The influence of operating room temperature and humidity on surgical site infection: A multisite ACS-NSQIP analysis

BACKGROUND

Literature evaluating intraoperative temperature/humidity and risk of surgical site infection (SSI) is lacking.

METHODS

All operations at three centers reported to the ACS-NSQIP were reviewed (2016-2020); ambient intraoperative temperature (⁰F) and relative humidity (RH) were recorded in 15-min intervals. The primary endpoint was superficial SSI, which was evaluated with multi-level logistic regression.

RESULTS

14,519 operations were analyzed with 179 SSIs (1.2%). The lower/upper 10th percentiles for temperature and RH were 64.4/71.4 °F and 33.5/55.5% respectively. Low or high temperature carried no significant increased risk for SSI (Low ⁰F OR = 0.95, 95% CI 0.51-1.77, P = 0.86; High ⁰F OR = 1.13, 95% CI = 0.69-1.86, P = 0.63). This was also true for low and high RH (Low RH OR = 0.96, 95% CI 0.58-1.61, p = 0.88; High RH OR = 0.61, 95% CI = 0.33-1.14, P = 0.12). Analysis of combined temperature/humidity showed no increased risk for SSI.

CONCLUSION

Significant deviations in intraoperative temperature/humidity are not associated with increased risk of SSI.

A 20-Year Analysis of Medicare Reimbursement for Abdominal Wall Reconstruction (2000 to 2020)

BACKGROUND

The purpose of this study was to evaluate monetary trends in Medicare reimbursement rates for 30 abdominal wall reconstruction surgical procedures over a 20-year period (2000 to 2020).

METHODS

The Physician Fee Schedule Look-Up Tool from the Centers for Medicare and Medicaid Services was used for each of the 30 included current CPT codes, and reimbursement data were extracted. Monetary data were adjusted for inflation to 2020 U.S. dollars using changes to the United States consumer price index. The R 2 values for the average annual percentage change and the average total percentage change in reimbursement were calculated based on these adjusted trends for all included procedures.

RESULTS

After adjusting for inflation, the average reimbursement for all procedures decreased by 17.1% from 2000 to 2020. The greatest mean decrease was observed for CPT code 49568 (the implantation of mesh or other prosthesis for open incisional or ventral hernia repair or mesh for closure of débridement for necrotizing soft-tissue infection, -34.4%). The only procedure with an increased adjusted reimbursement rate throughout the study period was CPT code 20680 (+3.9%). From 2000 to 2020, the adjusted reimbursement rate for all included procedures decreased by an average of 0.85% each year, with an average R 2 value of 0.78, indicating a stable decline throughout the study period.

CONCLUSIONS

Reimbursement rates are declining when adjusted for inflation. Increased awareness of these trends is helpful to maintain access to optimal abdominal reconstruction care in the United States.

Patient Perspectives and Quality of Life after Breast Reconstruction and the Impact of Subsequent Revisions

There is limited research on the impact of revisional surgery after breast reconstruction on patient experience and postoperative quality of life (QoL).

Methods

Patients undergoing mastectomy with immediate implant-based or autologous free-flap breast reconstruction from 2008 to 2020 were reviewed. These patients were categorized by revisions (0-1, 2-3, and 4+) and surveyed on QoL metrics using BREAST-Q and Was It Worth It? (WIWI) questionnaires. BREAST-Q QoL, satisfaction, and WIWI metrics between revision groups were evaluated.

Results

Among 252 patients, a total of 150 patients (60%) underwent zero to one revisions, 72 patients (28%) underwent two to three revisions, and 30 patients (12%) underwent four or more revisions. Median follow-up was 6 years (range, 1-11 years). BREAST-Q satisfaction among patients with four or more revisions was significantly lower (P = 0.03), while core QoL domains (chest physical, psychosocial, and sexual well-being) did not significantly differ. Analysis of unplanned reoperations due to complications and breast satisfaction showed no significant difference in QoL scores between groups (P = 0.08). Regarding WIWI QoL metrics, four or more revisions were associated with a higher rate of worse QoL (P = 0.035) and worse overall experience (P = 0.001). Most patients in all revision groups felt it was worthwhile to undergo breast reconstruction (86%), would choose breast reconstruction again (83%), and would recommend breast reconstruction to others (79%).

Conclusions

Overall, a majority of patients undergoing revisions after breast reconstruction still have a worthwhile experience. Although reoperations after breast reconstruction do not significantly impact long-term BREAST-Q QoL domains, patients undergoing four or more revisions have significantly lower breast satisfaction, worse QoL, and a postoperative experience worse than expected.

Postoperative Complication Impact on Quality of Life after Post-Mastectomy Breast Reconstruction

BACKGROUND

Though the overall psychosocial benefits and body image gains of post-mastectomy breast reconstruction (PMBR) are well-established, there is limited information on how postoperative complications affect patient quality of life (QOL).

STUDY DESIGNE

A single-institution cross-sectional survey analysis was performed on patients who underwent PMBR between 2008-2020. QOL was assessed using the BREAST-Q and the Was It Worth It questionnaires. The results were compared between patients who had major complications, minor complications, and no complications. Responses were compared using one-way analysis of variance (ANOVA) and chi-square tests as appropriate.

RESULTS

Five-hundred and sixty-eight patients met inclusion criteria, and 244 patients responded (43% response rate). Most patients did not have any complications (n=128; 52%), 41 had minor complications (17%), and 75 had major complications (31%). There were no differences in any of the BREAST-Q wellbeing metrics based on degree of complication. Across all three groups, patients reported that surgery was worthwhile (n=212; 88%), they would choose reconstruction again (n=203; 85%), and they would recommend it to a friend (n=196; 82%). Overall, 77% reported that their overall experience either met or exceeded expectations, and 88% of patients had unchanged or improved overall QOL.

CONCLUSION

Our study demonstrates that QOL and wellbeing are not negatively impacted by postoperative complications. Though patients who had no complications had an overall more positive experience, nearly two-thirds of all patients, no matter the degree of complication, stated that their overall experience either met or exceeded their expectations.

Operating in an Opioid Crisis: A Temporal Analysis of Pain Medication Prescribing Practices in Plastic Surgery

BACKGROUND

In response to the opioid epidemic, the United States declared a public health emergency in 2017. We evaluated pain medication prescribing practices among plastic and reconstructive surgeons, assessing pain medication prescription rates and opioid-related mortality both nationally and regionally within the United States.

METHODS

A retrospective analysis of Medicare Part D prescriber data among plastic surgeons from 2013 through 2017 was conducted. Pain medications were categorized as opioid and nonopioid medications. Trends in surgeon prescribing habits were evaluated using the Cochrane-Armitage trend test.

