Purification of lectin from larvae of the fly, Musca domestica, and in vitro anti-tumor activity in MCF-7 cells

A new lectin was purified from larvae of the fly, Musca domestica L. (Diptera: Muscidae) (MLL-2, 38 kDa) using affinity chromatography and HPLC. Anti-tumor activity of MLL-2 was demonstrated by its inhibition of proliferation of human breast cancer (MCF-7) cells in a time-and dose-dependent manner. The results of acridine orange staining indicated that MLL-2 caused apoptosis in MCF-7 cells. DNA fragmentation in MCF-7 cells has been detected by TUNEL. Flow cytometric analysis also demonstrated that MLL-2 caused dose-dependent apoptosis of MCF-7 cells through cell arrest at G2/M phase. The MLL-2 induced a sustained increase in concentration of intracellular free calcium. Western blot revealed that MLL-2 induced apoptosis in MCF-7 cells was associated with typical apoptosis proteins in the mitochondrial pathway. In addition, the caspase-3 activity in MCF-7 cells treated with MLL-2 for 48 hours was significantly increased compared to controls (407.4 ± 3.0 vs. 1749.2 ± 6.0, P <0.01). Since MLL-2 induced apoptosis in MCF-7cells the mitochondrial pathway may be the main pathway of antitumor activity.

Purification and characterization of a new D-galactose-specific lectin from the housefly, Musca domestica, and its antiproliferative effect on human K562 and MCF-7 tumor cells

In the present work, a D-galactose-specific lectin with novel N-terminal sequence was purified from Musca domestica L. (Diptera: Muscidae) pupae. The purification was performed using affinity chromatography, ultra-filtration, and HPLC. The haemagglutinating activity of M. domestica lectin was specifically inhibited by D-galactose. The haemagglutinating activity of this lectin was stable at temperatures up to 65 degrees C and in pH ranging from 4 to 8. Salts including FeCl(3) and MnCl(2) inhibited the haemagglutinating process, whereas NaCl, KCl, CaCl(2), MgCl(2), ZnCl(2), and AlCl(3) did not. By SDS-PAGE, purified M. domestica pupae lectin yielded a single band with a molecular weight of 40 kDa, with or without reduction of beta-mercaptoethanol, and it could be stained with Alcian Blue 8 GX. The morphology of purified lectin was observed by atomic force microscopy, which indicated that M. domestica lectin was an 8.27 nm high, globular shaped glycoprotein with a 1.41 nm high polysaccharide chain. In addition, antiproliferative activity of this lectin against tumor cells K562 and MCF-7 was determined with a colorimetric assay using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide, which showed that the antiproliferative process was time- and dose-dependent with an IC(50) of 5.7 and 6.7 at 24 h, 5.5 and 6.4 at 36 h, 5.2 and 6.5 microM at 48 h, respectively.

Regeneration of foreign genes co-transformed plants of Medicago sativa L by Agrobacterium rhizogenes

Gene encoding sulphur amino acid-rich protein (HNP) and rol genes were transferred into Medicago sativa L (alfalfa) mediated by Agrobacterium tumafeciens. Regeneration of transgenic plants was induced successfully from hairy root tissue of cotyledon in alfalfa. Cotyledon tissues were an ideally transformed recipient. There was a negative correlation between age of hairy roots and embryogenesis frequency in alfalfa. Production of co-transformed plants with greater yield and super quality was important for development of new alfalfa varieties.

New mutations in the transglutaminase 1 gene in three families with lamellar ichthyosis

BACKGROUND

Autosomal recessive lamellar ichthyosis (LI) is a severe skin disorder characterized by generalized hyperkeratosis. Gene mutation in transglutaminase 1 (TGM1), which mediates cross-links in the formation of the cell envelope during terminal differentiation of epidermis, has been identified as a cause of LI.

OBJECTIVES

To determine mutations of TGM1 gene in three Chinese families with LI.

