Canadian Association of Radiologists Musculoskeletal System Diagnostic Imaging Referral Guideline

The Canadian Association of Radiologists (CAR) Musculoskeletal System Expert Panel consists of musculoskeletal radiologists, a family physician, a sports and exercise medicine physician, emergency medicine physicians, a patient advisor, and an epidemiologist/guideline methodologist. After developing a list of 25 musculoskeletal clinical/diagnostic scenarios, a systematic rapid scoping review was undertaken to identify systematically produced referral guidelines that provide recommendations for 1 or more of these clinical/diagnostic scenarios. Recommendations from 41 guidelines (50 publications) and contextualization criteria in the Grading of Recommendations, Assessment, Development and Evaluations (GRADE) for guidelines framework were used to develop 124 recommendation statements across the 25 scenarios related to the evaluation of the musculoskeletal system. This guideline presents the methods of development and the recommendations for imaging in the context of musculoskeletal pain, infection, tumors, arthropathies, metabolic bone disease, stress injuries, orthopedic hardware, avascular necrosis/bone infarction, and complex regional pain syndrome.

Longitudinal evaluation of diffusion tensor imaging and cognition in systemic lupus erythematosus

Objective

This pilot study aimed to examine longitudinal changes in brain structure and function in patients with systemic lupus erythematosus (SLE) using diffusion tensor imaging (DTI) and neuropsychological testing.

Methods

Fifteen female SLE patients with no history of major neuropsychiatric (NP) manifestations had brain magnetic resonance imaging (MRI) with DTI at baseline and approximately 1.5 years later. At the same time points, a standardized battery of cognitive tests yielding a global cognitive impairment index (CII) was administered. At baseline, the SLE patients had mean age of 34.0 years (SD = 11.4), mean education of 14.9 years (SD = 2.1), and mean disease duration of 121.5 months (SD = 106.5). The MRI images were acquired with a 3T GE MRI scanner. A DTI sequence with 33 diffusion directions and b-value of 800 s/mm2 was used. Image acquisition time was about 10 minutes.

Results

No significant change in cognitive dysfunction (from the CII) was detected. Clinically evaluated MRI scans remained essentially unchanged, with 62% considered normal at both times, and the remainder showing white matter (WM) hyperintensities that remained stable or resolved. DTI showed decreased fractional anisotropy (FA) and increased mean diffusivity (MD) in bilateral cerebral WM and gray matter (GM) with no major change in NP status, medical symptoms, or medications over time. Lower FA was found in the following regions: left and right cerebral WM, and in GM areas including the parahippocampal gyrus, thalamus, precentral gyrus, postcentral gyrus, angular gyrus, parietal lobe, and cerebellum. Greater MD was found in the following regions: left and right cerebral WM, frontal cortex, left cerebral cortex, and the putamen.

Conclusions

This is the first longitudinal study of DTI and cognition in SLE, and results disclosed changes in both WM and GM without cognitive decline over an 18-month period. DTI abnormalities in our participants were not associated with emergent NP activity, medical decline, or medication changes, and the microstructural changes developed in the absence of macrostructural abnormalities on standard MRI. Microstructural changes may relate to ongoing inflammation, and the stability of cognitive function may be explained by medical treatment, the variability of NP progression in SLE, or the impact of cognitive reserve.

Online Profile of Canadian Diagnostic Radiology Residents: Do Residents Alter Their Profile When Applying for Fellowships?

This article was migrated. The article was marked as recommended. Objective: Survey the online profile of Canadian Diagnostic Radiology residents at the University of Alberta and determine whether residents alter it when applying for fellowships, due to the perceived assessment of their profile by Fellowship Selection Committees. Methods: A cross-sectional study was performed by distributing an anonymous questionnaire to 31 residents at the University of Alberta. Descriptive and ANOVA statistical analyses were performed. P-value less than 0.01 was considered statistically significant. Results: 26 questionnaires were completed. The average age was 28.9. 91.4% of residents have Facebook, followed by Instagram (30.4%) and ResearchGate (30.4%). 52.5% viewed their profile at least once daily, although 83.3% make changes to it less than once per month. The profiles were primarily for personal use (72.7%) and none were solely for professional use. 53.8% felt that Fellowship Selection Committees assess their profile and 69.2% were neutral or agreed with this. In anticipation, 70.6% would restrict profile viewership, while 29.4% would change their profile name, predominantly due to the sensitive and personal information. 92.8% would make the changes at least 2 months prior to the application deadline. There was no statistical difference between age and having a profile (p=0.597), agreement with Fellowship Selection Committees using a resident's profile for selection (p=0.91), how often residents viewed (p=0.827) or changed (p=0.934) their profile. Conclusion: Nearly all Canadian residents at our institution have an online profile and over half view it at least once daily. The majority of residents perceived that their profile is assessed by Fellowship Selection Committees, but are not against it. In anticipation, most residents would alter their profile prior to the application deadline mainly due to the sensitive and personal information.

Podcasting as an Innovative Approach to Enhance Career Counseling in Canadian Undergraduate Medical Education

This article was migrated. The article was not marked as recommended. In a 2012 Royal College of Canada survey of newly trained physicians, 53% did not receive career counseling while in medical school. The purpose of this initiative was to produce a podcast series designed to inform students of the different specialties. The podcast series featured 8 prominent physicians with long-standing experience in their specialty. The series provides students with an archive of podcasts to help them make informed career decisions. The opportunity to intimately learn about a specialty through the eyes of a physician and the flexibility podcasting offers makes this innovation a valuable and insightful resource for medical students.

