Pharmacologic properties of KT2-962 (6-isopropyl-3-[4-(p- chlorobenzenesulfonylamino)-butyl]-azulene-1-sulfonic acid sodium salt); a new TXA2/prostaglandin endoperoxide receptor antagonist

Pharmacologic properties of KT2-962 (6-isopropyl-3-[4-(p-chlorobenzenesulfonylamino)butyl]-azulene+ ++-1-sulfonic acid sodium salt, KT) were studied in isolated rat aorta, rat tail artery, rabbit aorta, rabbit renal artery, and pig coronary artery. KT competitively inhibited the contractions induced by thromboxane A2 (TXA2) mimetic, U46619 (pA2 values 9.95, 8.85, 7.87, 8.49, and 9.12, respectively). KT also inhibited the contraction of rabbit aorta induced by prostaglandin2 alpha (PGF2 alpha, pA2 value 7.85) and the contraction of guinea pig ileum induced by LTD4 (pA2 value 5.48) but did not alter the contractions induced by norepinephrine (NE), Ca2+, serotonin, and histamine. KT did not alter the contractions of guinea pig ileum, which did not contract with U46619, induced by PGE2 and PGF2 alpha. KT inhibited the aggregations of rabbit platelets induced by U46619, arachidonic acid, and collagen (IC50 values 7.9, 140, and 16 microM, respectively) but not those induced by ADP. It also inhibited the specific binding of TXA2/PGH2 receptor antagonist, [3H]SQ29,548, to rabbit gel-filtered platelets with an IC50 value of 1.5 x 10(-8) M. In in vivo experiments with mice, oral administration of KT protected the U46619-induced sudden death with the minimum effective dose of 0.3 mg/kg and provided such protection for > 8 h at 1.0 mg/kg. These results indicate that KT is a new nonprostanoid type TXA2/PGH2 receptor antagonist that is orally effective and long acting.

[A comparative study of "angioblastic meningioma", hemangiopericytoma and cerebellar hemangioblastoma]

Forty-nine cases of the so-called "angioblastic meningioma", six cases of cerebellar hemangioblastoma, and four cases of soft tissue hemangiopericytoma were studied with HE, reticulin stainings, and immunohistochemical reaction with Vimentin, EMA, GFAP, S-100, and UEA-1 antibodies. The results showed that among the three subtypes of "angioblastic meningioma", namely, the hemangiomatous (H), the hemangioblastic (AB), and the hemangiopericytic (P) types, (1) type H belongs to true meningioma; (2) most of type P are almost identical with soft tissue hemangiopericytoma and different from true meningiomas, therefore belong to hemangiopericytoma arising from pericytes; however (3) some true meningiomas may appear as hemangiopericytoma histologically; (4) a few of AB are very similar to cerebellar hemangioblastoma and thus should be considered as supratentorial hemangioblastoma, while most of AB are still true meningiomas.

Factors (TAFs) required for activated transcription interact with TATA box-binding protein conserved core domain

TFIID is a multisubunit protein containing the TATA box-binding polypeptide (TBP) and associated factors (TFIID-TAFs) required for activated transcription by RNA polymerase II. TBPs from different eukaryotes contain a highly conserved carboxy-terminal domain and very divergent amino-terminal domains. Earlier studies proposed that the amino-terminal domains of metazoan TBPs are required for activated transcription. However, we report that a human TFIID complex containing an amino-terminal truncated TBP contains all the major TFIID-TAFs and supports in vitro transcriptional stimulation by different classes of activation domains and from a TATA-less promoter. Protein blotting experiments revealed direct interactions between the conserved domain of TBP and the two largest TAFs. The results suggest a model for the interaction of TFIID-TAFs with TBP.

Cytotoxicity of oxysterols on cultured smooth muscle cells from human umbilical arteries

The lethal effect of 25- and 26-hydroxycholesterol on smooth muscle cells derived from human umbilical arteries was investigated. The extent of cellular death corresponded with increasing oxysterol concentrations and incubation times. Incubation of the cells with 0.5, 2.5, or 10 micrograms/ml of 25- or 26-hydroxycholesterol revealed a proportionality between the degree of cellular death and oxysterol concentration over the 5 days of the experiment. Correlation coefficients among the degree of cellular death, the exposing period, and oxysterol concentration were significantly different (P < 0.05). However, none of these changes were noted in the smooth muscle cells cultured for 5 days in a medium containing the same concentration of cholesterol or 0.5% ethanol. An increase in the concentration of either serum or cholesterol in the culture medium did not significantly reduce the cytotoxicity of 2.5 micrograms/ml of 26-hydroxycholesterol. The results of this study suggest that oxysterols have an injurious effect on arterial cells, and that the injurious effect could not be altered by cholesterol, which was present at a serum concentration 12 times higher than that of oxysterols.

L-14 lectin recognition of laminin and its promotion of in vitro cell adhesion

The S-type lactose-binding lectins are found in a variety of animal tissues and their primary sequences are highly conserved between species. Little is known, however, about their functions and endogenous ligands. We report here our studies on the carbohydrate binding specificity of one S-type lectin designated L-14, using glycopeptides and glycoproteins from Chinese hamster ovary cells and mouse teratocarcinoma F9 cells. Our studies demonstrate that L-14 binds with high affinity to oligosaccharides containing multiple repeating units (approximately 4) of the disaccharide [3Gal beta 1-4GlcNAc beta 1]n or poly-N-acetyllactosamine (PL) sequence. Interestingly, terminal beta-galactosyl residues are not necessary for high affinity binding of long PL-containing oligosaccharides to L-14. To characterize the glycoprotein ligands for L-14, we applied total [3H]galactose-labeled glycoproteins from differentiated F9 cells to L-14-Sepharose. Laminin was one of the major glycoproteins in both the cells and the media bound by the lectin. The possible functional significance of this interaction is suggested by the fact that in the absence of Ca2+ L-14 can mediate the binding in vitro of both CHO and F9 cells to immobilized laminin. Taken together, these studies demonstrate that L-14 binds with high affinity to laminin and to relatively long PL chains and indicate that L-14 can promote cell adhesion to laminin.

