Mucolipidosis IV: Prenatal diagnosis by electron microscopy

Mucolipidosis IV (ML 1V) is a lysosomal storage disease presenting in infancy with cloudy cornea and psychomotor retardation. Our experience with 12 pregnancies at risk for ML IV, monitored by transmission electron microscopy (TEM) studies of cultured amniotic fluid cells, is presented. The prenatal diagnoses were confirmed in the 3 affected and the 8 un- affected pregnancies. In the one pregnancy where no definite diagnosis was reached the pregnancy was terminated. TEM examination of fetal tissues from this pregnancy showed no abnormal lysosomal storage bodies and a review of the cultured amniotic fluid cell sections revealed that the diagnosis of a normal fetus could have been made.     

Mitochondrial DNA depletion presenting prenatally with skin edema and multisystem disease immediately after birth

We describe two newborn sisters who presented in the third trimester with diminished fetal movements and skin edema, but with no other signs of hydrops fetalis. Within hours of birth, both developed profound lactic acidemia, followed by multi-organ failure. In muscle mitochondria, the activity of all enzymatic complexes that contain mitochondrial DNA (mtDNA)-encoded subunits was markedly decreased. Southern blot analysis revealed a profound reduction in the mtDNA/nuclear DNA ratio, implying mtDNA depletion. The prenatal identification of skin edema in two patients with mtDNA depletion, and its absence in a healthy sibling, suggest that skin edema should be regarded as a novel manifestation of mtDNA depletion. This finding shows that mtDNA depletion can present prenatally and, consequently, may aid the clinician in making a diagnosis, prenatally, of this genetic defect. Copyright © 2002 John Wiley & Sons, Ltd.     

Impact of microbial activity on the hydraulic properties of fractured chalk

The impact of microbial activity on fractured chalk transmissivity was investigated on a laboratory scale. Long-term experiments were conducted on six fractured chalk cores (20 cm diameter, 23-44 cm long) containing a single natural fracture embedded in a porous matrix. Biodegradation experiments were conducted under various conditions, including several substrate and oxygen concentrations and flow rates. 2,4,6-Tribromophenol (TBP) was used as a model contaminant (substrate). TBP biodegradation efficiency depended mainly on the amount of oxygen. However, under constant oxygen concentration at the core inlet, elevating the flow rates increased the removal rate of TBP. Transmissivity reduction was clearly related to TBP removal rate, following an initial slow decline and a further sharp decrease with time. The fracture's transmissivity was reduced by as much as 97% relative to the initial value, with no leveling off of the clogging process. For the most extreme cases, reductions of 262 and 157 microm in the equivalent hydraulic apertures were recorded for fractures with initial apertures of 495 and 207 microm, respectively. The reductions in fracture transmissivity occurred primarily because of clogging by bacterial cells and extracellular polymeric substances (EPS) produced by the bacteria. Most of the biodegradation activity was concentrated near the fracture inlet, where the most suitable biodegradation conditions (nutrients and oxygen) prevailed, suggesting that the clogging had occurred in that vicinity. The clogging must have changed the structure of the fracture void, thereby reducing the active volume participating in flow and transport processes. This phenomenon caused accelerated transport of non-reactive tracers and doubled the fracture's dispersivity under constant flow rates.     

Cultured amniotic fluid cells for prenatal diagnosis of lysosomal storage disorders: A methodological study

The influence of culture conditions on the ultrastructure and enzyme activities of amniotic fluid cells are reported. Morphological changes were determined as a function of the number of lysosomal-like inclusion bodies per cell, and these results correlated to the activity of Thiexosaminidase, a-mannosidase, β-glucuronidase, arylsulphatase C and 5′ nucleotidase. The parameters examined were pH of the culture media, type of media, increasing cell passage and day of harvest. Our results indicate that enzyme activities are less sensitive to changes in culture conditions as compared to ultrastructural changes. We therefore recommend that in order to obtain reliable ultrastructural results for the diagnosis of storage disorders, cultures should be grown in MEM as the culture medium, the pH of the medium carefully monitored to remain below pH 7·4, examining the cultures no later than the eighth cell passage and no later than the 10th day after subculture.     

Two-dimensional distribution of microbial activity and flow patterns within naturally fractured chalk

The two-dimensional distribution of flow patterns and their dynamic change due to microbial activity were investigated in naturally fractured chalk cores. Long-term biodegradation experiments were conducted in two cores ( approximately 20 cm diameter, 31 and 44 cm long), intersected by a natural fracture. 2,4,6-tribromophenol (TBP) was used as a model contaminant and as the sole carbon source for aerobic microbial activity. The transmissivity of the fractures was continuously reduced due to biomass accumulation in the fracture concurrent with TBP biodegradation. From multi-tracer experiments conducted prior to and following the microbial activity, it was found that biomass accumulation causes redistribution of the preferential flow channels. Zones of slow flow near the fracture inlet were clogged, thus further diverting the flow through zones of fast flow, which were also partially clogged. Quantitative evaluation of biodegradation and bacterial counts supported the results of the multi-tracer tests, indicating that most of the bacterial activity occurs close to the inlet. The changing flow patterns, which control the nutrient supply, resulted in variations in the concentrations of the chemical constituents (TBP, bromide and oxygen), used as indicators of biodegradation.     

Union elections at the local level: the role effectiveness of committee persons

Survey data were collected before and after a local union governance election in which half of the committeeperson incumbents lost. Examination of committeeperson role effectiveness shows that those who lost were rated significantly lower before the election compared to those who were retained. Newcomers who replaced incumbents were rated higher than those they replaced. © 1998 John Wiley & Sons, Ltd.     

Utilization of coal bottom ash to improve thermal insulation of construction material

Journal of Material Cycles and Waste Management - Concerns with sustainable solid waste management and recycling have become increasingly prominent in all sectors of the economy. In light of this,...