High-rate stormwater clarification with polymeric flocculant addition

Treatment of urban stormwater by clarification, with flocculant addition, was studied in Toronto, Canada using a pilot-scale clarifier with removable lamellar plates. Almost 90 stormwater runoff events were characterised at the study site and found fairly polluted. The previous research phase indicated good treatability of this stormwater by lamellar clarification with flocculant addition (total suspended solids, TSS, removal of 84%, at a surface load of 15 m/h), but there were concerns about cleaning plates after storm events. With the aid of numerical modelling, hydraulic improvements to the clarifier inlet zone were retrofitted in 2004 and permitted the removal of the lamellar pack without a loss in treatment efficiency. In the modified clarifier, a cationic polymeric flocculant dosage of 4 mg/L with conventional clarification provided a TSS removal of 77%, at surface loads up to 43 m/h. The use of the polymer did not increase the acute toxicity of the treated effluent. The clarifier sludge was severely polluted by several heavy metals and would require special disposal. The treatment process tested could be well applied in projects requiring intensive stormwater treatment at compact sites.

A combined linkage-physical map of the human genome

We have constructed de novo a high-resolution genetic map that includes the largest set, to our knowledge, of polymorphic markers (N=14,759) for which genotype data are publicly available; that combines genotype data from both the Centre d'Etude du Polymorphisme Humain (CEPH) and deCODE pedigrees; that incorporates single-nucleotide polymorphisms; and that also incorporates sequence-based positional information. The position of all markers on our map is corroborated by both genomic sequence and recombination-based data. This specific combination of features maximizes marker inclusion, coverage, and resolution, making this map uniquely suitable as a comprehensive resource for determining genetic map information (order and distances) for any large set of polymorphic markers.

Physical mapping of a rice lesion mimic gene, Spl1 , to a 70-kb segment of rice chromosome 12

The rice lesion mimic mutant spotted leaf 1 ( spl1) was first identified in the rice ( Oryza sativa) cultivar Asahi in 1965. This mutant displayed spontaneous disease-like lesions in the absence of any pathogen, and was found to confer resistance to multiple isolates of rice blast. We employed a map-based cloning strategy to localize the Spl1 gene. A total of ten cleaved amplified polymorphic sequence (CAPS) markers linked to the Spl1 gene were identified and mapped to an 8.5-cM region on chromosome 12. A high-resolution genetic map was developed using these ten CAPS markers and a segregating population consisting of 3202 individuals. A BAC contig containing four BAC clones was constructed, and Spl1 was localized to a 423-kb region. Seven spl1 mutants were obtained from the IR64 deletion mutant collection, and molecular analysis using these mutants delimited the Spl1 gene to a 70-kb interval, covered by two BAC clones. These results provide the basis for cloning this gene, which is involved in cell death and disease resistance in rice.

Aqueous and Micelle-bound Structural Characterization of the Epidermal Growth Factor Receptor Juxtamembrane Domain Containing Basolateral Sorting Motifs

The EGF receptor is the prototype for four highly related receptors constituting the ErbB family. The EGF receptor is normally targeted to the basolateral membrane in polarized epithelial cells, where it relays information from underlying tissues. Two basolateral sorting signals have been mapped to the cytoplasmic juxtamembrane region of the receptor, a dominant signal comprised of a polyproline core (667-PXXP) and a preceding basic residue (Arg662), and a consensus leucine-based signal (658-LL) responsible for residual sorting when the 667-PXXP signal is absent or defective. The goal of this study was to define the structure of these signals, and gain some insights into how these structures might be regulated by cellular microenvironment. Structural information was acquired for two peptides corresponding to EGF receptor residues Arg645 and Ala674 in aqueous solution or in the presence of membrane-mimicking dodecylphosphocholine micelles, using a variety of NMR and CD spectroscopic methods. Chemical shift data indicate that the 667-PXXP signal does not bind to the micelles and is in random coil state in both aqueous solution and a micellar environment, raising the possibility that 667-PXXP switches to an ordered structure during interaction with the basolateral sorting machinery. In contrast, the adjacent region including 658-LL does bind to micelles mediated by a highly positively charged region located between Arg645 and Arg656. The micelle-bound region also includes Thr654, a known substrate for PKC. This suggests a distinct mode of regulation for this signal involving membrane association and/or phosphorylation.

Ionic Pair Complexes with Well-Separated Columnar Stack Structure Based on [Pt(mnt)2]-Ions Showing Unusual Magnetic Transition: Syntheses, Crystal Structures, and Magnetic Properties

Three ion pair complexes, [4-R-benzylpyridinium][bis(maleodinitriledithiolato)platinum(III)] (abbreviated as [RBzPy][Pt(mnt)(2)]; R = Cl (1), Br (2), or NO(2) (3)), have been synthesized. The cations and anions stack into well-separated columns in the solid state, and the Pt(III) ions form a 1-D zigzag chain within a [Pt(mnt)(2)](-) column through Pt...S, S...S, and Pt...S...Pt interactions. The chain is uniform in 1 and 2, while it alternates in 3. Unusual magnetic phase transitions from paramagnetism to diamagnetism were observed in these three complexes at approximately 275 K for 1, approximately 269 K for 2, and approximately 184 K for 3. These phase transitions were also found in DSC measurements for 1 and 2. The overall magnetic behaviors for 1-3 indicate the presence of antiferromagnetic exchange interactions in the high-temperature phase and spin-gapped systems in the low-temperature phase. Below 50 K, 2 exhibits weak ferromagnetism. The spontaneous moments are nearly repressed by a field of 1.0 T. The crystal structure of 2 at 173 K reveals that there are two crystallographically independent [Pt(mnt)(2)](-) entries in an asymmetric unit. These two crystallographically independent [Pt(mnt)(2)](-) entries satisfy the spin-canting condition, and the EPR spectra measured at room temperature exhibit anisotropic character. Therefore, the weak ferromagnetic behavior in the low-temperature region for 2 can be attributed to the spin-canting phenomenon.

Putative SNP discovery in interspecific hybrids of catfish by comparative EST analysis

In this study, we identified putative SNP markers within genes by comparative analysis of expressed sequence tags (ESTs). Comparison of 849 ESTs from blue catfish (Ictalurus furcatus) with >11,000 ESTs from channel catfish (I. punctatus) deposited in GenBank resulted in the identification of 1020 putative SNPs within 161 genes, of which 145 were nuclear genes of known function. The observed frequency of SNPs within ESTs of the two closely related catfish species was 1.32 SNP per 100 bp. The majority of identified SNPs differed between the two species and, therefore, these SNPs are useful for mapping genes in channel catfish x blue catfish interspecific resource families. The SNPs that differed within species were also observed; these can be applied to genome scans in channel catfish resource families.

