bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of Amino Acids and Peptides on Mixing and Frozen Dough Properties of Wheat Flour
Authors: Koh Bong‐Kyung , Lee Gui‐Chu , Lim Seung‐Taik
Published: August 2010

Free amino acids, peptides, and vital wheat gluten were investigated to determine their effect on the mixing and frozen dough baking properties of wheat flour. Addition of 1% cysteine and aspartic acid decreased and glutamic acid, histidine, arginine, and lysine increased the mixing tolerance of flour. Cystine, methionine, tryptophan, and phenylalanine increased but isoleucine, histidine, glycine, arginine, glutamic acid, aspartic acid, and lysine decreased loaf volume of nonfrozen dough breads. However cystine, methionine, tryptophan, and phenylalanine did not increase loaf volume of bread prepared from frozen dough. Vital wheat gluten increased mixing tolerance and bread loaf volume only for the nonfrozen dough. However, wheat gluten hydrolysate, corn, and bonito peptides decreased mixing tolerance after optimum mixing time and were effective in increasing loaf volume for both frozen and nonfrozen dough. As the amount of corn and bonito peptide increased, specific loaf volumes also increased. Addition of 2.5% corn peptide was most effective in increasing loaf volume of frozen dough bread. Crust browning and crumb stickiness increased, whereas crumb softness decreased with addition of peptides. Addition of less than 1% peptide did not adversely affect the aftertaste and off‐flavor of bread. These results suggest that addition of peptides are effective for improving the baking quality of frozen dough, whereas amino acids and gluten have no effect.
Effects of Food Processing on Blueberry Antiproliferation and Antioxidant Activity
Authors: Schmidt Barbara M. , Erdman John W. , Lila Mary Ann
Published: August 2010

Cultivated highbush (Vaccinium corymbosum L.) and wild lowbush (Vaccinium angustifolium Ait.) blueberries are excellent sources of phytochemicals that are believed to have significant biological activity. The objective of this study was to determine whether incorporation of blueberries into food products affects their phenolic content or antioxidant and antiproliferation activity. Several blueberry fruit‐containing products including fresh, individually quick frozen (IQF), freeze‐dried, spray‐dried, heat‐dried, cooked, juice concentrate, pie filling, and jam were fractionated to remove sugars and isolate groups of phytochemicals based on solubility. The fractions were analyzed for total phenolics and assayed for ferric reducing antioxidant power (FRAP) antioxidant activity, 2,2‐diphenyl‐1‐picrylhydrazyl (DPPH) radical scavenging activity, and hepa‐1c1c7 antiproliferative activities. For both cultivated and wild berries, fresh and IQF berries had the highest total phenols, antioxidant activity, and antiproliferation activity. Whole freeze‐dried wild blueberries also retained significant antiproliferative activity in 2 fractions eluted with acetone (fraction 4, 4% of control cell growth at 20 (μg/mL) and 50% aqueous acetone (fraction 5, 69% of control cell growth at 20 (μg/mL) and ranked close to the activities recorded for fresh (30% of control cell growth at 20 (μg/mL for fraction 5) and IQF whole fruit (27% of control cell growth at 20 (μg/mL for fraction 5). Products that were heat‐processed retained most of the antioxidant activity and total phenolics found in unprocessed whole fruit. However, the heat‐treated products lacked or had diminished antiproliferation activity, suggesting that although products may be high in phenolic compounds and antioxidant activity, some forms of bioactivity may be compromised by harsh processing methods.
Role of Cooling Process in the Thermal Aggregate Formation by Carp Myosin Rod
Authors: Sasaki Tomoko , Yuan Chunhong , Konno Kunihiko
Published: August 2010

Carp myosin rod solution did not show detectable turbidity upon heating at 80 °C. Rod aggregation was detected only by high sensitive light scattering intensity and gel filtration analysis on Sepharose CL 4B. Roughly half of myosin rod was still monomeric for sample heated at 80 °C at 2 mg/mL. Prolonged heating at 80 °C did not increase the amount of aggregates. Aggregation was prominent at high concentration of rod. Rod aggregation was promoted by cooling of the heated rod solution. Heating at 80 °C completely unfolded the α‐helix structure of rod. However, α‐helix structure was significantly recovered by about 85% upon cooling. Unfolding and aggregation analysis revealed that complete unfolding of whole rod structure was needed for aggregation, and the cooling process accompanying refolding of helical structure was important for aggregate formation.
Sorption Behavior of Crawfish Chitosan Films as Affected by Chitosan Extraction Processes and Solvent Types
Authors: Nadarajah Kandasamy , Prinyawiwatkul Witoon , No Hong Kyoon , Sathivel Subramaniam , Xu Zhimin
Published: August 2010

Effects of chitosan extraction processes and solvent types on sorption behavior of unplasticized crawfish chitosan films were investigated. Four different chitosans prepared from crawfish shell were dissolved in 1% v/v acetic, formic, lactic, or malic acids at 1% w/v concentration. Chitosans dissolved in acetic or formic acid formed flexible and transparent films that are desirable for packaging applications. Chitosan acetate films maintained lower moisture contents at any relative humidity level compared with chitosan formate films. The type of chitosan significantly influenced the sorption isotherms of chitosan formate films but not chitosan acetate films. The Guggenheim‐Anderson‐de Boer, Oswin, and Caurie models (R2= 0.98, 0.95, and 0.95, respectively) could be used to predict sorption behavior of crawfish chitosan acetate and formate films.
Modeling of Sucrose Permeation through a Pectin Gel During Ultrafiltration of Depectinized Mosambi [Citrus sinensis (L.) Osbeck] Juice
Authors: Rai Pramod , Majumdar G.C. , DasGupta Surnando , De Sirshendu
Published: August 2010

