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PubMed1995

Changes in pulmonary mechanics and gas exchange after thoracentesis on patients with inversion of a hemidiaphragm secondary to large pleural effusion.

The present study was designed to test whether there was a significant improvement in pulmonary function and arterial blood oxygenation after therapeutic thoracentesis on patients with inversion of a hemidiaphragm due to pleural effusion. In 21 patients with inversion of a hemidiaphragm because of a pleural effusion, we studied the changes in pulmonary mechanics and gas exchange that occurred in 24 h after removal of 600 to 2,700 mL of fluid by thoracentesis. There was a small but significant increase in the forced expiratory volume in 1 s (FEV1) and forced vital capacity (FVC) (p < 0.001). The alveolar-arterial oxygen gradient (P[A-a]O2) and partial pressure of arterial oxygen (PaO2) showed a significant increase (p < 0.001), but there was no change in partial pressure of arterial carbon dioxide (PaCO2). In the present study, all patients with a large pleural effusion had inversion of a hemidiaphragm documented by chest sonography, and that was an important factor to observe significant improvement in pulmonary mechanics and gas exchange.

Adult↗
PubMed2002

Occurrence of transient U-wave inversion during vasospastic anginal attack is not related to the direction of concurrent ST-segment shift.

STUDY OBJECTIVES: We sought to assess the incidence of transient U-wave inversion during vasospasm of the left anterior descending coronary artery (LAD) with ST-segment depression as opposed to that with ST-segment elevation. DESIGN: Retrospective study. SETTING: Cardiology division of acute-care hospitals. PATIENTS: We studied 49 patients with vasospastic angina whose vasospasm was induced in the LAD, not in the left circumflex coronary artery, by intracoronary injection of acetylcholine. MEASUREMENTS AND RESULTS: The ECG traces obtained during acetylcholine-induced vasospasm of the LAD were examined. Based on the direction of ST-segment shift, the patients were categorized into two groups: the ST-segment elevation group (n = 27) and the depression group (n = 22). There were no differences in age, gender, or cardiovascular risk factors between the two groups. The distribution of the spastic site in the LAD was also similar. A total reduction in luminal diameter during a provoked attack was more often observed in the ST-segment elevation group than in the ST-segment depression group (37% vs 9%, p = 0.02). Collateral circulation to the LAD was found in only one patient in each group. There were no differences between the two groups in heart rate, systolic BP, and double product of heart rate and systolic BP during the attack. The incidence of acetylcholine-induced anginal attack with U-wave inversion in the ST-segment depression group was nearly as high as that in the ST-segment elevation group (77% vs 78%, p > 0.99). CONCLUSIONS: The development of transient U-wave inversion during vasospasm of the LAD induced by intracoronary injection of acetylcholine does not depend on the magnitude of myocardial ischemia as judged by the direction of ST-segment shift.

Acetylcholine↗
PubMed1975

Ventricular inversion associated with normally related great vessels.

A patient with ventricular inversion with normally related great vessels and double inlet left ventricle is presented. the patient also showed features of Down's syndrome. Association of ventricular inversion with normally related great vessels is rare and leads to a basic functional state like that of complete transposition of great vessels derived from the connections between the ventricles and great vessels. The association of ventricular inversion with Down's syndrome observed in the case reported represents a rarity.

Aorta↗
PubMed1996

The relationship between serum levels of interleukin-6 and thyroid hormone during the follow-up study in children with nonthyroidal illness: marked inverse correlation in Kawasaki and infectious disease.

Our previous study demonstrated that the serum IL-6 correlated inversely with serum T3 and the T3/T4 ratio in children with acute respiratory infection during the acute phase of illness. To investigate whether serum IL-6 inversely correlates with serum thyroid hormone during not only the active stage of the disease but also in the follow-up period in nonthyroidal illness, we measured serum levels of IL-6, T3 and T4 in 31 children from the acute to the convalescent phase. They were divided into 3 groups; 7 patients with Kawasaki disease, 16 patients with infectious disease and 8 patients with non-inflammatory disease. In the follow-up of patients with Kawasaki disease, a marked inverse relationship was observed between serum IL-6 and T3 (r = -0.844, P < 0.001) or the T3/T4 ratio (r = -0.863, P < 0.001). Serum T4 showed a weak but significant negative correlation with serum IL-6 (r = -0.474, P = 0.035) only in this situation. There was also a significant negative correlation between serum IL-6 and T3 (r = -0.582, P < 0.001) or the T3/T4 ratio (r = -0.660, P < 0.001) during the follow-up of children with infectious disease. In the follow-up study of patients with non-inflammatory disease, however, no significant relationships were observed between serum thyroid hormones and IL-6. IL-6 may be one important factor involved in the decrease in the serum T3 level and the T3/T4 ratio in patients with nonthyroidal illness particularly characterized by strong inflammation and activation of the immune system as observed in Kawasaki and infectious disease.

