A181 HIGHER CUMULATIVE HISTOLOGIC INFLAMMATORY BURDEN SCORE IS ASSOCIATED WITH THE RISK OF DEVELOPMENT OF COLORECTAL NEOPLASIA IN ULCERATIVE COLITIS

Background

Ulcerative colitis (UC) patients have an elevated risk of colorectal neoplasia (CRN). Younger age at diagnosis, extent of colitis, and longer duration of colitis, as well as increased severity, which is a component of the cumulative inflammatory burden score (CIB), have been associated with the development of CRN. CIB was developed based on a large cohort of UC patients from St. Mark’s Hospital (UK) but needs further validation in independent cohorts.

Purpose

We analyzed the association between higher histologic CIB and development of CRN in longstanding UC patients.

Method

A matched case-control cohort of UC patients with at least 8 years of disease duration was analyzed at Mount Sinai Hospital. Patients with primary sclerosing cholangitis were excluded. Cases consisted of UC patients with colitis-associated neoplasia defined as indefinite for dysplasia (IND), low-grade dysplasia (LGD), high-grade dysplasia (HGD), or colorectal cancer (CRC). Each case was matched to two controls by age at disease onset, disease duration, and histological extent of colitis. Histologic reports obtained by colonoscopy were reviewed and histological activity was assessed as quiescent/normal (0), mild (1), moderate (2), and severe (3). The colonic area with the higher score was utilized and the CIB was calculated by summing each score and multiplying it by the interval of surveillance. A mean CIB (mCIB) was also calculated for each patient dividing the CIB by the number of colonoscopies. Continuous variables including CIB scores and mCIB scores were summarized as median and interquartile range (IQR) and differences between groups were compared by Mann-Whitney test.

Result(s)

Fifty-four UC patients were analyzed with 18 having CRN (6 CRC, 2 HGD, 3 LGD and 7 IND) and 36 controls without CRN. The clinical characteristics of the total cohort, cases and controls are depicted in the Table. Median age at last colonoscopy assessed was 45 years (36-55) and 40.7% were female. The median age at onset of UC was 23 years (19-37) and median duration of UC was 16 years (11-23). All patients had extensive histologic colonic disease. There were no differences between cases and controls in interval of surveillance evaluated (7.5 vs 7.8 years, p = 0.7) and median number of colonoscopies with histologic assessment (4 vs 4, p =0.6). Cases with CRN had significantly higher CIB (11.4 vs 7.9, p = 0.02) and mCIB (2.9 vs 2.0, p = 0.02) compared to controls.

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Conclusion(s)

The histologic CIB score is associated with an increased risk of developing CRN in UC patients with similar age at onset of disease, disease duration and colitis extent. Given CIB reflects the severity of histologic inflammation over the years, treatment strategies to improve histologic inflammation could reduce the incidence of CRN in UC.

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Disclosure of Interest

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Synthesis and biochemical studies of dithioate DNA

Dithioate DNA was synthesized and used for various biochemical studies. Results from these studies indicate that dithioate DNA is a potent inhibitor of HIV Reverse Transcriptase, activates endogenous RNase H in HeLa cell nuclear extracts, and is a useful probe for studying protein-DNA interactions.

Lack of gender differences and large intrasubject variability in cytochrome P450 activity measured by phenotyping with dextromethorphan

