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1.
Ann Oncol ; 21(4): 707-716, 2010 Apr.
Article in English | MEDLINE | ID: mdl-19815652

ABSTRACT

BACKGROUND: The present article reports the updated survival outcome of the 200 patients enrolled in the Southern Italy Cooperative Oncology Group 9908 trial, which compared 12 weekly cycles of cisplatin-epirubicin-paclitaxel (PET) with 4 triweekly (once every 3 weeks) cycles of epirubicin-paclitaxel (ET) in patients with locally advanced breast cancer (LABC). METHODS: The effects of treatment, pathologically documented response (pathological response), pre- and post-treatment biomarkers on relapse-free survival (RFS), distant metastasis-free survival (DMFS), and overall survival (OS) are analysed. RESULTS: At a median follow-up of 74 (range 48-105 months) months, the 5-year RFS, DMFS, and OS were 64 % versus 53% (P = 0.11), 73% versus 55% (P = 0.04), and 82% versus 69% (P = 0.07) in PET and ET, respectively. At multivariate analysis, after adjusting treatment effect for pretreatment biomarkers, PET independently predicted better DMFS (P = 0.018) and OS (P = 0.03), whereas the impact on RFS was of borderline significance (0.057). PET treatment was significantly better than ET treatment only in high-grade or highly proliferating tumours. The better outcome in PET arm was the results of both the higher rate of patients with optimal pathological response and the lower rate of patients with biologically aggressive residual tumour. CONCLUSIONS: The PET weekly regimen significantly improves both DMFS and OS in LABC patients, compared with the triweekly ET combination. The therapeutic advantage is limited to patients with highly aggressive tumours.


Subject(s)
Antineoplastic Combined Chemotherapy Protocols/administration & dosage , Breast Neoplasms/diagnosis , Breast Neoplasms/drug therapy , Carcinoma/diagnosis , Carcinoma/drug therapy , Adult , Aged , Algorithms , Breast Neoplasms/mortality , Breast Neoplasms/surgery , Carcinoma/mortality , Carcinoma/surgery , Cisplatin/administration & dosage , Combined Modality Therapy , Disease Progression , Drug Administration Schedule , Epirubicin/administration & dosage , Etoposide/administration & dosage , Female , Follow-Up Studies , Humans , Italy , Middle Aged , Paclitaxel/administration & dosage , Preoperative Care , Taxoids/administration & dosage
2.
Eur Respir J ; 34(2): 417-24, 2009 Aug.
Article in English | MEDLINE | ID: mdl-19648519

ABSTRACT

The current study was designed to determine whether the nonspecific in vivo airway hyperresponsiveness of the inbred Fisher F-344 rat strain is associated with impaired spontaneous relaxation of airway smooth muscle. Strips of the posterior portion of the trachea from 10 adult Fisher and 10 adult Lewis rats were electrically stimulated at pH 7.4, 2.5 mM Ca(2+)concentration, at 37 degrees C. Both isotonic and isometric relaxations of tracheal smooth muscle (TSM) were investigated. Half time for isotonic relaxation at preload was markedly prolonged in Fisher rats (8.33+/-3.21 s) compared with Lewis rats (3.53+/-0.54 s; p<0.001). Maximum lengthening velocity at preload and peak rate of isometric tension decline were significantly decreased in Fisher rats compared with Lewis rats. The ratio of shortening velocity to lengthening velocity at preload, as well as the ratio of the isometric peak rates of tension development to tension decline were higher in Fisher rat TSM than in Lewis rat TSM. These differences were associated with a six-fold higher expression of myosin light chain kinase in Fisher rats than in Lewis rats. In Fisher rats, these results suggest that innate airway hyperresponsiveness is associated with both a reduced level and a slower rate of TSM spontaneous relaxation, promoting maintenance of airway constriction.


