The major activation-inducing collagen receptor glycoprotein VI (GPVI) has been cloned within the last two years. It is a member of the Ig superfamily of proteins and is constitutively associated with the ITAM-bearing Fc receptor gamma-chain (FcR gamma-chain). GPVI signals through a pathway that involves several of the proteins used by Fc, B- and T-lymphocyte receptors and which takes place in glycolipid-enriched membrane domains in the plasma membrane known as GEMs.
View Article and Find Full Text PDFKnowledge of a discrete physiological group capable of excess biological phosphate removal (EBPR) remains unclear. Consequently, microbial community analysis of an enhanced continuous laboratory-scale activated sludge process displaying a strong EBPR mechanism was conducted. Unit design was configured upon the three-stage Phoredox process and characterization of the activated sludge bacterial community was carried out using fluorescent in situ hybridization (FISH) techniques.
View Article and Find Full Text PDFA continuously operated laboratory-scale (32 L) nitrification denitrification biological excess phosphorus removal (NDBEPR) activated sludge system (modeled on the 3-stage Phoredox configuration) was maintained for 140 d. The transition from a non-biological excess phosphorus removal (BEPR) sludge to one exhibiting a strong BEPR mechanism was monitored. Mixed liquor seed inoculum was obtained from a full-scale single aerobic activated sludge installation and subjected to conditions conducive to BEPR, i.
View Article and Find Full Text PDFThis is the final report of a panel convened as part of the Association of American Medical College's (AAMC's) Mission-based Management Program to examine the use of metrics (i.e., measures) in assessing faculty and departmental contributions to the clinical mission.
View Article and Find Full Text PDFFollowing high thoracic spinal cord transection (SCT) in rats, abnormal changes in arterial pressure in response to sensory stimulation (autonomic dysreflexia) are correlated with changes in neural circuitry in the injured spinal cord. Anterograde transport of wheat germ agglutinin conjugated to Texas Red (WGATR) and confocal microscopy were used to characterize the increased arbourization of Adelta and Abeta fibre populations in laminae III-V of the dorsal horn. In cord-injured animals, significantly greater areas of WGATR-labeled fibres were found in the deeper laminae of the dorsal horn than in control rats.
View Article and Find Full Text PDFThyroid hormone is presumed to play a role in initiating and/or orchestrating the postembryonic expression of the genes encoding isoforms of the myosin heavy chains (MHCs) that characterize the muscle fibres in an adult organism. The fact that the postembryonic development of a free-living amphibian tadpole takes place during its thyroid hormone-dependent metamorphosis has made the metamorphosing tadpole an ideal system for elucidating the molecular mechanism(s) by which this hormone affects these postembryonic changes. In this review, we summarize the results from recent studies focused on the postembryonic expression of the MHC genes in the skeletal muscles and hearts of metamorphosing anuran (Rana catesbeiana) tadpoles.
View Article and Find Full Text PDFBiomaterials
November 2000
A novel approach to provide, thermally sensitive neutral solutions based on chitosan/polyol salt combinations is described. These formulations possess a physiological pH and can be held liquid below room temperature for encapsulating living cells and therapeutic proteins; they form monolithic gels at body temperature. When injected in vivo the liquid formulations turn into gel implants in situ.
View Article and Find Full Text PDFThe relationship between detectable human immunodeficiency virus (HIV) genotypic resistance and virologic response was compared in patients receiving nelfinavir as monotherapy (16 weeks) or in combination with lamuvidine and zidovudine (48 weeks). Two patient groups were defined on the basis of the presence or absence of substitutions associated with nelfinavir, a protease (PR) inhibitor, and/or a reverse transcriptase (RT) inhibitor. HIV RNA levels <50 copies/mL were achieved in 17 (85%) of 20 combination-therapy patients without genotypic resistance (PR-RT(-)) versus only 1 (17%) of 6 patients with genotypic resistance (PR-RT(+)).
View Article and Find Full Text PDFThrombotic thrombocytopenic purpura (TTP) is a syndrome characterized by microvascular thrombosis with thrombocytopenia and end-organ injury. Evidence suggests that platelet or endothelial cell injury may be initial pathological events in TTP. A number of factors in patient plasma, including immunoglobulins, have been proposed to mediate cellular injury in TTP.
View Article and Find Full Text PDFIn tadpoles of the North American bullfrog, Rana catesbeiana, spontaneous and thyroid hormone (T3)-induced metamorphosis is characterized by regression of the tail, which is preceded by a decrease in total protein synthesis in tail tissues. We have demonstrated that thyroid hormone treatment of a tadpole does not affect the synthesis of all proteins equally in the tadpole tail muscle. For example, the synthesis of myosin heavy chains (MHCs) is depressed within 1 day and decreases to 45% of control values after 5 days of T3 treatment, whereas the decreased synthesis of soluble muscle proteins is transient and returns to above control levels by day 5.
View Article and Find Full Text PDFThis article describes how the surgery clerkship at MCP Hahnemann School of Medicine was redesigned to provide all students a well-rounded general professional education and to address the specific educational needs of generalists. During the 12-week clerkship, students spend eight weeks on two different general surgery rotations, which include significant experiences in outpatient settings. The evaluation and management of common general surgical problems, as well as the holistic approach to patient care, are emphasized.
