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K Yamaguchi

Publications and source records attributed to K Yamaguchi.

At least 289 records · Page 16Linked to original sources
PubMed2000

Carcinoma of the ampulla of Vater associated with or without adenoma: a clinicopathologic analysis of 198 cases with reference to p53 and Ki-67 immunohistochemical expressions.

Adenomatous areas are found frequently within or in the vicinity of carcinoma of the ampulla of Vater. This makes definite diagnosis difficult in the preoperative examination. The adenoma-carcinoma development hypothesis is generally accepted for colorectal tumors. Recently, a genetic alteration model during colorectal tumor development has attracted much attention, leading to various studies. We studied clinicopathologic features, prognostic factors, and the alteration of the p53 tumor suppressor gene using p53 immunohistochemical staining in pure adenomas, pure carcinomas, and carcinomas with adenomatous areas. A proliferative activity of the tumors using Ki-67 was also evaluated. Nine cases of pure adenoma and 198 cases of carcinoma of the ampulla of Vater were selected for this study. Among the 198 cases of thecarcinoma, 83 cases (42%) had adenomatous areas. Positivity of p53 immunohistochemical staining was 0% in pure adenomas, 36% in the adenomatous areas of carcinomas with adenomatous areas and 62% in the carcinomatous areas of carcinomas with adenomatous areas, and 56% in pure carcinoma. Accumulation of p53 protein and the Ki-67 labeling index revealed no significant difference in prognosis. The clinicopathological factors examined were as follows: degree of invasion of the surrounding tissue, such as duodenal wall; pancreatic parenchyma; the presence or absence of lymphatic permeation; venous invasion; perineural invasion; the presence of regional lymph node metastasis; and TNM stage. Each of the clinicopathological factors showed a significant difference. Multivariate analysis revealed strong predictors for a worse prognosis: presence of lymphatic permeation, invasion of the pancreas, and perineural invasion. In conclusion, our results are consistent with the adenoma--carcinoma development hypothesis. It would seem that the molecular events leading to p53 accumulation in neoplasms of the ampulla of Vater occur relatively late during the oncogenetic process. Moreover, we think it may be useful to refer to the p53 overexpression in the diagnosis of ampullary tumors.

Adenoma↗
PubMed2000

Involvement of interleukin-1 in the inflammatory actions of aminobisphosphonates in mice.

Aminobisphosphonates (aminoBPs) are potent inhibitors of bone resorption. However, they cause undesirable inflammatory reactions, including fever, in humans. Intraperitoneal injection of aminoBPs into mice also induces inflammatory reactions, including a prolonged elevation of the activity of the histamine-forming enzyme, histidine decarboxylase (HDC). Because interleukin-1 (IL-1) is a typical pyrogen and a strong inducer of HDC, we examined whether aminoBPs induce inflammatory reactions in mice deficient in genes for both IL-1alpha and IL-1beta (IL-1-KO mice). In control mice, aminoBPs induced an elevation of HDC activity and other inflammatory reactions (enlargement of the spleen, atrophy of the thymus, exudate in the thorax and increase in granulocytic cells in the peritoneal cavity). These responses were all weak or undetectable in IL-1-KO mice. We have previously shown that lipopolysaccharides (LPSs) from Escherichia coli and Prevotella intermedia (a prevalent gram-negative bacterium both in periodontitis and endodontal infections) are capable of inducing HDC activity in various tissues in mice. In control mice treated with an aminoBP, the LPS-induced elevations of serum IL-1 (alpha and beta) and tissue HDC activity were both markedly augmented. However, such an augmentation of HDC activity was small or undetectable in IL-1-KO mice. These results, taken together with our previous findings (i) suggest that IL-1 is involved in the aminoBP-induced inflammatory reactions and (ii) lead us to think that under some conditions, inflammatory reactions induced by gram-negative bacteria might be augmented in patients treated with an aminoBP. In this study, we also obtained a result suggesting that IL-1-deficiency might be compensated by a second, unidentified, mechanism serving to induce HDC in response to LPS when IL-1 is lacking.

Alendronate↗
PubMed2000

Enhancement of antitumor immunity against B16 melanoma tumor using genetically modified dendritic cells to produce cytokines.

