Environmental Toxicity of Driving Distance to External Beam Radiotherapy (EBRT) for Head and Neck Cancer Patients

PURPOSE/OBJECTIVE(S)

For many patients undergoing external beam radiotherapy (EBRT), distance from home to treatment center is significant and require housing in closer proximity to minimize this travel burden. Patient transport also contributes significantly to the carbon footprint of EBRT. We sought to define the difference of carbon dioxide (CO2) emissions from commuting for patients who stay at a charity housing (CH) facility during treatment for head and neck cancer (HNC) versus a commute from home.

MATERIALS/METHODS

Patients with HNC were enrolled in an IRB-approved prospective protocol from 2019-2021. A distance of 3 miles (mi) was calculated from CH to our facility using Google Maps. Driving distance from home was indicated by patient self-report. Distance traveled per day Mon-Fri was doubled to account for driving to and from treatment. It was assumed that patients staying at CH returned home on weekends and that all used a standard, gasoline powered automobile for transportation to and from home. Transportation from CH to treatment was via a gasoline powered, 6-person shuttle. Both forms of transport were considered light-duty vehicles (LDV) with mileage and tailpipe emissions corresponding to the US on-road average (23.7 mi per gallon and 0.84 lb CO2/mi). For estimation of CH emissions, conversions were made from the reported electricity bill multiplied by the North Carolina grid emissions rate of 0.698 lb CO2/kWh. Natural gas used by CH for heating (prorated per patient) was estimated using the Piedmont Natural Gas rate (located in NC) and the monthly gas bill. Emissions from patient homes were assumed to be similar for patients commuting and making use of CH and therefore ignored.

RESULTS

Forty-nine patients enrolled in the study: 38 drove themselves to treatment daily, and 2 stayed at CH. The remaining 9 patients indicated that they stayed with friends/family or in a hotel where travel distance to DCI was unknown. CH electricity emissions were estimated to be 8,823 lb CO2/month. CH gas emissions were estimated to be 2,210.6 lb CO2/month. Emissions at CH were calculated as 137.9 lb CO2 per patient per month. The median emissions of those who drove daily per course of EBRT was 1205.4 lb CO2 (IQR 366.0 - 2221.2). For the 2 patients who stayed at the CH, total mi per course were 650 and 774. Including emissions of CH, emissions per patient were 1305.6 and 1523.2 lb CO2. If these patients were to have driven daily from their home, emissions would have been doubled (2368.8 and 2646 lb CO2, respectively). CH was estimated to result in fewer emissions for those that live ≥ 12 miles from the treatment facility.

CONCLUSION

Affordable and safe housing, such as charity housing is not only convenient for patients, but also reduces the environmental impact of travel for care for HNC. Patients who stayed at the charity housing in this study reduced their emissions from travel by nearly a half compared to driving daily in a personal vehicle. Further studies are imperative to continue to measure and mitigate the environmental toxicity of cancer care.

How and why we need to capture tacit knowledge in manufacturing: Case studies of visual inspection

Human visual inspection skills remain superior for ensuring product quality and conformance to standards in the manufacturing industry. However, at present these skills cannot be formally shared with other workers or used to develop and implement new solutions or assistive technologies because they involve a high level of tacit knowledge which only exists in skilled operators' internal cognitions. Industry needs reliable methods for the capture and analysis of this tacit knowledge so that it can be shared and not lost but also so that it can be best utilised in the transfer of manual work to automated systems and introduction of new technologies and processes. This paper describes two UK manufacturing case studies that applied systematic task analysis methods to capture and scrutinise the tacit knowledge and skills being applied in the visual inspection of aerospace components. Results reveal that the method was effective in eliciting tacit knowledge, and showed that tacit skills are particularly needed when visual inspection standards lack specification or the task requires greater subjective interpretation. The implications of these findings for future research and for developments in the manufacturing industry are discussed.

C-terminal processing of GlyGly-CTERM containing proteins by rhombosortase in Vibrio cholerae

Vibrio cholerae and a subset of other Gram-negative bacteria, including Acinetobacter baumannii, express proteins with a C-terminal tripartite domain called GlyGly-CTERM, which consists of a motif rich in glycines and serines, followed by a hydrophobic region and positively charged residues. Here we show that VesB, a V. cholerae serine protease, requires the GlyGly-CTERM domain, the intramembrane rhomboid-like protease rhombosortase, and the type II secretion system (T2SS) for localization at the cell surface. VesB is cleaved by rhombosortase to expose the second glycine residue of the GlyGly-CTERM motif, which is then conjugated to a glycerophosphoethanolamine-containing moiety prior to engagement with the T2SS and outer membrane translocation. In support of this, VesB accumulates intracellularly in the absence of the T2SS, and surface-associated VesB activity is no longer detected when the rhombosortase gene is inactivated. In turn, when VesB is expressed without an intact GlyGly-CTERM domain, VesB is released to the extracellular milieu by the T2SS and does not accumulate on the cell surface. Collectively, our findings suggest that the posttranslational modification of the GlyGly-CTERM domain is essential for cell surface localization of VesB and other proteins expressed with this tripartite extension.

Enhancing Community Education Through Innovative Teaching Strategies in a Baccalaureate Nursing Program

BACKGROUND

Nurse educators are relentlessly in search of innovative measures that enhance student learning and offer opportunities that prepare them for clinical practice. Collaborative opportunities between schools of nursing and community settings are beneficial for students and the community.

METHOD

One strategy was developed by a southeastern baccalaureate nursing program through the assistance of the National Institutes of Health mini-grants program, related to their Safe Sleep campaign. Safe Sleep subject matter was integrated into the curriculum, where students learned content, developed teaching strategies, and taught community members components of Safe Sleep.

RESULTS

The project provided faculty and baccalaureate nursing students with an opportunity to implement a community outreach education project addressing Safe Sleep. Students learned cultural assessment, teaching, and communication skills, and community members benefited from learned knowledge of health promotion programs.

CONCLUSION

Future educational outreach projects are recommended to further examine program effectiveness and the value of teaching-learning strategies. [J Nurs Educ. 2018;57(4):240-244.].

