Nano-Hybrid Ag@LCCs Systems with Potential Wound-Healing Properties

The synthesis of contaminant-free silver@linear carbon chains (Ag@LCCs) nanohybrid systems, at different Ag/LCCs ratios, by pulsed laser ablation was studied. The ablation products were first characterized by several diagnostic techniques: conventional UV-Vis optical absorption and micro-Raman spectroscopies, as well as scanning electron microscopy, operating in transmission mode. The experimental evidence was confirmed by the theoretical simulations' data. Furthermore, to gain a deeper insight into the factors influencing metal@LCCs biological responses in relation to their physical properties, in this work, we investigated the bioproperties of the Ag@LCCs nanosystems towards a wound-healing activity. We found that Ag@LCC nanohybrids maintain good antibacterial properties and possess a better capability, in comparison with Ag NPs, of interacting with mammalian cells, allowing us to hypothesize that mainly the Ag@LCCs 3:1 might be suitable for topical application in wound healing, independent of (or in addition to) the antibacterial effect.

Correction: Condorelli et al. Nano-Hybrid Au@LCCs Systems Displaying Anti-Inflammatory Activity. Materials 2022, 15, 3701

The authors wish to make the following correction to the published paper [...].

Nano-Hybrid Au@LCCs Systems Displaying Anti-Inflammatory Activity

Gold nanoparticles (Au NPs) have received great attention owing to their biocompatible nature, environmental, and widespread biomedical applications. Au NPs are known as capable to regulate inflammatory responses in several tissues and organs; interestingly, lower toxicity in conjunction with anti-inflammatory effects was reported to occur with Au NPs treatment. Several variables drive this benefit-risk balance, including Au NPs physicochemical properties such as their morphology, surface chemistry, and charge. In our research we prepared hybrid Au@LCC nanocolloids by the Pulsed Laser Ablation, which emerged as a suitable chemically clean technique to produce ligand-free or functionalized nanomaterials, with tight control on their properties (product purity, crystal structure selectivity, particle size distribution). Here, for the first time to our knowledge, we have investigated the bioproperties of Au@LCCs. When tested in vitro on intestinal epithelial cells exposed to TNF-α, Au@LCCs sample at the ratio of 2.6:1 showed a significantly reduced TNF gene expression and induced antioxidant heme oxygenase-1 gene expression better than the 1:1 dispersion. Although deeper investigations are needed, these findings indicate that the functionalization with LCCs allows a better interaction of Au NPs with targets involved in the cell redox status and inflammatory signaling.

Safety of fertility preservation techniques before and after anticancer treatments in young women with breast cancer: a systematic review and meta-analysis

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.

The corona of protein-gold nanoparticle systems: the role of ionic strength

The nature of the nanoparticle-protein corona is emerging as a key aspect in determining the impact of nanomaterials on proteins and in general on the biological response. We previously demonstrated that citrate-stabilized gold nanoparticles (Cit-AuNPs) interact with β2-microglobulin (β2m) preserving the protein native structure. Moreover, Cit-AuNPs are able to hinder in vitro fibrillogenesis of a β2m pathologic variant, namely D76N, by reducing the oligomeric association of the protein in solution. Here, we clarify the characteristics of the interaction between β2m and Cit-AuNPs by means of different techniques, i.e. surface enhanced Raman spectroscopy, NMR and quartz crystal microbalance with dissipation monitoring. All the results obtained clearly show that by simply changing the ionic strength of the medium it is possible to switch from a labile and transient nature of the protein-NP adduct featuring the so-called soft corona, to a more "hard" interaction with a layer of proteins having a longer residence time on the NP surface. This confirms that the interaction between β2m and Cit-AuNPs is dominated by electrostatic forces which can be tuned by modifying the ionic strength.

Safety of assisted reproductive techniques in young women harboring germline pathogenic variants in BRCA1/2 with a pregnancy after prior history of breast cancer

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.

One-Pot Synthesis of TiO2-rGO Photocatalysts for the Degradation of Groundwater Pollutants

A non-conventional approach to prepare titanium dioxide-reduced graphene oxide (TiO₂-rGO) nanocomposites based on solar photoreduction is here presented. The standard hydro-solvothermal synthesis of the TiO₂-rGO composites requires high temperatures and several steps, whereas the proposed one-pot preparation allows one to obtain the photocatalysts with a simple and green procedure, by exploiting the photocatalytic properties of titania activated by the solar irradiation. The TiO₂-rGO catalysts were tested in the solar photodegradation of a widely adopted toxic herbicide (2,4-Dichlorophenoxyacetic acid, 2,4-D), obtaining the 97% of degradation after 3 h of irradiation. The as-prepared TiO₂-rGO composites were more active compared to the same photocatalysts prepared through the conventional thermal route. The structural, optical, and textural properties of the composites, determined by Raman, Photoluminescence, Fourier Transform InfraRed (FTIR), UV-vis diffuse reflectance (DRS) spectroscopies, and N₂ absorption-desorption measurements, showed as the solar irradiation favors the reduction of graphene oxide with higher efficiency compared to the thermal-driven synthesis. Furthermore, the possible toxicity of the as-synthesized composites was measured exposing nauplii of microcrustacean Artemia sp. to solutions containing TiO₂-rGO. The good results in the 2,4-D degradation process and the easiness of the TiO₂-rGO synthesis allow to consider the proposed approach a promising strategy to obtain performing photocatalysts.

Impact of ARTs on oncological outcomes in young breast cancer survivors

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.

