Antimycobacterial matricaria esters and lactones from Astereae species

Six matricaria esters (MEs) and two matricaria lactones (MLs), isolated from members of the tribe Astereae (Asteraceae), were tested against Mycobacterium tuberculosis and M. avium, using a radiorespirometric bioassay. (2Z,8Z)-ME and (2E-8Z)-ME gave minimum inhibitory concentrations (MICs) of 50 micrograms ml-1 against M. tuberculosis and respective MICs of 25 and 50 micrograms ml-1 against M. avium. The (4Z,8Z)-ML, (2Z)-8-dehydro-ME and (2Z,8Z)-10-angeloyloxy-(2Z,8Z)-ME showed respective MICs of 12.5, 25, 25 micrograms ml-1 against M. tuberculosis and MICs of 50, 25, 25 micrograms ml-1 against M. avium, respectively. The MICs of (2Z,8Z)-10-tigloyloxy-ME and (2E,8Z)-10-angeloyloxy-ME and (4E,8Z)-ML ranged from 50 to > 100 micrograms ml-1 against both pathogenic mycobacteria.     

Characterizing semilocal motions in proteins by NMR relaxation studies

The understanding of protein function is incomplete without the study of protein dynamics. NMR spectroscopy is valuable for probing nanosecond and picosecond dynamics via relaxation studies. The use of 15N relaxation to study backbone dynamics has become virtually standard. Here, we propose to measure the relaxation of additional nuclei on each peptide plane allowing for the observation of anisotropic local motions. This allows the nature of local motions to be characterized in proteins. As an example, semilocal rotational motion was detected for part of a helix of the protein Escherichia coli flavodoxin.     

Enhanced B-1 cell development, but impaired IgG antibody responses in mice deficient in secreted IgM

The role of endogenous natural IgM in promoting the adaptive Ab response was investigated in newly constructed mutant mice in which B cells do not secrete IgM but still express surface IgM and IgD and undergo class switching to express other Ig isotypes. While the mutant mice had relatively normal numbers of conventional B (B-2) cells in all tissues examined, unexpectedly, B-1 cells in the peritoneum and spleen were approximately threefold more abundant. The elevated levels of B-1 cells were already detectable at 4 wk of age and were stably maintained throughout life. The levels of serum IgG2a, IgG3, and IgA were also elevated in the mutant mice at an early age. IgG2a response to a T cell-independent Ag was augmented, whereas IgG Ab responses to suboptimal doses of a T cell-dependent Ag were impaired. The latter defect was associated with fewer splenic germinal centers, impaired Ab affinity maturation, and less Ag trapping on follicular dendritic cells. Together, these findings demonstrate a physiologic role of natural IgM in the feedback regulation of B-1 cell development, the regulation of IgG2a production, and the promotion of efficient B-2 cell Ab responses.     

cDNA cloning and chromosomal mapping of a predicted coiled-coil proline-rich protein immunogenic in meningioma patients

There is increasing evidence that tumor expressed genes induce immune responses in cancer patients. To identify meningioma expressed antigens, we established a meningioma expression library which was screened with autologous serum. Out of 20 positive cDNA clones eight share high sequence homologies as determined by sequence analysis. These eight clones can be grouped into three classes which differ in length and which are characterized by specific sequence variations. The longest open reading frame was found to be 2412 bp encoding an immunoreactive antigen termed meningioma expressed antigen 6 (MEA6). Using five sequence specific primer pairs, somatic hybrid panel mapping revealed locations of the three classes on several human chromosomes including chromosomes 2, 3, 6, 7, 9, 13 and 14. The mapping results were confirmed by fluorescence in situ hybridization. RT-PCR showed consistent expression of all classes in several meningiomas and additional tissues using the same set of primer pairs as for chromosomal mapping. The expression data were confirmed by northern blot analysis. For the predicted amino acid sequence BLASTX revealed a homology to a human C219-reactive peptide which was previously isolated by an antibody directed against p-glycoprotein. Sequence properties of the MEA protein include an acidic activation domain, a proline-rich region and two coiled-coil domains indicating protein binding and activation functions.     

Breast infarction after internal mammary artery harvest in a patient with calciphylaxis

The use of the internal mammary artery during coronary artery bypass grafting is commonplace. Complications associated with the harvest of the internal mammary artery have predominantly been wound related. These range from skin dehiscence to complete avascular necrosis of the sternum. This report documents complete ischemic necrosis of a breast in a patient with end-stage renal disease and a history of calciphylaxis, after the harvest of an internal mammary artery.     

