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Introduction and objectives Coronary artery calcium (CAC) score improves the accuracy of risk stratification for atherosclerotic cardiovascular disease (ASCVD) events compared with traditional cardiovascular risk factors. We evaluated the interaction of coronary atherosclerotic burden as determined by the CAC score with the prognostic benefit of lipid-lowering therapies in the primary prevention setting. Methods We reviewed the MEDLINE, EMBASE, and Cochrane databases for studies including individuals without a previous ASCVD event who underwent CAC score assessment and for whom lipid-lowering therapy status stratified by CAC values was available. The primary outcome was ASCVD. The pooled effect of lipid-lowering therapy on outcomes stratified by CAC groups (0, 1-100, > 100) was evaluated using a random effects model. Results Five studies (1 randomized, 2 prospective cohort, 2 retrospective) were included encompassing 35 640 individuals (female 38.1%) with a median age of 62.2 [range, 49.6-68.9] years, low-density lipoprotein cholesterol level of 128 (114-146) mg/dL, and follow-up of 4.3 (2.3-11.1) years. ASCVD occurrence increased steadily across growing CAC strata, both in patients with and without lipid-lowering therapy. Comparing patients with (34.9%) and without (65.1%) treatment exposure, lipid-lowering therapy was associated with reduced occurrence of ASCVD in patients with CAC > 100 (OR, 0.70; 95%CI, 0.53-0.92), but not in patients with CAC 1-100 or CAC 0. Results were consistent when only adjusted data were pooled. Conclusions Among individuals without a previous ASCVD, a CAC score > 100 identifies individuals most likely to benefit from lipid-lowering therapy, while undetectable CAC suggests no treatment benefit.

Percutaneous coronary interventions performed at coronary bifurcations yield high rates of stent thrombosis (ST). The aim of the present study was to investigate the predictors of ST in contemporary coronary bifurcation percutaneous coronary interventions. We retrospectively investigated the BIFURCAT (comBined Insights From the Unified RAIN and COBIS bifurcAtion regisTries) registry on coronary bifurcations to assess the incidence and predictors of definite ST, which were the study primary endpoints. Predictors of ST among patients on dual antiplatelet therapy (DAPT) were also examined. A total of 5330 patients were included. After a mean 2-years follow-up, 64 (1.2%) patients experienced ST. 42 (65.6%) ST patients were on DAPT. At multivariable analysis, age (HR 1.02, CI 1.01 to 1.05, p = 0,027), smoking status (HR 2.57, CI 1.49 to 4.44, p = 0.001), chronic kidney disease (HR 2.26, CI 1.24 to 4.12, p = 0.007) and a 2-stent strategy (HR 2.38, CI 1.37 to 4.14, p = 0.002) were independent predictors of ST, whereas intracoronary imaging (HR 0.42, CI 0.23 to 0.78, p = 0.006) and final kissing balloon (FKB) (HR 0.48, CI 0.29 to 0.82, p = 0.007) were protective against ST. Among patients on DAPT, smoking status and a 2-stent strategy significantly increased the risk of ST, while intracoronary imaging and FKB reduced the risk. In conclusion, age, smoking status, chronic kidney disease and a 2-stent strategy were significant predictors of ST, whereas intracoronary imaging use and FKB had a protective effect. Only smoking status and a 2-stent strategy significantly predicted ST in DAPT subgroup, while intracoronary imaging and FKB had a protective role.

C/EBP homologous protein (CHOP) is a transcription factor that is elevated in adipose tissue across many models of diabetes and metabolic stress. Although increased CHOP levels are associated with the terminal response to endoplasmic reticulum stress and apoptosis, there is no evidence for CHOP mediated apoptosis in the adipose tissue during diabetes. CHOP protein levels increase in parallel with protein succination, a fumarate derived cysteine modification, in the adipocyte during metabolic stress. We investigated the factors contributing to sustained CHOP proteins levels in the adipocyte, with an emphasis on the regulation of CHOP protein turnover by metabolite-driven modification of Keap1 cysteines. CHOP protein stability was investigated in conditions of nutrient stress due to high glucose or elevated fumarate (fumarase knockdown model); where cysteine succination is specifically elevated. CHOP protein turnover is significantly reduced in models of elevated glucose and fumarate with a ~30% increase in CHOP stability (p > 0.01), in part due to decreased CHOP phosphorylation. Sustained CHOP levels occur in parallel with elevated heme-oxygenase-1, a production of increased Nrf2 transcriptional activity and Keap1 modification. While Keap1 is directly succinated in the presence of excess fumarate derived from genetic knockdown of fumarase (fumarate levels are elevated >20-fold), it is the oxidative modification of Keap1 that predominates in adipocytes matured in high glucose (fumarate increases 4–5 fold). Elevated fumarate indirectly regulates CHOP stability through the induction of oxidative stress. The antioxidant N-acetylcysteine (NAC) reduces fumarate levels, protein succination and CHOP levels in adipocytes matured in high glucose. Elevated CHOP does not contribute elevated apoptosis in adipocytes, but plays a redox-dependent role in decreasing the adipocyte secretion of interleukin-13, an anti-inflammatory chemokine. NAC treatment restores adipocyte IL-13 secretion, confirming the redox-dependent regulation of a potent anti-inflammatory eotaxin. This study demonstrates that physiological increases in the metabolite fumarate during high glucose exposure contributes to the presence of oxidative stress and sustained CHOP levels in the adipocyte during diabetes. The results reveal a novel metabolic link between mitochondrial metabolic stress and reduced anti-inflammatory adipocyte signaling as a consequence of reduced CHOP protein turnover.

Non aqua non igni locis pluribus utimur quam amicitia. Cicerone, Marco Tullio (106-43 a.C.) (De amicitia: VI, 32)

Insulin resistance is a major contributor to the neuroplasticity deficits observed in patients with metabolic disorders. However, the relative contribution of peripheral versus central insulin resistance in the development of neuroplasticity deficits remains equivocal. To distinguish between peripheral and central insulin resistance, we developed a lentiviral vector containing an antisense sequence selective for the insulin receptor (LV-IRAS). We previously demonstrated that intra-hippocampal injection of this vector impairs synaptic transmission and hippocampal-dependent learning and memory in the absence of peripheral insulin resistance. In view of the increased risk for the development of neuropsychiatric disorders in patients with insulin resistance, the current study examined depressive and anxiety-like behaviors, as well as hippocampal structural plasticity in rats with hippocampal-specific insulin resistance. Following hippocampal administration of either the LV-control virus or the LV-IRAS, anhedonia was evaluated by the sucrose preference test, despair behavior was assessed in the forced swim test, and anxiety-like behaviors were determined in the elevated plus maze. Hippocampal neuron morphology was studied by Golgi-Cox staining. Rats with hippocampal insulin resistance exhibited anxiety-like behaviors and behavioral despair without differences in anhedonia, suggesting that some but not all components of depressive-like behaviors were affected. Morphologically, hippocampal-specific insulin resistance elicited atrophy of the basal dendrites of CA3 pyramidal neurons and dentate gyrus granule neurons, and also reduced the expression of immature dentate gyrus granule neurons. In conclusion, hippocampal-specific insulin resistance elicits structural deficits that are accompanied by behavioral despair and anxiety-like behaviors, identifying hippocampal insulin resistance as a key factor in depressive illness.

