Biomedical subjects

Y M Chan

Publications and source records attributed to Y M Chan.

At least 19 recordsLinked to original sources

PubMed2005

Effect of individual psychological intervention in Chinese women with gynecologic malignancy: a randomized controlled trial.

PURPOSE: To evaluate the effectiveness of psychological intervention in the care of cancer patients and to determine whether routine use of individual psychological therapies is indicated. PATIENTS AND METHODS: Patients with newly diagnosed gynecologic malignancies from August 1999 to November 2000 were recruited and randomly assigned to either a control group receiving routine medical care or to an intervention group receiving individual psychotherapy. A set of fixed-choice, self-report questionnaires assessing the patients' psychological status, quality of life, and their perceptions related to the medical consultations was completed at recruitment and then every 3 months for 18 months. Data analysis was performed according to the intention-to-treat principle by fitting the data into a linear mixed-effects model. Multivariable analyses were performed to examine the effects of confounding factors. RESULTS: One hundred fifty-five patients participated in the trial. There were no statistically significant differences between the two groups at baseline. There was a trend toward better quality of life and functional status and also improvement of the symptoms over time for both groups. No differences were found between the groups in the scores measured by any of the instruments at baseline and at any time points after the cancer diagnosis. Psychological intervention had no significant effects on the psychosocial parameters. CONCLUSION: Routine use of psychological therapies as given in our format has no significant effect on the patients' quality of life and psychological status.

Activities of Daily Living↗

PubMed2004

Could precolposcopy information and counseling reduce women's anxiety and improve knowledge and compliance to follow-up?

OBJECTIVE: To investigate the effects of precolposcopy counseling on women's anxiety, knowledge about colposcopy and compliance to follow-up. METHODS: Two hundred and twenty women referred for colposcopy for the first time were recruited. They attended precolposcopy sessions in which written and video information were given and subsequently were randomized to have either further explanation and discussion with an experienced colposcopic nurse (study group) or no further discussion (control group). Each subject completed a Chinese version of the state-anxiety questionnaire (STAI) and a knowledge questionnaire before and immediately after the precolposcopy sessions and also before the colposcopy examination. Women's concern and opinion on the programme were also assessed. Follow-up data was compared with those who did not attend the precolposcopy sessions. RESULTS: Women's knowledge about colposcopy significantly improved after the precolposcopy sessions. The improvement was more significant in the study group than in the control group immediately after the sessions (P = 0.003). The difference between the groups in knowledge scores remained statistically significant before colposcopic examination (P = 0.015) but the difference diminished between these two assessment points. There was no statistically significant difference between the two groups in the anxiety scores at all assessment points. Women who attended the precolposcopy sessions had a significantly higher attendance rates and better compliance to follow-up than those who did not attend the sessions. CONCLUSION: Precolposcopy session with explanation and discussion improves women's knowledge about colposcopy, but has negligible effects on women's anxiety before colposcopy. Provision of written and video information at the precolposcopy sessions can improve compliance to follow-up after colposcopy.

Adult↗

PubMed2004

Spontaneous cerebrospinal fluid otorrhoea via oval window: an obscure cause of recurrent meningitis.

Spontaneous cerebrospinal fluid (CSF) leak via the oval window is uncommon and can result in recurrent bacterial meningitis. Current understanding of spontaneous CSF otorrhoea is reviewed and a diagnostic algorithm is presented. A seven-year-old boy presented with bilateral congenital deafness and recurrent meningitis. High-resolution computed tomography (HRCT) of the temporal bone showed a labyrinthine deformity and communication between the internal auditory canal (IAC) and the cochlea. Subtotal petrosectomy with closure of the external acoustic meatus and eustachian tube was performed. Post-operatively, the child had no further episodes of meningitis. This rare and obscure cause of recurrent childhood meningitis requires a high index of suspicion and the use of diagnostic tools, especially HRCT.

Cerebrospinal Fluid Otorrhea↗

PubMed2004

Head and neck cancer after foreign body ingestion.

