Bacterial nonspecific acid phosphohydrolases: physiology, evolution and use as tools in microbial biotechnology

Bacterial nonspecific acid phosphohydrolases (NSAPs) are secreted enzymes, produced as soluble periplasmic proteins or as membrane-bound lipoproteins, that are usually able to dephosphorylate a broad array of structurally unrelated substrates and exhibit optimal catalytic activity at acidic to neutral pH values. Bacterial NSAPs are monomeric or oligomeric proteins containing polypeptide components with an M _r of 25 – 30 kDa. On the basis of amino acid sequence relatedness, three different molecular families of NSAPs can be distinguished, indicated as molecular class A, B and C, respectively. Members of each class share some common biophysical and functional features, but may also exhibit functional differences. NSAPs have been detected in several microbial taxa, and enzymes of different classes can be produced by the same bacterial species. Structural and phyletic relationships exist among the various bacterial NSAPs and some other bacterial and eucaryotic phosphohydrolases. Current knowledge on bacterial NSAPs is reviewed, together with analytical tools that may be useful for their characterization. An overview is also presented concerning the use of bacterial NSAPs in biotechnology. Received 21 November 1997; received after revision 10 March 1998; accepted 10 March 1998     

Cell-penetrating peptides: tools for intracellular delivery of therapeutics

The main problem of therapeutic efficiency lies in the crossing of cellular membranes. Therefore, significant effort is being made to develop agents which can cross these barriers and deliver therapeutic agents into cellular compartments. In recent years, a large amount of data on the use of peptides as delivery agents has accumulated. Several groups have published the first positive results using peptides for the delivery of therapeutic agents in relevant animal models. These peptides, called cell-penetrating peptides (CPPs), are short peptides (fewer than 30 residues) with a net positive charge and acting in a receptor- and energy-independent manner. Here, we give an extensive review of peptide-mediated delivery systems and discuss their applications, with particular focus on the mechanisms leading to cellular internalization.Received 14 March 2005; received after revision 25 April 2005; accepted 28 April 2005     

New technique for movement analysis: application to biological systems

A new system for motion analysis is described. Modulation of light intensity of an organism's movement over an opaque and transparent checkerboard grid is monitored by a photocell. The photocell's output is proportional to the organism's amplitude and frequency of movement. This output is analyzed by a continuous interval dot display and spectrum analysis. The system was tested by analyzing the activity of 4 Drosophila strains which are known to differ in their activity. General applicability of the system is discussed.     

New technique for movement analysis: Application to biological systems

Summary A new system for motion analysis is described. Modulation of light intensity by an organism's movement over an opaque and transparent checkerboard grid is monitored by a photocell. The photocell's output is proportional to the organism's amplitude and frequency of movement. This output is analyzed by a continuous interval dot display and spectral analysis. The system was tested by analyzing the activity of 4 Drosophila strains which are known to differ in their activity. General applicability of the system is discussed.This research was supported by a grant from the United States-Israel Binational. Science Foundation (BSF), Jerusalem, Israel.     

Nanoparticle-based drug delivery: case studies for cancer and cardiovascular applications

Nanoparticles (NPs) comprised of nanoengineered complexes are providing new opportunities for enabling targeted delivery of a range of therapeutics and combinations. A range of functionalities can be included within a nanoparticle complex, including surface chemistry that allows attachment of cell-specific ligands for targeted delivery, surface coatings to increase circulation times for enhanced bioavailability, specific materials on the surface or in the nanoparticle core that enable storage of a therapeutic cargo until the target site is reached, and materials sensitive to local or remote actuation cues that allow controlled delivery of therapeutics to the target cells. However, despite the potential benefits of NPs as smart drug delivery and diagnostic systems, much research is still required to evaluate potential toxicity issues related to the chemical properties of NP materials, as well as their size and shape. The need to validate each NP for safety and efficacy with each therapeutic compound or combination of therapeutics is an enormous challenge, which forces industry to focus mainly on those nanoparticle materials where data on safety and efficacy already exists, i.e., predominantly polymer NPs. However, the enhanced functionality affordable by inclusion of metallic materials as part of nanoengineered particles provides a wealth of new opportunity for innovation and new, more effective, and safer therapeutics for applications such as cancer and cardiovascular diseases, which require selective targeting of the therapeutic to maximize effectiveness while avoiding adverse effects on non-target tissues.     

MicroRNAs in myocardial ischemia: identifying new targets and tools for treating heart disease. New frontiers for miR-medicine

MicroRNAs (miRNAs) are natural, single-stranded, small RNA molecules which subtly control gene expression. Several studies indicate that specific miRNAs can regulate heart function both in development and disease. Despite prevention programs and new therapeutic agents, cardiovascular disease remains the main cause of death in developed countries. The elevated number of heart failure episodes is mostly due to myocardial infarction (MI). An increasing number of studies have been carried out reporting changes in miRNAs gene expression and exploring their role in MI and heart failure. In this review, we furnish a critical analysis of where the frontier of knowledge has arrived in the fields of basic and translational research on miRNAs in cardiac ischemia. We first summarize the basal information on miRNA biology and regulation, especially concentrating on the feedback loops which control cardiac-enriched miRNAs. A focus on the role of miRNAs in the pathogenesis of myocardial ischemia and in the attenuation of injury is presented. Particular attention is given to cardiomyocyte death (apoptosis and necrosis), fibrosis, neovascularization, and heart failure. Then, we address the potential of miR-diagnosis (miRNAs as disease biomarkers) and miR-drugs (miRNAs as therapeutic targets) for cardiac ischemia and heart failure. Finally, we evaluate the use of miRNAs in the emerging field of regenerative medicine.     

