Chlorzoxazone is metabolized by human CYP1A2 as well as by human CYP2E1

Chlorzoxazone, a muscle-relaxing drug, is metabolized by carbon-hydroxylation at position 6. Chlorzoxazone has been suggested as an in vivo probe for CYP2E1. We studied the specificity of such a substrate using vaccinia virus expressed human P450 forms and the effect of inhibitors for chlorzoxazone metabolism by human liver microsomes. The 6-hydroxylation of chlorzoxazone was mediated by CYP1A2 as well as by CYP2E1. The Km value of CYP1A2 and CYP2E1 for the reaction was 5.69 microM and 232 microM, respectively. However, the Vmax value of CYP2E1 for the reaction was approximately 8.5-fold higher than that of CYP1A2. The CYP1A inhibitor, alpha-naphthoflavone, as well as the CYP2E1 inhibitor, diethyldithiocarbamate, decreased chlorzoxazone 6-hydroxylation at a low substrate concentration by human liver microsomes. Our results raise questions about the suitability of chlorzoxazone as an in vivo probe for hepatic CYP2E1 activity. In human liver microsomal samples, the Km = 40 microM was different from either the Km of CYP1A2 or CYP2E1. We think that this discrepancy is due to the co-expression of similar levels of CYP1A2 and CYP2E1 in human liver. Furthermore, it is suggested that the role of CYP2E1 in 6-hydroxychlorzoxazone formation at the physiological chlorzoxazone concentration of 30-60 microM is almost the same when compared to that of CYP1A2.

Oxidative metabolism of bunitrolol by complementary DNA-expressed human cytochrome P450 isozymes in a human hepatoma cell line (Hep G2) using recombinant vaccinia virus

We examined the oxidative metabolism of a beta-blocker bunitrolol (BTL) by 10 human cytochromes P450 (CYP) (1A2, 2A6, 2B6, 2C8, 2C9, 2D6, 2E1, 3A3, 3A4 or 3A5), which were individually expressed in Hep G2 cells with a vaccinia virus complementary DNA expression system. Among the 10 isozymes, only CYP2D6 and 1A2 at a substrate concentration of 5 microns, and CYP2C8 and 2C9 in addition to the two isozymes at a BTL concentration of 1 mM, exhibited detectable BTL 4-hydroxylase activities. The activities at 1 mM BTL were on the order of CYP2D6 (100% as relative activity) > CYP1A2 (86%) >> CYP2C8 and 2C9 (7-8%). Enzyme kinetic parameters of CYP2D6 were calculated to be 4.41 microns as a Km value and 0.442 nmol min-1 per nmol CYP as a Vmax value. Kinetic parameters of CYP1A2 were calculated as 295 microns and 0.411 nmol min-1 per nmol CYP for Km and Vm values, respectively. These results suggest that both CYP2D6 and 1A2 primarily catalyse BTL 4-hydroxylation, but that the former is a predominant isozyme responsible for the reaction at a low substrate concentration range of BTL in human liver.

Correlation of activation of Ca2+/calmodulin-dependent protein kinase II with catecholamine secretion and tyrosine hydroxylase activation in cultured bovine adrenal medullary cells

We have investigated the activation of Ca2+/calmodulin-dependent protein kinase II (CaM kinase II) in cultured bovine adrenal medullary cells. The activation was assayed as an increase in the Ca(2+)-independent (autonomous) activity of CaM kinase II, using the synthetic substrate Syntide-2. Incubation of cells with acetylcholine increased the Ca(2+)-independent activity in a time (20 sec to 5.0 min)- and concentration (10-300 microM)-dependent manner. These curves were closely correlated with those of catecholamine secretion and tyrosine hydroxylase activation. Removal of extracellular Ca2+ completely abolished the stimulatory effects of acetylcholine on the Ca(2+)-independent activity, as well as on catecholamine secretion and activation of tyrosine hydroxylase. Nicotine but not muscarine increased the Ca(2+)-independent activity as potently as did acetylcholine, and hexamethonium but not atropine completely blocked the acetylcholine-induced increase. In 32P-labeled cells, acetylcholine stimulated the phosphorylation of a 50-kDa protein that was immunoprecipitated with an anti-brain CaM kinase II antibody. These results suggest that acetylcholine stimulates CaM kinase II activity through nicotinic acetylcholine receptor-mediated influx of Ca2+ and that the activation of CaM kinase II is closely related to catecholamine secretion and tyrosine hydroxylase activation in cultured adrenal medullary cells.

Glycine 85 of the trp-repressor of E. coli is important in forming the hydrophobic tryptophan binding pocket: experimental and computational approaches

Experimental and computational analyses were performed on the corepressor (L-tryptophan) binding site of the trp-repressor of Escherichia coli to investigate the ligand-protein interactions. Gly85, one of the residues forming the hydrophobic pocket of the binding site, was systematically replaced with Ala, Val, Leu and Trp by cassette mutagenesis. Biochemical characterization showed that all these mutations caused significant decreases in tryptophan binding activity. Free energy perturbation calculations were performed for the mutants and were consistent with the experimental results. The lack of a side chain at position 85 was concluded to be essential for binding the corepressor; the structure of the binding pocket was suggested to be tight in the vicinity of Gly85.

