Failure of testicular development associated with a rearrangement of 9p24.1 proximal to the SNF2 gene

In 46,XY individuals, testes are determined by the activity of the SRY gene (sex-determining region Y), located on the short arm of the Ychromosome. The other genetic components of the cascade that leads to testis formation are unknown and may be located on the Xchromosome or on the autosomes. Evidence for the existence of several loci associated with failure of male sexual development is indicated by reports of 46,XY gonadal dysgenesis associated with structural abnormalities of the Xchromosome or of autosomes (chromosomes9, 10, 11 and 17). In this report, we describe the investigation of a child presenting with multiple congenital abnormalities, mental retardation and partial testicular failure. The patient had a homogeneous de novo 46,XY,inv dup(9)(pter→p24.1::p21.1 →p23.3::p24.1→qter) chromosome complement. No deletion was found by either cytogenetic or molecular analysis. The SRY gene and DSS region showed no abnormalities. Southern blotting dosage analysis with 9p probes and fluorescent in situ hybridisation data indicated that the distal breakpoint of the duplicated fragment was located at 9p24.1, proximal to the SNF2 gene. We therefore suggest that a gene involved in normal testicular development and/or maintenance is present at this position on chromosome 9. Received: 20 January 1997 / Accepted: 5 November 1997     

Detection of Mycobacterium leprae DNA in clinical and environmental samples using serological analysis and PCR

Molecular Biology Reports - Leprosy is a chronic infectious disease caused by Mycobacterium leprae and persists as a serious public health problem in Brazil. This microorganism is inculturable,...     

Targeting TRAIL

Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL), also known as Apo2L, has been investigated in the past decade for its promising anticancer activity due to its ability to selectively induce apoptosis in tumoral cells by binding to TRAIL receptors (TRAIL-R). Macromolecules such as agonistic monoclonal antibodies and recombinant TRAIL have not proven efficacious in clinical studies, therefore several small molecules acting as TRAIL-R agonists are emerging in the scientific literature. In this work we focus on systemizing these drug molecules described in the past years, in order to better understand and predict the requirements for a novel anti-tumoral therapy based on the TRAIL-R-induced apoptotic mechanism.     

Considerations about the chirality of the saturated six-membered rings with two or more heteroatoms

The chirality of the title heterocycles is discussed considering their genesis by desymmetrization of the corresponding adamantanes. Some rules for the specification of the absolute configurations of the enantiomers (R or S) for this type of compounds are proposed. © 1996 Wiley-Liss, Inc.     

Apoptosis in human embryo development: 2. Cerebellum

We analysed the spatial and temporal distribution of apoptosis in human cerebellum development, during embryonic and fetal periods. Cerebella excised from two human embryos (8 weeks old) and eight fetuses (12-22 weeks old), were paraffin embedded and serially sectioned. Apoptotic cells were identified by propidium iodide staining, and TUNEL. In addition, immunohistochemistry for suicide receptor Fas(APO-1/CD95) was performed. We determined the distribution and percentage of apoptotic cells as well as Fas(APO-1/CD95)-positive cells in different regions and stages of development. Apoptotic cells were seen in both proliferative zones and postmitotic regions along the migratory pathways as well as in the developing cerebellar cortex in all examined stages. The Fas(APO-1/CD95) immunoreactivity was present in all examined stages in a small population of apoptotic cells: either neuroblasts or differentiated cells in postmitotic zones. These findings suggest that apoptosis drives the selection of the cells which are committed to differentiate during the early stages of cerebellar development. The differences between apoptotic cells distribution and Fas receptor expression suggest that cell selection is driven by different apoptotic pathways.     