Gender-based differences in cytochrome P450 (CYP) activity may occur due to endogenous hormonal fluctuations with the menstrual cycle, which are altered by oral contraceptives. This study assessed the average activity and within-subject variability in CYP3A4 and CYP2D6 in men, women taking Triphasil, and regularly menstruating women not receiving oral contraceptives. Thirty-three healthy volunteers participated in this 28-day pilot study (12 women receiving Triphasil) (OCs), 11 regularly menstruating women not on exogenous progesterone or estrogen (no OCs), and 10 men. CYP3A4 and CYP2D6 activities were phenotyped with dextromethorphan (DM) on study days 7, 14, 21, and 28 using urinary ratios of DM:3-methoxymorphinan (3MM) and DM:dextrorphan (DX), respectively. Serial blood concentrations of estrogen and progesterone and menstrual diaries were used to determine menstrual phase in both groups of women. Average urinary DM:3MM and DM:DX in the 28 extensive metabolizers of CYP2D6 did not differ between the three study populations (p = 0.86 and 0.93, respectively). Post hoc power analysis indicated that more than 1000 subjects would be needed for 80% power (alpha = 0.05) to detect a +/- 15% difference from the population mean in the urinary ratios of dextromethorphan and its metabolites 3MM and DX. Variability in CYP3A4 and CYP2D6 activity, characterized by intrasubject standard deviation, also did not differ. The varying doses of levonorgesterol and ethinyl estradiol in Triphasil, fluctuations in estrogen and progesterone, and menstrual phase did not influence CYP3A4 or CYP2D6 activity. It was concluded that CYP3A4 and CYP2D6 activity and intrasubject variability were not different in the three study populations, and thus a clinically important difference between men, women on Triphasil, and women not receiving oral contraceptives is unlikely. High inter- and intrasubject variability in DM:3MM and DM:DX were clearly demonstrated and limit the use of dextromethorphan to phenotype endogenous CYP3A4 and CYP2D6 activity.

Should pediatric emergency care be decentralized?: an out-of-hospital destination model for critically ill children

OBJECTIVES

A time-to-initial-stabilization model for out-of-hospital destinations of critically ill children (CICs) was developed. Application of this model to assess the impact of changes in different parameters of an emergency medical services for children (EMSC) system is described.

METHODS

A computer model created a 2,500-square-mile community containing ten community hospitals (CHs) and one pediatric critical care center (PCC). Community hospitals capable of providing initial immediate stabilization of CICs were defined as emergency departments accepting pediatrics (EDAPs). Critically ill children were randomly selected in proportion to population densities across the modeled community. Time to initial stabilization (TIS) was defined as the time to arrival at either an EDAP or a PCC or time to arrival at a non-EDAP CH + travel time for a team from the PCC to the non-EDAP CH + preparation/dispatch (P/D) time. The following parameters of the model were varied and their effect on TIS was evaluated: location of CHs, location of PCC, primary destinations for CICs, percent of CHs meeting EDAP standards, out-of-hospital compliance with designated hospitals for CICs, P/D time, and ambulance speed.

RESULTS

The computer model selected 1,000 CICs in accordance with the population densities of the community. The scenario with the shortest TIS was one in which every CH achieved EDAP designation (9.8 +/- 0.5 minutes). The scenario with the longest TIS involved a model in which every CIC was transported directly to the PCC (28.6 +/- 0.33 minutes). The number of EDAPs in a community and out-of-hospital compliance with use of EDAPs produced comparable effects on the TIS. Travel speeds had a direct effect on TIS but also exaggerated inefficiencies between scenarios. The P/D time had little effect on the TIS.

CONCLUSIONS

An out-of-hospital destination model has been developed with the ability to modify multiple EMSC system variables. Application of this model demonstrates the shortest times to stabilization of critically ill children occur in systems that maximize the number of hospitals that meet EDAP standards and decentralize pediatric emergency care.

