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Localization via received signal strength (RSS) is often employed in cases where the received signal is fairly weak, either due to distance or due to deliberate covert operation or interference avoidance. However, most research on source localization via RSS implicitly assumes that the background noise is negligible, and that parameters of the transmitter and environment are known. Many commercial chipsets provide per-frame RSS measurements obtained when demodulating the signal, which do not include background noise; however, noise can still cause signal outages. In law enforcement, surveillance, and emergency situations, RSS may be obtained more crudely, such as by energy detection, in which case the RSS will include contributions from the background noise as well. This paper proposes new probabilistic RSS models that account for background noise in both types of RSS measurements. We also derive and evaluate maximum likelihood estimators (MLEs) for these new models, as well as for differential RSS, which has hitherto not been rigorously analyzed in the literature. Several of these MLEs are extended to estimate the transmit power and/or path loss if they are unknown. The new models are justified by extensive measured data. [ABSTRACT FROM PUBLISHER]

We have synthesized a C-terminal portion of tracheal antimicrobial peptide (TAP) with 38 amino acids and tested it for efficacy on various clinical isolates of Pseudomonas aeruginosa strains from patients with cystic fibrosis and also on Aspergillus fumigatus. Our results indicate that the synthetic TAP has both potent bactericidal and fungicidal activities and that a combination of TAP and amphotericin B showed strong additive effects of growth inhibition on A. fumigatus. These results suggest that TAP is potentially an effective therapy for Aspergillus and multi-drug-resistant Pseudomonas, pathogens that are often a serious threat to patients with cystic fibrosis. [ABSTRACT FROM PUBLISHER]

Objective: Human beta-defensin (HBD) and the complement system are two important innate immune mechanisms active against a broad range of burn and wound pathogens. However, excessive or uncontrolled complement activation, following thermal injury, contributes to tissue damage. Previous studies from our laboratory suggested a decreased expression of HBD-2 in burn wounds and its absence in burn blister fluid. Prior studies have demonstrated that human neutrophil peptide can bind to the C1q component of the complement system and prevent complement activation. The objective of this study was to determine whether HBD-1 and HBD-2 can also bind to the C1q component and modulate complement activity., Methods: The binding efficiency of HBD-1 and HBD-2 to the C1q component was determined by utilizing dot blot hybridization. The effect of HBD-2 on the activation of the complement system by the classical and alternative pathways was determined by CH50 and AP50 assays. In addition, the ability of HBD-1 and HBD-2 to inhibit C1q activity was predicted by a comparison with known C1q inhibitor peptide 2J in a DNAStar computer modeling study., Results: C1q binding to HBD-2 was strong, whereas C1q binding to HBD-1 was weak. HBD-2 inhibits the classical pathway significantly without affecting the alternative pathway. In addition, a computer modeling study also revealed structural homology of HBD-2 with known C1q inhibitory sequences of HBD-2., Conclusion: HBD-2 inhibits the classical pathway. The replacement of missing defensin, a natural inhibitor of the complement system, may have a dual protective role not only as an antimicrobial agent but also in providing protection against uncontrolled activation of the complement system.

Study Objectives: To exclude genetic linkage between the beta(2)-adrenoceptor gene and asthma, allergy, and methacholine airway hyperresponsiveness., Design: The current study used six distinct intragene markers within the beta(2)-adrenoceptor gene, and evaluated genetic linkage between the beta(2)-adrenoceptor and asthma, allergy, or methacholine airway hyperresponsiveness in eight multiplex families., Patients: Forty-nine members of eight multiplex families with a high incidence of asthma., Interventions: Phenotypes were characterized by history, physical examination, skin testing, pulmonary function tests, and methacholine inhalational challenge. Genetic loci were identified using restriction fragment length polymorphisms, denaturing gradient gel electrophoresis, and restriction enzyme digest of polymerase chain reaction-amplified fragments of the beta(2)-adrenoceptor gene., Measurements and Results: Nonparametric analysis using computer analysis software found no evidence for linkage between these markers within the beta(2)-adrenoceptor gene and asthma. Parametric exclusion analysis using a dominant inheritance model resulted in large negative lod scores (- 6.74, - 19.44, and - 49.9, respectively) for tight linkage between asthma, allergy, or methacholine airway hyperresponsiveness and these polymorphic markers., Conclusions: These results indicate that asthma, allergy, and methacholine airway hyperresponsiveness are not linked to a dominant beta(2)-adrenoceptor gene with strong effect in these eight families with an inherited pattern of asthma.

