Search tips
Search criteria

Results 1-25 (272)

Clipboard (0)

Select a Filter Below

Year of Publication
more »
Document Types
1.  Therapeutic targeting of pancreatic cancer utilizing sigma-2 ligands 
Surgery  2012;152(3 0 1):S152-S156.
One major barrier in the development of pancreas cancer therapeutics is the selective delivery of the drugs to their cellular targets. We have developed previously several sigma-2 ligands and reported the discovery of a component of the receptor for these ligands. Several sigma-2 ligands have been shown to trigger apoptosis in pancreas cancer cells. More importantly sigma-2 ligands are internalized rapidly by the cancer cells, and are capable of delivering other small molecule therapeutics. Here we review sigma-2 ligands and conjugates as a potential novel therapy suitable for investigation in patients with pancreatic cancer.
PMCID: PMC3982787  PMID: 22763259
3.  Informed consent for innovative surgery: A survey of patients and surgeons 
Surgery  2012;153(4):473-480.
Unlike new drugs and medical devices, most surgical procedures are developed outside clinical trials, without regulatory oversight. Surgical professional organizations have discussed how new procedures should be introduced into practice, without agreement on what topics informed consent discussions must include. To provide surgeons with more specific guidance, we wanted to determine what information patients and surgeons consider essential to disclose before an innovative surgical procedure.
85 attending surgeons and 383 adult postoperative patients completed surveys. Using a 6-point Likert scale, participants rated the importance of discussing 16 types of information preoperatively for 3 techniques (standard open, laparoscopic, robotic) offered for a hypothetical partial hepatectomy.
Compared with surgeons, patients placed more importance on nearly all types of information, particularly volumes and outcomes. For all 3 techniques, around 80% of patients indicated that they could not decide on surgery without being told whether it would be the surgeon’s first time doing the procedure. When considering an innovative robotic surgery, a clear majority of both patients and surgeons agreed that it was essential to disclose the procedure’s novel nature, potentially unknown risks and benefits, and whether it would be the surgeon’s first time performing the procedure.
To promote informed decision making and autonomy among patients considering innovative surgery, surgeons should disclose the procedure’s novel nature, potentially unknown risks and benefits, and whether the surgeon would be performing the procedure for the first time. When accurate volumes and outcomes data are available, surgeons should also discuss these with patients.
PMCID: PMC3602241  PMID: 23218878
4.  Pre-Operative Diet Impacts the Adipose Tissue Response to Surgical Trauma 
Surgery  2012;153(4):584-593.
Short-term changes in pre-operative nutrition can have profound effects on surgery related outcomes such as ischemia reperfusions injury in pre-clinical models. Dietary interventions that lend protection against stress in animal models (e.g. fasting, dietary restriction [DR]) impact adipose tissue quality/quantity. Adipose tissue holds high surgical relevance due to its anatomic location and high tissue volume, and it is ubiquitously traumatized during surgery. Yet the response of adipose tissue to trauma under clinically relevant circumstances including dietary status remains poorly defined. We hypothesized that pre-operative diet alters the adipose tissue response to surgical trauma.
A novel mouse model of adipose tissue surgical trauma was employed. Dietary conditions (diet induced obesity [DIO], pre-operative DR) were modulated prior to application of surgical adipose tissue trauma in the context of clinically common scenarios (different ages, simulated bacterial wound contamination). Local/distant adipose tissue phenotypic responses were measured as represented by gene expression of inflammatory, tissue remodeling/growth, and metabolic markers.
Surgical trauma had a profound effect on adipose tissue phenotype at the site of trauma. Milder but significant distal effects on non-traumatized adipose tissue were also observed. DIO exacerbated the inflammatory aspects of this response, and pre-operative DR tended to reverse these changes. Age and LPS-simulated bacterial contamination also impacted the adipose tissue response to trauma, with young adult animals and LPS treatment exacerbating the proinflammatory response.
Surgical trauma dramatically impacts both local and distal adipose tissue biology. Short-term pre-operative DR may offer a strategy to attenuate this response.
PMCID: PMC3603342  PMID: 23274098
5.  Outcomes and Quality of Life after Partial Pancreatectomy for Noninsulinoma Pancreatogenous Hypoglycemia from Diffuse Islet Cell Disease 
Surgery  2010;148(6):1237-1246.
Noninsulinoma pancreatogenous hypoglycemia (NIPH) is a rare cause of hypoglycemia from excessive insulin secretion, especially affecting post-bariatric surgery patients. Partial pancreatectomy may control hypoglycemia; however, multiple patients experienced symptomatic relapse. Our study goal was to assess frequency and severity of recurrent symptoms postoperatively.
Demographics, preoperative testing, operative and postoperative details were reviewed for all patients who underwent pancreatic resection for NIPH at Mayo Clinic from January 1996 - December 2008. Patient records and mail surveys (including European Quality of Life Survey (EQ-5D) and Fear of Hypoglycemia Scale (FOHS-98)) were used to assess outcome.
