Synthesis of a versatile constrained analogue of dipeptide DG (Asp-Gly)

Summary. The synthesis of an orthogonally protected constrained analogue of dipeptide DG (Asp-Gly) is reported exploiting alkylation of a chiral lactam. The versatility of this analogue was proven by removal of t-Boc protecting group, followed by coupling under homogeneous conditions with t-Boc-Arg(Z₂)-Gly, to give a conformationally restricted analogue of RGDG tetrapeptide. Authors’ address: Mario Orena, Dipartimento di Scienze e Tecnologie Chimiche, Università Politecnica delle Marche, Via Brecce Bianche, I-60131 Ancona, Italy     

Primo Saggio di Ricerche sul Fitoplanton di Alcuni Laghi Dell'umbria,Abruzzo e Campania

Riassunto

L'A. studia il fitoplancton di nove bacini lacustri dell'Appennino centro-meridionale, precisamente Trasimeno, Piediluco, Ripa Sottile, Cantalice, Scanno, S. Raniero, S. Luigi, Cupia e Matese; con questo primo saggio di ricerche l'A. inizia lo studio di una biolimnologia comparata dei nostri bacini peninsulari; Ie diverse facies fitoplanctoniche vengono studiate in base ai caratteri geo-fisici del bacino (chimismo delle acque e loro trofismo).     

Erratum to Sabina Pucci et al., Cell Cycle Volume 8, Issue 3; pp. 473-481.

In the report “Interleukin-6 affects cell death escaping mechanisms acting on Bax-Ku70-Clusterin interactions in human colon cancer progression” by Sabina Pucci, Paola Mazzarelli, Fabiola Sesti, David A. Boothman and Luigi G. Spagnoli (Cell Cycle 2009; 8:473-81), there was a minor error in the authors names. The original names on page 473, reads: Sabina Pucci, Mazzarelli Paola, Sesti Fabiola, Boothman A. David and Spagnoli G. Luigi. The author’s names should have been Sabina Pucci, Paola Mazzarelli, Fabiola Sesti, David A. Boothman and Luigi G. Spagnoli.     

Ovary-ovule transmitting tract in Crocus (Iridaceae), structure and calcium distribution

 The structure of and the calcium distribution in the ovary-ovule transmitting tracts of Crocus were examined by using conventional and antimonate fixation methods for electron microscopy, and fluorescence microscopy as well. The ovarian locules are bordered with epidermal cells and transmitting cells. The epidermal cells are extensively cutinized, and the cytoplasm is rich in the organelles and vesicles prevalently engaged in thickening the exposed wall. The transmitting cells have uncutinized walls with numerous labyrinthine ingrowths, and the cytoplasm is rich in organelles and vesicles engaged in the secretion of the extracellular matrix (e.m.). The micropylar tissue of the ovule consists of largely vacuolated cells with scarcely structured cytoplasm, the e.m. appears to be of gametophytic origin. Both the ovary and ovule e.m. have a glycosidic and proteinic nature, and are rich in loosely bound Ca²⁺ ions. In the embryo sac, Ca²⁺ ions are concentrated in one synergid. The results are discussed in relation to the guided growth of pollen tubes. Received April 9, 2002; accepted July 9, 2002 Published online: November 28, 2002 Addresses of the authors: Giuseppe Chichiriccò (e-mail: Chichiri@univaq.it), Dipartimento di Scienze Ambientali, University of L'Aquila, Via Vetoio, I-67100 L'Aquila, Italy. Anna Maria Ragnelli, Pierpaolo Aimola, Dipartimento di Biologia di Base ed Applicata, University of L'Aquila, Via Vetoio, I-67100 L'Aquila, Italy.     

Docosahexaenoic acid ethyl esters from Isochrysis galbana

In order to produce docosahexaenoic acid (DHA), a culture of the microalgal strain Isochrysis galbana was implemented. In Erlenmeyer flasks, a natural seawater medium, the Provasoli 1/3 medium, was compared to the classical Jones medium for DHA production. The Provasoli 1/3 medium stimulated growth (0.44 d(-1)), but influenced DHA accumulation negatively (0.240 pg cell(-1)). However, DHA production per liter of culture medium were of the same order of magnitude with both media (0.961 mg l(-1)). In a 2-l bioreactor, DHA production per liter of culture medium did not increase significantly between 4 and 8 days of culture. With a view to optimize DHA productivity, cells should be harvested at the end of exponential phase i.e. after 4 days of culture. Two strategies were then attempted to produce DHA ethyl esters. First, lipids from I. galbana were submitted to lipase-catalyzed transesterification with ethanol. Secondly, fatty acids from I. galbana were submitted to lipase catalyzed esterification with ethanol. In both cases, lipase from Candida antarctica was shown to be the best candidate, among the five tested, with conversion yields of 20 and 60% after 24 h of transesterification and esterification respectively.     

