Protein turnover in malnourished patients with cystic fibrosis: Effects of elemental and nonelemental nutritional supplements

To evaluate the relative efficacy of nonele-mental versus semielemental enteral supplements for nutritional rehabilitation of cystic fibrosis (CF) patients, whole-body protein turnover using the [15N]glycine method was studied in nine malnourished CF patients during enteral feedings, in a block design study compar-ing a semielemental formula (Criticare), a higher protein density but nonelemental formula (Traumacal) (T), and a nonelemental formula that had been modified to become isocaloric and isonitrogenous to the semielemental formula (modified Traumacal, MT). No significant differences in rates of protein synthesis or catabolism were observed comparing the three formulas. However the higher protein density nonelemental formula resulted in higher net protein deposition compared to the other two formulas (T + 0.42 g kg-110 h-1versus 0.33 g kg-110 h-1for Criticare and-0.59 g kg-110 h-1for MT), although this was significant (p < 0.05) for the MT versus T comparison only. This study lends support to the use of less expensive nonelemental formulas for the nutritional management of malnourished patients with CF. © 1990 Raven Press Ltd, New York.

Intra and Inter-Molecular Communications Through Protein Structure Network

Communication within and across proteins is crucial for the biological functioning of proteins. Experiments such as mutational studies on proteins provide important information on the amino acids, which are crucial for their function. However, the protein structures are complex and it is unlikely that the entire responsibility of the function rests on only a few amino acids. A large fraction of the protein is expected to participate in its function at some level or other. Thus, it is relevant to consider the protein structures as a completely connected network and then deduce the properties, which are related to the global network features. In this direction, our laboratory has been engaged in representing the protein structure as a network of non-covalent connections and we have investigated a variety of problems in structural biology, such as the identification of functional and folding clusters, determinants of quaternary association and characterization of the network properties of protein structures. We have also addressed a few important issues related to protein dynamics, such as the process of oligomerization in multimers, mechanism on protein folding, and ligand induced communications (allosteric effect). In this review we highlight some of the investigations which we have carried out in the recent past. A review on protein structure graphs was presented earlier, in which the focus was on the graphs and graph spectral properties and their implementation in the study of protein structure graphs/networks (PSN). In this article, we briefly summarize the relevant parts of the methodology and the focus is on the advancement brought out in the understanding of protein structure-function relationships through structure networks. The investigations of structural/biological problems are divided into two parts, in which the first part deals with the analysis of PSNs based on static structures obtained from x-ray crystallography. The second part highlights the changes in the network, associated with biological functions, which are deduced from the network analysis on the structures obtained from molecular dynamics simulations.

Pesticide residues in food - acute dietary exposure

Consumer risk assessment is a crucial step in the regulatory approval of pesticide use on food crops. Recently, an additional hurdle has been added to the formal consumer risk assessment process with the introduction of short-term intake or exposure assessment and a comparable short-term toxicity reference, the acute reference dose. Exposure to residues during one meal or over one day is important for short-term or acute intake. Exposure in the short term can be substantially higher than average because the consumption of a food on a single occasion can be very large compared with typical long-term or mean consumption and the food may have a much larger residue than average. Furthermore, the residue level in a single unit of a fruit or vegetable may be higher by a factor (defined as the variability factor, which we have shown to be typically ×3 for the 97.5th percentile unit) than the average residue in the lot. Available marketplace data and supervised residue trial data are examined in an investigation of the variability of residues in units of fruit and vegetables. A method is described for estimating the 97.5th percentile value from sets of unit residue data. Variability appears to be generally independent of the pesticide, the crop, crop unit size and the residue level. The deposition of pesticide on the individual unit during application is probably the most significant factor. The diets used in the calculations ideally come from individual and household surveys with enough consumers of each specific food to determine large portion sizes. The diets should distinguish the different forms of a food consumed, eg canned, frozen or fresh, because the residue levels associated with the different forms may be quite different. Dietary intakes may be calculated by a deterministic method or a probabilistic method. In the deterministic method the intake is estimated with the assumptions of large portion consumption of a ‘high residue’ food (high residue in the sense that the pesticide was used at the highest recommended label rate, the crop was harvested at the smallest interval after treatment and the residue in the edible portion was the highest found in any of the supervised trials in line with these use conditions). The deterministic calculation also includes a variability factor for those foods consumed as units (eg apples, carrots) to allow for the elevated residue in some single units which may not be seen in composited samples. In the probabilistic method the distribution of dietary consumption and the distribution of possible residues are combined in repeated probabilistic calculations to yield a distribution of possible residue intakes. Additional information such as percentage commodity treated and combination of residues from multiple commodities may be incorporated into probabilistic calculations. The IUPAC Advisory Committee on Crop Protection Chemistry has made 11 recommendations relating to acute dietary exposure.

