Neurological involvement in hospitalized children with SARS-CoV-2 infection: a multinational study

BACKGROUND AND OBJECTIVES

Neurological involvement associated with SARS-CoV-2 infection is increasingly recognized. However, the specific characteristics and prevalence in pediatric patients remain unclear. The objective of this study was to describe the neurological involvement in a multinational cohort of hospitalized pediatric patients with SARS-CoV-2.

METHODS

This was a multicenter observational study of children <18 years of age with confirmed SARS-CoV-2 infection or multisystemic inflammatory syndrome (MIS-C) and laboratory evidence of SARS-CoV-2 infection in children, admitted to 15 tertiary hospitals/healthcare centers in Canada, Costa Rica, and Iran February 2020-May 2021. Descriptive statistical analyses were performed and logistic regression was used to identify factors associated with neurological involvement.

RESULTS

One-hundred forty-seven (21%) of 697 hospitalized children with SARS-CoV-2 infection had neurological signs/symptoms. Headache (n = 103), encephalopathy (n = 28), and seizures (n = 30) were the most reported. Neurological signs/symptoms were significantly associated with ICU admission (OR: 1.71, 95% CI: 1.15-2.55; p = 0.008), satisfaction of MIS-C criteria (OR: 3.71, 95% CI: 2.46-5.59; p < 0.001), fever during hospitalization (OR: 2.15, 95% CI: 1.46-3.15; p < 0.001), and gastrointestinal involvement (OR: 2.31, 95% CI: 1.58-3.40; p < 0.001). Non-headache neurological manifestations were significantly associated with ICU admission (OR: 1.92, 95% CI: 1.08-3.42; p = 0.026), underlying neurological disorders (OR: 2.98, 95% CI: 1.49-5.97, p = 0.002), and a history of fever prior to hospital admission (OR: 2.76, 95% CI: 1.58-4.82; p < 0.001).

DISCUSSION

In this study, approximately 21% of hospitalized children with SARS-CoV-2 infection had neurological signs/symptoms. Future studies should focus on pathogenesis and long-term outcomes in these children.

Thrombosis and hemorrhage experienced by hospitalized children with SARS-CoV-2 infection or MIS-C: Results of the PICNIC registry

INTRODUCTION

Coagulopathy and thrombosis associated with SARS-CoV-2 infection are well defined in hospitalized adults and leads to adverse outcomes. Pediatric studies are limited.

METHODS

An international multicentered (n = 15) retrospective registry collected information on the clinical manifestations of SARS-CoV-2 and multisystem inflammatory syndrome (MIS-C) in hospitalized children from February 1, 2020 through May 31, 2021. This sub-study focused on coagulopathy. Study variables included patient demographics, comorbidities, clinical presentation, hospital course, laboratory parameters, management, and outcomes.

RESULTS

Nine hundred eighty-five children were enrolled, of which 915 (93%) had clinical information available; 385 (42%) had symptomatic SARS-CoV-2 infection, 288 had MIS-C (31.4%), and 242 (26.4%) had SARS-CoV-2 identified incidentally. Ten children (1%) experienced thrombosis, 16 (1.7%) experienced hemorrhage, and two (0.2%) experienced both thrombosis and hemorrhage. Significantly prevalent prothrombotic comorbidities included congenital heart disease (p-value .007), respiratory support (p-value .006), central venous catheter (CVC) (p = .04) in children with primary SARS-CoV-2 and in those with MIS-C included respiratory support (p-value .03), obesity (p-value .002), and cytokine storm (p = .012). Comorbidities prevalent in children with hemorrhage included age >10 years (p = .04), CVC (p = .03) in children with primary SARS-CoV-2 infection and in those with MIS-C encompassed thrombocytopenia (p = .001) and cytokine storm (p = .02). Eleven patients died (1.2%), with no deaths attributed to thrombosis or hemorrhage.

CONCLUSION

Thrombosis and hemorrhage are uncommon events in children with SARS-CoV-2; largely experienced by those with pre-existing comorbidities. Understanding the complete spectrum of coagulopathy in children with SARS-CoV-2 infection requires ongoing research.

