Characterization of microsomal cytochrome P450 enzymes involved in the oxidation of xenobiotic chemicals in human fetal liver and adult lungs

Levels and catalytic activities of cytochrome P450 (P450) enzymes involved in the oxidation of drugs and carcinogens were determined in human adult lungs and fetal livers and compared with those in microsomes from adult livers. P450s immunoreactive with anti-human P4501A1 and anti-human P4503A antibodies were detected in fetal liver microsomes by immunoblotting analysis, and P450s related P4501A1, 2A6, 2C9, 2E1, and 3A4 were determined in adult lung microsomes; all of these P450 enzymes were detected in much higher amounts in adult liver microsomes except that P4501A2 was only the 1A subfamily of P450 found in adult livers. Drug oxidation activities with the substrates ethoxyresorufin, coumarin, 7-ethoxycoumarin, bufuralol, and testosterone were determined in these microsomes, and we found that none of the activities were higher in microsomes of adult lungs and fetal livers than in adult livers. Activation of procarcinogens to reactive metabolites that induce umu gene expression in Salmonella typhimurium TA1535/pSK1002 or NM2009 was also examined and it was found that activities with (+)- and (-)-enantiomers of 7,8-dihydroxy-7,8-dihydrobenzo[a]pyrene were higher in fetal liver microsomes than adult lung or liver microsomes. The adult liver and lung activities for these two procarcinogens were similar on the basis of microsomal protein contents despite the fact that p450 contents are higher in liver than lung microsomes. alpha-Naphthoflavone, a known inhibitor of P4501A-related activities, did not affect these procarcinogen activation in fetal liver microsomes. Fetal liver microsomes catalyzed activation of aflatoxin B1 and sterigmatocystin, two procarcinogens known to be activated by P4503A4/7 in humans, although activation of carcinogenic arylamines that are good substrates for P4501A2 was much lower in microsomes of fetal livers and adult lungs than in adult livers. These results suggest that in human fetal livers at least two P450 enzymes, a form of P450 that is immunoreactive P4501A1 and P4503A7, are actually expressed and these enzymes are suggested as being involved in the activation of the (+)- and (-)-enantiomers of 7,8-dihydroxy-7,8-dihydrobenzo[a]pyrene and the carcinogenic mycotoxins, respectively. The exact nature of the former enzyme in fetal livers is unknown. In adult human lungs, several P450 enzymes are expressed, although the precise roles of these enzymes in the oxidation of xenobiotics were not determined due to the low level of expression of these P450s.

[The effect of alpha-glucosidase inhibitor on burning epigastralgia in dumping syndrome: a case report]

Dumping syndrome results from a rapid passage of carbohydrate in the small intestine after gastric surgery. A 50-year-old man developed the syndrome after surgery for peptic ulcer. He often complained of burning epigastralgia after meals. Various methods of treatment had only a limited effect. Acarbose, alpha-glucosidase inhibitor, suppresses the breakdown of carbohydrates in the small intestine and consequently reduced osmolarity. The patient had a dramatic improvement in the dumping syndrome including epigastralgia, diarrhea and perspiration with an administration of acarbose 50 mg. There was no intractable side effect. Preprandial administration of acarbose is a reasonable treatment in the case of dumping syndrome.

7-Ethoxycoumarin O-deethylation catalyzed by cytochromes P450 1A2 and 2E1 in human liver microsomes

7-Ethoxycoumarin O-deethylation has been used widely as a marker activity for assessing substrate specificities of cytochromes P450 (P450) in liver microsomes of mammals, and extensive studies have shown that in rats and mice the major catalysts are P450 1A1, 1A2, and 2B enzymes. In contrast to findings in experimental animal models, P450 2E1 has been reported to be a principal enzyme involved in 7-ethoxy-coumarin O-deethylation in human livers. In this study, we further examined the roles of individual forms of human P450 involved in 7-ethoxycoumarin O-deethylation using microsomes from different human liver samples and from human lymphoblastoid cells expressing human P450 enzymes and purified P450 enzymes isolated from the membrane of Escherichia coli expressing modified P450 proteins. Kinetic analysis showed that there were at least two different enzymes involved in 7-ethoxycoumarin O-deethylation in different human samples. Samples that contained high amounts of P450 2E1 in liver microsomes showed biphasic curves for O-deethylation with relatively high turnover numbers, whereas P450 1A2-rich samples tended to have low Km values with low Vmax values. Anti-human P450 2E1 antibodies inhibited markedly (P < 0.05) the 7-ethoxycoumarin O-deethylation activities catalyzed by human liver microsomes particularly when examined at a high substrate concentration (200 microM). However, we also found that anti-P450 1A2 antibodies suppressed O-deethylation activities only at a low substrate concentration (10 microM). Recombinant human P450 1A2 was found to have a low Km value for 7-ethoxycoumarin O-deethylation, whereas P450 2E1 showed a high Km value. Of the P450 enzymes examined, P450 1A1 gave the highest O-deethylation activities with a low Km value, although this enzyme is reported to be expressed extrahepatically in humans. Other human P450 enzymes, including P450 2A6, 2C10, 2D6, 3A4, and 3A5, did not show significant O-deethylation activities except that P450 2B6, a minor P450 component in human livers, was found to have a Vmax value similar to that of P450 1A2 and a Km value similar to that of P450 2E1. These results suggest that P450 1A2 is a low Km enzyme for 7-ethoxycoumarin O-deethylation in human liver microsome, although it has a low Vmax value than P450 2E1.

[A study on radiosensitivity cell line SSM-1 derived human oral malignant melanoma]

In order to study the efficiency of radiation therapy for human oral malignant melanoma, radiosensitivity for SSM-1 cell line derived from oral malignant melanoma was investigated by colony formation rate, survival curve, light microscopic observation, ultrastructual observation and immunocytochemical study with HMB-45. Survival curve of the SSM-1 cells was higher than that of cutaneous melanoma cell lines for radiosensitivity. Uniform masses of SSM-1 cells were found even with high dose irradiation. Giant cells and multiple nuclei cells were found after high dose irradiation. By ultrastructural observation, various nucleoi, chromatins and nucleus structures were found after low dose irradiation. Immunocytochemically, hot nodules of SSM-1 cells were found to have HMB-45 antibody, and the hot nodules increased after irradiation, suggesting increased number of melanosomes. By ultrastructural observation, the number of melanosomes was found to have increased after low dose irradiation. Radiosensitivity of SSM-1 cell line derived from oral malignant melanoma was higher than that of cutaneous melanoma cell lines, and the results of this study might support that radiotherapy is helpful for oral malignant melanoma.

