The memory trace of an intrusive trauma-analog episode

Intrusive memories are a core symptom of posttraumatic stress disorder. Compared with memories of everyday events, they are characterized by several seemingly contradictory features: intrusive memories contain distinct sensory and emotional details of the traumatic event and can be triggered by various perceptually similar cues, but they are poorly integrated into conceptual memory. Here, we conduct exploratory whole-brain analyses to investigate the neural representations of trauma-analog experiences and how they are reactivated during memory intrusions. We show that trauma-analog movies induce excessive processing and generalized representations in sensory areas but decreased blood-oxygen-level-dependent (BOLD) responses and highly distinct representations in conceptual/semantic areas. Intrusive memories activate generalized representations in sensory areas and reactivate memory traces specific to trauma-analog events in the anterior cingulate cortex. These findings provide the first evidence of how traumatic events could distort memory representations in the human brain, which may form the basis for future confirmatory research on the neural representations of traumatic experiences.

What is the real morbidity after emergency colectomy for Crohn's disease? A propensity score matched study

BACKGROUND

In the inflammatory bowel disease literature, emergency surgery for Crohn's disease (CD) is associated with worse postoperative outcomes as compared to elective surgery. Previous studies have compared heterogeneous groups only. We hypothesized that this association would be lost after matched analysis. We aimed to compare matched CD patients undergoing elective vs emergency surgery.

METHODS

The National Surgical Quality Improvement database (01/2005-12/2019) was utilized to identify adult CD surgical patients. Univariate and conditional logistic regression models were used to analyze unmatched and matched cohorts. Propensity-score matching was performed to match emergency to non-emergency patients 1:1. Our primary outcome was a composite of any complication. Our secondary endpoints were hospital readmission, unplanned reoperation and 30-day morbidity and mortality.

RESULTS

In the unmatched analyses (n = 12,181/95.28% elective and n = 603/4.72% emergency) of Crohn's patients undergoing colectomy, 20% of elective and 42% of emergency patients experienced a complication (p < 0.001). Over 20 outcomes measured including length of stay (LOS), readmission, infections and respiratory, cardiovascular and renal complications, were worse in the emergency cohort. In the matched analyses (n = 400 emergency/400 elective patients) only the categories of any complication (OR 1.44, 1.06-1.96 95% CI, p = 0.02), any surgical site infection (SSI, OR 1.53, 1.07-2.19 95% CI, p = 0.02), superficial SSI (OR 2.25, 1.14-4.44 95% CI, p = 0.02), organ space SSI (1.58 OR 1.04-2.4 95% CI, p = 0.03), unplanned intubation (OR 5.0, 1.45-17.27 95% CI, p = 0.01), ventilation > 48 h (OR 9.0, 1.4-38.79 95% CI, p = 0.003) and septic shock (OR 4.5, 1.86-10.9 95% CI, p < 0.001) were higher in the emergency cohort.

CONCLUSIONS

Matching CD patients resulted in a loss of the observed increase in cardiovascular and renal complications, reoperation and LOS following emergency surgery; however, SSIs and respiratory complications remained increased despite matching.

Mitochondrial DNA as a marker for treatment-response in post-traumatic stress disorder

Post-traumatic stress disorder (PTSD) is a serious mental health condition thought to be mediated by a dysregulated stress response system. Stress, especially chronic stress, affects mitochondrial activity and their efficiency in duplicating their genomes. Human cells contain numerous mitochondria that harbor multiple copies of their own genome, which consist of a mixture of wild type and variant mtDNA - a condition known as mitochondrial heteroplasmy. Number of mitochondrial genomes in a cell and the degree of heteroplasmy may serve as an indicator of mitochondrial allostatic load. Changes in mtDNA copy number and the proportion of variant mtDNA may be related to mental disorders and symptom severity, suggesting an involvement of mitochondrial dysfunction also in PTSD. Therefore, we examined number and composition of mitochondrial DNA before and after six weeks of inpatient psychotherapy treatment in a cohort of 60 female PTSD patients. We extracted DNA from isolated monocytes before and after inpatient treatment and quantified cellular mtDNA using multiplex qPCR. We hypothesized that treatment would lead to changes in cellular mtDNA levels and that change in mtDNA level would be associated with PTSD symptom severity and treatment response. It could be shown that mtDNA copy number and the ratio of variant mtDNA decreased during therapy, however, this change did not correlate with treatment response. Our results suggest that inpatient treatment can reduce signs of mitochondrial allostatic load, which could have beneficial effects on mental health. The quantification of mtDNA and the determination of cellular heteroplasmy could represent valuable biomarkers for the molecular characterization of mental disorders in the future.

Case-matched Comparison of Postoperative Outcomes Following Surgery for Inflammatory Bowel Disease After Exposure to Vedolizumab vs Other Biologics

BACKGROUND AND AIM

The effects of vedolizumab [VEDO] exposure on perioperative outcomes following surgery for inflammatory bowel disease [IBD] remain controversial. The aim of our study was to compare postoperative morbidity of IBD surgery following treatment with VEDO vs other biologics or no biologics.