Isolation and characterization of rice mutants compromised in Xa21-mediated resistance to X. oryzae pv. oryzae

The rice gene, Xa21, confers resistance to diverse races of Xanthomonas oryzae pv. oryzae (Xoo) and encodes a receptor-like kinase with leucine-rich repeats in the extra-cellular domain. To identify genes essential for the function of the Xa21 gene, 4,500 IRBB21 ( Xa21 isogenic line in IR24 background) mutants, induced by diepoxybutane and fast neutrons, were screened against Philippine race six (PR6) Xoo for a change from resistance to susceptibility. From two greenhouse screens, 23 mutants were identified that had changed from resistant to fully (6) or partially (17) susceptible to PR6. All fully susceptible mutants carried rearrangements at the Xa21 locus as detected by PCR and Southern hybridization. For the partially susceptible mutants, no changes were detected at the Xa21 locus based on Southern and PCR analyses. However, two of these mutants were confirmed via genetic analysis to have mutations at the Xa21 locus. Partially susceptible mutants exhibited variation in level of susceptibility to different Xoo strains, suggesting that they may carry different mutations required for the Xa21-mediated resistance. The mutants identified in this study provide useful materials for dissecting the Xa21-mediated resistance pathway in rice.

Generation and flanking sequence analysis of a rice T-DNA tagged population

Insertional mutagenesis provides a rapid way to clone a mutated gene. Transfer DNA (T-DNA) of Agrobacterium tumefaciens has been proven to be a successful tool for gene discovery in Arabidopsis and rice ( Oryza sativa L. ssp. japonica). Here, we report the generation of 5,200 independent T-DNA tagged rice lines. The T-DNA insertion pattern in the rice genome was investigated, and an initial database was constructed based on T-DNA flanking sequences amplified from randomly selected T-DNA tagged rice lines using Thermal Asymmetric Interlaced PCR (TAIL-PCR). Of 361 T-DNA flanking sequences, 92 showed long T-DNA integration (T-DNA together with non-T-DNA). Another 55 sequences showed complex integration of T-DNA into the rice genome. Besides direct integration, filler sequences and microhomology (one to several nucleotides of homology) were observed between the T-DNA right border and other portions of the vector pCAMBIA1301 in transgenic rice. Preferential insertion of T-DNA into protein-coding regions of the rice genome was detected. Insertion sites mapped onto rice chromosomes were scattered in the genome. Some phenotypic mutants were observed in the T1 generation of the T-DNA tagged plants. Our mutant population will be useful for studying T-DNA integration patterns and for analyzing gene function in rice.

Development and characterization of simple sequence repeat (SSR) markers and their use in determining relationships among Lycopersicon esculentum cultivars

The simple sequence repeat (SSR) or microsatellite marker is currently the preferred molecular marker due to its highly desirable properties. The aim of this study was to develop and characterize more SSR markers because the number of SSR markers currently available in tomato is very limited. Five hundred DNA sequences of tomato were searched for SSRs and analyzed for the design of PCR primers. Of the 158 pairs of SSR primers screened against a set of 19 diverse tomato cultivars, 129 pairs produced the expected DNA fragments in their PCR products, and 65 of them were polymorphic with the polymorphism information content (PIC) ranging from 0.09 to 0.67. Among the polymorphic loci, 2-6 SSR alleles were detected for each locus with an average of 2.7 alleles per locus; 49.2% of these loci had two alleles and 33.8% had three alleles. The vast majority (93.8%) of the microsatellite loci contained di- or tri-nucleotide repeats and only 6.2% had tetra- and penta-nucleotide repeats. It was also found that TA/AT was the most frequent type of repeat, and the polymorphism information content (PIC) was positively correlated with the number of repeats. The set of 19 tomato cultivars were clustered based on the banding patterns generated by the 65 polymorphic SSR loci. Since the markers developed in this study are primarily from expressed sequences, they can be used not only for molecular mapping, cultivar identification and marker-assisted selection, but for identifying gene-trait relations in tomato.

Spatial variation of plasma flow in the oxazolone-stimulated microcirculation

INTRODUCTION

In cutaneous lymphocytic inflammation, enhanced regional blood flow is suggested by persistent erythema and warmth. Direct assessment of the microcirculation, however, has been limited by tissue edema and skin thickness.

METHODS

To assess the microcirculatory adaptations to the epicutaneous antigen oxazolone, we studied the first pass kinetics and microvascular topography of the inflammatory skin microcirculation using a specially adapted epi-illumination intravital microscopy system. The fluorescence intravital videomicroscopy and streaming image acquisition of fluorescein-labeled dextran (approximately 500,000 MW) injections were used to assess changes in plasma flow.

RESULTS

Direct plasma tracer injections of both the oxazolone-stimulated and control microcirculation demonstrated comparable transit times (leading edge and intensity-weighted peak times) from the carotid artery to the superficial vascular plexus (p > 0.05). In contrast to transit times, continuous infusion of the plasma tracer demonstrated a significant increase in the delivery of the fluorescein-labeled dextran to the oxazolone-stimulated microcirculation. Quantitative morphometry of intravital microscopic images demonstrated a 2.2-fold increase in the mean diameter of vessels in the superficial vascular plexus (p < 0.01). Further, fluorescence intensity mapping indicated that the increase was associated with increased perfusion of focal regions of the superficial vascular plexus (p < 0.001).

CONCLUSIONS

These results indicate that the oxazolone-stimulated adaptations of the inflammatory microcirculation include both microvascular dilatation and the redistribution of plasma flow.

Effect of a lipopolysaccharide from E. coli on the proliferation of fibroblasts and keratinocytes in vitro

Studies previously conducted in our laboratory have shown that an extract from the leaves of Chromo-laena odorata is mitogenic for human skin fibroblasts and keratinocytes. However, lipopolysaccharides, sometimes present in plant extracts, can also play a role in cell growth and might have been responsible for or contributed to the mitogenic activity observed. The present study aimed to investigate whether a lipopolysaccharide would have any effect on the proliferation of human fibroblasts and keratinocytes. Cells were seeded in 96-well plates and concentrations from 0.0 to 5.0 microg/mL of lipopolysaccharide in basal or growth medium were added. Cell growth was determined over a period of 10 days using a colorimetric assay. Lipopolysaccharide at concentrations between 0.05 microg/mL and 0.5 microg/mL in the growth medium significantly stimulated fibroblast proliferation after incubation for more than 6 days. In basal medium, more than 8 days of incubation was needed for significant stimulation of growth. Lipopolysaccharide stimulation of keratinocytes was evident at 0.5 microg/mL by day 3 in basal medium and by day 5 in growth medium. Although the lipopolysaccharide did stimulate cell growth it did so only at higher concentrations than were present in our plant extracts and to a lesser degree.

