Altered Serotonin 1B Receptor Binding After Escitalopram for Depression Is Correlated With Treatment Effect.

BACKGROUND: Major depressive disorder (MDD) is commonly treated with selective serotonin reuptake inhibitors (SSRIs). SSRIs inhibit the serotonin transporter (5-HTT), but the downstream antidepressant mechanism of action of these drugs is poorly understood. The serotonin 1B (5-HT1B) receptor is functionally linked to 5-HTT and 5-HT1B receptor binding and 5-HT1B receptor mRNA is reduced in the raphe nuclei after SSRI administration in primates and rodents, respectively. The effect of SSRI treatment on 5-HT1B receptor binding in patients with MDD has not been examined previously. This positron emission tomography (PET) study aimed to quantify brain 5-HT1B receptor binding changes in vivo after SSRI treatment for MDD in relation to treatment effect. METHODS: Eight unmedicated patients with moderate to severe MDD underwent PET with the 5-HT1B receptor radioligand [11C]AZ10419369 before and after 3 to 4 weeks of treatment with the SSRI escitalopram 10 mg daily. Depression severity was assessed at time of PET and after 6 to 7 weeks of treatment with the Montgomery-Åsberg Depression Rating Scale. RESULTS: We observed a significant reduction in [11C]AZ10419369 binding in a dorsal brainstem (DBS) region containing the median and dorsal raphe nuclei after escitalopram treatment (P = .036). Change in DBS [11C]AZ10419369 binding correlated with Montgomery-Åsberg Depression Rating Scale reduction after 3-4 (r = 0.78, P = .021) and 6-7 (r = 0.94, P < .001) weeks' treatment. CONCLUSIONS: Our findings align with the previously reported reduction of 5-HT1B receptor binding in the raphe nuclei after SSRI administration and support future studies testing change in DBS 5-HT1B receptor binding as an SSRI treatment response marker.

Patterns of activity correlate with symptom severity in major depressive disorder patients.

Objective measures, such as activity monitoring, can potentially complement clinical assessment for psychiatric patients. Alterations in rest-activity patterns are commonly encountered in patients with major depressive disorder. The aim of this study was to investigate whether features of activity patterns correlate with severity of depression symptoms (evaluated by Montgomery-Åsberg Rating Scale (MADRS) for depression). We used actigraphy recordings collected during ongoing major depressive episodes from patients not undergoing any antidepressant treatment. The recordings were acquired from two independent studies using different actigraphy systems. Data was quality-controlled and pre-processed for feature extraction following uniform procedures. We trained multiple regression models to predict MADRS score from features of activity patterns using brute-force and semi-supervised machine learning algorithms. The models were filtered based on the precision and the accuracy of fitting on training dataset before undergoing external validation on an independent dataset. The features enriched in the models surviving external validation point to high depressive symptom severity being associated with less complex activity patterns and stronger coupling to external circadian entrainers. Our results bring proof-of-concept evidence that activity patterns correlate with severity of depressive symptoms and suggest that actigraphy recordings may be a useful tool for individual evaluation of patients with major depressive disorder.

Dietary nitrate attenuates high-fat diet-induced obesity via mechanisms involving higher adipocyte respiration and alterations in inflammatory status.

Emerging evidence indicates that dietary nitrate can reverse several features of the metabolic syndrome, but the underlying molecular mechanisms still remain elusive. The aim of the present study was to explore mechanisms involved in the effects of dietary nitrate on the metabolic dysfunctions induced by high-fat diet (HFD) in mice. Four weeks old C57BL/6 male mice, exposed to HFD for ten weeks, were characterised by increased body weight, fat content, increased fasting glucose and impaired glucose clearance. All these metabolic abnormalities were significantly attenuated by dietary nitrate. Mechanistically, subcutaneous primary mouse adipocytes exposed to palmitate (PA) and treated with nitrite exhibited higher mitochondrial respiration, increased protein expression of total mitochondrial complexes and elevated gene expression of the thermogenesis gene UCP-1, as well as of the creatine transporter SLC6A8. Finally, dietary nitrate increased the expression of anti-inflammatory markers in visceral fat, plasma and bone marrow-derived macrophages (Arginase-1, Egr-2, IL-10), which was associated with reduction of NADPH oxidase-derived superoxide production in macrophages. In conclusion, dietary nitrate may have therapeutic utility against obesity and associated metabolic complications possibly by increasing adipocyte mitochondrial respiration and by dampening inflammation and oxidative stress.

