The assessment of scapular radiographs: analysis of anteroposterior radiographs of the shoulder and the effect of rotational offset on the glenopolar angle.

The glenopolar angle assesses the rotational alignment of the glenoid and may provide prognostic information and aid the management of scapula fractures. We have analysed the effect of the anteroposterior (AP) shoulder radiograph rotational offset on the glenopolar angle in a laboratory setting and used this to assess the accuracy of shoulder imaging employed in routine clinical practice. Fluoroscopic imaging was performed on 25 non-paired scapulae tagged with 2 mm steel spheres to determine the orientation of true AP views. The glenopolar angle was measured on all the bony specimens rotated at 10° increments. The mean glenopolar angle measured on the bone specimens in rotations between 0° and 20° and thereafter was found to be significantly different (p < 0.001). We also obtained the AP radiographs of the uninjured shoulder of 30 patients treated for fractures at our centre and found that none fitted the criteria of a true AP shoulder radiograph. The mean angular offset from the true AP view was 38° (10° to 65°) for this cohort. Radiological AP shoulder views may not fully project the normal anatomy of the scapular body and the measured glenopolar angle. The absence of a true AP view may compromise the clinical management of a scapular fracture.

Multiple sclerosis in a family on the Faroe Islands.

BACKGROUND: John Kurtzke has proposed that multiple sclerosis (MS) on the Faroe Islands occurred as a result of the spread of a transmittable agent brought to the country during World War II. AIM: Kurtzke's theory has been opposed earlier and in this study, we present a family from the Faroe Islands containing a total of 14 family members with MS which show further inconsistencies with the theory. The present study is to our knowledge, the first description of familial incidences of MS on the Faroe Islands. METHODS: Medical histories were gathered from 12 family members and 6 of the 8 living MS cases were human leukocyte antigen (HLA)-typed. RESULTS: Seven family members had primary progressive MS (PPMS), while five had relapsing remitting MS. The HLA-DR15 allele was carried by the three cases with the most aggressive form of MS and they shared a common haplotypes. The HLA types carried by the remaining cases varied. CONCLUSION: This research questions Kurtzke's theory as three of the cases do not conform to the epidemic cohorts described. Furthermore, there appears to be a higher than usual prevalence of PPMS. The high degree of heterogeneity of the HLA types carried indicates that HLA alleles do not independently explain the risk of developing MS.

Mutational analysis of the active site of human insulin-regulated aminopeptidase.

Insulin-regulated aminopeptidase (IRAP) is a type II integral membrane protein belonging to the gluzincin family of metallopeptidases identified by the characteristic Zn(2+)-coordination sequence element, HEXXH-(18-64X)-E. A second conserved sequence element, the GXMEN motif, positioned 22-32 amino acids N-terminal to the Zn(2+)-coordination sequence element distinguishes the gluzincin aminopeptidases from other gluzincins. To investigate the importance of the G428AMEN and H464ELAH-(18X)-E487 motifs for the activity of IRAP, mutational analysis was carried out. cDNA encoding the full-length transmembrane form of human IRAP was expressed in HEK293 cells and recombinant wild-type IRAP was shown to have biochemical and enzymatic properties similar to those reported for native IRAP and the soluble serum form of IRAP. Mutational analysis using single amino-acid substitutions in the GAMEN motif (G428A, A429G, M430K, M430E, M430I, E431D and E431A) and in the Zn(2+)-binding motif (H464Y, E465D, E465Q, H468Y, E487D and E487Q) resulted in decreased or abolished aminopeptidase activity towards the leucine-para-nitroanilide substrate. The results show that conservation of residues within the GAMEN and Zn(2+)-binding motifs is important for IRAP enzyme activity.

Factors affecting perfusionists' decisions on equipment utilization: results of a United States survey.

The decision to utilize extracorporeal equipment is influenced by a number of factors, including clinical efficacy, cost effectiveness, and personal judgment. The purpose of this study was to report the results of a national survey that examined factors affecting perfusionists' decisions on equipment utilization. An 80-question survey was mailed to chief perfusionists at 1030 U.S. hospitals performing open-heart surgery. 524 completed surveys were returned, which represented 797 hospitals (78.8%) and 671,290 procedures over a 2-year period (July 1996-June 1998). Within the survey, 36 questions pertained to equipment utilization and served as the basis for this report. The perfusion equipment that had seen the greatest reduction in use were; heparin-coated circuits (HCC) (12.0%), in-line blood gas monitors (9.7%), soft-shell venous reservoirs (SSVR) (7.2%), and in-line arterial hemoglobin monitors (6.3%). Cost was the major determinant affecting the decision for the following devices: in-line blood gas monitors (82.4%), cardioplegia in-line delivery filters (75.0%), in-line arterial hemoglobin monitors (69.7%), HCC (55.6%), and SSVR (43.2). Ineffectiveness was the major reason reported for discontinuation of arterial-line bubble traps (64.7%), venous reservoir level detectors (50.0%), and arterial-line pressure manometers with pump shutdown (50.0%). 438 respondents discontinued use of one or more of 29 different devices during the past 2 years. Cost was the major reason in 52.7% of the cases, ineffectiveness in 33.1%, and 14.2% were in a category labeled "other." The pressures brought upon by the changing healthcare structure have influenced perfusionists' equipment selection, with cost being a major factor affecting clinical decisions for certain device utilization.

