Induction of pulmonary matrilysin expression by combustion and ambient air particles

The molecular mechanism(s) by which chemically complex air pollution particles mediate their adverse health effects is not known. We have examined the ability of combustion and ambient air particles to induce pulmonary matrilysin expression due to the well-documented role of matrix metalloproteinases in tissue injury and repair responses. Rats were exposed to saline, residual oil fly ash (2.5 mg/rat), or ambient air particles (2.5 mg/rat) via intratracheal instillation and examined 3-72 h after exposure. Saline-exposed animals had low levels of matrilysin mRNA, whereas the animals exposed to either complex particle showed an early induction of pulmonary matrilysin gene expression as well as of the 19-kDa activated form of matrilysin. Immunocytochemistry and in situ hybridization analyses identified the alveolar macrophages and monocytes as primary sources of air pollution particle-induced matrilysin expression. Matrilysin gene induction and protein activation by combustion and ambient air particles correlated with the early histopathological changes produced by these particles. These results demonstrate the ability of combustion and ambient air particles to induce pulmonary matrilysin expression and suggest a role for this matrix metalloproteinase in the initiation of lung injury produced by these particles.

High- and low-dose interferon alfa-2b in high-risk melanoma: first analysis of intergroup trial E1690/S9111/C9190

PURPOSE

Pivotal trial E1684 of adjuvant high-dose interferon alfa-2b (IFNalpha2b) therapy in high-risk melanoma patients demonstrated a significant relapse-free and overall survival (RFS and OS) benefit compared with observation (Obs).

PATIENTS AND METHODS

A prospective, randomized, three-arm, intergroup trial evaluated the efficacy of high-dose IFNalpha2b (HDI) for 1 year and low-dose IFNalpha2b (LDI) for 2 years versus Obs in high-risk (stage IIB and III) melanoma with RFS and OS end points.

RESULTS

A total of 642 patients were enrolled (608 patients eligible), of whom a majority (75%) had nodal metastasis (50% had nodal recurrence). Unlike E1684, E1690 allowed entry of patients with T4 (> 4 mm) deep primary tumors, regardless of nodal dissection, and 25% of the patients entered onto this trial had deep primary tumors (compared with 11% in E1684). At 52 months' median follow-up, HDI demonstrated an RFS benefit exceeding that of LDI compared with Obs. The 5-year estimated RFS rates for the HDI, LDI, and Obs arms were 44%, 40%, and 35%, respectively. The hazards ratio for the intent-to-treat analysis of HDI versus Obs was 1.28 (P(2) =.05); for LDI versus Obs, it was 1.19 (P(2) =.17). By Cox analysis, the impact of HDI on RFS achieved significance (P(2) =.03). The RFS benefit was equivalent for node-negative and node-positive patients. Neither HDI nor LDI has demonstrated an OS benefit compared with Obs at this time. A major improvement in the median OS of patients in the E1690 Obs arm was noted in comparison with E1684 (6 years v 2.8 years). An analysis of salvage therapy for patients who relapsed on E1690 demonstrated that a significantly larger proportion of patients in the Obs arm received IFNalpha-containing salvage therapy compared with the HDI arm; this therapy was unavailable to patients during E1684, and patients with undissected regional nodes were not included in E1684. This study did not specify therapy at recurrence. Analysis of treatments received at recurrence demonstrated significantly more frequent use of IFNalpha2b at relapse from Obs than from HDI, which may have confounded interpretation of the survival benefit of assigned treatments in E1690.

CONCLUSION

The results of the intergroup E1690 trial demonstrate an RFS benefit of IFNalpha2b that is dose-dependent and significant for HDI by Cox multivariable analysis.

