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T Y Huang

Publications and source records attributed to T Y Huang.

At least 19 recordsLinked to original sources
PubMed2005

Aging is associated with an increase in dye coupling and in gap junction number in satellite glial cells of murine dorsal root ganglia.

Glial cells in both central and peripheral nervous systems are connected by gap junctions, which allow electrical and metabolic coupling between them. In spite of the great current interest in aging of the nervous system, the effect of aging on glial cell coupling received little attention. We examined coupling between satellite glial cells in murine dorsal root ganglia using the dye coupling technique and electron microscopy. We studied mice at ages of postnatal 90-730 days. Dye coupling incidence between satellite glial cells associated with a single neuron increased from 24.2% at postnatal day 90 to 50.5% at postnatal day 730. Dye coupling between satellite glial cells that are in contact with two or more neurons increased from 2.7% at postnatal day 90 to 18.6% at postnatal day 730 (P<0.05). Examination of the ganglia with the electron microscope showed that the number of gap junctions per 100 microm2 of surface area of satellite glial cells increased from 0.22 at postnatal day 90 to 1.56 at postnatal day 730 (P<0.01). The mean length of individual gap junctions did not change with age. These results provide strong evidence for an increase of functional coupling between satellite glial cells during life. This increase is apparently due to an increase in the total area of the system of gap junctions connecting these cells.

Aging↗
PubMed2004

Comparison of the efficacy and tolerability of telmisartan 40 mg vs. enalapril 10 mg in the treatment of mild-to-moderate hypertension: a multicentre, double-blind study in Taiwanese patients.

The purpose of this randomised, double-blind, double-dummy, parallel-group study was to evaluate the efficacy and tolerability of telmisartan 40 mg once daily vs. enalapril 10 mg once daily in 147 Taiwanese patients with mild-to-moderate essential hypertension (diastolic blood pressure [DBP] 90-109 mmHg). After 6 weeks' treatment, telmisartan produced a significantly greater reduction from baseline in the primary endpoint of trough seated DBP compared with enalapril 10 mg (11.7 vs. 8.7 mmHg, respectively; p = 0.02). Numerically greater reductions compared with baseline in seated systolic blood pressure (SBP), standing DBP, and standing SBP were achieved with telmisartan compared with enalapril. Also, numerically greater proportions of patients achieved blood pressure control (DBP/systolic blood pressure [SBP] <90/140 mmHg) and responded to treatment (reduction from baseline in trough seated DBP > or = 10 mmHg and/or post-treatment DBP <90 mmHg; reduction from baseline in trough seated SBP > or = 10 mmHg and/or post-treatment SBP <140 mmHg) with telmisartan 40 mg compared with enalapril 10 mg. Although both treatments were well tolerated, the incidence of cough was markedly lower with telmisartan 40 mg (8.5%) than with enalapril 10 mg (18.4%) in this population of Taiwanese hypertensive patients.

Adult↗
PubMed2003

Satellite cell reactions to axon injury of sensory ganglion neurons: increase in number of gap junctions and formation of bridges connecting previously separate perineuronal sheaths.

This study investigated satellite cell changes in mouse L4 and L5 spinal ganglia 14 days after unilateral transection of sciatic and saphenous nerves. The ganglia were studied under the electron microscope in single and serial sections, and by dye injection. Satellite cell responses to axon injury of the neurons with which they are associated included the formation of bridges connecting previously separate perineuronal sheaths and the formation of new gap junctions, resulting in more extensive cell coupling. Some possible consequences of these satellite cell reactions are briefly discussed.

Animals↗
PubMed2002

Glial cell plasticity in sensory ganglia induced by nerve damage.

Numerous studies have been done on the effect of nerve injury on neurons of sensory ganglia but little is known about the contribution of satellite glial cells (SCs) in these ganglia to post-injury events. We investigated cell-to-cell coupling and ultrastructure of SCs in mouse dorsal root ganglia after nerve injury (axotomy). Under control conditions SCs were mutually coupled, but mainly to other SCs around a given neuron. After axotomy SCs became extensively coupled to SCs that enveloped other neurons, apparently by gap junctions. Serial section electron microscopy showed that after axotomy SC sheaths enveloping neighboring neurons formed connections with each other. Such connections were absent in control ganglia. The number of gap junctions between SCs increased 6.5-fold after axotomy. We propose that axotomy induces growth of perineuronal SC sheaths, leading to contacts between SCs enveloping adjacent neurons and to formation of new gap junctions between SCs. These changes may be an important mode of glial plasticity and can contribute to neuropathic pain.

