Morphological study of endothelial cells during freezing

Microvascular injury is recognized as a major tissue damage mechanism of ablative cryosurgery. Endothelial cells lining the vessel wall are thought to be the initial target of freezing. However, details of this injury mechanism are not yet completely understood. In this study, ECMatrix 625 was used to mimic the tumour environment and to allow the endothelial cells cultured in vitro to form the tube-like structure of the vasculature. The influence of water dehydration on the integrity of this structure was investigated. It was found that the initial cell shape change was mainly controlled by water dehydration, dependent on the cooling rate, resulting in the shrinkage of cells in the direction normal to the free surface. As the cooling was prolonged and temperature was lowered, further cell shape change could be induced by the chilling effects on intracellular proteins, and focal adhesions to the basement membrane. Quantitative analysis showed that the freezing induced dehydration greatly enhanced the cell surface stresses, especially in the axial direction. This could be one of the major causes of the final breaking of the cell junction and cell detachment.

Association of lipoprotein lipase S447X, apolipoprotein E exon 4, and apoC3 -455T>C polymorphisms on the susceptibility to diabetic nephropathy

Diabetic nephropathy (DN) is the leading cause of end-stage renal disease. In DN patients, triglyceride (TG) level is elevated and lipoprotein lipase (LPL) activity, which hydrolyzes TG, is decreased. The LPL S447X and apolipoprotein E (APOE) exon 4 polymorphisms affect TG levels, and the APOC3 -455T>C polymorphism affects LPL activity. Our aim was to examine the association of these polymorphisms with nephropathy in type 2 diabetes. We examined these polymorphisms in a case-control study of type 2 diabetic patients including 374 with DN and 392 without DN. LPL 447X-containing genotypes (447X+) were significantly decreased in DN patients [18.6 vs 25.6%, odds ratio (OR) = 0.66, p = 0.02], as were APOE epsilon3/epsilon3 genotypes (64.8 vs 73.1%, OR = 0.68, p = 0.01). In addition, combinations of genotypes [APOE epsilon3/epsilon3 and LPL 447X+ (OR = 0.56), APOC3 CC and LPL 447X+ (OR = 0.31), APOE epsilon3/epsilon3 and APOC3 CC (OR = 0.61] were protective for DN compared with the most common combination of the respective polymorphisms. Our findings suggest the importance of interactions among lipid genes in modulating the risk of DN.

The apolipoprotein A-IV Gln360His polymorphism predicts progression of coronary artery calcification in patients with type 1 diabetes

AIMS/HYPOTHESIS

Individuals with type 1 diabetes have an increased incidence of coronary artery disease (CAD) and a higher risk of cardiovascular death compared with individuals of the same age in the general population. While chronic hyperglycaemia and insulin resistance partially explain excess CAD, little is known about the potential genetic determinants of accelerated coronary atherosclerosis in type 1 diabetes. The aim of the present study was to evaluate the association of apolipoprotein A-IV (APOA4) polymorphisms with coronary artery calcification (CAC) progression, a marker of subclinical atherosclerosis.

SUBJECTS AND METHODS

Two previously well-studied functional APOA4 polymorphisms resulting in the substitution of the amino acid Thr for Ser at codon 347 and Gln for His at codon 360 were genotyped in 634 subjects with type 1 diabetes and 739 non-diabetic control subjects, the participants of the prospective Coronary Artery Calcification in Type 1 Diabetes (CACTI) study.

RESULTS

The His360 allele was associated with a significantly higher risk of CAC progression among patients with type 1 diabetes (33.7 vs 21.2%, p=0.014), but not in the control subjects (14.1 vs 11.1%, p=0.42). Logistic regression analysis confirmed that the presence of the APOA4 His360 allele predicts an increased risk of progression of coronary atherosclerosis in adults with type 1 diabetes of long duration (odds ratio = 3.3, p=0.003 after adjustment for covariates associated with CAD risk). CONCLUSIONS /INTERPRETATION: This is the first report suggesting an association between the APOA4 Gln360His polymorphism and risk of CAC progression in subjects with type 1 diabetes. Additional studies are needed to explore potential interactions between APOA4 genotypes and metabolic/oxidative stress components of the diabetic milieu leading to rapid progression of atherosclerosis.

