Detection of cryptic pathogenic copy number variations and constitutional loss of heterozygosity using high resolution SNP microarray analysis in 117 patients referred for cytogenetic analysis and impact on clinical practice

BACKGROUND

Microarray genome analysis is realising its promise for improving detection of genetic abnormalities in individuals with mental retardation and congenital abnormality. Copy number variations (CNVs) are now readily detectable using a variety of platforms and a major challenge is the distinction of pathogenic from ubiquitous, benign polymorphic CNVs. The aim of this study was to investigate replacement of time consuming, locus specific testing for specific microdeletion and microduplication syndromes with microarray analysis, which theoretically should detect all known syndromes with CNV aetiologies as well as new ones.

METHODS

Genome wide copy number analysis was performed on 117 patients using Affymetrix 250K microarrays.

RESULTS

434 CNVs (195 losses and 239 gains) were found, including 18 pathogenic CNVs and 9 identified as "potentially pathogenic". Almost all pathogenic CNVs were larger than 500 kb, significantly larger than the median size of all CNVs detected. Segmental regions of loss of heterozygosity larger than 5 Mb were found in 5 patients.

CONCLUSIONS

Genome microarray analysis has improved diagnostic success in this group of patients. Several examples of recently discovered "new syndromes" were found suggesting they are more common than previously suspected and collectively are likely to be a major cause of mental retardation. The findings have several implications for clinical practice. The study revealed the potential to make genetic diagnoses that were not evident in the clinical presentation, with implications for pretest counselling and the consent process. The importance of contributing novel CNVs to high quality databases for genotype-phenotype analysis and review of guidelines for selection of individuals for microarray analysis is emphasised.

VITATOPS, the VITAmins TO prevent stroke trial: rationale and design of a randomised trial of B-vitamin therapy in patients with recent transient ischaemic attack or stroke (NCT00097669) (ISRCTN74743444)

BACKGROUND

Epidemiological studies suggest that raised plasma concentrations of total homocysteine (tHcy) may be a common, causal and treatable risk factor for atherothromboembolic ischaemic stroke, dementia and depression. Although tHcy can be lowered effectively with small doses of folic acid, vitamin B(12) and vitamin B(6), it is not known whether lowering tHcy, by means of B vitamin therapy, can prevent stroke and other major atherothromboembolic vascular events.

AIM

To determine whether the addition of B-vitamin supplements (folic acid 2 mg, B(6) 25 mg, B(12) 500 microg) to best medical and surgical management will reduce the combined incidence of stroke, myocardial infarction (MI) and vascular death in patients with recent stroke or transient ischaemic attack (TIA) of the brain or eye.

DESIGN

A prospective, international, multicentre, randomised, double blind, placebo-controlled clinical trial.

SETTING

One hundred and four medical centres in 20 countries on five continents.

SUBJECTS

Eight thousand (6600 recruited as of 5 January, 2006) patients with recent (<7 months) stroke (ischaemic or haemorrhagic) or TIA (brain or eye).

RANDOMISATION

Randomisation and data collection are performed by means of a central telephone service or secure internet site.

INTERVENTION

One tablet daily of either placebo or B vitamins (folic acid 2 mg, B(6) 25 mg, B(12) 500 mug).

PRIMARY OUTCOME

The composite of stroke, MI or death from any vascular cause, whichever occurs first. Outcome and serious adverse events are adjudicated blinded to treatment allocation.

SECONDARY OUTCOMES

TIA, unstable angina, revascularisation procedures, dementia, depression. STATISTICAL POWER: With 8000 patients followed up for a median of 2 years and an annual incidence of the primary outcome of 8% among patients assigned placebo, the study will have at least 80% power to detect a relative reduction of 15% in the incidence of the primary outcome among patients assigned B vitamins (to 6.8%/year), applying a two-tailed level of significance of 5%.

CONCLUSION

VITATOPS aims to recruit and follow-up 8000 patients between 1998 and 2008, and provide a reliable estimate of the safety and effectiveness of folic acid, vitamin B(12), and vitamin B(6) supplementation in reducing recurrent serious vascular events among a wide range of patients with TIA and stroke throughout the world.

Local impact of the English arm of the UK Bowel Cancer Screening Pilot study

Background

The English arm of the UK Bowel Cancer Screening Pilot study recently concluded its third round. The primary aim was to assess the impact of faecal occult blood test (FOBT) screening on the detection of symptomatic (non-screen-detected) cancers within the target age group (50–69 years). The secondary aim was to assess differences between screened and non-screened cohorts in Dukes' classification at diagnosis.

Methods

This population-based study utilized retrospective analysis of existing validated colorectal cancer (CRC) data over 5 years (April 2000 to March 2005), encompassing rounds one and two of screening.

Results

There was a 23 per cent (P = 0·011) reduction in the diagnosis of over the 5 years. Presentations with symptomatic cancer reduced by 49 per cent (P = 0·049), with a proportionate (2·6-fold) rise in the detection of screened (asymptomatic) malignancy. Cancers were diagnosed at an earlier stage in the screened population, with significantly more Dukes' A tumours than in the non-screen-detected cohort (P &lt; 0·001) and an estimated odds ratio of 0·27 (95 per cent confidence interval 0·08 to 0·91) (P = 0·035) for Dukes' ‘D’ cancers.

