bluuebunny/crossref_metadata_2025 huggingface dataset:
Use of Electrolyzed Oxidizing Water for Quality Improvement of Frozen Shrimp
Authors: Loi‐Braden Min Hui , Huang Tung‐Shi , Kim Jang‐H , Wei Cheng‐i , Weese Jean
Published: August 2010

The bactericidal effect of electrolyzed oxidizing (EO) water was evaluated on Escherichia coli O157:H7‐inoculated and Salmonella‐inoculated shrimp. The shrimp were inoculated on day 0 and stored frozen at ‐20°C. Bacterial enumeration was done on days 0, 24, 49, and 119 of frozen storage. Acidic EO water at 40 ppm free available chlorine was as effective as aqueous chlorine of the same concentration and was significantly more effective (P < 0.05) than tap water in reducing pathogen load on the inoculated shrimp. Further reduction of pathogen numbers was observed after each frozen storage period. Prewashing with alkaline EO water did not enhance the bactericidal activity of the acidic EO water on the shrimp. The washed acidic EO water of the inoculated shrimp had a nondetectable bacterial population compared with treated aqueous chlorine, alkaline EO water, and tap water. Non‐inoculated shrimp subjected to similar treatments were served cooked or uncooked to a minimum of 10 experienced panelists for sensory evaluation on days 0, 24, 49, and 119 of frozen storage. The cooked shrimp were evaluated for the presence of off‐odor, juiciness, tenderness, shrimpy flavor, aftertaste, and overall acceptability; whereas the raw shrimp were evaluated for color, firmness, presence of off‐odors, melanosis, and overall acceptability. Raw shrimp thawed from each frozen storage period were stored at refrigeration temperature (4 °C) for 3 d to observe for melanosis. No difference of sensory attributes was detected among the various treatment groups. Therefore, acidic EO water can be used as an effective disinfectant to replace aqueous chlorine for thawing shrimp blocks.
Advances in Seed Protein Research: A Perspective on Seed Allergens
Authors: Sathe Shridhar K. , Kshirsagar Harshal H. , Roux Kenneth H.
Published: August 2010

For various reasons, a considerable majority of the global population must rely on plant proteins obtained from cereals, legumes (including oilseeds), fruits, vegetables, and nuts to satisfy dietary protein needs and requirements. Edible seeds are a significant source of proteins in livestock production and in the manufacture of pet foods. In addition, edible seeds are important sources of carbohydrates (including dietary fiber), minerals, and certain vitamins in human and animal food supply. For various reasons, edible seeds are underutilized as human food. To fully exploit this renewable natural resource to its full potential, focused research efforts are warranted. With increased number of seed proteins being identified as food allergens, renewed interest in seed proteins is evident. In this article, a brief overview of seed proteins with special reference to their allergenicity is provided. An attempt is made to identify areas needing further research.
Level of Acrylamide Precursors Asparagine, Fructose, Glucose, and Sucrose in Potatoes Sold at Retail in Italy and in the United States
Authors: Vivanti Vittorio , Finotti Enrico , Friedman Mendel
Published: August 2010

The free amino acid asparagine and the reducing sugars glucose and fructose has been reported to serve as precursors for the heat‐induced formation of potentially toxic acrylamide in a variety of plant‐based food. To contribute to our knowledge about the levels of these precursors, we used ion‐exchange chromatography to measure free asparagine and high‐performance liquid chromatography (HPLC) to measure free glucose, fructose, and sucrose in 9 potato varieties sold at retail in Italy and in 22 varieties sold in the United States. Asparagine levels (in mmol/kg of fresh wt) ranged from 1.17 for the Agata potatoes to 57.65 Russet potatoes, a 49.3‐fold variation from lowest to highest value. The corresponding levels for fructose ranged from 1.73 (Fingerling Ozette) to 33.63 (Red), a 19.4‐fold variation from the lowest to the highest value. For glucose, the concentration ranged from 1.11 (Jelli) to 34.73 (Yukon Gold B) potatoes, a 31.3‐fold variation from lowest to highest value. The corresponding values for sucrose ranged from 1.16 (Fingerling Ozette) to 40.61 (Marabel) potatoes, a 35fold variation. The American potato varieties Kennebec, White, and Fingerling Ozette and the Italian potato varieties Agria, Merit, and Marabel had very low levels of both asparagine and reducing sugars. The results may enable consumers, restaurants, and processors to select commercial potatoes with low levels of acrylamide precursors for baking or frying.
High Dietary Vitamin E Affects Storage Stability of Frozen‐refrigerated Trout Fillets
Authors: Jittinandana Sitima , Kenney P. Brett , Slider Susan D. , Kamireddy Nalini , Hankins J.S.
Published: August 2010

Fillets were processed from trout fed a diet containing either 200 (low vitamin E [LVE] diet) or 5000 (high vitamin E [HVE] diet) mg a‐tocopheryl acetate/kg for 0, 4, and 9 wk. These fillets were evaluated fresh and after 6 mo of frozen storage. Frozen fillets were thawed and stored 3 d at 1 °C before analyses. Muscle α‐tocopherol of fish fed the HVE diet continuously increased through 9 wk of feeding. Reduced muscle α‐tocopherol and moisture, and increased muscle redness and fat were observed in frozen‐refrigerated fillets compared with fresh fillets. Thiobarbituric acid‐reactive substances were lower in frozen‐refrigerated fillets produced from fish fed the HVE diet. Proportion of unsaturated fatty acids and omega‐3 fatty acids increased as feeding duration increased from 0 to 9 wk.
Influence of Sulfonation on the Properties of Expanded Extrudates Containing 32% Whey Protein
Authors: Taylor David P. , Carpenter Charles E. , Walsh Marie K.
Published: August 2010