Dose increases in patients with chronic myeloid leukemia (CML) treated with imatinib mesylate (IM): Estimated using administrative claims data in a US managed care population

16014

Background: Dose increase is often the first step when resistance is encountered in CML patients treated with IM. The primary objective of this study is to determine the proportion of CML patients who experienced a dose increase from their starting dose within one year after initiation of IM therapy. Methods: Patients ≥18 years of age diagnosed with CML (ICD-9-CM code = 205.1) between 2001 and 2003 and treated with IM were identified in the Pharmetrics Integrated Claims Database which covers a US managed care population. Eligible patients had at least two claims for IM and were continuously enrolled for at least six months following their first IM prescription. Follow-up was one year after their first IM prescription. Results: A total of 113 CML patients using IM were identified. Eighty-four percent of these patients started IM at 400 mg/day; eight percent started at doses ≥ 600 mg/day; remaining started at doses < 400 mg/day The mean daily dose of IM used by the study group was 419 mg (SD = 91). Nineteen percent of users required at least one dose increase from their starting dose within one year. The first dose increase was most frequently 200 mg/day (mean daily dose = 574 mg (SD = 199). The median maximum daily dose reached by patients experiencing dose increases was 600 mg/day (25th– 75th percentile: 500, 750 mg). The median ending dose in these patients was 600 mg/day (25th–75th percentile: 400, 600 mg). Median time to first dose increase was 5.8 (25th–75th percentile: 2.0, 7.4 months). Median time to maximum dose from initial IM dose was 6.5 (25th–75th percentile: 2.7, 7.4 months). Conclusions: Nearly 20% of all IM-treated CML patients required a dose increase of approximately 200 mg/day within one year. Of those dose increases, 50% occurred within the first 6 months.

No significant financial relationships to disclose.

Dasatinib (D) in patients with accelerated phase chronic myeloid leukemia (AP-CML) who are resistant or intolerant to imatinib: Results of the CA180005 ’START-A’ study

6526

Background: Dasatinib (D) (BMS-354825) is an oral multi-targeted kinase inhibitor with preliminary evidence of efficacy in a previously reported phase I study. START A is an open-label study of dasatinib in AP-CML pts who were imatinib resistant (IM-R) or imatinib intolerant (IM-I). Methods: A total of 192 pts were enrolled between December 2004 and Jun 2005 in 39 centers worldwide. Dasatinib was given orally at 70 mg twice daily (BID). Dose escalations to 100 mg BID were allowed for poor initial response and reductions to 50 or 40 mg BID for persistent toxicity. Evaluations were weekly blood counts and monthly bone marrow evaluation including cytogenetics. The primary endpoint was major confirmed (maintained at least 4 weeks) hematologic response (MaHR) in IM-R pts. Results: The first 107 pts (99 IM-R, 8 IM-I) with at least 6 months of follow-up are currently reported; there were 55 males/52 females; median age 57 years (range 23–86); median time from diagnosis of CML 90.9 months. Prior therapy included IM>600 mg/day in 63 (59%) pts, interferon in 80 (75%) pts. Major cytogenetic response (MCyR) to prior IM was seen in 34 (32%) pts. 56 pts had Bcr-Abl kinase domain mutations. Median duration of therapy was 5.5 months. MaHR was documented in 63 (59%) pts (95% CI: 49–68) with complete hematologic response in 35 (33%) and no evidence of leukemia in 28 (26%). In IM-R pts, the MaHR rate was 59%. MCyR was documented in 33 (32%) pts (95% CI: 22.9–41.6); complete in 23 (22%), partial in 10 (10%). MaHR were seen in pts with Bcr-Abl mutations and in pts who never responded to IM. Molecular response analysis is ongoing. There were 15 disease progressions including one loss of MaHR. Myelosuppression was significant with grade 3–4 thrombocytopenia and neutropenia in 79% and 69% of pts, respectively. Non-hematologic toxicities were generally mild to moderate. The most frequent were diarrhea (46%), peripheral edema (27%), pleural effusion (16%), rash (8%), and GI hemorrhage (7%). Conclusions: Dasatinib was very effective in IM-R pts with AP-CML with high rates of durable MaHR and MCyR. Data on all 192 pts will be presented at the meeting.

