Biomedical subjects

H Y Li

Publications and source records attributed to H Y Li.

At least 37 records · Page 2Linked to original sources

PubMed2000

Distribution of mRNAs encoding CRF receptors in brain and pituitary of rat and mouse.

Two G protein-coupled receptors have been identified that bind corticotropin-releasing factor (CRF) and urocortin (UCN) with high affinity. Hybridization histochemical methods were used to shed light on controversies concerning their localization in rat brain, and to provide normative distributional data in mouse, the standard model for genetic manipulation in mammals. The distribution of CRF-R1 mRNA in mouse was found to be fundamentally similar to that in rat, with expression predominating in the cerebral cortex, sensory relay nuclei, and in the cerebellum and its major afferents. Pronounced species differences in distribution were few, although more subtle variations in the relative strength of R1 expression were seen in several forebrain regions. CRF-R2 mRNA displayed comparable expression in rat and mouse brain, distinct from, and more restricted than that of CRF-R1. Major neuronal sites of CRF-R2 expression included aspects of the olfactory bulb, lateral septal nucleus, bed nucleus of the stria terminalis, ventromedial hypothalamic nucleus, medial and posterior cortical nuclei of the amygdala, ventral hippocampus, mesencephalic raphe nuclei, and novel localizations in the nucleus of the solitary tract and area postrema. Several sites of expression in the limbic forebrain were found to overlap partially with ones of androgen receptor expression. In pituitary, rat and mouse displayed CRF-R1 mRNA signal continuously over the intermediate lobe and over a subset of cells in the anterior lobe, whereas CRF-R2 transcripts were expressed mainly in the posterior lobe. The distinctive expression pattern of CRF-R2 mRNA identifies additional putative central sites of action for CRF and/or UCN. Constitutive expression of CRF-R2 mRNA in the nucleus of the solitary tract, and stress-inducible expression of CRF-R1 transcripts in the paraventricular nucleus may provide a basis for understanding documented effects of CRF-related peptides at a loci shown previously to lack a capacity for CRF-R expression or CRF binding. Other such "mismatches" remain to be reconciled.

Animals↗

PubMed2000

Anatomical subdivisions of the stomach of the Bactrian camel (Camelus bactrianus).

Twenty stomachs of Bactrian camels (Camelus bactrianus) were studied by gross dissection. Based on the configuration of the stomach and the structure of the mucous membrane, the stomach was divided into three ventricles that differ from the arrangement described for ox and sheep. The first and second ventricles of the proventriculus of camel form one stomach rather than two different stomachs. These ventricles of the proventriculus do not correspond to the rumen and reticulum of ox and sheep. The third ventricle appears to be the abomasum. One part of the abomasum has reticular mucosal folds that indicate it is not the reticulum. A second part of the abomasum has longitudinal mucosal folds suggesting it is not the omasum. Three glandular sac areas associated with the preventriculus and abomasum are also described.

Abomasum↗

PubMed2000

Circuits and mechanisms governing hypothalamic responses to stress: a tale of two paradigms.

The results of recent studies support a partitioning of stress models into at least two basic classes. While these have been referred to as 'systemic' and 'neurogenic', we would suggest that the terms interoceptive and exteroceptive, respectively, are more apt descriptors. This is based on the similarities in the overall patterns of activational responses seen as a consequence of exposure to a range of perturbations in the internal versus external environments. While stressors of each class may share in common such fundamental features as a capacity to enlist certain PVH effector populations and medullary catecholamine-containing neurons, both the capacity to involve specific output neuron classes and the dependence of hypothalamic effects on the integrity of aminergic afferents in at least some interoceptive and exteroceptive models, are clearly differential. The available evidence suggests that interoceptive stress effects on PVH effector populations may be conceived essentially as simple reflex responses, mediated at a subcortical level by cell groups and associated circumventricular organs that comprise the core of a system involved in the processing of visceral sensory information. Based on the general pattern of acute footshock-induced Fos expression and commonalities of cellular activation profiles seen in this and other acute exteroceptive paradigms, it seems a reasonable assumption that pathways that convey somatosensory/nociceptive information to the PVH are apt to mediate adaptive visceromotor responses in these models. Multiple candidates for such roles have been identified at various levels of what may be viewed as the ascent of the spinothalamic pathway through the brainstem and thalamus, and on through the limbic forebrain and hypothalamus. Dissecting the relative contributions of these in determining PVH output will speak to important conceptual issues concerning the extent to which the affective and visceromotor responses to exteroceptive stressors are organized, and the level(s) at which these different avenues of emotional expression may be integrated.

