Cryptospores and cryptophytes reveal hidden diversity in early land floras.

Cryptospores, recovered from Ordovician through Devonian rocks, differ from trilete spores in possessing distinctive configurations (i.e. hilate monads, dyads, and permanent tetrads). Their affinities are contentious, but knowledge of their relationships is essential to understanding the nature of the earliest land flora. This review brings together evidence about the source plants, mostly obtained from spores extracted from minute, fragmented, yet exceptionally anatomically preserved fossils. We coin the term 'cryptophytes' for plants that produced the cryptospores and show them to have been simple terrestrial organisms of short stature (i.e. millimetres high). Two lineages are currently recognized. Partitatheca shows a combination of characters (e.g. spo-rophyte bifurcation, stomata, and dyads) unknown in plants today. Lenticulatheca encompasses discoidal sporangia containing monads formed from dyads with ultrastructure closer to that of higher plants, as exemplified by Cooksonia. Other emerging groupings are less well characterized, and their precise affinities to living clades remain unclear. Some may be stem group embryophytes or tracheophytes. Others are more closely related to the bryophytes, but they are not bryophytes as defined by extant representatives. Cryptophytes encompass a pool of diversity from which modern bryophytes and vascular plants emerged, but were competitively replaced by early tracheophytes. Sporogenesis always produced either dyads or tetrads, indicating strict genetic control. The long-held consensus that tetrads were the archetypal condition in land plants is challenged.

Effect of an implantable gentamicin-collagen sponge on sternal wound infections following cardiac surgery: a randomized trial.

CONTEXT: Despite the routine use of prophylactic systemic antibiotics, sternal wound infection still occurs in 5% or more of cardiac surgical patients and is associated with significant excess morbidity, mortality, and cost. The gentamicin-collagen sponge, a surgically implantable topical antibiotic, is currently approved in 54 countries. A large, 2-center, randomized trial in Sweden reported in 2005 that the sponge reduced surgical site infection by 50% in cardiac patients. OBJECTIVE: To test the hypothesis that the sponge prevents infection in cardiac surgical patients at increased risk for sternal wound infection. DESIGN, SETTING, AND PARTICIPANTS: Phase 3 single-blind, prospective randomized controlled trial, 1502 cardiac surgical patients at high risk for sternal wound infection (diabetes, body mass index >30, or both) were enrolled at 48 US sites between December 21, 2007, and March 11, 2009. INTERVENTION: Single-blind randomization to insertion of 2 gentamicin-collagen sponges (total gentamicin of 260 mg) between the sternal halves at surgical closure (n = 753) vs no intervention (control group: n = 749). All patients received standardized care including prophylactic systemic antibiotics and rigid sternal fixation. MAIN OUTCOME MEASURES: The primary end point was sternal wound infection occurring through 90 days postoperatively as adjudicated by a clinical events classification committee blinded to study treatment group. The primary study comparison was done in the intent-to-treat population. Secondary outcomes included (1) superficial wound infection (involving subcutaneous tissue but not extending down to sternal fixation wires), (2) deep wound infection (involving the sternal wires, sternal bone, and/or mediastinum), and (3) score for additional treatment, presence of serous discharge, erythema, purulent exudate, separation of the deep tissues, isolation of bacteria, and duration of inpatient stay (ASEPSIS; minimum score of 0 with no theoretical maximum). RESULTS: Of 1502 patients, 1006 had diabetes (67%) and 1137 were obese (body mass index >30) (76%). In the primary analysis, there was no significant difference in sternal wound infection in 63 of 753 patients randomized to the gentamicin-collagen sponge group (8.4%) compared with 65 of 749 patients randomized to the control group (8.7%) (P = .83). No significant differences were observed between the gentamicin-collagen sponge group and the control group, respectively, in superficial sternal wound infection (49/753 [6.5%] vs 46/749 [6.1%]; P = .77), deep sternal wound infection (14/753 [1.9%] vs 19/749 [2.5%]; P = .37), ASEPSIS score (mean [SD], 1.9 [6.4] vs 2.0 [7.2]; P = .67), or rehospitalization for sternal wound infection (23/753 [3.1%] vs 24/749 [3.2%]; P = .87). CONCLUSION: Among US patients with diabetes, high body mass index, or both undergoing cardiac surgery, the use of 2 gentamicin-collagen sponges compared with no intervention did not reduce the 90-day sternal wound infection rate. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT00600483.

