Potentiating effect of hydrogen peroxide on the serotonin-induced vasocontraction in human umbilical artery

BACKGROUND

Our objective was to investigate the role of hydrogen peroxide in the vasocontraction induced in the human umbilical artery by serotonin.

METHODS

Umbilical arteries collected from healthy women at term were cut helically and suspended in an organ bath to record isometric mechanical activity. In Study I, we measured the concentration-contraction response to serotonin with or without pretreatment with hydrogen peroxide (0.01-10 microM). In Study 2, vessels were pre-incubated with L-arginine (0.1-10mM), or with hydrogen peroxide (10 mM) and L-arginine (1 mM), then serotonin was added cumulatively. In Study 3, vessels were suspended in a calcium-free solution containing potassium chloride 20 mM, and a cumulative concentration-response curve to calcium chloride (10(-5)-10(-3) M) was constructed for vessels pretreated with hydrogen peroxide (10 microM). In Study 4, vessels were pre-treated with M1, an inhibitor of 5-HT2 serotoninergic receptors, and hydrogen peroxide (10 microM), and then prostaglandin F2 alpha (9.0 x 10(-7) M). Finally, we measured the 5-HT1 receptor-mediated relaxation induced by serotonin.

RESULTS

Hydrogen peroxide (1 or 10 microM) significantly potentiated the contractile response to serotonin (p < 0.04, p < 0.005). L-arginine (1 or 10 mM) significantly reduced the contractile response to serotonin (p < 0.02, p < 0.0002). Pretreatment with L-arginine significantly suppressed the potentiating effect of hydrogen peroxide on the serotonin-induced contraction. The sensitivity of the arteries to calcium chloride in the presence of hydrogen peroxide did not differ from that in the control group. Pretreatment with hydrogen peroxide significantly reduced the 5-HT1 serotoninergic receptor-mediated relaxation at higher concentrations of serotonin (1.23 x 10(-4) M, 2.47 x 10(-4) M, 2.47 x 10(-4) M).

CONCLUSION

Hydrogen peroxide potentiated the umbilical artery contraction induced by serotonin. This action may be mediated by suppression of endogenous nitric oxide activity.

Identification of cyclic cystathionine sulfoxide and N-acetylcyclic cystathionine in the urine of a patient with cystathioninuria using liquid chromatography-mass spectrometry with an atmospheric pressure chemical ionization interface system

Perhydro-1,4-thiazepine-4,5-dicarboxylic acid sulfoxide (cyclic cystathionine sulfoxide [cyclic cystaSO]) and N-acetylperhydro-1,4-thiazepine-3,5-dicarboxylic acid (NAc-cyclic cysta) have been identified in the urine of a patient with cystathioninuria as new metabolites of cystathionine for the first time using liquid chromatography-mass spectrometry with an atmospheric pressure chemical ionization interface system (LC/APCI-MS). The concentrations of cyclic cystaSO and NAc-cyclic cysta in the urine of a patient with cystathioninuria have also been determined for the first time using this method: 18.24 +/- 0.79 and 25.23 +/- 0.83 mg/g creatinine, respectively.

Prenatal monitoring in a family at high risk for ornithine transcarbamylase (OTC) deficiency: a new mutation of an A-to-C transversion in position +4 of intron 1 of the OTC gene that is likely to abolish enzyme activity

DNA analysis of a male propositus with ornithine transcarbamylase (OTC) deficiency documented an A-to-C substitution in position +4 of intron 1. No other abnormalities were observed in the OTC gene, or at 563 bp upstream of the 5' site, which included a promoter region, or at 383 bp downstream of the termination codon, which included a polyadenylation signal sequence. This mutation produces an RsaI site in the sequence, which was used for prenatal monitoring in the fourth and fifth pregnancies. DNA from amniotic cells in the former case were positive for RsaI digestion and the SRY gene (sex determinant region Y), indicating hemizygosity for the mutant allele. OTC activity was not measurable, and mRNA of the OTC gene was not detected by Northern blotting in the affected fetal liver. RT-PCR (reverse transcription-PCR) demonstrated only the wild-type allele. Thus, the mutation interferes with RNA processing, and an extremely low amount of normally spliced mRNA for the OTC gene seems to have caused the disease in our patient. The fetus of the fifth pregnancy was a normal male, as confirmed postnatally.

