Association of frailty index with perioperative mortality and in-hospital morbidity after elective lower extremity bypass

Objective

The frailty index has been linked to adverse outcomes after surgical procedures. In this study, we evaluated the association between frailty index and outcomes after elective lower extremity bypass (LEB) for lower extremity ischemia.

Tryptophan metabolites suppress the Wnt pathway and promote adverse limb events in chronic kidney disease

Chronic kidney disease (CKD) imposes a strong and independent risk for peripheral artery disease (PAD). While solutes retained in CKD patients (uremic solutes) inflict vascular damage, their role in PAD remains elusive. Here, we show that the dietary tryptophan-derived uremic solutes including indoxyl sulfate (IS) and kynurenine (Kyn) at concentrations corresponding to those in CKD patients suppress β-catenin in several cell types, including microvascular endothelial cells (ECs), inhibiting Wnt activity and proangiogenic Wnt targets in ECs. Mechanistic probing revealed that these uremic solutes downregulated β-catenin in a manner dependent on serine 33 in its degron motif and through the aryl hydrocarbon receptor (AHR). Hindlimb ischemia in adenine-induced CKD and IS solute–specific mouse models showed diminished β-catenin and VEGF-A in the capillaries and reduced capillary density, which correlated inversely with blood levels of IS and Kyn and AHR activity in ECs. An AHR inhibitor treatment normalized postischemic angiogenic response in CKD mice to a non-CKD level. In a prospective cohort of PAD patients, plasma levels of tryptophan metabolites and plasma’s AHR-inducing activity in ECs significantly increased the risk of future adverse limb events. This work uncovers the tryptophan metabolite/AHR/β-catenin axis as a mediator of microvascular rarefaction in CKD patients and demonstrates its targetability for PAD in CKD models.     

Evaluation of wound healing properties of Arrabidaea chica Verlot extract

ETHNOPHARMACOLOGICAL RELEVANCE: Arrabidaea chica Verlot. (Bignoniaceae), popularly known as Crajiru, has been traditionally used as wound healing agent. AIM OF THE STUDY: Investigate in vitro and in vivo healing properties of Arrabidaea chica leaves extract (AC). MATERIALS AND METHODS: AC was evaluated in vitro in fibroblast growth stimulation (0.25-250 microg/mL) and collagen production stimulation (250 microg/mL) assays. Allantoin (0.25-250 microg/mL) and vitamin C (25 microg/mL) were used as controls respectively. DPPH and Folin-Ciocalteau assays were used for antioxidant evaluation, using trolox (0.25-250 microg/mL) as reference antioxidant. To study wound healing properties in rats, AC (100mg/mL, 200 microL/wound/day) was topically administered during 10 days and wound area was evaluated every day. Allantoin (100mg/mL, 200 microL/wound/day) was used as standard drug. After treatment, wound sites were removed for histopathological analysis and total collagen determination. RESULTS: AC stimulated fibroblast growth in a concentration dependent way (EC50=30 microg/mL), increased in vitro collagen production and demonstrated moderate antioxidant capacity. In vivo, AC reduced wound size in 96%, whereas saline group showed only 36% wound healing. CONCLUSION: AC efficiency seems to involve fibroblast growing stimulus and collagen synthesis both in vitro and in vivo, beyond moderate scavenging activity, corroborating Crajiru folk use.     

Hyperperfusion Syndrome after Carotid Endarterectomy

The hyperperfusion syndrome is a rare delayed postoperative complication of carotid endarterectomy (CEA) characterized by headache and seizure, with or without intracranial edema or hemorrhage. Between January 1996 and December 2003, 1,602 CEAs were performed. Six patients (0.4%) developed symptoms of hyperperfusion within 2 weeks of surgery. All patients had critical stenoses, five ≥90% and one 80-90%, with poor backbleeding from the distal internal carotid artery noted at operation in all cases. Five patients were asymptomatic prior to operation; one had a hemispheric transient ischemic attack. Three patients had severe contralateral internal carotid disease (two occlusions and one severe stenosis). Two patients developed severe, self-limiting headache that prolonged hospitalization. Three patients had ipsilateral intracranial bleeding, two occurring after an uneventful postoperative course. After initial discharge from the hospital, severe intracranial hemorrhage caused death in two patients. One patient experienced focal seizures 1 week after discharge. Hypertension did not appear to be related to the symptoms in any case. During the study period, the hyperperfusion syndrome caused three of five perioperative strokes (60%) and two of seven deaths (29%) in the entire endarterectomy population. Although rare, the hyperperfusion syndrome accounts for a significant percentage of the neurological morbidity and mortality following CEA.Presented at the Twenty-second Annual Meeting of the Southern California Vascular Surgery Society, La Jolla, CA, April 30-May 2, 2004.     

