Bioactivity of neolignans from fructus Schizandrae

Fructus Schizandrae sinensis Baill, a traditional Chinese medicine, used as tonic and sedative, has been shown at the beginning of 70's to lower the elevated serum glutamic-pyruvic transaminase (SGPT) levels of patients suffering from chronic viral hepatitis. During past 20 years, a series of neolignans have been isolated and identified as effective principles. Pharmacological studies revealed that they increased liver protein and glycogen synthesis, antagonized liver injuries from CCl4 and thioacetamide. The mechanism of SGPT lowering was considered as a hepato-protective and membrane stabilize action, although inhibition of the activity of liver GPT may also be existed. It was found that some principles of Schizandrae have an inducing effect on hepatic microsomal drug-metabolizing enzyme system P-450, thus explained their anti-toxic, anti-carcinogenic and anti-mutagenic effects. A synthetic derivative compound of Schisandrin called DDB has most of the above mentioned actions now used widely in China as a hepato-protective drug with high effectiveness in normalizing liver functions and very low side effects. From natural Schisandrin to synthesized DDB, pointed out a successful way in the development of new drugs from natural products.

Secretion of plasminogen activator inhibitor by normal rat pleural leukocytes in culture

The normal balance between coagulation and fibrinolysis in the pleural cavity is poorly understood despite the critical role of the pleura in the movement of the lungs. To determine the fibrinolytic activity and the interaction between plasminogen activators and their inhibitors in the normal pleural space, we tested normal rat pleural leukocytes, principally macrophages and mast cells, and their supernatants, for activity in an [125I]fibrin degradation assay. It was found that pleural leukocytes did not release plasminogen activator, but the leukocytes and their supernatants inhibited the plasminogen-dependent fibrinolysis caused by both alveolar leukocytes and mesothelial cells. Further experiments demonstrated that pleural leukocytes produce a protein inhibitor primarily against urokinase-induced fibrinolysis in culture and that macrophages are the main source of the inhibitor. The lysate of mast cell-enriched population exhibited high plasminogen activator activity while no such activity could be determined in macrophage-enriched lysate. These data show that normal rat pleural leukocytes contain plasminogen activator inside the cells and synthesize a urokinase-type plasminogen activator inhibitor in culture that may be important in the fibrinolysis/coagulation balance in the pleural space.

Iron-mediated radical reactions upon reperfusion contribute to myocardial "stunning"

Recent evidence suggests that postischemic myocardial dysfunction ("stunning") is mediated by iron-catalyzed free radical reactions, but the exact time window during which the critical iron-mediated damage develops remains unknown. Furthermore, the evidence that iron promotes free radical reactions in vivo is indirect. Thus open-chest dogs undergoing a 15-min coronary occlusion and 4 h of reperfusion were given one of the following intracoronary infusions: desferrioxamine (DF) beginning 2 min before reperfusion (group I), DF beginning 1 min after reperfusion (group II), iron-loaded DF in dosage identical to group I (group III), or vehicle (controls, group IV). Recovery of contractile function was substantially greater in group I than in controls, whereas in groups II and III it was indistinguishable from controls. To determine whether the protection afforded by DF was due to inhibition of free radical reactions, myocardial production of free radicals was directly assessed by intracoronary infusion of the spin trap alpha-phenyl N-tert-butyl nitrone (PBN). In controls (group VI), radical adducts of PBN were released in the coronary venous blood after reperfusion. DF given as in group I (group V) markedly suppressed myocardial production of PBN adducts. These results strongly suggest that a substantial portion of the damage responsible for myocardial stunning is caused by iron-catalyzed free radical reactions that develop in the initial seconds of reperfusion and can be prevented by administration of iron chelators started just before reflow. Furthermore, the results demonstrate that attenuation of postischemic dysfunction by DF is associated with attenuation of free radical reactions in vivo, thereby providing direct evidence for a pathogenetic role of iron-catalyzed free radical reactions in myocardial stunning in the intact animal.

Immune enhancement of a polysaccharides peptides isolated from Coriolus versicolor

A protein-bound polysaccharides (PSP) isolated from Coriolus versicolor in Shanghai, at the concentrations of 100-800 micrograms/ml promoted lymphocyte proliferation. PSP 25 mg/kg ip into mice for 5 d antagonized the inhibition of IL-2 production by cyclophosphamide from activated T lymphocytes and restored the suppressed T-cell-mediated delayed, type hypersensitivity response to normal. PSP 10-1000 micrograms/ml induced interferon alpha and gamma production from human peripheral leukocytes 4 and 8 times respectively higher than that of the control groups. Moreover, PSP also increased phagocytic functions of host reticulo-endothelial system. The results suggest that the anti-tumor effects of PSP may be related to its potentiation of host immunological responses.

