Biomedical subjects

M Yano

Publications and source records attributed to M Yano.

At least 217 records · Page 12Linked to original sources

PubMed1999

Gene transfer of heat shock protein 70 protects lung grafts from ischemia-reperfusion injury.

BACKGROUND: We recently demonstrated that heat stress induction of heat shock protein 70 (HSP70) in donor animals before harvest decreases posttransplant ischemia-reperfusion injury in preserved rat lung isografts. The purpose of this study was to investigate the feasibility of HSP70 gene transfection into rat lung isografts using an adenoviral vector, and to study the effects of gene expression on subsequent ischemia-reperfusion injury. METHODS: In preliminary studies to determine the optimal titer, animals were injected with various titers of adenovirus-HSP70 (saline, 5 x 10(9), 1 x 10(10), and 2 x 10(10) plaque forming units [pfu]) and sacrificed 5 days after injection. To determine the optimal exposure time, animals were sacrificed at different times (0, 6, 24, and 72 hours) after intravenous injection of adenovirus-HSP70. In a subsequent series of transplant experiments, donors were allocated to three groups according to transfection strategy. Group 1 (n = 8) donors received 5 x 10(9) pfu adenovirus-HSP70 intravenously, group 2 (n = 7) donors received 5 x 10(9) pfu adenovirus-beta-galactosidase (as a virus control), and group 3 (n = 7) donors received saline and served as a negative control. Twenty-four hours after treatment all grafts were harvested and stored for 18 hours before orthotopic left lung transplantation. Twenty-four hours after implantation animals were sacrificed for assessment. The expression of HSP70 was assessed by Western blot analysis. RESULTS: In preliminary studies, HSP70 was detectable even at low titers (5 x 10(9) pfu) of adenovirus-HSP70, and was detectable at low levels as early as 6 hours after intravenous administration. Heat shock protein 70 expression was maximal at 24 hours. In transplant experiments, Western blot analysis showed that overexpression of HSP70 occurred in the HSP70-transfected lungs. The mean arterial oxygenation 24 hours after reperfusion in group 1 was superior in comparison with other groups (p < 0.05). Wet to dry weight ratio (p < 0.05) and myeloperoxidase activity (p < 0.05) were also significantly less in group 1 grafts compared with the other groups. CONCLUSIONS: This study demonstrates that in vivo, donor adenovirus-mediated gene transfer of HSP70 decreases subsequent ischemia-reperfusion injury in rat lung isografts.

Adenoviridae↗

PubMed1999

Ex vivo transfection of pulmonary artery segments in lung isografts.

BACKGROUND: Gene transfer to lung grafts may be useful in ameliorating ischemia-reperfusion injury and rejection. Proximal pulmonary artery endothelial transfection may provide beneficial downstream effects on the whole lung graft. We have already demonstrated the feasibility of in vivo and ex vivo transfection in proximal pulmonary artery segments of rat lung grafts. The aim of this study was to determine the optimal conditions for and duration of transfection. METHODS: Orthotopic left lung transplantation was performed in F344 rats after donor lung proximal pulmonary artery segments were isolated and injected with lipid 67/DOPE-chloramphenicol acetyl transferase (CAT) complementary deoxyribonucleic acid construct. Effect of exposure time was studied by exposing donor pulmonary artery segments to the construct for 0, 30, and 60 minutes prior to transplantation. In another series of experiments, pulmonary artery segments were exposed to the construct for 60 minutes prior to transplantation. Onset and duration of gene expression were determined after sacrificing animals at 3, 6, 12, and 24 hours and 3 days as well as 1 week, 2, 4, and 8 weeks after transplantation. Effect of exposure temperature was studied by exposing pulmonary artery segments to the construct for 60 minutes at 4 degrees, 10 degrees, and 23 degrees C. These recipients were sacrificed on postoperative day 3. Effect of exposure pressure was studied by using two volumes of the construct (0.01 and 0.03 mL). These recipients were sacrificed on postoperative day 3. Transgene expression was assessed by chloramphenicol acetyl transferase activity assay. RESULTS: Transgene expression was similar after 30- and 60-minute exposure. Transgene expression was evident within 3 to 6 hours after operation and persisted at 8 weeks after operation. Expression was detected at all temperatures and was equivalent at both exposure pressures. CONCLUSIONS: Gene transfection into graft pulmonary artery segments is possible under a range of conditions applicable to clinical lung transplantation.

