Role of bilirubin as an antioxidant in an ischemia-reperfusion of rat liver and induction of heme oxygenase

The anti-oxidative effect of bilirubin was investigated in an ischemia-reperfusion model of rat liver. The rat portal vessel and liver artery were ligated with a vascular clip, and after reperfusion the urine was collected at intervals. The amount of biopyrrins, the oxidative metabolites of bilirubin, in rat urine reached a maximum 4 hours after reperfusion. Biotripyrrin-a and -b which are biopyrrins isolated from human urine were included in urinary bilirubin oxidative metabolites of rats after reperfusion. The hepatic mRNA level of heme oxygenase-1 (HO-1), the rate limiting enzyme of bilirubin biosynthesis, reached a maximum after 4 hours. Furthermore, the hepatic activity of HO began to rise 4 hours after treatment and remained high until 24 hours posttreatment. These findings suggest that bilirubin acts as a physiological antioxidant in vivo in ischemia-reperfusion and that bilirubin biosynthesis is evoked by oxidative stress.

[Massive hemoptysis caused by disruption of a bronchial aneurysm diagnosed by microscopic examination of the resected lung]

A 29-year-old woman in the 6th month of pregnancy was admitted to our hospital because of repeated hemoptysis after an acute respiratory infection. Fiberoptic bronchoscopy revealed a polypoid lesion at the orifice of the right B3 bronchus and bleeding around the lesion. Bronchial arteriography showed no abnormalities. Transcatheter embolization was unsuccessful. Therefore, a right upper lobectomy was done. Microscopical examination showed a mass of coagulated blood on the mucosal surface of the wall of the B3 bronchus, and a bronchial artery running toward the mucosal surface was seen underneath. The mass was thought to be the polypoid lesion seen during bronchoscopy. Serial sections showed a bronchial aneurysm 1 mm in diameter that had ruptured into the bronchial lumen. Several bronchial arteries were located in the propria mucosa in other bronchial segments, as observed in the B3 bronchus, but no other focus of bleeding was identified. Some cases of hemoptysis of unknown cause may result from similar histological alterations.

Attention-induced neuronal activity in the monkey somatosensory cortex revealed by pupillometrics

Detection of a sensory stimulus is facilitated when attention is directed towards the stimulus source. Neuronal substrates for this psychological effect were studied in monkeys performing an attention-demanding task, by simultaneous recording of neuronal activity and pupillary dilation as an indicator of attentive state. We found that neurons in the postcentral somatosensory cortex (SI) started to discharge concurrent with the pupil dilation onset which occurred well before the somatosensory stimulus. Neuronal firing rates were positively correlated with the degree of dilation, suggesting that the SI neural activity is under the direct influence of the attentional process.

Mild hypoxia induces hypertrophy of cultured neonatal rat cardiomyocytes: a possible endogenous endothelin-1-mediated mechanism

Hypoxic or ischemic stresses on cardiomyocytes may cause a variety of compensatory responses including cell hypertrophy. In this study, we examined whether hypoxia induces hypertrophy of cardiomyocytes in vitro and whether hypoxia-induced hypertrophy is inhibited by an endothelin A receptor antagonist (BQ123). Neonatal rat cardiomyocytes were cultured in 10% O2/85% N2/5% CO2 or 95% N2/5% CO2 to produce a mild or severe hypoxic condition, respectively. Cardiomyocytes exposed to severe hypoxia revealed degenerative morphological changes and a decrease of cell number, suggesting the toxicity of severe hypoxia on cardiomyocytes. In contrast, cardiomyocytes with mild hypoxia developed hypertrophy; cell surface area of cardiomyocytes as evaluated by an image analyser system increased by 1.6-fold over control after 48 h. [3H]leucine incorporation into the cells was significantly increased by mild hypoxia but decreased by severe hypoxia, mRNA level of skeletal alpha-actin, a genetic marker of cardiac hypertrophy, up-regulated after 6-24 h by mild hypoxia. A transient increase of preproET-1 mRNA and a time-dependent increase of ET-1 protein in the culture medium were also observed in cardiomyocytes exposed to mild hypoxia. BQ123 partially inhibited either hypoxia-induced [3H]leucine incorporation or skeletal alpha-actin mRNA in a dose-dependent manner. These data suggest that mild hypoxia induces hypertrophy of cardiomyocytes and that activation of endogenous ET-1 may, at least in part, mediate this hypertrophic responses as an autocrine/ paracrine factor.

