A new method to detect apoptosis in paraffin sections: in situ end-labeling of fragmented DNA

Apoptosis (programmed cell death) can be difficult to detect in routine histological sections. Since extensive DNA fragmentation is an important characteristic of this process, visualization of DNA breaks could greatly facilitate the identification of apoptotic cells. We describe a new staining method for formalin-fixed, paraffin-embedded tissue sections that involves an in situ end-labeling (ISEL) procedure. After protease treatment to permeate the tissue sections, biotinylated nucleotides are in situ incorporated into DNA breaks by polymerase and subsequently stained with DAB via peroxidase-conjugated avidin. Staining of cells with the morphological characteristics of apoptosis was demonstrated in tissues known to exhibit programmed cell death, i.e., prostate and uterus after castration, tumors, lymph node follicles, and embryos. Apoptotic cells could be discriminated morphologically from areas of labeled necrotic cells, in which DNA degradation also occurs. Because apoptosis is relatively easily recognized in H&E-stained sections of involuting prostates of castrated rats, we used this model system to validate the ISEL method for the quantification of apoptotic cells. A high correlation was found between the fractions of ISEL-labeled cells and the fractions of apoptotic cells that were morphologically determined in adjacent sections. We conclude that ISEL is a useful technique for quantification of apoptosis in paraffin sections, especially for those tissues in which morphological determination is difficult. Furthermore, this new staining method enables the use of automated image cytometry for evaluating apoptosis.

BACE knockout mice are healthy despite lacking the primary beta-secretase activity in brain: implications for Alzheimer's disease therapeutics

Alzheimer's disease (AD) is a neurodegenerative disorder characterized by accumulation of amyloid plaques and neurofibrillary tangles in the brain. The major components of plaque, beta-amyloid peptides (Abetas), are produced from amyloid precursor protein (APP) by the activity of beta- and gamma-secretases. beta-secretase activity cleaves APP to define the N-terminus of the Abeta1-x peptides and, therefore, has been a long- sought therapeutic target for treatment of AD. The gene encoding a beta-secretase for beta-site APP cleaving enzyme (BACE) was identified recently. However, it was not known whether BACE was the primary beta-secretase in mammalian brain nor whether inhibition of beta-secretase might have effects in mammals that would preclude its utility as a therapeutic target. In the work described herein, we generated two lines of BACE knockout mice and characterized them for pathology, beta-secretase activity and Abeta production. These mice appeared to develop normally and showed no consistent phenotypic differences from their wild-type littermates, including overall normal tissue morphology and brain histochemistry, normal blood and urine chemistries, normal blood-cell composition, and no overt behavioral and neuromuscular effects. Brain and primary cortical cultures from BACE knockout mice showed no detectable beta-secretase activity, and primary cortical cultures from BACE knockout mice produced much less Abeta from APP. The findings that BACE is the primary beta-secretase activity in brain and that loss of beta-secretase activity produces no profound phenotypic defects with a concomitant reduction in beta-amyloid peptide clearly indicate that BACE is an excellent therapeutic target for treatment of AD.

Cytotoxicity of sulfonamide reactive metabolites: apoptosis and selective toxicity of CD8(+) cells by the hydroxylamine of sulfamethoxazole

Treatment with sulfonamide antibiotics in HIV-infected patients is associated with a high incidence (> 40%) of adverse drug events, including severe hypersensitivity reactions. Sulfonamide reactive metabolites have been implicated in the pathogenesis of these adverse reactions. Sulfamethoxazole hydroxylamine (SMX-HA) induces lymphocyte toxicity and suppression of proliferation in vitro; the mechanism(s) of these immunomodulatory effects remain unknown. We investigated the cytotoxicity of SMX-HA via apoptosis on human peripheral blood mononuclear cells and purified cell subpopulations in vitro. CD19(+), CD4(+), and CD8(+) cells were isolated from human peripheral blood by positive selection of cell surface molecules by magnetic bead separation. SMX-HA induced significant CD8(+) cell death (67 +/- 7%) at 100 microM SMX-HA, with only minimal CD4(+) cell death (8 +/- 4%). No significant subpopulation toxicity was shown when incubated with parent drug (SMX). Flow cytometry measuring phosphatidylserine externalization 24 h after treatment with 100 microM and 400 microM SMX-HA revealed 14.1 +/- 0.7% and 25. 6 +/- 4.2% annexin-positive cells, respectively, compared to 3.7 +/- 1.2% in control PBMCs treated with 400 microM SMX. Internucleosomal DNA fragmentation was observed in quiescent and stimulated PBMCs 48 h after incubation with SMX-HA. Our data show that CD8(+) cells are highly susceptible to the toxic effects of SMX-HA through enhanced cell death by apoptosis.

