Possible Influence of Ethnicity on CT Perfusion Parameter Thresholds in Acute Ischemic Stroke

Introduction Tissue at risk, as estimated by CT perfusion utilizing Tmax+6, correlates with final infarct volume (FIV) in acute ischemic stroke (AIS) without reperfusion. Tmax thresholds are derived from Western ethnic populations but not from ethnic Asian populations. We aimed to investigate the influence of ethnicity on Tmax thresholds. Methods From a clinical-imaging registry of Australian and Indonesian stroke patients, we selected a participant subgroup with the following inclusion criteria: AIS under 24 hours and absence of reperfusion therapy. Clinical data included demographics, time metrics, stroke severity, premorbid, and 3-month Modified Rankin Score. Baseline CTP and MRI <72 hours were performed. Volumes of Tmax utilizing different thresholds and final infarct volumes (FIV) were calculated. Spearman correlation was used to evaluate relationship involving ordinal variables and calculate the optimal Tmax threshold against FIV in both populations. Results Two hundred patients were included in the study sample 100 in Jakarta and 100 in Geelong. The median National Institutes Health Stroke Scale (IQR) were 6(3-11) and 3(1-5), respectively. The median Tmax+6(IQR) was 0 (0-46.5) in Jakarta group and 0(0-7.5) in Geelong group. The median FIV(IQR) was 0 (0-30.5) and 0 (0-5.5). Tmax +8s in Jakarta population against FIV showed Spearman's coefficient =0.72, representing the optimal Tmax threshold. Tmax+6s showed Spearman's coefficient =0.51 against FIV in the Geelong population. Conclusions Tmax thresholds approximating FIV were possibly different in the Asian when compared with the non-Asian populations. Future studies are required to extend and confirm the validity of our findings.

A large primary lung abscess due to Klebsiella oxytoca: How critical the combination between early antibiotic therapy and bronchoscopy?

Lung abscess is a microbial infection that can cause necrosis of the lung tissue and formation of cavities. Antibiotics and bronchoscopy are needed in the management of large lung abscess to prevent further complications. However, some of the cases have poor clinical improvement. The aim of this case report was to describe a patient with large lung abscess who had well responded to antibiotic therapy combined with bronchoscopy drainage. We reported a 55-year-old man with a lung abscess presented with initial symptom of acute productive cough for two weeks. Chest computed tomography (CT) scan with contrast of patient indicated a massive abscess on the right lung segment with a size of 10.9 × 10.41 × 8 cm. Laboratory examination showed leukocytosis. Bronchoscopy was performed as a diagnostic and therapeutic procedure. Antibiotic resistance test was conducted from bronchoalveolar lavage sample to determine the most suitable antibiotics for the patient. The culture yielded a positive for Klebsiella oxytoca that was resistant to ampicillin and cefazolin. The bacterium was sensitive to piperacillin-tazobactam, aztreonam, ceftazidime, ceftriaxone, ertapenem, cefepime, nitrofurantoin, meropenem, amikacin, gentamicin, ciprofloxacin, tigecycline, trimethoprim- sulfamethoxazole, and levofloxacin. Levofloxacin 750 mg injection was given for 14 days followed with oral levofloxacin 500 mg once a day for four weeks and bronchoscopy to stop the microbial infection process in the lung tissues. Lung abscess reduced significantly and the patient was followed until recovered. In conclusion, early combination therapy of adequate antibiotics and bronchoscopy is effective in treating a massive lung abscess caused by Klebsiella oxytoca.

A double pre-selection method for natural background levels assessment in coastal groundwater bodies

To evaluate the chemical status of groundwater bodies (GWB) according to the European Groundwater Directive, EU Member States are required to take into account natural background levels (NBLs) where needed. Assessing the NBLs in coastal GWBs is complicated by seawater intrusion which can be amplified by groundwater withdrawals increasing the salinization of such groundwater systems. This paper proposes a new method for the NBLs assessment in coastal areas based on a double pre-selection (PS) with fixed/dynamic limits. A case study in the Apulia region, located in southeastern Italy, is proposed, where we investigated four adjacent GWBs which form the complex karst, fractured Murgia aquifer, hosted in the Jurassic-Cretaceous carbonate platform, bounded by two seas and sustained by saltwater of marine intrusion in the coastal areas. Data related to 139 monitoring stations (MSs) of the regional groundwater monitoring network were used. The first PS, "static", based on a fixed limit of anthropogenic contamination markers (NO₃ and NH₄), allows for the elimination of MSs impacted by human activities. On these, the second PS, "dynamic", based on the identification of Cl anomalous values, allows for the identification of additional MSs affected by saline contamination. The residual dataset of MSs was used for the definition of NBLs of Cl, SO₄, F and B. A statistical comparison with historical Cl observations finally allowed us to verify if the salinity of current groundwater is representative of pristine conditions. The calculated NBLs of salinity parameters are higher for the two coastal GWBs, with chloride values between 0.8 and 2 mg/L. Conversely, fluorides always show very low NBLs. The double PS approach seems more effective for NBLs calculation in coastal aquifers affected by saline contamination, where the use of a fixed Cl limit fails. It may respond to the international needs for a standardized procedure for NBL assessment.

Global CO2 emissions from dry inland waters share common drivers across ecosystems

Many inland waters exhibit complete or partial desiccation, or have vanished due to global change, exposing sediments to the atmosphere. Yet, data on carbon dioxide (CO2) emissions from these sediments are too scarce to upscale emissions for global estimates or to understand their fundamental drivers. Here, we present the results of a global survey covering 196 dry inland waters across diverse ecosystem types and climate zones. We show that their CO2 emissions share fundamental drivers and constitute a substantial fraction of the carbon cycled by inland waters. CO2 emissions were consistent across ecosystem types and climate zones, with local characteristics explaining much of the variability. Accounting for such emissions increases global estimates of carbon emissions from inland waters by 6% (~0.12 Pg C y-1). Our results indicate that emissions from dry inland waters represent a significant and likely increasing component of the inland waters carbon cycle.