Predicting acute kidney injury onset with a random forest algorithm using electronic medical records of COVID-19 patients: the CRACoV-AKI model.

INTRODUCTION: Acute kidney injury (AKI) is a serious and common complication of SARS­CoV­2 infection. Most risk assessment tools for AKI have been developed in the intensive care unit or in elderly populations. As the COVID­19 pandemic is transitioning into an endemic phase, there is an unmet need for prognostic scores tailored to the population of patients hospitalized for this disease. OBJECTIVES: We aimed to develop a robust predictive model for the occurrence of AKI in hospitalized patients with COVID­19. PATIENTS AND METHODS: Electronic medical records of all adult inpatients admitted between March 2020 and January 2022 were extracted from the database of a large, tertiary care center with a reference status in Lesser Poland. We screened 5806 patients with SARS­CoV­2 infection confirmed with a polymerase chain reaction test. After excluding individuals with lacking data on serum creatinine levels and those with a mild disease course (<7 days of inpatient care), a total of 4630 records were considered. Data were randomly split into training (n = 3462) and test (n = 1168) sets. A random forest model was tuned with feature engineering based on expert advice and metrics evaluated in nested cross­validation to reduce bias. RESULTS: Nested cross­validation yielded an area under the curve ranging between 0.793 and 0.807, and an average performance of 0.798. Model explanation techniques from a global perspective suggested that a need for respiratory support, chronic kidney disease, and procalcitonin concentration were among the most important variables in permutation tests. CONCLUSIONS: The CRACoV­AKI model enables AKI risk stratification among hospitalized patients with COVID­19. Machine learning-based tools may thus offer additional decision­making support for specialist providers.

The effectiveness of surgical treatment of lung cancer in Polish academic and nonacademic centers.

Background: The theoretical advantage of academic hospitals over nonacademic are: more qualified surgeons, adequate diagnostic facilities and infrastructure, including intensive care units. The aim of the study was to compare the effectiveness of surgical lung cancer treatment in academic (ACA) and nonacademic (non-ACA) centers. Methods: This was a retrospective analysis of data from 31,777 patients surgically-treated for lung cancer during the period from 2007 to 2020 in 9 ACA and 21 non-ACA centers. The analysis considered the clinical data of patients, the effectiveness of preoperative diagnostics, the type of procedures performed, the complications, the postoperative mortality and the long-term survival. Results: The median number of anatomical lung resection procedures was 1,218 for ACA and 550 for non-ACA centers. In the ACA group, resection using the video-assisted thoracic surgery (VATS) technique was performed significantly more often than in the non-ACA group (23.6% vs. 14.2%, P<0.001). The pN feature analysis showed significantly lower proportions of pNX (9.2%) in the ACA group than those in the non-ACA group (17.1%) (P<0.001). The rates of postoperative complications in the ACA and non-ACA groups were 30.7% and 33.8%, respectively (P<0.001). There were no significant differences in 5-year survival between the ACA and non-ACA groups (56% and 56%, respectively) (P=0.2). Conclusions: The present study showed that ACA centers are characterized by better preoperative diagnostics, a higher percentage of VATS lobectomies, a lower percentage of postoperative complications and a shorter hospitalization period than non-ACA centers, but there was no impact on 5-year survival.

COVID-19 Vaccines over Three Years after the Outbreak of the COVID-19 Epidemic.

The outbreak of COVID-19 started in December 2019 and spread rapidly all over the world. It became clear that the development of an effective vaccine was the only way to stop the pandemic. It was the first time in the history of infectious diseases that the process of the development of a new vaccine was conducted on such a large scale and accelerated so rapidly. At the end of 2020, the first COVID-19 vaccines were approved for marketing. At the end of March 2023, over three years after the outbreak of the COVID-19 pandemic, 199 vaccines were in pre-clinical development and 183 in clinical development. The candidate vaccines in the clinical phase are based on the following platforms: protein subunit, DNA, RNA, non-replication viral vector, replicating viral vector, inactivated virus, virus-like particles, live attenuated virus, replicating viral vector combined with an antigen-presenting cell, non-replication viral vector combined with an antigen-presenting cell, and bacterial antigen-spore expression vector. Some of the new vaccine platforms have been approved for the first time for human application. This review presents COVID-19 vaccines currently available in the world, procedures for assurance of the quality and safety of the vaccines, the vaccinated population, as well as future perspectives for the new vaccine platforms in drug and therapy development for infectious and non-infectious diseases.

