Screening for carbon monoxide in children

We present the use of risperidone as a potentiation strategy of the serotonergic antidepressants in four patients suffering from refractory obsessive-compulsive disorder. There were an important improvement in three patients. Adding risperidone to serotonergic antidepressants causes complex interactions between serotonergic, dopaminergic and noradrenergic systems, that could lay to the clinical improvement. These and other similar cases make necessary controlled studies. Adding risperidone to serotonergic antidepressants in patients suffering from refractory obsessive-compulsive disorder might be an effective strategy with low risk for secondary effects and without the presence of tics or psychotic symptoms.     

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.     

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.     

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.     

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.     

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.     

Mechanism of the toxic action of carbon monoxide

Our studies indicate that a high concentration of carboxyhemoglobin (COHb) does not interfere with the O2--carrying capacity of the blood. In dogs, both the transfusion of erythrocytes containing 80 percent COHb and the i.p. injection of carbon monoxide (CO) gas do not produce CO toxicity even though the COHb is above 50 percent. Dogs inhaling CO (13 percent in air) for 15 minutes died within 15 minutes to 65 minutes with an average COHb level of 65 percent. The probable toxic action of CO is on the cellular respiration taking place in the mitochondria when CO competes with O2 for cytochrome a3. The presence of dissolved CO in plasma, which is necessary for CO to enter the tissue, probably occurs when the exchange takes place between alveolar air and the blood in the lungs. When air containing CO is inhaled, there will be a significant CO tension in the blood when it leaves the lungs and when it reaches the organs especially the heart and brain. While COHb level is useful as a clinical measure of CO exposure, the most important mechanism by which CO causes toxicity is its combination with cytochrome oxidase.     

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 chlorination kinetics of zirconium dioxide in the presence of carbon and carbon monoxide

Chlorination of zirconium dioxide, an important step in the commercial production of reactor grade zirconium metal, has been studied using carbon and carbon monoxide as reductants. Zirconium tetrachloride was produced when the oxide was reacted with chlorine alone above 1000°C; by introducing carbon the reaction temperatures could be lowered 200°C, and when carbon monoxide was used the reaction temperatures necessary for similar rates were even lower. With carbon monoxide the chlorination of zirconium dioxide is described by two regions differentiated by temperature and the dependence of reaction rate upon chlorine and carbon monoxide pressures.     

职业性急性一氧化碳中毒五例报告

2009年2月2日,宝鸡市某县水泥厂发生5例职业性急性一氧化碳中毒,现报告如下. 1 中毒经过 2009年2月2日上午8时30分宝鸡市某水泥厂生料车间的5名维修工人在生料车间进行焊接加固时,没有采取任何防护措施,稍后有人感觉胸闷、头晕,但未引起重视,9时10分左右,有两人晕倒.随后赶来的工人把5名工人转移到安全地带并迅速送往医院进行抢救.     

Treatment of carbon monoxide poisoning with hyperbaric oxygen

This report describes differences in humoral immune response of acute and chronic phases of human Chagas disease. The reactivities of IgG, IgM, and IgA anti-Trypanosoma cruzi antibodies in serum samples from both groups of patients were compared by enzyme-linked immunosorbent assay (ELISA) employing either one of four antigenic fractions: mouse laminin (LAM), which reacts through Gal alpha 1-3Gal epitopes expressed on trypomastigote surface: whole intact trypomastigotes (TCT); trypomastigotes excreted/secreted antigens (TESA); and epimastigote alkaline extract (EAE). The selection of T. cruzi antigen preparations was based on their relative content of surface and internal antigens found in trypomastigote forms. The proportion of IgG reactive to carbohydrate epitopes was assessed through the decay of IgG reactivity from acute and chronic sera after m-periodate oxidation of solid-phase bound antigens. Trypomastigote and TESA antigens recognized by IgG from acute and chronic sera were also compared by immunoblotting. ELISA and immunoblotting data showed that: (1) the proportion of IgG directed to trypomastigote surface antigens was higher in acute than in chronic sera, whereas the opposite was found for internal antigens, (2) acute sera contained a higher percentage of IgG reactive to trypomastigote carbohydrate epitopes than chronic sera, and (3) anti-T. cruzi IgA was found exclusively in acute sera and led to 100% positivity when LAM, TCT, and TESA were employed as antigens. IgA ELISA with these antigens and IgG immunoblotting pattern with TESA could be useful as serological markers for the acute phase of human Chagas disease.     

Kinetics of manganese ore reduction by carbon monoxide

A step has been made in the direction of understanding the fundamental chemical processes taking place inside electric are furnaces producing manganese alloys. The reduction of higher manganese oxides to MnO by carbon monoxide has been studied in the temperature range 700 °C to 1100 °C. A topochemical pattern with a single shrinking core inside the ore particles has been observed in most cases. It has been found that the reduction of some manganese silicates (braunite minerals) is influenced by reaction interface kinetics, whereas the reduction rate of manganese oxides (bixbyite and hausmannite) is mostly determined by product shell pore diffusion. Sintering kinetics and the extent of natural porosity determine the product shell pore diffusivity. As the melting point of the reaction product is approached, rapid sintering leads to a decrease in diffusivity.