Structural characterization of proteoglycans produced by testicular peritubular cells and Sertoli cells

The structural characteristics of proteoglycans produced by seminiferous peritubular cells and by Sertoli cells are defined. Peritubular cells secrete two proteoglycans designated PC I and PC II. PC I is a high molecular mass protein containing chondroitin glycosaminoglycan (GAG) chains (maximum 70 kDa). PC II has a protein core of 45 kDa and also contains chondroitin GAG chains (maximum 70 kDa). Preliminary results imply that PC II may be a degraded or processed form of PC I. A cellular proteoglycan associated with the peritubular cells is described which has properties similar to those of PC I. Sertoli cells secrete two different proteoglycans, designated SC I and SC II. SC I is a large protein containing both chondroitin (maximum 62 kDa) and heparin (maximum 15 kDa) GAG chains. Results obtained suggest that this novel proteoglycan contains both chondroitin and heparin GAG chains bound to the same core protein. SC II has a 50-kDa protein core and contains chondroitin (maximum 25 kDa) GAG chains. A proteoglycan obtained from extracts of Sertoli cells is described which contains heparin (maximum 48 kDa) GAG chains. In addition, Sertoli cells secrete a sulfoprotein, SC III, which is not a proteoglycan. SC III has properties similar to those of a major Sertoli cell-secreted protein previously defined as a dimeric acidic glycoprotein. The stimulation by follicle-stimulating hormone of the incorporation of [35S]SO2(-4) into moieties secreted by Sertoli cells is shown to represent an increased production or sulfation of SC III (i.e. dimeric acidic glycoprotein), and not an increased production or sulfation of proteoglycans. Results are discussed in relation to the possible functions of proteoglycans in the seminiferous tubule.     

Structural alterations in fibronectin correlated with morphological changes in smooth muscle cells

Nontransformed cultures of vascular smooth muscle cells proliferate until they form a confluent sheet of cells. Subsequently, the cells become reorganized to form multicellular nodules that are loosely attached to the substrate. The formation of nodules is facilitated by the addition of medium conditioned by nodular cultures. Nodulation is inhibited by the addition of fibronectin. Fibronectins derived from monolayer culture conditioned medium or from plasma are maximally effective while fibronectin isolated from nodular cell conditioned medium is inactive. Analysis by NaDodSO4-polyacrylamide gel electrophoresis reveals that the nodular cell fibronectin has a molecular weight that is about 20-30 kd less than that of monolayer cell fibronectin. Further, nodular cell conditioned medium contains an activity that can convert both plasma fibronectin and monolayer cell fibronectin to the lower molecular weight correlated with the loss of biological activity.     

The Mechanism of Microbiological Leaker Spoilage of Canned Foods: A Review

S ummary : This review summarizes the work on the subject carried out mainly in the authors'laboratories but also in the associated laboratories of Metal Box Co. Ltd., London, and Plat Manufaktor, Malmö, Sweden. Special attention is paid to the mechanism of bacterial reinfection and how it is influenced by deviations in can construction or can handling procedures. Methods of preventing bacterial reinfection at the most critical points in the canning operation are considered and certain guiding principles are derived.     

A calorimetric study of a polymer–monomer complex formed by polyuridylic acid 3′,5′-cyclic AMP

The existence of a soluble complex formed by polyuridylic acid (poly (U)) and 3′,5′-cyclic AMP (cAMP) is demonstrated by u.v. extinction vs. temperature curves, optical rotation, equilibrium dialysis, and reaction calorimetry. The complex hasthe stoichiometry of 2 poly (U)-cAMP and its formation is accompanied by an enthalpy change of ?13.0 kcal/mole of base triplet. The introuction of an empirical factor α in the equations given by Damle² and Crothers² leads to the evolution of a ΔH value of ?13.4 keal/mole. The parameter α is considered as a correction factor for the concentration dependence of the binding process. There is no relation between α and the reduction of monomer activity due to self-association of monomers. The study of the binding process at several temperatures showed that the cooperativity parameter, σ, is independent of temperature and its value of 6.5 × 10^?3 is in good agreement with σ = 5 × 10^?3 for the poly (U)·poly(A) system.³     