Ultrafiltration of synthetic juice (mixture of sucrose and pectin with varying composition) as well as enzymatically treated mosambi [Citrus sinensis (L.) Osbeck] juice is performed in a batch, unstirred membrane cell. Thin‐film composite polyamide membrane of molecular weight cutoff 50000 was used. The flux decline mechanism is found to be controlled by the growth of a gel layer of pectin over the membrane surface. Using standard cake filtration theory, the flux decline and the growth of gel layer is quantified. The gel layer is characterized in terms of specific gel layer resistance, gel porosity, and gel density. A transient model is proposed and solved numerically to quantify the transport of sucrose through the pectin gel for the synthetic juice and enzymatically treated juice. The hindered diffusion coefficient of sucrose through the gel is calculated by comparing the results with the experimentally obtained permeate concentration profile of sucrose. The calculated permeate concentration profile agrees well with the experimental data.
Thermal Inactivation of Salmonella on Cantaloupes Using Hot Water
Authors: Solomon Ethan B. , Huang Lihan , Sites Joseph E. , Annous Bassam A.
Published: August 2010

The inactivation of Salmonella on cantaloupes using hot water was investigated. Whole melons, inoculated with a cocktail of Salmonella isolates, were subjected to thermal treatments of various lengths in water at 65 °C, 75 °C, and 85 °C. Treatment with water at 85 °C for 60 and 90 s resulted in reductions of up to 4.7 log colony forming units (CFU) per square centimeter of rind. However, the rind of melons treated at 85 °C for 90 s were noticeably softer than the rind of melons treated for 60 s. Thermal penetration profiles were measured and computer simulations were conducted to verify the effect of hot water treatment conditions on the internal temperatures of cantaloupe melons. Experimental and simulation data indicated that the internal temperature of melons treated with hot water did not increase rapidly compared with the rind temperature. Regardless of the process temperature used, the temperature of the edible flesh, 10 mm from the surface of the rind, remained at least 40 °C cooler than the surface temperature of cantaloupe melons. These results demonstrate the utility of hot water for the inactivation of Salmonella on cantaloupes and provide a framework to producers of fresh‐cut melon for the potential use of hot water as an intervention treatment.
Multiple Comparison Procedures for Analysis of Ranked Data
Authors: Christensen Zeke T. , Ogden Lynn V. , Dunn Michael L. , Eggett Dennis L.
Published: August 2010

Multiple comparison procedures for analysis of ranked data are available in tabular form for quick determination of significance. It was determined that the method used by Basker and Newell to determine critical values was overly conservative. Those values are useful for determining the overall significance of the model. Additional multiple comparison tables of critical values are presented for determining the rank significance of all samples within the set. Both sets of tables are included.
Influence of Different Factors on Firmness and Color Evolution During the Storage of Persimmon cv. ‘Rojo Brillante’
Authors: Salvador Alejandra , Arnal Lucíaa , Carot Jose M. , Carvalho Catarina P. , Jabaloyes José M.
Published: August 2010

‘Rojo Brillante’ persimmons were harvested in 2 different dates, early and late, and then submitted to 1‐methylcyclopropene (1‐MCP) treatment (500 nL/L) before stored at 1 or 15 °C up to 50 or 30 d, respectively. The influence of harvest date, 1‐MCP treatment, orchard, storage time, and temperature on firmness loss and color evolution during storage of ‘Rojo Brillante’ persimmon was studied. Statistical models that allowed the prediction of these 2 quality parameters during the storage, as well as the modeling of the behavior of both of them, were also evaluated. The softening, as a consequence of chilling sensitiveness when stored at 1 °C, was more accentuated in the early harvested fruit. In storage at 15 °C, also, the firmness loss was faster in fruit harvested earlier. 1‐MCP treatment drastically reduced chilling injury (CI) symptoms at 1 °C and retarded firmness loss at 15 °C, both of these effects being dependent on harvest date. The model presented to study the firmness and color relationship offers an important tool to predict firmness from fruit color measurements.
Ascorbic Acid Retention, Microbial Growth, and Sensory Acceptability of Lettuce Leaves Subjected to Mild Heat Shocks
Authors: Moreira Maríaa del R. , Ponce Alejandra G. , Del Valle Carlos E. , Roura Sara I.
Published: August 2010

Heat shocks not only produced a reduction in the initial content of ascorbic acid but also affected the rate of degradation of ascorbic acid during refrigerated storage. Samples treated at higher temperatures presented faster rates of degradation. The heat shocks produced an initial reduction in the counts of mesophilic aerobic microorganisms, with greater reductions associated with the higher shock temperatures. However, high shock temperatures promoted faster microbial growths during storage, probably due to the liberation of nutrients by the disruption of membrane barriers. The sensory attributes of lettuce leaves subjected to heat shocks presented mixed results. Thermal treatments affected the enzymatic activity, reducing browning phenomena, but also caused deleterious effects on surface color and texture of lettuce leaves. Heat shocks of 50°C could be useful for short‐term preservation of minimally processed lettuce, where the high rate of metabolic processes cause great deterioration of fresh products.
Evaluation of Shelf Life of Superchilled Cod (Gadus morhua) Fillets and the Influence of Temperature Fluctuations During Storage on Microbial and Chemical Quality Indicators
Authors: Olafsdottir Gudrun , Lauzon Hélégne L. , Martinsdóttir Emilíaa , Oehlenschláuger Joerg , Kristbergsson Kristberg
Published: August 2010

