Assessment of physiological barriers to nutrition following critical illness

BACKGROUND & AIMS

Nutrition may be important for recovery from critical illness. Gastrointestinal dysfunction is a key barrier to nutrition delivery in the Intensive Care Unit (ICU) and metabolic rate is elevated exacerbating nutritional deficits. Whether these factors persist following ICU discharge is unknown. We assessed whether delayed gastric emptying (GE) and impaired glucose absorption persist post-ICU discharge.

METHODS

A prospective observational study was conducted in mechanically ventilated adults at 3 time-points: in ICU (V1); on the post-ICU ward (V2); and 3-months after ICU discharge (V3); and compared to age-matched healthy volunteers. On each visit, all participants received a test-meal containing 100 ml of 1 kcal/ml liquid nutrient, labelled with 0.1 g ¹³C-octanoic acid and 3 g 3-O-Methyl-glucose (3-OMG), and breath and blood samples were collected over 240min to quantify GE (gastric emptying coefficient (GEC)), and glucose absorption (3-OMG concentration; area under the curve (AUC)). Data are mean ± standard error of the mean (SEM) and differences shown with 95% confidence intervals (95%CI).

RESULTS

Twenty-six critically ill patients completed V1 (M:F 20:6; 62.0 ± 2.9 y; BMI 29.8 ± 1.2 kg/m²; APACHE II 19.7 ± 1.9), 15 completed V2 and eight completed V3; and were compared to 10 healthy volunteers (M:F 6:4; 60.5 ± 7.5 y; BMI 26.0 ± 1.0 kg/m²). GE was significantly slower on V1 compared to health (GEC difference: -0.96 (95%CI -1.61, -0.31); and compared to V2 (-0.73 (-1.16, -0.31) and V3 (-1.03 (-1.47, -0.59). GE at V2 and V3 were not different to that in health (V2: -0.23 (-0.61, 0.14); V3: 0.10 (-0.27, 0.46)). GEC: V1: 2.64 ± 0.19; V2: 3.37 ± 0.12; V3: 3.67 ± 0.10; health: 3.60 ± 0.13. Glucose absorption (3-OMG AUC_0-240) was impaired on V1 compared to V2 (-37.9 (-64.2, -11.6)), and faster on V3 than in health (21.8 (0.14, 43.4) but absorption at V2 and V3 did not differ from health. Intestinal glucose absorption: V1: 63.8 ± 10.4; V2: 101.7 ± 7.0; V3: 111.9 ± 9.7; health: 90.7 ± 3.8.

CONCLUSION

This study suggests that delayed GE and impaired intestinal glucose absorption recovers rapidly post-ICU. This requires further confirmation in a larger population. The REINSTATE trial was prospectively registered at www.anzctr.org.au.

TRIAL ID

ACTRN12618000370202.

Abstract PD3-07: A phase II pre-surgical trial of lapatinib for the treatment of women with HER2 positive or EGFR positive ductal carcinoma in situ

Background: Estrogen receptor (ER)-negative tumors and human epidermal growth factor 2-Neu (HER2) positive breast cancers are known to be more clinically aggressive subtypes of breast cancer and account for 30% of all breast cancers. Women with HER2 + breast cancers, whether ER+ or ER -, require cytotoxic chemotherapy with a HER2-targeting agent, and often have adverse outcomes. Thus, preventive agents are needed to reduce the incidence of these subtypes of aggressive breast cancer. Lapatinib, a dual tyrosine kinase inhibitor, inhibits epidermal growth factor receptors (EGFR) and HER2 kinases and has shown to decrease breast cell proliferation in invasive breast cancer and adjacent premalignant lesions. Therefore, we conducted a multi-institutional randomized Phase II clinical trial to study the effects of the signal transduction inhibitor lapatinib in women with HER2-positive or EGFR-positive ductal carcinoma in situ (DCIS).

Methods: Randomized participants received either lapatinib (750mg, 1000mg, or 1500mg) or placebo daily for 2-6 weeks prior to their surgery. After minimal accrual, the trial was later amended to lapatinib 1000mg or placebo. Pre-treatment breast tissue was obtained from initial diagnostic core biopsy and post-treatment breast tissue was obtained from surgical excision specimen. Blood was obtained prior to surgery to assess serum lapatinib level. Participants kept a daily symptom assessment log and had a cardiac assessment at baseline and prior to surgery. Patients were instructed to take drug up to and including the day before surgery. The dual primary endpoint for this study was change in proliferation in pre- versus post-treatment biopsies between the two treatment arms, as measured by Ki67 as well as toxicity assessment. Secondary endpoints included incidence of DCIS at surgery and modulation of tissue biomarker expression in growth factor receptors (EGFR, ErbB2); phosphorylated growth factor receptor (phospho-ErbB2); signal transduction markers (MAPK, phospho-MAPK); hormone receptors (ER, PR); and p27.

Results:Twenty-two women (mean age: 51; range: 32-66) with HER2+ or EGFR+ DCIS were treated with lapatinib (1,000 or 1,500 mg) or placebo for 2–6 weeks prior to surgical excision. Ki67 expression was significantly decreased in the lapatinib treatment arms compared to placebo (p=0.0122). Diarrhea, fatigue, and skin reactions were notable adverse events that occurred predominately in the lapatinib arm compared to placebo. No grade 3 or 4 events related to the study drug were noted during the study. No changes were noted in cardiac function. DCIS was present in all surgical specimens in both arms. Invasive breast cancer was noted in 1 patient on lapatinib 1000mg and 3 patients on placebo. No statistically significant changes were noted in signal transduction biomarkers

Conclusion:These results demonstrate the effectiveness of lapatinib in reducing proliferation in women with EGFR+ or HER2+ DCIS. Even low-grade toxicities can deter use of an agent in the prevention setting. This and the lack of a risk model for HER2+ and triple negative breast cancer make the development of larger scale clinical prevention trials of lapatinib for the prevention a challenge.