Background: International data on the epidemiology, ventilation practice, and outcomes in patients undergoing abdominal robotic-assisted surgery (RAS) are lacking. The aim of the study was to assess the incidence of postoperative pulmonary complications (PPCs), and to describe ventilator management after abdominal RAS. Methods: This was an international, multicentre, prospective study in 34 centres in nine countries. Patients ≥18 yr of age undergoing abdominal RAS were enrolled between April 2017 and March 2019. The Assess Respiratory Risk in Surgical Patients in Catalonia (ARISCAT) score was used to stratify for higher risk of PPCs (≥26). The primary outcome was the incidence of PPCs. Secondary endpoints included the preoperative risk for PPCs and ventilator management. Results: Of 1167 subjects screened, 905 abdominal RAS patients were included. Overall, 590 (65.2%) patients were at increased risk for PPCs. Meanwhile, 172 (19%) patients sustained PPCs, which occurred more frequently in 132 (22.4%) patients at increased risk, compared with 40 (12.7%) patients at lower risk of PPCs (absolute risk difference: 12.2% [95% confidence intervals (CI), 6.8–17.6%]; P

International audience; Background: The PARIS risk score (PARIS-rs) and percutaneous coronary intervention complexity (PCI-c) predict clinical and procedural residual ischemic risk following PCI. Their accuracy in patients undergoing unprotected left main (ULM) or bifurcation PCI has not been assessed.Methods: The predictive performances of the PARIS-rs (categorized as low, intermediate, and high) and PCI-c (according to guideline-endorsed criteria) were evaluated in 3,002 patients undergoing ULM/bifurcation PCI with very thin strut stents.Results: After 16 (12-22) months, increasing PARIS-rs (8.8% vs. 14.1% vs. 27.4%, p < .001) and PCI-c (15.2% vs. 11%, p = .025) were associated with higher rates of major adverse cardiac events ([MACE], a composite of death, myocardial infarction [MI], and target vessel revascularization), driven by MI/death for PARIS-rs and target lesion revascularization/stent thrombosis for PCI-c (area under the curves for MACE: PARIS-rs 0.60 vs. PCI-c 0.52, p-for-difference < .001). PCI-c accuracy for MACE was higher in low-clinical-risk patients; while PARIS-rs was more accurate in low-procedural-risk patients. ≥12-month dual antiplatelet therapy (DAPT) was associated with a lower MACE rate in high PARIS-rs patients, (adjusted-hazard ratio 0.42 [95% CI: 0.22-0.83], p = .012), with no benefit in low to intermediate PARIS-rs patients. No incremental benefit with longer DAPT was observed in complex PCI.Conclusions: In the setting of ULM/bifurcation PCI, the residual ischemic risk is better predicted by a clinical risk estimator than by PCI complexity, which rather appears to reflect stent/procedure-related events. Careful procedural risk estimation is warranted in patients at low clinical risk, where PCI complexity may substantially contribute to the overall residual ischemic risk.

Aims The key role of inflammation in the pathogenesis of coronary artery disease (CAD) is an urgent call for innovative treatments. Several trials have proposed colchicine as a therapeutic option for secondary prevention in CAD patients but its utilization is hampered by fears about drug-related adverse events (DAEs) and conflicting evidences. The aim of this meta-analysis was to consolidate evidence on the efficacy and safety of colchicine for secondary prevention in patients with CAD. Methods and results A systematic search in electronic bibliographic databases of Medline, Scopus, Embase, and the Cochrane Library was performed to identify randomized controlled trials (RCTs) assessing the cardiovascular effects of colchicine in CAD patients, compared with placebo. Outcomes of interest were the occurrence of major adverse cardiovascular and cerebrovascular events (MACCE) and DAEs. Estimates were pooled using inverse-variance random-effects model. A total of 11 RCTs, including 12 869 patients, were identified as eligible. A total of 6501 patients received colchicine, while 6368 received placebo. After a median follow-up of 6 months (interquartile range, 1–16), patients receiving colchicine had a lower risk of MACCE [6% vs. 8.8%, relative risk (RR) = 0.67, 95% confidence interval (CI) 0.56–0.80, I2 = 19%], myocardial infarction (3.3% vs. 4.3%, RR = 0.76, 95% CI 0.61–0.96, I2 = 17%), coronary revascularization (2.9% vs. 4.2%, RR = 0.61, 95% CI 0.42–0.89, I2 = 40%), stroke (0.4% vs. 0.9%, RR = 0.48, 95% CI 0.30–0.77, I2 = 0%), hospitalization for cardiovascular cause (0.9% vs. 2.9%, RR = 0.32, 95% CI 0.12–0.87, I2 = 0%). Colchicine was associated with an increased risk of gastrointestinal DAEs (11% vs. 9.2%, RR = 1.67, 95% CI 1.20–2.34, I2 = 76%), myalgia (18% vs. 16%, RR = 1.16, 95% CI 1.02–1.32, I2 = 0%) and DAEs-related discontinuation (4.1% vs. 3%, RR = 1.54, 95% CI 1.02–2.32, I2 = 65%). However, gastrointestinal DAEs and discontinuation may be prevented with a lower daily dose. Colchicine did not increase the risk of cardiovascular death (0.7% vs. 1%, RR = 0.73, 95% CI 0.45–1.21, I2 = 14%), all-cause death (2% vs. 1.9%, RR = 1.01, 95% CI 0.71–1.43, I2 = 16%), or other DAEs. Conclusions The use of colchicine in patients with CAD is safe and efficacious for MACCE prevention.

OBJECTIVE Outcomes of complex percutaneous coronary interventions (PCIs) in older patients are still debated. The aim of the study was to evaluate clinical outcomes of Octogenarian patients treated with ultrathinstents on left main or on coronary bifurcations, compared with younger patients. METHODS All consecutive patients presenting a critical lesion of an unprotected left main (ULM) or a bifurcation and treated with very thin stents were included in the RAIN (veRy thin stents for patients with left mAIn or bifurcatioN in real life) registry and divided into octogenarians group (OG, 551 patients) and nonoctogenarians (NOGs, 2,453 patients). Major adverse cardiovascular event (MACE), a composite end point of all-cause death, nonfatal myocardial infarction (MI), target lesion revascularization (TLR), and stent thrombosis (ST), was the primary endpoint, while MACE components, cardiovascular (CV) death, and target vessel revascularization (TVR) were the secondary ones. RESULTS Indication for PCI was acute coronary syndrome in 64.7% of the OG versus 53.1% of the NOG. Severe calcifications and a diffuse disease were significantly more in OG. After a follow-up of 15.2 ± 10.3 months, MACEs were higher in the OG than in the NOG patients (OG 19.1% vs. NOG 11.2%, p

Background The clinical impact of stent strut thickness in coronary bifurcation lesions in small vessels has not been assessed in a real-world population. Methods and results All 506 patients enrolled in the RAIN study, undergoing PCI in a vessel with a diameter 2.5 mm or less were retrospectively evaluated and divided into two groups according to stent strut thickness: 74 μm (n = 206) versus 81 μm (n = 300); 87.1% of the lesions involved bifurcations. TLF [defined as a composite of myocardial infarction (MI) and target lesion revascularization (TLR)] was the primary endpoint, with MACE (a composite of death, MI and TLR), its components and stent thrombosis the secondary endpoint. After 16 (14-18) months, a lower incidence of TLF (4.3 vs. 9.8%, P = 0.026) and ST (1.0 vs. 3.0%, P = 0.042) was seen in the 74 μm group, whereas MACE occurred in 60 of 506 patients, with no statistical difference between the two groups (9.7 vs. 13.3%, P = 0.070). At multivariate analysis, chronic renal failure increased the risk of TLF while thinner strut was an independent protective factor (hazard ratio 0.51, CI 0.17-0.85, P = 0.005). Conclusion In this real-world population, patients being treated for small vessels lesions with thinner strut stents had lower rates of TLF, MI and ST.

Exercise restriction is a nonpharmacological treatment of pericarditis that could reduce symptoms by slowing heart rate (HR). Beta-blockers allow pharmacological control of HR. Aim of this paper is to explore the possible efficacy of beta-blockers to improve control of symptoms in patients with pericarditis. We analyzed consecutive cases with pericarditis referred to our center. Beta-blockers were prescribed on top of standard anti-inflammatory therapy in symptomatic patients (chest pain and palpitations) with rest HR75 beats/min. The primary end point was the persistence of pericardial pain at 3 weeks. The secondary end point was the occurrence of recurrent pericarditis at 18 months. Propensity score matching was used to generate 2 cohorts of 101 patients with and without beta-blockers with balanced baseline features. A clinical and echocardiographic follow-up was performed at 3 weeks, 1, 3, 6 months and then every 12 months. A total of 347 patients (mean age 53 years, 58% females, 48% with a recurrence, 81% with idiopathic/viral etiology) were included. Among them, 128 patients (36.9%) were treated with beta-blockers. Peak C-reactive protein values were correlated with heart rate on first observation (r=0.48, p0.001). Using propensity-score matched cohorts, patients treated with beta-blockers had a lower frequency of symptoms persistence at 3 weeks (respectively 4% vs. 14%; p = 0.024) and a trend towards a reduction of recurrences at 18 months (p = 0.069). In conclusion the use of beta-blockers on top of standard anti-inflammatory therapies was associated with improved symptom control.