Conclusion

FOBT screening resulted in a significant reduction in the number of symptomatic cancers detected within the target age group. Tumours detected by screening were diagnosed at an earlier pathological stage.

Mutational activation of ErbB2 reveals a new protein kinase autoinhibition mechanism

Autoinhibition plays a key role in the control of protein kinase activity. ErbB2 is a unique receptor-tyrosine kinase that does not bind ligand but possesses an extracellular domain poised to engage other ErbBs. Little is known about the molecular mechanism for ErbB2 catalytic regulation. Here we show that ErbB2 kinase is strongly autoinhibited, and a loop connecting the alphaC helix and beta4 sheet within the kinase domain plays a major role in the control of kinase activity. Mutations of two Gly residues at positions 776 and 778 in this loop dramatically increase ErbB2 catalytic activity. Kinetic analysis demonstrates that mutational activation is due to approximately 10- and approximately 7-fold increases in ATP binding affinity and turnover number, respectively. Expression of the activated ErbB2 mutants in cells resulted in elevated ligand-independent ErbB2 autophosphorylation, ErbB3 phosphorylation, and stimulation of mitogen-activated protein kinase. Molecular modeling suggests that the ErbB2 kinase domain is stabilized in an inactive state via a hydrophobic interaction between the alphaC-beta4 and activation loops. Importantly, many ErbB2 human cancer mutations have been identified in the alphaC-beta4 loop, including the activating G776S mutation studied here. Our findings reveal a new kinase regulatory mechanism in which the alphaC-beta4 loop functions as an intramolecular switch that controls ErbB2 activity and suggests that loss of alphaC-beta4 loop-mediated autoinhibition is involved in oncogenic activation of ErbB2.

Practices and Provisions for Parents Sleeping Overnight with a Hospitalized Child

OBJECTIVE

To describe practices affecting parents' overnight stays, provisions for parents sleeping overnight and parents' involvement in overnight care of their hospitalized child.

METHODS

A cross-sectional telephone survey of Canadian and American hospitals with more or equal to 50 acute pediatric beds and more or equal to two pediatric wards was conducted.

RESULTS

Surveys were completed by 135 hospitals (77% response rate). All general pediatric units allowed parents to sleep at the bedside overnight; higher acuity units limited parental stays. The majority of hospitals limited overnight visitors at the bedside to one parent, and few hospitals routinely allowed siblings to sleep overnight. One hundred and thirty-three (99%) hospitals reported parental involvement in their child's care at night, with 52 (39%) stating this was an expectation.

CONCLUSIONS

In general, parents are given the opportunity to stay at the bedside overnight, but barriers exist that limit opportunities for sleep during their child's hospitalization, and serve to separate families who have a hospitalized child.

Phase I trial of imexon, Inj. plus gemcitabine in patients with advanced previously untreated pancreatic adenocarcinoma

15058

Background: Imexon for inj. (Amplimexon®, AMP) is an aziridine-containing iminopyrrolidone which causes G2 arrest, accumulation of reactive oxygen species, and induction of apoptosis in pancreatic cancer cells. AMP demonstrated synergy with gemcitabine (GEM) in preclinical pancreatic cancer models. This phase I study of AMP plus GEM was undertaken to determine the maximum tolerated dose (MTD) and dose-limiting toxicities (DLT). Secondary endpoints were pharmacokinetics for both agents (PK) and tumor response. Methods: Patients (pts) with previously untreated advanced pancreatic adenocarcinoma received one of two dosing regimens. The first 19 received 30 minute AMP IV days 1–5 and 15–19 followed by 30 minute GEM IV days 1, 8 and 15 Q4 wks (Regimen A). Dosing was modified after 19 pts to administer both AMP and GEM over 30 minutes days 1, 8 and 15 every 4 weeks (Regimen B). Dose levels (AMP/GEM, in mg/m2) for Regimen A: 200/800, 280/800, 200/1000, and 280/1000, and for Regimen B: 280/1000, 335/1000, 390/1000, 540/1000, and 750/1000. The current cohort is 1000/1000. Pts were assessed for response after cycles 2, 5 and 8. PK and pharmacodynamic (plasma thiol depletion) measurements were obtained during cycle one. Results: Forty-six pts have been treated to date, with 36 having complete toxicity data and evaluable. Pt characteristics: M/F (24/12), Age (mean 60.4 years, range 43–75), ECOG PS 0/1 (56%, 44%), metastatic/locally advanced (91%, 9%). The 36 pts have completed 122.5 cycles of therapy (median 2, range 0.5–12). Common toxicities: anemia (77%), fatigue (71%), nausea (60%), fever (54%), and leukopenia (54%). DLT were 1/6 at 280/1000 (Regimen A - febrile neutropenia), 1/6 at 280/1000 (Regimen B - gr 3 hypotension, gr 4 renal failure), and 1/9 at 390/1000 (gr 3 hyperbilirubinemia). Accrual continues at 1000/1000. Of 36 pts, 4 have had partial responses and 14 stable disease. PK and plasma thiol analysis are ongoing. Conclusions: Imexon can be administered safely with full dose gemcitabine. Accrual continues to define the combination MTD. The response rate in this phase I study compares favorably with historical gemcitabine monotherapy, and further phase II evaluation of this combination in advanced pancreatic cancer is warranted.

