[Epidemiological characteristics and analysis of related infection risk factors for influenza in Anhui Province from 2013 to 2021]

Objective: Analysis of the characteristics of influenza epidemic in Anhui Province and quantification of the impact of different factors on influenza occurrence, providing scientific basis for better influenza prevention and control. Methods: Descriptive analysis and factor analysis were conducted on influenza-like illness (ILI) cases and RT-PCR results in Anhui Province from 2013 to 2021 using data from China's Influenza Monitoring Information System. Results: The percentage of influenza-like illness (ILI%) of sentinel hospitals in Anhui Province from April 1, 2013 to March 31, 2021 was 3.80% (1 209 142/31 779 987), showing an overall increasing trend, with a relatively high proportion in 2017-2018 at 4.30% (191 148/4 448 211). The proportion of ILI cases in infants and young children aged 0-4 years was a relatively high at 54.14% (654 676/1 209 142), and the highest ILI% was observed in Fuyang City, Anhui Province (6.25%, 236 863/3 788 863). Laboratory monitoring results showed that the positive rate of ILI cases in sentinel hospitals in 8 influenza monitoring years was 16.38% (34 868/212 912), showing an increasing trend year by year, with a relatively proportion in 2017-2018 at 26.19% (6 936/26 488). The detection rate of school-age children aged 5-14 years was a relativelyhigh at 28.81% (13 869/48 144), and the positive rate was a relatively high in Wuhu City among the 16 cities, reaching 22.01% (2 693/122 237). Influenza activity showed a single peak in winter-spring and alternating double peaks in winter-spring and summer, with different subtypes alternating, and A (H3N2) was the dominant subtype in summer. The results of a multiple logistic regression model showed that the positive rate was higher in 2017-2018, among children aged 5-14 years, in winter, and in southern Anhui. Conclusions: Influenza epidemic in Anhui Province has a clear seasonal pattern, and the ILI% and detection rate have shown an upward trend from 2013 to 2021. Therefore, it is suggested to ensure vaccine supply before the winter-spring influenza season arrives, and to strengthen vaccine uptake and health education to avoid the risk of infection during the peak period of influenza.

[A two-stitch continuous suture method for single-lumen ileostomy]

Objective: To explore the value of a two-stitch continuous suture in single- lumen ileostomy. Methods: This was a retrospective cohort study. Data for 98 patients who underwent single-lumen enterostomy were retrospectively collected between 1 January 2021 and 1 May 2022 at Zhujiang Hospital of Southern Medical University. All patients met the indications for prophylactic single-lumen ileostomy. Those older than 80 years of age, with complex underlying diseases, extremely poor systemic conditions who could not tolerate surgery, poor blood supply at the end of the bowel, and severe edema or severe infection at the end of the bowel were excluded. Among the included patients, patients who underwent surgery before 1 October 2021 underwent ileostomy with interrupted suture (control group, n=60), and patients operated on and after 1 October 2021 routinely underwent two-stitch continuous suture ileostomy (two-stitch stoma group, n=38). Two-stitch continuous suture ileostomy is performed as follows: the first continuous suture is used to suture the intestinal seromuscular layer, peritoneum, posterior sheath, and anterior sheath from deep to superficial layers. The bowel wall is then opened. The second continuous suture is used to suture the full thickness of the bowel and the skin. The differences in postoperative ostomy-related complications and operation time were compared between the groups. Results: There were no significant differences in baseline data between the groups (all, P>0.05). The operative time in the two-stitch stoma group was shorter than that of the control group (16.6±2.2 minutes vs. 25.1±2.4 minutes, respectively; t=-17.874;P<0.001). The incidences of mucocutaneous separation, dermatitis, and stoma rebound in the two-stitch stoma group were lower than those of the control group [5.3% (2/38) vs. 31.7% (19/60), χ²=9.633, P=0.002;5.3% (2/38) vs. 28.3% (17/60), χ²=7.923, P=0.005; and 2.6% (1/38) vs. 18.3% (11/60), P=0.026, respectively], while the incidences of parastomal hernia and stoma prolapse, and the postoperative visual analog scale scores in the two groups were similar (all P>0.05). Conclusion: Compared with traditional single-lumen ileostomy, two-stitch continuous suture ileostomy has the advantages of short operation time, simplicity, esthetic appearance of the stoma, and a significant reduction in the postoperative complications associated with ileostomy.

MeDBA: the Metalloenzyme Data Bank and Analysis platform

Metalloenzymes are attractive research targets in fields of chemistry, biology, and medicine. Given that metalloenzymes can manifest conservation of metal-coordination and ligand binding modes, the excavation and expansion of metalloenzyme-specific knowledge is of interest in bridging metalloenzyme-related fields. Building on our previous metalloenzyme-ligand association database, MeLAD, we have expanded the scope of metalloenzyme-specific knowledge and services, by forming a versatile platform, termed the Metalloenzyme Data Bank and Analysis (MeDBA). The MeDBA provides: (i) manual curation of metalloenzymes into different categories, that this M-I, M-II and M-III; (ii) comprehensive information on metalloenzyme activities, expression profiles, family and disease links; (iii) structural information on metalloenzymes, in particular metal binding modes; (iv) metalloenzyme substrates and bioactive molecules acting on metalloenzymes; (v) excavated metal-binding pharmacophores and (vi) analysis tools for structure/metal active site comparison and metalloenzyme profiling. The MeDBA is freely available at https://medba.ddtmlab.org.

[Responses of soil moisture at different slope positions to rainfall in dry-hot valley]

The study of short-term dynamics of soil moisture in the dry-hot valley area during rainfall process will help identify soil hydrological function. In this study, we analyzed the short-term responses of soil moisture to rainfall in Huajiang dry-hot valley of Guizhou, using in-situ monitoring method to yield high-frequency soil moisture monitoring data of different slope positions. The results showed that, during the whole monitoring period, soil moisture at each layer was at a moderate variation level (15.2%≤coefficient of variation CV≤29.7%), for both upper slope and middle slope. The fluctuation range of soil moisture of the upper slope (CV=21.1%) was greater than that of the middle slope (CV=19.1%), and that of the 0-5 cm soil layer (CV=26.2%) was greater than 20-40 cm layer (CV=16.5%). Compared with the middle slope, soil moisture of the upper slope had a faster response to rainfall. The supplement amount of rainfall was bigger and the supplement speed of rainfall was faster at the upper slope than that at the middle slope. The difference between the supplement speed and the depletion speed of soil moisture of the upper slope (2.3%·h^-1) was greater than that of the middle slope (1.8%·h^-1). With the increase of soil depth, the responses of soil moisture to rainfall in subsoil layer was earlier or synchronous with that in topsoil layer. When the supplement amount of soil moisture decreased and the supplement speed slowed down, the depletion speed slowed down. Compared with the middle slope, soil at the upper slope had greater water infiltration capacity and better water retention capacity. The responses of soil moisture to rainfall in dry-hot valley were influenced by micro-environment and microclimate, and the rapid recharge of dominant flow at rock-soil interface accelerated the response speed of subsoil moisture to rainfall, which made the slopes in this area easier to form mixed runoff generation mechanism.

Targeting Metalloenzymes by Boron-Containing Metal-Binding Pharmacophores

Metalloenzymes have critical roles in a wide range of biological processes and are directly involved in many human diseases; hence, they are considered as important targets for therapeutic intervention. The specific characteristics of metal ion(s)-containing active sites make exploitation of metal-binding pharmacophores (MBPs) critical to inhibitor development targeting metalloenzymes. This Perspective focuses on boron-containing MBPs, which display unique binding modes with metalloenzyme active sites, particularly via mimicking native substrates or tetrahedral transition states. The design concepts regarding boron-containing MBPs are highlighted through the case analyses on five distinct classes of clinically relevant nucleophilic metalloenzymes from medicinal chemistry perspectives. The challenges (e.g., selectivity) faced by some boron-containing MBPs and possible strategies (e.g., bioisosteres) for metalloenzyme inhibitor transformation are also discussed.

