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P Gold

Publications and source records attributed to P Gold.

34 records · Page 2Linked to original sources

Alpha1-fetorprotein concentrations in maternal serum during normal pregnancy.

Measurement of amniotic fluid concentrations of alpha1-fetoprotein has been proposed as a potentially important screening test of fetal well-being. Because maternal serum is more easily obtainable, the present study was performed to determine if there is a definable normal pattern of maternal serum alpha1-fetoprotein levels during gestation. Sequential alpha1-fetoprotein determinations were performed throughout gestation on the serums of 151 women having apparently normal pregnancies. Before 13 weeks, all samples contained less than 20 nanograms of alpha1-fetoprotein per milliliter of serum, and in 12.5 per cent of normal pregnancies, alpha1-fetoprotein was still undetectable as late as 21 weeks of gestation. One normal term delivery followed a negative alpha1-fetoprotein determination at the 24th week of pregnancy. Beyond the 21st week of pregnancy, there was a wide range of normal absolute values noted between women at the same stage of pregnancy. Moreover, wide fluctuations in maternal serum concentrations of alpha1-fetoprotein were observed from point to point in specimens from individual women studied longitudinally throughout gestation. The distribution of alpha1-fetoprotein concentrations at each stage of pregnancy was skewed. We conclude that studies of maternal serum alpha1-fetoprotein concentrations are likely to be more meaningful from a diagnostic point of view prior to 21 weeks of gestation, when the range of circulating maternal alpha1-fetroportein values is relatively small. Undetectable maternal serum alpha1-fetoprotein as late as the 24th week of pregnancy is compatible witha viable conceptus. Because unexplained and marked elevations of maternal alpha1-fetoprotein may occur, particularly in the third trimester, it would appear inappropriate to base clinical decision on maternal serum alpha1-fetoprotein measurements alone, and such decisions certainly should not be taken after only single maternal serum alpha1-fetoprotein measurements. Finally, no correlation was found between maternal alpha1-fetoprotein concentrations near term and the birth weight of the infant.

Adolescent

Oncofetal antigens. Increasing the specificity of the CEA radioimmunoassay.

The biologic and clinical significance of the oncofetal antigens carcinoembryonic antigen (CEA) and alpha1-fetoprotein (AFP) are discussed. Although the current assays for these molecules are not tumor-specific, measurement of these molecules in the circulation of cancer patients is useful either for tumor diagnosis or for management of the cancer patient in the postoperative or post-chemotherapy state. An approach to increasing the specificity of the CEA radioimmunoassay is described.

Amniotic Fluid

beta 2-microglogulin levels in cancerous and other disease states.

Serum beta2-microglobulin levels were measured, by radioimmunoassay, in patients suffering from a variety of benign and malignant clinical disorders. Elevated beta 2-microglobulin values were found in neoplastic and non-neoplastic disorders affecting a variety of organs. The most striking increases in beta 2-microglobulin are found in the plasma cell dyscrazias and several solid tumors, particularly those affecting the lung. Lymphoid neoplasms demonstrate a spectrum of changes of serum beta 2-microglobulin. At the one end of this spectrum were the plasma cell tumors, which show a high incidence of raised beta 2-microglobulin levels, while patients with Hodgkin's disease rarely show such increases in circulating beta 2-microglobulin.

Beta-Globulins

Chromosomal assignment of the HL-A common antigenic determinants in man-mouse somatic cell hybrids.

In the study presented here, man-mouse somatic cell hybrid clones were examined by means of radioimmunoassays for the presence of both beta2-microglobulin (beta2m) and the HL-A xenoantigenic determinant. In addition, the clones were examined for their karyotype and the expression of enzymes with known chromosomal assignments. The results obtained indicate that the gene coding for the HL-A xenoantigenic determinant is carred on chromosome 6. The data obtained provides a direct demonstration that the gene coding for beta2m segregates independently of that coding for the alloantigenic polypeptide chain of the HL-A molecule, and that the gene coding for beta2m is carried on chromosome 15.

