Clinical studies of detecting COVID-19 from exhaled breath with electronic nose.

The COVID-19 pandemic has attracted numerous research studies because of its impact on society and the economy. The pandemic has led to progress in the development of diagnostic methods, utilizing the polymerase chain reaction (PCR) as the gold standard for coronavirus SARS-CoV-2 detection. Numerous tests can be used at home within 15 min or so but of with lower accuracy than PCR. There is still a need for point-of-care tests available for mass daily screening of large crowds in airports, schools, and stadiums. The same problem exists with fast and continuous monitoring of patients during their medical treatment. The rapid methods can use exhaled breath analysis which is non-invasive and delivers the result quite fast. Electronic nose can detect a cocktail of volatile organic com-pounds (VOCs) induced by virus infection and disturbed metabolism in the human body. In our exploratory studies, we present the results of COVID-19 detection in a local hospital by applying the developed electronic setup utilising commercial VOC gas sensors. We consider the technical problems noticed during the reported studies and affecting the detection results. We believe that our studies help to advance the proposed technique to limit the spread of COVID-19 and similar viral infections.

Challenges in the diagnosis and treatment of malaria in Polish workers returning from Africa: a case series and review of literature.

Malaria is a parasitic disease caused in humans by five species of Plasmodium: P. falciparum, P. vivax, P. malariae, P. ovale, and P. knowlesi and transmitted through a female mosquito bite. In 2020, there were 241 million cases of malaria worldwide including 627,000 deaths. Traveling to malaria endemic areas is a significant risk factor, therefore, it is very important to use non-specific and pharmacological prophylaxis. Malaria symptoms usually appear 10-14 days after infection and the disease may be suspected, based on patient examination and medical history, in patients with fever who have stayed in malaria endemic areas. The initial symptoms of the disease are not pathognomonic and it is important to remember that not all malaria patients develop a fever. A prerequisite for successful treatment of this potentially life-threatening disease is well-targeted, timely diagnosis and immediate implementation of antiparasitic therapy. Despite significant progress in the fight against malaria across the world, the disease still poses a diagnostic and therapeutic challenge, especially when it develops as a result of an imported infection and when diagnosis is complicated by the presence of other diseases. A professional group that requires special attention are maritime workers. In this study we present clinical cases of malaria which show how important it is in the clinical practice of various specialists to include malaria in the differential diagnosis of patients with fever returning from tropical regions.

Pro- and Anti-Angiogenic Factors: Their Relevance in Diabetic Foot Syndrome-A Review.

Peripheral arterial disease can involve tissue loss in up to 50% of patients with diabetic foot syndrome (DFS). Consequently, revascularization of narrowed or occluded arteries is one of the most common forms of comprehensive treatment. However, technically successful angioplasty does not always result in the healing of ulcers. The pathomechanism of this phenomenon is still not fully understood, but inadequate angiogenesis in tissue repair may play an essential role. Changes in pro- and anti-angiogenic factors among patients with DFS are not always clear and conclusive. In particular, some studies underline the role of decreased concentration of pro-angiogenic factors and higher levels of anti-angiogenic mediators. Nevertheless, there are still controversial issues, including the paradox of impaired wound healing despite high concentrations of some pro-angiogenic factors, dynamics of their expression during the healing process, and their mutual relationships. Exploring this process among diabetic patients may provide new insight into well-known methods of treatment and show their real benefits and chances for improving outcomes.

Negative pressure wound therapy affects circulating plasma microRNAs in patients with diabetic foot ulceration.

AIMS: Negative pressure wound therapy (NPWT) is commonly used in diabetic foot ulceration (DFU). The molecular mechanisms of NPWT action, particularly outside of the wound site, have not been described. We assessed NPWT's effect on circulating miRNA expression levels in type 2 diabetes (T2DM) patients with DFU. METHODS: We examined 34 T2DM patients treated with either NPWT (n = 24) or standard therapy (ST, n = 10). The group assignment was based on clinical criteria and local practice. Next-generation sequencing-based microRNA expression was determined on the patient's plasma collected before therapy and after 8 days. RESULTS: NPWT patients were similar to the ST group in terms of age, BMI, and HbA1c level; however, they differed by mean wound area (12.6 cm2 vs. 1.1 cm2 p = 0.0005). First, we analyzed the change of miRNA after NPWT or ST and observed an upregulation of let-7f-2 only in the NPWT group. Then, we analyzed the differential expression between NPWT and ST groups, looking at possible wound size effects. We found 12 differentially expressed miRNAs in pre-treatment comparison, including let-7f-2, while in post-treatment analysis we identified 28 miRNAs. The pathway enrichment analysis suggests that identified miRNAs may be involved in wound healing, particularly through angiogenesis. CONCLUSION: We found initial evidence that NPWT in T2DM patients with DFU affects miRNA expression in plasma. Additionally, some differences in plasma miRNA expression may be related to wound size.

