bluuebunny/crossref_metadata_2025 huggingface dataset:
Are species differences in maternal effects arising from maternal care adaptive?
Authors: Benowitz K. M. , Moody K. J. , Moore A. J.
Published: December 2014

Parental care benefits offspring through maternal effects influencing their development, growth and survival. However, although parental care in general is likely the result of adaptive evolution, it does not follow that specific differences in the maternal effects that arise from care are also adaptive. Here, we used an interspecific cross‐fostering design in the burying beetle speciesNicrophorus orbicollisandN. vespilloides, both of which have elaborate parental care involving direct feeding of regurgitated food to offspring, to test whether maternal effects are optimized within a species and therefore adaptive. Using a full‐factorial design, we first demonstrated thatN. orbicolliscare for offspring longer regardless of recipient species. We then examined offspring development and mass in offspring reared by hetero‐ or conspecific parents. As expected, there were species‐specific direct effects independent of the maternal effects, asN. orbicollislarvae were larger and took longer to develop thanN. vespilloidesregardless of caregiver. We also found significant differences in maternal effects:N. vespilloidesmaternal care caused more rapid development of offspring of either species. Contrary to expectations if maternal effects were species‐specific, there were no significant interactions between caretaker and recipient species for either development time or mass, suggesting that these maternal effects are general rather than optimized within species. We suggest that rather than coadaptation between parents and offspring performance, the species differences in maternal effects may be correlated with direct effects, and that their evolution is driven by selection on those direct effects.
Transcription factors Sox10 and Sox2 functionally interact with positive transcription elongation factor b in Schwann cells
Authors: Arter Juliane , Wegner Michael
Published: December 2014

Sox proteins are mechanistically versatile regulators with established relevance to different developmental processes and crucial impact on chromatin structure, DNA conformation, and transcriptional initiation. Here, we show that Sox2 and Sox10, two Sox proteins important for Schwann cell development, also have the capability to activate transcriptional elongation in a Schwann cell line by recruiting the positive transcription elongation factor b. Recruitment is mediated by physical interaction between the carboxyterminal transactivation domains of the two Sox proteins and the Cyclin T1 subunit of positive transcription elongation factor b, with interaction interfaces for the two Sox proteins being mapped to adjacent regions of the central part of Cyclin T1. Supporting the relevance of this interaction to Schwann cell development, transcription of myelin genes appears regulated at the level of elongation. Our results thus add a new facet to the activity of Sox proteins and expand the functional repertoire of this important group of developmental regulators.

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Sox transcription factors are important regulators of nervous system development. While they are known to regulate transcription by recruiting and stabilizing the RNA polymerase II preinitiation complex directly or with help of the Mediator complex, this study provides evidence that Sox10 and Sox2 additionally influence transcription in glial cells at the elongation stage by recruiting P‐TEFb. Cdk9, cyclin‐dependent kinase 9; P‐TEFb, positive transcription elongation factor b; Pol II, RNA polymerase II; Sox, Sox2 or Sox10 protein.
Gradation of the Stress Response in Rainbow Trout Exposed to Stressors of Different Severity: The Role of Brain Serotonergic and Dopaminergic Systems
Authors: Gesto M. , López‐Patiño M. A. , Hernández J. , Soengas J. L. , Míguez J. M.
Published: December 2014

After an intense acute stressor, fish develop a metabolic and behavioural response that usually lasts for several hours. Brain monoaminergic systems, particularly the serotonergic system, appear to play a key role in the central regulation of the stress response. However, the influence of stressor severity on brain monoaminergic systems and on the induced stress responses is yet poorly understood. We hypothesise that serotonergic system could have a direct role in the integration of sensory information during stressor exposure and in the organisation of the subsequent integrated stress response. According to our hypothesis, a low stressor intensity would induce a low response of brain serotonergic system and therefore stress responses of low magnitude and duration. To test this hypothesis, we exposed fish to handling disturbance for 5 s, 15 s or 3 min. We sampled fish at 0 (controls), 3, 15, 45 and 240 min after the start of the stress protocol. Brain levels of serotonin, dopamine and their respective main oxidative metabolites were quantified, along with plasma levels of stress markers (catecholamines, cortisol, glucose and lactate). Regarding stress markers, the 5‐s and 15‐s stress protocols induced similar and relatively low elevations in all parameters assessed. As expected, the 3‐min protocol induced responses of a higher intensity and duration in all plasma parameters. Interestingly, the alterations of brain monoaminergic systems did not follow the same trend. The three stress protocols induced increases in the serotonergic activity in all brain regions analysed (hypothalamus, telencephalon and medulla oblongata), independently of the duration of the handling disturbance, whereas the effects on the dopaminergic system were minor and brain region‐dependent. These data suggest that the brain serotonergic system, although likely involved in the recognition of the stressor stimuli, is not the only actor determining the magnitude and duration of the acute stress response in trout.
Strategic Action Fields inUSHigher Education: The 1939Mercer University Heresy Trial
Authors: Taylor Barrett J.
Published: December 2014

This paper usesFligstein andMcAdam's (2012, 2011) theory of the strategic action field, or “SAF,” to highlight the ways in which individuals can act within cultural and material constraints to shape social processes. It applies these concepts to theMercer University heresy trial of 1939, in which a group of students backed by fundamentalists from the conservative Protestant movement accused members of the University's faculty of unbelief. By understanding the organization, the social movement, and the higher education industry as “SAFs,” the theory explains how the trial reached its unusual outcome, and suggests implications for broader understandings of organizational change.
Nurses' experiences of restraint and seclusion use in short‐stay acute old age psychiatry inpatient units: a qualitative study
Authors: Muir‐Cochrane E. C. , Baird J. , McCann T. V.
Published: December 2014

Accessible summary

While the decision to use restraint and seclusion was not taken lightly, nurse participants felt that there were no effective alternatives to the use of these measures.

