Effects of protein kinase C activation on intracellular Ca2+ distribution in vascular smooth muscle cells of spontaneously hypertensive rats

Protein kinase C is known to influence contraction in vascular smooth muscle cells by Ca(2+)-dependent and Ca(2+)-independent mechanisms. In the present study, the effect of protein kinase C activation by phorbol 12-myristate 13-acetate on resting cytosolic free Ca2+ and on cellular Ca2+ pools was assessed in cultured rat aortic muscle cells using fura 2. Cellular Ca2+ pools were evaluated with the selective inhibitor of the sarcoplasmic Ca2+ ATPase, thapsigargin. In normotensive vascular smooth muscle cells, protein kinase C activation caused a redistribution of Ca2+ from the thapsigargin-sensitive pool into the cytoplasm, whereas, in hypertensive cells, no significant effect of protein kinase C activity on cellular Ca2+ distribution was found. It is concluded that protein kinase C modulates the amount of Ca2+ stored in the thapsigargin-sensitive calcium stores. In hypertensive cells, the regulation of Ca2+ pools by protein kinase C is disturbed.

Effect of selenium and protein deficiency on selenium and glutathione peroxidase in rats

Twenty-four weanling male Wistar rats were divided into four groups fed diets containing adequate or deficient levels of selenium (0.5 ppm [+Se] or < 0.02 ppm [-Se] and protein (15% [+Pro] or 5% [-Pro]), but adequate levels of all other nutrients for 4 wk to determine the effects of Se deficiency and protein deficiency on tissue Se and glutathione peroxidase (GSHPx) activity in rats. Plasma, heart, liver, and kidney Se and GSHPx were significantly lower in Se-deficient groups in relation to Se-sufficient groups. In Se-deficient groups, Se and GSHPx were significantly higher in -Se-Pro rats in heart, liver, and kidney. Data analysis showed that there were significant interaction effects between dietary Se and protein on Se and GSHPx of rats. It is assumed that under the condition of Se deficiency, a low level of protein may decrease Se and GSHPx utilization, increase GSHPx synthesis, and result in Se redistribution. This could account for high levels of Se and GSHPx in the -Se-Pro rats compared to -Se+Pro rats.

[Pulmonary function disturbances in patients with hepatic cirrhosis]

The results of five pulmonary function tests on 52 patients with uncompensated hepatic cirrhosis were presented. Compared with matched healthy adults, the patients had decreased values of VC, TLC and DLCO, and their RV/TLC increased (P < 0.05-0.001). Possible pathogenic factors were investigated. The ascites showed evident influences on pulmonary function. In addition to the disorders detected by the above 4 tests, FRC decreased in the patients with ascites. A comparison between the patients with albumin below 30g/L and the patients with albumin above 30g/L revealed that reduced plasma albumin also played role in decreasing VC, TLC and DLCO. Besides the effects of ascites, severe varices of esophagus should have relation to the increase of RV/TLC and the decrease of DLCO.

Glycosphingolipids of rabbit endometrium and their changes during pregnancy

The glycolipids of nonpregnant and pregnant rabbit endometrium were characterized using a combination of biochemical and immunochemical techniques. Quantitative analyses indicated a 70% decline in acidic glycolipid (ganglioside) content during early pregnancy (day 6), and a 2.5-fold increase in neutral glycolipid content during later pregnancy (day 26). The major gangliosides of rabbit endometrium were identified by thin-layer chromatography as GM3 and GD3, with minor amounts of GM1, GD1a and GT1b. The major neutral glycolipids were identified similarly as globo-series structures Gb3 and Gb4. Monoclonal antibodies (mAbs) directed to glycolipid antigens permitted the detection of additional glycolipid species, including sialylated, sulfated and fucosylated lacto-series structures. Difucosyl Ley structure (defined by mAb AH-6) and sulfated-galactosyl structure (defined by mAb VESP 6.2) were identified by indirect immunofluorescence along the luminal surface of the endometrium during the implantation period. Rapid changes in the glycolipid composition of endometrial cells during early pregnancy may facilitate embryo adhesion and trophectoderm outgrowth during implantation.

