Biomedical subjects

S Ono

Publications and source records attributed to S Ono.

At least 19 recordsLinked to original sources

PubMed1997

Intracytoplasmic inclusion bodies of the substantia nigra in myotonic dystrophy. Immunohistochemical observations.

We recently reported a significantly higher incidence of intracytoplasmic inclusion bodies (IIBs) of the substantia nigra in patients with myotonic dystrophy (MyD) than in age-matched controls. The changes are, per se, not specific, since a small percentage of disease and normal controls also showed similar inclusions. To elucidate the pathological significance of the inclusion in MyD, we studied immunohistochemical characteristics of IIBs of the substantia nigra in eight patients with MyD. Many IIBs showed moderately intense immunoreactivity for ubiquitin, microtubule-associated protein (MAP) 1 and MAP 2. However, the IIBs did not react with any of the following: anti-neurofilament protein antibodies (Abs) (68, 160 and 200 kDa), anti-neuron-specific enolase antibody (Ab), anti-tau Ab, anti-tubulin Abs (alpha and beta), anti-paired helical filament Ab, anti-actin Ab, anti-phosphorylated epitope of neurofilaments Ab, anti-synaptophysin Ab, anti-myelin basic protein Ab, anti-actin Ab and anti-glial fibrillary acidic protein Ab. Our results suggest that IIBs of the substantia nigra in MyD are related to an alteration of neuronal cytoskeleton metabolism affecting microtubular proteins in conjunction with activation of ubiquitin proteolytic systems.

Aged↗

PubMed1997

Effects of R(-)-1-(benzo[b]thiophen-5-yl)-2-[2-N,N-diethylamino)ethoxy]ethan ol hydrochloride (T-588), a novel cognitive enhancer, on noradrenaline release in rat cerebral cortical slices.

We investigated the effects of R(-)-1-(benzo[b]thiophen-5-yl)-2-[2-(N,N-diethylamino)ethoxy]ethan ol hydrochloride (T-588), a novel cognitive enhancer, on noradrenaline (NA) release from rat cerebral cortical slices in vitro. Addition of T-588 in an assay mixture stimulated [3H]NA release from prelabeled slices in the presence or absence of extracellular CaCl2, and in the presence of the Ca2+/calmodulin antagonists N-(6-aminohexyl)-5-chloro-1-naphthalenesulfonamide and trifluoperazine. T-588 stimulated NA release with a time lag of about 1 min, and the high level of release was maintained for at least 10 min, whereas maximal KCl-evoked NA release was observed within 1 min after the addition of KCl, and the effect declined subsequently. The effect of T-588 was reversible (pretreatment with T-588 showed no effect on NA release after two washes by centrifugation). We also compared the effects of T-588 and N-ethylmaleimide (NEM), a sulfhydryl alkylating agent known to stimulate neurotransmitter release in several types of cells. The addition of NEM stimulated NA release irreversibly from the slices in a Ca2+-independent manner, and the effect of NEM, but not that of T-588, was inhibited by the simultaneous addition of dithiothreitol, a sulfhydryl group reducing agent. The addition of T-588, which stimulated NA release by itself, inhibited the NA release by 0.6 mM NEM, although the effect of T-588 was additive in the presence of 0.2 mM NEM. These findings suggest that T-588 stimulates NA release from rat cerebral cortical slices in a Ca2+- and calmodulin-independent manner, possibly via an NEM-sensitive factor(s), although the mechanism of the effects of T-588 seems to be different from that of NEM.

Animals↗

PubMed1997

Guamanian neurodegenerative disease: ultrastructural studies of skin.

It is evident that Guamanian amyotrophic lateral sclerosis (ALS) and parkinsonism-dementia complex (PDC) are clinical variants of a single disease entity and that Guamanian ALS is clinically indistinguishable from sporadic ALS. We studied by electron microscopy the skin tissues from 11 patients with Guamanian neurodegenerative disease (PDC and ALS), 11 Chamorro control subjects, 10 Japanese patients with sporadic ALS and 11 Japanese control patients. Among patients with sporadic ALS, there was an inverse relationship of collagen fiber diameter and the duration of disease and a marked increase of amorphous material in the ground substance. These findings were not observed in the Guamanian patients or controls. Therefore, the skin studies reinforce the view of a different disease mechanism in Guamanian ALS and PDC compared to sporadic ALS.

