A mechanistic biomarker investigation of fialuridine hepatotoxicity using the chimeric TK-NOG Hu-liver mouse model and in vitro micropatterned hepatocyte cocultures

Fialuridine (FIAU) is a nucleoside-based drug that caused liver failure and deaths in a human clinical trial that were not predicted by nonclinical safety studies. A recent report concluded that a TK-NOG humanized liver (hu-liver) mouse model detected human-specific FIAU liver toxicity, and broader use of that model could improve drug safety testing. We further evaluated this model at similar dose levels to assess FIAU sensitivity and potential mechanistic biomarkers. Although we were unable to reproduce the marked acute liver toxicity with two separate studies (including one with a "sensitized" donor), we identified molecular biomarkers reflecting the early stages of FIAU mitochondrial toxicity, which were not seen with its stereoisomer (FIRU). Dose dependent FIAU-induced changes in hu-liver mice included more pronounced reductions in mitochondrial to nuclear DNA (mtDNA/nucDNA) ratios in human hepatocytes compared to mouse hepatocytes and kidneys of the same animals. FIAU treatment also triggered a p53 transcriptional response and opposing changes in transcripts of nuclear- and mitochondrial-encoded mitochondrial proteins. The time dependent accumulation of FIAU into mtDNA is consistent with the ≥9-week latency of liver toxicity observed for FIAU in the clinic. Similar changes were observed in an in vitro micro-patterned hepatocyte coculture system. In addition, FIAU-dependent mtDNA/nucDNA ratio and transcriptional alterations, especially reductions in mitochondrially encoded transcripts, were seen in livers of non-engrafted TK-NOG and CD-1 mice dosed for a shorter period. Conclusion: These mechanistic biomarker findings can be leveraged in an in vitro model and in a more routine preclinical model (CD-1 mice) to identify nucleosides with such a FIAU-like mitochondrial toxicity mechanistic liability potential. Further optimization of the TK-NOG hu-liver mouse model is necessary before broader adoption for drug safety testing.

Incidence of retained biopsy specimens after esophagogastroduodenoscopy and colonoscopy

Background and study aims In gastrointestinal endoscopy, biopsies must transit through the accessory channel and cap, presenting an opportunity for loss of tissue. We sought to determine the incidence of specimen retention in the accessory channel or cap and identify procedure characteristics associated with specimen retention. Patients and methods After completion of standard endoscopic procedures in which biopsies were obtained, the biopsy cap and accessory channel were inspected, brushed, and irrigated for any retained biopsy specimens according to a standard protocol. For controls, the same protocol was applied to procedures in which biopsies were not obtained. Specimen bottles from the recovery protocol were sent for pathological examination regardless of whether any visible tissue was present. Results A total of 216 outpatient procedures were included: 55 esophagogastroduodenoscopies (EGDs) and 50 colonoscopies in which biopsies were obtained and 56 EGDs and 55 colonoscopies in the control group. Retained specimens were found in either the cap or channel in 50 of 105 (48%). In 20 of 105 (19%), retained specimens were found just in the cap, in six of 105 (5.7%), retained specimens were found just in the channel, while in 24 of 105 (23%), retained specimens were found in both the cap and channel. Retained specimens were more likely to be found in EGDs compared to colonoscopies (58% vs. 36%, P = 0.031). No retained specimens were found in the control group. Conclusions Retained specimens are startingly common in standard gastrointestinal endoscopic procedures and could potentially change diagnoses and management. Quality improvement measures should be instituted to monitor prevalence of retained biopsies and methods to prevent them should be developed.

Sustained barcode medication administration rates less than 2 percent in a large healthcare system

Purpose

Implementation of bar code medication administration (BCMA) technology is an effective strategy to decrease medication administration errors. Consistent use of BCMA technology within a hospital system should result in improved patient safety through the reduction of medication related administration errors. Based on this premise, a large health system established an annual goal to reduce BCMA override rates to less than 2%.

Methods

A large health system located in the Intermountain West developed a BCMA override reporting tool to assist with reducing BCMA override rates. An essential component of the reporting tool is the visual management strategy which allows caregivers to easily identify goal progress. The tool also includes information that managers can use to determine how often their direct reports override medications. Pharmacy caregivers can also use the data from the reporting tool to address specific issues related to medications that do not scan properly.

Results

Implementation of the tool and education on its use, resulted in individual follow up with nursing units and nurses, ultimately producing sustained barcode overrides less than 2%.

Conclusion

By implementing reporting systems that identifies specific opportunities for improvement, barcode override rates can be decreased to less than 2% in a large healthcare system.

Abstract 5078: Metaproteomic analysis of IBD associated colorectal cancer

Inflammatory bowel disease (IBD) increases the risk of developing colorectal cancer by 60%. The composition of gut flora and its interaction with mucosal cells plays a key role in the development of IBD and colorectal cancer. However, the actual cause-effect relationship between dysbiosis of the gut microbiome and human IBD and associated colorectal cancer has not been well established. In the current study, we sought to characterize colon mucosa adherent microbiota using metaproteomics to understand the colon micro-environment and the host-microbiome interactions. Three groups of colon biopsies were included in our analysis: healthy controls, Non-progressors (IBD patients without dysplasia or cancer) and Progressors (IBD patients who have dysplasia or cancer). The biopsy samples were analyzed by LC MS/MS and the bacterial proteins were identified using the Human Microbiome Project (HMP) human gut microbiome database. The inferences of bacterial taxonomy, bacterial enzymes and Gene ontology (GO) pathways were processed through Unipept. Examining bacterial composition between different sample groups showed no statistically significant difference at the levels of phyla and classes. However, a significant reduction of Holdemanella biformis was observed when comparing Progressors vs Non-progressors. Holdemanella biformis has recently been proposed to be endogenous anti-tumourigenic bacterial strains. Decrease of this bacterial species in Progressors suggested that it may be a protective bacteria preventing the progression of IBD associated colorectal cancer. Analysis of Gene Ontology (GO) biological processes identified GO terms that were significantly different among the Progressor, Non-progressor and healthy groups. For example, the GO term ‘detoxification of arsenic containing substances’ was significantly underrepresented in the Progressor group compared to healthy and Non-progressor groups. Furthermore, several bacterial enzymes were significantly different between the three groups. In particular, oxidoreductases were significantly decreased in the Progressor group compared to healthy and Non-progressor groups. While the implications of these significantly enriched or depleted bacterial biological processes and bacterial enzymes in the neoplastic progression of IBD warrant further investigation, the results from our current study provide new insight into understanding how gut microbiota as a modulator of microenvironment may contribute to progression of IBD-associated colorectal cancer.