Prevalence of vaccine-induced escape mutants of hepatitis B virus in the adult population in China: a prospective study in 176 restaurant employees

BACKGROUND AND AIM

Hepatitis B virus (HBV) variants with mutations in the S gene would pose a substantial risk to the community as current HBV vaccines are not effective in preventing infection with them. The majority of such vaccine escape mutants so far reported have been found while studying vertical transmission of HBV; the vaccine failure rate in connection with vaccine escape mutants in adults is not clear at the moment. The purpose of this study was to evaluate the efficacy of immunization against HBV in the adult population by analysis using polymerase chain reaction (PCR) to detect HBV-DNA, and also to elucidate the type of mutation encountered in vaccine failure cases.

METHOD

A total of 176 adult restaurant employees in China, who had been vaccinated according to the food epidemic law, were enrolled in a standard vaccination program. Their serum HBV-DNA was determined before and 1 year after the completion of the vaccination program. In those infected with HBV, despite having received the HBV vaccine, direct sequencing within the S gene of the amplified samples was conducted.

RESULTS

Although only two cases were found to be hepatitis B surface antigen (HBsAg) positive 1 year after the completion of the vaccination program, six subjects (3.4%) were found to be HBV-DNA positive assessed by a nested PCR. Four out of these six cases had a point mutation within the 'a' determinant; they were Gly-145-Ala, and Ile/Thr-126-Asn/Ser.

CONCLUSION

The HBV vaccine failure rate assessed by using PCR analysis was 3.4% (six of 176) in the Chinese adult population undergoing the HBV vaccination program. Hepatitis B virus variants with missense mutation within the 'a' determinant were responsible in most cases.

Manipulating the direction of electron transfer in the bacterial reaction center by swapping Phe for Tyr near BChl(M) (L181) and Tyr for Phe near BChl(L) (M208)

We have investigated the primary charge separation processes in Rb. capsulatus reaction centers (RCs) bearing the mutations Phe(L181) --> Tyr, Tyr(M208) --> Phe, and Leu(M212) --> His. In the YFH mutant, decay of the excited primary electron donor P occurs with an 11 +/- 2 ps time constant and is trifurcated to give (1) internal conversion to the ground state ( approximately 10% yield), (2) charge separation to the L side of the RC ( approximately 60% yield), and (3) electron transfer to the M-side bacteriopheophytin BPh(M) ( approximately 30% yield). These results relate previous work in which the ionizable residues Lys (at L178) and Asp (at M201) have been used to facilitate charge separation to the M side of the RC, and the widely studied L181 and M208 mutants. One conclusion that comes from this work is that the Tyr (M208) --> Phe and Gly(M201) --> Asp mutations near the L-side bacteriochlorophyll (BChl(L)) raise the free energy of P(+)BChl(L)(-) by comparable amounts. The results also suggest that the free energy of P(+)BChl(M)(-) is lowered more substantially by a Tyr at L181 than a Lys at L178. The results on the YFH mutant further demonstrate that the free energy differences between the L- and M-side charge-separated states play a significant role in the directionality of charge separation in the wild-type RC, and place limits on the contributing role of differential electronic matrix elements on the two sides of the RC.

Oxytocin mediates the inhibitory action of acute lithium on the morphine dependence in rats

The role of central oxytocin in inhibitory action of lithium on the development of morphine dependence was behavioral investigated in rats. Acute lithium could enhance the morphine-induced analgesia in rats with or without chronic morphine treatment; this effect could be inhibited by intraventricular injection of oxytocin antagonist d (CH(2))(5)-Tyr (Me)-[Orn(8)]-Vasotocin (OVT). Lithium could attenuate naloxone-precipitated withdrawal signs in morphine dependent rats. The reduction of the expression of naloxone-precipitated withdrawal signs by lithium was reversed by ICV of OVT. The lithium significantly inhibited the conditioned place preference (CPP) induced by morphine, which inhibitory action of lithium could also reverse by ICV injection of OVT. These results suggested that lithium might inhibit the physical dependence on morphine as well as psychological dependence in rats, and that this inhibitory effect of lithium on the development of morphine dependence might be associated with oxytocin systems in the central nervous system.

Effect of shear stress on efferent lymph-derived lymphocytes in contact with activated endothelial monolayers

L.ymphocyte interactions with endothelial cells in microcirculation are an important regulatory step in the delivery of lymphocytes to peripheral sites of inflammation. In normal circumstances, the predicted wall shear stress in small venules range from 10 to 100 dyn/cm2. Attempts to measure the adhesion of lymphocytes under physiologic conditions have produced variable results, suggesting the importance of studying biologically relevant migratory lymphocytes. To quantify the effect of shear stress on these migratory lymphocytes, we used lymphocytes obtained from sheep efferent lymph ducts, defined as migratory cells, to perfuse sheep endothelial monolayers under conditions of flow. Quantitative cytomorphometry was used to distinguish cells in contact with the endothelial monolayers from cells in the flow stream. As expected, migratory cells in contact with the normal endothelial monolayer demonstrated flow velocities less than the velocity of cells in the adjacent flow stream. The flow velocities of these efferent lymphocytes were independent of cell size. To model the inflammatory microcirculation, lymphocytes were perfused over sequential endothelial monolayers to directly compare the velocity of cells in contact with cytokine-activated and unactivated control monolayers. The tumor necrosis factor and interleukin-1-activated endothelial monolayers marginally decreased cell velocities at 1.2 dyn/cm2 (3.6%), but significantly reduced cell velocities 0.3 dyn/cm2 (27.4%; P < 0.05). Similarly, the fraction of statically adherent lymphocytes decreased as shear stress increased to 1.2 dyn/cm2. These results suggest that typical wall shear stress in small venules. of the order of 20 dyn/cm2, are too high to permit adhesion and transmigration of migratory lymphocytes. Additional mechanisnis must be present in vivo to facilitate lymphocyte transmigration in the inflammatory microcircu-

Focal topographic changes in inflammatory microcirculation associated with lymphocyte slowing and transmigration

Microcirculation is the primary mechanism for delivering lymphocytes to inflammatory tissues. Blood flow within microvessels ensures a supply of lymphocytes at the blood-endothelial interface. Whether the structure of the inflammatory microcirculation facilitates lymphocyte transmigration is less clear. To illuminate the microcirculatory changes associated with lymphocyte transmigration, we used intravital videomicroscopy to examine the dermal microcirculation after application of the epicutaneous antigen oxazolone. Intravascular injection of fluorescein-labeled dextran demonstrated focal topographic changes in the microcirculation. These focal changes had the appearance of loops or hairpin turns in the oxazolone-stimulated skin. Changes were maximal at 96 h and coincided with peak lymphocyte recruitment. To determine whether these changes were associated with lymphocyte transmigration, lymphocytes obtained from efferent lymph of draining lymph nodes at 96 h were fluorescently labeled and reinjected into inflammatory microcirculation. Epifuorescence intravital video microscopy demonstrated focal areas were associated with lymphocyte slowing and occasional transmigration. In contrast, focal loops and lymphocyte slowing were rarely observed in the contralateral control microcirculation. Results suggest that structural adaptations in inflammatory microcirculation represented by focal topographic changes may contribute to regulation of tissue entry by recirculating lymphocytes.

