Association between Bioimpedance Spectroscopy and Magnetic Resonance Lymphangiography in the Diagnosis and Assessment of Lymphedema

BACKGROUND

 This study assesses associations between bioimpedance spectroscopy (BIS) and magnetic resonance lymphangiography (MRL) in the staging and assessment of lymphedema.

METHODS

 Adults who received MRL and BIS between 2020 and 2022 were included. We collected fluid, fat, and lymphedema severity ratings, and measured fluid stripe thickness, subcutaneous fat width, and lymphatic diameter on MRL. BIS lymphedema index (L-Dex) scores were collected from patient charts. We assessed sensitivity and specificity of L-Dex scores to detect MRL-identified lymphedema, and examined associations between L-Dex scores and MRL imaging measures.

RESULTS

 Forty-eight limbs across 40 patients were included. L-Dex scores had 72.5% sensitivity and 87.5% specificity for detecting MRL-defined lymphedema, with a 96.7% estimated positive predictive value and 38.9% negative predictive value. L-Dex scores were associated with MRL fluid and fat content scores (p ≤ 0.05), and lymphedema severity (p = 0.01), with better discrimination between fluid than fat content levels on pairwise analysis, and poor discrimination between adjacent severity levels. L-Dex scores were correlated with distal and proximal limb fluid stripe thickness (distal: rho = 0.57, p < 0.01; proximal: rho = 0.58, p < 0.01), partially correlated with distal subcutaneous fat thickness when accounting for body mass index (rho = 0.34, p = 0.02), and were not correlated with lymphatic diameter (p = 0.25).

CONCLUSION

 L-Dex scores have high sensitivity, specificity, and positive predictive value for the identification of MRL-detected lymphedema. L-Dex has difficulty distinguishing between adjacent severity levels of lymphedema and a high false negative rate, explained in part by reduced discrimination between levels of fat accumulation.

Technical Variables in Lower Extremity Free Flap Reconstruction

BACKGROUND

 Lower extremity free flap failure rates are higher than in other areas of the body. While prior studies assessed the effect of intraoperative technical variables, these generally investigated individual variables and did not examine relationships between the many individual technical decisions made during free tissue reconstruction. Our purpose was to investigate the effect of variation in intraoperative microsurgical techniques on flap outcomes in a diverse cohort of patients requiring lower extremity free flap coverage.

METHODS

 Consecutive patients undergoing free flap reconstruction of the lower extremity at two level 1 trauma centers from January 2002 to January 2020 were identified using Current Procedural Terminology codes, followed by a review of medical records. Information regarding demographics and comorbidities, indications, intraoperative technical details, and complications was collected. Outcomes of interest included an unplanned return to the operating room, arterial thrombosis, venous thrombosis, partial flap failure, and total flap failure. Bivariate analysis was performed.

RESULTS

 In total, 410 patients underwent 420 free tissue transfers. The median follow-up time was 17 months (interquartile ranges: 8.0-37). Total flap failure occurred in 4.9% (n = 20), partial flap failure in 5.9% (n = 24), and unplanned reoperation in 9.0% (n = 37), with arterial thrombosis in 3.2% (n = 13) and venous thrombosis in 5.4% (n = 22). Overall complications were significantly associated with recipient artery choice, with arteries other than PT and AT/DP having a higher rate (p = 0.033), and with arterial revisions (p = 0.010). Total flap failure was also associated with revision of the arterial anastomosis (p = 0.035), and partial flap failure was associated with recipient artery choice (p = 0.032).

CONCLUSION

 Many interoperative options and techniques are available when performing microvascular lower extremity reconstruction that leads to equally high success rates. However, the use of arterial inflow outside of the posterior tibial and anterior tibial arteries leads to a higher overall complication rate and partial flap failure rate. Intraoperative revision of the arterial anastomosis portends poorly for ultimate flap survival.

Secondary Surgery after Lower Extremity Free Flap Reconstruction

BACKGROUND

Microsurgical free tissue transfer may be the only reconstructive option for lower extremity limb salvage. However, the functional and aesthetic results following free tissue transfer after initial salvage may be suboptimal, thus requiring secondary operations to facilitate definitive wound healing and/or refinement.

METHODS

A multi-institutional retrospective cohort study was performed including patients who underwent lower extremity free tissue transfer from January of 2002 to December of 2020. The authors' primary outcome variable was the presence of secondary surgery after free tissue transfer for lower extremity reconstruction. Independent variables (eg, wound cause, flap, donor type, recipient, comorbidities) were collected. Secondary surgery was categorized as (1) procedures for definitive wound closure and (2) refinement procedures. Multivariable logistic regression was performed to determine which variables were independently associated with the outcome.

RESULTS

A total of 420 free tissue transfers for lower extremity reconstruction were identified. Secondary surgery was performed in over half (57%) of the patients. Presence of diabetes (OR, 2.0; P = 0.01; 95% CI, 1.2 to 3.5) and use of a latissimus dorsi donor (OR, 2.4; P = 0.037; 95% CI, 1.1 to 5.4) were predictors of wound closure procedures. Fasciocutaneous (OR, 3.6; P < 0.001; 95% CI, 1.8 to 7.2) and myocutaneous (OR, 3.0; P = 0.005; 95% CI, 1.5 to 9.9) flaps were predictors of refinement procedures when compared with muscle-only flaps with skin grafts.

CONCLUSIONS

The majority of lower extremity free tissue reconstructions required secondary procedures to provide definitive wound closure and/or refinement. Overall, this study provides predictors of secondary surgery that will help formulate patients' expectations of lower extremity limb salvage.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Risk, III.

Investigating Weekend Effect in the Management of Upper and Lower Extremity Degloving Injuries

Background

Weekend presentation has been associated with adverse outcomes in emergent conditions, including stroke, myocardial infarction, and critical limb ischemia. We examine whether a weekend effect exists in the management of and outcomes after extremity degloving injuries.

Methods

The cohort included adults presenting with open extremity degloving injuries to a tertiary level one trauma center between June 2018 and May 2022. We collected demographics, comorbidities, injury information, interventions, and complications. Propensity score weighting was used to minimize confounding differences between those presenting on weekends (Sat-Sun) versus weekdays (Mon-Fri). Weighted regressions were used to examine differences in interventions by day of presentation. Multivariable weighted regressions accounting for differences in interventions received were used to examine whether weekend presentation was associated with amputation risk, complications, or functional deficits.

Results

Ninety-five patients with 100 open extremity degloving injuries were included. In total, 39% of injuries were weekend-presenting. There was a higher rate of noninsulin-dependent diabetes among patients presenting on weekends (P = 0.03). Weekend-presenting injuries had higher median Injury Severity Scores (P = 0.04). Propensity-weighted regression analysis revealed differences in interventions received on weekends, including lower rates of pedicled and free flaps and bone graft, and increased rates of negative-pressure wound therapy (P ≤ 0.02). Multivariable regression analysis revealed weekend presentation was a significant independent risk factor for amputation of the affected extremity [odds ratio 2.27, 95% CI (1.01-5.33), P = 0.05].

Conclusion

Weekend presentation may impact interventions received and amputation risk in patients presenting with open extremity degloving injuries.

Compound Effect of Hypoalbuminemia and Obesity on Complications after Autologous Breast Reconstruction

BACKGROUND

Obesity is among the risk factors identified that impair postoperative wound healing. Recently, malnutrition and sarcopenia have also been found to correlate with poor surgical outcomes; however, the effect of malnutrition in the setting of obesity is understudied, particularly in reconstructive surgery. The authors examine the American College of Surgeons National Surgery Quality Improvement Program database to determine the impact of obesity plus hypoalbuminemia on complications after autologous breast reconstruction.

METHODS

Autologous breast reconstruction procedures (pedicled and free flaps) were collected from the 2009 to 2019 National Surgery Quality Improvement Program databases by CPT codes ( n = 23,690). Patients without height, weight, or preoperative serum albumin data ( n = 12,825) were excluded. Demographics and postoperative outcomes were compared in patients with obesity (body mass index >30 kg/m 2 ) and malnutrition (albumin <3.5 g/dL). Propensity score-matched cohorts with and without malnutrition were also compared.

RESULTS

A total of 10,865 procedures were included in analysis; 4565 involved patients with obesity (42%). Obesity was associated with increased length of stay, reoperations, wound complications, and medical complications (all P < 0.001). Among patients with obesity, 198 had malnutrition (4.3%). The combination of obesity and malnutrition was associated with a higher rate of wound complications (16%) over obesity alone (9.2%) or malnutrition alone (9.2%, both P < 0.05). This difference is recapitulated in propensity score-matched analysis.

CONCLUSION

Hypoalbuminemia, a marker of malnutrition, is underappreciated in obese patients and is associated with worse surgical outcomes after autologous breast reconstruction compared with obesity alone.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Risk, II.