Citation Format: Nobel Bhasin, Prerna Dabral, Victoria Poplaski, Lisa Lai, Hong-Yuan Tsai, Mary Bronner, Teresa Brentnall, John Valentine, Jordon March, Antone Opekun, Robert Britton, Pan Sheng, Ru Chen. Metaproteomic analysis of IBD associated colorectal cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 5078.

Proactive infliximab optimisation using a pharmacokinetic dashboard versus standard of care in patients with Crohn's disease: study protocol for a randomised, controlled, multicentre, open-label study (the OPTIMIZE trial)

INTRODUCTION

Preliminary data indicates that proactive therapeutic drug monitoring (TDM) is associated with better outcomes compared with empiric dose escalation and/or reactive TDM, and that pharmacokinetic (PK) modelling can improve the precision of individual dosing schedules in Crohn's disease (CD). However, there are no data regarding the utility of a proactive TDM combined PK-dashboard starting early during the induction phase, when disease activity and drug clearance are greatest. The aim of this randomised, controlled, multicentre, open-label trial is to evaluate the efficacy and safety of a proactive TDM combined PK dashboard-driven infliximab dosing compared with standard of care (SOC) dosing in patients with moderately to severely active CD.

METHODS AND ANALYSIS

Eligible adolescent and adult (aged ≥16-80 years) patients with moderately to severely active CD will be randomised 1:1 to receive either infliximab monotherapy with proactive TDM using a PK dashboard (iDose, Projections Research) or SOC infliximab therapy, with or without a concomitant immunomodulator (IMM) (thiopurine or methotrexate) at the discretion of the investigator. The primary outcome of the study is the proportion of subjects with sustained corticosteroid-free clinical remission and no need for rescue therapy from week 14 throughout week 52. Rescue therapy is defined as any IFX dose escalation other than what is forecasted by iDose either done empirically or based on reactive TDM; addition of an IMM after week 2; reintroduction of corticosteroids after initial tapering; switch to another biologic or need for CD-related surgery. The secondary outcomes will include both efficacy and safety end points, such as endoscopic and biological remission, durability of response and CD-related surgery and hospitalisation.

ETHICS AND DISSEMINATION

The protocol has been approved by the Institutional Review Board Committee of the Beth Israel Deaconess Medical Center (IRB#:2021P000391). Results will be disseminated in peer-reviewed journals and presented at scientific meetings.

TRIAL REGISTRATION NUMBER

NCT04835506.

Clinical utilisation of the Infant Monitor of vocal Production (IMP) for early identification of communication impairment in young infants at-risk of cerebral palsy: a prospective cohort study

AIM

To report prospective longitudinal data of early vocaliszations of infants identified "at-risk" of cerebral palsy (CP) for early identification of communication impairment.

METHOD

This case-control longitudinal prospective cohort study reports on the assessment of 36 infants, 18 identified as at-risk of CP at the time of enrolment and 18 typically developing (TD) children, at three time points: 6 months, 9 months and 12 months of age, Data were obtained through criterion and norm referenced assessments of vocaliszation behaviors.

RESULTS

Early vocal behaviors of infants identified as at-risk of CP did not differ from their age matched peers at 6 months of age, however, significant group differences emerged at 9 and 12 months when pre-canonical and canonical babble typically emerge. Generalized linear mixed models analysis showed that the rate of development of early language ability and more complex speech-related vocal behaviors was slower for infants at risk of CP when compared to TD infants, with over 75% of infants with CP showing below normal vocal production and impaired language by 12 months of age.

INTERPRETATION

Our data suggest characteristics of infant vocalizations associated with pre-canonical and canonical babbling provide a strong evidence base for predicting communication outcomes in infants at risk of CP.

CMV Disease in IBD: Comparison of Diagnostic Tests and Correlation with Disease Outcome

BACKGROUND

Significance of cytomegalovirus (CMV) in inflammatory bowel disease (IBD) is unclear due to pathobiology, numerous CMV tests, and disparate treatment outcomes.

METHODS

Retrospective chart review was done on patients with positive qualitative CMV tissue polymerase chain reaction (PCR) from 2005-2013 at a tertiary referral hospital. Frequency of PCR+, hematoxylin and eosin staining(HE)+, histopathology and immunohistochemistry (IHC)+ was assessed. IHC was assessed on a sample of PCR- tissues. Surgery rates were correlated with CMV testing and treatment.

RESULTS

PCR was done on 310 samples from 180 patients. Thirty-seven samples were PCR+ (51.4% PCR+ only, 35.1% IHC/PCR+, 13.5% HE/IHC/PCR+). The H&E frequently failed to detect CMV identified on extensive IHC. Of 13 PCR- samples tested with IHC, 100% were negative. Twenty-five patients were CMV+ (40% PCR+, 40% IHC/PCR+, 20% HE/IHC/PCR+). Surgery rates increased with number of positive tests: 60% in IHC/PCR+ and 80% in HE/IHC/PCR+, compared to 26.8% in PCR- or PCR+ (P = 0.03, P = 0.02, respectively). There were 20/25 PCR+ patients who received CMV treatment. Surgery occurred in 80% of HE+ patients despite treatment and 100% of IHC+ patients without treatment.

