Transcription of Epstein-Barr virus-encoded nuclear antigen 1 promoter Qp is repressed by transforming growth factor-beta via Smad4 binding element in human BL cells

In Epstein-Barr virus (EBV)-infected BL cells, the oncogenic EBV-encoded nuclear antigen 1 (EBNA 1) gene is directed from the latent promoter Qp. Yeast one-hybrid screen analysis using the -50 to -37 sequence of Qp as the bait was carried out to identify transcriptional factors that may control Qp activity. Results showed that Smad4 binds the -50 to -37 sequence of Qp, indicating that this promoter is potentially regulated by TGF-beta. The association of Smad4 with Qp was further confirmed by supershift of EMSA complexes using Smad4-specific antibody. The transfection of a Qp reporter construct in two EBV(+) BL cell lines, Rael and WW2, showed that Qp activity is repressed in response to the TGF-beta treatment. This repression involves the interaction of a Smad3/Smad4 complex and the transcriptional repressor TGIF, as determined by cotransfection assay and coimmunoprecipitation analysis. Results suggest that TGF-beta may transcriptionally repress Qp through the Smad4-binding site in human BL cells.

Stress analysis of different wall thicknesses of implant fixture with various boundary levels

The aim of the present work is to develop 3D finite element models of implant fixture with different wall thicknesses to predict maximum stress concentration sites and distribution contours after loading. A maximum lateral force of 150 N was applied to simulate horizontal occlusal forces. When the fixtures were constrained to simulate different boundary levels, the maximum equivalent stress (max EQV) was always located at the implant-bone interface. Max EQV increased when the wall thickness or boundary level was reduced to a certain extent. The fixture with a wall thickness of 0.97 mm demonstrated the smallest stress increase ratio when the boundary level was lowered. Our results indicated that both wall thickness and the boundary level played important roles in maintaining a well-distributed stress level within the fixture. The stress concentration decreased when the fixture wall became thicker, however, this effect was less significant when the surrounding bone level was reduced.

Novel antihyperglycemic terpenoid-quinones from Pycnanthus angolensis

Two new compounds, pycnanthuquinone A (1) and pycnanthuquinone B (2), were isolated from leaves and stems of the African plant, Pycnanthus angolensis (Welw.) Warb (Myristicaceae), by bioassay-guided fractionation of an ethanolic extract using a diabetic mouse model. Pycnanthuquinones A and B are the first representatives of a novel terpenoid-type quinone skeleton, and both compounds possess significant antihyperglycemic activity.

Anaerobic stability of aqueous physostigmine solution

The anaerobic stability of physostigmine was studied in this report. Physostigmine and two important degradants, eseroline and rubreserine, were identified by a high-performance liquid chromatography (HPLC) system using a photodiode array detector and a UV detector at the retention times of 12.4, 9.2, and 7.9 min. Under anaerobic treatment, the minimum degradation rate constant was found at pH 3.4, evaluating from pH-rate profiles at 45 degrees C, 55 degrees C, and 70 degrees C with the pH range 2.4-6.8. The degradation of physostigmine was suggested as specific acid-base catalysis. Anaerobic activation energies of KH, K(OH), and Kobs were 9.4, 8.3, and 17.9 kcal/mol, respectively. The ratios of observed aerobic and anaerobic rate constants were 2-33 at 88 degrees C, which had a trend to increase ratios as pH increased in the range 2.4-5.2. The shelf life of physostigmine solution was estimated to be 4 years at room temperature under anaerobic conditions at pH 3.4.

Gene expression profiling in the human hypothalamus-pituitary-adrenal axis and full-length cDNA cloning

The primary neuroendocrine interface, hypothalamus and pituitary, together with adrenals, constitute the major axis responsible for the maintenance of homeostasis and the response to the perturbations in the environment. The gene expression profiling in the human hypothalamus-pituitary-adrenal axis was catalogued by generating a large amount of expressed sequence tags (ESTs), followed by bioinformatics analysis (http://www.chgc.sh.cn/ database). Totally, 25,973 sequences of good quality were obtained from 31,130 clones (83.4%) from cDNA libraries of the hypothalamus, pituitary, and adrenal glands. After eliminating 5,347 sequences corresponding to repetitive elements and mtDNA, 20,626 ESTs could be assembled into 9, 175 clusters (3,979, 3,074, and 4,116 clusters in hypothalamus, pituitary, and adrenal glands, respectively) when overlapping ESTs were integrated. Of these clusters, 2,777 (30.3%) corresponded to known genes, 4,165 (44.8%) to dbESTs, and 2,233 (24.3%) to novel ESTs. The gene expression profiles reflected well the functional characteristics of the three levels in the hypothalamus-pituitary-adrenal axis, because most of the 20 genes with highest expression showed statistical difference in terms of tissue distribution, including a group of tissue-specific functional markers. Meanwhile, some findings were made with regard to the physiology of the axis, and 200 full-length cDNAs of novel genes were cloned and sequenced. All of these data may contribute to the understanding of the neuroendocrine regulation of human life.

Identification of NY-ESO-1 peptide analogues capable of improved stimulation of tumor-reactive CTL

Expression of NY-ESO-1 in a high proportion of different human tumors makes this protein a very attractive vaccine target. NY-ESO-1 peptides, recognized by HLA-A2-restricted CTL, have recently been described. However, it remains unclear how efficiently tumors generate these epitopes, and whether peptide analogues can be used for optimal expansion and activation of NY-ESO-1-specific HLA-A2-restricted CTL. By generating unique CTL clones, we demonstrate that NY-ESO-1-positive tumor cells are efficiently killed by HLA-A2-restricted CTL specific for the peptide epitope NY-ESO-1 157-165. Presentation of this epitope is not affected by the presence or absence of the proteasome subunits low molecular proteins 2 and 7 and is not blocked by proteasome inhibitors, while it is impaired in the TAP-deficient cell line LBL 721.174. NY-ESO-1 157-165 peptide analogues were compared for their antigenicity and immunogenicity using PBL from melanoma patients. Three peptides, containing the carboxyl-terminal cysteine substituted for either valine, isoleucine, or leucine, were recognized at least 100 times more efficiently than the wild-type peptide by specific CTL. Peptide analogues were capable of stimulating the expansion of NY-ESO-1-specific CTL from PBL of melanoma patients much more efficiently than wild-type peptide. These findings define the processing requirements for the generation of the NY-ESO-1 157-165 epitope. Identification of highly antigenic NY-ESO-1 peptide analogues may be important for the development of vaccines capable of expanding NY-ESO-1-specific CTL in cancer patients.