Rapid and sensitive detection of all types of MLL gene translocations with a single FISH probe set

The MLL gene on chromosome 11 band q23 is frequently involved in chromosome translocations in acute lymphoblastic leukemia and acute myeloid leukemia. The translocation results in the formation of a fusion gene on the derivative 11 chromosome consisting of the 5' part of the MLL gene and the 3' part of another gene; already more than 30 different partner chromosome regions have been described. MLL gene rearrangements are generally correlated with a poor prognosis. Therefore the presence of an 11q23 aberration has direct implications for treatment stratification, making early and rapid detection of utmost importance. In this study, we developed a FISH probe set for detection of MLL gene rearrangements according to strict design criteria. The cosmid probes are derived from the flanking regions of the MLL breakpoint region on chromosome 11 and when used in dual colored FISH experiments give rise to a split of the normally colocalizing (fused) signals in case of a translocation. This split signal was observed in seven out of 10 cases with an 11q23 translocation with various partner chromosomes. In the three other cases, a deletion of the 3' part of the MLL gene, downstream of the breakpoint region was also found. A low false positive value of only 1.7% was obtained for interphase cells in contrast to conventional dual colored FISH where the creation of a fusion signal has cut off values of at least 5-10%. A major advantage of our type of probe set is the application of a single FISH experiment to detect all types of MLL translocations. Moreover, since this cosmid probe set can be used for either interphase or metaphase studies, metaphases are no longer a prerequisite for detecting the presence of an 11q23 translocation. Nevertheless, metaphase FISH with the new probe set is helpful in determining the partner chromosome and therefore may lead to the identification of new partner genes.

Specific, selective, and complete staining of neurons of the myenteric plexus, using cuprolinic blue

Wholemounts consisting of both muscular layers of the rat's intestine have been stained with Cuprolinic blue and magnesium chloride. The procedure, which is specific for RNA, gives selective coloration of the somata of the neurons of the myenteric plexus. The neuronal nucleoli and Nissl substance are the only blue structures in such preparations. For descriptive and quantitative work, Cuprolinic blue is more selective than other cationic dyes, and it colors more neurons than can be shown by staining for mitochondrial NADH diaphorase. The absence of background color enables neurons to be identified more confidently and counted more quickly than is possible with other techniques, in which nuclei or mitochondria in smooth muscle and neuroglial cells are also stained. Numbers of myenteric neurons determined using the new method are higher than those obtained by other means.

Histological and immunopathological analysis of recovered encapsulated allogeneic islets from transplanted diabetic BB/W rats

Allogeneic islets encapsulated in an alginate/poly-L-lysine membrane and transplanted into diabetic BB/W rats resulted in graft failure within 2 weeks of transplantation. Graft failure was associated with a dense pericapsular infiltrate (PCI) that resulted in necrosis of the encapsulated islets. The PCI could be inhibited by immunosuppressive agents, including cyclosporine and dexamethasone, and this resulted in a significant increase in graft survival. Immunopathological characterization of the PCI indicated that there was a predominance of macrophages. T helper cells also appeared to be present in this PCI. Empty capsules were also found to induce a similar PCI that was identical in composition to that found around encapsulated islets. Thus alginate/poly-L-lysine capsules do not appear to be biocompatible and may account for the variable results in islet graft survival found with these capsules.

Immunoreactivity of proliferating cell nuclear antigen compared with bromodeoxyuridine incorporation in normal and neoplastic rat tissue

Monoclonal antibodies (MoAbs) against proliferating cell nuclear antigen (PCNA) represent a potentially useful tool for cell kinetic analysis of tumours. Because in paraffin-embedded tissue the relationship between PCNA immunoreactivity and tumour cell proliferation is not well characterized, we have compared PCNA positivity as detected by the PC10 MoAb with the bromodeoxyuridine labelling index (BrdUrd-LI) in two different transplantable hormone-dependent rat mammary tumours. Together, these two tumour models (MCR-83 and EMR-86) cover a wide range of S-phase fractions. Evaluating 31 methacarn-fixed tumours, a strong but non-linear relationship (r = 0.98) was obtained. PCNA-positive fractions were invariably higher than corresponding BrdUrd-LIs and also higher than the estimated growth faction: growth fractions as determined by continuous BrdUrd labelling of the tumour and stromal cell population in EMR-86 carcinomas were 12 and 26 per cent lower than PCNA-positive fractions, implying that a certain fraction of non-cycling cells can also express PCNA. A dramatic disturbance in the relationship of PCNA positivity and the BrdUrd-LI was observed in the EMR-86 model after growth arrest induced by hormonal ablation: PCNA immunoreactivity remained detectable for at least 3 days, whereas the BrdUrd-LI decreased almost immediately. In comparison, PCNA immunoreactivity persisted for a much shorter period in small intestinal cells that had stopped DNA replication when moving from the crypt towards the villus. It is concluded that although differences in PCNA expression exist between various tissues, PCNA as detected by the PC10 MoAb may be used in tumours as an operational marker for the growth fraction.(ABSTRACT TRUNCATED AT 250 WORDS)

