A recurrence quantification analysis-based channel-frequency convolutional neural network for emotion recognition from EEG.

Constructing a reliable and stable emotion recognition system is a critical but challenging issue for realizing an intelligent human-machine interaction. In this study, we contribute a novel channel-frequency convolutional neural network (CFCNN), combined with recurrence quantification analysis (RQA), for the robust recognition of electroencephalogram (EEG) signals collected from different emotion states. We employ movie clips as the stimuli to induce happiness, sadness, and fear emotions and simultaneously measure the corresponding EEG signals. Then the entropy measures, obtained from the RQA operation on EEG signals of different frequency bands, are fed into the novel CFCNN. The results indicate that our system can provide a high emotion recognition accuracy of 92.24% and a relatively excellent stability as well as a satisfactory Kappa value of 0.884, rendering our system particularly useful for the emotion recognition task. Meanwhile, we compare the performance of the entropy measures, extracted from each frequency band, in distinguishing the three emotion states. We mainly find that emotional features extracted from the gamma band present a considerably higher classification accuracy of 90.51% and a Kappa value of 0.858, proving the high relation between emotional process and gamma frequency band.

Suppression of Mcl-1 induces apoptosis in mouse peritoneal macrophages infected with Mycobacterium tuberculosis.

The effect of myeloid cell leukemia-1 (Mcl-1) inhibition on apoptosis of peritoneal macrophages in mice infected with Mycobacterium tuberculosis was investigated and the primary signaling pathway associated with the transcriptional regulation of Mcl-1 was identified. Real-time PCR and western blotting indicated that Mcl-1 transcript and protein expression are upregulated during infection with virulent M. tuberculosis H37Rv and Xinjiang strains but not with attenuated M. tuberculosis strain H37Ra or Bacillus Calmette-Guérin. Mcl-1 transcript and protein expression were downregulated by specific inhibitors of the Janus kinase/signal transducer and activator of transcription (JAK/STAT), mitogen-activated protein kinase (MAPK) and phosphoinositol 3-kinase (PI3K) pathways (AG490, PD98059 and LY294002, respectively). The strongest inhibitor of Mcl-1 expression was PD98059, the MAPK inhibitor. Flow cytometry demonstrated that the rate of apoptosis in peritoneal macrophages is significantly higher in mice infected with M. tuberculosis and the rate of apoptosis is correlated with the virulence of the strain of M. tuberculosis. Apoptosis was found to be upregulated by AG490, PD98059 and LY294002, whereas inhibition of the MAPK pathway sensitized the infected macrophages to apoptosis. Taken together, these results suggest that specific downregulation of Mcl-1 significantly increases apoptosis of peritoneal macrophages and that the MAPK signaling pathway is the primary mediator of Mcl-1 expression.

[Source Appointment and Assessment of Heavy Metal Pollution in Surface Dust in the Main District Bus Stops of Tianshui City].

In this study, a PMF model was used to identify the sources and pollution level of heavy metals in the surface dust of a bus station. On the basis of the traditional heavy metal pollution evaluation methods, the Hakanson toxicity response coefficient was used to modify the traditional weight. The matter-element extension theory was introduced to reflect the toxicological properties and hazard degree of the heavy metals, and the matter-element extension model was established to evaluate the pollution level of heavy metals in the surface dust of the study area. The results were compared with Igeo, PN, and RI. ① Except for Co and V, the other heavy metals were higher than the Gansu soil background values by 1.29-9.30 times. The points of Cu and Pb exceeded the rate by 100%, and Cr, Ni, and As exceeded the rate by 96.15%, 94.23%, and 96.15%, respectively. ② PMF showed that source 1 was a natural source, and its contribution rate to V was 32.12%. Source 2 was natural-traffic pollution sources, contributing 51.50% and 33.37% to Cu and Co, respectively. Source 3 was a construction waste pollution source, with contribution rates of 45.06% and 44.70% for Cr and Ni, respectively, and source 4 was a coal-traffic mixed source, with contribution rates of 49.89% and 75.25% for As and Pb, respectively. ③ The matter-element evaluation results showed that the surface dust of the bus stops was mainly class IV (moderately polluted), and 13% of sample points were still clean, 37% were moderately polluted, and 25% were slightly and heavily polluted. The results of this method were quite different from the PN results and were more consistent with the RI results, indicating that its evaluation results were more sensitive and can be used for heavy metal pollution assessment.