"Wet Voice" as a predictor of penetration and aspiration in oropharyngeal dysphagia

This article describes the results of a study that investigated how well wet phonation can predict penetration and/or aspiration of ingested material in dysphagic patients. Voice samples of 23 subjects with neurologic oropharyngeal dysphagia were collected immediately after each subject had swallowed nine different boluses on videofluoroscopy. The boluses were graded according to three different consistencies and three different sizes. The presence of wetness in the voice was analyzed in relation to any ingested material that remained in the larynx or trachea after each bolus was swallowed. Results showed that there was no association between the presence of a wet voice and penetration or aspiration of prandial material after a swallow. The importance of detecting wet phonation by itself was therefore not considered diagnostic in detecting prandial penetration/aspiration by the bedside, but a wet voice may still be useful in identifying those with dysphagia who may have laryngeal dysfunction and therefore may be at risk of penetrating/aspirating any type of material, not just prandial material.

Pandora's box: physician order entry and nursing work redesign

The Canadian health care industry is undergoing unprecedented restructuring in response to the quest for quality management and cost reduction. Physician order entry and on-line results viewing within a fully integrated hospital clinical information system is often thought to be essential to maximum quality management, cost control, and clinical decision support. Using Hackman and Oldham's Job Characteristics model (1989) as a grounding for discussion, this author examines the impact of computerized physician order entry and on-line results viewing on the intrinsic meaning of nursing work and its subsequent redesign. This paper explores the historical meaning of nursing work related to the manual transcription of physician's orders, and contemplates the implications for future nursing work and research. Until now there has been little discussion in the current informatics literature on this topic.

Prediction of bone strength of distal forearm using radius bone mineral density and phalangeal speed of sound

This investigation compares quantitative ultrasound (QUS) measurement of the phalanges with peripheral quantitative computed tomography (pQCT) and dual X-ray absorptiometry (DXA) measurement of the forearm, to estimate the strength of the distal radius in 13 cadaveric forearms. The cadavers were scanned at the distal radius by pQCT and DXA for bone mineral density (BMD) and at the approximate phalanges by QUS for speed of sound (SOS). The distal radii were subjected to a simulated Colles fracture produced with a materials testing machine. The load at which the distal radius was fractured was considered as a representation of bone strength. The bone strength correlated significantly with SOS at different phalanges (r = 0.63-0.72), BMD at different regions of interest by DXA (r = 0.67-0.75), and cortical BMD at different sites by pQCT (r = 0.61-0.67). Standard stepwise regression analysis showed that adding phalangeal SOS into forearm densitometric variables significantly enhanced the statistical power for prediction of the strength of the distal radius. Our results suggest that, for assessment of site-specific distal forearm strength, QUS measurement of the phalanges is comparable to forearm densitometry. Phalangeal QUS may add clinical value if distal forearm strength has a high priority.

Variable pulmonary responses from exposure to concentrated ambient air particles in a rat model of bronchitis

Chronic bronchitis may be considered a risk factor in particulate matter (PM)-induced morbidity. We hypothesized that a rat model of human bronchitis would be more susceptible to the pulmonary effects of concentrated ambient particles (CAPs) from Research Triangle Park, NC. Bronchitis was induced in male Sprague-Dawley rats (90-100 days of age) by exposure to 200 ppm sulfur dioxide (SO2), 6 h/day x 5 days/week x 6 weeks. One day following the last SO2 exposure, both healthy (air-exposed) and bronchitic (SO2-exposed) rats were exposed to filtered air (three healthy; four bronchitic) or CAPs (five healthy; four bronchitic) by whole-body inhalation, 6 h/day x 2 or 3 days. Pulmonary injury was determined either immediately (0h) or 18 h following final CAPs exposure. The study protocol involving 0 h time point was repeated four times (study #A, November, 1997; #B, February, 1998; #C and #D, May, 1998), whereas the study protocol involving 18 h time point was done only once (#F). In an additional study (#E), rats were exposed to residual oil fly ash (ROFA), approximately 1 mg/ m(3)x6 h/day x 3 days to mimic the CAPs protocol (February, 1998). The rats allowed 18 h recovery following CAPs exposure (#F) did not depict any CAPs-related differences in bronchoalveolar lavage fluid (BALF) injury markers. Of the four CAPs studies conducted (0 h time point), the first (#A) study (approximately 650 microg/m3 CAPs) revealed significant changes in the lungs of CAPs-exposed bronchitic rats compared to the clean air controls. These rats had increased BALF protein, albumin, N-acetyl glutaminidase (NAG) activity and neutrophils. The second (#B) study (approximately 475 microg/m3 CAPs) did not reveal any significant effects of CAPs on BALF parameters. Study protocols #C (approximately 869 microg/m3 CAPs) and #D (approximately 907 microg/m3 CAPs) revealed only moderate increases in the above mentioned BALF parameters in bronchitic rats exposed to CAPs. Pulmonary histologic evaluation of studies #A, #C, #D, and #F revealed marginally higher congestion and perivascular cellularity in CAPs-exposed bronchitic rats. Healthy and bronchitic rats exposed to ROFA (approximately 1 mg/m3) did not show significant pulmonary injury (#E). Analysis of leachable elemental components of CAPs revealed the presence of sulfur, zinc, manganese, and iron. There was an apparent lack of association between pulmonary injury and CAPs concentration, or its leachable sulfate or elemental content. In summary, real-time atmospheric PM may result in pulmonary injury, particularly in susceptible models. However, the variability observed in pulmonary responses to CAPs emphasizes the need to conduct repeated studies, perhaps in relation to the season, as composition of CAPs may vary. Additionally, potential variability in pathology of induced bronchitis or other lung disease may decrease the ability to distinguish toxic injury due to PM.

