Cultural competency and ethical behavior for collaboration in limited-resource settings: Guidelines from the Society of University Surgeons Academic Global Surgery Committee and the Association for Academic Global Surgery

BACKGROUND

There are an increasing number of global surgery activities worldwide. With such tremendous growth, there is a potential risk for untoward interactions between high-income country members and low-middle income country members, leading to programmatic failure, poor results, and/or low impact.

METHODS

Key concepts for cultural competency and ethical behavior were generated by the Academic Global Surgery Committee of the Society for University Surgeons in collaboration with the Association for Academic Global Surgery. Both societies ensured active participation from high-income countries and low-middle income countries.

RESULTS

The guidelines provide a framework for cultural competency and ethical behavior for high-income country members when collaborating with low-middle income country partners by offering recommendations for: (1) preparation for work with low-middle income countries; (2) process standardization; (3) working with the local community; (4) limits of practice; (5) patient autonomy and consent; (6) trainees; (7) potential pitfalls; and (8) gray areas.

CONCLUSION

The article provides an actionable framework to address potential cultural competency and ethical behavior issues in high-income country - low-middle income country global surgery collaborations.

Identifying Hot Spots of Tuberculosis in Nigeria Using an Early Warning Outbreak Recognition System: Retrospective Analysis of Implications for Active Case Finding Interventions

BACKGROUND

Undiagnosed tuberculosis (TB) cases are the major challenge to TB control in Nigeria. An early warning outbreak recognition system (EWORS) is a system that is primarily used to detect infectious disease outbreaks; this system can be used as a case-based geospatial tool for the real-time identification of hot spot areas with clusters of TB patients. TB screening targeted at such hot spots should yield more TB cases than screening targeted at non-hot spots.

OBJECTIVE

We aimed to demonstrate the effectiveness of an EWORS for TB hot spot mapping as a tool for detecting areas with increased TB case yields in high TB-burden states of Nigeria.

METHODS

KNCV Tuberculosis Foundation Nigeria deployed an EWORS to 14 high-burden states in Nigeria. The system used an advanced surveillance mechanism to identify TB patients' residences in clusters, enabling it to predict areas with elevated disease spread (ie, hot spots) at the ward level. TB screening outreach using the World Health Organization 4-symptom screening method was conducted in 121 hot spot wards and 213 non-hot spot wards selected from the same communities. Presumptive cases identified were evaluated for TB using the GeneXpert instrument or chest X-ray. Confirmed TB cases from both areas were linked to treatment. Data from the hot spot and non-hot spot wards were analyzed retrospectively for this study.

RESULTS

During the 16-month intervention, a total of 1,962,042 persons (n=734,384, 37.4% male, n=1,227,658, 62.6% female) and 2,025,286 persons (n=701,103, 34.6% male, n=1,324,183, 65.4% female) participated in the community TB screening outreaches in the hot spot and non-hot spot areas, respectively. Presumptive cases among all patients screened were 268,264 (N=3,987,328, 6.7%) and confirmed TB cases were 22,618 (N=222,270, 10.1%). The number needed to screen to diagnose a TB case in the hot spot and non-hot spot areas was 146 and 193 per 10,000 people, respectively.

CONCLUSIONS

Active TB case finding in EWORS-mapped hot spot areas yielded higher TB cases than the non-hot spot areas in the 14 high-burden states of Nigeria. With the application of EWORS, the precision of diagnosing TB among presumptive cases increased from 0.077 to 0.103, and the number of presumptive cases needed to diagnose a TB case decreased from 14.047 to 10.255 per 10,000 people.

Academic Global Surgery Curricula: Current Status and a Call for a More Equitable Approach

INTRODUCTION

We aimed to search the literature for global surgical curricula, assess if published resources align with existing competency frameworks in global health and surgical education, and determine if there is consensus around a fundamental set of competencies for the developing field of academic global surgery.

METHODS

We reviewed SciVerse SCOPUS, PubMed, African Medicus Index, African Journals Online (AJOL), SciELO, Latin American and Caribbean Health Sciences Literature (LILACS) and Bioline for manuscripts on global surgery curricula and evaluated the results using existing competency frameworks in global health and surgical education from Consortium of the Universities for Global Health (CUGH) and Accreditation Council for Graduate Medical Education (ACGME) professional competencies.

RESULTS

Our search generated 250 publications, of which 18 were eligible: (1) a total of 10 reported existing competency-based curricula that were concurrent with international experiences, (2) two reported existing pre-departure competency-based curricula, (3) six proposed theoretical competency-based curricula for future global surgery education. All, but one, were based in high-income countries (HICs) and focused on the needs of HIC trainees. None met all 17 competencies, none cited the CUGH competency on "Health Equity and Social Justice" and only one mentioned "Social and Environmental Determinants of Health." Only 22% (n = 4) were available as open-access.

CONCLUSION

Currently, there is no universally accepted set of competencies on the fundamentals of academic global surgery. Existing literature are predominantly by and for HIC institutions and trainees. Current frameworks are inadequate for this emerging academic field. The field needs competencies with explicit input from LMIC experts to ensure creation of educational resources that are accessible and relevant to trainees from around the world.

What Predicts Recurrent Kidney Stone after Parathyroidectomy in Patients with Primary Hyperparathyroidism?

BACKGROUND

Some, but not all, patients with primary hyperparathyroidism (PHPT) and kidney stone disease (KSD) are cured of their nephrolithiasis after parathyroidectomy. The goal of this study was to identify risk factors for recurrent KSD despite successful parathyroidectomy in known stone formers with PHPT.

STUDY DESIGN

We conducted a single-center retrospective review of patients presenting to urology clinic with KSD between January 2008 and July 2018, who were diagnosed with concurrent PHPT, and underwent definitive parathyroidectomy. Laboratory testing for serum calcium, PTH (parathyroid hormone), phosphorus and 25-OH-vitamin D, and 24-hour urine studies for volume, pH, calcium, citrate, oxalate, uric acid, sodium, and creatinine was performed pre- and post-parathyroidectomy. Stone recurrence was determined on routine diagnostic imaging or by symptomatic KSD.