Targeting the Type II Secretion System: Development, Optimization, and Validation of a High-Throughput Screen for the Identification of Small Molecule Inhibitors

Nosocomial pathogens that develop multidrug resistance present an increasing problem for healthcare facilities. Due to its rapid rise in antibiotic resistance, Acinetobacter baumannii is one of the most concerning gram-negative species. A. baumannii typically infects immune compromised individuals resulting in a variety of outcomes, including pneumonia and bacteremia. Using a murine model for bacteremia, we have previously shown that the type II secretion system (T2SS) contributes to in vivo fitness of A. baumannii. Here, we provide support for a role of the T2SS in protecting A. baumannii from human complement as deletion of the T2SS gene gspD resulted in a 100-fold reduction in surviving cells when incubated with human serum. This effect was abrogated in the absence of Factor B, a component of the alternative pathway of complement activation, indicating that the T2SS protects A. baumannii against the alternative complement pathway. Because inactivation of the T2SS results in loss of secretion of multiple enzymes, reduced in vivo fitness, and increased sensitivity to human complement, the T2SS may be a suitable target for therapeutic intervention. Accordingly, we developed and optimized a whole-cell high-throughput screening (HTS) assay based on secreted lipase activity to identify small molecule inhibitors of the T2SS. We tested the reproducibility of our assay using a 6,400-compound library. With small variation within controls and a dynamic range between positive and negative controls, the assay had a z-factor of 0.65, establishing its suitability for HTS. Our screen identified the lipase inhibitors Orlistat and Ebelactone B demonstrating the specificity of the assay. To eliminate inhibitors of lipase activity and lipase expression, two counter assays were developed and optimized. By implementing these assays, all seven tricyclic antidepressants present in the library were found to be inhibitors of the lipase, highlighting the potential of identifying alternative targets for approved pharmaceuticals. Although no T2SS inhibitor was identified among the compounds that reduced lipase activity by ≥30%, our small proof-of-concept pilot study indicates that the HTS regimen is simple, reproducible, and specific and that it can be used to screen larger libraries for the identification of T2SS inhibitors that may be developed into novel A. baumannii therapeutics.

Habitat Suitability Model for the Distribution of Ixodes scapularis (Acari: Ixodidae) in Minnesota

Ixodes scapularis Say, the black-legged tick, is the primary vector in the eastern United States of several pathogens causing human diseases including Lyme disease, anaplasmosis, and babesiosis. Over the past two decades, I. scapularis-borne diseases have increased in incidence as well as geographic distribution. Lyme disease exists in two major foci in the United States, one encompassing northeastern states and the other in the Upper Midwest. Minnesota represents a state with an appreciable increase in counties reporting I. scapularis-borne illnesses, suggesting geographic expansion of vector populations in recent years. Recent tick distribution records support this assumption. Here, we used those records to create a fine resolution, subcounty-level distribution model for I. scapularis using variable response curves in addition to tests of variable importance. The model identified 19% of Minnesota as potentially suitable for establishment of the tick and indicated with high accuracy (AUC = 0.863) that the distribution is driven by land cover type, summer precipitation, maximum summer temperatures, and annual temperature variation. We provide updated records of established populations near the northwestern species range limit and present a model that increases our understanding of the potential distribution of I. scapularis in Minnesota.

Outer Membrane Vesicle-Mediated Export of Processed PrtV Protease from Vibrio cholerae

Background

Outer membrane vesicles (OMVs) are known to release from almost all Gram-negative bacteria during normal growth. OMVs carry different biologically active toxins and enzymes into the surrounding environment. We suggest that OMVs may therefore be able to transport bacterial proteases into the target host cells. We present here an analysis of the Vibrio cholerae OMV-associated protease PrtV.

Methodology/Principal Findings

In this study, we demonstrated that PrtV was secreted from the wild type V. cholerae strain C6706 via the type II secretion system in association with OMVs. By immunoblotting and electron microscopic analysis using immunogold labeling, the association of PrtV with OMVs was examined. We demonstrated that OMV-associated PrtV was biologically active by showing altered morphology and detachment of cells when the human ileocecum carcinoma (HCT8) cells were treated with OMVs from the wild type V. cholerae strain C6706 whereas cells treated with OMVs from the prtV isogenic mutant showed no morphological changes. Furthermore, OMV-associated PrtV protease showed a contribution to bacterial resistance towards the antimicrobial peptide LL-37.

Conclusion/Significance

Our findings suggest that OMVs released from V. cholerae can deliver a processed, biologically active form of PrtV that contributes to bacterial interactions with target host cells.

Fluorescence microscopy and proteomics to investigate subcellular localization, assembly, and function of the type II secretion system

Investigation of secretion systems is often critical to understanding the virulence mechanisms of bacterial pathogens. With estimates as high as 30-40% of proteins secreted or localized to the cell envelope, information about the subcellular localization and organization of secretion complexes and identification and functional characterization of their substrates are key steps toward understanding these intricate systems. Here we describe a protocol using fluorescent live-cell imaging of fusion proteins that can provide a powerful tool to potentially examine the localization, assembly, and role of each component in the secretion complex. In addition, we describe protocols for the identification of secreted substrates using 1D SDS-PAGE coupled with nano-liquid chromatography (LC) and tandem mass spectrometry (MS/MS), and isobaric tagging for absolute quantification (iTRAQ) coupled with two-dimensional LC and MS/MS. Both experimental approaches are applicable to any similar study of membrane transport systems.

A proteomic analysis of the effect of growth hormone on mammary alveolar cell-T (MAC-T) cells in the presence of lactogenic hormones

The bovine mammary alveolar cell-T (MAC-T) cell line is able to uniformly differentiate and secrete casein proteins in response to dexamethasone, insulin, and prolactin and is extensively used to study bovine mammary epithelial cell (MEC) function. Somatotropin, or growth hormone (GH), has been shown to increase milk protein synthesis both in vivo and in mammary cell models and to induce cytoskeletal rearrangement in a 3T3 fibroblast cell line and a Chinese hamster ovary cell line. To identify the nature of the effects of GH in MECs cultured with lactogenic hormones, changes in global protein expression were assessed in the MAC-T cell line with the use of two-dimensional gel electrophoresis and matrix-assisted laser desorption ionization tandem time of flight mass spectrometry. Forty proteins were differentially expressed in response to GH (P < 0.05) and were related to metabolism, the cytoskeleton, protein folding, RNA and DNA processing, and oxidant stress. These widespread changes in protein expression are indicative of a global role of GH in overall cellular differentiation that may underlie the direct modulation of milk component synthesis in MEC models that have been described to date.

Structural and functional studies on the interaction of GspC and GspD in the type II secretion system

Type II secretion systems (T2SSs) are critical for secretion of many proteins from Gram-negative bacteria. In the T2SS, the outer membrane secretin GspD forms a multimeric pore for translocation of secreted proteins. GspD and the inner membrane protein GspC interact with each other via periplasmic domains. Three different crystal structures of the homology region domain of GspC (GspC^HR) in complex with either two or three domains of the N-terminal region of GspD from enterotoxigenic Escherichia coli show that GspC^HR adopts an all-β topology. N-terminal β-strands of GspC and the N0 domain of GspD are major components of the interface between these inner and outer membrane proteins from the T2SS. The biological relevance of the observed GspC–GspD interface is shown by analysis of variant proteins in two-hybrid studies and by the effect of mutations in homologous genes on extracellular secretion and subcellular distribution of GspC in Vibrio cholerae. Substitutions of interface residues of GspD have a dramatic effect on the focal distribution of GspC in V. cholerae. These studies indicate that the GspC^HR–GspD^N0 interactions observed in the crystal structure are essential for T2SS function. Possible implications of our structures for the stoichiometry of the T2SS and exoprotein secretion are discussed.