Clinical studies indicate that obese individuals have an increased risk of developing co-morbid depressive illness and that these patients have reduced responses to antidepressant therapy, including selective serotonin reuptake inhibitors (SSRIs). Obesity, a condition of chronic mild inflammation including obesity-induced neuroinflammation, is proposed to contribute to decreases in synaptic concentrations of neurotransmitters like serotonin (5HT) by decreasing 5HT synthesis in the dorsal raphe nucleus (DRN) and/or affecting 5HT reuptake in DRN target regions like the hippocampus. In view of these observations, the goal of the current study was to examine inflammatory markers and serotonergic dynamics in co-morbid obesity and depression. Biochemical and behavioral assays revealed that high-fat diet produced an obesity and depressive-like phenotype in one cohort of rats and that these changes were marked by increases in key pro-inflammatory cytokines in the hippocampus. In real time using fast scan cyclic voltammetry (FSCV), we observed no changes in basal levels of hippocampal 5HT; however responses to escitalopram were significantly impaired in the hippocampus of obese rats compared to diet resistant rats and control rats. Further studies revealed that these neurochemical observations could be explained by increases in serotonin transporter (SERT) expression in the hippocampus driven by elevated neuroinflammation. Collectively, these results demonstrate that obesity-induced increases in neuroinflammation adversely affect SERT expression in the hippocampus of obese rats, thereby providing a potential synaptic mechanism for reduced SSRI responsiveness in obese subjects with co-morbid depressive illness.

Background About 40% of patients undergoing transcatheter aortic valve replacement (TAVR) have a history of atrial fibrillation (AF) and an additional 10% develop AF after TAVR. However, there is paucity of data regarding the optimal antithrombotic regimen following TAVR in patients with a clinical indication for oral anticoagulants (OAC). Purpose To compare the prognostic impact of OAC plus at least one antiplatelet agent (APT) versus OAC therapy alone in patients undergoing TAVR. Methods We systematically searched the literature for studies evaluating the comparative efficacy and safety of OAC + APT versus OAC alone in TAVR. Random-effect meta-analysis was performed comparing clinical outcomes between the two groups. All-cause mortality and cardiovascular mortality were the efficacy outcomes. Stroke and major bleeding, defined as Bleeding Academic Research Consortium bleeding types 3 to 5, constituted the safety outcome. Results Overall, 398 titles and abstracts were identified through database searching. Four observational studies were selected, for a total of 1929 patients. After a median follow-up of 18.5 months (IQR 11.3–29.3), OAC + APT increased major bleeding events compared to OAC alone (OR=1.79; 95% CI 1.21–2.66; P=0.004) with no difference in stroke (OR 01.02; 95% CI 0.52–2.01; P=0.95), all-cause mortality (OR=1.07; 95% CI 0.78–1.47; P=0.66) and cardiovascular mortality (OR=1.08; 95% CI 0.79–1.47; P=0.62). Conclusion A combination strategy of OAC + APT provides increased risk of bleeding compared to OAC therapy alone in patients undergoing TAVR with similar outcomes in terms of stroke, all-cause mortality and cardiovascular mortality; therefore, when feasible, it should be advised not to add APT on top of OAC therapy in patients without other clinical indications for APT treatment. Funding Acknowledgement Type of funding source: None

Introduction Atrioventricular blocks (AVBs) are a rare complication of Tako-Tsubo syndrome (TTS). Acute management of these patients is still a matter of debate since the long-term outcomes are difficult to predict and a complete recovery after PPM implantation may occur. Methods A critical review of current literature focusing on PPM implantation time in this patients' cohort was performed after a patient with TTS and AVB received a PPM in our medical center with a subsequent complete recovery in one month. Results Twenty-four case-reports of TTS-related AVBs were collected. A total of five patients went through a complete AV conduction recovery within few days, while of nineteen patients receiving a PPM during hospitalization, three showed a complete recovery within one to three months and one after two years. In six cases an electrophysiology (EP) study was performed to assess the functional nature of the AVB, resulting in four supra-Hisian blocks and two infra-Hisian blocks. In the supra-Hisian group there was a conduction recovery in three cases in a period from few days to one month while only one patient didn't improve at three-months. On the other hand, in the infra-Hisian group only one patient recovered AV conduction after two years. Conclusion Infra-Hisian and supra-Hisian blocks appear to have different outcomes with the latter more likely to develop a faster recovery. EP study could be a useful tool for clinicians during decision-making process and a wait-and-see strategy may be considered to avoid unnecessary PPM implantations. Funding Acknowledgement Type of funding source: None

Background Clinical benefits of FFR (Fraction Flow Reserve) driven CABG (Coronary Artery Bypass Graft) remain to be established. Methods All randomized controlled trials (RCTs) and observational studies with multivariable adjustement were included. MACE (Major Adverse Cardiac Events) was the primary end point, while its single components (death, myocardial infarction, and total vessel revascularization [TVR]) along with number of anastomoses, on pump procedures and graft occlusion at angiographic follow-up were the secondary ones. Each analysis was stratified for RCTs versus observational studies. Results Four studies (two RCTs and two observational) were included, enrolling 983 patients, 542 angio-guided and 441 FFR-guided. Mean age was 68.45 years, 79% male, with a mean EuroSCORE I of 2.7. Coronary lesions were located in 37% of patients in the left anterior descending artery, 32% in the circumflex artery, and 26% in the right coronary artery. After a mean follow-up of 40 months, risk of MACE did not differ (OR 0.86 [0.63-1.18]) as that of all cause death (OR 0.86 [0.59-1.25]), MI (OR 0.57 [0.30-1.11]) and TVR (OR 1.10 [0.65-1.85]). FFR-driven CABG reduced on-pump procedures (OR 0.58 [0.35-0.93]) and number of anastomoses (-0.40 [-0.80: -0.01]) while incidence of graft occlusion at follow-up did not differ (OR 0.59 [0.30-1.15], all CI 95%). Conclusion Fraction flow reserve driven CABG reduced the number of anastomoses and of on-pump procedures without increasing risk of MACE and without reducing graft occlusion at angiographic follow-up. ID CRD42020211945.

Background Evidence-based recommendations about anticoagulation in acute type B aortic dissection (TBAD) are completely missing, but there is a diffuse conviction that it could prevent the healing process of the dissected aorta’s false lumen. However, several clinical conditions may lead to the necessity to start anticoagulant therapy among patients with acute type B aortic dissection, ranging from atrial fibrillation to more complicated clinical scenarios and the correct management in this kind of patients is still an open issue. Case presentation We are presenting a 51-years-old man with multi-infarct encephalopathy referred to us for an acute TBAD and a first diagnosis of ischemic cardiomyopathy complicated by left ventricular (LV) thrombus formation. Coronary angiography revealed a critical stenosis of left anterior descending artery (LAD) treated with drug-eluting stent deployment. The patient was addressed to triple antithrombotic therapy with acetylsalicylic acid, clopidogrel and warfarin with target INR 2.0–2.5. After 6 months, computed tomography angiography revealed the stability of the dissection flap. Cardiac magnetic resonance imaging, however, confirmed the persistence of a small thrombotic formation in LV apex, thus double antithrombotic therapy with warfarin and clopidogrel was instituted. The patient remained asymptomatic during the follow-up period but was advised to suspend his job and physical activities. Conclusion Current guidelines do not discuss anticoagulant therapy in the setting of TBAD and large randomized trials are lacking. Despite it is generally considered unsafe to administer anticoagulants in patients with TBAD, we present a case in which triple antithrombotic therapy was well tolerated and did not lead to progression of the intimal flap after 6 months.

