Dark papillary muscles sign: a novel prognostic marker for cardiac magnetic resonance

OBJECTIVES

The prognostic role of left ventricular (LV) papillary muscle abnormalities in patients with preserved LV systolic ejection fraction (LVEF) is unknown. We sought to evaluate the prognosis role of LV papillary muscle abnormalities by CMR in patients with ventricular arrhythmias, preserved LVEF with no cardiac disease.

METHODS

A total of 391 patients with > 500/24 h premature ventricular complexes and/or with non-sustained ventricular tachycardia (NSVT), preserved LVEF, and no cardiac disease were enrolled. Different features of LV papillary muscles were considered: supernumerary muscles, papillary thickness, the attachment, late gadolinium enhancement (LGE). Dark-Paps was defined as end-systolic signal hypointensity of both papillary muscles in early post-contrast cine CMR images. Mitral valve prolapse, mitral annular disjunction (MAD), and myocardial LGE were considered.

RESULTS

Dark-Paps was found in 79 (20%) patients and was more frequent in females. It was associated with higher prevalence of mitral valve prolapse and MAD. During a median follow-up of 2534 days, 22 hard cardiac events occurred. At Kaplan-Meier curve analysis, patients with Dark-Paps were at higher risk of events than those without (p < 0.0001). Dark-Paps was significantly associated with hard cardiac events in all the multivariate models. Dark-Paps improved prognostic estimation when added to NSVT (p = 0.0006), to LGE (p = 0.005) and to a model including NSVT+LGE (p = 0.014). Dark-Paps allowed a significant net reclassification when added to NSVT (NRI 0.30, p = 0.03), to LGE (NRI 0.25, p = 0.04), and to NSVT + LGE (NRI 0.32, p  = 0.02).

CONCLUSIONS

In LV papillary muscles, Dark-Paps is a novel prognostic marker in patients with ventricular arrhythmias and preserved ejection fraction.

KEY POINTS

• Papillary muscle abnormalities are seen in patients with ventricular arrhythmias and preserved left ventricular ejection fraction. • Early post-contrast hypointensity of papillary muscles in end-systolic cine images (Dark-Paps) is a novel prognostic marker in patients with ventricular arrhythmias and preserved ejection fraction. • Dark-Paps had an additive prognostic role over late gadolinium enhancement and non-sustained ventricular tachycardia.

338 PREVALENCE AND PERSISTENCE OF HYPOVITAMINOSIS D AMONG ITALIAN PATIENTS WITH MYOCARDIAL INFARCTION

Background

Hypovitaminosis D is common in the Italian population and has a comparable effect to diabetes mellitus on survival after an acute myocardial infarction (AMI). We aimed to evaluate if the prevalence of hypovitaminosis D changed over time, considering also frequent lockdowns in the last years due to COVID-19 pandemic.

Methods

According to the year of enrollment, we divided our cohort of 1042 patients hospitalized for AMI, into three groups (group 1 with 368 patients enrolled from 2014 till 2016, group 2 with 470 patients enrolled in the period from 2017 till 2019, and group 3 including 204 patients enrolled in the last three years, from 2020 till 2022) and evaluate whether the concentration of vitamin D changed in the last decade.

Results

The median concentration of vitamin D in our cohort of patients with AMI was 18.2 (11.48-25.73) ng/ml). Throughout the three groups (2014-2016, 2017-2019, 2020-2022), the median plasma vitamin D showed a trend toward an increase (17.3 (10.33–24.2) ng/ml, 18.95 (11.6–26.73) ng/ml, and 19.05 (12.5–27.3) ng/ml respectively), which was significant between the group 1 vs 2 and 3 (p = 0.033 and p = 0.004, respectively), while between the group 2 and 3 did not. Despite the trend of increase, the percentage of patients with hypovitaminosis D in each group remained high (61.4%, 53.8% and 52.0% respectively). As expected, samples taken between May and September have significantly higher vitamin D values compared to ones taken from October to April for each group (the group 1: 21.80 (15.55–31.23) ng/ml vs 15.8 (9.22–23.98) ng/ml, p &lt; 0.0001; the group 2: 22.05 (14.10–30.98) ng/ml vs 16.50 (11.03–23.90) ng/ml, p &lt; 0.0001); the group 3: 20.00 (11.90–26.90) ng/ml vs 16.30 (9.75–22.30) ng/ml, p = 0.001).

