Medical management for chronic atherosclerotic peripheral arterial disease

Construction of cyclopenta[b]dihydronaphthofurans via TsOH-catalyzed consecutive biscyclization of dithioallylic alcohols and 1-styrylnaphthols

An efficient TsOH-catalyzed consecutive biscyclization cascade reaction of dithioallylic alcohols with 1-styrylnaphthols is demonstrated for the concise construction of pharmaceutically important cyclopenta[b]dihydrobenzofuran scaffolds. This process involved an acid-catalyzed (3+2) cycloaddition followed by an intramolecular nucleophilic addition, providing cyclopenta[b]dihydronaphthofurans bearing a tetra- or fully substituted cyclopentane core in good yields with exclusive diastereoselectivities (>20 : 1 d.r.).

Systematic review of associations between concomitant rheumatoid arthritis and peripheral arterial disease, health-related quality of life and functional capacity

Patients with rheumatoid arthritis (RA) are at an increased risk of cardiovascular disease and vascular morbidity. The association between peripheral arterial disease (PAD) and RA has not been previously investigated within the scope of a review. Conjoined disease manifestations may impact patient well-being, perpetuating increased mortality and quality of life deficits. To investigate the association between RA and PAD, along with RA and the ankle-brachial pressure index (ABPI), the impact of disease concomitance on health-related quality of life (HRQOL) and functional capacity (FC) was also investigated. Individual study appraisal was completed using the Crowe Critical Appraisal Tool (CCAT). A level of evidence analysis was conducted using the American Society of Plastic Surgeons (ASPS) Evidence Rating Scale for Prognostic/Risk Studies. AMED^®, CINAHL^®, Health Source: Nursing/Academic Edition, MEDLINE^®, AHFS^®, Scopus, Web of Science, Cochrane Library and Google scholar. Ten studies produced a CCAT rating of ≥ 30 (75%) and were deemed high quality, while a single study demonstrated a score of 26 (65%) suggesting moderate quality. A grade "II" levels of evidence was awarded to positive association between RA and PAD. A gradation of "I" was awarded to the association between ABPI and RA. The impact of concomitant manifestations on HRQOL and FC did not qualify for a level of evidence analysis. The systematic inflammatory nature of RA likely contributes to the increased incidence of PAD within the population. Further investigations are required to ascertain the impact of conjoined disease manifestations on HRQOL and FC.

Interleukin 1β inhibition contributes to the antinociceptive effects of voluntary exercise on ischemia/reperfusion-induced hypersensitivity

Issues of peripheral circulation have been increasingly suggested as an underlying cause of musculoskeletal pain in many conditions, including sickle cell anemia and peripheral vascular disease. We have previously shown in our model of transient ischemia and reperfusion (I/R) injury of the forelimb that individual group III and IV muscle afferents display altered chemosensitivity and mechanical thresholds 1 day after injury. Functional alterations corresponded to increased evoked and spontaneous pain-related behaviors and decreased muscle strength and voluntary activity-all actions that echo clinical symptoms of ischemic myalgia. These behavioral and physiological changes appeared to originate in part from the action of increased interleukin 1β (IL1β) in the injured muscles at its upregulated IL1 receptor 1 within the dorsal root ganglion. Here, we describe that two days of voluntary wheel running prior to I/R blocks both injury-induced IL1β enhancement and the subsequent development of ischemic myalgia-like behaviors. Furthermore, the protective effects of 2 days prior exercise on the I/R-evoked increases in pain-related behaviors were also paralleled with systemic injection of the IL1 receptor antagonist during I/R. Interleukin 1 receptor antagonist treatment additionally prevented the I/R-induced changes in mechanical and chemical sensitivity of individual primary muscle afferents. Altogether, these data strengthen the evidence that transient I/R injury sensitizes group III and IV muscle afferents via increased IL1β in the muscles to stimulate ischemic myalgia development. Targeting IL1β may, therefore, be an effective treatment strategy for this insidious type of muscle pain.