Medical specialty preferences in early medical school training in Canada

OBJECTIVES

To understand what medical students consider when choosing their specialty, prior to significant clinical exposure to develop strategies to provide adequate career counseling.

METHODS

A cross-sectional study was performed by distributing optional questionnaires to 165 first-year medical students at the University of Ottawa in their first month of training with a sample yield of 54.5% (n=90).  Descriptive statistics, analysis of variance, Spearman's rank correlation, Cronbach's alpha coefficient, Kaiser-Meyer-Olkin Measure, and exploratory factor analyses were used to analyze the anonymized results.

RESULTS

"Job satisfaction", "lifestyle following training" and, "impact on the patient" were the three highest rated considerations when choosing a specialty.  Fifty-two and seventeen percent (n=24) and 57.89% (n=22) of males and females ranked non-surgical specialties as their top choice. Student confidence in their specialty preferences was moderate, meaning their preference could likely change (mean=2.40/5.00, SD=1.23). ANOVA showed no significant differences between confidence and population size (F(2,86)=0.290, p=0.75) or marital status (F(2,85)=0.354, p=0.70) in both genders combined. Five underlying factors that explained 44.32% of the total variance were identified. Five themes were identified to enhance career counseling.

CONCLUSIONS

Medical students in their first month of training have already considered their specialty preferences, despite limited exposure. However, students are not fixed in their specialty preference. Our findings further support previous results but expand what students consider when choosing their specialty early in their training. Medical educators and administrators who recognize and understand the importance of these considerations may further enhance career counseling and medical education curricula.

Assessment of Tocilizumab (Anti-Interleukin-6 Receptor Monoclonal) as a Potential Treatment for Chronic Antibody-Mediated Rejection and Transplant Glomerulopathy in HLA-Sensitized Renal Allograft Recipients

Extending the functional integrity of renal allografts is the primary goal of transplant medicine. The development of donor-specific antibodies (DSAs) posttransplantation leads to chronic active antibody-mediated rejection (cAMR) and transplant glomerulopathy (TG), resulting in the majority of graft losses that occur in the United States. This reduces the quality and length of life for patients and increases cost. There are no approved treatments for cAMR. Evidence suggests the proinflammatory cytokine interleukin 6 (IL-6) may play an important role in DSA generation and cAMR. We identified 36 renal transplant patients with cAMR plus DSAs and TG who failed standard of care treatment with IVIg plus rituximab with or without plasma exchange. Patients were offered rescue therapy with the anti-IL-6 receptor monoclonal tocilizumab with monthly infusions and monitored for DSAs and long-term outcomes. Tocilizumab-treated patients demonstrated graft survival and patient survival rates of 80% and 91% at 6 years, respectively. Significant reductions in DSAs and stabilization of renal function were seen at 2 years. No significant adverse events or severe adverse events were seen. Tocilizumab provides good long-term outcomes for patients with cAMR and TG, especially compared with historical published treatments. Inhibition of the IL-6-IL-6 receptor pathway may represent a novel approach to stabilize allograft function and extend patient lives.

JC polyomavirus viremia and progressive multifocal leukoencephalopathy in human leukocyte antigen-sensitized kidney transplant recipients desensitized with intravenous immunoglobulin and rituximab

BACKGROUND

Desensitization (DES) with intravenous immunoglobulin (IVIG) + rituximab is effective, safe, and increases the transplantation rate in human leukocyte antigen-sensitized patients. However, reports of progressive multifocal leukoencephalopathy (PML) caused by JC polyomavirus (JCPyV) in autoimmune patients treated with rituximab is concerning. Here, we report on the JCPyV viremia and PML status in kidney transplant patients with/without DES (non-DES).

METHODS

In total 1195 and 699 DNA samples from plasma in 117 DES (78% lymphocyte-depleting [LyD] induction) and 100 non-DES patients (45% LyD), respectively, were submitted for JCPyV-polymerase chain reaction. Results were compared in both groups.

RESULTS

No patients in either DES or non-DES developed PML or presented with any neurological symptoms. The JCPyV viremia rate was similar in DES and non-DES patients (3/117 vs. 9/100, P = 0.07). The JCPyV levels were low (median peak levels, 1025 copies/mL) and JCPyV viremia was observed only once during the study period in most patients. All 3 DES patients with JCPyV(+) received 1 dose rituximab and no DES patients with >1 dose rituximab showed JCPyV(+). All 3 JCPyV(+) DES patients received LyD induction, while only 2 of 9 JCPyV(+) non-DES patients did so, and the remaining 7 received non-LyD or no induction. JCPyV in leukocyte was mostly negative in DES and non-DES patients. Immunosuppression in patients with or without JCPyV(+) was similar. BK polyomavirus viremia was observed more commonly in patients with JCPyV(+) than in those without (P < 0.02).

CONCLUSIONS

Patients with IVIG + rituximab DES followed by transplantation with LyD induction and additional rituximab rarely show JCPyV viremia and appear at low risk for PML.

