We report the detection of pulsed gamma-rays from the young, spin-powered radio pulsar PSR J2021+3651 using data acquired with the Large Area Telescope (LAT) on the Fermi Gamma-ray Space Telescope ...(formerly GLAST). The light curve consists of two narrow peaks of similar amplitude separated by 0.468 +/- 0.002 in phase. The first peak lags the maximum of the 2 GHz radio pulse by 0.162 +/- 0.004 +/- 0.01 in phase. The integral gamma-ray photon flux above 100 MeV is (56 +/- 3 +/- 11) x 10(-8) cm(-2) s(-1). The photon spectrum is well described by an exponentially cut-off power law of the form dF/dE = kE(-Gamma)e((-E/Ec)), where the energy E is expressed in GeV. The photon index is Gamma = 1.5 +/- 0.1 +/- 0.1 and the exponential cut-off is E-c = 2.4 +/- 0.3 +/- 0.5 GeV. The first uncertainty is statistical and the second is systematic. The integral photon flux of the bridge is approximately 10% of the pulsed emission, and the upper limit on off-pulse gamma-ray emission from a putative pulsar wind nebula is < 10% of the pulsed emission at the 95% confidence level. Radio polarization measurements yield a rotation measure of RM = 524 +/- 4 rad m(-2) but a poorly constrained magnetic geometry. Re-analysis of Chandra X-ray Observatory data enhanced the significance of the weak X-ray pulsations, and the first peak is roughly phase aligned with the first gamma-ray peak. We discuss the emission region and beaming geometry based on the shape and spectrum of the gamma-ray light curve combined with radio and X-ray measurements, and the implications for the pulsar distance. Gamma-ray emission from the polar cap region seems unlikely for this pulsar.
Macrophages are accessory cells that are vulnerable to infection by HIV-1. HTLV-III
B, a lymphotropic strain of HIV, infects macrophages poorly resulting in either no or low levels of virus ...expression compared to high levels of productive infection after exposure of macrophages to the monocytotropic HIV strain Ada-M. Whether this results in an impaired ability of HTLV-III
B-exposed macrophages to initiate protective cytotoxic T lymphocyte (CTL) immune responses against these strains is not well defined. We investigated the ability of monocyte-derived macrophages (MDM) exposed to lymphotropic and monocytotropic HIV strains to initiate primary CTL responses in vitro. MDM exposed to HTLV-III
B induced a specific primary CTL response that was comparable to MDM exposed to the monocytotropic strain Ada-M despite marked differences in productive HIV infection in MDM between the two strains. CTL generated in this model were MHC-restricted, strain-specific, and CD8
+. These data demonstrate that high levels of productive HIV infection in accessory cells are not a prerequisite for the generation of a primary CTL response, suggesting a novel immunologic interaction between MDM and lymphotropic HIV strains.
Radiofrequency ablation of cancer Friedman, Marc; Mikityansky, Igor; Kam, Anthony ...
Cardiovascular and interventional radiology,
09/2004, Letnik:
27, Številka:
5
Journal Article
Recenzirano
Odprti dostop
Radiofrequency ablation (RFA) has been used for over 18 years for treatment of nerve-related chronic pain and cardiac arrhythmias. In the last 10 years, technical developments have increased ablation ...volumes in a controllable, versatile, and relatively inexpensive manner. The host of clinical applications for RFA have similarly expanded. Current RFA equipment, techniques, applications, results, complications, and research avenues for local tumor ablation are summarized.
