Distribution of transfer RNA genes in thePisum sativum chloroplast DNA

Purified chloroplast tRNAs were isolated fromPisum sativum leaves and radioactively labeled at their 3′ end using tRNA nucleotidyl transferase and α³²P-labeled CTP. Pea ctDNA was fragmented using a number of restriction endonucleases and hybridized with thein vitro labeled chloroplast tRNAs by DNA transfer method. Genes for tRNAs have been found to be dispersed throughout the chloroplast genome. A closer analysis of the several hybrid regions using recombinant DNA plasmids have shown that tRNA genes are localized in the chloroplast genome in both single and multiple arrangements. Two dimensional gel electrophoresis of total ct tRNA have identified 36 spots. All of them have been found to hybridize withPisum sativum ctDNA. Using recombinant clones, 30 of the tRNA spots have been mapped inPisum sativum ctDNA.     

Strömungsmessungen in der Deutschen Bucht bei Sturmfluten

Zusammenfassung 1. Während der Sturmfluten des Winters 1965/66 sind an acht geographischen Positionen der Deutschen Bucht Strömungsmessungen in zwei, teilweise auch drei verschiedenen Tiefenlagen gemacht worden. Die Auswertung der Meßergebnisse hat Strömungsfelder positiver und negativer Sturmfluten (bei westlichen bzw. östlichen Winden) und Spektren der inneren Bewegungsvorgänge der Deutschen Bucht im Bereich der Schwingungszeiten von 3 bis 90 Stunden ergeben.2. Eine typische Sturmflutperiode mit starken Winden aus SW bis NW trat vom 29. Oktober bis 4. November 1965 auf. Während dieser Zeit haben Strömungsmesser an folgenden Stellen ausgelegen: Vortrapp-Tief, Außeneider, P 8, Helgoland, Elbe I, Weser Feuerschiff, Norderney, Borkumriff. Ihre Meßergebnisse zeigen, daß der Antransport des Wassers in das Gebiet vor der Elbe- und Wesermündung bei positiven Sturmfluten durch starke Strömungen entlang der ostfriesischen Küste erfolgt. Sie erreichen beispielsweise bei schwerem Sturm der Windstärke 10 vor Borkumriff 4 m unter der Wasseroberfläche 90 cm/sec, vor Norderney in einer Wassertiefe 6 m unter K.N. 75 cm/sec. Selbst 2 m über dem Meeresboden ist unter diesen Umständen bei Borkumriff noch ein Strom von 40 cm/sec gemessen worden. Die Richtung dieser Driftströmungen ist selbst bei wesentlichen Änderungen der Windrichtung recht stabil.3. Vor der schleswig-holsteinischen Westküste liegen die Verhältnisse wesentlich komplizierter. Zunächst transportiert der Westwind das Wasser auf die Küste zu. Jedoch entsteht in dem Maße, wie sich vor Elbe- und Wesermündung ein großer Windstau ausbildet, bei der Außeneider ein starker Strom in westlicher bis nordwestlicher Richtung, der das angestaute Wasser wieder abtransportiert, und zwar zeitweilig direkt gegen den Wind. Dieser Gefällstrom erreicht bei schwerem Sturm um 45 cm/sec.4. Vor der schleswig-holsteinischen Küste erfolgt der Abtransport der Wassermassen, die entlang der ostfriesischen Inselkette herantransportiert worden sind.5. Bei der Außeneider treten je nach dem Stau, besonders im Gebiet der Nordfriesischen Inseln, und dem Wind alle Stromrichtungen der Windrose auf. Der Betrag der Geschwindigkeit liegt bei schwerem Sturm um 25 cm/sec.6. In der Zeit vom 17. bis 21. November 1965 haben über der Deutschen Bucht starke Ostwinde geweht und negative Sturmfluten (mit negativem Stau) verursacht. Die Strömungsmessungen aus dieser Zeit ergeben einen Driftstrom um 30 cm/sec in westlicher Richtung entlang der ostfriesischen Inselkette und einen Gefällstrom gleicher Größe im Gebiet P 8 — Außeneider von südlicher Richtung.7. Die Fourier-Integral-Analyse der Strommessungen ergab, daß bei Stürmen im langwelligen Teil des Spektrums jenseits der M₂ intensive zusätzliche Schwingungen mit Perioden um 35 und 65 Stunden auftreten.

