Cloning and RNAi-mediated functional characterization of MaLac2 of the pine sawyer, Monochamus alternatus

Laccase, a member of a group of proteins collectively known as multicopper oxidases, is hypothesized to play an important role in insect cuticle sclerotization by oxidizing catechols in the cuticle to their corresponding quinones, which then catalyze protein cross-linking reactions. Laccase 2 has been proved as the gene required for beetle cuticle tanning through RNA interference (RNAi) experiments on red flour beetle Tribolium castaneum. The pine sawyer beetle, Monochamus alternatus (Coleoptero: Cerambycidae) is the insect serving as a major vector of the pinewood nematode, Bursaphelenchus xylophilus, which is the causative agent for pine wilt disease. The cDNA of MaLac2 was cloned from the insect in this study. The conceptual amino-acid sequence deduced was much conserved with other known insect laccases, particularly with the enzyme of Tribolium castaneum. Injection in hemolymph of pine sawyer larva of dsRNA targeting the laccase 2 mRNA leads to important alterations of the tanning, hardening and sclerotization of the pupal and adult cuticles. Defaults appear in a dose-dependent manner and high loads of dsRNA are lethal. The decrease of the endogenous laccase 2 mRNA affects the procuticle which is thinner and without the characteristic piling up of successive layers. The observations reinforce the role of laccase 2 as an essential phenoloxidase for making cuticle.

Minerals, phenolic compounds, and antioxidant capacity of citrus peel extract by hot water

Some dried citrus peels, more familiar as chenpi in China, have been widely used in traditional Chinese medicines from ancient times. This paper reports the efficiency of infusion cooking on extracting minerals and phenolic compounds (flavanone glycosides [FGs], polymethoxylated flavones [PMFs], and phenolic acids), and also antioxidant activity of hot water extract of citrus peels. Peels of 2 citrus varieties, namely, Satsuma mandarin (C. unshiu Marc.) and Ponkan (C. poonensis Hort. ex Tanaka), which belong to C. reticulata, were selected. As a result, hot water extraction was efficient in extracting phenolic acids and some minerals. As for citrus flavonoids, narirutin, nobiletin, and tangeretin were easier to extract than hesperidin. The result of antioxidant capacity assays indicated that for citrus peels, hot water extract had almost the same capacity as the methanol extract. We suggested that Ponkan was more suitable as the source of chenpi, since its hot water extract had much higher content of phenolic acids, FGs and PMFs, and higher antioxidant capacity than those of Satsuma mandarin. Generally, to raise the extraction temperature or to prolong the time could not yield higher content of phenolic compounds and stronger antioxidant capacity, though the content of minerals increased to some extent. Furthermore, a 2nd-time extraction seemed necessary since considerable minerals and phenolic compounds could be obtained by doing so. Finally, we suggested that 2 times extraction at 100 degrees C for 30 min was proper to extract the minerals and phenolic compounds in chenpi.

A new protein crystallization system with large number of cells

A protein crystallization system with large number of cells for vapor and liquid/liquid diffusion was developed for crystallization of protein and other macromolecules in space. It has high ratio of cell number over system dimension or mass. A facility with it can save the space resource and suitable for boarding of many kinds of spacecraft.

Protective role of 3-nitro-N-methyl-salicylamide on isolated rat heart during 4 hours of cold storage and reperfusion

OBJECTIVE

Cardiac ischemia/reperfusion (I/R) injury, a necessary consequence of transplantation, is probably related to the formation of reactive oxygen species (ROS). The ROS burst within the first moments of reperfusion is associated with injury, continuously generate O2- at about 3% to 5% of total O2 consumption owing to electron leak by mitochondrial oxidoreductases, especially complexes I and III. 3-nitro-N-methyl-salicylamide (NNMS) displays inhibitory effects on succinate-cytochrome C reductase, but also reduces effects on creation of O2- radical and H2O2 by isolated rat mitochondria. Presumably NNMS inhibits electron leakage from the mitochondrial respiratory chain. We investigated effect of NNMS on heart protection after hypothermic ischemia.

METHODS

A Langendorff-prepared rat heart model was employed after the heart had been preserved for 4 hours under hypothermic conditions of ischemia with subsequent reperfusion/rewarming for 60 minutes.

RESULTS

The group of hearts treated with NNMS showed increased recovery of heart function compared with a group of mEC. The lactate dehydrogenase (LDH) activity in coronary flow (CF) by hearts treated with NNMS was lower than that with mECs, as was the content of malonedialdehyde (MDA) and conjugated diene (CD).

CONCLUSIONS

NNMS improved heart physiology after reperfusion following 4 hours of hypothermic ischemia.

Role of cytosolic liver fatty acid binding protein in hepatocellular oxidative stress: effect of dexamethasone and clofibrate treatment

The presence of cysteine and methionine groups together with an ability to bind long-chain fatty acid (LCFA) oxidation products makes liver fatty acid binding protein (L-FABP) an attractive candidate against hepatocellular oxidative stress. In this report, we show that pharmacological treatment directed at modulating L-FABP level affected hepatocellular oxidant status. L-FABP expressing 1548-hepatoma cells, treated with dexamethasone or clofibrate, decreased and increased intracellular L-FABP levels, respectively. Oxidative stress was induced by H2O2 incubation or hypoxia-reoxygenation. The fluorescent marker, dichlorofluorescein (DCF), was employed to measure intracellular reactive oxygen species (ROS). Hepatocellular damage was assessed by lactate dehydrogenase (LDH) level. Dexamethasone treatment resulted in a significant increase in DCF fluorescence with higher LDH release compared to control cells. Clofibrate treatment, however, resulted in a significant decrease in both parameters (p<0.05). Drug treatments did not affect cytosolic activities of glutathione peroxidase (GPx), superoxide dismutase (SOD), or catalase suggesting that the differences between treated and control cells may likely be associated with varying L-FABP levels. We conclude that L-FABP may act as an effective endogenous cytoprotectant against hepatocellular oxidative stress.

