CD95 (Fas/APO-1) induces ceramide formation and apoptosis in the absence of a functional acid sphingomyelinase

CD95 is a potent inducer of apoptosis. It activates the caspase cascade, but also induces ceramide (Cer) production, reportedly involving acid sphingomyelinase (aSMase) activity. A role for Cer as a second messenger for apoptosis induction was proposed, based on the finding that synthetic Cer analogues can induce cell death. We have tested whether aSMase is required for 1) apoptosis induction and 2) Cer production by CD95. For this purpose, we have used cultured Niemann-Pick disease (NPD) lymphoid cells with a defined mutation (R600H) in the aSMase protein. Despite their inherited deficiency of aSMase, we found that these cells readily undergo apoptosis upon CD95 stimulation. After retrovirus-mediated gene transfer of the aSMase cDNA, the transduced (i.e. "corrected") NPD cells showed neither increased levels of apoptosis nor altered kinetics of caspase-8 and caspase-3 activation and apoptosis induction as compared with empty vector-transduced cells. The slow sustained elevation of Cer levels in response to CD95, which we have previously documented for Jurkat T cells (Tepper, A. D., Boesen-de Cock, J. G. R., de Vries, E., Borst, J., and van Blitterswijk, W. J. (1997) J. Biol. Chem. 272, 24308-24312), was similarly found in NPD cells. Moreover, the kinetics of Cer formation remained unaffected after aSMase transduction. These results indicate that this Cer does not result from aSMase activity. We conclude that aSMase is not required for and does not facilitate CD95-mediated apoptosis and that it is not responsible for the late Cer response.     

Successful surgical removal of an asymptomatic optic nerve hemangioblastoma in von Hippel-Lindau disease

Image space reconstruction algorithm (ISRA) is a new kind of method for ECT reconstruction. Unlike the ML-EM algorithm which maximizes likelihood function of Possion distribution, ISRA searches for the minimum non-negative mean square solution. In this paper, an improved ISRA (IISRA) algorithm is proposed. A comparison between the algorithms (ISRA and IISRA) demonstrates that the result of IISRA is closer to the test image than that of ISRA. In addition, the IIRSA inherits some properties of ISRA such as convergence.     

Popliteal aneurysm presenting as acute thrombosis and ischemia in a middle-aged man with a history of Kawasaki disease

Kawasaki disease is known to cause a vasculitis of small and medium-sized vessels, with subsequent aneurysm formation. Most of the severe manifestations of the disease occur as a result of coronary aneurysm formation. However, many other arteries have been documented to be involved. A case is presented of a middle-aged man with a history of Kawasaki disease who had an acute ischemic limb from a thrombosed popliteal aneurysm that formed as a result of the disease. This is the first known case report of Kawasaki disease resulting in delayed lower extremity ischemia. Typical findings of patients with Kawasaki disease are presented, along with a case report and review of the literature. A history of Kawasaki disease is an extremely rare but possible cause of peripheral aneurysms, even in middle-aged patients.     

An analog technique for recording leg position learning in the cockroach

A liquid chromatographic method is described for the determination of biogenic amines found in dry sausages: tryptamine, phenylethylamine, putrescine, cadaverine, histamine, serotonin, tyramine, spermidine, and spermine. Amines were extracted with perchloric acid solution and derivatized with dansyl chloride. After derivatization, ammonia was added to remove an interfering peak near cadaverine. Liquid chromatographic separations were performed by using a Spherisorb ODS2 column and an ammonium acetate-acetonitrile gradient elution program. The limits of determination of the individual amines were 1-5 mg/kg. This method is also applicable to detection of amines in other food samples.     

Isolation of marine polycyclic aromatic hydrocarbon (PAH)-degrading Cycloclasticus strains from the Gulf of Mexico and comparison of their PAH degradation ability with that of puget sound Cycloclasticus strains

Phenanthrene- and naphthalene-degrading bacteria were isolated from four offshore and nearshore locations in the Gulf of Mexico by using a modified most-probable-number technique. The concentrations of these bacteria ranged from 10(2) to 10(6) cells per ml of wet surficial sediment in mildly contaminated and noncontaminated sediments. A total of 23 strains of polycyclic aromatic hydrocarbon (PAH)-degrading bacteria were obtained. Based on partial 16S ribosomal DNA sequences and phenotypic characteristics, these 23 strains are members of the genus Cycloclasticus. Three representatives were chosen for a complete phylogenetic analysis, which confirmed the close relationship of these isolates to type strain Cycloclasticus pugetii PS-1, which was isolated from Puget Sound. PAH substrate utilization tests which included high-molecular-weight PAHs revealed that these isolates had similar, broad substrate ranges which included naphthalene, substituted naphthalenes, phenanthrene, biphenyl, anthracene, acenaphthene, and fluorene. Degradation of pyrene and fluoranthene occurred only when the strains were incubated with phenanthrene. Two distinct partial PAH dioxygenase iron sulfur protein (ISP) gene sequences were PCR amplified from Puget Sound and Gulf of Mexico Cycloclasticus strains. Phylogenetic analyses of these sequences revealed that one ISP type is related to the bph type of ISP sequences, while the other ISP type is related to the nah type of ISP sequences. The predicted ISP amino acid sequences for the Gulf of Mexico and Puget Sound strains are identical, which supports the hypothesis that these geographically separated isolates are closely related phylogentically. Cycloclasticus species appear to be numerically important and widespread PAH-degrading bacteria in both Puget Sound and the Gulf of Mexico.     

