可吸收内固定治疗松质骨骨折22例

目的 总结可吸收内固定材料自身增强聚丙交脂（ＳＲ－ＰＬＬＡ）的临床应用体会。方法 采用波兰进口ＳＲ－ＰＬＬＡ螺钉、棒、线治疗四肢松质骨骨折２２例,随访摄片观察骨折愈合情况,检查关节活动功能。结果 术后有两侧出现并发症,一例局部少量积液,经２次穿刺抽液加压包扎痊愈;一例患者过早去除石膏功能锻炼,螺钉松动滑出,经手术复位石膏外固定治愈,无感染或过敏等情况发生。结论 掌握可吸收材料的生物力学特点,并选择适当的病例,可以最大限度地发挥可吸收内固定材料的优势。     

北京市通州区产妇泌乳启动延迟发生情况及相关影响因素研究

目的 探讨北京市通州地区产妇泌乳启动延迟发生情况及相关影响因素,为提高母乳喂养率提供科学依据。方法 以2019年3月至2021年2月在北京市通州区妇幼保健院分娩的产妇为研究对象,由经过统一培训并考核合格的护理人员随访其泌乳情况并通过问卷收集孕妇相关资料。采用描述性分析方法对产妇泌乳延迟发生情况进行分析,并采用单、多因素分析方法对泌乳延迟发生影响因素进行分析。结果 共纳入2 109名产妇进行研究,产妇年龄20~48岁,以35~48岁居多,占54.10%。泌乳启动正常者1 387人,占65.8%,泌乳启动中位时间为50.65(19.33,70.14)h。泌乳启动延迟者722例,占34.2%。二分类Logistic回归分析结果显示,年龄≥35岁(OR=1.278)、孕期增重过多(OR=1.992)、初产妇(OR=1.243)、妊娠期糖尿病(OR=1.459)、妊娠期高血压疾病(OR=3.314)、剖宫产(OR=1.584)是产妇泌乳启动延迟发生的危险因素。结论 北京市通州区产妇泌乳启动延迟发生率较高,高龄、孕期增重过多、初产妇、妊娠期糖尿病、妊娠期高血压疾病、剖宫产均是产妇泌乳启动延迟发生的危险因素,医护人员应当对于上述类型产妇予以重视,及时关注治疗,以期改善产妇泌乳启动延迟情况。     

Formation of extra digits in the interdigital spaces of the chick leg bud is not preceded by changes in the expression of the Msx and Hoxd genes

By in situ hybridization we studied the expression patterns of Msx and Hoxd genes during the late development of the chick leg autopodium (foot) and compared them to patterns during the experimental development of interdigital extra digits. Extra digits are induced in the third interdigital space after various experimental manipulations, such as transient isolation of the interdigit, or removal of the interdigital marginal ectoderm and mesoderm. Msx1 and Msx2 are normally expressed in the interdigital tissue programmed to die. Our experiment changes the fate of the interdigital tissue from cell death to chondrogenesis and provides a good model for studying Msx involvement in defining areas of programmed cell death. Among the proposed roles for Hoxd genes is their involvement in the specification of digit identity early in development. The induction of extra digits allows us to examine whether this new morphogenetic commitment of the interdigital tissue involves changes in the domains of expression of Hoxd genes. Our results show that extra digits develop without a previous modification of the normal pattern of expression of Msx or Hoxd genes. This observation does not support the correlation between the expression of Msx genes and programmed cell death and suggests a role for these genes in maintaining the interdigital tissue in an undifferentiated state. Our results show that an increased number of digits can be formed without modifications in the pattern of expression of the 5-located Hoxd genes and suggest the existence of latent or residual digit organization mechanisms past the time when digits are normally determined, independent of Hoxd gene expression.     

颈椎不同位置时椎管矢状径及截面积的解剖研究

为观察坐位颈椎不同位置时椎管内结构的变化,解剖颈椎标本８具。用灌石蜡的方法测量颈椎矢状径及截面积的变化。结果：颈椎轻度屈曲时,椎间盘、黄韧带、椎板、硬膜、脊髓的形态与位置发生变化,但对椎管容积影响不大,中立位和自然屈颈位时椎管矢状径和椎管截面积两者均无明显差异（ｐ＞０．０５）。提示：颈椎后路椎板成形椎管扩大手术时,坐位是值得推荐的一种体位。     

Mucoadhesion of Latexes. I. Analytical Methods and Kinetic Studies

A Fourier transform infrared spectroscopy/attenuated total reflection technique for direct quantification of adsorbed poly(styrene) latexes on rat intestinal mucosa was developed for deposited latex amounts up to 1.5 g/m². The method agreed well with another dosage assay of adsorbed particles by turbidimetry after denaturation of the mucus. Adsorption kinetics were made under static conditions at latex concentrations of 4 g/L in physiological saline. Ninety percent of equilibrium was reached after 10 min for a particle size of 230 nm, 20 min for a size of 320 nm, and 30 min for a size of 670 nm. The plateaus were between 0.6 and 0.9 g/m² (adsorbed mass per apparent surface of mucosa). The first phase of the kinetics was theoretically approached by a diffusion model in the suspension medium. Mucosa from rat jejunum and ileum could be considered as a homogeneous biological model for latex adsorption.     