RESULTS

A total of 708,817 pain medication claims were identified: 612,123 claims (86%) were for opioid pain medications and 96,694 claims (14%) were for nonopioid pain medications. Total pain medication claims decreased from 44% of all medications in 2013 to 37% in 2017 (P < 0.001). Opioid medications decreased from 37% of total medication claims to 32% (P < 0.001). The overall opioid prescription rate fell from 1.53 claims per beneficiary in 2013 to 1.32 in 2017 (P < 0.001). Nonopioid pain medications decreased from 7% in 2013 to 6% in 2017 (P < 0.001); nonsteroidal anti-inflammatory drug claims increased by 44%. The prescription rate of nonopioid medications decreased from 2.40 claims per beneficiary in 2013 to 2.32 in 2017 (P < 0.001). An overall increase in opioid-related mortality was observed. Trends in pain medication prescriptions varied significantly among US regions and divisions.

CONCLUSIONS

Plastic surgeons are prescribing less opioids and relying more on nonopioid pain medications. Increased adoption of multimodal pain treatment approaches among surgeons is a likely explanation for this trend in face of the current opioid crisis.

The Impact of Same-Day Discharge and Enhanced Recovery on Patient Quality of Life After Mastectomy with Implant Reconstruction

BACKGROUND

This study aimed to evaluate how enhanced recovery (ER) protocols and same-day discharge (SDD) influences patients' postoperative quality of life (QOL).

METHODS

Patients who underwent mastectomy with implant-based breast reconstruction from 2008 to 2020 were identified in a prospective database. The study assessed QOL with BREAST-Q and Was It Worth It? (WIWI) questionnaires. Responses were compared between the ER and pre-ER groups and between the SDD and hospital stay (HS) groups using one-way analysis of variance (ANOVA) and chi-square tests.

RESULTS

The inclusion criteria were met by 568 patients, with a 43% response rate, and 217 patients were included for analysis. Chest physical well-being was lower for the ER cohort, but postoperative breast satisfaction was higher. Psychosocial status, sexual well-being, and satisfaction with information given did not differ significantly between the ER group and the pre-ER or SDD group. In the compared groups, QOL did not differ significantly.

CONCLUSIONS

Enhanced recovery with SDD after mastectomy using implant-based reconstruction did not have an adverse impact on patient postoperative QOL.

Can Montgomery tubercles impact aesthetic 3D nipple-areolar complex tattooing? An anatomical, quantitative analysis of breast cancer patients

PURPOSE

We aimed to establish a relationship between the amount of Montgomery tubercles (MTs) per nipple-areolar complex (NAC) given patient characteristics such as age, BMI, menopausal status, race/ethnicity, and NAC size to better inform current 3D NAC tattooing practices.

METHODS

Preoperative photographs of patients pursuing breast reconstruction after mastectomy in 2010 through 2018 were reviewed. The number of MTs on each native NAC was quantified. The impact of patient factors on the quantity of MTs was evaluated via Pearson correlation and bivariate analyses.

RESULTS

Two hundred and eleven patients (399 breasts) were reviewed. On average, patients had 5.0 ± 5.2 MTs (range, 0-25 MTs). Number of MTs did not correlate with patient age, BMI, or NAC size. Premenopausal females were more likely than postmenopausal females to have a greater number of MTs per breast (p-value = 0.0183).

CONCLUSIONS

Postmastectomy patients desiring a more "youthful" NAC may consider additional MTs when pursuing 3D NAC tattooing.

The impact of mastectomy and reconstruction technique on patient perceived quality of Life

BACKGROUND

We sought to evaluate the impact of mastectomy type, post-mastectomy reconstruction choice, and procedure bilaterality, on patient perceived postoperative quality of life (QoL).

METHODS

Patients who underwent post-mastectomy reconstruction between 2008 and 2020 were identified in a prospective database. QoL was assessed with the BREAST-Q and the Was It Worth It (WIWI) questionnaires. The results were compared between reconstruction type, reconstruction laterality, and type of mastectomy. Responses were compared using one-way analysis of variance (ANOVA) and chi-square tests.

RESULTS

568 patients met inclusion criteria, and 244 patients responded (43%). QoL did not significantly vary between different reconstructions selected, procedure laterality, or mastectomy type. Patients who underwent DIEP flap were significantly more satisfied with their reconstructed breasts than implant-based reconstruction. Overall, over 85% of patients experienced improved or unchanged QoL no matter what reconstruction choices were made.

CONCLUSION

Most domains of QOL are not impacted by mastectomy type, post-mastectomy reconstruction, or laterality.

Characterization of National Medical Societies' Accessible Resources to Support Underrepresented Minority and Female Trainees

IMPORTANCE

The lack of racial, ethnic, and gender diversity in medicine has been recognized as problematic, but the question of what medical educators and societies are doing to rectify and promote representation of historically marginalized groups persists.

OBJECTIVE

To examine what easily accessible resources are offered by medical and surgical societies to support women and individuals in minority groups that are underrepresented in medicine (URiM).

DESIGN, SETTING, AND PARTICIPANTS

This cross-sectional study evaluated transparent and accessible resources on the webpages of societies recognized by the Council of Medical Specialty Societies. Data collection and analysis were performed from September 1, 2021, to November 1, 2021.

MAIN OUTCOMES AND MEASURES

The society websites were searched for official diversity statements, diversity and women task forces or committees, and mentorship and scholarship opportunities for URiM and female trainees. The primary outcome was accessible resources in the form of financial support (scholarships) and mentorship for URiM and female trainees.

RESULTS

Of the 45 societies included in the analysis, 38 (84.4%) have published diversity statements. All but 6 societies (86.7%) have a dedicated diversity task force, committee, or work group. Twenty societies (44.4%) have a committee specifically for women or include women in diversity task force initiatives. Seventeen societies (37.8%) offer minority-specific mentorship, 15 (33.3%) offer scholarships targeted toward URiM trainees, 10 (22.2%) provide gender-specific mentorship, and 8 (17.8%) offer scholarship opportunities for female trainees.

CONCLUSIONS AND RELEVANCE

Although most of the societies included in this study acknowledge the importance of diversity in medicine, less than half of these societies offer readily accessible scholarships or mentorship opportunities to URiM and female applicants.

Current trends in U.S. general surgery practice consolidation

BACKGROUND

Consolidation of physician practices is well-documented in recent years, yet minimal data exist regarding consolidation in general surgery. This study evaluates current trends in general surgery practice consolidation.