AML1 fusion transcripts in t(3;21) positive leukemia: evidence of molecular heterogeneity and usage of splicing sites frequently involved in the generation of normal AML1 transcripts

The t(3;21)(q26;q22) is associated with chronic myelogenous leukemia in blast crisis (CML-BC), leukemia evolving from (therapy-related) myelodysplasia, and with leukemia following other hematopoietic proliferative diseases. Molecular cytogenetic analysis and cloning of a few t(3;21) cases indicate that the breakpoints are quite heterogeneous even within a specific clinical phenotype. Interestingly some of the (3;21) breakpoints involve the AML1 gene previously found rearranged in the t(8;21) associated with acute myelogenous leukemia. AML1 is related to the Drosophila gene runt and is the human counterpart of the gene for the alpha subunit of the nuclear polyoma enhancer binding protein (PEBP2) also known as the core binding factor (CBF). In the t(3;21) AML1 was found rearranged with EAP, a gene on chromosome 3 encoding a small ribosomal protein, as well as with EV11, another gene on chromosome 3. Here we report our study of six cases of t(3;21). By using fluorescence in situ hybridization (FISH) analysis and AML1 probes we could conclude that at least in two CML-BC cases the breakpoint occurred in the AML1 intron that is disrupted by the t(8;21). An AML1/EAP fusion transcript, different from the one described in a therapy-related myelodysplasia, was detected in both CML-BC cases. This transcript is expected to result in a predicted protein containing the AML1 nuclear binding domain with an attached stretch of 17 amino acids unrelated to the EAP small ribosomal protein. In the other t(3;21) patients we could not detect an AML1/EAP transcript or an AML1/EV11 transcript. This result suggests heterogeneity of the t(3;21) at the molecular level. The AML1 chimeric transcripts identified so far, both in the t(3;21) and in the t(8;21), diverge from the normal transcripts either after exon 5 or exon 6. Here we show that in normal AML1 transcripts different splicing events are seen to occur after AML1 exon 5 as well as exon 6.

Personalized Coaching Systems to support healthy behavior in people with chronic conditions

Chronic conditions cannot be cured but daily behavior has a major effect on the severity of secondary problems and quality of life. Changing behavior however requires intensive support in daily life, which is not feasible with a human coach. A new coaching approach - so-called Personal Coaching Systems (PCSs) - use on-body sensing, combined with smart reasoning and context-aware feedback to support users in developing and maintaining a healthier behavior. Three different PCSs will be used to illustrate the different aspects of this approach: (1) Treatment of neck/shoulder pain. EMG patterns of the Trapezius muscles are used to estimate their level of relaxation. Personal vibrotactile feedback is given, to create awareness and enable learning when muscles are insufficiently relaxed. (2) Promoting a healthy activity pattern. Using a 3D accelerometer to measure activity and a smartphone to provide feedback. Timing and content of the feedback are adapted real-time, using machine-learning techniques, to optimize adherence. (3) Management of stress during daily living. The level of stress is quantified using a personal model involving a combination of different sensor signals (EMG, ECG, skin conductance, respiration). Results show that Personal Coaching Systems are feasible and a promising and challenging way forward to coach people with chronic conditions.

ARM: axillary reverse mapping - the need for selection of patients

BACKGROUND

Axillary reverse mapping (ARM) is a technique that discerns axillary lymphatic drainage of the arm from the breast. This study was performed to evaluate both the feasibility of this technique and the proportion of metastatic involvement of ARM-nodes.

PATIENTS AND METHODS

Patients with invasive breast cancer and an indication for axillary lymph node dissection (ALND) were enrolled in the study: patients with a tumor-positive sentinel lymph node (SLN(+)-group) and patients who had axillary metastases proven by preoperative cytology (CP-N(+)-group) were distinguished. ARM was performed in all patients by injecting blue dye. During surgery ARM-nodes were identified and removed first, followed by ALND.

