Cross-border reproductive care use by women with infertility in Hong Kong: cross-sectional survey.

OBJECTIVES: Cross-border reproductive care (CBRC) is an increasingly common global phenomenon, but there is a lack of information regarding its frequency among residents of Hong Kong. This study aimed to evaluate the use of CBRC and the factors affecting its use among residents of Hong Kong. METHODS: This cross-sectional questionnaire study collected data from 1204 women with infertility who attended Hong Kong Hospital Authority and Family Planning Association infertility clinics. RESULTS: In total, 178 women (14.8% of all respondents) had used CBRC. Among respondents who had not used CBRC, 36.3% planned to use or would consider it. The main factors influencing the likelihood of using CBRC among women with infertility in Hong Kong use were long waiting times in the public sector and high cost in the private sector. Taiwan was the most preferred destination for CBRC (69.6% of respondents). Most information concerning CBRC was accessed via the internet. More than two thirds of respondents believed that the government in Hong Kong should formulate some regulations or guidance regarding CBRC. CONCLUSION: Nearly one in six women with infertility in Hong Kong had used CBRC. Among women who had not used CBRC, more than one third planned to use or would consider it. The main factors influencing the likelihood of CBRC use were long waiting times in the public sector and high cost in the private sector. These results will help clinicians to more effectively counsel patients considering CBRC and facilitate infertility services planning by authorities in Hong Kong.

Unraveling the adipocyte inflammomodulatory pathways activated by North American ginseng.

BACKGROUND: North American (NA) ginseng (Panax quinquefolius) is a popular natural health product (NHP) that has been demonstrated to regulate immune function, inflammatory processes and response to stress and fatigue. Recent evidence suggests that various extracts of NA ginseng may have different bioactivities because of distinct profiles of ginsenosides and polysaccharides. To date, the bioactive role of ginseng on adipocytes remains relatively unexplored. OBJECTIVE: The goal of this work was to study the extract-specific bioactivity of NA ginseng on differentiated preadipocyte gene expression and adipocytokine secretion. METHODS: In vitro differentiated 3T3-L1 preadipocytes were treated with 25 and 50 µg ml of either crude ethanol (EtOH) or aqueous (AQ) NA ginseng extracts, or polysaccharide and ginsenoside extracts isolated from the AQ extract. Global gene expression was studied with microarrays and the resulting data were analyzed with functional pathway analysis. Adipocytokine secretion was also measured in media. RESULTS: Pathway analysis indicated that the AQ extract, and in particular the polysaccharide extract, triggered a global inflammomodulatory response in differentiated preadipocytes. Specifically, the expression of Il-6 (interleukin 6), Ccl5 (chemokine (C-C motif) ligand 5), Nfκb (nuclear factor-kappaB) and Tnfα (tumor necrosis factor alpha) was increased. These effects were also reflected at the protein level through the increased secretion of IL-6 and CCL5. No effect was seen with the EtOH extract or ginsenoside extract. Using a specific toll-like receptor 4 (TLR4) inhibitor reduced the upregulation of inflammatory gene expression, indicating the relevance of this pathway for the signaling capacity of NA ginseng polysaccharides. CONCLUSION: This work emphasizes the distinct bioactivities of different ginseng extracts on differentiated preadipocyte signaling pathways, and highlights the importance of TLR4 for mediating the inflammomodulatory role of ginseng polysaccharides.

Grain structure control during metal 3D printing by high-intensity ultrasound.

Additive manufacturing (AM) of metals, also known as metal 3D printing, typically leads to the formation of columnar grain structures along the build direction in most as-built metals and alloys. These long columnar grains can cause property anisotropy, which is usually detrimental to component qualification or targeted applications. Here, without changing alloy chemistry, we demonstrate an AM solidification-control solution to printing metallic alloys with an equiaxed grain structure and improved mechanical properties. Using the titanium alloy Ti-6Al-4V as a model alloy, we employ high-intensity ultrasound to achieve full transition from columnar grains to fine (~100 µm) equiaxed grains in AM Ti-6Al-4V samples by laser powder deposition. This results in a 12% improvement in both the yield stress and tensile strength compared with the conventional AM columnar Ti-6Al-4V. We further demonstrate the generality of our technique by achieving similar grain structure control results in the nickel-based superalloy Inconel 625, and expect that this method may be applicable to other metallic materials that exhibit columnar grain structures during AM.

