Potential roles for eNOS and NrF2 /HO-1 signaling in the ameliorative effect of lixisenatide on diabetes-induced kidney injury in rats and its amplification by ticagrelor co-administration.

Antioxidant and anti-inflammatory effects of lixisenatide (LX) and ticagrelor (TC) have been previously identified in type 2 diabetes mellitus (T2DM). Diabetic nephropathy is one of the major complications of T2DM. In the current study, we examined the potential protective effects of LX and TC on experimentally induced diabetic nephropathy in T2DM rats and their possible molecular mechanisms. To examine this possibility, rats were fed a high-fat diet (HFD) for 12 weeks, followed by a single injection of 35 mg/kg streptozotocin (STZ) to induce T2DM. 10 µg/kg LX and 25 mg/kg TC were given alone or in combination to T2DM rats for 4 weeks. The kidney examination of T2DM rats showed clear deterioration. T2DM rats exhibited significantly higher body weight, blood glucose, hemostatic model assessment for insulin resistance (HOMA-IR), blood urea nitrogen (BUN), serum creatinine, kidney reactive oxygen species (ROS), nuclear factor-κ B (NF-κ B), and transforming growth factor-ß (TGF-ß ), and significantly lower serum insulin, urine creatinine, creatinine clearance (CRCL), kidney superoxide dismutase (SOD), glutathione reduced (GSH), nuclear factor erythroid 2 (NrF2 ), heme oxygenase-1 (HO-1), and endothelial nitric oxide synthase (eNOS) when compared to control rats. Single treatment with LX or TC showed obvious ameliorative effects on kidney complications in T2DM rats, with more ameliorative effects with the combined administration of both drugs. Conclusion: Our investigation found that both LX and TC could significantly ameliorate the development of diabetic nephropathy via stimulating NrF2 /HO-1 antioxidant pathway in addition to increasing eNOS and decreasing NF-κ B renal tissue concentrations, and these effects were markedly augmented by their combined administration.

ALM Resuscitation With Brain and Multiorgan Protection for Far-Forward Operations: Survival at Hypotensive Pressures.

INTRODUCTION: Non-compressible torso hemorrhagic (NCTH) shock is the leading cause of potentially survivable trauma on the battlefield. New hypotensive drug therapies are urgently required to resuscitate and protect the heart and brain following NCTH. Our aim was to examine the strengths and limitations of permissive hypotension and discuss the development of small-volume adenosine, lidocaine, and Mg2+ (ALM) fluid resuscitation in rats and pigs. MATERIALS AND METHODS: For review of permissive hypotension, a literature search was performed from inception up to November 2023 using PubMed, Cochrane, and Embase databases, with inclusion of animal studies, clinical trials and reviews with military and clinical relevance. For the preclinical study, adult female pigs underwent laparoscopic liver resection. After 30 minutes of bleeding, animals were resuscitated with 4 mL/kg 3% NaCl ± ALM bolus followed 60 minutes later with 4 h 3 mL/kg/h 0.9% NaCl ± ALM drip (n = 10 per group), then blood transfusion. Mean arterial pressure (MAP) and cardiac output (CO) were continuously measured via a left ventricular pressure catheter and pulmonary artery catheter, respectively. Systemic vascular resistance (SVR) was calculated using the formula: 80 × (MAP - CVP)/CI. Oxygen delivery was calculated as the product of CO and arterial oxygen content. RESULTS: Targeting a MAP of ∼50 mmHg can be harmful or beneficial, depending on how CO and SVR are regulated. A theoretical example shows that for the same MAP of 50 mmHg, a higher CO and lower SVR can lead to a nearly 2-fold increase in O2 supply. We further show that in animal models of NCTH, 3% NaCl ALM bolus and 0.9% NaCl ALM drip induce a hypotensive, high flow, vasodilatory state with maintained tissue O2 supply and neuroprotection. ALM therapy increases survival by resuscitating the heart, reducing internal bleeding by correcting coagulopathy, and decreasing secondary injury. CONCLUSIONS: In rat and pig models of NCTH, small-volume ALM therapy resuscitates at hypotensive pressures by increasing CO and reducing SVR. This strategy is associated with heart and brain protection and maintained tissue O2 delivery. Translational studies are required to determine reproducibility and optimal component dosing. ALM therapy may find wide utility in prehospital and far-forward military environments.

