Responses of chronic lymphocytic leukemic lymphocytes to increasing concentrations of phytohemagglutinin during short-term culture.

Lymphocytes obtained from CLL patients containing high and low peripheral lymphocyte cell counts were cultured in the absence and presence of increasing concentrations of phytohemagglutinin for periods of up to 2 h. Lymphocytes from patients with low cell counts (less than 50,000/mm3) were stimulated to incorporate 3H-uridine during the 1st h of culture by concentrations of PHA ranging from 1 to 32 microgram/ml. Under identical conditions, lymphocytes from patients with high cell count (greater than 50,000/mm3) were barely affected. During the 2nd h of culture the above concentrations stimulated to a lesser degree the former group of lymphocytes, whereas it inhibited incorporation by the latter group. The results obtained suggest a qualitative difference in the response of CLL lymphocytes to PHA in accordance with the progression of the disease.

Cortisol resistant RPMI-1788 lymphocytes become sensitive to cortisol subsequent to a 24-h incubation period in medium containing purified human transcortin.

RPMI-1788 lymphocytes (a human cell line) are resistant to cortisol in vitro. Prior incubation for a minimum of 24 h in a medium which contains purified human transcortin at a concentration of 50 micrograms/ml renders these cells sensitive to the inhibitory action of cortisol as regards the synthesis of DNA. Only the transcortin-exposed cells contain a cortisol binding species whose sedimentation behavior in a sucrose gradient is identical to that of transcortin.

Placenta, transcortin, and localized immune response.

The syncytiotrophoblastic cells of the human placenta contain a cytoplasmic protein recognized by fluorescein-labeled transcortin-specific antibody. Purification of this protein from human placenta, by those methods employed for the purification of human plasma transcortin, yielded a protein that exhibited antigenic and biochemical similarity to plasma transcortin. Placental transcortin differs from plasma transcortin in that it has a smaller sedimentation coefficient (3S vs 3.75S) and binds cortisol less strongly. This purified protein is able to block the phytohemagglutinin response of maternal lymphocytes even more than serum transcortin. It is postulated that the biological role may be that of inhibiting the maternal cell-mediated immune response to the presence of the antigenic conceptus.

Electrophoretic abnormalities in chronic lymphocytic leukemia and cancer sera.

It was previously shown (Am J Clin Pathol 55: 65-67, 1971) that sera from patients with chronic lymphocytic leukemia (CLL) produce a characteristic pattern on disk-acrylamide gels. Other observations indicating the presence of immunosuppressive proteins in the sera of patients with cancer suggested the search for characteristic protein patterns employing the same technic. Utilizing sera from patients with various types of malignancies and appropriate controls, the results appear to indicate that there is a consistent and distinctive pattern to the gels. The nature of the (different) protein(s) remains to be elucidated.

Corynebacterium aquaticum septicemia. Characterization of the microorganisms.

An 85-year-old woman with the diagnosis of diabetic ketoacidosis developed septicemia during hospitalization. Cultures of the patient's blood revealed the presence of Gram-variable coccobacilli, later identified as Corynebacterium aquaticum. The microorganisms grew aerobically on blood agar plates after incubation overnight. The colonies were convex, non-hemolytic and slightly yellow-pigmented. No growth was observed on MacConkey and endo agar plates. The organisms were catalase-positive, oxidase-negative, motile, and oxidized glucose and mannitol. The morphologic and biochemical properties of Corynebacterium aquaticum should be considered for separation from related organisms such as Listeria monocytogenes, Corynebacterium species and oxidative Gram-negative rods that do not grow on MacConkey medium (Flavobacterium spp.).

Effect of cortisol on the ultrastructure of normal, leukemic, and cultured human lymphocytes.

The effect of cortisol on the ultrastructure of normal, leukemic, and cultured human lymphocytes during a 2-hr incubation was investigated. The presence of 10(-5) M cortisol in the incubation medium produced in normal lymphocytes a variety of alterations in cytoplasmic organelles. Mitochondria were most affected and showed evidence of irreversible deterioration (formation of myelin figures). Occasional cells demonstrated an overt rearrangement of their cytoplasmic membranes resulting in a bizarre array of parallel cisternae-like structures. More commonly, the usually underdeveloped Golgi of normal lymphocytes became very pronounced in structure. All of these alterations were produced within 2 hr of incubation, but only in normal human lymphocytes. Under identical conditions, no evidence of ultrastructural changes were produced by cortisol in either lymphocytes from chronic lymphocytic leukemic patients, or those from the RPMI 1788 cell line.

Cardiobacterium homonis endocarditis. Characterization of the unusual organisms and review of the literature.

A case of subacute bacterial endocarditis in which Cardiobacterium hominis was isolated from the blood of a 55-year old woman who had rheumatic heart disease is reported. A survey of the literature revealed very few reports in which this organism has been implicated in human lesions. The colonies grew after 48 hours of incubation in a candle jar. They were small, convex, nonhemolytic, and oxidase-positive. The indole reaction was positive, the catalase and nitrate reactions were negative, and acid reaction was obtained from the following carbohydrates: glucose, maltose, mannitol, sucrose, and sorbitol. The morphologic and biochemical properties served to distinguish these organisms from similar bacteria implicated in human disease, such as Haemophilus aphrophilus, Actinobacillus actinomycetemcomitans, Streptobacillus moniliformis, and HB-1.

Effect of cyclic guanosine 3,5-monophosphate on the synthesis of enzymes sensitive to caatabolite repression in intact cells of Escherichia coli.

Cyclic guanosine 3',5'-monophosphate inhibits the synthesis of beta-galactosidase and tryptophanase in cultures of Escherichia coli growing in minimal media with glucose or glycerol as the carbon source. Cyclic guanosine 3',5'-monophosphate acts at the transcriptional level in the lac operon, it exerts its action at the promoter site of the operon, and requires the presence of functional cyclic adenosine 3',5'-monophosphate receptor protein.

Use of streptomycin and cyclic adenosine 5'-monophosphate in the isolation of mutants deficient in CAP protein.

A method is described for selective isolation of mutants deficient in CAP protein necessary for the expression of catabolite-sensitive operons in Escherichia coli.