Many bacterial pathogens affecting humans, animals and plants export diverse proteins across the cell membranes into the medium surrounding the bacteria. Some of these secreted proteins are involved in pathogenesis. One example is cholera toxin secreted by the bacterium Vibrio cholerae, a causative agent of cholera. The sophisticated type II secretion system is responsible for moving this toxin, and several other proteins, across the outer membrane. Here, we studied the interaction between the outer membrane pore of the type II secretion system, the secretin GspD, and the inner membrane protein GspC. We have solved three crystal structures of complexes between the interacting domains and identified critical contacts in the GspC–GspD interface. We also showed the importance of these contacts for assembly of the secretion system and for secretion of proteins by V. cholerae. Our studies provide a major piece in the puzzle of how the type II secretion system is assembled and how it functions. One day this knowledge might allow us to design compounds which interfere with this secretion process. Such compounds would be useful in the battle against bacteria affecting human health.

Long helical filaments are not seen encircling cells in electron cryotomograms of rod-shaped bacteria

How rod-shaped bacteria form and maintain their shape is an important question in bacterial cell biology. Results from fluorescent light microscopy have led many to believe that the actin homolog MreB and a number of other proteins form long helical filaments along the inner membrane of the cell. Here we show using electron cryotomography of six different rod-shaped bacterial species, at macromolecular resolution, that no long (> 80 nm) helical filaments exist near or along either surface of the inner membrane. We also use correlated cryo-fluorescent light microscopy (cryo-fLM) and electron cryo-tomography (ECT) to identify cytoplasmic bundles of MreB, showing that MreB filaments are detectable by ECT. In light of these results, the structure and function of MreB must be reconsidered: instead of acting as a large, rigid scaffold that localizes cell-wall synthetic machinery, moving MreB complexes may apply tension to growing peptidoglycan strands to ensure their orderly, linear insertion.

The three-dimensional structure of the cytoplasmic domains of EpsF from the type 2 secretion system of Vibrio cholerae

The type 2 secretion system (T2SS), a multi-protein machinery that spans both the inner and the outer membranes of Gram-negative bacteria, is used for the secretion of several critically important proteins across the outer membrane. Here we report the crystal structure of the N-terminal cytoplasmic domain of EpsF, an inner membrane spanning T2SS protein from Vibrio cholerae. This domain consists of a bundle of six anti-parallel helices and adopts a fold that has not been described before. The long C-terminal helix alpha6 protrudes from the body of the domain and most likely continues as the first transmembrane helix of EpsF. Two N-terminal EpsF domains form a tight dimer with a conserved interface, suggesting that the observed dimer occurs in the T2SS of many bacteria. Two calcium binding sites are present in the dimer interface with ligands provided for each site by both subunits. Based on this new structure, sequence comparisons of EpsF homologs and localization studies of GFP fused with EpsF, we propose that the second cytoplasmic domain of EpsF adopts a similar fold as the first cytoplasmic domain and that full-length EpsF, and its T2SS homologs, have a three-transmembrane helix topology.

Synergistic stimulation of EpsE ATP hydrolysis by EpsL and acidic phospholipids

EpsE is a cytoplasmic component of the type II secretion system in Vibrio cholerae. Through ATP hydrolysis and an interaction with the cytoplasmic membrane protein EpsL, EpsE supports secretion of cholera toxin across the outer membrane. In this study, we have determined the effect of the cytoplasmic domain of EpsL (cyto-EpsL) and purified phospholipids on the ATPase activity of EpsE. Acidic phospholipids, specifically cardiolipin, bound the copurified EpsE/cyto-EpsL complex and stimulated its ATPase activity 30-130-fold, whereas the activity of EpsE alone was unaffected. Removal of the last 11 residues (residues 243-253) from cyto-EpsL prevented cardiolipin binding as well as stimulation of the ATPase activity of EpsE. Further mutagenesis of the C-terminal region of the EpsL cytoplasmic domain adjacent to the predicted transmembrane helix suggested that this region participates in fine tuning the interaction of EpsE with the cytoplasmic membrane and influences the oligomerization state of EpsE thereby stimulating its ATPase activity and promoting extracellular secretion in V. cholerae.

Type II secretion: from structure to function

Gram-negative bacteria use the type II secretion system to transport a large number of secreted proteins from the periplasmic space into the extracellular environment. Many of the secreted proteins are major virulence factors in plants and animals. The components of the type II secretion system are located in both the inner and outer membranes where they assemble into a multi-protein, cell-envelope spanning, complex. This review discusses recent progress, particularly newly published structures obtained by X-ray crystallography and electron microscopy that have increased our understanding of how the type II secretion apparatus functions and the role that individual proteins play in this complex system.

Fixed film phosphorus removal--flexible enough?

While biological phosphorus removal (BPR) has been practised for 30 years, up to recently it has been restricted mainly to activated sludge processes, with the corresponding need for large basin volumes. Yet, research with biofilm reactors showed that the principle of alternate anaerobic and aerated conditions was applicable to fixed bacteria by changing the conditions in time rather than in space. Attached growth enhanced biological phosphorus removal (EBPR) systems are attractive because of their compactness and capability to retain high biomass levels. However, the phosphorus extraction depends on backwashes to enhance the phosphorus-rich attached biomass, and correct control of unsteady effluent quality created by frequently modified process conditions. Accordingly, EBPR remains a challenging task in terms of combining nitrogen and phosphorus removal using attached growth systems. Nevertheless, a combination of activated sludge and biofilm carriers, in the integrated fixed-film activated sludge system, provides treatment opportunities not readily available using suspended growth systems. Current practice is only at the beginning of exploiting the full potential of this combination, but the first full-scale results show that compact tankage and low nutrient results based on biological principles are possible.