Benchmarks of SMA-Copolymer Derivatives and Nanodisc Integrity

Poly(styrene-co-maleic acid) or SMA and its derivatives, a family of synthetic amphipathic copolymers, are increasingly used to directly solubilize cell membranes to functionally reconstitute membrane proteins in native-like copolymer-lipid nanodiscs. Although these copolymers act, de facto, like a "macromolecular detergent", the polymer-based lipid-nanodiscs has been demonstrated to be an excellent membrane mimetic for structural and functional studies of membrane proteins and their complexes by a variety of biophysical and biochemical approaches. In many studies reported in the literature, the choice of the right SMA formulation can depend on a number of factors, and the experimental conditions are typically developed according to a trial-and-error process since each studied system requires adapted protocols. While increasing number of nanodisc-forming copolymers are reported to be useful and they provide flexibilities in optimizing the sample preparation conditions, it is important to develop a systematic protocol that can be used for various applications. In this context, there is a vital necessity of benchmarking the performances of existing copolymer formulations, assessing crucial parameters for the successful extraction, isolation, and stabilization of membrane proteins. In this study, we compare both copolymers and copolymer-lipid nanodiscs obtained by SMA-EA with a set of anionic XIRAN copolymer formulations commercially available under the names of SL25010 P, SL30010 P, and SL40005 P. The reported results show how the critical micellar concentration (c.m.c.) of each copolymer is significantly altered in the presence of lipids and confirms the existence of an equilibrium between nanodisc-bound and "free" or "micellar" copolymer chains in the solution. We believe that these findings can be exploited to optimize studies that involve the necessity of special copolymers, which would not only simplify the applications but also broaden the scope of polymer-based nanodiscs.

Nanoparticles Engineering by Pulsed Laser Ablation in Liquids: Concepts and Applications

Laser synthesis emerges as a suitable technique to produce ligand-free nanoparticles, alloys and functionalized nanomaterials for catalysis, imaging, biomedicine, energy and environmental applications. In the last decade, laser ablation and nanoparticle generation in liquids has proven to be a unique and efficient technique to generate, excite, fragment and conjugate a large variety of nanostructures in a scalable and clean way. In this work, we give an overview on the fundamentals of pulsed laser synthesis of nanocolloids and new information about its scalability towards selected applications. Biomedicine, catalysis and sensing are the application areas mainly discussed in this review, highlighting advantages of laser-synthesized nanoparticles for these types of applications and, once partially resolved, the limitations to the technique for large-scale applications.

Minimally invasive fetal autopsy using ultrasound: a feasibility study

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.

Detection and characterization at nM concentration of oligomers formed by hIAPP, Aβ(1–40) and their equimolar mixture using SERS and MD simulations

We report a structural investigation on IAPP, Aβ(1–40) and their equimolar mixture at nM concentration using SERS spectroscopy and molecular dynamic simulations.

[Sex ratio in the offspring of pregnant women with polycystic ovary syndrome: effect of different phenotypes]

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.

[A retrospective analysis comparing colposuspension and retropubic mid-urethral sling as preventive anti-incontinence measures during laparoscopic sacrocolpopexy]

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.

Increased cardiac output and lowered peripheral resistance during metoprolol treatment

Echocardiography was performed at every six months in hypertensives well controlled on metoprolol, 100 mg twice a day. After six months' treatment blood pressure was reduced from 177/110 mm Hg to 147/88 (p less than 0.02). LV wall thickness (septum + posterior wall) was unchanged 2.10 cm (2.14), and a significant drop in cardiac output (CO) to 5.0 l/min (6.1, p less than 0.02) was recorded (pretreatment values in brackets). After 24 months' treatment LV wall thickness was reduced to 1.94 cm (p less than 0.02), total peripheral resistance (TPR) to 17.3 mm Hg/l/min (23.4, p less than 0.02) and CO increased to 6.7 l/min (6.1, n.s.). After six months' treatment, there was thus a drop in BP with a significant drop in CO and unchanged TPR. After 24 months' treatment, however, CO was back to the pretreatment level and the drop in BP was entirely caused by a drop in TPR which was probably secondary to a reduction in the wall thickness of the arterial resistance vessels as judged by the relationship between the reduction in wall thickness in the LV and the reduction in TPR during the treatment.

May age onset be relevant in the occurrence of left ventricular hypertrophy in Friedreich's ataxia?

BACKGROUND

Although heart involvement has been widely reported in Friedreich's ataxia (FA), which is the most prevalent of the spino-cerebellar degenerative diseases, the reason that cardiac abnormalities develop has not been yet established.

HYPOTHESIS

The investigation was undertaken to study the prevalence and characteristics of cardiac abnormalities in patients with FA and to evaluate whether the presence of left ventricular hypertrophy could be predicted.

METHODS

In all, 75 patients with FA and 16 patients with late onset FA (LOFA) disease were investigated for cardiac abnormalities using noninvasive methods.

RESULTS

A significant (p < 0.01) difference in the age onset (9.8 +/- 3.9 years) was found in 31 of the 75 patients with FA (41%) who showed left ventricular hypertrophy (LVH) at echocardiographic examination compared with the remaining 44 patients with FA without LVH (12.6 +/- 4.3 years). Moreover, none of the 16 patients with LOFA (age onset 26.5 +/- 4.2 years) showed abnormalities at echocardiographic examination. A significant (p < 0.01) concordance in the familial distribution of hypertrophy was also found.

CONCLUSION

These data suggest that the earlier the disease develops the more frequently LVH occurs.

Sulfhydryl angiotensin-converting enzyme inhibition induces sustained reduction of systemic oxidative stress and improves the nitric oxide pathway in patients with essential hypertension

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.