Adolescent↗
PubMed1999

Inverse distribution of serum sodium and potassium in uncontrolled inpatients with diabetes mellitus.

It has been reported that there is an inverse relationship between serum sodium (Na) and potassium (K) levels in patients with diabetic coma. The present study was undertaken to determine whether such an inverse relation depends upon plasma glucose levels in diabetic patients for their glycemic control. We examined two hundred and fifty-two patients with diabetes mellitus admitted to our hospital during the one-year period to control their plasma glucose levels, except for those having nephropathy or liver dysfunction. Serum Na and K, plasma glucose, and serum and urinary C-peptide levels were determined. There was a negative correlation between serum Na levels and fasting plasma glucose (FPG), and, conversely, a positive correlation between serum K levels and FPG. The changes were more evident in the patients with insulin-dependent diabetes mellitus than those with non-insulin-dependent diabetes mellitus. There was an inverse relation between serum Na and K levels and it was profoundly dependent upon plasma glucose levels in all the diabetic patients before tight control of their glycemic levels. The disorder may be based on the movement of electrolytes between intra- and extracellular spaces, dependent on the impaired insulin action as well as hyperosmolality.

Adult↗
PubMed2001

Circulating IGF binding protein-1 is inversely associated with leptin in non-obese men and obese postmenopausal women.

OBJECTIVE: Hyperleptinaemia and hyperinsulinaemia interrelate to insulin-like growth factor binding protein 1 (IGFBP-1), and disturbances in the growth hormone-IGF-I axis are linked to obesity and cardiovascular diseases. However, whether the association between leptin and the GH-IGF-I axis is altered with increasing obesity is not known. We therefore examined the relationship between leptin, IGF-I, IGFBP-1, insulin and proinsulin in men and women with or without obesity in a population study. DESIGN AND SUBJECTS: Healthy subjects (n=158; 85 men and 73 pre- and postmenopausal women) from the Northern Sweden MONICA (Monitoring of Trends and Determinants in Cardiovascular Disease) population were studied with a cross-sectional design. METHODS: Anthropometric measurements (body mass index (BMI) and waist circumference) and oral glucose tolerance tests were performed. Radioimmunoassays were used for the analyses of leptin, IGF-I and IGFBP-1, and ELISAs for specific insulin and proinsulin. RESULTS: Leptin inversely correlated to IGFBP-1 in non-obese men (P<0.05) and obese postmenopausal women (P<0.05). In contrast, leptin did not correlate to IGF-I. IGFBP-1 was also significantly associated with proinsulin in non-obese men (P<0.01) and non-obese premenopausal women (P<0.05). The association between leptin and IGFBP-1 was lost after adjustment for insulin. In multivariate analyses taking measures of adiposity into account, low proinsulin, and IGF-I in combination with old age, but not leptin, predicted high IGFBP-1 levels. CONCLUSIONS: Leptin was inversely associated with IGFBP-1 in non-obese men and obese postmenopausal women, and proinsulin was inversely associated with IGFBP-1 in non-obese men and premenopausal women. However, these associations were lost with increasing central obesity in men and premenopausal women and after control for insulin. Therefore, this study suggests (i) that leptin is of minor importance for regulation of IGFBP-1 levels and (ii) that the insulin resistance syndrome is characterised by an altered relationship between leptin, IGFBP-1 and insulin.

Adipose Tissue↗
PubMed2005

Inverse relationship between 15-lipoxygenase-2 and PPAR-gamma gene expression in normal epithelia compared with tumor epithelia.

