Anatomic site variability in rat skeletal uptake and desorption of fluorescently labeled bisphosphonate

OBJECTIVES

Bisphosphonates commonly used to treat osteoporosis, Paget's disease, multiple myeloma, hypercalcemia of malignancy and osteolytic lesions of cancer metastasis have been associated with bisphosphonate-associated jaw osteonecrosis (BJON). The underlying pathogenesis of BJON is unclear, but disproportionate bisphosphonate concentration in the jaw has been proposed as one potential etiological factor. This study tested the hypothesis that skeletal biodistribution of intravenous bisphosphonate is anatomic site-dependent in a rat model system.

MATERIALS AND METHODS

Fluorescently labeled pamidronate was injected intravenously in athymic rats of equal weights followed by in vivo whole body fluorimetry, ex vivo optical imaging of oral, axial, and appendicular bones and ethylenediaminetetraacetic acid bone decalcification to assess hydroxyapatite-bound bisphosphonate.

RESULTS

Bisphosphonate uptake and bisphosphonate released per unit calcium were similar in oral and appendicular bones but lower than those in axial bones. Hydroxyapatite-bound bisphosphonate liberated by sequential acid decalcification was the highest in oral, relative to axial and appendicular bones (P < 0.05).

CONCLUSIONS

This study demonstrates regional differences in uptake and release of bisphosphonate from oral, axial, and appendicular bones of immune deficient rats.

Effects of cyclic AMP on development and secondary metabolites of Monascus ruber M-7

AIM

To study effects of cyclic adenosine monophosphate (cAMP) on development and secondary metabolites of Monascus ruber M-7.

METHODS AND RESULTS

Plate culture, liquid-state fermentation (LSF) and solid-state fermentation (SSF) were used to evaluate effects of cAMP on colonial growth, spore formation and polyketide production of Strain M-7. The results revealed that the variation trends of colonial sizes, numbers of sexual spores and red pigment contents of M-7 were in a dose-dependent manner. And generally they increased and decreased with cAMP concentrations in the ranges of low cAMP concentrations and high cAMP concentrations, respectively. But the variation trends of numbers of asexual spores and citrinin production in both LSF and SSF were opposite to those of colonial sizes, sexual sporulation and red pigment.

CONCLUSIONS

The regulation of cAMP on development and secondary metabolites in Strain M-7 was in a dose-dependent pattern. And red pigment might convert to citrinin under changing cAMP concentrations.

SIGNIFICANCE AND IMPACT OF THE STUDY

The effects of cAMP on Strain M-7 in SSF give a new clue to enhance beneficial polyketides and reduce citrinin produced by M. ruber.

