Automatic air volume control system for ventilation of two patients using a single ventilator: a large animal model study.

The COVID-19 pandemic outbreak led to a global ventilator shortage. Hence, various strategies for using a single ventilator to support multiple patients have been considered. A device called Ventil previously validated for independent lung ventilation was used in this study to evaluate its usability for shared ventilation. We performed experiments with a total number of 16 animals. Eight pairs of pigs were ventilated by a ventilator or anesthetic machine and by Ventil for up to 27 h. In one experiment, 200 ml of saline was introduced to one subject's lungs to reduce their compliance. The experiments were analyzed in terms of arterial blood gases and respiratory parameters. In addition to the animal study, we performed a series of laboratory experiments with artificial lungs (ALs). The resistance and compliance of one AL (affected) were altered, while the tidal volume (TV) and peak pressure (Ppeak) in the second (unaffected) AL were analyzed. In addition, to assess the risk of transmission of pathogens between AL respiratory tracts, laboratory tests were performed using phantoms of virus particles. The physiological level of analyzed parameters in ventilated animals was maintained, except for CO2 tension, for which a permissive hypercapnia was indicated. Experiments did not lead to injuries in the animal's lungs except for one subject, as indicated by CT scan analysis. In laboratory experiments, changes in TV and Ppeak in the unaffected AL were less than 11%, except for 2 cases where the TV change was 20%. No cross-contamination was found in simulations of pathogen transmission. We conclude that ventilation using Ventil can be considered safe in patients undergoing deep sedation without spontaneous breathing efforts.

The Effect of High and Variable Glucose on the Viability of Endothelial Cells Co-Cultured with Smooth Muscle Cells.

Diabetes mellitus causes endothelial dysfunction. The aim of this study was to investigate the effect of normal (5 mmol/L), high (20 mmol/L), and fluctuating (5 and 20 mmol/L changed every day) glucose concentration in the culture medium on the viability of human umbilical vein endothelial cells (HUVECs) co-cultured with human umbilical artery smooth muscle cells (HUASMCs). The cultures were conducted on semi-permeable flat polysulfone (PSU) fibronectin-coated membranes immobilized in self-made inserts. The insert contained either HUVECs on a single membrane or HUASMCs and HUVECs on two membranes close to each other. Cultures were conducted for 7 or 14 days. Apoptosis, mitochondrial potential, and the production of reactive oxygen species and lactate by HUVECs were investigated. The results indicate that fluctuations in glucose concentration have a stronger negative effect on HUVECs viability than constant high glucose concentration. High and fluctuating glucose concentrations slow down cell proliferation compared to the culture carried out in the medium with normal glucose concentration. In conclusion, HUASMCs affect the viability of HUVECs when both types of cells are co-cultured in medium with normal or variable glucose concentration.

Dynamic Bayesian networks for prediction of health status and treatment effect in patients with chronic lymphocytic leukemia.

Chronic lymphocytic leukemia (CLL) is the most common blood cancer in adults. The course of CLL and patients' response to treatment are varied. This variability makes it difficult to select the most appropriate treatment regimen and predict the progression of the disease. This work was aimed at developing and validating dynamic Bayesian networks (DBNs) to predict changes of the health status of patients with CLL and progression of the disease over time. Two DBNs were developed and implemented i.e. Health Status Network (HSN) and Treatment Effect Network (TEN). Based on the literature data and expert knowledge we identified relationships linking the most important factors influencing the health status and treatment effects in patients with CLL. The developed networks, and in particular TEN, were able to predict probability of survival in patients with CLL, which was in line with the survival data collected in large medical registries. The networks can be used to personalize the predictions, taking into account a priori knowledge concerning a particular patient with CLL. The proposed approach can serve as a basis for the development of artificial intelligence systems that facilitate the choice of treatment that maximizes the chances of survival in patients with CLL.

Digital Planimetry With a New Adaptive Calibration Procedure Results in Accurate and Precise Wound Area Measurement at Curved Surfaces.