Drug-eluting balloon angioplasty versus uncoated balloon angioplasty for the treatment of in-stent restenosis of the femoropopliteal arteries

BACKGROUND

Stents are placed in the femoropopliteal arteries for numerous reasons, such as atherosclerotic disease, the need for dissection, and perforation of the arteries, and can become stenosed with the passage of time. When a stent develops a flow-limiting stenosis, this process is known as "in-stent stenosis." It is thought that in-stent restenosis is caused by a process known as "intimal hyperplasia" rather than by the progression of atherosclerotic disease. Management of in-stent restenosis may include performing balloon angioplasty, deploying another stent within the stenosed stent to force it open, and creating a bypass to deliver blood around the stent. The role of drug-eluting technologies, such as drug-eluting balloons (DEBs), in the management of in-stent restenosis is unclear. Drug-eluting balloons might function by coating the inside of stenosed stents with cytotoxic chemicals such as paclitaxel and by inhibiting the hyperplastic processes responsible for in-stent restenosis. It is important to perform this systematic review to evaluate the efficacy of DEB because of the potential for increased expenses associated with DEBs over uncoated balloon angioplasty, also known as plain old balloon angioplasty (POBA).

OBJECTIVES

To assess the safety and efficacy of DEBs compared with uncoated balloon angioplasty in people with in-stent restenosis of the femoropopliteal arteries as assessed by criteria such as amputation-free survival, vessel patency, target lesion revascularization, binary restenosis rate, and death. We define "in-stent restenosis" as 50% or greater narrowing of a previously stented vessel by duplex ultrasound or angiography.

SEARCH METHODS

The Cochrane Vascular Information Specialist searched the Cochrane Vascular Specialised Register, CENTRAL, MEDLINE, Embase, and CINAHL databases and the World Health Organization International Clinical Trials Registry Platform and ClinicalTrials.gov trials registers to November 28, 2017. Review authors also undertook reference checking to identify additional studies.

SELECTION CRITERIA

We included all randomized controlled trials that compared DEBs versus uncoated balloon angioplasty for treatment of in-stent restenosis in the femoropopliteal arteries.

DATA COLLECTION AND ANALYSIS

Two review authors (AK, WA) independently selected appropriate trials and performed data extraction, assessment of trial quality, and data analysis. The senior review author (AD) adjudicated any disagreements.

MAIN RESULTS

Three trials that randomized a combined total of 263 participants met the review inclusion criteria. All three trials examined the treatment of symptomatic in-stent restenosis within the femoropopliteal arteries. These trials were carried out in Germany and Austria and used paclitaxel as the agent in the drug-eluting balloons. Two of the three trials were industry sponsored. Two companies manufactured the drug-eluting balloons (Eurocor, Bonn, Germany; Medtronic, Fridley, Minnesota, USA). The trials examined both anatomical and clinical endpoints. We noted heterogeneity in the frequency of bailout stenting deployment between studies as well as in the dosage of paclitaxel applied by the DEBs. Using GRADE assessment criteria, we determined that the certainty of evidence presented was very low for the outcomes of amputation, target lesion revascularization, binary restenosis, death, and improvement of one or more Rutherford categories. Most participants were followed up to 12 months, but one trial followed participants for up to 24 months.Trial results show no difference in the incidence of amputation between DEBs and uncoated balloon angioplasty. DEBs showed better outcomes for up to 24 months for target lesion revascularization (odds ratio (OR) 0.05, 95% confidence Interval (CI) 0.00 to 0.92 at six months; OR 0.24, 95% CI 0.08 to 0.70 at 24 months) and at six and 12 months for binary restenosis (OR 0.28, 95% CI 0.14 to 0.56 at six months; OR 0.34, 95% CI 0.15 to 0.76 at 12 months). Participants treated with DEBs also showed improvement of one or more Rutherford categories at six and 12 months (OR 1.81, 95% CI 1.02 to 3.21 at six months; OR 2.08, 95% CI 1.13 to 3.83 at 12 months). Data show no clear differences in death between DEBs and uncoated balloon angioplasty. Data were insufficient for subgroup or sensitivity analyses to be conducted.

AUTHORS' CONCLUSIONS

Based on a meta-analysis of three trials with 263 participants, evidence suggests an advantage for DEBs compared with uncoated balloon angioplasty for anatomical endpoints such as target lesion revascularization (TLR) and binary restenosis, and for one clinical endpoint - improvement in Rutherford category post intervention for up to 24 months. However, the certainty of evidence for all these outcomes is very low due to the small number of included studies and participants and the high risk of bias in study design. Adequately powered and carefully constructed randomized controlled trials are needed to adequately investigate the role of drug-eluting technologies in the management of in-stent restenosis.

