Continual pre-training mitigates forgetting in language and vision.

Pre-trained models are commonly used in Continual Learning to initialize the model before training on the stream of non-stationary data. However, pre-training is rarely applied during Continual Learning. We investigate the characteristics of the Continual Pre-Training scenario, where a model is continually pre-trained on a stream of incoming data and only later fine-tuned to different downstream tasks. We introduce an evaluation protocol for Continual Pre-Training which monitors forgetting against a Forgetting Control dataset not present in the continual stream. We disentangle the impact on forgetting of 3 main factors: the input modality (NLP, Vision), the architecture type (Transformer, ResNet) and the pre-training protocol (supervised, self-supervised). Moreover, we propose a Sample-Efficient Pre-training method (SEP) that speeds up the pre-training phase. We show that the pre-training protocol is the most important factor accounting for forgetting. Surprisingly, we discovered that self-supervised continual pre-training in both NLP and Vision is sufficient to mitigate forgetting without the use of any Continual Learning strategy. Other factors, like model depth, input modality and architecture type are not as crucial.

Diagnostic Accuracy of DNA-Methylation in Detection of Cervical Dysplasia: Findings from a Population-Based Screening Program.

BACKGROUND: Epigenetic biomarkers in cancer have emerged as promising tools for early detection, prognosis, and treatment response prediction. In cervical cells, hypermethylation of the host and viral HPV-genome increases with the severity of lesions, providing a useful biomarker in the triage of hr-HPV-positive women and during treatment. The present study focuses on evaluating the clinical performance of the FAM19A4/miR124-2 methylation test in a population-based cervical screening program. METHODS: Previously collected cervical samples, after bisulfite-converted DNA, were analyzed by PreCursor-M+ kit (distributed by Fujirebio Europe), for DNA methylation. The sensitivity, specificity, and negative/positive predictive values of DNA methylation were compared to histology, colposcopy, the HPV-DNA test, and cytology results. RESULTS: Among the 61-sample set, the specificity of methylation vs. positive histology (≥CIN2) and colposcopy (≥G2) were 87% and 90%, whereas the sensitivity was 50% and 33.3%, respectively. The combination of methylation analysis with standard methods increases diagnostic accuracy. CONCLUSIONS: Overall, we found a good specificity of DNA methylation in comparison to currently used techniques. Further larger studies could support the use of FAM19A4/miR124-2 as reliable biomarkers in the prevention of cervical cancer as triage in the screening protocol.

Lung (extracorporeal CO2 removal) and renal (continuous renal replacement therapy) support: the role of ultraprotective strategy in Covid 19 and non-Covid 19 ARDS. A case-control study.

BACKGROUND: Preliminary studies suggest that moderate ARDS and acute renal failure might benefit from extracorporeal CO2 removal (ECCO2R) coupled with CRRT. However, evidence is limited and potential for this coupled treatment may need to be explored. The aim of the present study was to evaluate whether a protective driving pressure was obtained applying low-flow ECCO2-R plus CRRT in patients affected by moderate ARDS with COVID-19 compared to an historical group without COVID-19. METHODS: A case-control study has been conducted comparing a group of consecutive moderate ARDS patients presenting AKI and affected by COVID-19, who needed low-flow ECCO2-R plus CRRT to achieve an ultra-protective ventilatory strategy, with historical group without COVID-19 that matched for clinical presentation and underwent the same ultra-protective treatment. VT was set at 6 mL/kg predicted body weight then ECCO2R was assessed to facilitate ultra-protective low VT ventilation to preserve safe Pplat and low driving pressure. RESULTS: ECCO2R+CRRT reduced the driving pressure from 17 (14-18) to 11.5 (10-15) cmH2O (p<0.0004) in the fourteen ARDS patients by decreasing VT from 6.7 ml/kg PBW (6.1-6.9) to 5.1 (4.2-5.6) after 1 hour (p <0.0001). In the ARDS patients with COVID-19, the driving pressure reduction was more effective from baseline 18 (14-24) cmH2O to 11 (10-15) cmH2O (p<0.004), compared to the control group from 15 (13-17) to 12(10-16) cmH2O (p< 0.03), after one hour. ECCO2R+CRRT did not affected 28 days mortality in the two groups, while we observed a shorter duration of mechanical ventilation (19 {7-29} vs 24 {22-38} days; p=0.24) and ICU length of stay (19 {7-29} vs 24 {22-78} days; p=0.25) in moderate ARDS patients with COVID-19 compared to control group. CONCLUSIONS: In moderate ARDS patients with or without COVID-19 disease, ECCO2R+CRRT may be and effective supportive treatment to reach protective values of driving pressure unless severe oxygenation defects arise requiring ECMO therapy initiation.