Animals↗

PubMed1999

Transfection of pulmonary artery segments in lung isografts during storage.

BACKGROUND: Proximal pulmonary artery segment (PPAS) endothelial transfection of lung grafts may be useful in ameliorating ischemia-reperfusion injury and rejection and may provide beneficial downstream effects on the whole lung graft. Transfection immediately after lung transplantation may be efficacious in ameliorating allograft dysfunction after transplantation. METHODS: In F344 rats, the PPAS was isolated and injected with 0.03 mL of GL-67/DOPE-chloramphenicol acetyl transferase (CAT) plasmid DNA. The PPASs were exposed for 60 minutes at several temperatures. The lung grafts were stored in saline solution (group 1, n = 24) or LPDG solution (group 2, n = 27) for 12 or 24 hours at 4 degrees to 37 degrees C. In group 3 (n = 42), PPASs were stored in endothelial cell culture medium and incubated at 10 degrees or 37 degrees C in a carbon dioxide incubator for 3 to 72 hours. Group 4 (n = 18) served as transplanted controls; after 3 to 24 hours' preservation at 4 degrees C in LPDG solution, lung grafts were transplanted. Transgene expression of PPASs was assessed with two CAT activity assays, thin-layer chromatography enzyme-linked immunosorbent assay and immediately after the preservation period (groups 1 to 3) or 24 hours after transplantation (group 4). RESULTS: In group 1, transgene expression did not appear. In groups 2 and 3, transgene expression was apparent after any storage duration at 37 degrees C. Transgene expression increased successively with longer storage periods. In group 4, transgene expression was detected after any storage duration. The enzyme-linked immunosorbent assay is able to quantify the expression of CAT activity, but thin-layer chromatography is more sensitive. CONCLUSIONS: Transgene expression did not occur during conventional cold storage. Transgene expression in rat PPASs during storage is possible with warm storage (37 degrees C) and appropriate storage solution.

Animals↗

PubMed1999

Endobronchial transfection of naked TGF-beta1 cDNA attenuates acute lung rejection.

BACKGROUND: We investigated endobronchial transfection of CAT and TGF-beta1 cDNA selectively delivered to the lung graft with or without liposomes. METHODS: Phase I: F344 rats received 130 microg of naked plasmid pCF1-CAT or complexed to liposome GL67 via left main bronchus instillation. Rats were awakened (pCF1-CAT, n = 4; GL67:pCF1-CAT, n = 4) or served as donors in an isogenic transplant (pCF1-CAT, n = 5; GL67:pCF1-CAT, n = 5). ELISA was performed on lungs, hearts, and livers on POD 2. Phase II: BN lungs received TGF-beta1 sense (n = 6); antisense (n = 5); GL67:TGF-beta1 sense (n = 10); or saline solution (n = 10). F344 recipients were sacrificed on POD 5. The arterial pO2 and rejection were assessed. RT-PCR for murine TGF-beta1 was performed. RESULTS: Phase I: CAT expression was 519+/-287 pg and 63+/-68 with pCF1-CAT and 104+/-67 and 37+/-45 with GL67:pCF1-CAT, respectively, in the non-transplant and in the transplant setting. No protein was detected in the hearts, livers, and in the native lung of the recipients. Phase II: RT-PCR confirmed murine TGF-beta1 transfection. pO2 was 362.7+/-110.2 (mean mm Hg +/- SD) for sense TGF-beta1; 146.88+/-85.5 for antisense; 241.5+/-181.5 for GL67-TGF-beta1 sense; and 88.4+/-38.7 for saline. TGF-beta1 sense versus all other groups, p<0.05, GL67-TGF-beta1 sense versus saline, p = 0.01. Rejection was significantly lower for TGF-beta1 sense versus saline, p = 0.04. CONCLUSIONS: Endobronchial administration of naked plasmid achieves selective transfection of lung grafts. Using this strategy, TGF-beta1 reduces early lung allograft rejection.