Endothelial Gi protein in human coronary arteries

Endothelium-dependent relaxations mediated by Gi protein are prominently impaired in atherosclerotic coronary arteries. However, it remains to be determined whether the expression of endothelial Gi protein per se is reduced in coronary atherosclerosis. Thus, in the present study the expression of endothelial Gi protein was examined by immunohistochemical staining using a specific antibody against human Gi protein (alpha-subunits of Gi-1 and Gi-2 proteins) in the proximal segment of the left anterior descending coronary arteries (segment 6) from 40 consecutive autopsy cases. The immunoreactive level of the Gi protein was semi-quantitated in four grades (none, 0; slight, +; moderate, +2; high, +3) and the mean value of the ratings of all endothelial cells was used as an index of the endothelial Gi protein expression of the artery. The immunoreactive level of the Gi protein in human coronary arteries was significantly reduced with ageing and extent of coronary atherosclerosis (both P < 0.05), and was lower in patients with than in those without hypertension (P < 0.01) or hyperlipidaemia (P < 0.05). In addition, the level was significantly lower in the eccentric portions than in the concentric ones in each atherosclerotic coronary artery (P < 0.0001). These alterations in the immunoreactive level of endothelial Gi protein in human coronary arteries may explain, in part, why Gi protein-mediated, endothelium-dependent relaxations are prominently impaired in atherosclerosis.

Different change in lipoprotein(a) levels from lipid levels of other lipoproteins with improved glycemic control in patients with NIDDM

OBJECTIVE

To evaluate change both in lipoprotein(a) [Lp(a)] and lipid levels in other lipoproteins in non-insulin-dependent diabetes mellitus (NIDDM) after short-term improvement of glycemic control.

RESEARCH DESIGN AND METHODS

We compared Lp(a) levels in 210 NIDDM patients with those in 46 control subjects and evaluated the relationship between glycemic control and Lp(a) levels in diabetic patients. In addition, changes in Lp(a) levels and lipid levels were assessed after the improvement of glycemic control in 54 poorly controlled NIDDM patients.

RESULTS

In NIDDM, Lp(a) levels in all patients, 62 patients with HbA1c < 6.0%, and 75 patients with HbA1c between 6.0 and 8.0%, were significantly higher than those in control subjects (19.1 [1.7-106.6], 19.2 [6.0-106.6], and 20.3 [2.7-75.3] vs. 15.4 [2.0-61.7] mg/dl, median [range], P < 0.05). Lp(a) levels in 73 patients with HbA1c of > or = 8.0% (18.7 [1.7-58.8] mg/dl) were not significantly different from those in control subjects. After glycemic control, lipid levels in plasma and in other lipoproteins fell significantly, but Lp(a) did not change (from 18.3 [1.7-58.8] to 18.4 [6.6-95.3] mg/dl). Changes in lipid levels, including Lp(a), did not correlate with those in fasting plasma glucose or HbA1c.

CONCLUSIONS

These results suggest that elevated Lp(a) levels do not reflect poor glycemic control and that Lp(a) levels are independent of lipid levels in other lipoproteins after improved glycemic control in NIDDM.

Occurrence and activation of Ca2+/calmodulin-dependent protein kinase II and its endogenous substrates in bovine adrenal medullary cells

We investigated the presence of and the endogenous substrates for Ca2+/calmodulin-dependent protein kinase II (CaM kinase II) in cultured bovine adrenal medullary cells. By a series of chromatographic steps using DEAE-cellulose, calmodulin affinity, and Sephacryl S-300 columns, we partially purified two CaM kinases (peaks I and III) and one calmodulin-binding protein (peak II). Both of the kinases (peaks I and III) showed broad substrate specificities. Peak I, but not peak III, was immunoprecipitated with an antibody against rat brain CaM kinase II, suggesting that peak I is CaM kinase II or a closely associated CaM kinase. Although the anticaldesmon antibody recognized a 77-kDa protein (low molecular mass caldesmon) in crude preparations from the cells, the protein in peak II was not immunoblotted with the antibody. The peak II protein was phosphorylated by the CaM kinase in peak I but not by the CaM kinase in peak III. Peak I kinase also phosphorylated purified tyrosine hydroxylase and several proteins from chromaffin granule membranes. Stimulation of cultured bovine adrenal medullary cells with 56 mM K+ evoked rapid increases in 45Ca2+ influx and autonomous CaM kinase II activity, both of which were attenuated by the addition of 20 mM MgSO4, an inhibitor of voltage-dependent Ca2+ channels. These results suggest that an isozyme of CaM kinase II exists in adrenal medullary cells and is activated by cell depolarization. Furthermore, the peak II protein is apparently a novel endogenous substrate for CaM kinase II.

C-type natriuretic peptide increases cyclic GMP in rat cerebral microvessels in primary culture

Effect of CNP on cGMP level in cultured rat cerebral microvessels was investigated. The cerebral microvessels were prepared from rat cerebral cortex by dispase and collagenase digestion and Percoll gradient centrifugation, and cultured. CNP increased cGMP level in a dose-dependent manner suggesting that CNP has a regulatory role in the cerebral microvessel function.

Lipoprotein(a) as an independent risk factor for diabetic retinopathy in male patients in non-insulin-dependent diabetes mellitus

Relationship of the lipoprotein(a) [Lp(a)] concentration as a risk factor independent of other factors with the severity of diabetic retinopathy were evaluated by multiple regression analysis. The subjects were 158 patients with non-insulin-dependent diabetes mellitus (NIDDM). Multiple regression analysis was carried with the severity of diabetic retinopathy as the dependent variable and 13 independent variables, namely the Lp(a) concentration, sex, age, body mass index, duration of diabetes, ischemic heart disease, fasting plasma glucose, glycosylated hemoglobin A1c, total cholesterol, triglyceride, high-density lipoprotein cholesterol, anti-diabetic treatments, and diabetic nephropathy. The analysis was performed separately in all subjects, males only, and females only. The standard partial regression coefficient of Lp(a) was significant (0.293, p < 0.01), and the multiple correlation coefficient was 0.611 in the males. However, the standard partial correlation coefficient of Lp(a) was not significant in all patients and in females only. The rank of contribution of Lp(a) to retinopathy was the third in males, following triglyceride and nephropathy and followed by anti-diabetic treatments. These results suggest that Lp(a) might be an independent risk factor for diabetic retinopathy in male patients with NIDDM.

