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We analyze a set of three RXTE Target of Opportunity observations of the Galactic microquasar GRS 1915+105, observed on April 2000, during a multi-wavelength campaign. During the three observations, a strong, variable low frequency ($2{-}9$Hz) quasi periodic oscillation (hereafter QPO), often referred to as the ubiquitous QPO, is detected together with its first harmonic. We study the spectral properties of both features, and show that: 1) their frequency variations are better correlated with the soft X-ray flux ($2{-}5$keV), favoring thus the location of the QPO in the accretion disk; 2) the QPO affects more the hard X-rays, usually taken as the signature of an inverse Compton scattering of the soft photons in a corona; 3) the fundamental and its harmonic do not behave in the same manner: the fundamental sees its power increase with the energy up to 40 keV, whereas the harmonic increases up to ~10 keV. The results presented here could find an explanation in the context of the Accretion-Ejection Instability, which could appear as a rotating spiral or hot point located in the disk, between its innermost edge and the co-rotation radius. The presence of the harmonic could then be a signature of the non-linear behavior of the instability. The high-energy (>40 keV) decrease of the fundamental would favor an interpretation where most or all of the quasi-periodic modulation at high energies comes not from the comptonized corona as usually assumed, but from a hot point in the optically thick disk.

Electrogenesis of efficiently propagated action potentials requires synchronized opening of transmembrane Na channels possessing a sodium selectivity-filter, a high-throughput ion-conductance pathway, and voltage-dependent gating functions. These properties of the Na channel have long been the target of molecular analysis. Several toxins and drugs, known to selectively bind to Na channels, have been used as pharmacological tools to investigate Na channel properties either electrophysiologically or chemically. Recent analyses of the protein crystal structure of bacterial voltage-dependent K channels have provided important clues to the identity of mobile structures involved in channel gating. The new information may be applicable to Na channels, and may well require a total revision of our understanding of gating mechanisms of sodium channels. Several experiments challenge the emerging view that channel gating by S6 transmembrane segments is triggered by signals from voltage sensors floating in membrane lipid. Herein, we review the various toxin and drug molecules that affect the gating behavior of Na channels in this new structural framework, by characterizing the binding sites of these toxins, and assessing the pharmacological effects resulting from changes in the structure of the toxin or sodium channel.

Electrogenesis of efficiently propagated action potentials requires synchronized opening of transmembrane Na+ channels possessing a sodium selectivity-filter, a high-throughput ion-conductance pathway, and voltage-dependent gating functions. These properties of the Na+ channel have long been the target of molecular analysis. Several toxins and drugs, known to selectively bind to Na + channels, have been used as pharmacological tools to investigate Na+ channel properties either electrophysiologically or chemically. Recent analyses of the protein crystal structure of bacterial voltage-dependent K+ channels have provided important clues to the identity of mobile structures involved in channel gating. The new information may be applicable to Na+ channels, and may well require a total revision of our understanding of gating mechanisms of sodium channels. Several experiments challenge the emerging view that channel gating by S6 transmembrane segments is triggered by signals from voltage sensors floating in membrane lipid. Herein, we review the various toxin and drug molecules that affect the gating behavior of Na+ channels in this new structural framework, by characterizing the binding sites of these toxins, and assessing the pharmacological effects resulting from changes in the structure of the toxin or sodium channel.

Abstract The model for the 2000 dike intrusion event between Kozushima and Miyakejima volcano, Japan, was reinvestigated. After the sudden earthquake swarm in Miyakejima volcano, a dike intrusion of large volume was detected by the nationwide GPS network (Geonet). The displacements detected with GPS stations over an area with a radius of about 200 km shows a distribution that is consistent with the dike source being located near Miyakejima volcano.

The hydrogel of poly(11-(4‘-cyanobiphenyloxy)undecyl acrylate-co-acrylic acid), poly(11CBA-co-AA), which was comprised of the hydrophobic cross-linking junction zone with the liquid crystalline nature and the hydrated amorphous domain, showed a smectic mesophase transition at 40 °C in the body temperature range. X-ray diffraction study suggests the water transfer from the main chain domain of the liquid crystalline junction zone to the amorphous domain through the smectic transition. The oriented hydrogel fiber showed a drastic shrinkage through this transition, keeping the orientation. Moreover, the mesomorphic behavior of LCG depended on the aqueous milieu. Thus, the present LCG physically cross-linked by the mesomorphic junction could be considered to be an open system of new actuators controllable in the change in the aqueous milieu at ambient conditions.

