Analysis of the bacterial community changes in soil for septic tank effluent treatment in response to bio-clogging.

Soil columns were set up to survey the bacterial community in the soil for septic tank effluent treatment. When bio-clogging occurred in the soil columns, the effluent from the columns was in poorer quality. To evaluate changes of the soil bacterial community in response to bio-clogging, the bacterial community was characterized by DNA gene sequences from soil samples after polymerase chain reaction coupled with denaturing gradient gel electrophoresis process. Correspondence analysis showed that Proteobacteria related bacteria were the main bacteria within the soil when treating septic tank effluent. However, Betaproteobacteria related bacteria were the dominant microorganisms in the normal soil, whereas Alphaproteobacteria related bacteria were more abundant in the clogged soil. This study provided insight into changes of the soil bacterial community in response to bio-clogging. The results can supply some useful information for the design and management of soil infiltration systems.

Effects of common dissolved anions on the reduction of para-chloronitrobenzene by zero-valent iron in groundwater.

Batch tests were conducted to evaluate the influences of several common dissolved anions in groundwater on the reduction of para-chloronitrobenzene (p-CNB) by zero-valent iron (ZVI). The results showed that p-CNB reduction was enhanced by both Cl(-) and SO(4)(2-). HCO(3)(-) could either improve or inhibit p-CNB reduction, depending on whether the mixing speed was intense enough to rapidly eliminate Fe-carbonate complex deposited on ZVI surface. Above a concentration of 100 mg L(-1), NO(3)(-) increased the p-CNB reduction rate. The reduction rate by ClO(4)(-) decreased because the ClO(4)(-) competed with p-CNB for electrons. The p-CNB reduction was inhibited by PO(4)(3-), SiO(3)(2-) and humic acid, in the order humic acid < PO(4)(3-) < SiO(3)(2-), since these ions could form inner-sphere complexes on iron surface. The reaction even ceased when the ion concentrations were greater than 4, 0.5, and 30 mg L(-1), respectively. The results indicated that common dissolved anions in groundwater should be taken into account when ZVI is applied for contaminated groundwater remediation.

Effect of soil fortified by polyurethane foam on septic tank effluent treatment.

Fortified soil was made up of a mixture at a mass ratio 4/1000-6/1000 of sponge and natural soil according to the results of column experiment. The fortified soil had bigger porosity and higher hydraulic conductivity than the natural soil. The columns packed with 900 mm of the fortified soil endured a flow rate equivalent to 100 L/m(2)/d of septic tank effluent and the average chemical oxygen demand, nitrogen, and phosphorus removal rates were around 92%, 75% and 96%, respectively. After 100 weeks of operation, the saturated hydraulic conductivity of the fortified soil kept higher than 0.2 m/d. The bigger porosity of sponge improved the effective porosity, and the bigger specific surface area of sponge acted as an ideal support for biomat growth and ensured the sewage treatment performance of the fortified soil. The comparable performance was due to a similar and sufficient degree of soil clogging genesis coupled with bioprocesses that effectively purified the septic tank effluent given the adequate retention times.

Changes in the levels of integrin and focal adhesion kinase (FAK) in human melanoma cells following 532 nm laser treatment.