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A timing and process flow analysis of opening clinical trials within an oncology cooperative group setting: The case of the CALGB

6015

Background: Cooperative oncology groups are major sponsors of Phase III clinical trials, yet the number of steps and times required to setup and open such a trial have yet to be studied. This study assesses these items in the Cancer and Leukemia Group B (CALGB) for all Phase III studies opened in a 3 year period. Methods: Step 1: headquarters and statistical center staff were interviewed to discover the detailed steps required for a study to transit from initial concept submission by a potential study chair to final activation of the study. The formal procedures manuals were also reviewed. All study records and draft protocol documents were inspected to verify and identify additional setup steps. Finally, data was collected through direct contact with study chairs and disease committee chairs. Step 2: timing data for each of the major functions or processes were collected. All times are from initial initiation of the function to the final completion of the task. Times represent calendar time. Step 3: creation of stream-lined process flows, currently underway. Members from the CALGB and the Vanderbilt Center for Management Research in Healthcare (cmrhc.org) will spend 2 days creating a process to significantly reduce the time and the number of steps to opening a trial. Results: A total of 13 Phase III studies were activated during the 3 years study period. 372 processes are required to open a Phase III at CALGB, which include 314 work steps, 43 major decision points. Interesting, most of the decision points (63%) are external to CALGB. There are 23 processing loops that require repeating processes. The process map, which lists all processes, is a chart 243.5” × 41 in 8 pt font (or about the length of a 20 passenger bus). Median calendar days to activate a Phase III study at CALGB is 767 days (min = 488, max = 1,441). The three functions requiring the greatest median days are protocol development (477), forms development (434), and regulatory affairs (350). Conclusion: It can require years to open a Phase III study at a major cooperative oncology group. Using process redesign techniques, we expect to be able to significantly streamline the process. Support provided by the NCI.

No significant financial relationships to disclose.

Frequency of treatment changes observed in chronic myeloid leukemia (CML) patients using imatinib mesylate (IM)

16003

Background: Although the response rates in CML associated with IM treatment is well-documented, little research exists on actual practice patterns with IM. The objective of this study is to document treatment changes in a large CML patient population using IM. Methods: Patients ≥ 18 years of age diagnosed with CML (ICD9 = 205.1) between 2000 and 2004 and treated with IM were selected from the Medstat MarketScan Commercial, Medicaid and Medicare Research Databases. Disease phase was defined using a CML specific disease staging algorithm and was assigned at the time of imatinib initiation. A treatment change is defined as evidence of any of the following: any dose increase ≥50 mg, CML treatment added to IM, or IM discontinuation. Summary statistics reported are medians and interquartile ranges (IQR). Results: Four hundred adult IM-treated CML patients (mean age, 56 years; 50% male) were included. 81% and 18% were in chronic phase (CP) and accelerated phase (AP), respectively; with 1% in remission. IM 400 mg was most frequently used regardless of CML phase or year of treatment. The daily starting dose was 400 mg in 305 (78%) patients, 600–799 mg in 34 (9%) patients, ≥ 800 mg in 17 (4%), and the remaining 39 (9%) started at doses < 400 mg. Median follow-up of treatment duration was 9 (IQR: 4.6, 18.9) months. 158 (40%) patients on IM had at least one treatment change, with rates higher in AP patients than in CP (52% vs. 37%). Dose increases were reported in 108 (27%) patients, 3 (<1%) had additional CML treatment, and 64 (16%) discontinued IM altogether. Conclusions: 40% of patients treated with IM had at least one treatment change. The frequency of treatment change increased with longer duration of IM treatment.

[Table: see text]

[Table: see text]

Prevalence and profile of females at risk of eating disorders in Singapore

INTRODUCTION

The objective of this study was to assess the prevalence of young females at risk of developing eating disorders (ED) and the associated socio-demographical variables.

METHODS

A set of self-administered questionnaires consisting of an Eating Attitude Test (EAT), an Eating Disorder Inventory (EDI) and a socio-demographical questionnaire was administered to 4,461 young females. Based on scores for EAT and/or EDI-drive for thinness (EDI-DT) subscale, subjects were categorised into either "normal" (NM) or "at risk" (AR) of ED.