We previously examined the effects of 0.5 Gy of γ- or X-irradiation on endogenous antioxidative materials, including glutathione, glutathione-related enzymes, superoxide dismutase and catalase in the liver, pancreas and brain of mice. An increase in the antioxidants was observed soon after the irradiation. We also demonstrated that the low-dose irradiation gave suppressive effects on reactive oxygen species (ROS)-related disease models such as acute hepatitis, type I diabetes and Parkinson's disease. These results suggested that the suppression or inhibition of the ROS-related diseases were made through the elevation of the antioxidants. We studied the effects of irradiation (0.5 Gy of γ-ray) reducing the renal oxidative damage in Fe nitrilotri-acetate (NTA) injected mice. We examined transaminase activity, lipid peroxide level and those levels of antioxidants in the mouse. Both transaminase activities and lipid peroxide level accelerated decrease to normal level by the irradiation. The levels of total glutathione content and the activities of its related enzymes were slightly increased in the irradiated group. On the other hand, catalase (CAT) activity was significantly increased by the irradiation. These findings suggested that low-dose irradiation relieved functional disorder in the kidney of mice with ROS-related diseases, probably through enhancing antioxidant, in particular CAT activity.

This retrospective study assessed the treatment of 91 cases of carpal tunnel syndrome in long-term haemodialysis patients. One group of patients underwent an enlargement reconstruction of the flexor retinaculum with synovectomy and the other group was treated with a conventional carpal tunnel release. There were no major changes or differences between the outcomes of the two groups. However, there was an earlier functional recovery of grip strength and a lower recurrence rate in the enlargement plasty with synovectomy group.

This retrospective study assessed the treatment of 91 cases of carpal tunnel syndrome in long-term haemodialysis patients. One group of patients underwent an enlargement reconstruction of the flexor retinaculum with synovectomy and the other group was treated with a conventional carpal tunnel release. There were no major changes or differences between the outcomes of the two groups. However, there was an earlier functional recovery of grip strength and a lower recurrence rate in the enlargement plasty with synovectomy group.

Copolymers composed of various amounts of 4‘-(11-acryloyloxyundecyloxy)biphenyl-4-carboxylic acid (11ABA) and acrylic acid (AA), poly(11ABA-co-AA)s, were synthesized, and their liquid crystalline structures were investigated both in dry and in water-swollen states. Wide- and small-angle X-ray studies revealed that both dry and swollen poly(11ABA-co-AA)s show a liquid crystalline structure, which transforms from smectic C with the bilayer (SmC2) to smectic C with the monolayer (SmC1), when the 11ABA composition, F([11ABA]/([11ABA] + [AA])), decreases from 0.72 to 0.44. The phase diagram of these copolymers was established by changing F and the temperature. It shows that the samples can build up a liquid crystalline structure for F as low as 0.07 at the elevated temperature of 155 °C. The enhanced ordering of the liquid crystalline structure and the thermostability of the copolymers were explained in terms of hydrogen bonding formed between carboxyls of mesogenic side chains and AA.

We report results from multiwavelength observations of the microquasarGRS 1915+105 performed during the 2000 April campaign. This is one ofthe biggest campaigns ever made for this source covering the broadband from radio to γ-rays. Multiwavelength light curves compiledfrom all the data reduced up to date and broad band spectra obtainedwith ASCA and RXTE are presented.

The effects of water on the liquid crystalline structure of the copolymer poly(11-(4‘-cyanobiphenyloxy)undecyl acrylate-co-acrylic acid)s (poly(11CBA-co-AA)s) were investigated. When the molar fraction of 11CBA, F, was higher than 0.26, the copolymers did not dissolve but swelled in water to give the hydrogels, keeping the smectic A ordering. This smectic A phase of the copolymers of F = 0.37 and 0.29 transferred to more organized smectic I ordering by further incorporation of water, while the SmA ordering of the copolymer of F = 0.26 disappeared to give the amorphous state. The role of water and the mechanism for forming a liquid crystalline structure in the hydrogel have been discussed.

