Evaluation of the microbiological efficacy of cleaning agents for tracheostomy inner cannulas.

PURPOSE: Biofilms are a significant cause of morbidity in patients with indwelling medical devices. Biofilms pose a potential risk with reusable inner cannulas by increasing the risk of infections. Effective decontamination is thus vital in decreasing bioburden. The current guidelines for cleaning inner cannulas are varied, with multiple techniques being recommended, which are not supported by strong evidence. This randomized, controlled, cross-over study attempted to enumerate the bacterial count of inner cannulas used in tracheostomy patients (n = 60) pre-and post-decontamination with detergent (A) or sterile water (B). MATERIALS AND METHODS: The patients were randomly allocated to sequence A > B or B > A in 1:1 fashion. The saline flushing of the inner cannulas was plated on trypticase soy agar with 5 % sheep blood to enumerate the bacterial count. RESULTS: The mean ratio [Log (CFU)post/Log (CFU)pre]A/[Log (CFU)post/Log (CFU)pre]B based on 53 samples was 0.918 ± 0.470, two-sided 90 % confidence interval (CI) 0.812, 1.024. The equivalence criterion was met as the mean ratio after cleaning fell within the equivalence region of 0.8 and 1.25. CONCLUSION: This study demonstrated the microbiological efficacy of both detergent and sterile water in the decontamination of inner cannulas, and that sterile water was not less effective than detergent in reducing the bacterial load for safe re-use of inner cannulas. This has the potential to promote cost savings for patients with tracheostomy, both in the hospital and the community. The study findings may also be relevant in formulating tracheostomy care policies.

Hyperthermic Intraperitoneal Chemotherapy (HIPEC): An Overview of the Molecular and Cellular Mechanisms of Actions and Effects on Epithelial Ovarian Cancers.

Most patients with epithelial ovarian cancers (EOCs) are at advanced stages (stage III-IV), for which the recurrence rate is high and the 5-year survival rate is low. The most effective treatment for advanced diseases involves a debulking surgery followed by adjuvant intravenous chemotherapy with carboplatin and paclitaxel. Nevertheless, systemic treatment with intravenous chemotherapeutic agents for peritoneal metastasis appears to be less effective due to the poor blood supply to the peritoneal surface with low drug penetration into tumor nodules. Based on this reason, hyperthermic intraperitoneal chemotherapy (HIPEC) emerges as a new therapeutic alternative. By convection and diffusion, the hyperthermic chemotherapeutic agents can directly contact intraperitoneal tumors and produce cytotoxicity. In a two-compartment model, the peritoneal-plasma barrier blocks the leakage of chemotherapeutic agents from peritoneal cavity and tumor tissues to local vessels, thus maintaining a higher concentration of chemotherapeutic agents within the tumor tissues to facilitate tumor apoptosis and a lower concentration of chemotherapeutic agents within the local vessels to decrease systemic toxicity. In this review, we discuss the molecular and cellular mechanisms of HIPEC actions and the effects on EOCs, including the progression-free survival (PFS), disease-free survival (DFS) and overall survival (OS). For primary advanced ovarian cancers, more studies are agreeing that patients undergoing HIPEC have better surgical and clinical (PFS; OS) outcomes than those not, although one study reported no differences in the PFS and OS. For recurrent ovarian cancers, studies have revealed better DFS and OS in patients undergoing HIPEC than those in patients not undergoing HIPEC, although one study reported no differences in the PFS. HIPEC appears comparable to traditional intravenous chemotherapy in treating advanced EOCs. Overall, HIPEC has demonstrated some therapeutic benefits in many randomized phase III trials when combined with the standard cytoreductive surgeries for advanced EOCs. Nevertheless, many unknown aspects of HIPEC, including detailed mechanisms of actions, along with the effectiveness and safety for the treatment of EOCs, warrant further investigation.

NLRP1, PTPN22 and PADI4 gene polymorphisms and rheumatoid arthritis in ACPA-positive Singaporean Chinese.

Studies have shown that the genetic risk factors for rheumatoid arthritis (RA) differ substantially between Asian and Caucasian populations. Even among Asian populations, the genetic contributions of NLRP1, PTPN22 and PADI4 have been controversial. Consequently, we sought to address these separate findings and determine whether any of these proposed risk variants are associated with RA susceptibility, onset, DAS activity and erosion in a Singaporean Chinese cohort. We genotyped five SNPs within NLRP1 (rs878329 and rs6502867), PTPN22 (rs2488457 and rs6665194), and PADI4 (rs2240340) in 500 anti-cyclic citrullinated peptide antibody-positive (ACPA) patients with RA and 500 healthy controls using TaqMan assays. The CC genotype of NLRP1 rs878329 and TT genotype of PADI4 rs2240340 were associated with RA susceptibility. The risk association of the T allele of PADI4 rs2240340 with RA was confirmed through a meta-analysis based on previous reports in Asian populations. The GG genotype of PTPN22 rs6665194 (-3508A>G) was associated with significantly reduced risk of RA. No significant association was found for NLRP1 rs6502867 T/C and PTPN22 rs2488457 G/C polymorphisms. None of the five SNPs was associated with RA's clinical features. This work supports the association of the T allele of PADI4 rs2240340 with RA in Asians. The roles of NLRP1 rs878329 G/C and PTPN22 rs6665194 A/G polymorphisms were demonstrated for the first time. We also propose rs6665194 to be a promising candidate for RA risk evaluation between ethnicities.

