Genetic Polymorphism of the Angiotensin-Converting Enzyme in Bronchial Asthma

Background: Bronchial asthma (BA) is among the most prevalent chronic inflammatory disorders of the lung airways, and it has become clear that a combination of genetic predisposition and environmental factors plays a critical role in its pathogenesis. Objective: The correlation of the angiotensin-converting enzyme (ACE) insertion/deletion polymorphism and other factors with risk for bronchial asthma development was assessed. Materials and Methods: Online literature search was conducted to identify the most relevant studies. Results and Discussion: The ACE insertion/deletion (I/D) gene polymorphism, correlating with cellular and circulating ACE concentration, may play a critical role in BA pathogenesis and has been a focus of numerous epidemiologic studies; however, the results are currently inconclusive. The contradictions in the literature between research groups on the role of ACE alleles and genotypes can be explained by genetic variation and multifactorial causes of BA. Conclusion: This literature review demonstrates that the ACE I/D polymorphism might be related to the risk of bronchial asthma and can become a useful tool in designing effective treatment approaches. Bangladesh Journal of Medical Science Vol. 21 No. 03 July’22 Page: 492-501

COVID-19-associated acute respiratory distress syndrome versus classical acute respiratory distress syndrome (a narrative review)

Coronavirus disease 2019 (COVID-19), caused by the novel coronavirus, Severe Acute Respiratory Syndrome-Coronavirus-2 (SARS-CoV-2), led to the ongoing global public health crisis. Existing clinical data suggest that COVID-19 patients with acute respiratory distress syndrome (ARDS) have worse outcomes and increased risk of intensive care unit (ICU) admission. The rapid increase in the numbers of patients requiring ICU care may imply a sudden and major challenge for affected health care systems. In this narrative review, we aim to summarize current knowledge of pathophysiology, clinical and morphological characteristics of COVID-19-associated ARDS and ARDS caused by other factors (classical ARDS) as defined by Berlin criteria, and therefore to elucidate the differences, which can affect clinical management of COVID-19-associated ARDS. Fully understanding the characteristics of COVID-19-associated ARDS will help identify its early progression and tailor the treatment, leading to improved prognosis in severe cases and reduced mortality. The notable mechanisms of COVID-19-associated ARDS include severe pulmonary infiltration/edema and inflammation, leading to impaired alveolar homeostasis, alteration of pulmonary physiology resulting in pulmonary fibrosis, endothelial inflammation and vascular thrombosis. Despite some distinct differences between COVID-19-associated ARDS and classical ARDS as defined by Berlin criteria, general treatment principles, such as lung-protective ventilation and rehabilitation concepts should be applied whenever possible. At the same time, ventilatory settings for COVID-19-associated ARDS require to be adapted in individual cases, depending on respiratory mechanics, recruitability and presentation timing.

The association of angiotensin-converting enzyme gene insertion/deletion polymorphism with bronchial asthma

Bronchial asthma (BA) is among the most prevalent chronic inflammatory disorders of the lung airways, and it has become clear that a mixture of genetic predisposition and environmental factors plays a critical role in its pathogenesis. The aim of presented review is to analyze the published data on the possible role of ACE gene polymorphism in BA development. The article is based on available literature found in Pubmed, Elsevier, Scopus, and Google scholar databases. We have found that ACE I/D polymorphism may contribute to an important molecular mechanisms of BA development (specially D/D genotype), and may become a useful tool in risk assessment and in designing effective treatment approaches. The difference in the literature on the role of ACE alleles and genotypes can be explained by minor influence of the investigated genetic component and contributions of other genetic variations, as well as other environmental factors, considering multifactorial causes of BA.

Chitosan self-assembled polymeric nanoparticles for percutaneous delivery of betamethasone in contact dermatitis

OBJECTIVE

The study was performed with an aim to investigate the efficiency of two treatment options in experimental nickel-induced contact dermatitis (CT), with either betamethasone or chitosan cross-linked nano-encapsulated betamethasone lanoline solutions (nano-betamethasone).

METHODS

Male Wistar rats were used. The differences were compared based on lesion visual appearance, skinfold thickness, white blood cell count (WBC), erythrocyte sedimentation rate (ESR), blood serum prooxidant-antioxidant balance (thiobarbituric acid reactive substances, TBARS; supersoxide dismutase, SOD; catalase, KAT), blood cytokine profile (TNF-α, IL-1β, IL-10, and IL-4), and histological examination of affected skin.

