Susceptibility to Myxobolus cerebralis among Tubifex tubifex populations from ten major drainage basins in Colorado where Cutthroat Trout are endemic.

Establishment of Myxobolus cerebralis (Mc) resulted in declines of wild Rainbow Trout Oncorhynchus mykiss populations in streams across Colorado during the 1990s. However, the risk for establishment and spread of this parasite into high-elevation habitats occupied by native Cutthroat Trout O. clarkii was unknown. Beginning in 2003, tubificid worms were collected from all major drainages where Cutthroat Trout were endemic and were assayed by quantitative PCR to determine the occurrence and distribution of the various lineages of Tubifex tubifex (Tt) oligochaetes. Over a 5-year period, 40 groups of Tt oligochaetes collected from 27 streams, 3 natural lakes, 2 private ponds, and a reservoir were evaluated for their relative susceptibility to Mc. Exposure groups were drawn from populations of pure lineage III Tt, mixed-lineage populations where one or more of the highly resistant (lineage I) or nonsusceptible lineages (V or VI) were the dominant oligochaete and susceptible lineage III worms were the subdominant worm, or pure lineage VI Tt. Experimental replicates of 250 oligochaetes were exposed to 50 Mc myxospores per worm. The parasite amplification ratio (total triactinomyxons [TAMs] produced / total myxospore exposure) was very high among all pure lineage III Colorado exposure groups, averaging 363 compared with 8.24 among the mixed-lineage exposure groups. Lineage III oligochaetes from Mt. Whitney Hatchery in California, which served as the laboratory standard for comparative purposes, had an average parasite amplification ratio of 933 among 10 exposed replicates over a 5-year period. Lineage I oligochaetes were highly resistant to infection and did not produce any TAMs. Lineages V and VI Tt did not become infected and did not produce any TAMs. These results suggest that the risk of establishment of Mc is high for aquatic habitats in Colorado where Cutthroat Trout and lineage III Tt are sympatric.

Reduced Myxobolus cerebralis actinospore production in a Colorado reservoir may be linked to changes in Tubifex tubifex population structure.

Elucidating the dynamics of a parasitic infection requiring two hosts in a natural ecosystem can be a daunting task. Myxobolus cerebralis (Mc), the myxozoan parasite that causes whirling disease in some salmonids, was detected in the Colorado River upstream of Windy Gap Reservoir (WGR) in 1988. Subsequently, whirling disease was implicated in the decline of wild Rainbow Trout Oncorhynchus mykiss in the river when WGR was identified as a point source of Mc triactinomyxons (TAMs). Between 1997 and 2004, numerous investigations began to elucidate the etiology of Mc in WGR. During this period, Mc TAM production in WGR declined more than 90%. Explanations for the decline have included differences in stream discharge between years, changes in the thermal regime of the lake, severe drought, changes in the fish population structure in WGR, and reductions in the prevalence and severity of Mc infection in salmonids in the Colorado and Fraser rivers upstream of WGR. All of these have been discredited as explanations for the reduced TAM production. In 2005, a new study was conducted to replicate the studies completed in 1998. In this paper, the results of a new real-time polymerase chain reaction assay utilized to quantify the mitochondrial 16S rDNA specific to each of four lineages of Tubifex tubifex in pooled samples of 50 oligochaetes are presented. These results suggest that compared with 1998, the densities of aquatic oligochaetes and T. tubifex have increased, TAM production has been greatly reduced, and the decline is congruent with the dominance of lineages I, V, and VI of T. tubifex-three lineages that are refractory or highly resistant to Mc infection-in the oligochaete population. While it is possible that the resistant lineages function as biofilters that deactivate Mc myxospores, the reason for the decline in TAM production in WGR remains an enigma.

Quantitative real-time PCR analysis of total and propidium monoazide-resistant fecal indicator bacteria in wastewater.