Adverse interpersonal, physical and practice environments contributed to the onset of aggression in old age psychiatry inpatient settings.

Policies to reduce or eliminate the use of restraint and seclusion need to take account of wide‐ranging strategies to deal with aggression, including the provision of appropriate education and support and addressing ethical and workplace cultural issues associated with these practices.

Restraint and seclusion are often ineffective and can affect patients adversely. In this study, we explored nurses' experiences of restraint and seclusion in short‐stay acute old age psychiatry inpatient units and how these experiences underpin resistance to eliminating these practices. Qualitative interviews were conducted with nurses in three old age psychiatry units in Melbourne, Australia. The results provide one overarching theme, lack of accessible alternatives to restraint and seclusion, indicating that nurses believe there are no effective, accessible alternatives to these practices. Three related themes contribute to this perception. First, an adverse interpersonal environment contributes to restraint and seclusion, which relates to undesirable consequences of poor staff‐to‐patient relationships. Second, an unfavourable physical environment contributes to aggression and restraint and seclusion use. Third, the practice environment influences the adoption of restraint and seclusion. The findings contribute to the limited evidence about nurses' experiences of these practices in short‐stay old age psychiatry, and how account needs to be taken of these experiences and contextual influences when introducing measures to address these practices. Policies addressing these measures need to be accompanied by wide‐ranging initiatives to deal with aggression, including providing appropriate education and support and addressing ethical and workplace cultural issues surrounding these practices.
Nursing students’ post‐traumatic growth, emotional intelligence and psychological resilience
Authors: Li Y. , Cao F. , Cao D. , Liu J.
Published: December 2014

Accessible summary

Nursing students in the present sample who have experienced childhood adversity have a certain level of post‐traumatic growth.

If introduced into nursing curricula, emotional intelligence interventions may increase emotional coping resources and enhance social skills for nurses, which may benefit their long‐term occupational health.

As researchers consider personal resilience a strategy for responding to workplace adversity in nurses, resilience building should be incorporated into nursing education.

This is a preliminary study that may guide future investigations of the curvilinear relationship rather than linear relationship between post‐traumatic growth and positive factors in the special sample of nursing students.

Resilience, emotional intelligence and post‐traumatic growth may benefit nursing students’ careers and personal well‐being in clinical work. Developing both their emotional intelligence and resilience may assist their individual post‐traumatic growth and enhance their ability to cope with clinical stress. To investigate the relationships among post‐traumatic growth, emotional intelligence and psychological resilience in vocational school nursing students who have experienced childhood adversities, a cross‐sectional research design with anonymous questionnaires was conducted and self‐report data were analysed. The Childhood Adversities Checklist (Chinese version), Posttraumatic Growth Inventory, Emotional Intelligence Scale and the 10‐item Connor–Davidson Resilience Scale were used. Survey data were collected from 202 Chinese vocational school nursing students during 2011. Post‐traumatic growth was associated with emotional intelligence and psychological resilience. Results indicated a curvilinear relationship between emotional intelligence and post‐traumatic growth, and between psychological resilience and post‐traumatic growth. Moderate‐level emotional intelligence and psychological resilience were most associated with the greatest levels of growth. The results imply that moderate resilience and emotional intelligence can help nursing students cope with adversity in their future clinical work. This study first provided preliminary data suggesting the curvilinear relationship rather than linear relationship between post‐traumatic growth and positive factors in the sample of nursing students.
Non‐surgical periodontal therapy with systemic antibiotics in patients with untreated aggressive periodontitis: a systematic review and meta‐analysis
Authors: Keestra J. A. J. , Grosjean I. , Coucke W. , Quirynen M. , Teughels W.
Published: December 2014

Objective

The purpose of this meta‐analysis is to evaluate the effectiveness of different systemic antibiotics in combination with scaling and root planing (SRP) compared to SRP alone in patients with untreated aggressive periodontitis.

Background

In patients with aggressive periodontitis, SRP is often combined with the use of systemic antibiotics. However, the effectiveness of these antibiotics over time and differences in effectiveness between different antibiotics are hardly known.

Material and Methods

The MEDLINE‐PubMed database was searched from their earliest records until January 20, 2014. Several journals were hand searched and some authors were contacted for additional information. The following outcome measures were analysed: mean probing pocket depth reduction, mean clinical attachment level gain and mean bleeding on probing change. Extracted data were pooled using a random effect model. Weighted mean differences were calculated and heterogeneity was assessed.

