Host range expansion of Acinetobacter phage vB_Ab4_Hep4 driven by a spontaneous tail tubular mutation.

Bacteriophages (phages) represent promising alternative treatments against multidrug-resistant Acinetobacter baumannii (MDRAB) infections. The application of phages as antibacterial agents is limited by their generally narrow host ranges, so changing or expanding the host ranges of phages is beneficial for phage therapy. Multiple studies have identified that phage tail fiber protein mediates the recognition and binding to the host as receptor binding protein in phage infection. However, the tail tubular-dependent host specificity of phages has not been studied well. In this study, we isolated and characterized a novel lytic phage, vB_Ab4_Hep4, specifically infecting MDRAB strains. Meanwhile, we identified a spontaneous mutant of the phage, vB_Ab4_Hep4-M, which revealed an expanded host range compared to the wild-type phage. A single mutation of G to C was detected in the gene encoding the phage tail tubular protein B and thus resulted in an aspartate to histidine change. We further demonstrated that the host range expansion of the phage mutant is driven by the spontaneous mutation of guanine to cytosine using expressed tail tubular protein B. Moreover, we established that the bacterial capsule is the receptor for phage Abp4 and Abp4-M by identifying mutant genes in phage-resistant strains. In conclusion, our study provided a detailed description of phage vB_Ab4_Hep4 and revealed the tail tubular-dependent host specificity in A. baumannii phages, which may provide new insights into extending the host ranges of phages by gene-modifying tail tubular proteins.

Association between CCL5, CCL11, and CCL17 polymorphisms and atopic dermatitis risk: A systematic review and meta-analysis.

BACKGROUND: Atopic dermatitis (AD) is a common and recurrent inflammatory disease with strong genetic susceptibility. The abnormal production of chemokines plays an important role in the occurrence and development of AD. METHODS: A comprehensive online literature search was performed in databases of China National Knowledge Infrastructure, Wanfang, VIP China Science and Technology Journal Database, China Biomedical Literature Database, PubMed, Embase and Cochrane Library to retrieve relevant articles published from January 2000 to October 2022. The odds ratio (OR) with its 95% confidence interval (CI) was employed to calculate this relationship. RESULTS: A total of 7 studies were finally screened out, including 1316 AD patients and 1099 controls. There were 3 studies for CC chemokine ligand 5 (CCL5) polymorphisms, 2 for CCL11 polymorphisms, and 2 for CCL17 polymorphisms, respectively. The meta-analysis revealed a significant association between the CCL5 - 403G/A polymorphism and AD under the allelic model (A vs G: OR = 1.25, 95% CI = 1.02-1.52, P = .03), heterozygous model (AG vs GG: OR = 1.40, 95% CI = 1.08-1.80, P = .01) and dominant model (AA + AG vs GG: OR = 1.38, 95% CI = 1.08-1.76, P = .01) in a fixed-effect model. The allelic model (G vs C: OR = 1.46, 95% CI = 1.07-1.98, P < .01) and dominant model (GG + GC vs CC: OR = 1.74, 95% CI = 1.23-2.47, P < .001) of the CCL5 - 28C/G polymorphism were also associated with an increased risk of AD. However, this significant association was not found in other alleles and genotypes (P > .05). CONCLUSION: Our results show that the A allele, AG and AA + AG genotypes of the CCL5 - 403G/A polymorphism, the G allele and GG + GC genotype of the CCL5 - 28C/G polymorphism are risk factors for AD. Future studies with large population are still needed to further explore those correlations.

The PER3rs772027021 SNP induces pigmentation phenotypes of dyschromatosis universalis hereditaria.

