Brachytherapy for high grade prostate cancer induces distinct changes in circulating CD4 and CD8 T cells - Implications for systemic control

This exploratory study is a follow up to our previous investigation of immune response in the circulation of high-grade Gleason 9 prostate cancer patients treated with EBRT + BT compared to EBRT alone. Notably, EBRT + BT demonstrates the potential to elicit an effect on CD4/CD8 ratio which may have attributed to improved clinical response to therapy. Our findings show promise for leveraging circulating immune cells as predictive biomarkers for radiotherapy response.

Characterization of length of stay after minimally invasive endoscopic intracerebral hemorrhage evacuation

BACKGROUND

Minimally invasive evacuation may help ameliorate outcomes after intracerebral hemorrhage (ICH). However, hospital length of stay (LOS) post-evacuation is often long and costly.

OBJECTIVE

To examine factors associated with LOS in a large cohort of patients who underwent minimally invasive endoscopic evacuation.

METHODS

Patients presenting to a large health system with spontaneous supratentorial ICH qualified for minimally invasive endoscopic evacuation if they met the following inclusion criteria: age ≥18, premorbid modified Rankin Scale (mRS) score ≤3, hematoma volume ≥15 mL, and presenting National Institutes of Health Stroke Scale (NIHSS) score ≥6. Demographic, clinical, radiographic, and operative characteristics were included in a multivariate logistic regression for hospital and ICU LOS dichotomized into short and prolonged stay at 14 and 7 days, respectively.

RESULTS

Among 226 patients who underwent minimally invasive endoscopic evacuation, the median intensive care unit and hospital LOS were 8 (4-15) days and 16 (9-27) days, respectively. A greater extent of functional impairment on presentation (OR per NIHSS point 1.10 (95% CI 1.04 to 1.17), P=0.007), concurrent intraventricular hemorrhage (OR=2.46 (1.25 to 4.86), P=0.02), and deep origin (OR=per point 2.42 (1.21 to 4.83), P=0.01) were associated with prolonged hospital LOS. A longer delay from ictus to evacuation (OR per hour 1.02 (1.01 to 1.04), P=0.007) and longer procedure time (OR per hour 1.91 (1.26 to 2.89), P=0.002) were associated with prolonged ICU LOS. Prolonged hospital and ICU LOS were in turn longitudinally associated with a lower rate of discharge to acute rehabilitation (40% vs 70%, P<0.0001) and worse 6-month mRS outcomes (5 (4-6) vs 3 (2-4), P<0.0001).

CONCLUSIONS

We present factors associated with prolonged LOS, which in turn was associated with poor long-term outcomes. Factors associated with LOS may help to inform patient and clinician expectations of recovery, guide protocols for clinical trials, and select suitable populations for minimally invasive endoscopic evacuation.

Effects of trauma history on cancer-related screening, diagnosis, and treatment

Trauma has substantial effects on human health and is recognised as a potential barrier to seeking or receiving cancer care. The evidence that exists regarding the effect of trauma on seeking cancer screening, diagnosis, and treatment and the gaps therein can define this emerging research area and guide the development of interventions intended to improve the cancer care continuum for trauma survivors. This Review summarises current literature on the effects of trauma history on screening, diagnosis, and treatment among adult patients at risk for or diagnosed with cancer. We discuss a complex relationship between trauma history and seeking cancer-related services, the nature of which is influenced by the necessity of care, perceived or measured health status, and potential triggers associated with the similarity of cancer care to the original trauma. Collaborative scientific investigations by multidisciplinary teams are needed to generate further clinical evidence and develop mitigation strategies to provide trauma-informed cancer care for this patient population.

Initial experience with minimally invasive endoscopic evacuation of intracerebral hemorrhage in the setting of radiographic herniation

BACKGROUND

Spontaneous intracerebral hemorrhage (ICH) can rapidly result in cerebral herniation, leading to poor neurologic outcomes or mortality. To date, neither decompressive hemicraniectomy (DH) nor hematoma evacuation have been conclusively shown to improve outcomes for comatose ICH patients presenting with cerebral herniation, with these patients largely excluded from clinical trials. Here we present the outcomes of a series of patients presenting with ICH and radiographic herniation who underwent emergent minimally invasive (MIS) ICH evacuation.

METHODS

We reviewed our prospectively collected registry of patients undergoing MIS ICH evacuation at a single institution from 01/01/2017 to 10/01/2021. We selected all consecutive patients with Glasgow coma scale (GCS) ≤ 8 and radiographic herniation for this case series. Clinical and radiographic variables were collected, including admission GCS score, preoperative and postoperative hematoma volumes, National Institute of Health stroke scale (NIHSS) scores, and modified Rankin scale (mRS) scores at last follow-up.

RESULTS

Of 176 patients with spontaneous supratentorial ICH who underwent minimally invasive endoscopic evacuation during the study time period, a total of 9 patients presented with GCS ≤ 8 and evidence of radiographic herniation. Among these patients, the mean age was 62 ± 12 years, the median GCS at presentation was 5 [IQR 4-6], the mean preoperative hematoma volume was 94 ± 44 mL, the mean time from ictus to evacuation was 12 ± 5 h, and the mean postoperative hematoma volume was 11 ± 16 mL, for a median evacuation percentage of 97% [83-99]. Three patients (33%) died, four (44%) survived with mRS 5 and two (22%) with mRS 4. Patients had a median NIHSS improvement of 5 compared to their initial NIHSS. Age was very strongly correlate to improvements in NIHSS (r2 = 0.90).

CONCLUSION

Data from this initial experience suggest emergent MIS hematoma evacuation in the setting of ICH with radiographic herniation is feasible and technically effective. Further randomized studies are required to determine if such an intervention offers overall benefits to patients and their families.

Dysphagia after ischemic and hemorrhagic stroke: A propensity-matched 20-year analysis of the national inpatient sample

OBJECTIVE

Dysphagia is a common symptom of acute ischemic stroke (AIS) and intracerebral hemorrhage (ICH), but little is known surrounding national trends of this post-stroke condition. Hence, this study aimed to identify the risk factors for dysphagia following AIS and ICH and evaluate in-hospital outcomes in these patients.