A real-time quantitative PCR (qPCR) method and a modification of this method incorporating pretreatment of samples with propidium monoazide (PMA) were evaluated for respective analyses of total and presumptively viable Enterococcus and Bacteroidales fecal indicator bacteria. These methods were used in the analyses of wastewater samples to investigate their feasibility as alternatives to current fecal indicator bacteria culture methods for predicting the efficiency of viral pathogen removal by standard treatment processes. PMA treatment was effective in preventing qPCR detection of target sequences from non-viable cells. Concentrates of small volume, secondary-treated wastewater samples, collected from a publicly owned treatment works (POTW) under normal operating conditions, had little influence on this effectiveness. Higher levels of total suspended solids, such as those associated with normal primary treatment and all treatment stages during storm flow events, appeared to interfere with PMA effectiveness under the sample preparation conditions employed. During normal operating conditions at three different POTWs, greater reductions were observed in PMA-qPCR detectable target sequences of both Enterococcus and Bacteroidales than in total qPCR detectable sequences. These reductions were not as great as those observed for cultivable fecal indicator bacteria in response to wastewater disinfection. Reductions of PMA-qPCR as well as total qPCR detectable target sequences from enterococci and, to a lesser extent, Bacteroidales correlated well with reductions in infectious viruses during both normal and storm flow operating conditions and therefore may have predictive value in determining the efficiency at which these pathogens are removed.

Seating and pressure support needs of people with cancer in the cervix or rectum: a case series on the clinical usefulness of pressure mapping assessment.

Pressure sores present a challenge to people with rectal and cervical cancers due to weight loss, compromised nutrition, chemotherapy and radiotherapy. Affected individuals often experience intense pain on sitting, and prefer to spend the majority of their time lying down. This pilot study, employing a case study design, investigated the pressure care needs of such persons using pressure mapping, a technology designed to measure pressures at the seating interface. Four participants were mapped on a selection of five cushions, three of which were developed to specifically reduce midline posterior pressure/pain relief. Participants rated the cushions for comfort. Findings demonstrated an inconsistent relationship between interface pressures and perceived cushion comfort, suggesting that patient-rated comfort is a poor indicator of high interface pressures. The specialized cushions did not always meet the needs of this target population and no one cushion suited all. This study demonstrated the precarious clinical balance needed between comfort and achieving optimal pressure reduction in cushion prescription for this client group, and suggested that comfort was more important than pressure reduction in terms of their seating needs.

Interface pressure measurements: visual interpretation of pressure maps with MS clients.

PURPOSE: Pressure mapping systems provide useful information for pressure care assessment. Healthcare professionals tend to rely upon their colour-coded pressure maps to assist clinical decision-making, based on ranking these from best to worst pressure distribution. The current study investigated whether such ranking is an appropriate method of assessment when compared to use of the numerical output of average and maximum pressure values (mmHg), yielded by the system. METHOD: This community-based correlational study involved 27 multiple sclerosis clients (15 wheelchair users; 12 non-wheelchair users). Pressure maps were recorded on each participant's current seating surface and on six pressure reducing cushions, using the Force Sensing Array pressure mapping system. Outcome measures included (1) rank order of pressure maps based on visual interpretation by two occupational therapists, (2) average pressure (mmHg) and (3) maximum pressure (mmHg). Visual ranking of the colour-coded pressure maps was correlated with average and maximum pressure values for each map. RESULTS: Correlations between visual ranking of maps and maximum pressures were high for six out of seven surfaces (p < 0.05) for non-wheelchair users; however, they were much less between average pressures and visual interpretation for the same cohort. Similarly, correlations between visual ranking of maps and average pressures for wheelchair users was minimal and was only noted as being high (p < 0.05) on two surfaces when considering maximum pressures and visual interpretation. CONCLUSIONS: This study contests the usefulness of the visual ranking of pressure maps in interpreting interface pressures with MS clients, especially with wheelchair users. Visual interpretation of pressure maps by clinicians may be useful in eliminating inappropriate support surfaces from a selection, or those that display easily identifiable 'extremes' of pressure values. Clinicians need to incorporate and interpret the numerical data as well as pressure maps when conducting their assessment and making provision.

Transverse pressure distributions in a simple model ear canal occluded by a hearing aid test fixture.