Phase I study of interleukin 2 (IL2) maintenance after induction with weekly docetaxel and estramustine in patients with metastatic hormone refractory prostate cancer (HRPC)

14526

Background: Patients with HRPC commonly respond to docetaxel, but many develop asthenia and other docetaxel related toxicities that impair quality of life and hence, many clinicians prescribe a “chemotherapy vacation”. IL2 exerts its anti-tumor effect through activation of T cells and NK cells and at high dose has been shown to have efficacy (and toxicity) in men with HRPC (Maffezzini, The Prostate 1996). Low dose IL2 and 13-cis-retinoic acid given as maintenance after cytoreduction of advanced solid tumors was associated with increased numbers of circulating NK cells as well as further tumor responses (Recchia, Proc ASCO 2001). A phase I trial of low dose IL2 maintenance after chemo induction was undertaken. Methods: Chemotherapy naive pts with metastatic HRPC were induced with weekly docetaxel 35 mg/m2 on day 2 and estramustine 280 mg/M2 TID on days 1 and 2 for 3 wks followed by 1 wk off for a total of 12 doses of chemotherapy. Responding pts received maintenance IL2 for 5 days/wk for 3 wks, followed by 1 wk off. During the 3rd wk, a boost dose was administered on days 2 and 3. Level 1 maintenance was 0.5 x106 IU/m2 SC bid, level 2 was 0.75 × 106 IU/m2 SC bid. Level 1 boost was 3 × 106 IU/m2, level 2 was 4.5 × 106 IU/m2 SC bid. Cohorts of 3 patients were treated at a given dose level according to standard dose escalation schemes for toxicity. IL2 was continued until objective progression was documented. Results: 15 pts, median age of 70 (range 46–78), median PSA 32.7 (range 2.28 to 1248) were enrolled. After chemotherapy, 12 pts had > 50% (7 had > 75%) decline in PSA, 3 pts had < 50% decline. 13 pts went on to receive IL2. The MTD for maintenance IL2 was 0.5 × 106 IU/m2 SC bid (4 pts at level 1 had no toxicity but 3 of 4 at level 2 had grade 2 toxicity requiring a drop to level 1). MTD for the boost was 3 × 106 IU/m2 (4 with no toxicity at level 1, 3 of 3 with grade 2 toxicity at level 2 requiring a drop to level 1). The most common toxicities were fatigue, nausea, chills, edema. One pt has received IL2 maintenance for 25 months. Conclusions: IL2 maintenance can be safely administered at the MTD. Immunological studies before/after chemotherapy and during IL2 are pending.

No significant financial relationships to disclose.

Characteristics and outcomes of cancer patients ≥80 years treated with chemotherapy at a comprehensive cancer center

8548

Background: The percentage of cancer patients ≥ 80 years old is expected to rise in the United States. However data are limited on use of chemotherapy in this group of patients. Methods: Retrospective identification of patients who received systemic chemotherapy at our cancer center between 1/1/2000 to 12/31/2004 was performed using the computer generated pharmacy data and medical records. Patients who had diagnosis of cancer and ≥ 80 years were included in the study; patients receiving only supportive care, hormonal therapy, or oral chemotherapy were excluded. The protocol for this study was approved by the Wayne State University IRB. Results: A total of 133 patients ≥ 80 years who received chemotherapy was analyzed. The median age was 83 and 31% of the patients were ≥ 85 years. There were more females (61%) than males (39%). The gender distribution was more even (47% v. 53%) after excluding gender specific tumors. The racial distribution was diverse- Whites 65 (49%); Blacks 41 (31%); Other 18 (13%); Unknown 9 (7%). 16% of the patients had hematologic malignancy and 84% had solid tumors. Gynecological cancers (32%) followed by aerodigestive cancers (26%) were the most common solid tumors. Solid tumor patients primarily had regional (48%) or distant (45%) disease. During the first regimen, 512 cycles of chemotherapy was delivered with a median of 3 cycles per patient (range 1–24 cycles); 40% of patients received only 2 cycles of chemotherapy. 64% of patients were able to receive chemotherapy without 2nd cycle delay. The distribution of single or multidrug regimens was fairly similar; Solid tumors 52% v. 48%; Hematologic cancers 43% v. 57%. Carboplatin and paclitaxel (22%) was the most common regimen among solid tumor patients. 26% of all patients received a second regimen. The 1 year survival rates among hematologic cancer and solid tumor patients were 65% and 48%, respectively. Stage of disease was the only statistically significant factor predicting survival. Conclusions: In this diverse group of cancer patients ≥ 80 years old and selected for chemotherapy, the treatment was feasible. The survival outcomes in this elderly population were comparable to those of a younger patient population suggesting that the treatment is beneficial.

No significant financial relationships to disclose.

Interaction effects and pseudogap in two-dimensional lateral tunnel junctions

Tunneling characteristics of a two-dimensional lateral tunnel junction are reported. A pseudogap on the order of Coulomb energy is detected in the tunneling density of states (TDOS) when two identical two-dimensional electron systems are laterally separated by a thin energy barrier. The Coulombic pseudogap remains robust well into the quantum Hall regime until it is overshadowed by the cyclotron gap in the TDOS. The pseudogap is modified by the in-plane magnetic field, demonstrating a nontrivial effect of the in-plane magnetic field on the electron-electron interaction.