METHODS

An institutional review board-approved, prospectively collected database was queried to identify all patients undergoing abdominal surgery for IBD between August 2012 and May 2017. The impact of VEDO within 12 weeks preoperatively on postoperative morbidity was initially assessed with univariate and multivariable analyses on all patients. A case-matched analysis was then carried out comparing patients exposed to VEDO vs other biologic agents, based on gender, age ± 5 years, diagnosis, date of surgery ± 2 years, and surgical procedure.

RESULTS

Out of 980 patients, 141 received VEDO. The majority of patients [59%] underwent surgery involving end or diverting ostomy creation. The initial multivariate analysis conducted on all patients indicated that VEDO use was independently associated with increased overall morbidity [p <0.001], but not infectious morbidity [p = 0.30]. However, the case-matched comparison of 95 VEDO-treated patients vs 95 patients treated with adalimumab or infliximab did not indicate any difference in overall morbidity [p = 0.32], infectious complications [p = 0.15], or surgical site infections [p = 0.12].

CONCLUSIONS

In a study population having a high rate of surgery involving ostomy creation, the exposure to preoperative VEDO was not associated with an increased morbidity rate when compared with other biologics.

The relationship between mesorectal grading and oncological outcome in rectal adenocarcinoma

AIM

The prognostic association between mesorectal grading and oncological outcome in patients undergoing resection for rectal adenocarcinoma is controversial. The aim of this retrospective chart review was to determine the individual impact of mesorectal grading on rectal cancer outcomes.

METHOD

We compared oncological outcomes in patients with complete, near-complete and incomplete mesorectum who underwent rectal excision with curative intent from 2009 to 2014 for Stage cI-III rectal adenocarcinoma. We also assessed the independent association of mesorectal grading and oncological outcome using multivariate models including other relevant variables.

RESULTS

Out of 505 patients (339 men, median age of 60 years), 347 (69%) underwent a restorative procedure. There were 452 (89.5%), 33 (6.5%) and 20 (4%) patients with a complete, near-complete and incomplete mesorectum, respectively. Local recurrence was seen in 2.4% (n = 12) patients after a mean follow-up of 3.1 ± 1.7 years. Unadjusted 3-year Kaplan-Meier analysis by mesorectal grade showed decreased rates of overall, disease-free and cancer-specific survival and increased rates of overall and distant recurrence with a near-complete mesorectum, while local recurrence was increased in cases of an incomplete mesorectum (all P < 0.05). On multivariate analyses, a near-complete mesorectum was independently associated with decreased cancer-specific survival (hazard ratio 0.26, 95% CI 0.1-0.7; P = 0.007). There were no associations between mesorectal grading and overall survival, disease-free survival, overall recurrence or distant recurrence (all P > 0.05).

CONCLUSION

Mesorectal grading is independently associated with oncological outcome. It provides unique information for optimizing surgical quality in rectal cancer.

Guidelines for Perioperative Care in Elective Colorectal Surgery: Enhanced Recovery After Surgery (ERAS®) Society Recommendations: 2018

BACKGROUND

This is the fourth updated Enhanced Recovery After Surgery (ERAS®) Society guideline presenting a consensus for optimal perioperative care in colorectal surgery and providing graded recommendations for each ERAS item within the ERAS® protocol.

METHODS

A wide database search on English literature publications was performed. Studies on each item within the protocol were selected with particular attention paid to meta-analyses, randomised controlled trials and large prospective cohorts and examined, reviewed and graded according to Grading of Recommendations, Assessment, Development and Evaluation (GRADE) system.

RESULTS

All recommendations on ERAS® protocol items are based on best available evidence; good-quality trials; meta-analyses of good-quality trials; or large cohort studies. The level of evidence for the use of each item is presented accordingly.

CONCLUSIONS

The evidence base and recommendation for items within the multimodal perioperative care pathway are presented by the ERAS® Society in this comprehensive consensus review.

A new approach to laser polishing and form correction of optical components

The increasing variety of optical components and materials, combined with stricter surface tolerance requirements, necessitate refining existing polishing processes and developing innovative new polishing solutions and metrology technologies. A fast, reproducible laser polishing process would offer considerable economic benefits over conventional mechanical polishing processes and interest a broad variety of optics manufacturers. In this work, a holistic approach is taken to address the various aspects of glass polishing and form correction via a novel laser polishing system design, the use of a measurement strategy that can be integrated inline and simulation results that are correlated with process parameter studies for different materials.

Control of stem cell response and bone growth on biomaterials by fully non-peptidic integrin selective ligands

Integrin selective peptidomimetics tune stem cell behavior in vitro and improve bone formation in rat calvarial defects.

