bluuebunny/crossref_metadata_2025 huggingface dataset:
The pattern of CD38 expression defines a distinct subset of chronic lymphocytic leukemia (CLL) patients at risk of disease progression
Authors: Ghia Paolo , Guida Giuseppe , Stella Stefania , Gottardi Daniela , Geuna Massimo , Strola Giuliana , Scielzo Cristina , Caligaris-Cappio Federico
Published: January 2003

Chronic lymphocytic leukemia (CLL) has a variable clinical course. CD38 expression and IgVH gene mutational status are independent predictors of prognosis, but their relationships and the CD38 cutoff level are unknown. Using cytofluorography, we analyzed CD38 in 148 patients, in 108 of whom we were able to evaluate IgVH mutations, make correlations with disease history, and assess cumulative survival. Three different patient groups were identified by the CD38 expression pattern: a group homogeneously CD38−, a group homogeneously CD38+, and a group characterized by a bimodal profile, because of the concomitant presence of variable proportions of 2 distinct populations, one CD38+ and one CD38−. In CD38 bimodal expression patients the CD38+ subset was significantly more represented in the bone marrow than in the peripheral blood. For IgVH mutations, 11.4% of CD38−, 84.6% of CD38+, and 68.0% of CD38 bimodal expression patients had no mutation. CD38 expression, IgVH mutational status, and traditional prognostic factors were concordant. The progression rate was 12.9% for CD38−, 75.0% for CD38+, and 63.3% for CD38 bimodal expression patients. Only 25.8% of the CD38−patients but 63.3% of the bimodal and 75.0% of CD38+patients were treated. The presence of a CD38+ population, albeit small, correlated with the development of autoimmune manifestations. The CD38− group has not yet reached the median survival, which is 183 months in the CD38+ group and 156 months in the CD38 bimodal expression group, regardless of the size of the CD38+ population. The presence of a distinct CD38+ population within the leukemic clone, rather than a numerical cutoff definition, correlates with IgVH gene mutational status and, irrespective of its size, identifies CLL patients who will have progressive disease.
Histone deacetylase inhibitors: a new class of immunosuppressors targeting a novel signal pathway essential for CD154 expression
Authors: Skov Søren , Rieneck Klaus , Bovin Lone Frier , Skak Kresten , Tomra Søren , Michelsen Birgitte K. , Ødum Niels
Published: January 2003

Here we report that histone deacetylase inhibitors (HDAC-i) comprise a new class of immunosuppressive agents. HDAC-i inhibited CD4 T-cell proliferation in a dose-dependent manner, which was not caused by apoptosis or decreased viability. Although early intracellular signals such as tyrosine kinase activity and elevation of intracellular calcium concentration were not affected, the characteristic aggregation of T cells following activation was completely abrogated. This correlated with diminished activation-induced expression of the adhesion molecules. HDAC-i furthermore inhibited activation-induced CD25 and CD154 expression on CD4 cells, without affecting induction of CD69. HDAC-i inhibited CD154 expression by a mechanism distinctly different from cyclosporine-mediated inhibition. HDAC-i thus inhibited interleukin 2 (IL-2)–induced CD154 expression on effector T cells and constitutively expressed CD154 on various tumor cells, events that were not affected by cyclosporine. Additional studies showed that HDAC-i treatment inhibited c-Myc expression, which was further shown to be important for CD154 gene activation. These results demonstrate pronounced T-cell inhibitory activity of HDAC-i, which may form the basis of novel therapeutic interventions against autoimmune diseases and allograft rejection.
Autocrine-paracrine VEGF loops potentiate the maturation of megakaryocytic precursors through Flt1 receptor
Authors: Casella Ida , Feccia Tiziana , Chelucci Cristiana , Samoggia Paola , Castelli Germana , Guerriero Raffaella , Parolini Isabella , Petrucci Eleonora , Pelosi Elvira , Morsilli Ornella , Gabbianelli Marco , Testa Ugo , Peschle Cesare
Published: January 2003

The expression/function of vascular endothelial growth factor (VEGF) receptors (VEGFR1/Flt1 and VEGFR2/KDR/Flk1) in hematopoiesis is under scrutiny. We have investigated the expression of Flt1 and kinase domain receptor (KDR) on hematopoietic precursors, as evaluated in liquid culture of CD34+ hematopoietic progenitor cells (HPCs) induced to unilineage differentiation/maturation through the erythroid (E), megakaryocytic (Mk), granulocytic (G), or monocytic (Mo) lineage. KDR, expressed on 0.5% to 1.5% CD34+ cells, is rapidly downmodulated on induction of differentiation. Similarly, Flt1 is present at very low levels in HPCs and is downmodulated in E and G lineages; however, Flt1 is induced in the precursors of both Mo and Mk series; ie, its level progressively increases during Mo maturation, and it peaks at the initial-intermediate culture stages in the Mk lineage. Functional experiments indicate that Mk and E, but not G and Mo, precursors release significant amounts of VEGF in the culture medium, particularly at low O2 levels. The functional role of VEGF release on Mk maturation is indicated by 2 series of observations. (1) Molecules preventing the VEGF-Flt1 interaction on the precursor membrane (eg, soluble Flt1 receptors) significantly inhibit Mk polyploidization. (2) Addition of exogenous VEGF or placenta growth factor (PlGF) markedly potentiates Mk maturation. Conversely, VEGF does not modify Mo differentiation/maturation. Altogether, our results suggest that in the hematopoietic microenvironment an autocrine VEGF loop contributes to optimal Mk maturation through Flt1. A paracrine loop involving VEGF release by E precursors may also operate. Similarly, recent studies indicate that an autocrine loop involving VEGF and Flt1/Flk1 receptors mediates hematopoietic stem cell survival and differentiation.
Critical independent regions in the VWF propeptide and mature VWF that enable normal VWF storage
Authors: Haberichter Sandra L. , Jacobi Paula , Montgomery Robert R.
Published: January 2003

