Miniaturized carbon monoxide sonde for atmospheric measurements

The design and test results of a simple carbon monoxide detector based on the reducing gas detector principle are presented. This instrument has several features which distinguish it from similar carbon monoxide analyzers, all of which contribute to its usefulness on small airborne platforms such as kites, balloons, and light aircraft. Compact size, battery operation, low cost, and light weight are among the most important improvements made over to earlier systems. The instrument fits a package 10 x 20 x 25 cm, has a mass of 2.0 kg, and consumes an average of 20 W of power. This instrument will, therefore, offer a means of incorporating carbon monoxide measurements in recoverable or disposable balloon sondes. The instrument makes an independent measurement of carbon monoxide every 8 s, with a sensitivity of 3 ppbv carbon monoxide (limit of detection for S/N = 3) and a precision of 4%.     

The use of exhaled carbon monoxide for the diagnosis of carbon monoxide poisoning. A case report

Antigliadin antibodies (AGA) mark celiac disease, but AGA are also encountered in IgA-nephritis, psoriasis, sickle-cell anemia, hepatic disorders, juvenile rheumatoid arthritis, autoimmune thyroidism and in persons who occupationally contact great amounts of wheat. AGA IgA and/or IgG were registered in 19 of 60 subjects (51 adults and 9 children) with various immunomediated diseases without symptoms of celiac disease: in 4 cases of chronic active hepatitis, in 2 of 4 cases of chronic persistent hepatitis, in 4 of 16 cases of rheumatoid arthritis, in 3 of 19 cases of IgA-deficiency, in 1 of 8 cases of SLE, in 2 cases of postvaccine reaction, in all the single cases of juvenile rheumatoid arthritis, focal scleroderma, macroglobulinemia. IgA only occurred in in 6 patients, IgG- in 6 patients, both IgA and IgG in 7 patients. The most pronounced positive reaction to AGA was recorded in 8-year-old girl with juvenile rheumatoid arthritis. The emergence of AGA in immunomediated diseases may be attributed to the response to food protein in pathological conditions and is often unrelated closely with celiac disease.     

Diffusing capacity of the lung for carbon monoxide

A phage-display technology was used to produce a single-chain Fv antibody fragment (scFv) from the 30AA5 hybridoma secreting anti-glycoprotein monoclonal antibody (MAb) that neutralizes rabies virus. ScFv was constructed and then cloned for expression as a protein fusion with the g3p minor coat protein of filamentous phage. The display of antibody fragment on the phage surface allows its selection by affinity using an enzyme-linked immunosorbent assay (ELISA); the selected scFv fragment was produced in a soluble form secreted by E. coli. The DNA fragment was sequenced to define the germline gene family and the amino-acid subgroups of the heavy (VH) and light (VL) chain variable regions. The specificity characteristics and neutralization capacity of phage-displayed and soluble scFv fragments were found to be identical to those of the parental 30AA5 MAb directed against antigenic site II of rabies glycoprotein. Phage-display technology allows the production of new antibody molecule forms able to neutralize the rabies virus specifically. The next step could be to engineer and produce multivalent and multispecific neutralizing antibody fragments. A cocktail of multispecific neutralizing antibodies could contain monovalent, bivalent or tetravalent scFv fragments, for passive immunoglobulin therapy.     

Open air carbon monoxide poisoning

The J = 1-0 to 4-3 spectral lines of SD+3 were measured in the 152-610 GHz region using a source-modulated microwave spectrometer. The SD+3 ion was generated in a free space absorption cell by a hollow-cathode discharge in a gas mixture of D2S and D2. The rotational constant B0 and the centrifugal distortion constants DJ and DJK were determined from the measured frequencies. A vibration-rotation analysis was carried out and the rz structures of SH+3 and SD+3 were derived from their zero point averaged rotational constants, expressed as SH+3: rz = 1.36512(22) ? and thetaz = 94.098(26) degrees, and SD+3: rz = 1.36086(16) ? and thetaz = 94.1211(195) degrees, where the difference between thetaz(HSH) and thetaz(DSD) was assumed to be the same as that between thetaz(HPH) of PH3 and thetaz(DPD) of PD3. From the shift between the rz structures of SH+3 and SD+3, the re structure of SH+3 was estimated to be re = 1.35001(113) ?, thetae = 94.181(135) degrees. Copyright 1998 Academic Press.     

