Given an abstract, generate a keyword (a noun phrase) that best describes the focus or contribution of the paper. Such keywords can be directly from the given abstract or outside it.

[Q]: Abstract: Although osteoarthritis (OA) generally is considered a disorder of mechanical origin, the common occurrence of chronic mononuclear cell infiltrates in the synovium in conjunction with immunofluorescent evidence for immune-reactant products in cartilage of surgical case specimens (knees, hips, and peripheral joints) has suggested the local involvement of immune processes in the arthritis. Further, the findings of polyarthropathy in the majority of these cases have indicated the propensity for a systemic disorder. Wide variations were noted in both synovial and cartilage immune changes, quite different to those found in rheumatoid arthritis, along with the frequent asymptomatology of the many joints involved. These features, with and without other causative factors, suggest that immune reactions of local and/or systemic origin occur at times in a population at risk for joint degradation.
[A]: Cartilage, Articular

[Q]: Abstract: Cardiac output was measured 120 times in 27 critically ill patients using the thermodilution and transthoracic electrical impedance methods. Both the minimum and mean values for the distance between the inner electrodes, and a variety of values for the resistivity of blood (rho) were substituted in the Kubicek's empiric formula for calculating cardiac output by transthoracic electrical impedance. Using the mean distance between the inner electrodes and a rho-value of 150 ohm X cm gave the best agreement between the methods (mean difference 0.17 +/- 2.4 L/min). Ventilation alone or with positive end-expiratory pressure did not significantly affect the bias of the estimate, but both affected its precision when compared with measurements in spontaneously breathing patients (SD of mean difference 2.4 and 3.2 L/min, respectively, vs. 1.5 L/min). The pulmonary artery wedge pressure was significantly higher in patients with an abnormal diastolic impedance waveform (zero-wave), but there was no relationship between wedge pressure and base impedance per unit length between the measuring electrodes.
[A]: Adult

[Q]: Abstract: A previously healthy 3-year-old boy was referred because of persistent fever and anterior neck swelling and pain. The diagnosis of a mixed bacterial abscess of the thyroid gland was made. Incision and drainage were performed, and fever abated immediately. Antibiotic therapy was given in the hospital and for ten days after discharge. Acute suppurative thyroiditis is a rarely encountered infection. The majority of cases reported in the recent literature are from Japan. The case presented here, from the United States, demonstrates the difficulty that can be encountered in diagnosing this type of thyroiditis.
[A]:
Case Report