Citation Format: Thomas PS, Contreras A, Pruthi S, Krontiras H, Rimawi M, Garber J, Wang T, Hilsenbeck SG, Vornik LA, Gilmer T, Friedman R, Heckman-Stoddard BM, Dunn B, Kuerer H, Brown PH. A phase II pre-surgical trial of lapatinib for the treatment of women with HER2 positive or EGFR positive ductal carcinoma in situ [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr PD3-07.

EU/US/CTAD Task Force: Lessons Learned from Recent and Current Alzheimer's Prevention Trials

At a meeting of the EU/US/Clinical Trials in Alzheimer's Disease (CTAD) Task Force in December 2016, an international group of investigators from industry, academia, and regulatory agencies reviewed lessons learned from ongoing and planned prevention trials, which will help guide future clinical trials of AD treatments, particularly in the pre-clinical space. The Task Force discussed challenges that need to be addressed across all aspects of clinical trials, calling for innovation in recruitment and retention, infrastructure development, and the selection of outcome measures. While cognitive change provides a marker of disease progression across the disease continuum, there remains a need to identify the optimal assessment tools that provide clinically meaningful endpoints. Patient- and informant-reported assessments of cognition and function may be useful but present additional challenges. Imaging and other biomarkers are also essential to maximize the efficiency of and the information learned from clinical trials.

Abstract OT3-3-01: A multicenter phase II study of docosahexaenoic acid (DHA) in triple negative breast cancer (TNBC) survivors

Background: The development of effective chemopreventive strategies to reduce the risk of TNBC, is a critical unmet need. Obesity is associated with a chronic inflammatory condition in the white adipose tissue of the breast, characterized microscopically by crown-like structures of the breast (CLS-B). The presence and extent of these lesions is associated with a series of proinflammatory mediators, including tumor necrosis factor-α (TNF-α), cyclooxygenase-2 (COX-2), interleukin-1β (IL-1β) and aromatase. Importantly these proinflammatory mediators are known to be involved in breast carcinogenesis. In translational studies to date, the strongest correlations have been seen between CLS-B and TNF-α. Therefore, we aim to evaluate whether treatment with a dietary supplement, DHA, an omega-3 fatty acid, with potent effects on TNF-α, can decrease obesity-related breast inflammation in women.

Trial design: This is a randomized phase II placebo-controlled, double-blinded study of DHA in overweight/obese patients (pts), defined as body mass index (BMI) ≥25 with a history of TNBC. Pts will receive DHA or placebo twice daily for 24 weeks and will undergo core biopsies from normal (non-irradiated contralateral) breast tissue before and after the treatment to determine whether DHA can decrease obesity-related breast inflammation.

Eligibility: Inclusion criteria: 1) Age ≥ 18. 2) BMI ≥ 25. 3) Completed treatment for stage I-III TNBC ≥ 6 months prior. 4) No clinical evidence of disease. 5) Adequate accessible breast tissue for pre- and post- treatment biopsy, consisting of one breast unaffected by invasive cancer, which has not been radiated or surgically augmented. 6) Adequate organ and bone marrow function. 7) ECOG status ≤2. Exclusion criteria: 1) DHA supplementation. 2) Aspirin/NSAID use in the month preceding and during the trial. 3) Therapeutic anticoagulation. 4) Regular use of statins, steroids, or immunomodulators.

Specific aims: The primary objective is to determine whether treatment with DHA for 24 weeks at 1,000 mg twice daily as compared to placebo reduces normal breast tissue levels of TNF-α in overweight/obese pts with a history of TNBC. The secondary objective is to evaluate the effect of DHA on the change from baseline in levels of the following tissue biomarkers: COX-2, IL-1β, aromatase, and CLS-B. Exploratory endpoints include assessment of age as a predictor of CLS-B and inflammatory biomarkers and the evaluation of red blood cell fatty acid levels as a surrogate of DHA compliance.

Statistical methods: Percent change in TNF-α mRNA levels in normal breast tissue between DHA and placebo arm will be compared using two-sample t-test. If normality assumptions are violated, a two-sample Wilcoxon rank-sum test will be used. With 30 subjects in each arm, we will have 80% power to detect effect size as small as 0.74 at 0.05 significance level using a two-sided, two-sample, Student t-test.

Accrual: A total of 60 evaluable pts will be enrolled. Assuming a 10% dropout rate and 10% non-evaluable rate, up to 76 participants will be randomized in this study. This trial is currently enrolling pts.

Contact information: For more information on this trial, please visit clinicaltrials.gov (NCT01849250) or contact Ayca Gucalp MD (gucalpa@mskcc.org).

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr OT3-3-01.

Abstract P1-09-07: Topical 4-OHT trial in women with DCIS of the breast: report of plasma and breast tissue concentration of tamoxifen metabolites

Background: Earlier studies have shown that 1–2mg of 4-hydroxytamoxifen (4–OHT) gel applied to the breast skin reduced cell proliferation in estrogen receptor (ER) positive invasive cancers to a similar degree as oral tamoxifen (TAM), with significantly lower plasma levels. We now report results of a Phase IIB pre-surgical window trial of women with DCIS, designed to obtain pilot data in early lesions. Our ultimate goal is to develop transdermal 4-OHT as an alternative to oral TAM for women at high risk for breast cancer and those with DCIS. The study was closed early because the manufacturer discontinued the drug supply, but remains blinded until all biomarker analysis is complete. Here we report the plasma and breast adipose tissue concentration of TAM metabolites from the topical 4-OHT gel group (4 mg) in comparison with the oral TAM group (20mg).