Point-of-Care Tissue Oxygenation Assessment with SnapshotNIR for Alloplastic and Autologous Breast Reconstruction

In breast reconstruction, mastectomy and free flaps are susceptible to vascular compromise and tissue necrosis. The SnapshotNIR device (Kent Imaging, Calgary, AB, Canada) utilizes near-infrared spectroscopy to measure tissue oxygen saturation (StO₂) and hemoglobin concentration. Here, we report on the use of this device for StO₂ monitoring among patients receiving alloplastic or autologous breast reconstruction.

Methods

Patients receiving immediate alloplastic reconstruction after mastectomy or autologous reconstruction were enrolled. Preoperative, intraoperative, and postoperative images were taken of the flaps. StO₂ and hemoglobin were measured at the following locations: superior and inferior breast, free flap skin paddle (when applicable), and un-operated control skin. Linear mixed effects model for repeated measurements was used to model measurements to estimate the area effect difference across time, time effect difference across area, and pairwise comparisons between two areas at each time point.

Results

Thirty-two breasts underwent alloplastic reconstruction; 38 breasts underwent autologous reconstruction. No enrollees developed skin necrosis. StO₂ was highest after mastectomy and closure in alloplastic reconstructions. StO₂ was observed to decline at follow-up in autologous reconstructions. Mean preoperative StO₂ was highest in breasts that had previously undergone mastectomy and alloplastic reconstruction.

Conclusions

The SnapshotNIR device detected normal spatial and temporal differences in tissue oxygenation over the operative course of alloplastic and autologous breast reconstruction. A multi-institutional, prospective clinical trial is needed to determine the sensitivity and specificity of this device for detecting skin flap necrosis.

Secondary amputation after lower extremity free-flap reconstruction

BACKGROUND

Microsurgical free-tissue transfer is often the definitive reconstructive option for lower extremity limb salvage. Despite an initial successful free-flap reconstruction, some patients ultimately undergo lower extremity amputation. The indications for secondary amputation include non- or malunion, infection, hardware failure, or chronic pain. This study aimed to identify the etiology and outcome of secondary amputation after lower extremity free-flap reconstruction.

METHODS

A retrospective cohort study was performed including patients who underwent lower extremity free-flap reconstruction from January 2002 to December 2020. Patients who underwent secondary amputation were identified. A survey based on the PROMIS® Pain Interference Scale and activities of daily living (ADLs) was then conducted to assess patient-reported outcomes. Fifteen (52%) patients who underwent amputation responded to the survey, with a median follow-up time of 4.4 years.

RESULTS

Of 410 patients who underwent lower extremity free-flap reconstruction, 40 (9.8%) patients underwent subsequent amputation. Of these, 10 patients had failed free-flap reconstruction and 30 patients had secondary amputation after an initially successful soft tissue coverage. The most common etiology for secondary amputation was infection (68%, n = 27). Eighty percent (n = 12) of survey respondents were able to use a prosthetic limb and ambulate.

CONCLUSIONS

The most common etiology of secondary amputation was infection. Most patients who ultimately underwent amputation were able to ambulate with a prosthetic, but the majority of patients reported chronic pain. This study could be used to guide potential free-flap candidates regarding the risks and outcomes of lower extremity free-flap reconstruction.

The Association between Breast Cancer Related Lymphedema and Area Deprivation Index

Background Lymphedema affects up to 34% of patients after breast cancer treatment but remains underdiagnosed and undertreated. Here, we use area deprivation index (ADI), a measure of neighborhood socioeconomic disadvantage, to determine how socioeconomic status may affect risk for and diagnosis of breast cancer-related lymphedema. Methods Records of patients who underwent surgical treatment of breast cancer between 2017-2020 were examined. Patients' nine-digit ZIP codes were utilized to determine their deprivation level as a national ADI percentile, and those fitting into the most and least deprived quartiles were compared to evaluate lymphedema risk factors and incidence. Results A total of 1,333 breast cancer patients were included, 812 (61%) of whom resided within the most disadvantaged ADI quartile nationally, and 521 within the least disadvantaged quartile. The most deprived group had higher rates of diabetes, obesity, and regional breast cancer, and received more extensive surgeries (7.5% modified radical mastectomy vs 1.9%, p<0.001) and chemotherapy compared to the least disadvantaged quartile. The most disadvantaged cohort were more often at extreme risk of lymphedema utilizing the Risk Assessment Tool Evaluating Lymphedema Risk (9.1% vs. 2.5%, p<0.001); however, the incidence of lymphedema diagnoses was not significantly higher (13% vs 12%, p>0.9). Logistic regression showed that the most deprived ADI quartile had 44% lower odds of a lymphedema diagnosis in comparison to the least deprived quartile. Conclusions Residing in more socioeconomically disadvantaged neighborhoods is associated with lower odds of a lymphedema diagnosis, despite higher rates of risk factors for lymphedema, suggesting significant underdiagnosis in this population.

The impact of the COVID-19 pandemic on alloplastic breast reconstruction: An analysis of national outcomes

Background

Immediate alloplastic breast reconstruction shifted to the outpatient setting during the COVID‐19 pandemic to conserve inpatient hospital beds while providing timely oncologic care. We examine the National Surgical Quality Improvement Program (NSQIP) database for trends in and safety of outpatient breast reconstruction during the pandemic.

Methods

NSQIP data were filtered for immediate alloplastic breast reconstructions between April and December of 2019 (before‐COVID) and 2020 (during‐COVID); the proportion of outpatient procedures was compared. Thirty‐day complications were compared for noninferiority between propensity‐matched outpatients and inpatients utilizing a 1% risk difference margin.

Results

During COVID, immediate alloplastic breast reconstruction cases decreased (4083 vs. 4677) and were more frequently outpatient (31% vs. 10%, p < 0.001). Outpatients had lower rates of smoking (6.8% vs. 8.4%, p = 0.03) and obesity (26% vs. 33%, p < 0.001). Surgical complication rates of outpatient procedures were noninferior to propensity‐matched inpatients (5.0% vs. 5.5%, p = 0.03 noninferiority). Reoperation rates were lower in propensity‐matched outpatients (5.2% vs. 8.0%, p = 0.003).

Conclusion

Immediate alloplastic breast reconstruction shifted towards outpatient procedures during the COVID‐19 pandemic with noninferior complication rates. Therefore, a paradigm shift towards outpatient reconstruction for certain patients may be safe. However, decreased reoperations in outpatients may represent undiagnosed complications and warrant further investigation.

National Outcomes of Prophylactic Lymphovenous Bypass during Axillary Lymph Node Dissection

BACKGROUND

 Breast cancer treatment, including axillary lymph node excision, radiation, and chemotherapy, can cause upper extremity lymphedema, increasing morbidity and health care costs. Institutions increasingly perform prophylactic lymphovenous bypass (LVB) at the time of axillary lymph node dissection (ALND) to reduce the risk of lymphedema but reports of complications are lacking. We examine records from the American College of Surgeons (ACS) National Surgery Quality Improvement Program (NSQIP) database to examine the safety of these procedures.

METHODS

 Procedures involving ALND from 2013 to 2019 were extracted from the NSQIP database. Patients who simultaneously underwent procedures with the Current Procedural Terminology (CPT) codes 38999 (other procedures of the lymphatic system), 35201 (repair of blood vessel), or 38308 (lymphangiotomy) formed the prophylactic LVB group. Patients in the LVB and non-LVB groups were compared for differences in demographics and 30-day postoperative complications including unplanned reoperation, deep vein thrombosis (DVT), wound dehiscence, and surgical site infection. Subgroup analysis was performed, controlling for extent of breast surgery and reconstruction. Multivariate logistic regression was performed to identify predictors of reoperation.

RESULTS

 The ALND without LVB group contained 45,057 patients, and the ALND with LVB group contained 255 (0.6%). Overall, the LVB group was associated with increased operative time (288 vs. 147 minutes, p < 0.001) and length of stay (1.7 vs. 1.3 days, p < 0.001). In patients with concurrent mastectomy without immediate reconstruction, the LVB group had a higher rate of DVTs (3.0 vs. 0.2%, p = 0.009). Reoperation, wound infection, and dehiscence rates did not differ across subgroups. Multivariate logistic regression showed that LVB was not a predictor of reoperations.

CONCLUSION

 Prophylactic LVB at time of ALND is a generally safe and well-tolerated procedure and is not associated with increased reoperations or wound complications. Although only four patients in the LVB group had DVTs, this was a significantly higher rate than in the non-LVB group and warrants further investigation.

