Search PubMed⌕ Search

Biomedical subjects

A Moon

Publications and source records attributed to A Moon.

At least 19 recordsLinked to original sources
PubMed2005

Determinants of psychological distress over time among older Korean immigrants and Non-Hispanic White elders: evidence from a two-wave panel study.

The purpose of this study is to examine racial/ethnic differences in the change of psychological distress as measured by CES-D over time and its associated factors between older Korean immigrants and non-Hispanic White elders, based on a social stress perspective. Data come from a two-wave panel survey of 172 older Korean immigrants and 157 non-Hispanic White elders, with a follow-up period of 12 to 15 months. The sample was drawn from a three-stage probability sampling method. Ordinary least square regressions in a hierarchical process and change score method were used to analyze the two-wave panel data. Older Korean immigrants reported higher levels of psychological distress than the non-Hispanic White elderly at both Time 1 and Time 2. Changes in self-assessed health status and functional limitations were significantly associated with change in psychological distress for both ethnic groups. Increased social support significantly decreased psychological distress at Time 2, for older Korean immigrants only. This study discusses practice and policy implications for service and interventions for older immigrants to assist their adjustment to a host society.

Aged↗
PubMed2004

Early prescriptions of antibiotics and the risk of allergic disease in adults: a cohort study.

BACKGROUND: It is frequently asserted that antibiotic prescriptions in childhood are associated with the development of allergic disease, especially asthma. A study was undertaken to establish the direction of this relationship. METHODS: A retrospective cohort study of 746 adults was performed in three general practices. Antibiotic prescriptions in the first 5 years of life, collected from contemporary medical records, were related to self-reports of asthma and hay fever and the results of skin prick testing with common aeroallergens. RESULTS: There was no relationship between early antibiotic prescription and atopy, either for all antibiotic use (OR 1.01) or for antibiotics prescribed at different ages. The significant associations between prescriptions at ages 4 and 5 and hay fever (OR 1.23 and 1.16, respectively) were explained by coexisting asthma. Relationships between antibiotic use and asthma (allergic or otherwise) were statistically significant and strengthened with increasing age of prescription, but were largely confined to antibiotics prescribed for lower respiratory symptoms. CONCLUSIONS: The reported associations between childhood antibiotic use and asthma are most plausibly explained by "reverse causation"--the tendency for prescriptions to be written for the early manifestations of pre-existing asthma.

Adult↗
PubMed2001

Capsaicin-induced apoptosis in SK-Hep-1 hepatocarcinoma cells involves Bcl-2 downregulation and caspase-3 activation.

Hepatocellular carcinoma is one of the most lethal malignancies and there is no effective preventive measure in this highly malignant disease to date. In the present study, we investigated the chemopreventive potential of capsaicin (8-methyl-N- vanillyl-6-nonenamide), the principal pungent ingredient found in hot red pepper, in SK-Hep-1 hepatocellular carcinoma cells. Treatment of capsaicin inhibited growth of SK-Hep-1 cells in a concentration-dependent manner while 4-methoxy capsaicin (Met-capsaicin) was less potent. This inhibitory effect of capsaicin on SK-Hep-1 cell growth was mainly due to the induction of apoptosis as evidenced by DNA fragmentation and nuclear condensation. Furthermore, capsaicin prominently reduced the ratio of anti-apoptotic Bcl-2 to pro-apoptotic Bax and consequently increased caspase-3 activity. These results demonstrate that capsaicin efficiently induced apoptosis in SK-Hep-1 cells through a caspase-3-dependent mechanism, which may contribute to its chemopreventive function.

Anticarcinogenic Agents↗
PubMed2001

Both platelet-derived growth factor receptor (PDGFR)-alpha and PDGFR-beta promote murine fibroblast cell migration.