Results

The search yielded 296 abstracts. Ultimately, 101 articles were selected of which 14 articles met the eligibility criteria. Systemic antibiotics showed a significant (p < 0.05) additional pocket depth reduction for moderate (0.36 ± 0.22 mm at 3 mo, 6 mo 0.42 ± 0.22 mm and 12 mo 0.88 ± 0.27 mm) and deep pockets (0.74 ± 0.36 mm at 3 mo, 6 mo 0.85 ± 0.55 mm and 12 mo 1.26 ± 0.81 mm) and a significant clinical attachment gain for moderate (0.26 ± 0.18 at 3 mo, 6 mo 0.52 ± 0.15 and 12 mo 0.83 ± 0.38) and deep pockets (0.59 ± 0.18 at 3 mo, 0.96 ± 0.21 at 6 mo and 1.00 ± 0.80 at 12 mo).

Conclusion

For the treatment of patients with aggressive periodontitis, systemic antibiotics combined with non‐surgical periodontal therapy resulted in a significant additional effect compared to non‐surgical therapy alone. There is a visible trend that showed metronidazole + amoxicillin is the most potent antibiotic combination.
Sleep characteristics as predictor variables of stress systems markers in insomnia disorder
Authors: Floam Samantha , Simpson Norah , Nemeth Emese , Scott‐Sutherland Jennifer , Gautam Shiva , Haack Monika
Published: December 2014

This study investigates the extent to which sleep characteristics serve as predictor variables for inflammatory, hypothalamic–pituitary–adrenal and autonomic systems markers. Twenty‐nine participants with a diagnosis of insomnia disorder based on the Diagnostic Statistical Manual of Mental Disorders, Fifth Edition (age 25.3 ± 1.6 years, insomnia duration 6.6 ± 0.8 years) and 19 healthy control sleepers (age 25.4 ± 1.4 years) underwent a 2‐week at‐home evaluation keeping a sleep diary and wearing an actigraph, followed by a visit to the Research Center to measure blood pressure, and collect blood and urine samples. The actigraphy‐ and diary‐based variables of sleep duration, sleep‐onset latency, wake after sleep onset and sleep fragmentation/number of night‐time awakenings were averaged and entered as dependent variables in regression analyses. Composite scores were calculated for the autonomic (blood pressure, norepinephrine), inflammatory (monocyte counts, interleukin‐6, C‐reactive protein) and hypothalamic–pituitary–adrenal systems (cortisol), and used as predictor variables in regression models. Compared with controls, individuals with insomnia had a shorter sleep duration (P < 0.05), and a higher hypothalamic–pituitary–adrenal and inflammatory composite score (P < 0.05). The higher inflammatory score was mainly due to higher circulating monocytes (P < 0.05), rather than differences in interleukin‐6 or C‐reactive protein. In persistent insomnia disorder, cortisol is upregulated and associated with actigraphy‐ and diary‐based wake after sleep onset, suggesting that wake after sleep onset may serve as a marker to identify individuals at increased risks for disorders associated with a hyperactive hypothalamic–pituitary–adrenal system. The absence of autonomic and pro‐inflammatory changes (interleukin‐6, C‐reactive protein), despite a substantial decrease in actigraphic sleep duration, may relate to a higher resilience to the adverse biological consequences of insomnia in this young age group.
The spliceosomal PRP19 complex of trypanosomes
Authors: Ambrósio Daniela L. , Badjatia Nitika , Günzl Arthur
Published: December 2014

In trypanosomes, mRNAs are processed by spliced leader (SL) trans splicing, in which a capped SL, derived from SL RNA, is spliced onto the 5′ end of each mRNA. This process is mediated by the spliceosome, a large and dynamic RNA‐protein machinery consisting of small nuclear ribonucleoproteins (snRNPs) and non‐snRNP proteins. Due to early evolutionary divergence, the amino acid sequences of trypanosome splicing factors exhibit limited similarity to those of their eukaryotic orthologs making their bioinformatic identification challenging. Most of the ∼ 60 protein components that have been characterized thus far are snRNP proteins because, in contrast to individual snRNPs, purification of intact spliceosomes has not been achieved yet. Here, we characterize the non‐snRNP PRP19 complex of Trypanosoma brucei. We identified a complex that contained the core subunits PRP19, CDC5, PRL1, and SPF27, as well as PRP17, SKIP and PPIL1. Three of these proteins were newly annotated. The PRP19 complex was associated primarily with the activated spliceosome and, accordingly, SPF27 silencing blocked the first splicing step. Interestingly, SPF27 silencing caused an accumulation of SL RNA with a hypomethylated cap that closely resembled the defect observed previously upon depletion of the cyclin‐dependent kinase CRK9, indicating that both proteins may function in spliceosome activation.
Biochemical composition of haemagglutinin‐based influenza virus‐like particle vaccine produced by transient expression in tobacco plants
Authors: Le Mauff François , Mercier Geneviève , Chan Philippe , Burel Carole , Vaudry David , Bardor Muriel , Vézina Louis‐Philippe , Couture Manon , Lerouge Patrice , Landry Nathalie
Published: December 2014