Quality changes of aerobically packed cod fillets stored under superchilling and abusive temperature conditions were characterized by the growth of specific spoilage organisms (SSO) and the production of microbial metabolites measured by an electronic nose along with traditional sensory and chemical analysis (total volatile basic nitrogen [TVB‐N], pH). A new process based on quick contact freezing and cold air blasting was used to achieve superchilling of fillets before chilled (0.5 °C) or superchilled (‐1.5 °C) storage. Photobacterium phosphoreum dominated under temperature abusive conditions coinciding with high levels of TVB‐N and increased electronic nose responses indicating increased levels of alcohols and aldehydes at sensory rejection. Dominating growth of Pseudomonas spp. in 1 batch was associated with the origin, the catching method, and the cooling conditions during processing. The superchilling process followed by superchilled storage (‐1.5 °C) extended the sensory shelf life of the fillets for at least 3 d compared with traditional process, resulting in a total shelf life of 15 d. High content of TVB‐N was observed in superchilled fillets at sensory rejection. P. phosphoreum counts were lower under superchilling conditions (6.0 to 6.8 log colony‐forming units [CFU]/g), compared with the traditionally processed chilled fillets (7.2 log CFU/g). However, H2S‐producing bacteria appeared to grow steadily under superchilling conditions reaching counts as high as 7.6 log CFU/g at sensory rejection.
Noradrenergic Projections from the A1 Field to the Preoptic Area in the Brain of the Ewe and Fos Responses to Oestrogen in the A1 Cells
Authors: Rawson J. A. , Scott C. J. , Pereira A. , Jakubowska A. , Clarke I. J.
Published: August 2010

Previous studies have shown that there is a population of noradrenergic cells in the caudal A1 field of the brainstem of the ewe that contain oestrogen receptors and project to the preoptic area, where gonadotrophin releasing hormone (GnRH) neurones are located. There are some discrepancies in the literature regarding the extent of this projection and the location of the cells in the A1 region. The issue has been a focus of attention because the positive feedback response to oestrogen that causes the ovulatory GnRH/luteinizing hormone surge may originate from this brainstem region. The aim of the present study was to determine the extent of the projections to the preoptic area and to determine whether the caudal A1 cells are activated by oestrogen. Eleven ovariectomized ewes received an injection of the retrograde tracer FluoroGold into the preoptic hypothalamus and four of these also received an i.m. injection of oestrogen 2 h before tissue collection. A further three sheep received i.m. oil injections to act as controls for those receiving oestrogen. Dopamine‐β‐hydroxylase (DBH)‐positive, retrogradely labelled cells were found within the A1 field in sheep that received preoptic FluoroGold injections. Cells in the vicinity of the A2 and A6 fields, that were retrogradely labelled with FluoroGold, were not DBH‐positive. Thus, cells in the A1 field provide a direct noradrenergic projection to the preoptic area and may be involved in the control of the secretion of GnRH in this species. Cells that project to the preoptic hypothalamus from more rostrally located areas of the brainstem are not noradrenergic. In the animals that received oestrogen, double‐labelling immunohistochemistry was performed throughout the A1 field for FluoroGold, DBH and Fos. DBH cells of the A1 field expressed Fos only in the oestrogen‐treated animals and not in the oil‐treated animals. There was a decline in the number of DBH cells that were retrogradely labelled from the caudal region of A1 towards obex. There was a similar gradient in the number of cells that were double‐labelled for Fos and FluoroGold. We conclude that there is a population of noradrenergic cells in the caudal A1 field that project to the preoptic area; this is a larger group of cells than previously reported. Oestrogen elicits an acute Fos response in these cells, which may be involved in the time‐delayed positive feedback response on GnRH cells. The caudal‐to‐rostral gradient in the labelling with FluoroGold and Fos in DBH‐positive cells is similar to that seen previously for oestrogen receptor in DBH‐positive cells in the A1 field.
Excitotoxic Lesions of the Medial Amygdala Differentially Disrupt Prolactin Secretory Responses in Cycling and Mated Female Rats
Authors: Polston E. K. , Erskine M. S.
Published: August 2010

This study examined the role of the posterodorsal medial amygdala (MePD) in the control of prolactin secretion in gonadally intact female rats 20 min after mating, during the oestrous cycle, and during early pregnancy/pseudopregnancy (P/PSP). Cycling females received bilateral infusions of an excitotoxic dose of N‐methyl‐d‐aspartate (NMDA) or vehicle into the MePD. Two to 4 weeks later, they were surgically implanted with intra‐atrial catheters for repeated blood sampling and were mated on the evening of proestrus until receiving 5, 10, 15 or 20 intromissions or 15 mounts‐without‐intromission (MO) from males. The percentages of rats becoming P/PSP increased as a function of numbers of intromissions received. All groups receiving intromissions showed similar approximately four‐fold increases in plasma prolactin concentrations 20 min after mating, while MO rats showed no increase at this time. There was no effect of NMDA lesion on this acute secretory response. Among rats that continued cycling, bilateral MePD lesion completely abolished the diurnal preovulatory prolactin surge, while incomplete and sham lesions did not. In rats that subsequently became P/PSP, bilateral lesion of the MePD resulted in dampening of prolactin concentrations at all sampling times 6–7 days after mating, while incomplete or sham lesions did not alter prolactin secretion at these times. These results demonstrate that the MePD is selectively important for the secretion of prolactin on the afternoon of proestrus and that this structure may also modulate prolactin release in P/PSP rats. Activity within MePD neurones does not appear to be required for the acute prolactin response to vaginocervical stimulation which occurs within minutes after mating.
Prenatal Stress, Glucocorticoids and the Programming of the Brain
Authors: Welberg L. A. M. , Seckl J. R.
Published: August 2010