Copper-cerium oxides supported on carbon nanomaterial for preferential oxidation of carbon monoxide

The CuxO-Ce O2/Fe@CNSs, CuxO-Ce O2/MWCNTs-Co and CuxO-Ce O2/MWCNTs-Ni catalysts were prepared by the impregnation method and characterized by transmission electron microscopy, scanning electron microscopy, X-ray powder diffraction, H2-temperature programmed reduction and N2 adsorption-desorption techniques. It was found that the Fe nanoparticles were encapsulated into the multi-layered carbon nanospheres(CNSs). However, the multi-wall carbon nanotubes(MWCNTS) were generated on the Co/Al2O3 and Ni/Al2O3 precursor. The addition of carbon nanomaterial as supports could improve structural properties and low-temperature activity of the Cu O-Ce O2 catalyst, and save the used amount of metal catalysts in the temperature range with high selectivity for CO oxidation. The copper-cerium oxides supported on carbon nanomaterial had good resistence to H2 O and CO2.     

Screening for anisometropia in preschool children

PURPOSE: A preschool vision screening program was reviewed to evaluate eccentric photoscreening (EP), visual acuity, and stereopsis in identifying anisometropia. METHODS: Patients referred by the screening were examined to assess efficacy of the three screening techniques in a population of preschool children. Testability and comparison of screening results to the classification of anisometropia (> or = 1 D) by retinoscopy obtained during a complete examination were evaluated. RESULTS: Although EP identified 94.5% of the anisometropic children as abnormal, only 27.8% were classified as anisometropic by EP. Of the anisometropic children, 36.1% failed acuity, but only 19.4% failed based on a 2 line or greater interocular acuity difference. Stereopsis correctly identified only 7.3% of anisometropes as abnormal. CONCLUSIONS: The sensitivity of EP in identifying anisometropic children as abnormal was superior to acuity and stereopsis, yet its ability to identify anisometropia specifically was poor. Anisometropia of low magnitude or that masked by the dead zone of the EP system was frequently classified as isometropic. Altering the EP referral criterion and/or taking photographs through adequate power plus lenses may improve the sensitivity for specifically identifying anisometropia. However, caution must be exercised when using EP to examine the prevalence of anisometropia in a population or if used to screen for only amblyogenic refractive errors (i.e., anisometropia), because many anisometropes will be missed, resulting in inaccurate prevalence data and significant underreferrals.     

Endogenous carbon monoxide in control of respiration

CASE REPORT: A patient with recurrent breast cancer was reirradiated twice on adjacent fields with a time interval of 9 months. The first time she was treated with reirradiation alone, the second time with reirradiation plus hyperthermia. The reirradiation schedule for both fields was 8 x 4 Gy in 4 weeks. Both fields overlapped partly with the field of postoperative radiotherapy, which was applied 57 and 66 months earlier to a total dose of 40.5 Gy. RESULTS: During the 52 to 61 months follow-up, a remarkable difference in telangiectasia development, between the parts of the reirradiation fields overlapping with the primary radiotherapy field, became apparent. Telangiectasia was observed 9 months after treatment with reirradiation alone and progressed to confluent in 47 months after treatment. In the reirradiation plus hyperthermia area, the maximum observed telangiectasia was slight until 52 months after treatment. DISCUSSION: The difference in the development of telangiectasia between these fields cannot be explained by differences in any of the known radiation treatment related prognostic factors. A protective effect by hyperthermia has been suggested by Haveman and coworkers, who have shown experimentally that heat treatment leads to enhanced proliferation of endothelial cells, thereby inducing a fast repopulation and replacement of X-ray damaged cells. CONCLUSION: This difference in telangiectasia formation is an interesting observation. Whether such a protective effect of hyperthermia is of general relevance has to become clear from more extensive clinical studies.     