Digital subtraction angiography in the diagnosis of congenital heart diseases: analysis of 60 cases

Ninety-one IVDSA and/or IADSA examinations with 192 injections were performed in 60 patients with congenital heart disease (CHD), including 31 anatomic anomalies. Axial projection was used in 23 patients. Analysis of the results of this series showed that accurate diagnosis by DSA confirmed by cardiac surgery together with definite diagnosis by DSA were obtained in 54 cases (90%). Two cases of nondiagnosis by DSA resulted from a suboptimal DSA method; four cases of partially accurate or mistaken diagnosis determined by cardiac surgery occurred because the axial view was not used and/or the anomalies were too small to be visualized by DSA. To increase the diagnostic accuracy of DSA in CHD, an optimal method of DSA must be selected according to the position of the anomaly and the hemodynamic data, and the axial view should be used to visualize the anomaly clearly in complex cases. In addition, DSA may fail to define a mild anomaly because of its lower spatial resolution.

Thrombomodulin as a marker of radiation-induced endothelial cell injury

Cultured confluent human umbilical vein endothelial cells were irradiated in vitro with 60Co gamma rays at doses from 0 to 50 Gy. After irradiation thrombomodulin was measured at different times over 6 days in the supernatants of endothelial cell culture medium, on the surface of the cells, and within the cells. At 24 h after irradiation, an increase in the release of thrombomodulin from irradiated endothelial cells and an increase in the number of molecules and the activity of thrombomodulin on the surface of the cells were observed; these reactions were dependent on radiation dose. The capacity of the cells to produce and release thrombomodulin was decreased from 2 to 6 days after exposure to 60Co gamma rays. Our data indicate that radiation can injure endothelial cells, and that thrombomodulin may be used as a marker of radiation-induced injury in endothelial cells. The interrelationship between the dysfunction of irradiated endothelial cells and the pathological mechanisms of acute radiation disease is also discussed.

Holo-TFIID supports transcriptional stimulation by diverse activators and from a TATA-less promoter

Transcription factor IID (TFIID) binds to TATA boxes, nucleating the assembly of initiation complexes containing several general transcription factors and RNA polymerase II. Recently, TFIID was shown to be a multisubunit complex containing a TATA box-binding polypeptide (TBP) and several tightly associated polypeptides (TAFs), which are required for transcriptional stimulation by activator proteins. Here, we report the development of a human cell line expressing an epitope-tagged TBP and the immunopurification of a native, high-molecular-weight form of TFIID that supports transcriptional stimulation by several different classes of activation domains. Recovery of basal and activated TFIID transcriptional specific activity was close to approximately 100%. Electrophoretic mobility-shift analysis demonstrated a single major DNA-protein complex. This holo-TFIID contains TAFs of approximately 250, 125, 95, 78, and 50 kD and sediments at 17S. Holo-TFIID produced an extended footprint over the adenovirus major late promoter TATA box and initiator sequence and supported transcriptional activation from a promoter lacking a TATA box. These results lead us to hypothesize that a single multisubunit TFIID protein supports transcriptional stimulation by diverse activation domains and from a TATA-less promoter.

Pre- and postoperative sequential study on the serum gastrin level in patients with lung cancer

Serial changes in serum gastrin level were detected by radioimmunoassay in 58 lung cancer patients before and after operation. In comparing these tests with those of 40 cases of noncancerous thoracic lesions and 151 normal adults, the serum gastrin from lung cancer patients is significantly higher than that of noncancerous thoracic lesions and normal individuals (P less than 0.01). The gastrin level is closely related to stage of cancer, size of primary tumor, presence of lymph node metastasis, and type of histological classification. The serum gastrin was found to decrease gradually after the removal of the tumor and to return to normal on the 14th postoperative day. Those patients whose serum gastrin level can return to normal on the 14th postoperative day will have a good prognosis; if not, their prognosis will be very poor. These results suggest that serum from patients with lung cancer contains a high concentration of gastrin that can help differentiate benign from malignant thoracic lesions and evaluate prognosis of patients with lung cancer. Therefore, the cause of high serum gastrin in patients with lung cancer is likely due to the gastrin-producing property of the lung cancer cells.

Individual dorsal morphogen binding sites mediate activation and repression in the Drosophila embryo

The dorsal (dl) morphogen gradient is responsible for initiating the differentiation of the mesoderm, neuroectoderm and dorsal ectoderm in the Drosophila embryo. dl encodes a sequence-specific DNA binding protein that belongs to the Rel family of transcription factors. Previous studies have shown that dl activates the mesoderm determinant twist (twi); here we use a combination of site-directed mutagenesis and P-transformation assays to demonstrate that it also functions as a direct transcriptional repressor of a second target gene, zerknüllt (zen). By exchanging dl binding sites between the promoters we show that activator sites from twi can mediate repression when placed in the context of the zen promoter, and that repressor sites from zen can mediate activation in the context of the twi promoter. This represents the first demonstration that common binding sites for any DNA binding protein can mediate both activation and repression in a developing embryo. Evidence is also presented that the affinities of dl binding sites are important for the efficiency of repression, but are not the sole determinants of the threshold response to the dl gradient.