[Inhibitory effect of dihydroartemisinin on the growth of human prostate cancer PC-3M cells and its mechanism].

OBJECTIVE: To study the effects of dihydroartemisinin on the apoptosis of and the vascular endothelial growth factor (VEGF) expression in prostate cancer cell line PC-3M in androgen-independent prostate cancer. METHODS: PC-3M cells were treated with different doses (0, 25, 50 and 100 micromol/L) of dihydroartemisinin for 48 hours, their growth activity analyzed by MTT colorimetric assay and flow cytometry, and changes in the activities of caspase-3 and -8 detected by colorimetric assay. The expression of VEGF mRNA was determined by semi-quantitative RT-PCR, and that of the VEGF protein by Western blotting. RESULTS: Compared with the 0 micromol/L control group, the 25, 50 and 100 micromol/L dihydroartemisinin groups showed significantly increased apoptosis of PC-3M cells ([2.92 +/- 0.45]% vs [8.85 +/- 0.74]%, [12.83 +/- 0.84]% and [18.65 +/- 1.24]%, P < 0.01), and dose-dependent increase in the activities of caspase-8 ([0.47 +/- 0.05 ] U/microg vs [1.22 +/- 0.15], [1.76 +/- 0.07] and [2.91 +/- 0.24] U/microg, P < 0.01) and caspase-3 ([0.44 +/- 0.07] U/microg vs [0.95 +/- 0.08], [1.48 +/- 0.14] and [2.92 +/- 0.45] U/microg, P < 0.01). The expressions of VEGF mRNA and protein were decreased in a concentration-dependent manner. CONCLUSION: Dihydroartemisinin can significantly suppress the growth of PC-3M cells, promote their apoptosis and reduce the expressions of VEGF mRNA and protein, which may serve to explain its inhibitory effect on tumor and angiogenesis.

[Primary non-Hodgkin's lymphoma of the testis and penis: clinical analysis of 5 cases].

OBJECTIVE: To improve the clinical diagnosis and treatment of primary non-Hodgkin's lymphoma of male genitalia. METHODS: We retrospectively reviewed the clinical data of 5 cases of primary non-Hodgkin's lymphoma of male genitalia, 4 in the testis and 1 in the penis, we also analyzed the relevant literature and clinical significance of the disease. RESULTS: All the 5 cases were treated by surgery and pathologically confirmed to be non-Hodgkin's lymphoma. Three of them received chemotherapy, and the other 2 (1 in the testis and 1 in the penis) underwent both chemotherapy and radiotherapy after the operation. Follow-up averaged 25 months, during which 1 of the patients died and the other 4 survived. CONCLUSION: Primary non-Hodgkin's lymphoma of male genitalia is an uncommon disease with atypical clinical presentations and poor prognosis, which occurs mostly in elderly males. Definite diagnosis of the disease mainly depends on histopathology and immunohistochemistry. Surgery with multiagent chemotherapy and radiotherapy is advisable for its treatment.

Clonal mesenchymal stem cells derived from human bone marrow can differentiate into hepatocyte-like cells in injured livers of SCID mice.

There is increasing evidence that human mesenchymal stem cells (hMSCs) can be a valuable, transplantable source of hepatocytes. Most of the hMSCs preparations used in these studies were likely heterogeneous cell populations, isolated by adherence to plastic surfaces or by density gradient centrifugation. Therefore, the participation of other unknown trace cell populations cannot be rigorously discounted. Here we report the isolation and establishment of a cloned human MSC line (chMSC) from human bone marrow primary culture, through which we confirmed the hepatic differentiation capability of authentic hMSCs. chMSCs expressed markers of mesenchymal cells, but not markers of hematopoietic stem cells. In vitro, chMSCs can differentiate into either mesenchymal cells or cells exhibiting hepatocyte-like phenotypes. When transplanted intrasplentically into carbon tetrachloride-injured livers of SCID mice, EGFP-tagged chMSCs engrafted into the host liver parenchyma, exhibited typical hepatocyte morphology, form a three-dimensional architecture, and differentiate into hepatocyte-like cells expressing human albumin and alpha-1-anti-trypsin. By confocal microscopy, ultrafine intercellular nanotubular structures were visible between adjacent transplanted and host hepatocytes. We postulate that these structures may assist in the phenotype conversion of chMSCs, possibly by exchange of cytoplasmic components between native hepatocytes and transplanted cells. Thus, a clonal pure population of hMSCs, which can be expanded in culture, may have potential as a cellular source for substitution damaged cells in hepatic injury.