CSF-1 stimulation induces the formation of a multiprotein complex including CSF-1 receptor, c-Cbl, PI 3-kinase, Crk-II and Grb2

Recently c-Cbl has been reported to be phosphorylated upon CSF-1 stimulation. The product of the c-cbl proto-oncogene (c-Cbl) is a 120 kDa protein harboring several docking sites for Src homology 2 (SH2) domain containing proteins and proline-rich regions that have been shown to allow its constitutive association with the SH3 domains of Grb2. We demonstrate here that CSF-1 exposure of stable transfectant CHO cells expressing the CSF-1 receptor induced the sustained tyrosine phosphorylation of c-Cbl and its subsequent association with Crk-II and the p85 kDa subunit of the PI 3-kinase, while it constitutively associates with Grb2. We demonstrate by in vitro experiments that these associations require the SH2 domain of Crk-II and both the C- and N-terminal SH2 domains of the p85 subunit of the PI 3-kinase. cCbl is the major PI 3-kinase-containing protein in c-Fms expressing CHO cells upon CSF-1 stimulation. Thus c-Cbl behaves as a core protein, allowing the formation of a quaternary complex including, Crk-II, PI 3-kinase and Grb2. We provide evidence that this multiprotein complex can interact with the tyrosine phosphorylated CSF-1 receptor through the unoccupied SH2 domain of Grb2.     

A possible role for saliva as a diagnostic fluid in patients with chronic pain

Magnetic resonance (MR) imaging of the joints with routine pulse sequences can show the three main categories of osteochondral and chondral injuries: osteochondral fractures, osteochondritis dissecans, and chondral fractures. Detecting acute osteochondral fractures, which frequently accompany ligament tears, may modify patient treatment and ultimately may prove important in long-term prognostication. Staging osteochondritis dissecans lesions is possible with MR imaging and can be used to guide therapy, both surgical and nonsurgical. Specific treatment for chondral fractures is evolving; preoperative diagnosis using MR imaging is advantageous because these lesions often are not initially suspected, they are radiographically occult, and they clinically mimic other internal derangements, for which therapy differs. The MR imaging finding that these traumatic lesions share is the frequent presence of an abnormality in the subchondral bone. Fat-suppressed images are the key to detecting subtle areas of subchondral edema, which in turn may draw attention to a defect in the overlying articular surface.     

GAIA: framework annotation of genomic sequence

As increasing amounts of genomic sequence from many organisms become available, and as DNA sequences become a primary reagent in biologic investigations, the role of annotation as a prospective guide for laboratory experiments will expand rapidly. Here we describe a process of high-throughput, reliable annotation, called framework annotation, which is designed to provide a foundation for initial biologic characterization of previously unexamined sequence. To examine this concept in practice, we have constructed Genome Annotation and Information Analysis (GAIA), a prototype software architecture that implements several elements important for framework annotation. The center of GAIA consists of an annotation database and the associated data management subsystem that forms the software bus along which other components communicate. The schema for this database defines three principal concepts: (1) Entries, consisting of sequence and associated historical data; (2) Features, comprising information of biologic interest; and (3) Experiments, describing the evidence that supports Features. The database permits tracking of annotation results over time, as well as assessment of the reliability of particular results. New framework annotation is produced by CARTA, a set of autonomous sensors that perform automatic analyses and assert results into the annotation database. These results are available via a Web-based query interface that uses graphical Java applets as well as text-based HTML pages to display data at different levels of resolution and permit interactive exploration of annotation. We present results for initial application of framework annotation to a set of test sequences, demonstrating its effectiveness in providing a starting point for biologic investigation, and discuss ways in which the current prototype can be improved. The prototype is available for public use and comment at http://www.cbil.upenn.edu/gaia.     

Critical evaluation of vascular embolization in patients with Rendu-Osler disease

BACKGROUND: As causal therapy of Rendu-Osler-Weber syndrome is not yet possible, there are many different therapeutical approaches. It seemed expedient to investigate the efficacy of super-selective angiography in treating Rendu-Osler-Weber syndrome after this technique proved effective in other therapeutic settings. This method is known to be efficient in controlling tumor bleeding. PATIENTS: Between March 1993 and September 1995, eight patients with an average age of 57 years were treated by super-selective intraarterial embolization. RESULTS: In all cases epistaxis occurred on both sides. Unilateral embolization was performed in ten cases and bilateral embolization in five cases. In two of three patients with nasal packing the embolization permitted removal of the packing. Nevertheless nosebleeds reoccurred on an average of 3.5 days after therapy. Two of eight patients showed long-term improvement after therapy. They suffered fewer nosebleeds than before. Complications included one patient who suffered from partial hemiparesis after embolization, which lasted 1.5 hours and was completely reversible. Another patient died because of pulmonic bleeding caused by manifestation of the disease in this organ. Often patients complained of facial pain or headache which occasionally lasted for a few weeks. CONCLUSIONS: Endovasal embolization obviously is an alternative to artery ligation in emergency cases whereas the long-term success is currently impaired by formation of new anastomoses. Further development of this technique is necessary.