Animals↗

PubMed2000

The arterial supply of the cubital joint in the Bactrian camel (Camelus bactrianus).

The arterial supply of the six cubital joints from bactrian camels was studied. There were 15 arterial branches supplying the joint. The branches that arose from the transverse cubital artery were the medial anterior, superior anterior, lateral anterior, middle anterior, inferior anterior, superior lateral, middle lateral, inferior lateral, superior posterior and superior lateral posterior cubital branches. The branches originating from the collateral ulnar artery were the medial, middle posterior, inferior posterior, medial posterior and inferior lateral posterior cubital branches. These arteries united with each other around the cubital joint.

Animals↗

PubMed2000

The arterial supply of the carpal joint in the Bactrian camel (Camelus bactrianus).

The arterial supply of the six carpal joints was studied in Bactrian camels. The arterial branches supplying the carpal joints were the proximal medial dorsal, middle medial dorsal, distal medial dorsal, proximal lateral dorsal, distal lateral dorsal, proximal medial palmar, distal medial palmar, lateral palmar, proximal palmar and dorsal palmar carpi and the dorsal interosseous antebrachium branches. Some small unnamed branches supplied the diverticulum and the antebrachiocarpal joint capsule. All these arteries arose from the lateral and medial branches of the radial artery.

Animals↗

PubMed2000

Single amino acid substitutions at the acyl-CoA-binding domain interrupt 14[C]palmitoyl-CoA binding of ACBP2, an Arabidopsis acyl-CoA-binding protein with ankyrin repeats.

Cytosolic acyl-CoA-binding proteins (ACBPs) are small proteins (ca. 10 kDa) that bind long-chain acyl-CoAs and are involved in the storage and intracellular transport of acyl-CoAs. Previously, we have characterized an Arabidopsis thaliana cDNA encoding a novel membrane-associated ACBP, designated ACBP1, demonstrating the existence of a new form of ACBP in plants (M.-L. Chye, Plant Mol. Biol. 38 (1998) 827-838). ACBP1 likely participates in intermembrane lipid transport from the ER to the plasma membrane, where it could maintain a membrane-associated acyl pool (Chye et al., Plant J. 18 (1999) 205-214). Here we report the isolation of cDNAs encoding ACBP2 (Mr 38,479) that shows conservation in the acyl-CoA-binding domain to previously reported ACBPs, and contains ankyrin repeats at its carboxy terminus. These repeats, which likely mediate protein-protein interactions, could constitute a potential docking site in ACBP2 for an enzyme that uses acyl-CoAs as substrate, in vitro binding assays on recombinant (His)6-ACBP2 expressed in Escherichia coli show that it binds 14[C]palmitoyl-CoA preferentially to 14[C]oleoyl-CoA. Analysis of the acyl-CoA-binding domain in ACBP2 was carried out by in vitro mutagenesis. Mutant forms of recombinant (His)6-ACBP2 with single amino acid substitutions at conserved residues within the acyl-CoA-binding domain were less effective in binding 14[C]palmitoyl-CoA. Northern blot analysis showed that the 1.6 kb ACBP2 mRNA, like that of ACBP1, is expressed in all plant organs. Analysis of the ACBP2 promoter revealed that, like the ACBP1 promoter, it lacks a TATA box suggesting the possibility of a housekeeping function for ACBP2 in plant lipid metabolism.

Acyl Coenzyme A↗

PubMed2000

The arterial supply to the digits of the forelimb in the Bactrian camel (Camelus bactrianus).

