As integrated culture system for outdoor production of microalgae and cyanobacteria

Cultivation of microalgae in closed photobioreactors suffers from high temperatures, whereas in open raceway ponds the optimal temperature is seldom reached. With an integrated device coupling a raceway pond with a suitably sized and positioned closed system (alveolar panel), the heat accumulated in the panel was efficiently transferred to the pond and a near-optimum temperature regimen for Arthrospira platensis was maintained, with no need for any additional cooling device. The productivity obtained in the integrated system was higher than the sum of the productivities (g reactor⁻¹ day⁻¹) of the pond and panel systems operating separately. This revised version was published online in September 2006 with corrections to the Cover Date.     

Directional asymmetry and correlation of tail injury with left-side dominance occur in Serpentes (Sauropsida)

Recent evidence on directional asymmetry (DA) in species of the paraphyletic assemblage “Lacertilia” indicates a possible biological significance of this phenomenon, and we tested its occurrence in Serpentes by examining bilateral morphological characters, such as the numbers of supralabial and infralabial scutes and the diameter of the eyes, on both sides of museum specimens of seven species: Coronella austriaca, Elaphe longissima, Hierophis viridiflavus, Natrix natrix, Natrix tessellata, Platyceps saharicus, and Vipera aspis. Significant DA (not antisymmetry) occurred in at least one sex of four species and in two characters: H. viridiflavus—the number of infralabial scutes in males; N. tessellata—the diameter of the eyes in males; P. saharicus—the number of infralabial scutes in males and the diameter of the eyes in females; and V. aspis—the number of infralabial scutes in the pooled sexes. In N. tessellata and P. saharicus the DA varied geographically. Rank correlation between the DA of different characters, positive or negative, was significant in one character pair in each of three species. In the largest sample (N. tessellata males from the Levant), tail injury correlated with morphological left-dominant asymmetry (a greater number on the left) of infralabial scutes. Four of ten morphologically left-dominant males, but only 1 of 37 symmetrical or right-dominant males, had an injured tail. The syndrome of morphological DA with functional handicap may be genotypical or phenotypical. Our results support three earlier conclusions: bilateral characters should be examined on both sides of an animal; asymmetry should be analyzed separately in each sex; and the accident proneness of left-handed Homo sapiens merits re-evaluation in view of the apparently wide-spread accident proneness in left-biased Sauropsida (exclusive of Aves).     

Membrane glycopeptides from old and young human erythrocytes (Short Communication)

Glycopeptides were extracted by papain digestion from old and young human erythrocyte membranes and fractionated on DEAE-Sephadex A-25. Chemical characterization of the unfractionated samples and of the main peak eluted from the column indicates that glycoproteins of the erythrocyte membrane undergo significant decreases in sialic acid and galactosamine content with aging.     

Intranasal delivery of mesenchymal stem cell secretome repairs the brain of Alzheimer’s mice

The multiplicity of systems affected in Alzheimer’s disease (AD) brains calls for multi-target therapies. Although mesenchymal stem cells (MSC) are promising candidates, their clinical application is limited because of risks related to their direct implantation in the host. This could be overcome by exploiting their paracrine action. We herein demonstrate that in vivo systemic administration of secretome collected from MSC exposed in vitro to AD mouse brain homogenates (MSC-CS), fully replicates the cell-mediated neuroreparative effects in APP/PS1 AD mice. We found a complete but transient memory recovery by 7 days, which vanished by 14 days, after a single MSC-CS intravenous administration in 12-month or 22–24-month-old mice. Treatment significantly reduced plaque load, microglia activation, and expression of cytokines in astrocytes in younger, but not aged, mice at 7 days. To optimize efficacy, we established a sustained treatment protocol in aged mice through intranasal route. Once-weekly intranasal administration of MSC-CS induced persistent memory recovery, with dramatic reduction of plaques surrounded by a lower density of β-amyloid oligomers. Gliosis and the phagocytic marker CD68 were decreased. We found a higher neuronal density in cortex and hippocampus, associated with a reduction in hippocampal shrinkage and a longer lifespan indicating healthier conditions of MSC-CS-treated compared to vehicle-treated APP/PS1 mice. Our data prove that MSC-CS displays a great multi-level therapeutic potential, and lay the foundation for identifying the therapeutic secretome bioreactors leading to the development of an efficacious multi-reparative cocktail drug, towards abrogating the need for MSC implantation and risks related to their direct use.Subject terms: Neural ageing, Neurological disorders, Inflammation     

Skin potential and EMG changes induced by cutaneous electrical stimulation. II. Subjects with reflex sympathetic dystrophies.

