Ketamine Affects the Expression of ErbB4 in the Hippocampus and Prefrontal Cortex of Rats.

Schizophrenia is a severe chronic neuropsychiatric disorder, and its exact pathogenesis remains unclear. This study investigated the effect of ketamine on the expression of ErbB4 (considered a schizophrenia candidate gene) in the hippocampus and prefrontal cortex of rats. Rats were randomly divided into four groups: control, low-dose, medium-dose and high-dose groups. The low-dose, medium-dose and high-dose groups were intraperitoneally injected with 15 mg/kg, 30 mg/kg and 60 mg/kg ketamine, respectively, twice a day (9:00 a.m. and 9:00 p.m.); the control group was administered normal saline. The treatment lasted 7 days. After treatment, rats were euthanized, and their brain tissues were collected and then analyzed by immunohistochemistry. The results of immunohistochemistry staining demonstrated that the ErbB4 protein was expressed exclusively in the CA3 region of the hippocampus and the Cg1 region of the prefrontal cortex. Ketamine administration significantly decreased the expression of ErbB4 in a dose-dependent manner. The high-dose ketamine treatment was found to be optimal for establishing a rat model for schizophrenia. Ketamine induced symptoms similar to schizophrenia in humans. The ketamine-induced rat model for schizophrenia constructed in this study provides novel insights to better understand the pathogenic mechanisms of schizophrenia and aid in drug discovery.

mTOR Expression in Hippocampus and Prefrontal Cortex Is Downregulated in a Rat Model of Schizophrenia Induced by Chronic Administration of Ketamine.

Schizophrenia is a severe chronic neuropsychiatric disorder, and it negatively affects individuals' quality of life, but the pathogenesis of schizophrenia remains unclear. This study aimed to explore whether the administration of ketamine in rats causes changes in mTOR (mechanistic/mammalian target of rapamycin) expression in the hippocampus and prefrontal cortex. Ketamine was used to establish an animal model of schizophrenia. Rats were randomly divided into four groups: control group (normal saline), low-dose group (15 mg/kg ketamine), middle-dose group (30 mg/kg ketamine), and high-dose group (60 mg/kg ketamine). The rats were intraperitoneally injected with ketamine or normal saline twice a day (9 AM and 9 PM) for 7 consecutive days. Immunohistochemistry was used to detect mTOR protein expression in the hippocampus and prefrontal cortex from rats at 13 h after the last treatment. Using immunohistochemistry, the expression of the mTOR protein was localized exclusively in the CA3 region of the hippocampus and in the Cg1 region of the prefrontal cortexes. Ketamine at 60 mg/kg decreased the expression of mTOR protein in the brain of rats. Ketamine successfully established a rat model of schizophrenia. This study helps elucidate the mechanisms of ketamine-induced schizophrenia and provides novel insights for drug discovery and development.

Non-Fire Related Carbon Monoxide Poisoning in Sichuan, China: A 9-Year Study (2008-2016).

BACKGROUND: Carbon monoxide (CO) poisoning is one of the most important intoxications in the modern world. This study aimed to identify the characteristics of CO poisoning deaths in Sichuan province in the west of China. METHODS: Data on fatal non-fire-related carbon monoxide poisoning in Sichuan from 2008 to 2016 were obtained from the Department of Forensic Analytical Toxicology of Sichuan University and were analyzed by the month and year of registration of death, sex, age group, manner of death, source of CO, and location of CO exposure. Comparing with the previous studies carried out in Wuhan and Shanghai to identify the regional differences of CO poisoning in China. RESULTS: A total of 165 non-fire related CO poisoning cases including 237 victims were recorded. Over 90% of the victims died from accidental poisoning. Non-fire related CO poisoning occurred more frequently in winter months and was most prevalent in individuals aged between 18 and 60 yr old. Showering gas accident and coal or charcoal burning was found to be the major source of CO in accident and in suicide cases, respectively. Furthermore, significant regional differences of CO poisoning have been detected in the manner of death and the source of CO. CONCLUSION: These findings will be valuable in the targeted prevention of non-fire related CO poisoning in China.

Polymorphism study of nine SNPs associated with subjective response to alcohol in Chinese Han, Hui, Tibetan, Mongolian and Uygur populations.