Electroconvulsive therapy in bipolar depression - effectiveness and prognostic factors.

OBJECTIVE: Electroconvulsive therapy (ECT) is used in patients with severe forms of bipolar depression. ECT is effective but not all patients respond. The aim of this study was to determine prognostic factors for response to ECT in patients hospitalized for bipolar depression. METHODS: Data were obtained from several national Swedish registers. All patients with bipolar depression treated with ECT in any hospital in Sweden between 2011 and 2016 for whom information about ECT response was available were included (n = 1251). Response was defined as a score on the Clinical Global Impression - Improvement scale of one or two. Univariate and multivariate logistic regression were conducted to investigate associations between socio-demographic and clinical factors and response. RESULTS: Response was achieved in 80.2% patients. Older age was associated with higher response rate to ECT. Patients with comorbid obsessive-compulsive disorder or personality disorder, and patients previously treated with lamotrigine had lower response rate. CONCLUSION: Electroconvulsive therapy for bipolar depression was associated with very high response rates. The strongest prognostic factors were higher age, absence of comorbid obsessive-compulsive disorder or personality disorder, and less prior pharmacologic treatment.

The creation of an endovascular exit through the vessel wall using a minimally invasive working channel in order to reach all human organs.

Since the establishment of the Seldinger technique for secure entry to the vascular system, there has been a rapid evolution in imaging and catheters that has made the arteries and veins internal routes to any place in the body for interventions. It is curious that a general exit from the vasculature in a similar manner has not been proposed earlier. Possibly, the simplest reason is that accidental perforation of the vasculature by guide wire or catheter is a feared adverse event in endovascular intervention. Most places in the body can be reached by ultrasonography or computed tomography-guided intervention. Some organs such as the central nervous system, the heart and pancreas are harder to access and, in some organs, like the kidney, repeated percutaneous punctions to cover large areas is not suitable. We present a new general purpose micro-endovascular device creating a working channel to these 'hard to reach' organs by an inverted Seldinger technique. This review details this trans-vessel wall technique, which has been studied in pancreas for transplantation of insulin-producing cells, for injection of contrast agent to the heart and to the brain, bowels and kidney in rat, rabbit, swine and macaque monkeys with up to one year of follow-up without adverse events. Furthermore, the payloads that can be given through such a system are briefly discussed. Drugs, cells, gene vectors and other therapeutic substances may be injected directly to the tissue to increase efficacy and decrease risk of off-site adverse effects.

Explosion characteristics for Li-ion battery electrolytes at elevated temperatures.

Li-ion batteries are used in electronic devices and electric cars, yet they create safety concerns due to the possibility of the release of combustible materials. The electrolyte, one of the main components in a Li-ion cell, consists of organic carbonates. Venting and thermal runaway release organic carbonates and when mixed with air, it can result in fires and explosions. A 20-liter explosion sphere was used to determine the explosion characteristics for three typical carbonates used in electrolytes, at 373 K, and 100 kPa absolute pressure. The explosion pressure and the maximum rate of explosion pressure rise are presented for the carbonates and for hydrogen, methane, and propane, and the explosive limits for the carbonates are also identified at the same conditions. This allowed a comparison of the explosion characteristics for the carbonates with those for hydrogen, methane, and propane. Theoretical calculations gave a higher explosion pressure than that from the experimental results most likely due to losses in the hydrocarbon experiments. The carbonates analyzed have very similar explosion pressures and rate of explosion pressure rise as propane. The explosion characteristics found for the three carbonates can be used in future consequence and risk assessments for Li-ion battery installations.

