Cytogenetic analysis of X-ray-induced chromosome aberrations in spontaneously leukaemic AKR mice.

The increased frequency of numerical and structural chromosomal aberrations in spontaneously leukaemic AKR mice, compared with the values of healthy control CBA/H-T6T6 mice, induced by X-irradiation, migh be connected with the predisposition to malignant growth, probably indirectly helping the virus activation, or acting together with the immune deficiency, by creating a weaker system that is more sensitive to carcinogenic agents.     

Mutagenic and carcinogenic actions of some polycyclic aromatic hydrocarbons]

The carcinogenic and mutagenic actions of benz(a)pyrene (BP) and its derivatives 6-methyl-, 6-formyl-, 6-chloro-, 6-hydroxy-, 6-acetoxy-, 6-methoxy- and 4(5)-methoxy-BP were studied in mice and bacteria Salmonella typhimurium TA-98 and TA-100, respectively. The potent carcinogenic agents BP, 6-methyl-, 6-formyl-BP proved also mutagenic in bacteria of both strains. Weak carcinogenic compounds (6-chloro-, 6-methoxy-, 4(5)-methoxy-BP) and noncarcinogenic ones (6-acetoxy-, 6-hydroxy-BP) either turned out nonmutagenic or mutagenic in one of two bacterial strains tested. The differences in carcinogenic and mutagenic actions of the substances under study are not relative to the rate of their oxidation in the enzymatic system.     

Effect of retinoids on carcinogen-induced mutagenesis in Salmonella tester strains

The ability of retinol (Rol) in altering mutation frequencies induced by 7 carcinogens was studied in Salmonella/microsome assay using 4 tester strains namely TA98, TA100, TA102 and TA1535. The 7 carcinogens used were aflatoxin B1 (AFB), cyclophosphamide (CPP), 3-methylcholanthrene (MCA), benzo[a]pyrene (BP), benz[a]anthracene (BA), 9,10-dimethyl-1,2-benz[a]anthracene (DMBA) and mitomycin C (MMC). As reported previously, Rol significantly reduced the number of His+ revertants induced by AFB. It also reduced mutations induced by CPP or MCA but not that by BP, BA, DMBA or MMC. The abilities of Rol, retinoic acid, retinyl acetate and a known inhibitor for certain P-450 isozymes, 7,8-benzoflavone (BF) in inhibiting mutations caused by AFB and BP were studied and compared. All the 3 retinoids caused significant reduction of AFB-induced His+ revertants in a dose-dependent manner, but there was no effect on BP-induced mutation. BF strongly inhibited both AFB- and BP-induced revertants. The possibility of retinoids in exerting their effects on mutagenesis of precarcinogens by inhibiting only certain forms of cytochrome P-450 enzymes is discussed.     

Chromosomal aberrations in foreign body tumorigenesis of mice

Sarcomas were induced in 107 male and female isogeneic CBA/H or CBA/H-T6 mice by subcutaneous implantation of double films of unplasticized vinylchloride-acetate copolymer, 15 x 22 x 0.2 mm in size. Tumors were grouped by chromosome number. G-banding was performed on chromosomes of (a) 12 sarcomas, (b) 6 specimens of preneoplastic cells derived from foreign body (FB)-reactive tissues at 4, 6, 9, and 16 months postimplantation, and (c) 11 sarcomas which developed from clonal lines of the preneoplastic cells studied. Karyological analyses lead to the following results and conclusions: (1) Various derangements in chromosome number occurred in preneoplastic cells during early FB reaction at the time of, and possibly in causal relation to carcinogenic initiation. (2) Structural abnormalities of specific chromosomes (insertions, translocations, transpositions, etc.) were found as stable cell markers only during late preneoplasia. They may thus contribute to advanced tumor progression. (3) Ploidy deviations of specific chromosomes (secondary to the early derangements in chromosome number) were most frequently seen in chromosomes 1, 6, 7, 13, 15, 18, and 19; however, these latter aberrations were unstable and inconsistent both in vivo and in vitro.     

