Bringing the patient's perspectives forward in drug development and health-care evaluation.

INTRODUCTION: For many years, psychologists and other social scientists have been pushing for the individual patient's perspective - priorities, needs, feelings, and functioning - to be incorporated into drug development. This is usually achieved through the use of patient-reported outcome measures (PROMs) in clinical trials. AREAS COVERED: This paper discusses some key issues in the use of PROM data as the sole method of generating information about the patient's perspective and outlines the relevance of narrative evidence to enhance understanding and interpretation of PROM data. EXPERT OPINION: The development and use of PROMs situates them at the vertex of two very different trends in medicine: patient-centered care and standardization. Indeed, the application of PROMs - which pull in the direction of standardization - results in a narrow conception of evidence by overriding the subjectivity of individual experiences, beliefs, and judgments. Without additional context, PROM data cannot easily support individual patient-level care. When collected systematically and with an interpretive phenomenological approach, narrative data can contain valuable information about the patient experience that numerical ratings from PRO measures do not capture.

Patients' experiences of Parkinson's disease: a qualitative study in glucocerebrosidase and idiopathic Parkinson's disease.

BACKGROUND: Approximately 7-10% of Parkinson's disease (PD) patients carry a GBA (Glucocerebrosidase) mutation (GBA-PD patients), which may influence the disease's clinical course. OBJECTIVES: This study aimed to explore the patient experience of GBA-PD and identify the most important symptoms and impacts to inform clinical trial measurement strategies. METHODS: Twenty PD patients (n = 15 GBA-PD; n = 5 idiopathic-PD) participated in qualitative interviews which explored concepts spontaneously reported or identified through a literature review. Telephone interviews with five expert clinicians included discussion of a preliminary conceptual model derived from literature. Verbatim transcripts were thematically analysed. RESULTS: Thirty symptoms reported by patients were categorized as motor, non-motor, and cognitive/psychiatric. Tremor (n = 13), memory loss (n = 13), rigidity/stiffness (n = 11), and speech problems (n = 11) were considered the most important and impactful symptoms by GBA-PD patients, although other symptoms were also relevant to the majority of patients. Key impacts included: sleep disturbances (n = 13), handwriting changes (n = 13), reduced social interaction (n = 12), dyskinesia (n = 10), depressed mood (n = 9), and fear of falling (n = 8). Key symptoms and impacts reported by GBA-PD patients were consistent with those reported by idiopathic-PD patients. Clinician interview results supported the patient findings, although some clinicians indicated that cognitive/psychiatric symptoms may present earlier in GBA-PD patients. The concepts emerging from the research informed updates to a conceptual model of GBA-PD patients' disease experience. CONCLUSIONS: The findings provide in-depth understanding of the patient experience of GBA-PD. The findings confirm that the concepts relevant to assess in GBA-PD are consistent with those relevant to assess in idiopathic-PD; however, greater consideration of cognitive/psychiatric symptoms may be warranted in GBA-PD populations.

Correction: Self-assembled fibrillar networks comprised of a naturally-occurring cyclic peptide-LOB3.

[This corrects the article DOI: 10.1039/C6RA05154E.].

A novel formulation significantly increases the cytotoxicity of flaxseed orbitides (linusorbs) LOB3 and LOB2 towards human breast cancer MDA-MB-231 cells.

Flaxseed orbitides (linusorbs) are a family of N to C linked bioactive cyclic octa-, nona-, and decapeptides present in flaxseed oil. They are highly hydrophobic and thermally stable. Our previous studies showed that [1-9-NαC]-linusorb B3 (LOB3) and [1-9-NαC]-linusorb B2 (LOB2) exhibited cytotoxic effects towards human breast cancer HER2-subtype Sk-Br-3 cells at a concentration of ~400 µM. However, this high concentration significantly limits their potential clinical applications. In the current study, we developed a novel polyethylene glycol-based formulation for linusorbs and showed that both LOB3 and LOB2, especially LOB3, exhibited strong cytotoxicity towards human breast cancer triple-negative-subtype MDA-MB-231 cells at low nanomolar concentrations.