[Genotyping analysis of norovirus infectious diarrhea clusters in Songjiang district, Shanghai from 2017 to 2019]

Objective: We aimed to analyze the the genotyping of norovirus infectious diarrhea epidemic in Songjiang district, Shanghai, and explored the experience in handling the epidemic to provide a scientific basis for formulating prevention and treatment strategies. Methods: The epidemiological data and related samples of 69 outbreaks of infectious diarrhea caused by norovirus was collected from 2017 to 2019 in Songjiang district, Shanghai. Sequencing and type identification were performed by the method of gene sequencing for the junction region of Norovirus ORF1 and ORF2. Results: From 2017 to 2019, 69 outbreaks of norovirus infections diarrhea were reported in Songjiang district, Shanghai. A total of 1 767 samples were tested, including 619 case samples (positive rate 19.9%), 343 practitioner samples (positive rate 1.1%), 505 environmental samples (positive rate 0.5%) and 300 food samples (not detected). 141 sequences were obtained, and the genotype analysis showed that the genotype that mainly caused infectious diarrhea in 2017 and 2018 was GII.P16-GII.2 (50.98%, 26/51). In 2019, the genotypes that mainly caused infectious diarrhea were GII.P16-GII.2 (13.73%, 7/51) and GII.Pe-GII.4 (9.80%, 5/51). Conclusion: The main genotype of the 69 outbreaks of nororirus infectious diarrhea epidemic in Songjiang district, Shanghai from 2017 to 2019 was GII.P16-GII.2, which showed obvious peaks in spring, autumn and winter. There were more infections in kindergartens and schools. The surveillance of norovirus infection should be strengthened.

Design and enantioselective synthesis of 3-(α-acrylic acid) benzoxaboroles to combat carbapenemase resistance

Chiral 3-substituted benzoxaboroles were designed as carbapenemase inhibitors and efficiently synthesised via asymmetric Morita-Baylis-Hillman reaction. Some of the benzoxaboroles were potent inhibitors of clinically relevant carbapenemases and restored the activity of meropenem in bacteria harbouring these enzymes. Crystallographic analyses validate the proposed mechanism of binding to carbapenemases, i.e. in a manner relating to their antibiotic substrates. The results illustrate how combining a structure-based design approach with asymmetric catalysis can efficiently lead to potent β-lactamase inhibitors and provide a starting point to develop drugs combatting carbapenemases.

X-ray Structure-Guided Discovery of a Potent, Orally Bioavailable, Dual Human Indoleamine/Tryptophan 2,3-Dioxygenase (hIDO/hTDO) Inhibitor That Shows Activity in a Mouse Model of Parkinson's Disease

Human indoleamine 2,3-dioxygenase 1 (hIDO1) and tryptophan 2,3-dioxygenase (hTDO) have been closely linked to the pathogenesis of Parkinson's disease (PD); nevertheless, development of dual hIDO1 and hTDO inhibitors to evaluate their potential efficacy against PD is still lacking. Here, we report biochemical, biophysical, and computational analyses revealing that 1H-indazole-4-amines inhibit both hIDO1 and hTDO by a mechanism involving direct coordination with the heme ferrous and ferric states. Crystal structure-guided optimization led to 23, which manifested IC50 values of 0.64 and 0.04 μM to hIDO1 and hTDO, respectively, and had good pharmacokinetic properties and brain penetration in mice. 23 showed efficacy against the 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine-induced mouse motor coordination deficits, comparable to Madopar, an anti-PD medicine. Further studies revealed that different from Madopar, 23 likely has specific anti-PD mechanisms involving lowering IDO1 expression, alleviating dopaminergic neurodegeneration, reducing inflammatory cytokines and quinolinic acid in mouse brain, and increasing kynurenic acid in mouse blood.

[Clinical study on early loading restoration of superhydrophilic implants]

Objective: To study the clinical effect of early loading restoration a superhydrophilic implant after 1 year, so as to provide reference evidence for clinical practice. Methods: A total of 41 patients with dental defects, including 20 males and 21 females [age (52.3±13.1) years old], were enrolled in the Department of VIP, Hangzhou Dental Hospital (Pinghai Hospital) from July 2017 to January 2019. A total of 74 superhydrophilic implants were implanted, including 27 maxillary implants and 47 mandiolar implants. All patients without bone augmentation or soft tissue transplantation, the maxilla was taken impression 4 weeks after implant implantation, with 6 weeks of loading, the mandible was taken impression 2 weeks after implant implantation, with 4 weeks of loading. The stability of the implant was measured by resonance frequency analyzer before implant implantation, impression and loading. Periapical radiograph were taken immediately after mold removal, immediately after loading and reexamination 1 year after loading, to measure and record the changes in the bone level of the mesial and distal margins of the implant. Results: No biological complications occurred in all implants before loading restoration, and the implant survival rate was 100%(74/74). In 2 cases, the implant stability quotient (ISQ) value of the implant at the mandibular site was lower than 65 at 2 weeks after surgery, and the restoration was delayed. The ISQ values of the other 72 implants at the time of implantation (75.22±4.32) were not significantly different from those at the time of modeling (75.13±4.23) (P>0.05), but the ISQ values at the moment of weight loading (76.46±3.73) were significantly higher than those at modeling (P<0.05). All the early loading implants were reviewed 1 year after early loading, and none of them were loose or fell off, and the implant survival rate was 100%(72/72). X-ray measurement and evaluation showed that after 1 year of early loading restoration, the mean marginal bone absorption of 72 implants was (0.18±0.06) mm, among which the mandibular was (0.17±0.06) mm and the maxillary was (0.19±0.06) mm, showing no statistical difference (P>0.05). After 1 year of early loading restoration, the mean marginal bone absorption of 72 implants was (0.17±0.05) mm, including (0.17±0.06) mm for mandibular and (0.16±0.05) mm for maxillary, showing no statistical difference (P>0.05). Conclusions: In the limited scope of this clinical study, it has been proved that early loading of superhydrophilic implant is a safe and feasible treatment scheme, and the bone resorption at the implant edge after long-term early loading restoration needs further follow-up study.

Complete chloroplast genome of adonis amurensis (ranunculaceae), an important cardiac folk medicinal plant in east asia

Adonis amurensis Regel et Radde is an important cardiac folk medicinal plant which endemic to Northeast Asia. We determined the first complete chloroplast genome of A. amurensis using genome skimming approach. The cp genome was 157,032 bp long, with a large single-copy region (LSC) of 86,218 bp and a small single-copy region (SSC) of 18,212 bp separated by a pair of inverted repeats (IRs) of 26,301 bp. It encodes 129 genes, including 84 protein-coding genes, 37 tRNA genes, and 8 ribosomal RNA genes. We also reconstructed the phylogeny of Adonideae and Isopyreae using maximum likelihood (ML) method, including our data and previously reported cp genomes of related taxa. The phylogenetic analysis indicated that A. amurensis is close related with Adonis sutchuenensis.

0691 Comparison Of Odds Ratio Product And Other Polysomnographic Metrics Among Responders And Non-responders To Upper Airway Stimulation Treatment Of Obstructive Sleep Apnea

Introduction

Upper airway stimulation (UAS) is a surgical method of treating obstructive sleep apnea (OSA). UAS involves an implantable neuro-stimulator that stimulates the hypoglossal nerve to protrude the tongue during sleep. OSA fails to improve in 22% of patients who receive UAS as defined by a &gt; 50% reduction in Apnea-Hypopnea Index (AHI) and an AHI &lt;20 events/hour. Light sleep may predict UAS failure in that it may limit the stimulus strength that can be applied. The odds ratio product (ORP) is a novel polysomnographic (PSG) metric of sleep depth. We hypothesized that ORP values prior to surgery will be higher (lighter sleep) in non-responders. Having markers that predict surgical success can help reduce unnecessary surgeries.