METHODS

The 2000-2019 Nationwide Inpatient Sample was queried for patients admitted with AIS (ICD9 433, 43401, 43411, 43491, ICD-10 I63) and ICH (ICD9 431, 432.9, ICD-10 I61, I62.9). Univariate analysis with t-tests or chi-square performed as appropriate. A 1:1 nearest neighbor propensity score matched cohort was generated. Variables with standardized mean differences >0.1 were used in multivariable regression to generate adjusted odds ratios (AOR)/β-coefficients for the presence of dysphagia on outcomes.

RESULTS

Of 10,415,286 patients with AIS, 956,662 (9.2%) had in-hospital dysphagia. Total of 2,000,868 patients with ICH were identified; 203,511 (10.2%) had in-hospital dysphagia. Patients with dysphagia after AIS were less likely to experience in-hospital mortality (OR 0.61;95%CI: 0.60-0.63) or be discharged home (AOR 0.51;95%CI: 0.51-0.52), had increased length of stay (Beta-coefficient = 0.43 days; 95%CI: 0.36-0.50), and had increased hospital charges ($14411.96;95%CI: 13565.68-15257.44) (all p < 0.001). Patients with dysphagia after ICH were less likely to experience in-hospital mortality (AOR 0.39;95%CI: 0.37-0.4), less likely to be discharged home (AOR 0.59,95%CI:0.57-0.61), have longer hospital stay (Beta-coefficient = 1.99 days;95%CI: 1.78-2.21), and increased hospital charges ($28251.93; 95%CI: $25594.57-30909.28)(all p < 0.001).

CONCLUSION

This is the first study to report on national trends in patients with dysphagia after AIS and ICH. These patients had longer hospital LOS, worse functional outcomes at discharge, and higher hospital costs.

Early and effective intracerebral hemorrhage evacuation is associated with a lower 1-year residual cavity volume and better functional outcomes

BACKGROUND

We explored the clinical significance of the residual hematoma cavity 1 year after minimally invasive intracerebral hemorrhage (ICH) evacuation.

METHODS

Patients presenting with spontaneous supratentorial ICH were evaluated for minimally invasive surgical evacuation. Inclusion criteria included age ≥18 years, preoperative hematoma volume (Hv) ≥15 mL, presenting National Institutes of Health Stroke Scale score ≥6, and premorbid modified Rankin Scale (mRS) score ≤3. Patients with longitudinal CT scans at least 3 months after evacuation were included in the study. Remnant cavity volumes (Cv) after evacuation were computed using semi-automatic volumetric segmentation software. Relative cavity volume (rCv) was defined as the ratio of the preoperative Hv to the remnant Cv.

RESULTS

108 patients with a total of 484 head CT scans were included in the study. The median postoperative Cv was 2.4 (IQR 0.0-11) mL, or just 6% (0-33%) of the preoperative Hv. The median residual Cv on the final head CT scan a median of 13 months (range 11-27 months) after surgery had increased to 9.4 (IQR 3.1-18) mL, or 25% (10-60%) of the preoperative Hv. rCv on the final head CT scan was negatively associated with measures of operative success including evacuation percentage, postoperative Hv ≤15 mL, and decreased time from ictus to evacuation. rCv on the final head CT scan was also associated with a worse 6-month functional outcome (β per mRS point 17.6%, P<0.0001; area under the receiver operating characteristic curve 0.91).

CONCLUSION

After minimally invasive ICH evacuation the hematoma lesion decompresses significantly, with a residual Cv just 6% of the original lesion, but then gradually increases in size over time. Early and high percentage ICH evacuation may reduce the remnant Cv over time which, in turn, is associated with improved functional outcomes.

The Effect of Multiple Scopus Profiles on the Perceived Academic Productivity of Neurosurgeons in the United States

OBJECTIVE

Bibliometrics assessing academic productivity plays a significant role in neurosurgeons' career advancement. This study aimed to evaluate the influence of multiple author profiles on Scopus on neurosurgeon author-level metrics (h-index, document number, citation number).

METHODS

A list of 1671 academic neurosurgeons was compiled through public searches of hospital and faculty websites for 115 neurosurgical residency training programs. The h-index, document number, and citation number for each neurosurgeon were collected using the Scopus algorithm. For surgeons with multiple profiles, total document number and citation number were calculated by summing results of each profile. Cumulative h-indices were calculated manually. Comparisons were made between surgeons with a single Scopus profile and surgeons with multiple profiles.

RESULTS

A total of 124 neurosurgeons with multiple profiles were identified. Gender distribution (P = 0.47), years in practice (P = 0.06), subspecialty (P = 0.32), and academic rank (P = 0.16) between neurosurgeons with a single profile versus multiple profiles were similar. Primary profile h-index median was 16 (interquartile range [IQR]: 8-34), combined profiles median was 20 (IQR: 11-36), and percent loss median was 17.3% (IQR: 3%-33%) (P < 0.001). For document number, primary profile median was 46 (IQR: 16-127), combined profiles median was 55 (IQR: 22-148), and percent loss median was 16.2% (IQR: 7%-36%) (P < 0.001). For citation number, primary profile median was 1030 (IQR: 333-4082), combined profiles median was 1319 (IQR: 546-4439), and percent loss median was 14.1% (IQR: 4%-32%) (P < 0.001).

CONCLUSIONS

U.S. academic neurosurgeons with multiple existing profiles on Scopus experience a 17.3% loss in h-index, a 16.2% loss in document number, and a 14.1% loss in citations, heavily undercounting their perceived academic productivity.

Abstract TMP56: Trends In Alcohol Abuse In Patients With Acute Ischemic Stroke: A 20-year Analysis Of The Nationwide Inpatient Sample

Introduction: Heavy alcohol (EtOH) consumption has been long recognized for its damaging effects to the brain and is considered a risk factor for stroke. However, the relationship between EtOH abuse and stroke on in-hospital outcomes remains unclear.

