A genetic approach toward defining the role of Factor X in development and coagulation

Activated Factor X (FX) is a vitamin K-dependent serine protease that plays a crucial role in blood coagulation by converting prothrombin to thrombin. There are no humans with complete deficiency of FX. The overall objective of this study is to investigate the role of FX in development and coagulation by generating FX-deficient mouse models and determining the embryonic pattern of FX expression. First, a FX knock-out mouse model was engineered by eliminating FX exon 8 and its 3’ flanking sequence; this resulted in embryonic or perinatal lethality in FX -/- mice. Approximately 50% of FX -/- embryos died between days 10-12 of development. Fatal bleeding in the remaining FX(-/-) animals occurred soon after birth. The cause of embryonic lethality remains unclear. Next, a viable mouse model of FX deficiency was generated. These mice expressed a FX variant with normal antigen levels but a low level of activity (4-9% in humans carrying the analogous defect, Pro343→Ser, termed FX Friuli). Homozygous mice had FX coagulation activity of ~5.5% of normal, which was sufficient to rescue both embryonic and perinatal lethality. To generate mice with even lower FX activity, FX(F/F) and FX(+/-) mice were crossed. Their offspring, FX(-/F) mice, indeed had even lower FX activity (1-3% of normal) and nonetheless also showed complete rescue of embryonic and perinatal lethality. Therefore, while complete absence of FX is incompatible with murine and human survival, minimum FX activity as low as 1% demonstrates sufficiency in rescue of FX knockout mice from lethality. FX(-/F) mice provided an opportunity to assess the relative contributions of maternal and embryonic FX as well as FX activity and antigen to embryonic survival. FX(-/F) mice also facilitated investigation into a developmental role of FX by allowing for examination of FX(-/-) embryos born to mothers with minimal levels of FX activity. Furthermore, FX expression in multiple embryonic tissues was detected by in situ hybridization and immunostaining. Combined, these results represent an initial investigation into defining the role of FX in development.Ph.D., Biomedical Science -- Drexel University, 200

Non-invasive and transdermal measurement of blood uric acid level in human by electroporation and reverse iontophoresis

The aim of this study was to find out the optimum combination of electroporation (EP) and reverse iontophoresis (RI) on noninvasive and transdermal determination of blood uric acid level in humans. EP is the use of high-voltage electric pulse to create nano-channels on the stratum corneum, temporarily and reversibly. RI is the use of small current to facilitate both charged and uncharged molecule transportation across the skin. It is believed that the combination of these two techniques has additional benefits on the molecules’ extraction across the human skin. In vitro studies using porcine skin and diffusion cell have indicated that the optimum mode for transdermal uric acid extraction is the combination of RI with symmetrical biphasic direct current (current density = 0.3 mA/cm2; phase duration = 180 s) and EP with 10 pulses per second (voltage = 100 V/cm2; pulse width = 1 ms). This optimum mode was applied to six human subjects. Uric acid was successfully extracted through the subjects’ skin into the collection solution. A good correlation (r2 = 0.88) between the subject’s blood uric acid level and uric acid concentrations in collection solutions was observed. The results suggest that it may be possible to noninvasively and transdermally determine blood uric acid levels

Women with endometriosis have higher comorbidities: Analysis of domestic data in Taiwan

AbstractEndometriosis, defined by the presence of viable extrauterine endometrial glands and stroma, can grow or bleed cyclically, and possesses characteristics including a destructive, invasive, and metastatic nature. Since endometriosis may result in pelvic inflammation, adhesion, chronic pain, and infertility, and can progress to biologically malignant tumors, it is a long-term major health issue in women of reproductive age. In this review, we analyze the Taiwan domestic research addressing associations between endometriosis and other diseases. Concerning malignant tumors, we identified four studies on the links between endometriosis and ovarian cancer, one on breast cancer, two on endometrial cancer, one on colorectal cancer, and one on other malignancies, as well as one on associations between endometriosis and irritable bowel syndrome, one on links with migraine headache, three on links with pelvic inflammatory diseases, four on links with infertility, four on links with obesity, four on links with chronic liver disease, four on links with rheumatoid arthritis, four on links with chronic renal disease, five on links with diabetes mellitus, and five on links with cardiovascular diseases (hypertension, hyperlipidemia, etc.). The data available to date support that women with endometriosis might be at risk of some chronic illnesses and certain malignancies, although we consider the evidence for some comorbidities to be of low quality, for example, the association between colon cancer and adenomyosis/endometriosis. We still believe that the risk of comorbidity might be higher in women with endometriosis than that we supposed before. More research is needed to determine whether women with endometriosis are really at risk of these comorbidities