INTRODUCTION: Ingestion of a foreign body is a common occurrence in our population. We present 2 cases that illustrate an unusual outcome of an otherwise usual occurrence. CLINICAL PICTURE: Two patients who presented with a history of ingestion of fish bones were worked up. The radiological findings were suspicious of a foreign body and both underwent examination under general anaesthesia. The endoscopic findings were normal. After further evaluation for persistent calcifications with computed tomography, a thyroid malignancy was found in the first patient and tongue cancer in the second patient. TREATMENT: The first patient underwent elective hemithyroidectomy and the second underwent wide excision of the tumour with neck dissection. OUTCOME: Both recovered uneventfully with regular follow-up in the outpatient clinic. CONCLUSION: There should be a high index of suspicion in patients with persistent calcifications.

Calcinosis↗

PubMed2003

The effect of milk supplementation on bone mineral density in postmenopausal Chinese women in Malaysia.

Dietary studies often report low calcium intake amongst post-menopausal Malaysian women and calcium deficiency has been implicated as part of the etiology of age-related bone loss leading to osteoporosis. Therefore, the objective of this study was to examine the effectiveness of high calcium skimmed milk (Anlene Gold, New Zealand Milk, Wellington, New Zealand) to reduce bone loss in Chinese postmenopausal women. Two hundred subjects aged 55-65 years and who were more than 5 years postmenopausal were randomized to a milk group and control group. The milk group consumed 50 g of high calcium skimmed milk powder daily, which contained 1200 mg calcium (taken as two glasses of milk a day). The control group continued with their usual diet. Using repeated measures ANCOVA, the milk supplement was found to significantly reduce the percentage of bone loss at the total body compared to the control group at 24 months (control -1.04%, milk -0.13%; P<0.001). At the lumbar spine, the percentage of bone loss in the control group was significantly higher (-0.90%) when compared to the milk (-0.13%) supplemented group at 24 months (P<0.05). Similarly, milk supplementation reduced the percentage of bone loss at the femoral neck (control -1.21%, milk 0.51%) (P<0.01) and total hip (control -2.17%, milk -0.50%) (P<0.01). The supplemented group did not experience any significant weight gain over the 24 months. The serum 25-hydroxy vitamin D level improved significantly (P<0.01) from 69.1 +/- 16.1 nmol/l at baseline to 86.4 +/- 22.0 nmol/l at 24 months in the milk group. In conclusion, ingestion of high calcium skimmed milk was effective in reducing the rate of bone loss at clinically important lumbar spine and hip sites in postmenopausal Chinese women in Malaysia. Supplementing with milk had additional benefits of improving the serum 25-hydroxy vitamin D status of the subjects.

Aged↗

PubMed2003

Quality of life in women treated with neoadjuvant chemotherapy for advanced ovarian cancer: a prospective longitudinal study.

OBJECTIVE: The purpose was to examine the outcomes of patients with advanced ovarian cancer treated with neoadjuvant chemotherapy, with a special emphasis on the patients' quality of life (QOL). METHODS: Seventeen patients with advanced ovarian cancer were treated with neoadjuvant chemotherapy based on the extent of disease on computer tomography. All patients received combined platinum/paclitaxel chemotherapy. Debulking surgery was performed after three cycles or six cycles of chemotherapy, depending on the response to the chemotherapy. Patients' QOL was studied over time using European Organization for Research and Treatment of Cancer Quality of Life Questionnaire C30 and was then compared with that of patients treated with conventional treatment in the previous cohort. RESULTS: The response rate to chemotherapy assessed at three cycles was 82.4%. The rate of optimum debulking to residual disease less than 2 cm after chemotherapy was 76.9%, and 38.5% had no gross residual disease after surgery. The median overall survival was 22.9 months. The median disease-free interval was 13.3 months. The overall QOL improved after chemotherapy and this continued to improve up to 12 months. The other functional scales also showed improvements over time, apart from the initial transient deterioration in the role functioning and cognitive functioning at 3 months after chemotherapy. Patients treated with neoadjuvant chemotherapy seem to have better but statistically insignificant difference in QOL parameters than patients treated conventionally. CONCLUSION: Neoadjuvant chemotherapy is an alternative treatment for patients with advanced ovarian cancer in whom the chance of optimal cytoreduction is low. The patients' overall quality of life and functional status improve after neoadjuvant chemotherapy.

Antineoplastic Combined Chemotherapy Protocols↗

PubMed2003

A retrospective review on atypical glandular cells of undetermined significance (AGUS) using the Bethesda 2001 classification.

