PURPOSE: Seizure and syncope are main causes of patient visits to an emergency department (ED). However, differentiating two diseases through history taking and several ancillary tests is difficult in an ED. Some reports have claimed that ammonia or lactate could differentiate between seizure and other medical diseases. Therefore, this study evaluated the ability of ammonia and lactate to differentiate seizure and syncope. METHODS: We reviewed the medical records of 388 patients who visited an ED with seizure or syncope. There were 271 patients in the seizure group (69.8%) and 117 patients in the syncope group (30.2%). Ammonia and lactate levels were compared between the two groups. The optimal level of ammonia and lactate, and their sensitivity and specificity, were evaluated to determine their ability to differentiate seizure and syncope. RESULTS: There were more male in seizure group (66%), but the average age was higher in the syncope group (51+/-21 yrs) (p<0.05). The time interval from symptom to ED was similar between the two groups (seizure group: 213+/-803 min and syncope group: 184+/-512 min, p=0.724). The mean ammonia level in the seizure group was higher than the syncope group (85+/-86 microg/dl and 49+/-29 microg/dl, respectively, p<0.001). The mean lactate level was also higher in the seizure group than the syncope group (3.5+/-2.9 mmol/L and 1.6+/-1.5 mmol/L, respectively, p<0.05). When the cutoff value for ammonia was 50 microg/dL [Area under curve (AUC): 0.617, 95% CI: 0.556-0.678] the sensitivity was 61% and the specificity was 52%. When the cut-off value for lactate was 2 mmol/L [AUC: 0.745, 95% CI: 0.692-0.798] the sensitivity was 60% and the specificity was 76%. CONCLUSION: Serum ammonia or lactate may serve as an ancillary method for differentiating seizure and syncope, but their sole application is unacceptable due to their low sensitivity and specificity.
Ammonia* ; Emergencies ; Humans ; Lactates ; Lactic Acid* ; Male ; Medical Records ; Methods ; Seizures* ; Sensitivity and Specificity ; Syncope*

Severe hypoglycemia induces neuroglycopenic symptoms, including mental alteration, as glucose is the exclusive fuel for the central nervous system. However, some reports have shown that non-glucose fuels, like lactates and ketones, could be utilized by the brain during severe hypoglycemia. Herein, a case of extreme hypoglycemia in a 44-year old woman, subsequently diagnosed as congestive heart failure accompanied by ischemic hepatitis and lactic acidosis, is presented. In two episodes of extreme hypoglycemia, she was fully alert without obvious neurological deficits. In this unusual case, an increased supply of lactate might have maintained the cerebral function and prevented cerebral injury during the hypoglycemia that was induced as a result of starvation and hepatic and cardiac dysfunctions
Acidosis, Lactic* ; Adult ; Brain ; Central Nervous System ; Female ; Glucose ; Heart Failure ; Hepatitis ; Humans ; Hypoglycemia* ; Ketones ; Lactates ; Lactic Acid ; Masks* ; Starvation

Severe hypoglycemia induces neuroglycopenic symptoms, including mental alteration, as glucose is the exclusive fuel for the central nervous system. However, some reports have shown that non-glucose fuels, like lactates and ketones, could be utilized by the brain during severe hypoglycemia. Herein, a case of extreme hypoglycemia in a 44-year old woman, subsequently diagnosed as congestive heart failure accompanied by ischemic hepatitis and lactic acidosis, is presented. In two episodes of extreme hypoglycemia, she was fully alert without obvious neurological deficits. In this unusual case, an increased supply of lactate might have maintained the cerebral function and prevented cerebral injury during the hypoglycemia that was induced as a result of starvation and hepatic and cardiac dysfunctions
Acidosis, Lactic* ; Adult ; Brain ; Central Nervous System ; Female ; Glucose ; Heart Failure ; Hepatitis ; Humans ; Hypoglycemia* ; Ketones ; Lactates ; Lactic Acid ; Masks* ; Starvation

OBJECTIVETo investigate the biocompatibility of new bone tissue engineering scaffolds, A:D, L-polylactic acid (PDLLA)/polylactic acid-polyethylene glycol-polylactic acid-polylactic acid (PLA-PEG-PLA)/Tricalcium phosphate and B: PDLLA/PLA-PEG-PLA in vivo, compared with PDLLA in repair of a rabbit mandibular body defect.

