Multiphase radon generation and transport in porous materials

Radon generation and transport in porous materials involve solid, liquid, and gas phases in the processes of emanation, diffusion, advection, absorption, and adsorption. Oversimplifications, such as representing moist soil systems by air-phase emanation and transport models, cause theoretical inconsistencies and biases in resulting calculations. Detailed Rn rate balance equations for solid, liquid, and gas phases were analyzed and combined using phase equilibrium constants to derive a single diffusive-advective rate balance equation in the traditional form. The emanation, diffusion, and permeability coefficients in the new equation have expanded definitions and interpretations to include Rn phase transfer. Radon adsorption was characterized by an exponential moisture dependence, and diffusion and permeability constants utilized previous moisture relationships. Correct boundary and interface conditions were defined, and the unified theoretical approach was applied to field data from a diffusion-dominated system and to laboratory data from an advection-dominated system. Measured 222Rn fluxes and concentrations validated the modeled values within the measurement variability in both applications.     

The induction of epidermal ornithine decarboxylase following tape stripping is inhibited by a topical vitamin D3 analogue (MC903)

The efficacy of MC903, a vitamin D3 analogue, in reducing hyperproliferation as determined by levels of ornithine decarboxylase (ODC) was investigated in a double-blind study of 15 patients with chronic plaque psoriasis. The lesions of psoriasis were treated for 8 weeks with MC903 in one of two different cream bases or with a placebo cream. Biopsies were taken before and after treatment. In addition an uninvolved area of skin was treated during the last 3 weeks and this as well as control areas were then sellotape stripped and biopsied after 8 h. Clinical improvement was seen in eight out of 11 patients treated with MC903 but there was no reduction in the level of ODC in psoriatic lesions after 8 weeks of treatment. The levels of ODC in the tape-stripped uninvolved skin after 3 weeks of treatment with MC903 averaged 22.5 +/- 4.2 pmol/min/mg protein as compared to 58.6 +/- 12.6 pmol/min/mg protein (P = 0.004). The trauma-induced induction of ODC activity was markedly inhibited by the application of MC903.     

Expression of CD35 (CR1) and CD11b (CR3) on circulating neutrophils and eosinophils from allergic asthmatic children

Complement receptors on neutrophils and eosinophils play a role in activation and adhesion. During asthmatic reactions these receptors have been found elevated on circulating granulocytes. In the present study we compared the expression of CD35 (complement receptor type 1) and CD11b (complement receptor type 3) on neutrophils and eosinophils from asthmatic and non-asthmatic children. This was done in whole blood samples using depolarized light scattering for the discrimination of neutrophils and eosinophils. The non-stimulated expression as well as the upregulated expression of receptors by the chemotactic peptide N-formylmethionyl-leucyl-phenyl-alanine (fMLP) were studied. The results showed that without prior stimulation only the expression of CD35 on neutrophils was significantly elevated in children with asthma (P<0.05). After up-regulation with fMLP, the CD11b expression on neutrophils (P<0.005, fMLP: 0.002 microM) and eosinophils (P<0.05, fMLP: 0.02 microM) was significantly higher in asthmatic children than in the controls. These results indicate that the inducible expression of CD11b on neutrophils and eosinophils from allergic asthmatic children is primed in vivo.     

Use of carbon fibers for repair of abdominal-wall defects in rats

Carbon in the form of 8-micron fibers induces growth of connective tissue. The purpose of this study was to measure and histologically characterize tissue ingrowth occurring in carbon fibers implanted for up to 12 months in abdominal-wall defects in rats, compared with polypropylene mesh. Carbon fibers induced significantly more tissue ingrowth than polypropylene mesh at 6 to 12 months postoperatively. The predominant tissues associated with carbon fibers and polypropylene mesh were dense connective tissue and fat, respectively. Fragmentation of the implants did not occur, and implant debris was not found in the regional lymph nodes. Carbon fibers are potentially useful for reinforcing abdominal-wall defects.     

Isoquinoline Derivatives Isolated from the Fruit of Annona muricata as 5-HTergic 5-HT1A Receptor Agonists in Rats: Unexploited Antidepressive (Lead) Products

The fruit and the leaves of Annona muricata (Annonaceae) are used in traditional medicine for their tranquillizing and sedative properties. Extracts of the plant have been shown to inhibit binding of [³H]rauwolscine to 5-HTergic 5-HT_1A receptors in calf hippocampus, and three alkaloids, annonaine ( 1 ), nornuciferine ( 2 ) and asimilobine ( 3 ), isolated from the fruit have been shown to have IC50 values of 3 μm , 9 μm and 5 μm , respectively, although in ligand-binding studies it was not possible to determine whether interaction of these ligands with the receptor was agonistic or antagonistic. This paper presents the results of functional assays of the alkaloids. The inhibition of cAMP accumulation was tested in NIH-3T3 cells stably transfected with the 5-HT_1A receptor from man. None of the alkaloids showed antagonistic properties towards the 5-HT_1A receptors because in the antagonistic tests no influence on the forskolin-stimulated increase of cAMP level was detected. Full agonistic properties were measured for all three compounds; the inhibition constants (K_i) for 1, 2 and 3 were < 10 μm . Inhibition of the binding of the radioligand to the 5-HT_1A receptor was observed in every ligand-binding assay performed with the alkaloids; the K_i values for 1, 2 and 3 were in the μm range. These results imply that the fruit of Annona muricata possesses anti-depressive effects, possibly induced by compounds 1, 2 and 3 , and that in the past potent leads for the development of anti-depressive therapeutics have not been used.     

Granular cell tumours of the lower respiratory tract

Granular cell tumours rarely involve the lower respiratory tract. We report eight cases surgically resected at our institution. There were four females and four males, aged between 18 to 56 years (mean 40). One tumour associated with a peripheral lung adenocarcinoma was asymptomatic. The other lesions presented with obstructive pneumonitis (3 cases), haemoptysis (2), dyspnea (1) or cough (1). These tumours were tracheal (1) or bronchial (6) and one case was located in the lung parenchyma. Four cases were multicentric with associated lesions located in a bronchus (2), the oesophagus (1) or a mediastinal lymph node (1). All tumours, with the largest diameter ranging from 0.5–4.5 cm, were histologically invasive. The tumours were positive for S-100 protein, neuron specific enolase, KP1 (CD68) and vimentin. No tumour expressed desmin, keratin or p53 oncoprotein. Our study demonstrates that, in spite of marked anatomical and clinical polymorphism, the rare granular cell tumours of the lower respiratory tract have a constant histological appearance. Our observations confirm that large tumours (> 8–10 mm) usually extend beyond the tracheo-bronchial cartilages and, therefore, only surgical treatment may avoid recurrence.