RESULTS

All animals treated with nickel sulfate developed CT and systemic inflammatory response on day 12, which only slightly lessened, if left untreated, on day 20. The therapeutic effectiveness of nano-betamethasone was significantly far superior (p < 0.01) compared to betamethasone. Specifically, the visual appearance of lesion severity of betamethasone vs. nano-betamethasone ± SD was 1.82 ± 0.18 vs. 1.17 ± 0.24 points, skinfold thickness-2.68 ± 0.12 vs. 2.12 ± 0.10 mm, ESR-6.38 ± 0.27 vs. 5.12 ± 0.20 mm/h, WBC-8.47 ± 0.28 vs. 7.17 ± 0.24 10⁹/L, TBARS-1.09 ± 0.04 vs. 0.94 ± 0.02 µmol/L, SOD-3.38 ± 0.26 vs. 4.12 ± 0.18 r.u./L, KAT-11.54 ± 0.14 vs. 10.02 ± 0.19 mkatal/L, respectively. The nano-betamethasone formulation was also more effective (p < 0.01) in increasing anti-inflammatory cytokines level, IL-10 (8.96 ± 0.32 vs. 7.54 ± 0.52 pg/mL) and IL-4 (13.16 ± 0.45 vs. 11.43 ± 0.58 pg/mL); and decreasing in pro-inflammatory TNF-α (20.94 ± 2.30 vs. 26.98 ± 1.16 pg/mL) and IL-1β (19.35 ± 1.28 vs. 24.77 ± 1.75 pg/mL), respectively. These findings were also supported with histological examination.

CONCLUSIONS

Nano-betamethasone may be considered as a more successful transcutaneous therapy for managing contact dermatitis compared to ointments consisting of betamethasone in traditional form.

Transfer efficacy of Escherichia coli O157:H7 between surfaces of green mature tomatoes and common food processing materials

The objectives of this study were: a) to evaluate E. coli O157:H7 survival on green mature tomatoes and squares of common food processing materials – stainless steel, plastic (HDPE), and vinyl conveyor belt (PVC) – post-drying, stored at 25 ºC in the humidified environment for four days; b) to determine pathogen transfer rates (wet, 90 minutes, or 24-hours drying post-inoculation), from inoculated tomato surfaces to uninoculated steel, plastic, and vinyl conveyor belt squares and conversely. It was shown that E. coli O157:H7 did not survive well on the surface of tomatoes, resulting in a decline from 5.3 log10 CFU.mL-1 90 minutes post-drying to 1.4 log10 CFU.mL-1 on day 4. Similarly, the pathogen did not survive well on the surface of food processing squares, with numbers declining over 4 days from 4.04, 4.44, and 4.19 CFU.mL-1 of rinsate 90 minutes squares post-drying to 0.72, 0.50, 0.83  log10 CFU.mL-1, which is close to the detection limit, for the steel, vinyl belt, and plastic, respectively. Successful cross-contamination between tomatoes and food processing surfaces was achieved during wet transfer; while transfer after 90 minutes inoculum post-drying and 24 hours were less successful. This can be explained by both lack of liquid media with suspended bacteria for transfer and fast pathogen die-off after desiccation. Dry transfers, as shown by the percentage of “positive” for pathogen presence tomatoes and squares, as well as bacterial counts, were more successful from tomatoes to squares, but not conversely. Special concern raised vinyl conveyor belt, where the surface picked up the most pathogen cells from the surface of tomatoes, resulting in 100% positive during 90 minute-dry transfers, followed by plastic (66.7% positive) and steel (55.6% positive). To summarize, we presented data on the possibility of cross-contamination between mature green tomatoes and common food processing surfaces, which may be interesting for the processors for risk evaluation.

