Characteristics of heart failure with a preserved ejection fraction in black South African patients

Background

Heart failure with a preserved ejection fraction (HFpEF) is common in the elderly (≥75 years) and associated with arterial stiffness. The mean age of HFpEF presentation is lower (40-55 years) in sub-Saharan Africa. No clinical study has been conducted on HFpEF in identifying and characterising this phenotype at a younger age, moreover in a South African black population where the risk of HFpEF is two times higher than in other ethnic groups. This study investigated the characteristics of HFpEF in a black South African population, the biochemical markers that predict HFpEF and cardiac structural changes in this HF phenotype.

Methods

Sixty-six participants with HFpEF and 213 controls were enrolled. All participants gave informed consent and completed a standardised questionnaire. Echocardiographic, anthropometric, central haemodynamic measurements, pulse wave velocity (PWV) and biomarker analysis were done.

Results

The mean age of HFpEF participants was 54.88 ± 13.51 years. Most of the participants (76 %) were between 20 and 64 years, while only 24 % were older. HFpEF participants were hypertensive, and more obese with increased incidence of alcohol consumption. PWV was increased in HFpEF (9.97 ± 2.78 m/s) when compared to participants without HFpEF (6.11 ± 2.18 m/s), p < 0.0001. There were no significant associations between central haemodynamic parameters, N-terminal pro B-type natriuretic peptide (NT-proBNP) (p = 0.9746), and galectin-3 (p = 0.2166). NT-proBNP, but not galectin-3, was associated with left ventricular hypertrophy (p = 0.0002) and left atrial diameter (p = 0.0005).

Conclusion

HFpEF in South Africa is predominant in obese young to middle-age individuals with arterial stiffness and who consume alcohol regularly. NT-proBNP could be used to diagnose HFpEF, however, should be interpreted with caution in populations with a high prevalence of obesity.

Impact of a Cancer Survivorship Program on Well-Being and Community Involvement: Role of OT and Future Directions

Date Presented 04/03/2022

This qualitative phenomenological study explored the lived experiences of cancer survivors in a community-based, interprofessional survivorship program and explains further exploration needs for OT. Personal themes describing impact on the individuals included (1) journey of spiritual and emotional healing, (2) growing into a new sense of self, and (3) moving from survival to life. Relational themes included (1) building a community of caring and connection and (2) embracing the value of altruism.

Primary Author and Speaker: Lynne Murphy

Contributing Authors: Kendall Ellis, Nicole Fox, Sarah Lee, Rachel Lennon, Gloria Norton

With a new role comes new responsibilities: interviews to explore what Emergency Department Pharmacist Practitioners know and understand about patient safeguarding

Introduction

In the UK, pharmacists with additional clinical skills now work in emergency departments (1). Known as Emergency Department Pharmacist Practitioners (EDPPs), the role was developed in response to a shortage of doctors and nurses. EDPPs carry out activities typical of traditional hospital pharmacists, but also novel ‘practitioner’ activities such as examining patients. They also may act as designated care providers with overall responsibility for patients, which includes a responsibility to safeguard patients (children and vulnerable adults) from harm – as is required of other healthcare professionals who take on that role. The initial safeguarding process comprises four stages: recognition, ensuring safety, documentation and escalation. Professional competence, i.e. to safeguard patients, is underpinned by knowledge of the subject, but also the ability to apply that knowledge (2).

Aim

To investigate what EDPPs know and understand about safeguarding vulnerable children and adults.

Methods

Past and current students of an ‘Advanced Specialist Training in Emergency Medicine’ programme, which delivers additional clinical skills to pharmacists, were interviewed to explore their knowledge and understanding of safeguarding. Interview questions were developed from review of relevant literature, as were four vignettes which were used to further explore participants’ understanding i.e. apply their knowledge of safeguarding to realistic scenarios. Vignettes concerned victims of: theft, sexual abuse, physical abuse and a medication error. A Social Worker reviewed the vignettes for plausibility, suggesting changes e.g. to victim characteristics. The interview schedule and vignettes were then piloted by two acute medicine pharmacists. For analysis, interview transcripts were reviewed with template analysis used to code data to four a priori themes (stages of the initial safeguarding process), and new themes that emerged throughout the process.