Co-evolution from yeast to mouse: cDNA cloning of the two NF-Y (CP-1/CBF) subunits

NF-Y is a CCAAT box binding protein critical for the expression of diverse eukaryotic genes. We have purified the A and B subunits of NF-Y and, using microsequencing and PCR technology, have cloned the corresponding cDNAs. NF-YA and NF-YB show stretches of arresting sequence homology to the yeast transcriptional activators HAP2 and HAP3. Unlike their yeast counterparts, however, the two mouse subunits appear necessary and sufficient for CCAAT binding activity. We hypothesize that in the case of NF-Y, DNA binding and dimerization both rely on residues within the homology domains, which include rather suggestive 'half-finger' motifs.

Carboxypeptidase M in Madin-Darby canine kidney cells. Evidence that carboxypeptidase M has a phosphatidylinositol glycan anchor

Carboxypeptidase M, a plasma membrane-bound enzyme, is present in many human organs and differs from other carboxypeptidase that cleave basic COOH-terminal amino acids. Cultured Madin-Darby canine kidney (MDCK) distal tubular cells contain a kininase I-type enzyme that inactivates bradykinin by releasing Arg9. We found the properties of this kininase to be identical with carboxypeptidase M. In fractionated cells, carboxypeptidase activity sediments with membranes; and detergents, trypsin, and phosphatidylinositol-specific phospholipase C solubilize it, similar to results with human placental carboxypeptidase M. Ten microM 2-mercaptomethyl-3-guanidinoethylthiopropanoic acid and 1 mM o-phenanthroline inhibit, whereas 1.0 mM CoCl2 activates the enzyme. It has a neutral pH optimum and cleaves COOH-terminal Arg or Lys in bradykinin and in shorter peptides. The relative hydrolysis rates of peptides in the presence or absence of 1 mM CoCl2 were similar to those obtained with human carboxypeptidase M. The carboxypeptidase in MDCK cells (54 kDa) cross-reacts with antibodies to human carboxypeptidase M in Western blotting, but not with antibodies to plasma carboxypeptidase N. The enzyme is a glycoprotein; chemical deglycosylation reduced the size to 48 kDa. The presence of the enzyme on the cell membrane of MDCK cells was also shown with transmission electron microscopy using immunogold, which indicated that the enzyme is on the apical side. In addition, MDCK cells contain neutral endopeptidase 24.11 (enkephalinase) and prolylcarboxypeptidase (angiotensinase C) activities. Partitioning of solubilized carboxypeptidase M into Triton X-114 and water indicates that trypsin and phospholipase C remove a hydrophobic tail, while detergent solubilization leaves the hydrophobic moiety intact. Labeling of MDCK cells with [3H]ethanolamine resulted in the synthesis of radiolabeled carboxypeptidase M as determined by immunoprecipitation and fluorography. Thus, MDCK cells contain membrane-bound carboxypeptidase M, which is anchored to the plasma membrane via phosphatidylinositol-glycan. As a major kininase of the distal tubules, it may regulate salt and water excretion.

A peptidase in human platelets that deamidates tachykinins. Probable identity with the lysosomal "protective protein"

