Computer-assisted imaging cytometry of nuclear chromatin reveals bone tumor virus infection and neoplastic transformation of adherent osteoblast-like cells

Established osteoblast-like (OB) cells infected with the bone tumor-inducing C-type retrovirus OA MuLV remained nontumorigenic over 104 cell culture passages. DNA histograms revealed a new cell population with a stem line peak at 5c. A second OA MuLV-infected OB cell line underwent neoplastic transformation with increasing passage level. These cells showed diffuse aneuploidy. Stepwise linear discriminant analysis of the chromatin structure of control, OA MuLV-infected, and FBR osteosarcoma virus-transformed cell lines resulted in various levels of discrimination ranging between 79.6% for control cells versus nontumorigenic OA MuLV-infected cells, and 96.6% for nontumorigenic OA MuLV-infected cells versus FBR osteosarcoma virus-transformed cells. OA MuLV-infected tumorigenic cells and FBR osteosarcoma virus-transformed cells were discriminated at a 93.6% level.     

Interaction of a cellular 57-kilodalton protein with the internal translation initiation site of foot-and-mouth disease virus.

A cellular 57-kDa protein (p57) that binds specifically to the internal translation initiation site in the 5' untranslated region of foot-and-mouth disease virus RNA was detected in cell extracts of different mammalian species by UV cross-linking. The protein binds to two distinct sites of the translation control region which have as the only common sequence a UUUC motif. The first binding site consists of a conserved hairpin structure, whereas the second binding site contains an essential pyrimidine-rich region without obvious secondary structure. Competition experiments indicate that the complexes with the two binding sites were formed by a single p57 species. The protein binds also to the 5' untranslated region of other picornaviruses. Results from footprint analyses with foot-and-mouth disease RNA suggest the participation of additional cellular factors in the translation initiation complex.     

Sulfated glycosaminoglycans synthesized by human smooth muscle cells isolated from different organs

The sulfated glycosaminoglycans synthesized by human smooth muscle cells isolated from different organs were identified on the basis of electrophoretic mobility, enzymatic degradation with specific mucopolysaccharidases and by the type of degradation products formed. The results obtained indicated that chondroitin sulfate and heparan sulfate were the main glycosaminoglycans found, that most of the labeled glycosaminoglycans were found in the pericellular pool, and that no marked differences were observed in the sulfated glycosaminoglycan composition of the smooth muscle cells obtained from different organs. 'Liver connective tissue cells', isolated from pathological livers (which had been shown to possess biochemical and physiological features typical of smooth muscle cells) showed a pattern of glycosaminoglycan synthesis similar to that of the smooth muscle cells.     

Clinical importance of circulating immune complexes in human acute lymphoblastic leukemia

Summary A total of 122 sera from acute lymphoblastic leukemia (ALL) patients were analyzed for circulating immune complexes (CIC) by two methods: the ¹²⁵I-C₁q binding assay and the polyethylene glycol precipitation test (PEG). The results were correlated with induction, remission and relapse stages of the disease. Using the first method the levels of CIC in induction were 15.18±9.15, with 19/29 positive cases (65.50%), P<0.001 compared with controls. In the remission phase the levels were 9.02±5.62, 11/45 (24.49%) nonsignificant P value, and in relapse they were 16.14±11.17 28/48 (58.33%) P<0.001. The PEG precipitation test results were: 0.33±0.10, 8/22 (36.36%); 0.24±0.11, 10/48 (20.83%) and 0.28±0.10, 6/28 (21.42%), respectively. Thus the values of CIC as measured by PEG in the three clinical of phases ALL did not differ significantly from controls. This contrasts with results obtained by the radioiodinated C₁q binding assay, where the incidence of positive values was significantly higher in induction and in relapse and lower in the remission phase. These observations were extended in sequential vertical studies performed in a group of patients. These results suggest that raised CIC detected by the ¹²⁵I-C₁q method may reflect a progressive state in ALL and that quantitation of these immune complexes may provide an adequate biochemical marker for prognosis.     

A comparison of the body height of the Israeli-born and immigrants to Israel

This paper reports a study of body height in the adult Jewish population of Israel, comparing native-born with immigrant groups. The sample tested included 1,411 men and 961 women, all clinically healthy according to the results of multiphasic screening. The phenomenon observed in other immigration-absorbing countries also holds for Israel: native Israelis are significantly taller than their immigrant counterparts. The findings were verified over different age and working activity strata, and thus may be taken to reflect the influence of better socioeconomic and environmental conditions on the bodily development of those born in Israel.     

Biological basis for the management of ‘lugs negra’ (Sarcothalia crispata Gigartinales,Rhodophyta) in southern Chile

The present paper describes growth dynamics in a natural bed of the resource luga negra (Sarcothalia crispata) in Guapilinao, southern Chile (41°57 S, 73°31 W). This resource is currently harvested and exported as raw material for the production of carrageenan. Seasonal variation in biomass, frond size, density and phenology was determined by periodic sampling. Natural recruitment was evaluated on different substrata added to the field; at the same time, substrata were inoculated under greenhouse conditions. Results showed that luga negra has seasonal growth: biomass increased from a minimum in spring to a maximum in mid to late summer. On the other hand, density was minimal in winter (200 ind. m^–2) and increased to 2000 ind. m^–2 in late spring. Peak abundance of mature tetrasporic fronds occurred in late summer, whereas that of cystocarpic fronds occurred in winter. Recruitment began in summer and extended into winter. Survival on different substrata were compared. Gametophytes had better survival rates on clam shells and 5 mm rope while tetrasporophytes had the best survival rate on clam shells and secondarily on boulders.