Duration of Untreated Cardiac Arrest and Clinical Relevance of Animal Experiments : The Relationship Between the “No-Flow” Duration and the Severity of Post-Cardiac Arrest Syndrome in a Porcine Model

INTRODUCTION: The study investigated the effect of untreated cardiac arrest (CA), i.e. \u201cno-flow\u201d time, on post-resuscitation myocardial and neurological injury, and survival in a pig model to identify an optimal duration that adequately reflects the most frequent clinical scenario. METHODS:: An established model of myocardial infarction followed by CA and cardiopulmonary resuscitation was used. Twenty-two pigs were subjected to 3 no-flow durations: short (8\u201310?min); intermediate (12\u201313?min); and long (14\u201315?min). Left ventricular ejection fraction (LVEF) was assessed together with thermodilution cardiac output (CO) and high sensitivity cardiac troponin T (hs-cTnT). Neurological impairment was evaluated by neurological scores, serum neuron specific enolase (NSE), and histopathology. RESULTS:: More than 60% of animals survived when the duration of CA was 6413?min, compared to only 20% for a duration 6514?min. Neuronal degeneration and neurological scores showed a trend towards a worse recovery for longer no-flow durations. No animals achieved a good neurological recovery for a no-flow 6514?min, in comparison to a 56% for a duration 6413?min (p?=?0.043). Serum NSE levels significantly correlated with the no-flow duration (r?=?0.892). Longer durations of CA were characterized by lower LVEF and CO compared to shorter durations (p?<?0.05). The longer was the no-flow time, the higher was the number of defibrillations delivered (p?=?0.043). The defibrillations delivered significantly correlated with LVEF and plasma hs-cTnT. CONCLUSIONS:: Longer no-flow durations caused greater post-resuscitation myocardial and neurological dysfunction and reduced survival. An untreated CA of 12\u201313?min may be an optimal choice for a clinically relevant model

Environmental survival of Mycoplasma bovis on a white veal farm

Mycoplasma bovis is an emerging cause of bovine respiratory disease (BRD), particularly in intensive feedlots where disease is mainly spread by aerosol route over close distances. The present study aimed to investigate the occurrence of mycoplasmas in the environment of barns housing white veal calves presenting BRD. The majority of calves seroconverted to M bovis three weeks after arrival; there was little evidence of respiratory virus activity, but Mannheimia haemolytica and Pasteurella multocida were isolated from clinically affected calves. M bovis was detected in nasal swabs of sick animals and also on cages and mangers. The isolates were mostly of the same molecular type, suggesting the possibility of infection from the environment. Environmental resistance conferred by biofilm formation might play a significant role in the continuous circulation of M bovis within the white veal herd, indicating the need for all-in, all-out replacement systems and effective disinfection

Technical note : Development of multiplex PCR assays for the molecular characterization of Streptococcus uberis strains isolated from bovine mastitis

Streptococcus uberis is an important causative agent for clinical and subclinical mastitis in dairy cattle. The aim of this study was to develop 2 multiplex PCR assays (mPCR) for the simultaneous detection of virulence factors and housekeeping genes for use when investigating the genetic variability and distribution of Strep. uberis virulence factors. The tuf, cpn60, pauA, sodA, sua, oppF, and gapC genes were grouped in assay 1 (mPCR1) and the hasA, hasB, and hasC genes were included in assay 2 (mPCR2). The detection limits were 11.8 pg and 5.9 pg of DNA for mPCR1 and mPCR2, respectively. The 2 mPCR assays were validated with 56 Strep. uberis strains isolated from mastitis milk samples collected from different bovine herds in northern Italy. Results revealed that gapC and oppF were detected in 98.2% of the strains, whereas sua and hasC genes were detected in 94.6 and 89.2% of the strains, respectively. The most common pattern was gapC+, oppF+, cpn60+, sua+, sodA+, pauA+, tuf+, hasA+, hasB+, and hasC+, which appeared in 59% of the strains analyzed. The molecular assays developed in the present study represent a powerful tool for the evaluation of virulence pattern distribution in Strep. uberis strains associated with intramammary infections

Is Shigatoxin 1 protective for the development of Shigatoxin 2-related hemolytic uremic syndrome in children? Data from the ItalKid-HUS Network

Background: Shigatoxin (Stx)-producing Escherichia coli (STEC) are the most common causes of hemolytic uremic syndrome (STEC-HUS). The aim of our study is to compare the risk of developing STEC-HUS in relation to the type of Stx genes (Stx1, Stx2, or both). Methods: This is a prospective, observational, multicenter study involving 63 pediatric units in Northern Italy (ItalKid-HUS Network). STEC-infected children were identified within a screening program for bloody diarrhea during a 10-year period (2010\u20132019). Stx genes were detected by reverse dot blot or real-time PCR. After the identification of STEC infection, children were followed until diarrhea complete recovery for the possible development of STEC-HUS. Results: Of the 214 Stx-positive patients, 34 (15.9%) developed STEC-HUS. The risk of HUS in STEC-infected children with Stx1 (n: 62; 29.0%) and Stx2 (n: 97; 45.3%) was respectively 0% and 23.7%, while in patients carrying both Stx1 and Stx2 (n: 55; 25.7%), the risk was 12.7% (p: 0.001). Conclusions: Our data confirm that Stx1 is a very rare cause of STEC-HUS and demonstrate that the risk of STEC-HUS halves in the case of Stx1+2-producing Escherichia coli infection compared with infections where Stx2 is present alone. This observation is helpful in assessing the risk of individual STEC-infected patients for the development of HUS and suggests that Stx1, in the presence of Stx2, might exert a protective role possibly by receptor competition