Biphasic response of the regional lymphatics in the normal lymphocyte transfer reaction

BACKGROUND

Initially developed for histocompatibility testing, the normal lymphocyte transfer (NLT) reaction involves the intradermal injection of allogeneic lymphocytes from one individual to another. Because of the unique kinetics of the immunological response to allogeneic lymphocytes, the NLT reaction has been considered an informative system for the analysis of transplant immunity.

METHODS

In this study, we used bilateral efferent lymph duct cannulations in sheep to examine the regional lymphatic response to the NLT reaction. Our studies used monoclonal antibodies to define lymphocyte population dynamics and DNA flow cytometry to reflect lymphocyte proliferative responses.

RESULTS

The results confirmed a biphasic NLT reaction. An unexpected finding was the marked differences between the early and late NLT responses. The early response was characterized by T-lymphocyte proliferation, as reflected by S-phase DNA, which was comparable in both the NLT-stimulated and contralateral control efferent lymphocytes. This bilateral proliferative response was observed in both CD4+ and CD8+ lymphocytes. In contrast, the late response was restricted to the efferent lymph from the NLT-stimulated lymph node. Dual-parameter flow cytometry demonstrated that the dominant component of this unilateral NLT response was CD8+ lymphocytes.

CONCLUSIONS

These results suggest important functional distinctions between systemic and regional lymphatic responses to intradermal alloantigens.

[A retrospective analysis of therapeutic outcome of various types of severe virus hepatitis]

OBJECTIVE

To explore combined therapeutic schemes for severe virus hepatitis and to raise survival rate.

METHODS

The therapeutic outcomes of different schemes were analyzed in 1020 cases of severe viral hepatitis treated in our hospital in recent twenty years. The treatments were classified as basic and combination of Chinese traditional and Western medicine therapies in which embryonic liver cell suspend liquid or hepatic growth factor, or/and artificial liver as blood cleaner were also used for the latter.

RESULTS

The survival rate was 30.28% (33/109) treated by basic procedures and 60.15% (548/911) by combined procedures. There was obvious statistical difference in survival rate between the two groups (P<0.001). Among all the patients, 219 (21.47%) suffered from acute or sub-acute severe hepatitis, 801 (78.53%) chronic severe hepatitis; 446 started their treatment at the early stage of the disease and the survival rate was 77.13% (344/446); 404 at the mid stage and 170 at the late stage and the survival rates were 52.72% (213/404) and 14.12% (24/170), respectively. The survival rate for the patients treated at the early or the mid stage was much higher than that at the late stage (P<0.001), and had a positive correlation with the activity of prothrombin.

CONCLUSION

The combined therapies used in present study are effective to raise the survival rate of the patients with severe virus hepatitis. Early treatment is extremely important for the patients' prognosis.

Glial cell line-derived neurotrophic factor enhances axonal regeneration following sciatic nerve transection in adult rats

Adult rat sciatic nerve was transected and sutured with an entubulation technique. The nerve interstump gap was filled with either collagen gel (COL) or collagen gel mixed with glial cell line-derived neurotrophic factor (COL/GDNF). Four weeks after nerve transection, horseradish peroxidase (HRP)-labelled spinal cord motoneurons and the myelinated distal stump axons were quantified. Compared with the COL group, the percentages of labeled spinal somas and axon number were significantly increased after topically applied glial cell line-derived neurotrophic factor (GDNF). The functional recovery of the transected nerve was improved in COL/GDNF group. GAP-43 expression was also significantly higher in COL/GDNF group 1 and 2 weeks after sciatic nerve axotomy vs. COL group. These data provide strong evidence that GDNF could promote axonal regeneration in adult rats, suggesting the potential use of GDNF in therapeutic approaches to peripheral nerve injury and neuropathies.

[Activation of p38 and c-Jun NH2-terminal kinase mitogen-activated protein kinases in human prostate carcinoma cell lines with different metastatic potentials]

OBJECTIVE

To investigate the influence of P2 purinoceptor agonist ATP on p38 mitogen-activated protein kinases (MAPK) and JNK (c-Jun NH(2)-terminal kinase) signaling pathway in two human prostate cancer cell sublines (1E8 and 2B4) with different metastasis potentials.

METHODS

Activated p38 and JNK were detected by Western blot with phospho-specific antibodies directed against the dually phosphorylated active forms of p38 or JNK.

RESULTS

Exposure of 1E8 and 2B4 prostate cancer cells to ATP resulted in p38 activation in a concentration- and time-dependent manner. ATP-induced p38 activities were higher in metastatic 1E8 cells when compared with nonmetastatic 2B4 cells. JNK signaling pathway was not activated by ATP. An MEK inhibitor PD 98059 failed to inhibit ATP-induced p38 activation, while p38 inhibitor SB 203580 and P2 purinoceptor antagonist suramin effectively inhibited activation of p38, the inhibition rate being 1E8 83% and 79%, 2B4 81% and 69%. The response of ATP-stimulated p38 to G-protein modulator pertussis toxin in 1E8 and 2B4 cells was not obvious.

CONCLUSIONS

p38 but not JNK signaling pathway can be activated by P2 purinoceptor agonist ATP. Differences of p38 activation by ATP are noted between metastatic 1E8 cells and non-metastatic 2B4 cells. These results provide instructive clues to cancer malignant growth and metastasis research.

