Factors affecting risk of recurrence with periprosthetic infection in shoulder arthroplasty

BACKGROUND

The goal of treating periprosthetic infection, besides its eradication, is to avoid recurrence. The purpose of this study was to evaluate the impact of increasing Infection Severity (IS) score (based on the 2018 International Consensus Meeting on Orthopedic Infections statement), single-stage revision, and pathogenicity of the infective organism on the risk of infection recurrence.

METHODS

A database of 790 revisions performed by a single surgeon from 2004-2020 was reviewed for patients with minimum 2-year follow-up and ≥1 positive culture finding and/or pathology result from the revision surgical procedure. In total, 157 cases performed in 144 patients met the inclusion criteria. These cases were then categorized by infection probability (IS score) according to the 2018 consensus statement. Of 157 cases, 46 (29%) were classified as definitely or probably infected; 25 (16%), possibly infected; and 86 (55%), unlikely to be infected. Additionally, patients were grouped by single-stage surgery and pathogenicity of the infective organism.

RESULTS

A recurrence in this study was classified as the growth of the same organism in any patient requiring revision surgery. The 86 cases in the group with unlikely infection showed a recurrence rate of 2.3%. The 25 cases in the group with possible infection showed a recurrence rate of 12%. The 46 cases in the group with definite or probable infection showed a recurrence rate of 17.4%. Patients in the definite/probable infection group had a higher rate of recurrence than those in the groups with possible infection and unlikely infection (P = .009). The IS score was higher in the recurrence group than the non-recurrence group (7.5 ± 4.3 vs. 3.9 ± 3.4, P < .001). Overall, patients who underwent 1-stage revision had a 5.0% recurrence rate, but among the 34 patients with an infection classification of definite or probable who underwent 1-stage revision, the recurrence rate was 5.9%. Cases of highly virulent methicillin-resistant Staphylococcus aureus also showed a recurrence rate of 30.8% compared with 4.0% and 5.9% for Cutibacterium acnes and coagulase-negative staphylococci, respectively (P = .005).

CONCLUSION

Recurrent infection after treatment of a periprosthetic infection is associated with increasing severity scores, as defined in the 2018 consensus statement, and more aggressive microorganisms. However, a single-stage surgical procedure, even in patients with higher IS scores, did not impart a significantly increased risk of recurrence.

Glenoid-based reference system to differentiate shoulder pathologies on plain radiographs

BACKGROUND

Shoulder radiographs are used for evaluation and the planning of treatment of various pathologies. Making a diagnosis of these pathologies on plain radiographs occurs by recognizing the relationship of the humeral head on the registry of the glenoid. Quantification of these changes in registry does not currently exist. We hypothesize that a geometric relationship of the humeral head and the glenoid exists that is defined on an anteroposterior Grashey view radiograph by the relationship of the best-fit circle of the humeral head relative to the best-fit circle of the glenoid such that relative measurements will define the normal shoulder and the pathologic shoulder.

METHODS

One hundred fifty-six shoulders were included: 53 normal shoulders, 51 with primary glenohumeral osteoarthritis (GHOA), and 52 with cuff tear arthropathy (CTA). Humeral head best-fit circle was used to define the circle of the humeral head (cHH). A glenoid best-fit circle (cG) was defined by the following rules: (1) best fit of the glenoid articular surface and (2) was limited by the acromion such that either (a) it reaches maximal interaction with the inferior surface of the acromion or (b) the perimeter of the circle is at the lateralmost point of the acromion. The relationship between cHH and cG is defined by measurement of cHH in horizontal and vertical planes relative to the glenoid circle reference. The horizontal displacement angle (HDA) measures the horizontal position of cHH relative to cG, representing the degree of medialization toward the glenoid. The vertical displacement angle (VDA) measures the vertical position of cHH relative to cG, representing the degree of superiorization toward the acromion. Angles were compared by diagnosis and sex.

RESULTS

The mean HDA was 61.0° (95% confidence interval [CI] 60.3°-61.7°) in normal shoulders, 79.9° (95% CI 76.9°-82.9°) in GHOA, and 63.4° (95% CI 61.7°-65.1°) in CTA (P < .001). The mean VDA was 43.1° (95% CI 42.2°-44.0°) in normal shoulders, 40.9° (95% CI 39.9°-42.0°) in GHOA, and 59.7° (95% CI 57.6°-61.7°) in CTA (P < .001). Interobserver reliability was 0.991 (95% CI 0.94-1.0) and intraobserver reliability was 0.998 (95% CI 0.99-1.0). The geometric relationship of cHH to the glenoid circle reference was plotted for each group.

CONCLUSION

A geometric relationship exists of the humeral head in reference to the glenoid circle. Together, the HDA and the VDA distinguish between a normal shoulder and those with GHOA or CTA. This suggests that this novel methodology may provide a preoperative planning tool that is easily accessible.

Do preoperative scapular fractures affect long-term outcomes after reverse shoulder arthroplasty?

BACKGROUND

Postoperative scapular stress fractures (SSFs) are a formidable problem after reverse shoulder arthroplasty (RSA). Less is known about patients who have these fractures preoperatively. The primary aim of this study was to examine postoperative satisfaction in patients undergoing primary RSA who have preoperative SSF and compared to a matched cohort without preoperative fracture. The secondary aim was to examine the differences in patient-reported outcomes between and within study cohorts.

METHODS

A retrospective chart review of primary RSAs performed by a single surgeon from 2000 to 2020 was conducted. Patients diagnosed with cuff tear arthropathy (CTA), massive cuff tear (MCT), or rheumatoid arthritis (RA) were included. Five hundred twenty-five shoulders met inclusion criteria. Fractures identified on preoperative computed tomography scans were divided into 3 groups: (1) os acromiale, (2) multifragments (MFs), and (3) Levy types. Seventy-two shoulders had an occurrence of SSF. The remaining 453 shoulders were separated into a nonfractured cohort. American Shoulder and Elbow Surgeons Standardized Shoulder Assessment Form (ASES) and visual analog scale (VAS) scores were compared pre- and postoperatively in the total fracture group and the nonfractured group cohort. The multifragment subgroup was also compared to the pooled Os/Levy subgroup.

RESULTS

The total incidence of SSF in all shoulders was 13.7%. There was a difference in satisfaction scores at all time points between the nonfracture (7.9 ± 2.8) and total fracture group (5.4 ± 3.6, P < .001, at last visit). There was also a greater ASES total score in the nonfractured group vs the total fracture group at the final visit (69.4 ± 23.4 and 62.1 ± 24.2; P = .02). The MF group had worse ASES functional or VAS functional scores than the Os/Levy group at all time points: at 1 year, ASES function: MF 24.2 ± 14.5 and Os/Levy 30.7 ± 14.2 (P = .045); at 2 years, ASES function: MF 21.4 ± 14.4 and Os/Levy 35.5 ± 10.6 (P < .001); and at last follow-up, VAS function: MF 4.8 ± 2.8 and Os/Levy 6.4 ± 3.2 (P = .023).

DISCUSSION

Scapular fractures were proportionally most common in patients diagnosed with CTA (16.3%) compared with a 9.2% and 8.6% incidence in patients diagnosed with MCT and RA, respectively. Patients with preoperative SSF still see an improvement in ASES scores after RSA but do have lower satisfaction scores compared with the nonfractured cohort. The multifragment fracture group has lower functional and satisfaction scores at all postoperative time points compared with both the nonfracture and the Os/Levy fracture group.

Is ChatGPT a trusted source of information for total hip and knee arthroplasty patients?

Aims

While internet search engines have been the primary information source for patients' questions, artificial intelligence large language models like ChatGPT are trending towards becoming the new primary source. The purpose of this study was to determine if ChatGPT can answer patient questions about total hip (THA) and knee arthroplasty (TKA) with consistent accuracy, comprehensiveness, and easy readability.

Methods

We posed the 20 most Google-searched questions about THA and TKA, plus ten additional postoperative questions, to ChatGPT. Each question was asked twice to evaluate for consistency in quality. Following each response, we responded with, "Please explain so it is easier to understand," to evaluate ChatGPT's ability to reduce response reading grade level, measured as Flesch-Kincaid Grade Level (FKGL). Five resident physicians rated the 120 responses on 1 to 5 accuracy and comprehensiveness scales. Additionally, they answered a "yes" or "no" question regarding acceptability. Mean scores were calculated for each question, and responses were deemed acceptable if ≥ four raters answered "yes."

