Carbon dioxide (CO2) poisoning is rare, but its clinical features of acute exposure include cardiovascular, respiratory, neurologic and metabolic aspects. CO2 can also have a direct toxicological effect. At very high concentrations (>9%), CO2 induces respiratory depression and narcotic-like effects on the central nervous system. Especially, acute poisoning from dry ice is caused by CO2 gas inhalation and asphyxiation, and may impose excess load on the myocardium. This case was an acute CO2 poisoning from dry ice gas inhalation. In spite of an initial severe status, the male patient rapidly improved with no complications following the application of highly concentrated oxygen and fluid therapy.
Carbon ; Carbon Dioxide ; Central Nervous System ; Dry Ice ; Fluid Therapy ; Humans ; Inhalation ; Male ; Myocardium ; Oxygen ; Respiratory Insufficiency

Nitric acid is an oxidizing agent used in metal refining and cleaning, electroplating, and other industrial applications. Its accidental spillage generates oxides of nitrogen, including nitric oxide (NO) and nitrogen dioxide (NO2), which cause chemical pneumonitis when inhaled. The clinical presentation of a nitric acid inhalation injury depends on the duration and intensity of exposure. In mild cases, there may be no symptoms during the first few hours after exposure, or the typical symptoms of pulmonary edema can appear within 3-24 hours. However, in cases of prolonged exposure, progressive pulmonary edema develops instantaneously and patients may not survive for more than 24 hours. We report a case of a 44-year-old male who was presented with acute respiratory distress syndrome after nitric acid inhalation. He complained of cough and dyspnea of a sudden onset after inhaling nitric acid fumes at his workplace over a four-hour period. He required endotracheal intubation and mechanical ventilation due to fulminant respiratory failure. He was managed successfully with mechanical ventilation using positive end expiratory pressure and systemic corticosteroids, and recovered fully without any deterioration in his pulmonary function.
Adrenal Cortex Hormones ; Adult ; Cough ; Dyspnea ; Electroplating ; Humans ; Inhalation* ; Intubation, Intratracheal ; Male ; Nitric Acid* ; Nitric Oxide ; Nitrogen ; Nitrogen Dioxide ; Oxides ; Pneumonia ; Positive-Pressure Respiration ; Pulmonary Edema ; Respiration, Artificial ; Respiratory Distress Syndrome, Adult* ; Respiratory Insufficiency

The aim of this study was to compare the compositions and cytotoxicity of white ProRoot MTA (white mineral trioxide aggregate) and 3 kinds of Portland cements. The elements, simple oxides and phase compositions of white MTA (WMTA), gray Portland cement (GPC), white Portland cement (WPC) and fast setting cement (FSC) were measured by inductively coupled plasma atomic emission spectrometry (ICP-AES), X-ray fluorescence spectrometry (XRF) and X-ray diffractometry (XRD). Agar diffusion test was carried out to evaluate the cytotoxicity of WMTA and 3 kinds of Portland cements. The results showed that WMTA and WPC contained far less magnesium (Mg), iron (Fe), manganese (Mn), and zinc (Zn) than GPC and FSC. FSC contained far more aluminum oxide (Al2O3) than WMTA, GPC, and WPC. WMTA, GPC, WPC and FSC were composed of main phases, such as tricalcicium silicate (3CaO.SiO2), dicalcium silicate (2CaO.SiO2), tricalcium aluminate (3CaO.Al2O3), and tetracalcium aluminoferrite (4CaO.Al2O3.Fe2O3). The significance of the differences in cellular response between WMTA, GPC, WPC and FSC was statistically analyzed by Kruskal-Wallis Exact test with Bonferroni's correction. The result showed no statistically significant difference (p > 0.05). WMTA, GPC, WPC and FSC showed similar compositions. However there were notable differences in the content of minor elements, such as aluminum (Al), magnesium, iron, manganese, and zinc. These differences might influence the physical properties of cements.
Agar ; Aluminum ; Aluminum Oxide ; Calcium Compounds ; Diffusion ; Glutamates ; Guanine ; Humans ; Iron ; Magnesium ; Manganese ; Oxides ; Plasma ; Silicates ; Spectrometry, X-Ray Emission ; Spectrum Analysis ; Zinc ; Pemetrexed

