Interlaboratory method validation of slope ratio determination for anticoagulant activity of leeches / 中国药理学通报

Aim To investigate the slope ratio method for the determination of anticoagulant activity of leeches. Methods Three batches of leeches, four groups of Japanese medical vermiculite yinpian and fifteen groups of leech preparations were chosen, with contrast medicinal leeches herbs and Philippine cattle leech contrast medicinal materials, and different concentrations of leaching solutions were prepared in parallel. APTT value was determined after anticoagulant activity was determined by slope ratio method for the joint validation of laboratory, intermediate precision and accuracy between the linear range. Results The slope ratio method was accurate and accurate in the determination of anticoagulant activity of leeches, with linearity between 64% and 156% relative titer level. Conclusion Slope ratio method can be used to determine the anticoagulant activity of leeches.

Interim In vitro Dose-Response Curve for the Dicentric Biodosimeter Assay from a Philippine Radiotherapy Facility using a Linear Accelerator

@#Background. Accidental radiation exposure can occur anytime. Biodosimeters help in quantifying the absorbed dose of individuals who are not equipped with personal dosimeters during radiation exposure. The dicentric assay can quantify radiation damage by correlating radiation dose exposure with the frequency of dicentric chromosomes in the peripheral lymphocytes extracted from exposed individuals. Objective. The study aims to present the interim results of the reference dose-response curve for a Philippine radiotherapy facility constructed using a 6MV linear accelerator (ClinacX, Varian). Methods. Samples of peripheral blood from healthy volunteers were irradiated in a customized water phantom of doses 0.10 to 5.0 Gray using a linear accelerator. The irradiated samples were cultured and analyzed following the International Atomic Energy Agency Cytogenetic Dosimetry Protocol (2011) with modifications. Linear-quadratic model curve fitting and further statistical analysis were done using CABAS (Chromosome Aberration Calculation Software Version 2.0) and Dose Estimate (Version 5.2). Interim results of the samples were used to generate these curves. Results. The dose-response curve generated from the preliminary results were comparable to published dose response curves from international cytogenetic laboratories. Conclusion. The generated dose-response calibration curve will be useful for medical triage of the public and radiologic staff accidentally exposed to radiation during medical procedures or in the event of nuclear accidents.

Establishment and validation of the dose-response curve of X-rays irradiation and chromosome aberrations in human peripheral blood cells / 中国职业医学

OBJECTIVE: To explore the dose-effect of X-ray irradiation and chromosome aberrations in human peripheral blood cells,and establish a dose-response curve of dicentric and ring(dic+r)aberration induced by X-ray irradiation.METHODS: Human peripheral blood samples were collected from three healthy individuals and were exposed to X-ray at the doses of 0.00,0.25,0.50,0.75,1.00,2.00,3.00,4.00 and 5.00 Gy in vitro.The dose rate was 1.158 Gy/min.The blood cells were harvested after routine culture,and the chromosome preparation was carried out.The dicentrics and rings in metaphase cells were counted under microscope,and a dose-response curve was fitted by using the software of CABAS.Dose estimation was performed according to the curve from two blind samples.RESULTS: Aberration of dic+r increased with irradiation doses in the range of 0.00-5.00 Gy(P<0.01).The dose-response relationship followed a linear-quadratic equation:■,where■ is the yield of dic+r,and D is the irradiated dose.The estimated doses of the two blind samples were in accordance with the actual doses.CONCLUSION: The dose-response curve and mathematical model of chromosome aberration following exposure to 0.00-5.00 Gy X-ray irradiation is established in this study provide a reliable method for the accurate dose estimation.

Photosynthetic physiological characteristics of Angelica dahurica var.formosana from Sichuan province in different growth years / 中国中药杂志

