Studies on resistance of Schistosoma to praziquantel XVIII Sensitivity to praziquantel in filial generations of praziquantel-resistant and -sensitive Schistosoma japonicum mixed infections / 中国血吸虫病防治杂志

Objective To investigate the sensitivity of adult worms of filial generations from praziquantel-resistant and -sensitive Schistosoma japonicum mixed infections to praziquantel. Methods Mice were infected with the cercariae of an experimentally generated praziquantel-resistant S. japonicum isolate [median effective dose (ED50) = 277.4 mg/kg] and a laboratory-maintained praziquantel-sensitive S. japonicum isolate (ED50 = 99.6 mg/kg) at a mixture ratio of 1:1 and 2:1, which was maintained in the laboratory via the mouse-snail cycle for 8 generations. Then, mice were infected with the cercariae of the 8th filial-generation parasite, and grouped 35 days post-infection. Mice in the 5 treatment groups were given praziquantel treatment by gavage at a single oral dose of 37.5, 75, 150, 300 mg/kg and 600 mg/kg, while animals in the control group was administered orally with 2.5% cremophor EL. All mice were sacrificed 14 days post-treatment and adult worms were collected by perfusion of the portal vein. The worm burden reductions and praziquantel ED50 values were calculated. The praziquantel-resistant S. japonicum isolate generated from experimental induction with 12 rounds of praziquantel treatment with sub-curative doses was maintained in the laboratory via the mouse-snail cycle, and mice were infected with the cercariae of the 8th filial-generation parasite. The praziquantel ED50 value against the 8th filial-generation adults was measured. Results After mice were infected with the mixture of cercariae of PZQ-resistant and -sensitive S. japonicum isolates at a ratio of 1:1, the praziquantel ED50 was 135.2 mg/kg against the adults of the 8th filial-generation parasite. After mice were infected with the mixture of cercariae of PZQ-resistant and -sensitive S. japonicum isolates at a ratio of 2:1, the praziquantel ED50 was 129.2 mg/kg against the adults of the 8th filial-generation parasite. In addition, the praziquantel ED50 was 208.4 mg/kg against the adults of the 8th filial-generation S. japonicum without the selection pressure of praziquantel. Conclusions Compared with the experimentally induced praziquantel-resistant S. japonicum isolate, the adult worms of the filial-generation S. japonicum show a reduced sensitivity to praziquantel in the same host following infection with the mixture of cercariae of praziquantel-resistant and -sensitive S. japonicum isolates. The adult worms of the filial generation of the praziquantel-resistant S. japonicum isolate without the selection pressure of praziquantel may still maintain the resistance to praziquantel.

Neutralization of anti-venom IgY against main activities of Deinagkistrodon acutus venom / 中国药理学通报

Aim To evaluate the potency of anti-D. acutus venom IgY neutralizing the main activities of D. acutus venom.Methods After mixing the different a-mounts of IgY with snake venom and incubating togeth-er,the main activities of snake venom were assayed by biochemical methods.Results The in vitro assays in-dicated that anti-D.acutus venom IgY obviously neu-tralized the activities of PLA2 ,5′-nucleotidase,hyalu-ronidase,metalloprotease and serine proteinase (fi-brinogenase)in D.acutus venom.Mouse experiments showed that the ED50 value of IgY for mouse was 1 131.09 μg.Conclusion Anti-D.acutus venom IgY antibodies have good effects in neutralizing D.acutus venom without the toxicities themselves.

The ED50 of dexmedetomidine for suppressing cardiovascular responses to placement of laryngeal mask in female patients with induction of propofol / 实用医学杂志

Objective To determine the ED50 of dexmedetomidine for suppressing cardiovascular responses to placement of laryngeal mask airway (LMA) in patients undergoing gynecological laparoscopic surgery with induction of propofol. Methods ASA I or II Patients aged 18 to 55 undergoing elective gynecological laparoscopic surgery were enrolled. After an bolus dose of dexmedetomidine over 10 min , anaesthesia was induced with target-controled propofol, and then bolus of vecuronium of 0.1 mg/kg was injected when the BIS was between 45 and 55. LM palcement was performed 3 minutes after vecuronium injection. The modified Dixon ’ s up-and-down method was used to determine the bolus dose of dexmedetomidine , starting from 1.0 μg/kg (step size:0.1 μg/kg). Cardiovascular response was defined as an increase in SBP and/or HR by 15% of baseline within 2 min after placement of LMA. The test ended after at least 7 crossovers ( successive ‘response’ or ‘non-response’) were obtained. Probit analysis was used to calculate ED50, ED95 and 95% confidence interval (CI). Results The ED50 and ED95 (95% confidence interval) of dexmedetomidine for suppressing cardiovascular responses to placement of LMA was 0.65 μg/kg (0.44-0.80) μg/kg and 0.94 μg/kg (0.79-2.47) μg/kg. Conclusion Under induction of target-controled propofol , the ED50 of dexmedetomidine is 0.65 μg/kg for suppressing cardiovascular responses to placement of LMA in female patients.

