Survey of UK horse owners' knowledge of equine arboviruses and disease vectors

Increased globalisation and climate change have led to concern about the increasing risk of arthropod-borne virus (arbovirus) outbreaks globally. An outbreak of equine arboviral disease in northern Europe could impact significantly on equine welfare, and result in economic losses. Early identification of arboviral disease by horse owners may help limit disease spread. In order to determine what horse owners understand about arboviral diseases of horses and their vectors, the authors undertook an open, cross-sectional online survey of UK horse owners. The questionnaire was distributed using social media and a press release and was active between May and July 2016. There were 466 respondents, of whom 327 completed the survey in full. High proportions of respondents correctly identified photographic images of biting midges (71.2 per cent) and mosquitoes (65.4 per cent), yet few were aware that they transmit equine infectious diseases (31.4 per cent and 35.9 per cent, respectively). Of the total number of respondents, only 7.4 per cent and 16.2 per cent correctly named a disease transmitted by biting midges and mosquitoes, respectively. Only 13.1 per cent and 12.5 per cent of participants identified specific clinical signs of African horse sickness (AHS) and West Nile virus (WNV), respectively. This study demonstrates that in the event of heightened disease risk educational campaigns directed towards horse owners need to be implemented, focussing on disease awareness, clinical signs and effective disease prevention strategies.

The challenges posed by equine arboviruses

Equine populations worldwide are at increasing risk of infection by viruses transmitted by biting arthropods, including mosquitoes, biting midges (Culicoides), sandflies and ticks. These include the flaviviruses (Japanese encephalitis, West Nile and Murray Valley encephalitis), alphaviruses (eastern, western and Venezuelan encephalitis) and the orbiviruses (African horse sickness and equine encephalosis). This review provides an overview of the challenges faced in the surveillance, prevention and control of the major equine arboviruses, particularly in the context of these viruses emerging in new regions of the world.

Potential vectors of equine arboviruses in the UK

There is growing concern about the increasing risk of disease outbreaks caused by arthropod-borne viruses (arboviruses) in both human beings and animals. There are several mosquito-borne viral diseases that cause varying levels of morbidity and mortality in horses and that can have substantial welfare and economic ramifications. While none has been recorded in the UK, vector species for some of these viruses are present, suggesting that UK equines may be at risk. The authors undertook, therefore, the first study of mosquito species on equine premises in the UK. Mosquito magnet traps and red-box traps were used to sample adults, and larvae were collected from water sources such as tyres, buckets, ditches and pools. Several species that are known to be capable of transmitting important equine infectious arboviruses were trapped. The most abundant, with a maximum catch of 173 in 72 hours, was Ochlerotatus detritus, a competent vector of some flaviviruses; the highest densities were found near saltmarsh habitats. The most widespread species, recorded at >75 per cent of sites, was Culiseta annulata. This study demonstrates that potential mosquito vectors of arboviruses, including those known to be capable of infecting horses, are present and may be abundant on equine premises in the UK.

Healthy midlife Canadian women: how bone health is considered in their food choice systems

BACKGROUND

The incidence of osteoporosis is predicted to increase as Western populations age. Diet is considered to be an important modifiable factor in bone health, yet the diets of many women are insufficient in calcium and vitamin D, which comprise two key nutrients for bone health. This focus group study explored ways in which midlife women consider bone health in their personal food choice systems.

METHODS

Data were obtained in six audio-recorded focus groups from a total of 36 women from upper, middle and lower income neighbourhoods. Open and axial coding and thematic analysis revealed shared and unique themes across and within the income groups. Use of member checks, peer debriefing, and independent and team data analysis enhanced rigour in the findings.

RESULTS

All participants were aware of osteoporosis. Most women idealised making simple food decisions and eating for 'holistic' health, but not specifically for bone health. Most midlife women were not motivated to change their diets, few had deliberately increased their intake of calcium and vitamin D through foods and supplements, and few others had simplified their food decisions.

CONCLUSIONS

Midlife women in the present study did not make eating for bone health a priority in their food choice systems. Instead, women wanted to eat for 'holistic' health, and only by implication bone health.

The clearance kinetics of autologous RhD-positive erythrocytes coated ex vivo with novel recombinant and monoclonal anti-D antibodies

Anti-D is given routinely to pregnant RhD-negative women to prevent haemolytic disease of the fetus and newborn. To overcome the potential drawbacks associated with plasma-derived products, monoclonal and recombinant forms of anti-D have been developed. The ability of two such antibodies, BRAD-3/5 monoclonal anti-D IgG (MAD) and rBRAD-3/5 recombinant anti-D IgG (RAD), to clear RhD-positive erythrocytes from the circulation was compared using a dual radiolabelling technique. Six RhD-positive males received autologous erythrocytes radiolabelled with (99m)Tc and (51)Cr and coated ex vivo with MAD and RAD. Blood samples were collected up to 1 h following intravenous injection, and percentage dose of radioactivity in the samples determined. Three different levels of coating were used on three separate occasions. No significant differences between MAD and RAD were observed in the initial clearance rate constant at any dose level. The log[activity]-time clearance plots were curved, showing a reduction in the clearance rate constant with time. This reduction was more marked for RAD than for MAD. The results support a dynamic model for the clearance of antibody-coated erythrocytes that may have wider relevance for the therapeutic use of antibodies.