BACKGROUND: The purpose of this study was to determine the accuracy of wound area measurement at a curved surface using a digital planimetry (DP) with the newly proposed adaptive calibration. METHODS: Forty wound shapes were printed and placed at the side surfaces of cylinders with diameters of 9.4 and 6.2 cm. Area measurements were carried out using a commercial device SilhouetteMobile (Aranz, New Zealand) and the planimetric app Planimator. Planimetric area measurements were carried out using 2 one-dimensional calibration markers placed above and below the wound shape. The method of adaptive calibration for DP was described. Reference area values of wound shapes were obtained by pixel counting on digital scans made with an optical scanner. Relative errors (REs) and relative differences (RDs) for area measurements were analyzed. RESULTS: The median of REs for the DP with adaptive calibration (DPwAC) was equal to 0.60% and was significantly smaller than the median for the SilhouetteMobile device (SMD) (2.65%), and significantly smaller than the median for the DP (2.23%). The SD of RDs for the DPwAC of 0.87% was considerably lower than for the SMD (6.45%), and for the DP without adaptive calibration (2.51%). The mean of RDs for the DPwAC (0.082%) was not significantly different from zero, which means that the systematic error was not present for the DPwAC. CONCLUSIONS: The use of the adaptive calibration in DP to measure the areas at curved surface resulted in a significant increase of accuracy and precision, and removal of systematic error. The DPwAC revealed 4.4 times lower error and 7.4 times higher precision of area measurement at curved surfaces than the SMD.

NLRP3 Inflammasome at the Interface of Inflammation, Endothelial Dysfunction, and Type 2 Diabetes.

Type 2 diabetes mellitus (T2DM), accounting for 90-95% cases of diabetes, is characterized by chronic inflammation. The mechanisms that control inflammation activation in T2DM are largely unexplored. Inflammasomes represent significant sensors mediating innate immune responses. The aim of this work is to present a review of links between the NLRP3 inflammasome, endothelial dysfunction, and T2DM. The NLRP3 inflammasome activates caspase-1, which leads to the maturation of pro-inflammatory cytokines interleukin 1ß and interleukin 18. In this review, we characterize the structure and functions of NLRP3 inflammasome as well as the most important mechanisms and molecules engaged in its activation. We present evidence of the importance of the endothelial dysfunction as the first key step to activating the inflammasome, which suggests that suppressing the NLRP3 inflammasome could be a new approach in depletion hyperglycemic toxicity and in averting the onset of vascular complications in T2DM. We also demonstrate reports showing that the expression of a few microRNAs that are also known to be involved in either NLRP3 inflammasome activation or endothelial dysfunction is deregulated in T2DM. Collectively, this evidence suggests that T2DM is an inflammatory disease stimulated by pro-inflammatory cytokines. Finally, studies revealing the role of glucose concentration in the activation of NLRP3 inflammasome are analyzed. The more that is known about inflammasomes, the higher the chances to create new, effective therapies for patients suffering from inflammatory diseases. This may offer potential novel therapeutic perspectives in T2DM prevention and treatment.

Insulin in Type 1 and Type 2 Diabetes-Should the Dose of Insulin Before a Meal be Based on Glycemia or Meal Content?

The aim of this review was to investigate existing guidelines and scientific evidence on determining insulin dosage in people with type 1 and type 2 diabetes, and in particular to check whether the prandial insulin dose should be calculated based on glycemia or the meal composition, including the carbohydrates, protein and fat content in a meal. By exploring the effect of the meal composition on postprandial glycemia we demonstrated that several factors may influence the increase in glycemia after the meal, which creates significant practical difficulties in determining the appropriate prandial insulin dose. Then we reviewed effects of the existing insulin therapy regimens on glycemic control. We demonstrated that in most existing algorithms aimed at calculating prandial insulin doses in type 1 diabetes only carbohydrates are counted, whereas in type 2 diabetes the meal content is often not taken into consideration. We conclude that prandial insulin doses in treatment of people with diabetes should take into account the pre-meal glycemia as well as the size and composition of meals. However, there are still open questions regarding the optimal way to adjust a prandial insulin dose to a meal and the possible benefits for people with type 1 and type 2 diabetes if particular parameters of the meal are taken into account while calculating the prandial insulin dose. The answers to these questions may vary depending on the type of diabetes.

Accuracy of Automatic Carbohydrate, Protein, Fat and Calorie Counting Based on Voice Descriptions of Meals in People with Type 1 Diabetes.

The aim of this work was to assess the accuracy of automatic macronutrient and calorie counting based on voice descriptions of meals provided by people with unstable type 1 diabetes using the developed expert system (VoiceDiab) in comparison with reference counting made by a dietitian, and to evaluate the impact of insulin doses recommended by a physician on glycemic control in the study’s participants. We also compared insulin doses calculated using the algorithm implemented in the VoiceDiab system. Meal descriptions were provided by 30 hospitalized patients (mean hemoglobin A1c of 8.4%, i.e., 68 mmol/mol). In 16 subjects, the physician determined insulin boluses based on the data provided by the system, and in 14 subjects, by data provided by the dietitian. On one hand, differences introduced by patients who subjectively described their meals compared to those introduced by the system that used the average characteristics of food products, although statistically significant, were low enough not to have a significant impact on insulin doses automatically calculated by the system. On the other hand, the glycemic control of patients was comparable regardless of whether the physician was using the system-estimated or the reference content of meals to determine insulin doses.

