Development of a SYBR Green I real-time PCR for quantitative detection of Vibrio alginolyticus in seawater and seafood

AIM

Vibrio alginolyticus is an economically important micro-organism. The main aim of the present study was to develop a real-time polymerase chain reaction (PCR) assay for rapid, sensitive and effective quantification of V. alginolyticus in seawater and seafood.

METHODS AND RESULTS

Purified DNA of V. alginolyticus, artificially inoculated seawater and seafood tissue homogenates were subjected to the gyrB-targeted real-time PCR assay. Natural seawater and seafood samples were analysed by this real-time PCR protocol. Specificity tests showed that positive result was obtained only with V. alginolyticus strains. The detection sensitivity was determined to be 0.4 pg of genomic DNA equivalent to 72 cells per PCR in pure culture and 100 cells in 1 ml of seawater or seafood tissue homogenates. Single cell detection is achieved after 3 h of sample enrichment.

CONCLUSIONS

A sensitive and specific SYBR Green I-based real-time PCR assay targeting gyrB gene was successfully developed to quantify V. alginolyticus within 6 h in seawater and seafood samples.

SIGNIFICANCE AND IMPACT OF THE STUDY

No report on the molecular-based method was available for quantitative detection of V. alginolyticus. This work will provide a novel method for evaluation of the risk of V. alginolyticus to marine environmental health and seafood safety.

Selective hepatic vascular exclusion and Pringle maneuver: a comparative study in liver resection

OBJECTIVE

Most liver resections require champing of the hepatic pedicle (Pringle maneuver) to avoid excessive blood loss. But Pringle maneuver cannot control backflow bleeding of the hepatic vein. Resection of liver tumors involving hepatic veins may cause massive hemorrhage or air embolism from injuries of the hepatic vein. Although total hepatic vascular exclusion (THVE) can prevent bleeding of the hepatic vein effectively, it also may result in systemic hemodynamic disturbance because of the clamped inferior vena cava (IVC). SHVE, a new technique, can control the inflow and outflow of the liver without clamping the vena cava. We compared the effects of selective hepatic vascular exclusion (SHVE) and Pringle maneuver in resection of liver tumors involving the junction of the hepatic vein.

METHODS

From January 2000 to October 2005, 2100 patients with liver tumors had undergone liver resections in our department. Among them, tumors of 235 cases adhered to or were close to the junction of one or more hepatic veins. Both SHVE and Pringle maneuver were used to control blood loss during hepatectomy. These 235 cases were divided into two groups: Pringle maneuver group (110) from January 2000 to December 2002 and SHVE group (125) from January 2003 to October 2005. Data were analyzed regarding the intraoperative and postoperative courses of the patients. In the SHVE group, total SHVE (clamping the porta hepatis and all major hepatic veins) was used in 69 cases and partial SHVE (clamping the porta hepatic and one or two hepatic veins) in 56 cases. There were three methods in hepatic veins occlusion: ligating with suture, encircling and occluding with tourniquets and clamping with Satinsky clamps.

RESULTS

There was no difference between the two groups regarding the age, gender, tumor size, cirrhosis and HBsAg rate, ischemia time and operating time. Intraoperative blood loss and transfusion requirements were significantly decreased in the SHVE group. Hepatic veins rupture with massive blood loss occurred in 14 and air embolism in three during the tumor resection, but there was no massive blood loss and air embolism in the SHVE group due to hepatic vein occlusion. Postoperative bleeding, reoperation, liver failure and mortality rate were higher, and ICU stay and hospital stay were longer in the Pringle group than those in the SHVE group.

CONCLUSION

SHVE is much more effective than Pringle maneuver in controlling intraoperative bleeding. It can prevent massive blood loss and air embolism from hepatic veins rupture and can reduce the postoperative complication rate and mortality rate. Clamping the hepatic veins with Satinsky clamps is much safer and easier than ligating with suture and occluding with tourniquets.

Tumor suppressor menin: the essential role of nuclear localization signal domains in coordinating gene expression

Menin is encoded by the tumor suppressor gene MEN1 that is mutated in patients with an inherited tumor syndrome, multiple endocrine neoplasia type 1 (MEN1). Although menin is a nuclear protein and directly binds to DNA through its nuclear localization signals (NLSs), the precise role for each of the NLSs in nuclear translocation and gene expression remains to be elucidated. Here, we show that point mutations in three individual NLSs, NLS1, NLS2, and a novel accessory NLS, NLSa, do not block nuclear translocation, but compromise the ability of menin to repress expression of the endogenous insulin-like growth factor binding protein-2 (IGFBP-2) gene. This repression is not released by an inhibitor of histone deacetylases. Although subtle mutations in menin NLSs do not affect menin association with chromatin, they abolish menin binding to the IGFBP-2 promoter in vivo. Furthermore, each of the NLSs is also crucial for menin-mediated induction of caspase 8 expression. Together, these results suggest that menin may act as a scaffold protein in coordinating activation and repression of gene transcription and that its NLSs play a more important role in controlling gene transcription than merely targeting menin into the nucleus.

An automatic approach for estimating bolus arrival time in dynamic contrast MRI using piecewise continuous regression models

We present two regression models for the automatic estimation of bolus arrival times (BATs) in dynamic contrast MRI datasets. Results of Monte Carlo simulation experiments show that the means and standard deviations of the estimated BATs are within the sampling interval even in the presence of significant noise.