Dietary supplementation with magnesium citrate may improve pancreatic metabolic indices in an alloxan-induced diabetes rat model

The purpose of the current study was to evaluate the protective properties of dietary magnesium supplementation on pancreatic tissue of rats with alloxan-induced diabetes mellitus. Twenty-five male Wistar rats were split into five groups (control, diabetes, diabetes with 100 mg Mg daily, diabetes with 250 mg Mg daily, diabetes with 500 mg Mg daily) with feeding supplementation starting on day 1, diabetes induction on day 21, and animal sacrifice on day 30. Fasting glucose in blood serum was measured on days 21, 25, 27, and day 30. Glucose metabolism enzymes, namely, lactate dehydrogenase and glucose-6-phosphate dehydrogenase, were measured in pancreatic tissue upon the sacrifice, as well as lipid peroxidation, antioxidant system protective enzymes (catalase and superoxide dismutase), and glutathione system components (glutathione reductase, glutathione peroxidase, and glutathione reduced). Pearson correlation coefficients showed strong negative correlation between serum glucose (control and diabetic animals) and glucose metabolism enzymes, catalase, superoxide dismutase, glutathione peroxidase in pancreatic tissue (r >-0.9, p <0.05), moderate negative correlation with reduced glutathione (r = -0.79, p <0.05), moderate positive correlation with lipid peroxidation index (r = +0.67, p <0.05), weak correlation with glutathione reductase (r = -0.57, p <0.05). Magnesium supplementation slowed down diabetes onset considering fasting glucose levels in rats (p <0.05), as well as partially restored investigated dehydrogenase levels in the pancreas of rats comparing to diabetes group (p <0.05). The lipid peroxidation index varied between treatments showing the dose-dependent influence of Mg2+. Magnesium supplementation partially restored catalase and superoxide dismutase activities in pancreatic tissue, as well as glutathione peroxidase and reduced glutathione levels (p <0.05), while glutathione reductase levels remained unaffected (p >0.05). The obtained results suggested a model, where magnesium ions may have a possible protective effect on pancreatic tissue against the negative influence of alloxan inside β cells of the pancreas.

Influence of suspension liquid total solids on E. coli O157:H7 survival and transfer efficacy between green tomatoes and cardboard

The objectives of this study were: a) to determine E. coli O157:H7 survival on tomatoes and cardboard squares post-drying, stored at 25 ºC in humidified environment for four days, in buffered peptone water (BPW), and 0.1% diluted peptone (DP); b) to determine pathogen transfer rates (0, 1.5, or 24-hours drying post-inoculation), from inoculated tomato surfaces to uninoculated cardboard squares and conversely; and c) to evaluate SystemSure Plus ATP luminometer for recognizing contamination on visibly soiled (BPW) or visible clean (DP) cardboard. In tomato inoculation studies, E. coli O157:H7 survived better on the fruit when the inoculum was prepared using DP as compared to BPW. The 1.5-hours post drying counts of 5.34 and 5.76 log10 CFU.mL-1 in the rinsate substantially declined to 1.45 and 1.17 log10 CFU.mL-1 on day four, for DP and BPW, respectively. In cardboard inoculation studies, E. coli O157:H7 persisted for four days, with 1.5-hours post-drying counts and day four counts of 4.53 (DP) and 2.55 log10 CFU.mL-1 (BPW), contrary to 3.81 (DP) and 1.92 log10 CFU.mL-1 (BPW). Under the first impression, the slower die-off of E. coli O157:H7 on cardboard questions the possibility of reusing cardboard boxes due to the potential for cross-contamination. In wet transfer (0 hour drying) trials, both tomato-to-cardboard and cardboard-to-tomato yielded 100% positive transfers irrespective of diluent type. Dry transfer (1.5-hours drying interval post inoculation) from tomato-to-cardboard were 100% positive, but no positives were noted when inoculated, dried cardboard was contacted to tomatoes, irrespective of diluent. Results of transfers with BPW as the diluent showed 100% positive transfer from 24-hours dry tomatoes-to-cardboard, as inoculation spots on the tomatoes remained moist due to hygroscopic nature of solutes in BPW. Conversely, only a 40% positive transfer rate was observed under the same conditions with DP as diluent. No positive transfers were recorded from 24-hours dry cardboard-to-tomatoes, irrespective of diluent type. Though E. coli O157:H7 survived better on the surface of cardboard compared to the surface of tomatoes on day four, the dry transfers were more efficient from tomatoes-to-cardboard than conversely, possibly due to smooth and hydrophobic properties of the tomato, and rough and porous surface of the cardboard. ATP luciferase UltrasnapTM swab test showed 9/9 “pass” results for sterile liquid DP and BPW, while 9/9 “fail” results were observed with liquid peptone and BPW contaminated at ca. 9.0 log10 CFU.mL-1E. coli O157:H7. Cardboard squares treated and dried, with sterile DP, showed 8/9 “pass” ATP luciferase results, and 1/9 “warning”, while cardboard squares with contaminated DP showed 9/9 “fail” result. Cardboard squares treated and dried, with sterile BPW, showed 7/9 “pass” ATP luciferase results, and 2/9 “warning”, while cardboard squares with contaminated BPW showed 9/9 “fail” result. Luminometer can simplify detection of microbial load, as well as organic residues, helping to check cardboard boxes for cleanness.