Von Willebrand factor (VWF) is synthesized in endothelial cells, where it is stored in Weibel-Palade bodies. Administration of 1-desamino-8-D-arginine-vasopressin (DDAVP) to patients with type 1 von Willebrand disease and to healthy individuals causes a rapid increase in plasma VWF levels. This increase is the result of stimulated release of VWF from Weibel-Palade bodies in certain beds of endothelial cells. The VWF propeptide (VWFpp) targets VWF to storage granules through a noncovalent association. The nature of the VWFpp/VWF interaction was investigated by using cross-species differences in VWF storage. While canine VWFpp traffics to storage granules and facilitates the multimerization of human VWF, it does not direct human VWF to storage granules. Since storage takes place after furin cleavage, this defect appears to be due to the defective interaction of canine VWFpp and human VWF. To determine the regions within VWFpp and VWF important for this VWFpp/VWF association and costorage, a series of human-canine chimeric VWFpp and propeptide-deleted VWF (Δpro) constructs were produced and expressed in AtT-20 cells. The intracellular localization of coexpressed proteins was examined by confocal microscopy. Two amino acids, 416 in VWFpp and 869 in the mature VWF molecule, were identified as being critical for the association and granular storage of VWF.
Induction of CD4+/CD25+ regulatory T cells by targeting of antigens to immature dendritic cells
Authors: Mahnke Karsten , Qian Yingjie , Knop Jürgen , Enk Alexander H.
Published: January 2003

Coupling of ovalbumin (OVA) to anti–DEC-205 monoclonal antibody (mAb) (αDEC) induced the proliferation of OVA-specific T cells in vivo. Expansion was short-lived, caused by dendritic cells (DCs), and rendered T cells anergic thereafter. Phenotypic analysis revealed the induction of CD25+/CTLA-4+ T cells suppressing proliferation and interleukin-2 (IL-2) production of effector CD4+ T cells. The findings were supported by 2 disease models: (1) CD4+ T-cell–mediated hypersensitivity reactions were suppressed by the injection of αDEC-OVA and (2) the application of hapten-coupled αDEC-205 reduced CD8+ T-cell–mediated allergic reactions. Thus, targeting of antigens to immature DCs through αDEC antibodies led to the induction of regulatory T cells, providing the basis for novel strategies to induce regulatory T cells in vivo.
Predictors of Biochemical Outcome With Salvage Conformal Radiotherapy After Radical Prostatectomy for Prostate Cancer
Authors: Katz Matthew S. , Zelefsky Michael J. , Venkatraman Ennapadam S. , Fuks Zvi , Hummer Amanda , Leibel Steven A.
Published: January 2003

Purpose: To identify predictors of biochemical outcome following radiotherapy in patients with a rising prostate-specific antigen (PSA) after radical prostatectomy for prostate cancer.

Patients and Methods: One hundred fifteen patients with a rising PSA after radical prostatectomy received salvage three-dimensional conformal radiotherapy (3D-CRT) alone or with neoadjuvant androgen deprivation. Tumor-related and treatment-related factors were evaluated to identify predictors of subsequent PSA failure.

Results: The median follow-up time after 3D-CRT was 42 months. The 4-year actuarial PSA relapse-free survival, distant metastasis-free survival, and overall survival rates were 46%, 83%, and 95%, respectively. Multivariate analysis, which was limited to 70 patients receiving radiation without androgen deprivation therapy, showed that negative/close margins (P = .03), absence of extracapsular extension (P < .01), and presence of seminal vesicle invasion (P < .01) were independent predictors of PSA relapse after radiotherapy. Neoadjuvant androgen deprivation did not improve the 4-year PSA relapse-free survival in patients with positive margins, extracapsular extension, and no seminal vesicle invasion (P = .24). However, neoadjuvant androgen deprivation did improve PSA relapse-free survival when one or more of these variables were absent (P = .03).

Conclusions: Salvage 3D-CRT can provide biochemical control in selected patients with a rising PSA after radical prostatectomy. Among patients with positive margins and no poor prognostic features, 77% achieved PSA control after salvage 3D-CRT. Salvage neoadjuvant androgen deprivation therapy may improve short-term biochemical control, but it requires further study.
Continuous infusion versus intermittent administration of cefepime in patients with Gram-negative bacilli bacteraemia
Authors: Jaruratanasirikul Sutep , Sriwiriyajan Somchai , Ingviya Natnicha
Published: January 2003

The objective of this study was to compare the pharmacokinetics of cefepime administered by continuous infusion and intermittent injection regimens. A prospective, randomized, cross-over study of ten patients with Gram-negative bacilli bacteraemia was conducted. All patients were randomized to receive cefepime either as a 4-g continuous infusion over 24 h for 48 h or a 2-g bolus administered intermittently intravenously every 12 h for 48 h. After 48 h the patients received the alternative dose regimen. Cefepime pharmacokinetic studies were carried out during hours 36–48 after the start of both regimens. All of the pathogens isolated from the blood in 7 patients had a minimum inhibitory concentration (MIC) < 1 μg mL−1. In both regimens, the serum cefepime concentrations at all time points were higher than the MIC for the pathogens isolated from this study. For the continuous infusion arm, the highest steady-state concentration was 49.80±18.40 μg mL−1 and the lowest steady-state concentration was 41.42±16.48 μg mL−1. The steady-state concentrations were greater than 4 times the MIC of 8 μg mL−1. For the intermittent injection regimen, the mean trough concentration was 4.74±3.99 μg mL−1. The mean serum cefepime concentration was above 8 μg mL−1 for 81.66% of the dosing interval. Therefore, we conclude that either continuous infusion or intermittent injection can be used as an effective mode of cefepime administration to achieve bactericidal activity.
The effect of the isomers of cyclo(Trp-Pro) on heart and ion-channel activity
Authors: Jamie Hajierah , Kilian Gareth , Dyason Karin , Milne Pieter J
Published: January 2003