In this study,the leaves of autumn-sown Angelica dahurica var. formosana from Sichuan province in different growth years was used to explore the fitting model of photosynthetic response curve and the different photosynthetic physiological characteristics between annual and biennial A. dahurica var. formosana from Sichuan province. The results showed that the fitting model of the optimum light response curve of the leaves of A. dahurica var. formosana from Sichuan province with different growth years was all rectangular hyperbolic correction model. The light saturation points were 1 600,1 700 μmol·m-2·s-1,the light compensation points were17. 98,52. 23 μmol·m-2·s-1 in the leaves of annual and biennial plant,respectively. The diurnal variation curves of net photosynthetic rate,transpiration rate and stomatal conductance in the leaves all acted as a single peak value wave. The daily mean values of net photosynthetic rate and transpiration rate in the leaves of biennial plant were significantly higher than that of annual plant. There was no significant difference in daily mean stomatal conductance. The net photosynthetic rate was significantly positively correlated with stomatal conductance in both of the different growth years. The net photosynthetic rate of annual and biennial A. dahurica var. formosana from Sichuan province had extremely significant and significantly negative correlation with the intercellular CO2 respectively. The transpiration rate of annual plant was positively correlated with the effective photosynthetic radiation intensity and air temperature,but had significantly negative correlation with the intercellular CO2 concentration. The transpiration rate of biennial plant had extremely positive correlation with the effective photosynthetic radiation intensity,and negatively correlated with the intercellular CO2 concentration. In conclusion,the photosynthetic efficiency of the leaves in biennial plant of A. dahurica var. formosana from Sichuan province was higher than that in annual plant,but the ability to utilize weak light was lower than that of annual plant. It should be planted in the sunny field.

Effects of obesity on dose-response curve of rocuronium in female patients / 临床麻醉学杂志

Objective To observe the effects of obesity on dose-response curve of rocuronium in female patients and calculate ED9 5 of rocuronium.Methods Eighty female patients,aged 18-45 years, falling into ASA grade Ⅰ or Ⅱ,schedualed for elective surgery under general anesthesia,undergoing surgery less than 1.5 h,were included in the study.The patients with body mass index of 20-25 kg/m2 as group N were randomized to divided group N1,group N2,group N3 and group N4.Anoth-er 40 patients with body mass index of 30-35 kg/m2 as group B were randomized to divided group B1, group B2,group B3 and group B4.When the first twitch height of TOF (T1)was 100%,groups N1-N4 and groups B1-B4 patients were injected rocuronium 0.075,0.1,0.1 5,0.3 mg/kg respectively. The first dose of rocuronium in each group,T1 maximum inhibition degree and onset time were re-corded.The relationship between probit-transformed depression of T1 and the logarithm dose of rocu-ronium was analyzed by linear regression.ED50 and ED9 5 of rocuronium in obese and normal body weight patients were calculated.Results Dose-response curve equation of each group were Y1 =3.464X1 -2.23 and Y2 = 3.843X2 - 2.750 respectively(P < 0.05 ).The ED50 and ED9 5 (95% CI)of rocuronium were 0.122 (0.092-0.1 65 )mg/kg and 0.324 (0.242-0.433 )mg/kg in group N,and were 0.103 (0.078-0.133)mg/kg and 0.25 1 (0.1 93-0.326)mg/kg in group B.Conclusion Obesity significantly affects the dose-response curve of young women and can enhance the sensitivity of them to the rocuronium.The ED9 5 of obese patients is 0.25 1 mg/kg.

Establishing dose-response curve of chromosome aberration induced by in vitro X-ray irradiation in human peripheral blood / 中国职业医学

OBJECTIVE: To establish the dose-response curve of chromosome aberration induced by X-ray irradiation in human peripheral blood in vitro. METHODS: The median cubital vein blood of healthy male donors were collected and irradiated with X-ray at the dose of 0. 00-5. 00 Gy in vitro. The dose rate was 0. 8 mGy/s. The cells were cultured with colchicine and stained with routine Giemsa staining. The slices were blindly examined. The morphology of chromosomes were recorded as dicentric,multi-centric,dicentric plus rings or fragments( hereinafter referred to as dicentric + ring) in metaphase cells. The occurrence of dicentric + ring and the irradiation dose was used to create the dose-response curve.RESULTS: The results showed that the occurrence of dicentric + ring in abnormal cells increased with the increasing irradiation dose in the range of 0. 00-5. 00 Gy( P < 0. 01). The best fitting equation of 0. 00-1. 00 Gy is y = 23. 22 D2+4. 768 D-0. 018( P < 0. 01). The best fitting equation of 0. 50-5. 00 Gy is y = 34. 23 D-3. 072( P < 0. 01).CONCLUSION: The fitting degree of dose-response curve is good,which can be used as reference in laboratory to assess irradiation exposure dose.