Staphylococcus aureus capsule type 8 antibodies provide inconsistent efficacy in murine models of staphylococcal infection.

Staphylococcus aureus is a clinically important capsule-forming bacterium. The capsule polysaccharide (CPs) occurs as different chemical structures depending on the serotype of the organism, but one form, capsular polysaccharide type 8 (CPs8) found in clinical isolates, is largely unstudied. The potential of CPs8 as a vaccine target was evaluated using two approaches. The first approach used a conjugate vaccine, made by chemically linking purified CPs8 to the outer membrane protein complex of N. meningitidis serotype B (OMPC). In efficacy studies, the CPs8-OMPC conjugate vaccine was immunogenic in Balb/c mice, however the immune response gave no protection from death after a lethal intravenous (IV) challenge with S. aureus Becker. In the second approach, two monoclonal antibodies were produced against CPs8 (mAbs 8E8 and 1C10). These were found to have functional activity in an opsonophagocytic killing assay (OPA), and provided protection from a lethal challenge when bacteria were pre-opsonized ex vivo before intra-peritoneal (IP) challenge. However, mAb 8E8 was not efficacious in the lethal challenge model, in which antibodies were passively transferred to the peritoneum and the animals were infected via the tail vein 18-24 h later. Additionally, the monoclonal antibodies did not opsonize capsule-expressing S. aureus Becker obtained from in vivo growth conditions. These results indicated that functional capsule antibodies may not be sufficient for protection from S. aureus under all in vivo conditions.

Biological and Biomechanical Evaluation of Autologous Tendon Combined with Ligament Advanced Reinforcement System Artificial Ligament in a Rabbit Model of Anterior Cruciate Ligament Reconstruction.

OBJECTIVE: To compare the biomechanical and histological changes in a rabbit model after reconstructing the anterior cruciate ligament (ACL) with solely autologous tendon and with autologous tendon combined with the ligament advanced reinforcement system (LARS) artificial ligament. METHODS: Anterior cruciate ligament reconstruction was performed in 72 knees from 36 healthy New Zealand white rabbits (bodyweight, 2500-3000 g). The Achilles tendons were harvested bilaterally. The left ACL were reconstructed solely with autografts (autologous tendon group), while the right ACL were reconstructed with autografts combined with LARS ligaments (combined ligaments group). The gross observation, histological determination, and the tension failure loads in both groups were evaluated at 12 weeks (n = 18) and 24 weeks (n = 18) postoperatively. RESULTS: Gross examination of the knee joints showed that all combined ligaments were obviously covered by a connective tissue layer at 12 weeks, and were completely covered at 24 weeks. Fibrous tissue ingrowth was observed between fascicles and individual fibers in the bone-artificial ligament interface at both time points; this fibrovascular tissue layer localized at the bone-artificial ligament interface tended to be denser in specimens obtained at 24 weeks compared with those obtained at 12 weeks. The tension failure loads of the knees were similar in the autologous tendon group and the combined ligaments group at 12 weeks (144.15 ± 3.92 N vs. 140.88 ± 2.75 N; P > 0.05), and at 24 weeks (184.15 ± 1.96 N vs. 180.88 ± 3.21 N; P > 0.05). CONCLUSION: Reconstructing the ACL in rabbits using autologous tendon combined with the LARS artificial ligament results in satisfactory biointegration, with no obvious immunological rejection between the autologous tendon and the artificial ligament, and is, therefore, a promising ACL reconstruction method.

Effect of gap junctions on RAW264.7 macrophages infected with H37Rv.