Chronic treatment with sulfhydryl angiotensin-converting enzyme inhibitors reduce susceptibility of plasma LDL to in vitro oxidation, formation of oxidation-specific epitopes in the arterial wall, and atherogenesis in apolipoprotein E knockout mice

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.

Oxidation-sensitive transcription factors and molecular mechanisms in the arterial wall

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.

Maternal hypercholesterolemia and treatment during pregnancy influence the long-term progression of atherosclerosis in offspring of rabbits

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.

Effect of glycaemic control and age on low-density lipoprotein susceptibility to oxidation in diabetes mellitus type 1

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.

Age-related effects on atherogenesis and scavenger enzymes of intracranial and extracranial arteries in men without classic risk factors for atherosclerosis

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.

A multicenter, randomized double-blind study of valsartan/hydrochlorothiazide combination versus amlodipine in patients with mild to moderate hypertension

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.

Effects of nitric oxide-releasing aspirin versus aspirin on restenosis in hypercholesterolemic mice

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.

Recombinant human, active site-blocked factor VIIa reduces infarct size and no-reflow phenomenon in rabbits

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.

Exercise capacity in hypertrophic cardiomyopathy depends on left ventricular diastolic function

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.

Activated platelets and leucocytes cooperatively stimulate smooth muscle cell proliferation and proto-oncogene expression via release of soluble growth factors

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.

New-onset angina preceding acute myocardial infarction is associated with improved contractile recovery after thrombolysis

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.

Antithrombotic effects of recombinant human, active site-blocked factor VIIa in a rabbit model of recurrent arterial thrombosis

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.

Intrarenal determinants of sodium retention in mild heart failure: effects of angiotensin-converting enzyme inhibition

The onset and the mechanisms leading to Na+ retention in incipient congestive heart failure (CHF) have not been systematically investigated. To investigate renal Na+ handling in the early or mild stages of CHF, Na+ balance and renal clearances were assessed in 10 asymptomatic patients with idiopathic or ischemic dilated cardiomyopathy and mild heart failure (HF) off treatment (left ventricular ejection fraction, 29.7+/-2%) and in 10 matched normal subjects during a diet containing 100 mmol/d of NaCl and after 8 days of high salt intake (250 mmol/d). Six patients were studied again after 6 weeks of treatment with enalapril (5 mg/d P.O.). At the end of the high salt diet, in patients with mild HF the cumulative Na+ balance exceeded by 110 mmol that of normal subjects (F=3.86, P<.001). During high salt intake, renal plasma flow and glomerular filtration rate were similarly increased in both normal subjects and mild HF patients. In spite of comparable increases of filtered Na+ in the two groups, fractional excretion of Na+, fractional clearance of free water, and fractional excretion of K+ (indexes of distal delivery of Na+) increased in normal subjects and were reduced in patients with mild HF. During enalapril treatment, in the mild HF patients the cumulative Na+ balance was restored to normal; furthermore, enalapril significantly attenuated the abnormalities in the distal delivery of Na+. Our results indicate that a defective adaptation of Na+ reabsorption in the proximal nephron is associated with Na+ retention in response to increased salt intake in the early or mild stages of HF. These abnormalities of renal Na+ handling are largely reversed by enalapril.

Inhibition of leucocyte and platelet adhesion reduces neointimal hyperplasia after arterial injury

Restenosis following coronary angioplasty is though to result from migration and proliferation of medial smooth muscle cells. However, the factors that initiate this proliferation are still unknown. In a rabbit model of carotid artery injury, we tested the hypothesis that activated platelets and leucocytes might contribute to the development of neointimal hyperplasia. Following arterial injury, rabbits received either no treatment, R15.7, a monoclonal antibody against the leucocyte CD11/CD18 adhesion complex, aurintricarboxylic acid (ATA), a substance that inhibits platelet glycoprotein Ib-von Willebrand factor interaction, or the combination of R15.7 and ATA. After 21 days, the extent of neointimal hyperplasia was evaluated by planimetry on histological arterial sections. The area of neointima averaged 0.51 +/- 0.07 mm2 in control animals and it was significantly reduced by administration of either R15.7 or ATA alone to 0.12 +/- 0.05 and 0.20 +/- 0.01 mm2, respectively (p < 0.05 vs controls for both groups). The animals that received the combination of R15.7 and ATA showed a further reduction in neointimal hyperplasia, as compared to animals that received ATA alone (p < 0.05 vs ATA alone). These data indicate that platelets and leucocytes play an important role in the pathophysiology of neointimal hyperplasia in this experimental model. Interventions that reduce platelet and leucocyte adhesion to vessel wall might have beneficial effects in reducing restenosis following coronary angioplasty.

Glycosylation enhances oxygen radical-induced modifications and decreases acetylhydrolase activity of human low density lipoprotein

BACKGROUND

Posttranslational nonenzymatic glycosylation of native low-density lipoprotein (n-LDL) occurs both in vitro and in vivo in diabetic patients. Glycosylated LDL (glc-LDL) behave similarly to oxidized LDL in some respects. In fact, unlike n-LDL, uptake the glc-LDL can occur in part by the "scavenger" receptor(s), as also demonstrated for oxidized LDL. The enzyme acetylhydrolase, carried by LDL, catabolizes platelet activating factor (PAF). This enzymatic activity is inhibited in oxidized LDL. However, it is unknown whether glc-LDL have reduced acetylhydrolase activity.

OBJECTIVE

The first aim of the study was to investigate whether glc-LDL were more susceptible than n-LDL to oxidative modification, and which different oxygen radical species were involved in the phenomenon. Moreover, in order to investigate whether glycosylation may affect acetylhydrolase, we also measured this enzymatic activity in both n- and glc-LDL.