Whey protein concentrate (WPC) was treated with sodium sulfite to achieve 4 levels of disulfide bond sulfonation (0%, 31%, 54%, and 71% mole/mole). The WPCs were blended with cornstarch to a 32% (weigh/weight) protein content and extruded into an expanded product. Extrudates were collected at 160 °C and 170 °C and analyzed for physical (air cell diameter, expansion ratio, breaking strength, and density) and chemical (water adsorption index [WAI], water solubility index, moisture content, soluble protein, and carbohydrates) properties. The control and 54% sulfonated samples had larger expansion ratios and air cell diameters and smaller densities and breaking strengths than the 31% and 71% samples. Expansion increased at 170 °C in the sulfonated samples. The WAI was influenced by both sulfonation and temperature, whereas the other chemical properties (except moisture content) were influenced only by sulfonation level. Soluble protein and carbohydrate were highest in the control and 54% samples. The anomalous behavior of the 54% sample may have been the result of significant structural and functional changes of α‐lactalbumin that are predicted to occur at approximately 50% sulfonation. Many functional properties of the WPCs were measured and were significantly correlated to the extrudate properties, particularly those related to protein unfolding and flexibility The increased ability for the proteins to become unfolded during extrusion may have promoted protein‐starch interactions, which led to decreases in expansion and overall quality Disulfide bond content did influence the chemical and physical properties of an extruded‐expanded whey protein products.
Changes in Physical/chemical Composition and Histological Properties of Dorsal and Ventral Ordinary Muscles of Full‐cycle Cultured Pacific Bluefin Tuna, Thunnus orientalis, During Chilled Storage
Authors: Nakamura Yoshi‐Nori , Ando Masashi , Seoka Manabu , Kawasaki Ken‐ichi , Tsukamasa Yasuyuki
Published: August 2010

Using full‐cycle cultured Pacific bluefin tuna (BW: 33.5 ± 2.7 kg, cultured for about 33 mo), the physical/ chemical composition and histological properties of the cephalal parts of the dorsal ordinary muscles (DOMs) and ventral ordinary muscles (VOMs) were investigated during chilled storage at 4 °C for 69 h. VOM showed high fat content compared with DOM. The breaking strength of DOM increased up to 33 h but decreased thereafter, whereas VOM decreased gradually after 15 h. The pH and glycogen content of DOMs and VOMs decreased gradually after 9 h. The met‐myoglobin (met‐Mb)% and K‐value of DOMs and VOMs increased gradually during storage. Extension of intercellular spaces of DOM was observed by LM during storage. The abundant quantity of glycogen granules that accumulated around the myofibrils of DOM was confirmed by TEM to decrease during storage (especially, from 15 h).
Texture and Water Retention Improvement in High‐pressure Thermally Treated Scrambled Egg Patties
Authors: Juliano Pablo , Toldrág Monica , Koutchma Tatiana , Balasubramaniam V.M. , Clark Stephanie , Mathews Jason W. , Dunne C Patrick , Sadlerand George , Barbosa‐Cánovas Gustavo V.
Published: August 2010

Different methods for improving texture profile and water retention of scrambled egg patties after high‐pressure high‐temperature (HPHT) treatment were evaluated as part of a feasibility study for the development of shelf‐stable egg products. Four formulations, a basic one, 2 with xanthan gum, 1 with cheese, were compared after HPHT treatment by analyzing texture profile and degree of syneresis. The effects of water addition of 0% to 15%, 3 levels of vacuum packaging, 4 preheating rates, and 2 HPHT conditions (700 MPa/105 °C/5 min and 700 MPa/121 °C/3 min) on texture and water retention of egg patties were also compared for selected formulations. Patties reformulated with xanthan gum and cheese resulted in at least a 30% reduction in hardness, cohesiveness, and water loss. Use of low vacuum packaging in less porous patties modified with xanthan gum maintained original texture values after 700 MPa/105 °C/5 min. Addition of water into the defrosted structure increased water holding capacity and maintained hardness within its standard value after pressurization at 105 °C and 121 °C. Most texture descriptors and syneresis did not change significantly with preheating rates after HPHT treatment. Tested mechanisms for texture and water retention improvement of HPHT treated patties can contribute to meeting quality requirements not fulfilled by conventional thermal processing for the development of shelf‐stable scrambled egg products.
Development and Characterization of Edible Films from Cranberry Pomace Extracts
Authors: Park Su‐il , Zhao Yanyun
Published: August 2010

The feasibility of using cranberry pomace extract as a new film‐forming material was studied. Cranberry pomaces were extracted using hot water. Low methoxyl pectin (LMP) or high methoxyl pectin (HMP) at a concentration of 0.50% or 0.75% (w/w) and 0.25% (w/w) sorbitol or glycerol was incorporated into film‐forming solutions (FFSs) for improving film functionality. Proximate compositions of cranberry pomace and its extract were determined. The pH and total soluble solid content (SSC) of FFSs, physical and mechanical properties, water vapor permeability, and microstructure of dried films were analyzed. About 1.4% (w/w) of solids was obtained from cranberry pomace water extracts, of which about 93% was carbohydrate. Dried films had bright red color and strong cranberry flavor. Films plasticized with sorbitol were denser in matrix structure and had higher color intensity than those of glycerol plasticized films. In general, LMP and sorbitol incorporated films had higher tensile strength and lower elongation at break and lower water vapor permeability than other films. The higher (0.75%) pectin concentration resulted in increased tensile strength, but decreased elongation at break. Scanning electron microscopy images revealed that sorbitol added films had more regular and compact cross‐section structure than those of glycerol added films. This study demonstrated that it is feasible to create natural colorful and fruit flavor edible films from fruit pomace water extracts. Depending on specific applications of the films, targeted film functionality can be achieved by incorporating proper pectin type and concentration and plasticizer into pomace extracts.
Improving Microbial Growth Prediction by Product Unit Neural Networks
Authors: Hervás‐Martíanez Cesar , Garcíaa‐Gimeno Rosa M. , Martíanez‐Estudillo Alfonso C. , Martíanez‐Estudillo Francisco J. , Zurera‐Cosano Gonzalo
Published: August 2010