Hepatocellular carcinoma associated with anabolic steroid therapy: report of a case and review of the Japanese literature

We report herein the case of a 35-year-old woman with aplastic anemia who developed hepatocellular carcinoma after long-term therapy with oxymetholone. She was treated with 60 mg/day of oxymetholone for 3 years (total dose 64.8 g). Alpha-fetoprotein, hepatitis B surface antigen, and hepatitis C antibody were all negative, but serum titers of carcinoembryonic antigen and carbohydrate antigen were elevated. Lateral segmentectomy of the liver was performed. The histopathological findings were compatible with those of multiple hepatocellular carcinoma without liver cirrhosis. Three years since the operation, the patient is doing well and no signs of tumor recurrence have been detected. According to our review of Japanese cases of hepatocellular carcinoma associated with anabolic steroid therapy, in all instances the tumors developed after long-term administration of anabolic steroids for hematologic diseases. In patients under long-term anabolic steroid therapy, routine screening of the liver by ultrasonography and computed tomography should be performed to detect liver tumors in the early stages.

Tumour necrosis factor is expressed in cardiac tissues of patients with heart failure

Tumour necrosis factor (TNF), a cytokine produced mainly by macrophages, has also been found in vascular smooth muscle cells. Elevated serum levels of TNF have been reported in various cardiac diseases, especially congestive heart failure (CHF). Although the myocardium produces several cytokines, the expression of TNF in human cardiac tissue has not yet been demonstrated. We examined TNF expression in right atrial (RA) specimens obtained from 15 patients during cardiac surgery with immunohistochemistry using an anti-human TNF monoclonal antibody, enzyme-linked immunosorbent assay (ELISA) and reverse transcriptase polymerase chain reaction (RT-PCR). TNF immunoreactivity was found only in cardiac myocytes and some vascular smooth muscle cells of small vessels of specimens from patients with severe CHF (3/5), and not in those from patients without severe CHF (0/10). ELISA of four RA specimens revealed that RA tissues from two patients with severe CHF contained more TNF than did those from two patients without severe CHF (3.1 and 4.7 pg/mg vs. 0.1 and 0.3 pg/mg). RT-PCR revealed TNF mRNA in all seven cases we examined. It was concluded that TNF mRNA is expressed by atrial tissue. The production of immunoreactive TNF-like peptides by myocytes and vascular smooth muscle cells is augmented in patients with severe CHF.

Inhibition of cell fusion by neutralizing monoclonal antibodies to F1 protein of turkey rhinotracheitis virus

Two monoclonal antibodies (mAbs) with neutralizing activities directed to the fusion (F) 1 glycoprotein of the 8597/CV94 strain of turkey rhinotracheitis (TRT) virus inhibited cell fusion by TRT virus in vitro. In contrast, F1-specific mAbs with no neutralizing activity did not inhibit the cell fusion participating in syncytium formation. These findings indicate that the neutralization epitope is the same as or overlaps the fusion active site.

Single oral dose of cisapride accelerates gastric antral emptying in healthy humans: an ultrasonographic study

An ultrasonographic study of ten healthy volunteers was carried out to evaluate the effect of cisapride on gastric antral emptying. More than 1 week after the measurement of the baseline emptying rate, cisapride was given at a single oral dose of 5 mg 30 minutes before intake of a balanced liquid test meal (5 ml/kg body weight). To determine the time to half emptying (T1/2), an exponential curve was extrapolated for the elimination phase of the gastroantral sagittal cross-sectional area plotted against time. The T1/2 was reduced by 18.5% after cisapride, from 62.6 +/- 4.3 to 51.0 +/- 4.4 min (P = 0.0284). We conclude that a single oral dose of 5 mg of cisapride significantly accelerates the gastric antral emptying rate in healthy humans.

Involvement of the endogenous opioid system in the drinking behavior of schizophrenic patients displaying self-induced water intoxication: a double-blind controlled study with naloxone

Previously we found significant suppression of polydipsia in a schizophrenic patient with PIP syndrome (psychosis, intermittent hyponatremia, and polydipsia). Suppression was obtained with a small dose of naloxone injected once every 2 weeks in long-term repeated studies. We attempted to confirm the effect of naloxone on PIP syndrome by using a double-blind controlled study. The body weights of eight schizophrenic inpatients with PIP syndrome were checked five times daily, and the maximum weight gain during 1 day was chosen as an index of their polydipsia. Naloxone (0.6 mg in three divided doses) or placebo (saline) injection was given once every 2 weeks three times. Assignment to either the naloxone or placebo series was done randomly in a double-blind, crossover design. Naloxone decreased the maximum weight gain per day significantly in five cases. However, naloxone also increased weight gain significantly in three cases. There was no correlation of the weight-increasing effect of naloxone with the duration and intensity of excessive drinking. Our findings showed that the endogenous opioid system might be related to compulsive drinking behavior in the PIP syndrome and that opioid antagonists such as naloxone or naltrexone could be useful in the therapy of PIP syndrome.

