Stability of an empirical psychosocial taxonomy across type of diabetes and treatment.

AIMS: The aims of the study were (i) to examine whether an empirical psychosocial taxonomy, based on key diabetes-related variables, is independent of type of diabetes and treatment, and (ii) to further establish the external validation of the taxonomy. METHODS: In a cross-sectional study, 82 patients with Type 1 and 86 patients with Type 2 diabetes mellitus were assigned to one of three psychosocial patient profiles based on their Multidimensional Diabetes Questionnaire (MDQ) scores. General psychological and diabetes-specific measures were obtained through self-report and HbA(1c) was measured. RESULTS: Equal proportions of Type 1 and Type 2 patients, and of patients using insulin and oral medication/diet only were classified within each of the three psychosocial profiles. External validation confirmed the validity and distinctiveness of the patients' profiles. The patient profiles were independent of demographic variables, body mass index, duration of diabetes, complexity of treatment, number of complications, social desirability, and major stress levels. CONCLUSIONS: The Psychosocial Taxonomy for Patients with Diabetes provides a new way to categorize individuals who may have more in common than just their type of diabetes and/or its treatment and can help target interventions to individual patients' needs.

Qualitative assessment of the impact of health care reform on the availability of clinicians for preclinical medical instruction.

PURPOSE: Over the past 5 years, Calgary clinicians experienced the restructuring of health care delivery and a move to a presentation-based curriculum at the University of Calgary. Course coordinators have noted increased difficulty in recruiting clinical lecturers at the preclinical undergraduate level. This study was designed to evaluate the relative importance of factors that may influence the time clinicians spend teaching at this level. SUMMARY: This descriptive survey was conducted within the University of Calgary, Faculty of Medicine, a teaching institution affiliated with the Calgary Regional Health Authority, which is responsible for the delivery of health care within the City of Calgary. Basic scientists, residents, and adjunct medical professionals were excluded from a list of lecturers for the academic year 1996-97, leaving a target population of 386. Respondents were stratified according to university appointment, specialty, type of medical training, and hours taught in the 1996-97 academic year. Dependent variables included the financial constraints, time constraints, health care reform, changes in the undergraduate medical education curriculum, and lack of recognition on availability for teaching. Written comments were also categorized and analyzed according to the same variables. A response rate of 79% (n = 305) was achieved. Of the respondents, 52% agreed that recent reform has made it more difficult to teach; full-time faculty were less likely to agree compared to non-full-time faculty (60% vs. 44%; nonparametric median test, chi 2 = 6.18, p = .046). Twice as many family physicians reported that financial constraint was a factor (66%) when compared to other specialists, whereas relatively few full-time faculty noted it to be a concern (12%) when compared to major part-time (43%) and non-full-time/major part-time appointees (66%; chi 2 = 23.4, p < .0001). Clinicians reporting the most teaching hours (more than 30) were most likely to describe an increase in teaching hours (61%). Nonfaculty members were less aware of the recent curricular changes (73%); however, more family physicians felt that these changes had a positive impact on willingness to teach (10%) compared to surgical (8%) and nonsurgical specialists (9%; chi 2 = 6.07, p = .048). Forty-five percent of respondents agreed that they would be more willing to teach if offered some from of recognition. Two thirds of written comments suggested that recognition should be nonmonetary (e.g., faculty promotion, acknowledgment). CONCLUSIONS: The experience at the University of Calgary suggests that availability of teachers for preclinical undergraduate medical education has diminished as a result of health care reform. Family physicians have been affected the most, and the clinical environment will make it even more difficult to involve this important group of teachers in undergraduate medical education.

Dissemination of melanoma cells within electrocautery plume.

BACKGROUND: The observed occurrence of port site recurrence in laparoscopic surgery for malignant disease has stimulated interest in the dissemination of tumor cells during surgery. Study of electrocautery smoke has revealed the presence of large particles and viable viruses. The purpose of this study was to determine if viable malignant cells are present in suspension within the electrocautery plume. METHODS: Pellets of B16-F0 mouse melanoma cells were cauterized and the plume collected into culture medium. In part 1 of this study, the trypan blue assay was used to assess cell viability immediately after collection and 7 days later. A cautery current of 30 W was applied for 5 minutes. In part 2, the tetrazolium (MTT) viability assay was used to assess cell viability after cauterization of tumor pellets at 10, 20, and 30 W for 5 seconds. RESULTS: Although intact melanoma cells were identified with the trypan blue assay immediately after plume collection, no viable cells were seen at 7 days using this assay. In part 2, viable melanoma cells were present in the culture wells at 7 days. Lower fulguration currents appeared to yield higher cell counts: 2,250 cells/well at 10 W, 2,100 cells/well at 20 W, and 1,800 cells/well at 30 W. CONCLUSIONS: Results of this study confirm that application of electrocautery to a pellet of melanoma cells releases these cells into the plume. These cells are viable and may be grown in culture. This release of malignant cells may explain the appearance of port metastases at sites that are remote from the surgical dissection or that were never in direct contact with the tumor.

