Development and psychometric evaluation of item banks for memory and attention - supplements to the EORTC CAT Core instrument

BACKGROUND

Cancer patients may experience a decrease in cognitive functioning before, during and after cancer treatment. So far, the Quality of Life Group of the European Organisation for Research and Treatment of Cancer (EORTC QLG) developed an item bank to assess self-reported memory and attention within a single, cognitive functioning scale (CF) using computerized adaptive testing (EORTC CAT Core CF item bank). However, the distinction between different cognitive functions might be important to assess the patients' functional status appropriately and to determine treatment impact. To allow for such assessment, the aim of this study was to develop and psychometrically evaluate separate item banks for memory and attention based on the EORTC CAT Core CF item bank.

METHODS

In a multistep process including an expert-based content analysis, we assigned 44 items from the EORTC CAT Core CF item bank to the memory or attention domain. Then, we conducted psychometric analyses based on a sample used within the development of the EORTC CAT Core CF item bank. The sample consisted of 1030 cancer patients from Denmark, France, Poland, and the United Kingdom. We evaluated measurement properties of the newly developed item banks using confirmatory factor analysis (CFA) and item response theory model calibration.

RESULTS

Item assignment resulted in 31 memory and 13 attention items. Conducted CFAs suggested good fit to a 1-factor model for each domain and no violations of monotonicity or indications of differential item functioning. Evaluation of CATs for both memory and attention confirmed well-functioning item banks with increased power/reduced sample size requirements (for CATs ≥ 4 items and up to 40% reduction in sample size requirements in comparison to non-CAT format).

CONCLUSION

Two well-functioning and psychometrically robust item banks for memory and attention were formed from the existing EORTC CAT Core CF item bank. These findings could support further research on self-reported cognitive functioning in cancer patients in clinical trials as well as for real-word-evidence. A more precise assessment of attention and memory deficits in cancer patients will strengthen the evidence on the effects of cancer treatment for different cancer entities, and therefore contribute to shared and informed clinical decision-making.

Patient-reported outcome measures for physical function in cancer patients: content comparison of the EORTC CAT Core, EORTC QLQ-C30, SF-36, FACT-G, and PROMIS measures using the International Classification of Functioning, Disability and Health

BACKGROUND

Patient-reported physical function (PF) is a key endpoint in cancer clinical trials. Using complex statistical methods, common metrics have been developed to compare scores from different patient-reported outcome (PRO) measures, but such methods do not account for possible differences in questionnaire content. Therefore, the aim of our study was a content comparison of frequently used PRO measures for PF in cancer patients.

METHODS

Relying on the framework of the International Classification of Functioning, Disability and Health (ICF) we categorized the item content of the physical domains of the following measures: EORTC CAT Core, EORTC QLQ-C30, SF-36, PROMIS Cancer Item Bank for Physical Function, PROMIS Short Form for Physical Function 20a, and the FACT-G. Item content was linked to ICF categories by two independent reviewers.

RESULTS

The 118 items investigated were assigned to 3 components ('d - Activities and Participation', 'b - Body Functions', and 'e - Environmental Factors') and 11 first-level ICF categories. All PF items of the EORTC measures but one were assigned to the first-level ICF categories 'd4 - Mobility' and 'd5 - Self-care', all within the component 'd - Activities and Participation'. The SF-36 additionally included item content related to 'd9 - Community, social and civic life' and the PROMIS Short Form for Physical Function 20a also included content related to 'd6 - domestic life'. The PROMIS Cancer Item Bank (v1.1) covered, in addition, two first-level categories within the component 'b - Body Functions'. The FACT-G Physical Well-being scale was found to be the most diverse scale with item content partly not covered by the ICF framework.

DISCUSSION

Our results provide information about conceptual differences between common PRO measures for the assessment of PF in cancer patients. Our results complement quantitative information on psychometric characteristics of these measures and provide a better understanding of the possibilities of establishing common metrics.

