Self-organization of supramolecular helical dendrimers into complex electronic materials

The discovery of electrically conducting organic crystals and polymers has widened the range of potential optoelectronic materials, provided these exhibit sufficiently high charge carrier mobilities and are easy to make and process. Organic single crystals have high charge carrier mobilities but are usually impractical, whereas polymers have good processability but low mobilities. Liquid crystals exhibit mobilities approaching those of single crystals and are suitable for applications, but demanding fabrication and processing methods limit their use. Here we show that the self-assembly of fluorinated tapered dendrons can drive the formation of supramolecular liquid crystals with promising optoelectronic properties from a wide range of organic materials. We find that attaching conducting organic donor or acceptor groups to the apex of the dendrons leads to supramolecular nanometre-scale columns that contain in their cores pi-stacks of donors, acceptors or donor-acceptor complexes exhibiting high charge carrier mobilities. When we use functionalized dendrons and amorphous polymers carrying compatible side groups, these co-assemble so that the polymer is incorporated in the centre of the columns through donor-acceptor interactions and exhibits enhanced charge carrier mobilities. We anticipate that this simple and versatile strategy for producing conductive pi-stacks of aromatic groups, surrounded by helical dendrons, will lead to a new class of supramolecular materials suitable for electronic and optoelectronic applications.

Transgenics in crops

With rapid world population growth and declining availability of fresh water and arable land, a new technology is urgently needed to enhance agricultural productivity. Recent discoveries in the field of crop transgenics clearly demonstrate the great potential of this technology for increasing food production and improving food quality while preserving the environment for future generations. In this review, we briefly discuss some of the recent achievements in crop improvement that have been made using gene transfer technology.

Immunohistochemical detection of interferon-gamma-producing cells in granuloma formation of sporotrichosis

Granuloma formation is a common response in the skin infection of sporotrichosis. The involvement of interferon-gamma (IFN-gamma) and inducible nitric oxide synthase (iNOS) in the granuloma formation of sporotrichosis is less known. The aim of this study was to describe by immunohistochemistry the exact tissue distribution of IFN-gamma-positive cells and iNOS-positive cells in the granuloma of skin lesions from patients with sporotrichosis. Formalin-fixed paraffin-embedded skin biopsy sections from five patients were stained by immunohistochemical methods. Mixture of CD4-positive T cells and CD8-positive T cells were present in and around the granulomatous lesions. IFN-gamma-positive cells, like mononuclear lymphoid cells, were detected in the periphery of the granulomas in all samples. The pattern of IFN-gamma staining appeared to be a combination of intracellular staining in mononuclear lymphoid cells and extracellular deposition in the surrounding tissue. The majority of the epitheloid cells and multinucleated giant cells within the granuloma were identified by immunostaining for CD68. In contrast, no expression of immunoreactive iNOS was observed in those cells in all samples. These findings indicate that granulomas of sporotrichosis are coupled with Th1 response.

Poly(oxazolines)s with tapered minidendritic side groups. The simplest cylindrical models to investigate the formation of two-dimensional and three-dimensional order by direct visualization

The synthesis of 2-[3,4-bis(n-alkan-1-yloxy)phenyl]-2-oxazolines with alkan = octan, decan, dodecan, and tridecan is presented. Their living cationic ring opening polymerization produces cylindrical macromolecules that self-organize in a hexagonal columnar two-dimensional phase. The structural analysis of these polymers was carried out by a combination of techniques including differential scanning calorimetry, thermal optical polarized microscopy, X-ray diffraction, transmission electron microscopy, electron diffraction, scanning force microscopy, and atomic force microscopy (AFM). The diameter of these cylindrical macromolecules ranges from 33 to 44 A, and therefore they represent the simplest cylindrical macromolecules that can be directly visualized by AFM on a surface. Preliminary experiments have demonstrated the use of these cylindrical macromolecules as models to investigate the creation of two-dimensional and three-dimensional order via direct visualization and thus they represent the simplest nonbiological systems that mimic the role played by the complexes of nucleic acids with proteins in structural analysis by direct visualization.

Drosophila Lame duck, a novel member of the Gli superfamily, acts as a key regulator of myogenesis by controlling fusion-competent myoblast development

A hallmark of mature skeletal muscles is the presence of multinucleate muscle fibers. In Drosophila, the formation of muscle syncytia requires the cooperative participation of two types of myoblasts, founder cells and fusion-competent myoblasts. We show that a newly identified gene, lame duck (lmd), has an essential regulatory role in the specification and function of fusion-competent myoblasts. Embryos that lack lmd function show a loss of expression of two key differentiation and fusion genes, Mef2 and sticks-and-stones, in fusion-competent myoblasts and are completely devoid of multinucleate muscle fibers. By contrast, founder cells are specified and retain their capability to differentiate into mononucleate muscle cells. lmd encodes a novel member of the Gli superfamily of transcription factors and is expressed in fusion-competent myoblasts and their precursors in a Wingless- and Notch-dependent manner. The activity of the Lmd protein appears to be additionally controlled by its differential cytoplasmic versus nuclear localization. Results from an independent molecular screen for binding factors to a myoblast-specific Mef2 enhancer further demonstrate that Lmd is a direct transcriptional regulator of Mef2 in fusion-competent myoblasts.

Anti-thrombosis effect of paeoniflorin: evaluated in a photochemical reaction thrombosis model in vivo

In a photochemical reaction microvessel thrombosis model, the anti-thrombotic effect of PT was evaluated and the results showed that PF could significantly prolong thromobosis time. The anti-thrombotic effect of PF may relate to the inhibition of arachidonic acid metabolism, the increase of t-PA activity, and the protective effect against free radical.

Immunohistochemical localization of activated and mature CD83+ dendritic cells in granulomas of sporotrichosis

Dendritic cells (DC) are considered to be the most potent antigen-presenting cells (APC) and CD83 is expressed at a high level on immune-competent, activated and mature DC. In order to obtain insight into the immune response in sporotrichosis, we searched immunohistochemically for CD83+ DC in the granulomatous skin lesions of patients. A small but significant subpopulation of CD83+ DC (approximately 0.2 to 0.8% of inflammatory cells) was found. The most common distribution pattern of CD83+ DC was as clusters with mononuclear lymphoid cells within the granulomas. In addition, CD83+ DC were occasionally scattered around the granulomas. High-intensity staining of CD83 antigens was detected not only on the surface, but also in the cytoplasm of DC. No CD83+ DC were observed in the epidermis. A considerable amount of CD1a+ cells were detected in the epidermis, papillary dermis and around the granulomas, but CD1a+ cells were rarely found within the granulomas. There were large numbers of CD68+ monocytes and macrophages in the granulomas. These results indicate that activated and mature DC may play a role in the immune response to sporotrichosis.