Measurement Properties of the Lymphedema Life Impact Scale

Background: The updated Lymphedema Life Impact Scale (LLIS, version 2) has been widely used to evaluate the effect of lymphedema from the patient's perspective. We sought to assess its ability to accurately and efficiently measure lymphedema-related impact using modern psychometric techniques. Methods and Results: We collected a total of 1054 patient-reported outcome measure scores from 285 patients with upper extremity lymphedema and 65 patients with lower extremity lymphedema between 2016 and 2020. We first evaluated the relationship between the LLIS score, L-Dex score, and limb volume difference (LVD), and used classical test and item response theories to assess its psychometric performance. The LLIS score was only very weakly associated with LVD (r = 0.17, p < 0.001) and L-Dex score (r = 0.22, p < 0.001). The LLIS had acceptable dimensionality. Items 7 (affects body image) and 16 (affects proper fit of clothing/shoes) were locally dependent (Yen's Q3 = 0.45). Eight of the 17 items was interpreted differently between upper and lower limb lymphedema patients (pseudo R² ≥ 0.01). The scoring structure required correction for items 9 (affects intimate relations) and 12 (manages lymphedema). Removing items 18 (infection occurrence) and 7 resulted in substantially improved item response theory model fit (Tucker-Lewis index = 0.93, comparative fix index = 0.95, root mean square error of approximation = 0.07, and root means square of the residual = 0.06). The relationships between the LLIS and objective measures of lymphedema remained weak following modification (LVD; r = 0.13, p = 0.01, L-Dex; r = 0.26, p < 0.001). Conclusion: We were able to slightly improve the psychometric properties of the LLIS. However, these improvements did not rectify apparent issues with construct validity and both versions of the LLIS displayed a weak relationship with objective measures of lymphedema severity.

Rhinopharynx irrigations and mouthwash with dissolved mupirocin in treatment of MRSA throat colonization - proof-of-concept study

BACKGROUND

To prevent transmission of, and infection with, meticillin-resistant Staphylococcus aureus (MRSA), eradication treatment of colonized individuals is recommended. Throat colonization is a well-known risk factor for eradication failure. Staphylococcus aureus throat colonization is associated with colonization of the rhinopharynx, but in the currently recommended Danish MRSA eradication strategies, rhinopharynx colonization is not directly targeted. Rhinopharynx colonization could therefore be an important risk factor for prolonged MRSA throat carriage.

AIM

To determine whether irrigation and wash of the rhinopharynx and mouth with dissolved mupirocin is a feasible and potentially efficacious supplementary strategy against treatment-resistant MRSA throat carriage.

METHODS

The patient study was an open, non-blinded, trial including 20 treatment-resistant MRSA throat carriers. In the study, the patients received a supplementary treatment besides the standard treatment according to the Danish MRSA eradication strategy. The supplementary treatment consisted of rhinopharyngeal irrigation and mouth-gurgling twice a day for 14 days with a mupirocin ointment (22 g 2% ointment per litre of isotonic sterile saline solution) in a 37°C solution.

FINDINGS

Eighteen patients (90%) complied with the treatment protocol and none ex-perienced any major adverse events. Out of the 18 patients who finished the study per protocol, 15 (83%) and seven (39%) patients had negative MRSA sampling results one and six months after end of treatment, respectively.

CONCLUSION

This study demonstrates the feasibility and clinical potential of also targeting the rhinopharynx and oropharynx in non-systemic throat MRSA eradication strategies.

Genetic parameters for reproductive losses estimated from in-line milk progesterone profiles in Swedish dairy cattle

This study assessed the extent of reproductive losses and associated genetic parameters in dairy cattle, using in-line milk progesterone records for 14 Swedish herds collected by DeLaval's Herd Navigator. A total of 330,071 progesterone samples were linked to 10,219 inseminations (AI) from 5,238 lactations in 1,457 Swedish Red and 1,847 Swedish Holstein cows. Pregnancy loss traits were defined as early embryonic loss (1-24 d after AI), late embryonic loss (25-41 d after AI), fetal loss (42 d after AI until calving), and total pregnancy loss (from d 1 after AI until calving). The following classical fertility traits were also analyzed: interval from calving to first service, interval from calving to last service, interval between first and last service, calving interval, and number of inseminations per service period. Least squares means with standard error (LSM ± SE), heritabilities, and genetic correlations were estimated in a mixed linear model. Fixed effects included breed, parity (1, 2, ≥3), estrus cycle number when the AI took place, and a linear regression on 305-d milk yield. Herd by year and season of AI, cow, and permanent environmental effect were considered random effects. Extensive (approximately 45%) early embryonic loss was found, but with no difference between the breeds. Swedish Red was superior to Swedish Holstein in the remaining pregnancy loss traits with, respectively: late embryonic loss of 6.1 ± 1.2% compared with 13.3 ± 1.1%, fetal loss of 7.0 ± 1.2% compared with 12.3 ± 1.2%, and total pregnancy loss of 54.4 ± 1.4% compared with 60.6 ± 1.4%. Swedish Red also had shorter calving to first service and calving to last service than Swedish Holstein. Estimated heritability was 0.03, 0.06, and 0.02 for early embryonic, late embryonic, and total pregnancy loss, respectively. Milk yield was moderately genetically correlated with both early and late embryonic loss (0.52 and 0.39, respectively). The pregnancy loss traits were also correlated with several classical fertility traits (-0.46 to 0.92). In conclusion, Swedish Red cows had lower reproductive loss during late embryonic stage, fetal stage, and in total, and better fertility than Swedish Holstein cows. The heritability estimates for pregnancy loss traits were of the same order of magnitude as previously reported for classical fertility traits. These findings could be valuable in work to determine genetic variation in reproductive loss and its potential usefulness as an alternative fertility trait to be considered in genetic or genomic evaluations.

Webinar during COVID-19 Improves Knowledge of Changes to the Plastic Surgery Residency Application Process

BACKGROUND

The COVID-19 pandemic has significantly impacted residency application process for all specialties, including plastic surgery residency. Almost all plastic surgery residency programs have suspended visiting sub-internship rotations. This study quantifies the impact of a webinar through an analysis of poll questions and a post-webinar survey sent to all registered participants.

METHODS

A dedicated webinar was organized and held by the Harvard Plastic Surgery Residency Training Program. All attendees were asked several poll questions during the webinar. The 192 participants were also sent a post-webinar survey.

RESULTS

The response rate was 68.2% (n = 131). Respondents were more confident about matching into a plastic surgery residency program at the end of the webinar compared with before the webinar (P < 0.001). Respondents who did not have a plastic surgery residency program at their home institution were less confident at the start of the webinar (P = 0.009). In addition, respondents who had not taken time off for research or for other endeavors during or after medical school were less confident about their chances to match at the start of the webinar (P = 0.034).

CONCLUSIONS

An online webinar program increased confidence levels of medical students interested in applying for residency positions in plastic surgery. Residency programs should consider webinars as a method to inform and assist medical students during the upcoming application season.

Multidisciplinary Treatment to Restore Vision in Ocular Burns

Periorbital burns generate contraction and distortion of periorbital soft tissue, causing eyelid malfunction, further contributing to loss of vision from corneal scarring or perforation. We present our multidisciplinary algorithm to restore vision in patients with burn-related bilateral corneal blindness with light perception. Chart review was performed for four consecutive burn patients requiring periocular reconstruction and keratoprosthesis. Initial treatment included globe coverage with eyelid releases and grafts. Strategy of corneal replacement was determined by eyelid position and function and sufficiency of tear production. All patients were corneal blind with light perception only and cicatricial ectropion. The eye with better visual prognosis was reconstructed. Eyelid reconstruction procedures consisted of lid releases with full-thickness skin graft (FTSG) or split-thickness skin graft (STSG). Two patients regained adequate lid function and underwent standard keratoprosthesis placement. Two underwent mucous membrane grafts followed by keratoprosthesis. All patients experienced improved postoperative vision in their reconstructed eye. Corneal injury due to periocular burns can lead to blindness. Early involvement of ophthalmology, protective measures, and early ectropion release are critical. For severe burns, a multidisciplinary approach, where adequate globe protection is followed by keratoprosthesis placement, can effectively restore vision in patients with burn-related corneal blindness.

