Catalog of intravascular contrast media

The ionic intravascular contrast media formulations now commercially available are presented, along with those new formulations, nonionic and ionic, that have a significant reduced osmolality compared with those previously available.     

Respiratory syncytial virus infection enhances the response to laryngeal chemostimulation and inhibits arousal from sleep in young lambs*

To evaluate the effect of respiratory syncytial virus (RSV) infection on the response to laryngeal chemostimulation (LCS) with water, five lambs were inoculated with human RSV and three lambs were given control media at an age of 3-5 days. During RSV infection, LCS resulted in increased inhibition of minute ventilation and delayed recovery of regular breathing. Sleep further increased the response, and arousal was less likely to occur in active sleep. Two of the five infected lambs needed resuscitation after LCS when arousal was absent. Histological studies showed bronchiolitis and pneumonitis. Laryngeal tastebud morphology was unchanged at 8 days after inoculation. However, infected lambs had disrupted tastebuds 4-6 weeks after infection. Failure to arouse and to terminate reflex apnea may play a role in the pathogenesis of the sudden infant death syndrome associated with respiratory tract infection.     

Screening tests for blood donors presumed to have transmitted the acquired immunodeficiency syndrome

We investigated 18 sets of blood donors from 12 to 50 months after they donated blood to recipients who subsequently developed the acquired immunodeficiency syndrome (AIDS). Within each donor set, only one donor was suspected of having transmitted the disease (ie, member of an AIDS risk group). The other donors (n = 189) were not risk group members and served as controls. A number of laboratory tests distinguished suspected from nonsuspected donors, including determination of T helper/T suppressor cell ratio, antibody to hepatitis B core antigen, and immune complexes, but none of these was as sensitive and specific as tests for antibody to the human retrovirus, HTLV-III/LAV.     

Characterization of nonlymphoid cells derived from rat peripheral lymph

Mesenteric lymphadenectomy in rats is followed by union of peripheral and central lymphatics, allowing the collection of intestine-derived peripheral lymph cells via the thoracic duct for several days. These cells include a proportion of nonlymphoid cells (NLC) that show irregular and heterogeneous surface morphology including long pseudopodia and veils. They stain variably for nonspecific esterase and acid phosphatase and are ATPase-positive. Their nuclei are irregular and some contain cytoplasmic inclusions, some of which show peroxidase activity and/or contain DNA. NLC have a range of densitites generally lower than that of lymphocytes. Freshly collected NLC express the leukocyte-common antigen (defined by monoclonal antibody MRC Ox 1) and Ia antigens (I-A and I-E subregion products defined by monoclonal antibodies) but they show a relative lack of other surface markers normally found on rat B or T lymphocytes (W3/13, W3/25, MRC Ox 12 (sIg), MRC Ox 19) or rat macrophages (FcR, C’R, mannose R, W3/25). In general NLC are only weakly adherent to glass or plastic. Although a subpopulation of NLC appear to have had a phagocytic past, freshly collected NLC fail to phagocytose a variety of test particles in vitro. NLC also appear incapable of pinocytosis in vitro. This heterogeneity may represent distinct subpopulations of NLC or different stages in the development of a single cell lineage. Direct cannulation of mesenteric lacteals shows that the majority of NLC are derived from the small intestine and their precursors appear to be present both in lamina propria and Peyer's patches. Kinetic studies, following irradiation or intravenous tritiated thymidine, show that the majority of NLC turn over rapidly in the intestine with a modal time of 3-5 d. Studies with bone marrow chimeras show that they are derived from a rapidly dividing precursor present in normal bone marrow. NLC occur at very low frequencies in normal thoracic duct lymph at all times following cannulation. The evidence presented suggests that NLC closely resemble mouse lymphoid dendritic cells. This conclusion is supported by evidence already obtained showing that NLC are potent stimulators of the semi-allogeneic rat primary mixed leukocyte reaction. In addition to the ceils resembling dendritic cells rare monocytoid cells are found in thoracic duct lymph of lymphadenectomized specific pathogen-free rats. The proportion of these cells increases greatly when the animals are conventionally housed. It seems probable that the physiological function of NLC is to act as accessory cells in the lymph nodes to which they normally drain. Methods for enriching NLC and thus facilitating analysis of their functions are discussed.     