RESULTS

Between October 2009 and June 2011 93 patients underwent ARM. There were 43 patients in the SLN(+)-group and 50 patients in the CP-N(+)-group. No significant differences in visualization rate of ARM-nodes between the groups (86 vs 94% respectively, P = 0.196) were identified. In the SLN(+)-group none of the ARM-nodes contained metastases versus 11 patients (22%) in the CP-N(+)-group (P = 0.001). Patients receiving neoadjuvant systemic therapy had a significantly lower risk of additional axillary lymph node metastases (24.6 vs 44.4%, P = 0.046).

DISCUSSION

The ARM procedure is technically feasible with a high visualization rate. The proportion of patients with metastases in the ARM-nodes was significantly higher in patients with proven axillary metastases than in patients with a positive SLN. Patients with SLN metastases appear to be good candidates for the ARM technique and possibly also patients with proven axillary metastases receiving neoadjuvant chemotherapy.

Multicentre randomized clinical trial of the effect of chewing gum after abdominal surgery

Background

Postoperative ileus is a common complication of abdominal surgery, leading to patient discomfort, morbidity and prolonged postoperative length of hospital stay (LOS). Previous studies suggested that chewing gum stimulates bowel function after abdominal surgery, but were underpowered to evaluate its effect on LOS and did not include enhanced recovery after surgery (ERAS)-based perioperative care. This study evaluated whether chewing gum after elective abdominal surgery reduces LOS and time to bowel recovery in the setting of ERAS-based perioperative care.

Methods

A multicentre RCT was performed of patients over 18 years of age undergoing abdominal surgery in 12 hospitals. Standard postoperative care (control group) was compared with chewing gum three times a day for 30 min in addition to standard postoperative care. Randomization was computer-generated; allocation was concealed. The primary outcome was postoperative LOS. Secondary outcomes were time to bowel recovery and 30-day complications.

Results

Between 2011 to 2015, 1000 patients were assigned to chewing gum and 1000 to the control arm. Median LOS did not differ: 7 days in both arms (P = 0·364). Neither was any difference found in time to flatus (24 h in control group versus 23 h with chewing gum; P = 0·873) or time to defaecation (60 versus 52 h respectively; P = 0·562). The rate of 30-day complications was not significantly different either.

Conclusion

The addition of chewing gum to an ERAS postoperative care pathway after elective abdominal surgery does not reduce the LOS, time to bowel recovery or the rate of postoperative complications. Registration number: NTR2594 (Netherlands Trial Register).

Interphase cytogenetics of the t(8;21)(q22;q22) associated with acute myelogenous leukemia by two-color fluorescence in situ hybridization

In the translocation (8;21)(q22;q22) associated with acute myelogenous leukemia (AML), part of the long arm of chromosome 8 is reciprocally translocated onto chromosome 21. At the molecular level the translocation results in the fusion of the 5' region of the AML1 gene on chromosome 21 and almost the entire CDR gene (also ETO or MTG8) on chromosome 8. The translocation can be demonstrated by techniques such as Southern blot analysis of DNA and reverse transcription-polymerase chain reaction (RT-PCR) analysis of mRNA. Neither of these methods demonstrates the translocation in individual cells. To detect the translocation at the single cell level, we used two probes, a cosmid clone containing the first five exons of AML1 and a P1 clone containing the entire CDR gene. Hybridization of the two probes to the distal and proximal side of the translocation breakpoint on chromosome 8 was expected to highlight the 8q-derivative in an interphase cell. To demonstrate the ability to identify the translocation in interphase cells using two-color FISH, these two probes were hybridized simultaneously to the Kasumi-1 cell line containing the 8;21 translocation and to t(8;21)-positive leukemic cells from a patient. Each probe was detected with a different color so that their relationship in the sample could be determined within the same interphase cell. Simultaneous hybridization of the CDR and AML1 probes to interphase cells resulted in one red and one green hybridization signal randomly located in the cell, from the hybridization to the normal chromosomes (8, 21), and one red-green pair of signals from the close hybridization of the two probes to the fusion gene on the derivative 8q-chromosome, indicating the translocation. This technique may be a useful complement for the analysis of the t(8;21), since critical information can be obtained from samples not suited for RT-PCR and conventional cytogenetic techniques. In addition, it may be useful for the assessment of minimal residual disease where RT-PCR is of limited value.

