Intramuscular recurrence in a hepatocellular carcinoma patient with indolent disease course

Background

Hepatocellular carcinoma (HCC) is a common malignancy worldwide and treatment options are depended on the stage of the tumour. In general, the prognosis of HCC patients with extra-hepatic metastasis is poor. The most common sites of extra-hepatic metastasis are the lung, abdominal lymph nodes and bone.

Case presentation

Here, we reported a 54-year-old man with an indolent clinical course of HCC. He had multiple extra-hepatic recurrences after initial hepatectomy for HCC and was benefited from repeated resections with prolonged survival. Eventually, he developed intramuscular recurrence in the thigh, which was initially mistaken as deep vein thrombosis.

Conclusion

Selected patients with indolent disease course of HCC may benefit from repeated resections of extra-hepatic metastases with prolonged survival.

Promoter hypermethylation of FANCF and outcome in advanced ovarian cancer

The Fanconi gene family has a role in DNA repair and inactivation of FANCF has been proposed as a mechanism of sensitisation to platinum chemotherapy. This study sought to confirm this hypothesis in cell lines and a large series of ovarian cancer samples. Promoter methylation was assessed by methylation-sensitive polymerase chain reaction of FANCF in nine ovarian cancer cell lines and 74 ovarian cancer samples taken from patients entered on a trial of cisplatin-based chemotherapy. This study confirmed methylation-dependent silencing of FANCF in one out of nine ovarian cancer cell lines. Methylation of FANCF was demonstrated in 13.2% of 53 evaluable ovarian tumour samples. Progression-free survival gave an HR of 3.63 (95% CI: 1.54–8.54, P=0.0016) in favour of the unmethylated cases. There was no association with overall survival. This study does not support methylation-dependent silencing of FANCF as a mechanism of sensitisation to platinum-based chemotherapy in ovarian cancer.

Efficacy and tolerability of low-dose thalidomide as first-line systemic treatment of patients with advanced hepatocellular carcinoma

OBJECTIVE

The systemic treatment of advanced hepatocellular carcinoma (HCC) has produced disappointing results thus far. HCC is a hypervascular tumor with over-expression of angiogenic factors such as vascular endothelial growth factor. Thalidomide is an anti-neoplastic agent with anti-angiogenic and other mechanisms of action. We aim to evaluate the efficacy and toxicity of low-dose (100 mg) thalidomide as the first-line treatment of advanced HCC.

METHODS

Between August 2003 and March 2007, 45 patients who had received thalidomide 100 mg daily as first-line treatment of advanced HCC were reviewed retrospectively. Advanced HCC was defined as either metastatic or not amenable to surgical or locoregional therapies. Diagnosis of HCC was based on clinical, biochemical and radiological grounds. Survival was analyzed by the Kaplan-Meier method.

RESULTS

Thirty-eight patients were evaluable for response and toxicity. Two (5%) patients had partial response and 8 (21%) had stable disease. The overall median survival of patients in this cohort was 3.2 months (95% CI: 2.8-3.7 months). The common toxicities were somnolence (13%), peripheral neuropathy (11%) and ankle edema (8%), with no grade 3 or 4 toxicities and treatment-related deaths.

CONCLUSION

Our study shows that a single agent, low-dose thalidomide has a modest clinical activity with good tolerability in treating advanced HCC patients.

High Dose Rate Brachytherapy as a Boost after Preoperative Chemoradiotherapy for More Advanced Rectal Tumours — the Clatterbridge Experience