Subject(s)
Bronchial Hyperreactivity/physiopathology , Muscle Relaxation , Muscle, Smooth/pathology , Trachea/pathology , Animals , Calcium/metabolism , Electrophysiology/methods , Hydrogen-Ion Concentration , Male , Myosin-Light-Chain Kinase/metabolism , Rats , Rats, Inbred F344 , Rats, Inbred Lew , Species Specificity , Time Factors
3.
Nat Clin Pract Cardiovasc Med ; 6(3): 240-9, 2009 Mar.
Article in English | MEDLINE | ID: mdl-19234502

ABSTRACT

BACKGROUND: Cardiac tissue engineering might be useful in treatment of diseased myocardium or cardiac malformations. The creation of functional, biocompatible contractile tissues, however, remains challenging. We hypothesized that coupling of arginine-glycine-aspartic acid-serine (RGD+) adhesion peptides would improve cardiomyocyte viability and differentiation and contractile performance of collagen-cell scaffolds. METHODS: Clinically approved collagen scaffolds were functionalized with RGD+ cells and seeded with cardiomyocytes. Contractile performance, cardiomyocyte viability and differentiation were analyzed at days 1 and 8 and/or after culture for 1 month. RESULTS: The method used for the RGD+ cell-collagen scaffold coupling enabled the following features: high coupling yields and complete washout of excess reagent and by-products with no need for chromatography; spectroscopic quantification of RGD+ coupling; a spacer arm of 36 A, a length reported as optimal for RGD+-peptide presentation and favorable for integrin-receptor clustering and subsequent activation. Isotonic and isometric mechanical parameters, either spontaneous or electrostimulated, exhibited good performance in RGD+ constructs. Cell number and viability was increased in RGD+ scaffolds, and we saw good organization of cell contractile apparatus with occurrence of cross-striation. CONCLUSIONS: We report a novel method of engineering a highly effective collagen-cell scaffold based on RGD+ peptides cross-linked to a clinically approved collagen matrix. The main advantages were cell contractile performance, cardiomyocyte viability and differentiation.


Subject(s)
Biocompatible Materials , Cell Differentiation/drug effects , Myocardial Contraction/drug effects , Oligopeptides/chemistry , Cell Adhesion/drug effects , Collagen , Humans , Tissue Engineering
4.
Transfus Clin Biol ; 13(3): 181-95, 2006 Sep.
Article in French | MEDLINE | ID: mdl-16996767

ABSTRACT

Blood is the most available and admissible of substitutive human products. However, neither an attitude favourable to its therapeutic transfusion nor a positive representation of blood is sufficient to predict an effective gift or an absence of fear to its reception. In this article, we synthesize various research of social psychology aiming at understanding what are these different bloods that the subjects accept or refuse to communicate. In order to give a new interpretation of the problems of the social communication of substitutive human product, we will evoke practice, attitudes and representations of blood starting from a model including seven factors of representation of biological materials - this model reflecting dimensions on which is based the intersubjective social network in which is carried out the therapeutic communication of blood.


Subject(s)
Attitude to Health , Blood Donors/psychology , Blood Transfusion/psychology , Life , Psychology, Social , Altruism , Attitude of Health Personnel , Communication , Fees and Charges , Health Personnel/psychology , Humans , Motivation , Organ Transplantation/psychology , Patient Acceptance of Health Care/psychology , Patients/psychology , Philosophy , Self Concept , Socioeconomic Factors , Symbolism , Tissue Donors/psychology , Treatment Refusal
5.
J Mol Cell Cardiol ; 32(9): 1631-45, 2000 Sep.
Article in English | MEDLINE | ID: mdl-10966826

ABSTRACT

The development of cardiac hypertrophy during neonatal life and in adults implies different processes. The angiotensin II (Ang II) system is involved in the development of cardiac hypertrophy in adults, but its role in neonates remains unclear. The aim of this study was to estimate the influence of increased hemodynamic load on the developmental pattern of the AT1/AT2 receptor expression in the heart. Two-day-old rats submitted to abdominal aortic constriction (AC) or sham operation were sacrificed 2 h, and 1, 3, and 8 days after surgery. Ang II was evaluated in sera and immunohistology was performed to define the cardiac hypertrophy process. The Ang II receptor subtypes 1 and 2 were quantified at the receptor and mRNA levels by(125)I-Ang II binding and RT-PCR, respectively. Ang II content in sera increased transiently 2 h after surgery in the AC group. In sham-operated, AT1 and AT2 decreased throughout the period studied at both mRNA and receptor levels. However, the AT1 mRNA level decrease was more pronounced than that of AT2 (by 57% and 27%, respectively). AC not only prevented the postnatal decrease in AT mRNA level but resulted in an increase in AT1 mRNA 8 days after surgery (P<0.05). Besides in the AC groups, AT2 mRNA levels but not those of AT1 mRNA were linearly correlated with the left ventricular mass. At the receptor level, a significant transient (1 day after surgery) increase in both AT1 and AT2 was observed. In conclusion, our data demonstrated that imposition of pressure overload soon after birth altered the pattern of AT receptor expression.