Growing up: perspectives of children, families and service providers regarding the needs of older children with perinatally-acquired HIV

Children with perinatally-acquired HIV are living into adolescence and adulthood. As this is a relatively new phenomenon, there is a paucity of research highlighting the complex issues that arise for these children. This qualitative case-study examines the needs of a select group of older children (9-16 years old) with perinatally-acquired HIV in the province of British Columbia, Canada through focus groups and interviews conducted with ten HIV-infected children, 11 family members and 11 service providers. The needs of this population are diverse, reflecting its heterogeneity. However, participants consistently highlighted issues of stigma, sexual health and mental health as major areas of current and future concern. Continued support, education and future planning in these areas are necessary for older HIV-infected children as they transition out of childhood.

Integration and individuality in healthy eating: meanings, values, and approaches of childless, dual earner couples

INTRODUCTION AND OBJECTIVES

Although considered to be an important component of food choice, perceptions and practices regarding healthy eating vary between people and change over the life-course. The purpose of this paper is to examine integration and individuality in healthy eating meanings, values, and approaches of individuals in childless, dual earner couples.

MATERIALS AND METHODS

Fourteen participants (from seven couples) were recruited using notices and snowball sampling. Food journals and individual interviews were used to explore the nature of and negotiations between partners' healthy eating values and approaches. Data were analysed through iterative procedures that included coding, thematic analysis and memo writing.

RESULTS

Participants presented individual healthy eating values and approaches based on their own experiences with food over time. Cohabitation resulted in a continuum of healthy eating negotiation outcomes, including congruent values and approaches, congruent values but divergent approaches, and divergent values and approaches. In combination with other salient factors, cohabitation provides an opportunity for improving healthy eating approaches.

DISCUSSION

Cohabitation has the potential to lead to positive changes in healthy eating approaches. Practitioners need to tailor messages for clients' specific needs and encourage change in the direction of the partner with the healthier eating approach.

Canadian dietitians' views and practices regarding obesity and weight management

OBJECTIVE

To provide insight into Canadian dietitians' attitudes and practices regarding obesity and weight management.

DESIGN

Cross-sectional mail survey of a stratified random sample of members of Canadian dietetic associations.

SUBJECTS

A total of 514 dietitians (74% of those surveyed), 350 (69%) of whom actively counselled overweight/obese clients.

MEASUREMENTS

Participants received a questionnaire to assess dietitians' attitudes regarding obesity and overweight, views regarding their role in weight management, counselling practices, and the criteria used to judge success. Demographic variables were collected.

RESULTS

Most dietitians believed that obesity contributes to morbidity and mortality, and that small weight losses produced important health benefits. However, 80% agreed that health indicators other than weight loss should be the focus of obesity management, and 55% specifically recommended that clients not weigh themselves. Instead, weight management was promoted by recommending healthy eating and increased physical activity. Three-quarters agreed that they are the profession best trained to manage obesity but two-thirds believed their time would be better spent preventing rather than managing obesity. Dietitians most valued education received from on-the-job support and mentoring from other dietitians. Participants reported wanting to learn more about motivational and behavioural modification counselling techniques.

CONCLUSIONS

Canadian dietitians follow a lifestyle approach to weight management. Studies are required to formally assess the effectiveness of various aspects of this approach.

Oncologists' and naturopaths' nutrition beliefs and practices

PURPOSE

Despite the widespread use of complementary and alternative therapies by persons with cancer, little is known about how the understandings of complementary and alternative practitioners of these therapies compare with those of conventional physicians. The broad purpose of this research was, thus, to explore the beliefs of physicians and complementary and alternative health practitioners, their use of scientific and other types of evidence, and their counseling practices. The specific issue addressed was the beliefs and practices of oncologists and naturopaths regarding the role of diet in breast cancer prevention and treatment.

DESCRIPTION OF STUDY

A qualitative research design was used, involving in-depth semistructured interviews with 10 oncologists and 11 naturopaths. Interviews were tape-recorded, transcribed verbatim, and analyzed using qualitative methods.

RESULTS

The oncologists believed that there is little evidence of a role for diet in breast cancer prevention and treatment, citing the lack of evidence from randomized controlled trials. They reported that they provide only general advice on healthy eating to patients. The naturopaths believed that diet is strongly implicated in breast cancer development, prevention, and treatment. They justified this belief by using scientific evidence from a variety of types of studies, logic or common sense, and their clinical experiences. Naturopaths reported that they provide patients with specific suggestions for foods to avoid or to emphasize in diets.

CLINICAL IMPLICATIONS

The differences in the advice provided by oncologists and naturopaths are associated with different decision-making or knowledge construction systems. Educating patients about these differences will help patients to make more informed healthcare choices.

Comparison of flow cytometric assays with isotopic assays of (51)chromium-labeled cells for estimation of red cell clearance or survival in vivo

BACKGROUND

A comparison was made between flow cytometric and conventional radioisotopic assays in the determination of the clearance or survival of small volumes of (51)chromium-labeled D+ red cells after injection into volunteers.

STUDY DESIGN AND METHODS

Four clearance studies were performed using 4 mL of autologous D+ cells coated with anti-D at two concentrations (5 or 10 microg anti-D/mL red cells) transfused to two subjects at separate times. Five survival studies were carried out using 5 mL of frozen-thawed D+ cells transfused to five D- subjects with no detectable anti-D. Sequential blood samples were taken for gamma counting and flow cytometry. Several methods were used to stain the transfused red cells, and the data were analyzed by using three flow cytometers.

