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1.
Sci Rep ; 13(1): 1014, 2023 Jan 18.
Article in English | MEDLINE | ID: mdl-36653377

ABSTRACT

In a single crystalline Si particle, we observed a huge amplification of the Raman peak at 521 cm-1. With an AFM microscope, coupled with a Micro-Raman spectrometer, we investigate a single Si particle at wavelengths of 532 nm, 633 nm, and 785 nm. As observed by transmission electron microscopy, it has an octahedral shape of 150 nm in size. Thermal effects were detected on the Raman peak when the laser radiation, trapped inside, determines the heating of the particle up to its fusion. In these cases, the Raman peak splits into two components, the first at the crystal position and the other shifted at a lower value. The data permit the identification of the amplification mechanism of the Raman peak as trapped radiation moving forward and backwards into the particle. The thermal effects are attributed to phonon confinement and reduced thermal exchange with the surrounding. The present results are discussed in light of local order, the uncertainty principle, and phonon dispersion curves, and corroborated by shape-dependent simulation of absorption, scattering, and extinction behaviour.

2.
Hum Reprod ; 37(5): 954-968, 2022 05 03.
Article in English | MEDLINE | ID: mdl-35220429

ABSTRACT

STUDY QUESTION: Is it safe to perform controlled ovarian stimulation (COS) for fertility preservation before starting anticancer therapies or ART after treatments in young breast cancer patients? SUMMARY ANSWER: Performing COS before, or ART following anticancer treatment in young women with breast cancer does not seem to be associated with detrimental prognostic effect in terms of breast cancer recurrence, mortality or event-free survival (EFS). WHAT IS KNOWN ALREADY: COS for oocyte/embryo cryopreservation before starting chemotherapy is standard of care for young women with breast cancer wishing to preserve fertility. However, some oncologists remain concerned on the safety of COS, particularly in patients with hormone-sensitive tumors, even when associated with aromatase inhibitors. Moreover, limited evidence exists on the safety of ART in breast cancer survivors for achieving pregnancy after the completion of anticancer treatments. STUDY DESIGN, SIZE, DURATION: The present systematic review and meta-analysis was carried out by three blinded investigators using the keywords 'breast cancer' and 'fertility preservation'; keywords were combined with Boolean operators. Eligible studies were identified by a systematic literature search of Medline, Web of Science, Embase and Cochrane library with no language or date restriction up to 30 June 2021. PARTICIPANTS/MATERIALS, SETTING, METHODS: To be included in this meta-analysis, eligible studies had to be case-control or cohort studies comparing survival outcomes of women who underwent COS or ART before or after breast cancer treatments compared to breast cancer patients not exposed to these strategies. Survival outcomes of interest were cancer recurrence rate, relapse rate, overall survival and number of deaths. Adjusted relative risk (RR) and hazard ratio (HR) with 95% CI were extracted. When the number of events for each group were available but the above measures were not reported, HRs were estimated using the Watkins and Bennett method. We excluded case reports or case series with <10 patients and studies without a control group of breast cancer patients who did not pursue COS or ART. Quality of data and risk of bias were assessed using the Newcastle-Ottawa Assessment Scale. MAIN RESULTS AND THE ROLE OF CHANCE: A total of 1835 records were retrieved. After excluding ineligible publications, 15 studies were finally included in the present meta-analysis (n = 4643). Among them, 11 reported the outcomes of breast cancer patients who underwent COS for fertility preservation before starting chemotherapy, and 4 the safety of ART following anticancer treatment completion. Compared to women who did not receive fertility preservation at diagnosis (n = 2386), those who underwent COS (n = 1594) had reduced risk of recurrence (RR 0.58, 95% CI 0.46-0.73) and mortality (RR 0.54, 95% CI 0.38-0.76). No detrimental effect of COS on EFS was observed (HR 0.76, 95% CI 0.55-1.06). A similar trend of better outcomes in terms of EFS was observed in women with hormone-receptor-positive disease who underwent COS (HR 0.36, 95% CI 0.20-0.65). A reduced risk of recurrence was also observed in patients undergoing COS before neoadjuvant chemotherapy (RR 0.22, 95% CI 0.06-0.80). Compared to women not exposed to ART following completion of anticancer treatments (n = 540), those exposed to ART (n = 123) showed a tendency for better outcomes in terms of recurrence ratio (RR 0.34, 95% CI 0.17-0.70) and EFS (HR 0.43, 95% CI 0.17-1.11). LIMITATIONS, REASONS FOR CAUTION: This meta-analysis is based on abstracted data and most of the studies included are retrospective cohort studies. Not all studies had matching criteria between the study population and the controls, and these criteria often differed between the studies. Moreover, rate of recurrence is reported as a punctual event and it is not possible to establish when recurrences occurred and whether follow-up, which was shorter than 5 years in some of the included studies, is adequate to capture late recurrences. WIDER IMPLICATIONS OF THE FINDINGS: Our results demonstrate that performing COS at diagnosis or ART following treatment completion does not seem to be associated with detrimental prognostic effect in young women with breast cancer, including among patients with hormone receptor-positive disease and those receiving neoadjuvant chemotherapy. STUDY FUNDING/COMPETING INTEREST(S): Partially supported by the Associazione Italiana per la Ricerca sul Cancro (AIRC; grant number MFAG 2020 ID 24698) and the Italian Ministry of Health-5 × 1000 funds 2017 (no grant number). M.L. acted as consultant for Roche, Pfizer, Novartis, Lilly, AstraZeneca, MSD, Exact Sciences, Gilead, Seagen and received speaker honoraria from Roche, Pfizer, Novartis, Lilly, Ipsen, Takeda, Libbs, Knight, Sandoz outside the submitted work. F.S. acted as consultant for Novartis, MSD, Sun Pharma, Philogen and Pierre Fabre and received speaker honoraria from Roche, Novartis, BMS, MSD, Merck, Sun Pharma, Sanofi and Pierre Fabre outside the submitted work. I.D. has acted as a consultant for Roche, has received research grants from Roche and Ferring, has received reagents for academic clinical trial from Roche diagnostics, speaker's fees from Novartis, and support for congresses from Theramex and Ferring outside the submitted work. L.D.M. reported honoraria from Roche, Novartis, Eli Lilly, MSD, Pfizer, Ipsen, Novartis and had an advisory role for Roche, Eli Lilly, Novartis, MSD, Genomic Health, Pierre Fabre, Daiichi Sankyo, Seagen, AstraZeneca, Eisai outside the submitted work. The other authors declare no conflict of interest. The funding organizations had no role in the design and conduct of the study; collection, management, analysis, and interpretation of the data; preparation, review, or approval of the manuscript and decision to submit the manuscript for publication. REGISTRATION NUMBER: N/A.


