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Biomedical subjects

H Y Su

Publications and source records attributed to H Y Su.

At least 19 recordsLinked to original sources
PubMed2005

Cloning and nucleotide sequencing of the second internal transcribed spacer of ribosomal DNA for three species of Eimeria from chickens in Taiwan.

Coccidiosis of chickens caused by protozoan parasites of the genus Eimeria (Coccidia: Eimeriidae) is an enteric disease that results in great economic losses throughout the world, including Taiwan. Using polymerase chain reaction (PCR) with primers specific for the second internal transcribed spacer (ITS-2) of ribosomal DNA (rDNA), three species of Eimeria, E. tenella, E. maxima, and E. acervulina have been successfully characterised from chickens in Taiwan. The sizes of PCR products from various isolates representing these three species were between 370 and 580 base pairs (bp). After cloning and sequencing of the PCR products, high nucleotide sequence identity (96.8-100%) was observed within a species. In addition, ITS-2 nucleotide sequences for E. tenella had higher homology (98.5-99.3%) than E. maxima (81.6-96.5%) when compared with appropriate sequences deposited in GenBank. To our knowledge, this is the first report of a 412-bp ITS-2 sequence for E. acervulina from chickens.

Animals↗
PubMed2004

Pistil induction by hormones from callus of Oryza sativa in vitro.

This study describes the successful formation of floral organ pistil from the callus of pistil explants of Oryza sativa L. For induction of floral organs, different explants--including young embryo, lemma, palea and pistil--were used for callus induction with different combinations of N(6)-benzyladenine and 2,4-dichlorophenoxyacetic acid (2,4-D). High frequencies of callus formation from pistil and young embryo explants were achieved. Floral organs were induced after calli from pistils were transferred to medium containing both zeatin and 2,4-D. The morphological characteristics of the pistil-like organs are very similar to those formed in planta though with minor differences. Further histological study revealed that the in vitro pistil contains an ovule within its ovary. Furthermore, a pistil-specific gene, OsMADS3 used as a molecular marker for pistil identity, was expressed in the pistil-like organs as it was in pistils in the flower of the plant.

2,4-Dichlorophenoxyacetic Acid↗
PubMed2004

Increased milk yield in transgenic mice expressing insulin-like growth factor 1.

Insulin-like growth factor 1 (IGF-1) mediates many of the actions of growth hormone. Overexpression of IGF-1 was reported to have endocrine and paracrine/autocrine effects on somatic growth in transgenic mice. To study the paracrine/autocrine effects of IGF-1 in mammary gland, transgenic mice were produced by pronuclear microinjection of a construct containing a bovine alpha-lactalbumin (alpha-LA) promoter linked to an ovine IGF-1 cNDA. This alpha-LA promoter has previously been shown to direct expression of a human factor VIII gene specifically to the mammary gland of transgenic mice. Three transgenic mouse lines were established as a result of microinjection of 398 embryos. Transgene expression was found in mammary gland at day 1 of lactation from these three lines. Progeny test were carried out by mating two transgenic males/one transgenic female to two nontransgenic females/one nontransgenic male. Mice from one line (line 1225) were all nonexpressors and the other (line 1372) failed to produce offspring. Milk yield was analyzed in the line 1137 that produced 10 mice, of which three were transgenic females and three nontransgenic females. All of the three transgenic females showed integration of the transgene and expressed transgene IGF-1 mRNA in the mammary gland. Milk yields from days 5, 10, and 15 of lactation were significant greater in transgenic expressors than in their nontransgenic littermates. Specifically, there is 17.9% increase in total milk yield from these three days for transgenics compared with nontransgenics. These results demonstrate that local overexpression of IGF-1 in transgenic mice is capable to stimulating milk yield during the first lactation.

Animals↗
PubMed2004

Characterization of porcine leptin receptor polymorphisms and their association with reproduction and production traits.