Animals↗
PubMed2001

Endothelial [Ca2+]i is an integrating signal for the vascular tone in rat aortae.

BACKGROUND: Although various endothelium-dependent relaxing factors (endothelial autacoids) are released upon the elevation of endothelial cytosolic free Ca2+ concentration (EC [Ca2+]i), the quantitative relationship between EC [Ca2+]i and vascular tone remains to be established. Moreover, whether the basal release of endothelial autacoids is modulated by basal EC [Ca2+]i is still unclear. We assessed these issues by using a novel method that allows simultaneous recording of EC [Ca2+]i and vascular displacement in dissected rat aortic segments. RESULTS: Receptor-dependent (acetylcholine) or independent (ionomycin) agonists caused immediate EC [Ca2+]i elevation followed by vasorelaxation in preparations pre-contracted with phenylephrine. Low doses of agonists induced small EC [Ca2+]i elevations (about 100 nmol/L) and concomitant half-maximal vasorelaxation. At high doses, agonists elevated EC [Ca2+]i to micromol/L range with little additional vasodilatation. When EC [Ca2+]i was plotted against the vasorelaxation, the curves were almost identical for both acetylcholine and ionomycin treatments, in the presence or absence of various endothelial autacoid inhibitors. Calcium-free solution reduced basal EC [Ca2+]i and induced a drastic vasoconstriction. Endothelial autacoid inhibitors reduced EC [Ca2+]i changes and abolished both agonist-induced vasodilatation and calcium-free solution-induced vessel contraction. When the EC [Ca2+]i was completely chelated by 40 micromol/L BAPTA, the acetylcholine-evoked vasorelaxation could be abolished as well. However, when the EC [Ca2+]i was partially chelated by 20 micromol/L BAPTA, the acetylcholine-evoked vasorelaxation was almost unaffected. CONCLUSIONS: These results indicate that vascular tone is modulated by subtle changes of EC [Ca2+]i level, which seems to serve as an integrating signal in both basal and stimulated states.

Animals↗
PubMed2001

Preoperative and postoperative seizures in patients with astrocytic tumours: analysis of incidence and influencing factors.

To evaluate the incidence and influencing factors related to preoperative and postoperative seizures, a retrospective analysis was performed in 190 patients with astrocytic tumours. Preoperative seizures occurred in 50 (26%) patients and 27 (54%) of the m had recurrent seizures. Late-onset seizures developed after craniotomy in 11 (8%) of 140 patients. Seizures at presentation were significantly correlated with age at diagnosis (P=0.0204) and pathological grade of tumour (P=0.0040). The patients aged less than 40 years had a high risk of seizures at presentation (odds ratio=3.076, P=0.0134). Postoperative seizures were significantly associated with the presence of preoperative seizures (P<0.0001), type or duration of preoperative seizures (P<0.0001, P<0.0001, respectively) and serum level of anticonvulsant drug (P=0.0068). However, only the presence of preoperative seizures had a potential for prediction of postoperative seizures when evaluated by logistic regression model (odds ratio=20.859, P=0.0001). Fifty-nine percent of patients with recurrent seizures and 64% of patients with late-onset seizures had seizures which occurred within 6 months after craniotomy. Despite therapeutic anticonvulsant levels, most postoperative seizures were associated with tumour recurrence or haemorrhage. Postoperative seizures commonly occurred relatively soon after craniotomy and prophylactic anticonvulsants should be given. In patients with postoperative seizures, particularly in the presence of therapeutic anticonvulsant level, brain computed tomography should be performed to exclude tumour recurrence or haemorrhage.

Adolescent↗
PubMed2001

Effect of honey and sugars on the metabolism and disposition of naringin in rabbits.