No significant financial relationships to disclose.

Impact on quality of life of adding cetuximab to irinotecan in patients who have failed prior oxaliplatin-based therapy: The EPIC trial

4003

Background: EPIC, a multinational phase III clinical trial examined the impact of cetuximab on survival in pretreated EGFR- expressing metastatic colorectal (MCRC) patients (pts). Pts were randomized to either cetuximab 400 mg/m2 followed by 250 mg/m2 weekly and irinotecan 350 mg/m2 q 3 weeks or irinotecan alone. The primary endpoint was overall survival (OS) with quality of life being one of the secondary endpoints. Methods: Health Related Quality of life (HRQoL) of pts in this trial was assessed through the EORTC QLQ-C30 questionnaire, version 3.0. Pts completed the questionnaire pretreatment, every second cycle, and at first follow-up visit. HRQoL was compared between treatment arms using a Wei-Lachin test. Results: Baseline demographics were balanced between the arms. Cetuximab plus irinotecan (n=648) was superior to irinotecan alone (n=650) in progression-free survival (HR 0.69, p<.0001) and response rate (16.4 vs 4.2%, p<.0001). OS was comparable between the arms, but may have been influenced by subsequent therapy: 46% of subjects in the irinotecan alone arm received cetuximab, 89% of them in combination with irinotecan. Baseline HRQoL scores did not significantly differ between treatment arms for 11 of the 15 scales. For 4 scales (Social Functioning, Fatigue, Dyspnea, and Appetite Loss), there were statistically significant differences in baseline scores, in favor of the cetuximab plus irinotecan arm. Non- compliance rates (missing questionnaires) were similar between the arms. A statistically significant difference was noted for pts in the cetuximab plus irinotecan arm in HRQoL on 10 of the 15 scales as compared to patients in the irinotecan arm, with the scores of the cetuximab plus irinotecan arm consistently higher, as noted by the scales of Global Health Status (p=.047), pain (p< .0001), and nausea (p<.0001). Conclusions: In addition to statistically significant improvements in PFS and RR in patients receiving cetuximab plus irinotecan compared with irinotecan alone, HRQoL was better preserved on the combination arm with less deterioration in symptom scores (pain, nausea, insomnia), as well as global health status scores.

No significant financial relationships to disclose.

Combined adjuvant cisplatin and ifosfamide chemotherapy and radiotherapy for malignant mixed müllerian tumors of the uterus

The role of adjuvant therapy for malignant mixed müllerian tumors of the uterus has not been established. Our aim was to review our experience with sequential adjuvant therapy using cisplatin and ifosfamide chemotherapy and radiotherapy after surgical staging. A retrospective study of 43 patients from 1995 to 2004 was undertaken. Survival was calculated using the Kaplan-Meier method and compared by the log-rank test. The Cox proportional hazard regression model was used to assess the effect of treatment on survival after adjustment for age and stage. Twenty-eight patients received adjuvant chemotherapy and 28 patients had adjuvant radiotherapy. Twenty-one patients underwent sequential adjuvant chemotherapy and radiotherapy. Tumor recurrence occurred in 14 patients at a median duration of 10 months. The overall 2- and 5-year survival was 64% and 60%, respectively. The 2- and 5-year survival for stage I and II diseases was both 95%, while the 2-year survival for stage III and IV diseases was 25%. Patients who underwent sequential adjuvant therapy had an improved survival compared with patients who did not follow the protocol (P= 0.024). Our results with sequential adjuvant therapy are encouraging and justify future randomized trials.

Microbiota of plaque microcosm biofilms: effect of three times daily sucrose pulses in different simulated oral environments

AIM

To explore the Ecological Plaque Hypothesis for dental caries. To test modification of the microbiota of dental plaque microcosm biofilms by sucrose pulsing during growth in two different simulated oral fluids, and with a urea-induced plaque pH elevation.

METHODS

Plaque microcosm biofilms were cultured in an 'artificial mouth' with and without 6-min 5% w/v sucrose pulses every 8 h in an environment of continuously supplied saliva-like defined medium with mucin (DMM), or basal medium mucin (BMM, a high-peptone-yeast extract oral fluid analogue), and also in DMM + 10 mmol/l urea, with sucrose pulsing. Forty plaque species were quantified by checkerboard DNA:DNA hybridization analysis.

RESULTS

Sucrose pulsing extended rapid plaque growth in DMM and BMM, inducing major microbiota changes in DMM but not in BMM. In DMM, some streptococci and lactobacilli were unaffected while others implicated in caries, together with Candida albicans and Capnocytophaga gingivalis, increased. Aerobic, microaerophilic and major anaerobic species decreased. Elevation of the pH(max) from 6.4 to 7.0 had almost no effect on the microbiota. BMM plaques were distinct from DMM plaques with particularly low levels of Candida albicans and Actinomyces.

CONCLUSIONS

Modest sucrose exposure in a saliva-like environment causes profound changes in the developmental self-organization of plaque microcosms, supporting the Ecological Plaque Hypothesis. Nevertheless, there is significant stability in microbial composition with varying pH near neutrality. Increases in levels of specific bacteria in response to sucrose could be characteristic of organisms particularly important in caries.

