Fusobacterium nucleatum persistence and risk of recurrence after preoperative treatment in locally advanced rectal cancer

BACKGROUND

Accumulating evidence has identified Fusobacterium as an important pathogenic gut bacterium associated with colorectal cancer. Nevertheless, only limited data exist about the role of this bacterium in locally advanced rectal cancer (LARC). In this study, we quantified Fusobacterium nucleatum in untreated and post-neoadjuvant chemoradiotherapy (nCRT) samples from LARC patients and investigated its association with therapy response and survival.

PATIENTS AND METHODS

A total of 254 samples from 143 patients with rectal adenocarcinomas were analyzed for the presence and abundance of F. nucleatum using RNA in situ hybridization and digital image analysis. Assay accuracy was determined using infected cell lines and tumor samples with available quantitative PCR data. We studied the impact of F. nucleatum load on pathologic complete response and relapse-free survival. Treatment-induced changes were evaluated in paired pre- and post-nCRT samples (n = 71). Finally, tumor microenvironment changes during nCRT were assessed in paired samples (n = 45) by immune contexture analysis.

RESULTS

F. nucleatum tissue levels by RNA in situ hybridization strongly correlated with quantitative PCR (r = 0.804, P < 0.001). F. nucleatum abundance was higher in untreated [median, 7.4; 95% confidence interval (3.7-16.2)] compared with treated [median, 1.6; 95% confidence interval (1.3-2.4)] tumors (P <0.001) with 58% (73/126) and 26% (22/85) positive tumors, respectively (P < 0.001). Baseline F. nucleatum levels were not associated with pathologic complete response. F. nucleatum positivity after nCRT, but not baseline status, significantly increased risk of relapse [hazard ratio = 7.5, 95% confidence interval (3.0-19.0); P < 0.001]. Tumors that turned F. nucleatum-negative after nCRT had a strong increase in CD8+ T cells post-nCRT (P < 0.001), while those that persisted F. nucleatum-positive after nCRT lacked CD8+ T cells induction in post-nCRT samples compared with baseline (P = 0.69).

CONCLUSION

F. nucleatum persistence post-nCRT is associated with high relapse rates in LARC, potentially linked to suppression of immune cytotoxicity.

Development of nalidixic acid amphotericin B vancomycin (NAV) medium for the isolation of Campylobacter ureolyticus from the stools of patients presenting with acute gastroenteritis

Recently, Campylobacter ureolyticus has been detected for the first time in the faeces of patients with acute gastroenteritis using polymerase chain reaction (PCR) techniques. Cultural isolation of C. ureolyticusis is not possible using the established selective methods for the isolation of thermophilic Campylobacter spp. from faeces. The aim of the current study is to develop a new selective medium capable of isolating C. ureolyticus from faecal samples. The newly-developed medium consists of Anaerobe Basal Agar with 10 g/L additional agar, 2 g/L sodium formate and 3 g/L sodium fumarate dibasic, to which 10 mg/L nalidixic acid, 10 mg/L amphotericin B and 20 mg/L vancomycin (NAV) are added as selective agents. Validation studies have shown that this experimental selective medium completely inhibits growth of Candida spp. and of Enterococcus spp. and permits reduced growth of selected coliforms and Proteus spp. Growth of Campylobacter ureolyticus on NAV medium is optimal in anaerobic and enriched hydrogen atmospheres. Additionally, an overnight enrichment step using Bolton broth to which 2 g/L sodium formate, 3 g/L sodium fumarate dibasic and the NAV supplement are added, in place of the commercial Bolton broth supplement, allows improved recovery of C. ureolyticus from patients' faeces.

Factors affecting client response to HIV outreach efforts

PURPOSE

This article describes 12 HIV Outreach Demonstration Projects funded by the Center for Substance Abuse Treatment in 1995, and the clients these projects served. The article also summarizes the findings of multivariate statistical analyses aimed at identifying important project and client characteristics that influenced project success in achieving two key outcomes: persuading at-risk clients to obtain HIV tests, and facilitating entry by substance-abusing clients into structured substance abuse treatment (SAT).

METHODS

Hierarchical linear modeling (HLM) analysis was used to conduct the analyses.

RESULTS

The findings support the hypothesis that HIV Outreach, as an integrated approach to addressing the multiple problems clients have due to substance abuse and related problems, can be an effective model for reaching clients who have not been reached through traditional means.

IMPLICATIONS

By implementing a complement of comprehensive HIV Outreach interventions, many of the HIV Outreach projects were successful in addressing the various needs of their clients. However, as detailed in this article, some services and service delivery procedures, were more effective than others in achieving project objectives.

Effects of daily dermal application of DEET and epermethrin, alone and in combination, on sensorimotor performance, blood-brain barrier, and blood-testis barrier in rats

DEET and permethrin were implicated in the development of illnesses in some veterans of the Persian Gulf War. This study was designed to investigate the effects of daily dermal application of these chemicals, alone or in combination, on the permeability of the blood-brain barrier (BBB) and blood-testes barrier (BTB) and on sensorimotor performance in male Sprague-Dawley rats. Groups of five rats were treated with a dermal daily dose of 4, 40, or 400 mg/kg DEET in ethanol or 0.013, 0.13, or 1.3 mg/kg permethrin in ethanol for 60 d. A group of 10 rats received a daily dermal dose of ethanol and served as controls. BBB permeability was assessed by injection of an iv dose of the quaternary ammonium compound [3H]hexamethonium iodide. While permethrin produced no effect on BBB permeability, DEET alone caused a decrease in BBB permeability in brainstem. A combination of DEET and permethrin significantly decreased the BBB permeability in the cortex. BTB permeability was decreased by treatment with DEET alone and in combination with permethrin. The same animals underwent a battery of functional behavior tests 30, 45, and 60 d after exposure to evaluate their sensorimotor abilities. All treatments caused a significant decline in sensorimotor performance in a dose- and time-dependent manner. These results show that daily dermal exposure to DEET, alone or in combination with permethrin, decreased BBB permeability in certain brain regions, and impaired sensorimotor performance.