Dendritic cells (DC) that have been genetically modified to express cytokine genes may be novel tools for inducing antitumor immune responses. In the present study, the pMX retroviral vector was modified to express the mouse IL-2 (mIL-2pMX) and mouse IL-12 (mIL-12pMX) genes. Supernatants from 293 cells transfected with pMX retroviral vectors were harvested and used to transduce mouse lin- bone marrow (BM) progenitor cells. After 48 h co-culture with pseudotype retrovirus, BM cells were cultured for 12 days in the presence of mGM-CSF, mSCF and mTNF-alpha to obtain a DC-enriched fraction. Flow cytometric analysis showed that GFP protein expression in these cultures was 20-40% and that 40-50% of the cultured BM cells were positive for the DC marker, DEC205. About 60% of cells sorted for DEC205 also expressed GFP. The supernatants of DC-mIL-2 and DC-mIL-12 cultured for 48 h contained 5.2 +/- 0.15 and 33.9 +/- 2.6 ng cytokine protein per milliliter, respectively. Intratumoral injection of DC-mIL-2 or DC-mIL-12 on days 8 and 15 after the intradermal injection of 1 x 105 B16F10 cells, resulted in a significant reduction in tumor size by day 21, as compared with mice treated with unmodified DC or DC-GFP. Longer term analysis as assessed at day 42 revealed that B16 tumor-bearing mice treated with cytokine gene-modified DC survived significantly longer than mice from other groups. Spleen cells obtained from DC-treated mice were specifically sensitized for the generation of CTL by subsequent restimulation with gene-modified DC. These results suggested that DC genetically modified to express IL-2 or IL-12 can induce potent antitumor responses against well-established, poorly immunogenic B16F10 tumors. Gene Therapy (2000) 7, 2113-2121.

Animals↗
PubMed2000

Clinical evaluation of lymphoscintigraphy with a new technetium compound for metastatic cervical lymphadenopathy.

OBJECTIVES: To evaluate the potential usefulness of lymphoscintigraphy for the detection of metastatic cervical lymphadenopathy. METHODS: Dynamic and static lymphoscintigraphy with 99Tcm-HSA-D was performed in 23 patients with malignant oropharyngeal tumors. The internal jugular nodes were excised and examined pathologically. The results of the lymphoscintigraphy were compared with the pathological examination and clinical palpation for accuracy. RESULTS: All cases showed abnormal findings on lymphoscintigraphy. The accuracy on dynamic scintigraphy was 69% for asymmetric drainage, 69% for delayed drainage and 100% for inverse drainage. The overall accuracy for each side was 71%. With static scintigraphy, the accuracy was 69% for asymmetry, 86% for fitting defect, 67% for mottled-patchy appearance, 70% in swelling and 100% for collateral pathway. The overall accuracy for each side was 74%. The agreement between lymphoscintigraphy and palpation was 44%. CONCLUSIONS: Lymphoscintigraphy with 99Tcm-HSA-D was superior to palpation. The method is useful as a supplementary modality for the evaluation of metastatic cervical lymphadenopathy because of its relatively high accuracy and a low false-negative rate.

Adult↗
PubMed2000

Granulocyte colony-stimulating factor production by adult T-cell leukaemia cells.

We previously demonstrated that, in about 30% of primary adult T-cell leukaemia (ATL) cases, the leukaemic cells proliferated in response to granulocyte colony-stimulating factor (G-CSF). In the present report, we describe five patients with the acute leukaemia type of ATL who showed marked neutrophilia and elevated serum G-CSF concentrations in the absence of infection. We further examined two of these patients for detailed clinical features and cellular characteristics of the tumour cells. The white blood cell counts of both patients were 62 x 10(9)/l, consisting of approximately 90% neutrophils and 10% ATL cells. Serum concentrations of G-CSF in the two patients were 138 pg/ml and 93 pg/ml. The G-CSF concentrations in supernatants of short-term cultures of the patients' peripheral blood T-cells were 2 5 pg/ml and 13 pg/ml respectively. Immunostaining with anti-G-CSF antibody demonstrated G-CSF production by primary ATL cells in both cases. The neutrophil count fluctuated simultaneously with activity of ATL. Primary ATL cells from one patient were shown to proliferate in response to G-CSF in vitro. These results suggest autocrine growth stimulation of primary ATL cells in a subgroup of patients.