The arterial supply of the digits of the forelimb of the Bactrian camel is described. The arteries supplying the digits were the palmar metacarpal and common palmar digital arteries III. The palmar metacarpal artery III was the continuation of the deep medial proximal metacarpal branch which was derived from the medial branch of the radial artery. It gave rise to a nutrient branch, medial branch, lateral branch and distal perforating palmar branch at the proximal end of the distal sixth of the cannon bone (fused third and fourth metacarpal bones). The common palmar digital artery III was the continuation of the median artery, which divided into medial and lateral branches. The medial branch of common palmar digital artery III which occasionally arose from the axial palmar proper digital artery III, after giving rise to the axial proximal proximal phalangeal branch, divided into the axial and abaxial palmar proper digital arteries III. The axial palmar proper digital artery III gave off the dorsoaxial distal proximal phalangeal, dorsoaxial proximal middle phalangeal, dorsoaxial distal middle phalangeal, palmoaxial middle phalangeal, palmoaxial distal phalangeal, dorsoaxial distal phalangeal branches, coronal artery and some digital tori branches. The abaxial palmar proper digital artery III gave rise to the abaxial proximal proximal phalangeal, dorsoabaxial distal proximal phalangeal, dorsoabaxial middle phalangeal, palmoabaxial middle phalangeal, palmoabaxial distal phalangeal, dorsoabaxial distal phalangeal branches, coronal artery and some digital tori branches. The lateral branch of the common palmar digital artery III in its origin, course, branching pattern and supply in the fourth digit was similar to the medial branch of common palmar digital artery III in the third digit.

Adaptation, Physiological↗

PubMed2000

Enhanced responses to 17beta-estradiol in rat hearts treated with isoproterenol: involvement of a cyclic AMP-dependent pathway.

We determined the effects of 17beta-estradiol, the most effective estrogen, acutely administered, on the heart/ventricular myocyte with or without treatment with isoproterenol (Iso). At 0.1 to 1 nM, 17beta-estradiol, which itself had no effect, reduced the heart rate and developed pressures in the isolated perfused heart treated with 10(-7) M Iso. One nanomolar 17beta-estradiol also inhibited the cyclic AMP (cAMP) production in Iso-treated ventricular myocytes. At 10 nM to 1 microM, 17beta-estradiol itself reduced the heart rate and incidence of ischemia/reperfusion-induced arrhythmias, with the exception of diastolic pressure. The effects of 17beta-estradiol on heart rate, systolic and mean pressures, and arrhythmias were significantly enhanced in the heart/ventricular myocyte treated with Iso. Tamoxifen, an estrogen receptor antagonist, did not antagonize the effect of 17beta-estradiol on the Ca(2+) current in ventricular myocytes treated with Iso, nor did it alter the effect of the hormone on the cAMP production augmented by Iso and forskolin. The effects of 17beta-estradiol on Ca(2+) current in the presence or absence of tamoxifen and/or Iso were similar in male rats, which do not possess the estrogen receptor, and female rats, which have the estrogen receptor. In conclusion, we have shown for the first time that estrogen at physiological concentrations modulates negatively the stimulatory actions of Iso on the heart rate and cardiac contractility. The effects may result from activation of an unknown membrane receptor and the adenylate cyclase/cAMP pathway, which enhances Ca(2+) influx across the L-type Ca(2+) channel.

Adrenergic beta-Agonists↗

PubMed2000

Vaginal fluid creatinine, human chorionic gonadotropin and alpha-fetoprotein levels for detecting premature rupture of membranes.

BACKGROUND: Diagnosis of premature rupture of membranes (PROM) is difficult in equivocal cases. The concentrations of human chorionic gonadotropin (hCG), alpha-fetoprotein (AFP) and creatinine are high in amniotic fluid. The purpose of this study was to determine the usefulness of vaginal fluid hCG, AFP and creatinine measurements in the detection of PROM. METHODS: About 3 ml of normal saline was used to irrigate the posterior vaginal fornix and was collected for the measurement of hCG, AFP and creatinine. The control group included 10 normal pregnant women in the third trimester (> 28 weeks of gestational age). Levels of hCG, AFP and creatinine were compared with those of 10 women with confirmed PROM. RESULTS: The median levels of vaginal fluid hCG of normal pregnant women and pregnant women with confirmed PROM were 35.0 mIU/ml and 478.0 mIU/ml (p = 0.0046), respectively. For AFP, the corresponding values were 0.80 ng/ml and 54.24 ng/ml (p < 0.0001), respectively, and for creatinine, the values were 0.05 mg/dl and 0.95 mg/dl (p < 0.0001), respectively. All three markers were significantly higher in the experimental group than in the control group. The sensitivity, specificity, positive predictive value, negative predictive value and accuracy for hCG were 80%, 70%, 72.7%, 77.8% and 75%, respectively. For AFP, these values were 90%, 100%, 100%, 90.9%, and 95.0%, respectively, and for creatinine, they were 90%, 100%, 100%, 90.9%, and 95%, respectively. The diagnostic value of AFP or creatinine level in vaginal washing may be better than that of hCG, though the difference was not statistically significant, probably due to the limited case number. CONCLUSIONS: Creatinine in vaginal fluid washings is a useful marker for PROM. It was less expensive and easier to measure than hCG and AFP, and appears to be more accurate than hCG.