Dyschromatosis universalis hereditaria (DUH) is a pigmentary genodermatosis characterized by a mixture of hyperpigmented and hypopigmented macules distributed randomly over the body. Although Sterile Alpha motif- and SH3 domain-containing protein 1 (SASH1) and ATP-binding cassette subfamily B, member 6 (ABCB6) have been identified as causative genes for this disorder, some cases involve unknown pathogenic genes. In this study, whole-exome sequencing, data analysis, and Sanger sequencing were utilized for a four-generation extended Chinese family with DUH. A single-nucleotide polymorphism (SNP) (c. 517C > T (p.P173S), rs772027021) variant in exon 5 of Period Circadian Regulator 3 (PER3) (NM_001289861) was detected in each affected individual of the DUH family; the c. 517C > T SNP of PER3 (PER3rs772027021 SNP) and a novel mutation in exon 14 of SASH1 (c. 1574C > G (p.T525R)) were both found in the proband. The affected individuals carrying PER3rs772027021 SNP in this family demonstrated mild-pigmented phenotypes compared to those of the proband carrying PER3rs772027021 SNP and SASH1 T525R mutation. Increased melanin synthesis was induced by PER3rs772027021 SNP in the melanocytes of affected epithelial tissues. Mutated SASH1 or PER3rs772027021 SNP alone or cooperation of mutation of SASH1 and PER3rs772027021 SNP synergistically led to increased melanin synthesis and enhanced proliferation of melanoma cells in vitro. We also phenotypically characterized a commercially available zebrafish mutant line harboring the PER3rs772027021 SNP to induce melanocyte proliferation in vivo. Our results are the first to reveal that this PER3 SNP may be pathogenic for a novel DUH subtype with mild hyperpigmented and/or hypopigmented phenotypes and that mutation of SASH1 and PER3 cooperatively promotes hyperpigmentation phenotypes. KEY MESSAGES: PER3 rs772027021 SNP is identified to be associated with hyperpigmentation and/or hypopigmentation phenotype and the novel pathogenic variant of PER3 rs772027021 SNP probably contributed the pathogenesis of DUH. SASH1T525R mutation is confirmed to associate with DUH. A novel autosomal dominant inheritance DUH subtype with mild pigmentated phenotypes is caused by the PER3rs772027021 SNP.

Sleep quality, circadian preferences, and mood among patients with acne vulgaris: a case-control study.

PURPOSE: Poor sleep and mood may be predisposing factors for acne. We aimed to investigate the associations between acne and sleep quality, circadian preferences, and mood. METHODS: This case-control study recruited patients with acne and age- and sex-matched healthy controls. We used the Investigator's Global Assessment to evaluate acne severity and various validated questionnaires to measure sleep quality, daytime sleepiness, sleep apnea, circadian preference, and mood symptoms. RESULTS: A total of 81 patients with acne (age: 21.6 ± 5.0 years, 52% female) and 76 controls were recruited. Compared to controls, patients had a higher score on the Pittsburgh Sleep Quality Index (5.2 ± 2.6 vs. 4.1 ± 2.3, p = 0.008) and State-Trait Anxiety Inventory (State: 44.6 ± 9.7 vs. 40.6 ± 6.6, p = 0.003; Trait: 47.9 ± 8.2 vs. 45.3 ± 6.2, p = 0.03), and a lower score on a reduced version of the Morningness and Eveningness Questionnaire (13.9 ± 2.6 vs. 14.7 ± 2.3, p = 0.05) and Epworth Sleepiness Scale (7.4 ± 3.4 vs. 8.6 ± 3.6, p = 0.04). Acne severity was associated with sleep quality (ß = 0.33), eveningness (ß = 0.34), depression (ß = 0.66), and anxiety (State: ß = 1.73; Trait: ß = 1.21), even when adjusted for education level and family history of acne. CONCLUSION: Acne is highly associated with poor sleep and mood. Dermatologists are advised to attend closely to the psychological impact of acne. Improvements in sleep and mood may benefit the treatment of acne.

Analysis of phenotype and pathogenic variants in a Chinese pedigree affected with Multiple synostoses syndrome type 1 / 中华医学遗传学杂志

OBJECTIVE@#To explore the clinical and genetic characteristics of a Chinese pedigree affected with Multiple synostoses syndrome type 1 (SYNS1).@*METHODS@#Clinical data of the proband and her family members were collected. Genomic DNA was extracted from peripheral blood samples. Whole-exome sequencing (WES) and whole-genome sequencing (WGS) were carried out for the proband and her parents.@*RESULTS@#The pedigree has comprised of 14 members from three generations, of whom six had manifested hearing loss, with other symptoms including proximal symphalangism, hemicylindrical nose, amblyopia, strabismus, brachydactyly, incomplete syndactyly, which fulfilled the diagnostic criteria for SYNS1. WES had detected no pathogenic single nucleotide variants and insertion-deletion (InDel) in the coding region of the NOG gene, whilst copy number variation (CNV) analysis indicated that there was a heterozygous deletion involving the NOG gene. WGS revealed a heterozygous deletion (54171786_55143998) in 17q22 of the proband. The CNV was classified as pathogenic based on the guidelines from the American College of Medical Genetics and Genomics (ACMG).@*CONCLUSION@#The heterozygous deletion in 17p22 involving the NOG gene probably underlay the pathogenesis of SYNS1 in this pedigree. Above finding has enriched the mutational spectrum of NOG. CNV should be considered when conventional sequencing has failed to detect any pathogenic variants in such patients.

