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1.
J Behav Med ; 43(6): 1026-1040, 2020 12.
Article in English | MEDLINE | ID: mdl-32361793

ABSTRACT

Syndemics, or comorbid and mutually reinforcing psychosocial problems, are associated with increased HIV risk among men who have sex with men (MSM). Although the dynamic interplay among syndemic indicators is theorized to be crucial for increasing risk of HIV acquisition, novel approaches are needed to understand how these syndemic problems interrelate. This study examined the associations between nine self-reported syndemic indicators in 194 MSM at high risk of HIV acquisition. We compared exploratory factor analyses (EFA) to a network analysis. In the present study, network analysis consisted of edges representing bidirectional partial polychoric correlations between nodes, which represent psychosocial syndemic indicators. EFA yielded a 1-factor solution including suicidal ideation (SI), injection drug use (IDU), depression, social anxiety, intimate partner violence, substance use, and sexual compulsivity, and excluded heavy drinking and childhood sexual abuse. Network analysis yielded a pattern of interconnectedness with the most central nodes being SI, IDU, substance use, and depression. Statistically significant relationships (absolute edge weights) were found between SI and depression, social anxiety, and IDU, and IDU and substance use. These results suggest that depression and substance use, especially more severe presentations of these conditions such as SI and IDU, are prominent interconnected components of the HIV syndemic among MSM at high risk for HIV acquisition. SI, IDU, substance use, and depression may indeed be prudent targets of intervention. Future research on the inclusion of these syndemic indicators in analytical models involving interaction terms may be warranted.


Subject(s)
HIV Infections , Sexual and Gender Minorities , Substance-Related Disorders , Child , Factor Analysis, Statistical , Homosexuality, Male , Humans , Male , Sexual Behavior , Substance-Related Disorders/epidemiology , Syndemic , Unsafe Sex
2.
Mol Psychiatry ; 20(11): 1397-405, 2015 Nov.
Article in English | MEDLINE | ID: mdl-25560755

ABSTRACT

Schizophrenia is associated with alterations in working memory that reflect dysfunction of dorsolateral prefrontal cortex (DLPFC) circuitry. Working memory depends on the activity of excitatory pyramidal cells in DLPFC layer 3 and, to a lesser extent, in layer 5. Although many studies have profiled gene expression in DLPFC gray matter in schizophrenia, little is known about cell-type-specific transcript expression in these two populations of pyramidal cells. We hypothesized that interrogating gene expression, specifically in DLPFC layer 3 or 5 pyramidal cells, would reveal new and/or more robust schizophrenia-associated differences that would provide new insights into the nature of pyramidal cell dysfunction in the illness. We also sought to determine the impact of other variables, such as a diagnosis of schizoaffective disorder or medication use at the time of death, on the patterns of gene expression in pyramidal neurons. Individual pyramidal cells in DLPFC layers 3 or 5 were captured by laser microdissection from 36 subjects with schizophrenia or schizoaffective disorder and matched normal comparison subjects. The mRNA from cell collections was subjected to transcriptome profiling by microarray followed by quantitative PCR validation. Expression of genes involved in mitochondrial (MT) or ubiquitin-proteasome system (UPS) functions were markedly downregulated in the patient group (P-values for MT-related and UPS-related pathways were <10(-7) and <10(-5), respectively). MT-related gene alterations were more prominent in layer 3 pyramidal cells, whereas UPS-related gene alterations were more prominent in layer 5 pyramidal cells. Many of these alterations were not present, or found to a lesser degree, in samples of DLPFC gray matter from the same subjects, suggesting that they are pyramidal cell specific. Furthermore, these findings principally reflected alterations in the schizophrenia subjects were not present or present to a lesser degree in the schizoaffective disorder subjects (diagnosis of schizoaffective disorder was the most significant covariate, P<10(-6)) and were not attributable to factors frequently comorbid with schizophrenia. In summary, our findings reveal expression deficits in MT- and UPS-related genes specific to layer 3 and/or layer 5 pyramidal cells in the DLPFC of schizophrenia subjects. These cell type-specific transcriptome signatures are not characteristic of schizoaffective disorder, providing a potential molecular-cellular basis of differences in clinical phenotypes.


Subject(s)
Gene Expression Regulation/physiology , Prefrontal Cortex/pathology , Psychotic Disorders/pathology , Pyramidal Cells/metabolism , Schizophrenia/pathology , Transcriptome/physiology , Adult , Analysis of Variance , Animals , Antipsychotic Agents/pharmacology , Female , Gene Expression Profiling , Gene Expression Regulation/drug effects , Humans , Laser Capture Microdissection , Macaca fascicularis , Male , Middle Aged , Mitochondrial Proteins/genetics , Mitochondrial Proteins/metabolism , Oligonucleotide Array Sequence Analysis , Prefrontal Cortex/drug effects , RNA, Messenger/metabolism , Signal Transduction/drug effects , Signal Transduction/physiology , Ubiquitin/genetics , Ubiquitin/metabolism
3.
Nutr Diabetes ; 1: e6, 2011 May 09.
Article in English | MEDLINE | ID: mdl-23449381

