Preliminary findings of performing aerosol generating procedures using a novel innovative mask in times of COVID-19 pandemic.

This article describes an innovative mask consisting of a newly fabricated 3-ply surgical face mask with a custom made attachment consisting of a plastic dome and a oneway valve port that allows endoscopes to be inserted through it. The mask was tested in-vitro with simulated sneezing using fluorescent dyes and also received positive feedbacks from field tests of 30 masks on real users in different hospitals. This innovative mask is useful in providing extra barrier for endoscopic procedures in ENT and can be used beyond this pandemic in patients with other infectious diseases.

IL-15 super-agonist (ALT-803) enhances natural killer (NK) cell function against ovarian cancer.

OBJECTIVE: Natural killer (NK) cells represent a powerful immunotherapeutic target as they lyse tumors directly, do not require differentiation, and can elicit potent inflammatory responses. The objective of these studies was to use an IL-15 super-agonist complex, ALT-803 (Altor BioScience Corporation), to enhance the function of both normal and ovarian cancer patient derived NK cells by increasing cytotoxicity and cytokine production. METHODS: NK cell function from normal donor peripheral blood mononuclear cells (PBMCs) and ovarian cancer patient ascites was assessed using flow cytometry and chromium release assays ±ALT-803 stimulation. To evaluate the ability of ALT-803 to enhance NK cell function in vivo against ovarian cancer, we used a MA148-luc ovarian cancer NOD scid gamma (NSG) xenogeneic mouse model with transferred human NK cells. RESULTS: ALT-803 potently enhanced functionality of NK cells against all ovarian cancer cell lines with significant increases seen in CD107a, IFNγ and TNFα expression depending on target cell line. Function was also rescued in NK cells derived from ovarian cancer patient ascites. Finally, only animals treated with intraperitoneal ALT-803 displayed an NK dependent significant decrease in tumor. CONCLUSIONS: ALT-803 enhances NK cell cytotoxicity against ovarian cancer in vitro and in vivo and is able to rescue functionality of NK cells derived from ovarian cancer patient ascites. These findings suggest that ALT-803 has the potential to enhance NK cell-based immunotherapeutic approaches for the treatment of ovarian cancer.

Longitudinal dental maturation of children with complete unilateral cleft lip and palate: A case-control cohort study.

OBJECTIVES: Many reports suggest that children with cleft lip and palate (CLP) have delayed dental development and asymmetrical timing of tooth-pair formation. We aimed to investigate the dental maturation of permanent teeth in children with complete unilateral CLP (UCLP) and compare the findings with non-CLP children. SETTING AND SAMPLE POPULATION: This case-control study used 115 radiographs of children with complete UCLP and controls (non-CLP children matched on age, gender and ethnicity) from a hospital-based dental clinic in Singapore. MATERIAL AND METHODS: Orthopantomographs of 60 children with complete UCLP (5-9 years old) and 55 children (9-13 years old) from the same cohort were investigated using the Demirjian's method and compared with controls to determine if there were any differences in dental maturation with age. RESULTS: Delayed dental maturation was found in the 5- to 9-year-old children with UCLP compared to controls by 0.55 years (standard deviation: 0.75) (P<.001). There was no significant difference between the dental maturation of children with UCLP and controls in the 9- to 13-year-old group (P=.744). The group with UCLP had higher risk of asymmetrically developing tooth pairs than the control group for both age groups (P<.001). CONCLUSION: No difference in dental maturation between UCLP and controls in the 9- to 13-year-old group was found. However, there was diametrical difference in dental maturation in the 5- to 9-year-old group, which attenuated as they grew older. There was a consistently higher risk of asymmetrical tooth formation in children with UCLP than in controls.

Genetic variation in Vibrio parahaemolyticus isolated from the aquacultural environments.