Superselective endovascular tissue access using trans-vessel wall technique: feasibility study for treatment applications in heart, pancreas and kidney in swine.

OBJECTIVES: With the emergence of targeted cell transplantation and gene therapy, there is a need for minimally invasive tissue access to facilitate delivery of therapeutic substrate. The objective of this study was to demonstrate the suitability of an endovascular device which is able to directly access tissue and deliver therapeutic agent to the heart, kidney and pancreas without need to seal the penetration site. METHODS: In vivo experiments were performed in 30 swine, including subgroups with follow-up to evaluate complications. The previously described trans-vessel wall (VW) device was modified to be sharper and not require tip detachment to seal the VW. Injections into targets in the heart (n = 13, 24-h follow-up n = 5, 72-h follow-up n = 3), kidney (n = 8, 14-day follow-up n = 3) and pancreas (n = 5) were performed. Some animals were used for multiple organ injections. Follow-up consisted of clinical monitoring, angiography and necropsy. Transvenous (in heart) and transarterial approaches (in heart, kidney and pancreas) were used. Injections were targeted towards the subepicardium, endomyocardium, pancreas head and tail, and kidney subcapsular space and cortex. RESULTS: Injections were successful in target organs, visualized by intraparenchymal contrast on fluoroscopy and by necropsy. No serious complications (defined as heart failure or persistent arrhythmia, haemorrhage requiring treatment or acute kidney injury) were encountered over a total of 157 injections. CONCLUSIONS: The trans-VW device can achieve superselective injections to the heart, pancreas and kidney for delivery of therapeutic substances without tip detachment. All parts of these organs including the subepicardium, pancreas tail and renal subcapsular space can be efficiently reached.

Mechanisms underlying blood pressure reduction by dietary inorganic nitrate.

Nitric oxide (NO) importantly contributes to cardiovascular homeostasis by regulating blood flow and maintaining endothelial integrity. Conversely, reduced NO bioavailability is a central feature during natural ageing and in many cardiovascular disorders, including hypertension. The inorganic anions nitrate and nitrite are endogenously formed after oxidation of NO synthase (NOS)-derived NO and are also present in our daily diet. Knowledge accumulated over the past two decades has demonstrated that these anions can be recycled back to NO and other bioactive nitrogen oxides via serial reductions that involve oral commensal bacteria and various enzymatic systems. Intake of inorganic nitrate, which is predominantly found in green leafy vegetables and beets, has a variety of favourable cardiovascular effects. As hypertension is a major risk factor of morbidity and mortality worldwide, much attention has been paid to the blood pressure reducing effect of inorganic nitrate. Here, we describe how dietary nitrate, via stimulation of the nitrate-nitrite-NO pathway, affects various organ systems and discuss underlying mechanisms that may contribute to the observed blood pressure-lowering effect.

Self-assessed remission rates after electroconvulsive therapy of depressive disorders.

BACKGROUND: Electroconvulsive therapy (ECT) effectively treats severe depression, but not all patients remit. The aim of the study was to identify clinical factors that associate with ECT-induced remission in a community setting. METHODS: Depressed patients who underwent ECT in 2011-2014 were identified from the Swedish National Quality Register for ECT. Remission was defined as self-rated Montgomery-Åsberg Depression Rating Scale scores of 0-10 after ECT. Other registers provided data on previous antidepressant use, comorbidities, and demographics. RESULTS: Of 1671 patients fulfilling the inclusion criteria, 42.8% achieved remission. Older age, education length over 9 years, psychotic symptoms, shorter duration of preceding antidepressant use, pulse width stimulus≥0.50ms, absence of substance use disorders, anxiety diagnosis, lamotrigine, and benzodiazepines, were associated with remission. CONCLUSIONS: This study shows that psychotic subtype of depression and older age are clinically relevant predictors of a beneficial ECT effect. Additionally, ECT outcomes can be further improved by optimizing the treatment technique and concomitant medication.