Insulin induces long-term depression (insulin-LTD) in the CA1 region of the rat juvenile hippocampus. This insulin-LTD may be due in part to internalization of the GluA2 subunit of the AMPA receptor (AMPAR) events that haven’t been studied in the mature rat hippocampus. In our studies, we used hippocampal preparations from juvenile (14 - 25 days) and mature (60 - 90 days) rats to assess insulin modulation of CA1 synaptic transmission and AMPAR trafficking and phosphorylation. Using field potential electrophysiology, we observed that insulin induced LTD in the juvenile hippocampus (as previously reported) in the presence and absence of phosphoinositide 3-kinase (PI3K) activity, but produced no significant long-term changes in the mature hippocampus in the presence of PI3K activity. Interestingly, during PI3K inhibition, insulin did produce LTD in the mature hippocampus. Additionally, insulin induced a long-term decrease in plasma membrane expression of the GluA2 and GluA1 subunits of the AMPAR in the juvenile, but not mature hippocampus. Furthermore, there was a long-term decrease in GluA1 phosphorylation at Serine 845 in the juvenile, but not mature hippocampus. These data reveal that insulin modulation of synaptic plasticity and AMPAR modulation within the hippocampus is age-dependent, suggesting that insulin-regulated behaviors may also show age-dependence. These findings are important largely due to the increased use of insulin as a therapeutic throughout the lifespan. Our data suggest that additional work should be done to determine how this use of insulin throughout different stages of life might affect synaptic function and development.

Insulin receptors (IRs) are expressed in discrete neuronal populations in the central nervous system, including the hippocampus. To elucidate the functional role of hippocampal IRs independent of metabolic function, we generated a model of hippocampal-specific insulin resistance using a lentiviral vector expressing an IR antisense sequence (LV-IRAS). LV-IRAS effectively downregulates IR expression in the rat hippocampus without affecting body weight, adiposity, or peripheral glucose homeostasis. Nevertheless, hippocampal neuroplasticity was impaired in LV-IRAS–treated rats. High-frequency stimulation, which evoked robust long-term potentiation (LTP) in brain slices from LV control rats, failed to evoke LTP in LV-IRAS–treated rats. GluN2B subunit levels, as well as the basal level of phosphorylation of GluA1, were reduced in the hippocampus of LV-IRAS rats. Moreover, these deficits in synaptic transmission were associated with impairments in spatial learning. We suggest that alterations in the expression and phosphorylation of glutamate receptor subunits underlie the alterations in LTP and that these changes are responsible for the impairment in hippocampal-dependent learning. Importantly, these learning deficits are strikingly similar to the impairments in complex task performance observed in patients with diabetes, which strengthens the hypothesis that hippocampal insulin resistance is a key mediator of cognitive deficits independent of glycemic control.

Elevated level of ammonia in the blood, defined as hyperammonemia, is feasible to cause neurological symptoms when crossing the blood-brain barrier. The most frequent and studied cause of hyperammonemia is liver failure. Nevertheless, other less frequent and known etiologies must be considered. Urinary tract infection caused by urea-splitting bacteria, despite being unusual in pediatric patients, must be taken into account. We report a pediatric patient with severe acute encephalopathy and high levels of ammonia in blood. After ruling out other causes of hyperammonemia, it was assumed secondary to urinary tract infection by Corynebacterium riegelii, a ureasplitting bacteria. General treatment for hyperammonemic encephalopathy was established, as well as specific treatment with antibiotics. The patient evolved favorably.

& Abstract: The fibromyalgia syndrome (FMS) is character-ized by chronic and widespread musculoskeletal pain andsoreness accompanied by sleep disorders, chronic fatigue andaffective disorders. FMS is often associated with other formsof immuno-rheumatic diseases. Although FMS pathophysiol-ogyisstillnotfullyunderstood,anumberofneuroendocrine,neurotransmission and neurosensitive disorders might gen-erate a mechanism for the elicitation of pain by “centralsensitization,” which is common to many other painfulconditions. The present case describes the success of atherapeutic scheme, which associates two different pharma-cological classes, anticonvulsants and new-generation an-tidepressants, when FMS complicates a rare pathology calledCogan’s syndrome. The association of two drugs mightnoticeably affect the molecular mechanisms of difficult pain,thus solving painful conditions of multifactorial origin. &Key Words: Cogan’s syndrome, fibromyalgia, rheumato-logical diseases, pain management, antidepressant, anticon-vulsant, drugs association

Ectonucleotidases and the nucleotide metabolism have been implicated as important regulators in diabetes disease. We evaluated the ectonucleotidase activities and biochemical parameters in blood serum of streptozotocin (STZ)-induced diabetic rats submitted a physical training protocol. We observed a raise in ATP, ADP, AMP and p-Nph-5'-TMP hydrolysis rate and in the levels of cholesterol and triglycerides in rat blood serum, after 30 days of diabetes induction. However, in serum of rats submitted a physical training protocol by forced swimming, both the nucleotide hydrolysis rate and the lipids levels returned to the control values. Considering that diabetes leads to multiple pathophysiological alterations, the modulations observed in ectonucleotidase activities may be part of the events involved in these alterations. Then the physical training is a very important way to control the vascular alterations developed in diabetes.

Background: Microvolt T-wave alternans (MTWA) has been proposed as a predictor of the risk of ventricular tachyarrhythmias (VT) and sudden cardiac death (SCD). Aim of this study was to perform a systematic review of the literature and a meta-analysis of MTWA in primary prevention patients with ischemic and nonischemic cardiomyopathy. Methods: The positive predictive value (PPV), negative predictive value (NPV), and relative risk (RR) of MTWA in predicting death, cardiac death, and SCD during follow-up were reported. Results: Fifteen studies involving 5681 patients (mean age 62 years, mean ejection fraction 32%) were included. The summary PPV during the average 26-month follow-up was 14% (95% CI: 13–15); NPV was 95% (95% CI: 94–96), and the univariate RR was 2.35 (95% CI: 1.68–3.28). The predictive value of MTWA was similar in patients with ischemic and nonischemic cardiomyopathy. The average RR for SCD or VT events of an abnormal MTWA was 2.40, similar to that for cardiac death. When we grouped the studies together depending upon whether beta-blockers were withheld prior to MTWA screening, the beta-blockers group showed an RR of 5.88. By contrast, the group in which beta-blocker therapy was withheld had an RR of 1.63. Conclusion: A positive MTWA determined an approximately 2.5-fold higher risk of cardiac death and life-threatening arrhythmia and showed a very high NPV both in ischemic and nonischemic patients. An abnormal MTWA test was associated with a 5-fold increased risk for cardiac mortality in the low-indeterminate group and about a 6-fold increased risk in beta-blockers group. Ann Noninvasive Electrocardiol 2011;16(4):388–402

Epidemiological studies estimate that greater than 60% of the adult US population may be categorized as either overweight or obese and there is a growing appreciation that obesity affects the functional integrity of the central nervous system (CNS). We recently developed a lentivirus (LV) vector that produces an insulin receptor (IR) antisense RNA sequence (IRAS) that when injected into the hypothalamus selectively decreases IR signaling in hypothalamus, resulting in increased body weight, peripheral adiposity and plasma leptin levels. To test the hypothesis that this obesity/hyperleptinemic phenotype would impair hippocampal synaptic transmission, we examined short term potentiation (STP) and long term potentiation (LTP) in the hippocampus of rats that received the LV-IRAS construct or the LV-Control construct in the hypothalamus (hypo-IRAS and hypo-Con, respectively). Stimulation of the Schaffer collaterals elicits STP that develops into LTP in the CA1 region of hypo-Con rats; conversely, hypo-IRAS rats exhibit STP that fails to develop into LTP. To more closely examine the potential role of hyperleptinemia in these electrophysiological deficits, hypo-IRAS were subjected to mild food restriction paradigms that would either: 1) prevent the development of the obesity phenotype; or 2) reverse an established obesity phenotype in hypo-IRAS rats. Both of these paradigms restored LTP in the CA1 region and reversed the decreases in the phosphorylated/total ratio of GluA1 Ser845 AMPA receptor subunit expression observed in the hippocampus of hypo-IRAS rats. Collectively, these data support the hypothesis that obesity impairs hippocampal synaptic transmission and support the hypothesis that these deficits are mediated through the impairment of hippocampal leptin activity.