Assessment of Electronic Sensing Techniques for the Rapid Identification of Alveolar Echinococcosis through Exhaled Breath Analysis.

Here we present a proof-of-concept study showing the potential of a chemical gas sensors system to identify the patients with alveolar echinococcosis disease through exhaled breath analysis. The sensors system employed comprised an array of three commercial gas sensors and a custom gas sensor based on WO3 nanowires doped with gold nanoparticles, optimized for the measurement of common breath volatile organic compounds. The measurement setup was designed for the concomitant measurement of both sensors DC resistance and AC fluctuations during breath samples exposure. Discriminant Function Analysis classification models were built with features extracted from sensors responses, and the discrimination of alveolar echinococcosis was estimated through bootstrap validation. The commercial sensor that detects gases such as alkane derivatives and ethanol, associated with lipid peroxidation and intestinal gut flora, provided the best classification (63.4% success rate, 66.3% sensitivity and 54.6% specificity) when sensors' responses were individually analyzed, while the model built with the AC features extracted from the responses of the cross-reactive sensors array yielded 90.2% classification success rate, 93.6% sensitivity and 79.4% specificity. This result paves the way for the development of a noninvasive, easy to use, fast and inexpensive diagnostic test for alveolar echinococcosis diagnosis at an early stage, when curative treatment can be applied to the patients.

NPWT in diabetic foot wounds-a systematic review and meta-analysis of observational studies.

PURPOSE: Negative-pressure wound therapy (NPWT) is an adjunct modality in diabetic foot ulcerations (DFUs). Randomized controlled trials (RCTs) have shown its advantage over standard approaches; however, data from observational studies remain scarce.We performed a systematic review of observational non-RCTs evaluating NPWT efficacy and safety in patients with DFU. METHODS: Electronic databases were searched for observational studies involving NPWT. The results of single-arm studies were presented as percentages of patients with the outcome of interest. A meta-analysis of comparative studies provided point estimates of outcomes. Continuous outcomes were reported as either weighted or standardized mean differences and dichotomous data as relative risks (RR). RESULTS: The search identified 16 relevant observational studies, 12 single-arm, and 4 comparative, reporting on a total of 18,449 patients with DFU, of whom 1882 were managed with NPWT. In the NPWT-treated patients, ulcers were larger (average size range 6.6-27.9 cm2), as compared with controls (≤3 cm2). The pooled results showed healing and major amputation in 51% and 5% of NPWT patients, respectively. The meta-analysis of comparative studies revealed lower risk of major amputation [RR = 0.23 (0.07; 0.80)] in NPWT-treated patients. The pooled results for healing rate and risk of any amputation were inconclusive due to large between-study heterogeneity. Overall, 6 deaths out of 158 patients were reported, none of them related to NPWT. Serious adverse events occurred in 6% of patients on NPWT. CONCLUSIONS: This systematic review of observational studies provided supportive evidence that NWPT is an efficient and safe adjunct treatment in the management of DFUs.

Effects of Negative Pressure Wound Therapy on Levels of Angiopoetin-2 and Other Selected Circulating Signaling Molecules in Patients with Diabetic Foot Ulcer.