First Report of Tobacco curly shoot virus Infecting Pepper in China

In recent years, whitefly-transmitted begomovirues (family Geminiviridae) have caused severe leaf curl disease on tobacco and tomato in southern China, but have not been found on pepper. In August 2009, pepper plants (Capsicum frutescens) grown in the field in Panzhihua City of Sichuan Province (southwestern China), from where the occurrence of begomoviruses has not been reported previously, showed stunting, leaf yellowing, and mild curling symptoms. To identify possible begomoviruses, total DNA was extracted from three infected pepper plants (SC117, SC118, and SC119) with typical symptoms. Using degenerate primer pair PA/PB specific for members of the genus Begomovirus (2), a 500-bp DNA fragment covering parts of the intergenic region and V2 gene of the genome of begomoviruses was amplified from all samples. No amplification was observed from healthy plant extracts. The PCR product from SC118 was cloned and two clones were chosen to be sequenced. Alignment of the partial DNA sequences revealed that the cloned products from isolate SC118 were nearly identical (98.5%) and most closely related to Tobacco curly shoot virus isolate Y35 (TbCSV-[China:Yunnan 35:2001]; Accession No. AJ420318) (96.9 and 97.3% identity, respectively). Therefore, the entire genome of isolate SC118 was sequenced. Overlap primers TbCSV-F(5'-CCGCCGTCTCAACTTCGACAG-3') and TbCSV-R(5'-ATCTGCTGGTCGCTTCGACAT-3') were designed to amplify the full-length genome of SC118. The complete genome sequence of SC118 was determined to be 2,746 nucleotides (Accession No. GU001879) long, with two open reading frames (ORFs) in the virion-sense strand and four ORFs in the complementary-sense strand, typical of the Old World begomoviruses. A comparison with other reported sequences of begomoviruses shows that the genome of SC118 shares the highest nucleotide sequence identity (99.7%) with TbCSV-[China:Yunnan 35:2001]. When PCR was used to detect TbCSV from the other two isolates (SC117 and SC119) with TbCSV specific primer pair Y35F1 and Y35+10R (4), which amplified the fragment covering the whole C2 and C3 genes and the partial C1 and V1 genes of the genome of TbCSV, an amplicon of approximately 1.0 kb was obtained from all samples. To determine whether a satellite molecule was associated with the three virus isolates, a universal betasatellite abutting primer pair (beta01 and beta02) was used (1). No amplification product was detected. In previous studies, it was demonstrated that only 11 isolates were associated with betasatellites among 39 TbCSV-infected, field-collected samples (3), and betasatellites could be associated with noncognate begomoviruses (4). Therefore, the three isolates examined in this study are too few to come to a conclusion that betasatellites are not associated with TbCSV infection of pepper plants. A detailed search for the presence of betasatellites needs to be conducted to draw a definitive conclusion. The above results confirmed that samples SC117, SC118, and SC119 were infected by TbCSV. To our knowledge, this is the first report of TbCSV on pepper in China. References: (1) R. W. Briddon et al. Mol. Biotechnol. 20:317, 2002. (2) D. Deng et al. Ann. Appl. Biol. 125:327, 1994. (3) Z. Li et al. Phytopathology 95:902, 2005. (4) L. Qing et al. Phytopathology 99:716, 2009.

First Report of Tobacco mosaic virus in Abutilon theophrasti in China

Velvetleaf (Abutilon theophrasti Medic), a tall, fecund, self-fertile annual plant in the family Malvaceae, is widely grown in China as a fiber crop and for its medicinal properties. In July of 2008, we observed diffuse chlorotic and necrotic spots on the oldest leaves of velvetleaf plants in the field in Shanxi Province. Sap extracts from six symptomatic plants were tested by direct antigen coated ELISA using polyclonal antibodies specific to Potato virus Y (PVY) and monoclonal antibodies specific to Tomato mosaic virus (ToMV), Cucumber mosaic virus (CMV), and Tobacco mosaic virus (TMV). Five of the six samples were negative for ToMV, CMV, and PVY but positive for TMV. Double-stranded RNA extracted from leaves of the five velvetleaf plants was used as template for reverse transcription (RT)-PCR as described by Krajačića et al. (1) and Li et al. (2) with some modifications. One-step RT-PCR was performed using a Quant One Step RT-PCR Kit (TIANGEN BIOTECH CO., LTD., Beijing, China) with sense (5'-CTGTTTAGCCGGTTTGGT-3'), and antisense (5'-TCCCTTTACGGACATCAC-3') primers (3) designed to specifically amplify a fragment of the movement protein coding region of TMV. The expected 470-bp fragments were amplified from dsRNA from these five plants and the amplicon from each plant was cloned and sequenced (GenBank Accession No. FJ873800). Comparisons of a consensus sequence derived from the five amplicons with the nucleotide sequences available in the NCBI database using BLAST showed 99% identity with TMV from South Korea (GenBank Accession No. AB354955) and Spain (Accession No. AJ308692) and 98% with TMV from China (Accession No. AF165190). The serological, RT-PCR results and sequence data revealed that these velvetleaf plants were infected by TMV. On the basis of the serological analysis and genome sequence comparisons, this isolate was tentatively designated as TMV-Velvetleaf. To our knowledge, this is the first report of TMV in Abutilon theophrasti Medic in China. References: (1) M. Krajačić et al. J. Chromatogr A. 1144:111, 2007. (2) H. Li et al. Agric. Sci. Chin. 6:86, 2007. (3) Y. B. Niu et al. Chin. Biotechnol. 29:76, 2009.