Unravelling the complexities of the NF-κB signalling pathway using mouse knockout and transgenic models

The nuclear factor-kappaB (NF-kappaB) signalling pathway serves a crucial role in regulating the transcriptional responses of physiological processes that include cell division, cell survival, differentiation, immunity and inflammation. Here we outline studies using mouse models in which the core components of the NF-kappaB pathway, namely the IkappaB kinase subunits (IKKalpha, IKKbeta and NEMO), the IkappaB proteins (IkappaBalpha, IkappaBbeta, IkappaBvarepsilon and Bcl-3) and the five NF-kappaB transcription factors (NF-kappaB1, NF-kappaB2, c-Rel, RelA and RelB), have been genetically manipulated using transgenic and knockout technology.

Cetuximab plus irinotecan for metastatic colorectal cancer (mCRC): Safety analysis of 800 patients in a randomized phase III trial (EPIC)

3556

Background: EPIC is a randomized phase III study comparing cetuximab plus irinotecan to irinotecan in second-line metastatic, EGFR-expressing mCRC patients (pts) (target N=1,300 pts). Following an independent Data Safety Monitoring Board (DSMB) review of 400 pts., the pooled safety data was presented at ASCO 2005 (#3580). The DSMB has recently reviewed safety data on the first 800 patients. Methods: Patients with EGFR-expressing mCRC who had failed first-line oxaliplatin in combination with a fluoropyrimidine and an ECOG performance status ≤ 2 were randomized to either Arm A (cetuximab 400 mg/m2 followed by 250 mg/ m2 weekly and irinotecan 350 mg/ m2 q 3 weeks) or to Arm B (irinotecan 350 mg/ m2 q 3 weeks). A pooled safety analysis is presented. Results: Eight hundred patients were randomized from May 2003 to March 2005 in Europe, Australia, Asia, and the US: 309 women and 491 men, with a median age of 61 years (range 21–90) and ECOG performance status (PS) of: 0= 53%, 1= 42%, 2= 5%. Seventeen pts received no study therapy and are excluded from the analysis. A total of 3,629 chemotherapy cycles were administered to the 783 pts with a median of 4 cycles per pt (range 1–23). Four (0.5%) subjects experienced severe infusion reactions: 2 grade 3 and 2 grade 4, none were fatal. In this pooled analysis, 59 deaths occurred within 30 days of last study therapy: 45 disease-related, 5 study drug related, 6 due to other causes, and 3 with unknown etiology. A summary table of adverse events (AE’s) is included. Conclusions: The DSMB raised no concerns after reviewing the safety data from 800 pts. In this pooled analysis characteristic toxicities of cetuximab and irinotecan do not appear to be increased, incidences and severities are similar to the earlier safety report based on the initial 400 patients. The study is currently nearing completion of accrual.

[Table: see text]

[Table: see text]

Phase II trial of depsipeptide (NSC-630176) in colorectal cancer patients who have received either one or two prior chemotherapy regimens for metastatic or locally advanced, unresectable disease: A Southwest Oncology Group study

3598

The treatment for metastatic colorectal cancer has markedly improved but the disease is still not curable, and additional active agents need to be found. Depsipeptide is a histone deacetylase inhibitor that has shown activity against human solid tumor cell lines and promising results in murine model systems. This phase II trial was undertaken to determine its activity in patients with advanced colorectal cancer. Eligibility requirements included measurable disease, either metastatic or locally advanced and not surgically resectable, Zubrod performance status of 0–1, and adequate renal, hepatic, hematologic and cardiac function. Prior surgery or radiation therapy was allowed and patients were required to have received either one or two prior chemotherapy regimens for advanced disease. A two-stage design was used designed to detect a difference in the null hypothesis of 5% response vs. an alternative 20% response, with 20 eligible patients to be accrued initially followed by an additional 20 patients if one or more confirmed responses were observed. The study closed after the first stage, with 28 patients registered. Three patients are ineligible, two who did not meet requirements for serum magnesium level, and one whose baseline labs were performed more than 14 days prior to registration. One eligible patient never received treatment and is not analyzable for any endpoint. For the 24 eligible and analyzable patients, median age was 58.6 years (range 31–84) with 14 males. Performance status was 0 in 16 patients and 1 in 8. Ten patients received 1 prior chemotherapy regimen and 14 received 2 prior regimens. There were no grade 4 or higher toxicities. The most common grade 2 or 3 toxicities were anorexia, fatigue, nausea, and dehydration. No objective responses were observed. Four patients had stable disease, 15 showed increasing disease, 3 had symptomatic deterioration, and 2 had assessment inadequate. The current Kaplan-Meier estimate of 6 month overall survival is 69% (95% CI 50%-88%) with a median survival of 8.4 months. Depsipeptide does not show significant anti-tumor activity in previously treated patients with advanced colorectal cancer.

No significant financial relationships to disclose.