15-Lipoxygenase-2 (15-LOX-2) synthesizes 15-S-hydroxyeicosatetraenoic acid (15-S-HETE), an endogenous ligand for the nuclear receptor, peroxisome proliferator-activated receptor-gamma (PPAR-gamma). Several studies have described an inverse relationship between 15-LOX-2 and PPAR-gamma expression in normal versus tumor samples. To systematically determine if this is a ubiquitous phenomenon, we used a variety of epithelial and nonepithelial cells and some tissues to further evaluate the extent of this inverse relationship. The levels of mRNA or protein were measured by reverse transcriptase polymerase chain reaction or Western gray level intensity, whereas distribution was determined by in situ hybridization or immunofluorescence. 15-S-HETE was measured by liquid chromatography/tandem mass spectrometry. Normal epithelial cells/samples generally expressed high levels of 15-LOX-2 along with the enzyme product 15-S-HETE, but both levels were reduced in cancer cells/samples. In contrast, most cancer cells expressed high levels of PPAR-gamma mRNA and protein, which were absent from normal epithelial cells. Overall, the inverse relationship between these two genes was primarily restricted to epithelial samples. Forced expression of PPAR-gamma reduced 15-LOX-2 protein levels in normal cells, whereas forced expression of 15-LOX-2 in tumor cells suppressed PPAR-gamma protein levels. These results suggest that feedback mechanisms may contribute to the loss of 15-LOX-2 pathway components, which coincide with an increase in PPAR-gamma in many epithelial cancers.

Arachidonate 15-Lipoxygenase↗
PubMed1992

Pericentric inversion of chromosome 9 in prenatal diagnosis and infertility.

In order to evaluate the relation between pericentric inversion of chromosome 9 (inv(9)) and clinical problems, the characteristics of inv(9) were investigated on the basis of chromosomal analyses of fetuses and infertile couples. The incidence of such inversion in fetuses with parents having an offspring who suffered from various clinical problems was significantly higher than the basic incidence obtained in fetuses karyotyped by reason of advanced maternal age. In the chromosomal examination of the parents whose fetuses were diagnosed as inv(9), it was revealed that either parent might be the carrier. Furthermore, in the inv(9) carrying fetuses, the number of females was significantly greater than that of males. Analysis of infertile couples revealed that the incidence of such inversion in males was significantly higher than the basic incidence mentioned above. Moreover, infertile couples with an inv(9) carrier showed a significantly higher incidence of intrauterine fetal death, compared with infertile couples with a translocation carrier or those in which the etiology was unknown. These results indicate that inv(9) may often cause clinical problems in offspring of the carrier and infertility with unknown mechanisms related to sex.

Chromosome Aberrations↗
PubMed2004

Sex inversion of sexually immature honeycomb grouper (Epinephelus merra) by aromatase inhibitor.

Previous studies have shown that estrogen plays an important role in sex change of protogynous honeycomb grouper, and that the treatments with aromatase inhibitor (AI) cause estrogen depletion and complete sex inversion of pre-spawning females into functional males. In the present study, we examined whether AI causes sex inversion of sexually immature females. Female honeycomb groupers were implanted with various doses of Fadrozole (0, 100, 500 and 1000 microg/fish) in the non-breeding season, and resultant changes in the gonadal structures and the plasma levels of sex steroid hormones (estradiol-17 beta, E2; testosterone, T; 11-ketotestosterone, 11-KT) were examined three months after implantation. Vehicle-implanted groups did not change sex, while 100 and 500 microg AI-implanted groups had turned into transitionals with intersex gonad. In contrast, the highest dose receiving group exhibited both transitional and male phases. Transitional phase gonad had atretic oocytes and spermatogenic germ cells at the late stages of spermatogenesis, while male phase testis contained spermatozoa accumulated in the seminiferous tubules. All males released sperm upon slight pressure on the abdomen. In the AI-implanted fish, plasma levels of E2 decreased in a dose-dependent manner, while the levels of 11-KT were high in the highest dose receiving group. Present results suggest that estrogen plays an important role in sex change of protogynous honeycomb grouper, and that treatments with AI potentially inhibits endogenous E2 production in vivo, causing oocyte degeneration and subsequently the sex inversion from female to male. The Fadrozole could be an important tool for manipulating the sex of hermaphrodite fishes.

Animals↗
PubMed2006

The homeostasis model assessment-insulin resistance index is inversely associated with serum carotenoids in non-diabetic subjects.