Genetic determinants of symptoms on viral DNA satellites

Begomovirus-DNA-beta disease complexes induce different symptom phenotypes in their hosts. To investigate the genetic determinants of the phenotypic differences, Nicotiana spp. and tomato plants were inoculated with infectious clones of Tobacco curly shoot virus (TbCSV)/TbCSV DNA-beta (TbCSB) and Tomato yellow leaf curl China virus (TYLCCNV)/TYLCCNV DNA-beta (TYLCCNB) pseudorecombinants and showed that TYLCCNB induced characteristic vein-thickening and enation symptoms, while TbCSB only slightly exacerbated the leaf-curling symptoms, regardless of the helper virus being used. The roles of DNA-beta-encoded betaC1 and a 430-nucleotide fragment containing the A-rich region and the putative betaC1 promoter region of the betaC1 gene (referred to as AP) in symptom development were further investigated by constructing hybrid satellites in which the betaC1 coding region or AP was exchanged between the two satellite molecules. A TYLCCNB hybrid with TbCSB betaC1 lost the ability to elicit the vein-thickening and enation phenotypes. TbCSB hybrids containing the TYLCCNB betaC1 or AP fragment failed to induce the characteristic vein thickening and enations. A TYLCCNB hybrid having the TbCSB AP fragment produced the enations, but the number of enations was less and their sizes were reduced. Differently from the phloem-specific pattern of the TYLCCNB promoter, a full-length fragment upstream of the TbCSB betaC1 gene confers a constitutive beta-glucuronidase expression pattern in transgenic tobacco plants. The above results indicate that the DNA-beta-encoded betaC1 protein is the symptom determinant, but the promoter of the betaC1 gene has influence on symptom production.

Trans-replication of, and competition between, DNA beta satellites in plants inoculated with Tomato yellow leaf curl China virus and Tobacco curly shoot virus

Tomato yellow leaf curl China virus (TYLCCNV) Y10 isolate (Y10) and Tobacco curly shoot virus (TbCSV) Y35 isolate (Y35), both obtained from Yunnan Province, were each found to be associated with a distinct species of satellite DNA (DNA beta). Here, we demonstrate that both Y10 DNA beta (Y10beta) and Y35 DNA beta (Y35beta) were stably trans-replicated by the noncognate Begomovirus, although the noncognate DNA beta accumulated in plants at a lower level than did the cognate DNA beta. In Nicotiana benthamiana and N. glutinosa plants agroinoculated with Y10+Y10beta+Y35beta or with Y35+Y35beta+Y10beta, all components accumulated in the early stages of infection but, at later stages, the noncognate DNA beta decreased in relative concentration and was undetectable at 80 to 120 days after inoculation. The helper viruses and cognate DNA beta species persisted at higher levels throughout the experiments. When the initiation codon of the betaC1 gene of the cognate DNA beta was mutated, the dominance of the cognate over the noncognate DNA beta in mixed infections was unimpaired. These results imply that the cognate DNA beta competes with the noncognate DNA beta and that the ability for selective maintenance of DNA beta is not controlled by the betaC1 protein.

Varied line spacing plane holographic grating recorded by using uniform line spacing plane gratings

Uniform line spacing plane gratings are introduced into a recording system to generate aspherical wavefronts for recording varied line spacing plane holographic gratings. Analytical expressions of groove parameters are derived to the fourth order. A ray-tracing validation algorithm is provided based on Fermat's principle and a local search method. The recording parameters are optimized to record a varied line spacing plane holographic grating with the aid of derived analytical expressions. A design example demonstrates the exactness of the analytical expressions and the superiority of recording optics with auxiliary gratings.