Analysis of clinical phenotype and genetic variants among four Chinese pedigrees affected with Waardenburg syndrome / 中华医学遗传学杂志

OBJECTIVE@#To explore the genetic basis for four Chinese pedigrees affected with Waardenburg syndrome (WS).@*METHODS@#Four WS probands and their pedigree members who had presented at the First Affiliated Hospital of Zhengzhou University between July 2021 and March 2022 were selected as the study subjects. Proband 1, a 2-year-and-11-month female, had blurred speech for over 2 years. Proband 2, a 10-year-old female, had bilateral hearing loss for 8 years. Proband 3, a 28-year-old male, had right side hearing loss for over 10 years. Proband 4, a 2-year-old male, had left side hearing loss for one year. Clinical data of the four probands and their pedigree members were collected, and auxiliary examinations were carried out. Genomic DNA was extracted from peripheral blood samples and subjected to whole exome sequencing. Candidate variants were verified by Sanger sequencing.@*RESULTS@#Proband 1, with profound bilateral sensorineural hearing loss, blue iris and dystopia canthorum, was found to have harbored a heterozygous c.667C>T (p.Arg223Ter) nonsense variant of the PAX3 gene, which was inherited from her father. Based on the guidelines from the American College of Medical Genetics and Genomics (ACMG), the variant was classified as pathogenic (PVS1+PM2_Supporting+PP4), and the proband was diagnosed with WS type I. Proband 2, with moderate sensorineural hearing loss on the right side and severe sensorineural hearing loss on the left side, has harbored a heterozygous frameshifting c.1018_1022del (p.Val340SerfsTer60) variant of the SOX10 gene. Neither of her parents has harbored the same variant. Based on the ACMG guidelines, it was classified as pathogenic (PVS1+PM2_Supporting+PP4+PM6), and the proband was diagnosed with WS type II. Proband 3, with profound sensorineural hearing loss on the right side, has harbored a heterozygous c.23delC (p.Ser8TrpfsTer5) frameshifting variant of the SOX10 gene. Based on the ACMG guidelines, it was classified as pathogenic (PVS1+PM2_Supporting+PP4), and the proband was diagnosed with WS type II. Proband 4, with profound sensorineural hearing loss on the left side, has harbored a heterozygous c.7G>T (p.Glu3Ter) nonsense variant of the MITF gene which was inherited from his mother. Based on the ACMG guidelines, the variant was classified as pathogenic (PVS1+PM2_Supporting+PP4), and the proband was diagnosed with WS type II.@*CONCLUSION@#By genetic testing, the four probands were all diagnosed with WS. Above finding has facilitated molecular diagnosis and genetic counseling for their pedigrees.

The effect of ion environment changes on retention protein behavior during whey ultrafiltration process.

The factors affecting membrane fouling are very complex. In this study, the membrane fouling process was revealed from the perspective of ion environment changes, which affected the whey protein structure during ultrafiltration. It was found that the concentrations of Ca2+ and Na+ were overall increased and the concentrations of K+, Mg2+ and Zn2+ were decreased at an ultrafiltration time of 11 min, which made more hydrophilic groups buried inside and increased the content of α-helix, leading to more protein aggregation. The relatively higher K+ ratio in retention could lead to an antiparallel ß-sheet configuration, aspartic acid, glutamic acid and tryptophan increased, which resulted in more protein aggregation and deposition on the membrane surface at 17 min. When the ion concentration and ratio restored the balance and were close to the initial state in retention, the protein surface tension decreased, and the hydrophilic ability increased at 21-24 min.

Treatment of atopic dermatitis using topical antifungal drugs: A meta-analysis.

