behavior Therapy (DBT) or Selective Serotonin Reuptake Inhibitor (SSRI) treatment. Unmedicated females with BPD (N = 37), with recent suicidal behavior or self-injury, underwent an fMRI task in which negative personal memories were presented and they were asked to distance (i.e., downregulate their emotional response) or immerse (i.e., experience emotions freely). Patients were then randomized to DBT (N = 16) or SSRI (N = 21) treatment, with baseline and post-treatment depression and BPD severity assessed. BOLD activity in prefrontal cortex, anterior cingulate, and insula was associated with distancing. Baseline BOLD during distancing in dorsolateral, ventrolateral, and orbital prefrontal cortex (dlPFC, vlPFC, OFC) differentially predicted depression response across treatment groups, with higher activity predicting better response in the SSRI group, and lower activity predicting better response in the DBT group. All female samples. Findings indicate that greater prefrontal engagement during emotion regulation may predict more antidepressant benefit from SSRIs, whereas lower engagement may predict better response to DBT. These results suggest different mechanisms of action for SSRI and DBT treatment, and this may allow fMRI to guide individualized treatment selection.

Beneficial effects of resveratrol on diabetes mellitus and its complications: focus on mechanisms of action.

Diabetes mellitus (DM) is a significant global health issue, associated with various microvascular and macrovascular complications that significantly impair patients' quality of lifeas well as healthspan and lifespan. Despite the availability of several anti-diabetic medications with different mechanisms of action, there remains no definite curative treatment. Hence, discovering new efficient complementarytherapies is essential. Natural products have received significant attention due to their advantages in various pathological conditions. Resveratrol is a natural polyphenol that possesses antioxidant and anti-inflammatory properties, and its efficacy has been previously investigated in several diseases, including DM. Herein, we aimed to provide a holistic view of the signaling pathways and mechanisms of action through which resveratrol exerts its effects against DM and its complications.

Cycling versus swapping strategies with TNF-α inhibitors and IL-17 inhibitors in psoriatic arthritis in clinical practice

The availability of a number of bDMARDs with different mechanism of action increases potential treatment pathways in psoriatic arthritis (PsA). In clinical practice, following the failure of one bDMARD, it is normal to consider which options are the best for switching strategy. In most cases this choice involves IL17i and TNFi. The main aim of this study was to compare the effectiveness of cycling (from TNFi to another TNFi) and swapping (from TNFi to IL17i or vice versa) strategies. In this monocentric retrospective observational study, all PsA patients treated with TNFi or IL17i between January 2016 and January 2022 were enrolled. The prescriptions were clustered in one cycling group (CG), and two swap groups: from TNFi to IL17i (SG1) and from IL17i to TNFi (SG2). The Kaplan–Meier method and Cox regression models were applied to compare the drug retention rates and to identify factors affecting treatment persistence. A total of 122 patients were enrolled. The CG, SG1 and SG2 2-years retention rates were 51%, 58% and 34% (p = 0.1), respectively. SG1 strategy (HR 0.53; CI 0.31–0.89; p = 0.02), age (HR 0.98; CI 0.96–0.99; p = 0.003), Disease Activity PsA (HR 1.11; CI 1.08–1.13; p < 0.0001), year of switch (HR 1.78; CI 1.39–2.22; p < 0.0001) influenced the retention rate. The findings of this real-world study, even if burdened by bias related to its observational nature, support the hypothesis that in PsA patients swapping from TNFi to IL17i might be more effective than cycling TNFis.

Formulation of Thermo-Sensitive In Situ Gels Loaded with Dual Spectrum Antibiotics of Azithromycin and Ofloxacin

In situ gels have been developed as an innovative strategy to prolong corneal residence time and enhance drug absorption compared to traditional eye drops. Our study aimed to formulate an ophthalmic in situ gel with a combination of two thermosensitive poloxamers, P407 and P188, in an optimal ratio not only to increase the time of action but also to increase the solubility of selected antibiotics for the treatment of ophthalmic infections. Two BSC II class substances, Azithromycin and Ofloxacin, with different mechanisms of action, have been incorporated into the in situ gel system after determining their solubility. The antibiotics-loaded in situ gel formulation was evaluated for its clarity, pH, rheological properties, and gel characteristics of gelling time, temperature, and capacity. The formulation demonstrated satisfactory clarity, appropriate pH, effective gelation properties in simulated tear fluid, and suitable rheological characteristics. In addition, APIs release insight has been studied through a dissolution test, and the effectivity against sensitive and resistant bacterial strains has been proved through the antimicrobial study. Therefore, our in situ gel system based on thermosensitive poloxamers, with two hydrophobic antibiotics, AZM and OFX, can be considered a valuable approach for ophthalmic drug delivery with an enhancement of the antibiotics bioavailability through increasing the contact time with the ocular surface and enhancing patient compliance.