Adult↗

PubMed1997

A shift from negative to positive selection of autoreactive T cells by the reduced level of TCR signal in TCR-transgenic CD3 zeta-deficient mice.

T cell selection is thought to be determined through the interaction between TCR and Ag/MHC. However, the contribution of the level of TCR signal to thymic selection remains unclear. To address this issue, we analyzed T cell selection of male Ag (HY)-specific TCR transgenic (HYTg) mice crossed with CD3 zeta-deficient (zeta KO) mice (HYTg/zeta KO), which have impaired signaling through TCR. In male HYTg/zeta KO mice, the number of thymocytes was comparable to that in normal mice, and almost all the peripheral T cells were HY specific, although these positively selected cells were anergic to male Ag. From these observations, the decrease in TCR signaling by CD3 zeta deficiency resulted in both the avoidance of negative selection and the acquisition of positive selection of autoreactive T cells in male HYTg/zeta KO mice. There was a shift of T cell selection from positive to no selection of HY-specific T cells in female HYTg/zeta KO mice also. Collectively, these findings suggest that the level of TCR signal directly regulates T cell selection; furthermore, the findings have integrated the models of T cell selection into a concept based on the quantity of TCR signal.

Animals↗

PubMed1997

Identification of an actin binding region and a protein kinase C phosphorylation site on human fascin.

Fascin is a 55-58-kDa actin-bundling protein, the actin binding of which is regulated by phosphorylation (Yamakita, Y., Ono, S., Matsumura, F., and Yamashiro, S. (1996) J. Biol. Chem. 271, 12632-12638). To understand the mechanism of fascin-actin interactions, we dissected the actin binding region and its regulatory site by phosphorylation of human fascin. First, we found that the C-terminal half constitutes an actin binding domain. Partial digestion of human recombinant fascin with trypsin yielded the C-terminal fragment with molecular masses of 32, 30, and 27 kDa. The 32- and 27-kDa fragments purified as a mixture formed a dimer and bound to F-actin at a saturation ratio of 1 dimer:11 actin molecules with an affinity of 1.4 x 10(6) M-1. Second, we identified the phosphorylation site of fascin as Ser-39 by sequencing a tryptic phosphopeptide purified by chelating column chromatography followed by C-18 reverse phase high performance liquid chromatography. Peptide map analyses revealed that the purified peptide represented the major phosphorylation site of in vivo as well as in vitro phosphorylated fascin. The mutation replacing Ser-39 with Ala eliminated the phosphorylation-dependent regulation of actin binding of fascin, indicating that phosphorylation at this site regulates the actin binding ability of fascin.

Actins↗

PubMed1997

B cells regulate CD40 ligand-induced IL-12 production in antigen-presenting cells (APC) during T cell/APC interactions.

Although stimulation of freshly isolated murine spleen cells with anti-CD3 mAb or Con A failed to generate IL-12 production, the same cell preparations depleted of B cells produced IL-12. Addition of normal B cells inhibited IL-12 production in a cell number-dependent manner. IL-12 production was dependent on the presence of CD4+, but not of CD8+, T cells, and inhibited by addition of anti-CD40 ligand (CD40L) mAb. Anti-CD3 or Con A stimulation induced CD40L expression only on CD4+ T cells, which was inhibited in the presence of B cells. IL-12 production was also induced by interactions between CD40L-transfected Chinese hamster ovary cells and splenocytes depleted of T and B cells, but not of APC, indicating CD40L-induced IL-12 production by APC. The involvement of CD40 molecules was examined by comparing the ability of cells from CD40-deficient (CD40 -/-) and wild-type mice (CD40 +/+) to produce IL-12. Spleen cells from CD40 -/- and CD40 +/+ mice produced comparable amounts of IL-12 in response to bacterial stimuli. However, the B cell-depleted fraction from CD40 -/- mice failed to produce IL-12 when stimulated with anti-CD3 or Con A or when cocultured with CD40L-expressing Chinese hamster ovary cells. These results indicate that CD40L expressed on activated T cells induces APC to produce IL-12 through CD40/CD40L interaction, but this pathway is competitively inhibited by CD40+ B cells incapable of producing IL-12 upon stimulation with CD40L. Thus, this might represent a novel mechanism underlying the regulation of cell-mediated and humoral immunity.