Methods: Women with DCIS were enrolled, and randomized to 4-OHT gel (4mg/day, 2mg per breast, E: Z isomers = 1:1,) or to oral (Z) TAM (20mg/day) for 4–10 weeks before surgery. Blood was collected on the day of surgery, and breast adipose tissue was collected at surgery. There were a total of 22 patients with matched blood and breast adipose tissue. The concentration of TAM metabolites in plasma and breast tissue was determined with liquid chromatography/tandem mass spectrometry. We assumed that the subjects with detectable N-desmethyl TAM (NDT) in plasma belong to the oral TAM group because NDT is not a product of 4-OHT metabolism. Under this assumption, 13 subjects were categorized into oral TAM group, and 9 subjects into the topical 4-OHT group. Wilcoxon rank-sum test was used for statistical analysis.

Results: The results are shown in the table. The concentration is presented as mean ± SD; the lowest quantitation limit (LQL) was 1 ng/mL for plasma, and 3 ng/g for tissue. TAM and its metabolites were found in the plasma of the presumed oral TAM group, with high levels of TAM and NDT. In the presumed 4-OHT gel group, only (Z) 4-OHT was found in the plasma although both (E) and (Z) forms were applied. The mean plasma level of 4-OHT in the gel group was 70% lower than the mean of 4-OHT in the oral TAM group (p = 0.004). In breast tissue, similar amounts of (E) and (Z) forms of 4-OHT were found in the 4-OHT gel group, with the (Z) 4-OHT level being equivalent to that in the oral TAM group (p = 0.48). Endoxifen was only found in the oral TAM group. We saw no evidence of further metabolic transformation of 4-OHT in the breast following topical administration.

Electrically conductive, immobilized bioanodes for microbial fuel cells

The power densities of microbial fuel cells with yeast cells as the anode catalyst were significantly increased by immobilizing the yeast in electrically conductive alginate electrodes. The peak power densities measured as a function of the electrical conductivity of the immobilized electrodes show that although power increases with rising electrical conductivity, it tends to saturate beyond a certain point. Changing the pH of the anode compartment at that point seems to further increase the power density, suggesting that proton transport limitations and not electrical conductivity will limit the power density from electrically conductive immobilized anodes.

Incorporation of Polyaniline Into a Silica Gel Via the Sol-Gel Technique

The sol-gel process has been used to incorporate a conjugated polymer, polyaniline, in silica gel. The emeraldine base form of the polymer is partially solubility in aprotic polar solvents which are compatible with the sol. The effect of sol environment on the emeraldine base form of polyaniline was investigated. The soluble emeraldine base form is maintained at pH ≥ 2.4 enabling good optical quality gels to be synthesized. The type of alkoxysilane and the water ratio used in preparing the sol influence the solubility of the emeraldine base.

The Optical Behavior of Organic and Organometallic Molecules in Sol-Gel Matrices

The low temperatures involved in sol-gel processing have enabled organic and organometallic molecules to be incorporated in gel matrices. These molecules serve as optical probes to characterize gel chemistry and structure. The present paper describes the use of luminescence spectroscopy to detail matrix rigidity effects and protonation/deprotonation reactions during the sol-gel transition and subsequent aging processes. In separate experiments, the addition of a laser dye, rhodamine 6G, has enabled us to demonstrate lasing and optical gain in a silica gel.

MorphÒlogy and Properties of Vanadium Oxide Xerogels and Aerogels

The high redox potential and ion insertion properties of vanadium pentoxide have made this material a viable cathode for secondary lithium batteries. The use of sol-gel methods to synthesize vanadium pentoxide and other transition metal oxides has been well studied as the technique represents a relatively simple approach for preparing thin films and powders. Although it is well known that sol-gel processing may be used to prepare high surface area aerogels, the research on transition metal oxides has been largely limited to xerogels. The present paper compares the properties, structures and morphologies of vanadate xerogels and aerogels.

Advances in Dye-Doped Sol-Gel Lasers

The sol-gel process is a solution synthesis technique which provides a low temperature chemical route for the preparation of rigid transparent matrices. A number of laser dyes have been incorporated in different sol-gel matrices and tunable laser action has been demonstrated with these materials. This paper extends the sol-gel laser field into two significant areas, infrared dyes and pyrromethenes. The work with the tricarbocyanine dyes shows the versatility of sol-gel chemistry as organic modifications produce a favorable environment for the dye molecules. The results with the pyrromethene system show a considerable increase in output energy and offer the promise of longer laser lifetimes.

Preparation and Properties of Porous Bismuth Films

The use of chemical solution routes to form inorganic thin films is a relatively new method which represents an alternative to vapor phase routes. The present study involves the use of a chemical solution route, the decomposition of metal carboxylates, to prepare bismuth thin films of controlled porosity. Such morphologies offer the opportunity to disrupt phonon transport without greatly affecting electrical conductivity and bismuth represents a well known system in which to investigate these effects. Porous bismuth thin films have been prepared using bismuth 2-ethylhexanoate (Bi[OOCCH(C2H5)C4H9]3) as the precursor in a solvent of 2-methyl- 1-propanol. The solution is deposited on glass, Kapton, silicon, alumina or magnesia substrates by spin coating and heated to between 250 – 300°C in hydrogen. Heat treatment temperature and time are important for controlling film microstructure as both pore volume (25 to 50%) and preferred orientation depend upon heat treatment conditions. Bismuth films (62 nm thick) with 32% porosity exhibit conductivities in the range of 150 S/cm with Seebeck coefficients comparable to that of bulk materials.