[Calcium Dibutyryl Adenosine Cyclophosphate Enhances the Effect of Metoprolol in Treating Older Adults With Heart Failure Combined With Arrhythmia]. / äºŒä¸é °çŽ¯ç£·è ºè‹·é’™å¯å¢žå¼ºç¾Žæ‰˜æ´›å°”å¯¹è€å¹´å¿ƒåŠ›è¡°ç«­åˆå¹¶å¿ƒå¾‹å¤±å¸¸æ‚£è€ çš„æ²»ç–—æ•ˆæžœ.

Objective: To explore the effect and safety of calcium dibutyryl adenosine cyclophosphate (dbcAMP-Ca) combined with metoprolol in the treatment of older adults with heart failure combined with arrhythmia. Methods: A total of 102 elderly patients with heart failure combined with arrhythmia were enrolled in our hospital between February 2021 and April 2023. The list of patients enrolled was entered into a random database by independent staffs not involved in the study and random assignment sequences were generated by the SAS9.4 software. Then, the 102 elderly patients were divided into a control group ( n=51) and an experimental group ( n=51). Patients in the control group were given metoprolol at an initial dose of 6.25 mg/d, which was gradually increased to the target dose of 25 mg/d. Patients in the experimental group were given 40 mg of dbcAMP-Ca once a day via intravenous drip in addition to the treatment given to the control group. Both groups were treated for 4 weeks. The rate of effective response to clinical treatment (the number of cases achieving significant effects and those achieving some effects divided by the total number of cases in the group) was defined as the main outcome index. Secondary indexes included cardiac function, heart rate variability, exercise ability, hemorheology, myocardial injury indexes, inflammatory indexes, and the occurrence of adverse reactions. Results: The rate of effective response to clinical treatment was higher in the experimental group than that in the control group (94.12% [48/51] vs. 78.43% [40/51], P<0.05). After treatment, the left ventricular end-diastolic and end-systolic dimensions (LVEDD and LVESD) and the interventricular septal thickness (IVS) were lower in the experimental group than those in the control group, while the left ventricular ejection fraction (LVEF) and the stroke volume (SV) were higher in the experimental group than those in the control group ( P<0.05). In terms of heart rate variability after treatment, the standard deviation of all the normal-to-normal intervals/the average of all the normal-to-normal intervals (SDNN/SDANN), the percentage of NN50 in the total number of normal-to-normal intervals (PNN50%), and the root mean square of the differences between adjacent normal-to-normal intervals/root mean square differences of successive R-R intervals (RMSSD) were higher in the experimental group than those in the control group ( P<0.05). In terms of exercise capacity after treatment, the subjects in the experimental group covered more distance in the 6-min walk test than those in the control group did ( P<0.05). In terms of the hemorheology indexes after treatment, the levels of platelet aggregation rate (PAgT), fibrinogen (FIB), erythrocyte sedimentation rate (ESR), and whole blood viscosity (ηb) were lower in the experimental group than those in the control group ( P<0.05). In terms of the myocardial injury indexes after treatment, the levels of serum N-terminal pro-brain natriuretic peptide (NT-pro BNP) and cardiac troponin I (cTnI) were lower in the experimental group than those in the control group, while the levels of insulin-like growth factor 1 (IGF-1) and cardiotrophin 1 (CT-1) were higher in the experimental group than those in the control group ( P<0.05). In terms of the inflammatory indexes after treatment, the levels of interleukin-6 (IL-6), high-sensitive C-reactive protein (hs-CRP), and tumor necrosis factor-α (TNF-α) were lower in the experimental group than those in the control group ( P<0.05). The incidence of adverse reactions in the experimental group (9.80%) and that in the control group (7.84%) were comparable ( P>0.05). Conclusion: The use of dbcAMP-Ca in addition to metoprolol can effectively improve cardiac function, heart rate variability, and exercise tolerance, while inhibiting inflammatory response in elderly patients with heart failure combined with arrhythmia, with high medication safety. The combination medication shows better safety and therapeutic effects than those of metoprolol used alone.

Coronary and Systemic Vasodilator Responsiveness of Patients Receiving Conventional Intermittent or Nocturnal Hemodialysis.