Fatness in pigs is of prime economic importance due to market incentives for production of lean pork and elevated fatness increasing the feed costs. Leptin (LEP) action, mediated through its specific receptors (LEPR), was reported to be involved in the regulation of fatness via feed intake, energy expenditure, and whole-body energy balance in pigs. In this study, we have designed 17 primer sets based on the human and mouse LEPR sequences and successfully amplified coding regions of 15 porcine LEPR exon fragments by polymerase chain reactions (PCR). Four single nucleotide polymorphisms (SNP) of Intron 2, Exons 2, 6, and 18 were found in Landrace, Yorkshire, and Duroc by mutagenetically separated-PCR (MS-PCR) and PCR-restriction fragment length polymorphisms (PCR-RFLP). Chi-square statistics was used to calculate homogeneity of genotypic frequencies of 4 gene polymorphisms for three breeds of animals. Effects of Intron 2, Exon 2, and Exon 18 polymorphisms on the reproduction trait such as litter sizes of sows were evident (p < 0.05) in Duroc and Yorkshire. There was no (p > 0.05) significant influence on the production trait of average daily gain due to four candidate gene polymorphisms in three porcine breeds. However, effects of Exon 6 and 18 polymorphisms on the production trait of backfat thickness were significant (p < 0.05) in Landrace and Yorkshire, respectively. Effects of Exon 18 polymorphisms on feed efficiency were also evident (p < 0.05) in Duroc.

Animals↗
PubMed2001

Differential expression of a gene homologous to a G-alpha protein gene in neonatal mouse skin during development of hair follicles.

The development of mouse hair follicles depends on the proliferation, differentiation and migration of epithelial matrix cells in the follicle bulb. In particular, induction of the proliferation of epithelial cells is thought to be signalled by the dermal papilla at the base of the bulb. Neonatal mouse skin is useful for studying changes in gene expression during development of the follicles, as the mitotic activity of skin cells changes shortly after birth. Using RNA differential display, a 248-bp message has been identified, which is expressed in the skin, specifically on day 2 and day 3 but not on day 4 after birth. Confirmation of expression of this gene by ribonuclease protection assay showed that strong expression is seen on day 2 and day 3, but weak expression is also shown on day 1, day 4 and day 5. In situ hybridization data revealed that it is mainly localized in the dermal papilla. Analysis of its nucleotide sequence showed 99% identity between nucleotide 2 and 232 of the mouse uncoupled S49 cell mRNA for stimulatory GTP-binding protein (G(S)) alpha subunit, suggesting it is a segment of G(S)alpha. As the G(S)alpha subunit is involved in transducing extracellular signals across the cell, the finding of its expression in the papilla suggests it may be a molecular signal to the induction of epithelial proliferation in the follicle bulb. Evidence of strong expression on day 2, at the time when the mitotic activity of epithelial matrix cells starts to increase, also suggests that the G(S)alpha is a potential candidate for involvement in the initiation of follicle growth.

Aging↗
PubMed2000

Single nucleotide polymorphisms in an intron of the ovine calpastatin gene.

Calpastatin is the specific inhibitor of the ubiquitous calcium-dependent proteases mu-calpain and m-calpain. Enzyme assay data from sheep and cattle inversely correlates post-mortem muscle calpastatin levels with ultimate meat tenderness. Genetic markers of meat quality may therefore be found linked to the calpastatin gene (CAST). A three-allele system detected by polymerase chain reaction-single strand conformational polymorphism (PCR-SSCP) has been observed in the ovine CAST. The three allele amplimers have been fully nucleotide sequenced and their differences in terms of single nucleotide polymorphism (SNPs) in the intron region of the amplimer are reported and compared to a consensus sequence of the orthologous region of the cattle CAST. A PCR-RFLP for more rapid CAST genotyping of all three ovine alleles was also developed.

Alleles↗
PubMed2000

Erythema induratum associated with tuberculous lymphadenitis: analysis of a case using polymerase chain reactions with different primer pairs to differentiate bacille Calmette-Guérin (BCG) from virulent strains of Mycobacterium tuberculosis complex.

We retrospectively analyzed a bacille Calmette-Guérin (BCG) vaccinated female patient who developed erythema induratum in association with tuberculous lymphadenitis. The polymerase chain reaction (PCR) with two pairs of primers was performed. Only one pair was able to detect the myocobacterial DNA from the paraffin-embedded specimen of the erythema induratum (EI) lesion. However, both pairs showed positive results with the tuberculous lymphadenitis specimen. Sequence analysis of the PCR products excluded the possibility of BCG as the potential pathogen. Both lesions responded favorably to antituberculous therapy. Our study attests to the tuberculous nature of EI and demonstrates that BCG vaccination per se does not induce the lesion or interfere with the PCR result. Finally, using at least two pairs of primers targeting different genomic segments and possessing species-identification capability may raise the detection rates and solve some controversies about the nature of tuberculids.