Subject(s)
Animals, Newborn/physiology , Heart/physiology , Receptors, Angiotensin/physiology , Animals , Aortic Valve Stenosis , Blood Pressure/physiology , Female , Male , Rats , Rats, Wistar
6.
Cardiovasc Res ; 46(2): 346-55, 2000 May.
Article in English | MEDLINE | ID: mdl-10773239

ABSTRACT

OBJECTIVES: Fibrosis is a classical feature of cardiac hypertrophy. To date changes within the basal lamina during normal and pathological cardiac growth have been poorly investigated. The goal of the present study was to determine if the expression of the muscle specific subunit of merosin (laminin alpha2 chain) together with that of fibronectin (FN) is modified in the diseased human heart. Laminin alpha2 chain expression was also investigated during physiological and pathological cardiac growth in the rat. METHODS: In ten normal human hearts and ten hearts with idiopathic dilated cardiomyopathy (IDCM), the laminin-alpha2 and FN mRNA levels were quantified by slot-blot using total RNA and the protein distribution was analysed using an immunofluorescence approach. In Wistar rats, laminin alpha2 and FN mRNA expression was analyzed using RNase protection assay (RPA) and slot-blot assays. RESULTS: The amount of laminin alpha2 mRNA did not vary in normal and pathological human hearts whereas it was significantly decreased in renovascular hypertensive rats (-20%) P<0.05 versus normal tissue). The amount of fibronectin mRNA increased in IDMC patients (x2, P<0.05 versus normal tissue), but was unchanged in hypertensive rats. A negative correlation was found between the cardiac laminin-alpha2 level and the age of the patients whatever the cardiac status. During postnatal development in the rat, a similar decrease in cardiac laminin-alpha2 level was observed between 3 and 30 weeks of age. Finally, the immunofluorescent approach failed to detect any alteration in laminin alpha2 distribution within the human myocardium. CONCLUSION: These data indicate that an imbalance between myocyte hypertrophy and the level of laminin-alpha2 might contribute to alterations in sarcolemmal properties, which occur during the development of cardiac hypertrophy and its transition to cardiac failure.


Subject(s)
Cardiomyopathy, Dilated/metabolism , Extracellular Matrix/metabolism , Laminin/metabolism , Myocardium/metabolism , Analysis of Variance , Animals , Female , Fetal Heart/metabolism , Fibronectins/genetics , Fibronectins/metabolism , Fluorescent Antibody Technique , Gene Expression , Heart/growth & development , Humans , Hypertension, Renovascular , Laminin/genetics , Male , Protein Isoforms/genetics , Protein Isoforms/metabolism , RNA, Messenger/analysis , Rats , Rats, Wistar
7.
Am J Physiol Endocrinol Metab ; 278(2): E330-9, 2000 Feb.
Article in English | MEDLINE | ID: mdl-10662718

ABSTRACT

During muscle development, an isozymic transition of the glycolytic enzyme enolase occurs from the embryonic and ubiquitous alphaalpha-isoform to the muscle-specific betabeta-isoform. Here, we demonstrate a stimulatory role of thyroid hormones on these two enolase genes during rat development in hindlimb muscles and an inhibitory effect on the muscle-specific enolase gene in cardiac muscle. In hindlimb muscles the ubiquitous alpha-transcript level is diminished by hypothyroidism, starting at birth. On the contrary, the more abundant muscle-specific beta-transcript is insensitive to hypothyroidism before establishment of the functional diversification of fibers and is greatly decreased thereafter. Our data support the hypothesis of a role of thyroid hormones in coordinating the expressions of contractile proteins and metabolic enzymes during muscle development. The subcellular localization of isoenolases, established here, is not modified by hypothyroidism. Our results underline the specificity of action of thyroid hormones, which modulate differentially two isozymes in the same muscle and regulate, in opposite directions, the expression of the same gene in two different muscles.