Biochemical and physicochemical properties of phosphorodithioate DNA

The biochemical and physicochemical properties of DNA oligomers containing phosphorodithioate linkages in various configurations were evaluated. Duplex stability studies, which were carried out by thermal denaturation analysis with complementary unmodified DNA, indicated a highly cooperative process similar to completely unmodified duplexes. Oligomers containing phosphorodithioate linkages were found to have reduced melting temperatures relative to unmodified duplexes, with the degree of Tm depression paralleling the percent phosphorodithioate composition of the oligomer. Relative to activation of RNase H, DNA oligomers containing up to 50% phosphorodithioate linkages were able to direct RNase H degradation with the same efficiency as unmodified DNA while those containing from 50 to 100% acted with somewhat reduced efficiency. At limiting concentrations, an oligomer containing alternating phosphorodithioate and phosphate linkages was able to direct RNase H degradation of the target RNA in an extended incubation, while an unmodified oligomer did not. The nuclease resistance of phosphorodithioate-containing oligomers was evaluated in HeLa cell nuclear and cytoplasmic extracts, in human serum, and with nucleases S1 and DNase I. Oligomers containing alternating phosphorodithioate and phosphate were highly resistant to degradation in all systems. However, oligomers having more than one unmodified linkage separating phosphorodithioates were degraded rapidly by DNase I, while demonstrating stability to degradation in all other systems tested. These results indicate that phosphorodithioate-containing DNA oligomers are highly nuclease-resistant, are able to form stable duplexes with complementary nucleic acid sequences, and efficiently direct RNase H degradation of target RNA.

Extracellular proteases in developing chick neural retina

During retinal histogenesis, cells and their extensions migrate within the tissue to final positions. In order for the cells to move through the matrix of tissue, space must be made available. We report evidence that extracellular proteolytic activity might be associated with this process. (1) When embryonic chick neural retinal cells are seeded onto a substrate of rhodamine conjugated fluorescent gelatin, the tips of growing neurites remove the fluorescence from the substrate. (2) Latent gelatinolytic activity can be identified with soluble assays of homogenates of embryonic chick neural retina. (3) Zymogram analysis demonstrates the presence of high molecular weight bands of proteolytic activity. The activity is inhibited by 1.10 phenanthroline, suggesting that it is due to a metalloproteinase. Activity can be detected in supernatants of retinal cells grown in vitro. Gelatinolysis is not the only proteolytic activity detected in the retina. Addition of plasminogen to zymograms results in an additional band of activity.

Isolation of L-3-phenyllactyl-Leu-Arg-Asn-NH2 (Antho-RNamide), a sea anemone neuropeptide containing an unusual amino-terminal blocking group

Using a radioimmunoassay for the carboxyl-terminal sequence Arg-Asn-NH2, we have purified a peptide from acetic acid extracts of the sea anemone Anthopleura elegantissima. By classical amino acid analyses, mass spectrometry, and 1H NMR spectroscopy, the structure of this peptide was determined as 3-phenyllactyl-Leu-Arg-Asn-NH2. By using reversed-phase HPLC and a chiral mobile phase, it was shown that the 3-phenyllactyl group had the L configuration. Immunocytochemical staining with antiserum against Arg-Asn-NH2 showed that L-3-phenyllactyl-Leu-Arg-Asn-NH2 (Antho-RNamide) was localized in neurons of sea anemones. The L-3-phenyllactyl group has not been found earlier in neuropeptides of vertebrates or higher invertebrates. We propose that this residue renders Antho-RNamide resistant to nonspecific aminopeptidases, thereby increasing the stability of the peptide after neuronal release.

Neurones and neuropeptides in coelenterates

The first nervous system probably evolved in coelenterates. Many neurons in coelenterates have morphological characteristics of both sensory and motor neurones, and appear to be multifunctional. Using immunocytochemistry with antisera to the sequence Arg-Phe-NH2 (RFamide), RFamide-like peptides were demonstrated in the nervous systems of all classes of coelenterates. Using a radioimmunoassay for RFamide, three such peptides were isolated from the sea anemone Anthopleura elegantissisma and sequenced: less than Glu-Gly-Arg-Phe-NH2 (Antho-RFamide), less than Glu-Ser-Leu-Arg-Trp-NH2 (Antho-RWamide I) and less than Glu-Gly-Leu-Arg-Trp-NH2 (Antho-RWamide II). The general structure of these peptides can be described as less than Glu...Arg-X-NH2, where X is an aromatic amino acid. From the hydromedusa Polyorchis penicillatus, the peptide less than Glu-Leu-Leu-Gly-Gly-Arg-Phe-NH2 (Pol-RFamide I) was isolated, which also belongs to the less than Glu...Arg-X-NH2 family. Using specific antisera it was shown that all four peptides were located in neurones. Application of low doses of Antho-RFamide, or Antho-RWamide I or II induced contractions of endodermal muscles of sea anemones. This indicates that these neuropeptides play a role in neurotransmission.