Results

The mean accuracy and comprehensiveness scores were 4.26 (95% confidence interval (CI) 4.19 to 4.33) and 3.79 (95% CI 3.69 to 3.89), respectively. Out of all the responses, 59.2% (71/120; 95% CI 50.0% to 67.7%) were acceptable. ChatGPT was consistent when asked the same question twice, giving no significant difference in accuracy (t = 0.821; p = 0.415), comprehensiveness (t = 1.387; p = 0.171), acceptability (χ2 = 1.832; p = 0.176), and FKGL (t = 0.264; p = 0.793). There was a significantly lower FKGL (t = 2.204; p = 0.029) for easier responses (11.14; 95% CI 10.57 to 11.71) than original responses (12.15; 95% CI 11.45 to 12.85).

Conclusion

ChatGPT answered THA and TKA patient questions with accuracy comparable to previous reports of websites, with adequate comprehensiveness, but with limited acceptability as the sole information source. ChatGPT has potential for answering patient questions about THA and TKA, but needs improvement.

Opioid analgesia in necrotizing pancreatitis: Incidence and timing of a hidden crisis

BACKGROUND

Rates of opioid usage during necrotizing pancreatitis (NP) disease course are unknown. We hypothesized that a significant number of NP patients were prescribed opioid analgesics chronically.

METHODS

Single institution IRB-approved retrospective study of 230 NP patients treated between 2015 and 2019.

RESULTS

Data were available for 198/230 (86%) patients. 166/198 (84%) were discharged from their index hospitalization with a prescription for an opioid. At the first clinic visit following hospitalization, 110/182 (60%) were using opioids. Six months after disease onset, 72/163 (44%) continued to require opioids. At disease resolution, 38/144 (26%) patients remained on opioid medications. The rate of active opioid prescriptions at six months after disease onset declined throughout the period studied from 68% in 2015 to 39% in 2019.

CONCLUSIONS

Opioid prescriptions are common in NP. Despite decline over time, 1 in 4 patients remain on opioids at disease resolution. These data identify an opportunity to adjust analgesic prescription practice in NP patients.

Necrotizing Pancreatitis from Hypertriglyceridemia: More Severe Disease?

BACKGROUND

Necrotizing pancreatitis (NP) is caused by hypertriglyceridemia (HTG) in up to 10% of patients. Clinical experience suggests that HTG-NP is associated with increased clinical severity; objective evidence is limited and has not been specifically studied in NP.

AIM

The aim of this study was to critically evaluate outcomes in HTG-NP. We hypothesized that patients with HTG-NP had significantly increased severity, morbidity, and mortality compared to patients with NP from other etiologies.

METHODS

A case-control study of all NP patients treated at a single institution between 2005 and 2018 was performed. Diagnostic criteria of HTG-NP included a serum triglyceride level > 1000 mg/dL and the absence of another specific pancreatitis etiology. To control for differences in age, sex, and comorbidities, non-HTG and HTG patients were matched at a 4:1 ratio using propensity scores. Outcomes were compared between non-HTG and HTG patients.

RESULTS

A total of 676 NP patients were treated during the study period. The incidence of HTG-NP was 5.8% (n = 39). The mean peak triglyceride level at diagnosis was 2923 mg/dL (SEM, 417 mg/dL). After propensity matching, no differences were found between non-HTG and HTG patients in CT severity index, degree of glandular necrosis, organ failure, infected necrosis, necrosis intervention, index admission LOS, readmission, total hospital LOS, or disease duration (P = NS). Mortality was similar in non-HTG-NP (7.1%) and HTG-NP (7.7%), P = 1.0.

CONCLUSION

In this large, single-institution series, necrotizing pancreatitis caused by hypertriglyceridemia had similar disease severity, morbidity, and mortality as necrotizing pancreatitis caused by other etiologies.

Novel Preoperative Patient-centered Surgical Wellness Program Impacts Length of Stay Following Pancreatectomy

BACKGROUND/AIM

We created a novel, preoperative wellness program (WP) that promotes recovery. This study assessed its impact on patient outcomes after pancreatectomy.

PATIENTS AND METHODS

Pancreatoduodenectomies (PD) and distal pancreatectomies (DP) performed from 2015 to 2018 were reviewed using our institutional NSQIP database. Patients in the WP had their medical conditions optimized and were provided with the following: chlorhexidine, topical mupirocin, incentive spirometer, and immune-nutrition supplements.

RESULTS

Out of a total of 669 pancreatectomy patients (411 PD, 258 DP), 308 were enrolled in the WP (188 PD, 120 DP). In the PD subgroup, on multivariable analysis (MVA), the WP patients had shorter lengths of hospital stay (LOS) (12 vs. 10 days, p<0.001). On MVA, WP patients had less post-op transfusion (20 vs. 10%, p=0.027). For the combined groups on MVA, LOS continued to be significant (OR=0.89, 95%CI=0.82-0.97, p<0.007).

CONCLUSION

A preoperative patient centered WP may reduce the length of stay.

Development and validation of an RP-HPLC DAD method for the simultaneous quantification of minor and major whey proteins

Whey represents a valuable protein source for human nutrition. Whey composition varies with respect to process characteristics during milk processing. For efficient exploitation of this dairy side stream, reliable analytical methods are essential. The aim of this study was to develop and validate an RP-HPLC-DAD method for the simultaneous quantification of the minor (lactoferrin, lactoperoxidase, bovine serum albumin) and major (α-lactalbumin, β-lactoglobulin) whey proteins. Seven RP-columns were compared and the composition of the mobile phase was optimized to achieve baseline separation. In validation experiments the limits of detection (LOD < 8 mg/L) and quantification (LOQ < 24 mg/L) were determined. Validity was proofed by precision (>96%), accuracy (95% - 103%) and recovery (96% - 102%) measurements. Peak homogeneity was confirmed by SDS-PAGE. The individual working ranges were adjusted to the estimated protein concentrations in whey, allowing direct analysis without sample preparation at a method runtime of 23 min.

Comparison of skin closure techniques in patients undergoing open pancreaticoduodenectomy: A single center experience

BACKGROUND

This study evaluated closure techniques and incisional surgical site complications (SSCs) and incisional surgical site infections (SSIs) after pancreaticoduodenectomy (PD).

METHODS

Retrospective review of open PDs from 2015 to 2018 was performed. Outcomes were compared among closure techniques (subcuticular + topical skin adhesive (TSA); staples; subcuticular only). SSCs were defined as abscess, cellulitis, seroma, or fat necrosis. SSIs were defined according to the National Surgical Quality Improvement Program (NSQIP).

RESULTS

Patients with subcuticular + TSA (n = 205) were less likely to develop an incisional SSC (9.8%) compared to staples (n = 139) (20.1%) and subcuticular (n = 74) (16.2%) on univariable analysis (P = 0.024). Multivariable analysis revealed no statistically significant difference in incisional SSC between subcuticular + TSA and subcuticular (P = 0.528); a significant difference remained between subcuticular + TSA and staples (P = 0.014). Unadjusted median length of stay (LOS) (days) was significantly longer for staples (9) vs. subcuticular (8) vs. subcuticular + TSA (7); P < 0.001. Incisional SSIs were evaluated separately according to the NSQIP definition. When comparing rates, the subcuticular + TSA group experienced lower incisional SSIs compared to the other two techniques (4.9% vs. 10.1%, 10.8%). However, this difference was not statistically significant by either univariable or multivariable analysis.

CONCLUSIONS

Subcuticular suture + TSA reduces the risk of incisional SSCs when compared to staples alone after pancreaticoduodenectomy.

Enzymatic generation of lactulose in sweet and acid whey: Optimization of feed composition and structural elucidation of 1-lactulose

Prebiotics are rising in interest in commercial scale productions due to increasing health awareness of consumers. Under bio-economic aspects, sweet and acid whey provide a suitable feed medium for the enzymatic generation of prebiotic lactulose. Since whey has a broad variation in composition, the influence of the feed composition on the concentration of generated lactulose was investigated. The influence of lactose and fructose concentration as well as enzymatic activity of two commercially available β-galactosidases were investigated. The results were evaluated via response surface analysis with a quadratic model containing pairwise interaction terms. The optimal feed composition yielding a theoretical maximal amount of lactulose was determined as 1.28 or 0.74 mol/kg fructose and 0.17 or 0.19 mol/kg lactose with an enzymatic activity of 2.0 or 2.8 μkat/kg for acid (pH 4.4) or sweet (pH 6.6) whey. Furthermore, the major reaction product was isolated and subsequently, the structural identity was elucidated and verified via extensive NMR analysis.