The efficacy of tone-reducing features in orthotics on the gait of children with spastic diplegic cerebral palsy

This study analyzed the effects of tone-reducing features in ankle-foot orthotics (AFOs) on the gait of eight children (ages 4-11 years) with spastic diplegic cerebral palsy. A standard gait analysis was performed on each subject in each of three trial orthotics and in a baseline shoes-only condition. A 4-week accommodation period was allotted for each of the three devices: a standard hinged AFO, an AFO with tone-reducing features, and a supramalleolar orthotic with tone-reducing features. Most significant differences were at the ankle, between free-ankle and plantar flexion-limiting conditions. No significant functional changes in gait were evident with the addition of tone-reducing properties to a standard articulating AFO.

Implications of Working Time Regulations for theatre nurses working in the NHS

The European Working Times Regulations have implications for staff throughout the NHS. In particular, theatre staff and others working on call and shifts need to be aware of the implications of these regulations. In this article, Jon Richards, National Officer for Unison, explains the background to and implications of these regulations for theatre staff.

Validity and reliability of a kinematic protocol for determining foot contact events

Timing of foot contact events provides important information for gait studies. The aim of the study is to validate the use of kinematic data, collected at 50 Hz to define foot contact events during gait initiation. Simultaneous kinetic and kinematic data recordings of four discrete foot contact events were made for normal adults. Raters were asked to estimate the timing of the events from kinematic data curves and these timings were compared with those derived from the kinetic data. For the four events, between 88 and 98% of all ratings were accurate to within 0.03 s. Inter-rater reliability was extremely high, reflecting the precision of the definitions used.

Comparison of surface mounted markers and attachment methods in estimating tibial rotations during walking: an in vivo study

The overall goal of this work was to determine an optimal surface-tracking marker set for tracking motion of the tibia during natural cadence walking. Eleven different marker sets were evaluated. The marker sets differed in the location they were attached to the shank, the method used to attach the marker sets to the segment and the physical characteristics of the marker sets. Angular position during stance for each marker set was expressed relative to the orientation of the tibia as measured using bone anchored markers. A marker set consisting of four markers attached to a rigid shell positioned over the distal lateral shank and attached to the leg using an underwrap attachment yielded the best estimate of tibial rotation. Rotational deviations of+/-2 degrees about the medio-lateral and antero-posterior axes, and+/-4 degrees about the longitudinal axis did occur even when using the optimal set of markers.