Peak Pruritus Numerical Rating Scale: psychometric validation and responder definition for assessing itch in moderate-to-severe atopic dermatitis.

BACKGROUND: Moderate-to-severe atopic dermatitis (AD) is a chronic disease characterized by intense, persistent and debilitating itch, resulting in sleep deprivation, signs of anxiety and depression, impaired quality of life and reduced productivity. The Peak Pruritus Numerical Rating Scale (NRS) was developed and validated as a single-item, patient-reported outcome (PRO) of itch severity. OBJECTIVES: To describe the content validity and psychometric assessment (test-retest reliability, construct validity, known-groups validity, sensitivity to change) of the Peak Pruritus NRS, and to derive empirically a responder definition to identify adults with a meaningful change in itch. METHODS: Content validity was assessed through in-depth patient interviews. Psychometric assessments used data from phase IIb and phase III dupilumab clinical trials and included test-retest reliability, construct validity, known-groups validity and sensitivity to change in patients with moderate-to-severe AD. RESULTS: Interview participants indicated that the Peak Pruritus NRS was a relevant, clear and comprehensive assessment of itch severity. Peak Pruritus NRS scores showed large, positive correlations with existing PRO measures of itch, and weak or moderate correlations with clinician-reported measures assessing objective signs of AD. Peak Pruritus NRS score improvements were highly correlated with improvements in other itch PROs, and moderately correlated with improvements in clinician-reported measures assessing objective signs of AD. The most appropriate threshold for defining a clinically relevant, within-person response was ≥ 2-4-point change in the Peak Pruritus NRS. CONCLUSIONS: The Peak Pruritus NRS is a well-defined, reliable, sensitive and valid scale for evaluating worst itch intensity in adults with moderate-to-severe AD.

Creating a personalized evaluation framework for patient-reported outcomes: an illustration using the EQ-5D visual analogue scale.

BACKGROUND: This paper outlines the creation of an intuitive, personalized evaluation framework for Patient-Reported Outcomes, using the EQ-5D visual analog scale (VAS) as an illustration. METHODS: A draft framework asked patients to divide and label the EQ-5D-VAS into different levels or categories of health. Comprehension of the framework and patient-defined health level labels, and how they map onto the EQ-5D-VAS, were tested through in-person, semi-structured interviews with individuals self-reporting cardiovascular disease. Interviews were conducted in three waves, with the framework revised between waves. RESULTS: Analyses included 14 participants. Eight participants (57.1%) felt that four levels of health were appropriate and there was general agreement on the labels; Poor, Fair, Good, and Excellent. There was substantial variability in where patients drew lines to indicate the level boundaries; Poor ranged between 0 and 50; Fair 10-75; Good 40-91; Excellent 60-100. In wave 3, all participants demonstrated appropriate comprehension of the framework. CONCLUSIONS: The framework was well understood. The wide range of margins and the extent of overlap between the levels provide strong evidence for the relevance of the personalized evaluation framework approach, and specifically a personalized EQ-5D-VAS evaluation framework, to better understand and interpret each individual's response to the item.

Treatment satisfaction in people with type 2 diabetes mellitus treated with once-weekly dulaglutide: data from the AWARD-1 and AWARD-3 clinical trials.

