Epidemiological and clinical aspects relating to the variability of rheumatoid arthritis

OBJECTIVE: To review epidemiological studies dealing with the temporal and geographic variability in the occurrence of rheumatoid arthritis (RA) and clinical studies that address the variability of severity and manifestations among populations. METHODS: An extensive search of the literature, including a Medline search, was completed. Studies addressing the origin, history, and trends in the occurrence of RA were reviewed first. Next, studies of the prevalence and incidence of RA in different populations were reviewed, and occurrence rates compared. Standardization was attempted by tabulating adult prevalence rates of studies using equivalent sets of criteria. Studies comparing RA patients from two populations were sought next. Finally, studies dealing with explanations of the presumed variability were reviewed. RESULTS: Temporal variability is indicated by paleopathological evidence that RA has existed in the New World since 4000 BC, whereas there is no evidence that it occurred in Europe before the 17th century, or in Africa before the 20th century. Epidemiological studies show a possible trend of decreasing incidence of RA in the United States and Western Europe, whereas reports from Africa note a rising incidence. In white populations of Europe and America, prevalence is approximately 1%, and incidence is 0.03%. Significantly higher rates are found in some North American Indians, and significantly lower rates in some Asian and African populations, even when the different population structures are taken into account. In the latter populations, different patterns of occurrence from those observed in whites emerge, such as greater female preponderance and a much younger peak age at onset. Direct standardized comparisons of two diverse populations of RA patients showed some differences in expression, severity, or manifestations of RA between populations. CONCLUSION: The occurrence and manifestations of RA are temporally and geographically variable.     

Pertussis in Massachusetts, 1981-1991: incidence, serologic diagnosis, and vaccine effectiveness

Massachusetts provides diphtheria-tetanus toxoid-pertussis (DTP) vaccine, and since 1980 has monitored pertussis with a statewide diagnostic service. The incidence of bacteriologically confirmed pertussis was 104.5 per 100,000 person-years in 1-month-old infants and declined progressively thereafter. Infants < 6 months old experienced disproportionate morbidity: 44% of bacteriologically confirmed pertussis, 64% of hospitalizations, and 71% of hospital days. Most children with pertussis had received < 3 DTP doses during childhood, whereas 87% of adolescents with pertussis had received > or = 4 doses. Serodiagnosis by single serum anti-pertussis toxin antibody ELISA increased the incidence of confirmed pertussis in persons 11-19 years old from 3.0 to 12.9 per 100,000 and in persons > or = 20 years old from 0.16 to 0.56 per 100,000. Bacteriologic methods underestimate pertussis incidence, but a single serum anti-pertussis toxin antibody ELISA is a practical method for population-based diagnosis in adolescents and adults.     

Running programs backwards: The logical inversion of imperative computation

Imperative programs can be inverted directly from their forward-directed program code with the use of logical inference. The relational semantics of imperative computations treats programs as logical relations over the observable state of the environment, which is taken to be the state of the variables in memory. Program relations denote both forward and backward computations, and the direction of the computation depends upon the instantiation pattern of arguments in the relation. This view of inversion has practical applications when the relational semantics is treated as a logic program. Depending on the logic programming inference scheme used, execution of this relational program can compute the inverse of the imperative program. A number of nontrivial imperative computations can be inverted with minimal logic programming tools.     

Prognostic significance of cathepsin-D in patients with breast cancer

The expression of the protease cathepsin-D has been evaluated using an immunohistochemical technique with a polyclonal antibody in paraffin-embedded tissue from 359 patients treated between the years 1975-1981 for Stage I and II breast cancer. One hundred and twenty seven patients (35%) have strongly positive, granular staining, 138 (38%) are intermediately stained in the cytoplasm, and in 94 (26%) no staining is observed. There is a strong positive association between expression of cathepsin-D and the presence of tumour in axillary lymph nodes (P < 0.006). Expression of the protease is associated with significantly poorer survival of patients in univariate analysis (P = 0.025); however, this is not independent of other tumour variables.     

An introduction to urinary incontinence

Urinary incontinence is most frequently associated with the elderly, particularly women, and is often thought of as inevitable. However, orthopaedic nurses encounter incontinence as a response to alterations in orthopaedic health. This article reviews the types of urinary incontinence, with emphasis on those which may most directly result from orthopaedic problems. It will also help the nurse differentiate between types of incontinence in a way that will clarify appropriate interventions.