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Biomedical subjects

C E Green

Publications and source records attributed to C E Green.

At least 37 records · Page 2Linked to original sources
PubMed1994

Lipopolysaccharide binding protein expression in primary human hepatocytes and HepG2 hepatoma cells.

Lipopolysaccharide (LPS)-binding protein (LBP) is a normal plasma protein and an acute phase reactant important for host responses to Gram-negative bacteria and LPS. LBP forms high affinity complexes with LPS which bind to CD14, a monocyte surface protein, to initiate the release of inflammatory mediators. We found that human primary hepatocytes synthesize LBP and that the synthesis is up-regulated by interleukin (IL)-6. To examine this phenomenon in more detail, we evaluated the capacity of IL-6, IL-1, and tumor necrosis factor to induce LBP synthesis in HepG2 cells in the presence or absence of dexamethasone. IL-6 induced LBP synthesis. Dexamethasone, IL-1, and tumor necrosis factor had a synergistic effect when combined with IL-6, but demonstrated minimal effect independently. LBP biosynthesis was evaluated by immunoprecipitation of 35S-labeled LBP from HepG2 supernatants, measurement of steady-state LBP mRNA levels, and analysis of LBP-dependent LPS binding to CD14 positive cells. An 35S-labeled, 60-kDa protein was immunoprecipitated with anti-LBP antibody from IL-6-stimulated HepG2 cell supernatants. Northern blot analysis of cellular RNA revealed an increase in LBP mRNA in IL-6-stimulated cells. CD14 expressing cells bound fluoresceinated LPS in the presence of supernatants from HepG2 cells treated with IL-6. These data provide the first information about specific cytokine and dexamethasone regulation of LBP expression in HepG2 cells. LBP behaves like a Type 1 acute phase protein.

Acute-Phase Proteins↗
PubMed1993

Effects of soya bean flakes and liquorice root extract on enzyme induction and toxicity in B6C3F1 mice.

Both soya bean flakes (SBF) and liquorice root extract (LRE) have previously been reported to have anticarcinogenic properties, which have been thought to be related to an increased activity of specific enzymes responsible for the detoxification of chemical carcinogens. 30- and 90-day studies were conducted in male B6C3F1 mice to determine which, if any, of several detoxification enzymes are induced by SBF or LRE. Mice fed 8 and 25% LRE showed a variety of adverse clinical signs, poor weight gain and 30% mortality. Significant increases in liver:body weight ratios were observed in both the SBF and LRE groups. No significant treatment-related gross autopsy findings were observed in any of the SBF groups. A number of abnormalities were observed in the LRE groups, including lesions of the kidney, liver, spleen and thymus. Liver samples from the 90-day study were analysed for 7-ethoxycoumarin O-deethylase (7-ECOD), benzo[a]pyrene hydroxylase (BPH), superoxide dismutase (SOD), glutathione S-transferase (GST) and UDP-glucuronyl transferase (UDPGT) at 90 days, and at an interim 30-day autopsy. No treatment-related increases were observed for BPH or SOD. Both SBF and LRE induced modest increases in UDPGT activity. SBF induced modest increases in GST activity, but LRE decreased this activity. 7-ECOD activity was significantly increased by LRE and decreased by SBF. Samples from a 30-day study in which both LRE and SBF were administered at various dose levels were examined for UDPGT activity; all dose groups showed decreases in UDPGT activity relative to controls. The results suggest that both SBF and LRE may alter the activities of specific enzymes involved in the detoxification of chemical carcinogens; however, the combination of these two foodstuffs may not produce an additive effect in B6C3F1 mice.

Administration, Oral↗
PubMed1992

Effects of estrogen replacement therapy on serum lipid values and angiographically defined coronary artery disease in postmenopausal women.

To examine the effects of estrogen replacement on lipids and angiographically defined coronary artery disease (CAD) in postmenopausal women, lipid profiles were obtained in 90 consecutive postmenopausal women undergoing diagnostic coronary angiography. Eighteen women (20%) were receiving estrogen and 72 (80%) were not. CAD (defined as greater than or equal to 25% luminal diameter narrowing in a major coronary artery) was present in only 22% of women (4 of 18) receiving estrogen and in 68% (49 of 72) who were not (p less than 0.001), with an odds ratio of 0.13. Mean high-density lipoprotein (HDL) cholesterol level was significantly higher (63 +/- 6 vs 48 +/- 2; p less than 0.01) and mean total/HDL cholesterol ratio significantly lower in women receiving estrogen than in those who were not (4.2 +/- 0.5 vs 5.1 +/- 0.2; p less than 0.05). The other lipid values were similar in both groups. On multiple logistic regression analysis, absence of estrogen use was the most powerful independent predictor of the presence of CAD (p less than 0.001), with total/HDL cholesterol ratio as the only other variable selected (p less than 0.01). Thus, among 90 consecutive postmenopausal women undergoing diagnostic coronary angiography, estrogen replacement therapy was associated with an 87% reduction in the prevalence of CAD, and those receiving estrogen had a significantly higher mean HDL cholesterol level and lower mean total/HDL cholesterol ratio.