RESULTS

Mean age of the subjects was 16.7 years (range 12-26 years). The ethnic composition was 78.8 percent Chinese, 11.7 percent Malay, 6.6 percent Indian and 3 percent other ethnic groups. Prevalence of AR was 7.4 percent (95 percent confidence interval [CI] 6.7-8.2 percent). Mean EAT and EDI-DT scores for AR were significantly higher than that of NM (EAT: mean difference is 22.1, 95 percent CI 20.7-23.4, p-value is less than 0.0001; EDI-DT: mean difference is 10.9, 95 percent CI 10.5-11.4, p-value is less than 0.0001). Female Malays constituted a significantly larger proportion of AR (20.6 percent) as compared to NM (10.9 percent). AR females are more likely to use Malay as a spoken language at home (prevalence rate ratio 1.70, p-value is 0.001) and to be better educated with completion of General Certificate of Education (GCE) "O" levels. However, the parents of AR females are likely to be less well educated (below GCE "A" levels).

CONCLUSION

The prevalence of females at risk of developing ED is 7.4 percent. Malay ethnic group, using Malay language at home and the educational levels of both the subjects and their parents appear to be associated with an increased risk for development of ED.

Pine dust, atopy and lung function: A cross-sectional study in sawmill workers

An increased risk of asthma symptoms has previously been shown in 772 pine sawmill workers. The aim of the current study was to assess the association between dust exposure, lung function and atopy. Subjects with (n = 59) and without (n = 167) asthma symptoms were randomly selected from the previous survey. Lung function and atopy were determined using spirometry and skin-prick tests, respectively. Inhalable dust levels were measured on the same day. The geometric mean dust concentration was 0.52 mg x m(-3). Exposure to dry but not to green dust was associated with asthma symptoms. Green dust was associated with atopic sensitisation, particularly against outdoor allergens; no association was found for dry dust. Forced vital capacity, forced expiratory volume in one second and peak expiratory flow were significantly lower in workers exposed to high levels of green dust (-350 mL, -260 mL and -860 mL x s(-1), respectively) and dry dust (-230 mL, -190 mL and -850 mL x s(-1), respectively). These associations were observed both in subjects with and without asthma symptoms. No associations with cross-shift changes in lung function were found. Exposure to green pine sawdust may be a risk factor for atopy. Both green and dry dust were associated with obstructive as well as restrictive pulmonary effects.

Measuring guided waves in long bones: modeling and experiments in free and immersed plates

Guided waves, consistent with the A0 Lamb mode, have previously been observed in bone phantoms and human long bones. Reported velocity measurements relied on line fitting of the observed wave fronts. Such an approach has limited ability to assess dispersion and is affected by interference by other wave modes. For a more robust identification of modes and determination of phase velocities, signal processing techniques using the fast Fourier transform (FFT) were investigated. The limitations of FFT because of spatial resolution were addressed to improve the precision of the measured modes. An inversion scheme was developed for determining the plate thickness from the measured velocity. Experiments were performed on free and immersed plates, mimicking bone without and with an overlying tissue. With group velocity filtering, modes could be identified reliably with precise phase velocities and thicknesses. These methods were essential for the immersed plates and they should lead to more reliable in vivo measurements.

Multi-locus candidate gene polymorphisms and risk of myocardial infarction: a population-based, prospective genetic analysis

BACKGROUND

Polymorphisms in candidate genes related to lipid metabolism, thrombosis, hemostasis, cell-matrix adhesion, and inflammation have been suggested clinically useful in risk assessment of cardiovascular disease.

METHODS

We evaluated a panel of 92 candidate gene polymorphisms, using a multiplex polymerase chain reaction-immobilized probe assay amongst 523 individuals who subsequently developed myocardial infarction (MI), and amongst 2092 individuals who remained free of reported cardiovascular disease over a mean follow-up period of 13.2 years.

RESULTS

Of the 92 polymorphisms tested, three that we previously reported on were associated with risk of MI, [pro12ala in the peroxisome proliferator activated-receptor gamma gene (odds ratio, OR = 0.75, P = 0.02); thr164ile in the beta-2 adrenergic receptor gene (OR = 0.14, P = 0.007); and ala23thr polymorphism in the eotaxin gene (OR = 1.87, P = 0.01)]. However, when adjusted for the other 89 polymorphisms evaluated, these findings were no longer statistically significant. Further, in contrast to reports from other investigators, we found little evidence for association of a C677T polymorphism in the 5,10-methylenetetrahydrofolate reductase gene, the angiotensin-I-converting enzyme 1 insertion/deletion polymorphism, a 4G/5G polymorphism in the serine/cysteine proteinase inhibitor-clade E-member 1 gene, the factor V Leiden mutation, the G20210A factor II mutation, a -455G>A polymorphism in the beta-fibrinogen gene, the cys112arg/arg158cys apolipoprotein E gene polymorphism, a gly460trp polymorphism in the alpha-adducin gene, and a -629C>A polymorphism in the cholesteryl ester transfer protein gene with risk of MI.