Is resident assistance equivalent to fellows during hepatectomy?

OBJECTIVE

Hepatectomy is a complex operative procedure frequently performed at academic institutions with trainee participation. The aim of this study was to determine the effect of assistant's training level on outcomes following hepatectomy.

METHODS

A retrospective review of a prospective, single-institution ACS-NSQIP database was performed for patients that underwent hepatectomy (2013-2016). Patients were divided by trainee assistant level: hepatopancreatobiliary (HPB) fellow versus general surgery resident (PGY 4-5). Demographic, perioperative, and 30-day outcome variables were compared using Chi-Square/Fisher's exact, Mann-Whitney U test, and multivariable regression. Cases involving a senior-level general surgery resident or HPB fellow as first assistant were included (n = 352). Those with a second attending, junior-level resident, or no documented assistant were excluded (n = 39).

RESULTS

Patients undergoing hepatectomy with an HPB fellow as primary assistant had more frequent preoperative biliary stenting, longer operative time, and more concomitant procedures including biliary reconstruction, resulting in a higher rate of post-hepatectomy liver failure (PHLF) (15% vs. 8%, P = 0.044). However, trainee level did not impact PHLF on multivariable analysis (OR 0.60, 95% CI [0.29-1.25], P = 0.173). Fellows assisted with proportionally more major hepatectomies (45% vs. 31%; P = 0.010) and resections for hepatobiliary cancers (31% vs. 19%, P = 0.014). On stratified analysis of major and minor hepatectomies, outcomes were similar between trainee groups.

CONCLUSION

Fellows performed higher complexity cases with longer operative time. Despite these differences, outcomes were similar regardless of assistant training level. Resident and HPB fellow participation in operations requiring liver resection provide comparable quality of care.

Clinical criteria for integrated molecular pathology in intraductal papillary mucinous neoplasm: less is more

BACKGROUND

For pancreatic cysts with negative cytology, Integrated Molecular Pathology (IMP) is a malignancy risk score integrating clinical criteria with pancreatic cyst fluid DNA profiling. Aside from main pancreatic duct (MPD) diameter, integrated clinical criteria are not International Consensus Guidelines High-Risk Stigmata. We predicted exclusion of clinical criteria except MPD diameter could simplify the IMP and better distinguish invasive/malignant disease.

METHODS

Records of >1100 patients with IPMN were reviewed retrospectively. Sensitivity, specificity, and accuracy of conventional IMP for invasive/malignant disease was compared to DNA profile including only MPD ≥10mm (IMP-10.) Invasive outcomes were invasive-IPMN/adenocarcinoma on surgical pathology, pathologic or radiographic evidence of invasive/metastatic disease during surveillance. Malignant outcomes included high grade dysplastic IPMN (HGD-IPMN).

RESULTS

225 patients who met study criteria underwent 283 IMP evaluations: 98 followed by surgery, 185 followed by ≥ 23 months surveillance. IMP-10 had greater specificity (90.1% vs. 73.7%) and accuracy (89.8% vs. 74.2%) for invasive disease compared to IMP in surgery + surveillance patients, but lower sensitivity (77.8% vs. 88.9%). Trends were similar in surgery patients alone and malignant outcome analyses.

CONCLUSION

IMP-10 excludes less-reliable clinical factors resulting in greater accuracy in predicting invasive/malignant disease and fewer patients with benign disease being recommended for surgery.

Does cyst growth predict malignancy in branch duct intraductal papillary mucinous neoplasms? Results of a large multicenter experience

BACKGROUND

Cyst growth of BD-IPMNs on follow-up imaging remains a concerning sign.

AIMS

To describe cyst size changes over time in BD-IPMNs, and determine whether cyst growth rate is associated with increased risk of malignancy.

METHODS

This is a retrospective study performed at two high volume tertiary centers. Mean cyst size at baseline (MCSB) and mean growth rate percentage (MGRP) were calculated. Rapid cyst growth was defined as MGRP ≥30%/year. Patient and cyst related characteristics were studied.

RESULTS

160 patients were followed for a median of 27.4 (12-114.5) months. MCSB was 15.1 ± 8.0 mm. During follow-up, 73 (45.6%) showed any cyst size increase, of which 15 cysts (9.4%) exhibited MGRP ≥30%/year. Rapid cyst growth was not associated with patient or cyst characteristics. Cyst fluid molecular analysis from 101 cysts showed KRAS mutation in 26. Compared to KRAS-negative cysts, neither MCSB (16.0 mm vs. 17.7 mm; p = 0.3) nor MGRP (3.9%/year vs. 5.8%/year; p = 0.7) was significantly different. Eighteen patients underwent surgery; 15 (83%) had LGD, and 3 had advanced neoplasia. Two cysts with LGD and one cyst with advanced neoplasia had MGRP ≥30%/year.

CONCLUSION

Increase in BD-IPMNs size was not associated with the known high risk patient or cyst-related characteristics. Rapid growth of BD-IPMNs was not associated with advanced neoplasia on surgical pathology.

Impact of Fellow Versus Resident Assistance on Outcomes Following Pancreatoduodenectomy

BACKGROUND

Participation by surgical trainees in complex procedures is key to their development as future practicing surgeons. The impact of surgical fellows versus general surgery resident assistance on outcomes in pancreatoduodenectomy (PD) has not been well studied. The purpose of this study was to determine differences in patient outcomes based on level of surgical trainee.

METHODS

Consecutive cases of PD (n = 254) were reviewed at a single high-volume institution over a 2-year period (July 2013-June 2015). Thirty-day outcomes were monitored through the American College of Surgeon's National Surgical Quality Improvement Program (NSQIP) and Quality In-Training Initiative. Patient outcomes were compared between PD assisted by general surgery residents versus hepatopancreatobiliary fellows.

RESULTS

The hepatopancreatobiliary surgery fellows and general surgery residents participated in 109 and 145 PDs, respectively. The incidence of each individual postoperative complication (renal, infectious, pancreatectomy-specific, and cardiopulmonary), total morbidity, mortality, and failure to rescue were the same between groups.

CONCLUSIONS

Patient operative outcomes were the same between fellow- and resident-assisted PD. These results suggest that hepatopancreatobiliary surgery fellows and general surgery residents should be offered the same opportunities to participate in complex general surgery procedures.

Management of Undifferentiated Solitary Mucinous Cystic Lesion of the Pancreas: A Clinical Dilemma

BACKGROUND

Management of solitary mucinous cystic lesions of the pancreas (MCLs) relies on correct differentiation between branch duct intraductal papillary mucinous neoplasm (BD-IPMN) and mucinous cystic neoplasm (MCN). Current international consensus guidelines recommend resection for MCN, and unifocal BD-IPMN can be followed in the absence of worrisome features/high-risk stigmata. We hypothesized that preoperative differentiation of solitary MCLs is suboptimal, and that all solitary MCLs should be treated similarly.

STUDY DESIGN

A retrospective review of an institutional database (2003 to 2016) identified 711 patients who underwent resection for pancreatic cyst. Only lesions that met cytologic or biochemical criteria for diagnosis of MCLs were included. Mucinous cystic neoplasms were defined by presence of ovarian stroma on pathology. Patients with formal preoperative diagnosis of BD-IPMN (multifocality, GNAS mutation) were excluded.

RESULTS

One hundred and eighty solitary MCLs were identified on preoperative imaging (mean age 54 years, 24% men). On surgical pathology, 108 were MCNs and 72 BD-IPMNs. There was no difference in invasive rate (7 of 108 [6.5%] MCNs vs 4 of 72 [5.6%] BD-IPMN; p ≈ 1). Pancreatic ductal connectivity was reported on imaging/endoscopy in 10 of 108 (9%) MCNs and 22 of 72 (31%) BD-IPMNs, representing 67% accuracy in differentiating MCNs from BD-IPMNs. On multivariate analysis, typical risk factors failed to predict invasiveness in either MCNs or BD-IPMNs. When all undifferentiated solitary MCLs were analyzed together, older age (p = 0.03) and cyst size (p = 0.04) were associated with increased invasive rate in multivariate analysis.