A physiologic model of capillary-tissue exchange for dynamic contrast-enhanced imaging of tumor microcirculation

We present a multiple compartment, mammillary distributed-parameter model for capillary-tissue exchange, which can be implemented with dynamic contrast-enhanced imaging to study kinetic heterogeneity in tumors. The proposed n-compartment model consists of a vascular distributed-parameter compartment in direct exchange with a number (n - 1) of interstitial compartments. It is applied to a prostate tumor case study to illustrate the possible co-existence of two kinetically distinct compartments in the tumor, and the estimation of useful physiological parameters (such as perfusion, mean transit time, fractional volumes, and transfer and rate constants) associated with tissue microcirculation. The present model exhibits the convenient property of a separable impulse residue response function in time domain, which can be used to provide further insights and understanding on the physiological basis of tissue enhancement parameters commonly used for correlation studies with tumor histological diagnosis.

A numerical method for estimating blood flow by dynamic functional imaging

We present a numerical deconvolution scheme for estimating regional blood flow and tissue retention functions by dynamic functional imaging. The present approach implements the Tikhonov-Miller regularization in general form, which allows for prior knowledge or assumptions to be incorporated during the deconvolution process, so as to stabilize the solution against variations due to noise. Appropriate approximations and simplifications in the context of functional imaging, were also introduced to ease numerical computations. Monte Carlo simulation experiments were carried out to study the applicability of the present approach and to compare with other deconvolution techniques previously studied.

Experiences and lessons about soft-tissue flaps covering of severe open tibial fracture

OBJECTIVE

To sum up experiences and lessons ab out management of soft-tissue reconstruction in open tibial fracture over a 6-year period.

METHODS

Twenty-two flap reconstructions were performed to tre at soft-tissue defect of 22 patients with open tibial fracture Type IIIB (Gustilo) from 1993 to 1998. The cases were analyzed and discussed retrospectively aft er follow up of 12-61 months.

RESULTS

The size of the flap ranged from 6.6 cm(2) to 28.18 cm(2) and the rate of flap failure was 13.6%. Besides, 3 partial necrosis and 2 postoperative infections occurred in this series.

CONCLUSIONS

For soft tissue defect of delayed open tibial fracture Type IIIB, flap reconstruction is still an optimal option. The experiences we obtained are 1) to design a triangular skin extension or a small Z-plasty over the pedicle to reduce the flap tension; 2) to select a unilateral external fixation to provide convenience for any secondary manipulation; and 3) to use serial debridement to diminish flap failure.

[Cloning and biological regulating effects of human WAF1 gene]

OBJECTIVE

To clone human WAF1 gene and construct WAF1-pcDNA3 recombinant plasmid, and to explore the biological regulating effects of WAF1 gene.

METHODS

Human WAF1 gene was amplified and cloned into pcDNA3 vector by RT-PCR and DNA direct sequencing from Hela cells. By immunofluorescence and immunohistochemistry staining, the identify the expression of the inserted WAF1 gene and its biological regulating effects on Rb, cyclin D1 gene.

RESULTS

Human WAF1-pcDNA3 recombinant plasmid was correctly constructed and transfected into Hct-8 cells. P21WAFI/Clip was successfully expressed. The functional characterization of the inserting WAF1 gene implied that P21WAF1/Cip1 expression could upregulate Rb gene and downregulate cyclin D1 gene at protein level.

CONCLUSION

Human WAF1-pcDNA3 can modulate the protein expression of the downstream gene.

Synthesis of diphenylmethane from formalin and benzene in a biphasic system with 12-tungstophosphoric acid

Heteropoly acids such as H3PW12O40 are exceptionally active catalysts in the synthesis of diphenylmethane from benzene and formalin (aqueous formaldehyde) in a biphasic system and can be recycled simply by drying the aqueous phase at room temperature.

[The change of immunocompetent cells in normal human dental pulp during development of immature permanent teeth]

OBJECTIVE

To study changes of several immunocompetent cells (ICCs), namely, pulpal dendritic cells (PDCs), T lymphocytes, B lymphocytes, and endothelial cells, in normal human dental pulp according to different development stage of completely erupted but not fully developed premolar in order to provide evidence for local immune defense mechanisms during development of immature permanent teeth.

METHODS

Based on the dental development status, the pulp tissue was classified into the following groups: big trumped-shaped group, small trumped-shaped group and closed group. The above mentioned cells were immunohistochemically examined by use of HLA-DR, CD45RO, CD20 mouse anti-human monoclonal antibodies. Double-staining was also done by use of the former two antibodies. The number of positively stained cells or blood vessels was counted and statistically analyzed.

RESULTS

1. Normal dental tissue of three groups all expressed HLA-DR+ PDCs. Among three groups, the number of HLA-DR+ cells in big trumped-shaped group was more than that of small trumped-shaped group and closed group. 2. There was no significant difference of positive blood vessel rate of HLA-DR expressing endothelial cells among three groups. 3. There was no significant difference of CD45RO+ T cells among three groups. 4. By use of double-labeling immunohistochemistry, HLA-DR+ PDCs and CD45RO+ T cells were found to be rarely in contact with each other. Correlation analysis between two kinds of cells did not indicate the linear relationship.

CONCLUSIONS

The number of PDCs tends to decrease with increasing age in the developing dental pulp of human normal tooth, other ICCs are not related with dental development.