Chronic corticosterone-induced impaired cognitive flexibility is not due to suppressed adult hippocampal neurogenesis.

Hippocampal neurogenesis has been implicated in the etiology of depression. Recent studies suggest new neurons add flexibility to hippocampal-dependent learning and memory. We hypothesized that suppressed hippocampal neurogenesis may contribute to impaired cognitive flexibility associated with depression. The chronic corticosterone (CORT)-induced animal model of depression was used. In Experiment 1, rats received either CORT (40mg/kg) or vehicle injections for 21days and were subjected to Water maze during the last six days of drug treatment. No group differences were found during the spatial learning phase; however, cognitive flexibility, measured by reversal training, was significantly impaired in the CORT-treated rats. The probe test revealed enhanced memory of the new platform location for the CORT-treated rats. Given the time newborn neurons require to mature, we presumed if impaired cognitive flexibility seen in Experiment 1 were due to suppressed neurogenesis, terminating CORT treatment 3days prior to behavioural testing should still induce the impairment. Therefore, Experiment 2 was similar to Experiment 1, except that CORT injections were terminated 3days prior to behavioural assessment. However, not only was spatial learning significantly enhanced in the CORT-treated rats, but there were also no group differences during reversal or probe tests. Bromodeoxyruidine, administered a day after the first drug treatments in both experiments, was quantified and revealed the number of new neurons were the same in both groups in both experiments. Results suggest cognitive flexibility is impaired in the CORT-induced animal model of depression; an effect that is reversible and independent of suppressed hippocampal neurogenesis.

Aberrant methylation of cyclooxygenase-2 in breast cancer patients.

BACKGROUND: Although aberrant CpG island methylation and subsequent silencing of the cyclooxygenase-2 (COX-2) promoter has been observed in colorectal and gastric tumors recently, little is known about that in breast cancers. The aim of this study was to identify the methylation status of COX-2 as well as to determine the association between clinical characteristics and COX-2 methylation in breast cancer patients. METHODS: Using bisulfite modification and a methylation-specific PCR, we examined the methylation status of the COX-2 promoter in primary tumors from 110 breast cancer patients. Meanwhile, the expression of COX-2 protein was determined by immunohistochemistry (IHC). RESULTS: Twenty out of 110 (18.2%) primary breast cancers showed aberrant methylation of the 5' region of COX-2. Loss of expression of COX-2 protein was found in all tumors with COX-2 methylation. Methylation of COX-2 was strongly correlated with tumor size (P = 0.026), presence of axillary lymph node metastasis (P = 0.001) and lymphovascular permeation (P = 0.034). CONCLUSION: Our data suggest that COX-2 methylation is associated with good prognostic factors in breast cancer patients. COX-2 promoter methylation may be one of the mechanisms by which tumor cells regulate COX-2 expression.

Study of COX-2, Ki67, and p53 expression to predict effectiveness of 5-flurouracil, epirubicin and cyclophosphamide with celecoxib treatment in breast cancer patients.