Short-term nutritional supplementation during management of pulmonary exacerbations in cystic fibosis: A controlled study, including effects of protein turnover

Effects of nutritional supplements on minimizing weight loss and abnormalities of protein turnover during pulmonary exacerbations in cystic fibrosis (CF) were studied by controlled trial. Patients received pulmonary therapy and either standard diet (n = 10) or adjunctive enteral supplements (n = 12). Initial protein turnover, measured by [15N]glycine kinetics, showed alterations of protein synthesis (P Syn) and catabolism (P Cat), which correlated with the degree of underweight, and negligible net protein deposition (P Dep). With treatment both groups had significant increases in mean body weight and forced expiratory volume in 1 s, expressed as percent predicted value for height (FEV1) by 3 wk, but a significant correlation between initial underweight and subsequent weight gain was observed only in supplemented patients. Mean P Syn and P Dep increased significantly (p < 0.001) only in the supplemented group. Pulmonary exacerbations in CF have important adverse effects on body-protein metabolism, similar to changes in protein-energy malnutrition and infection. These effects are reversed by short-term nutritional support. Strategic nutritional intervention should thus be considered in management, especially in malnourished patients.

Sustaining productivity of a Vertosol at Warra, Queensland, with fertilisers, no-tillage or legumes. 8. Effect of duration of lucerne ley on soil nitrogen and water, wheat yield and protein.

Soil nitrogen (N) supply in the Vertosols of southern Queensland, Australia has steadily declined as a result of long-term cereal cropping without N fertiliser application or rotations with legumes. Nitrogen-fixing legumes such as lucerne may enhance soil N supply and therefore could be used in lucerne-wheat rotations. However, lucerne leys in this subtropical environment can create a soil moisture deficit, which may persist for a number of seasons. Therefore, we evaluated the effect of varying the duration of a lucerne ley (for up to 4 years) on soil N increase, N supply to wheat, soil water changes, wheat yields and wheat protein on a fertility-depleted Vertosol in a field experiment between 1989 and 1996 at Warra (26degrees 47'S, 150degrees53'E), southern Queensland. The experiment consisted of a wheat-wheat rotation, and 8 treatments of lucerne leys starting in 1989 (phase 1) or 1990 (phase 2) for 1,2,3 or 4 years duration, followed by wheat cropping. Lucerne DM yield and N yield increased with increasing duration of lucerne leys. Soil N increased over time following 2 years of lucerne but there was no further significant increase after 3 or 4 years of lucerne ley. Soil nitrate concentrations increased significantly with all lucerne leys and moved progressively downward in the soil profile from 1992 to 1995. Soil water, especially at 0.9-1.2 m depth, remained significantly lower for the next 3 years after the termination of the 4 year lucerne ley than under continuous wheat. No significant increase in wheat yields was observed from 1992 to 1995, irrespective of the lucerne ley. However, wheat grain protein concentrations were significantly higher under lucerne-wheat than under wheat wheat rotations for 3-5 years. The lucerne yield and soil water and nitrate-N concentrations were satisfactorily simulated with the APSIM model. Although significant N accretion occurred in the soil following lucerne leys, in drier seasons, recharge of the drier soil profile following long duration lucerne occurred after 3 years. Consequently, 3- and 4-year lucerne-wheat rotations resulted in more variable wheat yields than wheat-wheat rotations in this region. The remaining challenge in using lucerne-wheat rotations is balancing the N accretion benefits with plant-available water deficits, which are most likely to occur in the highly variable rainfall conditions of this region.

