[A comprehensive program in the fight against chronic non-infectious diseases in a basic population group--the Belec Study. IV. The interventional model]. / Cjeloviti program borbe protiv kronicnih nezaraznih bolesti u osnovnim populacijskim skupinama--studija Belec. IV. model intervencije.

As part of a comprehensive programme aimed at the struggle against chronic non-infectious diseases in basic population groups, an intervention model in the rural community Belec has been set up. The development, application and evaluation of this intervention model with an emphasis on positive experiences and difficulties connected with such a model have been described. The role of important parts of the programme has been emphasized--the work of the Health Committee and Guidance Clinic of Elevated Blood Pressure. The results show that there is necessary and possible to efficaciously involve the population of the community into the priority assessment, planning, application and follow-up of such a programme. However, the close cooperation with the local health service and other community sectors and their support is indispensible. It is also stressed that the economic and social development of the rural community is the prerequisite for the continuous intervention measures to be carried out and health care system promoted.

A study of rheumatoid factors in juvenile rheumatoid arthritis (chronic polyarthritis) by the photometric latex test.

The photometric latex test (PLT) for the detection of rheumatoid factors (RF), developed and clinically evaluated in adult rheumatoid arthritis, was applied in a study of juvenile rheumatoid arthritis (JRA). A total of 40 individuals with JRA, 27 with other collagen diseases and 24 in a control group were examined. The incidence of seropositives by PLT was 50% in JRA, 33% in collagen diseases and 17% in controls. The percentage of JRA was significantly higher than in the controls, and also higher than values in the literature claiming that only about 20% of JRA patients are seropositive. These findings were discussed concerning the diagnostic capability of PLT as compared with other serologic tests for RF. The increase in PLT titer values was found to indicate an aggravation of the inflammatory process and could help estimate the clinical stage of the disease. A follow-up of patient titer values could be of great diagnostic value. The data on serum immunoglobulins and complement fractions levels could not confirm the findings on a significant increase in JRA patients, but following of "level profiles" of each patient could add to the estimation of patient's clinical status. In cases of seropositives when other laboratory parameters did not indicate a clear transition from the chronic active to acute stage of disease, the only parameter which often showed such a transition is the RF titer determined by PLT testing, which could be of importance for a timely change of the therapy.

The photometric latex test for rheumatoid factors in patients with rheumatoid arthritis. II. Clinical evaluation.

The photometric latex test (PLT) for the detection of rheumatoid factors has been clinically evaluated. PLT titers have been closely studied in relation to clinical and laboratory parameters by means of parametric and nonparametric statistical methods. An analysis of the sensitized sheep cell test (SSC) titers has also been undertaken. The subjects comprised 377 patients with rheumatoid arthritis (RA) and 120 controls. The medical data recorded included sex, age, diagnosis, anatomical stage, functional class, duration and course of the disease, presence of the American Rheumatism Association (ARA) criteria, blood sedimentation rate, red and white blood counts, haemoglobin concentration, total protein content, serum protein levels, and SSC and PLT titers. A multivariate stepwise regression analysis with eight normally distributed variables was made. In accordance with previous findings, a significant correlation was shown to exist between the serum protein levels and the development of the RA when the anatomical stage, functional class and course of the disease were used as parameters of disease activity. In the RA patients there was also correlation between the serologic titers and the serum protein levels, and the anatomical stage, functional class and course of the disease, and the sedimentation rate, thus showing that titers can also serve as a measure of the inflammatory process. There was a significant correlation between the number of ARA criteria and the titers in the RA patients but not in the controls. The course of the disease correlated with the serum titers and other inflammatory parameters, a finding showing that the course of the disease is an important diagnostic parameter with possible prognostic value. Correlation was also demonstrated between the white blood count and the titers. It is concluded that the sedimentation rate, albumin and gamma-globulin levels, and PLT titer are the best parameters of disease activity. The titer values are not only of diagnostic importance but have prognostic value as regards the severity of the disease.

The photometric latex test for rheumatoid factors in patients with rheumatoid arthritis. I. correlation with other serologic tests.

The photometric latex test (PLT) for the detection of rheumatoid factors (RF) has been correlated with the sensitized sheep cell test (SSC) and the latex slide test (LST). A total of 377 sera from patients with rheumatoid arthritis (RA) and 120 sera from control subjects were examined. When the PLT was carried out on the native sera at a lower buffer ionic strength (0.05 M), agglutination was noted in over 99% of cases, indicating interaction of complement with human immunoglobulin bound to the latex particle surface. Although thermal inactivation eliminated most of the complement agglutination, an increase in ionic strength (0.5 M) was found to be essential for measuring only RF agglutination. The serologic data were analysed statistically by computer. A highly significant correlation was found between all serologic tests and RA sera, but there was no such correlation with the control sera. The specificity of all tests was generally over 90% and did not vary significantly, but the sensitivity varied from 52.0% to 71.1%, confirming that about one-third of all RA patients are seronegative. The tests were analysed for their total diagnostic capability. The PLT with native sera at higher ionic strenght proved to be the most sensitive, but with thermally inactivated sera it had a better diagnostic capacity. The SSC test appeared to be less sensitive and of lower diagnostic validity. Rapid LST tests were clearly inferior to PLT tests. The PLT can be used as a reliable and straightforward serologic method of diagnosis in RA, especially when carried out at a higher ionic strength and with thermally inactivated sera. It should be given preference over other serologic tests for RF and could well become standard practice in rheumatologic serology as a substitute for the SSC test.