Subject(s)
Gene Expression Regulation, Enzymologic/drug effects , Heart/growth & development , Isoenzymes/genetics , Muscle Development , Muscle, Skeletal/growth & development , Phosphopyruvate Hydratase/genetics , Thyroid Hormones/pharmacology , Animals , Hypothyroidism/chemically induced , Hypothyroidism/enzymology , Isoenzymes/metabolism , Methylthiouracil/pharmacology , Muscle, Skeletal/enzymology , Myocardium/enzymology , Myosin Heavy Chains/genetics , Phosphopyruvate Hydratase/metabolism , RNA, Messenger/analysis , Rats , Rats, Wistar , Triiodothyronine/pharmacology
8.
Mol Cell Biochem ; 184(1-2): 101-5, 1998 Jul.
Article in English | MEDLINE | ID: mdl-9746315

ABSTRACT

It has been well established that the cytoskeleton is an essential modulator of cell morphology and motility, intracytoplasmic transport and mitosis, however cytoskeletal linkage to the organelles has not been unequivocally demonstrated. Indeed, cytoskeleton appears to be essential in determining and modulating gene phenotype as a function of cellular environment. According to recent studies, the organization of the cytoskeleton network together with associated protein(s) could be essential in regulating mitochondrial function and particularly the permeability of the mitochondrial outer membrane to ADP. The aim of this chapter is to summarize the main properties of the cytoskeletal environment of mitochondria and the possible role(s) of this network in mitochondrial function in myocytes.


Subject(s)
Cytoskeleton/physiology , Mitochondria/physiology , Adenosine Diphosphate/metabolism , Animals , Cell Membrane Permeability/physiology , Membrane Proteins/physiology , Microscopy, Electron , Microtubule-Associated Proteins/physiology , Muscles/ultrastructure , Rats
9.
J Chemother ; 10(6): 476-83, 1998 Dec.
Article in English | MEDLINE | ID: mdl-9876057

ABSTRACT

Between 1990 and 1995, 87 patients with locally advanced breast cancer were treated with initial chemotherapy consisting of 3-4 cycles of epirubicin and then with surgery, radiotherapy and chemotherapy. All patients with positive or unknown estrogen receptor status were administered tamoxifen. A complete response was observed in 9 patients and a partial response in 64. At a mean follow-up of 29.22 months, 25 patients had died of metastatic disease, and 48 patients are disease-free. 54% patients are alive at 5 years. Statistical analysis confirmed that neither age, menopausal status, size of the primary tumor nor histology seemed to influence the Disease Free and Overall Survival. Improved survival was observed in patients with negative lymph nodes and positive receptor status. The presence of a positive receptor status may be correlated with conserved integrity of hormone sensitivity and with a good response to the hormone therapy.


Subject(s)
Antibiotics, Antineoplastic/therapeutic use , Antineoplastic Agents, Hormonal/therapeutic use , Breast Neoplasms/therapy , Carcinoma/therapy , Epirubicin/therapeutic use , Tamoxifen/therapeutic use , Adolescent , Adult , Aged , Breast Neoplasms/pathology , Carcinoma/pathology , Combined Modality Therapy , Drug Administration Schedule , Female , Humans , Mastectomy, Modified Radical , Middle Aged , Neoadjuvant Therapy , Prognosis , Radiotherapy, Adjuvant , Receptors, Estrogen/analysis , Survival Analysis , Treatment Outcome
10.
Circulation ; 92(4): 904-11, 1995 Aug 15.
Article in English | MEDLINE | ID: mdl-7641373

ABSTRACT

BACKGROUND: Fibronectin (FN), a component of the extracellular matrix, influences cellular migration and differentiation. It is a prominent component of the extracellular matrix of normal arteries and is thought to play an important role in the pathogenesis of restenosis after angioplasty. FN exists in multiple forms that arise from a single RNA transcript that can be alternatively spliced. EIIIA- and EIIIB-containing FN mRNAs predominate in the embryo, whereas in the adult, most of the normal tissue FN lacks these domains. Since few data were available concerning pattern of expression of the different alternatively spliced forms of FN mRNA in arteries after endoluminal injury, we analyzed the expression of EIIIA and EIIIB FN isoforms at different times after experimental angioplasty. METHODS AND RESULTS: The spatial and temporal alterations in FN expression were studied in an in vivo model of endothelial denudation in the rabbit aorta and iliac artery by a combination of immunochemistry and in situ hybridization methods. Alternatively spliced forms of FN EIIIA and EIIIB were detected in the media and the adventitia of both types of vessels 24 to 48 hours after injury. Two weeks after injury, EIIIA and EIIIB mRNAs were found to accumulate within the luminal layers of the neointima. The cellular form of FN protein was not found until 2 weeks after the injury and accumulated in the inner part of the neointima. CONCLUSIONS: These data demonstrate that FN upregulation is an early and long-lasting process after arterial injury. These results suggest that the induction of the embryonic FN isoforms may be involved in the restenotic process that follows balloon denudation of arteries.