Evaluation of phototoxic potential of gemifloxacin in healthy volunteers compared with ciprofloxacin

This double-blind, randomized, parallel-group comparative study investigated the phototoxic potential of gemifloxacin mesylate, a potent, novel fluoroquinolone antimicrobial. Forty healthy male and female volunteers received repeat dosing for 7 days with 160 mg or 320 mg of gemifloxacin (o.d., p.m.), 500 mg of ciprofloxacin (b.d.) or placebo (b.d.). On day 5 (large step) and day 6 (small step), graded series of wavebands were irradiated onto the back of each volunteer (phototesting). Skin reactions were assessed 0-30 min (immediate erythema) and 24 and 48 h (delayed erythema) after irradiation. Both gemifloxacin, 320 mg o.d., and ciprofloxacin, 500 mg b.d., were associated with mild phototoxicity following 7 days of administration. The range of mean phototoxic indices (the ratio of minimal erythemal dose at baseline compared with that on day 7 at the end of dosing) was 1.00-2.19 for gemifloxacin and 0.97-2.23 for ciprofloxacin. The abnormal responses occurred within the ultraviolet A region (335-365 +/-30 nm) and were maximal at 24 h. Susceptibility to phototoxicity had cleared 48 h after stopping the drug. The phototoxicity observed with gemifloxacin, 160 mg o.d., was lower than that at the higher dose and similar to that of placebo, suggesting that gemifloxacin phototoxicity is dose dependent. There were no clinically important changes in the safety profiles of gemifloxacin and ciprofloxacin compared with placebo in healthy volunteers after 7 days of repeat dosing. This study demonstrated that gemifloxacin, 320 mg o.d. given for 7 days, has a low potential to cause mild photosensitivity which is similar to that of ciprofloxacin, 500 mg b.d., given for the same period.

The effect of alpha2-delta and other accessory subunits on expression and properties of the calcium channel alpha1G

1. The effect has been examined of the accessory alpha2-delta and beta subunits on the properties of alpha1G currents expressed in monkey COS-7 cells and Xenopus oocytes. 2. In immunocytochemical experiments, the co-expression of alpha2-delta increased plasma membrane localization of expressed alpha1G and conversely, the heterologous expression of alpha1G increased immunostaining for endogenous alpha2-delta, suggesting an interaction between the two subunits. 3. Heterologous expression of alpha2-delta together with alpha1G in COS-7 cells increased the amplitude of expressed alpha1G currents by about 2-fold. This finding was confirmed in the Xenopus oocyte expression system. The truncated delta construct did not increase alpha1G current amplitude, or increase its plasma membrane expression. This indicates that it is the exofacial alpha2 domain that is involved in the enhancement by alpha2-delta. 4. Beta1b also produced an increase of functional expression of alpha1G, either in the absence or the presence of heterologously expressed alpha2-delta, whereas the other beta subunits had much smaller effects. 5. None of the accessory subunits had any marked influence on the voltage dependence or kinetics of the expressed alpha1G currents. These results therefore suggest that alpha2-delta and beta1b interact with alpha1G to increase trafficking of, or stabilize, functional alpha1G channels expressed at the plasma membrane.

Juvenile X-linked retinoschisis from XLRS1 Arg213Trp mutation with preservation of the electroretinogram scotopic b-wave

PURPOSE

To present an Arg213Trp missense mutation in the XLRS1 gene in a family with juvenile X-linked retinoschisis in which one affected male had a normal electroretinogram scotopic b-wave amplitude.

METHODS

Two affected males and one unaffected male from this family with X-linked retinoschisis underwent standard clinical examination including an electroretinogram. Mutations in the XLRS1 gene were detected by sequence analysis and by restriction enzyme assay for loss of an MSP-I restriction site.

RESULTS

A missense mutation of C to T at nucleotide position 637 was identified in exon 6 of the XLRS1 gene. This changed the positively charged arginine to a nonpolar tryptophan (Arg213Trp) within the biologically important discoidin domain. Clinical examination revealed intraretinal cysts in a spoke-wheel distribution and early macular atrophy of the retinal pigment epithelium. Whereas the older affected patient had an "electronegative" electroretinogram typical of retinoschisis, the 13-year-old grandson with the same XLRS1 mutation had a normal electroretinogram scotopic b-wave.