Phosphine-catalyzed dearomative (3 + 2) annulation of 2-nitrobenzofurans and nitrobenzothiophenes with allenoates

An efficient Ph₂PMe-catalyzed dearomative (3 + 2) annulation of 2-nitrobenzofurans, 2-nitrobenzothiophenes, and 3-nitrobenzothiophenes with allenoates is reported.

Sex differences in primary muscle afferent sensitization following ischemia and reperfusion injury

BACKGROUND

Chronic pain conditions are more prevalent in women, but most preclinical studies into mechanisms of pain generation are performed using male animals. Furthermore, whereas group III and IV nociceptive muscle afferents provoke central sensitization more effectively than their cutaneous counterparts, less is known about this critical population of muscle nociceptors. Here, we compare the physiology of individual muscle afferents in uninjured males and females. We then characterize the molecular, physiological, and behavioral effects of transient ischemia and reperfusion injury (I/R), a model we have extensively studied in males and in females.

METHODS

Response properties and phenotypes to mechanical, thermal, and chemical stimulation were compared using an ex vivo muscle/nerve/dorsal root ganglia (DRG)/spinal cord recording preparation. Analyses of injury-related changes were also performed by assaying evoked and spontaneous pain-related behaviors, as well as mRNA expression of the affected muscle and DRGs. The appropriate analyses of variance and post hoc tests (with false discovery rate corrections when needed) were performed for each measure.

RESULTS

Females have more mechanically sensitive muscle afferents and show greater mechanical and thermal responsiveness than what is found in males. With I/R, both sexes show fewer cells responsive to an innocuous metabolite solution (ATP, lactic acid, and protons), and lower mechanical thresholds in individual afferents; however, females also possess altered thermal responsiveness, which may be related to sex-dependent changes in gene expression within the affected DRGs. Regardless, both sexes show similar increases in I/R-induced pain-like behaviors.

CONCLUSIONS

Here, we illustrate a unique phenomenon wherein discrete, sex-dependent mechanisms of primary muscle afferent sensitization after ischemic injury to the periphery may underlie similar behavioral changes between the sexes. Furthermore, although the group III and IV muscle afferents are fully developed functionally, the differential mechanisms of sensitization manifest prior to sexual maturity. Hence, this study illustrates the pressing need for further exploration of sex differences in afferent function throughout the lifespan for use in developing appropriately targeted pain therapies.

Enantioselective synthesis of cyclopenta[b]benzofurans via an organocatalytic intramolecular double cyclization

An enantioselective organocatalytic strategy, combining Brønsted base and N-heterocyclic carbene catalysis in a unique manner, is demonstrated for a concise construction of the privileged cyclopenta[b]benzofuran scaffold, present in many bioactive compounds having both academic and commercial interests. The reaction concept relies on an intramolecular one-pot double cyclization involving a cycle-specific enantioselective Michael addition followed by a benzoin condensation of ortho-substituted cinnamaldehydes. Cyclopenta[b]benzofurans were achieved in moderate to good yields, with excellent stereoselectivities. A proof of principle for a diastereodivergent variation is demonstrated through the synthesis of cyclopenta[b]benzofurans containing two contiguous aromatic substituents in a substitution pattern present in commercial and natural compounds. Furthermore, several transformations have been performed, demonstrating the synthetic utility of the products. Finally, insights into the activation mode and stereoindution models are presented for this new synthetic strategy.

Muscle IL1β Drives Ischemic Myalgia via ASIC3-Mediated Sensory Neuron Sensitization

Musculoskeletal pain is a significantly common clinical complaint. Although it is known that muscles are quite sensitive to alterations in blood flow/oxygenation and a number of muscle pain disorders are based in problems of peripheral perfusion, the mechanisms by which ischemic-like conditions generate myalgia remain unclear. We found, using a multidisciplinary experimental approach, that ischemia and reperfusion injury (I/R) in male Swiss Webster mice altered ongoing and evoked pain-related behaviors in addition to activity levels through enhanced muscle interleukin-1 beta (IL1β)/IL1 receptor signaling to group III/IV muscle afferents. Peripheral sensitization depended on acid-sensing ion channels (ASICs) because treatment of sensory afferents in vitro with IL1β-upregulated ASIC3 in single cells, and nerve-specific knock-down of ASIC3 recapitulated the results of inhibiting the enhanced IL1β/IL1r1 signaling after I/R, which was also found to regulate afferent sensitization and pain-related behaviors. This suggests that targeting muscle IL1β signaling may be a potential analgesic therapy for ischemic myalgia.

