Special-Fed Veal: Separable components, proximate composition, and nutrient analysis of selected raw and cooked, wholesale and retail cuts.

Nutrition research continues to be important for consumers to make informed food purchasing decisions and is used in nutrition policy decisions. The objective of this study was to analyze the nutrient concentration of raw and cooked cuts from special-fed veal calves to update nutrient data in the USDA National Nutrient Database for Standard Reference (SR) Release 27. Packages of wholesale (whole loin roasts, center-cut hindshanks and ground veal) and retail veal cuts (osso buco foreshanks, loin chops, leg cutlets and shoulder blade chops) were randomly collected in original vacuum packaging from six U.S. suppliers. Packages were shipped to the Colorado State University Meat Laboratory for cut dissection, cooking, and nutrient analysis. Composites of lean, external fat and seam fat were formed for analysis of proximate, fatty acid, vitamin and mineral composition. Results from this study identified additional fatty acids, established choline concentration, and provided updated veal nutrient composition information for inclusion in USDA SR 27.

A pilot randomized controlled trial of time-intensive cognitive-behaviour therapy for postpartum obsessive-compulsive disorder: effects on maternal symptoms, mother-infant interactions and attachment.

BACKGROUND: There is increasing recognition that perinatal anxiety disorders are both common and potentially serious for mother and child. Obsessive-compulsive disorder (OCD) can be triggered or exacerbated in the postpartum period, with mothers reporting significant effects on parenting tasks. However, there is little evidence concerning their effective treatment or the impact of successful treatment on parenting. METHOD: A total of 34 mothers with OCD and a baby of 6 months old were randomized into either time-intensive cognitive-behaviour therapy (iCBT) or treatment as usual (TAU). iCBT took place after randomization at 6 months postpartum and was completed by 9 months. Maternal symptomatology, sensitivity in mother-infant interactions and parenting were assessed at baseline and reassessed at 12 months postpartum. At 12 months attachment was also assessed using Ainsworth's Strange Situation Procedure. A healthy control group of mothers and infants (n = 37) underwent the same assessments as a benchmark. RESULTS: iCBT was successful in ameliorating maternal symptoms of OCD (controlled effect size = 1.31-1.90). However, mother-infant interactions were unchanged by treatment and remained less sensitive in both OCD groups than a healthy control group. The distribution of attachment categories was similar across both clinical groups and healthy controls with approximately 72% classified as secure in each group. CONCLUSIONS: iCBT is an effective intervention for postpartum OCD. Sensitive parenting interactions are affected by the presence of postpartum OCD and this is not improved by successful treatment of OCD symptoms. However, the overall attachment bond appears to be unaffected. Longitudinal studies are needed to explore the impact of postpartum OCD as the child develops.

Effects of ractopamine hydrochloride on the growth performance and carcass characteristics of heavy-weight finishing pigs sent for slaughter using a 3-phase marketing strategy.

A total of 2,158 crossbred pigs was used to evaluate the effects of feeding 7.4 mg/kg ractopamine hydrochloride (RAC) on the growth performance and carcass characteristics of heavy-weight finishing pigs sent to slaughter using a 3-phase marketing strategy. The study was performed from 121.0 ± 4.28 kg to 144.5 ± 4.73 BW using a randomized complete block design (blocking factor was d of start on test) with 2 treatments (0 vs. 7.4 mg/kg RAC). Pigs were housed in a commercial wean-to-finish facility in groups of approximately 25 (44 groups/treatment), with ad libitum access to feed and water throughout the study, and pen weights of pigs were recorded at the start (d 0), and on d 7, 21, and 35 of study. Pigs were sent for slaughter according to the following marketing strategy: 1) after 7 d on RAC, the heaviest 16% of each pen was sent for slaughter (Phase 1), 2) after 21 d on RAC, the next 40% of each pen was sent for slaughter (Phase 2), and 3) after 35 d on RAC, the remaining 44% of each pen was sent for slaughter (Phase 3). Pigs were selected for slaughter by visual appraisal and shipped to a commercial facility where standard carcass measurements (HCW, LM depth, and backfat depth) were measured. Overall, feeding RAC increased (P < 0.001) ADG (18.8%) and G:F (23.7%) compared to the control, but lowered (P < 0.001) ADFI (3.3%). In addition, feeding RAC increased (P < 0.001) HCW (3.9 kg), carcass yield (0.7% units), LM depth (5.0%), and predicted lean content (1.0% units), and reduced backfat depth (6.3% lower) compared to controls. With each subsequent phase of marketing, the magnitude of improvements in response to feeding RAC decreased for ADG (43.1, 20.9, and -3.1% for Phase 1, 2, and 3, respectively) and G:F (37.5, 25.8, and 6.4% for Phase 1, 2, and 3, respectively); however, improvements in HCW (1.6, 4.5, and 4.2 kg for Phase 1, 2, and 3, respectively), carcass yield (0.2, 0.6, and 0.9% units for Phase 1, 2, and 3, respectively), LM depth (2.3, 5.7, and 5.2% for Phase 1, 2, and 3, respectively), and predicted lean content (0.2, 1.0, and 1.3% units for Phase 1, 2, and 3, respectively) generally increased from feeding RAC. These results suggest that while improvements in growth performance from feeding RAC will generally decline after 21 d of feeding, improvements in carcass traits, particularly carcass yield and lean content, will continue with feeding RAC until d 35.