BACKGROUND: Carotenoids may reduce the risk for diabetes mellitus, but little is known about the association of insulin resistance with serum carotenoids in non-diabetic subjects. This study aimed to investigate whether the homeostasis model assessment-insulin resistance (HOMA-IR) index would be lower in the presence of high serum carotenoid concentrations in non-diabetic subjects. METHODS: A total of 812 subjects (256 males and 556 females) who had received health examinations in 2003 participated in the study. The associations of the serum-carotenoid concentrations and HOMA-IR were evaluated cross-sectionally. The multivariate-adjusted geometric means of HOMA-IR by the tertiles of the serum carotenoid concentration were calculated after adjusting for age, body mass index, systolic blood pressure, total cholesterol, triacylglycerols, current tobacco use, regular alcohol intake, exercise habits and total energy intake. Associations among high HOMA-IR (3.0+mUxmmol/L2) across tertiles of serum carotenoid concentration were assessed by tests for logistic regression analysis. RESULTS: In male subjects, the multivariate adjusted geometric mean of HOMA-IR was inversely associated with the serum beta-cryptoxanthin concentrations. In female subjects, an inverse association of the serum carotenoid concentration and HOMA-IR was observed in lycopene, beta-cryptoxanthin, and zeaxanthin. The confounding factor-adjusted odds ratios (OR) for high HOMA-IR on the highest tertiles of serum alpha-carotene, beta-carotene, beta-cryptoxanthin, and zeaxanthin were 0.18 [95% confidence interval (CI): 0.06-0.52], 0.22 (95% CI: 0.07-0.67), 0.34 (95% CI: 0.12-0.96), and 0.30 (95% CI: 0.11-0.79), respectively, in male subjects. On the other hand, in female subjects, the adjusted OR for high HOMA-IR on the highest tertiles of serum lycopene and beta-cryptoxanthin were 0.39 (95% CI: 0.21-0.73) and 0.51 (95% CI: 0.28-0.95), respectively. CONCLUSIONS: The serum antioxidant carotenoids were inversely associated with HOMA-estimated insulin resistance in non-diabetic subjects.

Adult↗
PubMed2004

Sparse inverse of covariance matrix of QTL effects with incomplete marker data.

Gametic models for fitting breeding values at QTL as random effects in outbred populations have become popular because they require few assumptions about the number and distribution of QTL alleles segregating. The covariance matrix of the gametic effects has an inverse that is sparse and can be constructed rapidly by a simple algorithm, provided that all individuals have marker data, but not otherwise. An equivalent model, in which the joint distribution of QTL breeding values and marker genotypes is considered, was shown to generate a covariance matrix with a sparse inverse that can be constructed rapidly with a simple algorithm. This result makes more feasible including QTL as random effects in analyses of large pedigrees for QTL detection and marker assisted selection. Such analyses often use algorithms that rely upon sparseness of the mixed model equations and require the inverse of the covariance matrix, but not the covariance matrix itself. With the proposed model, each individual has two random effects for each possible unordered marker genotype for that individual. Therefore, individuals with marker data have two random effects, just as with the gametic model. To keep the notation and the derivation simple, the method is derived under the assumptions of a single linked marker and that the pedigree does not contain loops. The algorithm could be applied, as an approximate method, to pedigrees that contain loops.

Journal Article↗
PubMed1996

Distal ileocolic intussusception: another cause of inversion of superior mesenteric vessels in infants.

OBJECTIVE: Inversion of the superior mesenteric vessels is associated with various conditions. The purpose of this study was to prospectively evaluate the position of these vessels in infants with idiopathic ileocolic intussusception. SUBJECTS AND METHODS: Abdominal sonography was performed before and after reduction of ileocolic intussusception in 16 infants. RESULTS: In 14 infants with ileocolic intussusception proximal to the splenic flexure, the relationship of the superior mesenteric vessels was normal (superior mesenteric vein to the right ventral side of superior mesenteric artery). Inversion of the superior mesenteric vessels (superior mesenteric vein to the left of the superior mesenteric artery) was found in two patients with distal ileocolic intussusception (head of the intussusceptum at the sigmoid colon or rectum). After reduction, the relationship of these vessels was normal in all 16 infants. CONCLUSION: Inversion of the superior mesenteric vessels is sometimes caused by distal ileocolic intussusception in infants.

Colon, Sigmoid↗
PubMed1998

Usefulness of optimized gadolinium-enhanced fast fluid-attenuated inversion recovery MR imaging in revealing lesions of the brain.