RESULTS

Mean age at parathyroidectomy was 57 ± 14 years. Pre-parathyroidectomy, mean serum calcium, 24-hour urine calcium, and PTH were 10.6 ± 0.5 mg/dL, 378 ± 209 mg/day, and 114 ± 97 pg/mL, respectively. Twenty-six of 69 patients (38%) had multigland parathyroid disease. After parathyroidectomy, serum calcium and PTH levels normalized in 69 of 69 and 62 of 69 patients, respectively. However, 37 of 69 patients (54%) had persistent hypercalciuria postoperatively, and 16 of 69 (23%) had recurrent KSD, on average, 2.0 ± 1.6 years after parathyroidectomy. Patients with recurrent KSD post-parathyroidectomy were significantly younger compared with patients without recurrent KSD (51 ± 15 vs 60 ± 13 years, p = 0.02). In a logistic regression model, younger age remains a strong predictive factor for recurrent KSD.

CONCLUSIONS

Nearly one-quarter of PHPT patients with KSD who undergo successful parathyroidectomy present with recurrent KSD despite normalization of serum calcium, and more than half exhibit persistent calciuria. These patients were younger and may require closer monitoring for stone recurrence after successful parathyroidectomy. Further studies are needed to better identify the etiology of KSD post-parathyroidectomy.

Abstract A33: Biomarkers of Cdk5 driven neuroendocrine tumors

Background: Neuroendocrine (NE) cancers originate from secretory cells of the body's various endocrine structures. Surgical resection is the primary treatment for these tumors. However, the majority of NE cancers are metastatic at the time of detection and no effective adjuvant therapies exist for primary NE tumors or their metastases. Patients often develop two or more NE cancers, a syndrome termed multiple endocrine neoplasia (MEN). DNA sequencing has lead to breakthroughs in the identification of genes mutated in four types of familial MEN syndromes: Menin, RET, and CDNK1B. Unfortunately, a large percentage of NE cancers are sporadic, resulting from somatic mutations, and a high percentage of these do not harbor menin, RET, or CDNK1B mutations. Our lab has determined that Cdk5 promotes growth in multiple types of NE cancer. Phosphoproteomic studies revealed a selective set of proteins potentially phosphorylated downstream of Cdk5 activation. We hypothesize that these phosphoproteins will serve as biomarkers to identify tumors that will be responsive to anti-Cdk5 therapies.

Methods: Phosphorylation state-specific antibodies were generated to novel phosphoprotein sites by inoculation of New Zealand White rabbits with phosphopeptides specific to each site. Antibodies were isolated from rabbit sera by affinity purification using phosphopeptide columns. Human NE cell lines were treated with Cdk5 inhibitors and monitored for effects on phosphoprotein levels. Phosphoprotein levels were examined in growing and arrested medullary thyroid carcinoma tumors isolated from an inducible/arrestable (NSE-tTA; tetO-p25GFP) mouse model and in normal lung versus small cell lung cancer tumors isolated from a triple conditional knockout (p130 f/f; p53 f/f; Rb f/f) mouse model. Phosphoprotein levels were examined in control tissue and human medullary thyroid carcinoma, gastrointestinal NETs, and pancreatic NETs.

Results: Phosphorylation state-specific antibodies were successfully generated to 10 novel phosphoproteins. Cdk5 inhibition decreases phosphorylation levels of 5 of these 10 proteins in several types of NE cell lines. Levels of 4 of these phosphoproteins are elevated in human NE tumors.

Conclusion: Four novel phosphoproteins downstream of Cdk5 comprise a set of biomarkers for Cdk5-dependent human NE tumors. The combination of these biomarkers with pathway specific therapies currently under development will constitute a coupled diagnostic-therapeutic regimen for personalized treatment of NE cancer patients.

Citation Format: Angela M. Carter, Rahul Telange, Sarah Oltmann, Fiemu Nwariaku, Bruce Robinson, Elizabeth Grubbs, James Bibb. Biomarkers of Cdk5 driven neuroendocrine tumors. [abstract]. In: Proceedings of the AACR Precision Medicine Series: Cancer Cell Cycle - Tumor Progression and Therapeutic Response; Feb 28-Mar 2, 2016; Orlando, FL. Philadelphia (PA): AACR; Mol Cancer Res 2016;14(11_Suppl):Abstract nr A33.

AN AGGRESSIVE TEMPORAL BONE SDHC PARAGANGLIOMA ASSOCIATED WITH INCREASED HIF-2α SIGNALING

OBJECTIVE

To describe a patient with a germline succinate dehydrogenase (SDHC) gene mutation presenting with primary hyperparathyroidism and a large catecholamine-producing temporal bone paraganglioma (PGL).

METHODS

Evaluation of a SDHC mutation-positive PGL tumor biology using staining for tyrosine hydroxylase (TH), hypoxia-inducible factors 1α (HIF-1α) and 2α (HIF-2α).

RESULTS

A 66-year-old man was noted to have a lytic skull base mass during work-up for his primary hyperparathyroidism. Biochemical evaluation with 24-hour urine catecholamines and metanephrines revealed marked elevation of norepinephrine and normetanephrine. Genetic testing revealed a germline SDHC mutation. A partial excision of skull base tumor was performed, which upon further examination revealed PGL. Immunohistochemistry of skull base PGL demonstrated heavy expression of TH and HIF-2α but reduced expression of HIF-1α. The remaining skull base PGL was treated with adjuvant radiation therapy. The patient's normetanephrine levels significantly decreased after surgery and radiation.

