An improved analysis of experimental data from 125 I hot-line autoradiographs: allowing for the effects of background grains

In this paper we suggest a new statistical method of correcting the results of hot-line experiments for the effects of background sources and we use the new method to reassess the adequacy of three probability distributions proposed in the literature for image spread from line sources. The data are from sources labelled with ¹²⁵I in semi-thin resin sections 0·4-0·8 μm in thickness. The new method reveals that two of the models describe the empirical distributions more closely than earlier analysis had suggested, and it confirms an increasing relationship between half distance of image spread and the thickness of the source. However, it also confirms that considerable ‘inter hot-line’ experimental variation remains, even after background correction. This suggests that multiple experiments are needed to produce reliable estimates of half distance.     

Hypertonicity regulates the function of human neutrophils by modulating chemoattractant receptor signaling and activating mitogen-activated protein kinase p38

Excessive neutrophil activation causes posttraumatic complications, which may be reduced with hypertonic saline (HS) resuscitation. We tested if this is because of modulated neutrophil function by HS. Clinically relevant hypertonicity (10-25 mM) suppressed degranulation and superoxide formation in response to fMLP and blocked the activation of the mitogen activated protein kinases (MAPK) ERK1/2 and p38, but did not affect Ca2+ mobilization. HS did not suppress oxidative burst in response to phorbol myristate acetate (PMA). This indicates that HS suppresses neutrophil function by intercepting signal pathways upstream of or apart from PKC. HS activated p38 by itself and enhanced degranulation in response to PKC activation. This enhancement was reduced by inhibition of p38 with SB203580, suggesting that p38 up-regulation participates in HS-induced enhancements of degranulation. HS had similar effects on the degranulation of cells that were previously stimulated with fMLP, but had no effect on its own, suggesting that HS enhancement of degranulation requires another signal. We conclude that depending on other stimuli, HS can suppress neutrophil activation by intercepting multiple receptor signals or augment degranulation by enhancing p38 signaling. In patients HS resuscitation may reduce posttraumatic complications by preventing neutrophil activation via chemotactic factors released during reperfusion.     

A data model for managing drug therapy within a patient data management system for intensive care units

The major intent of this article was to describe the design principles of the drug-therapy documentation module of the Patient Data Management System (PDMS) ICUData, in routine use at the intensive care unit (ICU) of the Department of Anesthesiology and Intensive Care Medicine at the University Hospital of Giessen, Germany, since February 1999. The new drug management system has been in routine use since March 2000. Until 8 January 2001, 1140 patients have been documented using this approach. It could be demonstrated that it was possible to transform the formerly unstructured text-based documentation into a detailed and structured model. The mediated benefit resulted in the automatic calculation of fluid balance. Further, detailed statistical analyses of therapeutic behavior in drug administration are now possible.     

Early detection of anastomotic leaks after colorectal surgery by measuring endotoxin in the drainage fluid

BACKGROUND/AIMS: Early detection of anastomotic leaks after colorectal anastomosis is essential for adequate intervention to prevent peritonitis. We investigated whether the measurement of endotoxin (LPS) concentrations in the drainage has any value for the early detection of anastomotic leaks. MATERIALS AND METHODS: Twenty two patients with colorectal anastomosis were enrolled in this study, 3 developed clinically established signs of anastomotic leaks and 19 recovered without complications. LPS concentrations in the drainage, the total daily excreted LPS amounts, leukocyte and thrombocyte counts, plasma urea and creatinine, and body temperature were measured for up to 8 days after surgery and tested for their value to detect anastomotic leaks. RESULTS: LPS concentrations in the drainage fluid and daily excreted LPS amounts of patients with anastomotic leaks were significantly higher compared to the group without anastomotic leaks. On the third postoperative day, LPS concentrations ranged from 5270 to 6750 pg/ml in patients with anastomotic leaks and from 1 to 1848 pg/ml in patients without complications. Total daily excreted LPS amounts were 270-675 ng/day in patients with anastomotic leak and 0-92 ng/day in patients without anastomotic leaks. Both LPS-related parameters allowed reliable detection of anastomotic leaks on day 3 after surgery (Student's t-Test, p < 0.0005), while leukocyte and thrombocyte counts, plasma urea and creatinine, and body temperatures of both patient groups were not significantly different at any time (p > 0.05). CONCLUSION: We found that the measurement of LPS concentrations in the drainage and the daily excreted LPS amount could be valuable parameters for the early detection of anastomotic leaks as early as on the third post-operative day.     

