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Biomedical subjects

A Ornoy

Publications and source records attributed to A Ornoy.

At least 55 records · Page 3Linked to original sources

Synthesis and preclinical pharmacology of 2-(2-aminopyrimidinio) ethylidene-1,1-bisphosphonic acid betaine (ISA-13-1)-a novel bisphosphonate.

PURPOSE: To validate our hypothesis that a bisphosphonate (BP) having a nitrogen-containing heterocyclic ring on the side chain, and with no hydroxyl on the geminal carbon would possess increased activity, and better oral bioavailability due to enhanced solubility of its calcium complexes/salts and weaker Ca chelating properties. METHODS: A novel BP, 2-(2-aminopyrimidinio)ethylidene-1, 1-bisphosphonic acid betaine (ISA-13-1) was synthesized. The physicochemical properties and permeability were studied in vitro. The effects on macrophages, bone resorption (young growing rat model), and tumor-induced osteolysis (Walker carcinosarcoma) were studied in comparison to clinically used BPs. RESULTS: The solubility of the Ca salt of ISA-13-1 was higher, and the log beta(Ca:BP) stability constant and the affinity to hydroxyapatite were lower than those of alendronate and pamidronate. ISA-13-1 exhibited effects similar to those of alendronate on bone volume, on bone osteolysis, and on macrophages, following delivery by liposomes. ISA-13-1 was shown to have 1.5-1.7 times better oral absorption than the other BPs with no deleterious effects on the tight junctions of intestinal tissue. CONCLUSIONS: The similar potency to clinically used BPs, the increased oral absorption as well as the lack of effect on tissue tight junction of ISA-13-1 warrant its further consideration as a potential drug for bone diseases.

Administration, Oral↗

Neurodevelopmental outcome at early school age of children born to mothers with gestational diabetes.

AIMS: To study the metabolic derangements in the second half of pregnancy caused by gestational diabetes, on the long term development of children. METHODS: The neuropsychological function of 32 school age children born to 32 mothers with well controlled gestational diabetes and 57 control children matched by age, birth order, and parental socioeconomic status was studied. RESULTS: There were no differences in head circumference and height, but the children born to diabetic mothers were heavier. The verbal IQ scores of index children below the age of 9 years were lower than those of control children. No differences were found between the groups in various sensory and motor functions and in the Touwen and Prechtl neurological test. The young index group children performed less well than controls in fine and gross motor functions, as observed on the Bruininks-Oseretzky test of motor proficiency. The scores of young children born to mothers with gestational diabetes were also lower than controls on the Pollack tapper test, and there were more index group children who scored abnormally on the parents' Conners questionnaire. No correlation was found between the performance of the index group children on various neurodevelopmental tests and the severity of perinatal complications. The differences tended to disappear with age. CONCLUSIONS: Gestational diabetes, as a result of the metabolic abnormalities in the second half of pregnancy, induces long term minor neurological deficits which are more pronounced in younger children. There does not seem to be any direct relation between the appearance of congenital anomalies and neurodevelopmental outcome.

Child↗

The expression of transforming growth factor-beta and interleukin-1beta mRNA and the response to 1,25(OH)2D3' 17 beta-estradiol, and testosterone is age dependent in primary cultures of mouse-derived osteoblasts in vitro.

The aim of the present study was to examine the hypothesis that primary cultures of osteoblasts obtained from bones of young animals respond to hormones better than cell cultures obtained from old animals. We studied in cultured osteoblastic cells the effects of 1,25(OH)2D3 and sex steroid hormones on several mouse osteoblastic phenotypic expressions including transforming growth factor-beta (TGF-beta) and interleukin-1beta (IL-1beta) mRNAs. Second passages of long bone-derived osteoblastic cells from young donors (5-12 wk) and old donors (10-12 mo old) were used for this study. The cells obtained from old animals had decreased ALP activity and cAMP compared with cells obtained from young animals with no change in collagen production and mineralization. The addition of 17beta-estradiol and testosterone increased ALP activity and mineralization in the cultured cells from both age groups and collagen production in cells obtained from old mice. Using in situ hybridization IL-1beta and TGF-beta mRNA expression was observed to be higher in the osteoblasts from young than from old donors. 1,25(OH)2D3 increased IL-1beta mRNA expression in the cells derived from young mice. Testosterone and 17beta-estradiol inhibited IL-1beta mRNA expression only in cells derived from young mice. Sex steroid hormones did not change TGF-beta mRNA expression in any of the cell lines, but 1,25(OH)2D3 increased its expression in cells derived from old donors. The results of the present study indicate that cells obtained from old mice are generally less active than those obtained from young animals.