Spontaneous regression of multiple seborrheic keratoses associated with nasal carcinoma

Seborrheic keratoses are very common epidermal neoplasms. We describe a patient with seborrheic keratoses presenting multifocal spontaneous regression. The patient had a concurrent nasal adenoid cystic carcinoma. The simultaneous regression of seborrheic keratoses ceased after total resection of the nasal carcinoma. Histological examination revealed marked infiltration of mononuclear cells, including CD4+, CD8+, CD68+ and cutaneous lymphocyte-associated antigen-positive cells, with profound accumulation of CD1a+ dendritic cells. Although apoptotic keratinocytes were not found in the lesional epidermis by histology, the majority of keratinocytes in the regressing seborrheic keratosis were positively stained by the TUNEL method. We postulate that the internal malignancy may induce spontaneous regression of seborrheic keratoses.

[Nutritional status assessment of patients with oral maxillofacial cancers]

OBJECTIVE

The objective of the study is to evaluate the nutritional status of patients with oral maxillofacial cancer.

METHODS

The nutritional status was evaluated using seven easily determined variables and multi-factor nutritional index in 50 hospitalized patients with oral maxillofacial cancer from 1990 to 1992.

RESULTS

Fifty-six percent of patients had protein-energy malnutrition. The high incidence of protein-energy malnutrition was found in those patients without adequate dietary intake.

CONCLUSION

Patients with oral maxillofacial cancer usually have protein-energy malnutrition. The reason is that the patients always have an inadequate dietary intake.

Definitive support by transmission electron microscopy, electron diffraction, and electron density maps for the formation of a BCC lattice from poly[N-[3,4,5-tris(n-dodecan-1-yloxy)benzoyl]ethyleneimine]

Transmission electron microscopy (TEM), electron diffraction (ED), and electron density maps (EDM) experiments were carried out on a poly[N-[3,4,5-tris(n-dodecan-1-yloxy)benzoyl]ethyleneimine] [poly[(3,4,5)12G1-Oxz]] with a degree of polymerization (DP) of 20. All experiments confirmed the thermotropic body-centered cubic (BCC) Im3m lattice suggested previously by X-ray diffraction (XRD) experiments. The unit cell parameter determined by ED at 23 degrees C is a = 42.4 A, in good agreement with XRD results which show a = 42.6 A after quenching from 70 degrees C. EDM of the XRD results confirm that the supramolecular minidendrimer obtained from poly[(3,4,5)12G1-Oxz] adopts a spherical "inverse micellar-like" structure, with the polyethyleneimine backbone and the aromatic groups microsegregated and concentrated in the corners and in the center of the cubic unit cell. A space-filling continuum is realized by the n-alkyl groups that radiate out of the aromatic core of the spherical dendrimer. This manuscript is only the second example of complete structural analysis of a lattice generated from supramolecular objects and complements the previous example reported from our laboratory on the Pm3n lattice.

Headless flies generated by developmental pathway interference

Ectopic expression of transcription factors in eye-antennal discs of Drosophila strongly interferes with their developmental program. Early ectopic expression in embryonic discs interferes with the developmental pathway primed by Eyeless and generates headless flies, which suggests that Eyeless is necessary for initiating cell proliferation and development of both the eye and antennal disc. Interference occurs through a block in the cell cycle that for some ectopic transcription factors is overcome by D-CycE or D-Myc. Late ectopic expression in cone cell precursors interferes with their differentiation. We propose that this developmental pathway interference is a general surveillance mechanism that eliminates most aberrations in the genetic program during development and evolution, and thus seriously restricts the pathways that evolution may take.

v-Ha-RaS oncogene upregulates the 92-kDa type IV collagenase (MMP-9) gene by increasing cellular superoxide production and activating NF-kappaB

Matrix metalloproteinase 9 (MMP-9) degrades basement membrane type IV collagen and is expressed during cellular migration and invasion. Here we show that v-Ha-Ras overexpression in rat kidney epithelial cells (REC) caused upregulation of MMP-9 gene expression in part by increasing cellular oxidant levels. v-Ha-Ras mediated the production of superoxide in Ras-transfected cells, which was associated with upregulated MMP-9 gene expression. Conversely, v-Ha-Ras expression decreased steady-state levels of mRNAs from tissue inhibitor of metalloproteinase 1 (TIMP-1), an inhibitor of MMP-9; plasminogen activator inhibitor 1 (PAI-1), which indirectly activates MMP-9 by increasing plasmin levels; and collagen IV, a substrate of MMP-9 and a major component of basement membrane. Gel mobility shift assays demonstrated that Ras overexpression enhanced NF-kappaB, but not AP-1 DNA binding to motifs in the MMP-9 gene promoter. The Ras-induced increase in NF-kappaB DNA binding could be inhibited by treatment with the antioxidants N-acetyl-L-cysteine and glutathione monoester, suggesting that intracellular oxidant levels can mediate MMP-9 transcription. Our findings identify an important role for Ras in the regulation of MMP-9 expression, and suggest that increased superoxide production can upregulate MMP-9 expression and thus contribute to malignant conversion.