BACKGROUND: Nocturnal hemodialysis (nHD) restores the attenuated brachial artery vasodilator responsiveness of patients receiving conventional intermittent hemodialysis (iHD). Its impact on coronary vasodilatation is unknown. METHODS: We evaluated 25 patients on hemodialysis who fulfilled transplant criteria: 15 on iHD (4-hour sessions, 3 d/wk) and 10 on nHD (≈40 h/wk over 8-10-hour sessions) plus 6 control participants. Following diagnostic angiography, left anterior descending (LAD) coronary flow reserve and mean luminal diameter were quantified at baseline and during sequential intracoronary administration of adenosine (infusion and bolus), nitroglycerin (bolus), acetylcholine (infusion), acetylcholine coinfused with vitamin C, and, finally, sublingual nitroglycerin. RESULTS: Coronary flow reserve in those receiving nHD was augmented relative to iHD (3.28±0.26 versus 2.17±0.12 [mean±SEM]; P<0.03) but attenuated, relative to controls (4.80±0.63; P=0.011). Luminal dilatations induced by intracoronary adenosine and nitroglycerin were similar in nHD and controls but blunted in the iHD cohort (P<0.05 versus both). ACh elicited vasodilatation in controls but constriction in both dialysis groups (both P<0.05, versus control); vitamin C coinfusion had no effect. Sublingual nitroglycerin increased mid-left anterior descending diameter and reduced mean arterial pressure in controls (+15.2±2.68%; -16.00±1.60%) and in nHD recipients (+14.78±5.46%; -15.82±1.32%); iHD responses were markedly attenuated (+1.9±0.86%; -5.89±1.41%; P<0.05, all comparisons). CONCLUSIONS: Coronary and systemic vasodilator responsiveness to both adenosine and nitroglycerin is augmented in patients receiving nHD relative to those receiving iHD, whereas vasoconstrictor responsiveness to acetylcholine does not differ. By improving coronary conduit and microvascular function, nHD may reduce the cardiovascular risk of patients on dialysis.

Use of coronary physiology to guide revascularization in clinical practice: results of the F(FR)2 registry.

BACKGROUND: Despite the recommendation of coronary physiology to guide revascularization in angiographically intermediate stenoses without established correlation to ischemia, its uptake in clinical practice is slow. AIMS: This study aimed to analyze the use of coronary physiology in clinical practice. METHODS: Based on a multicenter registry (Fractional Flow Reserve Fax Registry, F(FR)2, ClinicalTrials.gov identifier NCT03055910), clinical use, consequences, and complications of coronary physiology were systematically analyzed. RESULTS: F(FR)2 enrolled 2,000 patients with 3,378 intracoronary pressure measurements. Most measurements (96.8%) were performed in angiographically intermediate stenoses. Out of 3,238 lesions in which coronary physiology was used to guide revascularization, revascularization was deferred in 2,643 (78.2%) cases. Fractional flow reserve (FFR) was the most common pressure index used (87.6%), with hyperemia induced by an intracoronary bolus of adenosine in 2,556 lesions (86.4%) and intravenous adenosine used for 384 measurements (13.0%). The route of adenosine administration did not influence FFR results (change-in-estimate -3.1% for regression model predicting FFR from diameter stenosis). Agreement with the subsequent revascularization decision was 93.4% for intravenous and 95.0% for intracoronary adenosine (p = 0.261). Coronary artery occlusion caused by the pressure wire was reported in two cases (0.1%) and dissection in three cases (0.2%), which was fatal once (0.1%). CONCLUSIONS: In clinical practice, intracoronary pressure measurements are mostly used to guide revascularization decisions in angiographically intermediate stenoses. Intracoronary and intravenous administration of adenosine seem equally suited. While the rate of serious complications of wire-based intracoronary pressure measurements in clinical practice seems to be low, it is not negligible.

Intracoronary adenosine compared with adrenaline and verapamil in the treatment of no-reflow phenomenon following primary PCI in STEMI patients.

BACKGROUND: no-reflow can complicate up to 25% of pPCI and is associated with significant morbidity and mortality. We aimed to compare the outcomes of intracoronary epinephrine and verapamil with intracoronary adenosine in the treatment of no-reflow after primary percutaneous coronary intervention (pPCI). METHODS: 108 STEMI patients had no-reflow during pPCI were assigned into four groups. Group 1, in which epinephrine and verapamil were injected through a well-cannulated guiding catheter. Group 2, in which same drugs were injected in the distal coronary bed through a microcatheter or perfusion catheter. Group 3, in which adenosine was injected through a guiding catheter. Group 4, in which adenosine was injected in distal coronary bed. Primary end point was the achievement of TIMI III flow and MBG II or III. Secondary end point was major adverse cardiovascular and cerebrovascular events (MACCEs) during hospital stay. RESULTS: The study groups did not differ in their baseline characteristics. Primary end point was achieved in 15 (27.8%) patients in the guide-delivery arm compared with 34 (63%) patients in the local-delivery arm, p < 0.01. However, the primary end point did not differ between the epinephrine/verapamil group and the adenosine group (27 (50%) vs 22 (40.7%), p = 0.334). The secondary end points were similar between the study groups. CONCLUSION: Local delivery of epinephrine, verapamil and adenosine in the distal coronary bed is more effective in achieving TIMI III flow with MBG II or III compared with their guide-delivery in patients who suffered no-reflow during pPCI. There was no difference between epinephrine/verapamil Vs. adenosine.