The RESID Database of protein structure modifications and the NRL-3D Sequence-Structure Database

The RESID Database is a comprehensive collection of annotations and structures for protein post-translational modifications including N-terminal, C-terminal and peptide chain cross-link modifications. The RESID Database includes systematic and frequently observed alternate names, Chemical Abstracts Service registry numbers, atomic formulas and weights, enzyme activities, taxonomic range, keywords, literature citations with database cross-references, structural diagrams and molecular models. The NRL-3D Sequence-Structure Database is derived from the three-dimensional structure of proteins deposited with the Research Collaboratory for Structural Bioinformatics Protein Data Bank. The NRL-3D Database includes standardized and frequently observed alternate names, sources, keywords, literature citations, experimental conditions and searchable sequences from model coordinates. These databases are freely accessible through the National Cancer Institute-Frederick Advanced Biomedical Computing Center at these web sites: http://www. ncifcrf.gov/RESID, http://www.ncifcrf.gov/NRL-3D; or at these National Biomedical Research Foundation Protein Information Resource web sites: http://pir.georgetown.edu/pirwww/dbinfo/resid .html, http://pir.georgetown.edu/pirwww/dbinfo/nrl3d .html

iProClass: an integrated, comprehensive and annotated protein classification database

The iProClass database is an integrated resource that provides comprehensive family relationships and structural and functional features of proteins, with rich links to various databases. It is extended from ProClass, a protein family database that integrates PIR superfamilies and PROSITE motifs. The iProClass currently consists of more than 200,000 non-redundant PIR and SWISS-PROT proteins organized with more than 28,000 superfamilies, 2600 domains, 1300 motifs, 280 post-translational modification sites and links to more than 30 databases of protein families, structures, functions, genes, genomes, literature and taxonomy. Protein and family summary reports provide rich annotations, including membership information with length, taxonomy and keyword statistics, full family relationships, comprehensive enzyme and PDB cross-references and graphical feature display. The database facilitates classification-driven annotation for protein sequence databases and complete genomes, and supports structural and functional genomic research. The iProClass is implemented in Oracle 8i object-relational system and available for sequence search and report retrieval at http://pir.georgetown.edu/iproclass/.

Protein Information Resource: a community resource for expert annotation of protein data

The Protein Information Resource, in collaboration with the Munich Information Center for Protein Sequences (MIPS) and the Japan International Protein Information Database (JIPID), produces the most comprehensive and expertly annotated protein sequence database in the public domain, the PIR-International Protein Sequence Database. To provide timely and high quality annotation and promote database interoperability, the PIR-International employs rule-based and classification-driven procedures based on controlled vocabulary and standard nomenclature and includes status tags to distinguish experimentally determined from predicted protein features. The database contains about 200,000 non-redundant protein sequences, which are classified into families and superfamilies and their domains and motifs identified. Entries are extensively cross-referenced to other sequence, classification, genome, structure and activity databases. The PIR web site features search engines that use sequence similarity and database annotation to facilitate the analysis and functional identification of proteins. The PIR-Inter-national databases and search tools are accessible on the PIR web site at http://pir.georgetown.edu/ and at the MIPS web site at http://www.mips.biochem.mpg.de. The PIR-International Protein Sequence Database and other files are also available by FTP.

Glycosylation-dependent cell adhesion molecule 1 (GlyCAM 1) is induced by prolactin and suppressed by progesterone in mammary epithelium

Glycosylation-dependent cell adhesion molecule 1 (GlyCAM 1), a mucin-like endothelial glycoprotein, was induced by PRL and suppressed by progesterone in the mammary gland of mice, and in HC11 mouse mammary epithelial cells. Complementary DNA microarray analysis revealed that expression of GlyCAM 1 was reduced in the mammary gland of PRL-gene disrupted mice (PRL-/-) compared with control (PRL+/-) littermates. This result was confirmed by in situ hybridization and immunostaining. The messenger RNA (mRNA) encoding GlyCAM 1 was present in mammary epithelia of PRL-stimulated mice. Immunohistochemistry indicated that GlyCAM 1 protein was detectable both in mammary epithelia and in the ductal lumen in PRL+/- virgin mice, but not in PRL-/- mice. GlyCAM 1 mRNA was highly induced by grafting pituitary glands from normal littermates. Trace amounts of mRNA for GlyCAM 1 were detected by RT-PCR in mammary tissue of PRL-/- mice. Progesterone inhibited both basal and PRL-stimulated GlyCAM 1 transcription. In HC11 cells, GlyCAM 1 mRNA was induced in cells treated with insulin, dexamethasone, and PRL. Similar to the in vivo studies, progesterone inhibited the induction of GlyCAM 1 transcription. In CHO cells, PRL stimulated transcription of a luciferase reporter gene containing an 800-bp promoter fragment of GlyCAM 1, and progesterone partially suppressed the PRL effect. These data demonstrate that expression of GlyCAM 1 in mammary gland is under the control of both PRL and progesterone.

