Z-ajoene induces apoptosis of HL-60 cells: involvement of Bcl-2 cleavage

Garlic organosulfur components exhibit antitumor activity, but the molecular mechanisms underlying these effects have not been well characterized. We showed that Z-ajoene, a sulfur-rich compound purified from garlic, induced time- and dose-dependent apoptosis in HL-60 cells. This process implied the activation of caspase-3 and the cleavage of the antiapoptotic protein Bcl-2. The caspase inhibitor benzyloxycarbonyl-Val-Ala-Asp-[OMe]-fluoromethylketone inhibited Bcl-2 cleavage and apoptosis induced by Z-ajoene. This effect was partially prevented by treatment of HL-60 cells with the antioxidant N-acetylcysteine. Hence, the transmission of apoptotic signal induced by Z-ajoene involved a reactive oxygen species-dependent pathway leading to caspase-dependent Bcl-2 cleavage.     

Thermostabilization of egg grown influenza viruses

The observation that the addition of deuterium oxide to tissue culture cell harvests stabilized trivalent oral poliovirus vaccine prompted us to examine the effect of deuterium oxide on stabilization of other licensed and experimental live viral vaccines. The most striking effect afforded by deuterium oxide was on stabilization of live, attenuated influenza A and B vaccine candidates grown in the allantoic cavity of embryonated eggs. Thermostabilization with deuterium oxide is much greater than seen with standard stabilization of these live influenza vaccines with sucrose-phosphate-glutamate. Subsequently, we have shown that a similar, stabilization is provided by diluting egg allantoic fluid in water or minimal essential medium. The mechanism of action has been explored but remains uncertain. The implications of being able to stabilize influenza after harvesting from eggs have practical application for utilization of live influenza vaccines and provides a possible way to increase and standardize the potency of inactivated vaccines that may partially degrade in the inimical environment of allantoic fluid during growth and before final vaccine purification and stabilization.     

Deregulated DNA polymerase beta induces chromosome instability and tumorigenesis

To reach the biological alterations that characterize cancer, the genome of tumor cells must acquire increased mutability resulting from a malfunction of a network of genome stability systems, e.g., cell cycle arrest, DNA repair, and high accuracy of DNA synthesis during DNA replication. Numeric chromosomal imbalance, referred to as aneuploidy, is the most prevalent genetic changes recorded among many types of solid tumors. We report here that ectopic expression in cells of DNA polymerase beta, an error-prone enzyme frequently over-regulated in human tumors, induces aneuploidy, an abnormal localization of the centrosome-associated gamma-tubulin protein during mitosis, a deficient mitotic checkpoint, and promotes tumorigenesis in nude immunodeficient mice. Thus, we find that alteration of polymerase beta expression appears to induce major genetic changes associated with a malignant phenotype.     

Antitumor activity of Z-ajoene, a natural compound purified from garlic: antimitotic and microtubule-interaction properties

Ajoene, a garlic stable oil-soluble sulfur rich compound was generally isolated as a mixture of two isomers [(E, Z)-4,5,9-trithiadodeca-1,6,11-triene-9-oxide]. It has been described essentially as a potent inhibitor of platelet aggregation in vitro and in vivo. The antiproliferative effects of ajoene and experiments using a single isomer had received little attention. The present study aims at defining the antitumor activities of cis-Z-ajoene in vitro and in vivo. Antiproliferative activity of Z-ajoene was demonstrated against a panel of human tumor cell lines with IC(50) values varying from 5.2 mM to 26.1 mM and at a lower extent in normal marsupial kidney cells (PtK2). Meanwhile, Z-ajoene arrested HL60 cells in G(2)/M phase of cell cycle in a dose and time-dependent way. In PtK2 cells, exposure to 20 microM Z-ajoene for 6 h induced a complete disassembly of the microtubule network, that was associated with an increased number of cells blocked in early mitotic stages. An IC(50) for microtubule disassembly of 1 microM was determined by a fully automated microplate-based multi-detection reader. In vitro, a reversible inhibition of the microtubule protein assembly was observed with an IC(50) of 25 microM Z-ajoene. In vivo, Z-ajoene inhibited tumor growth by 38% and 42% in mice grafted with sarcoma 180 and hepatocarcinoma 22, respectively. For the first time, Z-ajoene was shown to be a potent inhibitor of tumor cell growth both in vitro and in vivo. The microtubule cytoskeleton appeared to be one of the Z-ajoene targets, but the mechanisms by which Z-ajoene interacted with microtubule appeared different from those of other microtubule poisons such as those of the Vinca alkaloids family. The ability of Z-ajoene to preferentially suppress the growth of neoplastic cells could provide a new approach in tumor therapy.     

