erythro-1-Naphthyl-1-(2-piperidyl)methanol: synthesis, resolution, NMR relative configuration, and VCD absolute configuration

The erythro isomer of 1-naphthyl-1-(2-piperidyl)methanol 4, an efficient chiral modifier for asymmetric heterogeneous hydrogenation, was obtained as the major isomer (95%) in two steps while the threo isomer can be obtained as the major isomer (67%) in three steps. erythro-4 and threo-4 were resolved on a CHIRALCEL OD-RH column. It has been shown by VCD that the diastereomer determined as the erythro by NMR was indeed the erythro and that the first eluted (-)-enantiomer on CHIRALCEL OD-R or -RH columns has the (1R,2S) configuration. The VCD studies identify the presence of at least five conformers in CDCl(3) solution. Moreover, this (-)-(1R,2S) absolute configuration found by VCD is consistent with the expected stereo-outcome of catalytic hydrogenation of pyruvate into lactate, which supported the (+)-(1S,2R) assignment.

[Effects of IFN-gamma gene-modified hepatocytes on TGF-beta 1 and its receptor in mice infected with Schistosoma japonicum]

AIM

To explore the anti-schistosomal hepatic fibrosis effect and the changes in transforming growth factor-beta 1 (TGF-beta 1) and its receptors (TGF-beta RII) in S. japonicum infected mice after intrasplenic transplantation of gamma-interferon (IFN-gamma) gene-modified hepatocytes.

METHODS

At 16 wk after infection with cercariae of Schistosoma japonicum, the mice were intrasplenically transplantated with murine hepatocytes which had been transfected with IFN-gamma gene-combinant adenovirus vector. ELISA, immunohistochemical and dot blot techniques were used to observe the dynamic changes in IFN-gamma, TGF-beta 1, TGF-beta RII and type I, III collagen.

RESULTS

The intrasplenic transplantation of IFN-gamma gene modified hepatocytes effectively expressed IFN-gamma and obviously reduced the production and deposition of type I, III collagen as well as TGF-beta 1 and TGF-beta RII.

CONCLUSION

IFN-gamma gene transplantation has anti-hepatic fibrosis efficacy in Schistosoma japonicum-infected mice, being related to its role of decreasing the expression of TGF-beta 1 and TGF-beta RII.

Pig amelogenin gene expresses a unique exon 4

The pig amelogenin gene was isolated from a Lambda genomic library, and a 6.3 kb SalI/XbaI restriction fragment, inclusive of exons 3 through 7, was subcloned into a plasmid vector. DNA sequencing revealed two putative exon 4 sequences. The derived amino acid sequence of exon 4a, KSGRWGARLTAFVSSVQ, had previously been identified in a 190-amino-acid amelogenin isoform by protein sequencing. Exon 4b encoded the peptide DLYLEAIRIDRTAF, which is homologous to exon 4-encoded segments reported for human, mouse, and rat. Oligonucleotides from both of these exons were used to amplify cDNA generated from developing teeth. Amplification products were analyzed by agarose gel electrophoresis, cloned, and characterized by DNA sequencing. Exon 4a was found in transcripts encoding amelogenin isoforms having 190 and 73 amino acids. Exon 4b was found only in apparent splicing intermediates that retained intron 3, but was not detected in any final mRNA transcripts. Pig amelogenin having apparent molecular mass of 23 kD were isolated from the enamel matrix and characterized by mass spectrometry. Two mass values, 18,512.5, and 18,571.2 Da, were measured that match the values predicted for the 162-amino-acid cleavage product of the 173-amino-acid amelogenin, and the 165-amino-acid cleavage product of the 190-amino-acid amelogenin, which includes 17 amino acids encoded by exon 4a. We conclude that the pig amelogenin gene expresses a unique exon 4 that is not homologous to, or evolved from, the exon 4 segment expressed in humans and rodents.

