Characterization of two components of the N-like,high-threshold-activated calcium channel current in differentiated SH-SY5Y cells

Retinoic acid differentiated SH-SY5Y cells exhibit only a high-threshold-activated (–30 to –20 mV) whole cell calcium channel current. When barium was used as the charge carrier, the high-threshold-activated current showed bi-exponential inactivation kinetics during a 500 ms voltage step from –90 to +10mV. The time constants of inactivation were approximately 75 and 750 ms. The fast inactivating component was more sensitive than the slow inactivating component to steady-state inactivation at depolarized holding potentials. The calcium channel current was inhibited by externally applied cadmium (10–300 M) and gadolinium (10–30 M) as well as by high concentrations of nickel and cobalt, Conus toxin (1 M) irreversibly blocked the calcium channel current. However, the dihydropyridine agonist, BAY K 8644 (3–10 M) and antagonists, nifedipine (3–10 M) and nimodipine (10 M) did not affect either component of the calcium channel current. Agents which blocked the calcium channel current did not exhibit any selectivity for the fast inactivating over the slow inactivating component of the current. These results indicate that whilst the calcium channel current recorded in differentiated SH-SY5Y cells can be classified on the basis of the blocking agents as being of the N type, the current shows more than one form of inactivation.     

Differential modulating effects of retinoic acid on interferon antiviral activity

Summary The effect of retinoic acid (RA) on the antiviral activity of interferons (IFNs) and in the U 937 and WISH cells was examined to ascertain whether or not RA could reduce the effectiveness of IFN-induced resistance to viral infection. Our results indicate that in the U 937 cells, RA (0.1–1.0 µM) had neither enhancing nor suppressive effect on the antiviral activity of IFN- or against the Semliki Forest virus (SFV). However, in the WISH cells, RA had different effects on IFNs and . Thus, while RA (0.1–50 µM) invariably suppressed the activity of IFN-, it enhanced the action of IFN- at low dose (0.1–1.0 µM) but became suppressive at higher concentrations ( 10 µM). Furthermore, higher antiviral activity was consistently obtained when RA (0.1–10 µM) was added prior to either IFN- or IFN- comparing to cultures with IFN alone. In addition, direct correlation between antiviral activity and the amplitude of 2–5 oligoadenylate (A) synthetase activity was not observed. These results suggest that modulation of IFN antiviral activity by RA varies with different systems and is dependent on the sequence of treatment.     

Activation of α1-adrenoceptors modulates the inwardly rectifying potassium currents of mammalian atrial myocytes

The selective ₁-adrenergic agonist methoxamine (10^–4–10^–3M), in the presence of propranolol (10^–6M), can reduce both the inwardly rectifying K⁺ background current (I _K1) and the muscarinic cholinergic receptor-activated K⁺ current (I _{K, ACh}) in rabbit atrial myocytes resulting in action potential prolongation during the final phase of repolarization and a depolarization of the resting membrane potential. The reduction of these K⁺ current(s) by ₁-adrenoceptor stimulation was insensitive to pre-treatment of artial myocytes with pertussis toxin (0.15–0.5 g/ml) and was irreversible following intracellular dialysis with the non-hydrolysable guanosine triphosphate (GTP) analogue, Gpp(NH)p (1–5×10^–3M). Neither the protein kinase C (PKC) inhibitors, 1-(5-isoquinolinesulphonyl)-2-methylpiperoxine (H-7) (5×10^–5M) and staurosporine (1×10^–7M), nor downregulation of PKC by prolonged phorbol ester exposure (5×10^–7M, for 7–8 h) had an effect on the ₁-adrenergic modulation of this K⁺ current. Under cellattached patch-clamp conditions, bath application of methoxamine reversibly decreased acetylcholine-induced single-channel activity, thus confirming the observed reduction of the ACh-induced current under whole-cell voltage clamp. These results demonstrate that the ₁adrenoceptor, once activated, can reduce current through two different inwardly rectifying K⁺ channels in rabbit atrial myocytes. These current changes are mediated via a pertussis toxin-insensitive GTP-binding protein, and do not appear to involve the activation of PKC.     