Subject(s)
Arteries/injuries , Arteries/metabolism , Catheterization , Fetus/metabolism , Fibronectins/genetics , RNA, Messenger/metabolism , Animals , Aorta/injuries , Aorta/physiology , Blotting, Northern , Gene Expression , Iliac Artery/physiology , In Vitro Techniques , Isomerism , Male , Rabbits , Reference Values
11.
J Mol Cell Cardiol ; 27(5): 1225-34, 1995 May.
Article in English | MEDLINE | ID: mdl-7473781

ABSTRACT

The number of dihydropyridine and ryanodine receptors (DHP-R and RyR) has been measured in control and hypertrophied ventricles from rats, guinea pigs and ferrets to determine whether these two channels contribute to the alterations in excitation-contraction coupling (ECC), and in Ca2+ transient during compensated cardiac hypertrophy. We found that ventricular hypertrophy did not change the density of DHP-R. Mild hypertrophy did not alter the density of RyR in the rat but decreased it in the guinea-pig and in the ferret (30% and 36%, respectively). Severe hypertrophy decreased the density of RyR by 20% in the rat and by 34% in the guinea-pig. Therefore, the decrease is greater in ferret and guinea-pig hearts than in rat heart. We conclude that the sarcoplasmic reticulum (SR) Ca2+ release channels but not the L-type Ca2+ channels could contribute to the slowing of intracellular Ca2+ movements and to the reduced velocity of shortening of the hypertrophied hearts. We suggest that, in the guinea pig and ferret hearts which express only the beta myosin heavy chain (MHC) isoform, the reduced velocity of shortening during hypertrophy is related to the decrease in RyR density, whereas in the rat, it is regulated primarily via a shift in the MHC isoform, except in severe hypertrophy in which the moderate decrease in RyR would also be involved.


Subject(s)
Calcium Channels/metabolism , Hypertrophy, Left Ventricular/metabolism , Hypertrophy, Right Ventricular/metabolism , Muscle Proteins/metabolism , Myocardium/metabolism , Adaptation, Physiological , Animals , Calcium/metabolism , Calcium Channels, L-Type , Female , Ferrets , Guinea Pigs , Male , Microsomes/metabolism , Myocardial Contraction , Myosins/metabolism , Rats , Ryanodine/metabolism , Ryanodine Receptor Calcium Release Channel , Sarcolemma/metabolism , Sarcoplasmic Reticulum/metabolism
13.
Lab Invest ; 71(4): 552-9, 1994 Oct.
Article in English | MEDLINE | ID: mdl-7967511

ABSTRACT

BACKGROUND: Fibronectin, an extracellular matrix protein, exists as multiple isoforms expressed in a time- and cell-dependent manner. Since the developmental pattern of fibronectin expression has not been determined in the heart, the first issue of this study was to investigate the expression of total fibronectin mRNA as well as its isoforms during cardiac ontogeny. In adults, pressure overload induces a shift towards the fetal form of proteins expressed by either muscle or nonmuscle cardiac cells. Fetal forms of fibronectin mRNA being found in smooth and nonmuscle cardiac cells soon after imposition of pressure overload, the pattern of fibronectin expression during the development of pathological growth was analyzed to determine whether the two conditions of cardiac growth resulted in an identical pattern of fibronectin expression. EXPERIMENTAL DESIGN: Total RNA were isolated from rat heart (a) during in utero and postnatal life and (b) at varying periods of time after imposition of a pressure overload induced by coarctation of the thoracic aorta in 25-day-old rats. Fibronectin-EIIIA+ or -EIIIB+ and total fibronectin mRNAs were quantitated by reverse transcription-polymerase chain reactions and dot-blot analysis, respectively. RESULTS: Fibronectin mRNA, abundant in the 14-day-old fetal heart, rapidly decreased during cardiac physiologic growth (> 5-fold); no changes in the fibronectin mRNA level was observed during the development of pressure-induced cardiac hypertrophy. The percentages of fibronectin transcripts containing EIIIA or EIIIB exons, very high in the early fetal heart (> 45%), harmoniously decreased during cardiac maturation (< 12%). Aortic coarctation resulted in an early, transient (12 to 48 hours) and preferential expression of fibronectin-EIIIA+ mRNA (approximately 40%). CONCLUSIONS: In rat heart, neither physiologic nor pressure-induced growth requires increased amounts of fibronectin mRNA but the growth conditions specifically modulated the fibronectin pre-mRNA splicing.


