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Antenna engineers discussed antenna innovations such as new designs, materials, and applications at the 2008 Antenna Applications Symposium. Topics in antenna research and development included cost reduction and performance enhancement.

Since Claims published an article on automobile black boxes in August 2002, significant developments have been made in black box technology, or event data recorders (EDRs). Because nearly 23 percent [...]

When the term black box is used, the first thing that often comes to mind is an aircraft's flight data recorder. These devices are the focus of aircraft crash investigations [...]

α-Cobratoxin (Cbtx), the neurotoxin isolated from the venom of the Thai cobra Naja kaouthia, causes paralysis by preventing acetylcholine (ACh) binding to nicotinic acetylcholine receptors (nAChRs). In the current study, the region of the Cbtx molecule that is directly involved in binding to nAChRs is used as the target for anticobratoxin drug design. The crystal structure (1YI5) of Cbtx in complex with the acetylcholine binding protein (AChBP), a soluble homolog of the extracellular binding domain of nAChRs, was selected to prepare an α-cobratoxin active binding site for docking. The amino acid residues (Ser182-Tyr192) of the AChBP structure, the binding site of Cbtx, were used as the positive control to validate the prepared Cbtx active binding site (root mean square deviation < 1.2 Å). Virtual screening of the National Cancer Institute diversity set, a library of 1990 compounds with nonredundant pharmacophore profiles, using AutoDock against the Cbtx active site, revealed 39 potential inhibitor candidates. The adapted in vitro radioligand competition assays using [3H]epibatidine and [125I]bungarotoxin against the AChBPs from the marine species, Aplysia californica(Ac), and from the freshwater snails, Lymnaea stagnalis(Ls) and Bolinus truncates(Bt), revealed 4 compounds from the list of inhibitor candidates that had micromolar to nanomolar interferences for the toxin binding to AChBPs. Three hits (NSC42258, NSC121865, and NSC134754) can prolong the survival time of the mice if administered 30 min before injection with Cbtx, but only NSC121865 and NSC134754 can prolong the survival time if injected immediately after injection with Cbtx. These inhibitors serve as novel templates/scaffolds for the development of more potent and specific anticobratoxin.

We have previously described a series of antagonists that showed high potency and selectivity for the NK1 receptor. However, these compounds also had the undesirable property of existing as a mixture of interconverting rotational isomers. Here we show that alteration of the 2-naphthyl substituent can modulate the rate of isomer exchange. Comparisons of the NK1 receptor affinity for the various conformational forms has facilitated the development of a detailed NK1 pharmacophore model.

Through optimization of compounds based on the dual NK1/NK2 antagonist ZD6021, it was found that alteration of two key regions could modulate the balance of NK1 and NK2 potency. Substitution of the 2-naphthalene position in analogues of ZD6021 resulted in increased NK1 potency and thus afforded NK1 preferential antagonists. Alterations of the piperidine region could then increase NK2 potency to restore dual NK1/NK2 selectivity. Through these efforts, three novel receptor antagonists from a single chemically related series were identified; two are dual NK1/NK2 antagonists, and the third is an NK1 preferential antagonist. In this paper, the factors affecting the balance of NK1 and NK2 selectivity in this series are discussed and the in vitro and in vivo properties of the novel antagonists are described.

Siliranes undergo palladium-catalyzed reactions with alkynes to give a variety of silacycles depending upon the alkyne. When terminal and electron-poor alkynes (DMAD and methyl 2-butynoate) are employed, silole formation is favored. Silirenes are formed preferentially when more electron-rich internal alkynes are involved. Control experiments provide evidence that palladium(0) species are the active catalysts. By evaluation of product distributions in these reactions, a catalytic cycle that accounts for the production of all silacycles can be proposed.