Primary-structural and evolutionary analyses of the growth-hormone gene from grass carp (Ctenopharyngodon idellus)

The growth-hormone (GH) gene of grass carp, one of the fastest-growing species of farmed fish, was isolated and the DNA sequenced. Only one GH gene is found in this species. This gene, which is 2.5 kb in length, has five exons and four introns, in common with all of the mammalian and the recently published common-carp GH genes. In the course of vertebrate evolution, the total lengths of the intron and the non-coding region of exon 5 of the GH gene have been shortened by 40-70%, whereas the encoding exons of the gene have been slightly increased. The more closely related species exhibit the closest sequence similarity in their GH genes. For example, the similarity of the exons is 84.1-93.2% between grass carp and common carp (within the same family of Syprinedae), 43.5-82.1% between grass carp and rainbow trout (in different orders of Teleostei) and 45.8-58.6% between grass carp and rat (in different grades of Vertebrata). In addition, similar DNA domains, such as thyroid-hormone-receptor-complex-binding site and cell-type-specific cis elements involved in regulation of expression of rat and human GH genes, have been localized in the corresponding regions of the grass-carp GH gene.

[Immune status of the spleen and surgical treatment in patients with advanced gastric cancer]

The immune status of spleen and the effect of surgical treatment in advanced gastric cancer (AGC) patients were evaluated by means of testing NK cell activity, T-lymphocyte subsets and circulating immune complex (CIC). The results showed (1) the significant impairment of NK cell activity and T-lymphocyte subsets, were decreased in CD3+, CD4+ cells and increased in CD6+ cells resulting in CD4+/CD8+ cell ratio decrease in peripheral blood lymphocytes (PBL), splenic venous blood lymphocytes (SVL) and spleen cells (SC) of AGC, as compared with PBL of normal population; (2) NK cell activity or CD4+/CD8+ cell ratio of SVL and SC were significantly lower than those of PBL in AGC patients, mainly caused by marked decrease of CD4+ cells in SC; (3) NK cell activity, CD4+ cells and CD4+/CD8+ cell ratio were significantly elevated in most of AGC cases receiving either radical gastrectomy (R2+) or extensive radical gastrectomy (R3). A striking declination in CD8+ cells were found only after R3 operation; (4) after a short period (10-14 days) or a long period (2-4 years) of radical gastrectomy, NK cell activity and T-lymphocyte subsets showed no significant differences between R2+ and R3 operation. As a rule, AGC would weaken immune function of patients, and along with the development of the tumor, the immunosuppression in the spleen would be generated gradually. For these reasons, a complete tumor resection would be necessary to improve the immunocompetence, and the combined splenectomy might be advisable if indicated.

[Preparation of sucking tablet of shengmei] off

The Sucking Tablet of Shengmei is made from eight Chinese traditional drugs including Radix Adenophorae, Fructus Mume, etc. The effective rate of the tablet in treating chronic pharyngitis reaches up to 96 percent. The working mechanism related to the fact that the tablet is bacteria-resistant and helps to strengthen the body function. This paper presents the preparation process of the Sucking Tablet along with solutions for some problems encountered in the process and appropriate standards for quality control.

[Pharmacological study on spleen-stomach warming and analgesic actions of Aconitum carmichaeli Debx]

This study presents an observation of the anti-inflammatory effect of Aconitum carmichaeli decoction on water-immersion stress induced gastric ulcer in mice and 0.6 mol/L HCl induced gastric ulcer in rats. The observation showed that the decoction was resistant to the castor oil induced and Cassia angustifolia leaf induced experimental diarrhea in mice, and also had marked analgesic action. It is thus suggested that Aconitum carmichaeli is useful clinically as a spleen-stomach warming and analgesic agent in traditional Chinese medicine.