<Emphasis Type="Italic">Catharanthus roseus</Emphasis> L. plants and explants infected with phytoplasmas: alkaloid production and structural observations

Summary. The results of several experiments concerning the presence and composition of alkaloids in different tissues (stems, leaves, roots) of Catharanthus roseus L. plants and explants, healthy and infected by clover phyllody phytoplasmas, are reported. The alkaloids extracted and determined by the reverse phase high-pressure liquid chromatography were vindoline, ajmalicine, serpentine, vinblastine, and vincristine. The total alkaloid concentration was higher in infected plants than in the controls, in particular the increase of vinblastine in infected roots was very significant. The ultrastructural observations of infected roots showed alterations of the cell walls and of the nuclei. These results demonstrate that phytoplasmas, detected in all infected tissues by light fluorescence and transmission electron microscopy, play an important role on secondary metabolism of the diseased plants, modifying both the total content of alkaloids and their ratio.Correspondence and reprints: Dipartimento di Biologia Evolutiva e Funzionale, Universitá degli Studi di Parma, Parco Area delle Scienze 11A, 43100 Parma, Italy.     

Diauxic Inhibition: Jacques Monod's Ignored Work

Journal of the History of Biology - Diauxie is at the origin of research that led Jacques Monod (1910–1976), François Jacob (1920–2013), and André Lwoff (1902–1994) to...     

Osservazioni ultrastrutturali sulle cellule di Leydig di Lacerta s. sicula Raf. in esemplari di gennaio e di maggio

Riassunto Gli autori descrivono gli aspetti ultrastrutturali delle cellule di Leydig di Lacerta s. sicula Raf`. in esemplari in letargo del mese di Gennaio (I gruppo) e in altri in periodo degli amori del mese di Maggio (II gruppo).Negli animali del primo gruppo le cellule di Leydig sono poco numerose, piccole, con scarso sviluppo del reticolo endoplasmatico, e mitocondri di dimensioni ridotte e prevalentemente con creste lamellari.Gli esemplari del secondo gruppo presentano cellule di Leydig numerose ed ipertrofiche con un R.E. liscio sviluppatissimo in forma di tubuli e di vescicole; i mitocondri sono numerosi, ipertrofici, con creste prevalentemente tubulari e con la parete spesso interrotta; sono presenti gocce lipidiche e vari lisosomi.La presenza dei caratteri ultrastrutturali propri delle cellule steroidogenetiche nelle cellule di Leydig degli esemplari di Lacerta s. sicula Raf`. in periodo degli amori, tende a confermare la loro partecipazione al metabolismo degli steroidi sessuali.

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On the fine structure of leydig cells in january and may specimens of Lacerta s. sicula Raf.

Summary In order to study the ultrastructure of the Leydig cells in the lizard Lacerta s. sicula Raf., the AA. examined two groups of animals, namely: January specimens in hibernation and May specimens in the mating period.In the animals of the first group, the Leydig cells were scarce, small and possessed a poorly developed E.R. and small mitochondria usually presenting laminar cristae.In the specimens of the second group the interstitial cells were large and possessed a very well developed smooth E.R. arranged in a system of anastomosing tubules and vesicles; the mitochondria were numerous and large, with prevailingly tubular cristae and often with a discontinuous wall. Lipid droplets and lysosomes were also present.The observation on the ultrastructure of the Leydig cells in May specimens of Lacerta s. sicula Raf`. seems to confirm the opinion that these elements participate in the metabolism of the sexual steroids; in fact they possess ultrastructural features that are typical of steroidogenetic cells.

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Lavoro eseguito con il contributo n.115.1121.1245. della Impresa di Endocrinologia del Consiglio Nazionale delle Ricerche, e svolto, per le osservazioni al M.E., presso il Centro di Studio di Microscopia Elettronica della Facoltà di Scienze dell'Università di Napoli.     