Cell motility plays a critical role for many physiological and pathological processes including wound healing, fibrosis, angiogenesis, and tumor metastasis. Platelet-derived growth factor (PDGF) is among the most potent stimuli for mesenchymal cell migration. The PDGF B-chain homodimer PDGF BB activates both alpha- and beta-receptor subunits (alpha-PDGFR and beta-PDGFR), and promotes cell migration in many cell types including fibroblasts and smooth muscle cells. PDGF-A chain homodimer PDGF AA activates alpha-PDGFR only, and its role for cell migration is still debatable. PDGF BB, but not PDGF AA, induces smooth muscle cell migration. Interestingly, alpha-PDGFR was shown to antagonize beta-PDGFR-induced smooth muscle cell migration. In the present study, we investigated the role of alpha-PDGFR and beta-PDGFR in PDGF-mediated cell migration of murine fibroblasts (NIH 3T3). Unlike smooth muscle cells, both PDGF AA and PDGF BB promoted NIH 3T3 cell migration. The effect of PDGF BB activation of beta-PDGFR alone for cell migration was examined using previously established NIH 3T3 clones in which alpha-PDGFR signaling is inhibited by a dominant-negative alpha-PDGFR, or an antisense construct of alpha-PDGFR. PDGF BB activation of beta-PDGFR alone was sufficient to induce cell migration, but the efficiency was significantly lower compared to PDGF activation of both receptors. These results showed that both alpha- and beta-PDGFRs promote fibroblast cell migration and their effects are additive. Taken together, we propose that cell-type specific alpha-PDGFR signaling is critical for regulation of mesenchymal cell migration in response to PDGF isoform, whereas beta-PDGFR mainly promotes cell migration.

3T3 Cells↗
PubMed2001

Inhibition of invasion and induction of apoptosis by curcumin in H-ras-transformed MCF10A human breast epithelial cells.

Curcumin, a dietary pigment in turmeric, posseses anti-carcinogenic and anti-metastatic properties. The present study was conducted to study in vitro chemopreventive effects of curcumin in transformed breast cells. Here, we show that curcumin inhibits H-ras-induced invasive phenotype in MCF10A human breast epithelial cells (H-ras MCF10A) and downregulates matrix metalloproteinase (MMP)-2 dose-dependently. Curcumin exerted cytotoxic effect on H-ras MCF10A cells in a concentration-dependent manner. Curcumin-induced cell death was mainly due to apoptosis in which a prominent downregulation of Bcl-2 and upregulation of Bax were involved. We also suggest a possible involvement of caspase-3 in curcumin-induced apoptosis. Curcumin treatment resulted in the production of reactive oxygen species (ROS) in H-ras MCF10A cells. Apoptotic event by curcumin was significantly inhibited by pretreatment of an antioxidant N-acetyl-L-cysteine (NAC), suggesting redox signaling as a mechanism responsible for curcumin-induced apoptosis in H-ras MCF10A cells. Taken together, our results demonstrate that curcumin inhibits invasion and induces apoptosis, proving the chemopreventive potential of curcumin.

Antineoplastic Agents, Phytogenic↗
PubMed2001

Induction of CTL responses and identification of a novel epitope of hepatitis B virus surface antigens in C57BL/6 mice immunized with recombinant vaccinia viruses.

MHC class I-restricted cytotoxic T lymphocyte (CTL) response to hepatitis B virus (HBV) surface antigens (HBsAg) has been suggested to play essential roles in viral clearance and pathogenesis of HBV-induced hepatitis. In the present study, we analyzed CTL responses to endogenously synthesized or exogenously introduced HBsAg in C57BL/6 mice (H-2(b)). We show that the endogenously synthesized surface antigens of adr-type HBV encoded by recombinant vaccinia virus efficiently elicit CTL responses in C57BL/6 mice previously defined as non-responders to vaccinia-HBV immunization. We also show that two peptides, S(179-186) (FVQWFVGL) and S(208-216) (ILSPFLPLL), serve as effective motifs for CTL response in H-2(b) system after in vitro restimulation of the primed T cells with either of the two synthetic peptides. S(208-215) has recently been identified as a CTL epitope which could be produced by exogenous pathway only, in contrast to the current result, while S(179-186) appeared a novel epitope for CTL response. In addition, we show that soluble HBsAg also elicits CTL responses in H-2(b) mice upon in vitro restimulation with the two peptides, although less efficiently compared with the recombinant vaccinia viruses. These findings may provide an efficient experimental system for studying H-2(b)-restricted immune responses against endogenously synthesized and exogenously introduced HBsAg.