This article presents a new approach to the Artificial Neural Networks (ANN) modeling of bacterial growth; using Neural Network models based on Product Units (PUNN) instead of on sigmoidal units (multilayer perceptron type [MLP]) of kinetic parameters (lag‐time, growth rate, and maximum population density) of Leuconostoc mesenteroides and those factors affecting their growth such as storage temperature, pH, NaCl, and NaNO2 concentrations under anaerobic conditions. To enable the best degree of interpretability, a series of simple rules to simplify the expression of the model were set up. The new model PUNN was compared with Response Surface (RS) and MLP estimations developed previously. Standard Estimation Error of generalization (SEPG’) values obtained by PUNN were lower for lag‐time and growth rate but higher for maximum population density than MLP when validated against a new data set. In all cases, bias factors (Bf) and accuracy factors (Af) were close to unity, which indicates a good fit between the observations and predictions for the 3 models. In our study, PUNN and MLP models were more complex than the RS models, especially in the case of the growth rate parameter, but they described lower SEPG’. With this work we have attempted to propose a new approach to neural networks estimations for its application on predictive microbiology, searching for models with easier interpretation and with a great ability to fit the data on the boundaries of variables range. We consider that still there is a lot left to do but PUNN could be a very valuable instrument for mathematical modeling.
Inhibition of Listeria monocytogenes by Nisin Combined with Grape Seed Extract or Green Tea Extract in Soy Protein Film Coated on Turkey Frankfurters
Authors: Theivendran Sivarooban , Hettiarachchy Navam S. , Johnson Michael G.
Published: August 2010

The objective of this study was to evaluate the inhibitory effect of grape seed extract (GSE), green tea extract (GTE), nisin and their combinations (nisin with either GSE or GTE) againstListeria monocytogenes. The inhibitory effect of these natural compounds was evaluated in phosphate buffer solution (PBS) medium containing approximately 109colony‐forming units (CFU/mL) ofL. monocytogenes.The effectiveness of these compounds in a meat model system was evaluated by surface inoculation (approximately 106CFU/g) ofL. monocytogenesonto turkey frankfurters. The inoculated frankfurters were dipped into soy protein film‐forming solutions with and without the addition of antimicrobial agents (GSE 1% or GTE 1% or nisin 10000 IU or combinations). Samples were stored at either 4 °C or 10 °C. The inhibitory effects of edible coatings were evaluated on a weekly basis for 28 d. The greatest inhibitory effect was observed in the PBS medium containing GSE (1%) and nisin (10000 IU/mL), which caused a 9‐log cycle reduction ofL. monocytogenespopulation after 3 h incubation at 37 °C. In the meat system, theL. monocytogenespopulation (7.1 CFU/g) was decreased by more than 2 log cycle after 28 d at 4 °C and 10 °C, in the samples containing nisin (10000 IU) combined with either GSE (1%) or GTE (1%). This research has demonstrated that the use of an edible film coating containing both nisin and natural extracts is a promising means of controlling the growth and recontamination ofL. monocytogeneson ready‐to‐eat meat products.
Influence of Injection, Packaging, and Storage Conditions on the Quality of Beef and Bison Steaks
Authors: Pietrasik Zbigniew , Dhanda Jagvinder S. , Shand Phyllis J. , Pegg Ronald B.
Published: August 2010

The combined effects of injection, packaging (modified atmosphere packaging [MAP] with 70% O2/ 30% CO2 and vacuum packaging [VP]), storage temperature (‐1 °C and +4 °C), and storage time on the color, microbial and oxidative stability of beef and bison longissimus lumborum (LL) steaks were investigated. Beef LL steaks in MAP retained their bright red color longer than bison steaks. Bison steaks developed higher 2‐Thiobarbituric acid reactive substances (TBARS) during storage, and this might have influenced the resulting rapid loss of redness from the bloomed meat. Storage at ‐1 °C in MAP provided greater color stability and a longer storage life for both meat species studied. Injection of salt/phosphate had a beneficial effect on the color stability of steaks during retail display; however, this positive effect was more pronounced for bison steaks compared with those of beef. Steaks stored overnight under MAP before retail display maintained the highest a* values for up to 5 d compared with those stored under vacuum. MAP‐OV steaks generally maintained the highest OMB content for up to 5 d during retail display compared with those stored under vacuum. Nevertheless, OMB levels were significantly (P < 0.05) lower in bison steaks compared with those of beef irrespective of packaging treatments. Injected steaks and those stored at ‐1 °C had significantly (P < 0.05) higher OMB levels compared with non‐injected counterparts and those stored at +4 °C, respectively. MAP is an excellent option for short‐term storage due to its positive effects on meat color, but for longer storage, VP may be necessary. Storing meat under vacuum and then placing it under MAP just before retail display might be another option to increase shelf life.
Frozen Wild Blueberry‐Tofu‐Soymilk Desserts
Authors: Camire Mary Ellen , Dougherty Michael P. , Teh Yean‐Hoong
Published: August 2010