Complex therapy of musculoskeletal pain: the role of centrally acting muscle relaxants

Chronic pain is the main manifestation of musculoskeletal diseases (MSDs), leading to deterioration of quality of life and loss of ability to work. The importance of this problem is determined by the widespread prevalence of MSDs, osteoarthritis (OA), acute and chronic non-specific back pain (NBP), periarticular soft tissues lesions. Introduction of effective methods of treatment of musculoskeletal pain (MSP) into medical practice is one of the fundamental tasks of modern medicine.The pathogenesis of MSP includes mechanisms such as injury, inflammation, peripheral sensitization, biomechanical disorders, dysfunction of the nociceptive system and psychoemotional disorders. Painful muscle tension plays an important role in the development of MSP, especially in NBP. Given the complex pathogenesis of MSP, its treatment is based on the combined use of drugs with different mechanisms of action and nonpharmacological methods. Non-steroidal anti-inflammatory drugs (NSAIDs) have a central place in this context. However, they can cause serious adverse reactions (ARs), so when choosing NSAIDs, it is necessary to consider comorbid pathology and risk factors. One of the most acceptable NSAIDs with a pronounced analgesic effect and low incidence of ARs is aceclofenac, which is available in various dosage forms (tablets, sachets, topical cream for external use). This medication is characterized by proven efficacy and good tolerability.Centrally acting muscle relaxants (CM) play an important role in the treatment of MSP. They eliminate muscle spasm, enhance the effect of analgesics and reduce the need for NSAIDs. The effect of CM has been demonstrated in spasticity and NBP. However, the use of many drugs of this group can be associated with serious ARs, which limits their use.Tolperisone has the best combination of efficacy and favorable safety profile among CM. Its positive effect in the complex treatment of NBP has been confirmed in several well-organized, placebo-controlled trials. There are also studies demonstrating the efficacy of tolperisone in OA. An important advantage of this drug is virtually no sedative effect, and no negative impact on hemodynamics and on the ability to perform concentration-intensive work. Emergence of a new form of tolperisone – extended-release tablets (Mydocalm® Long 450 mg) – increases patient compliance with CM therapy and facilitates the physician's work.

Impact of saflufenacil and glyphosate-based herbicides on the morphoanatomical and development of Enterolobium contortisiliquum (Vell.) Morong (Fabaceae): new insights into a non-target tropical tree species.

The unregulated use and improper management of herbicides can cause negative effects on non-target species and promote changes in biological communities. Therefore, the current study is aimed at understanding morphoanatomical responses and effects on seedling development induced by the herbicides glyphosate and saflufenacil in Enterolobium contortisiliquum, a non-target tropical species. The plants were cultivated in a greenhouse and subjected to herbicides at doses of 0, 160, 480, and 1440g a.e ha-1 for glyphosate, and 0, 25, 50, and 100g a.i ha-1 for saflufenacil. We conducted visual and morphological assessments over 90days post-application. Leaf samples were collected 12days after the application for anatomical analysis, and we also performed a micromorphometric analysis of the leaf tissues. Biomarkers of phytotoxicity were identified in plants exposed to both herbicides, even at the lowest doses, including in leaves without visual symptoms. The main morphological alterations were the decrease in growth, stem diameter, and dry mass. Furthermore, the leaves and stems visually exhibited chlorosis and necrosis. Both herbicides triggered anatomical modifications such as significant changes (p < 0.05) in the thickness of leaf tissues, hypertrophy, cell collapse, and changes in epicuticular waxes. However, the alterations induced by glyphosate were more widespread compared to saflufenacil, encompassing alterations in the root system. We confirmed that the different mechanisms of action of each herbicide and the existence of an underground reserve system in this species are intrinsically linked to the morphological and developmental responses described. Our findings suggest that E. contortisiliquum could be a potential bioindicator species for these herbicides in the environment, even at concentrations lower than those typically recommended for field application.