Germinoma arising in the basal ganglia in early stage: CT and MR findings

We report a patient with a germinoma originating in the left basal ganglia. Unenhanced computed tomography (CT) revealed a relatively well-defined high-density lesion, which was slightly enhanced with contrast medium. No tumor stain was noted on angiography. The mass showed hypointensity on T1-weighted magnetic resonance imaging (MRI), and heterogeneous hyperintensity on T2-weighted imaging. The lesion was homogeneously enhanced after the administration of Gd-DTPA. To our knowledge, the MR findings of basal ganglia germinoma have been retrospectively reviewed in just four reported cases, only two of which were examined with Gd-DTPA enhancement. The two cases revealed relatively large masses with cysts and peritumoral edema, and were slightly enhanced after the intravenous injection of Gd-DTPA. Our case was thought to be in the early stage, and its CT and MR findings were slightly different from those of previously reported cases.

[Cognitive dysfunction following anterior communicating artery aneurysm rupture. Comparison with alcoholic Korsakoff syndrome on neuropsychological performance]

The present study aims to compare neuropsychological performance of patients following anterior communicating artery aneurysm rupture (ACoA) with that of patients with alcoholic Korsakoff syndrome (AKS). Fifteen ACoA patients and ten age-and education-matched AKS patients were included in the study. All the patients were tested at least one year post onset of their illness at a stable condition. The WAIS and forward digit span scores of AKS were also matched to ACoA, and simple attention and general intelligence were well preserved both in ACoA and AKS. Frontal function as measured by the Wisconsin card sorting test (Keio version) (KWCST) was equivalently impaired in the two groups. Anterograde memory as measured by Wechsler memory scale subtests, serial seven word learning test, Rey auditory verbal learning test, and logical memorizing test (Luria's paired word-picture association), was more severely impaired in AKS than ACoA in contrast to the comparable attention, intelligence, and frontal function: (1) memory tasks with low correlations to KWCST (serial word learning tasks and paired verbal associates), reflecting primary simple serial memorizing, and (2) memory tasks with high correlations to KWCST (logical memory and logical memorizing), reflecting higher and complicated strategic mnemonic activities. However, the correlations between these anterograde memory subtests and KWCST were substantially equivalent in ACoA and AKS. This suggests that the differences in anterograde amnesia demonstrated in ACoA and AKS may be of quantitative, not of qualitative property. The extent of deficits in semantic encoding as measured by Wickens' release from proactive interference paradigm (PI release) was also milder in ACoA than AKS. Both AKS and ACoA failed to show PI release in contrast to normal PI release demonstrated in age-matched ten healthy subjects. PI release in ACoA, however, was in between AKS and healthy subjects. The results were interpreted in the light of a recently postulated hypothesis that a combination of frontal lobe damage and memory impairment is crucial for causing a deficit in semantic encoding. The extent of damage in the memory circuit in ACoA may be variable, which may result in milder degree of anterograde amnesia and semantic encoding than AKS in the present study.

[A survey of perioperative bronchospasm in 105 patients with reactive airway disease]

We investigated the relationship between the intra- and postoperative incidence of bronchospasm and the predisposing preoperative factors in 105 patients with reactive airway disease. (1) The incidence of bronchospasm in intra- and postoperative period was not associated with age, sex, duration of bronchial asthma, severity of disease, duration of the anesthesia and operation, or with FEV1.0%. (2) The incidence of intraoperative bronchospasm was high with general anesthesia using endotracheal intubation (8.9%), but low with general anesthesia using mask and regional anesthesia (0% and 2.2%, respectively). (3) The incidence of postoperative bronchospasm was about 20% with both general and regional anesthesia. However, the incidence of postoperative bronchospasm was higher in thoracic and abdominal surgeries than in other surgeries (39.5%:10.4%). (4) The incidences of intra- and postoperative bronchospasm increased in proportion to the proximity of the latest asthmatic attack to the operative date. (5) Prophylactic preoperative inhalation of bronchodilators was effective in the prevention of intraoperative bronchospasm, but some patients developed postoperative wheezing within a few days after the cessation of postoperative inhalation.

[Electronmicroscopic study on tongue squamous cell carcinoma--radiotherapy cases]

We examined the ultrastructures of the tongue squamous cell carcinomas which received radiotherapy and compared the metastatic cases with the non-metastatic cases. The results were as follows: 1. The non-metastatic cases were clinically T1N0 or T2N0 and histologically Grade I or II of the WHO classification. Electronmicroscopic observation of these cases revealed that numerous microvilli and a small number of desmosomes were found and the cell attachment seemed to be weak. These findings were different from those of the non-metastatic cases which received surgery. 2. In the metastatic cases of which the primary lesions were controlled, microvilli were not developed and a number of desmosomes were shown as compared with those in the non-metastatic cases. However, cell atypia and dispersion of the nuclear chromatin were clearly recognized.

Synthesis and antiallergic activity of novel azaazulene derivatives

Various azaazulene derivatives were synthesized and their antiallergic activity was examined. The structure-activity relationship among various derivatives modified by introducing substituents at the 1-,2-, or 3-position of the azaazulene ring was investigated. The inhibitory activities on allergic histamine release of the compounds bearing a 5-tetrazolyl group at the 3-position were more potent than those of the corresponding compounds with other groups (CN, COOH, and CHO). The compounds substituted with amino, azide and carboxymethylamino groups at the 2-position showed strong inhibitory activity. The compounds with various phenylalkyl groups at the 1-position showed a greater activity than those with other substituents. Among the compounds with substituents at the 1-,2-, or 3-position of the azaazulene ring, 1-benzyl-7-isopropyl-3-(5-tetrazolyl)-1-azaazulen-2-one (18f) and 1-(4-fluorobenzyl)-7-isopropyl-3-(5-tetrazolyl)-1-azaazulen- 2-one (19c) had the most potent inhibitory activities on histamine release from mast cells and on passive cutaneous anaphylaxis (PCA) in rats after oral administration (ED50 = 0.56 and 0.58 mg/kg, respectively).

Conformation of (2-->1)-beta-D-fructan in aqueous solution

The conformation and dilute solution properties of (2-->1)-beta-D-fructan in aqueous solution were studied by gel permeation chromatography, low-angle laser light-scattering photometry, viscometry, small-angle X-ray scattering and electron microscopy. Fractions covering a broad range of weight-average molecular weights (Mw) from 1.49 x 10(4) to 5.29 x 10(6) were obtained from a native sample by ultrasonic degradation and fractional precipitation. For Mw < 4 x 10(4), the intrinsic viscosity [eta] varies with Mw0.71, indicating that the fructan chain behaves as a random coil expanded by an excluded-volume effect in this molecular weight region. For Mw > 10(5), [eta] exhibits an unusually weak dependence on Mw and finally becomes almost independent of molecular weight. This behaviour is interpreted in terms of a globular conformation of the high-molecular-weight fructan molecules. Small-angle X-ray-scattering measurements and electron microscopic observations support this interpretation of the values of [eta] observed.