The new method is described of extracting various types of cataracts intracapsularly by means of a pencil-shaped metal instrument, named Krwawicz's model cryoextractor. This is refrigerated in a mixture of dry ice and methyl alcohol so that when the ice-coated tip is applied to the lens, the capsule and the underlying cataractous masses adhere firmly to its ball-shaped end and an easy intracapsular extraction is ensured. Fifty extractions of various types of cataracts have been performed by this method. In 49 cases the cataract could be extracted intracapsularly. In only one case did the capsule rupture but it was possible to remove the capsule and lens mass almost completely. The results of the fifty extractions by this method are given.
Cataract Extraction* ; Cataract* ; Dry Ice ; Methanol ; Rupture

OBJECTIVE: To investigate the physical and chemical properties of pulp capping materials based on bioactive glass (BG). METHODS: Novel BG pulp capping materials were composed of powder and fluid. The powder was BG (82.36% SiO₂, 15.36% CaO, and 2.28% P₂O₅) synthesized by using the sol-gel method combined with template technology. Two kinds of fluid were provided: (1) phosphate buffer (PB) solution and (2) phosphate buffer solution with 1% sodium alginate (SA) addition. After mixing the powder and fluid, BG-PB and BG-PB-SA were prepared. Setting time and compressive strength of the BG pulp capping materials were tested by setting time loading system and mechanical testing machine. Statistical analysis was performed using the independent sample t-test, with the significance set at 0.05. pH meters was used to test the pH of the BG pulp capping materials and mineral trioxide aggregate (MTA). The sealing ability of the BG pulp capping materials and MTA was tested by methylene blue dye leakage model. Statistical analysis was performed using one-way ANOVA analysis and LSD multiple comparison, with the significance set at 0.05. RESULTS: (1) Setting time: the initial and final setting time of BG-PB were (7.2±0.3) min and (12.7±0.9) min, respectively. And the initial and final setting time of BG-PB-SA was (7.5±0.3) min and (13.6±1.6) min. There was no significant difference between BG-PB and BG-PB-SA groups (P>0.05). (2) Compressive strength: the compressive strength of BG-PB was (16.5±1.8) MPa at 1 day and (14.1±3.7) MPa at the end of 28 days. However, the compressive strength of BG-PB-SA was (26.6±6.3) MPa on day 1 and (21.6±5.6) MPa on day 28, which was significantly higher than that of BG-PB (P<0.05). (3) pH: the pH of BG pulp capping materials' bulk immersed in simulated body fluid (SBF) went up to 8.06, and the highest pH of MTA was 8.47. Significant difference was observed between the BG pulp capping materials and MTA (P<0.05). (4) Sealing ability: the optical density (D) in positive control group was significantly higher than ln BG-PB, BG-PB-SA and MTA groups (P<0.05). And BG-PB and BG-PB-SA showed the similar favorable sealing ability with MTA, and no significant difference was observed among the three groups (P>0.05). CONCLUSION The novel BG pulp capping materials showed good physical properties, especially BG's setting time was short; BG pulp capping materials are promising.
Aluminum Compounds ; Calcium Compounds ; Compressive Strength ; Dental Pulp Capping ; Glass ; Materials Testing ; Oxides ; Silicates ; Silicon Dioxide