Despite the increase in laser therapy, concern remains that sublethal treatment of pre-malignant lesions may adversely affect the biological behaviour of surviving cells. Integrin receptors mediate interaction of cells with the extracellular matrix and their occupation leads to focal adhesion kinase (FAK) activation. Using our previously established model we have now investigated subcellular changes and compared integrin and FAK concentrations, the degree of FAK phosphorylation and its association with the beta1 integrin in laser vs. non-laser treated cells. We treated cells with laser generated from a frequency doubled Q-switched (Nd:YAG) laser system (532 nm) at 0.4 J/cm2 twice per week for 4 weeks. Using cell lysates we performed Western immunoblotting 24 hr later to detect integrin subunits and FAK proteins and immunoprecipitation to investigate FAK phosphorylation and its association with beta1. Cell morphology was examined using electron microscopy. SK23 and G361 cells exhibited an 3.4- and 11.2-fold increase, respectively, in FAK protein following laser treatment. FAK phosphorylation in SK23 cells was increased by 82%, whereas FAK phosphorylation in G361 cells was reduced slightly (2%). Furthermore, both alpha3 and 4 integrins were up-regulated, by approximately 4-fold and 7- to 9-fold, respectively. In addition, the beta1 integrin was proteolysed in both cell lines and the levels of FAK associated with beta1 was increased (2.1- and 2.7-fold, respectively). Finally, laser treatment of SK23 cells caused an increased number of cell processes. Sublethal 532 nm laser light thus induces changes in integrin and FAK concentrations and subsequently influences cellular attachment and morphology.

Prognostic significance of allelic losses in primary melanoma.

Loss of genetic material, including loss of loci on chromosome arms 6q, 9p, and 10q, occurs frequently in cutaneous melanoma but infrequently in benign melanocytic nevi or other melanocytic lesions, suggesting that these genetic alterations are important in the development and progression of melanoma. To examine whether allelic loss is of prognostic importance in melanoma, disease-free survival was related to loss of heterozygosity on 6q, 9p and 10q in 83 individuals with sporadic primary cutaneous melanoma. Loss of chromosome arms 6q and 10q were each significantly associated with a poorer clinical outcome (P=0.013 and P=0.001 respectively). In a subgroup of 41 subjects whose primary tumours were allelotyped, the fractional allelic loss (FAL) at 39 autosomal arms also significantly correlated with disease-free survival (P=0.013), with an increase in FAL associated with a poorer outcome; this association remained significant when controlled for tumour thickness (P=0.035). In addition, a greater proportion of cells were immunopositive for Ki67 antigen, p53 and p21WAF1 protein in the primary melanomas than in the benign melanocytic nevi, however, only p53 over-expression was significantly associated with improved survival (P=0.041).

Sub-lethal effects of exposing the human melanoma cell line SKmel-23 to 532 nm laser light.

The human melanoma cell line SKmel-23 has been used to investigate the sub-lethal damage that can occur as a result of exposing melanin containing cells to light (532 nm) from a frequency doubled Q-switched (Nd:YAG) laser. A dose response curve was obtained, which indicates that at energy levels of 0.6 J/cm2 and below no effect on either the viability or growth rate of the cell line was observed. Above this, cells rapidly died and at an energy level of 2.0 J/cm2, only approximately 15% of cells survived. This contrasts with the effects on the G361 melanoma line, which contains far less melanosomes, as an LD50 for this cell line was approximately 5.5 J/cm2. Exposing SKmel-23 cells to 0.4 J/cm2 of 532 nm light results in a diminution of the number of melanosomes within cells as well as a marked decrease in melanin content, as determined by spectrophotometric assay and electron microscopy. Using the reverse transcriptase polymerase chain reaction technique, the reduction in melanin content of the cells was accompanied by a selective decrease in mRNA coding for tyrosinase, the first enzyme in the biosynthetic pathway for melanin. No decrease in the mRNA coding for the GAPDH protein was observed. Our finding has implications for understanding the control processes that regulate the melanin content of cells and suggests that the model described can be used to further investigate changes that may occur in cells as a result of their exposure to sub-lethal levels of laser light.

Lip posture and mouth width in children with unilateral cleft lip.

The aim of this study was to measure on photographs the protrusion of the upper and lower lips and demonstrate their relationships to each other, to measure the width of the mouth, and to compare these findings within complete and incomplete cleft groups and with normal controls at the ages of 5 and 10 years. It was found that the lower lip was more protrusive and the mouth width was narrower in 5-year-old children with complete clefts prior to maxillary collapse than in the control children. It is concluded that there is a lack of tissue in the cleft lip leading to less distensibility and increased lip pressure and that this may be one of the factors causing maxillary retrusion.