Expression of the apolipoprotein E gene does not affect motor recovery after sensorimotor cortex injury in the mouse

Motor recovery after unilateral sensorimotor cortex ablation or sham-injury was measured in apolipoprotein E knockout and wild-type mice by testing their abilities to traverse a narrow beam. All mice trained without difficulty. Sham-operated mice performed perfectly regardless of genotype throughout testing. There was no difference in motor scores between lesioned apolipoprotein E knockout and wild-type mice on a first trial 24h after injury (P>0.05). There was a significant overall effect of lesion on motor performance (two-way repeated measures analysis of variance F(1,42)=304, P<0.0001), a significant time effect (F(17,714)=58, P<0.0001) and a lesion by time interaction (F(17,714)=58, P<0.0001). However, there was no effect of apolipoprotein E genotype group on recovery rate (i.e. there was no lesion group by genotype group by time interaction, F(17,714)=0.33, P=1.00) and no effect of genotype on the final level of motor performance 12 days after the lesion (Kruskal-Wallis H=5.79, P=0.12). These data suggest that motor recovery after unilateral injury to the sensorimotor cortex does not vary with apolipoprotein E genotype.

HIV outreach for hard-to-reach populations: a cross-site perspective

This article examines the effectiveness of outreach as a vehicle for moving hard-to-reach substance abusing clients into substance abuse treatment. These clients were recruited by and participated in one of twelve HIV Outreach Demonstration Projects funded by the Center for Substance Abuse Treatment (CSAT). The analysis combines data across projects to provide a cross-site perspective. Data from 1675 clients were analyzed in this study. In addition, a comparison group of 3704 subjects was generated from the National Treatment Improvement Evaluation Study (NTIES) data. The results supported the hypothesis that clients representing traditional hard-to-reach populations would be more likely to enter treatment for substance abuse through participation in HIV Outreach programs than would clients exposed to treatment-specific recruiting methods (e.g. NTIES). The findings from this cross-site study support the view that HIV Outreach, as an integrated approach to several behavioral constellations, is more effective in recruiting clients to substance abuse treatment than are approaches that focus exclusively on substance abusing behavior. The HIV Outreach model is especially effective in reaching substance abusers earlier in the cycle of abuse. This has importance clinically for developing and focusing more effective methods for treatment for younger substance abusers with shorter histories of abuse. It also has implications for policy to guide the effective use of scarce treatment resources. Targeting specific populations and affiliation with substance abuse treatment providers were also influential in facilitating access to substance abuse treatment for groups at increased risk for HIV.

Effect of food on the pharmacokinetics of ropinirole in parkinsonian patients

AIMS

Ropinirole is a specific non-ergoline dopamine D2-receptor agonist with antiparkinsonian properties. The pharmacokinetic parameters of ropinirole taken in the fasted condition were compared with those when it was co-administered with food.

METHODS

This was an open, randomized, two sessions cross over study in 12 patients with Parkinson's disease, comparing the steady-state pharmacokinetic profiles of ropinirole on two different study days: 'fasted' and 'fed'.

RESULTS

The mean Cmax was lower in the 'fed' regimen than in the 'fasted' one (-25%, P=0.002). The median tmax was observed 2.6 h later in the 'fed' regimen than in the 'fasted' regimen (P<0.05). There was a slight but significant decrease in AUC(0,8 h) in the 'fed' regimen (P=0.03).

CONCLUSIONS

Food decreases the rate of absorption of ropinirole, but has little effect on the extent of absorption.

Effects of dorsal noradrenergic bundle lesions on recovery after sensorimotor cortex injury

Several lines of evidence suggest that the recovery of the ability of rats to traverse a narrow beam after unilateral injury to the sensorimotor cortex is noradrenergically mediated. We tested the hypotheses that the influence of norepinephrine on beam-walking recovery occurs, at least partially, through effects in the contralateral and/or ipsilateral cerebral cortex. Rats had either a selective left or right 6-hydroxydopamine lesion or sham lesion of the dorsal noradrenergic bundle (DNB) 2 weeks before suction-ablation or sham injury of the right sensorimotor cortex. The rats' abilities to perform the beam-walking task were measured over the 10 days following cortex surgery. DNB lesions did not affect the initial severity of the beam-walking deficit and had no effect on the performance of the task in rats with sham cortex injuries. Lesions of the contralateral but not ipsilateral DNB significantly impaired recovery. Further, in cortically lesioned rats with contralateral DNB lesions, norepinephrine content in the cerebral cortex opposite to the sensorimotor cortex lesion was significantly correlated with recovery. These data suggest that the effect of norepinephrine on recovery of beam-walking ability may be partially exerted in the cerebral cortex contralateral to the injury.