Mechanisms of modulation of pregnanolone on glycinergic response in cultured spinal dorsal horn neurons of rat

The glycine receptors and neurosteroids in spinal cord are both implicated in nociceptive signal processing. However, the modulatory effects of neurosteroid pregnanolone (5beta-pregnan-3alpha-ol-20-one) on native glycine receptors remain unclear. In the present study, we examined the effects of pregnanolone and its three isomers on glycine receptors by using whole-cell patch-clamp technique. Our results showed that pregnanolone reversibly inhibited the amplitude of glycine-induced current mediated by native glycine receptors and recombinant alpha1-, alpha2-, alpha3- and alpha1beta-glycine receptors. In cultured spinal dorsal horn neurons of rats, pregnanolone inhibited the glycine-induced current in dose-dependent manner, with an antagonist concentration inducing half-maximal response of 1.0+/-0.3 microM. The inhibitory effect of pregnanolone on glycine-induced current was voltage-independent and pregnanolone shifted the concentration-response curve for glycine-induced current rightward in a parallel manner without altering the maximal value and Hill coefficient. The isomer of pregnanolone, allopregnanolone (5alpha-pregnan-3alpha-ol-20-one) slightly enhanced glycine-induced current, whereas iso-pregnanolone (5beta-pregnan-3beta-ol-20-one) and iso-allopregnanolone (5alpha-pregnan-3beta-ol-20-one) did not affect the glycine-induced current significantly in cultured spinal dorsal horn neurons. Thus, our results suggest that the inhibitory effect of pregnanolone on glycine-induced current is of a competitive type and depends on the stereo structure of pregnanolone. Furthermore, pregnanolone decreased the amplitude and frequency of the glycinergic miniature inhibitory postsynaptic currents. Through modulating the glycinergic inhibitory neurotransmission, pregnanolone may affect the nociceptive sensory processing under physiological and pathological conditions.

Usage of an intronic promoter for stable gene expression in Saccharomyces cerevisiae

AIMS

To construct expression vectors capable of switching promoters under different metabolic circumstances to obtain stable gene expression.

METHODS AND RESULTS

In this study, we designed a series of constructs for the expression of the chicken lactate dehydrogenase (cldh) gene under the control of galactose-inducible GAL1 promoter and the high glucose-inducible HXT1 promoter in Saccharomyces cerevisiae. In one construct, the HXT1 promoter was placed between artificial splicing sequences to function as an intronic promoter. We checked all constructs for the usage of promoters by reverse transcriptional polymerase chain reaction and assayed the expression level of the reporter gene under different culturing conditions. In the presence of galactose, when the GAL1 promoter was linked with the intronic HXT1 promoter, the cldh gene showed 1.5-fold activity compared with single GAL1 promoter, while in the presence of glucose, the construct showed over twofold activity compared with that without splicing sequences.

CONCLUSION

The intronic HXT1 promoter could be induced by the presence of high glucose concentration.

SIGNIFICANCE AND IMPACT OF THE STUDY

This is the first report detailing the use of an intronic promoter in the construction of stable expression vectors and the novel system could serve as a model of expression vectors for fermentation or other purposes.

Monitoring of skeletal progression of prostate cancer by GFP imaging, X-ray, and serum OPG and PTHrP

BACKGROUND

Prostate cancers (PCas) produce factors that can serve as biomarkers for tumor metastasis and bone progression. Transduced GFP expression by cancer cells can be imaged to monitor therapy. We exploited both concepts by developing a GFP-expressing PCa cell line that expresses PTHrP and studying it in an animal model of malignancy with methods that assess the skeletal progression of this tumor.

METHODS

We developed a GFP-producing PCa cell line by stable transduction of PC-3 PCa cells. This PC-3 variant was used to study tumor progression in an immunocompromised mouse model. Skeletal progression of the PCa cells and the effects of pamidronate administration were evaluated radiologically, fluorometrically, and by measurement of serum tumor markers.

RESULTS

The PC-3 cells produced extensive bone lesions when injected into the tibia of immunocompromised mice. The skeletal progression of the PC-3 cells could be monitored by GFP optical imaging, X-ray, and by measurements of tumor products in serum, notably PTHrP and OPG. Pamidronate treatment reduced tumor burden as assessed at autopsy by imaging and biomarkers.

CONCLUSIONS

Pamidronate treatment exhibited anti-tumor effects that were reflected by decreases in serum PTHrP, OPG, and by GFP and radiological imaging procedures. Imaging of GFP expression enables real-time monitoring of tumor growth in the bone. PTHrP and OPG may be useful as tumor biomarkers for PCa that has metastasized to bone. This novel human PCa model can be used to study the clinical potential of diagnostic and therapeutic modalities in the skeletal progression of PCas.

Selective cholinergic denervation, independent from oxidative stress, in a mouse model of Alzheimer’s disease

Alzheimer's disease (AD) is characterized by increases in amyloid-beta (Abeta) peptides, neurofibrillary tangles, oxidative stress and cholinergic deficits. However, the selectivity of these deficits and their relation with the Abeta pathology or oxidative stress remain unclear. We therefore investigated amyloidosis-related changes in acetylcholine (ACh) and serotonin (5-HT) innervations of hippocampus and parietal cortex by quantitative choline acetyltransferase (ChAT) and 5-HT immunocytochemistry, in 6, 12/14 and 18 month-old transgenic mice carrying familial AD-linked mutations (hAPP(Sw,Ind)). Further, using manganese superoxide dismutase (MnSOD) and nitrotyrosine immunoreactivity as markers, we evaluated the relationship between oxidative stress and the ACh deficit in 18 month-old mice. Thioflavin-positive Abeta plaques were seen in both regions at all ages; they were more numerous in hippocampus and increased in number (>15-fold) and size as a function of age. A majority of plaques exhibited or were surrounded by increased MnSOD immunoreactivity, and dystrophic ACh or 5-HT axons were seen in their immediate vicinity. Counts of immunoreactive axon varicosities revealed significant decreases in ACh innervation, with a sparing of the 5-HT, even in aged mice. First apparent in hippocampus, the loss of ACh terminals was in the order of 20% at 12/14 months, and not significantly greater (26%) at 18 months. In parietal cortex, the ACh denervation was significant at 18 months only, averaging 24% across the different layers. Despite increased perivascular MnSOD immunoreactivity, there was no evidence of dystrophic ACh varicosities or their accentuated loss in the perivascular area. Moreover, there was virtually no sign of tyrosine nitration in ChAT nerve terminals or neuronal cell bodies. These data suggest that aggregated Abeta exerts an early, non-selective and focal neurotoxic effect on both ACh and 5-HT axons, but that a selective, plaque- and oxidative stress-independent diffuse cholinotoxicity, most likely caused by soluble Abeta assemblies, is responsible for the hippocampal and cortical ACh denervation.