METHODS

In vitro glc-LDL and n-LDL were exposed to the oxidants xanthine/xanthine oxidase (X/XO; 2 mM and 100 mU/ml, respectively), or CuSO4 (10 microM) for 18 hs at 37 degrees C. Parallel experiments were done in the presence of the superoxide radical scavenger superoxide dismutase (SOD; 330 U/ml), the hydrogen peroxide scavenger catalase (1000 U/ml), or the hydroxyl radical scavenger dimethylthiourea (10 mM) or dimethylsulfoxide (1 mM). Standards of PAF and lyso-PAF were visualized with iodine vapors after separation by thin layer chromatography. The distribution of label was determined by an imaging scanner. Labeled products were then isolated from the chromatography plate, and the amount of 3H-lyso-PAF formed was determined by liquid scintillation counting.

RESULTS

Glc-LDL were more susceptible than n-LDL to lipid peroxidation (n-LDL 22.9 +/- 3.4 vs 34.8 +/- 4.2* nmoles/MDA/mg of protein in glc-LDL oxidized by X/XO and n-LDL 28.9 +/- 4.2 vs 40.4 +/- 4.1* in glc-LDL oxidized by CuSO4, *p < 0.05 vs n-LDL). SOD, but not other scavengers, prevented peroxidation, indicating an obligatory role for superoxide radicals. Oxidation of glc-LDL also induced a higher degree of apolipoprotein-B100 modifications than n-LDL, with increased electrophoresis mobility and decreased TNBS reactivity. These effects were similarly prevented by SOD. Finally, acetylhydrolase activity was significantly lower in glc-LDL than in n-LDL.

CONCLUSION

Glycosylation increases LDL oxidation due to superoxide radicals, and also reduces acetylhydrolase activity. These phenomenona may contribute to enhance and/or accelerate the progression of atherosclerosis in diabetic patients.

Effects of nisoldipine and/or enalapril on left ventricular function and exercise capacity in patients with recent anterior myocardial infarction and mild cardiac dysfunction

Treatment of abnormal remodeling and dysfunction of left ventricle after myocardial infarction is one of the major goals of recent therapeutic interventions. The current study, the Nisoldipine Enalapril Anterior Myocardial infarction Study pilot investigation, was designed to investigate the effects of 12 weeks of treatment with enalapril or nisoldipine or their combination on left ventricular (LV) function and exercise capacity in patients with recent (< 1 month) anterior myocardial infarction and mild LV dysfunction (LV ejection fraction [EF] 38% to 48%). Forty-six patients were studied and received, by random assignment, enalapril (5 mg once per day) plus placebo (n = 14) or nisoldipine (10 mg two times per day) plus placebo (n = 18) or enalapril (5 mg once per day) plus nisoldipine (10 mg two times per day) (n = 14). All patients received aspirin (325 mg) throughout the study. Data on LV EF and peak filling rate at rest and LV EF during exercise were collected during radionuclide ventriculography. In addition, the product of heart rate and systolic blood pressure (rate-pressure product) and exercise time were determined during exercise stress testing. The analyzed parameters were not significantly modified after treatment with enalapril or with nisoldipine. In contrast, the combination of enalapril and nisoldipine significantly raised LV EF at rest (from 43% +/- 3% to 48% +/- 6%, p < 0.01) and during exercise (from 45% +/- 8% to 50% +/- 9%, p < 0.01) and raised peak filling rate at rest (fraction of end-diastolic volume per second) from 1.57 +/- 0.3 to 1.67 +/- 0.3 (p < 0.05). In addition, the combined administration of the two drugs increased the rate-pressure product (values x 10(3)) (from 20.7 +/- 5 to 22.7 +/- 4, p < 0.05) and increased exercise time (from 573 +/- 173 seconds to 668 +/- 178 seconds, p < 0.05). These results show that in patients with recent anterior myocardial infarction and mild LV dysfunction, the combination of the angiotensin-converting enzyme inhibitor enalapril and the dihydropyridine nisoldipine improves resting LV systolic and diastolic function and exercise LV systolic function and exercise capacity.

Lisinopril in the treatment of congestive heart failure in elderly patients: comparison versus captopril

The present study was performed in order to compare the efficacy, safety, and tolerability of lisinopril, a long-acting angiotensin-converting enzyme (ACE) inhibitor, with captopril, the shorter acting ACE inhibitor available, in the treatment of elderly patients (mean age 70 +/- 0.5 years) with congestive heart failure (mean left ventricular ejection fraction 33.5 +/- 1%). The study was organized according to a double-blind, parallel-group, randomized multicenter protocol. After a 14-day placebo run-in period, patients were randomized to receive either lisinopril 5 mg orally once per day or captopril 12.5 mg orally once per day. The dose of the study drug could be doubled at 2-week intervals for 6 weeks. The maximal dose was lisinopril 20 mg once per day or captopril 25 mg twice per day. The addition of either captopril or lisinopril to a regimen of diuretics caused a significant increase in exercise tolerance assessed by bicycle ergometry after 12 weeks of treatment (530 +/- 21 seconds vs. 431 +/- 13 seconds, p < 0.01; 555 +/- 19 seconds vs. 463 +/- 12 seconds, p < 0.01, respectively). Both drugs significantly increased left ventricular ejection fraction and stroke volume, were equally effective in improving NYHA class, and were well tolerated, with no differences detectable between treatments. The results of this study indicate that lisinopril 5-20 mg once daily is at least as effective and well tolerated as captopril 12.5-50 mg daily in the treatment of elderly patients with congestive heart failure.