The recombinant nonstructural polyprotein NS1 of porcine parvovirus (PPV) as diagnostic antigen in ELISA to differentiate infected from vaccinated pigs

To differentiate pigs infected with porcine parvovirus (PPV) from those vaccinated with inactivated whole-virus vaccine, an enzyme-linked immunosorbent assay (ELISA) based on detection of a nonstructural polyprotein 1 (NS1) was developed. A threshold of 0.23 optical density units was established and the assay had high specificity (100), sensitivity (88), accuracy (90) and positive predictive value (100) using haemagglutination inhibition as the standard method. A reproducibility test revealed that the coefficients of variation of sera within-plates and between-run were less than 10%. The assay showed no cross-reactivity with antibodies to porcine reproductive respiratory syndrome virus, pseudorabies virus, foot and mouth disease virus, Actinobacillus pleuropneumoniae, Toxoplasma or Chlamydia. Sera obtained from pigs infected with PPV reacted with recombinant NS1 protein in the ELISA. Sera from pigs vaccinated with inactivated whole virus did not recognize this protein in the ELISA. In contrast, antibodies against PPV whole virus were present in both PPV-infected and vaccinated animals. Serum conversion against NS1 was first detected 10 days after infection and NS1-specific antibodies were detectable up to half a year post infection. In conclusion, the PPV-NS1 ELISA can differentiate PPV-infected versus inactivated PPV-vaccinated pigs and could be applied in disease diagnosis and surveillance.

OxLDL upregulates growth-regulation oncogene alpha expression in human endothelial cells

OBJECTIVE

To explore the effect of oxLDL on CXC chemokine growth-regulated oncogene alpha (GRO alpha) expression in human endothelial cells and the possible functional significance of the effect.

METHODS

LDL was isolated by sequential ultracentrifugation and oxidized to oxLDL. Reverse transcription-polymerase chain reaction with GAPDH as internal standard was applied and CXC chemokine GRO alpha mRNA in endothelial ECV304 cells was examined. ELISA was used to determine GRO alpha protein expression on ECV304 cells surface and in the medium. With static cell adhesion assays, the physiological significance of elevated GRO alpha expression was tested.

RESULTS

OxLDL, not LDL, treatment of ECV304 cells significantly induced the expression of GRO alpha mRNA that was not detectable in untreated cells. Induction of expression was first evident at 1 h, became maximal at 2 h, and was substantially decreased by 4 h. In a concentration- and time-dependent manner, oxLDL, and not LDL, induced a significant upregulation of GRO alpha surface expression in ECV304 cells that was at a barely detectable level in unstimulated ECV304 cells. GRO alpha protein in the medium did not change significantly. Exposure of ECV304 cells to 40 micrograms protein/ml oxLDL for 24 h resulted in a marked increase in the number of U937 cells bound to ECV304 cells and antibodies to GRO alpha inhibited adhesion.

CONCLUSION

OxLDL functionally upregulated GRO alpha expression in endothelial cells.

[Production of monoclonal antibodies to broad bean wilt virus and application in virus detection]

Six hybridoma cell lines secretion monoclonal antibodies(MAbs) against broad bean wilt virus(BBWV) were produced by fusing mouse myeloma cells(SP 2/0) with spleen cells from BAL B/c immunized by the BBWV particles. The hybridoma cell lines secreted MAbs stably after cultured in vitro for 3 months or stored in liquid nitrogen and then revived for several times. The titres of ascitic fluids of six MAbs ranged from 1:256,000 to 1:640,000 when measured by indirect ELISA. In agarose gel immunodiffusion test, it showed that the six MAbs represented the same isotype of murine antibodies, IgG1. Six MAbs could detect 4 tested BBWV isolates, but didn't crossreact with other 5 plant viruses. The result of Western blot showed that all the six MAbs can react with the 44.7 kD large coat protein subunit of BBWV. This is the first report of production of MAbs against BBWV.

Ultrastructural localization of insulin-like growth factor-2 (IGF-2) to the secretory granules of insulin cells: a study in normal and diabetic (GK) rats