Phase I study in melanoma patients of a vaccine with peptide-pulsed dendritic cells generated in vitro from CD34(+) hematopoietic progenitor cells

Dendritic cells (DCs) are professional antigen-presenting cells (APCs) that can be used for vaccination purposes, to induce a specific T-cell response in vivo against melanoma-associated antigens. We have shown that the sequential use of early-acting hematopoietic growth factors, stem cell factor, IL-3 and IL-6, followed by differentiation with IL-4 and granulocyte-macrophage colony-stimulating factor allows the in vitro generation of large numbers of immature DCs from CD34(+) peripheral blood progenitor cells. Maturation to interdigitating DCs could specifically be induced within 24 hr by addition of TNF-alpha. Here, we report on a phase I clinical vaccination trial in melanoma patients using peptide-pulsed DCs. Fourteen HLA-A1(+) or HLA-A2(+) patients received at least 4 i.v. infusions of 5 x 10(6) to 5 x 10(7) DCs pulsed with a pool of peptides including either MAGE-1, MAGE-3 (HLA-A1) or Melan-A, gp100, tyrosinase (HLA-A2), depending on the HLA haplotype. A total of 83 vaccinations were performed. Clinical side effects were mild and consisted of low-grade fever (WHO grade I-II). Clinical and immunological responses consisted of anti-tumor responses in 2 patients, increased melanoma peptide-specific delayed-type hypersensitivity reactions in 4 patients, significant expansion of Melan-A- and gp100-specific cytotoxic T lymphocytes in the peripheral blood lymphocytes of 1 patient after vaccination and development of vitiligo in another HLA-A2(+) patient. Our data indicate that the vaccination of peptide-pulsed DCs is capable of inducing clinical and systemic tumor-specific immune responses without provoking major side effects.

[A study on the chemical components of essential oil of oak moss concrete by gas chromatography/mass spectrometry]

The essential oil of oak moss concrete was extracted by volatile oil content equipment. The chemical compositions and their relative contents were analyzed by GC and GC/MS. A Supelco-5 fused silica capillary column (30 m x 0.32 mm i.d.; 0.25 micron thickness) and a flame ionization detector (FID) were employed in GC analysis. The temperature program included temperature increase of 4 degrees C/min from 50 degrees C to 250 degrees C, and a 10 min isothermal period at 250 degrees C. Mass spectra were obtained by electron impact at 70 eV and a source temperature of 170 degrees C. Twenty-four volatile compounds of oak mass concrete were identified, which comprised more than 83% of volatile fraction. The major components were diethyl phthalate, alpha-terpineol, cedrane and linalool.

Phase I study in melanoma patients of a vaccine with peptide-pulsed dendritic cells generated in vitro from CD34(+) hematopoietic progenitor cells

Dendritic cells (DCs) are professional antigen-presenting cells (APCs) that can be used for vaccination purposes, to induce a specific T-cell response in vivo against melanoma-associated antigens. We have shown that the sequential use of early-acting hematopoietic growth factors, stem cell factor, IL-3 and IL-6, followed by differentiation with IL-4 and granulocyte-macrophage colony-stimulating factor allows the in vitro generation of large numbers of immature DCs from CD34(+) peripheral blood progenitor cells. Maturation to interdigitating DCs could specifically be induced within 24 hr by addition of TNF-alpha. Here, we report on a phase I clinical vaccination trial in melanoma patients using peptide-pulsed DCs. Fourteen HLA-A1(+) or HLA-A2(+) patients received at least 4 i.v. infusions of 5 x 10(6) to 5 x 10(7) DCs pulsed with a pool of peptides including either MAGE-1, MAGE-3 (HLA-A1) or Melan-A, gp100, tyrosinase (HLA-A2), depending on the HLA haplotype. A total of 83 vaccinations were performed. Clinical side effects were mild and consisted of low-grade fever (WHO grade I-II). Clinical and immunological responses consisted of anti-tumor responses in 2 patients, increased melanoma peptide-specific delayed-type hypersensitivity reactions in 4 patients, significant expansion of Melan-A- and gp100-specific cytotoxic T lymphocytes in the peripheral blood lymphocytes of 1 patient after vaccination and development of vitiligo in another HLA-A2(+) patient. Our data indicate that the vaccination of peptide-pulsed DCs is capable of inducing clinical and systemic tumor-specific immune responses without provoking major side effects.

Generation and purification of CD8+ melan-A-specific cytotoxic T lymphocytes for adoptive transfer in tumor immunotherapy

Tumor antigens that might serve as potential targets for adoptive T-cell therapy have been defined in different tumor entities, especially in malignant melanoma. To generate conditions to induce primary T-cell responses against different HLA-A*0201-restricted melanoma peptides and to allow further expansion of peptide-specific T cells for adoptive transfer, CD8+-purified T cells from healthy donors were stimulated with Melan-A-pulsed autologous dendritic cells. Dendritic cells were generated in vitro from monocytes with granulocyte macrophage colony-stimulating factor, interleukin-4, and transforming growth factor-beta1. After 3-4 weekly stimulation cycles with Melan-A-pulsed DCs, we were able to induce a strong peptide-specific CTL response in vitro. MHC-peptide tetramer staining revealed a frequency of up to 3.5% CD8+/Melan-A+ T cells. Additional antigen-independent expansion with anti-CD3/anti-CD28 monoclonal antibodies together with interleukin-2 gave rise to 600-fold expansion of CD8+ CTLs that maintained Melan-A specificity and were able to efficiently lyse Melan-A-expressing melanoma cells. To enrich antigen-specific T cells in vitro, we used a recently established technology for analysis and sorting of live cells according to secreted cytokines. In the present study, we demonstrated that Melan-A-specific T cells can be purified by magnetic separation according to secreted IFN-gamma. These cells revealed a very potent monospecific CTL response, even at low E:T ratios, against Melan-A-pulsed and Melan-A-expressing target cells. Altogether, our study demonstrated that we have developed an efficient method for generating large numbers of peptide-specific T cells in vitro that may be used for adoptive T-cell transfer in tumor immunotherapy.

Formation of charge-transfer complexes from neutral bis(porphyrin) sandwiches

Lanthanide(III) bis(porphyrin) sandwich complexes of octaethyltetraazaporphyrin (OETAP) were synthesized and characterized by UV-vis, IR, and NMR spectroscopies. Cyclic voltammetry results indicate that these neutral sandwich complexes are very easily reduced. Charge-transfer reactions were performed in solution with Ln-(OETAP)2 sandwiches and zirconium(IV) bis(porphyrin) sandwiches. The lanthanide sandwiches partially oxidize the zirconium sandwiches in solution, and a solvent dependence of the charge-transfer reaction was observed. The solid-state properties of these charge-transfer materials were also studied. Magnetic susceptibility results suggest weak intermolecular interactions between the sandwiches. The conductivities of the charge-transfer species are greatly improved relative to those of the insulating undoped sandwiches, but the conductivities are in the lower semiconducting region. The low conductivity values are thought to be due to poor intermolecular overlap.

Secondary structure of vertebrate telomerase RNA

Telomerase is a ribonucleoprotein enzyme that maintains telomere length by adding telomeric sequence repeats onto chromosome ends. The essential RNA component of telomerase provides the template for telomeric repeat synthesis. To determine the secondary structure of vertebrate telomerase RNA, 32 new telomerase RNA genes were cloned and sequenced from a variety of vertebrate species including 18 mammals, 2 birds, 1 reptile, 7 amphibians, and 4 fishes. Using phylogenetic comparative analysis, we propose a secondary structure that contains four structural domains conserved in all vertebrates. Ten helical regions of the RNA are universally conserved while other regions vary significantly in length and sequence between different classes of vertebrates. The proposed vertebrate telomerase RNA structure displays a strikingly similar topology to the previously determined ciliate telomerase RNA structure, implying an evolutionary conservation of the global architecture of telomerase RNA.