Three types of "mid-band" lipoproteins in non-insulin-dependent diabetes mellitus: relation to metabolic abnormalities and vascular complications

A number of fine bands which occur in positions between the beta- and pre-beta-lipoproteins in polyacrylamide gell electrophresis are called mid-bands (MB). In this study, the relationship between the occurrence of these MB and metabolic abnormalities or vascular complications was evaluated in 181 patients with non-insulin-dependent diabetes mellitus (NIDDM). The incidence of MB in diabetic patients was significantly higher than that in 149 healthy control subjects (35 vs. 20%, p < 0.01). Analysis according to the type of MB revealed that the incidence of the central type in diabetic patients was significantly higher than that in healthy control subject (11 vs. 5%, p < 0.05). When the values of HbAlc were elevated, the incidence of MB and its central type slightly increased. The occurrence of the lower type of MB showed no relationship with the levels of HbAlc. The incidence of MB and its central type were significantly higher in patients with type IIb hyperlipidemia (86 and 41%, respectively) and with type IV hyperlipidemia (63 and 25%) than in those with normolipidemia (21 and 5%) (p < 0.01 of all). The incidence of the lower type of MB was significantly higher in patients with type IIa hyperlipidemia (25%) and with type IIb hyperlipidemia (36%) than in those with normolipidemia (11%) (p < 0.05, p < 0.01, respectively). There was no significant difference in the occurrences of MB and of the central and lower types of MB between the normolipidemic patients and healthy control subjects. The incidence of MB and its central type were significantly higher in patients with nephropathy (54 and 23%, respectively) than in those without nephropathy (32 and 9%) (p < 0.05 of all). There was no significant difference in the incidence of lower type of MB between patients with and without nephropathy. These results indicate that the incidence of central type of MB may be high in NIDDM, and that the occurrence of central type may be associated with abnormal metabolism of glucose or lipid and with diabetic nephropathy.

Lipid composition of platelets in patients with non-insulin-dependent diabetes mellitus: studies before and after treatment of diabetes

The study was designed to investigate whether impaired composition of platelet lipids in untreated diabetic patients improved after diabetic treatment. Fourteen untreated patients with non-insulin-dependent diabetes mellitus (NIDDM) and 15 healthy control subjects were studied. In the diabetic patients, the ratio of free cholesterol to phospholipid (FC/PL) in platelets of 0.33 +/- 0.02 (mean +/- SEM) at pre-treatment, which was statistically (p < 0.05) higher than that of 0.26 +/- 0.02 in control subjects, was significantly decreased to the value of 0.29 +/- 0.02 (p < 0.01) after insulin therapy. Platelet FC level of 9.77 +/- 0.77 micrograms 10(-8) cells pre-treatment was significantly (p < 0.01) reduced to the value of 7.72 +/- 0.38 micrograms 10(-8) cells post-treatment. Platelet PL level showed no significant changes after the treatment. There was a significantly (p < 0.01) positive correlation between the decrease in FC/PL of platelets and that in haemoglobin A1c (HbA1c) after treatment for diabetes (rs = -0.729). These results indicate that the impaired lipid composition in platelets can be improved after an adequate glycaemic control in patients with NIDDM.

Clinical characteristics in non-insulin-dependent diabetic patients with long duration in Japan--relation to risk factors for vascular complications

In this study, we evaluated the control state of body weight, blood pressure, and blood glucose during the recent 10 years in 82 patients of non-insulin-dependent diabetes mellitus (NIDDM) who had long duration of diabetes for 20-25 years without ischemic heart disease (IHD) and diabetic nephropathy (Neph). The patients without either IHD or Neph showed significantly lower incidences of obese (11 vs. 40%, p < 0.05), hypertensive (0 vs. 20%, p < 0.05) and poor glycemic control state (7 vs. 27%, p < 0.05) for 10 years than the patients with IHD alone, and showed significantly lower incidences of hypertensive (0 vs. 20%, p < 0.05) and poor glycemic control state (7 vs. 33%, p < 0.01) than the patients with Neph alone. The control state of body weight was similar between the patients without either IHD or Neph and with Neph alone. In addition, the patients without either IHD or Neph showed significantly lower incidences of obese (11 vs. 56%, p < 0.01) and hypertensive control state (0 vs. 40%, p < 0.01) for 10 years than the patients with both IHD and Neph. The control state of blood glucose was similar between the two groups. These results suggest that for long survival of NIDDM patients without development or progression of IHD and Neph, non-obese and non-hypertensive state as well as good glycemic control should be maintained for long time.