In order to provide bases for the control of air pollutants in Korea, the author figured out the trend on the annual increase of air pollutants emitted in the process of combustions, and estimated the amounts of air pollutants of the future years from 1975 to 1981. 1) In 1973 the consumption rate of coal was 1.2 times of that of fuel oil. The consumption rate of them would be same in 1975 and 1977. However, the rate of fuel oil would exceed that of coal in 1979. In contrast with the rate in 1979. The one of coal would be increased faster and faster to show reverse trend of consumption in 1981. 2) The estimated amounts of air pollutants emissions in the years of 1973, 1975, 1977, 1979 and 1981 were 1,561,800, 1,921,700, 2,253,300, 20769,000, and 3,145,700 tons respectively. These indicated that the amount of air pollutants in 1981 would be about 2 times of that in 1973. 3) The amounts of sulfur oxides emissions in 1981 would be 2.3 times of that in 1973, nitrogen oxides 2.2 times, carbon monoxide 1.7 times, particulate 2.0 times and hydrocarbon 2.0 times. 4) The estimated amounts of air pollutants emissions per unit area(km) in the years of 1965, 1971, 1975 and 1980 were 5.2, 14.5, 19.5 and 28.7 tons respectively. These indicated that the amount of air pollutants emissions per unit area would increase 5.5 times in 1980 comparing the one in 1965.
Air Pollutants ; Carbon Monoxide ; Coal ; Fuel Oils ; Korea* ; Nitrogen Oxides ; Sulfur Oxides

OBJECTIVETo observe the expression of inducible nitric oxide synthase (iNOS) in rat dental pulp after direct pulp capping with calcium hydroxide (CH) and mineral trioxide aggregate (MTA).

METHODSSamples from 42 Wistar rats were immediately collected at 1, 3, 7, 14, 21 and 28 days after direct pulp capping with CH and MTA. Pulp tissues were studided with immunohistochemical stain. Software for image analysis was used to test the optical density of each specimen. The data were analyzed by paired t-test and Dunnett-t test with SPSS 11.5.

RESULTSIn normal pulp, the stain of iNOS was negative. After direct pulp capping with CH or MTA, iNOS expression demonstrated weakly positive, positive, weakly positive, negative at different time, the expression was low immediately after capping but became strong after 3 days. Until 7 days the stain became less positive gradually and at 21 days the stain approached normal. The expression was mainly at the fibroblasts, odontoblasts, vascular endothelial cells, neutrophils, etc near the bottom of the pulp capping agent. The diffence of iNOS expression was significant 3 days after direct pulp capping with this two capping agents.

CONCLUSIONAfter direct pulp capping, iNOS expression increasd at first and then decreased, the diffence of capping agents will have an impact on the expression of iNOS 3 days after direct pulp capping.

Aluminum Compounds ; Animals ; Calcium Compounds ; Calcium Hydroxide ; Dental Pulp ; Dental Pulp Capping ; Drug Combinations ; Nitric Oxide Synthase Type II ; Oxides ; Pulp Capping and Pulpectomy Agents ; Rats ; Rats, Wistar ; Root Canal Therapy ; Silicates

The impurities potentially contained in nitrous oxide cylinders include NO, NO2, CO and NH3. The consequences of inahaling NO and NO2 are reflex breathing inhibition with laryngospasm and the rapid onset of intense cyanosis due to altered pulmonary gas exchange and methaemoglobinemia. Pulmonary edema may occur in the acute stage. Chronic chemical pneumonitis may follow with resultant pulmonary fibrosis and the respiratory and metabolic acidosis may also occur. Hypotension may be marked and results from the effects of nitrate and nitrite ions on vascular smooth muscle. Since certain clinical features provide clues that allow practicing anesthetists to recognize the toxicities of higher nitrogen oxides, six of our cases will be described in detail, whereas the remaining cases will be only commented. We examined a N2O cylinder at the National Metrology Institute, its NOX concentration was 2359 ppm. Another two cylinders were also abnormal with NOX concentrations of 547 ppm and 180 ppm. We recommend that medical gases be subjected to quality control on a national basis.
Acidosis ; Cyanosis ; Gases ; Hypotension ; Ions ; Laryngismus ; Muscle, Smooth, Vascular ; Nitrogen Oxides ; Nitrous Oxide* ; Pneumonia ; Pulmonary Edema ; Pulmonary Fibrosis ; Pulmonary Gas Exchange ; Quality Control ; Reflex ; Respiration