Nutrient database improvement project: Separable components and proximate composition of raw and cooked retail cuts from the beef loin and round.

Beef nutrition research has become increasingly important domestically and internationally for the beef industry and its consumers. The objective of this study was to analyze the nutrient composition of ten beef loin and round cuts to update the nutrient data in the USDA National Nutrient Database for Standard Reference. Seventy-two carcasses representing a national composite of Yield Grade, Quality Grade, sex classification, and genetic type were identified from six regions across the U.S. Beef short loins, strip loins, tenderloins, inside rounds, and eye of rounds (NAMP # 173, 175, 190A, 169A, and 171C) were collected from the selected carcasses and shipped to three university meat laboratories for storage, retail fabrication, and raw/cooked analysis of nutrients. Sample homogenates from each animal were analyzed for proximate composition. These data provide updated information regarding the nutrient status of beef, in addition, to determining the influence of Quality Grade, Yield Grade, and sex classification on nutrient composition.

Effects of USDA carcass maturity on sensory attributes of beef produced by grain-finished steers and heifers classified as less than 30 months old using dentition.

This study compared sensory properties of LM steaks from A maturity and B maturity or older carcasses that were produced by grain-finished steers and heifers classified as less than 30 mo old at the time of slaughter using dentition. Carcasses were selected to represent 2 maturity groups and 3 marbling categories within each maturity group, resulting in 6 maturity × marbling subclasses, each subclass consisting of 75 carcasses. Maturity groups consisted of carcasses classified by USDA graders as either A(00) to A(99) overall (A) maturity or B(00) to C(99) overall (B-C) maturity; marbling categories consisted of carcasses with instrument marbling scores of Slight (SL), Small (SM), or Modest(00) or greater (MT+). Carcasses were selected in pairs so that each carcass chosen to represent the B-C maturity group was paired with an A maturity carcass of the same sex and marbling score (± 30 marbling units). Strip loin (LM) steaks were obtained from both sides of each carcass. After a 14-d aging period, 1 LM steak was measured for Warner-Bratzler shear force (WBSF) and slice shear force (SSF), whereas the other LM steak was used for sensory analysis by a trained descriptive attribute panel. No differences (P > 0.05) in WBSF, SSF, or sensory panel ratings for tenderness, juiciness, or flavor were detected between LM steaks from carcasses classified as A maturity and steaks from B-C maturity carcasses. However, marbling categories effectively stratified carcasses (MT+ > SM > SL) according to differences (P < 0.0001) in LM tenderness, juiciness, meaty/brothy flavor, and buttery/beef fat flavor. Increased marbling also was associated with lesser (P < 0.01) intensities of bloody/serumy and livery/organy flavors and reduced (P < 0.01) values for WBSF and SSF. Of the traits tested, only bloody/serumy flavor was affected (P < 0.05) by the maturity × marbling interaction. Interaction means showed that LM steaks from B-C maturity carcasses with SL marbling had a less intense bloody/serumy flavor than did steaks from A maturity carcasses with SL marbling. Results of this study suggest that, when applied to carcasses from grain-finished cattle whose dental ages are less than 30 mo old at the time of slaughter, USDA quality grades would be no less effective in identifying eating quality differences if the A and B-C maturity groups were combined and quality grades were assigned using only marbling.

Effects of ractopamine hydrochloride and zilpaterol hydrochloride supplementation on longissimus muscle shear force and sensory attributes of calf-fed Holstein steers.