Is Shigatoxin 1 protective for the development of Shigatoxin 2-related hemolytic uremic syndrome in children? Data from the ItalKid-HUS Network

Background: Shigatoxin (Stx)-producing Escherichia coli (STEC) are the most common causes of hemolytic uremic syndrome (STEC-HUS). The aim of our study is to compare the risk of developing STEC-HUS in relation to the type of Stx genes (Stx1, Stx2, or both). Methods: This is a prospective, observational, multicenter study involving 63 pediatric units in Northern Italy (ItalKid-HUS Network). STEC-infected children were identified within a screening program for bloody diarrhea during a 10-year period (2010\u20132019). Stx genes were detected by reverse dot blot or real-time PCR. After the identification of STEC infection, children were followed until diarrhea complete recovery for the possible development of STEC-HUS. Results: Of the 214 Stx-positive patients, 34 (15.9%) developed STEC-HUS. The risk of HUS in STEC-infected children with Stx1 (n: 62; 29.0%) and Stx2 (n: 97; 45.3%) was respectively 0% and 23.7%, while in patients carrying both Stx1 and Stx2 (n: 55; 25.7%), the risk was 12.7% (p: 0.001). Conclusions: Our data confirm that Stx1 is a very rare cause of STEC-HUS and demonstrate that the risk of STEC-HUS halves in the case of Stx1+2-producing Escherichia coli infection compared with infections where Stx2 is present alone. This observation is helpful in assessing the risk of individual STEC-infected patients for the development of HUS and suggests that Stx1, in the presence of Stx2, might exert a protective role possibly by receptor competition

Ipsilateral axillary recurrence after breast conservative surgery : the protective effect of whole breast radiotherapy

BACKGROUND AND PURPOSE: Whole breast radiotherapy (WBRT) is one of the possible reasons for the low rate of axillary recurrence after breast-conserving surgery (BCS). PATIENTS AND METHODS: We retrospectively collected data from 4,129 consecutive patients with breast cancer \u2a7d2cm and negative sentinel lymph node who underwent BCS between 1997 and 2007. We compared the risk of axillary lymph node recurrence between patients treated by WBRT (n=2939) and patients who received partial breast irradiation (PBI; n=1,190) performed by a single dose of electron intraoperative radiotherapy. RESULTS: Median tumour diameter was 1.1cm in both WBRT and PBI. Women who received WBRT were significantly younger and expressed significantly more multifocality, extensive in situ component, negative oestrogen receptor status and HER2 over-expression than women who received PBI. After a median follow-up of 8.3years, 37 and 28 axillary recurrences were observed in the WBRT and PBI arm, respectively, corresponding to a 10-year cumulative incidence of 1.3% and 4.0% (P<0.001). Multivariate analysis resulted in a hazard ratio of 0.30 (95% CI 0.17-0.51) in favour of WBRT. CONCLUSIONS: In this large series of women with T1 breast cancer and negative sentinel lymph node treated by BCS, WBRT lowered the risk of axillary recurrence by two thirds as compared to PBI

Ventilation With Argon Improves Survival With Good Neurological Recovery After Prolonged Untreated Cardiac Arrest in Pigs

Background Ventilation with the noble gas argon (Ar) has shown neuroprotective and cardioprotective properties in different in vitro and in vivo models. Hence, the neuroprotective effects of Ar were investigated in a severe, preclinically relevant porcine model of cardiac arrest. Methods and Results Cardiac arrest was ischemically induced in 36 pigs and left untreated for 12&nbsp;minutes before starting cardiopulmonary resuscitation. Animals were randomized to 4-hour post-resuscitation ventilation with: 70% nitrogen-30% oxygen (control); 50% Ar-20% nitrogen-30% oxygen (Ar 50%); and 70% Ar-30% oxygen (Ar 70%). Hemodynamic parameters and myocardial function were monitored and serial blood samples taken. Pigs were observed up to 96&nbsp;hours for survival and neurological recovery. Heart and brain were harvested for histopathology. Ten animals in each group were successfully resuscitated. Ninety-six-hour survival was 60%, 70%, and 90%, for the control, Ar 50%, and Ar 70% groups, respectively. In the Ar 50% and Ar 70% groups, 60% and 80%, respectively, achieved good neurological recovery, in contrast to only 30% in the control group (P&lt;0.0001). Histology showed less neuronal degeneration in the cortex (P&lt;0.05) but not in the hippocampus, and less reactive microglia activation in the hippocampus (P=0.007), after Ar compared with control treatment. A lower increase in circulating biomarkers of brain injury, together with less kynurenine pathway activation (P&lt;0.05), were present in Ar-treated animals compared with controls. Ar 70% pigs also had complete left ventricular function recovery and smaller infarct and cardiac troponin release (P&lt;0.01). Conclusions Post-resuscitation ventilation with Ar significantly improves neurologic recovery and ameliorates brain injury after cardiac arrest with long no-flow duration. Benefits are greater after Ar 70% than Ar 50%