ABSTRACT

BACKGROUND: In the Multiethnic Cohort Study, Japanese Americans (JA) have lower mean body mass index (BMI) compared with Caucasians, but show a higher waist-to-hip ratio at similar BMI values and a greater risk of diabetes and obesity-associated cancers. OBJECTIVE: We investigated the abdominal, visceral and hepatic fat distribution in these Asian and Caucasian Americans. DESIGN: A cross-sectional sample of 60 female cohort participants (30 JA and 30 Caucasians), of ages 60-65 years and BMIs 18.5-40 kg m(-2), underwent anthropometric measurements and a whole-body dual energy X-ray absorptiometry (DXA) scan: a subset of 48 women also had abdominal magnetic resonance imaging (MRI). RESULTS: By design, JA women had similar BMIs (mean 26.5 kg m(-2)) to Caucasian women (27.1 kg m(-2)). JA women were found to have a significantly smaller hip circumference (96.9 vs 103.6 cm; P=0.007) but not a significantly lower DXA total fat mass (25.5 vs 28.8 kg; P=0.16). After adjusting for age and DXA total fat mass, JA women had a greater waist-to-hip ratio (0.97 vs 0.89; P<0.0001), DXA trunk fat (15.4 vs 13.9 kg; P=0.0004) and MRI % abdominal visceral fat (23.9 vs 18.5%; P=0.01) and a lower DXA leg fat mass (8.2 vs 10.0 kg; P=<.0001). Their MRI % subcutaneous fat (33.4 vs 30.2%; P=0.21) and % liver fat (5.8 vs 3.8%; P=0.06) did not significantly differ from that of Caucasian women. CONCLUSIONS: Our findings build on limited past evidence, suggesting that Asian women carry greater abdominal and visceral fat when compared with Caucasian women with similar overall adiposity. This may contribute to their elevated metabolic risk for obesity-related diseases.

4.
Lett Appl Microbiol ; 41(1): 45-51, 2005.
Article in English | MEDLINE | ID: mdl-15960751

ABSTRACT

AIM: To test combined polymerase chain reaction amplification of 16S rRNA gene sequences and denaturing gradient gel electrophoresis (PCR/DGGE) as an analytical method to investigate the composition of the large bowel microbiota of mice during the development of colitis. METHODS AND RESULTS: The colonic microbiota of formerly germfree interleukin 10 (IL-10)-deficient mice that had been exposed to the faecal microbiota of specific pathogen-free animals was screened using PCR/DGGE. The composition of the large bowel microbiota of IL-10-deficient mice changed as colitis progressed. DNA fragments originating from four bacterial populations ('Bacteroides sp.', Bifidobacterium animalis, Clostridium cocleatum, enterococci) were more apparent in PCR/DGGE profiles of colitic mice relative to non-colitic animals, whereas two populations were less apparent (Eubacterium ventriosum, Acidophilus group lactobacilli). Specific DNA:RNA dot blot analysis showed that bifidobacterial ribosomal RNA (rRNA) abundance increased as colitis developed. CONCLUSIONS: PCR/DGGE was shown to be an effective method to demonstrate changes in the composition of the large bowel microbiota of mice in relation to progression of inflammatory disease. The intensity of staining of DNA fragments in DGGE profiles reflected increased abundance of bifidobacterial rRNA in the microbiota of colitic animals. As bifidobacterial fragments in PCR/DGGE profiles generated from microbiota DNA showed increased intensity of fragment staining, an increase in bifidobacterial numbers in colitic mice was indicated. SIGNIFICANCE AND IMPACT OF THE STUDY: PCR/DGGE analysis demonstrated an altered composition of the large bowel microbiota of colitic mice. This work will allow specific groups of bacteria to be targeted in future research concerning the pathogenesis of colitis.


Subject(s)
Colitis/microbiology , Gram-Positive Bacteria/isolation & purification , Intestine, Large/microbiology , Animals , Bacteroides/genetics , Bacteroides/isolation & purification , Bifidobacterium/genetics , Bifidobacterium/isolation & purification , Chronic Disease , Colitis/immunology , Electrophoresis, Polyacrylamide Gel , Gram-Positive Bacteria/genetics , Immunoblotting , Interleukin-10/deficiency , Mice , Mice, Knockout , Polymerase Chain Reaction , RNA, Ribosomal/analysis
5.
Transplant Proc ; 37(10): 4153-8, 2005 Dec.
Article in English | MEDLINE | ID: mdl-16387067

ABSTRACT

Fewer ethnic minorities, especially Asian-Americans, become organ donors. There are cultural, religious, and personal barriers to becoming a designated organ donor. Factors that promote or inhibit organ donation in Asians, especially Filipinos, are not well understood. We conducted a series of focus groups to identify barriers and facilitators to organ donation (deceased donor) among Filipinos. Six focus groups were conducted with church members, adolescents, nurses, physicians, organ recipients, and organ donor families. The mean age of adult participants (n = 57) was 52.3 +/- 15 years, 83% were Catholic, and 72% were female. A qualitative theme analysis methodology identified dominant themes related to organ donation in the participants. The major themes were: awareness of organ donation (38%), family beliefs (25%), religion/spirituality (10%), attitude/emotions (10%), personal experience with organ donation (8%), health profession (6%), and cultural issues (3%). Seventy-five percent of the comments about awareness reflected a positive awareness of cultural issues regarding organ donation, and the rest reflected a lack of awareness or misconceptions. Almost every theme was mentioned in all six focus groups. Understanding a specific ethnic group's knowledge, attitudes, and cultural beliefs regarding organ donation is important in the development of educational campaigns to encourage organ donation in ethnic minority populations.