RESULTS

The determination of red cell clearance or survival by radioactivity measurements gave results consistent with published data. However, none of the flow cytometric assays exhibited the necessary sensitivity or accuracy in quantitation of the rare events to provide reliable data for the calculation of the initial clearance rate, the red cell half-life, or the mean cell lifespan, although rough estimates of red cell clearance were obtained in some subjects. This inability to accurately enumerate rare fluorescence-labeled cells was due mainly to the presence of "background" events, which were a considerable problem in some samples, when the coating level of anti-D was less than 3000 molecules of IgG per cell.

CONCLUSION

Flow cytometry may enable the crude estimation of the percentage of small volumes (<5 mL) of transfused D+ red cells, but in this study it was found that this method was not sufficiently accurate to determine the initial clearance rate, red cell half-life, or mean cell lifespan. If the proportion of transfused cells in the recipient is about 0.2 percent or less, the use of radioisotopes for labeling cells for quantitative in vivo red cell clearance or survival data should remain the method of choice.

Filipino women living in Canada: constructing meanings of body, food, and health

This qualitative study explored the understandings of body size, food and eating, and health held by Filipino women living in Canada. Women (n = 11) aged 19 to 30 years old who were born in the Philippines and living in British Columbia participated in individual interviews where they discussed their beliefs and practices relating to their body, food, and health. Informants' comments reflected contrasting "Canadian" and "Filipino" meanings. Canadian beliefs emphasized the desirability of thinness, "watching" intake of fat, rice, and junk food, and minimizing disease risk. Filipino beliefs valued fatness, "just eating" fat and rice, and maximizing disease resistance. While most informants appeared to have adopted the Canadian values, Filipino beliefs continued to be of some significance in their lives. These findings demonstrate the socially constructed nature of health beliefs and illustrate how members of a minority ethnic group negotiate among conflicting cultural beliefs about body size, food and health.

Lower-fat menu items in restaurants satisfy customers

OBJECTIVE

To evaluate a restaurant-based nutrition program by measuring customer satisfaction with lower-fat menu items and assessing patrons' reactions to the program.

DESIGN AND SETTING

Questionnaires to assess satisfaction with menu items were administered to patrons in eight of the nine restaurants that volunteered to participate in the nutrition program. One patron from each participating restaurant was randomly selected for a semistructured interview about nutrition programming in restaurants.

SUBJECTS

Persons dining in eight participating restaurants over a 1-week period (n = 686).

STATISTICAL ANALYSES PERFORMED

Independent samples t tests were used to compare respondents' satisfaction with lower-fat and regular menu items. Two-way analysis of variance tests were completed using overall satisfaction as the dependent variable and menu-item classification (ie, lower fat or regular) and one of eight other menu item and respondent characteristics as independent variables. Qualitative methods were used to analyze interview transcripts.

RESULTS

Of 1,127 menu items rated for satisfaction, 205 were lower fat, 878 were regular, and 44 were of unknown classification. Customers were significantly more satisfied with lower-fat than with regular menu items (P < .001). Overall satisfaction did not vary by any of the other independent variables. Interview results indicate the importance of restaurant during as an indulgent experience.

CONCLUSIONS

High satisfaction with lower-fat menu items suggests that customers will support restaurant providing such choices. Dietitians can use these findings to encourage restaurateurs to include lower-fat choices on their menus, and to assure clients that their expectations of being indulged are not incompatible with these choices.

A pharmacokinetic/pharmacodynamic model for the action of anti-D immunoglobulin in effecting circulatory clearance of Rh D+ red cells

A dynamic model of the action of anti-D immunoglobulin in effecting clearance of Rh D-positive red cells from the circulation of D-negative subjects is presented. The pharmacokinetics of the redistribution of anti-D between injection site, intravascular and extravascular spaces following either intramuscular or intravenous administration is included, also the reaction of anti-D with D-positive red cells in the intravascular space and subsequent circulatory clearance of antibody-coated cells. Numerical computer modelling methods have been used to obtain solutions of the model, using kinetic rate constants which have been derived from previously published experimental data. Selected solutions are presented, chosen for their relevance to (i) clinical situations in which anti-D is used to prevent Rh D immunization of D-negative subjects and (ii) determination of some of the properties of anti-D antibodies which are important for effecting circulatory clearance of D-positive red cells.

Fingerprinting of glycans as their 2-aminoacridone derivatives by capillary electrophoresis and laser-induced fluorescence

Capillary electrophoresis and laser-induced fluorescence detection have been used to fingerprint the 2-aminoacridone derivatives of complex glycans released from bovine fetuin and human IgG monoclonal antibodies. The utility of this method in distinguishing between N- and O-linked oligosaccharides and in determining the presence of sialic acid residues in glycan mixtures at an early stage of analysis has been demonstrated.

