Background: Microcalorimetric bacterial growth studies have illustrated that thermograms differ significantly with both culture media and strain. The present contribution examines the possibility of discriminating between certain bacterial strains by microcalorimetry and the qualitative and quantitative contribution of the sample volume to the observed thermograms. Growth patterns of samples of Staphylococcus aureus (ATCC 25923) and Escherichia coli (ATCC 25922) were analyzed. Certain features of the thermograms that may serve to distinguish between these bacterial strains were identified. Results: The thermograms of the two bacterial strains with sample volumes ranging from 0.3 to 0.7 ml and same initial bacterial concentration were analyzed. Both strains exhibit a roughly 2-peak shape that differs by peak amplitude and position along the time scale. Seven parameters corresponding to the thermogram key points related to time and heat flow values were proposed and statistically analyzed. The most relevant parameters appear to be the time to reach a heat flow of 0.05 mW (1.67 ± 0.46 h in E. coli vs. 2.99 ± 0.53 h in S. aureus, p < 0.0001), the time to reach the first peak (3.84 ± 0.5 h vs. 5.17 ± 0.49 h, p < 0.0001) and the first peak value (0.19 ± 0.02 mW vs. 0.086 ± 0.012 mW, p < 0.0001). The statistical analysis on 4 parameters of volume-normalized heat flow thermograms showed that the time to reach a volume-normalized heat flow of 0.1 mW/ml (1.75 ± 0.37 h in E. coli vs. 2.87 ± 0.65 h in S. aureus, p < 0.005), the time to reach the first volume-normalized peak (3.78 ± 0.47 h vs. 5.12 ± 0.52 h, p < 0.0001) and the first volume-normalized peak value (0.35 ± 0.05 mW/ml vs. 0.181 ± 0.040 mW/ml, p < 0.0001) seem to be the most relevant. Peakfit® decomposition and analysis of the observed thermograms complements the statistical analysis via quantitative arguments, indicating that: (1) the first peak pertains to a faster, “dissolved oxygen” bacterial growth (where the dissolved oxygen in the initial suspension acts as a limiting factor); (2) the second peak indicates a slower “diffused oxygen” growth that involves transport of oxygen contained in the unfilled part of the microcalorimetric cell; (3) a strictly fermentative growth component may slightly contribute to the observed complex thermal signal. Conclusion: The investigated strains of Staphylococcus aureus and Escherichia coli display, under similar experimental conditions, distinct thermal growth patterns. The two strains can be easily differentiated using a selection of the proposed parameters. The presented Peakfit analysis of the complex thermal signal provides the necessary means for establishing the optimal growth conditions of various bacterial strains. These conditions are needed for the standardization of the isothermal microcalorimetry method in view of its further use in qualitative and quantitative estimation of bacterial growth.
A microcalorimetric study was carried out using a Staphylococcus epidermidis population to determine the reproducibility of bacterial growth and the variability of the results within certain experimental parameters (temperature, bacterial concentration, sample thermal history). Reproducibility tests were performed as series of experiments within the same conditions using either freshly prepared populations or samples kept in cold storage. In both cases, the samples were obtained by serial dilution from a concentrated TSB bacterial inoculum incubated overnight.
Background and Objectives: We conducted a retrospective observational study to evaluate the impact of elevated blood glucose levels in patients with SARS-CoV-2 infection and a prior diagnosis of diabetes mellitus (DM) or newly diagnosed hyperglycemia. Materials and Methods: This study analyzed 6065 patients admitted to the COVID-19 departments of the “Marius Nasta” National Institute of Pulmonology in Bucharest, Romania, between 26 October 2020 and 5 January 2023. Of these, 813 patients (13.40%) were selected for analysis due to either a pre-existing diagnosis of DM or hyperglycemia at the time of hospital admission. Results: The erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) levels were elevated in patients with blood glucose levels exceeding 300 mg/dL. These elevations correlated with the presence of respiratory failure and increased mortality rates. Additionally, oxygen requirements were significantly higher at elevated blood glucose levels (p < 0.001), with a direct relationship between glycemia and oxygen demand. This was accompanied by lower oxygen saturation levels (p < 0.001). Maximum blood glucose levels were associated with the severity of respiratory failure (AUC 0.6, 95% CI: 0.56–0.63, p < 0.001). We identified cut-off values for blood glucose at admission (217.5 mg/dL) and maximum blood glucose during hospitalization (257.5 mg/dL), both of which were associated with disease severity and identified as risk factors for increased mortality. Conclusions: High blood glucose levels, both at admission and during hospitalization, were identified as risk factors for poor prognosis and increased mortality in patients with SARS-CoV-2 infection, regardless of whether the hyperglycemia was due to a prior diagnosis of DM or was newly developed during the hospital stay. These findings underscore the importance of glycemic control in the management of hospitalized COVID-19 patients.