Methods

This is a retrospective cohort study of 126 patients (83 responders vs. 43 non-responders) who received UAS implantation for the treatment of OSA. PSG data was obtained from the Stimulation for Apnea Reduction (STAR) trial. Raw baseline PSG data were analyzed and ORP values calculated using Michele Sleep Scoring Software (Cerebra Medical, Winnipeg, CA). In addition, 13 PSG metrics that were considered possibly relevant to surgical outcome were calculated as an exploratory analysis. The measurements included: spindle density, spindle power, spindle frequency, alpha intrusion, Right/Left sleep depth correlation coefficient, respiratory duty cycle, respiratory flow limitation, and arousal intensity. Statistical Analysis: Comparisons between responders and non-responders used parametric t-tests for continuous data and chi-squared or Fisher’s exact tests for categorical data. Statistical significance was based on a Bonferroni-corrected p&lt;0.00357.

Results

Differences in ORP values and other PSG metrics between responders and non-responders were not statistically significant. Of all PSG metrics only differences in spindle density approached statistical significance (Responders = 2.33 spindles/minute vs Non-Responders = 1.39 spindles/minute, p=0.00360).

Conclusion

The findings suggest that differences in sleep depth and several other sleep characteristics do not play a significant role in determining response to UAS therapy.

Support

This project was supported by a Sleep Research Society Career Development Award #023-JP-19

Temperature and excitation wavelength dependence of circular and linear photogalvanic effect in a three dimensional topological insulator Bi2Se3

The circular (CPGE) and linear photogalvanic effect (LPGE) of a three-dimensional topological insulator Bi₂Se₃ thin film of seven quintuple layers excited by near-infrared (1064 nm) and mid-infrared (10.6 [Formula: see text]m) radiations have been investigated. The comparison of the CPGE current measured parallel and perpendicular to the incident plane, together with the comparison of the CPGE current under front and back illuminations, indicates that the CPGE under front illumination of 1064 nm light is dominated by the top surface states of the Bi₂Se₃ thin film. The CPGE current excited by 10.6 [Formula: see text]m light is about one order larger than that excited by 1064 nm light, which may be attributed to the smaller cancelation effect of the CPGE generated in the two-dimensional electron gas when excited by 10.6 [Formula: see text]m light. Under the excitation of 1064 nm light, the LPGE current is dominated by the component which shows an even parity of incident angles, while the LPGE current excited by 10.6 [Formula: see text]m light is mainly contributed by the component which is an odd parity of incident angles. Both of the CPGE and LPGE currents excited by 1064 nm decrease with increasing temperature, which may be owing to the decrease of the momentum relaxation time and the stronger electron-electron scattering with increasing temperature, respectively.

Complete chloroplast genome of Prunus pensylvanica and its implications for the phylogenetic position within Prunus sensu lato (Rosaceae)

Prunus pensylvanica is one of the two native cherry species of North America. We determined the first complete chloroplast genome of P. pensylvanica using genome-skimming approach. The cp genome was 157,953 bp long, with a large single-copy region (LSC) of 86,030 bp and a small single-copy region (SSC) of 19,135 bp separated by a pair of inverted repeats (IRs) of 26,394 bp. It encodes 129 genes, including 84 protein-coding genes, 37 tRNA genes, and 8 ribosomal RNA genes. We also reconstructed the phylogeny of Prunus sensu lato using maximum likelihood (ML) method, including our data and previously reported cp genomes of related taxa. The phylogenetic analysis indicated that P. pensylvanica is closely related to P. emarginata.

[Analysis of clinical characteristics of necrotizing enterocolitis in term infants]

OBJECTIVE

To investigate the characteristics and outcomes of necrotizing enterocolitis (NEC) in Chinese term infants population.

METHODS

A national neonatal necrotizing enterocolitis network was established. Neonates as having necrotizing enterocolitis with gestation age ≥37 weeks were identified if they met the accepted diagnostic criterion during the study period from Jan 1(st) 2011 to Dec 31(st) 2011. The data of maternal and neonates' characteristics, the comorbidities, the clinical interventions prior to NEC, the clinical courses and radiology results, the medical and surgical treatment and the outcomes were collected. SPSS 19.0 software was used to do statistic analysis. Logistic-regression models were used to analyze the risk factors for death in infants with NEC, odds ratio (OR) and 95% confidence interval (CI) were calculated.

RESULTS

There were 231 067 newborn infants, 164 307 of them were term infants, admitted to 95 hospitals in main land China. There were 718 term infants were diagnosed as necrotizing enterocolitis with the incidence of 0.44%. There were 294 term infants cases identified as ≥stage 2 necrotizing enterocolitis for the analysis, including 193 cases of stage 2 and 101 cases of stage 3.The mean gestation age was (39.0±1.3) weeks, and the mean birth weight was(3 087.4±548.3)g. The percentage of small for gestation age was 20.4%. The onset age of NEC was 5 (2-11)d. The percentage of cases received breast milk feeding was 23.7%. The most common comorbidities were sepsis (9.5%, 28/294), asphyxia (9.5%, 28/294), pneumonia (7.8%, 23/294) and congenital megacolon (7.5%, 22/294). The bowel perforation rate was 13.9%. The rate of cases who received surgical treatment was 25.2%(76.6% small intestinal necrosis and 65.8% small intestinal perforation). The mortality rate was 28.9%(the mortality rate were 20.7% and 44.6% in stage 2 and stage 3 NEC, respectively). Noninvasive continuous positive airway pressure treatment for NEC (OR=5.278, 95% CI: 2.058-13.533, P<0.01) and NEC staging 3 (OR=3.156, 95% CI: 1.766-5.642, P<0.01) were statistically significantly associated with mortality of NEC.

CONCLUSIONS

The term infants with necrotizing enterocolitis usually have the underlying comorbidities. The breastmilk feeding rate is low. Necrotizing enterocolitis remains high mortality in term neonates in Chinese neonatal units. Noninvasive continuous positive airway pressure treatment for NEC is statistically significantly associated with mortality of NEC.

[Digital imaging fiber optic transillumination (DIFOTI) method for determining the depth of cavity]

OBJECTIVE

To analyze the accuracy of the digital imaging fiber optic transillumination (DIFOTI) on diagnosis of caries lesions depth using DIAGNOcam system.

METHODS

This experiment adopted self-matching design. Seventy-four extracted teeth (molar: sixty-six, premolar: eight) with one caries lesions in proximity which were not damaged in surface marginal ridge were selected. Dental calculus and dental stains were removed from the extracted teeth for standby application. A sign was marked in the middle of the occlusal surface edge at the side of decay. Then the teeth were fixed in the standard model of dentition and cavities were adjacent with the sound tooth surface. Sticky wax was applied to seal the level of 2 mm beyond cemento-enamel junction (CEJ) in the direction of occlusion and interproximal space to imitate gingival margin and gingival papilla. The standard models of dentition was seated in imitation head mold. The lesions depth degree was looked into and checked with DIAGNOcam system. Besides, the pictures on the occlusal surfaces were recorded and saved. The sign above could be seen on the picture. The measuring tool in DIAGNOcam system was used to measure the depth of the caries from the sign (as starting point) to the deepest point of caries in the pictures and its length was recorded for a. The line a was lengthened to the contralateral edge of occlusal surface in the photo and the length was recorded for b. A line from the marked point on the occlusal surface edge of the extracted teeth was draw parallel to the line b on the corresponding photo and its length was recorded for c. The depth of the cavities on the projected images was recorded for d, and calculated d/a=c/b (digital optical fiber measured decay depth/caries damage depth of the image=actual tooth width/tooth width of the image), and d=c/b×a inferred. At last, the teeth were taken out from the standard model dentition. The decay of the tooth was removed completely. The actual depth of the cavity was recorded for D. The difference between d and D was recorded for Δd. The software of SPSS 20.0 was used to test the consistency of the results, and the MedCalc 14.8.1.0 software was used for Bland-Altman analysis.

RESULTS

The intraclass correlation coefficient (ICC) between d and D was 0.951 (ICC>75%), P=0.263. There was a function relationship y=0.23+0.91x between d(x) and D(y). Bland-Altman analysis method showed that the mean of Δd (Δdmean) was 0.05 mm, the standard deviation of Δd (ΔdSD)=0.308, and the 95% confidence interval was (-0.55 to 0.65). The amplitude of difference was clinically acceptable. So the consistency of the two measurement modes was high.