BACKGROUND: Apoptosis and inflammation have been shown to play an important role in the mechanisms involved in the pathogenesis of Mycobacterium tuberculosis (MTB) infection. When macrophages undergo apoptosis and polarization, gap junctions (GJs) may be needed to provide conditions for their functions. Connexin 43 (Cx43) and connexin 37 (Cx37) are the main connexins in macrophages that participate in the formation of GJ channels. METHODS: An H37Rv infection RAW264.7 macrophage model was established to investigate the associate between connexins and host macrophage immune defense response after MTB infection. First, Real-time Polymerase Chian Reaction (RT-PCR) was used to detect the mRNA expression of Cx43 and Cx37. Cx43 protein expression and location was detected by western blotting and immunofluorescence. Confocal microscope was used to assay the gap junctional intercellular communication (GJIC). Then, electron microscope used to observe the morphology of macrophages. Finally, RAW264.7 macrophage apoptosis and mitochondrial membrane potential was detected by flow cytometry, and the expression of inflammation factors such as CD86, CD206, and IL-6, IL-10, TNF-α, and TGF-ß were detected by Real-time PCR and enzyme-linked-immunosorbent serologic assay (ELISA). RESULTS: H37Rv infection significantly promoted host macrophage Cx43 mRNA and protein expression (increased 1.6-fold and 0.3-fold respectively), and enhanced host macrophage GJIC. When host macrophage cell-to-cell communication induced by H37Rv infection, the apoptosis rate and inflammatory factors expression also increased. CONCLUSIONS: The results confirm that H37Rv infection can obviously induce host macrophage Cx43 expression and enhance GJIC, which may implicated in host macrophage inflammatory reaction, to regulate the release of inflammatory factors and/or initiate apoptosis to activate host immune defense response.

A small hairpin RNA targeting myeloid cell leukemia-1 enhances apoptosis in host macrophages infected with Mycobacterium tuberculosis.

Myeloid cell leukemia-1 (Mcl-1) plays an important role in various cell survival pathways. Some studies indicated that the expression of Mcl-1 was upregulated in host cells during infection with the virulent Mycobacterium tuberculosis strain, H37Rv. The present study was designed to investigate the effect of inhibiting Mcl-1 expression both in vivo and in vitro on apoptosis of host macrophages infected with M. tuberculosis using a small hairpin (sh)RNA. Mcl-1 expression was detected by the real time-polymerase chain reaction, western blotting, and immunohistochemistry. Flow cytometry and transmission electron microscopy were used to measure host macrophage apoptosis. We found elevated Mcl-1 levels in host macrophages infected with M. tuberculosis H37Rv. The expression of Mcl-1 was downregulated efficiently in H37Rv-infected host macrophages using shRNA. Knockdown of Mcl-1 enhanced the extent of apoptosis in H37Rv-infected host macrophages significantly. The increased apoptosis correlated with a decrease in M. tuberculosis colony forming units recovered from H37Rv-infected cells that were treated with Mcl-1-shRNA. Reducing Mcl-1 accumulation by shRNA also reduced accumulation of the anti-apoptotic gene, Bcl-2, and increased expression of the pro-apoptotic gene, Bax, in H37Rv-infected host macrophages. Our results showed that specific knockdown of Mcl-1 expression increased apoptosis of host macrophages significantly and decreased the intracellular survival of a virulent strain of M. tuberculosis. These data indicate that interference with Mcl-1 expression may provide a new avenue for tuberculosis therapy.

Improving the immunogenicity of a trivalent Neisseria meningitidis native outer membrane vesicle vaccine by genetic modification.

Trivalent native outer membrane vesicles (nOMVs) derived from three genetically modified Neisseria meningitidis serogroup B strains have been previously evaluated immunologically in mice and rabbits. This nOMV vaccine elicited serum bactericidal activity (SBA) against multiple N. meningitidis serogroup B strains as well as strains from serogroups C, Y, W, and X. In this study, we used trivalent nOMVs isolated from the same vaccine strains and evaluated their immunogenicity in an infant Rhesus macaque (IRM) model whose immune responses to the vaccine are likely to be more predictive of the responses in human infants. IRMs were immunized with trivalent nOMV vaccines and sera were evaluated for exogenous human serum complement-dependent SBA (hSBA). Antibody responses to selected hSBA generating antigens contained within the trivalent nOMVs were also measured and we found that antibody titers against factor H binding protein variant 2 (fHbpv2) were very low in the sera from animals immunized with these original nOMV vaccines. To increase the fHbp content in the nOMVs, the vaccine strains were further genetically altered by addition of another fHbp gene copy into the porB locus. Trivalent nOMVs from the three new vaccine strains had higher fHbp antigen levels and generated higher anti-fHbp antibody responses in immunized mice and IRMs. As expected, fHbp insertion into the porB locus resulted in no PorB expression. Interestingly, higher expression of PorA, an hSBA generating antigen, was observed for all three modified vaccine strains. Compared to the trivalent nOMVs from the original strains, higher PorA levels in the improved nOMVs resulted in higher anti-PorA antibody responses in mice and IRMs. In addition, hSBA titers against other strains with PorA as the only hSBA antigen in common with the vaccine strains also increased.