Objective: To characterize stroke patients with an EtOH abuse and examine the effects of alcohol abuse on patient outcomes over 20 years.

Methods: A query of the 2000-2019 National Inpatient Sample was performed for patients admitted with AIS (ICD9 433, 43401, 43411, 43491, ICD-10 I63). Demographics, comorbidities, and outcomes were identified. Univariate analysis with t-tests or chi-square performed as appropriate. A 1:1 nearest neighbor propensity score matched cohort was generated. Variables with standardized mean differences >0.1 used in multivariate regression to generate adjusted odds ratios (AOR)/β-coefficients for EtOH abuse on outcomes. Significance set at an alpha level of <0.001. All analysis performed in R version 4.1.3.

Results: A total of 10,415,286 patients with AIS were identified; 368,953 (3.5%) abused EtOH. EtOH abuse patients had higher Elixhauser Comorbidity Score (11.02 ± 10.38 vs. 9.72 ± 8.76; p<0.001) and NIH Stroke Score (7.19 ± 7.08 vs. 6.65 ± 7.30; p<0.001). Patients with EtOH abuse were more likely to be male, younger, smokers, covered on Medicaid, have atrial fibrillation, and be in the 0-25% percentile median income bracket (all p<0.001). After propensity matching, EtOH abuse patients had longer hospital stay (0.39 days; 95% CI: 0.28-0.5), lower hospital charges (-$3780.6; 95% CI: -$5053.16 - -$2508.04) and were less likely to be discharged home or short-term hospital (AOR 0.83; 95% CI: 0.81-0.85)(all p<0.001).

Conclusion: In this 20 year nationally representative propensity matched analysis of patients with AIS, patients that abused EtOH had higher incidences of more severe disease with worse functional outcomes, as well as lower hospital charges despite longer hospital stays.

An Exploration of Sleep and Family Factors in Young Children at Familial Risk for ADHD

Objective: The aim of the current study was to examine relations between sleep problems and family factors and early markers of ADHD in young children with and without a familial risk for ADHD.Methods: Differences in sleep behavior and family functioning in children under 6 years with (n = 72) and without (n = 139) a familial risk for ADHD were investigated. The influence of family and sleep factors on the development of early temperament markers of ADHD (effortful control and negative affect) was explored. Parents/caregivers completed questionnaires on family functioning, child sleep behavior, and general regulatory behaviors.Results: A significant difference was observed between high-risk and low-risk groups for family functioning in the infant/toddler (<3 years) and preschool (>3 years) cohorts. Parents of infants/toddlers in the high-risk group reported poorer infant sleep. However, there were no sleep differences reported for the preschool cohort. Family functioning was found to predict effortful control, while sleep quality predicted negative affect.Conclusion: The results of this study highlight potential family and sleep issues for young children with a familial history of ADHD and the potential influence of these factors on early temperament markers of ADHD. Future research should explore these relations further in order to better establish whether early sleep and family interventions could mitigate later ADHD symptomatology.

Sensory modulation and negative affect in children at familial risk of ADHD

BACKGROUND/AIMS

Sensory modulation difficulties are commonly reported in patients with ADHD, however there has been little focus on the development of these difficulties in young children at a higher risk of later ADHD diagnosis. This study investigated whether children with a familial history of ADHD show greater sensory modulation difficulties. We also explored whether sensory modulation was linked to negative affectivity, which has been highlighted as a potential early marker of ADHD.

METHODS

Parents of children under 6 years with a family history of ADHD (n = 65) and no family history (n = 122) completed questionnaires on sensory modulation and temperament.

RESULTS

Children from families with ADHD were reported to display extreme patterns of hyperresponsiveness and hyporesponsiveness, relative to controls. No differences emerged for the sensory seeking domain. Some children within the high-risk group reported high scores across all three sensory modulation patterns. Regression analysis revealed that hyperresponsiveness predicted higher levels of negative affect.

CONCLUSIONS/IMPLICATIONS

This study is the first to report greater sensory modulation difficulties in children at familial risk of ADHD. Future research should establish whether children with sensory modulation and temperament difficulties in early childhood are more vulnerable to developing ADHD.

Executive function in children with sickle cell anemia on transfusion: NIH toolbox utility in the clinical context

OBJECTIVE

The aim of this study was to establish the utility of the NIH Toolbox as a cognitive screener of executive functions in the clinical context. Additionally, we aimed to investigate whether age and time on transfusion were related to executive function performance. Method: Twenty-eight children and adolescents with sickle cell anemia (SCA) between 8 and 18 years (M = 13.28, SD = 3.05) on transfusion treatment were included. Participants completed five NIH Toolbox tasks (three executive function tasks and two non-executive function control tasks). Results: Mean scores on one of the three executive function measures (inhibitory control) fell below the average range (M = 81.36, SD = 14.01) with approximately 70% of children from both groups below the average range. Scores for processing speed (M = 86.82, SD = 22.01) and cognitive flexibility (M = 85.75, SD = 12.67) were low averages. As expected, scores on non-executive measures (language and memory) fell within the average range. No significant differences were observed between children with silent stroke and no stroke on executive function measures. Older age (p < .01) and length of time on transfusion (p < .05) predicted lower inhibitory control scores. Conclusions: Findings provide evidence for poor development of inhibitory control with age in this patient population. As the NIH Toolbox successfully highlighted expected deficits in this patient population, this study supports the use of this tool as a brief screening measure for children with SCD. The clinical and theoretical implications of the findings are discussed.

Nuclear receptors and AMPK: resetting metabolism

Obesity, and in particular central adiposity, is a key feature of metabolic syndrome, which includes trends toward increased triglycerides, insulin resistance, high blood pressure, hypercholesterolemia, and heart disease. It has a prevalence of 25% or more and is a dominant component of the health care budgets in Western societies. In addition to genetic causes, high-fat diets and disrupted sleep patterns have major influences on the development of metabolic syndrome. Recent studies have demonstrated active roles for the nuclear receptor superfamily and the energy-sensing kinase adenosine monophosphate (AMP)-activated protein kinase (AMPK) in regulating metabolism and circadian rhythm. In this chapter, we review these findings and attempt to develop a better understanding of the interplay between metabolism and circadian rhythm and their coordinated regulation by nuclear receptors and AMPK. This supraregulatory network may be considered a target for novel therapeutic applications against metabolic syndrome.