Inactivation of Cryptosporidium parvum oocysts and faecal indicator bacteria in cattle slurry by addition of ammonia

AIMS

To determine inactivation of Cryptosporidium parvum oocysts and reduction of Escherichia coli and enterococci in cattle slurry added aqueous ammonia.

METHODS AND RESULTS

Escherichia coli, enterococci and nonviable C. parvum oocysts (DAPI+PI+) were enumerated every second day for 2 weeks in cattle slurry amended with 60 mmol l^-1 aq. ammonia and compared with untreated slurry at three temperatures. Regardless of temperature, the proportion of nonviable C. parvum oocysts increased significantly faster over time in slurry with added ammonia than raw slurry (P = 0·021) corresponding to 62·0% higher inactivation (P = 0·001) at day 14. Additionally, 91·8% fewer E. coli and 27·3% fewer enterococci were observed in slurry added ammonia at day 14 compared to raw slurry.

CONCLUSION

The addition of aqueous ammonia to raw slurry significantly reduced the viability of C. parvum oocysts and numbers of bacterial indicators. Hence, ammonia is usable at lower pathogen concentrations in slurry before application to agricultural land.

SIGNIFICANCE AND IMPACT OF THE STUDY

Livestock waste is a valuable source of plant nutrients and organic matter, but may contain high concentrations of pathogens like E. coli and Cryptosporidium sp. that can be spread in the environment, and cause disease outbreaks. However, die-off rates of pathogens in organic waste can increase following increasing ammonia concentrations.

General population normative data for the EORTC QLQ-C30 health-related quality of life questionnaire based on 15,386 persons across 13 European countries, Canada and the Unites States

OBJECTIVE

The European Organisation for Research and Treatment of Cancer (EORTC) QLQ-C30 health-related quality of life questionnaire is one of the most widely used cancer-specific health-related quality of life questionnaires worldwide. General population norm data can facilitate the interpretation of QLQ-C30 data obtained from cancer patients. This study aimed at systematically collecting norm data from the general population to develop European QLQ-C30 norm scores and to generate comparable norm data for individual countries in Europe and North America.

METHODS

We collected QLQ-C30 data from the general population across 11 European Union (EU) countries, Russia, Turkey, Canada and United States (n ≥ 1000/country). Representative samples were stratified by sex and age groups (18-39, 40-49, 50-59, 60-69 and ≥ 70 years). After applying weights based on the United Nations population distribution statistics, we calculated QLQ-C30 domain scores to generate a 'European QLQ-C30 Norm' based on the EU countries. Further, we calculated QLQ-C30 norm scores for all 15 individual countries.

RESULTS

A total of 15,386 respondents completed the online survey. For the EU sample, most QLQ-C30 domains showed differences by sex/age, with men scoring somewhat better health than women, while age effects varied across domains. Substantially larger differences were seen in inter-country comparisons, with Austrian and Dutch respondents reporting consistently better health compared with British and Polish respondents.

CONCLUSIONS

This study is the first to systematically collect EORTC QLQ-C30 general population norm data across Europe and North America applying a consistent data collection method across 15 countries. These new norm data facilitate valid intra-country as well as inter-country comparisons and QLQ-C30 score interpretation.

The influence of feeding crimped kernel maize silage on broiler production, nutrient digestibility and meat quality