Human Rh D monoclonal antibodies (BRAD-3 and BRAD-5) cause accelerated clearance of Rh D+ red blood cells and suppression of Rh D immunization in Rh D- volunteers

The use of prophylactic anti-D to prevent Rh D immunization in Rh D- women and subsequent hemolytic disease in Rh D+ infants is widespread, but has led to shortages of the anti-D Ig. With the aim of substituting monoclonal anti-D for Rh D prophylaxis, we have compared the abilities of monoclonal and polyclonal anti-D to clear Rh D+ red blood cells (RBCs) infused into Rh D- male volunteers and to suppress Rh D immunization. Two human monoclonal antibodies (MoAbs), BRAD-3 (IgG3) and BRAD-5 (IgG1), produced from stable Epstein-Barr virus-transformed B-lymphoblastoid cell lines, were selected because of their proven in vitro activity in promoting RBC lysis in antibody-dependent cell-mediated cytotoxicity assays. RBC clearance was assessed by intravenous injection of 3 mL of 51chromium-labeled D+ RBCs into 27 volunteers 48 hours after intramuscular injection of monoclonal or polyclonal anti-D. Further 3-mL injections of unlabeled D+ cells were administered at 6 and 9 months to induce immunization. Blood samples were taken throughout the 12-month period of study for the serologic detection of anti-D. The mean half-life (t50%) of RBCs in 7 recipients of 300 micrograms BRAD-5 (5.9 hours) was similar to that in 8 recipients of 500 IU polyclonal anti-D (5.0 hours), whereas D+ cells were cleared more slowly in some of the 8 subjects injected with 300 micrograms BRAD-3 (mean t50% 12.7 hours) and in 1 individual administered 100 micrograms BRAD-3 (t50% 41.0 hours). The rate of RBC clearance in both groups administered 300 micrograms monoclonal anti-D correlated with the amount of antibody bound per cell, determined by flow cytometry. There was no evidence of primary immunization having occurred in any subject after 6 months of follow-up. Five of 24 subjects produced anti-D after one or two further injections of RBCs, confirming that they were responders who had been protected by the monoclonal or polyclonal anti-D administered initially. Four of these responders were recipients of monoclonal anti-D (3 BRAD-3, 1 BRAD-5). One individual who received BRAD-5 produced accelerated clearance of D+ RBCs at the third unprotected RBC challenge but did not seroconvert. This study shows that the human MoAbs BRAD-3 and BRAD-5 can prevent Rh D immunization, and indicates that they may be suitable replacements for the polyclonal anti-D presently used in prophylaxis of Rh D hemolytic disease of the newborn.(ABSTRACT TRUNCATED AT 400 WORDS)

Clearance of Rh D-positive red cells with monoclonal anti-D

Two human monoclonal antibodies, one IgG3 and one IgG1, with anti-Rh D specificity, were tested for their ability to clear red cells. Samples of red cells from 12 D-positive subjects were sensitised in vitro with various amounts of antibody, the number of antibody molecules bound to the cells was estimated, and the cells were reinjected into the donor's circulation. Both antibodies mediated clearance but substantially fewer IgG3 than IgG1 antibody molecules were required to produce a given rate of clearance. The IgG3 antibody was slightly more effective than polyclonal anti-D, as judged by comparison with previously published results. Since there is believed to be an association between the rate of red cell clearance by anti-D and the ability of the antibody to suppress D immunisation, the IgG3 monoclonal antibody may prove suitable for the immunoprophylaxis of Rh D haemolytic disease.

Dietary guidelines for prevention of cancer: are they justified?

Although dietary guidelines for reduction of cancer risk have been issued and well publicized, there is still controversy within the scientific community about whether such guidelines are appropriate. Given that the scientific evidence of a causal role for diet in carcinogenesis is suggestive but not conclusive, is it more responsible to promulgate guidelines that might be ineffective or to delay communicating findings to the public until all the evidence is in-a process that could take decades? Because the public is already familiar with guidelines intended to minimize the risk of cancer, how should they be promoted by health professionals given the strength of the evidence on which they are based?

Effect of biosynthetic human growth hormone on insulin action in individual tissues of the rat in vivo

Excessive endogenous production or exogenous administration of human growth hormone (hGH) causes insulin resistance at both the hepatic and extrahepatic levels. However, which extrahepatic tissues are involved have not been defined. We have examined the diabetogenic action of authentic biosynthetic hGH on whole body glucose disposal, hepatic glucose output, and glucose metabolism in individual peripheral tissues. The use of a highly purified preparation of the hormone allowed us to examine the isolated effects of 22K hGH. The euglycemic hyperinsulinemic (approximately 100 mU/L) clamp plus 3H-2-deoxyglucose technique was used to quantitate the effects of hGH on insulin action in vivo. Administration of biosynthetic hGH at a dose of 10 IU/kg/24 h for 48 hours in male Wistar rats (approximately 340 g) produced a highly significant decrease in the steady state clamp glucose infusion rate (GIR) when compared with controls (8.1 +/- 0.6 v 18.7 +/- 0.7 mg/kg/min, P less than .001), reduced insulin-mediated suppression of hepatic glucose output (Ra) (3.9 +/- 0.6 v 0.7 +/- 0.3 mg/kg/min, P less than .05) and a decreased clamp glucose disposal rate (Rd) (12.0 +/- 0.4 v 18.10 +/- 1.1 mg/kg/min, P less than .001). There was a significant decrease in insulin-mediated glucose uptake as indicated by tissue accumulation of [3H]-2-deoxyglucose phosphorylation in diaphragm and hindlimb muscles. Insulin action was more substantially reduced in muscles (approximately 50%) than in adipose tissues (approximately 20%). These studies confirm that the diabetogenic action of hGH in the rat is due to a combination of inhibition of insulin suppression of hepatic glucose output and inhibition of the uptake and subsequent utilization of glucose in skeletal muscles.

