Induction of autogamy by transfer of macronuclear karyoplasm in Paramecium tetraurelia

Macronuclear karyoplasm was transplanted from pre-autogamous donor cells (clonal age, 22 fissions) into the macronucleus of young recipient cells (2 fissions after autogamy occurred) by means of microinjection. A reciprocal experiment was carried out by injecting karyoplasm from young clonal age donors into pre-autogamous recipients. In the case of karyoplasm transfer from pre-autogamous donors to young recipients, autogamy occurred early in 67% of injected cells, whereas reciprocal injections had no influence on the onset of autogamy, and all of the injected cells underwent autogamy. Such results indicate a distinct role of pre-autogamous cells of macronucleus in the induction of autogamy.

Chinese and African Euphorbiaceae plant extracts: markedly enhancing effect on Epstein-Barr virus-induced transformation

Chinese and African Euphorbiaceae plant extracts were shown to have a markedly enhancing effect on Epstein-Barr virus (EBV)-induced transformation of human lymphocytes. When 5 X 10(5) cord blood lymphocytes were seeded into the semisolid agar medium immediately after EBV exposure, 3-10 times more colonies developed in the presence of the plant extracts at their optimal doses. When a smaller number of 5 X 10(4) cells were seeded, transformed colonies were also observed in the presence of the plant extracts but not in their absence. All of the colonies picked up from the agar medium were EBV-determined nuclear antigen (EBNA)-positive and showed the typical blastoid morphology. There were no colonies detected in the EBV-uninfected cultures with the extracts, indicating that the virus was required for the promotion by these plant extracts of this lymphocyte transformation. Euphorbiaceae plants are known to be employed as local herbal drugs in southern China and tropical Africa, and the possible role as a co-factor of the plant extracts in the development of nasopharyngeal carcinoma (NPC) and African Burkitt's lymphoma (BL) is discussed.

Expression of Ia-like antigens defined by monoclonal OKIal antibody of hemopoietic progenitor cells in cord blood: a comparison with human bone marrow

Expression of Ia antigens on granulocyte/macrophage colony-forming cells (CFU-GM) in human cord blood was compared with that in bone marrow with the use of monoclonal OKIal antibody. Mononuclear cells prepared from cord blood and bone marrow were pretreated with OKIal antibody plus complement, and, thereafter, the ability of cord blood and bone marrow cells to form colonies of CFU-GM was assayed in semisolid agar culture. Consistent reduction in the number of CFU-GM in cord blood to 58.8% +/- 13.0% (mean +/- SD) of controls treated with complement alone was shown after elimination of Ia-antigen-bearing CFU-GM, but was significantly remarkable than that in bone marrow (18.0% +/- 5.6%). Although the reduction of both granulocyte (CFC-G) and macrophage colony (CFC-M) types of cord blood, characterized by the double staining for esterase activity, was shown following treatment with OKIal antibody plus complement, the relative inhibition of CFC-G weas significantly greater than that of CFC-M (p less than 0.02). These results suggest some differences in the characteristics of Ia-antigen-bearing CFU-GM between cord blood and bone marrow cells. Furthermore, it is suggested that Ia-dependent regulatory mechanisms might participate in the differentiation of CFU-GM to CFC-G and CFC-M.

Porto-pulmonary venous anastomosis in portal hypertension demonstrated by percutaneous transhepatic cine-portography

Analysis of portal collaterals by percutaneous transhepatic portography combined with cine-fluorography disclosed porto-pulmonary venous anastomosis in four out of 22 patients with portal hypertension. The characteristic radiological features were a sudden spurt of contrast medium from a venous collateral located near the hilus of the left lung and counterclockwise movement of the flux of contrast medium, which was rapidly diluted; this was synchronized with the cardiac beat. The clinical significance of the porto-pulmonary anastomosis as a potential channel for the migration of embolizing materials used in the obliteration of varices is discussed.

Inhibition of phenylalanine hydroxylase, a pterin-requiring monooxygenase, by oudenone and its derivatives

Phenylalanine hydroxylase was shown to be inhibited by oudenone and its derivatives in vitro. At a concentration of 2.3 x 10(-3) M, oudenone inhibited phenylalanine hydroxylase by 50%, and some of the oudenone derivatives showed more potent inhibition. The kinetic data have shown that the inhibition by oudenone is competitive with a tetrahydropterin cofactor (6,7-dimethyltetrahydropterin, DMPH4) and noncompetitive with phenylalanine and oxygen. Among 12 oudenone derivatives, there was no parallel structure-activity relationship between the inhibitory effect for phenylalanine hydroxylase and that for tyrosine hydroxylase. A derivative of oudenone, [compound No. 142; 2-(3,4-dihydroxyphenyl)-1-oxopropyl)cyclohexan-1,3-dione] showed the most potent inhibition among the oudenone derivatives. It inhibited phenylalanine hydroxylase by 50% at a concentration of 1.8 x 10(-5) M. This inhibition was a mixed type with either a tetrahydropterin cofactor, DMPH4, or with the substrate phenylalanine, which was different from the inhibition by oudenone. However, the same noncompetitive inhibition was shown toward oxygen.