AIMS: To compare treatment satisfaction among people with type 2 diabetes receiving dulaglutide 1.5 mg and dulaglutide 0.75 mg (a once-weekly, long-acting, glucagon-like peptide-1 receptor agonist) with those receiving either exenatide or placebo (AWARD-1 study) or metformin (AWARD-3 study) over 52 weeks. METHODS: The Diabetes Treatment Satisfaction Questionnaire status version (DTSQs) and change version (DTSQc) were used to evaluate total treatment satisfaction and perceived frequency of hyperglycaemia and hypoglycaemia. RESULTS: In the AWARD-1 study, significant improvements from baseline were observed in total DTSQs score for both dulaglutide doses (26 and 52 weeks) and exenatide (26 weeks). The improvement was significantly greater with both dulaglutide doses compared with placebo (26 weeks) and exenatide (26 and 52 weeks). The perceived frequency of hyperglycaemia was lower for all groups at 26 and 52 weeks compared with baseline. The improvement was greater with both dulaglutide doses and exenatide compared with placebo at 26 weeks, and was also greater with both dulaglutide doses compared with exenatide at 26 and 52 weeks. The exenatide group had an increase in perceived frequency of hypoglycaemia at 26 and 52 weeks. In the AWARD-3 study, significant improvements from baseline were observed for total DTSQs scores in all groups at 26 and 52 weeks. Perceived frequency of hyperglycaemia was lower for all groups at 26 and 52 weeks compared with baseline, and this improvement was greater with both dulaglutide doses compared with metformin at 52 weeks. CONCLUSIONS: Dulaglutide was associated with improvements in treatment satisfaction and a decrease in perceived frequency of hyperglycaemia.

Macro- and microvascular outcomes in patients with type 2 diabetes treated with rapid-acting insulin analogues or human regular insulin: a retrospective database analysis.

To investigate the risk of macro- and microvascular complications in patients with type 2 diabetes receiving rapid-acting insulin analogues (IA) or human regular insulin (HI).General practice diabetes patients with continuous prescription of any IA or HI for ≥3 years were selected from the German Disease Analyzer database (IMS Health). Logistic and Cox regression models were applied to analyze the incidence and time to onset of vascular outcomes (IA vs. HI).2764 patients on IA (insulin lispro, glulisine, aspart) and 4193 patients on HI were included (age, mean [SD]: 61.0 [11.3] and 64.7 [10.5] years, follow-up [Q1,Q3]: 4.6 [3.7,6.1] and 4.7 [3.7,5.9] years). No significant differences were detected between IA and HI regarding the incidence of vascular complications (OR [95%CI]: macrovascular 0.92 [0.72-1.18], microvascular 0.95 [0.77-1.17]) or regarding time to their onset, after adjustment for sex, age, comorbidities and time on IA/HI, or by propensity-score-based matching. However, in an additional short-term analysis (median [Q1,Q3] follow-up (IA 2.9 [1.2,4.6], HI 2.4 [0.8,4.4] years) of a larger sample (no continuous insulin treatment required) with more comorbidities, time to onset of macrovascular complications was significantly longer for AI than HI (HR 0.88 [0.81-0.97], p=0.009; microvascular complications: no difference).After long-term continuous treatment with IA or HI under real-life conditions, there was no different risk of macro- or microvascular complications, contradicting previous short-term analyses. Further prospective studies are needed to clarify whether selection bias may have been introduced by using strict entry criteria.

Rates and risk of hospitalisation among patients with type 2 diabetes: retrospective cohort study using the UK General Practice Research Database linked to English Hospital Episode Statistics.

AIMS: To investigate the rates and risk of hospitalisations in patients with type 2 diabetes (T2D) mellitus in England. METHODS: This retrospective population-based cohort study used computerised records from the General Practice Research Database linked to Hospital Episode Statistics data in England. Patients with T2D from January 2006 to December 2010 were selected. Primary outcome measures were all-cause, non-diabetes-related, diabetes-related and hypoglycaemia-related hospitalisations. Factors associated with all-cause and diabetes-related hospitalisations were investigated with Cox's proportional hazards models. RESULTS: Amongst 97,689 patients with T2D, approximately 60% had at least one hospitalisation during the 4-year study period. Rates of hospitalisation were as follows: all-cause, 33.9 per 100 patient-years (pt-yrs); non-diabetes-related, 29.1 per 100 pt-yrs; diabetes-related, 18.8 per 100 pt-yrs and hypoglycaemia, 0.3 per 100 pt-yrs. The risk of all-cause hospitalisation increased with hospitalisation in the previous year, insulin use and the presence of major comorbidities. The risk of a diabetes-related hospitalisation increased with age, female gender, insulin use, chronic renal insufficiency, hypoglycaemia (as diagnosed by a general practitioner) and diabetes-related hospitalisation in the previous year. CONCLUSIONS: Patients with T2D are hospitalised at a considerably high rate for causes directly related with diabetes complications and stay longer in hospital. History of hospitalisation and complications of diabetes were found to be predictive of inpatient hospitalisations suggesting previous hospitalisation episodes could serve as points of intervention. This study highlights important areas for healthcare intervention and provides a reminder for vigilance when risk factors for hospitalisation in patients with T2D are present.