Alkali and alkaline-earth metal ketyl complexes: isolation, structural diversity, and hydrogenation/protonation reactions

The use of hexamethylphosphoric triamide (HMPA) as a stabilizing ligand allowed successful isolation of a series of structurally characterizable alkali metal and calcium ketyl complexes. Reaction of lithium and sodium with one equivalent of fluorenone and reaction of sodium with one equivalent of benzophenone in THF, followed by addition of two equivalents of HMPA, yielded the corresponding ketyl complexes 1, 2, and 11, respectively, as microketyl-bridged dimers. If one equivalent of HMPA was used in the reaction of sodium with fluorenone, a further aggregated complex, the mu3-ketyl-bridged tetramer 3, was isolated, whereas analogous reaction of benzophenone with sodium afforded the trimeric ketyl complex 13, rather than a simple benzophenone analogue of 3. In the reaction of potassium with fluorenone, the use of two equivalents of HMPA gave the tetramer 4, rather than a dimeric complex analogous to 1 or 2. Compared to the tetrameric sodium complex 3, there is an extra HMPA ligand that bridges two of the four K atoms in 4. When 0.5 equiv of HMPA was used in the above reaction, complex 5, a THF-bridged analogue of 4, was isolated. In the absence of HMPA, the reaction of sodium with an excess of fluorenone yielded the tetrameric ketyl complex 6, in which two of the four Na atoms are each terminally coordinated by a fluorenone ligand, and the other two Na atoms are coordinated by a THF ligand. Two bridging THF ligands are also observed in 6. Reaction of 1,2-bis(biphenyl-2,2'-diyl)ethane-1,2-diol (7) with two equivalents of LiN(SiMe3)2 or NaN(SiMe3)2 in the presence of four equivalents of HMPA easily afforded 1 or 2, respectively, via C-C bond cleavage of a 1,2-diolate intermediate. The reaction of calcium with two equivalents of fluorenone or benzophenone in the presence of HMPA gave the corresponding complexes that bear two independent ketyl ligands per metal ion. In the presence of 3 or four equivalents of HMPA, the fluorenone ketyl complex was isolated in a six-coordinate octahedral form (10), while the benzophenone ketyl complex was obtained as a five-coordinate trigonal bipyramid (13). The radical carbon atoms in both benzophenone ketyl and fluorenone ketyl complexes are still in an sp2-hybrid state. However, in contrast with the planar configuration of the whole fluorenone ketyl unit, the radical carbon atom in a benzophenone ketyl species is not coplanar with any of the phenyl groups; this explains why benzophenone ketyl is more reactive than fluorenone ketyl. Hydrolysis of 2 or 11 with 2N HCI yielded the corresponding pinacol-coupling product, while treatment of 2 or 11 with 2-propanol, followed by hydrolysis, gave the pairs fluorenone and fluorenol or benzophenone and benzhydrol, respectively. A possible mechanism for these reactions is proposed.

Wide-range amplified spontaneous emission wavelength tuning in a solid-state dye waveguide

Amplified spontaneous emission (ASE) in an organic-dye- (DCM-) doped poly(methyl methacrylate)/silica-gel hybrid material planar waveguide was investigated. ASE wavelength control and tuning in a wedge waveguide were realized. The tuning range of the waveguide can reach as much as 30 nm. This method can be applied to wide-range wavelength tuning in solid-state tunable lasers.

[Effects of chincap therapy for early anterior crossbite]

OBJECTIVE

To analysis the effects of chincap therapy for early anterior crossbite and mandibular prognathism.

METHODS

136 patients anterior crossbite and mandibular prognathism aged from 3 to 14 years old at the start of treatment were treated with active chincap with bilateral force of 700 to 1000 gram. Every patient wore chin cap 12 to 14 hours daily, and most of those patients used removable appliances to open the crossbite of incisors. According to the age of patients, they were divided into four groups, C1 (3-5 years old), C2 (6-8 years old), C3 (9-11 years old) and C4 (12-14 years old). When the treatment ended after two years, we analyzed the models by measuring the length of maxillary on the models before and after treatment (U1 and U2 that's the distance between the tip of 1|1 and the distal plane of 6|6 or V|V and the overjet before and after treatment (L1 and L2). Then we calculated the obtained distance for the mandible related to the maxillary position X(X = (L2-L1)-(U2-U1)) and analyzed treating time and mandibular retreating speed in the four groups.

RESULTS

The obtained distance for the mandible related to the maxillary position in C1, C2, C3 and C4 groups were 3.27 +/- 0.99 mm, 4.62 +/- 1.33 mm, 4.43 +/- 1.28 mm and 2.63 +/- 0.92 mm respectively, and the treating time in four groups were 8.92 +/- 2.66 months, 10.47 +/- 2.21 months, 13.07 +/- 2.00 months, 20.50 +/- 3.96 months respectively. The retreating speed of the mandible related to the maxillary position in the four groups were 0.37 mm/month, 0.44 mm/month, 0.34 mm/month and 0.13 mm/month respectively. The effects of the treatment in C1, C2 and C3 groups (3-11 years old) were remarkable, especially in C1 group (3-5 years old).

CONCLUSION

The effects of chincap therapy for early anterior crossbite and mandibular prognathism were remarkable, especially for the very early crossbite patients.

The nucleotide sequence of a chinese isolate of wheat yellow mosaic virus and its comparison with a Japanese isolate. Brief report

The nucleotide sequences of wheat yellow mosaic virus isolated in China were determined and compared with a Japanese isolate of the same virus. Results showed that the viral genome had 7629 nucleotides for RNA1 and 3639 nucleotides for RNA2, which shared 97. 1% and 94.6% of identities to the RNAs of Japanese isolate. The single open reading frames in RNA1 and RNA2 encoded polyproteins with 2407 amino acids and 903 amino acids respectively, from which ten proteins may be produced by autolytic cleavage processing as the Japanese isolate. Since the sequence of WYMV RNA1 showed identity of less than 70% with that of WSSMV, it is further confirmed that WYMV is a distinct species within Bymovirus.

