Interactive Mechanisms of Supraspinal Sites of Opioid Analgesic Action: A Festschrift to Dr. Gavril W. Pasternak

Cellular and Molecular Neurobiology - Almost a half century of research has elaborated the discoveries of the central mechanisms governing the analgesic responses of opiates, including their...     

The WD40-Repeat Proteins NFC101 and NFC102 Regulate Different Aspects of Maize Development through Chromatin Modification

The maize (Zea mays) nucleosome remodeling factor complex component101 (nfc101) and nfc102 are putative paralogs encoding WD-repeat proteins with homology to plant and mammalian components of various chromatin modifying complexes. In this study, we generated transgenic lines with simultaneous nfc101 and nfc102 downregulation and analyzed phenotypic alterations, along with effects on RNA levels, the binding of NFC101/NFC102, and Rpd3-type histone deacetylases (HDACs), and histone modifications at selected targets. Direct NFC101/NFC102 binding and negative correlation with mRNA levels were observed for indeterminate1 (id1) and the florigen Zea mays CENTRORADIALIS8 (ZCN8), key activators of the floral transition. In addition, the abolition of NFC101/NFC102 association with repetitive sequences of different transposable elements (TEs) resulted in tissue-specific upregulation of nonpolyadenylated RNAs produced by these regions. All direct nfc101/nfc102 targets showed histone modification patterns linked to active chromatin in nfc101/nfc102 downregulation lines. However, different mechanisms may be involved because NFC101/NFC102 proteins mediate HDAC recruitment at id1 and TE repeats but not at ZCN8. These results, along with the pleiotropic effects observed in nfc101/nfc102 downregulation lines, suggest that NFC101 and NFC102 are components of distinct chromatin modifying complexes, which operate in different pathways and influence diverse aspects of maize development.     

A partnership project for a new Red List of the Italian Flora

Abstract

The IUCN Red Lists assessment provides an internationally accepted system to verify the extinction risk of species. Working Groups of the Italian Botanical Society have recently discussed the importance of producing a reliable list of species at the national level. This list could be the starting point for future in situ and ex situ plant conservation activities.     

Nuove segnalazioni di funghi entomogeni

Abstract

New records of entomogenous fungi. — New records of six entomogenous fungi, three Ascomycetes (Cordyceps lloydii Fawcett, C. memorabilis Ces., C. riverae Pacioni) and three Deuteromycetes (Akantomyces aranearum (Petch) Mains, Hirsutella citriformis Speare, Troglobiomyces guignardii (Maheu) Pacioni) are given. The new records allow to expand the known area of distribution of these parasites, to confirm the particular condition for fructification needed by some of them and to give new details for the less common species.     

Microtuboli in Cellule Parenchimatiche ed Epidermiche di Coleottile di Avena

Abstract

Microtubules in parenchyma and epidermis cells of avena coleoptile. — The fine structure of differentiating parenchyma and epidermis cells of the oat coleoptile, fixed in glutaraldehyde-osmium tetroxide, or glutaraldehyde-potassium permanganate, was investigated. Tubular structures have been observed aligned in the peripheral cytoplasm, between the cell wall and the plasma membrane, embedded in the cell wall and inside the tonoplast in the vacuoles.

The nature and function of these structures are yet unknown. Microtubular structures, localized beneath and above the plasma membrane, have been associated to the wall development; the function of the microtubules observed in vacuoles results, anyhow, of far problematic interpretation.     

Ricerche Sull'ultrastruttura della Parete Cellulare

Abstract

A study about the cell wall of AVENA coleoptile epidermis cells. — A new type of lamellae structures embedded in the outer periclinal wall of oat coleoptile epidermis cells has been observed. These structures are present more frequently in the inner non-cutinized portion of the cell wall; their orientation, most often parallel to the cell surface, follows a regular pattern. They are formed by alternate layers of electrontransparent and electron-dense bands. The thickness of these lamellar bodies is about 200–300 Å; their length is rather difficult to determinate. They are bounded by a 30–40 Å thick membrane; the inner compartment is formed by a central highly manganophilic zone 50–70 Å thick where several thin lamellae can be seen and by two lateral zones about 40–50 Å in thickness.

Embedded in the cutinized portion of the wall some elliptical bodies have also been observed, surroundedd by a single membrane, 20 Å in thickness. The interior of these bodies shows thin lamellae enclosed in an electron-transparent stroma.

In experimental conditions unfavourable to growth, the frequency of these structures falls greatly. When the cell distension comes to end, their aspect undergoes deep changes. It is proposed in this paper that these new structures are involved in cell wall growth and development.     