Adult↗
PubMed2000

Morphological differences in individuals with lip competence and incompetence based on electromyographic diagnosis.

The study group consisted of 19 subjects with positive overjet and overbite, and 17 subjects with skeletal open bite. Two bipolar surface electrodes were attached to the skin of the upper and lower lips. The mean integrated amplitude of the electromyographic (EMG) activity was obtained at the mandibular rest position with the lips in contact and with the lips apart. Subjects were divided into two groups based on positive or negative values of the difference in integrated EMG activity of the mentalis muscle between the two lip positions. Subjects displaying a negative value were classified as having competent lips and those displaying a positive value were classified as having incompetent lips. The EMG activity of the mentalis muscle was found to be more indicative of lip sealing as compared with the EMG activity of the depressor of the lower and the upper lips. The activities of the mentalis muscle at the mandibular rest position with the lips in contact and with the lips apart appear to offer an objective criterion for the evaluation of lip incompetence. In addition, the vertical dimension of the face, as well as the proclination of the incisors, appear to affect lower lip function.

Adult↗
PubMed2000

Stress distribution in the temporomandibular joint affected by anterior disc displacement: a three-dimensional analytic approach with the finite-element method.

The purpose of this study was to investigate the influences of anterior disc displacement on TMJ loading during maximum clenching by use of finite-element analysis. Based on a young human dry skull, an analytic model of the mandible including the TMJ was developed. In addition to the standard model with normal disc-condyle relation, two models were designed to simulate various degrees of anterior disc displacement. In the standard model, compressive stresses were induced in the anterior, middle and lateral areas on the condyle and glenoid fossa, whereas tensile stresses were observed in the posterior and medial regions. In the models with anterior disc displacement, compressive stresses were recognized in all the areas of TMJ components excluding the bilaminar zone. Shear stresses in the articular disc and bilaminar zone significantly increased in most areas. In conclusion, stress distributions in the TMJ with a normal disc position was substantially different from those with anterior disc displacement, suggesting that the progress in disc displacement may have some association with the nature of stress distributions in the TMJ, in the articular disc in particular.

Bite Force↗
PubMed2000

Mucosectomy for gastric cancer: current status in Japan.

Advances in techniques of image diagnosis have enabled the detection of minute or small cancer lesions in the stomach. Patients with such cancer, in principle, were treated surgically, but accumulated histopathological data on surgical cancer specimens revealed that many of these patients did not have any metastatic lesions. For those localized cancers, local treatment of primary lesions by endoscopy gives curative results. It has been demonstrated that endoscopic therapy is curative in mucosal well-differentiated adenocarcinoma not more than 20 mm in diameter without ulceration. Efforts to cure early gastric cancer without surgery yielded fruitful results and a new treatment concept was established. Even if there is a recurrence of the residual or metachronous lesions, they can be treated by further endoscopic treatment.

Endoscopy↗
PubMed2000

Phosphoglyceride crystal deposition disease.

An extremely rare phosphoglyceride deposition disease is reported. A healthy 62-year-old Japanese woman suffered from tumors that repeatedly appeared in injured soft tissues for more than 20 years. No immunologic disorders or abnormal laboratory data were found. Histology showed foreign body granulomas consisting of macrophages surrounding yellowish-white crystals. The crystals were weakly positive by von Kossa's method, were dissolved in 30% acetic acid with gas, and were easily dissolved in 0.1 N NaOH or potassium hydroxide, losing their crystal structure. Using a scanning electron microscopy X-ray microanalyzer, phosphorus and calcium peaks were detected. Phosphoglycerides were detected by microscopic infrared spectrophotometry and microsampling mass spectrometry. The gold hydroxamic acid method for detecting phosphoglyceride showed strong positive staining in the crystals. Based on the above analyses, the deposited crystals were regarded as phosphoglyceride, which bound calcium as a counter ion. The crystals tended to be deposited at sites of injury, where macrophages had accumulated. The patient had received many injections of a medicine made from alcohol extract from bovine liver. We suspect that this medicine was related to the cause of the deposition as the deposition repeatedly appeared at the site of the injections.

Connective Tissue↗
PubMed2000

Origin of giant cells in osteoclast-like giant cell tumors of the pancreas.