Photoimmobilization of biomolecules within a 3-dimensional hydrogel matrix

It has been recognized that a three-dimensional cell invasive scaffold that provides both topographical and chemical cues is desirable in regenerative tissue engineering to encourage cell attachment, migration, regrowth and ultimately tissue repair. Carbohydrate hydrogels are attractive for such applications because they are generally biocompatible and able to match the mechanical properties of most soft tissues. Although carbohydrate hydrogels have been previously modified with cell adhesive peptides and proteins, complicated hydrogel matrix activation was required prior to biomolecule coupling and, perhaps more importantly, the overall immobilization yield was low at approximately 1%. In this study, we report the photo-immobilization of a model biomolecule, ovalbumin (OVA), to agarose gel. We describe two methods of modification where the photoactive moiety is coupled to either the protein (i.e. OVA) or the matrix (i.e. agarose) prior to immobilization. We found that the photo-immobilization yield depends on the location of the photoactive moiety. Using photoactive OVA, 1.8% of the OVA initially incorporated into the agarose gel is immobilized; using photoactive agarose, 9.3% of the OVA initially mixed with the agarose is immobilized. The latter is a significant improvement over previous yields and may be useful in attaining our goal of immobilizing a biomolecule gradient for guided tissue regeneration.

Investigating the synergistic effect of combined neurotrophic factor concentration gradients to guide axonal growth

Neurotrophic factors direct axonal growth toward the target tissue by a concentration gradient, which is mediated through different tyrosine kinase cell surface receptors. In this study, well-defined concentration gradients of neurotrophic factors (NFs) allowed us to study the synergistic effect of different NFs (e.g. nerve growth factor [NGF], neurotrophin-3 [NT-3] and brain-derived neurotrophic factor [BDNF]) for axonal guidance of embryonic lumbar dorsal root ganglion cells (DRGs). Effective guidance of DRG axons was achieved with a minimum NGF concentration gradient of 133 ng/ml/mm alone, or combined NGF and NT-3 concentration gradients of 80 ng/ml/mm each. Interestingly, the combined concentration gradients of NGF and BDNF did not show any significant synergism at the concentration gradients studied. The synergism observed between NGF and NT-3 indicates that axons may be guided over a 12.5 mm distance, which is significantly greater than that of 7.5 mm calculated by us for NGF alone or that of 2 mm observed by others.

Transcriptional regulation of CCSP by interferon-gamma in vitro and in vivo

Interferon gamma (IFN-gamma), a potent cytokine inducing a wide range of immunologic activities, is increased in the airway secondary to viral infection or during an inflammatory response. This increase in IFN-gamma concentration may alter the expression of specific airway epithelial cell genes that regulate adaptation of airway inflammatory responses. One protein induced by IFN-gamma is Clara cell secretory protein (CCSP), which may contribute to the attenuation of airway inflammation. This study was done to investigate the molecular mechanism by which IFN-gamma stimulates the expression of the CCSP gene in mouse transformed Clara cells and transgenic mice. Deletion mapping and linker-scanning mutations demonstrated that IFN-gamma-induced expression of CCSP was regulated, in part, at the level of transcription. In vitro and in vivo studies verified that the minimal IFN-gamma-responsive segment was localized to the proximal 166 bp of the 5'-flanking region. Additionally, IFN-gamma-induced expression of CCSP was mediated indirectly through an interferon regulatory factor-1-mediated increase in hepatocyte nuclear factor-3beta.