The sound field in a model ear canal with a hearing aid test fixture has been investigated experimentally and theoretically. Large transverse variations of sound pressure level, as much as 20 dB at 8 kHz, were found across the inner face of the hearing aid. Variations are greatest near the outlet port of the receiver and the vent port. Deeper into the canal, the transverse variations are less significant and, at depths greater than 4 mm, only a longitudinal variation remains. The model canal was cylindrical, 7.5 mm diameter, and terminated with a Zwislocki coupler to represent absorption by the human middle ear. The outer end of the canal was driven by the receiver in the hearing aid test fixture, with the acoustic output entering the canal through a 1 mm port. The hearing aid was provided with a 20-mm-long vent, either 1 or 2 mm in diameter. The sound field inside the canal was measured using a specially designed 0.2-mm-diam probe microphone [Daigle and Stinson, J. Acoust. Soc. Am. 116, 2618 (2004)]. In parallel, calculations of the interior sound field were performed using a boundary element technique and found to agree well with measurements.

Pressure mapping systems: reliability of pressure map interpretation.

BACKGROUND: Pressure mapping systems offer a new technology to assist with pressure care assessment. Data output from such systems can be presented in three forms: numerical data, a three-dimensional grid and a colour-coded pressure map. OBJECTIVES: To (1) investigate whether sole use of the pressure map was a reliable method of interpreting interface pressures when compared with use of the numerical data; (2) establish the inter- and intra-rater reliability of using pressure maps to assess pressure and determine whether reliability depended upon system operator experience; and (3) examine whether reliability extended to the range of seating surfaces being tested. DESIGN: A reliability study assessing the ranking of pressure maps recorded by the Force Sensing Array pressure mapping system. SETTING: A university occupational therapy department and a community NHS trust. SUBJECTS: Fifteen occupational therapists with experience in pressure mapping and 50 occupational therapy students with no practical experience of pressure mapping. INTERVENTIONS: Two sets of pressure maps were pre-recorded with an able-bodied adult seated on a variety of surfaces, with maps on each individual surface recorded over a 20-minute period at 2-minute intervals. Subjects ranked both sets of maps in terms of 'best to poorest' distribution of pressure. MAIN OUTCOME MEASURES: Rank orders of (1) pressure maps; (2) average interface pressures (mmHg); (3) maximum interface pressures (mmHg). RESULTS: The use of pressure maps to interpret interface pressures was a reliable method. Significant agreement existed within (p < 0.001) and between groups of operators and reliability extended over the range of seating surfaces tested. CONCLUSIONS: The practice of using pressure maps to interpret interface pressures in seating as opposed to using the associated numerical data can be supported. This was shown to be a reliable method of assessment by both experienced and less experienced operators across a range of seating surfaces.

The choice: Lewellys F. Barker and the full-time plan.

In 1914, Lewellys F. Barker, William Osler's successor as Professor of Medicine and physician-in-chief at Johns Hopkins University School of Medicine, resigned to enter private practice rather than accept the terms of a full-time plan, whereby professors in clinical departments would be salaried like other professors in the university. Barker had been an early proponent of the full-time plan. His decision reflected not only a personal desire for a larger income but also contradictions inherent in the Flexnerian ideal of clinical medicine as a research-oriented university discipline devoid of financial incentives to see patients. In private practice, Barker maintained a high profile as a teacher, writer, supporter of the Johns Hopkins medical institutions, and public figure. The issues raised by his difficult decision remain relevant and have not been satisfactorily resolved.

Outcomes of child sexual contacts: patterns of incarcerations from a national sample.

OBJECTIVE: In a test of the relationships between sexual touching before puberty and later incarcerations during adolescence and adulthood, two theoretical models were examined. These models focus on examination of crime from the developmental origins of criminals and the adaptive and maladaptive outcomes of early experiences. METHOD: Data were taken from the National Health and Social Life Survey to study the sexual touching and social origin variables in childhood and incarceration variable during teen years. The sample was a stratified, random sample of 3,362 adults (18 to 59 years of age) throughout the United States. RESULTS: Data support inferences from the two interrelated models. Respondents reporting touching before puberty were significantly more likely to experience incarceration. They were also more likely to engage in behaviors as teenagers that were associated with an increased probability of jailing. Such behaviors include sexual promiscuity and early departure from the parental family. CONCLUSIONS: These findings are consistent for first jailing as a teenager and as an adult, as well as for those with short (less than a week) or longer (a week or more) spells of incarceration. Prepubertal sexual touching has a significant and enduring effect on later adolescent and adult incarcerations.