Aging↗

Transforming growth factor-beta1 modulates chondrocyte responsiveness to 17beta-estradiol.

This study examined the interrelationship between transforming growth factor-beta1 (TGF-beta1) and 17beta-estradiol (E2) in the regulation of growth plate chondrocytes. To determine whether TGF-beta1 modulates chondrocyte response to E2, we used cells isolated from the resting zone (RC) and growth zone (GC) of costochondral cartilage. Confluent, fourth-passage cultures were pretreated with rhTGF-beta1 for 24 h, followed by treatment with E2 for 24 h. The effect of TGF-beta1 and E2 alone, or the sequential combination, were examined by measuring [3H]-thymidine incorporation (proliferation), alkaline phosphatase (AP) specific activity (differentiation), and [35S]-sulfate incorporation (matrix synthesis). TGF-beta1 alone increased [3H]-thymidine incorporation in both female and male RC and GC cells, but E2 affected this parameter only in RC cells, causing a dose-dependent decrease. At the highest concentration of TGF-beta1 and E2, [3H]-thymidine incorporation in female GC cells was the same as seen in untreated control cultures. In male GC cells, [3H]-thymidine incorporation in cultures treated with TGF-beta1 and E2 exhibited a comparable increase, as was seen in cultures treated with TGF-beta1 alone. TGF-beta1 caused a biphasic stimulation in AP that was maximal at 0.22 ng/mL, in both female and male RC and GC cells. E2, however, affected only female cells. Whereas the effect of TGF-beta1 predominated in RC and GC male cells, the biphasic stimulation caused by E2, maximal at 109 M, predominated in female RC cells. In female GC cells, however, TGF-beta1 caused a synergistic response, resulting in enhanced AP specific activity in cultures pretreated with 0.22 ng/mL of TGF-beta1 and 10(-8) M E2. TGF-beta1 alone caused dose-dependent increases in [35S]-sulfate incorporation in female RC and GC cells, as well as in male GC cells, but had no effect on male RC cells. E2 affected only female cells. TGF-beta1 potentiated the effect of E2 on this parameter, resulting in synergistic increases in the female cells. This is the first demonstration of a gender-specific response to TGF-beta1 in chondrocytes. These results suggest that chondrocyte response to a systemic hormone such as E2 can be modulated by local regulatory agents such as TGF-beta1.

Alkaline Phosphatase↗

Growth plate chondrocytes store latent transforming growth factor (TGF)-beta 1 in their matrix through latent TGF-beta 1 binding protein-1.

Osteoblasts produce a 100 kDa soluble form of latent transforming growth factor beta (TGF-beta) as well as a 290 kDa form containing latent TGF-beta binding protein-1 (LTBP1), which targets the latent complex to the matrix for storage. The nature of the soluble and stored forms of latent TGF-beta in chondrocytes, however, is not known. In the present study, resting zone and growth zone chondrocytes from rat costochondral cartilage were cultured to fourth passage and then examined for the presence of mRNA coding for LTBP1 protein. In addition, the matrix and media were examined for LTBP1 protein and latent TGF-beta. Northern blots, RT-PCR, and in situ hybridization showed that growth zone cells expressed higher levels of LTBP1 mRNA in vitro than resting zone cells. Immunohistochemical staining for LTBP1 revealed fine fibrillar structures around the cells and in the cell matrix. When the extracellular matrix of these cultures was digested with plasmin, LTBP1 was released, as determined by immunoprecipitation. Both active and latent TGF-beta1 were found in these digests by TGF-beta1 ELISA and Western blotting. Immunoprecipitation demonstrated that the cells also secrete LTBP1 which is not associated with latent TGF-beta, in addition to LTBP1 that is associated with the 100 kDa latent TGF-beta complex. These studies show for the first time that latent TGF-beta is present in the matrix of costochondral chondrocytes and that LTBP1 is responsible for storage of this complex in the matrix. The data suggest that chondrocytes are able to regulate both the temporal and spatial activation of latent TGF-beta, even at sites distant from the cell, in a relatively avascular environment.