Ovulation in the tree shrew (Tupaia belangeri) induced by gonadotrophins

The induction of ovulation by exogenous gonadotrophins is an important approach for recovering oocytes used for studies on the reproductive biology of some mammals. In the present study, pregnant mare serum gonadotrophin (PMSG) and human chorionic gonadotrophin (hCG) were used to induce ovulation in the tree shrew (Tupaia belangeri) using the following regimens. Groups A1-A3, multiple injections of PMSG (30-60 IU) followed by a single dose of hCG (30-60 IU); B1, combination of a single injection of PMSG (60 IU) with a single dose of hCG (60 IU); E1, combination of a single injection of PMSG (60 IU) with a single dose of hCG (30 IU) plus PMSG (30 IU); and administration of either PMSG (C1 and C2) or hCG (D1). The ovulation rate of animals producing oocytes with either first polar body or distinct perivitelline space, and the mean number of oocytes per animal were considered the most important criteria in each regimen. The most effective induction of ovulation was achieved in groups B1 and E1, with ovulation rates of 4/4 and 4/4, respectively, and mean numbers of ovulated oocytes per animal of 3.25 +/- 0.48 and 4.00 +/- 0.71 respectively. No ovulation was observed in the control group or in group D1. Therefore, regimes B1 and E1 were considered as the simplest and most effective for the induction of ovulation in the tree shrew.

Neural network based temporal video segmentation

The organization of video information in video databases requires automatic temporal segmentation with minimal user interaction. As neural networks are capable of learning the characteristics of various video segments and clustering them accordingly, in this paper, a neural network based technique is developed to segment the video sequence into shots automatically and with a minimum number of user-defined parameters. We propose to employ growing neural gas (GNG) networks and integrate multiple frame difference features to efficiently detect shot boundaries in the video. Experimental results are presented to illustrate the good performance of the proposed scheme on real video sequences.

Macrophage-derived chemokine gene transfer results in tumor regression in murine lung carcinoma model through efficient induction of antitumor immunity

Chemokine gene transfer represents a promising approach in the treatment of malignancies. Macrophage-derived chemokine (MDC) (CCL22) belongs to the CC chemokine family and is a strong chemoattractant for dendritic cells (DC), NK cells and T cells. Using adenoviral vectors, human MDC gene was transferred in vivo to investigate its efficacy to induce an antitumor response and to determine the immunologic mechanisms involved. We observed that intratumoral injection of recombinant adenovirus encoding human MDC (AdMDC) resulted in marked tumor regression in a murine model with pre-established subcutaneous 3LL lung carcinoma and induced significant CTL activity. The antitumor response was demonstrated to be CD4+ T cell- and CD8+ T cell-dependent. Administration of AdMDC induced chemoattraction of DC to the tumor site, facilitated DC migration to draining lymph nodes or spleen, and finally activated DC to produce high levels of IL-12. Furthermore, a significant increase of IL-4 production within the tumors was observed early after the AdMDC administration and was followed by the increase of IL-12 and IL-2 production. The levels of IL-2, IL-12 and IFN-gamma in serum, lymph nodes and spleen were also found to be higher in mice treated with AdMDC as compared with that in AdLacZ- or PBS-treated mice. The antitumor response induced by AdMDC was markedly impaired in IL-4 knockout mice, suggesting an important role of IL-4 in the induction of antitumor immunity by MDC. These results suggest that MDC gene transfer might elicit significant antitumor effects through efficient induction of antitumor immunity and might be of therapeutic potentials for cancer.

Lymphotactin cotransfection enhances the therapeutic efficacy of dendritic cells genetically modified with melanoma antigen gp100

