Bacterial clearance and cytokine profiles in a murine model of postsurgical nosocomial pneumonia

The development of a nosocomial pneumonia is facilitated by alterations in host innate pulmonary antibacterial defenses following surgical trauma, which can result in decreased pulmonary bacterial clearance and increased morbidity and mortality. In a murine model of postoperative nosocomial infection, surgical stress (laparotomy) decreased Escherichia coli clearance from the lungs of animals that underwent surgery. Consistent with previous studies, (i) pulmonary levels of tumor necrosis factor alpha at 6 h and of interleukin-1beta (IL-1beta), IL-6, and gamma interferon (IFN-gamma) at 24 h post-bacterial infection (PBI) were decreased in animals that underwent laparotomy 24 h prior to E. coli infection (LAP/E. coli) compared to animals that received E. coli only; (ii) KC and macrophage inhibitory protein 2 were elevated at 6 h PBI in LAP/E. coli animals compared to E. coli-only animals; however, at 24 h PBI, levels were higher in the E. coli-only group; (iii) at 24 h PBI, monocyte chemoattractant protein 1 was lower in the LAP/E. coli group compared to the E. coli-only group; (iv) IL-10 levels were unaffected at all time points evaluated; and (v) the total number of neutrophils present in the lungs of LAP/E. coli animals at 6 h PBI was decreased in comparison to that in E. coli-only animals, resulting in decreased bacterial clearance and increased mortality in LAP/E. coli animals by 24 h PBI. Similar changes in cytokine profiles, pulmonary bacterial clearance, and mortality were consistent with reported findings in patients following surgical trauma. This model, therefore, provides a clinically relevant system in which the molecular and cellular mechanisms that lead to the development of nosocomial pneumonia can be further explored.     

A longitudinal study of maternal serum inhibin-A, inhibin-B, activin-A, activin-AB, pro-alphaC and follistatin during pregnancy

Maternal serum concentrations of inhibin-A, inhibin-B, activin-A, activin-AB, pro-alphaC-related inhibin forms, total follistatin, steroids and gonadotrophins were measured longitudinally in six normal singleton pregnancies. Maternal venous blood was collected randomly during a spontaneous follicular phase prior to donor insemination, at 5, 7, 9, 11, 16, 20, 24, 28, 32 and 36 weeks after the first missed menses and in the early puerperium. Steroid and gonadotrophin profiles conformed to previous reports. While at week 5 of gestation inhibin-A, activin-A and follistatin concentrations were similar to those at the follicular phase, all three increased progressively (P < 0.001) to maximal concentrations in week 36: approximately 48-fold (3740 +/- 1349 ng inhibin-A/ml), approximately 22-fold (6109 +/- 1443 ng activin-A/ml) and approximately 10-fold (3563 +/- 418 ng follistatin/ml) higher. Pro- alphaC concentrations reached a maximum in weeks 5 (approximately 5- fold, P < 0.001) and 36 (1027 +/- 174 pg/ml, P < 0.01). Inhibin-B (71 +/- 23 pg/ml prior to pregnancy) was undetectable (<12 pg/ml) between week 5-16 of gestation but increased slightly in the third trimester (26 +/- 7 pg/ml in week 36). Activin-AB was undetectable throughout pregnancy. Post-partum concentrations of inhibin-A (41 +/- 12 ng/ml), inhibin-B (<12 pg/ml), activin-A (950 +/- 149 pg/ml), pro-alphaC (128 +/- 22 pg/ml) and follistatin (990 +/- 79 ng/ml) were substantially lower than at week 36 of gestation. The activin-A:follistatin ratio increased from 0.5 in week 5 to 1.8 in week 36, suggesting that more free activin-A is available in the maternal circulation during late pregnancy.      

Placental Thrombosis and Fetal Loss After Passive Transfer of Mouse Lupus Monoclonal or Human Polyclonal Anti-Cardiolipin Antibodies in Pregnant Naive BALB/c Mice

In the present study we evaluated the effect of passive transfer of a mouse monoclonal (CAM) or a human polyclonal anti-cardiolipin IgG on pregnancy outcome in BALB/c mice. The mice were immunized through the tail vein immediately after mating with 10 μg of monoclonal or polyclonal anti-cardiolipin antibodies. Two other groups of mice were given a mouse irrelevant monoclonal antibody or normal human polyclonal IgG respectively, at the same dose. In mice immunized with monoclonal or polyclonal anti-cardiolipin antibody we observed a significant increase in the number of fetal resorptions and a significant reduction of the mean weights of the embryos and the placentas. In mice immunized with CAM we also found a significant decrease in the number of healthy pups, while mice infused with human aCL antibody expressed a significant reduction in the fecundity rate. The histological examination showed widespread thrombosis and necrosis in the placentas derived from the mice immunized with the anti-cardiolipin antibodies. The model supports a possible direct pathogenetic effect of anti-phospholipid antibodies in recurrent fetal loss and points out that thrombotic events at placental level can be instrumental in the pathogenesis of the obstetric complications.     