Abstract: Objective. To investigate the magnetic resonance imaging (MRI) features of allografts at various time intervals after surgery in patients with osteoarticular allografts. Design and patients. Sixteen patients who were treated with osteoarticular allografts and who were followed over time with MRI studies as part of their long-term follow-up were retrospectively selected for this study. T1-weighted images were obtained both before and after gadolinium administration along with T2-weighted images. All images were reviewed by an experienced musculoseletal radiologist, with two other experienced radiologists used for consultation. Imaging studies were organized into three groups for ease of discussion: early postoperative period (2 days to 2 months), intermediate postoperative period (3 months to 2 years), and late postoperative period (greater than 2 years). Results. In the early postoperative period, no gadolinium enhancement of the allograft was visible in any of the MR images. A linear, thin layer of periosteal and endosteal tissue enhancement along the margin of the allograft was visible in images obtained at 3–4 months. This enhancement apeared gradually to increase in images from later periods, and appears to have stabilized in the images obtained approximately 2–3 years after allograft placement. The endosteal enhancement diminished after several years, with examinations conducted between 6 and 8 years following surgery showing minimal endosteal enhancement. However, focal enhancement was noted adjacent to areas of pressure erosion or degenerative cysts. All the cases showed inhomogeneity in the marrow signal (scattered low signal foci on T1 with corresponding bright signal on T2), and a diffuse, inhomogeneous marrow enhancement later on. Conclusion. We have characterized the basic MRI features of osteoarticular allografts in 16 patients who underwent imaging studies at various time points as part of routine follow-up. We believe that the endosteal and periosteal enhancement observed on MRI during the first few months to 2 years following surgery represents vascular ingrowth and early skeletal repair. The zone of periosteal enhancement could also include the new bone laid on the surface of the allograft through which the soft tissues bind to the cortex. The exact reason for the inhomogeneity in the marrow signal, and the diffuse, inhomogeneous marrow enhancement is not clear. This may represent saponified and/or necrotic marrow fat interspersed with the fibrovascular tissue. The features noted here should provide radiologists with useful information regarding imaging characteristics they can expect to see in other allograft replacement patients.

Adult male and female rats were fasted for 1, 2, or 3 days to determine its effect on circulating and endogenous fuels available to the heart. Liver glycogen was depleted within the first 24 h of food restriction. Plasma glucose decreased approximately 2.5 mM in both sexes during the 3 days. Fasting significantly increased plasma beta-hydroxybutyrate to approximately the same level in female and male rats. Plasma free fatty acid (FFA) increased approximately 0.2 mM in both groups during the first 24 h without food and remained elevated over the next 2 days. FFA concentrations were higher in fed female than in fed male rats and remained significantly higher in female rats throughout the experimental period. Myocardial glycogen increased 64% during the first 2 days of fasting in the male rats and stayed elevated on the third day of fasting. In contrast, heart glycogen of female rats remained unchanged from an initial value of 3.13 mg/g throughout the 3-day fasting period. Endogenous triglyceride (TG) of male rats decreased from 2.14 +/- 0.09 to 1.41 +/- 0.21 mumol/g during the first 24 h without food and remained at that level during the second and third days. Heart TG in female rats fell progressively from 2.36 +/- 0.19 to 1.02 +/- 0.12 mumol/g during the fasting period. Cardiac FFA were higher in female than in male animals throughout the entire experiment. These data indicate that quantitative and qualitative metabolic differences exist between male and female rats stressed by fasting.(ABSTRACT TRUNCATED AT 250 WORDS)

We calculate direct CP-violating rate asymmetries in chargedB→PP andB→VP decays arising from the interference of amplitudes with different strong and CKM phases. The perturbative strong phases develop at order αs from absorptive parts of one-loop matrix elements of the next-to-leading logarithm corrected effective Hamiltonian. CPT constraints are maintained. Based on this model, we find that partial rate asymmetries between charge conjugateB± decays can be as high as 20% for certain channels with branching ratios in the 10−6 range. Because the threshold lies so close to the physical momentum scale, the asymmetries depend sensitively on the model assumptions used to evaluate the imaginary parts of the matrix elements, in particular, on the internal momentum transfer. The charge asymmetries of partial rates would provide unambiguous evidence for direct CP violation.