Micropropagation by explants ofGracilaria chilensisBird, McLachlan and Oliveira

Regeneration studies were carried out on four morphotypes ofGracilaria chilensisfound on the coast of Chile (36–41°S). Vegetative explants were obtained from sections of apical and medial origin and were cultured in five media: filtered autoclaved seawater (FAS), Provasoli enriched seawater (PES), PES + indole-3-acetic acid (PIAA), PES + kinetin (PK) and PK + IAA (PKIAA). Mature female gametophyte and tetrasporophyte explants were obtained from sections of medial origin and were cultured in FAS and PES. Bud differentiation and/or callus formation were the morphogenetic responses to the wounding of the explants in all culture media. Plantlet regeneration was obtained from excised buds and calluses cultured separately.     

Induction of Callus from the Marine Brown Alga Dictyosiphon foeniculaceus

A method for callus induction from an alga was established forthe first time. Callus tissues from the microthallus of themarine brown alga Dictyosiphon foeniculaceus were induced onASP 12-NTA medium of Provasoli (1963) supplemented with 3% mannitol,0.1% yeast extract and 1.5% agar. The addition of auxins andkinetin to the medium did not show any effect on the formationand growth of the callus. (Received November 24, 1981; Accepted March 30, 1982)     

Growth and survival performance of the gametophyte of Gigartina skottsbergii (Rhodophyta, Gigartinales) under defined nutrient conditions in laboratory culture

Gigartina skottsbergii is a commercially important carrageenan producer that has been suffering severe extraction pressure in Chile’s Magellan Region and Cape Horn Archipelago since 1998. In order to create baseline information for its cultivation and repopulation, we studied the effects of agricultural fertilizers on growth of G. skottsbergii early developmental stages. The culture media utilized were: a) seawater + Bayfoland, b) seawater + Superphosphate, c) seawater + Urea, d) seawater + Provasoli and e) seawater as a control. The culture conditions were: a) 12L:12D photoperiod; b) temperature 8 ± 1°C and c) irradiance at 45 μmol photons m⁻² s⁻¹. After 60 days, higher relative growth rates between treatments were observed; the treatments that included Bayfoland and Provasoli showed greater growth (382 ± 55 and 378 ± 50 μm, respectively,) compared to Superphosphate (88 ± 16 μm), control (78 ± 10 μm) and Urea (70 ± 11 μm) treatments, after 81 days. The Urea treatment and the control had inhibitory effects on G. skottsbergii germlings growth and survival, as evidenced by progressive loss of pigmentation and death after 60 days. These results showed that Bayfoland was an excellent alternative to develop cultures.     

Efficiency of the normal human diaphragm with hyperinflation.

We evaluated an index of diaphragm efficiency (Eff(di)), diaphragm power output (Wdi) relative to electrical activation, in five healthy adults during tidal breathing at usual end-expiratory lung volume (EELV) and diaphragm length (L(di ee)) and at shorter L(di ee) during hyperinflation with expiratory positive airway pressure (EPAP). Measurements were repeated with an inspiratory threshold (7.5 cmH(2)O) plus resistive (6.5 cmH(2)O.l(-1).s) load. Wdi was the product of mean inspiratory transdiaphragmatic pressure (DeltaPdi(mean)), diaphragm volume displacement measured fluoroscopically, and 1/inspiratory duration (Ti(-1)). Diaphragm activation, measured with esophageal electrodes, was quantified by computing root-mean-square values (RMS(di)). With EPAP, 1) EELV increased [mean r(2) = 0.91 (SD 0.01)]; 2) in four subjects, L(di ee) decreased [mean r(2) = 0.85 (SD 0.07)] and mean Eff(di) decreased 34% per 10% decrease in L(di ee) (P < 0.001); and 3) in one subject, gastric pressure at EELV increased two- to threefold, L(di ee) was unchanged or increased, and Eff(di) increased at two of four levels of EPAP (P < or = 0.006, ANOVA). Inspiratory loading increased Wdi (P = 0.003) and RMS(di) (P = 0.004) with no change in Eff(di) (P = 0.63) or its relationship with L(di ee). Eff(di) was more accurate in defining changes in L(di ee) [(true positives + true negatives)/total = 0.78 (SD 0.13)] than DeltaPdi(mean).RMS(di)(-1), RMS(di), or DeltaPdi(mean).Ti (all <0.7, P < or = 0.05, without load). Thus Eff(di) was principally a function of L(di ee) independent of inspiratory loading, behavior consistent with muscle force-length-velocity properties. We conclude that Eff(di), measured during tidal breathing and in the absence of expiratory muscle activity at EELV, is a valid and accurate measure of diaphragm contractile function.     

