Epidemiological disaster research: the necessity to include representative samples of the involved disaster workers. Experience from the epidemiological study air disaster Amsterdam-ESADA

OBJECTIVE: To study whether the methods used to select participants in research on prevalence rates of the health effects of exposure to a disaster may cause bias. This study compared background characteristics, disaster exposure, and complaints reported by (1) police officers who participated in an epidemiological study and underwent a medical examination, and (2) police officers who only participated in an epidemiological study. DESIGN AND SETTING: In 2000, an epidemiological study was started to investigate the health status among police officers who were involved in assistance work related to the air disaster in Amsterdam: the epidemiological study air disaster Amsterdam (ESADA). These police officers were personally invited to participate in the epidemiological study and were additionally offered a medical examination, providing them with the opportunity to have their health checked by a medical doctor. PARTICIPANTS: Of the total group of involved police officers who were invited, 834 (70%) participated in the ESADA: 224 (26.9%) only participated in the study, but 610 (73.1%) also underwent the medical examination. MAIN RESULTS: Police officers who underwent a medical examination significantly more often reported one or more musculoskeletal complaints, skin complaints, general or non-specific complaints, had more often experienced an event with potentially traumatic impact, or had performed one or more potentially traumatic tasks. CONCLUSIONS: The methods of selection of participants are important in research on health effects after disasters and can result in an overestimation of some of the effects, on average, by a factor of 1.5 to 2.     

LDL-mediated drug targeting

The possibilities and limitations in using the low-density lipoprotein (LDL) as a carrier for drugs are discussed. LDL, which may be regarded as the natural counterpart of liposomes, possesses a lipid core that may be utilized as a drug reservoir. Unlike most types of liposomes, the endogenous LDL particle is not avidly taken up by the reticuloendothelial system and may persist in the circulation for prolonged times after injection. A well-characterized membrane receptor recognizes LDL, and binding appears to be coupled to uptake and intracellular processing. Since many tumor tissues express a high amount of LDL receptors, there is a rationale for the design of a toxic LDL-cytostatic drug complex. The behavior of LDL in vivo will be discussed and the principles of LDL-mediated targeting to tumor cells will be evaluated. In addition, methods for drug incorporation into LDL will be critically assessed, while evaluation methods will be presented that may set the standards for future research.     

Is the magnetic resonance imaging proton spin-lattice relaxation time a reliable noninvasive parameter of developing liver fibrosis?

During the development of liver fibrosis in rats by an individual dose-titrated CCl4 administration, hepatic proton spin-lattice relaxation time (T1) has been measured in vivo every 2 weeks for 8 weeks. Liver content of collagen, triglycerides and water has been measured biochemically in biopsy material. After 4 weeks of CCl4 treatment, T1 increased significantly and remained at the same level, whereas liver collagen reached its maximum at 8 weeks. It is concluded that, under our experimental conditions, increased hepatic T1 represents drug-induced edema and that hepatic T1 is not a reliable noninvasive parameter for developing liver fibrosis in vivo.     

BLOOD PRESSURE, SALT TASTE AND SODIUM EXCRETION IN RATS EXPOSED PRENATALLY TO HIGH SALT DIET

Blood pressure, sodium excretion and salt taste were examined in Sprague Dawley (SD) and Munich Wistar (MW) rats exposed prenatally to either a high salt (2.3% NaCl w/w) or control diet. There was no significant difference in blood pressure at 2, 6 or 12 months between high salt and control groups in either strain. Similarly there was no significant difference in sodium excretion following a saline load by gavage (150 mmol/l, 1.5% BW). Munich Wistar rats which received high salt diet prenatally exhibited a reduced saline preference when offered a choice between water and 150 mmol/l NaCl as drinking fluid. There was no significant difference in saline preference between Sprague Dawley rats which received the high salt or control diet. Prenatal exposure to high salt diet failed to alter the blood pressure or excretion of a salt load in either SD or MW rats. In MW rats but not SD high salt diet prenatally resulted in a reduced saline preference at 3 months of age.     

Short-term strength and pain changes in total hip arthroplasty patients

The purpose of this study was to report on three case studies of patients that underwent cementless, total hip arthroplasties. The primary emphasis of the study was on short-term changes in pain and strength. The MEED 3000 system was used to obtain bilateral strength measurements for hip abductors (HA), hip flexors (HF), knee extensors (KE), and for straight leg raising (SLR). A 10-point scale was used to assess pain intensity at rest and during each of the muscle strength tests. The postoperative pain was greatest and remained the longest for performing the SLR test. Increases and decreases in the strength of the operative and nonoperative hip tended to parallel one another over time. Throughout the period studied, strength differences between the operative and nonoperative sides for HF, SLR, and HE were large while the differences for HA were relatively small. The significant hip and knee muscle weakness of the total hip patients seems to support the need for a carefully monitored resistive exercise program following discharge from the hospital. J Orthop Sports Phys Ther 1990;12(1):16-23.