RNA-directed DNA methylation regulates parental genomic imprinting at several loci in Arabidopsis.

In mammals and plants, parental genomic imprinting restricts the expression of specific loci to one parental allele. Imprinting in mammals relies on sex-dependent de novo deposition of DNA methylation during gametogenesis but a comparable mechanism was not shown in plants. Rather, paternal silencing by the maintenance DNA methyltransferase 1 (MET1) and maternal activation by the DNA demethylase DEMETER (DME) cause maternal expression. However, genome-wide studies suggested other DNA methylation-dependent imprinting mechanisms. Here, we show that de novo RNA-directed DNA methylation (RdDM) regulates imprinting at specific loci expressed in endosperm. RdDM in somatic tissues is required to silence expression of the paternal allele. By contrast, the repression of RdDM in female gametes participates with or without DME requirement in the activation of the maternal allele. The contrasted activity of DNA methylation between male and female gametes appears sufficient to prime imprinted maternal expression. After fertilization, MET1 maintains differential expression between the parental alleles. RdDM depends on small interfering RNAs (siRNAs). The involvement of RdDM in imprinting supports the idea that sources of siRNAs such as transposons and de novo DNA methylation were recruited in a convergent manner in plants and mammals in the evolutionary process leading to selection of imprinted loci.

Cellular and molecular overview of gestational diabetes mellitus: Is it predictable and preventable?

BACKGROUND: In contrast to overt diabetes mellitus (DM), gestational DM (GDM) is defined as impaired glucose tolerance induced by pregnancy, which may arise from exaggerated physiologic changes in glucose metabolism. GDM prevalence is reported to be as high as 20% among pregnancies depending on the screening method, gestational age, and the population studied. Maternal and fetal effects of uncontrolled GDM include stillbirth, macrosomia, neonatal diabetes, birth trauma, and subsequent postpartum hemorrhage. Therefore, it is essential to find the potential target population and associated predictive and preventive measures for future intensive peripartum care. AIM: To review studies that explored the cellular and molecular mechanisms of GDM as well as predictive measures and prevention strategies. METHODS: The search was performed in the Medline and PubMed databases using the terms "gestational diabetes mellitus," "overt diabetes mellitus," and "insulin resistance." In the literature, only full-text articles were considered for inclusion (237 articles). Furthermore, articles published before 1997 and duplicate articles were excluded. After a final review by two experts, all studies (1997-2023) included in the review met the search terms and search strategy (identification from the database, screening of the studies, selection of potential articles, and final inclusion). RESULTS: Finally, a total of 79 articles were collected for review. Reported risk factors for GDM included maternal obesity or overweight, pre-existing DM, and polycystic ovary syndrome. The pathophysiology of GDM involves genetic variants responsible for insulin secretion and glycemic control, pancreatic ß cell depletion or dysfunction, aggravated insulin resistance due to failure in the plasma membrane translocation of glucose transporter 4, and the effects of chronic, low-grade inflammation. Currently, many antepartum measurements including adipokines (leptin), body mass ratio (waist circumference and waist-to-hip ratio], and biomarkers (microRNA in extracellular vesicles) have been studied and confirmed to be useful markers for predicting GDM. For preventing GDM, physical activity and dietary approaches are effective interventions to control body weight, improve glycemic control, and reduce insulin resistance. CONCLUSION: This review explored the possible factors that influence GDM and the underlying molecular and cellular mechanisms of GDM and provided predictive measures and prevention strategies based on results of clinical studies.

Development of a rapid multiplex PCR assay for the detection of common pathogens associated with community-acquired pneumonia.