In a systemic review of 8507 patients from 22 randomised trials, radiotherapy has been shown to reduce the risk of local recurrence and death from rectal cancer compared with surgery alone. Recent large randomised trials confirmed that chemoradiotherapy was better than radiotherapy alone. Contact radiotherapy as a boost after external beam radiotherapy (without chemotherapy) has also been shown to improve local control and sphincter preservation in the Lyon 092 trial. Brachytherapy has now been used as preoperative treatment for rectal cancer and showed similar results. The Swedish and Dutch trial results of short-course preoperative radiotherapy have shown improved local control in favour of the radiotherapy group. Similar to the Scandinavian group, investigators from McGill University in Montreal adopted a short course using brachytherapy instead of external beam radiotherapy. However, surgery was delayed for 4-8 weeks to achieve downstaging. The radiation dose was delivered directly on to the tumour and the surrounding normal tissues were spared the effects of radiation. This approach has been shown to reduce the side-effects seen with external beam short-course radiotherapy, but maintains the benefit of improved local control. The Danish group used brachytherapy as a boost after external beam chemoradiotherapy for more advanced rectal tumours and have shown improved pathological complete remission and R0 resection rates. The Mount Vernon group used a similar rectal applicator for inoperable rectal cancer patients and achieved good local and symptom control. The brachytherapy group at Clatterbridge used the same approach as the Danish group, but reduced the external beam radiotherapy dose and increased the brachytherapy dose to lower the side-effects. All 16 patients (100%) had R0 resection compared with 63% with conventional preoperative chemoradiotherapy using a bolus 5-fluorouracil regimen. Pathological complete remission was achieved in seven (44%) patients compared with 2-12% with conventional chemoradiotherapy. There was no increase in grade 3-4 toxicity from radiotherapy and no delay in wound healing or anastamotic leakage. The inclusion of high dose rate brachytherapy seems to increase the pathological complete remission rates and improves the R0 resection rates with no detriment to the side-effects as the increased dose of radiation from the high dose rate boost is confined mainly to the tumour. This treatment may be particularly suitable for elderly patients where intensive chemoradiotherapy regimens are not suitable. Several trials are planned to define the role of preoperative high dose rate brachytherapy in rectal cancer and the results are awaited with interest.

Combined Modality Treatment of Early Rectal Cancer — the UK Experience

With the introduction of colorectal screening in the UK, more patients will probably be diagnosed with early rectal cancer. The UK has an increasingly elderly population and not all patients diagnosed with early rectal cancer will be suitable for radical surgery. Therefore, a national plan is needed to develop the provision of alternative local treatment with equity of access across the country. Here we review the Clatterbridge Centre for Oncology multimodality treatment policy, which has been in clinical practice since 1993 and we discuss its rationale. Clatterbridge is the only centre in the UK offering Papillon-style contact radiotherapy. In total, 220 patients have been treated over 14 years, most of whom were referred from other centres. One hundred and twenty-four patients received Papillon (contact radiotherapy) as part of their multimodality management. The guidelines of the Association of Coloproctology of Great Britain and Ireland recommend local treatment for T1 tumours<3 cm in diameter, but this refers to treatment by surgery alone. There are no published national guidelines for radiotherapy. We plan each treatment in stages and achieve excellent local control (93% at 3 years) with low morbidity. We conclude that radical local treatment for cure can be offered safely to carefully selected elderly patients. Close follow-up is necessary so that effective salvage treatment can be offered. Because of a lack of randomised trial evidence, at present local radiotherapy is not yet accepted as an alternative option to the gold standard surgical treatment. Even with international collaboration, a randomised trial will be difficult to complete as the number of cases requiring local radiotherapy is small due to the highly selective nature of the treatment involved. However, an observational phase II trial is planned. In addition, the Transanal Endoscopic Microsurgery Users Group is also planning a phase II trial using preoperative radiotherapy. These studies will provide evidence to help establish the true role of radiotherapy in early rectal cancer.

High affinity IL-2 receptor (CD25) expression among Chronic Lymphocytic leukemia (CLL) patients is independent of mutational status and ZAP-70 positivitys

Background: Recent studies have suggested promising roles for immunotherapy through CD40 ligand /IL-2 signaling pathway in CLL patients. Differential expression of the IL-2 receptor (IL-2 R) has been reported in CLL and other B-cell malignancies. Because CLL is divided into two distinct prognostic groups (based on the level of somatic hypermutation or alternatively on the presence or absence of ZAP-70), it is important to determine the correlation of IL-2 R expression with mutational status and/or ZAP-70 positivity in CLL for better patient group stratification in clinical trials. Methods: In this study, 132 pts (82 M/50F; M: F 1.6) with an age range of 33-91 yrs (median 66 yrs) were included. Of these, 67/132 (51%) were found to be CD25+, 44/132 (33%) CD25- and 16% were CD25 dim (not further analyzed). In terms of ZAP positivity, 19/132 (14%) pts were ZAP-70+ and 113 (86%) were ZAP-70-. Results: Mutational data (n=93) revealed 60/93 (65%) patients with SHM and 33/ 93 (35%) without. Correlation between ZAP-70+ and absence of SHM was highly significant (p< 0.0001), however, no statistically significant correlation was noted between CD25 expression and SHM (p= 0.331) or ZAP positivity (p= 0.785). Conclusions: This data suggests that IL-2 R expression, although noted among a significant proportion of patients with B-CLL, is independent of somatic hypermutation or ZAP-70 expression. This observation will be important in evaluation of clinical efficacy of immunotherapy among CLL patients, and points to the existence of another mechanism for the presence of IL-2 R in these patients. Abbreviations: B-CLL (B-cell Chronic Lymphocytic Leukemia), SHM (Somatic Hypermutation)

The role of HIV infection and drug and alcohol dependence in hospital mortality among critically ill patients

PURPOSE

Critical care outcomes among HIV-infected patients have improved because of advances in HIV therapy and general improvements in intensive care unit (ICU) management. There is a high co-occurrence of drug and alcohol dependence among HIV-infected patients, and the independent role of drug and alcohol dependence among patients with and without HIV infection in outcomes of critical illness is unclear.