Aged↗
PubMed1991

Usefulness of the total cholesterol to high-density lipoprotein cholesterol ratio in predicting angiographic coronary artery disease in women.

To investigate the relation between lipids and angiographic coronary artery disease (CAD) in women, fasting lipid profiles were obtained on 108 women undergoing coronary angiography (group I). CAD, defined as greater than or equal to 25% luminal diameter narrowing in a major coronary artery, was present in 57 (53%). Neither serum total cholesterol nor triglyceride levels correlated with the presence of CAD. Mean total/high-density lipoprotein (HDL) cholesterol ratio was higher among women with than without CAD (5.5 +/- 0.3 vs 4.2 +/- 0.2, p less than 0.0001). Multiple regression analyses identified a higher total/HDL cholesterol ratio as the variable most predictive of the presence (p less than 0.001), extent (number of narrowed arteries) (p less than 0.0001), and severity (% maximum stenosis) (p less than 0.001) of CAD. Age and lack of estrogen use were also independently associated with the presence of CAD, age and low-density lipoprotein cholesterol level were additional indicators of extent, and age was the only other discriminator of severity of CAD. In 56 women with total cholesterol less than 200 mg/dl (group II), mean total/HDL cholesterol ratio was higher in women with (n = 24) than without CAD (4.3 +/- 0.2 vs 3.5 +/- 0.2, p = 0.01). Higher total/HDL cholesterol ratio was the variable most predictive of the presence of CAD (p = 0.01), and the lone variable associated with severity (p less than 0.001) after adjustment for other risk factors. Age was independently associated with presence and extent, and hypertension was also independently related to extent.(ABSTRACT TRUNCATED AT 250 WORDS)

Age Factors↗
PubMed1991

Relation of stenosis resolution pressure to long-term clinical outcome after successful percutaneous transluminal coronary angioplasty.

Variables associated with a poor long-term prognosis after successful percutaneous transluminal coronary angioplasty (PTCA) include a short duration of symptoms before PTCA, unstable angina and the presence of thrombus at the PTCA site. These imply a component of transient or dynamic obstruction as opposed to a pure fixed obstruction. It is postulated that resolution pressure (i.e., the pressure at which complete balloon inflation occurs) may also correlate with prognosis after successful PTCA. In 173 consecutive patients undergoing successful, elective, single-lesion PTCA, 48 (28%) were found to have narrowings that resolved at less than or equal to 2 atm (group 1) and 125 (72%) were found to have narrowings resolved at greater than 2 atm (group 2). There were no significant differences in baseline, anatomic or procedural variables between the 2 groups, except that angiographic coronary dissection occurred in 17% of group 1 patients versus 40% of group 2 patients (p less than 0.007). During a mean follow-up of 12.0 +/- 6.1 months, the incidence of cardiac events (repeat PTCA, coronary artery bypass grafting or myocardial infarction) was 29% in group 1 versus 15% in group 2 (p less than 0.05). The overall incidence of angina was similar between the groups (25 vs 28%), but Canadian Cardiovascular Association class 4 angina occurred significantly more frequently in group 1 than group 2 (21 vs 8%) (p less than 0.04). These data suggest that a low resolution pressure is associated with a higher incidence of unstable angina and recurrent cardiac events during follow-up than higher resolution pressures.

Aged↗
PubMed1991

Relation of serum lipoprotein cholesterol levels to presence and severity of angiographic coronary artery disease.

To assess the relation of lipid levels to angiographic coronary artery disease (CAD), lipid profiles were obtained on 125 men and 72 women undergoing diagnostic coronary angiography. CAD, defined as greater than or equal to 25% diameter narrowing in a major coronary artery, was present in 106 men (85%) and 54 women (75%). Multiple regression analyses revealed that only high-density lipoprotein (HDL) cholesterol level in men, and age and total/HDL cholesterol ratio in women, were independently associated with the presence of CAD after adjustment for other risk factors. HDL cholesterol level and age were significantly correlated with both extent (number of diseased vessels) and severity (percent maximum stenosis) of CAD in men. In women, age was the only independent variable related to severity, whereas age and total/HDL cholesterol ratio were related to extent. Of 71 patients with total cholesterol less than 200 mg/dl, 79% had CAD. With multiple regression analyses, HDL cholesterol was the only variable independently related to the presence and severity of CAD in these patients after adjustment for age and gender; extent was significantly associated with age and male gender, and was unrelated to any of the lipid parameters. With use of multiple logistic and linear regression analyses of the group of 197 patients, HDL cholesterol was the most powerful independent variable associated with the presence and severity of CAD after adjustment for age and gender. HDL cholesterol was also an independent predictor of extent. Age was independently associated with each of the end points examined, and was the variable most significantly related to extent. These data add to the growing body of information demonstrating an important association between HDL and CAD.