Animals↗

Bisphosphonates and tetracycline: experimental models for their evaluation in calcium-related disorders.

PURPOSE: This work was aimed at synthesizing novel bisphosphonates (BPs) and examining them in comparison to clinically used BPs such as pamidronate and alendronate, and to tetracycline, in order to evaluate their potential as anticalcification and antiresorption agents. The correlation between the various models was examined in order to establish facile experimental models for pre-screening of potential compounds. METHODS: Nitrogen-containing heterocyclic, novel BPs such as 2-(3-methylimidazolio) ethylidene-1,1-bisphosphonic acid betaine (VS-5b), 2-(2-dimethylamino-4-pyrazinio)ethylidene-1,1-bisphosphonic acid betaine (VS-6b), and 2-(2-alpha-pyridylethylthio) ethylidene-1,1-bisphosphonic acid (ISA-225), were synthesized and evaluated in comparison to clinically used BPs, in various experimental models of resorption and calcification. RESULTS: The physicochemical properties of the novel compounds are slightly different than the BPs in clinical use: the pKa values are lower, the affinity for hydroxyapatite is lower and the solubilities of the calcium salts are higher. The anticalcification potencies of the novel compounds were high and ranked as follows: alendronate = pamidronate > VS-6b = VS-5b = ISA-225 > tetracycline. The in vivo antiresorption activity of VS-5b and VS-6b in comparison to that of the clinically employed, pamidronate, was shown to be similar and higher, respectively. CONCLUSIONS: The anticalcification activity of the novel compounds as well as that of tetracycline was lower than that of alendronate. The antiresorption activity of VS-6b was similar to that of pamidronate. A good correlation between the different models was found, enabling the facile screening of novel compounds. The activities of tetracycline and EDTA highlight the distinct behavior of BPs as "crystal poison." In addition, tetracycline was found to be a potent anticalcification agent in the ectopic calcification model.

Alendronate↗

Developmental correlates of school-age children with a history of benign congenital hypotonia.

In order to clarify the prognosis of benign congenital hypotonia (BCH), 25 children aged 6 to 8 years who had been diagnosed with BCH as infants were examined on a variety of sensory, perceptual-motor, and behavioural measures and compared with 26 control children. There were no significant differences between the two groups on any of the medical or neurological measures of the Touwen Neurological Examination (Touwen 1979), nor were there significant overall differences on any of the sensory or behavioural measures. However, the BCH group showed inferior gross motor performance on the Bruininks-Oseretsky Test of Motor Proficiency (Bruininks 1978). They scored significantly lower on the Gross Motor Composite, and performed worse on each of the four Gross Motor Subtests, reaching significance on two: Bilateral Coordination and Strength. The follow-up of children with BCH should continue even after the apparent resolution of the hypotonia, with particular attention to the gross motor aspects of performance.

Child↗

Neurobehaviour of school age children born to diabetic mothers.

AIM: To study the neurobehavioural effects that diabetes during pregnancy might have on children by school age. METHODS: The neurobehavioural function of 57 school age children born to 48, well controlled diabetic mothers was compared with 57 control children matched for age, birth order, and parental socioeconomic status, using several cognitive, behavioural, sensory and motor neurological tests. RESULTS: The IQ scores of the index group children were similar to those of control children (117.7 +/- 13.4 vs 118.5 +/- 10.1). There were no differences between the groups in various sensory motor functions. However, the index group children performed less well than the controls on indices of fine and gross motor functions, as observed on the Bruininks-Oseretzky test of motor proficiency. The scores of children born to diabetic mothers were higher than controls on the Touwen and Prechtl neurological examination. They also performed worse in the Pollack tapper test which is designed to detect minor neurological deficits, inattention, and hyperactivity. The index children had higher scores on the Conners abbreviated parent-teacher questionnaire which measures hyperactivity and inattention. There was a negative correlation between the performance of the index group children on various neurodevelopmental and behavioural tests and the severity of hyperglycaemia, as assessed by blood glycosylated haemoglobin and acetonuria. CONCLUSIONS: Diabetes during pregnancy adversely affects some fine neurological functions in children at school age, but not their cognitive scores. These effects are not correlated with the degree of glycaemic control.

