Staphylococcus aureus is a major human pathogen that causes a wide range of clinical infections. It is a leading cause of bacteremia and infective endocarditis as well as osteoarticular, skin and soft tissue, pleuropulmonary, and device-related infections. This review comprehensively covers the epidemiology, pathophysiology, clinical manifestations, and management of each of these clinical entities. The past 2 decades have witnessed two clear shifts in the epidemiology of S. aureus infections: first, a growing number of health care-associated infections, particularly seen in infective endocarditis and prosthetic device infections, and second, an epidemic of community-associated skin and soft tissue infections driven by strains with certain virulence factors and resistance to β-lactam antibiotics. In reviewing the literature to support management strategies for these clinical manifestations, we also highlight the paucity of high-quality evidence for many key clinical questions.

Staphylococcus aureus Infections: Epidemiology, Pathophysiology, Clinical Manifestations, and Management

SINCE Cohen's review of amyloidosis was published in the Journal in 1967, there have been major advances in our understanding of what was less than a decade ago an untreatable, usually lethal disease complex of unknown nature, cause, and pathogenesis. Much of the mystery about the character of the "waxy, eosinophilic" tissue deposits, which Virchow believed in 1853 to be of polysaccharide composition and consequently designated as "amyloid" (starch-like or cellulose-like) has now yielded to investigations employing a wide variety of chemical and physical techniques. Once it was demonstrated that unique fibrillar components comprised over 90 per cent of amyloid . . .

Amyloid deposits and amyloidosis. The beta-fibrilloses (first of two parts).

https://www.thelancet.com/pdfs/journals/lancet/PIIS0140-6736(00)02530-7.pdf

Etanercept in the treatment of psoriatic arthritis and psoriasis: a randomised trial

Objective
Etanercept has been shown to improve the articular and cutaneous manifestations of psoriatic arthritis (PsA). In this study, we further evaluated the safety, efficacy, and effect on radiographic progression of etanercept in patients with PsA.

Methods
Patients with PsA (n = 205) were randomized to receive placebo or 25 mg etanercept subcutaneously twice weekly for 24 weeks. Patients continued to receive blind-labeled therapy in a maintenance phase until all had completed the 24-week phase, then could receive open-label etanercept in a 48-week extension. Efficacy and safety were evaluated at 4, 12, and 24 weeks and at 12-week intervals thereafter. Radiographs of the hands and wrists were assessed at baseline and 24 weeks, at entry to the open-label phase, and after 48 weeks in the study.

Results
Etanercept significantly reduced the signs and symptoms of PsA and psoriasis. At 12 weeks, 59% of etanercept patients met the American College of Rheumatology 20% improvement criteria for joint response, compared with 15% of placebo patients (P < 0.0001), and results were sustained at 24 and 48 weeks. At 24 weeks, 23% of etanercept patients eligible for psoriasis evaluation achieved at least 75% improvement in the Psoriasis Area and Severity Index, compared with 3% of placebo patients (P = 0.001). Radiographic disease progression was inhibited in the etanercept group at 12 months; the mean annualized rate of change in the modified total Sharp score was −0.03 unit, compared with +1.00 unit in the placebo group (P = 0.0001). Etanercept was well tolerated.

Conclusion
Etanercept reduced joint symptoms, improved psoriatic lesions, inhibited radiographic progression, and was well tolerated in patients with PsA.

https://onlinelibrary.wiley.com/doi/pdf/10.1002/art.20335

Etanercept treatment of psoriatic arthritis: safety, efficacy, and effect on disease progression

Background Although corticosteroids are highly effective in improving symptoms of Crohn's disease, they may have substantial toxicity. In some patients, attempts to discontinue corticosteroids are ...

https://www.nejm.org/doi/pdf/10.1056/NEJM199502023320503

Methotrexate for the Treatment of Crohn's Disease

Thirty-seven patients with psoriatic arthritis were entered into a 12-week prospective, controlled, double-blind multicenter trial comparing placebo and oral pulse methotrexate therapy. Methotrexate was given in a dose of 2.5-5.0 mg every 12 hours in 3 consecutive doses per week. A stable background medication program with nonsteroidal antiinflammatory drugs was allowed. Methotrexate was superior to placebo only in physician assessment of arthritis activity and in improvement of the amount of skin surface area with psoriasis. A small but statistically significant rise of serum total bilirubin occurred in the methotrexate-treated patients. No patients were withdrawn from the study for adverse drug effects.

https://onlinelibrary.wiley.com/doi/pdf/10.1002/art.1780270403

Randomized, Double‐Blind, Placebo Controlled Trial of Low‐Dose Pulse Methotrexate in Psoriatic Arthritis

Surgery and needle aspiraton have been evaluated as initial modes of drainage in 59 patients with acute septic arthritis. Full recovery was noted in 42% treated surgically at the outset. On the other hand, 67% of those treated by needle aspiration recovered without sequelae, despite the greater prevalence in this group of adverse host factor-eg, serious underlying illness, concommitant extraarticular infection, prior arthritis in the infected joint, and recent antibiotic or immunosuppressive therapy.

https://onlinelibrary.wiley.com/doi/pdf/10.1002/art.1780180116

Treatment of septic arthritis

B cell and T cell lymphopenia in systemic lupus erythematosus

Neuropathy, m components, and amyloid

To date, all human amylodotic spleens studied by us have yielded a protein which is not detectable in normal or non-amyloidotic tissue. This protein has been identified by immunoelectrophoresis in the blood of normal individuals and for this reason has been called the P (plasma)—component of amyloid(1,2). We have recently measured the plasma level of P-component in patients with amyloidosis in order to determine whether its presence has any diagnostic significance and whether any data relevant to the genesis of amyloid might be obtained. Sera from patients with rheumatoid arthritis were studied as “pathologic” controls and also because this condition is not infrequently complicated by amyloidosis.Materials and Methods. A total of 35 pathologic sera were tested; 21 were derived from patients with biopsy proven amyloidosis, the remaining 14 from patients with classical rheumatoid arthritis. As controls, sera from 25 young and presumably healthy blood donors and cord blood from 9 new-born infants were tested...

Edgar S. Cathcart

Papers

Randomized, Double‐Blind, Placebo Controlled Trial of Low‐Dose Pulse Methotrexate in Psoriatic Arthritis

Treatment of septic arthritis

B cell and T cell lymphopenia in systemic lupus erythematosus

Neuropathy, m components, and amyloid

Immunoassay of P-component in amyloidotic sera.