METHODS

The TGM1 gene was sequenced to identify disease-causing mutations in the three families with LI. One of the results was confirmed by using reverse transcriptase PCR and in situ hybridization. An in situ transglutaminase (TGase) 1 assay was performed to estimate TGase 1 activity in the patients' skin.

RESULTS

Four novel mutations of keratinocyte TGase1 (Q203X, D254N, R687H and IVS4 + 1G-->T) were found in the three families. No TGase 1 mRNA was detected in patient skin using RT-PCR and in situ hybridization, and the in situ TGase assay showed that there was no or decreased TGase 1 activity in patient skin.

CONCLUSIONS

Our findings suggest that four novel mutations in TGM1 gene result in decrease or absence of TGase activity in the skin and, as a consequence, cause the phenotype of LI.

BNIP3L (Nix) expression in colon cancer

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Background: Microenvironmental adaptation to hypoxic conditions is critical for a cell to survive in a growing solid tumor. BNIP3L (Nix) mediates apoptosis during hypoxia in cancer cell lines, and Nix knockdown promotes tumor growth in-vivo through decreased apoptosis and increased proliferation, suggesting a means by which cells can adapt. Little is known specifically about Nix expression and its importance in human colon cancer. To gain insight into expression of this gene in colon tumors, the present study analyzed mRNA microarray data from 227 colon tumors and 22 normal colon tissue samples and queried differential expression of Nix. These results were compared to the protein levels present in human colon tumors. Methods: mRNA expression of 227 human colon tumors (made available by the Expression Project for Oncology (expO)) and 22 normal colon samples (retrieved from the Gene Expression Omnibus (GEO)) was analyzed. These samples were hybridized to the Affymetrix GeneChip Human Genome U133 Plus 2.0 Array, assaying 17,726 NCBI Entrez genes. Immunohistochemistry was performed on human tissue microarray CO701 (US Biomax, Inc.) containing 62 tumor samples. Results: Nix mRNA levels were shown to increase from normal to cancer (log-fold change of 0.961, Benjamini-Hochberg FDR adjusted p < 0.001). IHC demonstrated variable levels of Nix present in colon tumors: 38/62 (61.3%) of tumors stained positive for Nix while 24/62 (38.7%) were negative. Conclusions: We have shown that mRNA levels of Nix are upregulated in the transition from normal colon tissue to cancer but that protein levels in tumors demonstrate variable expression. This suggests that silencing of Nix occurs at various stages of tumorigenic progression and results in isolated populations of cells within a growing tumor that are uniquely resistant to apoptosis. Better understanding of Nix in the context of a growing colon tumor is needed and could lead to development of more successful therapeutics.

No significant financial relationships to disclose.

False-positive diagnosis of breast cancer by diffused optical tomography with ultrasound

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Background: Breast cancer is one of the most common cancer in women. Early detection, early diagnosis and early treatment play key role in fighting against breast cancer. OPTIMUS system is a system of diffused optical tomography with ultrasound. It provides dual modality images for early diagnosis of breast cancer. The aim of this study was to evaluate the OPTIMUS system on diagnosis of breast disease. Methods: OPTIMUS system was applied to 160 breast tumor patients. All patients had received surgical treatment and had definite pathological diagnosis. OPTIMUS system was evaluated as diagnostic tool of breast tumor in this study. Results: There were 42 cases diagnosed as benign breast disease and 118 cases diagnosed as breast cancer by OPTIMUS system. Pathology confirmed 60 cases of benign disease and 100 cases of breast cancer. False positive rate of breast cancer was 30% (18/60). False negative rate of breast cancer was 0% (0/100). The pathology of false positive cases was mild and severe papillomatosis (6/18), non-typical hyperplasia (4/18), chronic inflammation (3/18), fibroadenoma (3/18) and fat necrosis (2/18). Papillomatosis and non-typical hyperplasia are precancerous lesions and often difficult for clinical diagnosis. In this study the false positive diagnostic rate of mammography and ultrasonography is 13% and 11.1% respectively. Conclusions: OPTIMUS system is a non- invasive and highly effective diagnostic tool for breast disease. Its sensitivity is reached to 100% and specificity is about 70% on the diagnosis of breast cancer. OPTIMUS system could be used as assistant diagnostic tool for breast tumor.