Study on quality control methods of Fuzheng Xiaoji capsule based on biological detection method / 中国生化药物杂志

Objective To establish biological detection method for Fuzheng Xiaoji capsule.MethodsTaken Radix astragali,Hedyotis diffusa Willd, Fructus Polygoni orientalis and rhubarb in Fuzheng Xiaoji capsule as targets, the antimicrobial activity of the single fried mixture of Radix astragali,Hedyotis diffusa Willd,Fructus Polygoni orientalis and rhubarb to 4 kinds of standard strains(Staphylococcus aureus, Salmonella, Escherichia coli and Bacillus subtilis) were inspected.The standard curve by susceptible strains of the inhibition zone diameter and logarithm of the concentration was established,and this test also determined the biological potency of different batches of Fuzheng Xiaoji capsule according to the dose-response curve.ResultsThe single fried mixture of Radix astragali,Hedyotis diffusa Willd, Fructus Polygoni orientalis and rhubarb have strong anti-bacterial effect to the above four standard strains.There was a good linear relationship between logarithmic dose and response effect when the concentration in the range of 0.029-0.136g/mL(r=0.9583).ConclusionBiological potency detection method can be combined with traditional analysis methods to control the quality of Fuzheng Xiaoji capsule.

Biomass allocation and gas exchange are affected by light conditions in endangered Cedrela salvadorensis (Meliaceae) seedlings / Asignación de biomasa e intercambio de gases son afectados por las condiciones de luz en plántulas de Cedrela salvadorensis (Meliaceae) en peligro de extinción

Abstract:The determination of favorable light habitat conditions per species and life stage is transcendental, for both ex situ and in situ conservation strategies of endangered forest tree species, and for their utilization as plantation trees. This becomes especially important when planting material is scarce. We studied the multivariate responses in biomass allocation and in gas exchange to light and to CO2 in Cedrela salvadorensis seedlings, grown under similar light conditions as those this species faces in nature. During a period of 135 days, groups of ten seedlings were put under 75, 45, 15 and 3.5 % of full sun exposure obtained with neutral shade cloth, under nursery conditions. A series of biomass allocation variables and detailed gas exchange parameters (photosynthesis response curves to light and to internal carbon concentration) were measured at the end of the growth period in plants of the four treatments. According to the principal component analyses, highest values of gas exchange response were associated with the lower values of biomass allocation traits. These changes can be associated with resource-conservative and resource-acquisitive strategies, where the C. salvadorensis seedlings acclimatize their traits for the exploration and exploitation of light, to high or to dim light environment, respectively. The multivariate analyses also showed that the plants had a high performance at 45 % of light environments. These results suggest that 45 % of light environment was the optimal light habitat of this species at the tested developing stage. Our results have important implications to choose the best natural habitat for a successful establishment of C. salvadorensis. We propose practical considerations for programs of reforestation or reintroduction where this species be involved. Rev. Biol. Trop. 64 (3): 1143-1154. Epub 2016 September 01.

ResumenLa determinación de las condiciones lumínicas favorables por especie y estado de vida es trascendental para las estrategias de conservación ex situ y in situ de especies de árboles en peligro de extinción, y su utilización como plantaciones forestales. Esto se vuelve especialmente importante cuando el material de siembra es escaso. Aquí, nosotros estudiamos las respuestas en asignación de biomasa y en intercambio de gases a luz y CO2 en plántulas de Cedrela salvadorensis crecidas bajo condiciones lumínicas similares a las que esta especie enfrenta en la naturaleza. Durante 135 días, grupos de diez plántulas fueron colocadas bajo condiciones de 75, 45, 15 y 3.5 % de exposición total al sol obtenidas por medio de sarán bajo condiciones de vivero. Una serie de variables de asignación de biomasa y parámetros de intercambio de gases (fotosíntesis según curvas de respuesta a la luz y a la concentración de carbono interno) fueron medidas al final del periodo de crecimiento en las plantas de los cuatro tratamientos. De acuerdo con los análisis de componentes principales, valores altos de respuesta de intercambio de gases están asociados con valores bajos de rasgos de asignación de biomasa. Los cambios observados se encuentran asociados con las estrategias recurso-conservativas y recurso-adquisitivas donde C. salvadorensis aclimata sus rasgos para la exploración y explotación de luz en ambientes con escasa o excesiva radiación lumínica, respectivamente. Los análisis multivariados muestran también que las plantas tienen un alto rendimiento a 45 % de luz ambiental. Estos resultados sugieren que el 45 % de ambiente lumínico es el hábitat lumínico óptimo de esta especie en el estado de desarrollo estudiado. Nuestros resultados tienen importantes implicaciones para escoger el mejor hábitat natural para un exitoso establecimiento de C. salvadorensis. Por esto, proponemos consideraciones prácticas para programas de reforestación y reintroducción donde esta especie estaría involucrada.