BACKGROUND: Cyclooxygenase-2 (COX-2) affects cell proliferation, apoptosis, and metastasis of breast cancer, and may also be involved in tumor angiogenesis through vascular endothelial growth factor. Ki67 and p53 are common markers of proliferation and apoptosis in tumor cells. This study investigated the change in expression of COX-2, Ki67, and p53 in solid tumors after the administration of chemotherapeutic drugs. MATERIALS AND METHODS: Fifty patients were eligible to be treated with preoperative 5-fluorouracil, epirubicin, and cyclophosphamide, with celecoxib (FECC). Tumor tissue samples from 10 patients who, diagnosed with invasive ductal carcinoma, completed chemotherapy were examined immunohistochemically for COX-2, Ki67, and p53. RESULTS: From the 60% of patients who expressed COX-2 and 90% who expressed Ki67 and p53 before treatment, 90% of patients revealed a lower intensity staining for each marker after FECC treatment. However, changes in expression of the three markers did not significantly correlate with tumor size, grade, axillary lymph node status. Immunostained slides clearly showed that the diaminobenzidine intensity was markedly reduced after the three-cycle FECC treatment, which implied the combined regimens be effective to the cancer patients. CONCLUSIONS: This study demonstrates a novel relationship between COX-2, Ki67, and p53 expression of human breast invasive ductal carcinomas. This functional relationship provides support for a potential therapeutic role of COX-2 inhibitors in human breast cancer.

DNA hypermethylation of TIMP3 gene in invasive breast ductal carcinoma.

BACKGROUND: Neoplastic cells often display aberrant methylation and silencing of multiple genes, including tumor suppressor genes (TSGs) that regulate critical processes such as cell cycle control, DNA repair and angiogenesis. Tissue inhibitor of metalloproteinase-3 (TIMP3) is an extracellular matrix-bound protein which regulates matrix composition and affects tumor growth, invasion and angiogenesis. It mediates vascular endothelial growth factor (VEGF) by blocking the binding of VEGF to VEGF receptor-2 and inhibits downstream signaling. This study focused on the hypermethylation status of the TIMP3 gene with clinical parameters in invasive breast ductal carcinoma (IDC) samples. MATERIALS AND METHODS: DNA extraction and methylation specific PCR (MSP) was performed on 173 patients with invasive breast carcinoma. Both specific methylated and unmethylated primers for each gene were used for PCR and the products were visualized on agarose gel. The methylation status of TIMP3 was then compared with corresponding patients' clinicopathologic characteristics. RESULTS: Methylation frequencies of TIMP3 in the breast cancer samples were 20.81 %. Among the hypermethylated cancers, 50% were tumor grade II-III, 44.44% were positive in lymph node involvement (LN), 36.11% were positive in lymphovascular permeation (LVP); 44.44%, 22.22% and 47.22% for the overexpressions in estrogen receptor (ER), progesterone receptor(PR) and c-erbB2, respectively. CONCLUSION: The result demonstrated that hypermethylation of TIMP3 in IDC might be associated with high tumor grading and lymph nodes metastasis, and overexpression of ER, PR and c-erbB2, respectively.

Glucagon and related peptides in fetal rat hypothalamus in vivo and in vitro.

Proglucagon-derived peptides are localized in pancreas, intestine, and the nervous system. We have examined the ontogeny of glucagon and related peptides in developing rat hypothalamus and have developed a fetal rat hypothalamic cell culture model to study the synthesis and secretion of these peptides in cells of neural origin. Fetal rat hypothalamus (19-21 day gestation) was found to contain glucagon-like immunoreactive (GLI) peptides including glucagon. The relative amounts of two of the GLI peptides (glicentin and oxyntomodulin) increased with development such that adult hypothalamus contained a predominance of these peptides over glucagon. The ratio of GLI peptides to glucagon increased from 2.6 +/- 0.5 in fetus to 46 +/- 11 in adult (P less than 0.001). When fetal rat hypothalamic cells (FRHC) were placed into primary culture for 7 days, the presence of neurons, glial cells, and glucagon-containing cells was detected by immunohistochemical staining. Analysis of proglucagon gene expression in FRHC cultures by Northern blotting demonstrated the presence of a single proglucagon messenger RNA (mRNA) transcript identical in size and sequence to that detected in fetal pancreas and intestine. RNase protection analysis of RNA from FRHC cultures, brainstem, and intestine confirmed that the proglucagon mRNA transcripts present in these three tissues were identical. Analysis of FRHC content of GLI peptides and immunoreactive glucagon demonstrated that peptide levels were not significantly different from those of whole fetal rat hypothalamus, and did not vary significantly throughout 2 weeks in culture. FRHC cultures were found to contain substantial amounts of glucagon after 1 week of culture. Release of the GLI peptides on day 7 of culture was increased 3-fold (P less than 0.001) by treatment of FRHC for 1 h with 5 mM (Bu)2cAMP. Rat hypothalamus therefore appears to undergo unique changes in posttranslational processing of proglucagon during development. Primary cultures of FRHC thus provide a promising in vitro model to study the molecular control of proglucagon biosynthesis and GLI peptide secretion in the brain.

