Teaching and learning about chronic conditions management for undergraduate medical students: utilizing the patient-as-teacher approach

OBJECTIVES

This study was undertaken to evaluate the impact on medical student learning of a revised chronic conditions teaching programme based on the chronic care model utilizing patients-as-teachers.

METHODS

A qualitative questionnaire was completed by students at the start of a primary healthcare rotation to determine existing impressions/understandings about chronic conditions. Following the revised teaching programme, a reflective essay about a home-visit to a person with chronic conditions was completed by students at the end of the rotation.

RESULTS

Analysis of the questionnaire at the start of the rotation showed students have some knowledge of the differences between acute and chronic care, have rather negative impressions of what it means to have chronic conditions and know little of overall patient management including the work of an interdisciplinary team. Analysis of the reflective essays completed by students at the end of the rotation showed an increased understanding of chronic conditions, what it means to have a chronic condition and who supports management.

DISCUSSION

A structured chronic conditions teaching programme including patient-as-teacher is an effective way of building knowledge and changing students' impressions of what it means to have a chronic condition.

Atrophy of the lateral geniculate nucleus in human glaucoma detected by magnetic resonance imaging

Aim:

To determine in vivo whether the lateral geniculate nucleus (LGN) undergoes atrophy in patients with glaucoma and vision loss compared with normal subjects.

Methods:

Following institutional St Michael’s Hospital Research Ethics Board approval, a prospective and masked neuroimaging study was conducted on glaucoma patients with visual-field defects affecting both eyes (n = 10) and age-matched controls (n = 8). Following informed consent, all subjects underwent 1.5-Tesla MRI. Coronal proton density magnetic resonance images of both LGNs were obtained, and LGN height measurements were measured by consensus by three neuroradiologists masked to the diagnosis. Glaucoma and control groups were compared using the t test.

Results:

Both LGNs were identified and visualised by 1.5-Tesla MRI for every subject. Compared with controls, the mean LGN heights in glaucoma were decreased in right (4.09 (0.89) mm vs 4.74 (0.54) mm, p>0.05) and left LGNs (3.98 (0.57) mm vs 4.83 (0.95) mm; p = 0.033). The combined right and left LGN height in glaucoma was significantly decreased compared with controls (8.07 (1.06) mm vs 9.56 (0.86) mm; p = 0.005).

Conclusion:

In vivo MRI evidence of LGN degeneration in human glaucoma is consistent with ex vivo primate and human neuropathological studies. LGN atrophy may be a relevant biomarker of visual system injury and/or progression in some glaucoma patients.

Lipophilic fluorochrome trackers of membrane transfers between immune cells

Cell-to-cell transfers of membrane molecules between lymphoid cells (sometimes referred to as trogocytosis) is frequent and has multiple physiological consequences. Although difficult to visualize through the tracking of defined cell surface proteins, this process can be readily monitored by inserting PKH or CellVue Maroon fluorochromes into the plasma membranes of donor cells. We discuss here parameters that determine its detection by a flow-cytometry-based in vitro assay and present examples of application, including time-lapse video-microscopy analysis of transfers at the immunological synapse. By combining detection of cell-to-cell transfer and of cell surface CD107, it is possible to discriminate lymphoid cells binding target cells with and without perforin release. This could prove useful for identifying cells that destruct known target cells in autoimmune pathologies.