The response to treatment with pituitary growth hormone: the New Zealand experience

Ninety-four growth hormone deficient New Zealand children were treated with thrice weekly intramuscular injections of human pituitary growth hormone (GH) from 1979 to 1985 and the results from 43 children were analysed in detail. Their height velocity was mean (SD) 4.0 (1.9) cm/yr immediately prior to treatment and 8.5 (3.1) cm/yr in the first year of treatment. In each of the first three years of treatment the height velocity was significantly increased (p less than 0.001), but there was a significant decline in height velocity between the first and second, and second and third years. Nevertheless each year of treatment gave a highly significant gain in relative height. Bone age did not advance more rapidly than chronological age during the first two years of treatment, but did so subsequently. The response to GH, as assessed by the increase in relative height, was negatively correlated with the relative height at the start of treatment and with the maximum pretreatment plasma GH response to insulin hypoglycaemia. There was no correlation with pretreatment relative height velocity or aetiology of GH deficiency. Height velocity improved in five of 14 children treated with thyroxine after starting GH. Discontinuation of GH for one year in 34 children resulted in a highly significant reduction in growth rate from 7.5 (2.4) cm/yr to 2.5 (2.0) cm/yr, however four prepubertal children continued to grow at a rate exceeding 4 cm/yr.

Human growth hormone binds to lactogenic receptors in bovine, ovine and rat adrenals

The distribution of 125I radioactivity in the liver, kidneys, adrenals and serum of male rats was measured 10 minutes after an intravenous bolus of 125I-labelled human growth hormone (hGH) was administered in the presence or absence of a large excess of ovine growth hormone or ovine prolactin. The hGH binding sites in the adrenals had displacement properties characteristic of lactogenic receptors, whereas those in the liver had displacement properties characteristic of somatogenic receptors. Bovine and ovine adrenal microsomal membrane fractions contained high affinity (Ka = 1.4-3.3 nM-1) binding sites for hGH which showed ligand specificity typical of lactogenic receptors. It is concluded that the hGH binding site in the adrenal gland is a classical lactogenic receptor and that this tissue is a convenient and rich (42.6 +/- 6.4 fmol hGH specifically bound/mg protein) source of receptor suitable for further characterization.

Reporting therapeutic discourse in a therapeutic community

Research in nurses' communications has concentrated on nurse to patient interactions. Those few studies which focus on nurse to nurse communications seem to be generated by a pragmatic and normative concern with effective information sharing. In this paper, which describes one aspect of a larger case study of a hospital-based therapeutic community, the description and analysis of nurses' reports flows not from a normative model of professional practice, but rather an exploration of how professional practice is articulated as discourse in nurses' written accounts. Foucault's ideas about therapeutic discourse inform the theoretical framework of the research. Ethnomethodological concerns with the importance of documentary analysis provide the methodological rationale for examining nurses' 24-hour report documents, as official discourse, reflecting therapeutic practice in this setting. A content analysis of nurses' reports, collected over a period of 4 months, demonstrated the importance of domesticity and ordinary everyday activities in nurses' accounts of hospital life. Disruption to the 'life as usual' domesticity in the community seemed to be associated with admission to and discharge from the hospital when interpersonal and interactional changes between patients occur. It is suggested that nurses in general hospital wards and more orthodox psychiatric settings might usefully consider the impact of admissions and discharges on the group of patients they manage, and make this a discursive focus of their work.

Determination of the effect of acetylation of specific lysine residues in human growth hormone on its affinity for somatogenic receptors by an affinity selection technique

A technique is described to study the effect of acetylation of individual lysine residues in peptide hormones on the affinity for their receptors, and is illustrated for the case of human growth hormone (hGH) binding to somatogenic receptors. The hGH was partially acetylated with high specific activity [3H]-acetic anhydride and the product ([3H]-Ac-hGH) was incubated with solubilised affinity-purified somatogenic receptors (from male rat liver) in the presence and absence of excess unlabelled hGH. The receptor-bound and unbound labelled hormone were separated by gel filtration and subjected to HPLC tryptic peptide mapping after the addition of cold carrier Ac-hGH. Peaks of [3H] radioactivity were assigned to peptides corresponding to the acetylation of specific lysine residues in the hGH sequence by amino acid analysis and sequencing. Comparison of the relative intensities of corresponding [3H] peaks in the peptide maps of added receptor, bound and unbound [3H]-Ac-hGH, enabled the relative receptor-binding potencies of different acetylated hGH species to be determined. Acetylation of lysine 168 or 172 in hGH greatly decreases its receptor-binding affinity, acetylation of lysine 115 probably causes a minor decrease, whereas acetylation of lysines 38, 70, and the N-terminal amino group have no appreciable effect. Acetylation of lysine 140 causes a significant increase in receptor-binding affinity.

Stimulation of brain Na,K-ATPase by norepinephrine but not taurine

The effect of taurine on rat and hamster brain Na,K-ATPase was examined and compared to norepinephrine (NE) stimulation of the enzyme. Although NE stimulation of microsomal Na,K-ATPase was observed in the presence of the cell cytosolic fraction, taurine was without effect in the presence and absence of this fraction. Taurine also failed to modulate pubescent and mature hamster brain Na,K-ATPase. Presence or absence of ion chelators did not change taurine's effect. These results are discussed in relation to previous reports of taurine and catecholamine stimulation of Na,K-ATPase.