The incidence and significance of micrometastases in lymph nodes of patients with ductal carcinoma in situ and T1a carcinoma of the breast

AIM

To report the incidence and predictive value of positive axillary nodes in ductal carcinoma in situ (DCIS) and T1a carcinoma of the breast.

METHODS

Cases from The Netherlands Cancer Institute were used to determine the incidence of lymph-node metastases. All consecutive patients with primary breast cancer that were treated between 1989 and 1998 and who had undergone axillary dissection were selected. Patients were identified with pure DCIS (n = 71), DCIS with small invasion (n = 12), invasive ductal/lobular carcinoma (IDC/ILC) < or =5 mm (n = 18) or tubular carcinoma < or =10 mm (n = 17). All archived lymph nodes of these patients were re-evaluated using immunohistochemistry (IHC).

RESULTS

In DCIS the incidence increased from 1.4% with routine staining to 11% with IHC. For DCIS with small invasion it was 0 vs 27%, respectively. In IDC/ILC sized 2-5 mm the incidence rose from 6 to 12% and in tubular carcinoma < or =10 mm from 0 to 12%. All but one of the immunohistochemically detected metastases were isolated tumour cells (n = 9) or small (micro)metastases (n = 4). Maximally two nodes per patient were affected. None of the patients with positive lymph nodes died during follow-up (mean 102 months).

CONCLUSIONS

Survival of our patients appeared not to be influenced by the finding of micrometastases in the lymph nodes by IHC. Immunohistochemistry of the sentinel node seems not contributive to further treatment in these patients.

Graft-versus-host disease associated with intestinal transplantation in the rat. Host immune function and general histology

Graft-versus-host disease was studied on the 10th and 14th postoperative days in Lewis x Brown Norway F1 rats (LBN-F1) receiving Lewis accessory heterotopic intestinal allografts. LBN-F1 isograft recipients and LBN-F1 rats were used as controls. The rats were injected with sheep erythrocytes five days before sacrifice. Rats with graft-versus-host disease had progressive loss of the normal architecture of the lymphoid organs. Skin, liver, colon, and salivary glands were infiltrated with immunoblasts and had patchy areas of necrosis. Concurrent with these changes, there were significant, progressive reductions in hemolytic titers, splenocyte plaque-forming counts, viable splenocytes, and the in-vitro splenocyte response to stimulation with concanavalin A. Graft-versus-host disease following intestinal allotransplantation damages the host's lymphoid tissues, producing profound immunosuppression. This finding has implications for clinical intestinal transplantation.

A prolactin-dependent, metastasising rat mammary carcinoma as a model for endocrine-related tumour dormancy

In order to study the growth kinetics of breast tumours during long-term hormonal withdrawal, we developed a transplantable, invasive mammary carcinoma EMR-86 that originated in a female WAG/Olac rat bearing a subcutaneously implanted oestrogen pellet (EP). Outgrowth of transplanted tumours occurs only in the presence of an EP, and metastases are formed in lungs and regional lymph nodes. Subsequent EP removal induces rapid regression. However, tumours do not disappear completely, as small nodules persist. These dormant tumour remnants can be restimulated even after long periods. Because EP-stimulated tumours regressed after treatment with bromocriptine and dormant tumours in non-oestrogenized rats grew out after treatment with perphenazine, prolactin is the major growth-stimulating hormone in this model. Cell kinetics in the growing, regressing and dormant phase were studied by immunocytochemical detection of DNA-incorporated bromodeoxyuridine (BrdUrd) in tissue sections. BrdUrd labelling indices decreased from 21.6 +/- 3.0% to less than 1% within 7 days after EP removal. After prolonged hormonal withdrawal (up to 90 days) BrdUrd-labelled tumour cells could always be demonstrated (range 0.4-0.8%), without a concomitant increase in tumour volume. Additional treatment either with bromocriptine or with ovariectomy could not significantly reduce this residual proliferative activity, as demonstrated by continuous BrdUrd labelling experiments. The results indicate that in vivo dormancy may represent a steady state of cell division and cell loss, rather than an accumulation of cells in a non-cycling G0 state.