OBJECTIVE: The Bethesda system for reporting cervicovaginal cytologic diagnoses was recently revised in 2001. Pathologists are required to report not only whether the smear favors neoplastic changes, but also the origin of the abnormal cells. In this study, archival smears were reviewed to evaluate the usefulness of the new classification. METHODS: Smears having atypical glandular cells taken between January 1995 and December 1997 were reviewed and subclassified according to the revised Bethesda classification. Case records were then reviewed and cases with discrepancies between the cytological evaluation and corresponding final histological diagnoses were further reviewed. RESULTS: There were 138 smears reviewed. The mean age of the patients was 47 (range, 18 to 78). Thirty-four smears favored neoplasia and 104 favored "NOS" ("not otherwise specified"). Sixty smears favored endocervical origin and 78 endometrial origin. Forty-three patients (31%) had significant pathologies, including 12 (8.7%) patients with high-grade CIN, 2 (1.4%) with low-grade CIN, 5 (3.6%) with HPV infection, 7 (5.1%) with carcinoma of the corpus, 1 (0.7%) with cervical adenocarcinoma in situ, 4 (2.9%) with adenocarcinoma of the cervix, 3 (2.2%) with endometrial hyperplasia, and 5 (3.6%) with carcinoma of the ovary. Two (1.4%) patients had double primary female genital malignancies and 2 patients (1.4%) had extragenital malignancies. Significant correlation was found between smears "favor neoplasia" and a final diagnosis with significant pathology (chi(2) test, P < 0.05). Significant association was found between AGC favored endocervical origin and a final diagnosis with cervical diseases (chi(2) test, P < 0.05). Four of the 43 patients who had significant pathologies had lesions found during their subsequent visits and all of them had cervical smears classified as AGC "favor neoplasia". CONCLUSION: AGC found on cervical smears are an indication for early and intensive investigation.

Adenocarcinoma↗

PubMed2003

Symptoms, coping strategies, and timing of presentations in patients with newly diagnosed ovarian cancer.

OBJECTIVE: The purpose was to explore whether health education on symptoms of ovarian cancer would aid in early detection, by examining the relationship between symptoms, coping strategies, and timing of presentation in patients with newly diagnosed ovarian cancer. METHODS: Eighty women were included. A questionnaire consisting of a series of open questions was designed to collect information on the sequence of events from the onset of symptoms to the diagnosis of ovarian cancer. The Coping Response Inventory (CRI) was used to assess the coping strategies. RESULTS: A majority (90.0%) of women with ovarian cancer did have symptoms before the diagnosis. Abdominal pain or discomfort, abdominal distension, a palpable abdominal mass, menstrual, bowel, or urinary symptoms were the commonly reported symptoms. Eight (10.0%) patients were totally asymptomatic prior to the cancer diagnosis. The presence of bowel symptoms was significantly associated with late stage disease. Most of the patients sought medical advice within 2 weeks from the onset of symptoms. There was no association between the presence of any particular symptom(s) and the timing of presentation. There was also no correlation between the coping strategies and stage of disease and timing of presentation. On average, patients with early stage disease saw one more doctor compared to patients with late stage disease before the affirmative diagnosis of ovarian cancer. CONCLUSION: Most patients presented early after the onset of symptoms. Health education in this regard may not be useful for early diagnosis of ovarian cancer.

Adaptation, Psychological↗

PubMed2003

The use of music to reduce anxiety for patients undergoing colposcopy: a randomized trial.

OBJECTIVE: The goal of this work was to investigate the impact of music on women's anxiety and perceived pain during colposcopy examination. METHODS: This was a prospective randomized study. Two hundred and twenty women referred for colposcopy for the first time were recruited. They were randomized to either the music or no-music group. Before colposcopy examination, each subject completed a Chinese version of the state anxiety questionnaire (STAI) and assessed the anticipated pain for colposcopy with a visual analog scale (VAS). Slow-rhythm music was played during colposcopy examination in the music group. Subjects in the no-music group were examined in the same setting without music. After colposcopy, each subject completed the STAI form again and assessed their pain during examination by the VAS. RESULTS: Women in the music group experienced significantly less pain (mean VAS 3.32 [95% CI 2.86-3.78] vs 5.03 [4.54-5.52], P<0.001) and lower anxiety (mean STAI 39.36 [95% CI 37.33-41.39] vs 44.16 [41.82-46.49], P = 0.002) during colposcopy examination than women in the no-music group. On linear regression analysis, the factors significantly affecting anxiety during colposcopy were anxiety score at enrollment, pain score during colposcopy, and whether or not the women had listened to music during the colposcopy examination. The factors significantly affecting the pain scores were whether the women had listened to music during the procedure and the final anxiety scores. CONCLUSIONS: Music is a simple, inexpensive, and easily used strategy to minimize anxiety and pain during colposcopy examination.

