Self-reports of health care utilization compared to provider records.

This study compares self-reports of medical utilization with provider records. As part of a chronic disease self-management intervention study, patients completed self-reports of their last six months of health care utilization. A subgroup of patients was selected from the larger study and their self-reports of utilization were compared to computerized utilization records. Consistent with earlier studies, patients tended to report less physician utilization than was recorded in the computerized provider records. However, they also tended to report slightly more emergency room visits than were reported in the computerized utilization records. There was no association between demographic or health variables and the tendency toward discrepancy between self-report and computerized utilization record reports. However, there was a tendency for the discrepancy to increase as the amount of record utilization increased. Thus, the likelihood of bias caused by differing demographic factors is low, but researchers should take into account that underreporting occurs and is likely to increase as utilization increases.

Effects of structure on alpha C-H bond enthalpies of amino acid residues: relevance to H transfers in enzyme mechanisms and in protein oxidation.

The bond dissociation enthalpies (BDE) of all of the amino acid residues, modeled by HC(O)NHCH(R)C(O)NH(2) (PH(res)), were determined at the B3LYP/6-31G//B3LYP/6-31G level, coupled with isodesmic reactions. The results for neutral side chains with phi, psi angles approximately 180 degrees, approximately 180 degrees in ascending order, to an expected accuracy of +/-10 kJ mol(-)(1), are Asn 326; cystine 330; Asp 332; Gln 334; Trp 337; Arg 340; Lys 340; Met 343; His 344; Phe 344; Tyr 344; Leu 344; Ala 345; Cys 346; Ser 349; Gly 350; Ile 351; Val 352; Glu 354; Thr 357; Pro-cis 358; Pro-trans 369. BDEs calculated at the ROMP2/6-31G//B3LYP/6-31G level exhibit the same trends but are approximately 7 kJ mol(-)(1) higher. All BDEs are smaller than those of typical secondary or tertiary C-H bonds due to the phenomenon of captodative stabilization. The stabilization is reduced by changes in the phi,psi angles. As a result the BDEs increase by about 10 kJ mol(-)(1) in beta-sheet and 40 kJ mol(-)(1) in alpha-helical environments, respectively. In effect the alpha C-H BDEs can be "tuned" from about 345 to 400 kJ mol(-)(1) by adjusting the local environment. Some very significant effects of this are seen in the current literature on H-transfer processes in enzyme mechanisms and in oxidative damage to proteins. These observations are discussed in terms of the findings of the present study.

Prevalence and expression of photosensitivity in systemic lupus erythematosus.

Photosensitivity was assessed in 125 patients with systemic lupus erythematosus (SLE) and in 281 patients with rheumatoid arthritis (RA) as controls. Photosensitivity was reported by 87/119 (73%) patients with SLE and in 62/269 (23%) patients with RA; involving the face in 72/122 (59%) patients with SLE, then arms, chest, and neck. Patients with SLE reported that sun exposure could exacerbate various systemic symptoms, 51/121 (42%) reported medical treatment for photosensitivity and 41/118 (35%) reported that photosensitivity had a significant impact on their lifestyle. There was no significant difference in disease severity, as judged by physician or laboratory results, between patients scoring high or low on the photosensitivity scale.