SARS-CoV-2 infection in technology-dependent children: a multicenter case series

Purpose

The objective of this study was to describe the clinical course and outcomes in children with technology dependence (TD) hospitalized with SARS-CoV-2 infection.

Methods

Seventeen pediatric hospitals (15 Canadian and one each in Iran and Costa Rica) included children up to 17 years of age admitted February 1, 2020, through May 31, 2021, with detection of SARS-CoV-2. For those with TD, data were collected on demographics, clinical course and outcome.

Results

Of 691 children entered in the database, 42 (6%) had TD of which 22 had feeding tube dependence only, 9 were on supplemental oxygen only, 3 had feeding tube dependence and were on supplemental oxygen, 2 had a tracheostomy but were not ventilated, 4 were on non-invasive ventilation, and 2 were on mechanical ventilation prior to admission. Three of 42 had incidental SARS-CoV-2 infection. Two with end-stage underlying conditions were transitioned to comfort care and died. Sixteen (43%) of the remaining 37 cases required increased respiratory support from baseline due to COVID-19 while 21 (57%) did not. All survivors were discharged home.

Conclusion

Children with TD appear to have an increased risk of COVID-19 hospitalization. However, in the absence of end-stage chronic conditions, all survived to discharge.

Risk factors for severe PCR-positive SARS-CoV-2 infection in hospitalised children

OBJECTIVE

To identify risk factors for severe disease in children hospitalised for SARS-CoV-2 infection.

DESIGN

Multicentre retrospective cohort study.

SETTING

18 hospitals in Canada, Iran and Costa Rica from 1 February 2020 to 31 May 2021.

PATIENTS

Children<18 years of age hospitalised for symptomatic PCR-positive SARS-CoV-2 infection, including PCR-positive multisystem inflammatory syndrome in children (MIS-C).

MAIN OUTCOME MEASURE

Severity on the WHO COVID-19 Clinical Progression Scale was used for ordinal logistic regression analyses.

RESULTS

We identified 403 hospitalisations. Median age was 3.78 years (IQR 0.53-10.77). At least one comorbidity was present in 46.4% (187/403) and multiple comorbidities in 18.6% (75/403). Eighty-one children (20.1%) met WHO criteria for PCR-positive MIS-C. Progression to WHO clinical scale score ≥6 occurred in 25.3% (102/403). In multivariable ordinal logistic regression analyses adjusted for age, chest imaging findings, laboratory-confirmed bacterial and/or viral coinfection, and MIS-C diagnosis, presence of a single (adjusted OR (aOR) 1.90, 95% CI 1.13 to 3.20) or multiple chronic comorbidities (aOR 2.12, 95% CI 1.19 to 3.79), obesity (aOR 3.42, 95% CI 1.76 to 6.66) and chromosomal disorders (aOR 4.47, 95% CI 1.25 to 16.01) were independent risk factors for severity. Age was not an independent risk factor, but different age-specific comorbidities were associated with more severe disease in age-stratified adjusted analyses: cardiac (aOR 2.90, 95% CI 1.11 to 7.56) and non-asthma pulmonary disorders (aOR 3.07, 95% CI 1.26 to 7.49) in children<12 years old and obesity (aOR 3.69, 1.45-9.40) in adolescents≥12 years old. Among infants<1 year old, neurological (aOR 10.72, 95% CI 1.01 to 113.35) and cardiac disorders (aOR 10.13, 95% CI 1.69 to 60.54) were independent predictors of severe disease.

CONCLUSION

We identified risk factors for disease severity among children hospitalised for PCR-positive SARS-CoV-2 infection. Comorbidities predisposing children to more severe disease may vary by age. These findings can potentially guide vaccination programmes and treatment approaches in children.

Predictors of severe illness in children with multisystem inflammatory syndrome after SARS-CoV-2 infection: a multicentre cohort study

BACKGROUND

SARS-CoV-2 infection can lead to multisystem inflammatory syndrome in children (MIS-C). We sought to investigate risk factors for admission to the intensive care unit (ICU) and explored changes in disease severity over time.