MATERIALS AND METHODS

We analyzed a prospectively collected database of 7015 index ICU admissions at 2 teaching hospitals between January 1999 and January 2006. The ICU diagnoses were determined from prospective chart review and classified according to the dictionary of diagnoses developed by the Intensive Care National Audit and Research Council. We used logistic regression to determine the independent association of drug and alcohol dependence as well as HIV infection with in-hospital mortality. Covariates that were adjusted for included acute drug overdose, Acute Physiology and Chronic Health Evaluation II score, age, sex, hospital site, and socioeconomic variables.

RESULTS

Of all patients, 4.4% (309 of 7015) were HIV infected; and of these, 56% (173 of 309) had a history of drug and alcohol dependence, whereas only 7.4% (502 of 6706) of the HIV-negative group had a history of drug and alcohol dependence. Drug and alcohol dependence was not independently associated with hospital mortality in either the model including all admissions (adjusted odds ratio [AOR] 0.80; 95% confidence interval [CI] 0.62-1.03) or the model including pneumonia and sepsis admissions only (AOR 0.92; 95% CI 0.59-1.41). Infection with HIV was independently associated with hospital mortality (AOR 2.16; 95% CI 1.60-2.93).

CONCLUSIONS

Although HIV infection is associated with increased hospital mortality, drug and alcohol dependence is not associated with an increased hospital mortality independent of HIV infection.

DUSP7 and DUSP8 promoter hypermethylations: Predictors of clinical outcomes in advanced epithelial ovarian carcinoma

5501

Background: The Dual specificity phosphatases (DUSPs) are a subclass of the protein tyrosine phosphatase (PTP) gene family which appears to be selective for dephosphorylating the critical phosphothreonine and phosphotyrosine residues within the mitogen-activated protein kinases (MAPKs) leading to inactivation. MAPK activation is a downstream target of several oncogenes and may give rise to oncogenic transformation, and hence DUSPs are potential tumor suppressor genes. The aim of this study was to investigate if DUSPs are subject to methylation-dependent silencing in epithelial ovarian cancer. Methods: In this study, promoter methylation and gene expression of the DUSPs genes (DUSP1, DUSP2, DUSP3, DUSP4, DUSP5, DUSP6, DUSP7, DUSP8 and DUSP10) were investigated in 9 ovarian cancer cell lines and in 74 primary epithelial ovarian tumors (Stage III/IV), using methylation specific PCR (MSP) and Reverse- transcription PCR (RT-PCR). The 74 clinical samples were retrospectively retrieved from a large Phase III RCT (the EORTC 55931/NCIC OV10) with clinical follow-up in excess of 6.5 years. Results: Ovarian Cancer Cell lines: Aberrant CpG methylation detected in DUSP1, DUSP2, DUSP4, DUSP6, DUSP7 and DUSP8. DUSP7 promoter methylation was associated with downregulation of mRNA expression. Primary Ovarian Tumors: Methylation of DUSP1, DUSP2, DUSP7 and DUSP8 was observed in 15–38% of the primary tumors. DUSP7 methylation is a predictor of adverse PFS in both univariate (median PFS 10.6 m versus 13.3m, p=0.002) and multivariate (Cox Regression HR 2.76, p<0.001) analyses, and is associated with a trend for poorer OS (22.1 m versus 29.3 m, p=0.07). In contrast, DUSP8 methylation is an independent predictor of favorable PFS (median 23.7m versus 11.5m; Cox Regression HR 0.30, p=0.006) and OS (HR 0.31, p=0.013). 5-year OS for DUSP8 methylated patients was 58.3% compared with 16.1% for DUSP8 unmethylated (HR 0.277, p=0.005). Conclusion: This is the first report of DUSP methylation in epithelial ovarian cancer. The study suggests that methylation-dependent transcriptional silencing of DUSP7 in advanced epithelial ovarian cancer may represent an independent predictor of adverse PFS. DUSP8 methylation, on the other hand, is a favorable clinical outcome marker.

No significant financial relationships to disclose.