Taurocholate induces directional excretion of bilirubin into bile in perfused rat liver

The role of taurocholate, one of the major conjugated bile acids present in portal blood, in excretion of bilirubin from liver parenchyma to biliary and vascular compartments was studied in isolated perfused rat liver. Contents of bilirubin and carbon monoxide (CO) in the bile or venous effluents were determined by enzyme-linked immunosorbent microassay with the use of antibilirubin monoclonal antibody 24G7 and myoglobin-assisted spectrophotometry, respectively. In the presence of taurocholate, bilirubin excreted into the biliary compartment constituted greater than 90% of the total bilirubin excreted from the liver (0.26 nmol.min-1.g liver-1), corresponding to 60% of the outflow of CO into the venous effluents. In its absence, however, the total amount of bilirubin excreted into extrahepatic compartments was reduced to 27% of CO flux, and more than 90% of the excreted bilirubin was in the venous effluent. Thus a choleretic bile acid such as taurocholate is necessary for directional transport of bilirubin into bile in the perfused liver preparation.

Sclerosis of lytic metastatic bone lesions during treatment with pamidronate in a patient with adenocarcinoma of unknown primary site

Pamidronate disodium is a second-generation biphosphonate, a group of compounds that are being used increasingly to inhibit bone resorption in disorders that are characterized by excessive bone loss such, as hypercalcemia of malignancy, osteoporosis, and Paget's disease. The precise mechanisms whereby bisphosphonates inhibit bone resorption are still not completely understood. Pamidronate has previously been reported to induce sclerosis of lytic bone metastases in patients with breast cancer. We have had a similar experience in a patient with multiple bone metastases due to adenocarcinoma of unknown primary site who developed massive consolidation of lytic bone lesions after therapeutic infusions of pamidronate, leading to a satisfactory quality of life.

Effect of growth conditions on antimicrobial activity of DU-6859a and its bactericidal activity determined by the killing curve method

The effect of growth conditions on the antibacterial activity of DU-6859a against Staphylococcus auerus, Escherichia coli, and Pseudomonas aeruginosa was compared with those of levofloxacin, sparfloxacin, and ciprofloxacin. This activity was not affected by different media, inoculum size or the addition of human serum, but was decreased under acidic conditions, in human urine, and in the presence of magnesium and ferrous ion, as were the other quinolones tested. Time-kill curve studies demonstrated the bactericidal action of DU-6859a against S. aureus, Streptococcus pneumoniae, E. coli, and P. aeruginosa. Morphological alteration of these bacteria after exposure to DU-6859a also demonstrated its bactericidal activity. The frequency of spontaneous resistance to DU-6859a was less than or equal to those of the reference drugs.

Induction of brain prolactin receptor long-form mRNA expression and maternal behavior in pup-contacted male rats: promotion by prolactin administration and suppression by female contact

Prolactin (PRL) is considered to induce maternal behavior toward foster young in female rats. In the present study, we studied the relationship between pup contact-induced maternal behavior and serum PRL concentrations and brain PRL receptor (PRL-R) mRNA expression in male rats. Both intact and castrated male rats exposed to foster pups gradually developed caretaking behavior such as crouching and licking, but their exhibitions of other maternal behavior components, retrieval/grouping and nest building, were incomplete. However, in the male rats displaying crouching and licking, the concomitant increases in serum PRL concentration and brain mRNA expression for long-form PRL-R were observed. The expression of short-form PRL-R mRNA in the brain was not stimulated by pup contact. Administration of PRL remarkably promoted the onset of those maternal responses in male rats. On the other hand, when an intact male rat was housed in a cage where a lactating female rat and her pups were living, his scores in maternal behavior tests toward pups were lowered. And, concomitantly, increases in serum PRL concentration and brain expression of long-form PRL-R mRNA were reduced. In castrated male rats, however, the ratings of maternal behavior toward foster young, serum PRL concentration increase, or brain long-form PRL-R mRNA expression were not reduced at all by cohabitation with a female and her pups. These findings indicated that maternal behavior was triggered and maintained in pup-contacted male rats through elevated serum PRL levels and induced brain long-form PRL-R.

