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Biomedical subjects

P Timm

Publications and source records attributed to P Timm.

3 recordsLinked to original sources
PubMed1999

Ozone-induced airway inflammatory changes differ between individuals and are reproducible.

To study whether the individual inflammatory response to ozone was reproducible, dose-dependent, and time-dependent, we performed two exposures to 250 ppb ozone, one to 125 ppb and one to filtered air, each for 3 h of intermittent exercise and separated by at least 1 wk. Twenty-one healthy and 15 asthmatic subjects participated in the study. One hour after the two exposures to 250 ppb ozone we observed a mean increase in sputum neutrophils of 17.9 and 17.9% in healthy and of 20.3 and 15.2% in asthmatic subjects (p < 0.05 each). Twenty-four hours after exposure, the respective values were 11.9 and 14.8%, and 9.1 and 16.1% (p < 0.05 each). In the whole group of subjects, individual changes in the percentage of neutrophils were significantly correlated between the two exposure days 1 h (r = 0.87, p < 0.001; intraclass correlation coefficient [Ri] = 0.86) as well as 24 h (r = 0.79, p < 0.001; Ri = 0.71) after exposure. The percentages of lymphocytes were increased 24 h after exposures (all subjects combined: p < 0.05). The decrease in FEV1 in both groups (p < 0.01), was also reproducible (r = 0.77, p < 0.001), but there were no correlations between changes in sputum parameters and lung function. Exposure to 125 ppb ozone caused a small increase (p < 0. 05) in the percentage of neutrophils in asthmatic subjects and in the concentrations of interleukin-8 in both groups combined. Our data demonstrate that inflammatory and lung function responses to ozone differ between individuals and are reproducible but not related to each other. Therefore, these responses appear to represent two independent factors underlying the airway response to ozone.

Adult↗
PubMed1994

Behavior of different suture materials in the urinary bladder of the rabbit with special reference to wound healing, epithelization and crystallization.

Five urinary bladder incisions were performed in 16 rabbits and the defects closed by plain catgut 4-0, chromic catgut 4-0, polypropylene 4-0, polyglactin 910 4-0 and polyglactin 910 8-0 in the form of an all-layer suture, thereby obtaining a total of 80 suture sites. The running sutures in 8 animals were reviewed by light microscopy after 1, 2, 7 and 15 weeks, and in 8 additional animals after 3 days, 1, 2, 7 and 15 weeks by scanning electron microscopy. Moreover, we analyzed and compared the autopsy findings on gross inspection, the urinary sediments and urinary cultures of the individual animals. Scanning electron-microscopic evaluations showed that epithelization of the intraluminal suture portions can be accomplished after 3 days already. Reduced suture strength and rapid absorption of the suture material prevent later postoperative incrustations. Light-microscopic inspection of the segments of the bladder wall bearing this suture material suggests that a minor inflammatory tissue response around the suture material--with polyglactin 910 8-0 in particular--is more likely to enhance regeneration of the tunica muscularis and to prevent formation of cysts than seen with a long-standing highly inflammatory tissue response around the suture site of catgut threads. In the animal experiment, the polyglactin 910 suture has shown sufficient firmness and proved to be superior to any other suture material as regards the reaction to foreign bodies and inclination to incrustation.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