Adrenergic beta-Antagonists↗
PubMed1991

Binding of anti-acetaldehyde IgG antibodies to hepatocytes with an acetaldehyde-phosphatidylethanolamine adduct on their surface.

We have previously shown that antibodies raised against acetaldehyde adducts of protein cross-react with an acetaldehyde adduct of dioleoylphosphatidylethanolamine, N-ethyl-dioleoylphosphatidylethanolamine, when the latter is incorporated into hexagonal phase phospholipid micelles. In the present study we demonstrate that these same IgG antibodies cross-react with N-ethyl-dioleoylphosphatidylethanolamine when this adduct is incorporated into the surface of hepatocytes. Hapten-specific IgG antibodies were purified from the sera of rabbits sensitized to an albumin-acetaldehyde conjugate that had been reduced with sodium cyanoborohydride (N-ethyl-RSA). The N-ethyl-RSA was coupled to an Affi-Gel-10 column to affinity purify the IgG. Liposomes containing N-ethyl-dioleoylphosphatidylethanolamine were fused with isolated hepatocytes, the affinity purified primary IgG antibodies were added, then fluorescein-conjugated second antibodies were added, and antibody binding to hepatocytes was measured by flow cytometry. The fluorescence of these hepatocytes was significantly greater (p less than 0.01) than control hepatocytes prepared with (1) pre-immune primary IgG antibodies with fluorescein-conjugated second antibodies, (2) no primary antibody but with fluorescein-conjugated second antibodies, and (3) no fluorescein-conjugated second antibodies.

Acetaldehyde↗
PubMed1990

Stress initiated during isolation of rat renal proximal tubules limits in vitro survival.

The effects of oxidative damage were assessed in rat proximal tubule fragments (isolated by collagenase perfusion) by monitoring lactate dehydrogenase release (LDH-R) to measure cell viability and thiobarbituric acid (TBA) reactive material to follow oxidative damage. Increasing the oxygen content in the incubation atmosphere from 10 to 95% significantly increased LDH-R and TBA reactants. Addition of butylated hydroxytoluene or deferoxamine (DF) to the medium prevented these changes, but ascorbic acid or mannitol had no positive effect. Lima bean trypsin inhibitor also reduced LDH leakage significantly when added to the medium, but not when added to the perfusion buffers. In contrast, adding DF to the perfusate during tubule isolation produced the most pronounced benefit; net LDH-R after 4 hr was about 10% in tubules prepared this way compared to 20% when DF was omitted. Basal oxygen consumption declined to approximately the same extent as LDH-R increased. Maintenance of nystatin-stimulated respiration, ATP/ADP, GSH content and total adenine nucleotides indicated good cell function. These results suggest that oxidative damage initiated during the tubule isolation procedure limits cell survival but this effect can be counteracted substantially by the addition of DF to the perfusion buffer.

Animals↗
PubMed1989

Cervical cytology in a community laboratory.

A retrospective analysis of the results of 27,801 cervical smears from one year in a community laboratory was undertaken. This represented 23,820 individual patients. Abnormalities were seen in 9.3% of patients. Three point seven percent of patients had benign abnormalities, 5.5% had cervical intraepithelial neoplasia and 0.1% had major abnormalities. The incidence of cervical epithelial abnormality was highest in the 15-34 age group but major abnormalities were seen most often in the 55+ age group. Human papillomavirus was more commonly seen in the youngest age group. The presence of inflammation was reported in 65% of the smears. Thirty percent of smears had no endocervical cells and 0.6% were grossly inadequate. Fifteen percent of patients had repeat smears and 3% of total smears were judged unnecessary. Forty two point six percent of patients less than 55 years of age in the laboratory population base had a smear but only 7.9% of those over 55.

Adolescent↗
PubMed1989

Recurrent ischemia more than 1 year after successful percutaneous transluminal coronary angioplasty. An analysis of the extent and anatomic pattern of coronary disease.