METHODS

We obtained data from chart reviews of children younger than 18 years with confirmed or probable MIS-C who were admitted to 15 hospitals in Canada, Iran and Costa Rica between Mar. 1, 2020, and Mar. 7, 2021. Using multivariable analyses, we evaluated whether admission date and other characteristics were associated with ICU admission or cardiac involvement.

RESULTS

Of 232 children with MIS-C (median age 5.8 yr), 130 (56.0%) were male and 50 (21.6%) had comorbidities. Seventy-three (31.5%) patients were admitted to the ICU but none died. We observed an increased risk of ICU admission among children aged 13-17 years (adjusted risk difference 27.7%, 95% confidence interval [CI] 8.3% to 47.2%), those aged 6-12 years (adjusted risk difference 25.2%, 95% CI 13.6% to 36.9%) or those with initial ferritin levels greater than 500 μg/L (adjusted risk difference 18.4%, 95% CI 5.6% to 31.3%). Children admitted to hospital after Oct. 31, 2020, had numerically higher rates of ICU admission (adjusted risk difference 12.3%, 95% CI -0.3% to 25.0%) and significantly higher rates of cardiac involvement (adjusted risk difference 30.9%, 95% CI 17.3% to 44.4%). At Canadian sites, the risk of ICU admission was significantly higher for children admitted to hospital between December 2020 and March 2021 than those admitted between March and May 2020 (adjusted risk difference 25.3%, 95% CI 6.5% to 44.0%).

INTERPRETATION

We observed that age and higher ferritin levels were associated with more severe MIS-C. We observed greater severity of MIS-C later in the study period. Whether emerging SARS-CoV-2 variants pose different risks of severe MIS-C needs to be determined.

Infants hospitalized for acute COVID-19: disease severity in a multicenter cohort study

Age is the most important determinant of COVID-19 severity. Infectious disease severity by age is typically J-shaped, with infants and the elderly carrying a high burden of disease. We report on the comparative disease severity between infants and older children in a multicenter retrospective cohort study of children 0 to 17 years old admitted for acute COVID-19 from February 2020 through May 2021 in 17 pediatric hospitals. We compare clinical and laboratory characteristics and estimate the association between age group and disease severity using ordinal logistic regression. We found that infants comprised one-third of cases, but were admitted for a shorter period (median 3 days IQR 2-5 versus 4 days IQR 2-7), had a lower likelihood to have an increased C-reactive protein, and had half the odds of older children of having severe or critical disease (OR 0.50 (95% confidence interval 0.32-0.78)).    Conclusion: When compared to older children, there appeared to be a lower threshold to admit infants but their length of stay was shorter and they had lower odds than older children of progressing to severe or critical disease. What is Known: • A small proportion of children infected with SARS-CoV-2 require hospitalization for acute COVID-19 with a subgroup needing specialized intensive care to treat more severe disease. • For most infectious diseases including viral respiratory tract infections, disease severity by age is J-shaped, with infants having more severe disease compared to older children. What is New: • One-third of admitted children for acute COVID-19 during the first 14 months of the pandemic were infants. • Infants had half the odds of older children of having severe or critical disease.

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.

64 Is it enough: An Assessment of Parental Satisfaction with an International Adoption Clinic at a Pediatric Tertiary Care Center

Background

The circumstance in which internationally adopted children are born and live prior to adoption put them at high risk for health issues. Nearly all adoptees have complex medical conditions, the most common being cleft lip/palate, orthopaedic problems, infectious diseases, congenital heart diseases, and/or nutritional deficiencies, as well as cognitive impairments, and/or developmental delays. Specifically, nearly all institutionalized children will have expressive language delays and most will have motor delays. Although improvement can be seen with time, most do not attain their full potential. Additionally, by nature of adoption, all children experience trauma. In some situations, this will be further compounded by neglect and/or abuse faced prior to adoption, or during institutionalization. Consequently, almost all adoptees develop attachment difficulties. Trained medical professionals are required to screen, monitor, and provide management suggestions for this complex and unique population.