Detecting soluble clusterin in in-vitro and in-vivo models of prostate cancer

PSA, the only relevant marker for prostate cancer, has a low predictive value; moreover its low threshold leads to unnecessary biopsies with associated complications. Identification of prognostic factors is an important goal in prostate cancer. In the search for new markers, clusterin, has some potential as it is closely linked with cancer progression and resistance to apoptosis. We looked at the expression of secreted clusterin (sCLU) in prostate cells to determine correlations with progression and drug resistance. The plasmatic expression of sCLU was also investigated in order to use it as a potential marker for prostate cancer. sCLU expression was studied using Western blotting on cultured prostate cells, PWR-1E, PC3 and PC3 Docetaxel resistant cells in the cytosol and culture medium. An inhouse ELISA test was developed to determine sCLU expression in culture media and plasma samples. A patient cohort was identified from the Prostate Cancer Research Consortium Bio-Resource and plasmatic expression of sCLU was studied using western blotting and the inhouse ELISA test. Only the fully processed form of sCLU was identified in the medium of cells with increased expression associated with increased progression of disease and resistance to docetaxel. Plasmatic expression of sCLU was significantly higher in the plasma of patients with high grade prostate cancer with extracapsular extension than in the plasma of prostate cancer patients without extracapsular extension. Plasmatic sCLU may be an effective prognostic marker of prostate cancer and needs to be tested in a multimarker approach.

One year clinical outcomes of renal artery stenting: the results of ODORI Registry

The safety, efficacy and long term clinical benefits of renal artery revascularization by stenting are still a matter of debate. The aim of our study was to define the safety and efficacy of renal artery stenting with the Tsunami peripheral stent (Terumo Corporation, Tokyo, Japan). The ODORI was a prospective, multicentre registry which enrolled 251 consecutive patients, (276 renal arteries) in 36 centres across Europe. The primary endpoint was acute procedural success defined as <30% residual stenosis after stent placement. Secondary endpoints included major adverse events, blood pressure control, serum creatinine level, and target lesion revascularization (TLR) at 6 and 12 months. Patients were 70 +/- 10 years old, 59% were male, 33% had diabetes, and 96% hypertension. The main indications for renal stent implantation were hypertension in 83% and renal salvage in 39%. Direct stent implantation was performed in 76% of the cases. Acute success rate was 100% with residual stenosis of 2.5 +/- 5.4%. Systolic/diastolic blood pressure decreased from a mean of 171/89 at baseline to 142/78 mmHg at 6 months (p < 0.0001 vs. baseline), and 141/80 mmHg at 12 months (p < 0.0001 vs. baseline). Mean serum creatinine concentration did not change significantly in the total population. However, there was significant improvement in the highest tercile (from 283 micromol/l at baseline to 205 and 209 micromol/l at 6 and 12 months respectively). At 12-months, rates of restenosis and TLR were 6.6 and 0.8% respectively. The 12 month cumulative rate of all major clinical adverse events was 6.4% while the rate of device or procedure related events was 2.4%. In hypertensive patients with atherosclerotic renal artery stenosis Tsunami peripheral balloon-expandable stent provides a safe revascularization strategy, with a potential beneficial impact on hypertension control and renal function in the highest risk patients.

Should vascular surgeons be trained in endovascular techniques? An observational study

INTRODUCTION

The aim of this study was to determine if there is a satisfactory cover for interventional radiology and whether vascular surgeons have received sufficient training in endovascular techniques.

MATERIALS AND METHODS

This was an observational study based on questionnaires sent to radiology and vascular trainers and vascular trainees in England. A total of 50 NHS trusts were chosen randomly to take part in the study and 320 questionnaires were sent out with an overall consultant response rate of 57%.

RESULTS

Of vascular consultants in the study group, 53% have had experience in endovascular procedures. Overall, 87% felt that there were not enough radiologists to fulfil the demand and 64% would like further training in endovascular procedures. In addition, 69% would like to be involved in a vascular rota without the general component. Similarly, 81% of radiologists felt that the demand was not being met, as emergency interventional radiology cover was not available on most nights in 65% of the trusts. Of responders, 72% would not object to training of vascular trainees in interventional work and 43% would be happy to be involved in training. Some 33% would accept a vascular trainee for 1 year.

CONCLUSIONS

Integrated fellowship in vascular surgery and interventional radiology has been implemented and tested in a number of centres in the US. This approach could be implemented in some of the larger vascular units in the UK.

Pancreas transplantation in Ireland

BACKGROUND

We report on our experience of pancreatic transplants performed in Beaumont Hospital from 1992 to January 2003. During this period, 63 pancreatic transplants were carried out. Simultaneous pancreas and kidney transplantation is regarded as the treatment of choice for Type 1 diabetics with end stage renal failure (ESRF) by the American Diabetes Association.

METHODS

A retrospective review of all the pancreas transplants between 1992 and January 2003 was carried out. All of the patients had insulin-dependent diabetes mellitus (IDDM) and, in addition, 57 of the recipients had concomitant end stage renal failure. For two of the patients, this was a second transplant, one of them having had a previous renal graft which thrombosed. The second patient underwent a simultaneous pancreas and kidney (SPK) transplant in 1998 with loss of the pancreatic graft shortly afterwards. She subsequently received a pancreas only transplant in 2002.

RESULTS

The follow-up period ranges from one month to ten years and parameters used to assess graft function include Hb A1c and serum creatnine (SPK only). There have been 22 graft losses (six kidneys, nine pancreases and seven involving both the kidney and pancreas), to date. The one-year graft survival was 80.4% (pancreas) and 92.7% (kidney), with a one-year patient survival of 94.8%, which compares favourably with figures from other centres. At follow-up, the average Hb A1c at six months post-transplant was 5.7% with a serum creatnine of 121micmol/L being recorded at one month.