Subject(s)
Cardiomegaly/genetics , Cardiomegaly/pathology , Fibronectins/genetics , Heart/growth & development , RNA Splicing , RNA, Messenger/genetics , Animals , Base Sequence , Cardiomegaly/metabolism , Exons , Female , Fibronectins/analysis , Fibronectins/metabolism , Isomerism , Molecular Sequence Data , Myocardium/chemistry , Myocardium/metabolism , Myocardium/pathology , Polymerase Chain Reaction , RNA, Messenger/analysis , RNA, Messenger/metabolism , Rats , Rats, Wistar , Time Factors
14.
J Biol Chem ; 269(2): 1541-7, 1994 Jan 14.
Article in English | MEDLINE | ID: mdl-8288620

ABSTRACT

To determine if an altered expression of the Na,K-ATPase alpha isoform genes is responsible for an observed increase in cardiac glycoside sensitivity in compensatory hypertrophy, we performed Northern and slot blot analyses of RNA and specific immunological detection of Na,K-ATPase isoforms in rat hearts from normal and pressure overload-treated animals induced by abdominal aortic constriction. During the early phase of hypertrophy, the only alteration is a decrease in the alpha 2 mRNA isoform. In the compensated hypertrophied heart, the levels of the predominant alpha 1 isoform (mRNA and protein) and the beta 1 subunit mRNA are unchanged. In contrast, the alpha 2 isoform (mRNA and protein) is decreased by 35% and up to 61-64% in mild (< 55%) and severe (> 55%) hypertrophy, respectively. The alpha 3 isoform (mRNA and protein), which is extremely low in adult heart, is increased up to 2-fold during hypertrophy but accounts for only approximately equal to 5% of the total alpha isoform mRNA. These findings demonstrate that, in cardiac hypertrophy, the three alpha isoforms of the Na,K-ATPase are independently regulated and that regulation occurs at a pretranslational level. The pattern of expression in hypertrophied adult heart is similar to that of the neonatal heart where the inverse regulation between the alpha 2 and alpha 3 ouabain high affinity isoforms has been reported. This suggests that distinct regulatory mechanisms controlling Na,K-ATPase isoform expression may, at least in part, be involved in the sensitivity to cardiac glycosides.


Subject(s)
Cardiomyopathy, Hypertrophic/genetics , Sodium-Potassium-Exchanging ATPase/metabolism , Animals , Blotting, Western , Gene Expression , Isoenzymes/genetics , Isoenzymes/metabolism , Microsomes/enzymology , Myocardial Contraction , Myosins/genetics , Ouabain/pharmacology , RNA, Messenger/genetics , Rats , Rats, Wistar , Sodium-Potassium-Exchanging ATPase/antagonists & inhibitors , Sodium-Potassium-Exchanging ATPase/genetics
15.
Am J Physiol ; 265(1 Pt 1): C62-71, 1993 Jul.
Article in English | MEDLINE | ID: mdl-8338139

ABSTRACT

Cardiac myocytes isolated from adult rats and cultured for up to 5 days in a defined serum- and 3,5,3'-triiodothyronine-(T3) free medium were processed for in situ hybridization using [35S]cRNA probes specific for alpha- or beta-myosin heavy chain (MHC) mRNAs. A computer-assisted image analysis system was used to quantitate the hybridization signals within individual myocytes (100 cells/experimental point). The method was validated by comparison with dot-blot quantitation. The mean alpha-MHC mRNA density per cell decreased by 50% (P < 0.01) after 2 days in culture and remained stable thereafter, whereas the relative amount of beta-MHC mRNA did not increase until day 5. Addition of 10(-12) M T3 to the culture medium for 2 or 3 days was sufficient to maintain alpha-MHC mRNA levels similar to the day 0 values, whereas 10(-9) M T3 was necessary to completely inhibit beta-MHC mRNA expression. The independent analysis of myocytes exhibiting different morphological phenotypes with time in culture demonstrated that rounded myocytes contain relatively more alpha-MHC mRNA and were as sensitive to T3 as their rod-shaped counterparts. Their beta-MHC RNA content was similar to that found in rod-shaped cells and was still depressed by T3. In conclusion, we show that 1) physiological doses of T3 are sufficient to maintain in vitro a MHC phenotype close to that observed in vivo in adult, 2) the dose responsiveness of adult myocytes to T3 differs from that reported in neonatal myocytes, and 3) the alpha-MHC mRNA content and the T3 sensitivity of spheroidal myocytes imply that there is no alteration in their state of maturation.