CONCLUSIONS

Rates of CMV+ testing and surgical risk varied by test modality. PCR+ results were most frequent but alone did not detect clinically significant CMV. HE+ testing was least frequent and associated with highest surgical rate, despite treatment. CMV treatment may benefit IHC+ patients most, supporting immunostaining as optimal diagnostic test for clinically significant CMV in IBD. In PCR+ samples, HE frequently did not detect CMV identified on extensive IHC. In PCR- samples, data suggest IHC is likely negative. Consider using qualitative PCR to guide extensive immunostaining.

Impact of periodontal intervention on local inflammation, periodontitis, and HIV outcomes

OBJECTIVE

The aim of this study was to determine active periodontal disease status in HIV and to determine the impact of periodontal disease resolution on HIV status.

METHODS

In this longitudinal cohort study, 73 HIV-positive subjects received comprehensive dental care. AAP, CDC/AAP, and BGI case definitions determined periodontal classification. Likelihood and frequency of moderate/severe periodontal disease were assessed based on demographic variables. The influence of periodontal intervention was assessed at baseline, 12, and 24 months. IL-6 was measured in a subset of subjects.

RESULTS

Of the periodontal classifications, BGI demonstrated the highest percentage category improvement with the intervention (>50%). Moderate/severe periodontitis was positively associated with HIV regardless of race, smoking status, gender, income level, and age, and was associated with increased IL-6. At baseline, the majority of subjects had severe periodontal disease regardless of ART status. Subjects with suppressed viral load at baseline demonstrated a significant improvement in BGI classification (P = 0.026), increased CD4 counts (P = 0.027), and decreased IL-6 levels (P = 0.03).

CONCLUSIONS

Periodontal inflammation was prevalent regardless of ART status. In virologically suppressed subjects, the intervention decreased periodontitis with a concomitant IL-6 decrease and CD4 increase. These findings suggest a relationship between periodontal inflammation, oral microbial translocation, and HIV status.

Increased IFN-α-producing plasmacytoid dendritic cells (pDCs) in human Th1-mediated type 1 diabetes: pDCs augment Th1 responses through IFN-α production

Increasing evidence suggests that type 1 IFN (IFN-αβ) is associated with pathogenesis of Th1-mediated type 1 diabetes (T1D). A major source of IFN-αβ is plasmacytoid dendritic cells (pDCs). In this study, we analyzed peripheral blood pDC numbers and functions in at-risk, new-onset, and established T1D patients and controls. We found that subjects at risk for T1D and new-onset and established T1D subjects possessed significantly increased pDCs but similar number of myeloid DCs when compared with controls. pDC numbers were not affected by age in T1D subjects but declined with increasing age in control subjects. It was demonstrated that IFN-α production by PBMCs stimulated with influenza viruses was significantly higher in T1D subjects than in controls, and IFN-α production was correlated with pDC numbers in PBMCs. Of interest, only T1D-associated Coxsackievirus serotype B4 but not B3 induced majority of T1D PBMCs to produce IFN-α, which was confirmed to be secreted by pDCs. Finally, in vitro studies demonstrated IFN-α produced by pDCs augmented Th1 responses, with significantly greater IFN-γ-producing CD4(+) T cells from T1D subjects. These findings indicate that increased pDCs and their IFN-αβ production may be associated with this Th1-mediated autoimmune disease, especially under certain viral infections linked to T1D pathogenesis.

Gut microbiota correlates with energy gain from dietary fibre and appears to be associated with acute and chronic intestinal diseases

Improvements in high-throughput sequencing technologies have spurred a large number of studies aimed at obtaining a better understanding of the composition and the dynamics in gut microbiota and its associations with various human diseases, especially those in the intestinal tract. Here we briefly summarize results from three different such studies from our group, all of which used 454 based high-throughput 16S rRNA sequence analysis combined with other microbiota profiling methods to determine faecal microbiota composition. In the first study, a controlled feeding trial, we establish that energy gain from the consumption of up to 50 g/day of a resistant maltodextrin depends on the prevalent microbiota composition. Over time, resistant maltodextrin supplementation increased the proportion of total faecal bacteria as well as potentially beneficial bifidobacteria. Thus, energy gain from resistant maltodextrin in an individual appears to vary over time and depend on the adaptation of gut microbiota. We then illustrate the power of molecular tools for identifying (i) distortions in early microbiota development in pre-term infants and the presence of potentially novel pathogens contributing to necrotizing enterocolitis and (ii) a specific microbiota signature, based on discriminant analysis of the 16S rRNA sequences, that correlates with the prevalence of an early risk marker associated with colorectal carcinogenesis, intestinal adenoma, in elderly adults.

Seroprevalence of herpes simplex virus 2 among Hispanics in the USA: National Health and Nutrition Examination Survey, 2007-2008

To examine the seroprevalence of herpes simplex virus type 2 (HSV-2) among Hispanics in the USA, we used the cross-sectional, nationally representative National Health and Nutrition Examination Survey to compare the seroprevalence of HSV-2 between Hispanic persons of Mexican heritage and non-Mexican heritage aged 14-44 years, from survey years 2007-2008. The overall HSV-2 seroprevalence among Hispanics aged 14-44 years was 17.5% (95% confidence interval [CI], 15.2, 20.1) in the USA. HSV-2 seroprevalence was significantly lower among Mexican Americans than among other Hispanics (11.7% vs. 27.8%, P < 0.01). Prevalence of HSV-2 was also significantly associated with gender and age. The significant difference in HSV-2 seroprevalence between Hispanic persons of Mexican heritage and non-Mexican heritage suggested that targeting specific subgroups of Hispanics for preventive interventions may be a strategy to reduce the transmission of HSV-2 and HIV among Hispanics in the USA.

Developing Miscanthus for Bioenergy

Miscanthus is a C4 perennial rhizomatous grass with origins in Eastern Asia. Several key species and their interspecific hybrids have demonstrated the potential to produce high biomass yields in a wide range of climates. Research on all aspects of Miscanthus has accelerated rapidly in the past 20 years. In this review we present the current state of knowledge on taxonomy, physiology, breeding, cultivation and environmental impact. We draw attention to many practical aspects to be considered in developing Miscanthus for bioenergy purposes including key bottlenecks that define the research themes for the future.