Fluorescence imaging of invasive head and neck carcinoma cells with integrin αvβ6-targeting RGD-peptides: an approach to a fluorescence-assisted intraoperative cytological assessment of bony resection margins

We assessed the use of peptides containing arginylglycylaspartic acid (RGD) that target integrin αvβ6 as a potential approach for a fluorescence-assisted intraoperative cytological assessment of bony resection margins (F-AICAB) in patients who had bone-infiltrating squamous cell carcinoma (SCC) of the head and neck. This was assessed to demarcate invasive carcinoma cells that stained for αvβ6. Specimens from bony resection margins (n=362) were defined as either malignant or benign according to the results of cytological and histological examinations. Integrin αvβ6-targeting fluorescence-labelled RGD peptides were added to the cytological samples and the accuracy of the resulting signal assessed by comparing it with the cytological findings. The value of F-AICAB was evaluated to find out if it could help to improve future diagnoses, tests, and treatments. Integrin αvβ6 was strongly expressed in invasive SCC cells and qualified as a marker for bone-infiltrating carcinoma cells. It showed a high affinity to bind to invasive SCC cells and enabled swift and specific demarcation of αvβ6-stained carcinoma cells. It was also diagnostic, with a sensitivity of 100% (95% CI 81.3% to 99.3%), specificity of 98.3% (95% CI 94.4% to 99.0%), positive predictive value of 92% (95% CI 70.2% to 94.3%), and negative predictive value of 100% (95% CI 96.9% to 99.9%), compared with the cytological findings. The targeting of specific integrin subtypes with selective, synthetic ligands, adapted for multimodal imaging, is a promising new approach to diagnosis. Further studies are necessary to provide more evidence for successful clinical translation and to establish the impact on clinical procedures.

A randomized controlled study of intervention to improve continuity care engagement among HIV-infected persons after release from jails

Short-term stay, multiple jail admissions and social and financial difficulties are significant obstacles for continuity care engagement (CCE) after release among HIV-infected jail detainees. However, data existing on interventions or strategies to increase post-release CCE among this population are limited. We conducted a randomized controlled study among HIV-infected detainees at Cook County Jail during 2011-2014. The intervention group received telephone contact within 2-4 days of release by a continuity clinic coordinator, who scheduled and informed the ex-detainees of their appointment date within 6 weeks post-release plus standard of care, while the control group received standard of care. The standard of care included comprehensive discharge planning, offering substance abuse treatment and provision of information on how to self-schedule an appointment with the chosen clinics. Of the 166 detainees enrolled, 56 were excluded due to being sent to prison or re-incarcerated within 6 weeks. The final cohort included 55 detainees in each of the groups. The rate of CCE within 6 weeks after release was significantly higher in the intervention group compared to the control group (58% vs. 33%; P = .007). In multivariable logistic regression analysis, being in the control group was the only factor associated with no CCE within 6 weeks (adjusted odds ratio 2.66; 95% confidence interval 1.18-6.00; P = .02). The study findings suggest that the simple telephone contact intervention significantly improved CCE among HIV-infected jail detainees.

Synthesis and biological evaluation of a 99mTc-labelled cyclic RGD peptide for imaging the αvβ3 expression

Aim: The αvβ3 integrin is involved in tumour induced angiogenesis and tumour metastasis. We describe the synthesis and evaluation of a 99mTc-labelled RGD analogue for the visualisation of αvβ3 integrin expression. Methods: The linear peptides were assembled on a solid support. Cyclisation was performed under high dilution conditions. For conjugation with the chelator peptide, a water soluble carbodiimide was used. Radiolabelling was carried out due to standard procedures with high radiochemical yield and radiochemical purity. For in vivo evaluation, nude mice bearing αvβ3-positive human melanoma M21 and αv-negative human melanoma M21-L or Balb/c mice bearing αv-positive murine osteosarcoma were used. Results: Activity accumulation of 99mTc-DKCK-RGD 240 min p. i. was 1.1% ID/g in the αvβ3-positive melanoma and 0.3% ID/g in the negative control tumour. In the osteosarcoma model 2.2% ID/g was found 240 min p. i. Planar gamma camera images allowed contrasting visualisation of αvβ3-positive tumours 240 min p. i. Blocking of the tumour using the αvβ3-selective pentapeptide cyclo(-ArgGly-Asp-D-Phe-Val-) reduces activity accumulation in the tumour to background level. However, 240 min p. i. highest activity concentration was found in kidneys resulting in low tumour/kidney ratios. Metabolite analysis 240 min p. i. showed approximately 60% intact tracer in kidneys and 80% in the tumour. Only 24% intact tracer was found in blood 30 min p. i. Conclusion: 99mTc-DKCK-RGD allows imaging of αvβ3-positive tumours in mice. However, pharmacokinetics as well as metabolic stability of the tracer have to be improved for potential clinical application.

