Coreceptor Switch of [MLV(SIVagm)] pseudotype vectors by V3-loop exchange

Retroviral vectors derived from murine leukemia virus (MLV) have been pseudotyped with a variant of the envelope glycoprotein (Env) of nonpathogenic simian immunodeficiency virus from African green monkeys (SIVagm) to result in [MLV(SIVagm-wt)] vector particles. The variant env gene encodes a full-length surface envelope glycoprotein (SU) and a C-terminally truncated transmembrane protein (TM). To change the coreceptor usage of this vector from CCR5 to CXCR4, which is predominant on human CD4-positive lymphocytes, the putative V3-loop of SIVagm SU was replaced by that of the T cell tropic HIV-1 variant BH10. The resulting [MLV(SIVagm-X4)] vectors were shown to specifically transduce CD4/CXCR4-positive cell lines, demonstrating the equivalent function in cell entry and choice of coreceptor usage of the V3-loops of SIVagm and HIV-1. These modified vectors were able to transduce primary human lymphocytes and were resistant to neutralization by sera from HIV-1-infected individuals. The [MLV(SIVagm-X4)] pseudotype vector generated is thus a promising candidate vector, e.g., for in vivo gene therapy of HIV-1 infection.     

Characterization of West AfricanTrypanosoma (Trypanozoon) brucei isolates from man and animals using isoenzyme analysis and DNA hybridization

A total of 18 West AfricanTrypanosoma (Trypanozoon) brucei stocks isolated from man and animals were characterized using isoenzyme analysis with isoelectric focusing (IEF) and DNA hybridization. They were compared with fourT. (T.) brucei isolates from East and West Africa that had previously been analysed and well defined. All experiments were carried out with cell lysates of procyclic trypanosomes produced in vitro. The different stocks could be separated into two distinct groups according to their isoenzyme and DNA patterns. The homogeneous group ofT. b. gambiense was characterized by zymodeme A and highly specific DNA-banding patterns (type G) always associated with stable human serum resistance. The non-gambiense group (consisting ofT.b. rhodesiense andT. b. brucei) was determined by a great variation in these markers. Our results clearly indicate the existence, ofT. b. rhodesiense-like parasites in West African patients. Due to their lack of human serum resistance, the four characterized animal isolates can be referred to asT. b. brucei.     

Hypo- and hypertetraploidy in a case of erythroleukemia analyzed by fluorochrome banding techniques

Chromosome studies of a case of erythroleukemia in a 57-year-old female patient were made from bone marrow aspirates using the fluorescent primary stain/counterstain methodology. The chromosome number ranged from 42 to 110. There was a high proportion of hypotetraploid cells and a few hypertetraploid and hypooctaploid ones. Structurally normal chromosomes varied in number from cell to cell, ranging from one to seven in the polyploid cells. A number of marker chromosomes were observed, some of which occurred repeatedly in two copies per hypotetraploid cell. The chromosomes involved in aberrations were tentatively identified as #3, #5, #7, #12, #13, #15, #16, #18, #19, and #21. In the abnormal chromosome #16, which was missing a normal short arm, a new kind of heterochromatin was demonstrated by sequential staining with DA-DAPI and DAPI-AMD, suggesting de novo amplification of an A-T-rich satellite DNA sequence.     

THE EFFECT OF PROSTAGLANDIN E1 ON PULMONARYBLOOD FLOW AFTER RETROGRADE FLUSH ANDCOLD STORAGE OF LUNGS

ReSllm6 Objectif Nos studes Precedentes out montrd une panne fonCtion de la greffe pulmonaire traitde Prdalablementper perfusion forcde retrograde et un stockage d froid inns ~. L' etude Prdsente a pour but de determiner l' effet de ~ surlefiot mngUin du poumon trait4 Prdalablement per perfusion retrograde forcde et un stockage d froid. met~. 12poumons donneurs canins out ate trait4s per perfusion r4tFograde de solution UW. Chez 6 animaux du grouch A, 250ng furent injectes dans l' artrdre…     

The N-terminal domain of gamma-aminobutyric Acid(B) receptors is sufficient to specify agonist and antagonist binding.

The recently identified gamma-aminobutyric acid type B receptors (GABA(B)Rs) share low sequence similarity with the metabotropic glutamate (mGlu) receptors. Like the mGlu receptors, the N-terminal extracellular domain (NTED) of GABA(B)Rs is proposed to be related to bacterial periplasmic binding proteins (PBPs). However, in contrast to the mGlu receptors, the GABA(B)Rs lack a cysteine-rich region that links the PBP-like domain to the first transmembrane domain. This cysteine-rich region is necessary for the PBP-like domain of mGlu receptors to bind glutamate. To delimit the ligand-binding domain of GABA(B)Rs, we constructed a series of chimeric GABA(B)R1/mGluR1 and truncated GABA(B)R1 receptor mutants. We provide evidence that despite the lack of a cysteine-rich region, the NTED of GABA(B)Rs contains all of the structural information that is necessary and sufficient for ligand binding. Moreover, a soluble protein corresponding to the NTED of GABA(B)Rs reproduces the binding pharmacology of wild-type receptors. This demonstrates that the ligand-binding domain of the GABA(B)Rs can correctly fold when dissociated from the transmembrane domains.     