Results

Thirteen EDPPs were interviewed (four in 2016, and then a further nine in 2019 following delays due to competing research commitments). In addition to the four a priori themes, a further six themes were identified: scope of safeguarding; responsibility to safeguard; resources and setting; education, training and experiential learning; multidisciplinary working and communication; and culture. Overall, participants had a broad and often detailed knowledge of safeguarding. All four stages were frequently described which demonstrates EDPPs awareness of how safeguarding concerns are both recognised and responded to. Somewhat unsurprisingly, participants were generally more comfortable when responding to medicines related concerns although whether these should be reported via safeguarding or error systems is currently unclear. Several participants were more involved with the formal escalation of issues, and one participant had safeguarding issues escalated to them and had given evidence in court.

Conclusion

Although interview phases were three years apart, no thematic differences were identified between these phases and thematic saturation was also achieved. EDPPs interviewed were aware of the different types of maltreatment and the safeguarding process. Safeguarding training for pharmacists should include a focus on the importance of good inter-professional communication. Training should also include information about the types of medication error (e.g. type and severity) that require escalation via safeguarding, but these first need to be confirmed through future research.

References

(1) Greenwood D, Tully MP, Martin S, Steinke D. The description and definition of Emergency Department Pharmacist Practitioners in the United Kingdom (the ENDPAPER study). International journal of clinical pharmacy. 2019 Apr;41(2):434-44.

(2) James KL, Davies JG, Kinchin I, Patel JP, Whittlesea C. Understanding vs. competency: the case of accuracy checking dispensed medicines in pharmacy. Advances in health sciences education. 2010 Dec;15(5):735-47.

Impact of a Cancer Survivorship Program on Well-Being and Community Involvement: Role of OT and Future Directions

Date Presented Accepted for AOTA INSPIRE 2021 but unable to be presented due to online event limitations.

This qualitative phenomenology explored the lived experiences of cancer survivors in a community-based, interprofessional survivorship program and explains further exploration for inclusion of OT. Personal themes describing impact on the individuals included (1) journey of spiritual and emotional healing, (2) growing into a new sense of self, and (3) moving from survival to life. Relational themes included (1) building a community of caring and connection and (2) embracing the value of altruism.

Primary Author and Speaker: Lynne Murphy

Additional Authors and Speakers: Kendall Ellis, Nicole Fox, Sarah Lee, Rachel Lennon, and Gloria Norton

Modeling Commodity Flow in the Context of Invasive Species Spread: Study of Tuta absoluta in Nepal

Trade and transport of goods is widely accepted as a primary pathway for the introduction and dispersal of invasive species. However, understanding commodity flows remains a challenge owing to its complex nature, unavailability of quality data, and lack of systematic modeling methods. A robust network-based approach is proposed to model seasonal flow of agricultural produce and examine its role in pest spread. It is applied to study the spread of Tuta absoluta, a devastating pest of tomato in Nepal. Further, the long-term establishment potential of the pest and its economic impact on the country are assessed. Our analysis indicates that regional trade plays an important role in the spread of T. absoluta. The economic impact of this invasion could range from USD 17-25 million. The proposed approach is generic and particularly suited for data-poor scenarios.

Total arsenic, inorganic arsenic, and other elements concentrations in Italian rice grain varies with origin and type

Rice is comparatively efficient at assimilating inorganic arsenic (Asi), a class-one, non-threshold carcinogen, into its grain, being the dominant source of this element to mankind. Here it was investigated how the total arsenic (Ast) and Asi content of Italian rice grain sourced from market outlets varied by geographical origin and type. Total Cr, Cd Se, Mg, K, Zn, Ni were also quantified. Ast concentration on a variety basis ranged from means of 0.18 mg kg(-1) to 0.28 mg kg(-1), and from 0.11 mg kg(-1) to 0.28 mg kg(-1) by production region. For Asi concentration, means ranged from 0.08 mg kg(-1) to 0.11 mg kg(-1) by variety and 0.10 mg kg(-1) to 0.06 mg kg(-1) by region. There was significant geographical variation for both Ast and Asi; total Se and Ni concentration; while the total concentration of Zn, Cr, Ni and K were strongly influenced by the type of rice.