Accumulation of somatic nucleotide substitutions in mitochondrial DNA associated with the 3243 A-to-G tRNA(leu)(UUR) mutation in encephalomyopathy and cardiomyopathy

To understand the pathogenesis of mitochondrial encephalomyopathy and cardiomyopathy, we analyzed the sequence heterogeneity of the skeletal muscle mitochondrial DNA from a patient with Mitochondrial Encephalomyopathy, Lactic Acidosis, and Stroke-like episodes (MELAS). A mtDNA segment of 347 bp amplified from the total DNA was cloned into a vector. Analysis of 60 independent clones (20,800 bp in total) revealed the 3243 A-->G transition in all the sequenced clones and additional nucleotide substitutions at 5 sites in 10 clones. The frequency of mutant clones (10/60) in the MELAS patient was significantly higher [chi2 = 10.909, P < 0.05] than that in an age-matched skeletal muscle control (0/60) as well as in a normal placenta (2/60). These results support our hypothesis that secondary somatic mtDNA mutations can be initiated by the 3243 A-->G mutation and that the accumulation of somatic mutation in individuals with deleterious inherited mitochondrial genotype can contribute to the progressive mitochondrial dysfunction in MELAS.

Phosphorylation-independent stimulation of DNA topoisomerase II alpha activity

It has been suggested that casein kinase II phosphorylates DNA topoisomerase II alpha (topo II alpha) in mouse FM3A cells, by comparison of phosphopeptide maps of topo II alpha labeled in intact cells and of topo II alpha phosphorylated by various kinases in vitro. The phosphorylation of purified topo II alpha by casein kinase II, which attached a maximum of two phosphate groups per topo II alpha molecule, had no effect on the activity of topo II alpha. Dephosphorylation of purified topo II alpha by potato acid phosphatase, which almost completely dephosphorylated the topo II alpha, did not reduce the activity of topo II alpha. The incubation itself, regardless of phosphorylation or dephosphorylation status, stimulated the enzyme activity in both reactions. Topo II alpha activity was stimulated by incubation in a medium containing low concentrations of glycerol but not in that containing high concentrations of glycerol, such as the 50% in which purified topo II alpha is stored. The stimulation of topo II alpha activity by incubation was dependent on the concentration of topo II alpha, requiring a relatively high concentration of topo II alpha.

Mercury content in the gallstones and bile of Thai people (Chiang Mai and Bangkok) and Japanese

Mercury contents in the gallstones and bile of patients living in Thailand (Chiang Mai and Bangkok) and Japan were studied by neutron activation analysis. The correlation between contents in the gallstones and bile, and the amount of mercury in the diet and environment was investigated by comparing the contents in patients living in three different areas. The content in the bile of the Japanese patients was significantly greater than that of the Thai patients. The distribution of mercury contents in the pigment and rare stones of patients living in Bangkok indicated a bipolarity. However, the distribution of the contents in cholesterol, pigment, and rare stones of Japanese patients did not indicate a bipolarity. Bipolarity would indicate the amount of mercury in dietary foods, and the pollution level of mercury. The mercury contents in the gallstones and bile would reflect the amount of mercury in the diet and environment.

Epidural test dose: isoproterenol is a reliable marker for intravascular injection in anesthetized adults

Epidural test doses containing more than 15 micrograms epinephrine are reliable for the detection of intravascular injection based on the conventional systolic blood pressure (SBP) criterion (positive if > or = 15 mm Hg increase) but not on the heart rate (HR) criterion (positive if > or = 20 bpm increase) in adult patients anesthetized with isoflurane. The present study was designed to test whether isoproterenol could be used as a reliable marker. Thirty adult patients were randomly assigned to one of two groups, each of which was anesthetized with 1% end-tidal isoflurane and nitrous oxide after endotracheal intubation. Isoproterenol group (n = 15) was given 3 mL of 1.5% lidocaine with 3 micrograms isoproterenol intravenously (i.v.) to simulate an i.v. administered test dose. The saline group (n = 15) was identical to the isoproterenol group but received 3 mL of normal saline. HR and arterial blood pressure were measured at 20-s intervals for 4 min after i.v. injection. Mean HR in the isoproterenol group was significantly higher than in the saline group from 40 to 240 s after i.v. test dose with a mean maximum HR increase of 32 +/- 7 bpm (mean +/- SD) occurring at 68 +/- 19 s. All 15 patients in the isoproterenol group developed HR increases > or = 20 bpm (sensitivity 100%). Since HR was essentially unchanged in the saline group, specificity and positive and negative predictive values were all 100%. On the other hand, 12 of 15 patients in the isoproterenol group and none in the saline group exhibited SBP increases > or = 15 mm Hg, resulting in 80% sensitivity and 83% negative predictive value. In the isoproterenol group, however, transient systolic hypotension ( < 80% of the preinjection value) occurred in five patients without untoward clinical sequelae. These results indicate that, based on the peak HR response, the epidural test dose containing 3 micrograms isoproterenol is a reliable marker for intravascular injection in adult patients during isoflurane anesthesia.

