Loss of Primary Cilia Protein IFT20 Dysregulates Lymphatic Vessel Patterning in Development and Inflammation

Microenvironmental signals produced during development or inflammation stimulate lymphatic endothelial cells to undergo lymphangiogenesis, in which they sprout, proliferate, and migrate to expand the vascular network. Many cell types detect changes in extracellular conditions via primary cilia, microtubule-based cellular protrusions that house specialized membrane receptors and signaling complexes. Primary cilia are critical for receipt of extracellular cues from both ligand-receptor pathways and physical forces such as fluid shear stress. Here, we report the presence of primary cilia on immortalized mouse and primary adult human dermal lymphatic endothelial cells in vitro and on both luminal and abluminal domains of mouse corneal, skin, and mesenteric lymphatic vessels in vivo. The purpose of this study was to determine the effects of disrupting primary cilia on lymphatic vessel patterning during development and inflammation. Intraflagellar transport protein 20 (IFT20) is part of the transport machinery required for ciliary assembly and function. To disrupt primary ciliary signaling, we generated global and lymphatic endothelium-specific IFT20 knockout mouse models and used immunofluorescence microscopy to quantify changes in lymphatic vessel patterning at E16.5 and in adult suture-mediated corneal lymphangiogenesis. Loss of IFT20 during development resulted in edema, increased and more variable lymphatic vessel caliber and branching, as well as red blood cell-filled lymphatics. We used a corneal suture model to determine ciliation status of lymphatic vessels during acute, recurrent, and tumor-associated inflammatory reactions and wound healing. Primary cilia were present on corneal lymphatics during all of the mechanistically distinct lymphatic patterning events of the model and assembled on lymphatic endothelial cells residing at the limbus, stalk, and vessel tip. Lymphatic-specific deletion of IFT20 cell-autonomously exacerbated acute corneal lymphangiogenesis resulting in increased lymphatic vessel density and branching. These data are the first functional studies of primary cilia on lymphatic endothelial cells and reveal a new dimension in regulation of lymphatic vascular biology.

Evaluation of reported bone pain in patients (pts) receiving chemotherapy in pegfilgrastim clinical trials

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Background: Bone pain is the most commonly reported treatment-related adverse event (AE) associated with colony-stimulating growth factors. Some authors have suggested that pegfilgrastim-induced bone pain is unpredictable and refractory to analgesics (Kirshner 2007), though that impression may not be uniformly accepted. To better characterize this adverse event we evaluated bone pain across pegfilgrastim clinical trials. Methods: Completed Amgen-sponsored trials that both incorporated pegfilgrastim 6mg administered 24 hours after chemotherapy and utilized MedDRA library coding of AEs were examined. Included were 2 studies comparing pegfilgrastim with placebo (Vogel 2005, Hecht 2007) and 2 studies comparing pegfilgrastim with filgrastim (Sierra 2008, Lopez 2004). The incidence of bone pain was determined by treatment (pegfilgrastim, filgrastim, or placebo), chemotherapy (taxane-containing or not), cycle, severity, age, and body surface area (BSA). Analysis and recoding of studies with preferred AEs coded to nonMedDRA dictionaries is ongoing. Results: 1310 pts (filgrastim=67, pegfilgrastim=665, placebo=578) were analyzed. In studies comparing pegfilgrastim (n=74) and filgrastim (n==7) in pts with AML and NHL, 52% were female, and the mean (SD) age was 50 (15.1) years. Similar proportions (CI) of pts reported bone pain (24.3% [16.1, 35.7] vs 25.4% [15.5, 37.5], respectively), and grade 3/4 bone pain was reported in 3% [0.3, 9] versus 0% [-, -] of pts, respectively. Studies comparing pegfilgrastim (n=591) and placebo (n=578) pts in breast and colorectal cancer are below ( Table ). Conclusions: Bone pain of any grade was commonly reported in all 3 groups (pegfilgrastim, filgrastim, and placebo) and was marginally higher in pts receiving pegfilgrastim compared with placebo. Bone pain was most common in cycle 1. Severe bone pain was infrequently reported. Bone pain was similar in pts receiving pegfilgrastim and filgrastim. Chemotherapy (eg, taxanes) may also contribute to bone pain. [Table: see text]

[Table: see text]

Pharmaceutical Development of a Parenteral Lyophilized Formulation of the Investigational Polymer-Conjugated Platinum Anticancer Agent AP 5280

AP 5280 is a novel polymer-conjugated platinum anticancer agent showing promising in vitro and in vivo activity against solid tumors. The aim of this study was to develop a parenteral pharmaceutical dosage form for phase I clinical trials. AP 5280 drug substance was characterized by using a wide range of analytical techniques and showed excellent solubility in water. However, as aqueous solutions of AP 5280 proved to be labile upon sterilization by moist heat, it was decided to develop a lyophilized dosage form. Initially, glass vials were used as primary packaging, but this led to a high breakage rate, which could be completely prevented by the use of CZ resin vials. Stability studies to date show that the lyophilized product in glass vials is stable for at least 12 months when stored at 2-8 degrees C in the dark and the lyophilized product in CZ resin vials is stable for at least 6 months under these conditions. Photostability testing revealed photolability of AP 5280 drug substance and lyophilized product in both types of primary container, necessitating storage in the dark. The first clinical experiences indicate that the proposed formulation is fully applicable for use in the clinical setting.