Could increasing the dose of radiation following preoperative chemoradiation for advanced rectal cancer improve surgical outcomes? Clatterbridge experience with HDR brachytherapy boost: Preliminary results

14563

Introduction: Preoperative radiotherapy has been shown to improve local control in advanced rectal carcinoma compared to surgery alone. Recent large randomised trials have confirmed that chemoradiotherapy (CRT) was better than radiotherapy alone. This pilot study was designed to increase the radiation dose by using High dose rate (HDR) brachytherapy boost following preoperative CRT to evaluate whether this strategy improve surgical outcomes, without increase in toxicity. Methods: Since, October 2004 we have used the new Nucletron rectal HDR applicator for brachytherapy boost in 12 patients following pre-op CRT. The patients were staged by CT and MRI Scans. All had locally advanced disease either bulky low T2 or T3 with threatened CRM and multiple suspicious lymph nodes. They were offered preoperative chemoradiotherapy using either 5FU infusion 1G/m2 day 1–4 (wk 1+5) or oral Capecitabine 825mg/m2 Mon-Fri for 5 weeks together with CT planned external beam RT 45Gy in 25 fraction over 5 weeks. Those downstaged on repeat MRI scan were offered additional HDR Boost 10Gy directly to the tumour followed by surgery 6–8 weeks later. Results: Evaluation was done on the first 12 patients. Eleven males and 1 female. Median age 68 (range50–80 years). PS 0–1. Clinical stages at presentation were cT2 in two patients and cT3 in 10 patients. No suspicious lymph nodes in 2 and cN1 in 10 patients. Eleven patients had chemoradiotherapy and one had radiotherapy alone. All patients completed treatment without interruptions. Anterior resection was carried out in 6 patients and 6 had APR. All patients had RO resection (100%) compared to 60–80% with conventional preoperative chemoradiotherapy using 5FU ± Irinotecan or Oxaliplatin regimes. Pathological complete remission pCR was achieved in 6 patients (50%) compared to 12–30% with conventional CRT. There was no increase in G3–4 toxicity from HDR boost and no delay in wound healing or anastamotic leakages. Discussion: Pre operative chemoradiotherapy using 5FU regimes had shown improvement in local control compared to radiotherapy alone but so far, none of the trials showed survival benefit. Newer novel agent such as Irinotecan or Oxaliplatin has been used in addition to 5FU or capecitabine for the pre operative chemoradiotherapy regimes in an attempt to improve surgical out comes. However, there were increased in radiation related G3–4 complications up to 30%. This study has shown that Increasing the dose of radiation by HDR Brachytherapy boost appears to improve the RO resection rates compared to conventional CRT and also increased in pCR rates. The follow up is still too short to evaluate whether there is improvement in DFS but based on previous CRT studies, the local control rate is predicted to improve further without added toxicity. We plan to extend this study to compare this strategy in a randomised phase 3 trial with conventional chemoradiotherapy in patients who are not fit for more intensive chemoradiotherapy using triplet regimes. This approach is suitable for elderly or medically compromised patients who are not fit for intensive chemoradiotherapy with newer agents.

No significant financial relationships to disclose.

Therapeutic resistance and tumor-initiation: Molecular pathways involved in breast cancer stem cell self-renewal

528

Background: Recent evidence supports the existance of a rare subpopulation of ‘cancer stem cells‘ (CSCs) which is chemoresistant and capable of self-renewal and tumor-initiation, resulting in relapse and metastases. We hypothesized that residual breast tumors after conventional chemotherapy (CTx) are enriched for CSCs bearing CD44+/CD24- markers, and show increased self-renewal as demonstrated by mammosphere (MS) forming assays. Molecular pathways like Notch, Wnt, and the polycomb family that regulate normal mammary self-renewal may be in aberrant in CSCs. Methods: Paired breast cancer biopsies from 35 patients were obtained before and after 12 weeks of neoadjuvant CTx (docetaxel 100 mg/m2 or Adriamycin/Cytoxan 60/600 mg/m2, 4 cycles, q3weeks), digested by collagenase, stained with CD24/CD44/lineage antibodies, and analyzed by flow cytometry. MS assays were performed to measure self-renewal ability. Gene expression, using the Affymetrix U133 GeneChip platform, of cancer cells bearing CD44+/CD24- markers vs. all other sorted cells, and between secondary cancer MS vs. the primary bulk invasive cancers were analyzed. Results: CD44+/CD24- cells increased from a median of 4.8% to 14.8% after CTx (p<0.005). Increased self-renewal was demonstrated by an increase in MS capacity after CTx (p=0.03), with a positive correlation between the number of CD44+/24- cells and MS assays (R=0.8, p<0.05). Common molecular pathways shared by CD44+/CD24- cells and MS show increased expression in normal self-renewal pathways - polycomb family (PCGF5), Notch (MAML2), FOXP1, and BBX. In addition, genes governing alternative splicing were increased, including a non-coding RNA (MALAT1) of unknown function, and RNA splicing factors (SFRS3, SFRS21P, SFRS4). Conclusions: Our results with an increase in cells bearing stem cell markers, and increased MS formation of residual tumors provide the first strong clinical evidence for the existance of therapy-resistant cancer stem cells. Post-transcriptional regulation may play a crucial role in modifying gene function involved in cancer stem cell self-renewal. Clinical trials targeting these newly identified pathways may eradicate residual disease and improved cure rates for many breast cancer patients.