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Current measurements in the german bight during storm surges

During the storm surges of the winter period 1965/66 current measurements were conducted in eight geographical positions at two, sometimes also three, different depth layers. The evaluation of the measured data yielded current fields of positive and negative storm surges (at westerly or easterly winds, respectively) and spectra of the internal motion of the German Bight in the oscillation period from 3 to 90 hours. Typical storm surge conditions with strong south-west and north-west winds prevailed in the period from 29 October to 4 November, 1965. Current meters were then placed in the following positions: Vortrapp-Tief, Außeneider, P 8, Helgoland, Elbe 1, Weser light vessel, Norderney, Borkumriff. Their recordings indicate that the transport of water into the areas off the mouths of the rivers Elbe and Weser is, at positive storm surges, effected by strong currents along the east Frisian coast. At heavy storms of 10 Beaufort, for example, they reach 90 cm/sec at 4 m below the surface off Borkumriff, and 75 cm/sec at 6 m below chart datum off Norderney. Even at 2 m above the sea floor a current of 40 cm/sec was measured under these circumstances at Borkumriff. The direction of these drift currents is rather constant even at considerably varying wind directions. Off the coast of Schleswig-Holstein the situation is far more complicated. At first, westerly winds transport the water towards the coast. But in the same manner as a large Windstau forms off the Elbe and Weser mouths, a strong west to north-west current develops at the Außeneider which removes the stemmed water, sometimes directly against the wind. This gradient current reaches 45 cm/sec at heavy storms. Summarizing our findings, it can be said that water masses transported towards the east Frisian islands are removed from the coast of Schlweswig-Holstein. At the Außeneider in particular in the range of the north Frisian islands, all current directions of the wind rose occur, depending on Stau and wind. The velocity rate lies at 25 cm/sec during heavy storm. From November 17 to 21, 1965, strong easterly winds were prevailing over the German Bight and produced negative storm surges (with negative Stau). The current measurements recorded during this time indicate a drift current of about 30 cm/sec in a westerly direction along the east Frisian islands, and a southerly gradient current of about the same rate in the area between P 8 and Außeneider. Fourier-integral-analyses of the current measurements revealed considerable long-wave oscillations in the part of the spectrum beyond the M₂, if heavy storms have prevailed during the recording interval.

     

Neutral elastolytic proteinase from canine leucocytes. Purification and characterization.

1. A neutral proteinase (EC 3.4.-.-) with elastolytic activity was isolated from canine bloodstream leucocytes, and purified to apparent homogeneity by a two-step procedure consisting of DEAE-Sephadex chromatography and molecular sieving on Sephadex G-75. 2. The molecular weight of the enzyme was 23 500, and the absorbance (A1%1cm) at 282 nm was 6.1. Amino acid analysis showed high content of glycine, aspartic acid, and valine, and low proportion of methionine, lysine and histidine as well as the absence of tyrosine in the enzyme molecule. 3. The proteinase was active against several protein substrates as well as towards N-t-butyloxycarbonyl-L-alanine p-nitrophenyl ester, N-acetyl-L-alanyl-tyrosine ethyl ester. 4. The enzyme was inactivated by diisopropylfluorophosphate, N-acetyl-L-alanyl-L-alanyl-L-alanine chloromethyl ketone, and N-p-tosyl-L-phenylalanine chloromethyl ketone. Inhibition by some natural proteinase inhibitors was also noted.     

Specificity of elastases: degradation of the oxidized beta-chain of insulin by porcine pancreatic elastase II and dog leucocyte elastase.

Porcine elastase II (EC 3.4.21.-), a pancreatic proteinase with elastolytic activity, hydrolyses the oxidized beta-chain of insulin with major cleavages occurring at Leu17-Val18, Phe24-Phe25, Phe25-Tyr26 and Tyr26-Thr27. Canine leucocytic elastase splits the same substrate with major sites at Val12-Glu13 and Val18-Cys19 O3H. This indicates similarity of elastase II to chymotrypsins (EC 3.4.21.1 or 3.4.21.2) and of dog leucocyte enzyme to human granulocyte elastase and porcine pancreatic elastase I (EC 3.4.21.11).     

Organic contaminant exposure in the Lake St. Clair food web

Chemical concentrations and distributions in an aquatic food web were studied to quantify the relative importance of chemical properties versus food web processes in determining exposure dynamics of organic contaminants in aquatic ecosystems. Five organochlorines were measured (Pentachlorobenzene QCB, Hexachlorobenzene HCB, Octachlorostyrene OCS, Dichlorodiphenyldichloroethylene DDE and Polychlorinated Biphenyls PCBs) in the food web of Lake St. Clair. Levels of QCB in aquatic organisms ranged from 1.0 to 25 µg kg^–1 lipid, and levels of HCB ranged from 10 to 410 µg kg^–1 lipid. More elevated concentrations of OCS (13 to 392 µg kg^–1 lipid), DDE (162 to 11 986 µg kg^–1 lipid) and PCB (650 to 64 900 µg kg^–1 lipid) were observed. Organism — water equilibrium ratios were calculated for all species sampled to quantify the importance of food web processes in regulating contaminant exposure dynamics. Correlations of organism — water equilibrium ratios with body size were not significant for QCB, HCB and OCS (P>0.1), but were found to be significant for DDE and PCB (P<0.01).Results support the conclusion that both chemical properties and food web dynamics regulate the distribution and concentration of organochlorines in aquatic ecosystems. Food web processes are important, however, for chemicals, that are not metabolized and have octanol — water partition coefficients (log K _ow) greater than 5.5.     