The femoral head-neck contour varies as a function of physeal development

OBJECTIVES

The purpose of this study was to investigate whether the femoral head-neck contour, characterised by the alpha angle, varies with the stage of physeal maturation using MRI evaluation of an asymptomatic paediatric population.

METHODS

Paediatric volunteers with asymptomatic hips were recruited to undergo MRI of both hips. Femoral head physes were graded from 1 (completely open) to 6 (completely fused). The femoral head-neck contour was evaluated using the alpha angle, measured at the 3:00 (anterior) and 1:30 (anterosuperior) positions and correlated with physeal grade, with gender sub-analysis performed.

RESULTS

A total of 43 asymptomatic paediatric volunteers (26 male, 17 female) with mean age 13.0 years (eight to 18) were included with review of bilateral hip MRIs. Correlation between the physeal grade and alpha angle was moderate in males at both the 3:00 (r = 0.477, p < 0.001) and 1:30 (r = 0.509, p < 0.001) positions, whereas there was no significant correlation in females. A significant difference was found between the alpha angles of all the physeal grades (3:00, p = 0.030, 1:30, p = 0.005), but only in males, with the angle increasing with higher grades. For physeal grading, the inter-reader reliability was substantial (intraclass correlation coefficient (ICC) = 0.694), and the intra-reader reliability was also substantial (ICC = 0.788).

CONCLUSION

The femoral head-neck contour varies and correlates with the stage of physeal development, but only in males, with the alpha angle increasing with progressive physeal maturation. This suggests that gender differences exist in the natural physiological growth, development or remodelling of femoral head-neck junction. In males, pre-physeal fusion may be a critical period of vulnerability for development of morphologic abnormalities of the femoral head-neck junction. Cite this article: Bone Joint Res 2015;4:17-22.

Third-degree burns caused by ignition of chlorhexidine: A case report and systematic review of the literature

Ignition of chlorhexidine by an electrocautery unit is rare but can have devastating consequences for the patient and the surgeon. A case involving a 77-year-old man who underwent removal of an indwelling artificial urethral sphincter is presented. The chlorhexidine was ignited when the urologist activated the electrocautery unit, causing third-degree burns to the patient. A plastic surgeon treated the burns with surgical debridement and split-thickness skin grafting. A systematic review of the literature was performed with best practice recommendations. To the authors' knowledge, the present case is the ninth such case reported.

Third-degree burns caused by ignition of chlorhexidine: A case report and systematic review of the literature

Ignition of chlorhexidine by an electrocautery unit is rare but can have devastating consequences for the patient and the surgeon. A case involving a 77-year-old man who underwent removal of an indwelling artificial urethral sphincter is presented. The chlorhexidine was ignited when the urologist activated the electrocautery unit, causing third-degree burns to the patient. A plastic surgeon treated the burns with surgical debridement and split-thickness skin grafting. A systematic review of the literature was performed with best practice recommendations. To the authors' knowledge, the present case is the ninth such case reported.

Elevation as a treatment for fasciotomy wound closure

There are currently numerous techniques described in the literature that attempt to optimize wound closure following a fasciotomy. However, primary closure of fasciotomy wounds continues to be difficult to accomplish successfully because of the underlying edema sustained from the compartment syndrome. The approach described in the present report is simple and physiologically sound, and addresses the underlying pathology. The authors focus on alleviating edema by strictly elevating the limb, followed by primary closure. Twelve consecutive fasciotomy wounds, referred from 2005 to 2012, were closed using this approach. The average wound closure time was 3.4 days (range three to five days) following the initial consultation. All 12 fasciotomy wounds responded with no revisions, complications, failures or loss of skin sensation. The approach was successful in all anatomical locations that were closed and conversion to any techniques currently available in the literature was not necessary. There are no costs associated with this approach, making it practical in settings with limited resources. It has a high success rate, superior cosmetic results and, most importantly, it achieves an efficient closure time. Therefore, this approach is superior to current techniques and should be a part of a plastic surgeon's armamentarium.

Early outcomes of arthroplasty of the first carpometacarpal joint using pyrocarbon spherical implants

The first carpometacarpal joint (CMC) is the most common hand joint to develop osteoarthritis. A survey found that many hand surgeons have revisited implant arthroplasty because it preserves critical structures. However, there is currently no implant with an ideal design and material composition. The present study was the first to use and evaluate early outcomes of pyrocarbon spherical implants for arthroplasty of the first CMC in patients with Eaton-Littler stage II and III osteoarthritis. A single surgeon performed 24 arthroplasties (23 patients [20 women, three men] with a mean age of 56 years [range 46 to 75 years]) of the first CMC (nine right hands and 15 left hands) using pyrocarbon spherical implants from May 2010 to April 2013. All patients failed conservative management. At a mean (± SD) of 18.5±11.16 months postoperatively (range 4.3 to 38.9 months), the mean Kapandji score was 8.8 of 10 (range 7 to 10), the average pre- and postoperative values on the visual pain scale were 8.96±0.64 of 10 (range 8 to 10) and 1.13±1.22 of 10 (range 0 to 4), respectively. All patients were either very satisfied (score = 5) or satisfied (score = 4) with the procedure, with a mean satisfaction score of 4.76±0.44 of 5.00 (range 4 to 5). The mean postoperative Disabilities of the Arm, Shoulder and Hand (DASH) score was 11.79±14.29 (range 0 to 49.17). The most recent radiographic evaluations confirmed that all implants were stable with no erosion of nearby cancellous bone. There were no implant subluxations, dislocations or revisions. Early outcomes show promising results and support continued use of this implant for arthroplasty. However, longer-term follow-up will be needed to confirm these results.