Isoflurane inhibits nicotinic acetylcholine receptor-mediated 22Na+ influx and muscarinic receptor-evoked cyclic GMP production in cultured bovine adrenal medullary cells

The effects of isoflurane on 22Na+ influx, 45Ca2+ influx, catecholamine secretion and cyclic GMP production induced by three kinds of secretagogue (nicotinic agonists, veratridine and a high concentration of K+) have been investigated using cultured bovine adrenal medullary cells. (1) Isoflurane (1-6%) inhibited catecholamine secretion stimulated by carbachol, nicotine and dimethyl-4-phenylpiperazinium in a concentration-dependent manner. Isoflurane suppressed carbachol-evoked 22Na+ influx and 45Ca2+ influx at concentrations similar to those which suppressed catecholamine secretion. The inhibition of catecholamine secretion by isoflurane was not overcome by increasing the concentration of carbachol. (2) The inhibitory effects of isoflurane on veratridine-induced 22Na+ influx, 45Ca2+ influx and catecholamine secretion became evident when the concentration of isoflurane was raised to 4-6%, i.e. 2-3 fold higher than the concentrations (1-2%) employed clinically. (3) High K(+)-evoked 45Ca2+ influx and catecholamine secretion were not affected by isoflurane (1-6%). (4) Isoflurane (1-6%) attenuated the production of cyclic GMP caused by muscarine, but not that caused by atrial natriuretic peptide or by sodium nitroprusside. These results suggest that isoflurane, at clinical anesthetic concentrations, inhibits nicotinic acetylcholine receptor-mediated cell responses as well as muscarinic receptor-mediated cyclic GMP production in adrenal medullary cells.

C-type natriuretic peptide stimulates catecholamine synthesis through the accumulation of cyclic GMP in cultured bovine adrenal medullary cells

We examined the effects of C-type natriuretic peptide (CNP) on cyclic GMP production and catecholamine synthesis in cultured bovine adrenal medullary cells. 1) CNP increased intracellular cyclic GMP content in a concentration-dependent manner (10-1000 nM). 2) The cyclic GMP production induced by 1 microM CNP reached a 200-fold increase, and the effect of CNP was most potent among the natriuretic peptide family. 3) The CNP-induced cyclic GMP production was attenuated by endothelin (1 microM) and angiotensin II (0.1-1 microM). 4) When the cells were cultured with hypertonic NaCl medium, the CNP-induced cyclic GMP production was potentiated in a time (1-4 days)- and concentration (25-100 mM)-dependent manner. 5) CNP stimulated the synthesis of 14C-labeled catecholamines from [14C] tyrosine but not from [14C] dopa. The stimulatory effect of CNP on the 14C-labeled catecholamine synthesis was observed at the concentrations of 100 to 100 nM. 6) 8-Bromo cyclic GMP, a membrane-permeable cyclic GMP analog, and sodium nitroprusside, an activator of soluble guanylate cyclase, also stimulated the synthesis of 14C-labeled catecholamines from [14C]tyrosine, whereas C-ANF, a specific ligand for the ANP-C (clearance) receptor that does not increase cyclic GMP content, failed to stimulate the synthesis of 14C-labeled catecholamines. 7) CNP (1 microM) as well as 8-bromo cyclic GMP and sodium nitroprusside increased the activity of tyrosine hydroxylase in the cells. These results suggest that in the adrenal medulla, CNP is a potent agonist for cyclic GMP production, which is modulated by endothelin, angiotensin II and the hypertonic NaCl condition.(ABSTRACT TRUNCATED AT 250 WORDS)

Mutagenicity of blue rayon extracts of human bile in the Ames test

The mutagenicity of human bile was examined in the Ames Salmonella/microsome assay. Bile samples were obtained from the gallbladders resected from patients with cholelithiasis, choledocholithiasis, gallbladder cancer, extrahepatic bile duct cancer and other diseases. For extraction of mutagenic components, the bile samples were treated with blue rayon and the adsorbed materials were assayed with Salmonella typhimurium TA98 in the presence of S9 mix. Twenty-four bile samples were tested and positive mutagenic activity was found in 14 samples. A 200-microliter bile equivalent material gave 6.3 times as many revertant colonies as the solvent control. With several samples that had undergone two cycles of blue rayon extraction, clear dose-response relationships in mutagenicity were demonstrated.

Receptors for C-type natriuretic peptide in cultured rat glial cells

To characterize sites of action of C-type natriuretic peptide (CNP) in the glial cells, the effect of CNP on cGMP accumulation and the binding of [125I]CNP in rat astrocyte RCR-1 cells were studied. CNP stimulated cGMP accumulation in the cells from 10(-9) M in a dose-dependent manner, but ANP (atrial natriuretic peptide) had a negligible effect on cGMP accumulation in the cells. [125I]CNP was bound to the cells and its Kd value was 2 orders of magnitude lower than that of the ED50 value for stimulation of cGMP accumulation in the cells. Not only CNP but also ANP displaced [125I]CNP binding to the cells. These results suggest that RCR-1 cells have a B-receptor which contains a guanylate cyclase domain and is preferentially activated by CNP, and that they also have a C-receptor which does not contain a guanylate cyclase domain that reacts with both ANP and CNP.

Intracellular magnesium deficiency in acute myocardial infarction

It has been hypothesized that intracellular magnesium deficiency is a pathogenetic factor in acute myocardial infarction. This study examined the time course of changes in the erythrocyte magnesium concentration and the correlation between the erythrocyte magnesium concentration and the severity of acute myocardial infarction in 49 consecutive patients with transmural acute myocardial infarction. The data were compared with results from 20 control patients without ischemic heart disease. The erythrocyte magnesium concentration (mg/dl) decreased significantly during the acute phase of the infarction (4.86 +/- 0.09 on day 1, 4.89 +/- 0.10 on day 2 and 4.86 +/- 0.10 on day 3 versus 5.26 +/- 0.19 for controls, all P < 0.05) and then normalized gradually to 5.25 +/- 0.10 on day 28. The serum magnesium concentration (mg/dl) also decreased significantly during the acute phase of the infarction (1.93 +/- 0.04 on day 1 and 2.11 +/- 0.03 on day 2 versus 2.26 +/- 0.08 for controls, all P < 0.05), before recovering to 2.28 +/- 0.06 on day 28. There were significant correlations between the erythrocyte magnesium concentration on day 1 and maximal values of serum cardiac enzymes (r = -0.30 for creatine kinase, r = -0.34 for glutamic oxaloacetic transaminase and r = -0.57 for lactate dehydrogenase, all P < 0.05). Moreover, the erythrocyte magnesium concentration was significantly lower in patients with (4.32 +/- 0.08 mg/dl, n = 13) than in those without (5.06 +/- 0.09 mg/dl, n = 36, P < 0.0001) serious arrhythmias. These data indicate that intracellular magnesium deficiency is involved in the acute phase of myocardial infarction.