Evaluation of a novel electropositive filter for the concentration of viruses from diverse water matrices

Human enteric viruses are important agents of waterborne illness. They are diffusely distributed in environmental waters, necessitating concentration of tens to hundreds of litres for effective detection. This study evaluates the novel ViroCap disposable capsule filter for concentration of coliphage MS2 and poliovirus (PV1) from deionised (DI) water and artificial seawater, as well as natural ground, surface, and seawater. Retention and recoveries for the ViroCap were compared with two well-characterised filters: the 1MDS for DI water, and the OptiCap XL for artificial seawater. The mean adsorption for MS2 by the ViroCap was 88%. Recovery of MS2 was significantly greater (p< or=0.01) than alternative filters tested: 65% from DI water and 63% from artificial seawater, compared to 30% for the 1MDS and 15% for the OptiCap for the respective matrices. Recovery of PV1 from DI water (37%) was similar to that of the 1MDS (51%). PV1 recoveries from artificial seawater were significantly greater (p< or =0.01) for the ViroCap (44%) than the OptiCap (11%). Recovery of MS2 from seeded environmental samples yielded 44% from groundwater, 53% from surface water, and 51% from seawater. ViroCap disposable filter is efficient for concentrating MS2 and PV1 from diverse matrices and is robust across a range of ionic concentrations.

Association analysis of beta2 adrenoceptor polymorphisms with hypertension in a Black African population

OBJECTIVE

To determine whether or not beta2 adrenoceptor polymorphism is a risk factor for the development of hypertension in a Black South African population.

BACKGROUND

Attenuated vasodilator responses to endogenous catecholamines may contribute to the aetiology of hypertension. Downregulation of beta2 adrenoreceptors (beta2AR) following stimulation with agonists is determined in part by variation at the beta2AR gene locus. The Glu27 beta2AR genotype results in attenuated downregulation compared with the wild-type Gln27 receptor, whereas Gly16 exhibits enhanced down-regulation compared to Arg16. Possible racial differences in the prevalence of the beta2AR polymorphisms may be an explanation for the blunted responses to isoprenaline and the increased prevalence of hypertension in Black African populations.

METHODS

One hundred and ninety-two unrelated hypertensives and 123 normotensives of Black South African origin were studied. Hypertensives were recruited from hospital hypertension clinics in the province of Gauteng and if on treatment, had a 2-4 week washout period before 24-h ambulatory blood pressure assessment Normotensive controls were recruited from the same community.

RESULTS

There was no significant association between either the Arg-Gly16 polymorphism or the Gln-Glu27 polymorphism and hypertension status. Furthermore, in the hypertensives, no significant association was seen between beta2AR genotype at either site and clinical blood pressure, 24-h blood pressure or left ventricular mass. A significant association was seen between Arg16 homozygotes and lower body mass index in hypertensives (P = 0.007) although this was not a primary end point. Interestingly, the Glu27 polymorphism was much rarer in this population (allelic frequency 17%) compared to a Caucasian population.

CONCLUSION

These data suggest that beta2AR polymorphism is not a risk factor for hypertension per se in this defined population. The possibility that the decreased prevalence of Glu27 in black South African populations explains blunted vasodilator responses to isoprenaline requires further study.

Cristobalite in volcanic ash of the soufriere hills volcano, montserrat, british west indies

Crystalline silica (mostly cristobalite) was produced by vapor-phase crystallization and devitrification in the andesite lava dome of the Soufriere Hills volcano, Montserrat. The sub-10-micrometer fraction of ash generated by pyroclastic flows formed by lava dome collapse contains 10 to 24 weight percent crystalline silica, an enrichment of 2 to 5 relative to the magma caused by selective crushing of the groundmass. The sub-10-micrometer fraction of ash generated by explosive eruptions has much lower contents (3 to 6 percent) of crystalline silica. High levels of cristobalite in respirable ash raise concerns about adverse health effects of long-term human exposure to ash from lava dome eruptions.

Highlights of the Digital Imaging Network-Picture Archiving and Communications System Project

The Department of Defense issued its requirements for a Digital imaging Network-Picture Archiving and Communications System (DIN-PACS) in a Request for Proposals to industry in January, 1997. The DIN-PACS shall be an open systems network of digital devices designed for the effective acquisition, transmission, display and management of diagnostic imaging studies. This network is primarily based on two international standards, Digital imaging and Communications in Medicine (DICOM) and Health Level 7 (HL7). The DIN-PACS is required to communicate in a bidirectional manner with the Department of Defense standard hospital information system called the Composite Health Care System (CHCS) through an HL7 compliant interface. The DIN-PACS model and its published specifications stress functionality and performance rather than system architecture to allow industry to propose optimal approaches for implementation. This paper discusses the functional requirements of the DIN-PACS in terms of its internal operations as well as its communication with external systems and components. This is a US government work. There are no restrictions on its use.

