Trifluridine/Tipiracil in Metastatic Colorectal Cancer: A UK Multicenter Real-world Analysis on Efficacy, Safety, Predictive and Prognostic Factors

BACKGROUND

The orally administered combination trifluridine/tipiracil has been approved as third line treatment in mCRC, demonstrating survival benefit and acceptable toxicity profile in the phase III RECOURSE study.

PATIENT AND METHODS

We performed a multicenter retrospective real-world analysis of patients with mCRC receiving trifluridine/tipiracil between 2016 and 2019 in eight cancer centers across the United Kingdom.

RESULTS

A total of 236 patients were included with median age of 69 years. All patients had received at least 2 lines of fluoropyrimidine-based chemotherapy doublet with oxaliplatin or irinotecan. About 10% of patients had ECOG ≥ 2. Median duration of trifluridine/tipiracil treatment was 3 months with an ORR of 2.1% and disease control rate of 21.6%. Median OS was 7.6 and median PFS 3.3 months. A dose reduction was required in 27% of patients, while 7.6% discontinued treatment due to toxicity. The most common grade 3 toxicities were neutropenia (34%), fatigue (10%), anemia (9%) and febrile neutropenia (5%). Baseline NLR <5 and CEA <200 had favorable prognostic (HR: 0.52 and 0.39, P≤ .001) and predictive value (OR: 4.1 and 6.7, P< .05). Development of grade 3 neutropenia predicted treatment response (OR: 0.32, P< .001). Following treatment with trifluridine/tipiracil 41% were referred for phase I trial or rechallenged with chemotherapy.

CONCLUSION

Trifluridine/tipiracil is well tolerated in refractory mCRC patients with comparable efficacy and toxicity profile to that of the phase III RECOURSE. Pretreatment NLR and CEA could serve as potential markers for patient selection, while treatment-induced grade 3 neutropenia predicted response. Prospective validation is needed.

ESPAC-5F: Four-arm, prospective, multicenter, international randomized phase II trial of immediate surgery compared with neoadjuvant gemcitabine plus capecitabine (GEMCAP) or FOLFIRINOX or chemoradiotherapy (CRT) in patients with borderline resectable pancreatic cancer

4505

Background: Patients with borderline resectable pancreatic cancer have poor survival and low resection rates. Neoadjuvant therapy may improve the outcome for these patients. The aim of this trial was to determine the feasibility and efficacy of a comparison of immediate surgery versus neoadjuvant GEMCAP or FOLFIRINOX or CRT. Methods: Eligible patients with NCCN defined borderline resectable (following central review of the baseline CT scan) and biopsy proven pancreatic cancer were randomised (stratified by centre) to receive immediate surgery, or neoadjuvant therapy of either 2 cycles of GEMCAP, or 4 cycles of FOLFIRINOX or 50.4Gy capecitabine-based CRT in 28 daily fractions over 5 ½ weeks. Patients were restaged at 4-6 weeks and underwent surgical exploration if still borderline resectable. Resected patients received adjuvant therapy. Follow up was 12 months. There was quality assurance of surgery and CRT. Primary endpoints were recruitment rate and resection rate (R1/R0). Secondary endpoints included overall survival and toxicity. A target of 90 patients was set to determine feasibility and resection rates. Rates will be presented as point estimates and survival compared across treatment arms using a log-rank test. Analyses will be on an ITT basis. Results: Between August 2014 and December 2018, 90 patients were randomised with 88 included in the full analysis set (32 immediate surgery, 20 GEMCAP, 20 FOLFIRINOX, 16 CRT). Median age was 63 years, 44% were men. WHO performance status was 0 and 1 in 45% and 55% respectively. Median CA19-9 was 603 kU/L at baseline. 44 (79%) patients completed neoadjuvant therapy. Recruitment rate was 21 patients per year. Resection rate was 62% for immediate surgery and 55% for neoadjuvant therapy (p=0.668). R0 resection rate on resected patients was 15% and 23% respectively (p=0.721). One year survival rate was 40% [95% CI, 26% – 62%] for immediate surgery and 77% [95%CI, 66% - 89%] for neoadjuvant therapy. Log-rank analysis showed an HR=0.27 [95% CI, 0.13 – 0.55]; χ2 (1) = 14.91, P<0.001. 9 out of the 51 neoadjuvant patients included in the safety set reported 12 serious adverse events of grade 3 or above. Conclusions: There was no difference in resection rate between arms, however neoadjuvant therapy had a significant survival benefit compared with immediate surgery. Clinical trial information: 89500674 .

Systemic inflammation, adjuvant chemotherapy, and survival in stage III colorectal cancer: Results from the ScotScan Colorectal Cancer Collaborative

228

Background: The systemic inflammatory response (SIR) is a poor prognostic marker in patients with colorectal cancer (CRC), and predicts poor outcome following adjuvant chemotherapy. Whether this may be influenced by chemotherapy regime is not known. The present study examined the relationship between the pre-operative SIR, adjuvant therapy regime, and survival of patients with stage III CRC in the ScotScan cohort. Methods: Patients with stage III CRC in Scotland (1997-2015, n= 317) and Norway (2000-17, n= 312) were included. The pre-operative SIR was measured using C-reactive protein (CRP≤10mg/L or > 10mg/L). Adjuvant status was categorised as none, 5-fluorouracil-only (5FU or capecitabine), or oxaliplatin-combination (Ox). Relationship with 3 year overall (OS) and cancer-specific survival (CSS) was examined. Results: Rates of Ox were comparable between cohorts (Scotland – 26% vs. Norway 28%), although more patients from Norway received single 5FU (4% vs. 19%, P= 0.005). 36% of each cohort were systemically inflamed. Ox was associated with superior OS (90%) and CSS (92%) when compared to 5FU (77% and 84%) and no therapy (61% and 72%, both P< 0.001). Stratified by SIR, patients with CRP≤10mg/L receiving Ox or 5FU had comparable 3yr OS greater than those receiving none (90% vs. 88% vs. 67%), whereas those with CRP > 10mg/L receiving Ox had superior survival than those receiving 5FU or no therapy (89% vs. 64% vs. 53%, P-for interaction = 0.101). Results were similar for CSS (CRP≤10mg/L: 91% vs. 94% vs. 79%; CRP > 10mg/L: 94% vs. 72% vs. 62%, P-for interaction= 0.01). Although patients receiving Ox were younger and less comorbid, both use of Ox and SIR remained independently associated with OS and CSS. Conclusions: Although selection bias in the choice of adjuvant therapy may confound analysis, this study suggests the SIR may aid in determining response to adjuvant therapy. Whereas non-inflamed patients with stage III CRC may benefit from single 5FU, those with an elevated SIR may benefit greater from more intensive, Ox-based regimes. These results remain to be validated, however support the use of the SIR as a prognostic and predictive biomarker in patients with stage III CRC.