Effects of continuous medroxyprogesterone acetate on lipoprotein metabolism in postmenopausal women receiving estrogen

OBJECTIVE

To investigate the effects of medroxyprogesterone acetate (MPA) on the beneficial effects of estrogen therapy on lipid metabolism in postmenopausal women.

METHODS

Postmenopausal women were administered either conjugated equine estrogen (CEE) 0.625 mg daily for 3 months (Group 1) or CEE 0.625 mg in conjunction with MPA 2.5 mg (Group 2) or MPA 5.0 mg (Group 3) daily for 3 months. Plasma levels of cholesterol, triglyceride, lipoprotein lipids, apolipoproteins, sex steroid hormones and lecithin cholesterol acyltransferase activity (LCAT) were determined. Lipoprotein lipase (LPL) and hepatic triglyceride lipase (H-TGL) activities were measured in postheparin plasma. Changes in the lipid concentrations and enzymatic activities were evaluated in each group.

RESULTS

Total, low-density lipoprotein (LDL) cholesterol, apolipoprotein B concentrations and LCAT activity were all significantly reduced by treatment in the three groups. The levels of high-density lipoprotein (HDL), HDL2, and HDL3 cholesterol as well as the levels of apolipoprotein AI and AII were significantly elevated in groups 1 and 2. The mean decrease in these parameters was related to the dose of MPA. Levels of triglyceride in the HDL and HDL2 were significantly increased in group 1. The levels of triglyceride in plasma, very low density lipoprotein (VLDL), LDL, HDL3 and VLDL cholesterol and LPL activity were unaffected. H-TGL activity was significantly inhibited only in groups 1 and 2. MPA produced a dose-dependent increase in H-TGL activity. A significant negative correlation was observed between the HDL cholesterol concentration and H-TGL activity (r = 0.58 P < 0.001).

CONCLUSIONS

The administration of MPA 2.5 mg and 5.0 mg did not adversely affect the changes in VLDL-LDL metabolism produced by estrogen. However, MPA has dose-dependent negative effects on HDL metabolism by increasing H-TGL activity and the 5.0 mg MPA interferes with the favorable effects on lipids of estrogen in postmenopausal women.

Effect of cystathionine and cystathionine metabolites on the phosphorylation of tyrosine residues in human neutrophils

The effect of cystathionine and cystathionine metabolites found in the urine of patients with cystathioninuria on the phosphorylation of tyrosine residues was studied with human peripheral blood polymorphonuclear leukocytes. Among the cystathionine metabolites, cystathionine ketimine markedly increased phosphorylation of a 45 kDa protein with time and the phosphorylation depended on the concentration of cystathionine ketimine, while cystathionine and the reduced form of cystathionine ketimine (cyclothionine) did not increase the phosphorylation of the 45 kDa protein. The phosphorylation of the 45 kDa protein induced by cystathionine ketimine was inhibited by genistein and herbimycin A, inhibitors of tyrosine kinase, but was not inhibited by 1-(5-isoquinolinesulfonyl)-2-methylpiperazine and staurosporine, inhibitors of protein kinase C.

Identification and mapping of functional domains on human T-cell lymphotropic virus type 1 envelope proteins by using synthetic peptides

To identify the regions that are important in human T-cell leukemia virus type 1 (HTLV-1) envelope function, we synthesized 23 kinds of peptides covering the envelope proteins and examined the inhibitory effect of each peptide on syncytium formation induced by HTLV-1-bearing cells. Of the 23 synthetic peptides, 2, corresponding to amino acids 197 to 216 on gp46 and 400 to 429 on gp21, inhibited syncytium formation induced by HTLV-1-bearing cells but did not affect syncytium formation induced by human immunodeficiency virus type 1-producing cells. The peptide concentrations giving 50% inhibition of syncytium formation for gp46 197 to 216 and gp21 400 to 429 were 14.9 and 6.0 microM, respectively. A syncytium formation assay with overlapping synthetic peptides containing amino acids 175 to 236 and 391 to 448 of the envelope proteins showed that syncytium formation was inhibited by peptides that contained the amino acid sequences 197 to 205 (Asp-His-Ile-Leu-Glu-Pro-Ser-Ile-Pro) and 397 to 406 (Gln-Glu-Gln-Cys-Arg-Phe- Pro-Asn-Ile-Thr). These observations suggest that the two regions corresponding to amino acids 197 to 216 and 400 to 429 are involved] in HTLV-1 envelope function.