Identification of hypothermia-inducing neurons in the preoptic area and activation of them by isoflurane anesthesia and central injection of adenosine.

Hibernation and torpor are not passive responses caused by external temperature drops and fasting but are active brain functions that lower body temperature. A population of neurons in the preoptic area was recently identified as such active torpor-regulating neurons. We hypothesized that the other hypothermia-inducing maneuvers would also activate these neurons. To test our hypothesis, we first refined the previous observations, examined the brain regions explicitly activated during the falling phase of body temperature using c-Fos expression, and confirmed the preoptic area. Next, we observed long-lasting hypothermia by reactivating torpor-tagged Gq-expressing neurons using the activity tagging and DREADD systems. Finally, we found that about 40-60% of torpor-tagged neurons were activated by succeeding isoflurane anesthesia and by icv administration of an adenosine A1 agonist. Isoflurane-induced and central adenosine-induced hypothermia is, at least in part, an active process mediated by the torpor-regulating neurons in the preoptic area.

Anti-hair loss effect of a shampoo containing caffeine and adenosine.

BACKGROUND: Hair loss is a widespread health problem that affects numerous individuals and is associated with age, lack of sleep, stress, endocrine problems, and other problems. Caffeine exerts various pharmacological effects, particularly after ingestion. The caffeine-induced inhibition of phosphodiesterases can increase intracellular cAMP concentrations, ultimately resulting in stimulatory effects on cell metabolism and proliferation. Hence, caffeine has been confirmed to inhibit hair loss caused by premature termination of the hair growth phase. Adenosine also improves hair loss by stimulating hair growth and thickening hair shafts. However, further empirical evidence is required to comprehensively assess the efficacy of hair loss treatment and prevention using a formulation of caffeine and adenosine in specific proportions in shampoos. OBJECTIVES: This study aimed to evaluate a shampoo with caffeine and adenosine as a daily scalp care product for hair loss in 77 subjects aged 18-60 years. METHODS: The overall and local hair densities were assessed using professional cameras and dermoscopes at different magnifications and distances. Five hairs that came off the participant's head were randomly selected to measure hair diameter. The self-assessment questionnaires were filled on third month of product use. RESULTS: The combination of caffeine and adenosine in the shampoo significantly enhanced hair density compared to that of the baseline. The results revealed a significant reduction in hair loss. The hair diameters of the subjects did not change significantly. Most of the participants (71.05%) were satisfied with their hair after using the product. CONCLUSIONS: Shampoos containing caffeine and adenosine have been demonstrated to exert therapeutic benefits for reducing hair loss.

Seizure suppression and neuroprotection in soman-exposed rats following delayed intramuscular treatment of adenosine A1 receptor agonist as an adjunct to standard medical treatment.

Soman produces excitotoxic effects by inhibiting acetylcholinesterase in the cholinergic synapses and neuromuscular junctions, resulting in soman-induced sustained status epilepticus (SSE). Our previous work showed delayed intramuscular (i.m.) treatment with A1 adenosine receptor agonist N-bicyclo-[2.2.1]-hept-2-yl-5'-chloro-5'-deoxyadenosine (ENBA) alone suppressed soman-induced SSE and prevented neuropathology. Using this same rat soman seizure model, we tested if delayed therapy with ENBA (60 mg/kg, i.m.) would terminate seizure, protect neuropathology, and aid in survival when given in conjunction with current standard medical countermeasures (MCMs): atropine sulfate, 2-PAM, and midazolam (MDZ). Either 15- or 30-min following soman-induced SSE onset, male rats received atropine and 2-PAM plus either MDZ or MDZ + ENBA. Electroencephalographic (EEG) activity, physiologic parameters, and motor function were recorded. Either 2- or 14-days following exposure surviving rats were euthanized and perfused for histology. All animals treated with MDZ + ENBA at both time points had 100% EEG seizure termination and reduced total neuropathology compared to animals treated with MDZ (2-day, p = 0.015 for 15-min, p = 0.002 for 30-min; 14-day, p < 0.001 for 15-min, p = 0.006 for 30-min), showing ENBA enhanced MDZ's anticonvulsant and neuroprotectant efficacy. However, combined MDZ + ENBA treatment, when compared to MDZ treatment groups, had a reduction in the 14-day survival rate regardless of treatment time, indicating possible enhancement of MDZ's neuronal inhibitory effects by ENBA. Based on our findings, ENBA shows promise as an anticonvulsant and neuroprotectant in a combined treatment regimen following soman exposure; when given as an adjunct to standard MCMs, the dose of ENBA needs to be adjusted.