Upper limb corticomotor projections and physiological changes that occur with botulinum toxin-A therapy in children with hemiplegic cerebral palsy

AIM

To investigate the corticomotor projection to the upper limb in children with hemiplegic cerebral palsy (CP) and the changes that occur with botulinum toxin (BTX)-A.

METHODS

The study design is a pilot prospective randomized trial. Twenty-two children with hemiplegic CP aged 7 years to 13 years 11 months were recruited. Treatment group (12) received one series of BTX-A injections into the upper limb. Control group (10) did not receive upper limb BTX-A. All participants except one treatment group participant also received lower limb BTX-A. Transcranial magnetic stimulation (TMS) was performed at baseline, and 1, 3 and 6 months post-injection. Outcome measures were: change in position of affected and unaffected side first dorsal interosseous optimal site of stimulation (OPTx).

RESULTS

A shift in affected and unaffected side OPTx was observed for both treatment and control groups, and there was no statistically significant difference between groups at 1, 3 or 6 months. Poor tolerance of TMS cortical stimuli >80% was observed.

CONCLUSION

Corticomotor projections associated with the upper limb in children with hemiplegic CP show significant variability over a 6-month period. This variability may reflect central motor reorganization because of systemic BTX-A effect or developmental changes. Upper limb BTX-A therapy is associated with reorganization of both affected and unaffected projections. Poor tolerance of the TMS procedure, in conjunction with higher cortical thresholds, may limit the usefulness of TMS as an investigatory tool in young children with movement disorders.

The Diabetes Treatment Satisfaction Questionnaire change version (DTSQc) evaluated in insulin glargine trials shows greater responsiveness to improvements than the original DTSQ

Background

The results of using status measures to identify any changes in treatment satisfaction strongly suggest a need for specific change instruments designed to overcome the ceiling effects frequently observed at baseline. Status measures may leave little room to show improvement in situations where baseline ceiling effects are observed. A change version of the DTSQ (DTSQc) is compared here with the original status (now called DTSQs) version to test the instruments' comparative ability to demonstrate change.

Methods

Two multinational, openlabel, randomised-controlled trials (one for patients with type 1 diabetes, the other for type 2) compared new, longer-acting insulin glargine with standard NPH basal insulin. The DTSQs was completed at baseline and the DTSQs and DTSQc at final visit by 351 English- and German-speaking patients. DTSQc scores were compared with change from baseline for the DTSQs, using 3-way analysis of variance, to examine Questionnaire, Treatment and Ceiling effects (i.e. baseline scores at/near ceiling).

Results and discussion

Significant Questionnaire effects and a Questionnaire × Ceiling interaction (p < 0.001) in both trial datasets showed that the DTSQc detected more improvement in Treatment Satisfaction than the DTSQs, especially when patients had DTSQs scores at/near ceiling at baseline. Additionally, significant Treatment effects favouring insulin glargine (p < 0.001) and a Treatment × Questionnaire interaction (p < 0.019), with the DTSQc showing more benefits, were found in the type 1 trial. Results for Perceived Hyper- and Hypoglycaemia also demonstrated important differences between the questionnaires in the detection of treatment effects. Tests of effect sizes showed these differences in response to change to be significantly in favour of the DTSQc.

Conclusion

The DTSQc, used in conjunction with the DTSQs, overcomes the problem of ceiling effects encountered when only the status measure is used and provides a means for new treatments to show greater value than is possible with the DTSQs alone.

Metabolism and disposition of 1-bromopropane in rats and mice following inhalation or intravenous administration

Workplace exposure to 1-bromopropane (1-BrP) can potentially occur during its use in spray adhesives, fats, waxes, and resins. 1-BrP may be used to replace ozone depleting solvents, resulting in an increase in its annual production in the US, which currently exceeds 1 million pounds. The potential for human exposure to 1-BrP and the reports of adverse effects associated with potential occupational exposure to high levels of 1-BrP have increased the need for the development of biomarkers of exposure and an improved understanding of 1-BrP metabolism and disposition. In this study, the factors influencing the disposition and biotransformation of 1-BrP were examined in male F344 rats and B6C3F1 mice following inhalation exposure (800 ppm) or intravenous administration (5, 20, and 100 mg/kg). [1,2,3-(13)C]1-BrP and [1-(14)C]1-BrP were administered to enable characterization of urinary metabolites using NMR spectroscopy, LC-MS/MS, and HPLC coupled radiochromatography. Exhaled breath volatile organic chemicals (VOC), exhaled CO(2), urine, feces, and tissues were collected for up to 48 h post-administration for determination of radioactivity distribution. Rats and mice exhaled a majority of the administered dose as either VOC (40-72%) or (14)CO(2) (10-30%). For rats, but not mice, the percentage of the dose exhaled as VOC increased between the mid ( approximately 50%) and high ( approximately 71%) dose groups; while the percentage of the dose exhaled as (14)CO(2) decreased (19 to 10%). The molar ratio of exhaled (14)CO(2) to total released bromide, which decreased as dose increased, demonstrated that the proportion of 1-BrP metabolized via oxidation relative to pathways dependent on glutathione conjugation is inversely proportional to dose in the rat. [(14)C]1-BrP equivalents were recovered in urine (13-17%, rats; 14-23% mice), feces (<2%), or retained in the tissues and carcass (<6%) of rats and mice administered i.v. 5 to 100 mg/kg [(14)C]1-BrP. Metabolites characterized in urine of rats and mice include N-acetyl-S-propylcysteine, N-acetyl-3-(propylsulfinyl)alanine, N-acetyl-S-(2-hydroxypropyl)cysteine, 1-bromo-2-hydroxypropane-O-glucuronide, N-acetyl-S-(2-oxopropyl)cysteine, and N-acetyl-3-[(2-oxopropyl)sulfinyl]alanine. These metabolites may be formed following oxidation of 1-bromopropane to 1-bromo-2-propanol and bromoacetone and following subsequent glutathione conjugation with either of these compounds. Rats pretreated with 1-aminobenzotriazole (ABT), a potent inhibitor of P450 excreted less in urine (down 30%), exhaled as (14)CO2 (down 80%), or retained in liver (down 90%), with a concomitant increase in radioactivity expired as VOC (up 52%). Following ABT pretreatment, rat urinary metabolites were reduced in number from 10 to 1, N-acetyl-S-propylcysteine, which accounted for >90% of the total urinary radioactivity in ABT pretreated rats. Together, these data demonstrate a role for cytochrome P450 and glutathione in the dose-dependent metabolism and disposition of 1-BrP in the rat.