The absence of lymph nodes removed (pNx status) impacts survival in patients with lung cancer treated surgically.

OBJECTIVES: We aimed to study the clinical significance of the lack of lymph node assessment (pNx status) and its impact on survival in non-small-cell lung cancer patients. METHODS: We retrospectively analysed the Polish Lung Cancer Study Group database. pNx status was defined as 0 lymph nodes removed. We included 17,192 patients. RESULTS: A total of 1080 patients (6%) had pNx status. pNx patients were more likely to be younger, be female, have a different pT distribution, have squamous cell carcinoma, undergo open thoracotomy, be operated on in non-academic hospitals, and have a lower rate of some comorbidities. pNx was more likely to be cN0 than pN1 and pN2 but less likely than pN0 (p < 0.001). pNx patients were less likely to undergo preoperative invasive mediastinal diagnostics than pN1 and pN2 patients but more likely than pN0 patients (p < 0.001). Overall, the five-year overall survival rates were 64%, 45%, 32% and 50% for pN0, pN1, pN2 and pNx, respectively. In pairwise comparisons, all pN descriptors differed significantly from each other (all p < 0.0001 but pNx vs. pN1 p = 0.016). The placement of the pNx survival curve and survival rate depended on histopathology, surgical approach and pT status. In multivariable analysis, pNx was an independent prognostic risk factor (HR = 1.37, 95%CI: 1.23-1.51, p < 0.01). CONCLUSION: The resection of lymph nodes in lung cancer remains a crucial step in the surgical treatment of this disease. The survival of pNx patients is similar to that of pN1 patients. pNx survival curve placement depends on the other variables which could be useful in clinical decisions.

Sex differences in clinico-pathologic characteristics and long-term survival among 17,192 surgically treated NSCLC patients: Nationwide population-based propensity score-matching study.

INTRODUCTION: More information is needed on gender differences in lung cancer surgery. Thus, we conducted a retrospective study on thoracic treatment of non-small cell lung cancer (NSCLC) patients between 2007 and 2020 in Poland. The aim was to characterize sex differences in survival after complete surgical resection and to compare postoperative complications between Polish men and women. The main aspects that were compared between women and men were as follows: type of surgery and postoperative staging, morbidity and mortality, thoracic surgery complications, comorbidities, and overall survival based on a univariate analysis including propensity score matching (PSM) and a multivariate analysis. MATERIALS AND METHODS: Data were collected retrospectively from the Polish Lung Cancer Study Group database. Patients who were surgically treated for NSCLC between 2007 and 2020 (n = 17,192) were included in the study. RESULTS: The univariate analysis showed significantly better survival in women than in men. Women had better 5-year survival compared to men both for adenocarcinoma and squamous cell carcinoma (66% vs. 53%, p < 0.0001 and 65% vs. 51%, p<0.0001%, respectively), for both smokers and non-smokers (65% vs. 52%, p < 0.0001 and 65% vs. 51%, p < 0.0001, respectively), all age groups, and all stages (IA1 to III B). In the PSM analysis, statistically significant differences in favor of women were found for lower lobectomy (67% vs. 50%, p < 0.0001) and upper lobectomy (67% vs. 56%, p < 0.0001). Overall, postoperative complications occurred in 33.1% of patients and were observed more often in men than in women (35.8% vs. 28.6%, p < 0.001). CONCLUSIONS: Women with NSCLC who were treated surgically had a better long-term outcome compared to men, with no significant difference in disease severity. In addition to gender, the histological type, comorbidities, and type of surgery and surgical approach are also important.

Effect of 3A lymph node resection on survival in patients with right-sided NSCLC: a retrospective, multicentre, propensity-score matching study.