Microbiological comparison of visibly dirty and visibly clean mature green tomatoes before and after treatments with deionized water or chlorine in model overhead spray brush roller system

The purpose of the current study was to compare natural microflora counts of mature green tomatoes as influenced by visual cleanness, and investigate ability of chlorine sanitizer to reduce different groups of natural microflora on the surface of tomatoes using overhead spray brush roller system. We hypothesized that natural microflora might not be equally affected, with vegetative Gram negative bacteria being more sensitive and soil-related Gram positive sporoforming bacilli and molds more resistant. Microflora from untreated visibly clean and visibly dirty tomatoes, as well as from visibly clean tomatoes after 30 seconds deionized water or 100 ppm chlorine treatments, was recovered and spread plated on Tryptic Soy agar, MacConkey agar, and acidified Potato Dextrose agar. Microflora from untreated and chlorine-treated tomatoes was non-specifically enriched and plated on agar with chlorine paper disc diffusion assay applied to check for inhibition zone differences. Interestingly, there was no significant difference in plate counts between visibly clean and dirty tomatoes (p >0.05). Chlorine was more effective than water alone to reduce microbial counts on tomatoes for all microbiological media tested. Based on similar relative reductions of microorganisms in each group, it was concluded that chlorine may have no preferential kill for investigated groups of microorganisms. High counts remaining after treatment with chlorine solution suggested possibility of resistant microbial biofilm formation on the surface of tomatoes.

Influence of temperature, humidity, and diluent type on survival of Salmonella spp. on the surface of raw tomatoes

Tomatoes are an important commodity, placing fourth among most popular vegetables in the U.S. However, fresh tomatoes lack a final pathogen elimination step and have been implicated in Salmonella-related outbreaks. The purpose of the study was to evaluate survival of Salmonella post-drying in three diluents on the surface of green mature tomatoes at 12 °C or 25 °C. Additionally, low and high air relative humidity influence was evaluated at 25 °C on pathogen survival. A five Salmonella rifampin-resistant strain cocktail was double-washed in buffered peptone water (BPW) and resuspended in 0.1% peptone, BPW, or fresh tomato serum. Inoculum (0.1 mL) was allowed to dry on the surface of tomatoes. For study I, tomatoes were placed in 12 °C and 25 °C incubators with no humidity control and sampled on days 0, 1, 3, and 5. For study II, tomatoes were sampled on days 0, 1 (biosafety hood storage) and on day 5 after storage in two 25 oC incubators (low and high relative humidity). Salmonella was recovered from tomatoes (20 mL BPW) and plated (TSA-rif80, 37 °C, 48 hours). Post-drying Salmonella counts (ca. 4.5 – 5.0 log10 CFU.mL-1) remained at 4.03 and 4.40 log10 CFU.mL-1 in serum after 5 days of storage at 12 °C and 25 °C, respectively. Conversely, corresponding counts in BPW and peptone were lower at ca. 1.4 to 1.8 and 2.2 to 2.8 log units at 12 °C and 25 °C, respectively. At low humidity, post-drying Salmonella counts showed highest decline for peptone (final 1.98 log10 CFU.mL-1) compared to BPW (3.79 log10 CFU.mL-1) and tomato serum (4.75 log10 CFU.mL-1) on day 5. Counts declined rapidly to 0.03, 0.56, and 0.44 log10 CFU.mL-1 for peptone, BPW, and tomato serum, respectively, at high humidity on day 5. To summarize, it was shown that increased solutes have protective effect on Salmonella in desiccated conditions, while high humidity storage causes accelerated death of stationary culture within five days storage period.

