Drugs under experimental and clinical research最新文献

We have previously shown that nifedipine, one of the most popular dihydropyridine-based calcium antagonists (DHPs), blocked tumor necrosis factor-alpha (TNF-alpha)-induced reactive oxygen species generation and subsequent monocyte chemoattractant protein-1 expression in endothelial cells (ECs), thus suggesting that nifedipine may inhibit monocyte recruitment, an initiating step in atherosclerosis. However, the effect of nifedipine on leukocyte adhesion to ECs, another pivotal step in the early stage of atherosclerosis, remains to be elucidated. In this study, we investigated whether nifedipine could inhibit TNF-alpha-induced vascular cell adhesion molecule-1 (VCAM-1) expression and subsequent leukocyte adhesion to human umbilical vein endothelial cells (HUVEC). Nifedipine significantly inhibited TNF-alpha-induced up-regulation of VCAM-1 mRNA levels in HUVEC. Furthermore, nifedipine was found to block MOLT-3 (a human lymphoblastic cell line) cell adhesion to TNF-alpha-exposed HUVEC. The results suggest that nifedipine could inhibit TNF-alpha-induced leukocyte adhesion to ECs by suppressing VCAM-1 expression. Our present study provides a novel beneficial aspect of nifedipine on atherogenesis.

A new chemical named parrodienes has been extracted from parrots' plumage. From the chemical point of view, parrodienes are polyunsaturated aldehydes similar to carotenoids. On the basis of this similarity we organized some biological experiments to evaluate the inhibition of lipoperoxidation of cell membranes induced by CCl4, protection against ultraviolet rays, anti-inflammatory activity and protection from an increase of ornithine-decarboxylase as marker of tumoral skin alteration. The results of these experiments showed that unsaturated dienes (parrodienes) play an important role on the inhibition and prevention of many biological processes that are at the basis of different pathological disorders.

Routine hospital screening of the resistance of Streptococcus pyogenes to macrolides is usually done using the erythromycin, clarithromycin or azithromycin disk diffusion technique. When a strain is found to be resistant to one of these macrolides, it is generally assumed to be resistant to the whole class. However this approach gives only partial qualitative information because S. pyogenes strains with inducible and M phenotype resistance are still susceptible to 16-membered ring macrolides such as rokitamycin. Seventy-four erythromycin-resistant (22 inducible and 52 M phenotype) strains of S. pyogenes were tested for their susceptibility to rokitamycin and clindamycin (control) by means of the agar disk diffusion test and the results were compared with those obtained using the Epsilometer test, a quantitative technique for measuring bacterial susceptibility and minimal inhibitory concentrations (MIC). Epsilometer testing of erythromycin in comparison with rokitamycin is useful for measuring the real degree of susceptibility of macrolide-resistant strains quickly and simply. This is important because strains with the same disk diffusion diameter do not necessarily have the same MIC, but a scattered distribution of susceptibility.

Impetigo is a contagious superficial pyogenic infection of the skin caused by Staphylococcus aureus and/or by group A Streptococcus. Two main clinical forms are recognized: bullous impetigo and non-bullous impetigo. We present an unusual case of pustular impetigo in a 35-year-old man. The pustules were localized symmetrically in the groin and the patient was successfully treated with clarithromycin. In bullous impetigo, exfoliative toxins produced by Staphylococcus aureus are accepted as the basis for the bulla formation just below the stratum granulosum. Although clarithromycin is considered to be a second-choice therapy for bullous impetigo, it was highly effective in our case.

Advanced glycation end products (AGEs), the senescent macroprotein derivatives that form in increased amounts in diabetes, have been implicated in the pathogenesis of diabetic vascular complications. Indeed, AGEs elicit oxidative stress generation in vascular wall cells through an interaction with their receptor (RAGE), thus playing an important role in vascular inflammation and altered gene expression of growth factors and cytokines. We have previously shown that nifedipine, one of the most popular dihydropyridine-based calcium antagonists, blocked tumor necrosis factor-alpha-induced monocyte chemoattractant protein-1 expression in endothelial cells (ECs) through its antioxidative properties. However, the effects of nifedipine on AGE-exposed ECs remain to be elucidated. In this study we investigated whether nifedipine could inhibit the AGE-induced reactive oxygen species (ROS) generation and subsequent RAGE gene expression in human umbilical vein endothelial cells (HUVEC). Nifedipine completely inhibited AGE-induced ROS generation in HUVEC. Furthermore, nifedipine was found to prevent up-regulation of RAGE mRNA levels in AGE-exposed HUVEC. These results demonstrate that nifedipine can inhibit RAGE overexpression in AGE-exposed ECs by suppressing ROS generation. Our present study suggests that nifedipine may have therapeutic potential in the treatment of patients with AGE-related disorders such as diabetic vascular complications.