Animals↗
PubMed2001

Chemopreventive allylthiopyridazine derivatives induce apoptosis in SK-Hep-1 hepatocarcinoma cells through a caspase-3-dependent mechanism.

Dietary organosulphur compounds including diallylsulphide, a component of garlic oil, were shown to inhibit the proliferation of tumour cells. Since hepatocellular carcinoma is one of the most lethal malignancies and there is no effective preventive measure to date, we wished to pursue the chemopreventive potential of the synthetic allylthiopyridazine derivatives (K compounds) on hepatocarcinoma cells. Here, we report that the K compounds efficiently inhibited SK-Hep-1 cell proliferation through induction of apoptosis. Increased chain length at the 3-position of allylthiopyridazine ring improved the potency of growth inhibition. K compounds downregulated Bcl-2, while Bax remained unchanged, reducing the ratio of Bcl-2 to Bax. We also provide evidence that the K compound-induced apoptosis involves cytochrome c release and caspase-3 activation. These results suggest that the allythiopyridazine derivatives, especially 3-propoxy-6-allylthiopyridazine, induce apoptosis in SK-Hep-1 cells through a caspase-3-dependent mechanism, which may contribute to the chemopreventive function for hepatocellular carcinoma.

Anticarcinogenic Agents↗
PubMed2001

Cyclosporine-Induced neurotoxicity during treatment of Crohn's disease: lack of correlation with previously reported risk factors.

A 13-yr-old boy with severe Crohn's disease was admitted with persistent hematochezia requiring transfusion. Cyclosporine A was begun on hospital day 22 because of continued diarrhea and rectal bleeding despite high doses of i.v. corticosteroids. Six days into cyclosporine therapy, the patient developed multiple episodes of generalized tonic-clonic seizures accompanied with magnetic resonance imaging findings typical, although not pathognomonic, of cyclosporine A central nervous system neurotoxicity. Further investigations demonstrated that severe cyclosporine neurotoxicity may occur in the absence of previously reported clinical risk factors. Experience from the pediatric and adult GI transplant and neurological literature is discussed.

Adolescent↗
PubMed2000

Apicidin, an inhibitor of histone deacetylase, prevents H-ras-induced invasive phenotype.

Cancer metastasis represents the most important cause of cancer death and agents that may inhibit tumor cell invasion have been extensively pursued. In the present study, we have examined the anti-invasive effect of apicidin [cyclo(N-O-methyl-L-tryptophanyl-L-isoleucinyl-D-pipecolinyl -L-2-amin o-8-oxodecanoyl)], a fungal metabolite that was identified as an antiprotozoal agent known to inhibit parasite histone deacetylase (HDAC). We show that apicidin significantly inhibits H-ras-induced invasive phenotype of MCF10A human breast epithelial cells in parallel with a specific downregulation of matrix metalloproteinase (MMP)-2, but not MMP-9. We also show that apicidin induces a morphological reversal and growth inhibition of H-ras MCF10A cells similar to that induced by other HDAC inhibitors. Taken in conjunction with the fact that uncontrolled ras activation is probably the most common genetic defect in human cancer cells, our data showing the anti-invasive and detransforming activities of apicidin in H-ras-transformed MCF10A cells may suggest a potential use of HDAC inhibitors for treatment of cancer.

Breast↗
PubMed2000

H-ras, but not N-ras, induces an invasive phenotype in human breast epithelial cells: a role for MMP-2 in the H-ras-induced invasive phenotype.

Elevated p21ras expression is associated with tumor aggressiveness in breast cancer including the extent of invasion into fat tissues, infiltration into lymphatic vessels and tumor recurrence. In the present study, we have examined the roles of H-ras and N-ras, members of the human ras gene family, in the pathogenesis of breast cancer. We show that H-ras, but not N-ras, induces an invasive phenotype in human breast epithelial cells (MCF10A) as determined by the Matrigel invasion assay, whereas both H-ras and N-ras induce anchorage-independent growth, as shown by soft agar assay. We examined the effects of H-ras and N-ras activation on the expression of MMP-2 and MMP-9, which can degrade type IV collagen, the major structural collagen of the basement membrane. We show that MMP-2 is efficiently induced by H-ras, whereas MMP-9 induction is more prominent in N-ras-activated MCF10A cells. We also show that H-ras-mediated invasiveness is significantly inhibited when the expression of MMP-2 is down-regulated, using an oligodeoxyribonucleotide complementary to the MMP-2 mRNA, or when MMP-2 activity is blocked by its inhibitor TIMP-2 (tissue inhibitors of matrix metalloproteinase-2). Our results show that the H-ras-induced invasive phenotype is associated more closely with the expression of MMP-2 in human breast epithelial cells, rather than the induction of MMP-9 expression, as shown previously for rat embryonic fibroblasts.