Abstract: Background. To clarify the pathophysiological features associated with phosphate depletion in hypophosphatemic (Hyp) mice, we examined the effect of extracellular phosphate on parathyroid hormone (PTH)-stimulated adenosine 3′,5′-cyclic monophosphate (cAMP) production in the proximal convoluted tubules (PCT). Methods. PTH-Stimulated cAMP production and ATP content were determined by radioimmunoassay and luciferin-luciferase chemiluminescence methods, respectively. Results. The level of cAMP stimulated by PTH at an extracellular phosphate concentration of 0.78 mM was lower in the Hyp mice than in normal mice. The PTH-stimulated cAMP production in the Hyp mice was increased when the extracellular phosphate concentration was raised. In contrast, an increase in extracellular phosphate did not affect the PTH-stimulated cAMP production in the normal mice. Although the ATP content of the PCT was not different between the normal and Hyp mice immediately after microdissection, after 60 min of incubation, it had decreased to a greater extent in Hyp mice than in the normal animals. Raising the extracellular phosphate concentration from 0.78 to 2.3 mM prevented the decrease in ATP content in Hyp mice, and the intracellular ATP content then became comparable to that in the normal control. Conclusions. These results suggest that ATP content in the PCT tended to be decreased in Hyp mice by a decreased phosphate supply and that the blunted effect of PTH on cAMP production in these mice is due to ATP depletion.

Copolymers composed of 11-(4‘-cyanobiphenyloxy)undecyl acrylate (11CBA) and acrylic acid (AA), poly(11CBA-co-AA)s, were prepared by changing their molar ratio, and their structures were investigated under various temperatures. From wide- and small-angle X-ray studies, it was found that poly(11CBA) and poly(11CBA-co-AA)s with a mole fraction of 11CBA more than 0.26 showed the smectic A (SmA) phase with a layer spacing (d2) of 46−58 Å, to which the mesogenic moiety of 11CBA attached perpendicularly with a side-by-side spacing of 4.3 Å (d1). The ordering as well as the d2 spacing of the smectic layer increased by incorporating an appropriate amount of AA. At the same time, the isotropic temperature of the copolymer increased with AA content. The enhanced ordering and the thermostability by introducing AA were explained in terms of the cooperative hydrogen interaction between the carboxylic groups of AA.

Abstract. Objective: To study the effect of interleukin (IL)-4 and IL-10 on nitric oxide (NO) production by macrophages.¶ Materials and Methods: Elicited or resident peritoneal macrophages (PMO) and a macrophage cell line Raw264.7 were primed by IL-4 or IL-10 for 6 hours, and were further incubated in the presence of interferon (IFN)-γ and/or lipopolysaccharide (LPS) for 48 hours. NO₂^- accumulation in the supernatant of cultured cells was used as an indicator of NO production and was determined by the standard Griess reaction adapted for microplates. The amount of tumor necrosis factor (TNF)-α in the culture supernatants was determined with a commercially available ELISA kit. The absorbance was measured at 450 nm with a microplate photometer.¶ Results: IL-4 inhibited NO production by murine macrophages of different sources and the macrophage cell line Raw264.7. In contrast, different macrophage populations showed differential responses to IL-10. After stimulation with LPS or IFN-γ, IL-10 suppressed NO production by elicited PMO but enhanced NO production by resident PMO or by Raw264.7. Both IL-4 and IL-10 inhibited the production of TNF-α, which has been shown to play a crucial role in NO production. In the presence or the absence of blocking antibody to TNF-α, IL-10 always enhanced NO production by resident PMO. This result suggests that the inhibition of TNF-α production and the enhancement of NO production by resident PMO stimulated with IL-10 are independent, coexisting events.¶ Conclusions: Factors other than TNF-α have been suspected to influence NO production by macrophages, and this study indicates that IL-10 may be a candidate cytokine for resident PMO.

—The M5.1 event (May 23, 1993) which occurred in one of the most active swarm areas of Japan was preceded by foreshock activity. We obtained precise hypocenters of the foreshock-mainshock-aftershock sequences with a temporary seismic network installed just above the source region twenty days before the mainshock. The foreshocks are very unique in their accelerating activity; the acceleration in the number of foreshocks enabled us to estimate the time of the mainshock with time-to-failure analysis proposed by . Although substantial snow remained in the swarm area, we quickly installed the network because the time-to-failure analysis disclosed that the mainshock was impending. The temporary network provided detailed information on both the temporal and spatial distribution of the foreshock-mainshock-aftershock sequences. Foreshocks started fifty days before the mainshock and were distributed linearly at the base of the seismogenic layer with a length of 5 km and horizontal and vertical widths of about 1 km. The temporal change of the number of foreshocks is approximated by a power law, and the time of the mainshock can be estimated by extrapolating plots of the inverse of the daily number of events. An area of seismic quiescence appeared 40 hours before the mainshock and propagated with a rate of 20 m/hour. The mainshock occurred 2 km westward from the primary foreshock area. It was located at the base of the aftershock region. This process can be interpreted as source nucleation; preslip on the fault prior to the mainshock.