Animals↗

PubMed1997

Regulation of T cell-dependent and -independent IL-12 production by the three Th2-type cytokines IL-10, IL-6, and IL-4.

The production of IL-12 by macrophages/dendritic cells (Mphi/DC) is mediated either by a T cell-dependent pathway that is induced primarily by the interaction of CD40 ligand (CD40L) on activated T cells with CD40 on IL-12-producing cells or by a T cell-independent pathway that is induced by bacteria or bacterial products and enhanced by interferon-gamma (IFN-gamma). In this study we investigated the ability of the Th2-type cytokines interleukin (IL)-10, IL-6, and IL-4 to modulate IL-12 production in Mphi/DC induced through the two pathways. IL-12 production was induced in Mphi/DC from normal mice by stimulation with the combination of IFN-gamma plus lipopolysaccharide (LPS) or Staphylococcus aureus Cowan I (a model for the T cell-independent pathway) or by co-culture with Chinese hamster ovary (CHO) cells transfected with the CD40L (a model for the T cell-dependent pathway). The effects of three Th2-type cytokines on IL-12 production by Mphi/DC through the two pathways were examined. IL-10 inhibited IL-12 production induced through both pathways, although the inhibitory effect was more potent on the (IFN-gamma + LPS)-induced pathway. IL-6 inhibited only (LPS + IFN-gamma)-induced IL-12 production. The effect of IL-4 was particularly noteworthy: this cytokine inhibited (LPS + IFN-gamma)-induced IL-12 production, whereas it potentiated the production of IL-12 induced by CD40L. Regulation of IL-12 protein production by IL-10 and IL-4 was found to correspond to the levels of mRNA accumulation for the p40 and p35 IL-12 genes, whereas the presence of IL-6 during stimulation decreased IL-12 protein production without affecting steady-state mRNA levels. These results indicate that IL-12 production in Mphi/DC induced through a T cell-dependent or -independent pathway is positively or negatively regulated by particular cytokines at various control levels.

Animals↗

PubMed1997

A method for the quantification of benzodiazepine receptors by using 123I-iomazenil and SPECT with one scan and one blood sampling.

Iodine-123-iomazenil (Iomazenil) is a ligand of central type benzodiazepine receptors for single photon emission computed tomography (SPECT). Previously we reported a simple, table look-up method for quantification of its binding potential (BP) by using two SPECT scans and calibrated standard input function with one blood sampling. This method is based on a two-compartment model (K1: influx rate constant; k2: efflux rate constant; Vd (= K1/k2): the total distribution volume corresponding BP), and requires two SPECT scans for calculating both K1 and Vd values. If the K1 value in the two-compartment model can be assumed to be constant, the radioactivity of one SPECT scan at 180 min after injection can be considered to tabulate as a function of Vd for a given K1 value and a given input function, and a table look-up procedure provides the corresponding Vd value. The purpose of this study was to develop a simple, autoradiographic method for quantification of BP by using one SPECT scan and calibrated standard input function with one blood sampling. SPECT studies were performed on 14 patients. A dynamic SPECT scan was initiated following an intravenous bolus injection of Iomazenil. A static SPECT scan was performed at 180 min after the injection. Frequent blood sampling from the brachial artery was performed on all subjects to determine the arterial input function. Simulation studies revealed that errors in calculated Vd values were around +/-10-15% for varied K1 values. A good correlation was observed between total distribution volume values calculated by three-compartment model analysis and those calculated by the present method (r = 0.90), supporting the validity of this method. The present method is simple and applicable for clinical use, and will be able to provide images of BP.

Adult↗

PubMed1997

The influence of coronary collateral flow on the assessment of myocardial perfusion by videodensitometry.