We discovered an enzyme in human platelets that deamidates substance P and other tachykinins. Because an amidated carboxyl terminus is important for biological activity, we purified and characterized this deamidase. The enzyme, released from human platelets by thrombin, was purified to homogeneity by ammonium sulfate precipitation, followed by chromatography on an octyl-Sepharose column and chromatofocusing on PBE 94. The purified enzyme exhibits esterase, peptidase, and deamidase activities. The peptidase activity (with furylacryloyl-Phe-Phe) is optimal at pH 5.0 while the esterase (benzoyl-tyrosine ethyl ester) and deamidase (D-Ala2-Leu5-enkephalinamide) activities are optimal at pH 7.0. With biologically important peptides, the enzyme acts both as a deamidase (substance P, neurokinin A, and eledoisin) and a carboxy-peptidase (with bradykinin, angiotensin I, substance P-free acid, oxytocin-free acid) at neutrality, although the carboxypeptidase action is faster at pH 5.5. Enkephalins, released upon deamidation of enkephalinamides, were not cleaved. Gly9-NH2 of oxytocin was released without deamidation. Peptides with a penultimate Arg residue were not hydrolyzed. Some properties of the deamidase are similar to those reported for cathepsin A. The deamidase is inhibited by diisopropylfluorophosphate, inhibitors of chymotrypsin-type enzymes, and mercury compounds while other inhibitors of catheptic enzymes, trypsin-like enzymes, and metalloproteases were ineffective. In gel filtration, the native enzyme has an Mr = 94,000 while in non-reducing sodium dodecyl sulfate-polyacrylamide gel electrophoresis the Mr = 52,000 indicating it exists as a dimer. After reduction, deamidase dissociates into two chains of Mr = 33,000 and 21,000 as determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. [3H]diisopropylfluorophosphate labeled the active site serine in the Mr = 33,000 chain. The first 25 amino acids of both chains were sequenced. They are identical with the sequences of the two chains of lysosomal "protective protein" which, in turn, has sequence similarity to the KEX1 gene product and carboxypeptidase Y of yeast. This protective protein complexes with beta-galactosidase and neuraminidase in lysosomes and is vitally important in maintaining their activity and stability. A defect in this protein is the cause of galactosialidosis, a severe genetic disorder. The ability of physiological stimuli (e.g. thrombin or collagen) to release the deamidase from platelets indicates that it may also be involved in the local metabolism of bioactive peptides.

Enhancement of T lymphocyte proliferation and suppression of antibody producing cell formation by methionine-enkephalin

Methionine-enkephalin (met-enk) 0.1-100 nmol/L significantly enhanced lymphocyte proliferation induced by T cell mitogens. On the other hand, the peptide markedly inhibited splenocyte blastogenesis induced by B cell mitogen lipopolysaccharides (LPS) and sheep red blood cell (SRBC)-driven plaque-forming cell (PFC) formation in vitro. Met-enk alone had no effect on immune responses. However, naloxone 50 nmol/L had also a stimulating effect on Con A-induced splenocyte proliferation. The similar results were also observed in vivo. The results also indicated that the enhancement of T cell function by met-enk was stronger in immunosuppressed mice than in the normal mice.

Rapid serodiagnosis for leprosy--a preliminary study on latex agglutination test

In this study, we have developed two latex agglutination tests (LATs) with phenolic glycolipid-I (PGL-I) and natural disaccharide-octyl-bovine serum albumin (ND-O-BSA) as antigens in 110 leprosy patients (LL = 30, BL = 30, BT = 30, and TT = 20), 50 tuberculosis cases, and 30 normal controls. These two LATs were compared with corresponding ELISAs (ND-O-BSA ELISA and PGL-I ELISA) and analyzed by the chi-squared test. There were no significant differences between the two LATs (PGL-I LAT and ND-O-BSA LAT) and their corresponding ELISAs. There was an increase in the proportion of positive cases detectable which coincided with the clinical classification of leprosy, i.e., lepromatous cases were more likely to be positive than tuberculoid cases. LATs are more simple and rapid than ELISAs and have high sensitivity (77% in ND-O-BSA LAT, 80.5% in PGL-I LAT) and specificity (99% in both LATs). LATs may become useful tools for the immunodiagnosis of leprosy in the field. The stability and repeatability of LATs are discussed in detail.

[Relation of estrogen and bone loss in postmenopausal women]

Seventy-six women were divided into three groups: child-bearing age (A), premenopausal (B) and postmenopausal (C). In addition 14 cases were randomly chosen from group C (0-5 years after menopause) for estrogen treatment (5 micrograms ethinylestradiol daily for one month). Serum levels of sex steroids and alkaline phosphatase (ALP) were determined as an index of bone formation. Ratios of fasting urinary calcium to creatinine (Ca/Cr) and of hydroxyproline to creatinine (Hyp/Cr) were taken as indexes of bone resorption. Radial bone mineral content (BMC) was measured by single photon absorptiometry. In group C serum ALP Ca/Cr and Hyp/Cr were increased by 20%, 31% and 33%, and the respective values were reduced by 11%, 33% and 24% after estrogen therapy. In group C there was a significant lowering of radial BMC as well as serum E1 and E2 levels.