Effects of intrarenal pelvic infusion of tumour necrosis factor-α and interleukin 1-ß on reno-renal reflexes in anaesthetised rats.

OBJECTIVE: Reno-renal reflexes are disturbed in cardiovascular and hypertensive conditions when elevated levels of pro-inflammatory mediators/cytokines are present within the kidney. We hypothesised that exogenously administered inflammatory cytokines tumour necrosis factor alpha (TNF-α) and interleukin (IL)-1ß modulate the renal sympatho-excitatory response to chemical stimulation of renal pelvic sensory nerves. METHODS: In anaesthetised rats, intrarenal pelvic infusions of vehicle [0.9% sodium chloride (NaCl)], TNF-α (500 and 1000 ng/kg) and IL-1ß (1000 ng/kg) were maintained for 30 min before chemical activation of renal pelvic sensory receptors was performed using randomized intrarenal pelvic infusions of hypertonic NaCl, potassium chloride (KCl), bradykinin, adenosine and capsaicin. RESULTS: The increase in renal sympathetic nerve activity (RSNA) in response to intrarenal pelvic hypertonic NaCl was enhanced during intrapelvic TNF-α (1000 ng/kg) and IL-1ß infusions by almost 800% above vehicle with minimal changes in mean arterial pressure (MAP) and heart rate (HR). Similarly, the RSNA response to intrarenal pelvic adenosine in the presence of TNF-α (500 ng/kg), but not IL-1ß, was almost 200% above vehicle but neither MAP nor HR were changed. There was a blunted sympatho-excitatory response to intrapelvic bradykinin in the presence of TNF-α (1000 ng/kg), but not IL-1ß, by almost 80% below vehicle, again without effect on either MAP or HR. CONCLUSION: The renal sympatho-excitatory response to renal pelvic chemoreceptor stimulation is modulated by exogenous TNF-α and IL-1ß. This suggests that inflammatory mediators within the kidney can play a significant role in modulating the renal afferent nerve-mediated sympatho-excitatory response.

Exogenous Ketone Supplement Administration Abrogated Isoflurane-Anesthesia-Induced Increase in Blood Glucose Level in Female WAG/Rij Rats.

It has been demonstrated that isoflurane-induced anesthesia can increase the blood glucose level, leading to hyperglycemia and several adverse effects. The administration of a mix of ketone diester (KE) and medium-chain triglyceride (MCT) oil, named KEMCT, abolished the isoflurane-anesthesia-induced increase in blood glucose level and prolonged the recovery time from isoflurane anesthesia in a male preclinical rodent model, Wistar Albino Glaxo/Rijswijk (WAG/Rij) rats. While most preclinical studies use exclusively male animals, our previous study on blood glucose changes in response to KEMCT administration showed that the results can be sex-dependent. Thus, in this study, we investigated female WAG/Rij rats, whether KEMCT gavage (3 g/kg/day for 7 days) can change the isoflurane (3%)-anesthesia-induced increase in blood glucose level and the recovery time from isoflurane-evoked anesthesia using the righting reflex. Moreover, KEMCT-induced ketosis may enhance both the extracellular level of adenosine and the activity of adenosine A1 receptors (A1Rs). To obtain information on the putative A1R mechanism of action, the effects of an A1R antagonist, DPCPX (1,3-dipropyl-8-cyclopentylxanthine; intraperitoneal/i.p. 0.2 mg/kg), on KEMCT-generated influences were also investigated. Our results show that KEMCT supplementation abolished the isoflurane-anesthesia-induced increase in blood glucose level, and this was abrogated by the co-administration of DPCPX. Nevertheless, KEMCT gavage did not change the recovery time from isoflurane-induced anesthesia. We can conclude that intragastric gavage of exogenous ketone supplements (EKSs), such as KEMCT, can abolish the isoflurane-anesthesia-induced increase in blood glucose level in both sexes likely through A1Rs in WAG/Rij rats, while recovery time was not affected in females, unlike in males. These results suggest that the administration of EKSs as an adjuvant therapy may be effective in mitigating metabolic side effects of isoflurane, such as hyperglycemia, in both sexes.

Safety evaluation of adenosine, lidocaine and magnesium (ALM) intranasal therapy toward human nasal epithelial cells in vitro.