Characterization of AluI repeats of zebrafish (Brachydanio rerio)

Two families of repetitive DNA sequences were isolated from the zebrafish genome and characterized. Eight different sequences were sequenced and classified by two standards, their (G + C) composition and their lengths. For convenience, the sequences were first divided into two types. Type I was (A + T)-rich, was repeated approximately 500,000 times, and constituted approximately 5% of the zebrafish genome. Type II was (G + C)-rich, was reiterated approximately 90,000 times, and comprised approximately 0.5% of the genome. Agarose gel electrophoresis of zebrafish DNA cleaved with AluI revealed three distinguishable bands of repetitive fragments: large (approximately 180 bp, designated RFAL), medium (approximately 140 bp, RFAM), and small (approximately 90 bp, RFAS). The RFAL fragments contained both type I and type II sequences. Limited digestion of genomic DNA indicated that RFAL and RFAM were tandemly arranged in the genome, whereas RFAS showed a mixed pattern of both tandem and interspersed repeated arrangements. Although inclusion of a repetitive sequence in a transgenic construct did not appreciably accelerate homologous integration of transgenes into the zebrafish genome, the AluI sequences could facilitate transgene mapping following chromosomal integration.

Metabolism and DNA interaction of 2',3'-didehydro-2',3'-dideoxythymidine in human bone marrow cells

2',3'-Didehydro-2',3'-dideoxythymidine (D4T) is a potent inhibitor of human immunodeficiency virus (HIV), with low hematological toxicity. In the present study, the cellular pharmacology of D4T was investigated in human bone marrow cells (BMC), in an attempt to understand the mechanism of the observed low bone marrow toxicity. After exposure of human BMC to 10 microM [3H]D4T for 24 hr, D4T-5'-triphosphate (D4T-TP) was the predominant metabolite, reaching a concentration of 0.3 pmol/10(6) cells. The D4T-5'-monophosphate levels were slightly lower, whereas the D4T-5'-diphosphate levels were about 6-fold lower than those of D4T-TP at 24 hr. Nucleic acids of human BMC exposed to 10 microM [3H]D4T for 24 hr were purified and analyzed by cesium sulfate density gradient centrifugation. No radioactivity was detected in the RNA region, whereas a limited amount was associated with the DNA region. The amount of label incorporated into DNA correlated with the extracellular D4T concentration and the length of incubation time. Enzymatic hydrolysis of radiolabeled DNA and subsequent analysis by high performance liquid chromatography demonstrated incorporation of both D4T and thymidine (dThd) into DNA. Degradation of D4T to thymine and subsequent formation of labeled dThd was also detected in human BMC. Pulse (24 hr)-chase (48 hr) experiments with 10 microM [3H]D4T demonstrated that the amount of radiolabel from D4T in DNA decreased over time during the chase. Under similar conditions, [3H]3'-azido-3'-deoxythymidine (AZT) incorporated into DNA of human BMC did not decrease during the chase. Although D4T-TP standard was demonstrated to be unstable at 37 degrees and neutral pH, D4T was much more stable in solution when incorporated into newly synthesized DNA isolated from human BMC, suggesting that enzymatic excision may be the mechanism for D4T removal from DNA. In summary, although higher concentrations of D4T-TP, compared with AZT-5'-triphosphate, are observed in human BMC, after exposure of cells to similar extracellular concentrations of parent drug, steady state levels of D4T incorporated into DNA are 10-50-fold lower, compared with AZT. Competition with dTTP formed by D4T metabolism and excision of D4T from DNA may be responsible, in part, for these effects. This study further demonstrates that incorporation of 2',3'-dideoxynucleosides into nuclear DNA of human BMC may be related to the ability of these anti-HIV agents to induce hematological side effects.

Specific binding and internalization of monoclonal antibody HI98-daunorubicin conjugate by human leukemic cells (HL60)

McAb-HI98 has been proved to bind specifically to HL60 cells. In this study, we further observed the specific binding of HI98-Daunorubicin (DNR) conjugate to HL60 cells, the transmembranal transport of HI98-DNR and the process of internalization by immunoelectron microscopy. After HL60 cells were incubated with HI98-DNR-Au, gold particles were first found on the surface membranes of HL60 cells, and then inside the cells. Internalization was found to occur through the formation of endocytic vesicles. Results indicate that the immunoconjugate selectively binds to target cells and enters the cells specifically and rapidly, thus enhancing intracellular drug concentration.