Agricultural development paths and pest management: a pragmatic view of sustainability

Historical profiles can be used to portray past pathways of agricultural development, the factors that affected pest status and the responses made by farmers in the form of pest management. Understanding the key factors affecting these historical developments is thought to be crucial for identifying likely future scenarios and associated opportunities and constraints for improving pest management. Evidence for this view is provided by four case studies: brassica pests in the United Kingdom; tsetse fly and trypanosomiasis management in The Gambia; rice pest management in the Lop-Buri area of Thailand; and pest management in dryland cotton in north-east Australia.

Spontaneous immortalization of mouse embryo cells: strain differences and changes in gene expression with particular reference to retroviral gag-pol genes

We have studied the kinetics with which cultures of primary mouse embryo cells pass through the crisis period, escape their terminal differentiation (cellular senescence), and give rise to an immortal cell line. The process is strain-dependent, with cells from the outbred Swiss CD-1 mouse being considerably more adept at forming an immortal 3T3 line than cells from the inbred SWR line; Balb/c cells appeared intermediate in their behavior. The continued presence of the tumor promoter 12-O-tetradecanoylphorbol-13-acetate or the poly(ADPribose)polymerase inhibitor 3-aminobenzamide affected the kinetics but did not seem to alter the outcome. Changes in expression of various genes, including those encoding mitogen-regulated protein (proliferin), endogenous gag-pol retrovirus sequences, insulin-like growth factor II, and a variety of protooncogenes, were monitored during the process of immortalization, and although certain changes were reproducibly characteristic of cells from a given mouse strain passed according to a specific regimen, none of the observed changes were reproducibly characteristic under all conditions of immortalization. In particular, our data indicate the absence of a strict correlation between cellular immortalization and the activation of endogenous gag-pol expression. We conclude from our observations that the establishment of permanent lines from primary mouse embryo cells in serum-containing medium reflects the selection of a variant subpopulation of cells that did not preexist but rather arose in response to the specific culture conditions by a process resembling differentiation. Multiple and complex changes in gene expression occur that are affected by the culture conditions and the strain (genotype) of the mouse.

Differential size distribution of atrial dense granules in spontaneously hypertensive, Wistar-Kyoto and Wistar rats

The differential size distribution of atrial dense granules (ADGs) in spontaneously hypertensive rats (SHR) and two normotensive controls, Wistar and Wistar-Kyoto (WKY) rats, was investigated. The ADGs in SHR were smaller than those in Wistar rats. The ADGs of WKY rats were of intermediate size. It is possible that ADGs are more rapidly secreted in SHR compared with WKY and Wistar rats or that the smaller-diameter granules may contain more atriopeptinogen than the larger granules. The intermediate size of the ADGs in WKY suggests that the WKY variant is morphologically intermediate between the SHR and Wistar strains.

Antisense RNA-induced reduction in murine TIMP levels confers oncogenicity on Swiss 3T3 cells

Mouse 3T3 cell lines capable of constitutively synthesizing an RNA complementary to the messenger RNA encoding TIMP, tissue inhibitor of metalloproteinases, were constructed by transfection with appropriate plasmid constructs. Many of the lines were down-modulated for TIMP messenger RNA levels and secreted less TIMP into the culture medium. In comparison to noninvasive, nontumorigenic controls, these cells not only were invasive in a human amnion invasion assay, but also were tumorigenic and metastatic in athymic mice. These results indicate that TIMP suppresses oncogenicity, at least in immortal murine 3T3 cells.

Independent mechanisms for the chronotropic and inotropic responses in hyperthyroidism

We established a hyperthyroid rat model and compared the hemodynamic responses of the hypertrophied rat heart in vivo and in vitro. Heart rate (557 +/- 26 beats/min), systolic blood pressure (162 +/- 5 mmHg) and dry heart mass (230 +/- 11 mg) in hyperthyroid rats were significantly greater than in control animals (408 +/- 12 beats/min, 140 +/- 5 mmHg and 193 +/- 4 mg respectively). In vitro studies were performed in order to eliminate neurohumoral and peripheral circulatory factors which are present in vivo. In the in vitro "working" heart preparation, there was no significant difference between the heart rates of L-thyroxine-treated (263 +/- 9 beats/min) and control (258 +/- 10 beats/min) animals, implying that the tachycardia of hyperthyroidism is partly mediated by in vivo factors. Consistent with this hypothesis was the observation that the hyperthyroid heart was more sensitive to the chronotropic effects of physiological concentrations of the synthetic catecholamine, isoproterenol (10(-8) M, 10(-7) M) than the control heart. The maximum rate of left ventricular pressure rise (dP/dtmax) was used as an index of myocardial contractility. In vitro values for dP/dtmax were significantly greater in hearts from hyperthyroid rats (5338 +/- 228 mmHg/s) than in control hearts (4583 +/- 158 mmHg/s), suggesting that the increased contractile response of hyperthyroidism is intrinsic to the heart itself. Although persistence of the inotropic response of the hyperthyroid heart in vitro was associated with an increase in heart mass, this factor alone did not account entirely for the enhanced contractility. It appears that intrinsic functional changes also contribute to the inotropic response of the hyperthyroid heart.