Co-delivery of Doxorubicin and VEGF siRNA using carcinoembryonic antigen-targeted chitosan nanoparticles for colorectal cancer

Developing a targeted nanocarrier-based therapeutic approach is highly effective in delivering therapeutics to specific cancer cells. Combining two or more therapeutic approaches with different mechanisms of action can effectively maintain their unique benefits while considerably improving cancer treatment. Doxorubicin (DOX) binds to DNA by intercalation and triggers a cascade of biochemical processes in tumor cells leading to death. Anti-VEGF medicines may sensitize cancer cells to chemotherapeutics by limiting blood supply and increasing penetration by disrupting tumor vasculature. In this study, DOX and vascular endothelial growth factor siRNA (VEGF siRNA) loaded chitosan nanoparticles (ChNPs) were prepared by using the ionic gelation method. The DOX-siRNA-ChNPs surface was then functionalized with carcinoembryonic antigen (CEA) targeted monoclonal antibody (DOX-siRNA-ChNPs-CMAb), thereby delivering therapeutic moieties into the cancer milieu. The cytotoxicity and cellular uptake of the developed nanocarrier were tested in-vitro on HT-29, which revealed that DOX-siRNA-ChNPs-CMAb possessed the highest cytotoxicity when compared with other prepared formulations and free DOX. The cellular uptake using fluorescence microscopy displayed a significantly higher uptake of DOX-siRNA-ChNPs-CMAb (targeted) than free DOX and DOX-siRNA-ChNPs (non-targeted). Apoptosis analysis in flow cytometry using annexin-V/PI staining demonstrated a substantially higher apoptosis rate of HT-29 cells using DOX-siRNA-ChNPs-CMAb than DOX-siRNA-ChNPs. Moreover, DOX-siRNA-ChNPs-CMAb were studied in CRC induced animal models, showing that DOX-siRNA-ChNPs-CMAb specifically targets CRC cells without showing organ toxicity. Thus, the novel approach of simultaneous delivery of DOX and siRNA using CMAb conjugated ChNPs demonstrated significant targeting in both in-vitro and in-vivo with minimal organ toxicity.

TREATMENT OF PULMONARY ARTERIAL HYPERTENSION ASSOCIATED WITH CONGENITAL HEART DEFECTS

Patients with pulmonary arterial hypertension, associated with congenital heart disease (PAH-CHD) are a heterogeneous population with a varied course of PH. Improvements in pediatric cardiac surgery have changed the epidemiology and survival rate of patients with CHD, of which 90% reach adulthood. Progress in terms of prognosis has also been observed among patients with PAH-CHD. Better survival was observed in ES compared with PAH after defect correction. Advances in surgical treatment of CHD and an increase in life expectancy have led to the study of PAH-CHD and the need to create recommendations for drug treatment of this category of patients. In most of studies, the evaluation of drug treatment of group 1 PAH was carried out without identifying its subgroups. And thus, according to existing recommendations, treatment algorhithms for patients with PAH-CHD are similar to approaches to other forms of PAH. However, various clinical, functional, physical and hemodynamic characteristics of patients with PAH-CHD call into question of correct risk stratification approaches development. Multicenter randomized clinical trials included predominantly a small number of patients with corrected defects, which does not allow the results to be interpreted for the entire population of patients with PAH-CHD. Data from single-center observational studies, expert opinion, and several randomized trials primarily involving patients with Eisenmenger syndrome (ES) indicate the effectiveness and safety of PAH-specific therapy in patients with PAH-CHD. In this literature review, we examined and showed the results of studies involving patients with PAH-CHD and their response to specific therapy. The results obtained significantly expanded the possibilities of using bosentan, sildenafil, epoprostenol, riociguat, ralinepag, sotatercept as they lead to improvement of functional capacity and hemodynamic parameters in patients with PAH-CHD, and only epoprostenol demonstrated an effect on prognosis. Combination PAH-specific therapy, initial or sequential administration of two or more drugs with different mechanisms of action, is an important treatment strategy for patients with PAH. The role of such therapy has increased in recent years. Based on the results of the AMBITION, SERAPHIN, GRIPHON, COMPASS-2 studies, initial or sequential oral combination PAH-specific therapy is recommended for patients with WHO FC II or III. At the same time, there is little evidence to support the effectiveness of this approach in ES patients. The use of anticoagulants in PAH-CHD remains controversial. Low-flow oxygen therapy should be considered individually and continued when there is a significant predominance of subjective or objective benefit. Iron deficiency is associated with poor survival in ES. It is important to note that microcytosis is rare in patients with iron deficiency cyanosis and a normal mean red cell volume does not indicate the absence of anemia. In cases of intolerance to oral iron, intravenous drugs should be used. Currently, based on existing guidelines, most centers follow a consistent symptom-based approach in the treatment of patients with PAH-CHD. Therapy begins with oral ERAs or PDE-5 inhibitors and is escalated if symptoms persist or clinical worsening occurs. If there is no effect of oral PAH-specific therapy, it is recommended to consider parenteral drugs.