Cytolytic peptides induce biphasic permeability changes in mammalian cell membranes

The cytolytic peptides melittin and gramicidin S are naturally occurring agents that provide a comparative model for studies of complement, immunotoxin and cell-mediated membrane permeability. Most attempts to characterize cytolytic peptides have used model membrane systems including phospholipid vesicles or erythrocytes. Membrane vesicles permit the use of self-quenching concentrations of fluorescent permeability markers, while erythrocytes release measurable hemoglobin. Attempts at measuring early membrane permeability changes in nucleated mammalian cells have been limited. To measure the kinetics of mammalian cell membrane permeability changes induced by cytolytic peptides, we developed a 96-well fluorescence cytolysis assay using the cytoplasmic fluorescent dye calcein as the membrane permeability marker. To facilitate rapid assessment of membrane permeability, trypan blue was added to the assay solution to quench (a) released fluorescence and (b) retained intracellular fluorescence. Trypan blue also provided a complementary visual assessment of cell viability. Using this assay, a detailed kinetic analysis demonstrated permeability of the cell membranes within seconds of exposure to the cytolytic peptides. The rapid permeabilization of the cell membranes was confirmed by flow cytometry using the calcium indicator dye fluo-3. The assay also demonstrated a second slower phase of marker release over the next several hours. The fluorescence cytolysis assay was able to reliably detect the biphasic permeability changes associated with the melittin and gramicidin S peptides suggesting the potential utility of this assay in the assessment of other cytolytic agents.

Cell adhesion molecule expression in the sheep thymus

Cell adhesion molecules are potential regulating factors in both prethymic and intrathymic T cell development. An experimental challenge has been the development of a large animal model that facilitates in vivo studies of both intrathymic development and lymphocyte migration. To extend earlier studies of thymic development, we have developed a panel of monoclonal antibodies (mAb) to a variety of sheep cell adhesion molecules. Immunohistochemistry was used to define mAb reactivity and flow cytometry was used to quantify expression of cell adhesion molecules within the thymus. To facilitate flow cytometry definition of cortical thymocytes, mAbs were developed to the sheep CD1 antigen. Dual parameter flow cytometry provided a phenotypic characterization of cell adhesion molecule expression on both CD1(+) and CD1(-) sheep thymocyte populations. These studies demonstrated significantly enhanced cortical thymocyte expression of three cell adhesion molecules: beta1 integrin (CD29), ICAM-2 and LFA-3. The beta1 integrin cell adhesion molecule was also expressed at higher levels on CD1(+) thymocytes in post-natal lambs as compared to adult sheep. These studies of thymocyte membrane molecule expression should facilitate future investigations of sheep intrathymic development and T lymphocyte immigration.

Glial cell line-derived neurotrophic factor promotes survival and induces differentiation through the phosphatidylinositol 3-kinase and mitogen-activated protein kinase pathway respectively in PC12 cells

PC12-GFRalpha1 cells, a clonal cell line engineered to express glial cell line-derived neurotrophic factor receptor alpha1 were constructed. Given glial cell line-derived neurotrophic factor could induce the differentiation and promote the survival of PC12-GFRalpha1 cells at low concentrations, the cells provide an unlimited source of monoclonal cells for studies on the signal transduction pathway of glial cell line-derived neurotrophic factor. To characterize the involvement of the mitogen-activated protein kinase and phosphatidylinositol 3-kinase pathways in the biological effect of glial cell line-derived neurotrophic factor, we used the mitogen-activated protein kinase kinase inhibitor PD98059 and the phosphatidylinositol 3-kinase inhibitor LY294002. PD98059 blocked glial cell line-derived neurotrophic factor-induced PC12-GFRalpha1 cells neurite formation in a dose-dependent manner, without significantly altering cell viability. LY294002 reversed the survival-promoting effect of glial cell line-derived neurotrophic factor on the PC12-GFRalpha1 cells in serum-deprived medium. The present study demonstrates that phosphatidylinositol 3-kinase pathway seems to mediate the survival-promoting effect of glial cell line-derived neurotrophic factor on PC12-GFRalpha1 cells, while the activation of mitogen-activated protein kinase pathway could be an important step in mediating PC12-GFRalpha1 cells differentiation induced by glial cell line-derived neurotrophic factor. Therefore, it is inferred that similar intracellular signaling components are used by distinct growth factors toward a common biological effect.

[Trophic effect of ciliary neurotrophic factor on denervated skeletal muscle]

AIM

The trophic effect of CNTF on skeletal muscle atrophy and dysfunction reduced by denervation was investigated in SD rats.

METHODS

SD rats transected sciatic nerve in right side hind limbs were injected CNTF subcutaneously for 20 days. Skeletal muscle wet weights, protein contents, muscle fiber cross-sectional areas, contract properties and degree of hind limb abnormalities were observed in the rats.

RESULTS

(1) Administrating of CNTF (0.2 mg/kg) in sciatic nerve transected SD rats attenuated denervation-induced skeletal muscle fiber atrophy evidently, resulted in gastrocnemius in injury side an obvious increase in contract function, prevented the loss of weights and protein in denervated skeletal muscle, and ameliorated abnormalities in sciatic nerve cut limbs remarkably. (2) The myotrophic effect of 0.2 mg/kg CNTF is more effective than 0.05 mg/kg. (3) The sensitivity to CNTF varied in muscles of different type; slow twitch muscle (soleus muscle) reacted to CNTF stronger and quicker than twitch muscle (extensor digitorum longus).

CONCLUSION

CNTF significantly attenuates denervation-reduced skeletal muscle atrophy and dysfunction in SD rats, act an evident myotrophic effect on denervated skeletal muscle. And this effect may be exerted in a dosage dependent manner and varies with muscle type.

Effects of histone acetylation on the solubility and folding of the chromatin fiber

The folding ability of chromatin fractions containing approximately identical nucleosome numbers and the same linker histone composition, but with different extents of core histone acetylation, were analyzed by analytical ultracentrifugation. It was found that the acetylated fractions consistently exhibited a relatively small but significantly lower extent of compaction than that of their native nonacetylated counterparts. This was regardless of the extent of the size distribution heterogeneity of the fractions analyzed. Furthermore the acetylated chromatin fibers exhibited an enhanced solubility in both NaCl and MgCl(2), which is neither the result of a differential binding affinity of the linker histones to chromatin nor of an alteration in the relative amounts of the histone H1 variants.

The expression of G-protein-gated inwardly rectifying K+ channels GIRK1 and GIRK2 mRNAs in the supraoptic nucleus of the rat and possible role involved

The expression of G-protein-gated inwardly rectifying K channels subunits GIRK1 and GIRK2 mRNAs in the supraoptic nucleus (SON) was investigated in the rat by in situ hybridization with non-radioactive dig-labeled cRNA probes. Double-labeled methods were used to study the co-localization of GIRK1 and 2 and oxytocin (OT) and vasopressin (AVP) in the SON. The present study revealed wide and intense expression of GIRK1 and GIRK2 mRNAs with high overlapping in the SON, indicating the heterologous channel of GIRK1/GIRK2 was a major functional channel in the SON. Given that 100% of OT-positive and 95% of (AVP)-positive neurons in the SON expressed GIRK1/GIRK2 mRNAs, it is possible that GIRK1/GIRK2 channel, activated through G-protein coupled receptors, may be involved in the inhibitory regulation of the release of OT and AVP from the SON.