Long-distance three-color neuronal tracing in fixed tissue using NeuroVue dyes

Dissecting development of neuronal connections is critical for understanding neuronal function in both normal and diseased states. Charting the development of the multitude of connections is a monumental task, since a given neuron typically receives hundreds of convergent inputs from other neurons and provides divergent outputs for hundreds of other neurons. Although progress is being made utilizing various mutants and/or genetic constructs expressing fluorescent proteins like GFP, substantial work remains before a database documenting the development and final location of the neuronal pathways in an adult animal is completed. The vast majority of developing neurons cannot be specifically labeled with antibodies and making specific GFP-expressing constructs to tag each of them is an overwhelming task. Fortunately, fluorescent lipophilic dyes have emerged as very useful tools to systematically compare changes in neuronal networks between wild-type and mutant mice. These dyes diffuse laterally along nerve cell membranes in fixed preparations, allowing tracing of the position of a given neuron within the neuronal network in murine mutants fixed at various stages of development. Until recently, however, most evaluations have been limited to one, or at most, two color analyses. We have previously reported three color neuronal profiling using the novel lipophilic dyes NeuroVue (NV) Green, Red and Maroon (Fritzsch et al., Brain. Res. Bull. 66: 249-258, 2005). Unfortunately such three color experiments have been limited by the fact that NV Green and its brighter successor, NV Emerald, both exhibit substantially decreased signal intensities when times greater than 48 hours at 37 degrees C are required to achieve neuronal profile filling (unpublished observations). Here we describe a standardized test system developed to allow comparison of candidate dyes and its use to evaluate a series of 488 nm-excited green-emitting lipophilic dyes. The best of these, NV Jade, has spectral properties well matched to NV Red and NV Maroon, better solubility in DMF than DiO or DiA, improved thermostability compared with NV Emerald, and the ability to fill neuronal profiles at rates of 1 mm per day for periods of at least 5 days. Use of NV Jade in combination with NV Red and NV Maroon substantially improves the efficiency of connectional analysis in complex mutants and transgenic models where limited numbers of specimens are available.

The efficiency of ozonated water from a water treatment plant to inactivate Cryptosporidium oocysts during two seasonal temperatures

We investigated the efficiency of residual ozone from an advanced water treatment plant with an applied dose of 2.5 mg l(-1) to inactivate viable Cryptosporidium oocysts during summer (i.e. 24 degrees C) and winter (i.e. 18.9 degrees C) in Queensland, Australia. Containers for sample collection were inoculated with 1,000 oocysts l(-1) and filled with ozonated water. Ozone residual concentrations were measured at 0, 5 and 10 min intervals. Viability was determined by excystation. Non-ozonated water from the plant, trip and laboratory controls were also analysed. The applied ozone dose of 2.5 mg l(-1) produced an immediate residual concentration of 1.25 mg 1(-1) at 24 degrees C and 1.34 mg 1(-1) at 18.9 degrees C in unseeded samples. The initial ozone residual in seeded containers was 1.22+/-0.03 mg 1(-1) at 24 degrees C and 1.37+/-0.04 mg 1(-1) at 18.9 degrees C. There was a gradual increase in inactivation of oocysts, with 49% of oocysts inactivated at 0 min to 92% after 10 min at 24 degrees C and 57% at 0 min to 92.8% at 10 min at 18.9 degrees C.

Evaluation of an alternative method for the enumeration and confirmation of Clostridium perfringens from treated and untreated sewages

AIMS

Clostridium perfringens is recommended as a suitable indicator bacterium for human enteric viruses, Giardia cysts and Cryptosporidium oocysts in finished water and in the assessment and evaluation of water treatment. Several agars and confirmation procedures were evaluated in parallel with the Australian/New Zealand Standard (AS/NZ) Method for the enumeration of Cl. perfringens from treated and untreated sewage samples.

METHODS AND RESULTS

The current AS/NZ method utilizes tryptose sulfite cycloserine agar (TSC), lactose gelatin medium (LG) and nitrate motility medium (NM) at an incubation temperature of 37 degrees C. Sixty treated and untreated sewage samples were used to evaluate TSC agar, membrane Cl. perfringens agar (mCP), Perfringens agar (OPSP) and Perfringens agar with 4-methylumbelliferyl phosphate (OPSP-MUP) for enumeration of Clostridium. An incubation temperature of 44 degrees C for 24 h was used for comparison. Confirmation procedures were also evaluated using 103 isolates and included LG and NM, ortho-nitrophenyl-beta-D-galactopyranoside (ONPG) with MUP (ONPG-MUP) and phosphatase reagent (PR). OPSP compared favourably with TSC agar. One false negative result was obtained from each of the LG/NM and ONPG-MUP procedures. No false results were obtained using the PR confirmation procedure.

CONCLUSIONS

OPSP agar and PR were determined as suitable replacements for the AS/NZ Standard procedure with no interference from spreading organisms.

SIGNIFICANCE AND IMPACT OF THE STUDY

This is a simple and rapid method for isolating and enumerating Cl. perfringens from sewage samples and confirmed results can be reported more quickly due to shorter analytical turnaround times.