Lymphotactin (Lptn) is a C chemokine that attracts T cells and NK cells. Dendritic cells (DC) are highly efficient, specialized antigen-presenting cells and antigen-pulsed DC has been regarded as promising vaccines in cancer immunotherapy. The aim of our present study is to improve the therapeutic efficacy of DC-based tumor vaccine by increasing the preferential chemotaxis of DC to T cells. In this study, Lptn and/or melanoma-associated antigen gp100 were transfected into mouse bone marrow-derived DC, which were used as vaccines in B16 melanoma model. Immunization of C57BL/6 mice with DC adenovirally cotransfected with Lptn and gp100 (Lptn/gp100-DC) could enhance the cytotoxicities of CTL and NK cells, increase the production of IL-2 and interferon-gamma significantly, as compared with immunization with gp100-DC, Lptn-DC, LacZ-DC, DC or PBS counterparts. The Lptn/gp100-DC immunized mice exhibited resistance to tumor challenge most effectively. It was found that the tumor mass of mice vaccinated by Lptn/gp100-DC showed obvious necrosis and inflammatory cell infiltration. In vivo depletion analysis demonstrated that CD8(+) T cells are the predominant T cell subset responsible for the antitumor effect of Lptn/gp100-DC and CD4(+) T cells were necessary in the induction phase of tumor rejection, while NK cells were less important although they participated in the antitumor response either in the induction phase or in the effector phase. In the murine model with the pre-established subcutaneous B16 melanoma, immunization with Lptn/gp100-DC inhibited the tumor growth most significantly when compared with other counterparts. These findings provide a potential strategy to improve the efficacy of DC-based tumor vaccines.

Inhibition of adenovirus cytotoxicity, replication, and E2a gene expression by adeno-associated virus

Adeno-associated virus (AAV) and the other parvoviruses have long been known to inhibit proliferation of nonpermissive cells. The mechanism of this inhibition is not thoroughly understood. To learn how AAV interacts with host cells, we have begun an investigation into AAV's relationship with adenovirus (Ad), AAV's most efficient helper virus. AAV, but not UV-inactivated AAV, delayed Ad-induced cytotoxicity and inhibited Ad E2a gene expression. AAV, but not UV-inactivated AAV or a recombinant AAV vector, inhibited Ad DNA replication. To determine whether AAV or its replication (Rep) proteins alter Ad early gene expression, we measured steady state E2a mRNA levels in AAV and Ad coinfected cultures and in a cell line (Neo6) that inducibly expresses the Rep proteins. AAV, but not UV-AAV, and Rep expression resulted in diminution of E2a protein and mRNA levels. To determine whether the AAV Rep proteins directly affect the individual Ad early promoters, we constructed luciferase reporter plasmids containing each of the five early promoters. Cotransfection of Ad-luciferase and an AAV rep gene-expressing plasmid in HeLa cells demonstrated that Rep78 repressed the E1a, E2a, and E4 promoters but trans-activated the E1b and E3 promoters. In the presence of a cotransfected E1a-expressing plasmid, Rep78 repressed expression from all five promoters. These results indicate that Rep may have different effects on the Ad early promoters dependent upon the presence of the E1a trans-activating protein.

[Effects of cervical vertebra rehabilitation pill on antiinflammation and analgesia]

OBJECTIVE

To study the effects of cervical vertebra rehabilitation pill on anti-inflammation and analgesia.

METHODS

Hot board and body distortion induced by acertic acid methods were applied in mice for analgesia experiment. Granuloma induced by cotton ball implantation tumefaction in feet induced by carrageenin in rats and auricle tumefaction induced by croton oil in mice were applied for anti-flammation experiment.

RESULTS

Cervical vertebra rehabilitation pill could significantly prolong the latent period of pain reaction induced by hot board in mice and markedly decrease the frequency of body distortion induced by acertic acid. Cervical vertebra rehabilitation pill also could significantly inhibit the tumefaction in feet induced by carrageenin, reduce the degree of tumefaction in auricle induced by croton oil in mice and inhibit the formation of granuloma induced by cotton ball implantation in subcutaneous part.

CONCLUSION

Cervical vertebra rehabilitation pill has significant effects on anti-inflammation and analgesia.

Vaccination with IL-18 gene-modified, superantigen-coated tumor cells elicits potent antitumor immune response

OBJECTIVE

To investigate the induction of antitumor immune response by vaccination with interleukin-18 (IL-18) gene-modified, C215Fab-SEA-coated tumor cells.