The CorA transport system is the primary Mg2+ influx system of Salmonella typhimurium and Escherichia coli. The CorA protein has no homology to any other known family of proteins. It has an unusual membrane topology, with a large, soluble, highly charged periplasmic N-terminal domain with three transmembrane segments in a shorter, hydrophobic C-terminal domain. Previous phenotypic and molecular data had suggested that this transport system was widespread in the Bacteria. In this report we show that CorA is virtually ubiquitous in the Bacteria and Archaea, forming a distinct family of transport proteins. Genomic sequences to date have revealed at least 22 members of the CorA family in the Bacteria and the Archaea, with 6 more distant members in the yeasts. Only three of the smallest bacterial genomes lack a CorA homologue. Strikingly, phylogenetic analysis does not show clustering by related species or even within kingdom. Several species of Bacteria contain two or even three CorA paralogues. Within species, these paralogues are not closely related, however, and we suggest that they might have distinct transport functions. A multiple alignment suggests three extended consensus regions within the N-terminal soluble domain of CorA, which is predicted to be virtually all alpha-helical. A fourth consensus region includes the last 20 residues of the soluble domain and continues through the entire membrane domain. The first half of this last consensus domain may form an amphipathic alpha-helix that extends from the soluble domain into the first transmembrane segment. The degree of charge in the first transmembrane segment is quite variable, and we suggest that this transport family may include members with only two rather than three transmembrane segments. If so, this would place the N-terminal soluble domain on different sides of the membrane in different members of the family. We suggest that the CorA Mg2+ transport system forms the major Mg2+ uptake system in the Bacteria and Archaea but that some family members may have a function other than Mg2+ transport.

Background: Surgical procedures for emphysema have been proposed and in many settings resulted in significant improvement in dyspnea and function. The most prevalent surgical problem in all series is prolonged postoperative air leak., Methods: One hundred twenty-three patients undergoing stapled thoracoscopic unilateral lung volume reduction operation were prospectively randomized to receive either no buttressing of their staple lines or buttressing of all staple lines with bovine pericardial strips., Results: The two groups were comparable in preoperative risks and in the severity of their emphysema. Postoperative complications were identical in the two groups with respect to pneumonia, empyema, and wound infection; however, there was a significant difference in the duration of postoperative air leaks. Those having the pericardial strips used to buttress their staple lines had chest tubes removed 2.5 days sooner and were discharged from the hospital 2.8 days sooner as a result. The cost data revealed that because of the cost of the pericardial sleeves, the overall hospital charges were almost identical for the two groups ($22,108 bovine, $22,060 no bovine) in spite of the shortened hospital stay., Conclusions: The use of bovine pericardial sleeves to buttress the staple lines in thoracoscopic unilateral lung volume reduction operation results in a shorter duration of postoperative air leaks. Total hospital charges were comparable in the two groups as the 2.8 days saved in the hospital were offset by the cost of the pericardial sleeves.

1. The growth inhibitory factor (GIF) is a 68-amino acid protein which is capable of inhibiting the growth of neuronal cells in vitro. 2. We have cloned and sequenced the 5'-flanking region of the mouse GIF gene, which spans from the transcriptional initiation site to the -1854 nucleotide. 3. This region contains sequences homologous to hgcs, SPE, and the JCV silencer domain that functions in a glial cell specific manner. This region also contains two metal responding elements and putative binding sites for AP-1, AP-2, Sp-1, SP-2, NF-1, and CREB. 4. An analysis of the reporter plasmids containing the various regions of the 5'-flanking sequence revealed that the region indeed functioned in a tissue-specific manner in glial cells and that the region between -328 and 175 is responsible for suppression, while the region between -175 and -49 is involved in the activation of gene expression.

We have chemically synthesized tracheal antimicrobial peptide (TAP) with 38 amino acids and examined efficacy of the peptide on various organisms. The synthetic peptide showed potent bactericidal effect on both gram positive and negative bacteria. The action of bactericidal effect was relatively quick and 99.9% of E. coli cells were killed within 90 minutes at a concentration of 2.5 micrograms/ml of TAP. The peptide also showed antifungal activity against both mycelia (Aspergillus fumigatus) and yeast (Candida albicans) forms of fungi. Our domain analysis with a series of synthetic peptides of various lengths indicates that 17 amino acid residues of the C-terminal end is the minimum functional domain of the bactericidal activity.

