An appraisal of a cell culture test for revealing the presence of E. coli thermolabile enterotoxin (L.T.).

Three methods were comparatively used for revealing the presence of thermolabile enterotoxin (L.T.) of E. coli strains causing diarrheal illness of children. From 228 patients 52 L.T.+ strains (22.8%) were identified with the classic rabbit skin test out of which 50 L.T.+ strains (21.9%) also reacted positively in a cell culture test using CHO-KI cells and only 33 L.T.+ strains (14.4%) in the rabbit intestinal loop test. The cell culture test appears to have a constant sensitivity, it is inexpensive, easy to perform and therefore adequate to be carried out in experienced field laboratories.

Evaluation of the anti-rubella immunity levels on a lot of 5,000 sera from women at procreative age, tested by HAI, in Romania.

From the study performed on a lot of 5030 sera, prelevated from women between 15-40 years old, tested by hemagglutination inhibition reaction (HAI), divided in 5 age groups of 5 years each, resulted that the percentage of women that can be considered immunologically protected against rubella (with HAI antibody titers greater than or equal to 1/20) varied between 79.5% (15-20 years of age group), and 75.3% (31-35 years of age group). The average percentage for the total lot was 76.7. The geometrical means (MGx/divided by SG) of the individual HAI titers ranged between extreme values of 54.2 (x/divided by 4.1) for the Group I, and 40.7 (x/divided by 3.8) for the Group IV, presenting the value of 44.4 (x/divided by 3.9) for the total lot. The covering coefficients of the protection limit, estimated at the level of geometrical means of antibody titers, ranged between 2.7 and 2.0, according to the age group, while the estimations made at the levels of the limits of the statistical range of one geometric standard deviation (MG x/divided by SG), presented values comprised between 11-8 and 0.7-0.5, respectively. On the basis of some theoretical mathematical models proposed in the literature (and using data resulted from the study performed), an attempt was made to approximate the rate of fetal exposure as well as the presumptive risk of congenital rubella syndrome (to 0/0000 live-born).

Some characteristics of the ICCe-1, a new simian embryo cell line.

A new simian embryo cell line has been established from a Cercopithecus male whole embryo. The resultant predominant fibroblast-like cell population has been frozen in convenient quantities and characterized for use in biological research as well as in theoretical and practical virological purposes. The cell line was designated ICCe-1 (Institute Cantacuzino Cercopithecus embryo-1).

[The incidence of E. coli O157H7 strains in causing hemorrhagic enterocolitis]. / Incidenta tulpinilor de E. coli O157H7 in producerea enterocolitelor hemoragice.

The authors describe the evidencing of the O157H7 E. coli serotype--an enterohaemorrhagic strain of E. coli--for the first time in our country. This germ is incriminated in haemorrhagic enteritis of children and adults, accompanied or not by an uremic haemolytic syndrome. A total of 717 strains were investigated, obtained from cases of haemorrhagic enteritis (283), nonhemorrhagic enteritis (174), food poisoning (27), and a control lot of subjects without signs of enteritis (233). Identification of the strains was done with a screening method (McConkey) with D-sorbitol in place of lactose, and with anti-O157, and anti-H7 sera. The results obtained have indicated a total of 37 positive strains in haemorrhagic enteritis (69.8%), 12 strains in nonhemorrhagic enteritis (22.65%), and 4 strains in food poisoning (7.55%). No strain was isolated from the control group. The percentage of isolated O157H7 E. coli strains in our county is of 7.55% and this contributes to additional knowledge in the definition of the still unknown etiology of diarrhoeic disease in our country.

[Production and characterization of some mouse embryo cellular substrates in vitro]. / Obtínerea si caracterizarea unor substrate celulare embrionare de Soarece in vitro

Cell cultures with a different multiplication potential in vitro, depending upon the strain source used, were obtained from mouse embryos belonging to the CVA, C57 Black A2G and Swiss strains. Only the Swiss 12 culture underwent spontaneous transformation and was carried through more than 50 passages in vitro. The Swiss-12 substrate proved not to be contaminated either by viruses or micoplasma. It is less sensitive than other elective cell substrates to infection with attenuated polioviruses, cytopathogenic Coxsackie A9 virus and vaccinia virus, but its sensitivity to infection with Herpes simplex type 1 virus is similar to that of human embryo fibroblasts. After a high number of passages the Swiss-12 substrate permits, in comparison to other cell substrates (human heteroploid Hep-2 line, human embryo fibroblasts), a highly efficient qualitative differentiation between the growth media and calf serum.