Conclusions

There has been a trend of increasing vitamin D values over the years, but hypovitaminosis D remains frequent. During the pandemic, vitamin D levels did not decrease due to frequent lockdowns, possibly due to media awareness that emphasized the significance of vitamin D administration against viral infection.

738 A RARE CASE OF UNICUSPID AORTIC VALVE WITH SEVERE STENOSIS AND REGURGITATION: CLINICAL PRESENTATION AND MANAGEMENT

A 19-year-old Pakistani migrant, who arrived in our country on foot, presented at emergency department with angina and worsening dyspnoea on exertion. The patient reported an unclear history of aortic valve disease.

Clinical examination revealed a 6/6L systolic murmur with thrill. The electrocardiogram showed sinus rhythm and signs of left ventricular hypertrophy. Chest X-ray reported cardiomegaly and signs of congestion. Troponin I HS was mildly elevated (39 ng/L, n.v. &lt; 18 ng/L).

The patient was admitted to our Cardiology department. Transthoracic echocardiography revealed a mildly dilated left ventricle (LV), with severe hypertrophy, normal kinetics and systolic function (EF 63%), dilated ascending aorta (diam. 41 mm) and severe aortic steno-insufficiency. Transesophageal echocardiography was then performed, revealing a highly calcified, unicuspid unicommissural aortic valve with severe stenosis and regurgitation. A separate origin of left coronary ostia was also documented.

The patient was referred to urgent cardiac surgery. A modified Bentall procedure (mechanical valve and prosthetic conduit) was performed with reimplantation of the coronary ostia. Due to a post-surgical complete atrioventricular block, a dual-chamber pacemaker (DDD) was implanted.

Follow-up echocardiography showed reduction of LV volumes and wall thickness and normal prosthetic function.

Unicuspid aortic valve is a very rare congenital disease, with a prevalence of about 0.02% in the adult population and is frequently associated with ascending aorta dilatation. The treatment is aortic valve replacement. Complete atrioventricular block can occur after surgery, requiring cardiac pacing.

A 20-year experience in cardiac tumors: a single center surgical experience and a review of literature

INTRODUCTION

Cardiac tumors are rare and heterogeneous entities which still remain a diagnostic and therapeutic challenge. The treatment for most cardiac tumors is prompt surgical resection. We sought to provide an overview of surgical results from a series of consecutive patients treated at our tertiary care center during almost a 20-year experience.

METHODS AND RESULTS

In this single center study, 55 consecutive patients with diagnosis of cardiac tumor underwent surgical treatment from January 2002 to April 2021. Of these, 23 (42%) were male and the mean age was 62 ± 12 years. Fifteen (27%) patients were symptomatic at the time of the diagnosis, mostly for dyspnea and palpitations. The most frequent benign cardiac tumor was myxoma (32; 58%), occurring mainly in the left atrium (31; 97%). Pleomorphic sarcoma was the most frequent primary malignant cardiac tumor (4; 7%), mainly located in the ventricles (1; 25% in the left ventricle; 2; 50% in the right ventricle). In all cases of benign tumors surgery was successful with no relapses. Two (50%) pleomorphic sarcomas showed subsequent relapses. After a median follow-up of 44 months, 15 (27%) patients died. Although malignant tumors presented a limited survival, benign tumors showed a very good prognosis.

CONCLUSION

Cardiac tumors require a multidisciplinary approach to guarantee a prompt diagnosis and appropriate treatment. In our surgical experience, outcome after surgery of benign tumors was excellent, while malignant tumors had poor prognosis despite radical surgery.