Structural features and hypoglycaemic activity of an exopolysaccharide produced by Sorangium cellulosum

AIMS

To investigate the structural features and hypoglycaemic activity of an exopolysaccharide (EPS) produced by Sorangium cellulosum NUST06.

METHODS AND RESULTS

The chemical structure of the EPS from S. cellulosum NUST06 was determined by gas-liquid chromatography, gas chromatography (GC), GC-mass spectrometry and nuclear magnetic resonance. The EPS was composed of a beta-D-(1-->4)-glucose backbone with alpha-D-(1-->6)-mannose side chains. The molecular weight of the EPS was approx. 2x10(5) Da. Healthy and alloxan-induced diabetic mice were used in the study. Blood glucose levels of the experimental animals during the trial period were analysed by a glucose test kit based on the glucose oxidase method. When 100 and 200 mg kg(-1) day(-1) of purified EPS was orally administered for 7 days, the serum glucose in alloxan-induced diabetic mice was reduced by 35.9 and 41.4% (P<0.01), and the serum glucose in healthy mice was reduced by 27.3 and 30.1% (P<0.05), respectively.

CONCLUSIONS

The EPS produced by S. cellulosum NUST06 decreased blood glucose levels distinctly in both healthy and alloxan-induced diabetic mice.

SIGNIFICANCE AND IMPACT OF THE STUDY

To elucidated the chemical structure of the EPS from S. cellulosum NUST06 and exploited the anti-diabetic potential of the EPS.

Expression of the lacZ reporter gene in sporophytes of the seaweed Laminaria japonica (Phaeophyceae) by gametophyte-targeted transformation

The seaweed Laminaria japonica (Phaeophyceae) has a two-generation life cycle consisting of haploid gametophytes and diploid sporophytes. Female and/or male gametophytes were transformed using particle bombardment and the histological LacZ assay was performed on sporophytes generated by either parthenogenesis or inbreeding. Female gametophyte-targeted transformation resulted in similar lower efficiencies in both parthenogenetic and zygotic sporophytes, and only a chimeric expression pattern was observed. Male gametophyte-targeted transformation led to a higher efficiency, with 3.5% of the zygotic sporophytes stained completely blue (all-blue), implying the integration of lacZ at the one-cell stage. Polymerase chain reaction analysis using primers specific for a lacZ-vector juncture fragment and subsequent blotting indicated the presence of the introduced gene in the sporophytes. The method reported here has a potential for seaweed transformation using spore-based bombardment followed by the developmental process.

A Controllable and Observable Protein Cystallization Facility

A Controllable and Observable Protein Crystallization Facility (ACOP) was developed in 1999 for space experiment in the Get Away Special canister of Space Shuttle. To regulate the vapor diffusion rate, in a crystallization chamber, five cells each containing precipitant solution of different concentrations, exposed to one protein cell in turn. Five layers of chambers were overlapped coaxially. The crystallization process was observed and recorded by digital cameras. Structure of facility and result of image sequence were given.

Production of an exopolysaccharide bioflocculant by Sorangium cellulosum

AIMS

To isolate a new exopolysaccharide bioflocculant produced by the myxobacterium Sorangium cellulosum NUST06, and to characterize its chemical composition and expolysaccharide production relative to carbon source.

METHODS AND RESULTS

Exopolysaccharide levels and biomass production by S. cellulosum NUST06 were analysed relative to carbon source. Glucose in the medium at a level of 3 g l(-1) completely inhibited cell growth and exopolysaccharide production, but low concentrations of glucose (1-2 g l(-1)) could stimulate cell utilization of starch. The chemical composition and flocculating activity of the NUST06 exopolysaccharide was investigated. The flocculant comprised 38.3% proteins and 58.5% carbohydrates, of which glucose, mannose and glucuronic acid were present at 51.3%, 39.2% and 10.5%, respectively. The flocculating activity of the NUST06 flocculant depended strongly on cations.

CONCLUSIONS

It is feasible to produce an exopolysaccharide bioflocculant by the strain NUST06 in a mineral salts medium using starch as a carbon source.

SIGNIFICANCE AND IMPACT OF THE STUDY

This strain may be advantageous for commercial bioflocculant production and may enrich existing knowledge of myxobacteria.

Characterization of a bioflocculant produced by the marine myxobacterium Nannocystis sp. NU-2

The marine myxobacterium strain NU-2, which can grow on high concentrations (up to 7%) of NaCl, was isolated from a salt soil sample collected from the coast of the Huanghai Sea, China. Morphological properties and 16S rDNA sequence analysis indicated that the isolate is a novel species related to the genus Nannocystis. Nannocystis sp. NU-2 produced a new kind of flocculating substance in a starch medium with a yield of 14.8 g l(-1). The NU-2 flocculant was composed of 40.3% proteins and 56.5% polysaccharides, of which glucose, mannose and glucuronic acid were the principal constituents in the relative proportions of 5:4:1. The flocculation activity of the NU-2 flocculant depends strongly on cations such as Fe(3+) and Al(3+). When a 30 mg l(-1) FeCl(3) solution is present in kaolin clay suspension, 30 mg l(-1)of the flocculant produced a high flocculating activity value of 90%, which remained unchanged over an extensive pH range (pH 2.0-13.0). The flocculant was tested for its ability to bleach dyeing liquors, and the bleaching activities were 98.2% for acid red in 100 mg l(-1)of the flocculant and 99.0% for direct emerald blue in 50 mg l(-1)of the flocculant under test conditions. Use of the flocculant to bleach basic pink and cation emerald blue liquors was not effective.