When is hilar uptake of 67Ga-citrate indicative of residual disease after CHOP chemotherapy?

The purpose of this study was to evaluate the prevalence and characterize the patterns of hilar uptake (HU) on 67Ga-citrate imaging after cyclophosphamide, doxorubicin, vincristine, and prednisone (CHOP) chemotherapy regimens for non-Hodgkin's lymphoma (NHL), to differentiate hilar lymphoma (HL) from HU of benign etiology.

METHODS

A total of 930 studies (698 planar, 232 thoracic SPECT) was reviewed retrospectively in 100 NHL patients (29 low-grade, 60 intermediate-grade, and 11 high-grade) treated with CHOP and followed up longitudinally with serial gallium studies (planar: median, 7; range, 3-16 studies in 100 patients; SPECT: median, 1; range, 0-11 studies in 72 patients) over a median duration of 36 mo (range, 6-112 mo) from diagnosis. Clinical outcome and size changes over time on correlative CT and/or radiographs were used to evaluate benign versus malignant changes within the hila.

RESULTS

HU after CHOP was present in 79% of patients (90% confidence interval [CI], 71%-85%), with 33% showing HU on SPECT alone. Once present, HU persisted for a median of 27 mo (range, 2-84 mo) from onset. The prevalence of HU and HL at various time points was as follows: baseline HU, 52% with HL 60%; mid-CHOP HU, 59% with HL2%; post-CHOP HU, 52% with HL6%; follow-up HU, 76% with HL 9%. HU of benign etiology was not significantly correlated with CHOP dosage. HU was symmetric in 90% of patients (90% CI, 82%-95%) and less intense than the original disease in 89% of patients (90% CI, 80%-95%), and these features were highly predictive of benign etiology (negative predictive value [NPV], 98.6% if symmetric; NPV, 96.5% if less than original disease; NPV, 100% if both present). Asymmetric HU equal in intensity to the original disease, however, was highly predictive of HL (positive predictive value [PPV], 87.5% if asymmetric; PPV, 85.7% if equal to original disease; PPV, 100% if both present).

CONCLUSION

HU after CHOP is common (overall incidence, 79%), often seen only on SPECT, and most likely of benign etiology when symmetric and less intense than the original disease. Asymmetric HU that equals the intensity of the original disease, however, is a possible indicator for HL.

Atrial fibrillation and tumor emboli as manifestations of metastatic leiomyosarcoma to the heart and lung

Leiomyosarcoma is a malignant tumor of the smooth muscle that rarely occurs in the gastrointestinal tract. High-grade leiomyosarcomas of the rectosigmoid usually metastasize to the liver and lungs. Although it is unusual, metastases to the heart have been reported. When this occurs, the metastatic tumor usually seeds in the right atrium and pulmonary artery. We report on and discuss a patient who had atrial fibrillation, peripheral emboli, and thrombocytopenia resulting from a low-grade rectosigmoid leiomyosarcoma metastatic to the pulmonary vein and left atrium. Atrial fibrillation is not a common manifestation of malignant neoplasms that have spread to the heart. Surgical removal of the tumor terminated the arrhythmia and thrombocytopenia.

Synthesis and analytical properties of a novel columnar metallomesogenic polymer

A metallomesogenic side-chain polymer with copper carboxylato discotic units in stacks prepared by covalent bonding of 14-pentadecenoic acid, stearic acid and poly(methylhydrosiloxane) is described. The physico-chemical and thermal properties of both monomeric and polymeric metallomesogens were determined by elemental analysis, IR, polarizing optical microscopy, thermal gravimetric analysis and differential scanning calorimetry. The polymeric states showed a discotic lamellar phase at 50-95 degrees C and an ordered discotic hexagonal phase at 95-200 degrees C. By dynamic coating, the metallomesogenic polymer was crosslinked to the capillary wall via benzoyl peroxide. The wall-coated capillary columns (15 m x 0.25 mm I.D.) were used for the separation of phenols. Factors affecting the retention and the sample selectivity were examined. Van 't Hoff plots as a function of temperature indicated that phase transitions were occurring. Thermodynamic properties of the analytes in this system were also studied. For the determination of a mixture of 3-aminophenol, 2-chlorophenol, 2-nitrophenol, 4-nitrophenol, o-methylphenol, m-methylphenol, p-methylphenol, 2,4-dichlorophenol, 2,4-dimethylphenol, 2,4-dinitrophenol, 2,4,6-trichlorophenol, 2,4,6-trimethylphenol, 4-bromophenol, 3-methyl-4-chlorophenol, pentachlorophenol, and unsubstituted phenol, the calibration graphs for most phenols were linear over the range of 10-1000 microg ml(-1) and the mass detection limits were in the ng range based on three times standard deviation of seven measurements of the lowest peak that could be detected.

Randomized clinical trial of urokinase versus heparin in unstable angina

The aim of this study was to evaluate the clinical effect of urokinase (UK) in unstable angina (UA). This study was a multicenter, single-blind, heparin-controlled, randomized clinical trial. Entry criteria was that effort angina was significantly aggravated within 96 hours and angina attack at rest within 24 hours. In addition to the control group, thrombolytic therapy was divided into two groups according to the dose of UK. The high-dose group was 18,000 IU/kg, and the total dose was no more than 1.5 million IU (no bolus of heparin in this dose). The low-dose group was 14,000 IU/kg, and the total dose was no more than 1 million IU. All patients were treated by aspirin 300 mg/day and heparin 3000 U IV bolus before thrombolytic therapy (except for the high-dose group), then subcutaneous heparin 7,500 U q12h. The primary endpoint for the comparison between the thrombolytic and control groups was death and AMI (cardiac event) within 30 days of enrollment. Five hundred and fifty-six patients with UA were selected, and 272 and 284 patients were enrolled in thrombolytic group and control groups, respectively. The 30-day incidence of cardiac events was a little higher, but not significantly, in the thrombolytic group than in the control group (7.0% vs. 5.3%, ns), but the rate for cardiac events was much lower in the low-dose UK group than in the high-dose UK group. The difference was significant (3.3% vs. 10.0%, P < 0.05). Even if the rate was also lower than in the control group, this difference was not significant (3.3% vs. 5.3%, P > 0.05). The time interval between enrollment and the AMIs was quite different in these two groups. The majority of AMIs (73.7%) occurred within 24 hours, including 37% of AMIs that occurred within 2 hours after the beginning of thrombolytic therapy in the UK group. However, only small number of AMIs (20%) occurred within 24 hours of enrollment in the control group. The increase in AMI risk on the first day of thrombolytic therapy in this study might be closely related to thrombolysis and to the lack of strong antithrombin therapy. The risk of AMI might be remarkably reduced by using low-dose UK in combination with antithrombin therapy before thrombolytic therapy.