Alcohol-induced sinus bradycardia and hypotension in patients with syncope

We observed 2 cases of repeated episodes of syncope after alcohol ingestion. Both patients were light drinkers and had carotid sinus hypersensitivity. In both cases, alcohol loading tests repeatedly induced sinus bradycardia and hypotension 1.0-1.5 hours after drinking alcohol. Atropine was effective in improving symptoms. A loading test using a glucose solution of equivalent osmolarity and volume was negative. Acute alcohol ingestion usually increases heart rate with variable effects on blood pressure. However, our 2 cases exhibited unusual alcohol-induced sinus bradycardia and hypotension, suggesting a paradoxical increase in parasympathetic activity and/or decrease in sympathetic activity.

Flow cytometric analysis of pig epidermal keratinocytes: effects of tape stripping

Tape stripping is a dynamic in vivo model for the induction of synchronized keratinocyte proliferation. We investigated the cell kinetics of pig epidermis by DNA-flow cytometric analysis, which was compared with [3H]thymidine incorporation mitotic counts and 2-[3H]-deoxy-D-glucose uptake. The stripping was standardized and confirmed histologically by the observation of complete removal of horny layer. Following the stripping, the proportion of cells in S-phase showed no remarkable change until 12 h. This was followed by a spike-like increase in the S-phase cells, the peak of which was reached at 24 h. This gradually decreased and returned to basal levels by 48 h. The cells in G2/M fraction initially decreased; the lowest value was obtained at 12 h. This was followed by a marked increase in the G2/M fraction, the peak of which was at 36 h. The keratinocytes in G2/M fraction gradually returned to basal levels by 96 h. [3H]Thymidine uptake and mitotic counts were mostly parallel with the data of the flow cytometric analysis, suggesting the latter as being a reliable system for cell kinetic analysis. The glucose uptake initially decreased (at 6 h following the stripping) and then increased at 24 h. Histologically the stripped epidermis regained its horny layer almost completely by 72 h following the stripping; this was occasionally accompanied by a moderate acanthotic change thereafter.

Acid cholesteryl ester hydrolase activity of mononuclear leukocytes in patients with non-insulin-dependent diabetes mellitus: studies before and after treatment of diabetes

The change of acid cholesteryl ester hydrolase activity in mononuclear leukocyte following treatment of diabetes mellitus was studied in 21 patients with non-insulin-dependent diabetes mellitus (NIDDM). Enzyme activity before treatment in the patients was significantly lower than that in 14 age-matched healthy subjects (1.20 +/- 0.15; mean +/- S.E. vs. 2.20 +/- 0.17 nmol/mg protein/h, P less than 0.01). Enzyme activity before treatment in the patients was significantly increased (P less than 0.05) after 4-8 weeks of treatment. However, enzyme activity of 1.43 +/- 0.14 nmol/mg protein/h observed after treatment in the patients was significantly lower (P less than 0.01) than that in the healthy subjects. There was a significant negative correlation between enzyme activity before treatment and the increase in enzyme activity following treatment (rs = -0.555, P less than 0.01, n = 21). These results indicate that low level of enzyme activity may be insufficiently improved by the treatment of diabetes, and the risk for the development of atherosclerosis as viewed from the enzyme activity may persist even after the treatment in NIDDM.

Transformation of arylamines into direct-acting mutagens by reaction with nitrite

Arylamines including aniline (I), 1-naphthylamine (II), 2-naphthylamine (III), 2-aminofluorene (IV), 1-aminoanthracene (V) and 1-aminopyrene (VI) were treated with 4 equivalent amounts of nitrite at pH3 and 37 degrees C for 4 h. The reaction mixtures of I, IV, V and VI showed mutagenicity to Salmonella typhimurium TA98 and TA100 strains without metabolic activation. The numbers of His+ revertant colonies to TA98 strain were 110/0.05 mumole I, 970/0.055 mumole IV, 620/0.10 mumole V and 870/0.02 mumole VI. These arylamines were converted into mutagens with diazoquinone, diazonium and nitro functions depending on their structures. The mutagen from I was p-diazoquinone (I2). The mutagen from IV was highly unstable fluorene-2-diazonium salt (IV1). The mutagens from V were N3O3-introduced anthracene (V1-1) and 1-nitroanthracene (V2), and those from VI were unidentified nitro-introduced compound (VI1) and 1-nitropyrene (VI2).

