The expression of HER-2/neu (c-erbB2), survivin and cycline D1 in serous ovarian neoplasms: their correlation with clinicopathological variables

Ovarian cancer is the most common cause of death among all gynecologic malignancies and a result of complex interaction of multiple oncogenes and tumor suppressor genes. The aim of this study was to evaluate expression of HER-2/neu (c-erbB2), survivin and cycline D1 biomarkers in serous ovarian neoplasms and their correlations with clinicopathological variables in serous ovarian cancers. We analyzed pathological specimens of 62 patients with benign (n = 25), borderline (n = 14) and malignant (n = 23) serous ovarian neoplasms. Immunohistochemical analysis was performed on formalin-fixed paraffin-embedded specimens. Significantly more immunoreactivity with HER-2/neu was detected in malignant tumors (100 %) compared to borderline (78.6 %) and benign tumors (48 %) (P < 0.01). Survivin expression was significantly higher in malignant tumors (91.3 %) than those found in borderline (71.4 %) and benign tumors (24 %) (P < 0.001). Similarly, higher cyclin D1 expression was observed in malignant tumors (95.6 %) compared to borderline (85.7 %) and benign tumors (48 %) (P < 0.001). Expression of all biomarkers analyzed significantly and gradually increased from benign to borderline and borderline to malignant serous tumors. In terms of clinicopathological variables, only tumor grade was associated with the expression of all biomarkers others exhibited different correlations in serous ovarian cancers. The expressions of HER-2/neu (c-erbB2), survivin and cycline D1 are positively correlated with the malignant potential of serous ovarian neoplasms.     

Phenolic constituents in flax bast tissue and inhibition of cellulase and pectinase

Flax bast tissue was sequentially extracted using hexane, propanol, methanol and water as solvents and extracts were analyzed using reverse phase HPLC and ¹³C NMR. Results indicated a large variety of aromatic constituents including flavonoids and hydroxy-methoxy cinnamic acids linked to oligosaccharides and hydroxy acids through glycosidic linkages. The extracts inhibited cellulase and pectinase activities and can thus influence retting.     

Exploring polyethylenimine-mediated DNA transfection and the proton sponge hypothesis

BACKGROUND: The relatively high transfection efficiency of polyethylenimine (PEI) vectors has been hypothesized to be due to their ability to avoid trafficking to degradative lysosomes. According to the proton sponge hypothesis, the buffering capacity of PEI leads to osmotic swelling and rupture of endosomes, resulting in the release of the vector into the cytoplasm. METHODS: The mechanism of PEI-mediated DNA transfer was investigated using quantitative methods to study individual steps in the overall transfection process. In addition to transfection efficiency, the cellular uptake, local pH environment, and stability of vectors were analyzed. N-Quaternized (and therefore non-proton sponge) versions of PEI and specific cell function inhibitors were used to further probe the proton sponge hypothesis. RESULTS: Both N-quaternization and the use of bafilomycin A1 (a vacuolar proton pump inhibitor) reduced the transfection efficiency of PEI by approximately two orders of magnitude. Chloroquine, which buffers lysosomes, enhanced the transfection efficiency of N-quaternized PEIs and polylysine by 2-3-fold. In contrast, chloroquine did not improve the transfection efficiency of PEI. The measured average pH environment of PEI vectors was 6.1, indicating that they successfully avoid trafficking to acidic lysosomes. Significantly lower average pH environments were observed for permethyl-PEI (pH 5.4), perethyl-PEI (pH 5.1), and polylysine (pH 4.6) vectors. Cellular uptake levels of permethyl-PEI and perethyl-PEI vectors were found to be 20 and 90% higher, respectively, than that of parent PEI vectors, indicating that the reduction in transfection activity of the N-quaternized PEIs is due to a barrier downstream of cellular uptake. A polycation/DNA-binding affinity assessment showed that the more charge dense N-quaternized PEIs bind DNA less tightly than PEI, demonstrating that poor vector unpackaging was not responsible for the reduced transfection activity of the N-quaternized PEIs. CONCLUSIONS: The results obtained are consistent with the proton sponge hypothesis and strongly suggest that the transfection activity of PEI vectors is due to their unique ability to avoid acidic lysosomes.     

Rumen fungi: morphological types from Georgia cattle and the attack on forage cell walls

Fungal colonies developing in anaerobic media from zoospores in rumen fluid from cows eating Cynodon dactylon or Medicago sativa included types showing monocentric and polycentric growth. High energy supplements added to diets of Sorghum bicolor silage increased fungal numbers in the rumen, but increases were also affected by the history and predisposition of the animal. Mixed fungal types in rumen fluid and pure cultures of isolates showing monocentric and polycentric growth degraded and weakened lignocellulosic tissues and penetrated the cuticle of C. dactylon leaf blades. By weakening or degrading recalcitrant structures in forages, rumen fungi may alter physical parameters of plants that influence utilization of fibre by ruminants.     

Degradation of polysaccharides and lignin by ruminal bacteria and fungi.