Role of synaptic vesicle proton gradient and protein phosphorylation on ATP-mediated activation of membrane-associated brain glutamate decarboxylase

Previously, we have shown that the soluble form of brain glutamic acid decarboxylase (GAD) is inhibited by ATP through protein phosphorylation and is activated by calcineurin-mediated protein dephosphorylation (Bao, J., Cheung, W. Y., and Wu, J. Y. (1995) J. Biol. Chem. 270, 6464-6467). Here we report that the membrane-associated form of GAD (MGAD) is greatly activated by ATP, whereas adenosine 5'-[beta,gamma-imido]triphosphate (AMP-PNP), a non-hydrolyzable ATP analog, has no effect on MGAD activity. ATP activation of MGAD is abolished by conditions that disrupt the proton gradient of synaptic vesicles, e.g. the presence of vesicular proton pump inhibitor, bafilomycin A1, the protonophore carbonyl cyanide m-chorophenylhydrazone or the ionophore gramicidin, indicating that the synaptic vesicle proton gradient is essential in ATP activation of MGAD. Furthermore, direct incorporation of (32)P from [gamma-(32)P]ATP into MGAD has been demonstrated. In addition, MGAD (presumably GAD65, since it is recognized by specific monoclonal antibody, GAD6, as well as specific anti-GAD65) has been reported to be associated with synaptic vesicles. Based on these results, a model linking gamma-aminobutyric acid (GABA) synthesis by MGAD to GABA packaging into synaptic vesicles by proton gradient-mediated GABA transport is presented. Activation of MGAD by phosphorylation appears to be mediated by a vesicular protein kinase that is controlled by the vesicular proton gradient.

Possible experimental measure theory for the XXX-Heisenberg chain

Raising and lowering operators for the XXX-Heisenberg chain are derived explicitly; as a result the dipole moment operator is established. Based on the dipole transition mechanism in an external time-dependent magnetic field, we propose a possible experimental measure theory to detect the energy spectrum of the spin chain.

Cutting edge: rapid cloning of tumor-specific CTL suitable for adoptive immunotherapy of melanoma

Adoptive immunotherapy using CTL has provided some clinical benefit to patients with metastatic melanoma. Use of cloned CTL of known specificity might improve clinical effect, but technical difficulties have limited exploration of this possibility. We have used fluorescence-driven cell sorting to clone tumor-specific CTL after staining with tetrameric MHC class I/peptide complexes. CTL specific for the melanoma Ags melan-A, tyrosinase, and MAGE3 were cloned from the peripheral blood, tumor-infiltrated lymph nodes, and skin metastases of five patients. Clones were isolated and characterized in as little as 6 weeks, much faster than is possible with previous techniques. We show that these CTL clones express markers compatible with immunotherapeutic use in melanoma, including the cutaneous lymphocyte Ag, which is associated with homing to skin.

Adenovirus-mediated overexpression of uncoupling protein-2 in pancreatic islets of Zucker diabetic rats increases oxidative activity and improves beta-cell function

The discovery of uncoupling protein (UCP)-2, a ubiquitously expressed protein homologous to UCP-1, has raised the possibility that energy balance of cells might be regulated in tissues other than brown adipocytes. In normal pancreatic islets, UCP-2 is upregulated by leptin and is low in leptin-resistant islets of ZDF rats. To determine whether UCP-2 does, in fact, have uncoupling activity and, if so, whether such activity would favorably influence the abnormalities in leptin-unresponsive UCP-2-underexpressing islets of diabetic ZDF rats, we transferred the UCP-2 gene to the islets of diabetic ZDF rats and lean (+/+) ZDF control rats. Although ATP was reduced by 23% in both groups of islets, the ATP:ADP ratio increased by 42 and 141%, respectively. [3H]palmitate oxidation was increased by 50%, and [3H]glucose oxidation was 42-63% higher. Preproinsulin mRNA was 2.9-fold above control levels, and glucose-stimulated insulin secretion, which was negligible in control ZDF rat islets, was improved in UCP-2-overexpressing islets. The high fat content of the islets was not reduced, however. We conclude that UCP-2 has uncoupling function when overexpressed in leptin-insensitive islets and that its overexpression corrects the underexpression of the insulin gene and ameliorates glucose-stimulated insulin secretion, possibly by increasing the ATP:ADP ratio.

Isolation and unambiguous synthesis of cryptolepinone: An oxidation artifact of cryptolepine

Cryptolepinone (3) was isolated as an artifact of extraction from Cryptolepis sanguinolenta. Previously, this compound had been identified as the natural products hydroxycryptolepine (2) and 3. Synthesis via an unambiguous pathway has confirmed the structure of cryptolepinone. Spectroscopic studies in various solvents have shown that the natural product artifact or its synthetic equivalent can exist in the keto (cryptolepinone) or enol (hydroxycryptolepine) form.

Ex vivo staining of metastatic lymph nodes by class I major histocompatibility complex tetramers reveals high numbers of antigen-experienced tumor-specific cytolytic T lymphocytes

Characterization of cytolytic T lymphocyte (CTL) responses to tumor antigens has been impeded by a lack of direct assays of CTL activity. We have synthesized reagents ("tetramers") that specifically stain CTLs recognizing melanoma antigens. Tetramer staining of tumor-infiltrated lymph nodes ex vivo revealed high frequencies of tumor-specific CTLs which were antigen-experienced by surface phenotype. In vitro culture of lymph node cells with cytokines resulted in very large expansions of tumor-specific CTLs that were dependent on the presence of tumor cells in the lymph nodes. Tetramer-guided sorting by flow cytometer allowed isolation of melanoma-specific CTLs and confirmation of their specificity and their ability to lyse autologous tumor cells. Our results demonstrate the value of these novel reagents for monitoring tumor-specific CTL responses and for generating CTLs for adoptive immunotherapy. These data also indicate that strong CTL responses to melanoma often occur in vivo, and that the reactive CTLs have substantial proliferative and tumoricidal potential.

Accumulation of alpha-keto acids as essential components in cyanide assimilation by Pseudomonas fluorescens NCIMB 11764

Pyruvate (Pyr) and alpha-ketoglutarate (alphaKg) accumulated when cells of Pseudomonas fluorescens NCIMB 11764 were cultivated on growth-limiting amounts of ammonia or cyanide and were shown to be responsible for the nonenzymatic removal of cyanide from culture fluids as previously reported (J.-L. Chen and D. A. Kunz, FEMS Microbiol. Lett. 156:61-67, 1997). The accumulation of keto acids in the medium paralleled the increase in cyanide-removing activity, with maximal activity (760 micromol of cyanide removed min-1 ml of culture fluid-1) being recovered after 72 h of cultivation, at which time the keto acid concentration was 23 mM. The reaction products that formed between the biologically formed keto acids and cyanide were unambiguously identified as the corresponding cyanohydrins by 13C nuclear magnetic resonance spectroscopy. Both the Pyr and alpha-Kg cyanohydrins were further metabolized by cell extracts and served also as nitrogenous growth substrates. Radiotracer experiments showed that CO2 (and NH3) were formed as enzymatic conversion products, with the keto acid being regenerated as a coproduct. Evidence that the enzyme responsible for cyanohydrin conversion is cyanide oxygenase, which was shown previously to be required for cyanide utilization, is based on results showing that (i) conversion occurred only when extracts were induced for the enzyme, (ii) conversion was oxygen and reduced-pyridine nucleotide dependent, and (iii) a mutant strain defective in the enzyme was unable to grow when it was provided with the cyanohydrins as a growth substrate. Pyr and alphaKg were further shown to protect cells from cyanide poisoning, and excretion of the two was directly linked to utilization of cyanide as a growth substrate. The results provide the basis for a new mechanism of cyanide detoxification and assimilation in which keto acids play an essential role.

