Biomedical subjects

S-J Wang

Publications and source records attributed to S-J Wang.

At least 19 recordsLinked to original sources

PubMed2006

Recurrent primary thunderclap headache and benign CNS angiopathy: spectra of the same disorder?

OBJECTIVES: To investigate the clinical pictures of patients with recurrent thunderclap headaches of unknown etiology and to field-test two relevant International Classification of Headache Disorders, 2nd edition (ICHD-II) criteria, i.e., primary thunderclap headache (Code 4.6) and benign (or reversible) angiopathy of the CNS (Code 6.7.3). METHODS: We prospectively recruited patients presenting with idiopathic recurrent thunderclap headaches from a hospital-based headache clinic. Detailed histories, neurologic examinations, and MRIs and magnetic resonance angiographies (MRAs) were performed in all patients to exclude secondary causes. Patients with cerebral vasoconstriction received serial MRA follow-up. RESULTS: Fifty-six consecutive patients (51 female/5 male, mean age 49.6 +/- 9.8 [range 22 to 76] years) were enrolled. Segmental vasoconstriction (or benign CNS angiopathy) was found in 22 patients (39%). Thunderclap headache recurred in all patients with a median frequency of 0.7 times per day for a median period of 14 days (range 6 to 86 days). The median duration for each single attack was 3 hours. Most patients (84%) reported at least one trigger. Nimodipine effectively aborted further attacks in 83% of the treated patients. Headache attacks subsided within 3 months. Four patients (7%) developed ischemic complications. Patients with and without vasoconstriction based on MRA images were similar regarding demographics and headache profile. Except for the duration criterion, our patients generally mapped well into the proposed ICHD-II criteria. CONCLUSIONS: This study suggests that the two diagnostic entities proposed by the ICHD-II may present different spectra of the same disorder. The distinct headache profile may help physicians quickly recognize this disabling headache disorder with risk of stroke and provide timely treatment.

Adult↗

PubMed2006

Selection of differentially expressed genes in microarray data analysis.

One common objective in microarray experiments is to identify a subset of genes that express differentially among different experimental conditions, for example, between drug treatment and no drug treatment. Often, the goal is to determine the underlying relationship between poor versus good gene signatures for identifying biological functions or predicting specific therapeutic outcomes. Because of the complexity in studying hundreds or thousands of genes in an experiment, selection of a subset of genes to enhance relationships among the underlying biological structures or to improve prediction accuracy of clinical outcomes has been an important issue in microarray data analysis. Selection of differentially expressed genes is a two-step process. The first step is to select an appropriate test statistic and compute the P-value. The genes are ranked according to their P-values as evidence of differential expression. The second step is to assign a significance level, that is, to determine a cutoff threshold from the P-values in accordance with the study objective. In this paper, we consider four commonly used statistics, t-, S- (SAM), U-(Mann-Whitney) and M-statistics to compute the P-values for gene ranking. We consider the family-wise error and false discovery rate false-positive error-controlled procedures to select a limited number of genes, and a receiver-operating characteristic (ROC) approach to select a larger number of genes for assigning the significance level. The ROC approach is particularly useful in genomic/genetic profiling studies. The well-known colon cancer data containing 22 normal and 40 tumor tissues are used to illustrate different gene ranking and significance level assignment methods for applications to genomic/genetic profiling studies. The P-values computed from the t-, U- and M-statistics are very similar. We discuss the common practice that uses the P-value, false-positive error probability, as the primary criterion, and then uses the fold-change as a surrogate measure of biological significance for gene selection. The P-value and the fold-change can be pictorially shown simultaneously in a volcano plot. We also address several issues on gene selection.

Data Interpretation, Statistical↗

PubMed2006

Triterpenoids from the husks of Xanthoceras sorbifolia Bunge.

A new triterpenoid saponin, 3-O-[(3-O-alpha-l-arabinofuranosyl-2-O-beta-d-galactopyranosyl)-beta-d-glucuronopyranosyl]-21,22-di-O-angeloyl-R1-barrigenol (1), together with four known triterpenoids, have been isolated from the husks of Xanthoceras sorbifolia Bunge. Their structures were elucidated based on chemical and spectral analysis. Among them, 1 was found to have activity of inhibiting the proliferation of six human tumour cell lines (IC50 10-40 mug/ml).

Antineoplastic Agents, Phytogenic↗

PubMed2006

Comorbid migraine is associated with a negative impact on quality of life in patients with major depression.