Bermudagrass (Cynodon dactylon) leaf blades and whole cordgrass (Spartina alterniflora) fiber were evaluated for degradation of cell walls by microbial groups in ruminal fluid. The groups were selected by the addition of antibiotics to the inoculum as follows: (i) whole ruminal fluid (WRF), no antibiotics; (ii) cycloheximide (C) to inhibit fungi, thus showing potential bacterial activity; (iii) streptomycin and penicillin (S,P) to inhibit fiber-degrading bacteria, showing potential fungal activity; (iv) streptomycin, penicillin, and chloramphenicol (S,P,CAM) to inhibit all bacteria including methanogens; (v) streptomycin, penicillin, and cycloheximide (S,P,C) to inhibit all microbial activity as a control; and (vi) autoclaved ruminal fluid (ARF) to inhibit all biological activity as a second control. Scanning electron microscopy of tissue degradation indicated that tissues not giving a positive histological reaction for lignin were more readily degraded. Cordgrass was more highly lignified, with more tissues resisting degradation than in bermudagrass. Patterns of degradation due to treatment resulted in three distinct groups of data based on the extent of fiber or component losses: WRF and C greater than S,P and S,P,CAM greater than S,P,C and ARF. Therefore, bacterial activity was responsible for most of the fiber loss. Fiber degradation by anaerobic fungi was significantly less (P = 0.05). Cupric oxide oxidation of undigested and digested bermudagrass fiber indicated that phenolic constituents differed in their order of resistance to removal or solubilization. Vanillyl and syringyl components of lignin were the most resistant to decomposition, whereas ferulic acid was readily solubilized from fiber in the absence of microbial activity.(ABSTRACT TRUNCATED AT 250 WORDS)     

Biological degradation of tannins in sericea lespedeza (Lespedeza cuneata) by the white rot fungi Ceriporiopsis subvermispora and Cyathus stercoreus analyzed by solid-state 13C nuclear magnetic resonance spectroscopy.

Leaves of sericea lespedeza exhibit a high proportion of condensed tannin, resulting in poor forage quality. The white rot fungi Ceriporiopsis subvermispora and Cyathus sterocoreus are known to preferentially degrade lignin in a variety of plants and were evaluated for their ability to degrade condensed tannin from sericea leaves with the aim of improving digestibility. Relative levels of condensed tannin, cutin, pectin, and cellulose were monitored as a function of fungal treatment by solid-state cross-polarization and magic angle spinning 13C nuclear magnetic resonance spectroscopy. Total soluble phenolics, soluble tannins, and soluble and insoluble proanthocyanidin levels in fungus-treated and control samples were measured by established chemical techniques. Results indicate that both species of fungus preferentially degrade condensed tannin and that C. subvermispora is markedly superior to C. stercoreus in this capacity.     

Identification and Retting Efficiencies of Fungi Isolated from Dew-Retted Flax in the United States and Europe

Seven strains of filamentous fungi and one yeast were isolated from flax that was dew retted in the United States. These filamentous fungi were subcultured to purity and identified, and six appear not to have been reported earlier as isolates from dew-retted flax. Five of the purified U.S. strains, two fungi isolated from flax that was dew retted in Europe, and a laboratory culture of Aspergillus sojae were tested for their ability to ret flax stems. The monocultures were evaluated for the degree of retting, fiber strength, dry weight loss, and tactile response (i.e., feel of softness) as reflected in the retted fiber. Structural modifications of representative samples of the retted flax were assessed by scanning electron microscopy. All of the filamentous fungi were able to carry out some retting, whereas the isolated yeast could not. All organisms produced pectinases when they were cultivated in shake flasks on ball-milled flax as the sole carbon source. Some fungi also produced cellulases, mannanases, and xylanases. Rhizomucor pusillus and Fusarium lateritium were noteworthy as retting organisms by their high level of pectinase activity, ability to attack noncellulosic cell types without attacking cellulose, capacity to penetrate the cuticular surface of the stem, and efficient fiber release from the core. The results indicated that these organisms deserve further study as potential organisms for retting of bast fibers in industrial applications.     

Increased serum copper and decreased serum zinc levels in children with iron deficiency anemia

In order to evaluate serum copper and zinc status in children with iron deficiency anemia (IDA), 60 children with IDA aged 1–14 yr and 64 healthy children as controls aged 1–14 yr were included the study. Serum copper levels were higher in children with IDA (189 ± 49 (Μg/dL) than those of controls (163 ± 37 Μg/dL) (p = 0.001). Serum zinc levels were lower in the patient group (109 ± 59 Μg/dL) than those of control subjects (135 ± 56 Μg/dL) (p = 0.017). In addition, there were statistically significant negative correlations between hematological parameters and serum copper levels in the patient group, but not in controls. No correlation between hematological parameters and serum zinc levels were found in both patient and control groups, except positive correlation between mean corpuscular volume (MCV) and serum zinc level in patients. It was concluded that at the time of managing children with IDA, zinc deficiency must be borne in mind and if necessary treatment should be initiated with zinc.     

Rumen bacterial interrelationships with plant tissue during degradation revealed by transmission electron microscopy

The mode of rumen bacterial degradation of cell walls in coastal bermudagrass [Cynodon dactylon (L) Pers.] differed with the plant tissue type. Bacteria degraded thin, primary cell walls of mesophyll and phloem apparently by extracellular enzymes and without prior attachment; thick-walled bundle sheath and epidermal cells apparently were degraded after bacterial attachment, in some types by an extracellular substance, to the plant cell walls. Rumen bacteria split the nondegraded cuticle from the epidermis by preferentially attacking the cell just underneath the cuticle. The propensity for bacterial attachment to lignified cells of the vascular tissue was low, and bacterial degradation of these cells did not occur after 72 h of incubation.