Influenza virus‐like particles (VLPs) are noninfectious particles resembling the influenza virus representing a promising vaccine alternative to inactivated influenza virions as antigens. Medicago inc. has developed a plant‐based VLP manufacturing platform allowing the large‐scale production of GMP‐grade influenza VLPs. In this article, we report on the biochemical compositions of these plant‐based influenza candidate vaccines, more particularly the characterization of the N‐glycan profiles of the viral haemagglutinins H1 and H5 proteins as well as the tobacco‐derived lipid content and residual impurities. Mass spectrometry analyses showed that all N‐glycosylation sites of the extracellular domain of the recombinant haemagglutinins carry plant‐specific complex‐type N‐glycans having core α(1,3)‐fucose, core β(1,2)‐xylose epitopes and Lewisa extensions. Previous phases I and II clinical studies have demonstrated that no hypersensibility nor induction of IgG or IgE directed against these glycans was observed. In addition, this article showed that the plant‐made influenza vaccines are highly pure VLPs preparations while detecting no protein contaminants coming either from Agrobacterium or from the enzymes used for the enzyme‐assisted extraction process. In contrast, VLPs contain few host cell proteins and glucosylceramides associated with plant lipid rafts. Identification of such raft markers, together with the type of host cell impurity identified, confirmed that the mechanism of VLP formation in planta is similar to the natural process of influenza virus assembly in mammals.
Interaction of Crown Ether‐Annelated Styryl Dyes with Double‐Stranded DNA
Authors: Berdnikova Daria V. , Fedorova Olga A. , Tulyakova Elena V. , Li Haixing , Kölsch Sarah , Ihmels Heiko
Published: December 2014

DNA‐binding properties of 15‐crown‐5‐derived mono‐ and bis‐styryl dyes were investigated in the presence of calf thymus DNA. To access the factors that influence the DNA association in the series of these ligands, the structure of the molecules was varied by either changing size of the heterocyclic moiety or altering the position of the styryl substituents. The major binding mode for the monostyryl dyes is intercalation. Notably, binding of the dyes to the nucleic acids leads to a fluorescence enhancement by a factor of up to 54. Therefore, these cationic styryl derivatives may be applied as fluorescent “light‐up” probes for DNA detection.
The Right Mix? Gender Diversity in Top Management Teams and Financial Performance
Authors: Opstrup Niels , Villadsen Anders R.
Published: December 2014

Recent research has illustrated that demographic diversity influences the outcomes of public sector organizations. Most studies have focused on workforce diversity; by comparison, little is known about how managerial diversity affects organizational outcomes. This article focuses on gender diversity in the top management teams of public organizations and its relationship to financial performance. Theory suggests that management diversity can be a positive asset for organizations, allowing for the use of more diverse knowledge and human skill sets. Results of this study, however, suggest that organizations may only be able to leverage these advantages if they have a supporting management structure. In a longitudinal study of top management teams in Danish municipalities, the authors find that gender diversity in top management teams is associated with higher financial performance, but only in municipalities with a management structure that supports cross‐functional team work. These results are interpreted in light of existing theory, and implications are suggested.
Portopulmonary hypertension: An update
Authors: Porres‐Aguilar Mateo , Mukherjee Debabrata
Published: December 2014

Portopulmonary hypertension represents a serious lung vascular disorder, defined as the presence of pulmonary arterial hypertension that is associated with portal hypertension, with or without the presence of significant liver disease. Transthoracic echocardiography represents the single best initial tool for the diagnostic evaluation in portopulmonary hypertension, and right heart catheterization remains the gold standard for definitive diagnosis. Despite the lack of randomized controlled trials in portopulmonary hypertension, some therapies have demonstrated improvements in cardiopulmonary haemodynamics and right ventricular function as described in case reports and case series. Specialists should be able to recognize indications and contraindications for liver transplantation in the setting of portopulmonary hypertension, and this review focuses on the appropriate diagnostic approach and current advances in medical therapies. Recognition of patients eligible for liver transplantation is needed to improve quality of life and survival.
Depositional system and palaeoclimatic interpretations of Middle to Late Pleistocene travertines: Kocabaş, Denizli, south‐west Turkey
Authors: Toker Ezher , Kayseri‐Özer Mine Sezgül , Özkul Mehmet , Kele Sándor
Published: December 2014

Travertine deposits in western Turkey are very well‐exposed in the area of Kocabaş, in the eastern part of the Denizli Basin. The palaeoclimatic significance of these travertines is discussed using U/Th dates, stable isotope data and palynological evidence. The Kocabaş travertine occurrences are characterized by successions of depositional terraces associated with palaeosols and karstic features. The travertines have been classified into eight lithotypes and one erosional horizon, namely: laminated, coated bubble, reed, paper‐thin raft, intraclasts, micritic travertine with gastropods, extra‐formational pebbles and a palaeosol layer. The analysed travertines mostly formed between 181 ka and 80 ka (Middle to Late Pleistocene) during a series of climatic changes including glacial and interglacial intervals; their δ13C and δ18O values indicate that the depositional waters were mainly of basinal thermal origin, occasionally mixed with surficial meteoric water. Palynological results obtained from the palaeosols showed an abundance of non‐arboreal percentage and xerophytic plants (Oleaceae and Quercus evergreen type) indicating that a drought occurred. Marine Isotope Stage 6 is represented by grassland species but Marine Isotope Stage 5 is represented by Pinaceae–Pinus and Abies, Quercus and Oleaceae. Uranium/thorium analyses of the Kocabaş travertines show that deposition began in Marine Isotope Stage 6 (glacial) and continued to Marine Isotope Stage 4 (glacial), but mostly occurred in Marine Isotope Stage 5 (interglacial). The travertine deposition continued to ca 80 ka in the south‐west of the study area, in one particular depression depositional system. Palaeoenvironmental indicators suggest that the travertine depositional evolution was probably controlled by fault‐related movements that influenced groundwater flow. Good correlation of the stable isotope values and dates of deposition of the travertines and palynological data of palaeosols in the Kocabaş travertines serve as a starting point for further palaeoclimate studies in south‐west Turkey. Additionally, the study can be compared with other regional palaeoclimate archives.
Postthaw characterization of umbilical cord blood: markers of storage lesion
Authors: Hubel Allison , Spindler Ralf , Curtsinger Julie M. , Lindgren Bruce , Wiederoder Sara , McKenna David H.
Published: December 2014

