Yokoyama studies

H. Mitsuda, K. Yasumoto, and K. Yokoyama, Studies on the free radical in amino-carbonyl reaction, Agric. Biol. Chem., 1965, 29, 751-756. 

There have been several attempts to relate mobilities to ionization or oxidation potentials (Enokida et al., 1990 Scott et al., 1990 Kanemitsu et al., 1991, 1992 Kitamura and Yokoyama, 1991). Scott et al. studied a series of hydrazone compounds in a polyarylate. The oxidation potentials of the donor compounds varied from 0.53 to 1.04 V. The results showed that the zero-field mobilities increase with increasing oxidation potential. In contrast, Enokida et al. investigated a series of butadiene, hydrazone, and oxadiazole compounds doped into a PC and concluded that the mobilities increased with decreasing ionization potential. Kitamura and Yokoyama studied a series of hydrazone compounds in a PC and concluded that the mobilities were independent of the ionization potential. While the reason for these discrepancies is not clear, it should be noted that the study of Scott and coworkers involved zero-field... 

Furthermore, a melanocyte line that has reverted in culture from albino to wild type has restored the cysteine codon at position 85 (Jackson and Bennett, 1990). In vivo studies (see below) proved that the c-locus encodes tyrosinase and showed that expression of a tyrosinase minigene rescues the albino phenotype (Yokoyama et al., 1990 Tanaka et al., 1990 Beermann et al., 1990). 

Several studies provide information regarding body weight effects of lead in animals (Dieter et al. 1993 Freeman et al. 1996 Hamilton and O Flaherty 1995 Hayashi et al. 1993 Kala and Jadhav 1995a Skoczynska et al. 1993 Yokoyama and Araki 1992). Most of these studies were conducted in rats, are of intermediate-duration exposure, and used various media to administered the lead. 

In intermediate-duration studies in which lead acetate was administered in the drinking water, the lowest LOAEL was approximately 77 mg lead/kg/day for a 15% decrease in final body (Yokoyama and Araki 1992). Since this was the only dose level tested, it is possible that the true LOAEL was actually lower than 77 mg/kg/day. However, a different 90-day study, also with lead acetate in drinking water reported a NOAEL for body weight of approximately 38 mg lead/kg/day (Kala and Jadhav 1995a). Two studies of similar design in which lead was administered mixed in the food provided conflicting results. 

Yokoyama K, Araki S. 1986. Alterations in peripheral nerve conduction velocity in low and high lead exposure An animal study. Ind Health 24 67-74. 

The reaction of //-protected dehydroalanine methyl esters (e.g. 56, 59) with other indoles 58 can also be effected to give the corresponding dehydrotryptophans 60, invariably as the Z-isomers [81]. Murakami, Yokoyama and co-workers also studied oxidative couplings of acrylates, acrylonitrile, and enones with 2-carboethoxyindole, 1-benzylindole, and l-benzyl-2-carboethoxyindole and PdCfe and CuCk or Cu(OAc) 2 to give C-3 substitution in 50-84% yields [82, 83]. 

Yokoyama, C. and Misono, M. Catalytic reduction of nitrogen oxides by propene in the presence of oxygen over cerium ion-exchanged zeolites II. Mechanistic study of roles of oxygen and doped metals. J. Catal, 1994, Volume 150,9-17. 

Nakuma K, Uemura K, Konno T, Yanaka N, Yokoyama I (1979) Studies on anticancer treatment with an anti-cancer drug injected into the ligated hepatic artery for liver cancer. Nichidoki Iho 24 675... 

T. Takeda, K. Makita, S. Ishikawa, K. Kaneda, K. Yokoyama, K. Amaha, Uptake and elimination of sevoflurane in rabbit tissues - an in vivo magnetic resonance spectroscopy study. Can. J. Anaesth. 47 (2000) 579-584. 

Micellar diameter and size polydispersity can be obtained directly in water or in an isotonic buffer by DLS. DLS can also provide some information on the sphericity of polymeric micelles (Kataoka et al., 1996 Nagasaki et al., 1998). Ultracentrifugation velocity studies are sometimes performed to assess the polydispersity of polymeric micelles (Yokoyama et al., 1994 Hagan et al., 1996). 

Kwon and Kataoka (1995) summarized earlier studies ofthe pharmacokinetics and disposition polyethylene oxid -aspartate)-doxorubicin conjugates (PEGAsp-DOX) (Yokoyama et al.,... 

There are numerous accounts in the literature of increased bioavailability in animals when changing the solid state. Kato and Kohetsu (1981) showed that form II amobarbital is more rapidly absorbedn vivo than form I. Dissolution rate experiments in water at(3"Showed a 1.6 times faster dissolution ratei vitro for form II compared to form I. Yokoyama et al. (1981) found that form III of 6-mercaptopurine was 1.5 times as bioavailable in rabbits as form I. It was six to seven times as soluble as the form I polymorph in studies by Kuroda et al. (1982). Kokubu et al. (1987) examined the therapeutic effect of different polymorphs of cimetidine in inhibition of ulcers in the rat. Pharmacokinetic studies found that form C was 1.4-1.5 times as bioavailable as forms A and B. This translated into a greater protection against stress ulceration, as shown in Table 19.4. The effec of form C was signiLcant compared to forms A, B, and D, which were all equivalent. 