Acute Disease↗

PubMed1999

Abnormal Ca2+ release from cardiac sarcoplasmic reticulum in tachycardia-induced heart failure.

OBJECTIVE: In heart failure, little information is available as to the Ca2+ release function of sarcoplasmic reticulum (SR), which plays a major role in cardiac contractile function. Here, we assessed the rapid kinetics of drug-induced Ca2+ release from cardiac SR in combination with a measurement of ryanodine binding in heart failure. METHODS: The SR vesicles were isolated from dog left ventricular (LV) muscles (normal (N), n = 10; pacing induced heart failure (HF), n = 10). The time course of SR Ca2+ release was continuously monitored by a stopped-flow apparatus using arsenazoIII as a Ca2+ indicator, and Ca2+ uptake and [3H]ryanodine binding assays were done using a filtration method. RESULTS: The amount of Ca2+ uptake was reduced in HF to 55% of N (P < 0.05). Even the more marked and earlier appeared decrease was seen in the rate constant and the initial rate of polylysine (PL; a specific release trigger)-induced Ca2+ release (P < 0.05). However, the PL concentration dependency of the initial rate shifted towards lower concentrations of PL in HF than in N ([PL] at half maximum stimulation = 0.13 vs. 0.35 microM). The [3H]ryanodine binding assay revealed a lower Bmax (pmol/mg) in HF than in N (0.91 +/- 0.19 vs. 2.64 +/- 0.59, P < 0.05), but no difference in Kd (nM) (0.95 +/- 0.29 vs. 0.90 +/- 0.11, P = n.s.). The [PL] dependency on the enhancement of [3H]ryanodine binding again showed a shift towards lower [PL] in HF than in N. CONCLUSIONS: In pacing-induced heart failure, the Ca2+ releasing function of SR is disturbed, which may result in an intra-cellular Ca2+ transient that was slowed down.

Animals↗

PubMed1999

Ex vivo transfection of transforming growth factor-beta1 gene to pulmonary artery segments in lung grafts.

OBJECTIVE: Proximal pulmonary artery segment transfection may provide beneficial downstream effects on the whole-lung graft. In this study, transforming growth factor-beta1 was transfected to proximal pulmonary artery segments, and the efficacy of transforming growth factor-beta1 transfection was examined in ischemia-reperfusion injury and acute rejection models of rat lung transplantation. METHODS: In the ischemia-reperfusion injury model, orthotopic left lung transplantation was performed in F344 rats. In group I, the PPAS was isolated and injected with saline solution. In 2 other groups, lipid67:DOPE:sense (group II) or antisense transforming growth factor-beta1pDNA construct (group III) was injected instead of saline solution. After cold preservation at 4 degrees C for 18 hours, lung grafts were implanted. Graft function was assessed 24 hours later. In the acute rejection model, donor lung grafts were harvested. Proximal pulmonary artery segments were injected with saline solution (group I) or sense (group II) or antisense lipid gene construct (group III) and then implanted. Graft function was assessed on postoperative day 5. RESULTS: In the ischemia-reperfusion injury study, there were no significant differences in oxygenation, wet-to-dry weight ratios, graft myeloperoxidase activity, or transforming growth factor-beta1 levels in platelet-poor serum or proximal pulmonary artery segment homogenates. In the acute rejection study, oxygenation was significantly improved in group II receiving transforming growth factor-beta1 (group II vs I and III, 136.0 +/- 32.5 vs 54.0 +/- 9.6 mm Hg and 53.8 +/- 14.8 mm Hg; P =.016 and.016). There were no significant pathologic differences. Transforming growth factor-beta1 concentrations from proximal pulmonary artery segment homogenates in group II were significantly higher compared with controls. CONCLUSIONS: Ex vivo transfection of transforming growth factor-beta1 to proximal pulmonary artery segments did not affect reperfusion injury of lung isografts. In acute rejection, however, ex vivo transfection of transforming growth factor-beta 1 to proximal pulmonary artery segments improved allograft function. This suggests that transfection to proximal pulmonary artery segments exerts beneficial downstream effects on the whole-lung allograft.

Acute Disease↗

PubMed1999

Relationships between apolipoprotein(a) phenotype and increase of lipoprotein(a) by troglitazone.