BACKGROUND: Community-acquired pneumonia (CAP) is one of the most common infectious diseases and is a significant cause of mortality and morbidity globally. A microbial cause was not determined in a sizable percentage of patients with CAP; there are increasing data to suggest regional differences in bacterial aetiology. We devised a multiplex real-time PCR assay for detecting four microorganisms (Streptococcus pneumoniae, Haemophilus influenzae, Klebsiella pneumoniae and Burkholderia pseudomallei) of relevance to CAP infections in Asia. METHODS: Analytical validation was accomplished using bacterial isolates (n=10-33 of each target organism for analytical sensitivity and n=117 for analytical sensitivity) and clinical validation using 58 culture-positive respiratory tract specimens. RESULTS: The qPCR assay exhibited 100% analytical sensitivity and analytical specificity, and 100% clinical sensitivity and 94-100% clinical specificity. The limit of detection and efficiency for the multiplex PCR assay were 3-33 CFU/mL and 93-110%, respectively. The results showed that the PCR-based method had higher sensitivity than traditional culture-based methods. The assay also demonstrated an ability to semiquantify bacterial loads. CONCLUSION: We have devised a reliable laboratory-developed multiplex qPCR assay, with a turnaround time of within one working day, for detection of four clinically important CAP-associated microorganisms in Asia. The availability of a test with improved diagnostic capabilities potentially leads to an informed choice of antibiotic usage and appropriate management of the patient to achieve a better treatment outcome and financial savings.

Ovarian Diffuse Large B-cell Lymphoma Initially Suspected Dysgerminoma Managed by Laparoscopic Staging Surgery.

Ovarian diffuse large B-cell lymphoma (DLBCL) is rare. DLBCL is a complex type of lymphoma. The ovarian DLBCL usually harbor a favorable prognosis. We report a case of ovarian DLBCL that presented as an ovarian mass with lower abdominal pain and was managed using laparoscopic staging surgery. A 29-year-old female (gravida 2, para 0, abortion 2) with a history of polycystic ovarian syndrome with irregular medication control visited our clinic due to lower abdominal pain. Transvaginal ultrasound revealed a heterogeneous, septated mass over the left adnexa with a diameter of approximately 6 cm × 8 cm. The tumor marker CA 19-9 was elevated (65.77 IU/mL); CA125 and carcinoembryonic antigen were not elevated. Laparoscopic surgery with left salpingo-oophorectomy was first performed. Frozen section indicated dysgerminoma. Then, we continued staging surgery through bilateral pelvic lymph node dissection, para-aortic lymph node dissection, omentectomy, right ovary and peritoneum biopsy, and washing cytology. Ovarian tumor and para-aortic lymph nodes were positive for lymphoma. The tumor cells were positive staining for CD20, CD5, ki67, BCL-6, and MUM-1, which was associated with DLBCL. The patient was then consulted for oocyte preservation and referred to hematology for further chemotherapy. In conclusion, an ovarian lymphoma is a rare event. The presence of an enlarged ovarian tumor should raise the suspicion of ovarian lymphoma. To differentiate ovarian lymphoma from dysgerminoma, immunohistochemistry is useful. Fertility preservation should be considered before chemotherapy. Ovarian tissue or oocyte preservation or gonadotropin-releasing hormone agonist injection before chemotherapy can be performed for fertility preservation.

Hydrogen-Bonding Interactions in Hybrid Aqueous/Nonaqueous Electrolytes Enable Low-Cost and Long-Lifespan Sodium-Ion Storage.

Although "water-in-salt" electrolytes have opened a new pathway to expand the electrochemical stability window of aqueous electrolytes, the electrode instability and irreversible proton co-insertion caused by aqueous media still hinder the practical application, even when using exotic fluorinated salts. In this study, an accessible hybrid electrolyte class based on common sodium salts is proposed, and crucially an ethanol-rich media is introduced to achieve highly stable Na-ion electrochemistry. Here, ethanol exerts a strong hydrogen-bonding effect on water, simultaneously expanding the electrochemical stability window of the hybridized electrolyte to 2.5 V, restricting degradation activities, reducing transition metal dissolution from the cathode material, and improving electrolyte-electrode wettability. The binary ethanol-water solvent enables the impressive cycling of sodium-ion batteries based on perchlorate, chloride, and acetate electrolyte salts. Notably, a Na0.44MnO2 electrode exhibits both high capacity (81 mAh g-1) and a remarkably long cycle life >1000 cycles at 100 mA g-1 (a capacity decay rate per cycle of 0.024%) in a 1 M sodium acetate system. The Na0.44MnO2/Zn full cells also show excellent cycling stability and rate capability in a wide temperature range. The gained understanding of the hydrogen-bonding interactions in the hybridized electrolyte can provide new battery chemistry guidelines in designing promising candidates for developing low-cost and long-lifespan batteries based on other (Li+, K+, Zn2+, Mg2+, and Al3+) systems.

Comparison of the Biofire FilmArray Respiratory Panel, Seegene AnyplexII RV16, and Argene for the detection of respiratory viruses.