Ricerche Sulla Vegetazione Dell'etruria Marittima

Summary

The dates of foundation of the oldest university botanical gardens.

The dates of foundation of the oldest Botanical Gardens in Italy are not well known to the greatest part of the students of Botanical History.

Also today Ms. A. Guillaumin in his « Histoire de la Botanique en France (Paris, 1954) pag. 188» writes it was « Serenissima Repubblica Veneta » who founded the first Botanical Garden in 1533, whilst in that year only the chair of Bonafede had been constituded and the foundation of the Botanical Garden in Padoa happened later in 1545.

Really the most ancient Botanical Garden in the world is not that of Padoa, but that of Pisa.

Recently in the « Archivio di Stato » of Florence has been discovered by Fedeli a letter dated July 4 th 1545 written by Luca Ghini. From it it is clear that already a month before that date Luca Ghini was collecting plants to be coultivated in the academic garden of Pisa « for utility of students ».

The critical analysis of many papers by Luigi Anguillara allowe us to establish that Luca Ghini with the same Anguillara collected plants in the surreoundings of Pisa and on the Apuane Alps, from 1543 to 1544, and planted them in the academic garden of Pisa, which therefore must be considered the first Botanical Garden in the world, founded in the Summer 1543.

The second Botanical Garden in order of time is that of Padoa having been established by the « Senato Veneto » in 1545 and actually founded on July 7 th 1545 (de Visiani). The first director of Botanical Garden of Padoa was Luigi Anguillara after having left Pisa where he cooperated with Luca Ghini to found the Botanical Garden of Pisa.

Finally the third Botanical Garden is that of Florence (« Giardino dei Semplici ») founded as a dependance of that of Pisa by Luca Ghini, for school utility during the holyday, when the Florentine students remained at home. The date of its founding is December 1st 1545, as it appears from an an attorney document dated November 16th 1545 preserved in the « Archivio di Stato » of Florence (Volpi).

In conclusion the right chronology of the oldest University Botanical Gardens in the world is as follows:

1st: Pisa, Summer 1543

2nd: Padoa, July 7th 1545

3rd: Florence, December 1st 1545.     

“Uno,nessuno e centomila”: the different faces of the budding yeast kinetochore

“One, no one and one hundred thousand” is a masterpiece of Italian literature, written by Luigi Pirandello. The central theme is that in each individual there are multiple personalities, since one’s perception of one’s self differs from the view of others. As a consequence, a unique identity does not exist, but rather one hundred thousand. This concept can be very well applied to the kinetochore, one of the largest macromolecular complexes conserved in eukaryotes. The kinetochore is essential during cell division and fulfills different sophisticated functions, including linking chromosomes to spindle microtubules and delaying anaphase onset in case of incorrect bi-orientation. In order to perform these tasks, the kinetochore shapes its structure by recruiting different subunits, such as the components of the spindle assembly checkpoint (SAC) or the monopolin complex during meiosis. It also modifies its internal organization by rearranging intramolecular connections and acquiring a distinct identity at different time points of cell division. In this review, we describe recent insights into the changes in composition and configuration of the kinetochore in mitosis and meiosis, focusing on the kinetochore of Saccharomyces cerevisiae.     

The role of peridinin-chlorophyll a-proteins in the photosynthetic light adaption of the marine dinoflagellate,Glenodinium sp.

Summary The marine dinoflagellate, Glenodinium sp., was cultured at a series of light levels and growth, pigmentation, and photosynthetic rates were compared. Under decreasing light conditions, growth rates decreased, cellular chlorophyll a and peridinin content per cell increased, and maximum cellular photosynthetic rates remained unchanged. Pigmentation changes were related to alterations in cellular concentrations of a peridinin-chlorophyll a-protein and an unidentified chlorophyll a component of the chloroplast membrane. Maintenance of photosynthetic rates with decreased irradiance is interpreted as an increase in the number of pigment molecules in the light-harvesting antenna associated with the reaction centers of the photosynthetic apparatus, thus increasing the potential for photon capture for photosynthesis.Abbreviations ASP 7 medium see Provasoli, 1963 - PCP peridinin-chlorophyll a-protein - PSU photosynthetic unit - P-I photosynthesis-irradiance curve - TLC thin layer chromatography - A optical absorbance at a designated wavelength - SIO (F.T. Haxo) Scripps Institution of Oceanography collection This paper represents a portion of a thesis submitted in partial satisfaction of the requirements for the degree Doctor of Philosophy from the University of California, San Diego     