To clarify the origin of giant cells in osteoclast-like giant cell tumors (OGCTs) of the pancreas, we performed microscopical, immunohistochemical, and K-ras gene mutation analyses with a microdissection approach in 3 cases, featuring 4 cellular components (osteoclast-like giant cells [OGCs], pleomorphic large cells [PLCs], mononuclear cells, and ductal carcinoma cells). Two cases had abundant OGCs, and 1 case contained large number of both OGCs and PLCs. In each, none of the microdissected OGCs contained any K-ras gene mutation while they were positive for a histiocytic marker (CD-68). In contrast, PLCs, when present, frequently harbored K-ras gene mutations and were negative for CD-68. In all cases, mononuclear cells, a mixture of histiocyte-like and atypical, from microscopic and immunohistochemical viewpoints, also frequently showed K-ras alteration. Histiocyte-like mononuclear cell was equipped with a regular and oval nucleus similar to those in OGCs and was positive for CD-68. Atypical mononuclear cell showed an irregular, pleomorphic, or sometimes bizarre nucleus similar to those in PLCs and was negative for CD-68. All of the K-ras gene mutations found in PLCs and mononuclear cells were the same as in the ductal carcinoma cells within the same tumor. Thus, OGCs differ in origin from ductal cells and are strongly suggested to be nonneoplastic and of mesenchymal origin, whereas PLCs, which harbor K-ras gene mutations, are neoplastic and presumably derived from ductal carcinoma cells. Moreover, mononuclear cells may be classified into 2 types, histiocyte-like and atypical.

Carcinoma, Pancreatic Ductal↗
PubMed2000

Evaluation of a new enzyme immunoassay for hepatitis C virus (HCV) core antigen with clinical sensitivity approximating that of genomic amplification of HCV RNA.

The aim of this study was to analyze the clinical performance of a new enzyme immunoassay (EIA) for hepatitis C virus (HCV) core antigen in comparison with the reverse transcription polymerase chain reaction (RT-PCR). A total of 310 patients with acute or chronic hepatitis C, and 132 HCV-negative controls were studied. Chemiluminescence EIA with monoclonal anti-HCV core antigen was used, and qualitative and quantitative commercial RT-PCRs and an in-house nested RT-PCR were performed. Compared with nested RT-PCR, the core antigen assay showed 97% sensitivity and 100% specificity in 75 patients with chronic hepatitis C and 132 controls. HCV core antigen was positive in 16 (94%) of 17 patients with acute hepatitis C at initial consultation. In 3 persons prospectively followed, core antigen was detected in the first available (1-3 weeks) post-transfusion sample. In 167 anti-HCV-positive individuals, 129 (77%) were viremic; core antigen was detected in 126 (98%) compared with 129 (100%) for nested RT-PCR and 121 (94%) for the commercial RT-PCR. In 48 patients with chronic hepatitis C treated with interferon alfa, the concentration of core antigen before treatment was significantly (P <.002) lower in patients with sustained response than in nonresponders. All responders had a sustained loss of core antigen, whereas all nonresponders remained core antigen positive. The concentrations of HCV core antigen and HCV RNA correlated significantly (n = 48, r =.627, P <.001). In conclusion, the HCV core antigen assay is useful for the diagnosis of acute and chronic hepatitis C, and for predicting and monitoring the effect of interferon alfa treatment.

Acute Disease↗
PubMed2000

Sphincter of Oddi contractile function after balloon dilation: detailed manometric evaluation in conscious dogs.

BACKGROUND: Endoscopic balloon dilation is under investigation as a treatment modality for bile duct stones. It may have an advantage of preserving the sphincter of Oddi function, but little is known about sphincter of Oddi cyclic motility after dilation. METHODS: Four dogs with a duodenal cannula underwent sphincter of Oddi dilation and repeated manometry to assess sphincter of Oddi cyclic motility until 3 months after dilation. Histologic changes in the sphincter of Oddi were examined in another group of four dogs. RESULTS: Motility index (sum of amplitude of sphincter of Oddi phasic waves counted per minute) and basal pressure decreased on day 3. Sphincter of Oddi amplitude during phase III of the duodenal migrating motor complex tended to be increased on day 3 and decreased to the minimum on day 21. Thereafter, it gradually recovered to baseline. By histology, severe acute inflammation was present in the sphincter of Oddi muscle layer on day 3. However, basal pressure remained significantly low even 3 months after dilation. CONCLUSIONS: Sphincter of Oddi amplitude is incompletely reduced on day 3 after balloon dilation. Sphincter of Oddi basal pressure and motility index in the early phase of sphincter of Oddi cyclic motility remain low for at least 3 months after dilation. Further long-term follow-up is necessary to determine whether sphincter of Oddi function is actually preserved.