Subject(s)
Ethnicity , Health Knowledge, Attitudes, Practice , Tissue Donors/psychology , Tissue and Organ Harvesting/methods , Adolescent , Asian/psychology , Asian People , Cadaver , Demography , Humans , Middle Aged , Philippines
6.
AIDS Care ; 14(6): 827-37, 2002 Dec.
Article in English | MEDLINE | ID: mdl-12511215

ABSTRACT

This article describes the development of a safer sex algorithm, which considers the characteristics of a woman's relationship and the HIV risk profile of herself and her primary partner. A sample of 306 low-income, predominantly African American women was recruited to participate in a study of the effectiveness of a sexual health seminar. These women were interviewed three times, at one month prior to seminar administration, three months after the seminar and again nine months after the seminar. Data from these women indicate that using an algorithm that considers the probability of HIV transmission between partners decreases the measured prevalence of unsafe sex in this population by about 17% and lowers the estimate of the average number of unsafe incidents by about four incidents in three months. The algorithm results in measures with adequate levels of temporal stability, which are similar to the more commonly used measure, vaginal or anal intercourse without a condom.


Subject(s)
Algorithms , HIV Infections/prevention & control , Safe Sex/psychology , Sexual Partners/psychology , Adolescent , Adult , Aged , Female , HIV Infections/epidemiology , HIV Infections/transmission , Humans , Interpersonal Relations , Middle Aged , Risk Assessment , Risk-Taking
7.
Exp Mol Pathol ; 71(1): 34-9, 2001 Aug.
Article in English | MEDLINE | ID: mdl-11502095

ABSTRACT

Previously, it had been shown that acute choline deficiency (CD) induced apoptosis in cultured rat liver epithelial cells, whereas cells that are adapted to survive in low-choline-containing medium acquire resistance to CD apoptosis and undergo malignant transformation. Thus, understanding the mechanisms of action of CD could increase our understanding of the role of choline, an essential nutrient, in the process of malignant transformation. The present experiments were designed to test the hypothesis that CD might function as a pro-apoptotic trigger by altering the localization of connexin 43 gap junction protein and gap junctional intercellular communication (GJIC). Established liver epithelial cells (WB cells; Hep3B cells) were maintained in a defined, serum-free medium control (70 microM choline) or choline deficient medium (CD, 5 microM choline) and the localization of connexin 43 protein (Cx43) was studied by immunocytochemistry and Western blotting. In nontumorigenic WB cells, CD apoptosis was associated with retention of Cx43 in the golgi/ER region of the cytoplasm and decreased GJIC as measured using a preloading fluorescent dye transfer method (calcein AM/DiIC(18)). Cells maintained in CD in the presence of 8-bromoadenosine 3':5'-cyclic monophosphate exhibited restoration of Cx43 at the plasma membrane and increased GJIC and inhibition of apoptosis. These studies show that CD apoptosis in nontumorigenic liver epithelial cells is associated with alterations to Cx43 and GJIC and that an uncoupling of Cx43 localization and GJIC is related to resistance to CD apoptosis in transformed liver epithelial cells.


Subject(s)
Apoptosis/physiology , Choline Deficiency/physiopathology , Connexin 43/metabolism , Cyclic AMP/physiology , Gap Junctions/physiology , Hepatocytes/cytology , Hepatocytes/physiology , Liver/cytology , Liver/physiology , 8-Bromo Cyclic Adenosine Monophosphate/pharmacology , Animals , Apoptosis/drug effects , Cell Communication/drug effects , Cell Communication/physiology , Cell Line , Endoplasmic Reticulum/physiology , Epithelial Cells/cytology , Epithelial Cells/drug effects , Epithelial Cells/physiology , Gap Junctions/drug effects , Gap Junctions/ultrastructure , Golgi Apparatus/physiology , Hepatocytes/drug effects , Immunohistochemistry , Rats
8.
Dev Neurosci ; 23(2): 100-6, 2001.
Article in English | MEDLINE | ID: mdl-11509832

ABSTRACT

Previously we have shown that changes in maternal dietary choline are associated with permanent behavioral changes in offspring. Importantly, in adult male rats, feeding a choline-deficient diet increases the localization of cyclin-dependent kinase inhibitors (CDKIs) in the liver, whereas young adult CDKI knockout mice (p15Ink4B or p27Kip1) exhibit behavioral abnormalities. Thus, maternal dietary choline-CDKI interactions could underlie the changes we observe in fetal hippocampal development and cognitive function in offspring. Here, timed-pregnant rats on embryonic day E12 were fed the AIN-76 diet with varying levels of dietary choline for 6 days, and, on E18, fetal brain sections were collected, and the localization of CDKI proteins was studied using immunohistochemistry and an unbiased image analysis method. In choline-supplemented animals compared to controls, the number of cells with nuclear immunoreactivity for p15Ink4b CDKI protein was decreased 2- to 3-fold in neuroepithelial ventricular zones and adjacent subventricular zones corresponding to the fimbria, primordial dentate gyrus and Ammon's horn regions in the fetal hippocampus. In contrast, maternal dietary choline deficiency significantly decreased nuclear p15Ink4b immunoreactivity in the neuroepithelial layer of the dentate gyrus. Unlike p15Ink4b, the CDKI protein p27Kip1 was observed almost exclusively in the cytoplasm, though the protein was distributed throughout the proliferating and postmitotic zones in the E18 fetal hippocampus. Maternal dietary choline supplementation decreased the cytoplasmic staining intensity for p27Kip1 throughout the fetal hippocampus compared to control animals. Choline deficiency increased the staining intensity of p27Kip1 throughout the hippocampus in association with increased expression of MAP-1 and vimentin proteins. These results link maternal dietary choline availability to CDKI protein immunoreactivity and commitment to differentiation during fetal hippocampal development.


