Controlled release of adeno-associated virus from alginate hydrogel microbeads with enhanced sensitivity to ultrasound

Adeno-associated virus (AAV)-based gene therapy holds promise as a fundamental treatment for genetic disorders. For clinical applications, it is necessary to control AAV release timing to avoid an immune response to AAV. Here we propose an ultrasound (US)-triggered on-demand AAV release system using alginate hydrogel microbeads (AHMs) with a release enhancer. By using a centrifuge-based microdroplet shooting device, the AHMs encapsulating AAV with tungsten microparticles (W-MPs) are fabricated. Since W-MPs work as release enhancers, the AHMs have high sensitivity to the US with localized variation in acoustic impedance for improving the release of AAV. Furthermore, AHMs were coated with poly-l -lysine (PLL) to adjust the release of AAV. By applying US to the AAV encapsulating AHMs with W-MPs, the AAV was released on demand, and gene transfection to cells by AAV was confirmed without loss of AAV activity. This proposed US-triggered AAV release system expands methodological possibilities in gene therapy.     

Phylogeography of the temperate grassland plant Tephroseris kirilowii (Asteraceae) inferred from multiplexed inter-simple sequence repeat genotyping by sequencing (MIG-seq) data

Journal of Plant Research - A group of temperate grassland plant species termed the “Mansen elements” occurs in Japan and is widely distributed in the grasslands of continental East...     

Spermatogenesis in Animals as Revealed by Electron Microscopy : VI. Researches on the Spermatozoon-Dimorphism in a Pond Snail, Cipangopaludina malleata

This paper reports an electron microscope study of typical and atypical spermatogenesis in the pond snail, Cipangopaludina malteata. In the typical spermatid the nucleus undergoes profound changes as development proceeds, affecting both its form and internal fine structure. A large number of roughly parallel, dense filaments, arranged along the long axis of the nucleus, fuse with each other to form in the end the homogeneous helical body characteristic of the head of the adult spermatozoa. The nebenkern is apparently mitochondrial in nature and, in its early development, is similar to that of insects except that it appears as a double structure from the beginning. As differentiation proceeds, the mitochondria lose their membranes, and the residual, now denuded cristae, reorganize to give a parallel radial arrangement. In the last stages of development, the nebenkern derivations become applied to the sheath of the middle piece in a compact helical fashion. In the development of the atypical spermatozoa, the nucleus fails to differentiate and simply shrinks in volume until only a remnant, devoid of DNA, is left. The cytoplasm shows numerous vesicles containing small Feulgen-positive bodies, 80 to 130 mµ in diameter. These vesicles plus contents increase in number as spermatogenesis proceeds. The "head" structure of the atypical spermatozoa consists of a bundle (7 to 17) of tail flagella, each with a centriole at its anterior end. The end-piece of the atypical form appears brush-like and is made up of the free ends of the several flagella.     

1H-, 13C-, and 113Cd-nmr study of the Cd(II) complex of a blocked peptide,Z-Cys-Ala-Pro-His-OMe,in organic solvents

The Cd(II) complex of a peptide, Z-Cys-Ala-Pro-His-OMe was prepared and characterized by absorption, CD, ¹H-, ¹³C-, and ¹¹³Cd-nmr, and nuclear Overhauser effect spectroscopy (NOESY) spectra to show the coordination of cysteine thiolate and histidine imizazole to Cd(II) ion. The NOESY spectra in dimethyl formamide showed that the cysteine residue was in proximity to the histidine residue. These results reveal the dictation of Z-Cys-Ala-Pro-His-OMe to Cd(II) ion in solution. Temperature-dependent dissociation equilibrium of histidine imidazole in solution was observed in this complex. Structural features of the chelating peptide are discussed. © 1995 John Wiley & Sons, Inc.     

