Federated learning for predicting clinical outcomes in patients with COVID-19

Federated learning (FL) is a method used for training artificial intelligence models with data from multiple sources while maintaining data anonymity, thus removing many barriers to data sharing. Here we used data from 20 institutes across the globe to train a FL model, called EXAM (electronic medical record (EMR) chest X-ray AI model), that predicts the future oxygen requirements of symptomatic patients with COVID-19 using inputs of vital signs, laboratory data and chest X-rays. EXAM achieved an average area under the curve (AUC) >0.92 for predicting outcomes at 24 and 72 h from the time of initial presentation to the emergency room, and it provided 16% improvement in average AUC measured across all participating sites and an average increase in generalizability of 38% when compared with models trained at a single site using that site's data. For prediction of mechanical ventilation treatment or death at 24 h at the largest independent test site, EXAM achieved a sensitivity of 0.950 and specificity of 0.882. In this study, FL facilitated rapid data science collaboration without data exchange and generated a model that generalized across heterogeneous, unharmonized datasets for prediction of clinical outcomes in patients with COVID-19, setting the stage for the broader use of FL in healthcare.

Dissecting multi-photon resonances at the large hadron collider

We examine the phenomenology of the production, at the 13 TeV Large Hadron Collider (LHC), of a heavy resonance X, which decays via other new on-shell particles n into multi-(i.e. three or more) photon final states. In the limit that n has a much smaller mass than X, the multi-photon final state may dominantly appear as a two-photon final state because the γ s from the n decay are highly collinear and remain unresolved. We discuss how to discriminate this scenario from X → γ γ : rather than discarding non-isolated photons, it is better to relax the isolation criteria and instead form photon jets substructure variables. The spins of X and n leave their imprint upon the distribution of pseudo-rapidity gap Δ η between the apparent two-photon states. Depending on the total integrated luminosity, this can be used in many cases to claim discrimination between the possible spin choices of X and n, although the case where X and n are both scalar particles cannot be discriminated from the direct X → γ γ decay in this manner. Information on the mass of n can be gained by considering the mass of each photon jet.

Hypoxia Inducible Factor 1: A Urinary Biomarker of Kidney Disease

Identifying noninvasive biomarkers of kidney disease is valuable for diagnostic and therapeutic purposes. Hypoxia inducible factor 1 (HIF-1) expression is known to be elevated in the kidneys in several renal disease pathologies. We hypothesized that the urinary HIF-1a mRNA level may be a suitable biomarker for expression of this protein in chronic kidney disease (CKD). We compared HIF-1a mRNA levels from urine pellets of CKD and healthy subjects. To ensure that urinary HIF-1a mRNA is of kidney origin, we examined colocalization of HIF-1a mRNA with two kidney specific markers in urine cells. We found that HIF-1a mRNA is readily quantifiable in urine pellets and its expression was significantly higher in CKD patients compared with healthy adults. We also showed that the urinary HIF-1a mRNA comes primarily from cells of renal origin. Our data suggest that urinary HIF-1a mRNA is a potential biomarker in CKD and can be noninvasively assessed in patients.

An unusual cause of meningitis

A 57 year old man patient presented with fever and frontal headache. He had a background history of sero-positive rheumatoid arthritis which was well controlled on immunomodulatory disease modifying anti-rheumatoid drugs (DMARDS) including methotrexate and lef lunomide. Six months earlier he had returned from Massachussetts in the USA after a one year period of residence there. On examination his vital signs were within normal limits and he was afebrile with a temperature of 36.1oC. His left elbow joint was warm, tender and swollen; examination was otherwise normal.

Immediate coronary artery bypass surgery after platelet inhibition with eptifibatide: results from PURSUIT. Platelet Glycoprotein IIb/IIIa in Unstable Angina: Receptor Suppression Using Integrelin Therapy

BACKGROUND

The platelet GP IIb/IIIa inhibitor eptifibatide improves outcomes in patients with acute coronary syndromes. Patients requiring emergent coronary artery bypass grafting, however, may be at increased risk for bleeding if exposed to eptifibatide. Data from the PURSUIT trial were reviewed to assess this risk in patients undergoing coronary surgery immediately after exposure to eptifibatide.

METHODS

In PURSUIT, 10,948 patients who presented with non-ST segment elevation acute coronary syndromes were prospectively randomized to receive eptifibatide (180 microg/kg bolus plus 2 microg/kg/min infusion) or placebo. A total of 78 patients underwent immediate coronary artery bypass surgery within 2 hours of cessation of study drug (placebo, n = 46; eptifibatide, n = 32). Clinical outcome, bleeding, and transfusion requirements within this subset were examined.