A retrospective study on perfusion incidents and safety devices.

Despite the acceptance of extracorporeal circulation as an effective modality to facilitate cardiac surgery, patient outcomes can be negatively influenced by the occurrence of perfusion incidents. A perfusion survey was conducted to identify safety techniques and incidents related to cardiopulmonary bypass (CPB). An 80-question survey was mailed to chief perfusionists of all 1030 USA cardiac surgical centers using CPB. The survey was designed to examine practices and incidents that occurred during a 2-year period (July 1996 to July 1998). Five-hundred-and-fifty-two (54% response rate) surveys were returned, which accounted for 797 hospitals (79% of all cardiac centers) and 653,621 surgical procedures. Of the 27 identified CPB safety devices, the highest utilization was arterial line filters (98.5%) and the lowest arterial line bubble traps (3.4%). Of the reported cases, a CPB incident occurred once every 138 cases. The most common occurring incidents were protamine reactions (1:783), coagulation problems (1:771), and heater/cooler failures 11:1809). The rate of occurrence of an incident resulting in a serious injury or death was one for every 1453 procedures. Although techniques and safety devices create a relatively secure environment for CPB, lower incident rates may be achieved with further improvements in coagulation monitoring and incident reporting.

Co-administration of aprotinin and epsilon-aminocaproic acid during cardiopulmonary bypass in a swine model.

Despite the beneficial effects of pharmacological interventions to prevent bleeding and to reduce the need for autogeneic blood, there are concerns that these agents induce a prothrombotic state. The purpose of this study was to examine the coagulation phenomena influenced by the coadministration of epsilon-aminocaproic acid (EACA) and aprotinin during cardiopulmonary bypass (CPB). A swine model of CPB was utilized in this study. During 120 min of CPB, treatment animals (N = 5) received 6 x 10(6) Kiu of aprotinin and 30 grams of EACA; whereas, control animals (N = 3) received an equal volume of 0.9% saline. Indices of thrombogenicity included hematological variables, gross pathology, and circuit examination for the presence of thrombus. The application of both antifibrinolytics resulted in an increase use of heparin. Total heparin requirements were significantly different between treatment group (58,800 +/- 3493 iu) versus control group (51,000 +/- 3464 iu). D-dimer concentration was also significantly higher in the control group (500-1000 ng mL-1) than in the treatment group (250-500 ng mL-1) at 5 and 30 min postprotamine. Other coagulation markers tested were not observed to be statistically significant between groups. Thromboelastographic (TEG) index decreased in the treatment group during the surgical procedure and bypass from 2.74 +/- 2.9 to -1.36 +/- 4.1 as compared to an increase from 2.62 +/- 2.9 to 4.05 +/- 0.4 in the control group. Pathologic analysis revealed occurrences of thrombus formation in small vessels in the lung and kidney glomeruli of treatment animals. The concurrent use of both aprotinin and EACA may induce a prothrombotic or coagulant state as determined by histological assessment.

The effects of nitric oxide on coagulation during simulated extracorporeal membrane oxygenation.

Extracorporeal membrane oxygenation (ECMO) is associated with profound alterations in hemostasis, with platelet dysfunction often being implicated as a causative factor for transfusion. Nitric oxide (NO) has shown to be a rapid yet temporary inhibitor of platelet function. The purpose of this study was to evaluate the effects of NO on platelet number and function in an in vitro ECMO model. Eight silicone membrane oxygenators were primed with fresh, heparinized, bovine blood and allowed to circulate for 48 hours. The treatment group (NO) consisted of four oxygenators that had an end concentration of 20 ppm NO applied to the sweep gas. Platelet counts, methemoglobin levels, plasma-free hemoglobin levels, activated clotting times, and thromboelastographic (TEG) studies were performed at baseline, 1, 6, 12, and 24 h. Scanning electron microscopy (SEM) was performed on sample areas from each oxygenator. The treatment group maintained an average of 25% higher platelet counts than the control group (85.1 +/- 32.0, x 10(3) versus 66.5 +/- 30.9 x 10(3)) although statistical significance was not achieved. Methemoglobin levels were significantly elevated in the treatment circuit at hours 12 and 24 (p < .05). This could be attributed to the lack of a biological interaction that would break down this toxic by-product. TEG indices steadily declined in both groups from baseline (-0.4 +/- 3.6) to (-17.2 +/- 3.3 p < .0007) treatment and (-20 +/- 4.5, p < .0001) control, with the treatment circuit maintaining only slightly improved indices over the most of the study. SEM data showed increased fibrin and cellular deposits in the control group (p = .05) when compared with the treatment group. NO added to the sweep gas of a simulated ECMO circuit at 20 ppm had little effect on the maintenance of platelet number and function.