Adult↗
PubMed2000

Survey of infectious skin diseases and skin infestations among primary school students of Taitung County, eastern Taiwan.

BACKGROUND: There are no complete records on the prevalence of childhood skin diseases in Taiwan. We conducted a survey of infectious skin diseases and skin infestations among primary school children in Taitung County, which is located in southeastern Taiwan. METHODS: From March 1998 through October 1998, a total of 3,029 students from four rural districts (Changbin, Yanping, Lanyu, and Dawu) and one urban area (Taitung City of Taitung County) were examined by dermatologists. Treatment and instructions for disease care were given immediately after the diagnosis of dermatoses, when appropriate. RESULTS: The most common infectious skin diseases and infestations were pediculosis capitis (12.9%), verruca vulgaris (5.1%), tinea versicolor (4.4%), tinea pedis (4.1%), verruca plantaris (1.8%), and scabies (1.4%). Most skin diseases, including pediculosis capitis, scabies, verruca vulgaris, verruca plantaris, folliculitis, pyoderma, tinea pedis, and tinea versicolor, were significantly more common in rural areas than in the urban area (p < 0.05 for all). Pediculosis capitis was more common among girls (p < 0.001), but tinea pedis and tinea versicolor were more common among boys (p < 0.05). CONCLUSIONS: The prevalence of most skin infections and infestations are much higher in rural Taitung County than in Taitung City. Prevention and treatment of these skin diseases should be reemphasized in the education of teachers, as well as students and their families. Adequate dermatologic training of nurses and physicians and the development of teleconsultation and teledermatology in rural areas might decrease the prevalence of these skin diseases in school children.

Child↗
PubMed1999

Increased vibrissa growth in transgenic mice expressing insulin-like growth factor 1.

Insulin-like growth factor 1 (IGF-1) mediates many of the actions of growth hormone. Overexpression of IGF-1 has been reported to have endocrine and paracrine/autocrine effects on somatic growth in transgenic mice. To study the paracrine/autocrine effects of IGF-1 in hair follicles, transgenic mice were produced by pronuclear microinjection of a construct containing a mouse ultra-high sulfur keratin (UHS-KER) promoter linked to an ovine IGF-1 cDNA. This UHS-KER promoter has previously been shown to direct expression of a reporter gene to the hair follicles of transgenic mice. Four transgenic mouse lines were established as a result of microinjection of 435 embryos. Transgene expression was found in skin at day 8 and day 15 of age in three of the lines. Progeny tests were carried out by mating two of the transgenic expressing males to nontransgenic females. Mice from one line were all nonexpressors while four of the 12 mice from the other showed integration of the transgene and three expressed transgene IGF-1 mRNA in the skin. Vibrissa growth at 11-21 d of age was significantly greater in transgenic expressors than in their nontransgenic littermates. Specifically, the increase in vibrissa length for transgenics at days 11-16 (20.5%) is approximately 2-fold compared with days 16-21 (11.9%). These results demonstrate that local overexpression of IGF-1 in transgenic mice is capable of stimulating vibrissa growth during the first neonatal hair cycle.

Animals↗
PubMed1999

Insulin-like growth factor 1 and hair growth.

Insulin-like growth factor 1 (IGF-1) has been identified as an important growth factor in many biological systems.[1] It shares considerable structural homology with insulin and exerts insulin-like effects on food intake and glucose metabolism. Recently it has been suggested to play a role in regulating cellular proliferation and migration during the development of hair follicles. [2,3] To exert its biological effects, the IGF-1 is required to activate cells by binding to specific cell-surface receptors. The type I IGF receptor (IGF-1R) is the only IGF receptor to have IGF-mediated signaling functions.[1] In circulation, this growth factor mediates endocrine action of growth hormone (GH) on somatic growth and is bound to specific binding proteins (BPs). The latter control IGF transport, efflux from vascular compartments and association with cell surface receptors.[4] In tissues, IGF-1 is produced by mesenchymal type cells and acts in a paracrine and autocrine fashion by binding to the IGF-1R. This binding activates the receptor tyrosine kinase (RTK) that triggers the downstream responses and finally stimulates cell division.[5] IGF-1 may therefore be able to stimulate the proliferation of hair follicle cells through cellular signaling pathways of its receptors. Local infusion of IGF-1 into sheep has been reported to be capable of stimulating protein synthesis in the skin.[6] It may also increase the production of wool keratin. Recently, transgenic mice overexpressing IGF-1 in the skin have been shown to have earlier hair follicle development than controls.[7] In addition, this growth factor plays an important role in many cell types as a survival factor to prevent cell death.[8] This anti-apoptotic function of IGF-1 may be important to the development of follicle cells as follicles undergo a growth cycle where the regressive, catagen phase is apoptosis driven. In this review, the effects of IGF-1 on follicle cell proliferation and differentiation are discussed. In particular, the paracrine versus endocrine action of IGF-1 on hair growth and the targeting of expression of the growth factor to the follicles of transgenic animals will be emphasized. The anti-apoptotic role of IGF-1 in hair follicles is also reviewed. Prospects for future studies on hair and fiber growth by IGF-1 are discussed.