The effect of ractopamine hydrochloride (RH) and zilpaterol hydrochloride (ZH) on slice shear force (SSF) and sensory characteristics of beef from calf-fed Holstein steers was evaluated. All steers were implanted with a progesterone (100 mg) plus estradiol benzoate (10 mg) implant followed by a terminal trenbolone acetate (200 mg) plus estradiol (40 mg) implant. Steers were blocked by weight into pens (n = 32) randomly assigned to 1 of 4 treatments: control, RH fed at 300 mg·steer(-1)·d(-1) (RH 300) or RH fed at 400 mg·steer(-1)·d(-1)(RH 400) for the final 31 d of finishing, or ZH fed at 6.8 g/t for 21 d with a 5-d withdrawal before harvest. Fourteen carcasses were randomly selected from each pen, and two LM samples (1 per side) were excised and aged either 14 or 21 d before SSF testing. For trained panel evaluation, two steaks were collected from each of 60 low Choice strip loins (20 each from control, RH 300, and ZH treatments) and aged either 14 or 21 d. Steers fed RH and ZH produced steaks with SSF values that were 9% to 25% higher than controls. No difference in SSF was detected between the two levels of RH (P > 0.05). Compared to controls, the probability of steaks aged 14 d failing to meet SSF requirements to be certified tender (SSF < 20 kg) was increased 0.15, 0.17, and 0.26 in steers fed RH 300, RH 400, and ZH, respectively. Compared to controls, the probability of steaks aged 21 d having SSF values >20 kg was increased 0.03, 0.08, and 0.16 in steers fed RH 300, RH 400, and ZH, respectively. Steaks from Select carcasses of steers fed ZH aged 21 d postmortem had double the probability (0.39 vs. 0.17) of having SSF values >20 kg compared to steaks from steers fed either level of RH (P < 0.05). This difference tended to be identical in steaks from Select carcasses 14 d postmortem (0.50 vs. 0.33; P = 0.11); however, no difference was found in low Choice samples at 14 or 21 d postmortem. Trained panelists rated steaks aged 14 d from steers fed ZH lower for overall tenderness and flavor compared to controls (P < 0.05); however, no difference was found between controls and those fed RH 300. Steaks from steers fed ZH aged 21 d were rated lower for overall tenderness and juiciness compared to controls and those from steers fed RH 300 (P < 0.05). This study suggests RH and ZH negatively impact sensory attributes of beef from calf-fed Holstein steers.

Effects of ractopamine hydrochloride and zilpaterol hydrochloride supplementation on carcass cutability of calf-fed Holstein steers.

Effects of ractopamine hydrochloride (RH) and zilpaterol hydrochloride (ZH) on saleable yield of carcass sides from calf-fed Holstein steers were evaluated using steers implanted with a progesterone (100 mg) plus estradiol benzoate (10 mg) implant followed by a terminal trenbolone acetate (200 mg) plus estradiol (40 mg) implant. Steers were blocked by weight into pens (n = 32) randomly assigned to one of four treatments: control, RH fed at 300 mg•steer(-1)/d(-1) (RH 300) or RH fed at 400 mg•steer(-1)/d(-1) (RH 400) the final 31 d of finishing, and ZH fed at 60 to 90 mg•steer(-1)/d(-1) (7.56 g/ton on a 100% DM basis) for 21 d with a 5 d withdrawal before harvest. Eight to nine carcass sides were randomly selected from each pen; carcass sides with excessive hide pulls, fat pulls or bruises were avoided. Cutout data were collected within a commercial facility using plant personnel to fabricate sides at a rate of one every 3 to 4 min into items typically merchandised by the facility. All lean, fat and bone were weighed and summed back to total chilled side weight with a sensitivity of ± 2% to be included in the data set. Compared to controls, ß-agonists increased saleable yield of whole-muscle cuts by 0.61%, 0.86% and 1.95% for RH 300, RH 400 and ZH, respectively (P < 0.05). Percent fat was less in carcasses from the ZH treatment compared to controls (P < 0.05); however, this difference was not observed between RH treatments and controls (P > 0.05). Percent bone was less in the ZH treatment due to increased muscle (P < 0.05). The percent of chilled side weight comprised of trimmings was unchanged between treatments, but on a 100% lean basis, RH 400 and ZH increased trim yields (P < 0.05). Analysis of saleable yield by primal showed a fundamental shift in growth and development. Beta-agonists caused a shift in proportion of saleable yield within individual primals, with a greater portion produced from the hindquarter relative to the forequarter, specifically in those muscles of the round (P < 0.05). Beta-agonists increased saleable yield, but these effects were not constant between all major primals. The cutout value gained by packers as a result of ß-agonist use may be influenced more by reduced fatness and increased absolute weight if musculature is primarily increased in the lower priced cuts of the carcass.

