N-(sulfonamido)alkyl[tetrahydro-1H-benzo[e]indol-2-yl]amines: potent antagonists of human neuropeptide Y Y5 receptor

[3a,4,5,9b-Tetrahydro-1H-benzo[e]indol-2-yl]amines were prepared via reductive amination and concomitant cyclization of alpha-cyanomethyl-beta-aminotetralins. N-acylation with omega-sulfonamido-carboxylic acids and subsequent reduction afforded a series of N-(sulfonamido)alkyl[tetrahydro-1H-benzo[e]indol-2-yl]amines, which bound to the human neuropeptide Y Y5 receptor with nanomolar affinity.     

The effect of sequential irradiation with X-rays and fast neutrons on the survival of V79 Chinese hamster cells

V79 Chinese hamster cells have been exposed to X-rays or fast neutrons or to the two radiations given sequentially. Cells exposed to a priming dose of X-rays and then exposed immediately to a series of neutron doses regard the X-ray dose as equivalent to a neutron dose giving the same surviving fraction (iso-effective). If the cells are exposed to a neutron dose followed by X-rays the resulting survival is higher than would be obtained if the primary dose had been an iso-effective X-ray dose. However, it is lower than would be expected if the two radiations acted independently. The results imply that there is interaction between the damage caused by X-rays and fast neutrons. If the two radiations are given 3 hours apart they act independently.     

Survival of V79 cells following simultaneous irradiation with X-rays and neutrons in air or hypoxia

V79 Chinese hamster cells have been irradiated with X-rays and neutrons given simultaneously. The oxygen enhancement ratio and r.b.e. were measured as a function of the proportion of the dose due to the neutrons, which varied from 0 to 100 per cent. These were compared with the values calculated assuming the two types of radiation act independently, following an approach suggested by Curtis. The o.e.r. was less than the predicted value when the neutrons contributed less than about 40 per cent of the total dose. The r.b.e. also did not vary as predicted on the basis of independent action. The 'oxygen gain factor' reached half its maximum value when the proportion of the dose due to neutrons was only about 27 per cent. The results imply that there may be interaction between the damage caused by X-rays and neutrons and that beams having only 20 to 30 per cent of their dose due to high l.e.t. radiation, could be of therapeutic benefit.     

The labelling index of human and mouse tumours assessed by bromodeoxyuridine staining in vitro and in vivo and flow cytometry

Bromodeoxyuridine (BrdUrd) incorporation and flow cytometry were used to measure human tumour kinetic parameters in vitro and in vivo. The technique was validated by comparison of labelling index estimates of mouse tumours in vivo and in vitro using BrdUrd and flow cytometry with tritiated thymidine (3HdThd) autoradiography. Similar labelling indices were obtained with both in vivo and in vitro incorporation into DNA of the two different precursors. Measurements of human tumour labelling indices were similar following in vitro incubation with either BrdUrd or 3HdThd. The use of BrdUrd allowed the visualization of a population of S-phase cells that did not appear to incorporate BrdUrd or 3HdThd. The human tumour labelling indices obtained with BrdUrd incorporation were similar to previously reported values using autoradiography studies. Preliminary studies demonstrated that significant human tumour labelling could be achieved with an intravenous injection of 500 mg BrdUrd.     

A method to measure the duration of DNA synthesis and the potential doubling time from a single sample

A method is described whereby the DNA synthesis time, Ts, can be calculated using data of a single sample of cells taken several hours after labelling with bromodeoxyuridine (BrdUrd). The method involves a simple calculation using flow cytometry data of BrdUrd incorporation (green fluorescence, FITC-labelled anti-BrdUrd-DNA antibody) and total DNA content (red fluorescence, propidium iodide). The movement of BrdUrd-labelled cells through the S phase can be quantified by measuring their mean red fluorescence relative to that of G1 and G2 cells. Assuming the movement of the labelled cells toward G2 is linear with time, Ts can be calculated by measuring their relative movement at any one time. The method was tested on cells in vitro and on bone marrow and tumor cells in vivo. Reasonable agreement was seen with published estimates of Ts for these tissues.     

Human cardiac myosin heavy chain genes and their linkage in the genome.

Human myosin heavy chains are encoded by a multigene family consisting of at least 10 members. A gene-specific oligonucleotide has been used to isolate the human beta myosin heavy chain gene from a group of twelve nonoverlapping genomic clones. We have shown that this gene (which is expressed in both cardiac and skeletal muscle) is located 3.6kb upstream of the alpha cardiac myosin gene. We find that DNA sequences located upstream of rat and human alpha cardiac myosin heavy chain genes are very homologous over a 300bp region. Analogous regions of two other myosin genes expressed in different muscles (cardiac and skeletal) show no such homology to each other. While a human skeletal muscle myosin heavy chain gene cluster is located on chromosome 17, we show that the beta and alpha human cardiac myosin heavy chain genes are located on chromosome 14.