Effect of Avemar--a fermented wheat germ extract--on rheumatoid arthritis. Preliminary data.

OBJECTIVE: To investigate the effect of the fermented wheat germ extract (Avemar)in patients with severe rheumatoid arthritis (RA). METHODS: Fifteen female RA (Steinbrocker II-III) patients, who had unsuccessfully tried two different DMARD treatments, were enrolled in an open-label, 1-year long, pilot clinical study. DMARD and steroid therapies were recorded and continued. All patients received Avemar as additional therapy. For measurement of efficacy the Ritchie Index, the Health Assessment Questionnaire (HAQ) and the assessment of morning stiffness were applied. Patients were evaluated at baseline, 6 and 12 months. For statistical analyses the Wilcoxon test was used. RESULTS: At both 6 and 12 months, Ritchie index, HAQ and morning stiffness showed significant improvements compared with the baseline values. Dosages of steroids could be reduced in about half of the patients. No side effects of Avemar were observed. CONCLUSION: Supplementation of standard therapies with a continuous administration of Avemar is beneficial for RA patients.

Testing the efficacy of fermented wheat germ extract against Mycoplasma gallisepticum infection of chickens.

The effect of fermented wheat germ extract (FWGE, Immunovet-HBM) was studied in chickens challenged with Mycoplasma gallisepticum. Ninety M. gallisepticum- and M. synoviae-free 3-wk-old chickens were exposed to aerosol infection of M. gallisepticum. One group (30 birds) was treated with FWGE, a second group with tiamulin, and a third group was untreated. The fourth group was exposed to PBS aerosol as a negative control. On d 9, all chickens were slaughtered and examined for the presence of gross and histological lesions, the presence of the challenge strain in the organs and specific antibodies in the serum. Body weight gains and feed conversion rates were recorded. In the groups treated with FWGE and with tiamulin, the chickens remained clinically healthy: their BW gains were 441.7 g and 446.8 g, respectively. Feed conversion ratios were 1.72 and 1.71 for FWGE- and tiamulin-treated birds, respectively. Control birds had BW gain of 480.8 g, and feed conversion ratio of 1.78. The numbers of birds with gross lesions (15 and 11, respectively) and lesion scores (25 and 25, respectively) of the FWGE- and tiamulin-treated groups were significantly lower than in the infected untreated group (25 birds, lesion score of 190). No mycoplasma was reisolated from brain, liver, spleen, heart, or kidneys of the FWGE-treated birds, and the number of mycoplasma isolations from the respiratory tract samples was less frequent (10) than from the infected untreated group (64). In addition, 35 samples from other internal organs were also positive. Twenty percent of the birds treated with FWGE showed serological response with a 5.0% reaction score, whereas in the infected untreated group, 83.3% of birds were reactors, with a 62.5% reaction score.

Caldesmon: binding to actin and myosin and effects on elementary steps in the ATPase cycle.

The actin binding protein caldesmon inhibits the actin-activation of myosin ATPase activity. The steps in the cycle of ATP hydrolysis that caldesmon could inhibit include: (1) the binding of myosin to actin, (2) the transition between any two actin-myosin states and (3) the distribution between inactive and active states of actin. The analysis of these possibilities is complicated because caldesmon binds to both myosin and actin and because each caldesmon molecule binds to several actin monomers. This paper reviews procedures for analysing these interactions and summarizes current information on the stability and dynamics of the interaction of caldesmon with actin and myosin. Possible effects of caldesmon on transitions within the ATPase cycle of actomyosin are also discussed.

Adenosine 5'-(gamma-thiotriphosphate): an ATP analog that should be used with caution in muscle contraction studies.

The slowly hydrolyzed ATP analog adenosine 5'-(gamma-thiotriphosphate) (ATP gamma S) has been used in many studies of the muscle motor protein myosin in order to form a stable "weak binding" state analogous to the actin-S1-ATP complex However, the results from studies using ATP gamma S do not always agree with the results of experiments using ATP. The binding of myosin subfragment-1-ATP gamma S to actin has now been studied in some detail to determine its relationship to the actin-S1-ATP state. The binding of myosin subfragment-1-ATP gamma S to actin-troponin-tropomyosin is similar in affinity to the binding of myosin subfragment-1-ATP. Like myosin subfragment-1-ATP, the binding is not Ca(2+)-dependent, and most importantly, myosin subfragment-1-ATP gamma S does not stabilize the active configuration of actin-troponin-tropomyosin. Thus, myosin subfragment-1-ATP gamma S is an analog of myosin subfragment-1-ATP but must be used with caution for two reasons: (1) The binding of ATP gamma S to regulated actomyosin subfragment-1 is Ca(2+)-sensitive, and errors can be made in the interpretation of results if proteins are not fully saturated with nucleotide and a mixture of weak and strong binding states is present. (2) At the high concentrations of myosin subfragment-1 used in some experiments, significant amounts of ADP may form.(ABSTRACT TRUNCATED AT 250 WORDS)

Metabolism and pharmacokinetics of the anti-varicella-zoster virus agent 6-dimethylaminopurine arabinoside.

