Xenograft Tumors Vascularized with Murine Blood Vessels May Overestimate the Effect of Anti-Tumor Drugs: A Pilot Study

Recent evidence demonstrated that endothelial cells initiate signaling events that enhance tumor cell survival, proliferation, invasion, and tumor recurrence. Under this new paradigm for cellular crosstalk within the tumor microenvironment, the origin of endothelial cells and tumor cells may have a direct impact on the pathobiology of cancer. The purpose of this pilot study was to evaluate the effect of endothelial cell species (i.e. murine or human) on xenograft tumor growth and response to therapy. Tumor xenografts vascularized either with human or with murine microvascular endothelial cells were engineered, side-by-side, subcutaneously in the dorsum of immunodefficient mice. When tumors reached 200 mm³, mice were treated for 30 days with either 4 mg/kg cisplatin (i.p.) every 5 days or with 40 mg/kg sunitinib (p.o.) daily. Xenograft human tumors vascularized with human endothelial cells grow faster than xenograft tumors vascularized with mouse endothelial cells (P<0.05). Notably, human tumors vascularized with human endothelial cells exhibited nuclear translocation of p65 (indicative of high NF-kB activity), and were more resistant to treatment with cisplatin or sunitinib than the contralateral tumors vascularized with murine endothelial cells (P<0.05). Collectively, these studies suggest that the species of endothelial cells has a direct impact on xenograft tumor growth and response to treatment with the chemotherapeutic drug cisplatin or with the anti-angiogenic drug sunitinib.     

Estimated Glomerular Filtration Rate and Proteinuria Are Separately and Independently Associated with the Prevalence of Atrial Fibrillation in General Population

Background

Both, proteinuria and a decline in glomerular filtration rate (GFR) are associated with greater cardiovascular mortality. However, few studies have explored that proteinuria and lower GFR are related with prevalent atrial fibrillation (AF).

Methods

This cross-sectional study was based on annual health check-up program of community-based population in Gunma, Japan from April 2011 to March 2012. A total of 20,019 adult participants were included. AF was ascertained by a standard 12-lead electrocardiogram. Cross-sectional association and correlates with prevalent AF were examined using multivariable logistic regression analysis.

Results

The overall prevalence of AF was 0.6% (2.2 % in participants with eGFR < 60 mL▪min^-1･1.73m^-2, 0.4% and 0.2% in those with eGFR 60 to 89 and ≧90 mL▪min^-1･1.73m^-2, p for trend <0.001). The multivariable odds ratio (OR) for AF was 2.86 (95 % CI 1.16 - 7.08, p<0.001) for eGFR< 60 mL▪min^-1▪1.73m^-2 versus eGFR≧ 90 mL▪min^-1▪1.73m^-2. This association remained significant with further adjustment for proteinuria. In addition, proteinuria was also strongly associated with increased prevalence of AF (OR 2.96, 95 % CI 1.55-5.68, p<0.001), an association that remained significant after adjustment for eGFR.

Conclusions

Proteinuria and lower eGFR are separately and significantly associated with prevalence of AF independent of well-established risk factors for AF in general population.     

Degradation of Abies veitchii wave-regeneration on Mt. Misen in Ohmine Mountains: effects of sika deer population

How has the degradation of Abies veitchii wave-regeneration occurred under the sika deer (Cervus nippon) pressure? We conducted tree census and ground vegetation survey in a 1 ha plot in Mt. Misen (Nara prefecture, Japan). We found 15 tree species (over 50 cm in height). Abies accounted for 60.0 % of all living trees, and 46.9 % of Abies were damaged (herbivory, bark stripping and/or fraying) by deer. Spatial distribution of Abies trees showed Abies-wave, although there were few saplings in the dieback zone. Estimated deer population density in 2009 was 57.3 head/km². Number of living Abies and standing dead conifer trees, and ground vegetation cover for each quadrat (5 × 5 m) were used to assign the quadrats into 6 clusters. The hierarchical clustering-approach revealed that living Abies distributed mainly on the moss and/or Carex fernaldiana dominated quadrats, but did not on the Dennstaedtia scabra, or Brachypodium sylvaticum dominated quadrats. While standing dead conifer trees distributed mainly on the Carex dominated quadrats, they hardly occur on the moss, the Dennstaedtia or the Brachypodium dominated quadrats. Regeneration of Abies tree and thus the wave-regeneration is hindered for now owing to deer herbivory and bark-stripping. The ground vegetation under the dieback zone has changed from the moss and/or the Carex dominated one to the Carex, the Dennstaedtia or the Brachypodium covered vegetation with the canopy remained open and without Abies regeneration.     

