Enalapril and acebutolol in essential arterial hypertension. Comparison of the 2 drugs and evaluation of their combination

The effects of a mid-term antihypertensive treatment with Acebutolol (A) 400 mg once-daily alone, Enalapril (E) 20 mg once-daily alone and their combination (A + E) in 12 hypertensive patients (pts.) have been evaluated. The diastolic (DBP) and systolic (SBP) blood pressure values have been evaluated in supine and upright position and at the end of an exercise test. Basic values obtained after 3 weeks of treatment with placebo have been matched with values observed after 3 months of each treatment (A; A + E; E). In order to evaluate the effectiveness of the combination, pts. were divided into two groups: the first group was given A, than A + E and finally E; in the second group the order was reversed. Our findings showed a more significant reduction of DBP in supine and upright position and after exercise (p less than .05) and of SBP in supine and upright position (p less than .05) after treatment with E. The addition of A to E did not produce a further significant reduction in blood pressure values except after exercise (p less than .01).     

Minimally invasive surgical implantation of left ventricular epicardial leads for ventricular resynchronization using video-assisted thoracoscopy

BACKGROUND AND OBJECTIVES: Cardiac resynchronization via left ventricular or biventricular pacing is an option for selected patients with ventricular systolic dysfunction and widened QRS complex. Stimulation through a coronary vein is the technique of choice for left ventricular pacing, but this approach results in a failure rate of approximately 8%. We describe our initial experience with minimally invasive surgical implantation of left ventricular epicardial leads using video-assisted thoracoscopy. PATIENTS AND METHOD: A total of 14 patients with congestive heart failure, NYHA functional class 3.2 (0.6) and mean ejection fraction 22.9 (6.8)% were included in this study. Left bundle branch block, QRS complex >140 ms and abnormal septal motion were observed in all cases. Epicardial leads were implanted on the left ventricular free wall under general anesthesia using video-assisted thoracoscopic surgery. RESULTS: Lead implantation was successful in 13 patients. Conversion to a small thoracotomy was necessary in one patient. All patients were extubated in the operating room. None of the patients died during their hospital stay. Follow-up showed reversal of ventricular asynchrony and significant improvement in ejection fraction and functional class. CONCLUSIONS: Minimally invasive surgery for ventricular resynchronization using video-assisted thoracoscopy in selected patients is a safe procedure that makes it possible to choose the best site for lead implantation and provides adequate short- and medium-term stimulation.     

How Does a Novel Monoplanar Pedicle Screw Perform Biomechanically Relative to Monoaxial and Polyaxial Designs?

Background

Minimally invasive spinal fusions frequently require placement of pedicle screws through small incisions with limited visualization. Polyaxial pedicle screws are favored due to the difficulty of rod insertion with fixed monoaxial screws. Recently, a novel monoplanar screw became available that is mobile in the coronal plane to ease rod insertion but fixed in the sagittal plane to eliminate head slippage during flexion loads; however, the strength of this screw has not been established relative to other available screw designs.

Questions/purposes

We compared the static and dynamic load to failure in polyaxial, monoaxial, and monoplanar pedicle screws.

Methods

Six different manufacturers’ screws (42 total) were tested in three categories (polyaxial, n = 4; monoaxial, n = 1; monopolar, n = 1) utilizing titanium rods. An additional test was performed using cobalt-chromium rods with the monopolar screws only. Screws were embedded into polyethylene blocks and rods were attached using the manufacturers’ specifications. Static and dynamic testing was performed. Dynamic testing began at 80% of static yield strength at 1 Hz for 50,000 cycles.

Results

In static testing, monoaxial and monoplanar screws sustained higher loads than all polyaxial screw designs (range, 37%–425% higher; p < 0.001). The polyaxial screws failed at the head-screw interface, while the monoaxial and monoplanar screws failed by rod breakage in the static test. The dynamic loads to failure were greater with the monoplanar and monoaxial screws than with the polyaxial screws (range, 35%–560% higher; p < 0.001). With dynamic testing, polyaxial screws failed via screw-head slippage between 40% and 95% of static yield strength, while failures in monoaxial and monoplanar screws resulted from either screw shaft or rod breakage.

Conclusions

All polyaxial screws failed at the screw-head interface in static and dynamic testing and at lower values than monoaxial/monoplanar screw designs. Monoplanar and monoaxial screws failed at forces well above expected in vivo values; this was not the case for most polyaxial screws.

Clinical Relevance

Polyaxial screw heads slip on the screw shank at lower values than monoaxial or monoplanar screws, and this results in angular change between the rod and pedicle screw, which could cause loss of segmental lordosis. The novel monoplanar screw used in this study may combine ease of rod placement with sagittal plane strength.     