MATERIALS

A B16-C215 cell clone stably expressing C215 antigen was established by transfecting the gene-encoding C215 antigen into B16 melanoma cells. The manipulated tumor cell vaccine was prepared with B16-C215 cells genetically modified with the IL-18 gene, coated with the fusion protein of SEA and the Fab region of C215 mAb (C215Fab-SEA) which specifically binds to the C215 antigen and then irradiated. C57BL/6 mice were vaccinated with IL-18 gene-modified, C215Fab-SEA-coated B16-C215 cells followed by tumor challenge. Tumor growth and survival time were observed. The expansion of CD4+, CD8+ cells in lymphocytes derived from draining lymph node was detected by FACS. Induction of CTL activity by vaccination was measured by 51Cr release assay.

RESULTS

IL-18 gene-modified, C215Fab-SEA-coated B16-C215 cell vaccine effectively stimulated lymphocyte proliferation and CD4+, CD8+ cell expansion in vitro. It was more immunogenic than B16-C215 cells genetically modified with IL-18 gene alone or B16-C215 cells coated with C215Fab-SEA alone. Immunization of the mice with the manipulated vaccine elicited protective immunity against the following tumor challenge of parental B16-C215 and wild-type B16 cells. Significant expansion of CD4+, CD8+ T cells was observed in the draining lymph node of the immunized mice when compared with that in unvaccinated mice. Higher CTL activity was induced in vaccinated mice than that in unvaccinated mice.

CONCLUSION

Vaccination with IL-18 gene-modified, C215Fab-SEA-coated tumor cells elicited potent antitumor response through induction of tumor-specific immune response.

Silicon surfaces as electron acceptors: dative bonding of amines with Si(001) and Si(111) surfaces

The bonding of the trimethylamine (TMA) and dimethylamine (DMA) with crystalline silicon surfaces has been investigated using X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy, and density-functional computational methods. XPS spectra show that TMA forms stable dative-bonded adducts on both Si(001) and Si(111) surfaces that are characterized by very high N(1s) binding energies of 402.2 eV on Si(001) and 402.4 eV on Si(111). The highly ionic nature of these adducts is further evidenced by comparison with other charge-transfer complexes and through computational chemistry studies. The ability to form these highly ionic charge-transfer complexes between TMA and silicon surfaces stems from the ability to delocalize the donated electron density between different types of chemically distinct atoms within the surface unit cells. Corresponding studies of DMA on Si(001) show only dissociative adsorption via cleavage of the N-H bond. These results show that the unique geometric structures present on silicon surfaces permit silicon atoms to act as excellent electron acceptors.

Intron distribution difference for 276 ancient and 131 modern genes suggests the existence of ancient introns

o introns delineate elements of protein tertiary structure? This issue is crucial to the debate about the role and origin of introns. We present an analysis of the full set of proteins with known three-dimensional structures that have homologs with intron positions recorded in GenBank. A computer program was generated that maps on a reference sequence the positions of all introns in homologous genes. We have applied this program to a set of 665 nonredundant protein sequences with defined three-dimensional structures in the Protein Data Bank (PDB), which yielded 8,217 introns in 407 proteins. For the subset of proteins corresponding to ancient conserved regions (ACR), we find that there is a correlation of phase-zero introns with the boundary regions of modules and no correlation for the phase-one and phase-two positions. However, for a subset of proteins without prokaryotic counterparts (131 non-ACR proteins), a set of presumably modern proteins (or proteins that have diverged extremely far from any ancestral form), we do not find any correlation of phase-zero intron positions with three-dimensional structure. Furthermore, we find an anticorrelation of phase-one intron positions with module boundaries: they actually have a preference for the interior of modules. This finding is explicable as a preference for phase-one introns to lie in glycines, between G/G sequences, the preference for glycines being anticorrelated with the three-dimensional modules. We interpret this anticorrelation as a sign that a number of phase-one introns, and hence many modern introns, have been inserted into G/G "protosplice" sequences.

