Antifungal evaluation of bis Mannich bases derived from acetophenones and their corresponding piperidinols and stability studies

The development of resistance to current antifungal therapeutics drives the search for effective new agents. The fact that some acetophenone-derived Mannich bases had shown antifungal activities in our previous studies led us to design and synthesize acetophenone-derived bis Mannich bases, B1-B5, bis(beta-aroylethyl)methylamine hydrochlorides, to evaluate their antifungal activity. These bis Mannich bases were then converted to the corresponding piperidinols, C1-C5, which are structural isomers of bis derivatives, 3-aroyl-4-aryl-1-methyl-4-piperidinol hydrochlorides, to see alterations in biological activity. A stability study of B1 and Cl was also carried out to estimate whether they alkylate the thiols. All compounds studied have shown antifungal activity, especially against dermatophytes (Trichophyton rubrum, Trichophyton mentagrophytes, Trichophyton tonsurans, and Microsporum canis), in the concentration range studied (2-128 microng/ml). The activity was especially apparent against T. tonsurans. All compounds had at least equal antifungal activity compared with the reference compound amphotericin-B against T. tonsurans. Bis Mannich bases were generally found to be more potent compounds than their structural isomer piperidinols. The results of our stability studies suggest that thiol alkylation may contribute to the antifungal activity of the Mannich bases synthesized. Even though all compounds showed antifungal activity against dermatophytes, bis Mannich bases B1, B2, B4, and B5 appear to have potential for developing novel antifungal agents against dermatophytes.     

阿德福韦双酯治疗拉米夫定耐药的慢性乙肝患者时出现的耐药问题

背景:阿德福韦双酯(ADV) 是一种有效治疗野生型和耐拉米夫定乙肝病毒(HBV)的核苷酸类药物。在使用核苷酸类药物治疗慢性乙肝时,当治疗时间为 48、96、144周时,耐ADV变异体出现的累积发生率分别为0、 0．8-3％和0-5．9％。目的:研究67例对拉米夫定耐药且接受ADV治疗的慢性乙肝患者耐ADV病毒变异体的表型和基因型特点。方法:HBV DNA含量采用实时定量PCR技术。ADV变异体检测采用基质辅助激光解吸电离／飞行时间质谱为基础的基因分型     

Behavioral sensitization and voluntary ethanol drinking in alcohol-preferring AA rats exposed to different regimens of morphine treatment

The purpose of the study was to investigate the effects of three different regimens of morphine treatment on subsequent voluntary ethanol drinking in alcohol-preferring AA (Alko Alcohol) rats. The rats were given morphine subcutaneously either intermittently on alternating days (15 x 10 mg/kg or 5 x 5-20 mg/kg in escalating doses) or subchronically on four consecutive days (3-20 mg/kg/d). Horizontal locomotor activity was monitored after challenges with additional morphine injections (3 mg/kg) ten days and six weeks after termination of the pretreatment to test if behavioral sensitization was induced by repeated morphine administration. Both intermittent pretreatments induced sensitized locomotor response after the first challenge, whereas subchronic injections did not. After the challenge the rats were given a free choice between tap water and 10% (v/v) ethanol solution for four weeks. The rats pretreated and challenged with morphine did not differ significantly in the acquisition of ethanol drinking from the saline-treated controls. In contrast, ethanol drinking was impaired during the first week of ethanol access in the saline-treated rats given a single morphine injection. The second morphine challenge given after the ethanol-drinking phase did not reveal sensitization in any of the groups. The results suggest that pattern of morphine administration rather than the dose or number of exposures to the drug is the most important factor in induction of behavioral sensitization, and that exposure to ethanol may interfere with this process. They also support earlier findings showing that acute morphine may suppress voluntary ethanol drinking, but failed to provide clear evidence for behavioral sensitization to morphine contributing to predilection towards ethanol in AA rats.     

Treatment of Allergic Bronchopulmonary Aspergillosis with Fluconazole and Itraconazole

Treatment of allergic bronchopulmonary aspergillosis (ABPA) has remained both problematic as well as controversial. Although the sheet anchor in treatment of ABPA still remains steroids, various workers have tried oral antifungals (fluconazole and itraconazole) with encouraging results. This study evaluates the effect of fluconazole or itraconazole in the treatment of ABPA patients and compares them with the patients who had received palliative therapy other than antifungals. Case records of 44 proven cases of ABPA treated at our referral service hospital during February 1998 to April 2001 were analyzed. In addition to oral and inhaled bronchodilators, 16 patients received fluconazole 150 mg OD and 13 patients itraconazole 200 mg OD for six months. Response to therapy was assessed clinically, radiologically and by spirometry every 3 months. Patients who did not receive antifungals had chronic course characterized by airway obstruction, recurrent pulmonary consolidation and obstructive defect on pulmonary function test (PFT). Patients treated with itraconazole had better control of asthma symptoms, less requirement of reliever inhalers, steroids and lesser exacerbations of asthma during follow-up even after stopping antifungal. Fluconazole group had better control of symptoms but improvement in other parameters was not statistically significant. From this study it was evident that itraconazole improved the symptoms of airway obstruction, pulmonary functions, pulmonary opacities and decreased exacerbations during follow up.Key Words: Allergic bronchopulmonary aspergillosis, Fluconazole, Itraconazole     

Visual awareness of low-contrast stimuli is reflected in event-related brain potentials

Visual awareness was studied in 11 subjects by using coherent and scrambled objects as stimuli. The stimuli were presented near the subjective perceptual threshold. Explicitly recognized stimuli elicited a specific negative ERP deflection peaking at 460 ms. Our reaction time experiment suggests that this visual awareness negativity (VAN) is similar to that found previously at a shorter latency. We propose that VAN might reflect the exact moment of becoming aware of the task-relevant stimulus properties and provide an online marker of the temporal dynamics of visual awareness.     

Differential behavioural sensitization to intermittent morphine treatment in alcohol-preferring AA and alcohol-avoiding ANA rats: role of mesolimbic dopamine

Alcohol-preferring AA (Alko Alcohol) and alcohol-avoiding ANA (Alko Non-Alcohol) rats have well-documented differences in their voluntary ethanol consumption and brain opioidergic systems. The aim of the present study was to investigate whether these rat lines differ in their susceptibility to morphine-induced behavioural and neurochemical sensitization. The rats were given 15 injections of morphine (10 mg/kg, s.c.) or saline every other day. Locomotor activity and release of dopamine in the nucleus accumbens were monitored after a challenge with additional morphine injections (10 mg/kg) 1 and 5 weeks after withdrawal from the repeated treatment. Morphine increased locomotion more in the previously morphine-treated rats than in the saline-treated controls. Furthermore, AA rats were more sensitive to this effect of morphine than ANA rats. Accumbal morphine-induced dopamine release was significantly higher in the morphine-treated AA than ANA rats after the first challenge injection 1 week from withdrawal, but no differences were observed after the second challenge. The brain and plasma concentrations of morphine were similar among the lines suggesting that the differences in the effects of morphine cannot be explained in terms of differential pharmacokinetics of morphine in these lines. These data show that AA rats are more susceptible to morphine-induced behavioural sensitization than ANA rats. Furthermore, it suggests that mesolimbic dopamine has at best only a transient role in the expression of opioid-induced behavioural sensitization. The relationship between the mechanisms underlying the differential sensitivity of these rat lines to the effects of repeated morphine and voluntary ethanol drinking remains to be determined.