Cyclo(l-Trp-l-Pro) has shown potential for use in the treatment of cardiovascular dysfunction. The aim of the study was to determine the effects of the isomers of cyclo(Trp-Pro) - cyclo(l-Trp-l-Pro), cyclo(l-Trp-d-Pro), cyclo(d-Trp-l-Pro) and cyclo(d-Trp-d-Pro) - on heart and ion-channel activity. The effects on L-type Ca2+-channel, Na+-channel and inward rectifier K+-channel activity were determined by using the whole-cell patch-clamp technique on myocytes of guinea-pig origin. Dependence on the membrane potential in terms of Ca2+-channel activity was also investigated. A modified Langendorff method was used to determine the effects of the isomers on heart rate, coronary flow, duration of ventricular tachycardia and arrhythmia, time to sinus rhythm and QRS interval on the rat isolated heart. Cyclo(l-Trp-l-Pro), cyclo(l-Trp-d-Pro) and cyclo(d-Trp-d-Pro), 100 μm, showed agonism towards Ca2+-channel activity, while cyclo(d-Trp-l-Pro) caused a blockage of the current. The action of cyclo(d-Trp-l-Pro) was shown to be independent of membrane potential. No significant effect (P > 0.05) on the inward rectifier K+ current was observed in the presence of cyclo(l-Trp-d-Pro) and cyclo(d-Trp-d-Pro), while antagonism was noted in the presence of cyclo(l-Trp-l-Pro) and cyclo(d-Trp-l-Pro). All isomers showed antagonist effects on the Na+ channel. No adverse effects were noted on chronotropic effects in the presence of 200 μm cyclo(l-Trp-l-Pro) and cyclo(d-Trp-d-Pro) (P > 0.05), while cyclo(l-Trp-d-Pro) significantly increased the heart rate. Cyclo(d-Trp-l-Pro) significantly reduced the heart rate (P < 0.05). In addition, no significant effects were observed on the coronary flow rate in the presence of the isomers. All isomers significantly reduced the duration of ventricular tachycardia and arrhythmia, as well as the time to sinus rhythm. Furthermore, no change in the QRS intervals was noted in the presence of the isomers in comparison with the control, with a significant increase being noted for cyclo(d-Trp-d-Pro) (P < 0.05) in reference to the other isomers. The isomers thus show antiarrhythmic potential and may manifest as novel agents in the treatment of cardiovascular dysfunction, since a decrease in ventricular fibrillation may reduce the mortality rates in acute myocardial infarction.
Aspirin and sodium salicylate inhibit proliferation and induce apoptosis in rheumatoid synovial cells
Authors: Yamazaki Ryuta , Kusunoki Natsuko , Matsuzaki Takeshi , Hashimoto Shusuke , Kawai Shinichi
Published: January 2003

Aspirin has been reported to induce apoptosis in a variety of cell lines. In this study, we examined whether aspirin and sodium salicylate inhibit cell growth and induce apoptosis in rheumatoid synovial cells. Synovial cells were obtained from patients with rheumatoid arthritis, and the cells were treated with aspirin or sodium salicylate (0.1–10 mm) for 24 h. Cell proliferation and viability were assessed by 5-bromo-2′-deoxyuridine incorporation and by 4-[3-(4-iodophenyl)-2-(4-nitrophenyl)-2H-5-tetrazolio]-1,3-benzene disulfonate (WST-1) assay, respectively. The apoptosis of synovial cells was identified by DNA fragmentation assay and terminal deoxynucleotidyl transferase-mediated dUTP nick end labelling (TUNEL) assay. Aspirin and sodium salicylate suppressed the proliferation (IC50 (concentration causing 50% inhibition of cell proliferation): 2.1 and 1.2 mm, respectively) and reduced the viability (IC50: 2.0 and 1.4 mm respectively) of synovial cells in a concentration-dependent manner at 0.3–10 mm. Furthermore, they induced DNA fragmentation and increased the number of TUNEL- positive synovial cells. These results suggest that aspirin and sodium salicylate can inhibit the proliferation of rheumatoid synovial cells through induction of apoptosis.
Topical delivery of plasmid DNA using biphasic lipid vesicles (Biphasix)
Authors: Babiuk Shawn , Baca-Estrada Maria E , Pontarollo Reno , Foldvari Marianna
Published: January 2003

The development of non-invasive methods for the delivery of vaccines through the skin will greatly improve the safety and the administration of human and veterinary vaccines. In this study we examined the efficiency of topical delivery of plasmids by assessing the localization of gene expression using luciferase as a reporter gene and induction of immune responses using a plasmid encoding for the bovine herpesvirus type-1 glycoprotein D (pgD). Topical administration of plasmids in a lipid-based delivery system (biphasic lipid vesicles – Biphasix) resulted in gene expression in the lymph node, whereas with intradermal injection, antigen expression was found in the skin. Following administration of plasmid with the gene gun, antigen expression was observed in both the skin as well as in the draining lymph nodes. Transcutaneous immunization with pgD formulated in biphasic lipid vesicles elicited gD-specific antibody responses and a Th2-type cellular response. In contrast, immunization by the intradermal route resulted in the stimulation of a Th1-type response. These findings have implications for both vaccine design and tailoring of specific immune responses.
Autoantibodies to malondialdehyde-modified low-density lipoprotein in patients with angiographically confirmed coronary artery disease
Authors: McDowell A , Young I S , Wisdom G B
Published: January 2003