Morphine-modulated mast cell migration and proliferation during early stages of zymosan-induced peritonitis in CBA mice

We have previously shown that supplementation of inflammation-inducing zymosan with a high dose ofmorphine inhibits peritoneal influx ofleukocytes in Swiss, C57C3H, Balb/c, and C57BL/6 strains but not in CBA mice. We have also reported that the different pattern of the response to morphine treatment might be, at least partially, due to the inter-strain differences in the peritoneal mast cell (P-MC) number (high in CBA mice versus other strains) and P-MC specific features (high sensitivity to degranulation upon morphine treatment in CBA mice). The aim of the present study was to investigate the mechanism of morphine action on P-MC in CBA mice. In particular, the effects of morphine on the proliferation and migration of P-MC in CBA mice with ongoing zymosan-induced peritonitis modulated by morphine were studied. Morphine alone acted as a strong chemoattractant for P-MC of CBA mice and this effect was opioid receptor-independent. Moreover, flow cytometric analysis showed that i.p. morphine injection induced significant proliferation of P-MC in CBA mice. Therefore, we conclude that the lack of anti-inflammatory effects of morphine during peritonitis in CBA mice might result not only from a unique sensitivity of CBA mast cells to morphine-induced degranulation but also from the fact that mast cell numbers increase at the inflammatory focus. The latter might be due to morphine-induced mast cell proliferation and/or migration.     

Immunomodulatory activities of a new pentapeptide (Bursopentin) from the chicken bursa of Fabricius

The bursa of Fabricius (BF) is a central immune organ in birds, and some peptides from chicken BF have demonstrated important immune functions. Here, a new 626.27 Da pentapeptide, Bursopentin (BP5, Cys-Lys-Arg-Val-Tyr) was isolated and purified by reverse-phase high-performance liquid chromatography. In this study, we examined the effects of BP5 on antigen-specific immune response in BALB/c mice sensitized with inactivated avian influenza virus (AIV) [A/Duck/Jiangsu/NJ08/05 (AIV H9N2 subtype)]. The results suggested that BP5 enhanced anti-hemagglutinin antibody (IgG, the isotypes IgG1 and IgG2a) production, induced both of Th1- (IL-2 and IFN-γ) and Th2-type (IL-4 and -10) cytokines, increased proliferations of splenic lymphocyte subsets CD4+ T cells (CD3+CD4+), CD8+ T cells (CD3+CD8+) and B cells, and enhanced cytotoxic T-lymphocyte activity of the activated splenocytes against NIH3T3 cells. The effects of BP5 on the proliferation of isolated T- and/or B-cell populations of BALB/c mice were assessed, and the data suggested that BP5 promoted spleen lymphocyte proliferation by activating B cells directly and T cells indirectly. Further analysis revealed that B-lymphocyte proliferation induced by BP5 is mediated by reactive oxygen species generated from thiol auto-oxidation of BP5. Furthermore, our data indicated that protein kinase C, mitogen-activated protein kinase, and nuclear factor kappa B are involved in the signal transductions during the BP5-induced B lymphocyte proliferation. This study indicates that BP5 could be a potential immunomodulator for future immuno-pharmacological use.     

Inhibition of hepatic aryl hydrocarbon hydroxylase by 3-methylcholanthrene, 7,8-benzoflavone and other inducers added in vitro.

A close correlation has been observed between the ability of aromatic polycyclic hydrocarbons and 7,8-benzoflavone (7,8-BF) to induce hepatic aryl hydrocarbon hydroxylase (AHH) in vivo and to inhibit the induced enzyme system in vitro. The activity of this mono-oxygenase was measured by the conversion of 14C-labeled dimethylbenz(a)anthracene (DMBA) or benzo(a)pyrene (BP) to water-soluble products by rat liver preparations (8000 X g supernatant). DMBA as substrate had the advantage over BP in giving a wider range of ethyl acetate-soluble metabolites and allowing the observation of changes in the pattern of these products following injection or addition of the inducing agents. This property was used to detect low concentration (0.1 muM) of polycyclic hydrocarbons which are strong AHH inducers and which may also be carcinogenic. The liver preparation was active for several months when stored at --20 degrees. A possible mechanism of action for the in vitro behaviour of polycyclic hydrocarbons and 7,8-BF towards AHH is proposed.     