[Experimental study of atherosclerosis and cholelithiasis with the same treatment. I. Effects of yiqi huoxue and shugan liqi agents in atherosclerosis of rabbit]

This paper reports the treatment with Yiqi Huoxue and Shugan Liqi agents in atherosclerosis of rabbit. The results suggested: 1. Both decoctions could reduce the cholesterol of hypercholesterolemia and improve the atherosclerosis, but the former was better than the latter. 2. Both decoctions could alter the components of bile lipids, but on the contrary, the latter was better than the former in reducing the formation of gallstones. 3. Both decoctions could decrease the plasma concentration of LPO and ratio of TXB2/6-K-PGF1 alpha, while increase the ratio of cAMP/cGMP in plasma. So, the different prescriptions of TCM affecting the same link of pathogenesis might play the role of "Different Treatments in Same Disease".

The diagnostic significance of gastrin measurement of bronchoalveolar lavage fluid for lung cancer

In this study, determination of gastrin concentration in bronchoalveolar lavage fluid and serum has been detected by radioimmunoassay in 30 cases of lung cancer and 24 cases of non-cancer pulmonary diseases. The results show that the gastrin concentration and its positive rate of lavage fluids from cancer lung are much higher than those from healthy lung and serum in lung cancer patients, and those from serum and both disease and healthy lung in non-cancer pulmonary disease patients (P less than 0.01). The gastrin ratio of lavage fluids from cancer lung to serum is also significantly higher than the ratio of lavage fluid from healthy lung to serum and all the ratios in the non-cancer pulmonary disease group. These results suggest that there is a high gastrin concentration in local tissue of lung cancer, which is signified by the high concentration of gastrin and its high positive rate in lavage fluids from the lung with cancer. Therefore, the gastrin determination in lavage fluids and gastrin ratio of lavage fluids to serum are more reliable in the differential diagnosis of benign from malignant pulmonary diseases than gastrin determination of serum alone.

Clinical application of radioimmunoimaging in the detection of tumors--current status in China

In this article, the development of radioimmunoimaging (RII) in China is reviewed. Since 1984 conventional heterologous specific antibodies (Abs), such as anti-carcinoembryonic antigen (CEA) and anti-alphafetoprotein (AFP) Abs, have been used to detect cancers of the colon, ovary, lung, liver, etc. Later on, Abs against specific tumor cell-associated antigens have been produced in many institutions and applied clinically, with quite satisfactory results (detection rate ranging from 80-90%). Recently, human monoclonal antibodies (McAbs) are also being prepared. Finally, the existing problems to be overcome are discussed.

Mode of relaxing action of FK336, a new antianginal agent, in rabbit aorta

1. FK336 (10(-6)-10(-4) M) inhibited contractile responses to norepinephrine (NE), KCl and Ca2+ in isolated rabbit aortas. 2. Relaxing effect of FK336 on KCl-response was inhibited by nitroglycerin (NG), but not by nifedipine or verapamil. 3. FK336 inhibited residual NE response and a subsequent Ca2+ response in Ca(2+)-free medium. FK336 did not affect the inositol monophosphate level. 4. Relaxing effect of FK336 on NE response was inhibited by methylene blue, NG, K(+)-channel inhibitors and acetylcholine (ACh), and potentiated by M&B 22,948 and theophylline. 8-Br cGMP and dibutyl cAMP had no effect. 5. FK336 increased cGMP level in rat aorta. 6. Potentiation of isoproterenol-relaxation by FK336 was inhibited by methylene blue. 7. The inhibitory effect of ACh on FK336-relaxation was eliminated by endothelium removal, nordihydroquaiaretic acid and guinacrine, but not by indomethacin. These treatments themselves did not affect FK336-relaxation. 8. The mode of vasorelaxing action of FK336 is discussed.

[Flow cytometric analysis of bone marrow cell cycles in patients with hematologic diseases]

Cell cycle phases of bone marrow cells from 8 patients with iron deficiency anemia (IDA), 8 aplastic anemia (AA), 30 myelodysplastic syndrome (MDS), 41 acute leukemia (AL) before treatment, 8 acute leukemia in relapse, 17 acute leukemia in complete remission (CR), 12 chronic myelogenous leukemia (CML) and 4 chronic lymphocytic leukemia (CLL) were analysed with flow cytometry. The proportions of phases of S. G2 M in patients with IDA, refractory anemia, and refractory anemia with ring sideroblast were similar to these in normal controls (P > 0.05). However, they were significantly lower in patients with AA, refractory anemia with excess of blast (RAEB) and transformed RAEB than those in normal controls (P < 0.01, respectively), and CML patients than in normal controls (P < 0.05). The S G2M% was apparently higher in patients with CML than that in CLL (P < 0.01). But, there was no difference between in ALL and ANLL (P > 0.05). It was higher in patients with AL in CR and in relapse than AL before treatment (both P < 0.01). It was still lower in the former than that in normal controls. (P < 0.05). The clinical significance of cell cycle status was also discussed in this paper.

[A regimen of DATV in the treatment of acute nonlymphocytic leukemia with high complete remission rate]

Thirty-eight adults including 24 males and 14 females with acute nonlymphocytic leukemia were treated with DATV (Daunorubicin, Cytarabine, 6-thioguaninum, Vincristine) regimen from December 1987 to May 1991. The median age was 31 years old (range 13-54). The DATV regimen consisted of DNR 60 mg/day IV for 3 days; Ara-C 100 mg by continuous infusion every 12 hours for 7 days; 6-TG 150 mg PO for 7 days and VCR 2mg IV on day 1.

RESULTS

Complete remission (CR) was achieved in thirty-three of 38 patients after 1-2 courses (mean 1.3) with CR rates 86.8%. Five patients had no response to the regimen. Twenty-four of 33 patients who achieved CR are still in CR for 1-41 months with a median follow-up of 10 months.

