[The software design for the molecular biological image processing system].

With the use of Visual Basic 6.0 language and molecular biological technology, we have developed a new molecular biological information processing system to detect the characteristic parameter of molecular biological electrophoresis image. The software can determine the molecular weight of the restriction endonuclease hydrolytic DNA fragment and protein or other macromolecules. The application indicates that the system with its accuracy reliability high efficiency and a large capacity of data to be stored, It is very useful to gene diagnosis and molecular biological researches.

[The molecular basis of HLA DR4 alleles associated with rheumatoid arthritis in a Chinese population].

HLA-DR4 gene was studied by polymerase chain reaction method in 95 patients with rheumatoid arthritis(RA) and 130 normal controls in a Shanghai population. The results showed that the DR4 was significantly associated with RA(RR = 3.1, chi 2 = 13.8, P < 0.005). The second exon of DR4 gene was also analysed by PCR-RFLP technique. There were at lest eight DR4 subtypes in this Chinese population. The DRB1 *0405 (Dw15) was the most common allele, accounting for 48% of DR4 positive normal individuals and also is a principal subtype associated with RA susceptibility (RR = 3.1, P < 0.005). Analysis of the third hyperpolymorphic region of DR4 positive samples showed that 92% of patients had a sequence encoding amino acids RRAA or KRAA compared with 56% of the DR4 positive controls (chi 2 = 10.29 P < 0.005). All subtypes that were positively associated with RA susceptibility had the RRAA (DRB1* 0404, 0405. 0408 and 0410) or KRAA (DRB1 * 0401) sequences, while the negatively associated ones (DRB1 0402, 0403 and 0406) had not. As a further evidence, it strongly supported the "shared epitope" hypothesis. The different DR4 subtype structures and frequencies may account for the different associations of DR4 with RA in various ethnic groups.

Factors associated with the decline of the Cooperative Medical System and barefoot doctors in rural China.

The Cooperative Medical System (CMS) and its barefoot doctors have been in decline in rural China for nearly a decade. In order to explore the reasons for this, in 1987 we carried out a survey of villagers, barefoot doctors, and local administrators in Fengxian, Shanggoa, and Loaan counties, where incomes are good, fair, and low, respectively. The state of the CMS in these counties was contrasted and the situations which prevailed in 1978, 1982, and 1985, when the system was, respectively, at its peak, had begun to decline, and had declined markedly, were compared. A random sample of villages was selected and all the barefoot doctors and administrators as well as a random sample of households were surveyed. The results indicate that health status (as measured by infant mortality, immunization coverage, and rate of infectious diseases) has decreased in areas where the CMS has declined, while per capita incomes increased. Concomitantly, villager's expenditures on health care have increased. Barefoot doctors and their patients were, however, reasonably happy with the system, and in its absence the doctors are no longer able to obtain ongoing training. The CMS was fiscally sound, and did not decline to the same extent in all areas--it continues to thrive in Fengxian, which is relatively affluent. It is concluded that the system probably declined because many local administrators perceived that it no longer enjoyed the backing of the central government.