Heavy alcohol drinking is a major public health problem, causing a large disease, social and economic burden in societies. Subjective response (SR) to alcohol is an intermediate characteristic of heavy drinking. A variety of candidate genes have been reported to be associated with SR to alcohol. In this study, we investigated nine single nucleotide polymorphisms (SNPs) related to SR to alcohol in healthy individuals from five Chinese ethnic groups, the Han, Hui, Tibetan, Mongolian and Uygur populations, and a total of 584 bloodstain samples were collected. The nine SNPs included four SNPs in alcohol-metabolizing genes (ADH1B, ADH1C, ALDH2 and CYP2E1*5B) and five SNPs in genes of neurobiological pathways (GABRA2, OPRM1, CHRNA3, HYKK and SLC6A4). A SNaPshot analysis method was developed to type these SNPs simultaneously, and all samples were typed successfully. Statistical analyses of the allele frequencies indicated that the frequencies of all SNPs, except for ADH1C, showed varying degrees of difference in the five studied ethnic groups. Tibetans showed the highest frequencies of risk alleles for heavy drinking at most loci. The genetic polymorphic differences found in this study revealed the variation in genetic susceptibility to heavy drinking in the studied populations.

Estimation of early postmortem interval in rats by GC-MS-based metabolomics.

Accurately predicting the early postmortem interval (PMI) is of great significance in forensic practice. This study aimed to establish a novel method for estimating the early PMI by analyzing endogenous substances in the cardiac blood of male and female rats and compare different model for estimating early PMI using these data. Adult Sprague-Dawley (SD) rats (50% male) were sacrificed by suffocation. Then, cardiac blood was collected at various time intervals (0, 3, 6, 12, 24, 48, and 72 h) after death, and the collected samples were analyzed by gas chromatography-tandem mass spectrometry (GC-MS). The data were analyzed by multivariate statistical analysis. An orthogonal signal correction-partial least squares (OSC-PLS) regression model was constructed with whole endogenous metabolites to validate the PMI. The OSC-PLS regression model successfully predicted the PMI of the forecast set and no significant differences was observed between male and female rats. This is the first study to establish an OSC-PLS regression model for predicting PMI with the metabolome, which provides a new technical method and platform for estimating PMI through metabolomics.

Urinary metabonomics of rats with ketamine-induced cystitis using GC-MS spectroscopy.

Ketamine abuse has dramatically increased in recently years. With the widely application of ketamine, its side effects, especially cystitis induced by long-term use, have attracted more and more attention from the public. In the present study, we aimed to explore the potential generative mechanism of ketamine-induced cystitis by determining the endogenous metabolites at different time points after ketamine treatment. Body weight, bladder/body coefficient, urinary frequency, urinary potassium, serum IL-6, and TNF-α were determined at different time points after ketamine treatment. H&E staining was used to observe the changes of histopathology. Metabonomics was performed to determine the changes of endogenous metabolites. After 12 weeks of treatment, obvious inflammatory reaction was noticed in the KET group; the body weight and urinary potassium of the KET group were significantly lower than the NS group (P < 0.05) and other factors, such as urinary frequency, bladder/body coefficient, serum TNF-α and IL-6 were higher than the NS group (P < 0.05). A total of 30, 28, and 32 significantly changed metabolites were identified at the 1st week, 4th week and 12th week, respectively. Metabolic pathway analysis showed that different metabolic pathways were affected during the treatment process. Linoleic acid metabolism, beta-alanine metabolism, glyoxylate and dicarboxylate metabolism were only affected following long-term administration of ketamine. Those metabolic pathways may have a close relationship with cystitis induced by ketamine.

Epitaxial Growth of Multimetallic Pd@PtM (M = Ni, Rh, Ru) Core-Shell Nanoplates Realized by in Situ-Produced CO from Interfacial Catalytic Reactions.

Pt-based multimetallic core-shell nanoplates have received great attention as advanced catalysts, but the synthesis is still challenging. Here we report the synthesis of multimetallic Pd@PtM (M = Ni, Rh, Ru) nanoplates including Pd@Pt nanoplates, in which Pt or Pt alloy shells with controlled thickness epitaxially grow on plate-like Pd seeds. The key to achieve high-quality Pt-based multimetallic nanoplates is in situ generation of CO through interfacial catalytic reactions associated with Pd nanoplates and benzyl alcohol. In addition, the accurate control in a trace amount of CO is also of great importance for conformal growth of multimetallic core-shell nanoplates. The Pd@PtNi nanoplates exhibit substantially improved activity and stability for methanol oxidation reaction (MOR) compared to the Pd@Pt nanoplates and commercial Pt catalysts due to the advantages arising from plate-like, core-shell, and alloy structures.