Subject(s)
Breast Neoplasms , Cancer Survivors , Fertility Preservation , Breast Neoplasms/drug therapy , Female , Humans , Neoplasm Recurrence, Local , Pregnancy , Retrospective Studies
3.
ESMO Open ; 6(6): 100300, 2021 12.
Article in English | MEDLINE | ID: mdl-34775302

ABSTRACT

BACKGROUND: Knowledge is growing on the safety of assisted reproductive techniques (ART) in cancer survivors. No data exist, however, for the specific population of breast cancer patients harboring germline BRCA1/2 pathogenic variants. PATIENTS AND METHODS: This is a multicenter retrospective cohort study across 30 centers worldwide including women diagnosed at ≤40 years with stage I-III breast cancer, between January 2000 and December 2012, harboring known germline BRCA1/2 pathogenic variants. Patients included in this analysis had a post-treatment pregnancy either achieved through use of ART (ART group) or naturally (non-ART group). ART procedures included ovulation induction, ovarian stimulation for in vitro fertilization or intracytoplasmic sperm injection, and embryo transfer under hormonal replacement therapy. RESULTS: Among the 1424 patients registered in the study, 168 were eligible for inclusion in the present analysis, of whom 22 were in the ART group and 146 in the non-ART group. Survivors in the ART group conceived at an older age compared with those in the non-ART group (median age: 39.7 versus 35.4 years, respectively). Women in the ART group experienced more delivery complications compared with those in the non-ART group (22.1% versus 4.1%, respectively). No other apparent differences in obstetrical outcomes were observed between cohorts. The median follow-up from pregnancy was 3.4 years (range: 0.8-8.6 years) in the ART group and 5.0 years (range: 0.8-17.6 years) in the non-ART group. Two patients (9.1%) in the ART group experienced a disease-free survival event (specifically, a locoregional recurrence) compared with 40 patients (27.4%) in the non-ART group. In the ART group, no patients deceased compared with 10 patients (6.9%) in the non-ART group. CONCLUSION: This study provides encouraging safety data on the use of ART in breast cancer survivors harboring germline pathogenic variants in BRCA1/2, when natural conception fails or when they opt for ART in order to carry out preimplantation genetic testing.


Subject(s)
Breast Neoplasms , Adult , BRCA1 Protein/genetics , Breast Neoplasms/genetics , Female , Germ Cells , Humans , Neoplasm Recurrence, Local/etiology , Pregnancy , Reproductive Techniques, Assisted/adverse effects , Retrospective Studies
4.
Hum Reprod ; 36(2): 381-389, 2021 01 25.
Article in English | MEDLINE | ID: mdl-33289029

ABSTRACT

STUDY QUESTION: What is the risk of recurrence in young breast cancer survivors who undergo ARTs following completion of anticancer treatment? SUMMARY ANSWER: ART in breast cancer survivors does not appear to have a negative impact on disease-free survival. WHAT IS KNOWN ALREADY: In healthy women, fertility treatment does not increase the risk of developing breast cancer. At the time of breast cancer diagnosis and before starting anticancer treatments, several studies have shown the safety of performing ART. However, the safety of ART in breast cancer survivors following completion of anticancer treatment remains under-investigated. In general, breast cancer survivors are counselled to avoid any hormonal treatment but there are limited data available on the effect of short exposure to high oestradiol levels during ART. The largest study in this regard included 25 breast cancer survivors exposed to ART and did not show a detrimental effect of ART on patient survival. Hence, taking into account that pregnancy after breast cancer does not affect cancer prognosis, defining the safety of ART in breast cancer survivors remains a priority. STUDY DESIGN, SIZE, DURATION: We conducted a retrospective multicentric matched cohort study including a cohort of breast cancer survivors who underwent ART (exposed patients) between January 2006 and December 2016. Exposed patients who were eligible for the study were matched according to known breast cancer prognostic factors. Matched breast cancer survivors did not undergo ART (non-exposed patients) and were disease-free for a minimum time that was not less than the time elapsed between breast cancer diagnosis and first ART for the matched ART-exposed patients. PARTICIPANTS/MATERIALS, SETTING, METHODS: Data were retrieved from all survivors who had been diagnosed with breast cancer in eight participating centres at an age of ≤40 years, without metastasis, ongoing pregnancy, pre-existing neoplasia or ovarian failure. ART included ovarian stimulation for IVF/ICSI, clomiphene citrate treatment and hormone replacement therapy for embryo transfer. Data were collected from an oncological database for the selection of breast cancer patients in the non-exposed group. Exposed patients were matched (1:2) for germline BRCA status, tumour stage, anticancer treatment and age, whenever feasible. Matched groups were compared at baseline according to characteristics using conditional logistic regression. Kaplan-Meier curves were constructed to compare time to recurrence between groups, with the time of ART as starting point that has been adjusted in the non-exposed group. The analyses were performed using Stata IC/15.1. MAIN RESULTS AND THE ROLE OF CHANCE: A total of 39 breast cancer patients in the ART group were eligible for the analysis and were matched with 73 controls. There was no statistical difference between the two groups for the presence of BRCA mutation, tumour characteristics, use of (neo)adjuvant chemotherapy and of adjuvant endocrine therapy. Exposed patients were younger than non-exposed patients (mean age 31.8 vs 34.3 years, respectively; P < 0.001). In the ART group, 89.7% were nulliparous at diagnosis compared to 46.6% of controls (P < 0.001). ART was performed at a mean age of 37.1 years old, after a median time of 4.1 years following breast cancer diagnosis (range: 1.5-12.5). Median anti-Müllerian hormone at the time of ART was 0.28 ng/ml (range: 0-4.4) and median serum oestradiol peak level was 696.5 pg/ml (range: 139.7-4130). Median follow-up time from first attempt of ART was 4.6 years (range: 2.4-12.5) in the ART group. Adjusted follow-up time for the non-exposed group was 6.9 years (range: 1.1-16.5 years) (P = 0.004). In the ART group, 59% of patients had a pregnancy after breast cancer compared to 26% in the non-exposed patients (P = 0.001). Breast cancer relapsed in 7.7% versus 20.5% women in the ART and non-exposed groups, respectively (hazard ratio 0.46, 95% CI 0.13-1.62, P = 0.23). Median time to relapse was 1.3 (range: 0.3-2.7) years versus 4.5 (range: 0.4-11.1) years after ART and adjusted time in the ART and non-exposed groups, respectively (P = 0.14). LIMITATIONS, REASONS FOR CAUTION: Although this is the first and largest multicentric study addressing the impact of ART on breast cancer recurrence to provide data on oestrogen exposure, only a small number of patients could be included. This reflects the reluctance of breast cancer survivors and/or oncologists to perform ART, and highlights the need for a prospective data registry to confirm the safety of this approach. This would offer the possibility for these patients, who are at a high risk of infertility, to fully benefit from ART. WIDER IMPLICATIONS OF THE FINDINGS: Although recent studies have proven that pregnancy after breast cancer has no detrimental impact on prognosis, counselling patients about the safety of ART remains challenging. Our study provides reassuring data on the use of ART in breast cancer survivors with favourable prognostic factors, for when natural conception fails. STUDY FUNDING/COMPETING INTEREST(S): M.C. and I.D. are funded by FNRS, Télévie-FNRS and Fonds Erasme. M.D.V. is a CooperSurgical scientific advisory board member and receives lecture fees for MSD, Gedeon-Richter and Ferring, outside the submitted work. M.L. has acted as a consultant for Roche and Novartis and has received honoraria from Theramex, Roche, Lilly, Pfizer, Novartis and Takeda, outside the submitted work. I.D. has acted as a consultant for ROCHE and has received speaker's fees from Novartis, outside the submitted work. E.d.A. has received honoraria and is a Roche/GNE, Novartis, SeaGen and Zodiac scientific advisory board member, has received travel grants from Roche/GNE and GSK/Novartis, and has received research grants from Roche/GNE, Astra-Zeneca, GSK/Novartis and Servier, outside the submitted work. A.D. is a recipient of a research grant from Ferring Pharmaceuticals and receives lecture and/or consultancy fees from Merck, Gedeon-Richter and Ferring Pharmaceuticals, outside the submitted work. The remaining authors have no conflicts of interest to declare. TRIAL REGISTRATION NUMBER: N/A.


