First-trimester prenatal diagnosis of aspartylglucosaminuria

Fetal aspartylglucosaminuria (AGU) was studied during the first trimester of pregnancy in six at-risk pregnancies using chorionic villus samples. The activity of aspartylglucosaminidase (AGA) was high in five cases, indicating an unaffected fetus. This was confirmed through delivery of healthy newborns with a normal pattern of urinary oligosaccharides. Low enzyme activity in an uncultured biopsy specimen and in cultured amniotic fluid cells in one case demonstrated that the fetus was affected. The pregnancy was terminated and the prenatal diagnosis was confirmed by showing reduced AGA activity in cultured fibroblasts of the fetus.     

Invasive Species Research to Meet the Needs of Resource Management and Planning

Abstract: As zebra mussels (Dreissena polymorpha) continue to spread among inland lakes of the United States and Canada, there is growing interest from professionals, citizens, and other stakeholders to know which lakes are likely to be colonized by zebra mussels. Thus, we developed a classification of lake suitability for zebra mussels on the basis of measured or estimated concentrations of dissolved calcium in lake water and applied the classification to >11,500 lakes in Wisconsin and the Upper Peninsula of Michigan. The majority of lakes (58%) were classified as unsuitable (<10 mg/L Ca) for survival and reproduction of zebra mussels, 27% were identified as suitable (≥21 mg/L Ca), and 15% were classified as borderline suitable (≥10 and <21 mg/L Ca). Of the 77 inland lakes with confirmed zebra mussel records for which data on dissolved calcium were available, our method classified 74 as suitable and 3 as borderline suitable. To communicate this lake‐specific suitability information and to help prioritize regional efforts to monitor and prevent the expansion of zebra mussels and other invasive species, we developed a web‐based interface (available from http://www.aissmartprevention.wisc.edu/ ). Although we are still uncertain of how access to suitability information ultimately affects decision making, we believe this is a useful case study of building communication channels among researchers, practitioners, and the public.     

Monitoring aromatic hydrocarbon biodegradation by functional marker genes

The development of biological treatment technologies for contaminated environments requires tools for obtaining direct information about the biodegradation of specific contaminants. The potential of functional gene array analysis to monitor changes in the amount of functional marker genes as indicators of contaminant biodegradation was investigated. A prototype functional gene array was developed for targeting key functions in the biodegradation of naphthalene, toluene and xylenes. Internal standard probe based normalization was introduced to facilitate comparison across multiple samples. Coupled with one-colour hybridization, the signal normalization improved the consistency among replicate hybridizations resulting in better discrimination for the differences in the amount of target DNA. During the naphthalene biodegradation in a PAH-contaminated soil slurry microcosm, the normalized hybridization signals in naphthalene catabolic gene probes were in good agreement with the amount of naphthalene-degradation genes and the production of 14CO2. Gene arrays provide efficient means for monitoring of contaminant biodegradation in the environment.     

活性污泥中需氧量的研究现状及供氧系统的节能技术

叙述了国内外活性污泥法中需氧量的研究过程及微孔曝气系统的节能技术，对微孔曝气器与穿孔曝管进行对比，证实前者较后者节电４４％．     

Measurement of the biodegradation of starch-based materials by enzymatic methods and composting

The aim of this study was to evaluate the suitability of in vitro enzymatic methods for assaying the biodegradability of new starch-based biopolymers. The materials studied included commercial starch-based materials and thermoplastic starch films prepared by extrusion from glycerol and native potato starch, native barley starch, or crosslinked amylomaize starch. Enzymatic hydrolysis was performed using excessBacillus licheniformis -amylase andAspergillus niger glucoamylase at 37°C and 80°C. The degree of degradation was determined by measuring the dissolved carbohydrates and the weight loss of the samples. Biodegradation was also determined by incubating the samples in a compost environment and measuring the weight loss after composting. The results indicated that the enzymatic method is a rapid means of obtaining preliminary information about the biodegradability of starch-based materials. Other methods are needed to investigate more accurately the extent of biodegradability, especially in the case of complex materials in which starch is blended with other polymers.     

DNA-based prenatal diagnosis of the infantile form of neuronal ceroid lipofuscinosis (INCL,CLN1)

Eleven fetuses at risk for the infantile form of neuronal ceroid lipofuscinosis (INCL, CLN1) were studied using DNA markers and the results were compared with the results of electron microscopy (EM) of chorionic villus specimens from pregnancies in the first or early second trimester of pregnancy. In four cases, the prenatal diagnosis was made independently with both methods, and in seven cases, the EM diagnosis was confirmed postnatally or from autopsy material using RFLP analysis. The two methods gave concordant results in all cases. The DNA analysis based on RFLP haplotypes also for the first time facilitates reliable carrier diagnostics. RFLP analysis based on polymorphic markers closely linked to the INCL locus is now available for prenatal diagnosis of this fatal brain disease, whose biochemical background is totally unknown and for which no treatment is available.     