The objectives of the current study were to evaluate the efficacy and field safety of GnRH HCl administered at 3 doses in fixed-time artificial insemination (FTAI) programs (Ovsynch) in dairy cows. A ...common protocol was conducted at 6 commercial dairies. Between 188 and 195 cows were enrolled at each site (total enrolled = 1,142). Cows had body condition scores ≥2 and ≤4, were between 32 to 140d in milk, and were clinically healthy. Within pen and enrollment day (enrollment cohort), cows were assigned randomly in blocks of 4 to each of 4 treatments: (1) 25mg of PGF2α on d 7 with FTAI 72±2h later (control); (2) 100μg of GnRH on d 0, d 7 a dose of 25mg of PGF2α, and the second administration of 100μg of GnRH (T100) administered either at 48±2h (d 9) after PGF2α with FTAI 24±2h later or 56±2h (d 9) after PGF2α and FTAI 17±2h later; (3) same as T100 with both injections of 150μg of GnRH (T150); and (4) same as T100 with both injections of 200μg of GnRH (T200). Three sites selected the first option and 3 sites selected the second option for the timing of the second injection of all doses of GnRH. Cows were observed daily for signs of estrus and adverse clinical signs. Cows not returning to estrus had pregnancy diagnosis between 42 and 65d following FTAI. Pregnancies per FTAI (P/FTAI) were analyzed as a binary variable (1 = pregnant, 0 = not pregnant) using a generalized linear mixed model with a binomial error distribution and a logit link function. The statistical model included fixed effects for treatment, random effects of site, site by treatment, enrollment cohort within site, and residual. Parity (first vs. second or greater) was included as a covariate. For demonstration of effectiveness, α=0.05 and a 2-tailed test were used. Fifty-two cows were removed from the study because of either deviation from the protocol, injury, illness, culling, or death. Among the remaining 1,090 cows, 33.9% were primiparous and 66.1% were multiparous. Back-transformed least squares means for P/FTAI were 17.1, 27.3, 29.1, and 32.2% for control, T100, T150 and T200, respectively. The P/FTAI for each GnRH dose differed from that of the control. No differences were detected in P/FTAI between GnRH doses. No treatment-related adverse events were observed. Mastitis was the most frequently observed adverse clinical sign, followed by lameness and pneumonia. This study documents the efficacy and safety of doses of 100 to 200μg of GnRH as the HCl salt when used in Ovsynch programs.
ABSTRACT We have collected broadband spectral energy distributions (SEDs) of three BL Lac objects 3FGL J0022.1−1855 (z = 0.689), 3FGL J0630.9−2406 ( 1.239), and 3FGL J0811.2−7529 (z = 0.774), ...detected by Fermi with relatively flat gigaelectronvolt spectra. By observing simultaneously in the near-infrared to hard X-ray band, we can well characterize the high end of the synchrotron component of the SED. Thus, fitting the SEDs to synchro-Compton models of the dominant emission from the relativistic jet, we can constrain the underlying particle properties and predict the shape of the gigaelectronvolt Compton component. Standard extragalactic background light (EBL) models explain the high-energy absorption well, with poorer fits for high-ultraviolet models. The fits show clear evidence for EBL absorption in the Fermi spectrum of our highest-redshift source 3FGL J0630.9−2406. While synchrotron self-Compton models adequately describe the SEDs, the situation may be complicated by possible external Compton components. For 3FGL J0811.2−7529, we also discover a nearby serendipitous source in the X-ray data, which is almost certainly another lower synchrotron peak frequency ( ) BL Lac, that may contribute flux in the Fermi band. Since our sources are unusual high-luminosity, moderate BL Lacs, we compare these quantities and the Compton dominance, the ratio of peak inverse Compton to peak synchrotron luminosities ( ), with those of the full Fermi BL Lac population.
Little was known about idiopathic laryngotracheal stenosis when it was first described. We have operated on 73 patients with idiopathic laryngotracheal stenosis, have confirmed its mode of ...presentation and response to surgical therapy, and have established long-term follow-up.
Charts of 73 patients treated surgically for idiopathic laryngotracheal stenosis between 1971 and 2002 were retrospectively reviewed.
All patients were treated with a single-staged laryngotracheal resection, with (36/73) and without (37/73) a posterior membranous tracheal wall flap. Nearly all were women (71/73), with a mean age of 46 years (range, 13-74 years). Twenty-eight (38%) of 73 had undergone a previous procedure with laser, dilation, tracheostomy, T-tube, or laryngotracheal operations. After laryngotracheal resection, the majority of patients (67/73) were extubated in the operating room, and 7 required temporary tracheostomies, only 1 of whom was among the last 30 patients. All were successfully decannulated. There was no perioperative mortality. Principal morbidity was alteration of voice quality, which was mild and tended to improve with time. Sixty-seven (91%) of 73 patients had good to excellent long-term results with voice and breathing quality and do not require further intervention for their idiopathic laryngotracheal stenosis.