Prognostic phenotypic subtypes to predict recurrence and response to adjuvant chemotherapy for colorectal cancer

205

Background: Histological phenotypic subtypes have been proposed that stratify survival in a discovery cohort of patients with stage I-III colorectal cancer (CRC). However, clinical utility has not been validated nor associations with recurrence and chemotherapy assessed. Therefore, this study assessed prognostic value in patients with stage I-III CRC as well as predictive value for recurrence and chemotherapy response. Methods: Two independent stage I-III CRC patient cohorts were utilized to assess associations between phenotypic subtypes, survival, and recurrence. Stage II-III patients, from the SCOT adjuvant chemotherapy trial, were utilized to assess associations between phenotypic subtypes and adjuvant chemotherapy response. Log rank analysis compared immune and stromal subtypes. Results: In an 867-patient internal cohort, phenotypic subtype stratified patients by disease-free survival (DFS) (HR 2.18 95% CI 2.26-4.47, p < 0.001); independent of stage and location. The stromal subtype also predicted increased local and distant recurrence (p < 0.001). In a 146-patient external validation cohort, phenotypic subtype significantly stratified patients by DFS (HR 3.43 95% CI 1.60-7.35, p = 0.001). In 1343 SCOT trial patients, phenotypic subtype significantly stratified patients by DFS (HR 1.59 95% CI 1.13-2.25, p = 0.010). Furthermore, there was evidence that the effect of regimen depended on phenotypic subtype (p = 0.048), only significantly stratifying DFS in patients receiving FOLFOX (HR 3.73 95% CI 1.58-8.81, p = 0.003) but not CAPOX (HR 0.84 95% CI 0.56-1.26, p = 0.396) adjuvant chemotherapy. Interestingly, the immune subtype associated with improved DFS in patients receiving FOLFOX compared to CAPOX adjuvant chemotherapy (HR 3.40 95% CI 1.41-8.19, p = 0.006). Whereas patients with a stromal subtype trended towards improved DFS in patients receiving CAPOX compared to FOLFOX adjuvant chemotherapy (HR 0.72 95% CI 0.50-1.05 p = 0.088). Conclusions: Histological phenotypic subtypes are an effective independent prognostic classification for patients with stage I-III CRC that can predict response to FOLFOX adjuvant chemotherapy as well as the presence of local and distant recurrence.

Prospective DPYD testing and dose adjustment in colorectal cancer patients prior to fluoropyrimidine-based chemotherapy: Experience in a regional cancer center

93

Background: The fluoropyrimidines (FP), 5-Fluorouracil (5-FU) and capecitabine are a mainstay of colorectal cancer (CRC) treatment. Dihydropyrimidine dehydrogenase (DPYD), an enzyme encoded by the DPYD gene, is the initial and rate-limiting step in pyrimidine catabolism, deactivating over 80% of 5-FU. Approximately 5% of the population are deficient in DPYD and can develop severe or fatal FP toxicities. Currently, few national guidelines recommend routine prospective DPYD testing. In July 2019, we commenced a 6 month prospective pilot, testing DPYD status of all CRC patients undergoing first FP treatment in a large regional cancer centre. Methods: All CRC patients eligible for first exposure to FP are tested using a rapid molecular assay screening for five SNPs (detects 70% of DPYD mutations) and we will present data on prevalence of each. We will use electronic chemotherapy prescribing records (July 19-Jan 20) to collect information on dose modifications and toxicities. Once the pilot is completed we will perform a cost-effectiveness analysis. Results: Data from the first 3 months of this pilot have been reviewed and 201 patients have been tested with 15 heterozygotes identified, of which 2 had more than one mutation. No homozygotes were found. All heterozygote patients are started with a dose reduction (or have alternative therapy). One patient treated at 50% dose was hospitalised with several grade 3 toxicities despite dose reduction. Two patients have had subsequent dose escalation (by 25%). Nine patients have received one dose reduced cycle without complication. Three patients are due to start dose-reduced treatment. Conclusions: Routine prospective testing of DPYD status in a large regional cancer centre is feasible and with a sufficiently swift result turnaround to permit up-front dose modification. Detailed toxicity analysis and cost-effectiveness data will be presented.

NuTide: 302—A phase Ib study of the ProTide NUC-3373 in combination with standard therapies in advanced colorectal cancer

TPS274

Background: Although 5-FU-based regimens such as FOLFOX and FOLFIRI remain the cornerstone of treatment for patients (pts) with colorectal cancer (CRC), their clinical utility is limited by resistance mechanisms and toxicity. Anti-cancer activity of 5-FU is dependent on conversion to an active metabolite, fluorodeoxyuridine-monophosphate (FUDR-MP), which binds to and inhibits thymidylate synthase (TS), a critical enzyme in de novo nucleotide synthesis and cell survival. However, due to multiple limitations including: reliance on enzymatic activation; catabolism by dihydropyrimidine dehydrogenase (DPD) and a short plasma half-life, 5-FU is not efficiently converted to FUDR-MP. NUC-3373, a phosphoramidate transformation of FUDR-MP, was designed to bypass the key resistance mechanisms that limit the clinical utility of 5-FU. NUC-3373 demonstrated a favorable PK/PD profile and promising efficacy signals in the first-in-human study (NuTide:301) in pts with advanced solid tumors. NUC-3373 has a longer plasma t1/2 (9.7 hours) than 5-FU (8-14 minutes) and generates high intracellular levels of FUDR-MP (Ghazaly et al ESMO, 2017). TS is efficiently inhibited and sequestered into TS-ternary complexes, depleting the pool of deoxythymidine monophosphate (dTMP) within 2-4 hours. Methods: NuTide:302 is a three-part, Phase Ib study in pts with advanced CRC who have relapsed after ≥2 prior lines of 5-FU-containing therapies. Primary objective is to identify a RP2D of NUC-3373 when administered weekly and q2w in combination with standard agents used in CRC treatment. Secondary objectives include safety, PK/PD and anti‐tumor activity. In Part 1, patients are receiving NUC-3373 with leucovorin (LV) to determine if LV augments TS inhibition. In Part 2, NUC-3373 (±LV) will be administered in dose escalating cohorts, in a modified 3+3 design, with either oxaliplatin (NUFOX) or irinotecan (NUFIRI). In Part 3, the NUFOX and NUFIRI regimens selected in Part 2 will be combined with biologics targeting VEGF or EGFR pathways. To date, 22 pts have received study treatment. Recruitment is ongoing in the US and Europe. Clinical trial information: NCT03428958.

PRIMUS-002: A multicentre, open-label, phase II study examining FOLFOX and nab-paclitaxel (FA) and nab-paclitaxel and gemcitabine (AG) as neoadjuvant therapy for (borderline) resectable pancreatic cancer (PC), focusing on biomarker and liquid biopsy development

TPS4166

Background: There is increasing evidence suggesting benefit from a neoadjuvant approach to PC. However, the optimal regimen is unclear and will likely require a precision medicine approach, where patient and tumor attributes define therapy. Platinum-containing regimens have shown survival benefit for PC, with occasional exceptional responders, but biomarkers (BM) of response are not well defined and treatment decisions are often based on patient performance status (PS) and co-morbidity. Tumors with defects in BRCA1/2and other Fanconi Anemia genes show defective DNA damage response (DDR), conferring potential selective sensitivity to DNA-damaging agents (e.g. platinum) and newer targeted agents. We have shown that DDR deficiency (DDRd) is present in up to 20% of PC. This study aims to exploit DDRd as a therapeutic vulnerability, with integrated analysis to define candidate BM for FA and AG response. Methods: PRIMUS-002 will enroll patients registered on the Precision-Panc Master Protocol who are molecularly profiled using the Precision-Panc Clinical Cancer Genome including a novel DDRd assay, and the transcriptome with longitudinal sampling (pre-, during, and post-treatment). Patients receive either FA ( nab-paclitaxel 150mg/m2IV,oxaliplatin 85mg/m2, folinic acid 350mg flat dose, fluorouracil infusion 2400mg/m2continuous IV infusion), orAG ( nab-paclitaxel 125mg/m2, gemcitabine 1000 mg/m2) for 3 months,based on patient age and PS.Following initial safety analysis, chemoradiation may be introduced. The primary endpoint is disease progression (DP) during neoadjuvant therapy. The study is designed to detect a 20% difference in DP between the BM+ve (10%) and BM –ve (30%) in patients treated with FA (90% power, 5% 1-sided level of statistical significance)., Exploratory translational endpoints include surrogate therapeutic response assessment using CA19.9, PET-CT SUV, DWI-MRI and ctDNA. Current Enrolment: 2 patients enrolled to date: 1 to receive FA and 1 to AG treatment. Clinical trial information: ISRCTN34129115.