In order to clarify the complex interrelationship between serum calcium, 1,25-dihydroxyvitamin D (1,25(OH)2D), and parathyroid hormone (PTH), and the urinary excretion of cyclic AMP (cAMP) in response to exogenous PTH in pseudohypoparathyroidism (PHP) and related diseases, we investigated 3 patients with parathyroid disorders before and after treatment with 1a-hydroxyvitamin D3 (1a-OH-D3).

In 1974, a 2-year-old boy was diagnosed as having X-linked hypophosphataemic rickets (XLH) because of severe rickets and hypophosphataemia.

It is well known that several hormones and minerals develope daily variation in human blood. Recently the presence of circadian rhythms of blood ionized calcium and serum phosphate concentrations in man reported (Science 213: 672-674, 1981). To clarify the difference in race and age, we examined the serum concentration of minerals such as ionized calcium, inorganic phosphate, total calcium and magnesium, and venous blood pH during 24 hours in three 31 to 40 yeas old Japanese males in good health. Result [1]. There was a correlation between concentration of ionized calcium and blood pH (r = -0.467 p < 0.001), and between concentration of ionized calcium and total calcium (r = 0.366 p < 0.005). [2]. Apparent rhythms of ionized calciums and inorganic phosphate concentrations has been noticed.

A 16-year-old girl with disseminated molluscum contagiosum (MC) was found to have a very low level of serum IgM, elevated levels of IgG and IgA, and a high level of IgE. She had normal numbers of peripheral blood IgM+, IgG+ and IgA+ B-lymphocytes but their terminal differentiation into plasma cells could not be induced by pokeweed mitogen (PWM) in vitro. On the other hand, the patient's T-cells showed normal helper functions in the PWM system and normal interferon (IFN) production in vitro. However, the IgM+ B-cells can be induced to differentiate into IgM secreting cells by Epstein-Barr virus (EBV), suggesting that the genetic mechanism for synthesis of the component immunoglobulin proteins is present. T-cell functions were impaired, as shown by delayed type cutancous hypersensitivity (DTH) and mitogen response. The data suggest that the selective IgM deficiency of the patient is due mainly to defects in B-cells at the terminal differentiation stage, but immunological abnormalities are present in both B and T-cell systems. Neutrophil functions examined were normal. MC was treated by intravenous injection of IFN without any side effects; however, no clinical improvement was achieved.

We performed a prospective, randomized trial to assess the efficacy of endoscopic injection therapy with absolute ethanol in preventing recurrent bleeding in patients with nonbleeding visible vessels in gastric ulcers. During the period of 1990 to 1993, 62 patients who bled were found to have gastric ulcers with nonbleeding visible vessels; all of them were enrolled for this trial. The 62 patients were randomly divided into two groups, which were comparable at entry. In group I (33 patients), we performed endoscopic injection therapy with absolute ethanol. In group II (29 patients), we sprayed the ulcers with 0.1% epinephrine and thrombin. Endoscopic injection therapy with ethanol was performed at the second endoscopy in the patients in both groups who had recurrent bleeding. Among the 33 patients in group I, 4 patients (12.1%) rebled after the initial ethanol injection therapy, whereas 10 of 29 patients (34.5%) rebled in the control group (p < .05). No patients in group I required surgical intervention, and ultimate hemostasis was achieved in all 33 group I patients (100%), indicating that endoscopic ethanol injection therapy achieves ultimate hemostasis and prevents recurrent bleeding inpatients with gastric ulcers and nonbleeding visible vessels (Gastrointest Endosc 1995;42:128-31.)

HUMAN monocytes, preincubated with IFN-γ respond to IL-4 by a cGMP increase through activation of an inducible NO synthase. Here, IL-4 was found to induce an accumulation of cGMP (1 – 3 min) and cAMP (20 – 25 min) in unstimulated monocytes. This was impaired with NOS inhibitors, but also with EGTA and calcium/calmodulin inhibitors. These results suggest that: (1) IL-4 may stimulate different NOS isoforms in resting and IFN-γ activated monocytes, and (2) cAMP accumulation may be partially dependent on the NO pathway. By RT-PCR, a type III constitutive NOS mRNA was detected in U937 monocytic cells. IL-4 also increased the [Ca2+ ]i in these cells. Different NOS may thus be expressed in monocytic cells depending on their differentiation and the signals they receive.