A comparison of D1 receptor binding and mRNA in rat brain using receptor autoradiographic and in situ hybridization techniques

D1, a subtype of the dopamine receptors, is widely distributed in the nervous system and has been shown to be positively coupled to adenylate cyclase. Using a combination of in vitro receptor autoradiographic and in situ hybridization techniques, the present study examines the co-distribution of D1 receptor binding sites and D1 receptor mRNA in adjacent rat brain sections. D1 receptor binding sites were labeled using the selective antagonist [3H](R)-(+)-8-chloro-2,3,4,5-tetrahydro-3-methyl-5-phenyl-1H-3-benzaz epin- 7-ol (SCH23390) (4.6 nM), in the presence of 1 microM ketanserin, while the D1 receptor mRNA was visualized with a 35S-labeled riboprobe corresponding to a region between transmembrane domains III and VI of the rat D1 receptor (base pairs 383-843). Analysis of serial sections suggested a good agreement between D1 receptor binding and mRNA in several brain regions, including the paleocortex, caudate-putamen, nucleus accumbens, amygdala, and suprachiasmatic nucleus. Marked discrepancies between D1 receptor binding and mRNA were observed in other brain regions including the entopeduncular and subthalamic nuclei, substantia nigra (pars reticulata), hippocampus, and cerebellum. While technical considerations may contribute to these results, much of the discordance between the distributions is probably due to the differential localization of D1 receptor mRNA in cell bodies and receptor binding sites on fibers and may provide insights into receptor synthesis, transport, and membrane insertion. In the basal ganglia, for instance, D1 receptors are synthesized in the striatum and are either transported to efferent projections in areas such as the substantia nigra, or remain localized in striatal cells bodies. Ibotenic acid lesions in the striatum are consistent with these conclusions and demonstrate a coordinate loss of D1 receptor binding and mRNA in the caudate-putamen that is accompanied by a degeneration of fibers projecting to substantia nigra and a loss of D1 binding in the pars reticulata. Neurons in the dentate gyrus and in the granular layer of the cerebellum, on the other hand, synthesize D1 receptors and transport them entirely to either their dendritic or axonal fields, respectively, in the molecular layer. This analysis provides a better understanding of dopaminergic receptor systems in the CNS and their anatomical organization.

Characteristics of vasoinhibitory action of FK 453 (a pyrazolo-pyridine derivative), a new antihypertensive agent with diuretic action in isolated rabbit aorta

The vasoinhibitory effect of FK 453 was examined in isolated rabbit aorta. FK 453 inhibited contractile responses to norepinephrine, angiotensin-I and KCl. Pretreatment of the tissue with FK 453 failed to affect the relaxing effect of verapamil on the KCl response and the inhibitory effect of prazosin on the phenylephrine response. FK 453 inhibited both the residual norepinephrine response and the subsequent Ca2+ response in a Ca(2+)-free medium containing EGTA and nifedipine. The inhibitory effect of a combined treatment with either FK 453 plus nitroglycerin or FK 453 plus theophylline, but not with FK 453 plus M & B 22,948 (2-o-propoxyphenyl-8-azapurine-6-one; May & Baker), was much greater than that of any single treatment. Pretreatment with FK 453 also potentiated relaxing effects of nitroglycerin and isoproterenol on the PGF2 alpha response. The effect of a combined treatment with FK 453 plus theophylline, but not with FK 453 plus M & B 22,948, was much greater than that of any single treatment. FK 453 also inhibited the activity of phosphodiesterase from canine aorta to convert cyclic [3H]-GMP and cyclic [3H]-AMP to 5'-GMP and 5'-AMP, respectively. These results suggest that the inhibitory action of FK 453 is not due to inhibition of voltage-operated Ca2+ channels or alpha-adrenoceptors, but due to increase in cyclic GMP level.

The selectin GMP-140 binds to sialylated, fucosylated lactosaminoglycans on both myeloid and nonmyeloid cells

Granule membrane protein-140 (GMP-140) is an inducible receptor for myeloid leukocytes on activated platelets and endothelium. Like other selectins, GMP-140 recognizes specific oligosaccharide ligands. However, prior data on the nature of these ligands are contradictory. We investigated the structural features required for ligand interaction with GMP-140 using purified GMP-140, cells naturally expressing specific oligosaccharides, and cells expressing cloned glycosyltransferases. Like the related selectin endothelial leukocyte adhesion molecule-1 (ELAM-1), GMP-140 recognizes alpha(2-3)sialylated, alpha(1-3)fucosylated lactosaminoglycans on both myeloid and nonmyeloid cells, including the sequence Neu5Ac alpha 2-3Gal beta 1-4(Fuc alpha 1-3)GlcNac beta-R (sialyl Lewis x). Recognition requires sialic acid, because cells expressing large amounts of Lewis x, but not sialyl Lewis x, do not interact with GMP-140. Although sialyl Lewis x is expressed by both myeloid HL-60 cells and CHO cells transfected with an alpha 1-3/4 fucosyltransferase, GMP-140 binds with significantly higher affinity to HL-60 cells. Thus, the sialyl Lewis x tetrasaccharide may require additional structural modifications or specific presentations in order for leukocytes in flowing blood to interact rapidly and with high affinity to GMP-140 on activated platelets or endothelium.