Two experiments were carried out in parallel with male Ross 308 broilers over 37 d. An experiment with a total of 736 broilers was performed to study the effect of dietary inclusion of crimped kernel maize silage (CKMS) on broiler production and meat quality. Another study with 32 broilers was carried out from 21 to 25 d to investigate the inclusion of CKMS on nutrient digestibility. In both trials, 4 dietary treatments were used: wheat-based feed (WBF), maize-based feed (MBF), maize-based feed supplemented with 15% CKMS (CKMS-15) and maize-based feed supplemented with 30% CKMS (CKMS-30). Compared with MBF, the dry matter (DM) intakes of broilers receiving CKMS-15 and CKMS-30, respectively, were numerically 7.5 and 6.2% higher and feed conversion ratio 6 and 12% poorer (significant for 30% CKMS), although there were no significant differences in AME content between the three diets. At 37 d, the body weight of birds receiving 15% CKMS was similar to birds fed with MBF. However, the inclusion of 30% CKMS decreased broiler growth. Dietary supplementation with CKMS significantly reduced the apparent digestibility of phosphorus. The fat digestibility was significantly lower for CKMS-30 than for the other three diets. Broiler mortality decreased significantly when CKMS was added to the diet. The consumption of drinking water was significantly lower in all maize-based diets as compared to WBF and was lowest in broilers fed with CKMS-30. An improved litter quality in terms of DM content and a lower frequency of foot pad lesions was observed with broilers supplemented with both dietary levels of CKMS. The addition of CKMS to maize-based diets increased juiciness, tenderness and crumbliness of the meat. In conclusion, the dietary supplementation of 15% CKMS had no negative effect on broiler growth and positively influenced bird welfare in terms of mortality and foot pad health. Therefore, the addition of 15% CKMS to maize-based diets is considered an advantageous feeding strategy in broiler production.

Long-term potential of in situ chemical reduction for treatment of polychlorinated biphenyls in soils

Polychlorinated biphenyls (PCBs) are well-known for being hydrophobic and persistent in the environment. Although many treatment approaches have been demonstrated to result in degradation of PCBs in water or water/cosolvent systems, few examples exist where such approaches have been applied successfully for PCB degradation in soil-water systems. A possible explanation for the limited treatment of PCBs in soil-water systems is that reactants that are capable of degrading PCBs in the aqueous phase are unlikely to persist long enough to achieve meaningful treatment of slowly-desorbing PCBs associated with the soil phase. To investigate this explanation, laboratory studies were conducted to evaluate chemical reductants, including zero valent metals, palladium (Pd) catalyst, and emulsified zero valent iron (EZVI), for dechlorination of PCBs in the presence and absence of soil. In the absence of soil, Pd-catalyzed treatments (Pd with electrolytic ZVI or iron/aluminum alloy) achieved rapid destruction of a model PCB congener, 2-chlorobiphenyl, with half-lives ranging from 43 to 110 min. For treatment of soils containing Aroclor 1248 at an initial concentration of approximately 1,500 mg kg(-1), Pd-catalyzed treatments achieved no measurable enhancement over the background PCB depletion rate (i.e., that measured in the untreated control) of 5.3 mg kg(-1)week(-1). In the presence of soils, EZVI was the only approach evaluated that resulted in a clear enhancement in PCB dechlorination rates. EZVI achieved PCB concentration reductions of greater than 50% at an average rate of 19 mg kg(-1)week(-1). The results suggest that slow PCB desorption limits treatment effectiveness in soils.

Investigation of spoilage in saveloy samples inoculated with four potential spoilage bacteria

Sliced saveloy samples were inoculated with monocultures of four potential spoilage bacteria and studied during a four week storage period. The objective was to investigate the resulting changes in the composition of Volatile Organic Compounds (VOCs) and the sensory quality of the product. Based on the sensory scores and the VOC composition Brochothrix thermosphacta, Chryseomonas luteola and Carnobacterium maltaromaticum were found to have a high spoilage potential in saveloy samples subjected to consumer simulated storage during the fourth week. Inoculation with Leuconostoc carnosum only resulted in a low level of spoilage. The sensory changes in the saveloy samples were modeled based on the VOC composition using Partial Least Squares Regression. The changes in the six sensory descriptors were closely related to the amount of diacetyl, acetoin, 2- and 3-methylbutanol, 2- and 3-methylbutanal and 2-methylpropanol found in the samples. These compounds are therefore potentially important for the shelf-life of sliced saveloy.