Background

The continued growth in the uses of umbilical cord blood (UCB) will require the development of meaningful postthaw quality assays. This study examines both conventional and new measures for assessing UCB quality after long‐term storage.

Study Design and Methods

The first arm of the study involved thawing UCB in storage for short (approx. 1 year) and long periods of time (>11 years). Conventional postthaw measures (colony‐forming units [CFU], total nucleated cell counts, CD34+45+) were quantified in addition to apoptosis. The second arm of the study involved taking units stored in liquid nitrogen and imposing a storage lesion by storing the units in −80°C for various periods of time. After storage lesion, the units were thawed and assessed.

Results

In the first arm of the study, there was little difference in the postthaw measures between UCB stored for short and long periods of time. There was a slight increase in the percentage of CD34+45+ cells with time in storage and a reduction in the number of cells expressing apoptosis markers. When moved from liquid nitrogen to −80°C storage, the nucleated cell count varied little but there was a distinct decrease in frequency of CFUs and increase in percentage of cells expressing both early and late markers of apoptosis.

Conclusion

Nucleated cell counts do not reflect damage to hematopoietic progenitors during long‐term storage. Expression of caspases and other markers of apoptosis provide an early biomarker of damage during storage, which is consistent with other measures such as CFU and percentage of CD34+45+ cells.
Steroid production and membrane potential measurement in cells of the adrenal cortex
Authors: Matthews E. K. , Saffran M.
Published: December 2014

1. The relation between corticosteroid production and the cellular membrane potential of adrenocortical cells has been investigated using a flow system for the incubation in vitro of adrenal glands from neonatal rabbits. Corticosteroid production by the adrenal cells was determined by a fluorescence method; membrane potentials were measured with glass micro‐electrodes.

2. Adrenocorticotrophic hormone (ACTH) increased corticosteroid production without altering the membrane potential of the adrenocortical cells. Conversely, a 5‐fold increase in [K]o did not increase corticosteroid production but decreased the cellular membrane potential. The increase in [K]o did not impair the stimulation of corticosteroid production by ACTH.

3. The log dose—response relation between the concentration of ACTH in the incubation medium and the amount of corticosteroid produced by the adrenal tissue was linear.

4. No evidence was found of a direct relation between the production of corticosteroid by adrenocortical cells and the cellular membrane potential. Indeed, the output of steroid appeared to be relatively independent of the polarization of the cell membrane.
Hyperpyruvaturia in experimental diabetes
Authors: Anderson J. , Coulson R. , Tomlinson R. W. S.
Published: December 2014

1. The 24 hourly excretion of pyruvate and glucose has been measured in alloxan‐diabetic rats.

2. The animals were allowed a 6‐day control period before being injected with alloxan (
I.V. 50 mg/kg body weight). The diabetes was treated by daily injections of insulin for a period of 6 days from the 7th to the 12th day following the alloxan injection.

3. The pyruvate excretion increased more than 5‐fold following the induction of diabetes, the values being 189 ± 130 (
S.D.) μg/24 hr in the control period rising to an average of 1002 ± 664 (
S.D.) μg/24 hr over the first 6 days of diabetes. The administration of insulin over the second 6‐day period of diabetes caused the pyruvate excretion to decrease—though not significantly. Upon the withdrawal of the insulin treatment the pyruvate excretion increased significantly from 785 ± 315 (
S.D.) μg/24 hr to 2105 ± 679 (
S.D.) μg/24 hr, measured over a 5‐day period. The final period of pyruvate excretion was significantly greater than the excretion over the first diabetic period.

4. The glucose excretion during the initial diabetic period was 6·75 ± 2·64 (
S.D.) g/24 hr. The administration of insulin caused a 42% decrease in glucose excretion compared to a decrease of 22% for the pyruvate. The withdrawal of insulin caused the glucose excretion to increase by 149% while the pyruvate excretion increased by 157%.

5. Diabetes was also induced temporarily by injections of anti‐insulin serum and diazoxide. In each case significant glycosuria and hyperpyruvaturia were produced.

6. The possible causes of the hyperpyruvaturia in diabetes are discussed.
Monoamines and their metabolites in the avian brain
Authors: Juorio A. V. , Vogt Marthe
Published: December 2014

1. In the avian brain, a high concentration of dopamine was found in a sharply contoured region of the nucleus basalis which may or may not have included the nucleus entopeduncularis, and therefore lay within the palaeostriatum of the nomenclature of Crosby and Huber. This was thus the only region which may be considered biochemically homologous to the mammalian corpus striatum. For purposes of macroscopic identification only, the region is described here as the ‘anterior part of the nucleus basalis’. The concentration of dopamine was 3 μg/g in the pigeon, about the same in the duck and chicken, and 7·5 μg/g in the finch. In the pigeon this region also contained some noradrenaline; the quantity of 5‐hydroxytryptamine (1·4 μg/g) and 5‐hydroxyindolylacetic acid (0·6 μg/g) was larger than in any other part of the brain.