UNLABELLED: Environmental strains of Vibrio parahaemolyticus, a foodborne pathogen, were isolated from milkfish and grouper aquaculture facilities in southern Taiwan and characterized by pulsed-field gel electrophoresis (PFGE) and polymerase chain reaction targeting on the virulence-associated and genomic island (VPaI) marker genes. Analyses of 62 environmental isolates, including two putative pathogenic isolates, by NotI-PFGE revealed 11 pulse-type clusters with a similarity of 85%. Some of the T3SS2α-associated genes (vopB2, vopC and vopT) were not present in all of these two putative pathogenic isolates. Marker genes of VPaI-1 (MTase gene), VPaI-2 (VP0636) and VPaI-3 (VP1073 and VP1077) were detected in 14-100% of the environmental isolates examined, and the VP1073 and VP1077 of VPaI-3 marker genes were not detected. This study confirmed the high genetic variability of the environmental isolates including the putative pathogenic strains and identified some marker genes of VPaI in the environmental V. parahaemolyticus isolates. SIGNIFICANCE AND IMPACT OF THE STUDY: Vibrio parahaemolyticus is a prevalent seafood-borne enteropathogen with the appearance of pandemic O3:K6 strains in 1996. This study characterized the environmental nontoxigenic and toxigenic isolates by pulsed-field gel electrophoresis and the presence of marker genes of genomic islands. Results showed that the T3SS2α-associated genes are not present in all environmental tdh(+) isolates, and the presence of movable elements may contribute to genetic variation in the environmental V. parahaemolyticus isolates.

Characterization of a 1D-imaging high-energy x-ray backlighter driven by the National Ignition Facility Advanced Radiographic Capability laser.

Plastic deformation of samples compressed to Mbar pressures at high strain rates at the National Ignition Facility (NIF) forms the basis of ongoing material strength experiments in conditions relevant to meteor impacts, geophysics, armor development, and inertial confinement fusion. Hard x-ray radiography is the primary means of measuring the evolution of these samples, typically employing a slit-collimated high-Z microdot driven by the NIF laser to generate >40 keV x rays [E. Gumbrell et al., Rev. Sci. Instrum. 89, 10G118 (2018) and C. M. Huntington et al., Rev. Sci. Instrum. 89, 10G121 (2018)]. Alternatively, a dysprosium "micro-flag" target driven by the Advanced Radiographic Capability laser (∼2 kJ, 10 ps) can deliver significantly higher spatiotemporal resolution [M. P. Hill et al., Rev. Sci. Instrum. 92, 033535 (2021)], especially in high-opacity samples. Initial experiments revealed problematic brightness and spectral gradients from this source, but by radiographing a set of diamond-turned, 105 µm-thick Pb test objects and supported by simulations using the 3D Monte Carlo code GEANT4, these geometry-dependent gradients across the field of view are quantified and mitigation strategies are assessed. In addition to significantly enhancing the modulation transfer function compared to the existing system, image stacking from multiple layers of image plate is shown to almost double the signal to noise ratio that will reduce uncertainties in future dynamic strength experiments.

Increased single strand breaks in DNA of lymphocytes from diabetic subjects.

Certain aspects of the chronic complications of diabetes suggest that, with time, the abnormal metabolic milieu leads to irreversible changes in some cell populations. Since we have previously observed that high glucose concentrations induce an increase in single strand breaks in the DNA of cultured human endothelial cells, we have investigated whether the same abnormality occurs in cells derived from the in vivo diabetic environment. Peripheral blood lymphocytes obtained from 21 type I diabetic patients and age- and sex-matched controls were tested for rate of unwinding in alkali (a measure of DNA single strand breaks). The patients were subdivided into two groups on the basis of glycohemoglobin values above or below 9%. The group with glycohemoglobin values of 12.9 +/- 2.4% (mean +/- SD), but not the group with glycohemoglobin values of 7.4 +/- 1.5%, showed accelerated unwinding of lymphocyte DNA when compared to controls (P less than 0.01). These studies suggest that poorly controlled diabetes may result in DNA lesions, whose impact on long-term complications deserves to be investigated.

Role of gastrin heptadecapeptide in the acid secretory response to amino acids in man.

