An ending is a new beginning: Transcription termination supports re-initiation

Comment on: Mapendano CK, et al. Mol Cell 2010; 40:410-22.     

The beginning of a new era in tissue expansion: self-filling osmotic tissue expander--four-year clinical experience

The osmotic tissue expander is a new device made of a hydrogel expanding skin that does not require external fillings. Once implanted, it absorbs body fluids, which leads to a gradual swelling of the device. The swelling phase is completed in 6 to 8 weeks and results in skin gain. Different shapes and sizes are available, and the devices can be used in almost every area of the body. Over a 4-year period, the osmotic tissue expander was used in 58 patients in different areas of the body. A round osmotic tissue expander was mainly used in breast reconstruction, and a rectangular expander was used for defect coverage after excision (i.e., of scars and tumors). The mean age of the patients was 49.34 years (range, 4 to 76 years). During the expansion phase, the patients noted only a little discomfort and pain for the first few days. Without a silicone membrane in the first-generation expander, the rate of successful explantation and good final result was 81.5 percent. In a few cases, rapid swelling of the device led to the introduction of a silicone membrane that encloses the expander and leads to a slower, more gradual, and consistent swelling. After introduction of the silicone envelope, the success rate improved to 91 percent. The expander is now used with a silicone membrane in every case. The osmotic tissue expander has many advantages compared with the conventional expander: there is no need for painful external fillings and the risk of external infections is avoided. The expander is 10 percent of its final volume and only requires a short incision and a small pocket. An operation can easily be performed under local anesthesia, with minimal tissue mobilization in older children and compliant patients.     

A new beginning...

Microbiology is at the beginning of an exciting new era with enormous potential. Whether this potential is maximized is a question of communication.     

Methionine or not methionine at the beginning of a protein

In BioEssays, vol. I. no. 5, p. 227, P. A. Lawrence discussed the selector gene hypothesis and its implications for development. In the following article, D. Gubb presents an alternative view of the genetic control of development.     

Larval supply is a good predictor of recruitment in endemic but not non-endemic fish populations at a high latitude coral reef

Despite extensive research, factors influencing the importance of pre- and post-settlement processes to recruitment variability remain ambiguous. Using a novel perspective, we investigated the potential influence of endemism on the relationship between larval supply and recruitment in reef fish populations at Lord Howe Island, Australia. Larval supply and recruitment were measured for three regional endemic and four widespread non-endemic species using light traps, artificial collectors, and underwater visual censuses. Recruitment was correlated with larval supply in endemics but not in non-endemics, likely due to a combination of low larval supply and post-settlement survival of non-endemics. Surveys also indicated that endemics were far more abundant and occurred in more locations than closely related non-endemics. These preliminary findings suggest that either local adaptation enhances recruitment in endemics through higher larval replenishment rates or reduced post-settlement mortality, populations of widespread species at the periphery of their range are poorly adapted to local environmental conditions and therefore experience lower and more variable settlement and post-settlement survival rates, or both.     

Humanin and Alzheimer's disease: The beginning of a new field

BackgroundHumanin (HN) is an endogenous peptide factor and known as a member of mitochondrial-derived peptides. We first found the gene encoding this novel 24-residue peptide in a brain of an Alzheimer's disease (AD) patient as an antagonizing factor against neuronal cell death induced by AD-associated insults.Scope of reviewThis review presents an overview of HN actions in AD-related conditions among its wide range of action spectrum as well as a brief history of the discovery.Major conclusionsHN exhibits multiple intracellular and extracellular anti-cell death actions and antagonizes various AD-associated pathomechanisms including amyloid plaque accumulation.General significanceThis review concisely reflects accumulated knowledge on HN since the discovery focusing on its functions related to AD pathogenesis and provides a perspective to its potential contribution in AD treatments.     

Further evidence that dioscorea latent virus is a potexvirus

Dioscorea latent virus (DLV) was isolated from Dioscoreafloribunda but was not detected in any of 37 cvs of D. alata, D. bulbifera, D. esculenta or D. rotundata from eight countries. It was readily sap-transmitted to 13 of 34 species from five of 12 families; it induced symptomless systemic infection in Nicotiana benthamiana and N. megalosiphon, but only symptomless local infection in other hosts. DLV was stable in vitro: sap from infected N. megalosiphon was still infective after 10 min at 75–80 ^oC but not 85 ^oC, after dilution to 10^-6 but not 10^-7, and after at least 12 months at 23 ^oC. DLV was not transmitted through seed, by contact or by the aphids Aphis gossypii and Myzus persicae. DLV had filamentous particles most of which measured c. 350–900 nm in purified preparations, with two modal lengths of 445 and 875 nm; the particles sedimented as two components with sedimentation coefficients of 111 S and 131 S and had a buoyant density in caesium chloride of 1–33 g cm^-3. The virus had a single nucleic acid species with a mol. wt of 2–3 ± 04 × 10⁶ and usually produced two protein bands (mol. wts 24 900 and 23 100) in SDS-PAGE, although virus preparations made in the presence of chloroform yielded only the larger polypeptide. DLV was serologically distantly related to commelina X and lily X viruses, but not to 11 other established or possible members of the potexvirus group. These results provide further evidence that DLV is a distinct but definitive potexvirus.     

Conversion of angiotensin-1 to angiotensin-2 by a latent endothelial cell peptidyl dipeptidase that is not angiotensin-converting enzyme

Cultured bovine pulmonary artery endothelial cells contain a second peptidyl dipeptidase, distinct from angiotensin-converting enzyme, present in an inactive form associated with a non-dialyzable inhibitor. Partial purification by glycine affinity chromatography separates enzyme from inhibitor to yield a preparation which hydrolyzes angiotensin-1, bradykinin, substance P, atriopeptin-2, enkephalin and Hip-His-Leu. This enzyme is resistant to inhibition by lisinopril, captopril, thiorphan, phosphoramidon, soybean trypsin inhibitor, PMSF and aminopeptidase and carboxypeptidase inhibitors, but is inhibited by EDTA.     

基因打靶技术:开启遗传学新纪元

基因打靶技术作为最有效的定向修饰小鼠基因的技术手段在揭示基因的生理功能、研究人类疾病的遗传机制以及寻找新的药物靶标的过程中发挥着重要的作用。近年来, 随着条件基因打靶技术的发展使基因失活可以限制在特定时段特定组织或细胞内。文章将主要介绍基因打靶技术的发展简史、近期进展以及在其他模式动物中的应用。