Characterization of variable-region genes and shared crossreactive idiotypes of antibodies specific for antigens of various influenza viruses

Several syngeneic monoclonal anti-idiotypic antibodies were obtained against PY206, a monoclonal antibody specific for X-31 (H3N2) influenza virus hemagglutinin. This idiotype was found in the sera of BALB/c mice immunized with various influenza viruses. Adsorption experiments indicated that the PY206 Id was borne by antibodies specific for viral hemagglutinin (HA) and/or neuraminidase (NA). This idiotype was identified on other monoclonal antibodies specific for various influenza HAs (H3 and H1). Study of the variable-region (V) genes of these monoclonal antibodies showed that its expression is independent of variable kappa (VK)21 light-chains and that the heavy-chains of the strongly idiotype-positive hybridomas derive from either the variable heavy (VH) J558 or VH 7183 family. Finally, Western blot analysis demonstrated that PY206 idiotypic determinants are located exclusively on the heavy chain.

Characterization of monoclonal antibodies specific for sequential influenza A/PR/8/34 virus variants

A panel of monoclonal antibodies specific for a corresponding panel of sequentially selected variants of influenza A/PR/8/34 virus has been established. Although the monoclonal antibodies are paratypically distinct, idiotypic relatedness has been observed. Two cross-reactive idiotypes have been defined that are associated with the 7183 and S107 VH gene families, respectively. Three of the four monoclonal antibodies utilize the VK21 group of light chains, and three VH genes belong to the VH7183 family and one to the VH S107 family. Antibodies encoded by genes deriving from the VH7183 family share a cross-reactive idiotype, a marker of the VH region as well as distinct individual idiotopes. These antibodies are produced by different clones using related VH and VK genes.

Characterization of monoclonal antibodies specific for sequential influenza A/PR/8/34 virus variants

A panel of monoclonal antibodies specific for a corresponding panel of sequentially selected variants of influenza A/PR/8/34 virus has been established. Although the monoclonal antibodies are paratypically distinct, idiotypic relatedness has been observed. Two cross-reactive idiotypes have been defined that are associated with the 7183 and S107 VH gene families, respectively. Three of the four monoclonal antibodies utilize the VK21 group of light chains, and three VH genes belong to the VH7183 family and one to the VH S107 family. Antibodies encoded by genes deriving from the VH7183 family share a cross-reactive idiotype, a marker of the VH region as well as distinct individual idiotopes. These antibodies are produced by different clones using related VH and VK genes.

Establishment of an inbred line of mice that express a synergistic immune defect precluding in vitro responses to type 1 and type 2 antigens, B cell mitogens, and a number of T cell-derived helper factors

Introduction of the CBA/N X-linked gene into C3H mice has resulted in the establishment of a new strain of mice that has profound immunologic defects. B cells from these mice show significantly impaired in vitro immune responses to the T cell-independent type 1 antigen trinitrophenyl-Brucella abortus (TNP-BA) as well as markedly reduced proliferative responses to a number of B cell mitogens when compared with the responses of the parental control mice. The in vivo response of such mice to TNP-BA is, however, comparable to that of CBA/N mice. Furthermore, B cells from C3.CBA/N mice are unresponsive to the plaque-forming cell enhancing effects induced by EL4-derived supernatant in the presence of TNP-BA, unlike B cells obtained from CBA/N or C3H/Hen mice whose responsiveness to TNP-BA can be significantly enhanced in the presence of EL4-derived supernatant. The model we have presented to best explain these results suggests that B cells from C3.CBA/N mice can be stimulated only under conditions in which they can interact with carrier-specific T cell help and not under conditions where factor-dependent responses are dominant.