Flow cytometer in the infrared: Inexpensive modifications to a commercial instrument

BACKGROUND

The application of molecules that fluoresce in the infrared (IR) region to measure cell products would be enhanced by a flow cytometer capable of measuring them. To our knowledge, none exist at this time. Accordingly, we have developed such an instrument.

METHODS

A Becton Dickinson LSR flow cytometer was modified to include a small 785-nm IR diode laser the size of a C cell battery with 44-mW output power. The instrument was modified further to accommodate this laser in addition to a 405-nm solid-state laser, a 488-nm air-cooled argon laser, and a 658-nm solid-state laser. Because the IR laser is dangerous to the eye, the laser beams were viewed for optical alignment using a CCD camera and video monitor. An avalanche photodiode was used in place of a photomultiplier tube because its detection sensitivity in the IR region is superior.

RESULTS

To assess performance, scatter and fluorescence measurements were made using microspheres that fluoresce in the IR region, and human leukocytes were stained with CD45 biotin followed by a streptavidin conjugated with an IR dye. An avalanche photodiode was 2.3 to 2.8 times more sensitive than a photomultiplier tube for detecting IR fluorescence. Cells stained with CD45 biotin and avidin conjugated with an IR dye could easily be resolved and their fluorescence quantified; there was virtually no autofluorescence. In addition, a lipophilic membrane dye that emits in the IR region was studied. HL60 cells were stained with this dye and they exhibited bright fluorescence intensity.

CONCLUSION

A commercial instrument could be modified to accommodate an IR laser for exciting dyes that fluoresce in the IR region. This new capability will extend the range of fluorescence that can be measured by flow cytometry.

Evaluation of five membrane filtration methods for recovery of Cryptosporidium and Giardia isolates from water samples

We evaluated the efficiency of five membrane filters for recovery of Cryptosporidium parvum oocysts and Giardia lamblia cysts. These filters included the Pall Life Sciences Envirochek (EC) standard filtration and Envirochek high-volume (EC-HV) membrane filters, the Millipore flatbed membrane filter, the Sartorius flatbed membrane filter (SMF), and the Filta-Max (FM) depth filter. Distilled and surface water samples were spiked with 10 oocysts and 10 cysts/liter. We also evaluated the recovery efficiency of the EC and EC-HV filters after a 5-s backwash postfiltration. The backwashing was not applied to the other filtration methods because of the design of the filters. Oocysts and cysts were visualized by using a fluorescent monoclonal antibody staining technique. For distilled water, the highest percent recovery for both the oocysts and cysts was obtained with the FM depth filter. However, when a 5-s backwash was applied, the EC-HV membrane filter (EC-HV-R) was superior to other filters for recovery of both oocysts (n = 53 +/- 15.4 per 10 liters) and cysts (n = 59 +/- 11.5 per 10 liters). This was followed by results of the FM depth filter (oocysts, 28.2 +/- 8, P = 0.015; cysts, 49.8 +/- 12.2, P = 0.4260), and SMF (oocysts, 16.2 +/- 2.8, P = 0.0079; cysts, 35.2 +/- 3, P = 0.0079). Similar results were obtained with surface water samples. Giardia cysts were recovered at higher rates than were Cryptosporidium oocysts with all five filters, regardless of backwashing. Although the time differences for completion of filtration process were not significantly different among the procedures, the EC-HV filtration with 5-s backwash was less labor demanding.

Trace elements in moose (Alces alces) found dead in Northwestern Minnesota, USA

The moose (Alces alces) population in bog and forest areas of Northwestern Minnesota has declined for more than 25 years, and more recently the decline is throughout Northwestern Minnesota. Both deficiencies and elevations in trace elements have been linked to the health of moose worldwide. The objective of this study was to evaluate whether trace element toxicity or deficiency may have contributed to the decline of moose in Northwestern Minnesota. Livers of 81 moose found dead in Northwestern Minnesota in 1998 and 1999 were analyzed for trace elements. With the exception of selenium (Se) and copper (Cu), trace elements were not at toxic or deficient levels based on criteria set for cattle. Selenium concentrations in moose livers based on criteria set for cattle were deficient in 3.7% of livers and at a chronic toxicity level in 16% of livers. Copper concentrations based on criteria set for cattle were deficient in 39.5% of livers, marginally deficient in 29.5% of livers and adequate in 31% of livers. Moose from agricultural areas had higher concentrations, on average, of Cd, Cu, Mo and Se in their livers than moose from bog and forest areas. Older moose had higher concentrations of Cd and Zn, and lower concentrations of Cu than younger moose. Copper deficiency, which has been associated with population declines of moose in Alaska and Sweden, may be a factor contributing to the decline of moose in Northwestern Minnesota.

