N-acetylcysteine modulates doxorubicin-induced oxidative stress and antioxidant vitamin concentrations in liver of rats

Doxorubicin (DOX) is a chemotherapeutic agent, and is widely used in cancer treatment. The most common side effect of DOX was indicated on cardiovascular system by experimental studies. There are some studies suggesting oxidative stress-induced toxic changes on liver related to DOX administration. The aim of the present study was to evaluate whether antioxidant N-acetylcysteine (NAC) relieves oxidative stress in DOX- induced liver injury in rat. Twenty-four male rats were equally divided into three groups. First group was used as a control. Second group received single dose of DOX. NAC for 10 days was given to constituting the third group after giving one dose of DOX. After 10 days of the experiment, liver tissues were taken from all animals. Lipid peroxidation (LP) levels were higher in the DOX group than in control whereas LP levels were lower in the DOX+NAC group than in control. Vitamin C and vitamin E levels were lower in the DOX group than in control whereas vitamin C and vitamin E levels were higher in the DOX+NAC group than in the DOX group. Reduced glutathione levels were higher in the DOX+NAC group than in control and DOX group. Glutathione peroxidase, vitamin A and β-carotene values were not changed in the three groups by DOX and NAC administrations. In histopathological evaluation of DOX group, there were mononuclear cell infiltrations, vacuolar degeneration, hepatocytes with basophilic nucleus and sinusoidal dilatations. The findings were totally recovered by NAC administration. In conclusion, N-acetylcysteine induced modulator effects on the doxorubicin-induced hepatoxicity by inhibiting free radical production and supporting the antioxidant vitamin levels.     

High level expression and purification of recombinant flounder growth hormone in E. coli

Recombinant flounder growth hormone was overproduced in E. coli by using codon optimized synthetic gene and optimized expression conditions for high level production. The gene was cloned into PET-28a expression vector and transformed into E. coli BL21 (DE3). Induction at lower temperature, lower IPTG concentrations and richer growth media during expression resulted in increased expression level. The protein expression profile was analyzed by SDS-PAGE, the authenticity was confirmed by western blotting and the concentration was determined by Bradford assay. In addition, several attempts were made to produce soluble product and all resulted in insoluble product. The overexpressed protein was efficiently purified from inclusion bodies by moderate speed centrifugation after cell lysis. Among the solubilization buffers examined, buffer with 1% N-lauroylsarcosine in the presence of reducing agent DTT at alkaline pH resulted in efficient solubilization and recovery. The denaturant was removed by filtration and dialysis. The amount of the growth hormone recovered was significantly higher than previous reports that expressed native growth hormone genes in E. coli. The methodology adapted in this study, can be used to produce flounder growth hormone at large scale level so that it can be used in aquaculture. This approach may also apply to other proteins if high level expression and efficient purification is sought in E. coli.     

Oral Mucosa Patch Test: A New Tool to Recognize and Study the Adverse Effects of Dietary Nickel Exposure

On contact with the skin, nickel may cause allergic contact dermatitis, which can be diagnosed by an epicutaneous patch test. Nickel exposure via the intestinal mucosa can induce diarrhea, abdominal pain, and swelling. The aim of the present study was to investigate the relationship between these symptoms and nickel intake by means of a novel oral mucosa patch test. Eighty-six patients with intestinal symptoms related to ingestion of nickel-containing foods were submitted to epicutaneous and oral mucosa patch tests for nickel. All patients with positive oral mucosa patch test results were subject to a low-nickel diet and monitored over time. Skin lesions were observed in 33 out of 86 (38.4%) patients evaluated by the epicutaneous patch test. Mucosal lesions were seen in 53 out of 86 (61.6%) patients given the oral mucosa patch test. After 2 months of a low-nickel diet, 52 out of 53 (98.1%) patients showed an improvement of their symptoms. There is a significant correlation between response time of the oral mucosa patch test and the latency of symptoms after ingestion of nickel-containing foods. Consequently, the oral mucosa patch test can be used to recognize and study the adverse effects of dietary nickel exposure that could be defined as allergic contact mucositis. A low-nickel diet is also shown to be an effective treatment for this condition.     

Measuring the lung function in the mouse: the challenge of size

Measurement of the effects of drugs, mediators and infectious agents on various models of lung disease, as well as assessment of lung function in the intact mouse has the potential for significantly advancing our knowledge of lung disease. However, the small size of the mouse presents significant challenges for the assessment of lung function. Because of compromises made between precision and noninvasiveness, data obtained may have an uncertain bearing on the mechanical response of the lung. Nevertheless, considerable recent progress has been made in developing valid and useful measures of mouse lung function. These advances, resulting in our current ability to measure sophisticated indices of lung function in laboratory animals, are likely to lead to important insights into the mechanisms of lung disease.     

Comparison of Mycoplasma agalactiae isolates by pulsed field gel electrophoresis, SDS-PAGE and immunoblotting

Abstract We have analyzed 81 isolates of Mycoplasma agalactiae from four different regions of Italy between 1990 and 1995 in order to identify antigenic differences through SDS-PAGE and Western blotting and chromosomal DNA restriction endonuclease cleavage pattern differences. Antigenic variability in M. agalactiae isolates was investigated analyzing hydrophobic membrane protein fractions by immunoblotting using pooled sheep antiserum from naturally infected sheep. Large restriction fragments obtained cleaving genomic DNAs with Sma I, Nru I, Sal I, Xho I, Bss HII and Kpn I were analyzed by pulsed field gel electrophoresis. Genetic analysis indicates that isolates are all similar without intraspecific differences. This homogeneity was confirmed by immunoblotting: 80 and 50 kDa antigens are present in all strains analyzed.