Adenosine, lidocaine and Mg2+ (ALM) solution is an emerging therapy that reduces secondary injury after intravenous administration in experimental models of traumatic brain injury (TBI). Intranasal delivery of ALM may offer an alternative route for rapid, point-of-care management of TBI. As a preliminary safety screen, we evaluated whether ALM exerts cytotoxic or inflammatory effects on primary human nasal epithelial cells (pHNEC) in vitro. Submerged monolayers and air-liquid interface cultures of pHNEC were exposed to media only, normal saline only, therapeutic ALM or supratherapeutic ALM for 15 or 60 min. Safety was measured through viability, cytotoxicity, apoptosis, cellular and mitochondrial stress, and inflammatory mediator secretion assays. No differences were found in viability or cytotoxicity in cultures exposed to saline or ALM for up to 60 min, with no evidence of apoptosis after exposure to supratherapeutic ALM concentrations. Despite comparable inflammatory cytokine secretion profiles and mitochondrial activity, cellular stress responses were significantly lower in cultures exposed to ALM than saline. In summary, data show ALM therapy has neither adverse toxic nor inflammatory effects on human nasal epithelial cells, setting the stage for in vivo toxicity studies and possible clinical translation of intranasal ALM therapy for TBI treatment.

Duration of adenosine-induced myocardial hyperaemia: insights from quantitative 13N-ammonia positron emission tomography myocardial perfusion imaging.

AIMS: This study aimed to assess the impact of adenosine on quantitative myocardial blood flow (MBF) in a rapid stress-rest protocol compared with a rest-stress protocol using 13N-ammonia positron emission tomography (PET) myocardial perfusion imaging (MPI) and to gain insights into the time dependency of such effects. METHODS AND RESULTS: Quantitative MBF at rest (rMBF) and during adenosine-induced stress (sMBF) and myocardial flow reserve (MFR) were obtained from 331 retrospectively identified patients who underwent 13N-ammonia PET MPI for suspected chronic coronary syndrome and who all exhibited no perfusion defects. Of these, 146 (44.1%) underwent a rapid stress-rest protocol with a time interval (Δtstress-rest) of 20 ± 4 min between adenosine infusion offset and rest imaging, as per clinical routine. The remaining 185 (55.9%) patients underwent a rest-stress protocol and served as the reference. Groups did not differ regarding demographics, risk factors, medication, left ventricular function, and calcium scores. rMBF was significantly higher in the stress-rest vs. the rest-stress group [0.80 (interquartile range 0.66-1.00) vs. 0.70 (0.58-0.83) mL·min-1·g-1, P < 0.001], and, as sMBF was identical between groups [2.52 (2.20-2.96) vs. 2.50 (1.96-3.11), P = 0.347], MFR was significantly lower in the stress-rest group [3.07 (2.43-3.88) vs. 3.50 (2.63-4.10), P = 0.007]. There was a weak correlation between Δtstress-rest and rMBF (r = -0.259, P = 0.002) and between Δtstress-rest and MFR (r = 0.163, P = 0.049), and the proportion of patients with abnormally high rMBF was significantly decreasing with increasing Δtstress-rest. CONCLUSION: Intravenously applied adenosine induces a long-lasting hyperaemic effect on the myocardium. Consequently, rapid stress-rest protocols could lead to an overestimation of rMBF and an underestimation of MFR.

Prognostic value of a novel artificial intelligence-based coronary CTA-derived ischemia algorithm among patients with normal or abnormal myocardial perfusion.