Endogenous type I interferons as a defense against tumors

We have reviewed the experimental results which indicate that endogenous type I interferon (IFN) present either constitutively or possibly induced by the tumor plays an important role in limiting the development of transplantable tumors in mice. Thus, treatment with potent polyclonal neutralizing antibodies to IFN alpha/beta markedly enhanced the subcutaneous growth, invasiveness and metastases of xenogeneic tumor cells (uninfected or infected with RNA or DNA viruses) in athymic nude mice; enhanced the intraperitoneal transplantability of six different syngeneic murine tumors in three strains of immunocompetent mice; and completely abrogated the resistance of allogeneic C57Bl/6 (H-2(b)) or C3H (H-2(k)) mice to the multiplication of Friend erythroleukemia cells (H-2(d)) in the liver and spleen resulting in the death of most mice. The mechanisms by which mice respond to the injection of relatively few tumor cells appear to be multiple, to depend on the site of tumor growth, to occur early and prior to an immunologic response. Endogenous type I IFN appears to constitute an essential component of these defense mechanisms enabling the host to restrict tumor growth.     

应用离子注入技术对家蚕形态学及遗传学进行的初步研究(英文)

离子注入技术是将某种元素的原子进行电离,并使其在电场中加速,在获得较高的速度后射入固体材料表面。在离子注入过程中,被电离的离子在电场作用下加速运动,离子靠着本身获得的动能进入基体表面,在表层中运动的离子与基体原子作用损失能量后在一定的位置停留下来。该技术自６０年代问世以来,主要用于材料改性等方面。８０年代中期,我国学者开始将其用于农作物育种方面的研究,大大拓宽了离子注入技术的应用领域。所用实验材料的基因及表现型见Ｔａｂ３,我们将氢离子（Ｅ＝３５ＭｅＶ）注入处于胚胎发育后期的家蚕卵内（Ｔａｂ１）,观察其对家蚕形态及遗传方面的影响,结果表明：（１）在家蚕胚胎发育的已４期注入氢离子,其半致死剂量ＬＤ５０为１ｘ１０１０～１ｘ１０１１ｃｍ２这一区间之内;当剂量达到１ｘ１０１２ｃｍ２时,已全部致死（Ｆｉｇ．１＆Ｔａｂ．２）;（２）注入氢离子能够使家蚕在第１腹节上产生褐斑（Ｆｉｇ．２）的频率增高。并首次观察到因注入氢离子而导致家蚕出现非成对的褐斑（Ｆｉｇ．３＆Ｔａｂ．４）。（３）在氢离子注入剂量为１ｘ１０１０ｃｍ２时,能够诱变产生大量的嵌合体家蚕,并且诱变频率高达３８．５％（Ｆｉｇ．４＆Ｔａｂ．５）,这样高的     

Lithium Polyacrylate (LiPAA) as an Advanced Binder and a Passivating Agent for High‐Voltage Li‐Ion Batteries

Intensive studies of an advanced energy material are reported and lithium polyacrylate (LiPAA) is proven to be a surprisingly unique, multifunctional binder for high‐voltage Li‐ion batteries. The absence of effective passivation at the interface of high‐voltage cathodes in Li‐ion batteries may negatively affect their electrochemical performance, due to detrimental phenomena such as electrolyte solution oxidation and dissolution of transition metal cations. A strategy is introduced to build a stable cathode–electrolyte solution interphase for LiNi_0.5Mn_1.5O₄ (LNMO) spinel high‐voltage cathodes during the electrode fabrication process by simply using LiPAA as the cathode binder. LiPAA is a superb binder due to unique adhesion, cohesion, and wetting properties. It forms a uniform thin passivating film on LNMO and conducting carbon particles in composite cathodes and also compensates Li‐ion loss in full Li‐ion batteries by acting as an extra Li source. It is shown that these positive roles of LiPAA lead to a significant improvement in the electrochemical performance (e.g., cycle life, cell impedance, and rate capability) of LNMO/graphite battery prototypes, compared with that obtained using traditional polyvinylidene fluoride (PVdF) binder for LNMO cathodes. In addition, replacing PVdF with LiPAA binder for LNMO cathodes offers better adhesion, lower cost, and clear environmental advantages.