CONCLUSION

Here, we report an unusual case of a patient presenting with a germline SDHC mutation-related functional PGL along with concomitant primary hyperparathyroidism. The present case illustrates that overexpression of HIF-2α but not of HIF-1α is linked to the pathogenesis of SDHC mutation-related PGL, and it may be responsible for the aggressive clinical behavior of a usually indolent course of SDHC-related PGLs.

Abstract 3567: Identification of potential biomarkers and novel therapeutic candidates for neuroendocrine cancer

Neuroendocrine (NE) cancers originate from secretory cells of the body's various endocrine structures. Surgical resection is the primary treatment for these tumors. However, the majority of NE cancers are metastatic at the time of detection and no effective adjuvant therapies exist for primary NE tumors or their metastases. Patients often develop two or more NE cancers, a syndrome termed multiple endocrine neoplasia (MEN). DNA sequencing has lead to breakthroughs in the identification of the causes of familial forms of the four types of MEN syndromes. Mutations in a protein of unknown function, menin, are associated with MEN1. Mutations in the receptor tyrosine kinase RET are linked to MEN2 and MEN3. The cyclin-dependent kinase inhibitor, CDNK1B, is mutated in MEN4. Unfortunately, a large percentage of NE cancers are sporadic, resulting from somatic mutations, and a high percentage of these do not harbor menin, RET, or CDNK1B mutations. Due to the lack of development of successful adjuvant therapies there has been little improvement in survival rates of NE cancer patients in the past several decades. Thus, there is a great need for the elucidation of signaling molecules that promote NE tumorigenesis in order to guide the development of novel and effective treatments for this family of cancers.

Our laboratory has found that cyclin-dependent kinase 5 (Cdk5) is an important tumorigenic signaling molecule in sporadic medullary thyroid carcinoma (MTC), a type of NE cancer that originates from calcitonin-producing C cells in the thyroid. New data supports a role for Cdk5 in multiple types of NE cancer and provides a new prospective from which to explore their causes. Cdk5 is expressed in many NE cancers and inhibition of Cdk5 activity blocks growth of NE cancer cell lines. Phosphoproteomic analysis of growing versus arrested MTC tumors, induced by expression of the Cdk5 activator p25 in our transgenic mouse model of MTC, revealed elevation of over 200 phosphorylation sites. We have used short interfering peptides (SIPs) to selectively target a set of these phosphorylation sites and found that 15 of these SIPs blocked growth of NE cancer cell lines. Phosphorylation state specific antibodies were generated to several of these sites and phosphorylation levels were confirmed to be decreased in arrested MTC tumors. In conclusion, 1) multiple types of NE cancer cells are dependent on Cdk5 activity for growth, 2) phosphorylation of multiple signaling proteins is elevated downstream of Cdk5, and 3) select inhibition of these pathways blocks growth of NE cancer cells.

Future studies will focus on analysis of these phosphoproteins in human NE tumors to validate of them as biomarkers for targeted cancer therapies as well as exploration of these phosphoproteins as direct targets for developing new therapeutics that are effective against NE cancers.

Citation Format: Angela Carter, Karine Pozo, Chun-Feng Tan, Fiemu Nwariaku, James Bibb. Identification of potential biomarkers and novel therapeutic candidates for neuroendocrine cancer. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 3567. doi:10.1158/1538-7445.AM2015-3567

Temperature-sensitive polymer-coated magnetic nanoparticles as a potential drug delivery system for targeted therapy of thyroid cancer

The objective of this work was to develop and investigate temperature-sensitive poly(N-isopropylacrylamide-acrylamide-allylamine)-coated iron oxide magnetic nanoparticles (TPMNPs) as possible targeted drug carriers for treatments of advanced thyroid cancer (ATC). These nanoparticles were prepared by free radical polymerization of monomers on the surface of silane-coupled iron oxide nanoparticles. In vitro studies demonstrated that TPMNPs were cytocompatible and effectively taken up by cancer cells in a dose-dependent manner. An external magnetic field significantly increased nanoparticle uptake, especially when cells were exposed to physiological flow conditions. Drug loading and release studies using doxorubicin confirmed the temperature-responsive release of drugs from nanoparticles. In addition, doxorubicin-loaded nanoparticles significantly killed ATC cells when compared to free doxorubicin. The in vitro results indicate that TPMNPs have potential as targeted and controlled drug carriers for thyroid cancer treatment.

Inhibition of tumor angiogenesis by the matrix metalloproteinase-activated anthrax lethal toxin in an orthotopic model of anaplastic thyroid carcinoma

Patients with anaplastic thyroid carcinoma (ATC) typically succumb to their disease months after diagnosis despite aggressive therapy. A large percentage of ATCs have been shown to harbor the V600E B-Raf point mutation, leading to the constitutive activation of the mitogen-activated protein kinase pathway. ATC invasion, metastasis, and angiogenesis are in part dependent on the gelatinase class of matrix metalloproteinases (MMP). The explicit targeting of these two tumor markers may provide a novel therapeutic strategy for the treatment of ATC. The MMP-activated anthrax lethal toxin (LeTx), a novel recombinant protein toxin combination, shows potent mitogen-activated protein kinase pathway inhibition in gelatinase-expressing V600E B-Raf tumor cells in vitro. However, preliminary in vivo studies showed that the MMP-activated LeTx also exhibited dramatic antitumor activity against xenografts that did not show significant antiproliferative responses to the LeTx in vitro. Here, we show that the MMP-activated LeTx inhibits orthotopic ATC xenograft progression in both toxin-sensitive and toxin-resistant ATC cells via reduced endothelial cell recruitment and subsequent tumor vascularization. This in turn translates to an improved long-term survival that is comparable with that produced by the multikinase inhibitor sorafenib. Our results also indicate that therapy with the MMP-activated LeTx is extremely effective against advanced tumors with well-established vascular networks. Taken together, these results suggest that the MMP-activated LeTx-mediated endothelial cell targeting is the primary in vivo antitumor mechanism of this novel toxin. Therefore, the MMP-activated LeTx could be used not only in the clinical management of V600E B-Raf ATC but potentially in any solid tumor.