Ion-induced release of LHRH,TRH and α-MSH from hypothalamic synaptosomes and its inhibition by vinblastine

Homogenates of rat hypothalamic tissue were fractionated by means of discontinuous sucrose density gradient centrifugation. Immunoreactive luteinizing hormone releasing hormone (LHRH), thyrotropin releasing hormone (TRH), and -melanocyte stimulating hormone (-MSH) were found to be concentrated in the synaptosome-enriched fraction. This fraction was suspended in 0.32 M sucrose and the release of the three peptides was investigated. After incubation, the synaptosomes were re-isolated by ultrafiltration, and the concentration of each peptide in the ultrafiltrate was determined by radioimmunoassay. When the synaptosomal fraction was incubated at 30° C in 0.32 M sucrose containing either 60 mM K⁺-2 mM Ca²⁺ or 140 mM Na⁺ alone a release of LHRH, TRH, and -MSH occurred. Of the total content 30–50% of LHRH but only about 10% of TRH and -MSH was releasable. When the synaptosome preparation was preincubated for 30 min at 30°C with 10^–4 M vinblastine. K⁺- as well as Na⁺-induced release of LHRH, THR, and -MSH was inhibited, and the stimulatory effect of each cation was almost totally blocked by preincubation with 5×10^–4 and 10^–3 M vinblastine. The inhibitory action of vinblastine (5×10^–4 M) did not affect the oxidation of glucose to CO₂ by the synaptosomes. The results of the present investigation demonstrate that synaptosome-enriched fractions of hypothalamic origin are more stable with respect to LHRH, TRH, and -MSH release during incubation in isotonic sucrose than they are in ionic solutions, and that the peptides are released by a vinblastine-sensitive mechanism.Supported by grants from the National Institute of Arthritis, Metabolism, and Digestive Diseases (AMO 1237), the National Institute of Child Health and Human Development (HDO8672), and the National Institutes of Health contract (5-P17-HL1487-06)Supported by Grant No. 512-6951 from the Danish Medical Research Council     

Potentiation of a metabotropic glutamatergic response following NMDA receptor activation in rat hippocampus

Interactions between metabotropic glutamate andN-methyl-D-aspartate (NMDA) receptor-mediated responses were investigated in hippocampal CA3 cells using the single-electrode voltage-clamp method. Bath application (2.5–10 M, 30 s) or iontophoresis of 1-amino-cyclopentyl-trans-1S, 3R-dicarboxylate (ACPD), a selective agonist for metabotropic glutamate receptors, resulted in an inward current associated with a decrease in membrane conductance. Following transient bath application of NMDA (5–10 M, 30–60 s), the ACPD-induced inward current was potentiated for a period of up to 25 min (by 61±8% with bath application, by 32±15% with iontophoresis). Transient application of NMDA did not result in a potentiation of ionotropic RS--amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) or metabotropic muscarinic responses. ACPD responses were not potentiated following transient AMPA application. Intracellular buffering of calcium with tetrapotassium bis(O-aminophenoxy)-ethane-N,N,N,N-tetraacetic acid (BAPTA) prevented potentiation by NMDA in all cells. Bath application of arachidonic acid did not mimic the NMDA-induced potentiation. These results demonstrate that activation of NMDA receptors can specifically induce a long-lasting potentiation of a metabotropic glutamatergic response in hippocampal CA3 pyramidal cells. The characterization of this interaction may contribute to the elucidation of the physiological significance of metabotropic glutamate receptors.     

On the mechanism of β-adrenergic regulation of the Ca channel in the guinea-pig heart

Dose-response relations for the increase in the amplitude of Ca current (I _Ca) on external application of isoprenaline (ISP) and internally applied cyclic AMP (cAMP) or catalytic subunit of cAMP-dependent protein kinase (C subunit) were established in single ventricular cells of the guinea pig. An intracellular dialysis technique was used. The threshold concentration was for ISP 10^–9 M, for cAMP 3 M (pipette concentration to which 10^–5 M 3-isobutyl-1-methylxanthine was added) and for C subunit around 0.4 M (pipette concentration). The concentrations for the half-maximal effect were 3.7×10^–8 M (ISP), 5.0 M (cAMP) and 0.95 M (C subunit) and for the maximum effect 10^–6 M (ISP), 15–20 M (cAMP) and 3–4 M (C subunit). For all three agents the maximum increase in the Ca current density was similar (a factor of 3–4), suggesting that they converge on the same site of the Ca channel. Accordingly, the effects of cAMP and C subunit onI _Ca were non-additive to those of ISP. From these data the relationship both between concentrations of ISP and cAMP and between those of cAMP and active C subunit in terms of their effects onI _Ca could be estimated and were compared with those obtained in broken cell preparations.A competitive inhibitor of phosphorylation, 5-adenylyl-imidodiphosphate (5 mM), greatly reduced the effects of ISP and C subunit onI _Ca. Cell dialysis with 3 mM adenosine-5-(-thio)-triphosphate, which produces a dephosphorylationresistant phosphorylation, markedly potentiated the effects of ISP and cAMP onI _Ca.The results support the hypothesis that phosphorylation of a protein within, or close to, the Ca channel by cAMP-dependent protein kinase is the mechanism of -adrenergic stimulation.This work was supported by the Deutsche Forschungsgemeinschaft, SFB 38 (membranforschung), Projekt G, and H0579/6-2     