[Plasma PGI2 and TXA2 levels on a model of PDH in leptospirosis]

Guinea pigs were intravenously injected with icterhemorrhagiae serogroup Lai serovar strain 017 leptospirosis to model the pulmonary diffuse hemorrhage (PDH) in leptospirosis. Thirty-eight hours after the injection, the jugular arteries were catheterized to collect blood sample. The plasma was prepared for radioimmunoassay of TXB2 and 6-keto-PGF1a, the stable metabolites of TXA2 and PGI2 respectively. The plasma level of TXB2 in the experimental group, 107.15 +/- 41.65 pg/ml (n = 7), almost doubled that of the control, 54.05 +/- 12.93 pg/ml (n = 7), with significant difference (P less than 0.01); meanwhile, no significant difference was observed of 6-keto-PGF1a, 67.97 +/- 16.89 pg/ml (n = 6) vs. 98.06 +/- 40.63 pg/ml (n = 9) with P greater than 0.1. The fact that TXA2 causes vasoconstriction and increases vessel permeability suggests that TXA2 elevation should play a role in the mechanism of PDH in leptospirosis.

Neuropeptide Y stimulates prostacyclin production in porcine vascular endothelial cells

We investigated the effects of neuropeptide Y on the prostacyclin production of cultured porcine aortic endothelial cells by measuring the stable metabolite of prostacyclin, 6-keto-prostaglandin F1 alpha, by radioimmunoassay. Neuropeptide Y induced dose- and time-dependent stimulation of prostacyclin production by cultured porcine aortic endothelial cells. The lowest stimulatory concentration of neuropeptide Y was 10(-8) M and maximal response, a 2.8 fold rise, was obtained with 10(-6) M. The stimulation lasted at least 24 h. The effect was associated with the stimulation of arachidonic acid release. Our data suggest that neuropeptide Y may inhibit the development of atherosclerosis by stimulating prostacyclin synthesis.

The effect of cholesterol on the accumulation of intracellular calcium

Cholesterol/egg phosphatidylcholine (PC) liposomes (1:1 or 4:1, M/M), in which the absolute amount of PC was adjusted to be the same, were incubated with cultured bovine arterial smooth muscle cells for up to 8 h at 37 degrees C. The effect of increased cellular cholesterol on the accumulation of intracellular calcium in these cells was studied. The results indicate that the intracellular calcium content, measured by Fura-2/AM, was increased 2.3-fold by incubation with 4:1, cholesterol/PC liposomes. Kinetic analysis using 45Ca2+ indicated that the increased calcium influx was due to increase of pool size, not from a change of rate constant. (Ca2+ + Mg2+)-ATPase activity was decreased by 4:1, cholesterol/PC liposomes. The molar ratio of cholesterol/phospholipids in the cell membranes was directly proportional to that in liposomes. No change in phospholipid composition was noted. We suggest that the accumulation of intracellular calcium was a composite result due to the altering effect of inserted cholesterol on surface area, and to direct interactions between cholesterol and the proteins of the Ca2+ channel and (Ca2+ + Mg2+)-ATPase.

[Assay of stilbene glucoside in Polygonum multiflorum Thunb and its processed products]

This paper reports the assay of stilbene glucoside in the root of Polygonum multiflorum and its two processed products by first derivative spectrophotometry. The method is simple, convenient and the the results are stable and reproducible. It can be used for the quality control of processing Polygonum multiflorum.

[Central norepinephrine and angiotensin II contents in the brain regions of spontaneously hypertensive rats (SHR) and the interaction between them]

The norepinephrine (NE) and angiotensin II (A II) contents in the brain regions of SHR and WKY (Wistar Kyoto) rats at different ages were determined by fluorospectrophotometry and radioimmunoassay. The systolic blood pressure (SBP) of the rats was measured indirectly with a tail cuff technique in conscious state. The results were as follows: There was no significant difference in the central A II and NE contents between SHR and WKY rats at 8-week age. Since 12th week age the SBP of SHR has increased gradually, up to 16th to 20th week and then maintained steady level. Whereas there was no significant change of SBP in WKY rats in the same span of age. In the early and late states of hypertension the A II contents in the medulla oblongata, pons, hypothalamus and nucleus caudatus of SHR were markedly higher than those of the age-matched WKY rats. But the change of NE content of SHR in the early stage showed a different picture as compared with that of WKY rats, i.e., NE decreased in medulla oblongata and anterior hypothalamus but increased in pons, posterior hypothalamus and nucleus caudatus. However, in the late stage there was no such significant difference between SHR and WKY rats. Consequently, it is suggested that the central A II and NE participated in the development of hypertension of SHR, and that the maintenance of hypertension is mainly dependent upon the increased A II content. Microinjection of captopril or 6-OHDA in the lateral cerebroventricle of SHR elicited a decrease of BP and reduction of both A II and NE contents in the medulla and hypothalamus.(ABSTRACT TRUNCATED AT 250 WORDS)

The effect of 25-hydroxycholesterol on accumulation of intracellular calcium

Liposomes prepared with 25-hydroxycholesterol and egg phosphatidylcholine (PC) were incubated with bovine arterial smooth muscle cells for 8 h at 37 degrees C. Cells incubated in the absence of liposomes or with liposomes containing cholesterol and PC were used as controls. The results indicated that calcium accumulated in the smooth muscle cells incubated in the presence of 25-hydroxycholesterol containing liposomes in an amount proportional to the time of incubation. The calcium accumulation, as indicated by kinetic analysis, resulted from an increased compartment size. (Ca(2+)+Mg2+)-ATPase exhibited decreased activity after pretreatment with 25-hydroxycholesterol containing liposomes and the increased intracellular calcium content was directly proportional to the decreased (Ca(2+) + Mg2+)-ATPase activity. When lipids in the cell membrane were examined, a failure to change the cholesterol/phospholipids ratio in the membrane was noted. The 25-hydroxycholesterol content in the membrane determined by HPLC did not increase. An increase in sphingomyelin and a decrease in phosphatidylethanolamine and acidic phospholipids in the membrane was noted. We suggest that the accumulation of intracellular calcium comes from both an increase of calcium influx and a decrease of (Ca(2+) + Mg2+)-ATPase activity, which may be the consequence of changes in membrane phospholipid composition.