75 patients underwent pancreatic resection for NIPH. 48 patients (70%) completed the survey (median follow-up 53 mo.). Median time to recurrent symptoms was 16 months (N=41, 87%). Despite symptom recurrence, 75% of patients reported overall improvement in quality of life, with marked reduction in psychological stress and hypoglycemic symptoms (greater than 50% decrease in FOHS-98 scores (p<0.001). Overall, half of the patients were classified as highly/moderately surgically-successful. Nevertheless, 25% of patients experienced no apparent benefit.
Although nearly 90% of NIPH patients reported recurrent symptoms suggestive of hypoglycemia, a majority reported significant improvements in QOL and marked reduction in other symptoms after pancreatic resection.
PMCID: PMC3954513  PMID: 21134557
noninsulinoma pancreatogenous hypoglycemia syndrome (NIPHS); adult-onset nesidioblastosis; post-gastric bypass hypoglycemia
6.  Variation in Susceptibility of Human Malignant Melanomas to Oncolytic Vesicular Stomatitis Virus 
Surgery  2012;153(3):333-343.
Vesicular stomatitis virus (VSV) is a novel, anti-cancer therapy that selectively targets cancer cells with defective antiviral responses; however, not all malignant cells are sensitive to the oncolytic effects of VSV. Herein, we explore the mechanistic determinants of mutant M protein VSV (M51R-VSV) susceptibility in malignant melanoma cells.
Cell viability after VSV infection was measured by the 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium (MTS) viability assay in a panel of melanoma cell lines. VSV infectability, viral protein synthesis and viral progeny production were quantified by flow cytometry, 35S-methionine electrophoresis, and viral plaque assays, respectively. Interferon (IFN) responsiveness was determined using MTS assay after β-IFN pre-treatment. Xenografts were established in athymic nude mice and treated with intratumoral M51R-VSV.
Cell viability after M51R-VSV infection at a multiplicity of infection (MOI) of 10 pfu/mL, 48 hours post-infection) ranged between 0±1 and 59±9% (mean ± standard deviation). Sensitive cell lines supported VSV infection, viral protein synthesis, and viral progeny production. In addition, when pre-treated with β-IFN, sensitive cells became resistant to M51R-VSV, suggesting that IFN-mediated antiviral signaling is defective in these cells. In contrast, resistant melanoma cells do not support VSV infection, viral protein synthesis, or viral replication, indicating that anti-viral defenses remain intact. In a murine xenograft model, intratumoral M51R-VSV treatment decreased tumor growth relative to controls after 26 days in SK-Mel 5 (−21±19% vs. 2100±770%, p<0.0001) and SK-Mel 3 (2000±810% vs 7000±3000%, p=0.008) established tumors.
M51R-VSV is a viable, anti-cancer therapy, but susceptibility varies among melanomas. Future work will exploit specific mechanisms of resistance to expand the therapeutic efficacy of M51R-VSV.
PMCID: PMC3561511  PMID: 23102637
7.  Liver resection for liver metastases from nondigestive endocrine cancer: extrahepatic disease burden defines outcome 
Surgery  2012;151(6):10.1016/j.surg.2011.12.025.
For patients with hepatic nondigestive endocrine metastases (HNEM), the role of liver resection is not well defined.
We reviewed outcomes for patients who underwent liver resection for HNEM at 2 centers to identify predictors of survival.
From 1991 to 2010, 51 patients underwent liver resection for HNEM. Primary tumor types were adrenal gland (26), thyroid (11), testicular germ cell (9), and ovarian granulosa cell (5). Twenty-eight patients (55%) had synchronous or early (diagnosed within 12 months after primary tumor resection) liver metastases. At liver resection, 26 patients (51%) had extrahepatic metastases, and 7 (14%) had 2 or more sites of extrahepatic metastases. Thirty-two patients (63%) had major liver resection, and 19 (37%) had an extrahepatic procedure. Ninety-day postoperative morbidity and mortality rates were 27% and 2%, respectively. After median follow-up of 20 months (range: 1–144 months), 5-year overall and recurrence-free survival rates were 58% and 37%, respectively. Survival was not affected by primary tumor type. In multivariate analysis, 2 or more sites of extrahepatic metastases (hazard ratio [HR] = 4.80, 95% confidence interval [CI] = 1.18–19.50, P = .028) and interval of 12 months or less between primary tumor resection and diagnosis of liver metastases (HR = 5.33, 95% CI = 1.11–25.71, P = .037) were associated with worse overall survival after liver resection.
For selected patients, liver resection for HNEM is associated with long-term survival. The number of extrahepatic sites of metastasis and the timing of appearance of liver metastases should be considered in patient selection.
PMCID: PMC3880181  PMID: 22306838
8.  Preoperative basal calcitonin and tumor stage correlate with postoperative calcitonin normalization in patients undergoing initial surgical management of medullary thyroid carcinoma 
Surgery  2011;150(6):10.1016/j.surg.2011.09.043.