The amino acid sequence of Emu osteocalcin: gas phase sequencing of Gla-containing proteins

Osteocalcin (OC), the major gamma carboxyglutamic acid (Gla)-containing protein of vertebrate bone, has been isolated from bones of the emu (Dromaius novaehollandae) and the primary structure determined by a combination of gas phase N-terminal sequencing of the intact molecule and a proteolytic fragment, and carboxypeptidase Y C-terminal sequencing. Gla residues were located by counting tritium radioactivity in fractions from the N-terminal sequencing of the tritiated/thermally decarboxylated molecule. Emu OC consists of 48 amino acid residues containing 3 Gla residues, and a single disulphide bond. The C-terminal 29 residues are identical to those of the human and sheep OC sequences. Alignment of the N-terminal sequence against those of other OCs reveals greater sequence homology with chicken OC than with mammalian OCs.

Methionine oxidation in human growth hormone and human chorionic somatomammotropin. Effects on receptor binding and biological activities

The oxidation of the methionine residues of human growth hormone (hGH) and human chorionic somatomammotropin (hCS) to methionine sulfoxide by hydrogen peroxide has been studied. The kinetics of oxidation of individual methionine residues has been measured by reverse-phase high pressure liquid chromatography tryptic peptide mapping. Met-170 is completely resistant to oxidation in both hormones. The other 3 methionine residues in hCS (Met-64, Met-96, and Met-179) have markedly different reaction rates. Oxidation of the methionine residues does not appear to cause gross conformational changes in either hGH or hCS, as judged by CD and 1H NMR spectroscopy. Oxidation of Met-14 and Met-125 in hGH has little effect on affinity of the hormone for lactogenic receptors or on its potency in the Nb2 rat lymphoma in vitro bioassay for lactogenic hormones. The oxidation of Met-64 and/or Met-179 in hCS reduces profoundly both its affinity for lactogenic receptors and its in vitro biological potency. It is inferred by induction that residues 64 and/or 179 are critical for the binding of both hGH and hCS to lactogenic receptors and the expression of lactogenic biological activity.

Low serum osteocalcin levels in glucocorticoid-treated asthmatics

Serum osteocalcin (OC) levels were measured in 19 asthmatic patients receiving long term glucocorticoid therapy and in age- and sex-matched asthmatic patients not receiving this treatment. In the glucocorticoid-treated patients, the mean OC level was approximately 50% less than that in the control group (P less than 0.001), and there was a direct correlation between serum OC and 1,25-dihydroxyvitamin D [1,25-(OH)2D; r = 0.71; P less than 0.001]. Multiple regression analysis in a total of 39 glucocorticoid-treated patients indicated that OC correlated directly to 1,25-(OH)2D and inversely to glucocorticoid dose. There was no correlation between OC and 1,25-(OH)2D in the control group and no significant difference in mean serum 1,25-(OH)2D between the steroid-treated asthmatic patients and the asthmatic control patients. The effect of a 4-day course of oral 1,25-(OH)2D on serum OC was studied in six patients with glucocorticoid excess and six normal subjects. There was a similar percent increase in OC levels in both groups, though the basal concentrations and absolute increases were substantially less in the steroid-treated group. It is likely that the depression of serum OC in glucocorticoid-treated patients results from the reduction in the rate of bone formation induced by these hormones.

Immunochemical detection and characterisation of osteocalcin from moa bone

Osteocalcin (the 6,000 dalton Mr gamma-carboxyglutamate-containing protein of bone) has been detected in acid extracts of bones of the extinct class of New Zealand ratite birds, the moas, using a radioimmunoassay for sheep osteocalcin. The immunoreactive osteocalcin of the extracts of two of these bones (the fibulae from two specimens of Pachyornis elephantopus found in South Island swamps) has been fractionated by gel filtration chromatography and reversed-phase high performance liquid chromatography, and behaves in a manner characteristic of osteocalcin from modern bones. Carbon-14 dating of bones and gizzard contents found in association with these specimens indicates approximate ages of 3,600 and 7,400 years respectively.

The amino acid sequences of goat, pig and wallaby osteocalcins

The amino acid sequences of osteocalcins from cortical long bones of goat, pig and wallaby have been determined by manual microsequencing methods. The location of the gamma-carboxyglutamic acid residues were identified by N-terminal degradation of peptides in which these residues had been tritium-labelled in the gamma-H position and subsequently thermally decarboxylated to glutamic acid residues. Glutamic-17 is not gamma-carboxylated in wallaby osteocalcin, unlike other osteocalcins so far sequenced (except human). This may be related to sequence changes in the flanking residues. Proline-9 is fully hydroxylated in wallaby osteocalcin, despite the sequence substitution Ala-8----Phe-8.

A proton-nuclear-magnetic-resonance study of human somatotropin (growth hormone). Assignment and properties of the histidine residues

The 1H-n.m.r. spectra of human somatotropin (growth hormone) show perturbed peaks from individual aromatic and aliphatic apolar residues, characteristic of a specifically folded globular structure. The imidazole C-2-H resonances of the histidine residues (at positions 18, 21 and 151 in the somatotropin sequence) were individually resolved, and their titration behaviour in the pH range 1.2-11.5 was investigated. The imidazole C-2-H resonance of histidine-151 is assigned, by comparison of its titration behaviour in human somatotropin and desamido-somatotropin (Asn-152 leads to Asp-152). The C-2-H resonances of all three histidine residues are assigned, by comparison of their relative deuterium-exchange rates (determined by n.m.r.) and the relative tritium-exchange rates of the histidine residues (determined by tryptic digestion of tritiated human somatotropin and reversed-phase high-pressure liquid-chromatographic separation of the histidine-containing tryptic peptides). There is evidence that histidine-18 forms an ion-pair bond with a glutamic acid or aspartic acid residue. The globular structure does not appear to change from pH3 to 11.5, though there is evidence for an unfolding of a region of the structure (involving histidine-21 and a tyrosine residue) below pH3.