Idiopathic laryngotracheal stenosis is an entity that occurs almost exclusively in women and is without a known cause. It is not a progressive process, but the timing of the operation is crucial. Single-staged laryngotracheal resection is successful in restoring the airway while preserving voice quality in more than 90% of patients. Protective tracheostomy is now rarely required (1/30). Long-term follow-up shows a stable airway and improvement in voice quality.
The objective of this study was to elucidate the mechanism by which polyamino acids containing L-arginine, L-lysine or L-ornithine cause endothelium-dependent relaxation of bovine intrapulmonary ...artery and vein. Basic but not acidic or neutral polypeptides ranging in average molecular weights from 17 to 225 kDa elicited time- and concentration-dependent relaxation and cyclic GMP accumulation in precontracted rings of artery and vein by endothelium-dependent mechanisms. Vascular responses were markedly inhibited by oxyhemoglobin, methylene blue, or potassium. The basic polyamino acids stimulated the formation and/or release of an endothelium-derived relaxing factor (EDRF) identified as nitric oxide (NO) in perfused segments of both artery and vein as assessed by bioassay. The polyamino acids and A23187 released a similar endothelium-derived NO (EDNO) from artery and vein, as assessed by the similar half-life (3-5 seconds), antagonism by superoxide anion or oxyhemoglobin, enhancement by superoxide dismutase, and lack of influence by indomethacin. The basic polyamino acids elicited potent relaxant responses with EC50 values ranging from 3 x 10(-9) to 2 x 10(-7) M, and a direct correlation was obtained between molecular weight and relaxation potency irrespective of the basic amino acid incorporated. Prolonged contact of arterial or venous rings with basic polyamino acids resulted in the rapid development of marked refractoriness to relaxation and cyclic GMP formation on addition of polyamino acid. Moreover, refractoriness developed to the vascular responses of other endothelium-dependent vasodilators but not to glyceryl trinitrate or isoproterenol. The mechanism of refractory responses was attributed to interference with EDNO formation and release as assessed by bioassay and chemical assay. The hypothesis is forwarded that the basic polyamino acids serve as partial substrates for the enzyme system that catalyzes the conversion of L-arginine to NO. Prolonged contact between substrate and enzyme results in enzyme desensitization and the development of refractoriness or a form of tolerance to vasodilators whose action is mediated by EDNO.
Background We previously reported the results of a randomized placebo-controlled study of egg oral immunotherapy (eOIT) in which 27.5% of subjects achieved sustained unresponsiveness (SU) after ...2 years. Here we report the results of treatment through 4 years and long-term follow-up. Objective We sought to evaluate the efficacy and safety of eOIT in participants treated up to 4 years. Methods Children with egg allergy (5-18 years old) received eOIT (n = 40) for up to 4 years or placebo (n = 15) for 1 year or less. The key outcome was the percentage of subjects achieving SU by year 4. Safety and immunologic assessments were performed, and long-term follow-up questionnaires (LFQs) were administered after study conclusion (LFQ-1) and 1 year later (LFQ-2). Results Of 40 eOIT-treated subjects, 20 (50.0%) of 40 demonstrated SU by year 4. For those subjects still dosing during years 3 and 4, mild symptoms were present in 12 (54.5%) of 22 subjects. At the time of the LFQ, more subjects receiving eOIT (LFQ-1, 23/34 68%; LFQ-2, 21/33 64%) were consuming unbaked and baked egg versus placebo (LFQ-1, 2/11 18%, P = .006; LFQ-2, 3/12 25%, P = .04). Of subjects achieving SU, 18 (90%) of 20 completed the LFQ, with 18 (100%) of 18 reporting consumption of all forms of egg. When compared with subjects not achieving SU, subjects achieving SU had higher IgG4 values ( P = .001) and lower egg skin prick test scores ( P = .0002) over time and a lower median baseline ratio of egg-specific IgE to total IgE (1.1% vs 2.7%, P = .04). Conclusions SU after eOIT is enhanced with longer duration of therapy and increases the likelihood of tolerating unbaked egg in the diet.
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