Long-term Treatment With Pravastatin Alone and in Combination With Gemfibrozil in Familial Type IIB Hyperlipoproteinemia or Combined Hyperlipidemia

BACKGROUND: Pravastatin inhibits 3-hydroxy-3-methylglutaryl-coenzyme A reductase. It prevents mevalonate synthesis, reducing endogenous cholesterol production, and reduces cholesterol content in the liver, thus resulting in a down-regulation of low-density lipoprotein receptor production. Gemfibrozil reduces very low-density lipoprotein production and low-density lipoprotein-cholesterol level and increases very low-density lipoprotein catabolism. Therefore, it was suggested that combination therapy with both drugs could effect greater reduction of cholesterol levels as compared to pravastatin alone. The present study was carried out to evaluate the efficacy and safety of pravastatin as a monotherapy or in combination with gemfibrozil in the treatment of patients with familial type IIb hyperlipoproteinemia or familial combined hyperlipidemia. METHODS AND RESULTS: Forty-one patients were included in the study. All patients initially followed 6 weeks of hypolipidemic diet; subsequently they were randomized and received either 20 mg once daily of pravastatin alone (n = 13) or 20 mg of pravastatin together with 600 mg of gemfibrozil twice daily (n = 14). As a control, 14 patients were treated with diet only. The treatment lasted 24 months and clinical evaluation and laboratory tests were done at given time points. Both groups of treated patients showed an early reduction (3 months) of total (about 30% P <.01 vs controls), low-density lipoprotein (about 35%, P <.01 vs controls) and very low-density lipoprotein cholesterol levels (about 18%, P = NS). In contrast, high-density lipoprotein cholesterol levels increased significantly in patients treated with pravastatin and gemfibrozil (about 20%, P <.05 vs controls). Pravastatin treatment alone reduced the level of serum triglycerides as efficiently as in combination with gemfibrozil. Data showed a sustained normalization of lipid profile until 24 months. However, this effect was achieved in patients that had rather low levels of triglycerides. During the treatment we did not observe any difference in the incidence of possible drug-related side effects. Severe myopathy or rhabdomyolysis was not observed at the doses of the drugs used in our study. CONCLUSIONS: Therapy with pravastatin and in combination with gemfibrozil resulted in significant and sustained normalization of lipid profile in high-risk patients with familial type IIb hyperlipoproteinemia or familial combined hyperlipidemia.

[Modification of some prothrombotic indices after treatment with iloprost in arterial disease patients]

The authors analyse the short-term and medium-term effects of iloprost prostanoid derivate on hemostatic status in a group of patients with obliterating vascular disease of the lower limbs. The study included 10 patients (6 males, 4 females; aged 52 + 5 years old) suffering from Fontaine's stage 3 obstructive arterial disease. After a 10-hour fast each patient received a 6-hour iv infusion of iloprost at a dose of 2 ng/kg/min (approx 50 gamma) a venous blood sample was collected before and after infusion. The test was repeated using the same method after 4 weeks of treatment with the same dose of the drug. The following parameters were analysed in serum: fibrinogen (F) (IL coagulometric method), Factor VII (F VII) (IL coagulometric method), antithrombin II (AT III) (IL chromogenic method), protein C (PC) II coagulometric method) and protein S (PS) (IL coagulometric method). After the first infusion a significant increase was observed in AT III (p > 0.05), whereas other indices showed no significant variations. After treatment for 4 weeks AT III was again enhanced after infusion (p > 0.05); with regard to the basal values of other parameters, a significant reduction (p > 0.05) was found in F VII, whereas no other significant changes were observed. In the light of these results the authors suggest an antithrombotic effect of the drug documented by the short-term increase in AT III probably due to lower consumption, and a medium-term reduction in F VII due to trophic effect of the drug at a vasculoparietal level resulting in the depression of FVII tissue activation factors.

[Hemostatic status in subjects with deep venous thrombosis]

The authors report a study on the hemostatic status of a group of patients with deep venous thrombosis in order to highlight the possible pathogenetic responsibility of blood coagulative disorders in the genesis of thrombosis. The group consisted of 27 patients (14 males, 13 females, mean age 48 +/- 4 years) with deep venous thrombosis of the lower limbs (clinical symptoms were primary in 21 cases, secondary in 6 cases) diagnosed on the basis of clinical data and ultrasonographic instrumental findings. Fourteen normal subjects were also examined as a control group (12 males, 2 females, mean age 28 +/- 5 years). Venous blood was collected on fasting from patients and controls to examine the following parameters: fibrinogen (F), factor VII (F VII), antithrombin III (AT III), protein C (PC), protein S (PS) using coagulometric methods (IL), and tissue plasminogen activator (tPA), plasminogen activator inhibitor (PAI-1), fibrinopeptide A (FPA), betathromboglobulin (BTG) and dimer-D (D-D) using ELISA methods (Boehringer). Patients with deep venous thrombosis showed a significant increase in F, FVII, tPA and D-D levels compared to controls, whereas a significant reduction was observed in PAI-1. Nonsignificant variations were found for AT III, PC, PS and BTG. In the light of these results the authors affirm that: high fibrinogen and factor VII levels are highly prognostic for thrombosis in patients with deep venous thrombosis; the importance of the lack of inhibitory factors (AT III, PC, PS) is confined to individual genetically predisposed cases; there is an efficacious hyperfibrinolytic reactive response to the presence of thrombus (increase in tPA and D-D, reduction of PAI-1).