This study investigated the impact of migraine on health-related quality of life (HRQoL) among patients with major depressive disorder (MDD). We prospectively enrolled 151 consecutive psychiatric out-patients meeting DSM-IV criteria for MDD. Migraine and other headache types were diagnosed based on the International Classification of Headache Disorders, 2nd edition (2004). The Short Form-36 (SF-36) was administered as a generic instrument of HRQoL. Among 151 patients with MDD, migraine (N = 73, 48.3%) was very common. Comorbidity of migraine predicted a significantly negative impact on all physical subscales and vitality but not on the other mental subscales of the SF-36 after controlling for depression, age and gender. The presence of migraine should be considered as an important physical symptom in clinic-based MDD samples. Simultaneous management of depression and severe headaches, especially migraine, might improve HRQoL in patients with MDD.

Adolescent↗

PubMed2006

The practice pattern of migraine management among neurologists in Taiwan.

To assess the prevalence of migraine and the attitudes and practice patterns of Taiwanese neurologists regarding migraine management, we mailed the survey questionnaire to all of the actively practicing board-certified neurologists from the membership list of the Taiwan Neurological Association. Of the targeted 531 neurologists, 123 (23.2%) participated in this study. Thirty of the participants (27.6%) reported having migraine. Most neurologists (88.5%) felt that headache was an important part of their practice. Many neurologists (65.0%) used neuroimaging to evaluate patients with severe headache and 44.7% used electroencephalography for headache evaluation. Many participants knew that combination analgesic was a common cause of medication-overuse headache, but did not know that ergotamine, acetaminophen and triptans were possible aetiologies of medication-overuse headache. Our study suggests that awareness of medication-overuse headache and the indications of neuroimaging should be stressed in Taiwan, and headache guidelines should be modified according to local factors.

Analgesics↗

PubMed2006

Is vasospasm requisite for posterior leukoencephalopathy in patients with primary thunderclap headaches?

Primary thunderclap headache (TCH) is sometimes associated with cerebral vasospasm. However, the role of vasospasm in relation to the development of reversible or irreversible posterior leukoencephalopathy among patients with primary TCH has never been fully addressed. This paper includes a report on a 51-year-old woman with primary TCH complicated with posterior leukoencephalopathy and a literature review of 16 further patients with the same illness. Their magnetic resonance or conventional angiographic findings were clearly described. Our review found that all these 17 patients showed evidence of cerebral vasospasm. Eleven (65%) of them developed permanent ischaemic infarctions, almost exclusively located at the watershed zones. We suggest that the presence of vasospasm might be requisite for posterior leukoencephalopathy as well as for permanent infarctions in these patients. Therefore, searching for any clue of vasospasm is mandatory in treatment of patients with primary TCH. Absence of an accompanying vasospasm might predict a good outcome.

Brain↗

PubMed2006

Reduction in hypothalamic 1H-MRS metabolite ratios in patients with cluster headache.

OBJECTIVE: To determine the 1H-MR spectroscopic (MRS) findings in the hypothalamus in patients with episodic cluster headache. METHODS: 47 patients were recruited with episodic cluster headache (35 in cluster period and 12 in remission), 21 normal controls, and 16 patients with chronic migraine. The hypothalamic 1H-MRS metabolite ratio changes in patients with cluster headache were evaluated and compared with results in the normal controls as well as patients with chronic migraine. Seven patients in the cluster period group underwent a follow up hypothalamic MRS study five to six months after remission. RESULTS: In patients with cluster headache, the hypothalamic N-acetylaspartate (NAA)/creatine (Cr) and choline (Cho)/Cr ratios were similar between those in cluster period and in remission. As a group, both NAA/Cr and Cho/Cr levels were significantly lower in patients with cluster headache in comparison with either the control or chronic migraine groups. In those with a follow up MRS study, the levels of metabolite ratios did not differ between the cluster and remission periods. CONCLUSIONS: This study provides evidence of persistent biochemical change of the hypothalamus in patients with episodic cluster headache. Low levels of NAA/Cr and Cho/Cr suggest that cluster headache might be related to both neuronal dysfunction and changes in the membrane lipids in the hypothalamus.

Adult↗

PubMed2005

Characterisation of the welsh onion isolate of Shallot yellow stripe virus from China.