No significant financial relationships to disclose.

Molecular characterisation of outbreak-related strains of vancomycin-resistant Enterococcus faecium from an intensive care unit in Beijing, China

We investigated an outbreak of vancomycin-resistant Enterococcus faecium affecting 14 patients in a 20-bed intensive care unit (ICU) between September 2006 and August 2007 (incidence: 3.56 cases per 1000 ICU patient days). Eighteen isolates of vanA type E. faecium were analysed by pulsed field gel electrophoresis, which showed 14 types overall. Multilocus sequence typing (MLST) identified eight different sequence types (STs) (ST78, ST117, ST203, ST316, ST362, ST363, ST364 and ST365), including four new types (ST362, ST363, ST364 and ST365) and 17 strains belonged to clonal complexes CC17. Sixteen of these carried the esp gene. Eighteen Tn1546-like elements encoding vanA-type VRE were classified into three types (types I to III) and all of them contained both IS1216V and IS1542 insertions. Vancomycin resistance of 14 vanA type E. faecium isolates was transferred at a frequency of 1.3 x 10(-6) to 6.4 x 10(-5) between E. faecium strains during filter mating. Our findings indicate that conjugative dissemination of Tn1546-like elements among CC17 E. faecium occurred during the outbreak in this ICU.

Screening and characterization of monoclonal antibodies to the surface antigens of Listeria monocytogenes serotype 4b

AIMS

This study aims to develop and characterize monoclonal antibodies (Mabs) with high specificity and affinity for surface antigens of an epidemiologically important serotype 4b of Listeria monocytogenes.

METHODS AND RESULTS

Hybridoma clones were derived from B lymphocytes of mice immunized with L. monocytogenes serotype 4b and screened against this strain by an enzyme-linked immunosorbent assay. Twenty-nine clones secreting Mabs reactive with formalin-killed bacteria were obtained; 15, 8, 5 and 1 Mabs were immunoglobulin subclasses IgG2a, IgG2b, IgM and IgG1, respectively. Immunofluorescence or immunogold labelling demonstrated all except five IgM and one IgG2a Mabs bound to the surface of a live L. monocytogenes serotype 4b. The majority of the 23 surface-binding Mabs recognized linear epitopes on a 77-kDa protein. These surface-binding Mabs exhibited little or no cross-reactivity with non-4b serotypes (1/2a, 1/2b, 3a, etc.) of L. monocytogenes, five other Listeria species, Escherichia coli O157:H7 and Salmonella enterica serovar Typhimurium.

CONCLUSIONS

The Mabs recognizing a 77-kDa surface protein are novel antibodies with specificity and affinity for L. monocytogenes serotype 4b.

SIGNIFICANCE AND IMPACT OF THE STUDY

These anti-77 kDa surface protein Mabs may be explored as reagents for the development of Mabs-based diagnostic immunoassays for L. monocytogenes serotype 4b strains.

212 EFFECTS OF VASCULAR ENDOTHELIAL GROWTH FACTOR ON THE EARLY DEVELOPMENT AND POLYSPERMY RATE OF OVINE EMBRYOS PRODUCED IN VITRO