CONCLUSIONS

After correction for multiple comparisons, the addition of genetic information observed in the present study had little impact on risk prediction models for MI. The present investigation highlights the importance of replication and validation of findings from genetic association studies.

Noninvasive assessment of coronary stenosis

Invasive coronary angiography (ICA) has been the gold standard in the diagnosis of coronary artery disease (CAD) for a long time and angiographic procedures performed annually in the United States have steadily increased during the last 25 years. The unmatched temporal and spatial imaging resolution, the high level contrast between the coronary lumen and the adjacent structures, and the ability to concurrently perform percutaneous coronary interventions (PCI) are the technical advantages of coronary angiography. However, the isolated intraluminal imaging, the relatively high financial cost of the procedure, and the risks associated with catheterization may be limitations to its use. Moreover, a better selection of patients really in need of ICA and PCI is necessary since many patients referred for ICA are found not to have significant CAD. Therefore, a remarkable technical progress has been achieved by both cardiac magnetic resonance and cardiac computed tomography in this regard for the noninvasive detection of coronary stenoses.

HCHs and DDTs in sediment-dwelling animals from the Yangtze Estuary, China

HCHs and DDTs in sediment-dwelling animals including mollusks and crabs from the Yangtze Estuary were determined by GC-ECD. Levels of t-HCH were in the range of 1.2-5.5 ng g(-1) and averaged 3.5 ng g(-1) in mollusks, while t-DDT concentrations ranged from 26.0 to 68.8 ng g(-1), with a mean of 34.5 ng g(-1). In crabs t-HCH concentrations varied from 2.0 to 25.7 ng g(-1) and averaged 13.8 ng g(-1), whereas the concentrations of t-DDT were in the range of 1.5-24.8 ng g(-1) with a mean value of 5.9 ng g(-1). The HCHs and DDTs levels depend on geographical position and sources, showing the high levels at fresh water area in the estuary, such as XP, CM and LHK sites, and lower at brackish water area, such as FX site, and little difference between species. Results also indicate there was no significant relationship between t-HCH (t-DDT) concentrations and lipid contents both in mollusks and crabs because of non-equilibrium state under a specific estuarine dynamics; smaller individuals accumulated more HCHs and DDTs than larger individuals of mollusks at LHK site, showing different uptake rate for these pesticides; moreover, HCHs and DDTs levels were lower in female crab bodies than male crab bodies suggesting that the release of spawning. BSAFs (Biota- Sediment Accumulation Factors) from sediment-dwelling animals for HCHs and DDTs show a significant "one high with two low" and "one low with two high" effect in the Yangtze Estuary.

HCHs and DDTs in salt marsh plants (Scirpus) from the Yangtze estuary and nearby coastal areas, China

HCHs and DDTs in salt marsh plants taken from intertidal flats in the Yangtze estuary and coastal area in April and July 2002 were determined by GC-ECD. A significant seasonal effect was observed for HCHs and DDTs in sources and concentration levels in different sample types including above-ground tissues and roots as well as the whole plants and rhizospheric sediments. The results indicated that the concentration of t-HCH was higher in the above-ground tissues than in their roots in April; however, the partitioning of DDTs between contaminated sediments and the roots showed the higher concentrations of t-DDT in their roots. HCHs and DDTs concentration levels were higher in above-ground tissues than in roots in July. BCFs of HCHs and DDTs exhibited lower values with higher levels of contaminants in sediments, and higher values with lower levels in sediments.