METHODS24 New Zealand adult rabbits were divided into 4 groups randomly. 15 mm x 6 mm defects were made surgically in the bilateral mandibular bodies and each hemi-mandible was assigned as an experimental unit. The defects were randomly repaired with scaffold materials in each group. Specimens obtained were evaluated with general observation, X-ray, histomorphology and computerized graphical analysis at 2, 4 , 8, 12 weeks after surgery.

RESULTSCompared with PDLLA, the new scaffold materials B showed biocompatibility. At the same time the quantity of new bone produced was much more than that in control group (P<0.05). The new scaffold materials A showed the clear chronic granulomatous inflammation.

CONCLUSIONNew scaffold material B had sound biocompatibility. It was much better than PDLLA. So it may be an ideal bone tissue engineering scaffold material. A is not adapted to be used as scaffold material.

Animals ; Biocompatible Materials ; Bone and Bones ; Calcium Phosphates ; Lactates ; Lactic Acid ; Polyesters ; Polyethylene Glycols ; Polymers ; Rabbits ; Tissue Engineering ; Tissue Scaffolds

pH and temperature sensitive biodegradable block copolymers are some macromolecules connected by biodegradable materials and pH sensitive monomers according to a certain sequence, or biodegradable polyesters polymerized themselves. On the basis of pertinent documents, the development of pH and temperature sensitive biodegradable block copolymers was introduced, involving their mechanism of action and potential application. PH and temperature sensitive biodegradable block copolymers could control the drug release rate freely, avoiding burst effect. Besides, the biocompatibility of these biodegradable materials is also excellent. So the use of pH and temperature sensitive biodegradable block copolymers as biodegradable drug delivery devices has attracted considerable interest in the intelligent drug delivery system.
Biocompatible Materials ; chemistry ; Drug Delivery Systems ; Hydrogen-Ion Concentration ; Lactates ; chemistry ; Lactic Acid ; chemistry ; Polyesters ; chemistry ; Polyethylene Glycols ; chemistry ; Polyglactin 910 ; chemistry ; Polyglycolic Acid ; chemistry ; Polymers ; chemistry ; Temperature

A new technique was developed to fabricate PDLLA and PDLLA/PELA composite scaffolds by thermally induced phase separation in combination, with particulate-leaching. Effects of PDLLA/PELA ratio, PEG/PLA ratio and PEG molecular weight on properties of mechanics, degradation behavior and cell toxicity as well as morphological properties were investigated. As the result showed, by thermally induced phase separation/ particulate-leaching, a unique morphology that macropores (100-250 microm) and micropores (5-40 microm)coexisted in the scaffold was obtained. An increase of PEG content or a decrease of PEG molecular weight raised the porosity of the scaffold. A decrease of PDLLA/PELA ratio or an increase of PEG/PLA ratio weakened mechanical properties and accelerated the degradation of the scaffold. PDLLA and PDLLA/PELA scaffolds didn't show cell toxicity. When PDLLA/PELA ratio was 3:1 and PEG5000/PLA ratio was 25:75, the scaffold got a regular, highly interconnected, macro-co-micro porous structure.
Biocompatible Materials ; chemistry ; Lactates ; chemistry ; Lactic Acid ; chemistry ; Polyesters ; Polyethylene Glycols ; chemistry ; Polyglycolic Acid ; chemistry ; Polymers ; chemistry ; Porosity ; Surface Properties ; Tissue Engineering ; methods ; Tissue Scaffolds ; chemistry ; Water ; chemistry