Genome-Wide Association Study of Young-Onset Hypertension in the Han Chinese Population of Taiwan

Young-onset hypertension has a stronger genetic component than late-onset counterpart; thus, the identification of genes related to its susceptibility is a critical issue for the prevention and management of this disease. We carried out a two-stage association scan to map young-onset hypertension susceptibility genes. The first-stage analysis, a genome-wide association study, analyzed 175 matched case-control pairs; the second-stage analysis, a confirmatory association study, verified the results at the first stage based on a total of 1,008 patients and 1,008 controls. Single-locus association tests, multilocus association tests and pair-wise gene-gene interaction tests were performed to identify young-onset hypertension susceptibility genes. After considering stringent adjustments of multiple testing, gene annotation and single-nucleotide polymorphism (SNP) quality, four SNPs from two SNP triplets with strong association signals (−log10(p)>7) and 13 SNPs from 8 interactive SNP pairs with strong interactive signals (−log10(p)>8) were carefully re-examined. The confirmatory study verified the association for a SNP quartet 219 kb and 495 kb downstream of LOC344371 (a hypothetical gene) and RASGRP3 on chromosome 2p22.3, respectively. The latter has been implicated in the abnormal vascular responsiveness to endothelin-1 and angiotensin II in diabetic-hypertensive rats. Intrinsic synergy involving IMPG1 on chromosome 6q14.2-q15 was also verified. IMPG1 encodes interphotoreceptor matrix proteoglycan 1 which has cation binding capacity. The genes are novel hypertension targets identified in this first genome-wide hypertension association study of the Han Chinese population

Identification of IGF1, SLC4A4, WWOX, and SFMBT1 as Hypertension Susceptibility Genes in Han Chinese with a Genome-Wide Gene-Based Association Study

Hypertension is a complex disorder with high prevalence rates all over the world. We conducted the first genome-wide gene-based association scan for hypertension in a Han Chinese population. By analyzing genome-wide single-nucleotide-polymorphism data of 400 matched pairs of young-onset hypertensive patients and normotensive controls genotyped with the Illumina HumanHap550-Duo BeadChip, 100 susceptibility genes for hypertension were identified and also validated with permutation tests. Seventeen of the 100 genes exhibited differential allelic and expression distributions between patient and control groups. These genes provided a good molecular signature for classifying hypertensive patients and normotensive controls. Among the 17 genes, IGF1, SLC4A4, WWOX, and SFMBT1 were not only identified by our gene-based association scan and gene expression analysis but were also replicated by a gene-based association analysis of the Hong Kong Hypertension Study. Moreover, cis-acting expression quantitative trait loci associated with the differentially expressed genes were found and linked to hypertension. IGF1, which encodes insulin-like growth factor 1, is associated with cardiovascular disorders, metabolic syndrome, decreased body weight/size, and changes of insulin levels in mice. SLC4A4, which encodes the electrogenic sodium bicarbonate cotransporter 1, is associated with decreased body weight/size and abnormal ion homeostasis in mice. WWOX, which encodes the WW domain-containing protein, is related to hypoglycemia and hyperphosphatemia. SFMBT1, which encodes the scm-like with four MBT domains protein 1, is a novel hypertension gene. GRB14, TMEM56 and KIAA1797 exhibited highly significant differential allelic and expressed distributions between hypertensive patients and normotensive controls. GRB14 was also found relevant to blood pressure in a previous genetic association study in East Asian populations. TMEM56 and KIAA1797 may be specific to Taiwanese populations, because they were not validated by the two replication studies. Identification of these genes enriches the collection of hypertension susceptibility genes, thereby shedding light on the etiology of hypertension in Han Chinese populations

Preferred orientation control and characterization of AlN thin films using reactive sputtering”, Tamkang

Abstract This article presents a study of the influence of the sputtering parameters on the preferred orientation of polycrystalline aluminum nitride thin films. Aluminum nitride films are deposited by reactive dc magnetron sputtering using an aluminum target in an N 2 /Ar gas mixture. In this study, the influences of substrate temperature and target-substrate spacing on film property will be studied. Measurements of the piezoelectric strain constant d 33 are performed in order to effectively evaluate the piezoelectric characteristics of the films. X-ray diffraction (XRD) measurements are also made to investigate the influence on the AlN crystallographic orientation. The film texture index Π hkl is used to quantify how much of the film is oriented along the [hkl] direction. The calculated maximum mean d 33 is 2.7 pm/V at 300°C for AlN/Mo