Effects of Arbuscular Mycorrhiza on Osmotic Adjustment and Photosynthetic Physiology of Maize Seedlings in Black Soils Region of Northeast China

ABSTRACT To investigate the effect of arbuscular mycorrhiza fungi on maize growth, osmoregulation substances and photosynthetic physiology, a popular maize variety ZD 958 was measured under potted condition. Arbuscular mycorrhiza (AM) symbiosis promoted plant growth, and enhanced plant height, leaf length, mean leaf width and dry weight. Higher soluble sugar and protein, but lower proline concentrations were detected in AM seedlings than corresponding non-AM seedlings. Quantum yield of PSII photochemistry and potential photochemical efficiency increased by arbuscular mycorrhiza fungi, meanwhile, AM plants had lower primary fluorescence but higher maximal fluorescence and variable fluorescence than non-AM plants. AM enhanced apparent quantum efficiency, maximum net photosynthetic rate, dark respiration rate and light saturation point, but reduced light compensation point. The conclusion was that, after the seedling inoculated with Glomus. tortuosum, AM symbioses could protect cell from being hurt through regulating substances related to osmotic adjustment, besides, the efficiency of light utilization, the capacity of using low light and the capacity of fitting and using high light were all increased by AM symbiosis.

Potency Determination of Lonicera Granule Based on Bacterial Inhibitory Activity / 中国药师

Objective:To explore the chemical-biological evaluation pattern for the quality control and evaluation of Chinese materia medica solid preparations( CMMSP) according with the characteristics of Chinese traditional medicines. Methods:Lonicera granule as the model drug, the bacteria sensitive tests [minimal inhibitory concentration (MIC) and minimal bactericidal concentration(MBC)] were applied to study the antimicrobial effect of Lonicera extract on 4 kinds of standard strains ( Staphylococcus aureus, Streptococcus pneumoni-ae, Escherichia coli and Pseudomonas aeruginosa). The standard curves of the relationship between the anti-bacterial ring diameter for sensitive bacterial and the concentration of Lonicera extracts were established, and the biological potency of Lonicera granule from differ-ent manufacturers was calculated and compared with the result of the HPLC method ( measured by chlorogenic acid) . Results:The anti-microbial test showed that Staphylococcus aureus, Streptococcus pneumoniae, Escherichia coli and Pseudomonas aeruginosa were susceptible to Lonicera, and the antibacterial circle edge for Staphylococcus aureus was clear with higher sensitivity. There was a good linear relation-ship between the logarithmic dose and the response effect when the concentration of Lonicera was within the range of 0. 014 2-0. 068 0 g· ml-1(r=0.990 9). Conclusion:As a quality control method for Lonicera and Lonicera granules, the bioassay is feasible, which can ef-fectively cooperate with the traditional test method for the quality control of Lonicera and its preparations.

Antimicrobial efficacy of Althaea officinalis Linn. seed extracts and essential oil against respiratory tract pathogens.

In present study, Althaea officinalis seed extracts and essential oil were screened for antimicrobial activity against five bacteria and one fungi responsible for dominant, lethal or opportunistic infection of respiratory regions. The maximum inhibition was noted by essential oil against Streptococcus pyogenes (21.3±0.28 mm) and Haemophilus influenzae (19.0±0.50 mm) at 200 mg/ml. The minimum inhibitory concentration values for methanol extract was 3.12-12.5 mg/ml. The antifungal activity noted highest with 41.28% by essential oil and 36.27% inhibition by aqueous extract represented by dosage-response curve.