Kinetic and spectroscopic characterization of the isomers of the allyl bromide molecular ion

The kinetics of the ion/molecule reactions of the molecular ion of allyl bromide (3-bromopropene), C3H5Br(+)., with its neutral show that only (82 ± 2)% of these ions are reactive. This percentage is mildly sensitive to ionization energy below 13 eV, but is pressure insensitive. The collisionless infrared multiphoton-induced photofragmentation of these ions at 10.25 μm and at variable power densities is consistent with the presence of two ionic species in the ratio obtained from the kinetic experiments. The most abundant species undergoes much faster photofragmentation at this wavelength, but at 10.59 μm the photofragmentation rates become comparable. Experiments performed by isolating the remaining molecular ions after completion of the ion/molecule reaction confirm that the unreactive species corresponds to the slow photodissociating ion at 10.25 μm. A combination of kinetic experiments and photodissociation is used to establish that the less abundant species behaves unlike the molecular ion obtained from 1-bromopropene, 2-bromopropene, or bromocyclopropane. The two structures for the molecular ion are shown to originate from ionization and not by isomerization through collisions.

[Pharmacological studies on warming the middle-jiao to alleviate pain by Pericarpium Zanthoxyli]

The pharmacological effects of the ethereal extract and aqueous extract of Pericarpium Zanthoxyli on warming the middle-jiao to alleviate pain have been studied. It is suggested that the effects of Pericarpium Zanthoxyli on antagonizing ulcer, and inflammatory and functional diarrheas, protecting liver, and correcting gastrointestinal disorder are the connotation of its warming the middle-jiao to alleviate pain, its analgesic effect helps to relieve various abdominal pains.

[Changes in circulating endothelial cells in patients with essential hypertension]

To observe the damage of vascular endothelium in vivo, we measured the circulating endothelial cell (CEC) with Hladovec's method in 30 patients with essential hypertension (EH) and 66 normal controls. The CEC was verified by direct immunofluorescent staining using anti-human factor VIII serum. The results showed that a significantly increased CEC count was found in patients with EH (3.018 +/- 1.230 vs 1.310 +/- 0.710, P less than 0.01), but the number of CEC was not parallel to the change of blood pressure quantitatively. After antihypertensive therapy, the CEC count reduced markedly in partial patients (3.371 +/- 0.770 vs 2.410 +/- 0.782, P less than 0.05). The study indicated that the damage of vascular endothelium indeed existed in EH, the abnormality can be improved by antihypertension. The CEC count was a simple and sensitive method for the demonstration of endothelial lesion in vivo.

[Studies on warming the middle-jiao and analgesic effect of flos Caryophylli]

The effects of water extract and ether extract of Flos Caryophylli have been investigated by four experimental gastric ulcer models, choleresis in rats, two diarrhea models in mice, two pain stimulations in mice, and acute liver injury induced by CCl4 in rats. The results suggest that the action of Flos Caryophylli on dispelling the cold by warming the middle-jiao and curing abdominalgia is related to its anti-ulcer, choleresis increasing, anti-diarrhea and analgesic functions.

The peritrophic membrane of Ixodes ricinus

A peritrophic membrane was found in all three stages of Ixodes ricinus at no later than 18 h after their placement on rabbits. It was found to remain intact until at least 11, 30 and 10 days after repletion in larvae, nymphs and females, respectively. In blood-feeding I. ricinus, the peritrophic membrane is an uneven single layer with a thickness of about 0.03-0.48 micron in larvae, 0.03-0.79 micron in nymphs and 0.04-0.93 micron in females. It covers the whole surface of the midgut epithelium at a distance of about 0.2-0.8 micron. After repletion, the peritrophic membrane becomes thicker and thicker and more and more winding and simultaneously becomes multi-layered mainly in its arched parts. The distance between the peritrophic membrane and the midgut epithelium increases considerably and in the arched parts can reach as much as about 13 and 16 microns in metamorphosing larvae and nymphs, respectively and 25 microns in ovipositing females.