SAG/ROC/Rbx/Hrt, a zinc RING finger gene family: molecular cloning, biochemical properties, and biological functions

The RING (really interesting new gene) finger proteins containing a characteristic C3HC4 or C3H2C3 motif appear to act as E3 ubiquitin ligase and play important roles in many processes, including cell-cycle progression, oncogenesis, signal transduction, and development. This review is focused on SAG/ROC/Rbx/Hrt (sensitive to apoptosis gene/regulator of cullins/RING box protein), an evolutionarily conserved RING finger family of proteins that were cloned recently by several independent laboratories through differential display, yeast two-hybrid screening, or biochemical purification. SAG/ROC2/Rbx2/Hrt2 is expressed in multiple mouse adult tissues, as well as early embryos. In humans, both SAG and ROC1 are ubiquitously expressed at a very high level in heart, skeletal muscle, and testis. Expression of both SAG and ROC1 is induced by mitogenic stimulation. SAG is also induced by a redox agent in cultured cells, as well as in in vivo mouse brain upon ischemia/reperfusion. Structurally, SAG consists of four exons and three introns with at least one splicing variant and two pseudogenes. The SAG gene promoter is enriched with multiple transcription factor binding sites. Biochemically, SAG binds to RNA, has metal-ion binding/free radical scavenging activity, and is redox-sensitive. Most importantly, like ROC1, SAG/ROC2 binds to cullins and acts as an essential component of E3 ubiquitin ligase. Biologically, SAG is a growth-essential gene in yeast. In mammalian cells, SAG protects apoptosis mainly through inhibition of cytochrome c release/caspase activation, and promotes growth under serum deprivation at least in part by inhibiting p27 accumulation. Blocking SAG expression via antisense transfection inhibits tumor cell growth. Thus, SAG appears to be a valid drug target for anticancer therapy.

Interleukin-8-positive neutrophils in psoriasis

We performed an immunohistochemical study to try to determine the cellular source of interleukin-8 (IL-8) in psoriatic skin lesions. IL-8 was positively stained in the vast majority of neutrophils but not in the mononuclear cells, macrophages, or keratinocytes. IL-8-positive neutrophils were seen both in Munro's microabcesses in cases of psoriasis vulgaris and in a small spongiform pustule and much larger macropustules of Kogoj in cases of pustular psoriasis. Some IL-8-positive neutrophils were observed in the upper dermis of pustular psoriasis. The staining was considered to be specific because it could be completely blocked by preabsorption with recombinant IL-8. In addition, stimulation of human neutrophils with lipopolysaccharide (LPS) or tumor necrosis factor-alpha (TNF-alpha) for 18 h induced IL-8 production in vitro. In our study, IL-8 was expressed in the neutrophils of psoriasis, suggesting that neutrophils are one of the sources of IL-8 in psoriasis. The expression of IL-8 and the influx of neutrophils led us to speculate that the IL-8 autocrine and/or paracrine system functions in the formation of the microabcesses and pustules in proriasis.

Limonoids from Citrus sudachi

Four new limonoid derivatives, 1-O-methylichangensin (1), sudachinoid A (2), B (3), and C (4) were isolated from the seeds of Citrus sudachi, together with the known compounds ichangensin, obacunone, obacunoic acid and limonin, and the structures of the new compounds were elucidated based on spectroscopic and chemical evidence.

Immunosuppressive sesquiterpene alkaloids from Tripterygium wilfordii

Nine new sesquiterpene pyridine alkaloids [wilfornines A (1), B (2), C (3), D (4), E (5), F (8), and G (9); wilfordinines I (6) and J (7)] and six known compounds (10-15) were isolated from a clinically used extract (T(II)) of Tripterygium wilfordii. The structures of 1-9 were elucidated by spectroscopic and chemical methods. The inhibitory effects on cytokine production of 1-3 and several related compounds were evaluated. Compounds 10 and 14 showed significant inhibitory effects on cytokine production.

Elevated expression of SAG/ROC2/Rbx2/Hrt2 in human colon carcinomas: SAG does not induce neoplastic transformation, but antisense SAG transfection inhibits tumor cell growth

Sensitive-to-apoptosis gene (SAG)/regulator of cullins (ROC)2/Rbx2/Hrt2 is a newly identified component of SCF E3 ubiquitin ligase that controls cell-cycle progression by promoting ubiquitination and degradation of cell-cycle inhibitors. We recently found that SAG protects cells from apoptosis induced by redox agents, promotes S-phase entry and cell growth under serum starvation, and is required for yeast growth. In the present study, we report that the SAG protein level was elevated in six of 10 human colon carcinoma tissues (60%) as compared with adjacent normal tissues from the same patient. SAG overexpression in preneoplastic cells in a JB6 tumor promotion-and-progression model did not induce neoplastic transformation, and SAG overexpression in NIH/3T3 cells did not induce transforming foci formation, suggesting that SAG is not a dominant oncogene. However, when DLD-1 human colon carcinoma cells were transfected with antisense SAG, monolayer growth was significantly inhibited, as shown by a decreased number of stable colonies in the plate after normalization with transfection efficiency. Stable clones that expressed antisense SAG showed a 50% decrease in their ability to form colonies when grown in soft agar versus clones that did not express antisense SAG. We found an inverse correlation in four of 10 tumors between the levels of SAG and p27, a cyclin-dependent kinase inhibitor. We concluded that SAG is not causally related to cellular transformation, but its overexpression may be important for the maintenance of tumor cell phenotype. Therefore, targeting SAG expression may have therapeutic value in cancer treatment. Mol. Carcinog. 30:62-70, 2001.

Immunohistochemical detection of interferon-gamma-producing cells in dermatophytosis

Skin lesions of dermatophytosis are thought to be a result of a T cell-dependent inflammatory response that is mediated by various cytokines. We examined whether IFN-gamma-positive cells (as expression of Th1 response) were present in the skin lesions of dermatophytosis in situ by immunohistochemical techniques. Mixtures of CD4-positive T cells and CD8-positive T cells were found to be present in the dermal infiltrates of the lesions. Considerable numbers of CD1a-positive cells were detected in the upper dermis and epidermis. A marked accumulation of CD68-positive cells was found in the upper dermis. IFN-gamma-positive cells were present in the upper dermis of the lesions. The pattern of IFN-gamma staining appeared to be intracellular in mononuclear lymphoid cells. The staining was considered to be highly specific because it could be completely blocked by preabsorption with recombinant IFN-gamma. Our data support the hypothesis that the skin lesions of dermatophytosis may be associated with a Th1 response. Th1 response, which is characterized by IFN-gamma release, is thought to be involved in the host defense against dermatophytes and to reflect cutaneous reaction in dermatophytosis.

[Applied researches on polylactide internal fixation devices]

Nowadays, more and more basic and clinical researches on polylactide internal fixators were carried out in China. In this paper are reviewed the researches of polylactide acid(PLA), including its physical and chemical characters, biodegradation, absorption and mechanical properties, effects on fracture healing, and clinical application. Some problems that have not been solved are high-lighted and discussed. Also dealt with are some researches of PLA in future.