Effects of light and temperature on isoprene emission at different leaf developmental stages of eschweilera coriacea in central Amazon / Efeitos da luz e da temperatura sobre a emissão de isopreno em diferentes estádios de desenvolvimento foliar de eschweilera coriacea na Amazônia Central

Isoprene emission from plants accounts for about one third of annual global volatile organic compound emissions. The largest source of isoprene for the global atmosphere is the Amazon Basin. This study aimed to identify and quantify the isoprene emission and photosynthesis at different levels of light intensity and leaf temperature, in three phenological phases (young mature leaf, old mature leaf and senescent leaf) of Eschweilera coriacea (Matamatل verdadeira), the species with the widest distribution in the central Amazon. In situ photosynthesis and isoprene emission measurements showed that young mature leaf had the highest rates at all light intensities and leaf temperatures. Additionally, it was observed that isoprene emission capacity (Es) changed considerably over different leaf ages. This suggests that aging leads to a reduction of both leaf photosynthetic activity and isoprene production and emission. The algorithm of Guenther et al. (1999) provided good fits to the data when incident light was varied, however differences among E S of all leaf ages influenced on quantic yield predicted by model. When leaf temperature was varied, algorithm prediction was not satisfactory for temperature higher than ~40 °C; this could be because our data did not show isoprene temperature optimum up to 45 °C. Our results are consistent with the hypothesis of the isoprene functional role in protecting plants from high temperatures and highlight the need to include leaf phenology effects in isoprene emission models.

O isopreno emitido pelas plantas corresponde em cerca de um terço das emissões globais de compostos orgânicos voláteis anualmente. A maior fonte de emissão de isopreno para a atmosfera global é a Bacia Amazônica. Este estudo objetivou identificar e quantificar a emissão de isopreno e fotossíntese em diferentes níveis de intensidade de luz e temperatura foliar, em três fases fenológicas (folha madura recente, folha madura tardia e folha senescente) de Eschweilera coriacea (Matamatá verdadeira) - a espécie com maior distribuição na Amazônia central. In situ, as medidas de fotossíntese e emissão de isopreno da folha madura recente apresentaram as maiores taxas em todos os níveis de luz e de temperatura. Adicionalmente, a capacidade de emissão de isopreno (ES) mudou consideravelmente entre as diferentes idades foliares, sugerindo que o envelhecimento reduz a atividade fotossintética e a produção/emissão de isopreno. O algoritmo de Guenther et al. (1999) demonstrou bom ajuste para a emissão de isopreno em diferentes intensidades de luz, entretanto, diferenças na ES entre as idades foliares influenciaram no rendimento quântico estimado pelo modelo. Em relação à temperatura foliar, a estimativa do algoritmo não foi satisfatória para as temperaturas acima de ~40 °C; isto provavelmente ocorreu pelo fato dos dados não apresentarem temperatura ótima até 45 °C. Nossos resultados são consistentes com a hipótese do isopreno ter um papel funcional para proteger as plantas de altas temperaturas e apontam a necessidade de incluir os efeitos da fenologia foliar em modelos de emissão de isopreno.

Investigating the dose-response curves of cisatracurium in the different gender epileptics / 临床麻醉学杂志

Objective To evaluate the gender differences in dose-response curve with cisatra-curium in epileptics.Methods Eighty ASA grade Ⅰ or Ⅱ epileptics were enrolled in this study.All patients were divided into male and the female groups and received the method of single dose injection under midazolam-fentanyl intravenous anesthesia.Each patient received intravenous bolus of 20,30, 40,50μg/kg of cisatracurium respectively.The neuromuscular block was measured by Neuromuscular Transmission Monitor and the responses were defined in terms of the percentages of maximum sup-pression in T1 of TOF of the adductor pollicis muscle.According to log-probit transformation of the data of dose and response,the dose-response curve of cisatracurium was established through linear re-gression.The onset time of cisatracurium was also observed.Results The ED50 ,ED75 ,ED90 ,ED95 values of cisatracurium in male epilepsy patients were 37.2±9.7,48.1±11.3,60.4±12.8,69.3± 14.0 μg/kg and that of female epilepsy patients were 36.6±4.3,47.5±7.7,60.5±14.0,70.1± 19.4 μg/kg.There was no significant difference between the two gender groups.No significant change in onset time was observed among 4 dose groups.Conclusion No gender differences are ob-served in dose-response curve of cisatracurium in epileptics.

Buscando una curva general de respuesta a la quimioterapia basada en la evaluación radiológica con criterio RECIST / Looking for a general response curve to chemotherapy based on radiological evaluation with RECIST criteria

Radiological evaluation of response to chemotherapy can be carried out by applying the RECIST (Response Evaluation Criteria in Solid Tumors) criteria, currently considered the most objective method for monitoring lesions. Aimed at finding a general response curve, 21 patients with lung and kidney tumors, as well as colorectal carcinoma were studied between 2006 and 2008. Statistical proceedings included variance (ANOVA), co-variance (ANCOVA) and logarithmic regression analysis. Target-lesion size reduction, duration of response and overall response of different types of tumors did not differ significantly A general response curve was obtained: log (RR)= 1,897-0,0281, where RRt is the relative RECIST count, and t is time (expressed in months). As an expected outcome -because of variety of drugs, type of tumors and variability rates in individual response- the determination coefficient in regression was 10.9 percent. However, it constitutes a first approach to solid tumors response and proves the accuracy and usefulness of RECIST methodology.