RESULTS

Major bleeding was not different between groups, occurring in 64% of patients receiving placebo and 63% of patients receiving eptifibatide. The incidence of blood transfusion was similar as well (57% vs 59%). Postoperative thrombocytopenia occurred less often after eptifibatide exposure. Perioperative myocardial infarction was significantly reduced in patients who received eptifibatide (46% vs 22%, p < 0.05). There was no difference in perioperative stroke (2.2% vs 6.3%) or mortality (6.3% vs 6.5%).

CONCLUSIONS

Patients may safely undergo coronary artery bypass surgery within 2 hours of discontinuation of eptifibatide. Eptifibatide infusion in the immediate preoperative period had no adverse clinical effects, but did significantly decrease the incidence of perioperative myocardial infarction. Additionally, platelet counts after surgery were higher in the group of patients who received eptifibatide, perhaps indicative of a platelet-sparing effect during cardiopulmonary bypass.

Sternal instability after midline sternotomy

The purpose of this paper is to discuss sternal instability a problem occasionally associated with midline sternotomy, including the etiology, predisposing conditions, diagnosis and management. Among the methods of repair, sternal weaving and pectoralis muscle advancement are thought to be especially effective.

Preconception counseling and women's compliance with folic acid supplementation

QUESTION

I am counseling patients to take folic acid when they plan pregnancy and during early pregnancy. Is there any proof that counseling really causes women to comply?

ANSWER

A recent Motherisk study showed that counseling women who were planning pregnancy about folic acid use is very effective: 71% of those counseled took folic acid, compared with only 17% of those who were not counseled.

Inhibitors of the platelet receptor glycoprotein IIb-IIIa and complications during percutaneous coronary revascularization. Management strategies for the cardiac surgeon

Platelet-mediated thrombosis has a pivotal role in the pathophysiology of acute ischemic coronary syndromes (AICS) and the acute complications of percutaneous coronary interventions. Because cross-linking of the activated platelet receptor glycoprotein (GP) IIb-IIIa by plasma fibrinogen represents the final common pathway to coronary thrombus formation, several GP IIb-IIIa inhibitors have been developed as a potentially more effective antithrombotic therapy than agents currently used for this purpose, namely aspirin and heparin. However, use of GP IIb-IIIa inhibitors in patients with AICS and those scheduled for percutaneous coronary interventions may increase the risk of serious clinical and bleeding events among patients who require emergency or urgent bypass surgery. This review describes clinical experience with various GP IIb-IIIa inhibitors and suggests management strategies for patients undergoing emergency or urgent bypass surgery shortly after treatment with GP IIb-IIIa inhibitors.

Steroid-DNA conjugates: improved triplex formation with 5-amido-(7-deoxycholic acid)-dU incorporated oligonucleotides

The synthesis of oligodeoxyribonucleotides incorporating 7-deoxycholic acid conjugated at C5 of dU is described. When used as third strand, these form oligonucleotide triplexes with higher stability compared to unmodified controls at physiological pH.

Percutaneous bailout therapy of a perforated vein graft using a stent-autologous vein patch

A 74-yr-old man with two prior coronary bypass surgeries experienced perforation of an occluded aortocoronary vein graft during a transluminal extraction catheter (TEC) procedure for unstable angina. The perforation was successfully closed using a Palmaz 154 stent covered with a short segment of autologous antecubital vein.

Imaging in phaeohyphomycosis of the brain: case report

A case of multiple, conglomerated brain abscesses due to Xylohypha bantiana, with unique imaging features, is presented. This is the first culture-proven case of brain infection due to this fungus in the neuroimaging literature.

Laparoscopic cholecystectomy: the Dammam Central Hospital experience

Over a one year period (June 1992-June 1993), 260 patients (208 females and 52 males) with mean age of 37 years (range 13-80), underwent laparoscopic cholecystectomy (LC) for symptomatic gallstones. Thirty patients were admitted as emergency (20 acute cholecystitis, 10 acute pancreatitis). The procedure was performed successfully in 232 cases (89%). In 28 patients (18 electives, 10 emergencies), the procedure was converted to open for a variety of reasons, difficult anatomy being the commonest. Our mean operative time was 99.9 minutes (range 30-290 minutes). There were 3 major complications (2 common bile duct injuries and one abdominal aortic injury) and 4 minor complications (2 wound infections, one prolonged ileus and one chest infection). There was one death due to sickle cell crisis on the fifth post-operative day. The mean hospital stay was 2.3 days and 6.5 days for LC and converted cases, respectively. Our results suggest that laparoscopic cholecystectomy can be offered and conducted safely and effectively in the great majority of patients presenting acutely or electively with cholelithiasis, and that the results we achieved during the first year of our experience with LC is comparable to those reported from Europe and North America.