Animals↗
PubMed2000

Lymphoscintigraphy for interpretation of changes of cervical lymph node function in patients with oral malignant tumors: comparison of Tc-99m-Re and Tc-99m-HSA-D.

OBJECTIVE: The purpose of this study is to compare the usefulness of technetium-99m-rhenium colloid (Tc-99m-Re) and technetium-99m-human serum albumin diethylene-triamine-pentaacetic acid (Tc-99m-HSA-D) as lymphoscintigraphic agents and to discuss the significance of lymphoscintigraphy in comparison with computed tomography (CT), magnetic resonance imaging (MRI), and ultrasonography (US). STUDY DESIGN: Dynamic and static lymphoscintigraphies were performed with Tc-99m-Re and Tc-99m-HSA-D. The usefulness of the 2 agents was evaluated statistically in comparison with pathologic findings and palpation. The significance of lymphoscintigraphy is discussed in comparison with CT, MRI, and US (by the literature of CT, MRI, and US). RESULTS: Lymphoscintigraphy was superior to palpation, and Tc-99m-Re was superior to Tc-99m-HSA-D in accuracy, specificity, and the incidence of true-positive and false-positive. Statistical significance was shown between the static lymphoscintigraphy with Tc-99m-Re and palpation. The reliability of lymphoscintigraphy seemed to be slightly inferior to CT and MRI in specificity and accuracy. However, lymphoscintigraphy had some advantages that CT and MRI lacked; for example, it showed very high sensitivity (100%) and no false-negative (0%). It also showed changes of lymph node function, showed all levels of neck nodes at one time, and showed a possibility of detecting small lymph node metastases. CONCLUSION: Lymphoscintigraphy was more useful than palpation in detecting lymph node metastases, and Tc-99m-Re was superior to Tc-99m-HSA-D as an agent. Lymphoscintigraphy is significant when it is performed as a preliminary examination before CT or MRI.

Adult↗
PubMed2000

Gadolinium pretreatment decreases survival and impairs liver regeneration after partial hepatectomy under ischemia/reperfusion in rats.

BACKGROUND: Modulation of Kupffer cell functions by treatment with gadolinium chloride protects the liver against reperfusion injury. However, its effect on liver regeneration after hepatectomy under ischemia/reperfusion has not been studied. Using a common clinical ischemia/reperfusion technique, we examined the effect of gadolinium on liver regeneration after hepatectomy in rats. METHODS: After an initial 15-minute ischemia and 15-minute reperfusion, 70% hepatectomy was performed during the second 15-minute ischemia period in gadolinium-pretreated (gadolinium group) and saline solution--pretreated (control group) rats. The 24-hour survival rate, relative liver weight, DNA synthesis rate, and hepatic adenosine triphosphate level were examined immediately after hepatectomy and on postoperative days (PODs) 1, 2, 3, and 7. Serum levels of total bilirubin, glutamic pyruvic transaminase, and endotoxin were also measured. RESULTS: The 24-hour survival rate was significantly lower in the gadolinium group (67%) than in the control group (100%). On POD 1, the relative liver weight and DNA synthesis rate were significantly lower in the gadolinium group than in the control group. On POD 1, serum total bilirubin and endotoxin levels were significantly higher in the gadolinium group than in the control group. Immediately after hepatectomy, the hepatic adenosine triphosphate level was significantly lower in the gadolinium group than in the control group. CONCLUSIONS: Under ischemia/reperfusion, gadolinium pretreatment impairs liver regeneration and energy status after hepatectomy and decreases postoperative survival.

Adenosine Triphosphate↗
PubMed2000

Effect of laparotomy and laparoscopy on the establishment of lung metastasis in a murine model.

