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Fifty-five patients with primary gastric non-Hodgkin's lymphoma were treated in our hospital from 1970 to 1986. The overall 5-year survival rate was 70.5%. For patients with Stages IE and IIE, the 5-year survival rates were 90.5% and 57.1%, respectively. No significant relation to survival was observed concerning sex, age and course of disease. The important prognostic factors of primary gastric non-Hodgkin's lymphoma were: stage, histologic type, depth of invasion and mode of management. Postoperative radiation therapy with or without chemotherapy was better than surgery alone. Total 60Co abdominal irradiation by moving strip technique was better than multifield irradiation. While no evidence was in favor of post-operative radiotherapy plus chemotherapy for stage IE and IIE lesions, multi-disciplinary approach should be considered for patients at high risk of recurrence and metastasis.

The surveillance of sensitivity of P. falciparum to pyronaridine/sulfadoxine/pyrimethamine has been carried out in Diaoluo area in Hainan Province where chloroquine-resistant falciparum malaria is endemic, covering an area of 406 square kilometers, with a population of 3745 in 1986. From 1986 all outpatients diagnosed as falciparum malaria were administered with PND/S/P as the only antimalarial. In vivo sensitivity of P. falciparum was measured in some patients who were treated in hospital. It was demonstrated that P. falciparum in the Diaoluo area has retained its sensitivity to a single oral dose of PND/S/P of 500/1,000/50 mg with 100% cure rate for at least 5 years.

Pyronaridine, a highly effective antimalarial drug, was synthesized and developed by this institute. In order to test whether the joint blood schizontocidal action of pyronaridine (PND) and 2:1 mixture of sulfadoxine/pyrimethamine (SP) resulted in a potentiation or an additive effect, groups of P berghei ANKA strain-infected mice were treated with various single oral doses of PND and SP. Thin blood smears were made after 72 h and the parasitemia-negative rates were calculated. The ED50 values obtained were plotted in isobolograms. An additive action of this triple combination was demonstrated. Mice were inoculated with P berghei ANKA strain-infected erythrocytes 3 and 2 d after the mice were given a single oral dose of PND 10 mg/kg alone, or combined with SP 3 mg/kg. Thin blood smears made on d 3, 5, 8 and 10 revealed that the parasitemia-positive rates and the duration of residual blood schizontocidal action of PND used alone was similar to that of PND used in combination (P greater than 0.05). Three groups of mice carrying P berghei ANKA strain gametocytes were administered orally with pyrimethamine 0.1 mg/kg, SP 0.3 mg/kg and SP 0.3 mg/kg plus PND 0.5 mg/kg, respectively. Anopheles stephensi were then fed on the mice 2 h after the medication. There resulted no significant differences of gametocytocidal and sporontocidal effects among the 3 groups, since the oocyst-positive rate and the glandpositive rate were similar in these groups.

Sequence analysis of the human retinoblastoma gene cDNA revealed the presence of repeated elements in the form of direct repeats, inverted repeats and dyad symmetries. The clustering of the dyad symmetrical elements in some exons, #16 and #17, coincides with the hot spots for structural aberrations of the RB-1 locus previously observed in tumors. The RB-1 gene is divided into at least 27 exons distributed over 200 kbp. Three potential Sp1 binding sites are presented within 600 bp upstream of the translation start site. A DNA fragment containing these Sp1 sites ligated to a promotorless CAT gene can promote its transcription in transfected cell culture.

The triple combination of pyronaridine, sulfadoxine and pyrimethamine which has been proven to be efficient in delaying emergence of drug resistance of rodent malarial parasites was further studied for potential application to malaria control. The antimalarial effect of the triple combination on Plasmodium berghei ANKA-infected mice and the toxic effects in mice and rats were additive. A single dose of pyronaridine 500 mg in combination with sulfadoxine, 1000 or 1500 mg, and pyrimethamine, 50 or 75 mg, given to 72 acute falciparum malaria patients resulted in a 100% cure rate with nil or mild side effects, and no recrudescence of asexual parasite over 4-week follow-up. Preliminary experiments on the drug effect on sporogony showed that the drug combination at the dose used could not completely interrupt the sporozoite formation although many retarded oocysts were found.