Boston University

About: Boston University is a education organization based out in Boston, Massachusetts, United States. It is known for research contribution in the topics: Population & Poison control. The organization has 48688 authors who have published 119622 publications receiving 6276020 citations. The organization is also known as: BU & Boston U.

A new bacteriophage P1-derived vector for the propagation of large human DNA fragments

Abstract: We have designed a P1 vector (pCYPAC−1) for the introduction of recombinant DNA into E. coli using electroporation procedures. The new cloning system, P1−derived arteficial chromosomes (PACs), was used to establish an initial 15,000 clone library with an average insert size of 130−150 kilobase pairs (kb). No chimaerism has been observed in 34 clones, by fluorescence in situ hybridization. Similarly, no insert instability has been observed after extended culturing, for 20 clones. We conclude that the PAC cloning system will be useful in the mapping and detailed analysis of complex genomes.

Lysyl oxidase: Properties, specificity, and biological roles inside and outside of the cell

Abstract: Lysyl oxidase (LO) plays a critical role in the formation and repair of the extracellular matrix (ECM) by oxidizing lysine residues in elastin and collagen, thereby initiating the formation of covalent crosslinkages which stabilize these fibrous proteins. Its catalytic activity depends upon both its copper cofactor and a unique carbonyl cofactor and has been shown to extend to a variety of basic globular proteins, including histone H1. Although the three-dimensional structure of LO has yet to be determined, the present treatise offers hypotheses based upon its primary sequence, which may underlie the prominent electrostatic component of its unusual substrate specificity as well as the catalysis-suppressing function of the propeptide domain of prolysyl oxidase. Recent studies have demonstrated that LO appears to function within the cell in a manner, which strongly modifies cellular activity. Newly discovered LO-like proteins also likely play unique roles in biology. © 2002 Wiley-Liss, Inc.

Combination antiretroviral strategies for the treatment of pregnant HIV-1-infected women and prevention of perinatal HIV-1 transmission.

Abstract: Context The Women and Infants Transmission Study is a prospective natural history study that has been enrolling HIV-1-infected pregnant women and their infants since 1989. Objective To evaluate the impact of different antiretroviral regimens on perinatal HIV-1 transmission at the population level. Design Prospective cohort study. Plasma HIV-1 RNA levels were serially measured in 1542 HIV-1-infected women with singleton live births between January 1990 and June 2000. Main outcome measure HIV-1 status of the infant. Results HIV-1 transmission was 20.0% (95% confidence interval [CI], 16.1%-23.9%) for 396 women who not receiving prenatal antiretroviral therapy; 10.4% (95% CI, 8.2%-12.6%) for 710 receiving zidovudine monotherapy; 3.8% (95% CI, 1.1%-6.5%) for 186 receiving dual antiretroviral therapy with no or one highly active drug (Multi-ART); and 1.2% (95% CI, 0-2.5%) for 250 receiving highly active antiretroviral therapy (HAART). Transmission also varied by maternal delivery HIV RNA level: 1.0% for 30,000 copies/mL (p =.0001 for trend). The odds of transmission increased 2.4-fold (95% CI, 1.7-3.5) for every log10 increase in delivery viral load. In multivariate analyses adjusting for maternal viral load, duration of therapy, and other factors, the odds ratio for transmission for women receiving Multi-ART and HAART compared with those receiving ZDV monotherapy was 0.30 (95% CI, 0.09-1.02) and 0.27 (95% CI, 0.08-0.94), respectively. Conclusion Levels of HIV-1 RNA at delivery and prenatal antiretroviral therapy were independently associated with transmission. The protective effect of therapy increased with the complexity and duration of the regimen. HAART was associated with the lowest rates of transmission.

Architecture and intrinsic connections of the prefrontal cortex in the rhesus monkey.

Abstract: An investigation of the architectonic organization and intrinsic connections of the prefrontal cortex was conducted in rhesus monkeys. Cytoarchitectonic analysis indicates that in the prefrontal cortex there are two trends of gradual change in laminar characteristics that can be traced from limbic periallocortex towards isocortical areas. The stepwise change in laminar features is characterized by the emergence and gradual increase in the width of granular layer IV, by an increase in the size of pyramidal cells in layers III and V, and by a higher cell-packing density in the supragranular layers. Myeloarchitectonic analysis reveals that the limbic areas are poorly myelinated, adjacent areas have a diffuse myelin content confined to the deep layers, and in isocortices the myelinated fibers are distributed in organized horizontal bands (of Bail-larger) and a vertical plexus. Using the above architectonic criteria, we observed that one of the architectonic trends takes a radial basoventral course from the periallocortex in the caudal orbitofrontal region to the adjacent proisocortex and then to area 13. The next stage of architectonic regions includes orbital areas 12, 11, and 14, which is followed by area 10, lateral area 12, and the rostral part of ventral area 46. The last group includes the caudal part of ventral area 46 and ventral area 8. The other trend takes a mediodorsal course from the periallocortex around the rostral portion of the corpus callosum to the adjacent proisocortical areas 24, 25, and 32 and then to the medially situated isocortical areas 9, 10, and 14. The next stage includes lateral areas 10 and 9 and the rostral part of dorsal area 46. The last group includes the caudal part of dorsal area 46 and dorsal area 8. The interconnections of subdivisions of the basoventral and mediodorsal cortices were studied with the aid of anterograde and retrograde tracers. Within each trend a given area projects in two directions: to adjoining regions belonging to succeeding architectonic stages on the one hand, and to nearby regions from the preceding architectonic stage on the other. In each direction there is more than one region involved in this projection system, paralleling the radial nature of architectonic change. Periallo- and proisocortices have widespread intrinsic connections, whereas isocortices situated at a distance from limbic areas, such as area 8, have restricted connections. Most interconnections are limited to areas within the same architectonic trend. However, there are links between cortices from the two trends, and these seem to occur between areas that are at a similar stage of architectonic differentiation.(ABSTRACT TRUNCATED AT 400 WORDS)