Alcohol and aldehyde dehydrogenase genotypes and drinking behavior of Chinese living in Shanghai

Alcohol dehydrogenase (ADH) and aldehyde dehydrogenase (ALDH), the principal enzymes responsible for oxidative metabolism of ethanol, exist in multiple, genetically determined molecular forms. Widely different kinetic properties in some of these isozymes account for the individual differences in alcohol sensitivity. In this study we used the polymerase chain reaction/restriction fragment length polymorphism method to determine the genotypes of the ADH2 and ALDH2 loci of alcoholic and nonalcoholic Chinese living in Shanghai. We also investigated the subjects' drinking patterns by means of semistructured interviews. The alcoholics had significantly lower frequencies of the ADH2² and ALDH2² alleles than did the nonalcoholics, suggesting the inhibitory effects of these alleles for the development of alcoholism. In the nonalcoholic subjects, ADH2² had little, if any, effect, despite the significant effect of the ALDH2² allele in decreasing the alcohol consumption of the individual. Taken together, these results fit the proposed hypothesis for the development of alcoholism, i.e., drinking behavior is greatly influenced by the individual's gentoypes of alcohol-metabolizing enzymes, and the risk of becoming alcoholic is proportionate with the ethanol consumption of the individual.     

High-resolution solution structure of siamycin II: Novel amphipathic character of a 21-residue peptide that inhibits HIV fusion

Summary The 21-amino acid peptides siamycin II (BMY-29303) and siamycin I (BMY-29304), derived from Streptomyces strains AA3891 and AA6532, respectively, have been found to inhibit HIV-1 fusion and viral replication in cell culture. The primary sequence of siamycin II is CLGIGSCNDFAGCGYAIVCFW. Siamycin I differs by only one amino acid; it has a valine residue at position 4. In both peptides, disulfide bonds link Cys¹ with Cys¹³ and Cys⁷ with Cys¹⁹, and the side chain of Asp⁹ forms an amide bond with the N-terminus. Siamycin II, when dissolved in a 50:50 mixture of DMSO and H₂O, yields NOESY spectra with exceptional numbers of cross peaks for a peptide of this size. We have used 335 NOE distance constraints and 13 dihedral angle constraints to generate an ensemble of 30 siamycin II structures; these have average backbone atom and all heavy atom rmsd values to the mean coordinates of 0.24 and 0.52 Å, respectively. The peptide displays an unusual wedge-shaped structure, with one face being predominantly hydrophobic and the other being predominantly hydrophilic. Chemical shift and NOE data show that the siamycin I structure is essentially identical to siamycin II. These peptides may act by preventing oligomerization of the HIV transmembrane glycoprotein gp41, or by interfering with interactions between gp41 and the envelope glycoprotein gp120, the cell membrane or membrane-bound proteins [Frèchet, D. et al. (1994) Biochemistry, 33, 42–50]. The amphipathic nature of siamycin II and siamycin I suggests that a polar (or apolar) site on the target protein may be masked by the apolar (or polar) face of the peptide upon peptide/protein complexation.Abbreviations ABNR adopted basis Newton Raphson - AIDS acquired immunodeficiency syndrome - CW continuous wave - DMSO dimethylsulfoxide - DQF-COSY two-dimensional double-quantum-filtered correlation spectroscopy - HIV human immunodeficiency virus - HSQC heteronuclear single-quantum coherence - NOE nuclear Overhauser enhancement - NOESY two-dimensional nuclear Overhauser enhancement spectroscopy - ppm parts per million - P.E.-COSY two-dimensional primitive exclusive correlation spectroscopy - REDAC redundant dihedral angle constraint - rf radio frequency - rmsd root-mean-square difference - SIV simian immunodeficiency virus - sw spectral width - _m mixing time - TOCSY two-dimensional total correlation spectroscopy - TSP trimethylsilyl-2,2,3,3-²H₄-propionate - 2D two-dimensional     

Bacterial Plasmids in Antarctic Natural Microbial Assemblages

Samples of psychrophilic and psychrotrophic bacteria were collected from sea ice, seawater, sediments, and benthic or ice-associated animals in McMurdo Sound, Antarctica. A total of 155 strains were isolated and tested for the presence of plasmids by DNA agarose gel electrophoresis. Thirty-one percent of the isolates carried at least one kind of plasmid. Bacterial isolates taken from sediments showed the highest plasmid incidence (42%), and isolates from seawater showed the lowest plasmid incidence (20%). Plasmids were significantly more frequent in the strains which had been first isolated from low-nutrient media (46%) than in the strains which had been isolated from high-nutrient media (25%). Multiple forms of plasmids were observed in two-thirds of the plasmid-carrying strains. A majority of the plasmids detected were estimated to have a mass of 10 megadaltons or less. Among 48 plasmid-carrying strains, 7 showed antibiotic resistance. It is concluded that bacterial plasmids are ubiquitous in natural microbial assemblages of the pristine marine ecosystem of Antarctica.