Curcumin-ethyl-cellulose (EC) sustained-release composite particles were prepared by using supercritical CO2 anti-solvent technology. With drug loading and yield of inclusion complex as evaluation indexes, on the basis of single factor tests, orthogonal experimental design was used to optimize the preparation process of curcumin-EC sustained-release composite particles. The experiments such as drug loading, yield, particle size distribution, electron microscope analysis (SEM) , infrared spectrum (IR), differential scanning calorimetry (DSC) and in vitro dissolution were used to analyze the optimal process combination. The orthogonal experimental optimization process conditions were set as follows: crystallization temperature 45 degrees C, crystallization pressure 10 MPa, curcumin concentration 8 g x L(-1), solvent flow rate 0.9 mL x min(-1), and CO2 velocity 4 L x min(-1). Under the optimal conditions, the average drug loading and yield of curcumin-EC sustained-release composite particles were 33.01% and 83.97%, and the average particle size of the particles was 20.632 μm. IR and DSC analysis showed that curcumin might complex with EC. The experiments of in vitro dissolution showed that curcumin-EC composite particles had good sustained-release effect. Curcumin-EC sustained-release composite particles can be prepared by supercritical CO2 anti-solvent technology.
Carbon Dioxide ; chemistry ; Cellulose ; administration & dosage ; analogs & derivatives ; chemistry ; Curcumin ; administration & dosage ; chemistry ; Delayed-Action Preparations ; Solubility ; Solvents ; Technology, Pharmaceutical

OBJECTIVE: The study was aimed to investigate the effects of different levels of pressure and duration of carbon dioxide and saline in the neck of rabbits on metabolic, hemodynamic, serum sodium concentrations and hematocrit changes. METHOD: Twenty-one New Zealand rabbits were randomly divided into 7 groups according to the following pressure of CO2 or saline: 0 kPa, 0.67 kPa CO2, 1.33 kPa CO2, 2.00 kPa CO2, 0.67 kPa saline, 1.33 kPa saline, and 2.00 kPa saline. In order to make a space for the endoscopic thyroidectomy, we filled the neck of rabbits with carbon dioxide and saline. Arterial partial pressure of CO2 (PaCO2), pH, heart rate (HR), mean arterial pressure (MAP), central venous pressure (CVP), serum sodium concentration and hematocrit were measured at baseline, 45 min and 90 min after filling with gas or saline and 30 min post-filling. RESULT: Insufflation of CO2 at 0.67 kPa did not have any significant effect on the parameters, PaCO2 increased significantly 45 min and 90 min after insufflation of 1.33 kPa CO2 (P < 0.01). Marked changes in PaCO2, pH and CVP occurred 45 min and 90 min after insufflation of 2.00 kPa CO2 (P < 0.01), and the parameters did not return to baseline in 30 min after desufflation (P < 0.05). In animals receiving saline irrigation no significant changes occurred in PaCO2, pH and serum sodium concentrations at any time point. There was a tendency of decrease in HCT, but no statistically significant changes were found (P > 0.05). CVP increased significantly 90 min after saline irrigation at 1.33 kPa (P < 0.05). A significant increase in CVP occurred 45 min and 90 min after saline irrigation at 2.00 kPa (P < 0.05). No significant changes in HR and MAP occurred in all animals. CONCLUSION Filling with saline which does not cause hypercapnia, acidosis or dilutional hyponatremia can be used in endoscopic neck surgery to create and maintain a working space.
Animals ; Carbon Dioxide ; administration & dosage ; therapeutic use ; Endoscopy ; Insufflation ; Rabbits ; Sodium Chloride ; administration & dosage ; therapeutic use ; Thyroidectomy ; methods

OBJECTIVETo investigate the influence of CO(2) and He insufflation administered at different pressures on the migration and cytoskeleton of cultured human gastric cancer cells.

METHODSThe cultured gastric cancer cells MKN-45 were exposed to a CO(2) or He environment maintained at different pressures (12, 15 mm Hg). After 0, 2, 4, 6, 8 hours exposure to CO(2) or He environment, pH of the MKN-45 cells culture media was measured with blood gas analysis. The cell migration was detected with Transwell technology. The cell cytoskeleton was observed with laser confocal microscope.