Bacterial localization: The use of an autographic method for the study of infectious processes in mice

Riassunto Il metodo autografico è stato impiegato per la valutazione della distribuzione dei germi. Sezioni sagittali complete di topi precedentemente infettati sono state incubate e i germi vivi sono stati rivelati mediante colorazione vitale con trifeniltetrazolio. Le risultanti mappe dettagliate della distribuzione batterica permettono di penetrare il meccanismo dei processi difensivi dell'ospite e le proprietà invasive del germe.     

Decision-making at the surface of the intact or barrier disrupted skin: potential applications for vaccination or therapy

The skin is a highly accessible organ and constitutes an active immunological site. Both these properties make this surface an attractive route for what promises to be a cost-effective, simple, practical and needle-free delivery of vaccines and immunomodulators. Less obvious is the fact that the state of the skin barrier can influence quantitative and qualitative aspects of antigen-specific immune responses. The everyday decision-making at the skin epithelium concerns the choice between the induction of an immune response and the establishment of a state of non-responsiveness (tolerance). This decision is influenced by various factors such as the dose, the route (intact vs barrier-disrupted skin), the cytokine microenvironment and the nature of the antigenic stimulus. By increasing our understanding of how immune responses are regulated in the epidermis we can envisage the development of immunisation protocols aimed at eliciting a protective immune response or inducing tolerance, with direct applications to preventive or therapeutic vaccination, respectively.Received 29 November 2004; received after revision 2 February 2005; accepted 22 February 2005     

Two mechanisms in the biological clock ofPieris brassicae L.: an oscillator for diapause induction; an hour-glass for diapause termination

Summary Resonance experiments for photoperiodic termination of pupal diapause demonstrated thatPieris brassicae uses a night-measuring hour-glass mechanism. In previous work the same resonance technique for diapause induction revealed that photoperiodic time-measurement is a function of the circadian system. For the first time in a living organism it has been shown that the biological clock operates by means of an oscillator for photoperiodic onset of a phenomenon and according to an hour-glass system for photoperiodic termination.     

A new biological activity for the neuropeptide FMRFamide: experimental evidence for a secretagogue effect on amylase secretion in the scallopPecten maximus

FMR Famide immunoreactivity in the digestive tract of the bivalve molluscPecten maximus was investigated by immunocytochemistry. Positive FMRFamide-like immunoreactivity was detected in nerve fibres in close contact with exocrine α amylase secreting cells. Physiological studies on enzymatically dissociated cells of the stomach-digestive gland complex demonstrated the involvement of FMR Famide and analogues in the control of α amylase release from the cells. The FMRF Famide-induced secretion was shown to be time- and dose-dependent. In contrast to most naturally occurring vertebrate secretagogues which are hormones, FMRFamide appears to work in our in vitro system as a paracrine factor.     

Analogical reflection as a source for the science of life: Kant and the possibility of the biological sciences

In contrast to the previously widespread view that Kant's work was largely in dialogue with the physical sciences, recent scholarship has highlighted Kant's interest in and contributions to the life sciences. Scholars are now investigating the extent to which Kant appealed to and incorporated insights from the life sciences and considering the ways he may have contributed to a new conception of living beings. The scholarship remains, however, divided in its interest: historians of science are concerned with the content of Kant's claims, and the ways in which they may or may not have contributed to the emerging science of life, while historians of philosophy focus on the systematic justifications for Kant's claims, e.g., the methodological and theoretical underpinnings of Kant's statement that living beings are mechanically inexplicable. My aim in this paper is to bring together these two strands of scholarship into dialogue by showing how Kant's methodological concerns (specifically, his notion of reflective judgment) contributed to his conception of living beings and to the ontological concern with life as a distinctive object of study. I argue that although Kant's explicit statement was that biology could not be a science, his implicit and more fundamental claim was that the study of living beings necessitates a distinctive mode of thought, a mode that is essentially analogical. I consider the implications of this view, and argue that it is by developing a new methodology for grasping organized beings that Kant makes his most important contribution to the new science of life.     

Immunoassay for lysine8-vasopressin (LVP): Comparison of biological and immunological activity of lysine-vasopressin and some of its synthetic analogues

Résumé Ces résultats suggèrent d'une part que¹²⁵I-LVP monoiodée a peu d'activité antidiurétique, d'autre part que le noyau phénylalanine en position 3 est essentiel pour la liaison de l'antigène à l'anticorps et que les sites immunologiques et biologiques de l'hormone sont différents.

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Acknowledgments. We wish to thank ProfessorS. Jard (Collège de France, 11, place Marcellin Berthelot, Paris 5^eme) for his valuable advice in connection with this work. LVP analogues were generously supplied by Dr.R. A. Boissonnas of Sandoz Pharmaceuticals.