Carcinogenicity and metabolic profiles of 6-substituted benzo[a]pyrene derivatives on mouse skin

The ability was tested of appropriate substituents of benzo[a]pyrene (BP) at C-6 to decrease or suppress the carcinogenic activity for these BP derivatives relative to the parent compound. 8-week-old female Swiss mice in 9 groups of 30 were treated on the back with 0.2 mumol of compound in acetone 4 times weekly for 20 weeks. The following compounds were administered: BP, 6-methylbenzo[a]pyrene (BP-6-CH3), 6-hydroxymethylbenzo[a]pyrene (BP-6-CH2OH), benzo[a]pyrene-6-carboxaldehyde (BP-6-CHO), benzo[a]pyrene-6-carboxylic acid, 6-methoxybenzo[a]pyrene, 6-acetoxybenzo[a]pyrene, 6-bromobenzo[a]pyrene, and 6-iodobenzo[a]pyrene. Two additional groups received BP or BP-6-CH3 twice weekly for 20 weeks at a total dose 25% of that above. In addition, the metabolism of selected 6-substituted BP derivatives was studied, using mouse skin homogenates in vitro and mouse skin in vivo. Only four compounds were carcinogenic; the order of potency was BP greater than BP-6-CH3 greater than BP-6-CH2OH and BP-6-CHO. The difference in carcinogenicity between BP-6-CH2OH and BP-6-CHO could not be assessed by this experiment. In a further tumorigenesis experiment the carcinogenicity of BP-6-CH2OH was compared to that of BP-6 CHO, BP-6-CH3 and 6-hydroxymethylbenzo[a]pyrere sulfate ester (BP-6-CH2OSO3Na) on mouse skin. 9-week-old female Swiss mice in groups of 28 were treated at three dose levels with 0.8, 0.2 and 0.05 mumol of compounds in dioxane--dimethyl sulfoxide (75 : 25) twice weekly for 40 weeks. After 40 experimental weeks BP-6-CH2OSO3Na proved to be a more potent carcinogen than BP-6-CH2OH, which, in turn was more active than BP-6-CHO. The greater carcinogenicity of BP-6-CH3 relative to BP-6-CH2OH and BP-6-CHO is confirmed, suggesting that BP-6-CH2OH is not a proximate carcinogenic metabolite for BP-6-CH3. Since BP-6-CHO is a weaker carcinogen than BP-6-CH2OH and is efficiently reduced metabolically to BP-6-CH2OH, the latter compound may be a common proximal carcinogenic metabolite. The stronger potency of BP-6-CH2OSO3Na, compared to its alcohol, suggests that an ester of BP-6-CH2OH might be the ultimate alkylating compound reacting with cellular nucleophiles.     

Evaluation of the BOD POD for estimating percent body fat in collegiate track and field female athletes: a comparison of four methods

This investigation examined the accuracy of the BOD POD on a group of Division I collegiate track and field female athletes (N = 30). Hydrostatic weighing (HW) was used as the gold standard method. Body density (Db) values obtained from the BOD POD (Db BP) were compared with those determined by HW (Db HW). Both Db values were converted to percent body fat (%BF) using the Siri equation for comparison. Percent body fat values obtained from the BOD POD (BF BP) were also compared with those obtained from dual-energy X-ray absorptiometry (DXA, BF DXA) and skinfold (SF, BF SF). The validity of the BOD POD was assessed using repeated-measures analysis of variance (ANOVA), and the relationship between the methods was examined through Pearson correlation. Average Db BP was 0.00890 g x cm(-3) lower (p < 0.05) than Db HW, resulting in a significant overestimation of %BF (p < 0.05) by the BOD POD. Values for BFDXA and BFBP also differed significantly (p < 0.05). On the other hand, BFSF and BF BP were not significantly different. The correlation between percent body fat values obtained from HW (BFHW) and BF BP was good (r = 0.88, SEE = 2.30) as well as between BF SF and BF BP (r = 0.85, SEE = 2.05). Conversely, the correlation between BFDXA and BF BP was poor (r = 0.25, SEE = 5.73). The strong correlation between BF BP and BF HW presented here suggests that the BOD POD has the potential to be used as a body composition analysis tool for female athletes. The advantages of the BOD POD over HW encourage further investigation of this instrument. However, the fact that the BOD POD and SF results did not differ significantly might suggest that the SF could be used in its place until a better rate of accuracy for this instrument is established.     