Relaxant effect of nitric oxide and prostacyclin on serotonin-induced vasocontraction of human umbilical artery

BACKGROUND

We investigated the effect of nitric oxide and prostacyclin, which are endothelium-derived vasodilators, on serotonin (5-HT)-induced vasocontraction, and 5-HT1-serotoninergic receptor mediated relaxation in the human umbilical artery.

METHODS

Serotonin-stimulated vasocontraction was measured in umbilical artery segments treated with and without 1) L-arginine (10(-4) M approximately 10(-2) M), a precursor of nitric oxide synthesis; 2) methylene blue (10(-5) M) and L-NG-monomethyl arginine (LNMA, 2 X 1O(-4) M), which are specific inhibitors of nitric oxide action and nitric oxide synthesis, respectively; and 3) tranylcypromine (2 X 10(-6) M, 2 X 10(-5) M), an inhibitor of prostacyclin synthesis. 4) Vessels were pretreated with M1, an inhibitor of 5-HT2 serotoninergic receptors, and then prostaglandin F2 alpha (9.O X 1O(-7) M). Finally, we measured the 5-HT1, receptor-mediated relaxation induced by 5-HT.

RESULTS

Treatment with L-arginine significantly inhibits 5-HT-induced contraction in a dose-dependent manner. Treatment with methylene blue and LNMA significantly potentiated 5-HT-induced contraction. Tranylcypromine caused no significant changes in 5-HT-induced vasocontraction. 5-HT1 serotoninetic receptor-mediated relaxation was found at higher concentrations of 5-HT (greater than 4.94 X 10(-5) M).

CONCLUSIONS

Our results suggest that nitric oxide may exert a strong relaxant effect on 5-HT-induced vasocontraction compared with prostacyclin in human umbilical artery.

Increased antioxidant enzyme activity in amyloid beta protein-resistant cells

Clones of the rat pheochromocytoma cell line PC12 were selected for their resistance to amyloid beta protein (A beta). These A beta-resistant cells also survive higher concentrations of exogenously applied peroxides than the parent cells. A beta triggers intracellular H2O2 accumulation in the parent PC12 cells but not in the A beta-resistant cells. The absence of H2O2 accumulation in A beta-resistant cells is not attributable to differences in A beta binding to the cell surface. However, the mRNA and protein levels of catalase and glutathione peroxidase, as well as the corresponding enzyme activities, are highly elevated in A beta-resistant clones. These activities correlate well with the increased resistance of cells to A beta or peroxides. Finally, cells transfected with catalase and glutathione peroxidase are also more resistant to A beta toxicity. These results indicate that increased antioxidant enzyme activities in A beta-resistant cells account for at least part of their resistance to A beta and substantiate further the role of H2O2 in A beta toxicity.

Effect of cystathionine ketimine on the stimulus coupled responses of neutrophils and their modulation by various protein kinase inhibitors

Human peripheral blood polymorphonuclear leukocytes were perincubated with cystathionine and cystathionine metabolites found in the urine of the patients with cystathioninuria. Among the cystathionine metabolites, cystathionine ketimine significantly enhanced the N-formyl-methionyl-leucyl-phenylalanine-induced superoxide generation, but cystathionine and cyclothionine did not enhance the superoxide generation. Cystathionine ketimine also enhanced superoxide generation induced by opsonized zymosan but not those induced by arachidonic acid and phorbol myristate acetate. Superoxide generation induced by cystathionine ketimine was inhibited by genistein, an inhibitor of tyrosine kinase, and was enhanced by 1-(5-isoquinoline-sulfonyl)-2-methyl-piperazine, an inhibitor of protein kinase C.

[The influence of pregnancy and delivery on the climacteric symptoms]

This study was undertaken to investigate the influence of past pregnancy and delivery on the perimenopausal status in 144 women (48-52 years of age). Individual interviews to ascertain the personal profile, medical history, events at pregnancy, delivery and puerperium, and the kind and severity of climacteric symptoms were held. The subjects were divided into two groups by means of a simplified menopausal index (SMI): group A had climacteric symptoms (SMI > 50) and those in group B had mild symptoms (SMI < or = 50). The analysis of the principal components, and the correlation among the variables revealed that three factors--the impression and events at past pregnancies and deliveries, reproductive functions, and the psycho-character properties--had a significant influence on the status at the perimenopause, but the social-environmental factors appeared to have no significant influence on the severity of climacteric symptoms.