METHODS

Data were obtained through the CMS Physician Compare database. Surgeons and practices were categorized by size, and trends were analyzed using the Cochran-Armitage test. Data were stratified by US region.

RESULTS

From 2012 to 2020, practicing general surgeons increased from 20,044 to 20,637 (+3%). Unique general surgery practices declined from 8178 to 6489 (-21%). The percentage of surgeons in practices of 1 or 2 declined from 19% to 12%, while surgeons in groups of 500 or more grew from 20% to 31%. Tests for trends towards consolidation at both the individual surgeon and unique practice levels were significant (p < .001). The Midwest region demonstrated the highest degree of consolidation.

CONCLUSION

Consistent with trends in medicine overall, general surgery is experiencing substantial practice consolidation.

Aesthetic Surgery Research Funding: Where Does It Come From and to Whom Does It Go?

BACKGROUND

Recent data show that aesthetic surgery research is lagging compared with reconstructive surgery: research funding and institutional disparities within aesthetic surgery are potential factors in this trend.

OBJECTIVES

The authors sought to determine if disparities exist in aesthetic surgery research based on funding sources or practice settings.

METHODS

The authors reviewed Aesthetic Surgery Journal articles from 2009 to 2019. Chi-square, t test, bivariate, and multivariate regression analyses were employed to evaluate research trends.

RESULTS

A total of 2262 publications were identified, with 318 funded articles meeting inclusion criteria. The majority of studies (294, 92%) received external funding, with 281 (88%) being supported solely by external funds. Externally funded studies were financed by private industry (194, 66%), foundations/societies (53, 18%), government grants (23, 8%), or a combination of agencies (24, 8%). The majority of funded studies were at academic institutions (266, 84%), followed by private practice (46, 14%) and private industry (6, 2%). Analysis of annual publications revealed a rising percentage of academic-based research, which correlated with decreasing research from private practice (r = -0.95, r2 = 0.89, P < 0.001). Compared with academic institutions, private practice relied more heavily on industry funding (55% vs 87%, respectively, P = 0.001), exhibiting lower rates of foundational/societal (20% vs 2%), governmental (9% vs 0%), combined (8% vs 7%), and internal department funding (8% vs 4%). Article citations and level of evidence were unaffected by funding source, agency, or practice setting.

CONCLUSIONS

Lack of diversity in research funding among private practice surgeons may explain the reported discrepancies that currently exist between aesthetic and reconstructive surgery research.

Formative Feedback with In-Class Question Bank Utilization Improves Resident Satisfaction with General Surgery Didactics

BACKGROUND

Formative feedback provides low-stakes opportunities for educational improvement. To enrich our basic science didactics, formative feedback measures were incorporated into our didactics using mobile devices.

MATERIALS AND METHODS

Lecture changes included institutional paid access to a commercial question bank, a 5-item in-class pre-didactic quiz curated from the question bank and taken on the resident's mobile device, and group discussion of quiz topics. An anonymous survey was sent to participating residents.

RESULTS

Overall response rate was 71% among residents. All reported that the new lecture format was a valuable addition to the basic science curriculum (100% Agree/Strongly Agree), and formative assessments provided valuable feedback about the progress of their learning (Strongly Agree = 42%, Agree =58%). All residents reported that in-class use of their mobile device for quizzes was convenient, with majority (84%) preferring it over paper printouts. Residents were more motivated to study before lecture (Strongly Agree = 42%, Agree =42%), with majority also reporting the new format helped identify weaknesses in their knowledgebase (Strongly Agree = 58%, Agree =33%). While majority of residents agreed that quizzes motivated them to study more after lecture, a large portion disagreed (42%). Majority of senior residents reported that the process of composing quizzes prior to lecture enriched their own learning (57%) and helped them find gaps in their knowledge (71%).

CONCLUSION

Incorporating a commercial question bank within didactics gives general surgery residents formative feedback and encourages learning outside the classroom, leading to improved satisfaction with basic science didactics.

Same-day Discharge Is Safe and Effective After Implant-Based Breast Reconstruction

BACKGROUND

Same-day discharge after mastectomy is a recently described treatment approach. Limited data exist investigating whether same-day discharge can be successfully implemented in patients undergoing mastectomy with immediate implant-based breast reconstruction (IBR).

METHODS

Patients having mastectomy with IBR from 2013 to 2019 were reviewed. Enhanced recovery with same-day discharge was implemented in 2017. Patient characteristics, oncologic treatments, surgical techniques, and 90-day postoperative complications and reoperations were analyzed comparing enhanced recovery patients with historical controls.

RESULTS

A total of 363 patients underwent nipple-sparing (214, 59%) or skin-sparing (149, 41%) mastectomy with 1-stage (270, 74%) or tissue expander (93, 26%) IBR. Enhanced recovery was used for 151 patients, with 79 of these patients (52%) discharged same-day. Overall, enhanced recovery patients experienced a significantly lower rate of 90-day complications (21% vs 41%, P < 0.001), including hematoma (3% vs 11%, P = 0.002), mastectomy flap necrosis (7% vs 15%, P = 0.02), seroma (1% vs 9%, P < 0.001), and wound breakdown (3% vs 9%, P = 0.05). Postoperative complication rates did not significantly differ among enhanced recovery patients discharged same day. Postoperative admissions significantly decreased after enhanced recovery implementation (100% to 48%, P < 0.001), and admitted enhanced recovery patients experienced a lower length of stay (1.2 vs 1.8, P < 0.001). Enhanced recovery patients experienced a lower incidence of ≥1 unplanned reoperation (22% vs 33%, P = 0.01); overall average unplanned and total reoperations did not significantly differ between groups.

CONCLUSIONS

In conjunction with enhanced recovery practices, same-day discharge after mastectomy with IBR is a safe and feasible treatment approach.

Characterizing Occult Nodal Disease Within a Clinically Node-Negative, Neoadjuvant Breast Cancer Population

BACKGROUND

Neoadjuvant therapy aims to preoperatively downstage breast cancer patients. We evaluated nodal upstaging in clinically node-negative (cN0) patients receiving neoadjuvant chemotherapy (NAC) and neoadjuvant endocrine therapy (NET).

METHODS

cN0 patients undergoing neoadjuvant therapy from 2009 to 2018 were reviewed. Univariate and multivariate analyses evaluated rates of nodal upstaging.