Adult↗

PubMed2000

[Utilization of a microsatellite marker to identify rice blast resistance gene in two segregating populations].

The microsatellite (SSLP) marker RM262, which is tightly linked to the blast resistance gene Pi-d(t) in rice, provides means to conduct marker-aided selection in a rice breeding program. The objective of this study was to investigate the ability of this marker to select the blast resistance gene, Pi-d(t), in two crosses for rice blast resistance breeding. The products with amplified the microsatellite primers were polymorphic between the three varieties examined. To examine the power of the identified microsatellite marker in predicting the Pi-d(t) locus, we determined the genotypes of the two F2 populations at the Pi-d(t) locus by performing progeny testing for the disease respones. The results indicated an accuracy of more than 98% in identifying the resistant plants in both populations. Therefore the microsatellite marker can be utilized in marker-assisted selection and breeding for new varieties with blast resistance.

Microsatellite Repeats↗

PubMed2000

Anesthesia of CO2 laser surgery in a patient with Hunter syndrome: case report.

Hunter syndrome (mucopolysaccharidosis, type II; MPS II) is one of a heterogeneous group of recessively inherited mucopolysaccharide storage diseases. Patients with mucopolysaccharidosis show progressive involvement and derangement of many organs, especially upper airway anomalies, which are the major cause of perioperative death. In recent years, a CO2 laser is often applied to upper airway lesions. A 16-year-old patient suffering from Hunter syndrome was scheduled for CO2 laser surgery because of sleep apnea and respiratory stridor. Otolaryngological examination revealed bulging of the bilateral false cord with stenosis of the glottis. We adopted sevoflurane mask induction and high-frequency jet ventilation to overcome the perioperative airway problems. The anesthetic course was uneventful, and the patient was discharged 2 days after the operation.

Adolescent↗

PubMed2000

Immuno-histopathology in the diagnosis of early leprosy.

The present study of 45 early leprosy cases in an endemic area in China indicates: a) Sensitivity of acid-fast bacilli (AFB) detection can be significantly improved by examining approximately 30 serial sections. AFB and/or phenolic glycolipid-I (PGL-I) were mostly detected in the infiltrates in the subepidermal zone, intraneurium, perineurium and around blood vessels. b) PGL-I antigen was positive in 10 clinically suspected, single lesion leprosy cases and AFB positive in 7 patients, AFB and/or PGL-I in nerve in 6 patients. c) Nonspecific chronic inflammation in indeterminate leprosy presented as selective perineural and/or intraneural infiltration with lymphocytes predominating. In the infiltrating mass, fragments of neural tissue were demonstrated with anti-S-100 protein staining. d) Except for 3 cases with unknown numbers of lesions, the present positive immunohistopathological findings are in direct correlation with the number of lesions at first diagnosis, namely: 41.6% (10/24) for single lesion, 66.6% (6/9) for 2 lesions, and 88.8% (8/9) for patients with > or = 3 lesions. e) Typical epithelioid or macrophage granuloma formations were not seen in early leprosy with a single lesion. In testing the immunological inclination of these patients with CD68 or tumor necrosis factor-alpha (TNF-alpha) a positive test is likely to be of prognostic value since TNF-alpha is involved in granuloma formation and nerve damage.

Adolescent↗

PubMed2000

Cardiovascular actions of Radix Stephaniae Tetrandrae: a comparison with its main component, tetrandrine.