Proteome Aggregation in Cells Derived from Amyotrophic Lateral Sclerosis Patients for Personalized Drug Evaluation.

Amyotrophic lateral sclerosis (ALS) is a progressive neurodegenerative disorder that currently lacks effective therapy. Given the heterogeneity of clinical and molecular profiles of ALS patients, personalized diagnostics and pathological characterization represent a powerful strategy to optimize patient stratification, thereby enabling personalized treatment. Immortalized lymphocytes from sporadic and genetic ALS patients recapitulate some pathological hallmarks of the disease, facilitating the fundamental task of drug screening. However, the molecular aggregation of ALS has not been characterized in this patient-derived cellular model. Indeed, protein aggregation is one of the most prominent features of neurodegenerative diseases, and therefore, models to test drugs against personalized pathological aggregation could help discover improved therapies. With this work, we aimed to characterize the aggregation profile of ALS immortalized lymphocytes and test several drug candidates with different mechanisms of action. In addition, we have evaluated the molecular aggregation in motor neurons derived from two hiPSC cell lines corresponding to ALS patients with different mutations in TARDBP. The results provide valuable insight into the different characterization of sporadic and genetic ALS patients' immortalized lymphocytes, their differential response to drug treatment, and the usefulness of proteome homeostasis characterization in patients' cells.

Second messenger c-di-AMP regulates multiple antibiotic sensitivity pathways in Mycobacterium smegmatis by discrete mechanisms.

One of the debilitating causes of high mortality in the case of tuberculosis and other bacterial infections is the resistance development against standard drugs. There are limited studies so far to describe how a bacterial second messenger molecule can directly participate in distinctive antibiotic tolerance characteristics of a cell in a mechanism-dependent manner. Here we show that intracellular cyclic di-AMP (c-di-AMP) concentration can modulate drug sensitivity of Mycobacterium smegmatis by interacting with an effector protein or interfering with the 5'-UTR regions in mRNA of the genes and thus causing transcriptional downregulation of important genes in the pathways. We studied four antibiotics with different mechanisms of action: rifampicin, ciprofloxacin, erythromycin, and tobramycin and subsequently found that the level of drug sensitivity of the bacteria is directly proportional to the c-di-AMP concentration inside the cell. Further, we unraveled the underlying molecular mechanisms to delineate the specific genes and pathways regulated by c-di-AMP and hence result in differential drug sensitivity in M. smegmatis.

Perception of the Capixaba population regarding the use and benefits of antidepressants and anxiolytics

Depression is a routine disorder characterized by at least two weeks of loss of pleasure, mood, and interest in basic daily activities. Treatment involves psychotherapy, lifestyle changes, and medication therapy with antidepressants. These medications increase the availability of neurotransmitters in the central nervous system through different mechanisms of action, such as Monoamine Oxidase Inhibitors, Tricyclic Antidepressants, Selective Serotonin Reuptake Inhibitors, and Atypicals. Studies indicate that, after the pandemic, mental health issues such as anxiety and depression became more frequent in society, leading to greater use of antidepressants, especially clonazepam, sertraline, and amitriptyline. This project aims to investigate this usage, focusing on the benefits and drawbacks from the user’s perspective. To this end, it was submitted to the Ethics and Human Research Council of UNESC, with a bibliographic review conducted in the PubMed, Lilacs, and Scielo databases during the approval period. After approval, the research was conducted through structured questionnaires, made available online to the Capixaba society. The study evaluated the rate of use of these psychotropic drugs in the region, the benefits, risks, and behaviors regarding the use of antidepressants and anxiolytics from the perspective of patients. The use of psychotropic drugs by the population can be satisfactory for treating mental disorders, but it is essential that these medications are used with caution and under the guidance of a healthcare professional. Regular monitoring helps to manage adverse effects, ensure the medication is working properly, and prevent long-term medication-related problems.