CONCLUSION

Our experience of pancreas transplants at Beaumont Hospital has been very encouraging with graft and patient survival equivalent to other international centres.

A pilot study of adjuvant intraperitoneal 5-fluorouracil using 4% icodextrin as a novel carrier solution

AIM

This pilot study utilised the sustained intraperitoneal (i.p.) dwell properties of an iso-osmotic solution of 4% icodextrin to investigate the tolerability, toxicity and feasibility of home-based i.p. 5FU adjuvant chemotherapy following resective surgery for colorectal cancer.

METHODS

Twenty eligible patients (Dukes' stage B and C with potentially curative resection) underwent perioperative Tenckhoff catheter placement. Ten (6 male, 4 female, aged 46-85; mean 67.5 years) received 5FU chemotherapy. After initial flushing and gradual increase in volumes of 4% icodextrin alone, patients received home-based i.p. 5FU (150-300 mg/m(2)/day given as equal doses at 12-hourly intervals) for 14 days, with a 14-day recovery period, for a maximum of 6 courses. Two incurable patients, treated on compassionate grounds, provided further safety data.

RESULTS

Nine of the 10 patients became proficient in self-treatment with 5FU and two completed 6 courses. Frequent abdominal pain was the main dose-limiting toxicity of 5FU, causing withdrawal of three patients after a high (300 mg/m(2)/day) first course and one following a third course at lower doses. I.p. 5FU concentrations (mean>30000 ngml(-1)) were 1000 fold higher than systemic venous levels. Bacterial peritonitis led to two withdrawals but was not a frequent event (microbiologically confirmed incidence of 1 per 27 catheter-months).

CONCLUSIONS

Home-based i.p. adjuvant chemotherapy is a feasible treatment option in patients with surgically resected colorectal carcinoma.

SOX18 and the transcriptional regulation of blood vessel development

SOX18 is a transcription factor that is transiently expressed in nascent endothelial cells during embryonic development and adult neovascularization. This protein belongs to the SOX family of transcription factors, which are proving to be some of the key regulators of cell-type specification in the vertebrate embryo. Natural mutations in the Sox18 gene have been shown to result in cardiovascular dysfunction, in some cases leading to death. Available evidence thus implicates Sox18 as an important regulator of vascular development, most likely playing a key role in endothelial cell specification. However, the genetic knockout of Sox18 in mice has produced a confounding result that complicates our understanding of the molecular mode of action of the SOX18 protein. We speculate that Sox18 may act in a redundant fashion with closely related genes such as Sox7 and/or Sox17.

Virus-directed, enzyme prodrug therapy with nitroimidazole reductase: a phase I and pharmacokinetic study of its prodrug, CB1954

CB1954 [5-(aziridin-1-yl)-2,4-dinitrobenzamide] is converted by the bacterial enzyme nitroimidazole reductase (NTR) into a potent cytotoxic bifunctional alkylating agent, which can be delivered to tumors in adenoviral vectors as virus-directed, enzyme prodrug therapy. This report summarizes a Phase I and pharmacokinetic study of the prodrug, CB1954. Thirty patients, ages 23-78 years (median 62 years), with predominantly gastrointestinal malignancies were treated. CB1954 was administered by i.v. injection every 3 weeks or i.p. followed by 3-weekly i.v. injections, toward a maximum of six cycles. The dose was escalated from 3 to 37.5 mg/m2. No significant toxicity was seen until 24 mg/m2 (recommended i.v. dose). Dose-limiting toxicities (DLT) were diarrhea and hepatic toxicity, seen at 37.5 mg/m2. DLT has not been observed at the current i.p. dose of 24 mg/m2. There was no alopecia, marrow suppression, or nephrotoxicity. Clearance data suggest hepatic metabolism, and <5% of CB1954 was renally excreted. There was a nonlinear relationship between i.v. dose and area under the curve (AUC). At the recommended i.v. dose of 24 mg/m2, the AUC was 5.8 microM/h. Intraperitoneal administration (24 mg/m2) achieved an AUC of 387 microM/h, giving a considerable regional advantage. In vitro, the AUC required to achieve the IC50 for CB1954, in NTR-expressing cancer cells, ranges from 10-50 microM/h. Thus, CB1954 is well tolerated at a dose of 24 mg/m2, and sufficient serum/peritoneal levels are achieved for an enzyme-prodrug approach to be feasible. We are now conducting a Phase I trial combining adenovirus-mediated NTR and i.v. CB1954 (24 mg/m2) in patients with primary and secondary liver tumors.

Active repression of RAR signaling is required for head formation

The retinoic acid receptors (RARs) recruit coactivator and corepressor proteins to activate or repress the transcription of target genes depending on the presence of retinoic acid (RA). Despite a detailed molecular understanding of how corepressor complexes function, there is no in vivo evidence to support a necessary function for RAR-mediated repression. Signaling through RARs is required for patterning along the anteroposterior (A-P) axis, particularly in the hindbrain and posterior, although the absence of RA is required for correct anterior patterning. Because RARs and corepressors are present in regions in which RA is absent, we hypothesized that repression mediated through unliganded RARs might be important for anterior patterning. To test this hypothesis, specific reagents were used that either reduce or augment RAR-mediated repression. Derepression of RAR signaling by expressing a dominant-negative corepressor resulted in embryos that exhibited phenotypes similar to those treated by RA. Anterior structures such as forebrain and cement gland were greatly reduced, as was the expression of molecular markers. Enhancement of target gene repression using an RAR inverse agonist resulted in up-regulation of anterior neural markers and expansion of anterior structures. Morpholino antisense oligonucleotide-mediated RARalpha loss-of-function phenocopied the effects of RA treatment and dominant-negative corepressor expression. Microinjection of wild-type or dominant-negative RARalpha rescued the morpholino phenotype, confirming that RAR is functioning anteriorly as a transcriptional repressor. Lastly, increasing RAR-mediated repression potentiated head-inducing activity of the growth factor inhibitor cerberus, whereas releasing RAR-mediated repression blocked cerberus from inducing ectopic heads. We conclude that RAR-mediated repression of target genes is critical for head formation. This requirement establishes an important biological role for active repression of target genes by nuclear hormone receptors and illustrates a novel function for RARs during vertebrate development.