[Dynamic ECG Review & Analysis Workstation]

The integrated management and remote application of dynamic ECG data is the future of the Holter System. This article introduces a kind of Dynamic ECG Review & Analysis Workstation that includes the function of integrated management and network. It has solved well the problems of common usage, archiving, total ECG analysis and remote transmission which exist in the traditional ECG Review & Analysis Systems.

[Buccal swab: a convenient source of DNA for analysis of IL-1 gene polymorphisms]

OBJECTIVE

PCR-RFLP based techniques have become standard procedures for gene polymorphism screening. Peripheral venous blood is currently the most commonly employed source of DNA for human genome analysis. However, it has many practical disadvantage and inherent limitations to use blood as DNA source. Blood sampling is invasive, painful and involves a potential risk of contamination with hepatitis. The classic procedure to extract genomic DNA from whole blood is phenol/chloroform technique, which is relative complicated and time consuming. Therefore, this study was performed to try an alternative instead of using blood as DNA source for gene polymorphism analysis.

METHODS

Four methods were employed to obtain DNA from the same subject including DNA from venous blood through phenol/chloroform extraction, DNA from dried blood spot through Chelex 100 technique, DNA from buccal swab through Chelex 100 technique and the dried blood spot directly as DNA template for PCR. Then, these various forms of DNA were used in PCR RFLP procedure to analyze IL-1 gene polymorphisms, and their specificity and sensitivity were evaluated.

RESULTS

Our results indicate that both the buccal swab and the blood based assays reached complete concordance in typing the IL-1 gene polymorphisms, while the Chelex 100 procedure for extracting DNA from buccal swab is much simpler and more rapid. It is non-invasive to get buccal swab. The amount of DNA obtained through one buccal swab is 63.8 micrograms +/- 18.7 micrograms, which is enough for 10 PCR reactions.

CONCLUSION

Buccal swab appears to be an excellent source of DNA for detection of polymorphisms of human IL-1 gene.

Determination of synthesized alpha-vitamin E by micellar electrokinetic chromatography

We developed a micellar electrokinetic chromatography method (MEKC) for the direct determination of the content of synthesized alpha-vitamin E. It was found that under the optimum separation conditions 7 mM borate + 14 mM phosphate + 15 mM sodium dodecyl sulfate (SDS) + 10 mM sodium cholate (NaCh) + 8% acetonitrile (pH 9.2) with UV detection wavelength at 214 nm, 16 kV constant voltage, and 26 degrees C constant temperature, alpha-vitamin E and its isomers can be baseline separated and alpha-vitamin E was quantitatively analyzed. In addition, the sample recovery, the limit of detection and the repeatability of the method were investigated. The influence of various parameters on the separation such as SDS concentration, NaCh concentration, buffer pH and acetonitrile percentage were also discussed.

Promotion of S-phase entry and cell growth under serum starvation by SAG/ROC2/Rbx2/Hrt2, an E3 ubiquitin ligase component: association with inhibition of p27 accumulation

The sensitive-to-apoptosis gene (SAG) was initially identified as a redox-inducible, apoptosis-protective protein and subsequently found to be the second family member of regulator of cullins (ROC)/RING box protein (Rbx)/Hrt, which acts as a component of E3 ubiquitin ligase. We report here that SAG promoted cell growth under serum starvation. Microinjection of SAG mRNA into quiescent NIH/3T3 cells induced S-phase entry as determined by [(3)H]-thymidine incorporation. Likewise, overexpression of SAG by either adenovirus infection of immortalized human epidermal keratinocytes (Rhek-1) or DNA transfection of SY5Y human neuroblastoma cells induced cell proliferation under serum starvation. Because cyclin-dependent kinase inhibitors (CKIs), including p21, p27, and p57, are degraded through the ubiquitin pathway, we tested whether SAG-induced cell growth is associated with CKI degradation. Although there was no significant difference in the levels of p21 and p57 between the vector controls and SAG-overexpressing cells, serum starvation induced 10- to 18-fold accumulation of p27 in control Rhek-1 cells. Accumulation of p27 was remarkably inhibited (only 2 to 5-fold) in SAG-infected cells. Inhibition of p27 accumulation was also observed in stably SAG-overexpressing SY5Y cells. Significantly, SAG-associated inhibition of p27 accumulation was largely abolished by the treatment with a proteasome inhibitor. In vivo binding of SAG and Skp2, an F-box protein that promotes p27 ubiquitination, was detected, and the binding was enhanced in SAG-overexpressing cells grown under serum starvation. Thus, SAG-induced growth with serum withdrawal appears to be associated with SAG-mediated p27 degradation. Mol. Carcinog. 30:37-46, 2001.

[Changes of hepatic energy metabolism following partial hepatopetal blood occlusion]

OBJECTIVE

To evaluate the changes of hepatic energy metabolism by temporary occlusion of partial hepatopetal blood.

METHODS

The animal mode of partial hepatopetal blood occlusion (PBO) was established without portal stasis. The hepatic energy metabolism parameters including adenosine triphosphate, respiratory control ratio, P/O ratio, and arterial ketone bodies ratio were studied following 30 min ischemia or 1, 6, and 24 h of reperfusion. The total hepatopetal blood occlusion (TBO) and sham groups served as control.

RESULTS

The parameters of hepatic motochondrial function reflecting hepatic damage to ischemia-reperfusion showed different in PBO comparing with TBO group. The functional lesion was restored progressively in PBO-30 min group, but it was maintained low level in TBO-30 min group.

CONCLUSION

The results suggest that it is beneficial to restoration of the hepatic energy metabolism in the ischemia-reperfusion injury by partial hepatopetal blood occlusion.

CD1a+, CD3+, CD4+, CD8+, CD68+ and cutaneous lymphocyte-associated antigen-positive cells in Bowen's disease

BACKGROUND

Bowen's disease (BD) is a squamous cell carcinoma in situ that rarely invades into the underlying dermis. However, little is known about its immunohistology. Objectives To evaluate the relationship between the cytological properties of the tumour cells in BD and the host immune response.

