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Biomedical subjects

J H Russell

Publications and source records attributed to J H Russell.

At least 91 records · Page 5Linked to original sources
PubMed1982

Immunosuppressive agents prevent guanethidine-induced destruction of rat sympathetic neurons.

Chronic administration of guanethidine to rats causes destruction of peripheral sympathetic neurons. Neuronal destruction, characterized morphologically by small cell infiltration and the reduction in the number of neurons within sympathetic ganglia, and biochemically by a marked reduction in tyrosine hydroxylase activity, occurred reproducibly by day 7 of treatment following 5 daily injections of 50 mg/kg guanethidine sulfate. Several observations in the literature suggested that guanethidine-induced destruction may occur by an immunologically mediated mechanism. Experiments were therefore designed to test the effects of immunosuppressive agents on guanethidine sympathectomy. A single exposure to either gamma-irradiation or cyclophosphamide, administered 8 h prior to the initiation of guanethidine treatment, protected against guanethidine-induced destruction in a dose-related manner and was virtually complete with either 900 rads of irradiation or with 100 or 150 mg/kg of cyclophosphamide. Cyclophosphamide afforded complete protection only if administered immediately prior to guanethidine treatment suggesting that it was acting during the proliferative phase of an immune response rather than non-specifically. Pretreatment with either irradiation or cyclophosphamide had no effect on the sympathectomy produced by treatment with either 6-hydroxydopamine or antibodies to nerve growth factor, nor did it prevent the accumulation of guanethidine within the sympathetic ganglia. Concurrent treatment with either azathioprine or dexamethazone also provided partial protection against guanethidine sympathectomy. These results strongly suggest that the destruction of sympathetic neurons induced by guanethidine occurs by an immunologically mediated mechanism.

Animals↗
PubMed1982

Mechanisms of immune lysis. III. Characterization of the nature and kinetics of the cytotoxic T lymphocyte-induced nuclear lesion in the target.

The experiments reported here demonstrate that the event leading to CTL-induced nuclear disintegration is kinetically similar (t1/2 = 3.1 +/- 0.8 min) to that reported for CTL-induced plasma membrane disintegration as measured by 51Cr release. However, the expression of the lethal event by detergent-soluble 125I release occurs so rapidly that the time between the initiation of the lesion and its expression is 15 min instead of the 90 to 120 min time course for plasma membrane disintegration measured by 51Cr release. In addition, we have demonstrated that the rapid 125IUdR release characteristic of CTL-lysed targets is specific for the nucleus within the target cell itself. Isolated nuclei cultured with effectors and targets during a lytic reaction are not rapidly damaged by the lytic process. Finally, we have characterized the CTL-induced nuclear lesion as a degradative process occurring within the plasma membrane of the target cell. The significance of these events and their relationship to the CTL's role in the host defense system is discussed.

Animals↗
PubMed1981

The role of monovalent cations in the interaction between the cytotoxic T lymphocyte and its target.

Evidence is provided for the participation of monovalent cations in both the binding and lytic phases of the lytic cycle. There appears to be one sodium requirement in the cytotoxic T lymphocyte-target binding event (effective dose 50 approximately 35 mM) and possibly another sodium requirement in the delivery of the lethal hit (ED50 less than 7 mM). Potassium can replace sodium in the binding event but antagonizes the lethal hit phase (inhibitory dose 50 approximately 110 mM). Lithium antagonizes the binding event (ID50 approximately 15 mM).

Animals↗
PubMed1981

Genetic control of cross-reactive cytotoxic T-lymphocyte responses to a BALB/c tumor.

Using a segregation analysis we have determined that the cross-reactive response to the DBA/2 tumor P815 by CTL from BALB/c mice immunized with a BALB/c plasmacytoma (MOPC-167) is controlled by a single gene. The gene responsible is closely linked to the dilute coat color locus on chromosome 9. In contrast, the cross-reactive response to the DBA/2 tumor L5178Y by DBA/2 anti-MOPC-167 CTL appears to be controlled by two or more genes.

Animals↗
PubMed1980

Mechanisms of immune lysis. I. Physiological distinction between target cell death mediated by cytotoxic T lymphocytes and antibody plus complement.

The pattern of progressive release of cytosolic (52Cr) and nuclear (125IUdR) labels from normal or tumor cells being lysed by CTL is strikingly different from the pattern observed when similar cells are lysed by Ab + C or hypotonic shock. We propose that these differences reflect physiologic differences in the lytic events associated with Ab + C- and CTL-mediated cell death.