Subject(s)
Cell Cycle Proteins/analysis , Choline/pharmacology , Cyclin-Dependent Kinase Inhibitor p16/analysis , Dentate Gyrus/chemistry , Dentate Gyrus/embryology , Tumor Suppressor Proteins/analysis , Animal Nutritional Physiological Phenomena , Animals , Cyclin-Dependent Kinase Inhibitor p15 , Cyclin-Dependent Kinase Inhibitor p27 , Female , Memory , Microtubule-Associated Proteins/analysis , Pregnancy , Rats , Rats, Sprague-Dawley , Vimentin/analysis
9.
FASEB J ; 15(10): 1739-44, 2001 Aug.
Article in English | MEDLINE | ID: mdl-11481221

ABSTRACT

The mechanism of induction of apoptosis by the novel anti-cancer drug 1-O-octadecyl-2-methyl-rac-glycero-3-phosphocholine (ET-18-OCH3) was investigated in p53-defective SV40 immortalized rat hepatocytes (CWSV1). Exposure to 12 microM ET-18-OCH3 for 36 h induced apoptosis as determined using classical morphological features and agarose gel electrophoresis of genomic DNA. Increased levels of reactive oxygen species (ROS) were detected spectrophotometrically using a nitroblue tetrazolium (NBT) assay in cells treated with ET-18-OCH3. Both the increased generation of ROS and the induction of apoptosis were inhibited when cells were treated concurrently with ET-18-OCH3 in the presence of the antioxidant alpha-tocopherol. Similar results were achieved when cells were switched acutely to choline-deficient (CD) medium in the presence of the antioxidant. The possible role of mitochondria in the generation of ROS was investigated. Both ET-18-OCH3 and CD decreased the phosphatidylcholine (PC) content of mitochondrial and associated membranes, which correlated with depolarization of the mitochondrial membrane as analyzed using 5,5',6,6'-tetramethylbenzimidazolcarbocyanine iodide (JC-1), a sensitive probe of mitochondrial membrane potential. Rotenone, an inhibitor of the mitochondrial electron transport chain, significantly reduced the intracellular level of ROS and prevented mitochondrial membrane depolarization, correlating with a reduction of apoptosis in response to either ET-18-OCH3 or CD. Taken together, these results suggest that the form of p53-independent apoptosis induced by ET-18-OCH3 is mediated by alterations in mitochondrial membrane PC, a loss of mitochondrial membrane potential, and the release of ROS, resulting in completion of apoptosis.


Subject(s)
Apoptosis/drug effects , Hepatocytes/physiology , Mitochondria, Liver/physiology , Phospholipid Ethers/pharmacology , Reactive Oxygen Species/metabolism , Tumor Suppressor Protein p53/physiology , Animals , Antigens, Polyomavirus Transforming/pharmacology , Antioxidants/pharmacology , Cell Line, Transformed , Electrophoresis, Agar Gel , Hepatocytes/ultrastructure , Intracellular Membranes/chemistry , Intracellular Membranes/physiology , Male , Membrane Potentials , Mitochondria, Liver/chemistry , Mitochondria, Liver/ultrastructure , Nitroblue Tetrazolium , Phosphatidylcholines/analysis , Rats , Rats, Inbred F344 , Tumor Suppressor Protein p53/antagonists & inhibitors , Vitamin E/pharmacology
10.
Carcinogenesis ; 22(8): 1257-69, 2001 Aug.
Article in English | MEDLINE | ID: mdl-11470757

ABSTRACT

Cell cycle checkpoints are barriers to carcinogenesis as they function to maintain genomic integrity. Attenuation or ablation of checkpoint function may enhance tumor formation by permitting outgrowth of unstable cells with damaged DNA. To examine the function of cell cycle checkpoints in rat hepatocarcinogenesis, we analyzed the responses of the G (1), G (2) and mitotic spindle assembly checkpoints in normal rat hepatocytes, hepatic epithelial stem-like cells (WB-F344) and transformed derivatives of both. Normal rat hepatocytes (NRH) displayed a 73% reduction in the fraction of nuclei in early S-phase 6-8 h following 8 Gy of ionizing radiation (IR) as a quantitative measure of G (1) checkpoint function. Chemically and virally transformed hepatocyte lines displayed significant attenuation of G (1) checkpoint function, ranging from partial to complete ablation. WB-F344 rat hepatic epithelial cell lines at low, mid and high passage levels expressed G (1) checkpoint function comparable with NRH. Only one of four malignantly transformed WB-F344 cell lines displayed significant attenuation of G (1) checkpoint function. Attenuation of G (1) checkpoint function in transformed hepatocytes and WB-F344 cells was associated with alterations in p53, ablated/attenuated induction of p21 (Waf1) by IR, as well as aberrant function of the spindle assembly checkpoint. NRH displayed 93% inhibition of mitosis 2 h after 1 Gy IR as a quantitative measure of G (2) checkpoint function. All transformed hepatocyte and WB-F344 cell lines displayed significant attenuation of the G (2) checkpoint. Moreover, the parental WB-F344 line displayed significant age-related attenuation of G (2) checkpoint function. Abnormalities in the function of cell cycle checkpoints were detected in transformed hepatocytes and WB-F344 cells at stages of hepatocarcinogenesis preceding tumorigenicity, sustaining a hypothesis that aberrant checkpoint function contributes to carcinogenesis.