Combined adjuvant cisplatin and ifosfamide chemotherapy and radiotherapy for malignant mixed müllerian tumors of the uterus

The role of adjuvant therapy for malignant mixed müllerian tumors of the uterus has not been established. Our aim was to review our experience with sequential adjuvant therapy using cisplatin and ifosfamide chemotherapy and radiotherapy after surgical staging. A retrospective study of 43 patients from 1995 to 2004 was undertaken. Survival was calculated using the Kaplan–Meier method and compared by the log-rank test. The Cox proportional hazard regression model was used to assess the effect of treatment on survival after adjustment for age and stage. Twenty-eight patients received adjuvant chemotherapy and 28 patients had adjuvant radiotherapy. Twenty-one patients underwent sequential adjuvant chemotherapy and radiotherapy. Tumor recurrence occurred in 14 patients at a median duration of 10 months. The overall 2- and 5-year survival was 64% and 60%, respectively. The 2- and 5-year survival for stage I and II diseases was both 95%, while the 2-year survival for stage III and IV diseases was 25%. Patients who underwent sequential adjuvant therapy had an improved survival compared with patients who did not follow the protocol (P = 0.024). Our results with sequential adjuvant therapy are encouraging and justify future randomized trials.

EGFR kinase possesses a broad specificity for ErbB phosphorylation sites, and ligand increases catalytic-centre activity without affecting substrate binding affinity

We previously found that EGF (epidermal growth factor) increases the EGFR (EGF receptor) kinase-binding affinity towards the major tyrosine phosphorylation sites in downstream adaptor proteins such as Gab1 (Grb2-associated binding protein 1) and Shc [Src homology 2 (SH2) domain and collagen containing protein], but not that towards EGFR autophosphorylation sites [Fan, Wong, Deb and Johnson (2004) J. Biol. Chem. 279 , 38143-38150]. EGFR activation can also result in transphosphorylation of tyrosine resides in the C-terminal region of the related receptors ErbB2, ErbB3 and ErbB4 in heterodimers which are formed upon ligand stimulation. In the present study, we investigated the specificity of EGFR kinase by comparing the steady state kinetic parameters for peptides derived from all four ErbBs in the absence or presence of EGF. Our results demonstrated that (i) EGFR kinase can efficiently phosphorylate a broad range of diverse peptide sequences representing ErbB sites; (ii) certain ErbB2, ErbB3 and ErbB4 sites had higher specificity constants than any EGFR sequence and (iii) EGF stimulation consistently increases the k(cat) approx. 5-fold, but does not significantly alter the K(m) for any ErbB peptides. Furthermore, peptides containing lysine at position -2 or -3 N-terminal to the target tyrosine were found to be poor EGFR kinase substrates, and substitution of these lysines with glutamine decreased the K(m) and increased the k(cat) for these substrates. We conclude that EGFR kinase-mediated ErbB transphosphorylations are mostly controlled at the level of oligomerization, and not by a preference of the EGFR kinase for phosphorylation sites in any particular ErbB. The results also demonstrated that, unlike phosphorylation sites in select downstream targets, EGF does not regulate the recognition of phosphorylation sites in the C-terminal region of any of the ErbBs.

Knowledge and Attitudes About Deceased Donor Organ Donation in Filipinos: A Qualitative Assessment

Fewer ethnic minorities, especially Asian-Americans, become organ donors. There are cultural, religious, and personal barriers to becoming a designated organ donor. Factors that promote or inhibit organ donation in Asians, especially Filipinos, are not well understood. We conducted a series of focus groups to identify barriers and facilitators to organ donation (deceased donor) among Filipinos. Six focus groups were conducted with church members, adolescents, nurses, physicians, organ recipients, and organ donor families. The mean age of adult participants (n = 57) was 52.3 +/- 15 years, 83% were Catholic, and 72% were female. A qualitative theme analysis methodology identified dominant themes related to organ donation in the participants. The major themes were: awareness of organ donation (38%), family beliefs (25%), religion/spirituality (10%), attitude/emotions (10%), personal experience with organ donation (8%), health profession (6%), and cultural issues (3%). Seventy-five percent of the comments about awareness reflected a positive awareness of cultural issues regarding organ donation, and the rest reflected a lack of awareness or misconceptions. Almost every theme was mentioned in all six focus groups. Understanding a specific ethnic group's knowledge, attitudes, and cultural beliefs regarding organ donation is important in the development of educational campaigns to encourage organ donation in ethnic minority populations.

Survey of aflatoxins in beer sold in Canada

Between March 1998 and March 2002, 304 samples of domestic (Canadian) and imported beers from 36 countries were picked up for the determination of aflatoxins B1, B2, G1 and G2. Twelve samples were positive with aflatoxins greater than the limit of quantitation (LOQ) (aflatoxin B1, 4.4 ng l(-1); aflatoxin B2, 3.4 ng l(-1); aflatoxin G1, 11.2 ng l(-1); and aflatoxin G2, 6.2 ng l(-1)). Five samples from Mexico, two samples from Spain and one from Portugal contained aflatoxin B1. Four samples from India contained aflatoxins B1 and B2. The remaining samples contained less than the LOQ for aflatoxins B1, B2, G1 and G2. The analytical method for this survey was based on that of Scott and Lawrence (Scott PM, Lawrence GA. 1997. Determination of aflatoxins in beer. Journal of AOAC International 80:1229-1234.). Aflatoxins B1, B2, G1 and G2 were determined at parts per trillion (ng l(-1)) levels in beer by immunoaffinity column cleanup followed by derivatization with trifluoroacetic acid and reversed-phase liquid chromatography with fluorescence detection.