BACKGROUND: Respiratory infections are common reasons for hospital admission, and are associated with enormous economic burden due to significant morbidity and mortality. The wide spectrum of microbial agents underlying the pathology renders the diagnosis of respiratory infections challenging. Molecular diagnostics offer an advantage to the current serological and culture-based methods in terms of sensitivity, coverage, hands-on time, and time to results. OBJECTIVES: This study aimed to compare the clinical performance of three commercial kits for respiratory viral detection. STUDY DESIGN: The performance of FilmArray Respiratory Panel, AnyplexII RV16, and Argene was compared using clinical respiratory samples (n = 224, comprising 189 nasopharyngeal swabs in Universal Transport Medium (UTM) and 35 endotracheal aspirates), based on common overlapping targets across the platforms. Influenza A "equivocal" and "no-subtype" samples by FilmArray were further compared to a laboratory-developed Influenza A/B test. RESULTS AND CONCLUSIONS: The overall performance of all three platforms appeared to be comparable with regards to sensitivities (95.8-97.9%) and specificities (96.1-98.0%), detection of coinfections, and distinguishment of influenza from non-influenza cases. "Equivocal" and "no-subtype" samples by FilmArray mostly represented weak Influenza A by laboratory-developed test. Lower respiratory tract samples had comparable final-run success-rates and discordant-rates as compared to UTM. Coronavirus HKU1, which was not targeted by AnyplexII RV16, were detected as OC43. The expected test volume would be the main determinant for the selection of platform. Among the platforms, the FilmArray is the most automated but is of the lowest-throughput and has the highest reagent cost.

Synthesis and Characterization of Types A and B Gelatin Methacryloyl for Bioink Applications.

Gelatin methacryloyl (GelMA) has been increasingly considered as an important bioink material due to its tailorable mechanical properties, good biocompatibility, and ability to be photopolymerized in situ as well as printability. GelMA can be classified into two types: type A GelMA (a product from acid treatment) and type B GelMA (a product from alkali treatment). In current literature, there is little research on the comparison of type A GelMA and type B GelMA in terms of synthesis, rheological properties, and printability for bioink applications. Here, we report the synthesis, rheological properties, and printability of types A and B GelMA. Types A and B GelMA samples with different degrees of substitution (DS) were prepared in a controllable manner by a time-lapse loading method of methacrylic anhydride (MAA) and different feed ratios of MAA to gelatin. Type B GelMA tended to have a slightly higher DS compared to type A GelMA, especially in a lower feed ratio of MAA to gelatin. All the type A and type B GelMA solutions with different DS exhibited shear thinning behaviours at 37 °C. However, only GelMA with a high DS had an easy-to-extrude feature at room temperature. The cell-laden printed constructs of types A and B GelMA at 20% w/v showed around 75% cell viability.

3D patterned substrates for bioartificial blood vessels - The effect of hydrogels on aligned cells on a biomaterial surface.

The optimal bio-artificial blood vessel construct is one that has a compliant tubular core with circumferentially aligned smooth muscle cells (SMCs). Obtaining this well-aligned pattern of SMCs on a scaffold is highly beneficial as this cellular orientation preserves the SMC contractile phenotype. We used 3D patterning to create channels on a polycaprolactone (PCL) scaffold; SMCs were then found to be aligned within the microchannels. To preserve this alignment, and to provide a protective coating that could further incorporate cells, we evaluated the use of two hydrogels, one based on poly(ethylene glycol) diacrylate (PEGDA) and the other based on gelatin. Hydrogels were either physically coated on the PCL surfaces or covalently linked via suitable surface modification of PCL. For covalent immobilization of PEGDA hydrogel, alkene groups were introduced on PCL, while for gelatin covalent linkage, serum proteins were introduced. It is, however, crucial that the hydrogel coating does not disrupt the cellular patterning and distribution. We show in this work that both the process of coating as well as the nature of the coating are critical to preservation of the aligned SMCs. The covalent coating methods involving the crosslinking of hydrogels with the surface of PCL films promoted hydrogel retention time on the film as compared with physical deposition. Furthermore, subsequent hydrogel degradation is affected by the components of the cell culture medium, hinting at a possible route to in vivo biodegradation. STATEMENT OF SIGNIFICANCE: Surface features control cellular orientation and subsequently influence their functionality, a useful effect for cellularized biomedical devices. Such devices also can benefit from protective and cell friendly hydrogel coatings. However, literature is lacking on the fate of cells that have endured hydrogel coating whilst orientated on a biomaterial surface. In particular, elucidation of the cells ability to remain adherent and orientated post hydrogel addition. Coating requires two procedures that may be deleterious to the orientated cells: the surface pretreatment for gel binding and the hydrogel crosslinking reaction. We compare transglutaminase gelatin crosslinking and UV initiated PEGDA crosslinking, coated onto smooth muscle cells orientated on patterned PCL surfaces. This original study will be of considerable use to the wider biomaterials community.