Dose-Dependent Effects and Specificity of Action of Antibodies to Endogenous Regulators in Ultralow Doses

Atopy parameters (total IgE, skin prick test, and peripheral blood eosinophil count) in children with atopic bronchial asthma depend on the number of glutathione-S-transferase M1 mutant alleles in the genotype and on family history of asthma.Translated from Byulleten Eksperimentalnoi Biologii i Meditsiny, Vol. 138, No. 11, pp. 520–522, November, 2004     

The effect of certain phenothiazine derivatives on respiratory phosphorylation in the cardiac muscle of the rabbit

Summary Phenothiazine derivatives, mepazine and promazine, when added to homogenates of cardiac muscle of the rabbit in a concentration of 0.8·10^–3M, cause a rise in the efficacy of oxidative phosphorylation, increasing the P and the P: O coefficient. In a 1.2·10^–3M, concentration of mepazine and promazine P is reduced, though to a lesser degree than O₂, the P: O coefficient remaining slightly above the normal level.A 0.8·10^–3M phenergan concentration uniformly reduces both respiration and phosphorylation. With a further rise of the phenergan concentration phosphorylation decreases more sharply than respiration. High concentrations of mepazine, phenergan and promazine (1.6·10^–3M) sharply depress phosphocreatine formation and cause a decrease of P: O. The phenothiazine derivatives neither depress creatine kinase nor activate adenosinetriphosphatase.(Presented by Active Member AMN SSSR S. E. Severin) Translated from Byulleten Èksperimental'noi Biologii i Meditsiny Vol. 49, No. 4, pp. 60–63, April, 1960     

Control of quantal transmitter release at frog's motor nerve terminals

Motor terminals on the cutaneous pectoris muscle of the frog were depolarized by current pulses through the recording macro-pathch-clamp electrode and the resulting quantal release was measured (excitation blocked with TTX). Above a threshold release increased very steeply with depolarization until saturation was approached. The dependence of release on duration of depolarization was even steeper: doubling pulse duration often produced more than 100-fold release (early facilitation) Distributions of delays of quantal release after the depolarization pulse were determined for wide ranges of depolarizations and pulse durations. The shape of these distributions was little affected by large changes in average release; increasing the temperature from 0°C to 10°C about halved the time scale of the distributions. Lengthening the depolarization from 0.5 to 6 ms produced a latency shift: the distributions of delays were shifted by almost the increase in pulse duration. At 5–6 ms pulse duration a few releases occurred during the final millisecond of the pulse. It is suggested that the time course of the phasic release is not controlled by the time course of changes in intracellular calcium concentration, but by an activator which is produced about proportional to supra-threshold pulse amplitude and duration, and that this activator effects release with a cooperativity of 6–7. An additional depolarization produced repressor is responsible for the minimum delay.Supported by the Deutsche Forschungsgemeinschaft     

The influence of ionic strength upon relaxation from rigor induced by flash photolysis of caged-ATP in skinned murine skeletal muscle fibres

The influence of ionic strength upon relaxation kinetics from rigor in skinned murine extensor digitorum longus (EDL) skeletal muscle fibres was examined using photolysis of caged-ATP at low Ca²⁺. The ionic strength was adjusted with either KMeSO₃ or ethylene glycol bis-(-aminoethyl ether)N,N,N,N-tetraacetic acid, dipotassium salt (K₂EGTA) in the range of /2=65–215 mM, or I.E. 49–194 mM, where I.E. denotes ionic equivalent. Following rigor development at a/2 of 165–215 mM (I.E. 144–194 mM), the liberation of approximately 0.5 mM ATP resulted in an initial 6-to 10-ms detachment phase with a decline in force of approximately 10–20% followed by a 10-to 30-ms reattachment with up to a 60% increase compared to the corresponding rigor level and a final detachment leading to complete relaxation. Interestingly, when similar ATP concentrations were liberated at lower ionic strengths between a /2 of 65 mM and 110 mM (I.E. 60–100 mM), the initial detachment phase was shortened and force decreased by only approximately 5–10%, while the following reattachment phase was lengthened and led to an increased steady-state force of approximately 20–80% without final relaxation. ATP-induced detachment and subsequent reattachment were mainly determined by the currently present ionic strength and were relatively independent of the preceding rigor state which had been developed at higher or lower ionic strengths. The effects of phosphate and apyrase on the force transient suggest that reattachment of ADP- binding crossbridges may contribute to the increase in tension at high and even more at low ionic strengths. The study shows that the kinetics of initial fast relaxation and subsequent redevelopment of force following flash photolysis of similar ATP concentrations are markedly modified by the ionic strength in the narrow range of between 65 mM and 215 mM.     