Improved survival among elderly patients with aggressive adult T-cell leukemia/lymphoma: Impact of mogamulizumab-containing chemotherapy.

Due to the poor prognosis of adult T-cell leukemia/lymphoma (ATL), new treatments are urgently needed, especially for elderly patients with aggressive ATL. The anti-CCR4 antibody drug mogamulizumab (MOG) has been approved for the treatment of untreated ATL. To analyze the impact of MOG on elderly patients, we conducted a retrospective analysis of patients aged 70years and older with aggressive ATL diagnosed at our institution between 2015 and 2021. Among 32 patients, including those who received best supportive care, the median survival time (MST) and 2-year overall survival (OS) rate were 14.6months (range, 0.0-83.7), and 34.7% [95% confidence interval (CI), 18.2-51.9], respectively, which were better than outcomes in our previous study. The MST and 2-year OS for patients treated with MOG-containing chemotherapy were 18.1months (range, 4.0-83.7) and 45.0% (95%CI, 23.1-64.7), respectively, demonstrating clear improvement. Adverse events observed with MOG-containing treatment, such as myelosuppression and skin rash, were similar to those reported previously. Univariate analysis identified comorbidity as a predictor of poor outcomes, but not intensity of MOG-containing treatment, suggesting a different mechanism of action than that of classical chemotherapy. Our study suggests that MOG-containing treatments are an option for elderly patients with ATL.

Single turnover transient state kinetics reveals processive protein unfolding catalyzed by Escherichia coli ClpB

Escherichia coli ClpB and Saccharomyces cerevisiae Hsp104 are AAA+ motor proteins essential for proteome maintenance and thermal tolerance. ClpB and Hsp104 have been proposed to extract a polypeptide from an aggregate and processively translocate the chain through the axial channel of its hexameric ring structure. However, the mechanism of translocation and if this reaction is processive remains disputed. We reported that Hsp104 and ClpB are non-processive on unfolded model substrates. Others have reported that ClpB is able to processively translocate a mechanically unfolded polypeptide chain at rates over 240 amino acids (aa) per second. Here, we report the development of a single turnover stopped-flow fluorescence strategy that reports on processive protein unfolding catalyzed by ClpB. We show that when translocation catalyzed by ClpB is challenged by stably folded protein structure, the motor enzymatically unfolds the substrate at a rate of ~0.9 aa s−1 with a kinetic step-size of ~60 amino acids at sub-saturating [ATP]. We reconcile the apparent controversy by defining enzyme catalyzed protein unfolding and translocation as two distinct reactions with different mechanisms of action. We propose a model where slow unfolding followed by fast translocation represents an important mechanistic feature that allows the motor to rapidly translocate up to the next folded region or rapidly dissociate if no additional fold is encountered.

Single turnover transient state kinetics reveals processive protein unfolding catalyzed by Escherichia coli ClpB.

Escherichia coli ClpB and Saccharomyces cerevisiae Hsp104 are AAA+ motor proteins essential for proteome maintenance and thermal tolerance. ClpB and Hsp104 have been proposed to extract a polypeptide from an aggregate and processively translocate the chain through the axial channel of its hexameric ring structure. However, the mechanism of translocation and if this reaction is processive remains disputed. We reported that Hsp104 and ClpB are non-processive on unfolded model substrates. Others have reported that ClpB is able to processively translocate a mechanically unfolded polypeptide chain at rates over 240 amino acids (aa) per second. Here, we report the development of a single turnover stopped-flow fluorescence strategy that reports on processive protein unfolding catalyzed by ClpB. We show that when translocation catalyzed by ClpB is challenged by stably folded protein structure, the motor enzymatically unfolds the substrate at a rate of ~0.9 aa s-1 with a kinetic step-size of ~60 amino acids at sub-saturating [ATP]. We reconcile the apparent controversy by defining enzyme catalyzed protein unfolding and translocation as two distinct reactions with different mechanisms of action. We propose a model where slow unfolding followed by fast translocation represents an important mechanistic feature that allows the motor to rapidly translocate up to the next folded region or rapidly dissociate if no additional fold is encountered.