Rapid isolation of dengue-neutralizing antibodies from single cell-sorted human antigen-specific memory B-cell cultures.

Monitoring antigen-specific memory B cells and the antibodies they encode is important for understanding the specificity, breadth and duration of immune response to an infection or vaccination. The antibodies isolated could further help design vaccine antigens for raising relevant protective immune responses. However, developing assays to measure and isolate antigen-specific memory B cells is technically challenging due to the low frequencies of these cells that exist in the circulating blood. Here, we describe a flow cytometry method to identify and isolate dengue envelope-specific memory B cells using a labeled dengue envelope protein. We enumerated dengue-envelope specific memory B cells from a cohort of dengue seropositive donors using this direct flow cytometry assay. A more established and conventional assay, the cultured B ELISPOT, was used as a benchmark comparator. Furthermore, we were able to confirm the single-sorted memory B-cell specificity by culturing B cells and differentiating them into plasma cells using cell lines expressing CD40L. The culture supernatants were assayed for antigen binding and the ability of the antibodies to neutralize the cognate dengue virus. Moreover, we successfully isolated the heavy and light Ig sequences and expressed them as full-length recombinant antibodies to reproduce the activity seen in culture supernatants. Mapping of these antibodies revealed a novel epitope for dengue 2 virus serotype. In conclusion, we established a reproducible methodology to enumerate antigen-specific memory B cells and assay their encoded antibodies for functional characterization.

Effects of Ziziphus jujuba fruit extracts on cytochrome P450 (CYP1A2) activity in rats.

Drug-drug interactions have become a serious problem in the clinic, since plant-based medicines are extensively used. The present study investigated the effects of Ziziphus jujuba fruit (ZJ) extract on the pharmacokinetics of phenacetin, a typical substrate of a cytochrome P450 enzyme CYP 1A2, in rats. The rats were pretreated with the water extract (1.0 g · kg(-1)) or the ethanolic extract (3.6 g · kg(-1)) of ZJ for 10 days, and the pharmacokinetics of phenacetin was investigated after intravenous administration. In an in vitro assay, acetaminophen formation in the hepatic microsomes of ZJ-treated rats was investigated to assess CYP1A2 activity. Our results demonstrated that the treatment with the water and ethanolic extracts of ZJ decreased the plasma concentration of phenacetin and increased the plasma concentration of acetaminophen, resulting in a 43.2% and 15.5% reduction in the AUC0-120 of phenacetin, respectively, and a 53.2% and 64.9% increase in the AUC0-120 of acetaminophen, respectively after intravenous administration. The water or ethanolic extract of ZJ significantly increased the clearance of phenacetin and acetaminophen formation in hepatic microsomes. In conclusion, ZJ extracts displayed effects on the pharmacokinetics of phenacetin and increased the CYP1A2 activity in rats. Therefore, precaution on drug-drug interactions should be taken when ZJ is co-administered with drugs metabolized by CYP1A2, which may result in decreased concentrations of these drugs.

Evaluation of a multilocus sequence typing system for Staphylococcus epidermidis.