Efficacy and safety of endoscopic balloon dilation of symptomatic upper and lower gastrointestinal Crohn's disease strictures

GOALS

To evaluate efficacy and safety of endoscopic balloon dilation with or without intralesional steroid injection, of symptomatic upper gastrointestinal (UGI) and lower gastrointestinal (LGI) Crohn's disease (CD) strictures.

BACKGROUND

Patients with CD commonly develop obstructive symptoms secondary to gastrointestinal strictures. When these do not resolve with medical management, surgery is usually the only alternative. Limited data are available on the safety and efficacy of endoscopic through-the-scope (TTS) balloon dilation of CD strictures.

STUDY

We performed a retrospective review of TTS balloon dilations done on CD-related UGI and LGI strictures. Postdilation intralesional steroid injections were done at the discretion of the endoscopist. Stricture was defined as luminal stenosis <10 mm in diameter, through which a scope could not be passed. Technical success was defined as the ability of the scope to traverse the stricture postdilation. Long-term success rate was claimed if a patient remained asymptomatic and did not require surgery or further endoscopic dilation.

RESULTS

Over 4 years, we performed 29 stricture dilations on 17 patients (10 female, 7 male) with 20 strictures. The mean follow-up period was 18.8 months (range, 5-50 months). Stricture locations were as follows: rectal, 5; sigmoid colon, 2; colo-colonic anastomosis, 3; ileocolonic anastomosis, 4; ileum, 1; descending colon, 1; cecum, 1; and distal duodenal bulb, 3 patients. Technical success was achieved in 28 of 29 stricture dilations (96.5%). Ten strictures (34.5%) were dilated to <15 mm and 19 (65.5%) to > or = 15 mm diameter. Long-term success rate in the <15 mm group was 70%, and in > or = 15 mm group was 68.4%. Four quadrant steroid injections were done on 11 strictures. The recurrence rate in this group was 10% and that in the nonsteroid group was 31.3%. The overall long-term success rate was 76.5% by intent-to-treat analysis. Three perforations occurred (all colonic) during 29 stricture dilations, a complication rate of 10% with no mortalities.

CONCLUSION

We report the first series of TTS balloon dilations with or without intralesional steroid injection, of both primary and anastomotic UGI and LGI strictures in CD patients. Long-term success was achieved in 76.5% patients with a complication rate of 10%. This mode of therapy appears safe and effective and can be considered as an alternative to surgery in selected patients with medically refractory CD-associated GI strictures. Success rates were better in patients who received four quadrant steroid injections. No difference was seen in stricture recurrence rate or complications based on diameter of TTS balloon used.

The quantification of paracetamol, paracetamol glucuronide and paracetamol sulphate in plasma and urine using a single high-performance liquid chromatography assay

A range of analytical methods exist for the determination of paracetamol in biological fluids. However, to understand the fate of paracetamol and the effect of other drugs on its disposition in vivo, the major metabolites require quantification in urine and plasma. A method to simultaneously quantify paracetamol, paracetamol glucuronide (PG) and paracetamol sulphate (PS) in plasma and urine with superior sensitivity is therefore desired, especially if the volume of plasma available is low. A simple isocratic reverse phase high-performance liquid chromatography (HPLC) assay with spectrophotometric detection has been developed. The method, requiring only 100 microl of plasma and 50 microl of urine, utilizes a reversed-phase C18 column, a wavelength of 254 nm for detection and a mobile phase composed of potassium dihydrogen orthophosphate (0.1 M)-isopropanol-tetrahydrofuran (THF) (100:1.5:0.1, v/v/v) adjusted to pH 3.7 with phosphoric acid. The method is sensitive and linear in plasma within a concentration range from 0.4 to 200 microM for paracetamol, PG and PS. For PG and PS in urine, the method is sensitive and linear within a concentration range from 100 to 20,000 microM. Over these ranges, accuracy and precision were less than 12%. The assay has been used to measure concentrations of paracetamol and the two metabolites in plasma collected by finger-prick sampling and of the metabolites in urine from healthy volunteers administered a single oral dose of 1000 mg of paracetamol.

Integration, expression and inheritance of transgenes in hexaploid oat (Avena sativa L.)

Two oat varieties, Melys (spring variety) and Bulwark (winter variety) were transformed by particle bombardment of primary embryogenic callus using either a ubi-bar-ubi-gus co-integration vector or co-transformed (Melys) with a ubi-bar plasmid together with one of three plasmids containing the beta-glucuronidase (gus) gene under the control of either a rice actin promoter, a CaMV35S promoter or a wheat high molecular weight glutenin promoter. Morphologically normal and fertile transgenic plants were regenerated following callus selection with glufosinate ammonium. Evidence for the integration and functioning of the selectable (bar) and reporter (gus) genes in T0 and T1 plants was confirmed by PCR, Southern hybridisation, fluorescence in situ hybridisation (FISH), histochemical assays, and by progeny analysis. Transformation rates varied from 0.2 to 5.0 lines/plate of callus bombarded, with co-transformation frequencies of 83 to 100%, and co-expression frequencies of 60 to 100%. Copy numbers for the bar and gus gene varied from 3 to 17 and from 2 to 20 respectively. Cell and tissue specific expression of the gus gene was evident from the different promoters, with the HMW glutenin promoter showing endosperm specific expression in T1 seed. No expression of the gus gene under the CaMV35S promoter was detected in any tissues. Progeny analysis provided evidence of Mendelian inheritance of the introduced genes suggesting either one or two unlinked integration sites. This was confirmed by fluorescence in situ hybridisation to chromosome spread preparations. No segregation of the gus gene from the bar gene was observed in any of the progeny derived from co-transformation.