Cellular metabolism of 3'-azido-2',3'-dideoxyuridine with formation of 5'-O-diphosphohexose derivatives by previously unrecognized metabolic pathways for 2'-deoxyuridine analogs

3'-Azido-2',3'-dideoxyuridine (AzdU, CS-87) is a potent inhibitor of human immunodeficiency virus replication in human peripheral blood mononuclear cells (PBMC) with limited toxicity for human bone marrow cells (BMC). In the present study, metabolism of AzdU was investigated in human PBMC and BMC after exposure of cells to 2 or 10 microM [3H]AzdU. 3'-Azido-2',3'-dideoxyuridine-5'-monophosphate (AzdU-MP) was the predominant metabolite, representing approximately 55 to 65% of intracellular radioactivity in both PBMC and BMC at all times. The AzdU-5'-diphosphate and -5'-triphosphate intracellular levels were 10- to 100-fold lower than the AzdU-MP levels and, of note, AzdU-5'-triphosphate was not detected in human BMC. Using anion exchange chromatography, a new peak of radioactivity, distinct from any known anabolites, was detected. This chromatographic peak was found to be resistant to alkaline phosphatase but was hydrolyzed by 5'-phosphodiesterase, yielding AzdU-MP. Incubation of [3H]AzdU and D-[1-14C]glucose in PBMC and BMC produced a double-labeled peak with the same retention time as the anabolite, suggesting formation of a hexose derivative of AzdU. A novel high performance liquid chromatography method was developed that allowed for the separation of nucleosides, nucleotides, and carbohydrate derivatives thereof. Using this highly specific method, the putative AzdU-hexose actually was separated into two chromatographic peaks. These novel metabolites were identified as 3'-azido-2',3'-dideoxyuridine-5'-O-diphosphoglucose and 3'-azido-2',3'-dideoxyuridine-5'-O-diphospho-N-acetylglucosamine. Following 48 hr of incubation with [3H] AzdU, as much as 20 and 30% of these AzdU metabolites accumulated in PBMC and BMC, respectively. When AzdU was removed from the cell cultures, intracellular AzdU diphosphohexose concentrations decayed in a monophasic manner, with an elimination half-life of 14.3 hr. By 48 hr, levels of 0.3 pmol/10(6) cells were still detected, reflecting a gradual anabolism of these metabolites. Elimination of AzdU-MP and AzdU-5'-diphosphate was characterized by a two-phase process, with a short initial half-life of 0.83 and 0.24 hr and a long terminal half-life of 14.10 and 8.24 hr, respectively. Similar diphosphohexoses of deoxyuridine (dUrd) were also detected in human PBMC and BMC after exposure to [3H]dUrd, suggesting that dUrd derivatives are metabolized in a similar manner. In summary, the discovery of novel metabolic pathways for dUrd analogs demonstrates that AzdU has unique metabolic features that may contribute to the low toxicity of this anti-HIV agent in human BMC and also affect its mechanism of action.(ABSTRACT TRUNCATED AT 400 WORDS)

Hypomethylation of the interphotoreceptor retinoid-binding protein (IRBP) promotor and first exon is linked to expression of the gene

The interphotoreceptor retinoid-binding protein (IRBP) is limited in expression to retinal photoreceptor cells and a subset of pinealocytes. We have obtained a genomic clone containing the entire coding region and 7 kb of 5' flanking sequence. As a first step in studying IRBP gene regulation we have examined the CpG methylation patterns of the entire IRBP gene in expressing and non-expressing human cells. This has been done by isolation of high molecular weight DNA from Y-79 cells grown in suspension or attached to poly-D-lysine, which synthesize IRBP at different levels, and from human lymphocytes, which were shown by northern analysis to lack IRBP message. The DNA was digested by either Hpa II, Msp I, or Hha I. Southern blots were prepared with these digests and hybridized with probes made from fragments covering the complete genomic clone. Probes from the first exon, the introns and the 3' end gave banding patterns which showed no differences between the expressing cells and the lymphocytes. A probe from the very 5' end did not give a clear banding pattern, probably due to the presence of repetitive elements in the probe. However, a Hind III probe covering the 5' flanking 3 kb and the beginning of the first exon hybridized with a 1.8 kb band in Hpa II digests of Y-79 cells which was not present in Hpa II digests of lymphocyte DNA. In addition, a 2.1-2.3 kb Hha I band was found only in the Y-79 DNA digests. Sequence analysis of the promoter region indicated that these bands were due to hypomethylation of sites within a CpG rich island from -1578 to -1108 in the promoter and hypomethylation of sites in the beginning of the first exon. A Hha I site between the CpG island and the first exon was not hypomethylated in the expressing Y-79 cells. We propose that hypomethylation of the CpG rich island of the IRBP promoter and the first exon is linked to the expression of this gene.