RESULTSThe media pH was acid after exposure to CO(2) environment, while it was basic in the He group. The number of cells passing millipore in 12 mm Hg CO(2) or He insufflation pressure were not significantly different with control group (P>0.05), however in 15 mm Hg pressure CO(2) group, it was significantly decreased as compared to control group (P<0.01). The microfilament and microtubule in gastric cancer cell were ambiguous in 15 mm Hg pressure CO(2) group.

CONCLUSIONSThere are no obvious effects on the migration and cytoskeleton of MKN-45 cells under 12 mm Hg CO(2) insufflation pressure. The migration and cytoskeleton of MKN-45 cells can be inhibited in 15 mm Hg CO(2) pneumoperitoneum environment.

Carbon Dioxide ; administration & dosage ; Cell Line, Tumor ; Cell Movement ; Cell Survival ; Cytoskeleton ; Humans ; Pneumoperitoneum, Artificial ; Pressure ; Stomach Neoplasms ; ultrastructure

There are many factors affecting the successful performance of CT colonography (CTC). Adequate colonic cleansing and distention, the optimal CT technique and interpretation with using the newest CTC software by a trained reader will help ensure high accuracy for lesion detection. Fecal and fluid tagging may improve the diagnostic accuracy and allow for reduced bowel preparation. Automated carbon dioxide insufflation is more efficient and may be safer for colonic distention as compared to manual room air insufflation. CT scanning should use thin collimation of < or =3 mm with a reconstruction interval of < or =1.5 mm and a low radiation dose. There is not any one correct method for the interpretation of CTC; therefore, readers should be well-versed with both the primary 3D and 2D reviews. Polyps detected at CTC should be measured accurately and reported following the "polyp size-based" patient management system. The time-intensive nature of CTC and the limited resources for training radiologists appear to be the major barriers for implementing CTC in Korea.
Carbon Dioxide/administration & dosage ; Cathartics/therapeutic use ; Colonic Polyps/radiography ; Colonography, Computed Tomographic/*methods ; Contrast Media/administration & dosage ; Diagnosis, Computer-Assisted ; Feces ; Humans ; Imaging, Three-Dimensional ; Insufflation/methods

Ibuprofen/ethyl-cellulose (EC)-polyvinylpyrrolidone (PVP) sustained-release composite particles were prepared by using supercritical CO2 anti-solvent technology. With drug loading as the main evaluation index, orthogonal experimental design was used to optimize the preparation process of EC-PVP/ibuprofen composite particles. The experiments such as encapsulation efficiency, particle size distribution, electron microscope analysis, infrared spectrum (IR), differential scanning calorimetry (DSC) and in vitro dissolution were used to analyze the optimal process combination. The orthogonal experimental optimization process conditions were set as follows: crystallization temperature 40 degrees C, crystallization pressure 12 MPa, PVP concentration 4 mgmL(-1), and CO2 velocity 3.5 Lmin(-1). Under the optimal conditions, the drug loading and encapsulation efficiency of ibuprofen/EC-PVP composite particles were 12.14% and 52.21%, and the average particle size of the particles was 27.621 microm. IR and DSC analysis showed that PVP might complex with EC. The experiments of in vitro dissolution showed that ibuprofen/EC-PVP composite particles had good sustained-release effect. Experiment results showed that, ibuprofen/EC-PVP sustained-release composite particles can be prepared by supercritical CO2 anti-solvent technology.
Calorimetry, Differential Scanning ; Carbon Dioxide ; chemistry ; Cellulose ; administration & dosage ; analogs & derivatives ; chemistry ; Crystallization ; Delayed-Action Preparations ; Drug Carriers ; Drug Compounding ; Ibuprofen ; administration & dosage ; chemistry ; Microscopy, Confocal ; Particle Size ; Povidone ; administration & dosage ; chemistry ; Solubility ; Spectrophotometry, Infrared ; Technology, Pharmaceutical ; methods