Genetic parameters of endocrine fertility traits based on in-line milk progesterone profiles in Swedish Red and Holstein dairy cows

Evaluating fertility traits based on endocrine progesterone profiles is becoming a promising option to improve dairy cow fertility. Several studies have been conducted on endocrine fertility traits, mainly in the Holstein breed. In this study, focusing also on the Swedish Red (SR) breed, genetic parameters were estimated for classical and endocrine fertility traits, the latter based on in-line milk progesterone records obtained for 14 Swedish herds using DeLaval Herd Navigator (DeLaval International, Tumba, Sweden). A total of 210,403 observations from 3,437 lactations of 1,107 SR and 1,538 Holstein cows were used. Mixed linear animal models were used for estimation of genetic parameters. Least squares means analysis showed that Holstein cows had a 2.5-d-shorter interval from calving to commencement of luteal activity (C-LA) and longer length of first inter-ovulatory interval (IOI) than SR cows. The highest mean interval for C-LA, IOI, and first luteal phase length (LPL) was observed in the fourth parity. The incidence of short (<18 d), normal, (18-24 d), and long (>24 d) IOI was 29.3, 40.7, and 30%, respectively. Genetic analysis indicated moderate heritability (h²) for C-LA (h² = 0.24), luteal activity during the first 60 d in milk (LA60, h² = 0.15), proportion of samples with luteal activity (PLA, h² = 0.13), and calving to first heat (CFH, h² = 0.18), and low heritability estimates for LPL (h² = 0.08) and IOI (h² = 0.03) in the combined data set for both breeds. Similar heritability estimates were obtained for each breed separately except for IOI and LPL in SR cows, for which heritability was estimated to be zero. Swedish Red cows had 0.01 to 0.06 higher heritability estimates for C-LA, LA60, and PLA than did Holstein cows. Calving interval had moderate heritability among the classical traits for Holstein and the combined data set, but h² was zero for SR. Commencement of luteal activity had a strong genetic correlation with LA60 (mean ± SE; -0.88 ± 0.06), PLA (-0.72 ± 0.11), and CFH (0.90 ± 0.04). Similarly, CFH had a strong genetic correlation with IOI (0.98 ± 0.20). Number of inseminations per series showed a weak genetic correlation with all endocrine traits except IOI. Overall, endocrine traits had higher heritability estimates than classical traits in both breeds, and may have a better potential to explain the actual reproductive status of dairy cows than classical traits. This might favor inclusion of some endocrine fertility traits-especially those related to commencement of luteal activity-as selection criteria and breeding goal traits if recording becomes more common in herds. Further studies on genetic and genomic evaluations for endocrine fertility traits may help to provide firm conclusions. A prerequisite is that the data from automatic devices be made available to recording and breeding organizations in the future and included in a central database.

Danish experience of meticillin-resistant Staphylococcus aureus eradication with emphasis on nose-throat colonization and supplementary systemic antibiotic treatment

This study aimed to evaluate the Danish Board of Health's guidance for treating the carriage of meticillin-resistant Staphylococcus aureus (MRSA), focusing on nose-throat carriage and use of supplementary systemic antibiotics. The results of MRSA eradication treatment among 358 patients were analysed, focusing on those with nose (N=58) or throat (N=183) MRSA colonization. The Danish guidance for MRSA treatment was found to be more successful in patients with nose colonization (66%) compared with throat colonization (41%), despite the fact that the cumulative eradication rates were equal after three treatment cycles (71% vs 73%). This study found that supplementation of colonization treatment with systemic antibiotics does not have a positive effect.

Characteristics of macrolide responders in persistent post-surgical rhinosinusitis

INTRODUCTION

The anti-inflammatory effects of long term low dose macrolide therapy have shown benefit in the management of diffuse panbronchiolitis. Dramatic responses to macrolide in the upper airway are seen but our understanding of the patient phenotype predisposing to macrolide response in chronic rhinosinusitis (CRS) is poor.

METHODS

A case control study was performed in a tertiary level rhinology practice of consecutive chronic rhinosinusitis patients placed on a 3-month low dose macrolide therapy after failing at least 3 months of corticosteroid irrigation therapy post-endoscopic sinus surgery. Patients were defined as a macrolide responder when having near normal endoscopy after a 3-month period of clarithromycin treatment. Patient characteristics of smoking, asthma, atopy status, revision surgery, symptom severity (SNOT-22) along with biomarkers from serum and tissue histopathology results were compared between groups.

RESULTS

Of twenty-eight consecutive macrolide treated patients, 19 responders were compared to 9 non-responders. The groups were similar in age, female gender, non-smoking, asthma, and atopy. Macrolide response was associated with a lack of tissue eosinophilia (more than 10/HPF) and lower serum eosinophilia. Neutrophil expression was similar in tissue and serum. Squamous metaplasia was overexpressed in non-responders.

CONCLUSION

Low tissue and serum eosinophilia, and absence of tissue squamous metaplasia may predict a CRS phenotype suitable to a trial of long-term macrolide therapy when surgery and topical therapy has failed.

Median Nerve Injury After Removal of Subdermal Implantable Contraceptive

Background: Subdermal implantable contraceptives are highly effective, approved in over 60 countries, and used by millions of women. Due to simple insertion and removal protocols, these procedures are often performed in the outpatient clinic setting, and procedural complications are rare. However, given the location of the implant in the medial antebrachial interval, there is a risk of neurovascular injury, especially with malpositioned or deeply placed implants. Methods: We present a case of proximal median nerve injury leading to severe neuropathy after attempted removal of a subdermal implantable contraceptive requiring neurolysis and tendon transfers. Results: At 6 months post surgery, the patient regained flexion of the index interphalangeal joints and protective sensation in the thumb and index fingers. Conclusions: Subdermal implant retrieval can lead to nerve injury, despite the relative simplicity of the procedure. If difficulty is encountered, imaging or open retrieval should be considered. Improvement in function can be gained through operative interventions including neurolysis and tendon transfers in the setting of severe neuropathy.

Airflow and symptom outcomes between allergic and non-allergic rhinitis patients from turbinoplasty

BACKGROUND

Inferior turbinate procedures are applied to relieve medically refractory nasal obstruction. However, the nature of congestion differs between allergic(AR) and non-allergic rhinitis(NAR). This study compares surgical outcomes between AR and NAR patients.

METHODOLOGY

A case-control study of patients undergoing turbinate with or without septoplasty surgery for nasal obstruction was performed. Patient reported outcomes were: nasal obstruction, global nasal function(GNF), and sino-nasal outcome test(SNOT-22) with rhinitis, facial symptom, sleep and psychological sub-scores. Nasal peak inspiratory flow(NPIF) assessed nasal airflow. Measurements were obtained preoperatively and 3 months postoperatively.

RESULTS

190 patients were assessed. AR had worse obstruction and worse GNF. All outcomes improved post-surgery; nasal obstruction, GNF, SNOT-22, rhinitis-symptoms, facial-symptoms, sleep-function, psychological-function and NPIF. GNF improvement was greater in AR. NPIF improvement was similar between groups.

CONCLUSIONS

Both AR and NAR patients gained benefit from surgery to relieve nasal obstruction. AR patients demonstrate greater improvement in GNF score but allergy management may contribute to this.

Periostin as a marker of mucosal remodelling in chronic rhinosinusitis

BACKGROUND

Although extracellular matrix (ECM) proteins are associated with irreversible lower airway changes, the relationship with upper airway remodelling which occurs during chronic rhinosinusitis (CRS) is poorly understood. This study assessed the expression of ECM proteins periostin, fibulin-1, fibronectin and collagenIV in nasal mucosa of patients with and without histologic features of remodelling.

METHODS

A cross-sectional study of sinonasal mucosal biopsies taken from patients, undergoing surgery for CRS was performed, where patients were grouped according to remodelling, defined by basement membrane thickening (BMT over 7.5 micrometer) and subepithelial fibrosis. An overall view and three random fields of immunostained tissue sections that included epithelium, basement membrane and submucosa, were imaged using Zeiss Zen software. The area and intensity of positive staining were scored by two blinded observers, using a 12-point ordinal scale of weak to strong.

RESULTS

65 patients (47.6 +/- 13.4years, 44.6% female) were assessed. Patients were grouped as controls 26.2%, BMT/no fibrosis 38.5% or BMT and fibrosis 33.8%. Stronger grade of periostin expression was associated with remodelling changes and tissue eosinophilia over 10/HPF. Fibulin-1, fibronectin and collagenIV did not differ.

CONCLUSION

Periostin expression was associated with the presence of BMT, fibrosis and tissue eosinophilia and may identify patients undergoing remodelling changes.

Periostin as a marker of mucosal remodelling in chronic rhinosinusitis

BACKGROUND

Although extracellular matrix (ECM) proteins are associated with irreversible lower airway changes, the relationship with upper airway remodelling which occurs during chronic rhinosinusitis (CRS) is poorly understood. This study assessed the expression of ECM proteins periostin, fibulin-1, fibronectin and collagenIV in nasal mucosa of patients with and without histologic features of remodelling.

METHODS

A cross-sectional study of sinonasal mucosal biopsies taken from patients, undergoing surgery for CRS was performed, where patients were grouped according to remodelling, defined by basement membrane thickening (BMT over 7.5 micrometer) and subepithelial fibrosis. An overall view and three random fields of immunostained tissue sections that included epithelium, basement membrane and submucosa, were imaged using Zeiss Zen software. The area and intensity of positive staining were scored by two blinded observers, using a 12-point ordinal scale of weak to strong.

RESULTS

65 patients (47.6 +/- 13.4years, 44.6% female) were assessed. Patients were grouped as controls 26.2%, BMT/no fibrosis 38.5% or BMT and fibrosis 33.8%. Stronger grade of periostin expression was associated with remodelling changes and tissue eosinophilia over 10/HPF. Fibulin-1, fibronectin and collagenIV did not differ.

CONCLUSION

Periostin expression was associated with the presence of BMT, fibrosis and tissue eosinophilia and may identify patients undergoing remodelling changes.