Androgens↗
PubMed1998

Wool production in transgenic sheep: results from first-generation adults and second-generation lambs.

In sheep transgenic for a sheep insulin-like growth factor 1 (IGF-1) cDNA driven by a mouse keratin promoter, we assessed wool production and properties in 51 adults of the first generation (G1) and in 56 lambs of the second generation (G2). Transgenic G1 sheep had an increased rate of wool production during spring and summer of year 2 compared with nontransgenic half-sibs, with a maximum increase of 17% in December, but during the winter nadir rates were similar. At second- and third-year shearing, however, fleece weights were not significantly different. There was a trend for transgenic animals to have coarser wool of lower staple strength. A controlled feeding trial revealed no significant differences in feed intake. The transgene was expressed not only in skin but also in a wide range of other tissues. Circulating IGF-1 concentrations were not significantly different between transgenic and nontransgenic animals, suggesting that local mechanisms were more important than systemic mechanisms for wool production, but were significantly higher in males than in females. In the G2 sheep, transgenic fleece weight did not differ significantly from nontransgenic either as lambs or at the end of the lamb year. Although the transgene was inherited in Mendelian fashion and was widely expressed, the production advantage seen in animals of the first generation did not persist in the second generation.

Animal Husbandry↗
PubMed1998

Effect of weight loss on resting energy expenditure in hypertensive and normotensive obese women.

Hyperinsulinemia and the associated increased sympathetic nervous activity have been proposed to implicate in the development of hypertension and obesity. The role of hyperinsulinemia in mediated resting energy expenditure (REE) in hypertensive obese subjects is not clear. The effect of weight loss on REE between hypertensive and normotensive obese women are also unknown. We measured fasting plasma glucose, insulin, lipids concentrations, REE and body composition by bioelectrical impedance methods before and after a weight loss program in 9 newly diagnosed hypertensive and 10 normotensive obese women. As compared with age-matched lean control women (n=14), obese subjects had higher fasting plasma glucose, insulin concentrations and REE values. However, these variables were not different between obese groups. Although REE and fasting plasma insulin concentrations correlated well in simple correlation (r=0.708, p<0.001), this relationship disappeared after adjusting for values of fat free mass (FFM). Weight loss for approximately 10% of initial weight led to significant decreases of blood pressure and fasting plasma insulin concentrations in both obese groups. Fasting plasma cholesterol, LDL cholesterol and triglyceride concentrations decreased in hypertensive obese individuals. Significant fall of REE in hypertensive group (p<0.05) and normotensive group (p<0.02) were observed following weight loss. However, the ratio of REE to FFM decreased significantly only in hypertensive subjects (114.6+/-5.2 KJ/day x Kg(-1) to 107.2+/-4.6 KJ/day x Kg(-1), p<0.05). In conclusion, obese women, either hypertensive or normotensive, had higher fasting plasma insulin concentrations and REE than those of lean controls, although these variables were not different between obese groups. No significant relation between fasting plasma insulin and REE could be found. Weight loss produced a significant decrease of REE/FFM only in hypertensive obese women. Further study to evaluate the effect of weight loss on energy expenditure in hypertensive obese subjects is necessary.

Adult↗
PubMed1995

Emodin inhibits the mutagenicity and DNA adducts induced by 1-nitropyrene.

