人体股前区皮肤生物力学特性的初步研究

采用ＨＬＣ－１型生物活组织力学试验机对正常成年人股前区皮肤进行生物力学测定。结果表明，股前区皮肤垂直于皮纹方向的应力与应变之间呈指数函数关系，当应变在１．２以内时，应变增加而应力增加不明显，而当应变大于１．２时，应力急剧增加。提示不论伤口缝合及植皮手术时皮肤应变范围应在１．２内为宜。     

Predictive equation for acquisition of hepatitis B in hospital workers in a general hospital

A cross-sectional study was performed to obtain risk factors for hepatitis B disease, HBsAg carriers and immunised personnel, among 2470 workers in a general hospital in Madrid, Spain. The data obtained were analyzed with multiple logistic regression to obtain coefficients for variables. The results of the analysis show that being a nurse or being regularly exposed to blood are the most important risk factors for hepatitis B acquisition. The length of time working at the same job activity was also a risk factor. The resulting coefficients allow the construction of a predictive equation for non-immunised, HBsAg carrier and immunised HBV status, which can select subjects for a hepatitis B vaccination program.     

Saturable rate of cefatrizine absorption after oral administration to humans

This study examined the absorption kinetics of cefatrizine, an amino--lactam antibiotic, after oral administration of a single 500-mg dose to 12 healthy volunteers. Plasma concentrations were determined by high performance liquid chromatography. The plots of the percentage of drug unabsorbed and the apparent rate of cefatrizine absorption as a function of time showed, first, a delay and, then, an almost constant rate of absorption with a tendency to move toward first-order kinetics at the end of the process. Three compartmental models incorporating a lag time and first-order elimination kinetics, but differing in their input rate, were used for analysis of the time course of cefatrizine plasma concentrations. The model with first-order absorption kinetics was clearly inadequate. The results were improved with the model for which the rate of absorption is constant, but a model incorporating saturable absorption kinetics of the Michaelis-Menten type improved the fit further. This last model was statistically superior to the constant-rate input model in 6 out of 12 subjects, according to the likelihood-ratio method. Because of the innovative feature of the model incorporating the Michaelis-Menten equation, simulations of the effect of altering the model parameters and the dose administered on the concentration-time profile, were performed. Different hypotheses which might explain why cefatrizine absorption kinetics fits the Michaelis-Menten equation were examined. The observation of saturable absorption kinetics is consistent with a carrier-mediated transport previously reported to occur in the gastrointestinal tract of rats.     

The acceptance of SARS-CoV-2 rapid antigen self-testing: A cross-sectional study in China

Compared with the nucleic acid amplification test (NATT), the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) rapid antigen self-testing (RAST) has advantages in speed and convenience. However, little is known about people's acceptance and influencing factors for SARS-CoV-2 RAST. A cross-sectional study was conducted from April 21 to 30, 2022 in China. The χ² test and multivariate logistic regressions were used to identify the influencing factors. The structural equation model was used to test the extended protective motivation theory (PMT) model hypotheses. Among the total of 5107 participants, 62.5% were willing to accept the SARS-CoV-2 RAST. There were significant differences in acceptance among different residences (p < 0.001), educational level (p < 0.001), occupation (p < 0.001), monthly income (p < 0.001), travel frequency (p < 0.05), and feelings about NATT (p < 0.001). Response efficacy (β = 0.05; p = 0.025) and self-efficacy (β = 0.84; p < 0.001) had a positive effect, while response cost showed a negative effect (β = −0.07; p < 0.001). The public's major concerns about SARS-CoV-2 RAST are its reliability, testing method, price, and authority. Overall, a moderate intention to use SARS-CoV-2 RAST was found among the Chinese population. The extended PMT can be used for the prediction of intention to accept the RAST. We need to take measures to increase people's acceptance of SARS-CoV-2 RAST.     

The Relationship Between Protein Aggregation and Molecular Mobility Below the Glass Transition Temperature of Lyophilized Formulations Containing a Monoclonal Antibody

Purpose. To find out if the physical instability of a lyophilized dosage form is related to molecular mobility below the glass transition temperature. Further, to explore if the stability data generated at temperatures below the glass transition temperature can be used to predict the stability of a lyophilized solid under recommended storage conditions. Methods. The temperature dependence of relaxation time constant, , was obtained for sucrose and trehalose formulations of the monoclonal antibody (5 mg protein/vial) from enthalpy relaxation studies using differential scanning calorimetry. The non-exponentiality parameter, , in the relaxation behavior was also obtained using dielectric relaxation spectroscopy. Results. For both sucrose and trehalose formulations, the variation in with temperature could be fitted Vogel-Tammann-Fulcher (VTF) equation. The two formulations exhibited difference sensitivities to temperature. Sucrose formulation was more fragile and exhibited a stronger non-Arrhenius behavior compared to trehalose formulation below glass transition. Both formulations exhibited <2% aggregation at t values <10, where t is the time of storage. Conclusions. Since the relaxation times for sucrose and trehalose formulations at 5°C are on the order of 10⁸ and 10⁶ hrs, it is likely that both formulations would undergo very little (<2%) aggregation in a practical time scale under refrigerated conditions.     