Background: We aimed to assess the clinical significance and impact on survival of prevascular mediastinal lymph nodes (3A) in patients with right-sided lung cancer. Methods: Prospective data of 6,348 patients, who underwent lung resection from 2005 to 2015, were retrospectively analysed. There were 221 patients who underwent 3A dissection (3ALN+), while 6,127 did not (3ALN-). We performed propensity score matching (PSM) to decrease selection bias (221 vs. 221). Results: The incidence of 3A metastasis was 8%, and it elevated with pT stage. Between pT1c and pT2a, there was a significant increase in the 3A metastasis incidence, which doubled from 4% to 9%. For pT4, the incidence was 15%. The highest incidence was found among patients undergoing pneumonectomy (10%) and in the N2b1 and N2b2 subgroups (33% and 64%). In univariable analysis, we found no differences in 5-year survival between 3ALN+ and 3ALN- (51% vs. 51%, P=0.74). But, non-metastatic 3ALN+, 3ALN-, and metastatic 3ALN+ differed significantly (P<0.0001). pN2 subgroups (pN2a1, pN2a2, pN2b1, pN2b2) within PSM analysis did not differ significantly in terms of survival. 3A metastasis failed to be an independent prognostic factor in the multivariable analysis of matched pN2 subgroups. Conclusions: Regardless of 3A lymph nodes failing to be an independent prognostic factor in our cohort, the incidence of metastases in lymph nodes increases notably in advanced stages. 3A metastasis rate is comparable to other lymph node stations. Therefore, superior mediastinal lymphadenectomy in advanced cancers may improve from resections of the 3A lymph node station.

Solitary Extramedullary Plasmacytoma of the Larynx and Secondary Laryngeal Involvement in Plasma Cell Myeloma: Single-Centre Retrospective Analysis and Systematic Literature Review.

The involvement of the larynx in plasma cell myeloma (PCM) may manifest as solitary extramedullary plasmacytoma of the larynx (sEMP-L) or as infiltration of the larynx during newly diagnosed or relapsed systemic disease with bone marrow involvement (plasma cell myeloma with laryngeal involvement, PCM-L). To increase knowledge about these rare conditions, we performed a retrospective analysis along with a comprehensive literature review of cases of sEMP-L or PCM-L. Six patients (two sEMP-L and four PCM-L) were identified in our tertiary laryngological centre from 2009 to 2021, constituting 0.88% of all malignant laryngeal tumours. The literature search yielded 187 cases, including 152 sEMP-L and 35 sPCM-L. A comparison of baseline characteristics between sEMP-L and PCM-L performed in the combined cohort of cases from literature review and retrospective analysis revealed that patients with sEMP-L were younger (56 vs. 64 years, p ≤ 0.001) and presented less commonly with thyroid or cricoid cartilage involvement (2.2% vs. 30.8%, p ≤ 0.001). The prognosis of sEMP-L was better than PCM-L (overall survival 86% vs. 55% at 5 years, p = 0.002). Analysis of potential factors that could influence progression-free survival (PFS) in the group of sEMP-L revealed that male sex and cartilage involvement negatively affected PFS in univariate analyses, while only cartilage involvement retained statistical significance in multivariate analysis (HR = 19.94, p = 0.024). In conclusion, PCM with laryngeal involvement is sporadic. Secondary involvement of the larynx during PCM might be more common than sEMP-L and is associated with worse survival. The involvement of cartilage adversely influences the outcome of sEMP-L.

Evaluation of precipitation time of the aluminum salts adsorbed potentially frozen vaccines used in the Polish National Immunization Schedule for their pre-qualification before the administration.

Purpose: Vaccines adsorbed on aluminum adjuvants irreversibly lose potency after freezing and their safety is affected. To prevent the administration of such vaccines, the World Health Organization developed the Shake Test designed to determine whether adsorbed vaccines have been frozen or not. However, the Shake Test is difficult and time-consuming when routinely conducted at the place of vaccination. In this study, a modified shake test for prequalification of potentially frozen vaccines was elaborated. Materials and Methods: Vaccines used in the Polish Immunization Schedule were investigated and the analysis includes an assessment of precipitation time and the influence of the container type, amount and type of aluminum compound, and a volume of vaccine dose on the precipitation time. Results: Significant differences between the precipitation time of frozen and non-frozen vaccines routinely used in the Polish Immunization Schedule were observed. The precipitation time of all non-frozen vaccines was above 30 minutes. The longest precipitation time of frozen vaccines was 10 minutes. Conclusion: The finding of the study can be used in practice by the personnel administering vaccines to patients. Step-by-step recommendations for the preparation of the test have been proposed in the article.