Both wild (lowbush) blueberries (Vaccinium angustifolium Ait.) and soybeans (Glycine max L.) possess a variety of antioxidants, and both foods appear to have multiple health benefits. Our objectives were to identify whether wild blueberry juice concentrate was more acceptable than puree in frozen desserts with a soy milk‐tofu base; to determine whether fat‐free products were as acceptable as those with 10% added fat; and to compare several levels of blueberry juice concentrate. Four frozen dessert formulations were prepared in duplicate from soy milk, silken tofu, sucrose, stabilizer, BJC or puree, soybean oil or polydextrose, sweetened dried blueberries, salt, and lemon juice. Samples were assayed for total anthocyanins, antioxidant activity using the DPPH method, color, overrun, and solids. Fifty‐five persons evaluated the samples using a 9‐point hedonic scale for color, flavor, texture, and overall acceptability. Samples containing blueberry juice concentrate were darker and less blue. Anthocyanin levels were highest in the puree sample and the fat‐free product with 7.8% blueberry juice concentrate. However, antioxidant activity was highest (28 Trolox equivalents per gram) in the samples made with soybean oil and 7.4% blueberry juice concentrate. The puree formulation received higher hedonic scores than did the low‐fat blueberry juice concentrate formulations. The puree formulation received overall acceptability scores of like very much or like extremely by 45% of the consumers. These findings may aid processors in defining potential formulations that combine 2 healthful food ingredients.
Effect of Modified Atmosphere Packaging and Soluble Gas Stabilization on the Shelf Life of Skinless Chicken Breast Fillets
Authors: Rotabakk Bjørn T. , Birkeland Sveinung , Jeksrud Willy K. , Sivertsvik Morten
Published: August 2010

The suitability of soluble gas stabilization (SGS) to dissolve CO2 into skinless chicken breast fillets before modified atmosphere (MA) packaging (MAP) was investigated. Head space gas composition (%), top web deflation (mm), muscle surface color (Minolta L*a*b*), pH, exudates in the packages (%), microbial characteristics, and off‐odor were assessed in the packaged fillets. Increased SGS treatment time (2 versus 12 h) before MA packaging increased the CO2 content in the packaged fillets and counteracted package collapse. High package filling degree (51.8%) (low gas to product volume ratio) gave significantly (P < 0.001) lower CO2 content in head space than normal filling degree (29.7%). Color, pH, and package exudates were not affected by SGS treatment. Aerobic plate count (APC), Enterbacteriaceae count (EC), and lactic acid bacteria (LAB) increased significantly (P < 0.001) at each sampling during storage (5, 11, 17, and 24 d). SGS treatment significantly (P < 0.015) decreased APC, EC, and Pseudomonas spp. counts (PC) compared with no SGS treatment. Filling degree did not have a significant effect on the investigated microbiological characteristics. Off‐odor scores correlated highest with EC (r2(adj)= 0.82). Fillets SGS treated in 12 h were the only one not rejected at off‐odor evaluation on day 24. The samples stored in air spoiled after 5 d. SGS treatment in combination with MAP can be used successfully on chicken breast fillets to improve the microbiological (APC, EC, and PC) and sensorial characteristics, and in addition reduce package collapse and possibly increase the filling degree.
Induction of Quinone Reductase, The Phase 2 Anticarcinogenic Marker Enzyme, in Hepa1c1c7 Cells by Radish Sprouts, Raphanus sativus L.
Authors: Lee Syng‐Ook , Lee In‐Seon
Published: August 2010

The activity of a methanol extract of radish sprouts for the induction of nicotinamide adenine dinucleotide (phosphate) NAD(P)H/quinone reductase (QR), which plays critical roles in protection against chemical carcinogens and other toxic xenobiotics, was examined in murine Hepa1c1c7 cells. The methanol extract induced QR activity in a dose‐dependent manner in the concentration range of 0.2 to 1.6 mg/mL with a maximum of a 3.5‐fold increase in induction. The induction of QR by the extract was regulated at the transcriptional level. Using a Western blotting analysis and Ah‐receptor‐defective mutant of Hepa1c1c7 cells (BPrc1 cells), the extracts at a concentration of 0.8 mg/mL or lower was found to be a monofunctional inducer and caused no elevation in cytochrome P‐450 level that may activate carcinogens. The dichloromethane (CH2Cl2) fraction of the extract showed the highest induction potency while the other fractions were less potent. These results indicate that radish sprouts can be regarded as a safe and promising new dietary source for decreasing the risk of developing cancer.
Effects of Low‐dose Electron Beam Irradiation on Respiration, Microbiology, Texture, Color, and Sensory Characteristics of Fresh‐cut Cantaloupe Stored in Modified‐atmosphere Packages
Authors: Boynton Bryan B. , Welt Bruce A. , Sims Charles A. , Balaban Murat O. , Brecht Jeffery K. , Marshall Maurice R.
Published: August 2010

Fresh‐cut cantaloupe was placed in modified‐atmosphere packages (4% oxygen, 10% carbon dioxide) and irradiated at 0 (control), 0.5, and 1.0 kGy. Irradiated samples had a lower and more stable rate of respiration than non‐irradiated samples over about 20 d. Total plate counts were higher (P < 0.05) in non‐irradiated control samples through day 11 (Trial 1) and for all dates tested (Trial 2). Color and texture remained stable for the duration of each study as measured by instruments and trained sensory panels. Sensory evaluation rated the 1.0‐kGy sample highest in “sweetness” and “cantaloupe flavor intensity” and lowest in “off‐flavor” after 17 (±3) d of storage. Low‐dose electron beam irradiation of fresh‐cut cantaloupe with modified‐atmosphere packaging offers promise as a method of extending shelf life.
Chronic Hypoosmolality Induces a Selective Decrease in Magnocellular Neurone Soma and Nuclear Size in the Rat Hypothalamic Supraoptic Nucleus
Authors: Zhang B. , Glasgow E. , Murase T. , Verbalis J. G. , Gainer H.
Published: August 2010