The many faces of pheochromocytoma

OBJECTIVE

To recognize and manage pheochromocytomas in unusual settings.

METHODS

Three case reports are presented with clinical, biochemical, imaging, and operative findings. The pitfalls in diagnosis of pheochromocytomas and management are addressed.

RESULTS

We begin with a 27-yr-old gravida 2, para 1 Caucasian woman with unexplained tachycardia and hypertension during a routine pre-natal visit at 30 weeks estimated gestational age. Urinary studies revealed elevated catecholamines. Magnetic resonance imaging localized a 6.6-cm right adrenal mass with features consistent with a pheochromocytoma. She was medically managed with phenoxybenzamine and propranolol until 35 weeks, after which she underwent a combined Cesarean section, and open right adrenalectomy. Another patient, a 36-yr-old African-American woman presented to a hospital in cardiac arrest, with elevated serum troponins, and underwent cardiac catheterization, which revealed normal coronary arteries. A computed tomography (CT) scan revealed a left adrenal mass and CT-guided biopsy was consistent with a pheochromocytoma, although prior studies were negative. Finally, we present a 49-yr-old Caucasian woman who had a right adrenalectomy 10 yr prior and presented to the clinic with fluctuating blood pressures, headaches, and palpitations. Further testing revealed she had a recurrent metastatic pheochromocytoma. The challenges behind treating these patients are further explored.

CONCLUSION

Antenatal diagnosis of pheochromocytoma, though challenging, is associated with lower maternal and fetal morbidity and mortality. The differential diagnosis for cardiac arrest in the presence of normal coronary arteries should include a pheochromocytoma. Finally, treatment with iodinated metaiodobenzylguanidine may be a therapeutic option for those patients with metastatic pheochromocytomas.

Defining the research agenda for surgical infection: a consensus of experts using the Delphi approach

BACKGROUND

A substantial proportion of operative procedures are complicated by infections, either remote from or related to the surgical site. These infections account for substantive morbidity and health care costs. With limited research funds available to study interventions designed to either prevent or reduce the morbidity associated with infections in surgical patients, we developed a research agenda to develop priorities to aid in study design and to focus both human and capital resources more effectively.

METHODS

A Delphi survey approach was used. Consensus was developed among experts in the field of surgical infection and the membership of the Surgical Infection Society.

RESULTS

Thirty-six experts generated a total of 62 questions that were submitted for two rounds of consensus ranking. A total of 31 questions were ranked in the final round and are available at www.sisna.org. The most highly ranked question was "Does strict glycemic control compared with standard care reduce the risk of surgical site infection in patients undergoing abdominal surgery?" Most of the questions had little available data, suggesting these are both important and necessary areas for further research.

CONCLUSIONS

This research agenda, developed by a consensus of experts, provides direction and focus to the development of interventional trials geared toward reducing the morbidity associated with infections in surgical patients.

A comparison of complications associated with colostomy reversal versus ileostomy reversal

BACKGROUND

The incidence of complications after reversal of Hartmann's procedure is unknown. This study compares the morbidity of Hartmann's reversal versus loop ileostomy reversal.

METHODS

Two groups of 20 patients were studied retrospectively over a 5-year period. One group underwent Hartmann's takedown, and the other underwent loop ileostomy takedown. Postoperative complications were compared between the 2 groups.

RESULTS

Similar demographics were noted between each group. The most common initial indications for Hartmann's procedure were diverticulosis (11 patients, 55%) and colon cancer (4 patients, 20%). For patients who had undergone colectomy with primary anastomosis and ileostomy, colon cancer was the most common indication (12 patients, 60%) followed by diverticulosis (3 patients, 15%). Complications were more common after Hartmann reversal than loop ileostomy reversal (16 complications/11 patients versus 6 complications/4 patients, P = .047).

CONCLUSION

Segmental colonic excision with anastomosis and loop ileostomy may be an attractive alternative to minimize morbidity with stoma reversal.

RET signals through focal adhesion kinase in medullary thyroid cancer cells

BACKGROUND

The RET proto-oncogene is implicated in medullary thyroid cancer (MTC) and has been shown to signal indirectly to focal adhesion kinase (FAK) in cell types other than MTC. We have previously shown that FAK is phosphorylated in MTC cells. We hypothesized that inhibition of RET with pharmacologic inhibitors or by depletion with siRNA would decrease FAK phosphorylation in MTC cells, thereby implicating a RET-FAK signaling pathway.

METHODS

Human MTC cells (TT cells) were treated with pharmacologic inhibitors or transfected with RET siRNA. Total protein was detected by immunoblotting. Phosphorylated FAK was detected by immunoprecipitating total FAK and immunoblotting with antiphosphotyrosine.

RESULTS

Treatment of MTC cells with the inhibitor PP2 significantly inhibited RET phosphorylation and, to a lesser extent, FAK phosphorylation. Imatinib mesylate inhibited FAK phosphorylation only at high doses. RET siRNA significantly decreased RET expression and FAK phosphorylation.

CONCLUSIONS

RET signals through FAK in MTC cells. Whether this is due to a direct or indirect interaction is not yet clear. PP2 or a similar inhibitor might be a useful treatment for MTC.

Rebleeding and survival after acute lower gastrointestinal bleeding

BACKGROUND

Previous studies of acute lower gastrointestinal bleeding (LGIB) have focused on evaluation and therapy. Measurement of long-term outcome has been rare. The purpose of this study was to document rebleeding and survival rates in patients with acute LGIB.

METHODS

A retrospective review of all patients undergoing technetium-labeled red blood cell scans for LGIB from January of 1997 to December of 2002 was performed. Rebleeding was defined as identification of enteric bleeding requiring a transfusion 2 or more weeks after the initial bleeding episode.