Reduced absolute rate of myo-inositol biosynthesis of cultured bovine retinal capillary pericytes in high glucose

De novo biosynthesis of myo-inositol (MI) by permeabilized cultured bovine retinal capillary pericytes (BRCP) and feline retinal pigment epithelial cells (FRPE), grown in different concentrations of glucose, were studied. After incubation with a physiological concentration of [14C]glucose 6-phosphate (G6P), the radioactive G6P derivatives were quantitated by a single HPLC column. Based on the determined specific activity of [14C]G6P, activities of inositol 1-phosphate synthase (MI synthase) were calculated. The activity of MI synthase was reduced 48% by growing BRCP in a high-glucose medium (20 mM) in comparison with that in the normal medium (glucose 5 mM). In contrast, the de novo MI biosynthesis by FRPE was not changed with increasing concentrations of glucose in the medium. As compared with MI uptake previously studied, the synthesized MI contributes a substantial proportion of cellular MI pool in BRCP. Therefore, in BRCP growing in high glucose the reduced MI biosynthesis aggravates the low MI content resulting from the inhibited MI uptake, and thus leads to altered inositol phospholipid metabolism.

The S-type lectin from calf heart tissue binds selectively to the carbohydrate chains of laminin

We report that the S-type lectin in calf heart tissue, termed calf heart agglutinin (CHA), binds to immobilized mouse laminin in ligand blotting and solid-phase radioligand binding assays. When compared with other glycoproteins, radioiodinated CHA binds preferentially to immobilized laminin. The binding is saturable with a Kd of 9.2 x 10(-7) M and is competitively inhibited by nonradiolabeled CHA as well as a similar lectin from porcine heart tissue. Both lactose and N-acetyllactosamine are good inhibitors of binding to laminin but binding is not inhibited by heparin. Exoglycosidase treatments demonstrated that the binding of radioiodinated CHA to laminin is not dependent on terminal sialyl-, fucosyl-, beta- or alpha-linked galactosyl residues, whereas treatment of laminin with endo-beta-galactosidase significantly decreases the lectin binding. Thus, CHA binds selectively to the poly-N-acetyllactosamine chains on complex-type Asn-linked oligosaccharides in laminin.

[Measurement of left ventricular ejection fraction in myocardial infarction by 2-dimensional echocardiography--comparison with radionuclide angiography]

Left ventricular ejection fraction (LVEF) with 4 different algorithms (biplane and single-plane Simpson's rule and ellipsoid area-length method) was measured by 2-dimensional echocardiography (2 DE) in 42 patients with myocardial infarction (MI), and the results were compared with those with equilibrium radionuclide angiography (ERNA). The correlation coefficients were 0.98 for biplane Simpson's rule (apical 4 and 2 chamber view), 0.96 for biplane area-length method (apical 4 and 2 chamber view), 0.81 for single-plane Simpson's rule (apical 4 chamber view), and 0.77 for single-plane area-length method (apical 4 chamber view). The results indicated that biplane method is superior to single-plane method. Biplane area-length method is an alternative simple method for LVEF measurement in patients with MI.

[Effect of the overactivated central renin-angiotensin system on the concentration of brain norepinephrine and epinephrine in stroke-prone spontaneously hypertensive rats and its significances]

The content of norepinephrine (NE) and epinephrine (E) in the brain of spontaneously hypertensive rats has proved abnormal, but the cause remained unknown. It was shown in the recent work that NE content in pons, posterior hypothalamus, nucleus caudatus and E concentration in medulla oblongata, anterior and posterior hypothalamus of 12-week old stroke-prone spontaneously hypertensive rats (SHRSP) were much higher than those of age-matched Wister-Kyoto rats (WKY). SHRSP also showed higher levels of systolic blood pressure (SBP) and brain angiotensin II (A II) than WKY. Intracerebroventricular (icv) perfusion of angiotensin-converting enzyme inhibitor captopril (20 micrograms for each time and three times for each day for four weeks) inhibited the synthesis of brain A II and reduced SBP and NE, E contents in all examined brain areas in SHRSP and WKY. However, the effects of chronically perfused captopril on SBP and brain NE, E levels in SHRSP were much more significant than in WKY. The results indicate that the modulatory effects of central renin-angiotensin system (RAS) on central adrenergic and noradrenergic system might be overactivated in SHRSP, which might partially responsible for the abnormally high levels of NE, E in some of the brain areas of SHRSP.

Cloning of a transcriptionally active human TATA binding factor

Transcription factor IID (TFIID) binds to the TATA box promoter element and regulates the expression of most eukaryotic genes transcribed by RNA polymerase II. Complementary DNA (cDNA) encoding a human TFIID protein has been cloned. The human TFIID polypeptide has 339 amino acids and a molecular size of 37,745 daltons. The carboxyl-terminal 181 amino acids of the human TFIID protein shares 80% identity with the TFIID protein from Saccharomyces cerevisiae. The amino terminus contains an unusual repeat of 38 consecutive glutamine residues and an X-Thr-Pro repeat. Expression of DNA in reticulocyte lysates or in Escherichia coli yielded a protein that was competent for both DNA binding and transcription activation.