A large body of human epidemiological data, as well as experimental studies, suggest that environmental factors operating early in life potently affect developing systems, permanently altering structure and function throughout life. This process with its persistent organizational effects has been called ‘programming’. The brain is a key target for such effects. This review focuses on the effects of adverse early environments, notably exposure to stress or glucocorticoids, upon subsequent adult hypothalamus‐pituitary‐adrenal axis activity, behaviour and cognition. We discuss the effects observed, the proposed underlying molecular and cellular mechanisms and the consequences for pathophysiology. The data suggest that key targets for programming include glucocorticoid receptor gene expression and the corticotrophin‐releasing hormone system. Increasing evidence for analogous processes in humans is also reviewed. Early life programming of neuroendocrine systems and behaviour by stress and exogenous or endogenous glucocorticoids appears to be a fundamental process underpinning common disorders. Approaches to minimize or reverse the consequences of such early life events may have therapeutic importance.
Effects of Glucocorticoids on Adrenal Chromaffin Cells
Authors: Hodel A.
Published: August 2010

The mammalian adrenal gland consists of two anatomically distinct parts: an outer cortex that synthesizes steroids and a central medulla that contains catecholamine‐producing chromaffin cells. Although derived from different embryological origins, the two secretory tissues in the adult animal are functionally as well as structurally linked. Glucocorticoids, a class of steroid hormones produced by the cortex, exert a variety of effects on medullary chromaffin cells. They modulate the expression of specific genes via activation of glucocorticoid receptors that act as transcription factors and either up‐ or down‐regulate mRNA synthesis. The direct binding to and modulation of cation channels by glucocorticoids as well as the control of mRNA or protein stability are other proposed mechanisms of glucocorticoid action. The activity of phenylethanolamine N‐methyltransferase, the enzyme that converts noradrenaline into adrenaline, is stimulated by glucocorticoids, which causes the conversion of noradrenergic to adrenergic chromaffin cells. Other phenotypic manifestations of glucocorticoid action include the upregulation of catecholamine synthesis, storage, and secretion. Furthermore, glucocorticoids have been implicated in chromaffin cell differentiation. However, recent gene knockout experiments suggest that glucocorticoid signalling is required only for the acquisition of the adrenergic but not the noradrenergic phenotype.
Temporal Migration of Gonadotrophin‐Releasing Hormone‐1 Neurones is Modified in GAD67 Knockout Mice
Authors: Lee J. M. , Tiong J. , Maddox D. M. , Condie B. G. , Wray S.
Published: August 2010

Gonadotrophin‐releasing hormone (GnRH‐1) neurones reside in the forebrain and regulate gonadal function via the hypothalamic–pituitary–gonadal axis. Disruption of this axis results in reproductive dysfunction. During embryonic development, GnRH‐1 neurones migrate from the nasal pit through the nasal/forebrain junction (NFJ) into the developing brain. Prenatally γ‐aminobutyric acid (GABA) is excitatory and has been shown to play a role in nervous system development. Both in vivo and in vitro experiments suggest that GABA inhibits migration of GnRH‐1 neurones. The present study examines the migration of GnRH‐1 neurones in GAD67 knockout (KO) mice to further elucidate the role of GABA on GnRH‐1 neuronal development. Three stages were examined, embryonic day (E)12.5, E14.5 and E17.5. GnRH‐1 cell number and location were analysed by immunocytochemistry and in situ hybridisation histochemistry. The total number of GnRH‐1 immunopositive cells was similar between wild‐type (WT) and KO mice. However, significant differences were found in the overall distribution of GnRH‐1 immunopositive cells in GAD67 KO compared to WT mice at all stages. Subsequent analysis by area revealed differences occurred at the NFJ with an increase in GnRH‐1 cells in GAD67 KO at E14.5 and a decrease in GnRH‐1 cells in GAD67 KO at E17.5. Comparable counts for cells expressing GnRH‐1 transcript and protein were obtained. These data indicate that attenuated levels of GABA accelerate GnRH‐1 cell migration in nasal areas as well as movement of GnRH‐1 cells into the central nervous system at the NFJ.
The Effects of Galanin‐Like Peptide on Energy Balance, Body Temperature and Brain Activity in the Mouse and Rat Are Independent of the GALR2/3 Receptor
Authors: Man P.‐S. , Lawrence C. B.
Published: August 2010

Galanin‐like peptide (GALP) is a neuropeptide that is thought to act on the galanin receptors GALR1, GALR2 and GALR3. In rats, i.c.v. injection of GALP has dichotomous actions on energy balance, stimulating feeding over the first hour, but reducing food intake and body weight at 24 h, as well as causing an increase in core body temperature. In mice, GALP only induces an anorexic action, and its effects on core body temperature are unknown. One aim of the present study was to determine the effects of GALP on core body temperature in mice. Intracerebroventricular injection of GALP into conscious mice had no effect on feeding over 1 h, but caused a significant reduction in food intake and body weight at 24 h. It also caused an immediate drop in core body temperature, which was followed by an increase in body temperature. To understand these different effects of GALP on energy balance in mice compared to rats, and to determine the involvement of GALR2 and GALR3, immunohistochemistry was performed to localise c‐Fos, a marker of cell activation. Intracerebroventricular injection of GALP induced c‐Fos expression in the parenchyma surrounding the ventricles, the ventricular ependymal cells and the meninges in mice and rats. GALP also induced c‐Fos expression in the supraoptic nucleus, dorsomedial hypothalamic nucleus, lateral hypothalamus and nucleus tractus solitarius in rats but not in mice. Central administration of a GALR2/3 agonist in rats did not induce c‐Fos in any of the brain regions that expressed this protein after GALP injection, and had no effect on food intake, body weight and body temperature in rats or mice. These data suggest that GALP induces differential effects on energy balance and brain activity in mice compared to rats, which are unlikely to be due to activation of the GALR2 or GALR3 receptor.
Presence of Corticotrophin‐Releasing Factor and /or Tyrosine Hydroxylase in Cells of a Neural Brain‐Testicular Pathway That are Labelled by a Transganglionic Tracer
Authors: James P. , Rivier C. , Lee S.
Published: August 2010