Oxidised low-density lipoprotein (LDL) has physicochemical properties that are pivotal in atherosclerotic plaque formation. As a consequence, antioxidant regimens may prove an important therapy in the prevention and treatment of cardiovascular disease. Since oxidised LDL is immunogenic, the aims of our study were to measure serum IgG titres to malondialdehyde-modified LDL (MDA-LDL) in patients with coronary artery disease (CAD) and control subjects and assess their potential as a clinical marker for coronary atherosclerosis and, consequently, antioxidant intervention. Serum IgG titres to MDA-LDL were measured in patients with angiographically confirmed CAD (n = 40) and aged-matched controls (n = 40) by enzyme-linked immunosorbant assay (ELISA). Titres were calculated and expressed as both the difference and the ratio of blanked absorbance units (AU) for IgG binding to MDA-LDL and native LDL. For the control population, median IgG titres were 0.26 AU (interquartile range (IQR) 0.20–0.46 AU) and 5.34 (IQR 3.40–8.58), respectively, while the patient population had median IgG titres of 0.30 AU (IQR 0.20–0.47 AU) and 5.08 (IQR 3.30–9.66), respectively. Both sets of calculated titre values were not significantly different between the two groups (P = 0.60 and 0.82, respectively). In conclusion, this study could not establish any significant association between circulating autoantibody titres to MDA-LDL and coronary atherosclerosis. Therefore, the diagnostic value of autoantibodies to oxidised LDL remains unclear.
Biorelevant dissolution testing of St John's wort products
Authors: Westerhoff Kerstin , Kaunzinger Astrid , Wurglics Mario , Dressman Jennifer , Schubert-Zsilavecz Manfred
Published: January 2003

In contrast to chemically defined drugs, most herbal medicinal products (HMPs) are poorly characterized in terms of their pharmaceutical properties. In many cases it is assumed that the plant extract as a whole is the active moiety, since it is often difficult to identify the individual components responsible for the pharmacological activity and even more difficult to assess synergies among the various components. However, where the active components have been identified, it should be possible to compare products with respect not only to content uniformity but also to their biopharmaceutical properties. The aim of this study was to investigate and compare the dissolution characteristics of several St John's wort products under biorelevant conditions. Components of St John's wort known, or suspected, to play a role in its antidepressant activity include phloroglucines, naphthodianthrones and the flavonoids. Since these groups have a broad spectrum of polarity and solubility, dissolution was studied for representative compounds from each group. Although the labelling indicates that several of the products studied should be pharmaceutically equivalent, dissolution under biorelevant conditions revealed that they have quite different release profiles and cannot be considered switchable. It was concluded that biorelevant dissolution testing can be a powerful tool for comparing HMPs as well as synthetically produced drug products.
Metabolism and excretion of centbutindole (neuroleptic) in rats after oral administration
Authors: Issar M , Singh S K , Madhusudanan K P , Mishra B , Gupta R C
Published: January 2003

The metabolism and excretion of centbutindole was studied in Sprague-Dawley rats after oral administration. The percentage of dose excreted was monitored over 4 days. Efforts were also directed towards evaluating the stability of centbutindole in various in-vitro biomatrices. Centbutindole was found to be metabolised in rats and only a negligible amount of parent drug was excreted. The percentage of the dose excreted in bile and faeces was 0.2% and 0.6%, respectively. No drug was found in urine after oral administration, but after an intravenous dose only 0.0012% of the dose was eliminated through urine. Two metabolites, dealkylated metabolite and hydroxy metabolite, were identified by ion spray LC/MS/MS, using a combination of parent ion and product ion scanning techniques. The major routes of metabolism of centbutindole include reduction of the carbonyl functional group in the butyrophenone side chain and N-dealkylation of the butyrophenone side chain attached to the pyrazinopyridoindole ring nitrogen at position 2. The hydroxy metabolite was excreted negligibly in bile, although it was present in the form of glucuronide conjugates more in comparison to its free form.
Effects of acute renal failure induced by uranyl nitrate on the pharmacokinetics of intravenous theophylline in rats: the role of CYP2E1 induction in 1,3-dimethyluric acid formation
Authors: Yu Su Yeon , Chung Hye Chin , Kim Eun Jung , Kim So Hee , Lee Inchull , Kim Sang Geon , Lee Myung Gull
Published: January 2003