Combination treatment with monoclonal antibodies for the management of severe asthma and immune-mediated inflammatory diseases: a comprehensive review.

Biological drugs have revolutionized the management of severe asthma, and a tailored treatment approach made it possible to consider remission as an achievable treatment target. The incidence of autoimmune diseases is increasing in many parts of the world. Patients suffering from severe asthma, eligible or already treated with an asthma-approved biologic agent, may suffer from another immune-mediated inflammatory disease (IMID) that could require the simultaneous use of a second monoclonal antibody. The real-life studies available in the literature describing the concurrent administration of an asthma-approved biologic agent with another biologic for a different immune disease, obtained through a systematic search on online databases based on monoclonal antibodies, were collected and analyzed. 26 articles were included in this review according to the prespecified inclusion and exclusion criteria. All included papers were retrospective in nature. Study designs were case reports (n=18), case series (n=3), retrospective chart reviews (n=3), retrospective observational studies (n=1), and cohort studies (n=1). The study is intended to present, within the current literature, all the administered combinations of severe asthma-approved biologics with monoclonal antibodies for a different indication. Those were grouped according to the IMID for whom the second biologic agent, with a different mechanism of action, was prescribed. The combinations prescribed to the cohort of patients specifically treating uncontrolled severe asthma were deeper evaluated in the discussion section, since an analysis of these therapeutic combinations deriving from real-life experiences may be useful to optimize the management of patients with severe asthma, ultimately leading to improved patient care and outcomes. Prospective registries and future studies are required to assess the safety and efficacy of combination therapies for severe asthmatic patients who suffer from an IMID.

7867 Treatment-Related Changes in Total Hip Bone Mineral Density and Fracture Risk Reduction for Drugs With Different Mechanisms of Action: The FNIH-ASBMR-SABRE Project

Abstract Disclosure: T. Vilaca: None. M.T. Schini: None. A.R. Thompson: None. E. Vittinghoff: None. L. Lui: None. S.K. Ewing: None. D.C. Bauer: None. D.M. Black: None. M. Bouxsein: None. R. Eastell: Consulting Fee; Self; Immunodiagnostic Systems, CL Bio, CureTeQ, Biocon, Takeda, UCB. Grant Recipient; Self; Alexion Pharmaceuticals, Inc., Osteolabs. Speaker; Self; Pharmacosmos, Alexion Pharmaceuticals, Inc., Amgen Inc, UCB. Introduction: To date, trials of new anti-osteoporosis therapies have used fractures as primary endpoints. In the FNIH-ASBMR-SABRE project, we posited that the treatment-related change in total hip BMD (THBMD) could be used as a surrogate endpoint for fractures in future clinical trials of new osteoporosis therapies. To demonstrate this, we compiled a large dataset of individual patient data (IPD) from randomized trials and showed a strong association between the change in THBMD at 24 months and reduction in fracture risk. To further explore the use of THBMD as a surrogate endpoint, here we examine whether the association is robust across drugs with different mechanisms of action. Methods: We used IDP (n&amp;gt;120,000 participants) from 22 randomized, placebo-controlled, double-blind trials of osteoporosis medications (17 anti-resorptive, 3 PTH analogs, 1 odanacatib, and 1 romosozumab). We calculated the treatment-related difference (active-placebo) in mean % change in THBMD at 12, 18, and 24 months for each trial. We determined the treatment-related fracture risk reductions for the entire follow-up period, using logistic regression for radiologic vertebral fractures and Cox regression for all clinical fractures (a combination of non-vertebral and clinical vertebral fractures). We used meta-regression to estimate the study-level association (r2) between treatment-related differences in THBMD changes and fracture risk reduction, including only the 17 trials of anti-resorptive drugs and then using the entire set of 22 trials. Since there were only 3 trials of anabolic drugs, we did not perform separate analyses for the anabolic trials. Results: The r2 values were similar between all trials and antiresorptive trials only for both fracture outcomes at all time points. Specifically, for vertebral fractures, the r2 was 0.59 vs 0.70 at 12 mo, 0.69 vs 0.74 at 18 mo, and 0.73 vs 0.78 at 24 mo for all trials vs anti-resorptive trials only. For all clinical fractures, the r2 was 0.46 vs 0.51 at 12 mo, 0.64 vs 0.60 at 18 mo, and 0.71 vs 0.65 at 24 mo for all trials vs anti-resorptive trials only. Conclusion: These results demonstrate that the associations between treatment-related changes in THBMD and fracture risk reductions are robust across anti-osteoporosis therapies with varying mechanisms of action. We conclude that the treatment-related difference in THBMD change would predict fracture reduction equally well for drugs with different mechanisms of action. Presentation: 6/2/2024