A Whole-Genome Sequencing-Based Approach for the Characterization of Klebsiella pneumoniae Co-Producing KPC and OXA-48-like Carbapenemases Circulating in Sardinia, Italy.

BACKGROUND: Whole-genome sequencing (WGS) provides important information for the characterization, surveillance, and monitoring of antimicrobial resistance (AMR) determinants, particularly in cases of multi- and extensively drug-resistant microorganisms. We reported the results of a WGS analysis carried out on carbapenemases-producing Klebsiella pneumoniae, which causes hospital-acquired infections (HAIs) and is characterized by a marked resistance profile. METHODS: Clinical, phenotypic, and genotypic data were collected for the AMR surveillance screening program of the University Hospital of Sassari (Italy) during 2020-2021. Genomic DNA was sequenced using the Illumina Nova Seq 6000 platform. Final assemblies were manually curated and carefully verified for the detection of antimicrobial resistance genes, porin mutations, and virulence factors. A phylogenetic analysis was performed using the maximum likelihood method. RESULTS: All 17 strains analyzed belonged to ST512, and most of them carried the blaKPC-31 variant blaOXA-48-like, an OmpK35 truncation, and an OmpK36 mutation. Phenotypic analysis showed a marked resistance profile to all antibiotic classes, including ß-lactams, carbapenems, aminoglycosides, fluoroquinolone, sulphonamides, and novel ß-lactam/ß-lactamase inhibitors (BL/BLI). CONCLUSION: WGS characterization revealed the presence of several antibiotic resistance determinants and porin mutations in highly resistant K. pneumoniae strains responsible for HAIs. The detection of blaKPC-31 in our hospital wards highlights the importance of genomic surveillance in hospital settings to monitor the emergence of new clones and the need to improve control and preventive strategies to efficiently contrast AMR.

Infection Prevention Control Strategies of New Delhi Metallo-ß-lactamase Producing Klebsiella pneumoniae.

The spread of multi-drug resistant organisms (MDROs) is increasing at an alarming rate worldwide. Among these, Carbapenemase-producing New Delhi Metallo-ß-lactamase (NDM) poses a significant clinical threat, and appropriate measures must be taken to prevent or limit its penetration into still-free territories. The present report describes two independent cases of patients from Ukraine colonized by NDM-producing Klebsiella pneumoniae and admitted to two separate wards of an acute university hospital in a territory not yet affected by Carbapenemase producers of this class. Moreover, this report illustrates the infection prevention control (IPC) strategies promptly implemented by the IPC operational team to verify the possible spread of the microorganism in the ward and avoid any possible further contamination. The identification of genes coding for Carbapenemases, performed using real-time PCR, revealed no other cases within the wards involved. These cases emphasize the importance of early case recognition of multidrug-resistant bacteria, the necessity of effective inter-hospital communication, the need for effective antimicrobial stewardship protocol, and the importance of adequate IPC policies. Additionally, we highlight the need to improve screening procedures in the case of patients from countries with a high prevalence of MDRO, as essential measures to prevent potential nosocomial outbreaks and/or endemization.

Preliminary Results of Feasibility and Acceptability of Self-Collection for Cervical Screening in Italian Women.