Involvement of the serotonergic cerebral system in microwave-induced analgesia in mice of different genotypes

Under conditions of the formalin test, we studied changes in the level of analgesia induced by the action of low-intensity microwaves on the antinociceptive acupuncture point (AP) E36 in mice of strains CBA/CaLac (CBA) and C57BL/6j (C57) and in albino mongrel mice. Measurements were performed under control conditions and with experimentally induced decrease in the serotonin level in the brain (by injections of DL-parachlorophenylalanine, p-CPA). In the latter cases, the duration of the pain behavioral reaction increased despite irradiation of the AP E36. In mongrel, CBA, and C57 mice, the intensity of pain manifestations was 114.4, 29.0, and 21.1% greater, respectively, than in mice of these groups with no injections of p-CPA. These facts show that the serotonergic brain system is profoundly involved in the formation of analgesia after irradiation of the AP by low-intensity microwaves, and this involvement significantly depends on the genotype of the animals. Neirofiziologiya/Neurophysiology, Vol. 38, Nos. 5/6, pp. 495–497, September–December, 2006.     

Effect of delta sleep-inducing peptide, anticonvulsant preparations and nicotinamide on generalized seizure activity

The influence of delta-sleep inducing peptide (DSIP) upon seizures induced by corazol, bicuculline, picrotoxin, strychnine, thiosemicarbazide were investigated in experiments on F1(CBA X C57 BL/6) mice. It was shown that DSIP increased the latency of first seizure manifestation which were induced by corazol, bicuculline and picrotoxin and also resulted in a suppression of seizure severity of corazol and bicuculline induced seizures. Anticonvulsant action of DSIP was evident under the condition of the mild severity seizures development. The effect of DSIP was mostly pronounced in range of its doses from 10 to 100 mcg/kg. DSIP when combined with phenobarbital, carbamazepine, diphenylhydantoin or nicotinamide enhanced the antiepileptic effects of these anticonvulsant drugs.     

Suppressors of the graft vs graft reaction in tolerance to alloantigens

Immune response and suppressor cell activity of CBA (H-2k) mice made tolerant to allogeneic C57B1/6 (H-2b) heart graft were studied in graft-versus-graft reaction (GvGR). Intact CBA spleen cells inhibited response of (CBA X C57B1/6)F1 cells to antigenic stimulus (sheep red blood cells--SRBC), when injected together into lethally irradiated (CBA X C57B1/6)F1 mice. Spleen cells of tolerant mice were unable to decrease immune response of (CBA X C57B1/6F1 lymphocytes to SRBC and suppressed specifically the inhibition induced by intact CBA spleen cells. Spleen cells from tolerant mice were also capable of suppressing GvGR induced by CBA lymphocytes immune to C57B1/6 cells. Pretreatment of tolerant spleen cells with rabbit antithymocyte globulin and complement before adoptive transfer diminished markedly the suppression. The results obtained in the study suggest that suppression of transplantation immunity in this model is mostly due to T suppressor cells.     

Induction,modification and inhibition of rat liver microsomal benzo(a)pyrene hydroxylase; Correlation with the S-9-mediated mutagenicity of benzo(a)pyrene

The effects of various pretreatments $\text{in vivo}$ (3MC, PB, 2 and 4FAA) and of various inhibitors $\text{in vitro}$ (7,8 BF, SKF525A and MN ^R) on the activity of rat liver microsomal BP hydroxylase were analyzed and correlated with the S-9 mediated mutagenicity of BP. 3MC is the only treatment which both induces and modifies the hydroxylase activity; it also specifically increases the enzyme mediated mutagenicity. Miconazole ^R which inhibits all the tested microsomal preparations, also reduces the mutagenicity mediated by all the S-9 preparations whereas the inhibitory effects of 7,8 BF and SKF525A are limited respectively to enzyme preparations from 3MC induced and control or PB treated rats.     

