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C Roth

Publications and source records attributed to C Roth.

13 recordsLinked to original sources
PubMed1992

Inhibition of tumor growth by histoincompatible cells expressing interleukin-2.

Murine tumor cells engineered to express IL-2 have been shown to be rejected by the syngeneic host, which is then protected against a subsequent tumorigenic challenge. To assess whether IL-2 has to be produced by the tumor cells themselves, or whether its local delivery would be sufficient to promote such beneficial effects, the syngeneic tumor cells were co-inoculated with allogeneic or xenogeneic cells secreting IL-2, selected after gene transfection. In several murine systems, it was observed that this is an efficient approach for controlling the growth of the syngeneic tumor. However, animals which rejected the tumor were not protected against a subsequent challenge. Several lines of evidence indicate that NK cells play a major role in tumor rejection induced by the IL-2 expressing histoincompatible vector cells. Thus, while local delivery of IL-2 in the vicinity of a tumor might not be sufficient to promote a systemic long-term specific antitumor immune response, it can control the growth of the primary syngeneic tumor. These experiments demonstrate the feasibility of using genetically engineered histoincompatible cells (which are rejected by the host's immune system) as a transient delivery system in vivo.

Animals↗
PubMed1992

Psychiatric effects of exposure to suicide among the friends and acquaintances of adolescent suicide victims.

The friends and acquaintances (N = 58) of 10 adolescent suicide victims were interviewed 6 months after the death of the victims, and the rates of psychiatric disorders that had onset after the death were compared with the 6-month incidence of psychopathology in 58 demographically and psychiatrically matched unexposed controls. The exposed group showed higher rates of any new onset major depressive disorder, but the rate of incident suicide attempts was the same in both groups. The median onset of incident depression among the exposed group was within the first month after exposure, and the majority of those exposed youth with incident depression were still depressed at interview 6 months after the death. Adolescent friends and acquaintances of suicide victims experience considerable psychiatric morbidity subsequent to exposure to suicide, most consistent with pathological grief.

Adolescent↗
PubMed1992

[Potentiation of the antitumoral effect of electrochemotherapy by immunotherapy with allogeneic cells producing interleukin 2].

Electrochemotherapy (ECT) is a new antitumour treatment which consists of delivering electric pulses to the tumour a few minutes after an intravenous injection of bleomycin. The antitumour efficacy of ECT is increased by local injections of interleukin 2 (IL2) in the oedema which appears at the site of the treated tumours. We have shown that tumour cells inoculated in syngeneic mice are rejected if IL2 secreting allo- or xenogeneic cells are co-injected with tumour cells. We report here the large increase of ECT therapeutical efficacy when allogeneic cells secreting IL2 are injected into the peri-tumoural oedema.

Animals↗
PubMed1975

Effect of methylxanthines on alloxan inhibition of insulin release.

Isloated rat islets were maintained in vitro in a perifusion system, exposed to alloxan (20 mg/100 ml) for 5 minutes in the presence of agents which affect cAMP metabolism and subsequently stimulated with glucose. The rate of insulin secretion was monitored throughout the period of perifusion. Exposure to alloxan alone produces complete inhibition of glucose-induced insulin release [18] whereas concomitant exposure to carreine and theophylline for this brief interval provided almost complete protection of the islets from the inhibitory action of alloxan. Glucagon, cAMP and CBcAMP did not protect the islets form alloxan. Pre-treatment of the islets with either theophylline or glucagon and DBcAMP did not provide protection. These findings indicate that the protective action of theophylline and carreine against alloxan is unrelated to the effect of these agents on cAMP metabolism in the beta cell.

Alloxan↗
PubMed1975

Effect of alloxan on permeability and hexose transport in rat pancreatic islets.

The in vitro effect of alloxan exposure on the permeability of collagenase isolated rat pancreatic islets to sucrose, D-mannitol, and L-glucose has been investigated. Determination of changes in cell volume with a non-wash double label isotope procedure indicates that alloxan treatment exerts no measurable effect on permeability to sucrose, D-mannitol, or L-glucose as compared to nonalloxan-treated islets. In addition, neither prior exposure nor the concomitant presence of alloxan alters the rate of D-glucose or 3-0-methyl-D-glucose transport into rat pancreatic islets. It is concluded that the in vitro effect of alloxan on abolishing glucose-induced insulin release in isolated rat pancreatic islets does not appear to be the result of permeability changes to small organic molecules or alteration in the transport of D-glucose into the beta-cell.

Alloxan↗
PubMed1975

Defense mechanisms in men and women alcoholics.

The responses of men and women alcoholics to the Defense Mechanism Inventory showed that the women scored significantly higher in "turning against self" and the men in "turning against others." Although such differences may underlie reported sex differences in the incidence of depression and sociopathic personality disorder, they have also been found in studies of nonalcoholics and psychiatric outpatients.

Adult↗
PubMedDate not supplied

Antigenic variation in Trypanosoma equiperdum.

Trypanosoma equiperdum is an African trypanosome that causes dourine in horses. Like the other African trypanosomes, T. equiperdum escapes elimination by the immune system of its host by using an elaborate system of antigenic variant. The trypanosomes are covered by a coat consisting of a single protein called the variable surface glycoprotein (VSG) that acts as the major trypanosome immunogen. As the host responds to one VSG, trypanosomes covered with another VSG become dominant. There is a loose order of appearance of these VSG during the infection. The factors that affect the timing of VSG expression and the effective size of the VSG repertoire in T. equiperdum are reviewed. The VSG genes are generally activated by a process of duplicative transposition involving the duplication of a silent VSG gene and inserting a copy of the gene into an expression site. The order of VSG expression is related to the amount of homology between the silent gene and the expression site. The genes expressed late in infection lack extensive homology with the expression site and depend on homology with the gene in the expression site. The genes coding for VSG expressed late in infection are hybrid genes because of this mode of transfer. This transfer mechanism allows the trypanosome to create complex VSG genes from parts of several different silent genes that are each pseudogenes. Additionally, data are presented showing that only a limited portion of the VSG is actually seen by the host immune system. These factors indicate that the effective VSG repertoire is greater than the number of VSG genes in the trypanosome genome.

Animals↗