Das Wachstum infiltrierter Keimlinge

Zusammenfassung Werden Keimlinge vonHelianthus annuus undVicia faba mittels einer Wasserstrahlpumpe mit Wasser infiltriert, so führt dies sofort in allen Organen der Pflanze zu einer sehr starken und mitunter völligen Hemmung des Wachstums. Wirkt der Unterdruck in Luft ein, so daß es hernach zu keiner Wasserfüllung der Interzellularen kommt, so unterbleibt jede Wachstumshemmung.Die Frage nach der Kausalbeziehung zwischen Infiltration und Wachstumshemmung konnte nicht geklärt werden, da die nächstiliegende Annahme, Infiltration führe zu einer Atmungshemmung, durch das Experiment nicht bestätigt werden konnte.Es wird darauf hingewiesen, daß die Zufuhr von Wirk- oder Nährstoffen durch Infiltration eine Methode ist, die in wachsenden Organen nur mit großem Vorbehalt angewendet werden darf, da eine im Wachstum weitgehend gehemmte Pflanze sich in einem anomalen Zustand befindet.Mit 8 Textabbildungen.     

Untersuchungen über das osmotische Verhalten der GrünalgeValonia ventricosa

Zusammenfassung 1.Valonia ventricosa ist eine pantropisch verbreitete marine Grünalge (einziger Fundort im Mittelmeer: Insel Ibiza). Die hier dargestellten Untersuchungen wurden an der Ostküste Venezuelas durchgeführt.2. Die osmotischen Werte (kryoskopisch bestimmt) liegen 1 bis 3 atm über dem Wert des Meerwassers.3. Wachstum und Alter der Zellen ändern den osmotischen Wert nicht.4. Aus Meerwasser in destilliertes Wasser überführt, tritt sehr rasche Abnahme des osmotischen Wertes des Zellsaftes ein (innerhalb von 160 Minuten von 26 auf 2 atm).5. Infolge der größeren relativen Oberfläche nimmt der osmotische Wert kleinerer Zellen viel schneller als der größerer.6. In konzentriertem Meerwasser (31 atm) ändern sich die Zellsaftwerte innerhalb von 3 Stunden nicht.7. In stärker konzentriertem Meerwasser sterben die Zellen rasch ab. Ihr Zellsaft wird damit zum Spielball der Außenbedingungen.8.Valonia ventricosa ist somit ein stenohaliner Organismus ohne erkennbare Fähigkeit zur Osmoregulation.9. Zugabe von CaCl₂ zum destillierten Wasser verlangsamt zunächst die Abnahme des osmotischen Wertes.10. Die chemische Untersuchung des Zellsaftes zeigt auch bei dieser Art das Vorherrschen des Kaliums, das gegenüber dem Meerwasser 66fach konzentriert ist.11. Die Zellwand färbt sich mit Methylenblau stark an, ist jedoch für diesen Farbstoff in keiner Richtung permeable. Angefärbte Zellwände scheinen eine geringe Ionenpermeabilität zu besitzen.12. Elektronenoptische Untersuchnugen der Zellwände zeigen, daß diese aus 40 bis 50 Lamellen bestehen, wobei benachbarte Lamellen eine überkreuzte Paralleltextur (Fischgrätenmuster) besitzen. Da die Zellen — im Gegensatz zu anderenValonia-Arten — nicht in destilliertem Wasser platzen, muß die Zellwand entweder hohe Drucke auszuhalten vermögen oder eine relativ geringe Wasserpermeabilität besitzen.

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Investigations on the osmotic behaviour of the green algaValonia ventricosa