The Biosynthesis of Sesquiterpene Isocyanides and Isothiocyanates in the Marine Sponge Acanthella cavernosa (Dendy); Evidence for Dietary Transfer to the Dorid Nudibranch Phyllidiella pustulosa

The tropical marine sponge Acanthella cavernosa (Dendy) converts potassium [14C] cyanide to axisonitrile-3 (1); this precursor is also used for the synthesis of axisothiocyanate-3 (2) suggesting that isocyanides are precursors to isothiocyanates in A. cavernosa. Likewise, potassium [14C] thiocyanate is used for the synthesis of axisothiocyanate-3; unexpectedly this precursor also labelled axisonitrile-3. These results demonstrate either an interconversion between cyanide and thiocyanate prior to secondary metabolite formation or that the secondary metabolites can themselves be interconverted. Specimens of the dorid nudibranch Phyllidiellu pustulosa, preadapted to a diet of A. cavernosa, fed on 14C-labelled sponges and were subsequently found to contain the radioactive terpenes (1) and (2). Specimens of P. pustulosa, which had not expressed a dietary preference for A. cavernosa in the field, did not generally feed in aquarium tests with 14C-labelled sponges and, therefore, provided non-radioactive extracts. Since control experiments demonstrated the inability of P. pustulosa to synthesise the metabolites de novo, we therefore conclude that P. pustulosa acquires secondary metabolites by dietary transfer from A. cavernosa.

Inverse Correlation between Vitamin D and C-Reactive Protein in Newborns

Some studies suggested that adequate vitamin D might reduce inflammation in adults. However, little is known about this association in early life. We aimed to determine the relationship between cord blood 25-hydroxyvitamin D (25(OH)D) and C-reactive protein (CRP) in neonates. Cord blood levels of 25(OH)D and CRP were measured in 1491 neonates in Hefei, China. Potential confounders including maternal sociodemographic characteristics, perinatal health status, lifestyle, and birth outcomes were prospectively collected. The average values of cord blood 25(OH)D and CRP were 39.43 nmol/L (SD = 20.35) and 6.71 mg/L (SD = 3.07), respectively. Stratified by 25(OH)D levels, per 10 nmol/L increase in 25(OH)D, CRP decreased by 1.42 mg/L (95% CI: 0.90, 1.95) among neonates with 25(OH)D <25.0 nmol/L, and decreased by 0.49 mg/L (95% CI: 0.17, 0.80) among neonates with 25(OH)D between 25.0 nmol/L and 49.9 nmol/L, after adjusting for potential confounders. However, no significant association between 25(OH)D and CRP was observed among neonates with 25(OH)D ≥50 nmol/L. Cord blood 25(OH)D and CRP levels showed a significant seasonal trend with lower 25(OH)D and higher CRP during winter-spring than summer-autumn. Stratified by season, a significant linear association of 25(OH)D with CRP was observed in neonates born in winter-spring (adjusted β = −0.11, 95% CI: −0.13, −0.10), but not summer-autumn. Among neonates born in winter-spring, neonates with 25(OH)D <25 nmol/L had higher risk of CRP ≥10 mg/L (adjusted OR = 3.06, 95% CI: 2.00, 4.69), compared to neonates with 25(OH)D ≥25 nmol/L. Neonates with vitamin D deficiency had higher risk of exposure to elevated inflammation at birth.

Protein supplementation and growth enhancer strategies in successive years to maximise growth of Brahman cross steers grazing sown grass pastures on brigalow lands

A strategy comprising a winter/spring protein supplement, rumen modifier and hormonal growth promotant (Compudose 400) was used in either the first year (Tl), second year (T2), or in both years (T1+2) following weaning in Brahman cross steers as a means of increasing liveweight gain up to 2.5 years of age. T2 produced the heaviest final liveweight (544.7 kg) and highest overall liveweight gain (366.7 kg), but these were not significantly different from T1 (538.6 kg; 360.9 kg), or T1+2 (528.7 kg; 349.3 kg). However, final liveweight and overall liveweight gains of T1 and T2 but not T1+2 were significantly greater than for untreated (C) steers (504.9 kg; 325.2 kg, both P < 0.05). Regardless of the strategy imposed, liveweight and liveweight gain were enhanced, however final liveweights in each treatment were below the preferred minimum target liveweight (570-580 kg) for premium export markets. Treatment in both years gave no benefit over treatment in 1 year only. 19th Biennial Conference. 5-9 July 1992. LaTrobe University, Melbourne.