Patient-reported outcomes following islet cell or pancreas transplantation (alone or after kidney) in Type 1 diabetes: a systematic review.

AIMS: For selected individuals with complex Type 1 diabetes, pancreatic islet transplantation (IT) offers the potential of excellent glycaemic control without significant hypoglycaemia, balanced by the need for ongoing systemic immunosuppression. Increasingly, patient-reported outcomes (PROs) are considered alongside biomedical outcomes as a measure of transplant success. PROs in IT have not previously been compared directly with the closest alternate treatment option, pancreas transplant alone (PTA) or pancreas after kidney (PAK). METHODS: We used a Population, Intervention, Comparisons, Outcomes (PICO) strategy to search Scopus and screened 314 references for inclusion. RESULTS: Twelve studies [including PRO assessment of PAK, PTA, islet-after kidney (IAK) and islet transplant alone (ITA); n = 7-205] used a total of nine specified and two unspecified PRO measures. Results were mixed but identified some benefits which remained apparent up to 36 months post-transplant, including improvements in fear of hypoglycaemia, as well as some aspects of diabetes-specific quality of life (QoL) and general health status. Negative outcomes included short-term pain associated with the procedure, immunosuppressant side effects and depressed mood associated with loss of graft function. CONCLUSIONS: The mixed results may be attributable to limited sample sizes. Also, some PRO measures may lack sensitivity to detect actual changes, as they exclude issues and domains of life likely to be important for QoL post-transplantation and when patients may no longer perceive themselves to have diabetes. Thus, the full impact of islet/pancreas transplantation (alone or after kidney) on QoL is unknown. Furthermore, no studies have assessed patient satisfaction, which may highlight further advantages and disadvantages of transplantation.

Not all roads lead to Rome-a review of quality of life measurement in adults with diabetes.

AIMS: Quality of life (QoL) is recognized widely as an important health outcome in diabetes, where the burden of self-management places great demands on the individual. However, the concept of QoL remains ambiguous and poorly defined. The aim of our review is to clarify the measurement of QoL in terms of conceptualization, terminology and psychometric properties, to review the instruments that have been used most frequently to assess QoL in diabetes research and make recommendations for how to select measures appropriately. METHODS: A systematic literature search was conducted to identify the ten measures most frequently used to assess QoL in diabetes research (including clinical trials) from 1995 to March 2008. RESULTS: Six thousand and eight-five abstracts were identified and screened for instrument names. Of the ten instruments most frequently used to assess 'QoL', only three actually do so [i.e. the generic World Health Organization Quality of Life (WHOQOL) and the diabetes-specific Diabetes Quality of Life (DQOL) and Audit of Diabetes-Dependent Quality of Life (ADDQoL)]. Seven instruments more accurately measure health status [Short-Form 36 (SF-36), EuroQoL 5-Dimension (EQ-5D)], treatment satisfaction [Diabetes Treatment Satisfaction Questionnaire (DTSQ)] and psychological well-being [Beck Depression Inventory (BDI), Hospital Anxiety and Depression Scale (HADS), Well-Being Questionnaire (W-BQ), Problem Areas in Diabetes (PAID)]. CONCLUSIONS: No single measure can suit every purpose or application but, when measures are selected inappropriately and data misinterpreted, any conclusions drawn are fundamentally flawed. If we value QoL as a therapeutic goal, we must ensure that the instruments we use are both valid and reliable. QoL assessment has the proven potential to identify ways in which treatments can be tailored to reduce the burden of diabetes. With careful consideration, appropriate measures can be selected and truly robust assessments undertaken successfully.