Background: Kutapressin (KU), a porcine liver extract with bradykinin-potentiating effects but no vitamin B 12 activity, has been used in the treatment of Herpes zoster. We examined a phenol-free preparation of this drug for in vitro activity against Epstein-Barr Virus (EBV)., Materials and Methods: Immortalization-inhibition assays were used to assess EBV infectivity. Mitogen stimulation and cell viability assays were used to assess kutapression toxicity. Lytic replication assays and flow cytometry were used to assess the mechanism of drug activity., Results: Seventy-five hundred mcg/ml of KU blocked the infection of 2 x 10(5) human umbilical cord mononuclear cells when added together with two strains of EBV (B95-8 and FF41). Doses as low as 250 mcg/ml were occasionally effective as well. Unlike acyclovir, KU does not inhibit viral DNA polymerase nor does it appear to compete with EBV as it binds to its receptor on the B-cell surface., Conclusions: The mechanism whereby KU may inhibit EBV immortalization remains to be determined. KU, a drug which is safe in humans, deserves further study as an agent with potential to block EBV-induced immortalization of B-lymphocytes.

The recently discovered human herpesvirus-6 (HHV-6) is being associated with an increasing number of conditions in which there is evidence of immunologic dysfunction. A number of widely available antiviral agents have shown little or no activity against the virus. We found that Kutapressin (KU), a drug that has been available to practicing physicians for over 50 years, has potent, previously unexpected antiviral effects. Cells known to allow replication of HHV-6 were infected with the virus, under various conditions. Either pretreatment of the cells prior to infection or treatment shortly after infection, inhibited viral replication by > 90%. Indirect evidence suggests that KU may inhibit viral attachment to cellular receptors, and inhibit intracellular maturation of the virus. Given these in vitro findings, and the low frequency of toxicity reported with the use of KU, clinical trials of this drug in patients with evidence of reactivated HHV-6 infection would seem to be warranted.

A polyhydroxy alkaloid has been isolated from the seeds of the African legume Angylocalyx pynaertii and identified as a 2-hydroxymethyl-3,4-dihydroxy-5-methylpyrrolidine by ms and 1H- and 13C-nmr spectroscopy. The absolute stereochemistry was established, by a stereochemically unambiguous synthesis from diacetone glucose, as 2,5-imino-1,2,5-trideoxy-D-mannitol, which may also be regarded as 2R,5R-dihydroxymethyl-3R,4R-dihydroxypyrrolidine (DMDP) [2] in which a hydroxymethyl group is deoxygenated, i.e., 6-deoxy-DMDP [1]. Whereas the structurally related polyhydroxypyrrolidine alkaloids which have previously been discovered are inhibitors of alpha- and beta-glucosidase, 6-deoxy-DMDP is unique in inhibiting beta-mannosidase. In addition to this novel alkaloid and 2-hydroxymethyl-3,4-dihydroxypyrrolidine [3], previously shown to be present in several Angylocalyx species, the known piperidine alkaloids deoxymannojirimycin [4] and fagomine [5] were identified for the first time as constituents of An. pynaertii seeds.

Dihydroxypropyl theophylline (dyphylline) was administered by aerosol in a single dose of 250 mg aerosolized over five minutes to two asthmatic volunteers and in a single dose of 375 mg aerosolized over ten minutes to two other asthmatic volunteers. Serial spirometry was then performed. Marked bronchospasm occurred within ten minutes in two of the subjects, and developed more slowly in another. One subject demonstrated no significant change. Aerosolized dyphylline solution was not an effective bronchodilator, using the methods described in this study.