Knowledge of blood pressure levels and targets in patients with coronary artery disease in the USA

Little is known about patient awareness of nationally recommended blood pressure targets, especially among patients with cardiac disease. To examine this issue, we interviewed 738 patients hospitalized with coronary artery disease to assess their knowledge of their systolic and diastolic blood pressure levels as well as corresponding national targets. We used bivariate and multivariate analyses to determine if any patient demographic or clinical characteristics were associated with blood pressure knowledge. Only 66.1% of patients could recall their own systolic and diastolic blood pressure levels. Only 48.9% of all patients could correctly name targets for these values. Knowledge of target blood pressure levels was particularly poor among patients who were female (odds ratio (OR) 0.69; 95% confidence interval (CI) 0.49-0.98), aged > or =60 years (OR 0.70, CI 0.51-0.97), without any college education (OR 0.48, CI 0.35-0.65), without a documented history of hypertension (OR 0.57, CI 0.39-0.84), and with known diabetes (OR 0.46, CI 0.33-0.66). Patients in the highest risk group, according to Joint National Committee guidelines stratification, were no more knowledgeable about their blood pressure levels and targets than lower risk patients. A significant proportion of patients hospitalized with coronary artery disease do not know their own blood pressure levels or targets. Current blood pressure education efforts appear inadequate, particularly for certain patient subgroups in which hypertension is an important modifiable risk factor.

Family-based association analysis implicates IL-4 in susceptibility to Kawasaki disease

Several compelling lines of evidence suggest an important influence of genetic variation in susceptibility to Kawasaki disease (KD), an acute vasculitis that causes coronary artery aneurysms in children. We performed a family-based genotyping study to test for association between KD and 58 genes involved in cardiovascular disease and inflammation. By analysis of a cohort of 209 KD trios using the transmission disequilibrium test, we documented the asymmetric transmission of five alleles including the interleukin-4 (IL-4) C(-589)T allele (P=0.03). Asymmetric transmission of the IL-4 C(-589)T was replicated in a second, independent cohort of 60 trios (P=0.05, combined P=0.002). Haplotypes of alleles in IL-4, colony-stimulating factor 2 (CSF2), IL-13, and transcription factor 7 (TCF7), all located in the interleukin gene cluster on 5q31, were also asymmetrically transmitted. The reported associations of KD with atopic dermatitis and allergy, elevated serum IgE levels, eosinophilia, and increased circulating numbers of monocyte/macrophages expressing the low-affinity IgE receptor (FCepsilonR2) may be related to effects of IL-4. Thus, the largest family-based genotyping study of KD patients to date suggests that genetic variation in the IL-4 gene, or regions linked to IL-4, plays an important role in KD pathogenesis and disease susceptibility.

Characterization of a 4-methylbenzoate-degrading methanogenic consortium as determined by small-subunit rDNA sequence analysis

A methanogenic consortium that degrades 4-methylbenzoate (MBA) as the sole carbon and energy source was successfully enriched in an upflow anaerobic sludge bed bioreactor and studied. Electron microscopic observation showed that long rods with a distinct collar feature resembling Desulfomonile tiedjei rods were the predominant population, and that these rods formed a close spatial orientation with Methanobrevibacter-like bacteria. In addition, thin filaments and bamboo-shaped filaments that highly resembled the acetoclastic Methanosaeta were also frequently observed. A 16S rDNA clone library was constructed for the domain Bacteria, and 20 sequence types or operational taxonomic units (OTUs) were found out of 139 clones screened. Phylogenetic analysis classified these 20 nearly full-length OTUs into the delta (50.3% of total clones) and gamma (4.3%) subdivisions of the division Proteobacteria, the green non-sulfur bacteria subdivision I (7.2%), Cytophagales (7.2%), Planctomycetes (5.7%), gram-positive low G + C group (8.6%), candidate divisions OP8, OP10 and OP11 (9.3%), and a novel candidate division MBA1 (7.2%) that had an interdivisional sequence similarity less than 75%. However, only 3 OTUs had a sequence similarity higher than 90% to known isolates or environmental 16S rDNA clones, suggesting that the microbial community was diversified and largely unidentified. In particular, those 8 OTUs found in the delta-Proteobacteria were either clustered into novel groups or showed a low sequence similarity to closely related bacteria. It is highly possible that the delta-Proteobacteria were the long rods with a distinct collar feature observed microscopically, and together with the methanogens were mainly responsible for the syntrophic degradation of MBA. The unique and novel microbial populations identified explained the requirement of a long start-up period of up to 426 d for the MBA-degrading consortium.