Stable relatedness structure of the large-colony swarm-founding wasp Polybia paulista

In social-insect colonies, cooperation among nestmates is generally stabilized by their high genetic similarity. Thus, fitness gained through cooperation drops quickly as the number of reproductive females (queens) increases. In this respect, wasps of the tribe Epiponini have attracted special attention, because the colonies have tens, or even hundreds of queens. It has been empirically or genetically confirmed that relatedness within nestmates can be elevated by a mechanism known as cyclical monogyny, under which new queens are produced only after the number of old queens is reduced to one. Another likely factor that can increase relatedness within nestmates under polygyny is comb partitioning by queens. If queens concentrate their egg laying on one or a subset of the available combs, then workers may be able to rear closer relatives by focusing their work on the comb where they emerged. Using microsatellite markers, we tested the hypotheses of cyclical monogyny and comb partitioning by queens increasing relatedness within nestmates under polygyny in the large-colony epiponine wasp, Polybia paulista. There were no significant differences between relatedness within combs and between combs, and thus we ruled out the possibility that each queen partitions reproduction between combs. However, as cyclical monogyny predicts, a lower effective number of queens contributed to queen production than to worker production. Cyclical monogyny explained well the observed smaller effective number of queens for new queens than that for workers, but failed to explain the stable relatedness values throughout colony cycles.Communicated by L. Keller     

Biodegradation of polylactide in aerobic and anaerobic thermophilic conditions

Biodegradable polymers are designed to resist a number of environmental factors during use, but to be biodegradable under disposal conditions. The biodegradation of polylactide (PLLA) was studied at different elevated temperatures in both aerobic and anaerobic, aquatic and solid state conditions. In the aerobic aquatic headspace test the mineralisation of PLLA was very slow at room temperature, but faster under thermophilic conditions. The clear effect of temperature on the biodegradability of PLLA in the aquatic tests indicates that its polymer structure has to be hydrolysed before microorganisms can utilise it as a nutrient source. At similar elevated temperatures, the biodegradation of PLLA was much faster in anaerobic solid state conditions than in aerobic aquatic conditions. The behaviour of PLLA in the natural composting process was similar to that in the aquatic biodegradation tests, biodegradation starting only after the beginning of the thermophilic phase. These results indicate that PLLA can be considered as a compostable material, being stable during use at mesophilic temperatures, but degrading rapidly during waste disposal in compost or anaerobic treatment facilities.     

Trisomy 12 mosaicism in amniocytes and dysmorphic child despite normal chromosomes in fetal blood sample

Trisomy 12 mosaicism (44 per cent) was detected prenatally in cultured amniocytes. A cordocentesis was performed to confirm the result. Only normal cells were found in the fetal blood sample. The fetus was estimated to be at a low risk of having a chromosomal abnormality and the pregnancy continued. Eight days after birth, a congenital heart defect was detected in the child. Several dysmorphic features were also evident. Further karyotyping of different tissues revealed normal blood and urinary cells but trisomic cells in the placenta (100 per cent) and in skin fibroblasts (25 per cent). The child died at 5 weeks of age. In this case, the fetal blood sample failed to reveal the real chromosome constitution of the fetus.     

Uptake of radioiodide by Paenibacillus sp., Pseudomonas sp., Burkholderia sp. and Rhodococcus sp. isolated from a boreal nutrient-poor bog

Radionuclides, like radioiodine(~(129)I), may escape deep geological nuclear waste repositories and migrate to the surface ecosystems. In surface ecosystems, microorganisms can affect their movement. Iodide uptake of six bacterial strains belonging to the genera Paenibacillus,Pseudomonas, Burkholderia and Rhodococcus isolated from an acidic boreal nutrient-poor bog was tested. The tests were run in four different growth media at three temperatures. All bacterial strains removed iodide from the solution with the highest efficiency shown by one of the Paenibacillus strains with 99% of iodide removed from the solution in one of the used growth media. Pseudomonas, Rhodococcus and one of the two Paenibacillus strains showed highest iodide uptake in 1% yeast extract with maximum values for the distribution coefficient(K_d) ranging from 90 to 270 L/kg DW. The Burkholderia strain showed highest uptake in 1% Tryptone(maximum K_d170 L/kg DW). The Paenibacillus strain V0-1-LW showed exceptionally high uptake in 0.5% peptone + 0.25% yeast extract broth(maximum K_d 1,000,000 L/kg DW). Addition of 0.1% glucose to the 0.5% peptone + 0.25% yeast extract broth reduced iodide uptake at 4℃ and 20℃ and enhanced iodide uptake at 37℃ compared to the uptake without glucose. This indicates that the uptake of glucose and iodide may be competing processes in these bacteria. We estimated that in in situ conditions of the bog,the bacterial uptake of iodide accounts for approximately 0.1%–0.3% of the total sorption of iodide in the surface, subsurface peat, gyttja and clay layers.