CONCLUSION

There was no significant difference between the depth of caries lesions checked with DIAGNOcam system and the depth of the actual cavity, and the consistency was very good. The vitro study suggests that the DIAGNOcam system may be used to assess the depth of caries cavity as a useful tool in diagnosis and treatment.

Effect of progranulin (PGRN) on the proliferation and senescence of cervical cancer cells

We investigated the effect of progranulin (PGRN) expression on the proliferation and senescence of cervical cancer cells. PGRN small interfering RNA (siRNA) was introduced into the SiHa and HeLa cell lines of human cervical carcinoma using liposome-mediated transfection. The expression levels of PGRN in each cell line after transfection of PGRN siRNA were detected by reverse transcription-polymerase chain reaction (RT-PCR). Senescence in the cell lines was detected using the β-galactosidase-staining test, and proliferation was detected by clone formation. The RT-PCR assay showed that the expression of PGRN in all of the cell lines transfected with PGRN siRNA markedly decreased. In the clone-forming test, compared with the control group, the colony-forming ability in all cell lines decreased significantly after transfection with PGRN siRNA. The β-galactosidase-staining experiments showed that the phenomenon of cell aging in the PGRN interference group was more obvious than in the control group. After the cervical cancer cells had been transfected with PGRN siRNA, cell senescence was accelerated and clone-forming ability was markedly reduced. This suggests that PGRN can promote the proliferation of the cervical cancer cell line; proliferation of cervical cancer cells is achieved by inhibiting their senescence.

[Identification of Bupleurum chinense and B. longiradiatum based on ITS2 barcode]

In this study, ITS2 barcode was used to identify Bupleurum chinense and B. longiradiatum. The ITS2 regions of 48 samples were amplified and sequenced. The sequences obtained above were aligned and the K2P distances were calculated. We used three methods, BLAST1, nearest distance and phylogenetic tree (NJ-tree), to test the identification ability. The results showed that the maximum intraspecific genetic distance of B. chinense was 0.013, and the minimum interspecific genetic distance between B. chinense and B. longiradiatum was 0.049. The NJ-tree can easily identify B. chinense and B. longiradiatum. Therefore, the ITS2 barcode is suitable to identify B. chinense and B. longiradiatum.

[Identification of cimicifugae rhizoma and its adulterants using ITS2 sequence]

In order to identify Cimicifugae Rhizoma from its adulterants and to ensure its safe use, the internal transcribed spacer 2 (ITS2) sequence of Cimicifugae Rhizoma and its adulterants were amplified and bidirectionally sequenced by DNA barcoding technology. Sequence assembly and consensus sequence generation were performed by the CodonCode Aligner V3.7.1. The genetic distances were computed by MEGA 5.0. Identification analyses were performed using neighbor-joining (NJ) methods. The length of ITS2 sequence of the three origin plants of Cimicifugae Rhizoma include Cimicifuga heracleifolia, C. foetida, C. dahurica was 217, 219 and 219 bp, respectively. Their intraspecific genetic distance was much lower than the interspecific genetic distance with their closely related species. The NJ tree of ITS2 indicated that the three origin plants of Cimicifugae Rhizoma formed a monophyletic clade, Cimicifugae Rhizoma and its adulterants could be distinguished clearly. The authors proposed that ITS2 sequence was suitable for the authentication of Cimicifugae Rhizoma and its adulterants.

Abstract P6-07-06: Primary prophylaxis of febrile neutropenia during adjuvant docetaxel and cyclophosphamide (TC) chemotherapy for breast cancer

Background: The combination of docetaxel and cyclophosphamide (TC) for adjuvant treatment of early stage breast cancer improves overall survival compared with doxorubicin and cyclophosphamide (AC) (Jones et al., 2006). Although cardiotoxicity is avoided with TC, the risk of febrile neutropenia (FN) is higher. For TC, reported rates of FN without prophylactic granulocyte colony-stimulating factor (G-CSF) range from 5% in the phase III trial to as high as 46% in retrospective chart reviews. G-CSF is not covered by our provincial cancer funding agency for primary prophylaxis of FN with TC chemotherapy, however it is often prescribed for patients with private insurance. Our aims were twofold: i) to determine the incidence of FN with TC chemotherapy with and without prophylactic G-CSF or antibiotics in two Ontario comprehensive cancer centres, and ii) to evaluate the cost-effectiveness of primary prophylaxis with G-CSF vs. antibiotics.

Methods: Patients who received adjuvant TC chemotherapy between January 1, 2008 and December 31, 2012 were identified through pharmacy databases. Electronic charts were retrospectively reviewed to extract patient characteristics, treatment details including G-CSF and antibiotic use, as well as incidence of FN and duration of hospitalization. A Markov model comparing primary G-CSF prophylaxis, primary antibiotic prophylaxis and secondary G-CSF prophylaxis was constructed to compare the cost-effectiveness of these strategies over a four cycle time horizon. Costs were based on resource utilization from this retrospective cohort and supplemented by the published literature, adjusted to 2012 Canadian dollars. The model took the perspective of the third party payer. Both one-way and probabilistic sensitivity analyses were performed.

Results: 340 patients were treated with TC over the study period. Of the 73 (21%) who did not receive any primary prophylaxis with G-CSF or antibiotics, 23 (32%) developed FN requiring hospitalization and treatment with intravenous antibiotics. However, only 2 of the 192 patients (1%; P &lt;0.0001) who received primary G-CSF prophylaxis (funded by the patient or a third party payer), and 6 of the 53 patients (11%; P &lt;0.01) who received primary antibiotic prophylaxis (97% receiving ciprofloxacin) developed FN. Age ≥65 was a significant risk factor for FN in the absence of G-CSF (56% vs. 25%, P = 0.02). The results of the cost-effectiveness analysis will be presented at the meeting.

Conclusions: The FN rate associated with TC chemotherapy without primary prophylaxis exceeds 30% but may be reduced with prophylactic antibiotics or G-CSF. Unless prophylactic antibiotics are substantially more cost-effective than prophylactic G-CSF for TC chemotherapy in a particular region or country, primary prophylactic G-CSF should be funded, given its greater effectiveness than antibiotics and the global need to minimize the emergence of antibiotic resistance.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P6-07-06.

Trichosanthes kirilowii: A New Host of Cucurbit mild mosaic virus in China

Chinese cucumber (Trichosanthes kirilowii Maxim.) is a type of perennial liana plant of the Cucurbitaceae family that is mainly distributed in East Asia and northern Australia. It is an important medicinal plant and commonly used in Chinese herbalism, where it is considered to be one of the 50 fundamental herbs (2). During the summer and autumn of 2012, T. kirilowii plants showing symptoms of mild mosaic on the upper leaves and bright yellow color on the lower leaves were observed in the Haidian district of Beijing, China. Recently similar symptoms induced by Cucurbit mild mosaic virus (CuMMV) on squash have been reported. CuMMV is a new member of the genus Fabavirus in the Comovirinae subfamily, discovered in China in 2006 (1). Total RNA was extracted from five leaf samples of independent plants and used for reverse transcription with an oligo (dT)₁₈ primer, followed by PCR with a pair of CuMMV virus-specific primers FaR₁3012F (5'-CGAGTGCGAGTTAGAAATTGGGATG-3') and FaR₁5783R (5'-TCACTTTGAGGTGATAAAACAATCC-3') to amplify a 2,772-bp fragment including RNA-dependent RNA polymerase (RdRp) coding region. The expected target fragment was obtained in all symptomatic plant samples but not from an asymptomatic plant. Nucleotide sequence comparison analysis showed that the virus isolated from T. kirilowii (GenBank Accession No. KC959843) had 95.33% nucleotide identity and 99.15% amino acid identity in the RdRp sequence with a CuMMV isolate from squash (GenBank Accession No. FJ194941) (1). In addition, symptomatic samples tested positive for CuMMV by Western blot using CuMMV small coat protein (SCP) specific polyclonal antibody (1). To our knowledge, this is the first report of T. kirilowii as natural host of CuMMV in China. The impact of CuMMV on T. kirilowii production remains to be determined; however, the extended host range for this virus suggests a potential threat of CuMMV to cucurbit crops in China. References: (1) S. W. Dong et al. Arch. Virol.157:597, 2012. (2) J. H. Hong et al. China Pharmacist 7:561, 2004.