Outcomes of the two generations of bioresorbable scaffolds (Magmaris vs. Absorb) in acute coronary syndrome in routine clinical practice.

BACKGROUND: Acute coronary syndrome (ACS) as a clinical manifestation of coronary artery disease (CAD) remains a significant cause of mortality and morbidity, as reported worldwide annually. The second generation of drug-eluting stents (DES) is a gold standard in percutaneous interventions in ACS patients however, permanent caging of the vessel with metallic DES has some drawbacks. Bioresorbable vascular scaffolds (BRS) were designed as a temporal vessel-supporting technology allowing for anatomical and functional restoration. Nevertheless, following the initial encouraging reports, numerous concerns about the safety of BRS occurred. METHODS: In this study, a 1-year performance of 193 patients with magnesium BRS - Magmaris (Biotronik, Berlin, Germany) was evaluated in comparison to 160 patients with polymer BRS - Absorb (Abbott-Vascular, Chicago, USA) in the non-ST-segment elevation-ACS setting. RESULTS: The Magmaris, when compared to Absorb showed a significantly lower rate of primary endpoint (death from cardiac causes, myocardial infarction, stent thrombosis) as well as target lesion failure in 30-day and 1 year follow-up. In the Absorb group, a significantly higher rate of stent thrombosis was observed. CONCLUSIONS: Data from the present study suggests encouraging safety a profile and more favorable clinical outcomes of Magnesium BRS in comparison to the polymer Absorb - BRS.

Magnesium Bioresorbable Scaffold (BRS) Magmaris vs Biodegradable Polymer DES Ultimaster in NSTE-ACS Population-12-Month Clinical Outcome.

Background: Percutaneous coronary intervention (PCI) in the acute coronary syndrome (ACS) setting is associated with a greater probability of device failure. The currently ongoing development of new scaffold technologies has concentrated an effort on improving the PCI outcomes, including the use of new biodegradable materials. This pilot study evaluates the performance of a magnesium bioresorbable scaffold (Magmaris, Biotronik, Germany) in comparison to the sirolimus-eluting bioresorbable polymer stents (BP-SES) (Ultimaster, Terumo, Japan) in the NSTE-ACS setting. Methods: The population of this pilot comprised 362 patients assigned to one of two arms (193-Magmaris vs 169-Ultimaster). The data regarding the primary outcome comprised of death from cardiac causes, myocardial infarction, and stent thrombosis, along with target-lesion failure (TLF) and other clinical events was collected in the 1-yearfollow-up. Results: There were no statistically significant differences in clinical outcomes in the short term (30 days) or in the 1-yearfollow-up between both groups. Conclusion: At 12 months, there were no statistically significant differences between the Magmaris and Ultimaster for composed endpoints or the TLF.

The clinico-pathological characteristics of surgically treated young women with NSCLC.