BACKGROUND AND AIMS: Diabetic foot ulcers (DFUs) are linked to amputations and premature deaths. Negative pressure wound therapy (NPWT) has been used for DFUs. The mechanism of NPWT's action may be associated with its influence on circulating molecules. We assessed NPWT's effect on the plasma levels of angiopoietin-2 (Ang2), a key regulator of angiogenesis, and its microvesicular receptors (Tie2) as well as the microvesicles (MVs) themselves in DFU patients. MATERIALS AND METHODS: We included 69 patients with type 2 diabetes mellitus (T2DM) and neuropathic, noninfected DFUs-49 were treated with NPWT and 20 were treated with standard therapy (ST). Assigning patients to the NPWT group was not random but based on DFU characteristics, especially wound area. Ang2 was measured by ELISA in the entire group, while in a subgroup of 19 individuals on NPWT and 10 on ST, flow cytometry was used to measure Tie2+ and the corresponding isotype control (Iso+) and annexin V (AnnV+) as well as total MVs. Measurements were performed at the beginning and after 8 ± 1 days of therapy. RESULTS: Treatment groups were similar for basic characteristics but differed by their median DFU areas (10.3 (4.2-18.9) vs. 1.3 (0.9-3.4) cm2, p = 0.0001). At day 0, no difference was observed in Ang2 levels, total MVs, MV Tie+, and MV AnnV+ between the groups. Ang2 decreased after 8 days in the NPWT group, unlike in the ST group (3.54 (2.40-5.40) vs. 3.32 (2.33-4.61), p = 0.02, and 3.19 ± 1.11 vs. 3.19 ± 1.29 ng/mL, p = 0.98, respectively). No other parameters were identified that may have been influenced by the NPWT treatment. CONCLUSION: NPWT in T2DM patients with neuropathic, noninfected DFU seems to lead to reduction of the Ang2 level. Influencing the level of Ang2 may constitute one of NPWT-related mechanisms to accelerate wound healing.

Negative pressure wound therapy use in diabetic foot syndrome-from mechanisms of action to clinical practice.

BACKGROUND: Diabetes and its complications constitute a rising medical challenge. Special attention should be given to diabetic foot syndrome (DFS) due to its high rate of associated amputation and mortality. Negative pressure wound therapy (NPWT) is a frequently used supportive modality in a diabetic foot with ulcerations (DFUs). DESIGN: Here, we reviewed the current knowledge concerning the tissue and molecular mechanisms of NPWT action with an emphasis on diabetes research followed by a summary of clinical DFU studies and practice guidelines. RESULTS: Negative pressure wound therapy action results in two types of tissue deformations-macrodeformation, such as wound contraction, and microdeformation occurring at microscopic level. Both of them stimulate a wound healing cascade including tissue granulation promotion, vessel proliferation, neoangiogenesis, epithelialization and excess extracellular fluid removal. On the molecular level, NPWT results in an alteration towards more pro-angiogenic and anti-inflammatory conditions. It increases expression of several key growth factors, including vascular endothelial growth factor and fibroblast growth factor 2, while expression of inflammatory cytokinesis reduced. The NPWT application also alters the presence and function of matrix metalloproteinases. Clinical studies in DFU patients showed a superiority of NPWT over standard therapy in terms of efficacy outcomes, primarily wound healing and amputation rate, without a rise in adverse events. International guidelines point to NPWT as an important adjuvant therapy in DFU whose use is expected to increase. CONCLUSIONS: This current knowledge improves our understanding of NPWT action and its tailoring for application in diabetic patients. It may inform the development of new treatments for DFU.

Diagnosis of Human Echinococcosis via Exhaled Breath Analysis: A Promise for Rapid Diagnosis of Infectious Diseases Caused by Helminths.

Background: Human echinococcosis is a neglected infectious disease affecting more than 1 million people globally. Its diagnosis is expensive and difficult because of lack of adequate resources in low-resource locations, where most cases occur. Methods: A group of volunteers diagnosed with the 2 main types of echinococcosis and corresponding control groups were recruited from hospitals in Tunisia (32 patients with cystic echinococcosis and 43 controls) and Poland (16 patients with alveolar echinococcosis and 8 controls). Breath samples were collected from all patients and analyzed by gas chromatography coupled to mass spectrometry, and a specifically developed electronic nose system. Results: The chemical analysis revealed statistically different concentrations of 2 compounds in the breath of patients with cystic echinococcosis compared to controls, and statistically different concentrations of 7 compounds in the breath of patients with alveolar echinococcosis compared to controls. The discrimination accuracy achieved by the electronic nose system was 100% for cystic echinococcosis and 92.9% for alveolar echinococcosis, while the discrimination accuracy between these 2 patient groups was 92.1%. Conclusion: Here we advocate a noninvasive, fast, easy-to-operate and nonexpensive diagnostic tool for the diagnosis of human echinococcosis disease through exhaled breath analysis, suitable for early diagnosis and population screening.