Infliximab for treatment of pyoderma gangrenosum associated with inflammatory bowel disease

OBJECTIVES

Pyoderma gangrenosum is an immune-mediated inflammatory condition characterized by ulcerative skin lesions affecting 1-2% of patients with inflammatory bowel disease (IBD). Treatment includes wound care, antibiotics, corticosteroids, and immunomodulators. However, response to therapy varies, and many patients with pyoderma gangrenosum have disease that is refractory to these agents. The aim of this study was to assess the response of medically refractory pyoderma gangrenosum to infliximab.

METHODS

This was a multicenter retrospective study of patients with IBD and medically refractory pyoderma gangrenosum treated with infliximab. Data collected included the following: baseline demographics; duration of IBD; history of bowel resection; duration of skin lesions; number, size, and location of pyoderma gangrenosum lesions; prior medications; dose and number of infliximab infusions; bowel activity before and after infliximab; pyoderma gangrenosum activity before and after infliximab therapy; time to response and time to healing of pyoderma gangrenosum lesions; recurrence of pyoderma gangrenosum after infliximab; corticosteroid taper; and adverse reactions to infliximab.

RESULTS

There were 13 patients with moderate to severe pyoderma gangrenosum and IBD treated with infliximab. All patients demonstrated complete healing of the skin lesions. Three patients had a complete response to induction infliximab therapy and did not require additional treatment. Ten patients responded to induction infliximab and have maintained pyoderma gangrenosum healing with infusions every 4-12 wk. All patients receiving corticosteroids were able to discontinue them completely after institution of infliximab treatment. Infliximab was well tolerated; the only treatment-related adverse events were sunburn in one patient and an infusion reaction in another.

CONCLUSIONS

Infliximab is a safe and effective treatment for IBD-associated pyoderma gangrenosum.

The Standardized Three-metre Walking Test for elderly people (WALK3m): repeatability and real change

OBJECTIVES

(i) To examine the relative and absolute retest within-session reliability of the Standardized Three-metre Walking Test for elderly people (WALK3m), using walking time and number of steps as measures. (ii) To give clinicians details of how they can use the minimal detectable change in order to decide whether a patient's WALK3m performance has really changed. (iii) To give rules to decide whether one trial rather than three is sufficient.

DESIGN AND ANALYSIS

Subjects made three trials of WALK3m in the same session. Variability and level of performance were related so the data were log (ln) transformed. Relative reliability was measured by the intraclass correlation coefficient (ICC) then absolute reliability by the repeatability factor (RF) and minimal detectable change (MDC) (one-tailed and two-tailed) was derived from the within-subjects standard deviation.

SETTING

Rehabilitation areas in the acute geriatric medical units at three south-west London hospitals.

SUBJECTS

The standardizing sample consisted of 81 inpatients approaching discharge to their own homes.

RESULTS

The ICC for walking time was 0.97 and for step counts 0.96. The MDC for walking is a 36% decrease between first and second measurements. The corresponding value for step counts is 21%.

CONCLUSION

WALK3m, whether measured by time or by step counts has excellent repeatability. Knowing the minimal detectable change can be of great value to clinicians who can calculate whether their patient is really making progress.

Deciding whether a change in a patient's performance is a genuine change

Our purpose is to help clinicians decide whether a measured change in a patient's performance, usually in the direction of improvement, is likely to represent a true change. We set out the calculations to derive a minimal statistically significant change in certain measures commonly used in evaluating the outcome of rehabilitation. Many of these test measurements, e.g. walking time, are likely to show increased variability within patients as the mean level of performance increases in magnitude. We pay particular attention to the calculations in this case as the data should be transformed to remove the relationship by taking their natural logarithm. Confidence interval calculations for single measurements and for differences between two measurements (using the repeatability coefficient) are given both for data that show and for data that do not show a relation between variation and level of performance.

Mutation in Brca2 stimulates error-prone homology-directed repair of DNA double-strand breaks occurring between repeated sequences

Mutation of BRCA2 causes familial early onset breast and ovarian cancer. BRCA2 has been suggested to be important for the maintenance of genome integrity and to have a role in DNA repair by homology- directed double-strand break (DSB) repair. By studying the repair of a specific induced chromosomal DSB we show that loss of Brca2 leads to a substantial increase in error-prone repair by homology-directed single-strand annealing and a reduction in DSB repair by conservative gene conversion. These data demonstrate that loss of Brca2 causes misrepair of chromosomal DSBs occurring between repeated sequences by stimulating use of an error-prone homologous recombination pathway. Furthermore, loss of Brca2 causes a large increase in genome-wide error-prone repair of both spontaneous DNA damage and mitomycin C-induced DNA cross-links at the expense of error-free repair by sister chromatid recombination. This provides insight into the mechanisms that induce genome instability in tumour cells lacking BRCA2.

The ascertainment and management of tuberculosis in Tayside, Scotland during 1993-94

OBJECTIVE

To evaluate whether utilising a database of dispensed prescriptions for anti-tuberculous chemotherapy could improve case ascertainment compared to standard methods. A further objective was to assess whether cases were managed according to standard guidelines.

DESIGN

Retrospective case note audit.

SETTING

Tayside, Scotland

SUBJECTS

Patients identified by conventional (i.e. SMRI diagnostic codes, notifications to the Health Board, microbiology and pathology reports) and the data base (MEMO) as potentially having tuberculosis and receiving treatment between 1st January 1993 and 31st December 1994. One hundred and ninety one potential cases were identified. One hundred and twenty two case notes were obtained for review. Eighty eight of these were initially thought to have tuberculosis and the results below refer to these 88 cases.

