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result(s) for
"Higuchi, M"
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A Simplified Method for Three-Dimensional (3-D) Ovarian Tissue Culture Yielding Oocytes Competent to Produce Full-Term Offspring in Mice
by
Maeda, Yuuki
,
Horiuchi, Toshitaka
,
Yamazaki, Yukiko
in
Activin
,
Activins - pharmacology
,
Analysis
2015
In vitro growth of follicles is a promising technology to generate large quantities of competent oocytes from immature follicles and could expand the potential of assisted reproductive technologies (ART). Isolated follicle culture is currently the primary method used to develop and mature follicles in vitro. However, this procedure typically requires complicated, time-consuming procedures, as well as destruction of the normal ovarian microenvironment. Here we describe a simplified 3-D ovarian culture system that can be used to mature multilayered secondary follicles into antral follicles, generating developmentally competent oocytes in vitro. Ovaries recovered from mice at 14 days of age were cut into 8 pieces and placed onto a thick Matrigel drop (3-D culture) for 10 days of culture. As a control, ovarian pieces were cultured on a membrane filter without any Matrigel drop (Membrane culture). We also evaluated the effect of activin A treatment on follicle growth within the ovarian pieces with or without Matrigel support. Thus we tested four different culture conditions: C (Membrane/activin-), A (Membrane/activin+), M (Matrigel/activin-), and M+A (Matrigel/activin+). We found that the cultured follicles and oocytes steadily increased in size regardless of the culture condition used. However, antral cavity formation occurred only in the follicles grown in the 3-D culture system (M, M+A). Following ovarian tissue culture, full-grown GV oocytes were isolated from the larger follicles to evaluate their developmental competence by subjecting them to in vitro maturation (IVM) and in vitro fertilization (IVF). Maturation and fertilization rates were higher using oocytes grown in 3-D culture (M, M+A) than with those grown in membrane culture (C, A). In particular, activin A treatment further improved 3-D culture (M+A) success. Following IVF, two-cell embryos were transferred to recipients to generate full-term offspring. In summary, this simple and easy 3-D ovarian culture system using a Matrigel drop and activin A supplementation (M+A) provides optimal and convenient conditions to support growth of developmentally competent oocytes in vitro.
Journal Article
Long-term intake of dietary fat and risk of ulcerative colitis and Crohn's disease
by
Willett, Walter C
,
Ananthakrishnan, Ashwin N
,
Richter, James M
in
Adult
,
Cell adhesion & migration
,
Colitis, Ulcerative - epidemiology
2014
Introduction Dietary fats influence intestinal inflammation and regulate mucosal immunity. Data on the association between dietary fat and risk of Crohn's disease (CD) and ulcerative colitis (UC) are limited and conflicting. Methods We conducted a prospective study of women enrolled in the Nurses’ Health Study cohorts. Diet was prospectively ascertained every 4 years using a validated semi-quantitative food frequency questionnaire. Self-reported CD and UC were confirmed through medical record review. We examined the effect of energy-adjusted cumulative average total fat intake and specific types of fat and fatty acids on the risk of CD and UC using Cox proportional hazards models adjusting for potential confounders. Results Among 170 805 women, we confirmed 269 incident cases of CD (incidence 8/100 000 person-years) and 338 incident cases of UC (incidence 10/100 000 person-years) over 26 years and 3 317 338 person-years of follow-up. Cumulative energy-adjusted intake of total fat, saturated fats, unsaturated fats, n-6 and n-3 polyunsaturated fatty acids (PUFAs) were not associated with risk of CD or UC. However, greater intake of long-chain n-3 PUFAs was associated with a trend towards lower risk of UC (HR 0.72, 95% CI 0.51 to 1.01). In contrast, high long-term intake of trans-unsaturated fatty acids was associated with a trend towards an increased incidence of UC (HR 1.34, 95% CI 0.94 to 1.92). Conclusions A high intake of dietary long-chain n-3 PUFAs may be associated with a reduced risk of UC. In contrast, high intake of trans-unsaturated fats may be associated with an increased risk of UC.
Journal Article
A Prospective Study of Cigarette Smoking and the Risk of Inflammatory Bowel Disease in Women
by
Richter, James M
,
Fuchs, Charles S
,
Khalili, Hamed
in
Adult
,
Biological and medical sciences
,
Colitis, Ulcerative - epidemiology
2012
Long-term data on the influence of cigarette smoking, especially cessation, on the risk of Crohn's disease (CD) and ulcerative colitis (UC) are limited.
We conducted a prospective study of 229,111 women in the Nurses' Health Study (NHS) and Nurses' Health Study II (NHS II). Biennially, we collected updated data on cigarette smoking, other risk factors, and diagnoses of CD or UC confirmed by medical record review.