We investigated the effect of urinary alkalinization accomplished by intraperitoneal injection of sodium bicarbonate and acetazolamide on gentamicin nephrotoxicity in male Fisher 344rats. Forty rats (body weight 200-300g) were divided into four groups: control (gentamicin 20mg/kg, bid), high sodium load (gentamicin 20mg/kg, 25cc of saline, bid), low bicarbonate (gentamicin 20mg/kg, 25cc of sodium bicarbonate 100mEq/L, 2.5mg of Diamox, bid) and high bicarbonate (gentamicin 20mg/kg, 10cc of sodium bicarbonate 250mEq/L, 2.5mg of Diamox, bid) groups. All drugs and electrolyte solutions as mentioned above were administered intraperitoneally twice a day for seven days and changes in renal functions were studied. While salt loading failed to influence the severity of gentamicin nephrotoxicity, urinary alkalinization induced by bicarbonate and acetazolamide injection showed remarkable ameliorating effects on gentamicin nephrotoxicity. The high bicarbonate group exhibited more beneficial effects than the low bicarbonate group on gentamicin nephrotoxicity. So, urinary alkalinization seems to be an effective method for the prevention of gentamicin nephrotoxicity in rats.
Animal ; Bicarbonates/*administration and dosage ; Carbon Dioxide/urine ; Gentamicins/*toxicity ; Kidney Diseases/chemically induced/*prevention and control ; Male ; Random Allocation ; Rats ; Rats, Inbred F344

An investigation of extrapulmonary oxygenation was made in dogs, rabbits and, finally, in a case of Tetralogy of Fallot using an intestinal perfusion of hydrogen peroxide (H2O2). For a single administration, 0.4 per cent H2O2 can be given safely by enema, in doses of 10ml./Kg. of body weight, this would give maximum oxygenation in both the portal vein and inferior vena cava without the formation of gas emboli. Concentrations higher than this caused gas bubbles in the portal vein. For serial administrations, 0.2 per cent H2O2 can be given by enema exchanging the intestinal contents at 10 to 15 minutes intervals. When given concomitantly with human whole blood, 1.0ml./Kg. of body weight, there is a prolonged higher oxygenation in the portal vein, inferior vena cava and femoral artery. This concentation of H2O2 would not cause gas emboli in the portal vein. Although extrapulmonary oxygenation is possible by giving oxygen by enema, this method would cause too much abdominal distension. In experiments of death by suffocation, the group given H2O2 had doubled the duration of E.K.G. activity when compared with controls. One patient with Tetralogy of Fallot, confirmed by clinical findings, X-ray studies, E.K.G. and cardiac catheterization, who was not suitable for cardiac surgery because of low mentality, was selected for this study. 0.2 per cent H2O2, 10ml. per Kg. of body weight by enema, exchanging intestinal contents at 30 minutes intervals, resulted in a marked elevation of the pO2 in the venous blood and in the inferior vena cava. There was a disappearance of finger tip and toe tip cyanosis and flushing of the soles and palms was noted during the procedure.
Acidosis, Respiratory/diagnosis ; Animals ; Asphyxia/therapy ; Carbon Dioxide/blood ; Child ; Dogs ; Enema ; Female ; Hematocrit ; Human ; Hydrogen Peroxide/administration & dosage/*therapeutic use ; Male ; Oxygen/blood ; Tetralogy of Fallot/*therapy

OBJECTIVETo accurately calculate the protein requirements in Chinese young adults using the indicator amino acid oxidation technique.

METHODSNine women and ten men received a restricted daily level of protein intake (0.75, 0.82, 0.89, 0.97, and 1.05 g/kg), along with L-[1-13C]-leucine. Subjects' protein requirement was determined by a biphasic linear regression crossover analysis of F13CO2 data. In doing so, a breakpoint at the minimal rate of appearance of 13CO2 expiration specific to each level of dietary protein was identified. This trial was registered with the Chinese clinical trial registry as ChiCTR-ONC-11001407.