1. Isoprenaline (10 nM to 1 microM) and forskolin (0.6‐100 microM) depolarized single guinea‐pig myocytes studied in vitro. Under voltage clamp both agents caused an inward current to flow. 2. These effects were abolished by propranolol (100 nM) and the beta1‐antagonist metoprolol (100‐200 nM), but not by the beta2‐agonist [corrected] salbutamol (1 microM). 3. The interaction of isoprenaline with forskolin, caffeine or isobutylmethylxanthine (IBMX) on current amplitude was as expected if all of these drugs were causing inward current by increasing intracellular levels of cyclic adenosine monophosphate (cyclic AMP). Low concentrations of forskolin (less than 600 nM) or IBMX (less than 20 microM) potentiated the effect of isoprenaline, whereas isoprenaline caused no further inward current in cells in which high concentrations of forskolin (600 nM‐100 microM) or IBMX (20 microM‐1 mM) were already evoking maximum inward current. 4. Isoprenaline‐induced inward current was reduced 30‐50% by acetylcholine (10‐30 microM). This action of acetylcholine was blocked by atropine (100 nM). 5. The effect of isoprenaline on holding current was critically dependent on temperature. The onset of the current was delayed and its amplitude reduced as the myocyte was cooled from 37 degrees C to ambient temperature (22‐24 degrees C). 6. Isoprenaline‐induced inward current was not affected by the potassium channel blockers barium (2 mM) or tetraethylammonium (TEA; 10‐20 mM). The amplitude of the inward current did not vary as a function of [K+]o. 7. The inward current was not affected by the calcium channel blockers cadmium 1 mM, or nifedipine (10 microM), or when internal calcium was reduced by including EGTA in the recording electrode filling solution. 8. The amplitude of the current was also unaffected by caesium (5 mM), which blocks the hyperpolarization‐activated, non‐specific channel if, or by strophanthidin (10 microM) which blocks the Na+‐K+ pump. It was unchanged by substitution of external chloride by isethionate. 9. The inward current was absent when external sodium was replaced by the impermeant ion tetramethylammonium (TMA). 10. Isoprenaline‐ and forskolin‐induced inward currents were associated with an increase in both membrane chord conductance and noise. The increase in conductance was most readily measured at potentials where the inwardly rectifying potassium channel, iK1, was small, or when iK1 was blocked by the addition of barium (2 mM).(ABSTRACT TRUNCATED AT 400 WORDS)

1. The generation of action potentials elicited from enzymatically dispersed ventricular cells from the frog, Rana catesbeiana, has been shown to be due to the influx of both Na+ and Ca2+. The maximum rate of rise, the amplitude and the duration at 50% repolarization of the action potential were estimated to be 26.4 +/‐ 5.1 V/s (n = 8), 110 +/‐ 2.7 mV (n = 8) and 601 +/‐ 180 ms (n = 8) at 15 degrees C, respectively. 2. Inward Na+ current (INa) was studied in these ventricular cells by the whole‐cell patch clamp technique in a medium where Ca2+ current was eliminated by substituting extracellular Mg2+ for Ca2+ and K+ current was suppressed by applying Cs+ intracellularly. All the voltage clamp experiments were carried out at 4 degrees C. 3. INa elicited by single depolarizing steps from a holding potential (VH) of ‐80 mV had a threshold of ‐50 mV and was maximal at ‐20 mV. Peak currents in normal Ringer solution containing 113.5 mM‐Na+ were of the order of 0.01‐0.02 mA/cm2. Maximum Na+ conductance (gNa) was calculated to be 5.9 mS/cm2. 4. Under normal conditions the reversal potential for INa was determined to be 50 mV, which is close to the value predicted from the Nernst equation. The reversal potential changed by 59 mV per tenfold change in the activity of extracellular Na+ (aNa). 5. The instantaneous relation between INa tail currents and membrane potential is linear, crossing the abscissa at the reversal potential for INa. 6. Reconstructions of INa were made in terms of the parameters of the Hodgkin‐Huxley model for the squid axon, using constants obtained from the frog ventricular cells. 7. The falling phase of INa and the development of inactivation measured by the double‐pulse method could be well fitted by a single‐exponential function. 8. The time course for recovery of INa from inactivation exhibited a single time constant.