Over 32 years in NHS and 18 years in NHS II, we documented 336 incident cases of CD and 400 incident cases of UC. Compared with never smokers, the multivariate hazard ratio (HR) of CD was 1.90 (95% confidence interval (CI), 1.42-2.53) among current smokers and 1.35 (95% CI, 1.05-1.73) among former smokers. Increasing pack-years was associated with increasing risk of CD (Ptrend < 0.0001), whereas smoking cessation was associated with an attenuation of risk. By contrast, the multivariate HR of UC was 0.86 (95% CI, 0.61-1.20) among current smokers and 1.56 (95% CI, 1.26-1.93) among former smokers. The risk of UC was significantly increased within 2-5 years of smoking cessation (HR, 3.06; 95% CI, 2.00-4.67) and remained persistently elevated over 20 years.
Current smoking is associated with an increased risk of CD, but not UC. By contrast, former smoking is associated with an increased risk of UC, with risk persisting over two decades after cessation.
Journal Article
NEDDylation controls the target specificity of E2F1 and apoptosis induction
2013
The transcription factor E2F1 has pivotal roles in both cell proliferation and cell death, and is an important molecular target in cancer. Under proliferative conditions E2F1 induces the expression of genes that promote cell cycle progression, such as
E2F2
, whereas under proapoptotic conditions E2F1 induces expression of genes such as
p73
that lead to apoptosis. The mechanism by which the apoptotic function of E2F1 is activated remains unclear, however. We now show that members of the E2F family are covalently conjugated with the ubiquitin-like modifier NEDD8. Overexpression of SENP8, a NEDD8-specific cysteine protease, resulted in deNEDDylation of E2F1 and promoted its transactivation activity at the
p73
gene but not at the
E2F2
gene. Knockdown of SENP8, on the other hand, attenuated p73 expression and apoptosis induced by E2F1 or by DNA damage. SENP8 also promoted the interaction between E2F1 and its cofactor Microcephalin 1, which is required for p73 induction. These results suggest that NEDDylation is a molecular trigger that modifies the target specificity of E2F1, and could have important implications for E2F1 regulation of apoptosis.
Journal Article
A cross-sectional study of sarcopenia in Japanese men and women: reference values and association with cardiovascular risk factors
by
Tanimoto, M.
,
Suzuki, K.
,
Yamamoto, K.
in
Absorptiometry, Photon
,
Adiposity - ethnology
,
Adolescent
2010
In this study of Japanese men and women, we determine reference values for sarcopenia and test the hypothesis that sarcopenia is associated with risk factors for cardiovascular disease, independent of waist circumference. A total of 1,488 Japanese men and women aged 18–85 years participated in this study. Appendicular muscle mass (AMM) was measured by dual-energy X-ray absorptiometry. Reference values for classes 1 and 2 sarcopenia (skeletal muscle index: AMM/height
2
, kg m
−2
) in each sex were defined as values one and two standard deviations below the sex-specific means of reference values obtained in this study from young adults aged 18–40 years. The reference values for class 1 and class 2 sarcopenia were 7.77 and 6.87 kg m
−2
in men and 6.12 and 5.46 kg m
−2
in women. In subjects both with class 1 and class 2 sarcopenia, body mass index and % body fat were significantly lower than in normal subjects. Despite whole-blood glycohaemoglobin A1c in men with class 1 sarcopenia was significantly higher than in normal subjects, and brachial-ankle pulse wave velocity in women both with class 1 and class 2 sarcopenia were significantly higher than in normal subjects, using one-way ANCOVA with adjustment for the covariate of waist circumference. Although sarcopenia is associated with thin body mass, it is associated with more glycation of serum proteins in men and with greater arterial stiffness in women, independent of waist circumference.
Journal Article
Measurement of psychological state changes at low dopamine transporter occupancy following a clinical dose of mazindol
by
Yokokawa, K.
,
Takahata, K.
,
Seki, C.
in
Biomedical and Life Sciences
,
Biomedicine
,
Brain - diagnostic imaging
2017
Rationale
The beneficial effects of psychostimulant drugs in the treatment of psychiatric disorders occur because they increase the extracellular dopamine concentration by inhibiting re-uptake of extracellular dopamine at dopamine transporters. However, the psychological effects at low dopamine transporter occupancy have not been well demonstrated.
Objectives
The purpose of the study was to evaluate the psychological effects, dopamine transporter occupancy, and dopamine release induced by a single oral administration of a clinical dose of mazindol.