CONCLUSION

Although the electroretinogram is a key diagnostic test for X-linked retinoschisis, this report of a normal electroretinogram scotopic b-wave in a male with molecularly confirmed X-linked retinoschisis indicates that caution is advised in relying on the electroretinogram in differential diagnosis of this condition.

Phase I evaluation of humanized OKT3: toxicity and immunomodulatory effects of hOKT3gamma4

Murine anti-CD3 (OKT3, Muromonab-CD3) is a potent human T-lymphocyte mitogen. A previous clinical Phase I trial examined OKT3 as an immunomodulator for the treatment of cancer. However, the murine monoclonal antibody triggered a potent humoral response that neutralized the antibody activity during subsequent administration. Thus, a "humanized" form of OKT3 (hOKT3gamma4) was developed to minimize immunogenicity. The genetically engineered human anti-CD3 retained its binding activity and effectively activated T cells in vitro. Therefore, we evaluated the safety and activity of hOKT3gamma4 in a Phase I clinical trial. hOKT3gamma4 was administered as a 10-min i.v. infusion every 2 weeks for three injections (one course of therapy). Six dose levels ranging from 50 to 1600 microg/injection were evaluated. Headache and fever were common, transient toxicities but were not dose limiting. The dose-limiting toxicities were rigors and dyspnea at the 1600-microg dose level, which defined 800 microg as the maximally tolerated dose in this trial. A dose-dependent in vivo T-lymphocyte activation was produced by this treatment, and the most significant T-lymphocyte activation occurred in patients treated at the two highest dose levels (800 and 1600 microg). Persistent CD3 modulation occurred after administration of 1600 microg of hOKT3gamma4. Anti-idiotypic antibodies were detected in only 6 of 24 patients after multiple injections and were not associated with attenuation of T-lymphocyte activation. Malignant ascites resolved in three patients, one each with peritoneal mesothelioma, pancreatic adenocarcinoma, and ovarian adenocarcinoma. hOKT3gamma4 can induce T-lymphocyte activation in patients with cancer, and the immunogenicity of the "humanized" antibody is sufficiently reduced relative to its murine "parent" to permit immunostimulation by repetitive i.v. administration. The therapeutic potential of biweekly i.v. hOKT3gamma4 at a dose of 800 microg should be further evaluated.

Family-oriented care during pediatric inter-hospital transport

We evaluated the family-oriented care and counseling provided by the BC Children's Hospital Transport Team paramedies. One hundred families were asked to rate: (1) how they would like paramedies to communicate with them under ideal conditions; and (2) what they actually experienced during their child's transport. There were no significant differences in parents' preferences under ideal circumstances and what they actually experienced in five of nine behavioural areas studied. Nineteen paramedies also rated their use of elements of family-oriented communication and the strategies they would recommend other teams use when interacting with families. The elements that paramedies reported using most frequently were rated highly by parents and produced positive feelings in the majority of families. The study indicates that effective counseling can be achieved in 'critical', time-limited situations but improvements can be made; and it supports the value of appropriate selection and training of transport team personnel in family-oriented critical care.

Multimedia to teach urology to medical students

OBJECTIVES

To test the hypothesis that an interactive multimedia-based computer application may be used to teach urology to undergraduate medical students.

METHODS

Third-year medical students rotating on their urology clerkship were studied. Student knowledge was measured with a multiple choice test administered in a pretest-post-test experimental design. The educational intervention was a multimedia-based application that presented a clinical module on hematuria, using natural language-like entries. Student attitudes toward the multimedia application were assessed by a survey.

RESULTS

Twenty-three consecutive third-year medical students participated. Mean pretest and post-test scores +/- standard deviation were 35%+/-11% versus 74%+/-17%, respectively, P<0.0001. Student questionnaire responses indicated highly positive opinions that the multimedia-based module was easy to use, was fun, provided natural patient responses, had clear exercises, provided immediate feedback, was educational, and had a nonthreatening format, and that the multiple choice questions were clear and fair.

CONCLUSIONS

Multimedia-based education may be used to teach urology to undergraduate medical students.