In a group of patients suffering from reflex sympathetic dystrophies, the skin potential and EMG responses induced by electrical stimuli applied to the skin were recorded in the four limbs in order to study somato-sympathetic and somato-motor reflexes. In most patients, the amplitude, delay and shape of the cutaneous responses as well as the pattern of the EMG responses were different from those observed in normal subjects. In particular, it was possible to correlate the pattern of the cutaneous and muscular responses with the severity of the disease. The cutaneous sensory thresholds to electrical stimuli (tactile, tingling and pain threshold) showed different values in the dystrophic and in the contralateral limb. In all patients, a block of the sympathetic chain ipsilateral to the dystrophic limb was performed with local anesthetics. 1 h after the block, the cutaneous responses disappeared not only in the blocked limb but also in the contralateral limb. 48 h after the block, muscular and cutaneous responses as well as sensory thresholds showed a pattern similar to that observed in normal subjects. These findings show that the sympathetic block provides a resetting of the sensory thresholds and reflexes.     

Oviposition site selection by the bromeliad-dweller harvestman <Emphasis Type="Italic">Bourguyia</Emphasis><Emphasis Type="Italic">hamata</Emphasis> (Arachnida: Opiliones)

Bourguyia hamata females oviposit almost exclusively inside the rosette formed by the curled leaves of the epiphytic bromeliad Aechmea nudicaulis. We investigated whether the architecture of the individual bromeliads influences oviposition site selection by this harvestman species. We collected data on the presence of clutches inside bromeliads, rosette length, rosette slope in relation to tree trunks, and the amount of debris inside the rosette. Additionally, we measured the water volume inside the rosettes as well as the variation in the humidity inside and outside bromeliads with long and short rosettes. Longer rosettes were preferred as oviposition site possibly because they accumulate more water and maintain lower internal humidity variation than the external environment. Although the slope of the rosettes did not influence the occurrence of oviposition, the probability of debris accumulation inside the rosettes increased with their slope, and the frequency of clutches was greater in bromeliads with small amounts of debris. A field experiment showed that bromeliads with water inside the rosette were more frequently used as oviposition sites than bromeliads without water. In conclusion, females oviposit predominantly in bromeliads that accumulate more water and have small amounts of debris inside the rosettes, probably because these characteristics promote a more adequate microhabitat for egg development.     

A mathematical model for drug administration by using the phagocytosis of red blood cells

 A mathematical model for the delivery of drug directly to the macrophages by using the phagocytosis of senescent red blood cells is proposed. The model is based on the following assumption: At time t=0 a preassigned red blood cell population n(0, a)=φ(a), a>0, loaded by the drug, is injected in the blood circulation. Among the cells of that population only those with an age a≧ā (ā=120 days) will be phagocytosed by macrophages. Of course, the lifetime of the drug must be higher than ā. Within the red blood cells it cannot be metabolized, neither can it diffuse through their membranes. The emphasis of the paper is on the mathematical properties and on the formulation of the control problem. Received 15 December 1994; received in revised form 20 July 1995     

Chloroplast-derived photo-oxidative stress causes changes in H2O2 and EGSH in other subcellular compartments

Metabolic fluctuations in chloroplasts and mitochondria can trigger retrograde signals to modify nuclear gene expression. Mobile signals likely to be involved are reactive oxygen species (ROS), which can operate protein redox switches by oxidation of specific cysteine residues. Redox buffers, such as the highly reduced glutathione pool, serve as reservoirs of reducing power for several ROS-scavenging and ROS-induced damage repair pathways. Formation of glutathione disulfide and a shift of the glutathione redox potential (E_GSH) toward less negative values is considered as hallmark of several stress conditions. Here we used the herbicide methyl viologen (MV) to generate ROS locally in chloroplasts of intact Arabidopsis (Arabidopsis thaliana) seedlings and recorded dynamic changes in E_GSH and H₂O₂ levels with the genetically encoded biosensors Grx1-roGFP2 (for E_GSH) and roGFP2-Orp1 (for H₂O₂) targeted to chloroplasts, the cytosol, or mitochondria. Treatment of seedlings with MV caused rapid oxidation in chloroplasts and, subsequently, in the cytosol and mitochondria. MV-induced oxidation was significantly boosted by illumination with actinic light, and largely abolished by inhibitors of photosynthetic electron transport. MV also induced autonomous oxidation in the mitochondrial matrix in an electron transport chain activity-dependent manner that was milder than the oxidation triggered in chloroplasts by the combination of MV and light. In vivo redox biosensing resolves the spatiotemporal dynamics of compartmental responses to local ROS generation and provides a basis for understanding how compartment-specific redox dynamics might operate in retrograde signaling and stress acclimation in plants.

Methyl viologen-induced photo-oxidative stress increases hydrogen peroxide and oxidation of glutathione in chloroplasts, cytosol, and mitochondria, as well as autonomous oxidation in mitochondria.     

Preserved ascomatal and other fungal structures on the remains of a ninth century Longobard abbess exhumed from a Monastery in Pavia,Italy

Auxarthron californiense, Mixotrichum aeruginosum, Oncocladium flavum and Chaetomium elatum were recognized on the basis of ascomatal structures on the remains of a Longobard abbess who died in the IX century A.D. These fungi, which had remained isolated in a crypt of the S. Felice Monastery of Pavia for almost 1000 years, are phenotypically identical to the type specimens. The occurrence of these fungi and their ecological role are discussed. This revised version was published online in August 2006 with corrections to the Cover Date.