Methods
Ten healthy male volunteers were orally administered a placebo and a clinical dose of mazindol (1.5 mg) on separate days. The psychological effects of mazindol were assessed using a visual analogue scale to detect alterations in the state of consciousness. The amount of blockade of dopamine transporters was assessed using positron emission tomography with [
18
F]FE-PE2I and extracellular dopamine release was measured as the amount of change in [
11
C]raclopride binding.
Results
Following administration of a clinical dose of mazindol, the dopamine transporters were blocked by 24–25 %, and the binding potential of [
11
C]raclopride was reduced by 2.8–4.6 %. The differences of a score measuring derealisation and depersonalization associated with a positive basic mood were significantly correlated with the change in the [
11
C]raclopride binding in the limbic striatum.
Conclusions
A subtle alteration in the state of consciousness was detected with a correlation to the changes in the [
11
C]raclopride binding, which implies that a subtle alteration in extracellular dopamine concentration in the limbic striatum by a small amount of dopamine transporter occupancy can affect the state of consciousness.
Trial registration
https://upload.umin.ac.jp/cgi-open-bin/ctr_e/ctr_view.cgi?recptno=R000009703
UMIN000008232
Journal Article
Identification and Characterization of a Novel Association between Dietary Potassium and Risk of Crohn’s Disease and Ulcerative Colitis
by
Ananthakrishnan, Ashwin N.
,
Khalili, Hamed
,
Curhan, Gary C.
in
Autoimmune diseases
,
Birth control
,
CD4 antigen
2016
Recent animal studies have identified that dietary salt intake may modify the risk and progression of autoimmune disorders through modulation of the IL-23/T
17 pathway, which is critical in the pathogenesis of ulcerative colitis (UC) and Crohn's disease (CD).
We conducted a prospective study of U.S. women enrolled in the Nurses' Health Study (NHS) and NHSII who provided detailed and validated information on diet and lifestyle beginning in 1984 in NHS and 1991 in NHSII. We confirmed incident cases of UC and CD reported through 2010 in NHS and 2011 in NHSII. We used Cox proportional hazards models to calculate hazard ratios and 95% confidence intervals. In a case-control study nested within these cohorts, we evaluated the interaction between single nucleotide polymorphisms (SNPs) in genes involved in T
17 pathway and dietary potassium on risk of CD and UC. In a cohort of healthy volunteers, we also assessed the effect of supplemental potassium on development of naïve and memory T cells, differentiated with TGFβ1 or T
17 conditions.
Among a total of 194,711 women over a follow-up of 3,220,247 person-years, we documented 273 cases of CD and 335 cases of UC. Dietary intake of potassium (
= 0.005) but not sodium (
= 0.44) was inversely associated with risk of CD. Although, both dietary potassium and sodium were not significantly associated with risk of UC, there was a suggestion of an inverse association with dietary potassium (
= 0.08). The association of potassium with risk of CD and UC appeared to be modified by loci involved in the T
17 pathway that have previously been associated with susceptibility to CD, particularly SNP rs7657746 (
) (
= 0.004 and 0.01, respectively).
, potassium enhanced the expression of Foxp3 in both naïve and memory CD4+ T cells
activating Smad2/3 and inhibiting Smad7 in T
17 cells.
Dietary potassium is inversely associated with risk of CD with both
and gene-environment interaction data suggesting a potential role for potassium in regulating immune tolerance through its effect on Tregs and T
17 pathway.
Journal Article
Intracellular oxygen determined by respiration regulates localization of Ras and prenylated proteins
2015
Reduction of mitochondrial DNA (mtDNA) content induces the reduction of oxidative phosphorylation and dependence on fermentative glycolysis, that is, the Warburg effect. In aggressive prostate cancer (PCa), the reduction of mtDNA reduces oxygen consumption, increases intracellular oxygen concentration, and induces constitutive activation of Ras. Many essential proteins for cell death, growth, differentiation, and development, such as Ras, require prenylation for subcellular localization and activation. Prenylation of a protein is defined as the attachment of isoprenoids to a cysteine residue at or near the C-terminus. 3-Hydroxy-3-methyl-glutaryl-coenzyme A reductase (HMGR) produces isoprenoids, and is posttranslationally regulated by oxygen. We investigated a critical role of intracellular oxygen in membrane localization of prenylated proteins. Localization of prenylated proteins (H-Ras, prelamin A/C, and Rab5a) was observed in poorly differentiated PCa (PC-3) and well-differentiated PCa (LNCaP) cells. PC-3 cells exhibited high intracellular oxygen concentration, and H-Ras, prelamin A/C, and Rab5a were localized to various membranes (Golgi and plasma membrane, nuclear membrane, and early endosomes, respectively). Remarkably, exogenous hypoxia (0.2% O
2
) in PC-3 cells induced intracellular hypoxia and changed the localization of the prenylated proteins. H-Ras and Rab5a were translocated to cytosol, and prelamin A/C was in the nucleus forming an abnormal nuclear envelope. The localization was reversed by mevalonate indicating the involvement of mevalonate pathway. In contrast, in LNCaP cells, exhibiting low intracellular oxygen concentration, H-Ras and Rab5a were localized in the cytosol, and prelamin A/C was inside the nucleus forming an inadequate nuclear envelope. Exogenous hyperoxia (40% O
2
) increased the intracellular oxygen concentration and induced Ras translocation from cytosol to the membrane. Prelamin A/C was translocated to the nuclear membrane and formed a proper nuclear envelope. Rab5a was translocated to the early endosomes. The specific localizations of the prenylated proteins were dependent on intracellular oxygen concentration. These results demonstrate that intracellular oxygen concentration regulates the localization and activation of prenylated proteins.