Staphylococcus epidermidis is a significant cause of nosocomial disease. However, the taxonomy of this pathogen, particularly at subspecies level, is unclear. A multilocus sequence typing (MLST) scheme has therefore been investigated as a tool to elucidate taxonomic relationships within this group, based on genetic relatedness. DNA sequences for internal fragments of seven housekeeping genes were compared in 47 geographically and temporally diverse S. epidermidis isolates that were obtained from clinical infections. Twenty-three different allelic profiles were detected; 17 of these were represented by single strains and the largest profile group contained 17 isolates. Diversity of the same collection of isolates was investigated by using PFGE of SmaI-digested genomic DNA to test the discrimination and validity of the MLST approach. Isolates within the largest profile group were resolved into four distinct PFGE clusters on the basis of their SmaI digest patterns. Isolates within other profile groups that contained multiple isolates had matching PFGE SmaI patterns within each group. It appears that MLST is an effective method for grouping S. epidermidis strains at the subspecies level; however, it is not as discriminatory as it has been for other species for which MLST schemes have been established and, used alone, would not be a useful method for epidemiological studies. In addition, it was demonstrated that this method was effective for confirming the identity of S. epidermidis CoNS (coagulase-negative) isolates.

DNA replicative functions of highly-expressed, codon-optimized human papillomavirus proteins E1 and E2.

Human papillomavirus (HPV) DNA replication requires functional HPV early (E) proteins E1 and E2. To determine the biological activity of HPV 16 E1 and E2 mutant proteins under consideration as vaccine candidates, we developed a sensitive real time PCR assay that monitors HPV origin-of-replication-driven DNA synthesis. The assay was used to determine the DNA replicative functions of highly-expressed, codon-optimized HPV 16 E1 and E2 wild type and mutant proteins in transient transfections. Under the assay conditions, the HPV 16 E1 mutant (W439R, G482D) did not support HPV origin-driven DNA synthesis. In contrast, however, an HPV 16 E2 mutant bearing an E39A substitution, reported previously to be severely compromised for DNA replication, was found to be reduced only two-fold in activity and, therefore, considered not sufficiently inactivated for use in vaccines that depend on endogenous protein expression.

Expression of hepatitis B virus X protein in transgenic mice.

AIM: To establish a mice model harboring hepatitis B virus x gene (adr subtype) for studying the function of hepatitis B virus X protein, a transactivator of viral and cellular promoter/enhancer elements. METHODS: Expression vector pcDNA3-HBx, containing CMV promoter and hepatitis B virus x gene open reading fragment, was constructed by recombination DNA technique. Hela cells were cultured in DMEM and transfected with pcDNA3-HBx or control pcDNA3 plasmids using FuGENE6 Transfection Reagent. Expression of pcDNA3-HBx vectors in the transfected Hela cells was confirmed by Western blotting. After restriction endonuclease digestion, the coding elements were microinjected into male pronuclei of mice zygotes. The pups were evaluated by multiplex polymerase chain reaction (PCR) at genomic DNA level. The x gene transgenic mice founders were confirmed at protein level by Western blotting, immunohistochemistry and immunogold transmission electron microscopy. RESULTS: Expression vector pcDNA3-HBx was constructed by recombination DNA technique and identified right by restriction endonuclease digestion and DNA direct sequencing. With Western blotting, hepatitis X protein was detected in Hela cells transfected with pcDNA3-HBx plasmids, suggesting pcDNA3-HBx plasmids could express in eukaryotic cells. Following microinjection of coding sequence of pcDNA3-HBx, the embryos were transferred to oviducts of pseudopregnant females. Four pups were born and survived. Two of them were verified to have the HBx gene integrated in their genomic DNA by multiplex PCR assay, and named C57-TgN(HBx)SMMU1 and C57-TgN(HBx)SMMU3 respectively. They expressed 17KD X protein in liver tissue by Western blotting assay. With the immunohistochemistry, X protein was detected mainly in hepatocytes cytoplasm of transgenic mice, which was furthermore confirmed by immunogold transmission electon microscopy. CONCLUSION: We have constructed the expression vector pcDNA3-HBx that can be used to study the function of HBx gene in eukaryotic cells in vitro. We also established HBx gene (adr subtype) transgenic mice named C57-TgN (HBx)SMMU harboring HBx gene in their genome and express X protein in hepatocytes, Which might be a valuable animal system for studying the roles of HBx gene in hepatitis B virus life cycle and development of hepatocellular carcinoma in vivo.

Expression and cytotoxicity of EGFP-labeled D-amino acid oxidase in HeLa cells.