Subject(s)
Cell Cycle , Hepatocytes/cytology , Liver/cytology , Animals , Base Sequence , Cell Line, Transformed , Cyclin-Dependent Kinase Inhibitor p21 , Cyclins/biosynthesis , DNA Primers , Epithelial Cells/cytology , Epithelial Cells/metabolism , Hepatocytes/metabolism , Liver/metabolism , Male , Polymorphism, Single-Stranded Conformational , Rats , Rats, Inbred F344 , Spindle Apparatus , Tumor Suppressor Protein p53/genetics
11.
Exp Mol Pathol ; 70(2): 71-6, 2001 Apr.
Article in English | MEDLINE | ID: mdl-11263949

ABSTRACT

We investigated the possible role of the estrogen-regulated protein lactoferrin (Lf) in the response of isolated normal human endometrial epithelial cells (NHEC) and established human endometrial carcinoma (EC) cell lines to tamoxifen (TAM). Using confocal laser scanning microscopy and a monospecific antibody, Lf was localized to the cytoplasm of normal and EC cells. Antibody neutralization of secreted Lf inhibited, whereas exogenous Lf (0--100 microg/ml) enhanced, cell proliferation in both classes of cells. Treatment of NHEC with TAM inhibited cell growth via a protein kinase-C-mediated pathway, concomitant with a reduction in the staining intensity for Lf. Importantly, in EC cells, TAM greatly enhanced the staining intensity for Lf, but did not affect cell growth. We propose that stable expression of Lf protein by EC cells may impart a survival advantage to these cells, which may, in part, account for the resistance of these cells to tamoxifen.


Subject(s)
Anticarcinogenic Agents/pharmacology , Endometrial Neoplasms/metabolism , Endometrium/drug effects , Lactoferrin/physiology , Tamoxifen/pharmacology , Animals , Blotting, Western , Cell Division/drug effects , Cell Survival/drug effects , Cells, Cultured , Drug Resistance , Endometrial Neoplasms/pathology , Endometrium/cytology , Enzyme Inhibitors/pharmacology , Female , Humans , Lactoferrin/drug effects , Lactoferrin/immunology , Microscopy, Confocal , Neutralization Tests , Protein Kinase C/metabolism , Rabbits , Staurosporine/pharmacology , Tumor Cells, Cultured
12.
Gastroenterology ; 120(4): 900-13, 2001 Mar.
Article in English | MEDLINE | ID: mdl-11231944

ABSTRACT

BACKGROUND & AIMS: Normal resident bacteria are required for development of colitis in several rodent models. We determined whether bacterial stimulation is necessary for both induction and perpetuation of mucosal inflammation and T-cell activation in Tg(epsilon26) mice, in which transplantation of wild-type bone marrow (BM-->Tg(epsilon26)) causes colitis under specific pathogen-free (SPF) conditions. METHODS: BM from (C57BL/6 X CBA/J) F1 mice was transplanted into germfree (GF) or SPF Tg(epsilon26) mice. Mesenteric lymph node (MLN) cells from these mice were then transferred into SPF or GF recipients. Colitis and activation of MLN cells were measured by histologic scores, membrane marker analysis, and intracellular cytokine staining. Cytokine secretion by MLN cells stimulated by anti-CD3 or by luminal or epithelial antigens was measured by ELISA. RESULTS: Colitis did not develop when BM was transferred into GF recipient mice (BM-->GF Tg(epsilon26)). T lymphocytes that secreted interferon gamma upon activation were present in the MLN of BM-->GF Tg(epsilon26) mice, albeit in lower frequency than in control BM-->SPF Tg(epsilon26) mice. Furthermore, transfer of MLN cells from BM-->SPF Tg(epsilon26) mice into SPF Tg(epsilon26) recipients induced active colitis, but not if the same cells were transferred into GF Tg(epsilon26) recipients. Although CD4 T cells were detected in the colonic mucosa of GF recipients, no inflammation was observed for at least 31 weeks. In a reciprocal experiment, MLN cells from BM-->GF Tg(epsilon26) mice without colitis transferred disease to SPF Tg(epsilon26) recipients within 2-4 weeks. CONCLUSIONS: Activated T cells are present in the mucosa of BM-->GF Tg(epsilon26) mice but are incapable of inducing disease unless colonic bacteria are present. Moreover, pathogenic T cells require the continuous presence of colonic bacteria to sustain colitis.