The clinical evaluation of peripheral nerve regeneration using turns/amplitude analysis system in EMG

OBJECTIVE

The aim of this study was to explore the value of turns/amplitude analysis system in EMG in evaluating peripheral nerve regeneration.

METHODS

Twenty-eight patients were investigated using turns/amplitude analysis system and conventional method in EMG after nerve repair. The patients were grouped according to their muscle power and their parameters in EMG were recorded and compared among groups as well as between the two methods.

RESULTS

Statistical differences of recovery percentage were shown among the groups except turns between M3:M4 using turns/amplitude system. However, none of the differences were present among them using conventional method. Among the parameters, amplitude/s advanced the fastest although it was the lowest at early stage and it also got the highest correlation coefficient (r = 0.848).

CONCLUSION

Turns/amplitude system was a reliable and sensitive method for evaluating nerve regeneration during nerve repair, which is more precise than the conventional method, and the amplitude was closely related to muscle function recovery.

Noise-induced oscillation and stochastic resonance in an autonomous chemical reaction system

An autonomous three-variable chemical reaction model, which has been developed to describe kinetic oscillations in the NO+CO reaction, subjected to external parametric noise, is investigated. Noise-induced coherent oscillations (NICO's) in the absence of deterministic oscillations are observed near supercritical Hopf bifurcation points, and the NICO strength goes through a maximum with increments of noise intensity, characteristic of the occurrence of stochastic resonance. On the other hand, these phenomena do not appear if the limit cycle is created by a saddle-loop bifurcation.

[In situ enzyme immunoassay for detection of hepatitis A virus]

OBJECTIVE

To establish a more simple and sensitive technique for identification of hepatitis A virus (HAV).

METHODS

HAV vaccine strain H2M20-K and wild-type strain He34 were used to infect KMB17 deploid cells in 96-well tissue culture plates and in situ enzyme immunoassay was used to detect viral infection with specific HA monoclonal antibody, A(OD) value of 1.8 was used as positive indicator.

RESULTS

Observation of viral replication showed the peak titer of viral infectivity reached at 20-25 days after viral infection, which was 4-6 day searlier than that of ELISA endpoint assay. Comparing the viral infectivity titers of 13 individual samples, the two methods revealed no significant statistic difference (t = 1.13, P > 0.05). Our tests showed that in situ EIA could better reflect the results of neutralization and 5 HAV positive isolates were directly isolated from 12 faecal samples after the first passage culture.

CONCLUSION

Although the sensitivities of the two tests were similar, the direct detection of virus/cell system with in situ EIA showed simple, easy to operate and reproducible, it may replace the conventionally used ELISA endpoint assay for identification of HAV, even for the other viruses.

Optical nonlinearity and structural phase-transition observation of organic dye-doped polymer silica hybrid material

The optical nonlinearity of organic dye-doped poly(methyl methacrylate) (PMMA)-silica-gel hybrid material was investigated by second-harmonic-generation measurement. We found that incorporation of in situ polymerized solgel precursors into the organic dye-doped PMMA significantly improved the nonlinear optical stability of the system. However, improvement of thermal stability occurred only when a sufficient amount of silica gel was incorporated. A structural phase transition from pure polymer to a hybrid system was found near a 10-mol.% silica-gel concentration. The optimum polymer/tetraethoxysilane molar ratio is 2:1 to 1:1.

Osteoblast-specific gene expression after transplantation of marrow cells: implications for skeletal gene therapy

Somatic gene therapies require targeted transfer of the therapeutic gene(s) into stem cells that proliferate and then differentiate and express the gene in a tissue-restricted manner. We have developed an approach for gene therapy using marrow cells that takes advantage of the osteoblast specificity of the osteocalcin promoter to confine expression of chimeric genes to bone. Adherent marrow cells, carrying a reporter gene [chloramphenicol acetyltransferase (CAT)] under the control of a 1.7-kilobase rat osteocalcin gene promoter, were expanded ex vivo. After transplantation by intravenous infusion, engrafted donor cells in recipient mice were detected by the presence of the transgene in a broad spectrum of tissues. However, expression of the transgene was restricted to osteoblasts and osteocytes, as established by biochemical analysis of CAT activity and immunohistochemical analysis of CAT expression at the single cell level. Our data indicate that donor cells achieved long-term engraftment in various tissues of the recipients and that the CAT gene under control of the osteocalcin promoter is expressed specifically in bone. Thus, transplantation of multipotential marrow cells containing the osteocalcin promoter-controlled transgene provides an efficacious approach to deliver therapeutic gene expression to osteoblasts for treatment of bone disorders or tumor metastasis to the skeleton.

Effectors of the stringent response target the active site of Escherichia coli adenylosuccinate synthetase

Guanosine 5'-diphosphate 3'-diphosphate (ppGpp), a pleiotropic effector of the stringent response, potently inhibits adenylosuccinate synthetase from Escherichia coli as an allosteric effector and/or as a competitive inhibitor with respect to GTP. Crystals of the synthetase grown in the presence of IMP, hadacidin, NO3-, and Mg2+, then soaked with ppGpp, reveal electron density at the GTP pocket which is consistent with guanosine 5'-diphosphate 2':3'-cyclic monophosphate. Unlike ligand complexes of the synthetase involving IMP and GDP, the coordination of Mg2+ in this complex is octahedral with the side chain of Asp13 in the inner sphere of the cation. The cyclic phosphoryl group interacts directly with the side chain of Lys49 and indirectly through bridging water molecules with the side chains of Asn295 and Arg305. The synthetase either directly facilitates the formation of the cyclic nucleotide or scavenges trace amounts of the cyclic nucleotide from solution. Regardless of its mode of generation, the cyclic nucleotide binds far more tightly to the active site than does ppGpp. Conceivably, synthetase activity in vivo during the stringent response may be sensitive to the relative concentrations of several effectors, which together exercise precise control over the de novo synthesis of AMP.