New iridoids from the medicinal plant Barleria prionitis with potent activity against respiratory syncytial virus

Two new iridoid glycosides (1 and 2), together with the known compounds barlerin (3) and verbascoside (4), were isolated from Barleria prionitis. The new iridoid glycosides were determined to be 6-O-trans-p-coumaroyl-8-O-acetylshanzhiside methyl ester (1) and its cis isomer (2) by using spectroscopic, especially 2D NMR, data. A 3:1 mixture of 1 and 2 was shown to have potent in vitro activity against respiratory syncytial virus (EC50 2.46 microgram/mL, IC50 42.2 microgram/mL).

High frequency of skin-homing melanocyte-specific cytotoxic T lymphocytes in autoimmune vitiligo

Vitiligo is an autoimmune condition characterized by loss of epidermal melanocytes. Using tetrameric complexes of human histocompatibility leukocyte antigen (HLA) class I to identify antigen-specific T cells ex vivo, we observed high frequencies of circulating MelanA-specific, A*0201-restricted cytotoxic T lymphocytes (A2-MelanA tetramer+ CTLs) in seven of nine HLA-A*0201-positive individuals with vitiligo. Isolated A2-MelanA tetramer+ CTLs were able to lyse A*0201-matched melanoma cells in vitro and their frequency ex vivo correlated with extent of disease. In contrast, no A2-MelanA tetramer+ CTL could be identified ex vivo in all four A*0201-negative vitiligo patients or five of six A*0201-positive asymptomatic controls. Finally, we observed that the A2-MelanA tetramer+ CTLs isolated from vitiligo patients expressed high levels of the skin homing receptor, cutaneous lymphocyte-associated antigen, which was absent from the CTLs seen in the single A*0201-positive normal control. These data are consistent with a role of skin-homing autoreactive melanocyte-specific CTLs in causing the destruction of melanocytes seen in autoimmune vitiligo. Lack of homing receptors on the surface of autoreactive CTLs could be a mechanism to control peripheral tolerance in vivo.

Two modes of transvection: enhancer action in trans and bypass of a chromatin insulator in cis

Ed Lewis introduced the term "transvection" in 1954 to describe mechanisms that can cause the expression of a gene to be sensitive to the proximity of its homologue. Transvection since has been reported at an increasing number of loci in Drosophila, where homologous chromosomes are paired in somatic tissues, as well as at loci in other organisms. At the Drosophila yellow gene, transvection can explain intragenic complementation involving the yellow2 allele (y2). Here, transvection was proposed to occur by enhancers of one allele acting in trans on the promoter of a paired homologue. In this report, we describe two yellow alleles that strengthen this model and reveal an unexpected, second mechanism for transvection. Data suggest that, in addition to enhancer action in trans, transvection can occur by enhancer bypass of a chromatin insulator in cis. We propose that bypass results from the topology of paired genes. Finally, transvection at yellow can occur in genotypes not involving y2, implying that it is a feature of yellow itself and not an attribute of one particular allele.

Effects of pH, electric current, and enzyme inhibitors on iontophoresis of delta sleep-inducing peptide

Delta sleep-inducing peptide (DSIP), a peptide of nine amino acid residues, was used as a model drug to investigate the effects of pH, electric current, and enzyme inhibitors on the transdermal iontophoretic delivery of peptide drugs. DSIP was fairly stable in pH 4-9 buffer solutions but was cleaved by the skin enzymes during iontophoretic delivery. Enzyme inhibitors, such as o-phenanthroline, ethylene-diaminetetraacetic acid (EDTA), dilucine, and sodium deoxycholate, could inhibit the degradation of DSIP to a certain extent in the skin homogenate. Our results showed that metalloproteases were probably more important enzymes for DSIP hydrolysis. By using 0.2 mM o-phenanthroline in the iontophoretic delivery of DSIP at pH 4, we were able to significantly enhance the penetration of DSIP. The flux was about eight times as much as control (without o-phenanthroline) at pH 7.4.

Extravasation injury associated with low-dose dopamine

OBJECTIVE

To describe the occurrence of extravasation in two patients receiving low-dose dopamine infusions.

CASE SUMMARY

Intravenous dopamine was infused peripherally (in the antecubital fossa) to two patients in the cardiac intensive care unit in an attempt to enhance renal blood perfusion and urine output. Dopamine extravasation occurred in both patients while the low dose (< 3 micrograms/kg/min) was infused. Significant local tissue injury was observed in both patients.

DISCUSSION

Dopamine infusion can cause tissue ischemia or necrosis secondary to vasospasm and extravasation. Most of the case reports in the literature have occurred when relatively high doses of dopamine were infused. Only one reported extravasation-induced injury with low-dose dopamine. Although low-dose dopamine has a vasodilatory effect in selected tissues, high concentrations achieved locally as a result of extravasation can still cause severe vasoconstriction and ischemic tissue injury.

CONCLUSIONS

Low-dose dopamine therapy should be administered with similar precautions as high-dose dopamine. A central intravenous access should be placed for dopamine infusion whenever possible. If this approach is not feasible, dopamine should be infused only peripherally through a long intravenous catheter into a large vein. A 5-cm angiocatheter that is 20 gauge or larger is recommended for peripheral dopamine infusion in our institution. The infusion site should be inspected frequently for early detection of extravasation, and changed to a central or a peripherally inserted central catheter as soon as possible, especially in patients at high risk for extravasation.

Antiviral phenylpropanoid glycosides from the medicinal plant Markhamia lutea

Three new phenylpropanoid glycosides, named luteoside A (3), luteoside B (4), and luteoside C (5), were isolated together with the known compounds verbascoside (1) and isoverbascoside (2) from the roots of the medicinal plant Markhamia lutea. The structures of the new compounds were determined to be 1-O-(3, 4-dihydroxyphenyl)ethyl beta-D-apiofuranosyl(1-->2)-alpha-l-rhamnopyranosyl(1-->3)-4-O- caffeo yl-6-acetyl-beta-d-glucopyranoside, 1-O-(3,4-dihydroxyphenyl)ethyl beta-d-apiofuranosyl(1-->2)-alpha-l-rhamnopyranosyl(1-->3)-6-O- caffeo yl-beta-d-glucopyranoside, and 1-O-(3,4-dihydroxyphenyl)ethyl beta-D-apiofuranosyl(1-->2)-alpha-l-rhamnopyranosyl(1-->3)-6-O- ferulo yl-beta-d-glucopyranoside, respectively, on the basis of chemical and spectroscopic data. All five phenylpropanoid glycosides exhibited potent in vitro activity against respiratory syncytial virus.