Development of an interphase fluorescent in situ hybridization (FISH) test to detect t(8;21) in AML patients

The translocation (8;21) is a chromosome abnormality associated with acute myeloid leukemia (AML). As a consequence of the translocation the AML1 (CBFA2) gene in the 21q22 region is fused to the ETO(CDR,MTG8) gene in the 8q22 region, resulting in one transcriptionally active gene on the 8q- derivative chromosome. In this report we demonstrate the use of a highly specific dual-colour FISH method for the detection of t(8;21) on interphase cells. Genomic probes able to detect the chimeric AML1/ETO gene on the 8q- derivative chromosome were assayed on both normal and leukemic bone marrow and peripheral blood samples. Cut-off values were established by independent analysis of 15 bone marrow specimens negative for the translocation. The cut-off value of positive nuclei was determined to be 2% and the cut-off value for both positive nuclei and nuclei of uncertain classification, 4%. Persistence of cells above these cut-off values was interpreted as persistence of the mutated clone. A total of 36 samples at different disease stages were tested. Interphase cytogenetics detected the translocation at the onset and relapse in the BM or the PB of 14 AML patients with t(8;21). The technique appears to be an alternative tool to both conventional cytogenetics and reverse transcription polymerase chain reaction (RT-PCR) for the monitoring of disease during patients' follow-up. By enabling the analysis of individual cells, interphase FISH is ideal for clonality studies both for clinical and experimental applications.

Variation in circumferential resection margin: Reporting and involvement in the South-Netherlands

BACKGROUND

Since the introduction of total mesorectal surgery the outcome of rectal cancer patients has improved significantly. Involvement of the circumferential resection margin (CRM) is an important predictor of increased local recurrence, distant metastases and decreased overall survival. Abdomino perineal excision (APE) is associated with increased risk of CRM involvement. Aim of this study was to analyze reporting of CRM and to identify predictive factors for CRM involvement.

METHODS

A population-based dataset was used selecting 2153 patients diagnosed between 2008 and 2013 with primary rectal cancer undergoing surgery. Variation in CRM reporting was assessed and predictive factors for CRM involvement were calculated and used in multivariate analyses.

RESULTS

Large variation in CRM reporting was found between pathology departments, with missing cases varying from 6% to 30%. CRM reporting increased from 77% in 2008 to 90% in 2012 (p < 0.001). CRM involvement significantly decreased from 12% to 6% over the years (p < 0.001). In multivariate analysis type of operation, low anterior resection or APE, did not influence the risk of CRM involvement. Clinical T4-stage [odds ratio (OR) = 3.51; 95% confidence interval (CI) = 1.85-6.65) was associated with increased risk of CRM involvement, whereas neoadjuvant treatment (5 × 5 gray radiotherapy [OR 0.39; CI 0.25-0.62] or chemoradiation therapy [OR 0.30; CI 0.17-0.53]) were associated with significant decreased risk of CRM involvement.

CONCLUSION

Although significant improvements are made during the last years there still is variation in reporting of CRM involvement in the Southern Netherlands. In multivariate analysis APE was no longer associated with increased risk of CRM involvement.

IMARI: multi-Interventional program for prevention and early Management of Anastomotic leakage after low anterior resection in Rectal cancer patIents: rationale and study protocol

Background

Anastomotic leakage (AL) is still a common and feared complication after low anterior resection (LAR) for rectal cancer. The multifactorial pathophysiology of AL and lack of standardised treatment options requires a multi-modal approach to improve long-term anastomotic integrity. The objective of the IMARI-trial is to determine whether the one-year anastomotic integrity rate in patients undergoing LAR for rectal cancer can be improved using a multi-interventional program.

Methods

IMARI is a multicentre prospective clinical effectiveness trial, whereby current local practice (control cohort) will be evaluated, and subsequently compared to results after implementation of the multi-interventional program (intervention cohort). Patients undergoing LAR for rectal cancer will be included. The multi-interventional program includes three preventive interventions (mechanical bowel preparation with oral antibiotics, tailored full splenic flexure mobilization and intraoperative fluorescence angiography using indocyanine green) combined with a standardised pathway for early detection and active management of AL. The primary outcome is anastomotic integrity, confirmed by CT-scan at one year postoperatively. Secondary outcomes include incidence of AL, protocol compliance and association with AL, temporary and permanent stoma rate, reintervention rate, quality of life and functional outcome. Microbiome analysis will be conducted to investigate the role of the rectal microbiome in AL.

In a Dutch nationwide study, the AL rate was 20%, with anastomotic integrity of 90% after one year. Based on an expected reduction of AL due to the preventive approaches of 50%, and increase of anastomotic integrity by a standardised pathway for early detection and active management of AL, we hypothesised that the anastomotic integrity rate will increase from 90 to 97% at one year. An improvement of 7% in anastomotic integrity at one year was considered clinically relevant. A total number of 488 patients (244 per cohort) are needed to detect this difference, with 80% statistical power.