Ritual and rational action in hospitals

Menzies argues that nursing hierarchies and ritual practices protect nurses from the anxieties provoked by encountering human suffering. This proposition is examined with particular reference to ritual practices in nursing. It is argued that Menzies studied nurses in isolation from the societal and subcultural norms and values which direct hospital activity. Her psychodynamic model is contrasted with a sociological model of human conduct and action. The characteristics of ritual and rational action, and the difference between non-rational and irrational rituals, is explored. The findings of three 5-month periods of participant observation are presented as illustrative case material to support the authors view, that ritual procedures are not only defence mechanisms against anxiety, but social acts which generate and convey meaning. Ritual practices described in this analysis include rituals surrounding birth, death, status and power. It is concluded that if nurses wish to change or alter ritual nursing practices in hospital it is necessary to understand their social as well as their psychological meaning.

The isolation of human pituitary hormones from frozen glands

An integrated scheme for the extraction and purification of human pituitary hormones from frozen glands has been developed. The method yields 6.3 mg/gland of monomeric pyrogen-free GH in a single fraction, with a potency of 2.5-3.1 IU/mg, as estimated by bioassay, radioreceptor assay, and RIA, with a further 0.6 mg/gland recovered from side fractions. A glycoprotein fraction yields 200 IU FSH, 500 IU LH, and 0.2 IU TSH per gland, as estimated by RIA. Additional hormones purified from side fractions include PRL, lipotropins, and the 20,000 molecular weight variant of human GH.

The 20,000 molecular weight variant of human growth hormone. Preparation and some physical and chemical properties

Extracts of frozen human pituitary glands contain, in addition to normal growth hormone (hGH (Mr = 22,005), a variant of lower molecular weight (approximately 20,000) (Singh, R. N. P., Seavey, B. K. and Lewis, U. J. (1974) Endocrinol. Res. Commun. 1, 449-464). This material, designated 20K hGH, occurs in various forms with the majority present as a heterologous dimer of Mr = 20,000 hGH and hGH. The purification scheme for obtaining the variant from these fractions is described. Analysis of Mr = 20,000 hGH in the sequenator has confirmed that residues 32-46 of hGH are absent in Mr = 20,000 hGH. The structures of hGH and Mr = 20,000 hGH have been compared by 1H nuclear magnetic resonance spectroscopy, circular dichroism, spectrophotometric titration, and nitration of the tyrosine residues by tetranitromethane. The results indicate that the folding of the polypeptide chain of the two proteins is similar but not identical.

The conformation of histone H5 bound to DNA. Maintenance of the globular structure after binding

Trypsin digestion is used to investigate the conformation of histone H5 when bound to DNA. A central region of H5 comprising residues (22--100) is found to be resistant to digestion and it is concluded that this region is compacted whilst the remaining N- and C-terminal regions are more extended. Since this is the same result found previously for the free solution conformation of histone H5 it follows that a 3-domain structure is preserved on DNA binding. The binding of H5 and the central region (22--100) to DNA is also studied using proton magnetic resonance (270 MHz) and a precipitation approach. It is concluded that all 3 domains of H5 bind to DNA at low ionic strengths. The central domain (residues 22--100) is released at 0.3--0.4 M NaCl, but 0.7 M NaCl is required to release the N- and C-terminal regions. Comparison is made of H5 binding to DNA with that of the related histone H1.

A nuclear-magnetic-resonance study of the globular structure of the H5 histone

The structure of the globular region of the chicken erythrocyte H5 histone has been studied by 270-MHz proton magnetic resonance. The aromatic resonances have been partially assigned by a combination of selective deuteration and iodination with the nuclear magnetic resonance spectroscopy. Detailed titration studies have revealed interactions between residues in the structure. A technique involving the measurement of small nuclear Overhauser effects has enabled the assignment of the aromatic residues causing the perturbation of the ring-current-shifted methyl resonances occurring in the upfield region of the spectrum. Spin-decoupling experiments on these peaks has enabled a partial assignment of shifted methyl resonances. The results support the notion that the histone H5 globular structure is different from that of the homologous histone H1 molecule.

The conformation of histone H5. Isolation and characterisation of the globular segment

Treatment of chicken erythrocyte histone H5 with trypsin in a high-ionic-strength medium results in very rapid initial digestion and the formation of a 'limiting' resistant product peptide. Under these solution conditions the H5 molecule is maximally folded by spectroscopic criteria and it is concluded that the resistant peptide, GH5, represents a globular folded region of the molecule whilst the rapidly digested parts are disordered. The peptide GH5 is shown to comprise the sequence 22-100. In support of this conclusion it is shown that whilst intact histone H5 is hydrodynamically far from being a compact globular shape, peptide GH5 is approximately spherical by hydrodynamic and scattering criteria. Further more, peptide GH5 retains all the alpha-helical structure of intact H5 (circular dichroism) and appears to also maintain all the tertiary structure (nuclear magnetic resonance). It follows that in solution at high ionic strength, histone H5 consists of three domains: an N-terminal disordered region 1-21, a compact globular central domain 22-100 and a long disordered C-terminal chain 101-185. Structural parallels are drawn with the three-domain structure of the histone H1 molecule.