An increased activity of the hypothalamo-pituitary-adrenal axis resulting in exaggerated glucocorticoid secretion has been repeatedly described in patients with diabetes mellitus and in animal models of this disease. However, it has been pointed out that experimental diabetes is accompanied by a decreased glucocorticoid response to ACTH stimulation. Because previous studies from our laboratory demonstrate the involvement of nitric oxide (NO) in the modulation of corticosterone production, present investigations were designed to evaluate 1) the impact of streptozotocin (STZ)-induced diabetes on the adrenocortical nitrergic system and 2) the role of NO in the modulation of adrenal steroidogenesis in STZ-diabetic rats. Four weeks after STZ injection, increased activity and expression levels of proteins involved in l-arginine transport and in NO synthesis were detected, and increased levels of thiobarbituric acid reactive species, carbonyl adducts, and nitrotyrosine-modified proteins were measured in the adrenocortical tissue of hyperglycemic rats. An impaired corticosterone response to ACTH was evident both in vivo and in adrenocortical cells isolated from STZ-treated animals. Inhibition of NO synthase activity resulted in higher corticosterone generation in adrenal tissue from STZ-treated rats. Moreover, a stronger inhibition of steroid output from adrenal cells by a NO donor was observed in adrenocortical Y1 cells previously subjected to high glucose (30 mm) treatment. In summary, results presented herein indicate an inhibitory effect of endogenously generated NO on steroid production, probably potentiated by hyperglycemia-induced oxidative stress, in the adrenal cortex of STZ-treated rats.

In the central nervous system (CNS) insulin mediates a variety of effects including feeding, metabolism and cognition. The cognitive enhancing effects of insulin are proposed to be mediated through activation of insulin receptors in the hippocampus, an important integration center for learning and memory in the mammalian brain. Since less is known regarding insulin signaling events in the hippocampus, the aim of the current study was to determine whether insulin stimulates similar signaling cascades and GLUT4 translocation in the rat hippocampus as has been described in peripheral tissues. Intracerebroventricular administration of insulin increases hippocampal insulin levels and also stimulates the phosphorylation of Akt in a time-dependent manner. Insulin also stimulates the translocation of GLUT4 to hippocampal plasma membranes in a time course that mirrors the increases in glucose uptake observed during the performance of hippocampal-dependent tasks. Insulin stimulated phosphorylation of Akt and translocation of GLUT4 were blocked by pre-treatment with the PI3-kinase inhibitor LY294002. Confocal immunofluorescence determined that insulin stimulated phosphorylation of Akt was localized to neurons and colocalized with the insulin receptor and GLUT4 in the rat hippocampus, thereby identifying the functional anatomical substrates of insulin signaling in the hippocampus. These results demonstrate that insulin-stimulated translocation of GLUT4 to the plasma membrane in the rat hippocampus occurs via similar mechanisms as described in peripheral tissues and suggests that insulin mediated translocation of GLUT4 may provide a mechanism through which hippocampal neurons rapidly increase glucose utilization during increases in neuronal activity associated with hippocampal-dependent learning.

Central nervous system (CNS) complications resulting from diabetes is a problem that is gaining more acceptance and attention. Recent evidence suggests morphological, electrophysiological and cognitive changes, often observed in the hippocampus, in diabetic individuals. Many of the CNS changes observed in diabetic patients and animal models of diabetes are reminiscent of the changes seen in normal aging. The central commonalities between diabetes-induced and age-related CNS changes have led to the theory of advanced brain aging in diabetic patients. This review summarizes the findings of the literature as they relate to the relationship between diabetes and dementia and discusses some of the potential contributors to diabetes-induced CNS impairments.

Objective To evaluate the presence of antisperm antibodies in testicular cancer patients 1 month after orchiectomy and before radiotherapy or chemotherapy. Design Clinical study. Setting Department of andrology and seminology at a university hospital. Patient(s) One hundred ninety patients with testicular cancer. Intervention(s) Determination of semen parameters and autoimmune reaction evaluated on the sperm surface and in blood serum. Main Outcome Measure(s) Autoimmune reaction on the sperm surface by the direct immunobead test (IBT), and in blood serum by the indirect IBT and the gelatin agglutination test (GAT), was evaluated 1 month after orchiectomy and before beginning chemotherapy or radiotherapy. Result(s) Of the 190 patients, 11 (5.8%) were positive for antisperm antibody by GAT. On indirect IBT, 3 of the 11 GAT-positive patients were positive to IgG class only, with values of 22%, 24%, and 40%. Of the 11 GAT-positive patients, 4 showed no antibody bound to the sperm surface, and 3 were positive to IgG class only (28%, 21%, and 38%), with binding exclusively on the tail. Direct IBT could not be performed in the remaining 4 patients. Conclusion(s) Our data support the hypothesis that testicular cancer might not be a possible cause of antisperm autoimmunization and infertility.

Background: A growing body of evidence suggests that neuroinflammation, which is characterized by infiltration of immune cells, activation of mast cells and glial cells, and production of inflammatory mediators in the peripheral and central nervous systems, has an important role in the induction and maintenance of chronic pain. These findings support the notion that new therapeutic opportunities for chronic pain might be based on anti-inflammatory and pro-resolving mediators that act on immune cells, in particular mast cells and glia, to mitigate or abolish neuroinflammation. Among anti-inflammatory and pro-resolving lipid mediators, palmitoylethanolamide (PEA) has been reported to down-modulate mast cell activation and to control glial cell behaviors. Objective: The aim of this study was to perform a pooled meta-analysis to evaluate the efficacy and safety of micronized and ultra-micronized palmitoylethanolamide (PEA) on pain intensity in patients suffering from chronic and/or neuropathic pain. Study Design: Pooled data analysis consisting of double-blind, controlled, and open-label clinical trials. Methods: Double-blind, controlled, and open-label clinical trials were selected consulting the PubMed, Google Scholar, and Cochrane databases, and proceedings of neuroscience meetings. The terms chronic pain, neuropathic pain, and micronized and ultra-micronized PEA were used for the search. Selection criteria included availability of raw data and comparability between tools used to diagnose and assess pain intensity. Raw data obtained by authors were pooled in one database and analyzed by the Generalized Linear Mixed Model. The changes in pain over time, measured by comparable tools, were also assessed by linear regression post-hoc analysis and the Kaplan-Meier estimate. Twelve studies were included in the pooled meta-analysis, 3 of which were double-blind trials comparing active comparators vs placebo, 2 were open-label trials vs standard therapies, and 7 were open-label trials without comparators. Results: Results showed that PEA elicits a progressive reduction of pain intensity significantly higher than control. The magnitude of reduction equals 1.04 points every 2 weeks with a 35% response variance explained by the linear model. In contrast, in the control group pain, reduction intensity equals 0.20 points every 2 weeks with only 1% of the total variance explained by the regression. The Kaplan-Meier estimator showed a pain score ≤ 3 in 81% of PEA treated patients compared to only 40.9% in control patients by day 60 of treatment. PEA effects were independent of patient age or gender, and not related to the type of chronic pain. Limitations: Noteworthy, serious adverse events related to PEA were not registered and/or reported in any of the studies. Conclusion: These results confirm that PEA might represent an exciting, new therapeutic strategy to manage chronic and neuropathic pain associated with neuroinflammation. Key words: Chronic pain, neuropathic pain, neuroinflammation, astrocytes, glia, mast cells, microglia, micronized and ultra-micronized palmitoylethanolamide

Recent studies have demonstrated that adult humans have substantial amounts of functioning brown adipose tissue (BAT). Since BAT has been implicated as an anti-obese and anti-diabetic tissue, it is important to understand the signaling molecules that regulate BAT function. There has been a link between insulin signaling and BAT metabolism as deletion or pharmaceutical inhibition of insulin signaling impairs BAT differentiation and function. Tribbles 3 (TRB3) is a pseudo kinase that has been shown to regulate metabolism and insulin signaling in multiple tissues but the role of TRB3 in BAT has not been studied. In this study, we found that TRB3 expression was present in BAT and overexpression of TRB3 in brown preadipocytes impaired differentiation and decreased expression of BAT markers. Furthermore, TRB3 overexpression resulted in significantly lower oxygen consumption rates for basal and proton leakage, indicating decreased BAT activity. Based on previous studies showing that deletion or pharmaceutical inhibition of insulin signaling impairs BAT differentiation and function, we assessed insulin signaling in brown preadipocytes and BAT in vivo. Overexpression of TRB3 in cells impaired insulin-stimulated IRS1 and Akt phosphorylation, whereas TRB3KO mice displayed improved IRS1 and Akt phosphorylation. Finally, deletion of IRS1 abolished the function of TRB3 to regulate BAT differentiation and metabolism. These data demonstrate that TRB3 inhibits insulin signaling in BAT, resulting in impaired differentiation and function.