A comparison of the cardiovascular actions of the extract of Radix Stephaniae Tetrandrae (RST), the root of a Chinese hero Stephania tetrandra S Moore, in rats with those of tetrandrine (Tet), the best known active component of RST was reviewed. The RST extract inhibits Ca2+ influx into the myocyte and reduces protein release during reperfusion with a Ca2+ containing solution following perfusion with a Ca2+ free solution (Ca2+ paradox), and arrhythmia during reperfusion in the isolated perfused heart. It also reduces the infarct size induced by ischemia/reperfusion in vitro and in vivo. In addition, the RST extract suppresses elevation of arterial blood pressure in DOCA-salt hypertensive rats. It does not further reduce the heart rate and coronary flow significantly during myocardial ischemia. The effects are similar to those of Tet. When compared with the same doses of Tet alone, the RST extract, of which 9% is Tet, produces equally potent effects on infarction, arrhythmias, coronary flow and heart rate, and has a greater inhibitory effect on protein release during Ca2+ paradox. The combination at 1:1 ratio of Tet and fangchinoline (Fan), another main component, which constitutes 6% of the RST extract and has no significant effects on the heart, produces comparable effects on protein release during Ca2+ paradox as Tet alone. The observations suggest that the efficacy of the RST extract cannot be accounted for by Tet alone. Some of the effects may be due to an interaction between the components of the extract. The RST extract also produces similar effects as verapamil, a prototype Ca2+ channel antagonist widely used in the treatment of ischemic heart diseases and hypertension, except that verapamil, at 1 mumol/L, a concentration that produces similar cardiac effects as the RST extract, further reduces heart rate significantly during ischemia. So the RST extract may be a therapeutically better agent in the treatment of ischemic heart diseases and hypertension than Ca2+ channel antagonists because of the absence of the inhibitory effect on heart rate during myocardial ischemia.

Alkaloids↗

PubMed2000

[Extraction and isolation of active component for inhibiting PC3 cell proliferation in vitro from the fruit of Lycium barbarum L].

OBJECTIVE: To extract and isolate the active component inhibiting PC3 cell proliferation in vitro from the fruit of Lycium barbarum. METHOD: The active components of the fruit of L. barbarum were extracted by water, 95% ethanol, 50% ethanol respectively. Then, ethanol extract was extracted with acetone and n-butanol and isolated by SiO2 column and purified by TLC to obtain the active component. The chemical structure of active component was identified by the spectral analysis. MTT assay was used to compare the inhibition activity(IC50) of PC3 cells proliferation of the all extracts. RESULT: According IC50, the most active component among all extracts isolated from the fruit of L. barbarum isscopoletin. CONCLUSION: Scopoletin is the active component of the fruit of L. barbarum for inhibiting PC3 cell proliferation.

Antineoplastic Agents, Phytogenic↗

PubMed2000

[Application of the quantitation with curve-fitting method on chiral separation by high performance liquid chromatography].

We propose for the first time that curve-fitting method should be applied to the quantitation of overlapping peaks in chiral separation by high performance liquid chromatography (HPLC). We have examined the separation of eight isomers of cyfluthrin on a chiral stationary phase (CSP), and found that in comparing with the perpendicular-drop method, the accuracy of quantitation of overlapping peaks with curve-fitting was much higher. Generally, errors in peak area measurement using the perpendicular-drop method become larger as the degree of peak overlap increases. Meanwhile, by using curve-fitting method errors have no apparent difference for different degrees of peak overlap. Generally, for the same chiral compounds, although the resolutions are different with different mobile phase strength, the results of peak areas are the same by using curve-fitting method.

Chromatography, High Pressure Liquid↗

PubMed1999

Characterization of a brain-specific nuclear LIM domain protein (FHL1B) which is an alternatively spliced variant of FHL1.

We have amplified and sequenced a novel, alternatively spliced variant of a human gene coding for the four-and-a-half LIM domain protein 1 (FHL1). This gene is located at chromosome Xq27 and the spliced variant is named FHL1B. The ORF of FHL1B cDNA codes for a LIM-only protein that possesses a zinc finger and three tandem repeats of LIM domains at the N-terminus with an active bipartite nuclear localization signal (NLS) motif and a possible RBP-J binding region at the C-terminus. FHL1B and FHL1 have the same N-terminal three-and-a-half LIM domains but different C-terminal protein sequences, due to the presence of an additional alternative exon 4b in FHL1B causing a frame-shift in the 3'coding region. RT-PCR results revealed that the expression of FHL1 is not restricted in skeletal muscle and heart, but is widely distributed in other tissues, including brain, placenta, lung, liver, kidney and pancreas, albeit as a low abundance transcript. In contrast, FHL1B is specifically expressed in brain. The C-terminal alternative region in FHL1B is sufficient to localize FHL1B in the nucleus of mammalian cell. FHL1B is probably related to neural differentiation and certain fragile X syndrome.

