Stress and breast cancer

In order to assess whether exposure to stress was associated with an increased risk of breast cancer, 100 women presenting with carcinoma of the breast completed a standard life events inventory documenting life stresses experienced during the previous three years. The same questionnaire was completed by 100 women presenting with benign breast lumps and 100 apparently healthy controls. Both groups of patients with breast disease also completed the Eysenck personality inventory. There was no difference in the number of stressful life events experienced by the patients with benign and malignant breast lesions and the nature and severity of those stresses encountered were similar for both groups. The personality indices were also the same for both groups. The controls, however, recorded significantly higher levels of stress exposure than the patients with breast disease. On the basis of this series, there is no evidence to support the hypothesis that stress predisposes to breast cancer development.

Measurement using tracers of steady-state turnover and metabolic clearance of insulin in dogs

In nine conscious dogs, the steady-state metabolic clearance rate (MCR) and the systemic appearance rate (Ra) of insulin were determined by the tracer dilution method. [3H-PheB1]insulin ([3H]insulin) was infused as a tracer from time 0 at a constant rate. After tracer equilibration was attained, unlabeled porcine insulin was infused at variable constant rates (10.6-279 mU/min) with somatostatin (0.3 microgram . kg-1 . min-1) to suppress endogenous insulin secretion. Glucose was infused to prevent hypoglycemia. Tritiated and immunoreactive insulin (IRI) concentrations were determined in plasma samples after extraction on a C-18 reverse-phase column. Tracer-determined basal Ra of insulin was 2.39 +/- (SE) 0.61 mU/min. The calculated steady-state Ra of insulin for plasma IRI from 20 to 2,300 microU/ml showed good agreement with insulin infusion rates. The mean ratio of these rates was 0.973 +/- 0.018. The MCR of insulin under basal conditions was 29.9 +/- 3.4 ml . kg-1 . min-1, and it decreased with increasing insulin concentrations. It is concluded that 1) insulin turnover rates can be measured accurately using [3H]insulin as a tracer and 2) insulin kinetics are nonlinear.

Enhancement of human amniotic cell growth by Ficoll-Paque gradient fractionation

Ficoll-Paque isopycnic centrifugation was used as a preparative procedure for amniotic fluid (AF) cells prior to tissue culture. This technique serves to reduce contaminating erythrocytes and also enhances cell growth or mitotic indices. The technique described in this report yields three subfractions designated as a turbid interphase layer (F-2), a middle cell layer (F-3), and a bottom pellet (F-4). The middle cell layer (F-3) demonstrated better cell growth and higher mitotic index than any of the other fractions or control unfractionated amniotic fluid cells. The use of Ficoll-Paque isopycnic preparative centrifugation of amniotic fluid cells is a valuable adjunct in cell culture for cytogenetic analysis. This may be especially true when amniotic fluid contains large numbers of erythrocytes.

Diagnosis of a triploid fetus at genetic amniocentesis

Nearly 20% of spontaneously aborted fetuses with chromosomal errors have been shown to have a triploid karyotype. Such a fetus is rarely encountered during the course of an amniocentesis at midtrimester. Because amniotic fluid cell polyploidy is an occasional finding among normal fetuses at midtrimester, the following report illustrates the importance of gathering corroborative evidence of an affected fetus before arriving at a prenatal diagnosis.

Enhanced Growth of amniotic fluid cells in presence of fibroblast growth factor

A shorter period of time between amniocentesis and cytogenetic diagnosis is of considerable clinical usefulness. Fibroblast growth factor (FGF), a potent mitogen for cells of mesodermal origin, was used to enhance the growth rate of primary cultures of amniotic fluid-derived cells. At the initial harvest and at 5 scored metaphases, culture dishes incubated with FGF showed a 9-day advantage as a group when compared with their untreated, paired controls. In addition, less variability was encountered in the growth time of the FGF-treated dishes; 97% of these treated dishes were harvested initially between 10 and 20 days, while only 48% of the control dishes were harvested initially during this time period. Success was also noted in the recovery of failing cultures. The addition of FGF to the standard enriched medium used in amniotic fluid cell cultures has shortened the processing time and provided a more uniform growth rate in the majority of cultures studied.

Del (10)p autosomal deletion syndrome: clinical, cytogenetic and gene marker studies

A 46,XX,del(10)p13 karyotype (Paris Conference, 1971) was identified in a 5-year-old Negro girl with mental and growth retardation, brachy- and trigonocephaly, downward slanting palpebral fissures, hypotelorism, epicanthal folds, ptosis, strabismus, dysplastic nose, high-arched palate, microdontia, small low-set posteriorly rotated ears, asymmetrical thorax, wide-spaced nipples, and minor abnormalities of hands and feet. Both parents and a brother had normal karyotypes. Expression of more than 50 polymorphic gene loci determining blood groups, serum proteins and red cell enzymes was studied. The results did not permit localization of a gene locus on the deleted segment of chromosome 10. The proposita was heterozygous for the Rh and MN blood groups and for the red cell enzymes adenosine deaminase, glutamate pyruvate transaminase and esterase D. These gene loci are thereby excluded from region 10p13 yields 10pter.

Dinitrophenyl-reactive immunoglobulins in the serum of normal bowfin, Amia calva

The sera from unimmunized bowfin agglutinate a large variety of red cells. Although they precipitate DNP-BSA they manifest only slight agglutinating capacity for DNP-coated cells. 15S immunoglobulin isolated by DEAE-cellulose chromatography followed by Sephadex G-200 gel filtration possessed a high level of broad reactivity towards unmodified DNP-coated cells, whereas the 7S immunoglobulin isolated by this procedure was inactive. However, following precipitation of whole serum with DNP-BSA both molecules could be recovered in a form which demonstrated specificity for DNP, in that both precipitated DNP-BSA and agglutinated DNP-coated cells but not unmodified cells. The mechanism of activation of the 7S molecule is not known but the data suggest that this immunoglobulin is divalent.