Single vs. two steroid injections for carpal tunnel syndrome: a randomised clinical trial

We investigated the efficacy of a single vs. double steroid injections in the treatment of carpal tunnel syndrome (CTS) in a randomised double-blind controlled trial. Patients with idiopathic CTS were randomised into (i) one group receiving a baseline methylprednisolone acetate injection plus a saline injection 8 weeks later and (ii) a second group receiving methylprednisolone acetate injection at baseline and at 8 weeks. The primary outcome was the Global Symptom Score (GSS). Forty patients were recruited. By 40 weeks, the mean GSS improved from 25.6 to 14.1 in the single-injection group whereas from 26.7 to 12.6 in the reinjection group, but there was no significant difference in GSS between the two groups (p = 0.26). There were also no significant differences in terms of electrophysiological and functional outcomes. The results suggest that an additional steroid injection confers no added benefit to a single injection in terms of symptom relief.

The effects of methotrexate on Drosophila development, female fecundity, and gene expression

Methotrexate (MTX), a synthetic folate analog, is a tight-binding inhibitor of dihydrofolate reductase (DHFR), a key enzyme for the biosynthesis of purines, thymidylate, and several amino acids. As a consequence, MTX decreases titres of reduced folates, interferes with DNA synthesis, and results in the arrest of rapidly proliferating cells, making it a drug of choice for the treatment of a variety of cancers and auto-immune disorders. MTX is also a known teratogen in all higher animals tested, but there is little information about the effects of this drug on invertebrates. Here we show that MTX has little effect on the survival of Drosophila melanogaster adult flies, but severely diminishes female fecundity. Reduced oviposition, coupled with aberrant egg morphologies, resulted in near sterility of MTX-treated females. Rare surviving progeny showed developmental abnormalities including larval tumors, and bristle, wing, eye, and leg defects. To determine if these phenotypes could be attributed solely to DHFR inhibition, microarray analysis was undertaken and included MTX-treated females, ovaries, and cell line samples. Genes encoding transcripts that were perturbed by the drug were verified using quantitative real-time RT-PCR. Many of these genes were involved in cell cycle regulation, signal transduction, transport, defense response, transcription, or various aspects of metabolism. These studies show that MTX treatment has multiple targets and, in addition, provides a new invertebrate model for the study of teratogenesis.

Identification and characterization of SSTK, a serine/threonine protein kinase essential for male fertility

Here we describe and characterize a small serine/threonine kinase (SSTK) which consists solely of the N- and C-lobes of a protein kinase catalytic domain. SSTK protein is highly conserved among mammals, and no close homologues were found in the genomes of nonmammalian organisms. SSTK specifically interacts with HSP90-1beta, HSC70, and HSP70 proteins, and this association appears to be required for SSTK kinase activity. The SSTK transcript was most abundant in human and mouse testes but was also detected in all human tissues tested. In the mouse testis, SSTK protein was localized to the heads of elongating spermatids. Targeted deletion of the SSTK gene in mice resulted in male sterility due to profound impairment in motility and morphology of spermatozoa. A defect in DNA condensation in SSTK null mutants occurred in elongating spermatids at a step in spermiogenesis coincident with chromatin displacement of histones by transition proteins. SSTK phosphorylated histones H1, H2A, H2AX, and H3 but not H2B or H4 or transition protein 1 in vitro. These results demonstrate that SSTK is required for proper postmeiotic chromatin remodeling and male fertility. Abnormal sperm chromatin condensation is common in sterile men, and our results may provide insight into the molecular mechanisms underlying certain human infertility disorders.

Burns and diabetes

Diabetes is often considered a risk factor for poor wound healing and increased complication rates for plastic surgery procedures. Burn injury in diabetic patients may have implications for the length of stay and number of operations required. We therefore we examined the characteristics of diabetic patients admitted to our burn unit and the impact of their condition on their hospital course. Charts of all patients with diabetes admitted to the burn unit from 1995 to 2000 were reviewed (n = 73). Demographic data, percent body surface area burned, anatomical location of the burn, number of surgical procedures required, length and cost of stay, and outcome were noted. The control population included 150 consecutive patients without diabetes treated during the same period. Diabetic patients were older and underwent a higher number of surgical procedures, with increased length of stay and increased mortality, despite an equivalent body surface area burned. They had a higher incidence of scald burns in the lower extremities than the non-diabetic population. This work shows that diabetic patients constitute a unique group. They are significantly older, have an increased rate of surgical interventions, increased hospital stay, and significantly increased mortality compared to a control group with similar surface area burns. This group is also more likely to have scald burns in the lower extremities, mostly due to diabetic neuropathy. This work emphasizes the importance of education and prevention programmes directed towards this group of patients, in order to decrease morbidity, mortality, and hospital costs.

Epidemiology of venous thromboembolism in Asian patients undergoing major orthopedic surgery without thromboprophylaxis. The SMART study

BACKGROUND

In Asian patients undergoing surgery, the incidence of venous thromboembolism (VTE) is thought to be low relative to Western patients, and the routine use of thromboprophylaxis is controversial.

OBJECTIVES

The aim of this work was to study the epidemiology of VTE in Asian patients undergoing orthopedic surgery without thromboprophylaxis.

PATIENTS AND METHODS

We performed a prospective observational study of a cohort of consecutive Asian patients hospitalized for total hip or knee replacement or hip fracture surgery without thromboprophylaxis. The primary study outcome was the incidence of the composite of symptomatic VTE or sudden death at hospital discharge. This outcome was also assessed at 1 month's follow-up.