Toward a diagnostic CART model for Ischemic heart disease and idiopathic dilated cardiomyopathy based on heart rate total variability

Diagnosis of etiology in early-stage ischemic heart disease (IHD) and dilated cardiomyopathy (DCM) patients may be challenging. We aimed at investigating, by means of classification and regression tree (CART) modeling, the predictive power of heart rate variability (HRV) features together with clinical parameters to support the diagnosis in the early stage of IHD and DCM. The study included 263 IHD and 181 DCM patients, as well as 689 healthy subjects. A 24 h Holter monitoring was used and linear and non-linear HRV parameters were extracted considering both normal and ectopic beats (heart rate total variability signal). We used a CART algorithm to produce classification models based on HRV together with relevant clinical (age, sex, and left ventricular ejection fraction, LVEF) features. Among HRV parameters, MeanRR, SDNN, pNN50, LF, LF/HF, LFn, FD, Beta exp were selected by the CART algorithm and included in the produced models. The model based on pNN50, FD, sex, age, and LVEF features presented the highest accuracy (73.3%). The proposed approach based on HRV parameters, age, sex, and LVEF features highlighted the possibility to produce clinically interpretable models capable to differentiate IHD, DCM, and healthy subjects with accuracy which is clinically relevant in first steps of the IHD and DCM diagnostic process.

Incidence of acute myocarditis and pericarditis during the coronavirus disease 2019 pandemic: comparison with the prepandemic period

BACKGROUND

Myocarditis and pericarditis have been proposed to account for a proportion of cardiac injury during SARS-CoV-2 infection. The impact of COVID-19 the pandemic on the incidence of this acute inflammatory cardiac disease was not systematically evaluated.

AIM

To examine the incidence and prevalence of inflammatory heart disorders prior to and during the COVID-19 pandemic.

METHODS

We compared the incidence and prevalence of acute inflammatory heart diseases (myocarditis, pericarditis) in the provinces of Pisa, Lucca and Livorno in two time intervals: prior to (PRECOVID, from 1 June 2018 to 31 May 2019) and during the COVID-19 pandemic (COVID, from 1 June 2020 to May 2021).

RESULTS

Overall 259 cases of inflammatory heart disease (myocarditis and/or pericarditis) occurred in the areas of interest. The annual incidence was of 11.3 cases per 100 000 inhabitants. Particularly, 138 cases occurred in the pre-COVID, and 121 in the COVID period. The annual incidence of inflammatory heart disease was not significantly different (12.1/100 000 in PRECOVID vs 10.3/100 000 in COVID, P = 0.22). The annual incidence of myocarditis was significantly higher in PRECOVID than in COVID, respectively 8.1/100 000/year vs. 5.9/100 000/year (P = 0.047) consisting of a net reduction of 27% of cases. Particularly the incidence of myocarditis was significantly lower in COVID than in PRECOVID in the class of age 18-24

Les représentations de la maladie : choix des outils de mesure et applications dans le champ du cancer

Objectif : Dresser un bilan des outils quantitatifs disponibles pour mesurer les représentations de la maladie et analyser leur utilisation empirique auprès de patients atteints de cancer.

Matériel et méthodes : Revue de la littérature.

Résultats : Sept outils de mesure des représentations de la maladie existent dont un spécifique au cancer. L’Illness Perception Questionnaire est utilisé dans 29 des 33 études retenues.

Conclusion : Associer ces échelles avec des méthodes reposant sur des approches davantage centrées sur le contexte socioculturel semble à privilégier.

413 Challenges in the field of cardiac tumours: the surgical experience of Trieste

Aims

Cardiac tumors are rare and heterogeneous entities which still remain a diagnostic and therapeutic challenge. The treatment for most cardiac tumors is prompt surgical resection. We sought to provide an overview of surgical results from a series of consecutive patients treated at our tertiary centre during almost a 20-year experience.

Methods and results

In this single centre study, 55 consecutive patients with cardiac tumor underwent surgical treatment from January 2002 to April 2021. Of these, 42% of patients were male and the mean age was 62 ± 12 years. Almost 27% of patients were symptomatic at the time of the diagnosis, mostly for dyspnoea and palpitations. The most frequent benign cardiac tumor was myxoma (58% of cases), occurring mainly in the left atrium (97%). Pleomorphic sarcoma was the most frequent primary malignant cardiac tumour (7.2% of cases), mainly located in the ventricles (25% left ventricle; 50% right ventricle). In all cases of benign tumors surgery was successful with no relapses. In 50% of cases of pleomorphic sarcoma relapses were observed during follow-up. After a median follow-up of 44 months, 15 (27%) patients died. While malignant tumors presented a limited survival, benign tumours showed a very good prognosis.