Cyclo-linopeptide A methanol solvate.

Crystals of the title compound, C(57)H(85)N(9)O(9)·CH(4)O, the methanol solvate of a nine peptide polypeptide, cyclo-(Pro-Pro-Phe-Phe-Leu-Ile-Ile-Leu-Val), were obtained after separation of the cyclic peptide from flax oil. The cyclo-linopeptide A (CLP-A) mol-ecules are linked in chains along the a axis by N-H⋯O hydrogen bonds. Each methanol O atom is hydrogen bonded to one O atom and two N-H groups in the same CLP-A mol-ecule. There are a total of eight hydrogen bonds in each CLP-A-MeOH unit.

Synthesis and characterization of vegetable oil derived esters: evaluation for their diesel additive properties.

Trans-esterification of four vegetable oils; canola oil, greenseed canola oil from heat-damaged seeds, processed waste fryer grease and unprocessed waste fryer grease, was carried out using methanol, and KOH as catalyst. The methyl esters of the corresponding oils were separated from the crude glycerol, purified, and characterized by various methods to evaluate their densities, viscosities, iodine values, acid numbers, cloud points, pour points and gross heat of combustion, fatty acid and lipid compositions, lubricity properties, and thermal properties. The fatty acid composition suggests that 80-85% of the ester was from unsaturated acids. Substantial decrease in density and viscosity of the methyl esters compared to their corresponding oils suggested that the oils were in their mono or di glyceride form. The lubricity of the methyl esters, when blended at 1 vol% treat rate with ISOPAR M reference fuel, showed that the canola methyl ester enhanced the fuel's lubricity number. From the analyses performed, it was determined that the ester with the most potential for being an additive or a substitute for diesel fuel is the canola methyl ester, whose physical and chemical characteristics are similar to diesel fuel.

Preparation and characterization of bio-diesels from various bio-oils.

Methyl, ethyl, 2-propyl and butyl esters were prepared from canola and linseed oils through transesterification using KOH and/ or sodium alkoxides as catalysts. In addition, methyl and ethyl esters were prepared from rapeseed and sunflower oils using the same catalysts. Chemical composition of the esters was determined by HPLC for the class of lipids and by GC for fatty acid compositions. The bio-diesel esters were characterized for their physical and fuel properties including density, viscosity, iodine value, acid value, cloud point, pure point, gross heat of combustion and volatility. Methyl and ethyl esters prepared from a particular vegetable oil had similar viscosities, cloud points and pour points, whereas methyl, ethyl, 2-propyl and butyl esters derived from a particular vegetable oil had similar gross heating values. However, their densities, which were 2 7% higher than those of diesel fuels, statistically decreased in the order of methyl approximately 2-propyl > ethyl > butyl esters. Butyl esters showed reduced cloud points (-6 degrees C to -10 degrees C) and pour points (-13 degrees C to -16 degrees C) similar to those of summer diesel fuel having cloud and pour points of -8 degrees C and -15 degrees C, respectively. The viscosities of bio-diesels (3.3-7.6 x 10(-4) Pa s at 40 degrees C) were much less than those of pure oils (22.4-45.1 x 10(-4) Pa s at 40 degrees C) and were twice those of summer and winter diesel fuels (3.50 and 1.72 x 10(-4) Pa s at 40 degrees C), and their gross heat contents of approximately 40 MJ/kg were 11% less than those of diesel fuels (approximately 45 MJ/kg). For different esters from the same vegetable oil, methyl esters were the most volatile, and the volatility decreased as the alkyl group grew bulkier. However, the bio-diesels were considerably less volatile than the conventional diesel fuels.

An example of intron junctional sliding in the gene families encoding squalene monooxygenase homologues in Arabidopsis thaliana and Brassica napus.