A novel chordin-like protein inhibitor for bone morphogenetic proteins expressed preferentially in mesenchymal cell lineages

Chordin is a bone morphogenetic protein (BMP) inhibitor that has been identified as a factor dorsalizing the Xenopus embryo. A novel secreted protein, CHL (for chordin-like), with significant homology to chordin, was isolated from mouse bone marrow stromal cells. Injection of CHL RNA into Xenopus embryos induced a secondary axis. Recombinant CHL protein inhibited the BMP4-dependent differentiation of embryonic stem cells in vitro and interacted directly with BMPs, similar to chordin. However, CHL also weakly bound to TGFbetas. In situ hybridization revealed that the mouse CHL gene, located on the X chromosome, was expressed predominantly in mesenchyme-derived cell types: (1) the dermatome and limb bud mesenchyme and, later, the subdermal mesenchyme and the chondrocytes of the developing skeleton during embryogenesis and (2) a layer of fibroblasts/connective tissue cells in the gastrointestinal tract, the thick straight segments of kidney tubules, and the marrow stromal cells in adults. An exception was expression in the neural cells of the olfactory bulb and cerebellum. Interestingly, the spatiotemporal expression patterns of CHL were distinct from those of chordin in many areas examined. Thus, CHL may serve as an important BMP regulator for differentiating mesenchymal cells, especially during skeletogenesis, and for developing specific neurons.

Antitumor activity and bystander effects of the tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) gene

Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) has been reported to specifically kill malignant cells but to be relatively nontoxic to normal cells. To evaluate the antitumor activity and therapeutic value of the TRAIL gene, we constructed adenoviral vectors expressing the human TRAIL gene and transferred them into malignant cells in vitro and tumors in vivo. The in vitro transfer elicited apoptosis, as demonstrated by the quantification of viable or apoptotic cells and by the analysis of activation of pro-caspase-8 and cleavage of poly(ADP-ribose) polymerase. The intratumoral delivery elicited tumor cell apoptosis and suppressed tumor growth. In comparison with Bax gene treatment, which is toxic to normal cells, TRAIL gene treatment caused no detectable toxicity in cultured normal fibroblasts nor in mouse hepatocytes after systemic gene delivery. Furthermore, coculture of cancer cells expressing TRAIL with those expressing green fluorescent protein (GFP) resulted in apoptosis of both cells, whereas coculture of Bax-expressing cells with GFP-expressing cells resulted in the cell death of the Bax-expressing cells only, which suggested that the transfer of the TRAIL gene resulted in bystander effects. Moreover, culture of cells with medium from TRAIL-expressing cells showed the proapoptotic activity and bystander effect of the TRAIL gene to be not transferable with medium. To further demonstrate the bystander effect of the TRAIL gene, we constructed plasmid vectors encoding GFP-TRAIL or GFP-Bik chimeric proteins. Transfection of the GFP-TRAIL gene into cancer cells resulted in the death of GFP-positive cells and their neighbors, whereas transfection of the GFP-Bik gene killed GFP-positive cells only. Finally, GFP-TRAIL genes, transfected into normal human fibroblasts or bronchial epithelial cells, did not kill such cells, whereas transfected GFP-Bik genes did. Thus, the direct transfer of the TRAIL gene led to selective killing of malignant cells with bystander effect, which suggests that the TRAIL gene could be valuable for treatment for cancers. Together, these results suggest that delivering the TRAIL gene to cancerous cells may be an alternative approach to cancer treatment.

Analysis of expressions of components in the plasminogen activator system in high- and low-metastatic human lung cancer cells

PURPOSE

To determine the expressive patterns of the components of the plasminogen activator system in human large-cell lung carcinoma strains and to analyze the effects of the patterns on tumor invasion and metastasis.

METHODS

The in vitro and in vivo invasive and metastatic potential of two human large-cell lung carcinoma strains with high (strain 95D) and low (strain 95C) metastatic potential was further confirmed by the Boyden chamber model and nude mice model. After this, the expressions of the components of the plasminogen activator system--including urokinase-type and tissue-type plasminogen activator (uPA and tPA), urokinase receptor (uPAR), and type-1 and type-2 plasminogen activator inhibitor (PAI-1 and PAI-2) in strain 95D and 95C cells--were determined by RT-PCR and immunohistochemical staining. The effects of monoclonal antibodies of uPA, uPAR, and PAI-1 on the invasive potential of strain 95D cell line were also evaluated.

RESULTS

Strain 95D cells were found to have a stronger in vitro and in vivo invasive and metastatic potential than strain 95C cells. In the former, the average number of infiltrating cells in the in vitro model in one field of vision (40055) was 73.75 +/- 7.42, while in the latter, it was 56.33 +/- 6.28 (P < 0.001). Lung metastatic loci were observed in all six nude mice inoculated with 95D cells (6/6), but not in any of the nude mice inoculated with 95C cells (0/6). The high-metastatic strain 95D cells expressed higher uPA and uPAR and lower tPA and PAI-2 than the low-metastatic strain 95C cells. The PAI-1 expressions in both 95D and 95C cells were almost the same. Monoclonal antibodies of uPA and uPAR greatly reduced the invasive potential of strain 95D cells in vitro.

CONCLUSIONS

These data suggest that the invasive and metastatic potential of human large-cell lung carcinoma cell lines is associated with differential expressions of the components of the plasminogen activator system and that the determination of these components may be used as a marker for judging clinically the possibility of tumor metastasis as well as the prognoses of patients.