Nutrient analysis of the Beef Alternative Merchandising cuts.

The objective of this study was to generate raw and cooked nutrient composition data to identify Quality Grade differences in proximate values for eight Beef Alternative Merchandising (BAM) cuts. The data generated will be used to update the nutrient data in the USDA National Nutrient Database for Standard Reference (SR). Beef Rib, Oven-Prepared, Beef Loin, Strip Loin, and Beef Loin, Top Sirloin Butt subprimals were collected from a total of 24 carcasses from four packing plants. The carcasses were a combination of USDA Yield Grades 2 (n=12) and 3 (n=12), USDA Quality Grades upper two-thirds Choice (n=8), low Choice (n=8), and Select (n=8), and two genders, steer (n=16) and heifer (n=8). After aging, subprimals were fabricated into the BAM cuts, dissected, and nutrient analysis was performed. Sample homogenates from each animal were homogenized and composited for analysis of the following: proximate analysis, long chain and trans-fatty acids, conjugated linoleic acid, total cholesterol, vitamin B-12, and selenium. This study identified seven BAM cuts from all three Quality Grades that qualify for USDA Lean; seven Select cuts that qualify for USDA Extra Lean; and three Select cuts that qualify for the American Heart Association's Heart Healthy Check.

Targeted mydriasis strategies for diabetic retinopathy screening clinics.

PURPOSE: To examine factors necessitating pupil dilation to achieve gradable diabetic screening photographs using a digital non-mydriatic camera and to establish techniques to predict the need for dilation and to validate them. METHODS: Prospective clinic-based cross-sectional study with follow-up validation study. The participants' involved consecutive patients attending the diabetic retinopathy screening clinic at a University Hospital. Best corrected visual acuity, age, sex, pupil size, mean spherical equivalent, cataract grade and the requirement for dilation to achieve gradable photographs in 90 patients were recorded. Data analysis using principal component analysis and multivariate analysis of variance derived a set of equations to predict the requirement for dilation. The predictive powers of these equations were validated in an independent group of 51 patients. RESULTS: Smaller pupil size, denser nuclear colour, older age, poorer best-corrected visual acuity, cortical lens opacity and posterior subcapsular lens opacity were associated with the need for dilation (P<0.001 in all). Single variables used in isolation had a poorer predictive value than combining variables. Dilating patients with either a pupil size>3.75 mm or age>59 years correctly allocates 83 and 78% of patients, respectively to dilation or not. Combining pupil size with age produces a decision table that improves the predictive value to 84%. In the validation study this table had a predictive value of 80%. CONCLUSION: We have produced and validated criteria based on a range of clinical variables for application in a clinical setting that allows for the development of targeted mydriasis.

Right-sided spatial difficulties in ADHD demonstrated in continuous movement control.

Children with Attention Deficit Hyperactivity Disorder (ADHD) often show spatial attentional deficits, exhibiting a subtle rightwards bias, possibly due to dysfunction within the right hemisphere fronto-parietal network. Approximately 50% of children with ADHD also show signs of movement dysfunction. The nature of this movement dysfunction and possible interactions with spatial attention difficulties has not been clearly described. This study compared 31 children with and 31 children without ADHD on a movement kinematic task that tested hand-drawing movement precision. Participants used an electronic pen on a digitizing tablet. The pen tip position was sampled as X and Y coordinates at 200Hz. The task was to join targets of either 10 or 20mm diameter that were separated by a distance of 62.5 or 125 mm. Constant error in the X and Y planes, peak absolute velocity and acceleration, movement time, the number of pauses and pause time were analysed. Apart from a significantly increased rate of acceleration across all conditions, the children with ADHD demonstrated no temporal difficulties with the task; rather they showed subtle spatial difficulties, possibly suggestive of cerebellar involvement. The children with ADHD showed difficulties in accuracy of movement towards the right. They were less accurate in the X plane when moving towards the right-sided targets over the long distance. Greater variability in target accuracy was shown when moving towards the small target on the right side. The children with ADHD made significantly more pauses on the left target, when preparing the right movement, than the control group. These results suggest that the subtle spatial bias towards the right that has been demonstrated in ADHD in spatial attention also extends into the continuous movement domain.