Carcinogenesis: Mechanism and Criteria of Carcinogenic Activity

The pattern of carcinogenic action is described for locally acting as well as for remotely acting carcinogens. Whether applied locally, injected subcutaneously or given by mouth, aromatic polycyclic hydrocarbons are potentially carcinogenic for all tissues, whereas other known locally acting carcinogens have no such wide action. Solubility and diffusibility of the compound should be considered, but the question of localization of induced tumours is a problem of dose-response relationship.The method for evaluating carcinogenic action of a compound is based on the readiness with which the tumour is induced, and not in terms of the intensity of the response. The average latent period and the percentage of tumour yield are the two measures used. Since, at the present time, no chemical tests are available to determine whether a substance is carcinogenic, one must resort to biological methods of testing carcinogenic activity.The value of a long-term test for carcinogenesis, under a given set of rigidly controlled conditions, is emphasized, since there are so many variables which singly or in combination may alter the final effect of a given substance.     

Mechanism of vasoconstriction in the rat's tail when warmed locally.

The vascular response of the tail to local warming was investigated in urethan-anesthetized rats whose colonic temperature was maintained at 39.5 degrees C with an intravenous thermode at an ambient temperature of 23 degrees C. The tail, covered with thin latex tubing, was immersed in temperature-controlled water initially kept at 35 degrees C. The tail was warmed by raising the water bath temperature from 35 to 44 degrees C at a constant rate. Tail blood flow (BF), mean arterial blood pressure (BP), and tail skin temperature (Tsk) were measured before and during the local warming. Tail vascular conductance (VC) was computed as 100 x tail BF/BP. When Tsk exceeded 37 degrees C, tail BF and VC significantly decreased from the levels at Tsk of 35 degrees C, and significant reductions in tail BF and VC occurred until Tsk reached 42 degrees C. Surgical deafferentation of the tail, chemical sympathectomy with 6-hydroxydopamine (100 mg/kg), and alpha-blockade with phentolamine (7 or 40.1-45.5 mg/kg) or phenoxybenzamine (5 mg/kg) failed to stop the decrease in tail BF and VC during the local warming. These results suggest that a reflex via the central nervous system and the alpha-adrenergic sympathetic nervous system is not indispensable for heat-induced vasoconstriction (HIVC). It is therefore assumed that, at least in the rat's tail, HIVC predominantly originates from a local vascular response to high temperature.     

Mutagenic activity of selected aromatic amines and polycyclic hydrocarbons in Drosophila melanogaster

With the use of a series of wild-type and repair-deficient strains and appropriate application procedures, it is possible to demonstrate that carcinogenic aromatic amines and polycyclic hydrocarbons are mutagens in Drosophila. We have shown evidence that AAF, N-OH-AAF, AcO-AAF, BP, DAS and DMBA produce recessive lethals when fed to or injected into adult males. Mutagenic activity was also observed when male larvae were exposed to AAF, BP, DMBA, 3-MC or NA. DA was not mutagenic in the recessive lethal assay under the conditions of the test. DMBA can now be considered as a potent mutagen for Drosophila, although demonstration of its activity depends upon the choice of the treatment procedure and the strain selected. One of the questions concerning the action of aromatic amines and polycyclic hydrocarbons is how their genetic effectiveness in Drosophila can be enhanced. The observation that none of several enzyme inducers (PB, BF, AC, 3-MC) increased their mutagenicity may be interpreted in terms of a more efficient metabolic activation or deactivation. This assumes that active metabolite(s) did not reach the testis in doses sufficient for mutation induction. It also appears that, since the problems pertaining to mutagenicity in Drosophila of aromatic hydrocarbons are obviously a matter of metabolism, the use of repair-deficient strains is no longer an attractive proposal for their elucidation. The present investigation shows that, with weak mutagens, usage of strains mei-9Li or y mei-9a mei-4lD5 does not improve the sensitivity of the recessive lethal method or the test for chromosomal loss. As an alternative, in our opinion more attention should be devoted to possible differences in metabolism between somatic and gonadal tissue. We feel strongly that somatic assay systems might be particularly valuable as a complement to recessive lethal tests on the germ line.     