Inguinal hernia repair: a survey of Canadian practice patterns.

OBJECTIVE: To describe the preferences of general surgeons across Canada with respect to hernia repair technique. DESIGN: A survey by mailed questionnaire. PARTICIPANTS: All 1452 fellows of the Royal College of Physicians and Surgeons of Canada currently holding a certificate in general surgery. INTERVENTION: Two mailings of the survey: the first in December 1996, the second to nonrespondents in February 1997. MAIN OUTCOME MEASURES: Surgeons' preference of hernia repair technique for specified indications. This was analysed according to practice setting and geographic location. MAIN RESULTS: Based on 706 completed questionnaires, the preferred techniques for repair of primary inguinal hernias were as follows: 23% Bassini, 20% mesh plug, 16% Lichtenstein, 15% laparoscopic, 11% Shouldice and 11% McVay. Preference for laparoscopic repair increased to 34% for recurrent hernias and 35% for bilateral hernias. The Atlantic provinces had the lowest preference rates for laparoscopic repair and the highest rates for the mesh plug technique. CONCLUSIONS: Most surgeons select the type of repair on the basis of the clinical scenario. Large variations in practice exist between provinces.

A prospective comparison of the costs of reusable and limited-reuse laparoscopic instruments.

OBJECTIVE: To compare the cost and performance of 2 types of laparoscopic instrumentation: reusable laparoscopic hook cautery instruments and curved scissors, or limited-reuse laparoscopic hook cautery instruments and curved scissors. DESIGN: A randomized trial. SETTING: The operating room of a tertiary care hospital. METHOD: All general surgeons performing laparoscopic procedures at the hospital were randomized to be supplied with either reusable or limited-reuse hook cautery and curved scissors. Instrument use was recorded, together with principal outcome measures. OUTCOME MEASURES: Life expectancy of the instruments, the number of cases for which they were used, the number, nature and cost of repairs, their purchase cost and surgeon satisfaction. RESULTS: Reusable hook cautery instruments were less expensive than their limited-reuse counterparts. Excellent surgeon satisfaction was reported with the use of this type of instrument. The limited-reuse curved scissors arm of the study was terminated early because of a breach in study protocol. CONCLUSIONS: Reusable hook cautery instruments were better than their limited-reuse counterparts. Rigorous attempts to compare the cost of laparoscopic instruments may be limited by their rapid evolution in design and the availability of many types of instruments on the market.

Reuse of disposable laparoscopic instruments: cost analysis.

OBJECTIVE: To evaluate the cost benefits of reusing disposable laparoscopic instruments. DESIGN: A cost-analysis study based on a review of laparoscopic and thoracoscopic procedures performed between August 1990 and January 1994, including analysis of disposable instrument use, purchase records, and reprocessing costs for each instrument. SETTING: The general surgery department of a 461-bed teaching hospital where disposable laparoscopic instruments are routinely reused according to internally validated reprocessing protocols. METHODS: Laparoscopic and thoracoscopic interventions performed between August 1990 and January 1994 for which the number and types of disposable laparoscopic instruments were standardized. MAIN OUTCOME MEASURES: Reprocessing cost per instrument, the savings realized by reusing disposable laparoscopic instruments and the cost-efficient number of reuses per instrument. RESULTS: The cost of reprocessing instruments varied from $2.64 (Can) to $4.66 for each disposable laparoscopic instrument. Purchases of 10 commonly reused disposable laparoscopic instruments totalled $183,279, and the total reprocessing cost was estimated at $35,665 for the study period. Not reusing disposable instruments would have cost $527,575 in instrument purchases for the same period. Disposable laparoscopic instruments were reused 1.7 to 68 times each. CONCLUSIONS: Under carefully monitored conditions and strict guidelines, reuse of disposable laparoscopic and thoracoscopic instruments can be cost-effective.