Proteins Encapsulated in Porous Sol-Gels: Biomolecules as Pore Structure Templates

Porous inorganic SiO2 glasses obtained by the sol-gel route represent a unique matrix for encapsulation of biomolecules wherein the pores act as enclosures for high molecular weight proteins. These hybrid materials are characterized by a pore-biomolecule interface between the pore walls and the protein surface. As a specific model protein, cytochrome c (cyt c) is used to elucidate the nature of physical and chemical interactions between the pores of the matrix and the protein. Evidence from optical absorption, and resonance Raman (RR) spectroscopy methods indicates that the dopant protein alters the structural features of the pore walls. The optical and vibrational measurements strongly suggest that the pores that contain the trapped protein undergo little or no structural change during aging and drying as compared to protein-free pores. Vibrational RR analysis of the trapped cyt c also suggests that the protein resides in a pore where the pore dimensions conform to the shape of the protein. The results indicate that noncovalent interactions between the surface of the protein and the pore walls govern the dynamics of pore formation during gelation and individual biomolecules act as structural templates to design local pore structure.

Microarray karyotyping of maltose-fermenting Saccharomyces yeasts with differing maltotriose utilization profiles reveals copy number variation in genes involved in maltose and maltotriose utilization

AIMS

We performed an analysis of maltotriose utilization by 52 Saccharomyces yeast strains able to ferment maltose efficiently and correlated the observed phenotypes with differences in the copy number of genes possibly involved in maltotriose utilization by yeast cells.

METHODS AND RESULTS

The analysis of maltose and maltotriose utilization by laboratory and industrial strains of the species Saccharomyces cerevisiae and Saccharomyces pastorianus (a natural S. cerevisiae/Saccharomyces bayanus hybrid) was carried out using microscale liquid cultivation, as well as in aerobic batch cultures. All strains utilize maltose efficiently as a carbon source, but three different phenotypes were observed for maltotriose utilization: efficient growth, slow/delayed growth and no growth. Through microarray karyotyping and pulsed-field gel electrophoresis blots, we analysed the copy number and localization of several maltose-related genes in selected S. cerevisiae strains. While most strains lacked the MPH2 and MPH3 transporter genes, almost all strains analysed had the AGT1 gene and increased copy number of MALx1 permeases.

CONCLUSIONS

Our results showed that S. pastorianus yeast strains utilized maltotriose more efficiently than S. cerevisiae strains and highlighted the importance of the AGT1 gene for efficient maltotriose utilization by S. cerevisiae yeasts.

SIGNIFICANCE AND IMPACT OF THE STUDY

Our results revealed new maltotriose utilization phenotypes, contributing to a better understanding of the metabolism of this carbon source for improved fermentation by Saccharomyces yeasts.

Quantitative amino acid analysis

Colorimetric dye-binding assays are often used to determine protein concentration, however, many proteins do not bind dyes in the same way as the proteins normally used as standards, making quantitation by those techniques difficult. This unit describes the information that can be derived from quantitative amino acid analysis (including precise determination of protein concentration), presents some details on sample preparation, and gives examples of the calculations that are needed.

Preparation of protein extracts from yeast

Three protocols are presented for preparing protein extracts; they differ primarily in the way the cells are broken. In the basic protocol, cells are enzymatically converted to spheroplasts, which are then lysed by a combination of osmotic shock and Dounce homogenization. A support protocol for isolating intact nuclei by differential centrifugation is also presented. An alternate protocol describes mechanical breakage of cells by vortexing in the presence of glass beads. In a second alternate protocol, growing cells are frozen immediately in liquid nitrogen and then lysed by grinding in an industrial-strength blender in the presence of liquid nitrogen.

Spatial trends and factors affecting variation of organochlorine contaminants levels in Canadian Arctic beluga (Delphinapterus leucas)

Organochlorine pesticides and PCBs were analysed in blubber from beluga (Delphinapterus leucas), or white whales, collected at 15 sites in the Canadian Arctic between 1993 and 2001. The objective of the study was to define and interpret the spatial trends of major organic contaminants in northern beluga in terms of sources and transport pathways, and the biological factors influencing accumulation. When compared on a lipid weight basis, the concentrations of beta-HCH, cis-CHL and SigmaCHL, cis-nonachlor, heptachlor epoxide and p,p'-DDT were significantly higher in males than females at all five sites in the eastern Arctic where the two sexes were harvested. The differences were attributed to losses from the females during fetal development and lactation as reported in previous studies. Major compounds increased with age in males at most sites, however the lack of a significant increase with age at some sites was in part due to high organochlorine concentrations in young year classes (2-5 years), particularly at eastern sites such as Iqaluit and Pangnirtung. Lower concentrations of SigmaHCH and SigmaDDT compounds in young males in 2001 relative to 1995 at Hendrickson Island could be due to declining levels in the environment, changes in the diet, or differences in organochlorine loads transferred from the female after birth. Age-corrected least square mean concentrations in males showed significantly higher levels of many compounds, such as p,p'-DDE and SigmaCHB, at south Baffin Island sites than those in the west. Two notable exceptions were HCBz and beta-HCH which were higher in the west. Methoxyclor was detected in males at Sanikiluaq (58 ng g-1) and in both sexes at Kimmirut, but at no other sites. Principal component analysis grouped the 16 sites into five major groupings based on the similarity of normalised organochlorine pesticide and PCB levels. Sites from the western Arctic were grouped by higher proportions of HCBz, beta-HCH and gamma-HCH and higher chlorinated PCBs. Endosulfan and alpha-HCH comprised a larger proportion of total organochlorine residues in the northern Hudson Bay sites, while methoxychlor, chlordane compounds and octachlorobiphenyls were enriched at Sanikiluaq in eastern Hudson Bay. The analysis showed that the relative amounts of several key compounds are similar in the beluga stocks over large spatial areas (i.e. eastern versus western sites), however, some stocks have distinct fingerprints which can be used to differentiate them from adjacent stocks. Ratios of major HCH isomers largely corresponded with air and surface water measurements conducted during the 1990s, but low alpha-/beta- and alpha-/gamma-HCH ratios in all three western Arctic collections indicate rapid losses of the alpha-isomer from the food web, proportionately higher beta- and gamma-isomers in the Beaufort Sea, or a combination of the two processes. Chlordane residue patterns generally correspond to those from previous studies, however, interpretation of spatial trends are difficult due to the aging of the probable sources in the south, possible atmospheric input from new sources and complex transport pathways.