The optimal initial operative management of medullary thyroid cancer (MTC) and the use of biomarkers to guide the extent of operation remain controversial. We hypothesized that preoperative serum levels of calcitonin and carcinoembryonic antigen (CEA) correlate with extent of disease and postoperative levels reflect the extent of operation performed.
We assessed retrospectively clinical and pathologic factors among patients with MTC undergoing at least total thyroidectomy; these factors were correlated with biomarkers using regression analyses.
Data were obtained from 104 patients, 28% with hereditary MTC. Preoperative calcitonin correlated with tumor size (P < .001) and postoperative serum calcitonin levels (P = .01) after multivariable adjustment for lymph node positivity, extent of operation, and hereditary MTC. No patient with a preoperative calcitonin level of <53 pg/mL (n = 20) had lymph node metastases. TNM stage (P = .001) and preoperative calcitonin levels (P = .04), but not extent of operation, independently correlated with the failure to normalize postoperative calcitonin. Postoperative CEA correlated with positive margins (adjusted P = 04). Neither preoperative nor postoperative CEA was correlated with lymph node positivity or extent of surgery.
Preoperative serum calcitonin and TMN stage, but not extent of operation, were independent predictors of postoperative normalization of serum calcitonin levels. Future studies should evaluate preoperative serum calcitonin levels as a determinate of the extent of initial operation.
PMCID: PMC3880195  PMID: 22136837
9.  Parenteral Nutrition Suppresses the Bactericidal Response of the Small Intestine 
Surgery  2012;153(1):17-24.
Parenteral nutrition (PN) increases infectious risk in critically ill patients compared with enteral feeding. Previously, we demonstrated that PN feeding suppresses the concentration of the Paneth cell antimicrobial protein secretory phospholipase A2 (sPLA2) in the gut lumen. sPLA2 and other Paneth cell proteins are released in response to bacterial components, such as lipopolysaccharide (LPS), and they modulate the intestinal microbiome. Since the Paneth cell protein sPLA2 was suppressed with PN feeding, we hypothesized PN would diminish the responsiveness of the small bowel to LPS through reduced secretions and as a result exhibit less bactericidal activity.
The distal ileum was harvested from ICR mice, washed, and randomized for incubation with LPS (0, 1, or 10 μg/mL). Culture supernatant was collected and sPLA2 Activity was measured. Bactericidal activity of the ileum segment secretions was assessed against P. aeruginosa with and without a sPLA2 inhibitor at two concentrations, 100nM and 1μM. ICR mice were randomized to Chow or PN for 5 days. Tissue was collected for immunohistochemistry (IHC) and ileal segments were incubated with LPS (0 or 10 μg/mL). sPLA2 activity and bactericidal activity were measured in secretions from ileal segments.
The ileal segments responded to 10 ug/mL LPS with significantly greater sPLA2 activity and bactericidal activity. The bactericidal activity of secretions from LPS stimulated tissue was suppressed 50% and 70%, respectively, with the addition of the sPLA2-inhibitor. Chow displayed greater sPLA2 in the Paneth cell granules and secreted higher levels of sPLA2 than PN before and after LPS. Accordingly, media collected from Chow was more bactericidal than PN. IHC confirmed a reduction in Paneth cell granules after PN.
This work demonstrates that ileal segments secrete bactericidal secretions after LPS exposure and the inhibition of the Paneth cell antimicrobial protein sPLA2 significantly diminishes this. PN feeding resulted in suppressed secretion of the sPLA2 and resulted in increased bacterial survival. This demonstrates that PN significantly impairs the innate immune response by suppressing Paneth cell function.
PMCID: PMC3445757  PMID: 22698933
Parenteral Nutrition; secretory phospholipase A2; small intestine; innate immunity
10.  Lack of Interleukin-1 Signaling Results in Perturbed Early Vein Graft Wall Adaptations 
Surgery  2012;153(1):63-69.
Vein grafts fail due to wall mal-adaptations to surgical injury and hemodynamic perturbations. Interleukin-1 signaling has emerged as an important mediator of the vascular response to trauma and hemodynamically induced vascular lesions. We therefore hypothesized that interleukin-1 signaling drives early vein graft wall adaptations.
Using interleukin-1 type I receptor knockout (IL-1RI−/−) and wild-type (B6129SF2/J) mice, we investigated morphologic changes 28 days after interposition isograft from donor inferior vena cava to recipient carotid artery, without (n=19) or with (n=13) outflow restriction. The impact of mouse strain on the response to vein arterialization was also evaluated between B6129SF2/J (n=18) and C57BL/6J (n=19) mice.
No significant differences were observed in the traditional endpoints of intimal thickness and calculated luminal area, yet media+adventitia thickness of the vein graft wall of IL-1RI−/− mice was 44-52% smaller than wild-type mice, at the both proximal (P<.01, P<.01) and distal (P=.054, P<.01) portions of vein grafts, for both normal flow and low flow respectively. Compared with C57BL/6J strain, B6129SF2/J mice exhibited no difference in vein graft intimal thickness, but 2-fold higher media+adventitia thickness (P<.01).