[Study of Ag-NOR, SCE and micronucleus in peripheral blood lymphocyte of chromate producers]

Ag-NOR, SCE and micronucleus test of peripheral blood lymphocyte obtained from 31 chromate producers had been studied. We found that (1) in the workers who had been exposed over eight years, the frequency of Ag-NOR, Ag-AA and SCE were 6.905 +/- 1.100, 0.380 +/- 0.652 and 8.190 +/- 3.727, but in the control group, 6.512 +/- 1.595, 0.215 +/- 0.529 and 7.171 +/- 2.683, respectively. So there was considerably significant difference between the exposed and the unexposed (P less than 0.01); (2) the frequency of micronuclei was 3.71 +/- 1.419% in the exposed group; however, in the control group it was 0.333 +/- 0.479%. So there was also remarkably significant difference between them (P less than 0.001). The observations lead the authors to conclude that the genetic material of the workers who have been working over eight years may be damaged because of being exposed to chromate.

Enhancement of interleukin-1 production in mouse peritoneal macrophages by methionine-enkephalin

Methionine-enkephalin, an endogenous opioid, has been reported to have some effects on immune responses. By thymocyte proliferation method, we herein report that methionine-enkephalin over a wide range of concentrations (1 pmol-0.1 mumol/L) significantly increases both extracellular interleukin-1 release and intracellular interleukin-1 production from peritoneal macrophages induced by lipopolysaccharide in mice. Naloxone, having no effect per se on interleukin-1 production, does not block the enhancing effect of the neuropeptide. Interleukin-1 production was also elevated following ip methionine-enkephalin into mice. The results suggest that methionine-enkephalin mediates the enhancement of interleukin-1 synthesis and release as well, and that the effect is not mediated through classical opioid receptors. The results also provide the further links between immune and nervous systems.

[Pheochromocytoma and adrenomedullary hyperplasia]

A comparison was made on the main clinical features between 6 cases of benign pheochromocytoma and 4 cases of adrenomedullary hyperplasia admitted in to our hospital from 1981 to 1986. It is found that differentiation between pheochromocytoma and adrenomedullary hyperplasia with symptoms or signs alone is difficult, since both may have the same symptoms such as paroxysmal or sustained hypertension elevation and shock. Moreover, the laboratory findings of the former were also similar to those of the latter. So the diagnosis of both was suspected upon clinical manifestations and confirmed with biochemical investigation. If an enlarged adrenal silhouetteis shown on one side or both sides with no tumor mass, as evidenced by retroperitoneal pneumography, computerized tomography, nuclear magnetic resonance, ultrasonography or 131I-meta-iodobenzyl-guanidine (131I-mIBG), adrenomedullary hyperplasia might be considered. Confirmatory differential diagnosis between the pheochromocytoma and adrenomedullary hyperplasia perhaps can only be made after surgical exploration and pathological examination. Pheochromocytoma is usually benign and can be excised totally after medical preparation with an alpha-adrenergic antagonist as we have done; adrenomedullary hyperplasia can only be treated with subtotal adrenalectomy. We also agree with the idea that preoperative alpha-adrenergic blockage would reduce surgical complication and mortality. It is generally recommended that a beta-adrenergic antagonist, such as propranolol, be given only after effective alpha-adrenergic blockade is established because beta-adrenergic blockade alone may exacerbate hypertension as a result of unopposed alpha-adrenergic stimulation. Besides operation, 131I-mIBG administration seems to be a promising alternative method for malignant pheochromocytoma or adrenomedullary hyperplasia.

Serological activity of natural disaccharide octyl bovine serum albumin (ND-O-BSA) in sera from patients with leprosy, tuberculosis, and normal controls

We studied the natural disaccharide-octyl-bovine serum albumin (ND-O-BSA) enzyme-linked immunosorbent assay (ELISA) in sera from 151 leprosy patients, 20 tuberculosis patients, and 42 normal persons from a nonendemic area. The three ELISAs, whole Mycobacterium leprae (WML), phenolic glycolipid-I (PGL-I), and ND-O-BSA, are all highly sensitive for detecting antibodies against M. leprae. The results indicate that the serological activity has highly significant, positive correlations among the three types of antigens used. Their positivity rates are 100% with PGL-I and 97.4% with WML and ND-O-BSA in leprosy patients, and 0% with any antigen used in normal persons at NV-a (a supposed theoretical normal value). However, all three antigens show crossreactivity with tuberculosis patients at different levels. At NV-c (a supposed practical normal value, PNV), this crossreaction significantly decreased in the WML ELISA (PNV = 0.28) and the PGL-I ELISA (PNV = 0.16), and disappeared in the ND-O-BSA ELISA (PNV = 0.20). Under the same conditions, the positivity rates did not decrease significantly in leprosy patients, especially in multibacillary patients. Therefore, we suggest that the PGL-I ELISA in combination with the ND-O-BSA ELISA may be very useful for clinical applications, serodiagnosis, and for the study of subclinical infection in leprosy.