Subject(s)
Bacterial Physiological Phenomena , Colitis/microbiology , Colon/microbiology , Animals , Bone Marrow Transplantation , Colitis/pathology , Colitis/prevention & control , Colon/pathology , Germ-Free Life , Immunocompetence/physiology , Intestinal Mucosa/cytology , Lymph Nodes/cytology , Mesentery , Mice , Mice, Inbred C57BL , Mice, Inbred CBA , Phenotype , T-Lymphocytes/physiology , T-Lymphocytes/transplantation , Wasting Syndrome/prevention & control
13.
J Biol Chem ; 276(24): 21670-7, 2001 Jun 15.
Article in English | MEDLINE | ID: mdl-11274158

ABSTRACT

The BAR adaptor proteins encoded by the RVS167 and RVS161 genes from Saccharomyces cerevisiae form a complex that regulates actin, endocytosis, and viability following starvation or osmotic stress. In this study, we identified a human homolog of RVS161, termed BIN3 (bridging integrator-3), and a Schizosaccharomyces pombe homolog of RVS161, termed hob3+ (homolog of Bin3). In human tissues, the BIN3 gene was expressed ubiquitously except for brain. S. pombe cells lacking Hob3p were often multinucleate and characterized by increased amounts of calcofluor-stained material and mislocalized F-actin. For example, while wild-type cells localized F-actin to cell ends during interphase, hob3Delta mutants had F-actin patches distributed randomly around the cell. In addition, medial F-actin rings were rarely found in hob3Delta mutants. Notably, in contrast to S. cerevisiae rvs161Delta mutants, hob3Delta mutants showed no measurable defects in endocytosis or response to osmotic stress, yet hob3+ complemented the osmosensitivity of a rvs161Delta mutant. BIN3 failed to rescue the osmosensitivity of rvs161Delta, but the actin localization defects of hob3Delta mutants were completely rescued by BIN3 and partially rescued by RVS161. These findings suggest that hob3+ and BIN3 regulate F-actin localization, like RVS161, but that other roles for this gene have diverged somewhat during evolution.


Subject(s)
Actins/metabolism , Cytoskeletal Proteins , Fungal Proteins/genetics , Microfilament Proteins/genetics , Microfilament Proteins/metabolism , Saccharomyces cerevisiae Proteins , Schizosaccharomyces/genetics , Transcription, Genetic , Actins/analysis , Amino Acid Sequence , Brain/metabolism , Cell Line , DNA, Complementary , Fungal Proteins/chemistry , Gene Library , Genetic Complementation Test , Humans , Kinetics , Microfilament Proteins/chemistry , Molecular Sequence Data , Organ Specificity , RNA, Messenger/genetics , Schizosaccharomyces/growth & development , Schizosaccharomyces/metabolism , Sequence Alignment , Sequence Deletion , Sequence Homology, Amino Acid
14.
Genetics ; 155(2): 611-22, 2000 Jun.
Article in English | MEDLINE | ID: mdl-10835385

ABSTRACT

The Rheb GTPase is most similar in primary sequence to the Ras, Rap, R-Ras, and Ral GTPases, which regulate cell growth and differentiation in many cell types. A likely fission yeast homologue of mammalian Rheb, which we designated Rhb1, was identified by genome sequencing. Our investigation of rhb1 showed that rhb1(-) cells arrested cell growth and division with a terminal phenotype similar to that of nitrogen-starved cells. In particular, cells depleted of Rhb1 arrested as small, round cells with 1N DNA content, arrested more quickly in low-nitrogen medium, and induced expression of fnx1 and mei2 mRNA, two mRNAs that were normally induced by nitrogen starvation. Since mammalian Rheb binds and may regulate Raf-1, a Ras effector, we tested for functional overlap between Ras1 and Rhb1 in fission yeast. This analysis showed that Ras1 overexpression did not suppress rhb1(-) mutant phenotypes, Rhb1 overexpression did not suppress ras1(-) mutant phenotypes, and ras1(-) rhb1(-) double mutants had phenotypes equal to the sum of the corresponding single-mutant phenotypes. Hence, there is no evidence for overlapping functions between Ras1 and Rhb1. On the basis of this study, we hypothesize that Rhb1 negatively regulates entry into stationary phase when extracellular nitrogen levels are adequate for growth. If this hypothesis is correct, then Rhb1 and Ras1 regulate alternative responses to limiting nutrients.


Subject(s)
Cell Division/genetics , GTP Phosphohydrolases/genetics , Growth Substances , Nitrogen/deficiency , Schizosaccharomyces pombe Proteins , Schizosaccharomyces/genetics , Amino Acid Sequence , Cyclic AMP/metabolism , GTP Phosphohydrolases/chemistry , Molecular Sequence Data , Mutation , Phenotype , Schizosaccharomyces/cytology , Sequence Homology, Amino Acid
15.
J Biol Chem ; 275(19): 14381-7, 2000 May 12.
Article in English | MEDLINE | ID: mdl-10799520

ABSTRACT

Cytokinesis and septation in the fission yeast Schizosaccharomyces pombe are studied as a model for mammalian cell division. In fission yeast, septation is positively regulated by Spg1, a Ras family GTPase that localizes to spindle-pole bodies (SPBs) throughout the cell cycle. As cells enter mitosis, Spg1 accumulates in an active, GTP-bound form and binds the Cdc7 protein kinase to cause Cdc7 translocation to SPBs. Cdc7 disappears from one SPB in mid-anaphase and from the second SPB in late mitosis. Byr4 plus Cdc16 negatively regulate septation by forming a two-component GTPase-activating protein for Spg1. These results led us to hypothesize that Byr4 localization to SPBs regulated the nucleotide state of Spg1, due to its ability to form Spg1GAP activity with Cdc16 and thus the binding of Cdc7 to Spg1 at SPBs. To test this hypothesis, Byr4 localization was determined using indirect immunofluorescence. This analysis revealed that Byr4 was localized to SPBs that did not contain Cdc7. In byr4(-) mutants, Cdc7 localized to interphase SPBs and only symmetrically localized to mitotic SPBs. In contrast, Byr4 overexpression prevented Spg1 and Cdc7 localization to SPBs. These results suggest that Byr4 localization to SPBs maintains Spg1 in an inactive form, presumably by stimulating Spg1 GTPase activity with Cdc16, and that loss of Byr4 from mitotic SPBs increases the active fraction of Spg1 and thereby increases Spg1-Cdc7 binding. Byr4 localization to SPBs was decreased in spg1, cdc16, sid4, and cdc11 mutants as well as in several mutants that affect medial F-actin structures, suggesting that multiple pathways regulate Byr4 localization to SPBs.