Animals

Heterogeneity of the protein moiety of carcinoembryonic antigens.

N-terminal amino acid sequences were determined for the protein moiety of carcinoembryonic antigen (CEA) isolated from three colon cancers that had metastasized to the liver. The results showed that the polypeptide portion of CEA preparations isolated from different tumors are not identical. Furthermore, each CEA preparation appeared to be heterogeneous within itself, since multiple amino acid residues were recovered at most of the positions following stepwise cleavage of the protein moiety of CEA molecules by automatic Edman degradation.

Amino Acid Sequence

The isolation and characterization of tumor-specific antigens of rodent and human tumors.

Putative tumor-specific transplantation antigens (TSTA) from both a carcinogen-induced rodent tumor (MC-1) and 2 human tumors were purified. The antigens were solubilized from the tumor cell membranes by limited papain digestion in a manner similar to that described for the isolation of normal histocompatibility antigens. The antitumor immune response of the tumor-bearing host was used to monitor the purification of the putative TSTA in both the rodent and human tumor systems. In the case of the rodent tumor, a major step in the purification of the TSTA involved affinity chromatography on Sepharose beads coupled to autologous antitumor antiserum. A comparable procedure was utilized in the purification of the TSTA from human tumors by using affinity chromatography on anti-human beta2-microglobulin antiserum coupled to a solid phase. The data obtained indicate that the TSTA of human tumors contains a beta2-microglobulin chain that is immunochemically identical with, and very similar in size to, that found in normal human histocompatibility antigens. A subunit of similar size was also identified in the carcinogen-induced rodent tumor. These results suggest that the TSTA in both humans and rodents may well be altered histocompatibility antigens.

Animals

Studies of the linkage relationship of beta-2-microglobulin in man-mouse somatic cell hybrids.

Beta-2-microglobulin (beta2mu) production has been studied in 33 primary man-mouse hybrid clones and in 26 secondary man-mouse hybrid clones. These clones have also been examined for the presence of 15 human enzyme phenotypes. Karyotypic analyses have been carried out on clones. From these studies the following conclusions can be drawn: (1) Gene(s) determining human beta2mu production in humans are apparently syntenic with the MPI gene on chromosome 15. (2) Long-term fibroblast lines may be of limited use in mapping studies as chromosomal rearrangements frequently occur in these lines. (3) The gene(s) determining beta2mu production in humans segregate independently of chromosome 6. If the assignment of the genes determining HL-A alloantigens to chromosome 6 is correct, our results imply that beta2mu and HL-A alloantigens are determined by genes carried on different chromosomes, despite the fact that beta2mu forms an integral part of the HL-A molecule.

Animals

Dietary protection during radiation therapy.

Eighteen patients receiving Cobalt 60 irradiation for abdominal or pelvic malignancies were assigned at random to eat either a semi-hydrolyzed diet (Flexical: 10 g % casein hydrolsate; 14 g % triglycerides, 20% of which medium chain; 66% disaccharides) or a normal diet. There are no significant differences between these two groups with respect to age and the ratio of ideal to actual caloric intake. The patients in the control group received on the average a total of 3900 rd and those in the Flexical group 4040 rd. Generally, Flexical appeared to have a significant positive effect on body weight. In addition, radiation-induced diarrhea was not a problem in the Flexical group. In the latter group, serum proteins including immunoglobulins remained essentially unchanged during therapy while a moderate but significant fall was observed in all control patients. No significant difference between the two groups was observed with respect to peripheral blood hematocrit, red and white cell counts. However, the drop in blood lymphocytes following irradiation was significantly less in the Flexical group. The mechanisms of radioprotection are discussed. These preliminary data indicate that the nutritional and perhaps the immunological status of cancer patients receiving intensive irradiation can be maintained by dietary measures.

Abdominal Neoplasms