Response of human normal and leukemia cells to factors released by amnion fragments in vitro.

Amnion is a membrane surrounding the embryo/fetus which determine growth factors and interleukins with angiogenic, immunogenic, and anti-inflammatory properties. The aim of the present study was to investigate the effects of conditioned culture medium from 24-h cultures of human amnion (hAM CCM) on migration and proliferation of human umbilical vein endothelial primary cells (HUVECs), freshly isolated bone marrow mononuclear cells (BM MNCs), and Jurkat leukemia cell line. Amnion membrane was freshly isolated from healthy placenta and its fragments cultured in vitro to produce hAM CCM. Members of the IGFBP protein family made up one third of all assayed proteins present in the hAM medium. The hAM CCM did not affect the proliferation rate of HUVECs or MNCs, but we observed more intensive migration of those cells, and lower expression of CD31 surface antigen on HUVECs as compared to control cultures. In contrast, Jurkat cells did not respond to hAM CCM treatment by proliferation or mobility change. The conditioned medium from 24-h cultures of human amnion is easy to obtain and is a convenient source of various growth and other factors that may be useful in practical medicine.

Efficacy of automatic bolus calculator with automatic speech recognition in patients with type 1 diabetes: A randomized cross-over trial.

BACKGROUND: Patients using an insulin pump as part of their diabetes treatment need to calculate insulin bolus doses to compensate for a meal. Some patients do not modify their meal boluses according to changes in the amount and composition of food products in a meal. The lack of correct meal boluses leads to unstable, and therefore harmful, blood glucose levels. The aim of the present study was to test a system supporting bolus determination based on a voice description of a meal. METHODS: The bolus calculator developed (VoiceDiab) consists of a smartphone application and three remote servers for automatic speech recognition, text analysis, and insulin dosage calculation. Forty-four people with type 1 diabetes (T1D) treated with continuous subcutaneous insulin infusion finished the randomized cross-over study. Patients were randomly allocated to the group in which the VoiceDiab system supported bolus calculation or to an unsupported group, in which patients or their caregivers calculated boluses. After a 14-day washout period, patients from the supported group were switched to the unsupported group, whereas those in the unsupported group were switched to the supported group. RESULTS: There was a significant difference between the supported and unsupported groups in the percentage of patients with 2-h postprandial glycemia within the 70-180 mg/dL range (58.6% vs 46.6%, respectively; P = 0.031). CONCLUSIONS: The VoiceDiab system improves postprandial glucose control without increasing the time in hyperglycemia or hypoglycemia. Therefore, it may be useful in the treatment of patients with diabetes on intensive insulin therapy.

Analysis: A Step Toward Standardizing Diabetic Foot Images.

In this issue of Journal of Diabetes Science and Technology Yap and coauthors report on the design and present results from a reliability study of the application called FootSnap that is intended for standardization of the distance and the orientation of the camera relative to the diabetic foot that is photographed. To produce standardized photographs FootSnap uses a straightforward, yet original and useful method. However, other systems have been reported and clinically tested earlier, in which the same parameters of foot images might be standardized and which are free of some limitations of FootSnap. Nevertheless, FootSnap should contribute to increase clarity of documenting changes in the diabetic foot shape, texture color and lesions, and it should facilitate application of automatic image processing algorithms.

The First Use of Bolus Calculator With Speech Analyzer.

BACKGROUND: The insulin therapy in type 1 diabetes involves a wide array of restrictions in patients and their families. One of those is a difficulty in estimation of the insulin dose programmed for each meal. The purpose of the study is an assessment of functionalities related to the expert system VoiceDiab-a calculator of meal boluses. METHODS: The sample group composed of 54 patients, aged 3-52, all suffering from type 1 diabetes, treated with the insulin pump, taking part in the clinics RCT (for adults and a pediatrician), with a randomized allocation to a surveyed group and cross-over. The research methodology was based upon questionnaires and open-ended questions. RESULTS: 40% of respondents recognized the application's usefulness as high (18 of 47), giving it 10 points, and easy to use (70%). Disadvantages of this app comprised lack of some products in the application database (n = 23), troubles with the mobile range ( n = 4), and no option of a manual data input for processing purposes (n = 23). Advantages, that have been mentioned the most frequently included facilitation of measurements (n = 7), enhanced life quality of the patient (n = 8), and a guarantee of prompt and thorough calculations (n = 22). Of the surveyed individuals, 50% reached their diet, while 100% gave a top grade to the application, claiming it had contributed to a more efficient metabolic control. CONCLUSION: The pilot scheme of the expert system VoiceDiab has potential to become an application, facilitating dosing of the meal insulin and improving the comfort and safety of insulin administering. However, it needs to be modified, as mentioned by the users who have tested the system.