BACKGROUND: Given the diagnostic accuracy of HPV-DNA tests in terms of self-collected samples, in order to implement self-sampling in cervical screening programs, the standardization of the pre-analytical phase, including decisions concerning the choice of medium, the volume of elution, and storage conditions, are necessary, in addition to understanding the potential factors involved in acceptability by women. On this basis, we carried out a cross-sectional study to assess (i) the stability of dry vaginal self-collected samples stored at room temperature for up to 4 weeks after elution in 2 mL of eNat® (Copan) medium, and (ii) the acceptability of self-collection in enrolled women. METHODS: 185 women were enrolled in the LILT (Italian League Against Tumors) regional project. A self-sampling kit, including a dry FLOQSwab® (Copan), instructions for use, and a satisfaction questionnaire, were supplied for each woman and sent by mail to the laboratory. The HPV-DNA test was carried out using the Anyplex™ II HPV HR (Seegene) kit. To evaluate the specimen's stability, 185 dry vaginal swabs were eluted in eNat®, a lyses-based molecular medium and tested for HPV detection at two different time points (<6 days and 1 month after elution). The Cohen's Kappa coefficients and McNemar test were used to assess the agreement of HPV-DNA at different times. RESULTS: We found high agreement in terms of HPV-DNA results among the samples tested at two different time points (Cohen K = 0.98; p < 0.0001). Moreover, most of the women found it easy to use self-collection devices and the pictorial instructions clear to understand. Approximately half of the enrolled women declared preferring self-sampling to clinician-collected methods. CONCLUSION: Our results display the high reliability and accuracy of HPV-DNA tests using dry vaginal self-collection FLOQSwabs® devices eluted in 2 mL of molecular medium. The analysis of the questionnaire showed a high acceptability of self-collection among women, although a high percentage preferred standard collection devices. Overall, our preliminary results support the adoption of self-collection in screening programs, even though further analyses should be performed to optimize and standardize protocols for HPV tests on self-samples, and educational campaigns are needed to adequately inform and increase responsiveness in a target population.

Preexisting Immunity Drives the Response to Neoadjuvant Chemotherapy in Esophageal Adenocarcinoma.

Current treatment for patients with locally advanced esophageal adenocarcinoma (EAC) is neoadjuvant chemotherapy (nCT), alone or combined with radiotherapy, before surgery. However, fewer than 30% of treated patients show a pathologic complete response to nCT, which correlates with increased 5-year survival compared with nonresponders. Understanding the mechanisms of response to nCT is pivotal to better stratify patients and inform more efficacious therapies. Here, we investigated the immune mechanisms involved in nCT response by multidimensional profiling of pretreatment tumor biopsies and blood from 68 patients with EAC (34 prospectively and 34 retrospectively collected), comparing complete responders versus nonresponders to nCT. At the tumor level, complete response to nCT was associated with molecular signatures of immune response and proliferation, increased putative antitumor tissue-resident memory CD39+ CD103+ CD8+ T cells, and reduced immunosuppressive T regulatory cells (Treg) and M2-like macrophages. Systemically, complete responders showed higher frequencies of immunostimulatory CD14+ CD11c+ HLA-DRhigh cells, and reduced programmed cell death ligand 1-positive (PD-L1+) monocytic myeloid-derived suppressor cells, along with high plasma GM-CSF (proinflammatory) and low IL4, CXCL10, C3a, and C5a (suppressive). Plasma proinflammatory and suppressive cytokines correlated directly and inversely, respectively, with the frequency of tumor-infiltrating CD39+ CD103+ CD8+ T cells. These results suggest that preexisting immunity in baseline tumor drives the clinical activity of nCT in locally advanced EAC. Furthermore, it may be possible to stratify patients based on predictive immune signatures, enabling tailored neoadjuvant and/or adjuvant regimens. SIGNIFICANCE: Multidimensional profiling of pretreatment esophageal adenocarcinoma shows patient response to nCT is correlated with active preexisting immunity and indicates molecular pathways of resistance that may be targeted to improve clinical outcomes.

Endoscopic vacuum therapy versus self-expandable metal stent for treatment of anastomotic leaks < 30 mm following oncologic Ivor-Lewis esophagectomy: a matched case-control study.