View Article and Find Full Text PDFDuring spontaneous or thyroid hormone-induced metamorphosis of the Rana catesbeiana tadpole, postembryonic changes occur in its liver that are permanent and necessary for the transition of this organism from an aquatic, ammonotelic larva to a semiterrestrial, ureotelic adult. These changes include the coordinated expression of genes encoding the urea cycle enzymes carbamyl phosphate synthetase and ornithine transcarbamylase. Although these changes are dependent on thyroid hormone and occur within the resident hepatocytes, the mechanism(s) by which this hormone reprograms gene expression in these cells and initiates the tissue-specific expression of these genes is poorly understood.
View Article and Find Full Text PDFEtiolated maize radicles (inbred Oh43) subjected to a brief heat shock synthesize a family of small heat shock proteins (approximately 18 kD) that is composed of at least 12 members. We previously described the cDNA-derived sequence of three maize shsp mRNAs (cMHSP18-1, cMHSP18-3, and cMHSP18-9). In this report, we demonstrate that the mRNA transcribed in vitro from one of these cDNAs (cMHSP18-9) is responsible for the synthesis of three members of the shsp family, and we suggest that cMHSP18-3 may be responsible for the synthesis of three additional members and cMHSP18-1 for the synthesis of two other members of this family.
View Article and Find Full Text PDFObjective: To determine the false negative fraction (FNF) at a small community hospital and its relation to the discovery of a significant error.
Study Design: All cervical cytologic smears (6,889) initially interpreted over a one-year period (1992) as "normal" or "near normal" were retrospectively rescreened and interpreted by outside institutions, without knowledge of the initial interpretation, to calculate yearly and quarterly FNFs.
Results: The overall FNF for 1992 was 12.
Objective: To determine whether the order of cell collection, endocervical or ectocervical cells first, has an effect on the quality of the Papanicolaou smear.
Methods: One thousand smears were obtained using an Ayre spatula and an endocervical brush. In 500 cases the endocervical brush was used first, and in 500 cases the spatula was used first.
Twenty macaques were used to evaluate the ability of nonpathogenic SIV(mac) or nonpathogenic chimeric SIV-HIV (SHIV) to induce protection in macaques against superinfection with a pathogenic variant of SHIV (SHIV(KU-1)) originally containing the tat, rev, vpu, and env of HIV-1 (strain HXB2) in a genetic background of SIV(mac)239. Specifically, three macaques inoculated with molecularly cloned, macrophage-tropic SIV(mac)LG1 developed an early systemic infection but recovered with only traces of SIV(mac) DNA in visceral lymphoid tissues. These animals were then inoculated parenterally with pathogenic SHIV(KU-1).
View Article and Find Full Text PDFAntimicrob Agents Chemother
July 1997
Two hundred twenty group D streptococci isolated from 1953 to 1954 from patients in the Washington, D.C., area were characterized.
View Article and Find Full Text PDFDuring embryonic development, cartilage formation involves the condensation of mesenchymal stem cells and a series of maturation steps that ultimately results in the mineralized hypertrophic chondrocyte. The embryonic, murine, mesenchymal stem cell line, C3H/10T1/2, is pluripotent; exposure to azacytidine or to bone morphogenetic protein-2 or -4 results in low rates of differentiation to three mesengenic lineages. In contrast to previous studies, we report conditions for 10T1/2 differentiation specifically to the cartilage lineage and at high yields.
View Article and Find Full Text PDFWe have examined both the sequence changes in the LTR, gag, vif, vpr, vpx, tat, rev, vpu, env, and nef genes and the cell tropism of a cell-free stock of chimeric simian-human immunodeficiency virus (SHIV) isolated from the cerebrospinal fluid of a pig-tailed macaque (PNb) that developed AIDS. This virus (SHIVKU-1) is highly pathogenic when inoculated into other macaques. DNA sequence analysis of PCR-amplified products revealed a total of 5 nucleotide changes in the LTR while vif had 2 consensus amino acid changes.
View Article and Find Full Text PDFDuring the spontaneous or thyroid hormone (TH)-induced metamorphosis of Rana catesbeiana, developmental changes occur in its liver that are necessary for the transition of this organism from an ammonotelic larva to a ureotelic adult. These changes include the coordinated expression of genes encoding the urea cycle enzymes carbamyl phosphate synthetase (CPS-I) and arnithine transcarbamylase (OTC). Although the expression of these genes is dependent on TH, the mechanisms(s) by which TH initiates this tissue-specific response is thought to be indirect and to involve early TH-induced upregulation of a gene(s), which, in turn, upregulates the coordinated expression of these urea-cycle enzyme genes.
View Article and Find Full Text PDFCarbamoyl-phosphate synthetase III (CPSase III) of Squalus acanthias (spiny dogfish) is a nuclear-encoded mitochondrial enzyme that catalyzes glutamine-dependent formation of carbamoyl phosphate for urea synthesis. In this paper we report the results of cloning a 10-kb segment of genomic DNA which includes the region flanking the 5' end of the spiny dogfish CPSase III gene. A total of 1,295 base pairs of sequence straddling the start codon was obtained.
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