Minimum effective local anesthetic dose of intrathecal ropivacaine for arthroscopic meniscectomy / 重庆医学

Objective To determine the minimum effective local anesthetic dose (ED50 ) of spinal ropivacaine for arthroscopic meniscecto-my .Methods Twenty-five patients undergoing arthroscopic meniscectomy under combined spinal-epidural anesthesia received intrathecal ropivacaine .ED50 of ropivacaine was determined by the sequence method .The effective criteria were as follows :the level of sensory block reaching at least T12 within 20 min after injection of the local anesthetic ;the motion block reaching the Bromage Scale score ≥2 within 20 min after injection of the local anesthetic ;no supplemental epidural anesthetic at least 1 h after injection of the local anesthetic .The initial dose was 15mg and according to the effective or ineffective results in previous patient ,a dose of ropivacaine 1 mg was decreased or increased . Results ED50 of ropivacaine for the arthroscopic meniscectomy was 12 .24 mg(95% CI 12 .09-12 .39) .Conclusion The dose of ropiva-caine more than 12 .24 mg for arthroscopic meniscectomy is the best .But the anesthetic effect may be related with the specific gravity of the local anesthetic and the patients′factors(height ,weight ,age) .

Drug resistance induction and analysis of differential expression protein on adult Schistosoma j aponicum induced by ED50 PZQ / 中国人兽共患病学报

ABSTRACT:In the present study ,we aimed to identify differentially expressed proteins between induced worms (the infec‐ted mice were treated intragastrically with ED50 PZQ) and uninduced worms (control group) for clarifying the mechanism of PZQ .ED50 PZQ was used to administrate mice that were infected with S .japonicum via intragastric incubation for consecutive‐ly 30 days .Twenty‐one days later ,mice were sacrificed after treatment with 200 mg/kg PZQ for continuously five days ,and the male worms were obtained and some of them were subjected in DMEM medium with different concentrations of PZQ in vitro for 16 hours .Then the worms were washed twice and incubated in PZQ‐free medium for 72 hours .Compared with control group ,the induced worms had lesser sensitivity to PZQ .The survival rate of induced worms was 75 .6% in vitro when the con‐centration of PZQ was 112 mol/L (the concentration was 8 times of uninduced worms Lethal Concentration ) ,significantly higher than that in the uninduced worms (11 .1% ,P<0 .05) ,showing obviously tolerance .The other induced and uninduced worms were acquired and collected for 2D‐DIGE and MALDI‐TOF‐MS ,and combined with bioinformatics to analyse the func‐tion of the identified protein .Thirty differential expression proteins were confirmed between induced and uninduced worms ,in‐cluding 12 proteins up‐regulated and 18 proteins down‐regulated .These proteins respectively ascribed to cytoskeleton‐associat‐ed protein ,glucose and energy metabolism enzymes ,stress proteins ,thioredoxin peroxidase enzymes ,and other protease .Up‐or down‐regulation of these differential proteins indicated that PZQ promote or inhibit the expression of some specific genes . These findings may help to clarify the mechanism of PZQ ,simultaneously ,providing a scientific basis for exploring new vaccine candidate antigens and targets for drug therapy .

Efeito da toxicidade de Cr (VI) e Zn (II) no crescimento do fungo filamentoso Aspergillus niger isolado de efluente industrial / Toxicity effect of Cr (VI) and Zn (II) on growth of filamentous fungi Aspergillus niger isolated from industrial effluent

Processos convencionais de tratamento de efluentes utilizam microrganismos vivos, o que sugere limitações relativas À toxicidade de metais para os microrganismos. O experimento consistiu em adicionar soluções monoelementares de Cr (VI) e Zn(II) em diferentes concentrações (0, 20, 50, 100, 200, 300, 400, 500 mg.L-1) ao meio de crescimento e observar a influência dos metais no crescimento micelial e germinativo do fungo Aspergillus Níger por verificação visual da expansão radial do micélio e da germinação de esporos, seguida de registro fotográfico. Os resultados mostraram que o metabolismo do fungo foi completamente inibido em concentrações acima de 500 mg Zn (II).L-1 e 150 mg Cr (VI).L-1. O ED50 (concentração de ingrediente ativo capaz de inibir 50 por cento do crescimento micelial do fungo) para os dois íons metálicos, nas condições estudadas, está na faixa entre 100 e 150 mg.L-1. Palavras-chave: metais pesados; inibição; crescimento micelial; Aspergillus niger; ED50.