Cloning and sequence analysis of a full-length cDNA of rat adrenodoxin

A cDNA clone which covers the entire coding region for the precursor of adrenodoxin was isolated from a rat adrenal cDNA library. This precursor consists of amino-terminal 64 residues of extrapeptide for transport into mitochondria and the following 124 residues of mature peptide region. The amino acid sequence of rat mature adrenodoxin showed 85-98% homology with mouse, human, chicken, porcine, bovine and sheep counterparts, whereas that of the extrapeptide showed significantly lower values.

Modulation of endothelium-dependent flow-mediated dilatation of the brachial artery by sex and menstrual cycle

BACKGROUND

Estrogen has been reported to augment endothelium-dependent vasodilatation. The role of endogenous ovarian hormones in modulating endothelium-dependent vasodilatation, however, remains to be determined. The purpose of the present study was to investigate the effects of sex and menstrual cycle on endothelium-dependent flow-mediated vasodilatation.

METHODS AND RESULTS

Seventeen female volunteers 25.1 +/- 0.8 years old and 17 age-matched male volunteers were examined. We measured brachial artery diameters noninvasively using a 7.5-MHz ultrasound machine at rest, during reactive hyperemia, and after sublingual nitroglycerin administration. All female subjects were studied three times each, in three different phases of one menstrual cycle (M, menstrual phase; F, follicular phase; and L, luteal phase). Flow-mediated diameter (D) increase (%FMD; delta D/D x 100) in M, when serum estradiol level was low (121.9 +/- 12.5 pmol/L), was 11.22 +/- 0.58%, and the value was comparable to that in male subjects (10.60 +/- 0.75%). %FMD increased in F (18.20 +/- 0.81%, P < .01 versus M) and L (17.53 +/- 0.74%, P < .01 versus M), when serum estradiol level was high (F, 632.0 +/- 74.5 and L, 533.8 +/- 33.4 pmol/L, P < .01 versus M). Endothelium-independent vasodilatation by nitroglycerin increased in both F and L. However, the increment was smaller than that of %FMD.

CONCLUSIONS

Endothelium-dependent vasodilatation varies during the menstrual cycle. The endogenous estradiol may be involved in this menstrual cycle-related vasodilatation.

Ephedrine-induced increases in arterial blood pressure accelerate regression of epidural block

We investigated the hypothesis that ephedrine-induced increases in blood pressure accelerate the regression of epidural block. In patients undergoing minor gynecologic surgery, we performed lumbar epidural blockade using 2% lidocaine containing 1:200,000 epinephrine to which was added 0.1 mg of fentanyl. Eighty minutes after the epidural injection, we started an ephedrine infusion to increase the systolic blood pressure by 20% in 10 min and maintained the value for the following 20 min. Then we compared the proximal extent of sensory analgesia at 80 min with that at 140 min. Ephedrine significantly (P = 0.001) hastened the regression of sensory analgesia. We conclude that an ephedrine-induced blood pressure increase accelerates regression of epidural blockade.

A new computer network system for communicating perinatal decision support information via a telephone line

OBJECTIVE

For fetal monitoring and assessment of high risk mother and fetus at regional hospitals, we developed a new computer network system.

METHODS

The system incorporates a notebook-type personal computer (PC-9801nv) at regional hospital for communication in with 3 servers (IBM5580-YOC) connected via 2 Ethernet LANs to 2 host computers (IBM3080, IBM3174) and 5 workstations (IBM5521 V2b), and transmits the compressed data by telephone. When the data arrive, the doctor in perinatal center can immediately display and interpret the data on his workstation and give appropriate advice to the doctor at the regional hospital.

RESULTS

The rate of reliable data transmission was 100%. Each 1 hour recording session and characteristic perinatal information was transmitted in less than 2 minutes. Regional medical institutions can easily access the center, and thereby can receive both simplified automatic diagnosis by fetal cardiotocography and pregnancy-risk evaluation.

CONCLUSIONS

Because this system uses telephone circuits, it can be accessed from all regions of the country. Thus, our system is useful for perinatal management of high risk mother and fetus.