CONCLUSIONS

Unreliable differentiation and limited ability to predict invasiveness make solitary MCLs clinically challenging. With similar invasive rates, MCN and unifocal BD-IPMNs should be merged into one new entity for management, the undifferentiated solitary MCL.

Smoking and IPMN malignant progression

BACKGROUND

Patients with intraductal papillary mucinous neoplasm (IPMN) are at risk for invasive pancreatic cancer. We aim to characterize the impact of smoking on IPMN malignant progression.

METHODS

Patients undergoing pancreatic resection for IPMN (1991-2015) were retrospectively reviewed using a prospectively collected database.

RESULTS

Of 422 patients identified, 324 had complete data for analysis; 55% were smokers. Smoking status did not impact IPMN malignant progression (smokers/non-smokers: 22%/18% invasive grade; p = 0.5). Smokers were younger than non-smokers at the time of IPMN diagnosis (63 versus 68 years; p = 0.001). This association also held in the invasive IPMN subgroup (65 versus 72 years, p = 0.01). Despite this observation, rate of symptoms at diagnosis, cancer stage, and median survival were the same between smokers and non-smokers.

CONCLUSION

Although smoking is not associated with IPMN malignant progression, invasive IPMN is diagnosed at a younger age in smokers. These data suggest tobacco exposure may accelerate IPMN malignant progression.

Quantitative detection of human spermatogonia for optimization of spermatogonial stem cell culture

STUDY QUESTION

Can human spermatogonia be detected in long-term primary testicular cell cultures using validated, germ cell-specific markers of spermatogonia?

SUMMARY ANSWER

Germ cell-specific markers of spermatogonia/spermatogonial stem cells (SSCs) are detected in early (1-2 weeks) but not late (> 6 weeks) primary testicular cell cultures; somatic cell markers are detected in late primary testicular cell cultures.

WHAT IS KNOWN ALREADY

The development of conditions for human SSC culture is critically dependent on the ability to define cell types unequivocally and to quantify spermatogonia/SSCs. Growth by somatic cells presents a major challenge in the establishment of SSC cultures and therefore markers that define spermatogonia/SSCs, but are not also expressed by testicular somatic cells, are essential for accurate characterization of SSC cultures.

STUDY DESIGN, SIZE, DURATION

Testicular tissue from eight organ donors with normal spermatogenesis was used for assay validation and establishing primary testicular cell cultures.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Immunofluorescence analysis of normal human testicular tissue was used to validate antibodies (UTF1, SALL4, DAZL and VIM) and then the antibodies were used to demonstrate that primary testicular cells cultured in vitro for 1-2 weeks were composed of somatic cells and rare germ cells. Primary testicular cell cultures were further characterized by comparing to testicular somatic cell cultures using quantitative reverse transcriptase PCR (UTF1, FGFR3, ZBTB16, GPR125, DAZL, GATA4 and VIM) and flow cytometry (CD9 and SSEA4).

MAIN RESULTS AND THE ROLE OF CHANCE

UTF1, FGFR3, DAZL and ZBTB16 qRT-PCR and SSEA4 flow cytometry were validated for the sensitive, quantitative and specific detection of germ cells. In contrast, GPR125 mRNA and CD9 were found to be not specific to germ cells because they were also expressed in testicular somatic cell cultures. While the germ cell-specific markers were detected in early primary testicular cell cultures (1-2 weeks), their expression steadily declined over time in vitro. After 6 weeks in culture only somatic cells were detected.

LIMITATIONS, REASONS FOR CAUTION

Different groups attempting SSC culture have utilized different sources of human testes and minor differences in the preparation and maintenance of the testicular cell cultures. Differences in outcome may be explained by genetic background of the source tissue or technical differences.

WIDER IMPLICATIONS OF THE FINDINGS

The ability to propagate human SSCs in vitro is a prerequisite for proposed autologous transplantation therapy aimed at restoring fertility to men who have been treated for childhood cancer. By applying the assays validated here it will be possible to quantitatively compare human SSC culture conditions. The eventual development of conditions for long-term propagation of human SSCs in vitro will greatly facilitate learning about the basic biology of these cells and in turn the ability to use human SSCs in therapy.

STUDY FUNDING/COMPETING INTERESTS

The experiments presented in this manuscript were funded by a Project Development Team within the ICTSI NIH/NCRR Grant Number TR000006. The authors declare no competing interests.

TRIAL REGISTRATION NUMBER

Not applicable.

Alterations in cyst fluid genetics following endoscopic ultrasound-guided pancreatic cyst ablation with ethanol and paclitaxel

BACKGROUND AND STUDY AIMS

Endoscopic ultrasound (EUS)-guided ethanol lavage with paclitaxel injection has been shown to be effective for the treatment of pancreatic cystic neoplasms; however, the evidence for effectiveness is based primarily on cyst resolution on imaging. The aim of this study was to evaluate changes in pancreatic cyst fluid DNA following EUS-guided pancreatic cyst ablation (PCA) with ethanol and paclitaxel.

PATIENTS AND METHODS

In a single-center, prospective study, patients with suspected benign pancreatic cysts (15 - 50 mm in diameter; ≤ 5 compartments) underwent EUS-PCA with ethanol and paclitaxel followed 3 months later by repeat EUS-FNA, cyst aspiration for repeat DNA analysis, and possible repeat EUS-PCA. Abdominal imaging was repeated 3 - 4 months and 12 months after the second EUS. Changes in baseline pancreatic cyst fluid DNA, procedural complications, and radiographic changes in cyst volume were evaluated.

RESULTS

A total of 22 patients (median age 67 years; 15 women) with cysts in the head or uncinate (n = 10), body or neck (n = 8), and tail (n = 4), measuring a median diameter of 25 mm (range 15 - 43 mm), underwent one (n = 22) or two (n = 9) EUS-PCA procedures. Baseline cyst DNA included mutations in 11 patients (50 %). Postablation cyst fluid (n = 19) showed elimination of all baseline mutations in eight patients, new mutations in three, and no changes in eight without a baseline mutation. The largest per-protocol postablation image-defined volume change (n = 20) from either of the follow-up abdominal imaging studies (n = 20) demonstrated complete response ( < 5 % original volume) in 10 patients (50 %), partial response (5 % - 25 % original volume) in 5 (25 %), and a persistent cyst (> 25 % original volume) in 5 (25 %). During a median follow-up of 27 months (range 17 - 42 months), adverse events from all EUS-PCAs (n = 31) included abdominal pain alone in four patients (13 %), pancreatitis in three (10 %), peritonitis in one (3 %), and gastric wall cyst in one (3 %). The adverse events were classified as moderately severe in four patients (three with pancreatitis, one with peritonitis).

CONCLUSION

EUS-PCA with ethanol and paclitaxel may possibly eliminate mutant DNA in neoplastic pancreatic cysts. This technique leads to complete or partial image-defined resolution in 75 % of cysts but may lead to rare adverse events.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov (NCT01643460).

Nonoperative management of main pancreatic duct-involved intraductal papillary mucinous neoplasm might be indicated in select patients

BACKGROUND

Although the natural history of intraductal papillary mucinous neoplasm (IPMN) remains unclear, large surgical series have reported malignancy in 40% to 90% of main pancreatic duct (MPD)-involved IPMN. Accordingly, the 2012 International Consensus Guidelines recommend surgical resection in patients with suspected MPD involvement. We hypothesized that nonoperative management of select patients with suspected MPD-involved IPMN might be indicated.

STUDY DESIGN

From 1992 to 2012, 362 patients underwent surgical resection for pathologically confirmed IPMN at a single academic center. A retrospective review of prospectively collected data was performed. Main pancreatic duct involvement was suspected with an MPD diameter ≥5 mm on preoperative imaging. A multivariate analysis was conducted to assess predictors of malignancy.

