Isolation and determination of four potential antimicrobial components from Pseudomonas aeruginosa extracts.

Background:Pseudomonas aeruginosa can cause disease and also can be isolated from the skin of healthy people. Additionally, it exhibits certain antimicrobial effects against other microorganisms.Methods: We collected 60 strains of P. aeruginosa and screened their antimicrobial effects against Staphylococcus aureus (ATCC 25923) using the filter paper-disk method, the cross-streaking method and the co-culture method and then evaluated the antimicrobial activity of the chloroform-isolated S. aureus extracts against methicillin-resistant S. aureus (MRSA, Gram-positive cocci), vancomycin intermediate-resistant S. aureus (VISA, Gram-positive cocci), Corynebacterium spp. (CS, Gram-positive bacilli), Acinetobacter baumannii (AB, Gram-negative bacilli), Moraxella catarrhalis (MC, Gram-negative diplococcus), Candida albicans (CA, fungi), Candida tropicalis (CT, fungi), Candida glabrata (CG, fungi) and Candida parapsilosis (CP, fungi). Results: The PA06 and PA46 strains have strong antimicrobial effects. High-performance liquid chromatography (HPLC) analysis revealed that the major components of PA06 and PA46 that exhibit antimicrobial activity are functionally similar to phenazine-1-carboxylic acid (PCA) and pyocyanin. Preparative HPLC was performed to separate and isolate the 4 major potential antimicrobial components: PA06ER10, PA06ER16, PA06ER23 and PA06ER31. Further, the molecular masses of PA06ER10 (260.1), PA06ER16 (274.1), PA06ER23 (286.1) and PA06ER31 (318.2) were determined by electrospray ionization (ESI) mass spectrometry. Conclusion:P. aeruginosa can produce small molecules with potential antimicrobial activities against MRSA, VISA, CS, MC, CA, CT, CG and CP but not against AB.

Treatment with 17ß-Estradiol Reduced Body Weight and the Risk of Cardiovascular Disease in a High-Fat Diet-Induced Animal Model of Obesity.

Estrogen receptor α (ERα) and estrogen receptor ß (ERß) play important roles in cardiovascular disease (CVD) prevention. Recently, these estrogen receptors were reconsidered as an important treatment target of obesity leading to CVD. In this study, 17ß-estradiol (17ß-E) replacement therapy applied to high-fat diet-induced obese C57B male mice and ovariectomized (OVX) rats were evaluated, and the protective effects against high-fat diet-induced obesity were assessed in C57B mouse hearts. The results showed that 17ß-E treatment activated both ERα and ERß, and ERß levels increased in a dose-dependent manner in high-fat diet C57B mouse cardiomyocytes following 17ß-E treatment. Notably, an almost 16% reduction in body weight was observed in the 17ß-E-treated (12 µg/kg/day for 60 days) high-fat diet-induced obese C57B male mice. These results suggested that 17ß-E supplements may reduce CVD risk due to obesity.

Environmental tobacco smoke increases autophagic effects but decreases longevity associated with Sirt-1 protein expression in young C57BL mice hearts.

Recently, a survey by the Centers for Disease Control and Prevention (CDC) reported that nearly 90% of U.S. adult smokers began smoking at the age of 18. This demonstrates that the exposure to environmental tobacco smoke (ETS) of youngsters today is changing from passive smoking to active smoking (direct inhalation of tobacco). In the current study, an investigation of ETS exposure in young C57BL mice was conducted. After 6 weeks of ETS exposure, the Sirt-1 protein level was decreased and cardiac autophagy was increased in C57BL mice. Furthermore, the IGF2R cardiac hypertrophy signaling pathway was also triggered, although cardiac apoptosis and hypertrophy were not induced. Youngsters' desire to look more mature is one of the psychological factors that impacts smoking amongst young people. Our results suggest that though ETS exposure might cause cardiac autophagy amongst youngsters, the loss of the longevity Sirt-1 protein and the increase in IGF2R cardiac hypertrophy signaling could still promote heart diseases that are age-specific.

Gating of the micturition reflex by tonic activation of bladder cold receptors in the cat.