Aldehyde fixation of thiol-reactive fluorescent cytoplasmic probes for tracking cell migration

Tracking of cell migration plays an important role in the study of morphogenesis, inflammation, and metastasis. The recent development of probes that exist as intracellular peptide-fluorescence dye adducts has offered the possibility of aldehyde fixation of these dyes for detailed anatomic studies of lymphocyte trafficking. To define the conditions for fixation of these cytoplasmic fluorescent probes, we compared fixation conditions containing formaldehyde, glutaraldehyde, paraformaldehyde, zinc formaldehyde, and glyoxylate, as well as fixation by quick-freezing in liquid nitrogen-cooled methylbutane. The efficacy of aldehyde fixation of the cell fluorescence was assessed by quantitative tissue cytometry and flow cytometry. We studied cytoplasmic fluorescent dyes with discrete emissions in the green [5-chloromethylfluorescein diacetate (CMFDA); 492 ex, 516 em] and orange [5-(and-6)-(4-chloromethyl(benzoyl)amino) tetramethylrhodamine (CMTMR); 540 ex, 566 em] spectra. The results demonstrated that aldehyde fixation preserved cell fluorescence for more than 6 months. The primary difference between the aldehyde fixatives was variability in the difference between the yield of the cell fluorescence and the relevant background fluorescence. Formaldehyde and paraformaldehyde were superior to the other fixatives in preserving cell fluorescence while limiting background fluorescence. With these fixatives, both the CMFDA and CMTMR fluorescent dyes permitted sufficient anatomic resolution for reliable localization in long-term cell tracking studies.

[Optical parameters of Tm3+ in oxyfluoride glass ceramic]

Optical-absorption spectrum of Tm3+ ions in oxyfluoride glass ceramic was measured, from which the measured oscillator strengths were obtained. The Judd-Ofelt intensity parameters omega t (t = 2, 4, 6) were determined by a best fit of the calculated and measured oscillator strengths, the rms deviation was 3.9 x 10(-7). Some predicted spectroscopic parameters of the excited states, like the spontaneous radiative transition rate, radiative lifetime, branching ratio and integrated emission cross section were given using the intensity parameters. The spectroscopic parameters were comparable with some laser materials, and some of them were better.

Synthesis and electrochemical studies of diiron complexes of 1,8-naphthyridine-based dinucleating ligands to model features of the active sites of non-heme diiron enzymes

A bis(mu-carboxylato)(mu-1,8-naphthyridine)diiron(II) complex, [Fe2(BPMAN)(mu-O2CPhCy)2](OTf)2 (1), was prepared by using the 1,8-naphthyridine-based dinucleating ligand BPMAN, where BPMAN = 2,7-bis[bis(2-pyridylmethyl)aminomethyl]-1,8-naphthyridine. The cyclic voltammogram (CV) of this complex in CH2Cl2 exhibited two reversible one-electron redox waves at +296 mV (DeltaE(p) = 80 mV) and +781 mV (DeltaE(p) = 74 mV) vs Cp2Fe+/Cp2Fe, corresponding to the FeIIIFeII/FeIIFeII and FeIIIFeIII/FeIIIFeII couples, respectively. This result is unprecedented for diiron complexes having no single atom bridge. Dinuclear complexes [Fe2(BPMAN)(mu-OH)(mu-O2CPhCy)](OTf)2 (2) and [Mn2(BPMAN)(mu-O2CPhCy)2](OTf)2 (3) were also synthesized and structurally characterized. The cyclic voltammogram of 2 in CH2Cl2 exhibited one reversible redox wave at -22 mV only when the potential was kept below +400 mV. The CV of 3 showed irreversible oxidation at potentials above +900 mV. Diiron(II) complexes [Fe2(BEAN)(mu-O2CPhCy)3](OTf) (4) and [Fe2(BBBAN)(mu-OAc)2(OTf)](OTf) (6) were also prepared and characterized, where BEAN = 2,7-bis(N,N-diethylaminomethyl)-1,8-naphthyridine and BBBAN = 2,7-bis[2-[2-(1-methyl)benzimidazolylethyl]-N-benzylaminomethyl]-1,8-naphthyridine. The cyclic voltammograms of these complexes were recorded. The Mössbauer properties of the diiron compounds were studied.

[Mechanism of the activation of extracellular signal-regulated kinase (ERK) in prostate cancer cell lines with different metastatic potential]

OBJECTIVE

To investigate the mechanism of the activation of signal transduction of ERK induced by purinergic receptor agonist ATP in prostate cancer cells with different metastatic potential.

METHODS

Cell counts and MTT method were used to detect the influence of ATP on the growth of 1E8 (metastatic) and 2B4 (non-metastatic) cells derived from human prostate cancer cell line PC3M. The activity of ERK1/2 was analyzed with phosphospecific antibodies directed against the dually phosphorylated, active forms of ERK1/2 (p44/p42) by Western Blot.

RESULTS

ATP can significantly inhibit the growth of 1E8 and 2B4 cells in vitro (inhibition rate in the 6th and the 8th day were 54% and 59% for 1E8 and 67% and 39% for 2B4 respectively). ATP activated both ERK1 and ERK2 in 1E8 and 2B4 cells with a time and dose dependent pattern. The activation of ERK1/2 by ATP was blocked by the P2 purinoceptor antagonist, suramin with an inhibitory rate of 82% +/- 9% for 1E8 and an inhibitory rate of 81% +/- 6% for 2B4. The activation of ERK1/2 by ATP can be inhibited by the inhibitor of the upstream kinase MEK- PD098059 with an inhibitory rate of 94% +/- 4% for 1E8 and 91% +/- 4% for 2B4,which suggests a link between the G protein coupled P2 purinoceptor and activation of Ras MEK MAPK pathway. ATP-stimulated ERK activation was sensitive to treatment with G protein modulator pertussis toxin (PTX) with an inhibitory rate of 50% +/- 3% for 1E8 and 51% +/- 4% for 2B4. The activating potential of ATP to ERK1/2 in metastatic 1E8 cells is greater than that to nonmetastatic 2B4 cells, and the response of 1E8 cells to TPA was quite different from the response of 2B4 cells, thus implying a potential signaling mechanism in regulating metastasis phenotypes.

CONCLUSION

The metastatic 1E8 and non-metastatic 2B4 cells show differential response to ATP-induced ERK activation. This may provide an instructive clue to cancer metastasis research.

Stochastic regulation of cell migration from the efferent lymph to oxazolone-stimulated skin

The systemic immune response is a dynamic process involving the trafficking of lymphocytes from the Ag-stimulated lymph node to the peripheral tissue. Studies in sheep have demonstrated several phases of cell output in the efferent lymph after Ag stimulation. When skin contact sensitizers are used as Ag, the efferent lymph cell output peaks approximately 96 h after Ag stimulation and is temporally associated with the recruitment of cells into the skin. To investigate the relative contribution of this high-output phase of efferent lymphocytes to lymphocytic inflammation in the skin, we used a common contact sensitizer 2-phenyl-4-ethoxymethylene-5-oxazolone (oxazolone) to stimulate the skin and draining prescapular lymph node of adult sheep. The efferent lymph ducts draining the Ag-stimulated and contralateral control lymph nodes were cannulated throughout the experimental period. The lymphocytes leaving the lymph nodes during the 72-h period before maximum infiltration were differentially labeled with fluorescent tracers, reinjected into the arterial circulation, and tracked to the site of Ag stimulation. Quantitative tissue cytometry of the skin at the conclusion of the injection period (96 h after Ag stimulation) demonstrated more migratory cells derived from the Ag-stimulated lymph node than the contralateral control (median 18.5 vs 15.5 per field; p < 0.05). However, when corrected for total cell output of the lymph node, the Ag-stimulated migratory cells were 3.8-fold more prevalent in the skin than the contralateral control cells. These results suggest that the in situ immune response generally mirrors the frequency of recruitable lymphocytes in the peripheral blood.