A multicenter phase 1 study of PX-866 in combination with docetaxel in patients with advanced solid tumours

Background:

This phase I, dose-finding study determined the safety, maximum tolerated dose (MTD)/recommended phase 2 dose (RP2D), pharmacokinetics, and antitumour activity of PX-866, a phosphatidylinositol 3-kinase inhibitor, combined with docetaxel in patients with incurable solid tumours.

Methods:

PX-866 was administered at escalating doses (4–8 mg daily) with docetaxel 75 mg m⁻² intravenously every 21 days. Archived tumour tissue was assessed for potential predictive biomarkers.

Results:

Forty-three patients were enrolled. Most adverse events (AEs) were grade 1 or 2. The most frequent study drug-related AE was diarrhoea (76.7%), with gastrointestinal disorders occurring in 79.1% (docetaxel-related) and 83.7% (PX-866-related). No dose-limiting toxicities were observed. The RP2D was 8 mg, the same as the single-agent MTD. Co-administration of PX-866 and docetaxel did not affect either drug's PKs. Best responses in 35 evaluable patients were: 2 partial responses (6%), 22 stable disease (63%), and 11 disease progression (31%). Eleven patients remained on study for >180 days, including 8 who maintained disease control on single-agent PX-866. Overall median progression-free survival (PFS) was 73.5 days (range: 1–569). A non-significant association between longer PFS for PIK3CA-MUT/KRAS-WT vs PIK3CA-WT/KRAS-WT was observed.

Conclusion:

Treatment with PX-866 and docetaxel was well tolerated, without evidence of overlapping/cumulative toxicity. Further investigation with this combination is justified.

Toward an ecological perspective of resident teaching clinic

Teaching clinic managers struggle to convert performance data into meaningful behavioral change in their trainees, and quality improvement measures in medicine have had modest results. This may be due to several factors including clinical performance being based more on team function than individual action, models of best practice that are over-simplified for real patients with multiple chronic diseases, and local features that influence behavior but are not aligned with core values. Many are looking for a new conceptual structure to guide them. In this paper we briefly review several theories of action from the social and complexity sciences, and synthesize these into a coherent 'ecological perspective'. This perspective focuses on stabilizing features and narrative, which select for behaviors in clinic much like organisms are selected for in an ecosystem. We have found this perspective to be a useful guide for design, measurement, and joint learning in the teaching clinic.

Regulation of CovR expression in Group B Streptococcus impacts blood-brain barrier penetration

Group B Streptococcus (GBS) is an important cause of invasive infections in humans. The pathogen encodes a number of virulence factors including the pluripotent beta-haemolysin/cytolysin (beta-H/C). As GBS has the disposition of both a commensal organism and an invasive pathogen, it is important for the organism to appropriately regulate beta-H/C and other virulence factors in response to the environment. GBS can repress transcription of beta-H/C using the two-component system, CovR/CovS. Recently, we described that the serine/threonine kinase Stk1 can phosphorylate CovR at threonine 65 to relieve repression of beta-H/C. In this study, we show that infection with CovR-deficient GBS strains resulted in increased sepsis. Although CovR-deficient GBS showed decreased ability to invade the brain endothelium in vitro, they were more proficient in induction of permeability and pro-inflammatory signalling pathways in brain endothelium and penetration of the blood-brain barrier (BBB) in vivo. Microarray analysis revealed that CovR positively regulates its own expression and regulates the expression of 153 genes. Collectively, our results suggest that the positive feedback loop which regulates CovR transcription modulates host cell interaction and immune defence and may facilitate the transition of GBS from a commensal organism to a virulent meningeal pathogen.

The onset of rapidly progressive neurologic deterioration after a brief gastrointestinal illness in a renal allograft recipient

Renal transplant recipients are at increased risk for life-threatening complications, most commonly infections. Because of their impaired cell-mediated immunity, these patients are particularly susceptible to organisms that rely on intracellular survival and spread, such as Listeria monocytogenes. Despite being a food-borne pathogen, L. monocytogenes is associated with significant morbidity and mortality. Here we report the case of a renal transplant recipient who developed rapidly progressive neurological symptoms after a brief gastrointestinal illness. Magnetic resonance imaging scan of the brain showed a large mass that was identified as an abscess due to L. monocytogenes. Timely aspiration and antibiotic treatment resulted in complete recovery, as opposed to worse outcomes in the available case reports. We further review the epidemiology, microbiology, clinical presentation, and therapeutic options for listerial brain abscess.