Troglitazone is a new oral hypoglycemic agent that reduces insulin resistance in non-insulin-dependent diabetes mellitus (NIDDM). However, this agent increases serum lipoprotein(a) [Lp(a)], which is known as an atherogenic lipoprotein. The relationships between the response of Lp(a) to troglitazone and the apolipoprotein(a) [apo(a)] phenotype were investigated in this study. Nineteen NIDDM patients were treated with troglitazone for 4 weeks. Lp(a) increased significantly from 20.1+/-16.5 mg/dL to 44.1+/-31.9 mg/dL (P<.001) in all study patients. Lp(a) increased from 25.7+/-34.2 mg/dL to 50.1+/-38.7 mg/dL (P = .03) in patients with smaller apo(a) phenotypes (S1S4 to S2S4). Lp(a) also increased from 17.5+/-12.0 mg/dL to 41.3+/-29.6 mg/dL (P<.01) in patients with larger apo(a) phenotypes (S3 to S4). Therefore, the increase of Lp(a) by troglitazone may be independent of the apo(a) phenotype.

Adult↗

PubMed1999

CAG repeat length in the androgen receptor gene is enhanced in patients with idiopathic azoospermia.

OBJECTIVES: To determine whether the number of CAG repeats in the androgen receptor gene is enhanced in patients with idiopathic azoospermia. METHODS: Using the polymerase chain reaction, the number of CAG repeats was assayed in 41 patients with idiopathic azoospermia and in 48 normozoospermic fertile men. RESULTS: In the control group, the CAG repeat length ranged from 17 to 30 (mean 23.9 +/- 2.9); in the azoospermic group, the CAG repeat length ranged from 20 to 34 (mean 26.5 +/- 3.5). The difference between the two groups was statistically significant (P = 0.0013). None of the men in the control group had a CAG repeat length greater than 31; four of the azoospermic men had 34 CAG repeats. CONCLUSIONS: Results suggest that an increase in the number of CAG repeats in the androgen receptor gene to 31 or greater may be associated with the etiology of at least some cases of idiopathic azoospermia.

Adenosine↗

PubMed1999

Acridones as inducers of HL-60 cell differentiation.

Fifteen acridone alkaloids were examined for their activity of induction of human promyelocytic leukemia cell (HL-60) differentiation. HL-60 cells were differentiated into mature monocyte/macrophage by atalaphyllidine (9), atalaphyllinine (12), and des-N-methylnoracronycine (13). The activities of NBT reduction, nonspecific esterase, and phagocytosis, were induced by 2.5 microM of 9, 12, and 13. After a 4-day treatment, 9, 12, and 13 at 10 microM inhibited clonal proliferation of HL-60 cells by 28, 96, and 63%, respectively. The structure-activity relationship established from the results revealed that hydroxyl group at C-1 and prenyl group at C-2 had an important role.

Acridines↗

PubMed1999

Immunohistochemical analysis of hepatic interferon alpha-beta receptor level: relationship between receptor expression and response to interferon therapy in patients with chronic hepatitis C.

BACKGROUND/AIMS: This study aimed to determine the expression level of interferon alpha/beta (IFN-alpha/beta) receptor in the liver immunohistochemically and evaluate its usefulness in predicting the outcome to IFN therapy in patients with chronic hepatitis C. METHODS: The level of IFN-alpha/beta receptor expression was determined in immunoperoxidase-stained pretreatment sections of 55 chronic hepatitis C patients later treated with IFN. We used liver biopsy specimens and mouse monoclonal anti-human IFN-alpha/beta receptor antibody. Quantitative analysis of immunostaining was performed by image analysis software. The level of IFN-alpha/beta receptor was expressed as Unit (U). Sustained responders were patients who showed persistent disappearance of serum HCV-RNA during the 6-month period after treatment, while non-responders showed persistence of viremia after therapy. RESULTS: Positive immunostaining was observed in the cytoplasm of hepatocytes. The mean expression level of hepatic IFN-alpha/beta receptor in sustained responders (2.65+/-1.11 U, n = 15) was significantly (p<0.001) higher than in non-responders (1.61+/-1.05 U, n = 40). A significant decrease in IFN-alpha/beta receptor expression level was observed in patients with advanced liver fibrosis. In patients with low level viremia (pretreatment serum HCV-RNA <1 Meq/ml, n = 18), the level of IFN-alpha/beta receptor in sustained responders (2.89+/-1.12 U, n = 11) was significantly (p<0.01) higher than in non-responders (0.93+/-0.33 U, n = 7). CONCLUSIONS: Our results suggest that measurement of the level of hepatic IFN-alpha/beta receptor in patients with chronic hepatitis C might be useful for predicting the response to IFN therapy. Resistance to IFN therapy in patients with chronic hepatitis C might be due to low levels of hepatic IFN-alpha/beta receptor.