Ethylglucoside lactate, a novel Alpha-Hydroxy Acids Derivative, was synthesized by transesterification in non-aqueous phase using immobilized lipase as biocatalyst. Based on the studies of the factors effecting initial rate and conversion under atmospheric pressure (solvent, acyl donor, different immobilized lipase, substrate concentration, enzyme concentration and temperature), the results show that solvent-free medium using butyllactate as acyl donor is suitable to the ester synthesis. The reaction conditions have been optimized as the following: the amount of enzyme = 75 g/L, the ethylglucoside concentration = 0.4 mol/L, 70 degrees C, 200 r/min, 50 h, which the conversion was 71%. A 90% conversion and a 60.7 mmol.L-1.h-1 initial rate can be obtained under reduced pressure, which the conditions are enzyme 75 g/L, ethylglucoside 0.35 mol/L, 65 degrees C, 200 r/min and 40 h. The product purified by extraction and SIO2 chromatography was identified by infrared spectroscopy and 1H NMR.
Candida ; enzymology ; Enzymes, Immobilized ; metabolism ; Esters ; metabolism ; Glucosides ; isolation & purification ; metabolism ; Kinetics ; Lactates ; isolation & purification ; metabolism ; Lactic Acid ; metabolism ; Lipase ; metabolism ; Substrate Specificity ; Temperature

PURPOSE: This study was performed to compare clinical significance between lactate and carboxyhemoglobin (COHb) in a patient with carbon monoxide (CO) poisoning. METHODS: We conducted a 13-year retrospective study on CO poisoning patients who visited the emergency departments of the Medical Center between October 2004 and January 2016. The patients were divided into two groups according to initial lactate levels. Patients with serum lactate levels of ≤2 mmol/L were classified as the normolactatemia group (n=14), and patients with serum lactate levels of >2 mmol/L were classified as the hyperlactatemia group (n=34). General characteristics, clinical features, and laboratory findings of the two groups were compared. In addition, we compared initial lactate levels with COHb levels according to complications, neurological disorder, myocardial enzyme elevation, and abnormal Glasgow Coma Scale (GCS) score in patients with CO poisoning. We also analyzed the correlation between laboratory parameters and lactate levels. RESULTS: Forty-eight patients were enrolled in this study. The hyperlactatemia group had significantly more neurological disorders and consciousness disorders than the normolactatemia group (p<0.001), and COHb, creatine phosphokinase MB, and troponin I levels were also significantly higher in the hyperlactatemia group (p<0.001, p=0.017, and p=0.007). Lactate levels were significantly elevated in patients with elevated cardiac enzymes (p=0.001), neurological disorders (p<0.001), complications (p=0.001), and abnormal GCS score (p<0.001), whereas COHb levels were not significantly increased in all subjects. The correlation between COHb and lactate levels was weak (r=0.313, p=0.030), and a positive correlation was found between lactate and bicarbonate (HCO3), white blood cell, and troponin I (p<0.001). The diagnostic value of lactate for severe CO poisoning was analyzed using a receiver operating characteristic curve. The optimal cut-off value of lactate was 2.2 mmol/L with 83.3% sensitivity and 91.7% specificity (p<0.001). CONCLUSION: Lactate has significant diagnostic efficacy in patients with CO poisoning. It is recommended that lactate level be measured for appropriate treatment and prognostic evaluation of CO poisoning.
Carbon Monoxide Poisoning* ; Carbon Monoxide* ; Carbon* ; Carboxyhemoglobin* ; Consciousness Disorders ; Creatine Kinase ; Emergency Service, Hospital ; Glasgow Coma Scale ; Humans ; Hyperlactatemia ; Lactates ; Lactic Acid* ; Leukocytes ; Nervous System Diseases ; Poisoning ; Retrospective Studies ; ROC Curve ; Sensitivity and Specificity ; Troponin I