Design and Bioevaluation of Novel Hydrazide-Hydrazones Derived from 4-Acetyl-N-Substituted Benzenesulfonamide

Russian Journal of Bioorganic Chemistry - In this research, a series of hydrazine-hydrazone derivatives (Ia–g), (IIa–h) were synthesized to discover new antioxidant and...     

Luigi Galvani's path to animal electricity

In spite of the historical importance of the research that, in the second half of the 18th century, led Luigi Galvani (1737-1798) to lay down the foundation of modern electrophysiology, his scientific personality is largely misrepresented in science history and in popular imagery. He is still considered as a pioneer that by chance incurred some surprising experimental observations and was incapable of pursuing his research in a coherent way. In contrast with these views, Galvani was a high-standard scientist who succeeded, with the strength of experimental science, in demonstrating, in animals, electricity in a condition of disequilibrium between the interior and the exterior of excitable fibres. This electricity, called 'animal electricity', was deemed responsible for nerve conduction. By studying the scientific endeavours of Galvani, through his published and unpublished material, and by situating them in the historical context of the physiology of the Enlightenment, this paper attempts to trace the elusive and complex path that led Galvani to his extraordinary discovery.     

Effect of high nonexchangeable aluminium on nitrogen and phosphorus availability in a humus-rich acid forest soil

The effect of high nonexchangeable aluminum on availability of nitrogen (N) and phosphorus (P) was studied in a Cryptopodzolic soil (Cademario) derived from mica schist in southern Switzerland. The research involved a greenhouse pot experiment comparing growth of barley on soil samples of three soil layers (10- to 25-, 40- to 60- and 70- to 90 cm) of the Cademario profile, representing a range of Al and organic matter properties, with the 10- to 40 cm layer of a profile of an acidic brown earth (Haplumbrept), derived from cherty limestone. The experiment, which included four nutrient treatments [check, N₀ (PKS), P₀ (NKS) and full (NPKS)], lime and no lime treatments and four replicates, was supplemented by soil chemical analysis. Results showed that liming alone produced greater yield responses in the Cademario soil than N or P added singly or together. On unlimed soils, barley yield for check, N₀, and P₀ treatments showed a positive linear relation with exchangeable Ca of soils and a negative linear relation with organically-complexed Al. Failure of liming to influence P_av, especially when combined with P fertilization, suggests that P was quickly absorbed on highly active surfaces formed from initially exchangeable Al.This research is a cooperative effort of the Arizona Agricultural Experiment Stations, Journal Article No. 7100 and the Swiss Federal Institute for Forest, Snow and Landscape; it was supported by the National Science Foundation, USA, Grant No. INT-8304490, and the Swiss National Science Foundation, Grant No. 2.919-803.This research is a cooperative effort of the Arizona Agricultural Experiment Stations, Journal Article No. 7100 and the Swiss Federal Institute for Forest, Snow and Landscape; it was supported by the National Science Foundation, USA, Grant No. INT-8304490, and the Swiss National Science Foundation, Grant No. 2.919-803.     

THE GROWTH AND MORPHOLOGY OF THE SILICOFLAGELLATE DICTYOCHA FIBULA EHRENBERG IN CULTURE1,2

Dictyocha fibula was cultured in an enriched seawater medium from collections taken at Edmonds, Washington. The optimum temperature for growth is 10 C at salinity 24% and 160 ft-c illumination in Provasoli enriched seawater at the concentration of 7.5 ml/liter seawater. Average generation time is 49 hr. In addition to swimming cells with skeletons, swimming cells without skeletons and nonswimming coenocytes were observed in clonal cultures at 15 C.     

Plant Hormone Metabolome and Transcriptome Analysis of Dwarf and Wild-type Banana

Journal of Plant Growth Regulation - Gibberellin (GA), auxin (IAA) and brassinosteroid (BR) are indispensable in the process of plant growth and development. Currently, research on the regulatory...