Conclusions

Cardiac tumours require a multidisciplinary work-up to guarantee a prompt diagnosis and appropriate treatment. In our surgical experience, the prognosis of benign tumours was excellent, while malignant tumours had poor outcomes despite radical surgery.

324 Unilateral pulmonary artery agenesis with controlateral embolism: a double vascular trouble

Methods and results

A 60-year-old male patient underwent coronary angiography (CA) for a non-ST segment elevation myocardial infarction (NSTEMI). CA revealed significant multivessel disease. Both internal mammary arteries (AMI) were patent, with right IMA markedly larger than the left IMA. The exam revealed also an abnormal branch arising from the proximal right coronary artery extending backwards, likely to the right lung. Pre-operative chest radiograph demonstrated asymmetry of the two hemithoraces with slight elevation of the right hemidiaphragm, small ipsilateral lung, and mediastinal shift towards the right. The patient underwent urgent CABG surgery. Myocardial revascularization was successfully performed using both AMI and one saphenous vein segment. The postoperative course was complicated by respiratory failure requiring prolonged mechanical ventilation. A chest computed tomography angiography was performed, revealing complete absence of the right pulmonary artery and a left lower lobe segmental pulmonary embolism. Furthermore, blood in the hypoplastic right lung was supplied by multiple collaterals arising from RCA and right IMA. Intravenous heparin was started with clinical improvement. Two weeks later, a lung scintigraphy was performed, ruling out perfusion defects. The patient was discharged home on oral anticoagulation with warfarin.

Conclusions

Unilateral pulmonary artery agenesis (UPAA) is an uncommon congenital anomaly of the great vessels. Despite the absence of the pulmonary artery, blood supply of ipsilateral lung is provided by systemic collaterals originating from bronchial, intercostal, internal mammary, and sub-diaphragmatic arteries. More rarely, these collaterals may arise from the coronary arteries with different implications, ranging from asymptomatic condition to myocardial ischaemia and infarction. In our case, the condition was previously asymptomatic. The occurrence of pulmonary embolism contributed to worsen the ventilation–perfusion mismatch, explaining the respiratory failure during the postoperative period.

A case of primary cardiac sarcoma with an acute presentation: The role of multimodality imaging

The case highlights the value of contrast echocardiography in raising clinical suspicion of malignancy, allowing a diagnostic work-up and the treatment of the primitive heart tumors.

Prevalence and predictors of persistent sinus rhythm after elective electrical cardioversion for atrial fibrillation

AIMS

To evaluate the prevalence and predictors of persistent sinus rhythm in a recent cohort of unselected patients undergoing electrical cardioversion for atrial fibrillation.

METHODS

We enrolled all consecutive patients undergoing elective electrical cardioversion for atrial fibrillation between January 2017 and December 2018. We analysed baseline clinical and echocardiographic data as well as pharmacological antiarrhythmic therapy. Primary endpoint was the maintenance of sinus rhythm at 12 months after electrical cardioversion.

RESULTS

Of the 300 patients enrolled, 270 (90%) had successful electrical cardioversion and among them, 201 patients have 12-month follow-up data (mean age 70 ± 10 years; 74% men). At 12 months, only 45.7% were in sinus rhythm. Patients without sinus rhythm compared with persistent sinus rhythm at 12 months had a lower baseline left ventricle ejection fraction (LVEF) (49.1 ± 16 vs. 59.7 ± 9%, P = 0.02) and had more frequently a history of atrial fibrillation more than 12 months (55 vs. 34% P = 0.003). At the multivariate analysis, only the duration of the disease beyond 12 months (OR 0.26, 95% CI: 0.08-0.88, P = 0.032), LVEF (OR 1.06, 95% CI: 1.01-1.12, P = 0.012) and the presence of sinus rhythm at 1-month follow-up (OR 18.28, 95% CI: 3.3-100, P = 0.001) were associated with the probability of maintaining sinus rhythm at 12 months.

CONCLUSION

In unselected patients with atrial fibrillation undergoing elective electrical cardioversion, only 45.7% were in sinus rhythm at 12 months. The presence of sinus rhythm at 1-month follow-up emerged as an independent predictor of maintenance of sinus rhythm. This highlights that early re-evaluation of these patients appears useful for assessing longer term outcomes also from the perspective of a possible selective approach to ablation strategies.