The effects of calcium and calcium channel blockers on sodium pump

The effects of 10 mM Ca²⁺ and Ca²⁺ channel blockers verapamil, diltiazem and flunarizine on the ouabain-sensitive electrogenic Na⁺, K⁺ pump activity of mouse diaphragm muscle fibres enriched with Na⁺ were compared with the changes in cytosolic [Ca²⁺]. The electrogenic Na⁺ pump activity produced by adding K⁺ to muscles previously bathed for 4 h in a K⁺-free, 2-mM [Ca²⁺] solution increased the resting membrane potential by about 18 mV. This hyperpolarization was completely inhibited after 10 min incubation in 10 mM Ca²⁺. Verapamil 10^–5M, 10^–5M diltiazem and 10^–7 M flunarizine effectively prevented the effect of elevated [Ca²⁺]. At these concentrations, these drugs did not affect the K⁺-induced hyperpolarization. In mouse diaphragm, the basal cytosolic [Ca²⁺] measured by the fluorescent indicator 1-[2-(5-carboxyoxazol-2-yl)-6-aminobenzofuran-5-oxy]2-(2-amino 5-methylphenoxy) ethane-N,N,N,N-tetraacetic acid acetoxymethyl ester (fura-2/AM) was 261±6 nM. After 4 h in a Liley K⁺-free, 2 mM [Ca²⁺] solution, the cytosolic [Ca²⁺] increased to 314±28 nM. Increase in [Ca²⁺] from 2 to 10 mM caused a twofold increase of cytosolic [Ca²⁺] to 637±26 nM. This rise was, like the Ca²⁺-induced inhibition of electrogenic pump, prevented by 10^–5 M verapamil, 10^–5M diltiazem and 10^–7 M flunarizine. The results suggest that substances which block Ca²⁺ entry into the cell prevent the Ca²⁺ induced inhibition of the Na⁺ pump.     

Ability of L-histidine to decrease desensitization of the myometrium to epinephrine

Experiments were performed with 62 longitudinal strips of the uterine horns from 10 nonpregnant rats. The ability of continuously infused epinephrine in high concentration (10^–6 g/ml, 30 min) to suppress spontaneous contractions due to activation of -adrenoceptors progressively decreased, which was associated with receptor desensitization. Histidine in a concentration of 3×10^–11 g/ml had no effect, while in concentrations of 3×10^–8, 3×10^–7, and 3×10^–6 g/ml decreased the degree of desensitization. Our results indicate that histidine not only potentiates -adrenoceptor activation, but also prevents the development of desensitization. These data should be taken into account during therapy with -adrenoceptor agonists.Translated from Byulleten Eksperimentalnoi Biologii i Meditsiny, Vol. 138, No. 10, pp. 364–367, October, 2004     

Biochemical characteristics,phage patterns,and O1 factor analysis ofEscherichia coli O1∶K1∶H7∶F11 and O1∶K1∶H−∶F9 strains isolated from patients with urinary tract infections

Biochemical characteristics, O1 antigen factors and phage patterns were examined in 35 urinary O1K1 isolates ofEscherichia coli different in H and F antigen. Fermentation of dulcitol, decarboxylation of ornithine, requirement for nicotinamide, and determination of O1 factor d allowed maximum differentiation. On the basis of these tests the strains could be divided into two major groups which are obviously of different clonal origin. Members of clone 1 represented by serotypes O1K1H7F11 (12 strains) and O1K1H^–F11 (5 strains) were characterized by positive biochemical reactions and absence of O1 antigen factor d. Negative biochemical tests and presence of O1 antigen factor d were shown by strains of clone 2 which were of serotypes O1K1H^–F9 (14 strains) and O1K1H^–F^– (3 strains). Phage patterns are less well correlated with clonal assignment. However, strains of clone 2 were not susceptible to K1-specific phage D and were non-typable with another set of 13 phages.     