Relationship between T- and B-lymphocyte cooperation and their syngeneity]

Cooperation efficiency of (CBA x C57BL/6) F1 thymocytes and CBA bone marrow cells in immune response to SRBC was compared with the syngenic combination of the same cells. Selectivity of interaction of the T- and B-lymphocytes of different origin was studied in incomplete cyclophosphamines (CBA x C57BL/6) leads to CBA chimerae, where donors were primed with SRBC and the recipients were either intact or tolerant to the given antigen. F1 T-cells proved to interact with the CAB-B-cells 10-15 times less effectively than with the syngenic B-cells. It is suggested that similarity between the antigenic structure of the cell membrane of the T- and B-lymphocytes, aiding their physical contact, increased the action efficiency of the T-mediator on the B-cell.     

Regulatory T cell subpopulations in pregnancy. I. Evidence for suppressive activity of the early phase of MLR.

Previous in vivo experiments have provided evidence of suppressive activity induced by multiple allogeneic pregnancies. The reactivity of maternal spleen cells toward paternal strain alloantigens was investigated by use of MLR microculture technique. A study of the kinetics of the MLR showed an early peak of reactivity (48-hr culture) followed by a decline leading to a decreased reactivity by 96 hr when spleen cells from allogeneically pregnant mice were compared to those of virgin or even isogeneically pregnant mice, suggesting the possible action of MLR regulatory cells. A strong suppression of a H-2k (CBA) anti-H-2a (A/J) or anti-H-2d (C57BL/Ks) MLR was observed when mitomycin-treated spleen cells from CBA mice multiparous by A/J or C57BL/Ks (but not CBA) males were added to the culture. This suppression was abolished by treating the regulatory cell population with anti-theta serum plus complement or replacing the 1% normal mouse serum in the medium by a proper antiidiotypic mouse serum.     

Mechanism of the intensification of the immune response to Staphylococcus in mice after the transplantation of primed donor splenocytes

Experiments on CBA, C57Bl/6 mice and (CBA X X C57Bl/6)F1 hybrids were made to study the mechanism of stimulation of the immune response to staphylococci after injection of primed splenocytes. The stimulating action of immune splenocytes was reversed after their in-vitro treatment with anti-immunoglobulin serum and complement. The stimulant effect was also seen in a semi-allogeneic system (adoptive transfer of CBA mice immune cells to (CBA X C57Bl/6)F1 recipients). Preincubation of splenocytes with CBA-anti-C57Bl/6-serum and complement prior to demonstration of antibody-forming cells did not influence their number in the spleen of hybrid recipients injected with immune cells carrying parent genotype but decreased this indicator of the immune response in control mice. It is concluded that stimulation of the immune response to staphylococci after transplantation of primed splenocytes is due to the anamnestic response of donor's cells repeatedly stimulated by antigen in the recipient's host.     

Study on the biosynthesis of dolichol in yeast: recognition of the prenyl chain length in polyprenol reduction

We synthesized three water-soluble biotin-tagged compounds with different prenyl chain lengths, biotinylated farnesal (BF), biotinylated C(55)-polyprenal (BP55), and biotinylated C(80)-polyprenal (BP80), and examined their effects on in vitro dolichol synthesis from farnesyl diphosphate. BF and BP55 did not affect the dolichol synthesis, whereas BP80 inhibited the reduction pathway from polyprenol to dolichol, accompanied by a decrease in the entire polyprenol and dolichol synthesis. Comparison of BP80 with eighteen detergents, including Triton X-100, CHAPS, octylglucoside, deoxycholate, and Tween 80, revealed the specific effect of BP80 on the reduction pathway. On SDS-polyacrylamide gel electrophoresis, BP80 was detected in an associated form with a 50 kDa protein. These results suggest that the reduction of polyprenol to dolichol in the dolichol biosynthetic pathway proceeds with the recognition of the polyprenol chain length by a 50 kDa protein.