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.     

Experimental desquamation of intestinal epithelium for in vivo studies of regeneration.

Complete removal of villous as well as upper-crypt epithelium was achieved in vivo by vibration of an intestinal segment using tetraphenylboron sodium (TPB) as a disassociation agent.     

On the binding of steroid sulfates to albumin

Summary ³H-Labeled steroid sulfates, sulfate of estrone (E₁S) or dehydroepiandrosterone (DHAS), were dialyzed against delipidated human serum albumin or human plasma in the presence of increasing amounts of competing non-labeled sulfates (DHAS or E₁S). The apparent equilibrium constants (K) of the tracers did not measuraby change at concentrations of the non-radioactive sulfates below 10^–5 mol/l. At higher concentrations, K decreased gradually. The apparent equilibrium constant of³H-E₁S was diminished by plasma in a similar fashion. It may be concluded that albumin possesses one strong, non-specific binding site. This site, however, does not seem to be utilized for the binding of E₁S in vivo, because of its preferetial occupation by other ligands. This may be true for other steroid sulfates as well, depending on their relative abundance in plasma.Acknowledgment. This investigation received financial support from the Special Programme of Research, Development and Research Training in Human Reproduction, World Health Organisation, and from the Ford Foundation.