Our laboratory has shown that male testosterone levels are not solely controlled by the release of hypothalamic gonadotrophin‐releasing hormone and pituitary luteinising hormone, but are also regulated by a multisynaptic pathway connecting the brain and the testis that interferes with the testosterone response to gonadotrophins. This pathway, which is independent of the pituitary gland, is activated by an i.c.v. injection of either the stress‐related peptide corticotrophin‐releasing factor (CRF) or of β‐adrenoceptor agonists, both of which alter androgen release and decrease levels of the peripheral‐type benzodiazepine receptor and the steroidogenic acute regulatory protein within Leydig cells. Our original studies used the retrograde transganglionic tracer pseudorabies virus (PRV) to map progression of the virus from the testes to upper brain levels. The present study aimed to extend this work by identifying the regions where CRF and catecholamine neurones represented components of the stress‐activated, brain–testicular pathway that prevents testosterone increases. To this end, anaesthetised adult male rats received an intra‐testicular injection of PRV. Using immunofluorescence, we identified co‐labelling of PRV and either CRF or tyrosine hydroxylase (TH), the enzyme responsible for biogenic amine synthesis. Co‐labelling of PRV and CRF was found in the bed nucleus of the stria terminalis, the paraventricular nucleus of the hypothalamus (PVN) and the central amygdala. Co‐labelling of PRV and TH was found in the PVN, substantia nigra, A7/Kölliker‐Fuse area, area of A5, locus coeruleus, nucleus of solitary tract, area of C3, area of C2 and the area of C1/A1. These results indicate that most cell groups of the ventral noradrenergic pathway have neurones that are a part of the brain–testicular pathway. This suggests that the stress hormones CRF and catecholamines may act as neurotransmitters that signal the pathway to inhibit increases in plasma testosterone levels.
Chronic Osmotic Stimuli Increase Salusin‐β‐Like Immunoreactivity in the Rat Hypothalamo‐Neurohypophyseal System: Possible Involvement of Salusin‐β on [Ca2+]i Increase and Neurohypophyseal Hormone Release from the Axon Terminals
Authors: Saito T. , Dayanithi G. , Saito J. , Onaka T. , Urabe T. , Watanabe T. X. , Hashimoto H. , Yokoyama T. , Fujihara H. , Yokota A. , Nishizawa S. , Hirata Y. , Ueta Y.
Published: August 2010

Salusin‐α and ‐β were recently discovered as bioactive endogenous peptides. In the present study, we investigated the effects of chronic osmotic stimuli on salusin‐β‐like immunoreactivity (LI) in the rat hypothalamo‐neurohypophyseal system. We examined the effects of salusin‐β on synaptic inputs to the rat magnocellular neurosecretory cells (MNCs) of the supraoptic nucleus (SON) and neurohypophyseal hormone release from both freshly dissociated SONs and neurohypophyses in rats. Immunohistochemical studies revealed that salusin‐β‐LI neurones and fibres were markedly increased in the SON and the magnocellular division of the paraventricular nucleus after chronic osmotic stimuli resulting from salt loading for 5 days and dehydration for 3 days. Salusin‐β‐LI fibres and varicosities in the internal zone of the median eminence and the neurohypophysis were also increased after osmotic stimuli. Whole‐cell patch‐clamp recordings from rat SON slice preparations showed that salusin‐β did not cause significant changes in the excitatory and inhibitory postsynaptic currents of the MNCs. In vitro hormone release studies showed that salusin‐β evoked both arginine vasopressin (AVP) and oxytocin release from the neurohypophysis, but not the SON. In our hands, in the neurohypophysis, a significant release of AVP and oxytocin was observed only at concentrations from 100 nm and above of salusin‐β. Low concentrations below 100 nm were ineffective both on AVP and oxytocin release. We also measured intracellular calcium ([Ca2+]i) increase induced by salusin‐β on freshly‐isolated single nerve terminals from the neurohypophysis devoid of pars intermedia. Furthermore, this salusin‐β‐induced [Ca2+]i increase was blocked in the presence of high voltage activated Ca2+channel blockers. Our results suggest that salusin‐β may be involved in the regulation of body fluid balance by stimulating neurohypophyseal hormone release from nerve endings by an autocrine/paracrine mechanism.
Oestradiol Rapidly Enhances Spontaneous Glycinergic Synaptic Inhibition of Hypoglossal Motoneurones
Authors: Chesnoy‐Marchais D. , Meillerais A.
Published: August 2010

Whereas oestradiol is well‐known to facilitate excitatory glutamatergic synaptic transmission, its effects on fast inhibitory neurotransmission are not as well established. Possible acute modulation of the spontaneous glycinergic synaptic activity by oestradiol was investigated in voltage‐clamped hypoglossal motoneurones by whole‐cell patch‐clamp recording in rat brainstem slices. The spontaneous glycinergic synaptic activity was continuously recorded in each neurone under control conditions, during 12–20 min of perfusion with 17β‐oestradiol and during washing. When oestradiol was diluted in ethanol, the control solution contained the same amount of ethanol. At 100 nm, oestradiol markedly increased the frequency of the total spontaneous glycinergic activity. Similar experiments were performed after blockade of action potentials by tetrodotoxin, aiming to isolate miniature glycinergic synaptic currents. Oestradiol increased the frequency of glycinergic miniatures in most slices, in some cases within less than 1 min. In some slices, oestradiol also favoured the occurrence of glycinergic miniatures of large amplitude. These effects were slowly reversible during washing. At 1 nm, oestradiol still increased the frequency of glycinergic miniatures. The results were confirmed in the absence of ethanol by using water‐soluble cyclodextrin‐encapsulated oestradiol. In these experiments, the control solution contained the same amount of (2‐hydroxypropyl)‐β‐cyclodextrin as the oestradiol‐containing solution. In addition, prolonged control recordings were performed without applying oestradiol to check the stability of the glycinergic synaptic activity during prolonged whole‐cell recordings. The results show, for the first time, that, within a few minutes, oestradiol can enhance the spontaneous synaptic release of a major inhibitory transmitter, glycine.
Differential Kinetics of Oxytocin and Vasopressin Heteronuclear RNA Expression in the Rat Supraoptic Nucleus in Response to Chronic Salt Loading In vivo
Authors: Yue C. , Mutsuga N. , Sugimura Y. , Verbalis J. , Gainer H.
Published: August 2010