The impact of reproductive events on the course of bipolar disorder in women

BACKGROUND: Little is known about the impact of female reproductive hormones on the course of bipolar disorder. This study was designed to assess the influence of reproductive events and hormonal therapies on the course of bipolar disorder in women. METHOD: Fifty women with DSM-IV bipolar disorder completed a structured clinical interview to assess the impact of reproductive events on the course of their illness. RESULTS: The onset of bipolar disorder occurred before menarche in 32% (N = 16) of women; 18% (N = 9) experienced the onset within 1 year of menarche. Most women did not receive an accurate diagnosis of nor treatment for bipolar disorder until after they had children, and therefore the majority were not treated with mood stabilizers during or immediately after pregnancies. Of women with children, 20 (67%) of 30 experienced a postpartum mood episode. Of the women who had postpartum episodes after delivery of a first child, all had episodes after subsequent pregnancies. Having a postpartum mood episode after a first pregnancy significantly increased the risk of a postpartum episode after subsequent deliveries (p = .02). Postpartum episodes were almost exclusively depressive. Increased depressive symptoms during pregnancy were significantly associated with postpartum mood episodes (p = .01). Women who were not using hormone replacement therapy (HRT) were significantly more likely than those who were using HRT to report worsening of symptoms during perimenopause/menopause (p = .02). CONCLUSION: These data suggest that hormonal fluctuations are associated with increased risk of affective dysregulation and mood episodes in women with bipolar disorder.     

Structure-activity relationships for selected fragrance allergens

Fragrance substances represent a very diverse group of chemicals, a proportion of them providing not only desirable aroma characteristics, but also being associated with adverse effects, notably the ability to cause allergic reactions in the skin. However, efforts to find substitute materials are hampered by the need to undertake animal testing to evaluate both the presence and the degree of skin sensitization hazard. One potential route to avoid such testing is to understand the relationships between chemical structure and skin sensitization. In the present work we have evaluated two groups of fragrance chemicals, saturated aldehydes (aryl substituted and aliphatic aldehydes) and alpha,beta-unsaturated aldehydes. Data on their skin sensitization potency defined using the local lymph node assay has been evaluated in relation to their physicochemical properties. The initial outcome has been consistent with the concept that alpha,beta-unsaturated aldehydes react largely via Michael addition, whilst the group of saturated aldehydes form Schiff bases with proteins. Simple models of chemical reactivity based on these mechanisms suggest that it may be possible to predict allergenic potency. Accordingly, the evaluation of an additional group of similar aldehydes is now underway to assess the robustness of these models, with some emphasis being based on ensuring a wider spread of chemical reactivity.     

Development and initial testing of a multimedia program for computer-assisted cognitive therapy

A multimedia program for computer-assisted psychotherapy has been developed to help patients learn cognitive therapy skills. The program is designed to provide psychoeducation, teach self-help methods, and give information to clinicians on the patient's progress in using the software. Multimedia technology is utilized to engage users in the learning process and to make the program accessible for persons who do not have computer or keyboard skills. A preliminary study with 96 subjects who used the software along with treatment as usual found that 75 (78.1%) completed the entire program. Users indicated a high rate of acceptance of this form of computer-assisted therapy, and mean scores on a measure of cognitive therapy knowledge were significantly improved.