Histone Sequence Database: new histone fold family members

Searches of the major public protein databases with core and linker chicken and human histone sequences have resulted in the compilation of an annotated set of histone protein sequences. In addition, new database searches with two distinct motif search algorithms have identified several members of the histone fold family, including human DRAP1 and yeast CSE4. Database resources include information on conflicts between similar sequence entries in different source databases, multiple sequence alignments, links to the Entrez integrated information retrieval system, structures for histone and histone fold proteins, and the ability to visualize structural data through Cn3D. The database currently contains >1000 protein sequences, which are searchable by protein type, accession number, organism name, or any other free text appearing in the definition line of the entry. All sequences and alignments in this database are available through the World Wide Web at http://www.nhgri.nih. gov/DIR/GTB/HISTONES or http://www.ncbi.nlm.nih. gov/Baxevani/HISTONES     

Epidermal Growth Factor Stimulates Extracellular-Signal Regulated Kinase Phosphorylation of a Novel Site on Cytoplasmic Dynein Intermediate Chain 2

Extracellular-signal regulated kinase (ERK) signaling is required for a multitude of physiological and patho-physiological processes. However, the identities of the proteins that ERK phosphorylates to elicit these responses are incompletely known. Using an affinity purification methodology of general utility, here we identify cytoplasmic dynein intermediate chain 2 (DYNC1I-2, IC-2) as a novel substrate for ERK following epidermal growth factor receptor stimulation of fibroblasts. IC-2 is a subunit of cytoplasmic dynein, a minus-end directed motor protein necessary for transport of diverse cargos along microtubules. Emerging data support the hypothesis that post-translational modification regulates dynein but the signaling mechanisms used are currently unknown. We find that ERK phosphorylates IC-2 on a novel, highly conserved Serine residue proximal to the binding site for the p150^Glued subunit of the cargo adapter dynactin. Surprisingly, neither constitutive phosphorylation nor a phosphomimetic substitution of this Serine influences binding of p150^Glued to IC-2. These data suggest that ERK phosphorylation of IC-2 regulates dynein function through mechanisms other than its interaction with dynactin.     

Thyroxine and triiodothyronine levels in hyperthyroid patients during treatment with propranolol

In the last few years, there has been an active effort in Italy to involve the population in solving health problems at the community level. This movement had its origin in the industrial setting, where workers succeeded in promoting legislation which gives them control over matters affecting their health. This experience lead to the development of a health education methodology based on the following principles: (a) the assessment of health needs must be based on the subjective experience of the people who have acquired knowledge and interest in health problems; (b) the evaluation of health needs by professionals serves to complement and integrate the assessment of needs as experienced by the community; (c) the self-diagnosis of the community -- in particular of homogenous community groups exposed to similar health risks and experiencing the same needs--and the diagnosis of the professionals must undergo cross-validation and be accepted by both parties; (d) on the basis of this mutual agreement, community health programmes should be planned and carried out jointly by the professionals and the people.     

Low-titer cold-hemagglutinin disease. Mechanism of hemolysis and response to corticosteroids

We studied two patients with a low-titer cold-hemagglutinin disease syndrome to investigate the mechanism of hemolysis and the therapeutic response to corticosteroids. The antierythrocyte antibody was of the IgM class, had a high thermal amplitude and had enough activity of 37 degrees C to account for the hemolysis. The capacity of peripheral blood monocytes to increase the osmotic fragility of C3-coated erythrocytes suggests that macrophage interaction with C3-coated erythrocytes explains the observed in vivo spherocytosis. Both patients responded to high-dose corticosteroids. The data suggest that the steroid effect is probably due to alteration of macrophage complement-receptor function. These studies demonstrate the importance of antibody activity at body temperature in producing hemolysis, particularly in this variant of cold-hemagglutinin disease. The response to steroids suggests the efficacy of corticosteroid therapy in alleviating hemolysis due to macrophage recognition of erythrocytes coated with IgM and C3.     

Cost effective honeycomb and multi-layer insulation debris shields for unmanned spacecraft

Ways to improve the tolerance of unmanned spacecraft to hypervelocity impact are presented. Two new honeycomb and multi-layer insulation (MLI) shields were defined: (1) double honeycomb, and (2) enhanced or toughened MLI (with additional Kevlar 310 and/or Betacloth layers). Following hypervelocity impact testing, a new ballistic limit threshold was defined, based on rear facesheet perforation and witness plate damage characteristics. At 12 km/s, the ballistic limit of single honeycomb was 0.58 mm (aluminium sphere), rising to 0.91 mm for double honeycomb, 1.00 mm for double honeycomb with MLI and 1.17 mm for double honeycomb with toughened MLI. A damage equation, based on the modified Cour-Palais equation with ESA constants, was compared with the data and found to be conservative. The impact angle exponent was increased in order to reduce the equation under-prediction for the oblique incidence data. An equivalent rear wall thickness was defined in order to distinguish between shield types above 7 km/s. The spacecraft survivability analysis showed that the double honeycomb and toughened MLI significantly reduced the number of perforating particles over the baseline single honeycomb design. The mass increase of these shields is approximately 1.2 kg/m² for double honeycomb and 0.8 kg/m² for toughened MLI.