Desensitization of the epidermal adenylate cyclase system: agonists and phorbol esters desensitize by independent mechanisms

Exposure of pig epidermis to adenylate cyclase stimulators results in receptor-specific desensitization. We investigated the nature of the agonist-induced desensitization, which was compared with the phorbol ester-induced, receptor-nonspecific desensitization. Both phorbol ester-induced desensitization and the agonist-induced desensitization were accompanied by an increase in forskolin- and cholera toxin-induced cyclic AMP accumulations. The magnitude of the increase in the agonist-induced desensitization was parallel to the degree of the initial cyclic AMP accumulation; histamine and adenosine, which increase more cyclic AMP than epinephrine, resulted in a more marked increase in forskolin- and cholera toxin-induced cyclic AMP accumulations. Similarly, epidermis desensitized to multiple receptors revealed more marked forskolin- and cholera toxin-induced cyclic AMP accumulations than epidermis desensitized to a single receptor. In contrast to the phorbol ester-induced desensitization, agonist-induced desensitization was not affected by the protein kinase C inhibitors H-7 and staurosporin. Further, agonist-induced desensitization was still inducible in phorbol ester-desensitized epidermis and vice versa. In contrast to the agonist-induced desensitization, which is accompanied by the preceding adenylate cyclase stimulation, no evidence for the stimulation of the adenylate cyclase during phorbol ester treatment was obtained. Neither agonist-induced desensitization nor phorbol ester-induced desensitization affected the content of inhibitory guanine nucleotide binding protein of the epidermis, which was monitored by the pertussis toxin (IAP)-catalyzed ADP ribosylation reaction. Our results indicate that agonist-induced desensitization and the phorbol ester-induced desensitization are independent of each other. Although both processes are characterized by increased forskolin- and toxin-induced cyclic AMP accumulations, the former is accompanied by initial cyclic AMP accumulation; the latter is not.

Inhibitory guanine nucleotide binding protein in pig epidermis: regulation of epidermal adenylate cyclase

Islet-activating protein (IAP), one of the pertussis toxins, serving [alpha-32P]nicotinamide adenine dinucleotide (NAD) as a substrate for ADP ribosylation, radiolabelled a specific pig epidermal membrane protein. The IAP-specific substrate was detectable by sodium dodecyl sulphate-polyacrylamide gel electrophoresis as a single band corresponding to a molecular weight of 40 kDa. The ADP ribosylation catalysed by IAP was inhibited by the addition of Mg2+ to the reaction mixture. IAP is known to work on intact cell systems resulting in the ADP ribosylation using intracellular NAD as the ADP ribose donor. Following IAP pretreatment of intact pig epidermis, the epidermal receptor adenylate cyclase responses were markedly increased; all the stimulatory receptor adenylate cyclase responses (beta-adrenergic, prostaglandin E, adenosine and histamine responses) were significantly increased. Cholera toxin-induced cyclic AMP accumulation was also significantly increased. Forskolin-induced cyclic AMP accumulation was slightly increased after IAP pretreatment, but this was not statistically significant. The IAP-dependent ADP ribosylation of the epidermal 40 kDa membrane protein, which was prepared from the IAP pretreated epidermis, was significantly decreased. It is known that the tumour promoter, phorbol 12-myristate,13-acetate (PMA), decreases stimulatory receptor adenylate cyclase responses of the epidermis. Following the PMA pretreatment, IAP-dependent ADP ribosylation of the epidermal membrane protein was unaffected. Furthermore, following the PMA pretreatment, the IAP-induced increase in the epidermal receptor adenylate cyclase responses still remained. Our results indicate that pig epidermis contains 40 kDa membrane substrate for IAP-dependent ADP ribosylation, which has an inhibitory tonus on the epidermal adenylate cyclase until its ADP ribosylation by IAP.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenylate cyclase system in fetal rat keratinizing epidermal cells (FRSK cells) and SV40-transformed human keratinocytes

The adenylate cyclase system of FRSK cells, a cultured cell line of fetal rat epidermal keratinocytes, and SV40-transformed human keratinocytes was investigated. Stimulators of the human epidermal adenylate cyclase, epinephrine, adenosine, and prostaglandin E2 increased cyclic AMP levels of these cells. There were marked differences in the stimulatory effects; while epinephrine revealed a much stronger effect than the other stimulators in FRSK cells, epinephrine and prostaglandin E2 revealed similarly marked effects in SV40-transformed cells. Histamine had little or only slight effect on the cyclic AMP levels of these cells. Cholera toxin and forskolin, which work on the stimulatory guanine nucleotide binding protein (Gs) and the catalytic component of adenylate cyclase, respectively, also increased cyclic AMP levels. Northern blot hybridization analysis revealed that both FRSK cells and SV40-transformed human keratinocytes express mRNAs for the beta 2-adrenergic receptor, as well as the stimulatory and inhibitory guanine nucleotide binding proteins (Gs and Gi, respectively). The presence of Gs as well as Gi were confirmed by cholera toxin-, and pertussis toxin (IAP)-induced ADP-ribosylation of membranous proteins of these cells. Our results indicate that both FRSK cells and SV40-transformed human keratinocytes express the fundamental components of the adenylate cyclase system. These cell lines might be useful tools for the analysis of the adenylate cyclase system in epidermal keratinocytes.

Acid cholesteryl ester hydrolase activity of mononuclear leukocyte in type 2 (non-insulin-dependent) diabetic patients

Acid cholesteryl ester hydrolase activity of mononuclear leukocytes was measured in 52 Type 2 (non-insulin-dependent) diabetic patients. Enzyme activity was significantly lower in the diabetic patients than in 14 age-matched control subjects (0.89 +/- 0.08 (mean +/- S.E.) vs. 2.20 +/- 0.17 nmol/mg protein/hr, p less than 0.01). In diabetic patients undergoing diet treatment only, the enzyme activity was significantly lower in poorly controlled patients than in well controlled patients (0.43 +/- 0.03 vs. 1.15 +/- 0.24 nmol/mg protein/hr, p less than 0.01). In the diabetic patients, there was a significant negative correlation between the enzyme activity and serum total cholesterol or low density lipoprotein cholesterol level (r = -0.361, p less than 0.01, n = 52 or r = -0.630, p less than 0.01, n = 28). These results suggest that a low level of acid cholesteryl ester hydrolase activity in mononuclear leukocyte might play an important role in the progression of atherosclerosis in Type 2 diabetes.