Inotropic stimulation by dobutamine increases left ventricular regional function at the expense of metabolism in hibernating myocardium

The mechanism by which dobutamine increases the contraction of chronically dysfunctional myocardium and its effects on metabolism are still unknown. The aim of this study was to assess regional myocardial metabolism at rest and during an intracoronary dobutamine infusion in patients with hibernating myocardium. Eleven asymptomatic patients with single proximal stenosis of the left anterior descending coronary artery and persistent left ventricular dysfunction at rest (undergoing percutaneous transluminal coronary angioplasty [PTCA]) were studied prospectively. Regional left ventricular function was assessed by two-dimensional (2D) echocardiography and regional perfusion by thallium-201 single-proton-emission computed tomography. Great cardiac vein and aortic blood samples were obtained for measurements of lactate and plasma free fatty acid (FFA) concentrations. Inotropic challenge, obtained by using intracoronary dobutamine infusion, increases regional left ventricular function. However, the arteriovenous AV lactate difference was 0.206 = 0.070 mmol/L at rest, and it decreased to 0.018 = 0.069 mmol/L (p < 0.05 vs baseline) and 0.066 = 0.068 mmol/L (p < 0.05 vs baseline) at 4 and 10 minutes of dobutamine infusion, respectively. Thus the hibernating myocardium does not produce lactate at rest. However, when regional contraction is stimulated, dobutamine-induced inotropic challenge may cause a perfusion-contraction mismatch with an activation of anaerobic glycolysis.

Diastolic abnormalities in systemic sclerosis: evidence for associated defective cardiac functional reserve

OBJECTIVE

To investigate the pattern of diastolic abnormalities in patients with systemic sclerosis (SSc) and the relationship between impaired ventricular filling and systolic function.

METHODS

Twenty four patients with SSc underwent M-mode and two dimensional echocardiography using echo-Doppler and gated blood pool cardiac angiography, both at rest and after exercise.

RESULTS

An impaired diastolic relaxation of the left ventricle was detected in 10 of the 24 patients with SSc. Left ventricular ejection fraction at rest in these 10 patients with impaired ventricular filling did not differ from that in the remaining 14 patients, but eight of the 10 failed to increase their ejection fraction during exercise, compared with two of the 14 with normal ventricular filling (p = 0.003).

CONCLUSION

Impaired relaxation of the left ventricle is a recently described feature of scleroderma heart disease. Diastolic dysfunction in SSc could depend on myocardial fibrosis or myocardial ischaemia, or both. It was found to be associated with a defective cardiac functional reserve. However, its prognostic significance remains to be clarified.

[LDL oxidation in homozygous familial hypercholesterolemia: effects of selective LDL-apheresis treatment]

Homozygous familial hypercholesterolemia (HFH) results from a mutation affecting both the structure and function of a cell surface receptor that removes low density lipoproteins (LDL) from plasma. The disorder is characterized by autosomal dominant inheritance, a lifelong elevation in the concentration of LDL-bound cholesterol in blood and by cholesterol deposits that form xanthomas and early coronary artery disease. HFH patients, as a result of the increased levels and prolonged residence time of LDL in plasma, have a strong tendency toward accumulation of LDL-cholesterol in the arterial wall causing premature atherosclerosis. Selective LDL-apheresis (LA) on dextran/sulphate cellulose columns is the best therapy reducing mortality of these patients. We previously showed that prolonged lifelong enhanced LDL oxidation in HFH. LDL undergo oxidation before being taken up by macrophages then transformed into foam cells. At the present time, the relevance of the in vitro macrophages studies to the accumulation of cholesterol esters in scavenger cells of HFH patients is not yet established. The aim of this study was to investigate LDL oxidation, induced by xanthine (2 mM)+xanthine oxidase (100 mU), and cholesterol esterification in macrophages, in 8 HFH patients before and after LA. LDL peroxidation by conjugated-diene absorbance showed an increased resistance against oxidation after LA: lag time 129 +/- 25 vs 112 +/- 27 min, p < 0.05; diene production 9.1 +/- 2.1 vs 13.9 +/- 2.5 nM/min/mg LDL, p < 0.01. Peroxidation was also evaluated from lipid peroxides (158 +/- 34 vs 57 +/- 18 nM/mg protein after LA, p < 0.05) and malonyldialdehyde (38 +/- 12 vs 27 +/- 8 nM/mg protein after LA, p < 0.05) content. When oxidized LDL was run on polyacrylamide gel extensive apo-B100 fragmentation was observed in LDL before LA, vs a less fragmentation after LA. A similar reduction was obtained in LDL agarose mobility after LA (1.7 +/- 0.2 vs 2.5 +/- 0.2, p < 0.05). Cholesterol esterification in mouse peritoneal macrophages was also decreased after LA (8.5 +/- 1.8 vs 14.6 +/- 2.7 nM/mg cell protein/12 hours, p < 0.05). Vitamin E content of LDL (mg/g protein) was increased after LA (4.44 +/- 1.0 vs 3.9 +/- 1.2, p < 0.05). Thus, selective LA, not only decreases the pool of LDL, but it also induces changes that render LDL less susceptible to oxidation and decreased high cholesterol esterification in macrophages. The prevention of these mechanisms by LA contributes actively to retard atherogenesis in HFH patients.