Many standard processes of wastewater treatment use live microorganisms, which suggests limitations on a metal toxicity to the microorganism. The experiment consisted in adding mono elementary solutions of Cr (VI) and Zn (II) at different concentrations (0, 20, 50, 100, 200, 300, 400, 500 mg.L-1) to the growth mean, and to observe the influence of metals on mycelial and germinative growth of the Aspergillus niger fungus, by means of visual observation of the radial expansion of the mycelius and the germination of spores, followed by photograph registration. The results showed that the metabolism of the fungus was completely inhibited at concentrations above 500 mg Zn (II).L-1 and 150 mg Cr (VI).L-1. The ED50 (concentration of active ingredient capable of inhibiting 50 percent of mycelial growth of the fungus) for both metal ions, under the studied conditions, is in the range between 100 and 150 mg.L-1.

Miltefosine-Induced Apoptotic Cell Death on Leishmania major and L. tropica Strains

The aim of this study was to assess the cytotoxic effects of various concentrations of miltefosine on Leishmania major (MRHO/IR/75/ER) and L. tropica (MHOM/IR/02/Mash10) promastigotes and to observe the programmed cell death features. The colorimetric MTT assay was used to find L. major and L. tropica viability and the obtained results were expressed as 50% inhibitory concentration (IC50). Also, 50% effective doses (ED50) for L. major and L. tropica amastigotes were also determined. Annexin-V FLUOS staining was performed to study the cell death properties of miltefosine using FACS analysis. Qualitative analysis of the total genomic DNA fragmentation was performed by agarose gel electrophoresis. Furthermore, to observe changes in cell morphology, promastigotes were examined using light microscopy. In both strains of L. major and L. tropica, miltefosine induced dose-dependent death with features of apoptosis, including cell shrinkage, DNA laddering, and externalization of phosphatidylserine. The IC50 was achieved at 22 microM and 11 microM for L. major and L. tropica after 48 hr of incubation, respectively. ED50 of L. major and L. tropica amastigotes were 5.7 microM and 4.2 microM, respectively. Our results indicate that miltefosine induces apoptosis of the causative agent of cutaneous leishmaniasis in a dose-dependent manner. Interestingly, L. major did not display any apoptotic changes when it was exposed to miltefosine in concentrations sufficient to kill L. tropica.

Difference of neuromuscular blocking effect of cis-atracurium under sevoflurane anesthesia between the genders / 中国基层医药

Objective To investigate the difference of neuromuscular blocking effect of cis-atracurium under sevoflurane anesthesia between the genders. Methods 30 ASA Ⅰ or Ⅱ patients aged from 18 to 45 years who scheduled for laparoscopic operation were divided into two groups, male group( M group, n = 15 ) and female group ( F group,n = 15). After induction of Anesthesia all cases were maintained with remifentanyl 3μg/L(TCI) and sevoflurane.After 40 minutes of stable end-tidal anaesthetic concentration, a total dose of cisatracurium 45 μg/kg was divided into 3 equal doses( 15μ g/kg each) ,which was administered accumulatively in each patient. The next dose was given when the effect of the previous dose had reached its peak ( T1 was no longer depressed in the height of 3 successive stimuli).Neuromuscular block was monitored using accelograph(TOF GUARD,Denmark). The onset time and maximum depression of T1 of the initial dose and 2 incremental doses were recorded. The cumulative dose-response curves of the two groups were established. The effective dose to obtain 50% and 95% neuromuscular block( ED5o and ED95 ,respectively) were calculated from individual dose-response curves. After the lastincrement of 15 μg/kg, the time for T1 to return to 25% ,50% ,75% and TOF ratio(T4/T1 )to 70% were recorded. The recovery index( RI)was also calculated.Results The mean ED5o and ED95(95% confidence interval)of cisatracurium of women were 22.2( 15.8 ～27.2)and 38.4 ( 32.1 ～ 54.4) μg/kg during sevoflurane (1.3MAC) anaesthesia, while the data of men were 25.6 ( 19.7 ～30.8) μg/kg and 42.8 ( 36.3 ～ 58.2 ) μg/kg, the difference between groups had no statistical significance ( P ＞0. 05). There was no significant difference in the TOF ratio ( T4/T1 ) to 70% and recovery index between the two groups( P ＞0.05 ). The onset time of F group was shorter than M group. The time for T1 to return to 25% ,50% and TOFR 0.7 was significantly longer in the F group than in the M group (P ＜ 0.05). Conclusion The neuromuscular blocking effect of cis-atracurium under 1.3MAC sevoflurane anesthesia remained no difference between genders. But the onset time of women was much faster. Furthermore the effect on the time for T1 to return to 25% ,50% and TOFR 0.7 were greater than men.