When lacking interleukin-1 signaling, the vein graft wall adapts differently compared to the injured artery, showing typical intima hyperplasia though attenuated media+adventitia thickening. B6129SF2/J mice exhibit more media+adventitia response than C57BL/6J mice. The inflammatory networks that underlie the vein response to arterialization hold many roles in the adaptation of the total wall, thus the utility of anti-inflammatory approaches to extend the durability of vein grafts comes into question.
PMCID: PMC3488356  PMID: 22853857
interleukin-1; vein graft; wall adaptation; adventitia; mouse model
11.  Increased phospholipase A2 and lyso-phosphatidylcholine levels are associated with surfactant dysfunction in lung contusion injury in mice 
Surgery  2012;153(1):25-35.
Surfactant dysfunction is an important pathological disturbance in various forms of acute inflammatory lung injury. Previously we reported the presence of significant alterations in the composition and activity of pulmonary surfactant in blunt trauma-induced bilateral lung contusion (LC) injury in rats. This is extended here to a mouse model of unilateral LC, with a focus on compositional and functional surfactant changes associated with permeability injury and increases in activity of secretory phospholipase A2.
Surfactant-associated gene expression was not significantly altered in mice with unilateral LC injury based on Affymetrix analysis. LC mice had significant permeability injury with increased albumin and total protein in bronchoalveolar lavage (BAL) at 5, 24, 48 and 72 h post-insult compared to uninjured controls. The percent content of large surfactant aggregates was significantly depleted at all post-injury times, and pulmonary pressure-volume (P-V) mechanics and compliance were abnormal over this period. Surfactant dysfunction was evaluated in mechanistic detail at 24 h, when permeability injury and P-V changes were most prominent. At this time, activity levels of secretory phospholipase A2 (PLA2) were increased in BAL, and chromatographic analysis showed that large surfactant aggregates had decreased levels of phosphatidylcholine (PC) and increased levels of lyso-PC. These changes were accompanied by severe detriments in large aggregate surface activity by pulsating bubble surfactometry. Large aggregates from LC mice at 24 h had minimum surface tensions of only 12.6±1.1 mN/m after prolonged bubble pulsation (20 min) compared to 0.7±0.03 mN/m for uninjured controls.
These results document significant detriments in the composition and activity of pulmonary surfactant in LC injury in mice, and suggest that active synthetic phospholipase-resistant exogenous surfactants may have future utility in treating surfactant dysfunction in this clinically-important condition.
PMCID: PMC3509248  PMID: 22853859
lung surfactant; surfactant dysfunction; lung contusion; Phospholipase A2
12.  The intestinal environment of surgical injury transforms Pseudomonas aeruginosa into a discrete hypervirulent morphotype capable of causing lethal peritonitis 
Surgery  2012;153(1):36-43.
Secondary peritonitis continues to carry a high mortality rate despite aggressive use of imaging, drainage and antibiotics. Although host factors and microbial burden contribute to the outcome of peritonitis, here we propose a role bacterial virulence as a determinant of outcome from peritonitis. Bacterial virulence is an inducible trait that is activated in response to specific local “cues” that we have previously shown to be present in the mouse gut exposed to surgical stress and injury.
Pseudomonas aeruginosa was harvested following its intestinal inoculation into the cecum of mice subjected to surgical injury (30% hepatectomy) or sham surgery (controls). Harvested strains were then injected into the peritoneum of non-injured (naïve) mice and mortality determined.
P. aeruginosa harvested from the intestines of surgically injured mice caused 100% mortality whereas strains harvested from control mice caused no mortality. Among recovered strains a distinct P. aeruginosa morphotype (wrinked shape) was demonstrated to cause lethal peritonitis compared to smooth shaped strains which were non-lethal. Wrinked strains were associated with a tendency to elicit a more pro inflammatory response in mice compared to smooth shaped strains.
Surgical injury transforms the morphotype of intestinal P. aeruginosa to express a hypervirulent response in the peritoneum of mice. Enhanced virulence of intestinal pathogens in response to surgical injury may play an important role in predicting the outcome of peritonitis.
PMCID: PMC3521093  PMID: 22862900
13.  Heparin-binding epidermal growth factor-like growth factor improves intestinal barrier function and reduces mortality in a murine model of peritonitis 
Surgery  2012;153(1):52-62.
The morbidity and mortality associated with bacterial peritonitis remain high. Heparin-binding epidermal growth factor (EGF)-like growth factor (HB-EGF) is a potent intestinal cytoprotective agent. The aim of this study was to evaluate the effect of HB-EGF in a model of murine peritonitis.
HB-EGF(−/−) knockout (KO) mice and their HB-EGF(+/+) wild-type (WT) counterparts were subjected to sham operation, cecal ligation and puncture (CLP), or CLP with HB-EGF treatment (800 µg/kg IP daily). Villous length, intestinal permeability, intestinal epithelial cell (IEC) apoptosis, bacterial load in peritoneal fluid (PF) and mesenteric lymph nodes (MLN), inflammatory cytokine levels, and survival were determined.