Adult↗

PubMed1999

Prevalence and clinical characteristics of TT virus (TTV) in patients with sporadic acute hepatitis of unknown etiology.

BACKGROUND/AIMS: Recently, a novel DNA virus was isolated from the serum of a patient with post-transfusion non-A-G hepatitis and named TT virus. The aim of this study was to determine the prevalence and clinical characteristics of TT virus infection in patients with sporadic acute hepatitis of unknown etiology. METHODS: TT virus was investigated in the serum of 66 patients with sporadic acute hepatitis non-A-G and 50 healthy controls by semi-nested PCR with previously published primers. RESULTS: TT virus was detected in 17 (26%) of the 66 patients with sporadic acute hepatitis non-A-G and in a slightly higher rate (34%,17/50) in the control group. No significant differences in alanine aminotransferase or bilirubin concentrations were observed between the groups of patients with or without TT virus infection. Eighty per cent (12/15) of patients for whom follow up was possible had persistent viremia from 4 to 36 months, and 67% (8/12) of these patients had already normalized their levels of alanine aminotransferase. A phylogenetic tree constructed by the Neighbor Joining Method revealed that all isolates in this study were grouped within genotype 1a and 1b, without showing any association between genetic type and development of hepatic disease. CONCLUSIONS: Our results suggest that TT virus DNA is present not only in patients with sporadic acute hepatitis non-A-G but also in a large proportion of the general population. This virus was not likely to be the causative agent of hepatitis among the patients in this study.

Acute Disease↗

PubMed1999

Alterations in cardiac sarcoplasmic reticulum Ca2+ regulatory proteins in the atrial tissue of patients with chronic atrial fibrillation.

OBJECTIVES: Our purpose was to determine whether atrial fibrillation (AF) patients have alterations in sarcoplasmic reticulum (SR) Ca2+ regulatory proteins in the atrial myocardium. BACKGROUND: Clinically, AF is the most frequently encountered arrhythmia. Recent studies indicate that an inability to maintain intracellular Ca2+ homeostasis with a consequent increase in membrane-triggered activity could be the primary initiating factor in some circumstances, and that cytosolic Ca2+ abnormalities are an important mediator of sustained AF. METHODS: We measured the maximum number of [3H]ryanodine binding sites (Bmax) and the expression levels of ryanodine receptor (RyR) mRNA and calcium-adenosine triphosphatase (Ca2+-ATPase) mRNA in atrial myocardial tissue from 13 patients with AF due to mitral valvular disease (MVD) and 9 patients with normal sinus rhythm (NSR). RESULTS: In AF patients, 1) Bmax was significantly lower in each atrium (0.21+/-0.03 pmol/mg [right], 0.16+/-0.04 pmol/mg [left]) than in the right atrium (0.26+/-0.08 pmol/mg) of NSR patients; 2) Bmax was significantly lower in the left atrium than in the right atrium; 3) Bmax in the left atrium was significantly lower at higher levels of pulmonary capillary wedge pressure; 4) the expression level of RyR mRNA was significantly lower in both the left (1.24 x 10(-2)+/-1.28 x 10(-2)) and right (1.70 x 10(-2)+/-1.78 x 10(-2)) atrium than in the right atrium of NSR patients (6.11 x 10(-2)+/-2.79 x 10(-2)); and 5) the expression level of Ca2+-ATPase mRNA was significantly lower in both the left (5.67 x 10(-2)+/-4.01 x 10(-2)) and right (7.71 x 10(-2)+/-3.56 x 10(-2)) atrium than in the right atrium (12.60 x 10(-2)+/-3.92 x 10(-2)) of NSR patients. CONCLUSIONS: These results provide the first direct evidence of abnormalities in the Ca2+ regulatory proteins of the atrial myocardium in chronic AF patients. Conceivably, such abnormalities may be involved in the initiation and/or perpetuation of AF.