The host range and nucleotide sequence of shallot yellow stripe virus (SYSV) from welsh onion in Shandong province, China is described. Of the plants tested, only shallot and welsh onion became infected but most shallot plants were symptomless. The complete sequence of one isolate (10429 nt) and the 3'-terminal 3540 nts of a second isolate were determined. They had c. 90% nt identity to one another and to published (partial) sequences of SYSV. SYSV was most closely related to onion yellow dwarf virus (OYDV) and resembled it in having a much larger P3 protein than other species in the genus.

Allium↗

PubMed2005

Activation of neuropeptide Y Y1 receptors inhibits glutamate release through reduction of voltage-dependent Ca2+ entry in the rat cerebral cortex nerve terminals: suppression of this inhibitory effect by the protein kinase C-dependent facilitatory pathway.

Neuropeptide Y (NPY) is known to regulate the presynaptic glutamate release and neuronal responses to excitatory neurotransmission. The aim of this study was to investigate the effect of NPY on the release of endogenous glutamate from rat cerebrocortical nerve terminals (synaptosomes). NPY inhibited the Ca2+-dependent glutamate release evoked by 4-aminopyridine, and this inhibitory effect was mediated via NPY Y1 receptors, because it was mimicked by the specific NPY Y1 receptor agonist [Leu31 Pro34] NPY and blocked by the NPY Y1 receptor antagonist GR 231118. The inhibitory action of NPY was not due to it decreasing synaptosomal excitability or directly interfering with the release process at some point subsequent to Ca2+ influx, because NPY did not alter the 4-aminopyridine-evoked depolarization of the synaptosomal plasma membrane potential or ionomycin and hypertonic solution-induced glutamate release. Examination of the effect of NPY on the cytosolic [Ca2+] revealed that the inhibition of glutamate release could be attributed to a reduction in voltage-dependent Ca2+ influx. Consistent with this, the NPY-mediated inhibition of glutamate release was completely abolished in synaptosomes pretreated with N- and P/Q-type Ca2+ channel blocker, omega-conotoxin MVIIC. Moreover, NPY-mediated inhibition of 4-aminopyridine-evoked glutamate release was insensitive to KT 5720 and Ro32-0432 but was suppressed when protein kinase C was stimulated with phorbol ester. Together, these results suggest that NPY acting predominantly on NPY Y1 receptors inhibits glutamate release from rat cerebrocortical synaptosomes, likely by a mechanism involving direct coupling of receptors to N- and P/Q-type Ca2+ channels, and this coupling is subject to regulation by protein kinase C-dependent pathway. This implies that selective ligand for NPY receptors may be of value for treatment of conditions characterized by excessive glutamate release in the cerebral cortex.

4-Aminopyridine↗

PubMed2005

Evolution of migraine diagnoses in adolescents: a 3-year annual survey.

We conducted a 3-year annual questionnaire survey of the International Headache Society (IHS) migraine diagnoses among 2414 adolescents aged 13. For those with migraine without aura (IHS 1.1) at the baseline survey (n = 89), 28% and 24% retained the IHS 1.1 diagnosis at the 2nd and 3rd surveys. Only 0.5% of adolescents had a persistent IHS 1.1 diagnosis for 3 years. Of those with IHS 1.1 or migrainous disorder (IHS 1.7) (n = 449), 43% and 48% retained the IHS 1.1 or IHS 1.7 diagnosis at the 2nd and 3rd surveys. Conversion between IHS 1.1 and IHS 1.7 was common. About 5.6% of the adolescents suffered from IHS 1.1 or IHS 1.7 for all 3 years. Independent predictors for persistent IHS 1.1 or IHS 1.7 diagnosis included frequent headache (>5 days/month) (relative risk (RR) = 1.8) and pulsatile headache (RR = 1.5). The diagnosis of IHS 1.1 in adolescents was quite unstable. Conversion between IHS 1.1 and IHS 1.7 was an important cause. Factoring IHS 1.7 into the spectrum of migraine diagnoses during epidemiological surveys provides a realistic impression of the disease burden in this age group.

Adolescent↗

PubMed2005

Rising prevalence of migraine in Taiwanese adolescents aged 13-15 years.