Amino acids and peptides release gastrin and stimulate gastric acid secretion. However, the relation between gastrin release and acid secretory response is unclear. An isotonic mixed amino acid solution (casein hydrolysate) was continuously infused into the stomach of eight healthy human subjects. Acid secretion, measured by in vivo intragastric titration, increased 12.8 meq/h over the response to intragastric infusion of isotonic saline. Plasma gastrin heptadecapeptide (G-17) concentration, measured by specific radioimmunoassay, increased 13 pmol/liter during intragastric amino acid infusion. To determine whether this rise in plasma G-17 concentration could account for some or all of the acid secretory response, several doses of synthetic human G-17-I were infused intravenously into the same subjects. During i.v. G-17-I infusion, the stomach was continuously infused with isotonic saline. By graphically relating plasma G-17 concentration during i.v. G-17 infusion to concomitant acid secretion, it was determined that a 13-pmol/liter rise in plasma G-17 concentration could increase acid secretion 14.8 meq/h. Therefore, the rise in plasma G-17 concentration during intragastric amino acid infusion could have produced all of the observed acid secretory response. This suggests that gastrin heptadecapeptide is the major physiologic mediator of the human acid secretory response to meals containing mixed amino acids.

Refractory epilepsy in a Chinese population.

OBJECTIVES: To investigate the proportion of Chinese patients with intractable seizures and the risk factors leading to refractory epilepsy. METHODS: Consecutive patients over 14 years of age attending a Neurology clinic were evaluated. Patients with epilepsy were classified into two groups according to their seizure control: refractory or seizure-free. Epilepsy was classified as idiopathic as defined by age-related onset and typical electroclinical characteristics, symptomatic if secondary to a structural abnormality and cryptogenic if the cause was unknown. Age, sex, epilepsy syndrome classification, aetiology, presence of mental retardation and the number of drugs used were compared between patients with refractory epilepsy and those in remission. RESULTS: Among 260 adolescent and adult patients with a mean age of 34 years (range 15-79), complete seizure control was achieved in 157 (60%) cases. Multivariate binomial logistic regression analysis showed that patients with mesial temporal sclerosis (OR=7.6, 95% CI 3.53-16.4, p<0.01) and the presence of mental retardation (OR=9.39, 95% CI 3.98-22.12, p<0.01) were more likely to develop pharmacoresistant epilepsy. CONCLUSION: In adults the underlying aetiology is an important factor as to whether patients develop intractable seizures. Poor control was also associated with the presence of mesial temporal sclerosis and mental retardation.

Physicochemical approach to the purification of human alpha1-fetoprotein from the ascites fluid of a hepatoma-bearing patient.

A method for the purification of human alpha1-fetoprotein from the ascites fluid of a hepatoma-bearing patient is described that is capable of yielding large quantities of pure alpha1-fetoprotein within a relatively short period of time. The technique is based entirely on the physicochemical properties of the alpha1-fetoprotein molecule and uses sequential purification steps: ion-exchange chromatography on DEAE-Sephadex A-50, molecular-sieve chromatography on Sephadex G-200, negative-affinity chromatography on Sepharose-Blue Dextran, positivepaffinity chromatography on concanavalin A-Sepharose and, finally, molecular-sieve chromatography on Sephadex G-100. The efficiency of the entire procedure in its present form is 15% of the alpha1-fetoprotein activity of the starting preparation from ascites fluid. The purity of the final product was shown by polyacrylamide gel electrophoresis, radioimmunoelectrophoresis, and determinations of the NH2-terminal and COOH-terminal amino acid residues of the alphs1-fetoprotein isolated. Amino acid analysis of the final product revealed a composition very similar to those reported for alpha-fetoprotein preparations that have been previously isolated by the use of immunochemical technology.

Functional calcium imaging in zebrafish lateral-line hair cells.