RESULTS

A total of 119 patients met inclusion criteria. Rebleeding was documented in 14 of 102 patients surviving for more than 2 weeks. The actuarial rebleeding rate was 15% at 2 years. No factors were identified that portended a higher likelihood of rebleeding. The 30-day mortality was 18% and the median survival was 60 months for the entire cohort. Of the 36 patients in whom cause of death was documented, 4 died of surgical complications and a single patient died as a direct result of hemorrhage.

CONCLUSIONS

Rebleeding after an initial episode of LGIB occurs in a small percentage of individuals. Although survival is poor for patients with LGIB, few patients die as a direct consequence of hemorrhage.

Incidence and predictors of appendiceal tumors in elderly males presenting with signs and symptoms of acute appendicitis

BACKGROUND

Patients with appendiceal tumors (AT) frequently present with the same signs and symptoms as acute appendicitis (AA). The purpose of this study was to identify the incidence of AT in a population of patients greater than 60 years of age thought to have AA, and to identify presenting factors that can help differentiate the 2 disease processes.

METHODS

An institutional review board-approved, retrospective review was performed identifying all patients greater than 60 years old who underwent either appendectomy or colectomy after presenting with signs and symptoms of AA from Janaury 1997 to April 2004. Patient records were examined for demographic variables, presenting signs and symptoms, and pathology.

RESULTS

A total of 34 patients fit the entry criteria; 8 (24%) had AT. Average duration of symptoms was significantly longer (4.9 +/- 1.9 versus 2.3 +/- 0.3 days; P = 0.01) and hematocrit lower (36.5 +/- 2.3 versus 42.4 +/- 1.0%; P = 0.01) for patients with AT compared with patients with AP. No other significant differences in presenting signs and symptoms were noted.

CONCLUSIONS

There is an increased incidence of appendiceal neoplasms among elderly patients presenting with signs and symptoms of AA. Distinction between AT and appendicitis is difficult preoperatively, but AT should be suspected when patients present with longer duration of symptoms or reduced hematocrit.

Bile salt exposure causes phosphatidyl-inositol-3-kinase-mediated proliferation in a Barrett's adenocarcinoma cell line

BACKGROUND

The mechanisms by which gastroesophageal reflux promotes malignant progression in Barrett's esophagus are poorly understood. The phosphatidylinositol-3-kinase (PI3 kinase)/Akt pathway regulates proliferation and apoptosis. We hypothesized that the PI3 kinase/Akt pathway mediates the pro-proliferative and antiapoptotic effects of bile.

METHODS

The Barrett's adenocarcinoma cell line, SEG-1, was exposed to the conjugated bile salt, glycochenodeoxycholic acid (GCDA). Cell number was measured by the MTT incorporation assay and by Coulter counter. PI3 kinase/Akt activity was inferred from Western blots of phosphorylated and total Akt. Proliferation and apoptosis were determined by BrdU incorporation and cell death ELISA.

RESULTS

A dose-dependent cell number increase was seen with a 20-minute exposure to GCDA. On Western blot, 200 micromol/L GCDA caused a 3-fold increase in Akt phosphorylation within 20 minutes, which was inhibited by 90% with the addition of PI3 kinase inhibitor, LY294002. LY294002 produced dose-dependent inhibition of GCDA-induced cell number increases. 200 micromol/L GCDA decreased apoptosis by 25%. Addition of LY294002 did not completely inhibit the antiapoptotic effect of bile.

CONCLUSIONS

Bile salts activate the PI3 kinase/Akt signaling pathway and stimulate cell growth in SEG-1. The majority of this PI3 kinase-mediated effect is secondary to increases in proliferation rather than to decreases in apoptosis.

The association of pretreatment health-related quality of life with surgical complications for patients undergoing open surgical resection for colorectal cancer

OBJECTIVE

The purpose of this study was to define the association between pretreatment health-related quality of life (HRQL) and surgical complications for patients with colorectal cancer.

SUMMARY BACKGROUND DATA

For patients with colorectal cancer, surgical complications arise from an interaction between underlying medical comorbidity, colorectal cancer severity, and quality and type of treatment provided. Measurement of HRQL provides a summarization of well-being in the context of medical comorbidity and colorectal cancer severity. The summarization of these factors may be useful in prospective risk assessment of patients about to undergo surgery for colorectal cancer.

METHODS

A single-institution, prospective, cohort study of patients with colorectal adenocarcinoma was performed from August 1, 1999, to March 31, 2002. Before treatment, all participants completed Medical Outcomes Survey SF-36 (SF-36); after the first year of the study, patients also completed the colorectal cancer module of the Functional Assessment of Cancer Therapy survey (FACT-C). Information was collected on demographics, treatment, tumor variables, and complications.

RESULTS

Ninety-seven patients have undergone open resection of their colorectal cancer. All patients completed SF-36; 65 completed FACT-C. Thirty patients (31%) experienced complications, including 4 (4%) deaths. Age, race, albumin level, American Society of Anesthesia class, specialty surgical training, tumor location, and stage were not associated with complications in univariate analysis. Patients experiencing surgical complications had significantly lower HRQL scores on SF-36 Social Functioning, General Health Perception, and Mental Health Index scales as well as the Mental Health Component summary score. FACT-C Social/Family, Emotional, Functional Well-Being scores, and the Colorectal Cancer Concerns score were also significantly lower for patients sustaining complications. When these HRQL scales were examined in a multivariate model including albumin level, tumor location, and ASA class, SF-36 Social Functioning (Odds Ratio [OR] = 0.98; 95% Confidence Interval [CI] = 0.97-0.99) and FACT-C Colorectal Cancer Concerns (OR = 0.89; 95% CI = 0.79-0.99) scales retained a significant association with complications.

CONCLUSIONS

Pretreatment HRQL scores as measured by several scales of SF-36 and FACT-C were significantly associated with complications. Future studies should concentrate on defining the predictive role of HRQL in determining surgical outcome for patients with colorectal cancer.