Of 1,181 consecutive patients who underwent successful percutaneous transluminal coronary angioplasty (PTCA) as an initial revascularization procedure and who had at least 1 year of asymptomatic follow-up, 66 (6%) underwent repeat angiography because of recurrent symptoms or evidence of exercise-induced ischemia. Patients who had revascularization procedures within 1 year of PTCA were not included in the analysis. Mean time to recurrent ischemia was 30.8 +/- 17.4 months (range 12-89 months). At follow-up, 47 patients had angina, 13 had atypical chest pain, two had acute myocardial infarction, and four had positive exercise tests without symptoms. No patient showed spontaneous regression in the extent of coronary artery disease (CAD). As compared with the extent of CAD immediately after PTCA, the extent of CAD at follow-up did not change in 26 patients (39%); it increased by one vessel in 30 (45%), by two vessels in seven (11%), and by three vessels in three (5%). The pattern of CAD seen at follow-up compared with that seen after PTCA was as follows: 18 patients (27%), no change; seven (11%), restenosis only; 30 (45%), progression of CAD at other sites only; and 11 (17%), a combination of restenosis and progression of CAD at other sites. The time to recurrence of ischemia was significantly different between those with restenosis only versus those with progression only (20.1 +/- 9.2 vs. 38.3 +/- 18.5 months) (p less than 0.009). Progression of CAD was equally distributed between dilated and nondilated vessels; however, when progression occurred in the PTCA vessel, it was significantly more likely to be distal to the PTCA site (p less than 0.008).

Angioplasty, Balloon, Coronary↗
PubMed1989

Delayed redistribution in thallium 201 SPECT myocardial perfusion studies.

Stress 201Tl myocardial perfusion studies are useful in differentiating viable, reversibly ischemic from infarcted myocardium. A perfusion defect that shows redistribution 2 to 4 h after 201Tl injection is diagnostic of ischemia, while a fixed defect suggests infarction. However, occasional patients with a fixed defect at 4 h have redistribution at 24 h. This study evaluates the frequency and significance of this delayed redistribution with SPECT 201Tl. Patients with either no or incomplete redistribution at 4 h had repeat imaging 18 to 48 h later. Delayed redistribution was seen in 8/26 (31 percent). Four had incomplete and four had no redistribution at 4 h. Delayed redistribution with SPECT 201Tl is more common than generally appreciated, and we recommend delayed images in patients with fixed perfusion defects or incomplete redistribution at 4-h imaging, particularly in patients with previous infarctions for whom a revascularization procedure is being considered.

Adult↗
PubMed1989

Intervention in acute myocardial infarction.

The role of thrombolytic therapy in decreasing mortality and improving left ventricular function has been well established. The role of secondary PTCA is still being defined. Current data support a strategy of performing coronary angiography and elective PTCA only in patients with evidence of ischemia after thrombolytic therapy. Despite the trend away from routine early invasive therapy for acute myocardial infarction, accurate definition of coronary anatomy and assessment of left ventricular function will continue to be vital in the management of these patients and provide a continuing challenge for the cardiac radiographer.

Angioplasty, Balloon, Coronary↗
PubMed1988

Stability of multilead ST-segment "fingerprints" over time after percutaneous transluminal coronary angioplasty and its usefulness in detecting reocclusion.

Multilead ST-segment recordings taken during percutaneous transluminal coronary angioplasty (PTCA) could function as an individualized noninvasive template or "fingerprint," useful in evaluating transient ischemic episodes after leaving the catheterization laboratory. To evaluate the reproducibility of such ST-segment patterns over time, these changes were analyzed in patients grouped according to the time between occlusion and reocclusion. For the patients in group 1, the study required comparing their "fingerprints" in repeat balloon inflation during PTCA (reocclusion in less than 1 hour), for those in group 2, comparing ST "fingerprints" during PTCA with ST changes during spontaneous early myocardial infarction (reocclusion in 24 hours) and in group 3, comparing ST "fingerprints" with ST changes during repeat PTCA for restenosis greater than 1 month after the initial PTCA. The ST "fingerprints" among the 20 patients in group 1 were identical in 14 cases (70%) and clearly related in another 4 (20%). Of the 23 patients in group 2, 12 (52%) had the same and 8 (35%) had related patterns. Of 19 patients in group 3, 8 (42% had the same pattern and 8 (42%) had related patterns. Thus, ST fingerprints were the same or clearly related with reocclusion in the same patient from less than 1 hour to greater than 1 month after initial occlusion in 87% of patients overall, in 90% in less than 1 hour, in 87% in less than 24 hours and in 84% greater than 1 month later. Multilead pattern ST-segment "fingerprints" may serve as a noninvasive marker for detecting site-specific reocclusion.

Aged↗