Sensory hair-cell development, function, and regeneration are fundamental processes that are challenging to study in mammalian systems. Zebrafish are an excellent alternative model to study hair cells because they have an external auxiliary organ called the lateral line. The hair cells of the lateral line are easily accessible, which makes them suitable for live, function-based fluorescence imaging. In this chapter, we describe methods to perform functional calcium imaging in zebrafish lateral-line hair cells. We compare genetically encoded calcium indicators that have been used previously to measure calcium in lateral-line hair cells. We also outline equipment required for calcium imaging and compare different imaging systems. Lastly, we discuss how to set up optimal imaging parameters and how to process and visualize calcium signals. Overall, using these methods, in vivo calcium imaging is a powerful tool to examine sensory hair-cell function in an intact organism.

Severe acute respiratory syndrome outbreak promotes a strong sense of professional identity among nursing students.

This is a phenomenological study that examined nursing students' perception of nursing professional identity during severe acute respiratory syndrome (SARS) outbreak in Hong Kong in 2003. The aim of the study was to find out how the impact of the SARS event might have affected nursing students in identification with the nursing profession. A total of 10 nursing students were interviewed. This study showed that the SARS crisis enhanced a reconstruction of worldview and affirmed the professional identity of nursing students. Central themes derived from the interview were (1) appreciation and sharing of nursing identity; (2) a sense of moral duty; (3) a change of worldview and feeling of self-growth. This study provided insights to nursing education that acquisition of professional identity could be enhanced through reflective appreciation of critical events such as SARS.

Improving the binding affinity of an antibody using molecular modeling and site-directed mutagenesis.

Activated Factor X releases F1.2, a 271-amino acid peptide, from the amino terminus of prothrombin during blood coagulation. A nine-amino acid peptide, C9 (DSDRAIEGR), corresponding to the carboxyl terminus of F1.2 was synthesized and used to produce a monoclonal antibody, TA1 (K(D)) 1.22 x 10(-6) M). To model the TA1 antibody, we entered the sequence information of the cloned TA1 Fv into the antibody modeling program, ABM, which combines homology methods, conformational search procedures, and energy screening and has proved to be a reliable and reproducible antibody modeling method. Using a novel protein fusion procedure, we expressed the C9 peptide fused to the carboxyl terminus of the PENI repressor protein from Bacillus licheniformis in Escherichia coli. We constructed fusion proteins containing alanine substitutions for each amino acid in the C9 epitope. Binding studies, using the C9 alanine mutants and TA1, and spatial constraints predicted by the modeled TA1 binding cleft enabled us to establish a plausible conformation for C9 complexed with TA1. Furthermore, based on binding results of conservative amino acid substitutions in C9 and mutations in the antibody, we were able to refine the complex model and identify antibody mutations that would improve binding affinity.

Display of functional alphabeta single-chain T-cell receptor molecules on the surface of bacteriophage.

The ability to display functional T-cell receptors (TCR) on the surface of bacteriophage could have numerous applications. For instance, TCR phage-display could be used to develop new strategies for isolating TCRs with unique specificity or it could be used to carry out mutagenesis studies on TCR molecules for analyzing their structure-function. We initially selected a TCR from the murine T-cell hybridoma, DO11.10, as our model system, and genetically engineered a three domain single-chain TCR (scTCR) linked to the gene p8 protein of the Escherichia coli bacteriophage fd. Immunoblotting studies revealed that (1) E. coli produced a soluble scTCR/p8 fusion protein and (2) the fusion protein was packaged by the phage. Cellular competition assays were performed to evaluate the functionality of the TCR and showed the DO11.10 TCR-bearing phage could significantly inhibit stimulation of DO11.10 T hybridoma cells by competing for binding to immobilized MHC/peptide IA(d)/OVA(323-339). Flow cytometric analysis was carried out to evaluate direct binding of DO11.10 TCR-bearing phage onto the surface of cells displaying either IAd containing irrelevant peptide or OVA peptide. The results revealed binding of DO11.10 TCR-bearing phage only on cells expressing IA(d) loaded with OVA peptide showing TCR fine specificity for peptide. To illustrate the generality of TCR phage-display, we also cloned and displayed on phage a second TCR which recognizes a peptide fragment from human tumor suppressor protein p53 restricted by HLA-A2. These findings demonstrate functional TCR can be displayed on bacteriophage potentially leading to the development of novel applications involving TCR phage-display.