Organic molecules acting as templates on metal surfaces

The electronic connection of single molecules to nanoelectrodes on a surface is a basic, unsolved problem in the emerging field of molecular nanoelectronics. By means of variable temperature scanning tunneling microscopy, we show that an organic molecule (C90H98), known as the Lander, can cause the rearrangement of atoms on a Cu(110) surface. These molecules act as templates accommodating metal atoms at the step edges of the copper substrate, forming metallic nanostructures (0.75 nanometers wide and 1.85 nanometers long) that are adapted to the dimensions of the molecule.

Antimetastatic efficacy of adjuvant gemcitabine in a pancreatic cancer orthotopic model

Gemcitabine is a promising new agent that has been recently studied for palliation of advanced (stage IV) unresectable pancreatic cancer. We hypothesized that adjuvant gemcitabine would reduce recurrence and metastases following surgical resection of pancreatic cancer. To test this hypothesis, we evaluated gemcitabine on a green fluorescent protein (GFP) transductant of the human pancreatic cancer cell line BxPC-3 (BxPC-3-GFP) using surgical orthotopic implantation (SOI) in nude mice. GFP enabled high resolution fluorescent visualization of primary and metastatic growth. Five weeks after SOI, the mice were randomized into three groups: Group I received exploratory laparotomy only. Group II underwent surgical resection of the pancreatic tumor without further treatment. Group III underwent tumor resection followed by adjuvant treatment with gemcitabine, 100 mg/kg every three days for a total of four doses, starting two days after resection. The mice were sacrificed at thirteen weeks following implantation and the presence and location of recurrent tumor was recorded. Gemcitabine reduced the recurrence rate to 28.6% compared to 70.6% with resection only (P = 0.02) and reduced metastatic events 58% in the adjuvant group compared to resection only. This study, demonstrating that gemcitabine is effective as adjuvant chemotherapy post-pancreatectomy, suggests this new indication of the drug clinically.

Non-saphenofemoral venous reflux in the groin in patients with varicose veins

OBJECTIVES

To investigate the incidence, clinical significance, anatomical variation and physiology of non-saphenofemoral venous reflux (non-SF reflux) in the groin.

DESIGN

Prospective study.

MATERIALS

A total of 1072 vascular diagnostic workups in 680 patients with possible venous diseases to the legs were included.

METHODS

Duplex scanning and air plethysmography.

RESULTS

A total of 1022 legs had venous diseases. Of these, 101 (9.9%) had non-SF reflux in the groin. Such reflux occurred in recurrent varicose veins (RVV) in 16.3%, in primary varicose veins (PVV) in 6.1% and in deep venous thrombosis (DVT) in 8.0%. Two patterns of reflux were distinguished: epigastric reflux from lower abdominal wall veins (71 legs) and pudendal reflux from perineal and/or gluteal veins (30 legs). Pudendal reflux was almost exclusive to women and did not occur with DVT. If there was only non-SF reflux at the groin the venous filling indices (VFI) were close to normal (1.7+/-1.0 ml/s for RVV, 1.9+/-1.2 for PVV, 1.7+/-1.0 for DVT) and no active ulcers were observed. However, if non-SF reflux was associated with saphenofemoral or other reflux the VFIs (3.3+/-2.3 ml/s for RVV, 3.8+/-1.5 ml/s for PVV) were abnormal (p <0.05) and ulcers occurred in 11/32.

CONCLUSION

Non-SF reflux in the groin is common. Such reflux may be missed at initial surgery and lead to recurrence of varicose veins. However, the venous physiological disturbance of such reflux is mild and it is not associated with ulcers unless combined with reflux at other sites in the leg.

Chronologically-specific metastatic targeting of human pancreatic tumors in orthotopic models

Pancreatic cancer is a highly metastatic disease that responds poorly to currently-available treatment. In order to better visualize and understand the chronology and specificity of metastatic targeting of pancreatic cancer, two human pancreatic cancer cell lines, expressing green fluorescent protein (GFP), were studied in orthotopic models. MIA-PaCa2-GFP and BxPC-3-GFP tumor fragments were transplanted by surgical orthotopic implantation (SOI) to the nude mouse pancreas for fluorescence visualization of the chronology of pancreatic tumor growth and metastatic targeting. BxPC-3-GFP tumors developed rapidly in the pancreas and spread regionally to the spleen and retroperitoneum as early as six weeks. Distant metastases in BxPC-3-GFP were rare. In contrast, MIA-PaCa-2-GFP grew more slowly in the pancreas but rapidly metastasized to distant sites including liver and portal lymph nodes. Regional metastases in MIA-PaCa-2-GFP were rare. These studies demonstrate that pancreatic cancers have highly specific and individual 'seed-soil' interactions governing the chronology and sites of metastatic targeting.