By using biochemical and light-microscopical techniques, insulin-like growth factor-2 (IGF-2) has recently been found in adult pancreas, co-localized immunohistochemically with insulin in the islet B-cells. The purpose of this study was to trace IGF-2 immunoreactivity (IR) at the ultrastructural level in normal and diabetic Goto-Kakizaki (GK) rats. Using a pre-embedding technique and immuno-gold-silver staining, IGF-2 antibody binding was localized exclusively to the halo of a subset of secretory beta-granules in normal rats. Insulin IR occurred more frequently in the granules. GK rats had, in addition to normal-looking islets, some islets with irregular shape and an increased amount of fibrous tissue, so-called "starfish-shaped" islets. In these, beta-granules were usually found, but most of the B-cells were also occupied by large, usually electron-translucent vesicles, some resembling crinophagic bodies, i.e., the sign of intracellular degradation of secretory granules. In starfish-shaped islets, IGF-2 IR was localized to the halo of beta-granules, as in GK islets with normal appearance. Occasionally, IGF-2 IR was also found in the cytoplasm and even in adjacent fibroblasts. Insulin IR was restricted to beta-granules. Because the lysosomes have IGF-2 receptors, the presence of IGF-2 peptide in secretory granules could explain why some granules are guided to lysosomes for degradation.

Generalized immune activation in pulmonary tuberculosis: co-activation with HIV infection

Parameters of immune activation/differentiation were studied in a group of newly diagnosed HIV- and HIV+ pulmonary tuberculosis (TB) patients. Compared with controls, HLA-DR expression on both CD4 and CD8 T cells from the HIV- TB patients was approximately doubled; HLA-DR on T cells from the HIV+ group was tripled. The monocytes from both groups of patients expressed abnormally high levels of the Fc gamma receptors I and III. Serum levels of tumour necrosis factor-alpha (TNF-alpha), neopterin and beta 2-microglobulin were increased in HIV- and even more so in HIV+ TB patients. The expression of HLA-DR on T cell subsets and of Fc gamma R on monocytes correlated with each other, but not with serum activation markers. This pattern of non-specific activation during TB infection may be associated with enhanced susceptibility to HIV infection.

Primary isolates of human immunodeficiency virus type 1 are relatively resistant to neutralization by monoclonal antibodies to gp120, and their neutralization is not predicted by studies with monomeric gp120

A panel of anti-gp120 human monoclonal antibodies (HuMAbs), CD4-IgG, and sera from people infected with human immunodeficiency virus type 1 (HIV-1) was tested for neutralization of nine primary HIV-1 isolates, one molecularly cloned primary strain (JR-CSF), and two strains (IIIB and MN) adapted for growth in transformed T-cell lines. All the viruses were grown in mitogen-stimulated peripheral blood mononuclear cells and were tested for their ability to infect these cells in the presence and absence of the reagents mentioned above. In general, the primary isolates were relatively resistant to neutralization by the MAbs tested, compared with the T-cell line-adapted strains. However, one HuMAb, IgG1b12, was able to neutralize most of the primary isolates at concentrations of < or = 1 microgram/ml. Usually, the inability of a HuMAb to neutralize a primary isolate was not due merely to the absence of the antibody epitope from the virus; the majority of the HuMAbs bound with high affinity to monomeric gp120 molecules derived from various strains but neutralized the viruses inefficiently. We infer therefore that the mechanism of resistance of primary isolates to most neutralizing antibodies is complex, and we suggest that it involves an inaccessibility of antibody binding sites in the context of the native glycoprotein complex on the virion. Such a mechanism would parallel that which was previously postulated for soluble CD4 resistance. We conclude that studies of HIV-1 neutralization that rely on strains adapted to growth in transformed T-cell lines yield the misleading impression that HIV-1 is readily neutralized. The more relevant primary HIV-1 isolates are relatively resistant to neutralization, although these isolates can be potently neutralized by a subset of human polyclonal or monoclonal antibodies.

Restriction fragment length polymorphisms of Anisakinae larvae

The analysis of restriction fragment length polymorphisms (RFLPs) was applied to distinguish several kinds of Anisakinae larvae, Anisakis larvae (type I) collected from two different paratenic hosts, Anisakis larvae (type II) and Contracaecum larvae. The patterns of the two different paratenic host-derived DNA of Anisakis larva (I) were exactly the same in hybridized fragments generated by six endonucleases. The quite different patterns in RFLPs of genomic DNA were observed among the Anisakis larva (I), Anisakis larva (II) and Contracaecum larvae. The results suggest that the RFLPs analysis may be useful for distinguishing Anisakinae larvae and clarifying the relationships between Anisakis larvae and their adult worms.