Pulse oximetry in severe carbon monoxide poisoning

STUDY OBJECTIVES: To evaluate the accuracy and quantitate the error of pulse oximetry measurements of arterial oxygenation in patients with severe carbon monoxide (CO) poisoning. DESIGN: Retrospective review of patient clinical records. SETTING: Regional referral center for hyperbaric oxygen therapy. PATIENTS: Thirty patients referred for treatment of acute severe CO poisoning who demonstrated carboxyhemoglobin (COHb) levels >25%, with simultaneous determinations of arterial hemoglobin oxygen saturation by pulse oximetry (SpO2) and arterial blood gas (ABG) techniques. MEASUREMENTS AND RESULTS: COHb levels and measurements of arterial oxygenation from pulse oximetry, ABG analysis, and laboratory CO oximetry were compared. SpO2 did not correlate with COHb levels. SpO2 consistently overestimated the fractional arterial oxygen saturation. The difference between arterial hemoglobin oxygen saturation (SaO2) calculated from ABG analysis and SpO2 increased with increasing COHb level. CONCLUSIONS: Presently available pulse oximeters overestimate arterial oxygenation in patients with severe CO poisoning. An elevated COHb level falsely elevates the SaO2 measurements from pulse oximetry, usually by an amount less than the COHb level, confirming a prior observation in an animal model. Accurate assessment of arterial oxygen content in patients with CO poisoning can currently be performed only by analysis of arterial blood with a laboratory CO-oximetry.     

Copper deoxidation kinetics utilizing carbon monoxide

Gaseous deoxidation of liquid copper with carbon monoxide as the reducing gas has been examined. The reducing gas was introduced at a submerged orifice so that well characterized, single bubbles were formed. The deoxidation kinetics are determined primarily by the mass transport of oxygen in liquid copper. No effect of sulfur over the range of 10 to 200 ppm was observed. Increasing the temperature from 1113 to 1173°C slightly inhibit the kinetics of oxygen removal. R. J. ANDREINI and R. B. PHILLIPS, Formerly Graduate Students, Michigan Technological University, Houghton, MI 49931, This paper is based on a portion of the dissertation submitted by R. J. Andreini in partial fulfillment of the requirements for the degree of Doctor of Philosophy at Michigan Technological University.     

Copper deoxidation kinetics utilizing carbon monoxide

Gaseous deoxidation of liquid copper with carbon monoxide as the reducing gas has been examined. The reducing gas was introduced at a submerged orifice so that well characterized, single bubbles were formed. The deoxidation kinetics are determined primarily by the mass transport of oxygen in liquid copper. No effect of sulfur over the range of 10 to 200 ppm was observed. Increasing the temperature from 1113 to 1173°C slightly inhibit the kinetics of oxygen removal. Formerly Graduate Students, Michigan Technological University, Houghton, MI 49931 This paper is based on a portion of the dissertation submitted by R. J. Andreini in partial fulfillment of the requirements for the degree of Doctor of Philosophy at Michigan Technological University.     

Oxytocin release is inhibited by the generation of carbon monoxide from the rat hypothalamus--further evidence for carbon monoxide as a neuromodulator

Recent evidence suggests that the gas nitric oxide can modulate the secretion of a number of hypothalamic hormones, and may be co-localized particularly to oxytocin-containing neurons. Another gas, carbon monoxide (CO), has also been suggested to play a role in neural signaling in the brain, and the synthetic enzyme responsible for the generation of carbon monoxide has been reported to be present in the rat hypothalamus. In this study, we have therefore investigated whether CO has the ability to modify the release of oxytocin from acute rat hypothalamic explants. Hemin, a specific CO precursor through the enzyme heme oxygenase (the enzymatic pathway synthesizing endogenous CO, was found to inhibit KCl-stimulated oxytocin release, with a maximal effect at 10(-5) M, while showing no effect on basal oxytocin secretion. The stimulation of oxytocin by serotonin 10 ng/ml was also significantly antagonized by hemin 10(-7) M. An inhibitor of heme oxygenase, zinc-protoporphyrin-9, had no effect on basal or stimulated oxytocin release. When hemin and zinc-protoporphyrin-9 were given together, the hemin-induced inhibition of oxytocin was completely antagonized by the enzyme inhibitor. Ferrous hemoglobin A0, a substance known to bind CO with high affinity, had no effect on either basal or stimulated oxytocin release, but when hemin and ferrous hemoglobin A0 were given together the hemin-induced inhibition of oxytocin was completely blocked. These findings provide evidence that endogenous CO may play a role in the control of oxytocin release and that, by analogy with nitric oxide, CO may represent a major new neuroendocrine modulator.     