RESULTS

A total of 228 cN0 patients with a mean age of 55 years underwent neoadjuvant therapy for Stage I-III invasive carcinoma. Subtypes included ER+/HER2- = 93 (40%), HER2+ = 61 (27%), and triple negative (TNBC) = 74 (33%). Among ER+/HER2- patients, 65 (70%) underwent NET. Overall, 49 patients (21%) were upstaged due to occult nodal disease. Factors associated with higher rates of occult nodal disease included advanced stage on initial presentation (P = .008), larger presenting tumor size (P = .009), low/intermediate tumor grade (P = .025), and ER+/HER2- subtype (P < .001); incidence of occult nodal disease by subtype included: ER+/HER2- = 37%, HER2+ = 15%, TNBC = 8%. Patients experiencing a breast pCR had a significantly lower rate of nodal upstaging compared to those with residual tumor (4% vs. 96%, P < .001). On multivariate analysis, ER+/HER- patients exhibited higher risk of occult nodal disease when compared to patients with HER2+ (odds ratio [OR] = 3.4, 95% CI, 1.2-9.8, P = .003) and TNBC (OR = 5.7, 95% CI, 1.7-19.6, P = .003). Comparing NAC vs. NET in ER+/HER2- patients showed no difference in rates of occult nodal disease (39% vs. 35%, P = .13).

CONCLUSIONS

ER+/HER2- subtype carries higher risk for occult nodal disease after neoadjuvant therapy; NAC versus NET in these patients does not affect nodal upstaging.

Does Prior Breast Augmentation Affect Outcomes After Mastectomy With Reconstruction? An Analysis of Postoperative Complications and Reoperations

BACKGROUND

The purpose of this study is to evaluate how prior breast augmentation impacts rates of complications and risk for reoperation after mastectomy with concurrent breast reconstruction.

METHODS

Patients undergoing nipple-sparing, skin-sparing, or simple mastectomy with implant-based reconstruction from 2008 to 2018 were identified in a prospective database. Postoperative complications and reoperations were then analyzed comparing patients with prior augmentation to patients without history of previous breast surgery.

RESULTS

A total of 468 patients were identified with a median follow-up of 4 years. Of these, 72 had prior augmentation mammoplasty. These patients underwent nipple-sparing (52, 72%), skin-sparing (15, 21%), or simple (5, 7%) mastectomy with immediate direct-to-implant (46, 61%) or tissue expander (26, 35%) reconstruction. On univariate analysis, this cohort had a lower body mass index (23.3 vs 25.3, P = 0.003), a higher rate of nipple-sparing mastectomy (72% vs 54%, P = 0.01), and a higher prevalence of stage I disease (44% vs 33%, P = 0.04). Differences in age, comorbidities, reconstructive techniques, tumor size, and neoadjuvant/adjuvant therapies were not significant. Overall complication rate between patients with or without prior augmentation did not significantly differ (51% vs 50%, P = 0.83); no significant differences in rates of surgical site infection, hematoma, mastectomy skin flap/wound necrosis, nipple complications, implant loss, or capsular contracture were found. Analysis of reoperations between patients with and without prior augmentation revealed no significant differences in average number of subsequent planned, unplanned, or total reoperations. On multivariate analysis, prior breast augmentation was found to be associated with significantly increased risk for undergoing ≥1 unplanned reoperation (odds ratio, 2.28; 95% confidence interval, 1.28-4.05, P = 0.005).

CONCLUSIONS

Prior augmentation mammoplasty does not significantly affect rates of postoperative complications after mastectomy with concurrent reconstruction. Although prior augmentation does not affect number of subsequent reoperations on average, it does increase the risk of experiencing 1 or more unplanned reoperation after mastectomy with reconstruction.

3D Nipple-Areolar Tattoo: It's Technique, Outcomes, and Utilization

BACKGROUND

Three-dimensional (3D) nipple-areolar tattoo is a novel approach to nipple-areolar complex reconstruction for which little data exist. Our aim was to evaluate 3D nipple-areolar tattoo outcomes and investigate if patient factors, payer status, surgeries, or therapies affect tattoo utilization.

METHODS

Patients pursuing skin-sparing (SSM) or attempted nipple-sparing mastectomy (NSM) with breast reconstruction from 2008 to 2019 were reviewed. Outcomes included frequency of 3D tattoo, post-procedure complications (infections, or other local adverse sequelae), and rates, indications, and timing of revisions. Patient factors, payer status, surgeries, and adjuvant therapies underwent univariate analysis comparing rates of 3D tattoo and revisions.

RESULTS

A total of 191 patients were identified; median follow-up was 4 years. The majority of patients were white (165, 86%), married (146, 76%), and post-menopausal (97, 51%), with private insurance (156, 81%). Surgeries included SSM (172, 90%) or attempted NSM (19, 10%) with implant (154, 81%) or autologous reconstruction (37, 19%). Sixty-two patients (32%) underwent 3D nipple-areolar tattooing. No post-procedure complications occurred. After tattooing, 20 patients (32%) pursued revisions, the majority due to color fading (12, 60%). Average time from tattoo to completion of revisions was 5.6 months. Patients undergoing autologous reconstruction had a higher rate of 3D tattooing (p < 0.001). Adjuvant radiation led to a higher rate of revisions (p = 0.02). Patient factors, payer status, index mastectomy, and chemotherapy did not significantly affect rates of 3D tattooing or revisions.

CONCLUSIONS

3D nipple-areolar tattoo utilization is likely unaffected by age, marriage, menopause, or payer status. Radiotherapy and color fading can lead to more revisions.

LEVEL OF EVIDENCE IV

This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266.

Unplanned implant removal in locally advanced breast cancer

Study conducted to determine frequency and timing of unplanned breast implant removal after mastectomy, reconstruction, and postmastectomy radiation (PMRT). From 2010-2017, 52 patients underwent mastectomy, reconstruction, and PMRT. With median follow-up of 3.1 years, 23 patients (44%) experienced implant removal. Implant removal occurred in 9 (17%) patients before starting PMRT and 14 (27%) patients after starting PMRT. Implant removal rates were similar for hypofractionated PMRT compared with standard fractionation and for proton compared with photon PMRT. Implant removal is common for women undergoing mastectomy and reconstruction followed by PMRT. The risk is clinically significant even before starting radiation.

The Chimeric Gracilis and Profunda Artery Perforator Flap: Characterizing This Novel Flap Configuration with Angiography and a Cadaveric Model

BACKGROUND

 A chimerically configured gracilis and profunda artery perforator (PAP) flap is highly prevalent based on recent computed tomography (CT)-imaging data. The purpose of this study is to further characterize the vascular anatomy of this novel flap configuration and determine the feasibility of flap dissection.