OBJECTIVES: Coronary collateral flow often mitigates the effects of coronary artery obstruction and has a significant impact on the prognosis of patients with coronary artery disease. In the presence of variable degrees of coronary collateral flow, digital radiographic assessment of myocardial blood flow has not been quantitatively validated. METHODS: A distal coronary arterial collateral path was created into the left anterior descending coronary artery (LAD) bed in 8 anesthetized pigs. Both LAD and collateral paths were pump-perfused and corresponding flows measured. A number of commonly used digital indices and parametric images of myocardial perfusion were then extracted from the sequence of images filmed before and during the injection of contrast. Data were acquired at 5 levels of total flow (LAD flow + collateral flow): 100, 85, 70, 55 and 40% of maximally vasodilated, baseline flow. At each level of total flow, data were acquired at 4 levels of collateral flow ratios (collateral flow/total flow): 0, 10, 25 and 50%. RESULTS: Regional percent segment shortening, reflecting myocardial blood flow, decreased as total flow fell, and remained unaltered when coronary collateral ratio alone was altered without change in total flow. On the other hand, linear regression between total flow and digital indices at 10, 25 and 50% coronary collateral flow ratios, compared with 0%, showed a successive and significant downward displacement, documenting an underestimation of flow by all digital indices in the presence of collateral flow. CONCLUSIONS: In the absence of a collateral pathway and during maximal coronary vasodilation with adenosine, digital radiographic indices of myocardial perfusion, based upon indicator dilution theory, show a relatively good correlation with regional transmural myocardial blood flow. However, due to underestimation of total transmural blood flow, these indices have limited utility when myocardial perfusion is provided in part by a collateral pathway. The effect is probably related to an alteration in the regional vascular volume into which iodinated contrast is injected.

Adenosine↗

PubMed1997

A novel thromboxane synthetase inhibitor, DP-1904, inhibits human blood eosinophil degranulation.

Eosinophils have been recognized to be associated with various immune responses and disease processes including bronchial asthma. Eosinophils release a number of cytotoxic and neurotoxic mediators. However, the factors regulating such release and the underlying mechanisms are unclear. In this study, we investigated the effect of a selective and potent thromboxane synthase inhibitor, DP-1904, on the release of eosinophil cationic protein (ECP) in platelet activating factor (PAF) and IgG-stimulated human blood eosinophils. PAF (1 microM) and IgG both released ECP which constituted about 25-30% of the total ECP content. The control protein, ovalbumin, did not release any ECP over the basal values. DP-1904 in two different concentrations, 10 microM and 100 microM, significantly attenuated the release of ECP in response to PAF or IgG. The mean percent inhibition by 10 microM DP-1904 was 49 +/- 10 and 31 +/- 2 against PAF and IgG-induced ECP release, respectively. However, at 100 microM DP-1904 the percent inhibition was 76 +/- 14 and 67 +/- 2, respectively. These data suggest that TXA2 is an important mediator in the regulation of eosinophil degranulation, and DP-1904 thus might prove beneficial in the treatment of bronchial asthma.

Asthma↗

PubMed1997

Production of a T-cell clone which reacts with membrane proteins of Acholeplasma laidlawii.

The role of cellular immunity in mycoplasma infection is not completely understood. In this study, we established mycoplasma-specific T-cell clones to evaluate cellular immunity in mycoplasma infection. We developed a T-cell clone (G-10) which was stimulated with Acholeplasma laidlawii. The T-cell clone G-10, CD4+ and T-cell receptor (TCR) alpha beta- recognized the 42- and 65-kilodalton (kDa) membrane proteins of A. laidlawii and responded to A. hippikon. Hence, the application of mycoplasma-specific T cells such as G-10 in animal models may allow the assessment of cellular immune response to mycoplasma infection.

Acholeplasma laidlawii↗

PubMed1997

Trinucleotide repeat polymorphism within exon 5 of the MICA gene (MHC class I chain-related gene A): allele frequency data in the nine population groups Japanese, Northern Han, Hui, Uygur, Kazakhstan, Iranian, Saudi Arabian, Greek and Italian.

We recently identified a trinucleotide repeat polymorphism, (GCT)n, within the transmembrane (TM) segment of the human MHC class I MICA gene (MHC class I chain-related gene A). Five distinct alleles (A4, A5, A5.1, A6, A9) corresponding to 4, 5, 5 with one nucleotide insertion, 6 and 9 repetitions, respectively, have been detected in various HLA-homozygous B cell lines. Here we present allele frequencies for this trimeric short tandem repeat (STR) in 604 unrelated individuals collected from nine human populations (Japanese, Northern Han, Hui, Uygur, Kazakhstan, Iranian, Saudi Arabian, Greek and Italian) determined using the polymerase chain reaction (PCR) combined with fluorescent-based automated fragment detection technology. All alleles were present in each population, but allelic distributions varied from one population to another. No new alleles (such as A7 or A8) were identified. The evolutionary and structural significance of these data as well as the potential application to forensic medicine is discussed.