HMPAO brain SPECT in acute carbon monoxide poisoning

Technetium-99m-hexamethylpropylene amine oxime (HMPAO) brain images with fanbeam SPECT, in combination with surface three-dimensional display, were used to detect basal ganglion and cerebral cortex anomalies in the acute phase of carbon monoxide (CO) poisoning. METHODS: Ten patients, aged 16-29 yr, with acute CO poisoning and no past history of neurologic disorders were enrolled in this study. After oxygen treatment, all 10 patients were investigated using 99mTc-HMPAO brain images with fanbeam SPECT and surface three-dimensional display. Meanwhile, 6 of 10 patients also received a brain CT scan. RESULTS: CT scan findings were negative in all 6 patients. Fanbeam SPECT demonstrated unilateral or bilateral hypoactivity of basal ganglia in 6 patients. Local hypoactivity anomalies were found in the brain cortex of 7 patients, using surface three-dimensional display of the brain. Only 2 of 10 patients had normal 99mTc-HMPAO brain images. CONCLUSION: This study suggests that, in comparison with traditional brain imaging techniques, 99mTc-HMPAO brain imaging with fanbeam SPECT in combination with surface three-dimensional display is a better tool for early detection of regional cerebral anomalies in acute CO poisoning.     

Lime-enhanced carbon monoxide reduction of cuprous sulfide

Kinetic studies were conducted on the carbon monoxide reduction of cuprous sulfide powder in the presence of lime as a function of quantity of lime in the charge, CO flowrate, temperature, and time of reduction and particle size of the sulfide. Lime was found to enhance drastically the rate of reduction as well as reduce the COS emission into the off-gas to negligible levels. Both temperature and flowrate of the reducing gas were found to influence the reduction rate, and best results were obtained at 1273 K and at a CO flowrate of 3.33 cm³ s⁻¹. The overall reaction seems to be governed by the intrinsic kinetics of the Cu₂S-CO reaction. Kinetic analysis reveals the observance of the Valensi’s equation, indicating diffusional control through the product layer formed over reacting Cu₂S particles. The calculated experimental activation energy of 169.6 kJ/mole in the termperature range of 1123 to 1273 K is in good agreement with that reported in the literature for sulfur diffusion in copper. A critical comparison has been made of the lime-scavenged reduction of Cu₂S by different reagents, namely, hydrogen, carbon monoxide, and carbon.     

Screening for congenital hypothyroidism in cognitively delayed children

BACKGROUND: Estrogen replacement therapy (ERT) in postmenopausal women decreases cardiac mortality and improves endothelial function. The endothelium regulates vascular tone and growth by releasing such factors as nitric oxide and endothelin-1. OBJECTIVE: To determine whether ERT alters the balance between the total oxidized products of nitric oxide and endothelin-1. DESIGN: Single-arm, before-after clinical trial. SETTING: Outpatient clinical research center of an academic medical center. PATIENTS: 15 postmenopausal women. INTERVENTION: Treatment with 17 beta-estradiol for 6 months and a 10-day course of methoxyprogesterone every 3 months. MEASUREMENTS: Plasma nitric oxide and endothelin-1 levels were measured at baseline and after 6 months of ERT. RESULTS: The mean baseline nitric oxide level was 27.5 nmol/mL (range, 20.3 to 34.8 nmol/mL) and increased by a mean of 7.2 nmol/mL (range, 0.2 to 14.1 nmol/mL) (P = 0.04). The mean baseline plasma endothelin-1 level was 16.4 pg/mL (range, 12.0 to 20.8 pg/mL) and decreased by a mean of 3.9 pg/mL (range, 0.4 to 7.8 pg/mL) (P = 0.04). The mean baseline ratio of nitric oxide to endothelin-1 was 2.0 (range, 1.3 to 2.8) and increased by 1.2 (range, 0.1 to 2.2) (P = 0.03). CONCLUSION: ERT results in an increased ratio of nitric oxide to endothelin-1. This may be one mechanism by which ERT provides cardiovascular benefit.