BACKGROUND: Among patients with obstructive coronary artery disease (CAD) on coronary computed tomography angiography (CTA), downstream positron emission tomography (PET) perfusion imaging can be performed to assess the presence of myocardial ischemia. A novel artificial-intelligence-guided quantitative computed tomography ischemia algorithm (AI-QCTischemia) aims to predict ischemia directly from coronary CTA images. We aimed to study the prognostic value of AI-QCTischemia among patients with obstructive CAD on coronary CTA and normal or abnormal downstream PET perfusion. METHODS: AI-QCTischemia was calculated by blinded analysts among patients from the retrospective coronary CTA cohort at Turku University Hospital, Finland, with obstructive CAD on initial visual reading (diameter stenosis ≥50%) being referred for downstream 15O-H2O-PET adenosine stress perfusion imaging. All coronary arteries with their side branches were assessed by AI-QCTischemia. Absolute stress myocardial blood flow ≤2.3 â€‹ml/g/min in ≥2 adjacent segments was considered abnormal. The primary endpoint was death, myocardial infarction, or unstable angina pectoris. The median follow-up was 6.2 [IQR 4.4-8.3] years. RESULTS: 662 of 768 (86%) patients had conclusive AI-QCTischemia result. In patients with normal 15O-H2O-PET perfusion, an abnormal AI-QCTischemia result (n â€‹= â€‹147/331) vs. normal AI-QCTischemia result (n â€‹= â€‹184/331) was associated with a significantly higher crude and adjusted rates of the primary endpoint (adjusted HR 2.47, 95% CI 1.17-5.21, p â€‹= â€‹0.018). This did not pertain to patients with abnormal 15O-H2O-PET perfusion (abnormal AI-QCTischemia result (n â€‹= â€‹269/331) vs. normal AI-QCTischemia result (n â€‹= â€‹62/331); adjusted HR 1.09, 95% CI 0.58-2.02, p â€‹= â€‹0.794) (p-interaction â€‹= â€‹0.039). CONCLUSION: Among patients with obstructive CAD on coronary CTA referred for downstream 15O-H2O-PET perfusion imaging, AI-QCTischemia showed incremental prognostic value among patients with preserved perfusion by 15O-H2O-PET imaging, but not among those with reduced perfusion.

Pulmonary blood volume measured by 82Rb-PET in patients with chronic obstructive pulmonary disease: a retrospective cohort study.

In patients with chronic obstructive pulmonary disease (COPD), pulmonary vascular dysfunction and destruction are observable before the onset of detectable emphysema, but it is unknown whether this is associated with central hypovolemia. We investigated if patients with COPD have reduced pulmonary blood volume (PBV) evaluated by 82Rb-positron emission tomography (PET) at rest and during adenosine-induced hyperemia. This single-center retrospective cohort study assessed 6,301 82Rb-PET myocardial perfusion imaging (MPI) examinations performed over a 6-yr period. We compared 77 patients with COPD with 44 healthy kidney donors (controls). Cardiac output ([Formula: see text]) and mean 82Rb bolus transit time (MBTT) were used to calculate PBV. [Formula: see text] was similar at rest (COPD: 3,649 ± 120 mL vs. control: 3,891 ± 160 mL, P = 0.368) but lower in patients with COPD compared with controls during adenosine infusion (COPD: 5,432 ± 124 mL vs. control: 6,185 ± 161 mL, P < 0.050). MBTT was shorter in patients with COPD compared with controls at rest (COPD: 8.7 ± 0.28 s vs. control: 11.4 ± 0.37 s, P < 0.001) and during adenosine infusion (COPD: 9.2 ± 0.28 s vs. control: 10.2 ± 0.37 s, P < 0.014). PBV was lower in patients with COPD, even after adjustment for body surface area, sex, and age at rest [COPD: 530 (29) mL vs. 708 (38) mL, P < 0.001] and during adenosine infusion [COPD: 826 (29) mL vs. 1,044 (38) mL, P < 0.001]. In conclusion, patients with COPD show evidence of central hypovolemia, but it remains to be determined whether this has any diagnostic or prognostic impact.NEW & NOTEWORTHY The present study demonstrated that patients with chronic obstructive pulmonary disease (COPD) exhibit central hypovolemia compared with healthy controls. Pulmonary blood volume may thus be a relevant physiological and/or clinical outcome measure in future COPD studies.

Diagnosis and Management of Paroxysmal Supraventricular Tachycardia.

Importance: Paroxysmal supraventricular tachycardia (PSVT), defined as tachyarrhythmias that originate from or conduct through the atria or atrioventricular node with abrupt onset, affects 168 to 332 per 100 000 individuals. Untreated PSVT is associated with adverse outcomes including high symptom burden and tachycardia-mediated cardiomyopathy. Observations: Approximately 50% of patients with PSVT are aged 45 to 64 years and 67.5% are female. Most common symptoms include palpitations (86%), chest discomfort (47%), and dyspnea (38%). Patients may rarely develop tachycardia-mediated cardiomyopathy (1%) due to PSVT. Diagnosis is made on electrocardiogram during an arrhythmic event or using ambulatory monitoring. First-line acute therapy for hemodynamically stable patients includes vagal maneuvers such as the modified Valsalva maneuver (43% effective) and intravenous adenosine (91% effective). Emergent cardioversion is recommended for patients who are hemodynamically unstable. Catheter ablation is safe, highly effective, and recommended as first-line therapy to prevent recurrence of PSVT. Meta-analysis of observational studies shows single catheter ablation procedure success rates of 94.3% to 98.5%. Evidence is limited for the effectiveness of long-term pharmacotherapy to prevent PSVT. Nonetheless, guidelines recommend therapies including calcium channel blockers, ß-blockers, and antiarrhythmic agents as management options. Conclusion and Relevance: Paroxysmal SVT affects both adult and pediatric populations and is generally a benign condition. Catheter ablation is the most effective therapy to prevent recurrent PSVT. Pharmacotherapy is an important component of acute and long-term management of PSVT.

