"No Dr. Blue/do not resuscitate"

A friend of Sharon Siebert's describes her efforts leading to the issuing of a restraining order (Hoyt v. St. Mary's Rehabilitation Center) to prevent the nursing home from implementing a "do not resuscitate" order written by the physician of the brain-damaged Siebert.     

Detection of "<Emphasis Type="Italic">Rickettsia</Emphasis> sp. strain Uilenbergi" and "<Emphasis Type="Italic">Rickettsia</Emphasis> sp. strain Davousti" in <Emphasis Type="Italic">Amblyomma tholloni</Emphasis> ticks from elephants in Africa

Background  

To date, 6 tick-borne rickettsiae pathogenic for humans are known to occur in Africa and 4 of them were first identified in ticks before being recognized as human pathogens.     

Species identification of <Emphasis Type="Italic">Campylobacter jejuni</Emphasis> ssp. <Emphasis Type="Italic">jejuni</Emphasis> and <Emphasis Type="Italic">C. coli</Emphasis> by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry and PCR

The Campylobacter species strains (n = 42; isolated from clinical samples and deposited in Czech National Collection of Type Cultures, Prague) originally phenotypically (and biochemically) identified as Campylobacter jejuni were re-classified using molecular biological and mass spectrometric methods. Whole-cell MALDI-TOF MS (matrix-assisted laser desorption/ionization time-of-flight mass spectrometry) separated the isolates into two genetically related strains — C. jejuni (n = 26) and C. coli (n = 16) and, moreover, distinguished the intimate details in the group of tested strains. It also made it possible to create the MALDI-TOF MS dendrogram; similarly, the spectral characteristics were used for the 3D cluster analysis. Polymerase chain reaction (PCR) confirmed the results obtained by mass spectrometry. Both methods (PCR and MALDI-TOF MS) gave the same results which supports their suitability in the rapid and accurate Campylobacter-species determination. Part of this work was presented at the 24th Congress of Czechoslovak Society for Microbiology, Liberec (Czech Republic) 2007.     

Purification and some properties of -poly-l-lysine-degrading enzyme from Kitasatospora sp. CCTCC M205012

An -poly-l-lysine-degrading enzyme (PLD) from Kitasatospora sp. CCTCC M205012 has been purified to homogeneity by three steps of anion-exchange chromatography including DEAE-Sepharose, Source 15Q and Mono Q, with a 500-fold increase in specific activity and 40.9% yield. The PLD has a molecular mass of approximately 87.0 kDa and consists of two identical subunits with a molecular mass of 43.6 kDa. Electrophoretic shows that the PLD isoelectric point was about 7.2. The optimum temperature and pH for the PLD was 30 °C and 7.0, respectively. The PLD was deactivated by EDTA, which was indicated that the enzyme was a metallo enzyme. The activity of PLD was stimulated by Co²⁺ and inhibited by Ca²⁺ remarkably. The apparent K_m with l-lysyl-p-nitroanilide as substrate was 0.216 mM and the V_max was 0.112 mmol/min mg. The PLD was an exo-type enzyme and monomers of l-lysine were detected during the enzymatic degradation of -PL.     

Protein kinase C-α negatively regulates EGF-induced PLC- activity through direct phosphorylation

Phospholipase C- is a PLC isozyme that contains a CDC25 homology domain and a pair of RA domains in addition to a conserved PLC catalytic domain. PLC- is activated by both growth factors and GPCR ligands in a distinct manner. Growth factors such as EGF stimulate PLC- in an RA2 domain-dependent manner through Ras and Rap. On the other hand, several GPCR ligands that are linked with Ga₁₂ or Ga₁₃ can activate PLC- by associating with GTP-RhoA. GTP-RhoA binds with the region in the PLC- Y domain. Gs-linked ligands such as PGE1 and adrenaline stimulate PLC- by cAMP-dependent activation of Epac and Rap2B. PLC- is important for cardiac development and function. In addition, several lines of evidence indicate that PLC- promotes cell growth in an activity-dependent or -independent manner. In particular, PLC--dependent suppression of EGF receptor downregulation contributes to its growth promoting activity. Proper regulation of PLC- activity is essential for preventing tumor formation. Our previous report indicated that EGF-dependent ubiquitination of PLC- is required for the control of PLC--dependent cell growth. Recently, we found that PLC- is phosphorylated by growth factor stimulation, and this is another mechanism of the negative regulation. PLC- is phosphorylated by PKC-α upon stimulation with growth factors such as EGF and PDGF. The EGF-induced phosphorylation of PLC- was abolished by PKC inhibitors and by the expression of the dominant negative mutant of PKC-α. Furthermore, PKC-α was found to phosphorylate PLC- directly in vitro, suggesting that PLC- is a substrate of PKC-α in cells. In addition, PLC- was co-immunoprecipitated with PKC-α in an EGF-dependent manner. Immunocytochemical studies showed that PLC- co-localized with PKC-α in the plasma membrane after EGF stimulation. In addition, inhibition of PKC activity enhanced PLC--mediated PIP₂ hydrolysis, suggesting that PKC-α negatively regulates PLC- activity. Taken together, these results suggest for the first time that PLC- is regulated by PKC-α-dependent phosphorylation.