Homicidal Poisoning in China Using Several Anesthetic Drugs.

The authors describe a case of a well-designed homicidal poisoning in China. A male was treated with starvation, intravenous fluids and antibiotics while in the hospital for acute diarrhea. He suddenly suffered from shortness of breath and subsequently died. A forensic autopsy was carried out, and several specimens were collected for toxicological screening. Propofol was tentatively identified in the blood by GC-MS. Based on the presence of propofol in the blood, a suspect confessed that two other drugs, namely midazolam and vecuronium, were involved in this murder. Analytical drug quantification was then performed by GC-MS and LC-MS/MS. Blood analysis revealed the following: propofol at 0.5 µg/mL, midazolam at 0.098 µg/mL, and vecuronium at 0.10 µg/mL. These results suggest that the cause of death was respiratory depression due to the acute combined effect of several anesthetic drugs administered by the victim's companion.

Effects of gender on ketamine-induced conditioned placed preference and urine metabonomics.

OBJECTIVE: The aim of this study was to examine whether or not there was a gender difference in CPP (conditioned placed preference) induced by ketamine and to further explore the effect of sex on metabolic responses to ketamine inducing in SD rats. METHODS: We measured ketamine-induced conditioned place preference and ketamine-induced metabolic changes in urine by using (1)H nuclear magnetic resonance (NMR) coupled with principal component analysis (PCA), partial least squares (PLS) and orthogonal signal correction (OSC) analysis. RESULTS: In the CPP experiment, ketamine served as a positive reinforcing agent in both male and female rats, but, in particularly, the preference score of female rats was significantly higher than that of male rats. Compared with male rats, the metabolic trajectory fluctuation of the female rats was relatively larger. At the same time, different metabolites (1, 3-dimethyluric acid, cysteine-S-sulfate, glyceraldehydes, glycine, ribitol, acetoacetic acid, creatine, 3-methyladenine, hypotaurine, taurine, dimethylglycine and theobromine) between male and female rats were found. CONCLUSIONS: Female Sprague-Dawley rats were more sensitive to the ketamine-induced CPP than male rats. The fluctuation ranges of metabolic trajectory and metabolite contents in urine were both different between female and male rats. This would provide targeted suggestions for ketamine abuser, for example, men and women should take different drug withdrawal therapeutic methods.

[Relationship among ALDH2 gene polymorphism, alcohol metabolism and acetaldehyde level in peripheral blood].

OBJECTIVE: To explore alcohol pharmacokinetics as well as acetaldehyde level in peripheral blood in human subjects with different ALDH2 genotypes after drinking. METHODS: Venous blood samples of 14 unrelated volunteers were collected. Polymerase chain reaction-restriction fragment length polymorphism technology was adopted for DNA extraction and ALDH2 genotyping. The volunteers were asked to drink beer at certain doses. The concentration of alcohol and acetaldehyde were assayed by headspace gas chromatography method at different time. The pharmacokinetic parameters were calculated. RESULTS: According to the results of electrophoresis, 5 people carried ALDH2*1/*1 as wild group and 9 people carried ALDH2*1/*2 as mutation group. The good linear range of alcohol and acetaldehyde were 0-1 570.7 microg/mL and 0-5.1772 microg/mL, respectively. The AUC values of alcohol and acetaldehyde and the t1/2Z value of alcohol were higher in the mutation group than that in the wild group. But the CL/F value of alcohol was lower in the mutation group than that in the wild group (P<0.05). CONCLUSION: After the consumption of alcohol, alcohol and acetaldehyde metabolism in blood slow down in ALDH2*1/*2 mutation group influenced by the inhibition of enzyme activity, leading to the accumulation of acetaldehyde in peripheral blood, thus reinforcing their effects in the body.

[Reversal effect and its mechanism of (- )-5-N-acetylardeemin on adriamycin resistance in multidrug-resistant cancer cells A549/Adr and MCF-7/Adr].

