Worcester Foundation for Biomedical Research

About: Worcester Foundation for Biomedical Research is a based out in . It is known for research contribution in the topics: Estrone & Estrogen. The organization has 2195 authors who have published 2646 publications receiving 115809 citations. The organization is also known as: Worcester Foundation for Experimental Biology.

Electron micrographic studies of transport of oligodeoxynucleotides across eukaryotic cell membranes.

Abstract: Unmodified oligodeoxynucleotides (ODNs) were synthesized and tested for their ability to cross external eukaryotic cell membranes and to enter the cytosol and nucleus in tissue cultures. The ODNs were labeled with high-specific-activity [3H]thymidine (> or = 100 Ci/mmol), or [ alpha-32P]ATP or [ gamma-32P]ATP (300-1000 Ci/mmol; 1 Ci = 37 GBq), and the label was either in the central portion of the molecule or at the 3' or 5' end. The cells employed were for the most part 3T6 murine fibroblasts, grown in monolayers, either semiconfluent or confluent, but some experiments were carried out with chicken embryo fibroblasts or human HeLa cells. Parallel wells in the same experiment were prepared for electron microscopy or for cell fractionation and radioactivity assays. Electron microscopic autoradiography indicated that ODNs cross the external cell membrane, traverse the cytosol, and begin to enter the cell nucleus within a few seconds to 5 min at 37 degrees C in Dulbecco's medium without added serum. After 30-60 min of incubation with ODNs, abundant silver grains were observed at or just inside the nuclear membrane or well distributed across the nucleus, particularly in association with euchromatin. There was a paucity of silver grains associated with nucleoli. Cell entry of oligomer was related to cell cycling events and was energy dependent. Degradation of oligomer to monomers, with reincorporation into DNA, does not appear to explain these results. No sequestration of labeled oligomer in cytoplasmic vesicles en route from the exterior of the cell to the nucleus was observed. The observations are more suggestive of internalization of oligonucleotide by a mechanism as yet unclear or, alternatively, by a caveolar, potocytotic mechanism rather than by endocytosis.

Plasma testosterone in the normal woman.

Abstract: Plasma testosterone concentration was determined in 57 samples from 9 normal women in 17 ovulatory menstrual cycles, using the double isotope method of Riondel et al. (3). The mean concentration was 0.054 μg/100 ml ±0.015 (SD) without subtraction of the water blank, which had a mean of 0.020 μg/100 ml ±0.005 (SD). The range of plasma testosterone in normal women is narrow. Values greater than 1 standard deviation above the mean were observed only during the ovulatory and luteal phases of the cycle. There was no correlation between plasma testosterone levels and urinary 17-ketosteroid excretion.

Metabolism of Δ 1(6) -Tetrahydro-cannabinol, an Active Marihuana Constituent

Abstract: A METHOD for preparing specifically tritiated (—)-Δ1(6)-tetrahydrocannabinol (I) was recently developed in our laboratories1. We would now like to report some of the results we have obtained in studying the metabolic fate of this material in the rabbit. Several publications dealing with the metabolism of cannabinoids have appeared2,3 in which other species were used, but none of the metabolites was identified. Moreover, in some cases the methods used to obtain the labelled cannabinoids would not yield radiochemically pure substances.

A microtubule-associated protein in the mitotic spindle and the interphase nucleus

Abstract: Accurate chromosome segregation during mitosis is contingent on the controlled polymerization and function of spindle microtubules. Assembly-promoting polypeptides that co-sediment with microtubules during cycles of polymerization in vitro are attractive candidates for regulators of the formation and function of the mitotic apparatus in vivo. However, previous work has shown that the major species of microtubule-associated proteins (MAPs) from mammalian brain or tissue culture cells are either not associated with the mitotic spindle1 or are associated with both mitotic and interphase cytoplasmic microtubules2–4. We have therefore sought a novel way to identify spindle regulatory factors. In the study reported here, monoclonal antibodies have been prepared against a MAP fraction from HeLa cells. One of the resulting hybridoma clones produces IgG that binds to a polypeptide of molecular weight ∼200,000. During cell division this antigen is associated with fibres in the mitotic apparatus, but in interphase it is located primarily in the nucleus. Surprisingly, the antigen is also detectable on the plasma membrane of circulating human erythrocytes. This spindle component is distinct from previously characterized MAPs and may represent a regulatory factor in the assembly and function of the mitotic apparatus.

Brain norepinephrine and serotonin levels following REM sleep deprivation in the rat

Abstract: Rats deprived of rapid eye movement (REM) sleep and stress controls showed no change in endogenous levels of norepinephrine and serotonin in the cerebral hemispheres, diencephalon, and brain stem. Following pargyline, the REM sleep deprived and stress control groups showed equally elevated norepinephrine and serotonin levels. These results suggest that enhanced biogenic amine synthesis following REM sleep deprivation is due to non specific stress rather than to loss of REM sleep per se.