A study on serum cancer-suppressive peptide

A peptide which was isolated from serum of cancer-bearing mice has an activity to kill cancer cells in vitro, but little effect on bone marrow cells. This peptide was named Serum Cancer-Suppressive Peptide (SCSP). SCSP can be crystallized and still has the activity to kill the cancer cells. It consists of more than ten kinds of amino acids with molecular weight about 2000-3000 daltons estimated by SDS-polyacrylamide gel electrophoresis. An antiserum was prepared from rabbits immunized with SCSP and the corresponding IgG could be obtained from the antiserum. The titers of SCSP in some cells of the normal and cancer-bearing mice were estimated by passive hemagglutination method. The results showed that the SCSP titer in spleen is much higher than those in muscle, liver and ascites tumor cells. The results suggest that SCSP is probably produced by spleen cells.

Mosaicism or pseudomosaicism: the problem of hypermodal cells in amniotic fluid cell culture

A series of 2029 consecutive amniotic fluid specimens studied for prenatal genetic diagnosis were reviewed and reassessed so as to evaluate the frequency and clinical significance of hypermodal cells in amniotic fluid cell cultures. Hypermodal cells were defined as those with more than 46 chromosomes, and were characterized by an additional structurally normal or structurally abnormal chromosome. Of 2029 specimens, 47 (2.31 per cent) contained a total of 167 hypermodal cells. True fetal mosaicism was detected in three cases (0.14 per cent). All had hypermodal cells in more than one culture flask or colony which contained the same aberrant chromosome complement. In all but one case the babies were normal when only one cell was hypermodal, or when several cells were hypermodal but present in only one colony or one culture vessel. One case had an extra No. 20 chromosome in one cell. Although the child had multiple anomalies, they were not characteristic of trisomy 20, and subsequent chromosomal study on the baby postnatally revealed a 46,XX karyotype. The in situ coverslip technique is recommended as the preferred method for prenatal diagnosis, and it is useful as an aid in differentiating true mosaicism from pseudomosaicism.

Evaluation of inorganic pyrophosphate in amniotic fluid as a mode of prenatal diagnosis of osteogenesis imperfecta

Using a modified procedure by Solomons and Styner (1969), an evaluation of inorganic pyrophosphate (PPi) was performed on the amniotic fluid of two fetuses at risk for osteogenesis imperfecta (OI) at 14 1/2 weeks gestation. The parents of both cases had a previous child with OI, Type II. The normal control group at 14-16 weeks gestation had PPi values ranging from 22.0-59.2 micrograms/100 ml, with a mean of 38.6 +/- 9.51 micrograms/100 ml. In each at-risk fetus, the amniotic fluid PPi value was within normal range. The first baby was born phenotypically normal at term. Intrauterine radiographic and fetal sonograms were done on the second fetus at approximately 19 weeks gestation. Both showed evidence of OI, Type II. The pregnancy was terminated at 21 weeks. Radiologic studies of the aborted fetus were consistent with OI, Type II. Our results indicate that the evaluation of PPi levels in amniotic fluid is not the method of choice for prenatal diagnosis of OI.