[Treatment of benign prostatic hyperplasia with laser through the endoscope]

OBJECTIVE

To evaluate the effect of transurethral laser prostatectomy (TULP) and its relation with the size of prostate.

METHODS

469 benign prostatic hyperplasia receiving TULP from 1988 to 1998 were reviewed retrospectively, and the methods of operation and preoperative and postoperative symptom were compared. The effect of 233 patients undergoing TULP was compared with the size of the prostate.

RESULTS

The average value for IPSS of 469 patients decreased from 26.7 (preoperation) to 14.2 (postoperation). The mean value of maximum uroflow rate increased from 6.2 ml/s (preoperation) to 11.8 ml/s (postoperation). No difference was seen in postoperative effect between the transurethral contact and noncontact laser prostatectomy. If the estimating weight of prostate exceeded 50 g, the maximum flow rate after 3 years was decreased evidently, the value of IPSS increased to over 20.

CONCLUSIONS

If the estimating weight of prostate is less than 50 g, TULP is indicated.

The evaluation of MR localization for intracranial arteriovenous malformation treated with gamma knife

OBJECTIVE

To evaluate the image quality, treatment effectiveness and complications of intracranial arteriovenous malformation (AVM) treated with gamma knife by MR localization.

METHODS

According to Spetzler-Martin grading system, 73 intracranial AVMs were classified and treated with gamma knife by MR localization. The follow-up period was 6 to 34 months. The quality of MR localization image, the changes of AVM nidi after treatment were analyzed. Using ANOV (analysis of variance) statistic methods, we explored the relationship among the edema surrounding the AVM nidus, the radiation dosage and the AVM volume after treatment.

RESULTS

The margin of AVM nidus was clear in all images. In the 73 images, MR signal of the local cranial skin and bone on the fixed points of head frame disappeared in 11 (15%), high or low shallow curve signals in the cerebral border occurred in 5 (7%), the remaining 57 (78%) images had no artifacts. Based on the Spetzler-Martin grading score of AVM, the obliteration rates of AVM nidus were 100% in II, 88% in III, 57% in IV, 75% in V, 60% in VI during the 6-34 months follow-up after treatment. Edema around the AVM nidi occurred in 42 (57.5%) cases; among them, 27 were in slight degree, 10 in medium degree, and 5 in severe degree. Through ANOV statistic methods, we suggested that the degree of edema had no relation with the radiation dosage and AVM volume. Only one case had rebleeding 13 months after radiosurgery.

CONCLUSION

MR localization for AVM treated with gamma knife is reliable and effective.

Increased transmission of vertical hepatitis C virus (HCV) infection to human immunodeficiency virus (HIV)-infected infants of HIV- and HCV-coinfected women

The transmission of perinatal hepatitis C virus (HCV) infection was studied retrospectively in 62 infants born to 54 HCV- and human immunodeficiency virus (HIV)-coinfected women enrolled in a prospective natural history study of HIV transmission. Infant HCV infection was assessed by nested RNA polymerase chain reaction. The overall rate of vertical HCV transmission was 16.4% (9/62). Most HCV-infected children did not develop antibodies to HCV. The rate of HCV infection was higher among HIV-infected infants (40%) than among HIV-uninfected infants (7.5%; odds ratio, 8.2; P = .009). This difference in transmission was not related to differences in maternal HCV load, as measured by branched DNA assay, or mode of delivery. Why HIV-infected infants of HCV- and HIV-coinfected women have significantly higher rates of perinatal HCV transmission remains to be elucidated. The rate of HCV transmission in HIV-uninfected infants of HCV- and HIV-coinfected women is similar to that reported for infants born to HIV-seronegative mothers.

Analysis of p53 gene mutations in keloids using polymerase chain reaction-based single-strand conformational polymorphism and DNA sequencing

BACKGROUND

Keloids are the result of a dysregulated wound healing process. They are characterized by the formation of excess scar tissue that proliferates beyond the boundaries of the original wound. Somatic mutations of p53 have been implicated as causal events in up to 50% of all human malignancies. In addition, p53 has been shown to play an important role in controlling cell proliferation and apoptosis. We hypothesize that mutations in p53 can lead to a hyperproliferative state that can result in keloid formation.

OBJECTIVE

To detect p53 DNA mutations in tissues and cultured fibroblasts from skin lesions of 7 patients with keloids.

DESIGN

The polymerase chain reaction followed by single-strand conformational polymorphism analysis and direct DNA sequencing were used to detect p53 gene mutations.

SETTING

The Department of Dermatology, Henry Ford Hospital, Detroit, Mich.

PATIENTS

Seven patients with keloids seen for routine surgical excision of their lesions. Normal DNA specimens were obtained from buccal smears and healthy skin samples from these patients.