Swine cerebrospinal angiopathy and demyelination and malacia

In 15 pigs affected with cerebrospinal angiopathy accompanied by demyelination and malacia, the main symptoms were diarrhea and subsequent circling, spasms, sudden forward movements, ataxia, and inability to hold the head straight. Escherichia coli was isolated in a pure culture from the small intestine of pigs with diarrhea. The only gross change was a slight increase in cerebrospinal fluid. Histologic examination showed vascular lesions, demyelination, and malacia, most commonly located in the medulla oblongata, pons, and midbrain. The vascular lesions were degenerative and there were necrotic changes of the vessel walls and formation of periodic acid-Schiff positive perivascular eosinophilic droplets. Ultrastructurally, the swollen astrocytes around the vessels had many osmiophilic bodies in their cytoplasm with no limiting membrane. Demyelination and malacia, as well as vascular lesions, were considered to be the characteristic changes of cerebrospinal angiopathy. Our study suggests that E. coli may be a cause of cerebrospinal angiopathy.

Valve replacement of childhood: follow-up results and complications

This study concerned 18 cases of value replacement in patients than 15 years, between 1964 and 1980. In this period, there was a total of 30 such cases, but there were eight hospital deaths and four cases with less than two years postoperative observation. These 12 cases were excluded from the study. The average follow-up period of the 18 cases was eight years and nine months. During this period, six cases were associated with postoperative complications, which consisted of three cerebral emboli, two malfunctions of the implanted prostheses and one congestive heart failure. Three cases involved prosthesis-related death. Secondary implantations were performed in two cases; one for relative stenosis of the prosthesis and the other for calcification of the porcine xenograft. Physical activity in the 15 survivors has been excellent in all but two cases with arrhythmia and sequelae of cerebral damage due to surgery.

Characterization of hemopoietic stem cells (CFUc) in cord blood

Some properties of hemopoietic stem cells (CFUc) in human cord blood and peripheral blood of neonates were compared with those in bone marrow, by the method for in vitro growth of colony-forming cells in semisolid agar. The number of CFUc circulating in cord blood was 93.5 +/- 57.8 (mean +/- 1 SD)/10(5) cells, which was slightly less than that of bone marrow. The number of CFUc in peripheral blood decreased promptly following birth. From cord and neonatal blood, most colonies were monocyte/macrophage colonies (60.0 +/- 4.6%), whereas those from bone marrow were largely granulocyte colonies (88.3 +/- 6.2%). The differences of growth curve, colony size, and turnover state of CFUc between cord blood and bone marrow seemed, in part, to result from the dominancy of monocyte/macrophage colony-forming cells in cord blood. The cell cycling rate of CFUc in cord blood was remarkably lower than that in bone marrow. From these results, it seems clear that CFUc in cord blood differ in some aspects from those in bone marrow. However, the precise physiologic and functional significance of CFUc circulating in cord and neonatal blood remains unknown.

Humoral helper activity for B-cell differentiation released from non-Hodgkin's lymphoma cells having both SRBC and complement receptors in the pokeweed mitogen system

The majority of lymphoid cells from a patient with non-Hodgkin's lymphoma with leukemic transformation were demonstrated to carry receptors for both sheep erythrocytes and complements by the combined rosette assay using neuraminidase-treated sheep erythrocytes and complement-coated zymosan beads. Most of them were considered morphologically lymphoblasts and were positive for acid phosphatase staining. Terminal deoxynucleotidyl transferase activity was not detected in these cells. Lymphoid cells from this patient did not respond to the stimulation with phytohemagglutinin-P, concanavalin-A, and pokeweed mitogen (PWM). When these cells were cultured with PWM for 7 days, no plasma cell was generated. Although only a few plasma cells were generated in the PWM-stimulated culture of normal purified B cells alone, the addition of the patient's cells to purified normal B cells resulted in a markedly enhanced generation of plasma cells in response to PWM, as was the case with normal T cells. But leukemic cells either from a patient with T-cell leukemia not having complement receptors or from a patient with null-cell leukemia showed no enhancing ability in B-cell differentiation. In addition, the culture supernates of the patient's cells obtained after 24-hr PWM stimulation had an ability to promote B-cell differentiation comparable in activity to those from the PWM-stimulated normal T cells.