Comparison of Propofol ED50 and Insertion Conditions of LMA between Fentanyl and Alfentanil Adjuvant Group / 대한마취과학회지

BACKGROUND: Recent studies suggest that additional use of alfentanil could provide the best condition for the laryngeal mask airway (LMA) insertion. The aim of this study is to compare the median effective dose (ED50) of propofol for the classic LMA insertion and the insertion condition following between fentanyl and alfentanil adjuvant. METHODS: We enrolled 53 patients scheduled for minor surgery under general anesthesia. Patients were randomly allocated to the fentanyl group (n = 24) and the alfentanil group (n = 29) in double blind manner. For fentanyl group, 1microgram/kg of fentanyl was injected intravenously 90 sec before propofol. The afentanil group received 4microgram/kg of alfentanil and propofol coincidently. The insertion of LMA was attempted 90 sec after propofol administration. In accordance with Dixon's up-and-down method, the dose of propofol for consecutive patients in each group was varied with increments or decrements of 0.5 mg/kg based on the previous insertion results of patients. RESULTS: In the fentanyl and alfentanil group, the ED50 of propofol for LMA insertion according to Dixon's method was 2.0 +/- 0.3 mg/kg and 1.8 +/- 0.3 mg/kg, respectively. In addition, the ED50 of propofol of the fentanyl and alfentanil group according to probit regression model, 1.7 mg/kg (95% confidence interval, 1.2-2.2) and 1.7 mg/kg (1.3-2.0) were calculated respectively. There is no significant difference between the two groups. CONCLUSIONS: There was no significant difference in propofol ED50 for insertion of LMA and insertion condition between the alfentanil and the fentanyl group.

Method for determination of the effective dose ED50

There are 4 principle of determination of ED50, the dose effective on 50% of experimental animals. Animals had been distributed into various analogue for diverse doses of studied substance. The evaluation will be carried according to the principle of "yes/no". For 1st example: To determine ED50 concerning the anti-fibrillation effect of venous infective propranolol on BaCl2 included heart fibrillation experimental model of rabbit.Result showed an efficacious dose of ED50 = 1,97mg/kg. For 2nd example: to determine ED50 concerning the hypoglycemic effect of glibenclamid on alloxan included hyperglycemic experimental model on white rat. Result showed on efficacious dose of ED50 = 6,02mg/kg

Anticonvulsant activity of allopregnanolone against pentylenetetrazol- induced seizures in rodents / 中国组织工程研究

Objective To examine the protective effects of allopregnanolone against pentylenetetrazol- induced seizures. Methods The protective effects of allopregnanolone against pentylenetetrazol- induced seizures were studied in C57 mice and SD rats 15 minutes after vehicle or drug intraperitoneal (ip) administration. Results The pretreatment with the allopregnanolone produced a dose- dependent protective effect against pentylenetetrazol- induced seizures. The potencies (ED50 values) were 4.7 mg/kg and 9.8 mg/kg for mice and rats, respectively. Conclusion Allopregnanolone has anticonvulsant activity against pentylenetetrazol- induced seizures in rodents.

Effect of Duration of Lower Motor Neuron Injury on Mivacurium-induced Muscluar Relaxation in Rabbits / 대한마취과학회지