Surgical complications exert a lasting effect on disease-specific health-related quality of life for patients with colorectal cancer

BACKGROUND

For individual patients with colorectal cancer, health-related quality of life (HRQL) after treatment is a function of several factors that include preexisting medical conditions, the disease burden, and the treatment that is rendered. The purpose of this study was to identify the factors that were associated with posttreatment HRQL.

METHODS

At baseline and again at 12 months after diagnosis, patients completed the colorectal cancer-specific HRQL survey: Functional Assessment of Cancer Therapy (FACT-C). Univariate and multivariate analyses were performed to test the association between patient-, tumor-, and treatment-related variables and 12-month FACT-C total scores.

RESULTS

Seventy-one patients completed the FACT-C at diagnosis and subsequently underwent open surgical removal of their primary tumor; 63 patients completed the 12-month survey. In univariate analysis, only chronic obstructive pulmonary disease at diagnosis or the occurrences of perioperative complications were associated with a reduction in 12-month HRQL scores. Considering both the diagnosis of chronic obstructive pulmonary disease and the occurrence of perioperative complications, along with the patient's FACT-C total score at diagnosis, age, tumor location, and stage of disease in a multivariate model, only the perioperative complications (odds ratio, 10.5; 95% CI, 2.1-52) and FACT-C total score at diagnosis (odds ratio, 1.04; 95% CI, 1.005-1.07) were associated significantly with a lower than median HRQL score at 12 months.

CONCLUSIONS

For patients who undergo treatment of colorectal cancer, HRQL at 1 year after diagnosis is still influenced significantly and negatively by the occurrence of surgical complications.

Directed parathyroidectomy: feasibility and performance in 100 consecutive patients with primary hyperparathyroidism

HYPOTHESIS

Directed parathyroidectomy (DP) can be successfully completed in most patients with primary hyperparathyroidism.

DESIGN AND SETTING

Retrospective review at a tertiary referral center.

PATIENTS

One hundred consecutive patients with untreated, sporadic primary hyperparathyroidism operated on by a single surgeon from April 1, 1999, through December 31, 2001.

INTERVENTIONS

Following preoperative imaging with sestamibi scintigraphy and ultrasonography, patients underwent parathyroidectomy with intraoperative parathyroid hormone monitoring using a focused approach through a limited neck incision (DP) or bilateral neck exploration (BNE) through a standard collar incision.

MAIN OUTCOME MEASURES

Extent of exploration, operative time, length of stay, morbidity, and cure.

RESULTS

Directed parathyroidectomy was completed in 70 patients and BNE in 30. Bilateral neck exploration was performed as the initial procedure in 13 patients and following intraoperative conversion from attempted DP in 17. Indications for predetermined BNE were failed preoperative localization (n = 8) and concomitant thyroid disease that required operative treatment (n = 5). The need for predetermined BNE decreased as preoperative localization improved. Intraoperative factors that necessitated conversion to BNE included persistently elevated intraoperative parathyroid hormone levels that accurately predicted multiglandular disease (n = 6), incorrect localization (n = 5), and inadequate exposure (n = 6). Operative time and length of stay were less for DP compared with BNE patients (66 vs 165 minutes and 0.5 vs 1.6 days, respectively). One patient had a temporary vocal cord paresis. All patients were eucalcemic in follow-up (4 months to 3 years).

CONCLUSIONS

With accurate preoperative localization and intraoperative parathyroid hormone monitoring, DP can be successfully completed in most patients with sporadic primary hyperparathyroidism. Patients benefit from DP, which reduces operative time and length of stay and facilitates rapid convalescence.

Focal adhesions and associated proteins in medullary thyroid carcinoma cells

BACKGROUND

In medullary thyroid carcinoma (MTC), mutations in the RET protooncogene lead to oncogenic transformation. RET activation in other cell types has been shown to cause phosphorylation of the focal adhesion-associated proteins focal adhesion kinase (FAK), paxillin, and p130(CAS). We hypothesized that adhesion-dependent signaling might be deranged in MTC cells.

METHODS

Indirect immunofluorescence was used to label beta(1) integrin, FAK, paxillin, and p130CAS. Rhodamine-labeled phalloidin was used to visualize actin microfilaments. Phosphorylated protein was detected by immunoprecipitation followed by Western blotting for phosphotyrosine. MTC cell invasiveness was quantified using a modified Boyden chamber assay.

RESULTS

Clustering of beta(1) integrin, FAK, paxillin, and p130(CAS) into focal adhesions were not detected in MTC cells under any conditions, although clustering was seen as expected in control HeLa cells. Despite this failure, FAK, paxillin and p130(CAS) were all found to be phosphorylated. Actin microfilaments were generally not seen although in a few cells, small, poorly formed microfilaments could be detected. MTC cells invaded poorly as compared with highly invasive cell lines. However a clear difference was noted between invasiveness on growth factor depleted Matrigel and regular Matrigel.

CONCLUSIONS

In MTC cells, focal adhesions are not seen in response to interaction with extracellular matrix. Consistent with this failure, actin microfilaments are absent or poorly formed and invasion is weak. Despite the absence of focal adhesions, focal adhesion proteins remain phosphorylated, even though in normal cells their signaling activity is dependent on focal adhesion formation. Deranged adhesion-dependent signaling may contribute to MTC pathogenesis.

Health-related quality of life and postoperative length of stay for patients with colorectal cancer

BACKGROUND

Length of stay (LOS) after surgery is a major determinant of resource utilization for colorectal cancer (CRC). The purpose of this study was to examine the association between pretreatment health-related quality of life (HRQL) scores and postoperative hospital LOS in a cohort of patients undergoing surgery for CRC.

METHODS

Seventy patients with biopsy-proven CRC were enrolled in an IRB-approved, prospective study. Information was collected concerning standard perioperative variables. Prior to surgery, all patients also completed the CRC-specific module of the Functional Assessment of Cancer Therapy (FACT-C). Perioperative variables and FACT-C scores were compared with LOS in both univariate and multivariate analysis. LOS for those patients scoring in the lowest quartile on FACT-C was compared with LOS for patients scoring in the remaining quartiles.