[Table: see text]

Glucuronidation in the chimpanzee (Pan troglodytes): studies with acetaminophen, oestradiol and morphine

The chimpanzee has recently been characterized as a surrogate for oxidative drug metabolism in humans and as a pharmacokinetic model for the selection of drug candidates. In the current study, the glucuronidation of acetaminophen, morphine and oestradiol was evaluated in the chimpanzee to extend the characterization of this important animal model. Following oral administration of acetaminophen (600 mg) to chimpanzees (n=2), pharmacokinetics were comparable with previously reported human values, namely mean oral clearance 0.91 vs. 0.62+/-0.05 l h-1 kg-1, apparent volume of distribution 2.29 vs. 1.65+/-0.25 l kg-1, and half-life 1.86 vs. 1.89+/-7h, for chimpanzee vs. human, respectively. Urinary excretions (percentage of dose) of acetaminophen, acetaminophen glucuronide and acetaminophen sulfate were also similar between chimpanzees and humans, namely 2.3 vs. 5.0, 63.1 vs. 54.7, and 25.0 vs. 32.3%, respectively. Acetaminophen, oestradiol and morphine glucuronide formation kinetics were investigated using chimpanzee (n=2) and pooled human liver microsomes (n=10). V(max) (app) and K(m)(app) (or S(50)(app)) for acetaminophen glucuronide, morphine 3- and 6-glucuronide, and oestradiol 3- and 17-glucuronide formation were comparable in both species. Eadie-Hofstee plots of oestradiol 3-glucuronide formation in chimpanzee microsomes were characteristic of autoactivation kinetics. Western immunoblot analysis of chimpanzee liver microsomes revealed a single immunoreactive band when probed with anti-human UGT1A1, anti-human UGT1A6, and anti-human UGT2B7. Taken collectively, these data demonstrate similar glucuronidation characteristics in chimpanzees and humans.

A double-blind placebo-controlled randomized study of Chinese herbal medicine as complementary therapy for reduction of chemotherapy-induced toxicity

BACKGROUND

Chinese herbal medicine (CHM) is a common complementary therapy used by patients with cancer for reduction of chemotherapy-induced toxic effects. This study applied the highest standard of clinical trial methodology to examine the role of CHM in reducing chemotherapy-induced toxicity, while maintaining a tailored approach to therapy.

PATIENTS AND METHODS

Patients with early-stage breast or colon cancer who required postoperative adjuvant chemotherapy were eligible for the study. Enrolled patients were randomly assigned to one of three Chinese herbalists who evaluated and prescribed a combination of single-item packaged herbal extract granules. Patients received either CHM or placebo packages with a corresponding serial number. The placebo package contained nontherapeutic herbs with an artificial smell and taste similar to a typical herbal tea. The primary end points were hematologic and non-hematologic toxicity according to the National Cancer Institute Common Toxicity Criteria Version 2.

RESULTS

One hundred and twenty patients were accrued at the time of premature study termination. Patient characteristics of the two groups were similar. The incidence of grade 3/4 anemia, leukopenia, neutropenia, and thrombocytopenia for the CHM and placebo groups were 5.4%, 47.3%, 52.7%, and 1.8% and 1.8%, 32.2%, 44.7%, and 3.6%, respectively (P = 0.27, 0.37, 0.63, and 0.13, respectively). Incidence of grade 2 nausea was the only non-hematologic toxicity that was significantly reduced in the CHM group (14.6% versus 35.7%, P = 0.04).

CONCLUSIONS

Traditional CHM does not reduce the hematologic toxicity associated with chemotherapy. CHM, however, does have a significant impact on control of nausea.