To observe the expression of R. gracilis D-amino acid oxidase (DAAO) gene labeled by EGFP in HeLa cells and how it mediates cytotoxicity, DAAO cDNA and EGFP gene were cloned into Eukaryotic expression vector pIRES to construct DAAO gene expression vector pIRES-DAAO. HeLa cells were transfected with pIRES-DAAO in vitro. Expression of EGFP gene in HeLa-D cells was observed under a fluorescent microscope. The efficiency of transfection was analyzed by flow cytometry (FCM). The fluorescent cells were screened by FCM and were named HeLa-D. The activity of HeLa-D cells was detected by MTT colorimetric assay after they were treated with D-Ala at various concentrations. The results indicted that expression of EGFP gene in HeLa-D cells was seen under fluorescent microscope and HeLa-D cells were screened by FCM. Apparently,the prodrug D-Ala killed HeLa-D cells. These results demonstrate that EGFP gene can be regarded as a reporter gene to screen the cells transduced with DAAO quickly, and DAAO/D-Ala suicide gene system may prove helpful in gene therapy of cancer.

The first metatarsal web space: its applied anatomy and usage in tracing the first dorsal metatarsal artery in thumb reconstruction.

OBJECTIVE: To clarify the anatomical relationship of the structures in the first toe webbing space for better dissection of toes in thumb reconstruction. METHODS: The first dorsal metatarsal artery, the first deep transverse metatarsal ligament and the extensor expansion were observed on 42 adult cadaveric lower extremities. Clinically the method of tracing the first dorsal metatarsal artery around the space of the extensor expansion was used in 36 cases of thumb reconstruction. RESULTS: The distal segments of the first dorsal metatarsal artery of Gilbert types I and II were located superficially to the extensor expansion. The harvesting time of a toe was shortened from 90 minutes to 50 minutes with 100% survival of reconstructed fingers. CONCLUSIONS: The distal segment of the first dorsal metatarsal artery lies constantly at the superficial layer of the extensor expansion. Most of the first metatarsal arteries of Gilbert types I and II can be easily located via the combined sequential and reverse dissection around the space of the extensor expansion.

Palmar tilt changes due to distal radius fractures and radiocarpal instability: a biomechanical study.

OBJECTIVE: To investigate the impact of dorsally angulated malunited distal radius fractures on the stability of the radiocarpal joint. METHODS: Eight fresh upper limb specimens from 4 human cadavers were obtained, in which radial osteotomy was performed to prepare models of Frykman I distal radius fracture. Pressure-sensitive film was applied to study the changes in the contact area distribution and the pressure load across the radiocarpal joint in response to palmar tilt variation, and the lateral radiograph of the wrist was taken at the end of pressure loading. RESULTS: When the dorsal tilt exceeded 10 degrees, the radioscaphoid and radiolunate articular contact areas were markedly decreased (P<0.01) and shifted to the dorsal aspect of the radiocarpal joint, where the pressure load was significantly increased (P<0.01). A dorsal radiocarpal subluxation was liable to occur on the sagittal plane when the dorsal tilt exceeded 40 degrees. CONCLUSION: A dorsal tilt over 10 degrees is the most primary cause of radiocarpal instability after a dorsal deformity due to distal radius fractures.

Analysis of the bactericidal response to an experimental Neisseria meningitidis vesicle vaccine.

Rabbit immunogenicity studies on an experimental trivalent native outer membrane vesicle vaccine derived from three serogroup B strains were conducted to evaluate the effectiveness of this vaccine at inducing an antibody response with serum bactericidal activity against meningococcal strains of other serogroups in addition to serogroup B strains. The results showed that the vaccine was capable of inducing an effective broad-based bactericidal antibody response in rabbits against a small sample of Neisseria meningitidis strains of serogroups C, W135, and X and, to a lesser extent, serogroups A and Y. Analysis of antibody specificity using a bactericidal depletion assay revealed that antibodies to lipooligosaccharide (LOS), PorA, and NadA induced in rabbits by the experimental trivalent outer membrane vesicle vaccine were responsible for most of the bactericidal activity against strains of the other N. meningitidis serogroups. In the case of serogroup A N. meningitidis strains, the outer membrane antigen NadA was primarily responsible for protection. The outer membrane antigens fHbp and OpcA were also effective in removing some bactericidal activity from the sera.