Sequences of three Arabidopsis thaliana and two Brassica napus cDNAs encoding squalene monooxygenase homologues (Sqp1 and Sqp2) are reported. Southern analysis confirmed that these cDNAs are derived from small gene families in both species. Expression analysis indicates that Sqp1 genes in B. napus are strongly expressed in leaves but not roots or developing seeds. Comparison of cDNA and genomic sequences indicate that the 3' splice site of an intron in these genes has undergone junctional sliding. The evolutionary significance of this phenomenon is discussed.

Structure-Activity Relationships of Abscisic Acid Analogs Based on the Induction of Freezing Tolerance in Bromegrass (Bromus inermis Leyss) Cell Cultures.

The induction of freezing tolerance in bromegrass (Bromus inermis Leyss) cell culture was used to investigate the activity of absisic acid (ABA) analogs. Analogs were either part of an array of 32 derived from systematic alterations to four regions of the ABA molecule or related, pure optical isomers. Alterations were made to the functional group at C-1 (acid replaced with methyl ester, aldehyde, or alcohol), the configuration at C-2, C-3 (cis double bond replaced with trans double bond), the bond order at C-4, C-5 (trans double bond replaced with a triple bond), and ring saturation (C-2', C-3' double bond replaced with a single bond so that the C-2' methyl and side chain were cis). All deviations in structure from ABA reduced activity. A cis C-2, C-3 double bond was the only substituent absolutely required for activity. Overall, acids and esters were more active than aldehydes and alcohols, cyclohexenones were more active than cyclohexanones, and dienoic and acetylenic analogs were equally active. The activity associated with any one substituent was, however, markedly influenced by the presence of other substituents. cis, trans analogs were more active than their corresponding acetylenic analogs unless the C-1 was an ester. Cyclohexenones were more active than cyclohexanones regardless of oxidation level at C-1. An acetylenic side chain decreased the activity of cyclohexenones but increased the activity of cyclohexanones relative to their cis, trans counterparts. Trends suggested that for activity the configuration at C-1' has to be the same as in (S)-ABA, in dihydro analogs the C-2'-methyl and the side chain must be cis, small positional changes of the 7'-methyl are tolerable, and the C-1 has to be at the acid oxidation level.

Water relation parameters of embryogenic cultures and seedlings of larch.

Changes in the water relations parameters of developing somatic embryogenic and xygotic European larch (Larix decidua) were studied. Water release curves were generated by suspending tissue samples over unsaturated NaCl solutions until they reached vapor equilibration with the surrounding air. Twenty solutions were used whose water potentials ranged from -0.05 to -10 MPa. Water release curves were obtained by plotting paired values of tissue relative water content (RWC) and solution potential. Curves were derived for embryonic larch at various stages of development and for hypocotyls and roots from germinated zygotic and somatic embryos. The ability to resist dehydration increased markedly with development. Stage 1 tissue, which consisted of clusters of loosely associated nonchlorophyllous cells, had extremely low bulk elastic modulus (epsilon) (1.91 MPa) and apoplastic water content (A) (0.023), relatively high osmotic potential (Psi(pi)) (-0.53 MPa), and lost turgor at 0.56 RWC. In contrast, mature embryoids with primary roots, hypocotyl, and cotyledons (stage 3) had an almost 4-fold increase in A (0.089), significantly higher epsilon (3.49 MPa), and lower Psi(pi) (-0.88 MPa) and lost turgor at 0.66 RWC. Hypocotyl tissue from germinated somatic embryos lost turgor at 0.74 RWC and had higher epsilon, A, and solute accumulation than pregerminated tissue. Hypocotyl tissue resisted dehydration more strongly than root tissue, and differences between root and hypocotyl water relation parameters were more pronounced in xygotic than in somatic seedlings. Highest dehydration resistance was in zygotic hypocotyls. The characterization of the water relations of tissue cultures should allow the development of more consistent and reliable desiccation protocols to induce maturation of embryos and produce synchronously germinating seed.

Monoclonal antibody recognition of abscisic Acid analogs.