Alleles↗

PubMed1997

[The binding activity of diglucosyl diacylglyceride derived from membranes of Acholeplasma laidlawii PG8 to lymphoid cells].

A chemical component has been purified from Acholeplasma laidlawii which binds to tissue culture cells, MOLT-4, Hut-78, but not MT-4 and Jurkat. The glycolipid in the membranes of A. laidlawii was extracted by Bligh-Dyer method. Further purification of chloroform phase of Bligh-Dyer method was performed by silicagel column chromatography and thin layer chromatography. Finally, the active component was assigned to be diglucosyl diacylglyceride by using nuclear magnetic resonance (1H, 13C). Furthermore, diglucosyl diacylglyceride(s) with C14 and C18 were synthesized, by the method of Boom. Both native and synthesized diacylglycerides bind to MOLT-4 and Hut-78 cells. The binding activity of these substances to cells was inhibited by preincubation of diglucosyl diacylglycerides on the cover glass with clathrin. These results suggest that the binding site of diglucosyl diacylglycerides on cells was clathrin. It is necessary to clarify the biological activities of diglucosyl diacylglycerides in viral infections and transmission of lipoprotein and the how mechanism of envelopment of the virus into the cell.

Acholeplasma laidlawii↗

PubMed1997

Vasoactive intestinal peptide causes nitric oxide-dependent pulmonary vasodilation in isolated rat lung.

Vasoactive intestinal peptide (VIP) is one of the chief neurotransmitters of nonadrenergic noncholinergic nerve fibers. In this study, we investigated the effect of VIP on the pulmonary circulation in isolated perfused rat lungs. Baseline pressures of the pulmonary artery for the isolated rat lungs were not affected by 3 x 10(-8) M VIP. VIP caused dose-dependent pulmonary vasodilation when the pulmonary vascular bed was constricted with 20 mM KCl. This vasodilative effect of VIP was inhibited by 1 x 10(-6) M L-n omega-nitro-arginine, an endothelium-derived relaxing factor (nitric oxide) inhibitor, and was restored by the addition of 10(-4) M L-arginine, a substrate of nitric oxide. VIP also caused suppression of the ANG II pressor response, and this VIP-induced suppressive effect was reduced when L-N omega-nitro-arginine or 3 x 10(-6) M meclofenamate was added to the perfusate. These results indicate that VIP causes pulmonary vasodilation in isolated rat lung and suggest the possible involvement of NO and/or cyclooxygenase metabolites in VIP-induced pulmonary vasodilation.

Angiotensin II↗

PubMed1997

Three-dimensional analysis of vasospastic major cerebral arteries in rats with the corrosion cast technique.

BACKGROUND AND PURPOSE: Although mice, rats, and other small animals are commonly used for molecular biology research, their use in the evaluation of cerebral vasospasm after subarachnoid hemorrhage is somewhat problematic because of the correspondingly small size of their cerebral vessels. We have already reported that the corrosion cast technique was useful for evaluating newly formed cerebral vessels in neural grafts in these small animals. In the present study we applied the corrosion cast technique to the evaluation of hemolysate-induced cerebral vasospasm in rats and performed three-dimensional analysis for comparison. The casting was done 10 minutes after the hemolysate injection, so that only acute "vasospasm" was assessed. METHODS: After withdrawal of 0.1 mL cerebrospinal fluid, 0.2 mL hemolysate (n = 9) or saline (n = 10) was injected into the cisterna magna of male Sprague-Dawley rats weighing between 300 and 350 g. Ten minutes later, perfusion of a semipolymerized casting medium was performed at an injection pressure of 100 to 120 mm Hg. The brains were immersed and corroded in 10% NaOH solution. After these procedures, the basilar artery as well as peripheral vessels was analyzed morphologically with scanning electron microscopy. Conventional histological analysis with the use of paraffin-embedded section with hematoxylin-eosin staining was also performed, and the results were compared with those for the corrosion cast methods. RESULTS: In the saline-injected group, SEM showed that the inner surface of the basilar artery was smooth and the form of the endothelial cell was printed on the surface of the cast. In the hemolysate-injected group, the basilar artery showed an apparent vasospasm over its entire length, and corrugation was observed on the inner surface of the basilar artery in a three-dimensional fashion. Higher magnification revealed that the nuclei of the endothelial cells were distorted. Local narrowing of the basilar artery and vasospasm in the arteries of the anterior circulation and in peripheral arteries were also observed. Measurement of the inner diameter of the basilar artery showed 37.8% contraction in the hemolysate-injected group compared with the saline-injected group by the corrosion cast method. This degree of vasospasm was similar to that observed by the conventional histological method. CONCLUSIONS: In this report we show that detailed three-dimensional observation in the rat can be performed qualitatively and quantitatively with the corrosion cast technique. We conclude that this method derives an accurate measurement of the diameter of rat major cerebral arteries and is more reliable for analyzing vasospasm in rats than angiography and other conventional procedures.

