The Breathmeter - A new laser device to analyze your health

It is widely believed that measurement of molecules in exhaled breath can provide a window into the metabolic state of the human body, detect the presence of cancer, monitor respiratory diseases, assess liver and kidney function, determine exposure to toxins, and possibly, even diagnose schizophrenia. Such conjectures are further supported by recent work performed by researchers at the Pine Street Foundation. Laser spectroscopic techniques, in particular, tunable laser absorption spectroscopy (TLAS), are candidate technologies for breath analysis applications. The paper presents the Breathmeter from Ekips Technologies. The Breathmeter is based on TLAS and consists of four primary components: 1) the laser source module, 2) sample gas cell, 3) optical detector, and 4) associated electronics hardware and software. The optical board layout of the breath meter system was shown. Its applications and future works were also discussed     

Nitric oxide in the contractile action of bradykinin, oxytocin, and prostaglandin F2 alpha in the estrogenized rat uterus

Experiments were performed on uteri from estrogen-primed female rats. Bradykinin (BK) (10(-8) M) significantly augmented biosynthesis of prostaglandin F2 alpha (PGF2alpha) and prostaglandin E2 (PGE2), and this synthesis was completely blocked by NG-monomethyl L-arginine (NMMA) (300 microM), a competitive inhibitor of nitric oxide synthase (NOS). Blockade of prostaglandin synthesis by indomethacin caused rapid dissipation of isometric developed tension (IDT) induced by BK. Blockade of NOS with NMMA had similar but less marked effects. Combining the two inhibitors produced an even more rapid decay in IDT, suggesting that BK-induced NO release maintains IDT by release of prostanoids. The decline of frequency of contraction (FC) was not significantly altered by either indomethacin or NMMA but was markedly accelerated by combination of the inhibitors, which suggests that PGs maintain FC and therefore FC decline is accelerated only when PG production is blocked completely by combination of the two inhibitors of PG synthesis. The increase in IDT induced by oxytocin was unaltered by indomethacin, NMMA or their combination indicating that neither NO nor PGs are involved in the contractions induced by oxytocin. However, the decline in FC with time was significantly reduced by the inhibitor of NOS, NMMA, suggesting that FC decay following oxytocin is caused by NO released by the contractile process. In the case of PGF2alpha, NMMA resulted in increased initial IDT and FC. The decline in FC was rapid and dramatically inhibited by NMMA. Receptor-mediated contraction by BK, oxytocin, and PGF2alpha is modulated by NO that maintains IDT by releasing PGs but reduces IDT and FC via cyclic GMP.     

Multidimensional ultrasonic imaging for cardiology

Previous extensions of two-dimensional ultrasonic imaging to three dimensions used lattice diagrams which give measurement information, but no anatomic detail. The authors conducted three sets of experiments to test the hypothesis that complete acoustic backscatter data should be retained to produce useful information about heart structure and function. First, in vitro compound B-scans were taken under ideal conditions; second, in vitro rotating conventional sector scans were taken to test clinically applicable methods; and third, clinical in vivo rotating conventional sector scans were taken of a human volunteer. It is concluded that the resulting images show details of cardiac anatomy and have great clinical promise. Interactive analysis and surface and volume displays give context and perspective information which should improve diagnostic accuracy, communication with noncardiologists and yield more precise measurements of anatomical structure and function     

A comparison of self-reported drug use with a urine drug screen in a working population.

This study summarized information on 162 workers who completed urine screen and self-report concerning drug use. It is the first to compare self-report of drug use in the workplace with a urine screen in which individual participant (nonaggregate) data were used. The findings indicate that agreement between the 2 methods of drug detection, although statistically significant, is at best only moderate. The level of agreement was consistent for segments of the sample when divided by sociodemographic characteristics. Although urine screen may be the more reliable and accurate method of detecting prevalence of drug use, self-report must be considered to assess drug use histories and the role of other variables. These 2 methods should be considered as complementary assessment techniques; the appropriate method depends on the conditions and purposes of the drug use study. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Gastrointestinal complications following cardiac surgery

This study sought to determine which factors influence the mortality rate in patients developing gastrointestinal complications following cardiac surgery. Between July 1988 and January 1992, 2054 patients underwent cardiac surgical procedures at the Boston University Medical Center. Of these, 29 (1.4%) developed postoperative gastrointestinal complications. The overall mortality rate among these patients was 27% (8/29). Those who died following such complications had a higher incidence of New York Heart Association (NYHA) class IV and unstable symptoms (8/8, 100% versus 3/21, 14%; P < 0.0001), and an increased need for preoperative intra-aortic balloon pump support (4/8, 50% versus 1/21, 5%; P < 0.004). The need for gastrointestinal surgical intervention increased the mortality rate significantly compared with patients managed medically (8/18, 44% versus 0/11, 0%; P < 0.01). Patients with ischemic bowel also had a significantly higher mortality (5/5, 100% versus 3/24, 12%; P < 0.001). It is concluded that most patients with gastrointestinal complications following cardiac surgery can be treated, and with acceptable mortality rates. The presence of unstable symptoms, preoperative intra-aortic balloon pump support, ischemic bowel and the need for gastrointestinal surgical intervention adversely affect mortality.     