OBJECTIVE: To explore the reversal effect of (- )-5-N-acetylardeemin on adriamycin resistance in multidrug-resistant cancer cells including human breast cancer cells MCF-7/Adr and human non-small cell lung cancer cells A549/Adr in vitro. METHODS: The multidrug-resistant cancer cells MCF-7/Adr, A549/Adr and their respective parental cells were treated with different concentrations of (- )-5-N-acetylardeemin and adriamycin individually or in combination. Cell death was detected based on the release of lactate dehydrogenase (LDH) using a cytotoxicity detection kit. Intracellular accumulation of adriamycin was measured by the detection of fluorescence intensity of cell lysates using microplate reader. The expression of P-glycoprotein (P-gp) was evaluated by Western blot. RESULTS: (-)-5-N-acetylardeemin significantly reversed the adriamycin resistance in MCF-7/Adr and A549/ Adr in a dose-dependent manner, and the reversal folds were 10. 8 in MCF-7/Adr cells and 20.1 in A549/Adr cells with the treatment of 10 µmol/L (-)-5-N acetylardeemin. (- )-5-N-acetylardeemin also enhanced the sensitivity of parental MCF-7 and A549 cells to adriamycin. The fluorescence intensity in both MCF-7/Adr and A549/Adr cells, which reflected the intracellular accumulation of adriamycin, were significantly enhanced by ( -)5-N- acetylardeemin in a dose-dependent manner. The expressions of P-gp in MCF-7/Adr and A549/Adr cells were significantly inhibited by (- )-5-N-acetylardeemin. CONCLUSION: (- )5-N-acetylardeemin could reverse the multidrug resistance in cancer cells through inhibiting the expression of P-gp and enhancing the intracellular accumulation of cytotoxic drug.

[Determination of cinobufagin and resibufogenin in liver tissue by HPLC-MS/MS].

OBJECTIVE: To develop a sensitive and accurate assay for detecting cinobufagin and resibufogenin in liver tissue using high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). METHODS: The homogenization of liver tissue with internal standard dexamethasone was extracted with dichloromethane. The extracts with methanol were purified through ProElut C18 solid phase extraction and tested in positive electrospray ionization with multiple reaction monitoring of HPLC-MS/MS. RESULTS: The good linear relationship of cinobufagin and resibufogenin in liver tissue were 1-204 ng/g and 1-206 ng/g, respectively. The minimal detection threshold (S/N > or = 3) of this method was 0.3 ng/g for both cinobufagin and resibufogenin. The matrix effect was 96.5%-126.7%. The extraction recovery coefficient was 70.0%-82.3%. The precision of intra-day and inter-day was less than 10%. CONCLUSION: This method is sensitive and reliable, and can be used in forensic toxicological analysis.

[Determination of unknown impurities in cefotiam hexetil by HPLC-MS/MS].

OBJECTIVE: To detect unknown impurities in raw drug material of cefotiam hexetil. METHODS: High performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) was employed for the determination of impurities in cefotiam hexetil. Agilent SB-C18 column (150 mm x 2.1 mm i. d. , 3.5 microm particles) was used for chromatographic separations of cofotiam hexetil dissolved in deionized water, with mobile phase consisting of (A) 0.1% formic acid and (B) acetonitrile and timed gradient program T (min)/B (%): 0/3, 5/3, 15/20, 20/40, 30/60, 40/80. The flow rate was set at 0. 3 mL/min with DAD detector wavelength fixed at 254 nm. Electrospray ionization source was applied and operated in positive ion MRM mode. The source voltage was kept at 4 kV and cone voltage was 100 V with the mass range m/z 50-1000. Nitrogen was used as nebulizing gas and the nebulizer pressure was 40 psi. The drying gas temperature was 350 degrees C and the drying gas flow was 10 L/min. Results Unknown impurities of cefotiam hexetil were identified. Substance 1 was delta3-isomer of cefotiam hexetil. The structures of 3 other substances were also determined. CONCLUSION: The method is sensitive, rapid and credible for the analysis of cefotiam hexetil and its related impurities, which can be applied in quality control of cefotiam hexetil.

Autocrine TNF-α-mediated NF-κB activation is a determinant for evasion of CD40-induced cytotoxicity in cancer cells.

