赤灵芝的致突变性试验

使用赤灵芝的水提取液、乙醇（３０％）提取液进行鼠伤寒沙门氏菌回复、小鼠骨髓多染红细胞微核和雄小鼠精子畸变等三种致突变试验。剂量为１０００μｇ．皿＾－１和５０００μｇ／皿＾－１的鼠伤寒沙门氏菌回复试验的结果为阴性。小鼠在服用７５００ｍｇ．ｋｇ＾－１的水提取液或２５００ｍｇ．ｋｇ＾－１的醇提取液时，微核试验和精子畸变试验结果均为阴性。     

Change in chromatogram patterns after volatilization of some aroclors, and the associated quantitation problems

PCBs with the highest vapor pressures (fewest chlorines) in Aroclors 1016, 1242, 1254 and 1268 were enriched in the vapor phase relative to the original Aroclor during volatilization from a glass surface for up to 8 hr. PCBs with the lowest vapor pressures (most highly chlorinated) were enriched in the corresponding residue. Thus, visual matching of gas chromatograms with those of Aroclor standards may not be sufficient to identify a specific Aroclor since the past history of a sample is often unknown. The enrichment also was detected using isomeric classes, but not using total chlorine content. The perchlorination method and the Webb-McCall method using all chromatographic peaks agreed quantitatively; this was not always so for the NIOSH multiple peaks and the Webb-McCall methods.     

莱菔硫烷对ox-LDL诱导血小板活化的抑制作用

目的：探讨莱菔硫烷（sulforaphane,SFN）对氧化低密度脂蛋白（oxidized low-density lipoprotein,ox-LDL）诱导血小板活化的影响及其可能的分子机制。方法：在体外实验中,将健康人纯化血小板与不同浓度的SFN(1.0、2.5、5.0μmol/L)共同孵育40 min,然后用ox-LDL激活血小板20 min,并检测血小板活化的指标,包括CD62P的表达、胞内血小板因子4(platelet factor4,PF4)和趋化因子配体5(chemokine ligand 5,CCL5)的释放水平。机制上,用Western blot蛋白免疫印迹法检测血小板肉瘤酪氨酸激酶（sarcoma tyrosine kinase,Src）及其下游的脾酪氨酸激酶（spleen tyrosine kinase,Syk）磷酸化水平;用活性氧（reactive oxygen species,ROS）检测试剂盒测定胞内总ROS水平。结果：ox-LDL诱导的血小板CD62P的表达以及PF4和CCL5的释放水平均可被SFN显著抑制（P <0.05）;SFN显著下调ox-LD...     

The use of urine proteomic and metabonomic patterns for the diagnosis of interstitial cystitis and bacterial cystitis

The advent of systems biology approaches that have stemmed from the sequencing of the human genome has led to the search for new methods to diagnose diseases. While much effort has been focused on the identification of disease-specific biomarkers, recent efforts are underway toward the use of proteomic and metabonomic patterns to indicate disease. We have developed and contrasted the use of both proteomic and metabonomic patterns in urine for the detection of interstitial cystitis (IC). The methodology relies on advanced bioinformatics to scrutinize information contained within mass spectrometry (MS) and high-resolution proton nuclear magnetic resonance (1H-NMR) spectral patterns to distinguish IC-affected from non-affected individuals as well as those suffering from bacterial cystitis (BC). We have applied a novel pattern recognition tool that employs an unsupervised system (self-organizing-type cluster mapping) as a fitness test for a supervised system (a genetic algorithm). With this approach, a training set comprised of mass spectra and 1H-NMR spectra from urine derived from either unaffected individuals or patients with IC is employed so that the most fit combination of relative, normalized intensity features defined at precise m/z or chemical shift values plotted in n-space can reliably distinguish the cohorts used in training. Using this bioinformatic approach, we were able to discriminate spectral patterns associated with IC-affected, BC-affected, and unaffected patients with a success rate of approximately 84%.     