Discussion

The IMARI-trial is designed to evaluate whether a multi-interventional program can improve long-term anastomotic integrity after rectal cancer surgery. The uniqueness of IMARI lies in the multi-modal design that addresses the multifactorial pathophysiology for prevention, and a standardised pathway for early detection and active treatment of AL.

Trial registration

Trialregister.nl (NL8261), January 2020.

Effect of hormone depletion on cell survival in the EMR-86 rat mammary carcinoma

Growth of the transplantable EMR-86 rat mammary carcinoma depends on elevated prolactin levels which are induced by oestrogenic stimulation of the pituitary. We investigated histological and cell kinetic changes during tumour regression after removal of implanted oestrogen pellets (EP), and we especially focused on the role of apoptosis. After EP removal, serum prolactin decreased to basal levels in 5 days, reaching its largest depletion during the first day. Similarly, S-phase cell fractions, assessed by bromodeoxyuridine (BrdUrd) incorporation, decreased to half the initial value during the first day and developed into a gradual decrease to basal levels thereafter. Within 10 days, tumour volumes were reduced to 20% without striking changes in tissue architecture. To quantify apoptosis, we applied a method that stains DNA breaks in tissue sections and subsequently measured the stained area by automated image cytometry. This procedure was necessary, as the subtle changes could not be detected by histological examination alone. One day after the rapid decline of the S-phase fraction, a 3-fold increase in apoptotic area was observed that remained for about 3 days and then gradually decreased. This correlated with the histologically observed reduction of tumour cells. In spite of the major cell loss, regression came to a halt after about 10 days. The surviving cell fraction is discussed within the context of a stem cell hypothesis, in which tumour cells with stem cell characteristics are less susceptible to hormone-induced apoptosis than their (non-stem) daughter cells. This notion has implications for the eradication of residual tumour cells, because a diminished susceptibility might also apply to apoptosis induced by radio- or chemotherapy.

Cell-cycle-related staining patterns of anti-proliferating cell nuclear antigen monoclonal antibodies. Comparison with BrdUrd labeling and Ki-67 staining

Monoclonal antibodies (MAbs) to nuclear antigens are increasingly used as tools to obtain valuable information concerning the proliferative characteristics of various types of cancer. Prerequisite for the application of these MAbs in surgical pathology is establishment of the level of expression and/or cellular distribution of the antigens in relation to distinct cell-cycle compartments. In this study the topologic distribution of proliferating cell nuclear antigen (PCNA), an auxiliary protein of DNA polymerase delta, as recognized by human autoantiserum (AK) and two recently developed MAbs (19A2 and 19F4), was evaluated. Using cultured human cancer cells as a model system, and providing optimal fixation/permeation procedures are applied, these antibodies display a high affinity for PCNA bound to nuclear replicon clusters, resulting in distinct granular staining patterns. A more diffuse nucleoplasmic PCNA staining was mainly restricted to non-S-phase cells; in methanol-fixed cells, staining intensity of this form relative to the replicon-bound form appeared higher after staining with 19A2 than with 19F4 or AK. Comparing PCNA expression (detected with 19A2) with the expression of the Ki-67 antigen, PCNA-negative cells are also Ki-67 negative. In MCF-7 human breast cancer cells treated with 10(-6) mol/l (molar) tamoxifen, the fraction of nuclei showing replication patterns decreased from 42% to 8% within 8 days, but PCNA and Ki-67 antigens remained detectable in most cells during this interval, indicating a relatively slow decrease of antigen expression in cells that have entered a quiescent state. Treatment of MCF-7 cells with 10(-6) mol/l methotrexate resulted in a rapid accumulation of cells with an early S-phase DNA content; PCNA replication patterns showing a frequency distribution reflecting this DNA content were observed up to 48 hours after treatment. This indicates that the presence of replication patterns as visualized with anti-PCNAs is not a measure of replicative activity per se. It is concluded that, providing nuclear non-S-phase PCNA staining is faint relative to staining of replicon clusters, anti-PCNA antibodies may be excellent markers to detect in situ cells with S-phase DNA contents.

Standard versus Pre-emptive Antibiotic Treatment to Reduce the Rate of Infectious Outcomes after Whipple resection (SPARROW): a study protocol for a multicentre, open-label, randomised controlled trial

BACKGROUND

Consensus and evidence on the impact of pre-emptive antibiotic treatment after pancreatoduodenectomy is lacking, which is reflected by contradictory recommendations in (inter)national guidelines and current clinical practice. Pre-emptive antibiotic treatment may reduce the risk of abdominal surgical site infections in patients with a high risk of contaminated bile undergoing pancreatoduodenectomy. This pertains mostly patients with preoperative biliary drainage or an ampullary malignancy. The SPARROW trial will evaluate the effect of pre-emptive antibiotic treatment in patients with preoperative biliary drainage or an ampullary malignancy undergoing pancreatoduodenectomy.