Restorative proctocolectomy: an example of how surgery evolves in response to paradigm shifts in care

AIM

Surgical technique constantly evolves in response to the pressure of progress. Ileal pouch anal anastomosis (IPAA) is a good example. We analysed the effect of changes in practice on the technique of IPAA and its outcomes.

METHOD

Patients undergoing primary IPAA at this institution were divided into three groups by date of the IPAA: those operated from 1983 to 1993, from 1994 to 2004 and from 2005 to 2015. Demographics, patient comorbidity, surgical techniques, postoperative outcomes, pouch function and quality of life were analysed.

RESULTS

In all, 4525 patients had a primary IPAA. With each decade, increasing numbers of surgeons were involved (decade I, 8; II, 16; III, 31), patients tended to be sicker (higher American Society of Anesthesiologists score) and three-staged pouches became more common. After an initial popularity of the S pouch, J pouches became dominant and a mucosectomy rate of 12% was standard. The laparoscopic technique blossomed in the last decade. 90-day postoperative morbidity by decade was 38.3% vs 50% vs 48% (P < 0.0001), but late morbidity decreased from 74.2% through 67.1% to 30% (P < 0.0001). Functional results improved, but quality of life scores did not. Pouch survival rate at 10 years was maintained (94% vs 95.2% vs 95.2%; P = 0.06).

CONCLUSION

IPAA is still evolving. Despite new generations of surgeons, a more accurate diagnosis, appropriate staging and the laparoscopic technique have made IPAA a safer, more effective and enduring operation.

Short-term outcomes of laparoscopic versus open total colectomy with ileorectal anastomosis: a case-matched analysis from a nationwide database

BACKGROUND

In the current study, we aimed to compare peri- and postoperative 30-day outcomes of patients undergoing laparoscopic versus open total colectomy with ileorectal anastomosis in a case-matched design using data procedure-targeted database.

METHODS

Patients who underwent elective total colectomy with ileorectal anastomosis in 2012 and 2013 were identified from the American College of Surgeons National Surgical Quality Improvement Program database. Patients were divided into two groups according to the type of surgical approach (laparoscopic and open). Laparoscopic and open groups were matched (1:1) based on age, gender, diagnosis, body mass index, and American Society of Anesthesiologists classification. Comorbidities, perioperative, and short-term (30-day) postoperative outcomes were compared between the matched groups.

RESULTS

We identified 1442 patients-549 in the laparoscopic group and 893 patients in the open group. After case matching, there were 326 patients in each group. There were 48 (14.7%) patients who had conversion in the laparoscopic group. The open group had a higher proportion of patients with ascites [0 (0%) vs. 7 (2.1%) p = 0.015], preoperative weight loss [26 (8.0%) vs. 45 (13.8%) p = 0.018], and contaminated wound classifications [Clean/Contaminated 261 (80%) vs. 240 (74%), Contaminated 55 (16.9%) vs. 54 (16.6%), and Dirty/Infected 8 (2.5%) vs. 28 (8.6%), (p = 0.003)]. The laparoscopic group had a significantly longer operative time (242 ± 98 vs. 202 ± 116 min, p < 0.001), shorter hospital stay (9.4 ± 8.5 vs. 13.3 ± 10.7 days, p < 0.001), and lower ileus rate (23.9 vs. 31.0%, p = 0.045) than the open group. After adjusting for covariates, the differences in terms of operative time and hospital stay remained significant [odds ratio (OR): 0.79, confidence interval (CI) 0.74-0.85 and OR 1.36, CI 1.21-1.52, p < 0.001, respectively].

CONCLUSIONS

Laparoscopic approach for total colectomy with ileorectal anastomosis is associated with a shorter hospital stay but longer operative time compared with an open approach.

What are the consequences of enlarging the extraction site to exteriorize a large specimen during laparoscopic surgery for Crohn's enteritis?

AIM

The implications of extraction site enlargement for the removal of large specimens during laparoscopic surgery for Crohn's disease have not been clearly described; such a description is the aim of this study.

METHOD

An institutional database was queried to identify patients undergoing laparoscopic resection for Crohn's disease through midline incision between 1995 and 2013. Perioperative outcomes were compared among cases completed through their initial extraction site (L), completed after increasing the length of the initial extraction site (IL) for specimen exteriorization, and cases converted to open surgery (C). Univariate and multivariate statistical analyses were performed.

RESULTS

Out of 309 patients, 52 required IL and 36 required C. Heavier, older, male patients were more likely to require IL or C. There were no differences in disease behaviour (P = 0.260), procedures performed (P = 0.12) or postoperative morbidity (P = 0.33). IL and L groups had a comparable initial length of hospital stay (LOS), which was shorter than in the C group. While there were no significant differences in causes of readmission (P = 0.31), IL had increased readmission rates compared with L [odds ratio (OR) 2.80, P = 0.021] or C (OR 13.89, P = 0.015). When combining initial and readmission LOS, C and IL groups had comparable overall LOS [median ratio (MR) 1.09, P = 0.57], which was significantly longer than in the L group (MR 1.27, P = 0.02).