Subject(s)
Breast Neoplasms , Cancer Survivors , Adult , Breast Neoplasms/drug therapy , Cohort Studies , Female , Humans , Male , Neoplasm Recurrence, Local , Pregnancy , Prospective Studies , Retrospective Studies
5.
Ultrasound Obstet Gynecol ; 52(6): 776-783, 2018 Dec.
Article in English | MEDLINE | ID: mdl-25130705

ABSTRACT

OBJECTIVES: To evaluate postmortem ultrasound (PM-US) for minimally invasive autopsy, and to demonstrate its feasibility, sensitivity and specificity, as compared with conventional autopsy, in detecting major congenital abnormalities. METHODS: Over a 19-month study period from 1 March 2012 to 30 September 2013, we recruited from a referral hospital 88 consecutive fetuses, at 11-40 weeks' gestation, which had undergone termination, miscarriage or intrauterine fetal death. We performed PM-US using different transducers and compared the data with those from conventional autopsy. The latter was performed, according to the Societé Francaise de Foetopathologie (France) guidelines, by experienced perinatal pathologists who were blinded to the ultrasound data. RESULTS: Complete virtual autopsy by ultrasound was possible in 95.5% of the cases. The sensitivity of PM-US for detecting brain abnormalities was 90.9% (95% CI, 58.7-99.8%) and the specificity was 87.3% (95% CI, 75.5-94.7%). In 20% of cases, a neuropathological examination was not possible due to severe maceration. The sensitivity for detection of thoracic abnormalities was 88.9% (95% CI, 65.3-98.6%) and the specificity was 92.8% (95% CI, 84.1-97.6%), and the sensitivity for detection of abdominal anomalies was 85.7% (95% CI, 57.2-98.2%) and the specificity was 94.6% (95% CI, 86.7-98.5%). CONCLUSION: This pilot study confirms the feasibility of PM-US for virtual autopsy as early as 11 weeks' gestation. This new technique shows high sensitivity and specificity in detecting congenital structural abnormalities as compared with conventional autopsy. Copyright © 2014 ISUOG. Published by John Wiley & Sons Ltd.


Subject(s)
Autopsy/instrumentation , Congenital Abnormalities/diagnosis , Ultrasonography, Prenatal/methods , Autopsy/methods , Feasibility Studies , Female , Gestational Age , Humans , Pilot Projects , Pregnancy , Prospective Studies , Sensitivity and Specificity
6.
Minerva Ginecol ; 63(3): 213-8, 2011 Jun.
Article in Italian | MEDLINE | ID: mdl-21654606

ABSTRACT

AIM: The aim of this paper was to investigate the sex ratio in the offspring of pregnant patients with polycystic ovary syndrome (PCOS). METHODS: Analysis of 70 pregnant patients with PCOS who achieve a pregnancy without any kind of treatment, and having as controls 63 healthy pregnant women without any feature of PCOS. RESULTS: No significant difference in sex ratio was detected between PCOS and controls, even if it resulted significantly different in the full-blown and non-PCO phenotypes. CONCLUSION: The PCOS phenotypes influenced the sex ratio in the offspring, suggesting that environmental factors could play a role in determination of the offspring gender.


Subject(s)
Polycystic Ovary Syndrome/genetics , Pregnancy Complications, Neoplastic/genetics , Sex Ratio , Female , Humans , Infant, Newborn , Male , Phenotype , Pregnancy
7.
Minerva Ginecol ; 63(2): 171-80, 2011 Apr.
Article in Italian | MEDLINE | ID: mdl-21508905

ABSTRACT

AIM: The aim of this paper was to compare two anti-incontinence procedures during laparoscopic sacrocolpopexy (LSC) to prevent postoperative stress urinary incontinence (SUI). METHODS: Retrospective analysis of 90 continent hysterectomized patients with vaginal vault prolapse treated with LSC plus colposuspension (group A, N.=30), LSC plus retropubic mid-urethral sling (group B, N.=30), or LSC alone (group C, N.=30). RESULTS: De novo SUI rate resulted significantly (P<0.05) lower in group B than C. No difference was detected regarding de novo urge urinary incontinence. Total reoperation rate resulted significantly (P<0.05) higher in group A than B and lower in group B than C. CONCLUSION: When associated to LSC for preventing SUI, colposuspension and retropubic mid-urethral sling are effective and safe, even if mid-urethral sling seems to provide the best risk/benefit profile.


