Three pulmonary surthctant preparations: from human amniotic fluid, from bronchoalveolar lavage fluid, and from cattle lung tissue homogenate were tested in preclinical studies. The preparations are nontoxic, possess no mutagenic, teratogenic, and allergic activities and do not modify visceral morphology after repeated injections. After a single intratracheal administration the drugs normalize arterial blood oxygenation in 15-30 rain and arrest the respiratory distress syndrome in dogs, which is confirmed roentgenologically and clinically.
Key Words: respiratory distress syndrome; surfactant; pharmacological properties; therapeutic activityThe respiratory distress syndrome (RDS) is one of the major causes of neonatal and adult mortality [3,5]. About 30,000 babies with RDS are annually born in Rnssia; in the USA 150,000 RDS cases are recorded annually in adults. In RDS 15-30% newborns and 50-70% adults die [3,5,7]. In preterm newborns RDS is caused by immaturity of type 2 alveolocytes and the resultant primary deficiency of puhnonary surthctant (PS) [2]. In RDS of adults, PS deficiency is secondary, developing as a result of structural and functional disorders in the airblood barrier. It often develops after multiple injury, sepsis, shock lung, radiation injury, etc. Natural and synthetic PS preparations have been widely used all over the world: smwana (USA), surfactant-TA (Japan), curosurf (Italy), alveofact (Germany), exosurf (UK) [8].We developed a technologically inexpensive method for preparing natural PS and chalacterized their physicochemical properties. Three preparations were studied: human PS isolated from parturients' amniotic fluid, PS from bronchoalveolar iavage fluid (PS-BLF), and PS prepared by water-salt extraction of finely dispersed cattle lung (PS-WSE).The pharmacological and therapeutic properties of these PS preparations are studied.
Surfactant-BL was administered to rats via the inhalation route from day 1 or day 8 after intratracheal injection of bleomycin. Bronchoalveolar lavage and morphological characteristics of the lungs were compared. Administration of surfactant-BL at the early terms efficiently reduced the severity of bleomycin-induced alveolitis and atelectases.
Purpose: To study the potential of using radiopharmaceutical “Sodium Fluoride 18F” in order to reveal foci of malignant tumors in animals’ bones by positron emission tomography (PET).
Material and methods: Two experimental models (human prostate adenocarcinoma PC 3 and Pliss lymphosarcoma) were used. Tumor cell PC 3 suspensions were injected under a hip periosteum of the BALB/c nude line mice or outbred rats (Pliss lymphosarcoma). Radiopharmaceutical was injected into a tail vein of animals with developed tumors. Then PET scanning was performed for these animals.
Results: Effective half-life of radiopharmaceutical from blood was 9.45 min, from skeleton bones - 77.5 min and tumors – 99 min. The hyperfixation level of radiopharmaceutical in the tumor was sufficient to image tumors by PET. In areas of the tumor from cells of prostate adenocarcinoma PC 3 and Pliss lymphosarcoma the uptake rate of radiopharmaceutical was quite high during an hour that resulted in a high contrast image of tumors in animals’ bones. T/NT ratio tumor/bone in rats with Pliss lymphosarcoma was increased in the first 20 min after administration of the radiopharmaceutical, and then slowly decreased. Nevertheless, in 40 minutes after injection of the radiopharmaceutical T/NT ratio tumor/bone remained quite high – more then 1.7, and T/NT ratio tumor/muscle exceeded to 9.0.
Conclusion: The uptake level and fixation time of the radiopharmaceutical in tumor foci, as well as low activity value and its rapid excretion from intact tissues show the expediency of the use of “Sodium Fluoride 18F” to diagnose intraosseous foci of malignant diseases.
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