Autoantibody to the proliferating cell nuclear antigen neutralizes the activity of the auxiliary protein for DNA polymerase delta

Two murine monoclonal antibodies to the proliferating cell nuclear antigen (PCNA), a rabbit anti-N-terminal peptide antibody and human auto-antibody to PCNA reacted with the auxiliary protein for DNA polymerase delta from fetal calf thymus following SDS-polyacrylamide gel electrophoresis, confirming the identity of PCNA and the auxiliary protein. Undenatured auxiliary protein was immunoprecipitated by the human autoantibody, but not by the monoclonal antibodies, which were raised to SDS-denatured PCNA, nor by the anti-N-terminal peptide antibody, suggesting that the epitopes recognized by both the monoclonal antibodies and the anti-peptide antibody are not exposed in the native protein. The human anti-PCNA autoantibody neutralized the activity of the auxiliary protein for DNA polymerase delta, but did not inhibit the activity of pol delta itself. The ability of pol delta to utilize template/primers containing long stretches of single-stranded template was inhibited by the anti-PCNA autoantibody, whereas the activity of pol alpha on such templates was not affected, confirming the specificity of the auxiliary protein for pol delta. The ability of PCNA, a cell cycle-regulated protein, to regulate the activity of pol delta suggests a central role for pol delta in cellular DNA replication.

Determination of antibodies in dried blood from earlobes of leprosy patients by enzyme-linked immunosorbent assay--a preliminary report

An enzyme-linked immunosorbent assay (ELISA) was used with soluble antigens of Mycobacterium leprae. All blood samples collected from the earlobes of 109 leprosy patients and 100 healthy controls (from a non-endemic area of leprosy) were absorbed with M. vaccae, BCG, cardiolipin, and lecithin according to the technology of the FLA-ABS test before being tested in the ELISA. The results (at a 1:200 blood dilution) showed that antibody activity gradually increased from TT to LL (mean OD values: TT = 0.43, BT = 0.62, BB = 0.72, BL = 0.84, LL = 0.89), and the rates of positive reactions were 100% in all classifications of patients except TT (66.6%). Antibody activity in the controls was less pronounced than in leprosy patients, their mean OD value being only 0.15. We suggest that the ELISA is highly sensitive and specific for the determination of anti-M. leprae antibodies, and is useful for clinical serodiagnosis and for the study of subclinical infections in leprosy.

Nuclear pore complex in spermatogenesis of Beijing domestic duck. Electron microscope observation of freeze-etching

The nuclear pore complex in spermatogenesis of Beijing domestic duck has been studied by means of electron microscopic observation of freeze-etching. The structure of the pore observed proves to be in accord with the model of the nuclear pore complex proposed respectively by Franke (1970) and Roberts et al. (1970). But its central granule may be present (1-3 granules) or absent. The granules are considered to be material in transit. The size and frequency of the pore vary with different types of reproductive cells, which is believed to be related to the cells' function. The pores concentrate on the side of nucleus near Golgi zone in primary spermatocyte and near the proacrosome of spermatid, and this shows the functional variety of parts in the nucleus.

Natural antibodies against a polysaccharide (Bo) from sugar cane mediate its complement-activating effect

The interaction of a complement activating glucan from sugar cane (Bo) with immunoglobulins was studied. Bo precipitates a small fraction of IgG from human serum. In combination with this fraction, it activates complement by the classical pathway, not in its absence. Bo is adsorbed to and can be eluted from Sepharose containing covalently coupled IgG; it is not bound when the IgG-Sepharose is lacking the Bo-reactive IgG fraction. Bo-IgG complexes activate and fix C1. The binding of C1 to aggregated IgG is not inhibited by Bo. This is in contrast to the strong inhibition of C1 fixation by the Fc-binding protein A. It is concluded that normal human serum contains natural antibodies against Bo which form complement-activating immune complexes with Bo by binding it to their F(ab) region. The antibodies do not cross-react with dextran, a glucan from barley, nor with surface constituents of E. coli.