Sex selection may be inadvertently performed in in-vitro fertilization--embryo transfer programmes

The present study aims to ascertain whether sex selection maybe inadvertently performed in human in-vitro fertilization (IVF)and embryo transfer (IVF-embryo transfer) programmes when selectingfor high quality embryos (those with the fastest cleaving ratesand/or the best morphology) at the fresh transfer cycle. Allpatients entering into the study were treated with gonadotrophinsafter pituitary suppression with gonadotrophin-releasing hormoneagonists (GnRHa) and had intrauterine embryo transfer on day2 post-insemination. These patients were retrospectively dividedinto three groups according to whether the difference in meannumber of cells between embryos transferred and all embryosavailable for transfer in a given cycle was less than (negativeselection), equal to (no selection) or greater (positive selection)than zero. In cycles resulting in singleton births, the sexratio of the resulting babies was significantly (P 0.005) shiftedtoward the female (88.8%) and to the male (90.0%) in the negativeand positive selection groups respectively. No shift in sexratio was observed in cycles resulting in multiple births. Maternalage was another independent factor affecting sex ratio at birth.Sex ratio was significantly (P 0.05) skewed in favour of males(62.7%) and females (71.4%) in women <35 and 235 years ofage respectively. Maternal age, number of embryos transferredand the event of selecting or not selecting the slowest cleavingembryos for transfer were entered automatically in a three-groupdiscriminant model for distinguishing cycles resulting in onlyboys, both boys and girls, and only girls. These data suggestthat (i) sex selection may be inadvertently performed in IVF-embryotransfer programmes when selecting for high quality embryosat the fresh transfer cycles; (ii) human endometria may be favourable,indifferent or hostile to either fast cleaving or slow cleavingembryos depending on maternal age; and (iii) ‘natural’sex selection may be performed for social, psychological ormedical reasons.     

An immunocytochemistry study comparing the occurrence of neuroactive substances in the nervous system of cercariae and metacercariae of the eye flukeDiplostomum spathaceum

The nervous system of two larval stages (cercariae, metacercariae) of eye flukeDiplostomum spathaceum was investigated immunocytochemically by the application of antisera to the amino acid glutamate and to neuropeptides isolated from invertebrates (Mollusca) and from vertebrates to whole-mount preparations. In cercariae, positive immunoreactivity (IR) was observed with antisera raised against Catch-relaxing peptide (CARP), FMRFamide, -caudodorsal cell peptide (-CDCP), substance P, vasotocin, and vasopressin. In metacercariae, in addition to positive staining with these antisera, the ones raised against glutamate, APGWamide, caudodorsal cell hormone I (CDCH-I), and small cardiac peptide B (SCP_B) also gave positive IR in the nervous system. In the two larval stages the most extensive pattern of IR was observed with anti-FMRFamide and anti-CARP. In the nervous system of metacercariae the same immunoreactive neurosubstances appeared to be present as in that of cercariae. The increase in the variety of immunoreactive neurosubstances in the more complex nervous system of metacercariae is discussed in relation to parasite development and to host adaptation.     

Crystal Structure of 2-Debenzoyl, 2-Acetoxy Paclitaxel (Taxol®): Conformation of the Paclitaxel Side-Chain

Crystals of the C2-acetate analog of paclitaxel, grown from a mixture of isopropyl alcohol and methanol, belong to the space group P2_l with a = 9.058(3), b = 18.306(5), c = 15.043(1) , = 97.09(1)°, Z = 2, V = 2475.1(9)³, D _calc = 1.269 gcm^–3 and µ = 0.75 cm^–1. The structure was determined by direct methods and refined to R(F) = 0.054 and wR(F) = 0.057 for 605 variables and 3496 observed reflections. The paclitaxel side chain possesses a conformation similar to that observed in the crystal structure of docetaxel (Taxotere^®). A three dimensional network of hydrogen bonds is formed through solvent molecules and stabilizes the crystal lattice.     

Antibiotic C3368-A,a fungus-derived nucleoside transport inhibitor,potentiates the activity of antitumor drugs

Antibiotic C3368-A (CA) is produced by a fungus strain from a soil sample collected in Antarctica. CA markedly inhibited radiolabeled thymidine and uridine transport in mouse Ehrlich carcinoma cells, its 50% inhibitory concentration (IC₅₀) being 4.6 and 7.7 M, respectively. In clonogenic assay, CA displayed a synergistic effect with methotrexate (MTX), mitomycin C (MMC), 5-fluorouracil (5FU), and Adriamycin (ADR) against human oral epidermoid carcinoma KB cells. CA also markedly enhanced the inhibitory effect of 5FU and ADR on the proliferation of human hepatoma BEL-7402 cells as determined by thep-nitrophenyl-N-acetyl--d-glucosaminide (NAG) enzyme-reaction assay. 5FU or ADR cytotoxicity was not augmented by CA in human fetal lung 2BS cells. In vivo, CA significantly potentiated the inhibitory effect of MMC against colon carcinoma 26 in mice. No significant augmentation of toxicity by the combination was found in treated mice. The results suggest that CA, the newly found nucleoside-tranport inhibitor, may be useful in potentiation of the effect of antitumor drugs.     

Laser Doppler velocimetry in retinal arteries of infants

The present study was conducted to assess the feasibility of laser Doppler velocimetry in young infants, as a prelude to ultimately undertaking such measurements in premature infants. A portable, unidirectional laser Doppler velocimeter was developed based on a Kowa RC-2 hand-held fundus camera. Six infants between 1 and 21 weeks of age were studied. Relative red blood cell velocity (f_max) at the centre of retinal arteries was measured over approximately 10 heart cycles. A pulsatility parameter (P=1–f_max.dia/f_max.sys), a summary index of vascular status, was determined from the average diastolic and systolic values of f_max. Velocity waveforms were obtained in four of the six infants. Arterial pulsatility for the group was 0.63±0.13. Precise non-invasive measurement of arterial red blood cell velocity waveforms in young infants was achieved. The high signal-to-noise ratio and temporal resolution of this data suggest that relative measurements of retinal blood flow may permit assessment of haemodynamic changes in premature infants.