Long-Term Depuration of Crassostrea virginica Oysters at Different Salinities and Temperatures Changes Vibrio vulnificus Counts and Microbiological Profile

Previous short-duration depuration studies with the eastern oyster ( Crassostrea virginica) demonstrated difficulty in achieving significant naturally incurred Vibrio vulnificus population count reductions. The present study used long-duration depuration (14 days) at controlled temperatures (10 or 22°C) and salinities (12, 16, or 20 mg/g). All depuration temperature-salinity combinations significantly reduced V. vulnificus counts, with greatest reductions seen in 12 mg/g, 10°C seawater (2.7-log CFU/g reduction) and in 20 mg/g, 22°C seawater (2.8-log reduction). Mesophilic vibrios dominated the overall microflora of freshly harvested oysters, whereas refrigerated storage selected for psychrotrophic bacteria ( Pseudomonas spp., Aeromonas spp., Shewanella spp., Psychrobacter spp.) as well as did depuration at 10°C ( Pseudoalteromonas spp., Shewanella spp., Vibrio spp.). Depuration at 22°C retained dominance of mesophilic vibrios, including pathogenic species, followed by Shewanella spp., Pseudoalteromonas spp., and Photobacterium spp. Although aerobic plate counts were lower in 22°C depurated oysters (5.0 log versus 6.0 log) compared with 10°C, depuration at 10°C offered greater V. vulnificus population reductions than depuration at 22°C. This advantage was only seen at 12 mg/g salinity, with no impact at 16 and 20 mg/g salinities. No depuration treatment reduced V. vulnificus counts to nondetectable levels. Use of prolonged depuration may be a helpful intervention to control V. vulnificus populations in oysters.

Survival of Escherichia coli O157:H7 and Salmonella on Bruised and Unbruised Tomatoes from Three Ripeness Stages at Two Temperatures

Tomatoes are one of the major fresh produce commodities consumed in the United States. Harvesting tomato fruit at a later stage of development can enhance consumer acceptance but can also increase damage due to bruising. Bruising can affect the quality of whole tomatoes by causing an unacceptable appearance and accelerating decay. Bruising may also facilitate bacterial attachment to the fruit surface and support growth of pathogens. This study evaluated the survival and/or proliferation of Escherichia coli O157:H7 and Salmonella on the surface of artificially bruised and unbruised tomatoes at three ripeness stages (breaker, pink, and red) and two storage temperatures (10 and 20°C). A total of 1,440 tomatoes, 720 for each organism, were analyzed. Both E. coli O157:H7 and Salmonella counts declined significantly ( P < 0.05) on the bruised and unbruised tomatoes over the 7-day storage period, by approximately 2.5 and 2.0 log, respectively. E. coli O157:H7 was not detected on pink tomatoes on day 7, whereas Salmonella persisted on the tomato surfaces throughout the 7-day study at all ripeness stages. Bruising had no significant effect ( P > 0.05) on the survival of E. coli O157:H7 (CFU per tomato) compared with the unbruised tomatoes, in most cases. Tomatoes from the red ripeness stage showed a significant effect ( P < 0.05) of bruising on Salmonella survival at both 10 and 20°C. Similar to the colony count results, the frequency (presence or absence) of inoculated tomatoes with detectable levels of inoculated bacteria decreased significantly ( P < 0.05) over time. At the lower temperature, E. coli O157:H7 was recovered from significantly higher ( P < 0.05) numbers of breaker and pink tomatoes, whereas there was no effect of temperature on the overall survival of E. coli O157:H7 on red tomatoes. Results from this study are essential for understanding the effects of bruising on produce safety and for producers and packers to develop mitigation strategies to control pathogenic and spoilage organisms.

Mechanism of synergistic inhibition of Listeria monocytogenes growth by lactic acid, monolaurin, and nisin

The combined lactic acid, monolaurin, and nisin effects on time-to-detection (optical density at 600 nm) extension were greater (P < 0.05) than any single or paired combination effect, which demonstrates a synergistic interaction among the antimicrobials. Monolaurin exposure caused C12:0 cell membrane incorporation. Lactic acid caused increased monolaurin C12:0 membrane incorporation, while nisin had no influence. We postulate that lactic acid-enhanced monolaurin C12:0 incorporation into the cell membrane increased membrane fluidity resulting in increased nisin activity.