A dynamic role for HDAC7 in MEF2-mediated muscle differentiation

The overlapping expression profile of MEF2 and the class-II histone deacetylase, HDAC7, led us to investigate the functional interaction and relationship between these regulatory proteins. HDAC7 expression inhibits the activity of MEF2 (-A, -C, and -D), and in contrast MyoD and Myogenin activities are not affected. Glutathione S-transferase pulldown and immunoprecipitation demonstrate that the repression mechanism involves direct interactions between MEF2 proteins and HDAC7 and is associated with the ability of MEF2 to interact with the N-terminal 121 amino acids of HDAC7 that encode repression domain 1. The MADS domain of MEF2 mediates the direct interaction of MEF2 with HDAC7. MEF2 inhibition by HDAC7 is dependent on the N-terminal repression domain and surprisingly does not involve the C-terminal deacetylase domain. HDAC7 interacts with CtBP and other class-I and -II HDACs suggesting that silencing of MEF2 activity involves corepressor recruitment. Furthermore, we show that induction of muscle differentiation by serum withdrawal leads to the translocation of HDAC7 from the nucleus into the cytoplasm. This work demonstrates that HDAC7 regulates the function of MEF2 proteins and suggests that this class-II HDAC regulates this important transcriptional (and pathophysiological) target in heart and muscle tissue. The nucleocytoplasmic trafficking of HDAC7 and other class-II HDACs during myogenesis provides an ideal mechanism for the regulation of HDAC targets during mammalian development and differentiation.

Sharp, an inducible cofactor that integrates nuclear receptor repression and activation

A yeast two-hybrid screen using the conserved carboxyl terminus of the nuclear receptor corepressor SMRT as a bait led to the isolation of a novel human gene termed SHARP (SMRT/HDAC1 Associated Repressor Protein). SHARP is a potent transcriptional repressor whose repression domain (RD) interacts directly with SMRT and at least five members of the NuRD complex including HDAC1 and HDAC2. In addition, SHARP binds to the steroid receptor RNA coactivator SRA via an intrinsic RNA binding domain and suppresses SRA-potentiated steroid receptor transcription activity. Accordingly, SHARP has the capacity to modulate both liganded and nonliganded nuclear receptors. Surprisingly, the expression of SHARP is itself steroid inducible, suggesting a simple feedback mechanism for attenuation of the hormonal response.

Identification of a nuclear domain with deacetylase activity

Here, we describe the identification and characterization of a nuclear body (matrix-associated deacetylase body) whose formation and integrity depend on deacetylase activity. Typically, there are 20-40 0.5-microM bodies per nucleus, although the size and number can vary substantially. The structure appears to contain both class I and the recently described class II histone deacetylases (HDAC)5 and 7 along with the nuclear receptor corepressors SMRT (silencing mediator for retinoid and thyroid receptor) and N-CoR (nuclear receptor corepressor). Addition of the deacetylase inhibitors trichostatin A and sodium butyrate completely disrupt these nuclear bodies, providing a demonstration that the integrity of a nuclear body is enzyme dependent. We demonstrate that HDAC5 and 7 can associate with at least 12 distinct proteins, including several members of the NuRD and Sin3A repression complexes, and appear to define a new but related complex.

Humanized xenobiotic response in mice expressing nuclear receptor SXR

The cytochrome CYP3A gene products, expressed in mammalian liver, are essential for the metabolism of lipophilic substrates, including endogenous steroid hormones and prescription drugs. CYP3A enzymes are extremely versatile and are inducible by many of their natural and xenobiotic substrates. Consequently, they form the molecular basis for many clinical drug-drug interactions. The induction of CYP3A enzymes is species-specific, and we have postulated that it involves one or more cellular factors, or receptor-like xeno-sensors. Here we identify one such factor unequivocally as the nuclear receptor pregnenolone X receptor (PXR) and its human homologue, steroid and xenobiotic receptor (SXR). We show that targeted disruption of the mouse PXR gene abolishes induction of CYP3A by prototypic inducers such as dexamethasone or pregnenolone-16alpha-carbonitrile. In transgenic mice, an activated form of SXR causes constitutive upregulation of CYP3A gene expression and enhanced protection against toxic xenobiotic compounds. Furthermore, we show that the species origin of the receptor, rather than the promoter structure of CYP3A genes, dictates the species-specific pattern of CYP3A inducibility. Thus, we can generate 'humanized' transgenic mice that are responsive to human-specific inducers such as the antibiotic rifampicin. We conclude that SXR/PXR genes encode the primary species-specific xeno-sensors that mediate the adaptive hepatic response, and may represent the critical biochemical mechanism of human xenoprotection.

Structure-function analysis of the Rev-erbA and RVR ligand-binding domains reveals a large hydrophobic surface that mediates corepressor binding and a ligand cavity occupied by side chains

Rev-erbA/RVR are closely related orphan nuclear receptors (NRs) functioning as dominant transcriptional silencers through an association with the nuclear receptor corepressor N-CoR. In contrast with ligand-regulated NRs, Rev-erbA/RVR lack the ligand-binding domain (LBD) C-terminal activation helix, H12. In the case of retinoid acid receptor and thyroid hormone receptor, ligand binding is thought to reposition H12, causing corepressor dissociation and coactivator recruitment, thus leading to transcriptional activation. Here we present homology models of the Rev-erbA/RVR LBDs, which show that the putative ligand cavity is occupied by side chains, suggesting the absence of endogenous ligands. Modeling also revealed a very hydrophobic surface due to the absence of H12, exposing residues from H3, loop 3-4, H4, and H11. Mutation of specific residues from this surface severely impaired the in vitro and in vivo interaction of the Rev-erbA/RVR LBD with the receptor-interacting domain of the corepressors N-CoR or its splice variant RIP13delta1, reinforcing the view of the physical association of N-CoR with a LBD surface encompassing H3-H4 and H11. Furthermore, mutations in the LBD surface significantly reduced the ability of Rev-erbA and RVR to function as repressors of transcription. Interestingly, a hydrophobic surface comprised of H3-H4 and H12 in liganded NRs mediates the interaction with coactivators. Hence, it appears that corepressors and coactivators bind to overlapping surfaces of NR LBDs, the conformational change associated with H12 upon ligand binding resulting in a switch from a corepressor- to a coactivator-binding surface.

