No abstract available.
Osmolar Concentration*

PURPOSE: To evaluate the effect of dry eye on the corneal thickness measured by Orbscan and ultrasonic pachymetry. METHODS: The central corneal thickness was measured by both ultrasonic and Orbscan pachymetry in 30 eyes with dry eye (dry eye group) and in 30 eyes of normal subjects (control group). Dry eye was diagnosed when a Schirmer test result was less than 10 mm (after topical anesthesia) and the test for tear osmolarity was also performed. RESULTS: Tear osmolarity was 364.4+/-42.9 mOsm/L in dry eye group and 337.8+/-34.5 mOsm/L in control group. It was significantly higher in dry eye group than in the control group (p=0.011). Mean central corneal thickness measured by Orbscan pachymetry was 547.5+/-27.3 microgram in dry eye group and 562.0+/-20.4 microgram in the control group. It was significantly thinner in dry eye group than in the control group (p=0.023). Mean central corneal thickness measured by ultrasonic pachymetry was 535.7+/-27.2 microgram in dry eye group and 547.6+/-20.1 microgram in the control group with out significant difference between the two groups (p=0.059). CONCLUSIONS: The corneal thickness measured by ultrasonic pachymetry is less affected by dry eye compared to that measured by Orbscan pachymetry.
Osmolar Concentration ; Ultrasonics*

The osmotic pressure of ammonium sulfate solutions has been measured by the well-established freezing point osmometry in dilute solutions and we recently reported air humidity osmometry in a much wider range of concentration. Air humidity osmometry cross-validated the theoretical calculations of osmotic pressure based on the Pitzer model at high concentrations by two one-sided test (TOST) of equivalence with multiple testing corrections, where no other experimental method could serve as a reference for comparison. Although more strict equivalence criteria were established between the measurements of freezing point osmometry and the calculations based on the Pitzer model at low concentration, air humidity osmometry is the only currently available osmometry applicable to high concentration, serves as an economic addition to standard osmometry.
Ammonium Sulfate ; chemistry ; Freezing ; Humidity ; Osmolar Concentration ; Osmometry ; methods ; Osmotic Pressure ; Solutions

156 patients with chronic renal failure and 40 medical students with normal health were studied. Early - Morning urine osmolality and urine 24h osmolality were measured. The authors concluded; Early-Morning urine osmolality related with renal concentration function better than urine sample 24h osmolality.
Kidney Failure ; Urination ; Osmolar Concentration

One of the purposes of this experiment is to observe the structure of crystalline lens with cataract, which is formed artificially, using the light microscope and electron microscope. The other is to observe the differences of structural variations in the cataract developed inside body. Twelve eyes of six pigs were used for this experiment. Two of them are normal crystalline lens, five are cystalline lens in distilled water, and the rest are in balanced salt solution through intact or ruptured capsule. We examined the time of cataract formation and compared the ultrastructural changes. Ruptured capsule and high osmotic pressure difference induced more rapid opacity. In case of distilled water, the capsule is maintained but it is very difficult to distinguish between epithelium and lens fibers. Also, there is a severe crack in the lens fibers. In electron microscopic, as the cataract progresses, the osmotic swelling becomes more prominent. One of the striking changes was a marked intercellular cyst formation. Lens cells became irregular in size and density and were extensively vacuolated. The swelling of the lens cells continuously induced large intracellular vacuoles and liquefied the cytoplasmic protein. In conclusion, the structural change of cataract, which was seen by an electron microscope, resulted from change in osmolarity from previously announced in vivo experiment and structural change resulted from this experiment are similar.
Cataract* ; Crystallins* ; Cytoplasm ; Epithelium ; Lens, Crystalline* ; Microscopy, Electron ; Osmolar Concentration ; Osmotic Pressure ; Strikes, Employee ; Swine ; Vacuoles ; Water

PURPOSE: Cryopreserved stem cells from cord blood are usually infused with Dimethyl Sulfoxide (DMSO) immediately after thawing. However, this process may cause cell damage due to osmotic shock, and the administration of DMSO may also cause toxic effects. We studied a new method of increasing cell viability by stabilizing osmolarity by adding dextran 40 and washing out DMSO. METHODS: Thirty-five samples of cord blood were studied. RBCs were removed in 10% pentastarch. The cells were mixed with DMSO of 5, 10 and 20% each, and stored at -80 degree C. Cryopreserved cells were thawed and then diluted with dextran 40. DMSO was removed afterwards. The cell viability, osmolarity and colony forming capacity in this new thawing method were compared with the control group done by conventional methods. RESULTS: The recovery rate of WBC after RBCs separation was 92.06% but the contamination rate of RBC was still high(29.90%). The concentration of DMSO significantly affected the survival of WBCs(P<0.05). The osmolarity was 330+/-17.7mOsm/L before freezing, 1,457+/-508.7mOsm/L after thawing prior to dilution and 811+/-199.6mOsm/L after dilution, suggesting that the dilution process was effective in reducing osmolarity. The number of viable cells increased from 6.01+/-1.61(x103/L) to 7.16+/-1.48(x103/L) after dilution but was not significant. The number of CFU-C was increased from 5.82+/-4.19(/105) to 7.58+/-3.16(/105) after dilution but was not significant. CONCLUSION: Our method of removing DMSO during the thawing process yields a higher cell survival rate and less DMSO toxicities compared with the conventional method of direct injection with DMSO after thawing.
Cell Survival* ; Dextrans ; Dimethyl Sulfoxide* ; Fetal Blood ; Freezing ; Hydroxyethyl Starch Derivatives ; Osmolar Concentration ; Osmotic Pressure ; Stem Cells*