Inhalation efficacy of RFI-641 in an African green monkey model of RSV infection

Human respiratory syncytial virus (RSV) is a major cause of acute upper and lower respiratory tract infections. RFI-641 is a novel RSV fusion inhibitor with potent in vitro activity. In vivo efficacy of RFI was determined in an African green monkey model of RSV infection involving prophylactic and therapeutic administration by inhalation exposure. Inhalation was with an RFI-641 nebulizer reservoir concentration of 15 mg/ml for 15 minutes (short exposure) or 2 hours (long exposure). Efficacy and RFI-641 exposure was determined by collection of throat swabs, nasal washes and bronchial alveolar lavage (BAL) on selected days. The short-exposure group (15 minutes) exhibited no effect on the nasal, throat or BAL samples. The throat and nasal samples for the long-exposure group failed to show a consistent reduction in viral titers. RFI-641 2 hours exposure-treated monkeys showed a statistically significantly log reduction for BAL samples of 0.73-1.34 PFU/ml (P-value 0.003) over all the sampling days. Analysis indicates that the long-exposure group titer was lower than the control titer on day 7 and when averaged across days. The results of this study demonstrate the ability of RFI-641 to reduce the viral load of RSV after inhalation exposure in the primate model of respiratory infection.

Routine cytogenetic and FISH studies for 17p11/15q11 duplications and subtelomeric rearrangement studies in children with autism spectrum disorders

To assess the frequency of cytogenetic abnormalities in children with autism spectrum disorders (ASDs), routine G-banded cytogenetic analyses and FISH studies to rule out 15q11.2 and 17p11.2 duplications were performed on 49 children with ASDs. Blood samples were further studied using a complete set of subtelomeric FISH probes. Routine chromosome study showed that one child had a small duplication of chromosome 5: 46,XY,dup(5)(p?14.2p?15.1). Another child had an interstitial duplication of the Prader-Willi and Angelman syndrome critical region of chromosome 15, detected by FISH analysis. The detection of these two cases underscores the importance of obtaining routine chromosome and 15q11-q13 FISH analyses in children with ASDs. No instance of 17p11.2 duplication was observed. Subtelomeric analysis did not reveal abnormalities in any of the subjects.

Condom use and partner characteristics among young adult males in urban Ghana, aged 15-24

Addressing male sexual behavior and condom use is a high priority for adolescent health programs. Using the 1997 Ghana Psychographic Survey, the aim of this study is to explore the factors related to current, partner-specific condom use, by Ghanaian males aged 15-24 years. A multivariate regression analysis reveals an independent association between psychographic attitudes, peer network characteristics, sexual partner characteristics, and some level of condom use with a nominated sexual partner. The most important predictor for both condom use consistently as well as condom use at least sometimes was respondents' knowing someone who died as a result of AIDS. This finding suggests that future interventions should aim to personalize the risk of HIV/STIs, promote condom use with a range of partner types, and educate youth about the importance of consistent use.

Mobilizing for pedestrian safety: an experiment in community action

In contrast to the steady reduction in mortality and morbidity from collisions involving motor vehicle occupants, relatively little progress has been made in controlling motor vehicle/pedestrian collisions. Engineering modifications are the most effective means of reducing such collisions, but mainly because of their cost, and public apathy about pedestrian safety, are too rarely employed. A modest experiment in community action was undertaken by attempting to induce the authorities of 10 small cities to apply for state funds to create a single model pedestrian refuge in their respective communities. Our hope was that this model would later lead to more widespread improvements. The key elements of the campaign were organizing local pedestrian safety task forces, compiling local pedestrian injury statistics, and publicizing the stories of pedestrian injury victims. At the conclusion of the planning process, all 10 target communities submitted grant applications and all 10 received full grant funding. Five projects were completed as planned, two are under construction, and the plans for three were abandoned. Pedestrian safety is not an issue that captures public attention. To make progress, goals must be modest, and a dedicated constituency must be developed. "Victim advocacy" is a vital part of this process. Progress in injury control requires concerted community action.