Effect of exchange blood transfusion on some indices of skeletal muscle metabolism

After replacement of 85% of the blood volume in healthy dogs and also in animals with transfusion shock the content of the nitrogenous fractions and activity of aspartate and alanine aminotransferases in the skeletal muscles were studied for 7 days. The exchange blood transfusion produced a good therapeutic effect on the animals with transfusion shock. However, the process of flushing of nonprotein substances from the tissues of these animals was much less complete than in healthy animals.Experimental Division, Institute of Hematology and Blood Transfusion, L'vov. (Presented by Academician of the Academy of Medical Sciences of the USSR A. M. Chernukh.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 82, No. 12, pp. 1423–1424, December, 1976.     

Relationship between muscle architectural features and oxygenation status determined by near infrared device

This study tested whether regional differences in oxygenation status could result from differences in muscle fiber architecture. Architectural properties, oxygen supply, and consumption in the medial head of the gastrocnemius muscle (GM) were determined in vivo in six men using B-mode ultrasound and functional near infrared (NIR) imaging devices. Fascicle length, fascicle angle, NIR-O₂ saturation (deoxygenated Hb or oxygenated Hb), and NIR-blood volume (sum of deoxygenated and oxygenated Hb) were obtained in the distal and proximal portions of the GM at rest and during contraction. Exercise consisted of 2 min of standing plantar flexion at 1 Hz with an additional load of 50% of each subjects weight. Plantar flexion produced larger decreases (: difference between rest and exercise values) in NIR-O₂ saturation [mean saturation (SD) of 0.14 (0.05) vs 0.07 (0.04) optical density units] and NIR-blood volume [mean saturation (SD) of –0.23 (0.08) vs –0.13 (0.04) optical density units] in the distal compared with the proximal portion (P<0.05 for all comparisons). It also produced larger changes () in fascicle length [mean length (SD) of –16.5 (4.7) vs –8.2 (4.2) mm] and fascicle angle (mean angle (SD) of 10.8 (1.4)° vs 3.9 (2.1)°] in the distal compared with the proximal portion (P<0.05 for all comparisons). There were significant correlations between NIR-O₂ saturation and fascicle length (r=–0.84, P<0.05), and between NIR-O₂ saturation and fascicle angle (r=–0.90, P<0.05), between NIR-blood volume and fascicle length (r=0.91, P<0.05), between NIR-blood volume and fascicle angle (r=–0.85, P<0.05). In conclusion, the plantar flexion exercise produced regional differences in oxygenation status consistent with regional differences in muscle architecture.     

Synthesis of α-fetoproteinin vitro by human hepatocytes,singly and in microcolonies

By a combination of microelectrophoresis and precipitation in polyacrylamide gel, -fetoprotein (-FP) produced by single hepatocytes and by microcolonies of hepatocytes was determined. Liver cells from 6–13-week-old human fetuses were cultivatedin vitro for 2–5 days. -FP was found to be produced in amounts of between 70 and 800 pg per cell by 23 of 28 single hepatocytes and by 89 of 91 microcolonies consisting of 2 to 35 cellsLaboratory of Immunochemistry and Diagnosis of Tumors, N. F. Gamaleya Institute of Epidemiology and Microbiology, Academy of Medical Sciences of the USSR. Laboratory of Human Cytogenetics, Institute of Medical Genetics, Academy of Medical Sciences of the USSR, Moscow. (Presented by Academician of the Academy of Medical Sciences of the USSR L. M. Shabad.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 83, No. 4, pp. 481–484, April, 1977.     

Intrinsic cholinergic excitation in the rat neostriatum: Nicotinic and muscarinic receptors

Summary An in vitro slice technique was employed to study the receptors involved in intrinsic cholinergic excitation in the rat neostriatum. The locally evoked synaptic potentials were suppressed by antinicotinic agents, mecamylamine (10 M), d-tubocurarine (3 M) or hexamethonium (100 M), but not by the antimuscarinic agent atropine (100 M). If the slices were exposed to an acetylcholinesterase (AChE)-inhibitor (paraoxon 1–20 M, physostigmine 0.1–0.5 M), the synaptic potentials were potentiated. The amplitude of the orthodromic population spike increased, and it was further facilitated when the stimulus frequencies were raised from 1–3 Hz to 10–30 Hz. The frequency facilitation following exposure to an AChE-inhibitor was blocked by atropine (1–100 M). Intracellular recording indicated that a slow depolarizing potential caused the frequency potentiation of the orthodromic discharges. Apparently rat neostriatum is similar to cholinergic systems in sympathetic ganglia and spinal Renshaw cells, in that nicotinic receptors mediate fast excitation and muscarinic receptors mediate slow excitation.     