General practitioners and clinical guidelines: a survey of knowledge, use and beliefs.

BACKGROUND: Clinical practice guidelines are being developed for a variety of reasons. To date, there has been little investigation of the perspectives of those who are recommended to use them. AIM: The survey reported here set out to investigate how familiar general practitioners are with a range of published guidelines, to assess whether they have used them, and to describe their attitudes to the guidelines and the methods of implementing them. METHOD: A postal questionnaire was sent to a random sample of 559 general practitioners in the North and Yorkshire region in March 1995. Questions were organized around the topics of: knowledge; use; practice change; beliefs; pressure felt to use the guidelines; and methods of implementation. Basic classificatory data on gender; year of qualification; partnership and fundholding status were also collected. RESULTS: Replies were received from 300 doctors (54%). Knowledge and use of the three selected guidelines varied, but was generally towards the 'high' end of the scale. Doctors showed a high degree of homogeneity in their attitudes to guidelines, which were generally positive. Only single-handed practitioners varied from this pattern of responses. Most of the pressure to use the guidelines was felt to come from the Department of Health, and the least pressure from patients. Doctors felt that the methods of implementation that involved them in educational events and discussion with colleagues were most likely to have an impact on them. CONCLUSION: General practitioners are receptive to guideline initiatives, and their views are in line with existing or proposed implementation strategies. More investigation of the concept of 'use' is needed.     

Psychological stress, ego defenses, and cortisol production in children hospitalized for elective surgery.

This study was designed to investigate the relationship between the effectiveness of coping mechanisms and physiological indicators of distress in children faced with the experience of hospitalization and surgery. Twenty-five children between the ages of 7 and 11 were studied in the out-patient department, 2 weeks before surgery, and again during their hospital stay. Effectiveness of defenses and defense style was measured by a clinical interview and by the Rorschach test. Cortisol production rates were measured by the analysis of 24-hour urine collections at home and again in the hospital. Ward adjustment was also rated by a ward questionnaire. The results indicated no relationship between defense effectiveness and cortisol production rates in the out-patient department and an inverse relationship between cortisol production and defense effectiveness under the stress of hospitalization. Defense style was found to correlate with coping under stress. Four different groups of children emerged, suggesting four different types of reaction to the hospital experience.     

Entry of genital Chlamydia trachomatis into polarized human epithelial cells.

To study the initial invasion process(es) of genital chlamydiae, a model system consisting of hormonally maintained primary cultures of human endometrial gland epithelial cells (HEGEC), grown in a polarized orientation on collagen-coated filters, was utilized. After Chlamydia trachomatis inoculation of the apical surface of polarized HEGEC, chlamydiae were readily visualized, by transmission electron microscopy, in coated pits and coated vesicles. This was true for HEGEC maintained in physiologic concentrations of estrogen (proliferative phase) and of estrogen plus progesterone (secretory phase), despite the finding that association of chlamydiae with secretory-phase HEGEC is significantly reduced (P = 0.025; A.S. Maslow, C.H. Davis, J. Choong, and P.B. Wyrick, Am. J. Obstet. Gynecol. 159:1006-1014, 1988). In contrast, chlamydiae were rarely observed in the clathrin-associated structures if the HEGEC were cultured on plastic surfaces. The same pattern of coated pit versus noncoated pit entry was reproducible in HeLa cells. The quantity of coated pits associated with isolated membrane sheets derived from HeLa cells, grown on poly-L-lysine-coated cover slips in medium containing the female hormones, was not significantly different as monitored by radiolabeling studies and by laser scanning microscopy. These data suggest that culture conditions which mimic in vivo cellular organization may enhance entry into coated pits for some obligate intracellular pathogens.     

Differentiation of Normal and Malignant Human Squamous Epithelium in Vivo and in Vitro: A Morphologic Study

We would like to thank John Ellis for expert photographic assistance, Mervin Jones and Linda Lovell for expert animal husbandry, and Dr. Dorothy Easty for establishing the cell line LICR-LON-HN-5, without which this study would not have been possible.

We report a light microscopic and ultrastructural analysis of the comparative degrees of differentiation seen in keratinocytes derived from the tongue and epidermis with those of a well-differentiated human squamous carcinoma cell line (LICR-LON-HN5). When growing on plastic substrates, all cultures had a similar morphology, with multilayering and the production of cornified envelopes. When cultured on collagen gels the structure was more organized, with keratohyalin granules and keratin whorl formation in both the normal and the malignant cultures. Normal keratinocytes injected into athymic mice produced epidermal cysts, while cells from the cell line produced well-differentiated squamous cell carcinomas, which were partially solid and partially cystic. The tumor was well organized, with identifiable basal cells, spin-ous cells, keratohyalin granules, and a prominent basal lamina at the stromal/epithelial interface. This model is to be developed for comparative studies between normal and malignant cells, with particular reference to basement membrane production and to investigations of the relative importance of extrinsic and intrinsic factors in the control of squamous differentiation.