Preliminary study of electrocautery smoke particles produced in vitro and during laparoscopic procedures.

BACKGROUND: The objective of this preliminary study was to describe the particles contained in cautery smoke produced during five laparoscopic procedures and verify the collection method during three laboratory experiments on ex vivo animal tissue. METHODS: A cascade impactor collected the smoke according to particle size, and particle weights were calculated on an electronic microbalance. Electron microscopic analysis and energy dispersive X-ray evaluation were used to determine particle morphology and elemental composition. RESULTS: The particles, distributed according to size on the seven rotating trays of the impactor, had diameters ranging from 0.05 to >25 micro m, with most being 0.1-1 micro m. In vitro experiments yielded more particles, especially larger (>5 micro m) ones, than the surgical procedures, because the cauterized specimens could be placed much closer to the cascade impactor in the laboratory environment, eliminating most obstacles to particle recovery. In the laparoscopic surgery patients, larger particles, because of their physical properties, were more likely to remain trapped in the abdomen or to drop off in the collection apparatus. Uniformly, two populations of particles were demonstrated--either large, irregular fragments (2-25 micro m) rich in carbon and oxygen, suggesting structural cellular components, or small homogeneous spheres (0.1-0.5 micro m) composed of sodium, magnesium, calcium, and potassium salts. CONCLUSIONS: This study demonstrates the presence of breathable aerosols and cell-size fragments in the cautery smoke produced during laparoscopic procedures. Their exact chemical composition and potential adverse effects for patients and personnel are not known.

Reuse of disposable laparoscopic instruments: a study of related surgical complications.

OBJECTIVE: To determine the rate of surgical complications related to reuse of disposable laparoscopic instruments. DESIGN: A review of all laparoscopic and thoracoscopic procedures done between August 1990 and January 1994 in which disposable laparoscopic instruments were reused. SETTING: Department of general surgery in a 461-bed teaching hospital. PATIENTS: Patients who underwent 874 laparoscopic and thoracoscopic procedures in which disposable laparoscopic instruments were reused according to validated reprocessing protocols. MAIN OUTCOME MEASURES: The incidence of superficial and deep wound infections and complications related to instrument malfunction. RESULTS: The combined rate for deep and superficial infections was 1.8%. No complications related to a disposable instrument malfunction were found. CONCLUSION: Disposable laparoscopic instruments may be safely reused under carefully monitored conditions and with strict guidelines.

Partial laparoscopic splenectomy for trauma: technique and case report.

We describe the course of a patient who underwent partial laparoscopic splenectomy after a fall while skiing. Computed tomography revealed intact liver and kidneys with fragmentation of the upper third of the spleen and a left upper quadrant hematoma. Splenic artery angiogram showed devascularization of the superior pole, and selective cannulation of the superior polar artery demonstrated extravasation of contrast media. The superior polar artery was embolized with three coils to control bleeding. After laparoscopic exploration, the patient underwent partial laparoscopic splenectomy of the superior pole, which consisted of ligating the short gastric vessels and incising the splenic parenchyma 6 to 8 mm above the ischemic demarcation line produced by embolization of the superior polar artery, where a deep transverse laceration was located. The specimen was retrieved in a plastic bag. Intraoperative blood loss was less than 50 ml, and the patient left the hospital on the 3rd postoperative day after an uneventful recovery. Partial laparoscopic splenectomy can be performed safely, and its role needs to be delineated.

Residual organic debris on processed surgical instruments.

This preliminary study describes the degree of cleanliness of three categories of surgical instruments after processing (ie, decontamination, inspection, sterilization). The three categories were reusable laparoscopic, reused disposable laparoscopic, and conventional surgical instruments. The objective of the study was to identify from visual inspection and microscopic examination residual particles, stains, or liquid on processed instruments. The investigators studied 32 instruments selected at random from a hospital's supply of processed surgical instruments. On visual inspection, 90.6% (29/32) of the instruments appeared clean. Microscopic examination with a photomicrographic system, however, revealed residual debris on 84.3% (27/32) of the instruments. The quantity of residual debris on both types of laparoscopic instruments (ie, reusable, reused disposable) was equivalent. The conventional instruments contained less residual debris than the laparoscopic instruments. Sites that contained residual debris included junctions between insulating sheaths and activating mechanisms of laparoscopic instruments and articulations and grooves of forceps. More research is needed to determine the prevalence and clinical significance of these findings.