Arylethynyl derivatives of the dihydroazulene/vinylheptafulvene photo/thermoswitch: tuning the switching event

A selection of dihydroazulene (DHA) photoswitches incorporating an arylethynyl-substituent in the seven-membered ring was prepared by palladium-catalyzed Sonogashira cross-coupling reactions employing a suitable bromo-functionalized DHA. Shielding of the alkyne bridge and separating the aryl and DHA units, by sterically demanding groups, was required to obtain stable compounds. The DHAs underwent a light-induced ring-opening to vinylheptafulvenes (VHFs) which were thermally converted to a mixture of two DHA regioisomers, one of which was the original one. The influence of the aryl groups on the DHA and VHF absorptions and on their interconversion was investigated in detail. The rates of the switching events were finely tuned by the donor or acceptor strength of the aryl group. The thermal ring closure was found to proceed most readily in the presence of an electron-donating group on the seven-membered ring. The rate constant was found to follow a Hammett linear free energy correlation, which signals that stabilization of a positive charge in the seven-membered ring plays a crucial role in the ring-closure reaction. In view of these findings, it was possible to control the switching event by protonation/deprotonation of an anilino-substituted DHA. Also, the light-induced ring opening reaction was strongly controlled by acid/base. In addition to the mesomeric effects exerted by an arylethynyl group, the inductive effects exerted by different groups on the thermal ring closure were elucidated. Although the alkyne bridge transmits the electronic character of the aryl group, the ring-closure is retarded for all the ethynylated compounds relative to the parent unsubstituted compound. Along with our synthesis of suitable arylalkynes, we discovered an interesting byproduct in a Sonogashira cross-coupling reaction involving a nitrophenyl group, namely a diaryl azoxy compound. Its structure was confirmed by X-ray crystallographic analysis.

Symptoms and problems in a nationally representative sample of advanced cancer patients

Little is known about the need for palliative care among advanced cancer patients who are not in specialist palliative care. The purpose was to identify prevalence and predictors of symptoms and problems in a nationally representative sample of Danish advanced cancer patients. Patients with cancer stage 3 or 4 from 54 hospital departments (n = 1630) received the EORTC QLQ-C30 questionnaire. Mean scores were calculated according to the scoring manual and in addition a 'symptom/problem' and a 'severe symptom/problem' was defined and calculated. Multiple logistic regression was used to identify predictors. In total, 977 (60%) patients participated. The most frequent symptoms/problems were fatigue (57%; severe 22%) followed by reduced role function, insomnia and pain. Age, cancer stage, primary tumour, type of department, marital status and whether the patient had recently been hospitalized or not were associated with several symptoms and problems. This is probably the first nationally representative study of its kind. It shows that advanced cancer patients in Denmark have symptoms and problems that deserve attention and that some patient groups are especially at risk.

The use of differential item functioning analyses to identify cultural differences in responses to the EORTC QLQ-C30

INTRODUCTION

The European Organisation for Research and Treatment of Cancer (EORTC) QLQ-C30 is a widely used health-related quality of life instrument. The main aim of this study is to investigate whether there are international differences in response to the questionnaire that can be explained by cultural factors.

METHODS

Analyses involved a database of 106 separate studies including data from over 28,000 respondents. Differential item functioning (DIF) analyses using logistic regression were conducted for each item of the EORTC QLQ-C30 with respect to cultural/geographic group. Results were qualitatively compared with previously reported DIF analyses by translation to explore whether the source of the DIF was more likely to be linguistic or cultural in nature.

RESULTS

Although most response patterns were similar, there were a number of international differences in how the questionnaire was answered. The largest variations were found in the results for Eastern Europe and East Asia. Results for the UK, the US and Australia tended to be similar. Many of the European results followed patterns that were more clearly explained when grouped by translation than when grouped by geographical region.

DISCUSSION

Our results suggest that, in general, the EORTC QLQ-C30 is suitable for use in a wide variety of countries and settings. Some response variations that have the potential to affect the results of international studies were identified, but it was not always clear whether the source of the variation was primarily linguistic or cultural.