Catalytic roles of rat and human cytochrome P450 2A enzymes in testosterone 7 alpha- and coumarin 7-hydroxylations

Differences in the catalytic roles of rat and human cytochrome P450 2A enzymes in testosterone 7 alpha- and coumarin 7-hydroxylase activities were examined. Liver microsomes from 18 human samples catalyzed coumarin 7-hydroxylation at a mean rate of about 60 pmol/min/nmol P450, but did not show any measurable activity for testosterone 7 alpha-hydroxylation. In rats, both activities were found to be developmentally regulated; 3-week-old rats had the highest activities for these two reactions. Anti-P450 2A1 antibodies and methoxsalen, a potent inhibitor of P450 2A-dependent monooxygenase activities in several animal species, inhibited almost completely both testosterone 7 alpha- and coumarin 7-hydroxylations catalyzed by liver microsomes prepared from 3-week-old male rats. Interestingly, although Km values for coumarin 7-hydroxylation activities in liver microsomes from 3-week-old rats were not different from those of adult humans, the Vmax value in rats was only 1/30 of that obtained in 18 human samples. Thus, the present results support the view that marked differences exist in the catalytic roles of rat and human P450 2A enzymes, which, in turn, may sometimes cause species-related differences in susceptibilities toward drug actions and toxicities.

Bufuralol hydroxylation by cytochrome P450 2D6 and 1A2 enzymes in human liver microsomes

Bufuralol 1'-hydroxylation is a prototypical reaction catalyzed by cytochrome P450 (P450) 2D6, an enzyme known to show debrisoquine/sparteine-type genetic polymorphism in humans. In the present study we further examined the roles of several human P450 enzymes, as well as P450 2D6, in the hydroxylation of (+/-)-bufuralol, using liver microsomes from several human samples and human P450 enzymes expressed in human lymphoblastoid cell lines or Escherichia coli. Kinetic analysis of bufuralol 1'-hydroxylation by liver microsomes showed that there were different Km and Vmax values in seven human samples examined; low Km values (approximately 0.05 mM) were observed in four samples (including sample HL-18), high Km values (approximately 0.25 mM) in two samples (including sample HL-67), and an intermediate Km value (approximately 0.1 mM) in one sample. Quinidine and anti-rat P450 2D1 antibody almost completely inhibited bufuralol 1'-hydroxylation in human sample HL-18 at a substrate concentration of 0.4 mM, whereas these effects were not so drastic when liver microsomes from human sample HL-67 were used. In contrast, a very low concentration (< 10 microM) of alpha-naphthoflavone or anti-human P450 1A2 antibody significantly inhibited bufuralol 1'-hydroxylation catalyzed by human sample HL-67, but not HL-18, with 0.4 mM bufuralol. When the relative contents of P450 2D6 and P450 1A2 in 20 human samples were determined, bufuralol 1'-hydroxylation in samples containing large amounts of P450 2D6 tended to be more sensitive to quinidine, whereas the P450 1A2-rich samples were highly susceptible to alpha-naphthoflavone. However, at low substrate concentrations bufuralol 1'-hydroxylation was shown to be catalyzed principally by P450 2D6, based on the inhibitory effects of anti-rat P450 2D1 antibody and quinidine, in both human samples HL-18 and HL-67. At least five other, minor, bufuralol products were formed by human liver microsomes, in addition to 1'-hydroxybufuralol. Two of them were identified as 4- and 6-hydroxybufuralol by 1H NMR spectroscopy and mass spectrometry. The formation of the 4- and 6-hydroxylated products was suggested to be catalyzed by P450 1A2, based on the results of correlation with P450 1A2 contents in 60 human samples and inhibition by anti-P450 1A2 and alpha-naphthoflavone. Purified recombinant P450 1A2 (expressed in E. coli) produced 1'-, 4-, and 6-hydroxybufuralol in a reconstituted system, although P450 2D6 (expressed in human lymphoblast cell lines) was found to catalyze only bufuralol 1'-hydroxylation.(ABSTRACT TRUNCATED AT 400 WORDS)

Interindividual variations in human liver cytochrome P-450 enzymes involved in the oxidation of drugs, carcinogens and toxic chemicals: studies with liver microsomes of 30 Japanese and 30 Caucasians

Interindividual variations in the level and activity of cytochrome P-450 enzymes were investigated in the liver microsomes of 30 Japanese and 30 Caucasian patients. The P-450 enzymes used in this study included P-450 1A2, 2A6, 2B6, 2C, 2D6, 2E1 and 3A, and the monooxygenase activities determined were 13 typical P-450 substrates and 9 procarcinogens. Although the total P-450 content was higher in Caucasian (mean, 0.43 nmol/mg of protein) than in Japanese populations (mean, 0.26 nmol/mg of protein), the relative levels (percent of total P-450) of individual forms of P-450 determined immunochemically were not very different except that P-450 2A6 and 2B6 levels were higher in the Caucasians. About 70% of liver P-450 could be accounted for by P-450 1A2, 2A6, 2B6, 2C, 2D6, 2E1 and 3A proteins, and P-450 3A (about 30% of total P-450) and 2C (about 20%) enzymes were found to be the major forms. Considerable levels of P-450 1A2 (about 13%) and 2E1 (about 7%) could be determined, whereas the P-450 2A6 (about 4%), 2D6 (about 2%) and 2B6 (< 1%) were the minor P-450 forms. Differences in some of the P-450 1A2-, 2A6-, 2D6-, 2E1- and 3A4-dependent activities were observed in Japanese and Caucasian populations. No clear sex-related differences in individual P-450 contents and drug- and carcinogen-metabolizing activities were detected in 60 human samples, except that P-450 1A2-dependent activities were found to be higher in mean than in women in the Caucasian population only. A single neonate sample tended to be lower in P-450 1A2-, 2A6- and 2E1-dependent activities. In contrast to rat counterparts, we could not detect apparent developmental changes in P-450 content and activity in humans between 12 and 73 years old. Thus, the results presented in this study provide useful information for the study of drug biotransformation in humans and for the basis of drug toxicities, carcinogenesis and teratogenesis.

Disc degeneration affects the multidirectional flexibility of the lumbar spine

STUDY DESIGN

An in vitro biomechanical investigation using human lumbar cadaveric spine specimens was undertaken to determine any relationship between intervertebral disc degeneration and nonlinear multidirectional spinal flexibility.

SUMMARY OF BACKGROUND DATA

Previous clinical and biomechanical studies have not established conclusively such a relationship.

METHODS

Forty-seven discs from 12 whole lumbar spine specimens were studied under the application of flexion-extension, axial rotation, and lateral bending pure moments. Three flexibility parameters were defined (neutral zone (NZ), range of motion (ROM), and neutral zone ratio (NZR = NZ/ROM)) and correlated with the macroscopic and radiographic degeneration.

RESULTS AND CONCLUSIONS

In flexion-extension, the ROM decreased and NZR increased with degeneration. In axial rotation, NZ and NZR increased with degeneration. In lateral bending, the ROM significantly decreased and the NZR increased with degeneration. In all three loading directions, the NZR increased, indicating greater joint laxity with degeneration.