In order to provide some basic data for the control of air water pollution in Korea, the suthors have estimated the amount of air and water pollutant emitted from industries which are employed over 20 employes. This study have done from July 1, 1972 to the end March 1973. The results are as follows: 1. Total number of establishments tith over 20 employees is 5,197 in Korea and the largest gorup establishments was the manufacturing of texttiles with 1,363 establishments(26.2%). 2. By order of number of employees it was observed that there 2,800 industries with 20-59(53.9%) employees, 1,101 with 50-99(21.2%), 571 with 100-199(11.0%), 501 with 200-499(9.6%) and 225with over 500(4.3%) respectively. 3. By order of regional distribution, it was observed that there were 2,257 industries in Seoul (43.3%) and 736 industries in Pusan(14.2%). 4. Industrial coal consumption was 596,154 M/T in 1972, but it'11 be 315,000 M/T in 1980, Fuel consumption was 4,972,000 K1 in 1972, and estimated volume will be 19,3700,000 K1 in 1980. 5. Ttotal amounts of air polutants emitted from industris by fuel combustion were sulfur oxides 79,459 tons, carbon monoxide 33,908 tons, particulate 31,304 tons and hydrocarbon 30,280 tons in 1972 but in 1990 there will be sulfur oxides 1,010,474 tons, nitrogen oxides 204,575 tons, carbon monoxide 68,014 tons, particulate 64,820 tons and hydrocarbon 67,622 tons, respectively. 6. Annual emitted air pollutants through the working processes were sulfur oxides 91,250 tons and nitrogen oxides 32,485 tons in 1972, but sulfur oxieds 118,625 tons and nitrogen oxides 42,555 tons will be present in 1980, respectively. 7. Annual emitted air pollutants by national unit area amounted to 0.77 tons/km2/year in 1965 and 14.7 ton/km2/year in 1980. 8. Total industrial wastes from all industries in Korea were estimated at 810,360 tons/day in 1972; manufacturing of chemicals and plastic products showed the highest amount of wastes at 470,000 tons/day. 9. The amounts of water pollutants due to industrial wastes were the .B.O.D., 471.5 tons/day,suspended solid 331.5 tons/day, CN, 2.3 tons/day, and Cr. 3. 4 tons/day in 1972, but it might be evident of a B.O.D of 3.388 tons/day, suspended solid 2,544 tons/day, CN 20.1 tons/day, and 26.5 tons/day in 1990. 10. Total population equivalent of B.O.D. was 943,000 in 1972, and the estimated value in 1990 will be6, 780, 000.
Air Pollutants ; Carbon Monoxide ; Coal ; Industrial Waste ; Korea* ; Nitrogen Oxides ; Plastics ; Seoul ; Sulfur ; Sulfur Oxides ; Water Pollutants* ; Water Pollution

OBJECTIVES: This study was performed in order to investigate the molecular mechanism regulating nitric oxide synthase(NOS) induced by alpha-quartz in Rat2 fibroblast. METHODS: alpha-quartz-induced nitric oxide(NO) and H2O2 formation and alpha- quartz-induced iNOS protein expression in Rat2 fibroblast were monitored. With iNOS inhibitor(L-N6- (1-iminoethyl)lysine hydrochloride, L-NIL) or antioxidant(catalase), we observed NO and H2O2 formation and iNOS protein expression in Rat2 fibroblast stimulated with alpha-quartz. RESULTS: alpha-quartz stimulated iNOS-induced NO and H2O2 formation in Rat2 fibroblast. L-NIL inhibited H2O2 formation and iNOS protein expression by alpha-quartz in Rat2 fibroblast. Pretreatment with catalase blocked the autoinhibitory pathway of iNOS by iNOSinduced H2O2, therefore H2O2 and NO production and iNOS protein expression were increased in Rat2 fibrobalst stimulated with alpha-quartz CONCLUSIONS: alpha-quartz-induced iNOS stimulated H2O2 formation in Rat2 fibroblast. INOS-induced H2O2 by alpha-quartz plays an important role in the autoinhibition pathway for regulating the iNOS function in Rat2 fibroblast
Catalase ; Fibroblasts* ; Homeostasis* ; Hydrogen Peroxide* ; Hydrogen* ; Nitric Oxide ; Quartz