RESULTS

Between April 2001 and July 2002, 2420 patients were enrolled. Median age was 68 years and the median duration of hospital stay was 13 days. The rate of symptomatic VTE or sudden death as notified by investigators was 2.3%[55 patients, 99% confidence interval (CI) 1.6, 3.2] and 1.2% (28 patients, 99% CI 0.7, 1.8) after adjudication by an independent committee. Chronic heart failure, varicose veins and a history of VTE were independent risk factors (P < 0.05) for the occurrence of the primary endpoint. At 1 month's follow-up, the incidence of adjudicated symptomatic VTE or sudden death was 1.5% (35/2264 patients).

CONCLUSION

In Asian patients, the incidence of symptomatic VTE after major orthopedic surgery is not low, consistent with the rates observed in Western countries. The use of thromboprophylaxis should be considered in Asian patients undergoing such high-risk surgical procedures.

Clinical and electrophysiological features in Chinese patients with Kennedy’s disease

Kennedy's disease is a X-linked neuromuscular disorder caused by an expanded trinucleotide repeat in the androgen receptor gene. To ascertain the clinical diagnosis of Kennedy's disease in a Chinese population, we used a rapid, accurate PCR-based sizing method for the CAG repeat allelotype. The clinical and electrophysiological features of affected patients are described. The CAG repeats ranged from 43 to 53 and were inversely correlated with the age of onset (r = -0.63; P < 0.005).

Nutrient removal from farm effluents

The objectives of the study were: (i) to examine the efficiency of nutrient removal during the treatment of dairy farm effluent in a two-pond system, and (ii) to produce an inexpensive but effective nutrient trap which could be recycled as a nutrient source or soil mulch. The concentration of chemical oxygen demand (COD), biological oxygen demand (BOD), nitrogen (N), phosphorus (P) and potassium (K) in a two-pond system used to treat dairy farm effluent was monitored over a period of 7 months. The retention of nutrients by two porous materials was examined both in the laboratory batch (zeolite and bark) and pilot-scale field (bark) experiments. The results indicated that biological treatment of farm effluents using the two-pond system was not effective in the removal of nutrients, which are likely to become pollutant when discharged to waterways. Both the bark and zeolite materials were effective in the removal of N, P and K from effluent. These materials can be placed in the second (i.e., aerobic) pond to treat effluents, which can then be discharged to streams with minimum impact on water quality. The nutrient-enriched porous materials can be recycled as a source of nutrients and soil conditioner.

Ligand regulates epidermal growth factor receptor kinase specificity: activation increases preference for GAB1 and SHC versus autophosphorylation sites

The epidermal growth factor receptor (EGFR) kinase catalyzes phosphorylation of tyrosines in its C terminus and in other cellular targets upon epidermal growth factor (EGF) stimulation. Here, by using peptides derived from EGFR autophosphorylation sites and cellular substrates, we tested the hypothesis that ligand may function to regulate EGFR kinase specificity by modulating the binding affinity of peptide sequences to the active site. Measurement of the steady-state kinetic parameters, K(m) and k(cat), revealed that EGF did not affect the binding of EGFR peptides but increased the binding affinity for peptides corresponding to the major EGFR-mediated phosphorylation sites of the adaptor proteins Gab1 (Tyr-627) and Shc (Tyr-317), and for peptides containing the previously identified optimal EGFR kinase substrate sequence EEEEYFELV (3-7-fold). Conversely, EGF stimulation increased k(cat) approximately 5-fold for all peptides. Thus, ligand changed the relative preference of the EGFR kinase for substrates as evidenced by EGF increases of approximately 5-fold in the specificity constants (k(cat)/K(m)) for EGFR peptides, whereas approximately 15-40-fold increases were observed for other peptides, such as Gab1 Tyr-627. Furthermore, we demonstrate that EGF (i) increased the binding affinity of EGFR to Gab1 Tyr-627 and Shc Tyr-317 sites in purified GST fusion proteins approximately 4-6-fold, and (ii) EGF significantly enhanced the phosphorylation of these sites, relative to EGFR autophosphorylation, in cell lysates containing the full-length Gab1 and Shc proteins. Analysis of peptides containing amino acid substitutions indicated that residues C-terminal to the target tyrosine were critical for EGF-stimulated increases in substrate binding and regulation of kinase specificity. To our knowledge, this represents the first demonstration that ligand can alter specificity of a receptor kinase toward physiologically relevant targets.

Educational outreach in diabetes to encourage practice nurses to use primary care hypertension and hyperlipidaemia guidelines (EDEN): a randomized controlled trial

OBJECTIVE

To determine the effectiveness of specialist nurse delivered education in primary care to improve control of hypertension and hyperlipidaemia in patients with diabetes.

DESIGN AND SETTING

Practice-level randomized controlled trial, Salford, England.

SUBJECTS

From 44 practices, 10 303 subjects presenting in general practice with raised blood pressure (= 140/80 mmHg), raised total cholesterol (= 5.0 mmol/l) or both.