The genome sequence of Drosophila melanogaster

The fly Drosophila melanogaster is one of the most intensively studied organisms in biology and serves as a model system for the investigation of many developmental and cellular processes common to higher eukaryotes, including humans. We have determined the nucleotide sequence of nearly all of the approximately 120-megabase euchromatic portion of the Drosophila genome using a whole-genome shotgun sequencing strategy supported by extensive clone-based sequence and a high-quality bacterial artificial chromosome physical map. Efforts are under way to close the remaining gaps; however, the sequence is of sufficient accuracy and contiguity to be declared substantially complete and to support an initial analysis of genome structure and preliminary gene annotation and interpretation. The genome encodes approximately 13,600 genes, somewhat fewer than the smaller Caenorhabditis elegans genome, but with comparable functional diversity.

Isolation of a novel histone deacetylase reveals that class I and class II deacetylases promote SMRT-mediated repression

The transcriptional corepressor SMRT functions by mediating the repressive effect of transcription factors involved in diverse signaling pathways. The mechanism by which SMRT represses basal transcription has been proposed to involve the indirect recruitment of histone deacetylase HDAC1 via the adaptor mSin3A. In contrast to this model, a two-hybrid screen on SMRT-interacting proteins resulted in the isolation of the recently described HDAC5 and a new family member termed HDAC7. Molecular and biochemical results indicate that this interaction is direct and in vivo evidence colocalizes SMRT, mHDAC5, and mHDAC7 to a distinct nuclear compartment. Surprisingly, HDAC7 can interact with mSin3A in yeast and in mammalian cells, suggesting association of multiple repression complexes. Taken together, our results provide the first evidence that SMRT-mediated repression is promoted by class I and class II histone deacetylases and that SMRT can recruit class II histone deacetylases in a mSin3A-independent fashion.

Partitioning effects during terminal carbon and electron flow in sediments of a low-salinity meltwater pond near Bratina Island, McMurdo Ice Shelf, Antarctica

A study of anaerobic sediments below cyanobacterial mats of a low-salinity meltwater pond called Orange Pond on the McMurdo Ice Shelf at temperatures simulating those in the summer season (<5 degrees C) revealed that both sulfate reduction and methane production were important terminal anaerobic processes. Addition of [2-(14)C]acetate to sediment samples resulted in the passage of label mainly to CO(2). Acetate addition (0 to 27 mM) had little effect on methanogenesis (a 1.1-fold increase), and while the rate of acetate dissimilation was greater than the rate of methane production (6.4 nmol cm(-3) h(-1) compared to 2.5 to 6 nmol cm(-3) h(-1)), the portion of methane production attributed to acetate cleavage was <2%. Substantial increases in the methane production rate were observed with H(2) (2.4-fold), and H(2) uptake was totally accounted for by methane production under physiological conditions. Formate also stimulated methane production (twofold), presumably through H(2) release mediated through hydrogen lyase. Addition of sulfate up to 50-fold the natural levels in the sediment (interstitial concentration, approximately 0.3 mM) did not substantially inhibit methanogenesis, but the process was inhibited by 50-fold chloride (36 mM). No net rate of methane oxidation was observed when sediments were incubated anaerobically, and denitrification rates were substantially lower than rates for sulfate reduction and methanogenesis. The results indicate that carbon flow from acetate is coupled mainly to sulfate reduction and that methane is largely generated from H(2) and CO(2) where chloride, but not sulfate, has a modulating role. Rates of methanogenesis at in situ temperatures were four- to fivefold less than maximal rates found at 20 degrees C.

A patient preference study comparing raltitrexed ('Tomudex') and bolus or infusional 5-fluorouracil regimens in advanced colorectal cancer: influence of side-effects and administration attributes

Current chemotherapy regimens used in advanced colorectal cancer (ACRC) are similar in terms of efficacy, but differ importantly in terms of side-effects and administration profiles. These differences may impact significantly on patients' lives. We have evaluated patient preferences between raltitrexed ('Tomudex') and 5-fluorouracil-based chemotherapy regimens, with regard to side-effect attributes (raltitrexed and Mayo regimens) and administration attributes (raltitrexed, Mayo, De Gramont and Lokich regimens) in a study based on 82 patients with ACRC. Patients completed a series of rating tasks on how 'upsetting' these attributes were to them using a visual analogue scale (VAS) in a structured interview conducted by a research nurse. Mucositis and asthenia were the most and least upsetting side-effects, respectively. The side-effect profile of raltitrexed was clearly preferred by 78% of patients versus 14% for Mayo (P < 0.001). When side-effects and administration attributes were combined into an overall profile, 91% of patients selected raltitrexed as their clearly preferred regimen, versus 6% for Mayo (P < 0.001). The administration regimen of raltitrexed was ranked most acceptable (mean rank score 1.5 compared with Mayo 2.6, De Gramont 2.7, and Lokich 3.3). Given similar palliative effects, patients with ACRC exhibit preferences for raltitrexed over other regimens, based on administration and/or side-effect attributes. Such preferences should constitute an important part of decisions relating to the choice of chemotherapy regimen in ACRC.