AIMS: To determine whether C afferents can modify the gating of the Adelta micturition reflex in order to identify the neuronal site of interaction of the two afferent systems. METHODS: Adult female cats, anaesthetized with alpha-chloralose, had their bladder and urethra catherized through a slit in the proximal urethra. Micturition threshold volume was assessed by cystometry and bladder efferent activity recorded simultaneously. The bladder was filled at a slow rate (1.2-3.5 ml/min) with either body-warm saline (control) or menthol solution (0.06 mM) or by cold saline (4 degrees C). RESULTS: Of 14 trial sessions in 5 animals, the threshold volume of the Adelta micturition reflex was consistently reduced by menthol infusions from a control median (md) value of 16.8 to 10.2 ml (P < 0.01). The threshold pressure was also somewhat decreased from md 0.7 to 0.5 kPa (P < 0.05), while the peak pressure or pressure slope did no differ in two situations. Similar results were obtained with slow cold infusions into the bladder (nine sessions in three animals). The threshold volume decreased from md 19.8 to 17.4 ml (P < 0.05). The bladder reflex response to slow menthol or cold infusions had the typical features of an Adelta micturition reflex in that the efferent activity was largely abolished by the bladder Adelta mechanoreceptor unloading. CONCLUSIONS: Gradual tonic activation of bladder cold receptors lowers the threshold volume of the ordinary Adelta micturition, pointing to a segmental spinal mechanism for the gating of the micturition reflex.

Comparison of lycopene and fluvastatin effects on atherosclerosis induced by a high-fat diet in rabbits.

OBJECTIVE: We evaluated the antiatherogenic effect of lycopene in rabbits fed a high-fat diet. METHODS: Forty adult male rabbits were divided into five groups that were fed a standard diet, a high-fat diet, a high-fat diet plus 4 mg/kg of lycopene, a high-fat diet plus 12 mg/kg of lycopene, and a high-fat diet plus 10 mg/kg of fluvastatin, respectively. Lycopene and fluvastatin were administered intragastrically. The level of serum total cholesterol, total triglyceride, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, total antioxidant capacity, and malondialdehyde were measured before and after 4 and 8 wk of experimental treatment. In addition, plasma levels of lycopene, oxidized low-density lipoprotein, serum nitric oxide, and interleukin-1 were measured after the experiment. The area of atherosclerotic plaque and pathologic changes of the aorta were evaluated. RESULTS: Compared with the control, levels of total cholesterol, total triacylglycerol, low-density lipoprotein cholesterol, malonaldehyde, oxidized low-density lipoprotein, and interleukin-1 were increased and total antioxidant capacity and nitric oxide were decreased in the animals with a high-fat diet (P < 0.05). Intragastric administration of lycopene counteracted the change in these parameters (P < 0.05). In this case, the data showed that lycopene in the used dose was better than the fluvastatin intervention. Morphologic analysis revealed that lycopene and fluvastatin markedly reduced the formation of atherosclerotic plaques in the aorta compared with the situation in rabbits on a high-fat diet alone. CONCLUSION: Lycopene, like fluvastatin, significantly attenuated atherogenesis in rabbits fed a high-fat diet.

Inhibition of the bladder cooling reflex in the awake state: an experimental study in the cat.

PURPOSE: We assessed the bladder cooling reflex in the awake cat. The bladder cooling reflex is consistently observed in anesthetized adult cats but not in awake, neurologically normal humans. This discrepancy could indicate a state dependant control of the reflex or a species difference. This study was designed to differentiate between these alternatives, MATERIALS AND METHODS: Under ketamine-xylazine 5 animals had an indwelling catheter inserted into the bladder. The cooling reflex was tested by injections of cold saline into the bladder (4C to 8C), lowering its wall temperature to about 30C to 32C. The volume used (5 ml) was subthreshold for the Adelta micturition reflex, as confirmed by control injections of body warm saline. The procedure was repeated with the animals fully awake and it was well tolerated by all of them. Reflex responses were assessed by induced bladder pressures. RESULTS: Typical bladder cooling reflexes with peak pressures greater than 3 kPa were evoked in all cats when in narcotic sleep (group mean +/- CI 7.4 +/- 3.1 kPa). No such reflexes were elicited when the animals were awake (2.0 +/- 1.0 kPa). The difference was significant at the level of individual animals. CONCLUSIONS: The bladder cooling reflex is suppressed in adult cats during wakefulness, as in humans. This state dependent control of the bladder cooling reflex adds to its resemblance to the extensor plantar response (Babinski's sign).

Cooling of the urinary bladder activates neurons in the dorsal horn of the spinal cord.

Although visceral innocuous cold receptors have been documented, the central termination of their afferents is unknown. We used menthol solution (0.6 mM) to obtain selective activation of cold receptors in the urinary bladder of rats. Innocuous cold stimulation induced Fos expression in a population of neurons in the superficial dorsal horn of L6-S1 segments of the spinal cord. Neurons in other regions of the spinal cord, e.g. the lumbar parasympathetic nucleus or the dorsal commissure region, were activated to a similar degree by menthol and control infusions, indicating a response to bladder filling. Our results are consistent with the proposal that subsets of modality-specific dorsal horn neurons convey specific information regarding the exteroceptive and interoceptive state of the animal.