RESULTS

Of 362 patients, 334 had complete data for analysis. Main pancreatic duct involvement was suspected preoperatively in 171 patients. Final pathology revealed 20% high-grade dysplastic and 27% invasive IPMN (47% malignant). Preoperative cytopathology and serum carbohydrate antigen 19-9 independently predicted malignancy (p = 0.003 and p = 0.002, respectively) and invasiveness (p < 0.0001 and p = 0.001, respectively). Patients with both negative preoperative cytopathology and normal serum carbohydrate antigen 19-9 (ie, double negatives) had a lower rate of malignancy and invasiveness (28% and 8% vs 58% and 38%; p < 0.0001). The MPD diameter did not predict malignancy or invasiveness (p = 0.36 and p = 0.46, respectively).

CONCLUSIONS

Patients with suspected MPD-involved IPMN have a highly variable rate of malignancy. Despite recent International Consensus Guidelines recommendations, these data suggest that MPD diameter is not an optimal gauge of malignant risk. Nonoperative management of suspected MPD-involved IPMN in select patients, particularly double negatives, might be indicated. Depending on age and comorbidity, operative risk might outweigh the risk of malignant progression in these patients.

What is the impact of hypogammaglobulinemia on the rate of infections and survival in solid organ transplantation? A meta-analysis

Hypogammaglobulinemia has been described after solid organ transplantation and has been associated with increased risk of infections. The aim of the study was to evaluate the rate of severe hypogammaglobulinemia and its relationship with the risk of infections during the first year posttransplantation. Eighteen studies (1756 patients) that evaluated hypogammaglobulinemia and posttransplant infections were included. The data were pooled using the DerSimonian and Laird random-effects model. Q statistic method was used to assess statistical heterogeneity. Within the first year posttransplantation, the rate of hypogammaglobulinemia (IgG < 700 mg/dL) was 45% (95% CI: 0.34-0.55; Q = 330.1, p < 0.0001), the rate of mild hypogammaglobulinemia (IgG = 400-700 mg/dL) was 39% (95% CI: 0.22-0.56; Q = 210.09, p < 0.0001) and the rate of severe hypogammaglobulinemia (IgG < 400 mg/dL) was 15% (95% CI: 0.08-0.22; Q = 50.15, p < 0.0001). The rate of hypogammaglobulinemia by allograft type: heart 49% (21%-78%; Q = 131.16, p < 0.0001); kidney 40% (30%-49%; Q = 24.55, p = 0.0002); liver 16% (0.001%-35%; Q = 14.31, p = 0.0002) and lung 63% (53%-74%; Q = 6.85, p = 0.08). The odds of respiratory infection (OR = 4.83; 95% CI: 1.66-14.05; p = 0.004; I(2) = 0%), CMV (OR = 2.40; 95% CI: 1.16-4.96; p = 0.02; I(2) = 26.66%), Aspergillus (OR = 8.19; 95% CI: 2.38-28.21; p = 0.0009; I(2) = 17.02%) and other fungal infections (OR = 3.69; 95% CI: 1.11-12.33; p = 0.03; I(2) = 0%) for patients with IgG < 400 mg/dL were higher than the odds for patients with IgG > 400 mg/dL. The odds for 1-year all-cause mortality for severe hypogammaglobulinemia group was 21.91 times higher than those for IgG > 400 mg/dL group (95% CI: 2.49-192.55; p = 0.005; I(2) = 0%). Severe hypogammaglobulinemia during the first year posttransplantation significantly increased the risk of CMV, fungal and respiratory infections, and was associated with higher 1-year all-cause mortality.

Pancreatic enucleation: improved outcomes compared to resection

INTRODUCTION

Pancreatic enucleation is associated with a low operative mortality and preserved pancreatic parenchyma. However, enucleation is an uncommon operation, and good comparative data with resection are lacking. Therefore, the aim of this analysis was to compare the outcomes of pancreatic enucleation and resection.

MATERIAL AND METHODS

From 1998 through 2010, 45 consecutive patients with small (mean, 2.3 cm) pancreatic lesions underwent enucleation. These patients were matched with 90 patients undergoing pancreatoduodenectomy (n = 38) or distal pancreatectomy (n = 52). Serious morbidity was defined in accordance with the American College of Surgeons-National Surgical Quality Improvement Program. Outcomes were compared with standard statistical analyses.

RESULTS

Operative time was shorter (183 vs. 271 min, p < 0.01), and operative blood loss was significantly lower (160 vs. 691 ml, p < 0.01) with enucleation. Fewer patients undergoing enucleation required monitoring in an intensive care unit (20% vs. 41%, p < 0.02). Serious morbidity was less common among patients who underwent enucleation compared to those who had a resection (13% vs. 29%, p = 0.05). Pancreatic endocrine (4% vs. 17%, p = 0.05) and exocrine (2% vs. 17%, p < 0.05) insufficiency were less common with enucleation. Ten-year survival was no different between enucleation and resection.

CONCLUSION

Compared to resection, pancreatic enucleation is associated with improved operative as well as short- and long-term postoperative outcomes. For small benign and premalignant pancreatic lesions, enucleation should be considered the procedure of choice when technically appropriate.

Diffusion-weighted imaging in characterization of cystic pancreatic lesions

AIM

To evaluate whether apparent diffusion coefficient (ADC) measurements from diffusion-weighted imaging (DWI) can characterize or predict the malignant potential of cystic pancreatic lesions.

MATERIALS AND METHODS

Retrospective review of the magnetic resonance imaging (MRI) database over a 2-year period revealed 136 patients with cystic pancreatic lesions. Patients with DWI studies and histological confirmation of cystic mass were included. In patients with known pancreatitis, lesions with amylase content of >1000 IU/l that resolved on subsequent scans were included as pseudocysts. ADC of cystic lesions was measured by two independent reviewers. These values were then compared to categorize these lesions as benign or malignant using conventional MRI sequences.

RESULTS

Seventy lesions were analysed: adenocarcinoma (n=4), intraductal papillary mucinous neoplasm (IPMN; n=28), mucinous cystic neoplasm (MCN; n=9), serous cystadenoma (n=16), and pseudocysts (n=13). There was no difference between ADC values of malignant and non-malignant lesions (p=0.06), between mucinous and serous tumours (p=0.12), or between IPMN and MCN (p=0.42). ADC values for low-grade IPMN were significantly higher than those for high-grade or invasive IPMN (p=0.03).

CONCLUSION

ADC values may be helpful in deciding the malignant potential of IPMN. However, they are not useful in differentiating malignant from benign lesions or for characterizing cystic pancreatic lesions.

Radiation dose from computed tomography in patients with necrotizing pancreatitis: how much is too much?

OBJECTIVES

Low-dose ionizing radiation from medical imaging has been indirectly linked with subsequent cancer. Computed tomography (CT) is the gold standard for defining pancreatic necrosis. The primary goal was to identify the frequency and effective radiation dose of CT imaging for patients with necrotizing pancreatitis.

METHODS

All patients with necrotizing pancreatitis (2003-2007) were retrospectively analyzed for CT-related radiation exposure.

RESULTS

Necrosis was identified in 18% (238/1290) of patients with acute pancreatitis (mean age = 53 years; hospital/ICU length of stay = 23/7 days; mortality = 9%). A median of five CTs/patient [interquartile range (IQR) = 4] were performed during a median 2.6-month interval. The average effective dose was 40 mSv per patient (equivalent to 2,000 chest X-rays; 13.2 years of background radiation; one out of 250 increased risk of fatal cancer). The actual effective dose was 63 mSv considering various scanner technologies. CTs were infrequently (20%) followed by direct intervention (199 interventional radiology, 118 operative, 12 endoscopic) (median = 1; IQR = 2). Magnetic resonance imaging did not have a CT-sparing effect. Mean direct hospital costs increased linearly with CT number (R = 0.7).

CONCLUSIONS

The effective radiation dose received by patients with necrotizing pancreatitis is significant. Management changes infrequently follow CT imaging. The ubiquitous use of CT in necrotizing pancreatitis raises substantial public health concerns and mandates a careful reassessment of its utility.

EUS-guided ethanol versus saline solution lavage for pancreatic cysts: a randomized, double-blind study

BACKGROUND

Surgery for pancreatic cysts is associated with significant morbidity. A pilot study previously demonstrated the safety of EUS-guided ethanol lavage of pancreatic cysts.

OBJECTIVE

To determine whether EUS-guided ethanol lavage would decrease pancreatic cyst size more than saline solution lavage.

DESIGN

Prospective, multicenter, randomized trial.

SETTING

Two tertiary referral hospitals in the United States.