Aspirin as adjuvant treatment for colorectal cancer: Rationale and progress of the Add-Aspirin trial

TPS3624

Background: There is now a body of evidence indicating a potential role for aspirin in colorectal cancer (CRC) prevention. In cardiovascular trials, effects on incidence of cancer metastases and short-term mortality suggest further possible roles in the treatment setting, supported by observational studies of aspirin use after cancer diagnosis. In the prevention setting, aspirin use has been limited by toxicity concerns, particularly of serious bleeding. In the adjuvant setting, benefits associated with reducing recurrence and subsequent treatment may outweigh these risks. The Add-Aspirin trial will investigate this, and will also consider possible mechanisms of action for aspirin effects, including the impact of PIK3CA mutations, where there are currently several theories and conflicting data. Methods: Add-Aspirin (ISRCTN74358648) is an international, phase III, double-blind, randomised, placebo-controlled trial recruiting patients who have undergone surgery and relevant adjuvant treatment for stage II or III CRC, as well as those with completely resected CRC liver metastases. Parallel randomised cohorts will address the question in breast, gastro-oesophageal and prostate cancer. Participants take aspirin 100mg daily for an 8-week run-in, to assess adherence and toxicity, and those suitable to proceed are randomised (1:1:1) to aspirin 100mg, aspirin 300mg or placebo daily for at least 5 years. A number of measures – including blood pressure control and PPI use where relevant - are in place to reduce bleeding risk. The primary outcome is disease-free survival (target hazard ratio = 0.8, n = 2600 in 5 years) with a long term analysis of survival planned across the tumour groups. Translational work includes a sub-study monitoring urinary thromboxane B2 as a marker of platelet activation in a subgroup (n = 500) to investigate mechanisms of action. Add-Aspirin opened in 2015 and recruited 1505 CRC patients during the first 3 years from 137 UK centres. 1282 (85%) proceeded to randomisation. A pre-planned feasibility analysis of run-in data (n = 2253 across all 4 tumour groups) provided reassuring data on safety, tolerability and adherence, and recruitment continues with centres in India and Republic of Ireland recently joining. Clinical trial information: 74358648.

NuTide:302: A phase Ib study to assess the safety, pharmacokinetics and clinical activity of the ProTide NUC-3373 when combined with standard agents used in colorectal cancer

TPS719

Background: Although 5-fluorouracil-based chemotherapies (5-FU, capecitabine, and floxuridine) remain the cornerstone of combination therapies for colorectal cancer (CRC), their clinical utility is limited by key cancer resistance mechanisms associated with breakdown, transport, and activation. These agents require intracellular conversion to the active metabolite fluorodeoxyuridine-monophosphate (FUDR-MP) before they can exert their core anti-cancer activity through inhibition of the enzyme thymidylate synthase (TS). NUC-3373 is a phosphoramidate transformation of FUDR-MP designed to bypass the key resistance mechanisms associated with 5-FU. Results from the first-in-human study of NUC-3373 (NuTide:301) in patients with advanced solid tumours demonstrated a favourable PK/PD profile for NUC-3373, with a longer plasma t1/2 (9.7 hours) than 5-FU (8-14 minutes) and much higher levels of the active anti-cancer metabolite, FUDR-MP (Ghazaly et alESMO, 2017). TS is efficiently inhibited and sequestered into TS-ternary complexes (TS-T), depleting the pool of dTMP within 2-4 hours. Methods: NuTide:302 is a two-part, Phase Ib study in patients with CRC who have relapsed after ≥ 2 prior lines of 5-FU-containing therapies. The primary objective is to identify a recommended NUC-3373 dose when administered every 2 weeks in combination with standard agents used in CRC treatment. Secondary objectives include safety, PK/PD, and anti‐tumour activity. In Part 1, approximately 12 patients will be administered NUC-3373 with leucovorin (LV) to determine if LV is beneficial in augmenting the formation of TS-T. If so, it will be administered in Part 2. In Part 2, the following combination agents will be administered with NUC-3373 (±LV): oxaliplatin; oxaliplatin + bevacizumab; oxaliplatin + panitumumab; irinotecan; and irinotecan + cetuximab. Up to 62 patients will be enrolled in cohorts of 3-6, in a modified 3+3 design. Enrollment to Part 1 initiated in September 2018. Clinical trial information: NCT03428958.

Real-world experience of trifluridine/tipiracil in patients with metastatic colorectal cancer: A multicenter United Kingdom study

668

Background: TAS-102 is an orally administered combination of the thymidine-based nucleic acid analogue, trifluridine and the thymidine phosphorylase inhibitor, tipiracil hydrochloride. Following the phase III RECOURSE study, it received approval as third line treatment for metastatic colorectal cancer showing significant improvement in overall and progression free survival and an acceptable toxicity profile. Methods: We performed a multicenter retrospective observational study of patients with metastatic colorectal cancer receiving TAS-102 as third line treatment between 2016 and 2018 in Cancer centers across the UK. Results: A total of 143 patients were included (94 men, 49 women). Median age was 68 years (35-82). All patients had received at least 2 lines of fluoropyrimidine-based chemotherapy doublet with oxaliplatin or irinotecan. About 90% of patients had ECOG ≥ 1. Median duration of treatment was 2.9 months (0.5-22.9), with a response rate of 1.6% and stable disease achieved in 24%. Median OS was 7 months (95% CI 5.84-8.15) and median PFS 2.6 months (95% CI 2.2-3.36). A dose reduction was required in 28% of patients, while 8% discontinued treatment due to toxicity. AEs reported included fatigue 81.3% (G3 16.8%), nausea 34.5% (G3 4.5%) and diarrhoea 25.5% (G3 1.8%). Neutropenia was common 50.4%, (≥ G3: 25.4%) with 4.2% cases of neutropenic fever while thrombocytopenia was less frequent 8.7% (≥ G3 1.8%). Conclusions: The OS, PFS and ORR observed in our real-world experience were consistent with the RECOURSE trial, though we noted a lower disease control rate. Overall, TAS-102 was well tolerated and the most prevalent adverse events seen in our patients were in keeping with those reported in the trial. Although severe toxicities were less frequent than the trial, we experienced higher rates of toxicity induced dose reductions and treatment cessations, which could reflect the differences between trial and real world populations. Further validation is warranted.

Pancreatic cancer genomics: where can the science take us?

The incidence of pancreatic ductal adenocarcinoma (PDAC) is steadily increasing and the annual death-to-incidence ratio approaches one. This is a figure that has not changed for several decades. Surgery remains the only chance of cure; however, only less than 20% of patients are amenable to operative resection. Despite successful surgical resection, the majority of the patients still succumb to recurrent metastatic disease. Therefore, there is an urgent need to develop novel therapeutic strategies and to better select patients for current therapies. In this review, we will discuss current management by highlighting the landmark clinical trials that have shaped current care. We will then discuss the challenges of therapeutic development using the current randomized-controlled trial paradigm when confronted with the molecular heterogeneity of PDAC. Finally, we will discuss strategies that may help to shape the management of PDAC in the near future.