Benign prostatic hyperplasia (BPH) is the noncancerous, uncontrolled growth of prostate gland cells and stroma that can cause difficulty urinating. Fruit lipid extracts from saw palmetto, a palm from the Arecaceae family, are used for BPH management. The Cuban royal palm, Roystonea regia, is also a member of the Arecaceae family and therefore it was appropriate to investigate the protective effects of Roystonea regia fruit lipid extracts on prostatic hyperplasia. The aim of this study was to investigate whether D-004, a lipid extract from Roystonea regia fruits, prevented testosterone-induced PH in castrated and intact rodents. Two series of experiments were performed. The first one was conducted in castrated and intact rats, distributed into five groups of 10 rats per group. The negative control group was injected with soy oil and treated orally with vehicle, while the four testosterone-injected groups were treated with vehicle (positive control), D-004 100, 200 and 400 mg/kg, respectively. The other experiment was conducted in castrated and intact mice. These were distributed into four groups of 10 mice per group: a negative control group and three testosterone-injected groups, of which one was a positive control, while two received D-004 200 and 400 mg/kg, respectively. At study completion, the rodents were sacrificed and prostates removed and weighed. D-004 at doses of 100, 200 and 400 mg/kg significantly and dose-dependently prevented prostate enlargement in intact and castrated rats and mice. The percentage inhibitions obtained in mice were greater: 77% and 84% for intact and castrated mice, respectively. D-004 therapy did not affect body weight. It is concluded that D-004 administered orally significantly prevented testosterone-induced prostate enlargement in both intact and castrated rodents, indicating that an endogenous supply of testosterone is not necessary to observe such an effect The results of the present investigation support further studies of D-004 on experimental models of prostatic hyperplasia.

Dehydroxymethylepoxyquinomicin (DHMEQ), a synthetic derivative of epoxyquinomicin C, is a potent and specific inhibitor of NF-kappa B in cultured cells. Tritium-labeled DHMEQ was synthesized with sodium borotritium. Specific radioactivity of the synthesized tritium-labeled DHMEQ was 15.45 mCi/mmol. This compound would be for the study of the mechanism of action and the stability of DHMEQ.

In modern industrial societies the attention to public health, especially in relation to food habits, is increasing day by day. Considering this, it's no wonder that wine, the voluptuary drink that best represents human history, is the most interesting compound. The main and best known wine effects on the human body are caused by alcohol, but several other active compounds are present in wine. Above all, resveratrol is able to neutralize free radicals, which can damage DNA and may lead to cancer onset. In this study, we have indagated resveratrol anticancer action, analyzing its effects on both cell cycle and growing of human lymphoma B (DHL-4) cells. MTT colorimetric test, tripan blue dye exclusion assay, and cell cycle analysis showed that resveratrol has a dose-dependent antiproliferative and antiapoptotic action on DHL-4 cells. These results confirm resveratrol's potential therapeutic role on tumors.

The renin-angiotensin system has been implicated in the development and progression of atherosclerosis, thereby contributing to adverse cardiovascular events. However, its role in diabetic retinopathy remains to be elucidated. Since pericyte loss and dysfunction have been considered as one of the characteristic changes of the early phase of diabetic retinopathy, we investigated the effects of angiotensin II (Ang II) on the growth and function of bovine cultured retinal pericytes. Ang II stimulated intracellular reactive oxygen species (ROS) generation in pericytes in a dose-dependent manner. Telmisartan, a newly developed Ang II type 1 receptor antagonist, completely inhibited ROS generation in pericytes induced by Ang II. Ang II decreased DNA synthesis in pericytes, which was significantly prevented by an antioxidant N-acetylcysteine. Furthermore, telmisartan or N-acetylcysteine were found to completely inhibit the Ang II-induced upregulation of vascular endothelial growth factor messenger RNA levels in pericytes. The present results suggest that Ang II-type 1 receptor interaction could induce pericyte loss and dysfunction through intracellular ROS generation, thus being involved in the development and progression of diabetic retinopathy.