Cloning and characterization of a novel zinc finger protein (MDZF) that is associated with monocytic differentiation of acute promyelocytic leukemia cells

AIM

To study the characteristics of a novel zinc finger protein designated as monocytic differentiation-associated zinc finger protein (MDZF) and its role in the differentiation of leukemia cells.

METHODS

The mRNA expression of MDZF in tissues and cells was analyzed by Northern blot and RT-PCR. Polyclonal antibodies against the N terminus of MDZF were used to analyze protein expression in hematopoietic cell lines and subcellular location of MDZF in promyelocytic NB4 cells. The NB4 cells treated with TPA or ATRA at different intervals were harvested and then the expression level of MDZF protein was determined by Western blot.

RESULT

A full-length cDNA was successfully identified from a human monocyte-derived dendritic cell cDNA library which encodes 610 amino acids with eight C2H2 zinc finger motifs and one POZ domain. It was located on chromosome 3 according to the genome database. This novel zinc finger protein was designated as MDZF. One transcript isoform of MDZF was also cloned by RT-PCR. Northern blot showed that MDZF mRNA was restrictedly expressed in heart, skeleton muscle, kidney, liver, and placenta. MDZF protein was expressed in all hematopoietic cell lines examined. Immunoblotting and confocal analysis indicated a dominant cytoplasmic location of MDZF in NB4 cells. Furthermore, after NB4 cells were treated with TPA for 48 h and differentiated into monocytes, MDZF expression increased fivefold in the NB4 cells, but no effect was observed in NB4 cells treated with ATRA.

CONCLUSION

A novel zinc finger protein MDZF was cloned. MDZF is upregulated in monocytic, but not granulocytic, differentiation of NB4 acute promyelocytic leukemia cells. MDZF may be a candidate regulator of monocytic differentiation.

[Percutaneous testicular sperm aspiration and intracytoplasmic sperm injection in the treatment of severe male infertility]

OBJECTIVE

To investigate the efficacy of intracytoplasmic sperm injection (ICSI) combined with percutaneous testicular sperm aspiration (PTSA) in the treatment of severe male infertility.

METHODS

From October 1998 to December 2000, 162 couples were enrolled, and ICSI and PTSA were adopted. Ovarian stimulation was achieved by the short protocol. All metaphase II (M II) oocytes were selected for ICSI.

RESULTS

1,517 M II oocytes were injected in 185 cycles, 990 fertilized (65.3%), and 152 embryo implanted. 54 couples achieved clinical pregnancy (35.5%).

CONCLUSION

PTSA combined with ICSI is a rapid, convenient, painless and effective approach for the treatment of severe male infertility.

[Reconstruction of heel: long-term follow up of 12 cases]

OBJECTIVE

To study long-term follow up result of fibula transplantation to reconstruct partial or complete defect of the heel.

METHODS

Heel defects were reconstructed by means of reverse transferring of combined vascular pedicled fibulaflap. The calcaneus was repaired by two segments of the fibula. Skin defects were covered by skin flap, and sensation was restored by anastomosing the sural nerve and medial pedal nerve. The residual cavity was filled by muscles surrounding the fibula to reconstruct the appearance of foot.

RESULTS

Four patients with complete heel defect and 8 with partial defect were operated on successfully. Two to 13 years(average 5.2 years) follow-up showed that the function and appearance of foot were normal and adaptive changes happened in the tissue of foot. The fibula was getting into a real cal caneous gradually. Besides this, the skin was thickened and the sensation was restored with the two-point discrimination of 0.8 to 3.0 cm. All patients resumed physical work. Comprehensive evaluation revealed that 11 patients were excellent and 1 was good in their functional recovery.

CONCLUSION

The results suggested that this operation is ideal for reconstructing heel defect. All kinds of tissues in heel can be reconstructed and more satisfactory function and appearance can be obtained through adaptive heel reshaping along with long-term walk.