Adult↗

PubMed2002

Monitoring of serum squamous cell carcinoma antigen levels in invasive cervical cancer: is it cost-effective?

OBJECTIVE: The aim of this study was to assess the cost-effectiveness of serial squamous cell carcinoma antigen (SCC) monitoring in the clinical setting. METHODS: All patients with squamous cell carcinoma of the cervix and SCC measurement from 1994 to 1999 were reviewed. The cost of the investigations, including blood tests, X rays, and computer tomography; and clinic visits were adjusted to 2001 dollars for all cases over the 6-year study period. The effectiveness measure was the number of cases detected by SCC monitoring before the onset of clinical symptoms or abnormal physical examination findings. Altered clinical management due to early detection was considered successful. RESULTS: Two thousand eight hundred fifty-one SCC antigen assays were performed from 384 patients. An elevated pretreatment SCC level was associated with poorer cumulative survival over time (P < 0.05). Fifty-five patients had recurrences, with 10 local and 45 distant recurrences. SCC levels were elevated in 47 patients (85%). The median lead time was 7.8 months. The cost of finding 1 recurrence was US$4750. SCC monitoring does not alter clinical management and has no advantage over clinical examination in detecting local recurrence. Most of the recurrent diseases were detected too late for curative treatment. Only 1 patient, in whom the diagnosis could have been made by clinical examination without SCC monitoring, may have potentially benefited from exenteration. CONCLUSION: Posttreatment SCC monitoring is not cost-effective in the absence of curative treatment for distant spread of disease.

Antigens, Neoplasm↗

PubMed2002

Dietary calcium intake in postmenopausal Malaysian women: comparison between the food frequency questionnaire and three-day food records.

The objective of this study was to compare the dietary calcium intakes assessed by a quantitative food frequency questionnaire (FFQ) and the three-day food record method in 230 Chinese postmenopausal women aged 50-65 years in Kuala Lumpur. The results showed that the mean calcium intake from the dietary records was 447+/-168 mg/day and 499+/-211 mg/day from the FFQ. The mean difference in intake by the two methods was 51.3 mg (95% CI = -30.8-77.9; SD = 181.2, P>0.05), which did not differ significantly from zero. Pearson's correlation coefficient of 0.56 was obtained between the two methods. Ninety-five percent of the individuals classified by food records fell into the same or within-one-quartile category when classified by FFQ. Forty-eight percent were classified into the same quartile by both methods. No subjects were grossly misclassified by the FFQ. The FFQ correctly identified subjects with calcium intakes below the Malaysian recommended daily allowance (450 mg/day) with 60% specificity and with 92% specificity for women consuming less than 800 mg calcium/day. In conclusion, the FFQ developed was a useful, rapid clinical tool for assessing calcium intake and identifying postmenopausal Chinese women with low calcium intakes in Malaysia.

Adult↗

PubMed2002

Cellular signaling mechanisms underlying pharmacological action of Bak Foong Pills on gastrointestinal secretion.

Bak Foong Pills (BFP, also known as Bai Feng Wan) is an over-the-counter traditional Chinese medicine that has long been used for treating gynecological disorders and improving overall body functions, including gastrointestinal (GI) function. However, the cellular signaling mechanism underlying BFP action, especially on the GI tract, has not been elucidated. In the present study, the human colonic epithelia cell line T(84) was used as a model to investigate the effect of BFP ethanol extract on ion transport in conjunction with the short-circuit current (I(SC)) technique. The results showed that the apical addition of BFP extract produced a concentration-dependent (10-1,000 microg/ml, EC(50) = 120 microg/ml) increase in I(SC). The maximal response was observed at 500 microg/ml with an increase in I(SC) of 24.4 +/- 2.3 microA/cm(2) and apical conductance. The BFP-induced I(SC) was not observed when extracellular Cl(-) was replaced or when treated with Bumetanide (100 microM), an inhibitor of the Na(+)-K(+)-2Cl(-) cotransporter. The BFP-induced I(SC) was insensitive to the Na(+) channel blocker, amiloride, but partially inhibited by the Cl(-) channel blocker, DIDS (100 microM), and completely blocked by DPC (2 mM) or glibenclamide (1 mM) with a significant reduction in the apical conductance. The BFP-induced I(SC) could be mimicked by forskolin (10 microM), but inhibited by a pretreatment of the cells with adenylate cyclase inhibitor, MDL-12330A (10 microM). Pretreatment with EGTA (5 mM) and thapsigargin (10 microM) decreased the BFP-induced I(SC) by 10%. These results demonstrated that BFP ethanol extract exerted a stimulatory effect on gastrointestinal Cl(-) secretion by predominantly activating adenylate cyclase and apical cAMP-dependent Cl(-) channels, with minor contributions from calcium-dependent Cl(-) channels. The effect of BFP may be explored to treat GI disorders such as constipation.