BACKGROUND: Management of anastomotic leaks after Ivor-Lewis esophagectomy remains a challenge. Although intracavitary endoscopic vacuum therapy (EVT) has shown great efficacy for large dehiscences, the optimal management of smaller leaks has not been standardized. This study aims to compare EVT versus self-expandable metal stent (SEMS) in the treatment of leaks < 30 mm in size, due to the lack of current data on this topic. METHODS: Patients undergoing EVT (cases) or SEMS (controls) between May 2017 and July 2022 for anastomotic leaks < 3 cm following oncologic Ivor-Lewis esophagectomy were enrolled. Controls were matched in a 1:1 ratio based on age (± 3 years), BMI (± 3 kg/m2) and leak size (± 4 mm). RESULTS: Cases (n = 22) and controls (n = 22) showed no difference in baseline characteristics and leak size, as per matching at enrollment. No differences were detected between the two groups in terms of time from surgery to endoscopic treatment (p = 0.11) or total number of procedures per patient (p = 0.05). Remarkably, the two groups showed comparable results in terms of leaks resolution (90.9% vs. 72.7%, p = 0.11). The number of procedures per patient was not significant between the two cohorts (p = 0.05). The most frequent complication in the SEMS group was migration (15.3% of procedures). CONCLUSION: EVT and SEMS seem to have similar efficacy outcomes in the treatment of anastomotic defects < 30 mm after Ivor-Lewis esophagectomy. However, larger studies are needed to corroborate these findings.

Sarcopenia and Patient's Body Composition: New Morphometric Tools to Predict Clinical Outcome After Ivor Lewis Esophagectomy: a Multicenter Study.

BACKGROUND: The impact of preoperative body composition as independent predictor of prognosis for esophageal cancer patients after esophagectomy is still unclear. The aim of the study was to explore such a relationship. METHODS: This is a multicenter retrospective study from a prospectively maintained database. We enrolled consecutive patients who underwent Ivor-Lewis esophagectomy in four Italian high-volume centers from May 2014. Body composition parameters including total abdominal muscle area (TAMA), visceral fat area (VFA), and subcutaneous fat area (SFA) were determined based on CT images. Perioperative variables were systematically collected. RESULTS: After exclusions, 223 patients were enrolled and 24.2% had anastomotic leak (AL). Sixty-eight percent of patients were sarcopenic and were found to be more vulnerable in terms of postoperative 90-day mortality (p = 0.028). VFA/TAMA and VFA/SFA ratios demonstrated a linear correlation with the Clavien-Dindo classification (R = 0.311 and 0.239, respectively); patients with anastomotic leak (AL) had significantly higher VFA/TAMA (3.56 ± 1.86 vs. 2.75 ± 1.83, p = 0.003) and VFA/SFA (1.18 ± 0.68 vs. 0.87 ± 0.54, p = 0.002) ratios. No significant correlation was found between preoperative BMI and subsequent AL development (p = 0.159). Charlson comorbidity index correlated significantly with AL (p = 0.008): these patients had a significantly higher index (≥ 5). CONCLUSION: Analytical morphometric assessment represents a useful non-invasive tool for preoperative risk stratification. The concurrent association of sarcopenia and visceral obesity seems to be the best predictor of AL, far better than simple BMI evaluation, and potentially modifiable if targeted with prehabilitation programs.

Relaparoscopy in the management of post-operative complications after minimally invasive gastrectomy for gastric cancer.

Laparoscopy has already been validated for treatment of early gastric cancer. Despite that, no data have been published about the possibility of a minimally invasive approach to surgical complications after primary laparoscopic surgery. In this multicentre study, we describe our experience in the management of complications following laparoscopic gastrectomy for gastric cancer. A chart review has been performed over data from 781 patients who underwent elective gastrectomy for gastric cancer between January 1996 and July 2020 in two high referral department of gastric surgery. A fully descriptive analysis was performed, considering all the demographic characteristics of patients, the type of primary procedure and the type of complication which required reoperation. Moreover, a logistic regression was designed to investigate if either the patients or the primary surgery characteristics could affect conversion rate during relaparoscopy. Fifty-one patients underwent reintervention after elective laparoscopic gastric surgery. Among patients who received a laparoscopic reintervention, 11 patients (34.3%) required a conversion to open surgery. Recovery outcomes were significantly better in patients who completed the reoperation through laparoscopy. Relaparoscopy is safe and effective for management of complications following laparoscopic gastric surgery and represent a useful tool both for re-exploration and treatment, in expert and skilled hands.