To investigate the effect of honey and sugars on the metabolism and disposition of naringin, rabbits were administered naringin alone and naringin with honey or its component sugars - fructose, glucose and sucrose in crossover designs. An HPLC method was developed to determine naringenin in serum after enzymatic hydrolysis. Our results indicate that honey, fructose and sucrose significantly reduced AUC(0-t) of naringenin by 41 %, 61 % and 45 %, respectively. In vitro studies using a rabbit feces suspension to incubate naringin without or with honey or the respective sugars were employed to investigate the mechanism of this interaction. The results indicated that honey and its component sugars did not affect the rate and extent of naringin hydrolysis, whereas the degradation of naringenin was significantly enhanced in the presence of honey and fructose. It could be concluded that concomitant intake of honey, fructose and sucrose resulted in the reduction of naringin absorption which could be attributable in part to the enhanced preabsorption degradation of absorbable naringenin in the large intestine.

Animals↗
PubMed2001

[Investigation on genotype constitution of different Plasmodium vivax isolates and its geographical distribution in China].

OBJECTIVE: To investigate the population constitution and geographical distribution of Plasmodium vivax in China using molecular technique. METHODS: Blood-spot filter paper samples with related epidemiological data were collected from vivax malaria patients living in malarious area of 10 provinces (autonomous region) in China. Semi-nested- or nested-allelic-specific PCR genotyping method was used to identify CSP genotypes, families and types of Plasmodium vivax of each isolate from these patients. RESULTS: Of 384 field isolates of Plasmodium vivax, 258 temperate zone family strains were identified, including 14 allelic variant genotypes spreading among 10 sampling provinces; allelic variants sized less than 731 bp were only seen in 5 provinces in southern China; 79 tropical zone family strains including 5 genotypes were also distributed in 5 provinces of southern China south to 25 degrees N. lat; and 14 PV Type-2 strains including 2 genotypes were found in some areas of Hainan and Yunnan Provinces. In addition, 33 isolates from genotype-mixed infections were revealed. CONCLUSION: At present, area north to 25 degrees N. lat. of the country is the sole area prevalent for Plasmodium vivax family strains of temperate zone; there is overlapping distribution of P. v. of temperate zone family and tropical zone family of this parasite in the southern China south to 25 degrees N. lat; where the most complex isolate constitution is in Yunnan and Hainan Provinces, and PV Type-2 strains have been found in some areas of the two provinces. Besides, there were 2 groups of genotype with distinct geographic distribution feature within the temperate zone family.

Animals↗
PubMed2000

Relation of Helicobacter pylori infection and angiographically demonstrated coronary artery disease.

Conventional coronary risk factors explain only part of the variation in the incidence of cases of coronary heart disease. Recently H. pylori genomic material has been demonstrated in the coronary arteries of myocardial infarct. In searching for additional coronary risk factors, the potential role of H. pylori infection deserves to be investigated. To clarify if H. pylori infection is associated with an increased risk of coronary heart disease, a series of patients admitted to the Cardiac Catheterization Laboratory for coronary angiography were recruited prospectively. Cases (N = 165) were defined as those who had at least one coronary artery lesion occupying at least 50% of the luminal diameter on coronary angiography. Patients who had normal coronary angiography were selected as controls (N = 127). Demographic data, cardiovascular risk factors, and socioeconomic status were measured in both of the patients and controls. Stored serum specimens from both groups were tested for the presence of serum IgG antibody to H. pylori using enzyme-linked immunosorbent assay; 69.1% of the cases and 77.2% of the controls were seropositive for H. pylori (odds ratio 0.66, 95% CI 0.38-1.16, P = 0.12). After adjustment for age, gender, cardiovascular risk factors, and socioeconomic class, this remained nonsignificant (odds ratio 0.59, 95% CI 0.32-1.09, P = 0.09). H. pylori seropositivity was not associated with several coronary risk factors in either cases or controls. The proportion of H. pylori-positive patients was higher among the cases with triple vessel disease (77.5%) than those with double vessel disease (67.3%) and single vessel disease (65.7%); however, the differences were not statistically significant (odds ratio 0.57, 95% CI 0.23-1.4, P = 0.19). In this study no increase was found in H. pylori seropositivity in subjects with coronary artery disease. This minor association suggests that previous H. pylori infection, reflecting the early childhood environment, may not be important in determining the risk of coronary heart disease.