Characterization and Metabolic Function of a Peroxisomal Sarcosine and Pipecolate Oxidase from Arabidopsis

Sarcosine oxidase (SOX) is known as a peroxisomal enzyme in mammals and as a sarcosine-inducible enzyme in soil bacteria. Its presence in plants was unsuspected until the Arabidopsis genome was found to encode a protein (AtSOX) with approximately 33% sequence identity to mammalian and bacterial SOXs. When overexpressed in Escherichia coli, AtSOX enhanced growth on sarcosine as sole nitrogen source, showing that it has SOX activity in vivo, and the recombinant protein catalyzed the oxidation of sarcosine to glycine, formaldehyde, and H(2) O(2) in vitro. AtSOX also attacked other N-methyl amino acids and, like mammalian SOXs, catalyzed the oxidation of l-pipecolate to Delta(1)-piperideine-6-carboxylate. Like bacterial monomeric SOXs, AtSOX was active as a monomer, contained FAD covalently bound to a cysteine residue near the C terminus, and was not stimulated by tetrahydrofolate. Although AtSOX lacks a typical peroxisome-targeting signal, in vitro assays established that it is imported into peroxisomes. Quantitation of mRNA showed that AtSOX is expressed at a low level throughout the plant and is not sarcosine-inducible. Consistent with a low level of AtSOX expression, Arabidopsis plantlets slowly metabolized supplied [(14)C]sarcosine to glycine and serine. Gas chromatography-mass spectrometry analysis revealed low levels of pipecolate but almost no sarcosine in wild type Arabidopsis and showed that pipecolate but not sarcosine accumulated 6-fold when AtSOX expression was suppressed by RNA interference. Moreover, the pipecolate catabolite alpha-aminoadipate decreased 30-fold in RNA interference plants. These data indicate that pipecolate is the endogenous substrate for SOX in plants and that plants can utilize exogenous sarcosine opportunistically, sarcosine being a common soil metabolite.

Import of the peroxisomal targeting signal type 2 protein 3-ketoacyl-coenzyme a thiolase into glyoxysomes

Most peroxisomal matrix proteins possess a carboxy-terminal tripeptide targeting signal, termed peroxisomal targeting signal type 1 (PTS1), and follow a relatively well-characterized pathway of import into the organelle. The peroxisomal targeting signal type 2 (PTS2) pathway of peroxisomal matrix protein import is less well understood. In this study, we investigated the mechanisms of PTS2 protein binding and import using an optimized in vitro assay to reconstitute the transport events. The import of the PTS2 protein thiolase differed from PTS1 protein import in several ways. Thiolase import was slower than typical PTS1 protein import. Competition experiments with both PTS1 and PTS2 proteins revealed that PTS2 protein import was inhibited by addition of excess PTS2 protein, but it was enhanced by the addition of PTS1 proteins. Mature thiolase alone, lacking the PTS2 signal, was not imported into peroxisomes, confirming that the PTS2 signal is necessary for thiolase import. In competition experiments, mature thiolase did not affect the import of a PTS1 protein, but it did decrease the amount of radiolabeled full-length thiolase that was imported. This is consistent with a mechanism by which the mature protein competes with the full-length thiolase during assembly of an import complex at the surface of the membrane. Finally, the addition of zinc to PTS2 protein imports increased the level of thiolase bound and imported into the organelles.

GDF-5 deficiency in mice leads to disruption of tail tendon form and function

Although the biological factors which regulate tendon homeostasis are poorly understood, recent evidence suggests that Growth and Differentiation Factor-5 (GDF-5) may play a role in this important process. The purpose of this study was to investigate the effect of GDF-5 deficiency on mouse tail tendon using the brachypodism mouse model. We hypothesized that GDF-5 deficient tail tendon would exhibit altered composition, ultrastructure, and biomechanical behavior when compared to heterozygous control littermates. Mutant tail tendons did not display any compositional differences in sulfated glycosaminoglycans (GAG/DNA), collagen (hydroxyproline/DNA), or levels of fibromodulin, decorin, or lumican. However, GDF-5 deficiency did result in a 17% increase in the proportion of medium diameter (100-225 nm) collagen fibrils in tail tendon (at the expense of larger fibrils) when compared to controls (p < 0.05). Also, mutants exhibited a trend toward an increase in irregularly-shaped polymorphic fibrils (33% more, p > 0.05). While GDF-5 deficient tendon fascicles did not demonstrate any significant differences in quasistatic biomechanical properties, mutant fascicles relaxed 11% more slowly than control tendons during time-dependent stress-relaxation tests (p < 0.05). We hypothesize that this subtle alteration in time-dependent mechanical behavior is most-likely due to the increased prevalence of irregularly shaped type I collagen fibrils in the mutant tail tendons. These findings provide additional evidence to support the conclusion that GDF-5 may play a role in tendon homeostasis in mice.

Tapeworm identification in the fat sand rat (Psammomys obesus obesus)

The identification of a tapeworm (Rodentolepis nana, formerly named Hymenolepis nana) infection in a research breeding colony of sand rats (Psammomys obesus obesus) was complicated because of the unexpected long length (< 150 mm) of the worms. Other morphologic features that were consistent with this identification included the number (24), size (16 mm), and shape of the hooks on the rostellum. No evidence of intermediate hosts was found in the colony. Previous surveys of natural populations of sand rats had not identified this tapeworm. However, a detailed search of the literature revealed that variation in the size of R. nana had been reported, thus supporting the final identification of the tapeworm. R. nana is important and interesting because of its zoonotic potential and because it is the only tapeworm that is able to infect its definitive host without use of an intermediate host. This report is presented to help clarify the ambiguity found in the laboratory animal literature about the differences in the size of R. nana among rodent species used in research.

Electricity from fossil fuels without CO2 emissions: assessing the costs of carbon dioxide capture and sequestration in U.S. electricity markets

The decoupling of fossil-fueled electricity production from atmospheric CO2 emissions via CO2 capture and sequestration (CCS) is increasingly regarded as an important means of mitigating climate change at a reasonable cost. Engineering analyses of CO2 mitigation typically compare the cost of electricity for a base generation technology to that for a similar plant with CO2 capture and then compute the carbon emissions mitigated per unit of cost. It can be hard to interpret mitigation cost estimates from this plant-level approach when a consistent base technology cannot be identified. In addition, neither engineering analyses nor general equilibrium models can capture the economics of plant dispatch. A realistic assessment of the costs of carbon sequestration as an emissions abatement strategy in the electric sector therefore requires a systems-level analysis. We discuss various frameworks for computing mitigation costs and introduce a simplified model of electric sector planning. Results from a "bottom-up" engineering-economic analysis for a representative U.S. North American Electric Reliability Council (NERC) region illustrate how the penetration of CCS technologies and the dispatch of generating units vary with the price of carbon emissions and thereby determine the relationship between mitigation cost and emissions reduction.

Characterization of U4 and U6 interactions with the 5' splice site using a S. cerevisiae in vitro trans-splicing system

Spliceosome assembly has been characterized as the ordered association of the snRNP particles U1, U2, and U4/U6.U5 onto pre-mRNA. We have used an in vitro trans-splicing/cross-linking system in Saccharomyces cerevisiae nuclear extracts to examine the first step of this process, 5' splice site recognition. This trans-splicing reaction has ATP, Mg(2+), and splice-site sequence requirements similar to those of cis-splicing reactions. Using this system, we identified and characterized a novel U4-5' splice site interaction that is ATP-dependent, but does not require the branch point, the 3' splice site, or the 5' end of the U1 snRNA. Additionally, we identified several ATP-dependent U6 cross-links at the 5' splice site, indicating that different regions of U6 sample it before a U6-5' splice site interaction is stabilized that persists through the first step of splicing. This work provides evidence for ATP-dependent U4/U6 association with the 5' splice site independent of ATP-mediated U2 association with the branch point. Furthermore, it defines specific nucleotides in U4 and U6 that interact with the 5' splice site at this early stage, even in the absence of base-pairing with the U1 snRNA.