OBJECTIVE: The purpose of this study was to compare the contrast enhancement of lesions of the brain revealed by gadolinium-enhanced optimized fast fluid-attenuated inversion recovery (FLAIR) MR imaging with that of lesions on gadolinium-enhanced optimized T1-weighted spin-echo MR imaging. SUBJECTS AND METHODS: Using computer simulations, we optimized the fast FLAIR parameters (TR, TEeff, and inversion time) and the T1-weighted spin-echo parameters (TR and TE) to provide maximum difference in signal intensity between enhancing lesions of the brain and white matter. Seventy-six consecutive patients referred for single-dose gadolinium-enhanced MR imaging of the brain underwent both optimized techniques, which were matched for spatial resolution, bandwidth, and number of excitations. The gadolinium-enhanced fast FLAIR and T -weighted spin-echo MR images were evaluated independently by two observers for number and size of enhancing lesions and for the degree of gray-white matter differentiation. Contrast-to-noise ratios were measured for enhancing lesions 1.0 cm or larger in diameter using 8 x 8 pixel regions of interest in the enhancing lesions and normal white matter. RESULTS: The most revealing parameters for fast FLAIR MR imaging proved to be a TR of 1500 msec, an inversion time of 683 msec, and a TEeff of 16 msec. For T1-weighted spin-echo MR imaging, the optimized parameters were a TR of 550 msec and a TE of 16 msec. In 28 patients, we saw enhancing lesions of the brain with at least one MR imaging technique. More lesions were seen on the T1-weighted spin-echo sequence (n = 141) than on the fast FLAIR sequence (n = 94) (p < .03). Gray-white matter differentiation was significantly better on the fast FLAIR sequence (p < .001). Contrast-to-noise ratios of enhancing lesions were greater on the T1-weighted spin-echo sequence (p < .001). CONCLUSION: In this study, optimized gadolinium-enhanced conventional T1-weighted spin-echo MR imaging proved superior to gadolinium-enhanced fast FLAIR MR imaging in revealing lesions of the brain.

Adult↗
PubMed2002

Intraportal venous flow distribution: evaluation with single breath-hold ECG-triggered three-dimensional half-Fourier fast spin-echo MR imaging and a selective inversion-recovery tagging pulse.

OBJECTIVE: The purpose of this study was to evaluate the intraportal blood flow distribution from splenic and superior mesenteric veins with an unenhanced MR angiographic technique using single breath-hold ECG-triggered three-dimensional (3D) half-Fourier fast spin-echo sequence and selective inversion-recovery tagging pulse. SUBJECTS AND METHODS: Seventeen healthy volunteers were included in this prospective study. After obtaining regular single breath-hold ECG-triggered 3D half-Fourier fast spin-echo images without applying a tagging pulse, we placed the selective inversion-recovery tagging pulse on the superior mesenteric vein (TAG-A), the splenic vein (TAG-B), or on both (TAG-C) to study the inflow correlation of tagged or marked blood into the portal vein. MR images were evaluated subjectively by three reviewers. RESULTS: On MR images obtained using the TAG-A pulse to suppress the signal flow from the superior mesenteric vein into the portal vein, the most common pattern of signal loss was observed on the right half of the main portal vein (8/17 subjects). Conversely, on the MR images obtained using the TAG-B pulse, signal loss of the left half of the main portal vein was the most common pattern (11/17 subjects). Signal reduction from the splenic venous flow in the left portal vein was significantly greater than that from the superior mesenteric venous flow (p<0.05). CONCLUSION: The unenhanced MR angiographic technique using single breath-hold ECG-triggered 3D half-Fourier fast spin echo with selective inversion-recovery tagging pulse has the potential to assess the intraportal blood flow distribution from the splenic and superior mesenteric veins.

Adult↗
PubMed1993

Treatment of the inversion ankle sprain: comparison of different modes of compression and cryotherapy.

Relatively few studies have been performed to examine the effectiveness of different methods of treatment for the inversion ankle sprain. In this study, restoration of function following a grade II inversion sprain was compared among 34 subjects who received one of three methods of treatment, each of which incorporated an Air-Stirrup brace. The methods included uniform compression provided by elastic tape, focal compression provided by a U-shaped device, and focal compression with simultaneous cryotherapy. Although the results failed to demonstrate statistical significance at the .05 level (p = .055), the two groups that received focal compression attained each of nine levels of function in fewer days than the group that received uniform compression. The results of this study indicate that focal compression appears beneficial, but increased frequency and duration of cryotherapy does not appear to enhance the rate of recovery following an inversion ankle sprain.

Adolescent↗
PubMed1999

Relationship between ankle invertor H-reflexes and acute swelling induced by inversion ankle sprain.