Concentrations of mercury in tissues of beluga whales (Delphinapterus leucas) from several communities in the Canadian Arctic from 1981 to 2002

Beluga whales have been hunted for food by Native People in the Canadian Arctic since prehistoric time. Here we report the results of analyses of total mercury in samples of liver, kidney, muscle and muktuk from collections over the period 1981-2002. We compare these results with human consumption guidelines and examine temporal and geographic variation. Liver has been analyzed more frequently than other organs and it has been used as the indicator organ. Mercury accumulates in the liver of the whales over time so that the whale ages are usually linked statistically to their levels of mercury in liver. Virtually all the samples of 566 animals analyzed contained mercury in liver at concentrations higher than the Canadian consumption guideline of 0.5 microg g-1 (wet weight) for fish. (There is no regulatory guideline for concentrations in marine mammals in Canada.) Samples from locations in the Mackenzie Delta in the western Canadian Arctic and from Pangnirtung in the eastern Canadian Arctic were obtained more often than from other location and these offered the best chances to determine whether levels have changed over time. Statistical outlier points were removed and the regressions of (ln) mercury in liver on age were used to calculate the level of mercury in whales of age 13.1 years in order to compare age-adjusted levels at different locations. These age-adjusted levels and also the slopes of regressions suggested that levels have increased in the Mackenzie Delta over the sampling period although not in a simple linear fashion. Other locations had fewer collections, generally spread over fewer years. Some of them indicated differences between sampling times but we could not establish whether these differences were simply temporal variation or whether they were segments of a consistent trend. For example, the levels in whales from Arviat were considerably higher in 1999 than in 1984 but we have only two samples. Similarly, samples from Iqaluit in 1994 exceeded considerably those in 1993 and the interval seems too short to reflect any regional temporal trend and more likely represent an extreme case of year-to-year variation. Previous analyses of data from geographically distinct groups had suggested that whales in the western Canadian Arctic had higher levels of mercury than those from the eastern Canadian Arctic. The present analysis suggests that such regional differences have diminished and are no longer statistically significant. No site has indicated significant decreases in more recent samples. The levels of total mercury in the most analyzed organs fell in the order of liver (highest levels), kidney, muscle and muktuk (lowest level). While muktuk had the lowest level of the organs most frequently analyzed, it is the preferred food item from these whales and it still exceeded the consumption guideline in most instances.

A MEMS based amperometric detector for E. coli bacteria using self-assembled monolayers

We developed a system for amperometric detection of Escherichia coli (E. coli) based on the integration of microelectromechanical systems (MEMS), self-assembled monolayers (SAMS), DNA hybridization, and enzyme amplification. Using MEMS technology, a detector array was fabricated which has multiple electrodes deposited on a Si wafer and was fully reusable. Using SAMs, a monolayer of the protein streptavidin was immobilized on the working electrode (Au) surface to capture rRNA from E. coli. Three different approaches can be used to immobilize streptavidin onto Au, direct adsorption of the protein on bare Au, binding the protein to a biotinylated thiol SAM on Au, and binding the protein to a biotinylated disulfide monolayer on Au. The biotinylated thiol approach yielded the best results. High specificity for E. coli was achieved using ssDNA-rRNA hybridization and high sensitivity was achieved using enzymatic amplification with peroxidase as the enzyme. The analysis protocol can be conducted with solution volumes on the order of a few microliters and completed in 40 min. The detection system was capable of detecting 1000 E. coli cells without polymerase chain reaction with high specificity for E. coli vs. the bacteria Bordetella bronchiseptica.

Long-term results of pulmonary balloon valvulotomy in adult patients

BACKGROUND AND AIM OF THE STUDY

The study aim was to define the long-term outcome of pulmonary balloon valvulotomy (PBV) in adult patients.

METHODS

PBV was performed in 87 patients (46 females, 41 males; mean age 23+/-9 years; range: 15-54 years) with congenital pulmonary valve stenosis (PS). Intermediate follow up catheterization (mean 14.6+/-5.0; range: 6-24 months) was performed after PBV in 53 patients. Clinical and Doppler echocardiography examinations were carried out annually in 82 patients (mean 8.0+/-3.9; range: 2-15 years).

RESULTS

There were no immediate or late deaths. The mean catheter peak pulmonary gradient (PG) before and immediately after PBV, and at intermediate follow up was 105+/-39, 34+/-26 (p <0.0001) and 17+/-14 (p <0.0001) mmHg, respectively. The corresponding values for right ventricular (RV) pressure were 125+/-38, 59+/-21 (p <0.0001) and 42+/-12 (p <0.0001) mmHg, respectively. The infundibular gradients immediately after PBV and at intermediate follow up were 31+/-23 and 14+/-9 mmHg (p <0.0001), whilst cardiac index improved from 2.68+/-0.73 to 3.1+/-0.4 l/min/m2 (p <0.05) at intermediate follow up. Doppler PG before PBV and at intermediate and long-term follow up were 91+/-33 (range 36-200) mmHg, 28+/-12 (range 10-60) mmHg (p <0.0001) and 26+/-11 mmHg (p = 0.2), respectively. New pulmonary regurgitation (PR) was noted in 21 patients (25%) after PBV. Five patients (6%) with a suboptimal result (immediate valve gradient > or =30 mmHg) developed restenosis and underwent repeat valvulotomy 6-12 months later using a larger balloon, and with satisfactory outcome. Moderate to severe tricuspid regurgitation (TR) in seven patients regressed after PBV.

CONCLUSION

The long-term results of PBV in adults are excellent, with regression of concomitant, severe infundibular stenosis and/or severe TR. Hence, PBV should be considered as the treatment of choice for adult patients with PS.