A Randomized Controlled Study of an Insulin Dosing Application That Uses Recognition and Meal Bolus Estimations.

BACKGROUND: Throughout the insulin pump therapy, decisions of prandial boluses programming are taken by patients individually a few times every day, and, moreover, this complex process requires numerical skills and knowledge in nutrition components estimation. The aim of the study was to determine the impact of the expert system, supporting the patient's decision on meal bolus programming, on the time in range of diurnal glucose excursion in patients treated with continuous subcutaneous insulin infusion (CSII). METHODS: The crossover, randomized study included 12 adults, aged 19 to 53, with type 1 diabetes mellitus, duration ranging from 7 to 30 years. Patients were educated in complex food counting, including carbohydrate units (CU) and fat-protein units (FPU). Subsequently, they were randomly allocated to the experimental group (A), which used the expert software named VoiceDiab, and the control group (B), using a manual method of meal-bolus estimation. RESULTS: It was found that 66.7% of patients within the A group statistically reported a relevant increase in the percentage (%) of sensor glucose (SG) in range (TIR 70-180 mg/dl), compared to the B group. TIR (median) reached 53.9% in the experimental group (A) versus 44% within the control group (B), P < .05. The average difference in the number of hypoglycemia episodes was not statistically significant (-0.2%, SD 11.6%, P = .93). The daily insulin requirement in both groups was comparable-the average difference in total daily insulin dose between two groups was 0.26 (SD 7.06 IU, P = .9). CONCLUSION: The expert system in meal insulin dosing allows improvement in glucose control without increasing the rates of hypoglycemia or the insulin requirement.

Human endothelial cells hollow fiber membrane bioreactor as a model of the blood vessel for in vitro studies.

Human endothelial cells are used in experimental models for studying in vitro pathophysiological mechanisms of different diseases. We developed an original bioreactor, which can simulate human blood vessel, with capillary polysulfone membranes covered with the human umbilical vein endothelial cells (HUVECs) and we characterized its properties. The elaborated cell seeding and culturing procedures ensured formation of a confluent cell monolayer on the inside surface of capillaries within 24 h of culturing under the shear stress of 6.6 dyn/cm(2). The optimal density of cells to be seeded was 60,000 cells/cm(2). Labeling HUVECs with carboxyfluorescein succinimidyl ester (CFSE) did not influence cells' metabolism. Flow cytometry-based analysis of HUVECs stained with CFSE demonstrated that in a presence of the shear stress cells' proliferation was much inhibited (after 72 h proliferation index was equal to 1.9 and 6.2 for cultures with and without shear stress, respectively) and the monolayer was formed mainly due to migration and spreading of cells that were physiologically elongated in a direction of the flow. Monitoring of cells' metabolism showed that HUVECs cultured in a presence of the shear stress preferred anaerobic metabolism and they consumed 1.5 times more glucose and produced 2.3 times more lactate than the cells cultured under static conditions. Daily von Willebrand factor production by HUVECs was near 2 times higher in a presence of the shear stress. The developed model can be used for at least 3 days in target studies under conditions mimicking the in vivo state more closely than the static HUVEC cultures.

Wound Area Measurement with Digital Planimetry: Improved Accuracy and Precision with Calibration Based on 2 Rulers.