[Preparation of a monoclonal antibody (HI30)-mitomycin C conjugate utilizing dextran T-40 and its specific cytotoxicity against human leukemia cell line CEM]

The anticancer drug mitomycin C (MMC) was conjugated with an affinity-purified murine monoclonal antibody (HI30) to a human T lymphocyte surface differentiation antigen with dextran T-40 as the intermediate carrier. The conjugate (HI30:MMC molar ratio, 1:7) retained full antibody binding activity as determined by an indirect immunofluorescence assay. E. Coli HB101 growth inhibition test showed that the antimicrobial activity [MMC equivalent (microgram/ml)] of the conjugate was about 29.2% as potent as free MMC. In a cytotoxicity test, the conjugate was about 3-10 times more cytotoxic against the antibody-reactive human T lymphocyte leukemia CEM cells than was free MMC or the mixture of HI30 and MMC [IC50 of the MMC equivalent (microgram/ml) was 0.4147, 2.212, 2.171, respectively] and was less cytotoxic against the antibody-nonreactive L1210 cells (IC50 were 1.311, 0.8683, 0.7308, respectively). The selective cytotoxicity was also confirmed by competitive inhibition with free antibody, showing a dependence on antibody binding of the target cell surface antigen. There was no detectable free MMC released from HI30-Dex-MMC conjugate stored at 4 degrees C for over one month as measured by chromatography on a Sephadex G-25 column.

[Pharmacological study of Rubus parvifolius L]

Aqueous extracts of Rubus parvifolius have been proved useful in shortening bleeding time and coagulation time in mice, shortening euglobulinlysis time in rabbits, inhibiting platelet thrombosis in rabbits in vivo, Rubus parvifolius increasing coronary flow in isolated rat heart, preventing rats from pituitrin induced changes of ECG and Rubus parvifolius increasing the tolerance of mice to hypoxia. The toxicity of Rubus parvifolius is small.

New Taxanes from Taxus chinensis

Two new taxane diterpenes, decinnamoyltaxagifine ( 3) and decinnanioyltaxagifine acetate ( 2), have been isolated from the leaves and stems of TAXUS CHINENSIS. Their structures were elucidated by spectroscopic methods. Their (13)C-NMR chemical shifts were assigned.

Glycosphingolipids of human myometrium and endometrium and their changes during the menstrual cycle, pregnancy and ageing

The glycolipid composition of human myometrium and endometrium was examined at various stages of maturation and reproduction. The major neutral glycolipids of both myometrium and endometrium were identified by high-performance thin-layer chromatography as globo-series glycolipids, Gb3 and Gb4. The major acidic glycolipids (gangliosides) were identified similarly as GM3 and GD3, with lesser amounts of GM1, GD1a, and GT1b. During pregnancy, GD3 expression declined in both myometrium and endometrium, whereas GM3 expression increased. Reciprocal changes in GM3/GD3 expression were mirrored by appropriate changes in the glycosyltransferases required for their synthesis; alpha 2----3sialyltransferase activity increased approximately 3-fold during pregnancy, while alpha 2----8sialyltransferase activity declined to about 20%. The results focus attention on the glycolipids of uterine tissues, their regulation, and their possible role in reproduction and fertility.

Clinical, biochemical, and neuropathologic findings following transplantation of adrenal medulla to the caudate nucleus for treatment of Parkinson's disease

We transplanted autologous adrenal medullary tissue into the caudate nucleus of 3 patients with advanced Parkinson's disease. The 1st patient, a 59-year-old man with parkinsonian symptoms for 15 years, had mild improvement in his motor functioning after the operation. However, his postoperative course was characterized by prolonged drowsiness and complex visual hallucinations. The patient died suddenly 8 months after the transplant, and an autopsy revealed coronary atherosclerosis. Examination of the graft site showed necrotic adrenal medullary tissue surrounded by inflammatory cells. The 2nd patient, a 50-year-old man with a 21-year history of parkinsonian symptoms, improved the most after the procedure. The 3rd patient, a 43-year-old man with 12 years of parkinsonian symptoms, had mild improvement in his motor functioning. CSF homovanillic acid increased postoperatively in the 3 patients, but then returned to preoperative levels in all except the 2nd patient. The anatomic, neurochemical, and physiologic basis for the modest clinical improvement shown in these patients is not yet understood.