Changes in profiles of serum luteinizing hormone (LH), follicle stimulating hormone (FSH) and testosterone and in mating performance and ejaculate volume have been determined in Finnish Landrace (Finn) and Managra Synthetic (Line-M) rams during the ovine breeding season. In early August, mid-September, early November and mid-December four rams of each breed were bled by venipuncture from the jugular vein at 20-min intervals for two 8-hr periods. Rams were bled while in the absence (control period) and presence (mating period) of ewes in estradiol-induced estrus. An ejaculate was also collected from either five or six of the rams during these months. Aliquots of serum were assayed for LH, FSH and testosterone by radioimmunoassay. Testosterone concentrations in seminal plasma were also determined.Episodic increases in serum levels of LH and testosterone were evident in all rams during each 8-hr period, while FSH fluctuated very little from baseline concentrations (usually <50%). Pulses of LH were consistently followed by elevations in testosterone which peaked within 60 minutes. Progressive changes in the profiles of serum LH and testosterone occurred in rams of both breeds as the breeding season advanced. Peaks in LH became more frequent and decreased in height, and the number and height of the testosterone peaks increased. Serum FSH concentrations were highest in September.Mating activity was associated with increases in the frequency of LH and testosterone peaks in August and September. The number of matings per 8 hr and ejaculate volume increased between early August and early November; both were highest in November when the level of serum testosterone was maximal. Mating performance and mean testosterone concentration (control period) were positively correlated within rams across months (r = .90, P<.01) and between rams only in August (r = .76, P<.05). Monthly changes in testosterone concentration in seminal plasma were moderate compared with those in serum. Direction changes in seminal plasma testosterone were similar to those in serum FSH.

Basal urinary samples were obtained from 60 finalists prior to the official weigh-in at the 1972 state high school wrestling championships. None of the subjects had medical histories of kidney disease, or had exercised, consumed food or liquid for at least 8 hours prior to measurement. Samples were also obtained from a similarly aged group of 45 non-wrestlers. The results demonstrated that the urinary profiles of the two groups differed significantly with regard to specific gravity, pH, osmolarity, sodium and potassium electrolyte concentrations, creatinine, protein and ketone content. These findings suggested that at the time of weigh-in the wrestlers were in a dehydrated state and that the high urinary levels of potassium warrant medical examination and concern for the possible existence of renal ischemia.

Colchicine injection was used as a tool to potentiate the increase in intracellular lipoprotein lipase (type L hormone-sensitive lipase) activity normally seen with fasting to determine if elevation of enzyme activity by this method produced a reduction in endogenous triacylglycerol (TG) in rat heart. Both fasting and fasting+colchicine treatment increased total lipoprotein lipase (LPL) activity from a control value of 80 units/g to approx. 144 units/g. The initial control value was obtained at 08:00 h after overnight feeding and the final values were obtained at 17:00 h, after 9 h of fasting. Fasting alone increased activity in both the capillary-bound LPL and type L hormone-sensitive lipase (HSL) fractions of cardiac muscle. In contrast, colchicine treatment, by blocking the export of enzyme from the cell as a result of microtubular disruption, restricted the increase in enzyme activity to the intracellular fraction of the heart. There was a highly significant (P less than 0.001) negative relationship (r = −0.73) between type L HSL activity and TG content in hearts of fasting and fasting+colchicine-treated rats. At a time when type L HSL activity was increased and TG content decreased, the cyclic AMP concentration of heart remained unchanged, ruling out the possibility that cyclic AMP might be activating any one of the identified cardiac TG lipases. These data provided indirect evidence that type L HSL is ‘seeing the intracellular TG droplet’ and that this enzyme may play a role in the regulation of myocardial lipolysis.