In vivo stability of human chemokine and chemokine receptor expression.

Cross-sectional analyses of human PBMC, plasma, and tissue have reported altered chemokine and/or chemokine receptor expression in several inflammatory diseases. Interpretation of such studies is difficult without data on the in vivo stability of such parameters. Using four color flow cytometry, we longitudinally followed CXCR3, CCR5 (Th1-associated), and CCR3 (Th2-associated) expression within CD4+/CD45RO+ and CD8+/CD45RO+ T cell populations in peripheral blood of healthy individuals over a 21 day period. In parallel, we quantified plasma levels of IP-10, Mig, eotaxin and TARC. Chemokine and receptor expression differed markedly between subjects but was highly stable, varying by <5% within individuals. Differences in chemokine receptor expression between subjects were markedly altered when quantified as absolute cell numbers rather than frequencies. Finally, CCR3 expression by CD4+/CD45RO+ T cells was positively correlated with plasma levels of its ligand, eotaxin, whereas strong negative correlations were evident between CXCR3 expression and IP-10 or Mig. These data demonstrate longitudinal stability of chemokine receptor and ligand expression among healthy individuals; reveal that both frequency and absolute cell count analysis is essential for accurate assessment of chemokine receptor expression; and identify inverse relationships between type 1 and type 2 immunity-associated receptors and their ligands in vivo.

College Students' Perceptions of the C-Print Speech-to-Text Transcription System.

C-Print is a real-time speech-to-text transcription system used as a support service with deaf students in mainstreamed classes. Questionnaires were administered to 36 college students in 32 courses in which the C-Print system was used in addition to interpreting and note taking. Twenty-two of these students were also interviewed. Questionnaire items included student ratings of lecture comprehension. Student ratings indicated good comprehension with C-Print, and the mean rating was significantly higher than that for understanding of the interpreter. Students also rated the hard copy printout provided by C-Print as helpful, and they reported that they used these notes more frequently than the handwritten notes from a paid student note taker. Interview results were consistent with those for the questionnaire. Questionnaire and interview responses regarding use of C-Print as the only support service indicated that this arrangement would be acceptable to many students, but not to others. Communication characteristics were related to responses to the questionnaire. Students who were relatively proficient in reading and writing English, and in speech-reading, responded more favorably to C-Print.

The sign language skills classroom observation: a process for describing sign language proficiency in classroom settings.

In collaboration with teachers and students at the National Technical Institute for the Deaf (NTID), the Sign Language Skills Classroom Observation (SLSCO) was designed to provide feedback to teachers on their sign language communication skills in the classroom. In the present article, the impetus and rationale for development of the SLSCO is discussed. Previous studies related to classroom signing and observation methodology are reviewed. The procedure for developing the SLSCO is then described. This procedure included (a) interviews with faculty and students at NTID, (b) identification of linguistic features of sign language important for conveying content to deaf students, (c) development of forms for recording observations of classroom signing, (d) analysis of use of the forms, (e) development of a protocol for conducting the SLSCO, and (f) piloting of the SLSCO in classrooms. The results of use of the SLSCO with NTID faculty during a trial year are summarized.

Isolation and characterization of a human neutrophil aggregation defective mutant of Fusobacterium nucleatum.

Fusobacterium nucleatum is known to adhere to human polymorphonuclear neutrophils (PMNs) and cause them to aggregate. In this study, we isolated a spontaneously occurring aggregation defective (AGG(-)) mutant and this mutant will be used for future study of the interactions between this bacterium and human PMN. Genomic DNA fingerprinting by random-primed polymerase chain reaction method revealed a difference between the parent strain and the AGG(-) mutant. This mutant also showed an altered phenotype in both microbicidal and phagocytic assays, suggesting that the bacterial factor involved in the aggregation may also be very important for the phagocytosis and, subsequently, the killing by human PMNs. Further study of this mutant may help to clarify the molecular mechanisms of the interaction between this pathogen and human PMNs.