Subject(s)
Laparoscopy , Pelvic Organ Prolapse/surgery , Suburethral Slings , Urinary Incontinence, Stress/prevention & control , Female , Gynecologic Surgical Procedures/adverse effects , Gynecologic Surgical Procedures/methods , Humans , Middle Aged , Retrospective Studies , Urinary Incontinence, Stress/etiology
8.
Am Heart J ; 148(1): e5, 2004 Jul.
Article in English | MEDLINE | ID: mdl-15215814

ABSTRACT

BACKGROUND: Essential hypertension is associated with enhanced LDL oxidation and impaired endothelium-dependent vasodilation. The antioxidant status is linked to the nitric oxide (NO) pathway. Sulfhydryl angiotensin-converting enzyme (ACE) inhibitors inhibit oxidative stress and atherogenesis in experimental models; therefore we tested whether this beneficial antioxidant activity could be also clinically relevant in patients with essential hypertension. METHODS: Plasma LDL oxidizability was investigated initially in untreated normocholesterolemic patients with moderate essential hypertension without clinically evident target organ damage (n = 96) and in control normotensive subjects (n = 46). Patients were then randomly assigned into two age- and sex-matched groups to receive the new sulfhydryl ACE inhibitor zofenopril (15 to 30 mg/d; n = 48) or enalapril (20 mg/d, n = 48). LDL oxidizability was evaluated (generation of malondialdehyde, MDA) and systemic oxidative stress was evaluated by isoprostanes (8-isoPGF2alpha). Asymmetrical dimethyl-L-arginine (ADMA), a competitive inhibitor of endothelial NO synthase, and plasma nitrite and nitrates (NOx) were also measured. RESULTS: LDL from hypertensive subjects had enhanced susceptibility to oxidation in vitro compared with that in control subjects (P <.05). Similarly, isoprostanes were significantly increased (P <.01) in hypertensive subjects versus control subjects. After 12-week treatment, MDA levels were significantly reduced by zofenopril (P <.05) but not enalapril treatment (P = not significant). Isoprostanes were normalized after zofenopril treatment (P <.03), whereas enalapril was ineffective. After treatment with both ACE inhibitors, plasma NOx concentrations were significantly reduced (P <.05). Similarly, hypertension increased ADMA concentration compared with the normotensive state, whereas ACE inihibition elicited a significant decrease. However, the reduction of ADMA concentration was significantly higher in patients receiving sulfhydryl ACE inhibition (P <.05 vs enalapril). CONCLUSIONS: The sulfhydryl ACE inhibitor zofenopril reduces oxidative stress and improves the NO pathway in patients with essential hypertension. If confirmed in a large multicenter clinical trial, our data suggest a possible vasculoprotective effect of the compound in retarding vascular dysfunction and atherogenesis that often develops rapidly in hypertensive patients.


Subject(s)
Angiotensin-Converting Enzyme Inhibitors/pharmacology , Arginine/analogs & derivatives , Captopril/analogs & derivatives , Captopril/pharmacology , Enalapril/pharmacology , Hypertension/drug therapy , Nitric Oxide/metabolism , Oxidative Stress/drug effects , Angiotensin-Converting Enzyme Inhibitors/therapeutic use , Arginine/metabolism , Captopril/therapeutic use , Enalapril/therapeutic use , Female , Humans , Hypertension/metabolism , Lipid Peroxidation/drug effects , Lipoproteins, LDL/metabolism , Male , Middle Aged , Nitrates/blood , Nitrites/blood
9.
Int J Cardiol ; 81(2-3): 107-15; discusssion 115-6, 2001 Dec.
Article in English | MEDLINE | ID: mdl-11744122

ABSTRACT

The effects of chronic treatment with the new sulfhydryl angiotensin-converting enzyme (ACE)-inhibitor, zofenopril, in comparison with the classical sulfhydryl ACE-inhibitor captopril or enalapril or placebo on the development of atherosclerosis were determined in apolipoprotein-E knockout (apoE(-/-)) mice. Groups of 2-month-old male mice received either placebo (N=10), 0.05 mg/kg/day of zofenopril (N=10), 1 mg/kg/day of zofenopril (N=10), 5 mg/kg/day of captopril (N=10) or 0.5 mg/kg/day of enalapril (N=8). After 29 weeks of treatment, computer-assisted imaging analysis revealed that zofenopril reduced the aortic cumulative lesion area by 78% at 0.05 mg/kg/day and by 89% at 1 mg/ml/day of zofenopril compared to that of the placebo (P<0.0001). Captopril reduced by 52% aortic lesions compared to placebo (P<0.01 vs. placebo; P<0.05 vs. zofenopril at both doses). Enalapril did not reduce aortic lesions. Furthermore, 0.05 mg/kg/day of zofenopril reduced susceptibility of plasma LDL to in vitro oxidation compared to captopril, enalapril or placebo, as shown by significant reduction of malondialdehyde content (P<0.001 vs. placebo or enalapril; P<0.05 vs. captopril), as well as by the prolongation of lag-time (P<0.01 vs. placebo or enalapril P<0.05 vs. captopril). More importantly, mice treated with 1 mg/ml/day of zofenopril had a significant decrease in the intimal immunohistochemical presence of oxidation-specific epitopes on oxLDL (NA59 monoclonal antibody, P<0.01), macrophages derived foam cells (F4/80 monoclonal antibody, P<0.05) and native LDL (NP monoclonal antibody, P<0.01) compared to placebo, captopril or enalapril. Thus, chronic treatment with the new sulfhydryl ACE-inhibitor zofenopril has antiatherosclerotic and antioxidant effects in the arterial wall of hypercholesterolemic apoE(-/-) mice. This protection was significantly higher than that reached with captopril and at lower doses of the drug. Treatment with 0.5 mg/kg/day of enalapril did not provide any protective effect.


Subject(s)
Angiotensin-Converting Enzyme Inhibitors/therapeutic use , Apolipoproteins E/drug effects , Arteries/drug effects , Arteriosclerosis/drug therapy , Arteriosclerosis/immunology , Captopril/analogs & derivatives , Lipid Peroxidation/drug effects , Lipoproteins, LDL/immunology , Lipoproteins, LDL/metabolism , Oxidative Stress/drug effects , Sulfhydryl Reagents/therapeutic use , Animals , Aortic Valve Stenosis/drug therapy , Aortic Valve Stenosis/etiology , Aortic Valve Stenosis/metabolism , Arteries/chemistry , Arteriosclerosis/metabolism , Blood Pressure/drug effects , Captopril/administration & dosage , Captopril/antagonists & inhibitors , Captopril/therapeutic use , Cholesterol/blood , Disease Models, Animal , Dose-Response Relationship, Drug , Enalapril/therapeutic use , Epitopes/metabolism , Immunohistochemistry , Lipoproteins, LDL/blood , Male , Mice , Mice, Knockout , Oxidation-Reduction , Peptidyl-Dipeptidase A/blood , Peptidyl-Dipeptidase A/drug effects , Random Allocation , Time Factors , Treatment Outcome
10.
Stroke ; 32(11): 2472-9, 2001 Nov.
Article in English | MEDLINE | ID: mdl-11692003