BACKGROUND: The purpose of this study was to investigate whether the effects of mivacurium on muscular relaxation were similar by the duration of more than 2 weeks after the injury of lower motor neurons in rabbits. METHODS: The animals were divided into five groups. The control group was without lower motor neuron injury. In the experimental groups, the lower motor neuron injury was made by denervating with 75 - 80% lesion on the common peroneal nerve to the right anterior tibialis muscle. The experimental groups were subdivided as 1, 2, 3 and 4 week groups (referred to ad the 1 wk, 2, 3 and 4 wks group) according to the durations of the denervation of common peroneal nerve, respectively. The dose-response relationship of mivacurium on the muscle twitches induced by TOF (train of four) stimulation (supramaximal stimulus of 0.2 ms duration, square-wave pulses, 2 Hz rate, repeated every 10 seconds) was studied by calculating ED50 and ED95 in the anterior tibialis muscles and compared between all groups. After recording the muscle twitches, microscopic findings were observed. RESULTS: The effective dose for 95% twitch depression (ED95) of mivacurium at 1week after denervation was significantly higher than that of the control group (P <0.05), but the ED95 of 2, 3 and 4wks groups were not significantly different from that of the control group. However, the ED95 of 3 and 4wks group were inclined to be lower than that of the control and significantly lower than 1wk group (P < 0.05). There was no significant difference in the effective dose for 50% twitch depression (ED50) of mivacurium in all groups. The size of the anterior tibialis muscle was significantly decreased at 4weeks after the lower motor neuron injury (P <0.05), but the number of its sarcoplasmic nuclei was increased, according to the duration after the denervation. CONCLUSIONS: Our results therefore suggest that neuromuscular response of denervated anterior tibial muscle was resistant to intravenous mivacurium in early periods of 1 or 2 weeks but sensitive 4 weeks after the lower motor neuron injury.

Analgesic and Anti-inflammation Effect of Borneol / 中药新药与临床药理

Objective To observe the analgesic action and anti-inflammation effect of borneol. Methods The analgesic action and anti-inflammation effect of borneol were observed by mouse hot-plate test,mouse acetic-acid-induced twisting test,mouse abdominal cavity capillary permeability increase test induced by acetic acid,and rat pedal swelling test induced by carrageenin. Results Borneol reduced the pedal swelling of rats,ED50=0.3242 g?kg-1,increased pain threshold in mice ED50=0.3870 g?kg-1,inhibited twisting response of mice obviously,ED50=0.5813 g?kg-1. In the same dose,the analgesic action of borneol was stronger than the anti-inflammatory effect. Conclusion Borneol has certain analgesic action and anti-inflammation effect.

Protective effects of allopregnanoloneagainst different seizure models in mice / 中国临床药理学与治疗学

Aim To examine the protective effects of allopregnanolone against seizure on different animal models.Methods The protective effects of allopregnanolone against maximal electrical seizure (MES) and picrotoxin-induced seizure were studied in C57 mice 15 minutes after vehicle or drug intraperitoneal administration.Results In the MES test, we found that pretreatment with the phenobarbital or allopregnanolone produced a dose-dependent protective effect against seizure. The potency (ED50 value) of phenobarbital in the MES test was 2.40 mg?kg-1, with 95% confidence interval range from 1.22 to 4.72 mg?kg-1. The potency (ED50 value) of allopregnanolone in the MES test was 0.086 mg?kg-1, with 95% confidence interval range from 0.037 to 0.201 mg?kg-1, which was significantly higher than that of phenobarbital (P

Protective effects of allopregnanolone against different seizure models in mice / 中国临床药理学与治疗学

Aim To examine the protective effects of allopregnanolone against seizure on different animal models.Methods　The protective effects of allopregnanolone against maximal electrical seizure (MES) and picrotoxin-induced seizure were studied in C57 mice 15 minutes after vehicle or drug intraperitoneal administration.Results　In the MES test, we found that pretreatment with the phenobarbital or allopregnanolone produced a dose-dependent protective effect against seizure. The potency (ED50 value) of phenobarbital in the MES test was 2.40 mg·kg-1, with 95% confidence interval range from 1.22 to 4.72 mg·kg-1. The potency (ED50 value) of allopregnanolone in the MES test was 0.086 mg·kg-1, with 95%confidence interval range from 0.037 to 0.201 mg·kg-1, which was significantly higher than that of phenobarbital (P<0.01). The combination study of half ED50 values of phenobarbital and allopregnanolone resulted in a 80% of protective effect in MES test, which was higher than 50% produced by either phenobarbital or allopregnanolone at their ED50 values respectively. This result indicated that there was a synergism between phenobarbital and allopregnanolone in their anticonvulsant activities. In the picrotoxin test, we found that pretreatment with the allopregnanolone also produced a dose-dependent protective effect against picrotoxin-induced seizure. The potency of allopregnanolone in the picrotoxin seizure test was 0.123 mg·kg-1, with 95% confidence interval range from 0.058 to 0.263 mg·kg-1.Conclusion　Allopregnanolone(ip) could protect different seizures in a dose-dependent manner,had a higher potency than phenobarbital,and had synergism with phenobarbital in the MES test.