After exposure to CLP, HB-EGF KO mice had significantly shorter villi (1.37 ± 0.13 vs 1.96 ± 0.4 relative units; P < .03), increased intestinal permeability (17.01 ± 5.18 vs 11.50 ± 4.67 nL/min/cm2; P < .03), increased IEC apoptotic indices (0.0093 ± 0.0033 vs 0.0016 ± 0.0014; P < .01), and increased bacterial counts in PF (25,313 ± 17,558 vs 11,955 ± 6,653 colony forming units [CFU]/mL; P < .05) and MLN (19,009 ± 11,200 vs 5,948 ± 2,988 CFU/mL/g; P < .01) compared with WT mice. Administration of HB-EGF to WT and HB-EGF KO mice exposed to CLP led to significantly increased villous length and decreased intestinal permeability, IEC apoptosis and bacterial counts in MLN (P < .05). Survival of HB-EGF KO mice subjected to CLP was significantly improved with administration of HB-EGF (P < .05).
HB-EGF gene KO increases susceptibility to peritonitis-induced intestinal injury, which can be reversed by administration of HB-EGF. These results support a protective role of HB-EGF in peritonitis-induced sepsis.
PMCID: PMC3573883  PMID: 22703966
14.  Thyroid surgery in octogenarians is associated with higher complication rates 
Surgery  2009;146(5):10.1016/j.surg.2009.05.004.
To determine whether thyroid surgery in patients ≥80 is associated with higher complication rates.
The incidence of thyroid nodules increases with age and little information is available regarding the risks of thyroid surgery in elderly patients.
Out of 3568 patients undergoing thyroid surgery between July 2001 and October 2007 at a single institution, the records of 90 consecutive patients ≥80 years were retrospectively reviewed and compared to a cohort of 242 randomly selected patients aged 18–79, who underwent thyroid surgery during the same time period, using SAS statistical software. Clinical variables included age group, sex, medical co-morbidities, pre-operative diagnosis, substernal component, previous surgery, final pathology, length of stay (LOS), postoperative complications and mortality.
Preoperative indications for surgery included benign disease in 51.1% vs. 40.9%, suspected malignancy in 18.9% vs. 26% and suspected follicular neoplasms including indeterminate/microfollicular cytology in 30% vs. 33.1% in the octogenarian patient group (≥80 yrs old) vs. the younger patient cohort (p=NS). Octogenarians had a 21.1% rate of significant malignancy on final pathology vs. 28.1% in the younger cohort (p=NS). The overall complication rate in the octogenarian group was 23.3% vs. 9.1% in the younger cohort (p=.0006). Male sex and lung disease were independent risk factors for perioperative complications. Complications unique to octogenarians included heart failure, atrial fibrillation, pneumonia, tracheotomy, urosepsis, blood transfusion, wound infection and ischemic colitis. There was no mortality in either group.
Patients ≥80 years of age can undergo successful thyroid surgery but with significantly higher morbidity. Earlier surgical intervention may be advised in those who are at high risk for disease progression whereas follow-up strategies without surgery may be advised for others.
PMCID: PMC3867691  PMID: 19744461
15.  BRAFV600E status adds incremental value to current risk classification systems in predicting papillary thyroid carcinoma recurrence 
Surgery  2012;152(6):984-990.
Papillary thyroid cancer (PTC) recurrence risk is difficult to predict. No current risk classification system incorporates BRAF mutational status. Here, we assess the incremental value of BRAF mutational status in predicting PTC recurrence relative to existing recurrence risk algorithms.
Serial data were collected for a historical cohort having undergone total thyroidectomy for PTC over a five-year period. Corresponding BRAFV600E testing was performed and Cox proportional hazard regression modeling, with and without BRAF status, was used to evaluate existing recurrence risk algorithms.
The five-year cumulative PTC recurrence incidence within our 356 patient cohort was 15%. 205 (81%) of associated archived specimens were successfully genotyped and 110 (54%) harbored the BRAFV600E mutation. The five-year cumulative recurrence incidence among BRAFV600E patients was 20%, versus 8% among BRAF wild type. BRAFV600E was significantly associated with time to recurrence when added to the following algorithms: AMES (HR 2.43 [1.08–5.49]), MACIS category (HR 2.46 [1.09–5.54]), AJCC-TNM (HR 2.51 [1.11, 5.66]), and ATA recurrence-risk category (HR 2.44 [1.08–5.50]), and model discrimination improved (incremental c-index range 0.046–0.109).
Addition of BRAF mutational status to established risk algorithms improves discrimination of recurrence risk in patients undergoing total thyroidectomy for PTC.
PMCID: PMC3502879  PMID: 23158172
Surgery  2012;152(6):1008-1015.
The durability of minimally invasive parathyroidectomy (MIP) has been questioned, and some advocate for routine open parathyroidectomy (OP). This study compared outcomes between patients treated with MIP versus OP for primary hyperparathyroidism (PHPT).