Identification of a transcriptional regulatory factor for human aromatase cytochrome P450 gene expression as nuclear factor interleukin-6 (NF-IL6), a member of the CCAAT/enhancer-binding protein family

Human aromatase cytochrome P450 catalyzes the ultimate reaction in the estrogen biosynthetic pathway by coupling with another enzyme, NADPH-cytochrome P450 reductase, in the endoplasmic reticulum. The expression of the gene encoding the enzyme (CYP19) is regulated, in part, by tissue-specific promoters through the use of alternative-splicing mechanisms. Recently, we have localized a transcriptional activating element at positions -2141 to -2115 relative to the major cap site of the gene, by transient expression analyses in human BeWo choriocarcinoma cells using the bacterial chloramphenicol acetytransferase reporter gene ligated with CYP19 promoter sequences which regulate expression in this tissue. Here, we report the isolation of a cDNA encoding a DNA-binding protein which binds specifically to the regulatory element. The deduced amino-acid sequence of the insert is identical to that corresponding to the DNA-binding domain and the dimerization domain of a transcription factor, nuclear factor interleukin-6 (NF-IL6), a member of the CCAAT/enhancer-binding protein (C/EBP) family. Studies using specific antibodies against members of the C/EBP family demonstrate that NF-IL6 is the major nuclear factor binding to the regulatory element in BeWo cells; nevertheless. C/EBP alpha also seems to be involved. Disruption of the NF-IL6-binding site within the regulatory element resulted in the disappearance of the transcriptional enhancing activity of the element, indicating that NF-IL6 is at least one of the nuclear factor(s) which enhances transcription through binding to the cis-acting element. These results indicate the intrinsic importance of NF-IL6 in the transcriptional regulation of CYP19 expression.

Additional evidence for blepharismin photoreceptor pigment mediating step-up photophobic response of unicellular organism, Blepharisma

In the ciliated protozoan, Blepharisma japonicum, the pink-colored pigment (blepharismin) contained in the pigment granules is believed to be the photoreceptor pigment responsible for the step-up photophobic response. When the cells partially bleached by extrusion of the pigment granules caused by cold shock were subsequently cultured under illuminated conditions, the pigment-less granules regenerated and the cells were further bleached (pigment content below 0.5%). The photosensitivity of such colorless cells disappeared completely. In contrast, the blepharismin pigment regenerated gradually when such colorless cells were transferred to darkness. The photosensitivity of the cells also recovered with regeneration of the pigment. We found that blepharismin pigment was not photobleached in the absence of O2. The step-up photophobic response was also completely repressed in the absence of O2. These results strongly confirm that blepharismin is a photoreceptor pigment mediating photobehavior of Blepharisma and that O2 is required for the early step in the phototransduction of the light-excited pigment.

Purification and characterization of a cam repressor (CamR) for the cytochrome P-450cam hydroxylase operon on the Pseudomonas putida CAM plasmid

The cytochrome P-450cam hydroxylase operon of Pseudomonas putida PpG1 (ATCC 17543) encodes proteins responsible for early steps of the degradation of D-camphor. Transcription of this operon is negatively controlled by the cam repressor (CamR), and the expression of camR is autoregulated. CamR was purified from Escherichia coli harboring an overproducing plasmid. The repressor forms a homodimer with a molecular mass of 40 kDa, as judged by sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis and gel filtration. CamR protected a specific DNA region from attack by DNase I. This region contains a palindromic operator of the cytochrome P-450cam hydroxylase operon and of the camR gene. Protection was inhibited by the addition of 60 microM D-camphor and also by certain camphor analogs and degradation products, including D-3-bromocamphor, adamantane, 2-adamantanone, 5-exo-hydroxycamphor, and 2,5-diketocamphane. These analogs and degradation products induced cytochrome P-450cam hydroxylase operon expression in vivo.

Lipoprotein metabolism in postmenopausal and oophorectomized women

OBJECTIVE

To investigate the mechanisms of accumulating cholesterol, and to analyze the metabolism of excess tissue cholesterol in women with low plasma levels of sex steroid hormones.

METHODS

We measured plasma concentrations of cholesterol, triglyceride, apolipoproteins, sex steroid hormones, and lecithin cholesterol acyltransferase activity in 20 premenopausal, ten postmenopausal, and ten bilaterally oophorectomized women. Lipoprotein lipase and hepatic triglyceride lipase activities were measured in postheparin plasma. We compared the three groups and evaluated a correlation between lipid metabolism and sex steroid hormone concentrations.

