Prevalence of SARS-CoV-2 IgG antibodies in an area of northeastern Italy with a high incidence of COVID-19 cases: a population-based study

ObjectivesA seroprevalence study of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) was conducted in a high-incidence area located in northeastern Italy.MethodsAll citizens above 10 years of age resident in five municipalities of the Autonomous Province of Trento, with the highest incidence of coronavirus disease 2019 (COVID-19) cases, were invited to participate in the study. Among 6098 participants, 6075 sera and a standardized questionnaire administered face-to-face were collected between 5 May and 15 May 2020 and examined. Symptomatic individuals and their family contacts were tested by RT-PCR. Anti-SARS-CoV-2 antibodies were detected using an Abbott SARS-CoV-2 IgG assay, which was performed on the Abbott Architect i2000SR automated analyser. Seroprevalence was calculated as the proportion of positive results among the total number tested. A multivariable logistic regression model was performed to assess the relationship between seropositive versus seronegative individuals for a set of explanatory variables.ResultsA total of 1402 participants were positive for IgG antibodies against SARS-CoV-2, with a prevalence of 23.1% (1402/6075). The highest prevalence was found in the age class 40–49 years. Overall, 34.4% (2096/6098) of the participants reported at least one symptom. The ratio between reported cases identified by molecular test and those with seropositive results was 1:3, with a maximum ratio of about 1:7 in the age group <20 years and a minimum around 1:1 in those >70 years old. The infection fatality rate was 2.5% (35/1402). Among the symptoms, anosmia and ageusia were strongly associated with seropositivity.ConclusionsThe estimated seroprevalence of 23% was three-fold higher than the number of cases reported in the COVID-19 Integrated Surveillance data in the study area. This may be explained in part by a relatively high number of individuals presenting mild or no illness, especially those of younger age, and people who did not seek medical care or testing, but who may contribute to virus transmission in the community.     

Biomechanical and clinical study of single posterior oblique cage POLIF in the treatment of degenerative diseases of the lumbar spine

Introduction

Aim of the study was to evaluate the biomechanical stability and the clinical efficacy of a lumbar interbody fusion obtained by single oblique cage implanted by a posterior approach.

Method

Through the realization of three finite element models (FEMs), the biomechanics of POLIF was compared to PLIF and TLIF. Ninety-four patients underwent interbody fusion by POLIF with instrumented posterolateral fusion. Clinical and radiographic outcomes were evaluated at regular intervals for at least 6 months.

Results

The FEMs showed no statistically significant differences in stability in compression and flexion–extension. Mean preoperative VAS score was 7.1, decreased to 2.1 at follow-up. Mean preoperative SF-12 value was 34.5 %, increased to 75.4 % at follow-up. All patients showed a good fusion rate and no hardware failure.

Discussion

POLIF associated to instrumented posterolateral fusion is a viable and safe surgical technique, which ensures a biomechanical stability similar to other surgical techniques.

     

Impaired Cotranslational Processing as a Mechanism for Type I Antithrombin Deficiency

Most secretory proteins, including antithrombin (AT), aresynthesized with a signal peptide, which is cleaved before the mature protein is exported from the cell. The signal peptide is important inthe process whereby nascent protein is recognized as requiring subsequent modification within the endoplasmic reticulum (ER). We haveidentified a novel mutation, 2436TC L(-10)P, which affects the central hydrophobic domain of the AT signal peptide, in a probandpresenting with venous thrombotic disease and type I AT deficiency. Weinvestigated the basis of the phenotype by examining expression inmammalian cells of a range of variant AT cDNAs with mutations affectingthe -10 residue. Glycosylated AT was secreted from COS-7 cellstransfected with wild-type AT, -10L deletion, -10V or -10M variants,but not variants with P, T, R, or G at -10. Cell-free expression ofwild-type and variant AT cDNAs was then performed in the presence ofcanine pancreatic microsomes, as a substitute for ER. Variant ATproteins with P, T, R, or G at residue -10 did not undergoposttranslational glycosylation, and their susceptibility to trypsindigestion suggested they had not been translocated into microsomes. Ourresults suggest that the ability of AT signal peptide to direct theprotein to ER for cotranslational processing events appears to becritically dependent on maintaining the hydrophobic nature of theregion including residue -10. The investigations have defined impairedcotranslational processing as a hitherto unrecognized cause ofhereditary AT deficiency.     

Spontaneous bacterial peritonitis due to carbapenemase-producing Enterobacteriaceae: Etiology and antibiotic treatment

Carbapenem antibiotics were first introduced in the 1980s and have long been considered the most active agents for the treatment of multidrug-resistant gram-negative bacteria. Over the last decade, carbapenem-resistant Enterobacteriaceae (CRE) have emerged as organisms causing spontaneous bacterial peritonitis. Infections caused by CRE have shown a higher mortality rate than those caused by bacteria sensitive to carbapenem antibiotics. Current antibiotic guidelines for the treatment of spontaneous bacterial peritonitis are insufficient, and rapid de-escalation of empiric antibiotic treatment is not widely recognized. This review summarizes the molecular characteristics, epidemiology and possible treatment of spontaneous bacterial peritonitis caused by CRE.     

Acute alcoholic hepatitis,end stage alcoholic liver disease and liver transplantation: An Italian position statement

Alcoholic liver disease encompasses a broad spectrum of diseases ranging from steatosis steatohepatitis, fibrosis, and cirrhosis to hepatocellular carcinoma. Forty-four per cent of all deaths from cirrhosis are attributed to alcohol. Alcoholic liver disease is the second most common diagnosis among patients undergoing liver transplantation (LT). The vast majority of transplant programmes (85%) require 6 mo of abstinence prior to transplantation; commonly referred to as the “6-mo rule”. Both in the case of progressive end-stage liver disease (ESLD) and in the case of severe acute alcoholic hepatitis (AAH), not responding to medical therapy, there is a lack of evidence to support a 6-mo sobriety period. It is necessary to identify other risk factors that could be associated with the resumption of alcohol drinking. The “Group of Italian Regions” suggests that: in a case of ESLD with model for end-stage liver disease < 19 a 6-mo abstinence period is required; in a case of ESLD, a 3-mo sober period before LT may be more ideal than a 6-mo period, in selected patients; and in a case of severe AAH, not responding to medical therapies (up to 70% of patients die within 6 mo), LT is mandatory, even without achieving abstinence. The multidisciplinary transplant team must include an addiction specialist/hepato-alcohologist. Patients have to participate in self-help groups.     

Engineering rotor ring stoichiometries in the ATP synthase

ATP synthase membrane rotors consist of a ring of c-subunits whose stoichiometry is constant for a given species but variable across different ones. We investigated the importance of c/c-subunit contacts by site-directed mutagenesis of a conserved stretch of glycines (GxGxGxGxG) in a bacterial c(11) ring. Structural and biochemical studies show a direct, specific influence on the c-subunit stoichiometry, revealing c(<11), c(12), c(13), c(14), and c(>14) rings. Molecular dynamics simulations rationalize this effect in terms of the energetics and geometry of the c-subunit interfaces. Quantitative data from a spectroscopic interaction study demonstrate that the complex assembly is independent of the c-ring size. Real-time ATP synthesis experiments in proteoliposomes show the mutant enzyme, harboring the larger c(12) instead of c(11), is functional at lower ion motive force. The high degree of compliance in the architecture of the ATP synthase rotor offers a rationale for the natural diversity of c-ring stoichiometries, which likely reflect adaptations to specific bioenergetic demands. These results provide the basis for bioengineering ATP synthases with customized ion-to-ATP ratios, by sequence modifications.