Developmental profiles of antioxidant enzymes and trace metals in chick embryo.

It has been previously well documented that partial pressure of oxygen (PO2) and weight-specific rate of O2 consumption in chick embryo (Gallus gallus domesticus) transiently increase midway through the 21-day in ovo incubation period. The present study found that these oxidative changes were paralleled by the concentrations of glutathione (GSH) and Zn in liver and by the specific activity of superoxide dismutase (SOD) in brain. Levels of antioxidant enzymes and their trace metal cofactors were markedly higher in liver than in brain. Hepatic catalase activity changed in parallel with the concentration of its cofactor, Fe. However, the relative abundance of metal cofactors did not appear to be the determining influence on other antioxidant enzyme activities. Rates of extra-mitochondrial hydrogen peroxide release were also much greater in liver than in brain. Taken together, the results of this initial study of embryonic chick antioxidant systems suggest that certain antioxidants may be regulated by PO2 and rate of oxidative metabolism during fetal development.

Biochemical mechanism of metallothionein--carbon tetrachloride interaction in vitro.

To elucidate the mechanism underlying the protective effect of metallothionein (MT) against carbon tetrachloride (CCl4) toxicity, in vitro experiments were carried out to study the interaction of metallothionein and CCl4. Results from this study showed that incubation of Cd,Zn-MT with CCl4 in the presence of hepatic microsomes and NADPH resulted in a time-dependent depletion of MT thiols with a concurrent reduction in the metal-binding sites of the protein. Moreover, this reaction also released Zn and Cd from MT. Results from experiments conducted to determine whether or not the CCl4-induced decrease in MT-thiol content was due to the scavenging of CCl4 metabolite(s) showed that the trichloromethyl radical, chloroform and phosgene as well as the products of CCl4-induced microsomal lipid peroxidation were not directly involved. Although covalent binding of 14CCl4 to MT was detected following incubation in the presence of a microsomal bioactivation system, it did not account for the CCl4-induced loss of MT thiol groups for the following reasons: (i) prior oxidation of sulfhydryl groups of MT by hydrogen peroxide did not alter the binding; and (ii) anaerobiosis did not alter the extent of covalent binding but obliterated the inhibitory effect of CCl4 on MT thiol content. Measurement of the thiol content of CCl4-treated MT after treatment with 1,4-dithiothreitol revealed that all the thiol groups that were lost subsequent to CCl4 treatment could be regenerated. These data suggest that CCl4-linked oxidation of MT, rather than the covalent binding of 14CCl4 metabolite(s), may be responsible for the CCl4-induced loss of metal binding sites of MT with the concurrent release of Zn and Cd. However, the precise role of the metal released during the oxidation of MT in CCl4 toxicity remains to be defined.

Effects of long-chain fatty amines on the growth of ras-transformed NIH 3T3 cells.

A number of aliphatic primary amines were tested for their effects on the growth of ras-transformed NIH 3T3 cells (PAP2 cells), as measured by incorporation of tritiated thymidine into DNA. Long-chain, saturated amines (C12 to C18) were growth inhibitory, whereas short-chain amines (C6, C8) were not. Farnesylamine, a branched-chain, unsaturated amine (C15), had an IC50 of 6.9 microM compared to IC50 values of 13.1 to 45.8 microM for straight-chain, saturated amines. Oleylamine, with an IC50 of 0.1 microM, was the most potent inhibitor. The long-chain amines, but not the short-chain amines, were also effective inhibitors of protein kinase C, assayed in vitro in a cell-free system. In addition, studies with indo-1-loaded PAP2 cells showed that long-chain amines induced a reversible rise in intracellular free Ca2+ concentration. Growth inhibition by the amines was positively correlated with this effect, suggesting that factors other than protein kinase C may be involved in the inhibition of growth of PAP2 cells by long-chain amines.