12227 The Battle Between Central And Nephrogenic Diabetes Insipidus

Abstract Disclosure: A.A. Luzuriaga Chavez: None. J.P. Hidalgo: None. A. Rao: None. N. Patel: None. Diabetes insipidus (DI) is a rare disorder characterized by excessive polyuria and polydipsia. The two main types include central diabetes insipidus (CDI), which results from antidiuretic hormone (ADH) deficiency and nephrogenic diabetes insipidus (NDI), defined by ADH resistance in the renal tubules. It can be challenging to distinguish between different types of DI in a critically ill patient. A 68-year-old female with a past medical history of hypertension, bipolar disorder came to the ER for complaints of chills and shortness of breath. She was transferred to the intensive care unit (ICU) for septic shock secondary to pneumonia and left pleural effusion. A chest tube was placed with improvement in her breathing and she was transferred out of the ICU. Four days later, the patient developed altered mental status, fevers and ICU was reconsulted due to concern for meningitis. A lumbar puncture was done with negative results but the brain MRI revealed ischemic sites involving both medial parietal cortices extending into both occipital poles, consistent with acute ischemia. Furthermore, the patient developed an increased urine output of 200ml per hour with a negative balance of 2.7L, increased sodium of 150, serum osmolality of 313 and urine osmolality of 196. The patient received desmopressin 1 mcg q 6 hrs with the persistence of hypernatremia. Upon further questioning, the patient had been on lithium therapy in the past for bipolar disorder. Amiloride 2.5mg BID was added to the treatment regimen. The patient’s hypernatremia and urine output improved and she was discharged on both amiloride and desmopressin to follow up for dose adjustments as needed. DI has a prevalence of 1 in 25000. Acquired CDI secondary to lesions in the hypophysis or hypothalamus highlights the major role of the central nervous system in regulating water homeostasis. This case report describes CDI developing after a stroke. Ischemia can cause hypoperfusion of osmoreceptors in the hypothalamus and posterior pituitary. Lithium can be frequently associated with NDI, usually seen in 20 to 40% of patients. Different mechanisms of action include lithium interference in renal collecting tubules by increasing cAMP in response to ADH and down-regulation of aquaporin-2 expression, which is accepted to be reversible with the cessation of the therapy. However, long-term treatment with lithium likely results in permanent NDI. Our patient had a history of lithium therapy which contributed to the development of symptoms of NDI and responded to a combination of desmopressin and amiloride. The successful therapy enforces the diagnosis of both a central and a peripheral pathology. Central and nephrogenic DI, despite stemming from distinct underlying causes, may concurrently manifest in critically ill patients. This case report emphasizes the need for physicians to evaluate for multiple causes of DI in a patient with water disturbances. Presentation: 6/1/2024

Effect of Caffeine and Nitrates Combination on Exercise Performance, Heart Rate and Oxygen Uptake: A Systematic Review and Meta-Analysis.