Child↗

Is early intervention effective in preventing ADHD?

The purpose of this study was to examine whether early intervention by non-pharmacologic means (occupational therapy and speech therapy) can decrease the incidence of ADHD in a group of preschool children at high risk for developing this syndrome. Fifty-one children who suffered at the age of 2-4.5 years from inattention, speech delay and/or motor delay with or without hyperactivity were reexamined at the age of 8-10 years (average 8.9 +/- 1.0 years) by a developmental pediatrician and a developmental psychologist, using the following tests and questionnaires: WISC-R IQ test, Touwen and Prechtl neurological examination for soft neurological signs and the DSM-III-R questionnaire for parents and teachers for the assessment of inattention and hyperactivity. A detailed medical questionnaire was also completed. Of 51 children, 20 (39%) had ADHD. Of these 20 children, 8 had a history of ADHD in other siblings. We found that in children with a family history of this syndrome early intervention reduced the incidence of ADHD at school age although the small numbers limit conclusions and need further replication.

Analysis of Variance↗

The effects of 17 beta-estradiol on chondrocyte differentiation are modulated by vitamin D3 metabolites.

Both 17 beta-estradiol (17 beta) and the vitamin D metabolites, 1,25-(OH)2D3(1,25) and 24,25-(OH)2D3(24,25), regulate endochondral bone formation in vivo and in vitro. The effects of 17 beta are sex-specific and cell maturation-dependent. Similarly, the effects of 1,25 and 24,25 are cell maturation-dependent, with 1,25 affecting growth zone chondrocytes (GC) and 24,25 affecting resting zone chondrocytes (RC). This study examined whether the response of chondrocytes to 17 beta is altered after pretreatment with 1,25 or 24,25. Cells were isolated from the costochondral cartilage of male or female rats. Confluent, fourth-passage GC and RC cultures were pretreated with 1,25 or 24,25, respectively, for 24 or 48 h followed by treatment with 17 beta for an additional 24 h. At harvest, cell proliferation ([3H]-thymidine incorporation), differentiation (alkaline phosphatase specific activity [ALPase]), general metabolism ([3H]-uridine incorporation), and proteoglycan production ([35S]-sulfate incorporation) were determined. 1,25 enhanced the inhibitory effect of 17 beta on [3H]-thymidine incorporation by female GC cells; in contrast, no effect was observed in GC cells obtained from male rats. When male RC cells were treated with 17 beta, [3H]-thymidine incorporation was inhibited; however, when these cells were pretreated with 24,25 for 48 h, 17 beta stimulated [3H]-thymidine incorporation 24,25 had no effect on 17 beta-dependent [3H]-thymidine incorporation by female RC cells. 17 beta stimulated ALPase in female GC cells, but had no effect on male GC cells. 1,25 pretreatment of female GC cells inhibited the stimulatory effect of 17 beta on ALPase, but had no effect on ALPase in male GC cultures. 17 beta had no effect on male RC cell ALPase and stimulated ALPase in female RC cells. This was not affected by pretreatment with 24,25. Pretreatment with 1,25 increased the basal level of sulfate incorporation only in female GC. No effect was found in RC cells. These results indicate that pretreatment of rat costochondral chondrocytes with vitamin D metabolites modulate the effect of 17 beta. Although the effect of vitamin D metabolites alone on these chondrocytes is maturation-dependent and not sex-specific, the influence of preincubation with vitamin D metabolites on the effect of 17 beta is hormone-specific, sex-specific, and maturation-dependent.

24,25-Dihydroxyvitamin D 3↗

Estrogen, progesterone and testosterone receptors in human fetal cartilaginous tissue: immunohistochemical studies.

Computerized image analysis was used to study the distribution in cartilage of receptors to estrogen, progesterone, and testosterone during human fetal development. We have examined three histologically distinct cell groups (hypertrophic, proliferating, and reserve zones) in long bones, vertebrae, and trachea from 19 fetuses. Comparisons were made across gender and gestational age. Contrasting with controls, we examined the density of receptors, the size of the nuclear area in which the receptors were detected, the number of hormone receptor-bearing cells, and the total receptor quantity per sample. We found that estrogen, progesterone, and testosterone receptors were detected in the nuclei of all cell types, in both female and male embryonic cartilaginous tissue. Gender differences were small and inconsistent. Changes associated with gestational age depicted a pattern of hormone receptor manifestation, shifting from the immature cell types to more differentiated cells. This was evident from the receptor densities and from the cellular area in which receptors were sighted. These dynamics are accompanied by a general increase in receptor content per sample, brought about by the concomitant increase in receptor containing area size and cell number. The increase in receptor levels seems to reflect the maturation and growth of the fetal skeleton.