In rats with acute renal failure induced by uranyl nitrate, the hepatic microsomal cytochrome P450 (CYP) 2E1 and CYP3A23 increased 2–4- and 4-times, respectively, CYP2C11 decreased to 80% of control, but the levels of CYP1A2 and CYP2B1/2 were not changed. It has been reported that theophylline was metabolized to 1,3-dimethyluric acid by CYP1A2 and CYP2E1 and 1-methylxanthine via CYP1A2, which was metabolized further to 1-methyluric acid via xanthine oxidase in rats. Hence, it was expected that the formation of 1,3-dimethyluric acid would show an increase in rats with renal failure as a result of induction of CYP2E1. The pharmacokinetics of theophylline were compared in control rats and rats with renal failure after intravenous administration of aminophylline, 5 mg kg−1 as theophylline. In rats with renal failure, the plasma concentrations of theophylline were considerably lower and the resultant total area under the plasma concentration-time curve from time zero to time infinity (AUC0-∞) of theophylline was significantly smaller (2200 vs 1550 μg min mL−1) compared with control rats. In rats with renal failure, the plasma concentrations of 1,3-dimethyluric acid were considerably higher and the resultant AUC0–6 h of 1,3-dimethyluric acid was significantly greater (44.4 vs 456 μg min mL−1) compared with control rats. Moreover, the AUC0–6 h, 1,3-dimethyluric acid/ AUC0–∞, theophylline ratio increased from 2.02% in control rats to 29.4% in rats with renal failure. The in-vitro intrinsic 1,3-dimethyluric acid formation clearance was significantly faster in rats with renal failure (734 vs 529 10−6 mL min−1) compared with control rats using hepatic microsomal fraction. The results led us to conclude that in rats with uranyl nitrate-induced renal failure after the administration of aminophylline, 5 mg kg−1 as theophylline, there was an increase in the formation of 1,3-dimethyluric acid as a result of an increase in CYP2E1 expression.
α-Monoisostearyl glyceryl ether enhances percutaneous penetration of indometacin in-vivo
Authors: Suzuki Atsushi , Yamaguchi Tatsuyuki , Kawasaki Keiko , Hase Tadashi , Tokimitsu Ichiro
Published: January 2003

Molecules that reversibly remove the barrier resistance of skin enhance penetration. α-Monoisostearyl glyceryl ether (GE-IS) is a novel compound that can be used as a non-ionic surfactant and increases percutaneous penetration of indometacin in rat abdominal skin in-vitro. The present study investigated GE-IS-induced enhancement of indometacin penetration in-vivo. When 1% GE-IS in propylene glycol was applied to rat abdominal skin, serum and muscle concentrations of indometacin increased markedly. Anti-inflammatory activities of test solutions containing both indometacin and GE-IS were investigated in experimental models of acute and chronic inflammation. Application of indometacin with GE-IS to the skin produced greater inhibitory effects on carrageenan-induced rat paw oedema, UV-induced erythema in guinea-pigs, and adjuvant arthritis in rats, compared with application of indometacin alone. The results suggest that GE-IS enhances penetration in-vivo and improves the anti-inflammatory effects of indometacin in animal models. Thus, GE-IS might contribute to the development of cosmetic or medical formulations to improve transfer of bioactive substances to hypodermal sites.
Transbilayer transport of a propyltrimethylammonium derivative of diphenylhexatriene (TMAP-DPH) in bovine blood platelets and adrenal chromaffin cells
Authors: Kitagawa Shuji , Tachikawa Eiichi , Kashimoto Takashi
Published: January 2003

The membrane fluorescent probe N-((4-(6-phenyl-1,3,5-hexatrienyl)phenyl)propyl)trimethyl-ammonium (TMAP-DPH) has an additional three-carbon spacer between the fluorophore and the trimethylammonium substituent of 1-(4-trimethylammoniumphenyl)-6-phenyl-1,3,5-hexatriene (TMA-DPH). As a basic study to clarify the transport mechanism of amphiphilic quaternary ammoniums, we observed the characteristics of the transbilayer transport of TMAP-DPH in bovine blood platelets and bovine adrenal chromaffin cells using the albumin extraction method. We compared these inward transport rates with those of TMA-DPH. TMAP-DPH crossed into the cytoplasmic layers of the membranes more slowly than TMA-DPH after rapid binding to the outer halves of the plasma membranes. The transport rate markedly depended on temperature. Time to reach the half-maximal incorporated amount of TMAP-DPH increased threefold accompanied by an increase in the concentration from 0.2 to 1.5 μm. The transport was stimulated significantly by various types of membrane perturbations such as modification of sulfhydryl-groups by N-ethylmaleimide and benzyl alcohol-induced increase in the fluidity of the lipid bilayer. The saturation phenomenon suggested the presence of the regulatory process in the transbilayer transport of TMAP-DPH.
Synthesis and radical scavenging of novel magnolol derivatives
Authors: Wang Yvonne , Li Chi-Yuan , Lin I-Hshin , Lee An-Rong , Hu Ming-Kuan
Published: January 2003

We have investigated the developdment of potential antioxidants based on magnolol, a naturally occurring biphenolic obtained from the bark of Magnolia officinalis. A series of aminomethylated derivatives of magnolol were synthesized under the aromatic Mannich reaction. In-vitro testing for diphenyl-p-picrylhydrazyl (DPPH) scavenging and chemiluminescence assays in whole cell models revealed that the pyrrolidyl-containing magnolols (2b  (5,5′-diallyl-3-(pyrrolidin-1-ylmethyl)-biphenyl-2,2′-diol), 3a  (5,5′-diallyl-3,3′-bis-(pyrrolidin-1-ylmethyl)-biphenyl-2,2′-diol) and 4c  (5,5′-diallyl-3-(morphorin-4-ylmethyl)-3′-(pyrrolidin-1-ylmethyl)-biphenyl-2,2′-diol)) displayed promising free radical scavenging effects as compared with magnolol. The results from compound 4c indicated that the naturally occurring component was suitable to be a lead compound toward promising antioxidants.
Tocolytic activity of formoterol against premature delivery in mice
Authors: Shinkai N , Takasuna K , Takayama S
Published: January 2003