Comparative photocross-linking analysis of the tertiary structures of Escherichia coli and Bacillus subtilis RNase P RNAs

Bacterial ribonuclease P contains a catalytic RNA subunit that cleaves precursor sequences from the 5' ends of pre-tRNAs. The RNase P RNAs from Bacillus subtilis and Escherichia coli each contain several unique secondary structural elements not present in the other. To understand better how these phylogenetically variable elements affect the global architecture of the ribozyme, photoaffinity cross-linking studies were carried out. Photolysis of photoagents attached at homologous sites in the two RNAs results in nearly identical cross-linking patterns, consistent with the homology of the RNAs and indicating that these RNAs contain a common, core tertiary structure. Distance constraints were used to derive tertiary structure models using a molecular mechanics-based modeling protocol. The resulting superimposition of large sets of equivalent models provides a low resolution (5-10 A) structure for each RNA. Comparison of these structure models shows that the conserved core helices occupy similar positions in space. Variably present helical elements that may play a role in global structural stability are found at the periphery of the core structure. The P5.1 and P15.1 helical elements, unique to the B.subtilis RNase P RNA, and the P6/16/17 helices, unique to the E.coli RNA, occupy similar positions in the structure models and, therefore, may have analogous structural function.

Therapeutic effect and pharmacokinetics of ketotifen transdermal delivery system

Ketotifen transdermal delivery systems were prepared using polyisobutylene, liquid paraffin, and fatty acid. In vitro skin penetration studies were conducted in Franz diffusion cells using excised porcine skin to determine the skin permeation rates of ketotifen patches. A trend of increased skin penetration of ketotifen was observed as the amount of liquid paraffin in the patch was increased. In addition, we found that lauric acid was a suitable enhancer for percutaneous absorption of ketotifen. Challenge tests were performed in guinea pigs to determine the therapeutic effect of the delivery systems for the inhibition of anaphylactic shock using varied concentrations of chicken ovum albumin as sensitizer. Our results showed that compared with the treatment of intramuscular administration, the skin patch was more effective and produced higher survival rates. The pharmacokinetics of the ketotifen patch were determined by applying the skin patch to the dorsal skin of rabbits. The plasma levels were maintained constant (42.5-36.4 ng/ml) from 9 to 30 hr. From our study, the prepared ketotifen patch may further be developed for the treatment or prevention of allergic asthma.

Acetogenins from seeds of Annona reticulata

Chromatography of an ethyl acetate extract of seeds of Annona reticulata led to the isolation of a new cytotoxic gamma-lactone acetogenin, cis-/trans-isomurisolenin, along with six known cytotoxic acetogenins, annoreticuin, annoreticuin-9-one, bullatacin, squamocin, cis-/trans-bullatacinone and cis-/trans-murisolinone. Structures of these compounds were established by means of mass and related spectral experiments. Some of the compounds isolated, showed potent cytotoxicities against Hep. 2,2,15, Hep. G2, KB and CCM2, four cancer cell-lines.

Determination of blood sugars by high pressure liquid chromatography with fluorescent detection

In this study, a high pressure liquid chromatography method with fluorescent detector was developed to analyze blood galactose, lactose and glucose simultaneously. Plasma sugars were prepared as fluorescent derivatives to react with FMOC-hydrazine (9-fluorenyl methyl chloroformate). A C18 reversed phase column and a fluorescent detector were used and run in ambient. The resolution index of galactose and glucose derivatives in the analytical method was 1.15. The coefficients of variation of the analysis were less than 7.5%. The concentration of FMOC-hydrazine did not significantly influence the analytical results for determination of the concentration of galactose. However, the ratios of acetonitrile in the mobile phase significantly affected the analysis of the fluorescent derivatives of sugars. The sensitivity of this method for galactose detection was 5 micrograms ml-1, and the required plasma volume for testing was only 25 microliters each. This analytical method was successfully applied to study the pharmacokinetics of galactose in vivo in a rabbit model.

The rapid flow of cerebrospinal fluid from ventricles to cisterns via subarachnoid velae in the normal rat

14C-sucrose in 0.5 microliter of buffered saline was infused over 30 sec into one lateral ventricle, and its subsequent distribution was determined in brain, meninges, cerebral blood vessels, and cerebrospinal fluid (CSF) by quantitative autoradiography. Within 3.5 min, infused radiotracer had moved into the third ventricle, the velum interpositum (an extension of the subarchnoid system that contains many blood vessels), the aqueduct, the mesencephalic and fourth ventricles, and the superior medullary velum (a part of the subarachnoid system that touches the mesencephalic and fourth ventricles). The CSF within both of these velae appears to empty into the quadrigeminal and ambient cisterns. Within 5 min radioactive sucrose was also found in the interpeduncular cistern. About 15% of the injected sucrose quickly left the ventricles and entered these large cisterns. In contrast to most CSF-brain interfaces, little sucrose moved from CSF into the medulla next to the lateral recesses and tissues such as the superior colliculus that lie adjacent to the large CSF cisterns. A thick, multilayered glia limitans visible on electron micrographs seemed to form a CSF-brain barrier at these interfaces. Some of the infused 14C-sucrose persisted in the perivascular spaces and walls of arteries and arterioles for more than 3.5 hr. These findings suggest that CSF may function to deliver various agents and factors to pial and parenchymal arteries and arterioles.

DNA immunization with Japanese encephalitis virus nonstructural protein NS1 elicits protective immunity in mice

Japanese encephalitis virus (JEV), a mosquito-borne flavivirus, is a zoonotic pathogen that is prevalent in some Southeast Asian countries and causes acute encephalitis in humans. To evaluate the potential application of gene immunization to JEV infection, we characterized the immune responses from mice intramuscularly injected with plasmid DNA encoding JEV glycoproteins, including the precursor membrane (prM) plus envelope (E) proteins and the nonstructural protein NS1. When injected with the plasmid expressing prM plus E, 70% of the immunized mice survived after a lethal JEV challenge, whereas when immunized with the plasmid expressing NS1, 90% of the mice survived after a lethal challenge. As a control, the mice immunized with the DNA vector pcDNA3 showed a low level (40%) of protection, suggesting a nonspecific adjuvant effect of the plasmid DNA. Despite having no detectable neutralizing activity, the NS1 immunization elicited a strong antibody response exhibiting cytolytic activity against JEV-infected cells in a complement-dependent manner. By contrast, immunization with a construct expressing a longer NS1 protein (NS1'), containing an extra 60-amino-acid portion from the N terminus of NS2A, failed to protect mice against a lethal challenge. Biochemical analyses revealed that when individually expressed, NS1 but not NS1' could be readily secreted as a homodimer in large quantity and could also be efficiently expressed on the cell surface. Interestingly, when NS1 and NS1' coexisted in cells, the level of NS1 cell surface expression was much lower than that in cells expressing NS1 alone. These data imply that the presence of partial NS2A might have a negative influence on an NS1-based DNA vaccine. The results herein clearly illustrate that immunization with DNA expressing NS1 alone is sufficient to protect mice against a lethal JEV challenge.