ABSTRACT

BACKGROUND AND PURPOSE: Atherosclerosis occurs later and is less extensive in intracranial arteries than in extracranial arteries. However, the mechanisms responsible are poorly understood. A previous study has suggested a better antioxidant protection of intracranial arteries. METHODS: To assess the influence of age on arterial activity of antioxidant enzymes and atherogenesis, we compared intracranial and extracranial arteries of humans of different ages who retrospectively lacked confounding classic risk factors (48 premature fetuses aged 6.4+/-0.8 months [mean+/-SD], 58 children aged 7.9+/-3.8 years, 42 adults aged 42.5+/-5.1 years, and 40 elderly subjects aged 71.8+/-3.4 years; all males). Lesions were quantified by computer-assisted imaging analysis of sections of the middle cerebral and basilar arteries, the left anterior descending coronary artery, the common carotid artery, and the abdominal aorta. Macrophages, apolipoprotein B, oxidized LDL, and matrix metalloproteinase-9 in lesions were determined by immunocytochemistry. The effect of aging on atherogenesis was then compared with that on the activity of 4 antioxidant enzymes in the arterial wall. RESULTS: Atherosclerosis was 6- to 19-fold greater (P<0.01) in extracranial arteries than in intracranial arteries, and it increased linearly with age. Intracranial arteries showed significantly greater antioxidant enzyme activities than did extracranial arteries. However, the antioxidant protection of intracranial arteries decreased significantly in older age, coinciding with a marked acceleration of atherogenesis. An increase in matrix metalloproteinase-9 protein expression and in gelatinolytic activity consistent with the degree of intracranial atherosclerosis was also observed. CONCLUSIONS: These results suggest that a greater activity of antioxidant enzymes in intracranial arteries may contribute to their greater resistance to atherogenesis and that with increasing age intracranial arteries respond with accelerated atherogenesis when their antioxidant protection decreases relatively more than that of extracranial arteries.


Subject(s)
Cerebral Arteries/enzymology , Intracranial Arteriosclerosis/enzymology , Intracranial Arteriosclerosis/etiology , Adult , Age Factors , Aged , Antioxidants/analysis , Apolipoproteins B/analysis , Apolipoproteins B/immunology , Arteries/chemistry , Arteries/enzymology , Arteries/pathology , Cerebral Arteries/chemistry , Cerebral Arteries/pathology , Child , Disease Progression , Humans , Immunohistochemistry , Intracranial Arteriosclerosis/pathology , Lipid Peroxidation , Lipoproteins, LDL/analysis , Lipoproteins, LDL/immunology , Male , Matrix Metalloproteinase 9/metabolism , Retrospective Studies , Risk Factors , Superoxide Dismutase/analysis , Superoxide Dismutase/immunology
11.
Eur Heart J ; 22(22): 2075-84, 2001 Nov.
Article in English | MEDLINE | ID: mdl-11686665

ABSTRACT

BACKGROUND: Although individuals with diabetes mellitus frequently have dyslipidaemias and high blood pressure, much of the increased risk for coronary heart disease is not explained by these and other classical risk factors. Thus, other less widely recognized risk factors, including increased susceptibility of low-density lipoprotein (LDL) to oxidation, might enhance vascular dysfunction and atherogenesis in diabetes. AIMS: We compared both the rate and extent of LDL oxidation ex vivo between 78 poorly controlled individuals with type 1 diabetes and 78 age- and sex-matched non-diabetic controls. We then initiated intensive insulin therapy for 3 months to determine the impact of improved glucose control on LDL composition and oxidation. RESULTS: Diabetic and non-diabetic individuals did not have significantly different body weights, dietary intake, blood pressure, renal function or plasma lipid levels. LDL composition was also similar in both groups. In contrast, vitamin E content in LDL was significantly lower in diabetic patients. Measures of LDL lipid oxidation, including conjugated diene, lipid peroxide and thiobarbituric acid reactive substances formation, as well as measures of LDL protein modification, were significantly greater in diabetic patients. Levels of hyperglycaemia correlated strongly with each measure of LDL lipid oxidation (r ranges from 0.60-0.81, P<0.05 for each correlation). After improved glucose control (average reduction in % Hb(Alc)of 5.5 units) all measures of LDL oxidation improved dramatically and approached values for non-diabetics. Absolute values of LDL oxidation increased among all categories of age in both diabetic and control individuals, and this relationship persisted even after adjustment for differences in glucose concentrations. CONCLUSIONS: We demonstrate that hyperglycaemia has a potent but reversible effect on LDL oxidation and that age may independently enhance LDL susceptibility to oxidation. These pathophysiological effects may play an important role in determining vascular complications and atherogenesis in poorly controlled type 1 diabetic patients.


Subject(s)
Aging/physiology , Blood Glucose/physiology , Diabetes Mellitus, Type 1/metabolism , Disease Susceptibility/metabolism , Lipoproteins, LDL/metabolism , Adult , Age Factors , Apolipoprotein B-100 , Apolipoproteins B/metabolism , Female , Follow-Up Studies , Humans , Lipid Peroxidation/physiology , Lipids/blood , Male , Middle Aged , Oxidation-Reduction , Reactive Oxygen Species/blood
12.
Circ Res ; 89(11): 991-6, 2001 Nov 23.
Article in English | MEDLINE | ID: mdl-11717155

ABSTRACT

Maternal hypercholesterolemia during pregnancy is associated with enhanced fatty streak formation in human fetuses and faster progression of atherosclerosis during childhood even under normocholesterolemic conditions. A causal role of maternal hypercholesterolemia in lesion formation during fetal development has previously been established in rabbits. The same experimental model is now used to establish that maternal hypercholesterolemia or ensuing pathogenic events in fetal arteries enhance atherogenesis later in life. Five groups of rabbit mothers were fed chow, cholesterol-enriched chow, or cholesterol-enriched chow plus 1000 IU vitamin E, 3% cholestyramine, or both during pregnancy. Offspring of all groups (n=136) were fed a mildly hypercholesterolemic diet for up to a year and had similar cholesterol levels. Aortic lesion sizes and lipid peroxidation products in plasma and lesions in offspring were determined at birth, 6 months, or 12 months. Lesion progression in offspring of hypercholesterolemic mothers was greater than in all other groups. At each time point, offspring of hypercholesterolemic mothers had 1.5- to 3-fold larger lesions than offspring of normocholesterolemic mothers (P<0.01), with the greatest absolute differences at 12 months. Maternal treatment reduced lesions by 19% to 53%, compared with offspring of untreated hypercholesterolemic mothers (P<0.01), with the greatest effect in the vitamin E groups. At 12 months, lesions in offspring of all vitamin E and cholestyramine-treated mothers were similar to those of normocholesterolemic mothers. Lipid peroxidation end-products in lesions and plasma showed analogous differences between groups as lesions (P<0.01). Thus, pathogenic programming in utero increases the susceptibility to atherogenic risk factors later in life and maternal intervention with cholesterol-lowering drugs or antioxidants reduce postnatal lipid peroxidation and atherosclerosis in their offspring.