Cartilage↗

In vitro and in vivo effects of tetrakisphosphonates on bone resorption, tumor osteolysis, ectopic calcification, and macrophages.

The biological effects of bisphosphonates in calcium-related disorders are attributed to the incorporation of the bisphosphonates in bone, enabling direct interaction with osteoclasts and/or osteoblasts. The high accumulation of bisphosphonates in bone, due to their high affinity to hydroxyapatite (HAP), is essential for mediating in vitro and in vivo activity. In this study we examined the activity of tetrakisphosphonates, molecules containing two P-C-P type bisphosphonate moieties connected by a carbon chain. The novel compounds were examined in a battery of in vitro and in vivo models including HAP formation and dissolution, ectopic calcification, bone resorption, tumor osteolysis, and of macrophage-like cells (anti- or pro-inflammatory properties). The inhibition of ectopic calcification was ranked as follows: geminal bisphosphonates > bisacylphosphonates > tetrakisphosphonates. Pamidronate, but not the tetrakisphosphonates, was an effective antiosteolytic agent. Neither DNTP (tetrasodium 1,9-dihydroxynonane 1,1,9,9-tetrakisphosphonate) nor the bisacylphosphonate, PiBP (pimeloylbisphosphonate) seem to possess strong macrophage suppressive or inductive effects and can be considered to be relatively inactive in terms of anti- or pro-inflammatory action. A significant anticalcification effect was caused by various phosphonates, such as the tetrakisphosphonates, but DNTP, a tetrakisphosphonate, was found toxic as it impeded somatic growth and bone development.

Animals↗

Effects of continuous or cyclic administration of pamidronate on the skeleton in intact and oophorectomized young rats.

Bisphosphonates are potent inhibitors of bone resorption, and are therefore used for the treatment of various bone diseases including osteoporosis. We examined whether cyclic therapy with bisphosphonates in oophorectomized osteoporotic rats had any advantage over continuous treatment. We therefore treated intact and oophorectomized young female rats for 8 weeks with 1 and 5 mg/kg/day of pamidronate. The 8-week treatment was given continuously for 6 days/week or intermittently, i.e. 6 days of pamidronate (APD) and 3 weeks off, for 2 cycles. We found an increase in tibial wet and ash weight and in the mineral content in oophorectomized rats treated continuously or intermittently with APD in comparison to nontreated oophorectomized animals. Histomorphometric analysis showed an increase in the volume of metaphyseal cartilage and bone. No changes were found in the volume of epiphyseal or diaphyseal bone. Pamidronate had very little effect on the bone of intact rats. Pamidronate seems to be more effective in inhibiting bone resorption in bone that undergoes rapid turnover (i.e. in oophorectomized animals) when compared to bone with low turnover (intact rats). Although the results of cyclic treatment were similar to those of continuous treatment, we have to remember that cyclic therapy may be more advantageous since animals receiving cyclic therapy received only 25% of the dose of rats continuously treated.

Animals↗

Thomas syndrome: potter sequence with cleft lip/palate and cardiac anomalies.

Holzgreve et al. [Am J Med Genet 18:177-184, 1984] first reported on a syndrome including renal anomalies, heart defect, polydactyly, and cleft palate with other oropharyngeal anomalies. We report here on four sibs with renal adysplasia associated in two with cardiovascular malformations and cleft lip or cleft palate in two. We propose that these patients as the two siblings reported by Thomas et al. [Am J Med Genet 45:767-769, 1993] are affected with a syndrome different of the one described by Holzgreve et al. [Am J Med Genet 18:177-184, 1984] mainly because of the absence of polydactyly. Thomas syndrome is probably inherited as an autosomal recessive trait with marked variability.

Abnormalities, Multiple↗

The developmental outcome of children born to heroin-dependent mothers, raised at home or adopted.