Absorption Studies of Neutral Retinal Schiff Base Chromophores

The neutral retinal Schiff base is connected to opsin in UV sensing pigments and in the blue-shifted meta-II signaling state of the rhodopsin photocycle. We have designed and synthesized two model systems for this neutral chromophore and have measured their gas-phase absorption spectra in the electrostatic storage ring ELISA with a photofragmentation technique. By comparison to the absorption spectrum of the protonated retinal Schiff base in vacuo, we found that the blue shift caused by deprotonation of the Schiff base is more than 200 nm. The absorption properties of the UV absorbing proteins are thus largely determined by the intrinsic properties of the chromophore. The effect of approaching a positive charge to the Schiff base was also studied, as well as the susceptibility of the protonated and unprotonated chromophores to experience spectral shifts in different solvents.

Comparing translations of the EORTC QLQ-C30 using differential item functioning analyses

The European Organisation for Research and Treatment of Cancer (EORTC) QLQ-C30 is one of the most widely used quality of life instruments for cancer patients. The aim of this study was to assess whether there were linguistic differences in the way an international sample answered the EORTC QLQ-C30 questionnaire. Thirteen translations of the EORTC QLQ-C30, representing 22 countries, were investigated using a database of 27,891 respondents, incorporating 103 separate studies. Differential item functioning (DIF) analyses were conducted using logistic regression to identify items which, after controlling for subscale, were answered differently by language of administration. Both uniform and non-uniform DIF were assessed. Although most languages showed similar results to English, at least one instance of statistically significant DIF was identified for each translation, and a few of these differences were large. In some cases, the patterns were supported by the results of qualitative interviews with bilingual people. Although, overall, there appeared to be good linguistic equivalence for most of the EORTC QLQ-C30 items, several scales showed strongly discrepant results for some translations. Some of these effects are large enough to impact on the results of clinical trials. Based on our experience in this study, we suggest that validation of translations of health-related quality of life instruments should include exploration of DIF.

Ridge-Bridge Adsorption of Molecular Oxygen on Pt{110}(1 × 2) from First Principles

The chemisorption of molecular oxygen on the missing-row reconstructed Pt[110](1 x 2) surface has been investigated using ab initio calculations based on spin-density functional theory. The calculated energetic, structural, vibrational, and electronic properties of the chemisorbed O2 species are discussed in terms of the available experimental data. We find that adsorption in the ridge-bridge site is strongly preferred on energetic grounds, relative to adsorption on the [111] microfacets or in the valley sites of the reconstructed surface. We argue in favor of initial adsorption in the ridge-bridge sites, followed by adsorption in the valley long-bridge sites at higher coverages, without excluding the possibility of bridge-site adsorption on the [111] microfacets.

Novel retinylidene iminium salts for defining opsin shifts: synthesis and intrinsic chromophoric properties

Retinal Schiff bases serve as chromophores in many photoactive proteins that carry out functions such as signalling and light-induced ion translocation. The retinal Schiff base can be found as neutral or protonated, as all-trans, 11-cis or 13-cis isomers and can adopt different conformations in the protein binding pocket. Here we present the synthesis and characterisation of isomeric retinylidene iminium salts as mimics blocked towards isomerisation at the C11 position and conformationally restrained. The intrinsic chromophoric properties are elucidated by gas phase absorption studies. These studies reveal a small blue-shift in the S0-->S1 absorption for the 11-locked derivative as compared to the unlocked one. The gas phase absorption spectra of all the cationic mimics so far investigated show almost no absorption in the blue region. This observation stresses the importance of protein interactions for colour tuning, which allows the human eye to perceive blue light.