Long-term results of core decompression for ischaemic necrosis of the femoral head

We have studied the long-term results of core decompression as the sole treatment for Ficat stages I, II and III ischaemic necrosis of 128 femoral heads in 90 patients. The 5-, 10- and 15-year survival rates for the three stages were respectively: stage I 100%, 96% and 90%; stage II 85%, 74% and 66%; and stage III 58%, 35% and 23%. At a mean follow-up of 11 years (4.5 to 19), 55 hips had failed (43%). No further surgery had been needed for 88% of stage-I, 72% of stage-II and 26% of stage-III hips; but despite the generally satisfactory clinical results, 56% of the hips had progressed radiographically by at least one Ficat stage. Complications of the core procedure included four fractures, all from postoperative falls, and one head perforation due to technical error. We conclude that core decompression delays the need for total hip replacement in young patients with ischaemic necrosis.

Anatomical restraints to dislocation of the second metatarsophalangeal joint and assessment of a repair technique

The aim of this study was to determine the anatomical restraints to dislocation of the second metatarsophalangeal joint and to assess the biomechanical efficacy of a technique that is commonly used to stabilize this joint. Cadaveric feet were disarticulated at the ankle, with preservation of the long flexor tendons at the medial malleolus. The hindfoot was transfixed to an aluminum jig, and a contoured nylon block was secured to the dorsum of the second metatarsal. A Kirschner wire was passed transversely through the proximal phalanx and was attached to a wire loop through which a constant vertical displacement was applied with a universal testing machine. A preload of five newtons was applied, followed by a constant displacement of two millimeters per minute, and the load-displacement curves were measured. The volar plate and the collateral ligaments were divided in five feet each. In another ten feet, both of these structures were divided simultaneously. Each load cycle was repeated four times. The force required to dislocate the joint, in the position in which testing was performed, was reduced by a mean of 30 per cent when the volar plate was divided and by a mean of 46 per cent when the collateral ligaments were divided. Division of both of these structures created an unstable joint, which dislocated at an applied load of five to ten newtons. The metatarsophalangeal joint was then repaired with use of a flexor tendon transfer in all twenty feet. This repair technique restored the load-displacement curves to that of the normal toe.

Growth performance in anemia and following iron supplementation

The growth status of anemic (n = 117, Hb 7-10 g/dl) and normal (n = 53, H > or = 11 g/dl) children 3-5 years of age living under similar environmental and socio-economic conditions was evaluated. The dietary intake was assessed on a random subsample of the anemic and normal children. The anemic children had a poorer growth status than normal children as indicated by their significantly (p < 0.001) lower body weight, height and weight for age and significantly (p < 0.001) larger number in Grades II and III malnutrition. Iron supplementation (40 mg elemental iron/day) for six months produced a significant (p < 0.001) increase in Hb levels of both groups (1.6 g/dl in the anemic and 0.8 g/dl in the non-anemic) compared to their respective controls who received sugar placebos. The growth performance of the anemic children supplemented with iron was superior to that of anemic placebo treated children as indicated by a better weight gain and a significantly higher weight for height (p < 0.05). Weight for age was a good differentiator of the anemic from normal while weight for height was a good indicator of the impact of iron supplements on growth.

Factors affecting the strength of flexor tendon repair

The effects of different thicknesses and configurations of core sutures were studied in human cadaveric flexor tendon repairs. Both straight and cyclic load tests were employed. To exploit the full strength of 4/0 suture material, the Kessler repair using four locked single knots would seem to be appropriate.

Salicylate induced exacerbation of ulcerative colitis

The oral administration of mesalazine (5-aminosalicylic acid) resulted in the exacerbation of ulcerative colitis in two patients intolerant to sulphasalazine whose colitis had previously been quiescent. Although sulphasalazine intolerance is usually attributable to the sulphapyridine moiety, the possibility of salicylate sensitivity should be considered in colitic patients who fail to respond appropriately to sulphasalazine or who experience abdominal pain or diarrhoea while taking the drug.