Notes on the Laboulbeniales (Ascomycota) parasitic on Diptera from Portugal and other countries

Eighteen species of Stigmatomyces are reported for the first time from continental Portugal and/or from the Azores. These are Stigmatomyces asteiae W. Rossi et Cesari, Stigmatomyces athyroglossae W. Rossi et Cesari, Stigmatomycescanzonerii W. Rossi et Cesari, Stigmatomyces ceratophorus Whisler, Stigmatomyces constrictus Thaxt., Stigmatomyces crassicollis Thaxt., Stigmatomyces divergatus Thaxt., Stigmatomyces discocerinae Thaxt., Stigmatomyces ensinae Thaxt., Stigmatomyces cf. ephydrae L. Mercier et R. A. Poiss., Stigmatomycesgeomyzae W. Rossi et Cesari, Stigmatomyces limnophorae Thaxt., Stigmatomyces majewskii H. L. Dainat, Manier et Balazuc, Stigmatomyces papuanus Thaxt., Stigmatomycesplatensis Speg., Stigmatomyces ptylomyiae Thaxt. and Stigmatomyces purpureus Thaxt., Stigmatomyces rugosus Thaxt. New records of these species are also reported from Australia, Canada, Canary Islands (Spain), Costa Rica, Cuba, Ecuador, Finland, Germany, Great Britain, Greece, Kenya, Hungary, Israel, Kyrgyzstan, Lebanon, Morocco, Saudi Arabia, Sierra Leone, Taiwan, Thailand, Turkey, Uganda, United Arab Emirates, USA, Yemen and Zimbabwe. The new records increase, sometimes considerably, information about distribution of these parasites. Two synonymies are also established: Stigmatomyces autriquei Balazuc = Stigmatomyces ensinae Thaxt.; Stigmatomyces psilopae Thaxt. var. camarguensis H. L. Dainat et J. Dainat = S. rugosus Thaxt.     

Ricerche Sull'infrastruttura del Coleottile di Avena

Abstract

Researches on ultrastructure of Avena coleoptile. 3. The sieve elements. — A study on the ultrastructural organization of the mature sieve elements of Avena coleoptile has been carried out. Data suggest that functional phloem tubes are alive and remain alive until they are working. Judging on morphological basis, the metabolic activity of sieve elements should be of peculiar type and low in comparison to that of the companion cells. In fact the cytoplasm is located in a narrow parietal strand, mitochondria, Golgi apparatus and endoplasmic reticulum are present, but they appear very modified; plastids and nucleus are absent. The cytoplasm is bounded externally by a normal plasmalemma, whilst the vacuole has no visible limits: a tonoplast is, therefore not identifiable.

The strands connecting the superimposed sieve elements with one another through the sieve plate result to be made by a double membrane system very similar to the endoplasmic reticulum, which we believe to realize cytoplasmic continuity between phloem tubes.

The data reported are more favorable to the existence in the sieve tubes of an active mechanism of translocation of organic solutes than a passive mass-flow.

The collaboration of companion cells in the translocation mechanism has been discussed.     

Iron Release in Erythrocytes and Plasma Non Protein-bound Iron in Hypoxic and Non Hypoxic Newborns

Iron is released in a desferrioxamine (DFO)-chelatable form (DCI) when erythrocytes are challenged by an oxidative stress. In &#103 -thalassemic erythrocytes, both DCI content and release (after aerobic incubation for 24 h) are increased and correlated with the fetal hemoglobin (HbF) levels. Since erythrocytes from newborns have an extremely high content of HbF and are exposed to conditions of oxidative stress, the release of iron in these erythrocytes was investigated. The erythrocyte DCI content was increased in preterm but not in term newborns as compared to adults, while the release was increased in both preterm and term erythrocytes. The level of plasma non protein-bound iron (NPBI), which was not detectable in adults, was much higher in preterm than in term newborns. When term plus preterm newborns were divided in two groups, normoxic and hypoxic, according to cord blood pH, it was found that both iron release and NBPI were markedly higher in the hypoxic newborns compared to normoxic ones. Similar results were also obtained when the preterm and term infants were considered separately on the basis of cord blood pH. Therefore, iron release and NPBI are higher when conditions of hypoxia occur. In fact, when the values for iron release and NPBI were separately plotted against cord blood pH values, significant negative correlations were seen in both cases. NPBI was correlated with iron release seen in all the newborns and a significant part of the released iron could be recovered into the incubation medium at the end of the incubation.     

Oxidative stress,erythrocyte ageing and plasma non-protein-bound iron in diabetic patients

Increased oxidative stress and decreased life span of erythrocytes (RBCs) are repeatedly reported in diabetes. In the aim to elucidate the mechanism of the latter, i.e. the events leading to erythrocyte ageing, this study determined in RBCs from diabetic patients iron release in a free desferrioxamine-chelatable form (DCI), methemoglobin (MetHb) formation, binding of autologous IgG to membrane proteins and in plasma non-protein-bound iron (NPBI), F₂-Isoprostanes (F₂-IsoPs) and advanced oxidation protein products (AOPP). DCI and MetHb were higher in diabetic RBCs than in controls and autologous IgG binding occurred in a much higher percentage of diabetic patients than controls. A significant correlation between DCI and IgG binding was found in diabetic RBCs. Plasma NPBI, esterified F₂-IsoPs and AOPP were higher in diabetic patients and a significant correlation was found between plasma NPBI and intra-erythrocyte DCI. The increased DCI and autologous IgG binding appear to be important factors in the accelerated removal of RBCs from the blood stream in diabetes and the increase in plasma NPBI could play an important role in the increased oxidative stress.