An in vitro evaluation of a self-contained cardioplegia delivery device.

Focus on improved myocardial protection has prompted the development of delivery systems which can accommodate the demands of increasingly refined cardioprotective strategies. The purpose of this study was to evaluate the Sorin Blood Cardioplegia Console (BCC) for accuracy and precision in the delivery of cardioplegia solutions. An in vitro model was designed to evaluate the following performance characteristics of the BCC: delivery volume (blood and crystalloid) at 50, 250, 375, and 500 ml/min flow rates; potassium end-delivery concentration at blood:crystalloid ratios of 4:1, 8:1, and 16:1; intermittent cardioplegia delivery; and heat transfer of the internal heater/cooler. Differences in blood and cardioplegia volumes between measured and calculated values across all flow rates tested were found to be statistically significant and ranged from 1.4 to 21.5 ml; however, the differences were within the accepted variance of the instrument (+/- 5%). Across all tested ratios, the measured end-potassium concentrations were all within 1 mEq of the expected values, except for the 16:1 ratio at 50 ml/min, which had a 2.52 mEq variance. All significant differences were within the accepted variance of the instrument (+/- 5%). In conclusion, the BCC accurately and delivered cardioplegia volumes and potassium concentrations across all tested conditions with reproducible performance.

[Effect of rodents on reforestation in the moumtain regions near Beijing]. / Vliianine gryzunov na vozobnovleniie lesov v gornykh raionakh Pekina.

From 1993 until 1995, the influence of rodents on reforestation in the mountain regions near Beijing was studied in order to estimate the pressure of rodents on the seed supply, search for effective ways to decrease the loss of seeds due to consumption by rodents, and increase seed germinating power. It was shown that acorns, apricot pits and nuts are almost entirely carried away from the soil surface by rodents, thus suggesting that rodents have a great impact on the seed supply. When the seeds were sowed at a depth of about 5 cm, many of them were not eaten by rodents; 39% of acrons and 18% of apricot pits germinated on the following year. We propose that deep sowing of seeds may effectively decrease the loss of seeds through consumption by rodents.

A comparison of hemolysis rates using intravenous catheters versus venipuncture tubes for obtaining blood samples.

OBJECTIVE: The primary purpose of this study was to compare the rate of hemolysis in blood samples obtained by an i.v. catheter versus the rate in samples obtained by venipuncture (Vacutainer tubes and needles; Becton Dickinson Vacutainer Systems, Franklin Lakes, N.J.). Subsequently, variance in i.v. catheter diameter was reviewed to determine its influence on hemolysis rate of i.v. catheter aspirate. DESIGN: A randomized, prospective study was used to evaluate hemolysis differences between the two blood sampling methods. A descriptive, retrospective review of study data was used to evaluate the importance of the variable i.v. catheter diameter. METHODS: The study group consisted of patients who came to the emergency department and required both an i.v. infusion and blood sampling for determination of electrolyte levels and complete blood cell count. Pediatric patients (younger than 16 years) were excluded. The ED patients who qualified for the study were randomly assigned to either group A or B. The blood samples for patients in the A group were obtained through the i.v. catheter at the time of insertion. The i.v. catheters ranged in size from 24 gauge to 14 gauge. Patients in the B group also had insertion of an i.v. line, but their blood samples were obtained by Vacutainer venipuncture at a separate site. The Vacutainer needle was standardized at 21 gauge. All blood samples were collected by one of seven experienced ED nurses. The nurse who collected the blood sample for an study patient was responsible for result follow-up. RESULTS: A total of 165 patients participated in the study; 87 patients were assigned to the A (i.v.) group, and 78 patients participated in the B (venipuncture) group. In group A a total of 12 of 87 (13.7%) blood samples hemolyzed. Hemolysis occurred in 3 of 78 (3.8%) of group B samples. These findings were statistically significant (p < 0.05). When we examined the variable i.v. catheter diameter, we noted a lower incidence of hemolysis with larger catheter diameters: 24 gauge (100%), 22 gauge (25%), 20 gauge (15%), 18 gauge (10%), 16 gauge (0%), 14 gauge (0%). This findings was statistically significant (p < 0.05). CONCLUSIONS: Hemolysis of blood samples obtained by an i.v. catheter was significantly higher than when blood was obtained through Vacutainer venipuncture. There is an inverse correlation between i.v. catheter diameter and the rate of hemolysis.