[Angina and no obstruction on coronary angiography : New approaches to the diagnosis and treatment of vasomotor disorders]. / Angina pectoris ohne Stenosen in der Koronarangiographie : Neue Wege zur Diagnose und Therapie von Vasomotionsstörungen.

BACKGROUND: Clinical management of patients with angina and no obstructive coronary artery disease (ANOCA) is still challenging. This scenario affects up to 50% of patients undergoing diagnostic coronary angiography due to suspected coronary artery disease. Many patients report a long and debilitating history before adequate diagnostics and management are initiated. OBJECTIVES: This article describes the current recommendations for diagnostic assessments and treatment in patients with ANOCA. Focus is placed on invasive diagnostics in the catheter laboratory, pharmacological/interventional treatment as well as the patient journey. RESULTS: In patients with ANOCA, the current European Society of Cardiology (ESC) guidelines suggest that invasive assessments using acetylcholine and adenosine for the diagnosis of an underlying coronary vasomotor disorder should be considered. Acetylcholine is used to diagnose coronary spasm, whereas adenosine is used in conjunction with a wire-based assessment for the measurement of coronary flow reserve and microvascular resistance. The invasive assessments allow the determination of what are referred to as endotypes (coronary spasm, impaired coronary flow reserve, enhanced microvascular resistance or a combination thereof). Establishing a diagnosis is helpful to: (a) initiate targeted treatment to improve quality of life, (b) reassure the patient that a cardiac cause is found and (c) to assess individual prognosis. CONCLUSIONS: Currently, patients with ANOCA are often not adequately managed. Referral to specialised centres is recommended to prevent long and debilitating patient histories until expertise in diagnosis and treatment becomes more widespread.

Regulatory T cell-derived exosome mediated macrophages polarization for osteogenic differentiation in fracture repair.

Refractory fracture presents an intractable challenge in trauma treatment. Selective polarization of macrophages as well as the recruitment of osteogenic precursor cells play key roles in osteogenic differentiation during fracture healing. Here we constructed regulatory T cell (Treg)-derived exosomes (Treg-Exo) for the treatment of fracture. The obtained exosomes displayed a spheroid shape with a hydrated particle size of approximately 130 nm. With further purification using CD39 and CD73 antibody-modified microfluidic chips, CD39 and CD73 specifically expressing exosomes were obtained. This kind of Treg-Exo utilized the ectonucleotidases of CD39 and CD73 to catalyze the high level of ATP in the fracture area into adenosine. The generated adenosine further promoted the selective polarization of macrophages. When interacting with mesenchymal stem cells (MSCs, osteogenic precursor cells), both Treg-Exo and Treg-Exo primed macrophages facilitated the proliferation and differentiation of MSCs. After administration in vivo, Treg-Exo effectively promoted fracture healing compared with conventional T cell-derived exosome. To further improve the delivery efficacy of exosomes and integrate multiple biological processes of fracture healing, an injectable hydrogel was fabricated to co-deliver Treg-Exo and stromal cell-derived factor 1 alpha (SDF-1α). With the dual effect of Treg-Exo for macrophage polarization and SDF-1α for MSC recruitment, the multifunctional hydrogel exerted a synergistic effect on fracture repair acceleration. This study provided a promising therapeutic candidate and synergistic strategy for the clinical treatment of fracture.

Key considerations in navigating ticagrelor's reported effect on heparin-induced thrombocytopenia functional assays in a landscape of limited data.

PURPOSE: This article discusses key considerations regarding ticagrelor's reported effect on heparin-induced thrombocytopenia functional assays, such as literature gaps and possible management strategies. SUMMARY: Limited data indicate that ticagrelor may induce false-negative results in functional assays used in the diagnosis of heparin-induced thrombocytopenia. False-negative functional assays for heparin-induced thrombocytopenia could have catastrophic consequences. The manufacturer labeling of ticagrelor now includes a warning for this potential drug-laboratory interaction. This article suggests areas that would benefit from further research and strategies in navigating this possible interaction. CONCLUSION: Clinicians should exercise caution when evaluating functional assays for heparin-induced thrombocytopenia in patients receiving ticagrelor. This article offers suggestions for future areas of research and potential management strategies.