The impact of bitter taste receptor genetics on culturable bacteria in chronic rhinosinusitis

BACKGROUND

Extra-oral bitter taste receptors have been associated with innate bacterial defence mechanisms. Genetic variation in T2R38 functionality has been shown to be associated with susceptibility to upper respiratory tract infections and chronic rhinosinusitis (CRS). We sought to independently assess the influence of bitter taste receptor genotype on the presence of culturable bacteria in the sinuses.

METHODOLOGY

A cross-sectional analysis of patients with CRS undergoing surgery was performed. Middle meatal nasal swabs were sent for microbiological evaluation at the time of the procedure. Mucosal biopsies were taken and sent for bitter taste receptor genotype analysis. Sequencing of 3 polymorphisms in the TAS2R38 gene was performed to identify genotypes as super-tasters (PAV/PAV), non-tasters (AVI/AVI) or heterozygous expression (PAV/AVI). The presence of culturable organisms and common pathogens were compared with bitter taste receptor genotypes.

RESULTS

25 patients (age 52.4 +/- 18.28 years, 51% female) were assessed. Super-tasters comprised 16% of the group, 24% were non-tasters and 48% had heterozygous expression. A cultured pathogen was grown in 48% of patients; 32% gram-positive, 20% gram-negative, 28% grew Staphylococcus aureus and 12% Pseudomonas aeruginosa. A non-taster genotype was predictive of colonised pathogens. Tissue eosinophilia (more than 10 HPF) was seen in 48%.

CONCLUSION

Even in a small sample of patients with CRS, non-taster T2R38 genotype appears to predict the presence of culturable bacteria colonising the sinus cavity at the time of surgery for their condition. A genetic link to patients more likely to become infected is likely.

Association of gastro-oesophageal reflux and chronic rhinosinusitis: systematic review and meta-analysis

INTRODUCTION

Gastro-oesophageal reflux disease (GORD) has been implicated in the development of chronic rhinosinusitis (CRS). The association of GORD with CRS is systematically assessed from the medical literature.

METHODOLOGY

Embase and MEDLINE were searched using a comprehensive strategy limited to English language and Human subjects. Any study with original data on the experimental, diagnostic, treatment or prognostic association of CRS with GORD was included. Studies without a control group, case reports and review articles were excluded.

RESULTS

The search returned 958 records, with an additional 10 found from bibliographic lists; this produced 32 studies. The included studies (n=32) consisted of studies reporting pathogenic factors (n=20), epidemiological association (n=8), prognostic interactions (n=3), and a combination of these outcomes (n=1). Potential pathogenic roles for GORD in CRS were supported; CRS subjects had greater prevalence of intranasal Helicobacter pylori and acid reflux than subjects without CRS. CRS is more prevalent in GORD sufferers than those without GORD. Evidence is conflicting for GORD as a factor in CRS treatment failure.

CONCLUSION

The results support a significant association of GORD with CRS. Physicians should be cognizant of the potential for acid and non-acid reflux as a driving factor in CRS.

Household air pollution from wood burning in two reconstructed houses from the Danish Viking Age

During 13 winter weeks, an experimental archeology project was undertaken in two Danish reconstructed Viking Age houses with indoor open fireplaces. Volunteers inhabited the houses under living conditions similar to those of the Viking Age, including cooking and heating by wood fire. Carbon monoxide (CO) and particulate matter (PM2.5 ) were measured at varying distances to the fireplace. Near the fireplaces CO (mean) was 16 ppm. PM2.5 (mean) was 3.40 mg/m(3) , however, measured in one house only. The CO:PM mass ratio was found to increase from 6.4 to 22 when increasing the distance to the fire. Two persons carried CO sensors. Average personal exposure was 6.9 ppm, and from this, a personal PM2.5 exposure of 0.41 mg/m(3) was estimated. The levels found here were higher than reported from modern studies conducted in dwellings using biomass for cooking and heating. While this may be due to the Viking house design, the volunteer's lack of training in attending a fire maybe also played a role. Even so, when comparing to today's issues arising from the use of open fires, it must be assumed that also during the Viking Age, the exposure to woodsmoke was a contributing factor to health problems.

Soft-tissue reconstruction after total en bloc sacrectomy

OBJECT

Total en bloc sacrectomy is a dramatic procedure that results in extensive sacral defects. The authors present a series of patients who underwent flap reconstruction after total sacrectomy, report clinical outcomes, and provide a treatment algorithm to guide surgical care of this unique patient population.

METHODS

After institutional review board approval, data were collected for all patients who underwent total sacrectomy between 2002 and 2012 at The Johns Hopkins Hospital. Variables included demographic data, medical history, tumor characteristics, surgical details, postoperative complications, and clinical outcomes. All subtotal sacrectomies were excluded.

RESULTS

Between 2002 and 2012, 9 patients underwent total sacrectomy with flap reconstruction. Diagnoses included chordoma (n = 5), osteoblastoma (n = 1), sarcoma (n = 2), and metastatic colon cancer (n = 1). Six patients received gluteus maximus (GM) flaps with a prosthetic rectal sling following a single-stage, posterior sacrectomy. Four required additional paraspinous muscle (PSM) or pedicled latissimus dorsi (LD) fasciocutaneous flaps. Three patients underwent multistage sacrectomy with an anterior-posterior approach, 2 of whom received pedicled vertical rectus abdominis myocutaneous (VRAM) flaps, and 1 of whom received local GM, LD, and PSM flaps. Flap complications included dehiscence (n = 4) and infection (n = 1). During the 1st year of follow-up, 2 of 9 patients (22%) were able to ambulate with an assistive device by the 1st postoperative month, and 6 of 9 (67%) were ambulatory with a walker by the 3rd postoperative month. By postoperative Month 12, 5 of 9 patients (56%)—or 5 of 5 patients not lost to follow-up (100%)—were able to able to ambulate independently.

CONCLUSIONS

The authors' experience suggests that the GM and pedicled VRAM flaps are reliable options for softtissue reconstruction of total sacrectomy defects. For posterior-only operations, GM flaps with or without a prosthetic rectal sling are generally used. For multistage operations including a laparotomy, the authors consider the pedicled VRAM flap to be the gold standard for simultaneous reconstruction of the pelvic diaphragm and obliteration of dead space.

Monocytes loaded with indocyanine green as active homing contrast agents permit optical differentiation of infectious and non-infectious inflammation

Distinguishing cutaneous infection from sterile inflammation is a diagnostic challenge and currently relies upon subjective interpretation of clinical parameters, microbiological data, and nonspecific imaging. Assessing characteristic variations in leukocytic infiltration may provide more specific information. In this study, we demonstrate that homing of systemically administered monocytes tagged using indocyanine green (ICG), an FDA-approved near infrared dye, may be assessed non-invasively using clinically-applicable laser angiography systems to investigate cutaneous inflammatory processes. RAW 264.7 mouse monocytes co-incubated with ICG fluoresce brightly in the near infrared range. In vitro, the loaded cells retained the ability to chemotax toward monocyte chemotactic protein-1. Following intravascular injection of loaded cells into BALB/c mice with induced sterile inflammation (Complete Freund’s Adjuvant inoculation) or infection (Group A Streptococcus inoculation) of the hind limb, non-invasive whole animal imaging revealed local fluorescence at the inoculation site. There was significantly higher fluorescence of the inoculation site in the infection model than in the inflammation model as early as 2 hours after injection (p<0.05). Microscopic examination of bacterial inoculation site tissue revealed points of near infrared fluorescence, suggesting the presence of ICG-loaded cells. Development of a non-invasive technique to rapidly image inflammatory states without radiation may lead to new tools to distinguish infectious conditions from sterile inflammatory conditions at the bedside.

Cutaneous collateral axonal sprouting re-innervates the skin component and restores sensation of denervated Swine osteomyocutaneous alloflaps

Reconstructive transplantation such as extremity and face transplantation is a viable treatment option for select patients with devastating tissue loss. Sensorimotor recovery is a critical determinant of overall success of such transplants. Although motor function recovery has been extensively studied, mechanisms of sensory re-innervation are not well established. Recent clinical reports of face transplants confirm progressive sensory improvement even in cases where optimal repair of sensory nerves was not achieved. Two forms of sensory nerve regeneration are known. In regenerative sprouting, axonal outgrowth occurs from the transected nerve stump while in collateral sprouting, reinnervation of denervated tissue occurs through growth of uninjured axons into the denervated tissue. The latter mechanism may be more important in settings where transected sensory nerves cannot be re-apposed. In this study, denervated osteomyocutaneous alloflaps (hind- limb transplants) from Major Histocompatibility Complex (MHC)-defined MGH miniature swine were performed to specifically evaluate collateral axonal sprouting for cutaneous sensory re-innervation. The skin component of the flap was externalized and serial skin sections extending from native skin to the grafted flap were biopsied. In order to visualize regenerating axonal structures in the dermis and epidermis, 50um frozen sections were immunostained against axonal and Schwann cell markers. In all alloflaps, collateral axonal sprouts from adjacent recipient skin extended into the denervated skin component along the dermal-epidermal junction from the periphery towards the center. On day 100 post-transplant, regenerating sprouts reached 0.5 cm into the flap centripetally. Eight months following transplant, epidermal fibers were visualized 1.5 cm from the margin (rate of regeneration 0.06 mm per day). All animals had pinprick sensation in the periphery of the transplanted skin within 3 months post-transplant. Restoration of sensory input through collateral axonal sprouting can revive interaction with the environment; restore defense mechanisms and aid in cortical re-integration of vascularized composite allografts.