Aged↗
PubMed2000

Late diagnosis of Kawasaki disease is associated with haptoglobin phenotype.

BACKGROUND: Kawasaki disease (KD) is an acute febrile illness characterized by multiple clinical and biochemical features of inflammation and the most common complications of coronary artery abnormality (CAA). Haptoglobin (Hp) is an acute-phase protein whose phenotype is known to be involved in coronary artery diseases. In this paper, we report the investigation of the association of Hp phenotype with the formation of CAA in KD. PATIENTS AND METHODS: Forty-seven consecutive patients with clinically diagnosed KD were admitted. Sera were taken before therapy of intravenous immunoglobulins (IVIG) plus aspirin, and levels of serum proteins were measured by a rate immunonephelometer. The echocardiographic criteria for coronary artery abnormality were evaluated during acute or subacute stages. Hp phenotyping was performed by Western immunoblotting. RESULTS: Duration of fever at diagnosis of KD was significantly different between patients with Hp 2-2 (6.4 +/- 1.2 days, n = 25) and with Hp1 allele (Hp 2-1 plus Hp 1-1; 8.8 +/- 3.5 days, n = 22). In contrast, serum levels of Hp between KD patients with Hp2-2 and with Hp1 allele (297 +/- 121 mg dL-1 vs. 330 +/- 101 mg dL-1, respectively) was not significantly different. On the other hand, no patients with Hp 2-2 (0/25) were recognized as having KD in subacute stage. However, 5 out of 20 patients with Hp 2-1 were recognized in subacute stage, and their incidence of CAA was 80.0% (4/5). CONCLUSIONS: Patients with Hp 2-1 have patterns of delayed or incomplete presentation of clinical symptoms. Therefore, the late diagnosis of KD is associated with haptoglobin phenotype.

Acute Disease↗
PubMed2000

Heterogeneity of [Ca(2+)](i) signaling in intact rat aortic endothelium.

Most existing knowledge about [Ca(2+)](i) signaling in vascular endothelium has been based on studies using endothelial cells cultured in vitro. To examine how endothelial cells behave in situ, we have developed a method to monitor single-cell [Ca(2+)](i) from Fura-2-loaded rat aortic segments. Fluorescence ratio images from large numbers of endothelial cells were acquired by using a flow chamber mounted on a dual-wavelength fluorescence microscope. Our results showed that either acetylcholine or histamine reversibly activated the vascular endothelium by eliciting M(3) or H(1) receptor-mediated [Ca(2+)](i) increases, respectively. The acetylcholine-evoked endothelial [Ca(2+)](i) elevation at the branch site (intercostal orifice) was much more pronounced than that at the non-branch area. However, endothelium at the branch site was relatively insensitive to histamine. Both acetylcholine-sensitive and histamine-sensitive endothelial cells were arranged in belts aligned along flow lines and were intercalated with each other. Data analyzed from 400 endothelial cells located at the non-branch site showed drastically heterogeneous [Ca(2+)](i) responses to a fixed concentration of either acetylcholine or histamine, differing by two orders of magnitude in individual cells. As a conclusion, vascular endothelial cells appear to have their own characteristic [Ca(2+)](i) 'fingerprint' to various agonists and they may function coordinately in situ.

Acetylcholine↗
PubMed2000

Effects of chronic exercise on calcium signaling in rat vascular endothelium.