CONCLUSION

Extraction site enlargement during laparoscopic surgery for enteric Crohn's disease had no impact on primary LOS. However, the shorter initial LOS was offset by increased readmission rates when compared with formal conversion. The threshold to convert in case of anticipated difficulty due to a large specimen should be low.

Tuning Mesenchymal Stem Cell Response onto Titanium-Niobium-Hafnium Alloy by Recombinant Fibronectin Fragments

Since metallic biomaterials used for bone replacement possess low bioactivity, the use of cell adhesive moieties is a common strategy to improve cellular response onto these surfaces. In recent years, the use of recombinant proteins has emerged as an alternative to native proteins and short peptides owing to the fact that they retain the biological potency of native proteins, while improving their stability. In the present study, we investigated the biological effect of two different recombinant fragments of fibronectin, spanning the 8-10th and 12-14th type III repeats, covalently attached to a new TiNbHf alloy using APTES silanization. The fragments were studied separately and mixed at different concentrations and compared to a linear RGD, a cyclic RGD and the full-length fibronectin protein. Cell culture studies using rat mesenchymal stem cells demonstrated that low to medium concentrations (30% and 50%) of type III 8-10th fragment mixed with type III 12-14th fragment stimulated cell spreading and proliferation compared to RGD peptides and the fragments separately. On the other hand, type III 12-14th fragment alone or mixed at low volume percentages ≤50% with type III 8-10th fragment increased alkaline phosphatase levels compared to the other molecules. These results are significant for the understanding of the role of fibronectin recombinant fragments in cell responses and thus to design bioactive coatings for biomedical applications.

Dissemination of Evidence From Systematic Reviews Through Academic CME Providers: A Feasibility Study

INTRODUCTION

Although systematic reviews represent a source of best evidence to support clinical decision-making, reviews are underutilized by clinicians. Barriers include lack of awareness, familiarity, and access. Efforts to promote utilization have focused on reaching practicing clinicians, leaving unexplored the roles of continuing medical education (CME) directors and faculty in promoting systematic review use. This study explored the feasibility of working with CME directors and faculty for that purpose.

METHODS

A convenience sample of five academic CME directors and faculty agreed to participate in a feasibility study exploring use in CME courses of systematic reviews from the Agency for Healthcare Research and Quality (AHRQ-SRs). AHRQ-SR topics addressed the comparative effectiveness of health care options. Participants received access to AHRQ-SR reports, associated summary products, and instructional resources. The feasibility study used mixed methods to assess 1) implementation of courses incorporating SR evidence, 2) identification of facilitators and barriers to integration, and 3) acceptability to CME directors, faculty, and learners.

RESULTS

Faculty implemented 14 CME courses of varying formats serving 1700 learners in urban, suburban, and rural settings. Facilitators included credibility, conciseness of messages, and availability of supporting materials; potential barriers included faculty unfamiliarity with SRs, challenges in maintaining review currency, and review scope. SR evidence and summary products proved acceptable to CME directors, course faculty, and learners by multiple measures.

DISCUSSION

This study demonstrates the feasibility of approaches to use AHRQ-SRs in CME courses/programming. Further research is needed to demonstrate generalizability to other types of CME providers and other systemic reviews.

Integrin α5β1 and p53 convergent pathways in the control of anti-apoptotic proteins PEA-15 and survivin in high-grade glioma

Integrin α5β1 expression is correlated with a worse prognosis in high-grade glioma. We previously unraveled a negative crosstalk between integrin α5β1 and p53 pathway, which was proposed to be part of the resistance of glioblastoma to chemotherapies. The restoration of p53 tumor-suppressor function is under intensive investigations for cancer therapy. However, p53-dependent apoptosis is not always achieved by p53-reactivating compounds such as Nutlin-3a, although full transcriptional activity of p53 could be obtained. Here we investigated whether integrin α5β1 functional inhibition or repression could sensitize glioma cells to Nutlin-3a-induced p53-dependent apoptosis. We discovered that α5β1 integrin-specific blocking antibodies or small RGD-like antagonists in association with Nutlin-3a triggered a caspase (Casp) 8/Casp 3-dependent strong apoptosis in glioma cells expressing a functional p53. We deciphered the molecular mechanisms involved and we showed the crucial role of two anti-apoptotic proteins, phosphoprotein enriched in astrocytes 15 (PEA-15) and survivin in glioma cell apoptotic outcome. PEA-15 is under α5β1 integrin/AKT (protein kinase B) control and survivin is a p53-repressed target. Moreover, interconnections between integrin and p53 pathways were revealed. Indeed PEA-15 repression by specific small-interfering RNA (siRNA)-activated p53 pathway to repress survivin and conversely survivin repression by specific siRNA decreased α5β1 integrin expression. This pro-apoptotic loop could be generalized to several glioma cell lines, whatever their p53 status, inasmuch PEA-15 and survivin protein levels were decreased. Our findings identify a novel mechanism whereby inhibition of α5β1 integrin and activation of p53 modulates two anti-apoptotic proteins crucially involved in the apoptotic answer of glioma cells. Importantly, our results suggest that high-grade glioma expressing high level of α5β1 integrin may benefit from associated therapies including integrin antagonists and repressors of survivin expression.