Specificities of three monoclonal antibodies (15-I-C5, DBPA 1, and MAC 62) raised against the plant hormone (S)-(+)-abscisic acid (ABA) have been compared. Immunological cross-reactivities against fifteen biologically active analogs of ABA were measured. The ABA analogs were altered at one or more of four positions: the double bonds in the ring, at C-2 C-3 and at C-4 C-5, and in the oxidation level at C-1. Several analogs were optically active with chiral centers at C-1' and C-2'. For cross-reactivity, all three monoclonal antibodies required the carboxylic acid group, and the cis configuration of the double bond at C-2 C-3 of the ABA molecule. Monoclonals 15-I-C5 and DBPA 1 required the entire ABA sidechain from the C-1 to C-1', but these monoclonals did cross-react with analogs with the ring double bond reduced and the C-2' methyl cis to the sidechain. Only MAC 62 recognized analogs containing an acetylene at C-4 C-5. MAC 62 had more strict requirements for the ring double bond, but gave some cross-reactivity with acetylenic analogs having a saturated ring. All three monoclonals had higher specificity for analogs having the same absolute configuration at C-1' as (S)-(+)-ABA. This work provides new information about the spatial regions of the ABA molecule that elicit immunological recognition, and serves as a basis for future investigations of the ABA receptor using ABA analogs and anti-idiotypic antibodies.

Identification of Proteins Correlated with Increased Freezing Tolerance in Bromegrass (Bromus inermis Leyss. cv Manchar) Cell Cultures.

Cellular and extracellular protein profiles from Bromus inermis Leyss. cv Manchar cell suspension cultures cold hardened by low temperature and abscisic acid (ABA) treatment were analyzed by one- and two-dimensional sodium dodecyl sulfate polyacrylamide gel electrophoresis. Cellular proteins (25, 165, 190, and 200 kilodaltons) increased by low temperature growth and cellular proteins (20, 25, 28, 30, 32, 37, 40, 45, 200 kilodaltons) increased by exogenous ABA treatment were identified. Low temperature treatment inhibited the synthesis of a 22 kilodalton protein and ABA treatment resulted in the synthesis of two extracellular proteins (17 and 21 kilodaltons). Low temperature and ABA-induced hardening conditions increased or induced a 25 and a 200 kilodalton protein. The 25 and a 30 kilodalton protein previously shown to be enriched by ABA-induced hardening conditions at both 3 and 23 degrees C temperatures co-fractionated with the crude membrane fraction (30,000g sediment). The 200 kilodalton protein was detected in the 30,000g supernatant. Two-dimensional analysis of the crude membrane fraction resolved the 30 kilodalton protein band into a major polypeptide with an apparent isoelectric point of 6.85.

Protein Synthesis in Bromegrass (Bromus inermis Leyss) Cultured Cells during the Induction of Frost Tolerance by Abscisic Acid or Low Temperature.

Bromus inermis Leyss cell cultures treated with 75 micromolar abscisic acid (ABA) at both 23 and 3 degrees C developed more freezing resistance than cells cultured at 3 degrees C. Protein synthesis in cells induced to become freezing tolerant by ABA and low temperature was monitored by [(14)C]leucine incorporation. Protein synthesis continued at 3 degrees C, but net cell growth was stopped. Most of the major proteins detected at 23 degrees C were synthesized at 3 degrees C. However, some proteins were synthesized only at low temperatures, whereas others were inhibited. ABA showed similar effects on protein synthesis at both 23 and 3 degrees C. Comparative electrophoretic analysis of [(14)C]leucine labeled protein detected the synthesis of 19, 21 and 47 kilodalton proteins in less than 8 hours after exposure to exogenous ABA. Proteins in the 20 kilodalton range were also synthesized at 3 degrees C. In addition, a 31 kilodalton protein band showed increased expression in freezing resistant ABA treated cultures after 36 hours growth at both 3 and 23 degrees C. Quantitative analysis of [(14)C]leucine labeled polypeptides in two-dimensional gels confirmed the increased expression of the 31 kilodalton protein. Two-dimensional analysis also resolved a 72 kilodalton protein enriched in ABA treated cultures and identified three proteins (24.5, 47, and 48 kilodaltons) induced by low temperature growth.