Efficacy and safety of the dipeptidyl peptidase-4 inhibitor sitagliptin compared with α-glucosidase inhibitor in Japanese patients with type 2 diabetes inadequately controlled on sulfonylurea alone (SUCCESS-2): a multicenter, randomized, open-label, non-inferiority trial.

We assessed the efficacy and safety of sitagliptin compared with α-glucosidase inhibitor (αGI) in 120 of Japanese patients with type 2 diabetes mellitus (T2DM) inadequately controlled on stable ≤2 mg/day glimepiride alone [mean hemoglobin A1c (HbA1c) 7.7%] by the randomized, active-controlled, non-inferiority trial. Patients were randomly assigned to receive additional sitagliptin or αGI for 24 weeks. The primary endpoint was change in HbA1c from baseline to week 12. After 12 weeks, sitagliptin reduced HbA1c by -0.44% (p < 0.001) relative to αGI. At 24 weeks, the reduction was almost identical between the groups (-0.091%, p = 0.47). Gastrointestinal disorders were more common with αGI than with sitagliptin, but only minor hypoglycaemia occurred in both groups at similar frequency. These data suggested that sitagliptin was not inferior to αGI for reduction of HbA1c in Japanese T2DM patients receiving glimepiride alone, and well tolerated with minimum risk of gastrointestinal symptoms and hypoglycaemia.

Relationships between serum (ZZ)-bilirubin, its subfractions and biliverdin concentrations in infants at 1-month check-ups.

In 150 infants, including those with breast milk jaundice, who were brought to our hospital for their 1-month check-ups, the serum concentrations of (ZZ)-bilirubin, its subfractions and biliverdin were measured by high-performance liquid chromatography and the relationships among them investigated. (ZZ)-Bilirubin was found to have the highest serum concentration, followed by (ZE)-bilirubin, accounting for 14.0 (geometric mean) % of (ZZ)-bilirubin. Biliverdin had a serum concentration of 0.95% of (ZZ)-bilirubin. There was only a small amount of total (di- and mono-) glucuronosyl bilirubin, 0.42% of (ZZ)-bilirubin. (ZE)-Bilirubin, (EZ)-bilirubin, (EZ)-cyclobilirubin. biliverdin, diglucuronosyl bilirubin and monoglucuronosyl bilirubin (C-8 and C-12) showed positive logarithmic correlations with (ZZ)-bilirubin (R2=0.16 or above, P<0.05). (ZE)-Bilirubin showed a significant positive logarithmic correlation with (ZZ)-bilirubin (R2=0.863, P<0.0001). Furthermore, (EZ)-cyclobilirubin, the most important photoisomer in phototherapy for neonatal hyperbilirubinaemia, was detected in very small amounts in approximately half of the neonates (84 of 150) when they were in conditions of only weak ambient light. The relationship between total glucuronosyl bilirubin and (ZZ)-bilirubin concentrations fitted a model of saturation kinetics of bilirubin UDP-glucuronosyltransferase.

Targeted disruption of the aromatase P450 gene (Cyp19) in mice and their ovarian and uterine responses to 17beta-oestradiol.