METHODS

The SPARROW trial is a multicentre, open-label, randomised controlled trial evaluating the effect of pre-emptive antibiotic treatment in patients with a high risk of contaminated bile undergoing pancreatoduodenectomy. A total of 366 evaluable patients will be included in twelve centres in the Netherlands. Patients will be randomly allocated to either the perioperative antibiotic prophylaxis and pre-emptive antibiotic treatment (intervention) arm and the perioperative antibiotic prophylaxis (control) arm. In both study arms, the perioperative antibiotic prophylaxis consists of cefazolin, metronidazole and a single-dose of gentamicin, which is discontinued after surgery. In the pre-emptive antibiotic treatment arm, an additional antibiotic course of 5 days of cefuroxime and metronidazole is started postoperatively. The primary outcome is a clinically relevant organ/space surgical site infection (OSI) up to 90 days after surgery. Secondary outcomes include other clinically relevant complications (such as isolated OSI, superficial incisional surgical site infections, postoperative pancreatic fistula, ICU admission, readmission, and in-hospital and 90-day mortality), use of therapeutic antibiotics, and concordance between perioperative obtained bile cultures and cultures obtained from infectious complications.

DISCUSSION

The SPARROW trial will provide evidence on the effect of pre-emptive antibiotic treatment in patients with a high risk of contaminated bile undergoing pancreatoduodenectomy to provide recommendations for an improved and standardised antimicrobial policy.

TRIAL REGISTRATION

ClinicalTrials.gov NCT0578431. Registered on March 23, 2023.

Nationwide implementation of the international multidisciplinary best-practice for locally advanced pancreatic cancer (PREOPANC-4): study protocol

BACKGROUND

The introduction of (m)FOLFIRINOX and gemcitabine-nab-paclitaxel has changed the perspective for patients with locally advanced pancreatic cancer (LAPC). Consequently, in experienced centres 23% of patients with LAPC undergo a resection with 5-year overall survival (OS) rates of up to 25%. In the Netherlands, the nationwide resection rate for LAPC remains low at 8%. The PREOPANC-4 program aims for a nationwide implementation of the international multidisciplinary best-practice to improve patient outcome.

METHODS

Nationwide program implementing the international multidisciplinary best-practice for LAPC. In the training phase, multidisciplinary and surgical webinars are given by 4 international experts, leading to a clinical protocol, followed by surgical off-site and on-site proctoring sessions. In the implementation phase, the clinical protocol will be implemented in all centres, including a nationwide expert panel (2022-2024). Healthcare professionals will be trained in shared decision-making. Consecutive patients diagnosed with pathology-proven LAPC (i.e., arterial involvement > 90° and/or portomesenteric venous > 270° involvement or occlusion [DPCG criteria]) are eligible. Primary outcomes are median and 5-year OS from diagnosis, resection rate, in-hospital/30-day mortality and major morbidity (i.e., Clavien-Dindo grade ≥ IIIa), and radical resection (R0) rate. Secondary outcomes include quality of life, functioning, side effects, and patients' healthcare satisfaction in all included patients. Outcomes will be compared with patients with borderline resectable pancreatic cancer (BRPC) treated with neoadjuvant FOLFIRINOX in the PREOPANC-2 trial (EudraCT: 2017-002036-17) and a historical cohort of patients with LAPC from the PACAP registry (NCT03513705). The existing prospective LAPC Registry and PACAP PROMs (NCT03513705) will be used for data collection. In qualitative interviews, treatment preferences, values, and experiences of LAPC patients, their relatives, and healthcare professionals will be assessed for the development of shared decision-making supportive tools. It is hypothesized that the program will double the nationwide LAPC resection rate to 16% with major morbidity < 50% and mortality ≤ 5%, and OS following resection similar to that observed in patients with BRPC.

DISCUSSION

The PREOPANC-4 program aims to safely implement the international multidisciplinary best-practice for LAPC leading to benchmark outcomes for both short-term morbidity, mortality, and OS.

TRIAL REGISTRATION

PREOPANC-4 program was registered at ClinicalTrials.gov (NCT05524090) on September 1, 2022.