Polygonum cuspidatum S. (PC) is frequently used as a laxative and an anticancer drug in Chinese medicine. The inhibitory effect of this herb and its component, emodin, on the direct-acting mutagenicity of 1-nitropyrene (1-NP) was examined using the Ames/microsomal test with Salmonella typhimurium TA98 and the genotoxicity of 1-NP was evaluated using the SOS chromotest with E. coli PQ37. Emodin and water extracts of PC markedly decreased the mutagenicity of 1-NP in a dose-dependent manner in both assay systems. Furthermore, emodin and the extracts of PC significantly inhibited the formation of 1-NP DNA adducts in S. typhimurium TA98 in the 32P-postlabeling study. The results suggest that PC extracts and emodin act as blocking and/or suppressing agents to reduce the direct-acting mutagenicity of 1-NP.

Antimutagenic Agents↗
PubMed1995

Effect of weight loss on blood pressure and insulin resistance in normotensive and hypertensive obese individuals.

In this study, the effect of weight loss on blood pressure and various facets of glucose and insulin metabolism was examined in 22 subjects with mild to moderate obesity; 11 with high blood pressure (diastolic blood pressure > 95 mm Hg) and 11 with normal blood pressure (diastolic blood pressure < 90 mm Hg). The two groups were similar in mean (+/- SEM) body mass index at baseline (30.2 +/- 1.0 v 31.6 +/- 1.1 kg/m2), and each group lost approximately 8 kg during the 3-month study period. Blood pressure fell significantly (P < .003) following the 8 kg weight loss in both the normotensive (122 +/- 3/81 +/- 3 to 110 +/- 3/74 +/- 2 mm Hg) and hypertensive (149 +/- 3/98 +/- 1 to 135 +/- 3/86 mm Hg) subjects. Furthermore, the plasma glucose and insulin responses to a 75 g oral glucose load were significantly lower (P < .001) following weight loss. Finally, insulin resistance, as assessed by determining the steady-state plasma glucose (SSPG) concentration at the end of a 180 min infusion of somatostatin, insulin, and glucose, was also lower (P < .002) after the 8 kg weight loss in the normotensive (243 +/- 23 to 172 +/- 15 mg/dL) and hypertensive subjects (266 +/- 18 to 181 +/- 25 mg/dL). Since the steady-state plasma insulin concentrations were, if anything, slightly lower after weight loss in both groups, the lower post-weight loss SSPG values actually underestimate the improvement of insulin resistance. Thus, weight loss of 8 kg in moderately obese individuals leads to significant decreases in blood pressure and plasma glucose and insulin concentrations in response to an oral glucose challenge and degree of insulin resistance.

Adult↗
PubMed1994

The structure-activity relationships of flavonoids as inhibitors of cytochrome P-450 enzymes in rat liver microsomes and the mutagenicity of 2-amino-3-methyl-imidazo[4,5-f]quinoline.

The antimutagenicity of 19 naturally occurring flavonoids and their derivatives including flavones, flavonols, flavanones, isoflavones and flavanols were determined using Salmonella typhimurium TA98 against 2-amino-3-methylimidazo[4,5-f] quinoline (IQ) in the presence of Aroclor 1254-induced rat hepatic S9. In general, a relationship between the chemical structure of flavonoids and their antimutagenicity was found for compounds containing one or more of the following features: (i) C4 keto group, (ii) aglycone, (iii) double bond at positions C2 and C3, (iv) phenyl group at position C2, and (v) three hydroxy substituents at positions C4', C5 and C7. The inhibitory effects of flavonoids on activities of 7-ethoxycoumarin deethylase (ECD) and 7-ethoxyresorufin deethylase (ESD) of Aroclor 1254-induced hepatic microsomes were also examined. In addition, we studied the effects of flavonoids on the metabolism of IQ by Aroclor 1254-induced microsomes using high-performance liquid chromatography. The antimutagenicity correlated with the inhibition of cytochrome P-450IA1-linked ESD and P-450IA2-linked ECD activity in hepatic microsomes, and with an inhibition of N-hydroxy-IQ formation from IQ metabolism by hepatic microsomes. These results indicated that flavones or flavonols that contain C5, C7 and C4' hydroxyl groups are potent inhibitors of P-450 enzyme activities induced by Aroclor 1254 (P-450IA1 and P-450IA2), and may potentially be useful as chemopreventive agents against heterocyclic amine-induced mutagenesis or carcinogenesis.

7-Alkoxycoumarin O-Dealkylase↗