Intravitreal bevacizumab in the treatment of neovascular age-related macular degeneration, 6- and 9-month results.

PURPOSE: To evaluate 6- and 9-month follow-up data including the effect on vision and anatomic outcome in patients treated with intravitreal bevacizumab for neovascular age-related macular degeneration (AMD). STUDY DESIGN: Interventional consecutive retrospective case series. Patients received intravitreal bevacizumab for the treatment of neovascular AMD including choroidal neovascular membranes, pigment epithelial detachment, and macular haemorrhage. Ophthalmic evaluation included log MAR or Snellen acuity, ophthalmic examination, optical coherence tomography, and fluorescein angiography. Repeat injections were given in the presence of persistent leakage or retinal oedema. Change in vision and foveal thickness from baseline was evaluated using the paired Student's t-test. RESULTS: A total of 112 eyes of 111 patients received injections. Median follow-up was 5 months (range: 1-12 months). Mean log MAR vision pre-injection was 0.84+/-0.03 (n=112); at 3 months was 0.69+/-0.05 (P<0.0001, n=84); at 6 months was 0.74+/-0.06 (P<0.05, n=51); and at 9 months was 0.69+/-0.08 (n=29, P=0.09). Thirteen of 17 patients who received only one injection maintained improved or stable vision at 6 months. Mean baseline foveal thickness was 291+/- 9.72 microm (n=56); at 3 months was 282.7+/-28 (P<0.05, n=31); and at 6 months was 249.7+/-10.3 (P<0.05, n=12). One case of endophthalmitis, three submacular haemorrhages, and three retinal pigment epithelial (RPE) tears occurred. CONCLUSION: Intravitreal bevacizumab is an effective treatment for neovascular AMD, resulting in improved vision and foveal anatomy at 6 months and even up to 9 months. This treatment is well tolerated in the majority of patients but adverse events may include endophthalmitis, RPE tears, and submacular haemorrhage.

Autosomal dominant peripheral cystic retinal patches and non-cystic retinal tufts associated with peripapillary crescents, retinal breaks and uveitis.

PURPOSE: To characterise an Irish kindred with apparent autosomal dominant peripheral retinal lesions and peripapillary crescents associated with retinal breaks and uveitis and assess whether these findings were associated with altered homocysteine metabolism. METHODS: Family members were followed prospectively and regularly examined. Molecular genetic analysis was performed on family members to detect cystathionine beta-synthase (CBS) 307G-S and 5,10-methylenetetrahydrofolate (MTHFR) 677C-T mutations. RESULTS: Over 11 years, 25 family members in four generations were examined, none of whom had significant refractive errors. Fifteen affected individuals had peripheral cystic retinal patches and in some cases non-cystic retinal tufts, associated with peripapillary pigmentation. Mean age at first examination of affected and non-affected individuals was the same. During follow-up the fundal findings remained unchanged in the affected group and no clinical characteristics developed in the unaffected individuals. Two affected siblings had associated uveitis and rhegmatogenous retinal detachment, which were successfully treated, while a third affected individual had a pigmented retinal break not requiring treatment. Heterozygosity for the CBS 307G-S mutation did not segregate with affected individuals while the MTHFR 677C-T mutation was not detected. CONCLUSIONS: This family has previously undescribed fundal findings inherited in an apparent autosomal dominant pattern associated with retinal breaks and uveitis. There is no associated inherited alteration of homocysteine metabolism.

Immunogenetics and clinical phenotype of sympathetic ophthalmia in British and Irish patients.