Cardiopulmonary exercise response in patients with left ventricular dysfunction or heart failure: a noninvasive study by gas exchange and impedance cardiography monitoring

We investigated the upright bicycle exercise cardiopulmonary response in 20 patients with left ventricular dysfunction (LVD, secondary to previous myocardial infarction, left ventricular ejection fraction range 18-44%). Ten patients (48 +/- 7 years) asymptomatic (I NYHA class) without drug treatment (LVD group). The others (n = 10) (50 +/- 1 years) complained of dyspnea and/or fatigue despite therapy (NYHA II-III). They represented the heart failure (HF) group. Eight sedentary men (40 +/- 10 years) served as controls. Controls and patients performed stress testings under drug treatment, when administered. Anaerobic ventilatory threshold (ATge) was considered as an index of submaximal exercise while peak exercise VO2 (Peak VO2) was considered the maximal volitional exercise capacity. The ratio between minute ventilation (VE) to carbon dioxide release (VCO2) (VE/VCO2) was assessed to evaluate the ventilatory response during exercise. We coupled gas exchange assessment (2001, MGC) with noninvasive monitoring of stroke volume (SV) by impedance cardiography (NCCOM3, BOMED) and total systemic vascular resistances (TSVR; by auscultatory blood pressure measurement). In controls VO2 increase during exercise was related to higher heart rate (HR) and SV both from resting to ATge and from this point to the peak. TSVR declined during both steps. In patients with HF VO2 rose from resting to ATge (by faster HR and unchanged SV). VO2 increased slightly from this point to Peak VO2. This result was related to flat HR increase and unchanged SV as well as TSVR. In patients with LVD VO2 increased similarly to controls from resting to ATge and less above the threshold. In these patients both HR and SV increased during submaximal exercise. From ATge to Peak VO2 only HR increased. TSVR declined significantly similarly to controls. The VE/VCO2 ratio was higher at peak exercise in patients with HF compared to controls. Different determinants were demonstrated in patients with left ventricular dysfunction with mild or symptomatic chronic heart failure (CHF). These findings and the increased ventilatory response in patients with CHF can explain different changes of VO2 in these patients during submaximal and maximal voluntary exercise and contribute to explain exercise-induced exertion in these subjects.

Effects of tissue factor induced by oxygen free radicals on coronary flow during reperfusion

Tissue factor is a transmembrane protein that activates the extrinsic coagulation pathway by binding factor VII. Endothelial cells, being in contact with circulating blood, do not normally express tissue factor. Here we provide evidence that oxygen free radicals induce tissue factor messenger RNA transcription and expression of tissue factor procoagulant activity in endothelial cells in culture. Isolated, perfused rabbit hearts exposed to exogenous oxygen free radicals also showed a marked increase in tissue factor activity within the coronary circulation. Furthermore, in ex vivo and in vivo hearts subjected to ischemia and reperfusion, a condition associated with a production of oxygen free radicals in large amounts, a marked increase in tissue factor activity occurred. This phenomenon could be abolished by oxygen radical scavengers. This increase in tissue factor activity during postischemic reperfusion was accompanied by a significant decrease in coronary flow, suggesting that increase in tissue factor activity with the consequent activation of the coagulation cascade might impair coronary flow during reperfusion and possibly contribute to the occurrence of reperfusion injury.

Transition from asymptomatic left ventricular dysfunction to congestive heart failure

One of the main goals of modern management and care of heart failure is to prevent the disease to progress toward congestion and death. The achievement of such an objective may, in fact, guarantee a sufficient quality of life and reduce the exposure of patients to the most common life-threatening complications associated with the congestive stage of the disease. Early identification of left ventricular dysfunction as well as a better knowledge of the mechanisms that favor the progression to more advanced stages of heart failure are fundamental requirements for the proper treatment of asymptomatic heart failure and for preventing the transition to symptomatic and more severe heart failure. The authors reviewed the literature on this topic, with emphasis on a series of studies they performed, to characterize the pathophysiologic profile of mild heart failure and the mechanisms that are possibly involved in the progression to congestive heart failure.

Oxidative structural modifications of low density lipoprotein in homozygous familial hypercholesterolemia

Patients with homozygous familial hypercholesterolemia (FH), as a result of the increased levels and prolonged residence time of low density lipoprotein (LDL) in plasma, have a strong tendency toward accumulation of LDL-cholesterol in the arterial wall, causing premature atherosclerosis. This phenomenon may enhance per se the physiological degradation of both protein and lipid component of LDL, which be more susceptible to oxidative damage induced by oxygen radicals. It is well known that LDL may undergo oxidative modification before being taken up by macrophages which are then transformed into foam cells. It has been suggested that platelet-activating factor (PAF) may play an important role in atherogenesis and PAF catabolism is known to be mediated by serum acetylhydrolase, an enzyme that is normally associated with LDL. Thus, the present study was designed to investigate the structural properties of LDL, including acetylhydrolase activity, in homozygous FH as compared to normolipidemic subjects before and after xanthine/xanthine oxidase-mediated oxidation. We studied 8 homozygous FH patients matched with 8 normolipidemic volunteers. Lipids of LDL fraction were extracted and verified by thin layer chromatography (TLC) analysis. Fatty acids were methylated and injected into a gas chromatograph/mass spectrometer. Vitamin E in LDL was determined by high performance liquid chromatography (HPLC). As an index of susceptibility of LDL to oxidative modifications, the formation of lipid-conjugated dienes was continuously monitored at 234 nm. Lipid peroxidation was also evaluated from the amount of both lipid peroxides (LPO) and malonyldialdehyde (MDA) content. Apolipoprotein (apo) B-100 on LDL was carried on polyacrylamide and agarose gel electrophoresis. In the homozygous FH patients, the relative content of cholesteryl ester was slightly increased. Interestingly, the relative amount of arachidonic acid (20:4) was constantly increased in each lipid fraction in homozygous FH patients. The amount of vitamin E was not significantly different in the patient group from that in the control group. However, LDL from patients carried lower levels of vitamin E (nmol/mg LDL) than controls (2.7 +/- 0.4 vs. 2.9 +/- 0.3 P = NS). The results shows that lag time (min) was decreased (82 +/- 19 vs. 111 +/- 21; P < 0.05) and the maximal rate of diene production and total diene production was increased in homozygous FH patients. Mean levels of MDA were similar in both groups before oxidation, but levels after initiation of oxidation were significantly higher in the patient group. In contrast, mean levels of LPO were already higher in patients before oxidation (58 vs. 27 nmol/mg of protein; P < 0.05), and after initiation of oxidation were also significantly higher at each time points. When oxidized LDL was run on a polyacrylamide gel, an extensive apo B-100 fragmentation replaced by lower molecular mass fragments ranging from 45,000 to 205,000 m.wt., was observed only in LDL from homozygotes. Relative LDL agarose gel mobility shows that LDL from patients migrated higher than LDL of controls. Finally acetylhydrolase activity associated with LDL in patients was significantly reduced as compared to controls. Thus, in homozygous FH patients, LDL appeared more susceptible to oxidation in vitro; the indices for LDL oxidizability were all significantly different from those of controls. This phenomenon might be due to prolonged residence time of LDL in these patients, as suggested from high basal LPO levels and lower vitamin E levels carried by LDL. This hypothesis may explain together with the high content of arachidonic acid, the enhanced susceptibility of LDL from homozygous FH patients to oxidative damage.