Subject(s)
Myocardium/metabolism , Myosins/genetics , RNA, Messenger/metabolism , Thyroid Hormones/pharmacology , Animals , Cells, Cultured , In Situ Hybridization , Myocardium/cytology , Myosins/chemistry , Rats , Time Factors , Tissue Distribution
16.
Eur J Cancer ; 29A(2): 195-8, 1993.
Article in English | MEDLINE | ID: mdl-7678495

ABSTRACT

17 patients with breast carcinoma were studied with 57-cobalt-bleomycin scintigraphy. Scans showed increased tumour uptake in all patients. Results expressed as percentage of the injected dose (ID) normalised by the size of the tumour region (% ID/pixel) showed higher tumour uptake in patients with T3-T4 breast carcinomas (n = 5) than in patients with T1-T2 breast cancer (n = 12) (8.4 +/- 0.55 x 10(-3) vs. 5.25 +/- 1.71 x 10(-3)% ID/pixel, respectively, P < 0.05). An inverse correlation between tumour uptake of 57-cobalt-bleomycin and progesterone receptor concentration was also found in all tumours tested (r = -0.60, P < 0.05, n = 10) and was confirmed in the group of patients with T2 breast carcinomas (r = -0.89, P < 0.05, n = 6). We conclude that a quantitative analysis of 57-cobalt-bleomycin uptake can give additional information suitable for the presurgical characterisation of a tumour.


Subject(s)
Bleomycin/pharmacokinetics , Breast Neoplasms/metabolism , Carcinoma, Intraductal, Noninfiltrating/metabolism , Carcinoma/metabolism , Adult , Aged , Breast Neoplasms/diagnostic imaging , Carcinoma/diagnostic imaging , Carcinoma, Intraductal, Noninfiltrating/diagnostic imaging , Cobalt Radioisotopes , Female , Humans , Middle Aged , Radionuclide Imaging , Receptors, Estrogen/analysis , Receptors, Progesterone/analysis
17.
Kidney Int Suppl ; 37: S45-50, 1992 Jun.
Article in English | MEDLINE | ID: mdl-1385839

ABSTRACT

The basis for impaired left ventricular function of hearts in moderate to severe stages of hypertrophy and congestive heart failure remains uncertain. At the cellular level, the mechanisms governing the movements of calcium in the myocardium are actually depressed and might at least in part account for the slowing of the maximum shortening velocity and the impaired relaxation. These alterations of membrane proteins seem particularly important in species where the slowing of Vmax cannot be a consequence of the myosin heavy chain shift. They lead to an unstable equilibrium of calcium homeostasis and to calcium overload in heart failure. On the other hand, the enhanced density and remodeling of collagen in the hypertrophied heart, which would depend on elevation in circulating aldosterone, impair myocardial stiffness with diastolic dysfunction and lead to altered pumping capacity of the heart. Disturbances of calcium metabolism and matrix collagen remodeling enhance early afterdepolarizations and arrhythmias.


Subject(s)
Collagen/metabolism , Hypertension/metabolism , Membrane Proteins/metabolism , Animals , Calcium/metabolism , Cardiomegaly/etiology , Cardiomegaly/metabolism , Cardiomegaly/physiopathology , Homeostasis/physiology , Humans , Hypertension/complications , Hypertension/physiopathology
18.
Cardiovasc Res ; 25(10): 875-80, 1991 Oct.
Article in English | MEDLINE | ID: mdl-1660790