Previous studies have shown that the secretion of oxytocin and vasopressin from the posterior pituitary always accompanies systemic hyperosmotic stimuli in rats, and that oxytocin and vasopressin mRNAs consistently increase in response to prolonged hyperosmotic stimuli. Hence, it has been widely interpreted that oxytocin and vasopressin secretion and gene expression are closely coupled. In the present study, we used both vasopressin and oxytocin intron‐ specific probes to measure vasopressin and oxytocin heteronuclear RNA (hnRNA) levels, respectively, by in situ hybridisation in the rat supraoptic nucleus (SON) in conjunction with radioimmunoassays of vasopressin and oxytocin peptide levels in plasma and in the posterior pituitary in normally hydrated rats and after 1–5 days of salt loading. Increased oxytocin secretion in response to hyperosmotic stimuli exceeded vasopressin secretion at every time point studied. Vasopressin hnRNA in the SON increased to near maximal levels within minutes after the hyperosmotic stimulus, and was maintained throughout all 5 days of salt loading. By contrast, oxytocin hnRNA did not significantly change from control levels until approximately 2 days after hyperosmotic stimulation, and was not maximal until 3 days. In summary, increases in oxytocin gene transcription in response to osmotic stimuli are dramatically delayed compared to increases in vasopressin gene transcription under the same conditions. These data indicate that oxytocin gene transcription is not as closely correlated with pituitary peptide secretion as is vasopressin gene transcription, and suggests that there is a fundamental difference in excitation–secretion–transcription coupling mechanisms that regulate these two closely related genes in the rat magnocellular neurones in the SON.
FACTORS THAT INFLUENCE ACYL PROLINE CLEAVAGE BY SODIUM IN LIQUID AMMONIA
Authors: Marglin Arnold
Published: August 2010

The reductive cleavage of aminoacyl proline bonds by sodium in liquid ammonia was compared by a simple chromatographic technic for various protected and unprotected analogs of the C‐terminal tetrapeptide of the insulin B‐chain, ‐Thr‐Pro‐Lys‐Ala‐OH. The literature suggests that the Thr‐Pro bond in this peptide is especially sensitive to Na‐NN 3, compared to various other acyl proline bonds. The present study shows that this is true regardless of whether the sidechains, the α‐amino, and the α‐carboxyl groups are protected or free when they are introduced into liquid ammonia; there is no difference in the amount of reductive Thr‐Pro cleavage despite the different numbers of protons released into liquid ammonia by the functional groups of the residues surrounding the Thr‐Pro bond. The C‐terminal tetrapeptide and its blocked derivatives, prepared by solid phase synthesis, were reduced by Na‐NH 3 to the same extent as similarly synthesized B‐chains and natural B‐chain. Thr‐Pro cleavage could be minimized by sharply limiting the amount of sodium and the time of exposure of the peptide to it. The results are therefore useful in planning synthetic approaches to the B‐chain.

The Ser‐Pro bond shares the lability of the Thr‐Pro bond to Na‐NH 3 reduction, whereas the Val‐Pro bond is only half as labile.
SOME IMMUNOCHEMICAL RELATIONSHIPS OF Aeromonas AMINOPEPTIDASE
Authors: Miller Joyce M. , Prescott J. M.
Published: August 2010

Evidence for structural relationships between the aminopeptidase of Aeromonas proteolytica and several proteolytic enzymes, including two other aminopeptidases, was investigated by means of immunochemical techniques. The activity of Aeromonas aminopeptidase was strongly inhibited by its homologous antiserum (anti‐AAP), which also diminished the activity of the endopeptidase of Aeromonas proteolytica, although substantially higher concentrations were required for the latter. In contrast, the aminopeptidase of Bacillus licheniformis was stimulated by incubation with anti‐AAP, as were the activities of two types of Bacillus subtilis alkaline proteases. The activity of swine kidney leucine aminopeptidase and the aminopeptidase activity in pronase were unaffected by anti‐AAP. The only evolutionary relationship suggested by the inhibitory and stimulatory reactions was that between the endopeptidase and the aminopeptidase of Aeromonas proteolytica.
FLUORESCENCE STUDIES OF THE BACTERIAL PROTEASE E‐30‐III
Authors: Jori Giulio , Genov Nicolay
Published: August 2010

The fluorescence emission of the bacterial protease E‐30‐III, irradiated with 290 nm light, is exclusively due to the tryptophyl residues, which appear to be located in a rather polar environment. One indole side chain, which is fully exposed to the aqueous solvent, gives a minor contribution to the overall emission of the protein. On the other hand, the two strongly emitting indole systems appear to be contained in internal regions having a relatively high dielectric constant; fluorescence quenching studies demonstrate that the efficiency of the fluorescence emission by the two residues is about the same. In particular, one tryptophyl side chain must be spatially adjacent to a glutamyl or aspartyl residue. Exposure of the protein to 280 nm and 290 nm radiation reveals the occurrence of an efficient energy transfer from tyrosinie to tryptophan in the neutral pH region and from tryptophanie to tyrosinate in alkaline solutions; the latter process parallels the ionization of the phenolic side chains, as determined by spectrophotometric titrations. In acid solutions, the electronic energy transfer among aromatic residues is greatly diminished, and clearly resolved emission spectra from the tyrosyl and tryptophyl residues are observed.
THEORETICAL DETERMINATION OF THERMODYNAMIC PARAMETERS FOR INCORPORATION OF AMINO ACID RESIDUES IN α–HELIX OF POLY–L–ALANINE. CALCULATION OF PARAMETERS FOR LEUCINE AND ASPARTIC ACID
Authors: Lipkind G. M. , Popov E. M.
Published: August 2010