In a series of 91 patients underwent stereotaxic evacuation of spontaneous intraparenchymal hematoma during last 2 years; 15 had simple aspiration and 76 had urokinase irrigation gradually through the indwelling silastic catheter. Dosage of used urokinase was average 26,000u and duration was average 2.8 days. The average removed volume percent of the hematoma was 80.1+/-15.2%, eight out of 76 cases were performed urokinase irrigation revealed rebleeding; causes were overpressure during aspiration in 4 cases, blood dyscrasia in 3 cases, and fibrinolytic effect of urokinase in one case. High incidence of rebleeding were; thalamus(4 out of 16 cases; 25%) in location, before 6 hours(4 out of 19 cases; 21.1%) in operation time interval from ictus, below 10ml(4 out of 13 cases; 30.8%) in volume of the hematoma, but not correlated with amount of used urokinase. Causes of unsatisfactory removed cases were small hematoma, brain stem and thalamic hemorrhage and malposition of the catheter. Even in cases of combined ventricular hemorrhage, we didn't experienced hydrocephalus with urokinase irrigation. In 20 cases sampled randomly, osmolality of serum and aspirated liquefied hematoma were compared; the serum osmolality was 297.6+/-12mEq and osmolality of liquefied hematoma induced by urokinase was 304.7+/-11.3mEq. These findings strongly suggest that the surrounding interstitial fluid of the hematoma was shifted into the liquefied hematoma because of 7mEq difference of osmotic pressure. Over all good result(daily living activity) on discharge was 64.5% and mortality rate was 7.9%.
Brain Stem ; Catheters ; Extracellular Fluid ; Hematoma* ; Hemorrhage ; Humans ; Hydrocephalus ; Incidence ; Mortality ; Osmolar Concentration ; Osmotic Pressure ; Urokinase-Type Plasminogen Activator

Osmotic diuretics are used in neurosurgical patient to decrease intracranial pressure. Mannitol produces diuresis because it is filtered by the glomeruli and not reabsorbed from the renal tubule, leading to increased osmolarity of renal tubular fluid and associated excretion of water. There are some controversies about the effect of mannitol induced diuresis on the change of serum electrolytes. But these controversies are related to the mannitol dosage and infusion speed. We studied the effect of mannitol on serum and urine e1ectrolyte change in 10 patients undergoing operation of cerebral tumor or aneurysm. Every patient was free from cardiac and renal disease. We started infusion of 20% mannitol of which dosage is 0.6-0.9gm/kg for 5 to 10 min after cranium was opened and then injected furosemide O.l mg/kg for acceleration of diuresis. We measured serum electrolyte, urine volume and urine electrolyte before and after 30, 60 and 120 min of mannitol infusion. The results were as follows. 1) Seurm sodium and chloride level decreased significantly from 133 and 102 to l30 and 100 mEq/1 respectively after 30 min, but there was no statistic significance after 60 and 120 min of mannitol infusion. 2) Serum potassium level increased slightly from 4.2 to 4.5 mEq/1 after mannitol infusion but there was no statistic significance. 3) Urine volume increased abruptly from 57 to 477 ml/hr as soon as infusion of mannitol but the degree decreased slowly following times. 4) Urine electrolytes concentration increased abruptly as soon as infusion of mannitol but the degree decrease slowly following times. With the above results, we can conclude that intraoperative mannitol and furosemide infusion in healthy patient can cause only transient change in serum electrolyte and the magnitude of change was too small to have significant clinical effect.
Acceleration ; Aneurysm ; Diuresis ; Diuretics, Osmotic ; Electrolytes ; Furosemide ; Humans ; Intracranial Pressure ; Mannitol* ; Neurosurgery ; Osmolar Concentration ; Potassium ; Skull ; Sodium

99 patients aged 15 – 87 years old were hospitalized at Bach Mai Hospital from June 1998 to Feb.2003, among them 51 cases were diagnosed as sufferring from diabetes and in 48 other, diabetes were still not diagnosed. At admission, average blood level of glucose 18,97+/_8,1 mmol. In 35-50% of studied cases, plasma osmolarity >300 mOsmol/kg H2O during monitored time. There was no statistically significant difference between various groups in the variation of glucose plasma level .In 10-20% of cases, there was an increase of 145 mmol/l of natrium in plasma
Hyperglycemia ; Osmolar Concentration ; Plasma ; Electrolytes ; Emergencies

No abstract available.
Humans ; Infant, Newborn* ; Osmolar Concentration* ; Specific Gravity*