Determination of type-specific synthetic peptide antibodies to hepatitis delta virus ]

Nine peptides from immunodominant (53-68 and 65-80 aa) and hypervariable (201-213 aa) regions derived from delta antigen sequences corresponding to 3 HDV genotypes were synthesized. Type specificity of antibodies to the resultant peptides was evaluated by indirect enzyme immunoassay with sera from patients with hepatitis D and asymptomatic carriers of anti-delta antibodies. Analysis of the results showed that HDV circulating in the Central Volga region belongs to type I in the majority of cases. High heterogeneity and changeability of HDV genome during the period of transition from acute forms to asymptomatic carriership was revealed. Possibility of circulation of new hybrid HDV strains causing mixed infection in Russia is discussed.     

IL-6 Deficiency Causes Enhanced Pathology in Twitcher (Globoid Cell Leukodystrophy) Mice

The expression of IL-6 is greatly enhanced in the twitcher mouse (S. M. LeVine and D. C. Brown, 1997, J. Neuroimmunol. 73, 47-56), which is an authentic animal model of globoid cell leukodystrophy (Krabbe's disease). In order to investigate the role of IL-6 in this disease, twitcher/IL-6-deficient mice were generated and the pathology was compared between them and regular twitcher mice. Twitcher/IL-6-deficient mice had a more severe disease than regular twitcher mice: they had an earlier onset day of twitching, a greater number of PAS-positive cells, a greater susceptibility to LPS, an exaggerated gliotic response around some vessels, an elevated level of TNF-alpha, and a compromised blood-brain barrier, which was evaluated by three independent measures. This latter finding indicates that IL-6 plays a role in maintaining the integrity of the BBB, and it raises the possibility that IL-6 functions in a similar manner in other diseases of the CNS. LPS was found to greatly shorten the life of twitcher and twitcher/IL-6-deficient mice compared to genotyped-matched saline-injected mice. This result indicates that a proinflammatory condition can exacerbate an underlying CNS pathology, which could help explain why some leukodystrophy patients display their initial symptoms following a fever or blow to the head.     

Damaging effects of chronic low-dose methotrexate usage on primary bone formation in young rats and potential protective effects of folinic acid supplementary treatment

Methotrexate (MTX) is a most commonly used anti-metabolite in cancer treatment and as an anti-rheumatic drug. While MTX chemotherapy at a high dose is known to cause bone growth defects in growing bones, effects of its chronic use at a low dose on growing skeleton remain less clear. Here, we examined effects on bone growth of long-term MTX chemotherapy at a low dose in young rats, and potential protective effects of supplementary treatment with antidote folinic acid (given ip at 1 mg/kg 6 h after MTX). After two cycles of 5 once-daily MTX injections (at 0.75 mg/kg, 5 days on/9 days off/5 days on), histological analysis showed that MTX at this dose caused significant reduction in heights of growth plate and primary spongiosa bone on day 22 compared to controls (P<0.05). In contrast, a similar dosing regimen but at a lower dose (0.4 mg/kg) caused only slight or no reduction in heights of both regions. However, after the induction phase at this 0.4 mg/kg dosing, continued use of MTX at a low dose (once weekly at 0.2 mg/kg) caused a reduction in primary spongiosa height and bone volume on weeks 9 and 14, which was associated with an increased osteoclast formation and their bone surface density as well as a decreased osteoblast bone surface density in the primary spongiosa. Folinic acid supplementation was shown able to prevent the MTX effects in the primary spongiosa. These results suggest that acute use of MTX can damage growth plate and primary bone at a high dose, but not at a low dose. However, long-term use of MTX at a low dose can reduce primary bone formation probably due to decreased osteoblastic function but increased osteoclastic formation and function, and supplementary treatment with folinic acid may be potentially useful in protecting bone growth during long-term low-dose MTX chemotherapy.     

Neurotrimin is an estrogen-regulated determinant of peripheral sympathetic innervation

Mechanisms underlying axon degeneration in peripheral neuropathies and during normal remodeling are poorly understood. Because estrogen induces widespread sympathetic axon degeneration in female reproductive tract smooth muscle, we surveyed estrogen-regulated genes in rat myometrium. Microarray analysis revealed that the neural cell adhesion protein neurotrimin (Ntm) was markedly up-regulated 6 hr and down-regulated 24 hr after injection of 17beta-estradiol, and real time RT-PCR confirmed this pattern of expression. Protein analysis by Western blotting showed that uterine Ntm protein is also up-regulated in vivo 6-24 hr following estrogen injection and that Ntm protein is increased selectively in the myometrium during the high-estrogen phase of the estrous cycle. Cultured myometrial smooth muscle cells display perinuclear accumulations of Ntm protein, and 17beta-estradiol also increases intracellular levels of Ntm and its secretion into the culture medium. To determine if neurotrimin is required for estrogen-induced sympathetic pruning, sympathetic neurons were cocultured with uterine smooth muscle cells transfected with siRNA directed against Ntm. Although estrogen inhibited neurite outgrowth in nontransfected cocultures, estrogen's ability to reduce sympathetic outgrowth was impaired substantially following Ntm down-regulation. This supports a role for neurotrimin in mediating estrogen-induced sympathetic pruning in some peripheral targets. Together with earlier studies, these findings support the idea that physiological sympathetic axon degeneration is a multifactorial process requiring dynamic regulation of multiple repellant proteins.     

Drug interaction studies between paclitaxel (Taxol) and OC144-093--a new modulator of MDR in cancer chemotherapy.

The MDR modulator, OC144-093, is a potential candidate for use in cancer therapy and exhibits potent biological activity in vitro and in vivo when combined with anticancer agents such as paclitaxel. Its inhibitory interaction with P-glycoprotein (Pgp), the mdr1 gene product and a mechanistic participant in multidrug resistance, underlies its activity as a modulator of MDR. Having previously shown that OC144-093 is not a substrate for CYP3A we first examined the effects of OC144-093 on paclitaxel metabolism in vitro. Using human liver microsomes, we have demonstrated that OC144-093 inhibited the CYP3A mediated metabolism of paclitaxel at high concentrations only (Ki = 39.8 +/- 5.1 microM, n=3). Pharmacokinetic results also show that an oral dose of OC144-093, co-administered with paclitaxel caused negligible disturbance of the pharmacokinetic profile for paclitaxel when injected intravenously. In contrast, AUC values were elevated approximately 1.5-fold in all groups treated orally with paclitaxel and OC144-093. Cmax was enhanced approximately 2-fold in the co-dosed group. These characteristics are consistent with Pgp blockade in the gut enhancing oral bioavailability. Elimination properties of paclitaxel were affected only upon multiple dosing of OC 144-093. These results warrant the further clinical assessment of OC144-093 as an MDR reversing agent.     

Genetic markers of predisposition to an aggressive course of chronic C hepatitis

The polymorphism of cytokine genes (11-1beta, IL-10, IL-6, and TGF-beta1) in patients with chronic C hepatitis and in healthy individuals was studied. The study found that the polymorphism of IL-1beta, IL-6, and TGF-beta1 may at least partially explain the genetic predisposition to an aggressive course of the disease with the development of terminal stage.