PATIENTS

Patients referred for EUS with a 1- to 5-cm unilocular pancreatic cyst were randomized to blinded ethanol or saline solution lavage. Three months later, the cyst diameter was remeasured by EUS, and a second unblinded ethanol lavage was performed.

INTERVENTIONS

EUS-guided pancreatic cyst lavage.

MAIN OUTCOME MEASUREMENTS

Cyst ablation based on size changes from follow-up EUS, CT, and histology of resected specimens.

RESULTS

Of 58 patients randomized, 16 were excluded and 42 underwent initial ethanol (n = 25) or saline solution (n = 17) lavage. Ethanol lavage resulted in a greater mean percentage of decrease in cyst surface area (-42.9; 95% CI, -58.4 to -27.4) compared with saline solution alone (-11.4; 95% CI, -25.0 to 2.2; P = .009). Nineteen (76.0%) of 25 and 14 (82.3%) of 17 patients randomized to ethanol and saline solution, respectively, underwent a second ethanol lavage. A follow-up CT scan demonstrated resolution in 12 (33.3%) of 36 cysts. Histology of 4 resected cysts demonstrated epithelial ablation ranging from 0% (saline solution alone) to 50% to 100% (1 or 2 ethanol lavages). Complication rates were similar in all groups.

LIMITATION

Short-term follow-up.

CONCLUSIONS

EUS-guided ethanol lavage results in a greater decrease in pancreatic cyst size compared with saline solution lavage with a similar safety profile. Overall CT-defined complete pancreatic cyst ablation was 33.3%.

[A new locus for an autosomal dominant, non-syndromic hearing impairment (DFNA57) located on chromosome 19p13.2 and overlapping with DFNB15]

BACKGROUND

Non-syndromic hearing loss is the most genetically heterogeneous trait known in humans. To date, 54 loci for autosomal dominant non-syndromic sensorineural hearing loss (NSSHL) have been identified by linkage analysis.

METHODS

In this study a German pedigree has been identified segregating a progressive bilateral loss of lower and middle frequencies.

RESULTS

A genome-wide screening and linkage analysis revealed the existence of a new NSSHL locus (DFNA57). The phenotype was mapped to a 10 degrees Mbp interval on chromosome 19p13.2 from 7.8 to 18.2 degrees Mbp, a maximum 2-point LOD score of 3.08 was obtained for the marker D19S586. The region overlaps with the recessive locus DFNB15.

CONCLUSION

The results underline the heterogeneity of hereditary hearing disorders. Identification of genes can help to reach a better understanding of the molecular mechanism of hearing.

Cisplatininduzierte Hörstörungen bei Kindern in Abhängigkeit von der Pigmentierung der Iris

BACKGROUND

Cisplatin is commonly used as a chemotherapeutic agent in the treatment of solid tumors. Ototoxicity is an important side-effect. Melanin in the inner ear either plays an otoprotective role or has a negative influence on hearing. The concentration of cochlear melanin correlates with its concentration in the iris.

PATIENTS AND METHODS

We retrospectively examined 65 children (37 males, 28 females, average age 7.5 years) treated with cisplatin at the University Clinic of Muenster, Germany. We checked whether their eye color could be inferred from the prevalence and extent of cisplatin-induced hearing loss.

RESULTS

We found a hearing loss of >20 dB in 29 light-eyed and in 21 dark-eyed patients. Seven light-eyed and eight dark-eyed patients did not suffer from hearing impairment. Using the chi(2)-test on these four parameters, we found no significant connection between iris pigmentation and the prevalence or extent of hearing loss, although light-eyed children (80.6%) suffered more from hearing loss than dark-eyed children (72.4%). After the end of therapy with cisplatin, the prevalence of hearing loss was 83.3% in children up to 6 years and 71.4% in children older than 6 years. The average cumulative dose of cisplatin was 372 mg/m(2) of body surface in children with hearing loss, compared to 390 mg/m(2) in children without hearing loss.

CONCLUSION

We found no significant correlation between iris pigmentation (eye color) and hearing loss. Cisplatin-induced hearing loss occurs frequently and requires repeated monitoring.

Positron-emission tomography and computed tomography of cystic pancreatic masses

AIM

To investigate the sensitivity and specificity of computed tomography (CT), positron-emission tomography (PET), and both methods in combination, for determining whether cystic pancreatic tumours are malignant.

MATERIALS AND METHODS

We retrospectively identified all patients with cystic pancreatic tumours who underwent separate PET and contrast-enhanced CT examinations within a 1-month interval. Tumours were classified as benign or malignant on CT (two radiologists, independently), PET [a reported standardized uptake value (SUV) of 2.5 was taken as the cut-off between benign and malignant], and with PET and CT images together (two radiologists, in consensus). Readers were blinded to pathological and other radiological findings. Mean patient age and lesion size were compared between benign and malignant groups using Student's t-test. For CT findings, odds ratios (OR) and confidence intervals (CI) were calculated using multivariate logistic regression models. For CT, PET, and the combined images, sensitivities and specificities were calculated, and compared between groups using Fisher's exact test.

RESULTS

Thirty patients were identified. The best CT predictor of malignancy was size; mean diameter was 2.3 cm (benign) and 4.1 cm (malignant) (p<0.01); OR was 2.80 (95% CI, 1.26-6.20). Sensitivities of CT, PET and combined PET/CT images were 67-71, 57, and 86%, respectively. PET/CT was more sensitive than PET (p<0.01) or CT (p<0.01) alone. Specificities of CT, PET, and combined PET/CT images were 87-90, 65, and 91%, respectively. PET/CT was more specific than PET (p<0.01) but not CT (p>0.05).

CONCLUSION

The sensitivity and specificity of combined PET and CT images is comparable with or superior to either CT or PET alone in determining malignancy in cystic pancreatic lesions.

Degradation of organic matter from black shales and charcoal by the wood-rotting fungus Schizophyllum commune and release of DOC and heavy metals in the aqueous phase

We investigated the degradation of refractory organic matter (OM) by the basidiomycete fungus Schizophyllum commune to understand the release of dissolved organic compounds, heavy metals and sulfur. The investigated OM consisted of: charcoal, the short time end product of high temperature wood alteration in the absence of oxygen and composed mainly of pure OM; and black shales composed of clay minerals, quartz, sulfides and OM formed geogenically in an abiotic long-term process. In both cases, the OM fraction contains mainly polyaromatic hydrocarbons. We investigated the degradation of these fractions by a wood-rotting basidiomycete, which is able to produce exoenzymes like peroxidases and laccases. These enzymes can perform radical reactions to oxidize OM (like lignin) and therefore hypothetically are able to degrade OM from charcoal and/or low grade metamorphic black shales. Release of new components into dissolved organic carbon (DOC) could be detected in both cases. The attack on OM in the case of black shales coincided with the release of the heavy metals Fe, Mn and Ni. By following sulfur concentrations throughout the experiment, it was shown that heavy metal release is not due to pyrite oxidation. Ground black shale and charcoal samples were inoculated with S. commune in a diluted minimal medium containing aspartic acid and glucose. The aqueous and solid phases were sampled after 1, 7, 28 and 84 days. DOC was measured as non purgeable carbon and characterized by size exclusion chromatography and UV detection. Carbon concentrations of the solid phase were determined by element analyses. After initial decrease of the DOC concentrations due to the degradation of the carbon source provided with the medium, DOC increased up to 80 mg/l after 84 days. Carbon decreased in the solid fraction confirming that this carbon was released as DOC by the fungus. The newly generated DOC formed larger agglomerations than the DOC of the growth medium. The investigation proved that the degradation of persistent carbon sources, such as charcoal and black shale, is accelerated by fungal activity. Consequently, the associated release of heavy metals is also accelerated by the fungus. Main products of the biological degradation processes were organic heavy metal complexes which can enter the environment.

Proteomic Analysis of Neuroblastoma Subtypes in Response to Mitogen-Activated Protein Kinase Inhibition: Profiling Multiple Targets of Cancer Kinase Signaling

INTRODUCTION

Survival for high-risk neuroblastoma (NB) remains poor despite aggressive therapy. Novel therapies are vital for improving prognosis. We previously showed differential NB subtype sensitivity to p42/44 mitogen-activated protein kinase (ERK/MAPK) pathway inhibition. In this study, we investigated proteomic changes associated with resistance or sensitivity to MAPK kinase (MEK) inhibition in NB subtypes.