LPE growth of crack-free PbSe layers on Si(100) using MBE-Grown PbSe/BaF2CaF2 buffer layers

Crack-free PbSe on (100)-oriented Si has been obtained by a combination of liquid phase epitaxy (LPE) and molecular beam epitaxy (MBE) techniques. MBE is employed first to grow a PbSe/BaF₂/CaF₂ buffer structure on the (100)-oriented Si. A 2.5 μm thick PbSe layer is then grown by LPE. The LPE-grown PbSe displays excellent surface morphology and is continuous over the entire 8×8 mm² area of growth. This result is surprising because of the large mismatch in thermal expansion coefficients between PbSe and Si. Previous attempts to grow crack-free PbSe by MBE alone using similar buffer structures on (100)-oriented Si have been unsuccessful. It is speculated that the large concentration of Se vacancies in the LPE-grown PbSe layer may allow dislocation climb along higher order slip planes, providing strain relaxation.     

A comparison of isokinetic strength testing and gait analysis in patients with posterior cruciate-retaining and substituting knee arthroplasties

Fourteen patients with a posterior-stabilized prosthesis in one knee and a posterior cruciate-retaining prosthesis in the contralateral knee and both scoring good or excellent on the Hospital for Special Surgery (HSS) knee scale were evaluated by isokinetic muscle testing and comprehensive gait analysis at a mean follow-up of 98 months after arthroplasty. The average HSS knee score (93 points) and the average Knee Society score (94 points) were the same for the cruciate-retaining and posterior-stabilized knees. No differences were noted between the cruciate-retaining and the posterior stabilized knees with respect to isokinetic muscle testing parameters (peak torque, endurance, angle of peak torque, and torque acceleration energy) for both quadriceps and hamstrings. No significant differences were found between the cruciate-retaining and the posterior-stabilized knees with regard to gait parameters, knee range of motion, and electromyographic waveforms during level walking and stair climbing. Cruciate-retaining and posterior-stabilized total knee prostheses perform equally well during level gait and stair climbing.     

Adenosine acts by A1 receptors to stimulate release of prolactin from anterior-pituitaries in vitro

Adenosine has been identified in the anterior pituitary gland and is secreted from cultured folliculostellate (FS) cells. To determine whether adenosine controls the secretion of anterior pituitary hormones in vitro, adenosine was incubated with anterior pituitaries. It stimulated prolactin (PRL) release at the lowest concentration used (10(-10) M); the stimulation peaked at 10(-8) M with a threefold increase in release and declined to minimal stimulation at 10(-4) and 10(-3) M. Follicle-stimulating hormone release was maximally inhibited at 10(-8) M, whereas luteinizing hormone release was not significantly inhibited. Two selective A1 adenosine receptor antagonists (10(-7) or 10(-5) M) had no effect on basal PRL release, but either antagonist completely blocked the response to the most effective concentration of adenosine (10(-8) M). In contrast, a highly specific A2 receptor antagonist (10(-7) or 10(-5) M) had no effect on basal PRL release or the stimulation of PRL release induced by adenosine (10(-8) M). We conclude that adenosine acts to stimulate PRL release in vitro by activating A1 receptors. Since the A1 receptors decrease intracellular-free calcium, this would decrease the activation of nitric oxide synthase in the FS cells, resulting in decreased release of nitric oxide (NO). NO inhibits PRL release by activating guanylate cyclase that synthesizes cGMP from GTP; cGMP concentrations increase in the lactotrophs leading to inhibition of PRL release. In the case of adenosine, NO release from the FS cells decreases, resulting in decreased concentrations of NO in the lactotrophs, consequent decreased cGMP formation, and resultant increased PRL release.     

Sigma-1 and sigma-2 sites in rat brain: comparison of regional, ontogenetic, and subcellular patterns

Radioligand binding assay conditions were established for the selective labeling of sigma-1 and sigma-2 sites in membrane homogenates of rat brain. Selective sigma-1 assays were conducted using 5 nM(+)[3H]SKF-10,047 in the presence of 300 nM dizocilpine (MK-801). Selective sigma-2 assays were conducted using 5 nM [3H]DTG in the presence of 1 microM (+)SKF-10,047. Distributions of sigma-1 and sigma-2 binding among brain regions were found to differ. While the brain stem yields the highest level of sigma-1 binding, it yields among the lowest levels of sigma-2 binding. The reverse is true in hippocampal membranes. Different ontogenetic patterns were also observed. Sigma-2 binding decreases substantially during brain development, whereas sigma-1 binding does not vary significantly. Patterns of distribution among subcellular fractions of rat brain homogenates were found to be similar. Both sigma-1 and sigma-2 sites are most enriched in microsomal fractions, and neither is enriched in synaptosomal or mitochondrial fractions. The present results suggest that sigma-1 and sigma-2 sites are distinct entities; they do not appear to be located on a common macromolecule, and they do not represent two different affinity states of a single type of binding site. While the precise subcellular locations of sigma-1 and sigma-2 sites remain to be determined, we conclude that localization of either type of binding site to synaptic regions of plasma membrane or to mitochondria is highly unlikely.