Weekly Fluorouracil at 425mg/m2 plus Low-dose Folinic Acid for 24 Weeks as Adjuvant Treatment for Colorectal Cancer: Assessment of Toxicity and Delivery

AIMS

To assess the toxicity and dose delivery of weekly bolus 5-fluorouracil (5-FU) at 425 mg/m(2) plus low-dose folinic acid (FA) for 24 weeks as adjuvant treatment for colorectal cancer.

MATERIALS AND METHODS

Data were collected on toxicity and dose reductions, stoppages, delays and intensity from 100 consecutive patients receiving this adjuvant regimen after curative surgery.

RESULTS

There were 53 men and 47 women (median age: 64 and 65 years, respectively); 77 patients with colon cancer and 23 with cancer of the rectum; 34 patients with Dukes' stage B and 66 with Dukes' stage C. Thirty-seven patients experienced at least one grade 3 or 4 toxicity, mainly diarrhoea (20 patients) or fatigue (14 patients). Only one grade 4 toxicity was noted (diarrhoea). In multivariate analysis, increased grade 3 and 4 toxicity was significantly associated with female gender (P = 0.001) and age >65 years (P = 0.046). Forty patients completed the 24 cycles without dose reduction or delay. Forty-one patients required at least one dose reduction. The median 'conventional' dose intensity (DI), calculated from the first cycle to the last, was 408 mg/m(2)/week (96%). The median DI over 24 weeks was 387 mg/m(2)/week (91%). A higher median 24-week DI was delivered to men (407 mg/m(2)/week, 96%) than women (361 mg/m(2)/ week, 85%; P = 0.009). Women older than 65 years showed a significantly reduced median DI over 24 weeks (347 mg/ m(2)/week, 82%) compared with men aged 65 years or younger (407 mg/m(2)/week, 96%; P = 0.049) and men older than 65 years (425 mg/m(2)/week, 100%; P = 0.001), although the difference against women aged 65 years or younger (377 mg/ m(2)/week, 89%) was not statistically significant (P = 0.09).

CONCLUSION

This regimen has shown what might be considered high rates of grade 3 and 4 toxicity for an adjuvant treatment, although the delivered DI was acceptable. Caution is urged in the treatment of elderly female patients who have statistically higher rates of grade 3 and 4 toxicity and lower DI.

Prevalence of complications in children with chronic kidney disease according to KDOQI

The Kidney Disease Outcome and Quality Initiative (KDOQI) Group recommended guidelines for the monitoring and treatment of chronic kidney disease (CKD) in 2002. These recommendations were based on the prevalence of known complications as seen in adults. In children, the exact prevalence of these complications is unknown. We therefore conducted a cross-sectional study of 366 patients with CKD in a single center to analyze the prevalence of these complications across all stages of kidney disease. Patients were categorized to their KDOQI stage of CKD according to their estimated renal function as determined from serum cystatin C. Fifty seven percent of patients had CKD stage 1, 29.0% stage 2, 10.4% stage 3 and 4.1% stages 4+5. Uropathies (31%) were the most prevalent causes of CKD. Glomerular disease accounted for 27%. The overall prevalence of complications was as follows: hypertension 70.2%, anemia 36.6%, proteinuria 11.5%, and metabolic bone disease 16.9%. Metabolic bone disease and anemia occurred frequently, even with a glomerular filtration rate >60 ml/min/1.73 m2. Growth failure (11.5%) was also common and is not a component of the KDOQI guidelines for CKD in children. The prevalence of all complications increased with worsening stage of kidney disease (all P-values significant). In summary, this study supports the KDOQI guidelines in defining and staging CKD in children. This study also highlights the differences in the causes and complications that occur in CKD between adults and pediatrics. We recommend modification of the KDOQI guidelines for children to reflect the differences described in this paper.

Wavelet-based prognostic model with comparative genomic hybridization (CGH) data in patients with hepatocellular carcinoma (HCC)