Hemolysates from 100,000 people who visited the Kyushu University Hospital and affiliated hospitals during the past 15 years were screened for hemoglobinopathies using electrophoresis on thin-layer starch gel; those exhibiting an abnormality were characterized further on clinical, biochemical, and genetic grounds. Of about 97,000 adult and 3,140 cord blood samples, 29 contained electropho-retically detectable abnormalities in the heterozygous condition. Another 17 samples had quantitative changes in the levels of the minor hemoglobin components. Of the thalassemic conditions, 12 involved β-thalassemia, 3 α-thalassemia, 1 δβ-thalassemia, and l δ-thalassemia. Among 45 carriers of β-thalassemia from 12 families, 5 were noted to have thalassemia intermedia since they exhibited much more severe hemolytic syndromes than those with typical β-tha-lassemia minor. The frequency with which we could detect a structural variant of Hb A in the adults by electrophoresis was one in 3,800 samples. About one in 8,000 carried a β-thalassemia gene.

Changes of weight-average molecular weights (Mw) and the molecular weight distributions in terms of weight fraction (gw) were evaluated in the course of sonication for three nucleic acids in different conformations by the gel permeation chromatography/low angle laser light scattering (GPC/LALLS) method. High Mw samples used were single-stranded poly(uridylic acid), (U)n, double-stranded DNA, and triple-stranded poly(adenylic acid)·2poly(inosinic acid), (A)n·2(I)n, in 0.2−0.1 M NaCl at 0 °C. The experimental gw vs M curves were computer-simulated for different chain-scission mechanisms:  (1) random, (2) midpoint, (3) Gaussian, (4) classical partially random, and (5) newly proposed partially random scission models. In comparison with the GPC/LALLS data, the middle portion of each single- or multiple-stranded chain was sheared randomly, whereas the adjacent end portions of the chain resisted sonic scission. The Mw value of each intact end portion was 1.0 × 10⁵ for (U)n, 1.5 × 10⁵ for DNA, and 1.7 × 10⁵ for (A)n·2(I)n, corresponding to the lowest possible Mw for the sonicated but unfractionated nucleic acid samples under the present conditions.

Elimination kinetics of ethanol without (control group) and with pyrazole [alcohol dehydrogenase (ADH) inhibitor] pretreatment was studied with changing the i.v. dose amount to evaluate the respective role of ADH and non-ADH pathways in a rabbit. The moment analysis of the blood ethanol concentration-time curves showed that the normalized area under the blood ethanol concentration-time curve and the first moment increase with increasing dose amount in the control and pyrazole-pretreated groups. These increases suggested the capacity-limited elimination of ethanol through pyrazole-insensitive non-ADH pathways as well as through ADH pathway as pyrazole would fully block the oxidation of ethanol through ADH pathway. The simultaneous multiline fitting using time curves after five different doses also was attempted to determine the pharmacokinetic model by the application of minimum Akaike's information criterion estimation. Akaike's information criterion, consequently, showed the minimum for a two-compartment model with parallel first-order and Michaelis-Menten elimination kinetics. The computer analysis using this model yielded almost the same values of the volume of distribution and of the first-order elimination rate constant between both groups. The distribution of ethanol and the first-order elimination process were not influenced by pyrazole treatment. Km (0.57 mg/ml) of the pyrazole-pretreated group was higher than Km (0.03 mg/ml) of the control group. These results suggest that ADH pathway is readily saturated and non-ADH pathways are unsaturated over the wide range of concentration. The first-order process as well as non-ADH pathways are concluded to occupy the considerable part in the ethanol elimination at higher blood concentration.

Summary Recently, it has been suggested that antidepressant drugs exert their pharmacological action through functional changes in the adrenergic-receptor coupled adenylate cyclase system. In the present research, we examined the direct effects of antidepressants on adenylate cyclase (A-cyclase) activity by in vitro incubation of cell membranes from the cerebral cortex of rats with these drugs. All antidepressants examined, such as imipramine, clomipramine, amitriptyline, desipramine, mianserin and zimelidine inhibited A-cyclase in a dose dependent manner. Antidepressants did not exert any influence on Mn2+-induced elevation of A-cyclase, but significantly suppressed F--stimulated A-cyclase activity. GTP-induced elevation of A-cyclase was completely inhibited by prior incubation with antidepressants. Our conclusion, therefore, is that antidepressants may reduce A-cyclase activity not by inhibiting the function of the catalytic unit of A-cyclase, but by supressing the N-protein function.