A highly metastatic Lewis lung carcinoma orthotopic green fluorescent protein model

The Lewis lung carcinoma has been widely used for many important studies. However, the subcutaneous transplant or orthotopic cell-suspension injection models have not allowed the expression of its full metastatic potential. A powerful new highly metastatic model of the widely-used Lewis lung carcinoma is reported here using surgical orthotopic implantation (SOI) of tumor fragments and enhanced green fluorescent protein (GFP) transduction of the tumor cells. To achieve this goal, we first developed in vitro a stable high-expression GFP transductant of the Lewis lung carcinoma with the pLEIN retroviral expression vector containing the enhanced Aequorea victoria GFP gene. Stable high-level expression of GFP was found maintained in vivo in subcutaneously-growing Lewis lung tumors. The in vivo GFP-expressing tumors were harvested and implanted as tissue fragments by SOI in the right lung of additional nude mice. This model resulted in rapid orthotopic growth and extensive metastasis visualized by GFP-expression. 100% of the animals had metastases on the ipsilateral diaphragmatic surface, contralateral diaphragmatic surface, contralateral lung parenchima, and in mediastinal lymph nodes. Heart metastases were visualized in 40%, and brain metastases were visualized in 30% of the SOI animals. Mice developed signs of respiratory distress between 10-15 days post-tumor implantation and were sacrificed. The use of GFP-transduced Lewis lung carcinoma transplanted by SOI reveals for the first time the high malignancy of this tumor and provides an important useful model for metastasis, angiogenesis and therapeutic studies.

Whole-body and intravital optical imaging of angiogenesis in orthotopically implanted tumors

The development of drugs for the control of tumor angiogenesis requires a simple, accurate, and economical assay for tumor-induced vascularization. We have adapted the orthotopic implantation model to angiogenesis measurement by using human tumors labeled with Aequorea victoria green fluorescent protein for grafting into nude mice. The nonluminous induced capillaries are clearly visible against the very bright tumor fluorescence examined either intravitally or by whole-body luminance in real time. The orthotopic implantation model of human cancer has been well characterized, and fluorescence shadowing replaces the laborious histological techniques for determining blood vessel density. Intravital images of orthotopically implanted human pancreatic tumors clearly show angiogenic capillaries at both primary and metastatic sites. A quantitative time course of angiogenesis was determined for an orthotopically growing human prostate tumor periodically imaged intravitally in a single nude mouse over a 19-day period. Whole-body optical imaging of tumor angiogenesis was demonstrated by injecting fluorescent Lewis lung carcinoma cells into the s.c. site of the footpad of nude mice. The footpad is relatively transparent, with comparatively few resident blood vessels, allowing quantitative imaging of tumor angiogenesis in the intact animal. Capillary density increased linearly over a 10-day period as determined by whole-body imaging. Similarly, the green fluorescent protein-expressing human breast tumor MDA-MB-435 was orthotopically transplanted to the mouse fat pad, where whole-body optical imaging showed that blood vessel density increased linearly over a 20-week period. These powerful and clinically relevant angiogenesis mouse models can be used for real-time in vivo evaluation of agents inhibiting or promoting tumor angiogenesis in physiological microenvironments.

A lost-wax approach to monodisperse colloids and their crystals

We report a nanoscale "lost-wax" method for forming colloids with size distributions around 5% and their corresponding colloidal crystals. Macroporous polymer templates are first prepared from a silica colloidal crystal. We then use the uniform and interconnected voids of the porous polymer to generate a wide variety of highly monodisperse inorganic, polymeric, and metallic solid and core-shell colloids, as well as hollow colloids with controllable shell thickness, as colloidal crystals. We can also uniformly deform the polymer template to alter colloidal shape and demonstrate the formation of elliptical particles with precisely controlled aspect ratios.

Construction and expression of antibody targeted plasminogen activator*

It has been known that antibody-mediated plasminogen activator will be much more specific than its parent molecular. To get a cheaper and more effective medicine for thrombolytic therapy, we used SZ51, a GMP140 specific monoclonal antibody, and a truncated single-chain urokinase to construct a novel targeted plasminogen activator. PCR was used to amplify the region of VL and VH chains from Fab of SZ51, GMP140 specific monoclonal antibody, and scu-PA-32KD(leu144-leu411) from urokinase gene, respectively. Through suitable linker and appropriate restriction sites, these fragments were joined together and inserted into the expression vector, pET-5a, via NdeI site. The recombinant protein was expressed in BL21 (DE3) plyS, a kind of E. coli. It was shown in Western-blotting and ELISA that the protein could interact with the multiple cloned antibody of urokinase. After partial purification: dialysis, Sephadex G-100, dialysis and Phenyl-Sepharose fast flow, the product had a strong fibrinolytic activity through activating plasminogen on fibrin plate. The specific activity was about 47,000 IU/mg, corresponding to 80,000 IU/mg for the part of rscu-PA-32k, and the activity could be inhibited specifically by urokinase specific antibody. Activation of plasminogen by the chimera followed Michaelis-Menten kinetics, and the K(m) was 1.08 uM.

The Escherichia coli PII signal transduction protein regulates the activities of the two-component system transmitter protein NRII by direct interaction with the kinase domain of the transmitter module

The PII signal transduction protein regulates the transcription of nitrogen-regulated genes by controlling the kinase and phosphatase activities of NRII. We used a cross-linking approach to study the interaction of the T-loop of the PII protein with NRII. Cross-linking of PII to NRII required ATP and 2-ketoglutarate, allosteric effectors known to control PII activity, and was not affected by the presence of excess nonspecific proteins such as bovine serum albumin. The purified cross-linked species appeared to consist mainly of PII trimers in which one of the three subunits was cross-linked to a single subunit of the NRII dimer; this complex had the phosphatase activity characteristic of the un-cross-linked PII-NRII complex, and had significant phosphatase activity in the absence of 2-ketoglutarate, suggesting that once PII was tethered to NRII the active conformation was stabilized. Studies with truncated forms of NRII indicated that the purified N-terminal "sensory" domain of NRII was not cross-linked to PII, nor was a polypeptide consisting of NRII residues 1-189. In contrast, polypeptides containing the kinase domain of the transmitter module of NRII (residues 190-349) were cross-linked to PII in an ATP- and 2-ketoglutarate-dependent reaction. These results indicate that PII controls NRII by interaction with the conserved kinase domain of the transmitter module.