SIGNIFICANCE STATEMENT

Here, we have described a novel pathway whereby increased inflammation within the muscle tissue during ischemia/reperfusion injury sensitizes group III and IV muscle afferents via upregulation of acid-sensing ion channel 3 (ASIC3), leading not only to alterations in mechanical and chemical responsiveness in individual afferents, but also to pain-related behavioral changes. Furthermore, these I/R-induced changes can be prevented using an afferent-specific siRNA knock-down strategy targeting either ASIC3 or the upstream mediator of its expression, interleukin 1 receptor 1. Therefore, this knowledge may contribute to the development of alternative therapeutics for muscle pain and may be especially relevant to pain caused by issues of peripheral circulation, which is commonly observed in disorders such as complex regional pain syndrome, sickle cell anemia, or fibromyalgia.

Same-day discharge after angioplasty for peripheral vascular disease: is it a safe and feasible option?

Peripheral vascular disease affects 20% of the population >55 years of age. Patients who become symptomatic are managed by a number of technique's including medical management, percutaneous angioplasty, bypass surgery, and in nonreconstructable situations, limb amputation. Clinicians treating patients by means of angioplasty have traditionally carried out these procedures on an inpatient basis. Limited resources and pressure on the availability of inpatient beds has necessitated clinicians to reevaluate how many of these patients are managed. Treating suitable patients as day cases is an attractive option that frees up resources and is financially advantageous. This paper examines the feasibility of same-day discharge after angioplasty, with a particular emphasis on achieving safe patient outcomes. It explores how advances in endovascular technologies and techniques have contributed to making same-day discharge an ever more feasible option. Nurse led pre-admission clinics run by specialist nurses facilitate safe and appropriate patient selection, where patients at risk for postprocedural problems can be identified effectively based on predefined clinical criteria.

Study of pentoxifylline effects on motility and viability of spermatozoa from infertile asthenozoospermic males

BACKGROUND

The quality of semen is one of the major parameters in male infertility. Pentoxifylline, a methylxanthine derivative, is an agent primarily used in the treatment of intermittent claudication and other vascular disorders. Studies have shown that pentoxifylline enhances the quality and quantity of sperms. In this study, we have investigated the in vitro effects of pentoxifylline on viability and motility of spermatozoa in samples of infertile oligoasthenozoospermic males.

MATERIALS AND METHODS

In this observer-blinded clinical trial, semen samples of 25 infertile oligoasthenozoospermic males were collected in Alzahra Educational Medical Center of Tabriz University of Medical Sciences from August 2010 to August 2012. After the isolation of spermatozoa by the swim-up method, they were randomized into four groups in ISM1 environment: The controls treated normally: Group 1 treated by pentoxifylline at a dose of 50 μg/ml, Group 2 treated by pentoxifylline at a dose of 100 μg/ml, and Group 3 treated by pentoxifylline at a dose of 200 μg/ml. Sperm viability and motility were compared among the groups on 45 min, 24 h, 36 h, and 48 h intervals.

RESULTS

Mean percentages of live sperms were 98.40%, 51.40%, 20.60%, and 6.00% in control group and 98.40%, 69.20%, 38.60%, and 14.60% in Group 3 on the mentioned intervals, respectively. This mean percentage decrease of live sperms was significantly lower in Group 3 comparing with that of other groups (P = 0.01). Mean percentages of motile sperms were 54%, 8.40%, 2.80%, and 0% in control group; and 54%, 16%, 4.80%, and 1.40% in Group 3 on the mentioned intervals, respectively. There was not a significant difference between the four groups in this regard (P = 0.19).

CONCLUSION

Pentoxifylline can enhance the viability of sperm of infertile oligoasthenozoospermic males with no significant effect on its motility.

