Process optimization and biocompatibility of cell carriers suitable for automated magnetic manipulation.

There is increasing demand for automated cell reprogramming in the fields of cell biology, biotechnology and the biomedical sciences. Microfluidic-based platforms that provide unattended manipulation of adherent cells promise to be an appropriate basis for cell manipulation. In this study we developed a magnetically driven cell carrier to serve as a vehicle within an in vitro environment. To elucidate the impact of the carrier on cells, biocompatibility was estimated using the human adenocarcinoma cell line Caco-2. Besides evaluation of the quality of the magnetic carriers by field emission scanning electron microscopy, the rate of adherence, proliferation and differentiation of Caco-2 cells grown on the carriers was quantified. Moreover, the morphology of the cells was monitored by immunofluorescent staining. Early generations of the cell carrier suffered from release of cytotoxic nickel from the magnetic cushion. Biocompatibility was achieved by complete encapsulation of the nickel bulk within galvanic gold. The insulation process had to be developed stepwise and was controlled by parallel monitoring of the cell viability. The final carrier generation proved to be a proper support for cell manipulation, allowing proliferation of Caco-2 cells equal to that on glass or polystyrene as a reference for up to 10 days. Functional differentiation was enhanced by more than 30% compared with the reference. A flat, ferromagnetic and fully biocompatible carrier for cell manipulation was developed for application in microfluidic systems. Beyond that, this study offers advice for the development of magnetic cell carriers and the estimation of their biocompatibility.

Topical tea tree oil effective in canine localised pruritic dermatitis--a multi-centre randomised double-blind controlled clinical trial in the veterinary practice.

Tea tree oil, a volatile oil, is well known for its broad antibacterial and antifungal activity. A standardised and stabilised 10% tea tree oil cream was tested against a commercial skin care cream (control cream) in the management of canine localised acute and chronic dermatitis. Fifty-seven dogs with clinical manifestations of mostly pruritic skin lesions or alterations, skin fold pyodermas and other forms of dermatitis, corroborated by predominantly positive fungal and bacterial skin isolates, were enrolled by seven practising veterinarians and randomly allocated to two study groups (28:29) and were treated twice daily with a blinded topical preparation. After 10 days of treatment, success rates of 71% for the tea tree oil cream and 41% for the control cream (over-all efficacy documented by the veterinary investigator) differed significantly (p = 0.04), favouring tea tree oil cream treatment. Accordingly on day 10, the tea tree oil cream caused significantly faster relief than the control cream (p = 0.04) for two common clinical dermatitis signs, pruritus (occurring in 84 % of dogs) and alopecia. Only one adverse event was reported in the tea tree oil group (suspected not to be causally related to the study drug) and none in the control cream group. The tested herbal cream appears to be a fast-acting safe alternative to conventional therapy for symptomatic treatment of canine localised dermatitis with pruritus.

Phytotherapy of chronic dermatitis and pruritus of dogs with a topical preparation containing tea tree oil (Bogaskin).

Localised dermatitis, for example unspecific eczema or skinfold pyoderma, is a very common diagnosis in dogs. Typical and impressive complaints are pruritus, erythema, erosion and oozing surface. With respect to the underlying disease dermatological treatment is indicated, usually based on antimicrobial and antipruriginous active substances, it can include transient glucocorticoids. An effective and safe alternative might be a phytotherapeutic topical preparation containing tea tree oil. Tea tree oil exerts both antimicrobial and antipruriginous effects. In an open multicenter study efficacy and safety of a standardized 10% tea tree oil cream applied thinly and twice daily for 4 weeks was tested in 53 dogs with chronic dermatitis, particularly non-specific eczema, allergic dermatitis, interdigital pyoderma, acral lick dermatitis and skinfold pyoderma. Analysis of efficacy assessed by investigating veterinarians showed a good or very good response to treatment for 82% of the dogs, significant at a 5% level (p = 0.05). At the end of the study a strong and significant reduction (p = 0.001) as well as disappearance of major symptoms were observed. Only two adverse events (local reactions) possibly related to tea tree oil occurred during therapy. Consequently the tested study medication (Bogaskin) can be considered an alternative for uncomplicated and localised dermatitis in dogs. Bogaskin might allow reduction of other pharmaceutical products, perhaps even replace standard therapy.