Peanut stripe potyvirus resistance in peanut (Arachis hypogaea L.) plants carrying viral coat protein gene sequences

Peanut (Arachis hypogaea L.) lines exhibiting high levels of resistance to peanut stripe virus (PStV) were obtained following microprojectile bombardment of embryogenic callus derived from mature seeds. Fertile plants of the commercial cultivars Gajah and NC7 were regenerated following co-bombardmentwith the hygromycin resistance gene and one of two forms of the PStV coat protein (CP) gene, an untranslatable, full length sequence (CP2) or a translatable gene encoding a CP with an N-terminal truncation (CP4). High level resistance to PStV was observed for both transgenes when plants were challenged with the homologous virus isolate. The mechanism of resistance appears to be RNA-mediated, since plants carrying either the untranslatable CP2 or CP4 had no detectable protein expression, but were resistant or immune (no virus replication). Furthermore, highly resistant, but not susceptible CP2 T0 plants contained transgene-specific small RNAs. These plants now provide important germplasm for peanut breeding, particularly in countries where PStV is endemic and poses a major constraint to peanut production.

Temporal expression of G-protein-coupled receptor 54 (GPR54), gonadotropin-releasing hormones (GnRH), and dopamine receptor D2 (drd2) in pubertal female grey mullet, Mugil cephalus.

The G-protein-coupled receptor 54 (muGPR54) cDNA was cloned from the brain of the grey mullet, and its expression level, as well as those of the gonadotropin-releasing hormones (GnRH1, GnRH2, GnRH3) and dopamine receptor D2 (drd2), in the brain, pituitary and ovary of pubertal fish (early, intermediate, advanced) were determined by real-time quantitative RT-PCR (QPCR). The muGPR54 cDNA has an open reading frame of 1140 bp with a predicted 380 amino acid peptide, containing seven putative transmembrane domains and putative N-glycosylation and protein kinase C phosphorylation sites. QPCR results showed that the early stage of puberty in grey mullet is characterized by significantly high levels of expression of GPR54, GnRH and drd2 in the brain relative to the intermediate and advanced stages, except for GnRH1 that increased at the advanced stage of puberty. In the pituitary, drd2 expression declined significantly at the advanced stage relative to levels at the intermediate stage. Ovarian expression of GPR54 significantly increased from the intermediate stage of puberty relative to the early stage while that of GnRH1 acutely increased at the advanced stage of puberty. The ovarian expression of drd2 decreased as puberty progressed, but the changes were not significant. The results suggest the possible role of GPR54 and GnRH in positively regulating pubertal development in grey mullet and the dopaminergic inhibition of reproductive function mediated by drd2.