Post-esophagectomy tracheobronchoesophageal fistula: management and results of a tertiary referral center.

A tracheobronchoesophageal fistula (TBEF) is a rare but life-threatening complication after esophagectomy. The existing literature on TBEF management is limited and many previous recommendations are contradictory. We aimed to describe our series of TBEF after esophagectomy and compare it with other reported series. Patients who developed a TBEF after esophagectomy were identified retrospectively. Baseline and intraoperative characteristics, postoperative and TBEF details, treatments for TBEF, and main outcomes are described. A univariate analysis was performed to compare some of the analyzed variables with the overall sample. Finally, our results are compared with the previously described series. Altogether, 16 patients with TBEF (3.11%) were analyzed from 514 patients who received esophagectomies between January 2014 and February 2020. As a first treatment attempt, 14 (87.5%) were treated with surgery, one was treated conservatively, and one was treated endoscopically. Surgery both at a first or second treatment attempt achieved a survival rate of 62.5% and oral intake at discharge of 43.75%. Six patients died during their hospital stay (37.5%). The presence of an anastomotic leak showed a strong association with TBEF development (100% vs. 19.7%; OR 1.163, 95% CI 1.080-1.253, p = 0.000). In our experience, surgical treatment as the first approach for TBEF associated with anastomotic leak after esophagectomy obtained good results. However, there is an urgent need to elaborate treatment guidelines based on international consensus.

Does immunotherapy change the treatment paradigm in metastatic gastric cancer?

Gastric cancer represents one of the leading causes of cancer-related death worldwide. Even if the last decade has witnessed an improvement in surgical and systemic treatments, with an increase of overall life expectancy, survival rates still remain unsatisfactory, especially for patients with metastatic disease. Systemic therapies represent the gold standard in the management of stage IV gastric cancer. In this scenario, the availability of effective second and third lines has represented for a long time the only hope to offer an overall survival improvement to these patients. Recently, the advent of immune checkpoint inhibitors has involved also gastric cancer with encouraging efficacy data in the metastatic setting, becoming integral part of the management of selected patients.

Low Prevalence of HPV Related Oropharyngeal Carcinogenesis in Northern Sardinia.

HPV infection is a clear etiopathogenetic factor in oropharyngeal carcinogenesis and is associated with a markedly better prognosis than in smoking- and alcohol-associated cases, as specified by AJCC classification. The aim of the present work is to evaluate the prevalence of HPV-induced OPSCC in an insular area in the Mediterranean and to assess the reliability of p16 IHC (immunohistochemistry) alone, as accepted by AJCC, in the diagnosis of HPV-driven carcinogenesis in such a setting. All patients with OPSCC consecutively managed by the referral center in North Sardinia of head and neck tumor board of AOU Sassari, were recruited. Diagnosis of HPV-related OPCSS was carried out combining p16 IHC and DNA testing on FFPE samples and compared with the results of p16 IHC alone. Roughly 14% (9/62) of cases were positive for HPV-DNA and p16 IHC. Three more cases showed overexpression of p16, which has a 100% sensitivity, but only 75% specificity as standalone method for diagnosing HPV-driven carcinogenesis. The Cohen's kappa coefficient of p16 IHC alone is 0.83 (excellent). However, if HPV-driven carcinogenesis diagnosed by p16 IHC alone was considered the criterion for treatment deintensification, 25% of p16 positive cases would have been wrongly submitted to deintensified treatment for tumors as aggressive as a p16 negative OPSCC. The currently accepted standard by AJCC (p16 IHC alone) harbors a high rate of false positive results, which appears risky for recommending treatment deintensification, and for this aim, in areas with a low prevalence of HPV-related OPSCC, it should be confirmed with HPV nucleic acid detection.

Knowledge, Attitudes, and Behaviors towards Proper Nutrition and Lifestyles in Italian Diabetic Patients during the COVID-19 Pandemic.