Extended NO analysis applied to patients with COPD, allergic asthma and allergic rhinitis.

The recommended method to measure exhaled nitric oxide (NO) cannot reveal the source of NO production. We applied a model based on the classical Fick's first law of diffusion to partition NO in the lungs. The aim was to develop a simple and robust solution algorithm with a data quality control feature, and apply it to patients with known alterations in exhaled NO. Subjects with allergic rhinitis, allergic asthma, chronic obstructive pulmonary disease (COPD) smokers and controls were investigated. NO was measured at three expiratory flow rates. An iteration method was developed to partition NO. The airway tissue content of NO was increased in asthma, 144 +/- 80 ppb (P = 0.04) and decreased in smokers, 56 +/- 36 ppb (P = 0.02). There was no difference between subjects with rhinitis, 98 +/- 40 ppb and controls, 98 +/- 44 ppb. The airway transfer rate was increased in allergic asthma and allergic rhinitis, 12 +/- 4 vs. 12 +/- 5 ml sec(-1), compared to controls, 8 +/- 2 ml sec(-1) (P < 0.001). The alveolar levels were no different from controls, 2 +/- 1 ppb. In COPD the alveolar levels were increased, 4 +/- 2 ppb (P < 0.001). Extended NO analysis reveals from where in the respiratory system NO is generated. Hence, this new test can be added to the tools the physician has for the diagnosis and treatment of patients with respiratory disorders.

N-acetylcysteine in paraquat toxicity: toxicological and histological evaluation in rats.

The therapeutic effect of N-acetylcysteine (NAC) in paraquat-treated rats was investigated. The animals were divided into four groups: A = control; B = NAC; C = paraquat; D = NAC + paraquat. In the appropriate groups, paraquat 20 mg/kg body weight was administered intraperitoneally and 1% NAC solution was provided as drinking water. All surviving rats were killed on the seventh day after paraquat exposure. The lungs were graded histologically on the basis of oedema and cellular infiltration. On histological examination, the lungs of poisoned rats that had received NAC displayed a tendency towards less oedema and cellular infiltration than those of poisoned rats not treated with NAC. It is concluded that NAC might afford some therapeutic effect against paraquat toxicity in rats.

Lack of correlation between the grade of methacholine-induced bronchial hyperreactivity and ipratropium bronchodilation in asthmatics.

In 46 never-smoking randomly chosen patients with non-allergic asthma, 40 to 60 years old, a methacholine hyperreactivity test and lung function tests were performed after inhalation of different doses of ipratropium bromide (IB). The grade of hyperreactivity was measured as the cumulative dose of methacholine necessary to produce a decrease in the forced expiratory volume in one second of 20% of the lowest post-NaCl value (PD20). The following lung function tests were carried out: Lung volumes, ventilatory capacity including flow-volume curves, airway resistance and nitrogen single-breath wash-out test. The bronchodilator effect, measured as a change in the different lung function tests for different doses of IB given (0.08 mg, 0.15 mg and 0.25 mg), was correlated to the grade of hyperreactivity (PD20 dose). No or only a slight correlation was found between the grade of methacholine-induced hyperreactivity and the bronchodilator effects of the different doses of IB. These results indicate a lack of correlation between an anticholinergic bronchodilator effect and the grade of methacholine-induced bronchial hyperreactivity, or possibly an insensitivity of the above-mentioned methacholine test.

Effect of N-acetylcysteine on pulmonary damage due to microembolism in the rat.

The effect of N-acetylcysteine (NAC), a free radical scavenger, was investigated in a microembolism rat model of adult respiratory distress syndrome (ARDS). Microembolism was induced by an intravenous injection of bovine thrombin and an intraperitoneal injection of a fibrinolysis inhibitor, trans-4-aminomethyl-cyclohexane-carboxylic acid (AMCA). NAC counteracted the experimentally induced increase in lung weight, the development of alveolar oedema, and the amount of fibrin in precapillary vessels. There was also a tendency to a decrease of the experimentally induced interstitial oedema caused by the NAC treatment, although it was not statistically significant. Surprisingly, NAC reduced plasma viscosity in both experimental and control animals. It also seemed to increase PaO2 in animals with pulmonary damage, but had a lowering effect on PaO2 in control animals. The results indicate that NAC has a significant preventive effect in this microembolism rat model of ARDS, and that this effect may be achieved through decreased deposition of fibrin, thus counteracting pulmonary oedema, and a decrease in plasma viscosity.