La evaluación radiológica de respuesta a la quimioterapia se puede hacer con el criterio RECIST, considerado actualmente el método más objetivo de seguimiento de lesiones. Con el objetivo de buscar una curva general de respuesta, entre los años 2006 y 2008 estudiamos 21 pacientes con tumores pulmonares, renales y cáncer colo-rectal. La estadística consistió en análisis de varianza (ANOVA), covarianza (ANCOVA) y regresión logarítmica. La reducción en tamaño y el tiempo de respuesta no difirieron significativamente, así como tampoco la respuesta global de los diferentes cánceres. Se obtuvo una curva general de respuesta: log (RR)= 1,897 -0,028 t, (RR= evaluación RECIST actual dividida por inicial y t= tiempo en meses). El coeficiente de determinación de la regresión fue 10,9 por ciento, esperable por la diversidad de fármacos, tipo de tumor y respuesta individual; sin embargo constituye una primera aproximación a la respuesta esperada mostrando la utilidad y objetividad del método.

Respostas fisiológicas ao déficit hídrico em duas cultivares enxertadas de seringueira ("RRIM 600" e "GT 1") crescidas em campo / Physiological responses to water deficit in two young field-grown scion rubber ('RRIM 600' and 'GT 1')

Sob condições de campo, as plantas estão sujeitas a períodos de déficit hídrico no solo e na atmosfera, durante todo o seu ciclo de vida. Foi avaliado o desempenho de duas cultivares enxertadas de seringueira ("RRIM 600" e "GT 1"), mantidas na UNESP-IBILCE, em São José do Rio Preto, SP, com e sem suplementação hídrica, a partir da idade de quatro meses. A resistência máxima ao período seco ininterrupto, considerada quando cessou a realização de fotossíntese com ganho líquido, foi de 17 e 20 dias, respectivamente. Trinta e três dias após a suspensão do estresse, a recuperação das trocas gasosas foi bastante similar para as duas cultivares, e apenas a concentração de dióxido de carbono intercelular retornou a valores equivalentes aos dos controles. Apenas o incremento relativo da área foliar, para "GT 1", e da altura, para "RRIM 600", não diferiram aos do grupo controle (P=0,05). As curvas de resposta à luz indicaram, para ambos os clones, decréscimos para a irradiância de compensação e a taxa fotossintética (P=0,05). Embora parcial, a melhor recuperação após o estresse foi verificada para "GT 1".

During their life cycle, plants growing under field condition are subject to periods of air and soil water deficits. In this study was evaluated the performance of two scion cultivar of rubber tree ('RRIM 600' and 'GT 1') growing in São José do Rio Preto, SP, with and without water supplementation since the age of 4 months. The maximum resistance to the uninterrupted dry period, considered when net photosynthesis was ceased, was 17 and 20 days, respectively. Thirty-three days later the water stress was ceased, the gas exchange recovery for both cultivars were quite similar, but just the intercellular carbon dioxide concentration returned to similar values of the control group. Only the relative increment of leaf area to 'GT 1', and plant height of 'RRIM 600' was similar to the control group (P=0.05). The light curve response showed, for both clones, decrease of the compensation irradiance and photosynthetic rate (P=0.05). Although partial, the best recovery after water stress was observed for 'GT 1'.

Effects of Nimodipine on Dose-Response Curves of Vecuronium, Rocuronium, and Atracurium Using Phrenic Nerve-Diaphragm Preparations of Rats / 대한마취과학회지