20026

Background: In order to obtain a good prognostic model for HCC, clinical data alone may not be adequate. DNA microarray technology has enabled quantification of thousands of genes in a single assay but it has the inborn drawback of high background noise. In order to deal with the problem of information overflow, we developed multivariate dependencies approach using CGH to guide the initial modeling process. This approach takes into account the multivariate nature and potential interaction among the genes during the prognostic modeling process. Methods: The study includes 165 patients with CGH data containing 858 regions/bands. The clinical outcome is survival at 1.72 years. Potential prognostic factors include CGH regions, albumin, ALT, bilirubin, AFP, ascites, alkaline phosphatase (ALP), tumor size, and encephalopathy. We used a blocked wavelet-shrinkage principal component analysis (BWSPCA) to reduce the dimension of CGH data with respect to clinical outcome and followed by logistic regression. We compared the BWSPCA with PCA alone, supervised PCA (Bair et al. 2004), and supervised BWSPCA. Results: Among the 165 patients, 133 (80%) were male, average age of 54.8 years, 78 (47%) stage I-II and 75 (45%) ECOG 0–2. PCA alone and supervised PCA models failed to identify significant CGH regions. BWSPCA model includes tumor size (p = 0.005), albumin (p = 0.047), ALP (p = 0.025), Chr.6q25.1 (p = 0.031), Chr.12q24.32 (p = 0.012), Chr.Xq28 (p = 0.035). Supervised BWSPCA approach includes tumor size (p = 0.016), ALP (p = 0.002), Chr.12q24.11 (p = 0.047). The area under the receiver operating curve (ROC) for the BWSPCA model was 0.78 with a sensitivity and specificity about 0.8 and 0.6 respectively. Conclusions: PCA alone is not effective in identifying CGH regions as prognostic factors. Supervised learning approach did not improve the results. The BWSPCA method identified a number of significant CGH regions associated with survival outcome for HCC patients. These results would be verified in future study. This method will be extended and applied to develop prognostic models using both CGH and DNA microarray data. Acknowledgement: This study is funded by the Research Grant Council of Hong Kong #CUHK4469/03M.

No significant financial relationships to disclose.

Factors influencing recent dental graduates' location and sector of employment in Victoria

BACKGROUND

Recruitment and retention of dentists in the public sector and rural areas in Victoria has become increasingly difficult in recent years. There are little available data on the factors that influence the sector and location of practice of new dental graduates. The objective of this study was to investigate the factors considered by new graduates in determining the location and sector of employment after graduation, and influencing any early changes in career path.

METHODS

Questionnaires were sent to dentists who Mgraduated from The Univrersity of Melbourne from graduated from The University of Melbourne from 2000-2003 who were currently practising in Victoria. There were 154 subjects to whom questionnaires were sent and 109 useable questionnaires were returned, a response rate of 74 per cent.

RESULTS

Upon graduation, 53 per cent of the new graduates chose to work in the private sector only, compared to 15 per cent in public sector only and 33 per cent in both. At present, 71 per cent work in the private sector only, 17 per cent in the public sector only and 12 per cent in both. The most important factors for choosing to work in the private sector were receiving broad range of clinical experience, opportunities to familiarize with practice management and providing a continuity of care. The principal factors for practising in the public sector were clinical mentoring and advice, consolidating clinical skills and work environment. Initially, 48 per cent of the sample chose to work in metropolitan areas only, 39 per cent in rural areas only and 13 per cent in both. Factors that influenced the decision to work in rural areas were the broad range of clinical experience and remuneration, while the main factors for choosing to work in metropolitan areas were lifestyle and proximity to family and friends.

CONCLUSIONS

This study found that a large proportion of new dental graduates initially chose to work in the public sector and rural areas on graduation primarily as a means of consolidating their clinical skills. However, retention of dentists in both these areas appears to be a problem, with less than 10 per cent of 2000-2001 graduates still than 10 per cent of 2000-2001 graduates still working in the public sector and only 20 per cent of 2000-2001 graduates still working in rural areas.

A structural model of a seven-transmembrane helix receptor: The Duffy antigen/receptor for chemokine (DARC)

The Duffy antigen/receptor for chemokine (DARC) is an erythrocyte receptor for malaria parasites (Plasmodium vivax and Plasmodium knowlesi) and for chemokines. In contrast to other chemokine receptors, DARC is a promiscuous receptor that binds chemokines of both CC and CXC classes. The four extracellular domains (ECDs) of DARC are essential for its interaction with chemokines, whilst the first (ECD1) is sufficient for the interaction with malaria erythrocyte-binding protein. In this study, we elaborate and analyze structural models of the DARC. The construction of the 3D models is based on a comparative modeling process and on the use of many procedures to predict transmembrane segments and to detect far homologous proteins with known structures. Threading, ab initio, secondary structure and Protein Blocks approaches are used to build a very large number of models. The conformational exploration of the ECDs is performed with simulated annealing. The second and fourth ECDs are strongly constrained. On the contrary, the ECD1 is highly flexible, but seems composed of three consecutive regions: a small beta-sheet, a linker region and a structured loop. The chosen structural models encompass most of the biochemical features and reflect the known experimental data. They may be used to analyze functional interaction properties.