Learning surgical technical skills.

Training issues raised by the recent introduction of laparoscopic surgical techniques led to this analysis of motor-skill learning principles as they apply specifically to the learning of technical surgical skills. The most accepted theories of motor-skill learning are presented, not as opposing views, but as complementary constructs. The behaviourist school of thought's main contribution is the executive routine or knowledge of the steps of a procedure. Schmidt's schema theory and MacKay's node theory suggest that perceptual information may play an important role in the quality of the performance. The conclusions reached from neuropsychologic testing experiments on surgeons are that visuospatial perceptual skills (the ability to represent mentally the physical environment and the movement to be performed) are the major determinants of surgical technical performance. Learners should make use of learning strategies that improve mental representation of a skill and the corresponding anatomy. Specific strategies discussed include imagery, mental practice and a systematic review of performance that focuses on the perceptual feedback received by the learner.

Detection of bovine coronavirus and type A rotavirus in neonatal calf diarrhea and winter dysentery of cattle in Quebec: evaluation of three diagnostic methods.

The use of direct electron microscopy, enzyme-linked immunosorbent assay, and protein A-gold immunoelectron microscopy for the identification of bovine coronavirus and type A rotavirus were examined. Two hundred and forty-nine samples from diarrheic calves and winter dysenteric cattle from seven geographic areas in Quebec were examined for the presence of viruses by direct electron microscopy of negatively stained preparations. In addition, all the samples were analyzed by enzyme-linked immunosorbent assay, and a random selection of 47 samples were also analyzed by protein A-gold immunoelectron microscopy. Thirty-nine percent of samples examined by direct electron microscopy contained viral particles; bovine coronavirus and type A rotavirus were the most common viruses involved. Overall agreement between any two of the methods used compared favorably with results obtained by others using similar methods. The presence of coronavirus and rotavirus in fecal samples obtained from neonatal calves and the presence of coronavirus in samples from winter dysenteric adult cattle suggested their etiological roles in the respective diseases. Furthermore, results from protein A-gold immunoelectron microscopy of coronavirus-like particles implied that a different coronavirus or some other viruses might be involved in these diseases. Finally, the efficiency of direct electron microscopy, enzyme-linked immunosorbent assay and protein A-gold immunoelectron microscopy as diagnostic tools is discussed.

Protection of mice and swine against infection with Actinobacillus pleuropneumoniae by vaccination.

CaCl2 and LiCl cell extracts and a crude hemolysin preparation were isolated from Actinobacillus pleuropneumoniae serotype 1 strain 4074 and tested for protection against A. pleuropneumoniae serotype 1 and 5 in mice. The LiCl cell extract adsorbed on AlPO4 and the crude hemolysin preparation adsorbed on Al(OH)3 showed a highly significant protection (P < 0.01) against both serotypes. Different vaccine preparations were used to immunize pigs by intra-muscular injection at days 0 and 14; the pigs were then challenged at day 21 by intra-tracheal inoculation of 1 x 10(8) colony forming units (CFU) of a serotype 1 strain 4074. A vaccine which combined the LiCl extract and the crude hemolysin preparation adsorbed on Al(OH)3 gave the best protection with no mortality and no sign of morbidity in the vaccinated pigs. In the other experimental groups which included a group immunized with a commercial bacterin, mortality, respiratory disease and extensive pulmonary lesions were noted. This mixture shows good potential as a vaccine against pleuropneumonia in pigs.

Linea alba closure: determination of ideal distance between sutures.

An experiment was conducted to determine the optimal distance between sutures in closure of abdominal midline incisions. Human cadaveric fascia was harvested soon after death and stored at -70 degrees C until testing. Suture pullout tests were performed to determine the maximal force applied to the fascia before pullout. Fascia from the opposite side of the same cadaver was used as a control. In a first series of testing, we observed that the pullout force of two sutures dropped linearly as they were brought closer than 12 mm apart. In a second series we observed no increase in pullout force using multiple sutures closer together compared to fewer sutures 15 mm apart. The experiments suggest that the mechanical requirements of closing a midline abdominal incision are met by placing sutures 10-15 mm apart.

[Serological study of the incidence of murine viruses in a population of small wild rodents (Microtus pennsylvanicus Ord, 1815)]. / Etude sérologique sur l'incidence de virus murins dans une population de petits rongeurs sauvages (Microtus pennsylvanicus Ord, 1815).