Adenylyl Cyclases↗

PubMed2001

Caspase inhibitors promote the survival of avulsed spinal motoneurons in neonatal rats.

Following ventral root avulsion in neonatal animals, the degeneration of spinal motoneurons occurs by an apoptotic-like morphological pathway. In adult animals, however, the mechanism of degeneration of injured motoneurons is still controversial. Because caspases are important mediators of apoptosis, we have investigated the effects of the caspase inhibitors, benzyloxycarbonyl-Asp(OMe)fluoromethylketone (Boc-D-FMK), and N-acetyl-Asp-Glu-Val-Asp aldehyde (Ac-DEVD-CHO) on the survival of neonatal and adult spinal motoneurons after root avulsion of the C7 spinal cord. In the control neonatal animals, virtually all motoneurons had degenerated by 7 days following root avulsion. Treatment with either 0.5 microg Boc-D-FMK or 1 microg Ac-DEVD-CHO enhanced the survival of motoneurons to 80% and 85% for up to 2 weeks post-injury. By 21 days post-injury, 70% of avulsed motoneurons were still present after Boc-D-FMK treatment, whereas all avulsed motoneurons died after treatment with Ac-DEVD-CHO. In adult animals, neither inhibitor was neuroprotective for motoneurons following root avulsion. In summary, the inhibition of caspases effectively rescued avulsed neonatal motoneurons which are died by apoptotic pathway. By contrast, because caspase inhibitors failed to rescue injured motoneurons in adult animals, their death may occur by a non-apoptotic pathway.

Age Factors↗

PubMed2001

Psychosocial adjustment in gynecologic cancer survivors: a longitudinal study on risk factors for maladjustment.

OBJECTIVE: The objective was to describe the change in psychosocial state over time and to identify risk factors for maladjustment in gynecologic cancer survivors. Awareness of these issues is important for planning supportive care services for cancer patients. METHODS: A longitudinal prospective study of patients with newly diagnosed gynecologic cancer using individual patients as their own control was performed. Patients were interviewed after confirmation of the diagnosis and were reassessed at 6 and 18 months after completion of treatment and with no evidence of recurrent disease. Psychological adjustment was measured by self-rating on self-esteem, outlook on life, self-role, and femininity. Neuroticism and anxiety were assessed using a neuroticism score and the Hamilton Anxiety Scale. Depressive symptoms were questioned directly. Social adjustment was assessed by changes in working capacity or work status, leisure activity, marital relationship, and sexual activity. RESULTS: Seventy-four women participated. Adjustment problems did not occur in the majority of patients. Psychosocial adjustment was different for patients receiving different types of treatments. Improvement in feminism (P = 0.050) and neuroticism (P = 0.010) was observed for patients receiving chemotherapy and deterioration was observed in patients treated with surgery. Deterioration in neuroticism was associated with lower education level (P = 0.032). With religious belief, there was better family support and more significant improvement in social activity (P = 0.038). CONCLUSION: Most patients adapted well. Patients at risk for psychosocial maladjustment include those who are treated surgically, less educated, and without religious belief.

Adolescent↗

PubMed2001

A longitudinal study on quality of life after gynecologic cancer treatment.