Differential roles of cytochromes P450 2D1, 2C11, and 1A1/2 in the hydroxylation of bufuralol by rat liver microsomes

Bufuralol hydroxylation activities of liver microsomal cytochrome P450 (P450) enzymes were studied in the rat; the reaction has been used widely in determining levels of liver microsomal P450 2D6, which shows debrisoquine-type genetic polymorphism in humans. Liver microsomes catalyzed the conversion of bufuralol to 1'-hydroxybufuralol and a structurally unidentified metabolite (termed here as M-1) in the presence of an NADPH-generating system and molecular oxygen. Bufuralol 1'-hydroxylation activities catalyzed by the liver microsomes were not increased in rats treated with several P450 inducers, whereas beta-naphthoflavone treatment (and to a lesser extent that of isosafrole) caused a significant induction of M-1 formation. The major role of P450 1A1/2 in M-1 formation was confirmed by catalytic inhibition with anti-P450 antibodies and alpha-naphthoflavone in liver microsomes of beta-naphthoflavone-treated rats, and by reconstitution experiments containing P450 1A1 and 1A2. Among nine forms of purified rat P450 enzymes studied in the reconstituted system, P450 2C11 displayed the highest activities for bufuralol 1'-hydroxylation, followed by P450 1A1 and P450 2D1. A female-specific form of P450 2C12 did not catalyze bufuralol 1'-hydroxylation. In liver microsomes of male rats, however, P450 2D1 was the dominant enzyme because only anti-P450 2D1 antibodies, and not anti-P450 2C11 and anti-P450 1A1, inhibited the bufuralol hydroxylation activities, and a specific P450 2D1 inhibitor, quinine, caused a dramatic decrease in the hydroxylation activities. The major contribution of P450 2D1 in the bufuralol 1'-hydroxylation activities was also supported by a kinetic analysis of the reconstituted system; P450 2D1 enzyme had a very low Km value (8.4 microM) as compared with those of P450 2C11 (Km = 83 microM) and P450 1A1 (Km = 230 microM). Thus, the present results suggested that different P450 enzymes are involved in the hydroxylation of bufuralol in rat liver microsomes, and the kinetic analysis, as well as immunoinhibition and chemical inhibition experiments, may be of great importance for determining the major roles of P450 enzymes in drug hydroxylation reactions.

Activation of trans-1,2-dihydro-1,2-dihydroxy-6-aminochrysene to genotoxic metabolites by rat and human cytochromes P450

In order to address the hypothesis that 6-aminochrysene (6-AC) is converted to genotoxic products by cytochrome P450 enzymes via two activation pathways (N-hydroxylation and epoxidation), the activation of 6-AC and trans-1,2-dihydro-1,2-dihydroxy-6-aminochrysene (6-AC-diol) to genotoxic metabolites was examined in rat and human liver microsomal cytochrome P450 enzymes using Salmonella typhimurium TA1535/pSK1002 and TA1535/pSK1002/pNM12 (NM2009) as tester strains. The latter bacteria, an O-acetyltransferase-overexpressing strain, was highly sensitive to metabolites derived from activation of 6-AC, but not those from 6-AC-diol, using liver microsomes from phenobarbital-treated rats or a reconstituted monooxygenase system containing P4502B1 or -2B2, thus suggesting the roles of P450 and acetyltransferase systems in the activation process. 6-AC-diol, on the other hand, was activated very efficiently by liver microsomes prepared from beta-naphthoflavone-treated rats or a reconstituted system containing P4501A1 or -1A2; the activation reaction is considered to proceed through diol-epoxide formation. The contribution of rat P4501A enzymes towards activation of 6-AC-diol was confirmed by the inhibitory effects on the activation process of alpha-naphthoflavone, a specific inhibitor of P4501A-related activities, and antibodies raised against purified P4501A1 and -1A2. In humans, P4501A2 was found to be the major enzyme involved in the activation of 6-AC-diol to genotoxic metabolites while the parent compound 6-AC was activated mainly by P4503A4. Experiments using recombinant P450 proteins expressed in human lymphoblastoid cell lines showed that human P4501A1 could also activate 6-AC-diol to reactive metabolites at almost the same rate measured with P4501A2. In addition, P4502B6 was found to efficiently catalyze the activation of 6-AC to genotoxic metabolites, and P4503A4 was active in the activation of 6-AC-diol as well as 6-AC. Addition of purified rat epoxide hydrolase to the incubation mixture containing purified rat P4501A1 or microsomes expressing human P4501A1 caused inhibition of activation of 6-AC-diol. These results suggest the existence of different enzymatic activation pathways for 6-AC and 6-AC-diol. The former carcinogen may be N-hydroxylated principally by P4502B enzymes in rats and P4503A4 and -2B6 in humans and activation to its ultimate metabolites may proceed through esterification of the N-hydroxy metabolites by an N-acetyltransferase. The 6-AC-diol is metabolized to its ultimate diolepoxide product by P4501A enzymes in rat and human liver microsomes. P4503A4 (humans) and P4503A2 (rats) may also contribute to some extent in the activation of 6-AC-diol, albeit at lower rates than those of P4501A enzymes.

Three-dimensional motion of the upper cervical spine in rheumatoid arthritis

Rheumatoid arthritis frequently contributes to instability of the upper cervical spine. Rotational instability of the upper cervical spine was evaluated in rheumatoid arthritis patients using biplanar x-ray photogrammetry. Three-dimensional cervical motion and the instantaneous axis of rotation of the atlas relative to the axis were evaluated in normal and rheumatoid arthritis patients during axial rotation in the horizontal plane. Anterior atlantoaxial subluxation did not increase during axial head rotation in either the atlantoaxial subluxation or the vertical subluxation groups, while the instantaneous axes of rotation were distributed posteriorly in the dens in the RA-normal group, but were widely scattered in the atlantoaxial subluxation group.