[A case of traumatic hernia of right diaphragma]

A patient with traumatic diaphragmatic hernia at right side was treated surgically. He was 63-year-old male. His illness was caused by a traffic accident one year ago. The major symptoms due to the injury were short breathness and pain at right lateral chest wall. One year later he complained of the nausea and abdominal discomfort. At the right thoracotomy, the herniation of liver and colon through the ruptured diaphragma was found. After the return of herniated organ into the abdominal space, ruptured diaphragma was closed directly.

[Arterial infusion cancer chemotherapy in liver tumor using implantable reservoir]

Four primary liver tumors and 19 secondary ones (8 gastric, 8 colorectal, 2 esophageal and 1 gall bladder cancer) were treated by intra-arterial infusion chemotherapy intermittently using implantable reservoir. Drugs used in this series were 5-Fluorouracil, Mitomycin C, Adriamycin, and Cis-platinum. They were infused every 2 weeks for outpatients. The antitumor efficacy was evaluated in terms of tumor regression measured by CT scan. The toxicity was slight and temporary. The total response rate was 23.1%, 50% survival period was 7 months, and 1-year survival rate was 24.2%. The response rate was 33.3%, and the 50% survival period was 7 months for 8 gastric cancer patients with liver metastasis. The result was not good, and we must improve the criteria of indication and devise a regimen. But the implantable drug delivery system has made it possible to lengthen the time that patients may stay home and assure good quality of life because of the freedom of movement, normal physical appearance, protection from infection, and reduction of mental burden, due to subcutaneous placement.

[Results of surgical treatment in patients aged 80 years and over]

Surgical treatments were performed in 31 patients over 80-year-old with lung cancer. Men were 25 and women were 6, the eldest patient was 92-year-old male. Pneumonectomy was carried out in 3, lobectomy in 19, carinal resection in 1, Segmentectomy in 4, and partial resection of lung in 2. Histologies of resected specimen in 31 included 11 epidermoid carcinoma, 15 adenocarcinoma and 5 other cell types. There was no patients died within 30 days postoperatively. The cumulative 5 year-survival rate was 53.9%.

Advanced intravascular bronchioloalveolar tumour and review of reports in Japan

Intravascular bronchioloalveolar tumour (IVBAT) is a rare pulmonary neoplasm. We report the clinical and pathologic findings of two patients who demonstrated unusual clinical features. Both of them were young males who showed a large mass or consolidated shadow and small nodules with pleurisy on chest X-rays due to the invasive growth of tumours. In the first case the presumptive diagnosis of lung carcinoma was made from the discovery of atypical cells in pleural fluid. In the second case pleural mesothelioma was suspected. However, the histological diagnoses of these cases, including the immuno-histological and ultrastructural data, were reported and clinical features of IVBAT described previously in Japan were summarized.

Results of resection for bronchogenic carcinoma in patients over the age of 80

Thirty three patients aged over 80 years underwent resection for bronchogenic carcinoma. The operations performed were: lobectomy (21), segmentectomy (4), wedge resection (2), pneumonectomy (3), carinal resection (1). In two patients no resection was feasible. Three patients died within two months of surgery. The cumulative five year survival rate was 55%, 79% for patients with stage I carcinoma and 31% for stage III. It is considered that resection has an acceptable outcome in patients over 80 years.

Rec-assay of human bile for mutagenicity and co-mutagenicity

Spore rec-assay of human bile was conducted by the Bacillus subtilis test system to examine possible mutagenicity and co-mutagenicity. Of 26 samples examined, 8 (30.8%) showed mutagenic activity and 23 (88.5%) enhanced the mutagenic activity of mitomycin C.

Intrathoracic tumors arising from the vagus nerve. Review of resected tumors in Japan

Nineteen surgically treated intrathoracic vagus nerve tumors (16 neurilemmomas, 3 neurofibromas), including three treated by the authors, were reviewed. Tumor resection with vagus nerve amputation was performed in 14 and intracapsular excision without nerve amputation in 3 of the 17 adequately recorded cases. The location of vagus nerve tumor was the left upper mediastinum in 11 patients, almost all of whom were hoarse postoperatively due to sacrifice of the recurrent laryngeal nerve.

Characteristic radiographic features of pulmonary carcinoma associated with large bulla

Primary lung cancer closely associated with a large bulla was investigated in an attempt to elucidate radiographic features of the tumor. On the basis of findings in 7 of our patients plus data on another 25 patients in the Japanese literature, we propose three major patterns of neoplasm development: nodular opacity within or adjacent to the bulla, partial or diffuse thickening of the bulla wall, and secondary signs of the bulla (changed diameter, fluid retention, and pneumothorax). As the incidence of occurrence of a pulmonary carcinoma in association with bullous disease is high, these radiographic findings will aid in early detection of a malignant lesion.

Resection of metastatic lung tumor: the evaluation of histologic appearance in the lung

The analysis of the data resulting from 58 operations for metastatic lung tumors is presented. The surgical procedures performed were unilateral lung tumor resection in 27 cases and bilateral lung tumor resection in 13 cases. The total cumulative five year survival rate was 41 per cent. The resected tumors were divided into two types according to the histologic appearance of the tumor margin: infiltrative and non-infiltrative (pseudo-capsulated). The cumulative five year survival rates were 14.7 per cent and 53.2 per cent, respectively. Lymph node metastasis was found in four patients with the infiltrative type of metastatic tumor.