Abstract.: ATP-sensitive potassium channels were found in frog ventricular myocytes using the inside-out patch-clamp technique. The channel was selectively permeable to K+. Single-channel conductance was 32.6 pS at 3.0 mm of [K+] o and 132 mm [K+] i and 77.3 pS at 114 mm [K+] o and 132 mm [K+] i . ATP did not affect single-channel conductance. The open probability of the channel was decreased by intracellular application of ATP in both the presence and absence of 2 mm MgCl2. The coexistence of Mg2+ with ATP shifts the dose-response curve for the open probability of ATP-sensitive K+ channel against ATP rightward. The shift of the curve indicates that Mg-ATP is less effective than free ATP in inhibiting the channel. An open-time histogram was fitted by a single exponential function with a time constant of 1.63 � 0.17 msec (n= 5) in an ATP-free medium. Mean open time (1.57 � 0.10 msec; n= 5) was not altered but the inter-burst time (closed time between bursts) lengthened in 10 μm ATP.

Previously we isolated a trypsin-like enzyme designated human airway trypsin-like protease from the sputum of patients with chronic airway diseases. This paper describes the cDNA cloning, characterization of the primary protein structure deduced from the cDNA, and gene expression of this enzyme in various human tissues. We obtained an entire 1517-base pair sequence of cDNA with an open reading frame encoding a polypeptide with 418-amino acid residues. The polypeptide consisted of a 232-residue catalytic region and a 186-residue noncatalytic region with a hydrophobic putative transmembrane domain near the NH2 terminus. The polypeptide was suggested to be a type II integral membrane protein in which the COOH-terminal catalytic region is extracellular. Therefore, this protein is thought to be synthesized as a membrane-bound precursor and to mature to a soluble and active protease by limited proteolysis. It showed 29-38% identity in the sequence of the catalytic region with human hepsin, enteropeptidase, acrosin, and mast cell tryptase. The noncatalytic region had little similarity to other known proteins. In Northern blot analysis a transcript of 1.9 kilobases was detectable most prominently in the trachea among 17 human tissues examined.

Interleukin-4 (IL-4) and IL-13 are functionally similar cytokines. The functional IL-4 receptor (IL-4R) consists of the IL-4R alpha chain (IL-4R alpha) and the IL-2R gamma chain (gamma c), which is shared by the IL-2, IL-7, IL-9, and IL-15 receptors. The functional IL-13R is thought to involve the IL-4R alpha but not gamma c. In this study, we have analyzed activation of members of the Janus tyrosine kinase (Jak) family and signal transducers and activators of transcription (STAT) 6 induced by IL-4 and IL-13 in Epstein-Barr virus-transformed B cells derived from two patients of X-linked severe combined immunodeficiency, who have mutations of the gamma c gene in the extracellular and intracellular domains. In these B cells, IL-4 failed to induce tyrosine phosphorylation of Jak3 and activation of STAT6, or activation of these molecules was significantly decreased compared with Epstein-Barr virus-transformed normal B cells. In contrast, IL-13 activated STAT6 in these cells as well as normal B cells. However, Jak3 was not activated by IL-13, even in normal B cells. These results clearly indicated that gamma c is essential for activation of Jak3 and STAT6 in the signal transduction pathway of IL-4 in human B cells and that IL-13 does not utilize gamma c but activates STAT6 through an alternative pathway, which is not impaired in B cells of X-linked severe combined immunodeficiency patients.

Reduced electric linear dichroism (ELD), Δε/ε, of the title duplexes in ionic solutions was measured at 7 °C in the 1.5−24 kV/cm field strength and 300−190 nm wavelength regions. The rodlike (rA)n·(rU)n and (dA)n·(dT)n samples, whose counterion was Mg²⁺ in most cases, were prepared by sonication and subsequent fractionation. The weight-average molecular weight and molecular weight distribution of each fraction, determined by the GPC/LALLS method, were taken into account in the analysis of the field strength dependence of Δε/ε values. These values were fitted to theoretical orientation functions to evaluate the saturated reduced dichroism, (Δε/ε)s, at absorption peaks. The wavelength dependence of (Δε/ε)s, the ELD spectrum, was undulatory in the 300−190 nm region. The isotropic absorption and second-derivative spectra of each duplex were decomposed into eight component bands, which were assigned to constituent bases. The analysis of ELD spectrum revealed that the individual bases are both tilted and rolled in the rA·rU and dA·dT base pair and that the planes are bent. From transient dichroism signals, the weight-average rotational relaxation time, τw, was obtained, from which the axial translation per base pair, h, was evaluated. The limiting h values were found to be ca. 2.6 Å for (rA)n·(rU)n and ca. 3.0 Å for (dA)n·(dT)n. Thus, both duplexes were concluded to belong to the A-form family.