Aromatase P450 (CYP19) is an enzyme catalysing the conversion of androgens into oestrogens. We generated mice lacking aromatase activity (ArKO) by targeted disruption of Cyp19 and report the characteristic features of the ArKO ovaries and uteri as revealed by histological and biochemical analyses. ArKO females were totally infertile but there were as many developing follicles in their ovaries at 8 weeks of age as in wild-type ovaries. Nevertheless, no typical corpus luteum was observed in the ArKO ovaries. Electron microscopy revealed the presence of well-developed smooth endoplasmic reticulum, few lipid droplets and mitochondria with less organized tubular structures in the ArKO luteinized interstitial cells. These ultrastructural features were different from those of the wild-type interstitial cells, where there are many lipid droplets and mitochondria with well-developed tubular structures, characteristic of steroid-producing cells. When ArKO mice were supplemented with 17beta-oestradiol (E(2); 15 microg/mouse) every fourth day from 4 weeks of age for 1 month, increased numbers of follicles were observed in the ovaries as compared with those of untreated ArKO mice, although no typical corpus luteum was detectable. Ultrastructural analysis revealed the disappearance of the accumulated smooth endoplasmic reticulum in the luteinized interstitial cells after E(2 )supplementation. Transcripts of pro-apoptotic genes such as p53 and Bax genes were markedly elevated in the ArKO ovaries as compared with those of wild-type mice. Although E(2) supplementation did not cause suppression of the elevated expression of p53 and Bax mRNAs, it caused marked enhancement of expression levels of lactoferrin and progesterone receptor mRNAs in the uteri as well as increases in uterine wet weight. At 8 months of age, ArKO mice developed haemorrhages in the ovaries, in which follicles were nearly depleted, while age-matched wild-type females still had many ovarian follicles. Furthermore, macrophage-like cells were occasionally observed in the ArKO ovarian follicles. These results suggested that targeted disruption of Cyp19 caused anovulation and precocious depletion of ovarian follicles. Additionally, analysis of mice supplemented with E(2) demonstrated that E(2) apparently supports development of ovarian follicles, although it did not restore the defect in ovulation.

Cyclobilirubin formation by in vitro photoirradiation with neonatal phototherapy light.

BACKGROUND: The main mechanism of phototherapy for neonatal hyperbilirubinemia is the production and excretion of (EZ)- and (EE)-cyclobilirubin (4E,15Z- and 4E,15E-cyclobilirubin). Thus, the clinical efficacy of the light source for phototherapy must be evaluated by cyclobilirubin formation from (ZZ)-bilirubin in in vitro photoirradiation. METHODS: In the present study, we investigated the in vitro production pattern of bilirubin photoisomers by phototherapy light from the bilirubin-human serum albumin complex. RESULTS: No clear difference was found in the curves relative to (ZZ)-bilirubin and its photoisomers under aerobic and anaerobic conditions. The ratio of (EZ)-cyclobilirubin to (ZZ)-bilirubin increased proportionately to the dose of irradiating light and no photoequilibrium state was observed analogous to that found in configurational photoisomerization. The concentration of (EZ)- and (EE)-cyclobilirubin increased proportionately with the grade of the percentage decrease in A(460 nm) from 0 to 23%. With a percentage decrease in A(460 nm) of 23% or more, the cyclobilirubin concentrations reached a steady state. The reason for this appears to be that the concentration of (ZZ)-bilirubin, a substrate for photoisomers, dropped below 1 mg/100 mL. Biliverdin was produced only in trace amounts. However, the absorption at 520--700 nm increased after a percentage decrease in A(460 nm) of more than 23%. CONCLUSIONS: The results of the present study show that little bilirubin photooxidation occurred with in vitro aerobic photoirradiation. Before the concentration of cyclobilirubin reaches a steady state, it is theoretically valid to use the percentage decrease in A(460 nm) for the evaluation of the clinical efficacy of the light source.

cDNA sequence of human carbonic anhydrase-related protein, CA-RP X: mRNA expressions of CA-RP X and XI in human brain.

A full-length cDNA clone of human carbonic anhydrase-related protein (CA-RP) X was obtained and sequenced. The 2720 bp long cDNA sequence was predicted to encode a 328 amino acid polypeptide. The deduced amino acid sequence showed an overall similarity of 25-57% to other CA isozymes and the highest % similarity to a CA-RP XI. Similar to CA-RP XI, CA-RP X lacked two out of three zinc-liganded histidine residues, suggesting no biological activity of CA. Northern blot analysis demonstrated an approx. 2.8 kb transcript in the human brain and kidney. RNA dot blotting showed significant signals for CA-RP X and XI mRNA expressions in the adult total brain and almost all parts of the central nervous system, but no expression in the fetal brain. These results suggest that CA-RP X and XI play some role in human brain, especially in brain development.

Oestrogen at the neonatal stage is critical for the reproductive ability of male mice as revealed by supplementation with 17beta-oestradiol to aromatase gene (Cyp19) knockout mice.