RESULTS

Median length of stay for the entire group was 6 (range 3-25) days. In univariate analysis, surgical complications (10.6 vs 6.6 days; P = 0.001) and with poorer FACT-C individual scale scores for Physical Well-Being (9.1 vs 7.3 days; P = 0.04), Functional Well-Being (9.6 vs 7.1 days; P = 0.006), and Colorectal Cancer Concerns (9.5 vs 7.1 days; P = 0.01) were all significantly associated with increased length of stay. In multivariate analysis, surgical morbidity (OR = 5.6; 95% CI 1.5-21.4), age >72 (OR = 6.0; 95% CI 1.6-23.5), and low FACT-C total score (OR = 4.2; 95% CI 1.1-15.6) were independently associated with increased LOS.

CONCLUSIONS

Pretreatment HRQL scores as measured by FACT-C may be of benefit in the prediction of LOS. Such information may be an important and currently neglected means of risk-adjusting populations undergoing surgery for colorectal cancer for this outcome.

The effect of tumor necrosis factor-alpha on microvascular permeability in an isolated, perfused lung

This study examines the hypotheses that TNF-alpha causes a dose-dependent increase in the microvascular permeability of ex vivo buffer perfused lungs that is quantitatively similar to that caused by lipopolysaccharide (LPS) or thromboxane A2 (TxA2). We also postulated that TNF-alpha potentiates the effect of interleukin-1beta (IL-1beta) or TxA2 receptor activation on pulmonary microvascular permeability. Lungs harvested from Wistar rats were perfused ex vivo with Krebs-Henseleit buffer containing 0, 10, 100, or 1000 ng/mL recombinant rat TNF-alpha. Twenty minutes later pulmonary microvascular permeability was determined by measuring the capillary filtration coefficient (Kf) using a gravimetric technique. The effect of TNF-alpha (100 ng/mL) on pulmonary Kf was compared with that of lungs exposed to LPS (400 microg/mL; E. coli 0111:B4) or a TxA2 receptor agonist (U-46619; 7 x 10(-8)). In other experiments, perfused lungs were exposed to TNF-alpha plus IL-1beta (1 ng/mL) or TNF-alpha plus U-46619 after which Kf was measured. Exposure of ex vivo buffer perfused lungs to 10-1000 ng/mL TNF-alpha had no effect on Kf whereas LPS and U-46619 was associated with a two- and six-fold increase in Kf, respectively (P < 0.05). The Kf of lungs exposed to TNF-alpha plus IL-1 was similar to that of lungs exposed to TNF-alpha alone. Lastly, the Kf of lungs exposed to TNF-alpha plus U-46619 was not different than that of lungs exposed to U-46619 alone. In conclusion, TNF-alpha at least when administered for a relatively brief period of time does not affect microvascular permeability in an isolated, buffer-perfused lung model.

Mechanisms of pulmonary microvascular dysfunction during severe burn injury

Even in the absence of inhalational injury, acute lung injury is a common cause of morbidity and mortality for patients sustaining severe burns. Other than general supportive measures, there are few therapeutic options for improving survival in these critically ill patients. Numerous clinical and laboratory studies have implicated tumor necrosis factor (TNF)-a and neutrophils as important participants in the pathogenesis of burn-induced lung injury. There is, however, little information regarding the mechanism by which these and other pro-inflammatory mediators affect the movement of fluid and protein across the microvascular barrier into the interstitium of the lung. In addition to reviewing the evidence implicating TNF-a and neutrophils in the pathophysiology of burn-induced lung injury, this report summarizes current theories regarding potential mechanisms by which these mediators may alter microvascular barrier function to lead ultimately to the development of pulmonary edema.

Improving operative performance using a laparoscopic hernia simulator

BACKGROUND

Traditionally, the acquisition of surgical skill has occurred entirely in the operating room. To meet the expanding challenges of cost containment and patient safety, novel methods of surgical training utilizing ex-vivo workstations are being developed. The purpose of our study was to evaluate the impact of a laparoscopic training curriculum on surgical residents' operative performance.

METHODS

Twenty-one surgery residents completed baseline laparoscopic total extraperitoneal (TEP) hernia repairs. Operative performance was evaluated using a validated global assessment tool. Each resident was then randomized to a control group or a trained group. A CD ROM, video, and simulator were used for training. At the end of the study, each resident's operative performance was again evaluated.

RESULTS

Improvement was significantly greater in the trained group in five of the eight individual global assessment areas as well as the composite score (P <0.05). Questionnaire data suggested that training resulted in improved understanding of the TEP hernia repair (P = 0.01) and an increased willingness to offer the operation to patients with nonrecurrent unilateral hernias (P = 0.02).

CONCLUSIONS

A multimodality laparoscopic TEP hernia curriculum improves residents' knowledge of the TEP hernia repair and comfort in performing the procedure, and may also improve actual operative performance.

Burn-activated neutrophils and tumor necrosis factor-alpha alter endothelial cell actin cytoskeleton and enhance monolayer permeability

BACKGROUND

This study examined the hypothesis that exposure of an endothelial cell (EC) monolayer to tumor necrosis factor-alpha (TNF-alpha) and that burn-activated neutrophils alter EC actin cytoskeleton and enhance the permeability of the monolayer.

METHODS

Neutrophils were harvested from rats that had undergone a 45% surface area burn (BURN-neutrophil) or uninjured control rats. ECs were grown on polyester filters or fibronectin-coated glass slides and exposed for 4 hours to media, TNF-alpha (100 ng/mL), or TNF-alpha plus BURN-neutrophil or uninjured control rats (10(7) cells). Monolayer permeability was assessed by measuring the flux of albumin across the cells. EC surface area and microfilament number and length were determined by the staining of actin microfilaments with rhodamine phalloidin followed by fluorescent microscopy.