METHODS

We examined the expression of p53, proliferating cell nuclear antigen (PCNA) and Ki67 antigen, and the number of mitotic cells, together with the number of intratumoral and dermal infiltrating CD1a+, CD3+, CD4+, CD8+, CD68+ and cutaneous lymphocyte-associated antigen (CLA)+ cells in 18 cases of genital BD.

RESULTS

When compared with normal genital skin (n = 10), there was a significantly higher number of mitotic cells as well as higher expression of p53+, PCNA+ and Ki67+ cells in BD. There was significant mutual correlation between CD3+, CD4+ and CD68+ cells in the tumoral epidermis. The number of CD1a+ Langerhans cells significantly decreased in BD epidermis; however, dermal CD1a+ cells were increased. Interestingly, numbers of dermal CD1a+ cells significantly correlated with those of intratumoral CD3+, CD4+ and CD68+ cells. In situ hybridization for human papillomavirus (HPV) demonstrated that HPV-infected BD had significantly less infiltration of intratumoral CD3+ cells and CLA+ cells.

CONCLUSIONS

The present data suggest that dermal CD1a+ cells may participate in the immune surveillance and that HPV infection may interfere with the intratumoral infiltration of CLA+ cells in BD.

[The effect of polylactide screws on fracture healing]

This experiment aimed at investigating the effect of a kind of home-bred poly-DL-lactide screws on fracture healing. An operation was performed so as to make bilateral lateral condylar fractures of the femur in 8 dogs. The left sides were fixed with 2 home-bred PDLLA(Mv = 43 x 10(4)) screws, and the contralateral sides were fixed with 2 metalic screws to be used as controls. The animals were sacrificed at 2, 4, 8, and 12 weeks after surgery. Optic microscopy and SEM photography were done. The results of optic microscopy showed that fibrous callus formed already in both groups by 2 weeks after surgery, and bilateral fractures united uneventfully by 12 weeks. Although the course of fracture healing in experimental group was slower than that in control group, the osteogenesis in experimental group appeared to be normal. The SEM examination demonstrated that collagenous fibers arranged regularly and calcified normally in both groups at 12 weeks. And many square and rhomboid granules produced from the degradation of PDLLA material were found in experimental group at 12 weeks. Therefore, it is suggested that this kind of home-bred PDLLA screws should be applicable to fractures where the tissues are rich in blood supply.

Combinatorial signaling in the specification of unique cell fates

How multifunctional signals combine to specify unique cell fates during pattern formation is not well understood. Here, we demonstrate that together with the transcription factor Lozenge, the nuclear effectors of the EGFR and Notch signaling pathways directly regulate D-Pax2 transcription in cone cells of the Drosophila eye disc. Moreover, the specificity of D-Pax2 expression can be altered upon genetic manipulation of these inputs. Thus, a relatively small number of temporally and spatially controlled signals received by a set of pluripotent cells can create the unique combinations of activated transcription factors required to regulate target genes and ultimately specify distinct cell fates within this group. We expect that similar mechanisms may specify pattern formation in vertebrate developmental systems that involve intercellular communication.

Yeast homolog of human SAG/ROC2/Rbx2/Hrt2 is essential for cell growth, but not for germination: chip profiling implicates its role in cell cycle regulation

In an attempt to understand the signaling pathway mediating redox-induced apoptosis, we cloned SAG, an evolutionarily conserved zinc RING finger gene that, when overexpressed, protects cells from apoptosis induced by redox agents. Here we report functional characterization of SAG by the use of yeast genetics approach. Targeted disruption of ySAG, yeast homolog of human SAG, and subsequent tetrad analysis revealed that ySAG is required for yeast viability. Complementation experiment showed that the lethal phenotype induced by the ySAG deletion is fully rescued by wildtype SAG, but not by several hSAG mutants. Complementation experiment has also confirmed that ySAG is essential for normal vegetative growth, rather than being required for sporulation. Furthermore, cell death induced by SAG deletion was accompanied by cell enlargement and abnormal cell cycle profiling with an increased DNA content. Importantly, SAG was found to be the second family member of Rbx (RING box protein) or ROC (Regulator of cullins) or Hrt that is a component of SCF E3 ubiquitin ligase. Indeed, like ROC1/Rbx1/Hrt1, SAG binds to Cul1 and SAG-Cul1 complex has ubiquitin ligase activity to promote poly-ubiquitination of E2/Cdc34. This ligase activity is required for complementation of death phenotype induced by ySAG disruption. Finally, chip profiling of the entire yeast genome revealed induction of several G1/S as well as G2/M checkpoint control genes upon SAG withdrawal. Thus, SAG appears to control cell cycle progression in yeast by promoting ubiquitination and degradation of cell cycle regulatory proteins. Oncogene (2000) 19, 2855 - 2866

Sterols and inhibitors of sterol transport modulate the degradation and secretion of macrophage ApoE: requirement for the C-terminal domain

Macrophage-derived apoE, produced in the vessel wall, may have important effects during atherogenesis. The production of apoE by macrophages can be regulated at a transcriptional level by cellular differentiation state, cytokines and sterol loading. In addition, there are post-transcriptional and post-translational loci for regulation. We have recently identified an intermediate density cell membrane fraction in which the degradation of apoE can be modulated by sterols. Suppressing degradation of apoE in this fraction by pre-incubating cells in sterols led to enhanced apoE secretion. In this report we demonstrate that the suppressive effect of sterols on the degradation of newly synthesized apoE in this fraction depends on the presence on its C-terminal domain, by studying a macrophage cell line transfected to express a mutant form of apoE in which amino acids beyond amino acid 202 were deleted. In addition, two modulators of cellular sterol transport, progesterone and U1866A, inhibited the degradation of full-length apoE. In contrast, incubation of cells in the acyl-CoA:cholesterol acyltransferase inhibitor S58035 did not influence apoE degradation. As would be predicted based on the results of degradation assays, U1866A, but not S58035, increased the secretion of apoE from a cell line transfected to constitutively express full-length apoE cDNA. The effect of U1866A on apoE degradation, like the effect of sterol, required the presence of the apoE C-terminal domain. Our results indicate that alteration of intracellular sterol homeostasis by pre-incubation in sterols or by drugs that modify the subcellular transport of sterol, modulates the susceptibility of apoE to degradation and that this modulation requires the presence of C-terminal lipid binding domains.