Subject(s)
Cell Cycle Proteins/metabolism , Cell Cycle , Fungal Proteins/metabolism , Protein Serine-Threonine Kinases/metabolism , Repressor Proteins , Schizosaccharomyces pombe Proteins , Schizosaccharomyces/metabolism , Spindle Apparatus/metabolism , Fluorescent Antibody Technique, Indirect , Fungal Proteins/genetics , Mutation , Schizosaccharomyces/enzymology
16.
Carcinogenesis ; 21(5): 909-14, 2000 May.
Article in English | MEDLINE | ID: mdl-10783311

ABSTRACT

Apoptosis, or regulated cell suicide, eliminates unwanted and damaged cells, including precancerous and cancerous cells. Since reactive oxygen species (ROS) act as essential apoptotic mediators, we reasoned that increasing the ROS level might enhance apoptosis and thereby slow down tumor growth. Here, using a defined transgenic brain tumor model with known tumor apoptosis rates, we test the impact of antioxidant-depleted diet, capable of increasing ROS levels, or antioxidant-enriched diets on tumor growth. Dramatically increased apoptosis occurs within tumors, but not in normal tissues of antioxidant-depleted mice. The presence of detectable increased oxidant stress within tumors indicates that the likely mechanism of enhanced tumor apoptosis is via ROS and DNA oxidative impairment. Importantly, due to the ROS-enhanced apoptosis, tumor growth is inhibited in mice fed an antioxidant-depleted diet. In clear contrast, an antioxidant-rich diet had no impact on tumor growth.


Subject(s)
Antioxidants/administration & dosage , Apoptosis , Brain Neoplasms/pathology , Diet , Animals , Brain Neoplasms/metabolism , Cell Division , Mice , Mice, Transgenic , Oxidative Stress , Reactive Oxygen Species
17.
Am J Prev Med ; 18(3): 225-34, 2000 Apr.
Article in English | MEDLINE | ID: mdl-10722989

ABSTRACT

INTRODUCTION: The Activity Counseling Trial (ACT) was designed to compare the effectiveness of physician advice alone with physician advice plus behavioral counseling, provided by ACT-trained health educators, to increase levels of physical activity in healthy, sedentary patients. The objective was to determine health care providers' adherence to the ACT protocol for delivering initial "physician" advice on physical activity and to determine providers' satisfaction with the protocol. METHODS: Fifty-four physicians or physician assistants from 11 primary care practices located in California, Texas, and Tennessee volunteered to participate as ACT-trained physicians. Providers were trained to integrate 3 to 4 minutes of initial physical activity advice into the routine office visits of sedentary patients, aged 35 to 75 years, with no acute or serious chronic conditions. This advice included assessment of current physical activities, advising the patient about an appropriate physical activity goal, and referring the patient to the health educator. Providers initialed forms to document delivery of advice, and ACT health educators recorded their advice on a computerized tracking system. A provider survey measured length of time spent advising patients about physical activity and provider satisfaction with the program. RESULTS: Ninety-nine percent of patients received the initial physician advice about physical activity. Eighty-three percent of the providers spent less than 5 to 6 minutes, and 46% spent the recommended 3 to 4 minutes providing advice. Sixty-three percent said the advice resulted in little or no increase in the length of an office visit, and 83% said participation was an asset to their clinics. CONCLUSIONS: Providers incorporated brief physical activity advice into routine primary care visits with little disruption. Their response to the ACT advice protocol was positive and participation in the study was viewed as beneficial.


Subject(s)
Exercise , Health Promotion , Patient Education as Topic , Adult , Aged , Attitude of Health Personnel , Behavior Therapy , Female , Humans , Life Style , Male , Middle Aged , Patient Compliance , Primary Health Care , Treatment Outcome , United States
18.
Prev Med ; 29(4): 277-86, 1999 Oct.
Article in English | MEDLINE | ID: mdl-10547053

ABSTRACT

BACKGROUND: Special challenges are encountered when clinical trial recruitment targets a physician practice-based population, as opposed to recruiting from the community. Since most published information about recruitment has focused on the latter group, summation of successful primary-care-based recruitment strategies could prove useful for future trials recruiting from this population. METHODS: The Activity Counseling Trial (ACT) is a multicenter, randomized clinical trial that evaluated approaches to primary care-based interventions to increase physical activity in sedentary adults 35-75 years of age. Fifty-four clinicians from eight practices recruited 874 participants from three U.S. sites. Recruitment challenges that related, in great part, to the primary care setting included: (1) focusing on patients from ACT physician practices who had regularly scheduled or intend-to-schedule appointments within the next year; (2) placing trial staff in the clinical offices for recruitment purposes; and (3) placing trial interventionists in the physicians' offices. Other challenges were related to recruitment of minorities and men. RESULTS: Patient mailing yielded 43.4% of all randomized participants, followed by office-based questionnaires (32.5%) and direct telephone contact (21.6%). Based on a retrospective cost-effective analysis (indirect costs excluded), the self-administered office-based questionnaire was the least costly strategy for one site ($14/randomized participant), followed by patient mailing at another site ($58). The direct telephone contact method utilized at one site serving primarily a minority population yielded a per randomized participant cost of $80. CONCLUSIONS: Recruitment of clinical trial participants from practice-based populations requires modification of the strategies used to recruit from the community. Multiple strategies should be employed, followed closely for their respective yields, and adapted as needed.