Isolation,Purification, and Properties of Lytic Enzyme from Polysphondylium pallidum Myxamoebae

Two lytic enzymes (enzyme I and enzyme II) that lysed Micrococcus lysodeikticus were isolated from the crude extract of Polysphondylium pallidum myxamoebae grown in the presence of Klebsiella aerogenes by precipitation with protamine sulfate and by chromatography on DEAE-Sepharose CL-6B. Enzyme I was further purified by gel filtration on a Superose12 column, and enzyme II by chromatography on a MonoQ HR 5/5 column and gel filtration on a Superose12 column. Enzyme I was a basic protein, while enzyme II was acidic. The molecular weights of enzyme I and II were about 14,000 and 22,000, respectively by SDS-polyacrylamide gel electrophoresis. Optimum pHs for the activity were 5.0 for enzyme I and between 3.5 and 4.0 for enzyme II. The maximum activity of enzyme I and II was obtained at 65°C and 45°C to 55°C and at ionic strength of 0.0075 to 0.03 and 0.06, respectively. Both enzymes cleaved the glycosidic bond of β(1,4)-N-acetylmuramyl-acetylglucosamine of the cell wall peptidoglycan of Micrococcus lysodeikticus. These results indicate that the two lytic enzymes of Polysphondylium pallidum myxamoebae are N-acetylmuramidases.     

A Cytochrome c Peroxidase Isolated from Thiobacillus thiooxidans

High phytin containing particles were isolated from rice bran by a combination of a differetial centrifugation and an aqueous two phase system, using dextran 500 and polyethylene glycol 6000. The isolated particles consisted mainly of phytic acid, potassium and magnesium. The chemical composition and electron microscopic observation of the isolated particles confirmed that the electron dense material, which is embedded in aleurone particles of matured rice grains, is potassium and magnesium salts of phytic acid.     

Gluconate Metabolism by a Thiamine-requiring Species of Corynebacterium

A thiamine-requiring strain of Corynebacterium was found to accumulate a ketopentose extracellularly from gluconate. The ketopentose was isolated from the culture medium and identified as d-ribulose. The accumulation of d-ribulose was significantly influenced by the concentration of thiamine in the medium. The maximum yield of d-ribulose was obtained at a thiamine concentration of 10 μg per liter, whereas good growth was favored at thiamine concentrations greater than 50 μg per liter. The accumulation of d-ribulose reached the concentration of 9.5 mg per ml after cessation of cell growth in shake culture at 30°C in a medium containing 6% potassium gluconate as a carbon source.     

Production of Polyalcohol by a Corynebacterium sp.

A gluconate-utilizing strain of Corynebacterium was found to be capable of utilizing aldopentoses and producing corresponding pentitols when pentoses were added to the medium containing gluconate as a carbon source during the cultivation of the organism.

Pentitols produced from d-xylose, l-arabinose, and d-ribose were isolated from the cultured medium and identified as xylitol, l-arabitol, and ribitol, respectively.

The pentitol production was significantly influenced by the concentration of gluconate in the initial medium and that of pentose added to the medium during the cultivation.

The amount of xylitol, l-arabitol, and ribitol reached 69 mg/ml, 60 mg/ml, and 32 mg/ml, respectively, after 14 days of incubation when pentoses were added to the medium containing 9.6% potassium gluconate to give a final concentration of 150 mg/ml.     

Physiological Studies on Thiobacilli

NADPH-cytochrome c oxidoreductase obtained from the cells of Thiobacillus thiooxidans displayed the pH optimum of 8.7 and was completely inactivated by heating at 60°C for 10 min. Enzymatic activity was proportional to protein concentration and linear with time. The Km for NADPH was found to be 2.13 × 10^?5 m. The enzyme was specific for NADPH and transferred electrons to cytochrome c and some dyes. p-Chloromercuribenzoate, EDTA and acryflavin inhibited the reductase activity.     

Synthesis of Theaspirone

β-Ionone (I) was oxidized to 2,3-epoxy-/β-ionone (II), which was converted to 2,3-dihydroxy-β-ionone (III) by acid treatment. III was reduced to 4-(1,2-dihydroxy-2,6,6-trimethylcyclohexan-1-yl)-2-butanol (V), which was converted, by oxidation, to cis- and trans-theaspirone (1-oxa-8-oxo-2,6,10,10-tetramethyl spiro-(4,5)-6-decene) (VII-A), (VII-B) and dihydroactinidiolide (2-hydroxy-2,6,6-trimethylcyclohexyliden-1-acetic acid lactone) (IX).     

Inhibition Site of Cupric Ions on the Growth of Thiobacillus ferrooxidans on Sulfur-salts Medium

The cDNA sequence coding for tuna growth hormone (tGH) was placed under the control of the repressible acid phosphatase (PHO5) promoter of a yeast, Saccharomyces cerevisiae, in an expression plasmid, pAM82. The yeast cells transformed with the plasmid synthesized tGH only when the cDNA was attached to the vector through a synthetic oligonucleotide linker having a similar sequence to the 5′-flanking region of the PHO5 structural region. The amount of tGH produced in yeast cells accounted for more than 3% of the total cellular protein and the product was immunologically identified as tGH by Western blotting using polyclonal antibodies specific to tGH.