Detection of subjects with ischemic heart disease by using machine learning technique based on heart rate total variability parameters

OBJECTIVE

Ischemic heart disease (IHD), in its chronic stable form, is a subtle pathology due to its silent behavior before developing in unstable angina, myocardial infarction or sudden cardiac death. The clinical assessment is based on typical symptoms and finally confirmed, invasively, by coronary angiography. Recently, heart rate variability (HRV) analysis as well as some machine learning algorithms like Artificial Neural Networks (ANNs) were used to identify cardiovascular arrhythmias and, only in few cases, to classify IHD segments in a limited number of subjects. The goal of this study was the identification of the ANN structure and the HRV parameters producing the best performance to identify IHD patients in a non-invasive way, validating the results on a large sample of subjects. Moreover, we examined the influence of a clinical non-invasive parameter, the left ventricular ejection fraction (LVEF), on the classification performance.

APPROACH

To this aim, we extracted several linear and non-linear parameters from 24h RR signal, considering both normal and ectopic beats (Heart Rate Total Variability), of 251 normal and 245 IHD subjects, matched by age and gender. ANNs using several different combinations of these parameters together with age and gender were tested. For each ANN, we varied the number of hidden neurons from 2 to 7 and simulated 100 times changing randomly training and test dataset.

MAIN RESULTS

The HRTV parameters showed significant greater variability in IHD than in normal subjects. The ANN applied to meanRR, LF, LF/HF, Beta exponent, SD2 together with age and gender reached a maximum accuracy of 71.8% and, by adding as input LVEF, an accuracy of 79.8%.

SIGNIFICANCE

The study provides a deep insight into how a combination of some HRTV parameters and LVEF could be exploited to reliably detect the presence of subjects affected by IHD.

Influence of ageing on circadian rhythm of heart rate variability in healthy subjects

BACKGROUND

The analysis of the circadian rhythm of heart rate variability (HRV) represents a relevant physiological tool to assess the vagal system. However, the influence of age (mostly >75 years) on HRV is not widely known.

AIMS

The aim of this study was to evaluate the influence of age on HRV, particularly in the elderly and to identify a model of this relationship. The study was carried out by examining linear and nonlinear parameters extracted from HRV, including individuals over 75 years for which there is no research available.

METHODS

Data from 140 healthy subjects were sex matched and divided into young (young group: 15-39 years old), adult (adult group: 40-64 years old) and senior (senior group: 65-90 years old) groups. 24-h Holter monitoring was used and several HRV parameters were extracted from time, and spectral and nonlinear analyses were examined.

RESULTS

Time-domain parameters, mainly standard deviation of the NN interval (SDNN) and number of successive differences of intervals which differ by more than 50 ms, presented significant differences between the young group and the other two groups during the 24-h period, while normalized spectral parameters (LFn, HFn and low frequency/high frequency), as well as nonlinear parameters, mainly β exponent and fractal dimension, showed significant difference between the senior group and the other two groups. All these parameters showed a similar circadian rhythm with significant differences between the mean day and night values, especially in young and adult group cohorts. Moreover, a parabolic relationship between these parameters and age was highlighted with an opposite trend over about 60 years compared with younger people.

CONCLUSION

A progressive physiological autonomic imbalance is present in ageing. The inverse trend in the relation between HRV parameters and age found in the senior group could be mainly due to a faster fluctuation of RR. This should be considered when studying changes in the cardiac autonomic nervous control.

Dry Eye Syndrome in Non-Exophthalmic Graves' Disease

BACKGROUND

The present study aims to assess qualitative and quantitative characteristics of tear film and corneal related impairment and to evaluate the quality of life in a cohort of non-exophthalmic Graves' disease (GD) patients.

METHODS

The series comprised 50 eyes from 25 newly diagnosed GD patients with no proptosis. As control group, 56 eyes of 28 thyroid disease-free subjects were enrolled.

RESULTS

The results of Schirmer I and II, break-up time, and Oxford scheme showed a significant difference between GD and controls. By ocular surface disease index (OSDI) questionnaire, eleven (44%) GD patients had normal ocular surface, while two (8%) had mild, four (16%) had moderate, and eight (32%) had severe dry eye. The mean score of the OSDI in the GD group was significantly (p < 0.001) higher with respect to the control group.