Purification and characterization of a 43-kDa transcription factor required for rat somatostatin gene expression

A 43-kDa DNA binding protein which recognizes the TGACGTCA element of the rat somatostatin promoter has been purified from rat brain. Purification of the protein involved initial separation of three sequence-specific binding activities, b1-b3, from each other using DEAE-Sepharose chromatography. The protein corresponding to the b2 complex was further purified to apparent homogeneity by two cycles of sequence-specific DNA affinity chromatography, yielding a single species with an apparent mass of 43,000 daltons on a silver-stained polyacrylamide gel. Sequence-specific DNA binding of this purified protein was demonstrated by Southwestern blotting, renaturation, and DNase I footprinting studies. The 43-kDa protein was phosphorylated on serine residue(s) by the catalytic subunit of cAMP-dependent protein kinase, as shown by phosphoamino acid analysis. Furthermore, the purified protein specifically stimulated transcription from the rat somatostatin promoter in an in vitro transcription system. These results indicate that this 43-kDa protein is a transcription factor required for somatostatin gene expression.

Three sequence-specific DNA-protein complexes are formed with the same promoter element essential for expression of the rat somatostatin gene

We identified three sequence-specific DNA-protein complexes which are formed after in vitro binding of nuclear extracts, derived from neuronal (CA-77, rat brain) or non-neuronal (HeLa) cells, to positions -70 to -29 of the rat somatostatin promoter. The protein(s) responsible for the formation of the three sequence-specific complexes was fractionated from rat brain whole cell extracts by DEAE-Sepharose chromatography. The critical contact residues of the factor(s) in each complex, as determined by methylation interference analyses, are located within positions -59 to -35, which is protected from DNase I digestion; these include the G residues of a TGACGTCA consensus also found in the cAMP-responsive human enkephalin (positions -105 to -76) and E1A-inducible adenovirus type 5 E3 (positions -72 to -42) promoters. Competition assays with these heterologous promoters reveal that the factor(s) of each complex displays approximately 50-fold greater affinity for the somatostatin promoter-binding site. Synthetic oligonucleotides spanning positions -70 to -29 of the somatostatin promoter and containing single-base substitutions of the G residues in the TGACGTCA consensus were utilized in competition assays. The G residues located in the center of the module are the most critical determinants in the formation of the three sequence-specific complexes. Deletions disrupting the TGACGTCA consensus abolish not only formation of the three complexes in vitro but also expression of the somatostatin promoter in vivo, suggesting that formation of one or more of these complexes is essential for transcription of the rat somatostatin gene.

Monitoring the arbitrary thickness of optical thin films and their error simulation: a method

This paper was the method of monitoring the absolute value for film layer transmittance to monitor the thickness of optical thin film. For this purpose, a 2S3G double-color three-path monitoring apparatus was built. Simulation analyses of monitoring errors have been conducted and a flow diagram is given. Using this method and apparatus, 9-, 15-, and 23-layer broadband neutral dichroic filters, cold light coatings, edge filters, and polarizers have been plated; good reproducibility and satisfactory results have been obtained, thereby achieving the preparation of the non-lambda/4 multilayer system

Preliminary studies on a lectin on the surface of adipocytes

A lectin-like component on the surface of porcine adipocytes was identified, chiefly by means of the cell adhesion and hemagglutination assays. This component, named porcine adipocyte lectin (PAL), was isolated with Triton X-100 solubilization followed by affinity chromatography. By SDS-polyacrylamide gel electrophoresis, two hands of PAL stained with Coomassie blue were revealed with the apparent molecular weights of 112,000 and 89,000. Moreover, the glycoprotein nature of PAL, was demonstrated by periodic-Schiff reagent staining. PAL was able to recognize maltose, mannose and mannan and glycoproteins with analogous sugar structure in the presence of Ca. By the finding that adipocytes in suspension could be aggregated by adding PAL, the hypothesis was advanced that PAL may be involved in the recognition and adhesion of adipocytes in vivo.