2. In the brain of the pigeon and the chicken, the highest concentrations of noradrenaline (1·5 and 1·4 μg/g) were found in the hypothalamus.

3. The concentration of adrenaline was higher in the avian than in the mammalian brain. In the hypothalamus, it ranged from 0·4 μg/g in the pigeon to 1 μg/g in the chicken.

4. Fluorescence microscopy, using the formaldehyde condensation method, showed, in the anterior part of the nucleus basalis, a large area of diffuse green‐yellow fluorescence, similar in appearance to the fluorescence of the striatum of the rat. In addition this part of the brain contained a small region of fluorescent fibres and varicosities. It is suggested that the diffuse fluorescence was produced by dopamine. It was absent from brains of reserpine‐treated pigeons.

5. In the pigeon, reserpine, tetrabenazine and prenylamine produced a decrease in the concentration of brain monoamines, an effect which was comparable to that seen in mammals. Yet, none of these drugs raised the concentration of homovanillic acid, but they increased that of 5‐hydroxyindolylacetic acid; these drugs raise the concentration of both acids in mammalian brain.

6. In the pigeon β‐tetrahydronaphthylamine decreased the concentration of all monoamines and their metabolites, an action quite different from that produced in the mammalian brain.

7. The main effect of morphine and of M 99 (6,14‐endoetheno‐7‐(2‐hydroxy‐2‐pentyl)‐tetrahydro‐oripavine hydrochloride) was a lowering of the noradrenaline concentration.

8. As in mammals, chlorpromazine affected only the dopamine metabolism.

9. In the guinea‐pig and the pigeon, the administration of α‐methyl‐DOPA led to a substitution of much of the cerebral noradrenaline by α‐methyl‐noradrenaline, sometimes in excess of the lost noradrenaline. However, although the loss of dopamine was severe in both pigeon and guinea‐pig, only little α‐methyl‐dopamine accumulated in the pigeon brain, so that it did not consitute a replacement for the lost dopamine; in the guinea‐pig, α‐methyl‐dopamine was found in quantities similar to, or exceeding those, of the lost dopamine.
The nature of rise in threshold produced by contrast‐flashes
Authors: Alpern M. , Rushton W. A. H.
Published: December 2014

1. The rod threshold for seeing a flash on a 2½° square is raised by a nearly simultaneous flash that falls on the surround. When this ‘contrast‐flash’ is held fixed in intensity, it raises the log test threshold by a fixed amount no matter how far that threshold has already been raised by light adaptation owing to background or bleaching.

2. This is surprising since fixed backgrounds and bleachings raise the log test threshold much more when the eye is dark than when light adapted.

3. When the test flash is held at some fixed supra‐threshold value, the contrast flash exhibits a ‘critical level’, above which the test will no longer be seen. If the surround region upon which the contrast‐flash falls is adapted by background or bleaching, its efficacy is reduced so that the ‘critical level’ is raised.

4. Surround adaptation raises the log ‘critical level’ by the same amount that it raises the log threshold for seeing the contrast‐flash itself.

5. The way that contrast flashes raise the test threshold is thus entirely different from the way that adaptations by bleachings or backgrounds do. Contrast‐flash signals appear to inhibit test‐flash signals by interaction at some point central to the site where adaptation occurs.

6. This permits the effect of adaptation on signals to be measured. A given state of adaptation attenuates all flash signals in the same proportion. And in any state of adaptation a single flash will reach threshold when the attenuated signal has a fixed size.
The timing of calcium action during neuromuscular transmission
Authors: Katz B. , Miledi R.
Published: December 2014

1. When a nerve—muscle preparation is paralysed by tetrodotoxin, brief depolarizing pulses applied to a motor nerve ending cause packets of acetylcholine to be released and evoke end‐plate potentials (e.p.p.s), provided calcium ions are present in the extracellular fluid.

2. By ionophoretic discharge from a 1
M‐CaCl2 pipette, it is possible to produce a sudden increase in the local calcium concentration at the myoneural junction, at varying times before or after the depolarizing pulse.

3. A brief application of calcium facilitates transmitter release if it occurs immediately before the depolarizing pulse. If the calcium pulse is applied a little later, during the period of the synaptic delay, it is ineffective.

4. It is concluded that the utilization of external calcium ions at the neuromuscular junction is restricted to a brief period which barely outlasts the depolarization of the nerve ending, and which precedes the transmitter release itself.

5. The suppressing effect of magnesium on transmitter release was studied by a similar method, with ionophoretic discharges from a 1
M‐MgCl2‐filled pipette. The results, though not quite as clear as with calcium, indicate that Mg pulses also are only effective if they precede the depolarizing pulses.
Observations on carotid body chemoreceptor activity and cervical sympathetic discharge in the cat
Authors: Biscoe T. J. , Purves M. J.
Published: December 2014

1. Parallel recordings have been made of the cervical sympathetic and carotid body chemoreceptor activity in the anaesthetized cat.