Oscillating drop/bubble tensiometry: effect of viscous forces on the measurement of interfacial tension

The oscillating drop/bubble technique is increasingly popular for measuring the interfacial dilatational properties of surfactant/polymer-laden fluid/fluid interfaces. A caveat of this technique, however, is that viscous forces are important at higher oscillation frequencies or fluid viscosities; these can affect determination of the interfacial tension. Here, we experimentally quantify the effect of viscous forces on the interfacial-tension measurement by oscillating 100 and 200 cSt poly(dimethylsiloxane) (PDMS) droplets in water at small amplitudes and frequencies ranging between 0.01 and 1 Hz. Due to viscous forces, the measured interfacial tension oscillates sinusoidally with the same frequency as the oscillation of the drop volume. The tension oscillation precedes that of the drop volume, and the amplitude varies linearly with Capillary number, Ca=DeltamuomegaDeltaV/gammaa(2), where Deltamu=mu(D)-mu is the difference between the bulk Newtonian viscosities of the drop and surrounding continuous fluid, omega is the oscillation frequency of the drop, DeltaV is the amplitude of volume oscillation, gamma is the equilibrium interfacial tension between the PDMS drop and water, and a is the radius of the capillary. A simplified model of a freely suspended spherical oscillating-drop well explains these observations. Viscous forces distort the drop shape at Ca>0.002, although this criterion is apparatus dependent.

Effect of a single dose of the selectin inhibitor TBC1269 on early and late asthmatic responses

BACKGROUND

Selectins participate in the initial phase of leucocyte migration from circulation to inflamed tissues and may play a role in inflammatory cellular influx into airways in asthma. In the sheep asthma model, TBC1269, a pan-selectin antagonist, reduced late allergen response by 74%.

OBJECTIVE

To determine whether a single dose of TBC1269 inhibits early (EAR) and late (LAR) asthmatic responses, and whether it inhibits sputum leucocyte influx after inhalation allergen challenge in atopic asthmatic subjects treated with bronchodilators only.

METHODS

Twenty-one asthmatic subjects (mean+/-SD, age=32.5+/-6.7 years, 8 males, FEV1 percent predicted=84+/-15%) with known late asthmatic response based on a screening inhalation allergen challenge were randomly assigned to receive intravenous treatment with either placebo (n=11) or TBC1269 (n=10, 30 mg/kg) infused over 15 min immediately prior to a second (post-treatment) allergen challenge at least 4 weeks after the screening challenge. After each challenge, EAR and LAR were monitored for 7 h. In addition, sputum was induced 1 day before and 1 day after each allergen challenge.

RESULTS

TBC1269 did not attenuate the EAR compared with placebo (largest fall in FEV1 within 1 h of 34.1+/-13.9% vs. 31.8+/-12.2% for TBC1269 and placebo groups respectively, P=0.61) or the LAR (largest fall in FEV1 between 3 and 7 h of 39.3+/-15.3% vs. 32.6+/-13.8%, P=0.24). TBC1269 had only minor effects on allergen-induced sputum eosinophilia.

CONCLUSION

We conclude that TBC1269 administered before allergen challenge as a single intravenous dose does not attenuate early or late asthmatic responses to allergen in asthmatic subjects.

Avian influenza in Hong Kong 1997-2002

In 1997, a high-pathogenicity H5N1 avian influenza virus caused serious disease in both man and poultry in Hong Kong, China. Eighteen human cases of disease were recorded, six of which were fatal. This unique virus was eliminated through total depopulation of all poultry markets and chicken farms in December 1997. Other outbreaks of high-pathogenicity avian influenza (HPAI) caused by H5N1 viruses occurred in poultry in 2001 and 2002. These H5N1 viruses isolated had different internal gene constellations to those isolated in 1997. No new cases of infection or disease in man due to these or other H5N1 viruses have been reported. This paper provides an overview and chronology of the events in Hong Kong relating to avian influenza, covering the period from March 1997 to March 2002.

A Bayesian neural network approach for modelling censored data with an application to prognosis after surgery for breast cancer

A Bayesian framework is introduced to carry out Automatic Relevance Determination (ARD) in feedforward neural networks to model censored data. A procedure to identify and interpret the prognostic group allocation is also described. These methodologies are applied to 1616 records routinely collected at Christie Hospital, in a monthly cohort study with 5-year follow-up. Two cohort studies are presented, for low- and high-risk patients allocated by standard clinical staging. The results of contrasting the Partial Logistic Artificial Neural Network (PLANN)-ARD model with the proportional hazards model are that the two are consistent, but the neural network may be more specific in the allocation of patients into prognostic groups. With automatic model selection, the regularised neural network is more conservative than the default stepwise forward selection procedure implemented by SPSS with the Akaike Information Criterion.