Objectives

To our knowledge, parental experience of an international adoption clinic has not yet been published. This parent-based evaluation of the parental experience at a pediatric tertiary care center’s international adoption clinic, provides insights that may help guide provision of care for this high-risk population in our centre, throughout the country, and internationally.

Design/Methods

A qualitative, exploratory design was employed using telephone interviews of eighteen parents of adoptees assessed by a pediatric tertiary care center’s international adoption clinic since 2010. This approach was chosen to allow for more extensive exploration of parental experience, and to identify barriers and facilitators of care. Interviews were 30 to 90 minutes, semi-structured, and transcribed verbatim. Field notes were made during the interviews to note intonation and major concerns, and were used to supplement transcripts during data analysis. Questions covered experiences with pre-adoption counselling, arranging the first clinic visit, health and developmental assessments, life after clinic discharge, and general comments/suggestions. Thematic analysis was performed on the transcripts using Maguire’s step-by-step guide.

Results

Analysis resulted in four main themes and seven subthemes. The first theme was “difficulty of international adoption”. The second theme “utility and impact of services offered” was subdivided into “pre-adoption counselling”, “clinic visits and medical assessments”, and “post adoption seminars”. The third theme “the administrative procedures of the clinic” was subdivided into “timing and ease of organizing a first visit”, and “hours of operation”. The final theme “gaps in care” was divided into “ongoing difficulty with attachment”, and “allied healthcare services”. These results demonstrate that parents of internationally adopted children often feel overwhelmed by the medical needs of their children and feel unsupported. They recommend comprehensive and in-person pre-adoption counselling with standard referral processes to ensure timely access to care. Post-arrival medical and developmental assessments should be flexible and complete. Most importantly, clinics should incorporate support from allied healthcare professionals, including social work, psychology, occupational therapy, and physiotherapy. In particular, parents were interested in further management of attachment.

Conclusion

This first parent-based evaluation of the parental experience at a pediatric tertiary care center’s international adoption clinic provides insights that may help guide provision of care to this high-risk population in centres across Canada and internationally.

87 Is Canadian Federal Legislation Effective in Preventing Youth Access to Vaping Initiation Products? A secret shopper and online study

Background

Electronic cigarette use (“vaping”) is associated with negative health outcomes. Vaping among youth has recently risen to the highest levels recorded. Between 2017 and 2018, Canadians 16 to 19 years old who reported vaping over the past 30 days increased by 74%. This directly coincides with the Tobacco and Vaping Products Act (the “Act”) enactment, which lifted the ban on e-cigarette importation and sales without pre-approval while attempting to restrict youth access to e-cigarettes, and the entry of JUUL e-cigarette products into the Canadian market.

Objectives

The purpose of the study was to evaluate the Act’s effectiveness in protecting the health of youth by preventing their access to vaping products, using a secret shopper interventional design.

Design/Methods

Study subjects were vaping and convenience store employees and deliverers of vaping products ordered online. Confederate researchers (minors aged 15-16 and young adults aged 19-21) entered retail stores to buy JUUL Starter Kits. Three improper scenarios were used: (1) a minor(s); (2) a young adult with no or invalid identification; and (3) a young adult with valid identification clearly purchasing on behalf of an accompanying minor. The main outcome measured was vendor willingness to sell, recorded upon exit from stores. Five minors also ordered JUUL Starter Kits online from their homes. Frequencies were calculated for each variable and tests of association were completed using chi square analysis.

Results

In total, 42.5% of vendors (51/120) were willing to sell JUUL Starter Kits to the young adults and minors. Most vendors requested identification in all scenarios (97/120, 80.8%) but, of these, 28 vendors were willing to sell even though no or false identification was provided (28.9% of those who requested identification). Of those vendors who did not request identification (23/130, 19.2%), all were willing to sell. Where a young adult was clearly buying vaping products for a minor, vendors were willing to sell 63.2% of the time (24/38, p=0.016). In five online purchase attempts, 60% of deliverers did not meet the Act’s verification requirements.