The tocolytic activity of formoterol (eformoterol), a long-acting potent β2-adrenoceptor agonist, was assessed in pregnant mice, with determination of uterine effects on the 15th and 16th days of gestation. For examination in the lipopolysaccharide-induced premature delivery model, osmotic pumps filled with formoterol or saline solution were implanted subcutaneously under the back skin. The mice were sacrificed 18–20 h thereafter, and the numbers of fetuses in the uteri and the newborn were counted. The uteri, amniotic membranes and placenta were also rapidly removed for determination of IL-6 concentrations. Furthermore, the effect of formoterol on IL-6 secretion from mouse amnion cells was determined. Formoterol and ritodrine inhibited contraction responses of isolated mouse uteri and their intravenous administration resulted in lowered uterine motility. Lipopolysaccharide (30 μg mL−1/mouse) induced premature delivery, attributable to increased IL-6 secretion, and formoterol suppressed this. Doses of 5–500 μg/mouse thus reduced the number of prematurely delivered newborn, and 50 μg/mouse also depressed IL-6 secretion. On histopathologic analysis, the marked oedema and slight haemorrhage in the mouse cervix induced by lipopolysaccharide were reduced by administration of the β2-adrenoceptor agonist. Neither formoterol (10−7–10−5  m) nor ritodrine (10−7–10−5  m) influenced spontaneous secretion of IL-6 in amnion cells. However, at 10−7 and 10−5  m, and 10−6 and 10−5  m, respectively, they inhibited lipopolysaccharide-induced IL-6 secretion and this inhibitory effect was competitively reversed by addition of ICI-118,551 (β2-adrenoceptor antagonist), but not atenolol (β1-adrenoceptor antagonist). These findings strongly suggest that formoterol can suppress premature delivery mediated by its actions on IL-6 secretion.
Inhibition of urinary bladder motility by a spinal action of U-50488H in rats
Authors: Gotoh Akinobu , Goto Kazuhiro , Sengoku Atsushi , Shirakawa Toshiro , Akao Yoshinobu , Fujisawa Masato , Okada Hiroshi , Arakawa Soichi , Sasaki Hiroshi , Kamidono Sadao
Published: January 2003

We examined the effect of a kappa agonist, U-50488H, upon the bladder motility of anaesthetized rats. The frequency of distension-induced rhythmic bladder contractions was reduced by the intravenous (10 mg kg−1) or intrathecal (10–100 μg) administration of U-50488H. The effect of intravenous U-50488H was inhibited by pre-treatment with nor-binaltorphimine (10 mg kg−1, s.c.). The inhibition of bladder contractions by intrathecal U-50488H (30 μg) was eliminated with the concomitant use of nor-binaltorphimine (10 mg kg−1, s.c.), and diminished by reserpine (4 mg kg−1, i.p.), yohimbine (10 μg, i.t.) or methysergide (20 μg, i.t.). The amplitude of bladder contractions induced by an electrical stimulation of the pontine micturition centre was not inhibited by intrathecal U-50488H (30 and 100 μg). These results suggested that a kappa agonist could inhibit micturition reflex as well as other opioids, and at least part of the inhibition was due to the diminishment of bladder sensation based on the activation of the descending monoaminergic systems through the spinal kappa-opioid receptors.
Rapid inhibition of the contraction of rat tail artery by progesterone is mediated by inhibition of calcium currents
Authors: Zhang Meili , Benishin Christina G , Pang Peter K T
Published: January 2003

Progesterone induced rapid relaxation of KCl-contracted tail artery helical strips from rats. The effect was dose dependent, with an IC50 (inhibitory concentration which produces 50% of the maximal response) of 8.9 μm progesterone. The actions of progesterone were not blocked by bicuculline, indicating that in this tissue the non-genomic actions of progesterone were not mediated via a γ-aminobutyric acid (GABA)-A receptor. Fura-2 was used to measure intracellular calcium levels ([Ca2+]i) in isolated vascular smooth muscle cells (VSMC). Incubation of cultured VSMC for 15 min with progesterone (10 μm) resulted in an inhibition of the KCl-induced [Ca2+]i increase. The whole-cell patch-clamp technique was used to examine Ca2+-channel currents in the membrane of isolated VSMC. Progesterone suppressed the L-type Ca2+-channel currents in cells held at a potential of − 40 mV. The effects of progesterone were quickly reversed by washout in all three experimental protocols suggesting that these effects on vascular tissues are non-genomic. The correlation of the effects on all these preparations, their time course and reversibility suggested that the rapid relaxation of the rat tail artery induced by progesterone is mediated at least in part by inhibition of L-type calcium channels, leading to inhibition of calcium responses in the VSMC of this tissue.
Function of pectoral fins in rainbow trout: behavioral repertoire and hydrodynamic forces
Authors: Drucker Eliot G. , Lauder George V.
Published: January 2003

Salmonid fishes (trout, salmon and relatives) have served as a model system for study of the mechanics of aquatic animal locomotion, yet little is known about the function of non-axial propulsors in this major taxonomic group. In this study we examine the behavioral and hydromechanical repertoire of the paired pectoral fins of rainbow trout Oncorhynchus mykiss, performing both steady rectilinear swimming and unsteady maneuvering locomotion. A combination of kinematic analysis and quantitative flow visualization (using digital particle image velocimetry) enables identification of the propulsive roles played by pectoral fin motions. During constant-speed swimming (0.5 and 1.0 body length s-1), the pectoral fins remain adducted against the body. These fins are actively recruited, however, for a variety of maneuvering behaviors, including station holding in still water (hovering), low-speed(i.e. non-fast-start) turning, and rapid deceleration of the body during braking. Despite having a shallow pectoral-fin base orientation (the plesiomorphic teleost condition), trout are capable of rotating the fin base over 30° during maneuvering, which affords the fin an impressive degree of kinematic versatility. When hovering, the pectoral fins are depressed beneath the body and twisted along their long axes to allow anteroposterior sculling. During turning and braking, the fins undergo spanwise rotation in the opposite direction and exhibit mediolateral and dorsoventral excursions. Water velocity fields and calculated momentum flows in the wake of the pectoral fins reveal that positive thrust is not generated during maneuvering, except during the retraction half-stroke of hovering. Relatively large laterally directed fluid force (mean 2.7 mN) is developed during turning, whose reaction powers yawing rotation of the body (4-41° s-1). During deceleration, the wake-force line of action falls below the center of mass of the body, and this result supports a long-standing mechanical model of braking by fishes with ventrally positioned paired fins. Despite its traditional categorization as a propulsor of limited functional importance, the salmoniform pectoral fin exhibits a diverse locomotor repertoire comparable to that of higher teleostean fishes.
Corneal power and underwater accommodation in great cormorants(Phalacrocorax carbo sinensis)
Authors: Katzir Gadi , Howland Howard C.
Published: January 2003