The burden of illness in patients with hyponatraemia in Sweden: a population-based registry study.

BACKGROUND: Hyponatraemia (HN; serum sodium level < 135 mmol/l) is the most common electrolyte disturbance seen in clinical practice, and is associated with varying spectrum of symptoms. Syndrome of inappropriate antidiuretic hormone secretion (SIADH) is the most common aetiology in hospitalised patients, and can be caused by several different underlying conditions. AIMS: The objectives of this study were to retrospectively examine the baseline characteristics, clinical outcomes and hospital resource utilisation of patients with HN and/or SIADH in Sweden over a 10-year period from 2001 to 2011. Additional analysis was performed on subpopulations of patients with hip fracture, pneumonia and small cell lung cancer (SCLC) to see if trends in outcomes were consistent across a broad range of aetiologies commonly associated with the condition. METHODS: Patient information was taken from the Swedish National Patient Registry, the Swedish Cancer Registry, the Swedish Cause of Death Register and the Swedish Prescribed Drug Register. A total of 34,537 patients (4.38%) were identified with HN and/or SIADH, with the incidence and prevalence rising over the 10-year study period. RESULTS: Of the 34,537 patients identified, 841 had hip fracture, 2635 had pneumonia and 106 had SCLC. Compared with matched control patients, those with HN and/or SIADH had a longer length of hospital stay, a higher re-admission rate and a shorter time to re-admission. CONCLUSIONS: This study showed that HN and/or SIADH negatively impact patient outcomes and healthcare resources related to hospital stay irrespective of the underlying cause. The impact of HN is not confined to the initial hospitalisation, as re-admission rates are also affected.

Therapeutic effects of inorganic nitrate and nitrite in cardiovascular and metabolic diseases.

Nitric oxide (NO) is generated endogenously by NO synthases to regulate a number of physiological processes including cardiovascular and metabolic functions. A decrease in the production and bioavailability of NO is a hallmark of many major chronic diseases including hypertension, ischaemia-reperfusion injury, atherosclerosis and diabetes. This NO deficiency is mainly caused by dysfunctional NO synthases and increased scavenging of NO by the formation of reactive oxygen species. Inorganic nitrate and nitrite are emerging as substrates for in vivo NO synthase-independent formation of NO bioactivity. These anions are oxidation products of endogenous NO generation and are also present in the diet, with green leafy vegetables having a high nitrate content. The effects of nitrate and nitrite are diverse and include vasodilatation, improved endothelial function, enhanced mitochondrial efficiency and reduced generation of reactive oxygen species. Administration of nitrate or nitrite in animal models of cardiovascular disease shows promising results, and clinical trials are currently ongoing to investigate the therapeutic potential of nitrate and nitrite in hypertension, pulmonary hypertension, peripheral artery disease and myocardial infarction. In addition, the nutritional aspects of the nitrate-nitrite-NO pathway are interesting as diets suggested to protect against cardiovascular disease, such as the Mediterranean diet, are especially high in nitrate. Here, we discuss the potential therapeutic opportunities for nitrate and nitrite in prevention and treatment of cardiovascular and metabolic diseases.

Superselective intra-arterial umbilical cord blood administration to BM in experimental animals.

Umbilical cord blood (UCB) as a source of hematopoietic stem cells for transplantation is limited by the low number of cells and delayed engraftment. UCB cells are infused i.v. for transplantation, although only a proportion of the cells reach the BM. We investigated whether UCB could be administered safely using superselective intra-arterial (i.a.) injection. We injected human UCB (5 × 10(6)) into the aorta in rats, into the iliac artery in mice and into the femoral nutrient artery (FNA) in rabbits. We used angiography, immunohistochemistry, intravital microscopy and qPCR to assess safety end points and the distribution of injected cells. All animals showed normal behavior. No evidence of organ infarction was noted. UCB injected into the FNA of rabbits did not change the flow rates, measured by angiography. By qPCR, we found significantly higher fold-change values in the injected BM compared with i.v. injection (P=0.0087). Using intravital microscopy we visualized the mouse capillary bed during i.a. injection without cellular congestion. In summary, we show that i.a. infusion of UCB is safe and reaches an eightfold increase in engraftment in the BM compared with i.v. infusion. These studies lay the foundation for clinical trials.