METHODS

 To characterize flap arterial anatomy, lower extremity CT angiograms performed from 2011 to 2018 were retrospectively reviewed. To characterize venous anatomy and determine the feasibility of flap harvest, the lower extremities of cadavers were evaluated.

RESULTS

 A total of 974 lower extremity CT angiograms and 32 cadavers were included for the assessment. Of the 974 CT angiograms, majority (966, 99%) were bilateral studies, yielding a total of 1,940 lower extremities (right-lower-extremity = 970 and left-lower-extremity = 970) for radiographic evaluation. On CT angiography, a chimerically configured gracilis and PAP flap was found in 51% of patients (n = 494/974). By laterality, chimeric anatomy was present in 26% of right lower extremities (n = 254/970) and 25% of left lower extremities (n = 240/970); bilateral chimeric anatomy was found in 12% (n = 112/966) of patients. Average length of the common arterial pedicle feeding both gracilis and PAP flap perforasomes was 31.1 ± 16.5 mm (range = 2.0-95.0 mm) with an average diameter of 2.8 ± 0.7 mm (range = 1.3-8.8 mm).A total of 15 cadavers exhibited chimeric anatomy with intact, conjoined arteries and veins allowing for anatomical tracing from the profunda femoris to the distal branches within the tissues of the medial thigh. Dissection and isolation of the common pedicle and distal vessels was feasible with minimal disruption of adjacent tissues. Chimeric flap venous anatomy was favorable, with vena commitante adjacent to the common pedicle in all specimens.

CONCLUSION

 Dissection of a chimeric medial thigh flap consisting of both gracilis and PAP flap tissues is feasible in a cadaveric model. The vascular anatomy of this potential flap appears suitable for future utilization in a clinical setting.

Pyoderma gangrenosum confined to the irradiated chest wall of the reconstructed breast

Pyoderma gangrenosum (PG) is a diagnosis of exclusion worsened by surgical debridement. This report presents two atypical manifestations of PG in the reconstructed breast, whereby the disease is only confined to the irradiated chest wall tissue bed, sparing the abdominal donor sites and the contralateral reconstructed breast.

Capsular contracture in the modern era: A multidisciplinary look at the incidence and risk factors after mastectomy and implant-based breast reconstruction

BACKGROUND

Capsular contracture causes pain, poor cosmesis, and reoperations. This study analyzes its incidence and risk factors in a more modern treatment era.

METHODS

Patients undergoing mastectomy with implant reconstruction from 2010 to 18 were reviewed. Univariate and multivariate analysis evaluated rates and risk factors for capsular contracture.

RESULTS

Among 451 patients, the majority underwent nipple-sparing mastectomy (262, 58.1%) with one-stage reconstruction (283, 62.7%) utilizing subpectoral implants (353, 77.4%) and acellular dermal matrix (354, 78.5%). Overall capsular contracture incidence was 9.8%; the rate after post-mastectomy radiation therapy (PMRT) was 18.7%, and 7.5% for patients without PMRT. Significant factors included neoadjuvant chemotherapy (P = 0.006), hematoma (P = 0.047), and PMRT (P = 0.001). Multivariate analysis showed that PMRT increased risk of capsular contracture (OR = 3.12, 95% CI 1.55-6.26, P = 0.001), and adjuvant chemotherapy was protective (OR = 0.289, 95% CI 0.114-0.731, P = 0.01).

CONCLUSIONS

Incidence of capsular contracture is lower than previously reported. Advancing therapeutic techniques may reduce the risk of this complication.

Exploring the Effect of Post-mastectomy complications on 5-year survival

BACKGROUND

Ramifications of postoperative complications on long-term survival after mastectomy are uncertain.

METHODS

Overall complications (Clavien-Dindo Grades I-IIIB) and wound complications were analyzed using the Kaplan-Meier method for impact on 5-year overall (OS) and disease-free survival (DFS).

RESULTS

A total of 378 patients underwent mastectomy alone (157, 41%) or mastectomy with reconstruction (221, 59%) for Stage I-III disease with a median follow-up of 5 years. Postoperative complications occurred in 186 patients (49%), requiring non-surgical (I/II = 83, 22%) or surgical (IIIa/IIIb = 103, 27%) management. Wound complications occurred in 140 patients (37%). Reconstruction was associated with a higher rate of complication (P < 0.001). Postoperative complications after mastectomy (with or without reconstruction) did not significantly affect OS or DFS. Wound complications also showed no significant effect on OS or DFS following mastectomy alone, or mastectomy with reconstruction.

CONCLUSIONS

Postoperative complications after mastectomy, with or without reconstruction, bear no significant impact on 5-year survival.

Gauging the efficacy of neoadjuvant endocrine therapy in breast cancer patients with known axillary disease

BACKGROUND AND OBJECTIVES

Neoadjuvant endocrine therapy (NET) for ER+ breast cancer can downstage primary tumors. We evaluated NET efficacy in node-positive patients.

METHODS

Node-positive patients undergoing NET for ER+ breast cancer from 2012 to 2019 were reviewed. Primary endpoints included rates of axillary lymphadenectomy (ALND), pathologic complete response (pCR), and final nodal staging.

RESULTS

Thirty-nine patients were included. Before NET, all were clinically node-positive (cN1 = 36, 94%; cN2 = 2, 5%; cN3 = 1, 3%; Stage II = 23, 59%, Stage III = 16, 41%). After NET, nine (23%) had clinically persistent axillary disease necessitating ALND. The remaining 30 (77%) underwent sentinel lymph node biopsy (SLNB). Of these, 25 (83%) were SLNB+ on frozen section, undergoing immediate ALND. Five patients were negative on frozen section: one had a confirmed axillary pCR, and four had residual nodal disease on permanent pathology. One underwent delayed ALND, and for the remaining three patients, decision was made to forgo ALND. Final overall axillary staging was: N0 (pCR) = 1, 3%, pN1mic = 1, 3%, pN1 = 20, 51%, pN2 = 12, 30%, pN3 = 5, 13%; Stage II = 16, 41%, Stage III = 23, 59%.

CONCLUSIONS

While NET is reported to downstage primary tumors, downstaging of the axilla was unsuccessful in the majority of patients.

A Newly Described, Highly Prevalent Arterial Pedicle Perfuses Both Gracilis and Profunda Artery Perforator Flap Tissues: An Angiographic Study of the Medial Thigh

Background Novel secondary flap options are paramount for patients who are not candidates for common reconstructive methods. The purpose of this study is to identify the prevalence of single arterial pedicle supplying both the gracilis muscle and medial thigh tissue carried in a profunda artery perforator (PAP) flap. Such a pedicle could allow the creation of a chimeric gracilis and PAP flap with a single-arterial anastomosis.