Aromatase P450 (CYP19) is an enzyme responsible for the conversion of androgens to oestrogens. We generated CYP19 knockout (ArKO) mice by targeted disruption of Cyp19 and studied the role of oestrogens in male reproductive ability. Approximately 85% of ArKO males were unable to sire offspring. However, no obvious difference was found in testicular and epididymal weights, numbers of sperm in the epididymis or the ability of sperm to fertilize eggs in vitro between wild-type and ArKO males. An examination of mating behaviour demonstrated that ArKO males showed an impairment in mounting behaviour against sexually mature females. The inability of more than 90% of ArKO males to sire offspring was reversed by repeated subcutaneous injections of 17beta-oestradiol when initiated on the day of birth. The effects of 17beta-oestradiol on reproduction were concentration dependent and evident when supplementation was initiated on day 7, but not on day 15 after birth. These findings suggest that oestrogens acting during neonatal life are required for normal mating behaviour in adulthood.

A loss of aggressive behaviour and its reinstatement by oestrogen in mice lacking the aromatase gene (Cyp19).

Aromatase P450 (CYP19) is an enzyme responsible for conversion of androgens to oestrogens. We generated CYP19 knockout (ArKO) mice by targeting disruption of the CYP19 gene and observed that the ArKO males exhibited a complete loss of aggressive behaviour against intruder mice when examined using a resident-intruder paradigm. The defect in the behaviour of ArKO males was reinstated when the mice received supplements of 17beta-oestradiol soon after birth. Nevertheless, the cumulative duration of the behaviour displayed by the treated mice during the test period of 15 min was 19+/-10 s, which was much shorter than that displayed by wild-type males, 90+/-17 s. When the supplementation was started at 7 days after birth, the defect was not restored. These findings illustrate an absolute requirement for oestrogen during the neonatal stage of a male's life for the development of the potential for aggression observed in adulthood. Furthermore, the present study demonstrates that ArKO males are a useful model in which to investigate the neural mechanisms by which aggressive behaviour is controlled.

Unrecognized hepatic steatosis and non-alcoholic steatohepatitis in adjuvant tamoxifen for breast cancer patients.

Adjuvant tamoxifen has become the treatment of choice against estrogen receptor-positive breast cancer. Adverse effects are rarely observed and since symptoms of hepatic steatosis, non-alcoholic steatohepatitis and cirrhosis are usually negligible, such effects are not well characterized despite large cohort studies of adjuvant tamoxifen. This issue remains to be systematically studied. The present study consisted of 136 breast cancer patients treated with or without tamoxifen. Patients had laboratory tests once each month and underwent abdominal computed tomography (CT) annually for 5 years. The extent of hepatic steatosis was assessed by CT as the liver/spleen ratio. While receiving adjuvant tamoxifen, 40 of 105 patients developed hepatic steatosis (liver/spleen ratio <0.9) without obvious changes in body mass index. Twenty-one had a liver spleen ratio of <0.5, whereas none of the 31 patients treated without tamoxifen had a ratio <0.9 or <0.5 (p<0.0001 and p<0.0001, respectively). Hepatic steatosis was recognized in 35 of the 40 patients within the first 2 years of receiving adjuvant tamoxifen and 21 of the 40 had increased transaminase levels. Liver biopsy revealed NASH in 6 of 7 patients among the 21 with a liver/spleen ratio of <0.5. A subset of individuals given adjuvant tamoxifen developed progressive hepatic steatosis without significant changes in the body mass index. We suggest a liver/spleen ratio of <0.5 as a criterion upon which liver biopsy should be recommended since NASH frequently occurred in such patients.

Formation of propentdyopents and biliverdin, oxidized metabolites of bilirubin, in infants receiving oxygen therapy.