Effect of Age-Stiffening Tissues and Intraocular Pressure on Optic Nerve Damages

Age-stiffening of ocular tissues is statistically linked to glaucoma in the elderly. In this study, the effects of age-stiffening on the lamina cribrosa, the primary site of glaucomatous nerve damages, were modeled using computational finite element analysis. We showed that glaucomatous nerve damages and peripheral vision loss behavior can be phenomenologically modeled by shear-based damage criterion. Using this damage criterion, the potential vision loss for 30 years old with mild hypertension of 25mmHg intraocular pressure (IOP) was estimated to be 4%. When the IOP was elevated to 35mmHg, the potential vision loss rose to 45%; and age-stiffening from 35 to 60 years old increased the potential vision loss to 52%. These results showed that while IOP plays a central role in glaucomatous damages, age-stiffening facilitates glaucomatous damages and may be the principal factor that resulted in a higher rate of glaucoma in the elderly than the general population.     

A mechanism for stabilization of membranes at low temperatures by an antifreeze protein.

Polar fish, cold hardy plants, and overwintering insects produce antifreeze proteins (AFPs), which lower the freezing point of solutions noncolligatively and inhibit ice crystal growth. Fish AFPs have been shown to stabilize membranes and cells in vitro during hypothermic storage, probably by interacting with the plasma membrane, but the mechanism of this stabilization has not been clear. We show here that during chilling to nonfreezing temperatures the alpha-helical AFP type I from polar fish inhibits leakage across model membranes containing an unsaturated chloroplast galactolipid. The mechanism involves binding of the AFP to the bilayer, which increases the phase transition temperature of the membranes and alters the molecular packing of the acyl chains. We suggest that this change in acyl chain packing results in the reduced membrane permeability. The data suggest a hydrophobic interaction between the peptide and the bilayer. Further, we suggest that the expression of AFP type I in transgenic plants may be significant for thermal adaptation of chilling-sensitive plants.     

The effect of hydrophobic analogues of the type I winter flounder antifreeze protein on lipid bilayers

The effect of four synthetic analogues of the 37-residue winter flounder type I antifreeze protein (AFP), which contain four Val, Ala or Ile residues in place of Thr residues at positions 2, 13, 24 and 37 and two additional salt bridges, on the binary lipid system prepared from a 1:1 mixture of the highly unsaturated DGDG and saturated DMPC has been determined using FTIR spectroscopy. In contrast to the natural protein, which increases the thermotropic phase transition, the Thr, Val and Ala analogues decreased the thermotropic phase transitions of the liposomes by 2.2 degrees Celsius, 3.4 degrees Celsius and 2.4 degrees Celsius, while the Ile analogue had no effect on the transition. Experiments performed using perdeuterated DMPC showed that the Ala and Thr peptides interacted preferentially with the DGDG in the lipid mixture, while the Val peptide showed no preference for either lipid. The results are consistent with interactions involving the hydrophobic face of type I AFPs and model bilayers, i.e. the same face of the protein that is responsible for antifreeze properties. The different effects correlate with the helicity of the peptides and suggest that the solution conformation of the peptides has a significant role in determining the effects of the peptides on thermotropic membrane phase transitions.     

NF-kappa B is required within the innate immune system to inhibit microflora-induced colitis and expression of IL-12 p40

We have previously presented evidence demonstrating that mice deficient in NF-kappaB subunits are susceptible to colitis induced by the pathogenic enterohepatic Helicobacter species, H. hepaticus. However, it has not been determined whether NF-kappaB is required within inhibitory lymphocyte populations, within cells of the innate immune system, or both, to suppress inflammation. To examine these issues, we have performed a series of adoptive transfer experiments using recombination-activating gene (Rag)-2(-/-) or p50(-/-)p65(+/-)Rag-2(-/-) mice as hosts for wild-type (WT) and p50(-/-)p65(+/-) lymphocyte populations. We have shown that although the ability of H. hepaticus to induce colitis in Rag-2(-/-) mice is inhibited by the presence of either WT or p50(-/-)p65(+/-) splenocytes, these splenocyte populations are unable to suppress H. hepaticus-induced colitis in p50(-/-)p65(+/-)Rag-2(-/-) mice. Colitis in these animals is characterized by increased expression of inflammatory cytokines including IL-12 p40, and depletion of IL-12 p40 from p50(-/-)p65(+/-) mice ameliorates H. hepaticus-induced disease. Consistent with a primary defect in the regulation of IL-12 expression, H. hepaticus induced markedly higher levels of IL-12 p40 in p50(-/-)p65(+/-) macrophages than in WT macrophages. These results suggest that inhibition of H. hepaticus-induced IL-12 p40 expression by NF-kappaB subunits is critical to preventing colonic inflammation in response to inflammatory microflora.