Adhesiveness of the free surface of a human endometrial monolayer for trophoblast as related to actin cytoskeleton

Adhesiveness of the apical (free) plasma membrane of uterine epithelial cells for trophoblast is essential for the process of human embryo implantation. As epithelial cells are normally repellent, i.e. apically non-adhesive, we argue that a remodelling of the epithelial organization from a polarized to a non-polarized phenotype might prepare the apical pole for cell-cell adhesion during the so-called receptive phase. To identify details of apical adhesiveness we examined human epithelial RL95-2 cells (RL cells) which, in contrast to other cell lines, allow trophoblast to adhere to their apical plasma membrane. To determine whether the cytoskeletal structure is functionally critical for adhesiveness for trophoblast, RL cells were treated with actin depolymerizing cytochalasin D, i.e. 0.4 microM for 120 min. Changes in adhesiveness for trophoblast were monitored with a centrifugal force-based adhesion assay. Moreover, ultrastructural features, organization of the actin network and expression of integrins, i.e. alpha 6, beta 1, beta 4, were studied using electron microscopy, confocal laser scanning microscopy and cell surface immunogold-labelling techniques. Changes in transmission of mechanical signals via integrins into uterine cells were examined using a magnetic drag force device, thereby monitoring intracellular calcium responses. The results suggest that adhesiveness of the free surface of RL cells for human trophoblast requires an intact but non-polarized actin cytoskeleton, apically localized integrins linked to actin, and calcium signalling originating at the free surface.      

A prospective double-blind,placebo-controlled study of thalidomide sensory symptoms in an elderly population with age-related macular degeneration

We aimed to determine the incidence of sensory symptoms (SS) that complicate thalidomide treatment of patients with age-related macular degeneration. In a double-blind prospective study, 38 patients were randomized to receive either thalidomide (100 mg twice per day) or placebo for 1 year. They were then followed for another year off drug. The SS (numbness, tingling, pins and needles) occurred in nine patients who took thalidomide (9/18; 50%) and in four who took placebo (4/20; 20%). Symptom severity was correlated with the time of onset, but not with cumulative dose. Five patients partially improved when the thalidomide was withdrawn, and three patients developed tremor with the neuropathy. The SS occurred shortly after thalidomide was introduced and we concluded that older patients with macular degeneration should be carefully screened for risk factors of peripheral neuropathy before thalidomide is used in their treatment.     

Estimating the risk of gestational diabetes mellitus: a clinical prediction model based on patient characteristics and medical history

Objective  To develop a clinical prediction rule that can help the clinician to identify women at high and low risk for gestational diabetes mellitus (GDM) early in pregnancy in order to improve the efficiency of GDM screening.
Design  We used data from a prospective cohort study to develop the clinical prediction rule.
Setting  The original cohort study was conducted in a university hospital in the Netherlands.
Population  Nine hundred and ninety-five consecutive pregnant women underwent screening for GDM.
Methods  Using multiple logistic regression analysis, we constructed a model to estimate the probability of development of GDM from the medical history and patient characteristics. Receiver operating characteristics analysis and calibration were used to assess the accuracy of the model.
Main outcome measure  The development of a clinical prediction rule for GDM. We also evaluated the potential of the prediction rule to improve the efficiency of GDM screening.
Results  The probability of the development of GDM could be predicted from the ethnicity, family history, history of GDM and body mass index. The model had an area under the receiver operating characteristic curve of 0.77 (95% CI 0.69–0.85) and calibration was good (Hosmer and Lemeshow test statistic, P  = 0.25). If an oral glucose tolerance test was performed in all women with a predicted probability of 2% or more, 43% of all women would be tested and 75% of the women with GDM would be identified.
Conclusions  The use of a clinical prediction model is an accurate method to identify women at increased risk for GDM, and could be used to select women for additional testing for GDM.     

高效液相色谱法测定醋氯芬酸缓释片的含量

目的：建立了高效液相色谱法测定醋氯芬酸缓释片的含量。方法：采用Zorbax SB-C18色谱柱,以乙腈－四氢呋喃－冰醋酸（25：25：50,用1．0mol/L的NaOH高pH3.5）为流动相,流速为1.0ml/min,以对羟基联苯为内标物,检测波长为275nm,结果：醋 芬酸在10．2－50．1ug/ml范围内呈良好线性（r=0.9993),平均回收率为100．3％,RSD为0．45％,结论：本法可用于该片剂的测定,操作简便,结果准确。