BACKGROUND: Bilirubin has antioxidative effects. When bilirubin reacts with reactive oxygen species, oxidized metabolites of bilirubin are formed, such as biliverdin and propentdyopents. A decrease in serum bilirubin concentration and an increase in serum and urinary oxidized metabolites of bilirubin may indicate the protective action of bilirubin against reactive oxygen species. METHODS: In the in vitro study, we measured the oxidative products of bilirubin formed through the action of O2- by the xanthine-xanthine oxidase system, either as free bilirubin or bilirubin-human serum albumin complex. In the clinical investigation, serum concentrations of (ZZ)-bilirubin (4Z, 15Z-bilirubin), the subfraction and biliverdin, and urinary propentdyopent absorption, were measured in blood and urine samples, respectively, collected from 30 5-day-old neonates with birth weights of 1500-3624 g who had been hospitalized at the Ehime Prefectural Hospital and who had not undergone phototherapy. RESULTS: In the in vitro study, a significant formation of propentdyopents was observed in aqueous solution. A statistically significant correlation was found between serum (ZZ)-bilirubin concentration and serum biliverdin concentration (r = 0.82, P < 0.0001), but not between serum (ZZ)-bilirubin concentration and urinary propentdyopent absorption. Serum (ZZ)- and serum (ZE)-bilirubin and biliverdin concentrations, and urinary propentdyopent absorption were compared between the groups with and without oxygen therapy. No significant differences were found in serum (ZZ)-bilirubin, serum (ZE)-bilirubin and biliverdin concentration, urinary propentdyopent absorption, serum biliverdin/serum (ZZ)-bilirubin, or urinary propentdyopent absorption/serum (ZZ)-bilirubin. Neither a decrease in serum bilirubin concentration nor an increase in serum biliverdin concentration and urinary propentdyopent absorption after oxygen therapy were demonstrated in the present study. CONCLUSIONS: In the in vitro study, we demonstrated for the first time that propentdyopents were produced from (ZZ)-bilirubin by the xanthine-xanthine oxidase system but biliverdin was not. In the in vivo study, serum biliverdin concentration and urinary propentdyopent absorption seem to have a different relationship to serum (ZZ)-bilirubin concentration in sick and early neonates.

cDNA sequence, mRNA expression, and chromosomal localization of human carbonic anhydrase-related protein, CA-RP XI.

A full-length cDNA clone of a human carbonic anhydrase-related protein, CA-RP XI encoded by CA11, was obtained and sequenced. The cDNA sequence was 1475 bp long and predicted to encode a 328-amino acid polypeptide with a molecular mass of 36200 Da. The deduced amino acid sequence of CA-RP XI showed an overall similarity of 42-53% to the active site residues of other active CA isozymes; however, it lacked three zinc-binding histidine residues, raising questions regarding its CA catalytic activity. Northern blot analysis demonstrated strong expression of an approx. 1.5 kb transcript in the human brain, particularly in the cerebellum, cerebral cortex, and putamen. A single copy of the CA11 gene was localized to the human chromosome 19q13.2-3. These results suggest that CA-RP XI plays a general role in the human central nervous system.

Mitochondrial abnormalities in selenium-deficient myopathy.

We report a man who developed selenium-deficient myopathy during long-term parenteral nutrition. Muscle biopsy showed marked mitochondrial depletion in the deep sarcoplasm and enlarged mitochondria at the periphery mainly in type 2 fibers. Muscle weakness improved gradually after the second course of selenium supplementation. The peculiar mitochondrial abnormalities in muscle fibers appear to play a key role in the pathogenesis of selenium-deficient myopathy.

Long-latency event-related potentials in acute hepatitis patients with severe coagulopathy.

In 19 acute hepatitis patients with severe coagulopathy who were fully alert and oriented without any changes of mood or behavior, the P300 latency and the arterial blood ketone body ratio (KBR) were assessed as predictors of fulminant hepatitis. All 5 patients developing fulminant hepatitis had a corrected P300 latency longer than 345 msec and 4 of them had a KBR below 0.6. There was a significant negative correlation between the KBR and the blood ammonia level and between the KBR and the corrected P300 latency, while there was a positive correlation between the blood ammonia level and the corrected P300 latency. These data suggest that hepatic encephalopathy develops when loss of hepatic detoxifying activity allows toxic substances to reach the brain and induce cerebral edema. Our findings also suggest the clinical value of using the P300 latency combined with the KBR as predictors of fulminant hepatitis.