STUDY DESIGN: Single group, post-test design using the uninvolved lower extremity as the experimental control. OBJECTIVES: To determine relationships between ankle swelling and flexor digitorum longus and peroneus longus H-reflex amplitude and latency. BACKGROUND: Primary capsuloligamentous injury, neural injury, and joint effusion and swelling may contribute to H-reflex changes following inversion ankle sprain. The relationship between ankle swelling and invertor or evertor H-reflexes has not been reported. METHODS AND MEASURES: Fifteen subjects with acute grade I or II inversion ankle sprains (mean +/- SD) 6.5 +/- 3 days after onset participated in this study. Swelling was estimated using a tape measure and the figure-of-eight girth assessment method. H-reflexes were determined using standard techniques. Paired t-tests were used to compare mean differences in ankle girth (swelling) and ankle invertor or evertor H-reflex amplitude and latency between the involved and uninvolved limbs. Pearson product moment correlations were used to assess relationships between swelling and H-reflex variables. RESULTS: Involved limb ankle girth was increased with respect to the uninvolved limb (1.5 +/- 0.9 cm) and the involved ankle flexor digitorum longus latency was delayed (0.72 +/- 0.7 ms). There was a moderate positive association (r = 0.73) between the latency delay in the involved ankle flexor digitorum longus and swelling. There were no significant differences in H-reflex amplitude and peroneus longus latency between ankles. CONCLUSIONS: Grade I or II inversion sprains and the related swelling appear to delay involved ankle flexor digitorum longus latency to a greater extent than peroneus longus latency. Clinicians need to direct greater attention to the ankle invertors when designing and implementing ankle rehabilitation programs, particularly during the swelling management phase of treatment.

Acute Disease↗
PubMed1991

On the biomagnetic inverse problem in the case of multiple dipoles.

Series of Monte Carlo simulations have been carried out which were based on the assumption that two dipoles with a distance of 0.5-2 cm are located in a homogeneous semi-infinite volume conductor (depth 3 cm), and that the magnetic field component perpendicular to the surface of the volume conductor is recorded by means of a magnetometer with infinitesimal coil diameter. Moving-dipole models (all parameters time-dependent), rotating-dipole models (dipole locations fixed, dipole orientation and amplitudes time-dependent) as well as fixed-dipole models (dipole locations and orientations fixed, amplitudes time-dependent) were considered. The algorithm used to retrieve the model parameters from the simulated field distributions (biomagnetic inverse procedure) was based on a transformation of the standard least-squares fit procedure into a minimization procedure with respect to the nonlinear parameters (dipole locations and orientations), which was solved iteratively by means of the Fletcher-Powell algorithm. It was found that the resolving power of the biomagnetic inverse procedure is highly dependent on the relative orientation of the two dipoles, the temporal overlap of the dipole moments, and the correlation of successive samples of the superimposed noise. The results obtained in this study suggest that the resolving power of the biomagnetic inverse procedure for conditions typically found in the case of auditory evoked magnetic fields is not better than 2 cm for the moving-dipole approach, and not better than 1 cm for the fixed-dipole approach, provided that no additional a priori information is available. In practice, the situation is probably even worse since the depth of the generators is usually larger than assumed in this study.

Algorithms↗
PubMed1991

Selenium-dependent glutathione peroxidase expression is inversely related to estrogen receptor content of human breast cancer cells.

The absence of estrogen receptors (ER) in human breast tumors has been associated with a poorer prognosis compared to patients with ER positive breast cancer. Previous studies from our laboratory have shown that a multidrug resistant human breast cancer cell line selected for resistance to Adriamycin (ADR) exhibited markedly increased expression of both the pi class glutathione S-transferase (GST-pi) and the selenium-dependent glutathione peroxidase. These studies also revealed that the ER status was inversely related to the expression of GST-pi in six human breast cancer cell lines and primary tumor specimens. In the present study, we have examined the relationship between ER status and several biological properties of these cells, including their levels of glutathione peroxidase (GSH-Px) and catalase expression, their capacity to generate toxic hydroxyl radicals (degrees OH) by redox cycling of ADR, and their sensitivities to the cytotoxic effects of ADR and the oxidant, H2O2. Our results show that expression of GSH-Px, but not catalase, is inversely related to the ER status in these cell lines. Formation of the degree OH induced by treatment of cells with ADR was inversely proportional to the GSH-Px activity in these cell lines, and thus directly related to the ER status. Sensitivity of these cells to ADR or to H2O2, however, was not consistently related to ER status, GSH-Px, or catalase activity, or to ADR induced degree OH radical formation. These results indicate that these parameters are not predictive of cellular susceptibility to oxidative damage in these cell lines under the conditions studied.

Blotting, Northern↗