RESULTS

MEMO identified 43 cases not found by conventional methods. Cases identified by MEMO were more likely to have been managed as outpatients and less likely to have positive microbiology than cases identified by conventional means. Only 26 cases were notified to the Health Board, including all smear positive cases.

CONCLUSIONS

Notification of tuberculosis continues to be incomplete. Use of the MEMO system almost doubled case ascertainment. The absence of a firm diagnosis may lead to a reluctance to notify cases being treated as tuberculosis.

Gestational exposure to cocaine or pharmacologically related compounds: effects on behavior and striatal dopamine receptors

Gestational cocaine (COC) exposure has been reported to alter behavior and possibly dopamine (DA) receptors. In this paper, we further examined the effects of prenatal COC (40 mg/kg, s.c.) on DA receptor binding and the behavioral response to quinpirole, a DA D2 receptor agonist. In an attempt to elucidate possible mechanisms of such effects, we exposed pregnant dams to specific reuptake blockers; fluoxetine 12.5 mg/kg, a serotonin reuptake blocker; desipramine 10 mg/kg, a norepinephrine reuptake blocker; GBR-12909 10 mg/kg, a DA reuptake blocker; or to a local anesthetic, lidocaine 40 mg/kg. Drugs were administered once daily over gestational days 8-20. Control dams were injected with saline (SAL) or pair-fed to the COC group. Quinpirole challenge was performed in the offspring on post natal day 19. Two pups per litter were injected (s.c.) with 0.03 or 0.09 mg/kg quinpirole-HCl on post-natal day 19. The remaining pups in each litter were sacrificed for analysis of striatal DA receptors. Results showed that only COC exposure altered the behavioral response to the quinpirole challenge by increasing quinpirole-induced stereotypy and motor activity relative to SAL controls. DA receptor analysis showed no alteration in K(D) or B(MAX) for striatal D1 or D2 sites in any group. These results suggest that prenatal COC exposure produces alterations in function of the D2 receptor complex which are not reflected in K(D) or B(MAX) and that these effects are not fully mimicked by exposure to specific monoamine reuptake blockers or a local anesthetic.

Syphilis outbreak assessment

BACKGROUND

Syphilis rates began to decline in 1991 and have decreased every year since. In 1998, 6,993 cases of primary and secondary syphilis were reported in the United States, for a national incidence of 2.6 cases per 100,000 population. Although syphilis rates are at an historic low, focal outbreaks still occur. On October 7, 1999, the Division of Sexually Transmitted Disease Prevention of the Centers for Disease Control and Prevention, in collaboration with federal and community partners, presented the National Plan for Elimination of Syphilis from the United States. One of the five key strategies of the plan is rapid outbreak response.

METHODS

Methods for outbreak assessment and response were reviewed in the literature, synthesized, and adapted for use in syphilis outbreaks.

RESULTS

Key elements of outbreak assessment and response are detection, surveillance data review, hypothesis generation, intervention development, and the evaluation of clinical, public health, and laboratory services.

CONCLUSIONS

Outbreak response necessitates community participation and a coordinated interdisciplinary effort to determine social and behavioral contributors to the outbreak and to develop targeted interventions.

Incidental splenic injury during abdominal vascular surgery: a case-controlled analysis

BACKGROUND

The small but finite risk of postsplenectomy sepsis is generally regarded as a firm indication for splenic preservation after iatrogenic injury, especially in the young. But splenectomy may be preferable in patients who sustain splenic injuries during vascular operations because of the potential for continued bleeding associated with anticoagulation. The purpose of this study was to determine the perioperative morbidity of incidental splenectomy among patients undergoing abdominal vascular operations.

STUDY DESIGN

We studied 17 patients who underwent incidental splenectomy at the time of abdominal vascular operations. Complete data collected on each subject included preoperative and postoperative blood counts, operative indications and details, transfusion requirements, length of hospital stay, and outcomes. Using age- and gender-matched case controls undergoing identical vascular operations from the same period, we evaluated the complication rate and outcomes of patients who underwent splenectomy for iatrogenic injuries of the spleen, versus those who did not sustain splenic injuries.

RESULTS

The estimated prevalence of iatrogenic splenic injury during the study period was 0.5%. Mean operative time, estimated blood loss, and duration of mechanical ventilation tended to be greater in the splenectomy patients, but the differences did not achieve statistical significance. Splenorrhaphy was attempted in seven patients, but continued bleeding mandated spleen removal in all cases. Splenectomy patients had a higher transfusion requirement (p = 0.03) and a longer mean length of stay (p = 0.03) than controls. Compared with controls, there was a higher prevalence of infectious complications in the splenectomy patients (p = 0.015), but there was no difference in the prevalence of thromboembolic complications between groups. Two of the splenectomy patients died in the postoperative period from multisystem organ failure, and one died of a missed splenic injury.

CONCLUSIONS

These data suggest that incidental splenectomy during abdominal vascular operations is associated with increased postoperative infectious complications and prolonged hospitalization.

Managerialism and active citizenship in Britain's reformed health service: power and community in an era of decentralisation

The creation of a large managerial stratum within the British National Health Service in recent years has been one of the most striking characteristics of reforms intended to develop a more efficient and "business-like" service. An accompanying political rhetoric of decentralisation has cast local managerial autonomy as a means to gauge and respond more easily to the needs and preferences expressed by local communities. This article therefore reviews the growth of the new managerial stratum with particular regard to its emerging relationship with the local populations in whose name the organisational reforms have been wrought. The dominant political interpretation of this relationship--that the organisational reforms constitute a movement from leaden "bureaucratic" administration to more locally accountable and responsive managerial regimes--is then tested with regard to an in-depth study of two health authorities responsible for very different local populations. Results show that the role of local populations in influencing decisions and determining priorities is considerably less than inferred by the sustained political rhetoric in favour of the "local voices". Consideration of possible trends in the state and economy suggests however that this disjuncture may not be explicable solely in terms of the new managerial stratum maximising its influence or of central government retaining a high degree of control.