Four year''s experience with quality assurance in anesthesiology in Hamburg

50 eyes of 30 Sprague-Dawley rats were subjected to 60 minutes of pressure-induced ischemia, then fixed for light and electron microscopy with no reperfusion, or reperfusion after 30 minutes, 1, 2 or 4 hours, and 1 or 3 days from the time ocular ischemia was relaxed. The TdT-mediated dUTP-biotin nick end labeling (TUNEL) method revealed apoptotic signs at the inner retina as early as 1 hour after reperfusion. However, the incidence of apoptotic signs with the TUNEL method did not accord with the results of electron microscopic examination. During the time after the reperfusion started, especially after more than 4 hours, apoptotic signs became obvious and extended from the inner to the outer retina. These apoptotic findings could be seen with both the TUNEL method and electron microscopy. By 3 days after the reperfusion, necrotic cells in the ganglion cell layer, and the inner and outer nuclear layer became more prominent than apoptotic cells. These results may provide a baseline for therapeutic strategy and the prognosis of ischemia-reperfusion injury in the retina.     

Methodological basis for an autoradiographic demonstration of insulin receptor sites on the surface of whole cells: a study using light- and scanning electron microscopy

An autoradiographic technique is described which allows, on whole cells, the determination of the number of receptor sites which are occupied by ¹²⁵I-insulin according to defined binding conditions. Glutaraldehyde fixation prevents the dissociation of the bound tracer from the receptor, which is the basis for a quantitative correlation between biochemical and autoradiographical data. The homogeneous coating of whole cells with a thin emulsion layer, which was required for these experiments, was achieved by a stripping film technique. An accurate judgment of the coating was possible only with scanning electron microscopic (SEM) techniques. As observed in the SEM, the photographic layer was smooth, uniform and in good contact with the top of the cell. The signal measured in this area was analysed. The majority of the grains also originated from the top side of the cell surface, despite the evidently three-dimensional distribution of the label. As determined in test specimens, 80–85% of the grains originated from 3–4 keV electrons. Due to the short range of these electrons, the grains represent the distribution of the label on the part of the cell surface which is in close contact with the emulsion layer. 15–20% of the grains originated from β-decays with higher energies and add partially to the background. According to these data a determination of the number of receptor sites per unit area of plasma membrane (receptor density) is possible in the surface area of the cell top. Both light microscopy (LM) and SEM were used to analyse autoradiographs. LM analysis is possible in principle but the analytical facilities of SEM are yet superior for the identification of silver grains. The registration of the grains is further facilitated in SEM because of the very large depth of focus.     

Hypertonic saline resuscitation reduces neutrophil margination by suppressing neutrophil L selectin expression

Hypertonic saline (HS) reduces hemorrhage-induced lung injury by suppressing the neutrophil oxidative burst and reducing lung neutrophil influx. This study investigated whether this is caused by the effects of HS on endothelial adhesion molecule expression, the production of chemoattractants in the lung, or a direct effect of HS on neutrophil selectin expression. METHODS: BALB/c mice were made to hemorrhage to 40 mm Hg for 1 hour and resuscitated with shed blood and either 4 mL/kg 7.5% HS or two times the shed blood volume of lactated Ringer's solution (LRS). Neutrophil L selectin expression was determined by flow cytometry, total neutrophil counts were obtained by differential staining, and pulmonary endothelial P and E selectin expression was evaluated by immunohistochemistry. Chemoattractants in lung lavages were determined with a modified Boyden chamber migration assay. RESULTS: Chemotactic activity of lavage fluid of HS-treated animals was not significantly different from that of LRS-treated animals, and endothelial P and E selectin expression was not altered by HS resuscitation. Neutrophils of HS-treated animals, however, expressed significantly less L selectin than those of LRS-treated mice. Concomitantly, circulating neutrophil counts of LRS-treated animals were significantly decreased compared with those of HS-treated mice. CONCLUSION: HS had little effect on endothelial selectin expression and chemoattractant production in the lung. HS significantly decreased neutrophil L selectin expression, however. This suggests that HS resuscitation may reduce lung injury by preventing neutrophil L selectin expression and endothelial adhesion.     

Lyocell纤维的阳离子化

介绍了Ｌｙｏｃｅｌｌ纤维和织物的改法方法。这种改性方法,能使纤维素纤维的染色用阴离子型羊毛染料（酸性和反应性染料）,在５ｍｉｎ的短时间内和温和的染色条件下使带整个截面均匀染色。