Near-infrared lymphography as a minimally invasive modality for imaging lymphatic reconstitution in a rat orthotopic hind limb transplantation model

Wider application of vascularized composite allotransplantation (VCA) is limited by the need for chronic immunosuppression. Recent data suggest that the lymphatic system plays an important role in mediating rejection. This study used near-infrared (NIR) lymphography to describe lymphatic reconstitution in a rat VCA model. Syngeneic (Lewis-Lewis) and allogeneic (Brown Norway-Lewis) rat orthotopic hind limb transplants were performed without immunosuppression. Animals were imaged pre- and postoperatively using indocyanine green (ICG) lymphography. Images were collected using an NIR imaging system. Co-localization was achieved through use of an acrylic paint/hydrogen peroxide mixture. In all transplants, ICG first crossed graft suture lines on postoperative day (POD) 5. Clinical signs of rejection also appeared on POD 5 in allogeneic transplants, with most exhibiting Grade 3 rejection by POD 6. Injection of an acrylic paint/hydrogen peroxide mixture on POD 5 confirmed the existence of continuous lymphatic vessels crossing the suture line and draining into the inguinal lymph node. NIR lymphography is a minimally invasive imaging modality that can be used to study lymphatic vessels in a rat VCA model. In allogeneic transplants, lymphatic reconstitution correlated with clinical rejection. Lymphatic reconstitution may represent an early target for immunomodulation.

Indocyanine green near-infrared laser angiography predicts timing for the division of a forehead flap

INTRODUCTION

Reconstruction with flaps requiring delayed division remains common, even with increasing use of free tissue transfer. Patient quality of life and function are significantly decreased during the delay period. Delay could be minimized by developing methods to reliably determine when the flap has developed sufficient vascular supply to undergo successful division. We report the use of laser angiography to determine the appropriate time for division of a forehead flap pedicle.

METHODS

The patient who had risk factors for microvascular disease underwent near-infrared laser angiography using indocyanine green on postoperative day 21 to assess vascular perfusion of the flap. Although traditional clinical examination indicated the flap was not adequately perfused, laser angiography revealed perfusion to all areas of the flap, so the pedicle was divided.

RESULTS

Pedicle division was successful, with no epidermolysis or necrosis.

CONCLUSION

Near-infrared laser angiography with indocyanine green can assess perfusion status of the entire flap and inform the decision to divide the flap in an objective manner.

Organophosphorus pesticide degradation product in vitro metabolic stability and time-course uptake and elimination in rats following oral and intravenous dosing

Levels of urinary dialkylphosphates (DAPs) are currently used as a biomarker of human exposure to organophosphorus insecticides (OPs). It is known that OPs degrade on food commodities to DAPs at levels that approach or exceed those of the parent OP. However, little has been reported on the extent of DAP absorption, distribution, metabolism and excretion. The metabolic stability of O,O-dimethylphosphate (DMP) was assessed using pooled human and rat hepatic microsomes. Time-course samples were collected over 2 h and analyzed by LC-MS/MS. It was found that DMP was not metabolized by rat or pooled human hepatic microsomes. Male Sprague-Dawley rats were administered DMP at 20 mg kg(-1) via oral gavage and i.v. injection. Time-course plasma and urine samples were collected and analyzed by LC-MS/MS. DMP oral bioavailability was found to be 107 ± 39% and the amount of orally administered dose recovered in the urine was 30 ± 9.9% by 48 h. The in vitro metabolic stability, high bioavailability and extent of DMP urinary excretion following oral exposure in a rat model suggests that measurement of DMP as a biomarker of OP exposure may lead to overestimation of human exposure.

A combined deficiency of vitamins E and C causes severe central nervous system damage in guinea pigs

A short period of combined deficiency of vitamins E and C causes profound central nervous system (CNS) dysfunction in guinea pigs. For this report, CNS histopathology was studied to define the nature and extent of injury caused by this double deficiency. Weanling guinea pigs were fed a vitamin E-deficient or -replete diet for 14 d. Then vitamin C was withdrawn from the diet of some guinea pigs. Four diet groups were thus formed: replete, vitamin E deficient, vitamin C deficient, and both vitamin E and C deficient. From 5 to 11 d after institution of the doubly deficient diet, 9 of 12 guinea pigs developed paralysis, and 2 more were found dead. The remaining guinea pig in the doubly deficient group and all animals in the other 3 groups survived without clinical impairment until the experiment was terminated at 13-15 d. Brains and spinal cords were serially sectioned and stained for examination. Only the combined deficiency produced damage in the CNS. The damage consisted mainly of nerve cell death, axonal degeneration, vascular injury, and associated glial cell responses. The spinal cord and the ventral pons in the brainstem were most severely affected, often exhibiting asymmetric cystic lesions. Several features of the lesions suggest that the primary damage was to blood vessels. These results indicate that the paralysis and death caused by combined deficiency of vitamins E and C in guinea pigs is caused by severe damage in the brainstem and spinal cord.

Evaluation of a radioimmunoassay and establishment of a reference interval for salivary cortisol in healthy subjects in Denmark

A commercial radioimmunoassay (RA) for salivary cortisol was evaluated using certified reference material in water and spiked to pooled saliva in the range 2.1-89.1 nmol/L. A variance component model for describing the effects of age, body mass index (BMI), diurnal variation, gender, days of sick leave during the past year, and smoking habits was established. Reference intervals for salivary cortisol in 120 healthy individuals performing their routine work were established according to the International Union of Pure and Applied Chemistry (IUPAC) and the International Federation of Clinical Chemistry (IFCC). The method evaluation of the certified reference material in water did not show any bias of the method, i.e. recovery was 97% [CI: 94%; 100.9%]. LOD (detection limit) was 1.59 nmol/L. The ratio between analytical and within-subject variation (CVa/CVi) was 0.14, indicating that the method was adequate for measurement in healthy subjects. Reference intervals were estimated to be from 3.6 to 35.1 nmol/L for samples at the time of awakening (05.27-07.27), 7.6-39.4 nmol/L for peak level in saliva samples collected 20 min after awakening (05.47-07.47), and LOD 10.3 nmol/L for late afternoon samples (17.00-19.00). Reactivity (increase from awakening to 20 min after awakening) was estimated to be 82% [CI: -179; 345%] and recovery (decrease from 20 min after awakening to 18.00) to be 80% [CI: 51; 109%]. Eighteen percent of the subjects showed a decrease in cortisol in saliva from awakening to 20 min after awakening. Salivary cortisol was not affected by age, body mass index, gender, smoking habits or days of sick leave during the past year.

Reference intervals and variation for urinary epinephrine, norepinephrine and cortisol in healthy men and women in Denmark

Reference intervals for urinary epinephrine, norepinephrine and cortisol in 120 healthy individuals performing their routine work were established according to the International Union of Pure and Applied Chemistry (IUPAC) and the International Federation of Clinical Chemistry and Laboratory Medicine (IFCC) for use in the risk assessment of exposure to occupational stress. Reference intervals were established for three different times of the day: in morning samples (05.45-07.15) the limit of detection (LOD) was 2.10 micromol epinephrine/mol creatinine (82 women) and 2.86 micromol epinephrine/mol creatinine (37 men), and the reference interval was 3.6-29.1 micromol norepinephrine/mol creatinine and 2.3-52.8 micromol cortisol/mol creatinine (119 women and men); in afternoon samples (15.30-18.30) the reference interval was 0.64-10.8 micromol epinephrine/mol creatinine (82 women), 1.20-11.2 micromol/epinephrine/mol creatinine (36 men), 11.0-54.1 micromol/ norepinephrine/mol creatinine and LOD was 42.4 micromol cortisol/mol creatinine (117 women and men); in evening samples (21.45-23.45) LOD was 8.66 micromol epinephrine/mol creatinine (81 women) and 7.99 micromol/epinephrine/mol creatinine (36 men), the reference interval was 11.0-54.1 micromol norepinephrine/mol creatinine, and LOD was 42.4 micromol cortisol/mol creatinine (117 women and men). A variance component model for describing the effects of age, body mass index (BMI), diurnal variation, gender, days of sick leave during past year and smoking habits was established. Women showed a higher morning value but excreted lower amounts of epinephrine during the day as compared to men. No gender differences could be demonstrated for the excretion of norepinephrine and cortisol. Excretion of epinephrine and norepinephrine increased with smoking and decreased with increased BMI. No effects were observed in the excretion of cortisol.