BACKGROUND/AIMS: Sympathetic ophthalmia (SO) is a classic example of autoimmune disease where human leucocyte antigen (HLA) genomic associations could provide further understanding of mechanisms of disease. This study sought to assess HLA genetic polymorphism in British and Irish patients with SO, and to assess whether HLA gene variants are associated with clinical phenotype or disease severity. METHODS: High resolution DNA based HLA typing using polymerase chain reaction sequence specific primers was performed in 27 patients with SO and 51 matched healthy controls. Clinical phenotype and markers of disease severity were determined prospectively in 17 newly diagnosed patients and from medical record review and repeat clinical examination in 10 previously diagnosed patients. RESULTS: HLA-Cw*03 (p=0.008), DRB1*04 (p=0.017), and DQA1*03 (p=0.014) were significantly associated with SO. For class II alleles at higher resolution, only HLA-DRB1*0404 (relative risk (RR) = 5.6, p = 0.045) was significantly associated with SO. The highest relative risk for any of the associated haplotypes was with HLA-DRB1*0404-DQA1*0301 (RR=10.9, p=0.019). Patients with the DRB1*04-DQA1*03 associated haplotype were significantly more likely to develop SO earlier, with fewer inciting ocular trauma events, and to require more systemic steroid therapy to control inflammatory activity. CONCLUSIONS: Sympathetic ophthalmia is associated with HLA-DRB1*04 and DQA1*03 genotypes in white patients, similar to Japanese patients. Differences in DRB1*04 gene variant associations (-0404 in Britain and Ireland and -0405 in Japan) may have implications for HLA peptide binding in disease initiation. The DRB1*04-DQA1*03 haplotype is a marker of increased SO susceptibility and severity, as in Vogt-Koyanagi-Harada disease, which also has similar clinicopathological and HLA associations.

Classification of the spectrum of Coats' disease as subtypes of idiopathic retinal telangiectasis with exudation.

PURPOSE: An increasing variety of eponymous terms have been used to describe atypical cases of Coats' disease. A group of typical cases of Coats' disease and other cases of differing severity were classified as one of four subtypes of idiopathic retinal telangiectasis with exudation and compared with regard to clinical outcome. METHODS: In a retrospective clinical review patients with typical and atypical Coats' disease were classified as severe, focal, juxtafoveal or associated (with another disease) forms of idiopathic retinal telangiectasis with exudation. RESULTS: 53 eyes in 50 patients were examined of which 62% (n=31) were male. 12 eyes were classified as severe (group 1), 22 focal (group 2), 12 juxtafoveal (group 3) and 7 associated (group 4). The mean age at diagnosis was lowest in group 1 eyes (6.8 years). The best visual acuity at presentation was 6/60 in group 1 whereas high proportions of eyes in the other groups had initial visual acuities of 6/24 or better. In group 1 only one eye was treated, the majority of eyes were blind or had been enucleated whereas 34 (79%) of eyes in the other groups were suitable for treatment and 29 eyes (67%) retained pre-treatment visual acuity or better at last follow-up. CONCLUSIONS: Idiopathic retinal telangiectasis with exudation is a spectrum of disease, which is synonymous with Coats' disease. In this retrospective study eyes with severe idiopathic retinal telangiectasis with exudation corresponding to typical Coats' disease, have poorer vision at presentation, are less suitable for treatment and have worse outcomes than eyes with other subtypes. The spectrum of disease severity seen in idiopathic retinal telangiectasis with exudation may be due to second somatic mutations in genes with an existing germline mutation (the two hit theory) and a mosaic phenotype.

Are isocitrate lyase and phosphoenolpyruvate carboxykinase involved in gluconeogenesis during senescence of barley leaves and cucumber cotyledons?

The aim of this study was to investigate whether gluconeogenesis catalysed by phosphoenolpyruvate carboxykinase (PEPCK) occurs during leaf senescence. This was addressed by determining changes in the abundance and intercellular location of enzymes necessary for gluconeogenesis during the senescence of barley leaves and cucumber cotyledons. PEPCK was never present in barley leaves, despite the presence of large amounts of isocitrate lyase (ICL), a key enzyme of the glyoxylate cycle, and of its product, glyoxylate. Although PEPCK was present in non-senescent cucumber cotyledons, its abundance declined during senescence. Throughout senescence, PEPCK was only present in the trichomes and vasculature, whereas ICL was located in mesophyll cells. Pyruvate,Pi dikinase (PPDK) which, in concert with NAD(P)-malic enzyme, is also capable of catalysing gluconeogenesis, was present in non-senescent barley leaves and cucumber cotyledons, but in both plants its abundance decreased greatly during senescence. The abundance of ICL was greatly reduced in senescing detached barley leaves by either illumination or by co-incubation with sucrose, and greatly increased in darkened attached barley leaves. These results argue against the large-scale occurrence of gluconeogenesis during senescence catalysed either by PEPCK or PPDK. In cucumber cotyledons, PEPCK may play a role in metabolic processes linked to the export of amino acids, a role in which phosphoenolpyruvate carboxylase may also be involved. The amount of ICL was increased by starvation and during senescence may function in the conversion of lipids to organic acids, which are then utilised in the mobilisation of amino acids from leaf protein.