Antiinflammatory 2,6-di-tert-butyl-4-(2-arylethenyl)phenols.

A series of 2,6-di-tert-butyl-4-(2-arylethenyl)phenols was prepared and examined for their ability to inhibit cyclooxygenase and 5-lipoxygenase in vitro and developing adjuvant arthritis in vivo in the rat. Structure-activity relationships are discussed. Among the best compounds is (E)-2,6-di-tert-butyl-4-[2-(3-pyridinyl)ethenyl]phenol (7d). It has an IC50 of 0.67 microM for cyclooxygenase and 2.7 microM for 5-lipoxygenase and an ED50 of 2.1 mg/kg in developing adjuvant arthritis. Additional in vivo data are reported for 7d.

Bis basic substituted diaminobenzobisthiazoles as potential antiarthritic agents.

A series of benzobisthiazoles were screened for antiinflammatory activity in the carrageenan paw edema and adjuvant arthritis tests. Compound 26, 2,6-bis(N,N-diethylamino)benzo[1,2-d:5,4-d']bisthiazole, was found to inhibit the swelling of the uninjected paw in the prophylactic adjuvant arthritis model with an ED50 of 2.3 mg/kg orally. As with most compounds of this series, 26 was inactive in acute model of inflammation, such as paw edema; like steroids, it showed activity in the granuloma pouch assay but did not inhibit cyclooxygenase, indicating a mode of action different from the classical nonsteroidal antiinflammatory drugs (NSAID's). At doses higher than those producing antiinflammatory activity, 26 had some immunoregulating properties.

Effect of structure on potency and selectivity in 2,6-disubstituted 4-(2-arylethenyl)phenol lipoxygenase inhibitors.

A series of 2,6-disubstituted 4-(2-arylethenyl)phenols with potent human neutrophil 5-lipoxygenase (5-LO) inhibiting activity (IC50S in the 10(-7) M range) and weaker human platelet cyclooxygenase (CO) inhibiting activity (IC50S in the 10(-6) M range) is described. This series evolved from the chemical modification of an antiinflammatory dual CO/5-LO inhibitor, 2,6-di-tert-butyl-4-[2-(3-pyridyl)ethenyl]phenol (BI-L-93 BS). The potency and selectivity for 5-LO inhibition is greatly influenced by the nature of the substituents in the 2- and 6-positions. Other structure-activity relationships that determine relative 5-LO and CO potency are discussed. In vivo activity against antigen-induced leukotriene-mediated bronchoconstriction and cell influx in guinea pigs is presented. Representatives of the series are active when administered at 30 mg/kg ip.

Benzoxazolamines and benzothiazolamines: potent, enantioselective inhibitors of leukotriene biosynthesis with a novel mechanism of action.

A series of benzoxazolamine and benzothiazolamine analogs that inhibit leukotriene (LT) biosynthesis are described. The initial lead, (S)-N-(benzothiazol-2- yl)phenylalanine ethyl ester (5a), was discovered in a screening program for inhibition of Ca-ionophore-A23187-induced LTB4 release in human polymorphonuclear leukocytes (IC50 0.23 microM). Through structural modification, it was determined that hydrophobic substituents in the 5-position and replacement of the phenyl ring of phenylalanine with a cyclohexyl group greatly enhance potency. Several ester bioisosteres that retain potency and enantiomeric selectivity are described. Lead optimization culminated in (S)-N-[2-cyclohexyl-1-(2-pyridinyl)ethyl]-5-methyl-2-benzoxazolamine+ ++ (43b), IC50 0.001 microM. The compounds described are not inhibitors of 5-lipoxygenase but, rather, act at the level of arachidonic acid release.