Methods We conducted a retrospective review of 157 lower extremity computed tomography (CT) angiograms to assess the vasculature of the thigh soft tissues. Imaging evaluation was supervised by a board-certified musculoskeletal radiologist.

Results Prevalence of a single-arterial pedicle to a gracilis and PAP flap in each patient was 59% (31% within the right leg and 28% in the left leg). Furthermore, 16% of patients had a common arterial pedicle in both lower extremities.

Conclusion Existence of a single-arterial pedicle to both the gracilis muscle and PAP flap tissues is frequently present in most patients in at least one lower extremity. This chimeric flap configuration could serve as a reconstructive avenue for patients, particularly those who have exhausted other more common flap options. Screening angiography is warranted in patients looking for this anatomic variation to establish its presence.

The bradford method for protein quantitation

A rapid and accurate method for the estimation of protein concentration is essential in many fields of protein study. The Lowry method ( Chapter 1 in vol. 1 of this series) has been widely used, but is susceptible to interference from a wide range of compounds commonly present in biological extracts. Although interference can be avoided by trichloracetic acid precipitation of the protein prior to assay, this lengthens the procedure.

Hepatic encephalopathy and role of antibenzodiazepines

The majority of pharmacological agents are designed to accomplish a specific effect based on the established mechanisms of a disease. However, there are a few examples in which investigation of a pharmacological action has led to a previously unknown mechanism, i. e. the drug effect was observed initially before its mechanism became known. For example, the opiates had been in use for their analgesic effect for centuries before the question of endogenous substances that might explain the presence of opiate binding sites in the central nervous system (CNS) was raised, leading to the discovery of the opioids. A somewhat analogous development has occurred in another investigative arena, the observation that the administration of the benzodiazepine antagonist, flumazenil, has reversed the encephalopathy of hepatic failure. This has refocused research to discover whether one or more endogenous substances that bind to the benzodiazepine receptor in the CNS are responsible for the inhibition of CNS function of advanced liver failure. The investigative impetus was initiated by observations that patients with liver failure were highly vulnerable to benzodiazepines; therapeutic dosages precipitated coma or near-coma, and this effect was prolonged. The question was raised whether any given patient presenting with a coma-like state associated with advanced liver dysfunction might have received a benzodiazepine in the recent past, under circumstances overlooked or not recorded, that might be a contributing factor to the patient's condition. This led to testing the effects of the antagonist, with transitory success in arousing patients or improving their level of stupor. Further inquiry revealed that this improvement in mental function occurred in the absence of prior exposure to benzodiazepines. There followed a search for endogenous substances capable of binding to the benzodiazepine receptor, with CNS inhibitory effects. These investigations have resulted in the identification of several substances that may play a role in encephalopathy and can be displaced from the CNS receptor by properly designed antagonists-an ongoing investigative effort.

Phospholipid antibodies in alcoholic liver disease

Alcoholic liver injury has been reported to be directed preferentially against the proteins of the cell membrane, sparing the phospholipids. However, antiphospholipid antibodies against certain cell membrane phospholipids are known to be associated with a variety of diseases. We undertook this investigation to determine whether antiphospholipid antibodies were present in the serum of patients with alcoholic liver disease. We investigated seventy long-term alcoholic patients (> 80 gm ethanol/day for > 1 yr) and 8 normal nonalcoholic controls by means of enzyme-linked immunosorbent assay to determine whether serum antibodies were generated against the following membrane phospholipids: phosphatidylserine, phosphatidylinositol, phosphatidylethanolamine, phosphatidylglycerol, diphosphatidylglycerol (cardiolipin) and phosphatidic acid. Group 1 comprised alcoholic patients with normal liver function (n = 13), group 2 comprised alcoholic patients with abnormal liver function (n = 16), group 3 comprised patients with alcoholic hepatitis or cirrhosis (n = 41) and group 4 comprised nonalcoholic controls (n = 8). The antibody prevalence was 15% in group 1, 31% in group 2, 81% in group 3 and 0% in group 4. In group 3, 20 of 41 patients had antibodies against several cell membrane phospholipids (i.e., phosphatidylethanolamine, phosphatidylserine, phosphatidylglycerol, phosphatidic acid, cardiolipin and phosphatidylinositol). The antiphosphatidylethanolamine isotype was IgA or IgM in 25 of 41 of these patients. Both IgA (p < 0.01) and IgM (p < 0.008) antiphosphatidylethanolamine correlated significantly with disease severity. Antiphospholipid antibodies in alcoholic patients seem to reflect disease progression and correlate significantly with disease severity.

Effect of low temperature on the activity of phosphofructokinase from potato tubers

The aim of this work was to compare the coldlability of phosphofructokinase (EC 2.7.1.11) from tubers of potato cultivars (cvs.) known to differ in their propensity to accumulate sugars at low temperature. When stored at 4°C for six weeks, the sugar content of tubers ofSolanum tuberosum L. cv. Record doubled whereas the amount of sugar in tubers of cv. Brodick and an advanced breeding clone (13676) decreased slightly. Tubers from each line contained four forms of phophofructokinase. Over the range 12°-16°C the temperature coefficients of the four forms of phosphofructokinase from cvs. Record and Brodick were similar. In cv. Record the temperature coefficients of three of the enzyme forms were significantly higher at 2°-6°C than at 12°-16°C, whereas those from cv. Brodick were unchanged. These results are consistent with the proposal that inactivation of phosphofructokinase at low temperature results in the accumulation of hexose phosphates leading to increased sucrose synthesis.

Clinical zinc deficiency during adequate enteral nutrition

Deficiency of zinc (Zn), resulting in characteristic skin changes resembling those seen in acrodermatitis enteropathica, has been reported in patients on total parenteral nutrition, but rarely in patients on long-term enteral feeding. Reported here is a patient who developed characteristic skin changes while he was receiving what was considered to be a balanced liquid enteral diet. The skin rash resolved with Zn supplementation.

Molecular characterization of four forms of phosphofructokinase purified from potato tuber

Four forms of phosphofructokinase (PFK) have been purified to apparent homogeneity from tubers of potato (Solanum tuberosum cv. Record). Each had a final specific activity of about 200 mumol.min-1.mg-1 protein. Similar forms of PFK were found in partially purified extracts from tubers and leaves of other potato cultivars and related wild species. The relative molecular masses of three forms of PFK were about 200,000 whereas that of the fourth PFK was greater than 800,000. The four forms of PFK contained different proportions of four polypeptides which had apparent relative molecular masses of 46,300, 49,500, 50,000, and 53,000. These polypeptides gave different patterns of peptide fragments after chemical and proteolytic cleavage. Western blots and immunoprecipitation studies using antibodies raised against the individual polypeptides showed that all four are associated with PFK. Thus, potato tubers contain four distinct forms of PFK that differ in their subunit composition.