Phylogenetic diversity and position of the genus Campylobacter

RNA sequence analysis has been used to examine the phylogenetic position and structure of the genus Campylobacter. A complete 5S rRNA sequence was determined for two strains of Campylobacter jejuni and extensive partial sequences of the 16S rRNA were obtained for several strains of C. jejuni and Wolinella succinogenes. In addition limited partial sequence data were obtained from the 16S rRNAs of isolates of C. coli, C. laridis, C. fetus, C. fecalis, and C. pyloridis. It was found that W. succinogenes is specifically related to, but not included, in the genus Campylobacter as presently constituted. Within the genus significant diversity was noted. C. jejuni, C. coli and C. laridis are very closely related but the other species are distinctly different from one another. C. pyloridis is without question the most divergent of the Campylobacter isolates examined here and is sufficiently distinct to warrant inclusion in a separate genus. In terms of overall position in bacterial phylogeny, the Campylobacter/Wolinella cluster represents a deep branching most probably located within an expanded version of the Division containing the purple photosynthetic bacteria and their relatives. The Campylobacter/Wolinella cluster is not specifically includable in either the alpha, beta or gamma subdivisions of the purple bacteria.

The pursuit of excellence is not optional in the voluntary sector, it is essential

This paper outlines the continuous improvement journey of a voluntary organisation. The significant level of organisational growth and improving quality of services described is clearly linked to the organisation's commitment to improvement. One of the approaches used in adopting a total quality culture was the EFQM model, specifically interpreted for the voluntary sector. Until recently such an approach would have been considered alien to the sector, not least because of its origins in the business community. This article contradicts this assumption. Issues addressed include how the improvement process is driven, the use of performance measurement, external verification and the difficulties in accessing sector appropriate benchmark data. It is suggested that the pursuit of excellence is no longer optional for the voluntary sector, it is essential.

Efficacy of topical phenol decontamination strategies on severity of acute phenol chemical burns and dermal absorption: in vitro and in vivo studies in pig skin

Pure phenol is colorless and used in the manufacture of phenolic resins, plastics, explosives, fertilizers, paints, rubber, textiles, adhesives, pharmaceuticals, paper, soap, and wood preservatives. The purpose of this study was to compare the efficacy of several phenol decontamination strategies following dermal exposure using the pig as a model for human exposure, and then assess the effect of the two best treatments on phenol absorption in the isolated perfused porcine skin flap (IPPSF). Six anesthetized Yorkshire pigs were exposed to 89% aqueous phenol for 1 min using Hilltop chambers (10 skin sites/pig; 400 microl/site). Exposure to phenol was followed by one of 10 different decontamination procedures: 1-, 5-, 15-, and 30-min water wash; Ivory soap solution; polyethylene glycol (PEG 400); PEG 400/industrial methylated spirits (IMS); PEG 400/ethanol (EtOH); polyvinyl pyrrolidone (PVP)/70% isopropanol (IPA); and 70% IPA. For each of the last five strategies, 1-min treatment washes were repeatedly alternated with 1-min water washes for a total of 15 min. Evaluation was based on scoring of erythema, edema, and histological parameters such as intracellular and intercellular epidermal edema, papillary dermal edema, perivascular infiltrates, pyknotic stratum basale cells, and epidermal-dermal separation. It was concluded that PEG 400 and 70% IPA were superior to the other treatments investigated and equally efficacious in the reduction of phenol-induced skin damage. In addition, phenol absorption was assessed utilizing the two most effective in vivo treatments in the IPPSF. The assessment of percutaneous absorption of phenol found the PEG 400, 70% IPA, and 15-min water treatments significantly (P < 0.05) reduced phenol absorption relative to no treatment.

Effect of transpulmonary pressure on airway diameter and responsiveness of immature and mature rabbits

We previously demonstrated that airway responsiveness is greater in immature than in mature rabbits; however, it is not known whether there are maturational differences in the effect of transpulmonary pressure (Ptp) on airway size and airway responsiveness. The relationship between Ptp and airway diameter was assessed in excised lungs insufflated with tantalum powder. Diameters of comparable intraparenchymal airway segments were measured from radiographs obtained at Ptp between 0 and 20 cmH(2)O. At Ptp > 8 cmH(2)O, the diameters were near maximal in both groups. With diameter normalized to its maximal value, changing Ptp between 8 and 0 cmH(2)O resulted in a greater decline of airway caliber in immature than mature airways. The increases in lung resistance (RL) in vivo at Ptp of 8, 5, and 2 cmH(2)O were measured during challenge with intravenous methacholine (MCh: 0.001-0.5 mg/kg). At Ptp of 8 cmH(2)O, both groups had very small responses to MCh and the maximal fold increases in RL did not differ (1.93 +/- 0.29 vs. 2.23 +/- 0.19). At Ptp of 5 and 2 cmH(2)O, the fold increases in RL were greater for immature than mature animals (13.19 +/- 1.81 vs. 3.89 +/- 0.37) and (17.74 +/- 2.15 vs. 4.6 +/- 0.52), respectively. We conclude that immature rabbits have greater airway distensibility and this difference may contribute to greater airway narrowing in immature compared with mature rabbits.

Long-term effects of balloon angioplasty on systemic hypertension in adolescent and adult patients with coarctation of the aorta

AIMS

To define the long-term effect of balloon angioplasty of aortic coarctation on hypertension, in adolescent and adult patients.

METHODS

Balloon angioplasty of discrete, native aortic coarctation was performed on 50 patients (34 male) aged 23+/-8 (mean+/-standard deviation) years. In 42 of these patients cardiac catheterization and angiography were repeated 1 year later, and on the basis of sphygmomanometric blood pressure determination at that time, they were divided into 31 patients (group A) with normalized blood pressure and 11 patients (group B) who still needed antihypertensive medication. Both groups were followed annually thereafter for 12-123 (66+/-37) months.