Triterpenoids from Tripterygium wilfordii

The extract (T(II)) of Tripterygium wilfordii Hook f. afforded four triterpenoids: wilforic acid D (3beta,24-epoxy-2alpha-hydroxy-24R*-ethoxy-29-friedelanoic acid); (E) 3beta,24-epoxy-2-oxo-3alpha-hydroxy-29-friedelanoic acid; (F) 2beta-hydroxy-3-oxo-friedelan-29-oic acid; 29-hydroxy-3-oxo-olean-12-en-28-oic acid and 17 known triterpenoids. Their structures were established on the basis of spectroscopic studies. In a bioactivity analysis, only the known dulcioic acid compound showed a significant inhibitory effect on cytokine production.

Binding of 14-3-3beta to the carboxyl terminus of Wee1 increases Wee1 stability, kinase activity, and G2-M cell population

Wee1 protein kinase plays an important regulatory role in cell cycle progression. It inhibits Cdc-2 activity by phosphorylating Tyr15 and arrests cells at G2-M phase. In an attempt to understand Wee1 regulation during cell cycle, yeast two-hybrid screening was used to identify Wee1-binding protein(s). Five of the eight positive clones identified encode 14-3-3beta. In vivo binding assay in 293 cells showed that both full-length and NH2-terminal truncated Wee1 bind with 14-3-3beta. The 14-3-3beta binding site was mapped to a COOH-terminal consensus motif, RSVSLT (codons 639 to 646). Binding with 14-3-3beta increases the protein level of full-length Wee1 but not of the truncated Wee1. Accompanying the protein level increases, the kinase activity of Wee1 also increases when coexpressed with 14-3-3beta. Increased Wee1 protein level/enzymatic activity is accountable, at least in part, to an increased Wee1 protein half-life when coexpressed with 14-3-3beta. The protein half-life of the NH2-terminal truncated Wee1 is much longer than that of the full-length protein and is not affected by 14-3-3beta cotransfection. Biologically, 14-3-3beta/Wee1 coexpression increases the cell population at G2-M phase. Thus, Wee1 binding with 14-3-3beta increases its biochemical activity as well as its biological function. The finding reveals a novel mechanism by which 14-3-3 regulates G2-M arrest and suggests that the NH2-terminal domain of Wee1 contains a negative regulatory sequence that determines Wee1 stability.

[Internal fixation with mini-titanium plate for midface fractures]

Thirty four patients with midface bone fractures were fixed by rigid internal fixation (RIF) with min-titanium plate. An optimum exposure is provided for the fracture sites of zygomatic, zygomatic arch, orbital floor and maxilla with the coronal incision and adjuvant incisions. The approach was of benefit to accurate anatomic reduction and fixation of the fracture segments. RIF with min-titanium plate provided three-dimensional stability. The fixation of zygomatic-frontal crevice and zygomatic maxillary crevice were the key for obtaining sufficient stability, and at least two fixation screws were required above zygomatic-frontal crevice.

Terpenoids from Tripterigyum hypoglaucum

Six terpenoids have been isolated from the root bark of Tripterygium hypoglaucum, along with 14 known compounds. The structures of the terpenoids were elucidated as 3,11,14-oxo-abieta-8,12-diene, 3beta-hydroxy-12,14-dimethoxyabieta-8,11,13-triene, 3beta-hydroxy-11alpha-ethoxyurs-12-ene, 3beta-hydroxy-11alpha-methoxyurs-12-ene, 3beta-hydroxy-11alpha-methoxyolean-12-ene-28-oic acid, and 1beta-benzoyl-8alpha-cinnamoyl-4alpha,5alpha- dihydroxydihydroagarofuran.

Sesquiterpene alkaloids from Tripterygium hypoglaucum and Tripterygium wilfordii: a new class of potent anti-HIV agents

Five new sesquiterpene pyridine alkaloids [triptonines A (1) and B (2), and wilfordinines A (3), B (4), and C (5)] and two known compounds (peritassine A and hypoglaunine C) were isolated from Tripterygium hypoglaucum and a clinically used extract of Tripterygium wilfordii. The structures of 1-5 were elucidated by spectroscopic methods. The anti-HIV activity of 1, 2, and several related compounds was evaluated. Triptonine B (2) demonstrated potent anti-HIV activity with an EC(50) value of <0.10 microg/mL and an in vitro therapeutic index value of >1000.

Coumarins and bicoumarin from Ferula sumbul: anti-HIV activity and inhibition of cytokine release

The methanol extract of the dried roots of Ferula sumbul afforded two furanocoumarin esters, fesumtuorin A, B, one bicoumarin, fesumtuorin C, five spirobicoumarins, fesumtuorin D, E, F, G and H, along with nineteen known coumarins. Their structures were established on the basis of spectroscopic studies. Some of the isolated compounds showed anti-HIV activity and very weak inhibition of cytokine release.

Immunosuppressive diterpenoids from Tripterygium wilfordii

A clinically used extract of Tripterygium wilfordii afforded three new diterpenoids-3beta,19-dihydroxyabieta-8,11,13-triene (triptobenzene L) (1); 12,19-dihydroxy-3-oxoabieta-8,11,13-triene (triptobenzene M) (2); and 19-hydroxy-3,7-dioxo-abieta-8,11, 13-triene (triptobenzene N) (3)-along with 14 known diterpenoids. The structures of 1-3 were established on the basis of spectroscopic studies. Of the known compounds, the stereochemistry at C-4 of triptonediol (4) was reassigned. Tripterifordin (8) and 13-epi-manoyl oxide-18-oic acid (9) showed significant inhibitory effects on cytokine production.