Aged↗

PubMed1999

Effect of angiotensin II receptor antagonism on vascular hypertrophy and aortic impedance in abdominal aortic-banded rat.

Vascular hypertrophy is considered to be an adaptive response to increased arterial wall stress in hypertension. Although there are several reports concerning the effect of angiotensin II inhibition on the development of vascular hypertrophy, little information is available as to its effect on vascular hypertrophy in parallel with the evaluation of arterial wall characteristics. The goal of this study was to evaluate the effect of angiotensin II type 1 receptor antagonist TCV-116 on pressure overload-induced vascular hypertrophy in parallel with the assessment of aortic impedance. Low dose (LD; 0.3 mg/kg/day) or high dose (HD; 3.0 mg/kg/day) of TCV-116 was administered to abdominal aortic-banded rats over 4 weeks; then hemodynamics and morphology were evaluated. In both the LD and HD groups, blood pressures were decreased to a similar extent compared with those of the vehicle-treated group (P < .05). Left ventricular (LV) weight and LV weight/body weight ratio was inhibited in both TCV-116-treated groups (P < .05), whereas the media cross-sectional area of the aorta was inhibited only in the HD group (P < .05). After the treatment of TCV-116 (LD, HD), total systemic resistance was decreased compared with the vehicle-treated group (P < .05), but there was no significant difference between the TCV-116-treated groups. In contrast, the first harmonic of the impedance modulus revealed the decrease only in the HD group (P < .05). TCV-116 attenuated the development of pressure overload LV hypertrophy and vascular hypertrophy as well; however, the dose of TCV-116 required for the inhibition of vascular hypertrophy was significantly higher than that for LV hypertrophy. Vascular hypertrophy may be less pressure dependent than cardiac hypertrophy. On chronic addition of high dose of TCV-116, arterial wave reflection was decreased in association with the attenuation of vascular hypertrophy.

Angiotensin Receptor Antagonists↗

PubMed1999

Effect of parenteral and enteral nutrition on hepatic albumin synthesis in rats.

The route of nutrient delivery may alter the production of albumin and induce changes at the molecular level. Donryu rats (n = 75) were divided into the following three groups. The oral feeding (OR) group received a non-purified solid diet ad libitum, the parenteral nutrition (PN) group received a total parenteral nutrition (TPN) solution intravenously, and the enteral nutrition (EN) group received intragastric infusions of the TPN solution for 7 d. Serum albumin and glucocorticoid levels were measured and messenger RNA (mRNA) levels of albumin and hepatic specific transcription factors in the liver were analyzed. Serum albumin and albumin mRNA levels in the PN group became significantly decreased compared to those in the OR group, whereas the EN group did not show a significant difference compared to the OR group. mRNA levels of DBP, D-site binding transcription factor for the albumin gene, showed a circadian rhythm in the OR and EN groups, but not in the PN group, as indicated by a DBP mRNA level at 2200 h in the PN group that was significantly lower than that in the OR group. mRNA levels of C/EBP alpha, CCAAT-enhancer binding protein alpha, were highest in the OR group and lowest in the PN group. In contrast, mRNA levels of C/EBP beta were highest in the PN group and lowest in the OR group. Serum glucocorticoid level showed a circadian rhythm in the OR group, highest at 2200 h and lowest at 1000 h, whereas such a rhythm was not found in either the PN or the EN group. Albumin synthesis was down-regulated in PN in association with changes in transcription factors. A loss of circadian rhythm reflected in changes of DBP mRNA and serum glucocorticoid level may play a role. Down-regulation of albumin was improved by enteral feeding, indicating that EN is more advantageous for albumin synthesis than PN.

Animals↗

PubMed1999

Changes of liver-enriched nuclear transcription factors for albumin gene in starvation in rats.