1. Adrenaline has a biphasic effect on intracellular lipoprotein lipase activity and on endogenous triacylglycerol content in heparin-perfused heart. 2. A high concentration of adrenaline (1 microM in the perfusion buffer) activated endogenous lipoprotein lipase activity and, at the same time, decreased intracellular triacylglycerol stores. 3. In contrast, a low concentration (0.005 microM-adrenaline) inhibited intracellular lipoprotein lipase activity. Under these conditions, cardiac triacylglycerol content was elevated above control values. 4. Perfusing the heart with high and low concentrations of 3-isobutyl-1-methylxanthine elicited a biphasic effect on endogenous lipoprotein lipase activity and triacylglycerol content similar to that seen with adrenaline treatment. 5. The effect of adrenaline on intracellular lipoprotein lipase activity appears to be mediated by cyclic AMP through protein kinase. 6. A possible role for intracellular lipoprotein lipase in the regulation of endogenous triacylglycerol in rat heart is proposed.

Four male pygmy goats were 9 months of age when assigned to this experiment. They were maintained for 1 year beginning in June 1975 under natural photoperiod changes characteristic of southern Canada and ambient barn temperatures ranging from 5 to 25 C. During the third week of each month, bucks were bled from a jugular vein by venipuncture at 30-min intervals for either 12 or 24 hr (August, November, February and May). Sera were assayed for luteinizing hormone (LH), follicle stimulating hormone (FSH), prolactin (PRL) and testosterone (T) by radioimmunoassay. Both LH and T were secreted episodically, and increases in serum LH were generally followed by increased serum T concentrations which peaked within 60 minutes. Mean serum LH, T and PRL concentrations fluctuated considerably over the 24-hr periods with peak PRL concentrations generally occurring during the dark period. However, serum FSH concentrations did not show a pulsatile profile and variations over the 24-hr were minimal.Serum LH and T increased with decreasing daylength and attained maximum mean values (± SE) in October of 1.9 ± .5 ng NIH-LH-S14/ml and 15.4 ± .9 ng/ml, respectively. These increases were a result of higher baseline levels and peak frequencies. Lowest mean serum concentrations of LH (.4 ± ,1 ng/ml) and T (2.3 ± .5 ng/ml) occurred in November and June, respectively. Serum FSH increased slightly in September, but the highest concentration occurred in April (67.8 ± 4.4 ng NIH-FSH-S6/ml). Changes in serum PRL concentration paralleled changes in daylength (r = .58, P<.05). Seasonal changes in serum concentrations of LH, PRL, and T in the male pygmy goat follow closely the changes that have been reported for rams, which are also a seasonal breeder under temperate climatic conditions.

OSCAI, L. B., J. GORSKI, W. C. MILLER, and W. K. PALMER. Role of the alkaline TG lipase in regulating intramuscular TG content. Med. Sci. Sports Exerc., Vol. 20, No. 6, pp. 539–544, 1988. Three TG lipases have been identified in muscle (i.e., acid, neutral, and alkaline), but as yet we do not know which enzyme is responsible for tissue TG hydrolysis. Over the past 8 yr, work in our laboratory has focused on intracellular lipoprotein lipase (LPL). The results show that this lipase is regulated by the classical cAMP cascade and that the activity of this enzyme is inversely related to endogenous TG concentration. Using these results as a foundation we plan to examine molecular mechanisms involved in the synthesis, compartmentalization, and transport of the alkaline TG lipase. Further, the evidence suggests that this enzyme may be regulated by protein phosphorylation mediated by cyclic AMP-dependent protein kinase. We plan to test this possibility

We study the exclusive semileptonicD meson decaysD?K+p+l+?. For this we develop the general formalism for the joint angular distribution of the charged lepton and theK meson and calculate the helicity dependent decay widths which determine the full angular distribution for several models withK*(892) andK0*(1430) intermediate state with nonresonant background terms calculated from chiral Lagrangians.

We calculate branching ratios and the polarization in the decay ofB mesons to two vector mesons using heavy quark symmetries to evaluate the current matrix elements.