Whether the prevalence of migraine is increasing is controversial. We conducted annual surveys in 1999-2001 to investigate migraine prevalence among a nationwide sample of 13 426 adolescents aged 13-15 years. Participants from five junior high schools around different regions of Taiwan completed self-administered questionnaires. The diagnosis of migraine was based on the classification criteria proposed by the International Headache Society, 1988. Data for 23 433 person-years were collected and analysed for trends in prevalence and incidence. The 1-year prevalence of migraine increased 42% during 1999-2001 (from 5.2 to 7.4%, P < 0.001). This increasing trend was demonstrated in both sexes, all ages, and all but one studied regions of Taiwan. Of note was the biggest increment of prevalence (79%) among 7th graders (students aged 13 years) through these 3 years. Annual incidence rates did not differ between 1999 and 2000 and 2000 and 2001 (6.1% vs. 5.7%; P = 0.4). One-year persistence rates of migraine diagnosis, surrogates of migraine duration, did not differ between 1999 and 2000 and 2000 and 2001 (34.2% vs. 41.2%; P = 0.1). Our study found that the prevalence of migraine was increasing in our sampled adolescents, which results from an increment starting at age 13 or younger. The prevalence of migraine in Asians might be increasing, although previous studies showed lower prevalence in this region. Children or adolescents may be more vulnerable to the environmental or societal change.

Adolescent↗

PubMed2005

Risk factors associated with migraine or chronic daily headache in out-patients with major depressive disorder.

OBJECTIVE: This study investigated independent comorbidities and factors associated with migraine and chronic daily headache (CDH) in out-patients with major depressive disorder (MDD). METHOD: Consecutive psychiatric out-patients fulfilling the DSM-IV criteria of MDD were enrolled. Headaches were diagnosed based on the criteria proposed by the second edition of the International Classification of the Headache Disorders. Psychiatric comorbidities were checked using the Mini International Neuropsychiatric Interview. Scores of the Hamilton Depression Rating Scale (HAMD) and duration of major depressive episodes (MDE) were evaluated. Multivariate logistic regression was used to decide risk factors. RESULTS: One hundred and fifty-one patients (34 men and 117 women) participated in the study, among which 73 (48.3%) reported a history of migraine and 32 (21.2%) reported CDH during this MDE. Higher HAMD scores, female gender, and chronic depression were independently associated with migraine or CDH. CONCLUSION: For MDD patients with a higher depressive severity and longer duration of MDE, especially female gender, surveillance of migraine and CDH might be indicated.

Adult↗

PubMed2005

Neuropsychiatric profiles in patients with Alzheimer's disease and vascular dementia.

OBJECTIVE: To explore the neuropsychiatric manifestations in patients with Alzheimer's disease (AD) and cortical and subcortical vascular dementia (VaD). METHODS: We investigated consecutive patients with dementia. All the participants received brain computed tomography. The diagnosis of dementia was confirmed by clinical criteria and the imaging findings. Only patients with probable AD, and subcortical and cortical VaD were included. The Mini Mental State Examination (MMSE) was used to evaluate global cognitive function, and the Neuropsychiatric Inventory (NPI) was used to assess neuropsychiatric symptoms. RESULTS: Of the 536 participants with dementia, 320 (59.7%) had AD, 161 (30%) had subcortical VaD, 35 (6.4%) had cortical VaD, and 16 (2.9%) had mixed cortical and subcortical VaD. Cortical VaD patients had the highest mean composite NPI scores in all domains and AD patients had the lowest composite scores in most domains. The mean composite scores of the apathy and sleep disturbance domains in patients with cortical VaD were significantly higher than those in the patients with AD after controlling for years of education and MMSE score (p < 0.01). CONCLUSIONS: There were few differences among the patients with AD, subcortical VaD and cortical VaD. The most consistent differences were the high sleep disturbance scores in those with cortical VaD.

Aged↗

PubMed2004

Nimodipine for treatment of primary thunderclap headache.

Eleven patients with primary thunderclap headache (TCH) were treated with oral nimodipine 30 to 60 mg every 4 hours or IV nimodipine 0.5 to 2 mg/h if the oral regimen failed or images showed cerebral vasospasm. With oral nimodipine, headache did not recur in the nine patients without vasospasm. IV nimodipine was given in two patients with vasospasm, including one who developed ischemic stroke. Nimodipine may be effective for TCH. Vasospasm may warrant IV nimodipine.

Administration, Oral↗

PubMed2004

Mechanisms underlying the riluzole inhibition of glutamate release from rat cerebral cortex nerve terminals (synaptosomes).