Background: Non-small cell lung cancer diagnosed in young patients is rare. Younger patients with lung cancer are mostly female and have a more advanced stage at initial diagnosis. To our knowledge, no studies have compared single-surgical treatment in different age groups among women. Our study aimed to elucidate the clinicopathological characteristics and the best strategies for surgically treating young women with non-small-cell lung cancer. Methods: The data were collected retrospectively from the Polish Lung Cancer Study Group database. Women who were surgically treated for non-small-cell lung cancer between 2007 and 2020 were included in the study. The participants (n=11,460) were divided into two subgroups: aged ≤55 and >55 years. Results: Statistically significant differences were found for grades IB, IIA, IIIA, and IIIB (22.8% vs. 24.5%, 5.3% vs. 7.5%, 19.3% vs. 15.8%, 5.8% vs. 3.2%, for younger and older women, respectively, all P<0.001). The univariate analysis showed a higher percentage of 5-year survival in the group of younger women than in older women (0.67 vs. 0.64, P=0.00076). Regarding the stage of advancement, statistically significant differences in survival were found for stages IA1, IA2, and IIIA (0.95 vs. 0.86, P=0.047; 0.88 vs. 0.79, P=0.003; 0.5 vs. 0.42, for younger and older women, respectively, all P=0.01). Postoperative complications were more common in older than younger women (27.6% vs. 23.1%, P<0.001). However, there were no statistically significant differences in the number of hospitalization days since surgery and postoperative 30-day mortality. Conclusions: Younger women treated surgically were characterized by a lower percentage of comorbidities, were treated in a more advanced stage of the disease and had a lower percentage of postoperative complications, which, however, did not affect the hospitalization time. Despite the more advanced stage of the disease, survival in selected stages was much better than in the group of older women.

Biodegradable Polymer DES (Ultimaster) vs. Magnesium Bioresorbable Scaffold (BRS Magmaris) in Diabetic Population with NSTE-ACS: A One-Year Clinical Outcome of Two Sirolimus-Eluting Stents.

BACKGROUND: Cardiovascular disease (CVD) with significant involvement of coronary artery disease (CAD) remains a major cause of death and disability among the diabetic population. Although percutaneous coronary intervention (PCI) continues to evolve, type 2 diabetes mellitus (T2DM) is a well-established marker of poor clinical prognosis after PCI, which is mainly attributed to the rapid progression of atherosclerosis requiring recurrent revascularizations. Hence, the use of bioresorbable materials could provide some solution to this problem. Material and Methods. The study was divided into two arms. For the first one, we qualified 169 patients with NSTE-ACS treated with PCI who received the drug-eluting stent (DES) coated with a biodegradable polymer Ultimaster (Terumo, Tokyo, Japan). The second arm was composed of 193 patients with ACS who underwent PCI with a magnesium bioresorbable scaffold Magmaris (Biotronik, Berlin, Germany). Both arms were divided into two subsequent groups: the T2DM (59 and 72) and the non-DM (110 and 121, respectively). The primary outcomes were cardiovascular death, myocardial infarction, and in-stent thrombosis. The main secondary outcomes included target lesion failure (TLF) and were recorded at a 1-year-follow-up. RESULTS: There were no significant differences between the diabetic and nondiabetic populations in primary endpoints or main secondary endpoints (TLF, scaffold restenosis, death from any reason, and other cardiovascular events) either in the Ultimaster or Magmaris group. At a 1-year-follow-up, the primary endpoint in the DM t.2 population was recorded in 2.7% Ultimaster vs. 5.1% Magmaris, respectively. At the same time, the TLF occurred in the diabetic group in 4.1% Magmaris and 3.3% in the Ultimaster arm, respectively. CONCLUSION: Both, Ultimaster and Magmaris revealed relative safety and efficiency at a one-year follow-up in the diabetic population in ACS settings. The observed rates of TLF were low, which combined with a lack of in-stent thrombosis suggests that both investigated devices might be an interesting therapeutic option for diabetics with ACS. Nevertheless, further large randomized clinical trials are needed to confirm fully our results.

The impact of left lower paratracheal (4L) lymph node dissection on survival in patients with surgically treated left-sided NSCLC.