Reduction of erythrocyte (Na(+)-K+)ATPase activity in type 2 (non-insulin-dependent) diabetic patients with microalbuminuria

In order to elucidate the causal relationship between (Na(+)-K+)ATPase and diabetic nephropathy, we studied the erythrocyte (Na(+)-K+)ATPase activity in Type 2 diabetic patients, 20 with microalbuminuria and 27 without microalbuminuria and in 16 control subjects. (Na(+)-K+)ATPase activities in microalbuminuric patients (0.273 +/- 0.012 mumol Pi/mg protein/h, mean +/- SE) were significantly reduced compared with those without microalbuminuric patients (0.308 +/- 0.011 mumol Pi/mg protein/h, p < 0.05) and control subjects (0.330 +/- 0.011 mumol Pi/mg protein/h, p < 0.01). Microalbuminuric patients had higher systolic blood pressure (133 +/- 3 vs 124 +/- 3 mmHg, p < 0.05) and greater frequency of parental hypertension (50% vs 19%, p < 0.05) than those without microalbuminuria. (Na(+)-K+)ATPase activities in diabetic patients with hypertension were significantly reduced compared with those in diabetic patients without hypertension. Moreover, (Na(+)-K+)ATPase activities in diabetic patients with parental hypertension were significantly reduced compared with those in patients without parental hypertension. There was no difference in erythrocyte Na+ content between with and without microalbuminuria or hypertension or parental hypertension in diabetic patients. Erythrocyte Na+ content was significantly negatively correlated with (Na(+)-K+)ATPase activity in control subjects (r = -0.619, p < 0.05), but not in diabetic patients (r = -0.194). Plasma digitalis-like substances showed no correlation with (Na(+)-K+)ATPase activities in diabetic patients with microalbuminuria or hypertension or parental hypertension. We concluded that the reduction of erythrocyte (Na(+)-K+)ATPase activity may be related to a familial predisposition to arterial hypertension and may partly be responsible for the development of diabetic nephropathy in Type 2 diabetic patients.

Synthesis and evaluation of (piperidinomethylene)bis(phosphonic acid) derivatives as anti-osteoporosis agents

Some (piperidinomethylene)bis(phosphonic acid) derivatives were prepared and their activity to inhibit a rise in serum calcium induced by parathyroid hormone in thyroparathyroidectomised rats was evaluated. Several (4-alkylidene-, 4,4-dialkyl-, or 4-alkyl-4-halopiperidinomethylene)bis(phosphonic acid) derivatives showed considerable inhibitory activity. But compounds having aromatic and polar substituents such as azido, hydroxy, amino and amido on the piperidine ring were generally inactive. In this study, two 4-alkylidene compounds (8a and 8b) and a 4,4-cyclic dialkyl compound (61) showed potent activity when administered either intravenously or perorally.

Characterization of cytochrome P-450 2B6 in human liver microsomes

A cytochrome P-450 (P-450) enzyme of the CYP2B subfamily was partially purified from human liver microsomes and characterized with respect to immunochemical properties, N-terminal amino acid sequence, and catalytic activities toward typical P-450 substrates. P-450 enzymes were monitored in chromatographic fractions by immunoblotting analysis using antibodies raised against a monkey P-450 2B, as well as several purified human P-450 enzymes. The final P-450 2B preparation thus obtained was contaminated with P-450 3A4, but an N-terminal amino acid sequence matching the sequence predicted from the CYP2B6 cDNA was obtained. The apparent M(r) of this protein was 48 kDa, and the migration on sodium dodecyl sulfate-polyacrylamide gel electrophoresis was the same as that of the P-450 2B6 protein expressed in a human lymphoblast cell line. Immunoblotting analysis of 50 human liver samples revealed that the protein band considered to be P-450 2B6 was detected in only 12 samples, with four of these having relatively high levels. Several activities toward typical P-450 substrates were determined in a reconstituted monooxygenase system containing partially purified P-450 2B6 and compared with those obtained using a highly purified preparation of P-450 3A4 enzyme; we found that most of the activities were similar in these preparations, except that the partially purified P-450 2B6 showed high rates of activation of the mutagens 6-aminochrysene and 3-methoxy-4-aminoazobenzene to genotoxic metabolites in Salmonella typhimurium NM2009 strain.(ABSTRACT TRUNCATED AT 250 WORDS)

Roles of different forms of cytochrome P450 in the activation of the promutagen 6-aminochrysene to genotoxic metabolites in human liver microsomes

We reported previously that the potent mutagen 6-aminochrysene is catalyzed principally by rat liver microsomal P4501A and P4502B enzymes to reactive metabolites that induce umu gene expression in O-acetyltransferase-over-expressing strain Salmonella typhimurium NM2009; the proposal was made that there are different mechanisms in the formation of reactive N-hydroxylated and diolepoxide metabolites by P450 enzymes (Yamazaki, H. and Shimada, T., Biochem. Pharmacol., 44, 913-920, 1992). Here we further examined the roles of human liver P450 enzymes and the mechanism of activation of 6-aminochrysene by rat and human P450 enzymes in the Salmonella tester strains. Liver microsomes from 18 different human samples catalyzed activation of 6-aminochrysene more efficiently in S. typhimurium NM2009 than in the original strain of S. typhimurium TA1535/pSK1002. The rates of 6-aminochrysene activation in 18 human liver samples showed good correlation to the contents of P4502B6 as well as contents of P4503A4 and the respective mono-oxygenase activities catalyzed by P4503A4. Among purified P450 enzymes examined, P4501A2 as well as P4503A4 were highly active in transforming 6-amino-chrysene to reactive metabolites, suggesting the involvement of different human P450 enzymes in the reaction. Four human samples that contained relatively high levels of particular P450 enzymes in their microsomes were selected and used for further characterization. Liver microsomes from human samples HL-13 and HL-4 that contained the highest levels of P4502B6 and P4503A4 respectively, were sensitive to the respective antibodies raised against monkey P4502B and human P4503A4; the activity in sample HL-16 having the highest level of P4501A2 was inhibited by anti-P4501A2 IgG. alpha-Naphthoflavone enhanced the activation of 6-aminochrysene very significantly in human liver microsomes enriched in P4503A4 and P4502B6 enzymes. Pentachlorophenol, an inhibitor of acetyltransferase activity, suppressed the activation of 6-aminochrysene in liver microsomes from phenobarbital-treated rats and from human samples HL-4, HL-13 and HL-18 but not HL-16. In contrast, 1,1,1-trichloropropane-2,3-oxide, an inhibitor of epoxide hydrolase activity, enhanced the activation of 6-aminochrysene catalyzed by liver microsomes from beta-naphthoflavone-treated rats and from human samples HL-16 but not HL-4, HL-13 and HL-18. Inclusion of purified rat epoxide hydrolase to the reconstituted system containing rat and human P4501A enzymes caused a decrease in the rates of 6-aminochrysene activation.(ABSTRACT TRUNCATED AT 400 WORDS)

Exacerbation of ulcerative colitis during alpha-interferon therapy for chronic hepatitis C

We report a 34-year-old man with chronic hepatitis C who showed exacerbation of ulcerative colitis during alpha-interferon (IFN alpha) therapy. Discontinuance of the IFN alpha therapy improved his symptoms, suggesting that IFN alpha administration might worsen ulcerative colitis. The administration of sulfasalazine allowed the patient to receive IFN alpha again without flare-up of ulcerative colitis. This case suggests the possible efficacy of sulfasalazine therapy in patients with ulcerative colitis complicated by some other diseases requiring IFN alpha administration.