Osteoblast precursor cells are found in CD34+ cells from human bone marrow

It is known that osteoblast precursor cells are found in the low-density mononuclear (LDMN) fraction of human bone marrow (BM) aspirates. The purpose of this study was to investigate whether CD34, a hematopoietic progenitor cell marker, is present on osteoblast progenitor cells. LDMN, CD34+, and CD34- cells were cultured under conditions that promote growth and differentiation of mineral-secreting osteoblasts in a limiting dilution manner. With LDMN cells, osteoblast progenitor cells were found at an average frequency of 1/36,000 cells. With CD34- cells, osteoblast progenitor frequency remained at an average of 1/33,000, similar to LDMN cells. With CD34+ selected cells, osteoblast progenitor frequency increased to an average of 1/5,000. This osteoblast progenitor frequency is maintained in sorted CD34+/CD38+ cells. The osteoblasts generated from CD34+ cells were morphologically normal, and expression of skeletal-specific alkaline phosphatase and osteonectin increased upon differentiation induced by dexamethasone (DEX) treatment. Ultrastructurally, these CD34+ cell-derived osteoblasts displayed osteoblast-specific features. Functionally, these CD34+ cell-derived osteoblasts differentiated with DEX treatment, increased the level of cyclic adenosine monophosphate in response to parathyroid hormone stimulation, increased the level of alkaline phosphatase activity, and increased mineral secretion. These results demonstrate that osteoblast progenitor cells are enriched in the CD34+ cell population from BM and that these progenitor cells can differentiate into functional osteoblasts in culture.

Inositol triphosphate receptors in sea urchin sperm

Inositol 1,4,5-triphosphate (Ins(1,4,5)P3) is a second messenger that regulates Ca2+ channels in many important cell signalling pathways. In sea urchin sperm the outer investment of the egg triggers the acrosome reaction (AR) that involves Ins(1,4,5)P3 production and the opening of two Ca2+ channels. Here we have sought to identify a high-affinity Ins(1,4,5)P3 receptor in Strongylocentrotus purpuratus sperm. An Ins(1,4,5)P3 binding component was affinity-purified 12-fold from sperm extracts. It displayed similar characteristics to the Ins(1,4,5)P3 receptor from other sources: pH-dependent high affinity for Ins(1,4,5)P3 (KD = 261 nM), a tau1/2 of association and dissociation of 50 and 40 s, respectively, specificity (IC50 > 5 microM for Ins(1)P1, Ins(1,4)P2 and Ins(1,3,4,5)P4), and pharmacological sensitivity (10 and 100 microg heparin/ml inhibited 75% and 100% binding respectively). An antibody against the carboxy-terminal of the type I Ins(1,4,5)P3 receptor of somatic cells recognised a plasma membrane component in the sperm head and less intensely in the flagella. This antibody also recognised a 240 kDa band from isolated head plasma membranes, and weakly in flagellar membrane. This IP3 receptor-like protein may mediate the sustained uptake of Ca2+ through the second Ca2+ channel opened during the AR.

Two new lignans with activity against influenza virus from the medicinal plant Rhinacanthus nasutus

Two new lignans, rhinacanthin E (1) and rhinacanthin F (2), were isolated from the aerial parts of the plant Rhinacanthus nasutus. Their structures were established by detailed spectroscopic analysis. These compounds show significant antiviral activity against influenza virus type A.

Recipient bed vascularity and the survival of ischaemic flaps

The purpose of this study was to identify the length of the ischaemic period required to induce the 'no-reflow' phenomenon in a rat epigastric flap on an avascular recipient site. The vascularity of the recipient bed may affect flap survival in the early postischaemic stage after flap transfer. Initially, we designed epigastric flaps in 300-350 g Sprague-Dawley rats and separated the rats into four groups of 5 rats each (total 20 rats). In groups 1, 2, 3, the flaps were made ischaemic for 1 hour, 6 hours and 10 hours, respectively, by temporarily clipping the epigastric artery and vein. In group 4, the epigastric artery and vein were divided to create permanent ischaemia. In groups 1, 2 and 3, ischaemia was ended by removing the clips. After the ischaemic flaps were reperfused, their viability was studied by measuring the flap survival rate at postoperative day 7. Flap survival was studied by direct observations, laser Doppler flowmeter measurement of flap blood flow, histopathology, and carbon particle perfusion of the flap vasculature. Ischaemic flaps of groups 1 and 2 recovered almost completely after reperfusion due to the short period of ischaema. In a second series of experiments, in order to evaluate the contribution to flap survival of the recipient vascularised bed, another four groups of epigastric flaps (of 5 animals each, using the same time periods as above) were raised and a piece of Biobrane was interposed between the flap and the recipient bed before the flap wound was closed, to eliminate all nutrient supply from the recipient bed. THe results showed that the combined effect of the reperfused flap vasculature plus the metabolic contribution of the recipient bed significantly (P < 0.01) increased the extent of flap survival of the 6- and 10-hour ischaemic flaps as well as the divided pedicle flaps, which were never reperfused. An absolute 'no-reflow' rat model flap for further flap salvage studies was also developed.

Analysis of the tertiary structure of the ribonuclease P ribozyme-substrate complex by site-specific photoaffinity crosslinking

Bacterial ribonuclease P (RNase P), an endonuclease involved in tRNA maturation, is a ribonucleoprotein containing a catalytic RNA. The secondary structure of this ribozyme is well-established, and a low-resolution model of the three-dimensional structure of the ribozyme-substrate complex has been proposed based on site-specific crosslinking and phylogenetic comparative data [Harris ME et al., 1994 EMBO J 13:3953-3963]. However, several substructures of that model were poorly constrained by the available data. In the present analysis, additional constraints between elements within the Escherichia coli RNase P RNA-pre-tRNA complex were determined by intra- and intermolecular crosslinking experiments. Circularly permuted RNase P RNAs were used to position an azidophenacyl photoactive crosslinking agent specifically at strategic sites within the ribozyme-substrate complex. Crosslink sites were mapped by primer extension and confirmed by analysis of the mobility of the crosslinked RNA lariats on denaturing acrylamide gels relative to circular and linear RNA standards. Crosslinked species generally retained significant catalytic activity, indicating that the results reflect the native ribozyme structure. The crosslinking results support the general configuration of the structure model and predicate new positions and orientations for helices that were previously poorly constrained by the data set. The expanded library of crosslinking constraints was used, together with secondary and tertiary structure identified by phylogenetic sequence comparisons, to refine significantly the model of RNase P RNA with bound substrate pre-tRNA. The crosslinking results and data from chemical-modification and mutational studies are discussed in the context of the current structural perspective on this ribozyme.