OBJECTIVES: We aimed to investigate the clinical significance of left lower paratracheal nodes (#4L) and their impact on survival in patients with left-sided lung cancer. METHODS: This was a retrospective analysis of prospective data. The study included 5369 patients who underwent surgery between 2005 and 2015. Six hundred fifty-nine patients underwent #4L dissection (4LND+), and 4710 did not (4LND-). Propensity score matching was used to minimize analytic error (659 vs 659). RESULTS: The percentage of #4L metastasis increased with tumour size. Between pT2a and pT2b, it nearly doubled from 8% to 14%. The mean percentage of #4L metastasis in the pN2 group was 46, which was higher in left upper lobectomy compared to left lower lobectomy (63% vs 43%, respectively, P < 0.001). In univariable analysis, no differences in 5-year survival were observed between 4LND+ and 4LND- (48% vs 50%, respectively, P = 0.65). However, we detected a significant difference among non-metastatic 4LND+, 4LND- and metastatic 4LND+ (P < 0.0001). After propensity score matching, there were no significant differences in survival among the pN2 subgroups (pN2a1, pN2a2, pN2b1, pN2b2). Multivariable analysis after propensity score matching for each pN2 subgroup did not confirm the effect of #4L metastasis as an independent prognostic factor. CONCLUSIONS: Despite #4L nodes not being an independent prognostic factor in lung cancer, the percentage of nodal metastases notably increases above pT2a grade and is comparable to the percentage of #5 and #7 metastasis. Therefore, lymphadenectomy in advanced stages of cancer could benefit from resections of the #4L nodes.

Merkel Cell Carcinoma of Unknown Primary: Immunohistochemical and Molecular Analyses Reveal Distinct UV-Signature/MCPyV-Negative and High Immunogenicity/MCPyV-Positive Profiles.

BACKGROUND: Merkel cell carcinomas of unknown primary (MCC-UPs) are defined as deep-seated tumors without an associated cutaneous tumor. Although the distinction has important clinical implications, it remains unclear whether these tumors represent primary tumors of lymph nodes or metastatic cutaneous primaries. METHODS: We compared the immunohistochemical profiles of four groups of MCCs (Merkel cell polyomavirus (MCPyV)-positive UP, MCPyV-negative UP, MCPyV-positive known primary (KP), and MCPyV-negative KP) using B-cell and pre-B-cell markers, cell cycle regulating proteins, follicular stem cell markers, and immune markers, and performed next generation and Sanger sequencing. RESULTS: Virus-positive and virus-negative MCC-UPs exhibited an immunoprofile similar to virus-positive and virus-negative primary cutaneous MCCs, respectively. MCC-UP tumors (both virus-positive and -negative) were immunogenic with similar or even higher tumoral PD-L1 expression and intratumoral CD8 and FoxP3 infiltrates in comparison to MCPyV-positive cutaneous tumors. In addition, similar to primary cutaneous MCCs, MCPyV-negative MCC-UPs exhibited UV signatures and frequent high tumor mutational burdens, whereas few molecular alterations were noted in MCPyV-positive MCC-UPs. CONCLUSIONS: Our results showed distinct UV-signatures in MCPyV-negative tumors and high immunogenicity in MCPyV-positive tumors. Although additional studies are warranted for the MCPyV-positive cases, our findings are supportive of a cutaneous metastatic origin for MCPyV-negative MCC-UP tumors.

The influence of the number of lymph nodes removed on the accuracy of a newly proposed N descriptor classification in patients with surgically-treated lung cancer.

INTRODUCTION: The International Association for the Study of Lung Cancer has proposed a new classification of N descriptor based on the number of metastatic lymph nodes (LNs) stations, including skip metastasis. The aim of the study was to determine the effect of removed LNs on the adequacy of this new classification. MATERIALS AND METHODS: The material was collected retrospectively based on the database of the Polish Lung Cancer Group, including information on 8016 patients with non-small cell lung cancer operated in 23 thoracic surgery centers in Poland. The material covered the period from January 2005 to September 2015. We divided patients into two groups: ≤6LNs and >6LNs removed. RESULTS: In the whole group, an average of 13.4 nodes and 4.54 nodal stations were removed. 5-year survivals in the >6LNs group vs ≤ 6LNs group were: 62.3% and 55.1% (N0), 44.5% and 35.9% (N1a), 34.1% and 31,7% (N1b), 37.3% and 26.3% (N2a1), 32.4% and 26.7% (N2a2), 29.4% and 29.2% (N2b1), and 22.0% and 23.0% (N2b2), respectively. Comparing these groups, we detected significant differences at N0 (p < 0.001) and N2a1 (p = 0.022). In the ≤6LNs group, the survival curves for N2a1, N2a2, N2b1, and N2b2 overlapped (p > 0.05). In the >6LNs group, the survival curves were significantly different between grades, with survival for N2a1 better than N1b (p = 0.232). CONCLUSION: The proposed classification N descriptor is potentially better at differentiating patients into different stages. The accuracy of the classification depends on the number of lymph nodes removed. Therefore, the extent of lymphadenectomy has a significant impact on the staging of surgically-treated lung cancer.