Among the marine Chlorophyta,Valonia ventricosa represents a pantropic species; one of its few extratropical localities is the island Ibiza in the Mediterranean. Our physiological investigations were carried out during several months between 1960 and 1963 in the coastal waters of Venezuela (Mochima Bay near Cumana). The following results were obtained: 1. The osmotic values (measured with the kryoskopic method) are 1 to 3 atm higher than those of the seawater (salinity 36–37 ). 2. Neither size nor age of the cells influence the osmotic characteristics of the cell sap. 3. A transfer from marine to distilled water causes a rapid decrease of the osmotic values (within 160 minutes from 26 to 2 atm). Due to the bigger relative surface, this decrease is more rapid in small cells than in the bigger ones. 4. In concentrated seawater with 31 atm the osmotic values of the cells did not change within 3 hours. 5. In more concentrated or in diluted seawater, the cells are irreversibly damaged within a short time.Valonia ventricosa can therefore be considered as a stenohaline aliga without any recognizable osmoregulation. 6. Addition of CaCl₂ delays the decrease of the osmotic value. 7. Chemical analysis of the cell sap demonstrates the well-known prevalence of potassium, which is 66 times more concentrated than in seawater. 8. The cell wall can be easily stained with methyleneblue and in this case the permeability for anorganic ions is probably reduced. 9. Photographs taken with the electron-microscope show in cross section the multilammellate nature of the cell wall and the change of the fibrillar-direction from one lamella to the other, giving the picture of a cross-fibrillar structure. Since the cells — in contradiction to those of otherValonia species — do not burst in distilled water, it must be assumed that the cell wall structure is able to resist high pressures (about 26 atm) or is characterized by a relatively low water-permeability.

     

Interspecific incompatibility due to stylar barriers in tuber-bearing and closely related non-tuber-bearing Solanums

Summary The phenomenon of interspecific incompatibility between various wild tuber-bearing and closely related non-tuber-bearing Solanum species was studied. One area of investigation included an examination of possible protein interactions in the incompatibility reaction using SDS electrophoresis. Pollen tube inhibition and morphology were examined in conjunction with biochemical analysis. Two sets of crosses were examined: interspecific tuber-bearing species crosses and interspecific tuber-bearing × non-tuber-bearing species crosses. These crosses had consistent pollen tube inhibition in the upper one-third of the style. The upper third of the styles of incompatibly pollinated, compatibly pollinated, and unpollinated styles was studied under fluorescence microscopy to observe pollen tube growth and morphology. Interspecific tuber-bearing × non-tuber-bearing species crosses demonstrated consistent pollen tube inhibition just below the stigma with frequent pollen tube swelling and bursting and extensive callose deposition along the pollen tube wall. Interspecific tuber-bearing species crosses had pollen tube inhibition further down the style with pollen tube tip tapering and extensive callose deposition. Stylar proteins of the lower two-thirds of the styles were analyzed with SDS electrophoresis. No unique protein differences were found to be specifically associated with the interspecific incompatibility reaction in this portion of the style.Cooperative investigation of the U.S. Department of Agriculture, Agricultural Research Service, and the Wisconsin Experiment Station. Supported in part by the USDA, Cooperative States Research Service Competitive grant no. 83-CRCR-1-1253     

A new approach for rhizosphere research by X-ray microanalysis of microliter soil solutions

Lolium perenne growing with high root density on a fine nylon mesh (Kuchenbuch and Jungk, 1982) caused the development of element gradients in the rhizosphere below the mesh. Micro-liter soil solutions from 2-mg soil samples were sprayed onto Formvar-coated grids and analyzed by X-ray microanalysis in a transmission electron microscope. The results were comparable to those obtained by flame photometry and atomic absorption spectrometry (AAS) of conventional soil solutions from 1 g soil. X-ray microanalysis of micro-soil solutions allows the application of different extraction procedures to even small amounts of soil usually available from rhizosphere experiments. Information about soil buffering characteristics in the rhizosphere can thus be obtained. Aluminum accumulation in the rhizosphere of small segments of single Picea abies fine roots grown in undisturbed natural forest soil could be detected with this technique.     

Characterization of serological properties of polyclonal antibodies produced against enzymes involved in the L-selective cleavage of hydantoin derivatives

Summary Polyclonal antibodies were produced against the highly purified enzymes L-hydantoinase, hydantoin-racemase and L-N-carbamoylamino acid amidohydrolase of Arthrobacter aurescens DSM 3747. In order to exploit these antibodies for basic research (molecular biology) or bioengineering (process development), the serological properties had to be characterized. Both, the hydantoinase- and carbamoylase-antibodies were observed to be monofunctional, whereas the hydantoin-racemase-antibody was found to be additionally specific against the L-hydantoinase. Monospecificity was realized after affinity chromatography. Investigations on serological crossreactions with several linear- and cyclic amidases (e.g. hydantoinases) as well as hydantoin-racemases are demonstrated in this paper.Deticated to Prof. Dr. Klaus Mosbach on the occation of his 60th birthday.