A semiempirical method has been suggested for calculating the parameter s of the phenomenological theory of helix‐random coil transition proposed by Zimm & Bragg. The s parameters for amino acid residues of leucine and aspartic acid have been determined. The results of the calculation are in qualitative agreement with the experiment.
THEORETICAL CONFORMATIONAL ANALYSIS OF METHYLAMIDES OF N–ACETYL–L–SERINE AND N–ACETYL–L–ASPARAGINE
Authors: Lipkind G. M. , Arkhipova S. F. , Popov E. M.
Published: August 2010

Theoretical analysis of conformations of methylamides of N‐acetyl‐L‐serine and N‐acetyl‐L‐asparagine was carried out proceeding from a mechanical molecular model. The important role of hydrogen bonds between the side chain and the backbone in stabilizing the most favourable forms was shown. An evaluation was made of the mobility of the side chain for different conformations of the backbone by calculating the statistical sums. Free energy was shown to have a minimum for the forms of the B type. The agreement between the results of calculating a model peptide and the conformational distribution of Asn and Ser residues in proteins is discussed.
STUDIES ON SILK FIBROIN. III. GEL FILTRATION STUDY OF FIBROINS
Authors: Pandit M. W. , Sagar A. J. , Rao M. S. Narasinga
Published: August 2010

Silk fibroin samples obtained by extraction of silk fibre with boiling, Na2CO3 solution for different intervals of time were examined in 6M guanidine hydrochloride solution by gel filtration on agarose.

All the samples studied were heterogeneous. The weight‐average molecular weight of the samples estimated by gel filtration method was lower than that obtained by the Archibald ultracentrifuge method in 0.1 M KNO3 solution.

This discrepancy was observed to be due to the dissociating effect of 6 M guanidine hydrochloride.

Sodium dodecyl sulfate and β‐mercaptoethanol also caused dissociation.

The thermal degradation of silk fibroin in Na2CO3 solution followed a first order reaction kinetics.

Electrophoresis of the fibroins on polyacrylamide gels could not be performed since the protein remained at the top of the gel either due to precipitation of the protein or because of interaction with the gel. The experiments with buffer containing 6 M urea or 0.1% SDS also failed.
ADRENODOXIN REDUCTASE, THE FLAVOPROTEIN COMPONENT OF ADRENAL MITOCHONDRIAL STEROID HYDROXYLASES:
Authors: Wickramasinghe Rohan H.
Published: August 2010

The activity of purified bovine adrenodoxin reductase was studied. The activity of the enzyme in reducing 2,6,‐dichlorophenolindophenol was maximal at about pH 6.5. The enzyme activity was affected by the ionic strength of the medium.

Low concentrations of the cofactor FAD restored much of the activity of enzyme preparations which reduced dichlorophenolindophenol slowly. Higher concentrations of FAD inhibited both this reduction by adrenodoxin reductase and steroid hydroxylation by extracts of adrenal mitochondrial protein. These inhibitory effects may be the result of the reduction (with subsequent autoxidation under aerobic conditions) of FAD by NADPH in the presence of adrenodoxin reductase. The latter effect was demonstrated under anaerobic conditions.

Some possible reasons for and implications of the observations are discussed.
POLYHYDRIC ALCOHOLS: STUCTURE‐SUPPORTING SOLVENTS FOR POLYPEPTIDES AND PROTEINS
Authors: Toniolo C. , Bonora G. M. , Fontana A.
Published: August 2010

The most common ordered peptide conformations, i.e. right‐handed α‐helix, β‐structure, and triple‐helical collagen‐type conformation, are all supported by ethylene glycol, as determined by circular dichroism
SYNTHETIC PEPTIDES SPANNING THE ENTIRE SEQUENCE OF PORCINE PANCREATIC SECRETORY TRYPSIN INHIBITOR II (KAZAL)*
Authors: Rocchi Raniero , Benassi Carlo A. , Guarneri Mario , Guggi Augusto , Tomatis Roberto
Published: August 2010

The general strategy for the synthesis, by conventional procedure, of the entire sequence of porcine pancreatic secretory trypsin inhibitor II (Kazal) is discussed. Six suitably protected subunits, spanning the entire amino acid sequence of the inhibitor, have been synthetized and fully characterized.
A STUDY OF THE UNFOLDING OF THE INHIBITED SUBTILISIN IN GUANIDINE HYDROCHLORIDE
Authors: Contaxis C. C. , McBride‐Warren P. A. , Epand Richard M.
Published: August 2010

Inhibited subtilisin (Subtilisin Carlsberg; Subtilopeptidase A) is unfolded in the presence of 7 M guanidine hydrochloride. The unfolding reaches a maximum in approximately 6 min at 20°C at pH 8.0. This is demonstrated by an increase of the mean residue ellipticity at 222 nm from ‐8.02 times 103 to ‐1.72 times 103 deg. cm2/decimole. The unfolding is partially reversible and this reversibility is favoured by lower concentrations of enzyme. The fact that the refolding process is not complete may be attributed to either the demonstrated self association of the denatured enzyme or to interference of non‐covalently bound autolysis peptides.
STUDY BY PMR SPECTROSCOPY AND GEL CHROMATOGRAPHY OF THE UNFOLDING OF SUBSTITUTED KERATEINES IN 8 M UREA
Authors: Bradbury J. H. , Peters D. E.
Published: August 2010

Various S‐substituted derivatives of the reduced low sulphur and high sulphur proteins from wool have been prepared in which the substituted group is hydrogen, carboxymethyl, carboxyethyl, methyl, carbamidomethyl, cyanoethyl and aminoethyl. The proton magnetic resonance (PMR) spectra and gel filtration chromatography of these proteins have been examined in 8 M urea solution as a function of pH in order to determine conditions under which the proteins occur as random coils in solution with no evidence for the occurrence of non‐covalent interactions.