Steering matter wave superradiance with an ultranarrow-band optical cavity

A superfluid atomic gas is prepared inside an optical resonator with an ultranarrow bandwidth on the order of the single photon recoil energy. When a monochromatic off-resonant laser beam irradiates the atoms, above a critical intensity the cavity emits superradiant light pulses with a duration on the order of its photon storage time. The atoms are collectively scattered into coherent superpositions of discrete momentum states, which can be precisely controlled by adjusting the cavity resonance frequency. With appropriate pulse sequences the entire atomic sample can be collectively accelerated or decelerated by multiples of two recoil momenta. The instability boundary for the onset of matter wave superradiance is recorded and its main features are explained by a mean field model.

The rationale behind complete mesocolic excision (CME) and a central vascular ligation for colon cancer in open and laparoscopic surgery : proceedings of a consensus conference

BACKGROUND

It has been evident for a while that the result after resection for colon cancer may not have been optimal. Several years ago, this was showed by some leading surgeons in the USA but a concept of improving results was not consistently pursued. Later, surgeons in Europe and Japan have increasingly adopted the more radical principle of complete mesocolic excision (CME) as the optimal approach for colon cancer. The concept of CME is a similar philosophy to that of total mesorectal excision for rectal cancer and precise terminology and optimal surgery are key factors.

METHOD

There are three essential components to CME. The main component involves a dissection between the mesenteric plane and the parietal fascia and removal of the mesentery within a complete envelope of mesenteric fascia and visceral peritoneum that contains all lymph nodes draining the tumour area (Hohenberger et al., Colorectal Disease 11:354-365, 2009; West et al., J Clin Oncol 28:272-278, 2009). The second component is a central vascular tie to completely remove all lymph nodes in the central (vertical) direction. The third component is resection of an adequate length of bowel to remove involved pericolic lymph nodes in the longitudinal direction.

RESULT

The oncological rationale for CME and various technical aspects of the surgical management will be explored.

CONCLUSION

The consensus conference agreed that there are sound oncological hypotheses for a more radical approach than has been common up to now. However, this may not necessarily apply in early stages of the tumour stage. Laparoscopic resection appears to be equally well suited for resection as open surgery.

Renal Function Recovery and HIV Viral Suppression Following Tenofovir Discontinuation for Renal Impairment

BACKGROUND

Tenofovir associated nephrotoxicity (TDFN) is well recognized. This study describes the trend of renal function recovery and virologic consequences after cessation of tenofovir (TDF) for suspected TDFN.

METHODS

This was a retrospective chart review of 241 patients who underwent HLA-B*5701 allele testing between January 2007-December 2010. Demographics and clinical characteristics were compared at baseline, 3, 6, and 12 month between patients that continued and discontinued TDF. Factors associated with renal function recovery were assessed by multivariable logistic regression.

RESULTS

Eighty patients were identified with TDFN; 84% male, 74% African American (AA) with a median age of 55 years, and median length of TDF use for 122 weeks. Renal recovery at 12 months differed in those who stopped versus (vs.) continued TDF (83% vs. 57% p=0.03). In a crude analysis, baseline chronic kidney disease was negatively associated with renal recovery (p=0.01). An adjusted analysis showed that those who stopped TDF had 3.76 higher odds of renal recovery compared to those who did not stop TDF (95% CI: 1.26-11.27, p=0.02). There were no significant differences in virologic response after switching TDF to an alternative agent.

CONCLUSION

In this mostly AA male population with suspected TDFN, discontinuation of TDF was strongly associated with renal function recovery without affecting viral suppression.