The magnocellular neurones of the hypothalamo‐neurohypophysial system (HNS) play a vital role in the maintenance of body homeostasis by regulating oxytocin (OT) and vasopressin (VP) secretion from the posterior pituitary. During hyperosmolality, OT and VP mRNA levels are known to increase by approximately two‐fold, whereas during chronic hypoosmolality, OT and VP mRNA levels decrease to approximately 10–20% of basal levels. In these studies, we evaluated changes in cell size associated with these physiological conditions. Cell and nuclear sizes of neurones in the supraoptic nucleus (SON), the nucleus of the lateral olfactory tract (LOT) and the medial habenular nucleus (MHB) were measured from neurones identified by in situ hybridization histochemistry for βIII‐tubulin mRNA, and measurements were made from OT and AVP magnocellular neurones in the SON after phenotypic identification by immunohistochemistry. Under hypoosmolar conditions, the cell and nuclear sizes of OT and VP magnocellular neurones decreased to approximately 60% of basal values, whereas cell and nuclear sizes of OT and VP neurones in hyperosmolar rats increased to approximately 170% of basal values. In contrast, neither hyperosmolality, nor hypoosmolality significantly affected cell and nuclear sizes in the LOT and MHB. These results confirm previous studies that showed that magnocellular neurones increase cell size in response to hyperosmolar conditions and, for the first time, demonstrate a marked decrease in cell size in the SON in response to chronic hypoosmolar conditions. These dramatic changes in cell and nuclear size directly parallel changes in OT and VP gene expression in the magnocellular neurones of the SON and, consequently, are consistent with the pronounced bidirectional changes in gene expression and cellular activity found during these osmotic perturbations. Our results therefore support the concept of global alterations in the synthetic activity of magnocellular OT and AVP neurones in response to extracellular osmolality.
Manipulating the In Vivo mRNA Expression Profile of FSHβ to Resemble that of LHβ Does Not Promote a Concomitant Increase in Intracellular Storage of Follicle‐Stimulating Hormone
Authors: Brown P. , McNeilly J. R. , Evans J. G. , Crawford G. M. , Walker M. , Christian H. C. , McNeilly A. S.
Published: August 2010

The β‐subunits of luteinizing hormone (LHβ) and follicle‐stimulating hormone (FSHβ) are differentially expressed, and this may contribute to the unique expression and storage patterns of LH and FSH. Therefore, to determine if the in vivo expression profile of FSHβ could be altered to that of LHβ, a truncated ovine FSHβ (oFSHβ) gene, which would encode a mRNA lacking the putative destabilizing 3′ untranslated region, was fused downstream of the ovine LHβ (oLHβ) promoter and expressed in transgenic mice. In two independent lines, line 16 and 17, we measured oFSHβ, mouse LHβ (mLHβ) and mouse FSHβ (mFSHβ) mRNA levels: (i) after castration in males; (ii) after administering inhibin to ovariectomized mice; and (iii) during the oestrous cycle. In each experiment, the expression profile of oFSHβ mRNA mimicked mLHβ and not mFSHβ mRNA. In addition, after actinomycin D treatment of pituitary cultures, while mFSHβ mRNA did decay, there was no measurable decay of the oFSHβ mRNA transcript. These differences increased total FSHβ steady‐state mRNA expression levels in male transgenics. However, there was no detectable increase in pituitary FSH by either radioimmunoassay or western blotting analysis of pituitary extracts. Subsequent analysis revealed that pituitary FSHβ in line 16 was heavily glycosylated; in contrast, pituitary FSHβ in line 17 was largely unmodified. These differences in post‐translational modification of the β‐subunit, and the lack of intracellular storage, contributed to increased plasma FSH levels and ovulation rate in line 16, but not line 17. In conclusion, the expression profile of oFSHβ mRNA was manipulated to mimic mLHβ mRNA and this increased FSHβ mRNA expression levels, but did not increase storage of FSH. This suggests that, regardless of the levels of synthesis, post‐translational sorting preferentially promotes FSH secretion from the pituitary.
Oestrogen‐Induced Changes in the Synaptology of the Monkey (Cercopithecus aethiops) Arcuate Nucleus During Gonadotropin Feedback
Authors: Zsarnovszky A. , Horvath T. L. , Garcia‐Segura L. M. , Horvath B. , Naftolin F.
Published: August 2010

To assess their role in the regulation of gonadotropin secretion in primates, we determined the number of synaptic connections on gondotropin releasing hormone (GnRH)‐ and non‐GnRH neurones of the arcuate nucleus of ovariectomized (OVX) and OVX plus oestradiol benzoate‐treated African green monkeys. After 24 h (day 1), 48 h (day 2) and 8 days (day 8), we performed immunostaining for GnRH. Using electron microscopy, synapses on GnRH‐ and randomly selected non‐GnRH neurones were counted and characterized according to the classification of Gray (symmetric/inhibitory or asymmetric/excitatory). Serum concentrations of oestradiol (OVX) needed to 232 pg/ml on day 1, 63 pg/ml on day 2 and 45 pg/ml on day 8. Concentrations of luteinizing hormone (LH) fell after ovariectomy to 9 µg/ml on day 1, surged to 93 µg/ml on day 2 and declined again by day 8. (a) Ten days after ovariectomy, there were no synapses on GnRH neurones, whereas non‐GnRH cells received substantial inhibitory innervation and moderate excitatory input. (b) On day 1, GnRH neurones had highest numbers of inhibitory synapses, while inhibitory synapses on non‐GnRH neurones decreased, whereas numbers of excitatory synapses remained relatively unchanged compared to OVX monkeys. (c) By day 2, synapses on GnRH neurones decreased, while synapses increased on non‐GnRH cells compared to day 1. (d) On day 8, the most pronounced alteration on GnRH cells was an elevated inhibitory input while non‐GnRH neurones received the fewest synapses compared to day 2. We conclude that during an oestrogen‐induced LH surge, synapses on GnRH‐ and mixed non‐GnRH neurones are differentially regulated. These findings suggest that oestrogen modulation of arcuate nucleus synapses may be important in the regulation of gonadotropin secretion in monkeys.
Leptin Deficiency Per Se Dictates Body Composition and Insulin Action in ob/ob Mice
Authors: Van Den Hoek A. M. , Teusink B. , Voshol P. J. , Havekes L. M. , Romijn J. A. , Pijl H.
Published: August 2010