An assessment of pharmaceutical inspection reports from nursing and residential homes for the elderly in Northern Ireland

Objectives To highlight issues currently being inspected in nursing, residential and dual‐registered homes (care homes) for the elderly in Northern Ireland as part of a pharmaceutical inspection. Methods A cross‐sectional survey and analysis of reports from pharmaceutical inspections in Northern Ireland care homes between January 1999 and December 2000 was undertaken, using reports provided by the four Registration and Inspection Units (R & I Units 1–4) within the region. Reports were reviewed and all recommendations made by inspectors were classified into 11 main categories. Binary logistic regression was used to examine possible relationships between the type of home (nursing, residential or dual‐registered) or the R & I unit and the recommendations made by the inspectors, with corresponding odds ratios and 95% confidence intervals. Key findings Reports from 415 homes (one report per home) formed the final sample for analysis. Each R & I unit used different documentation to conduct a pharmaceutical inspection. Homes received the majority of recommendations from inspectors in the categories ‘Records’ (66.7% of all homes), ‘Policies and protocols’ (39.3%) and ‘Medication’ (31.8%). More recommendations in a number of categories emanated from R & I unit 4 compared with R & I unit 1 (referent). Dual‐registered homes (those registered as a nursing and residential facility) were more likely to receive a recommendation in the categories ‘Storage of medicine’, ‘Order and receipt of medication’ and ‘Equipment’ than nursing or residential homes. Conclusion Inspections of care homes should be standardised in terms of documentation used and facilities should be given guidance on issues that are likely to result in recommendations from inspectors. In the longer‐term, pharmaceutical inspections should move from a focus on structure/process measures to those that emphasise quality in prescribing.     

Centrosome aberrations as a possible mechanism for chromosomal instability in non-Hodgkin's lymphoma.

Recently, centrosome aberrations have been described as a possible cause of aneuploidy in many solid tumors. To investigate whether centrosome aberrations occur in non-Hodgkin's lymphoma (NHL) and correlate with histologic subtype, karyotype, and other biological disease features, we examined 24 follicular lymphomas (FL), 18 diffuse large-B-cell lymphomas (DLCL), 33 mantle cell lymphomas (MCL), and 17 extranodal marginal zone B-cell lymphomas (MZBCL), using antibodies to centrosomal proteins. All 92 NHL displayed numerical and structural centrosome aberrations as compared to nonmalignant lymphoid tissue. Centrosome abnormalities were detectable in 32.3% of the cells in NHL, but in only 5.5% of lymphoid cells from 30 control individuals (P<0.0001). Indolent FL and MZBCL contained only 25.8 and 28.8% cells with abnormal centrosomes. In contrast, aggressive DLCL and MCL harbored centrosome aberrations in 41.8 and 35.0% of the cells, respectively (P<0.0001). Centrosomal aberrations correlated to lymphoma grade, mitotic, and proliferation indices, but not to the p53 labeling index. Importantly, diploid MCL contained 31.2% cells with abnormal centrosomes, while tetraploid samples harbored centrosome aberrations in 55.6% of the cells (P<0.0001). These results indicate that centrosome defects are common in NHL and suggest that they may contribute to the acquisition of chromosomal instability typically seen in NHL.     

Expression of Daxx sensitizes Jurkat T-cells to the apoptosis-inducing effect of chemotherapeutic agents.

BACKGROUND: The role of Daxx, in particular its ability to promote or hinder apoptosis, still remains controversial. In order to elucidate the functional relevance of Daxx in the extrinsic signaling of malignant lymphocytes Jurkat T-cells were stably transfected with a Daxx-expressing vector or with the respective Daxx-negative control vector. RESULTS: Assessing first the impact of Daxx expression on the rate of proliferation we demonstrate that overexpression of Daxx alone is not sufficient to alter proliferation in neoplastic lymphocytes. Nevertheless, expression of Daxx down-regulates anti-apoptotic Bcl-2 and up-regulates pro-apoptotic BID. In addition, Daxx-overexpressing Jurkat cells exhibit a decreased expression of the pro-caspase-8, -10, -9 and -3 and a concomitant increase of the inhibitors of apoptosis proteins survivin, XIAP, cIAP-1 and -2. We further demonstrate, that upon incubation with various chemotherapeutic agents these Daxx-induced molecular alterations sensitize Jurkat T-cells to the apoptosis-inducing effects of specific chemotherapeutic agents. CONCLUSIONS: We here outline the molecular changes elicited by Daxx on major components of the apoptotic cascade of malignant lymphocytes and demonstrate the capacity of Daxx to sensitize these cells to the apoptosis-inducing effect of various chemotherapeutic agents.