Background: In the rat hippocampus, the predominate glutamate transporters are GLT-1 and its recently identified isoform, GLT-1b. Chronic restraint stress increases GLT-1b expression throughout the hippocampus while more selectively increasing GLT-1 expression in the CA3 region. These studies suggest that GLT-1b expression is regulated by stress levels of glucocorticoids (GCs) and GLT-1 expression is regulated by stress-induced increases in extracellular glutamate levels in the CA3 region. Methods: In order to differentiate between the actions of GCs and glutamate, we examined GLT-1 isoform expression in adrenalectomized (ADX) rats and rats exposed to stress levels of GCs. Results: ADX rats revealed no significant differences in GLT-1b mRNA or protein levels compared to sham-operated controls or ADX rats given GC replacement. However, rats exposed to stress levels of GCs exhibited increases in GLT-1b protein expression in the CA3 region and the dentate gyrus. GLT-1 mRNA expression was increased by ADX, increases that were inhibited by GC replacement. Similarly, stress levels of GCs increased GLT-1 protein expression throughout the hippocampus. Conclusions: Taken together, these data indicate that GLT-1b protein expression is regulated by stress levels of GCs while the regulation of GLT-1 mRNA and protein expression provides another example of the biphasic actions of GCs in the central nervous system.

Aims. The aim of this study was to study hemodynamic modifications during thoracic and abdominal stop-flow regional chemotherapy and to evaluate the need for routine hemodynamic monitoring during such kind of procedures. Methods. Thirty patients, aged 17–67 years, ASA physical status II–III, scheduled for thoracic (group A, n=15), and abdominal (group B, n=15) stop-flow regional chemotherapy were enrolled. Heart rate (HR), electrocardiogram lead I and V5, end tidal carbon dioxide (ETCO2), arterial oxygen saturation (SaO2), systolic, diastolic and mean arterial pressure (SBP, DBP, MAP), mean pulmonary arterial pressure (MPAP), pulmonary capillary wedge pressure (PCWP), central venous pressure (CVP), cardiac output (CO), stroke volume (SV), stroke index (SI), systemic vascular resistance (SVR), pulmonary vascular resistance (PVR), left cardiac work (LCW), right cardiac work (RCW), left cardiac work index (LCWI), right cardiac work index (RCWI), cardiac index (CI), and body O2 consumption (VO2) were recorded. Results. After aortic and inferior vena cava endovascular occlusion (T1), a significant reduction of CO and SV, associated with an increase of CVP, MAP, PAPM and PCWP were observed. A concomitant reduction of CI and increase of SVR and PVR were registered. The VO2 was significantly reduced compared to basal values in both groups. After deflating aortic and vena cava balloons (T2), CO, SV and CI increased with respect to basal value (p

Oxidative stress and modulation of anti-oxidant enzymes may contribute to the deleterious consequences of diabetes mellitus and to the effects of chronic (i.e. 21 day) stress in the CNS. We therefore compared the effects of short- and long-term exposure to diabetes-induced hyperglycemia, restraint stress and the combined effects of restraint stress and diabetes upon parameters of oxidative stress in the rat hippocampus. Whereas 7 days of restraint stress or hyperglycemia, or the combination, produced similar increases in oxidative stress markers 4-hydroxy-2-nonenal (HNE) and malondialdehyde (MDA) throughout the hippocampus, 21 days of stress or hyperglycemia did not increase these markers in the dentate gyrus. In contrast, Ammon's horn still showed elevated levels of these lipid peroxidation products, especially in diabetic rats subjected to 21 days of restraint stress. The expression of two anti-oxidant enzymes, copper/zinc superoxide dismutase (Cu/Zn-SOD) and manganese SOD, was also differentially regulated by stress and hyperglycemia in a time- and region-specific manner in the rat hippocampus. Although long-term stress decreased both SOD isoforms, diabetes increased Cu/Zn-SOD expression in DG with or without 21 days of repeated stress. These increases may account for the finding that protein-conjugated HNE and MDA levels returned to control levels between 7 days and 21 days of hyperglycemia or the combination of diabetes and stress. These results suggest that while other anti-oxidant pathways may account for decreases in oxidative stress in the long-term stress paradigm, increases in Cu/Zn-SOD expression may contribute to the region-specific attenuation of oxidative stress in the diabetic rat hippocampus.

The Na+,K(+)-ATPase plays a key role in the regulation of ion fluxes and membrane repolarization in the CNS. We have studied glucocorticoid effects on biosynthesis of the Na+,K(+)-ATPase and on ouabain binding in the ventral horn of the spinal cord using intact rats, adrenalectomized (ADX) rats, and ADX rats receiving dexamethasone (ADX+DEX) during 4 days. Cryostat sections from spinal cords were incubated with a 35S-oligonucleotide coding for the alpha 3-subunit or a 3H-cDNA coding for the beta 1-subunit of the Na+,K(+)-ATPase using in situ hybridization techniques. In ventral horn motoneurons, grain density per cell and grain density per area of soma for both probes were slightly reduced in ADX rats but significantly increased in the ADX+DEX group, using ANOVA and the Bonferroni's test. Statistical analysis of frequency histograms of neuronal densities further indicated a significant shift to the right for intact rats compared with ADX rats for both probes. Concomitantly, [3H]ouabain binding to membrane preparations from ventral horns was reduced in ADX rats and restored to normal by DEX administration. No effect of adrenalectomy or DEX treatment was obtained in the dorsal horn. In conclusion, glucocorticoids positively modulate the mRNA for the alpha 3-subunit and the beta 1-subunit of the Na+,K(+)-ATPase and recover ouabain binding to normal values. The increments of the synthesis and activity of an enzyme affecting membrane repolarization and synaptic neurotransmission are consistent with the alleged stimulatory effect of glucocorticoids on spinal cord function.

1. Previous work demonstrated that estradiol (E2) treatment prevented the abnormal response to stress and the reduction of glucocorticoid receptors (GR) in hippocampus from aging male rats. The mechanisms originating these effects were unknown.

Galanin is a peptide widely distributed in the hypothalamic-pituitary axis. In the female rat pituitary, galanin is mainly present in lactotrophs, where it regulates their secretion and proliferation. Galanin expression is increased in oestrogen-induced prolactinomas, and it has been proposed that oestrogen effects on lactotroph function and proliferation could be mediated by galanin. Previous studies from our laboratory demonstrated that the synthetic progestin levonorgestrel antagonizes pituitary tumorigenesis of rats given oestrogen, reducing the number of proliferating cells and increasing cell death by nonapoptotic mechanism(s). To elucidate the role of galanin in levonorgestrel effects on the tumours, we examined galanin and prolactin mRNA and peptide expression in prolactinomas of rats receiving the progestin. Levonorgestrel reduced the pituitary weight and serum prolactin concentrations in oestrogen-treated rats. Galanin mRNA expression (determined by in situ hybridization), and the number of galanin expressing cells (determined by immunocytochemistry) were also reduced by the progestin in tumour-bearing rats. However, neither prolactin mRNA content, nor the number of prolactin-expressing cells, were modified by levonorgestrel treatment of oestrogen-receiving rats. The present study suggests that levonorgestrel controls pituitary growth by diminishing galanin expression. In contrast, changes in serum prolactin concentration seem to be more related to the reduction in tumour size, since the reduction in galanin expression was not large enough to regulate prolactin mRNA expression or the percentage of lactotrophs.