Effect of nebulized ipratropium bromide on lung function in nonallergic bronchial asthma.

The present investigation was performed on 64 randomly chosen never-smoking patients, 40-60 years old, with nonallergic bronchial asthma with an average FEV1 of 69-73% of predicted, a positive methacholine test, a normal serum IgE level, and a negative RAST or skin test to common allergens and not receiving oral steroid treatment. Sensitive spirometric tests were used to evaluate the dose-response effect of inhalation of 0.08, 0.15 or 0.25 mg of ipratropium bromide. The drug caused bronchodilatation with a nearly linear dose-response relationship for static lung volumes, while the total lung capacity was unchanged after this inhalation. Airway resistance decreased and specific airway conductance increased after all doses. Ventilation and flows were better after doses of 0.15 and 0.25 mg than after 0.08 mg. The intrapulmonary gas distribution improved only after inhalation of 0.25 and 0.15 mg. The currently recommended dose of 0.08 mg seems to be suboptimal for dilatation of both small and large airways.

Effect of N-acetylcysteine on fibrin deposition in the rat lung due to intravascular coagulation.

Intravascular coagulation was induced in rats by i.p. injection of a fibrinolysis inhibitor, tranexamic acid (AMCA, 200 mg/kg B.W.), and i.v. injection of bovine thrombin (500 NIH units/kg B.W.) and the fibrin deposition in the lungs was assessed with 125I-labelled fibrinogen. Treatment with N-acetylcysteine (NAC) partly prevented the deposition of fibrin in the lungs, and the disappearance of fibrinogen from the blood, but did not seem to influence the elimination of fibrin in the lungs. The results indicate that NAC may counteract pulmonary damage in this experimental model, by inhibiting intravascular fibrin formation.

Etiology of human liver cancer: controlled prospective study in liver cirrhosis.

The incidence of primary liver cell carcinoma was investigated in a prospective study over 6 yr and 5 mo in 403 clinically unselected patients derived from a homogeneous population by means of serial determination of alpha 1-fetoprotein (AFP) by radioimmunoassay. The diagnosis of liver cirrhosis was proved in 90% by laparoscopy and/or histology and/or autopsy. The incidence of primary liver cell carcinoma in liver cirrhosis in the clinically studied patients was 4.47%, significantly lower than in the autopsy material (11.03%; p less than or equal to 0.025). In the follow-up study, all patients with increasing AFP concentrations exhibited a primary liver cell carcinoma. A transitory rise of AFP (higher than 50 ng/ml) was observed in 15.1% of patients with liver cirrhosis without primary liver cell cancer. In contrast to the results of animal experiments, this transitory rise of AFP was not followed by malignant transformation of the cirrhotic tissue. Posthepatitic liver cirrhosis was observed in 21.57%, postalcoholic liver cirrhosis in 42.93%, and cryptogenic liver cirrhosis in 27.30%. Liver cirrhosis of other etiology occurred in 8.19%. The incidences of primary liver cell cancer in these 4 groups were 4.94, 4.62, 5.45, and 0%, respectively. These differences are not statistically significant, although in absolute figures postalcoholic liver cirrhosis is the main cause of primary liver cell carcinoma in this sample from West Germany. HBs antigen-positive liver cirrhosis was more often associated with primary liver cell cancer than HBs antigen-negative liver cirrhosis (6.58 versus 3.96%); this difference also is not statistically significant. Observations of larger groups of patients may show a higher risk of developing primary liver cell carcinoma in those with a combination of alcohol abuse and HBs antigenemia and/or acute hepatitis in the history. Patients without these 2 risk factors had an incidence of primary liver cell carcinoma of 2.61%; those with 1 risk factor, 5.77%; and those with both risk factors, 10.71%.