Kuroda, T, Yokoyama, T, Umeda, T, Matsuzawa, A, Kuroda, K, and Asada, S. (1982). Studies on drug nonequivalence. XI. Pharmacokinetics of 6-mercaptopurine polymorphs in raBtofep. Pharm. 

Lu, C.-S., Kashima, K., Daa, T., Yokoyama, S., Yanagisawa, S., and Nakayama, I. 2000. Immuno-histochemical study of the distribution of endogenous biotin and biotin-binding enzymes in ductal structures of sahvary gland tumors. J. Oral Pathol. Med. 29 445-151. 

Based on sequence comparison, the eubacterial V-type ATPase is a product of horizontal gene transfer from the Archaea. Much of the information about the subunit arrangement in the eubacterial A/V-type—like ATPase comes from studies with the enzymes from C. fervidus and T. thermophilus (Boekema et al, 1997, 1999 Ubbink-Kok et al, 2000 Yokoyama et al, 2003a). A recent 3D reconstruction of the A/V- ATPase from T. thermophilus (Bernal and Stock, 2004) revealed the structural similarity to both the eukaryotic V-ATPase (Domgall et al., 2002 Wilkens et al., 2004, 2005) and the archaeal A-ATPase (Coskun et al., 2004a,b). The x-ray crystal structure for the C-subunit of the bacterial A/V-like ATPase has been reported recently (Iwata et al, 2004). The C-subunit of the bacterial V-like ATPase shows limited but significant sequence homology to the cZ-subunit of the eukaryotic V-ATPase. 

Takahashi, T. and Yokoyama, W. (1954). Physico-chemical studies on the skin and leather of marine animals - XII. The content of hydroxyproline in the collagen of different fish skins. Bulletin of the Japanese Society of Scientific Fisheries 20, 525-529. 

Yokoo H, Goldstein M, Meller E (1988) Receptor reserve at striatal dopamine receptors modulating the release of [3H] dopamine. Eur J Pharmacol 155 323-7 Yokoyama H, Onodera K, Maeyama K, Sakurai E, Iinuma K, Leurs R, Timmerman H, Watanabe T (1994) Clobenpropit (VUF-9153), a new histamine H3 receptor antagonist, inhibits electrically induced convulsions in mice. Eur J Pharmacol 260 23-8 Yoshimoto R, Miyamoto Y, Shimamura K, Ishihara A, Takahashi K, Kotani H, Chen AS, Chen HY, Macneil DJ, Kanatani A, Tokita S (2006) Therapeutic potential of histamine H3 receptor agonist for the treatment of obesity and diabetes mellitus. Proc Natl Acad Sci USA, in press Young CS, Mason R, Hill SJ (1988) Studies on the mechanism of histamine-induced release of noradrenaline and 5-hydroxytryptamine from slices of rat cerebral cortex. Biochem Pharmacol 37 2799-2805... 

Yokoyama et al. [4] used ion exclusion chromatography and continuous hydride atomic absorption spectrometry to study arsenic speciation in geothermal waters. Arsenic was determined in the range 0.01 to 10 mg IT1. 

Yokoyama and coworkers investigated the discolouration of titanylphthalocyanine 60, and related porphyrins by silyl radicals derived from methylphenylpolysilane by molecular orbital methods60. Calculated values of AN, the index derived from the hard and soft acids and bases concept was determined from HF/3-21G calculated ionization potentials, electron affinities, and HOMO and LUMO orbital energies of the systems of interest. These studies predict that PhMe2Si should donate an electron readily to 60 to form 60 (equation 18). This prediction is of direct relevance to observations that irradiation of titanylphthalocyanine-coated methylphenylpolysilane films leads to discolouration of the film60. 

A method for the direct observation of extracorporal thrombus formation has been introduced by Rowntree and Shionoya (1927). These first studies could provide evidence that anticoagulants like heparin and hirudin do inhibit thrombus development in arteriovenous shunts. Since today, the A-V-shunt thrombosis models have been often used to evaluate the antithrombotic potential of new compounds in different species including rabbits (Knabb et al. 1992), rats (Hara et al. 1995), pigs (Scott et al. 1994), dogs and cats (Best et al. 1938), and non-human primates (Yokoyama et al. 1995). 

The Eva2 photoisomerization is also involved in heterocyclic fulgides and their derivatives. The quantum yields have been measured for different reactions. Yokoyama e/a/.,7,8,44,45 Uchida el al.,75 and Yokoyama and Kurita104 very recently studied the EfiZ isomerization of fulgides in detail. 

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