Subject(s)
Arteriosclerosis/etiology , Hypercholesterolemia/drug therapy , Animals , Anticholesteremic Agents/therapeutic use , Antioxidants/therapeutic use , Aorta/pathology , Aortic Diseases/blood , Aortic Diseases/etiology , Aortic Diseases/pathology , Arteriosclerosis/blood , Arteriosclerosis/pathology , Cholestyramine Resin/therapeutic use , Disease Progression , Female , Linoleic Acid/blood , Lipid Peroxidation , Malondialdehyde/blood , Pregnancy , Rabbits , Vitamin E/therapeutic use
13.
J Hypertens ; 19(9): 1691-6, 2001 Sep.
Article in English | MEDLINE | ID: mdl-11564991

ABSTRACT

OBJECTIVE: To compare the antihypertensive efficacy and tolerability of a once-daily fixed valsartan/hydrochlorothiazide (HCTZ) combination and amlodipine in subjects with mild-to-moderate hypertension. SUBJECTS AND SETTING: In this multicentre, double-blind, randomized, comparative trial, 690 patients with sitting systolic blood pressure (BP) > or = 160 mmHg and sitting diastolic BP > or = 95 mmHg at the end of a 2-week placebo wash-out period were randomized to valsartan-based treatment (n = 342) or amlodipine (n = 348). METHODS: The patients received valsartan 80 mg o.d. or amlodipine 5 mg o.d for 4 weeks; in the case of an unsatisfactory blood pressure response, the treatments could be respectively changed to the fixed combination of valsartan 80 mg + HCTZ 12.5 mg o.d. or amlodipine 10 mg o.d. for a further 8 weeks. RESULTS: Both treatment approaches decreased systolic blood pressure and diastolic blood pressure to the same extent. The rate of responders to treatment at the end of fourth week (before up-titration) was 57.4% among the valsartan-treated patients and 61.9% among the amlodipine-treated patients (ns). At the end of the study, the rate of responders was not significantly different between the two groups (74.9 versus 72.1%). Valsartan-based treatment had a slightly lower incidence of adverse events (1.5 versus 5.5%; P = 0.006). CONCLUSIONS: The results of this trial demonstrate that the valsartan/hydrochlorothiazide combination and amlodipine are equally effective in lowering BP, and that the combination is better tolerated.


Subject(s)
Amlodipine/therapeutic use , Antihypertensive Agents/administration & dosage , Antihypertensive Agents/therapeutic use , Hydrochlorothiazide/administration & dosage , Hypertension/drug therapy , Hypertension/physiopathology , Tetrazoles/administration & dosage , Valine/analogs & derivatives , Valine/administration & dosage , Adult , Aged , Amlodipine/adverse effects , Antihypertensive Agents/adverse effects , Blood Pressure/drug effects , Double-Blind Method , Drug Combinations , Female , Humans , Hydrochlorothiazide/adverse effects , Hydrochlorothiazide/therapeutic use , Male , Middle Aged , Severity of Illness Index , Tetrazoles/adverse effects , Tetrazoles/therapeutic use , Treatment Outcome , Valine/adverse effects , Valine/therapeutic use , Valsartan
14.
Proc Natl Acad Sci U S A ; 98(5): 2860-4, 2001 Feb 27.
Article in English | MEDLINE | ID: mdl-11226331

ABSTRACT

Restenosis is due to neointimal hyperplasia, which occurs in the coronary artery after percutaneous transluminal coronary angioplasty (PTCA). During restenosis, an impairment of nitric oxide (NO)-dependent pathways may occur. Concomitant hypercholesterolemia may exacerbate restenosis in patients undergoing PTCA. Here, we show that a NO-releasing aspirin derivative (NCX-4016) reduces the degree of restenosis after balloon angioplasty in low-density lipoprotein receptor-deficient mice and this effect is associated with reduced vascular smooth muscle cell (VSMC) proliferation and macrophage deposition at the site of injury. Drugs were administered following both therapeutic or preventive protocols. We demonstrate that NCX-4016 is effective both in prevention and treatment of restenosis in the presence of hypercholesterolemia. These data indicate that impairment of NO-dependent mechanisms may be involved in the development of restenosis in hypercholesterolemic mice. Although experimental models of restenosis may not reflect restenosis in humans in all details, we suggest that a NO-releasing aspirin derivative could be an effective drug in reducing restenosis following PTCA, especially in the presence of hypercholesterolemia and/or gastrointestinal damage.


Subject(s)
Aspirin/pharmacology , Constriction, Pathologic/prevention & control , Hypercholesterolemia/complications , Nitric Oxide/metabolism , Animals , Aspirin/analogs & derivatives , Aspirin/therapeutic use , Constriction, Pathologic/drug therapy , Mice , Mice, Inbred C57BL , Mice, Knockout , Receptors, LDL/genetics , Receptors, LDL/physiology , Recurrence
15.
Antioxid Redox Signal ; 3(6): 1119-30, 2001 Dec.
Article in English | MEDLINE | ID: mdl-11813985

ABSTRACT

Adaptation to various forms of cellular stress involves signal transduction into the cytoplasm and subsequently into the cellular nucleus, and ultimately alteration of gene regulation and expression. Increased oxidative stress, which is associated with increased production of reactive oxygen species and other radical species, plays a pivotal role in vascular dysfunction and contributes substantially to the structural and functional changes leading to vascular disease progression. Activation of oxidation-sensitive transcription factors and molecular mechanisms can be triggered in the systemic, tissue, cellular, and molecular environments, thereby affecting a multitude of pathophysiological events involved in the pathogenesis of atherosclerosis and other vascular diseases. Radicals per se also participate in the pathophysiological vascular response to shear stress and injury. Among the oxidation-sensitive transcription factors, important roles have been ascribed to nuclear factor-kappaB, c-Myc, and the peroxisome proliferator-activated receptor family. Regulation of nuclear events has also been recently proposed to involve corepressor and coactivator molecules. Identification of the genes that are involved in these processes has been facilitated by recent development of microarray chip techniques, which allow simultaneous evaluation of differential gene expression. As many of the transcription factors or their interactions are redox-regulated, antioxidant intervention may affect their bioactivity.