Number of circulating pro-angiogenic cells, growth factor and anti-oxidative gene profiles might be altered in type 2 diabetes with and without diabetic foot syndrome.

AIMS/INTRODUCTION: Type 2 diabetes is often complicated by diabetic foot syndrome (DFS). We analyzed the circulating stem cells, growth factor and anti-oxidant gene expression profiles in type 2 diabetes patients without or with different forms of DFS. MATERIALS AND METHODS: Healthy volunteers (n = 13) and type 2 diabetes patients: (i) without DFS (n = 10); or with (ii) Charcot osteoneuropathy (n = 10); (iii) non-infected (n = 17); (iv) infected (n = 11); and (v) healed ulceration were examined (n = 12). Peripheral blood endothelial progenitor cells (EPC), mesenchymal stem cells (MSC), hematopoietic stem cells (HSC) and very small embryonic-like (VSEL) cells were phenotyped using flow cytometry. Plasma cytokine concentrations and gene expressions in blood cells were measured by Luminex and quantitative real-time polymerase chain reaction assays, respectively. RESULTS: Patients with non-complicated type 2 diabetes showed reduced HMOX1 expression, accompanied by HMOX2 upregulation, and had less circulating EPC, MSC or HSC than healthy subjects. In contrast, VSEL cells were elevated in the type 2 diabetes group. However, subjects with DFS, even with healed ulceration, had fewer VSEL cells, more CD45-CD29(+)CD90(+)MSC, and upregulated HMOX1 when compared with the type 2 diabetes group. Patients with Charcot osteopathy had lowered plasma fibroblast growth factor-2. Elevated plasma tumor necrosis factor-α and decreased catalase expression was found in all diabetic patients. CONCLUSIONS: Patients with type 2 diabetes and different forms of DFS have an altered number of circulating stem cells. Type 2 diabetes might also be associated with a changed plasma growth factor and anti-oxidant gene expression profile. Altogether, these factors could contribute to the pathogenesis of different forms of DFS.

Postpregnancy glycemic control and weight changes in type 1 diabetic women.

OBJECTIVE: Pregnancy in type 1 diabetes requires excellent glycemic control. Most pregnant type 1 diabetic women achieve normoglycemia; however, there is scarce data on their postdelivery characteristics. We aimed to examine postpregnancy glycemic control and weight changes in type 1 diabetes. RESEARCH DESIGN AND METHODS: We identified and followed (median 20 months) 254 women with singleton pregnancies receiving postdelivery medical care at a single institution. RESULTS: Study subjects were 28.3 ± 4.7 years of age (mean ± SD), with a diabetes duration of 12.0 ± 7.7 years. Mean A1C before conception was 6.9 ± 1.4%, and preconception weight and BMI were 64.4 ± 10.0 kg and 23.9 ± 3.3 kg/m(2), respectively. Mean A1C decreased during pregnancy, reaching 5.7 ± 0.8% in the third trimester. We observed a mean weight gain of 14.4 ± 6.5 kg during pregnancy. Within 6 months after delivery, A1C increased by 0.8% (P < 0.0001) compared with the last trimester, and body weight and BMI were 4.4 kg and 2.5 kg/m(2) higher (P < 0.0001) compared with the preconception baseline. A1C further deteriorated by 0.8% until the end of follow-up. For women in the "pregnancy planning" program (n = 117), A1C >12 months after delivery was worse compared with before conception (7.1 vs. 6.5%, P = 0.0018), whereas in women with unplanned pregnancies, it was similar to the pregestational levels (7.3 vs.7.4%, P = 0.59). Weight and BMI in the entire study group did not return to prepregnancy levels and were 2.5 kg (P = 0.0079) and 0.9 kg/m(2) higher (P = 0.0058). CONCLUSIONS: In this clinical observation, type 1 diabetic women showed postpregnancy deterioration in glycemic control and were unable to return to prepregnancy weight. Type 1 diabetic women seem to require special attention after delivery to meet therapeutic targets.