Regulation of cytotoxin expression by converging eukaryotic-type and two-component signalling mechanisms in Streptococcus agalactiae

Signal transducing mechanisms are essential for regulation of gene expression in both prokaryotic and eukaryotic organisms. Regulation of gene expression in eukaryotes is accomplished by serine/threonine and tyrosine kinases and cognate phosphatases. In contrast, gene expression in prokaryotes is controlled by two-component systems that comprise a sensor histidine kinase and a cognate DNA binding response regulator. Pathogenic bacteria utilize two-component systems to regulate expression of their virulence factors and for adaptive responses to the external environment. We have previously shown that the human pathogen Streptococcus agalactiae (Group B Streptococci, GBS) encodes a single eukaryotic-type serine/threonine kinase Stk1, which is important for virulence of the organism. In this study, we aimed to understand how Stk1 contributes to virulence of GBS. Our results indicate that Stk1 expression is important for resistance of GBS to human blood, neutrophils and oxidative stress. Consistent with these observations, Stk1 positively regulates transcription of a cytotoxin, beta-haemolysin/cytolysin (beta-H/C) that is critical for survival of GBS in the bloodstream and for resistance to oxidative stress. Interestingly, positive regulation of beta-H/C by Stk1 requires the two-component regulator CovR. Further, we show that Stk1 can negatively regulate transcription of CAMP factor in a CovR-dependent manner. As Stk1 phosphorylates CovR in vitro, these data suggest that serine/threonine phosphorylation impacts CovR-mediated regulation of GBS gene expression. In summary, our studies provide novel information that a eukaryotic-type serine/threonine kinase regulates two-component-mediated expression of GBS cytotoxins.

Testing the exportability of a tool for detecting operational problems in VA teaching clinics

BACKGROUND

Recurrent operational problems in teaching clinics may be caused by the different medical preferences of patients, residents, faculty, and administrators. These preference differences can be identified by cultural consensus analysis (CCA), a standard anthropologic tool.

OBJECTIVE

This study tests the exportability of a unique CCA tool to identify site-specific operational problems at 5 different VA teaching clinics.

DESIGN

We used the CCA tool at 5 teaching clinics to identify group preference differences between the above groups. We averaged the CCA results for all 5 sites. We compared each site with the averages in order to isolate each site's most anomalous responses. Major operational problems were independently identified by workgroups at each site. Cultural consensus analysis performance was then evaluated by comparison with workgroup results.

PARTICIPANTS

Twenty patients, 10 residents, 10 faculty, members, and 10 administrators at each site completed the CCA. Workgroups included at minimum: a patient, resident, faculty member, nurse, and receptionist or clinic administrator.

APPROACH

Cultural consensus analysis was performed at each site. Problems were identified by multidisciplinary workgroups, prioritized by anonymous multivoting, and confirmed by limited field observations and interviews. Cultural consensus analysis results were compared with workgroup results.

RESULTS

The CCA detected systematic, group-specific preference differences at each site. These were moderately to strongly associated with the problems independently identified by the workgroups. The CCA proved to be a useful tool for exploring the problems in depth and for detecting previously unrecognized problems.

CONCLUSIONS

This CCA worked in multiple VA sites. It may be adapted to work in other settings or to better detect other clinic problems.

Regulation of purine biosynthesis by a eukaryotic-type kinase in Streptococcus agalactiae

Group B streptococci (GBS) are the principal causal agents of human neonatal pneumonia, sepsis and meningitis. We had previously described the existence of a eukaryotic-type serine/threonine kinase (Stk1) and phosphatase (Stp1) in GBS that regulate growth and virulence of the pathogen. Our previous results also demonstrated that these enzymes reversibly phosphorylated an inorganic pyrophosphatase. To understand the role of these eukaryotic-type enzymes on growth of GBS, we assessed the stk1-mutants for auxotrophic requirements. In this report, we describe that in the absence of the kinase (Stk1), GBS are attenuated for de novo purine biosynthesis and are consequently growth arrested. During growth in media lacking purines, the intracellular G nucleotide pools (GTP, GDP and GMP) are significantly reduced in the Stk1-deficient strains, while levels of A nucleotides (ATP, ADP and AMP) are marginally increased when compared with the isogenic wild-type strain. We provide evidence that the reduced pools of G nucleotides result from altered activity of the IMP utilizing enzymes, adenylosuccinate synthetase (PurA) and IMP dehydrogenase (GuaB) in these strains. We also demonstrate that Stk1 and Stp1 reversibly phosphorylate and consequently regulate PurA activity in GBS. Collectively, these data indicate the novel role of eukaryotic-type kinases in regulation of metabolic processes such as purine biosynthesis.

Successful use of oral ganciclovir for the treatment of intrauterine cytomegalovirus infection in a renal allograft recipient

Congenital cytomegalovirus (CMV) infection occurs in approximately 1% of newborns and is the leading infectious cause of congenital birth defects. Female renal allograft recipients who develop CMV infection during pregnancy are at risk for both graft dysfunction and fetal morbidity. DNA-based analysis of amniotic fluid (AF) from at-risk pregnancies has been suggested as an adjunct/substitute for traditional culture. We have shown that CMV-polymerase chain reaction of AF is a useful diagnostic test for congenital CMV infection. Using this test we diagnosed CMV infection in the fetus of a 30-year-old renal transplant recipient. As termination was not an option for the family, the patient was extensively counseled and treated with oral ganciclovir. This resulted in clearance of the virus from the AF and the delivery of a healthy newborn girl, free of CMV disease. This is the first reported case to our knowledge of successful use of maternal ganciclovir to treat intrauterine CMV infection in a pregnant renal transplant recipient.