Quinazolines as cyclin dependent kinase inhibitors

Quinazolines have been identified as inhibitors of CDK4/D1 and CDK2/E. Aspects of the SAR were investigated using solution-phase, parallel synthesis. An X-ray crystal structure was obtained of quinazoline 51 bound in CDK2 and key interactions within the ATP binding pocket are defined.

Pilot study of dental hygienists' comfort and confidence levels and care planning for patients with disabilities

A questionnaire assessing comfort levels and behaviors of dental hygienists concerning treatment of patients with special needs or disabilities was mailed to a random sample of 175 practicing dental hygienists in Idaho. All respondents had seen patients with disabilities, although 53 percent had never completed a formal course or received training directed specifically toward this population. Survey respondents were moderately to always comfortable treating special needs and disabled patients. Use of a wheelchair was the only disability in which clinicians were significantly more comfortable with treatment following completion of a course or receipt of training. Severity of a patient's disability and limited time were considered moderate to very high barriers to the provision of dental hygiene care. Recommended treatment planning techniques are being used to a limited extent, and respondents were slightly to moderately confident using alternative communication and treatment techniques. The findings suggest that although education or training was not strongly associated with comfort and confidence levels of these dental hygienists, they were interested in opportunities for further training in caring for patients with special needs.

G8363A mutation in the mitochondrial DNA transfer ribonucleic acidLys gene: another cause of Leigh syndrome

We identified a G-->A transition at nt-8363 in the mitochondrial DNA transfer ribonucleic acidLys gene in blood and muscle from a 13-month-old girl who had clinical and neuroradiologic evidence of Leigh syndrome and died at age 27 months. The mutation was less abundant in the same tissues from the patient's mother, who developed myoclonus epilepsy with ragged red fibers (MERRF) in her late 20s. In both mother and daughter, muscle histochemistry showed ragged red and cytochrome c oxidase-negative fibers and biochemical analysis showed partial defects of multiple respiratory-chain enzymes. A maternal half-sister of the proband had died at 2.5 years of age from neuropathologically proven Leigh syndrome. The G8363A mutation, which previously had been associated with cardiomyopathy and hearing loss, MERRF, and multiple lipomas, also should be included in the differential diagnosis of maternally inherited Leigh syndrome.

Continuing participation supports ultrasound screening for ovarian cancer

The effect of ovarian cancer screening on survival is enabled by women who continue to actively participate in screening. In this report, factors that affect participation are examined. Participants included 13,963 Kentucky women who received 56,392 screens accounting for a 46,113 screening year experience. Background, health history and reasons for participating in transvaginal sonographic screening were collected via a self-reported questionnaire. Screening participants were characterized as > 50 years old, mostly married, well educated, medically insured, health conscious women, living in the vicinity of the screening centre or 51-150 miles away. Approximately 70% of the participants can be considered active in the study based upon a screening visit during the 1997-1998 2-year period. The probabilities of a return screen at 1, 2, 5 and 7.5 years were 77.8%, 72.0%, 58.7% and 50.6%, respectively. A total of 96% of return visits occurred within 2 years, with 33.7% having intervals of < 1 year. Perceived family history was not observed to affect continuation. However, abnormal findings were associated with a shortened participation. These high levels of continuation in ultrasound screening indicate that women take this disease seriously and demonstrate that this disease is of consequence to them.

Differential effects of embryonic immobilization on the development of fibrocartilaginous skeletal elements

The importance of mechanical influences during skeletal development has been well established in both experimental studies and computer models. Under conditions of embryonic immobilization, it has been observed that the early stages of joint formation proceed normally (up to and including interzone formation), but the later stages of joint cavitation and maintenance are impaired, resulting in fusion of the cartilaginous elements across the presumptive joint line. Two structures in particular are noticeably absent from late-stage synovial joints in immobilized chick embryos: the menisci of the tibiofemoral joint and the plantar tarsal sesamoid of the tibiotarsal joint. Both of these fibrocartilaginous structures are known to serve mechanical functions in postnatal animals, helping to distribute loads within the joint and, in the case of sesamoid structures, to provide a mechanical advantage to muscles acting across the joint. We demonstrate in this study that embryonic immobilization differentially affects the developmental fate of these two distinct fibrocartilages. The absence of the plantar tarsal sesamoid in late-stage immobilized embryos is due to a failure in the initial formation of this structure. In contrast, the early stages of meniscus formation proceed normally. Without the normal mechanical stimuli of skeletal muscle contractions, however, the meniscus fails to mature and ultimately degenerates.

Partial tracheal obstruction due to chondromas in ball pythons (Python regius)

Over a 9-mo period, three adult ball pythons (Python regius) (one male, two females) were evaluated for severe dyspnea. Partial obstructions of the tracheal lumen were identified radiographically and/or visualized with a 3.0-mm rigid laparoscope inserted into the tracheal lumen in all three snakes. Administration of systemic antibiotics and nebulization resulted in partial improvement of the dyspnea. In two snakes, the tracheal lesions were removed with a rigid laparoscope and a flexible biopsy instrument inserted into the tracheal lumen. The other snake died and was necropsied. Histologically, the lesions from two snakes were determined to be benign chondromas. The chondromas were composed of a variably disorganized chondroid matrix populated by quiescent, normal-appearing chondrocytes within lacunae, although the chondrocytes were increased in density compared with normal hyaline cartilage and contained rare mitotic figures. The tracheal masses in one snake grew by expansion, not invasion, and were focally continuous with a mineralized cartilage tracheal ring, suggesting a benign nature. This is the second report of tracheal chondroma in ball pythons. Tracheal chondromas are exceedingly rare in humans and domesticated animals, suggesting a possible predisposition of ball pythons for this neoplasm.

A skin blister method to study epidermal nerves in peripheral nerve disease

Skin is a reservoir of sensory and autonomic nerve fibers that are potential indicators of peripheral nerve disease. Biopsies of skin have shown that sensory nerves in the most superficial layer of skin, the epidermal nerve fibers (ENFs), are reduced in patients with polyneuropathy. This report describes a minimally invasive skin blister method to isolate, image, and obtain quantitative analysis of ENFs. Blisters are made by applying a suction capsule to skin. The epidermal roof of the blister is excised, immunostained, whole mounted, and analyzed for ENF number and distribution. A reduction in number and abnormal distribution of ENFs are early indicators of peripheral nerve disease. Illustrations of skin blister and skin biopsy specimens from patients with different types of peripheral nerve disorders are included. These patients were chosen because their findings demonstrate the complementary information obtained by the blister and biopsy methods and the potential of the blister procedure to evaluate single nerve lesions and polyneuropathy and to follow the progress of ENF degeneration and regeneration.