Randomized phase II trial comparing the efficacy and safety of nintedanib versus sorafenib in patients with advanced hepatocellular carcinoma (HCC)

238

Background: Nintedanib (N) is an oral, triple angiokinase inhibitor of vascular endothelial growth factor (VEGF), platelet-derived growth factor (PDGF), and fibroblast growth factor (FGF) receptors. This randomized, multicenter, open-label, phase II study (NCT01004003; 1199.37) evaluated the efficacy and safety of N versus sorafenib (S) in patients with advanced HCC. Methods: Enrolled patients had unresectable advanced HCC, ECOG-PS ≤2, Child–Pugh score 5–6, alanine/aspartate aminotransferase (ALT/AST) ≤2× upper limit of normal, and ≥1 untreated measurable lesion or a previously treated lesion with progression (by RECIST 1.0). Patients were randomized 2:1 to N 200 mg bid or S 400 mg bid continuously in 28-day cycles, until intolerable adverse events (AEs) or disease progression (PD); treatment beyond PD was allowed if clinical benefit was perceived. Primary endpoint was time to progression (TTP) by independent central review (ICR; RECIST 1.0), and secondary endpoints were overall survival (OS) and investigator-assessed (IA) TTP. Results: Ninety-three patients were randomized to receive N (n=62) or S (n=31). At the cutoff date (15 July 2014), 77% of patients had a TTP event, and 70% had an OS event; 3 patients remained on treatment with 1 patient beyond PD. IA TTP was comparable between N and S (median 5.5 vs 3.8 months; HR 1.05 [95% CI: 0.63–1.76]), as was OS (median 11.9 vs 11.4 months; HR 0.88 [95% CI: 0.52–1.47]). ICR TTP data are pending. All patients reported an AE (CTCAE 3.0); more patients treated with S had Grade ≥3 AEs (68% vs 90%). AEs leading to dose reduction were higher with S (19% vs 42%), whereas AEs leading to drug discontinuation were higher with N (45% vs 23%). The only tyrosine kinase inhibitor class-specific AE reported in >15% of patients was hand-foot skin reaction in the S arm. AEs previously observed with N and higher in this arm were diarrhea, vomiting, nausea, and AST increase, while blood bilirubin increase was higher with S. Rash was reported in >15% of patients only in the S arm. Conclusions: N shows similar efficacy to S with respect to TTP and OS, with a manageable safety profile. Further studies of N in patients with advanced HCC are warranted. Clinical trial information: NCT01004003.

Role of neoadjuvant treatment regimens for locally advanced pancreatic cancer

444

Background: Pancreatic ductal adenocarcinoma (PDAC) is a leading cause of cancer-related mortality worldwide. Lymph node involvement and resection margin status play important roles in predicting relapse. Resectable disease occurs in only 15–20% of total patients who present with PDAC. Unfortunately, margin involvement (R1) occurs in 70–80% of these patients. Emerging evidence has shown that the use of neoadjuvant chemotherapy and localised radiotherapy to downsize the tumours and increase the margin clearance (R0) rate may improve the overall survival of PDAC patients.We report a neoadjuvant therapy approach in the non-clinical trial setting of our large, tertiary cancer centre. Methods: We prospectively collected the outcome data and toxicity of 53 patients diagnosed with borderline resectable or initially non-resectable PDAC between 2012 and 2014. These patients received either FOLFIRINOX (FFX) or Gemcitabine/Capecitabine (GemCap) combination chemotherapies. Following restaging by computed tomography (CT), the patients proceeded to preo-operative 5-FU-based chemo-radiotherapy, immediate resection or subsequent palliativetherapies. Results: The median age was 65 (range 30 – 79) at PDAC diagnosis. Sixty-one percent (n=32) were male with the commonest anatomical location being the head of the pancreas (58%, n=31). The median follow up for survivors is 13.7 months (range: 5.3–24.4). The median overall survival was 18.3 months (95%, CI: 12.0–24.5). There was no statistical difference between overall survival in patients receiving FFX and GemCap chemotherapies. The margin clearance rate (R0) was 36% (4/11) in patients who proceeded to resection after neoadjuvant chemotherapy alone. The rate was 100% (4/4) in patients who received additional chemoradiation prior to surgery. Conclusions: This case series reveals that neoadjuvant therapy improved survival of patients with PDAC. In addition, we showed an increase in the R0 resection rate in patients who underwent chemoradiation prior to surgery. Further work is ongoing but based on historical data we believe that this neoadjuvant approach may lead to a long term survival benefit.

FOLFIRINOX chemotherapy in locally advanced and metastatic pancreatic adenocarcinoma: A retrospective analysis of toxicity and outcomes

436

Background: The FOLFIRINOX chemotherapy regimen has been shown to improve overall survival in patients with metastatic pancreatic cancer, however, toxicity is increased. The aim of this analysis was to assess the tolerability and outcomes of this regimen in clinical practice. Methods: A retrospective analysis of patients treated with FOLFIRINOX chemotherapy in a tertiary referral centre between January 2013 and May 2014 was conducted. Toxicity was graded as per CTCAE version 4.0. Overall survival and tumour response were analysed. Results: A total of 80 patients were identified with locally advanced or metastatic disease in 47 and 33 cases respectively. The median patient age was 63 (range 30 –79) and the median number of cycles delivered was 6 (range 1-12). G3/4 neutropenia was recorded in 12.5% of patients, with a febrile neutropenia rate of 9.9%. G3/4 nausea and vomiting was reported in 17.5% and G3/4 diarrhoea in 15% of cases. G3/4 electrolyte disturbance occurred in 5%. Response rates assessed after 3-6 cycles showed PR 26%, SD 31% and PD 25%. Median duration of follow up for survivors is 8.7 months (range 3.6 – 20.8). Median OS is 11.4 months (95% CI 10.1 – 12.7). Median OS was reported as 11.4 months, 10.9 months and 2.3 months according to baseline PS 0, 1 and 2 respectively (log rank p <0.001). Conclusions: FOLFIRINOX can be safely delivered out with a trial cohort. Outcomes are strongly influenced by patient PS and careful patient selection is critical.

Metabolic activation of sulfur mustard leads to oxygen free radical formation

We recently published electron paramagnetic resonance (EPR) spin trapping results that demonstrated the enzymatic reduction of sulfur mustard sulfonium ions to carbon-based free radicals using an in vitro system containing sulfur mustard, cytochrome P450 reductase, NADPH, and the spin trap α-(4-pyridyl-1-oxide)-N-tert-butylnitrone (4-POBN) in buffer (A.A. Brimfield et al., 2009, Toxicol. Appl. Pharmacol. 234:128-134). Carbon-based radicals have been shown to reduce molecular oxygen to form superoxide and, subsequently, peroxyl and hydroxyl radicals. In some cases, such as with the herbicide paraquat, a cyclic redox system results, leading to magnified oxygen free radical concentration and sustained tissue damage. Low mustard carbon radical concentrations recorded by EPR in our in vitro system, despite a robust (4.0mM) sulfur mustard starting concentration, led us to believe a similar oxygen reduction and redox cycling process might be involved with sulfur mustard. A comparison of the rate of mustard radical-POBN adduct formation in our in vitro system by EPR at atmospheric and reduced oxygen levels indicated a sixfold increase in 4-POBN adduct formation (0.5 to 3.0 μM) at the reduced oxygen concentration. That result suggested competition between oxygen and POBN for the available carbon-based mustard radicals. In parallel experiments we found that the oxygen radical-specific spin trap 5-tert-butoxycarbonyl-5-methylpyrroline-N-oxide (BMPO) detected peroxyl and hydroxyl radicals directly when it was used in place of POBN in the in vitro system. Presumably these radicals originated from O(2) reduced by carbon-based mustard radicals. We also showed that reactive oxygen species (ROS)-BMPO EPR signals were reduced or eliminated when mustard carbon radical production was impeded by systematically removing system components, indicating that carbon radicals were a necessary precursor to ROS production. ROS EPR signals were completely eliminated when superoxide dismutase and catalase were included in the complete in vitro enzymatic system, providing additional proof of oxygen radical participation. The redox cycling hypothesis was supported by density functional theory calculations and frontier molecular orbital analysis.