RESULTS

The mean plasma low-density lipoprotein (LDL) cholesterol level, lecithin cholesterol acyltransferase activity, and postheparin plasma lipoprotein lipase activity were higher in the postmenopausal and surgically menopausal groups. The mean plasma high-density lipoprotein (HDL) cholesterol concentration and postheparin plasma hepatic triglyceride lipase activity did not differ significantly among the three groups. The plasma LDL cholesterol level and postheparin plasma lipoprotein lipase activity showed a significantly negative correlation with plasma concentration of estrone (LDL: r = 0.64, P < .001; lipoprotein lipase: r = 0.54, P < .005) and estradiol (LDL: r = 0.65, P < .001; lipoprotein lipase: r = 0.47, P < .01), but not with that of testosterone. There was no significant relationship between postheparin plasma hepatic triglyceride lipase activity and plasma sex steroid hormones. Plasma lecithin cholesterol acyltransferase activity correlated significantly with plasma LDL cholesterol concentration, but not with levels of sex steroid hormones.

CONCLUSION

Because of low endogenous estrogens, enhanced postheparin plasma lipoprotein lipase activity may lead to an elevated plasma LDL cholesterol concentration in postmenopausal and bilaterally oophorectomized women. We demonstrated an accelerated cholesterol esterification in HDL cholesterol that may have been induced by LDL cholesterol accumulation, although the HDL cholesterol concentration remained unchanged.

Amplifying effect of endothelin-1 on serotonin-induced vasoconstriction of human umbilical artery

OBJECTIVE

The purpose of this study was to evaluate the role of endothelin-1 in serotonin-induced vasoconstriction in human umbilical artery.

STUDY DESIGN

Umbilical arteries collected from 41 normal subjects at term were cut helically and suspended in an organ bath for recording isometric mechanical activity. In study 1 we measured the concentration-contraction response to serotonin or endothelin-1 according to a cumulative concentration schedule. In study 2 vessels were preincubated with a subthreshold concentration of endothelin-1 (100, 250, or 500 pg/ml), and then serotonin was added cumulatively. In study 3 vessels were preincubated with H-7 (3 x 10(-6) mol/L), an inhibitor of protein kinase C, or with 12-tetradecanoylphorbol-13 acetate (10(-9) to 10(-7) mol/L), an activator of protein kinase C; then serotonin was added cumulatively. In study 4 vessels were suspended in a calcium-free solution containing 2 mmol/L ethylene glycol-bis(beta-aminoethyl ether) N,N,N',N'-tetraacetic acid and 60 mmol/L potassium chloride, and then a cumulative concentration-response curve to calcium chloride (10(-7) to 10(-3) mol/L) was constructed for vessels pretreated with endothelin-1, 500 pg/ml or 5 ng/ml.

RESULTS

The threshold concentrations of serotonin and endothelin-1 were 5 and 1 ng/ml, respectively. A subthreshold concentration of endothelin-1 (250 or 500 pg/ml) potentiated significantly the concentration response to serotonin (p < 0.084, p < 0.009, by analysis of variance). Pretreatment with H-7 significantly suppressed the amplifying effect of endothelin-1 on serotonin-induced contraction. Treatment with 12-tetradecanoylphorbol-13 acetate (10(-7) or 10(-8) mol/L) significantly potentiated the contractile response to serotonin (p < 0.0003, p < 0.015). The sensitivity of the arterial segments to calcium chloride in the presence of a subthreshold concentration of endothelin-1 did not differ from that in the control group.

CONCLUSION

Endothelin-1 at a subthreshold concentration amplified the smooth muscle contraction induced by serotonin. The mechanism of action may be mediated by activation of intracellular protein kinase C.