Volume flow,hydraulic conductivity and electrical properties across bovine tracheal epithelium in vitro: Effect of histamine

Volume flow (J _v), potential difference (), shortcircuit current (i ₀) and electrical resistance (R) were measured simultaneously across bovine tracheal epithelium in vitro. Under basal conditions, with no applied hydrostatic or osmotic pressure gradient (P=0, =0), no spontaneousJ _v was observed. was 31±2 mV (lumen negative),i ₀ 161±8 A cm^–2 andR 202±9 cm²,n=50. When a was applied, by adding 20–80 mM sucrose into the medium bathing either the luminal or the serosal side of the tissue, a linear relationship was found between andJ _v toward the lumen or toward the serosa. The apparent hydraulic conductivity (apparentL _p) was 4.6–4.910^–6 cm s^–1 atm^–1. Histamine 10^–4 M did not induce any spontaneousJ _v under basal conditions and had no effect oni ₀ nor onR. However, histamine caused a 100% increase inJ _v elicited by sucrose gradients. It was concluded that histamine exerts a selective action on the hydraulic conductivity of bovine tracheal epithelium. Experiments using H₁-receptors antagonists (diphenhydramine, dimetindene, chloropyramine) and H₂-antagonists (cimetidine, metiamide) or a H₂-agonist (impromidine) showed that the increase ofL _p induced by histamine was mediated via H₂-receptors.Supported by the Swiss National Foundation (SNF), grant no. 3.5880.79     

The venous pump does not affect the indifference point for electrical impedance in humans

We have used regional electrical impedance at 2.5 and 100 kHz over nine body sections (two thoracic, one abdominal, two thigh, two around the knee, and two lower leg) in eight subjects to determine the volume indifference point defined as the level at which fluid volume remained constant independent of body position changes in space. Passive head-up tilt and tilt with activation of the venous muscle pump of the legs were performed in 10° increments from 0 to 60° over 6 min. The impedance changes in relation to 0° were similar for the two frequencies. Over the thorax it increased in proportion to the head-up tilt angle by a mean of 3.8 (range 1.9 to 9.3) (100 kHz) at 60° (P < 0.05), while the abdominal impedance did not change significantly. Over the thigh it decreased with increasing head-up tilt angle by a mean maximum of – 2.3 (range – 9.4 to – 0.4) and over the lower leg by a mean of – 2.7 (range – 6.0 to – 0.8) . There were only marginal changes around the knee, mean – 1.5 (range – 2.3 to – 0.2) (P < 0.05), and no change around the ankle indicating that little or no fluid was accumulated in these regions. Changes in impedance during passive and active head-up tilt did not differ significantly in any but one position: between the greater trochanter and the mid thigh, where during passive tilt it decreased by a mean of – 4.8 (range – 9.4 to – 1.9) , and with activation of the venous pump by a mean of only – 1.2 (range – 1.9 to – 0.4) (P < 0.05). These results indicated that the vascular volume indifference point was positioned between the navel and iliac crest both during the passive and active head-up tilts although during the passive tilt, apparently more fluid was accumulated in the vessels of the thigh.     

Polymorphism in the 3′-untranslated region of the thymidylate synthase gene and sensitivity of stomach cancer to fluoropyrimidine-based chemotherapy

To investigate the relationship between polymorphism in the 3-untranslated region (3-UTR) of the thymidylate synthase (TS) gene and sensitivity of gastric cancer to 5-fluorouracil (5-FU)-based chemotherapy, 106 cases of advanced gastric cancer were analyzed. All patients were treated with 5-FU-based chemotherapy; DNA from peripheral blood leukocytes was obtained before therapy. TS 3-UTR genotypes were detected by PCR-RFLP. Polymorphism in the TS 3-UTR can be classified into three groups according to the presence or absence of a 6 bp nucleotide fragment: the –6/–6 bp, –6/+6 bp and +6/+6 bp groups. The response rate of the –6/–6 bp and –6/+6 bp groups was found to be significantly higher than the +6/+6 bp group. These results show that the presence of the TS 3-UTR 6 bp nucleotide fragment can be correlated with the sensitivity of gastric cancer to 5-FU-based chemotherapy, and that the TS 3-UTR polymorphism profile can be used to guide the choice of 5-FU-based chemotherapy in advanced gastric cancer.