Subject(s)
Correspondence as Topic , Exercise , Family Practice , Multicenter Studies as Topic , Patient Selection , Randomized Controlled Trials as Topic , Surveys and Questionnaires , Telephone , Adult , Aged , Cost-Benefit Analysis , Counseling , Female , Humans , Male , Middle Aged , Office Visits , Retrospective Studies , Surveys and Questionnaires/economics , Telephone/economics
19.
Ann Intern Med ; 131(4): 237-46, 1999 Aug 17.
Article in English | MEDLINE | ID: mdl-10454944

ABSTRACT

BACKGROUND: Educational methods that encourage physicians to adopt practice guidelines are needed. OBJECTIVE: To evaluate an educational strategy to increase neurologists' adherence to specialty society-endorsed practice recommendations. DESIGN: Randomized, controlled trial. SETTING: Six urban regions in New York State. PARTICIPANTS: 417 neurologists. INTERVENTION: The educational strategy promoted six recommendations for evaluation and management of dementia. It included a mailed American Academy of Neurology continuing medical education course, practice-based tools, an interactive evidence-based American Academy of Neurology-sponsored seminar led by local opinion leaders, and follow-up mailings. MEASUREMENTS: Neurologists' adherence to guidelines was measured by using detailed clinical scenarios mailed to a baseline group 3 months before the intervention and to intervention and control groups 6 months after the intervention. In one region, patients' medical records were reviewed to determine concordance between neurologists' scenario responses and their actual care. RESULTS: Compared with neurologists in the baseline and control groups, neurologists in the intervention group were more adherent to three of the six recommendations: neuroimaging for patients with dementia only when certain criteria are present (odds ratio, 4.1 [95% CI, 1.9 to 8.9]), referral of all patients with dementia and their families to the Alzheimer's Association (odds ratio, 2.8 [CI, 1.7 to 4.8]), and encouragement of all patients and their families to enroll in the Alzheimer's Association Safe Return Program (odds ratio, 10.8 [CI, 3.5 to 33.2]). For the other three recommendations, adherence did not differ between the intervention and the nonintervention groups. Agreement between scenario responses and actual care ranged from 27% to 99% for the six recommendations and was 95% or more for three of the recommendations. CONCLUSION: A multifaceted educational program can improve physician adoption of practice guidelines.


Subject(s)
Dementia/prevention & control , Educational Technology , Guideline Adherence , Neurology/education , Practice Guidelines as Topic , Education , Education, Medical, Continuing , Evidence-Based Medicine , Humans
20.
Brain Res Dev Brain Res ; 115(2): 123-9, 1999 Jun 02.
Article in English | MEDLINE | ID: mdl-10407130

ABSTRACT

Maternal changes in dietary choline availability alter brain biochemistry and hippocampal development in the offspring resulting in lifelong behavioral changes in the offspring. In order to better understand the relationship between maternal diet, brain cytoarchitecture and behavior, we investigated the effects of choline availability on cell proliferation, apoptosis and differentiation in the fetal rat brain septum. Timed-pregnant rats on day E12 were fed AIN-76 diet with varying levels of dietary choline for 6 days. We found that choline deficiency (CD) significantly decreased the rate of mitosis in the progenitor neuroepithelium adjacent to the septum. In addition, we found an increased number of apoptotic cells in the septum of CD animals compared to controls (3.5+/-0.5 vs. 1.7+/-0.5 apoptotic cells per section; p<0.05). However, CD had no effect on apoptosis in the indusium griseum (IG), a region of cortex dorsal to the septum. Using an unbiased image analysis method and a monoclonal antibody we found a decreased expression of the TOAD-64 kDa protein, a marker of commitment to neuronal differentiation during fetal development, in the dorsal lateral septum of CD animals. CD also decreased the expression of TOAD-64 kDa protein in the IG and cortical plate adjacent to the septum. These results show that dietary choline availability during pregnancy alters the timing of mitosis, apoptosis and the early commitment to neuronal differentiation by progenitor cells in regions of the fetal brain septum, as well as hippocampus, two brain regions known to be associated with learning and memory.


Subject(s)
Apoptosis/physiology , Diet , Fetal Proteins/analysis , Maternal-Fetal Exchange/physiology , Mitosis/physiology , Nerve Tissue Proteins/analysis , Septum Pellucidum/chemistry , Animals , Embryonic and Fetal Development/physiology , Female , Image Processing, Computer-Assisted , Immunohistochemistry , In Situ Nick-End Labeling , Pregnancy , Rats , Rats, Sprague-Dawley , Septum Pellucidum/pathology
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