Comparison of screening methods for detection of extended-spectrum beta-lactamases and their prevalence among Escherichia coli and Klebsiella species in Hong Kong

Three tests, the disk diffusion test, the double-disc synergy test and the inhibitor-potentiated disc diffusion test, were compared for their abilities to detect production of extended-spectrum beta-lactamases (ESBL) in 702 Escherichia coli and 472 Klebsiella spp. strains from four hospitals. Eleven percent E. coli and 13% Klebsiella spp. were found to produce ESBL. As an indicator of ESBL activity, the sensitivities of the five extended-spectrum beta-lactams were as follows: cefotaxime (100%), cefpodoxime (99.3%), ceftriaxone (98.6%), aztreonam (93%) and ceftazidime (57.7%) when interpreted using the National Committee for Clinical Laboratory Standards criteria. Their positive predictive values ranged from 67.8-83.8%. Both the inhibitor-potentiated disc diffusion test and the double-disc synergy test (at three inter-disc widths of 20, 25 and 30 mm) were capable of identifying all the ESBL-producers. However, at a single inter-disc width of 30 mm, the double-disc synergy test has limited sensitivity (83.8%). As a second test for confirming ESBL activity in strains with reduced susceptibility to beta-lactams, the inhibitor-potentiated disc diffusion test is therefore a simple and reliable option.     

耳大神经及腮腺筋膜解剖的再认识与腮腺切除手术的改良

目的：对耳大神经及腮腺筋膜解剖进行再认识，由此改良腮腺切除手术方法。方法：解剖成人尸体10侧，术中活体解剖20侧，对耳大神经和腮腺筋膜的解剖要素进行观察。根据观察结果进行改良腮腺切除术14例，即在腮腺筋膜表面翻瓣后，由前向后另翻腮腺筋膜瓣，切除腮腺后将筋膜瓣复位缝合，完整保留耳大神经和腮腺筋膜。结果：耳大神经在下颌角水平之上0-2cm依次分耳后、耳垂、耳前支，神经主干末段和分支起始段均分布于腮腺筋膜浅层表面，后者致密，其致密纤维包裹在神经周围。改良手术后2例（14．3％）发生轻度Frey’s综合征，无1例发生术区皮肤长期麻木、长期面瘫、涎瘘及肿瘤复发。结论：耳大神经各分支和腮腺筋膜具有不可代替的解剖生理功能，改良术式能将两者完好保留，显著降低术后并发症。     

Territorywide Study of Early Coronavirus Disease Outbreak,Hong Kong,China

Initial cases of coronavirus disease in Hong Kong were imported from mainland China. A dramatic increase in case numbers was seen in February 2020. Most case-patients had no recent travel history, suggesting the presence of transmission chains in the local community. We collected demographic, clinical, and epidemiologic data from 50 patients, who accounted for 53.8% of total reported case-patients as of February 28, 2020. We performed whole-genome sequencing to determine phylogenetic relationship and transmission dynamics of severe acute respiratory syndrome coronavirus 2 infections. By using phylogenetic analysis, we attributed the community outbreak to 2 lineages; 1 harbored a common mutation, Orf3a-G251V, and accounted for 88.0% of the cases in our study. The estimated time to the most recent common ancestor of local coronavirus disease outbreak was December 24, 2019, with an evolutionary rate of 3.04 × 10⁻³ substitutions/site/year. The reproduction number was 1.84, indicating ongoing community spread.     

Validation of low-cost models for minimal invasive surgery training of congenital diaphragmatic hernia and esophageal atresia

BackgroundMinimal invasive surgery (MIS) is increasingly used for the correction of congenital diaphragmatic hernia (CDH) and esophageal atresia (EA). It is important to master these complex procedures, preferably preclinically, to avoid complications. The aim of this study was to validate recently developed models to train these MIS procedures preclinically.MethodsTwo low cost, reproducible models (one for CDH and one for EA) were validated during several pediatric surgical conferences and training sessions (January 2017–December 2018), used in either the LaparoscopyBoxx or EoSim simulator. Participants used one or both models and completed a questionnaire regarding their opinion on realism (face validity) and didactic value (content validity), rated on a five-point-Likert scale.ResultsOf all 60 participants enrolled, 44 evaluated the EA model. All items were evaluated as significantly better than neutral, with means ranging from 3.7 to 4.1 (p < 0.001). The CDH model was evaluated by 48 participants. All items scored significantly better than neutral (means 3.5–3.9, p < 0.001), with exception of the haptics of the simulated diaphragm (mean 3.3, p = 0.054). Both models were considered a potent training tool (means 3.9).ConclusionThese readily available and low budget models are considered a valid and potent training tool by both experts and target group participants.Type of studyProspective study.Level of evidenceLevel II.     