The metabolism of 6-dimethylaminopurine arabinoside (ara-DMAP), a potent inhibitor of varicella-zoster virus replication in vitro, was studied in rats and cynomolgus monkeys. Rats dosed intraperitoneally or orally with ara-DMAP excreted unchanged ara-DMAP and one major metabolite, 6-methylaminopurine arabinoside (ara-MAP), in the urine. They also excreted allantoin and small amounts (less than 4% of the dose each) of hypoxanthine arabinoside (ara-H) and adenine arabinoside (ara-A). The relative amount of each urinary metabolite excreted remained fairly constant for intraperitoneal ara-DMAP doses of 0.3 to 50 mg/kg of body weight. Rats pretreated with an inhibitor of microsomal N-demethylation, SKF-525-A, excreted more unchanged ara-DMAP and much less ara-MAP than did rats given ara-DMAP alone. Rats pretreated with the adenosine deaminase inhibitor deoxycoformycin excreted more ara-MAP and much less ara-H and allantoin. ara-MAP was shown to be a competitive alternative substrate inhibitor of adenosine deaminase (Ki = 16 microM). Rats given ara-DMAP intravenously rapidly converted it to ara-MAP and purine metabolism end products; however, ara-A generated from ara-DMAP had a half-life that was four times longer than that of ara-A given intravenously. In contrast to rats, cynomolgus monkeys dosed intravenously with ara-DMAP formed ara-H as the major plasma and urinary end metabolite. Rat liver microsomes demethylated ara-DMAP much more rapidly than human liver microsomes did. ara-DMAP is initially N-demethylated by microsomal enzymes to form ara-MAP. This metabolite is further metabolized by either adenosine deaminase, which removes methylamine to form ara-H, or by microsomal enzymes, which remove the second methyl group to form ara-A.

Glucuronidation of 3'-azido-3'-deoxythymidine catalyzed by human liver UDP-glucuronosyltransferase. Significance of nucleoside hydrophobicity and inhibition by xenobiotics.

The enzymatic glucuronidation of 3'-azido-3'-deoxythymidine (AZT) catalyzed by human liver microsomal UDP-glucuronosyltransferase (EC 2.4.1.17, UDPGT) was inhibited by a number of nucleoside analogs. The inhibitory potency of these nucleoside analogs correlated with their hydrophobicity (r2 = 0.90, N = 13). Since similar results were obtained with solubilized UDPGT (r2 = 0.87, N = 7), the affinity of the nucleosides for UDPGT was probably being assessed rather than the ability of the compounds to access the membrane-bound enzyme. Three homologous inhibitors, 3'-azido-2',3'-dideoxyuridine (AzddU), 5-ethyl-AzddU, and 5-propyl-AzddU, were also studied as substrates of UDPGT. The substrate efficiency (Vmax/Km) of these three compounds and AZT also correlated with their hydrophobicity (r2 = 0.94). Sixteen drugs that are structurally unrelated to nucleosides also inhibited the glucuronidation of AZT. The mechanism of inhibition was competitive for seven compounds tested. Ki values were estimated from Dixon plots for nine other less soluble inhibitors; their mechanism of inhibition was assumed to be competitive. Since the peak physiological drug concentrations of the tested inhibitors are considerably less than their Ki values, none of these compounds are expected to strongly inhibit AZT glucuronidation in humans. However, the rank order of these drugs with respect to their inhibitory potential is probenecid greater than chrloramphenicol greater than naproxen greater than phenylbutazone much greater than other drugs tested.

Mechanistic stoichiometry of mitochondrial oxidative phosphorylation.

P/O ratios of rat liver mitochondria were measured with particular attention to systematic errors. Corrections for energy loss during oxidative phosphorylation were made by measurement of respiration as a function of mitochondrial membrane potential. The corrected values were close to 1, 0.5, and 1 at the three coupling sites, respectively. These values are consistent with recent measurements of mitochondrial proton transport.

Glucuronidation of 3'-azido-3'-deoxythymidine: human and rat enzyme specificity.

Since preclinical studies indicated that 3'-azido-3'-deoxythymidine (AZT, zidovudine, Retrovir, BW A509U), a potent anti-HIV agent, is not metabolized extensively in rats, rabbits, mice, guinea pigs, cats, or dogs, the extensive biotransformation of AZT observed in humans was not expected. On average, approximately 75% of an oral AZT dose is recovered in human urine as a single metabolite while only 14-18% of the dose is recovered unchanged. Ultraviolet, infrared, nuclear magnetic resonance, and mass spectra and enzymatic degradation characterized the isolated major metabolite as a 5'-O-glucuronide (3'-azido-3'-deoxy-5'-beta-D-glucopyranuronosylthymidine, GAZT), a very unique nucleoside metabolite. These observations suggest that UDP-glucuronosyltransferase (UDPGT), EC2.4.1.17, mediates the in vivo biotransformation of AZT to GAZT. Since glucuronidation is one of the major conjugation reactions involved in the metabolic conversion of xenobiotics to more polar, water-soluble metabolites, it is an important detoxification pathway in humans. Therefore, it is important to understand the enzymatic basis for the discrepancy between metabolism of AZT in laboratory mammals and humans. This is especially relevant in light of the use of laboratory mammals to predict the metabolism of novel pharmaceutical agents in humans. The study presented herein confirms that liver UDPGT does catalyze the glucuronidation of AZT and that the higher substrate efficiency of AZT with human enzyme compared to rodent enzyme may account for metabolic differences observed in vivo.