RESULTSThe Estimated Average Requirement (EAR) and the Recommended Nutrient Intake (RNI) of protein for healthy Chinese young adults were determined to be 0.87 and 0.98 g/(kg•d), respectively, based on the indicator amino acid oxidation technique.

CONCLUSIONThe EAR and RNI of mixed protein are 5% and 16% that are lower than the current proposed EAR and RNI (0.92 and 1.16 g/(kg•d), respectively), as determined by the nitrogen balance method. The respective EAR and RNI recommendations of 0.87 and 0.98 g/(kg•d) of mixed protein are estimated to be reasonable and suitable for Chinese young adults.

Adult ; Amino Acids ; metabolism ; Body Composition ; Body Weight ; Breath Tests ; Carbon Dioxide ; analysis ; Dietary Proteins ; administration & dosage ; Female ; Humans ; Male ; Nutritional Requirements ; Oxidation-Reduction ; Young Adult

INTRODUCTIONPulse oximetry (SpO2) measures oxygen saturation but not alveolar ventilation. Its failure to detect alveolar hypoventilation during sedated endoscopy under oxygen supplementation has been reported. The aim of this study was to measure the masking effect of oxygen supplementation in SpO2 when alveolar hypoventilation develops during sedated endoscopy.

METHODSA total of 70 patients undergoing sedated diagnostic colonoscopy were randomly divided into two groups - oxygen supplementation group (n = 35) and room air breathing group (n = 35). SpO2 and end-tidal carbon dioxide (etCO2) were measured by non-intubated capnography during the procedure for all the patients.

RESULTSThe rise of etCO2 caused by alveolar hypoventilation was comparable in the two groups after sedation. SpO2 was significantly higher in the oxygen supplementation group than in the room air breathing group (98.6% ± 1.4% vs. 93.1% ± 2.9%; p < 0.001) at peak etCO2, and oxygen supplementation caused SpO2 to be overestimated by greater than 5% when compared with room air. SpO2 at peak etCO2 was reduced from the baseline before sedation for the oxygen supplementation and room air breathing groups by 0.5% ± 1.1% and 4.1% ± 3.1%, respectively (p < 0.001).

CONCLUSIONSpO2 alone is not adequate for monitoring alveolar ventilation during sedated endoscopy under oxygen supplementation due to possible delays in detecting alveolar hypoventilation in patients. Even if SpO2 decreases by only 1% during the procedure and its level remains near 100%, physicians should consider the onset of severe alveolar hypoventilation, which requires immediate intervention.

Adult ; Aged ; Carbon Dioxide ; analysis ; Colonoscopy ; Conscious Sedation ; Endoscopy ; Female ; Humans ; Hypoventilation ; diagnosis ; Male ; Middle Aged ; Monitoring, Intraoperative ; methods ; Oximetry ; methods ; Oxygen ; administration & dosage ; Respiration, Artificial

The corporeal blood gas changes in accordance with the duration of the prolonged erection which developed after intracorporeal pharmacotherapy with papaverine and phentolamine were investigated in 62 impotence patients. The picture of the corporeal blood taken from 15 psychogenic impotence patients (a control group) at 10 minutes after intracavernous injection when they showed full erections was arterial but there was pCO2 rise and pH drop compared to femoral artery blood taken simultaneously. As the erection lasted longer, significant gas changes of the cavernous blood began to appear (p<0.0001): increase in pCO2 and decrease in pO2 from 4 hours, decrease in pH from 5 hours, decrease in O2 saturation from 6 hours. Erections lasting for more than 16 hours showed significantly worse hypoxia (p<0.05). Therefore, to prevent hypoxia and metabolic acidosis, drug-induced prolonged erection would be better decompressed before it lasts for more than 4 hours.
Adult ; Carbon Dioxide/*blood ; Erectile Dysfunction/*blood/drug therapy ; Femoral Artery ; Humans ; Hydrogen-Ion Concentration ; Male ; Middle Aged ; Oxygen/*blood ; Papaverine/administration & dosage/therapeutic use ; Penile Erection/*drug effects ; Phentolamine/administration & dosage/therapeutic use ; Time Factors