The nuclear receptor corepressor N-CoR regulates differentiation: N-CoR directly interacts with MyoD

Classical ligand-activated nuclear receptors (e.g. thyroid hormone receptor, retinoic acid receptor), orphan nuclear receptors (e.g. Rev-erbAalpha/beta), Mad/Max bHLH (basic helix loop helix)-LZ proteins, and oncoproteins, PLZF and LAZ3/BCL6, bind DNA and silence transcription by recruiting a repressor complex that contains N-CoR (nuclear receptor corepressor)/SMRT (silencing mediator of retinoic acid and thyroid hormone receptor), Sin3A/B, and HDAc-1/-2 proteins. The function of the corepressor, N-CoR, in the process of cellular differentiation and coupled phenotypic acquisition, has not been investigated. We examined the functional role of N-CoR in myogenesis (muscle differentiation), an ideal paradigm for the analysis of the determinative events that govern the cell's decision to divide or differentiate. We observed that the mRNA encoding N-CoR was suppressed as proliferating myoblasts exited the cell cycle, and formed morphologically and biochemically differentiated myotubes. Exogenous expression of N-CoR (but not RIP13) in myogenic cells ablated 1) myogenic differentiation, 2) the expression of the myoD gene family that encode the myogenic specific bHLH proteins, and 3) the crucial cell cycle regulator, p21Waf-1/Cip-1 mRNA. Furthermore, N-CoR expression efficiently inhibits the myoD-mediated myogenic conversion of pluripotential C3H10T1/2 cells. We demonstrate that MyoD-mediated transactivation and activity are repressed by N-CoR. The mechanism involves direct interactions between MyoD and N-CoR; moreover, the interaction was dependent on the amino-terminal repression domain (RD1) of N-CoR and the bHLH region of MyoD. Trichostatin A treatment significantly stimulated the activity of MyoD by approximately 10-fold and inhibited the ability of N-CoR to repress MyoD-mediated transactivation, consistent with the involvement of the corepressor and the recruitment of a histone deacteylase activity in the process. This work demonstrates that the corepressor N-CoR is a key regulator of MyoD activity and mammalian differentiation, and that N-CoR has a multifaceted role in myogenesis.

Unique forms of human and mouse nuclear receptor corepressor SMRT

Nuclear hormone receptors have been shown to repress transcription in the absence of ligand. This repression is mediated by a corepressor complex that contains the Sin3A protein and histone deacetylases (HDAC1 and 2). Studies by several groups demonstrate that this complex is recruited to nuclear receptors through the highly related corepressors SMRT (silencing mediator of retinoid acid and thyroid hormone receptor) and N-CoR (nuclear receptor corepressor). We describe here the cloning, characterization, and chromosomal mapping of forms of human and mouse SMRT that includes a 1,000-aa extension, which reveals striking homology to the amino terminus of N-CoR. Structure and function studies of wild-type and natural splicing variants suggest the presence of 3-4 amino terminal domains that repress in a cooperative as well as mechanistically distinct fashion.

A histone deacetylase corepressor complex regulates the Notch signal transduction pathway

The Delta-Notch signal transduction pathway has widespread roles in animal development in which it appears to control cell fate. CBF1/RBP-Jkappa, the mammalian homolog of Drosophila Suppressor of Hairless [Su(H)], switches from a transcriptional repressor to an activator upon Notch activation. The mechanism whereby Notch regulates this switch is not clear. In this report we show that prior to induction CBF1/RBP-Jkappa interacts with a corepressor complex containing SMRT (silencing mediator of retinoid and thyroid hormone receptors) and the histone deacetylase HDAC-1. This complex binds via the CBF1 repression domain, and mutants defective in repression fail to interact with the complex. Activation by Notch disrupts the formation of the repressor complex, thus establishing a molecular basis for the Notch switch. Finally, ESR-1, a Xenopus gene activated by Notch and X-Su(H), is induced in animal caps treated with TSA, an inhibitor of HDAC-1. The functional role for the SMRT/HDAC-1 complex in CBF1/RBP-Jkappa regulation reveals a novel genetic switch in which extracellular ligands control the status of critical nuclear cofactor complexes.

The corepressor N-CoR and its variants RIP13a and RIP13Delta1 directly interact with the basal transcription factors TFIIB, TAFII32 and TAFII70

Repression of transcription by the classical nuclear receptors (e.g. TR, RAR), the orphan nuclear receptors (e.g. Rev-erbAalpha/beta), Mxi-1 and Mad bHLH-zip proteins and the oncoproteins PLZF and LAZ3/BCL6 is mediated by the corepressors N-CoR and SMRT. The interaction of the corepressors with the components involved in chromatin remodelling, such as the recruiting proteins Sin3A/B and the histone deacteylases HDAc-1 and RPD3, has been analysed in detail. The N-CoR/Sin3/HDAc complexes have a key role in the regulation of cellular proliferation and differentiation. However, the interaction of these corepressors with the basal transcriptional machinery has remained obscure. In this study we demonstrated that the N-terminalrepression domains and the receptor interactiondomains (RID) of N-CoR and its splice variants, RIP13a and RIP13Delta1, directly interact with TAFII32 in vivo and in vitro . We show that interaction domain II within the N-CoR and RIP13a RID is required for the interaction with TAFII32. We also observed that N-CoR directly interacts with each of the basal factors, TFIIB and TAFII70, and can simultaneously interact with all three basal factors in a non-competitive manner. Furthermore, we provide evidence that suggests the RVR/Rev-erbbeta-corepressor complex also interacts with the general transcriptional machinery, and that the physicalassociation of TFIIB with N-CoR also occurs in the presence of Sin3B and HDAc-1. Interestingly, we observed that N-CoR expression ablated the functional interaction between TFIIB and TAFII32 that is critical to the initiation of transcription. In conclusion, this study demonstrates that the N-terminal repressor region and the C-terminal RIDs are part of the corepressor contact interface that mediates the interaction with the general transcription factors, and demonstrates that TAFs can also directly interact with corepressors to mediate signals from repressors to the basal machinery. We also suggest that N-CoR interacts with the central components of the transcriptional initiation process (TFIIB, TAFs) and locks them into a non-functional complex or conformation that is not conducive to transcription.