Breast Neoplasms↗
PubMed1999

Anti-tumor promoting potential of naturally occurring diarylheptanoids structurally related to curcumin.

In recent years, there have been considerable efforts to search for naturally occurring substances for intervention of carcinogenesis. Many components from medicinal or dietary plants have been identified to possess potential chemopreventive properties. For instance, curcumin, a yellow colouring agent from turmeric (Curcuma longa Linn., Zingiberaceae) has been shown to inhibit tumor formation in diverse animal models. Alpinia oxyphylla Miquel that also belongs to ginger family has been used in oriental herbal medicine. In the present work, we have evaluated the anti-tumor promoting potential of yakuchinone A (1-[4'-hydroxy-3'-methoxyphenyl]-7-phenyl-3-heptanone) and yakuchinone B (1-[4'-hydroxy-3'-methoxyphenyl]-7-phenylhept-1-en-3-one), major pungent ingredients of A. oxyphylla. Thus, topical application of yakuchinone A or B significantly suppressed TPA-induced epidermal ornithine decarboxylase activity. They also reduced TPA-stimulated production of tumor necrosis factor-alpha in cultured human promyelocytic leukemia (HL-60) cells. Both compounds blunted the TPA-induced superoxide generation in differentiated HL-60 cells in a concentration-related manner and also inhibited lipid peroxidation in rat brain homogenates. Furthermore, yakuchinone A and yakuchinone B nullified the activation of the activator protein-1 (AP-1) in immortalized mouse fibroblast cells in culture. These findings indicate that pungent diarylheptanoids from A. oxyphylla have anti-tumor promotional properties that can contribute to their chemopreventive potential.

3T3 Cells↗
PubMed1999

Predictors of use of traditional Korean healers among elderly Koreans in Los Angeles.

Many ethnic groups are known to use traditional healers often in conjunction with Western biomedical medicine, thus combining treatment regimens and medical advice as they see fit. Awareness of the use of traditional healers is an increasingly salient issue due to the growing diversity and aging of the U.S. population. To explore the determinants of use of traditional healers, we studied demographics, health status, and social support networks of a representative sample of elderly Koreans in Los Angeles County, California. The results revealed that chronic conditions such as arthritis, lung disease, and stomach pain, fewer depressive symptoms, availability of health insurance, and stronger social networks were significant predictors of use of traditional healers. Better understanding reasons for and patterns of health care use may enhance the delivery of care to the heterogeneous elderly population by preventing potential treatment complications and increasing health providers' cultural sensitivity.

Aged↗
PubMed1999

A novel cerebroside from lycii fructus preserves the hepatic glutathione redox system in primary cultures of rat hepatocytes.

We previously reported the isolation of a novel cerebroside (1-O-(beta-D-glucopyranosyl)-(2S,3R,4E,8Z)-2-N-palmityloc tadecasphinga-4,8-diene; LCC) from the fruits of Lycium chinense MILL. (Solanaceae) which protected primary cultured rat hepatocytes from the toxicity induced by carbon tetrachloride (CCl4). The present study was conducted to determine the mechanism(s) by which LCC might exert its hepatoprotective activity. To determine the effect of LCC on the glutathione (GSH) redox system, we measured the activities of enzymes involved in the system as well as the levels of hepatic mitochondrial GSH and malondialdehyde (MDA). The hepatotoxicant, CCl4, routinely decreased levels of total and reduced GSH. The levels of these compounds were significantly maintained at the levels of the control cultures following treatment with LCC. The decreased activities of glutathione reductase and glutathione peroxidase in CCl4-injured rat hepatocytes were significantly increased by the treatment of LCC. Furthermore, the elevated levels of MDA seen in CCl4-injured rat hepatocytes were reduced after treatment with LCC in a concentration dependent manner over a range of 1-10 microM. From these results, we postulate that LCC may preserve the hepatic mitochondrial level of GSH by scavenging reactive oxygen species produced during CCl4-induced toxicity and thereby reduce lipid peroxidation and cellular damage.