Hexachlorobenzene (HCB) is a polyhalogenated aromatic hydrocarbon widely distributed in the environment. In animal testing, HCB has been shown to be a reproductive toxin. Previous investigations of the effects of HCB on ovarian function have yielded equivocal results. Thus, the effects of chronic administration of HCB (1 g kg -1 body wt.) on the ovary and pituitary hormone levels, hepatic and uterine oestradiol receptors, ovarian histopathological changes and oestrus cycle characteristics were investigated in spontaneously cycling rats. Our data demonstrate that HCB treatment, under the conditions of the present study, reduced circulating levels of oestradiol and prolactin without differences in serum concentrations of progesterone. Follicle-stimulating hormone serum levels were elevated. Hexachlorobenzene treatment resulted in irregularity of cycles, characterized mainly as prolonged periods of oestrus with a reduced number of ova recovered. In addition, HCB administration resulted in significantly decreased uterine nuclear oestrogen receptor levels. Histopathological examination revealed degenerative changes of the ovarian follicles and germinal epithelium and increased numbers of atresic follicles.

Aging is associated with a disturbance in the regulation of the hypothalamic-pituitary-adrenal axis (HPA) and reduced levels of glucocorticoid receptors (GR) in the hippocampus. To compensate for these effects, we have investigated whether estrogen therapy normalized the HPA response to stress and GR in hippocampus and paraventricular (PVN) nucleus. Young (3–4 months) and old (20 months) male Sprague-Dawley rats were bled by tail cut in the basal state and following ether stress. While basal and ether-stimulated levels of plasma corticosterone (CORT) were similar in the two groups, old animals presented a delayed termination of the response to ether stress. A dexamethasone inhibition test carried out in old animals, showed a failure to completely block plasma CORT after ether stimulation. Furthermore, in old rats GR-immunoreactive levels were reduced in CA1-CA2 hippocampal subfields and subiculum, while normal levels were obtained in CA3-CA4 and PVN. We observed that prolonged estrogen treatment (6 weeks) of old rats normalized the termination of the stress response, restored dexamethasone inhibition of plasma CORT, and increased GR immunoreactivity in CA1 and CA2 hippocampal subfields and subiculum. The results suggest that estrogen treatment enhanced the glucocorticoid feedback signal by increasing GR in hippocampus, and corrected the disturbances in HPA axis regulation. These animal experiments may be important to elucidate the effects of estrogenic on the hippocampal and HPA dysfunction associated with aging and Alzheimer’s disease in humans.

Glucocorticoids (GC) and mineralocorticoids (MC) have profound regulatory effects upon the central nervous system (CNS). Hormonal regulation affects several molecules essential to CNS function. First, evidences are presented that mRNA expression of the alpha3 and beta1-subunits of the Na,K-ATPase are increased by GC and physiological doses of MC in a region-dependent manner. Instead, high MC doses reduce the beta1 isoform and enzyme activity in amygdaloid and hypothalamic nuclei, an effect which may be related to MC control of salt appetite. The alpha3-subunit mRNA of the Na,K-ATPase is also stimulated by GC in motoneurons of the injured spinal cord, suggesting a role for the enzyme in GC neuroprotection. Second, we provide evidences for hormonal effects on the expression of mRNA for the neuropeptide arginine vasopressin (AVP). Our data show that GC inhibition of AVP mRNA levels in the paraventricular nucleus is sex-hormone dependent. This sexual dimorphism may explain sex differences in the hypothalamic-pituitary-adrenal axis function between female and male rats. Third, steroid effects on the astrocyte marker glial fibrillary acidic protein (GFAP) points to a complex regulatory mechanism. In an animal model of neurodegeneration (the Wobbler mouse) showing pronounced astrogliosis of the spinal cord, in vivo GC treatment down-regulated GFAP immunoreactivity, whereas the membrane-active steroid antioxidant U-74389F up-regulated this protein. It is likely that variations in GFAP protein expression affect spinal cord neurodegeneration in Wobbler mice. Fourth, an interaction between neurotrophins and GC is shown in the injured rat spinal cord. In this model, intensive GC treatment increases immunoreactive low affinity nerve growth factor (NGF) receptor in motoneuron processes. Because GC also increases immunoreactive NGF, this mechanism would support trophism and regeneration in damaged tissues. In conclusion, evidences show that some molecules regulated by adrenal steroids in neurons and glial cells are not only involved in physiological control, but additionally, may play important roles in neuropathology.

Chronic exposure of F344 rats to diethylstilbestrol (DES) induces pituitary tumors (DES-T) composed of proliferating lactotrophs. Presently, we studied the effect of progestins on parameters related to tumor growth and function, due to previous evidences of progesterone antagonism of pituitary tumorigenesis acting at pituitary and hypothalamic levels [Piroli, G., Grillo, C., Ferrini, M., Lux-Lantos, V. and De Nicola, A. F., Antagonism by progesterone of diethylstilbestrol-induced pituitary tumorigenesis in Fischer 344 rats: Effects on sex steroid receptors and tyrosine hydroxylase mRNA, Neuroendocrinology, 1996, 63, 530-539]. In search of a quantitatively more important effect, animals bearing DES-T were treated with synthetic progestins. Competition assays using DES-T as source of progestin receptors indicated that levonorgestrel (LNG), gestodene and R5020 showed higher affinities (IC50 1-2 nM) than progesterone, norethisterone and medroxyprogesterone (IC50 10-25 nM). Treatment with LNG reduced DES-T weight by 45%, and serum PRL by one half. Small (monomeric) and big (polymeric) PRL increased 5- and 2.5-fold, respectively, in DES-T in comparison with pituitaries of ovariectomized (OVX) rats. However, LNG produced no changes indicating that synthesis and storage of PRL was conserved in rats receiving both hormonal treatments. DES induced a 15-fold increase in cell proliferation, measured as bromodeoxyuridine incorporation into cell nuclei, in comparison to OVX rats, while LNG treatment of DES-T bearing rats reduced this index by 72%. Electron microscopic images showed that LNG markedly reduced hypertrophy and hyperplasia of lactotropes, increasing the proportions of degenerating cells and cells of high electronic density with alterations of cytoplasmic organelles. However, histopathological signs of apoptosis were absent. Therefore, reduced cell proliferation and non-apoptotic cell death are part of the mechanisms employed by progestins to antagonize tumorigenesis at the pituitary level. The results may open a new therapeutic strategy for treatment of PRL secreting adenoma in humans.

The neuropeptides arginine vasopressin (AVP) and oxytocin (OT) have been implicated in the genesis of hypertension due to deoxycorticosterone acetate (DOCA)-salt treatment of uninephrectomized rats. In this work, we studied if DOCA treatment of intact rats in doses arousing a salt appetite (a prehypertensive state), modulated mRNA for AVP and OT in the hypothalamus. Male Sprague-Dawley rats were offered both tap water and 3% NaCl in separate bottles and received vehicle or subcutaneous injections of 10 mg DOCA on alternate days for 7 days (4 injections) or 17 days (9 injections). They developed a preference for 3% NaCl solutions 24–48 h after treatment. Brain slices from rats killed on the 8th or 18th day were exposed to 35S-labeled probes encoding prepro-AVP mRNA or OT mRNA, respectively. Expression of these mRNAs was measured in the magnocellular and parvocellular divisions of the paraventricular nucleus (PVN) and magnocellular cells of the supraoptic nucleus (SON). No changes were obtained in neuropeptide mRNA levels in the parvocellular division of the PVN between control and the two groups of DOCA-treated rats. However, DOCA-treated animals presented an increased number of grains per cell for AVP mRNA in the magnocellular division of the PVN and in magnocellular cells of the SON, as shown by group mean comparisons and frequency histograms. No changes were detected for OT mRNA. In a second series of studies, control or DOCA-treated rats were offered 3% NaCl or water as the only choice. Animals drinking 3% NaCl showed increased AVP and OT mRNA levels, whether they received DOCA or not. However, AVP mRNA levels in both nuclei were higher in DOCA-treated rats drinking 3% NaCl than in controls drinking salt solution. In comparison, control and DOCA-treated rats drinking water showed lower levels of AVP mRNA. OT mRNA levels in the SON remained unchanged in the same groups. The results suggest that in the magnocellular cells of the PVN and SON, increments in AVP mRNA are obtained following increments in salt intake produced by either mineralocorticoid treatment or exclusive salt drinking. In rats offered salt solution and water to drink, DOCA effects on AVP mRNA developed before changes occurred in serum sodium levels. Because combined DOCA + salt treatment induced a higher response in terms of AVP mRNA expression, we suggest that AVP could be a target of the central effects of the mineralocorticoid.