RESULTS

The amount of albumin that moved across the monolayer in response to TNF-alpha plus BURN-neutrophil was twice that of media alone (P <.05) or TNF-alpha alone (P <.05). The number and length of actin microfilaments in ECs exposed to TNF-alpha plus BURN-neutrophil were significantly less than that of cells exposed to media alone or TNF-alpha alone.

CONCLUSIONS

These data are consistent with a hypothesis that TNF-alpha plus BURN-neutrophil affect endothelial monolayer permeability by altering EC actin cytoskeletal organization.

A clinical pathway for inguinal hernia repair reduces hospital admissions

BACKGROUND

Clinical pathways have been advocated as a means to improve and standardize patient care while reducing costs through improved efficiency. This study examines the hypothesis that development of a clinical pathway reduces hospital admissions in a Veterans Affairs (VA) medical center.

MATERIALS AND METHODS

For the year prior to June 1997, 168 elective inguinal herniorrhaphies were performed. This constituted the prepathway (pre-P) group. One hundred ninety-six elective inguinal herniorrhaphies were performed during the year following institution of the clinical pathway-the postpathway (post-P) group.

RESULTS

Hospital admissions were compared between the two groups. In the pre-P group 61 of the 168 patients (36%) were admitted while 29 of the 196 patients (15%) in the post-P group were admitted (P < 0.001). In the pre-P group 27 of the 53 patients reviewed (51%) had either no justification or inadequate justification for admission. In the post-P group 8 of the 29 patients admitted (28%) had inadequate justification (pre-P vs post-P, P = 0.124). Common reasons for admission included pain, perioperative complications, and concurrent medical problems or surgical procedures. The most common single cause other than pain was urinary retention. The average age of patients requiring admission was greater both pre-P and post-P.

CONCLUSIONS

We conclude that institution of a clinical pathway for inguinal herniorrhaphy decreased hospital admissions. The reasons for this decrease are probably multifactorial and include improvements in physician and staff awareness. The decrease in unnecessary admissions should result in more efficient use of hospital resources.

The validity of quick intraoperative parathyroid hormone assay: an evaluation in seventy-two patients based on gross morphologic criteria

BACKGROUND

Parathyroidectomy for primary hyperparathyroidism has conventionally required identification of all parathyroid glands with excision of grossly abnormal glands. Using this approach, cure rates exceed 95%. Directed cervical exploration has been advocated using quick intraoperative parathyroid hormone (QPTH) assay with preoperative localization. Adoption of this approach requires validation of the accuracy of QPTH assay.

METHODS

Patients with primary hyperparathyroidism undergoing bilateral neck exploration during a 31-month period were reviewed. Uniglandular (UGD) or multiglandular (MGD) disease was determined by gross morphologic criteria. QPTH assays were performed before skin incision and at 5, 10, and 20 minutes after excision of each abnormal gland. A 10-minute QPTH decrease of 50% from baseline levels indicated curative excision. These data were not used to guide extent of exploration or tissue resection.

RESULTS

Of 72 patients, 55 (76%) had UGD and 17 (24%) had MGD. QPTH assay accurately predicted the disease state in 89%. Four (7%) UGD patients did not have an appropriate QPTH decline at 10 minutes. Four (24%) MGD patients had an inappropriate QPTH decline at 10 minutes.

CONCLUSIONS

Using QPTH guided exploration, 6% (4 of 72) of patients would undergo unnecessary extended exploration and 6% (4 of 72) (95% CI, 1% to 13%) may require reoperation for unidentified MGD. These results validate the accuracy of QPTH assay.

Inhibition of selectin- and integrin-mediated inflammatory response after burn injury

Inflammation and microvascular injury in the areas adjacent to burn wounds produces extension of postburn tissue necrosis. Leukocytes are potent mediators of the local inflammatory response preceding tissue necrosis, and the selectin and integrin adhesion molecules have been implicated in leukocyte-mediated tissue destruction. We sought to examine the role of L-selectin (CD62-L) and CD18 in leukocyte accumulation and tissue necrosis following burn injury. New Zealand White rabbits (n = 36) were subjected to burn injury and were randomized to treatment with saline (control) or monoclonal antibodies to L-selectin or CD18. Animals given the anti-L-selectin antibody demonstrated reduced immunohistochemical evidence of leukocyte accumulation at 24 hr postinjury but did not show improved wound perfusion or reduced tissue necrosis. Animals in the anti-CD18 group showed significantly improved tissue survival and improved tissue perfusion but had grades of leukocyte accumulation similar to those in the control group. These observations suggest that leukocyte accumulation is partially L-selectin dependent and that leukocyte accumulation alone is not sufficient to cause changes in blood flow and tissue destruction, both of which appear to be largely CD18 mediated.

Role of CD14 in hemorrhagic shock-induced alterations of the monocyte tumor necrosis factor response to endotoxin

OBJECTIVE

To determine if the shock-induced alterations in whole blood monocyte tumor necrosis factor (TNF) response are mediated by the CD14 receptor.

DESIGN

Prospective controlled animals experiments.

MATERIALS AND METHODS

New Zealand White rabbits (n = 15) were subjected to hemorrhage and resuscitation. Blood samples obtained before shock and 24, 72, and 120 hours after shock were stimulated with lipopolysaccharide in the presence or absence of the anti-CD14 monoclonal antibody, 63D3. Tumor necrosis factor was assayed using L929 cells.

MEASUREMENTS AND MAIN RESULTS

There are no detectable TNF activity in unstimulated blood. The CD14 inhibition resulted in a 55% reduction in baseline TNF activity. After shock, there was a marked increase in TNF activity with lipopolysaccharide stimulation. Addition of 63D3 resulted in a dose-dependent 95% reduction in TNF activity at 24 and 72 hours after shock, (p < 0.05).

CONCLUSION

The enhanced whole blood monocyte TNF response after hemorrhage is CD14 dependent.