CONCLUSIONS

This study shows that the tear film and cornea are damaged in newly non-exophthalmic GD subjects.

Clinically-irrelevant positivity for serum proteinase 3-ANCA in HIV disease

Diagnosis of small-vessel vasculitides (granulomatosis with polyangiitis, microscopic polyangiitis, Churg-Strauss syndrome, and their localized forms) is aided by the detection of serum antineutrophil cytoplasmic antibodies (ANCA). However, serum ANCA positivity does not always mean vasculitis. Here, we report on a 61-year-old female patient with very high serum levels of proteinase 3 ANCA, marked hypergammaglobulinemia, low complement levels, and a 16-mm lung nodule on chest CT scan, who was referred to our Institution with a provisional diagnosis of possible granulomatosis with polyangiitis. On admission, history-taking disclosed two recent episodes of viral reactivation (namely, cytomegalovirus and Varicella-Zoster virus), while physical examination revealed lingual and nail involvement suggestive of Candida infection. An immunodeficiency disorder was eventually suspected. Search for antibodies against human immunodeficiency virus (HIV) 1 and 2 turned positive. Western blot analysis confirmed HIV infection. Thus, although ANCA detection may be helpful in diagnosing small-vessel vasculitis in the appropriate clinical scenario, screening for HIV infection should sometimes be considered to discriminate clinically irrelevant serum ANCA positivity.

Steatosis is the predictor of relapse in HCV genotype 3- but not 2-infected patients treated with 12 weeks of pegylated interferon-α-2a plus ribavirin and RVR

HCV genotypes 2- or 3-infected patients with a rapid virological response (RVR) to therapy with pegylated interferon and ribavirins who have a low viral load, noncirrhotic and nonobese may be considered for a shorter course of treatment. However, no studies have assessed host-viral factors associated with relapse in genotype 2 and 3 separately. Accordingly, we assessed whether 12 weeks of pegylated interferon and ribavirin was an optimized regimen for treatment of HCV genotype 2 and 3 with positive predictors of response. Power and sample size were a priori calculated and 96 consecutive chronic hepatitis C patients (53, genotype 2 and 43, genotype 3) without cirrhosis who were not obese and who achieved a RVR to therapy with peg-IFN-α-2a and ribavirin were enrolled. Fibrosis, steatosis, homeostatic model assessment-insulin resistance and HCV RNA were predefined variables to be evaluated in relapse. An intention-to-treat analysis was performed. SVR rates were 98% and 84% for genotype 2 and 3, respectively. Analysis of genotype 3 patients who had relapse showed a negative correlation with steatosis (P < 0.0001) and HCV RNA (P < 0.015). Multivariate analysis showed that steatosis was the independent predictor of relapse (OR, 0.988; 95% CI, 0.981-0.993; P < 0.001). Genotype 3 patients with steatosis had a relapse rate of 36.4% and 15.8% in those with high and low viral load, respectively, whereas there was no relapse in those without steatosis. In conclusion, a 12-week course of therapy is sufficient for patients without cirrhosis, not obese and infected with HCV genotype 2 achieve a RVR. This is not the case for genotype 3. Steatosis is the independent predictor of relapse. New therapeutic strategies are necessary for this subgroup of HCV genotype 3.

Microsomal triglyceride transfer protein (MTP) -493G/T gene polymorphism contributes to fat liver accumulation in HCV genotype 3 infected patients

(A) A reduced activity of microsomal triglyceride transfer protein (MTP), a key enzyme of assembly/secretion of lipoproteins, is related to HCV steatosis. Host genetic background may influence development of steatosis. The aim of the study was to investigate the association between MTP-493 G/T gene polymorphism, fat liver accumulation and fibrosis progression in HCV infected patients. A total of 102 naïve patients with liver biopsy proven chronic hepatitis C were evaluated for MTP-493 G/T gene polymorphism, HCV RNA, HCV genotype, HOMA-IR, serum adiponectin, TNF-alpha and serum lipid levels. HCV genotype 3 infected patients carrying the T allele of the MTP gene polymorphism showed higher degree of steatosis than those carrying GG genotype (3.45 +/- 0.37 vs 1.30 +/- 0.45, respectively; P < 0.001). MTP'T' allele carriers also had higher HCV RNA serum levels (P < 0.01) and hepatic fibrosis (P < 0.001). Irrespective of MTP genotype, patients with HCV genotype 3 had lower levels of cholesterol, ApoB, HDL and LDL. In HCV genotype non-3 infected patients no parameters were associated with MTP gene polymorphism. In conclusion the presence of T allele of MTP-493G/T gene polymorphism predisposes patients infested with HCV genotype 3 to develop higher degree of fatty liver accumulation.