Monoclonal antibodies against gingival components

The aim of this study was to produce and characterize monoclonal antibodies against human gingival epithelial cells and gingival fibroblasts. By using these whole cells as immunogens, we were able to generate a large number of monoclonal antibodies reacting with tissue antigens, in particular antibodies that reacted with desmosomes (MoAbs 7 and 8) and basement membrane (MoAb FB-1) antigens. MoAbs 7 and 8 produced from epithelial cells stained cell membranes of epithelium and desmosomes, respectively, as shown by light and immunoelectron microscopy. The epitopes to which MoAbs 7 and 8 were reactive were stable against various treatments; only periodate oxidation abolished the tissue reactions with MoAb 8. Extraction of gingiva with SDS or NP-40, SDS-PAGE analysis, and Western blotting showed that the MoAb 8 identified an antigen with a molecular weight of 100,000 daltons. MoAb FB-1 produced from fibroblasts immunolabeled the basement membranes. The FB-1 antigen was clearly different from any of the known ubiquitous basement membrane components, such as type IV collagen, laminin, and fibronectin. Examination of the distribution and localization of the antigen showed that it was present in the basement membrane beneath stratified squamous epithelium. FB-1 did not react with any of types I-VI collagens in ELISA, but immunoelectron microscopy showed that the antigen reacting with FB-1 was present in the lamina fibroreticularis of the basement membrane and was comprised of collagen-like fibers. These results suggest the possible existence of a new collagen other than types I-VI in the basement membrane beneath stratified squamous epithelium.

Effects of UVB irradiation on epidermal adenylate cyclase responses in vitro: its relation to sunburn cell formation

UVB irradiation augmented the beta-adrenergic adenylate cyclase response of pig skin epidermis in vitro. The effect was observed 2-4 h following the irradiation and lasted at least for 48 h. There was no significant difference in cyclic AMP phosphodiesterase activity between control and UVB-irradiated epidermis at lower irradiation dose (150 mJ/cm2), which is the dose of the most marked beta-adrenergic augmentation effect. The augmentation effect was specific to the beta-adrenergic system; adenosine and histamine adenylate cyclase responses were unchanged or decreased depending on the irradiation dose. Histologically, marked sunburn-cell formation was observed following the UVB irradiation. It has been suggested that oxygen intermediates generated by ultraviolet radiation participate in sunburn-cell formation. The addition of superoxide dismutase (SOD) in the incubation medium significantly inhibited sunburn-cell formation. On the other hand, the beta-adrenergic augmentation effect was not affected by the addition of SOD. Other scavengers of oxygen intermediates (catalase, catalase + SOD, xanthine, or mannitol) did not inhibit the UVB-induced beta-adrenergic augmentation effect. Further, superoxide-anion generating systems (hypoxanthine-xanthine oxidase system and acetaldehyde-xanthine oxidase system) revealed no stimulatory effect on the beta-adrenergic response of epidermis. These results indicate that (a) the UVB-induced beta-adrenergic augmentation effect is inherent to skin and does not depend on systemic factors such as inflammatory infiltrates following UVB irradiation; (b) in contrast to sunburn-cell formation, induction of the beta-adrenergic adenylate cyclase response is not directly associated with oxygen intermediates generated by UVB irradiation.

7-[3-(4-[2,3-Dimethylphenyl]piperazinyl)propoxy]-2(1H)-quinolinone (OPC-4392), a presynaptic dopamine autoreceptor agonist and postsynaptic D2 receptor antagonist

7-[3-(4-[2,3-dimethylphenyl]piperazinyl)propoxy]-2(1H)-quinolinone (OPC-4392), was synthesized in our laboratories and compared with apomorphine, 3-(3-hydroxyphenyl)-N-n-propylpiperidine (3-PPP) and dopamine antagonists in a series of tests designed to characterize dopamine receptor activation and inhibition. The assertion that OPC-4392 acts as an agonist at presynaptic dopamine autoreceptors is supported by the following behavioral and biochemical observations: OPC-4392, 3-PPP and apomorphine inhibited the reserpine-induced increase in DOPA accumulation in the forebrain of mice and in the frontal cortex, limbic forebrain and striatum of rats. In addition, the gamma-butyrolactone (GBL)-induced increase in DOPA accumulation in the mouse forebrain was also inhibited by OPC-4392, 3-PPP and apomorphine. Haloperidol antagonized the inhibitory effect of OPC-4392 in both instances. The inhibitory effect of OPC-4392 on GBL-induced DOPA accumulation lasted for at least 8 hours after oral administration to mice, while that of 3-PPP and apomorphine disappeared in 4 hours after subcutaneous injection. OPC-4392 failed to increase spontaneous motor activity in reserpinized mice, enhance spontaneous ipsilateral rotation in rats with unilateral striatal kainic acid (KA) lesions, induce contralateral rotation in rats with unilateral striatal 6-hydroxydopamine (6-OHDA) lesions and inhibit 14C-acetylcholine (Ach) release stimulated by 20 mM KCl in rat striatal slices. In addition, OPC-4392 appears to block postsynaptic D2 receptors since OPC-4392, as well as dopamine antagonists, was able to inhibit stereotyped behavior and climbing behavior induced by apomorphine in mice, displace the 3H-spiroperidol binding to rat synaptosomal membranes in vitro and reverse the inhibitory effect of apomorphine on Ach release in rat striatal slices. These results suggest that OPC-4392 acts as a dopamine agonist at presynaptic autoreceptors related to dopamine synthesis and acts as dopamine antagonist at postsynaptic D2 receptors.