Obese humans are often insulin‐ and leptin resistant. Since leptin can affect glucose metabolism, it is conceivable that a lack of leptin signal transduction contributes to insulin resistance. It remains unclear whether leptin affects glucose metabolism via peripheral and/or central mechanistic routes. In the present study, we aimed: (i) to determine the relative contributions of lack of leptin signal transduction and adiposity to insulin resistance and (ii) to establish the impact of central leptin action on glucose metabolism. To address the first point, ob/ob mice were subjected to severe calorie restriction, so that their body weight became similar to that of wild‐type mice. Insulin sensitivity was measured in obese ob/ob, lean (food restricted) ob/ob and lean, weight‐matched wild‐type mice. To address the second point, leptin (or vehicle) was i.c.v. infused to the lateral cerebral ventricle of ob/ob mice and insulin sensitivity was determined. Hyperinsulinaemic euglyceamic clamps were used to quantify insulin sensitivity. Food restriction barely affected body composition, although it profoundly curtailed body weight. Insulin suppressed hepatic glucose production (HGP) to a greater extent in lean ob/ob than in obese ob/ob mice, but its impact remained considerably less than in wild‐type mice (% suppression: 11.8 ± 8.9 versus 1.3 ± 1.1 versus 56.6 ± 13.0%/nmol, for lean, obese ob/ob and wild‐type mice, respectively; P < 0.05). The insulin‐mediated glucose disposal (GD) of lean ob/ob mice was also in between that of obese ob/ob and wild‐type mice (37.5 ± 21.4 versus 25.1 ± 14.6 versus 59.6 ± 17.3 μmol/min/kg/nmol of insulin, respectively; P < 0.05 wild‐type versus obese ob/ob mice). Leptin infusion acutely enhanced both hepatic insulin sensitivity (insulin‐induced inhibition of HGP) and insulin‐mediated GD (9.1 ± 2.4 versus 5.0 ± 2.7%/nmol of insulin, and 25.6 ± 5.6 versus 13.6 ± 4.8 μmol/min/kg/nmol of insulin, respectively; P < 0.05 for both comparisons) in ob/ob mice. Both a lack of leptin signals and adiposity may contribute to insulin resistance in obese individuals. Diminution of central leptin signalling can critically affect glucose metabolism in these individuals.
Daily Meal Timing is Not Necessary for Resetting the Main Circadian Clock by Calorie Restriction
Authors: Mendoza J. , Drevet K. , Pévet P. , Challet E.
Published: August 2010

In rodents, entrainment and/or resetting by feeding of the central circadian clock, the suprachiasmatic nucleus (SCN), is more efficient when food cues arise from a timed calorie restriction. Because timed calorie restriction is associated with a single meal each day at the same time, its resetting properties on the SCN possibly depend on a combination of meal time‐giving cues and hypocaloric conditions per se. To exclude any effect of daily meal timing in resetting by calorie restriction, the present study employed a model of ultradian feeding schedules, divided into six meals with different durations of food access (6 × 8‐min versus 6 × 12‐min meal schedule) every 4 h over the 24‐h cycle. The effects of such an ultradian calorie restriction were evaluated on the rhythms of wheel‐running activity (WRA) and body temperature (Tb) in rats. The results indicate that daily/circadian rhythms of WRA and Tb were shifted by a hypocaloric feeding distributed in six ultradian short meals (i.e. 6 × 8‐min meal schedule), showing both phase advances and delays. The magnitude of phase shifts was positively correlated with body weight loss and level of day‐time behavioural activity. By contrast, rats fed daily with six ultradian meals long enough (i.e. 6 × 12‐min meal schedule) to prevent body weight loss, showed only small, if any, phase shifts in WRA and Tb rhythms. The results obtained reveal the potency of calorie restriction to reset the SCN clock without synchronisation to daily meal timing, highlighting functional links between metabolism, calorie restriction and the circadian timing system.
SYNTHESIS OF PEPTIDE ANALOGS OF THE N‐TERMINAL EICOSAPEPTIDE SEQUENCE OF RIBONUCLEASE A.
Authors: Borin G. , Toniolo C. , Moroder L. , Marchiori F. , Rocchi R. , Scoffone E.
Published: August 2010

Synthesis of the S‐peptide analog in which the arginyl residue in position 10 and the histidyl residue in position 12 are simultaneously replaced by two ornithines is described. The stereochemical homogeneity of the [Orn 10, Orn 12]‐S‐peptide has been assessed by digestion with aminopeptidase M. The ability of the synthetic S‐peptide analog to bind and to activate S‐protein was tested, before and after guanidination, by exploring its capacity to compete with S‐peptide for S‐protein and to generate ribonuclease activity when recombined with S‐protein.

The binding capacity of the synthetic material has been also evaluated by differential spectroscopy. Both the examined products failed to activate S‐protein at a molar ratio as high as 500:1 with RNA, cytidine 2′, 3′‐cyclic phosphate, and cytidylyl (3′‐5′) cytidine as substrate. Moreover, inhibition studies and spectrophotometric measurements showed that the synthetic S‐peptide analog as well as its guanidinated derivative are also unable to bind to S‐protein. It seems that the histidyl residue in position 12 in the S‐peptide sequence, in addition to the critical role played in the catalytic function, should be also important in the association process between S‐peptide and S‐protein.
URINARY PROTEINS OF THE NORMAL RAT
Authors: Perassi Ruth , Martin Alejandro
Published: August 2010

The protein composition of normal male rat urine and the possible origin of its components were studied immunologically.

At least sixteen antigenic components were identified, eight of which showed immunological identity to serum proteins. These are: albumin, three alpha1 (alpha1B,alphas1C,and alphas1D), two alpha2, beta2c, and gamma globulin. These components seem to arise from the blood by glomerular filtration.

The other eight components did not show immunologic identity with serum proteins. Two components migrated in the rho zone, five or six in the alpha2 zone, and one in the beta zone.

