Early cartilage degradation in cationic immune complex arthritis in mice: relative role of interleukin 1, the polymorphonuclear cell (PMN) and PMN elastase.

OBJECTIVE: To determine the relative role of interleukin 1 (IL-1), polymorphonuclear cell (PMN) and PMN elastase in early cartilage degradation in cationic immune complex mediated arthritis (ICA) in mice. ICA is characterized by early production of IL-1, pronounced influx of PMN and marked cartilage degradation within one day. METHODS: IL-1 was neutralized by polyclonal antibodies against IL-1 alpha and IL-1 beta, given shortly before arthritis induction. The role of PMN was studied in mice made neutropenic by whole body irradiation (750 rad). The effect of elastase was examined in beige mice with PMN deficient in elastase. RESULTS: Neutralizing IL-1 during arthritis induction reduced PMN infiltration significantly and diminished cartilage degradation by 50%. In neutropenic mice, joint inflammation was virtually absent and cartilage proteoglycan loss was abolished. Finally arthritis was induced in beige mice. Although elastase appeared to be the dominant cartilage degrading factor in vitro, we found no difference in cartilage degradation in arthritic joints of beige mice and their normal littermates. CONCLUSIONS: Our data suggest that IL-1 is a crucial factor regulating PMN influx in ICA. The PMN are involved in cartilage degradation but a direct destructive role (e.g., by elastase) seems unlikely.

Intercomparison of calibration procedures for Ir-192 HDR sources in The Netherlands and Belgium.

Thirteen radiotherapy departments in The Netherlands and Belgium participated in an intercomparison of the calibration procedures in use for the quality control of iridium-192 high dose rate sources. A measuring device from 1 of the departments was taken to the 12 other participants, where 1-3 sources were measured by both the local and the visiting physicist's team. Also, 1 192Ir HDR reference source was taken to 7 other--Dutch--departments to serve as a stability check of the measuring device. The results of the local calibration were compared with the values obtained by the visiting team. A mean deviation of +1.3% was found in 19 observations, with values ranging from -0.4% to +3.0%. In total, 16 sources were checked. The measured reference air kerma rate of the available sources was compared with the value stated on the source calibration certificate: the values on the certificate were on the average +1.8% higher than the measured values, ranging from -4.2% to +6.8%. In 1 instance the reference source was also measured by The Netherlands Measurements Institute (NMI), the national standards laboratory in The Netherlands. A good agreement was found between the NMI calibration and the reference air kerma rate determined with the measuring device used in this project.

Clinical and physical aspects of total body irradiation for bone marrow transplantation in Nijmegen.

Eighty-nine patients were transplanted with allogeneic bone marrow after a standard conditioning regimen consisting of cyclophosphamide and fractionated total body irradiation (2 x 4.5 Gy) with average dose rates of 4.1 and 12.3 cGy/min, respectively. The average rectum and lung dose was 9.2 +/- 0.45 and 7.5 +/- 0.78 Gy. In vivo dosimetry was performed in 71 patients irradiated with 18 MV X-rays from left and right lateral. Forty-three patients (48%) died. After increasing the dose rate the incidence of interstitial pneumonitis increased, but the number of relapses decreased.

A computerized method for rapid quantification of gallbladder volume from real-time sonograms.

A computerized method that requires only 1-2 minutes to quantify gallbladder volume from real-time sonograms is described. This time is considerably shorter than that required using the hand-calculation method. There was a highly significant correlation between gallbladder volumes calculated by computer and hand (r = 0.97; P less than .001).

Four years experience with a mercury shielded irregular field system (MSIFS).

A mercury shielded irregular field system (MSIFS) has been in use in our department since January 1979. The system is described and illustrated. Experience in treating 225 patients demonstrated that the system is accurate and reproducible. The system offers a choice of shielding efficiency in a transmission range from 100 to 3.5% for 18 MV photons. Routine measurements of mercury vapor concentration in the treatment room showed values below 0.02 mg Hg/m3 air. (The maximum acceptable concentration in The Netherlands is 0.05 mg Hg/m3 air.) It is concluded that the system is cost-effective, easy to use, and flexible and safe.