Rat pulmonary microsomal cytochrome P-450 enzymes involved in the activation of procarcinogens

Rat lung microsomal cytochrome P-450 (P-450) enzymes have been characterized with regard to their catalytic specificities towards activation of several procarcinogens to genotoxic metabolites in Salmonella typhimurium TA1535/pSK1002. We first examined the roles of rat liver microsomal P-450 enzymes in the activation of benzo[a]pyrene and its 7,8-diol enantiomers to genotoxic products, and found that P-450 1A1 is a major catalyst for the activation of these potential procarcinogens in rat livers. Using lung microsomes isolated from rats treated with various P-450 inducers we obtained evidence that at least three P-450 enzymes are involved in the activation of several procarcinogens. Immunoinhibition studies support the view that benzo[a]pyrene and its 7,8-diol derivatives, other dihydrodiol derivatives of polycyclic aromatic hydrocarbons, and 3-amino-1-methyl-5H-pyrido[4,3-b]indole are activated to genotoxins mainly by rat P-450 1A1, which is inducible in rat lungs by 5,6-benzoflavone and the polychlorinated biphenyl mixture Aroclor 1254. Activation of 2-amino-3,5-dimethylimidazo[4,5-f]quinoline and 2-amino-3-methylimidazo[4,5-f]quinoline may be catalyzed by another P-450 enzyme because the activities were not induced by treatment with 5,6-benzoflavone or Aroclor 1254. The observation that both activities were inhibited by antibodies raised against P-450 1A2 and by 7,8-benzoflavone suggests a role for an enzyme of P-450 1A family, probably P-450 1A2, in rat lung microsomes. The activation of aflatoxin B1 and sterigmatocystin appears to be catalyzed by other P-450 enzyme(s) rather than the P-450 1A family as judged by the different responses of activities to the P-450 inducers and the specific antibodies in rat lung microsomes. Interestingly, lung microsomal activation of several procarcinogens was found to be suppressed in rats treated with isosafrole and pregnenolone 16 alpha-carbonitrile. Thus, the results support the roles of different P-450 enzymes in the activation of procarcinogens in rat lung microsomes.

Central cholinergic action produces antagonism to ketamine anesthesia

Ketamine sometimes produces posthypnotic emergency reactions, such as prolonged hallucination or delirium. In a previous paper, we showed that physostigmine, an anticholinesterase agent, counteracts the manifestation of effects of ketamine at some doses. In the present study, we investigated the mechanism of the antagonistic effect of physostigmine on ketamine anesthesia. At first, rats were given ketamine 75 mg/kg. Immediately after the loss of righting reflex, the four groups of rats were given one of the three central cholinergic agents, physostigmine 0.1 mg/kg, oxotremorine 0.05 mg/kg, 4-aminopyridine 3 mg/kg, or saline as the control. The sleeping times were 10.7 +/- 1.0, 12.3 +/- 0.9, 11.4 +/- 1.3 and 21.2 +/- 0.7 min, respectively. The three cholinergic agents antagonized ketamine anesthesia. In the other groups of rats, the central anticholinergic agent, l-hyoscyamine, 0.5 mg/kg, was given subcutaneously for premedication before the above-mentioned procedure. The sleeping times were 16.3 +/- 1.2 min in the physostigmine group, 18.7 +/- 1.0 min in the oxotremorine group and 18.6 +/- 0.8 min in the 4-aminopyridine group. The sleeping time was significantly longer in the premedicated group than in the non-premedicated group, in the case of the three central cholinergic agents. The sleeping time in the saline group, 20.0 +/- 0.4 min, was not significantly different from that of the control in the non-premedicated case. It is, therefore, considered that the central cholinergic action produces antagonism to ketamine anesthesia.

Deficits of problem-solving ability in patients with focal brain damage: neuropsychological investigation of prediction and hypothesis behavior

Deficits of problem-solving ability in focal brain-damaged patients, with special reference to frontal lobe dysfunction, were investigated by two neuropsychological tests: Temporal rule induction test and Hypothesis-testing measure. Subjects consisted of 84 chronic brain-damaged patients (31 with anterior cerebral lesions and 53 with posterior lesions). The study's aim was to investigate the effects of frontal lobe damage on two aspects of inductive reasoning, prediction and hypothesis behavior. When prediction was examined by Temporal rule induction test, patients with anterior lesions showed deficits in predicting a rule, even in the memory-aid condition in which memory factors were excluded. The poor results on Temporal rule induction test in frontal patients did not appear to be related to deficits in temporal integration, which is generally interpreted as frontal dysfunction. Rule induction may be impaired by frontal damage whenever complicated information-processing is required, even when temporal succession is not involved. Second, two stages of hypothesis behavior, hypothesis-formation and hypothesis-testing, were evaluated. Patients with anterior lesions showed impairment in hypothesis-formation. Their decreased fluency in hypothesis production affected the hypothesis-testing process. However, frontal patients committed fewer errors, most of which were perseverative (lose-stay errors) on hypothesis-testing. Patients with posterior lesions revealed other characteristic errors, such as inconsistent responses and divergent-type errors (improper lose-shift errors). The hemispheric site of the lesion affected only the ability to maintain a hypothesis (win-shift errors). The results illustrated the differences in problem-solving deficits in these two groups of patients. Disturbed prediction of future events, decreased hypothesis fluency, and abnormal lose-stay behavior in patients with frontal lobe damage may be crucial factors in coping with daily problem-solving situations.

Reduction of erythrocyte (Na(+)-K+) ATPase activities in non-insulin-dependent diabetic patients with hyperkalemia

To elucidate the mechanism of hyperkalemia in diabetic patients without renal failure, we investigated (Na(+)-K+) adenosine triphosphatase (ATPase) activity in erythrocyte membrane, erythrocyte Na+ and K+ content, and plasma endogenous digitalis-like substance in control subjects (n = 16) and non-insulin-dependent diabetes mellitus (NIDDM) patients (n = 62). NIDDM patients were divided into normokalemic patients (NKDM, n = 48) and hyperkalemic patients (HKDM, n = 14). There was no difference in plasma glucose or hemoglobin A1c (HbA1c) levels, plasma renin activity (PRA), and plasma aldosterone concentrations (PAC) between NKDM and HKDM patients. (Na(+)-K+)ATPase activities in NIDDM patients were significantly reduced compared with those in control subjects (0.336 +/- 0.016 mumol-inorganic phosphate [Pi]/mg protein/h, mean +/- SEM, P less than .05), and (Na(+)-K+)ATPase activities in HKDM patients (0.243 +/- 0.015 mumol Pi/mg protein/h) were significantly reduced compared with those in NKDM patients (0.295 +/- 0.008 mumol Pi/mg protein/h, P less than .01). Plasma K+ content had a significant negative correlation with (Na(+)-K+)ATPase activity in diabetic patients (r = -.365, P less than .01). Erythrocyte Na+ content had a significant negative correlation with (Na(+)-K+)ATPase activity in control subjects (r = -.619, P less than .05). There was no difference in plasma endogenous digitalis-like substance among the three groups. (Na(+)-K+)ATPase activity was not significantly correlated with plasma endogenous digitalis-like substance in control subjects and diabetic patients. These findings suggest that the reduction of (Na(+)-K+)ATPase activity, which was not related to plasma digitalis-like substance, may be partly responsible for hyperkalemia in diabetic patients.