Providers' lack of knowledge about herpes zoster in HIV-infected patients is among barriers to herpes zoster vaccination

Identification of perceptions about herpes zoster (HZ) disease, vaccine effectiveness and safety, and vaccine recommendations may impact immunization practices of physicians for HIV-infected patients. A survey was used to quantify knowledge of HZ as well as determine physician immunization perceptions and practices. There were 272/1700 respondents (16%). Correct answers for the incidence of varicella zoster virus (VZV) infection in adults and incidence of HZ in HIV-infected patients were recorded by 14% and 10% of providers, respectively. Providers reported poor knowledge of the incidence of disease recurrence in HIV-infected patients (41% correct), potency of HZ vaccine (47.5% correct) and mechanism of protection against reactivation of VZV (66% correct). Most (88%) agreed that HZ was a serious disease, and 73% believed that the burden of disease made vaccination important. A majority (75%) did not vaccinate HIV patients with HZ vaccine regardless of antiretroviral therapy status. Barriers to administration included safety concerns, concern that vaccine would not prevent HZ, risk of HZ dissemination, reimbursement issues and lack of Infectious Diseases Society of America (IDSA) guidelines. Only 38% of providers agreed that CDC guidelines were clear and 50% believed that clinical trials were needed prior to use of HZ vaccine in HIV-infected patients. Education about HZ is needed among HIV providers. Providers perceived vaccination as important, but data on vaccine safety and clear guidance from the CDC on this issue are lacking.

Early development of non-hodgkin lymphoma following initiation of newer class antiretroviral therapy among HIV-infected patients - implications for immune reconstitution

Background

In the HAART era, the incidence of HIV-associated non-Hodgkin lymphoma (NHL) is decreasing. We describe cases of NHL among patients with multi-class antiretroviral resistance diagnosed rapidly after initiating newer-class antiretrovirals, and examine the immunologic and virologic factors associated with potential IRIS-mediated NHL.

Methods

During December 2006 to January 2008, eligible HIV-infected patients from two affiliated clinics accessed Expanded Access Program antiretrovirals of raltegravir, etravirine, and/or maraviroc with optimized background. A NHL case was defined as a pathologically-confirmed tissue diagnosis in a patient without prior NHL developing symptoms after starting newer-class antiretrovirals. Mean change in CD4 and log₁₀ VL in NHL cases compared to controls was analyzed at week 12, a time point at which values were collected among all cases.

Results

Five cases occurred among 78 patients (mean incidence = 64.1/1000 patient-years). All cases received raltegravir and one received etravirine. Median symptom onset from newer-class antiretroviral initiation was 5 weeks. At baseline, the median CD4 and VL for NHL cases (n = 5) versus controls (n = 73) were 44 vs.117 cells/mm3 (p = 0.09) and 5.2 vs. 4.2 log₁₀ (p = 0.06), respectively. The mean increase in CD4 at week 12 in NHL cases compared to controls was 13 (n = 5) vs. 74 (n = 50)(p = 0.284). Mean VL log₁₀ reduction in NHL cases versus controls at week 12 was 2.79 (n = 5) vs. 1.94 (n = 50)(p = 0.045).

Conclusions

An unexpectedly high rate of NHL was detected among treatment-experienced patients achieving a high level of virologic response with newer-class antiretrovirals. We observed trends toward lower baseline CD4 and higher baseline VL in NHL cases, with a significantly greater decline in VL among cases by 12 weeks. HIV-related NHL can occur in the setting of immune reconstitution. Potential immunologic, virologic, and newer-class antiretroviral-specific factors associated with rapid development of NHL warrants further investigation.

Cell adhesion strength is controlled by intermolecular spacing of adhesion receptors

Spatial patterning of biochemical cues on the micro- and nanometer scale controls numerous cellular processes such as spreading, adhesion, migration, and proliferation. Using force microscopy we show that the lateral spacing of individual integrin receptor-ligand bonds determines the strength of cell adhesion. For spacings > or = 90 nm, focal contact formation was inhibited and the detachment forces as well as the stiffness of the cell body were significantly decreased compared to spacings < or = 50 nm. Analyzing cell detachment at the subcellular level revealed that rupture forces of focal contacts increase with loading rate as predicted by a theoretical model for adhesion clusters. Furthermore, we show that the weak link between the intra- and extracellular space is at the intracellular side of a focal contact. Our results show that cells can amplify small differences in adhesive cues to large differences in cell adhesion strength.

Force-induced destabilization of focal adhesions at defined integrin spacings on nanostructured surfaces

Focal adhesions are the anchoring points of cells to surfaces and are responsible for a large number of surface sensing processes. Nanopatterning studies have shown physiological changes in fibroblasts as a result of decreasing density of external binding ligands. The most striking of these changes is a decreased ability to form mature focal adhesions when lateral ligand distances exceed 76 nm. These changes are usually examined in the context of protein signaling and protein interactions. We show a physical explanation based on the balance between the forces acting on individual ligand connections and the reaction kinetics of those ligands. We propose three stability regimes for focal adhesions as a function of ligand spacing and applied stress: a stable regime, an unstable regime in which a large fraction of unbound protein causes adhesion disintegration, and a regime in which the applied force is too high to form an adhesion structure.