Cerebral hyperperfusion syndrome after revascularization surgery in patients with moyamoya disease

Moyamoya disease (MMD) is a progressive occlusive disease of the distal internal carotid artery that is primarily treated by superficial temporal artery-middle cerebral artery (STA-MCA) bypass. Despite its effectiveness, several postoperative complications have been reported with STA-MCA bypass. Cerebral hyperperfusion syndrome (CHS) after STA-MCA has attracted considerable attention as a hemodynamics-related complication because more cases of CHS after STA-MCA bypass are reported in MMD than in non-MMD patients. The mechanisms underlying CHS after revascularization in MMD patients are poorly understood. This report presents a comprehensive review of the literature on CHS after revascularization in MMD patients, focusing on the pathogenesis, clinical features, imaging techniques, treatment, and prognosis of CHS. Impaired cerebrovascular autoregulation has been implicated in the pathogenesis of CHS, which is characterized by unilateral headache, face and eye pain, seizures, and focal neurological deficits secondary to cerebral edema, and intracranial hemorrhage. Imaging techniques, such as single photon emission computed tomography (SPECT), 3-T magnetic resonance imaging/angiography, and selective arterial spin-labeling magnetic resonance imaging, are valuable for identifying patients at risk for CHS. Treatment strategies include strict blood pressure control, intracranial hemorrhage prevention, and free oxygen radical scavenger administration. Most patients can achieve a satisfying prognosis after effective treatment.

Studies on interaction of cucurbit aphid-borne yellow virus proteins using yeast two-hybrid system and bimolecular fluorescence complementation

In this article, yeast two-hybrid system (YTHS) and bimolecular fluorescence complementation (BiFC) were used to analyze the interactions of cucurbit aphid-borne yellows virus (CABYV)-encoded proteins. P0, P1, P1-2, P3, P4, and P5 were tested by YTHS in all possible pairwise combinations, and only P3/P3 interaction was detected. Results obtained by BiFC further confirmed the self-interaction of P3, and the subcellular localization of reconstituted YFP fluorescence was observed mainly in nuclei of Nicotiana benthamiana leaf epidermal cells. Domains involved in P3/P3 self-interaction were analyzed by YTHS and BiFC using deletion mutants. The results showed that R domain (residues 1-61) in the N-terminus could self-interact, and it also interacted with the S domain (residues 62-199) in the C-terminus of P3. The present work would serve as a molecular basis for further characterization of CABYV proteins, and the regions involved in P3/P3 self-interaction could provide the clue for understanding the capsid assembly pathway of CABYV.

DNA barcoding provides distinction between Radix Astragali and its adulterants

Based on variable nuclear and/or organellar DNA sequences among vastly divergent species as well as morphologically indistinguishable species, DNA barcoding is widely applicable in species identification, biodiversity studies, forensic analyses, and authentication of medicinal plants. The roots of Astragalus membranaceus and A. membranaceus var. mongholica are commonly used as Radix Astragali in several Asian countries, including China, Japan, and Korea. However, in addition to the two species recorded in the Chinese Pharmacopoeia, there are twenty-three species from different genera including Astragalus, Oxytropis, Hedysarum, and Glycyrrhiza, which have been used as adulterants not only in trading markets but also by the herbal medicine industry. Therefore, a simple, reliable, and accurate classification method is important for distinguishing authentic Radix Astragali from its adulterants. In this study, we acquired data for 37 samples from four related genera within the family Fabaceae. Then we compared four candidate DNA barcoding markers using ITS, matK, rbcL, and coxI sequences from nuclear, chloroplast, and mitochondrial genomes, all commonly used for plants to identify genetic variations among genera, intraspecies, and interspecies. We observed higher divergences among genera and interspecies for ITS, which have the average Kimura 2-parameter distances of 4.5% and 14.1%, respectively, whereas matK was found to have sufficient divergence at the intraspecific level. Moreover, two indels detected in the matK sequence are useful for PCR studies in distinguishing Radix Astragali from its adulterants. This study suggests that the combined barcoding regions of ITS and matK are superior barcodes for Radix Astragali and further studies should focus on evaluating the applicability and accuracy of such combined markers for a wide range of traditional Chinese herbs.

Wuweizidilactones A–F: Novel Highly Oxygenated Nortriterpenoids with Unusual Skeletons Isolated fromSchisandra chinensis

A phytochemical study of secondary metabolites produced by Schisandra chinensis has led to the isolation of six novel highly oxygenated nortriterpenoids, wuweizidilactones A-F (1-6). Compounds 3-6 possess an unprecedented 3,4-seco-18(13-->14)-abeo-artane skeleton. Interestingly, structures 3-6 have a beta-oriented methyl group at the C-14 position. This structural feature corroborates the biogenetic pathway proposed for the formation of 18-norschiartane-type compounds 1 and 2. The structures of these novel metabolites were established on the basis of their detailed spectroscopic analysis. The structure of 1 was also confirmed by single-crystal X-ray diffraction analysis. For the first time, the absolute configuration of these nortriterpenoids was determined by using a modified Mosher method.

Anxiolytic-like activity of the mGLU2/3 receptor agonist LY354740 in the elevated plus maze test is disrupted in metabotropic glutamate receptor 2 and 3 knock-out mice

RATIONALE

(1S,2S,5R,6S)-2-Aminobicyclo[3.1.0]hexane-2,6-dicarboxylic acid (LY354740) is a potent and selective agonist for group II metabotropic glutamate (mGlu2 and mGlu3) receptors, with anxiolytic-like activity in animal and human models, and efficacy in anxiety patients. However, the lack of mGlu2 or mGlu3 receptor specific agonists has prevented in vivo characterization of individual functions of these two receptors in mediating the anxiolytic-like effects of LY354740.

OBJECTIVE

To utilize mGlu2 receptor and mGlu3 receptor knockout animals and the mGlu2/3 selective antagonist (2S,1'S,2'S)-2-(9-xanthylmethyl)-2-(2'-carboxycyclopropyl)glycine (LY341495) to further investigate the roles of mGlu2 and mGlu3 receptors in mediating the anxiolytic-like actions of LY354740 in a mouse model of anxiety [elevated plus maze (EPM) test].

METHODS

To confirm that mGlu2/3 receptors are responsible for anxiolytic-like activity in the EPM under these test conditions, mice were pretreated with LY341495 at 30 min prior to s.c. administered LY354740. Subsequently, saline vehicle or LY354740 was administered (s.c.) 30 min before the EPM testing in wild-type, mGlu2 receptor knockout, and mGlu3 receptor knockout mice.

RESULTS

LY354740 reduced in a dose-dependent manner anxiety-related behavior on the EPM in wild-type mice with a maximally effective dose of 10--20 mg/kg s.c. Pretreatment with LY341495 potently prevented the anxiolytic-like effects of LY354740 (20 mg/kg, s.c.) in mice. Although the mGlu2 receptor knockout and mGlu3 receptor knockout mice were grossly normal, the anxiolytic-like activity of LY354740 (20 mg/kg, s.c.) was not evident in either mGlu2 or mGlu3 receptor knockout mice, when compared to their wild-type controls.

CONCLUSIONS

The activation of both mGlu2 and mGlu3 receptors by LY354740 appears to be required for anxiolytic-like activity in the EPM test in mice. These studies serve as a foundation for additional studies on underlying circuits, brain structures, and receptor subtypes involved in the anxiolytic-like actions of mGlu receptor active agents, and the design of future drugs for anxiety disorders in humans.

