Studies on the activity of phorbol myrystate acetate on the human polymorphonuclear leukocytes

Summary Phorbol myrystate acetate (PMA) activates nitroblue tetrazolium reduction in human polymorphs. The activation is inhibited by dibutyryl cyclic AMP, theophylline and phenylbutazone, but is not influenced by hydrocortisone in vitro, nor is it inhibited by leukocytes from patients treated with prednisone. Peptide analogues of Tuftsin also had no effect on this stimulatory activity. We conclude that the action of PMA on the nitroblue tetrazolium reduction is mediated through cyclic nucleotides.     

Development of photosystem I and onset of generative phase in buckwheat

Summary The length of the generative phase and the development of photosystem I in buckwheat cotyledones were found to be correlated. Increasing days of light exposure help both of these processes. It is presumed that electron transfer during energy absorption probably serves as a prelude to further molecular events leading to the onset of the generative phase.A.N.P. is thankful to USSR Academy of Sciences and U.G.C. India for financial assistance for his visit under Cultural Exchange Programme and to Miss T.I. Vyacheslavova for helping as an interpreter during the visit. Suggestions from Acad. M.Kh. Chailakhyan during this work are duly acknowledged.     

Zinc deficiency and lung converting enzyme activity in rats

Summary Angiotensin converting enzyme activity was found to be significantly decreased in the isolated perfused lung from zinc-deficient rats when compared with that of controls. Addition of zinc ion to the superfusion medium did not cause a recovery in this decreased activity of the enzyme. It is postulated that zinc deficiency probably produces a structural change in the lung angiotensin converting enzyme.This work is supported by a grant from Turkish Scientific and Technical Research Council (TAG-350).     

Tat protein of HIV-1 stimulates growth of cells derived from Kaposi's sarcoma lesions of AIDS patients

Kaposi's sarcoma (KS) is frequently associated with human immunodeficiency virus-1 (HIV-1) infection. Supernatants from HIV-1-infected T cells carrying the CD4 antigen promote the growth of cells derived from KS lesions of AIDS patients (AIDS-KS cells), and the HIV-1 tat gene, introduced into the germ line of mice, induces skin lesions closely resembling KS. Here we report that the tat gene product (Tat) is released from both HIV-1-acutely infected H9 cells and tat-transfected COS-1 cells. These Tat-containing supernatants specifically promote growth of AIDS-KS cells which are inhibited by anti-Tat antibodies; recombinant Tat has the same growth-promoting properties. Therefore a viral regulatory gene product can be released as a biologically active protein and directly act as a growth stimulator. These and previous data indicate that extracellular Tat could be involved in the development or progression, or both, of KS in HIV-1-infected individuals.     

Molecular weight of virus-induced tortoise interferon in cell cultures

Zusammenfassung Das Molekulargewicht des Interferons, durch Selmiki Forest Virus in Zellkulturen von Schildkrötenniere induziert, wurde mittel Gelchromatographie mit Sephadex G-100 bestimmt und es ergab sich ein Wert von 33,500.     

Haloperidol produces hypothermic effects in rats

Intraperitoneal administration of either haloperidol or chlorpromazine produced hypothermia both in the cold (8 degrees C) and at room temperature (22 degrees C). The hypothermia was brought about both by a decrease in metabolic heat production and an increase in the cutaneous temperature of tail and foot skin. However, at a higher temperature (29 degrees C), there were no changes in rectal temperature and other thermoregulatory responses.