Apolipoprotein E-dependent cholesterol efflux from macrophages: kinetic study and divergent mechanisms for endogenous versus exogenous apolipoprotein E

In these studies, we have utilized a J774 macrophage model in order to compare phospholipid and cholesterol efflux kinetics in macrophage cells that do not express endogenous apoE to cells transfected to express physiologic levels of human apoE. This model was also used to compare the effect of exogenously added versus endogenously expressed apoE on cholesterol efflux kinetics from macrophages. ApoE expression increased free cholesterol and phospholipid efflux into the medium, but did not change the free cholesterol/phospholipid molar ratio of secreted lipids. Kinetic examination showed that free cholesterol and phospholipid appeared simultaneously in the medium, and that cholesterol loading widened the difference in the rate of cholesterol efflux between apoE-expressing and non-expressing macrophages. Addition of exogenous lipid-free apoE added to non-expressing cells, at a >2-fold higher medium concentration than that produced by endogenous expression, produced less cholesterol efflux than that observed from apoE-expressing cells. The addition of phosphatidylcholine liposomes substantially increased cholesterol efflux from apoE-expressing and non-expressing J774 cells. Addition of these liposomes eliminated the enhanced cholesterol efflux produced by addition of exogenous apoE. On the other hand, even in the presence of phosphatidylcholine liposomes, cholesterol efflux rates remained significantly higher from apoE-expressing macrophages than non-expressing cells. Similar results were obtained when efflux was studied in the presence of cyclodextrin. These results suggest that endogenous expression of apoE by macrophages alters cell cholesterol balance via mechanisms distinct from those utilized by the extracellular addition of apoE, and may involve intracellular or pericellular mechanisms.

[Implementation of gateway between WWW and DICOM]

This paper discusses the necessity of gateway between WWW and DICOM, shows the method of the implementation and the result. It brings forward a new way in which doctors interact with PACS and medical image device such as CT, MRI, ultrasonic, etc. It points out that the gateway between WWW and DICOM is a kind of transition between appropriative standard and general standard. This kind of transition will bring convenience to telemedicine information system and integrated medical information system.

[Study on the electrothermal tissue effects during transcervical resection of endometrium]

OBJECTIVE

To investigate the tissue electrothermal effects and to seek the appropriate setting of operative wattage during transcervical resection of endometrium (TCRE).

METHODS

The power setting were 60 W, 80 W, 100 W for cutting and 30 W, 60 W, 80 W, 100 W for coagulation when performing endometrial resection in vitro or in vivo with operating time 3-5 seconds or 6-8 seconds respectively. After operation the uterine specimens were stained by hemaloxylin-eosin, and respiratory enzyme dehydronicotinamide adenine dinucleotide phosphate diaphorase methods for evaluating the tissue damage.

RESULTS

(1) The depth of endometrial damage under cutting was considerably less severe than those under coagulation with the same power setting. (2) When the power of cutting and coagulation were 80 W, 100 W and 30 W, 60 W respectively and operating time prolonged more than 5 seconds, the thermal damage covered endometrium and 2-3 mm of myometrium in depth. (3) At such wattage and operating time the deepest destruction was only 16.27% of uterine wall.

CONCLUSION

(1) There is significant difference in the depth of thermal damage between cutting and coagulation during hysteros copic surgery. (2) The appropriate power setting should be 80-100 W for cutting and 30-60 W for coagulation.

Expression, purification, and biochemical characterization of SAG, a ring finger redox-sensitive protein

We recently reported the cloning and characterization of SAG (sensitive to apoptosis gene), a novel zinc RING finger protein, that is redox responsive and protects mammalian cells from apoptosis. Here we report the expression, purification, and biochemical characterization of SAG. Bacterially expressed SAG is brown in color and dithiothreitol (DTT)-sensitive. SAG forms large oligomers without DTT that can be reduced into a monomer in the presence of DTT. These features help us to purify SAG using the chromatography with or without DTT. Likewise, purified SAG is redox sensitive. Upon H2O2 exposure, SAG forms oligomers as well as monomer doublets due to the formation of the inter- or intramolecular disulfide bonds, respectively. This process can be reversed by DTT or prevented by pretreatment with the alkylating reagent, N-ethylmaleimide (NEM). Although SAG contains two putative heme-binding sites and a RING finger domain, the protein appears not to bind with heme and to lack transcription factor activity as determined in a Gal4-fusion/transactivation assay. Wildtype, but not RING finger domain-disrupted SAG mutants, prevents copper-induced lipid peroxidation. These results, along with our previous observations, suggest that SAG is an intracellular antioxidant molecule that may act as a redox sensor to buffer oxidative-stress induced damage.

An essential role for the Drosophila Pax2 homolog in the differentiation of adult sensory organs

The adult peripheral nervous system of Drosophila includes a complex array of mechanosensory organs (bristles) that cover much of the body surface of the fly. The four cells (shaft, socket, sheath, and neuron) which compose each of these organs adopt distinct fates as a result of cell-cell signaling via the Notch (N) pathway. However, the specific mechanisms by which these cells execute their conferred fates are not well understood. Here we show that D-Pax2, the Drosophila homolog of the vertebrate Pax2 gene, has an essential role in the differentiation of the shaft cell. In flies bearing strong loss-of-function mutations in the shaven function of D-Pax2, shaft structures specifically fail to develop. Consistent with this, we find that D-Pax2 protein is expressed in all cells of the bristle lineage during the mitotic (cell fate specification) phase of bristle development, but becomes sharply restricted to the shaft and sheath cells in the post-mitotic (differentiative) phase. Two lines of evidence described here indicate that D-Pax2 expression and function is at least in part downstream of cell fate specification mechanisms such as N signaling. First, we find that the lack of late D-Pax2 expression in the socket cell (the sister of the shaft cell) is controlled by N pathway activity; second, we find that loss of D-Pax2 function is epistatic to the socket-to-shaft cell fate transformation caused by reduced N signaling. Finally, we show that misexpression of D-Pax2 is sufficient to induce the production of ectopic shaft structures. From these results, we propose that D-Pax2 is a high-level transcriptional regulator of the shaft cell differentiation program, and acts downstream of the N signaling pathway as a specific link between cell fate determination and cell differentiation in the bristle lineage.

SAG, a novel zinc RING finger protein that protects cells from apoptosis induced by redox agents

SAG (sensitive to apoptosis gene) was cloned as an inducible gene by 1,10-phenanthroline (OP), a redox-sensitive compound and an apoptosis inducer. SAG encodes a novel zinc RING finger protein that consists of 113 amino acids with a calculated molecular mass of 12.6 kDa. SAG is highly conserved during evolution, with identities of 70% between human and Caenorhabditis elegans sequences and 55% between human and yeast sequences. In human tissues, SAG is ubiquitously expressed at high levels in skeletal muscles, heart, and testis. SAG is localized in both the cytoplasm and the nucleus of cells, and its gene was mapped to chromosome 3q22-24. Bacterially expressed and purified human SAG binds to zinc and copper metal ions and prevents lipid peroxidation induced by copper or a free radical generator. When overexpressed in several human cell lines, SAG protects cells from apoptosis induced by redox agents (the metal chelator OP and zinc or copper metal ions). Mechanistically, SAG appears to inhibit and/or delay metal ion-induced cytochrome c release and caspase activation. Thus, SAG is a cellular protective molecule that appears to act as an antioxidant to inhibit apoptosis induced by metal ions and reactive oxygen species.