Reactive oxygen species promote tyrosine phosphorylation and capacitation in equine spermatozoa

The objective of this study was to examine the influence of reactive oxygen species (ROS) on equine sperm capacitation. Motile equine spermatozoa were separated on a discontinuous Percoll gradient, resuspended at 10 x 10(6)ml in Tyrode's medium supplemented with BSA (0.5%) and polyvinyl alcohol (0.5%) and incubated at 39 degrees C for 2h with or without the xanthine (X; 0.1mM)-xanthine oxidase (XO; 0.01 U/ml) system or NADPH (0.25 mM). The importance of hydrogen peroxide or superoxide for capacitation was determined by the addition of catalase (CAT; 150 U/ml) or superoxide dismutase (SOD; 150 U/ml), respectively. Following incubation, acrosomal exocytosis was induced by a 5 min incubation at 39 degrees C with progesterone (3.18 microM), and sperm viability and acrosomal integrity were then determined by staining with Hoechst 33258 and fluoroisothiocyanate-conjugated Pisum sativum agglutin. To examine tyrosine phosphorylation, treatments were subjected to sodium dodecyl sulfate-polyacrylaminde gel electrophoresis (SDS-PAGE) followed by Western blot analysis with the anti-phosphotyrosine antibody (alpha-PY; clone 4G10). Capacitation with the X-XO system or NADPH led to a significant (P<0.0001) increase in live acrosome-reacted spermatozoa compared to controls. The addition of CAT or SOD prevented the increase in live acrosome-reacted spermatozoa associated with X-XO treatment. Incubation with the X-XO system was also associated with a significant (P<0.005) increase in tyrosine phosphorylation when compared to controls, which could be prevented by the addition of CAT but not SOD. This study indicates that ROS can promote equine sperm capacitation and tyrosine phosphorylation, suggesting a physiological role for ROS generation by equine spermatozoa.

Intravenous immune globulin treatment inhibits crossmatch positivity and allows for successful transplantation of incompatible organs in living-donor and cadaver recipients

BACKGROUND

Sensitization to human leukocyte antigens (HLA) is a significant barrier to transplantation. Currently, no proven therapy exists to improve access to transplantation for highly sensitized patients. Here, we report a novel approach using intravenous immune globulin to modulate anti-HLA antibody and improve the chances for successful transplantation.

PATIENTS AND METHODS

Forty-five highly HLA-sensitized patients presented as candidates for living-donor kidney transplantation (n=28), cadaveric kidney transplantation (n=15), or heart transplantation (n=2). All patients had a positive CDC crossmatch (CMX) with their donors. In living-donor recipients, intravenous immune globulin (IVIG) was added to the CMX evaluation to determine whether blocking antibodies present in IVIG could inhibit cytotoxicity. For those who showed in vitro inhibition with IVIG (n=26), IVIG was administered (usually as a single dose, 2 g/kg) and the CDC CMX was repeated against the prospective donor immediately after IVIG infusion. If negative, the patient underwent transplantation with their living-donor kidney within 24 to 72 hr. A similar but modified protocol was performed for cadaver donor candidates, all of whom were highly sensitized and had had CMX positivity with multiple donors, negating transplantation. Reductions in CMX positivity, posttransplantation serum creatinine level, number and severity of rejection episodes, and patient and graft survival rates were determined.

RESULTS

Forty-two patients underwent transplantation. IVIG treatment completely abrogated the donor-specific CMXs in 35 of 42 patients. In the remaining 7 patients, the CDC CMX was inhibited, but flow cytometry CMXs remained positive. A total of 13 (31%) of 42 recipients developed rejection episodes 3 to 49 days after transplantation. Three grafts (7%) were lost to rejection. Mean serum creatinine level at 24 months was 1.4+/-0.4 mg/dL. Patient and graft survival rates were 97.6% and 89.1%, respectively, at 24 months.

CONCLUSIONS

The in vitro IVIG CMX technique predicts the ability of IVIG to reduce anti-HLA antibody levels in highly sensitized patients. Subsequent in vivo IVIG treatment of responders eliminates the positive CDC CMX and allows for successful transplantation. Thus a positive CMX result is not necessarily a contraindication for transplantation and allows access to transplantation for patients for whom it was previously contraindicated.

Early and pre-symptomatic neuropsychological dysfunction in the PPND family with the N279K tau mutation

The N279K mutation on the tau gene of chromosome 17 leads to an inherited condition that involves pallido-ponto-nigral degeneration (PPND). Patients with PPND develop dementia, but the pattern and onset of cognitive dysfunction has not yet been delineated. Four affected patients underwent neurocognitive evaluation within the first 2 years of PPND motor onset; one of whom underwent five serial neurocognitive evaluations, and another who was not diagnosed with PPND until the third annual evaluation. Impaired letter fluency was found in the early stages of PPND and was also shown to precede the onset of motor symptoms by 2 years. Trail Making A (visual scanning and motor speed) and Trail Making B (divided attention) were impaired within the first 2 years of the disease in all but one patient, but this individual showed clinically significant decline on these tasks by the third year of the disease. Learning, memory, and timed visuospatial sequencing skills were variably affected. Results reveal disproportionate frontal-executive dysfunction early in PPND disease course, a pattern similar to what has been reported in other FTDP-17 kindreds and in sporadic PSP. In addition, results suggest that letter fluency may be a sensitive predictor of incipient PPND.