Randomised trial of SIR-Spheres plus chemotherapy vs. chemotherapy alone for treating patients with liver metastases from primary large bowel cancer

PURPOSE

SIR-Spheres are radioactive yttrium90 microspheres (SIR-Spheres, Sirtex Medical Limited, Australia) used to selectively target high levels of ionising radiation to tumors within the liver. This trial was designed to measure any increased patient benefit by adding a single administration of SIR-Spheres to a regimen of regional hepatic artery chemotherapy (HAC) administered as a 12 day infusion of floxuridine and repeated at monthly intervals, vs. the same chemotherapy alone.

PATIENTS AND METHODS

A phase III randomised clinical trial entering 74 patients was undertaken on patients with bi-lobar non-resectable liver metastases from primary adenocarcinoma of the large bowel. Patient benefit criteria assessed in the trial were tumor response, time to disease progression in the liver, overall survival, quality of life, and treatment related toxicity. Tumor response was measured by serial changes in both cross-sectional tumor areas and total tumor volumes, provided any response lasted not less than three months as well as changes in serum carcino-embryonic antigen (CEA).

RESULTS

The partial and complete response rate (PR + CR) was significantly greater for patients receiving SIR-Spheres when measured by tumor areas (44%) vs. 17.6%, P = 0.01) tumor volumes (50% vs. 24%, P = 0.03) and CEA (72% vs. 47%, P = 0.004). The median time to disease progression in the liver was significantly longer for patients receiving SIR-Spheres in comparison to patients receiving HAC alone when measured by either tumor areas (9.7 vs. 15.9 months, P = 0.001), tumor volumes (7.6 vs. 12.0 months, P = 0.04) or CEA (5.7 vs. 6.7 months, P = 0.06). The one, two, three and five-year survival for patients receiving SIR-Spheres was 72%, 39%, 17% and 3.5%, compared to 68%, 29%, 6.5% and 0% for HAC alone. Cox regression analysis suggests an improvement in survival for patients treated with SIR-Spheres who survive more than 15 months (P = 0.06). There was no increase in grade 3-4 treatment related toxicity and no loss of quality of life for patients receiving SIR-Spheres in comparison to patients receiving HAC alone.

CONCLUSION

The combination of a single injection of SIR-Spheres plus HAC is substantially more effective in increasing tumor responses and progression free survival than the same regimen of HAC alone.

Do Medicaid physician fees for prenatal services affect birth outcomes?

This study exploits a natural experiment to examine the relationship between Medicaid physician fees and birth outcomes among a national sample of pregnant women. Applying a cohort difference-in-differences methodology, I find a significant negative association between these fees and the risk of low birth weight. I estimate that a 10% higher than average relative Medicaid fee is independently associated with a 0.074% lower absolute risk of low birth weight (<2.5 kg) and a 0.035% lower risk of very low birth weight (<1.5kg) among Medicaid-insured women. For low-income women, this association grows significantly. Lastly, I find a moderate association between these fees and use of first trimester prenatal services.

Reassessing the concept of emotional labour in student nurse education: role of link lecturers and mentors in a time of change

This article describes part of a follow-up study to Smith's (1992) original work on emotional labour, at a time when questions of the role, scope and crisis in nursing are a matter of local and national debate (Bradshaw 1999, Gillan 1999, Fabricius 1999, Feldman et al. 1999). The article addresses recent changes in nursing and nurse education (UKCC 1986, UKCC 1999a, DoH 1999, UKCC 1999b) as a means of exploring new patterns of learning to care in nursing. Less than a decade ago, emotional labour and helping students learn to care was part of the role of the sister/charge nurse (Ogier 1982, Fretwell 1982, Smith 1992). In this study, the role of the link lecturer, and mentor who currently shape the student nurse's learning experience, is the focus for evaluation.

Rheolytic thrombectomy in the management of acute and subacute limb-threatening ischemia

PURPOSE

To evaluate the use of a percutaneous mechanical thrombectomy (PMT) catheter (AngioJet) as an initial treatment for acute (<2 weeks) and subacute (2 weeks to 4 months) arterial occlusion of the limbs.