Activation of CD40 by CD40L results in diverse effects on different malignant cells, causing either promotion of survival, growth and resistance to chemotherapy, or induction of cytostasis and apoptosis. The molecular mechanisms underlying CD40-mediated growth regulation and apoptosis induction in cancer cell are not fully understood. In this study, we investigated the role of NF-κB activation in CD40-mediated cytotoxicity in cancer cells. The results show that activation of CD40 by recombinant soluble CD40 ligand (rsCD40L) readily induced NF-κB activation and blocking NF-κB significantly enhanced rsCD40L-induced apoptosis in cancer cells. Importantly, autocrine of TNF-α induced by rsCD40L was indispensable for both NF-κB activation and cytotoxicity induction, establishing a dual role of autocrine TNF-α that constitutes both pro-apoptotic and anti-apoptotic arms of CD40 signaling. Our results indicate that autocrine TNF-α-mediated NF-κB activation is a determinant for cancer cells' evasion of CD40L-induced cytotoxicity and blocking NF-κB may have potential for improve the value of CD40 as an anticancer agent.

[Recombinant soluble CD40 ligand enhances Wogonin-induced antitumor activity].

OBJECTIVE: To investigate the effect of recombinant soluble CD40 ligand (rsCD40L) on Wogonin mediated antitumor activity in cancer cells and the underlying molecular mechanisms. METHODS: Cell death was detected based on the release of lactate dehydrogenase (LDH) using a cytotoxicity detection kit. For morphological study of cell death, cells were stained with 50 microg/mL of acridine orange and 50 microg/mL of ethidium bromide and observed and photographed under a fluorescence microscope. Activation of apoptosis pathway was evaluated by Western blot. The effects of pan-caspase inhibitor Z-VAD-FMK and tumor necrosis factor alpha (TNF-alpha) neutralizing antibody on cell death induced by rsCD40L and Wogonin co-treatment were also investigated. RESULTS: rsCD40L significantly enhanced Wogonin-induced cell death of ovarian cancer cells SKOV3. A dose-dependent synergism was found with a fixed rsCD40L dose (1 microg/mL) and increased concentrations of Wogonin (5 micromol/L-15 micromol/L). rsCD40L and Wogonin co-treated cells showed typical apoptotic morphologies and enhanced activation of caspases pathway. As expected, the pan-caspase inhibitor Z-VAD-FMK inhibited synergistic cell death of rsCD40L and Wogonin co-treated SKOV3 cells. Interestingly, the TNF-alpha neutralizing antibody that blocks TNF-alpha binding to its receptor also significantly suppressed the cell death enhancing effect, indicating that autocrine TNF-alpha played a role of sensitization. CONCLUSION: rscCD40L sensitizes cancer cells to wogonin-mediated apoptosis, which may involve autocrine of TNF-alpha, and the combination of rsCD40L and Wogonin may have a potential for cancer therapy.

[LC-MS/MS analysis of determination of strychnine and brucine in formaldehyde fixed tissue].

OBJECTIVE: To establish a method for determination of strychnine and brucine in formaldehyde fixed tissue by LC-MS/MS analysis. METHODS: The samples were pretreated with solid phase extraction using SCX cartridges and separated on SB-C18 column with mobile phase 0.1% formic acid : 0.1% formic acid-acetonitrile (75:25). Electrospray ionization (ESI) source was utilized and operated in positive ion mode. Multiple reactions monitoring (MRM) mode was applied. External standard method was applied for quantitation. RESULTS: The chromatographic separation of strychnine and brucine in formaldehyde fixed nephritic and hepatic tissues resulted successfully. The standard curve was linear in the range of 0.002-2.0 microg/g for strychnine and brucine in formaldehyde fixed tissues, and the correlation coefficient was more than 0.996. The limits of detection (LOD) of strychnine and brucine in nephritic tissues were 0.06ng/g and 0.03 ng/g, respectively. The LOD of both chemicals were 0.3 ng/g in hepatic tissues. The extraction recovery rate was more than 74.5%. The precision of intra-day and inter-day were both less than 8.2%. CONCLUSION: Strychnine and brucine can be sensitive to be determined in formaldehyde fixed tissue by LC-MS/MS analysis. It can be applied in the forensic toxicological analysis.

[Effect of heat shock protein 90 inhibitor 17-dimethylamino-ethylaminogeldanamycin on TNfalpha-mediated apoptosis and TNF-induced NF-kappaB activation].