Metabolic activation/deactivation reactions during perinatal development.

The role of metabolic activation/deactivation reactions during development is evaluated in relation to developmental pharmacology and toxicology. Enzyme systems evaluated include the mixed-function oxidases (aryl hydrocarbon hydroxylase and oxidative demethylation), epoxide hydration and conjugation (glutathione conjugation, sulfation, and glucuronidation). Placental transfer and milk secretion of chemicals are discussed in relation to maternal, placental, and fetal metabolism. Normal patterns of enzyme development can be modified in two ways: (1) enzyme induction and (2) enzyme imprinting. Postnatal induction of the mixed-function oxidases and glucuronyl-transferase following treatment of pregnant rats with TCDD is shown to be caused primarily by newborn exposure to TCDD in milk. Structure-activity relationship are defined for the perinatal induction of hepatic enzymes by the pure PCBs. PCBs are divided into two classes: P-450 inducers and P-448 inducers. Imprinting or programming of hepatic metabolism is a function of the sexual differentiation of enzyme activity; male and female activities are similar in prepubertal animals, whereas pronounced sex differences are evident in adults. Treatment of newborn rats (days 2--6) with diethystilbestrol or testosterone resulted in a feminization (decrease) of mixed-function oxidation and glucuronidation in adult males. No changes were seen in immature males or females or adult females. This effect appears to be irreversible and is under pituitary-hypothalamic-gonadal control. In addition to the feminization of enzyme activity, neonatal exposure to hormonally active chemicals also feminizes the hepatic response to cadmium in resultant adult animals.

Metals and the liver in Alzheimer's disease. An investigation of hepatic zinc, copper, cadmium, and metallothionein.

Significant alterations of tissue metal levels have been reported in Alzheimer's disease (AD). Because the liver is intimately involved in metabolism and storage of metals, it may provide a useful site for study of these metals in AD. This study compares livers in AD and controls in their concentrations of zinc, copper, cadmium, and metallothionein, a metal-binding protein important in regulation of metal metabolism. Liver tissue was obtained from 17 patients with AD and 17 age- and sex-matched controls within 12 hours of death and stored at -70 degrees C. Neuropathologic confirmation of diagnosis was available in all cases. Liver homogenates (20%) were used for metal analysis by atomic absorption spectroscopy after wet digestion. Cytosolic metallothionein levels were quantitated by the cadmium or silver saturation method. A significant decline in body and liver weight was found in patients with AD, with no significant change in liver protein or DNA concentration. Total hepatic cadmium (P less than .001) and zinc (P less than .030) concentrations were significantly elevated in AD. The Sephadex G75 chromatographic profile was altered in AD with reduction in zinc bound to metallothionein fractions and increased binding to high molecular weight fractions. These data suggest that the metabolism of cadmium and zinc is altered in AD.

Effects of dexamethasone injection on body retention and hepatic distribution of zinc, cadmium and metallothionein in newborn rats.

The liver of 7-day-old rats contains high levels of metallothionein (MT) and zinc, which can be reduced markedly following treatment of neonates with dexamethasone (1 mg/kg, s.c.) twice daily on days 3, 4, 5 and 6 postpartum. Prior treatment with trace amounts of 65Zn and 109Cd did neither alter the basal MT and zinc concentrations nor their response to dexamethasone. The turnover of 65Zn or 109Cd in newborn rats was studied by measuring the whole body retention of the radioisotopes. Between days 3 and 7 postpartum, the normal turnover of 65Zn was much faster than that of 109Cd, and dexamethasone treatment resulted in further decrease of 65Zn retention without significantly altering that of 109Cd. The data indicate that dexamethasone enhanced the excretion of 65Zn without any effect on 109Cd excretion. The dexamethasone treatment resulted in marked reduction in both hepatic Zn and MT levels in newborn rats. Gel filtration on Sephadex G-75 columns of hepatic cytosols isolated from 7-day-old rats showed significant amounts of total Zn and 65Zn bound to MT fraction. Moreover, dexamethasone treatment markedly reduced their binding to the MT fraction suggesting that most of the Zn lost from the liver of dexamethasone-treated animals was from MT. About 95% of 109Cd in the liver cytosol was present in the MT fraction of 109Cd-injected rats and dexamethasone had little effect on the binding of 109Cd to MT fraction despite a marked reduction in the binding of total Zn. These data suggest that unlike in adult rats, injection of dexamethasone results in marked decrease in hepatic levels of Zn and MT in neonatal rats.