Health care needs of medically underserved women of color: The role of the Bureau of Primary Health Care

The Bureau of Primary Health Care (BPHC) was developed to increase access to comprehensive primary and preventive health care and to improve the health status of medically underserved populations. Approximately 43 million Americans fall into this category, and the majority are poor, female, young, and uninsured. Under the Public Health Services Act, BPHC does not provide direct services, but rather assist local communities in identifying populations at risk of poor health outcomes and helps these communities through various programs. One of the newest initiatives of BPHC is the Office of Minority and Women's Health, developed with a mission to help reduce the disparities in the health status of women of racial and ethnic minority populations. This article outlines these disparities and discusses proposals for reducing them.

Physician gender and women's preventive services

OBJECTIVE

To determine whether the gender of women's regular physicians, controlling for physician specialty, is associated with women's receiving key preventive services within recommended intervals.

DESIGN

Cross-sectional, nationally representative women's health telephone survey conducted by Louis Harris and Associates in February and March 1993 for The Commonwealth Fund.

PARTICIPANTS

A total of 2,525 women in the continental United States, > or = 18 years old, including oversamples of African-American and Hispanic women.

MAIN OUTCOME MEASURES

Receipt of each of five preventive services (blood pressure reading, Pap smear, cholesterol test, clinical breast examination, and mammogram) within specific periods.

RESULTS

Physician gender makes a significant difference for two specialty areas and for three preventive services. Patients of women family or general practitioners are more likely than the patients of men to have received a Pap smear or a blood cholesterol test within the last 3 years, and the patients of women internists are more likely to have received a Pap test. Physician gender is associated with a higher likelihood of mammography, but this finding was limited to patients ages 40-49 of women family or general practitioners. Physician gender does not affect receipt of blood pressure screening or breast examination.

CONCLUSIONS

Analyses reveal limited evidence that physician gender affects women's receipt of preventive services. Physician specialty appears to be a more powerful predictor of preventive services received. The limited evidence for a physician gender effect, however, is relevant for those women who rely on a family or general practitioner or an internist for regular care.

Structure-activity relationships of the antimalarial agent artemisinin. 5. Analogs of 10-deoxoartemisinin substituted at C-3 and C-9

Novel 3- and 9-substituted analogs (4-19) of 10-deoxoartemisinin, 3, were prepared from the corresponding known lactones by one-pot reduction with sodium borohydride and boron trifluoride etherate. Reproducibility problems associated with this heterogeneous reaction were encountered on small reaction scales, and thus alternative methodology was sought for this reduction. Conversion of the lactones to tetrahydropyrans via the corresponding intermediate lactols was made more reproducible using a two-step sequence involving low-temperature reduction with diisobutylaluminum hydride followed by deoxygenation with boron trifluoride etherate in the presence of triethylsilane. In this manner, 10-deoxoartemisinin (3) could be obtained from artemisinin (1) in greater than 95% overall yield. All analogs were tested in vitro against W-2 and D-6 strains of Plasmodium falciparum. Several of the analogs were much more active than the natural product (+)-artemisinin (1) or 10-deoxoartemisinin (3). Conventional structure-activity relationships are discussed in relation to the bioassay data.

Metaplastic breast carcinoma: a cytohistologic and clinical study of 10 cases

Metaplastic breast carcinomas (MBC) account for < 5% of breast malignancies and have an uncertain prognostic significance. The tumors tend to grow rapidly, and most are negative for hormone receptors. Adenosquamous carcinomas and various types of carcinosarcomas may be classified as MBC. We evaluated the cytologic, histologic, and clinical parameters of 10 MBC to determine important diagnostic features of these tumors. A cytologic diagnosis of MBC, based on the identification of two distinct malignant components, was made preoperatively in five of 10 (50%) cases, and retrospectively in two additional cases; two specimens were inadequately cellular. Poorly-differentiated adenocarcinoma was the most frequently encountered component of MBC. It is recommended that malignant breast aspirates be carefully scrutinized for multiple neoplastic components. Our series of MBC differs from previous reports in that two cases presented as inflammatory breast cancer, one case was pregnancy-associated, and there was a higher incidence of estrogen and progesterone receptor positivity. No cancer-related deaths occurred during a mean follow-up period of over 6 yr.

Endometrial metaplasia as a source of atypical glandular cells in cervicovaginal smears

Cytohistological correlation of abnormal cervicovaginal smears indicates that endometrial metaplasia may be associated with the presence of atypical glandular cells. Seven patients with histologically confirmed endometrial metaplasia had atypical glandular cells in cervicovaginal smears; five smears were interpreted as being suspicious for endometrial adenocarcinoma. Most of the patients (5/7) were postmenopausal (mean age = 61.3 years), and three of seven patients had abnormal vaginal bleeding. The corresponding endometrial tissue specimens demonstrated various combinations of eosinophilic, papillary, squamous, and tubal metaplasia; in one case tubal metaplasia occurred in association with an endometrial polyp. Cytologic features noted in the cervicovaginal smears from all seven patients were similar and included small clusters of atypical glandular cells in an inflammatory background. Intracytoplasmic vacuoles were often present, and a moderate degree of aniosonucleosis was noted. Enlarged glandular nuclei contained finely granular chromatin and distinct nucleoli. The differential diagnosis of atypical glandular cells includes endometrial hyperplasia and well-differentiated endometrial adenocarcinoma. The atypical cells associated with endometrial metaplasia were characterized by a relatively low N:C ratio and evenly distributed chromatin. In contrast, the cells of endometrial carcinoma typically demonstrate increased N:C ratios and irregularly distributed chromatin.

Update on the surgical pathology of the vulva

Recent developments in the surgical pathology of the vulva include updated classifications of non-neoplastic epithelial disorders and vulvar intraepithelial neoplasias. Several histologic variants of vulvar squamous cell carcinoma (SCC) with distinct clinicopathologic features have been described. The concept of superficially invasive vulvar SCC continues to be a complex issue. The use of standardized surgical pathology reports and checklists are recent developments in surgical pathology.

Squamous cell carcinoma of the cervix metastatic to an ovarian Brenner tumor

Metastatic tumors account for approximately 10 to 15% of surgically excised ovarian malignancies (Semin Diagn Pathol 8:250-276, 1991). Although the majority of tumors arise within the female genital tract, cervical cancer is a rare source of metastasis to the ovary. Cervical carcinomas with ovarian involvement are usually advanced lesions with lymph node involvement (Am J Obstet Gynecol 166:50-53, 1992; Cancer 71:407-418, 1993). We present a case of Stage IIB squamous cell carcinoma of cervix metastatic to an ovarian Brenner tumor. Our purpose in presenting this case is to report useful histologic features in the diagnosis of this rare combination of tumors. We are not aware of any other published reports of this entity.