Nutritional effects of field bean (Vicia faba L.) proteinase inhibitors fed to rats

1. Weanling rats were fed on purified-casein diets containing active and inactive (autoclaved) field bean (Vicia faba L.) proteinase inhibitors (PI) at levels of 1.25, 2.5, 5.0 and 10 g/kg. Diets containing raw- and autoclaved-field-bean meal (FBM) were also given. The body-weight gain, protein efficiency ratio (PER); i.e. the ratio of the live weight gain in g/g of protein consumed and apparent nitrogen digestibility were determined 7, 14 and 21 d after the start of the trial. 2. Significant growth depression (P less than 0.001) was observed in rats given diets containing 2.5 g/kg PI (27--35%). In rats fed on raw FBM growth depression was severe after 7 d (57%). 3. Food intake was depressed at PI inclusion levels of 5 g/kg and higher between 14 and 21 d. 4. PER was depressed significanlty (33-44%) in rats given diets containing the active PI at all levels after 7 d. The protein utilization of all casein diets was higher than that of the FBM diets. 5. Apparent N digestibility was depressed in rats fed on diets containing 10 g/kg PI by 9 and 7% at 14 and 21 d respectively. The N digestibility of both raw and heated FBM was similar at approximately 84%. 6. It was concluded that the PI are not the main factors responsible for the growth depression observed when raw FBM is fed to rats.

Effects of dietary proteinase inhibitors from field bean (Vicia faba L.) and field-bean meal on pancreatic function in the rat

1. Male weanling rats were fed casein diets containing 1.25, 2.5, 5.0 and 10 g/kg active or autoclaved proteinase inhibitors (PI) from field bean (Vicia faba L.), and raw- and autoclaved-field-bean meal (FBM) diets. After 7, 14 and 21 d on the diets pancreas weights were measured and pancreas and intestinal trypsin (EC 3.4.4.4) and chymotrypsin (EC 3.4.4.5) assayed.

2. Pancreas weights increased on the raw FBM and active-PI-supplemented diets. Maximum pancreatic hypertrophy measured as the percentage increase above controls was observed after 14 d in rats fed on raw FBM. The same percentage increase in pancreas size compared with appropriate controls was obtained with rats fed casein diets supplemented with 5 g active PI/kg.

3. Pancreas trypsin and chymotrypsin levels decreased with increasing dietary PI level. Similarly, lower pancreas trypsin and chymotrypsin levels were observed in rats given raw FBM.

4. Intestinal trypsin and chymotrypsin increased with increasing dietary PI inclusion level. Although the magnitude of this response decreased with the period of feeding the differences in enzyme levels were still significant even after 21 d.

5. It was concluded that the PI alone in raw-FBM diets could not entirely be responsible for the enlargement of the pancreas and the excess secretion of pancreatic enzymes since in synthetic diets PI levels of five times those in FBM were required to produce responses of similar magnitude.

Compositional changes in developing rape seed (Brassica napus L.)

The growth and composition of siliquas and seeds of oilseed rape was followed over 12 weeks from shortly after anthesis to maturity. Each plant produced 220 siliquas, this number being constant throughout development. Seed numbers per siliqua fell from 19 to 9 by week 5 and declined to 7 at maturity. Hull(1) and seed growth followed a sigmoid pattern, but were not in phase. Seed development could be divided into 3 phases: In Phase 1, seed weight was low and starch and ethanol soluble compounds accounted for 80% DM. Phase 2, seed growth increased and storage oil and proteins were deposited accounting for 40% and 20% DM respectively at the end of this stage. Starch, glucose and fructose were utilized in this process. Phase 3 was largely concerned with the deposition of oil and protein in fixed proportions. Seed weight more than doubled while DM composition remained constant. Sugars were transferred from the hull to the seed to support this growth.The proportion of hull lipids remained constant throughout development until shortly before maturity when MGDG and DGDG fell due to chloroplast breakdown as indicated by chlorophyll disappearance. The FA composition of the hull lipids resembled that of photosynthetic tissue. In the seeds, the neutral lipids increased from 20% of the total lipids in Phase 1 to 93% at maturity. The proportion of structural lipids declined as the storage lipids increased. In Phase 1 the FA composition of the lipid resembled that of photosynthetic tissue (high in C16:0; C18:2; C18:3). In Phase 2, FA typical of storage triglycerides (C20:1; C22:1, appeared, C18:1 transitorily increased, but C18:2 and C18:3 fell dramatically. In Phase 3, the content of C22:1 continued to rise, but the proportions of the other FA remained constant.

The nature of the leucine requirement of the barley mutant Xan-b61

Contrary to previous reports, evidence has been presented which indicates that Xan-b61, a Xantha mutant of barley, does not have an auxotrophic requirement for leucine. It has been shown that this mutant, when grown under appropriate conditions in the absence of leucine, will synthesize leucine and will continue to grow for an extended period of time.