Absorption of Schiff-Base Retinal Chromophores in Vacuo

The absorption spectrum of the all-trans retinal chromophore in the protonated Schiff-base form, that is, the biologically relevant form, has been measured in vacuo, and a maximum is found at 610 nm. The absorption of retinal proteins has hitherto been compared to that of protonated retinal in methanol, where the absorption maximum is at 440 nm. In contrast, the new gas-phase absorption data constitute a well-defined reference for spectral tuning in rhodopsins in an environment devoid of charges and dipoles. They replace the misleading comparison with absorption properties in solvents and lay the basis for reconsidering the molecular mechanisms of color tuning in the large family of retinal proteins. Indeed, our measurement directly shows that protein environments in rhodopsins are blue- rather than red shifting the absorption. The absorption of a retinal model chromophore with a neutral Schiff base is also studied. The data explain the significant blue shift that occurs when metharhodopsin I becomes deprotonated as well as the purple-to-blue transition of bacteriorhodopsin upon acidification.

Cyclization reactions of 1-[3′-hydroxy-2′-(hydroxymethyl)prop-1′-enyl]pyrimidine nucleobases: intramolecular Michael additions to the C(5)C(6) bonds and intramolecular dehydrations

The tendency of a series of acyclic nucleoside analogues 1a-f to undergo intramolecular cyclization reactions was investigated. All compounds, when treated with NaOD, were in equilibrium with the bicyclic compounds 2a-f, arising from Michael addition of a hydroxy group to the C(5)=C(6) bonds. Derivatives of 2,4-pyrimidinediones (1a,b) had the highest tendency to undergo intramolecular Michael addition when treated with triethylamine, whereas the cyclization of 4-amino-2-pyridones (1c-f) proceeded best with acid. The exocyclic double bond of was essential for the cyclization to occur. Commonly used N-protecting groups as the benzoyl- and the dibutylaminomethylene group enhanced cyclization. Under acidic anhydrous conditions 1b and 1e cyclized to the 2,4'-anhydro compounds 1b and 1e.

Serological Studies Using Polyclonal Antisera Prepared Against the Viral Coat Protein of Four Begomoviruses Expressed in Escherichia coli

Polyclonal rabbit antisera were produced to the coat protein of Bean golden mosaic virus Brazil isolate (BGMV), Cabbage leaf curl virus (CabLCV), Tomato yellow leaf curl virus (TYLCV), and Tomato mottle virus (ToMoV), all expressed in Escherichia coli by the pETh expression vector. The expressed coat protein of each virus was purified by sodium dodecyl sulfate-polyacrylamide gel electrophoresis for use as an immunogen. The antisera to BGMV, CabLCV, TYLCV, and ToMoV reacted in indirect (plate-trapping) enzyme-linked immunosorbent assay (ELISA) with extracts from begomovirus-infected tissue. The antisera to BGMV, CabLCV, TYLCV, and ToMoV also reacted specifically with the test begomovirus antigens in leaf imprint blots and Western blots. The CabLCV and TYLCV antisera were used to detect Bean golden yellow mosaic virus antigens by immunogold labeling of thin sections of infected bean tissues. In tissue blot immunoassays, the TYLCV antiserum reacted well with TYLCV antigens but not with ToMoV antigens, while CabLCV antiserum reacted well with ToMoV antigens and weakly with TYLCV antigens. The results indicate that polyclonal antisera prepared to expressed begomovirus coat proteins were useful for the detection of begomoviruses in an array of assays.