Defects in insulin binding and receptor kinase in cells from a woman with type A insulin resistance and from her family

Defects in insulin receptor function lead to impairment of the insulin response. We treated a patient with the typical phenotype of type A syndrome of insulin resistance whose insulin receptor seemed to lack the transmembrane region and cytoplasmic domain. Hyperinsulinaemia and resistance to exogenous insulin were evident, and insulin binding to cells and uptake of 2-deoxyglucose into fibroblasts were greatly decreased. Molecular weight of the alpha-subunit of the insulin receptor was normal, but autophosphorylation and kinase activity were impaired. In the pedigree analysis, defects in insulin binding were also observed in the mother, maternal grandfather and two maternal aunts, corresponding with the abnormality of the insulin receptor gene and mild insulin resistance. In the mother, much the same kinase defects as were seen in the patient became evident. However, no relatives had clinical symptoms similar to those seen in the patient. In the father there was a mild insulin resistance in the glucose clamp study and a borderline impaired glucose tolerance. Although insulin binding to cells was normal in the father, both autophosphorylation and kinase activity were reduced. Our findings suggest that insulin resistance in the patient may be caused by the defects in insulin receptor kinase activity as well as by a reduction in insulin binding activity.

Long-term results of anterior interbody fusion for treatment of degenerative spondylolisthesis

Thirty-nine patients, 34 women and five men, underwent anterior decompression and interbody fusion for degenerative spondylolisthesis between February 1958 and August 1988. Their average age at surgery was 51 years (range, 34-74 years), and their average follow-up period was 12 years 7 months (range, 6 months to 30 years). Clinical evaluation was done by the score rating system of the Japanese Orthopaedic Association (JOA Score). Patients with JOA scores of 25 points or more were rated as "satisfactory." Survivorship was analyzed by the method of Kaplan and Meier to determine the cumulative percentage of patients with satisfactory results. The following results were obtained: Seventy-six percent of the patients had satisfactory results for 10 years after the anterior interbody fusion, 60% for 20 years, and 52% for 30 years. Irrespective of their age at surgery, the patients generally maintained satisfactory results up to 65 years of age.

[Rotational instability of the lumbar spine--a three-dimensional motion study using bi-plane X-ray analysis system]

The purpose of this study is to investigate the rotational instability of the lumbar spine using bi-plane X-ray analysis system and to clarify mechanical etiology of the lumbar instability. The following results were obtained. (1) The range of rotational motion was about 2 to 3 degrees at each motion segment in the normal lumbar spine. The rotational motion was significantly large in spondylolysis, spondylolisthesis, and degenerative spondylolisthesis. (2) The rotational instability and the flexion-extension instability correlated to each other in spondylolysis and spondylolisthesis. However, in degenerative spondylolisthesis, the rotational instability and the antero-posterior instability were correlated to each other. (3) Instantaneous axis of rotation (IAR) was located at the posterior part of the intervertebral disc in the normal L4 vertebra, and more posteriorly in the L5 vertebra, while the IAR was located anteriorly in spondylolysis, and posteriorly in degenerative spondylolisthesis. (4) When the trunk was twisted, the lumbar lordotic angle was generally decreased, and the lumbar spine showed scoliotic curvature convex to the twisted direction. The apex was located at the L4/5 intervertebral level. Highly significant increases in flexion motion associated with rotation were observed at the pathological levels of spondylolysis and degenerative spondylolisthesis.

Antagonistic effect of physostigmine on ketamine-induced anesthesia

Effects of physostigmine on ketamine-induced anesthesia and analgesia were studied in male Sprague-Dawley rats using behavioral tests. Rats were divided into six groups. Immediately after loss of the righting reflex following an intraperitoneal injection of ketamine 75 mg/kg, each group of rats was given an intraperitoneal injection of either physostigmine 0.05, 0.1, 0.2, 0.4, 0.6 mg/kg or saline as the control, respectively. Physostigmine 0.1 mg/kg caused the greatest antagonistic effect on ketamine anesthesia as indicated by sleeping time, duration of ataxia and motor coordination. The antagonistic effects of physostigmine were reduced by a dose of physostigmine of greater than 0.1 mg/kg. However, at no dose did physostigmine antagonize ketamine analgesia as indicated by the tail-flick latency. Physostigmine (0.4 and 0.6 mg/kg) itself had analgesic and motor-suppressive actions. It can therefore be presumed that there is a limited threshold of the dose of physostigmine which develops an antagonistic effect on ketamine anesthesia due to the motor-suppressive action. It is also confirmed that physostigmine itself produces analgesia, and does not antagonize ketamine-induced analgesia.

Three-dimensional motion analysis of the cervical spine with special reference to the axial rotation

The purpose of this study is to obtain basic data on the rotational motion of the cervical spine. Twenty normal men aged 25 to 31 years were investigated. Biplanar roentgenograms of the neck with the head held in neutral and maximally rotated positions were taken in a reference frame. Three sets of x-ray films were measured using a three-dimensional analysis system composed of a digitizer and a personal computer. Total axial rotation was 105 degrees on an average between the occiput and the C7 vertebra. Seventy percent of the total axial rotation occurred between the occiput and the C2 vertebra. Each motion segment between the C2 and C7 vertebrae showed from 4 degrees to 8 degrees rotation on an average. When the head was rotated, lateral bending occurred by coupling in the same direction as rotation at each segment below the C3-C4 level, and in the opposite direction above the C2-C3 level. At the same time, flexion took place by coupling at each segment below the C5-C6 level, and extension above the C4-C5 level.

[Evaluation of toxic effects on yusho causal substances by chick embryo hepatic microsomal enzymes activities]

PCBs, non-ortho chlorine substituted PCBs (Co-PCBs), PCQs and (PCDFs + PCDDs), all of which contained similar compositions of those corresponding in yusho oil, were prepared from a PCB preparation used as a heat exchanger fluid. After dissolved in 1, 4-dioxane, they were applied into the air sac of white leghorn eggs incubated for 16.5 days at 37.5 degrees C. Forty eight hours after injection, the hepatic benzo(a)pyrene hydroxylase (AHH) and 7-ethoxyresorufin deethylase (EROD) activities were assayed. The average relative potencies of induction for the two microsomal drug metabolizing enzymes by (PCDFs + PCDDs), Co-PCBs, PCBs and PCQs were 100, 13.4, 0.0006 and 0.0004, respectively. The toxic effects for yusho disease by these substances were calculated from the relative enzyme induction potencies and the average concentrations in yusho oils with the production dates of February 9 and 10, 1968. Consequently, the relative toxicities of (PCDFs+PCDDs), Co-PCBs, PCBs and PCQs were 100, 13.2, 0.06 and 0.12, respectively. This result, as well as our previous investigations using rats and monkeys, insists that (PCDFs+PCDDs) are the primary causal agents for yusho disease. However, the Co-PCBs, which were recently detected in the yusho oils by us, were revealed to be fairly effective in yusho manifestation. In addition, it was cleared that the hepatic enzyme induction by the Co-PCBs fraction, which contained other several PCB isomers, was almost completely contributed by only Co-PCBs such as 3,4,3',4'-tetra- 3,4,5,3',4'-penta- and 3,4,5,3',4',5'-hexachlorinated biphenyls present in the fraction. A chemical uptake rate from the air sac by the chick embryo decreased significantly in the cases of extremely high doses of PCBs (10,000 micrograms/egg) and PCQs (3,333 and 10,000 micrograms/egg), and result the elevations of hepatic enzymes activities were depressed, indicating that the suitable chemical dose amount to be less than about 1,000 micrograms/egg.