MATERIALS AND METHODS

A total of 86 (acute, n = 65; subacute, n = 21) patients were available for retrospective analysis, averaging 65 +/- 14 years of age. Outcomes assessed include initial angiographic success (failure = less than 50% luminal restoration [LR]; partial success = 50%-95% LR; success = more than 95% LR), pre- and postprocedural ankle-brachial index (ABI), device-related and systemic complications, 1-month amputation, mortality, and short-term patency.

RESULTS

Angiographic success was evaluated in 83 of 86 patients (guide wire unable to traverse lesion in three patients). The procedure failed in 13 of 83 (15.6%) patients, partial success was seen in 19 of 83 patients (22.9%), and successful recanalization was noted in 51 of 83 patients (61.4%). Adjunctive thrombolysis was used in 50 of 86 patients (58%). However, thrombolysis resulted in angiographic improvement at the site of PMT in only seven of 50 of these patients (14%). Adjunctive thrombolysis was uniformly unsuccessful in patients in whom initial PMT failed. The median increase in ABI was 0.64 (95% CI: 0.43-0.81). Success was more likely in the setting of in situ thrombosis, with 61 of 68 (90%) procedures successful, compared to embolic occlusions, with nine of 15 (60%) procedures successful (P =.011). Angiographic outcome was not dependent on the duration of occlusion (acute, 51 of 62; subacute, 19 of 21; P =.35) or the conduit type (graft, 28 of 31; native vessel, 42 of 52; P =.35). An underlying stenosis was identified in 53 of the 70 patients (75.7%) with a successful PMT, and 51 of these 53 unmasked lesions were successfully treated. Follow-up data were available in 56 patients for patency assessment at a median of 3.9 months (range, 0.1-28.5 months). Patency at 6 months was 79% (95% CI: 65-92). Systemic complications occurred in 16.3% of patients, local complications were noted in 18.6%, and 1-month amputation and mortality rates were 11.6% and 9.3%, respectively.

CONCLUSION

PMT offers the potential to rapidly reestablish flow to an ischemic extremity and may be the only available treatment option in patients at high risk for open surgery or with contraindications to pharmacologic thrombolysis.

Percutaneous AngioJet thrombectomy in the management of extensive deep venous thrombosis

PURPOSE

This study was undertaken to evaluate the efficacy of a percutaneous mechanical thrombectomy (PMT) device for rapid thrombus removal following deep venous thrombosis (DVT).

MATERIALS AND METHODS

Over a 37-month period, 17 patients (14 women; mean age, 41 y +/- 20) with extensive DVT were treated with initial attempts at PMT with use of the AngioJet rheolytic thrombectomy device. Sites of venous thrombosis included lower extremities in 14 patients and upper extremity and brachiocephalic veins in three. The etiology for venous thrombosis was malignancy in seven, idiopathic etiology in three, May-Thurner syndrome and immobilization in three each, and oral contraceptive use and hypercoagulable disorder in one each. The primary endpoint was venographic evidence of thrombus extraction. Perioperative complications, mortality, and recurrence-free survival were also evaluated.

RESULTS

After PMT, four of 17 patients (24%) had venographic evidence of >90% thrombus removal, six of 17 (35%) had 50%-90% thrombus removal, and seven of 17 (41%) had <50% thrombus extraction. Adjunctive thrombolytic therapy was used in nine of 13 patients with <90% thrombus extraction by PMT; six patients (35%) had contraindications to pharmacologic thrombolytic therapy. An underlying lesion responsible for the occlusion was uncovered in 10 patients (59%). Significant improvement in clinical symptoms was seen in 14 of 17 patients (82%). No complications were noted directly relating to the use of the AngioJet thrombectomy catheter. None of the patients were lost to follow-up during a mean of 8.9 months +/- 5.3 (range, 2-21 months). At 4 and 11 months, recurrence-free survival rates were 81.6% and 51.8%, respectively.

CONCLUSION

PMT with adjunctive thrombolytic therapy is a minimally invasive, low-risk therapeutic option in patients with extensive DVT, associated with clinical benefits including thrombus removal, patency, and relief of symptoms.