A retrospective review was performed to identify cases of PHPT with single adenomas (SA) between 2001 and 2011. Operations were classified as OP when both sides were explored. Kaplan-Meier estimates were plotted and compared by the log-rank test. P<0.05 was considered significant.
We analyzed 1,083 cases of PHPT with SA. 928 (85.7%) were MIP and 155 (14.3%) were OP. There was no difference in the rates of persistence (0.2% MIP vs. 0% OP, p = 0.61) or recurrence (2.5% MIP vs. 1.9% OP, p = 0.68) between the two groups. However, the Kaplan-Meier estimates began to separate beyond eight years follow-up. The OP group did experience a higher incidence of transient hypocalcemia postoperatively (1.9% vs. 0.1%, p = 0.01).
MIP appears equivalent to OP in single-gland disease. While patients undergoing OP experienced more transient hypocalcemia, patients undergoing MIP appear to have a higher long-term recurrence rate. Therefore, proper patient selection and counseling of these risks is necessary for either approach.
PMCID: PMC3501613  PMID: 23063313
18.  von Hippel-Lindau disease-associated solid microcystic serous adenomas masquerading as pancreatic neuroendocrine tumors 
Surgery  2012;152(6):1106-1117.
Patients with von Hippel-Lindau disease (VHL) commonly develop pancreatic cysts and neuroendocrine tumors (PNETs). Solid microcystic serous adenoma (SMSA), a rare tumor described in VHL patients, can be mistaken for PNET on imaging.
Clinical, pathologic and radiologic data were reviewed on VHL patients who underwent surgery for a pre-operative diagnosis of PNET since 1994 at one institution. Blinded to the pathological diagnoses, radiologists reassessed available imaging.
For 55 patients, 79 pancreatectomies were performed for presumed PNETs. Ten (18.2%) patients underwent 12 (15.2%) resections for tumors diagnosed as SMSA on final pathology. The average size of a SMSA leading to surgery was 3.6 ±0.4 cm. Four out of 11 SMSAs were still mistaken for PNETs when imaging was reassessed. Mean FDG-PET SUV was higher for 17 PNETs (12.1 ±1.2) compared to 6 SMSAs (4.2 ±0.5; p=0.002). The mean doubling time of SMSAs and PNETs was similar. Seven (15.2%) patients with pathologically-proven PNETs had malignant disease.
SMSAs can mimic PNETs on non-functional imaging; FDG-PET may help differentiate them. A high index of suspicion is needed to minimize operations performed for SMSA and to counsel VHL patients of their risks of undergoing surgery for a lesion with no known malignant potential.
PMCID: PMC3501588  PMID: 23107912
19.  Physician follow-up and observation of guidelines in the post treatment surveillance of colorectal cancer 
Surgery  2013;154(2):10.1016/j.surg.2013.04.013.
Guidelines for post resection surveillance of colorectal cancer recommend a collection of the patient's history and physical examination, testing for carcinoembryonic antigen (CEA), and colonoscopy. No consistent guidelines exist for the use of abdominal computed tomography (CT) and position emission tomography (PET)/PET-CT. The goal of our study was to describe current trends, the impact of oncologic follow-up on guideline adherence, and the patterns of use of nonrecommended tests.
We used Texas Cancer Registry—Medicare-linked data (2000-2009) to identify physician visits, CEA testing, colonoscopy, abdominal CT, and PET/PET-CT scans in patients ≥66 years old with stage I-III colorectal cancer who underwent curative resection. Compliance with guidelines was assessed with a composite measure of physician visits, CEA tests, and colonoscopy use from start of surveillance.
In patients who survived 3 years, the overall compliance with guidelines was 25.1%. In patients seen regularly by a medical oncologist, compliance with guidelines increased to 61.5% compared with 8.8% for those not seen by a medical oncologist regularly (P < .0001). The use of abdominal CTand PET/PET-CT increased from 57.5% and 9.5%, respectively, in 2001 to 65.8% and 24.6% (P <.0001) in 2006. Patients who saw a medical oncologist were more likely to get cross-sectionalimagingthan those whodid not (P <.0001).
Compliance with current minimum guidelines for post treatment surveillance of colorectal cancer is low and the use of nonrecommended testing has increased over time. Both compliance and use of nonrecommended tests are markedly increased in patients seen by a medical oncologist. The comparative effectiveness of CT and PET/PET-CT in the surveillance of colorectal cancer patients needs further examination.
PMCID: PMC3839939  PMID: 23889952
Surgery  2011;150(5):10.1016/j.surg.2011.04.002.
Intracranial hypertension frequently complicates severe traumatic brain injury (TBI) and may be associated with poor outcomes. TBI induces a neuroinflammatory response by microglial activation and upregulation of proinflammatory cytokines such as interleukin (IL)-1β, tumor necrosis factor alpha (TNF-α,) and interleukin-6 (IL-6). To elucidate the effect of elevated intracranial pressure on microglial function, we studied the effects of increased extracellular pressure on primary human microglial cell phagocytosis, proliferation, cytokine secretion and total nitrate production. In addition, since many patients receive propofol during anesthesia or intensive care unit sedation, we evaluated whether propofol alters the effects of pressure.