The PMR method described in an earlier paper (1) provides an easier and much more sensitive method for the observation of non‐covalent interactions in random coil proteins than does the measurement of elution volumes in gel chromatography. The results obtained by both methods are consistent and show that the widest range of pH for which unfolding occurs in 8 M urea is obtained with the S‐carboxymethyl, S‐carboxyethyl, S‐methyl and S‐carbamidomethyl derivatives.
PROPERTIES AND IMMUNOCHEMICAL REACTIVITIES OF CARBOXY‐MODIFIED HUMAN SERUM ALBUMIN
Authors: Funding Lars , Jacobsen Christian , Steensgaard Jens , Jensen Peter Jørn , Jelert Henning
Published: August 2010

Seven carboxy modified and four amino modified derivatives of human serum albumin have been prepared and studied by optical rotatory dispersion measurements, gel filtration, immunoelectrophoresis, immunodiffusion and by use of an ammonium sulphate technique. It is found that carboxy groups are of major importance for the maintenance of the structure and function of human serum albumin, and that carboxy modification has a much more profound effect than amino modification has to the same relative extent.
PURIFICATION AND HETEROGENEITY OF HUMAN KININOGEN.
Authors: Hamberg Ulla , Elg Peter , Nissinen Erkki , Stelwagen Patrick
Published: August 2010

Various methods of preparing human kininogen were investigated with an aim to limit the immunoreactive contaminant proteins to permit purification by immunosorption. A five‐step procedure is described giving 7.5% yield of highly purified kininogen (pharmacological purity 14–20) from pooled human plasma, and containing approximately 30% alpha‐2HS‐glycoprotein and 2.8% albumin. Alpha‐2HS could not be removed by polyacrylamide gel electrophoresis or isoelectric focusing in column.

Analysis of heterogeneity of kininogen after chromatography on DEAE‐Sephadex using various linear gradients and gel filtration on Sephadex G‐100 suggested that a minor component may be an aggregate, not included in the yield. It remains uncertain whether this component derives from an occasionally observed high molecular form of active kininogen in the primary purification steps in the 7–12 S sieve fractions from Sephadex G‐200, and excluded from further purification by pooling.

Purification with immunosorbents was investigated using batch operations with antibody specific polymers prepared with antisera insolubilized with ethylchloroformate. It was found that the adsorption‐desorption procedure was favourable for immunization purposes in producing highly specific immunologically pure kininogen. The kininogen obtained by this method or by the removal of contaminant alpha‐2HS and albumin with the corresponding antibody specific polymers gave similar heterogenous patterns by polyacrylamide gel electrophoresis, indicating a main band of kininogen and several faintly stained bands which responded only to anti‐kininogen. With 200 μg of the kininogen protein purified by immunosorption using monospecific antiserum the kininogen precipitation titre was 1:8 after 6–8 weeks in rabbits. With a polymer prepared with 4 ml anti‐kininogen serum (1:8) and incubated with 800 μg highly purified kininogen approximately half the protein was desorbed with 2 M and 3 M sodium iodide in the first adsorption‐desorption procedure.
GLYCOPROTEINS SECRETED BY SUBLINGUAL GLANDS OF THE ECHIDNA (TACHYGLOSSUS ACULEATUS)
Authors: Lew J. Y. , Heidelberger M. , Griffiths M.
Published: August 2010

The portion of echnida sublingual glycoproteins which could be solubilized was fractionated by electrophoresis in polyacrylamide gel and by filtration on a column of Sephadex G‐100. Analyses for carbohydrate and amino acid are given and are compared with those of the submaxillary mucins of cattle, dog, pig and sheep. The molar ratio of galactosamine to sialic acid was roughly 1:1 in the echidna fractions, the sialic acid was N‐acetyl‐neuraminic acid, and there was very little neutral sugar. Proline was relatively high in amount, and isoleucine, half‐cystine, methionine, leucine, tyrosine, and phenylalanine were absent or present to a very small extent. The material was weakly antigenic in the rabbit.
SOLID PHASE SYNTHESIS AND SOME PHARMACOLOGICAL PROPERTIES OF 8‐D‐HOMOLYSINE‐VASOPRESSIN AND 1‐DEAMINO‐8‐D‐HOMOLYSINE‐VASOPRESSIN
Authors: Lindeberg E. Gunnar G.
Published: August 2010

8‐DL‐Homolysine‐vasopressin and its 1‐deamino derivative were synthesized by the solid phase method. The desired D‐homolysine analogues were obtained by digestion of the mixtures with trypsin and isolation of the peptide components by ion‐exchange chromatography. In agreement with earlier observations on vasopressins containing α, ω‐diamino acids of D configuration the new analogues show very low pressor activities. However, the antidiuretic effects are surprisingly high, thus reversing the known activity trend and making the D‐homolysine analogues highly selective antidiuretic agents.
POLYPEPTIDE MODELS OF COLLAGEN. SYNTHESIS OF (PRO‐PRO‐β‐ALA)n
Authors: Rapaka Rao S. , Bhatnagar Rajendra S.
Published: August 2010

The sequential copolymer (Pro‐Pro‐β‐Ala)n has been synthesized as a model for collagen. Preliminary studies indicate that the polymer may bear conformational resemblance to collagen.