ABSTRACT

STUDY OBJECTIVE: The aim was to determine if the adaptational process of the cardiac calcium channel to pressure overload observed in rat heart also occurs in species characterised by a higher sensitivity to external calcium than in the rat. This adaptation occurs via a maintained density of dihydropyridine receptors and calcium current in hypertrophied rat heart. DESIGN: The guinea pig was chosen and the dissociation constant (Kd), association and dissociation rate constants (k+1,k-1), and maximal number (Bmax) of the dihydropyridine receptors were measured through binding of [3H]PN 200-110 to crude sarcolemma fractions from control and hypertrophied guinea pig left ventricle. EXPERIMENTAL MATERIAL: Hypertrophy of the left ventricle was obtained by stenosis of the abdominal aorta in guinea pigs. MEASUREMENTS AND MAIN RESULTS: Hypertrophy reached at least 50% in 15% of the surviving animals. No significant differences in the binding of [3H]PN 200-110 to the dihydropyridine receptor were observed between control and hypertrophied left ventricle microsomal preparations: Kd = 1.59(SEM 0.22) and 1.17(0.36) nM; Bmax = 225(18) and 213(4) fmol.mg-1 of protein; k-1 = 2.30(0.26) and 2.00(0.13) min-1 x 10(-2); k+1 = 3.8(0.7) and 3.5(0.3) nM-1.min-1 x 10(-2) respectively. CONCLUSIONS: In guinea pig as in rat, the total number of dihydropyridine receptors per left ventricle increased proportionately to the hypertrophy. This is consistent with an unchanged density of the cardiac Ca2+ channels in the hypertrophied guinea pig heart as previously shown in hypertrophied rat heart.


Subject(s)
Cardiomegaly/metabolism , Myocardium/chemistry , Receptors, Nicotinic/analysis , Adaptation, Physiological/physiology , Animals , Calcium Channel Blockers/metabolism , Calcium Channels , Cardiomegaly/pathology , Cardiomegaly/physiopathology , Female , Guinea Pigs , Heart Ventricles/chemistry , Myocardium/pathology , Rats , Sarcolemma/chemistry
19.
FEBS Lett ; 285(1): 135-8, 1991 Jul 08.
Article in English | MEDLINE | ID: mdl-1829688

ABSTRACT

We investigate the possibility that alterations in the calcium movements of the hypertrophied rat heart might involve sarcoplasmic reticulum (SR) ryanodine receptors. A decreased receptor density was observed with severe hypertrophy (0.26 +/- 0.05 and 0.35 +/- 0.06 pmol/mg protein and 170 and 366 receptors/micron2 of SR in 50-80% hypertrophy and control, respectively); however, the total number of receptors per left ventricle was unchanged. The dissociation constant (0.7 nM) was similar in both hypertrophied and control left ventricles. Thus the decreased density of the ryanodine receptors may participate in altered calcium movements in hypertrophied rat heart.


Subject(s)
Cardiomegaly/metabolism , Hypertension, Pulmonary/metabolism , Receptors, Cholinergic/metabolism , Sarcoplasmic Reticulum/metabolism , Animals , Binding Sites , Calcium/metabolism , Kinetics , Male , Microsomes/metabolism , Myocardium/metabolism , Rats , Rats, Inbred Strains , Ryanodine Receptor Calcium Release Channel
20.
Am J Physiol ; 254(3 Pt 2): H517-24, 1988 Mar.
Article in English | MEDLINE | ID: mdl-2964793

ABSTRACT

The mechanical properties of detergent-treated skinned fibers from pressure-overloaded rat and guinea pig hearts have been compared with those of sham-operated animals. Overload was obtained 4 wk after abdominal aortic stenosis, an intervention that increases ventricular weight by 56% in rats and 57% in guinea pigs. The time constant (T, in ms) for tension recovery after a quick stretch was significantly lower in normal guinea pig than in rat. It was lengthened by the process of overload in both species, but this was much more pronounced in rats where T increases by 84% than in guinea pig where it was only slightly augmented by 14% for a doubling of the heart weight. By contrast the maximum tension obtained at pCa 4.5, the stiffness, and the sensitivity to calcium of the fibers were unmodified by chronic overload. In rat, not in guinea pig, a slight decrease in MgATP sensitivity was also observed, whereas no change in creatine kinase efficiency was seen. These results are interpreted as indicating that the slowing of the turnover rate of cross-bridge cycling explains the drop in shortening velocity observed on papillary muscles in rat but not in guinea pig; a species in which membrane modifications must be predominant in the process of adaptation.


Subject(s)
Guinea Pigs/physiology , Heart/physiopathology , Hypertension/physiopathology , Rats/physiology , Adenosine Triphosphate/pharmacology , Animals , Biomechanical Phenomena , Calcium/pharmacology , Cardiomegaly/etiology , Cardiomegaly/pathology , Heart/drug effects , Hypertension/complications , Male , Muscles/drug effects , Muscles/physiopathology , Myocardial Contraction/drug effects , Rats, Inbred Strains
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