Animals↗

PubMed1997

Low molecular-weight G-actin binding proteins involved in the regulation of actin assembly during myofibrillogenesis.

We previously demonstrated that small G-actin binding proteins, cofilin, ADF and profilin, are involved in the actin dynamics during myofibrillogenesis (OBINATA, T. (1993). Int. Rev. Cytol., 143: 153-189.). To better understand how they are responsible for the regulation of actin assembly, the amounts of the actin-binding proteins were quantified by means of quantitative immunoblotting and compared with that of G-actin pool. The sum of the amounts of cofilin, ADF and profilin was insufficient at early developmental stages but sufficient at later stages to account for the pool of G-actin in muscle cells. We detected expression of thymosin beta 4 at a considerable level in young embryonic but not in adult skeletal muscles. We, therefore, conclude that the G-actin pool in young embryonic skeletal muscle is mainly due to cofilin, ADF, profilin and thymosin beta 4. Switching from a non-muscle-type (NM-) cofilin to a muscle-type (M-) cofilin was observed during muscle development of mammals. In order to clarify cofilin-dependent regulation of actin assembly in muscle cells, cofilin tagged with fluorescence dyes was introduced into C2 myoblasts by a micro injection method. The exogeneous cofilin, but not ADF, caused quick disassembly of actin filaments and accumulated in furrow region of dividing cells. The analogs of the unphosphorylated form (A3-cofilin) and the phosphorylated form (D3-cofilin) were prepared by converting Ser3, a regulatory phosphorylation site, to Ala or Asp. When A3-cofilin and D3-cofilin were injected into living cells, the former was concentrated at the membrane ruffles and cleavage furrow, while the latter showed only diffuse distribution in the cytoplasm. These results suggest that the subcellular distribution of cofilin as well as its interaction with actin in vivo is regulated by its phosphorylation and dephosphorylation.

Actin Depolymerizing Factors↗

PubMed1997

Dysphasia accompanied by periodic lateralized epileptiform discharges.

We encountered a 67-year-old man who presented with repetitious dysphasia accompanied by periodic lateralized epileptiform discharges (PLEDs) on the electroencephalogram. A good correlation was established between the dysphasia and the PLEDs. A persistent partial seizure accompanied by PLEDs originating in the left hemisphere presented with dysphasia clinically. None of the previously reported patients with epileptic dysphasia had accompanying PLEDs. The administration of carbamazepine was successful to terminate the seizure, however valproate was not. This case indicates that PLEDs may produce significant, however reversible, functional damage, and may advance our understanding of the pathophysiology of epileptic dysphasia.

Aged↗

PubMed1997

[A case of systemic origin of an aberrant artery to the basal segment of the lung].

We report on a rare case of systemic origin of an aberrant artery to the basal segment of the lung (Pryce I type intralobar pulmonary sequestration) that caused occasional bloody sputum. The patient was admitted to our hospital after an abnormal image was discovered in Chest X-ray film. The chest MRI showed an abnormal vessel originating from the descending aorta. The aortagram showed an abnormal artery originating from the descending aorta and entering the left lower lobe, and the left pulmonary angiogram revealed a poorly blood supply to the left basal segments. The preoperative diagnosis of systemic origin of an aberrant artery to the basal segment of the lung was given. The patient was subjected to surgical treatment. During surgery, it was found that the abnormal artery, 12 mm in diameter, which was connected from the descending aorta to the left basal segments. The abnormal artery was dissected, and the left basal segments was removed. The postoperative course was uneventful.

Aorta, Thoracic↗