"America Would Lose Its Soul" : The Immigration Restriction Debate, 1920-1924

Vuosien 1830 ja 1924 välillä Yhdysvaltoihin muutti noin 35 miljoonaa eurooppalaista. Tämä niinkutsuttu "maahanmuuton vuosisata" päättyi varsin äkillisesti kun Yhdysvallat päätti rajoittaa maahanmuuttoa 1920-luvulla. Vuosina 1921 ja 1924 säädetyt lait asettivat kansallisuuteen perustuvat kiintiöt kaikille eurooppalaisille maahanmuuttajille; vuoden 1924 laki myös lopetti kokonaan japanilaisten maahanmuuton. Tämä työ tutkii näihin kiintiölakeihin johtanutta maahanmuuttajavastaisuuden kasvua sekä etenkin lakien ympärillä käytyä keskustelua. Pääpaino on kongressissa esitetyissä maahanmuuton vastaisissa argumenteissa. Nämä jakautuivat karkeasti ottaen kolmeen kategoriaan: maahanmuuton vastustajat sanoivat, että siirtolaisten vaikutus taloudelliseen tilanteeseen oli epäsuotuisa, siirtolaisten rodullinen ja kulttuurinen "laatu" oli huonontunut, ja siirtolaiset olivat radikaaleja ja bolshevismiin taipuvaisia. Erityistä huolta herätti maahanmuuttajien vaikutus Amerikan kulttuuriseen, rodulliseen ja poliittiseen yhtenäisyyteen. Huoli kansakunnan yhtenäisyydestä oli tulosta paitsi siirtolaisten määrästä myös amerikkalaisessa yhteiskunnassa tapahtuneista muutoksista. Erityisen tärkeitä olivat työväenliikkeen vaikutusvallan kasvu ja teollisuusjohtajien pyrkimys pysäyttää se. Maahanmuuttajien "bolshevismi" olikin käyttökelpoinen argumentti paitsi maahanmuuttajia myös amerikkalaisia työläisiä vastaan: teollisuusjohtajat painottivat että lakot ja työväenliike olivat tulosta siirtolaisten mukanaan tuomista "epäamerikkalaisista" ajatusmalleista, eivät yhteiskunnan epäoikeudenmukaisuudesta. Kongressin keskustelun lisäksi työssä käsitellään myös eri yhteiskunnallisten ryhmien ja vaikuttajien kantaa siirtolaisuuteen. Keskusteluun maahanmuutosta vaikuttivat etenkin eugenistit ja muut sosiaalitieteilijät, jotka väittivät itä- ja eteläeurooppalaisten olevan rodullisesti anglosakseja huonompia. Tämän väitteen vaikutusvaltaa lisäsivät yhteiskunnassa vallalla olleet ennakkoluulot, ja monet yhdistykset ja liikkeet (mm. Ku Klux Klan ja erilaiset isänmaalliset järjestöt) olivatkin tärkeitä rajoittamisen kannattajia. Keskustelu maahanmuutosta painottui ideologisiin ja tunteellisiin kysymyksiin, mutta rajoitusten taustalla oli myös konkreettisempia tekijöitä. Yhteiskunnan teollistuminen ja kaupungistuminen olivat pienentäneet siirtolaisista koituvaa taloudellista hyötyä: siirtolaisia ei enää tarvittu raivaamaan uusia viljelysmaita, kun taas tuotannon koneistuminen vähensi työvoiman tarvetta huomattavasti. Pitkän aikavälin taloudellisten tekijöiden roolin merkitys käy ilmeiseksi kun otetaan huomioon, että muut maahanmuuttomaat (esim. Kanada ja Australia) eivät juuri rajoittaneet siirtolaisuutta tänä aikana vaikka niissäkin esiintyi runsaasti rodullista ja kulttuurista maahanmuuttajavastaisuutta. Pääsyy rajoitusten vähäisyyteen näissä maissa oli juuri maahanmuuttajien tuoma taloudellinen hyöty, sekä teollisena työvoimana että maanviljelijöinä. Vaikka kiintiölakiehdotusten ympärillä käytiin kiivasta väittelyä, kongressi kuitenkin hyväksyi lait varsin suurella enemmistöllä. Siirtolaisia itseään lukuunottamatta varsin harvat näkivät lait haitallisina, kun taas useat erilaiset ryhmät katsoivat hyötyvänsä maahanmuuton rajoittamisesta. Avainsanat: siirtolaisuus, maahanmuutto, Yhdysvallat, 1920-luku, kiintiölait, maahanmuuton rajoittaminen

Heterologous signals allow efficient targeting of a nuclear-encoded fusion protein to plastids and endoplasmic reticulum in diverse plant species

Approximately 30% of plant nuclear genes appear to encode proteins targeted to the plastids or endoplasmic reticulum (ER). The signals that direct proteins into these compartments are diverse in sequence, but, on the basis of a limited number of tests in heterologous systems, they appear to be functionally conserved across species. To further test the generality of this conclusion, we tested the ability of two plastid transit peptides and an ER signal peptide to target green fluorescent protein (GFP) in 12 crops, including three monocots (barley, sugarcane, wheat) and nine dicots (Arabidopsis, broccoli, cabbage, carrot, cauliflower, lettuce, radish, tobacco, turnip). In all species, transient assays following microprojectile bombardment or vacuum infiltration using Agrobacterium showed that the plastid transit peptides from tomato DCL (defective chloroplast and leaves) and tobacco RbcS [ribulose bisphosphate carboxylase (Rubisco) small subunit] genes were effective in targeting GFP to the leaf plastids. GFP engineered as a fusion to the N-terminal ER signal peptide from Arabidopsis basic chitinase and a C-terminal HDEL signal for protein retention in the ER was accumulated in the ER of all species. The results in tobacco were confirmed in stably transformed cells. These signal sequences should be useful to direct proteins to the plastid stroma or ER lumen in diverse plant species of biotechnological interest for the accumulation of particular recombinant proteins or for the modification of particular metabolic streams.