Zero-power autonomous buoyancy system controlled by microbial gas production.

A zero-power ballast control system that could be used to float and submerge a device solely using a gas source was built and tested. This system could be used to convey sensors, data loggers, and communication devices necessary for water quality monitoring and other applications by periodically maneuvering up and down a water column. Operational parameters for the system such as duration of the submerged and buoyant states can be varied according to its design.

Enrichment, isolation, and phylogenetic identification of polycyclic aromatic hydrocarbon-degrading bacteria from Elizabeth River sediments.

The diversity of indigenous bacteria in sediments from several sites in the Elizabeth River (Virginia) able to degrade multiple polycyclic aromatic hydrocarbons (PAHs) was investigated by the use of classical selective enrichment and molecular analyses. Enrichment cultures containing naphthalene, phenanthrene, fluoranthene, or pyrene as a sole carbon and energy source were monitored by denaturing gradient gel electrophoresis (DGGE) to detect changes in the bacterial-community profile during enrichment and to determine whether the representative strains present were successfully cultured. The DGGE profiles of the final enrichments grown solely on naphthalene and pyrene showed no clear relationship with the site from which the inoculum was obtained.

Jet-based methods to print living cells.

Cell printing has been popularized over the past few years as a revolutionary advance in tissue engineering has potentially enabled heterogeneous 3-D scaffolds to be built cell-by-cell. This review article summarizes the state-of-the-art cell printing techniques that utilize fluid jetting phenomena to deposit 2- and 3-D patterns of living eukaryotic cells. There are four distinct categories of jetbased approaches to printing cells.

Dissolved oxygen saturation controls PAH biodegradation in freshwater estuary sediments.

Polycyclic aromatic hydrocarbons (PAHs) are common contaminants in terrestrial and aquatic environments and can represent a significant constituent of the carbon pool in coastal sediments. We report here the results of an 18-month seasonal study of PAH biodegradation and heterotrophic bacterial production and their controlling biogeochemical factors from 186 sediment samples taken in a tidally influenced freshwater estuary. For each sampling event, measurements were averaged from 25-45 stations covering approximately 250 km(2).

Biological laser printing of genetically modified Escherichia coli for biosensor applications.

One of the primary requirements of cell- or tissue-based sensors is the placement of cells and cellular material at or near the sensing elements of the device. The ability to achieve precise, reproducible and rapid placement of cells is the focus of this study. We have developed a technique, biological laser printing or BioLP, which satisfies these requirements and has advantages over current technologies.

Laser printing of pluripotent embryonal carcinoma cells.

A technique by which to print patterns and multilayers of scaffolding and living cells could be used in tissue engineering to fabricate tissue constructs with cells, materials, and chemical diversity at the micron scale. We describe here studies using a laser forward transfer technology to print single-layer patterns of pluripotent murine embryonal carcinoma cells. This report focuses on verifying cell viability and functionality as well as the ability to differentiate cells after laser transfer.

Assessment of the aquatic and terrestrial toxicity of five biodegradable polymers.

Radiofrequency countermeasures (i.e., chaff) may be released by fighter jets during tactical countermeasures training.

Radio frequency chaff: the effects of its use in training on the environment.

Chaff is a radiofrequency countermeasure released by military aircraft, ships, and vehicles to confuse enemy radar. Chaff consists of aluminum-coated glass fibers ranging in lengths from 0.8 to 0.

Transport, deposition and biodegradation of particle bound polycyclic aromatic hydrocarbons in a tidal basin of an industrial watershed.

Polycylic aromatic hydrocarbons (PAHs) are common contaminants in industrial watersheds. Their origin, transport and fate are important to scientists, environmental managers and citizens. The Philadelphia Naval Reserve Basin (RB) is a small semi-enclosed embayment near the confluence of the Schuylkill and Delaware Rivers in Pennsylvania (USA).

Generation of mesoscopic patterns of viable Escherichia coli by ambient laser transfer.

We have generated mesoscopic patterns of viable Escherichia coli on Si(1 1 1), glass, and nutrient agar plates by using a novel laser-based transfer process termed matrix assisted pulsed laser evaporation direct write (MAPLE DW). We observe no alterations to the E. coli induced by the laser-material interaction or the shear forces during the transfer.

Reversible cross-linking and CO treatment as an approach in red cell stabilization.

We explored the use of the reversible cross-linking reagent dimethyl 3,3-dithiobispropionimidate (DTBP) in combination with CO treatment as an approach to stabilizing erythrocyte structure and function. Erythrocytes were cross-linked with different concentrations of DTBP for different times. DTBP increased erythrocyte osmotic stability, blocked lysolecithin-induced echinocytosis, and decreased erythrocyte deformability in a concentration- and time-dependent manner.

Etiologies and outcome of acute renal insufficiency in older adults: a renal biopsy study of 259 cases.

Acute renal insufficiency is a common problem, yet one that is frequently reversible with proper diagnosis and treatment. Although it has been argued that a renal biopsy is not needed for diagnosis in most cases of acute renal failure in the elderly, other studies have shown frequent disagreements between clinical and renal biopsy diagnoses in such cases. To investigate the causes of acute renal insufficiency in patients aged at least 60 years who underwent a renal biopsy and possible correlations between biopsy findings and renal survival, we first identified all native renal biopsy specimens from patients aged 60 years or older processed at The University of Chicago Medical Center (Chicago, IL) from 1991 through 1998 and reviewed the clinical records to determine the indication for the biopsy.

Changing etiologies of unexplained adult nephrotic syndrome: a comparison of renal biopsy findings from 1976-1979 and 1995-1997.