A cutaneous full-thickness liquid sulfur mustard burn model in weanling swine: clinical pathology and urinary excretion of thiodiglycol

Sulfur mustard (bis(2-chloroethyl)sulfide, HD) is a well-known blistering chemical warfare agent. We have developed a cutaneous full-thickness HD burn model in weanling pigs for efficacy testing of candidate treatment regimens. This report addresses clinical pathology findings and the urinary excretion profile of a major HD metabolite (thiodiglycol, TDG) in this model. Six female Yorkshire pigs were exposed to HD liquid on the ventral surface for 2 h, generating six 3-cm diameter full-thickness dermal lesions per pig. Blood samples were collected throughout a 7-day observation period for hematology and serum chemistry examinations. Urine was collected in metabolism cages. Routine urinalysis was performed and the urine analyzed for TDG using gas chromatography/mass spectrometry. Examination of clinical pathology parameters revealed subtle HD-related changes that are suggestive of a mild hemolytic episode. No other signs of clinically significant systemic toxicities were noted, including bone marrow suppression. Thiodiglycol was detected at the earliest time point tested (6-8 h post-exposure) at levels ranging from 0.66 to 4.98 microg ml(-1) with a mean of 2.14 microg ml(-1). Thiodiglycol concentrations were the highest for half of the animals at this earliest time point and at 24-48 h for the others. By the evening of day 3, the mean level had reached 50 ng ml(-1). Mean levels remained 10-40 ng ml(-1) for the remainder of the 7-day observation period, with the highest individual concentration noted during this period of 132 ng ml(-1). Our results are in general agreement with the TDG excretion profiles previously described for rodent models and humans. Urinary excretion of absorbed HD in our weanling pig wound healing model appears to follow the same pattern as is seen in other laboratory animals models. In general, urinary excretion of TDG appears to peak within the first 1-4 days following exposure, with detectable levels after 1 week. Relatively high urinary TDG levels may thus indicate agent exposure within the previous 96 h. Low levels significantly above natural background levels may indicate either exposure to low levels of agent or exposure that occurred more than 4 days prior to collection of the sample.

Detection and measurement of sulfur mustard offgassing from the weanling pig following exposure to saturated sulfur mustard vapor

Animal models are employed to investigate mechanisms of injury and to evaluate protective measures against sulfur mustard (HD) exposure. The ability to detect and quantify HD enables the researcher to follow safe procedures in handling skin samples. We designed an experimental procedure to measure HD offgassing from animal models. A Minicams--a portable gas chromatograph equipped with a flame photometric detector and on-line sorbent collection and desorption--was used to monitor the HD concentration. Confirming measurements were made using a two-step process that trapped HD on a Tenax sorbent off-line and then transferred the sample by means of an ACEM 900 to a gas chromatograph equipped with either a flame photometric detector or a mass spectrometer. Sulfur mustard offgassing data are presented from three experiments in which weanling pigs were exposed to saturated HD vapor via vapor caps containing 10 microl of HD. The HD concentration was measured in time-weighted-average (TWA) units at a specific HD application site. The current 8-h maximum exposure limit for HD is 3-ng l(-1), (1 TWA unit). The largest TWA value measured near a 3 h time point was a Minicams measurement of 0.48 TWA at 2 h and 53 min after removal of a vapor cap containing HD from a single exposure site on an animal that had 24 concurrent dorsal exposure sites. Gas chromatography/flame photometric detection and gas chromatography/mass spectrometry were used to confirm the Minicams data and to provide greater sensitivity and selectivity down to 0.1 TWA. The gas chromatography/mass spectrometry data confirmed that HD concentrations fell below 0.1 TWA in <5 h for a specific site. These measurements of HD concentrations provided information on the expeditious and safe handling of HD-exposed tissue.

Conformational stabilities of the rat alpha- and beta-parvalbumins

It is widely believed that beta-parvalbumin (PV) isoforms are intrinsically less stable than alpha-parvalbumins, due to greater electrostatic repulsion and an abbreviated C-terminal helix. However, when examined by differential scanning calorimetry, the apo-form of the rat beta-PV (i.e. oncomodulin) actually displays greater thermal stability than the alpha-PV. Whereas the melting temperature of the a isoform is 45.8 degrees C at physiological pH and ionic strength, the Tm for the beta isoform is more than 7 degrees higher (53.6 degrees C). This result suggests that factors besides net charge and C-terminal helix length strongly influence parvalbumin conformational stability. Extension of the F helix in the beta-PV, by insertion of Ser-109, has a modest stabilizing effect, raising the Tm, by 1.1 degrees. Truncation of the alpha-PV F helix, by removal of Glu-108, has a more profound impact, lowering the Tm by 4.0 degrees.

Sensitivity of cross-reacting antihuman antibodies in formalin-fixed porcine skin: including antibodies to proliferation antigens and cytokeratins with specificity in the skin

Although no animal is a perfect skin model for the study of toxicological and therapeutic agents, structurally the pig may be superior to even non-human primates. Because our work involves effects of toxicological and therapeutic agents on the skin, we wanted to identify stains which may prove useful as well as determine cross-reactivity of some newer antihuman antibodies. We performed a battery of formalin-fixed skin from weanling pigs and minipigs. The battery of antibodies included LCA, CD3, OPD-4, CD34, UCHL-1, L-26, KP-1, MAC-387, Factor XIIIa, Leu-7, S-100 protein, HMB-45, GFAP, synaptophysin, neurofilament protein, ubiquitin, vimentin, type IV collagen, laminin, fibronectin, Factor VIII related antigen, Desmin-M, smooth muscle actin, cytokeratin 7, cytokeratin 20, AEI/AE3, CAM 5.2, EMA, GCDFP, Ki-67, and PCNA. Immunohistochemical stains for CD3, Leu-7, S-100 protein, type IV collagen, laminin, Factor VIII related antigen, GFAP, synaptophysin, neurofilament protein, ubiquitin, smooth muscle actin, vimentin, Desmin-M, cytokeratin 7, cytokeratin 20, AE1/AE3, CAM 5.2, Ki-67 and PCNA showed consistent cross-reactivity. In formalin-fixed tissue, only antibodies to lymphoreticular cells showed poor cross-reactivity. A high percentage of the remaining antibodies did show good cross-reactivity but with some interesting similarities and differences in specificity.

Histopathologic and immunohistochemical features in human skin after exposure to nitrogen and sulfur mustard

N-methyl-2,2'-dichlorodiethylamine (HN2)is a topical chemotherapeutic agent used as therapy for cutaneous T-cell lymphomas (CTCL). Di(2-chloroethyl)sulfide (SM), and less often HN2, have been used as chemical weapons, with the skin being a principle target. The mechanisms by which these chemicals produce their therapeutic and toxic effects in skin, however, are not clearly defined. We exposed human skin explants to two doses of HN2 and SM. At 18 hours after exposure, histopathologic features were compared. In addition, immunohistochemical markers to basement membrane proteins were used to evaluate the effects of both chemicals on the basement membrane zone. Gross vesication was not seen. Pyknotic nuclei with or without dyskeratotic changes within epidermal keratinocytes were present at both doses. These changes varied more between skin specimens than they did between doses. Ballooning degeneration was more marked after SM exposures. Diffuse dermal-epidermal separation was present only at high-dose exposures and did not appear to correlate with the degree of changes locally in the overlying epidermis. Antibodies to laminin-5 showed decreased immunoreactivity after exposure to HN2 and SM. Immunoreactivity for laminin- was decreased to a lesser extent, and immunoreactivity for collagen IV and VII was unchanged. HN2 and SM produce similar histopathologic and immunohistochemical features after cutaneous exposure. These features suggest that part of mechanism of action of HN2 and SM is a direct effect on the basement membrane zone. Understanding the effects of HN2 and SM separate from their effect on DNA may be important in designing therapies and in advancing our understanding of the pathophysiologic changes induced by these chemicals when delivered topically.

Increased smooth muscle actin, factor XIIIa, and vimentin-positive cells in the papillary dermis of carbon dioxide laser-debrided porcine skin

BACKGROUND

Pulsed carbon dioxide (CO2) laser debridement is now being used as therapy for photodamaged skin. It has been proposed that the long duration of erythema and a tissue scaffold, which results from tightening of the collagen helix induced by the laser heat, may lead to tightening of sagging skin and skin creases of lesser magnitude.