Treatment of pulmonary embolism with argatroban and ultrasound-assisted catheter-directed thrombolysis with alteplase in a patient with heparin-induced thrombocytopenia.

PURPOSE: Successful ultrasound-assisted catheter-directed thrombolysis (USAT) with low-dose alteplase and argatroban in a patient with bilateral pulmonary embolism (PE) secondary to heparin-induced thrombocytopenia (HIT) is reported. SUMMARY: HIT is a life-threatening complication associated with a high risk of thromboembolism. Systemic anticoagulation for the treatment of thrombosis may not be sufficient in the presence of PE. Catheter-directed treatment may be indicated in patients with PE and associated right ventricular dysfunction. Literature describing the use of nonheparin anticoagulation with catheter-directed thrombolysis in the setting of HIT, particularly in the context of PE, is limited. A 76-year-old Caucasian woman with recent cardiac surgery was hospitalized with bilateral PE. Unfractionated heparin was initiated, but the patient was switched to argatroban upon suspicion of HIT due to recent heparin exposure. The patient clinically improved and was switched to rivaroxaban on hospital day 7 for long-term anticoagulation. She developed worsening dyspnea on hospital day 9, and a computed tomography angiogram revealed an increased clot burden. On hospital day 12, the patient underwent USAT with alteplase and argatroban using the EkoSonic Endovascular System (EKOS Corporation, Bothell, WA). The catheters and sheaths were removed after approximately 20 hours, and the patient had marked hemodynamic improvement with reduced bilateral pulmonary arterial pressure. She was transitioned to warfarin therapy and discharged on hospital day 19. CONCLUSION: A woman with HIT and bilateral PE was successfully treated with the combination of argatroban and USAT with alteplase.

Early experience treating tricuspid valve endocarditis with a novel extracellular matrix cylinder reconstruction.

OBJECTIVE: The short-term outcomes were evaluated in patients treated for tricuspid valve endocarditis using a novel extracellular matrix (ECM) cylinder reconstruction technique. METHODS: Patients with clinically significant tricuspid regurgitation whose valves were not repairable by conventional techniques underwent valve replacement with a cylindrical construct sewn out of CorMatrix ECM (CorMatrix Cardiovascular, Roswell, Ga). The cylinders were sized to the native valve dimensions and attached distally to the papillary muscles using polypropylene sutures and ECM pledgets, and proximally to the annulus using a running suture. Patient data were collected retrospectively. RESULTS: From November 2011 to October 2013, 12 surgeons performed 19 tricuspid valve cylinder reconstructions in 8 men and 10 women (age range, 19-53 years). Of the 19 patients, 11 had active and 5 had treated endocarditis. One case was robotic-assisted. No deaths occurred, and no new cases of heart block developed. The papillary attachments were disrupted intraoperatively in 1 patient and after 7 days in another; both were successfully revised. A third patient experienced recurrent disruption of the implant at 13 and 22 months and ultimately received a pericardial valve. Fungal infection occurred in 1 cylinder at 6 months; a second ECM cylinder was implanted. Follow-up data were available for 13 patients at 1 to 2 months, 8 at 6 months, and 3 at 12 and 18 months. Other than patients undergoing reoperation, all showed well-functioning tricuspid valves with no to mild regurgitation. CONCLUSIONS: Cylinder reconstruction with ECM could be a suitable technique for replacing the tricuspid valve while preserving annuloventricular continuity in patients with infective endocarditis not repairable by conventional techniques.

Segmentation of cortical MS lesions on MRI using automated laminar profile shape analysis.

Cortical multiple sclerosis lesions are difficult to detect in magnetic resonance images due to poor contrast with surrounding grey matter, spatial variation in healthy grey matter and partial volume effects. We propose using an observer-independent laminar profile-based parcellation method to detect cortical lesions. Following cortical surface extraction, profiles are extended from the white matter surface to the grey matter surface. The cortex is parcellated according to profile intensity and shape features using a k-means classifier. The method is applied to a high-resolution quantitative magnetic resonance data set from a fixed post mortem multiple sclerosis brain, and validated using histology.

Sternal non-union in a professional hockey player: considerations for return to play.

We describe a healthy 40-year old professional hockey player with an asymptomatic sternal non-union following aortic root surgery. The purpose of this case report is to make orthopedic surgeons aware of the possibility of this complication following sternotomy, and to discuss the considerations involved in return to play in contact sports. We will discuss our work-up, evaluation, and management of a sternal non-union in a professional athlete. Patient's consent has been obtained.