MATERIALS AND METHODS

SH-SY5Y (N-type), BE(2)-C (I-type), and SK-N-AS (S-type) were treated with MEK inhibitor U0126 (10 microM) for 1 and 24 h. Proteins were extracted from untreated and treated cells and analyzed for differential expression by two-dimensional polyacrylamide gel electrophoresis (2D-PAGE). Selected polypeptides were extracted from the gel and identified by liquid chromatography-linked tandem mass spectrometry (LC-MS/MS).

RESULTS

We identified 15 proteins that were decreased by 2.5-fold between untreated and 1 h treated cells and subsequently up-regulated 5-fold after 24 h drug treatment. N-type NB (MEK-resistant) showed the least altered proteomic profile whereas the I-type (MEK-sensitive) and S-type NB (MEK-intermediate) generated significant protein changes. The majority of proteins identified were induced by stress.

CONCLUSIONS

Protein differences exist between MEK inhibitor-treated NB subtypes. Identified polypeptides all have roles in mediating cellular stress. These data suggest that inhibition of the ERK/MAPK in NB subtypes leads to an intracellular stress response. The most resistant NB cell line to MEK inhibitor treatment generated the least protective protein profile, whereas the intermediate and most sensitive NB cells produced the most stress response. These findings suggest stress related protein expression may be targeted in assessing a response to ERK/MAPK therapeutics.

[Model oriented assessment of literacy performance in children with cochlear implants]

BACKGROUND

Although most hearing-impaired children lag behind normally hearing children in literacy acquisition, this aspect has hardly been addressed in the evaluation of language acquisition after cochlear implantation. The present study investigated written language abilities in 8 school-age children with cochlear implants. Neurolinguistic dual-route-models of written language processing indicate that literacy acquisition leads to the establishment of two distinct reading and writing strategies: a lexical one for the quick processing of known words and a sublexical one for decoding unfamiliar words or nonwords letter by letter.

PATIENTS

8 school-aged children were investigated, a very heterogeneous group concerning age of onset of hearing impairment, educational placement, and competences in sign language. However, this range is typical of the group of CI-children.

METHODS

The aim was to investigate if children with cochlear implants are able to establish both strategies or if they need to find a differential and individual access to written language. Performance within the Salzburger Lese-Rechtschreib-Test was evaluated. Individual performance of each subject was analysed.

RESULTS

Performance varied substantially ranging from only rudimentary spoken and written language abilities in two children to age-equivalent performance in three of them. Severe qualitative differences in written language processing were shown in the remaining three subjects. Suggestions for remediation were made and a re-test was carried out after 12 months. Their individual profiles of performance are described in detail.

CONCLUSIONS

The present study stresses the importance of a thorough investigation of written language performance in the evaluation of language acquisition after cochlear implantation. The results draw a very heterogeneous picture of performance. Model-oriented testing and analysis of performance prove to be sensible in at least a subpopulation of children with cochlear implants. Based on a better understanding of their acquired word-processing strategies, remediation programs meeting the needs of each individual child can be derived.

Pancreatic duct strictures are a common cause of recurrent pancreatitis after successful management of pancreatic necrosis

BACKGROUND

Successful surgical management of pancreatic necrosis can result in structural changes that cause recurrent pancreatitis. The purpose of this study is to review our clinical experience managing recurrent pancreatitis in patients after successful pancreatic debridement.

METHODS

We retrospectively reviewed 98 patients with pancreatic necrosis treated by debridement who made a complete recovery at our institution over an 8-year period (January 1995 to January 2003).

RESULTS

Fourteen patients (14%) developed recurrent pancreatitis 5 to 39 months (median, 15 months) after recovery. Five patients (36%) had pancreatic pseudocysts and 9 (64%) had radiologic evidence of obstructive pancreatitis. All patients had either a high-grade pancreatic duct stricture (N=7) or complete duct cutoff (N=7), localized to the pancreatic neck (N=10) or proximal pancreatic body (N=4) identified by either endoscopic retrograde cholangiopancreatography or magnetic resonance cholangiopancreatography. Two patients failed endoscopic stent therapy. All patients required re-operative treatment: 6 distal pancreatectomy, 6 pancreatico-jejunostomy Roux-en-Y, and 2 cystojejunostomy Roux-en-Y with no recurrence of pancreatitis after a median follow-up of 22 months.

CONCLUSIONS

Recurrent pancreatitis occurs in 14% of patients after successful pancreatic debridement. Pancreatic duct obstruction in the neck or proximal body is the primary etiologic factor. Re-operation directed at alleviating this ductal obstruction by resection or drainage is effective.

A randomized trial of the long-term effects of digital ocular compression in the late postoperative period

PURPOSE

To determine whether digital ocular compression is a viable technique to lower intraocular pressure in patients at least 3 months after trabeculectomy.

PATIENTS AND METHODS

A 6-month prospective, randomized, controlled, single-masked trial of 29 patients who underwent a trabeculectomy at the Glaucoma Service of Wills Eye Hospital. Patients were assigned to two groups: ocular compression or cheekbone compression (control group). The ocular compression group performed compression to the operated eye three times a day in the pattern of 10 seconds of pressure, 5 seconds of rest, and 10 seconds of pressure. Pressure was applied with the index finger through the closed lid to the center of the cornea. Pressure was steady and firm, but not painful. No massaging was performed. The cheekbone compression group applied pressure to the zygomatic arch with an identical style and frequency.

RESULTS

At 6 months, the change in mean intraocular pressure for the ocular compression group was 0.25 mm Hg compared with -0.44 mm Hg for the control group (P = 0.7). A few patients in both groups experienced large swings in intraocular pressure and mild to moderate discomfort.

CONCLUSION

Ocular compression had little to no success in the long-term management of increased intraocular pressure in the late postoperative period in this study.

Laparoscopic surgery for Crohn's disease: reasons for conversion

OBJECTIVE

To examine factors influencing conversion from a laparoscopic to an open procedure in patients requiring surgery for Crohn's disease.

SUMMARY BACKGROUND DATA

Laparoscopic management of patients with complications of Crohn's produces better outcomes than traditional open approaches, but it is difficult to determine before surgery who will be amenable to laparoscopic management. In this series, a laparoscopic approach was offered to virtually all patients to determine reasons for laparoscopic failure.

METHODS

Data regarding patients who underwent attempted laparoscopic procedures for Crohn's (January 1993 to June 2000) were collected prospectively. The bowel was mobilized laparoscopically and extracorporeal anastomoses were performed. Conversion to open surgery was defined as creation of an incision of more than 5 cm.

RESULTS

One hundred ten patients (age 37 +/- 1.1 years, 58% female) underwent 113 attempted laparoscopic interventions. Indications for surgery included obstruction (77%), failure of medical management (35%), fistula (27%), and perineal sepsis (4%). Sixty-eight procedures (60%) were completed laparoscopically. Procedures completed laparoscopically included ileocecectomy (n = 46), small bowel resection (n = 22), fecal diversion (n = 7), intestinal stricturoplasty (n = 7), resection of prior ileocolonic anastomosis (n = 5), segmental colectomy (n = 1), and lysis of adhesions (n = 1). Forty-five procedures (40%) were converted as a result of adhesions (n = 21), extent of inflammation or disease (n = 9), size of the inflammatory mass (n = 7), inability to dissect a fistula (n = 5), or inability to assess anatomy (n = 3). Factors associated with conversion were internal fistula as an indication for surgery, smoking, steroid administration, extracecal colonic disease, and preoperative malnutrition. In laparoscopic patients, mean times to passage of flatus and first bowel movement were 3.6 +/- 0.2 days and 4.4 +/- 0.2 days, respectively. Mean time to discharge was 6 +/- 0.2 days.

CONCLUSIONS

Attempted laparoscopic management is safe and effective if there is an appropriate threshold for conversion to an open procedure. Conversion factors identified in this study largely reflect technical challenge and severity of disease. Patients taking steroids and those with known fistulas or colonic involvement threaten laparoscopic failure, but many of these patients can be managed laparoscopically and have better outcomes. By understanding the reasons for conversion, it is hoped that the chances of laparoscopic success can be improved by modifying standard preoperative medical management or using additional technological capabilities (e.g., robotics).