Prevalence of HPV 16 and 18 DNA sequences in CIN III lesions of adults and adolescents

Adolescents may be more susceptible to cervical human papillomavirus (HPV) infections and may have more rapid progression of cervical intraepithelial neoplastic (CIN) lesions than adults. We evaluated Papanicolaou (Pap) smears and cervical tissue specimens from a consecutive series of 25 adolescent (age 15-20 yr) and 17 adult (age 35-40 yr) patients with a histologic diagnosis of CIN III. The study patients were all Detroit residents enrolled in a health maintenance organization (HMO) affiliated with Henry Ford Hospital. The cervical tissue specimens were evaluated for HPV 6b/11, HPV 16, and HPV 18 using agarose gel electrophoresis and Southern hybridization following polymerase chain reaction (PCR) DNA amplification. While the small sample size precluded testing for statistical significance, HPV 16 and/or HPV 18 DNA was detected in specimens from 21/25 (84%) adolescents compared to 12/17 (71%) adults (odds ratio [OR] = 2.2; 95% confidence interval [CI] = 0.49-9.74). The relationship between adolescence and HPV infections appears to be stronger for HPV 18 and mixed HPV 16/18 infections (OR = 5.6; 95% CI = 0.7-42.4) than for HPV 16 infections (OR = 1.93; 95% CI = 0.4-8.8). None of the cervical specimens contained HPV 6b/11 DNA. Oral contraceptive (OC) use was associated with HPV infection in patients with CIN III, but there was no association between cigarette smoking and HPV infection. The effect of OC use on the relationship of age and HPV could not be evaluated due to small sample size. The effects of previous sexually transmitted disease (STD) on the relationship of age and HPV were assessed.(ABSTRACT TRUNCATED AT 250 WORDS)

Complexes of yeast RNA polymerase II and RNA are substrates for TFIIS-induced RNA cleavage

In the absence of DNA, purified yeast RNA polymerase II can bind RNA to form a binary complex. RNA in such RNA-RNA polymerase complexes undergoes reactions previously thought to be unique to nascent RNA in ternary complexes with DNA, including TFIIS-dependent cleavage and elongation by 3'-terminal addition of NMP from NTP. Both of these reactions are inhibited by alpha-amanitin. Hence, by several criteria the RNA in binary complexes is bound to the polymerase in a manner quite similar to that in ternary complexes in which the catalytic site for nucleotide addition is positioned at or near the 3'-OH terminus of the RNA. These findings are consistent with a model for the RNA polymerase ternary complex in which the RNA is bound at the 3' terminus through two protein-binding sites located up to 10 nt apart.

Diagnosis of low back pain, secondary to prostate metastasis to the lumbar spine, by digital rectal examination and serum prostate-specific antigen

OBJECTIVE

To present a case in which the initial diagnosis of spinal metastasis secondary to prostate cancer was established from findings of the digital rectal examination (DRE) and serum prostate-specific antigen (PSA) analysis.

CLINICAL FEATURES

A 79-yr-old black male was seen after suffering from low back pain for 1 month. Urinary frequency and nocturia were associated symptoms. Abnormal findings on the DRE and serum PSA determination suggested a preliminary diagnosis of spinal metastases secondary to prostate cancer. Subsequent referral for biopsy and bone scan yielded the final diagnosis of prostate adenocarcinoma with spinal metastasis. Radiographs of the lumbosacral spinal region were inconclusive and results of routine laboratory tests (CBC, ESR, U/A) were within normal limits.

INTERVENTION AND OUTCOME

The patient was referred for medical palliation of his condition. A bilateral orchiectomy was performed along with oral antiandrogen administration. At a consultation 8 months postoperatively, he reported to be free of pain.

CONCLUSION

At least 40% of newly diagnosed cases of prostate cancer can be expected to have metastasized at the time of initial discovery. Routine use of DRE and serum PSA in patients complaining of low back pain who are at high risk for prostate cancer is recommended. However, mass screening with DRE or PSA in asymptomatic males is not recommended. There are no prospective studies showing evidence that mass screening for prostate cancer will reduce the mortality or morbidity rates from the disease.

Gentamicin toxicosis in a North American cougar

This report documents nephrotoxicosis in a North American cougar (Felis concolor) caused by gentamicin overdose and describes a method of calculating drug dosages by metabolic scaling for species in which pharmacokinetic studies have not been performed. Determining drug dosages by metabolic scaling can decrease the likelihood of administering inappropriate drug doses in exotic animals.

Worsening tricuspid regurgitation following pericardiectomy for constrictive pericarditis

We describe two cases of worsening tricuspid regurgitation following surgical pericardiectomy for constrictive pericarditis. Both patients demonstrated hemodynamic profiles characteristic of constrictive pericarditis on cardiac catheterization. They also had moderate tricuspid regurgitation as judged by Doppler echocardiography. The worsening tricuspid regurgitation observed was a result of postoperative right ventricular dilatation. These cases demonstrate the importance of determining tricuspid valvular function in patients with constrictive pericarditis prior to pericardiectomy; however, the hemodynamic changes that result in worsening tricuspid regurgitation may not be present for weeks.

Cytologic features of metastatic transitional cell carcinoma

Cytologic preparations containing metastatic transitional cell carcinoma (MTCC) from 18 sites in 16 patients were reviewed to determine characteristic morphologic features. The patient group included 13 males and 3 females with a mean age of 66 years. Primary TCC occurred in the bladder (14), kidney (1), and ureter (1); nearly all the primary tumors were poorly differentiated and most were invasive at the time of diagnosis. The cytologic specimens were derived from lymph nodes (6), liver (4), serous fluids (2), pelvic soft tissue (2), subcutaneous nodules (2), and lung (1). One patient presented with MTCC in Pap smears. Cytologically MTCC presented as loosely cohesive, moderate to markedly pleomorphic cells which occurred singly and in syncytial clusters. The malignant cells were usually large with abundant granular or fibrillar cytoplasm and the cell borders were generally distinct. Most nuclei were large and hyperchromatic with irregularly distributed granular chromatin and prominent nucleoli. The most distinctive features were the presence of spindled, pyramidal, and/or racquet-shaped malignant cells with eccentric nuclei and cytoplasmic features of both squamous and glandular differentiation including endoplasmic/ectoplasmic interfaces and intracytoplasmic vacuoles. Although clinical history is most useful in the diagnosis of MTCC, these morphologic features in cytologic preparations of malignant epithelial neoplasms may be helpful. In the absence of a known primary TCC, it is doubtful that a definite cytologic diagnosis could be made; however, the characteristic cell shapes and cytoplasmic features may be suggestive of MTCC.