Clinical evidence demonstrating the utility of inorganic nitrate in cardiovascular health.

The discovery of nitric oxide and its role in almost every facet of human biology opened a new avenue for treatment through manipulation of its canonical signaling and by attempts to augment endogenous nitric oxide generation through provision of substrate and co-factors to the endothelial nitric oxide synthase complex. This has been particularly so in the cardiovascular system and it is well recognized that there is reduced bioavailable nitric oxide in patients with both cardiovascular risk factors and manifest vascular disease. However, these attempts have failed to deliver the expected benefits of such an approach. Recently, an alternative pathway for nitric oxide synthesis has been elucidated that can produce authentic nitric oxide from the 1 electron reduction of inorganic nitrite. Furthermore, it has long been known that symbiotic, facultative, oral microflora can facilitate the reduction of inorganic nitrate, that is ingested in the average diet in millimolar amounts, to inorganic nitrite itself. Thus, there exists an alternative reductive pathway from nitrate, via nitrite as an intermediate, to nitric oxide that provides a novel pathway that may be amenable to therapeutic manipulation. As such, various research groups have explored the utility of manipulation of this nitrate-nitrite-nitric oxide pathway in situations in which nitric oxide is known to have a prominent role. Animal and early-phase human studies of both inorganic nitrite and nitrate supplementation have shown beneficial effects in blood pressure control, platelet function, vascular health and exercise capacity. This review considers in detail the pathways of inorganic nitrate bioactivation and the evidence of clinical utility to date on the cardiovascular system.

Endovascular method for transplantation of insulin-producing cells to the pancreas parenchyma in swine.

Insulin-producing cells are transplanted by portal vein injection as an alternative to pancreas transplantation in both clinical and preclinical trials. Two of the main limitations of portal vein transplantation are the prompt activation of the innate immunity and concomitant loss of islets and a small but significant risk of portal vein thrombosis. Furthermore, to mimic physiological release, the insulin-producing cells should instead be located in the pancreas. The trans-vessel wall approach is an endovascular method for penetrating the vessel wall from the inside. In essence, a working channel is established to the parenchyma of organs that are difficult to access by percutaneous technique. In this experiment, we accessed the extra-vascular pancreatic parenchyma in swine by microendovascular technique and injected methylene blue, contrast fluids and insulin-producing cells without acute adverse events. Further, we evaluated the procedure itself by a 1-year angiographical follow-up, without adverse events. This study shows that the novel approach utilizing endovascular minimal invasiveness coupled to accurate trans-vessel wall placement of an injection in the pancreatic parenchyma with insulin-producing cells is possible. In clinical practice, the potential benefits compared to portal vein cell transplantation should significantly improve endocrine function of the graft and potentially reduce adverse events.

Influence of growth hormone on circulating fibroblast growth factor 21 levels in humans.

OBJECTIVE: Findings from animal studies indicate that growth hormone (GH) may stimulate the production of the putative metabolic regulator fibroblast growth factor 21 (FGF21). We investigated whether circulating FGF21 levels are altered in patients with GH deficiency and characterized how levels of this growth factor are influenced by acute and long-term administration of GH, and the potential relationship between FGF21 and nonesterified fatty acids (NEFAs). DESIGN AND SETTING: GH-deficient patients (n = 9) were studied prior to and during 1 year of replacement with GH. Healthy subjects (n = 8) received an intravenous bolus of GH with or without concomitant oral glucose. Healthy subjects and patients with heterozygous familial hypercholesterolaemia (n = 23) were monitored following increasing doses of GH for 3 weeks. The main outcome measures were serum FGF21 and NEFA levels. Studies were performed at two academic centres. RESULTS: GH-deficient patients had FGF21 levels within the normal range, and GH replacement did not influence circulating FGF21 or NEFA concentrations. Acute GH administration to healthy control subjects did not change FGF21 levels, whereas an oral glucose load increased serum FGF21 by 25% and reduced NEFA levels by 48%. Similar effects were seen on administration of glucose together with GH. However, FGF21 levels increased dose dependently up to 3.7-fold in control subjects treated with GH for 3 weeks; simultaneously NEFA levels were increased by 47%. CONCLUSIONS: GH is not critical for the maintenance of basal serum FGF21 levels in humans, but circulating FGF21 levels increase following administration of GH to healthy individuals. There is no correlation between plasma NEFA and circulating FGF21 levels.