METHODS

Weanling pigs exposed to mild and moderate erythema producing doses of sulfur mustard (bis-2-chloroethyl sulfide; HD) were treated with the CO2 laser (Tru-Pulse) at 6, 24, and 48 hours after exposure. In addition to histologic examination of laser-debrided and nondebrided biopsy specimens obtained at 14 days after exposure, immunohistochemical staining with antibodies to smooth muscle actin, Factor XIIIa, vimentin, and CD3 was performed.

RESULTS

CO2 laser debridement of the HD-exposed skin resulted in clearing of the cytologic atypia induced by this chemical carcinogen and reduced the inflammatory infiltrate. In addition laser debridement resulted in increased numbers of stromal cells within the papillary dermis, which showed immunohistochemical staining for smooth muscle actin, Factor XIIIa, and vimentin.

CONCLUSIONS

CO2 laser debridement is effective in clearing the epidermis of cytologically damage cells in HD as well as solar-damaged skin. In addition CO2 laser debridement may result in tightening of sagging skin and produce a decrease in skin creases initially, by inducing increased stromal cells within the papillary dermis, with prominent contractile actin filaments. The collagen produced by these stromal cells may subsequently maintain these improvements in the photoaged skin.

Immunohistochemical studies of basement membrane proteins and proliferation and apoptosis markers in sulfur mustard induced cutaneous lesions in weanling pigs

Sulfur mustard (2,2-dichlorodiethyl sulfide, HD) is a chemical warfare agent that is a threat to both troops and civilians. The focus of HD research has been on intracellular adduct formation leading to apoptosis and/or necrosis in cutaneous lesions. However, there is work which suggests that HD may have a more direct effect on the basement membrane zone. Immunohistochemical staining to desmosomal proteins, cellular fibronectin, laminin 1, laminin 5, collagen IV, collagen VII, p53, Bcl-2, and PCNA was performed on weanling pig skin exposed to vesicating doses of HD, GB3, an antibody to laminin 5, showed a progressive decrease with loss of expression during the time period of clinical vesiculation. The other basement membrane proteins showed no change or inconsistent changes. PCNA, and p53 staining increased in the overlying epidermis in areas of vesiculation without significant necrosis. Bcl-2 positive cells were decreased or absent after exposure. This study implicates laminin 5 as the main basement membrane protein affected acutely by HD exposure. The patterns of staining of PCNA, Bcl-2, and p53 within the epidermis suggest that apoptosis and cellular necrosis both may play a role in cell death secondary to HD.

Depth of morphologic skin damage and viability after one, two, and three passes of a high-energy, short-pulse CO2 laser (Tru-Pulse) in pig skin

BACKGROUND

CO2 laser energy is absorbed by water, which is present in all tissue. The depth of penetration of CO2 lasers is narrow with minimal reflection, scatter, or transmission. However, thermal damage has limited the usefulness of conventional, continuous-wave CO2 lasers for debridement as demonstrated by wound healing studies. The development of high-energy CO2 lasers, with pulse durations that are less than the thermal relaxation time of tissue, have made vaporization of skin for resurfacing and wound debridement possible because of the decreased risk of thermal damage.

OBJECTIVE

This study was performed to evaluate thermal damage produced by a CO2 laser.

METHODS

Routine histopathologic examination and nitroblue-tetrazolium chloride (NBTC) staining were used to evaluate the depth of tissue damage and viability in weanling pig skin after one, two, and three passes of the laser.

RESULTS

At a pulse energy of 300 mJ, with a pulse duration of 60 microseconds, one pass of the laser produced vaporization of the epidermis with minimal thermal damage. Two passes produced areas of denatured collagen with loss of viable cells in the superficial papillary dermis. Three passes extended the damage into the papillary dermis.

CONCLUSION

Hyalinization of collagen appears to correspond well with the level of thermal damage as measured by NBTC staining. Our findings suggest that the energy necessary to vaporize the dermis may be greater than that needed to vaporize epidermis.

Construction and characterization of the soybean leaf metalloproteinase cDNA

The cloning and analysis of a cDNA clone encoding the soybean metalloproteinase obtained by polymerase chain reaction (PCR) and the rapid amplification of cDNA ends (RACE) reaction are described. The cDNA was constructed from poly(A)+ RNA isolated from 15-17 day old leaves. The deduced amino acid sequence of the cDNA reveals that the plant metalloproteinase is synthesized as a preproenzyme and the proenzyme form shares a structural motif, responsible for maintenance of inactive zymogen, with the matrix metalloproteinase (e.g. collagenase) family of enzymes from vertebrate origin. Northern and Western blot analysis demonstrated that the metalloproteinase transcript and protein are under a strict developmental program in that both are expressed only in leaf tissue and in a temporal fashion. The physiological function of the metalloproteinase still remains unclear although the data suggest that the enzyme is extracellular and a portion of the mature form of the enzyme is tightly bound to the cell wall.

Evaluation of cross-reacting anti-human antibodies in the euthymic hairless guinea pig model (HGP) suggests that the HGP may be a model for the study of proliferative skin disease

Animal models have an important role in cutaneous research. The guinea pig has proven to be a useful model in a wide spectrum of these cutaneous studies; however, its usefulness is often compromised by the need for depilation. A euthymic hairless guinea pig (HGP) model avoids the problems associated with depilation. Morphologically, as in human skin, these animals have a multi-cell-layer epidermis. Proliferation kinetic studies, as well as documentation of the degree of immunologic cross-reactivity between available antibodies to human cutaneous antigens, could extend the usefulness of this animal model. We performed a battery of anti-human antibodies on formalin fixed tissue, to a variety of antigens present within the skin and on inflammatory cells. These included CD3, UCHL-1, OPD4, L-26, KP-1, Factor XIIIa, S-100 protein, cytokeratin (AE1, AE3 and CK1), CAM 5.2, vimentin, CD 34, Factor VIII, fibronectin, SM actin, collagen IV, laminin, Bcl-2, p53, Ki-67, and PCNA. Cross-reacting antibodies included: CD3, S-100 protein, cytokeratin (AE1, AE3 and CK1), vimentin, Factor VIII, SM actin, collagen IV, p53, Ki-67, and PCNA. Although this battery of antibodies is limited, the markedly increased staining of Ki-67 and PCNA within keratinocytes in the epidermis as compared to normal human skin reflects a high proliferative rate. In addition, positive staining for p53, Ki-67, and PCNA may be useful in studying effects on cell cycle kinetics and apoptosis.

Purification and molecular analysis of an extracellular gamma-glutamyl hydrolase present in young tissues of the soybean plant

A polypeptide present in intercellular wash fluids of young leaves of Glycine max has been purified to electrophoretic homogeneity. The protein has been identified as gamma-glutamyl hydrolase (GGH) based on the shared homology with a recently cloned cDNA from rat. The enzyme is present within the extracellular space of young leaves and a portion is bound to the cell wall. Northern and Western analysis confirm that this polypeptide is expressed only in young (1-15 d old) leaf, stem and root tissue and is therefore expressed under a strict developmental program. The primary sequence of gamma-glutamyl hydrolase shares amino acid identity with a cDNA clone from rat and two partially sequenced cDNAs from Arabidopsis. Although the complete in vivo function of gamma-glutamyl hydrolase in plants is unclear, it is known that the protein plays a critical role in folate metabolism and therefore likely in meeting the physiological demands of growing plant tissues.