2. The sympathetic activity remains remarkably constant while the chemoreceptor activity is varied by changes in the blood gas tensions of relatively short duration.

3. Changes in intrathoracic pressure by obstruction to the airway or thoracic compression were associated with changes in the activity of both nerves.

4. It is likely that, under normal conditions, the sympathetic nervous activity provides a stable vasomotor tone within the carotid body.
The active transport of fluorescein by the retinal vessels and the retina
Authors: Cunha-Vaz J. G. , Maurice D. M.
Published: December 2014

1. The movement of fluorescein across the retinal surface of the rabbit's eye was estimated by measuring the concentration gradient of the dye in the vitreous body. These measurements were made in vivo by means of a slit‐lamp fluorophotometer, or were taken from frozen sections of enucleated eyes.

2. In the normal eye, fluorescein does not pass from the blood to the vitreous body across any part of the retina. When injected into the vitreous body it passes rapidly out across the entire retinal surface, even against a very large concentration gradient.

3. A variety of metabolic and competitive inhibitors, effective in blocking organic anion transport in the kidney and liver, tend to abolish this unidirectional movement of fluorescein across the retina.

4. The region occupied by the retinal vessels is more sensitive to inhibition than other areas of the retina. Occlusion of the vessels by diathermy prevents the exchange of fluorescein in this region.

5. It appears, then, that there is an active transport of organic anions out of the vitreous body, both by the retinal capillaries and by the retina itself. The latter system is probably located in the pigment epithelium and seems to be carried forward to the rear surface of the iris.

6. Since the walls of the retinal vessels of the rabbit are freely in contact with the vitreous body, the active transport must take place across the capillary endothelial cells themselves. These vessels have structural and permeability characteristics found only in the central nervous system and it is to be presumed that the anion transport system is shared by the capillaries of the brain.

7. The function of the transport in the retina may be to protect the nervous tissue from toxic materials by preventing their entry from the blood or by removing products of metabolism conjugated as organic anions. Alternatively, the mechanism may be concerned in maintaining the normal adhesion of the retina to the choroid, since retinal detachment was observed to follow its total inhibition.
Disuse in the lateral geniculate nucleus of the cat
Authors: Burke W. , Hayhow W. R.
Published: December 2014

1. An attempt has been made to produce disuse in the lateral geniculate nucleus (LGN) of the cat, in the synapses between the optic nerve fibres and the principal cells of the nucleus. Evidence is produced that destruction of the visual receptor cells by iodoacetate or 1,5‐di(p‐aminophenoxy) pentane dihydrochloride effectively silences the optic nerve discharge and so achieves this result.

2. Disuse of the LGN synapses does not cause any decrease in synaptic efficiency. The LGN response to a single stimulus to the optic nerve was not appreciably altered, and the depression which normally follows single or repeated stimuli was much reduced or absent. This increased responsiveness was unaffected by prolonged tetanization of the optic nerve during the experiment.

3. Two possible explanations of the increased responsiveness are suggested: a post‐synaptic ‘decentralization’‐hypersensitivity and an increased output of transmitter per impulse. The relevance of these results to theories of learning is discussed.

4. The LGN response of adult cats kept in complete darkness for periods of up to 966 days was not appreciably different from that in the normal cat and there was little or no increased responsiveness. This suggests that many retinal ganglion cells continue to discharge in total darkness for long periods. There is a possibility that disuse may develop after a long time in the dark.
Early effects of abrupt reduction of local pressure on the forearm and its circulation
Authors: Caro C. G. , Foley T. H. , Sudlow M. F.
Published: December 2014

1. The pressure at the surface of a segment of forearm enclosed in a plethysmograph was abruptly reduced from atmospheric to ‐20 to ‐120 mm Hg.

2. Forearm circumference (equivalent to the volume of a small segment of forearm (Vf)) was measured with a strain gauge. Pressure was measured in the plethysmograph (Pp), in veins exposed (Pve) and not exposed (Pvne) to suction, in the brachial artery not exposed to suction (Pbane) and in forearm tissue (Pt).

3. Reduction of Pp caused increase of Vf. This was not due to gas evolution, since bubbles would not be liberated at the pressures employed. Nor was increase of Vf due to venous backflow since Pve fell, but Pvne did not, even with upper arm circulation occluded or when Pvne was raised by venous occlusion prior to reduction of Pp.

4. Reduction of Pp temporarily arrested venous outflow since Pve < Pvne < Pbane for 30 sec. With reduction of Pp 30 sec after occlusion of the upper‐arm circulation, Pve < Pvne for > 1 min, indicating that arterial inflow was then minimal.

5. Increase of Vf, following reduction of Pp, was therefore due to inflow of arterial blood, of soft tissue or interstitial fluid. Interstitial fluid could flow from regions external to the plethysmograph, or enter as the result of filtration across capillaries. Occlusion of the upper arm circulation was not expected to interfere with motion of forearm soft tissue or the intratissue flow of interstitial fluid. It appears that capillary filtration is small compared with observed blood flow. Therefore subtraction of Vfoccl measured at intervals after reduction of Pp (upper arm circulation occluded) from Vf similarly obtained (but upper arm circulation free) appeared to give change of forearm volume due to inflow of arterial blood (ΔVb). V̇b, the volume inflow rate of arterial blood during suction, was then obtained.