Use of an implant for intraosseous infusion as supportive therapy for a Vietnamese pot-bellied pig with urethral obstruction caused by a polyp

A Vietnamese pot-bellied pig with a urethral polyp was supported by total parenteral nutrition given through an intraosseous implant. Peripheral vascular access was difficult to establish and maintain in this anorectic pig, so a pediatric intraosseous implant was placed in the left tibia. Surgical repair of the urethra was not considered possible, and alternative techniques of a functional bypass were unacceptable to the owners, so euthanasia was elected. Histologic examination of the urethra revealed a polypoid structure believed to be similar to benign congenital polyps described in young boys.

Effects of combining transforming growth factor beta and 1,25-dihydroxyvitamin D3 on differentiation of a human osteosarcoma (MG-63)

Transforming growth factor beta (TGF beta) and 1,25-dihydroxyvitamin D3 (1,25D3), when added simultaneously to a human osteosarcoma cell line, MG-63, induce alkaline phosphatase activity 40-70-fold over basal levels, 6-7-fold over 1,25D3 treatment alone, and 15-20-fold over TGF beta treatment alone. TGF beta and 1,25D3 synergistically increased alkaline phosphatase specific activity in both matrix vesicles and plasma membrane isolated from the cultures, but the specific activity was greater in and targeted to the matrix vesicle fraction. Inhibitor and cleavage studies proved that the enzymatic activity was liver/bone/kidney alkaline phosphatase. Preincubation of MG-63 cells with TGF beta for 30 min before addition of 1,25D3 was sufficient for maximal induction of enzyme activity. Messenger RNA for liver/bone/kidney alkaline phosphatase was increased 2.1-fold with TGF beta, 1.7-fold with 1,25D3, and 4.8-fold with the combination at 72 h. Human alkaline phosphatase protein as detected by radioimmunoassay was stimulated only 6.3-fold over control levels with the combination. This combination of factors was tested for their effect on production of three other osteoblast cell proteins: collagen type I, osteocalcin, and fibronectin. TGF beta inhibited 1,25D3-induced osteocalcin production, whereas both factors were additive for fibronectin and collagen type I production. TGF beta appears to modulate the differentiation effects of 1,25D3 on this human osteoblast-like cell and thereby retain the cell in a non-fully differentiated state.

Ulcer recurrence following duodenal ulcer healing with omeprazole, ranitidine, or placebo: a double-blind, multicenter, 6-month study. The Omeprazole Duodenal Ulcer Study Group

The present study determined whether the rate of relapse of duodenal ulcer was reduced after ulcer healing with omeprazole compared with ranitidine or placebo. It was made up of a double-blind, randomized, controlled multiple-center trial set within the United States. Patients were candidates if their duodenal or pyloric channel ulcer successfully healed in one of two large multicenter U.S. trials; one compared omeprazole, 20 mg once daily, before breakfast with ranitidine, 150 mg twice daily, and the other compared the same dose of omeprazole with placebo. Two hundred forty (73.8%) of the 325 patients with complete ulcer healing within 4 weeks of starting therapy who were eligible to enter the follow-up study were enrolled. There was no intervention. Endoscopic assessment of ulcer status was performed at 2, 4, and 6 months and whenever patients had symptoms thought to represent return of an ulcer. The lifetable relapse rates for duodenal ulcer according to initial ulcer therapy with omeprazole, ranitidine, or placebo were 76.7% [95% confidence interval (CI), 64%-89.3%], 59.8% (95% CI, 47.8-71.7%), and 50.4% (95% CI, 15.7%-85.2%), respectively. These rates were not statistically significantly different. Seventeen percent of recurrent ulcers occurred at a site different from that of the original ulcer. It is concluded that despite the more rapid rate of duodenal ulcer healing with omeprazole therapy, the rate of ulcer relapse appears similar and independent of whether ulcer healing was accelerated with omeprazole or ranitidine.

Detection of HPV 16/18 DNA in cervical adenocarcinoma using polymerase chain reaction (PCR) methodology

Twenty-two tissue samples of primary adenocarcinoma (adenoCA) of the uterine cervix were evaluated for the presence of HPV 16/18 DNA using the polymerase chain reaction (PCR). PCR was used to specifically amplify the E6-E7 gene region of HPV 16/18 DNA. The amplification products were analyzed using gel electrophoresis and Southern dot blotting with 32p labeled type-specific oligonucleotide probes. HPV 18 DNA was identified in 13/22 (59%) and HPV 16 DNA was identified in 5/22 (23%) of the tumors. There were no tumors with mixed infections. In three patients, two different specimens were evaluated, and there was concordance of HPV typing. The presence of squamous carcinoma in situ, koilocytosis and younger patient age were associated with an increased incidence of HPV 16/18 DNA detection. HPV 16/18 DNA was not detected in six metastatic adenoCA to cervix (four endometrial, two ovarian). We conclude that HPV 16/18 DNA is present in a significant proportion of primary adenoCA of the cervix, and we have identified some clinicopathologic associations. The detection of HPV DNA may be useful in distinguishing primary from metastatic adenoCA of the cervix.

Chromosomal assignment in mouse of matrix Gla protein and bone Gla protein genes

Matrix Gla protein (MGLAP) and bone Gla protein (BGLAP) are calcium-binding, vitamin K-dependent proteins produced by cells of the osteoblastic lineage. Sequence homology suggests that the genes for these proteins evolved from a common ancestor. Somatic whole cell hybrids and karyotypically simple microcell hybrids were used to map Mglap to mouse Chromosome 6 and Bglap to mouse Chromosome 3. Human MGLAP has previously been mapped to chromosome 12p, a region with homology to mouse Chromosome 6, and human BGLAP has been mapped to chromosome 1q, a region with homology to mouse Chromosome 3. It appears that BGLAP is the third calcium-binding protein that maps to human chromosome 1q and mouse Chromosome 3.

Lymphangioma circumscriptum of the vulva. A report of two cases

Lymphangioma circumscriptum is an uncommon dermatologic problem that only rarely affects the vulva. It is considered to be a circumscribed developmental defect of lymphatic tissue in the dermis. We encountered two patients whose clinical manifestations required management with extensive vulvar surgery. These cases illustrate the spectrum of presentation of this disorder and its treatment.

Tuberculous Addison's disease

Addison's disease is a possible diagnosis in any patient who presents with weakness, weight loss, hyperpigmentation, hyponatremia, and hypotension. Laboratory findings, including depressed levels of cortisol and aldosterone, help to confirm the diagnosis. Computed tomography may reveal adrenal calcification and abnormal-sized adrenal glands. In most cases, autoimmune destruction of the adrenal cortex is the cause of Addison's disease; however, as in the patient described here, tuberculosis is a possible cause.