[Preliminary studies on the relationship between the blood pressure and renin-angiotensin system in brain and blood vessels in SHRSP]

This work analyzed the relationship between A I concentration in aorta tissue and systolic blood pressure (SBP) in stroke-prone spontaneously hypertensive rats (SHRSP) at different ages. The SBP of SHRSP increased progressively with the age until the age of 20 weeks, when the SBP of SHRSP no longer elevated but sustained at a relatively high and stable level. The A I concentration in aorta of SHRSP was much higher than that of Wistar Kyoto rats at all of the three different ages. Perfusion of captopril into the lateral cerebroventricle of SHRSP for four weeks evoked a considerable decrease of A I concentration in brain as well as a significant reduction of SBP accompanied by a decrement of A I concentration in aorta and concentration of norepinephrine and epinephrine in aorta tissue and plasma. The results further confirm the close relationship between the changed activity of renin-angiotensin system localized in blood vessels during hypertension and the pathogenesis of hypertension, and indicate the possible regulative control of A I generated from central nervous system over the production of A I from blood vessels by means of facilitating the activity of peripheral sympathetic nerve system.

Intramural pericyte degeneration in early diabetic retinopathy study in vitro

An experimental model of diseased pericytes was established by using cultured bovine retinal capillary pericytes in high--glucose medium. The high glucose stimulated polyol pathway, reduced cellular myo-inositol content and disturbed inositol phospholipid metabolism which resulted in a decrease in inositol trisphosphate (IP3) level. The correlation of suppressed IP3 levels with reduced DNA synthesis was evident. These findings suggested the biochemical mechanism by which retinal pericytes degenerate in high glucose. To supplement myo--inositol and/or an aldose reductase inhibitor to the high--glucose medium largely reversed the suppressed IP3 level and the decreased DNA synthesis. Therefore, these two manipulations may be considered as in vitro therapy to treat sick pericytes induced by high glucose.

Characterization of an S-type lectin purified from porcine heart

We have purified a carbohydrate-binding protein from porcine heart by affinity chromatography on asialofetuin-Sepharose and have characterized this protein with respect to its size, amino acid composition, partial amino acid sequence, and carbohydrate-binding specificity. Porcine heart lectin (PHL) has a subunit molecular mass of 14,700 and is immunologically cross-reactive with a polyclonal antibody raised against a lectin isolated from calf heart. The amino acid composition of PHL is similar to that of lectins that have been isolated from calf heart, bovine brain, and rat lung. Moreover, the primary sequences of four tryptic fragments (52 amino acids total) derived from PHL are closely related to sequences previously determined for 10 other vertebrate-derived lectins. The ability of PHL to agglutinate rabbit erythrocytes was inhibited only by oligosaccharides containing terminal beta-galactosyl residues. These data indicate that PHL is a vertebrate "S-type" lectin and provide further evidence that the structures and carbohydrate-binding specificities of these lectins are highly conserved across diverse vertebrate genera.

DNA-synthesis regulation and correlation with inositol trisphosphate levels in cultured bovine retinal capillary pericytes

Inositol phosphate (IP), inositol bisphosphate (IP2) and inositol trisphosphate (IP3) in cultured bovine retinal capillary pericytes (BRCP) were quantitated by an ion-pair reverse-phase HPLC. BRCP were grown in media with standard (5 mM) or high (30 mM) glucose, and were either labeled with myo-[2-3H]inositol (20 microCi ml-1) for 60 hr or with dual isotopes (20 microCi ml-1 myo-[2-3H]inositol and 2 microCi ml-1 [14C]glycerol) for 8 hr. In parallel, BRCP in different glucose-media were incubated with 1 microCi ml-1 [3H]thymidine for 4 hr. High glucose significantly suppressed the accumulation of [3H]label in IP, IP2 and IP3, and specifically reduced the incorporation of [14C]glycerol into inositol phospholipids, but not that of neutral lipids and other types of phospholipids. The reduced IP3 level correlated with the decrease in the incorporation of [3H]thymidine into DNA. Both the reduced IP3 formation and DNA synthesis which were induced by high glucose were significantly reversed by adding either myo-inositol or AL1576, an aldose reductase inhibitor (ARI). However, the addition of neither myo-inositol nor ARI stimulated IP3 formation and/or DNA synthesis when BRCP were grown in the standard medium (5 mM glucose). These findings indicate that myo-inositol metabolism and the polyol pathway affect inositol phospholipid-mediated pericyte division in vitro only under the high-glucose condition. These data are compatible with the hypothesis that altered inositol phospholipid metabolism accounts for the loss of pericytes in diabetic retinopathy.

Sp1 activates transcription without enhancing DNA-binding activity of the TATA box factor

We have studied the interactions of the Sp1 and IID transcription factors with a simple RNA polymerase II promoter. The adenovirus E1B core promoter consists essentially of a GC box and a TATA box, binding sites for the Sp1 and IID transcription factors, respectively. The E1B promoter is accurately transcribed in vitro using a mammalian transcription system. Sp1 activates E1B transcription in vitro in reactions using IID factor isolated from either human or yeast cells. In DNase I footprinting studies, Sp1 bound rapidly to its recognition sequence even at 0 degrees C (t1/2 less than 1 min). In contrast, yeast IID bound more slowly (t1/2 approximately 6 min at 25 degrees C) and required thermal energy for stable binding to the TATA box sequence. Dissociation rates were measured by the addition of specific oligonucleotide competitors to preformed DNA-protein complexes. Sp1 dissociates rapidly (t1/2 less than 1 min) at 25 degrees C, while yeast IID dissociates with an estimated t1/2 of 1 h at 25 degrees C. Sp1 and yeast IID bound to the E1B promoter simultaneously but independently. The rates of binding and dissociation of these factors were not significantly affected by the presence of the other factor. Bound Sp1 factor did not alter or enhance the yeast IID footprint. Oligonucleotide challenge of in vitro transcription reactions indicated that Sp1 also did not enhance the binding of the human IID factor to the E1B promoter. Thus the Sp1 factor activates transcription of the E1B gene by a mechanism that does not enhance the DNA-binding activity of the IID factor. Sp1 factor activates E1B transcription by 5- to 10-fold in vitro. Under these in vitro transcription conditions, transcripts due to reinitiation from an individual promoter complex contribute only a small portion of the total yield of E1B transcripts. Thus Sp1 cannot activate transcription by increasing the rate of initiation events per complex. Instead it appears that Sp1 acts by increasing the number of productive transcription complexes formed in vitro.