Switching from high-dose clopidogrel to prasugrel in ACS patients undergoing PCI: a single-center experience

Prasugrel has been shown to be superior to clopidogrel in the setting of ACS patients undergoing coronary angioplasty. However, few data have been reported so far on those patients who switch from clopidogrel to prasugrel after coronary angioplasty. Aim of the current study was to evaluate the safety of prasugrel loading dose administration in ACS patients undergoing PCI and preatreated with high-dose clopidogrel. From May 2010 to December 2011 150 ACS patients undergoing coronary angioplasty and pretreated with high-dose clopidogrel, were switched to prasugrel loading dose soon after the procedure. They were matched (ratio 1:2) according to sex and age with a group of 300 ACS patients undergoing angioplasty and treated with high-dose clopidogrel only from May 2010 to December 2011. All demographic clinical and angiographic were collected. Primary endpoint was the rate of major bleeding complications (according to ACUITY trial definition) at 30-day follow-up. Secondary endpoints were: TIMI major and minor bleeding, definite stent thrombosis, major adverse cardiac events (MACE) and Net adverse cardiac events (NACE) at 30-day follow-up. The two groups of patients showed similar baseline demographic, and clinical characteristics. Most of the patients had unstable angina or non-ST segment elevation myocardial infarction. Almost (about 95 %) all patients underwent radial approach. No difference was observed in major bleeding complications according to both ACUITY (2.0 vs 2.0 %) and TIMI Major (0.7 vs 1.3 %) definition. No difference between the two groups was observed in terms of in-stent thrombosis, MACE and NACE at 30-day follow-up. Our observational study showed that switching to prasugrel with loading dose soon after angioplasty among ACS patients who were pretreated with clopidogrel seems to be well tolerated without overt evidence of heightened major bleeding. Future large randomized trials are certainly needed to confirm these findings.     

The Osteoprint: A bioinspired two-photon polymerized 3-D structure for the enhancement of bone-like cell differentiation

The need for a better understanding of cell behavior and for exploiting cell functions in various healthcare applications has driven biomedical research to develop increasingly complex fabrication strategies to reproduce the natural biological microenvironment in vitro. Different approaches have led to the development of refined examples of 2- and 3-D structures able to sustain cellular proliferation, differentiation and functionality very similar to those normally occurring in living organisms. One such approach is two-photon polymerization. In this paper, we present a trabecula-like structure (which we have named “Osteoprint”) that resembles to the typical microenvironment of trabecular bone cells. Starting from microtomography images of the trabecular bone, we prepared several Osteoprints through two-photon polymerization and tested the behavior of SaOS-2 bone-like cells cultured on our structures. Interestingly, we found that Osteoprints deeply affect cellular behavior, determining an exit from the cell cycle and an enhancement of osteogenic differentiation. Indeed, we found an up-regulation of the genes involved in SaOS-2 cell maturation and an increase in hydroxyapatite production and accumulation upon SaOS-2 culture on the Osteoprints. The findings we obtained are extremely interesting, and open up new perspectives in “bioinspired” approaches for tissue engineering and regenerative medicine.     

A New Anorganic Equine Bone Substitute for Oral Surgery: Structural Characterization and Regenerative Potential

Different xenogeneic inorganic bone substitutes are currently used as bone grafting materials in oral and maxillo-facial surgery. The aim of the present study was to determine the physicochemical properties and the in vivo performance of an anorganic equine bone (AEB) substitute. AEB is manufactured by applying a process involving heating at >300 °C with the aim of removing all the antigens and the organic components. AEB was structurally characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), X-ray fluorescence (XRF), and Fourier-transformed infrared (FT-IR) spectroscopy and compared to the anorganic bovine bone (ABB). In order to provide a preliminary evaluation of the in vivo performance of AEB, 18 bone defects were prepared and grafted with AEB (nine sites), or ABB (nine sites) used as a control, in nine Yucatan Minipigs. De novo bone formation, residual bone substitute, as well as local inflammatory and tissue effects were histologically evaluated at 30 and 90 days after implantation. The structural characterization showed that the surface morphology, particle size, chemical composition, and crystalline structure of AEB were similar to cancellous human bone. The histological examination of AEB showed a comparable pattern of newly formed bone and residual biomaterial to that of ABB. Overall, the structural data and pre-clinical evidence reported in the present study suggests that AEB can be effectively used as bone grafting material in oral surgery procedures.     

Can Fasting Curb the Metabolic Syndrome Epidemic?

Metabolic syndrome (MetS) represents a cluster of metabolic abnormalities that includes hypertension, central obesity, insulin resistance, and atherogenic dyslipidemia. Due to the high prevalence (around 1/3 of the world population) economic burden of MetS, there is a need for new dietary, lifestyle, and therapeutic options. Recently, fasting emerged as a dietary method proposed for controlling metabolic risk factors. Intermittent fasting (IF), or time-restricted feeding (TRF), describes an array of feeding patterns in which calorie intake is restricted to a specific time period. Hence, this review aimed to elucidate the latest data on MetS and explore the viability of simple management options, such as IF and TRF. Preclinical studies have shown how IF/TRF exerts beneficial effects on the gut microbiota, glucose and insulin metabolism, weight and visceral fat, and lipid metabolism. However, the results obtained from human studies are somewhat conflicting, as weight loss was achieved in all studies, whereas in some studies, there was no significant effect on insulin resistance, cholesterol/lipid metabolism, or blood pressure. Nevertheless, as only very few human studies were performed, there is a need for more randomized control trials on larger cohorts of patients with MetS to gather higher-yield evidence to clarify whether IF/TRF are suitable dietary patterns for this population.