PURPOSE: Leigh syndrome is a kind of mitochondrial disease with a pathological production of lactate and variable clinical manifestations. Recently biochemical assay of the mitochondrial enzyme activity and MRS are becoming a powerful tool for the definitive antemorterm diagnosis of this disease. The aim of this study was designed to determine the usefulness of biochemical enzyme assay and MRS in Leigh syndrome. METHODS: A clinical study of 8 cases of pediatric patients were diagnosed as Leigh syndrome on the basis of clinical manifestations and MRI features at the department of pediatrics, Ulsan university hospital, from July, 1992 to June, 1997. Biochemical enzyme assay of the cultured skin fibroblasts was consulted to hospital for sick children, Toronto, Canada. Cerebral lactates were detected on MRS were analysed in relation to the MRI findings and lactate levels in the CSF. RESULTS: 1) Age at diagnosis ranged from 7 months to 8.9 years; seven were boys and one was girl. 2) Main clinical symptoms were as follows in the order of frequency; seizure(75%), ophthalmoplegia(50%), hemiplegia(50%), hypotonia(50%), respiratory difficulty(50%), developmental delay(38%), consciousness change(38%), mental retardation( 25%). 3) Anatomical locations of the focal lesions detected on the initial MRI were as follows in the order of frequency; putamen(75%), caudate nuclei(63%), medulla oblongata (18,50%), substantia nigra(38%), thalamus(38%). 4) Biochemical enzyme assay revealed deficiency of NADH cytochrome c reductase (complex I) and deficiency of cytochrome c oxidase(complex N) respectively in 2 patients who had markedly elevated serum and CSF lactate levels and lactate/pyruvate ratio. 5) Cerebral lactates were detected by MRS from 6 lesions of 1 week-4 months old in 6 patients who had normal or mildly elevated serum and CSF lactate levels and lactate/pyruvate ratio. CONCLUSION: MRS detected the brain parenchymal lactate non-invasively from the acute or subacute lesions. Therefore, combined evaluation by MRS and biochemical enzyme assay will provide an important information for the diagnosis and estimation of disease activity in pediatric patients who are suspected to have Leigh syndrome.
Brain ; Canada ; Child ; Consciousness ; Cytochromes c ; Diagnosis ; Enzyme Assays* ; Female ; Fibroblasts ; Humans ; Lactates ; Lactic Acid ; Leigh Disease* ; Magnetic Resonance Imaging ; Medulla Oblongata ; Mitochondrial Diseases ; NADH Dehydrogenase ; Pediatrics ; Skin ; Ulsan

To study the rheological properties of sucrose acetate isobutyrate (SAIB) in situ gel and the influencing factors. Measurements of shear stress and viscosity were carried out at different shear rate. The rheological properties of SAIB solution were similar to those of Newtonian fluid. The factors such as the type of solvent, concentration, additive, drug and temperature had effect on the rheological properties. Ethanol was a suitable solvent compared with ethyl lactate and N-methylpyrrolidone (NMP). The solution viscosity of SAIB was reduced from 1.29 to 0.11 Pa x s with only increasing the content of ethanol from 10% to 20%. Polylactic acid (PLA) and risperidone could increase the intermolecular force and viscosity. However, adding 10% (w/w) PLA, the initial release of risperidone was reduced from 20.2% to 3.5%. The solution viscosity reduced significantly by stepping up the temperature. The results obtained support the using of SAIB is satisfactorily injectable in situ gel formulation.
Antipsychotic Agents ; administration & dosage ; Delayed-Action Preparations ; Drug Carriers ; Ethanol ; Lactates ; Lactic Acid ; Polyesters ; Polymers ; Pyrrolidinones ; Rheology ; Risperidone ; administration & dosage ; Solvents ; Sucrose ; administration & dosage ; analogs & derivatives ; chemistry ; Temperature ; Viscosity