Conclusion

Given that almost half of the vendors were willing to sell JUUL Starter Kits in improper circumstances, the Act does not adequately achieve its goal of protecting the health of youth. To prevent youth access to vaping products, the Act needs stricter enforcement and amendment to impose positive obligations on vendors to request identification, to prohibit sales to adults buying for minors, and to require manufacturers to disclose the product contained in delivered parcels.

Is Canadian federal legislation effective in preventing youth access to vaping initiation products? A study using secret shoppers and online access in three Alberta cities

•

120 ‘improper’ secret shopper visits, 3 cities, to buy nicotine vaping initiation products.

•

Vendors willing to sell in 42.5% of shop visits.

•

Minors’ online purchasing attempts aided by deliverers and non-descriptive packaging.

The Tobacco and Vaping Products Act (Canada, 1997) (the “TVPA”) aims to protect the health of young persons by restricting access to vaping products. We studied whether the TVPA achieves this goal by sending young ‘secret shoppers’ to 120 shops in Calgary, Edmonton, and Red Deer to attempt to buy nicotine-based vaping-initiation products, and by asking minors to purchase the same product online. We used three ‘improper’ shop scenarios: 1. a minor or minors; 2. a young adult with no or invalid identification (“ID”); and 3. a young adult with valid ID but clearly buying for an accompanying minor. Of total vendors, 42.5% (51/120) were willing to sell to the young people (p < .001). Most vendors requested ID in all scenarios (97/120, 80.8%). Of these, 28 vendors (28.9% of those requesting ID), were still willing to sell the product. All vendors who did not request ID (23/120, 19.2%) were willing to sell; vape shops were more likely than convenience stores not to request ID (25.4% v. 13.1%). In five online purchase attempts, 60% of deliverers did not meet the TVPA’s ID verification requirements. The TVPA does not require packages to reveal their contents; one parent inadvertently signed for the parcel. To prevent youth access, the TVPA should require: a minimum nicotine product purchase age of 21, positive obligations on vendors to request ID, prohibition of sales to adults buying for minors, and that manufacturers disclose the product on posted or delivered parcels. The TVPA should be strictly enforced.

Short- and long-term management of cases of venom-induced anaphylaxis is suboptimal

BACKGROUND

Venom-induced anaphylaxis (VIA) accounts for severe reactions. However, little is known about the short- and long-term management of VIA patients.

OBJECTIVE

To assess the short- and long-term management of VIA.

METHODS

Using a national anaphylaxis registry (C-CARE), we identified VIA cases presenting to emergency departments in Montreal and to emergency medical services (EMSs) in western Quebec over a 4-year period. Data were collected on clinical characteristics, triggers, and management. Consenting patients were contacted annually regarding long-term management. Univariate and multivariate logistic regressions were used to identify factors associated with epinephrine use, allergist assessment, and administration of immunotherapy.

RESULTS

Between June 2013 and May 2017, 115 VIA cases were identified. Epinephrine was administered to 63.5% (95% confidence interval [CI], 53.9%-72.1%) of all VIA cases by a health care professional. Treatment of reactions without epinephrine was more likely in reactions occurring at home and in nonsevere cases (no hypotension, hypoxia, or loss of consciousness). Among 48 patients who responded to a follow-up questionnaire, 95.8% (95% CI, 84.6%-99.3%) were prescribed epinephrine auto-injector, 68.8% (95% CI, 53.6%-80.9%) saw an allergist who confirmed the allergy in 63.6% of cases, and 81.0% of those with positive testing were administered immunotherapy. Among cases with follow-up, seeing an allergist was less likely in patients with known ischemic heart disease.

CONCLUSION

Almost 30% of patients with suspected VIA did not see an allergist, only two thirds of those seeing an allergist had allergy confirmation, and almost one fifth of those with confirmed allergy did not receive immunotherapy. Educational programs are needed to bridge this knowledge-to-action gap.

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.