Increased anxiety-related behavior in mice deficient for metabotropic glutamate 8 (mGlu8) receptor

Pre-synaptic metabotropic glutamate (mGlu) receptors modulate neuronal excitability by controlling glutamate and gamma-aminobutyric acid (GABA) release. The mGlu8 receptor is predominantly found in pre-synaptic terminals and its expression is highly restricted. To study the role of this receptor, mGlu8 receptor-deficient mice were generated. Here we report that naïve mGlu8 receptor-deficient mice showed increased anxiety-related behavior in the elevated plus maze in low illumination conditions (red light). Open arm avoidance and risk assessment behavior were both significantly increased in mutant mice. Increased stressfulness of the testing conditions abolished this behavioral difference. Fluorescent light or prior restraint stress decreased the open arm activity of wild-type mice, while the open arm activity of mutant mice was essentially unaffected, leading to similar values in both strains. The total number of arm entries or closed arm entries was not significantly different between strains, indicating that the lack of mGlu8 receptor does not affect locomotor activity. No gross behavioral changes, or changes in the function of the autonomic nervous system or somatomotor systems were observed in mutant mice. Moreover, no significant differences in seizure susceptibility were detected between strains. Our results suggest that mGlu8 receptor may play a role in responses to novel stressful environment.

Synthesis, characterization, and magnetic properties of carbon- and boron-oxide-encapsulated iron nanocapsules

Carbon- and boron-oxide-encapsulated iron nanocapsules have been synthesized by arc discharge in methane (CH4) and diborane (B2H6) atmospheres respectively. The characterization and magnetic properties of carbon- and boron-oxide-encapsulated iron nanocapsules [abbreviated as Fe(C) and Fe(B) respectively] were investigated and compared. The structure of the Fe(B) nanocapsules is different from that of the Fe(C) nanocapsules. The Fe(C) nanocapsules consist of a crystalline graphite shell and a core of alpha-Fe and/or Fe3C. The Fe(B) nanocapsules consist of an amorphous boron-oxide layer and a core of Fe(B) solid solution, alpha-Fe, gamma-Fe, FeB, and/or Fe3B phases. The saturation magnetizations of both the Fe(C) and the Fe(B) nanocapsules below 300 K decrease monotonically with increasing temperature. The coercivities of the Fe(C) and Fe(B) nanocapsules are almost 2 orders of magnitude higher than that of bulk Fe. The temperature dependence of magnetization at high temperatures indicates the existence of some phase transformations.

Acupuncture effects on reflex responses to mental stress in humans

In animal studies, acupuncture has been shown to be sympathoinhibitory, but it is unknown if acupuncture is sympathoinhibitory in humans. Nineteen healthy volunteers underwent mental stress testing pre- and postacupuncture. Muscle sympathetic nerve activity (MSNA), blood pressure, and heart rate during mental stress were compared pre- and postacupuncture. Control acupuncture consisted of acupuncture at nonacupoints and "no-needle" acupuncture. Acupuncture had no effect on resting MSNA, blood pressure, or heart rate. After real acupuncture, the increase in mean arterial pressure (pre- vs. postacupuncture 4.5 vs. 1.7 mmHg, P < 0.001), but not MSNA or heart rate, was blunted during mental stress. Similarly, following nonacupoint acupuncture, the increase in mean arterial pressure was blunted during mental stress (5.4 vs. 2.9 mmHg, P < 0.0003). No-needle acupuncture had no effect on these variables. In conclusion, acupuncture at traditional acupoints, nonacupoints, and no-needle acupuncture does not modulate baseline MSNA or MSNA responses to mental stress in normal humans. Acupuncture significantly attenuates the increase in blood pressure during mental stress. Needling nonacupoints, but not "no-needle" acupuncture, have a similar effect on blood pressure.

[Expression of single-chain Fv antibody for anti-beet necrotic yellow vein virus in Escherichia coli]

The heavy chains variable region gene (VH) of monoclonal antibody against beet necrotic yellow vein virus (BNYVV) was amplified from total DNA extracted from anti-BNYVV hybridoma cells by PCR. Sequencing showed that the VH belongs to mouse subgroup II(A) and contains 360 bp, which code one hundred and twenty amino acids. The VH and VL genes were inserted into a plasmid which contains a linker sequence for constructing scFv gene. The new vector named pTC scFv. The scFv was produced in Escherichia coli and appeared binding activity with BNYVV antigen by ELISA method.

Study on antimicrobial susceptibility of bacteria causing neonatal infections: a 12 year study (1987-1998)

OBJECTIVE

The method of Manual of Clinical Microbiology was used to identify bacteria. We investigated the epidemiological characteristics of bacterial agents and their antimicrobial susceptibility as empirical treatment for neonatal infections. Disk diffusion tests were also done for antimicrobial susceptibility.

RESULTS

From January 1987 to December 1998, 2,244 bacterial strains were isolated in our neonatal ward. The first three predominant species were Staphylococcus epidermidis (23.9%), Staphylococcus saprophyticus (19.9%) and Escherichia coli (12.6%) in group I (infections acquired outside of hospital). Escherichia coli, Klebsiella and Pseudomonas aeruginosa accounted for 18%, 15.2% and 12.6% respectively in group II (nosocomial infections). The sensitivity rates of those antimicrobials that are seldom used for newborns were found to be higher, while the resistant rates of the commonly used antimicrobial drugs have increased significantly. The resistant rates of bacterial isolate from group II to antimicrobial agents including penicillin and ampicillin were significantly higher than those isolated from group I (p<0.05)The sensitivity rate was 82.2% (717/833) by using amikacin only, when combined with penicillin, rose to 89%(741/833).

CONCLUSIONS

Gram-negative bacteria were mainly responsible for nosocomial infections of neonates in our hospital. Infections acquired outside the hospital were mainly caused by Gram-positive bacteria. Nosocomial pathogens produced drug resistance easily. Combination of amikacin and penicillin can be recommended as the initial antibiotics for treatment of neonatal infections.

[Genescan for STR analysis and genetic distribution in a population sample from Han, China]

Genetic distributions for nine STR loci and Amelogenin locus were determined in a Chinese Han population based on DNA sequencing. The databanks in Chinese Population were generated by using Genescan, genotype and genetic distribution analysis. Allele frequency distribution was determined for 10 loci, such as D3S1358, VWA, FGA, Amelogenin, THO1, TPOX, CSF1PO, D5S818, D13S317 and D7S820. The results show significant differences between ethnic groups (African-American, US-Caucasian and Chinese Han) in the pattern of distribution as well as in the related frequency of the most common alleles of their STR loci. The probabilities of identity values for the population described in this section are 2.79 x 10(-10) (U.S-Caucasian), 1.23 x 10(-10) (African-American) and 0.5 x 10(-10) (Chinese Han). The results show the probability of Paternity Exclusion (PPE) values of 0.9998 (Chinese Han), 0.9996 (African-American) and 0.9994 (U.S-Caucasian). These results suggested that the nine STR loci and the Amelogenin locus are very useful for human identification, such as analyzing forensis casework, establishing DNA databanks, processing paternity test, evaluation linkage genetics, studying gene natural resources and monitoring bone marrow transplants.