The influence of a swab type on the results of point-of-care tests.

Most point-of-care tests (POCT) use swabs for sampling and/or for applying a sample on the test. A variety of swabs differing in tip materials is commercially available. Different tip materials have different chemical and physical characteristics which might influence the specimen collection and release. We investigated properties of various types of swabs used in clinical diagnostics with focusing on two kinds of analytes, DNA and proteins, which are most often used targets in POCT. As the model samples we used diphtheria toxoid NIBSC 69/017 for investigating recovery of protein analytes such as antigens and bacterial strains of Escherichia coli ATCC 25922, diphtheria toxin-producing Corynebacterium diphtheriae NCTC 10648, and the clinical isolate nontoxigenic C. diphtheriae 5820/15 for investigating the recovery of nucleic acids. We investigated four types of swabs most commonly used in clinical diagnostics in terms of absorption capacity and efficiency of release of nucleic acids and proteins. Volume uptake was measured in milligrams. For DNA release various washing out buffers were used and the amount of released DNA was measured spectrophotometrically. The amount of protein released from the swabs were examined using the Lowry assay. We observed statistically significant differences (p < 0.05) in the mean weights of absorbed liquid, in the DNA recovery and protein recovery by the four variety of swab examined. However, the efficiency of DNA and protein release was not correlated to the absorbed volume of a sample, but rather to the properties of swabs. The swab composition and structure can have a significant impact on the collection and release efficiency of a sample. Therefore, validation of POCT in relation to the used swabs for sampling is really important. The use of inappropriate swabs could lead to false negative or misleading analysis results.

Physical and chemical changes in Alhydrogel™ damaged by freezing.

Accidental freezing of aluminum-based vaccines occurs during their storage and transportation, in both developed and developing countries. Freezing damages the freeze-sensitive aluminum adjuvanted vaccines, through separation of lattice between aluminum adjuvant and antigen, leading to formation of aluminum aggregates, and loss of potency. In this study, we examined Alhydrogel™ ([AlO(OH)]xnH2O, aluminum hydroxide, hydrated for adsorption) stored under recommended conditions, and exposed to freezing temperature until solid-frozen. The main purpose of our research was to determine the destruction areas of the solid-frozen Alhydrogel™ using selected methods of scanning electron microscopy, energy dispersive X-ray spectroscopy, Raman spectroscopy, Fourier-transform infrared spectroscopy and transmission electron microscopy working in diffraction mode. The Zeta potential evaluation, measurements of albumin adsorption power, thermogravimetric analysis and estimation of the mass loss after drying indicated significant structural (physical) and chemical differences between the freeze-damaged and non-frozen vaccine adjuvant. The presented results are important to better understand the type and nature of damages occurring in freeze-damaged aluminum-based vaccines. These results can be used in future studies to improve the temperature stability of aluminum adjuvanted vaccines.

Formaldehyde passive sampler using an optical chemical sensor: how to limit the humidity interference.

The behaviour of a new formaldehyde diffusive sampler using an optical chemical sensor with respect to high humidity conditions is examined in controlled atmospheres. Five prototypes of the radial diffusion sampler having the same chemical sensor and different designs were tested. In addition, a set of experiments were performed on the chemical sensor to characterise its efficiency of trapping water vapour in the absence and in the presence of the reactants, Fluoral-P and formaldehyde. Differences in humidity interference between the five diffusive sampler prototypes were studied and discussed. From all the results obtained, it was shown that the prototype LDE1.4 combining a small diffusion slot, a reduced internal volume and a sensor shifted upwards from the diffusion slot provided formaldehyde measurements least affected by humidity up to 80% RH at 20 °C. This new type of diffusive sampler with on-site direct reading is intended to ultimately replace conventional passive samplers with DNPH requiring offset laboratory analyses.