Subject(s)
Arteries/metabolism , Oxygen/metabolism , Transcription Factors/metabolism , Animals , Arteriosclerosis , Cell Nucleus/metabolism , Cytoplasm/metabolism , Endothelium, Vascular/metabolism , Free Radicals , Humans , Models, Biological , NF-kappa B/metabolism , Oligonucleotide Array Sequence Analysis , Oxidative Stress , Signal Transduction
16.
Am J Physiol Heart Circ Physiol ; 278(5): H1507-16, 2000 May.
Article in English | MEDLINE | ID: mdl-10775128

ABSTRACT

Oxygen free radicals induce de novo synthesis of tissue factor (TF), the initiator of the extrinsic pathway of coagulation, within the coronary vasculature during postischemic reperfusion. In the present study we wanted to assess whether TF expression might cause myocardial injury during postischemic reperfusion. Anesthetized rabbits underwent 30 min of coronary occlusion followed by 5.5 h of reperfusion. At reperfusion the animals received 1) saline (n = 8), 2) human recombinant, active site-blocked activated factor VII (FVIIai, 1 mg/kg, n = 8), or 3) human recombinant activated FVII (FVIIa, 1 mg/kg, n = 8). FVIIai binds to TF as native FVII, but with the active site blocked it inhibits TF procoagulant activity. The area at risk of infarction (AR), the infarct size (IS), and the no-reflow area (NR) were determined at the end of the experiment. FVIIai resulted in a significant reduction in IS and NR with respect to control animals (28.1 +/- 11.3 and 11.1 +/- 6.1% of AR vs. 59.8 +/- 12.8 and 24.4 +/- 2.7% of AR, respectively, P < 0.01), whereas FVIIa resulted in a significant increase in IS and NR to 80.1 +/- 13. 1 and 61.9 +/- 13.8% of AR, respectively (P < 0.01). In conclusion, TF-mediated activation of the extrinsic coagulation pathway makes an important contribution to myocardial injury during postischemic reperfusion.


Subject(s)
Factor VIIa/pharmacology , Myocardial Infarction/drug therapy , Myocardial Reperfusion Injury/prevention & control , Amino Acid Chloromethyl Ketones/chemistry , Amino Acid Chloromethyl Ketones/pharmacology , Animals , Binding Sites/drug effects , Blood Coagulation/drug effects , Blood Platelets/metabolism , Coronary Circulation/drug effects , Factor VIIa/antagonists & inhibitors , Factor VIIa/chemistry , Fibrinogen/metabolism , Hemodynamics , Hemostatics/antagonists & inhibitors , Hemostatics/metabolism , Humans , Myocardial Infarction/pathology , Rabbits , Recombinant Proteins/antagonists & inhibitors , Recombinant Proteins/chemistry , Recombinant Proteins/pharmacology , Thromboplastin/antagonists & inhibitors , Thromboplastin/metabolism
17.
Cardiovasc Res ; 43(1): 210-8, 1999 Jul.
Article in English | MEDLINE | ID: mdl-10536706

ABSTRACT

BACKGROUND: Previous studies indicate that platelets and leucocytes might contribute to the development of neointimal hyperplasia following arterial injury. The present study was aimed at further investigating the role of platelets and leucocytes, alone or in combination, in promoting vascular smooth muscle cell (SMC) proliferation in vitro, focusing on the relative contribution of different soluble growth factors released by these cells, and on the ability to induce proto-oncogene expression, such as c-fos. METHODS: SMCs from rabbit aortas, made quiescent by serum deprivation, were stimulated with either activated platelets, leucocytes, or both, separated from SMCs by a membrane insert. SMC proliferation was evaluated by measuring the incorporation of 3H-thymidine. The relative contribution of different platelet-derived mediators to SMC growth was evaluated by adding either ketanserin, a 5-HT2 receptor antagonist, R68070, a TxA2 receptor antagonist, BN52021, a platelet activating factor (PAF) receptor antagonist, and trapidil, a platelet derived growth factor (PDGF) receptor antagonist. The role of different leucocyte sub-populations (neutrophils and monocytes + lymphocytes) was also determined in additional experiments. RESULTS: SMC proliferation was significantly increased by activated platelets to 360 +/- 9% of control values (P < 0.05). This effect was reduced by ketanserin, R68070, BN 52021 or trapidil. Whole leucocytes, neutrophils or lymphocytes + monocytes also increased SMC proliferation with respect to control experiments. Simultaneous stimulation of SMCs by platelets and whole leucocytes was associated with a significant greater increase in SMC proliferation as compared to SMC stimulated with platelets or leucocytes alone. c-fos expression, almost undetectable in unstimulated SMCs, was markedly increased by activated platelets or leucocytes. CONCLUSIONS: Activated platelets promote SMC proliferation in vitro via release of soluble mediators, including serotonin, thromboxane A2 PAF and PDGF; activated leucocytes also induce a significant SMC proliferation and exert an additive effect when activated together with platelets; SMCs stimulated with activated platelets and leucocytes show an early expression of the proto-oncogene c-fos.


Subject(s)
Diterpenes , Growth Substances/physiology , Leukocytes/physiology , Muscle, Smooth, Vascular/cytology , Platelet Activation , Animals , Cell Division/drug effects , Coculture Techniques , Fibrinolytic Agents/pharmacology , Gene Expression/drug effects , Genes, fos , Ginkgolides , Ketanserin/pharmacology , Lactones/pharmacology , Muscle, Smooth, Vascular/metabolism , Pentanoic Acids/pharmacology , Pyridines/pharmacology , Rabbits , Receptors, Platelet-Derived Growth Factor/antagonists & inhibitors , Receptors, Thromboxane/antagonists & inhibitors , Selective Serotonin Reuptake Inhibitors/pharmacology , Trapidil/pharmacology
18.
Am J Cardiol ; 84(3): 309-15, 1999 Aug 01.
Article in English | MEDLINE | ID: mdl-10496441

ABSTRACT

Some studies have demonstrated that left ventricular (LV) diastolic function is the principal determinant of impaired exercise capacity in hypertrophic cardiomyopathy (HC). In this study we sought the capability of echocardiographic indexes of diastolic function in predicting exercise capacity in patients with HC. We studied 52 patients with HC while they were not on drugs;12 of them had LV tract obstruction at rest. Diastolic function was assessed by M-mode and Doppler echocardiography by measuring: (1) left atrial fractional shortening, and the slope of posterior aortic wall displacement during early atrial emptying on M-mode left atrial tracing; and (2) Doppler-derived transmitral and pulmonary venous flow velocity indexes. Exercise capacity was assessed by maximum oxygen consumption by cardiopulmonary test during cycloergometer upright exercise. Maximum oxygen consumption correlated with the left atrial fractional shortening (r = 0.63, p <0.001), the slope of posterior aortic wall displacement during early atrial emptying (r = 0.55, p <0.001), age (r = -0.50; p <0.001), pulmonary venous diastolic anterograde velocity (r = 0.41, p <0.01), and the systolic filling fraction (r = -0.43; p <0.01). By stepwise multiple linear regression analysis, left atrial fractional shortening and the pulmonary venous systolic filling fraction were the only determinants of the maximum oxygen consumption (multiple r = 0.70; p <0.001). Exercise capacity did not correlate with Doppler-derived transmitral indexes. Thus, in patients with HC, exercise capacity was determined by passive LV diastolic function, as assessed by the left atrial M-mode and Doppler-derived pulmonary venous flow velocities.