Several studies have focused on treating atopic dermatitis (AD) using topical antifungal drugs. However, their findings are inconsistent. This meta-analysis of randomized controlled trials (RCTs) aimed to evaluate the safety and efficacy of topical antifungal drugs for the treatment of AD. We searched prominent databases such as EMBASE, PubMed, Cochrane Library, China Biomedical Literature Database (CBM), China National Knowledge Infrastructure (CNKI), China Science and Technology Journal Database (VIP), and Wanfang Database to retrieve all RCTs on the use of topical antifungal drugs for the treatment of AD. The two authors independently performed screening, extraction, and quality evaluation of data based on inclusion and exclusion criteria. In addition, quantitative synthesis and qualitative description of the results were performed using Review Manager 5.3. Nine studies with a total of 785 subjects were included in the meta-analysis. Based on intervention measures, data were divided into three groups: topical antifungal drugs versus placebo, topical antifungal drugs versus topical glucocorticoids, and topical antifungal drugs plus topical glucocorticoids versus topical glucocorticoids. Risk-of-bias assessments revealed that the random distribution methods and allocation concealment were not ideal; further, some studies had incomplete data and reported selective results. Quantitative analysis revealed that in terms of effective rate, topical antifungal drugs are superior to topical glucocorticoids (p = 0.003), and topical antifungal drugs plus topical glucocorticoids are superior to topical glucocorticoids (p = 0.001). However, no significant differences in adverse reactions were observed between the three groups (p > 0.05). The safety and efficacy of topical antifungal drugs for treating AD cannot be accurately evaluated with existing data. Therefore, additional high-quality and large-sample prospective RCTs are required for further validation to determine the appropriateness of topical antifungal drug use for the treatment of AD in clinical settings.

Association between Genetic Polymorphisms in Methylenetetrahydrofolate Reductase and Risk of Autoimmune Diseases: A Systematic Review and Meta-Analysis.

Methylenetetrahydrofolate reductase (MTHFR) is a critical rate-limiting enzyme in the homocysteine/methionine metabolism pathway that is implicated in the pathogenesis and progression of autoimmune diseases. Previous association studies have been performed to investigate the effect of polymorphisms in MTHFR on the risk of autoimmune diseases with inconsistent results. Therefore, this meta-analysis was designed to assess the association between the MTHFR 677 C/T and 1298 A/C polymorphisms and the susceptibility to autoimmune diseases. We identified reports by a literature search in the following electronic databases: PubMed, Ovid, Web of science, and China National Knowledge Infrastructure. Statistical analyses of the summary odds ratios (ORs) and 95% confidence intervals (CIs) were done using STATA software. In a recessive genetic model, the MTHFR 677 C/T polymorphism was associated with an increased risk of Behcet's disease (OR = 1.97, 95% CI, 1.31-2.97), multiple sclerosis (OR = 1.57, 95% CI, 1.03-2.38), and ankylosing spondylitis (OR = 2.90, 95% CI, 1.92-4.38). The MTHFR 1298 A/C polymorphism was associated an increased risk of multiple sclerosis in a heterozygote comparison (OR = 2.36, 95% CI, 1.29-4.30) and in a dominant model (OR = 2.31, 95% CI, 1.24-4.29). This meta-analysis demonstrated that the MTHFR 677 C/T was a risk factor for Behcet's disease, multiple sclerosis, and ankylosing spondylitis, and the 1298 A/C was a risk factor for multiple sclerosis.

Application of micro-classes combined with flipped classrooms based on short videos and images in "early rehabilitation nursing of stroke patients with hemiplegia" / 中华医学教育探索杂志