Human microglial cells (HMG030) were pretreated with (2.5–20μg/ml) propofol or intralipid as a vehicle control were incubated at ambient atmospheric pressure or at 15 or 30 mmHg increased pressure for 2 hours for phagocytosis assays or 24 hours for proliferation, cytokine secretion and total nitrate production studies. Phagocytosis was determined by incorporation of intracellular fluorescent latex beads. TNF-α, IL1-β and IL-6 were assayed by sandwich ELISA, and total nitrate by Greiss reagent.
Increased extracellular pressure stimulated phagocytosis vs. untreated microglial cells or cells treated with an intralipid vehicle control. In fact, propofol also stimulated microglial phagocytosis at ambient pressure. However, increased pressure reduced phagocytosis in the presence of propofol. Pressure also increased microglial TNF-α and IL-1β secretion and propofol pretreatment blocked the pressure-stimulated effect. However, IL-6 production was not altered either by pressure or propofol. Pressure also induced total nitrate secretion and propofol pretreatment decreased basal as well as pressure-induced microglial nitrate production.
Extracellular pressures consistent with increased intracranial pressure after head injury activate inflammatory signals in human primary microglial cells in vitro, stimulating phagocytosis, proliferation, and TNF-α, IL-1β, and total nitrate secretion but not affecting IL-6. Such inflammatory events may contribute to the worsened prognosis of traumatic brain injury after increased intracranial pressure. Since propofol alleviated these potentially pro-inflammatory effects, these results raise the possibility that the inflammatory cascade activated by intracranial pressure may be targeted by propofol in patients with increased intracranial pressure after TBI.
PMCID: PMC3837575  PMID: 21676422
traumatic brain injury; microglia; phagocytosis; proliferation; cytokines; extracellular pressure
Surgery  2012;152(5):879-885.
Cell migration is an integral component of intimal hyperplasia development and proteases are pivotal components in the process. Cell migration in response to urokinase is mediated through the aminoterminal domain (ATF) of the protein. This study examines the role of NAD(P)H oxidase during EGFR transactivation by ATF in human vascular smooth muscle cells (VSMC).
Human VSMCs were cultured in vitro. Linear wound and Boyden microchemotaxis assays of migration in response to ATF were performed in the presence and absence of NAD(P)H oxidase inhibitors (DPI and apocynin) and siRNA to Nox1. Additional assays were performed to examine the upstream pathways that lead to NAD(P)H oxidase activity. Assays were also performed for EGFR activation.
ATF produced concentration-dependent VSMC migration, which was inhibited by increasing concentrations of DPI and apocynin. ATF was shown to induce time-dependent EGFR phosphorylation, which peaked at 4-fold greater than control. This response was inhibited by DPI and apocynin in a concentration-dependent manner. ATF induced a concentration-dependent increase in intracellular oxygen free radical species, which was mitigated by the presence of DPI and apocynin. Inhibition of Gβγ by βARKCT reduced both NAD(P)H oxidase activity and EGFR activation. Inhibition of rac, which allows the NAD(P)H complex to assemble on the membrane, and inhibition of src, which induces assembly of the complex, both reduced ATF-dependent NAD(P)H oxidase activity and EGFR phosphorylation. siRNA to Nox1 prevented ATF-mediated EGFR activation and cell migration.
ATF requires NAD(P)H oxidase activity through a Gβγ, rac and src-mediated pathway to facilitate transactivation of EGFR and VSMC migration.
PMCID: PMC3419340  PMID: 22575880
uPA; growth factor domain; NAD(P)H Oxidase; migration; cell signaling; human coronary smooth muscle cell
22.  Distal pancreatectomy with splenic preservation revisited 
Surgery  2007;141(5):619-625.
Splenic preservation (SP) during distal pancreatectomy can be accomplished by ligating the main splenic artery and vein relying on blood supply from the short gastric vessels. The purpose of this study was to examine the short-term implications of this operation, comparing it to the outcomes following distal pancreatectomy with splenectomy.
The records of 259 patients who underwent distal pancreatectomy with and without SP at Massachusetts General Hospital from 1994 to 2004 were reviewed.
A total of 29% of patients underwent SP with this technique. These patients were more likely to be women (74% vs 56%, P = .008) and to have benign disease (93% vs 54%, P < .0001). Their operative times were shorter (2.5 vs 3.1 h, P < .0001), they had less blood loss (300 vs 500 ml, P < .0001) and a shorter duration of stay (6 days [interquartile range, 5 to 7] vs 7 days [interquartile range, 5 to 8], P = .001). SP was not a significant predictor of complications in either univariate (P = .445) or adjusted analysis (P = .543). One patient (1.4%) in the SP group was reoperated for splenic infarction and two patients (1.1%) in the splenectomy group for abscess and hemorrhage. There were 2 (0.8%) postoperative deaths, both in the splenectomy group.