Functional dissection of the dimerization and enzymatic activities of Escherichia coli nitrogen regulator II and their regulation by the PII protein

The dimeric two-component system transmitter protein NRII (NtrB) of Escherichia coli, product of glnL (ntrB), controls transcription of nitrogen-regulated genes by catalyzing the phosphorylation and dephosphorylation of the transcription factor NRI (NtrC). Previous studies showed that the PII signal transduction protein inhibits the kinase activity of NRII and activates its phosphatase activity. We observed that PII greatly stimulated the NRII phosphatase activity under conditions where the cleavage of ATP was prevented, indicating that the phosphatase activity did not result simply from prevention of the antagonistic NRII kinase activity by PII. Rather, PII was an activator of the phosphatase activity. To study this regulation, we examined the dimerization and enzymatic activities of NRII and various polypeptides derived from NRII, and their regulation by PII. Our results were consistent with the hypothesis that NRII consists of three domains: an N-terminal domain found only in NRII proteins and two domains formed by the conserved transmitter module of NRII, the phosphotransferase/phosphatase/dimerization (central) domain and the kinase domain. All three domains were involved in regulating the kinase and phosphatase activities of NRII. The N-terminal domain was involved in intramolecular signal transduction, and controlled access to the NRII active site for the isolated dimeric central domain added in trans. The central domain was responsible for dimerization and the phosphotransferase and phosphatase activities of NRII, but the latter activity was weak in the isolated domain and was not regulated by PII. The C-terminal kinase domain was responsible for the kinase activity. The PII protein appeared to interact with the isolated transmitter module of NRII, and not with the N-terminal domain as previously thought, since PII dramatically increased the stoichiometry of autophosphorylation of the isolated transmitter module. However, the phosphatase activity of the transmitter module of NRII was low even in the presence of PII, suggesting that the N-terminal domain was necessary for the central domain to assume the conformation necessary for potent phosphatase activity. Also, PII significantly reduced the rate of transphosphorylation of the isolated central domain by the isolated kinase domain, suggesting that PII interacts directly with the kinase domain. We hypothesize that the binding of PII to the kinase domain of NRII results in an altered conformation that is transmitted to the central and N-terminal domains; this causes the central domain to assume the conformation with potent phosphatase activity.

Robust polymer colloidal crystal photonic bandgap structures

New polymeric matrices are presented that embed organic colloidal crystalline arrays (CCA's) into mechanically stable photonic bandgap structures. We achieved these new matrices either by dispersing polystyrene CCA's with high molecular weight hydrophilic polymer [poly(ethylene glycol); (PEG)] or through in situ polymerization of hydrophilic monomers (acrylamide and acrylate functional PEG variants) about the CCA. CCA-dispersed PEG matrices exhibited strong red opalescence with a narrow peak at 614 nm and were sufficiently rigid to withstand repeated mechanical deformation. Visible photonic bandgaps also were observed from free-standing CCA composites with cross-linked poly(N, N-dimethylacrylamide) matrices. The results demonstrate the technological potential for robust organic photonic crystals.

[The recognition of the epidemic area of tsutsugamushi disease on Nan Peng Lie Island in China and the strategy of prevention]

OBJECTIVE

To investigate the region for the epidemic area of tsutsugamushi disease.

METHODS

Epidemiological studies, Orientia tsutsugamushi isolation, and preventive measures were used.

RESULTS

The region belonged to epidemic area of south subtropical zone. The main host was found Rattus norvegicu. The main biological vector was Leptotrombidium deliens. The seasonal trends of the quantity of Rattus norvegicu and Leptotrombidium deliens were consistent with the incidence change of the disease in the region. Orientia tsutsugamushi has been isolated from Rattus norvegicu and Leptotrombidium deliens. Data showed that Orientia tsutsugamushi isolated strains mainly belongs to Karp. Sero-epidemiological data showed that antibodies of Orientia tsutsugamushi are 100.0% positive in the residents of the region and 4.0% in army men. After taking comprehensive preventive measures, the incidence was descending.

CONCLUSION

Nan Peng Lie island was proved an epidemic area of tsutsugamushi disease.

Methioninase gene therapy of human cancer cells is synergistic with recombinant methioninase treatment

Results obtained over the past 40 years have demonstrated that tumor cells of all types tested have an elevated growth requirement for methioninase compared with normal cells. Recombinant methioninase (rMETase) cloned from Pseudomonas putida has been found previously to be an effective antitumor agent attributable to deprivation of the extracellular methionine source of the tumor. To degrade intracellular methioninase, we have now developed an adenoviral vector inserted with the P. putida methioninase (MET) gene (rAd-MET). The in vitro efficacy of rAd-MET was tested on the OVCAR-8 human ovarian cancer cell line, the HT1080 human fibrosarcoma cell line, and human normal fibroblasts. rAd-MET transduction of OVACAR-8 and HT1080 resulted in high levels of methioninase expression up to 10% or more of the total protein of the cells, depending on the multiplicity of infection. The IC50 of rAd-MET for OVCAR-8 cells in 96-well plates was approximately 2 x 106 plaque-forming units (pfu)/well. The IC50 of control adenovirus (control-rAd) was 4 x 10(7) pfu/well, 20 times higher than rAd-MET. In the presence of the IC50 of 2 x 10(6) pfu/well of rAd-MET, the addition of 0.025 units/ml of rMETase, which is 25% of the IC50, resulted in a 90% inhibition of tumor cell number. This indicated that rAd-MET enhanced the efficacy of rMETase. In contrast, 2 x 10(6) pfu/well of control-rAd in combination with 0.025 units/ml of rMETase had an efficacy of only 10% inhibition of cell number. The synergistic effect of the combination of rMETase and rAd-MET was quantitated by calculating the combination index (CI). The CIs for all combinations of rAd-MET and rMETase tested on OVCAR-8 were <0.7 with a mean of 0.5, indicating synergy. Similar synergy of rAd-MET and rMETase was seen on HT1080 human fibrosarcoma cells with a mean of 0.74. In contrast, the CIs of all combinations of rMETase and control adenovirus concentrations tested on both cell lines had a mean CI of approximately 1, which indicated that this combination had only an additive effect. The normal fibroblasts, on the other hand, appeared relatively resistant to the MET gene because in the presence of rMETase, 2.5 x 10(7) pfu/well of rAd-MET or control rAd had almost an identical effect on cell survival. The selectively strong synergy of rAd-MET and rMETase on cancer cells allows reduced levels of each agent to be used, thus decreasing potential side effects.