Isolation of less than Glu-Gly-Leu-Arg-Trp-NH2 (Antho-RWamide II), a novel neuropeptide from sea anemones

Using a radioimmunoassay for the peptide sequence Arg-Phe-NH2 (RFamide), a novel peptide has been purified from acetic acid extracts of the sea anemone Anthopleura elegantissima. This peptide has the structure less than Glu-Gly-Leu-Arg-Trp-NH2, and was named Antho-RWamide II. Antho-RWamide II is a neuropeptide. Its structure is closely related to an earlier characterized neuropeptide from Anthopleura less than Glu-Ser-Leu-Arg-Trp-NH2 (Antho-RWamide I).

Isolation of less than Glu-Ser-Leu-Arg-Trp-NH2, a novel neuropeptide from sea anemones

Using a radioimmunoassay for the peptide sequence Arg-Phe-NH2, a peptide has been purified from acetic acid extracts of the sea anemone Anthopleura elegantissima. This peptide has the structure less than Glu-Ser-Leu-Arg-Trp-NH2. Using antisera to its carboxyterminal sequence Arg-Trp-NH2, the peptide was found to be exclusively localized in neurons of sea anemones, among them neurons associated with the sphincter muscle. This suggest that the peptide is a transmitter at neuromuscular junctions.

A solid-phase method for the quantitation of protein in the presence of sodium dodecyl sulfate and other interfering substances

We describe a simple assay for small amounts of protein that is insensitive to sodium dodecyl sulfate (SDS) or many common interfering substances including Tris and reducing sugars. For this reason, it is particularly useful in the analysis of protein content of samples prior to SDS electrophoresis. The assay consists of the following steps: (i) absorption of protein to nitrocellulose; (ii) fixation of the bound protein with methanol; (iii) staining of the bound protein with amido black; and (iv) elution and spectrophotometric measurement of the bound dye. The assay is sensitive to as little as 0.5 microgram of protein in 1 microliter of solution. Although SDS does not interfere appreciably with measurement, Nonidet-P40 does.

Isolation of pyroGlu-Gly-Arg-Phe-NH2 (Antho-RFamide), a neuropeptide from sea anemones

A radioimmunoassay has been developed for peptides containing the carboxyl-terminal sequence Arg-Phe-NH2 (RFamide). Using this radioimmunoassay and applying cation-exchange chromatography and HPLC, we have isolated an RFamide peptide from acetic acid extracts of the sea anemone Anthopleura elegantissima. Three different methods established that the structure of the Anthopleura RFamide peptide (Antho-RFamide) is pyroGlu-Gly-Arg-Phe-NH2. Comparison of synthetic and natural Antho-RFamide and their enzymatic breakdown products on six different HPLC columns confirmed the structure of the sea anemone peptide. Using synthetic Antho-RFamide as a standard in our radioimmunoassay, we measured high concentrations (3.2 nmol/g wet weight) of this peptide in extracts of Anthopleura. It is proposed that Antho-RFamide is a transmitter at neuromuscular synapses in sea anemones.

Arg-Phe-amide-like peptides in the primitive nervous systems of coelenterates

By using immunocytochemistry and radioimmunoassays, several substances resembling vertebrate or invertebrate neuropeptides have been found in the nervous systems of coelenterates. The most abundant neuropeptides were those related to the molluscan neuropeptide Phe-Met-Arg-Phe-amide (FMRFamide). Of antisera against different fragments of FMRFamide, those against RFamide were superior in recognizing the coelenterate peptide. Incubation of whole mounts with these RFamide antisera visualized the coelenterate nervous system in such a detail as has previously not been possible. By using a radioimmunoassay with a RFamide antiserum and [J-125]-YFMRFamide as tracer, the RFamide-like peptide from sea anemones was isolated. After cation-exchange chromatography, gelfiltration and HPLC, this peptide was obtained in a pure form.