BACKGROUND: Laparoscopic surgery is now applied to patients with gastrointestinal cancer. In animal studies, extraperitoneal tumor growth has been significantly less after laparoscopy than after laparotomy, but whether hematogenous metastasis occurs less frequently after laparoscopy is unknown. The aim of this study was to compare the frequency and growth of lung metastasis and serum levels of IL-6 and tumor necrosis factor-alpha (TNF-alpha) in mice treated by laparotomy and in mice treated by laparoscopy. METHODS: We used 182 male BALB/c mice. Colon 26 cancer cells (5 x 10(4)) were injected into the tail vein, and the mice were assigned to a laparotomy group (3-cm laparotomy), a laparoscopy group (carbon dioxide pneumoperitoneum at 6 to 8 mm Hg for 30 minutes), or a control group. Lung weight, number of lung metastases, and serum levels of IL-6 and TNF-alpha were measured and compared among the 3 groups. RESULTS: The lung weight and number of metastases on the lung surface and cut section in the laparotomy group (0.44+/-0.21 g, 55.7+/-46.7, 23.0+/-19.0) were significantly larger than those in the laparoscopy group (0.32+/-0.15 g, 29.9+/- 25.5, 13.1+/-9.9) or the control group (0.28+/-0.13, 29.3+/-26.2, 11.1+/-11.1). Three hours after the procedures, the serum level of IL-6 was significantly higher in the laparotomy group (1353 +/- 790 pg/mL) than in the laparoscopy group (671+/-353 pg/mL) or the control group (333+/-341 pg/mL). The lung weight, number of lung metastases, and levels of IL-6 and TNF-alpha were not different between the laparoscopy and control groups. CONCLUSIONS: Our results indicate that, although laparotomy accelerates tumor metastasis to the lung in this murine model, laparoscopy does not increase the frequency and growth of lung metastasis. The laparoscopic approach may suppress hematogenous metastasis to the lung because of decreased surgical stress and reduced cytokine response.

Animals↗
PubMed2000

High-resolution computed tomography using multiplanar reconstruction for the facial nerve canal.

Multiplanar reconstruction (MPR) images along the facial nerve canal were prepared with high-resolution computed tomography (HRCT) and their clinical usefulness was evaluated. Over a period of 6 years, temporal bone HRCT was performed on 628 cases. Of these cases, 6 patients exhibited facial nerve lesions, including facial nerve schwannoma (n = 3), traumatic facial nerve palsy (n = 2) and congenital facial nerve palsy (n = 1). Thirty patients without facial nerve lesions, such as chronic otitis media, were randomly selected as controls. Two types of MPR image were composed. One was along the labyrinthine and tympanic segment, and the other was along the tympanic and mastoid segment. Other MPR images, such as those along the facial nerve canal and bone fracture line, were composed as needed. All MPR images were prepared with real-time observation of delicate angles. In all cases, MPR images delineated the labyrinthine and tympanic segment in one image, and the tympanic and mastoid segment in another image. In two patients with traumatic facial nerve palsy, the MPR images revealed a relationship between the facial nerve canal and the bone fracture. In conclusion, MPR images of the facial nerve canal are easy to obtain and are useful in detecting facial nerve schwannoma, traumatic facial nerve palsy and congenital facial nerve palsy.

Adolescent↗
PubMed2000

Focal ductal branch dilatation on magnetic resonance cholangiopancreatography: a hint for early diagnosis of pancreatic carcinoma.

A 63-year-old man with a combination of early pancreatic carcinoma and an intraductal papillary adenoma was reported. A pancreatic cyst was detected by chance at the head of the pancreas by computed tomography for a follow-up study of early rectal carcinoma previously operated. Detailed studies by endoscopic retrograde pancreatography (ERP) showed irregular narrowing of the main pancreatic duct at the pancreatic body and magnetic resonance cholangiopancreatography (MRCP) revealed dilatation of ductal branches draining there. Brushing cytology of the pancreatic duct demonstrated cancer cells and total pancreatectomy was performed. Stepwise histo-pathological examinations of the specimen showed two foci of invasive carcinoma in the neck and body and multiple foci of severe dysplasia, some of which contained carcinoma in situ, in the body of the pancreas. The cystic tumor in the head of the pancreas was an intraductal papillary adenoma. In this case, the scrutiny of a pancreatic cyst including MRCP and ERP led to an early diagnosis of pancreatic cancer. Dilatation of ductal branches depicted by MRCP might be a new hint for early diagnosis of pancreatic carcinoma.

Adenoma↗