The antigenic relationship between tissue‐like proteins in the urine, and proteins extracted from the kidney, urinary tract or related organ tissues, was also studied. Antiserum to whole rat urine absorbed with rat serum gave two precipitin lines with kidney extract, one with the ureter, one with the bladder, three with the prostate, three with the bulbo urethral glands, two with the mixture of testis, epididymis, and ductus deferens, and two with the mixture of seminal vesicle and coagulating glands. With this same antiserum some of the tissue extracts gave reactions of identity among themselves.
ALLOSTERIC MODELS FOR THE INTERACTION OF 2,3‐DIPHOSPHOGLYCERIC ACID WITH HEMOGLOBIN
Authors: Janssen Lambert H. M. , DE Bruin Simon H.
Published: August 2010

The capabilities of the two state model of Monod, Wyman and Changeux and the sequential model of Koshland, Némethy and Filmer to explain the influence of 2,3‐diphosphoglyceric acid on the oxygen‐binding properties of hemoglobin are compared. It appeared that, after introducing some modifications into the model of Koshland et at., the influence of 2,3‐diphosphoglyceric acid on the oxygen‐binding can better be described by this model than by the model of Monod et al. In addition, a method is presented, based entirely on oxygen‐binding data of tetrameric hemoglobin, by which the parameters of the two state model can be evaluated.
SYNTHESIS AND GROWTH‐PROMOTING ACTIVITY OF N α‐ACETYL‐HGH‐(95–136)*
Authors: Blake James , Li Choh Hao
Published: August 2010

An N α‐acetyl peptide with 42 amino acids corresponding to the amino acid sequence in residues 95–136 of the HGH molecule has been synthesized by the solid phase method. The synthetic product was found to possess some growth‐promoting activity as revealed by the rat tibia test.
THE PRIMARY STRUCTURES OF α AND β CHAINS OF ADULT HEMOGLOBIN OF THE JAPANESE MONKEY (Macata fuscata fuscata)
Authors: Matsuda Genji , Maita Tetsuo , Ota Hisahiro , Araya Aiko , Nakashim Yasutsugu , Ishii Umeko , Nakashima Masae
Published: August 2010

Amino acid sequence of the tryptic peptides from the α and β chains of adult hemoglobin of the Japanese monkey were analyzed by partial hydrolyses with enzymes, the DNP method, PTC method and others after the isolation and purification of these peptides. Furthermore, the primary structures of the α and β chains of adult hemoglobin from the Japanese monkey were obtained by homology between these results and those of human adult hemoglobins. These primary structures show a high similarity to the primary structures of the α and β chains of adult hemoglobins from the human and rhesus monkey.
PREPARATION OF SOME 2‐PHENYLISOPROPYLOXYCARBONYL AMINO ACIDS. EVALUATION OF THEIR PROPERTIES WITH PARTICULAR REFERENCE TO APPLICATION IN SOLID PHASE PEPTIDE SYNTHESIS
Authors: Sandberg Bengt E. B. , Ragnarsson Ulf
Published: August 2010

For temporary protection of the α‐amino function in amino acids to be used in peptide synthesis in general and solid‐phase peptide synthesis in particular, some new 2‐phenylisopropyloxycarbonyl amino acids have been prepared from the corresponding phenyl carbonate in dimethylsulphoxide using tetramethylguanidine as the base. Experiments so far indicate that these derivatives might be attractive as a substitute for the structurally related, very acid‐labile Bpoc‐amino acids, whose main advantages they seem to share. In our opinion, however, 2‐phenylisopropyloxycarbonyl amino acids have several advantages over Bpoc‐derivatives. They are much more economically prepared, generally more easily characterized, and show improved stability on storage. Their preparation on any laboratory scale is nearly as simple as in the case of Boc‐ and Z‐amino acids.

Rate profiles for removal of the protecting group under solid‐phase peptide synthesis conditions are presented. Finally, the new derivatives have been applied to the synthesis of bradykinin using Merrifield's technique.
ON THE LIMITED PEPTIC DIGESTION OF HORSE HEART CYTOCHROME C. ISOLATION OF C‐TERMINAL PEPTIDE SEQUENCES
Authors: Fontana Angelo , Vita Claudio , Toniolo Claudio
Published: August 2010

Proteolysis of horse heart cytochrome C with pepsin for 3 min produces a large heme peptide, which was shown to be a mixture of the sequences 1–64 and 1–66. By ion exchange chromatography, gel filtration and preparative paper chromatography the heme‐free fraction was resolved into seven peptide fragments, corresponding to sequences 65–94, 65–96, 67–94, 67–96, 67–80, 95–104 and 97–104.
COMPUTER PROGRAM FOR LOCALIZATION OF DISULFIDE BONDS IN PROTEINS
Authors: Bishop Yvonne M. M. , Katsioules Christine C. , Meienhofer Johannes
Published: August 2010

A Fortran computer program to aid in disulfide bond analysis in proteins has been developed. The program evaluates amino acid analysis data from isolated cystine‐containing peptides by comparing it with known sequences around pairs of half‐cystine residues in the primary structure of a protein and recording all matches. The method involves presetting upper and lower bounds for each amino acid present in a cystine‐containing peptide by considering both partial degradation during acid hydrolysis and contamination sources for certain amino acids. Initially, limiting path terminals for each half‐cystine residue in the primary structure are determined by examining the surrounding sequences in both directions for “alien” amino acid residues, not present in the composition of a given cystine‐containing peptide. Subsequently, pairwise examination proceeds through several cycles incorporating minimal path and upper bound routines with intermittent revision of path ends. Finally, all pairs of half‐cystines whose surrounding sequences fall within the preset bounds for this peptide are listed. If too many possible pairs or none are found, the bounds are revised. The lists for all available cystine‐containing peptides are graphed to facilitate final determination of disulfide bond positions in the native protein.