Percutaneous versus open tracheostomy: a retrospective cohort outcome study

Percutaneous tracheostomy has been advocated as a faster, safer, and less invasive method of placing tracheostomy tubes in ventilated patients. To compare outcome differences, as measured by complication rates, between percutaneous and open tracheostomy, a retrospective cohort study was performed. All procedures were performed in the intensive care unit of a university-affiliated hospital. The minor complication rates did not differ significantly between percutaneous and open tracheostomy (12/31 vs. 12/29, respectively; p > 0.05), nor did there appear to be a difference in rates of major complications between the two groups (7/31 vs. 5/29; p > 0.05). This study identified a trend towards an increased risk of delayed airway loss in the percutaneous tracheostomy group.

A review of computed tomography in the diagnosis of intestinal and mesenteric injury in pediatric blunt abdominal trauma

OBJECTIVE

To determine the sensitivity, specificity, and positive and negative predictive values of the computed tomography (CT) scan in the diagnosis of clinically significant intestinal and mesenteric injury in pediatric blunt abdominal trauma.

PATIENTS

The records of 145 children who presented to a tertiary care pediatric hospital between 1987 and 1994 were reviewed retrospectively. All had experienced single or multiple injuries and underwent CT as part of the trauma assessment.

METHODS

The patients were divided into two cohorts, based on the results of the initial CT scan: either positive (n = 20) or negative (n = 152) for evidence of intestinal or mesenteric injury. The two cohorts were similar with respect to age, trauma score, and timing of CT scan. The outcome of surgical (n = 23) and conservative management (n = 122) was compared with the initial CT scan results. (Some of the laparotomies were for solid-organ injury only.)

RESULTS

The sensitivity of the CT scan in the diagnosis of clinically significant intestinal and mesenteric injury is 0.93. The specificity and positive and negative predictive values are 0.95, 0.65, and 0.99, respectively.

CONCLUSION

The CT scan is an excellent test to screen for clinically significant intestinal and mesenteric injury in pediatric patients with blunt abdominal trauma. Because of the lower positive value, other clinical and diagnostic imaging information may help to improve diagnostic accuracy. Most importantly, CT rarely misses a significant intestinal or mesenteric injury.

Microtubule-associated protein 2 (MAP-2): a sensitive marker of seizure-related brain damage

We have assessed the efficacy of MAP-2 immunohistochemistry as a marker of seizure-related brain damage and its suitability for quantitation of the damage using densitometric and morphometric image analysis. Seizures were produced in rats by administration of 1.5 LD50 soman, an irreversible AChE inhibitor. Our results demonstrate that neuronal damage, assessed using hematoxylin and eosin, and cresyl violet staining, was colocalized on adjacent serial sections with clearly demarcated reductions in MAP-2 staining. The most severely damaged brain regions were devoid of MAP-2 staining. Reductions in MAP-2 immunostaining were found to be exceptionally well suited for quantitation using densitometric and morphometric image analysis. This study represents the first demonstration of seizure-induced excitotoxic alterations in MAP-2.

Histopathologic features seen in sulfur mustard induced cutaneous lesions in hairless guinea pigs

Sulfur mustard (SM), a chemical warfare agent first used early in the 20th century, has re-emerged in the past decade as a major threat around the world. At present, there are no effective therapeutic measures for SM exposure. Because the skin as well as other interface epithelial surfaces are the first tissues effected as this agent is absorbed, reactions within the skin are an area of active research into the mechanism of action of this alkylating agent. The euthymic hairless guinea pig has been used as the animal model for the study of SM induced injuries because of morphologic similarity of its skin to human skin, with a multiple layer epidermis, and because this animal has a normal immune system. We reviewed 102 biopsy specimens from 51 animals exposed to three different dose times of saturated SM vapor. Histopathologic evidence exists for increased programmed cell death as well as cellular necrosis, subepidermal blister formation, and delayed re-epithelialization secondary to problems with adhesion. Information obtained from this study adds to the body of information important in the investigation of the mechanisms of action of SM.

Staining mast cells for morphometric evaluation on an image analysis system

Multiple skin sections from three nonhuman primates (Macaca mulatta) and three hairless guinea pigs (Cavia porcellus) were stained with 12 different histologic stains to determine whether mast cells could be selectively stained for morphometric analysis using an image analysis system (IAS). Sections were first evaluated with routine light microscopy for mast cell granule staining and the intensity of background staining. Methylene blue-basic fuchsin and Unna's method for mast cells (polychrome methylene blue with differentiation in glycerin-ether) stained mast cell granules more intensely than background in both species. Toluidine blue-stained sections in the guinea pig yielded similar results. Staining of the nuclei of dermal connective tissue was enhanced with the methylene blue-basic fuchsin and toluidine blue stains. These two stains, along with the Unna's stain, were further evaluated on an IAS with and without various interference filters (400.5-700.5 nm wavelengths). In both the methylene blue-basic fuchsin and toluidine blue stained sections, mast cell granules and other cell nuclei were detected together by the IAS. The use of interference filters with these two stains did not distinguish mast cell granules from stained nuclei. Unna's stain was the best of the 12 stains evaluated because mast cell granule staining was strong and background staining was faint. This contrast was further enhanced by interference filters (500.5-539.5 nm) and allowed morphometric measurements of mast cells to be taken on the IAS without background interference.

Purification and partial amino acid sequence of a wound-inducible, developmentally regulated anionic peroxidase from soybean leaves

We have isolated a peroxidase activity to electrophoretic homogeneity from the leaves of the soybean plant, Glycine max. The highly anionic peroxidase isozyme has an isoelectric point of 3.7 and a molecular mass of 32 kilodaltons. Partial amino acid sequence information confirms the identity of the enzyme as a peroxidase but shows significant deviation from other plant peroxidases in the distal histidine box. The enzyme is developmentally regulated as it begins to accumulate in 8-10 day old leaves and its level remains fairly constant thereafter. The expression of this isozyme is also responsive to environmental cues in that it accumulates in young (less than 8 day old) leaves as a consequence of mechanical wounding. The appearance of the isozyme begins approximately 8 hr post-wounding and continues to accumulate for 48 hr.

Sequencing and characterization of the soybean leaf metalloproteinase : structural and functional similarity to the matrix metalloproteinase family

A novel zinc endoproteinase has been sequenced and characterized from soybean leaves (Glycine max var Williams 82) and has been designated as Protein Identification Resource accession No. A41820 SMEP1 (soybean metalloendoproteinase 1). Comparison of the primary amino acid sequence with other zinc proteinases revealed the enzyme to be a new member of the matrix metalloproteinase (MMP) family of enzymes. SMEP was found to have MMP cleavage specificity toward peptide substrates and the enzyme is specifically inhibited by naturally occurring tissue inhibitors of MMPs through a high-affinity interaction (inhibitor concentration resulting in an approximate 50% decrease in enzyme activity = 23 x 10(-9) molar). Together, these results suggest that the origin of the MMP family of enzymes and their cognate inhibitors predates the divergence of plants and animals.

Effect of ritanserin, a highly selective 5-HT2 receptor antagonist, on Parkinson's disease

There is both experimental and clinical evidence to suggest a role for 5-hydroxytryptamine (5-HT) in Parkinson's disease. The effect of ritanserin, a highly selective 5-HT2 receptor antagonist, on Parkinsonian symptomatology was investigated in 10 patients in a single-blind placebo-controlled study. Akinesia and gait improved significantly in a dose-dependent manner in 5 and 7 patients respectively. However there was no significant improvement in tremor. The effects of ritanserin on akinesia and gait are consistent with a role for 5-HT in Parkinson's disease.

Complete amino Acid sequence of soybean leaf p21 : similarity to the thaumatin-like polypeptides

A polypeptide structurally related to the thaumatin family of proteins has been purified from soybean (Glycine max) leaves and the complete amino acid sequence has been determined. The mature protein, which we have termed P21, has a calculated molecular weight of 21,461 and an isoelectric point of 4.6. The soybean protein shows 64% amino acid identity with thaumatin, a sweet-tasting protein found in the West African shrub Thaumatococcus danielli, and as much as 71% identity with thaumatin-like polypeptides present in tobacco and maize.