INTERVENTIONS

Practices were randomized to receive either the intervention for hyperlipidaemia or for hypertension; practices acted as control for the intervention not received. Specialist nurses arranged a schedule of visits with general practitioners and general practice nurses, reminding them of diabetes protocols and clinical targets. They provided educational materials and protocols used in secondary care for nurse and doctor interventions including stepping up pharmacotherapy when necessary. Practices received a list of patients in their practice who were poorly controlled at their last annual review; new and recalled patients were targeted.

OUTCOME MEASURES

At subsequent annual review, blood pressure and total cholesterol values were obtained from the Salford electronic diabetes register for patients from participating practices.

RESULTS

Overall, specialist nurse-led educational outreach to primary care was associated with no improvement in patients achieving target after 1 year-odds ratio (OR): 1.03 (95% CI 0.95-1.11; P = 0.52). Similar results were achieved with hyperlipidaemia OR: 1.04 (95% CI 0.88-1.23; P = 0.62) and hypertension OR: 1.01 (95% CI 0.80-1.27; P = 0.93).

CONCLUSION

This study provides evidence that the use of specialist nurses to perform educational outreach to improve target adherence to patients with diabetes in primary care is not effective.

Mutation analysis of the RET gene in total intestinal aganglionosis by wave DNA fragment analysis system

BACKGROUND/PURPOSE

Total intestinal aganglionosis (TIA) extending from the duodenum to the rectum is the most rare form of Hirschprung's disease (HSCR) and usually is fatal. RET is the major gene associated with HSCR, and germline mutations of this gene account for up 50% of familial and up to 15 to 20% of sporadic cases in HSCR. The aim of this study was to investigate DNA variants in the RET gene in TIA patients using the WAVE DNA Fragment Analysis System.

METHODS

Genomic DNA was extracted from whole blood samples from 6 patients with TIA. Polymerase chain reaction (PCR) amplification of the 21 exons of RET was performed using published oligonucleotide primers. Heteroduplexes were followed by the WAVE DNA Fragment Analysis System with the DNASep cartridge.

RESULTS

WAVE system technology detected 16 variants in the RET gene in the 6 patients with TIA. Three patients had a significant mutation in exon 8, 11, and 15, respectively. Thirteen RET polymorphic variants also were detected in the 6 patients, with L746L variant in exon 13 occurring in 4 patients.

CONCLUSIONS

WAVE system technology is an efficient method for the detection of DNA sequence variants. Our findings suggest that not only RET mutations but also RET polymorphic variants may contribute to the occurrence of TIA.

Oral lichenoid lesions (OLL) and mercury in amalgam fillings

84 patients with oral lichenoid lesions (OLL) were seen in the contact dermatitis clinic. All these patients had reticulate, lacy, plaque-like or erosive lichenoid changes adjacent to amalgam fillings. Patch testing to metallic mercury, 0.1% thimerosal, 1% ammoniated mercury, 0.1% mercuric chloride, and in some cases 0.05% phenylmercuric nitrate and amalgam discs was undertaken. 33 (39%) patients had positive patch test findings. 30/33 patch test positive patients had replacement of their amalgam fillings, with 28 (87%) patients experiencing improvement of symptoms and signs within 3 months. This confirms that mercury allergy is a factor in the pathogenesis of OLL in some cases. In cases where patch test negative patients improve with amalgam replacement, mercury may be acting as an irritant in the pathogenesis of OLL.

Calcium phosphate deposition in human dental plaque microcosm biofilms induced by a ureolytic pH-rise procedure

The objectives were to develop and characterize a procedure based on a ureolytic pH rise to deposit calcium phosphate into microcosm dental plaque biofilms and to test the importance of the plaque pH range. Plaque biofilms were cultured in a multiplaque culture system ('artificial mouth') with a continuous supply of a simulated oral fluid (basal medium mucin; BMM) with 146 mmol/l (5% w/v) sucrose periodically applied over 6 min every 8h. After initial plaque growth, the biofilms were periodically exposed for up to 16 days to 6-min applications of calcium phosphate monofluorophosphate urea (CPMU) solution containing 20 mmol/l CaCl(2), 12 mmol/l NaH(2)PO(4), 5 mmol/l monofluorophosphate and 500 mmol/l urea (pH 5.0). Three application regimes were examined, one included a sucrose-induced acidic pH fluctuation. Plaque hydrolysis of the urea in CPMU caused the pH to rise to between 8.2 and 8.8, depositing fluoridated and carbonated calcium phosphates, and possibly some calcium carbonate, into the plaque. Calcium, phosphate and fluoride deposition was rapid for about 4 days and then slowed. After 10 days' treatment under standard conditions (BMM containing 1 mmol/l urea and 1 mmol/l arginine), plaque calcium and phosphate concentrations had increased up to 50-fold and 10-fold to approximately 2-4 and 1-2 mmol/g plaque protein, respectively. The calcium, phosphate and fluoride content increased steadily. Calcium phosphate deposition was proportional to the plaque resting pH, increasing over four-fold when the BMM urea concentration was increased from 0 to 20 mmol/l, which raised the resting pH from 6.4 to 7.2 and yielded a mean plaque calcium concentration of 14.3 mmol/g protein, one subsample reaching 20.8 mmol/g protein. Supplementation of BMM with 20% human serum inhibited deposition. These results support the hypothesis that an alkaline pH in plaque is critical in promoting plaque mineralization and that mineral deposition is modulated by serum. These factors are likely to be important in regulating calculus formation.