Journal Article
Physical activity and risk of inflammatory bowel disease: prospective study from the Nurses’ Health Study cohorts
by
Korzenik, Joshua R
,
Liao, Xiaomei
,
Ananthakrishnan, Ashwin N
in
Adult
,
Age Factors
,
Autophagy
2013
Objective To examine the association between physical activity and risk of ulcerative colitis and Crohn’s disease.Design Prospective cohort study.Setting Nurses’ Health Study and Nurses’ Health Study II.Participants 194 711 women enrolled in the Nurses’ Health Study and Nurses’ Health Study II who provided data on physical activity and other risk factors every two to four years since 1984 in the Nurses’ Health Study and 1989 in the Nurses’ Health Study II and followed up through 2010.Main outcome measure Incident ulcerative colitis and Crohn’s disease.Results During 3 421 972 person years of follow-up, we documented 284 cases of Crohn’s disease and 363 cases of ulcerative colitis. The risk of Crohn’s disease was inversely associated with physical activity (P for trend 0.02). Compared with women in the lowest fifth of physical activity, the multivariate adjusted hazard ratio of Crohn’s disease among women in the highest fifth of physical activity was 0.64 (95% confidence interval 0.44 to 0.94). Active women with at least 27 metabolic equivalent task (MET) hours per week of physical activity had a 44% reduction (hazard ratio 0.56, 95% confidence interval 0.37 to 0.84) in risk of developing Crohn’s disease compared with sedentary women with <3 MET h/wk. Physical activity was not associated with risk of ulcerative colitis (P for trend 0.46). The absolute risk of ulcerative colitis and Crohn’s disease among women in the highest fifth of physical activity was 8 and 6 events per 100 000 person years compared with 11 and 16 events per 100 000 person years among women in the lowest fifth of physical activity, respectively. Age, smoking, body mass index, and cohort did not significantly modify the association between physical activity and risk of ulcerative colitis or Crohn’s disease (all P for interaction >0.35).Conclusion In two large prospective cohorts of US women, physical activity was inversely associated with risk of Crohn’s disease but not of ulcerative colitis.
Journal Article
Consumption of oxygen: a mitochondrial-generated progression signal of advanced cancer
2012
Changes in mitochondrial genome such as mutation, deletion and depletion are common in cancer and can determine advanced phenotype of cancer; however, detailed mechanisms have not been elucidated. We observed that loss of mitochondrial genome reversibly induced overexpression and activation of proto-oncogenic Ras, especially K-Ras 4A, responsible for the activation of AKT and ERK leading to advanced phenotype of prostate and breast cancer. Ras activation was induced by the overexpression of 3-hydroxy-3-methyl-glutaryl-CoA reductase (HMGR), the rate-limiting enzyme of the mevalonate pathway. Hypoxia is known to induce proteasomal degradation of HMGR. Well differentiated prostate and breast cancer cells with high mitochondrial DNA content consumed a large amount of oxygen and induced hypoxia. Loss of mitochondrial genome reduced oxygen consumption and increased in oxygen concentration in the cells. The hypoxic-to-normoxic shift led to the overexpression of HMGR through inhibiting proteasomal degradation. Therefore, reduction of mitochondrial genome content induced overexpression of HMGR through hypoxic to normoxic shift and subsequently the endogenous induction of the mevalonate pathway activated Ras that mediates advanced phenotype. Reduction of mitochondrial genome content was associated with the aggressive phenotype of prostate cancer
in vitro
cell line model and tissue specimens
in vivo
. Our results elucidate a coherent mechanism that directly links the mitochondrial genome with the advanced progression of the disease.
Journal Article