Data compiled during the 1970s and early 1980s indicated that during these periods, membranous nephropathy was the most common cause of unexplained nephrotic syndrome in adults, followed in order of frequency by minimal-change nephropathy and focal segmental glomerulosclerosis (FSGS). However, we and others recently reported an increase in the incidence of FSGS over the past two decades, and the number of cases of FSGS diagnosed by renal biopsies in these centers now exceeds the number of cases of membranous nephropathy. Nonetheless, as a substantial fraction of patients with FSGS do not have the nephrotic syndrome, it remained unclear as to what extent the relative frequencies of FSGS and other glomerulopathies as causes of the nephrotic syndrome have changed over this time.

Esophageal carcinoma presenting with nephrotic syndrome: association with anti-neutrophil cytoplasmic antibody.

Malignancy is a cause of membranous glomerulonephritis. We report a patient with an otherwise asymptomatic squamous cell carcinoma of the esophagus whose presenting manifestation was membranous glomerulonephritis and nephrotic syndrome. Perinuclear anti-neutrophil cytoplasmic antibody was positive.

Fabrication of patterned DNA surfaces.

Two photolithographic methods are described for the formation of patterned single or multiple DNA species on SiO2 substrates. In the first approach, substrates are treated with a photochemically labile organosilane monolayer film. Irradiation of these surfaces with patterned deep UV (193 nm) light results in patterned chemically reactive groups which are then reacted with heterobifunctional crosslinking molecules.

The S RNA genomic sequences of Inkoo, San Angelo, Serra do Navio, South River and Tahyna bunyaviruses.

The complete nucleotide sequences of the small (S) genomic RNA segments of five California (CAL) serogroup bunyaviruses (two Inkoo virus strains, San Angelo virus, Serra do Navio virus, South River virus and Tahyna virus) were determined. In agreement with previously published data concerning CAL serogroup viruses, the nucleocapsid (N) and non-structural (NSs) proteins were encoded in over-lapping open reading frames (ORFs). All N protein ORFs were 708 nucleotides in length and encoded a 235 amino-acid gene product.

Treatment of acute glomerular rejection with FK 506.

Acute glomerular rejection is a distinct pathologic subtype of rejection that is often refractory to standard therapy and is associated with significant risk of graft loss. Both cellular and humoral mechanisms have been shown to be involved in the pathophysiology of acute glomerular rejection. FK506, because of its ability to inhibit both cellular and humoral mechanisms of rejection, provides a theoretically attractive approach for treating acute glomerular rejection.

Effects of alkanols, alkanediols and glycerol on red blood cell shape and hemolysis.

The physicochemical effects of a series of alkanols, alkanediols and glycerol on erythrocyte shape and hemolysis at 4 and 20 degrees C were examined. We calculated the dielectric constant of the incubation medium, Ds, and the dielectric constant of the erythrocyte membrane Dm in the presence of organic solutes. The ratio Ds/Dm = -38.

Fabrication and selective surface modification of 3-dimensionally textured biomedical polymers from etched silicon substrates.

A new method is described for producing biomedically relevant polymers with precisely defined micron scale surface texture in the x, y, and z planes. Patterned Si templates were fabricated using photolithography to create a relief pattern in photoresist with lateral dimensions as small as 1 micron. Electroless Ni was selectively deposited in the trenches of the patterned substrate.

Increasing incidence of focal-segmental glomerulosclerosis among adult nephropathies: a 20-year renal biopsy study.

Studies and textbooks from the 1970s and early 1980s list focal-segmental glomerulosclerosis (FSGS) as accounting for 10% to 15% of cases of idiopathic nephrotic syndrome in adults, although a recent review by D'Agati (Kidney Int 46:1223-1241, 1994) reported an approximately sevenfold increase in the incidence of FSGS from 1974 to 1993 in an active renal biopsy practice. To investigate possible changes in the incidence of FSGS in our renal biopsy practice, we reviewed reports from all nontransplant, adult (> or = 18 years) renal biopsies received in our laboratory from 1974 to 1993, which comprised 7,420 cases. All diagnoses of membranous nephropathy (MN), minimal change nephropathy (MCN), and FSGS made in each year were compiled; cases clearly or suspicious of being secondary to an underlying systemic disease, glomerulonephritis, or drug reaction were excluded.

Calcium oxalate monohydrate crystals stimulate gene expression in renal epithelial cells.

Primary or secondary hyperoxaluria is associated with calcium oxalate nephrolithiasis, interstitial fibrosis and progressive renal insufficiency. Monolayer cultures of nontransformed monkey kidney epithelial cells (BSC-1 line) and calcium oxalate monohydrate (COM) crystals were used as a model system to study cell responses to crystal interactions that might occur in the nephrons of patients during periods of hyperoxaluria. To determine if COM crystals signal a change in gene expression, Northern blots were prepared from total renal cellular RNA after the cells were exposed to crystals.

Hereditary sclerosing glomerulopathy in the conorenal syndrome.

Kidney failure is recognized to occur in association with bone malformations, yet the renal disease often is incompletely characterized. In the syndrome of cone-shaped epiphyses of the phalanges and renal failure (conorenal syndrome), the kidney disease has been previously labeled "nephronophthisis" (now termed "medullary cystic disease"). We report two siblings with the conorenal syndrome in whom longitudinal clinical study has been possible and from whom kidney biopsy specimens were obtained prior to renal failure; their renal disease is incompatible with medullary cystic disease.

Controlled release of transforming growth factor-beta from lipid-based microcylinders.

The release of transforming growth factor-beta (TGF-beta) from a lipid microstructure has been demonstrated. Lipid microcylinders, with dimensions of 100 x 0.5 microns and composed of a diacetylenic lipid, have been loaded with 25 ng TGF-beta/mg lipid.