The evidence about the synergy of combining caffeine (CAF) and nitrates on exercise performance has not been summarized, although there is a possibility of additive/synergistic effects of the co-ingestion of these substances given their different mechanisms of action in central (CAF) and peripheral tissues (nitrates). The aim was to analyze the effects of co-supplementation of CAF and nitrates on sports performance in comparison to the isolated ingestion of these substances. The databases of PubMed, Web of Science, Medline, CiNAHL and SPORTDiscus were used until June 2024 following PRISMA guidelines. Randomized controlled trials, at least one single-blind trial, conducted in adults were considered. A meta-analysis was performed using the random effects model to calculate the standardized mean difference estimated by Hedges' g and 95% confidence intervals (CIs) for studies with four arms. Six studies were included (N = 95). The meta-analysis revealed that caffeine and nitrates supplementation (CAF+nitrates) did not enhance performance in time trials (TTs) over the CAF alone (g = -0.06; 95% CI = -0.46 to 0.35; p = 0.78) or nitrates alone (g = 0.29; 95% CI = -0.12 to 0.70; p = 0.17). CAF+nitrates did not affect heart rate during submaximal exercise trials over CAF alone (g = 0.04; 95% CI = -0.31 to 0.40; p = 0.80) or nitrates alone (g = -0.15; 95% CI = -0.50 to 0.20; p = 0.40). Likewise, CAF+nitrates did not affect oxygen uptake during submaximal exercise trials over CAF alone (g = -0.04; 95% CI = -0.45 to 0.37; p = 0.84) or nitrates alone (g = -0.29; 95% CI = -0.70 to 0.12; p = 0.16). CAF+nitrates did not offer further benefits on exercise performance or physiological variables from the isolated intake of CAF and nitrates.

Combined Oxygen-Enhanced MRI and Perfusion Imaging Detect Hypoxia Modification from Banoxantrone and Atovaquone and Track Their Differential Mechanisms of Action.

Oxygen-enhanced MRI (OE-MRI) has shown promise for quantifying and spatially mapping tumor hypoxia, either alone or in combination with perfusion imaging. Previous studies have validated the technique in mouse models and in patients with cancer. Here, we report the first evidence that OE-MRI can track change in tumor oxygenation induced by two drugs designed to modify hypoxia. Mechanism of action of banoxantrone and atovaquone were confirmed using in vitro experiments. Next, in vivo OE-MRI studies were performed in Calu6 and U87 xenograft tumor models, alongside fluorine-18-fluoroazomycin arabinoside PET and immunohistochemistry assays of hypoxia. Neither drug altered tumor size. Banoxantrone reduced OE-MRI hypoxic fraction in Calu6 tumors by 52.5% ± 12.0% (P = 0.008) and in U87 tumors by 29.0% ± 15.8% (P = 0.004) after 3 days treatment. Atovaquone reduced OE-MRI hypoxic fraction in Calu6 tumors by 53.4% ± 15.3% (P = 0.002) after 7 days therapy. PET and immunohistochemistry provided independent validation of the MRI findings. Finally, combined OE-MRI and perfusion imaging showed that hypoxic tissue was converted into necrotic tissue when treated by the hypoxia-activated cytotoxic prodrug banoxantrone, whereas hypoxic tissue became normoxic when treated by atovaquone, an inhibitor of mitochondrial complex III of the electron transport chain. OE-MRI detected and quantified hypoxia reduction induced by two hypoxia-modifying therapies and could distinguish between their differential mechanisms of action. These data support clinical translation of OE-MRI biomarkers in clinical trials of hypoxia-modifying agents to identify patients demonstrating biological response and to optimize treatment timing and scheduling. Significance: For the first time, we show that hypoxic fraction measured by oxygen-enhanced MRI (OE-MRI) detected changes in tumor oxygenation induced by two drugs designed specifically to modify hypoxia. Furthermore, when combined with perfusion imaging, OE-MRI hypoxic volume distinguished the two drug mechanisms of action. This imaging technology has potential to facilitate drug development, enrich clinical trial design, and accelerate clinical translation of novel therapeutics into clinical use.

Bleeding Complications of Anticoagulation Therapy in Clinical Practice-Epidemiology and Management: Review of the Literature.

Due to their very wide range of indications, anticoagulants are one of the most commonly used drug groups. Although these drugs are characterized by different mechanisms of action, the most common complication of their use is still bleeding episodes, the frequency of which depends largely on the clinical condition of the patient using such therapy. For this reason, to this day, the best method of preventing bleeding complications remains the assessment of bleeding risk using scales such as HAS-BLED. There are many reports in the literature assessing the occurrence of this type of complication after the use of drugs affecting the coagulation process, as well as many reports comparing individual groups of drugs with different mechanisms of action. However, there are still no clear guidelines that would indicate which group of anticoagulants should be preferred in particular groups of patients. The aim of our article is to summarize the data collected so far regarding the safety of using specific groups of anticoagulants and the frequency of bleeding complications after their use.