Prevention of diabetes mellitus is mainly based on a healthy lifestyle. The lockdown measures imposed during the COVID-19 pandemic resulted in major changes in daily life and social behavior, which may have an influence on diabetes self-management and glycemic control. The present work aims to assess the relationship between diabetic patients' knowledge, attitudes, and behaviors towards proper nutrition and lifestyles in order to plan strategies for educational intervention from a health literacy perspective. Attitudes, behaviors, and knowledge of diabetic patients attending the Diabetes and Metabolic Diseases Department of the Local Health Authority of Sassari (ASL1-SS) were assessed with a cognitive survey conducted from April to July 2022. Three hundred twenty-one questionnaires were administered during the survey period. Fifty-two percent of diabetic patients were female and 48% male, with a mean age of 61.1 ± 18.5 years and 62.0 ± 15.1 years, respectively. The overall level of knowledge about the role of food and proper nutrition with respect to the risk of diabetes and its complications appeared to be generally unsatisfactory and inadequate. Nonetheless, females showed a significantly higher level of knowledge than males (p < 0.0001). Moreover, knowledge was seen to decrease according to the age of the patients (p = 0.035). As for the possible impact played by the COVID-19 pandemic on lifestyles, it should be noted that about 70% of the respondents stated that they had maintained a reasonable dietary standard or even improved it throughout. Thus, the study underlines the need to improve the knowledge of diabetic subjects about nutrition and, in particular, their self-management, positively influencing behaviors and attitudes.

Impact on breast cancer susceptibility and clinicopathological traits of common genetic polymorphisms in TP53, MDM2 and ATM genes in Sardinian women.

Common variants of genes involved in DNA damage correction [tumor protein p53 (TP53), murine double 2 homolog oncoprotein (MDM2) and ataxia-telengiectasia mutated (ATM)] may serve a role in cancer predisposition. The purpose of the present study was to investigate the association of five variants in these genes with breast cancer risk and clinicopathological traits in a cohort of 261 women from northern Sardinia. Polymorphic variants in TP53 (rs17878362, rs1042522 and rs1625895), MDM2 (rs2279744) and ATM (rs1799757) were determined by PCR and TaqMan single nucleotide polymorphism assay in patients with breast cancer (n=136) and healthy controls (n=125). Association with clinicopathological (e.g., age at diagnosis, lymph node involvement, clinical stage) and lifestyle factors (e.g., smoking status, alcohol intake, contraceptive use) was also evaluated. TP53 rs17878362 and rs1625895 polymorphisms were associated with decreased risk of BC diagnosis in patients older than 50 years (codominant and recessive models) and post-menopause (recessive model). Furthermore, there was a significant association between lymph node status (positive vs. negative) and ATM rs1799757-delT in dominant and additive models and between MDM2 rs2279744-allele and use of oral contraceptives. This analysis suggested that TP53 rs17878362 and rs1625895 may affect age of onset of breast cancer and ATM rs1799757 and MDM2 rs2279744 may be associated with lymph node status and prolonged use of oral contraceptives, respectively.

Applicative Limitations of Indocyanine Green Fluorescence Assistance to Laparoscopic Lymph Node Dissection in Total Gastrectomy for Cancer.

BACKGROUND: Indocyanine green (ICG) fluorescence has been recently introduced as a novel imaging technique improving the accuracy of lymph node (LN) dissection in gastric cancer (GC) surgery, although procedure standardization and achievements have not been clearly defined. This study analyzed the feasibility and effectiveness of ICG-guidance for laparoscopic D2-lymphadenectomy during total gastrectomy for cancer. METHODS: This study retrospectively analyzed a single-center series of patients who underwent laparoscopic total gastrectomy for cancer between April 2015 and August 2021. All patients underwent surgery with standard D2 LN dissection. Intraoperative ICG-fluorescence was institutionally implemented in April 2018 and was performed routinely afterward. Primary outcomes were LN harvest and ratio. Secondary endpoints included operative time and subgroup analysis to assess variables potentially affecting LN retrieval. RESULTS: The study population included 102 patients, and ICG-fluorescence was applied in 38 (37.3%). ICG and no-ICG groups presented similar median age, gender proportions, ASA score and comorbidities (age-adjusted Charlson Comorbidity Index), body mass index, and advanced pathological stage. The median of LNs retrieved was significantly higher after the intraoperative ICG-guidance (44 vs. 32; p = 0.004), although this association was not significant after neoadjuvant therapy or among patients with positive LNs. Lymph node ratio and operative time were not significantly impacted by ICG fluorescence. Multivariate analysis identified the ICG-assistance as the only independent determinant for LN harvest (p = 0.029). CONCLUSIONS: ICG-guidance contributes to a significantly wider LN retrieval after laparoscopic D2-lymphadenectomy during total gastrectomy for cancer. However, neoadjuvant therapy and positive LN stage appeared to limit the procedural effectiveness to ICG-assisted LN identification.