BACKGROUND: Interactions between nimodipine, a calcium channel blocker, used perioperatively for the treatment of subarachnoid hemorrhage, and vecuronium, rocuronium, and atracurium were studied with phrenic nerve-hemidiaphragm preparations of rats. METHODS: Male 200-300 g Sprague-Dawley rats were randomly allocated into four groups (control, NMD(5), NMD(50) and NMD(500) group, n = 10, respectively) according to the nimodipine concentration, and three groups (control, NMD(2D) and NMD(7D), n = 10, respectively) according to the pretreatment duration. A square wave 0.1 Hz supramaximal stimuli was applied to the phrenic nerve-hemidiaphragm preparation and the twitch height response was recorded with mechanomyography. The dose-response curves were measured, and ED(5), ED(50), ED(90), and ED(95) of each vecuronium, rocuronium, and atracurium in different concentrations of nimodipine of 5, 50, and 500 ng/ml and rocuronium in pretreatment with nimodipine 2.5 mg/kg/d for 2 and 7 days were calculated using an inhibitory sigmoid Emax model. RESULTS: The dose-response curves of rocuronium and atracurium were significantly shifted to the left in NMD(500) group, and significantly shifted to the right in NMD(7D) group (P < 0.05). In NMD(500) group, ED(50), ED(90), and ED(95) of rocuronium and atracurium were significantly reduced, and those of rocuronium in NMD7D group were significantly increased compared with the control group (P < 0.05). CONCLUSIONS: Nimodipine 500 ng/ml in the phrenic nerve-hemidiaphragm preparation of rat increased sensitivity to rocuronium and atracurium, and the dose-response curve was significantly shifted to the left, but following pretreatment for 7 days, nimodipine decreased the potency of rocuronium, and the dose-response curve was significantly shifted to the right.

Effects of Phenytoin on Rocuronium-induced Neuromuscular Blockade Using a Rat Phrenic Nerve-diaphragm Preparation / 대한마취과학회지

BACKGROUND: Chronic anticonvulsant therapy with phenytoin antagonizes the action of nondepolarizing muscle relaxants. Rocuronium is a new non depolarizing muscle relaxant of rapid onset and intermediate duration. This study was designed to investigate the effects of phenytoin on rocuronium-induced neuromuscular blockade using a rat phrenic nerve-diaphragm preparation. METHODS: Male Sprague-Dawley rats (200 g, n = 70) were randomly allocated into a control group (C, n = 10), three phenytoin-pretreated groups (PP, n = 30) and three phenytoin-non-pretreated groups (PNP, n = 30). In phenytoin-pretreated groups, phenytoin 50 mg/kg/day was administered intraperitoneally once a day for one day (PP1D), seven days (PP7D) or twenty eight days (PP28D). Animals were anesthetized with 40 mg/kg of thiopental sodium intraperitoneally and the diaphragm with the phrenic nerve were dissected, and the phrenic nerve-diaphragm preparation was suspended in 100 ml of Krebs solution in an organ bath. The bath was aerated with 95% O2-5% CO2 at 32oC, and the phrenic nerve was stimulated with supramaximal intensity using a stimulator. Twitch responses were measured using a precalibrated force displacement transducer and recorded. The cumulative dose-response relationships of rocuronium and phenytoin were determined. After one hour's stabilization, rocuronium 100 microgram was added to the bath, and when a stable 3-5 twitch was obtained, incremental 50 microgram doses of rocuronium were added to obtain more than 95% neuromuscular twitch inhibition at 0.1 Hz. In the phenytoin-non-pretreated group, phenytoin was administered simultaneously with the initial dose of rocuronium to a phenytoin concentration of 1 microgram/ml (PNP1), 10 microgram/ml (PNP10), or 100 microgram/ml (PNP100) in Krebs solution. Data were analyzed by probit and logistic models. In the PP group, the plasma concentration of phenytoin was analyzed by high performance liquid chromatography. RESULTS: The dose-response curve of rocuronium was significantly shifted to the left in the PNP100 group (P < 0.05), and significantly shifted to the right in the PP28D group (P < 0.05). The plasma phenytoin concentration was found to be directly proportional to the duration of the phenytoin pretreatment. CONCLUSIONS: The potency of rocuronium is reduced in chronic phenytoin therapy and increased after an acute high dose of phenytoin.