Prognostic value of global myocardial performance indices in acute myocardial infarction: comparison to measures of systolic and diastolic left ventricular function

STUDY OBJECTIVES: Assessment of global myocardial performance by a single index (ie, the myocardial performance index [MPI]) has been suggested as an appealing alternative to the individual assessment of systolic and diastolic left ventricular (LV) function We sought to test the prognostic value of MPI in comparison to clinical characteristics and echocardiographic parameters of LV filling and ejection in acute myocardial infarction (AMI). PATIENTS: Four hundred seventeen consecutive patients with AMI were examined within 24 h of hospital admission. INTERVENTIONS: Doppler echocardiographic measures of systolic, diastolic, and global myocardial performance were assessed within 24 h of hospital admission. In addition to MPI (ie, the sum of the isovolumic time intervals divided by ejection time), we determined the isovolumic/heterovolumic time ratio, which expresses the time "wasted" by the myocardium to generate and decrease LV pressure without moving blood. RESULTS: The end points of the study at 30 days were death (4.7%), congestive heart failure (23%), and recurrent infarction (4.8%), and occurred in 109 patients, who were compared as group B to 314 patients without an event (group A). Multivariate analysis identified only age (odds ratio [OR], 1.04; 95% confidence interval [CI], 1.02 to 1.07), LV ejection fraction (LVEF) < or = 40% (OR, 3.82; 95% CI, 2.15 to 6.87), and E-wave deceleration time (EDT) of < or = 130 ms (OR, 2.29; 95% CI, 1.0 to 5.21) as independent predictors of adverse events. CONCLUSION: LVEF and EDT are powerful and independent echocardiographic predictors of poor outcome following AMI, and are superior to indexes of global LV performance. Both parameters should be taken into consideration when deciding about the management of these patients.     

From the Cover: Orientation saliency without visual cortex and target selection in archer fish

Our visual attention is attracted by salient stimuli in our environment and affected by primitive features such as orientation, color, and motion. Perceptual saliency due to orientation contrast has been extensively demonstrated in behavioral experiments with humans and other primates and is believed to be facilitated by the functional organization of the primary visual cortex. In behavioral experiments with the archer fish, a proficient hunter with remarkable visual abilities, we found an orientation saliency effect similar to that observed in human subjects. Given the enormous evolutionary distance between humans and archer fish, our findings suggest that orientation-based saliency constitutes a fundamental building block for efficient visual information processing.     

Repeat computed tomographic scan within 24-48 hours of admission in children with moderate and severe head trauma

OBJECTIVE: To asses the yield and contribution of a routine predetermined repeat head computed tomographic (CT) scan within 24-36 hrs in pediatric patients with moderate to severe head trauma. DESIGN: Records review. SETTING: Five pediatric intensive care units. PATIENTS: We reviewed the charts of 173 consecutive pediatric patients with moderate to severe head trauma (Glasgow Coma Scale score of < or = 11) that survived the first 24 hrs after being admitted to five Israeli trauma centers. Clinical data collected included status at admission, at the time between the first and second CT scans, and after the second scan. Head details of the first, second, and, if performed, third CT scan were collected. Treatment strategy during each period was recorded, including any change in treatment after each CT scan. MEASUREMENTS AND MAIN RESULTS: A total of 47 (27%) of the second CT scans showed new lesions including six intracranial hemorrhages, 17 cases of worsening brain edema, and 18 newly diagnosed brain contusions. However, none of these findings necessitated surgical intervention or any change in therapy. Of the 67 patients who underwent a third CT scan, two cases required surgical intervention because of new findings in the third CT. CONCLUSIONS: A second routine prescheduled head CT scan within 24-36 hrs after admission in pediatric patients with moderate to severe head trauma is unlikely to yield any change in therapy. Clinically and intracranial pressure-oriented CT scan may better select and diagnose patients who require changes in therapy, including surgery. Studies aimed to determine the ideal timing for the second are warranted.