The regulatory mechanism of albumin gene transcription was examined using male Donryu rats (7 wk old) starved for 1 or 3 d. At the designated times, the rats were sacrificed to harvest the liver and to measure the serum albumin level. Neither the serum albumin nor the albumin messenger RNA (mRNA) level showed a significant change for these starvation periods. Among nuclear factors binding to the D site of albumin gene promoter, the CCAAT/enhancer binding protein alpha (C/EBP alpha) mRNA level showed a decrease and the D site binding protein (DBP) mRNA level tended to decrease after 3 d of starvation. In contrast, the C/EBP beta mRNA level showed a significant increase at day 1. As a B site binding nuclear factor, the hepatocyte nuclear factor 1 (HNF-1) mRNA level significantly increased at day 1. Gel mobility-shift analysis combined with Western immunoblotting confirmed the presence of D site binding proteins composed of DBP and C/EBP alpha and beta in both groups subjected to oral feeding and to 3-d starvation, though quantitative analysis could not be done. In conclusion, the nuclear transcription factors binding to the albumin gene promoter undergo regulatory changes during 3 d of starvation, whereas there is no significant decrease in the albumin mRNA level.

Albumins↗

PubMed1999

HL-60 differentiating activity and flavonoid content of the readily extractable fraction prepared from citrus juices.

Citrus plants are rich sources of various bioactive flavonoids. To eliminate masking effects caused by hesperidin, naringin, and neoeriocitrin, the abundant flavonoid glycosides which make up 90% of the conventionally prepared sample, the readily extractable fraction from Citrus juice was prepared by adsorbing on HP-20 resin and eluting with EtOH and acetone from the resin and was subjected to HL-60 differentiation assay and quantitative analysis of major flavonoids. Screening of 34 Citrus juices indicated that King (C. nobilis) had a potent activity for inducing differentiation of HL-60, and the active principles were isolated and identified as four polymethoxylated flavonoids, namely, nobiletin, 3,3',4',5,6,7, 8-heptamethoxyflavone, natsudaidain, and tangeretin. HPLC analysis of the readily extractable fraction also indicated that King contained high amounts of these polymethoxylated flavonoids among the Citrus juices examined. Principal component and cluster analyses of the readily extractable flavonoids indicated peculiarities of King and Bergamot.

Cell Differentiation↗

PubMed1999

Identification of coumarins from the fruit of Citrus hystrix DC as inhibitors of nitric oxide generation in mouse macrophage RAW 264.7 cells.

Three known coumarins have been isolated from Citrus hystrix DC as inhibitors of both lipopolysaccharide (LPS) and interferon-gamma (IFN-gamma)-induced nitric oxide (NO) generation in RAW 264.7 cells. The inhibitory activity of bergamottin (IC(50) = 14 microM) was comparable to that of N-(iminoethyl)-L-ornithine (L-NIO) (IC(50) = 7. 9 microM), whereas oxypeucedanin and 5-[(6',7'-dihydroxy-3', 7'-dimethyl-2-octenyl)oxy]psoralen, structurally different from bergamottin only in their side-chain moieties, were notably less active. Using 21 coumarins, we structurally classified various types of coumarins into groups A-C: (A) bearing an isoprenyl (IP) or a geranyl (GR) group, highly active; (B) bearing an IP group cyclized to a coumarin ring, moderately active; (C) bearing an IP group modified with hydroxyl group(s) and/or having other functional groups except for the IP, completely inactive. Cellular uptake studies suggested that coumarins in group C are inactive because of poor permeability to the cell membrane.

Animals↗

PubMed1999

Antiproliferative effects of the readily extractable fractions prepared from various citrus juices on several cancer cell lines.

To eliminate the masking effect by flavonoid glycosides, which comprise approximately 70% of conventionally prepared sample, the readily extractable fraction from Citrus juice, which was prepared by adsorbing on HP-20 resin and eluting with ethanol and acetone from the resin, was subjected to antiproliferative tests against several cancer cell lines. Screening of 34 Citrus juices indicated that King (Citrus nobilis) strongly inhibited proliferation of all cancer cell lines examined. Sweet lime and Kabuchi inhibited three of the four cancer cell lines. In contrast, these samples were substantially less cytotoxic toward normal human cell lines.

Antineoplastic Agents, Phytogenic↗