挤压综合征救治原则的争议探讨

挤压伤/挤压综合征是突发性自然或人为灾害中（地震、车祸、矿难或战争）最常见的损伤,可继发严重的全身反应,致死致残率极高,救治困难。本文总结近年来国内外地震造成的挤压伤/挤压综合征的发病率、机制、治疗措施及存在问题,以期改进治疗方法与措施,提高生存率及保肢率。     

Accuracy of the Papanicolaou test in screening for and follow-up of cervical cytologic abnormalities: a systematic review

PURPOSE: To evaluate the accuracy of conventional and new methods of Papanicolaou (Pap) testing when used to detect cervical cancer and its precursors. DATA SOURCES: Systematic search of English-language literature through October 1999 using MEDLINE, EMBASE, other computerized databases, and hand searching. STUDY SELECTION: All studies that compared Pap testing (conventional methods, computer screening or rescreening, or monolayer cytology) with a concurrent reference standard (histologic examination, colposcopy, or cytology). DATA EXTRACTION: Two reviewers independently reviewed selection criteria and completed 2 x 2 tables for each study. DATA SYNTHESIS: 94 studies of the conventional Pap test and three studies of monolayer cytology met inclusion criteria. No studies of computerized screening were included. Data were organized by cytologic and histologic thresholds used to define disease. For conventional Pap tests, estimates of sensitivity and specificity varied greatly in individual studies. Methodologic quality and frequency of histologic abnormalities also varied greatly between studies. In the 12 studies with the least biased estimates, sensitivity ranged from 30% to 87% and specificity ranged from 86% to 100%. CONCLUSIONS: Insufficient high-quality data exist to estimate test operating characteristics of new cytologic methods for cervical screening. Future studies of these technologies should apply adequate reference standards. Most studies of the conventional Pap test are severely biased: The best estimates suggest that it is only moderately accurate and does not achieve concurrently high sensitivity and specificity. Cost-effectiveness models of cervical cancer screening should use more conservative estimates of Pap test sensitivity.     

Using questionnaires to ask nurses about working in the community: problems of definition

Given the emphasis on providing services in the community, it is likely that there will be an increase in research into various aspects of the community. It is important that the way in which 'community' is defined in research will provide valid and reliable data and facilitate comparisons with other work on the subject. This paper discusses how the problems of defining the community were approached in a longitudinal study of the careers of people qualifying from the pre-registration diploma course in nursing.     

Pharmaceutical and biotechnological aerosols for cystic fibrosis therapy

This review addresses different aerosol therapies used to treat the underlying cause and symptoms of cystic fibrosis (CF) during the past two decades. A summary of the current methods of aerosol delivery and suggestions that may improve the efficacy of the current treatments are provided.     

Factors affecting the deposition of inhaled porous drug particles

Recent findings indicate that the inhalation of large manufactured porous particles may be particularly effective for drug delivery. In this study, a mathematical model was employed to systematically investigate the effects of particle size, particle density, aerosol polydispersity, and patient ventilatory parameters on deposition patterns of inhaled drugs in healthy human lungs. Aerodynamically similar particles with densities of 0.1, 1.0, and 2.0 g/cm(3) were considered. Particle size distributions were defined with mass median aerodynamic diameters (MMADs) ranging from 1 to 3 microm and geometric standard deviations ranging from 1.5 to 2.5, representing particles in the respirable size range. Breathing rates of 30 and 60 L/min with tidal volumes of 500 to 3000 mL were assumed, simulating shallow to deep breaths from a dry powder inhaler. Particles with a high density and a small geometric diameter had slightly greater deposition fractions than particles that were aerodynamically similar, but had lower density and larger geometric size (typical of manufactured porous particles). This can be explained by the fact that particles with a small geometric diameter deposit primarily by diffusion, which is a function of geometric size but is independent of density. As MMAD increased, the effect of density on deposition was less pronounced because of the decreased efficiency of diffusion for large particles. These data suggest that polydisperse aerosols containing a significant proportion of submicron particles will deposit in the pulmonary airways with greater efficiency than aerodynamically similar aerosols comprised of geometrically larger porous particles.     

Hypertension control: how well are we doing?