Purification and Developmental Analysis of a Metalloendoproteinase from the Leaves of Glycine max

A metalloendoproteinase from leaves of soybean (Glycine max) has been purified 1160-fold to electrophoretic homogeneity. The native protein is monomeric with a molecular mass of 15 kilodaltons as estimated by gel filtration and 19 kilodaltons as estimated by denaturing gel electrophoresis. The enzyme has a pH optima of 8.0 to 9.0 using Azocoll as substrate. The proteolytic activity is susceptible to metal chelating agents and the inactivated enzyme can be restored to 69% of original activity by the addition of ZnCl(2). Western analysis shows that a fraction of the soybean metalloendoproteinase is present within the extracellular space of older leaves. Soybean metalloendoproteinase 1 is the Azocollase A activity first described by Ragster and Chrispeels (Plant Physiol 64: 857-862; 1979).

Complete Amino Acid Sequence of a Polypeptide from Zea mays Similar to the Pathogenesis-Related-1 Family

A polypeptide serologically related to the tobacco pathogenesis-related-1 family of proteins has been purified from the root tissue of maize (Zea mays L.), and the complete amino acid sequence has been determined. The mature protein has a calculated molecular weight of 14,970 and isoelectric point of 4.2. The maize protein shows 66 to 68% amino acid identity with the tobacco pathogenesis-related-1 family and 55% identity with the tomato p14 protein.

Purification and Developmental Analysis of the Major Anionic Peroxidase from the Seed Coat of Glycine max

We show that the majority of peroxidase activity in soybean (Glycine max var Williams 82) seeds is localized to the seed coat. A single isozyme is responsible for this activity and has been purified to electrophoretic homogeneity by successive chromatography on DEAE Sepharose Fast Flow, concanavalin A-Sepharose, and Sephadex G-75. The peroxidase exhibits a pl of 4.1, an apparent molecular mass of 37 kilodaltons, and has properties characteristic of a glycoprotein. The enzyme begins to accumulate approximately 21 days after anthesis and continues to do so throughout the maturation of the seed coat where it can represent at least 5% of the soluble protein in dry seed coats. Due to its localization in the seed, we propose that this isozyme may play a role in the hardening of the seed coat.

A comparison of standard Madopar and controlled release Madopar in Parkinson's disease

In a randomised, double-blind cross-over study, objective measures were used to compare the effect of a single oral dose of a standard preparation of levodopa-benserazide (Madopar M) with a sustained-release preparation (Madopar HBS) in 9 Parkinsonian patients with 'end of dose deterioration'. The response of patients to an optimised regimen of each preparation was also assessed using a patient diary. In all patients the onset of effect of Madopar HBS following a single dose was delayed compared with Madopar M. The duration of effect of a single dose of Madopar HBS was substantially (38-120%) longer than Madopar M in five patients and the same or shorter in four patients. According to the patients' diaries, six patients noted an increase in 'on' hours while on Madopar HBS. The duration and severity of dyskinesia was similar for the two preparations. Madopar HBS is likely to be useful in some Parkinsonian patients with 'end of dose deterioration'. As the effect of each dose is delayed it is probably best given in combination with standard Madopar.

Phosphorylation status of nuclear and cytosolic androgen receptors in the rat ventral prostate

We demonstrate that endogenous phosphatases are active in cytosolic and nuclear androgen receptor fractions from the rat ventral prostate. Under our androgen binding assay conditions, the effect of acid phosphatase inhibitors (sodium fluoride, tartaric acid, sodium orthovanadate) on the endogenous phosphatases could be correlated with an increase in dihydrotestosterone (DHT) binding to fractions of partially purified cytosolic androgen receptor. In contrast, tetramisole, an alkaline phosphatase inhibitor, did not alter the binding of DHT to the same receptor fraction. Immunoprecipitation of androgen receptor fractions with polyclonal anti-phosphotyrosine antibody resulted in the recovery of [3H]-DHT binding activity from nuclear receptor fractions and partially purified cytosolic receptor fractions prepared from 20- to 24-hr castrated rats. In control fractions depleted of androgen receptor, negligible levels of binding activity were recovered following immunoprecipitation with the antibody. Therefore, acid phosphatases may be acting on phosphotyrosyl residues of the androgen receptor, thus playing a role in the dephosphorylation and inactivation of the androgen receptor.

Cardiomyopathy in Soman and Sarin intoxicated rats

Rats surviving various single dose of the organophosphorus anticholinesterase nerve agents Soman and Sarin were examined by light microscopy at intervals up to 35 days post-exposure. Brain lesions, identical to those that have been reported elsewhere were present, as well as a previously unreported finding associated with Soman or Sarin intoxication: half of all animals that had brain lesions also had areas of myocardial degeneration and necrosis. Depending upon the point in time at which cardiac tissues were examined, findings varied from areas of acute myolysis and necrosis to areas undergoing resolution of damage. The finding of brain lesions in those animals having cardiac lesions suggests a relationship between the convulsion induced neurologic and cardiac lesions. These studies suggest that convulsive doses of chemical warfare agents induce pathological changes in the cardiovascular system of laboratory animals.

Radiolabeling of a wound-inducible pyridoxal phosphate-utilizing enzyme: evidence for its identification as ACC synthase

1-Aminocyclopropane-1-carboxylic acid (ACC) synthase, a pyridoxal phosphate-utilizing enzyme, catalyzes the conversion of S-adenosylmethionine to ACC, the rate-limiting step in the biosynthesis of the plant hormone ethylene. We report the partial purification (400-fold) of ACC synthase from wounded pink tomato pericarp. Further purification results in a decrease in specific activity apparently due to the instability of the enzyme. Radiolabeling of a pyridoxal phosphate-utilizing protein in the ACC synthase-enriched fraction was achieved by reduction using tritiated sodium borohydride. Evidence that this radiolabeled protein is ACC synthase is presented.

Regulation of synthesis of proteinase inhibitors I and II mRNAs in leaves of wounded tomato plants

Levels of two wound-inducible serine proteinase inhibitors, called Inhibitor I and Inhibitor II, and their mRNAs were quantified in leaves of tomato (Lycopersicon escululentum (L.) Mill.) plants after wounding the leaves with a hemostat. A single wound on a lower leaf of 25-old tomato plants caused the accumulation of the two inhibitor proteins in wounded and non-wounded leaves beginning about 4-6 h following wounding. The rate of inhibitor accumulation was maximal in leaves for the next 4 h and then declined. By 20 h the accumulation had nearly ceased. Following a single wound, Inhibitor I mRNA [600 bases in length] and Inhibitor II mRNA (760 bases) began to accumulate in wounded leaves about 2 h before the inhibitor proteins could be detected. The levels of mRNA for both inhibitors reached a maximum at about 8 h following wounding and then decayed, both with apparent half lives of about 10 h. Four consecutive wounds, inflicted hourly, increased the levels of mRNA for both inhibitors to over twice the levels induced by a single wound. Within 4 h following multiple wounds, Inhibitor I mRNA represented about 0.5% of the total polyadenylated mRNA (poly(A(+))mRNA) and Inhibitor II mRNA about 0.15% of the total. The rates of accumulation of the two inhibitor proteins varied depending upon the age of the plants and their environment during growth, and ranged between 3 and 10 μg Inhibitor I·h(-1)·(g tissue)(-1) for Inhibitor I and about half of these rates for Inhibitor II. Nuclei were isolated from leaves of wounded and non-wounded plants, and in mRNA runoff experiments using specific inhibitor copy DNAs (cDNAs) as probes the synthesis of Inhibitor I and II mRNAs were shown to be regulated, at least in part, at the level of transcription.