RESULTS

Mutations in the p53 were identified in all patients by polymerase chain reaction followed by single-strand conformational polymorphism analysis and subsequently confirmed by DNA sequencing. A mutation in exon 5 resulting in amino acid substitution was found in 1 of the patients in keloid tissue and cultured keloid fibroblasts (codon 156, CGC-->CCC, arginine-->proline). Frameshift mutations in exons 5 and 6 caused by the insertion or deletion of a nucleotide at different positions were found in 6 patients with keloids in both keloid tissues and cultured fibroblasts. Mutations in exon 4 resulting in amino acid substitution were found in all patients in both keloid tissues and cultured fibroblasts (all in codon 72, CGC-->CCC, arginine-->proline). No p53 mutations were detected in buccal smears or cultured fibroblasts from healthy skin samples of any of the patients.

CONCLUSIONS

Focal mutations in p53 may increase cell proliferation and decrease cell death in the dysregulated growth patterns that have been clinically documented. An understanding of the pattern of all growth dysregulation related to keloids may lead to new therapeutic strategies.

Phase-compensation experiment with a 37-element adaptive optics system

An experimental study on phase compensation for turbulent effects with a 37-element adaptive optics system is performed in both a simulated turbulence cell and in a real atmosphere. The experimental results demonstrate that the compensated Strehl ratio S(0), which is influenced mainly by the deformable-mirror fitting error, has a functional form S(0) = exp[-kappa(d/r(0))(5/3)], where r(0) is Fried's coherence length and d is the average interval of the actuators on the deformable mirror. The fitting parameter kappa is 0.45. Numerical simulations are also performed with the experimental parameters. The numerical results are in agreement with data obtained in the experiment, which shows that the direct-tilt phase-reconstruction method used in our four-dimensional simulation code is reasonable.

The human homolog of Saccharomyces cerevisiae CDC45

In budding yeast Saccharomyces cerevisiae CDC45 is an essential gene required for initiation of DNA replication. A structurally related protein Tsd2 is necessary for DNA replication in Ustilago maydis. We have identified and cloned the gene for a human protein homologous to the fungal proteins. The human gene CDC45L is 30 kilobases long and contains 15 introns. The 16 exons encode a protein of 566 amino acids. The human protein is 52 and 49.5% similar to CDC45p and Tsd2p, respectively. The level of CDC45L mRNA peaks at G1-S transition, but total protein amount remains constant throughout the cell cycle. Consistent with a role of CDC45L protein in the initiation of DNA replication it co-immunoprecipitates from cell extracts with a putative replication initiator protein, human ORC2L. In addition, subcellular fractionation indicates that the association of the protein with the nuclear fraction becomes labile as S phase progresses. The CDC45L gene is located to chromosome 22q11.2 region by cytogenetics and by fluorescence in situ hybridization. This region, known as DiGeorge syndrome critical region, is a minimal area of 2 megabases, which is consistently deleted in DiGeorge syndrome and related disorders. The syndrome is marked by parathyroid hypoplasia, thymic aplasia, or hypoplasia and congenital cardiac abnormalities. CDC45L is the first gene mapped to the DiGeorge syndrome critical region interval whose loss may negatively affect cell proliferation.

An experimental study about the incorrect electrophysiological evaluation following peripheral nerve injury and repair

OBJECTIVE

This experiment was designed to explore the reasons of incorrect electrophysiological evaluation following peripheral nerve repair.

METHODS

Twenty-four New Zealand white rabbits were used and divided into 2 groups. The first group of animals underwent severance of gastrocnemius muscle nerve and only the medial branch of the nerve was anastomosed. The second group of rabbits underwent severance of the muscle nerve as well as sural nerve, then the proximal end of the sural nerve was anastomosed to the distal end of the muscle nerve. Electrophysiological and morphological methods were used to study these models 3 months after the operations.

RESULTS

Electrophysiologic comparison of muscle action potential for group A and B showed a significant difference in the values (p < 0.05). Morphologic studies showed that the muscle weights of group B were significantly lower than those of group A, but the myelin thickness failed to show any statistical difference between the two groups.

CONCLUSION

Results suggested that one of the sources causing incorrect electrophysiological evaluation could be misdirected regeneration, resulting from a sensory fascicle anastomosing to a motor one or vice versa. The unfunctional regeneration showed low values of muscle action potentials (p < 0.05) as well as excessive fibrillation potentials, and marked atrophy of the muscles (p < 0.05).

Ambiguities in mapping the active site of a conformationally dynamic enzyme by directed mutation. Role of dynamics in structure-function correlations in Escherichia coli adenylosuccinate synthetase

On the basis of ligated crystal structures, Asn21, Asn38, Thr42, and Arg419 are not involved in the chemical mechanism of adenylosuccinate synthetase from Escherichia coli, yet these residues are well conserved across species. Purified mutants (Asp21 --> Ala, Asn38 --> Ala, Asn38 --> Asp, Asn38 --> Glu, Thr42 --> Ala, and Arg419 --> Leu) were studied by kinetics, circular dichroism spectroscopy, and equilibrium ultracentrifugation. Asp21 and Arg419 are not part of the active site, yet mutations at positions 21 and 419 lower kcat 20- and 10-fold, respectively. Thr42 interacts only through its backbone amide with the guanine nucleotide, yet its mutation to alanine significantly increases Km for all substrates. Asn38 hydrogen-bonds directly to the 5'-phosphoryl group of IMP, yet its mutation to alanine and glutamate has no effect on Km values, but reduces kcat by 100-fold. The mutation Asn38 --> Asp causes 10-57-fold increases in Km for all substrates along with a 30-fold decrease in kcat. At pH 5.6, however, the Asn38 --> Asp mutant is more active, yet binds IMP 100-fold more weakly, than the wild-type enzyme. Proposed mechanisms of ligand-induced conformational change and subunit aggregation can account for the properties of mutant enzymes reported here. The results underscore the difficulty of using directed mutations alone as a means of mapping the active site of an enzyme.