Oncogenes and angiogenesis: signaling three-dimensional tumor growth

Three-dimensional tumor growth is dependent on the perpetual recruitment of host blood vessels to the tumor site. This recruitment process (mainly via angiogenesis) is thought to be triggered, at least in part, by the very same set of genetic alterations (activated oncogenes, inactivated/lost tumor suppressor genes) as those responsible for other aspects of malignant transformation (e.g., aberrant mitogenesis, resistance to apoptosis). Potent oncogenes are able to deregulate expression of both angiogenesis stimulators and inhibitors in cancer cells. For example, mutant ras expression is associated with increased production of vascular endothelial growth factor (VEGF) and downregulation of thrombospondin-1 (TSP-1). Upregulation of VEGF and angiogenesis can also be induced by constitutive activation of other oncogenic proteins (e.g., EGFR, Raf, MEK, PI3K) acting at various levels on the Ras signaling pathway. The mode and the magnitude of such proangiogenic influences can be significantly modified by cell type (fibroblastic or epithelial origin), epigenetic factors (hypoxia, changes in cell density), and/or presence of additional genetic lesions (e.g., preceding loss of p16 or p53 tumor suppressor genes). Activated oncogenes (e.g., ras, src, HER-2) induce co-expression of angiogenic properties concomitantly with several highly selectable traits (increased mitogenesis, resistance to apoptosis), a circumstance that may accelerate selection of the angiogenic phenotype at the cell population level. On the other hand oncogene-induced reduction in growth requirements may also endow tumor cells with a diminished (albeit not abrogated) dependence on (close) proximity to blood vessels, i.e., with reduced vascular dependence. Thus, oncogenes can impact several interconnected aspects of cellular growth, survival, and angiogenesis. Experimental evidence suggests that, in principle, many of these properties (including angiogenesis) can be simultaneously suppressed (and tumor stasis or regression induced) by effective use of the specific oncogene antagonists and signal transduction inhibitors.

High-frequency color flow imaging of the microcirculation

The extension of ultrasound (US) color flow imaging (CFI) techniques to high frequencies (> 20 MHz) has the potential to provide valuable noninvasive tools for scientific and clinical investigations of blood flow in the microcirculation. We describe the development of a slow-scan CFI system operating in the 20-100-MHz range that has been optimized to image the microcirculation. The apparatus has incorporated elements of a previously reported pulsed-wave Doppler system and is capable of operating in either CFI or pulsed-wave mode. The performance of the CFI system was evaluated at a center frequency of 50 MHz using two PVDF transducers with -6-dB beam widths of 43 and 60 microm. The -6 dB-axial resolutions were estimated to be 66 and 72 microm, respectively. In vivo validation experiments conducted using the murine ear model demonstrated the detection of flow in vessels down to 15-20 microm in diameter with flow velocities on the order of mm per s. Further experiments examining experimental murine tumors confirmed the successful detection of flow in the tumor microcirculation.

Binding of immobilized fibronectin by biliary drain isolates

Occlusion of biliary stents, as the result of bacterial adhesion and colonization onto biliary stents, still remains a major problem. Biliary proteins, such as fibronectin (Fn) and vitronectin (Vn), have been presumed to be involved in the process of bacterial adhesion to biliary biomaterial. In the present study, Fn binding by 5 strains of E. coli isolated from biliary drains or from bile was studied. All strains did not bind detectable amounts of soluble Fn but bound to immobilized plasma Fn. Adhesion of four strains of E. coli to ovalbumin was reduced by periodate treatment of ovalbumin, but adhesion to Fn was unaffected. Adhesion was inhibited by mannose-containing saccharides, trypsin treatment of the protein, and protease treatment of the bacterial cells. Autoradiography showed that components of cell extracts from three E. coli strains bind 125I-Fn but not a 150 kD Fn fragment. The findings indicate that the adhesion of these bacteria to Fn is a protein-protein interaction, inhibited by D-mannose, and possibly mediated by fimbrial components.

Fibronectin binding by Propionibacterium acnes

Strains of Propionibacterium acnes, isolated from different kinds of orthopaedic and biomaterial-associated infections and from skin flora were shown to express binding of soluble as well as immobilized fibronectin. Among these 7 strains isolated from orthopaedic infections, 2 from breast prostheses, and 9 skin isolates, 2, 2, and 5 strains respectively bound immobilized fibronectin. The fibronectin binding was sensitive to protease and heat treatment, and was inhibited by a cell surface extract from one of the binding strains. In SDS-PAGE and autoradiography of cell surface extracts, a band corresponding to a MW of about 80 kD reacted with fibronectin and the 150 kD fragment of fibronectin. Binding to fibronectin and the 150 kD fragment of fibronectin could be inhibited with heparin. We thus present a first Fn binding protein of P. acnes, a surface exposed protein of 80 kD. None of the strains bound soluble collagen, and only one strain expressed weak binding of vitronectin and bone sialoprotein II.

Fibronectin exposes different domains after adsorption to a heparinized and an unheparinized poly(vinyl chloride) surface

The adsorption of fibronectin to poly(vinyl chloride) catheters with end-point attached (EPA) heparin and tridodecylmethylammonium chloride-heparinized poly(vinyl chloride) was compared to that of unheparinized poly(vinyl chloride) using antibodies directed against four different domains of the protein. After perfusion of human plasma on the EPA-heparinized surface, the exposure of the N-terminal 29-kD fragment increased during the first 5 h of perfusion. Also, the exposure of the 30-kD gelatin-binding and 65-kD cell-binding fragments increased with time, but at a lower level. On the unheparinized catheter, low levels of antibodies bound to the different domains, and the binding showed little variation during the 5 h of plasma perfusion, indicating that the fibronectin molecule does not change configuration to a significant extent on this surface after the initial adsorption. When the EPA-heparinized surface was preabsorbed with human fibrinogen before incubation with fibronectin, significantly less of the 29-kD (fibrin-binding) domain was exposed, and the 30-kD domain was not exposed. Exposure of the 31- and 65-kD domains increased after preadsorption of fibrinogen to the surface. Since fibronectin has heparin-binding domains, it adsorbs differently to a heparinized versus an unheparinized surface. This will influence subsequent binding of other proteins to the surface, as well as potential binding of microbes. The use of antibodies to defined domains of the fibronectin molecule provides a powerful tool in studies of configurational changes of fibronectin after adsorption to different surfaces.

Protein adsorption and bacterial adhesion to biliary stent materials

Four biliary stents inserted for relief of jaundice in patients with biliary obstruction due to carcinoma of pancreatic head were examined for the adsorption of biliary proteins and bacterial colonization. Fibronectin and vitronectin (S-protein) were found to be the two main proteins adsorbed on the inner surface of the stents. Biliary isolates included Escherichia coli, Enterococcus faecalis, and Candida albicans. In vitro studies were performed to clarify the kinetics of biliary protein and bacterial adhesion. Biliary drains of polytetrafluorethylene, polyethylene, polyurethane, and rubber were placed in a flow cell and perfused with human bile at 37% C for 24 hr. The materials were subjected to either detection of adsorbed biliary proteins or perfusion with 3 H-labeled E. coli cells (1 X 10 6 cfu/ml). The results show that the adsorbed biliary proteins were detectable on the surface of biliary stents and able to enhance bacterial adhesion to the surface in the first 24 hrs after the exposure of stent materials to bile, and that both the adsorption of biliary proteins and the adhesion of bacterial cells were material- and strain-dependent. Furthermore, there was a clear correlation between the amount of adsorbed fibronectin and the number of adherent bacteria. The results indicate that, in the clinical situation, biliary proteins may be adsorbed on the surface of inserted stents within a short time after insertion, and some of them may be used by bacterial cells as receptors for adhesion to the surface, and thus involved in the process of bacterial adhesion.

A bacteriologic and scanning electron microscope study after implantation of foreign bodies in the biliary tract in rats

BACKGROUND

Bacterial adherence to the stent surfaces, concomitant colonization, and possible stent blockage are the main complications after the use of biliary stents. The present study was assigned to investigate bacteriologic and morphologic changes in the biliary tract after the implantation of biliary drain materials.

METHODS

Rubber and silicone pieces with a surface area of 1 cm2 were implanted into the biliary tract in rats after temporary obstruction of the common bile duct by the use of a mini-occluder. The animals were killed at 4, 8 and 14 weeks, respectively, after implantation, and the implants were retrieved, cultured, and examined by scanning electron microscopy (SEM). Bacterial culture and SEM were also performed on tissue samples obtained from the mucosal surface of the biliary tract.

RESULTS

Bacterial colonization and biofilm formation were found on the surfaces of the implanted materials and on the mucosal surface of the biliary tract in animals with implants but not on the biliary tract mucosa in rats without implants.

CONCLUSION

Foreign bodies implanted in the biliary tract facilitate bacterial adherence not only to the surface of the implants but also to the mucosal surface in the biliary tract.