Soluble amyloid precursor proteins in the cerebrospinal fluid as novel potential biomarkers of Alzheimer's disease: a multicenter study

In this report, we present the results of a multicenter study to test analytic and diagnostic performance of soluble forms of amyloid precursor proteins alpha and beta (sAPP alpha and sAPP beta) in the cerebrospinal fluid (CSF) of patients with different forms of dementing conditions. CSF samples were collected from 188 patients with early dementia (mini-mental state examination >or=20 in majority of cases) and mild cognitive impairment (MCI) in 12 gerontopsychiatric centers, and the clinical diagnoses were supported by neurochemical dementia diagnostic (NDD) tools: CSF amyloid beta peptides, Tau and phospho-Tau. sAPP alpha and sAPP beta were measured with multiplexing method based on electrochemiluminescence. sAPP alpha and sAPP beta CSF concentrations correlated with each other with very high correlation ratio (R=0.96, P<0.001). We observed highly significantly increased sAPP alpha and sAPP beta CSF concentrations in patients with NDD characteristic for Alzheimer's disease (AD) compared to those with NDD negative results. sAPP alpha and sAPP beta highly significantly separated patients with AD, whose diagnosis was supported by NDD findings (sAPP alpha: cutoff, 117.4 ng ml(-1), sensitivity, 68%, specificity, 85%, P<0.001; sAPP beta: cutoff, 181.8 ng ml(-1), sensitivity, 75%, specificity, 85%, P<0.001), from the patients clinically assessed as having other dementias and supported by NDD untypical for AD. We conclude sAPP alpha and sAPP beta might be regarded as novel promising biomarkers supporting the clinical diagnosis of AD.

Amyloid beta peptides in plasma in early diagnosis of Alzheimer's disease: A multicenter study with multiplexing

We measured concentrations of Abeta peptides 1-42 and 1-40, and their ratio in plasma of patients carefully categorized clinically and neurochemically as having AD or other dementias with a newly commercially available multiplexing assay, characterized by reasonable laboratory performance (intra-assay imprecision in the range of 1.3-3.8% for Abeta1-42, and 1.8-4.1% for Abeta1-40, inter-assay imprecision for Abeta1-42, Abeta1-40, and Abeta1-42/Abeta1-40 concentration ratio in the range of 2.3-11.5%, 2.2-10.4% and 4.2-9.7%, respectively). Patients with AD or mild cognitive impairment of AD type (MCI-AD) whose clinical diagnosis was supported with CSF biomarkers (n=193) had significantly lower Abeta1-42 plasma concentrations (p<0.007), and Abeta1-42/1-40 ratios (p<0.003) compared to patients with other dementias and MCI of other types (n=64). No significant differences between persons with MCI of AD type and patients with early AD were observed, or between MCI of other types versus patients with early dementia of other types. Our findings reconfirm the hypothesis that alterations of biomarker concentrations occur early in a preclinical AD stage and that these alterations are also reflected in plasma.

Introduction of functional groups into peptides via N-alkylation

An optimized protocol for the mild and selective Fukuyama-Mitsunobu reaction was used for mono- and di- N-alkylation on solid support. Thereby, nonfunctionalized aliphatic and aromatic residues are quickly introduced into transiently protected, primary amines of a linear peptide. N-Alkylation can also be used to implement alkyl chains carrying (protected) functionalities suited for subsequent modification. Applicability of this method is demonstrated by various N-alkylated analogues of a cyclic CXCR4 receptor antagonist originally developed by Fujii et. al.

Efficient factor VIII affinity purification using a small synthetic ligand

BACKGROUND

Hemophilia A is currently treated by infusions of the coagulation factor (F) VIII, of which production and purification remain a challenging task. Current purification procedures using immunoaffinity chromatography are cumbersome, expensive, and suffer from the instability of the applied antibody ligands, which elute along with the product and contaminate it. Recently, FVIII was purified using octapeptide ligands, but their use is limited due to the low resistance to proteases.

OBJECTIVE

Our goal was to develop and evaluate a novel ligand for FVIII purification, overcoming the drawbacks of current procedures.

METHODS

Peptide ligands were screened for binding of (125)I-plasma-derived-FVIII (pdFVIII) in a microbead assay. A selected ligand-coated Toyopearl resin was then used for pdFVIII purification from cell-conditioned Delbucco's modified Eagle's medium (DMEM) containing fetal bovine serum. The proteolytic stability of ligand was measured by incubating with human serum and proteinase K, and its cytotoxicity towards human OV-MZ-6 cells was assayed.

RESULTS

A high-affinity octapeptidic FVIII ligand was modified into the small, highly stable and non-toxic peptidomimetic ligand L4 by rational and combinatorial design without affecting its affinity for FVIII. Using ligand L4-coated Toyopearl resin, pdFVIII was isolated from cell-conditioned medium with high purity and 89% column retention after elution with a mild buffer containing 0.6 m NaCl at pH 6.8.

CONCLUSIONS

Ligand L4 offers a valuable alternative to antibody-based procedures for laboratory and industrial production. Its synthesis by established solid-phase procedures is straightforward and considerably cheaper than the biotechnological production of antibodies, and safety concerns associated with the use of biological material are overcome.