Seasonal and biological variation of urinary epinephrine, norepinephrine, and cortisol in healthy women

BACKGROUND

There is a significant circadian and seasonal periodicity in various endocrine functions. The present study describes the within-day and seasonal fluctuation for urinary catecholamines and cortisol and estimates the within- (CV(i)) and between-subject (CV(g)) coefficients of variation for healthy women undertaking their routine work. In addition, index of individuality (I(i)) and power calculations were derived.

METHODS

Eleven healthy females undertaking their routine life-style at work participated in the study. Each subject collected six samples during 24 h 15 days over a year, giving a total number of 990 samples. Using a random effect analysis of variance, we estimated CV(g) and total within-subject variation (CV(ti)), i.e. combined within-subject and analytical variation, from logarithmically transformed data. Analytical variation was subtracted from CV(ti) to give CV(i). CV(i) was estimated from samples collected monthly during 1 year (CV(iy)), weekly during 1 month (CV(im)), and six to eight times/day (CV(id)).

RESULTS

A seasonal variation was demonstrated for excretion of epinephrine, norepinephrine, and cortisol standardized with creatinine. Concentrations of urinary epinephrine were higher during June and July compared to the rest of the year, whereas concentrations of urinary cortisol were higher during December and January compared to the rest of the year. Excretion of norepinephrine was lower during working hours and higher during hours off work for June and July compared to the rest of the year. There was a high within- and between-subject variation, which could not be explained by menstrual cycle, behavioral, emotional, or cognitive stress reactions.

CONCLUSIONS

Despite high biological variation a reasonably low sample size, e.g. 10-50 individuals, is adequate for practical applicability, i.e. studying differences above 150%. The present study recommends to include the sampling time in the statistical evaluation of data and to be aware of the changes in diurnal variations over seasons. When single measurements are to be evaluated, reference intervals are recommended.

Urinary concentrations of trichloroacetic acid in Danish workers exposed to trichloroethylene, 1947-1985

BACKGROUND

Since 1947, the National Labour Inspection Service in Denmark has relied upon urinary measurements of trichloroacetic acid (TCA) in surveys of the occupational exposure to trichloroethylene (TCE).

METHODS

We examined the paper files relating to 2397 TCA measurements to extract information about the year, the company, the work process and the worker. We used multiple regression models to analyze the effects of various factors on the urinary concentration of TCA.

RESULTS

The regression analyses showed that (1) a four-fold decrease in TCA concentrations occurred from 1947 to 1985; (2) the highest concentrations were observed in the iron and metal, chemical, and dry cleaning industries; (3) TCA levels were two times higher among men compared with women in the iron and metal and dry cleaning industries; (4) TCA concentrations were higher among younger compared with older workers; and (5) persons working in an area in which TCE was used, but not working with TCE themselves, also showed urinary TCA levels indicative of exposure.

CONCLUSIONS

Calendar year, type of industry, degree of contact with TCE, sex and age were predictors of TCA concentration in the urine of Danish workers.

Reference interval and subject variation in excretion of urinary metabolites of nicotine from non-smoking healthy subjects in Denmark

BACKGROUND

Passive smoking has been found to be a respiratory health hazard in humans. The present study describes the calculation of a reference interval for urinary nicotine metabolites calculated as cotinine equivalents on the basis of 72 non-smokers exposed to tobacco smoke less than 25% of the day.

METHODS

Twenty subjects (passive smokers) exposed to tobacco smoke more than 25% of the day (subjectively assessed) and 32 smokers were used to validate the estimated reference interval. Urine samples were collected three times during the day approximately at 06.30, 17.00 and 22.45 h.

RESULTS

Within-subject variation was found to be 89.4, 72.6, and 79.2% and between-subject variation was found to be 64.5, 64.2, and 36.1%. No gender difference could be demonstrated. In general all subjects showed increased concentrations in the afternoon and evening samples compared to the morning samples. Parametric reference interval for excretion of nicotine metabolites in urine from non-smokers was established according to International Union of Pure and Applied Chemistry (IUPAC) and International Federation for Clinical Chemistry (IFCC) for use of risk assessment of exposure to tobacco smoke. The reference interval for urinary cotinine was estimated to be 1.1-90.0 micromol/mol creatinine in morning samples from non-smokers. An intercomparison between the radioimmunoassay (RIA) method used for determination of nicotine metabolites and a gas chromatography-mass spectrometry (GC-MS) method for determination of cotinine was carried out on 27 samples from non-smokers and smokers. Results obtained from the RIA method showed 2.84 [confidence interval (CI): 2.50; 3.18] times higher results compared to the GC-MS method. A linear correlation between the two methods was demonstrated (rho=0.96).

CONCLUSION

The RIA method is rapid and adequate for clinical use in the assessment of exposure to tobacco smoke, i.e. ratio between CV(a)/CV(ti) was<0.50.

Cancer incidence among Danish workers exposed to trichloroethylene

Human evidence regarding the carcinogenicity of the animal carcinogen trichloroethylene (TCE) is limited. We evaluated cancer occurrence among 803 Danish workers exposed to TCE, using historical files of individual air and urinary measurements of TCE-exposure. The standardized incidence ratio (SIR) for cancer overall was close to unity for both men and women who were exposed to TCE. Men had significantly elevated SIRs for non-Hodgkin's lymphoma (SIR = 3.5; n = 8) and cancer of the esophagus (SIR = 4.2; n = 6). Among women, the SIR for cervical cancer was significantly increased (SIR = 3.8; n = 4). No clear dose-response relationship appeared for any of these cancers. We found no increased risk for kidney cancer. In summary, we found no overall increase in cancer risk among TCE-exposed workers in Denmark. For those cancer sites where excesses were noted, the small numbers of observed cases and the lack of dose-related effects hinder etiological conclusions.

Pharmacokinetics and pharmacodynamics of antiulcer agents in llama

Plasma concentration time curves following intravenous (i.v.) administration of 1.5 mg/kg of ranitidine, 0.2 mg/kg, 0.4 mg/kg and 0.8 mg/kg of omeprazole, respectively, were analysed in six llamas. Plasma profiles after i.v. administration of both drugs showed plasma concentrations declining in a biexponential manner with a rapid distribution phase. Pharmacokinetics parameters after ranitidine administration to six llamas showed a mean elimination half-life of 1.53 +/- 0.26 h. The mean volume of distribution (Vdss) in llamas was 1.77 +/- 0.31 L/kg, and mean body clearance in llamas was 0.778 +/- 0.109 L/kg/h. Ranitidine produced only a small transitory (<1 h) decline in acid production when administered i.v. at a dose of 1.5 mg/kg. Omeprazole showed dose-dependent nonlinear pharmacokinetics. The mean half-life of 0.2 mg/kg i.v. omeprazole was shorter than that of 0.4 and 0.8 mg/kg i.v. omeprazole, i.e. 0.61, 0.72 and 1.07 h, respectively. The area under the curve (AUC) and mean residence time (MRT) increased with increasing dose, while clearance decreased as dose increased. The decline in acid production following 0.2 mg/kg i.v. omeprazole was highly variable and did not produce a clinically useful suppression of third compartment acid production. In contrast, both 0.4 mg/kg and 0.8 mg/kg omeprazole i.v. administration significantly reduced third compartment acid production. The reduction in acid production following 0.8 mg/kg omeprazole was not significantly greater than the reduction observed following 0.4 mg/kg dosage. Misoprostol (10 microg/kg) was administered i.v. in an absolute alcohol solution. Two animals collapsed following drug administration. While the side-effects could have been produced by either misoprostol or the alcohol vehicle, the clinical changes were more consistent with an adverse drug reaction. Unfortunately, the limitation of UV detection did not provide the sensitivity needed to quantify the amount of misoprostol in llama plasma, and the pharmacokinetics could not be evaluated.

Repeated exposures to cobalt or chromate on the hands of patients with hand eczema and contact allergy to that metal

The present study aimed at evaluating the effects of daily repeated exposures to low cobalt or chromate concentrations on the hands of patients with hand eczema and cobalt or chromate allergy. For 2 weeks, the patients immersed a finger for 10 min daily into the appropriate metal salt solution in water. During the 1st week, this was a 10 or 50 mg/l cobalt concentration or a 10 mg/l chromate concentration, and, during the 2nd week, a 100 or 200 mg/l cobalt concentration or a 100 mg/l chromate concentration. This regimen elicited a flare of hand eczema only in the chromate-exposed chromate-sensitive patients. During the exposure period, accumulation of cobalt or chromate in the nail was demonstrated. Standardization of chemical methods of quantification of skin exposure to allergens, combined with experimental exposure studies in patients with specific contact allergy, will increase the possibility of providing evidence-based medicine in the area of allergic contact dermatitis in the future.