Studies on the role and mode of operation of the very-lysine-rich histone H1 in eukaryote chromatin. The three structural regions of the histone H1 molecule

Limited digestion with trypsin of both calf thymus H1 histone and the fragment 1--120 of the H1 molecule has resulted in the isolation of the fragment 35--120. This fragment assumes a globular structure under physiological conditions of pH and ionic strength. The variable N-terminal portion of the molecule, up to residue 34, is not required for the formation of the H1 globular structure. Proton nuclear magnetic resonance (NMR) and ultracentrifugation studies show that the H1 histone molecule consists of three distinct structural domains under structuring conditions: a random coil 'nose' consisting of 35 to 40 residues from the N-terminal end; a globular 'head' involving the next approximately 80 residues; and a random-coil 'tail' of the remainder of the molecule.

Studies on the role and mode of operation of the very-lysine-rich histone H1 in eukaryote chromatin. The isolation of the globular and non-globular regions of the histone H1 molecule

Digestion of calf thymus H1 histone with thrombin cleaves the molecule at the sequence -(Pro)-Lys-Lys-Ala-, corresponding to a point approximately 122 residues from the N-terminus (about 56% along the molecule). The N-terminal fragment is shown by proton nuclear magnetic resonance (NMR) to possess the globular structure of the intact histome H1 molecule, whereas the C-terminal fragment appears to possess little or no structure. The N-terminal fragment separates into two peaks on an ion-exchange column, one of which is shown to originate from a single subfraction of calf thymus histone H1 and the other to originate from the other subfractions, by detailed comparison of the NMR spectra. It thus seems that the structure of the H1 histone in solution under physiological conditions consists of a globular head with a highly basic random coil tail. It is suggested that the globular head has a specific binding site on the subunit structure of the chromosome.

Studies on the role and mode of operation of the very-lysine-rich histone H1 (F1) in eukaryote chromatin. The properties of the N-terminal and C-terminal halves of histone H1

Restricted chymotrypsin digestion of calf thymus H1 histone gives two fragments, residues 1--106 and 107--C-terminal. These were studied by proton magnetic resonance and circular dichroism. The N-terminal fragment exhibited some salt-induced structure in aqueous solution, but this did not parallel the globular structure of the intact H1 molecule. Comparison of circular dichroism results with helix predictions for this portion of the molecule suggests that the secondary structure may be the same in this fragment as it is in the corresponding region of the whole molecule. The C-terminal fragments show very little salt-induced structure. The N-terminal fragments binds to DNA very weakly, but the C-terminal fragment binds as strongly as the whole molecule. In the C-terminal fragment, about one quarter of the lysine residues are not bound to the DNA in water, but initial increase of salt concentration causes them to become bound. This increasing binding occurs under the same ionic conditions that cause chromatin condensation and condensation of H1 - DNA complexes, and it is suggested that there may be a connection between these phenomena.

Studies on the role and mode of operation of the very-lysine-rich histone H1 (F1) in eukaryote chromatin. The conformation of histone H1

Proton magnetic resonance, circular dichroism and other studies of whole and cleaved calf thymus histone H1 (formerly F1) reveal the presence of specific folded structures in the region approximately from residue 40--115. Ionic, hydrogen-bond and hydrophobic interactions all appear to contribute to the stability of the structure, which is predicted to contain alpha-helices in regions 42--55 and 58--75. No evidence was found for beta-structures, either inter or intramolecular, or for any structure formation outside the region 40--115. At 18 degrees C and a protein concentration of 2 mM the first-order exchange rate between random-coil and structured forms is slower than 80 s-1; at 40 degrees C the exchange rate is faster than 330 s-1.

a model for collagen hydration

A detailed proton nuclear magnetic resonance study has been made of the influence of temperature and water content upon the nature of water adsorbed on collagen fibres. A refinement of a previously reported analysis of time-averaged tensor properties of the water molecule with respect to the fibre axis supports the previous conclusion that the water molecules form hydrogen-bonded chains around the collagen molecules. The experimental evidence strongly indicates that there is an inner hydration layer consisting of about 24 % water per weight of dry collagen, which is highly ordered, surrounded by a disordered outer layer of water at high-water contents. Exchange of water molecules between the inner and outer hydration layers takes place at a rapid rate. Dynamic aspects of the hydration structure are discussed, and it is suggested that the inner hydration layer imparts an appreciable degree of kinetic stability to the native conformation of the collagen molecule.

The hydration structure of collagen

The partially oriented state of water absorbed on bovine achilles tendon has been confirmed by nuclear magnetic resonance methods. The average orientation is described in terms of three parameters which have been determined uniquely by using a novel combination of magnetic resonance and dielectric measurements. These parameters allow a series of possible effective orientation axes of the water molecule to be calculated and the water is thought of as spending a part of its time in one of the oriented states represented by these axes, which therefore represents the hydration structure of collagen, and the rest as a part of an isotropic system. The oriented states are discussed in terms of postulated hydration structures. It is concluded that the water exists in continuous chains which may be either fully extended, in a helical configuration of high pitch or in some other periodic conformation.

The Angular Distribution of Atoms Sputtered from Monocrystalline Gold

The angular distribution of atoms sputtered from metal single crystals has been used to study atom ejection processes. By analysing this distribution into the sum of a Gaussian and a cosine contribution it is shown that the isotropic background can be removed and considerably improved agreement obtained between theory and experiment. This is applied to the temperature variation of the width of Wehner spots. New experimental results are presented for gold sputtered by 10 keY argon ions over a wide range of temperatures.