Wavelength dependence of the geometric and structural photoisomerization of bilirubin bound to human serum albumin.

The two quantitatively important photoisomers in bilirubin metabolism during phototherapy are (ZE)-bilirubin and (EZ)-cyclobilirubin. We describe in vitro studies on the wavelength dependence for the geometric (delta 4Z, delta 15Z----delta 4Z, delta 15E) and structural (endovinyl cyclization) photoisomerization of bilirubin bound to human serum albumin by a high performance liquid chromatography method. For the geometric photoisomerization from (ZZ)-bilirubin to (ZE)-bilirubin, the most effective wavelength in vitro was 410 nm. For the structural photoisomerization, green light at 510 nm is the most efficient for causing cyclization of (ZZ)-bilirubin to (EZ)-cyclobilirubin via (EZ)-bilirubin and this may depend on a larger cross-section of (EZ)-bilirubin than (ZZ)-bilirubin in this spectral region and/or on a larger quantum yield for cyclization than geometric photoisomerization.

The effect of bilirubin photoisomers on unbound-bilirubin concentrations estimated by the peroxidase method.

Unbound bilirubin is oxidized to nearly colourless substances in the presence of H2O2 or ethyl hydroperoxide and horseradish peroxidase. To predict the risk of kernicterus (degenerated yellow pigmentation of nerve cells), this principle has been widely utilized for estimating the concentration of unbound bilirubin in hyperbilirubinaemic serum. However, the serum contains polar geometric photoisomers of bilirubin. Therefore, to clarify the effect of bilirubin photoisomer concentrations on unbound-bilirubin concentration, the concentration of bilirubin and its photoisomer and of unbound bilirubin in samples obtained from experiments in vivo and in vitro were simultaneously and individually estimated by h.p.l.c. and the peroxidase method. During photoirradiation, both in vivo and in vitro, the serum polar (ZE)-bilirubin IX alpha concentration increased remarkably, but unbound-bilirubin values were not affected at all. However, during experiments in vitro, unbound bilirubin concentrations increased only when concentrations of the rather polar (EZ)- and (EE)-cyclobilirubin IX alpha increased considerably in a human serum albumin-bilirubin solution irradiated with blue light. Thus it is concluded that unbound-bilirubin concentrations, and consequently the initial rate of the peroxidase reaction, is not accelerated by the increase in either (ZE)-bilirubin or (EZ)-cyclobilirubin concentration within the clinically observed range.

Metabolism of bilirubin and its photoisomers in newborn infants during phototherapy.

Bilirubin and its photoisomers in the biological fluids of a hyperbilirubinaemic newborn infant before and during phototherapy were analyzed by a recently improved HPLC method. In the serum, the percentages of (EZ)- and (ZE)-bilirubin in the total bilirubin concentration before phototherapy were approximately 10% and on average increased over 1.5-fold at 2 h after initiation of phototherapy. The percentage of the (EZ)-cyclobilirubin in the serum bilirubin was under 1%. In the bile, the mean concentration of (ZZ)-bilirubin, derived mainly from (ZE)-bilirubin, nearly tripled during phototherapy. The (EZ)-cyclobilirubin concentration in the bile was very low before phototherapy, increased nearly ten-fold at 3 h after initiation of phototherapy, and was 5- to 6-fold as high as that of (ZZ)-bilirubin. In the urine, upon exposure to light, the urinary concentration of (EZ)-cyclobilirubin is apparently equivalent to half of the biliary concentration of (ZZ)-bilirubin and one-fifth of that of (EZ)-cyclobilirubin. It was concluded that during phototherapy of neonatal hyperbilirubinaemia the structural photoisomer [(EZ)-cyclobilirubin] predominates considerably over the geometric photoisomer [(ZE)-bilirubin].

Wavelength-dependence of the relative rate constants for the main geometric and structural photoisomerization of bilirubin IX alpha bound to human serum albumin. Demonstration of green light at 510 nm as the most effective wavelength in photochemical changes from (ZZ)-bilirubin IX alpha to (EZ)-cyclobilirubin IX alpha via (EZ)-bilirubin.