The computer program provided finite disulfide bond assignments for ovine lactogenic hormone and human growth hormone. In the case of hen egg‐white lysozyme, a considerable reduction was obtained from the large number of theoretically possible disulfide bond combinations to a few alternatives, and one of the four disulfide bonds was unequivocally determined. To assign the positions of the other three disulfide bridges, additional considerations, not included in the program, were applied, such as specificity of the enzymes used in digesting the protein and electrophoretic mobility of the ensuing cystine‐containing peptides
SEQUENCE DEPENDENT DEAMIDATTON RATES FOR MODEL PEPTIDES OF HISTONE IV
Authors: Robinson Arthur B. , Scotchler James W.
Published: August 2010

It was found that the first‐order deamidation half‐times of the peptides Gly‐Asp‐Asn‐Ile‐Gly, Gly‐Glu‐Asn‐Val‐Gly, Gly‐Arg‐Gln‐Gly‐Gly, and Gly‐Ile‐Gln‐Gly‐Gly in pH 7.4, 1 = 0.2, 37°C phosphate buffer are 75, 145, 305, and 735 days respectively. These peptides are analogous to the amide parts of histone IV. The findings are discussed with respect to the possible biological implications of deamidation of chromosomal proteins.
REACTION OF CYSTEINE THIOL GROUPS WITH 1,3‐PROPANE SULTONE: S‐3‐SULPHOPROPYL AS A MODIFYING GROUP FOR PROTEIN CHEMISTRY*
Authors: Rüegg Urs Th. , Rudinger Josef
Published: August 2010

Cysteine is smoothly converted to S‐3‐sulphopropylcysteine by 3‐hydroxypropane‐sulphonic acid γ‐sultone (1,3‐propane sultone) in aqueous propanol at pH 8.3. The reaction is about 12 times slower than with iodoacetate but the selectivity for thiol groups is similar, as judged from model experiments and reactions with proteins. S‐3‐Sulphopropylcysteine is stable to the conditions to total acid hydrolysis and behaves distinctively in electrophoresis and ion‐exchange chromatography. Reduction and alkylation of bovine insulin and human serum albumin (pH 8.3, 50% aqueous propanol) on a preparative or analytical scale gives fully S‐substituted derivatives. The S‐sulphopropylated A and B chains of insulin have been separated by precipitation or ion‐exchange chromatography. The sulphopropyl derivatives have good handling properties and the reaction with propane sultone is suggested as a useful addition to the methods of protein chemistry.
SOME PROPERTIES OF CATHEPSINS CHEMICALLY FIXED TO CARRIERS
Authors: Kazakova O. V. , Orekhovich V. N.
Published: August 2010

An insoluble preparation of rat liver cathepsin D was obtained by coupling the enzyme to Enzacryl Polyacetal (EPA‐cathepsin) and to CNBr‐activated Sepharose 4B. EPA‐cathepsin was active toward the synthetic hexapeptides (Gly‐Phe‐Leu)2 and did not split hemoglobin. The optimum pH of splitting was displaced upward by 1.5 units to pH 5.0. The enzyme exhibited maximum activity at 60°C. No appreciable loss of activity was seen on storage of the enzyme for 4 months or after repeated use of the preparations. Coupling of rat liver cathepsin D to activated Sepharose gave preparations active towards both protein and synthetic substrates. The preparations were totally inactive in acid media and exhibited maximum activity at pH 7.0, that is, under physiological conditions. Optimum temperature was 65°. The specific activity of the preparations (pH 7.0, 65°) was 60–110% that of the free enzyme in acid media. Proteolytic activity of the Sepharose‐coupled cathepsin D was not inhibited by pepstatin, whereas that of the free enzyme was fully inhibited by this reagent. A sarcoma cathepsin, similar in some of its properties to the rat liver enzyme, was also coupled to CNBr‐activated Sepharose 4B. The preparation split protein substrates at pH 7.0 and possessed enhanced thermostability. The enzymes fixed on Sepharose showed increased stability.
SYNTHESIS BY CONVENTIONAL METHODS OF HUMAN GROWTH HORMONE PEPTIDE FRAGMENTS. I.
Authors: Chillemi F.
Published: August 2010

The synthesis of two protected peptides which correspond to positions 139–146 and 147–156 of the HGH primary structure is described. These peptides prepared by the stepwise procedure, are: Boc‐Phe‐Lys(Z)‐Gln‐Thr(Bzl)‐Tyr(Bzl)‐Ser(Bzl)‐Lys(Z)‐Phe‐OMe and Boc‐Asp(OBzl)‐Thr(Bzl)‐Asn‐Ser(Bzl)‐His(Dnp)‐Asn‐Asp(OBzl)‐Asp(OBzl)‐Ala‐Leu‐OBzl. All protected intermediates were isolated and characterized for homogeneity.
PITUITARY LACTOGENIC HORMONE. XXXVII.
Authors: Yamashiro Donald , Rigbi Meir , Bewley Thomas A. , Li Choh Hao
Published: August 2010

The carboxyl terminal cyclic undecapeptide of the ovine prolactin molecule: Leu‐Asn‐Cys‐Arg‐Ile‐Ile‐Tyr‐Asn‐Asn‐Asn‐Cys has been synthesized by the solid‐phase method. The circular dichroism of the synthetic peptide has been investigated. It was also found that the cyclic undecapeptide does not have pigeon crop‐sac stimulating activity, or immunological activity when tested by complement fixation experiments.
1H‐ AND 13C‐N.M.R. SPECTRA OF ELEDOISIN AND INTERMEDIATE OLIGOPEPTIDES*
Authors: DeMarco A. , Gatti G.
Published: August 2010

The 1H‐ and 13C‐n.m.r. spectra of eledoisin and minor oligopeptides were measured and assigned. The proton spectra were interpreted on the basis of homonuclear decoupling, chemical shift criteria and spectra simulation. The information obtained was used in the assignment of the 13C spectrum via heteronuclear decoupling 1H‐13C. The steric arrangement of proline residue was deduced from the 13C spectrum. Moreover the similarity of the 13C spectrum of eledoisin with that of component oligopeptides suggests that no considerable conformational change occurs in the undecapeptide relative to the component fragments.