Animals↗
PubMed1980

Mechanisms of immune lysis. II. CTL-induced nuclear disintegration of the target begins within minutes of cell contact.

Within minutes of CTL-target interaction, the intracellular disintegration of the target cell nucleus begins. This nuclear event satisfies the ionic and temperature requirements that have been described by others as important in CTL-mediated lysis. Such nuclear disintegration does not occur in Ab+C-lysed targets. Thus the target cell nucleus appears to signal a primary event in CTL-mediated lysis that distinguishes the CTL lytic mechanism from that of Ab+C.

Animals↗
PubMed1979

Cyclical changes in susceptibility of a myeloma tumor (LPC-1) to immune destruction. I. Changes in reactivity with cytotoxic T lymphocytes and anti-H-2d sera.

One of six transplantable ascites tumors of BALB/c mice was found to become periodically resistant to cytotoxic T lymphocytes (CTL). About 12 days after LPC-1, a myeloma tumor, was transplanted it became resistant to lysis by allogenic CTL (anti-H-2d) and by CTL directed to trinitrophenyl groups or minor histocompatibility antigens. Susceptibility to lysis by all of these CTL was regained within 2 to 4 days after transfer of resistant cells to a fresh BALB/c host. These changes were recurrent: in each transplantation cycle the early LPC-1 cells were susceptible and the late cells were resistant to CTL. Analyses with antisera (B10 anti-B10.D2) showed that the serologically recognized products of the H-2d haplotype were reduced about 10-fold on the LPC-1 cells that were resistant to CTL.

Animals↗
PubMed1978

Periodic loss of reactivity of a myeloma tumor with cytotoxic thymus-derived lymphocytes.

During each transplantation passage of a line of mouse myeloma tumor MOPC-315 through syngeneic (BALB/c) hosts, the tumor cells lose reactivity with cytotoxic thymus-derived lymphocytes directed against products of the BALB/c major histocompatibility complex (H-2d) and regain reactivity on transfer to fresh hosts. In contrast to this cyclical change, the tumor cells remain uniformly reactive with anti-H-2d alloantisera throughout the transplantation cycle.

Animals↗
PubMed1975

The structure of rat proalbumin.

The structure of rat proalbumin, a liver precursor to rat serum albumin, has been determined to consist of the hexapeptide Arg-Gly-Val-Phe-Arg-Arg attached to the NH2 terminus of the polypeptide chain of rat serum albumin. Edman degradation of a proalbumin preparation for 14 rounds gave the major sequence Arg-Gly-Val-Phe-Arg-Arg-Glu-Ala-His-Lys-Ser-Glu-Ile-Ala. A comparison of cyanogen bromide fragments suggests that these two proteins differ only in this respect. On treatment with cyanogen bromide, these proteins gave three classes of peptides with molecular weights of 30,000, 10,000, and smaller than or equal to 5,000. A combination of gel filtration, electrofocusing, and ion exchange established that these peptides were indistinguishable, with exception of those of 10,000 molecular weight. By amino acid and sequence analyses this fraction from rat serum albumin was found to be the NH2-terminal fragment. Radiochemical amino acid and sequence analyses show that the NH2-terminal hexapeptide is the major fragment released from proalbumin by limited tryptic hydrolysis. The protein that remains cannot be distinguished from rat serum albumin.

Amino Acid Sequence↗
PubMed1975

Photomanipulation of phytochrome in lettuce seeds.

Seeds of lettuce (Lactuca sativa L. cv. Grand Rapids) were imbibed and given either short irradiation with red or far red light prior to drying or dried under continuous red or far red light. Seeds treated with either short or continuous red germinate in darkness, whereas seeds treated with either short or continuous far red require a short exposure to red light, after a period of imbibition, to stimulate germination. Irradiation of dry red seeds with far red light immediately before sowing results in a marked inhibition of germination. This result was predicted since far red-absorbing form phytochrome can be photoconverted to the intermediate P650 (absorbance maximum 650 nm) in freeze-dried tissue. A similar far red treatment to continuous red seeds is less effective and it is concluded that in these seeds a proportion of total phytochrome is blocked as intermediates between red-absorbing and far red-absorbing form phytochrome, which only form the far red-absorbing form of phytochrome on imbibition. The inhibition of dry short red seeds by far red light can be reversed by an irradiation with short red light given immediately before sowing, confirming that P650 can be photoconverted back to the far red-absorbing form of phytochrome. The results are discussed in relation to seed maturation (dehydration) on the parent plant.

Journal Article↗