In great cormorants (Phalacrocorax carbo sinensis), corneal refractive powers, determined by photokeratometry, ranged between 52.1 diopters (52.1 D) and 63.2 D. Photorefractive reflexes, determined by infrared video photorefraction, indicated that in voluntary dives the cormorants accommodate within 40-80 ms of submergence and with myopic focusing relative to the photorefractor attained when prey was approximately one bill length from the plane of the eye. Underwater, the pupils were not constricted and retained diameters similar to those in air. These results support previously reported capacities of lenticular changes in amphibious birds yet do not fully correspond with earlier reports in terms of the coupling of iris constriction with accommodation, and time course.
Requirement of Ca2+ on activation of sperm motility in euryhaline tilapiaOreochromis mossambicus
Authors: Morita M. , Takemura A. , Okuno M.
Published: January 2003

Euryhaline tilapia Oreochromis mossambicus acclimates to the external spawning environment by modulating its mechanism for regulating sperm motility. Adaptation of sperm was performed by acclimating fish in various environments. In this paper, regulatory mechanisms of freshwater-acclimated tilapia were studied in detail. Tilapia sperm motility was vigorous in hypotonic conditions and decreased with increasing osmolality. Sperm motility was reduced in hypotonic conditions when extracellular Ca2+ was chelated; however, extracellular Ca2+ was not a major factor for motility activation since sperm were motile even when extracellular Ca2+ levels were nominally depleted by EGTA. The Ca2+indicator, fluo 3, showed that intracellular [Ca2+] increased on motility activation independently of extracellular [Ca2+],accompanied by swelling of the sperm neck region called the sleeve structure. Intracellular [Ca2+] was not increased under hypertonic conditions,in which sperm were immotile, even on addition of extracellular Ca2+. It is possible that Ca2+ is stored in the neck region. Demembranated sperm were reactivated in the presence of Ca2+, but cAMP failed to reactivate the motility. Furthermore, we detected phosphorylation and dephosphorylation of three proteins at serine and threonine residues on motility activation. It is likely that hypotonic shock causes an increase in intracellular [Ca2+] that activates motility activation via phosphorylation of some flagellar proteins.
Characterization of ryanodine receptor and Ca2+-ATPase isoforms in the thermogenic heater organ of blue marlin (Makaira nigricans)
Authors: Morrissette Jeffery M. , Franck Jens P. G. , Block Barbara A.
Published: January 2003

A thermogenic organ is found beneath the brain of billfishes(Istiophoridae), swordfish (Xiphiidae) and the butterfly mackerel(Scombridae). The heater organ has been shown to warm the brain and eyes up to 14°C above ambient water temperature. Heater cells are derived from extraocular muscle fibers and express a modified muscle phenotype with an extensive transverse-tubule (T-tubule) network and sarcoplasmic reticulum (SR)enriched in Ca2+-ATPase (SERCA) pumps and ryanodine receptors(RyRs). Heater cells have a high mitochondria content but have lost most of the contractile myofilaments. Thermogenesis has been hypothesized to be associated with release and reuptake of Ca2+. In this study,Ca2+ fluxes in heater SR vesicles derived from blue marlin(Makaira nigricans) were measured using fura-2 fluorescence. Upon the addition of MgATP, heater SR vesicles rapidly sequestered Ca2+. Uptake of Ca2+ was thapsigargin sensitive, and maximum loading ranged between 0.8 μmol Ca2+ mg-1 protein and 1.0μmol Ca2+ mg-1 protein. Upon the addition of 10 mmol l-1 caffeine or 350 μmol l-1 ryanodine, heater SR vesicles released only a small fraction of the loaded Ca2+. However, ryanodine could elicit a much larger Ca2+ release event when the activity of the SERCA pumps was reduced. RNase protection assays revealed that heater tissue expresses an RyR isoform that is also expressed in fish slow-twitch skeletal muscle but is distinct from the RyR expressed in fish fast-twitch skeletal muscle. The heater and slow-twitch muscle RyR isoform has unique physiological properties. In the presence of adenine nucleotides, this RyR remains open even though cytoplasmic Ca2+ is elevated, a condition that normally closes RyRs. The fast Ca2+sequestration by the heater SR, coupled with a physiologically unique RyR, is hypothesized to promote Ca2+ cycling, ATP turnover and heat generation. A branch of the oculomotor nerve innervates heater organs, and, in this paper, we demonstrate that heater cells contain large `endplate-like'clusters of acetylcholine receptors that appear to provide a mechanism for nervous control of thermogenesis.
Vacuolar-type proton pump in the basolateral plasma membrane energizes ion uptake in branchial mitochondria-rich cells of killifishFundulus heteroclitus, adapted to a low ion environment
Authors: Katoh Fumi , Hyodo Susumu , Kaneko Toyoji
Published: January 2003