OBJECTIVE: The objective was to describe the pattern of quality of life (QOL) over time and to assess the impact of age, symptoms, disease parameters, and treatment on the overall QOL. METHODS: A longitudinal study on patients with newly diagnosed gynecologic cancer using individual patients as their own control was performed. The 33-item EORTC QLQ-C30(+3) was used as the QOL measure. Patients were assessed before treatment, after completion of treatment, and at 6, 12, and 24 months. Spearman's correlation analyses were performed. A mixed effect model was fitted to the data. Bonferroni pairwise comparisons were used to analyze the different variables. RESULTS: One hundred forty-four women completed the study. Overall QOL improved after the completion of treatment but remained the same throughout the 2 years after treatment. The individual patient's QOL before treatment was insignificant while the impact of treatment on the individual patient was significant in determining QOL after treatment. There was a strong correlation for all time points in most factors, indicating that the global health status, functional scales, and symptom scales exhibit a dependent change over time. Relief in symptoms was associated with improvements in functional scales. The scores on overall QOL were lower for younger patients and for patients treated with chemotherapy than for patients treated with surgery. CONCLUSIONS: Strategies for supportive care need to focus on symptom management. Psychosocial interventions, to be effective, should include all patients and should aim to reduce the impact of treatment on the individual patient.

Adult↗

PubMed2001

The use of misoprostol prior to hysteroscopy in postmenopausal women.

BACKGROUND: This study examined whether oral misoprostol exerted a cervical priming effect in postmenopausal women prior to hysteroscopy. METHOD: Thirty-seven patients were randomized to receive either oral misoprostol (400 microg) or placebo (vitamin B(6)) 12 h prior to hysteroscopy. The resistance of the cervix to dilatation was objectively assessed by a cervical tonometer. RESULTS: The mean baseline cervical dilatation (4.2 mm in misoprostol group versus 4.4 mm in placebo group) was similar between the two groups. The mean cumulative force measured (27.7 N in misoprostol group versus 21.8 N in placebo group) was also comparable. None of the patients suffered from any significant side-effects. CONCLUSIONS: These data showed that there were no significant benefits from giving misoprostol pre-operatively in postmenopausal women, and it was concluded that oral misoprostol had no significant cervical priming effect in postmenopausal women.

Cervix Uteri↗

PubMed2001

Vaginal misoprostol as medical treatment for first trimester spontaneous miscarriage.

BACKGROUND: Misoprostol is effective for cervical priming prior to suction evacuation in first trimester pregnancy termination. This is the first randomized study to compare vaginal misoprostol versus expectant treatment in women presenting with spontaneous miscarriage. METHODS: Sixty women presenting with spontaneous miscarriage were recruited to the study at the Queen Mary Hospital between 1998 and 1999. They were randomized to group 1: misoprostol; and group 2: expectant management. Women in the misoprostol group received vaginal misoprostol 400 microg on days 1, 3 and 5. The expectant group was followed up according to the same schedule. Suction evacuation was performed if there was excessive bleeding or abdominal pain; or if a gestational sac was detected by transvaginal scan on day 15. RESULTS: Fifty-nine women completed the trial. Those who did not require suction evacuation up to the time of return of normal menstruation were considered to be successful. The incidence of side-effects was comparable between the two groups. Three women in the expectant group and one in the misoprostol group underwent emergency suction evacuation because of excessive bleeding. The mean duration of vaginal bleeding was similar for both groups (14.6 days in the misoprostol group versus 15.0 days in the expectant group). The successful rate in the misoprostol group was significantly higher than that of the expectant group (83.3 versus 48.3%, P < 0.05). CONCLUSION: We recommend repeated vaginal misoprostol 400 microg given on days 1, 3 and 5 as a treatment option for women with first trimester spontaneous miscarriage.

Abortion, Spontaneous↗

PubMed2001

A novel 1:1 complex of potassium mikanin-3-O-sulfate with methanol.

Mikanin-3-O-sulfate (1), in the form of its potassium salt, together with mikanin (2) and alpinetin (3) were isolated from Mikania micrantha. The crystal structures of K(1) x CH3OH, 2 and 3 x H2O were established by X-ray crystallography. The potassium ions in K(1) x CHO3H are bridged by O5, O7 and O8 to form a chain of face-sharing KO8 coordination polyhedra, from which the aglycon units are outstretched to form a polymeric molecular column. Adjacent molecular columns are linked by pi-pi stacking between parallel, intercalating aglycon units to form layers matching the (101) family of planes, which are further interconnected into a three-dimensional supramolecular assembly. Sulfation at 3-OH induced better co-planarity and conjugation of the rings.

Asteraceae↗