Glove Permeation Tests Using Novel Microchemical Techniques for 2,4-Dichlorophenoxyacetic Acid (2,4-D) Derivatives

The aim was to assess the permeation of different herbicide emulsion concentrate formulations of 2,4-dichlorophenoxyacetic acid (2,4-D) as 60.8 and 83.5% butoxyethyl ester (BEE) and 46.8% dimethyl amine salt (DMAS) through four types of glove materials (lined unsupported nitrile, unlined unsupported butyl, Silver Shield laminate, and Viton). This entailed the development of new microchemical techniques to allow sensitive capillary gas chromatography/mass spectrometry (GC/MS) of the permeated herbicide. The 2,4-D DMAS was esterified to the methyl ester by boron trifluoride-methanol complex with 99.2 ± 3.7% efficiency using microwave heating to minimize reaction time and to process microsamples. The GC/MS detection limit was 5 ng/ml (ppb) of 2,4-D DMAS in the collection medium. The permeates from the ester formulations were analyzed directly for the ester above the detection limit of 9 ng/ml (ppb) BEE. The permeation investigations utilized the American Society for Testing Materials (ASTM)-type permeation cells with liquid collection media. The results showed that these gloves could provide at least 6 h protection for these formulations. Received: 8 July 1998/Accepted: 13 December 1998     

Safety and immunogenicity of combined diphtheria-tetanus-pertussis (whole cell and acellular)-Haemophilus influenzae-b conjugate vaccines administered to Indonesian children

A randomized double-blind trial was conducted to evaluate the safety and immunogenicity of vaccines comprised of diphtheria (D) and tetanus (T) toxoids combined with either a whole cell (P) or an acellular (aP) pertussis component and Haemophilus influenzae type b polyribosylphosphate (PRP) tetanus toxoid conjugate (PRP-T) in Indonesian infants. Three doses of either DTaP, DTaP-PRP-T, or DTP-PRP-T were administered to 930 infants approximately 2-3 months of age and at 2 month intervals thereafter. A booster dose of either DTP-PRP-T or DTaP-PRP-T was administered at 15-18 months of age. Both local and systemic reactions occurred at a significantly (p < 0.001-0.026) higher rate in the group that received whole cell pertussis vaccine versus groups which were immunized with aP containing vaccines. There was no significant difference (p > 0.05) in the rate of adverse events between groups immunized with DTaP or DTaP PRP T. One month after the third dose of vaccine, 99% of subjects had achieved > or =0.1 IU of anti-D and anti-T antibody per ml of serum. The geometric mean titer (GMT) to D was significantly (p < 0.001) higher in the group immunized with DTaP versus the other two groups whereas the anti-T GMT was significantly (p < 0.006) higher for the group immunized with DTP-PRP-T. Both the anti-pertussis toxin (PT) and anti-filamentous hemagglutinin (FHA) antibody levels were significantly (p < 0.001) higher in recipients of acellular versus whole cell pertussis vaccine. In contrast, the anti-B. pertussis agglutinating antibody response was significantly (p < 0.0001) higher in the group immunized with whole cell pertussis vaccine. The anti-PRP GMTs (microg antibody/ml) at 7 months were 0.096, 3.35 and 6.11 for groups immunized with DTaP, DTaP-PRP-T and DTP-PRP-T, respectively. The GMT for those immunized with DTP-PRP-T was significantly (p < 0.001) higher compared to recipients of DTaP-PRP-T. The percent of children who attained > or =0.15 or > or =1 microg/ml after immunization was 18 and 2% for the DTaP group, 93 and 76% for the DTaP-PRP-T group and 97 and 88% for the DTP-PRP-T group. At the > or =1 microg/ml level the difference between the DTaP-PRP0-T and DTP-PRP-T groups was significant (p < 0.01). Children immunized with either DTaP, DTaP-PRP-T, or DTP-PRP-T were reimmunized with DTaP-PRP-T whereas a portion of children immunized with DTP PRP T where also boosted with this vaccine at 15-18 months of age. There was a vigorous anamnestic response to the D and T components with all children possessing > or =0.1 IU/ml. There was also a substantial increase in anti-PT, anti-FHA and B. pertussis agglutinating antibodies. The poorest anti-PT response was seen among children receiving DTP-PRP-T for both primary and reimmunization while the highest agglutinating antibody response followed receipt of 4 doses of DTP-PRP-T. Greater than 80% of children immunized with either DTP PRP T or DTaP-PRP-T possessed > or =0.15 microg/ml before boosting versus 38% for those vaccinated with DTaP (p < 0.001). Primary immunization with DTP-PRP-T resulted in a significantly (p < 0.05) higher percentage (72%) maintaining > or =1 microg/ml compared to those immunized with DTaP-PRP-T (46%). Prior to reimmunization, the anti-PRP GMT was significantly (p < 0.005) higher for children immunized with 3 doses of DTP-PRP-T versus DTaP-PRP-T. Subsequent to reimmunization, > or =95% of subjects attained > or =1 microg/ml.