6. Resting forearm flow was 1·8 ml./min/100 ml. in seven normal subjects (average mean arterial blood pressure 86 mm Hg). With Pp = ‐90 mm Hg, V̇b was 10·2 ml./min/100 ml. Suction therefore reduced vascular resistance, measured as (Pbane—Pve) /V̇b.
The ontogeny of electrical activity associated with absorption of solutes across the developing small intestine of the chick (Gallus domesticus)
Authors: Hudson D. A. , Levin R. J.
Published: December 2014

1. Electrical potentials across the developing intestine of the chick were measured in vitro 3‐4 days before and up to 32 days after hatching.

2. Embryonic intestine had a very high endogenous p.d. (serosa positive to mucosa) which decreased up to hatching. This decrease continued during intestinal maturation, reaching a basal level several days after hatching.

3. Transfer potential differences were caused only by the actively transferred hexoses both in embryonic and post‐embryonic intestine. These potentials decreased concomitantly with the decrease in the endogenous p.d. Kinetic analysis showed that the ‘apparent Km’ of glucose for the glucose transfer p.d. generating mechanism did not change over the period of hatching.

4. Both the embryonic and post‐embryonic transmural p.d. either in the presence or absence of metabolizable hexose was dependent upon aerobic metabolism.

5. The transmural p.d. of hatched chick small intestine (with and without hexoses) was linearly related to log10[Na+] of the mucosal fluid. The magnitude of the glucose transfer p.d. both in embryonic and post‐embryonic small intestine, however, was not lowered by decreasing the mucosal [Na+].

6. Amino acid transfer potentials were of small magnitude at all stages of development.
Kinins, beta‐adrenergic receptors and functional vasodilatation in the submaxillary gland of the cat
Authors: Skinner N. Sheldon , Webster Marion E.
Published: December 2014

1. The close arterial infusion of bradykinin into the submaxillary gland of the cat produced a pronounced hyperaemia that could be blocked by simultaneous perfusion of the gland with blood containing carboxypeptidase B. Carboxypeptidase B, however, failed to reduce the vasodilatation of chorda tympani nerve stimulation suggesting that the kinins are not involved in the regulation of submaxillary gland blood flow.

2. Isoproterenol injections produced pronounced salivary gland vasodilatation. Beta‐adrenergic blocking drugs reduced or abolished the hyperaemia of isoproterenol and reduced that of chorda tympani nerve stimulation. The combination of beta‐blocking drugs and atropine could abolish or reduce further this nerve induced hyperaemia.

3. The above results suggest that stimulation of cholinergic and beta‐adrenergic receptors could account for the chorda tympani induced hyperaemia. Conclusive proof of this possibility remains to be determined.
The role of plasma kinin in functional vasodilatation in the pancreas
Authors: Hilton S. M. , Jones Muriel
Published: December 2014

1. Freshly collected pancreatic juice of the cat contained active kinin‐forming enzyme (kallikrein) and, in addition, an active kininase.

2. In response to successive doses of secretin, the kinin‐forming activity of pancreatic juice fell off considerably. It was restored by pancreozymin.

3. Stimulation of the dorsal vagus nerve caused an increase in venous outflow from the pancreas which was greater and more consistently seen when the splanchnic nerves had been sectioned.

4. Intravenous injection of highly purified secretin usually had no effect on the outflow, whereas pancreozymin increased it up to 5 times.

5. When the pancreas was perfused with oxygenated Locke solution, the effluent contained some kinin‐forming enzyme when the gland was at rest. The enzyme activity did not increase when secretin was added to the perfusing fluid, but when acetylcholine or pancreozymin was added, the activity rose about fourfold.

6. These results are discussed in relation to the theory that plasma kinins play a prominent role in the functional vasodilatation of glandular tissues.
The release of nucleotides, 5‐hydroxytryptamine and enzymes from human blood platelets during aggregation
Authors: Mills D. C. B. , Robb I. A. , Roberts G. C. K.
Published: December 2014

1. Adenosine diphosphate (ADP) and adrenaline caused the aggregation of human platelets suspended in plasma containing citrate anticoagulant and stirred at 37° C. The aggregation occurred in two phases and the second phase was associated with the appearance in the plasma of up to 30% of the ATP and 55% of the ADP present in the platelets. The concentration of ADP appearing in the plasma was up to 7 times the concentration added.

2. Radioactivity was released by ADP and by adrenaline from platelets labelled with radioactive 5‐hydroxytryptamine; this release was closely correlated with the second phase of aggregation and with the release of nucleotides.

3. Acid phosphatase, β‐glucuronidase and adenylate kinase were released to a small extent during second phase aggregation by ADP or adrenaline; thrombin and collagen particles caused significantly greater release of β‐glucuronidase than of either acid phosphatase or of adenylate kinase.

4. Morphological changes indicating degranulation of the platelets were observed during the second phase of aggregation produced by adrenaline and by ADP.

5. The second phase of aggregation, degranulation of platelets, and the release of nucleotides, of labelled 5‐hydroxytryptamine and of enzymes, were all inhibited by concentrations of amitriptyline which did not inhibit aggregation.