RESULTS

Coarctation gradient values before, immediately after and 1 year after angioplasty were 69+/-24 mmHg, 12+/-8 mmHg (P<0.001) and 7+/-6 mmHg. The corresponding systolic blood pressure values were 165+/-17 mmHg, 128+/-12 mmHg (P<0.001) and 115+/-10 mmHg (P<0.001) in group A; 182+/-21 mmHg, 141+/-24 mmHg (P<0.001) and 134+/-18 mmHg (P<0.001) in group B. Echocardiographic left ventricular mass index before angioplasty and at follow-up was 130+/-31 g x m-2 and 105+/-23 g x m-2 in group A; 157+/-38 g x m-2 and 132+/-35 g x m-2 in group B (P<0.001 for both comparisons).

CONCLUSION

Normalization of blood pressure without medication occurred in 74% of patients after angioplasty for aortic coarctation, with subsequent long-term regression of left ventricular hypertrophy. In comparison to reported surgical results, balloon angioplasty should be considered as first line treatment for native, discrete aortic coarctation in adolescent and adult patients.

Carboxy terminal variants of Epstein-Barr virus-encoded latent membrane protein 1 during long-term human immunodeficiency virus infection: reliable markers for individual strain identification

To assess the frequency and molecular polymorphism of malignancy-associated latent membrane protein 1 (LMP1) variants in human immunodeficiency virus type 1 (HIV-1) infection, 94 B-lymphoblastoid cell lines spontaneously derived from peripheral blood mononuclear cells (PBMC) and 30 PBMC samples at seroconversion and later (mean, 55 months) were analyzed by longitudinal comparative sequence analysis in 8 patients progressing to non-Hodgkin's lymphoma (AIDS-NHL), 7 patients to opportunistic infections, and 2 patients with long-term asymptomatic HIV-1 infection. The sequence polymorphism in the C-terminus of LMP1 was characteristic for strains harbored by individual patients, with high fidelity for strain identification. In 14 of the 17 patients, two different but characteristic LMP1 variants were identified. At HIV seroconversion in 8 of 15 patients, a 30-bp deletion (LMP1Delta) was present. Though serial analysis revealed a shift to LMP1Delta in some individuals, statistical analysis of the cohort does not support the hypothesis that accumulation of LMP1Delta variants in PBMC accounts for their observed high incidence in AIDS-NHL.

Short-term exposures of rats to airborne hydrogen fluoride

A series of acute inhalation exposures was performed with airborne hydrogen fluoride (HF) to establish the concentration response for nonlethal effects in the rat. Exposures were either 2 or 10 min long; concentrations ranged from 135 to 8621 ppm. Three additional exposures (20 to 48 ppm) were performed for 60 min. A mouth-breathing (MB) model with a tracheal cannula was used in most of the exposures to maximize delivery of the HF to the lower respiratory tract. Endpoints on the day after exposure included hematology, serum chemistry, bronchoalveolar lavage, pulmonary function, organ weights, and histopathology. Nasal resistance was measured in nose-breathing (NB) groups. Effects of exposure were generally limited to the respiratory tract and included alveolitis, bronchial lesions, altered parameters of pulmonary function and bronchoalveolar lavage, and mucosal necrosis, inflammation, and fibrinopurulent exudate in airways. Observed changes were concentration related and appeared more pronounced in major airways near the point of entry (trachea in MB animals and nose in NB animals). One group of MB animals exposed for 10 min to 1454 ppm was evaluated at 3 and 14 wk after exposure; the acute effects had resolved by those times. The effects of 2-min exposures were consistently more severe than those from 10-min exposures to the same product of concentration x time. Exposures of MB animals for 60 min to 20 or 48 ppm HF did not result in observable adverse effects, although quasistatic pressure-volume curves were shifted upward slightly after 48 ppm. These data provide an integrated picture of the concentration-related effects of short nonlethal exposures to HF.

Phase I trial of anti-CD3-stimulated CD4+ T cells, infusional interleukin-2, and cyclophosphamide in patients with advanced cancer

PURPOSE

We performed a phase I trial to determine whether in vivo expansion of activated CD4+ T cells was possible in cancer patients. 111Indium labeling was used to observe trafficking patterns of the infused stimulated CD4+ T cells. The influence of cyclophosphamide (CTX) dosing on immunologic outcome was also examined.

PATIENTS AND METHODS

Patients with advanced solid tumors or non-Hodgkin's lymphoma received CTX at 300 or 1,000 mg/m2 intravenously (i.v.). Leukapheresis was performed to harvest peripheral-blood mononuclear cells (PBMCs) either just before the CTX dose, or when the patient was either entering or recovering from the leukocyte nadir induced by CTX. An enriched population of CD4+ T cells was obtained by negative selection. The CD4+ T cells were activated ex vivo with anti-CD3, cultured with interleukin-2 (IL-2) for 4 days, and adoptively transferred. After adoptive transfer, patients received IL-2 (9.0 x 10(6) IU/m2/d) by continuous infusion for 7 days.

RESULTS

The absolute number of CD4+, CD4+/DR+, and CD4+/CD45RO+ T cells increased in a statistically significant fashion in all cohorts after the first course of therapy. The degree of CD4 expansion was much greater than CD8 expansion, which resulted in a CD4:CD8 ratio that increased in 26 of 31 patients. The greatest in vivo CD4 expansion occurred when cells were harvested as patients entered the CTX-induced nadir. One complete response (CR), two partial responses (PRs), and eight minor responses were observed. Trafficking of 111Indium-labeled CD4 cells to subcutaneous melanoma deposits was also documented.

CONCLUSION

CD4+ T cells can be expanded in vivo in cancer patients, which results in increased CD4:CD8 ratios. The timing of pheresis in relation to CTX administration influences the degree of CD4 expansion. Tumor responses with this regimen were observed in a variety of tumors, including melanoma and non-Hodgkin's lymphoma; a high percentage of patients had at least some tumor regression from the regimen that produced the greatest CD4+ T-cell expansion.