The kinetics for the quantitatively important reaction: (Formula: see text) that is, the photochemical interconversion between bilirubin and its geometric and structural photoisomers bound to human serum albumin in aqueous solution when various wavelengths of monochromatic light were used, were assayed by h.p.l.c. In order to clarify the wavelength-dependence of the relative rate constants in the individual steps, a light-source with a half-bandwidth of 10 nm was used at increments of 20 nm, in the range from 410 nm to 550 nm. We describe for the first time studies on the wavelength-dependence of rate constants in geometric and structural photoisomerization reactions in vitro of (ZZ)-bilirubin or (EZ)-bilirubin bound to human serum albumin, especially the relative rate constants of cyclization of (EZ)-bilirubin into (EZ)-cyclobilirubin. Because studies in vitro have demonstrated that the wavelengths from 350 to 450 nm are mutagenic, the results obtained indicated that the safest and ideal light-source for phototherapy is green light of 510 nm, which keeps (ZE)-bilirubin concentrations as low as possible, as shown by a maximal value of k2 at 510 nm and a relatively low value of k1 at 510 nm. This light-source still ensures the substantial absorption of (ZZ)-bilirubin, which is the precursor of (EZ)-bilirubin, the intermediate in (EZ)-cyclobilirubin formation and, furthermore, as shown by the maximal value of k5 and a considerable value of k4 at 510 nm, promotes the cyclization of (EZ)-bilirubin derived from (ZZ)-bilirubin even though k3 at 510 nm also shows a peak value.

Biliary and urinary excretion rates and serum concentration changes of four bilirubin photoproducts in Gunn rats during total darkness and low or high illumination.

On cycled exposure of Gunn rats to total darkness and low and high illumination, biliary excretion rates of (EZ)- and (ZE)-bilirubin and (EZ)-cyclobilirubin increased up to approx. 10-fold from the mean basal values of 1.2 and 0.2 microgram/h to the mean maximum values of 25.2 and 4.2 micrograms/h respectively, and at the same time those of (EE)-bilirubin and (EE)-cyclobilirubin also increased, but at very much lower rates than those of the first-mentioned two. During the low illumination only (EZ)- and (ZE)-bilirubin and (EZ)-cyclobilirubin appeared in the urine; during the high illumination (EE)-bilirubin and (EE)-cyclobilirubin also appeared, showing a similar excretion pattern to that observed in the bile, but the total urinary excretion rates were lower than the total biliary excretion rates. The serum bilirubin concentrations fell gradually to lower values, accompanied by an increment in (EZ)- and (ZE)-bilirubin, but (EZ)-cyclobilirubin was not detected. It is concluded that during phototherapy the predominant pathway for the removal of bilirubin from the body in the Gunn rat is by biliary excretion of the geometric photoisomers (EZ)- and (ZE)-bilirubin, derived from Z----E isomerization, and the structural photoisomer (EZ)-cyclobilirubin, formed from intramolecular endo-vinyl cyclization.

Significance of the endo-vinyl group of bilirubin in photochemical reactions.

In photochemical experiments on bilirubin III alpha (no endo-vinyl group), IX alpha (one endo-vinyl group) and XIII alpha (two endo-vinyl groups) and in the photochemical, thermal and catalytical reversion of their photoproducts under anaerobic conditions, much more instability and complexity of photoproducts of bilirubin XIII alpha were observed than for those of bilirubin IX alpha or III alpha. On the basis of present and previous results of photochemical experiments in vitro and the fact that large amounts of (EZ)-cyclobilirubin IX alpha appear in the bile during phototherapy of neonatal hyperbilirubinaemia [Onishi, Kawade, Itoh, Isobe & Sugiyama (1980) Biochem. J. 190, 527-532], it is concluded that the endo-vinyl group plays a crucial role in the photochemical reaction of bilirubin IX alpha. On reversed-phase high-pressure liquid chromatography of photoisomers, it was found that the retention times of geometric isomers and E-cyclized structural isomers were shortened compared with those of Z-isomer and E-isomer, respectively, as precursor substances.