Objective:To explore the application effect of micro-classes combined with flipped classrooms based on short videos and images in "early rehabilitation nursing of stroke patients with hemiplegia".Methods:A total of 70 nursing students who were interns in our department from June 2019 to April 2021 were selected as the research objects, among which, 35 nursing students who entered the department from June 2019 to March 2020 were selected as the control group, using traditional teaching, and 35 nursing students who entered the department from July 2020 to April 2021 were selected as the research group, adopting the micro-classes combined with flipped classrooms teaching based on short videos and images. After the teaching, the test scores of the two groups of students, the students' satisfaction with the teaching methods, their critical thinking ability and the students' autonomous learning ability were evaluated. SPSS 17.0 was used for independent-sample t test and paired-sample t test. Results:After the teaching, the theoretical scores and clinical practice assessment scores of the research group were better than those of the control group, and the difference was statistically significant ( P<0.05); the students in the research group were more satisfied with the teaching method than those in the control group. After the teaching, the scores of 7 dimensions of critical thinking ability of the students in the research group were higher than those of the students in the control group; the scores and total scores of 4 dimensions of the self-learning ability evaluation were higher in the research group than those in the control group. Conclusion:Micro-classes combined with flipped classrooms teaching based on short videos and images can improve the teaching effect of "early rehabilitation nursing for patients with stroke and hemiplegia".

Association of MTHFR C677T polymorphism and type 2 diabetes mellitus (T2DM) susceptibility.

INTRODUCTION: Methylenetetrahydrofolate reductase (MTHFR) is essential in mediating folate metabolism, and thus plays an important role in diabetes and diabetic complications. MTHFR C677T (rs1801133 C>T) polymorphism has been proposed to be linked with type 2 diabetes mellitus (T2DM) susceptibility. However, the conclusions are inconsistent. Therefore, we rechecked their linkage aiming to obtain a more reliable estimation by performing an updated meta-analysis. METHODS: We searched electronic databases PubMed, EMBASE, CNKI, and Wanfang to obtain studies updated to October 2019. RESULTS: After carefully screening, we finally incorporated 68 studies with 10,812 cases and 8,745 controls. The genotype frequency of C677T polymorphism was analyzed pooled to generate odds ratios (ORs) and 95% confidence intervals (CIs). Pooled results presented that MTHFR C677T polymorphism was significantly associated with T2DM under homozygous (OR = 1.64, 95% CI = 1.39-1.94), heterozygous (OR = 1.38, 95% CI = 1.20-1.59), recessive (OR = 1.41, 95% CI = 1.23-1.61), dominant (OR = 1.47, 95% CI = 1.27-1.70), and allele (OR = 1.37, 95% CI = 1.23-1.52) genetic models. Stratified analysis demonstrated that C677T genotype was associated with T2DM in Asian populations, but not Caucasian and African populations. CONCLUSION: Our results indicated that MTHFR C677T polymorphism confers to T2DM, especially in Asian populations. Much more large-scale case-control studies are needed to strengthen such conclusion in the future.

[Development of a near-infrared fluorescence imaging system based on fluorescence properties of methylene blue].

OBJECTIVE: To develop a near-infrared fluorescence imaging system based on the fluorescence properties of methylene blue. METHODS: According to the optical properties of methylene blue, we used a custom-made specific LED light source and an interference filter, a CCD camera and other relevant components to construct the near-infrared fluorescence imaging system. We tested the signal-to-background ratio (SBR) of this imaging system for detecting methylene blue under different experimental conditions and analyzed the SBR in urine samples collected from 15 Wistar rats with intravenous injection of methylene blue at the doses of 0, 1.4, 1.6, 1.8, or 2.0 0 mg/kg methylene blue. RESULTS: The SBR of this imaging system for detecting methylene blue was affected by the concentration of methylene blue and the distance from the sample (P<0.05). In the urine samples from Wistar rats, the SBR varied with the the injection dose, and the rats injected with 1.6 mg/kg methylene blue showed the highest SBR (8.71∓0.20) in the urine (P<0.05). CONCLUSION: This near-infrared fluorescence imaging system is useful for fluorescence detection of methylene blue and can be used for real-time recognition of ureters during abdominal surgery.

[Differences in dielectric properties between mucosal and serosal surface of malignant colorectal tissues, adjacent tissues at 1 cm and 3 cm and normal colorectal tissues].