Novel arylpiperazines were identified as α1-adrenoceptor (AR) subtype-selective antagonists by functional in vitro screening. 3-[4-(ortho-Substituted phenyl)piperazin-1-yl]propylamines were derivatized with N,N-dimethyl anthranilamides, nicotinamides, as well as carboxamides of quinoline, 1,8-naphthyridine, pyrazolo[3,4-b]pyridine, isoxazolo[3,4-b]pyridine, imidazo[4,5-b]pyridine, and pyrazolo[1,5-a]pyrimidines. Strips of rabbit bladder neck were employed as a predictive assay for antagonism in the human lower tract. Rings of rat aorta were used as a “negative screen” for the test antagonists. Binding to α1-ARs was relatively sensitive to size and electronic features of the arylpiperazine portion of the antagonists and permissive to these features on the heteroaryl carboxamide side. These structure−affinity findings were exploited to produce nicotinamides (e.g. 13ii and 25x) and pyrazolo[3,4-b]pyridines (e.g. 37f and 37y) ligands with nanomolar affinity at the α1-AR subtype prevalent in the human lower urinary tract (pA2 values:  8.8, 10.7, 9.3, and 9.9, respectively) and displaying 2−3 orders of magnitude selectivity over the α1D-AR.

Meningococcal disease is normally suspected on clinical grounds and is confirmed by isolation of Neisseria meningitidis bacteria from blood or cerebrospinal fluid or, more recently, by serology or PCR of cerebrospinal fluid. Achieving confirmation of a clinical diagnosis of meningococcal disease has become more difficult in the last few years. The pre-hospitalization administration of parenteral benzylpenicillin normally renders blood cultures sterile, and lumbar puncture is undertaken less frequently, especially in young children. We evaluated PCR for the detection of meningococcal DNA in 80 blood samples taken from patients with known or suspected meningococcal disease or from patients with other diagnoses (negative controls). Both the sensitivity and the specificity of the test were 100% for patients with confirmed cases of meningococcal disease when the blood buffy coat was used (83 to 100% sensitivity and 87 to 100% specificity with 95% confidence limits). Positive PCR results could be obtained from both blood buffy coat and serum samples. Sensitivity was unaffected by prior antibiotic treatment. PCR is a rapid, sensitive test that may be used to confirm a diagnosis of meningococcal disease by using peripheral blood samples. Introduction of this test into clinical laboratories may in some cases obviate the need for lumbar puncture to be performed on patients with suspected meningococcal disease. Our results demonstrate that a substantial number of cases of meningococcal disease are not confirmed by conventional techniques and remain undiagnosed. If the PCR test described here was widely applied, the number of cases of meningococcal disease ascertained might rise by as much as 60% greater than that recognized at present. It is likely that we are in a prevaccination era for meningococcal disease. Better case ascertainment is urgently required to assess the need for vaccines, to determine their costs and benefits, and to monitor their efficacies.

There have been few studies of physiological importance on the regulation of somatostatin by hormones. We have studied the effect of the synthetic glucocorticoid dexamethasone on somatostatin production in the human medullary thyroid carcinoma TT cell line, a model for somatostatin production by the parafollicular cell. Dexamethasone inhibited somatostatin production in a dose-related manner with a maximal effect at a concentration of 10(-6) M. TT cells treated with dexamethasone (10(-6) M) showed an almost complete inhibition of somatostatin peptide production by 48 h of treatment. Molecular sizing chromatography demonstrated a decrease in both the probable somatostatin precursor (13,000 dalton) and the fully processed peptide. Analysis of mRNA content by hybridization revealed that dexamethasone also caused a decrease in detectable somatostatin mRNA. The hybridizable somatostatin mRNA decreased to approximately 50% of basal levels within 12 h of treatment. Northern blot hybridization showed a decrease in a single RNA species representing mature somatostatin mRNA. Dose-response experiments revealed inhibition of both peptide and mRNA at concentrations from 1 X 10(-8) to 1 X 10(-5) M dexamethasone. Four days after withdrawal from dexamethasone treatment, peptide and mRNA levels were higher than dexamethasone-treated controls. The sex steroid estradiol had no inhibitory effect on somatostatin production. These results suggest a potential regulator of somatostatin production and provide a system for the study of somatostatin gene regulation.