Dipeptide seryl-histidine and related oligopeptides cleave DNA, protein, and a carboxyl ester

The amino acids histidine (His) and serine (Ser), or amino acids similar to Ser, function together as key catalytic amino acids in the active sites of such diverse enzymes as the serine- and thiol-proteases, lipases, and esterases. Ser and His are also conserved in the intein-extein junctions of the phylogenetically widespread self-splicing proteins and at the N- and C-termini of the homing endonucleases spliced from them. Here we show that the dipeptide seryl-histidine (Ser-His) and related oligopeptides can themselves cleave DNA, protein, and the ester p-nitrophenyl acetate (p-NPA) over wide ranges of pH and temperature. Denaturing polyacrylamide gel electrophoresis (PAGE) of 5'-end labeled DNA samples incubated with Ser-His reveals a pattern of two bands per nucleotide position, consistent with the generation of both 3'-hydroxyl and 3'-phosphate DNA cleavage fragments, as would be expected of phosphodiester hydrolysis by Ser-His. To the best of our knowledge, Ser-His is the shortest peptide ever reported to show cleavage activity with multiple categories of natural substrates. The amenability of the dipeptide to variation through addition of amino acid residues, either internally or to the C-terminus while retaining its multiple cleavage activities, combined with its reactivity over wide ranges of pH and temperature, demonstrates the evolutionary capacity of the Ser/His dyad and evokes many questions about possible roles it may have played in molecular evolution and its potential role as a core for selection of oligopeptides with enhanced cleavage activities and target specificity.

Synthesis and characterization of several dicopper(I) complexes and a spin-delocalized dicopper(I,II) mixed-valence complex using a 1,8-naphthyridine-based dinucleating ligand

The synthesis of dicopper(I) complexes [Cu2(BBAN)(MeCN)2](OTf)2 (1), [Cu2(BBAN)(py)2](OTf)2 (2), [Cu2(BBAN)(1-Me-BzIm)2](OTf)2 (3), [Cu2(BBAN)(1-Me-Im)2](OTf)2 (4), and [Cu2(BBAN)(mu-O2CCPh3)](OTf) (5), where BBAN = 2,7-bis((dibenzylamino)methyl)-1,8-naphthyridine, py = pyridine, 1-Me-Im = 1-methylimidazole, and 1-Me-BzIm = 1-methylbenzimidazole, are described. Short copper-copper distances ranging from 2.6151(6) to 2.7325(5) A were observed in the solid-state structures of these complexes depending on the terminal ligands used. The cyclic voltammogram of compound 5 dissolved in THF exhibited a reversible redox wave at E1/2 = -25 mV vs Cp2Fe+/Cp2Fe. When complex 5 was treated with 1 equiv of silver(I) triflate, a mixed-valence dicopper(I,II) complex [Cu2(BBAN)(mu-O2CCPh3)(OTf)](OTf) (6) was prepared. A short copper-copper distance of 2.4493(14) A observed from the solid-state structure indicates the presence of a copper-copper interaction. Variable-temperature EPR studies showed that complex 6 has a fully delocalized electronic structure in frozen 2-methyltetrahydrofuran solution down to liquid helium temperature. The presence of anionic ligands seems to be an important factor to stabilize the mixed-valence dicopper(I,II) state. Compounds 1-4 with neutral nitrogen-donor terminal ligands cannot be oxidized to the mixed-valence analogues either chemically or electrochemically.

The effect of CNTF on glutamate-induced increases in intracellular free Ca2+ in hippocampal neurons

Ciliary neurotrophic factor (CNTF) acts through the JAK/STAT signal transduction pathway. However, the rapid action of CNTF cannot readily be explained by reference to this pathway. Using the fluorophore, Fura 2-AM, and fluorescence imaging, the effect of CNTF on glutamate-induced increases in hippocampal intraneuronal free Ca2+ ([Ca2+]i) was investigated. Glutamate induces a rapid increase in [Ca2+]i. Incubation of hippocampal neurons with CNTF for 5 min inhibited the glutamate-induced increase in [Ca2+]i. In the absence of glutamate, CNTF had no effect on [Ca2+]i. Pertussis toxin (PTX), a G-protein antagonist, partially blocked the effect of CNTF. This suggests that CNTF may act via an alternative signal transduction pathway besides the generic JAK/STAT pathway.

Terephthalaldehyde bis(thiosemicarbazone) bis(dimethylformamide) solvate

The thiosemicarbazone molecule in C(10)H(12)N(6)S(2).2C(3)H(7)NO has -1 symmetry. The thiosemicarbazone moiety and the benzene ring are essentially coplanar, with mean and maximum deviations of 0.03 and 0. 11 A, respectively. The dimethylformamide molecules bridge the thiosemicarbazone moieties, forming two-dimensional sheets through N-H.O hydrogen bonds.

[Clinical application of extended resection of Vater's papilla]

OBJECTIVE

To report the surgical technique and clinical application of extended resection of Vater's papilla (ERVP).

METHODS

ERVP was performed in 12 selected patients with tumors of ampulla of Vater according to the following criteria: (1) no signs of distant mestastasis before operation; (2) no hepatic and peritoneal mestastasis during exploration, frozen section of peripancreas-duodenal lymph nodes being negative; (3) tumor less than 2 cm in diameter, pathologic examination of tumor being adenocarcinoma or adenoma; (4) pathologic examination of edge of resection being negative.

RESULTS

There was no operative death nor complications in 12 cases treated by ERVP. The average time of operation was 2.3 hours, the average amount of blood infused was 433 ml, and the average time of hospitalization was 15.8 days. In 5 of 10 cases of Vater's ampullary adenocarcinoma, the mean survival time was 42 months (36-62 months). The remaining 5 cases are still alive at 20-64 months. Two patients with Vater's ampullary adenoma still survive at 32 and 46 months, respectively.

CONCLUSION

ERVP is easy to perform with comparatively less surgical trauma and complication, but redical excision of tumor is not easy. It may be particulary indicated for older and high-risk patients, or patients with cancer less than 2 cm in diameter.