A simple method for fusing human lymphocytes with rodent cells in monolayer by polyethylene glycol

Human lymphocytes were efficiently hybridized with three rodent cell lines growing attached to a substrate, by a procedure similar to the monolayer fusion technique. Lymphocytes in suspension were directly added to the monolayer and cocultured for a few hours. Treatment with polyethylene glycol (PEG) induced close contact between the two cell types, and extensive cell fusion occurred. The rate of hybridization differed markedly for the different cell lines used.

An ergo-ophthalmological battery of tests to classify truck drivers

16 healthy and ophthalmologically normal truck drivers are tested with a battery of tests according to the routine described in the following paper. This includes isopter perimetry, colour discrimination, recovery of sensitivity during dark adaptation and refraction at both far and near points, in order to record night myopia as well as night presbyopia. The ranges of individual variability are reported. As far as refraction is concerned, it seems of interest to stress the individual differences in a sort of "transient anisometropia" under incoming twilight.

A balanced translocation t(4;9) (q35;q12) with a breakpoint within the heterochromatic region of chromosome 9 in a woman with recurrent abortion

A case of recurrent abortion was found to be associated with the presence in the mother of a balanced translocation between chromosomes 4 and 9. The karyotypes of the proposita was: 46,XX,t(4;9)(q35;q12). The effects of this translocation are discussed in the light of other cases reported in the literature.

Properties and significance of a small marker chromosome in amniotic fluid cells

We report the presence of a small supernumerary metacentric chromosome in an amniotic fluid cell culture. The extra chromosome was inherited from the mosaic mother, and was characterized by the presence of four satellite regions, two on each side of the centromere. The pregnancy proceeded to term, and our findings were confirmed in the clinically normal offspring. The problems posed by the presence of the marker chromosome, in terms of both cytogenetic diagnosis and genetic counseling, are discussed in the light of similar cases from the literature.

Differential interferometry of gamma-irradiated optical fibers

An interferometric method is discussed which enables changes in refractive index of irradiated optical fibers to be determined. The method was used to determine the changes of step-index fibers irradiated with 1 krad of gamma rays from a (60)Co source. In one case, relative changes in the core and cladding radii of 3.9% and 1.8%, respectively, and in the core and cladding refractive indices of 2.8% and 2.26%, respectively, have been determined.

Role of cell surface receptor mobility in concanavalin A-induced agglutination of Novikoff hepatoma and normal rat liver cells

The relationshio between Con A-receptor mobility and Con A-induced agglutination of Novikoff hepatoma and normal rat liver cells was investigated. Novikoff cells, incubated with fluorescein-labelled Con A at 3 degrees C displayed uniform, ring-like surface fluorescence. Increasing the temperature of the cells to 37 degrees C caused capping of Con A receptors in approximately 65% of the cells, a phenomenon that could be prevented by prefixing the cells with glutaraldehyde. In spite of these variations in Con A-receptor distribution, Con A-induced agglutination was remarkably constant over a temperature range from 3 to 37 degrees C. In contrast to Novikoff cells, normal hepatocytes displayed a uniform, ringlike surface fluorescence at both 3 and 37 degrees C. No capping was observed. However, hepatocytes, similar to Novikoff cells, were agglutinable by low concentrations of Con A. These findings indicate that, in this model system, Con A-induced cytoagglutination is not dependent upon long-range lateral mobility of Con A receptors. The qualitative differences in the lateral mobility of cell-surface Con A receptors of normal and malignant rat liver cells may represent a marker for neoplastioc transformation during hepatocarcinogenesis, adaptation to growth in ascitic form, or progression of a tumour to a more malignant state.

Comparative studies in two cases of testicular feminization syndrome, one with and the other without the fluorescent distal band q12 of the Y

In two patients with testicular feminization syndrome, one Yq12-positive and the other Yq12-negative, we compared phenotype, gonadal histology and ultrastructure, in vivo steroid response of the testes to the administration of exogenous gonadotropin during adrenal suppression, and of the adrenal gland to ACTH. The assumption that the constitutive Y heterochromatin could function as a regulator of steroid biosynthesis and metabolism, with or without effect at other levels, was not firmly supported by the observations reported here. However, further studies along this line may help elucidate the biologic role of this portion of the Y chromosome in humans.

Kinetics of 21-trisomic lymphocytes. I. In vitro response of 21-trisomic lymphocytes to PHA

Data presented here on the quantitative 3H-thymidine incorporation into DNA, after PHA mitogenic stimulation, show that 21-trisomic lymphocytes are low-responders to PHA compared with the normal-diploid ones. Their responsiveness seems to decrease with the donor's age. Auto-radiographic studies clearly demonstrate that the fraction of labeled cells at the 72nd h of incubation is significantly smaller in the 21-trisomic lymphocyte population. The comparison of labeling indexes at different times of incubation (24, 48, 72 h) also indicate, in the same population, a slower increment of the portion of DNA-synthesizing cells. Discussing these data in the light of other's observations and recent progress in the knowledge of factors and mechanisms involved in the lymphocyte response to lectin mitogenic stimulus, it is suggested that differential distribution of T- and B- and/or T-cell subpopulations and a retarded cell induction time to proliferate may be two important factors negatively influencing the responsiveness of 21-trisomic lymphocyte population.

Familial C/D translocation t(9;13)(9p23.13q21) in a male associated with recurrent abortion

A familial reciprocal translocation, established by R-banding as t(9;13) (9p23;13q21), is described in a phenotypically normal male carrier, whose father is also a balanced carrier and wife had four consecutive spontaneous abortions. The role of translocation in reproductive failure through production of chromosomally unbalanced gametes or by impairment of the spermatogenesis is briefly discussed.

21 ring chromosome in a girl with stigmata of Down's and G deletion I syndromes

An 11-year-old girl with severe psychomotor retardation and other congenital anomalies characteristic of Down's and G deletion I syndromes, was confirmed to be a chromosome 21 ring carrier by R- and G-banding techniques. The dynamics of the ring evolution resulting in a population of complex unstable rings, as in our index case, and the effects of the consequent ring mosaicism are briefly discussed.

The rare allele SOD-A(2) in the Italian population

Data are reported on the distribution of SOD-A electrophoretic phenotypes in the Italian population, and on the concentration of SODA-A-2-1 phenotype in a family group of a small village. The frequency of the rate allele SOD-A(2) is estimated and compared with the frequency in other populations. By applying a model of population dynamics for rare neutral genes estimates are derived of the mean first arrival time and mean age, in generations, of SOD-A(2) allele.

Dosage effect of SOD-A gene in 21-trisomic cells

SOD-A activity was measured by the polarographic method of catalytic currents in 30 subjects 10-24 years of age with a karyotype 47, + 21, and 30 age matched normal subjects. The ratio of the average amount of SOD-A in 21-trisomic cells to the average amount in normal cells is 1.4495. Statistical analysis confirms that this ratio does not differ significantly from the ratio 1.5 expected in the case of a simple gene dosage effect.