[Long-term study of patients with sequelae of pulmonary tuberculosis after pneumonectomy--obstructive impairment and its causes]

Changes in pulmonary function, chest X-ray films, and CT were retrospectively studied in patients with sequeae of pulmonary tuberculosis 30 years after pneumonectomy (PNX). Over more than 10 years, VC and FEV1% changed at a rate of 23.2 +/- 8.8 ml and 0.683 +/- 0.688% per year, respectively. In the patients studied 30 years after PNX (N = 30), VC was 900 +/- 210 ml, %VC 31.6 +/- 8.1%, and FEV1% was 67.2 +/- 6.8%. About half of these patients had mild airway obstruction. FEV1% was negatively related to the distance from the hilum to the diaphragm on the mid-clavicular line (on the chest films) divided by body height (r = -0.607). Therefore, we think that the airway obstruction may be due to overextension of the bronchi of middle and lower lobes. Emphysema was not found in 18 patients who had no sign of hyperinflation or herniation of the remaining lung to the PNX side on their CT, but it was found in one patient with these signs.

Amyloid peptides are toxic via a common oxidative mechanism

beta-Amyloid protein (A beta) is a member of a small group of proteins that accumulate as amyloid deposits in various tissues. It has recently been demonstrated that the toxicity of A beta toward some neural cells is caused by oxidative damage. Since all of the amyloid diseases are characterized by protein deposited in the antiparallel beta-sheet conformation, it was asked whether there is a common toxic mechanism. It is shown here that the protein components of other human amyloidoses, including amylin, calcitonin, and atrial natriuretic peptide, are all toxic to clonal and primary cells. The toxicity is mediated via a free radical pathway indistinguishable from that of A beta. Experiments with synthetic peptides suggest that it is the amphiphilic nature of the peptides generated by their beta structure rather than their beta structure per se that causes toxicity. These results tend to rule out the alternative that amyloid toxicity is exclusively mediated via specific cell surface receptors.

Purification and characterization of rat adrenodoxin

Adrenodoxin was purified from the rat adrenal gland. The A414/A280 value of the purified rat adrenodoxin was 0.90 and the oxidized spectrum showed absorption maxima at 320, 414 and 455 nm, similar to those of bovine adrenodoxin. On SDS-PAGE, the rat adrenodoxin showed a single band with a molecular mass of 11.2 kDa, while the apparent molecular mass by gel filtration through Sephadex G-75 equilibrated with 10 mM K-phosphate (pH 7.5) was 27 kDa. In the reconstituted system, Vmax of NADPH-cytochrome c reduction activity and the Km for the rat adrenodoxin were much the same as those for recombinant bovine adrenodoxin. In the case of cholesterol side-chain cleavage activity, however, these values of the rat adrenodoxin were about half of those of the bovine adrenodoxin. The CD spectrum of the rat adrenodoxin was similar to that of the bovine adrenodoxin but showed a significantly lower ellipticity value in the 195-205 nm region than that of the bovine adrenodoxin. The structural differences may possibly explain differences in the enzymic properties between rat and bovine adrenodoxins.

Enhanced nocturnal melatonin secretion in women with functional secondary amenorrhea: relationship to opioid system and endogenous estrogen levels

The purpose of this study was to evaluate the role of the opioid system and the estrogen environment in the nocturnal secretion of melatonin in women with secondary amenorrhea (SA). Nocturnal melatonin concentrations in patients with SA were significantly higher than in normal women (p < 0.01 vs. women with normal menstrual cycles). There were significant negative correlations between cumulative melatonin levels (between 8 p.m. and 8 a.m.) and serum estradiol-17 beta (r = -0.561, p < 0.01) and between peak serum melatonin values and serum estradiol-17 beta concentrations (r = -0.608, p < 0.01) in SA. Intravenous administration of a conjugated estrogen (Premarin 20 mg) significantly suppressed nocturnal melatonin secretion (p < 0.05), but a continuous intravenous infusion of naloxone (1.6 mg/h from 8 p.m. to 6 a.m.), an opiate antagonist, did not affect nocturnal melatonin secretion in SA. Our findings suggest that elevated nocturnal melatonin secretion may be related to low estrogen levels, but that it is not mediated by the opioid system.

High detection rate of breast cancer by mass screening using mammography in Japan

A trial of mass screening for breast cancer using both mammography and physical examination (independently) was carried out in women over 50 years of age in Tokushima Prefecture. Breast cancer was detected in eight of a total of 950 examinees by mammography alone, and no cases of breast cancer were detected by physical examination. The detection rate of breast cancer was 0.84%, which is very much higher than that obtained by conventional mass screening using physical examination alone. The detection rate increased especially in the sixth and seventh decades of life. All eight detected breast cancers were in the early stage. Based on these results, it is recommended to employ mammography in breast cancer screening for asymptomatic women aged over 50 years.