First Report of a Furovirus Infecting Field-Grown Rye in North America

Viral symptoms were present in a dwarf recurrent population (99RP17) of rye (Secale cereale) at the North Florida Research and Education Center in Quincy, Gadsden County, FL, during the winter and spring of 2000. Symptoms and distribution of the infected plants in the field were similar to those caused by Soilborne wheat mosaic virus (SBWMV; acronym WSBMV), which was first recognized in North America in 1919 (4) and found in Florida in wheat in 1970 (3). SBWMV has been observed based on symptoms in rye in North America (4). Interveinal, non-continuous, chlorotic areas of leaves and stunting of plants in patchy patterns occurred in four locations (0.8 to 1.6 km between locations). Incidences of the disease ranged from 3 to 15%. Leaves and roots of more than 25 plants were assessed. Using light microscopy, after staining with Calcomine Orange 2RS/Luxol Brilliant Green BL (1), amorphous, vacuolate inclusions were observed in all assayed leaves. With electron microscopy, rigid rods were present with a bimodal distribution of particle lengths that conformed to size distributions found originally in wheat in 1970 in Florida. Leaves with symptoms were sent to Agdia Inc. (Elkhart, IN) and samples were strongly positive for SBWMV using enzyme-linked immunosorbent assay. Cystosori of Polymyxa graminis were detected from a few roots from symptomatic plants. While these associations are suggestive of SBWMV, and rye is a reported host of SBWMV, the possibility of this virus being soilborne rye mosaic virus exists (2). Such a differentiation will require nucleotide sequence analysis. To our knowledge, this is the first report of a furovirus infecting field-grown rye in Florida and in North America. References: (1) R. G. Christie and J. R. Edwardson. 1994. Light and Electron Microscopy of Plant Virus Inclusions Monogr. 9. University of Florida, Quincy. (2) R. Koenig et al. 1999. Arch. Virol. 144:2125-2140. (3) T. A. Kucharek and J. H. Walker. Plant Dis. Rep. 58:763-765, 1974. (4) H. H. McKinney. J. Agric. Res. 23:771-800, 1923.

Development of a protocol to prevent opioid-induced constipation in patients with cancer: a research utilization project

Opioids are the major class of analgesics used in the management of moderate to severe cancer pain, and constipation is a common side effect of opioid administration. While monitoring for quality-assurance, nurses found that 95% of patients interviewed on a 28-bed oncology unit of a Midwestern hospital reported constipation as the major side effect of their opioid regimen for pain control. Through the efforts of a nursing research utilization committee, a protocol to prevent opioid-induced constipation in patients with cancer was developed and implemented.

Influence of variety and growing location on the development of off-flavor in precooked vacuum-packed potatoes

Development of potato off-flavor (POF) was examined in precooked vacuum-packed potatoes by GC and sensory analyses. The experiments comprised four varieties grown at two locations. Aroma compounds shown to be potential contributors to POF were determined quantitatively, and their relative importance was interpreted by aroma values based on odor detection threshold values determined in water. There were statistically significant differences in the content of POF compounds between the growing locations and among some of the varieties. The results from the sensory analyses concurred roughly with the GC analyses. (E,E)-2,4-Nonadienal and (E, E)-2,4-decadienal were shown to be the most potent of the POF compounds examined, in addition with hexanal, (E)-2-octenal, and (E)-2-nonenal. Lowering the development of POF in precooked vacuum-packed potatoes should be possible by optimizing the environmental conditions and breeding for suitable varieties.

Partial Characterization of a Distinct Potyvirus Isolated from Watermelon in Florida

Conspicuous, unusual nuclear inclusions in stained epidermal strips of leaves implicated a virus (designated isolate 2932) as the cause of foliar mosaic in a watermelon plant (Citrullus lanatus) received for analysis from South Florida in 1990. In greenhouse tests, mechanically inoculated plants of Cucurbita pepo (Small Sugar pumpkin and Early Prolific Straightneck squash) and watermelon (Crimson Sweet) developed mosaic or mottle symptoms. Isolate 2932 caused foliar symptoms in 16 cultivars of Cucurbita pepo, including Freedom II and Prelude II, and in six cultivars of watermelon. None of five cultivars of melon (Cucumis melo) or 11 cultivars of cucumber (Cucumis sativus) developed consistent, distinctive symptoms, but all of these cultivars were systemically infected based on back-inoculations to squash. No systemic infection of mechanically inoculated plants of 25 species representing 13 noncucurbitaceous plant families was detected. Crystalline nuclear inclusions, cytoplasmic amorphous inclusions, and cytoplasmic cylindrical inclusions were detected by light and electron microscopy in leaf tissues of infected squash and watermelon. Electron microscopy of squash leaf extracts revealed filamentous particles, and 86% of 159 particles measured ranged from 800 to 890 nm in length. The virus was transmitted in a nonpersistent manner by Myzus persicae from squash to squash in two of three trials. Immunodiffusion tests with polyclonal antisera prepared to partially purified 2932 or its capsid protein showed that the isolate was antigenically different from papaya ringspot virus type W, watermelon mosaic virus 2, and zucchini yellow mosaic virus. In limited testing of field samples of squash and watermelon since 1990, no additional isolates of the 2932 type have been found. The characteristics of isolate 2932 obtained thus far indicate that it is a distinct potyvirus. It is tentatively named watermelon leaf mottle virus to distinguish it from other potyviruses commonly isolated from cucurbits in Florida.