Effects of Dexamethasone on Neuromuscular Transmission in a Phrenic Nerve-Hemidiaphragm Preparation in the Rat / 대한마취과학회지

BACKGROUND: MacFarlane and Rosenthal reported a case of acute quadriplegia after nondepolarizing muscular blocking agents in status asthmaticus patient treated with high doses of corticosteroid. Reports regarding the reactions of glucocorticoid treated muscles to neuromuscular blocking agents are sparse and inconsistent. The aims of this study were to examine the degree of muscle atrophy and its effects on sensitivity to neuromuscular blocking agents in relation to the dose and duration of dexamethasone. METHODS: Sixty Sprague-Dawley rats were divided into six groups. They were treated daily with dexamethasone 0.4 mg/kg and 4 mg/kg daily for 1 week or 3 weeks. The two control groups were treated with normal saline. The day after treatment, the dose-response curves of vecuronium were measured using a phrenic nerve-hemidiaphragm preparation. To classify muscle fiber, the diaphragm was stained for myofibrillar adenosine triphosphatase after alkaline and acid preincubation, and a morphometric examination was carried out. RESULTS: The diaphragmatic muscle in rats treated with long term, high dose dexamethasone showed significant atrophy. For the short term, low dose dexamethasone group, the ED50 and ED95 of vecuronium decreased 41.5% and 26.8% compared to those of the control group, respectively (P<0.05). However, the ED50 of vecuronium in the long term, high dose dexamethasone group increased 22.2% compared to that of the control group (P<0.05). CONCLUSION: This study suggests that sensitiviy to vecuronium was not modulated by dexamethasone-induced muscle atrophy. Quantitative changes of receptors at the neuromuscular junction or some anoother process might be responsible for this change.

Effects of berberine on left atria and trachea in guinea pigs / 中国临床药理学与治疗学

AIM: To observe the effects of berberine (Ber) on left atria and trachea in guinea pigs. METHODS: The experiment was carried out with isolated left atria and trachea in guinea pigs, and the effects and interactions were compared between Ber and pinacidil (Pin). RESULTS: Ber concentration-dependent increased the force of contractile, while Pin decreased the force. Ber leaded a parallel rightward shift in accumulated response curve of depression contraction of left atria by Car, and it hardly changed the maximum response (E_(max)), while Pin leaded a parallel leftward shift in the same curve. In the combination of Ber and Pin, the dose-response curve hardly changed as the control one. In isolated guinea pig trachea, Ber caused a leftward shift in the dose-response curve of ACh, whereas Pin produced a rightward shift in the same curve without changing E_(max). When both Ber and Pin existed in the same container, there was no modification in the response to ACh. CONCLUSION: Ber shows the effect of blocking potassium channel.

Clinical Impact of Bronchial Reactivity and Its Relationship with Changes of Pulmonary Function After Asthmatic Attack Induced by Methacholine / 결핵

BACKGROUND: Bronchial reactivity is known to be a component of airway hyperresponsiveness, a cardinal feature of asthma, with bronchial sensitivity, and is increments in response to induced doses of bronchoconstric tors as manifested by the steepest slope of the dose-response curve. However, there is some controversy regarding methods of measuring bronchial reactivity and clinical impact of such measurements. The purpose of this study was to evaluate the clinical significance and assess the clinical use by analyzing the relationship of the bronchial sensitivity, the clinical severity and the changes in pulmonary function with bronchial reactivity. METHOD: A total of 116 subjects underwent a methacholine bronchial provocation test. They were divided into 3 groups : mild intermittent, mild persistent, moderate and cough asthma. Severe patients were excluded. Methacholine PC20 was determined from the log dose-response curve and PC40 was determined by one more dose inhalation after PC20. The steepest slope of log dose-response curve, connecting PC20 with PC40, was used to calculate the bronchial reactivity. Body plethysmography and a single breath for the DLCO were done in 43 subjects before and after methacholine test. RESULTS: The average bronchial reactivity was 38.0 in the mild intermittent group, 49.8 in the mild persistent group, 61.0 in the moderate group, and 41.1 in the cough asthma group. There was a weak negative correlation between PC20 and bronchial reactivity. A heightened bronchial reactivity tends to produce an increased clinical severity in patients with a similar bronchial sensitivity and basal spirometric pulmonary function. There were significant correlations between the bronchial reactivity and the initial pulmonary function before the methacholine test in the order of sGaw, Raw, FEV1/FVC, MMFR. There were no correlations between the bronchial sensitivity and the % change in the pulmonary function parameters after the methacholine test. However, there were significant correlations between the bronchial reactivity and the PEF, FEV1, DLCO. CONCLUSION: There was weak significant negative correlation between the bronchial reactivity and the bronchial sensitivity, and the bronchial reactivity closely reflected the severity of the asthma. Accordingly, measuring both the bronchial sensitivity and the bronchial reactivity can be of assistance in assessing of the ongoing disease severity and in monitoring the effect of therapy.