Detection of lipid peroxidation in equine spermatozoa based upon the lipophilic fluorescent dye C1l-BODIPY581/591

The lipophilic fluorescent probe, 4,4-difluoro-5-(4-phenyl-1 ,3-butadienyl)-4-bora-3a,4a-diaza-s-indacene-3-undecanoic acid (C11-BODIPY581/591) was used to evaluate changes in lipid peroxidation in equine spermatozoa during both short-term exposure to ferrous sulfate and sodium ascorbate in the presence of cumene hydroperoxide as well as during storage of spermatozoa at 5 degrees C for 48 hours. Peroxidation of C11-BODIPY581/591 was accompanied by a shift in fluorescence from red to green, and the relative amount of nonoxidized probe was determined as the ratio of red:(red + green) fluorescence as detected by either fluorescence microplate reader or by flow cytometry. The addition of Fe2SO4 (0 to 0.5 mM), low concentrations of sodium ascorbate, and the addition of cumene hydroperoxide increased peroxidation of C11-BODIPY581/591. The addition of high concentrations (10 or 20 mM) of sodium ascorbate or alpha-tocopherol reduced peroxidation of C11-BODIPY581/591 during short-term incubations. During storage at 5 degrees C in a skim milk-based extender, equine spermatozoa demonstrated a progressive decline in motility and a small but significant increase in lipid peroxidation based upon ratiometric analysis of C11-BODIPY581/591. The addition of Fe2SO4 increased lipid peroxidation in cooled spermatozoa in a dose-dependent fashion and decreased sperm motility. The addition of alpha-tocopherol, however, did not reduce lipid peroxidation during cooled semen storage. These data demonstrate that the lipophilic fluorescent probe C11-BODIPY581/591 is a useful measurement of lipid peroxidation in equine spermatozoa and that there is an increase in lipid peroxidation during cooled storage of equine spermatozoa that is increased in the presence of ferrous promoters.

Generation of reactive oxygen species by equine neutrophils and their effect on motility of equine spermatozoa

Contaminating leukocytes in the ejaculate are an important source of reactive oxygen species (ROS) in human semen. When present in sufficient numbers, they can have a detrimental influence on sperm function in humans. Unfortunately, there is little published information regarding the importance of leukocytes in stallion semen. The objectives of this study were to determine the production of hydrogen peroxide (H2O2) by activated equine neutrophils and to examine the effect of this ROS production on equine sperm motility in vitro. Motile equine spermatozoa (two ejaculates each from four stallions) and peripheral blood neutrophils were isolated on discontinuous Percoll gradients, washed and resuspended in a modified Tyrode's medium. Spermatozoa (25 x 10(6)/ml) were incubated for 30 min at 38 C with neutrophils (0,0.5 x 10(6),1 x 10(6), 5 x 10(6) and 10 x 10(6)/ml) activated by either the protein kinase C agonist, 12-myristate, 13-acetate phorbol ester (PMA; 100 nM) or the leukocyte chemotactic peptide, formyl-methionyl-leucyl-phenylalanine (FMLP; 0.1 mM). Sperm motility was determined by computer-assisted semen analysis (CASA) at time 0 min (T0) and time 30 min (T30), and H2O2 was measured at T30 with the Amplex Red assay kit. At T30, there was a significant (P < 0.01) increase in H2O2 with the addition of 5 x 10 and 10 x 10(6) neutrophils/ml activated by FMLP (0.76 +/- 0.3 and 0.99 +/- 0.4 microM, respectively, versus 0.0024 +/- 0.002 microM in sperm alone), and this increase was associated with a significant (P < 0.001) decrease in total motility (52 +/- 5.1 and 48 +/- 6.0%, respectively, versus 80 +/- 4.7% in sperm alone). At T30, there was also a significant (P < 0.001) increase in H2O2 with the addition of 5 x 10(6) and 10 x 10(6) neutrophils/ml activated by PMA (1.88 +/- 0.2 and 2.07 +/- 0.3 microM, respectively, versus 0.0009 +/- 0.0006 microM in sperm alone). The results of this study demonstrate that 5 x 10(6) activated neutrophils/ml are sufficient to impair equine sperm motility in vitro.

Osmotic tolerance of equine spermatozoa and the effects of soluble cryoprotectants on equine sperm motility, viability, and mitochondrial membrane potential