Are the Requirements of Propofol Decreased in Early Pregnancy during Anesthetic Induction? / 대한마취과학회지

BACKGROUND: Minimum alveolar concentration (MAC) is decreased during pregnancy, but there are no data regarding the requirements for intravenous agents. Recently only one study showed that the requirement for thiopental in pregnant women of 7-13 weeks' gestation was less than the requirement obtained in nonpregnant women. Thus we wanted to determine whether pregnant patients needed less propofol for hypnosis and anesthesia than nonpregnant patients. METHODS: One hundred nonpregnant women having gynecologic surgery and 100 pregnant women of 5-13 weeks' gestation undergoing elective abortions were recruited. They were randomly allocated 10 groups according to the doses of propofol and each group had 10 patients. During a period of 30 seconds, one of the doses of propofol 1.0, 1.25, 1.5, 1.75, 2.0, 2.25, 2.5, 2.75, 3.0 or 3.25 mg/kg was administered. Two minutes later, patients were asked to open their eyes as a test for hypnosis. Patients who did not open their eyes were given a 10 seconds, 50-Hz, 80-mA transcutaneous tetanic electrical stimulus to the ulnar nerve as a test for anesthesia. Estimates of ED50 and ED95 for hypnosis and anesthesia were obtained by logistic regression. RESULTS: In the pregnant women, the median effective doses (ED50) (95% confidence interval) for hypnosis and anesthesia were 1.25 (1.13-1.35) mg/kg and 2.71 (2.49-3.04) mg/kg, the ED95 (95% CI) were 1.51 (1.16-1.87) mg/kg and 3.04 (2.80-3.58) mg/kg respectively. Whereas in the nonpregnant women, the ED50 for hypnosis and anesthesia were 1.27 (1.39-1.90) mg/kg and 4.12 (3.50-6.01) mg/kg, the ED95 were 1.53 (1.41-1.93) mg/kg and 4.35 (3.66-7.26) mg/kg respectively. CONCLUSIONS: In early pregnant women, the doses of propofol for hypnosis and anesthesia were 1.6% and 34.2% less compared with those in nonpregnant women.

The protecting effect of levofloxacin hydrochloride on the systemic infection in mice / 重庆医科大学学报

Objective:To study and evaluate the protecting effect of levofloxacin hydrochloride on systemic infection in mice. Methods :960 mice were used,and divided randomly into 96 groups. Certain amount of E. coli,S. aureus,P. aeruginosa and S. flexneri were administered respectively into the mice and all of them were infected. Immediately after being infected,each group of mice were given different doses of intravenous or oral levofloxacin hydrochloride and of loxacin, in order to determine the protective effect of levofloxacin hydrochloride on the mice infected with these four bacteria. Results: The intravenous injection of ED50 of levofloxacin hydrochloride to the bacteria strains was 0.359mg/kg,5.848mg/kg,22.894mg/kg and 0. 371mg/kg respectively;and ED50through the oral route was 0. 554mg/kg,8. 129mg/kg,28. 895mg/kg and 0. 492mg/kg respectively. Conclusion :The protecting effect through intravenous injection of levofloxacin hydrochloride on systemically infected mice is more superior to that of the oral route,and also better than ofloxacin.

THE TOXICITY OF XIXIN OIL AND ITS EFFECT ON EKG OF RABBITS / 中国药理学通报

Xixin [Asarum heterotropoides Fr. Schmidt Var mandshuricum ( Maxim ) kitag] is a Chinese drug which has a little toxicityas recorded in ancient Chinese medical books. It was demon-strated in this article that the toxicity of Xixin was caused by itsessential oil. When the mice were administered with Xixin oil and its decoction without oil in equal doses separately, the mortality rate for the oil group was 70%, whereas no death was observed in the group of decoction without oil. By synchronous recording the EKG and EEG of cerebral cortex, hippocampus and reticular formation of midbrain in the rabbits, it was revealed that the EKG underwent following changes after the administration of Xixin oil: fast wave of low amplitude→slow wave of high amplitude→slow wave of low amplit ude→burst-suppression pattern→electrical silence. EEG vanished after the electrical silence of cerebral cortex,hippocampus and midbrain reticular formation.The LD50 and ED50 of Xixin oil was calculated 27.0?0.4ml/kg and 18.3?0.8ml/kg respectively,safety coefficient 1.47, being significantly less than control drug sodium amytal.