The coronavirus disease (COVID-19) was declared a pandemic by the World Health Organization (WHO) on March 11, 2020. Facing a new and unknown virus, the entire medical community made considerable efforts to find a specific treatment, develop guidelines, and even create a vaccine. Besides all the measures taken, a wide range of complications associated with the disease increased the mortality and morbidity rates, adding more difficulty to the management of the patients. We performed a retrospective study, including the patients with SARS-CoV-2 pneumonia who were admitted to our hospital between March 2020 and August 2021. We analyzed complications that developed during the hospitalization, such as respiratory failure or acute injury to other organs (the heart, pancreas, kidneys, and liver), and whether they were treatment- and hospitalization-related. One thousand eight hundred and forty-four cases were evaluated, and we analyzed the complications that developed during the hospitalization. Out of this, 1392 (75.48%) cases developed at least one complication during hospitalization, most frequently respiratory failure (71.14%), hyperglycemia (43.54%), renal injury (42.67%), or cardiovascular events (7.10%). SARS-CoV-2 infection in hospitalized patients with pneumonia can cause injuries to any organ, making the management of those patients even more difficult.
Pulmonary hematomas are a rare pathology. Although they are usually reported post-traumatically, there are also spontaneous forms in pulmonary pathologies or during drug therapy. In these spontaneous entities, primitive forms are rarely described, although the contributory local pulmonary pathological terrain or a specific associated medication has not yet been identified. We present the case of a patient who developed a giant pulmonary hematoma that appeared spontaneously during recovery from COVID-19 infection. It appeared in one of the two bullae-like cystic lung lesions developed during secondary COVID-19 infection. The clinical impact was major, with hypotension and anemia being observed, requiring hemodynamic support and the adjustment of drug therapy. The clinical course was favorable, with a quasi-complete resolution of both the hematoma and a second cystic lesion being observable at 8 months by pulmonary remodeling. Spontaneous pulmonary hematomas may constitute a pathological entity associated with a post-COVID-19 remodeling process of the lung and the related anticoagulant treatment, which should be recognized, especially in the actual COVID-19 pandemic or in the widespread use of anticoagulant treatment. Conservative treatment is the method of choice, even in giant lung forms.
Cancer remains one of the leading causes for death worldwide. Palliative chemotherapy is vital for certain cancer patients, highlighting the critical need for treatment monitoring tools to prevent drug accumulation and mitigate the risk of high toxicity. Therefore, our aim was to evaluate the potential of screen-printed electrodes for the development of sensitive and accurate biosensors for the detection/quantification of antineoplastic drugs. To this purpose, we developed a cisplatin sensor. By functionalizing the gold electrode with human serum albumin and by collecting the electrochemical signal obtained in a H2O2 solution, through voltammetry measurements, we were able to correlate the current measured at 430 mV with the concentration of cisplatin present in human serum samples, with a correlation coefficient of R2 = 0.99. Also, a bleomycin biosensor was developed and proven functional, but further optimization steps were employed in order to improve the accuracy. The developed biosensors have a detection range of 0.0006–43.2 mg/mL for cisplatin and 0.23–7.56 μg/mL for bleomycin in the serum samples. Our preliminary results show that these biosensors can facilitate the real-time monitoring of cisplatin and bleomycin serum levels, allowing healthcare professionals to tailor treatment strategies based on individual patient responses.