Molecular Comparison of Pyrophosphate- and ATP-Dependent Fructose 6-Phosphate 1-Phosphotransferases from Potato Tuber

The aim of this work was to compare the molecular properties of pyrophosphate:fructose 6-phosphate 1-phosphotransferase (PFP) and ATP:fructose 6-phosphate 1-phosphotransferase (PFK). Both enzymes were purified to apparent homogeneity from potato tubers (Solanum tuberosum cv Record). Neither PFP nor PFK preparations contained detectable activity of the other enzyme. PFP was composed of two polypeptides of apparent molecular weight 58,000 and 55,700 whereas PFK contained four polypeptides of apparent molecular weight between 46,300 and 53,300. Chemical cleavage of individual PFP and PFK polypeptides gave a different set of fragments for each polypeptide. On Western blots antisera against PFP failed to cross-react with any of the four PFK polypeptides, and antibodies against PFK failed to bind to either of the PFP polypeptides. Antibodies that immunoprecipitate PFP activity had no effect on PFK activity. Conversely, antibodies against the four PFK polypeptides precipitated the activity of PFK, but not that of PFP. This work shows that potato tuber PFP and PFK are composed of distinct, unrelated polypeptides and indicate that interconversion between PFP and PFK is unlikely.

Effects of low temperature on the respiratory metabolism of carbohydrates by plants

The effects of lowering the temperature from 25 degrees C to 2-8 degrees C on carbohydrate metabolism by plant cells are considered. Particular emphasis is placed on the mechanism of cold-induced sweetening in tubers of potato (Solanum tuberosum). Temperatures between 0 and 10 degrees C were shown to cause a marked reduction in the rate of respiration of a wide range of plant tissues. At these temperatures the ability of suspension cultures of soybean (Glycine max), and callus cultures and tubers of potato to metabolize [14C]glucose was appreciably diminished. The detailed distribution of 14C showed that lowering the temperature decreased the proportion of the metabolized [14C]glucose that entered the respiratory pathways and increased the proportion converted to sucrose. Pulse and chase experiments, in which [14C]glucose was supplied to potato tubers at 2 and 25 degrees C, showed that lowering the temperature led to accumulation of label in hexose 6-phosphates, which were subsequently converted to sucrose. The patterns of 14CO2 production from specifically labelled [14C]glucose supplied to soybean suspension cultures and disks of potato tuber suggested that lowering the temperature reduced the activity of glycolysis more than that of the oxidative pentose phosphate pathway. It is argued that the above experiments demonstrate that lowering the temperature not only reduces the rate of carbohydrate metabolism but also alters the relative activities of the different pathways involved. A disproportionate reduction in glycolysis at the lower temperatures is suggested. Mature tubers of many varieties of potato accumulate sucrose and hexose when stored between 2 and 10 degrees C. Starch is the source of carbon for this synthesis of sugar. We could not detect cytosolic fructose-1,6-bisphosphatase in potato tubers and suggest that carbon for sugar synthesis in the cold leaves the amyloplast, not as triose phosphate, but probably as a six-carbon compound. Evidence is presented that phosphofructokinase (EC 2.7.1.11) plays a major role in regulating the entry of hexose 6-phosphates into glycolysis in potato tubers. Phosphofructokinase was purified from potato tubers and shown to consist of four forms. Three of these forms were shown to have higher Q10 values over the range 2-6 degrees C than over the range 12-16 degrees C and are regarded as being cold-labile. No such cold-lability was detected for the key enzymes involved in sucrose synthesis and the oxidative pentose phosphate pathway.(ABSTRACT TRUNCATED AT 250 WORDS)

Purification of immunoglobulins using protein a-sepharose

Most immunochemical techniques used in molecular biology rely on a specific class of antibodies, immunoglobulin G (IgG). In mammals, IgG antibodies are produced during the secondary humoral response and contribute about 80% of the serum immunoglobulin. Factors affecting the experimental production of antibodies have been discussed in detail (1). In this chapter we describe a method for the rapid and efficient purification of IgG to near homogeneity from rabbit serum. This is achieved by affinity chromatography using protein A.

Immunodetection of proteins on "western" blots using (125)i-labeled protein a

Immunoblotting provides a simple and effective method for identifying specific antigens in a complex mixture of proteins. Initially, the constituent polypeptides are separated using SDS-polyacrylamide gel electrophoresis, or a similar technique, and then are transferred either electrophoretically or by diffusion onto a nitrocellulose filter. The transfer of proteins from gels onto membranes is discussed in vol. 1 of this series and Chapters 28 and 29 , this volume. Once immobilized on a sheet of nitrocellulose, specific polypeptides can be identified using antibodies that bind to antigens retained on the filter. In this chapter we describe conditions appropriate for binding antibodies to immobilized proteins and a method for locating these antibody-antigen complexes using (125)I-labeled protein A. These methods are based on those of Burnett (1) and Towbin et al. (2).

Effect of nizatidine and cimetidine on betazole-stimulated gastric secretion of normal subjects: comparison of effects on acid, water, and pepsin

The effect of nizatidine, a new histamine H2 receptor antagonist, on gastric secretory function of eight normal subjects stimulated with betazole, was compared with that of cimetidine. Single oral doses of 75 mg, 150 mg, and 300 mg nizatidine, 300 mg cimetidine, and a placebo were administered on separate occasions 1 h before betazole stimulation. Gastric secretions were recovered in 15-min fractions for the ensuing 2 h, and the pH, H+ concentration and output, volume, and pepsin concentration and output were determined. Doses of 150 mg and 300 mg nizatidine depressed the secretory response significantly more than did cimetidine. The antisecretory effects of 75 mg nizatidine was no different than that of 300 mg cimetidine. Nizatidine 300 mg inhibited pepsin output significantly more than volume. Although pepsin concentration was reduced more than volume, the difference was not significant. These observations, in contrast to results of previous studies, suggest a direct inhibition of pepsin secretion, although to a lesser extent than that of acid.