Identifying respiratory events and artifacts using oscillatory impedance measurement in aPAP therapy

Constant positive airway pressure (cPAP) is the predominant noninvasive therapy for the obstructive sleep apnea syndrome (OSAS). The average pressure thereby applied can be reduced by online-identification of respiratory events. Oscillatory impedance measurement as an indicator for airway patency can identify central and obstructive apneas and hypopneas. Our goal was to reduce the sensors needed, to auto-calibrate the signals to each individual patient and to rule out patient induced artifacts.

Cloning and expression of homospermidine synthase from Senecio vulgaris: a revision

Homospermidine synthase. which catalyses the first pathway-specific reaction in pyrrolizidine alkaloid biosynthesis, was cloned from root cultures of Senecio vulgaris and expressed in E. coli. The open reading frame encodes a protein of 370 amino acids with a molecular mass of 40,740 Da. The enzyme is strictly dependent on spermidine as aminobutyl donor since it cannot be substituted by putrescine. The homospermidine synthase from S. vulgaris showed 97.9 and 99.3% nucleic acid identity with two HSS sequences from the closely related species Senecio vernalis. This report also revises data from a previous publication (Kaiser, A., 1999. Cloning and expression of a cDNA encoding homospermidine synthase from Senecio vulgaris (Asteraceae) in Escherichia coli. Plant J. 19. 195 201.) that is incorrect.

Simultaneous quantitative determination of the HIV protease inhibitors amprenavir, indinavir, nelfinavir, ritonavir and saquinavir in human plasma by ion-pair high-performance liquid chromatography with ultraviolet detection

A reversed-phase high-performance liquid chromatographic assay for the simultaneous quantitative determination of five HIV protease inhibitors (i.e. amprenavir, indinavir, nelfinavir, ritonavir, and saquinavir) in human plasma is described. Sample pretreatment consisted of solid-phase extraction prior to ion-pair, reversed-phase high-performance liquid chromatography with ultraviolet detection at 210 nm (amprenavir, indinavir and nelfinavir) and 239 nm (saquinavir and ritonavir). For amprenavir, indinavir and saquinavir the method has been validated over the range of 25 ng/ml to 25 microg/ml using a 0.6 ml sample volume. For nelfinavir and ritonavir the method has been validated over the range of 50 ng/ml to 25 microg/ml. The method proved to be accurate, with an average accuracy at four concentrations ranging from 90.6 to 109.2%, and precise, with the within-day and between-day precision ranging from 1.8 to 6.7%, and 0.7 to 7.6%, respectively. The protease inhibitors which can be quantified by using this assay proved to be stable under various conditions. This assay can readily be used in a hospital laboratory for the routine monitoring of plasma concentrations of these protease inhibitors.

Rat atrial muscle responses with caffeine: dose-response, force frequency, and postrest contractions

Caffeine has been reported to have a positive and (or) a negative inotropic effect on cardiac muscle. In this study, the force-frequency and postrest characteristics of rat atrium were studied in the presence of caffeine (1.0-10 mM) to see if the interval between beats affected the response of cardiac muscle to caffeine. When stimulation frequency was 0.5 or 2.0 Hz, there was a positive followed by a negative inotropic response with 1, 5, or 10 mM caffeine. Incomplete relaxation occurred under these circumstances, giving rise to contracture. At low frequency of stimulation (0.1 Hz) caffeine had only a negative inotropic effect, and this effect was greater with 1 mM caffeine than with 5 mM caffeine. In the absence of caffeine, when stimulation at 0.5 or 3 Hz was interrupted, a pause of 2-20 s resulted in potentiation. When caffeine was present (2.0 mM), postrest potentiation was severely attenuated, but the steady-state contraction amplitude within the range 0.5-3.0 Hz was not different. These results are consistent with the hypothesis that caffeine induces a leak of Ca2+ from the sarcoplasmic reticulum, and this Ca2+ is extruded from the cell, possibly by Na+/Ca2+ exchange. Sarcoplasmic reticular uptake of Ca2+ and the translocation to release sites appear not to be affected by caffeine within 1-5 mM concentrations.

Calculated T1 images derived from a partial saturation-inversion recovery pulse sequence with adiabatic fast passage

Calculated T1 images of the head and abdomen have been obtained using an alternating partial saturation-inversion recovery pulse sequence. Timing parameters were adjusted to yield optimum T1 contrast-to-noise ratio for this sequence for the range of T1 studied. Adiabatic fast passage (AFP) was implemented for the nonselective inverting pulse, to reduce the sensitivity of the measurement to RF and static field inhomogeneity. A nonlinear frequency sweep was used to improve the efficiency of the AFP pulse. The effect on the T1 calculation of slice selection during the pi/2 pulses was also determined and corrected for in the image reconstruction algorithm. The T1's determined by this method show a standard deviation of less than 10%, and good agreement with the literature.