In physiological doses, mineralocorticoids (MC) normalize the high salt intake developed after adrenalectomy. We have studied whether this effect of MC is accompanied by changes in the mRNA of neuronal α 3 and β 1 subunits of the (Na,K)-ATPase because this enzyme could by a mediator of MC action in target cells. We employed [ 35 S]oligonucleotide probes for the mentioned subunits hybridized to brain sections from adrenalectomized rats and adrenalectomized rats receiving aldosterone (ALDO) during 4 days. Using t -test statistics to measure differences in mean levels of grain density, and the Kolmogorov–Smirnov non-parametric test applied to frequency histograms, we showed that ALDO increased the α 3 subunit mRNA in the septum medialis, preoptic area medialis, caudate-putamen, periventricular gray substance, amygdala lateralis, hippocampal subfields CA1 to CA4 and the gyrus dentatus. Significant increases for the β 1 subunit mRNA were found in periventricular gray substance, the CA1–CA4 hippocampal subfields and gyrus dentatus. Therefore, the salt-suppression effect of MC was accompanied by coordinate increases in (Na,K)-ATPase α 3 and β 1 subunit mRNA in the hippocampus, gyrus dentatus and periventricular gray substance, whereas in other regions the stimulatory effect was exclusive of the α 3 subunit mRNA only. The results suggest that the enzyme could be a target of ALDO action not only in areas related to salt appetite control (amygdala, preoptic area) but also in brain regions subserving other functions of the MC.

1. Arginine vasopressin (AVP) is synthesized in specific brain regions including the magnocellular and parvocellular divisions of the paraventricular nucleus (PVN). Whereas magnocellular AVP responds to osmotic stimuli and functions mainly--although not exclusively--as an antidiuretic hormone, that produced in the parvocellular region controls the hypothalamus-pituitary-adrenal (HPA) axis, in conjunction with CRF. 2. In view of the reported sex differences in control of the HPA axis, we studied if these also pertain to AVP mRNA in the PVN of ovariectomized-estrogenized female rats and male rats determined by in situ hybridization. AVP mRNA was measured in intact rats, adrenalectomized (ADX) rats and ADX receiving dexamethasone (DEX) of both sexes. 3. Computerized autoradiography showed that in both sexes, AVP mRNA levels in the parvocellular division of the PVN increased after adrenalectomy and decreased following DEX. However, the reduction by DEX was more pronounced in female rats. No changes were found for the magnocellular region. Grain counting analysis of the medial-medial (MMP) and medial-lateral (MLP) subdivisions of the parvocellular region showed that the average number of grains per cell area in the MMP region of adrenally intact female rats was higher than that in males. However, in females there was no clear-cut effect of adrenalectomy on AVP mRNA levels, although the reduction after DEX treatment was again greater than that in male rats. Frequency histograms constructed by plotting the number of cells vs the number of grains per area substantiated the enhanced glucocorticoid negative control of AVP mRNA in the MMP and MLP of female rats. 4. The results indicated a sexual dimorphism in the glucocorticoid-dependent plasticity of AVP mRNA levels in the PVN. Because AVP mRNA expression differs between sexes under basal levels, after adrenalectomy, and after DEX treatment, these plastic changes may differentially condition the response to stress. Taking into consideration that stress and AVP may play a role in neurogenic hypertension, the possibility of sexual dimorphisms in AVP control may be important to assess the role of sex hormones in stress and steroid-derived hypertension.

It is known that chronic exposure of F344 rats to diethylstilbestrol (DES) induces prolactin (PRL)-secreting pituitary tumors composed of proliferating mammotropic cells. In the present work, we studied the effects of progesterone (P4) on several parameters stimulated in the pituitary tumors (DES-T), such as nuclear estrogen receptors (NE2R), cytosolic progestin receptors (CP4R) and serum PRL. Additionally, we have measured in hypothalamus the mRNA levels for tyrosine hydroxylase (TH), the rate-limiting enzyme for synthesis of dopamine, the main PRL-inhibitory factor. We found that pellet implantation of P4 during 1 month significantly reduced weight, ligand binding to NE2R and CP4R and serum PRL in the tumorous glands. Reductions in sex steroid receptor binding were due to changes in Bmax without changes in Kd, as observed after Scatchard plot analysis. Receptor binding data, therefore, suggests a pituitary site of action of P4. TH mRNA expression was studied in tuberoinfundibular dopaminergic (TIDA) neurons by in situ hybridization techniques employing a 35S-labeled oligonucleotide probe. Mean number of grains/cell decreased significantly in DES-T, an effect partly reversed by P4 treatment. Frequency histograms were constructed by plotting the number of cells versus the number of grains/cell and examined by x2 test and analysis of residuals. We found that DES-T presented significantly more cells with less grains whereas in control glands, P4-treated rats and DES-T receiving P4, cells with a higher grain number prevailed. These results suggest that in addition to a direct pituitary effect, P4 may also antagonize DES-induced tumorigenesis acting on mRNA for TH and presumably on the activity of TIDA neurons of the hypothalamus. The use of DES-T as a model for hyperprolactinemia may allow further assessment of P4 effects in pituitary adenomas in humans.

The effect of glucocorticoids on (Na+K)ATPase mRNA synthesis was studied in 19 brain areas of adrenalectomized (ADX) rats untreated or receiving dexamethasone (DEX). For in situ hybridization, we employed a [35S]oligonucleotide probe for the alpha 3-subunit isoform, and a [3H]cDNA coding for the beta 1-subunit of the enzyme. Mean levels of grain density for the alpha 3 subunit mRNA of DEX-treated rats were significantly higher by a 't' test in medial septum, amygdala lateralis (AL) and medialis (AME), gyrus dentatus, CA4 hippocampal area, substantia nigra and periventricular gray, compared to untreated rats. For the beta 1-subunit, mean levels after DEX were significantly higher in AL and lateral preoptic area. In addition, the Kolmogorov-Smirnov test applied to frequency histograms of neuronal densities indicated a coordinate increase in alpha 3 and beta 1-subunit mRNA expression for the CA2 subfield and preoptic area medialis (POA MED). We conclude that (1) glucocorticoids are positive modulators of (Na+K)ATPase mRNA; (2) analysis of frequency histograms suggests that glucocorticoids promote in a few regions (AL, POA MED, CA2 subfield) a coordinate increase in the biosynthesis of the alpha 3 and beta 1-subunit mRNA. In 11 other areas stimulation occurs for one subunit mRNA only, whereas 5 areas were insensitive to glucocorticoid effects on this enzyme.

We previously reported a reduction of glucocorticoid receptors (GCR) in diethylstilbestrol-induced pituitary tumors (DES-T) in rats. Presently, we found that bromocriptine (BROM) treatment increased the levels of GCR in DES-T, demonstrated by steroid binding assays and immunocytochemistry using a monoclonal antibody against the type II GCR. We also found that the high content of nuclear estradiol receptors in the adenomata and the elevated levels of PRL in serum of DES-T were significantly reduced after BROM treatment. In parallel studies, PRL secretion was measured after administration of ether stress. In controls, serum PRL markedly increased after ether and this effect was blunted by prior dexamethasone (DEX) administration, due to the steroid negative feedback on PRL secretion. In animals with DES-T, ether stress had no effect on serum PRL, and the inhibition by DEX was lost unless they received BROM, which restored the negative feedback of DEX on serum PRL. Although increases of PRL titers in pituitary tumors may be due to estrogenic stimulation of lactotroph proliferation and function, coupled to absent dopaminergic inhibition on these cells, other mechanisms are possible. In this respect, inefficient steroid negative feedback on PRL synthesis due to down-regulation of GCR may contribute to hyperprolactinemia. This mechanism is supported from the restoration of GCR and steroid negative feedback on serum PRL by treatment of tumor-bearing rats with BROM.