Measuring the local burden of disease. A study of years of life lost in sub-Saharan Africa

BACKGROUND

An effective health policy necessitates a reliable characterization of the burden of disease (BOD) by cause. The Global Burden of Disease Study (GBDS) aims to deliver this information. For sub-Saharan Africa (SSA) in particular, the GBDS relies on extrapolations and expert guesses. Its results lack validation by locally measured epidemiological data.

METHODS

This study presents locally measured BOD data for a health district in Burkina Faso and compares them to the results of the GBDS for SSA. As BOD indicator, standard years of life lost (age-weighted YLL, discounted with a discount rate of 3%) are used as proposed by the GBDS. To investigate the influence of different age and time preference weights on our results, the BOD pattern is again estimated using, first, YLL with no discounting and no age-weighting, and, second, mortality figures.

RESULTS

Our data exhibit the same qualitative BOD pattern as the GBDS results regarding age and gender. We estimated that 53.9% of the BOD is carried by men, whereas the GBDS reported this share to be 53.2%. The ranking of diseases by BOD share, though, differs substantially. Malaria, diarrhoeal diseases and lower respiratory infections occupy the first three ranks in our study and in the GBDS, only differing in their respective order. Protein-energy malnutrition, bacterial meningitis and intestinal nematode infections occupy ranks 5, 6 and 7 in Nouna but ranks 15, 27 and 38 in the GBDS. The results are not sensitive to the different age and time preference weights used. Specifically, the choice of parameters matters less than the choice of indicator.

CONCLUSIONS

Local health policy should rather be based on local BOD measurement instead of relying on extrapolations that might not represent the true BOD structure by cause.

Circulation of core collection monographs in an academic medical library

Academic medical librarians responsible for monograph acquisition face a challenging task. From the plethora of medical monographs published each year, academic medical librarians must select those most useful to their patrons. Unfortunately, none of the selection tools available to medical librarians are specifically intended to assist academic librarians with medical monograph selection. The few short core collection lists that are available are intended for use in the small hospital or internal medicine department library. As these are the only selection tools available, however, many academic medical librarians spend considerable time reviewing these collection lists and place heavy emphasis on the acquisition of listed books. The study reported here was initiated to determine whether the circulation of listed books in an academic library justified the emphasis placed on the acquisition of these books. Circulation statistics for "listed" and "nonlisted" books in the hematology (WH) section of Indiana University School of Medicine's Ruth Lilly Medical Library were studied. The average circulation figures for listed books were nearly two times as high as the corresponding figures for the WH books in general. These data support the policies of those academic medical libraries that place a high priority on collection of listed books.

The outcome of the functioning filter after subsequent cataract extraction

OBJECTIVE

To evaluate and compare the outcome of functioning filtration surgery followed by cataract surgery with posterior intraocular lens implantation by both phacoemulsification and extracapsular cataract extraction (ECCE) techniques in glaucomatous eyes.

PATIENTS AND METHODS

We retrospectively evaluated the clinical course of 77 eyes (68 patients) that after successful trabeculectomy, underwent cataract surgery by either phacoemulsification or ECCE techniques. We determined the frequency of partial and absolute failure following cataract surgery by either phacoemulsification or ECCE in eyes with functioning trabeculectomies. Partial failure of intraocular pressure (IOP), control after cataract extraction was defined as the need for an increased number of antiglaucoma medications or argon laser trabeculoplasty to maintain IOP < or =21mm Hg. Complete failure of IOP control after cataract surgery was defined as an IOP >21 mm Hg on at least two consecutive measurements one or more weeks apart or the performance of additional filtration surgery. Failure rates were calculated using the Kaplan-Meier actuarial method. Failure rates between phacoemulsification and ECCE subgroups were compared using the log rank test.

RESULTS

The probability of partial failure by the third postoperative year after cataract surgery was 39.5% in the phacoemulsification subgroup and 37.3% in the ECCE subgroup. This small difference is not statistically significant (P = 0.48). The probability of complete failure by the fourth postoperative year after cataract surgery was 12.0% in the phacoemulsification subgroup and 12.5% in the ECCE subgroup. This difference is also not statistically significant (P = 0.77). At the 6-month follow-up visit, visual acuity of both groups improved one or more lines in 87.0% of patients, and worsened one or more lines in 3.9% of patients. Sixty-one percent achieved visual acuity of 20/40 or better. The most frequent complication was posterior capsular opacification requiring laser capsulotomy that occurred in 31.2% of patients.

CONCLUSION

Cataract extraction by either phacoemulsification or ECCE following trabeculectomy surgery may be associated with a partial loss of the previously functioning filter and the need for more antiglaucoma medications to control IOP.

Characterization of spontaneous metastasis in an aggressive breast carcinoma model using flow cytometry

Studies of metastasis can be accelerated and provide more mechanistic information using cell lines which reproducibly and aggressively metastasize, and which are accurately and easily detected in tissues at all stages of the metastatic process. Although reporter proteins such as green fluorescent protein (GFP) and beta-galactosidase have improved the tracking of tumor cells in vivo, their measurement has often been limited to visual observation and manual counting. In this study, we exploited the highly sensitive and objective quantitation provided by flow cytometry to characterize, in detail, the sequence of events associated with orthotopic metastasis in a highly aggressive mouse model. Following stable transfection of the MDA-MB-435 breast carcinoma cell line with GFP, we utilized an in vivo selection process to isolate a variant exhibiting increased primary tumor growth and metastasis. As few as one fluorescent tumor cell per 200,000 host cells could be accurately detected in dissociated tissues by flow cytometry, allowing us to demonstrate that metastatic cells migrate to the lungs of SCID mice very early after orthotopic implantation. Tumor burden in lungs increased in a smooth continuous manner, until death approximately eight weeks later. Levels of circulating tumor cells in blood were also detectable at an early timepoint, but remained relatively low throughout the course of secondary tumor development in the lungs. Surgical removal of the primary tumor at various times after inoculation significantly affected lung tumor burden, supporting the concept that circulating tumor cells in blood inefficiently initiate distal metastases. Furthermore, the continuing contribution to metastasis by the primary tumor was independent of tumor mass. The combined characteristics of enhanced orthotopic metastasis and quantitative detection in blood and tissues will make this a useful new model for the characterization of the multi-stage progression of cancer, and the preclinical evaluation of anti-neoplastic therapies.

The role of cAMP-MAPK signalling in the regulation of human hepatocellular carcinoma growth in vitro

OBJECTIVE

We have previously identified that primary human hepatocellular carcinoma (HCC) is associated with altered guanine nucleotide regulatory protein (G-protein) expression concomitant with decreased adenylyl cyclase (AC) and increased mitogen activated protein kinase (MAPK) activity in vivo. This study aims to address the potential link between Gs protein regulation of AC activity/ cyclic adenosine monophosphate (cAMP) production and the subsequent downstream regulation of MAPK activity and mitogenesis.

DESIGN

Pharmacological agents which selectively interact with specific target proteins involved in signal transduction via the Gs-AC-cAMP-MAPK signalling pathway were employed in cultured human HCC cell lines in these studies. These agents allow us to address the role of individual components of these pathways in the regulation of mitogenesis in HCC.

METHODS

These studies utilized three distinct human HCC cell lines (HepG2, Hep3B and SKHep) in the absence and presence of agents that alter AC-cAMP dependent signalling. De novo DNA synthesis was determined as a marker of altered cellular proliferation, and MAPK activity was determined as the ability to catalyse myelin basic protein (MBP) phosphorylation.

RESULTS

8-Bromo-cAMP (8-Br-cAMP; a cell-permeable cAMP analogue) and forskolin (AC activator) dose-dependently decreased thymidine incorporation in all three cell lines. In addition, serum-stimulated [3H] thymidine incorporation was significantly decreased in HepG2, Hep3B and SKHep cell lines following treatment with either 8-Br-cAMP or forskolin. By contrast, MDL12330A (MDL; irreversible AC inhibitor) enhanced thymidine incorporation in all three cell lines. Treatment with either 8-Br-cAMP or forskolin significantly decreased serum-stimulated MAPK activity.

CONCLUSIONS

These data suggest that cAMP acts as an anti-mitogenic agent in these hepatic tumorigenic cell lines in vitro such that inhibition of AC activity promotes MAPK activity and cellular mitogenesis in HCC.