Is Class-Incremental Enough for Continual Learning?

The ability of a model to learn continually can be empirically assessed in different continual learning scenarios. Each scenario defines the constraints and the opportunities of the learning environment. Here, we challenge the current trend in the continual learning literature to experiment mainly on class-incremental scenarios, where classes present in one experience are never revisited. We posit that an excessive focus on this setting may be limiting for future research on continual learning, since class-incremental scenarios artificially exacerbate catastrophic forgetting, at the expense of other important objectives like forward transfer and computational efficiency. In many real-world environments, in fact, repetition of previously encountered concepts occurs naturally and contributes to softening the disruption of previous knowledge. We advocate for a more in-depth study of alternative continual learning scenarios, in which repetition is integrated by design in the stream of incoming information. Starting from already existing proposals, we describe the advantages such class-incremental with repetition scenarios could offer for a more comprehensive assessment of continual learning models.

High-Risk Clone of Klebsiella pneumoniae Co-Harbouring Class A and D Carbapenemases in Italy.

Background: Carbapenem-resistant Klebsiella pneumoniae (CR-Kp) is endemic globally, causing severe infections in hospitalized patients. Surveillance programs help monitor and promptly identify the emergence of new clones. We reported the rapid spread of a novel clone of K. pneumoniae co-harbouring class A and D carbapenemases in colonized patients, and the potential risk factors involved in the development of infections. Methods: Rectal swabs were used for microbiological analyses and detection of the most common carbapenemase encoding genes by real-time PCR (i.e., blaKPC, blaOXA-48, blaNDM, blaVIM, and blaIMP). All strains co-harbouring KPC and OXA-48 genes were evaluated. For each patient, the following variables were collected: age, sex, length and ward of stay, device use, and outcome. Clonality of CR-Kp was assessed by preliminary pulsed field gel electrophoresis (PFGE), followed by multi-locus sequence typing (MLST) analyses. Results: A total of 127 isolates of K. pneumoniae co-harbouring KPC and OXA-48 were collected between September 2019 and December 2020. The median age (IQR) of patients was 70 (61-77). More than 40% of patients were admitted to intensive care unit (ICU). Around 25% of patients developed an invasive infection, the majority of which were respiratory tract infections (17/31; 54.8%). ICU stay and invasive infection increased the risk of mortality (OR: 5.39, 95% CI: 2.42-12.00; OR 6.12, 95% CI: 2.55-14.69, respectively; p-value ≤ 0.001). The antibiotic susceptibility test showed a resistance profile for almost all antibiotics considered. Monoclonal origin was confirmed by PFGE and MLST showing a similar restriction pattern and belonging to ST-512. Conclusions: We report the spread and the marked antibiotic resistance profiles of K. pneumoniae strains co-producing KPC and OXA-48. Further study could clarify the roles of clinical and microbiological variables in the development of invasive infection and increasing risk of mortality, in colonized patients.

Catastrophic Forgetting in Deep Graph Networks: A Graph Classification Benchmark.

In this work, we study the phenomenon of catastrophic forgetting in the graph representation learning scenario. The primary objective of the analysis is to understand whether classical continual learning techniques for flat and sequential data have a tangible impact on performances when applied to graph data. To do so, we experiment with a structure-agnostic model and a deep graph network in a robust and controlled environment on three different datasets. The benchmark is complemented by an investigation on the effect of structure-preserving regularization techniques on catastrophic forgetting. We find that replay is the most effective strategy in so far, which also benefits the most from the use of regularization. Our findings suggest interesting future research at the intersection of the continual and graph representation learning fields. Finally, we provide researchers with a flexible software framework to reproduce our results and carry out further experiments.