OBJECTIVE: To investigate the differences in dielectric properties (relative permittivity and conductivity) between the mucosal surface and serosal surface of malignant colorectal tissues, adjacent tissues at 1 cm and 3 cm from the tumor focus and normal colorectal tissues. METHODS: The dielectric properties of the mucosal and serosal surface of malignant colorectal tissues, adjacent tissues (1 cm and 3 cm) and normal colorectal tissues from 39 patients with colorectal cancer were measured with an open-ended coaxial probe within the frequency range of 50 MHz-3 GHz, and the corresponding dielectric properties were analyzed respectively; statistical tests of the data were used to analyze the dielectric properties at 6 specific frequency points. RESULTS: The dielectric properties were significantly higher in the malignant mucosa surface than in the adjacent tissues and normal colorectal tissues at the 6 specific frequency points (P<0.01). The dielectric properties decreased progressively in adjacent tissues at 1 cm and 3 cm and normal mucosa surface. The mucosal and serosal surface of malignant tissues showed significant differences in dielectric properties at 64 MHz, 128 MHz, 298 MHz, 433 MHz, and 915 MHz (P<0.01) but not at 2450 MHz (P>0.01), but such differences were not observed in normal tissues (P>0.01). CONCLUSION: The dielectric properties of the mucosal surface of the mucosal decrease in the order of malignant colorectal tissue, adjacent tissues at 1 cm and 3 cm from the tumor foci and normal colorectal tissues. The dielectric properties are higher in the mucosal surface than in the serosal surface in the malignant tissue, but comparable in normal colorectal tissues.

Calculations of spin-polarized Goos-Hänchen displacement in magnetically confined GaAs/Al x Ga1-x As nanostructure modulated by spin-orbit couplings.

We theoretically investigate Goos-Hänchen (GH) displacement by modelling the spin transport in an archetypal device structure-a magnetically confined GaAs/Al x Ga1-x As nanostructure modulated by spin-orbit coupling (SOC). Both Rashba and Dresselhaus SOCs are taken into account. The degree of spin-polarized GH displacement can be tuned by Rashba or Dresselhaus SOC, i.e. interfacial confining electric field or strain engineering. Based on such a semiconductor nanostructure, a controllable spatial spin splitter can be proposed for spintronics applications.

Lupane Triterpenes from the Leaves of Acanthopanax gracilistylus.

The phytochemical study on the leaves of Acanthopanax gracilistylus (Araliaceae) resulted in the discovery of a new lupane-triterpene compound, acangraciligenin S (1), and a new lupane-triterpene glycoside, acangraciliside S (2), as well as two known ones, 3α,11α-dihydroxy-lup-20(29)-en-23,28-dioic acid (3) and acankoreoside C (4). Their chemical structures were elucidated by mass, 1D- and 2D-nuclear magnetic resonance (NMR) spectroscopy. The chemical structures of the new compounds 1 and 2 were determined to be 1ß,3α-dihydroxy-lup-20(29)-en-23, 28-dioic acid and 1ß,3α-dihydroxy-lup-20(29)-en-23,28-dioic acid 28-O-[α-l-rhamnopyranosyl-(1→4)-ß-d-glucopyranosyl-(1→6)-ß-d-glucopyranosyl] ester, respectively. The anti-neuroinflammatory activity of the selective compounds, 1 and 3, were evaluated with lipopolysaccharide (LPS)-induced BV2 microglia. The tested compounds showed moderate inhibitory effect of nitric oxide (NO) production.

Status Analysis of Preventing Stress Ulcer in Hip/knee Replacement Patients / 中国药师

Objective: To investigate the current situation of stress ulcer prevention in patients with orthopedic joint replacement in our hospital and explore the necessity of preventing bleeding of peptic ulcer in patients with hip/knee replacement. Methods: The ca-ses of hip/knee replacement discharged from our hospital in September 2017 were retrospectively analyzed. The age and gender of the patients were analyzed. The underlying medical conditions, the related laboratory indices and the uses of stress ulcer prevention drugs, analgesic and anticoagulation drugs were statistically analyzed. Results: A total of 109 cases were collected including 40 cases of hip replacement and 69 cases of knee replacement. The median of age was 63. The use rate of non-steroidal analgesic drugs was 98. 16% , that of deep venous thrombosis prevention drugs was 95. 4% , and that of stress ulcer prevention drugs was 67. 9% . No patient suffered from gastrointestinal bleeding. Conclusion: The majority of patients undergoing hip /knee replacement are the elderly, and the knee replacement patients are older with more operation duration and more bleeding during the hip replacement. Nonsteroidal anti-inflamma-tory drugs and the drugs for preventing deep venous thrombosis are widely used during perioperative period. At present, it is still uncer-tain whether the population needs regular prevention of stress ulcers. However, the combination of aspirin and NSAID is a risk factor. The other high-risk factors, as well as the necessity of prevention medication, still need to be investigated in a larger scale.