In the present investigation we were interested to study the possible role of in-utero exposure to heroin and of the home environmental in the etiology of long-term developmental problems in children born to heroin-dependent parents in comparison to matched controls. The children were examined at .5-6 years of age by a developmental pediatrician and a developmental psychologist using, for the children up to 2.5 years of age, the Bayley Developmental Scales, and for children aged 3-6 years the McCarthy Scales for Children's Abilities. We examined 83 children born to heroin-dependent mothers, and compared the results to those of 76 children born to heroin-dependent fathers and to three control groups; 50 children with environmental deprivation, 50 normal children from families of moderate or high socioeconomic class, without environmental deprivation, and 80 healthy children from kindergartens in Jerusalem. There were five children (6.0%) with significant neurological damage among the children born to heroin-dependent mothers and six (7.9%) children among those born to heroin-dependent fathers. The children born to heroin-dependent mothers had a lower birth weight and a lower head circumference at examination when compared to controls. The children born to heroin-dependent parents also had a high incidence of hyperactivity, inattention, and behavioral problems. The lowest DQ or IQ among the children with cognitive levels above 70 was found in the children with environmental deprivation, next was the DQ or IQ of children born to heroin-dependent fathers, then the DQ or IQ of the children born to heroin-dependent mothers. When the children born to heroin-dependent mothers were divided to those that were adopted at a very young age and to those raised at home, the adopted children were found to function similarly to the controls while those not adopted functioned significantly lower. Our results show that the developmental delay and behavioral disorders observed among children born to drug-dependent parents raised at home may primarily result from severe environmental deprivation and the fact that one or both parents are addicted. The specific role of the in-utero heroin exposure in the determination of the developmental outcome of these children (if they do not have significant neurological damage), seems to be less important in comparison to the home environment.

Abnormalities, Drug-Induced↗

Pregnancy outcome after prenatal quinolone exposure. Evaluation of a case registry of the European Network of Teratology Information Services (ENTIS).

OBJECTIVE: To study potential teratogenic effects of quinolone exposure during pregnancy. STUDY DESIGN: Prospective follow-up study. Subjects are pregnant women who contacted a teratology information center for risk information on quinolone treatment. A total of 549 pregnancies was collected by the European Network of Teratology Information Services between 1986 and 1994. In addition 116 prospectively documented pregnancies and 25 retrospective case reports on malformed children from other databases were analyzed. RESULTS: The malformation rate among the live-born babies in the prospective ENTIS cohort was approximately 4.8%. No specific patterns of congenital abnormalities were found. The results do not suggest an elevated risk for spontaneous abortion, prematurity, intrauterine growth retardation and postnatal disorders. CONCLUSION: The present study does not reveal any clear adverse reactions (fetal and neonatal toxicity, including birth defects) due to the in utero exposure to quinolones. Hence, termination of pregnancy because of such exposure is not indicated. However, considering the limitations of this study and the fact that diseases urgently requiring quinolone treatment are rare, it appears advisable to prefer penicillin, cephalosporins and erythromycin as antibiotics of choice.

4-Quinolones↗

Congenital cytomegalovirus infection: a long-standing problem still seeking a solution.

OBJECTIVE: The purpose of this study was to review the accuracy of current tests used for the diagnosis of in utero cytomegalovirus infection and to discuss the potential value of preconceptional and postconceptional screening programs for prevention of congenital infection. STUDY DESIGN: A computer-assisted search was performed for relevant English language publications between 1987 and 1994. We identified 119 cases of suspected intrauterine cytomegalovirus infection in which either amniotic fluid or fetal blood had been analyzed antenatally. RESULTS: Congenital cytomegalovirus infection affects 0.5% to 2.5% of all newborns. The rate of transmission to the fetus after primary infection during pregnancy ranges from 15% to 50%. Of the fetuses infected in utero, 10% exhibit congenital cytomegalovirus syndrome. Evaluation of 119 cases of suspected infection has shown that polymerase chain reaction and cultures of amniotic fluid are the most reliable tests for prenatally determining the presence of viral particles. However, efficacy of routine antenatal screening in reducing the rate of fetal disease is limited. CONCLUSION: It is concluded that at present the accuracy of tests used for the diagnosis of in utero cytomegalovirus infection is undetermined. Serologic screening of all pregnant women is of limited value and at present is not recommended.

Amniotic Fluid↗