Predictive model of weapon carrying among urban high school students: results and validation

OBJECTIVES

The purpose of this study was to identify the behavioral, psychosocial, and demographic predictors of self-reported weapon carrying among secondary school students who attend urban public schools.

METHODS

Self-reported weapon carrying was measured in a schoolwide anonymous health survey conducted in two demographically comparable high schools in 1992, in Boston, Massachusetts. Indicators of self-perception, depression, stressful life events, and adolescent risk behaviors of substance use and sexual behavior, along with self-reported weapon carrying, were measured. The students in both schools were racially heterogeneous, with the majority of about 80% from black or Hispanic backgrounds. A predictive model was developed using a forward stepwise logistic regression model in one inner-city high school, and tested in a second high school.

RESULTS

Self-reported lifetime weapon carrying was 32% overall. The major predictors of weapon carrying among urban secondary school students are a combination of demographic, psychosocial, behavioral, and school-related factors. This analysis indicates consistency in eight markers predictive of weapon carrying: lower age, male gender, regular marijuana use, sexual experience, having witnessed a crime, having skipped school, suicidal ideation, and having hit or "beat up" someone. Race parental education, and family composition were not significant predictors. Significant predictors of weapon carrying were marijuana use and sexual experience, each of which was consistently high in both schools.

CONCLUSIONS

The model-building and validation presented in this study provide empirical evidence for three important conclusions. First, weapon carrying is associated with multiple and interrelated factors which include demographic, psychosocial, behavioral, and school-related characteristics of high school-age adolescents. Second, students with more risk factors are more likely to carry a weapon, suggesting that the variables are independent markers. Third, this study identified marijuana use and being sexually experienced as both highly predictive of weapon carrying. Implications of this study for prevention point to the need for comprehensive multidisciplinary services in high school that include mental health counseling as well as health education efforts aimed at behavior change.

Imaging soft X-rays with opaque spheres

Images of small fluorescence X-ray sources obtained by diffraction with opaque spheres were recorded with a flow-proportional counter and on X-ray sensitive film. Image fluxes and intensities obtained experimentally were compared with theoretical estimates made using analytical expressions derived from the sphere's point-source imaging properties.

Expressed sequences from conidial, mycelial, and sexual stages of Neurospora crassa

In the Neurospora Genome Project at the University of New Mexico, expressed sequence tags (ESTs) corresponding to three stages of the life cycle of the filamentous fungus Neurospora crassa are being analyzed. The results of a pilot project to identify expressed genes and determine their patterns of expression are presented. 1,865 partial complementary DNA (cDNA) sequences for 1,409 clones were determined using single-pass sequencing. Contig analysis allowed the identification of 838 unique ESTs and 156 ESTs present in multiple cDNA clones. For about 34% of the sequences, highly or moderately significant matches to sequences (of known and unknown function) in the NCBI database were detected. Approximately 56% of the ESTs showed no similarity to previously identified genes. Among genes with assigned function, about 43.3% were involved in metabolism, 32.9% in protein synthesis and 8.4% in RNA synthesis. Fewer were involved in defense (6%), cell signalling (3.4%), cell structure (3.4%) and cell division (2.6%).

Increase of manganese superoxide dismutase, but not of Cu/Zn-SOD, in experimental optic neuritis

PURPOSE

To evaluate the role of manganese superoxide dismutase (Mn-SOD) and copper/zinc superoxide dismutase (Cu/Zn-SOD) in cellular protection of the optic nerve against the oxidative injury that contributes to demyelination in experimental allergic encephalomyelitis (EAE).

METHODS

Immunocytochemistry for Mn-SOD and Cu/Zn-SOD and ultracytochemical localization of hydrogen peroxide (H2O2) were performed on the optic nerves of guinea pigs with EAE and normal guinea pigs. Cell-specific enzyme expression of SOD was quantitated by computerized morphometric analysis.

RESULTS

Light microscopy showed a perivascular distribution of Mn-SOD-positive cells in the optic nerves of animals with EAE. Electron microscopy showed that the Mn-SOD immunogold was confined exclusively to mitochondria, whereas Cu/Zn-SOD immunogold was found in the cytoplasmic matrix and nucleus of cells of the optic nerve in both animals with EAE and normal animals. Results of quantitative analysis of the optic nerves of animals with EAE showed an 8-fold increase in Mn-SOD immunogold in astroglial cells and a 13-fold increase in microglial/phagocytic cells in comparison with that of normal animals. Increases in Mn-SOD immunogold were contiguous to H2O2-derived reaction product. No increases in Cu/Zn-SOD immunogold were detected in EAE.

CONCLUSIONS

Increases in Mn-SOD activity in astroglial cells and microglial/phagocytic cells may contribute to the relative sparing of these cells from injury in EAE, whereas the low level of Mn-SOD in oligodendroglial cells and axons may increase their vulnerability to the effects of superoxide-induced oxidative injury that results in demyelination.

Thyroid function in a population of children with attention deficit hyperactivity disorder

OBJECTIVE

To determine the prevalence of thyroid hormone abnormalities and generalized resistance to thyroid hormone in a population of children with attention deficit hyperactivity disorder (ADHD) as compared to reference ranges determined from a control population and hence to determine if routine thyroid hormone screening in children with non-familial ADHD is indicated.

METHOD

Children attending the State Child Development Centre in Perth, Western Australia with ADHD, as defined by the Diagnostic and Statistical Manual of Mental Disorders (fourth edition) provided the study population. The control population consisted of 353 normal children with a history of allergy in whom radioallergosorbent (RAST) testing was being performed.

RESULTS

The prevalence of thyroid hormone abnormalities in the study population was 2.3% (95% CI 0.6%, 5.7%). There were no cases of generalized resistance to thyroid hormone. The prevalence of thyroid hormone abnormalities in the general population of children and adolescents has been reported to vary between 1 and 3.7%.

CONCLUSION

Routine thyroid hormone screening is not indicated in children with non-familial ADHD.