Region-specific changes in the microanatomy of single dendritic spines over time might account for selective memory alterations in ageing hAPPsweTg2576 mice, a mouse model for Alzheimer disease

Tg2576 mice over-expressing human mutant APP (hAPPswe) show progressive impairments in hippocampal plasticity and episodic memory while fronto-striatal plasticity and procedural memory remain intact. Here we examine the status of synaptic connectivity in the hippocampus and the dorsolateral striatum (DLS) of 3- and 15-month-old Tg2576 and wild-type mice through the analysis of single dendritic spines microanatomy. We found that, in each region, all mice showed a global reduction in the size of spines as a function of age. Ageing mutants, however, exhibited smaller spines with shorter necks on CA1 pyramidal neurons but larger spines with longer necks on DLS spiny neurons compared to their age-matched wild-type controls. Our findings indicate that hippocampal and DLS dendritic spines in hAPPswe mutants undergo a different pattern of morphological changes over time and point to minor alterations in the microanatomy of DLS spines as a compensatory mechanism maintaining procedural abilities in the ageing mutants.

Hepatic steatosis and insulin resistance are associated with serum imbalance of adiponectin/tumour necrosis factor-alpha in chronic hepatitis C patients

BACKGROUND

Steatosis and insulin resistance (IR) have a pathogenic role in chronic hepatitis C (HCV). Adipocytokines balance modulates hepatic lipid content and IR.

AIM

To evaluate serum adipocytokines and relationship with virological, histological and metabolic parameters in chronic HCV.

METHODS

Adiponectin and tumour necrosis factor-alpha (TNF-alpha) levels, HCV genotypes, HCV-RNA, IR (HOMA-IR), body mass index and liver steatosis and fibrosis were assessed in 161 non-diabetic chronic HCV patients.

RESULTS

Chronic HCV patients with steatosis showed lower serum adiponectin levels and higher levels of TNF-alpha, HOMA, alanine aminotransferase, gamma-glutamiltransferase and Histological Activity Index (HAI) and fibrosis scores. Low adiponectin levels were independently associated with grades of steatosis and HOMA-IR. Higher tumour necrosis factor-alpha levels were observed in patients with low adiponectin levels. The extension of steatosis was inversely correlated with adiponectin levels. A correlation between grade of steatosis with HOMA-IR and fibrosis was observed. HCV genotype 3-infected patients showed lower adiponectin levels than those with other genotypes. An independent predictor of low adiponectin levels in genotype 3 infection was the extension of steatosis. Liver fibrosis score was associated with steatosis, HAI and age.

CONCLUSIONS

Chronic HCV patients with steatosis showed a serum adiponectin/TNF-alpha imbalance that is associated with IR. Reduced adiponectin levels may be involved in the pathogenesis of steatosis, which in turn accelerates progression of fibrosis in chronic HCV.

Strain Differences in Rewarded Discrimination Learning Using the Olfactory Tubing Maze

We trained BALB/c Byllco (C), CD-1, SV 129/SvPasCr1 (129 SV), C57BL/6 (B6) and DBA/2J (D2) mice using the olfactory tubing maze with the hope of gaining insight into behavioral genetics related to learning and memory processes. All strains of mice acquired the odor-reward associations using this new task except the D2 strain. The C, CD-1, and 129 SV consistently remembered the associations from the sixth 20-trial training session, reaching 80% +/- 5 correct responses in session seven. The B6 mice required one more session to reach 76%, while the D2 mice never learned the correct odor-reward associations. All mice learned the paradigm and the timing of the task, although the 129 SV mice decreased slower the inter-trial intervals across sessions. With this new task, D2 mice, with a deficit totally devoted to an impairment on learning and memory, can be used as a model of hippocampal dysfunction, in some respects like that observed in human amnesic patients whose selective hippocampal-dependent memory is deeply impaired. The high-scoring strains (C, CD-1, and 129 SV) seem to be ideal in this task to study a gene-targeting mutation postulated to reduce behavioral performance, and inversely, for D2 mice. The moderate-scoring strain, B6, should be ideal for allowing gene-targeting to go either way. In addition, this new task, which enables automated training of odor associations, could be used for studying the phenomenon of transitivity in mice, as described in rats.

