大鼠实验性急性胰腺炎时血浆和组织脂质过氧化物的变化

本文观察了大鼠实验性急性胰腺炎时血浆和组织脂质过氧化物(LPO)的动态变化。发病后10h动物血浆LPO即见升高,而血浆淀粉酶水平则开始下降。发病10、20h心、肝、肾、肺组织LPO也有不同程度的升高。这证实了氧自由基在急性胰腺炎病理过程中起一定作用。与用血清淀粉酶水平判断急性胰腺炎的发生、发展这一传统方法相比,血浆LPO更能反映急性胰腺炎后期病变的程度及此时全身器官组织受损的情况。     

Disposition rate of proscillaridin A in man after multiple oral doses

After multiple oral doses, the disposition rate constant (beta) of proscillaridin was studied in 4 young healthy volunteers and 33 elderly patients with congestive heart failure. Glycoside activity in plasma was assayed by the 86Rb-technique. In the volunteers the beta averaged 0.0299 corresponding to a half-life (t 1/2) of 23 h. beta could be determined in 24 patients and was 0.0139 +/- 0.0077 (mean +/- SD). The SD of beta due to biological factors was estimated to be 0.0072. The total variation of beta was 10fold. The mean beta corresponded to a t 1/2 of 49 h with a range from 19 to 209 h. It is concluded that the great variation of beta means difficulty in obtaining adequate plasma levels of proscillaridin and that a rapid elimination of the glycoside cannot be presumed.     

Activities of Proscillaridin A in Thoracic Duct Lymph after Single Oral Doses in Man

Abstract In order to study the possibility that orally administered proscillaridin after absorption is transported by the lymph to the systemic circulation, the concentrations of the glycoside in thoracic duct lymph were analyzed in two patients with thoracic duct drainage. They received the drug as a single oral dose; plasma and lymph concentrations were measured by ⁸⁰Rb-technique. Lymph was collected at various intervals for 24 hrs. The proscillaridin activity in thoracic duct lymph was low and followed closely that in the plasma. During the sampling period, a total of 300 ng and 240 ng, respectively, was recovered in the lymph, corresponding to less than 0.03 %₀ of the administered dose. The results indicate that proscillaridin is not transported by the thoracic duct lymph.     

Lectures in problem-based learning--why, when and how? An example of interactive lecturing that stimulates meaningful learning

Even though opinions differ as to whether lecturing is compatible with problem-based learning (PBL) or not, lectures are still a common form of instruction in PBL curricula. This paper discusses the lecture in the framework of theories of learning in general and the medical problem-based learning tradition in particular. An example of how theories of learning can be implemented in the lecture hall is presented. Theories that underpin PBL as an educational philosophy rather than as a method of instruction are reviewed. A lecture form, organized in introductory, in depth and application lectures, that responds to important factors for stimulating deep processing of knowledge and meaningful learning is discussed. Examples of and practical points about how to renew and restructure lectures in a way that counteracts surface approaches to learning, teacher centering and student passivity are presented. We argue that, with proper awareness of possible drawbacks of the large format, lectures can be used as valuable tools for learning also in a PBL curriculum.     

Psychobiological personality dimensions in two environmental-illness patient groups

The aim of the present study was to investigate the psychobiological personality dimensions in two subgroups of patients with environmental illness (EI). Fifty-nine patients, 34 women and 25 men (aged 32–69 years), were referred for symptoms allegedly caused by abnormal sensitivity to either dental fillings (DF; n=26) or electromagnetic fields (EMF; n=33). For the evaluation of personality, the Swedish 238-item version of the Temperament and Character Inventory (TCI) was used. Compared with a control group, the EMF group scored higher on the temperament dimension Persistence. The DF group scored higher on the TCI subscales Harm Avoidance (fatigability and asthenia) and Self-Directedness (self-acceptance). Women scored higher than men did on the Novelty Seeking and Reward Dependence (RD) dimensions in the DF group and on RD in the control group, indicating an inherited gender difference. No differences were found between men and women in the EMF group. Our results indicate that the high level of persistence found in the EMF group and the high level of fatigability and asthenia in combination with high self-acceptance found in the DF group represent vulnerable personalities. No significant differences were found between the two patient groups, indicating that these groups are quite similar regarding personality. This vulnerability can be expressed as various mental and somatic symptoms, which can be interpreted as EI symptoms by the affected individual.     

The risk of finding focal cancer (less than 3 mm) remains high on re-biopsy of patients with persistently increased prostate specific antigen but the clinical significance is questionable

PURPOSE: We evaluated the significance of focal prostate cancer found in sextant biopsies in men participating in a biennial prostate specific antigen (PSA) based screening program. MATERIALS AND METHODS: In 1995, 10000 men 50 to 65 years old were randomized to biennial screening with PSA testing. Sextant biopsies were recommended when total PSA was 3 ng/ml or greater at screening rounds 1 and 2, and 2.54 ng/ml or greater at subsequent screening rounds. Focal cancer was defined as total a core cancer length of less than 3 mm in the biopsy specimen. Low volume cancer was defined as a total tumor volume of less than 0.5 cm in the radical retropubic prostatectomy specimen. RESULTS: The number of men who underwent biopsy and the number of cancers detected in the 5 possible sets of biopsies were 1725 and 402, 706 and 124, 307 and 36, 103 and 9, and 13 and 0, respectively. The risk of detecting focal cancer was 7.9%, 10.2%, 7.5%, 5.8% and 0%, respectively, but the relative ratio (focal-to-all cancers) increased 34%, 58%, 64%, 67% and, not applicable, respectively. In men with a total core cancer length of less than 10 mm there was no correlation between core cancer length and total tumor volume, as measured in the prostatectomy specimen. Two-thirds of men with a total core cancer length of less than 3 mm had a tumor volume of greater than 0.5 cm, while the risk of low volume cancer was less than 5% only in men with a total core cancer length of greater than 10 mm. CONCLUSIONS: In a repeat PSA based screening program sextant biopsies are of little or no value for predicting tumor volume.     

Risk of fatal industrial accidents and death from other external causes among asphalt workers

Overall, no evidence was found supporting the hypothesis that asphalt workers are at increased risk of fatal industrial or road accidents. Mortality from other external causes did not increase in this population as a whole, but increased risks among short term workers deserve further attention.     

Multiple myeloma and diesel and other occupational exposures in swedish construction workers

We examined the relationships between occupational exposures and the risk of multiple myeloma among male construction workers in Sweden. A total of 446 myeloma subjects were identified among 365,424 male workers followed from 1971 to 1999. Occupational exposure was assessed using a semiquantitative job-exposure matrix, based on a survey carried out by the Construction Industry's Organization for Working Environment, Occupational Safety and Health in Sweden. Rate ratios (RRs) in the exposed groups relative to the unexposed groups were estimated by Poisson regression. We found an increased risk (RR = 1.3, 95% CI 1.04-1.71) among construction workers exposed to diesel exhaust. Adjustment for other occupational exposures did not change this estimate (RR = 1.3, 95% CI 1.00-1.77). However, there was no monotonic increase in risk with estimated level of exposure (RR for low = 1.4, moderate = 1.1, high = 1.4). There was no evidence of increased risk associated with the other occupational exposures among these construction workers, including asbestos, asphalt, cement dust, metal dust, mineral wool, organic solvents, stone dust and wood dust. Occupational exposure to diesel exhaust in the Swedish construction industry may present a small risk of multiple myeloma, but lack of an exposure-response trend tempers our ability to draw clear conclusions.