Chronic exercise enhances endothelium-dependent vasodilating responses. To investigate whether this is due to a change in endothelial Ca(2+) signaling, we examined intracellular Ca(2+) concentration ([Ca(2+)](i)) level in rat aortic endothelium in response to acetylcholine (ACh) or ATP. Four-week-old male Wistar rats were divided into control and exercise groups. The exercised animals ran on a treadmill at a moderate intensity for 60 min/day, 5 day/wk, for 10 wk. Rat aortas were then excised and loaded with fura 2. After the aortas were mounted on a flow chamber, these specimens were observed under an epifluorescence microscope equipped with ratio-imaging capability. Our results showed that 1) chronic exercise increased both ACh- and ATP-induced [Ca(2+)](i) responses; 2) ACh induced heterogeneous [Ca(2+)](i) elevation in individual endothelial cells; and 3) the exercise effect on ACh-evoked endothelial [Ca(2+)](i) elevation was inhibited by the Ca(2+) influx blocker SKF-96365, by a Ca(2+)-free buffer, or by high concentrations of extracellular K(+). We conclude that chronic exercise increases ACh-induced [Ca(2+)](i) elevation in rat aortic endothelium in situ, possibly by facilitating Ca(2+) influx.

Acetylcholine↗
PubMed2000

The change of relative incidences of intracranial tumors after the use of computed tomography in Taiwan.

The improved diagnostic capacity of computed tomography (CT) may have resulted in improved detection of intracranial tumors. We were interested to know whether the frequency of intracranial tumors has changed after the introduction of CT in Taiwan. The relative incidences of intracranial tumors in Taiwan were analyzed from the hospital based data. Our data showed that meningiomas were the most encountered intracranial tumors. Neuroepithelial tumors in our series (in the post-CT era) (23.9%) were apparently lower than those found in the pre-CT era (36.0%). However, the relative incidences of meningiomas and pituitary adenomas after the use of CT (24.2%, 21.1%, respectively) were much higher than those found before the use of CT (14.5%, 7.7%, respectively). Our data suggest that the increased incidence for benign tumors and the decreased incidence for malignant tumors may have resulted from the improved diagnostic capacity of CT, which reduces the number of undetected tumor cases.

Adult↗
PubMed2000

Clinical significance of distribution patterns of P53 immunoreactivity in astrocytic tumors.

The difference of prognosis in patients with the same WHO grade of astrocytic tumors suggests that such tumors comprise a heterogeneous group in biological behavior. The correlation between p53 immunoreactivity and prognosis has often been reported but remains controversial. From the perspective of clonal expansion of p53 immunopositive cells, the distribution patterns of p53 immunoreactivity can be divided into four types: negative, scattered, focally clustered, and diffusely clustered. The survival rate was evaluated by classifying the p53 immunoreactivity into two groups: the significantly immunopositive patterns (focally and diffusely clustered types) and the significantly immunonegative patterns (negative and scattered types). The survival analysis showed a highly significant difference between these two patterns within the same WHO grade of astrocytic tumors (p = 0.0185). Our studies demonstrate that the distribution patterns of p53 immunoreactivity, which reflect the trends of clonal expansion of p53 immunopositive cells, are significantly valuable in predicting the prognosis of patients with the same WHO grade of astrocytic tumors.

Adult↗
PubMed2000

[Studies on identification of circumsporozoite protein genotyping of Plasmodium vivax].

OBJECTIVE: To develop a new method of genotyping circumsporozoite protein (CSP) gene for identification of field isolates of Plasmodium vivax. METHODS: Improved Chelex-100 ion-exchange method was used to extract DNA from blood filter paper samples, nested PCR and allele-specific PCR techniques, agarose gel electrophoresis analysis and dot/southern blotting-probe hybridization were employed for amplification, resolution and identification of the diagnostic fragments. RESULTS: Using the nest-allele-specific PCR assay reported here, small amounts of DNA extracted from a piece of blood filter paper sample were amplified which produced three different size ranges of diagnostic bands: 650-770 bp PV-species-specific band, 170-230 bp diagnostic band for temperate zone family and 588 bp band for PV type-2. The sizes and patterns of the bands produced by the reference strains were consistent with those of designed target sequences. Of 59 examined isolates from 6 provinces of China, 42 temperate zone family strains, 15 tropical zone family strains and two PV type-2 strains were identified. CONCLUSION: 1, Three genotype strains of P. vivax mentioned above could be identified by this method with only two rounds of PCR and without probe hybridization. 2, The preliminary results showed that PV type-1 including temperate zone family strains and tropical zone family strains as well as PV type-2 strains are present in China. In addition, another CSP genotype with both sequence characteristics of temperate zone and tropical zone family might also be present in China.

Animals↗