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Biomedical subjects

H Rappaport

Publications and source records attributed to H Rappaport.

At least 145 records · Page 8Linked to original sources

Staging laparotomy in non-Hodgkin's lymphoma.

In 57 patients with non-Hodgkin's lymphoma, a clinical, radiographic, scintigraphic and pathological correlative study showed the following results: (1) the inferior venacavagram, lymphangiogram and gallium-67 scan have a low sensitivity in detecting lymphoma: their accuracy is high when the findings are interpreted as abnormal (93%, 83% and 80% respectively), but low when they are interpreted as normal (47%, 67% and 58% respectively); (2) the clinical evaluation of spleen and liver is unreliable; (3) the incidence of lymphocytic lymphoma in the para-aortic-iliac nodes is high; (4) a pattern of involvement by contiguity and a predilection for the spleen were observed in lymphocytic lymphoma; (5) in lymphocytic lymphoma there is no liver involve without concomitant splenic involvement; (6) no definite pattern of spread could be seen in histiocytic lymphoma; (7) surgical staging changed the classification of the lymphoma in 56% of cases, 46% being reclassified to a more advanced stage; (8) surgical staging significantly improves the assessment of the stage of disease and therefore permits accurate treatment planning.

Adolescent↗

Histologic reactions of the thymus, spleen, liver and lymph nodes to intravenous and subcutaneous BCG injections.

The tissue reactions of non-tumor-bearing F1 (DBA/2 X C57B16) mice to i.v. and s.c. injected BCG were studied in animals sacrificed at planned intervals following the injection. No appreciable changes were observed prior to day 6, when the thymic cortex and medulla began to show hyperplasia of epithelial cells; many of them had PAS positive cytoplasm and some of these cells were contiguous with the walls of small blood vessels and large cystic spaces containing PAS-positive secretions. The thymic cortical lymphocytes showed, on day 6, a pronounced pyroninophilia and increased mitotic activity without increase in thymic weight. These changes were considerably more striking in the i.v. than in the s.c. injected animals. On the same day a pronounced multifocal lymphocytic infiltration involving the red pulp and the parafollicular and periarteriolar zones of the spleen were observed. It was more pronounced in the i.v. than in the s.c. injected animals. The thymic changes were seen only in animals killed on day 6 and day 10, but were no longer observed on day 14. Beginning with day 14 a pronounced histiocytic granulomatous reaction was observed in the liver. On day 18, this granulomatous reaction was also seen in the spleen, lymph nodes, and lungs of i.v. injected animals. It persisted until day 45. In the s.c. injected animals histiocytic granulomas were seen only at the site of injection and in the regional lymph nodes.

Animals↗

Some acridine-resistant mutations of bacteriophage T4D.

Three new 9-aminoacridine (9AA) resistant mutations of bacteriophage T4D have been isolated and characterized. Two of the mutations, rs and rc, have identical patterns of acridine resistance, but they map on opposite sides of the rII region. In addition, rs has an effect on the plaque morphology of r mutations, whereas rc does not. The third mutation, ama, maps very close to rs but exhibits a different pattern of resistance to 9AA. None of the three is resistant to acridines by virtue of reduced permeability. Taken together with other mutations that have been previously characterized, these new mutations permit us to set the minimum number of acridine-sensitive processes in T4 development at four.

Acridines↗

Diaminopurine-resistant mutants of cultured, diploid human fibroblasts.

Clones of cells resistant to 2,6-diaminopurine were detected in skin fibroblast cultures derived from 13 of 21 normal humans of both sexes from 17 unrelated families. Almost all of the cultures that yielded mutants were chosen for further study from among a total of 83 surveyed because they displayed a slight resistance to low concentrations of diaminopurine. The incidences of mutant colonies ranged between about 10(-5) and 10(-4) per cell surviving prior mutagenic treatment with MNNG. The incidences of spontaneous mutants were about 10(-7) to 10(-5) in three unrelated cultures. Most independent mutants had distinctly reduced activity of adenine phosphoribosyltransferase but some had apparently normal amounts of activity. Two mutants from unrelated boys had little or no detectable enzyme activity and were unable to effectively use exogenous adenine for growth when purine biosynthesis was blocked with azaserine. Most mutants could utilize exogenous adenine, just as most azaguanine-resistant fibroblast mutants can utilize exogenous hypoxanthine, even when their hypoxanthine-guanine phosphoribosyltransferase activity is reduced. Diverse genetic changes conferred diaminopurine resistance but their specific natures are still undefined. Gross numerical or structural chromosome abnormalities were not observed in the mutants examined so far. Since at least one gene responsible for adenine phosphoribosyltransferase activity is on autosome No. 16 our results suggest that at least some of the cultures yielding mutants were heterozygous and that alleles conferring diaminopurine resistance may be frequent enough to comprise a polymorphism.

Adenine↗