ATP-Dependent Proteolytic Activity from Spinach Leaves

Spinach (Spinacia oleracea CV Bloomsdale Long Standing) leaf cytoplasmic starch phosphorylase and rabbit muscle phosphorylase a were inactivated by incubation with partially purified leaf extract in the presence of ATP and Mg(2+). The inactivating factor(s) were heat stable and susceptible to protease attack. Phosphorylase inactivation was prevented by incubation in the presence of p-aminobenzamidine and phenylboronic acid, or prolonged treatment with phenylmethylsulfonyl fluoride or leupeptin for the ATP-stimulated inhibitory activity. Mg(2+) -dependent inactivation was prevented by incubation with leupeptin, phenylmethylsulfonyl fluoride, p-aminobenzamidine, or 5'-adenylate. ATP-mediated inactivation of phosphorylase was stimulated by Mg(2+) with a reduction in the apparent K(m) for ATP. Casein-degrading activities with the same properties of ATP and/or Mg(2+) stimulation, heat stability, and susceptibility to proteinase inhibitors were detected suggesting that phorphorylase inactivation was due to proteolysis. The activity was greatest at about the time of flowering and also appeared to depend on the light regime.

Spinach Leaf Intra and Extra Chloroplast Phosphorylase Activities during Growth

The amino terminal sequence of the spinach (Spinacia oleracea L. cv Bloomsdale Long Standing) leaf cytoplasmic phosphorylase was determined and shown to have little similarity to the known sequence of the potato tuber phosphorylase. The antigenic reaction of spinach chloroplast phosphorylase and rabbit muscle phosphorylase a to antiserum prepared against spinach leaf cytoplasmic phosphorylase was tested. Neither phosphorylase gave a positive reaction when tested by immunodiffusion or neutralization of enzyme activity. The two spinach phosphorylases were assayed throughout the growth of the plant. Activity of cytoplasmic phosphorylase increased 4- to 8-fold at 30 to 35 days from sowing. Enzyme protein levels, as measured by antibody neutralization, increased by a similar amount. There was no corresponding increase in chloroplast phosphorylase activity. The chloroplast phosphorylase varied in parallel with the chloroplast enzyme ADPglucose pyrophosphorylase. Starch levels were high during the earlier stages of growth and then fell to a constant low level just before the increase in cytoplasmic phosphorylase. The results are discussed with respect to the relationship and functions of the two phosphorylases.

Leaf Starch Metabolism during the Growth of Pepper (Capsicum annuum) Plants

Levels of starch and sugars, and the activities of amylase and starch phosphorylase were measured in expanding leaves harvested in early morning and early evening during the growth of pepper (Capsicum annuum L.; cv ;Bellboy') plants. The differences between starch levels 1 hour after dawn and 1 hour after dusk increased during the period of initial fruit expansion. This diurnal starch difference was strongly correlated with post-dusk amylase activities in leaves at both stages of expansion. There was also a strong correlation between levels of amylase in immature and those in mature leaves throughout the experiment. Phosphorylase activity showed no direct relationship to leaf starch levels, and there was no similarity between activities in immature and mature leaves. An increase in photosynthesis during plant development was observed which could account for the increased starch synthesis at initial fruit expansion.

Chemical and electron microscopic studies of factors associated with the release of penicillinase from Staphylococcus aureus

The effect of various factors such as sodium chloride, sodium citrate, pH, linase by Staphylococcus aureus ATCC 14458 was investigated. Penicillinase was measured at selected time intervals from supernates of cultures grown in Antibiotic Medium 3 broth containing various concentrations of salts or buffers or from supernates of cultures treated with lysostaphin and subsequently disrupted by French press treatment. Incubation of cells with media containing either sodium chloride (5, 10, and 15%), sodium citrate (5 and 10%), or organic buffers (Tris-HCl, 2.5, 5.0, and 7.5%; BES, 10 and 20%) resulted in a significant stimulation of the release of penicillinase when compared to control cells. It was also observed that pH 7.0-7.5 was optimal for penicillinase activity and release. From studies of enzymatic and mechanical disruption of cells, it was observed that an increase in ionic strength of the suspending medium to certain optimal levels appeared to stimulate the conversion of penicillinase to an extracellular form. Electron microscopic studies revealed that a large number of mesosomal vesicles seemed to be present in cells incubated for 4 hours in media containing various concentrations of sodium chloride. It is proposed that either appearance of vesicles or convolution of cell membrane, which may be caused by further synthesis of new membrane, is involved in stimulation of the synthesis and release of membrane-bound penicillinase.

Ethylene production by axenic fruiting cultures of Agaricus bisporus

Axenic cultures of Agaricus bisporus were used to show that the rise in ethylene production during fruiting derives from its own metabolism.

Pancreatitis following the intraductal injection of partially purified enterokinase in dogs

Experimental pancreatitis (PT) is induced by proximal and distal duodenal closure in the bile-duct-ligated dog, by causing duodeno-pancreatic reflux of lumenal secretions. It has been postulated that trypsin and enterokinase (EK) in the secretions activate trypsinogen within the pancreas, producing PT. There is supporting evidence for trypsin, but EK has not previously been investigated. To determine whether EK alone could cause PT, we injected saline suspensions of partially purified EK, and other test materials, into the duct of Wirsung of dogs and after 24 hr examined their pancreases and estimated the increment in serum amylase. Following 0.5% EK, both PT and hyperamylasemia (HA) ensued; HA without PT occured when EK was inactivated by heat, administered with trypsin inhibitor (TI), or administered in more dilute solution. Injection of TI or of hog gastric mucin likewise leads to HA but not to PT. It is concluded that the PT observed was due to EK activity, and that therefore EK could contribute to the production of PT observed was due to EK activity, and that therefore EK could contribute to the production of PT in the closed-duodenal-loop model. The HA observed in the absence of PT is unexplained but appears to be related to the colloidal properties of the materials injected.

Carbohydrate metabolism in Agaricus bisporus (Lange) Sing: changes in soluble carbohydrates during growth of mycelium and sporophore

Changes in the ethanol-soluble carbohydrate content of Agaricus bisporus mycelium and sporophores grown on semi-defined media and commercial compost were studied. The accumulation of mannitol in the sporophore during its growth was not accompanied by an increase in mycelial mannitol. The other major soluble carbohydrate of the sporophore, trehalose, decreased throughout the growth of the sporophore; a parallel decrease was observed in the mycelium. The main accumulation of mannitol was in the pileus and stipe of the sporophore and was accompanied by a decrease in the soluble protein content of these tissues. Before fruiting, glucose and sucrose were present in the mycelial samples in similar quantities to mannitol, but their levels decreased during fruiting. Small quantities of glucose were present in the sporophore. The results are discussed in relation to the possible functions of the soluble carbohydrates.