Alternative Splicing↗

PubMed1999

Outcome of a screening program for vancomycin-resistant enterococci in a hospital in Victoria.

OBJECTIVE: To screen for faecal colonisation with vancomycin-resistant enterococci (VRE) among potentially at-risk patients. DESIGN: Infection control screening program. SETTING: Monash Medical Centre (a tertiary care hospital), Melbourne, Victoria, in the seven months from June 1997. PATIENTS: Patients in the Renal, Oncology and Intensive Care (ICU) Units. MAIN OUTCOME MEASURES: Presence of VRE in a rectal swab or faecal specimen taken at admission and at regular intervals during inpatient stay; presence of vancomycin-resistance genes (vanA, vanB and vanC) assessed by polymerase chain reaction (PCR); genetic clonality of isolates assessed by pulsed-field gel electrophoresis (PFGE). RESULTS: 574 patients (356 renal, 134 ICU and 84 oncology) were screened; 12 were colonised with VRE--nine renal inpatients, two having peritoneal dialysis or incentre haemodialysis, and one ICU patient. Nine isolates were Enterococcus faecalis (seven positive for vanB and two negative for all three resistance genes) and three were Enterococcus faecium (all positive for vanB). Eight were high-level gentamicin resistant. PFGE suggested genetic clonality between the index isolate and five other isolates from renal patients. No specific clinical practice was associated with VRE colonisation. Attempts to clear rectal carriage with oral ampicillin/amoxycillin or bacitracin were of limited success. Although antibiotic prescribing in the Renal Unit was generally consistent with defined protocols, use of vancomycin and third-generation cephalosporins has been further restricted. CONCLUSIONS: Renal inpatients in our institution appear most at risk of VRE colonisation (4.6% overall) and therefore of VRE infection. Routine screening, especially of potentially high-risk patients, should be considered in major Australian hospitals.

Adult↗

PubMed1999

Cardioprotection of preconditioning by metabolic inhibition in the rat ventricular myocyte. Involvement of kappa-opioid receptor.

To determine whether opioid receptors (ORs) are involved in the delayed cardioprotection of ischemic preconditioning (IP), the effect of severe metabolic inhibition (MI) with a glucose-free buffer that contained sodium cyanide and 2-deoxy-D-glucose on the viability of isolated rat ventricular myocytes was first determined 20 hours after preconditioning with a sublethal metabolic inhibition (MIP) with a glucose-free buffer that contained 2-deoxy-D-glucose and lactate for 30 minutes in the presence of OR antagonists. With the use of trypan blue exclusion as an index of cell viability, severe MI killed >60% of the cells and the value increased significantly after MIP. In the presence of 5x10(-6) mol/L nor-binaltorphimine (nor-BNI), a selective kappa-OR antagonist, but not 5x10(-6) mol/L CTOP, a selective mu-OR antagonist, or 5x10(-6) mol/L naltrindole, a selective delta-OR antagonist, the cardioprotection of MIP was significantly attenuated. To verify the role of kappa-OR, we studied the effects of severe MI after pretreatment with the kappa-OR agonist U50,488H (UP) for 30 minutes. U50,488H at 3x10(-6) to 1x10(-4) mol/L increased cell viability concentration-dependently with an EC50 of 3.311x10(-6) mol/L. In the presence of 5x10(-6) nor-BNI, the cardioprotection of UP (3x10(-5) mol/L) was blocked. A time course study showed that UP-induced cardioprotection occurred in 2 windows: the first occurred approximately 1 hour later and the other occurred 16 to 20 hours later. Additional studies on cell contraction and intracellular Ca2+ ([Ca2+]i) revealed that both UP and MIP attenuated the inhibitory effects of severe MI on contractility and electrically induced [Ca2+]i transient in single ventricular myocytes. On blockade of protein kinase C, the delayed cardioprotections of UP and MIP were significantly attenuated. In conclusion, the results of the present study have provided evidence that kappa-OR mediates the cardioprotection of MIP, which may involve protein kinase C and [Ca2+]i.

3,4-Dichloro-N-methyl-N-(2-(1-pyrrolidinyl)-cycloh↗