The sonicated and fractionated poly(rG)·poly(rC) (I) and poly(dG)·poly(dC) (II) samples mostly with Na⁺ counterions were studied, on a comparative basis, to determine the spatial arrangement of the constituent G and C bases with respect to the double-stranded helical axis in ionic aqueous solutions. The reduced electric linear dichroism, Δε/ε, was measured at 7 °C in 1.5−24 kV/cm field strength and 300−190 nm wavelength regions. By analyzing the field strength dependence of observed Δε/ε values with theoretical orientation functions, the saturated reduced dichroism, (Δε/ε)s, at 260 nm was evaluated to be −0.96 ± 0.02 for I and −0.93 ± 0.01 for II. The electric linear dichroism (ELD) spectra of these duplexes are very close to each other, being undulatory, but not constant, in the whole wavelength region. The (Δε/ε)s values are never as high as −1.5, indicating that the optical transition moments of the nucleic acid bases responsible for the UV absorption bands are not normal to the helix axis. By analyzing the ELD spectra with a newly developed technique, the inclination angle α, the roll angle θR, and the tilt angle θT were evaluated for the individual bases. The most likely values are 24°, 1°, and 24° for rG; 26°, 1°, and 26° for rC in the rG·rC base pair; 26°, 2°, and 26° for dG; 29°, 3°, and 29° for dC in the dG·dC pair. Thus, the base pairs are only slightly bent and propeller twisted, being nearly coplanar. Both duplexes were concluded to exist in the same conformation and to belong to the same A-form family in solutions in spite of the different sugar structure, contrary to X-ray results in the solid state.

In order to address the question of whether protein kinase C (PKC) is involved in the growth regulation of human glioma cells, we introduced PKC cDNA expression vectors into a human glioma cell line, U-251 MG, and established sets of stable cell clones that overexpress PKCγ or δ. Cell clones obtained by the transfection of PKCγ cDNA express 3.6 to 5 times more PKC activity than parental cells that express predominantly endogenous PKCα. These PKCγ overexpressing cell clones show an increased rate of growth in monolayer culture, increased colony-forming efficiency on soft agarose, and increased DNA synthesis in response to epidermal growth factor and basic fibroblast growth factor. Cell clones obtained by transfection with PKCδ cDNA express 2 to 10 times more PKC than that produced endogenously. PKCδ overexpressing cells show a decreased rate of growth and decreased colony-forming efficiency. However, these PKCδ cell clones show no significant changes in responsiveness to the growth factors described above. These results clearly indicate that different PKC family members have distinct regulatory functions in cell growth and that PKC is involved in several aspects of the growth regulation of human glioma cells.Copyright 1994, 1999 Academic Press, Inc.

The frequency of the HLA-DR4-DQ4 haplotype (DRB1(*)0405-DQA1(*)0302-DQB1(*)0401) is significantly increased in Japanese patients with rheumatoid arthritis (RA) and DRB1(*)0405-binding peptide motifs were identified in our previous studies. To clarify the DQ4-binding peptide motifs, the primary structure of DQ4-binding peptides was determined by affinity-based selection of a phage random peptide library. Analog peptides of a high-affinity DQ4 binder revealed that two major anchors (VxxxxxxxR; where x is any amino acid) play an essential role in binding to DQ4. The affinity of synthetic VAAAAAAAR-based analog peptides showed that substituting V to W, G, L, I, M, P, F, Y or A and R to H, M, L, I or V allows binding. The involvement of the ninth residue of the peptides, especially Arg, was critical for high-affinity binding. In comparison with other class II-binding peptide motifs reported to date, peptide motifs for DQ4 were unique, in that Gly and Pro are allowed as low-affinity N-terminal anchors. Interestingly, 94 putative DQ4-binding motifs were detected in the human type II collagen molecule, since it is composed of (Gly-X1-X2)n and is rich in R and P at positions X2. However, no significant differences were observed between the affinities of the collagen-derived peptides with DR or DQ molecules of RA-susceptible DR4-DQ4 and with those of non-susceptible DR4-DQ8 (DRB1(*)0406-DQA1(*)0301-DQB1(*)0302) haplotypes, indicating that the susceptibility to RA is not a simple immune response gene phenomenon specific to collagen. The immunogenetic implications of the unique peptide motifs for DQ are discussed.