Osmotic stress attributed to differences in the relative permeability of cryoprotectants, such as glycerol and water, appears to be an important factor in cryodamage. The objective of this study was to characterize the osmotic tolerance of equine spermatozoa, and to evaluate the effects of addition and removal of cryoprotectants from equine spermatozoa on their motility, and membrane and acrosomal integrity, as well as their mitochondrial membrane potential. Equine spermatozoa had a limited osmotic tolerance to anisosmotic conditions. Although the addition of increasing concentrations of glycerol decreased the motility and viability of equine spermatozoa, the rapid removal of glycerol by dilution in isosmotic media resulted in an even greater decline in motility and viability compared with spermatozoa maintained under anisosmotic conditions. Likewise, the addition and rapid removal of 1.0 M glycerol, ethylene glycol, dimethylsulfoxide, or propylene glycol resulted in a significant decline in sperm motility and viability. Among these cryoprotectants, ethylene glycol had the least detrimental effect on either viability or motility of spermatozoa following the rapid addition and removal of these cryoprotectants. These data demonstrate that equine spermatozoa have a limited osmotic tolerance compared with published reports for mouse or human spermatozoa, and appear to be more similar to boar spermatozoa in their osmotic tolerance. Of the 4 cryoprotectants evaluated in equine spermatozoa, the addition and removal of glycerol resulted in a more marked osmotic stress as indicated by alterations in motility, viability, and acrosomal integrity. These data suggest that alternative cryoprotectants should be considered for cryopreservation of equine spermatozoa in order to reduce osmotic stress associated with the addition of these agents during semen freezing.

An expressed neo(r) cassette provides required functions of the 1gamma2b exon for class switching

Germline CH transcripts initiate from a promoter upstream of a non-coding I exon, proceed through the switch (S) region and terminate downstream of the associated CH exons. To elucidate the role of germline transcription in Ig heavy chain class switch recombination (CSR), we used gene targeting in embryonic stem (ES) cells to replace most of the Igamma2b exon from immediately 3' of the majority of transcription initiation sites to beyond its donor splice site with a PGK-neo(r)gene inserted in the same transcriptional orientation as the endogenous unit. The mutation was introduced into both alleles of ES cell lines (referred to as gamma2-b(N/N)) and the neo(r) gene was deleted (referred to as Igamma2b-/-) by the loxP/Cre method. These mutations were assayed for effects on CSR in B cells derived via RAG-2-deficient blastocyst complementation. Igamma2b-/- B cells lacked ability to switch to IgG2b both in vivo and in vitro, and, correspondingly, showed no germline transcription through the Igamma2b exon, Sgamma2b or the Cgamma2b region. In contrast, Igamma2b(N/N) B cells switched at normal levels to IgG2b and showed substantial transcription through the Sgamma2b and Cgamma2b regions. Taken together, these results show that the Igamma2b sequences, per se, are not necessary for mediating CSR since a transcribed PGK-neo(r) gene can replace its function. However, the deleted portion of the Igamma2b exon and splice donor site apparently contain sequences necessary for efficient germline gene transcription and thus for CSR to IgG2b.

FK 506 'rescue' immunosuppression for obliterative bronchiolitis after lung transplantation

PRELIMINARY EXPERIENCE

In a consecutive case series (level V evidence) involving 10 recipients of unilateral lung transplantation (LT) with bronchiolitis obliterans, in conjunction with Fujisawa protocol 93-0-003, the physiologic responses to FK 506 (tacrolimus) "rescue" immunosuppression were assessed. Recipients were 22+/-18 months post-LT and demonstrated progressive allograft dysfunction that was refractory to pulsed-dose methylprednisolone therapy. All recipients received induction immunosuppression with Minnesota antilymphocyte globulin (10 to 15 mg/kg/d) for 5 to 10 days, cyclosporine (CsA) (whole-blood Abbott TDX fluorescence polarization immunoassay (Abbott Inc, Abbott Park, IL)=600 to 800 ng/mL), azathioprine (2 mg/kg/d), and prednisone (tapered to 0.2 mg/kg/d). The "rescue" regimen consisted of oral FK 506 adjusted to maintain a whole-blood Abbott IMX microparticle enzyme immunoassay (Abbott Inc, Abbott Park, IL) of 10 to 15 ng/mL with an initial increase in prednisone (1.0 mg/kg/d) during conversion that was subsequently tapered to 0.2 mg/kg/d. Spirometry was performed monthly in accordance with accepted American Thoracic Society criteria. Recipients were classified in accordance with the International Society for Heart and Lung Transplantation (ISHLT) "Working Formulation for Standardization of Nomenclature and for Clinical Staging of Chronic Dysfunction in Lung Allografts" as stages Ib (n=2), IIb (n=4), and IIIb (n=4) upon entry to the protocol. The deltaFEV1/month relationships during CsA- and FK 506-based regimens were analyzed by linear regression and compared by signed rank test (p<0.05).

RESULTS

The deltaFEV1/month slopes were -0.0687+/-0.0221 and +0.0300+/-0.033 L/mo (mean+/-SEM) for CsA and FK 506, respectively (p=0.037). Although no significant spirometric improvement was noted in most recipients, no further decline in FEV1 occurred after conversion to FK 506. Recipients with less severe chronic dysfunction (ie, obliterative bronchiolitis [OB] stages Ib and IIb) stabilized their spirometric indexes at higher levels. Two recipients with OB stage IIIb died of hypercapnic respiratory failure at 6 and 8 months after conversion.

CONCLUSIONS

The deltaFEV1/mo slopes stabilized after FK 506 conversion. Earlier conversion may be beneficial in stabilizing FEV1 at a higher plateau. Significant economic impact may be anticipated with FK 506 compared to alternative cytolytic strategies for OB. However, multicenter prospective controlled investigations are necessary to further address the potential role of FK 506 after LT (level I evidence). Furthermore, the ISHLT "Staging of OB Syndrome" may have significant clinical implications vis-à-vis prognosis and potential therapies.