To investigate the effect of vascular endothelial growth factor (VEGF) on the early development and polyspermy rate of ovine embryos in vitro, 2 experiments were conducted with human recombinant VEGF165 supplemented to the media during maturation, fertilization, and culture in vitro, respectively. Ovaries were collected from ewes at a local slaughterhouse. All oocytes surrounded by a multilayer of cumulus cells were collected and rinsed 3 times in maturation medium (control medium and treatment medium, respectively). A total of 100 oocytes in each group were cultured in 4-well plates (Nunc) containing 800 μL of maturation medium at 38.5°C in an atmosphere of 5% CO2 with saturated humidity. Four replicates of each experiment were conducted. Statistical analyses were conducted by ANOVA with SPSS 12.0 software (SPSS Inc., Chicago, IL, USA). Data are expressed as means, and P < 0.05 was considered significant. In Experiment 1, to investigate the effect of VEGF on the early development of ovine embryos in vitro, VEGF was used at 5 ng mL–1 (treatment group A) and 10 ng mL–1 (treatment group B) in maturation medium (TCM-199 + BSA), HSOF fertilization medium, and SOF culture medium. The results showed that the maturation rate was increased significantly (P < 0.01), from 75.76% in the control treatment to 83.98 and 80.23% in treatment group A and treatment group B, respectively. The cleavage rate was increased from 75.85% in the control group to 79.39% in treatment group A (P > 0.05). The development rates of morulae (45.03%) and blastocysts (23.54%) in treatment group A were significantly higher (P < 0.01) than those in the control group (38.94 and 18.09%, respectively). In addition, the development rates of blastocysts in treatment group B (21.05%) were lower than those in treatment group A (P > 0.05) and higher than those in the control group (P > 0.05). In Experiment 2, to investigate the effect of VEGF on the polyspermy rate of ovine embryos in vitro, 5 ng mL–1 of VEGF was used in TCM-199 + BSA maturation medium in this experiment. The results showed that the fertilization rate after 18 h of IVF was increased significantly (P < 0.01), from 75.75% in the control group to 83.86% in the treatment group, and that the polyspermy rate was decreased significantly (P < 0.01), from 12.64% in the control group to 7.68% in the treatment group. These results indicate that VEGF significantly improved the maturation and fertilization rates of ovine oocytes and, consequently, the rate of embryo development in vitro, especially when the medium was supplemented with 5 ng mL–1 of VEGF. The VEGF obviously decreased the polyspermy rate and bated the phenomenon of polyspermy in the process of ovine oocyte IVF. The present study was supported by the National Natural Science Foundation of China (No. 30371035).

Therapeutic effects on experimental metastatic tumor-bearing mice by vaccination with GM-CSF gene-modified and tumor antigen-pulsed macrophages

Macrophages, with potent cytotoxic and antigen-presenting activities, can be used in cancer treatment. The biological characteristics and antitumor effect of GM-CSF gene-modified and tumor antigen-pulsed macrophages were investigated. The high levels of GM-CSF could be detected in the supernatants of macrophages after gene transfer. The cytotoxicity and the expression of MHC class II molecules of the gene-modified macrophages increased significantly and the antigen-presenting ability was enhanced. The gene-modified macrophages were then pulsed with tumor antigen and used to treat the experimental pulmonary metastastic mice. The number of pulmonary metastases was reduced significantly and the cytotoxicity of the CTL induced from the splenocytes of the tumor-bearing mice also increased. The results demonstrated that adenovirus-mediated GM-CSF gene transfer can activate macrophages to some extent and GM-CSF gene-modified, antigen-pulsed macrophages may be a new type of effective effector cells in the immunogene therapy of cancer.

Assessing dietary patterns in Barbados highlights the need for nutritional intervention to reduce risk of chronic disease

BACKGROUND

The dietary habits of the Caribbean have been changing to include more fast foods and a less nutrient dense diet. The aims of this study are to examine dietary patterns in Barbados and highlight foods for a nutritional intervention.

METHODS

Four-day food diaries collected from control participants in the population-based, case-control Barbados National Cancer Study (BNCS).

RESULTS

Forty-nine adult participants (91% response) completed the diaries providing 191 days of dietary data. Total energy intake was almost identical to data collected 5-years earlier in the Barbados Food Consumption and Anthropometric Survey 2000, but the percent energy derived from fat was from 2.1% to 5.2% higher. Sugar intake exceeded the Caribbean recommendation almost four-fold, while intakes of calcium, iron (women only), zinc and dietary fibre were below recommendations. Fish and chicken dishes were the two largest sources of energy and fat. Sweetened drinks and juices provided over 40% of total sugar intake.