Splenic preservation relying on blood supply from the short gastric vessels is reliable and safe and does not have a higher incidence of postoperative complications when compared to traditional distal pancreatectomy with splenectomy. The current series validates this approach and provides further evidence of its feasibility and safety.
PMCID: PMC3807103  PMID: 17462461
23.  Targeting the MAGE A3 antigen in pancreatic cancer 
Surgery  2012;152(3 0 1):S13-S18.
Pancreatic cancer is the fourth-leading cause of death in the United States and one of the most aggressive known malignancies. New and innovative advances in treatment are desperately needed. One promising area of investigational treatment for pancreatic cancer involves the use of immunotherapy. The development of immunotherapy for pancreatic cancer has been hampered by difficulty in generating tumor-reactive lymphocytes from resected specimens and by a lack of appropriate target antigens expressed on tumor cells. Innovative strategies have been developed with the use of peripheral blood lymphocytes that are genetically engineered to express T-cell receptors targeting common tumor antigens, including cancer-testis antigens, such as the MAGE-A3 antigen. Cancer-testis antigens pose excellent targets for immunotherapy because they are expressed in cancer and in the testis, an immune-privileged site, but have limited expression in normal tissue. An additional advantage in targeting cancer-testis antigens for immunotherapy is that their expression can be selectively up-regulated in tumor cells via epigenetic regulation with chromatin remodeling agents. Current interest in targeting cancer-testis antigens in pancreatic cancer is well-founded because cancer-testis antigens have been shown to be expressed in pancreatic cancer as potential targets for therapy. In our studies, we validated the expression pattern of cancer-testis antigens in resected specimens of pancreatic cancer and tested the hypothesis that treatment of pancreatic cancer cells with chromatin remodeling agents would render them more sensitive to antigen-specific T lymphocytes. We focused predominately on the MAGE-A3 antigen because it is highly expressed in pancreatic cancer, and several immunotherapeutic strategies are in clinical trials targeting this specific antigen. The results of these studies have important translational implications and provide the rationale for combined treatment with chromatin remodeling agents and immunotherapeutic approaches for pancreatic cancer.
PMCID: PMC3806055  PMID: 22770803
24.  Sonic Hedgehog in pancreatic cancer: From bench to bedside, then back to the bench 
Surgery  2012;152(3 0 1):S19-S32.
Developmental genes are known to regulate cell proliferation, migration, and differentiation; thus, it comes as no surprise that the misregulation of developmental genes plays an important role in the biology of human cancers. One such pathway that has received an increasing amount of attention for its function in carcinogenesis is the Hedgehog (Hh) pathway. Initially the domain of developmental biologists, the Hh pathway and one of its ligands, Sonic Hedgehog (Shh), have been shown to play an important role in body planning and organ development, particularly in the foregut endoderm. Their importance in human disease became known to cancer biologists when germline mutations that resulted in the unregulated activity of the Hh pathway were found to cause basal cell carcinoma and medulloblastoma. Since then, misexpression of the Hh pathway has been shown to play an important role in many other cancers, including those of the pancreas. In many institutions, investigators are targeting misexpression of the Hh pathway in clinical trials, but there is still much fundamental knowledge to be gained about this pathway that can shape its clinical utility. This review will outline the evolution of our understanding of this pathway as it relates to the pancreas, as well as how the Hh pathway came to be a high-priority target for treatment.
PMCID: PMC3806061  PMID: 22770959
25.  Pancreatic ductal adenocarcinoma: Long-term survival does not equal cure 
Surgery  2012;152(3 0 1):S43-S49.
Pancreatic ductal adenocarcinoma represents 90% of pancreatic cancers and is an important cause of cancer death in the United States. Operative resection remains as the only treatment providing prolonged survival, but even after a curative resection, 5-year survival rates are low. Our aim was to identify the prognostic factors for long-term survival after resection of pancreatic ductal adenocarcinoma related to patients, treatments, and tumor biology.
Retrospective review identified 959 patients who underwent resection of their pancreatic adenocarcinoma between February 1985 and December 2010, of whom 499 were resected before November 2006 and represent the cohort we describe in this study. Patient, tumor, and treatment-related variables were assessed for their associations with 5- and 10-year overall survival.
Of the 499 patients, 49% were female and median age was 65 years. The majority of patients had stage IIb disease (60%). Actual 5-year survival after resection of pancreatic adenocarcinoma was 19% (95/499), and actual 10-year survival was 10% (33/329). Significant clinicopathologic factors predicting 5- and 10-year survival were negative margins and negative nodal status. Interestingly, 41% (39/95) of long-term survivors had positive nodes and 24% (23/95) had positive margins.
Pancreatic ductal adenocarcinoma demonstrates a very heterogeneous biology, but patients with negative resection margins and node negative cancers are more likely to survive 5 years after resection. However, our series demonstrates that the biology of the cancer rather than simple pathologic factors determine a patient’s prognosis.
PMCID: PMC3806092  PMID: 22763261

Results 1-25 (272)