Asymmetry in the autophosphorylation of the two-component regulatory system transmitter protein nitrogen regulator II of Escherichia coli

Autophosphorylation of the homodimeric two-component system transmitter protein nitrogen regulator II (NRII; also NtrB) of Escherichia coli is the first step in the activation of nitrogen-regulated (Ntr) gene transcription. We show that the autophosphorylation of NRII was asymmetric, with phosphorylation of the first and second subunits of the dimer displaying different equilibria (under our experimental conditions K(1) approximately 0. 345, K(2) approximately 0.0044). Phosphorylation of both subunits of NRII was rapid, but the very rapid reversal of the phosphorylation of the second subunit was responsible for the equilibrium position of the reaction. Complete phosphorylation of NRII was only observed under conditions where ADP, a product of the autophosphorylation reaction, was removed by an enzymatic system. Purified, doubly phosphorylated NRII (NRII approximately P(2)) was stable in the absence of nucleotides at 0 degrees C but was dephosphorylated to the hemiphosphorylated form at 37 degrees C. In the presence of a low concentration of ADP, half of the phosphoryl groups from NRII approximately P(2) were rapidly dephosphorylated, while the remaining phosphoryl groups were slowly dephosphorylated. Experiments with heterodimers containing wild-type and mutant, nonphosphorylatable subunits suggested that the asymmetry of NRII autophosphorylation was not preexisting but resulted from the autophosphorylation of one subunit.

Venous physiology in the different patterns of recurrent varicose veins and the relationship to clinical severity

Venous function measured by air-plethysmography (APG) was compared to anatomical patterns of reflux assessed by duplex scanning and associated clinical features in 253 limbs with recurrent varicose veins following previous superficial venous surgery. The results showed that a previous history of deep venous thrombosis, previous procedure with preservation of the long saphenous vein, and a history of healed ulcer or current ulcer were each associated with worse venous function. Patterns of reflux which included multiple sites of reflux and presence of deep incompetence were also associated with worse venous function. Where there was reflux in the groin, limbs with a wide recurrent saphenofemoral junction presented the worst venous filling time and venous filling index, whereas those with reflux unrelated to the common femoral vein had nearly normal venous physiology and occurred almost exclusively in females. The other patterns of recurrence in the groin were physiologically indistinguishable from each other. In conclusion, certain patterns of reflux, clinical and operative features are associated with worse venous physiology in limbs with recurrent varicose veins. These features of recurrence with more severe physiological disturbance may necessitate a higher priority for surgical intervention.

A nude mouse model of massive liver and lymph node metastasis of human colon cancer

Liver and lymph nodes metastasis are the main causes of treatment failure for advanced colon cancer. However, currently-available animal models of human colon cancer do not demonstrate sufficient metastasis to represent highly malignant colon cancer that extensively metastasizes to these sites. A liver metastasis from a patient with highly malignant, poorly differentiated adenocarcinoma of the colon was established in nude mice by surgical orthotopic implantation to the mouse colon. The human origin of the tumor growing in nude mice was confirmed by in situ hybridization of human DNA. After 20 passages from the first implantation, massive liver and lymph nodes metastasis, occurred in 100% of the transplanted animals. Lymph nodes metastasis were found at the sites of lymph node drainage of the liver: celiac, portal and mediastinal lymph nodes. However no mesenteric and retroperitoneal nodes or lung tissue metastases were observed. Our data suggest that the mediastinal, celiac and hepatic lymph nodes metastases are derived form the liver metastasis, confirming the concept of metastasis of metastases or "remetastasis" of colon cancer.

Whole-body optical imaging of green fluorescent protein-expressing tumors and metastases

We have imaged, in real time, fluorescent tumors growing and metastasizing in live mice. The whole-body optical imaging system is external and noninvasive. It affords unprecedented continuous visual monitoring of malignant growth and spread within intact animals. We have established new human and rodent tumors that stably express very high levels of the Aequorea victoria green fluorescent protein (GFP) and transplanted these to appropriate animals. B16F0-GFP mouse melanoma cells were injected into the tail vein or portal vein of 6-week-old C57BL/6 and nude mice. Whole-body optical images showed metastatic lesions in the brain, liver, and bone of B16F0-GFP that were used for real time, quantitative measurement of tumor growth in each of these organs. The AC3488-GFP human colon cancer was surgically implanted orthotopically into nude mice. Whole-body optical images showed, in real time, growth of the primary colon tumor and its metastatic lesions in the liver and skeleton. Imaging was with either a trans-illuminated epifluorescence microscope or a fluorescence light box and thermoelectrically cooled color charge-coupled device camera. The depth to which metastasis and micrometastasis could be imaged depended on their size. A 60-microm diameter tumor was detectable at a depth of 0.5 mm whereas a 1, 800-microm tumor could be visualized at 2.2-mm depth. The simple, noninvasive, and highly selective imaging of growing tumors, made possible by strong GFP fluorescence, enables the detailed imaging of tumor growth and metastasis formation. This should facilitate studies of modulators of cancer growth including inhibition by potential chemotherapeutic agents.