This study compared the bronchodilator effect in experimental canine asthma of dyphylline administered by aerosol and intravenous routes in doses producing equivalent concentrations of the drug in the plasma. Pulmonary resistance (RL) was calculated from simultaneous measurements of pressure and flow during fixed-volume controlled ventilation at the same peak flow and corrected for elastic recoil pressure. Dynamic compliance (Cdyn) was calculated by dividing tidal volume by the change in pressure measured between points of zero flow. Concentrations of dyphylline in the plasma were measured using high-performance liquid chromatographic techniques. Rates of infusion of dyphylline were determined from values for clearance observed in preliminary experiments with intravenous injection. Prior to exposure to antigen, RL and Cdyn were not significantly different in control and dyphylline-treated dogs. Following challenge, with antigen RL increased by 8.3 +/- 2.6 times (mean +/- SE) in untreated dogs but only by 2.4 +/- 0.4 times in dyphylline treated dogs. Levels of dyphylline in the plasma averaged 4.2 micrograms/ml +/- 0.6 micrograms/ml at the end of the ten-minute period of aerosol administration and remained at that level for 60 minutes. At equivalent plasma levels (4.3 micrograms/ml +/- 0.3 micrograms/ml), infusion of dyphylline did not significantly after the response to Ascaris antigen, whereas dyphylline administered by the aerosol route markedly attenuated the response.

A five-year update of a previous 20-year study of adolescent pregnancy is presented. For the 25-year period, data were collected on 2,789 adolescents. Prematurity and low birth weight infants continue to have a high incidence in adolescent pregnancy. This study found that there has been a significant decrease in preeclampsia and toxemia of pregnancy and a large increase in the incidence of cesarean section.

Chronic indwelling catheters in the maternal femoral artery and vein, fetal carotid artery and jugular vein, and amniotic cavity of a pregnant rhesus monkey permitted administration of sodium valproate (NaVPA) and collection of timed samples of maternal and fetal blood and amniotic fluid. After a single IV dose (50 mg/kg) to the mother, a rapid distribution phase (t1/2 alpha = 0.5 minute) was followed by a biphasic decline in concentration in maternal blood (t1/2 beta = 31 minutes, t1/2 gamma = 390 minutes). VPA appeared rapidly in fetal blood, reached a concentration slightly higher than in maternal blood by 15 minutes, and thereafter declined in parallel with the concentration in maternal blood. Terminal fetal/maternal ratios of blood concentration of VPA were about 1.3. Similar patterns of decline were observed after NaVPA was given IV to the fetus. A multicompartment first-order materno-fetal pharmacokinetic model is presented. Tissue distribution studies in the fetus showed that VPA concentration was highest in blood; moderate in heart, liver, spleen, kidney, and skeletal muscle; and low in brain.

The concentration profile of valproic acid (VPA) in bile-exteriorized rats given an i.v. bolus of 15 mg sodium valproate (NaVPA) per kg has been previously shown to exhibit a limited distribution phase and first-order elimination kinetics (two-compartment open model). At a higher dose of 150 mg NaVPA/kg, the initial elimination was non-linear (capacity-limited). Using an 'iterative modified Euler integration technique,' the results have been fitted to a pharmacokinetic model which allows for both two-compartment redistribution of drug as well as saturable Michaelis-Menten elimination kinetics. A combined pharmacokinetic model of this type has not been previously described.

The pharmacokinetics and urinary excretion of intravenously administered 7-(2,3-dihydroxypropyl) theophylline (dyphylline), were studied in a 37-yr-old asthmatic woman with ethylene diamine sensitivity who manifested intolerance to intravenous aminophylline on three separate occasions. In this subject, intravenously administered dyphylline was tolerated very well and was effective in the subsequent management of acute bronchospastic episodes. Dyphylline was significantly concentrated in the urine. This, coupled with its rapid clearance, suggests potential clinical application in patients with hepatic dysfunction. Though aminophylline sensitivity is rare, ethylene diamine sensitivity should be considered in untoward reactions to this drug.

Methods for obtaining an exact least squares fit of the one and two compartment models have not been previously described. The multi compartment polyexponential pharmacokinetic models have classically been fit to data using nonlinear regression programs such as NonLin (Metzler, 1969). The two compartment open model, for example, can be fit to least squares regression with equation 1 by iteratively varying A, alpha, B, and beta. Y = Ae(-alpha t) + Be(-beta t).

Twenty-seven firemen were divided into three groups. Group a performed one hour of unsupervised exercise three to four times per week. Group C performed similar but supervised exercise, and group B had no exercise program. After 12 weeks group A showed an average increase of 19% in maximal oxygen uptake (VO2 max); group C, an average increase of 20%; and group B, an average decrease of 2%. One-minute postalarm heart rates showed a correlation with VO2 max (p = 15). A serious cardiac arrhythmia was found in the oldest fireman. Careful physical screening followed by an on-the-job exercise program increases aerobic reserve. We suggest that postalarm tachycardia is dampened. This may lessen the risk of heart disease occurring in the postalarm period.