Functional modification of indole binding site with indomethacin congeners.

Indomethacin and four congeners were shown by equilibrium dialysis to interfere with the binding of L-tryptophan at the primary indole binding site on defatted human serum albumin. Incubation of albumin with 1-(p-bromoacetamidobenzovl)- and 1-(m-bromoacetamidobenzoyl)-5-methoxy-2-methyl-3-indolylacetic acid functionally modified this site, decreasing the availability of the site for the binding of L-tryptophan. Incubation in the presence of a large excess of L-tryptophan resulted in the partial protection of the site from modification by 1-(m-bromoacetamidobenzoyl)-5-methoxy-2-methyl-3-indolylacetic acid.

Influence of boundary conditions on a one-dimensional ultrasound backscattering model of blood.

A simulation model of one-dimensional (1-D) ultrasound (US) propagation in blood was used to study the relation between the backscattering coefficient and hematocrit. In this model, an ultrasonic plane wave was propagated in plasma normal to randomly placed slabs of constant thickness whose acoustical properties are the same as red blood cells, and the corresponding intensity reflection coefficient was calculated. The simulation results were compared to the 1-D Percus-Yevick (P-Y) theory as presented in the literature. Previous investigators have reported a close agreement over a limited range of simulation parameters between their results and the P-Y theory. However, a more careful investigation using a wider range of parameters has revealed major discrepancies. It is shown that these arise from an inappropriate choice of boundary conditions. By averaging the material properties beyond the boundaries of the simulation, as suggested by earlier theoretical work, the results are now in excellent agreement with the P-Y theory over a wide range of simulation parameters.

Proglucagon-derived peptides in the neuroendocrine system.

Using several novel in vitro culture systems, we have examined the tissue-specific regulation of the proglucagon-derived peptides, at the levels of proglucagon gene expression and pGdp synthesis and secretion. Our studies indicate that proglucagon gene expression in intenstine, hypothalamus and pancreas is under the regulatory control of protein kinase A- but not a protein kinase C-dependent pathway. PKA and PKC stimulate secretion of the intestinal pGdp's, whereas only PKA stimulates secretion of the hypothalamic peptides. Pancreatic glucagon secretion in response to PKA is subject to further modulation by prevailing glucose concentrations. This diversity in intracellular regulation of the pGdp's may account for some of the tissue-specific differences in synthesis and secretion of the pGdp's that we have observed in diabetes and during development.

Assessment of patient dose and image quality for cardiac CT with breast shields.

Breast shielding can reduce dose to the female breast, a radiosensitive organ receiving significant radiation during computed tomography (CT) chest examinations, particularly in cardiac CT, where Electrocardiogram dose modulation currently precludes the use of radial dose modulation to reduce breast dose. However, breast shields may produce artefacts affecting interpretation of coronary arteries. This study explores the dose savings and the effect of breast shields on image quality with torso and CT dose index body phantoms and an organ dose calculator. Change in dose calculated: 53-63 % (female breast), 82-85 % (lung), 79-84 % (oesophagus) and 76-80 % (effective dose) with larger dose reductions at lower kVp. Image quality is preserved when breast shields are placed after the scout no closer than 10 mm from the skin. Therefore, breast shields can be used in cardiac CT to reduce breast dose without compromising image quality. Revised conversion factors for dose length product to effective dose are suggested for cardiac CT without and with breast shields.