Propionyl-L-carnitine in intermittent claudication: double-blind, placebo-controlled, dose titration, multicenter study

OBJECTIVES

The aim of this double-blind, placebo-controlled, dose titration, multicenter trial was to assess the efficacy and safety of propionyl-carnitine in intermittent claudication.

BACKGROUND

Human and animal studies indicate that propionyl-L-carnitine increases carnitine content and improves energy metabolism in the ischemic skeletal muscle.

METHODS

After a 2-week preliminary period to assess maximal walking distance, 245 patients were randomly assigned to receive propionyl-L-carnitine (n = 118) or placebo (n = 127). The initial oral dose of 500 mg twice daily was increased at 2-month intervals to 2 g/day and then to 3 g/day in patients showing improvement in treadmill performance < 30% over baseline. Efficacy analysis was conducted for the 214 patients who completed the 24 weeks of treatment by comparing the effect of placebo and propionyl-L-carnitine on day 180.

RESULTS

Analysis of variance showed a significant improvement of 73 +/- 9% (mean +/- SE) in maximal walking distance with propionyl-L-carnitine (n = 99) compared with 46 +/- 6% for placebo (n = 115, p = 0.03). For distance walked at onset of claudication, propionyl-L-carnitine showed about double the improvement of placebo; however, the difference was not statistically significant. There were no changes in electrocardiographic and routine biochemical and hematologic tests that would indicate an adverse effect of propionyl-L-carnitine. Adverse events requiring drug discontinuation (11 in the propionyl-L-carnitine group, 3 in the placebo group) were unrelated to study medication. The dose titration design of the study also provided information on the dose-response relation. Slightly less than 67% of patients were expected to improve their maximal walking distance by at least 30%, assuming 2 g/day of propionyl-L-carnitine (95% confidence interval 0.51 to 0.70). The response rate during the entire titration course was significantly in favor of propionyl-L-carnitine compared with placebo.

CONCLUSIONS

Although the precise mode of therapeutic action requires clarification, propionyl-L-carnitine, at a dose of 1 to 2 g/day, appears to be effective and well tolerated, with minimal adverse effects.

Radionuclide monitoring of cardiac adaptations to volume loading in patients with dilated cardiomyopathy and mild heart failure. Effects of angiotensin-converting enzyme inhibition

BACKGROUND

Cardiac adaptations to volume overload have been poorly investigated in heart failure. The aim of this study was to assess dynamic left ventricular responses to acute volume loading by continuous radionuclide monitoring in patients with asymptomatic to mildly symptomatic left ventricular dysfunction.

METHODS AND RESULTS

Left ventricular end-diastolic (EDV) and end-systolic (ESV) volumes, ejection fraction (EF), and peak filling rate (PFR) were monitored by a radionuclide detector (Vest) before and during volume expansion (sodium chloride, 0.9%, 0.25 mL.kg-1.min-1 for 2 hours) in 10 patients with idiopathic dilated cardiomyopathy (DCM) and mild heart failure (New York Heart Association class I or II, ejection fraction < 50%). The patients were studied off treatment and after 6 to 8 weeks of oral treatment with enalapril (5 mg/d). A control group of 11 age- and sex-matched healthy volunteers (N group) was also studied. In the N group, volume loading caused prompt and sustained increases of EDV, EF, and PFR (all P < .001), whereas ESV was progressively reduced (P < .001), and heart rate and blood pressure did not change. In contrast, in DCM, EDV showed a smaller increase than in the N group (two-way ANOVA: F = 5.98, P < .001), ESV increased (P < .001), and EF and PFR remained unchanged. After enalapril, the cardiac adaptations to volume loading were restored to normal. In particular, EDV, EF, and PFR increased (P < .001), and ESV was reduced (P < .001). In 6 additional DCM patients studied before and after 6 to 8 weeks of placebo treatment, left ventricular responses to volume loading remained unchanged.

CONCLUSIONS

Left ventricular dynamic adaptations to acute volume loading are compromised in patients with idiopathic DCM and mild heart failure. These impaired responses are ameliorated by treatment with enalapril.