[Penicillin insensitive and resistant Streptococcus pneumoniae infection in children]

Five cases of penicillin insensitive or resistant pneumococcal infection in children were experienced during the period of 2 years since March, 1986. One isolate from middle ear showed the MIC of 4 micrograms/ml against penicillin-G. One isolate of insensitive pneumococcus was isolated from CSF specimen. Between 1976 and 1987, 59 isolates from 88 stocked pneumococcal clinical isolates were alive. These 59 strains were screened by oxacillin disc for insensitive and resistant pneumococcus. Five strains which were insensitive or resistant strains had inhibitory zone under 20 mm. The prevalence rate of insensitive or resistant pneumococcus since 1986 was 18%.

[High-dose CDDP therapy using a balloon-occluded arterial infusion (BOAI) in recurrent ovarian cancer]

An intraarterial high-dose CDDP, using a balloon catheter, has been infused into five patients with a recurrent ovarian cancer. The dose of CDDP was 150 mg-200 mg/body. Two patients experienced a partial tumor regression, whereas three showed no change. With regard to the toxicity, the NAG index (NAG activity/urinary creatinine) rose markedly in all patients, but toxicity was almost similar to that seen from a systemic administration. No significant catheter complication occurred.

Partial purification of androgen receptor from hypertrophic human prostate

For purification of androgen receptor from hypertrophic human prostate, solutions used for elution of androgen receptor from DNA Sepharose, affinity labeling of the receptor and ability of affinity gel to retain the receptor were examined. Elution with 20 mM pyridoxal 5'-phosphate of the receptor from DNA Sepharose was more efficient than that with diluted pyridoxal 5'-phosphate, high ionic solution or various concentrations of Mg++, 3H-dihydrotestosterone bromoacetate was applicable to covalent binding with partially purified androgen receptor regardless of the low specificity of the ligand. Affinity gel of thiopropyl-Sepharose 6B coupled to 17 alpha-(2', 3'-epoxy-propyl)-5 alpha-dihydrotestosterone was better than Affigel 102 coupled to N-[3-(3-oxo-5 alpha-androstane-17 beta-yloxycarbonyl) propionyloxy] succimide or aminoethyl-Sepharose 4B coupled to 17 alpha-carboxyethynyl testosterone with respect to the rate of retention of androgen receptor. In view of these observations, the following purification procedures were constructed: Removal of DNA Sepharose-binders from the cytosol, 40% ammonium sulfate precipitation, affinity chromatography using thiopropyl-Sepharose 6B coupled to 17 alpha-(2',3'-epoxypropyl)-5 alpha-dihydrotestosterone, and DNA Sepharose chromatography. After affinity labeling of the receptor thus obtained, the molecular weight was estimated. Some 1300-fold purification with a yield of 0.25% of the androgen receptor was achieved. The molecular weight of the receptor was mainly 45 K with 90 K in a lesser amount. The Stokes radius was calculated as 30 A.

Purification of a kininogenase from the venom of Agkistrodon caliginosus (Kankoku-Mamushi)

During the isolation of a capillary permeability-increasing enzyme from the venom of A. caliginosus, a kininogenase was also purified from the venom by gel filtration on Sephadex G-100, ion-exchange chromatographies on CM-Sephadex C-50 and DEAE-Sephadex A-50, and gel filtration on Sephadex G-75. By this procedure, 11 mg of the purified enzyme were obtained from 4 g of the venom. The purified enzyme was homogeneous by polyacrylamide disc gel electrophoresis at pH 8.3 and sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and did not show any caseinolytic or clotting activity. The purified enzyme released bradykinin from purified bovine high mol.wt kininogen. The capillary permeability was increased by injection of the purified enzyme into the depilated skin of the back of a rabbit. It is supposed that the capillary permeability-increasing activity exerted by the enzyme is due to the release of bradykinin.

Some properties of a kininogenase from the venom of Agkistrodon caliginosus (Kankoku-Mamushi)

A kininogenase (bradykinin-releasing enzyme) from the venom of A. caliginosus, is a single polypeptide-chain glycoprotein with a mol.wt of about 33,500, which contains 10.1% carbohydrate. The isoelectric point of the enzyme is 3.5 and the enzyme has 274 amino acid residues based on the mol.wt of 33,500. The enzyme hydrolyzed arginine esters more readily than lysine esters, but did not hydrolyze tyrosine ester. The activity of the enzyme on hydrolysis of arginine ester or on liberation of kinin from purified bovine high mol.wt kininogen was inhibited by diisopropylfluorophosphate, indicating that the serine hydroxyl group is involved in enzymatic activity. Moreover, the enzyme split N-alpha-carbobenzoxy-Gly-Pro-Arg-p-nitroanilide (PNA), H.D.Val-Leu-Arg-PNA, H.D.Pro-Phe-Arg-PNA, H.D.Phe-pipecolyl-Arg-PNA and Pro-Phe-Arg-4-methylcoumaryl-7-amide more readily than the other chromogenic or fluorogenic substrates. This result indicates that the substrate specificity of the enzyme is broader than that of mammalian serine proteinases.

Pattern formation in interacting and diffusing systems in population biology

In this article, we have been mainly concerned with spatially non-uniform stationary states and their stability, motivated by pattern formation arising in population biology. The discussions are restricted to one-dimensional space, though real systems are always distributed in at least two-dimensional space. Even if we limit ourselves to small-amplitude solutions, it seems difficult to discuss the bifurcation problems in a manner similar to that for one-dimensional space. One of the reasons is that the bifurcation points are not easily found. However, some general theories have nearly been completed. There are a variety of phenomena of other patterns such as wave trains, wave fronts, pulse waves, target patterns, and rotating patterns in equations of reaction and diffusion. We have not discussed these here. Moreover, we emphasize that there are a lot of nonlinear diffusion problems which are different from the ones that were dealt with here. The book of Fife (1), for example, provides a good exposition on these problems.