Streptococcal histone induces murine macrophages To produce interleukin-1 and tumor necrosis factor alpha.

The histone-like protein (HlpA) is highly conserved among streptococci. After lysis of streptococci in infected tissues, HlpA can enter the bloodstream and bind to proteoglycans in the glomerular capillaries of kidneys, where it can react with antibodies or stimulate host cell receptors. Deposits of streptococcal antigens in tissues have been associated with localized acute inflammation. In this study, we measured the ability of purified HlpA (5 to 100 microg/ml), from Streptococcus mitis, to induce the production of proinflammatory cytokines by cultured, murine peritoneal macrophages. The release of tumor necrosis factor alpha (TNF-alpha) and interleukin-1 (IL-1) was time and concentration dependent and was not diminished by the presence of polymyxin B. Exposure of macrophages to a mixture of HlpA and lipoteichoic acid resulted in a synergistic response in the production of both TNF-alpha and IL-1. Stimulation with a mixture of HlpA and heparin resulted in reduced cytokine production (50% less IL-1 and 76% less TNF-alpha) compared to that by cells incubated with HlpA alone. The inclusion of antibodies specific to HlpA in macrophage cultures during stimulation with HlpA did not affect the quantity of TNF-alpha or IL-1 produced. These observations suggest that streptococcal histone may contribute to tissue injury at infection sites by promoting monocytes/macrophages to synthesize and release cytokines that initiate and exacerbate inflammation. Streptococcus pyogenes, which can infect tissues in enormous numbers, may release sufficient amounts of HlpA to reach the kidneys and cause acute poststreptococcal glomerulonephritis.

Influence of environmental conditions on hydrogen peroxide formation by Streptococcus gordonii.

Hydrogen peroxide generated by viridans group streptococci has an antagonistic effect on many bacterial species, including a number of pathogens, in the oral environment. This study examines the influence of a variety of environmental conditions on rates of hydrogen peroxide synthesis by Streptococcus gordonii. Hydrogen peroxide was synthesized at every concentration of glucose and sucrose tested from 10 microM to 1 M, with the highest rates occurring at 0.1 mM sucrose and 1 mM glucose. S. gordonii appeared to have an intracellular store of polysaccharide which supported hydrogen peroxide formation even when the assay buffer contained no carbohydrate. Most heavy metal ions inhibited peroxidogenesis, and anaerobic conditions induced adaptive down-regulation of hydrogen peroxide synthesis; however, peroxidogenesis was generally insensitive to moderate increases in salt concentration, alteration of the mineral content of the assay solution, and changes in pH between 5.0 and 7.5. In contrast, stimulation of peroxidogenesis occurred in 1 mM Mg(2+) and 10 to 50 mM potassium L-lactate. Maximum peroxidogenesis occurred during the mid-logarithmic and late-logarithmic phases of bacterial growth. These bacterial responses may have significant implications for oral ecology and oral health.

An extracellular protease of Streptococcus gordonii hydrolyzes type IV collagen and collagen analogues.

Streptococcus gordonii is a frequent cause of infective bacterial endocarditis, but its mechanisms of virulence are not well defined. In this study, streptococcal proteases were recovered from spent chemically defined medium (CDM) and fractionated by ammonium sulfate precipitation and by ion-exchange and gel filtration column chromatography. Three proteases were distinguished by their different solubilities in ammonium sulfate and their specificities for synthetic peptides. One of the enzymes cleaved collagen analogs Gly-Pro 4-methoxy-beta-naphthylamide, 2-furanacryloyl-Leu-Gly-Pro-Ala (FALGPA), and p-phenylazobenzyloxycarbonyl-Pro-Leu-Gly-Pro-Arg (pZ-peptide) and was released from the streptococci while complexed to peptidoglycan fragments. Treatment of this protease with mutanolysin reduced its 180- to 200-kDa mass to 98 kDa without loss of enzymatic activity. The purified protease cleaved bovine gelatin, human placental type IV collagen, and the Aalpha chain of fibrinogen but not albumin, fibronectin, laminin, or myosin. Enzyme activity was inhibited by phenylmethylsulfonyl fluoride, indicating that it is a serine-type protease. Maximum production of the 98-kDa protease occurred during growth of S. gordonii CH1 in CDM containing 0.075% total amino acids at pH 7.0 with minimal aeration. Higher initial concentrations of amino acids prevented the release of the protease without reducing cell-associated enzyme levels, and the addition of an amino acid mixture to an actively secreting culture stopped further enzyme release. The purified protease was stored frozen at -20 degreesC for several months or heated at 50 degreesC for 10 min without loss of activity. These data indicate that S. gordonii produces an extracellular gelatinase/type IV collagenase during growth in medium containing minimal concentrations of free amino acids. Thus, the extracellular enzyme is a potential virulence factor in the amino acid-stringent, thrombotic, valvular lesions of bacterial endocarditis.

