A biochemical study on combined treatment of experimental silicosis with tetradrine-PVNO and tetradrine-QOHP in rats.

A better understanding is needed to explain the mechanism of therapeutic effect of combined use of tetradrine-PVNO and tetradrine-QOHP which play very important roles in treatment of silicosis. Blood prolidase (PLD), monamine oxidase (MAO) and plasminogen (PLG) in silicotic rats after treatment with tetradrine-PVNO or tetradrine-QOHP were measured. The values obtained were compared with the untreated silicotic rats. It was found that the silicotic rats that received tetradrine-PVNO showed significant increase in PLD and decrease in PLG, but no significant change in MAO. The PLD in plasma of silicotic rats that received tetradrine-QOHP were elevated significantly, but PLG and MAO did not change appreciably. These findings suggest that the combined use of tetradrine-PVNO and tetradrine-QOHP can accelerate the degradation of collagen in silicotic rats.

[Inhalation treatment of silicosis with Kexiping]. / Inkhalatorno lechenie na silokozata s Keksiping.

The inhalation treatment of silicosis with polyvinyl-pyridine-oxide of molecule weight about 90,000 under the name Kexiping is the most perspective method at the moment for etiological effect of the silicotic fibrosis. The authors performed two 6-week inhalation course with interval of 6 months with 38 ill with silicosis. The daily dose 10 ml of 4% solution of Kexiping "Bayer". The first results alone and in comparison with the control group of 50 patients are very encouraging. The tolerance to the preparation is excellent, with no side effects or unfavourable deviations in the paraclinical indices. Further extensive, therapeutic applications and inhalation prophylaxis with healthy persons subject to high dust risk are completely justified. For final evaluation of the long-term effect a continuous observation of both treated and controls is necessary.

Long-term follow-up observations of the therapeutic effect of PVNO on human silicosis.

The effect of PVNO treatment on human silicosis was observed in 7 cases over a period of 9 years lasting from 1965 to 1974. The drug was given intramuscularly and by way of inhalation, respectively. The comparison of the radiographs taken before, during and 3 years after the administration of PVNO showed that during treatment the tendency of fibrotic progression was delayed in 4 cases while 2 cases were slightly progressive, and one was markedly progressive, 3 years after discontinuation of the PVNO treatment, only one case remained stable, two cases were slightly and 4 cases markedly progressive. These observations indicate that PVNO treatment may have an effect on the delay and control of silicosis progression in a portion of patients, but after discontinuation of the treatment further progression is possible.

[Effect of inhalations of polyvinylpyridine-N-oxide on the development of experimental silicosis]. / Vliianie ingaliatsii polivinilpiridin-N-oksida na razvitie éksperimental'nogo silikoza.

Experiments on albino rats showed that polyvinylpyridine-N-oxide (PVNO) inhalations (mol. mass 2000; 9.8 +/- 1.2 and 99 +/- 4 mg/m3 for 7 months) slowed down the course of silicosis developing with a gradual entrance and uniform distribution of dust in the lungs, but proved little effective with a one-time introduction of a large amount of "aggressive" dust because of the difficulty for the drug to reach and penetrate the sclerosed sections of the tissue. Considering low toxicity and an insignificant cumulative effect of PVNO, the electivity of its accumulation in the lungs during inhalation and marked protective action of low doses the authors hold it expedient to employ the inhalation method of administering the polymer for prevention of silicosis, while its use for curative purpose is not recommended.