Velocity distributions in the left ventricular outflow tract in patients with valvular aortic stenosis: Effect on the measurement of aortic valve area by using the continuity equation

The cross-sectional velocity distribution in the left ventricularoutflow tract was studied in 40 patients with valvular aorticstenosis. Doppler colour flow mapping and a time-interpolationmethod were used to construct the cross-sectional velocity andtime-velocity integral (TVI) profiles at different levels. Byusing pulsed Doppler, the subaorticflow velocity was sampledfrom the anterior, middle and posterior regions along the diameterof the left ventricular outflow tract (at 0.5 to 1.0 cm proximalto the aortic anulus) in the apical long axis view. Thus, foreach patient, three aortic valve areas were calculated by usingthe continuity equation. Each patient was assigned to one oft/treesubgroups according to the left ventricular ejection fraction(EF): subgroup I with EF25% (n=10), subgroup II with 25%<EF50%(n=17) and subgroup III with EF>50% (n = 13). Velocity distributionsin the three subgroups were compared to each other. Results:(1) The velocity distribution in the left ventricular outflowtract was skewed with the highest velocities and TVIs alongthe anterior wall and septum. The skewness of the velocity distributionwas more pronounced in the apical long axis view than in thefour chamber view (P<0.05). The extent of skewness of theTVI profile was positively correlated to the left ventricularEF both in the long axis view (r=0.63; P<0.001) and in thefour chamber view (r=0–57; P<0.001). (2) Pulsed Dopplersampling from different regions along the diameter produceddifferent TVIs, and therefore yielded significantly differentcalculated aortic valve areas, especially in subgroup III. Due to the skewness of the velocity distribution in the leftventricular outflow tract, location of the pulsed Doppler samplevolume significantly affects the accuracy of aortic valve areacalculation by using the continuity equation, especially inpatients with relatively high left ventricular EF. In patientswith low EF, selection of pulsed Doppler sampling site is lessimportant.     

人工股骨头置换术的应用解剖

目的:为临床人工股骨头置换术人工假体的选择、安装及定位提供可靠的解剖学参数。方法:对250例(左右各125例)正常成人股骨头、股骨颈、大转子与外上髁间距进行观测,并得出转子髁间距与股骨头最大径、股骨头颈前长和股骨头颈后长的相关系数和回归方程。结果:股骨头最大径为4.39±0.31cm,股骨头颈后长为6.89±0.49cm,股骨头颈前长为6.18±0.43cm,大转子与外上髁间距为34.40±1.79cm。结论:采用本文作者提供的方法选择、安装人工假体准确、实用、方便     

Kinetics of d-tubocurarine disposition and pharmacologic response in rats

After bolus intravenous dosing of d-tubocurarine (d-TC) to rats, the twitch heights of the tibialis anterior muscle indirectly stimulated were followed, and its decrease was defined as pharmacologic response of d-TC. The relation between dose and response intensity was found to be well described with Hill's equation. According to a theory proposed by Smolen, Hill's equation was also applicable to the biophase d-TC concentration-response relation; the time courses of the relative biophase d-TC concentration indicated linear kinetics with dose levels 0.15 mg/kg and the occurrence of dose-dependent disposition with 0.30 mg/kg. After bolus i.v. dosing of³H-d-TC, plasma d-TC concentration obeyed a dose-independent two compartment model with doses 0.15mg/kg, but not with 0.30 mg/kg. This finding matched the above estimated with pharmacologic data. The active metabolite was not found in plasma and urine. The extent of d-TC plasma protein binding was independent of the wide range of plasma levels and its mean (±SD) value was 30.5 (±3.8). Plasma d-TC levels and pharmacologie response intensity were well correlated by Hill's equation and a three compartment model (the general two and the biophase compartments) in the dose range 0.15 mg/kg.This work was presented at the First Japanese-American Symposium on Pharmacokinetics and Biopharmaceutics, Tokyo, July 1981, which was held in memory of Dr. Sidney Riegelman.     

On the solution to the Michaelis-Menten equation

An explicit solution to the Michaelis-Menten differential equation is presented. Instead of involving the exponential function, the solution involves another simple function. A table for this function is presented.     

局部药代动力学的药物浓度时空方程初探

目的 建立局部植入给药的药物浓度时空方程。方法 将局部药物浓度时空方程构建为空间分布函数和时间分布函数(药物浓度经时方程)的积函数。并以加权平均及多元分析的数学手段予以证明及推导。结果 四维时空的局部植入给药的药物浓度时空方程的通式为：C(t，X，Y，Z)＝F(X，Y，Z)．C(t)，F(X，Y，Z)＝B0 B1X B2Y B3Z B4r3 B5r2 B6r,C(t)＝A1e^-Ket A2e^-Ket A3c^-Ket.。两维变量的简化的药物浓度时空方程为：C(t,ρ)＝F(ρ)．C(t)F(ρ)＝D0 D1ρ D2ρ2 D3ρ3，C(t)同上。结论 推导基本合理，并在初步的动物试验探索中得以验证。理论有较好科研价值，有助于揭示局部给药的药代动力学规律。