We examined the involvement of mitochondria-rich (MR) cells in ion uptake through gill epithelia in freshwater-adapted killifish Fundulus heteroclitus, by morphological observation of MR cells and molecular identification of the vacuolar-type proton pump (V-ATPase). MR cell morphology was compared in fish acclimated to defined freshwaters with different NaCl concentrations: low (0.1 mmol l-1)-, mid (1 mmol l-1)-and high (10 mmol l-1)-NaCl environments. MR cells, mostly located on the afferent-vascular side of the gill filaments, were larger in low- and mid-NaCl environments than in the high-NaCl environment. Electron-microscopic observation revealed that the apical membrane of well-developed MR cells in low- and mid-NaCl environments was flat or slightly projecting, and equipped with microvilli to expand the surface area exposed to these environments. On the other hand, in the high-NaCl environment, the apical membrane was invaginated to form a pit, and MR cells often formed multicellular complexes with accessory cells, although the NaCl concentration was much lower than that in plasma. We cloned and sequenced a cDNA encoding the A-subunit of killifish V-ATPase. The deduced amino acid sequence showed high identity with V-ATPase A-subunits from other vertebrate species. Light-microscopic immunocytochemistry, using a homologous antibody, revealed V-ATPase-immunoreactivity in Na+/K+-ATPase-immunoreactive MR cells in low-NaCl freshwater, whereas the immunoreactivity was much weaker in higher NaCl environments. Furthermore, immuno-electron microscopy revealed V-ATPase to be located in the basolateral membrane of MR cells. These findings indicate that MR cells are the site responsible for active ion uptake in freshwater-adapted killifish, and that basolaterally located V-ATPase is involved in the Na+ and/or Cl- absorbing mechanism of MR cells.
Involvement of Gq/11 in signal transduction in the mammalian vomeronasal organ
Authors: Wekesa Kennedy S. , Miller Stephanie , Napier Audrey
Published: January 2003

Social behaviors of most mammals are profoundly affected by pheromones. Pheromones are detected by G-protein coupled receptors in the vomeronasal organ (VNO). To investigate the role of Gαq/11 in vomeronasal signal transduction pathways, microvillar membranes from murine VNO were prepared. Incubation of such membranes from prepubertal females with adult male urine results in an increase in production of inositol-(1,4,5)-trisphosphate (IP3). This stimulation is mimicked by GTPγS, blocked by GDPβS and is tissue specific. Furthermore, use of bacterial toxins such as pertussis that lead to ADP-ribosylation of the G-protein alpha subunits of Go and Gi2 do not block the increase in IP3 levels but U-73122, a PLC inhibitor, blocks the production of IP3. Studies with monospecific antibodies revealed the presence of three G-proteins, Gαo, Gαi2and Gαq/11-related protein, in vomeronasal neurons,concentrated on their microvilli. Our observations indicate that pheromones in male urine act on vomeronasal neurons in the female VNO via a receptor-mediated, Gαq/11-protein-dependent increase in IP3 levels.
Odor localization requires visual feedback during free flight inDrosophila melanogaster
Authors: Frye Mark A. , Tarsitano Michael , Dickinson Michael H.
Published: January 2003

Adult fruit flies follow attractive odors associated with food and oviposition sites through widely varied visual landscapes. To examine the interaction between olfactory and visual cues during search behavior, we recorded three-dimensional flight trajectories as individuals explored controlled sensory landscapes. When presented with the source of an attractive odor invisibly embedded in the floor of a 1 m arena, flies spend most of their time hovering back and forth over the source when flying within a randomly textured visual background but fail to localize the source when searching within a uniform white surround. To test whether flies are associating unique features of the visual background with the strength of odor cues, we flew them within arenas containing evenly spaced vertical stripes. Flies readily localized the odor when flying within visual landscapes lacking azimuthal landmarks provided that vertical edges were present. Flies failed to localize odor when flying within a background pattern consisting of horizontal stripes. These results suggest that, whereas flies do not require spatially unique visual patterns to localize an odor source, they do require visual feedback generated by vertical edges. Quantitative shifts in several components of flight behavior accompanied successful odor localization. Flies decrease flight altitude, turn more often and approach visually textured walls of the arena near an odor source. A simple model based on the statistics of flight behavior supports the hypothesis that a subtle influence on these behaviors is sufficient to lead a fly to its food.
Do familiar landmarks reset the global path integration system of desert ants?
Authors: Collett M. , Collett T. S. , Chameron S. , Wehner R.
Published: January 2003

It is often suggested that animals may link landmark memories to a global coordinate system provided by path integration, thereby obtaining a map-like representation of familiar terrain. In an attempt to discover if desert ants form such associations we have performed experiments that test whether desert ants recall a long-term memory of a global path integration vector on arriving at a familiar food site. Ants from three nests were trained along L-shaped routes to a feeder. Each route was entirely within open-topped channels that obscured all natural landmarks. Conspicuous artificial landmarks were attached to the channelling that formed the latter part of the route. The homeward vectors of ants accustomed to the route were tested with the foodward route,either as in training, or with the first leg of the L shortened or extended. These ants were taken from the feeder to a test area and released, whereupon they performed a home vector. If travelling the latter part of a familiar route and arriving at a familiar food site triggers the recall of an accustomed home vector, then the home vector should be the same under both test conditions. We find instead that the home vector tended to reflect the immediately preceding outward journey. In conjunction with earlier work, these experiments led us to conclude in the case of desert ants that landmark memories do not prime the recall of long-term global path integration memories. On the other hand, landmark memories are known to be linked to local path integration vectors that guide ants along a segment of a route. Landmarks thus seem to provide procedural information telling ants what action to perform next but not the positional information that gives an ant its location relative to its nest.