The results of a serological survey of a free-living population of meadow voles (Microtus pennsylvanicus) in Pinawa, Manitoba (Canada) showed that these animals possessed antibodies to six of the eleven viruses tested for, namely: reovirus type 3, murine encephalomyelitis agent, ectromelia virus, murine adenovirus, murine hepatitis virus and lymphocytic choriomeningitis virus. The significant increase in the number of individuals possessing specific antibodies suggests that these viruses, or related viruses, may be responsible for the decline in the population studied.

Experimental infection of young rabbits with a rabbit enteric coronavirus.

The clinical signs and lesions caused by the rabbit enteric coronavirus (RECV) were studied in young rabbits orally inoculated with a suspension containing RECV particles. The inoculated animals were observed daily for evidence of diarrhea. Fecal samples and specimens from the small intestine and from the gut associated lymphoid tissue (GALT) were collected from 2 h to 29 days postinoculation (PI) and processed for immune electron microscopy (IEM) and light microscopy. Coronavirus particles were detected in the cecal contents of most inoculated animals from 6 h to 29 days PI. Lesions were first observed 6 h PI and were characterized by a loss of the brush border of mature enterocytes located at the tips of intestinal villi and by necrosis of these cells. At 48 h PI, short intestinal villi and hypertrophic crypts were noted. In the GALT, complete necrosis of the M cells as well as necrosis of the enterocytes lining the villi above the lymphoid follicules with hypertrophy of the corresponding crypts were observed in all the animals. Five inoculated rabbits had diarrhea three days PI. The presence of RECV particles in the feces of the sick animals and the microscopic lesions observed in the small intestine suggested that the virus was responsible for the clinical signs. A few inoculated rabbits remained free of diarrhea. Fecal material collected at postmortem examination contained RECV particles. The results suggest that the virus could also produce a subclinical infection.

Mouse hepatitis virus 3 replication in T and B lymphocytes correlate with viral pathogenicity.

Viral pathogenicity may be regulated by host defense mechanisms at the virus-immune cell interaction level. The immune system plays an important role in the outcome of acute disease induced by the mouse hepatitis virus type 3 (MHV3) virus. The lymphoid cells act as effectors in the virus elimination as well as targets for viral replication. In order to demonstrate a correlation between MHV3 pathogenicity and viral replication in lymphocytes, genetically-determined resistant A/J and susceptible C57BL/6 mice were infected with pathogenic (L2-MHV3) or nonpathogenic (YAC-MHV3) viral strains. Pathogenicity and histopathologic studies have revealed that lymphoid organs such as thymus and spleen, showed injuries or atrophy in susceptible mice infected with L2-MHV3. No histopathologic lesions in the lymphoid organs occurred in C57BL/6 mice infected with YAC-MHV3 or A/J mice infected with both viruses. The mechanisms involved in the lymphoid injuries were studied regarding viral replication in the lymphoid organs and cells in infected mice. Results indicate that cell depletion in lymphoid organs is caused by a complete viral replication in lymphoid cells. Thy1.2+ and surface IgM+ lymphoid cells from susceptible C57BL/6 mice infected with L2-MHV3 were permissive to viral replication and to subsequent cell lysis. No cell lysis, however, occurred in lymphoid cells from C57BL/6 mice infected with YAC-MHV3 and A/J mice infected with both virus strains. In vitro studies, with purified T and B cell populations were performed to determine the mechanism effecting susceptibility or resistance to viral-induced cell lysis occurring in such cells. A blockade, probably occurring at the viral RNA polymerase activity level, prevents viral replication in resistant cells between the stages of fixation of the virus at the cell-surface receptor and the viral protein translation. These experiments indicate that an intrinsic virus-specific resistant mechanism occurs in lymphoid cells that plays a major role in the viral pathogenicity.

Enzootic pneumonia in feeder pigs: Observations on causal factors.

A number of factors were studied in eight feeder pig herds, affected with severe or mild enzootic pneumonia, in order to identify those associated with this disease. Piggeries with poor facilities and management and where procurement of piglets was from sales barns were more severely affected with enzootic pneumonia than were those with good facilities and where pigs originated directly from breeding units. Serological tests and virus isolation revealed that all herds had been exposed to Mycoplasma hyopneumoniae and to many viruses; transmissible gastroenteritis virus infection was the only viral infection that was apparently associated with the severity of enzootic pneumonia and the performance observed in the herds.