Animals↗
PubMed1998

Awareness and utilization of community long-term care services by elderly Korean and non-Hispanic white Americans.

This article presents a comparative analysis of the level of awareness and utilization of 15 community-based long-term care services by 213 elderly Korean and 201 non-Hispanic White Americans. We found extremely low levels of awareness and utilization of long-term health and social services among Korean Americans, in both absolute and relative terms. This finding challenges the success of the Older Americans Act, an important funding source of those services, in meeting its stated objectives to increase service availability and delivery to minority elders and socioeconomically disadvantaged elders. Strategies for effective outreach and public education efforts are also discussed.

Aged↗
PubMed1997

Effect of Glycyrrhiza glabra roots and glycyrrhizin on the glucuronidation in rats.

As an approach to elucidate the possible in vivo interaction of synthetic drugs and herbs which are frequently used in combination in Asia, the effect of Glycyrrhiza glabra on the metabolism of acetaminophen (AAP) was examined in male Sprague-Dawley rats. The pretreatment of the methanol extract of Glycyrrhiza glabra roots (Glycyrrhizae Radix, GR, 1 g/kg, p.o.) for 6 days significantly increased the cumulative biliary (156%) and urinary (132%) excretions of AAP-glucuronide conjugate within 120 min after the administration of AAP (150 mg/kg, i.v.) without affecting thioether and sulfate conjugates. These findings suggest that GR might enhance the glucuronidation pathway of AAP. In order to study the effect of GR on the glucuronidation in rat liver, we examined enzymatic activity of p-nitrophenol UDP-glucuronosyltransferase (UGT), which is also called UGT1A, and intracellular concentrations of hepatic UDP-glucuronic acid, upon the administration of GR (1 g/kg, p.o.) or glycyrrhizin (23 mg/kg, p.o.), a major component of GR, for 6 days. GR and glycyrrhizin caused increases in specific activities of UGT1A by 111% and 96%, respectively. Concentration of UDP-glucuronic acid was increased 257% by GR and 484% by glycyrrhizin. These data indicate that GR and glycyrrhizin activated glucuronidation and thus suggest the possibility that GR may influence detoxification of xenobiotics in rat liver. Using the p-nitrophenol UGT1A1 cDNA as a probe, we found that the activation of UGT1A by GR was not due to the induction of mRNAs for the enzyme.

Animals↗
PubMed1995

Allergic gastroenteropathy in children.

OBJECTIVE: To review the pathogenesis, symptoms, and treatment of gastrointestinal disorders linked to immunopathologic reactions associated with the ingestion of food antigens in infancy and childhood. DATA SOURCES: A computerized MEDLINE search was performed for the following topics: allergic colitis, allergic proctitis, eosinophilic gastroenteritis, eosinophilic colitis, cow milk intolerance, protein losing enteropathy, and malabsorption. This search was restricted to the English language and human subjects. Articles published between 1960 and 1993 were included as references. The textbooks which were used as references include: (1) Walker WA, et al, eds. Pediatric gastrointestinal disease; pathophysiology, diagnosis, management, Philadelphia: BC Decker, 1991; (2) Wyllie R, et al, eds. Pediatric gastrointestinal disease; pathophysiology, diagnosis, management, Philadelphia: WB Saunders, 1993; (3) Targan SR, et al, eds. Immunology & immunopathology of liver and gastrointestinal tract. Igaku-Shoin, 1991; (4) Goldman H, et al, eds. Pathology of the gastrointestinal tract. Philadelphia: WB Saunders, 1992. CONCLUSION: The symptoms of allergic gastroenteropathy may be those of classic allergic reactions or present as symptom complexes that may include diarrhea, malabsorption, and protein-losing enteropathy. The immunopathogenesis of allergic gastroenteropathy is complex and is still not clearly understood. As our understanding of the gastrointestinal mucosal system evolves, we should be able to manage and care for the infants and children who suffer from this group of disorders better.

Allergens↗