Learning about the context in genetically-defined mice

Defective utilisation of background stimuli may result in a large range of cognitive impairments. We describe here three experimental paradigms taxing the processing of contextual information, (i) radial maze learning under distinct cueing conditions and successive context shifts; (ii) reactivity to spatial and object change; (iii) contextual versus cue fear conditioning with pre-test exposure to the experimental context. These paradigms have then been used to characterise the behaviour of null mutant and transgenic mice. In a first series of experiments, we assessed the effect of the null mutation of the gene encoding for Tissue Plasminogen Activator (tPA). Initial investigations pointed to a reduction of the late phase of long-term potentiation in tPA-knock out relative to wild type mice without any consistent performance impairment in several hippocampal-dependent tasks. When tested following our protocols, we found tPA knock out impaired in habituation of object exploration, reactivity to spatial change and contextual fear conditioning. The second example concerns mice overexpressing the mutant human Cu,Zn superoxide dismutase (SOD1) gene, that provide a murine model of amyotrophic lateral sclerosis. We found these mice exhibiting a paradoxical selective enhancement of reactivity to spatial change in comparison with mice overexpressing either the endogeneous murine Cu,Zn SOD1 or the wild type human Cu,Zn SOD1 genes. Our conclusion emphasises the view that experimental protocols involving contextual manipulations may be suitable for differentiating behavioural phenotypes.

Fear conditioning in C57/BL/6 and DBA/2 mice: variability in nucleus accumbens function according to the strain predisposition to show contextual- or cue-based responding

The contribution of the nucleus accumbens shell, the dorsal hippocampus, and the basolateral amygdala to contextual and explicit cue fear conditioning was assessed in C57BL/6 (C57) and DBA/2 (DBA) mice showing differences in processing contextual information associated with consistent but non-pathological variations in hippocampal functionality. Mice from both strains with bilateral ibotenic acid or sham lesions located in each area were introduced in a conditioning chamber and exposed twice to the pairing of a tone (2 x 8 s, 2000 Hz, 80 dB) with a shock (2 s, 0.7 mA). On the following day, mice were first exposed to the training context then to the tone in a different context. Freezing behaviour was scored in all situations. C57 showed more freezing to the context than to the tone whereas DBA showed more freezing to the tone than to the context. In C57, both nucleus accumbens and hippocampal lesions impaired acquisition of contextual fear conditioning but paradoxically improved acquisition of cue fear conditioning, whereas amygdala lesions disrupted performance in every task. In DBA, nucleus accumbens lesions, like amygdala lesions, impaired acquisition of both contextual and cue fear conditioning, whereas hippocampal lesions did not produce any effect. The parallelism between the effect of nucleus accumbens and hippocampus lesions in C57, and between the effect of nucleus accumbens and amygdala lesions in DBA points to a variability in nucleus accumbens function according to the strain specialization to develop context- or cue-based responding.

Contextual-dependent effects of nucleus accumbens lesions on spatial learning in mice

The effect of nucleus accumbens lesions on radial maze performance of C57BL/6 and DBA/2 mice was assessed under distinct extra-maze cuing conditions. Among sham-lesioned mice, C57BL/6 performed better under rich than poor cuing conditions whereas DBA performed in the same fashion under both conditions. In C57BL/6, a disruptive effect of lesions was found only in mice tested under rich cuing. Conversely, in DBA/2, the lesions improved performance under poor cuing and disrupted performance under rich cuing. In that strain, a possible lesion-induced enhancement of attention to background stimuli improving performance under poor cuing but producing interference under rich cuing is suggested. In general, the lesions effect seemed to depend on the strain predisposition to implement configural or cue-based responding.