OBJECTIVE: To investigate the effect of heat shock protein 90 (HSP90) inhibitor 17-dimethylaminoethylaminogeldanamycin (17DMAG) on tumor necrosis factor alpha (TNFalpha) mediated apopotosis in cancer cells and the underlying molecular mechanisms. METHODS: Cell death treated with different concentration of 17DMAG and TNFalpha was detected based on the release of lactate dehydrogenase (LDH) using a cytotoxicity detection kit. For morphological study of cell death, cells were stained with 50 microg/mL of acridine orange and 50 microg/mL of ethidium bromide and observed and photographed under a fluorescence microscope. Activation of apoptosis and NF-kappaB pathway were evaluated on the change of caspase-8, caspase-3, poly (ADP-ribose) polymerase (PARP), receptor-interaction protein (RIP), IkappaB kinase beta (IKKbeta) and inhibitor of IkappaB (IkappaBalpha) by Western blot. RESULTS: 17DMAG sensitized cervical cancer cells HeLa and ovarian cancer cells SKOV3 to TNFalpha-induced cell death in a dose-dependent manner, which was accompanied with degradation of RIP and Ikappakappabeta, and consequent blockage of TNFalpha-induced NFkappaB activation. 17DMAG and TNFalpha cotreated cells showed typical apoptotic morphologies and enhancing of activation of caspases. CONCLUSION: 17DMAG sensitizes cancer cells to TNFalpha-mediated apoptosis through blockage of TNF-induced NF-kappaB activation, and disabling this survival signal with 17DMAG followed by TNF treatment could be an effective new therapeutic strategy for improving the anti-cancer value of TNFalpha.

Determination of adenosine phosphates in rat gastrocnemius at various postmortem intervals using high performance liquid chromatography.

Although the change in adenosine phosphate levels in muscles may contribute to the development of rigor mortis, the relationship between their levels and the onset and development of rigor mortis has not been well elucidated. In the current study, levels of the adenosine phosphates including adenosine triphosphate (ATP), adenosine diphosphate (ADP), and adenosine monophosphate (AMP) in gastrocnemius at various postmortem intervals of 180 rats from different death modes were detected by high performance liquid chromatography. The results showed that the levels of ATP and ADP significantly decreased along with the postmortem period of rats from different death mode whereas the AMP level remained the same. In addition, it was found that changes in the ATP levels in muscles after death correlated well with the development of rigor mortis. Therefore, the ATP level could serve as a reference parameter for the deduction of rigor mortis in forensic science.

Absence of association between CD86 +1057G/A polymorphism and coronary artery disease.

CD86, one of the key costimulatory molecules, is not only involved in the initiation of T-cell immunity but also plays important roles in the development of cardiovascular diseases. The purpose of this study was to investigate the association between the CD86 polymorphism and the risk of coronary artery disease (CAD) in a Chinese population. We analyzed single-nucleotide polymorphism of CD86 +1057G/A (rs1129055) in 164 patients with CAD and 299 healthy controls by performing polymerase chain reaction-restriction fragment length polymorphism and DNA sequencing assay. No significant association was observed in the genotype and allele frequencies of +1057G/A polymorphism between cases and controls, indicating that CD86 +1057G/A polymorphism may not be associated with CAD in the Chinese population.

[Analysis of multiple cephalosporins in blood and urine by HPLC].

OBJECTIVE: To establish a new high performance liquid chromatography (HPLC) method for determining the concentration of cefazolin, cefradine, cefoperazone and cefotaxime in blood and urine, as well as to investigate its applicability. METHODS: Protein in blood and urine was precipitated directly by acetonitrile with acetanilide was used as the internal standard using Agilent Zorbax SB-Aq column (250 mm x 4.6 mm, 5 microm). The mixed solvents of water (triethylamine 0.12%, acetic acid 0.12%) and acetonitrile were used as the mobile phase to separate cephalosporins using gradient elution method at 1 mL/min (flow rate) and 254 nm (detection wavelength). RESULTS: The working curve of four cephalosporins showed a good correlation (r = 0.9993), with the detection limit up to 0.01 microg/mL. The recovery rate was more than 81.2%. CONCLUSION: This method is fast, easy and accurate. It is suitable for biological analysis of the 4 cephalosporins of the blood and urine in practical cases.