L-arginine or tempol supplementation improves renal and cardiovascular function in rats with reduced renal mass and chronic high salt intake.

AIM: Early life reduction in nephron number and chronic high salt intake cause development of renal and cardiovascular disease, which has been associated with oxidative stress and nitric oxide (NO) deficiency. We investigated the hypothesis that interventions stimulating NO signalling or reducing oxidative stress may restore renal autoregulation, attenuate hypertension and reduce renal and cardiovascular injuries following reduction in renal mass and chronic high salt intake. METHODS: Male Sprague-Dawley rats were uninephrectomized (UNX) or sham-operated at 3 weeks of age and given either a normal-salt (NS) or high-salt (HS) diet. Effects on renal and cardiovascular functions were assessed in rats supplemented with substrate for NO synthase (L-Arg) or a superoxide dismutase mimetic (Tempol). RESULTS: Rats with UNX + HS developed hypertension and displayed increased renal NADPH oxidase activity, elevated levels of oxidative stress markers in plasma and urine, and reduced cGMP in plasma. Histological analysis showed signs of cardiac and renal inflammation and fibrosis. These changes were linked with abnormal renal autoregulation, measured as a stronger tubuloglomerular feedback (TGF) response. Simultaneous treatment with L-Arg or Tempol restored cGMP levels in plasma and increased markers of NO signalling in the kidney. This was associated with normalized TGF responses, attenuated hypertension and reduced signs of histopathological changes in the kidney and in the heart. CONCLUSION: Reduction in nephron number during early life followed by chronic HS intake is associated with oxidative stress, impaired renal autoregulation and development of hypertension. Treatment strategies that increase NO bioavailability, or reduce levels of reactive oxygen species, were proven beneficial in this model of renal and cardiovascular disease.

Nitric oxide and endothelin-1 release after one-lung ventilation during thoracoabdominal esophagectomy.

One-lung ventilation (OLV) is applied during esophagectomy to improve exposure during the thoracic part of the operation. Collapse of lung tissue, shunting of pulmonary blood flow, and changes in alveolar oxygenation during and after OLV may possibly induce an ischemia-reperfusion response in the lung, which may affect the pulmonary endothelium. Such a reaction might thereby contribute to the frequently occurring respiratory complications among these patients. In this small trial, 30 patients were randomized to either OLV (n= 16) or two-lung ventilation (TLV, n= 14) during esophagectomy. Central venous and arterial plasma samples were taken before and after OLV/TLV for analysis of nitrite and a metabolite of nitric oxide (NO), and also during the 1st, 2nd, 3rd, and 10th postoperative day for analysis of endothelin, another endothelium-derived vasoactive mediator. Lung biopsies were taken before and after OLV or TLV, and analyzed regarding immunofluorescence for isoform of NO synthase, a protein upregulated during inflammatory response and also vascular congestion. No changes in lung isoform of NO synthase immunofluorescence or vascular congestion were registered after neither OLV nor TLV. Plasma nitrite and endothelin levels were similar in the two study groups. We conclude that OLV does not seem to have any influence on key regulators of pulmonary vascular tone and inflammation, i.e. NO and endothelin. From this perspective, OLV seems to be a safe method, which defends its clinical position to facilitate surgical exposure during thoracoabdominal esophagectomy.