Ascorbic acid and dehydroascorbic acid content of blanched sweet green pepper during chilled storage in modified atmospheres

Sweet green pepper (Capsicum annuum L.) cut into pieces was analysed for ascorbic acid (AA) and dehydroascorbic acid (DHAA) content before and after blanching, after 1, 4 and 7 days of chilled storage in modified atmosphere, and after reheating. No difference in retention of AA was noted between storage in 2 and 4% O2 atmospheres, whereas retention during storage in air was significantly lower. Production of DHAA during storage increased with increased O2 content in the atmosphere. After 7 days of storage, DHAA contributed 10-35% of the total AA, and DHAA contributed 12-25% after reheating, depending on the O2 content in the atmosphere. Since the vitamin activity of DHAA is considered to be the same as that of AA, it is concluded that the content of DHAA in processed green pepper is of importance and should be measured together with AA.

Influence of sous vide processing, steaming and boiling on vitamin retention and sensory quality in broccoli florets

In this study the effect of sous vide processing, steaming and traditional boiling of broccoli florets on retention of ascorbic acid, vitamin B6 and folacin was investigated. Freshly prepared samples were also sensorily evaluated. In all heat treatments ascorbic acid was found to have the highest retention, and was therefore judged not to be suitable as an indicator for vitamin retention in general. When the three types of heat treatment were compared, boiling showed lowest retention of all the vitamins examined (45-64% in 5 min), whereas sous-vide processing gave the highest retentions (97-100% in 5 min). Retentions during steaming were a little lower (83-100% in 5 min). Sensory evaluation showed that sous-vide cooked and steamed broccoli florets generally had higher acceptability than boiled.

A new simplified dietary history method for measuring intake of energy and macronutrients

In this dietary history method, which preserves the characteristic features of the full dietary history, the principle of simplification is to group several food items into common codes. This enables us to complete both an interview and all nutrient calculations within 35-45 min. In this study we investigated whether the method could replace a 4-day food record for assessing individual intakes of energy and macronutrients. Dietary data were collected from 75 individuals (57 males and 18 females). Protein intake was validated by comparison with 24 h urinary nitrogen excretion (33 subjects), and energy intake was compared to weight maintenance energy intake from a later controlled diet study (19 subjects). When average intakes according to the two methods were compared, dietary history intakes were slightly higher than food record results (0-13%) except for alcohol. Comparison with urinary nitrogen excretion and energy intake data indicate that this is due to an overestimation by the dietary history method, rather than an underestimation by the food record. For individuals most of the correlations between the two methods were in the range 0.5-0.7, but alcohol correlation was down to 0.2. About 75% (53-93%) of the individuals at the extremes of the intake distribution were classified similarly by both methods. Although the ability of the dietary history to predict the individual food record results was unreliable the two methods agreed better when classifying individuals relative to certain cut-off points (sensitivity and specificity values of 0.7-0.9, relative to the food records).(ABSTRACT TRUNCATED AT 250 WORDS)