Porous plastic optical fiber sensor for ammonia measurement

A porous plastic optical fiber has been developed for use in chemical gas sensing. This porous plastic waveguide, which was made with copolymer materials, has an interconnective porous structure as well as uniformity of pore size. These sensors are based on in-line optical absorption within the porous plastic fiber core and have much greater sensitivities than sensors based on evanescent coupling to a surrounding medium. Furthermore, this fiber simultaneously exhibits very high gas permeability and liquid impermeability. This combination makes the fiber particularly suitable for gas concentration measurements in aqueous samples. An ammonia gas sensor has been tested to demonstrate the effectiveness of this porous plastic waveguide.

The entry of gossypol across the blood-testis barrier in rats

This paper presents the experimental data about how different formulations of gossypol enter the blood-testis barrier following intravenous administration in acute experiments on rats. It was found that gossypol encapsulated by liposomes crossed the blood-testis barrier more readily than free gossypol, without affecting its pharmacokinetic pattern in the circulating blood, suggesting that liposomes may be useful as drug carriers and may facilitate the entry of encapsulated gossypol into the seminiferous tubule from the blood.

Attenuation of phosphoinositidase activity and phosphatidylinositol bisphosphate level of bovine retinal capillary pericytes in high glucose

Both phosphoinositidase (PIase) and individual species of inositol phospholipid (IPL) of bovine retinal capillary pericytes (BRCP) were quantitatively determined. When glucose in growth medium was increased from 5- to 15- or 30 mM, PIase activity was attenuated to 82% or 55%, respectively. In contrast, when glucose (5-, 15-, 30 mM) was added to an enzyme extract from cells grown in the standard growth medium (5 mM glucose, 0.04 mM myo-inositol) the PIase activity was not changed, indicating that the reduced PIase activity was not due to the direct effect of glucose. When IPLs from BRCP were analysed by HPLC and TLC, we observed reduction of the total and newly formed IPLs including the substrate of PIase. Phosphatidylinositol bisphosphate (PIP2). Reduced levels of IPLs were associated with a decrease in myo-inositol and an increase in sorbitol. The changes in IPL metabolism were reversed by adding either free myo-inositol or AL1576, an aldose reductase inhibitor (ARI), to the high-glucose medium. However, the addition of myo-inositol to the growth medium with a standard concentration of glucose only caused a marked increase in phosphatidylinositol, but not in PIP or PIP2, while the supplement of AL1576 in the standard medium did not cause any changes in IPL formation. These findings suggest that the alteration in IPL metabolism in BRCP may be related to insufficient myo-inositol or activated sorbitol pathway under high-glucose conditions. Further explanation of the role of the altered hydrolysis of PIP2 triggered by PIase may provide clues to understanding of the mechanism of decreased pericyte viability in the presence of high glucose concentrations.

Porous optical fibers for high-sensitivity ammonia-vapor sensors

A new porous glass optical fiber has been developed for use as a sensor for the detection of ammonia vapors at low concentrations. The porous structure that remains after selective heat treatment, phase separation, and chemical leaching of a borosilicate glass imparts a high surface area to the fiber core. Ammonia vapors permeating into the porous zone, which is pretreated with a reversible pH dye indicator, produce a spectral change in transmission. The resulting pH change is measured by in-line optical absorbance and is proportional to the ambient-ammonia concentration. Ammonia-vapor concentrations as low as 0.7 part in 10(6) have been detected.

Reduction of inositol triphosphate in retinal microvessels by glucose and restimulation by myo-inositol

The formation of inositol phospholipids (IPLs) and inositol phosphate esters (IPEs) in response to glucose was studied in isolated retinal microvessels from porcine eyes. Retinal microvessels incubated from 60 hr with myo-[3H]inositol were sequentially extracted to obtain IPLs and IPEs. [3H]Inositol-labelled IPLs were deacylated to produce the corresponding glycero derivatives. Both deacylation products and water-soluble IPEs were monitored by anion-exchange chromatography. In the presence of high glucose (30 mM) the labelling in inositol triphosphate (IP3) was reduced to 77% and was restimulated by adding myo-inositol (final concentration 0.4 mM) to 158% of the control under physiological conditions of glucose (5 mM) and myo-inositol (0.04 mM). With a fixed glucose concentration (5 mM), IPE accumulation was observed with increasing concentrations of exogenous myo-inositol. Under physiological conditions (glucose 5 mM, myo-inositol 0.04 mM) the distribution (percentage) of radioactivity in phosphatidylinositol (PI), phosphatidylinositol 4-phosphate (PIP) and phosphatidylinositol 4,5-phosphate (PIP2) was 63:19:18. The myo-inositol concentration dependence of IPL formation was also demonstrated. A decrease in IP3 in response to high glucose without changing PIP2 but with a reduction in PI indicated that PI may act as a reservoir to replace a possible loss of PIP2. These findings suggest that availability of myo-inositol by retinal microvessels may be essential to maintain the normal signal transduction and cell proliferation associated with IPL turnover under high glucose concentration.