Subject(s)
Cardiomyopathy, Hypertrophic/physiopathology , Exercise , Ventricular Dysfunction, Left/physiopathology , Ventricular Function, Left , Adolescent , Adult , Aged , Blood Flow Velocity , Cardiomyopathy, Hypertrophic/diagnostic imaging , Diastole , Echocardiography, Doppler , Exercise Test , Female , Heart Atria/diagnostic imaging , Humans , Linear Models , Male , Middle Aged , Oxygen Consumption , Pulmonary Veins/diagnostic imaging , Ventricular Dysfunction, Left/diagnostic imaging
19.
Eur Heart J ; 19(3): 411-9, 1998 Mar.
Article in English | MEDLINE | ID: mdl-9568445

ABSTRACT

BACKGROUND: Ischaemic preconditioning reduces myocardial infarct size in animal models. Clinical data suggest that episodes of angina immediately before acute myocardial infarction may be associated with smaller infarct size in man. However, it is unclear whether ischaemic episodes preceding acute myocardial infarction also affect contractile recovery in patients. OBJECTIVE: In this study we investigated the recovery of regional myocardial function after thrombolysis in two groups of patients at their first Q-wave acute myocardial infarction; in one group (n = 42) myocardial infarction occurred unheralded, whereas patients of the second group (n = 48) had experienced new-onset angina in the 48 h that preceded infarction. Echocardiographic analysis of myocardial regional function in the infarct area was done at 2, 24 and 72 h after thrombolysis, and at 1 week, and 1 and 3 months follow-up. RESULTS: Peak level of MB-creatine kinase was significantly lower in patients with new-onset angina (96 +/- 47 as compared with 221 +/- 108 IU.l-1, P < 0.01), as was the area under the MB-creatine kinase curve (1321 +/- 876 as compared to 3879 +/- 1555 U.l-1/36 h, P < 0.01). Hypokinetic segments were fewer in patients with pre-infarction angina. Similarly, wall motion score improved significantly earlier in patients who had new-onset angina before acute myocardial infarction. Thus, contractile recovery was more rapid in patients with previous angina than in those in whom infarction occurred unheralded. Complications during the in-hospital outcome and other variables considered during the 4-week follow-up were similar between groups. CONCLUSIONS: Patients who experienced new-onset angina before acute myocardial infarction showed better recovery of regional function after thrombolysis. Our study supports the hypothesis that brief periods of ischaemia immediately before myocardial infarction may precondition the human heart, thus improving contractile recovery.


Subject(s)
Angina Pectoris/physiopathology , Ischemic Preconditioning, Myocardial , Myocardial Infarction/physiopathology , Plasminogen Activators/therapeutic use , Thrombolytic Therapy , Tissue Plasminogen Activator/therapeutic use , Electrocardiography , Female , Humans , Male , Middle Aged , Myocardial Infarction/drug therapy , Retrospective Studies , Time Factors
20.
Circ Res ; 82(1): 39-46, 1998.
Article in English | MEDLINE | ID: mdl-9440703

ABSTRACT

The extrinsic coagulation pathway is activated when circulating factor VII (FVII) gains access to tissue factor (TF) exposed as a consequence of vascular injury. Increasing evidence indicates that this TF-dependent activation of the coagulation plays an important role in the pathophysiology of intravascular thrombus formation. In the present study, we tested the effects of recombinant human, active site-blocked activated FVII (FVIIai) in a rabbit model of carotid artery thrombosis. Cyclic flow variations (CFVs), due to recurrent thrombus formation, were obtained in stenotic rabbit carotid arteries with endothelial injury. Carotid blood flow velocity was measured by a Doppler flow probe. After 30 minutes of CFVs, the animals received FVIIai (100 microg x kg(-1) x min(-1) intracarotid infusion for 10 minutes, n=9). If CFVs were abolished, animals were followed for 30 additional minutes, after which recombinant human activated FVII (FVIIa) was infused into the carotid artery (100 microg x kg(-1) x min(-1) for 10 minutes) to determine whether FVIIai could be displaced from TF by FVIIa, thus restoring CFVs. To establish the duration of action of FVIIai, an additional group of animals received FVIIai at the same dose as above, and after CFVs were inhibited, they were followed until CFVs were restored or for up to 6 hours. To determine whether CFVs could be restored by epinephrine after their abolition with FVIIai, increasing doses of epinephrine were administered to a third group of 6 animals. FVIIai abolished CFVs in 8 of 9 rabbits (P<.01). This effect was reversible, as FVIIa administration restored CFVs in all animals. Prothrombin times and activated partial thromboplastin times did not change significantly throughout the study. One single 10-minute infusion exerted complete antithrombotic effects for at least 6 hours, despite the fact that at this time point, plasma FVIIai levels were well below threshold concentrations. Epinephrine restored CFVs in 3 of 6 animals in which CFVs were inhibited by FVIIai. FVIIai exerts potent antithrombotic effects in this model; these effects were prolonged even after FVIIai was almost completely cleared from the circulation, probably as a result of the tight binding of FVIIai to TF. Thus, FVIIai might represent an antithrombotic substance of potential interest.


Subject(s)
Carotid Artery Thrombosis/drug therapy , Disease Models, Animal , Factor VIIa/therapeutic use , Fibrinolytic Agents/therapeutic use , Animals , Binding Sites/drug effects , Blood Coagulation/drug effects , Blood Flow Velocity/drug effects , Epinephrine/pharmacology , Factor VIIa/antagonists & inhibitors , Factor VIIa/pharmacokinetics , Female , Humans , Male , Platelet Aggregation/drug effects , Rabbits , Recombinant Proteins/therapeutic use , Recurrence , Vasoconstrictor Agents/pharmacology
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