Nickel-induced cytokine production from mononuclear cells in nickel-sensitive individuals and controls. Cytokine profiles in nickel-sensitive individuals with nickel allergy-related hand eczema before and after nickel challenge

Exposure to nickel is a major cause of allergic contact dermatitis which is considered to be an inflammatory response induced by antigen-specific T cells. Here we describe the in vitro analysis of the nickel-specific T-cell-derived cytokine response of peripheral blood mononuclear cells from 35 nickel-allergic and 30 non-nickel-allergic individuals. Peripheral blood mononuclear cells were stimulated with 10(-4) and 10(-5) mol/l NiSO4 for 6 days and then additionally with ionomycin and phorbol myristate acetate for 24 h. Culture supernatants were analysed for interleukin-4 (IL-4), IL-5, interferon-gamma (IFN-gamma) and tumour necrosis factor-alpha (TNF-alpha) by quantitative ELISA. The analysis showed that the synthesis of IL-4 and IL-5 but not of IFN-gamma or TNF-alpha was significantly higher in the nickel-allergic individuals. The finding of preferential synthesis of Th2 cytokines was somewhat of a surprise, since previous studies have suggested a Th1 response in nickel-mediated allergic contact dermatitis. Subsequently, the nickel-allergic individuals were randomized to experimental exposure to nickel or vehicle in a double-blind design. A daily 10-min exposure of one finger to 10 ppm nickel solution for 1 week followed by 100 ppm for an additional week evoked a clinical response of hand eczema in the nickel-exposed group. Blood samples were drawn on days 7 and 14 after the start of this exposure to occupationally relevant concentrations of nickel. No statistically significant differences were observed in the nickel-induced in vitro cytokine response during the exposure period. Our results indicate the possibility that IL-4 and IL-5 are involved in the pathogenesis of nickel-mediated contact dermatitis.

Seasonal and biological variation of blood concentrations of total cholesterol, dehydroepiandrosterone sulfate, hemoglobin A(1c), IgA, prolactin, and free testosterone in healthy women

BACKGROUND

Concentrations of physiological response variables fluctuate over time. The present study describes within-day and seasonal fluctuations for total cholesterol, dehydroepiandrosterone sulfate (DHEA-S), hemoglobin A(1c) (HbA(1c)), IgA, prolactin, and free testosterone in blood, and estimates within- (CV(i)) and between-subject (CV(g)) CVs for healthy women. In addition, the index of individuality, prediction intervals, and power calculations were derived.

METHODS

A total of 21 healthy female subjects participated in the study. Using a random effects analysis of variance, we estimated CV(g) and total within-subject variation (CV(ti)), i.e., the combined within-subject and analytical variation, from logarithmically transformed data. Analytical variation was subtracted from CV(ti) to give CV(i). CV(i) was estimated from samples taken monthly during 1 year (CV(iy)), weekly during 1 month (CV(im)), and six times within 1 day (CV(id)).

RESULTS

A cyclic seasonal variation was demonstrated for total cholesterol, DHEA-S, HbA(1c), prolactin, and free testosterone. Within-day variation was shown for prolactin and free testosterone. The overall mean values for the group and the variability (CV(iy) and CV(g)) were: 5.1 mmol/L, 13% [corrected], and 12% [corrected] for total cholesterol; 6.6 micromol/L, 20% [corrected], and 49% [corrected] for DHEA-S; 30% [corrected], 7.0% [corrected], and 7.5% [corrected] for HbA(1c)/hemoglobin(total); 2.1 g/L, 5.9%, and 13% for IgA; 136 mIU/L, 58% [corrected], and 63% [corrected] for prolactin; and 5.4 pmol/L, 55% [corrected], and 68% [corrected] for free testosterone.

CONCLUSIONS

Collecting samples at specific hours of the day or times of the year may reduce high biological variation. Alternatively, the number of individuals may be increased and a paired study design chosen to obtain adequate statistical power.

Effects of repeated skin exposure to low nickel concentrations: a model for allergic contact dermatitis to nickel on the hands

We studied the effects of repeated daily exposure to low nickel concentrations on the hands of patients with hand eczema and nickel allergy. The concentrations used were chosen to represent the range of trace to moderate occupational nickel exposure. The study was double-blinded and placebo controlled. Patients immersed a finger for 10 min daily into a 10-p.p.m. nickel concentration in water for the first week, and during the second week into a 100-p.p.m. nickel concentration. This regimen significantly increased (P = 0.05) local vesicle formation and blood flow (P = 0.03) as compared with a group of patients who immersed a finger into water. The nickel concentrations used also provoked significant inflammatory skin changes on sodium lauryl sulphate (SLS)-treated forearm skin of the patients, whereas inflammatory skin changes were not observed in healthy volunteers without hand eczema and nickel allergy, either on normal or on SLS-treated forearm skin. The present study strongly suggests that the changes observed were specific to nickel exposure. Standardized methods to assess trace to moderate nickel exposure on the hands, and the associated effects in nickel-sensitized subjects, are needed.

Nickel concentrations in serum and urine of patients with nickel eczema

This study is a part of the Biological Risk Assessment of Human Metal Sensitisation (BRAHMS) project with the aim of elucidating clinical and physiological effects of repeated exposures to low concentrations of metal allergens. Nickel allergic individuals (n = 35) with hand eczema and healthy controls (n = 30) were included in the study. Both groups had similar levels of nickel in urine, while the level of nickel in serum was significantly lower in nickel allergic individuals compared to controls. Nickel allergic individuals had a significantly lower intake of nickel-rich food items (chocolate, nuts, beans, porridge oats). Serum nickel levels correlated with intake of these foods, suggesting that the difference in serum nickel levels was caused by differences in dietary nickel intake.

Evaluation of a whole cell, p57- vaccine against Renibacterium salmoninarum

A whole cell Renibacterium salmoninarum vaccine was developed using 37 degrees C heat treated cells that were subsequently formalin fixed; this treatment reduced bacterial hydrophobicity and cell associated p57. Coho salmon Oncorhynchus kisutch were immunized with the p57- vaccine by either a combination of intraperitoneal (i.p.) and intramuscular (i.m.) injections or per os. In the first experiment, i.p./i.m. vaccination of coho salmon with p57- cells in Freund's Incomplete Adjuvant (FIA) conferred a statistically significant increase in mean time to death after the salmon were i.p. challenged with 4.1 x 10(6) colony forming units (cfu) of R. salmoninarum. There was no significant difference in response between fish immunized with R. salmoninarum cell surface extract in FIA and those immunized with extracellular protein (ECP) concentrated from culture supernatant in FIA. The i.p. challenge dose resulted in complete mortality of all fish by Day 43. In a second experiment, fish were orally vaccinated with p57- R. salmoninarum cells encased in a pH protected, enteric-coated antigen microsphere (ECAM). Fish were bath challenged with 4.2 x 10(6) cfu ml-1 on Day 0 and sampled at time points of 0 (pre-challenge), 50, 90, or 150 d immersion challenge. Vaccine efficacy was determined by monitoring the elaboration of p57 in the kidneys of vaccinated and control fish. Fish vaccinated orally demonstrated a significantly lower concentration of p57 (p < 0.01) at Day 150 post challenge compared to fish receiving ECAMs alone. Fish receiving p57 cells without ECAM coating also showed a significantly lower p57 level (p < 0.03) versus control. In contrast, fish injected intraperitoneally with the p57- cells or fish fed p57+ R. salmoninarum cells in ECAMs demonstrated no significant difference (p > 0.05) versus controls. In summary, these studies suggest the preliminary efficacy of 37 degrees C treatment of R. salmoninarum cells as an oral bacterial kidney disease vaccine.

Speciation measurements by HPLC-HGAAS of dimethylarsinic acid and arsenobetaine in three candidate lyophilized urine reference materials

Speciation measurements of dimethylarsinic acid (DMA) and arsenobetaine (AsB) in three candidate lyophilized urine reference materials are described. The measurements were based on cation-exchange liquid chromatography coupled to hydride generation atomic absorption spectrometry with on-line digestion of the organic. As species by alkaline persulfate solution aided by ultraviolet radiation. Arsenic concentrations as DMA were significantly different in the three samples. The mean values for the three samples were 4.1 +/- 0.3, 55.3 +/- 1.2 and 134.1 +/- 1.5 micrograms l-1, respectively. No significant differences in AsB concentrations were observed among the three samples. The mean As concentrations as AsB in the three samples were 17.4 +/- 0.4, 17.7 +/- 0.2 and 17.5 +/- 0.3 micrograms l-1, respectively. By off-line digestion of the urine samples, total As concentrations in the three materials were also obtained. The mean values were 23.4 +/- 0.3, 76.6 +/- 1.6 and 151.3 +/- 1.8 micrograms l-1, respectively. These results correlated well with the results obtained by neutron activation analysis in our laboratory (r = 0.999; p < 0.0001).