Hydrogels and hydrocolloids: an objective product comparison

It is difficult for providers to make selections from the vast array of currently available wound care products. There has been a paucity of objective data generated by a non-biased source comparing one product to another. In order for our Wound Care Team to recommend products for system-wide formulary purchase and patient use, we needed to develop a process for product comparison. A strategy for objective evaluation of hydrocolloid and amorphous hydrogel products was created, and these products were assessed clinically by experienced wound care providers. Laboratory testing included measurement of each product's ability to absorb water versus normal saline versus actual patient wound fluid. There were major differences in various products' abilities to absorb the fluids. These objective data from the laboratory, along with the subjective comparison of clinical performance, allowed our Wound Care Team to objectively rank the hydrocolloids and hydrogels and include those preferred products in our Wound Care Product Formulary.

p53 and apoptosis alterations in keloids and keloid fibroblasts

Keloids are the result of a dysregulated wound-healing process and are characterized by formation of excess scar tissue that proliferates beyond the boundaries of the inciting wound. In this study, we investigated the expression of key proteins involved in regulating apoptosis in keloids. Twenty archival paraffin-embedded keloid samples were randomly selected for an immunoperoxidase assay with antibodies against fas, p53, bcl-2, and bcl-x proteins using the target antigen-retrieval technique. Apoptosis was assessed in keloids and normal skin and in keloid and normal fibroblasts by the TdT-mediated dUTP nick-end labeling (tunel) assay on tissue sections, fibroblast cultures, and by flow cytometry for cell suspensions. We found that 18 of 20 keloids expressed p53 protein; bcl-2 was expressed by keloid fibroblasts in 19 of 20 keloids, and all specimens had prominent fas expression throughout the tissue. The distribution of these three antigens was regional within each lesion and followed a consistent pattern of p53 and bcl-2 expression colocalized to the hypercellular, peripheral areas of each keloid in a perinuclear pattern (p < .001). In contrast, an inverse distribution of fas expression was shown, with staining being more diffuse across the cell surfaces and limited to the central, more hypocellular regions in16 of 17 keloids (p < .001). There was no specific staining pattern in these keloids with antihuman bcl-x. In vitro studies on cultured keloid fibroblasts (derived from six patients) revealed maintenance of the p53+, bcl-2+ phenotype up to passage 10. Neither neonatal nor normal adult skin fibroblasts expressed either antigen but could be induced to express p53 by exposure to adriamycin. Keloid lesions and keloid fibroblasts were found to have lower rates of apoptosis than normal controls. Keloid fibroblasts displayed enhanced apoptosis rates in response to hydrocortisone, gamma interferon, and hypoxia treatment as compared with normal adult fibroblasts. Focal dysregulation of p53 combined with upregulation of bcl-2 may help produce a combination of increased cell proliferation and decreased cell death in the younger, hypercellular areas of the keloid. This phenotype is reversed in the older areas of the keloid and may prevent malignant degeneration, thus favoring normal apoptosis as evidenced by prominent fas expression.

[Studies on anti-inflammatory and immune effects of moxibustion]

An animal model of adjuvant arthritis in rats was established, and the effects of anti-inflammatory and immune regulation of moxibustion at "Shenshu" point were investigated. The results showed that it could lighten a local inflammatory reaction, eliminate swelling of the metatarsal and reduce it's girth, prevent or reduce the polyarthritises, maintain the weight and shorten the course of the disease. The results also showed that moxibustion could recover and promote the effects of the Concanavalin A (ConA) inducing splenic lymphocyte proliferation in rats, promote interleukin 2 (IL-2) production, decrease IL-1 contents. The indexes mentioned above were significantly different as compared with contral group. Above results indicated that moxibustion had directly anti-inflammatory and subsidence of swelling effects, through enhancing the ability of immune response the immune functions were lightened and regulated. Therefore, the anti-inflammatory and immune and anti-allergy effects of body were enhanced.

The role of endothelial nitric oxide synthase in the pathogenesis of a rat model of hepatopulmonary syndrome

BACKGROUND & AIMS

The hepatopulmonary syndrome occurs when intrapulmonary vasodilatation causes impaired arterial gas exchange in liver disease. The pathogenesis is poorly understood, although nitric oxide may be involved. Common bile duct ligation in the rat is a model of the hepatopulmonary syndrome, but no studies have evaluated NO in pulmonary vasodilatation in this model. The aim of this study was to determine whether NO contributes to intrapulmonary vasodilatation after bile duct ligation.

METHODS

Endothelial and inducible NO synthase (NOS) levels and localization and NO activity in pulmonary artery rings were assessed after bile duct ligation.

RESULTS

Pulmonary endothelial NOS levels increased and alveolar vascular staining was enhanced after bile duct ligation. No change in pulmonary inducible NOS levels or localization was detected. Increased endothelial NOS levels correlated with alterations in gas exchange and were accompanied by enhanced NO activity and a blunted response to phenylephrine, reversible by NOS inhibition, in pulmonary artery rings. Portal-vein-ligated animals, which do not develop intrapulmonary vasodilatation, had no changes in pulmonary NOS production or in NO activity in pulmonary artery rings.

CONCLUSIONS

NO, derived from pulmonary vascular endothelial NOS, contributes to intrapulmonary vasodilation in animal hepatopulmonary syndrome.