International differences in approaches to 131I therapy for Graves' disease: case selection and restrictions recommended to patients in Japan, Korea, and China

Members of the American Thyroid Association (ATA), European Thyroid Association (ETA), Japan Thyroid Association (JTA), Korean Thyroid Association (KTA), and Chinese Thyroid Association (CTA) were surveyed independently through an identical questionnaire on their management of Graves' disease. One of the major purposes of the survey was to determine how expert thyroidologists in different regions of the world use three different therapies available for a typical Graves' patient as well as for clinical variations provided. In this report, we summarized, contrasted, and interpreted the results of the surveys in three Asian countries by focusing on therapeutic preference of radioiodine. For the index patient with hyperthyroidism due to Graves' disease, radioiodine was the therapy of choice for 69% of ATA respondents but only 22%, 22%, 11%, and 11% of ETA, CTA, JTA, and KTA respondents, respectively. The goal of radioiodine therapy in Asian countries was to restore the euthyroid state. For the case of recurrence after surgery, there was consensus on choosing radioiodine among all countries surveyed. To interpret the reluctance to advocate radioiodine therapy for a typical Graves' patient in Japan, a new survey concerning the current trends in radioiodine therapy in Japan was conducted among clinical members of the JTA. The phobia of radiation and stringent safety rules for radioactive pharmaceuticals were the two major reasons found. Nevertheless, the percentage of JTA respondents who aim for the euthyroid of hypothyroid state by radioiodine therapy for typical Graves' significantly increased compared with respondents to the former survey in 1988. Moreover, a considerable number of JTA members believe that more radioiodine therapy should be applied for achievement of the rapid improvement of hyperthyroidism, for convenience, and for medical cost benefits.

Phosphorylated states of vesicular stomatitis virus P protein in vitro and in vivo

We have previously shown that the phosphoprotein (P) of vesicular stomatitis virus (VSV), New Jersey serotype (PNJ) is phosphorylated by casein kinase II, within the N-terminal domain I (P1 form), whereas the C-terminal domain II is phosphorylated by a protein kinase activity associated with the L protein (P2 form) (D. J. Chattopadhyay and A.K. Banerjee, Cell 49, 407, 1987; A.M. Takacs et al., J. Virol. 66, 5842, 1992). In the present studies, we have mapped the corresponding P1 and P2 phosphorylation sites in the P protein of the well-studied Indiana serotype (PIND) and compared that with the two previously designated NS1 and NS2 forms present in vivo. The PIND expressed in Escherichia coli in an unphosphorylated form (P0) was used as substrate for recombinant casein kinase II (CKII). By site-directed mutagenesis, the CKII-mediated phosphorylation sites in the P protein were mapped at S60, T62, and S64 within the acidic domain I in vitro. In contrast, using BHK cell extract as the source of CKII or expressing P protein in COS cells labeled with 32PI, the phosphorylation sites were mapped at S60 and S64 with no phosphorylation at T62 residue. We used a peptide mapping technique by which the phosphorylation sites within domain I and domain II were determined. Using this method we demonstrated that the P1 and P2 forms are similar, if not identical, to the previously designated NS1 and NS2 forms, respectively. The domain II phosphorylating kinase activity, associated with the L protein, is shown to be present also in the N-RNA complex, indicating that this activity is of cellular origin. By site-directed mutagenesis, we have shown that S226 and S227 are involved in phosphorylation within domain II. We also demonstrate that the P1 and P2 forms are interconvertible and arise by phosphorylation/dephosphorylation of the phosphate groups in domain II, confirming the precursor-product relationship between the two phosphorylated forms of P protein.

Rapid distribution of intraventricularly administered sucrose into cerebrospinal fluid cisterns via subarachnoid velae in rat

The intracranial distribution of [14C]sucrose, an extracellular marker infused for 30 s into one lateral ventricle, was determined by autoradiography of frozen-dried brain sections. Within 3.5 min [14C]sucrose appeared in: (i) the third ventricle, including optic, infundibular and mammillary recesses; (ii) the aqueduct of Sylvius; (iii) the velum interpositum, a part of the subarachnoid space that runs along the roof of the third ventricle and contains many blood vessels; (iv) the mesencephalic and fourth ventricles; and (v) the superior medullary velum, a highly vascular extension of the subarachnoid space that terminates at the walls of the mesencephalic and fourth ventricles. Within 5 min, radioactivity was present in the interpeduncular, ambient and quadrigeminal cisterns, which encircle the midbrain. By 10 min, approximately 11% of the radioactivity had passed into the subarachnoid space via a previously undescribed flow pathway that included the velum interpositum and superior medullary velum. At many places along the ventricular system, [14C]sucrose appeared to move from cerebrospinal fluid into the adjacent tissue by simple diffusion, as reported previously (Blasberg R. G. et al. (1974) J. Pharmac. exp. Ther. 195, 73-83; Levin V. A. et al. (1970) Am. J. Physiol. 219, 1528-1533; Patlak C. and Fenstermacher J.D. (1975) Am. J. Physiol. 229, 877-884; Rosenberg G. A. and Kyner W.T. (1980) Brain Res. 193, 56-66; Rosenberg G. A. et al. (1986) Am. J. Physiol 251, F485-F489). Little sucrose was, however, taken up by: (i) circumventricular organs such as the subfornical organ; (ii) medullary and cerebellar tissue next to the lateral recesses; and (iii) the superior and inferior colliculi and cerebral peduncles. For the latter two groups of structures, entry from cerebrospinal fluid was apparently blocked by a thick, multilayered glia limitans. Although [14C]sucrose was virtually absent from the rest of the subarachnoid system after 1 h, it remained in the perivascular spaces and/or walls of pial arteries and arterioles for more than 3 h. Certain transport proteins, protease inhibitors, growth factors and other neurobiologically active materials are present in cerebrospinal fluid, and their distribution to the brain and its blood vessels may be important. The present work shows, in the rat, that the flow of cerebrospinal fluid and the disposition of its constituents is fairly complex and differs among regions. Flow was rapid throughout the ventricular system and into various subarachnoid velae and cisterns, but was surprisingly slow and slight over the cerebral and cerebellar cortices. The cerebrospinal fluid-to-tissue flux of material was relatively free at many interfaces, but was greatly restricted at others, the latter indicating that the old concept of a "cerebrospinal fluid-brain barrier" may hold at such places. Finally, radiolabeled sucrose was retained longer within the walls and perivascular spaces of pial arteries and arterioles than in other subarachnoid tissues; one function of the cerebrospinal fluid system or "third circulation" may thus be delivering factors and agents to these pial blood vessels.

Molecular cloning and analysis of two subunits of the human TFIID complex: hTAFII130 and hTAFII100

Transcription factor TFIID is a multiprotein complex composed of the TATA box-binding protein (TBP) and multiple TBP-associated factors (TAFs). TFIID plays an essential role in mediating transcriptional activation by gene-specific activators. Numerous transcriptional activators have been characterized from mammalian cells; however, molecular analysis of the components of mammalian TFIID has been incomplete. Here we describe isolation of cDNAs encoding two TAF subunits of the human transcription factor TFIID. The first cDNA is predicted to encode the C-terminal 947 residues of the 130-kDa human TAF subunit, hTAFII130. The second cDNA encodes the C-terminal 801 residues of the 100-kDa subunit, hTAFII100. Recombinant TAFs expressed in human cells by transient transfections are capable of associating with the endogenous TAFs and TBP to form a TFIID complex in vivo. Protein binding experiments demonstrate that hTAFII130, like its Drosophila homolog dTAFII110, interacts with the glutamine-rich activation domains of the human transcription factor Sp1. Furthermore, hTAFII130 shows reduced binding to the Sp1 mutants with impaired ability to activate transcription, suggesting a role for hTAFII130 as a direct coactivator target for Sp1.