INTRODUCTION: In the treatment of chronic wounds the wound surface area change over time is useful parameter in assessment of the applied therapy plan. The more precise the method of wound area measurement the earlier may be identified and changed inappropriate treatment plan. Digital planimetry may be used in wound area measurement and therapy assessment when it is properly used, but the common problem is the camera lens orientation during the taking of a picture. The camera lens axis should be perpendicular to the wound plane, and if it is not, the measured area differ from the true area. RESULTS: Current study shows that the use of 2 rulers placed in parallel below and above the wound for the calibration increases on average 3.8 times the precision of area measurement in comparison to the measurement with one ruler used for calibration. The proposed procedure of calibration increases also 4 times accuracy of area measurement. It was also showed that wound area range and camera type do not influence the precision of area measurement with digital planimetry based on two ruler calibration, however the measurements based on smartphone camera were significantly less accurate than these based on D-SLR or compact cameras. Area measurement on flat surface was more precise with the digital planimetry with 2 rulers than performed with the Visitrak device, the Silhouette Mobile device or the AreaMe software-based method. CONCLUSION: The calibration in digital planimetry with using 2 rulers remarkably increases precision and accuracy of measurement and therefore should be recommended instead of calibration based on single ruler.

A network meta-analysis of progression free survival and overall survival in first-line treatment of chronic lymphocytic leukemia.

BACKGROUND: A limited evidence exists regarding comparisons of clinical effectiveness of available therapies for first-line treatment of chronic lymphocytic leukemia (CLL). METHODS: We compared available therapies for treatment-naïve, symptomatic CLL regarding progression free survival (PFS) and overall survival (OS) in all the identified random control trials and in subgroups composed of younger/fit and older/unfit patients, using a Bayesian network meta-analysis. RESULTS: In younger/fit patients we obtained median of projected mean PFS of: 19, 26, 31, 43, 51 and 75months for chlorambucil, fludarabine, alemtuzumab, fludarabine with cyclophosphamide (FC), bendamustine and fludarabine with cyclophosphamide and rituximab (FCR), respectively. We noted median OS of: 59, 66, 66, 70months for FC, chlorambucil, FCR and fludarabine, respectively. In older/unfit patients we noted PFS of: 16, 17, 24, 30, 60months for chlorambucil, fludarabine and chlorambucil with ofatumumab (OClb) or rituximab (RClb) or obinutuzumab (GClb), respectively. We obtained median OS of: 44, 58, 59 and 90months for fludarabine, RClb, chlorambucil and GClb, respectively. CONCLUSIONS: Our results suggest that: (1) FCR has higher potential of preventing CLL progression in younger/fit patients over four therapy options, which were subject of previous meta-analysis but also over bendamustine; (2) in these patients FCR does not entail prolonging of OS in comparison with chlorambucil and it is outperformed by fludarabine; (3) in older/unfit patients GClb demonstrates longer projected PFS than all assessed comparators; (4) in this group GClb has also the highest potential of increasing OS.

Validation of a hemoglobin A1c model in patients with type 1 and type 2 diabetes and its use to go beyond the averaged relationship of hemoglobin A1c and mean glucose level.

BACKGROUND: Glycated hemoglobin A1c (HbA1c) has been used as an index of glycemic control in the management, guidance, and clinical trials of diabetic patients for the past 35 years. The aim of this study was to validate the HbA1c model in patients with type 1 and type 2 diabetes and to use it to support interpretation of HbA1c in different clinical situations. METHODS: The HbA1c model was identified in 30 patients (15 with type 1 diabetes and 15 with type 2 diabetes) by estimating the overall glycation rate constant (k), based on results of continuous glucose monitoring. The model was validated by assessing its ability to predict HbA1c changes in cultures of erythrocytes in vitro and to reproduce results of the A1C-Derived Average Glucose (ADAG) study. The model was used to simulate the influence of different glucose profiles on HbA1c. RESULTS: The mean k was equal to 1.296 ± 0.216 × 10(-9) l mmol(-1) s(-1) with no difference between type 1 and type 2 diabetes. The mean coefficient of variation of k was equal to 16.7%. The model predicted HbA1c levels in vitro with a mean absolute difference less than 0.3% (3.3 mmol/mol). It reproduced the linear relationship of HbA1c and mean glucose levels established in the ADAG study. The simulation experiments demonstrated that during periods of unstable glycemic control, glycemic profiles with the same mean glucose might result in much different HbA1c levels. CONCLUSIONS: Patients with type 1 and type 2 diabetes are characterized by the same mean value of k, but there is considerable interindividual variation in the relationship of HbA1c and mean glucose level. Results suggest that reciprocal changes in glycation rate and the life span of erythrocytes exist in a wide range of HbA1c values. Thus, for an average patient with diabetes, no modifications of parameters of the glycation model are required to obtain meaningful HbA1c predictions. Interpreting HbA1c as a measure of the mean glucose is fully justified only in the case of stable glycemia. The model and more frequent tests of HbA1c might be used to decrease ambiguity of interpreting HbA1c in terms of glycemic control.