Acute effects of 10-minute exposure to hydrogen fluoride in rats and derivation of a short-term exposure limit for humans

A series of acute inhalation exposures of female rats was conducted with hydrogen fluoride (HF) to establish a concentration-response curve for nonlethal exposures. Durations of 2 and 10 min were used to simulate possible short-term exposures. Concentrations of HF ranged from 593 to 8621 ppm for 2-min exposures and from 135 to 1764 ppm for 10-min exposures. Additional exposures were performed for 60 min at 20 and 48 ppm HF for comparison to existing Emergency Response Planning Guidelines. Animals were evaluated on the day after exposure for changes in parameters of bronchoalveolar lavage, pulmonary function, hematology, serum chemistry, body weight, organ weights, and histopathology. Most exposures were performed with orally cannulated animals to bypass absorption of HF in the nose and achieve maximum delivery of HF to the lower airways. One of the primary uses of the resulting data was to estimate a concentration to which most people could be exposed for 10 min without severe of irreversible health effects. This level was 130 ppm. It was predicted that irritation would occur at this concentration, but the effects on t he respiratory tract would not be "serious" and would be expected to be reversible. The results of this experiment and the subsequent analysis of the data provide an important aid in he planning of responses to an accidental release of HF.

One- to ten-year follow-up results of balloon angioplasty of native coarctation of the aorta in adolescents and adults

OBJECTIVES

We attempted to evaluate the role of balloon angioplasty in the treatment of discrete coarctation of the aorta in adolescents and adults, with special emphasis on long-term results.

BACKGROUND

Controversy persists over the use of balloon dilation for the treatment of native coarctation of the aorta.

METHODS

Between July 1986 and January 1997, 43 consecutive adolescent and adult patients with discrete coarctation of the aorta underwent balloon angioplasty. One- to 10-year follow-up data of 37 patients, including results of cardiac catheterization and magnetic resonance imaging (MRI), form the basis of this study.

RESULTS

No early or late deaths occurred. Balloon angioplasty produced a reduction in the peak to peak coarctation gradient from a mean +/- SD of 69 +/- 24 mm Hg (95% confidence interval [CI] 61 to 76) to 12 +/- 8 mm Hg (95% CI 10 to 14.8) (p < 0.001). Follow-up catheterization 12 months later (37 patients) revealed a residual gradient of 6.7 +/- 6 mm Hg (95% CI 4.6 to 8.9); 3 (7%) of 43 patients had suboptimal results with development of recoarctation, defined as peak gradient >20 mm Hg, with successful repeat angioplasty. A small aneurysm developed at the site of dilation in 3 (7%) of the 43 patients. MRI follow-up data 1 to 10.8 years (mean 5.2 +/- 2.7) after angioplasty (37 patients) revealed no new aneurysm or appreciable change in the size of the preexisting aneurysm in the three patients. The blood pressure had normalized without medication in 27 (73%) of 37 patients at follow-up examination.

CONCLUSIONS

Balloon angioplasty is safe and effective and should be considered a viable alternative to operation for treatment of discrete coarctation of the aorta in adolescents and adults.

Angiomatoid malignant fibrous histiocytoma revisited. An immunohistochemical and DNA ploidy analysis

A histologic, immunohistochemical, and DNA ploidy analyses were performed on two cases of angiomatoid malignant fibrous histiocytoma to ascertain the histogenesis and relationship of endothelial, histiocytic, and fibroblastic elements. Both cases were slowly growing, grossly encapsulated. Subcutaneous masses resected from pediatric patients. Microscopically, the tumors were composed of solid masses of epithelioid and spindle cells with abnormal endothelial-lined and blood-filled cystic spaces surrounded by normal vascular structures and aggregates of lymphocytes occasionally forming germinal follicles. The tumor cells stained exclusively with CD34 and vimentin antibodies. Tumor-associated vessels stained for CD31, CD34, vimentin, and Ulex europaeus. Occasional cells within germinal follicles stained for lysozyme, CD68, and HAM56. Ploidy analysis of tumor cells showed intermediate aneuploidy with a DNA index of 1.14. Blood vessels within and surrounding the tumor as well as inflammatory cells were DNA euploid. These studies suggest that the tumor--though comprised of histologically and immunohistochemically benign-appearing euploid endothelial, fibroblastic, and inflammatory elements--contains an aneuploid population of undifferentiated mesenchymal cells.

Genetic and physical maps of Saccharomyces cerevisiae

Genetic and physical maps for the 16 chromosomes of Saccharomyces cerevisiae are presented. The genetic map is the result of 40 years of genetic analysis. The physical map was produced from the results of an international systematic sequencing effort. The data for the maps are accessible electronically from the Saccharomyces Genome Database (SGD: http://genome-www.stanford. edu/Saccharomyces/).

Segregation analysis of ovarian cancer using diathesis to include other cancers

Despite the recent cloning of BRCA1, BRCA2 and the mismatch repair genes, it will still be a long time before it is possible to specify any individual's risk for ovarian cancer based on her genotype. Most women concerned about their risk on the basis of one or two affected relatives do not belong to extensive ovarian cancer families. Risk calculations depend on a reliable genetic model for ovarian cancer derived, ideally, from the population from which an individual is drawn. We have carried out a segregation analysis using data collected from consecutive ovarian cancer patients in two different centres in the UK. Complex segregation analysis was carried out with the addition of diathesis as a separate parameter allowing other cancers, associated with ovarian cancer, to be taken into account. The use of diathesis in the derivation of this alternative model is described. Analysed under joint likelihood without diathesis, the gene frequency is 0.0028 and penetrance to age 70 years is 50%. This is in agreement with other published models. Incorporating diathesis into the model under joint likelihood gives similar parameters for a single locus model but gives the best fit with a two locus model where both genes are rare.