We have examined the effect of riluzole, a neuroprotective agent with anticonvulsant properties, on the release of endogenous glutamate from rat cerebrocortical synaptosomes using an on-line enzyme-coupled fluorometric assay. Riluzole inhibited the calcium-dependent release of glutamate that was evoked by exposing cerebrocortical synaptosomes to the potassium channel blocker 4-aminopyridine, and this presynaptic inhibition was concentration-dependent. Riluzole did not alter either 4-aminopyridine-evoked depolarization of the synaptosomal membrane potential or ionomycin-mediated glutamate release, indicating that riluzole-mediated inhibition of glutamate release is not due to a decrease in synaptosomal excitability or a direct effect on the exocytotic machinery. Examination of the effect of riluzole on Ca2+ influx revealed that the diminution of glutamate release could be attributed to a reduction in cytosolic calcium. A possible effect of riluzole on synaptosomal calcium channels was confirmed in experiments where synaptosomes pretreated with P/Q-type calcium channel blocker omega-agatoxin IVA, which abolished the riluzole-mediated inhibition of glutamate release. In addition, pretreatment of synaptosomes with either the Gi/Go protein inhibitor pertussis toxin or the GABAB receptor agonist baclofen, completely prevented the inhibitory effect of riluzole on 4-aminopyridine-evoked glutamate release. It is concluded that riluzole exerts their presynaptic inhibition, likely through a reduction in the calcium influx mediated by P/Q-type calcium channels, and thereby inhibits the release of glutamate from rat cerebrocortical nerve terminals. This release inhibition may involve a pertussis toxin-sensitive G protein signalling pathway. This finding provides further support that presynaptic calcium channel blockade concomitant with inhibition of glutamate release could be an important mechanism underlying the therapeutic actions of this drug.

Animals↗

PubMed2004

Cluster headache in the Taiwanese -- a clinic-based study.

Cluster headache has not been fully investigated in Asians. One hundred and four patients (90M/14F; mean age 39.2 +/- 12.2 years) with cluster headache were recruited from two major headache clinics in Taiwan. They filled out a structured cluster headache questionnaire. All participants were diagnosed to have episodic cluster headache. Mean age of onset was 26.9 years; mean latency of diagnosis was 8.1 years. A trend of decrease in male/female ratio with time was noted. Seventy-three percent were ex- or current smokers (M: 79%, F: 36%). Restlessness was reported by 51% patients. Only 1 patient (1%) reported visual aura. Patients responded well to standard acute and prophylactic treatment. The monthly incidence of cluster period was inversely related to sunshine duration. Compared to Western series, our patients were different in several aspects including the absence of chronic cluster headaches and a low prevalence of restlessness and aura. Racial and geographical factors might contribute to these discrepancies.

Adult↗

PubMed2004

Association between adolescent chronic daily headache and childhood adversity: a community-based study.

The relationship of chronic daily headache (CDH) and childhood adversity is still controversial. We therefore conducted a survey for CDH (> or =15 days/month, average > or = 2 h/day) among all students in three public schools in Taiwan. The Global Family Environment Scale (GFES), which yields a score according to childhood adverse events in the family, was used to compare childhood adversity between cases of CDH and their age- and sex-matched controls. In total, 4645 students were surveyed and 58 with CDH were identified. Significantly lower GFES scores, indicative of worse childhood adversities, were evident in the CDH group (76.7 +/- 19.2), compared with the control group (86.0 +/- 8.9, P = 0.001). Physical abuse (10% vs. 0, P = 0.012) and parental divorce (17% vs. 3%, odds ratio = 5.8, P = 0.015) were more frequent in the CDH group. The results indicate that childhood adversities may contribute to greater risk of the development of CDH in young adolescents.

Adolescent↗

PubMed2004

Headache profiles in patients with a dilatated cyst of the cavum septi pellucidi.

The dilatated cyst of the cavum septi pellucidi (CSP) is rare and may be associated with headaches. We reviewed the computerized database of 54,000 patients' computed tomography or magnetic resonance images and found 22 cases (0.04%) involving a dilatated cyst of the CSP. Sixteen patients had a chief complaint of headache, which was classified as acute episodic headache (type I, n = 7, 43.7%), chronic daily headache (CDH) with acute onset (type II, n = 5, 31.3%), or CDH with insidious onset (type III, n = 4, 25%). Acute Valsalva-induced headaches were common with type I (85%) or II (100%); 70% of these responded to indomethacin. At follow-up, patients with type I headache had the highest remission rate (71%), and type III patients the lowest (0%). Dilatated cysts of the CSP should be considered a cause of acute Valsalva-induced headache or new daily persistent headache, and may respond to indomethacin. A protracted course (> or = 3 months) indicates a worse outcome.

Adolescent↗