BACKGROUND: We compared blood pressure (BP) control in a recent cohort of hypertensive military veterans with BP control in a previous cohort and examined whether hypertension treatment practices, as defined by the frequency of antihypertensive medication dosage increases, have changed over time. METHODS: We abstracted 1999 outpatient chart data including visit type, BP measurements, comorbidities, and medication use for 981 randomly selected hypertensive veterans. We examined overall BP control and control in subgroups with diabetes mellitus and renal disease, and compared results with those of a sample of 800 veterans studied from 1990 to 1995. We also compared the frequency of antihypertensive medication dosage increases in the 2 samples. RESULTS: Mean BPs were significantly lower in 1999. The mean systolic drop was 3.1 mm Hg and reached 13.7 mm Hg for the subgroups with diabetes and renal disease. Even larger decreases were seen in mean diastolic BPs. In 1999, 57% of patients had BP measurements of 140/90 mm Hg or higher, vs 69% of patients in the 1990-1995 study (P<.001). In 1999, the BP control of patients with diabetes was similar to that of patients without diabetes, as 60% of the former had BP measurements of 140/90 mm Hg or higher. Patients with renal disease had better control than those without, however, as only 43% had BP measurements of 140/90 mm Hg or higher. When comparing samples, patients with diabetes, renal disease, or both had better BP control in 1999 than their counterparts in the 1990-1995 study (P<.003 in all cases). In 1999, more medical visits were associated with medication dosage increases than in the 1990-1995 study. CONCLUSIONS: Although overall BP control has improved, BP measurements still exceeded recommended levels in most patients. For patients with diabetes and renal disease BP was much better controlled in the more recent sample. However, BP control of patients with diabetes was similar to that of patients without diabetes, and not in agreement with the guideline-recommended tighter control. Thus, room for improvement remains, especially in this subgroup.     

Lesion response of long-term and recently immigrated resident endoneurial macrophages in peripheral nerve explant cultures from bone marrow chimeric mice

Resident macrophages of the peripheral nervous system have recently been shown to respond rapidly to Wallerian degeneration before the influx of blood-derived macrophages. Because resident endoneurial macrophages are slowly but incompletely exchanged from the blood within 3 months, they could potentially comprise a heterogenous cell population consisting of long-term resident cells and more mobile cells undergoing turnover. We used bone marrow chimeric mice created by transplanting bone marrow from green fluorescent protein-transgenic mice into irradiated wildtype recipients to selectively analyse the response of these two resident macrophage populations to Wallerian degeneration in sciatic nerve explant cultures. In such nerves, recently immigrated macrophages exhibit green fluorescence whereas long-term resident macrophages do not. Studies in cultures from wildtype controls revealed rapid morphological changes of resident macrophages towards a bloated phenotype, a proliferative response resulting in a 3.7-fold increase of macrophage numbers over 2 weeks, and phagocytosis of myelin basic protein-immunoreactive myelin debris. When chimeric mice were analysed, both populations of resident endoneurial macrophages participated in morphological transformation, proliferation and phagocytosis. Quantitative studies revealed a stronger proliferative and phagocytic response in long-term resident endoneurial macrophages compared with recently immigrated macrophages. Our results point towards subtle, but not principal, differences between the two macrophage populations, which might indicate different stages of macrophage differentiation rather than the existence of entirely distinct endoneurial macrophage populations. The results further underline the versatility of resident endoneurial macrophages following peripheral nerve injury, which is reminiscent of the lesion response of microglial cells within the brain.     

Response of macroinvertebrates to copper and zinc in a stream mesocosm

Metal pollution of streams and rivers is recognized as one of the major concerns for management of freshwaters. Macroinvertebrate communities were established within 12 artificial streams and exposed to three replicated concentrations of a metals mixture (copper and zinc) for 34 d. The cumulative criterion units (CCU = sigma[metals]/hardness-adjusted U.S. Environmental Protection Agency [U.S. EPA] 1996 chronic criterion value) of total metals in the low, medium, and high treatments were 2.4, 5.9, and 18 CCUs. Zinc comprised approximately 75% of the CCUs in each of the treatments. Effects on taxa richness and the number of taxa in the orders Ephemeroptera, Plecoptera, and Trichoptera (EPT) were moderate at the high exposure concentration (-23% and -26% respectively, p < 0.05). All of the five major mayfly species showed near extinction, whereas four of the seven caddisflies showed stimulation (up to +121%) and three were reduced (up to -76%). Redundancy analysis for this metal gradient indicated that 94% of the variance in community structure was explained by three quantitative variables: total mayfly abundance, a mollusk (Potamopyrgus antipodarum) abundance, and the number of EPT individuals, indicating that multiple indices do provide improved predictors of metal stress. Most species showed a threshold response relationship, whereas some community indicators showed apparent hormetic responses (e.g., number of mayfly taxa, total taxa, and number of EPT taxa). Model concentration-response relationships with generalized linear models were used to provide threshold of 20% effective concentration values for species and community metrics. Threshold effect values ranged upwards of 1.4 CCUs, indicating that U.S. EPA chronic criteria would be protective of species and community responses.