[Effect of 15-methyl PGF2 alpha methyl ester combined with tyrosine hydrazide on early pregnancy in mice]

OBJECTIVE

To observe the effect of 15-methyl PGF2 alpha methyl ester (PG05) in combination with tyrosine hydrazide (TH) on early pregnancy in mice.

METHODS

The pregnancy rate of mice treated with PG05 and TH was counted and serum progesterone level was measured by RIA.

RESULTS

Administration of TH at 90 mg.kg.day-1 to mice on day 7-9 of gestation enhanced significantly the termination of early pregnancy induced by PG05 at 0.2 mg-1.kg-1 for 2 days. Serum progesterone level of mice treated with PG05 combined with TH was found to be markedly lower than that of animals given PG05 or TH alone. TH at 30 micrograms-1.ml-1 inhibited significantly the activity of 3 beta-HSD of luteal cells in rat. However, PG05 at 10 micrograms-1.ml-1 had no influence upon inhibitory effect of 3 beta-HSD activity induced by TH. TH at 150 mg-1.kg-1 for 3 days did not affect the progesterone receptor level of utering cytoplasma in pseudopregnant rats.

CONCLUSIONS

The inhibitory effect of TH on the production of progesterone may be the main mechanism to terminate early pregnancy when used synergically with PG05.

[Relationship between retinal and glomerular microvascular lesions in experimental diabetes in rat]

OBJECTIVE

To evaluate the relationship between diabetic retinopathy (DR) and diabetic nephropathy (DN).

METHODS

The thickness of retinal capillary basement membrane (RBM) and glomerular basement membrane (GBM) and their anionic sites were quantitatively analyzed by electron microscopy and immunohistochemical methods.

RESULTS

RBM and GBM became gradually thickened with the development of diabetes. The thickened basement membrane was accompanied with decrease of anionic sites in number.

CONCLUSION

DR and DN share partly the pathological process, and there are also some incoordinate phenomena in the microvascular lesion.

Combination of hysteroscopy and laparoscopy in gynecologic operation: an analysis of 65 cases

OBJECTIVE

To introduce the procedures, preliminary experience, and advantages of operation using combination of hysteroscopy and laparoscopy.

METHODS

Sixty-five women underwent transcervical resection of endometrium (11), myoma (38), polyp (2), septa (9), adhesion (1) or foreign body (4). All had the indications for simultaneous laparoscopic monitoring and operation. They were first diagnosed laparoscopically to decide the type of laparoscopic operation. Then they were treated hysteroscopically and finally received laparoscopic operation.

RESULTS

Laparoscopic examinations confirmed the original diagnoses, revealed the causes of pelvic pain in 8 patients, and detected ovarian cyst, endometriosis, and pelvic adhesion in 5. Two cases of uterine perforation were found by laparoscopic monitoring. Thirty laparoscopic operations included removal or puncture of ovarian cyst, lysis of adhesion, coagulation of endometriosis, Rubin's test, and partial salpingectomy. The postoperative course was smooth and the operative result was satisfactory.

CONCLUSIONS

Operations using combination of hysteroscopy and laparoscopy are safe and effective. They also reduce the pain, and save the time and money of patients. Laparoscopic monitoring may detect uterine perforation in time.

[Studies on analytical method for 10 drugs of abuse in urine using HPLC]

A systematic determination method for 10 drugs of abuse, morphine, codeine, 6-monoacetylmorphine, heroin, levorphanol, pethidine, ethylmorphine, anadol, pentazocine and ethamivan, using high performance liquid chromatography is described. Separation of the 10 drugs was achieved on a 25 cm x 4.6 mm ID, 10 microns Zorbax C8 column, using methanol--0.05 mol.L-1 KH2PO4--diethyl amine (27:73:0.5, pH 4) as mobile phase. Codeine was used as the interal standard. Calibration graphs were linear over the concentration range of 10-200 micrograms.ml-1 and regression equations showed correlation coefficients of greater than 0.999. Precision (RSD) were found to be better than 3% for each compound. Precision and linearity of the method are satisfactory for clinical toxicological applications. The extraction procedure yielded cleaner extracts. The recovery rates from urine were all above 87% without interference. This method is rapid, sensitive and specific.

shaven and sparkling are mutations in separate enhancers of the Drosophila Pax2 homolog

We have previously shown that the sparkling gene, which like mammalian Pax2 plays an important role in eye development, is encoded by the Drosophila homolog of Pax2. Here we demonstrate that D-Pax2 also encodes the shaven function, which is crucial during bristle development. Both sv and spa alleles, previously thought to represent different genes, are mutations in two widely separated enhancers of D-Pax2. The sv function of D-Pax2 acts in at least two distinct steps of mechanosensory bristle development: the specification of the alternative fate of shaft as opposed to socket cell, and later the differentiation of the shaft cell.

Solution structure of the RAIDD CARD and model for CARD/CARD interaction in caspase-2 and caspase-9 recruitment

Apoptosis requires recruitment of caspases by receptor-associated adaptors through homophilic interactions between the CARDs (caspase recruitment domains) of adaptor proteins and prodomains of caspases. We have solved the CARD structure of the RAIDD adaptor protein that recruits ICH-1/caspase-2. It consists of six tightly packed helices arranged in a topology homologous to the Fas death domain. The surface contains a basic and an acidic patch on opposite sides. This polarity is conserved in the ICH-1 CARD as indicated by homology modeling. Mutagenesis data suggest that these patches mediate CARD/CARD interaction between RAIDD and ICH-1. Subsequent modeling of the CARDs of Apaf-1 and caspase-9, as well as Ced-4 and Ced-3, showed that the basic/acidic surface polarity is highly conserved, suggesting a general mode for CARD/CARD interaction.