Fibronectin on the surface of biliary drain materials--a role in bacterial adherence

The present study deals with the demonstration of deposited fibronectin (Fn) on the surfaces of implanted biliary drain materials and the role of deposited Fn in promotion of bacterial adherence. Rubber pieces that had been implanted in the biliary tracts of rats for 4 weeks were retrieved and the following approaches employed for further investigations: (1) adherence of [methyl-3H]thymidine-labeled Escherichia coli to implanted and unimplanted rubber pieces; (2) blocking the adherence of radiolabeled bacteria with anti-Fn antibodies; (3) detection of deposited Fn by 125I-labeled anti-Fn IgG; and (4) immunoblotting of the surface eluate from implanted rubber pieces. The results show that in the presence of serum, plasma, or bile, the number of E. coli cells adherent to implanted rubber pieces was 10 times higher than that adherent to the unimplanted pieces (P < 0.001) and that the adherence was reduced by pretreatment of implanted pieces with anti-Fn antibodies. Furthermore, the implanted pieces appeared to have a high affinity for 125I-labeled rabbit anti-Fn IgG rather than the 125I-IgG without anti-Fn fraction. Fn was also found in the surface eluate of implanted pieces by immunoblotting of the eluate. The results in the present study suggest that Fn may be involved in implant-associated infections in the biliary tract.

Experimental foreign-body infection in the biliary tract in rats

BACKGROUND

Biomaterials used for biliary drainage may potentially result in biomaterial-associated infections.

METHODS

Foreign-body infection in the biliary tract was investigated in rats. Rubber drain pieces were implanted in the biliary tract in rats for 1-4 weeks, followed by challenges with 10(2) to 10(4) colony-forming units (cfu) Escherichia coli injected into the common bile duct. The rate of infection was calculated, the bacterial growth in the biliary tract was observed over 72 h after challenges, and the opsonic activity in bile and in sera was assessed.

RESULTS

In the group with drain material, inocula as small as 10(2) cfu produced persisting infection in the common bile duct in 90% of animals, whereas the same number of E. coli infected only 30% of rats in the control and sham implantation groups (p < 0.01, chi-square test). Complement-mediated opsonic activity in bile of animals with implanted drain pieces gradually decreased with time, whereas opsonic activity in sera from the same animals remained unchanged.

CONCLUSIONS

Implants in the biliary tract impair local host defense, resulting in an increased susceptibility to microbial infection.

Promotion of Escherichia coli adherence to rubber slices by adsorbed fibronectin

Biomaterial-associated infections are a problem in the use of endoprosthetic materials in the palliative treatment of malignant obstructive jaundice. Fibronectin has been reported to mediate adherence of bacteria to host tissue and biomaterials. Adsorption of fibronectin to rubber--representing material used for biliary drainage--and subsequent adherence of Escherichia coli strain PSS1 and E. coli strain NG7C (which binds to immobilised fibronectin) were investigated. Quantitative adsorption of fibronectin to rubber slices was studied with 125I-labelled, purified human plasma fibronectin. In buffer solutions, fibronectin showed a high affinity for rubber slices. Adherence of the E. coli strains to uncoated rubber slices was similar and was significantly inhibited by the presence of plasma components and bile. Adherence of E. coli PSS1 to fibronectin-coated slices was poor. In contrast, E. coli NG7C adhered efficiently to coated slices in proportion to the amount of adsorbed fibronectin; adherence was not reduced by the presence of albumin or bile, or the fibronectin-binding ligands gelatin, heparin and fibrinogen. However, pre-digestion of coated slices with trypsin significantly reduced adherence.

Reduction of E. coli adherence to rubber slices treated with phospholipids

The present study aimed at modifying the surface of biliary drain material to reduce bacterial adherence. The adherence of cells of seven E. coli strains to rubber slices treated with phosphatidylcholin (PC) or phosphatidylinositol (PI) and the adherence of cells of E. coli strain NG7C to PC- or PI-treated rubber slices implanted in the common bile duct in rats were studied in vitro. The rubber slices were incubated with 1 x 10(7) cfu radiolabeled E. coli cells/ml at 37 degrees C for 60 min and then drained and washed thrice in 2 ml PBS, and adherent E. coli cells were quantified by radioactivity counting. The results show that both PC and PI absorbed on the surface of slices reduced the adherence of E. coli cells in at least two ways, i.e. by changing surface properties in vitro and by reducing deposition of host-derived molecules on phospholipid-treated surfaces in vivo. The results may be of use for modification of the biomaterial surface in the clinical situation.

New model of reversible obstructive jaundice in rats

OBJECTIVE

To develop a simple, reversible, reproducible model of obstructive jaundice in rats that could also be used for studies of infection associated with foreign bodies in the biliary tract.

DESIGN

Open study.

SETTING

University of Lund, Sweden.

MATERIAL

18 Male Sprague-Dawley rats.

INTERVENTION

Laparotomy and the placing of a "minioccluder" (developed in this laboratory) around the common bile duct. This was left in place for five days.

MAIN OUTCOME MEASURES

Results of standard liver function tests measured on days 0, 5, and 12; the degree of obstruction seen on cholangiography on day 12; and changes in body weight on days 5 and 12.

RESULTS

Activities of hepatic enzymes and plasma bilirubin concentrations were significantly increased on day 5 compared with day 0 (p < 0.01 in each case), but had returned to the reference range by day 12. Cholangiography (n = 10) showed that even though the part of the common bile duct proximal to the minioccluder was dilated the distal part was of normal diameter and patent. By 5 days the animals had lost 5% of their mean body weight, but this increased by 8% during the 7 days after relief of the occlusion (day 12).

CONCLUSION

We have developed a reversible, reproducible model of obstructive jaundice in rats, which can be used for the study of topics related to obstructive jaundice and in particular infection associated with foreign bodies in the biliary tract.

Antitumor effects of new-type recombinant interleukin-2

Two new human recombinant interleukin-2 (rIL-2), 125-Ser-rIL-2, and 125-Ala-rIL-2, were generated by protein engineering technique. Both of them maintained the proliferation of natural killer (NK) cells, CTLL-2 cells and their long-term propagations. The mutated new rIL-2 also enhanced the bioactivity of NK cells and the cytotoxicity of tumor-infiltrating lymphocytes (TIL) against the target tumor cells. The above results were all compared with that of the native rIL-2 and a similarity between them was found, which indicates that new type rIL-2 could be used for adoptive immunotherapy of malignant diseases.

Effects of varying marijuana smoking profile on deposition of tar and absorption of CO and delta-9-THC

We investigated the effects of previously observed differences in smoking technique for marijuana (M) versus tobacco (T) on the amount of inhaled tar, the percentage retention of inhaled tar in the lung, the pre- to postcigarette boost in blood carboxyhemoglobin (COHb) and in serum delta-9-tetrahydrocannabinol (THC concentrations), and psychophysiologic responses to THC (increased heart rate and subjective "high"). Ten healthy, habitual smokers of M were studied on 6 separate days. On each day, subjects smoked a single M cigarette (approximately 900 mg, 1.24% delta-9-THC) using one of 6 different smoking profiles typical for marijuana [puff volume (PV) approximately 70 ml; breathholding time, (BHT) 14-16 s] or tobacco (PV approximately 45 ml; BHT 4-5 s) or a combination of the two techniques (PV approximately 70 ml and BHT 4-5 s; or PV approximately 45 ml and BHT 14-16 s). Inhaled volume (1.5 liters), interpuff interval (30 s) and number of puffs (6) were all fixed, except that for the approximately 45-ml PV condition, the number of puffs was increased to 10 in 2 additional sessions to standardize the total amount of cigarette consumed to that of the approximately 70-ml PV condition. The longer BHT significantly increased both percent retention of tar in the lung and the pre- to postsmoking rise in blood COHb, serum THC and heart rate, independent of puff volume and number. In contrast, the larger PV had no significant influence on these variables for the same amount of cigarette consumed.(ABSTRACT TRUNCATED AT 250 WORDS)