The relationship between teacher sign skills and student evaluations of teacher capability.

This study examines the extent to which deaf students' perceptions of their teachers' effectiveness and ease of communication in the classroom are related to the teachers' sign skills. Thirty-three faculty, teaching a variety of courses at the National Technical Institute for the Deaf (NTID), were rated on "teaching effectiveness" and "communication ease" by their students over a 2-year period. Faculty sign proficiency was evaluated independently using the Sign Communication Proficiency Interview (SCPI). Results indicate a moderate relation between students' perceptions of communication ease and teaching effectiveness, and a weak relation of these two variables to the teachers' assessed level of sign skill. The data also show that the students could clearly differentiate three levels of teacher sign skill in the classroom. Results are discussed in relation to the component parts of effective communication from the perspective of students in the classroom.

Learning styles of deaf college students and instructors' teaching emphases.

Six learning style dimensions of the Grasha-Riechmann Student Learning Style Scales (GRSLSS) were examined in this study with 100 deaf college students. In addition, six corresponding scales of teaching emphases were administered to the 16 instructors of these students. Student mean scores were higher for the dependent, participative, collaborative, and independent dimensions than for the competitive and avoidant styles. The participative learning style correlated significantly with course achievement and course interest, which suggests that an emphasis on active learning may be desirable. For instructors, as with students, the mean scores for teaching emphases were found to be higher for the collaborative, dependent, participative, and independent dimensions. the similar patterns of results for students and teachers suggest a correspondence between the learning styles and the teaching emphases.

Considerations in educating deaf and hard-of-hearing students in inclusive settings.

This article provides an overview of key issues pertinent to an inclusive approach to the education of deaf students in order to establish a context for interpreting and integrating the articles in this issue. It discusses definitions of inclusion, integration, and mainstreaming from placement-related, philosophical, and pragmatic perspectives. The article provides demographic information pertinent to an inclusive approach. It also compares perspectives on inclusion in the general field of special education with those in the education of deaf and hard-of-hearing students. It considers the challenges of using an inclusive approach to achieve academic and social integration of students, as based on research on the learning and adjustment of deaf and hard-of-hearing students in regular classes. The article concludes with an overview of the topics addressed in the issue.

Participation of deaf and hard-of-hearing students in classes with hearing students.

This project identified key issues concerning participation of deaf and hard-of-hearing (D/HH) students in regular (mainstream) classes. In one study, qualitative data were collected from 40 participants in focus groups consisting of interpreters, teachers of the deaf, and notetakers. In a second study, repeated field observations were made of four elementary-level D/HH students who were participating in small-group learning activities with hearing classmates. Focus group comments indicated that regular classroom teachers, interpreters, teachers of the deaf, hearing classmates, and D/HH students contribute to active participation by the D/HH student. Focus groups identified specific barriers that interfered with participation of each of these groups of individuals, and they also identified specific strategies to facilitate participation. Qualitative analyses of field observation data yielded results consistent with the comments collected from the focus groups participants. The observations identified accommodations that regular classroom teachers, teachers of the deaf, and interpreters can make to promote integration of the D/HH student. A summary synthesis of the data presents 16 specific strategies for overcoming barriers to participation.