Induction and involvement of endogenous IGF-I in pancreas regeneration after partial pancreatectomy in the dog

To elucidate whether and how IGF-I is involved in the regeneration of the pancreas after partial pancreatectomy, IGF-I mRNA expression, IGF-I protein synthesis, ornithine decarboxylase (ODC) activity and DNA replication in the remnant pancreas were determined in the dog. After pancreatectomy, IGF-I mRNA expression was remarkably enhanced in the remnant pancreas, showing the maximal value at post-operative day (POD) 1. Subsequently, IGF-I synthesis in the tissue was significantly stimulated at POD 2, and its maximal concentration was observed at POD 3. Following IGF-I synthesis, ODC activity was induced and its maximal activity was also obtained at POD 3. Finally, DNA replication was induced in the remnant pancreas, and its maximal level was observed at POD 5. These responses in the remnant pancreatic tissue to partial pancreatectomy were greatly enhanced as the resection rate was increased up to 95%. Positive correlations were observed between IGF-I concentrations in the remnant pancreas and the activities of ODC and DNA synthesis in the tissue after 95% pancreatectomy. These results suggest that the gene expression of IGF-I is rapidly induced in the remnant pancreas after partial pancreatectomy, and subsequently synthesized endogenous IGF-I peptides may stimulate ODC and other cell growth-related activities in the tissue in paracrine and/or autocrine manners eventually to induce DNA replication and tissue regeneration.

Effect of MCI-186 on postischemic reperfusion injury in isolated rat heart

MCI-186 (3-methyl-1-phenyl-2-pyrazolin-5-one) is a newly developed antioxidant which has been shown to reduce brain edema in cerebral ischemia through inhibition of the lipoxygenase pathway of arachidonic acid. However, its effect on myocardial reperfusion injury after prolonged ischemia has not yet been demonstrated. We compared the mode of the effect of MIC-186 and recombinant human CuZn superoxide dismutase (rh-SOD) in isolated perfused rat hearts subjected to 60-min ischemia followed by 60-min reperfusion. Left ventricular developed pressure (LVDP), necrotic area and the release of creatine phosphokinase (CPK) and endogenous CuZn superoxide dismutase (endoge-SOD) were measured to evaluate myocardial damage. The decrease in left coronary flow (CBF) was measured as an index of the damage of left coronary circulation. MCI-186 (14.5 mg/L) was perfused for 10 min in the MCI group and rh-SOD (70 mg/L) was perfused during the reperfusion period in the SOD group starting 5 min prior to reperfusion. The release patterns of CPK and endoge-SOD were analyzed to elucidate the difference in the mode of protection of MCI-186 and rh-SOD. The LVDP remained higher in both MCI and SOD groups than that of control (76 +/- 1, 77 +/- 2 and 69 +/- 1% of preischemic value, respectively). The necrotic area was significantly attenuated in both MCI and SOD groups compared with that in the control group (16 +/- 1, 14 +/- 1 and 32 +/- 1%, respectively, p < 0.05). Total CPK release was lower in both MCI and SOD groups than in the control (78 +/- 7, 100 +/- 2 and 116 +/- 4 x 10(3) units/g myocardium respectively). The decrease in CPK release was more marked in the MCI group than that in the SOD group (p < 0.05). The reduction in CBF was significantly attenuated by the treatment with rh-SOD or MCI-186, but the effect was much higher in the SOD group than in the MCI group (69 +/- 5, 58 +/- 2, and 48 +/- 2% in SOD, MCI and control groups, respectively). The release pattern of endoge-SOD was identical to that of CPK and thus this did not distinguish the mode of effect of MCI-186 from that of rh-SOD. These results indicate that MCI-186 reduces reperfusion injury in isolated perfused hearts with prolonged ischemia and the effect is more closely related to the reduction of myocyte damage than the preservation of the coronary circulation.