CONCLUSIONS

These data provide existing dietary patterns and strongly justify a nutritional intervention program to reduce dietary risk factors for chronic disease. The intervention could focus on the specific foods highlighted, both regarding frequency and amount of consumption. Effectiveness can be evaluated pre- and post-intervention using our Food Frequency Questionnaire developed for BNCS.

Leukocytes of exceptionally old persons display ultra-short telomeres

With a view to understanding the association between leukocyte telomere length and the human lifespan, we performed genome-wide telomere length analyses by the terminal restriction fragment length (TRFL) and single molecule telomere length analysis (STELA) of the X and Y chromosomes in leukocytes of exceptionally old (aged 90–104 yr) and younger (aged 23–74 yr) individuals. We found that the mean TRFL of 82 exceptionally old individuals was within a range projected by age-dependent TRFL attrition of 99 younger individuals. However, compared with the younger individuals, exceptionally old persons exhibited peaking of the TRFL distribution with overrepresentation of ultra-short telomeres. These findings were confirmed by the STELA. Women had longer mean TRFL than men (6.10 vs. 5.86 kb), and exceptionally old women exhibited fewer ultra-short telomeres than exceptionally old men. Our results have implications for gerontological studies of the limitation of lifespan in humans.

Vacuum-ultraviolet Gabor holography with synchrotron radiation

We present the realization of high-resolution holographic microscopy using the original Gabor geometry and imaging with radiation in the vacuum-ultraviolet (VUV) spectral region. Synchrotron VUV radiation with a wavelength of 13.8 nm was focused on a small pinhole generating a highly divergent light cone suitable for digital in-line holography. Objects of different thickness and materials have been used to test the imaging properties of holographic microscopy in the VUV wavelength range. The effective numerical aperture was limited by the illuminated area of the detector, yielding a theoretical resolution below 1 microm and an experimental one of approximately 1 microm.

Magnesium-rich minerals in sediment and suspended particulates of South Florida water bodies: implications for turbidity

Fine sediments in shallow water bodies such as Lake Okeechobee are prone to resuspension. Predominantly inorganic "mud" sediment that covers approximately 670 km2 of the lake has been recognized as a persistent source of turbidity. The objective of this study was to determine if mineral components of sediments in Lake Okeechobee and water conveyances of the northern Everglades also occur as suspended sediment and hence constitute a potential abiotic contributor to turbidity. Sediment samples were collected from nine stations within the lake and eight locations north of Water Conservation Area 2A in the Everglades. Water samples were also collected at selected locations. The silt and clay mineralogy of sediment and suspended particles was determined using X-ray diffraction, thermogravimetry, scanning-electron microscopy, energy-dispersive X-ray elemental microanalysis, and high-resolution transmission-electron microscopy. Clay fractions of the lake sediment contained the Mg silicate minerals sepiolite and palygorskite, along with smectite, dolomite, calcite, and kaolinite. Sediment silt fractions were dominated by carbonates and/or quartz, with smaller amounts of Ca phosphates and sepiolite. Mineralogy of the mud sediment was similar to that reported for geologic phosphate deposits. This suggests that the mud sediment might have accumulated by stream transport of minerals from these deposits. Suspended solids and mud-sediment mineralogy were similar, except that smectite was more abundant in suspended solids. Everglade samples also contained Mg-rich minerals. The small size, low density, and fibrous or platy nature of the prevalent mud sediment minerals make them an abiotic, hydrodynamically sensitive source of persistent turbidity in a shallow lake. Mitigation efforts focused exclusively on P-induced biogeochemical processes do not address the origin or effects of these minerals. Ecological management issues such as turbidity control, P retention, geologic P input, and suitability of dredging are related to mud-sediment properties and provenance.