Development of a near-infrared fluorescence imaging system based on fluorescence properties of methylene blue / 南方医科大学学报

<p><b>OBJECTIVE</b>To develop a near-infrared fluorescence imaging system based on the fluorescence properties of methylene blue.</p><p><b>METHODS</b>According to the optical properties of methylene blue, we used a custom-made specific LED light source and an interference filter, a CCD camera and other relevant components to construct the near-infrared fluorescence imaging system. We tested the signal-to-background ratio (SBR) of this imaging system for detecting methylene blue under different experimental conditions and analyzed the SBR in urine samples collected from 15 Wistar rats with intravenous injection of methylene blue at the doses of 0, 1.4, 1.6, 1.8, or 2.0 0 mg/kg methylene blue.</p><p><b>RESULTS</b>The SBR of this imaging system for detecting methylene blue was affected by the concentration of methylene blue and the distance from the sample (P<0.05). In the urine samples from Wistar rats, the SBR varied with the the injection dose, and the rats injected with 1.6 mg/kg methylene blue showed the highest SBR (8.71∓0.20) in the urine (P<0.05).</p><p><b>CONCLUSION</b>This near-infrared fluorescence imaging system is useful for fluorescence detection of methylene blue and can be used for real-time recognition of ureters during abdominal surgery.</p>

Differences in dielectric properties between mucosal and serosal surface of malignant colorectal tissues, adjacent tissues at 1 cm and 3 cm and normal colorectal tissues / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the differences in dielectric properties (relative permittivity and conductivity) between the mucosal surface and serosal surface of malignant colorectal tissues, adjacent tissues at 1 cm and 3 cm from the tumor focus and normal colorectal tissues.</p><p><b>METHODS</b>The dielectric properties of the mucosal and serosal surface of malignant colorectal tissues, adjacent tissues (1 cm and 3 cm) and normal colorectal tissues from 39 patients with colorectal cancer were measured with an open-ended coaxial probe within the frequency range of 50 MHz-3 GHz, and the corresponding dielectric properties were analyzed respectively; statistical tests of the data were used to analyze the dielectric properties at 6 specific frequency points.</p><p><b>RESULTS</b>The dielectric properties were significantly higher in the malignant mucosa surface than in the adjacent tissues and normal colorectal tissues at the 6 specific frequency points (P<0.01). The dielectric properties decreased progressively in adjacent tissues at 1 cm and 3 cm and normal mucosa surface. The mucosal and serosal surface of malignant tissues showed significant differences in dielectric properties at 64 MHz, 128 MHz, 298 MHz, 433 MHz, and 915 MHz (P<0.01) but not at 2450 MHz (P>0.01), but such differences were not observed in normal tissues (P>0.01).</p><p><b>CONCLUSION</b>The dielectric properties of the mucosal surface of the mucosal decrease in the order of malignant colorectal tissue, adjacent tissues at 1 cm and 3 cm from the tumor foci and normal colorectal tissues. The dielectric properties are higher in the mucosal surface than in the serosal surface in the malignant tissue, but comparable in normal colorectal tissues.</p>

Significantly enhanced substrate tolerance of Pseudomonas putida nitrilase via atmospheric and room temperature plasma and cell immobilization.

The objective of the study was to enhance the substrate tolerance of Pseudomonas putida nitrilase via atmospheric and room temperature plasma (ARTP) and cell immobilization. The mutant library was constructed by ARTP and rapidly screened by an OPA-TCA microscale reaction. A mutant strain of mut-D3 was obtained and its optimum substrate concentration was improved to 150mM from 100mM. It could accumulate 189g/L nicotinic acid (NA) from 3-cyanopyridine (3-CP), which was increased by 42% compared with that of wild type (WT). Additionally, composite immobilization of mut-D3 was performed and SA-PVA immobilized cells could catalyze 250mM 3-CP each batch with finally accumulating 346g/L NA, while free cells accumulated 175g/L NA. These results indicated that the free or immobilized catalysts of mut-D3 could serve as a good choice for NA production. This is the first report on mutation breeding of nitrilase-producing microorganisms by ARTP.