Sensitization of group III and IV muscle afferents in the mouse after ischemia and reperfusion injury

Ischemic myalgia is a unique type of muscle pain in the patient population. The role that discrete muscle afferent subpopulations play in the generation of pain during ischemic events, however, has yet to be determined. Using 2 brachial artery occlusion models to compare prolonged ischemia or transient ischemia with reperfusion of the muscles, we found that both injuries caused behavioral decrements in grip strength, as well as increased spontaneous pain behaviors. Using our ex vivo forepaw muscles, median and ulnar nerves, dorsal root ganglion, and spinal cord recording preparation, we found after both prolonged and transient ischemia that there was a significant increase in the number of afferents that responded to both noxious and non-noxious chemical (lactate, adenosine triphosphate, varying pH) stimulation of the muscles compared to uninjured controls. However, we found an increase in firing to heat stimuli specifically in muscle afferents during prolonged ischemia, but a distinct increase in afferent firing to non-noxious chemicals and decreased mechanical thresholds after transient ischemia. The unique changes in afferent function observed also corresponded with distinct patterns of gene expression in the dorsal root ganglia. Thus, the development of ischemic myalgia may be generated by unique afferent-based mechanisms during prolonged and transient ischemia.

PERSPECTIVE

This study analyzed the response properties of thinly myelinated group III and unmyelinated group IV muscle afferents during prolonged and transient ischemia in addition to pain behaviors and alterations in DRG gene expression in the mouse. Results suggest that mechanisms of pain generation during prolonged ischemia may be different from ischemia/reperfusion.

Long Term Stability Evaluation of Prostacyclin Released from Biomedical Device through Turbiscan Lab Expert

Therapeutic guidelines indicate prostacyclin as the first line of treatment in inflammation and vascular diseases. Prostacyclins prevent formation of the platelet plug involved in primary hemostasis by inhibiting platelet activation and, combined with thromboxane, are effective vasodilators in vascular damage. Trans-Atlantic Inter-Society Consensus Document on Management of Peripheral Arterial Disease II guidelines indicates prostacyclins; in particular, Iloprost, as the first therapeutic option for treating peripheral arterial disease. However, therapeutic efficacy of Iloprost has witnessed several drawbacks that have occurred in patients receiving repeated weekly administration of the drug by intravenous infusions. Adverse reactions arose under perfusion with Iloprost for 6 h and patient compliance was drastically decreased. Biomedical devices could provide a suitable alternative to overcome these drawbacks. In particular, elastomeric pumps, filled with Iloprost isotonic solution, could slowly release the drug, thus decreasing its side effects, representing a valid alternative to hospitalization of patients affected by peripheral arterial disease. However, the home therapy treatment of patients requires long-term stability of Iloprost in solution-loaded elastomeric pumps. The aim of this work was to investigate the long-term stability of Iloprost isotonic solution in biomedical devices using Turbiscan technology. Turbiscan Lab Expert (L'Union, France) predicts the long-term stability of suspensions, emulsions and colloidal formulations by measuring backscattering and transmission of particulates dispersed in solution. The formulations were evaluated by measuring the variation of physical-chemical properties of colloids and suspensions as a function of backscattering and transmission modifications. In addition, the release profile of Iloprost isotonic solution from the biomedical device was evaluated.

Carnitine deficiency in chronic critical illness

PURPOSE OF REVIEW

New insight in mitochondrial physiology has highlighted the importance of mitochondrial dysfunction in the metabolic and neuroendocrine changes observed in patients presenting with chronic critical illness. This review highlights specifically the importance of carnitine status in this particular patient population and its impact on beta-oxidation and mitochondrial function.

RECENT FINDINGS

The main function of carnitine is long chain fatty acid esterification and transport through the mitochondrial membrane. Carnitine depletion should be suspected in critically ill patients with risk factors such as prolonged continuous renal replacement therapy or chronic parenteral nutrition, and evidence of beta-oxidation impairments such as inappropriate hypertriglyceridemia or hyperlactatemia. When fatty acid oxidation is impaired, acyl-CoAs accumulate and deplete the CoA intramitochondrial pool, hence causing a generalized mitochondrial dysfunction and multiorgan failure, with clinical consequences such as muscle weakness, rhabdomyolysis, cardiomyopathy, arrhythmia or sudden death. In such situations, carnitine plasma levels should be measured along with a complete assessment of plasma amino acid, plasma acylcarnitines and urinary organic acid analysis. Supplementation should be initiated if below normal levels (20 μmol/l) of carnitine are observed. In the absence of current guidelines, we recommend an initial supplementation of 0.5-1 g/day.

SUMMARY

Metabolic modifications associated with chronic critical illness are just being explored. Carnitine deficiency in critically ill patients is one aspect of these profound and complex changes associated with prolonged stay in ICU. It is readily measurable in the plasma and can easily be substituted if needed, although guidelines are currently missing.