Female CBA Mice Research Articles

Sex differences in acute delta-9-tetrahydrocannabinol (Δ9-THC) response and tolerance as a function of mouse strain.

Cannabinoids are increasingly used to alleviate pain; however, tolerance to their antinociceptive effects, including those of delta-9-tetrahydrocannabinol (Δ9-THC), may limit their therapeutic utility. With more women than men using medical cannabis for pain relief, it is crucial to understand how sex influences cannabinoid-mediated antinociception and tolerance. Though studies in rats consistently find females are more sensitive to the acute antinociceptive effects of cannabinoids, our work with mice consistently finds the converse. The present study examined whether our observed sex differences in Δ9-THC-induced antinociception and tolerance are consistent across multiple mouse strains or are strain-dependent. Male and female C57BL/6J (B6), DBA/2, AKR, and CBA/J mice were assessed for differences in acute Δ9-THC-induced antinociception and hypothermia prior to and following seven days of once-daily Δ9-THC administration. Consistent with our previous findings, male B6 mice were more sensitive to the acute antinociceptive effects of Δ9-THC than female littermates, an effect which dissipated with age. B6 males had decreased cannabinoid expression in the PAG compared to females. While DBA and CBA female mice showed increased Δ9-THC-antinociception compared to male littermates at 30 and 10 mg/kg Δ9-THC, respectively, these differences were less pronounced at higher doses, revealing that dose of Δ9-THC may also be important. Overall, CBA mice were more sensitive to Δ9-THC-induced antinociception while AKR mice were less responsive. These studies highlight the therapeutic potential of Δ9-THC in pain management and underscore the importance of considering not only Δ9-THC dose as a function of sex, but potentially genetic differences when evaluating their clinical utility.

Effect of 5-hydroxypyrimidine derivatives on tumor growth and cytokine concentration in blood serum of female CBA mice with cervical cancer (RSHM-5)

The effects of intraperitoneal administration of SNK-411 (2-isobutyl-4,6-dimethyl-5-hydroxypyrimidine) in a dose of 25 mg/kg (the total dose of 350 mg/kg) and SNK-578 (hydrochloride of 2-isobutyl-4,6-dimethyl-5- hydroxypyrimidine) in a dose of 10 mg/kg (the total dose of 140 mg/kg) on tumor growth and concentration of cytokines in the blood serum were studied in female CBA mice. Substances were administrated from the 2nd to 15th days of tumor development. Tumor growth inhibition (TGI) and serum cytokine level were studied on the 7th day after the end of compounds administration (21st day of tumor growth). In intact control group (n=10) median tumor mass was 1255 mg. TGI in the group of animals treated with SNK-411 was 47%; in the group of mice treated with SNK-578 TGI was 87%, tumor mass demonstrated 7.4-fold reduction. Serum concentrations of cytokines (IL-6, IL-10, IL-17A and IFN-γ) in tumor-bearing group of mice were higher versus the intact control group by 229%, 40%, 60% and 81%, respectively. Highly active SNK-578 decreased concentrations of prooncogenic IL-10, IL-17A and proinflammatory IL-6, by 61%, 70% and 29% as compared to tumor-bearing control group. SNK-411 decreased concentrations of prooncogenic IL-10 and IL-17A by 48% and 60%, respectively, and did not affect concentration of IL-6. Taking into consideration that IL-6 participates in autoimmune reactions, we can assume that the immune control is one of the crucial mechanisms of antitumor effect of SNK-578. All results are statistically significant.

Proliferative Activity of Mouse Splenocytes in Physiological Pregnancy and in Models of Spontaneous and Muramylpeptide-Dependent Abortions.

Spontaneous proliferative activity of splenocytes in female CBA mice and the response of these cells to antigens of allogeneic male BALB/c and DBA/2 mice in a mixed splenocyte culture were evaluated by 3H-thymidine incorporation in different pregnancy models. ♀CBA×♂BALB/c mating was used for modeling physiological pregnancy. Spontaneous abortions were reproduced by abortion-prone ♀CBA×♂DBA/2 mating. In order to simulate immunostimulant-induced and immunostimulant-potentiated abortions, 0.83 mg/kg muramyl dipeptide β-heptylglycoside was intraperitoneally injected to CBA females mated with BALB/c or DBA/2 males, respectively, on gestation days 5 and 7. The increase in the rate of embryo resorption in the models of spontaneous, induced, and potentiated abortions occurred against the background of an increase in the level of spontaneous proliferation of splenocytes and a decrease in their reactivity to paternal antigens on gestation day 9.

Early protection against influenza by pandemic live attenuated influenza vaccines

Live attenuated cold-adapted (ca) influenza vaccine (LAIV) is an effective tool for the control of influenza, most likely due to their ability to induce both humoral and cellular immune responses, easy application and relatively low manufacturing costs. Attenuated cold-adapted vaccine strains that have achieved a satisfactory balance between restricted replication and high immunogenicity are desirable. The immunogenicity of live attenuated vaccines may depend upon the interplay between its ability to induce pro-inflammatory cytokine responses and the relative sensitivity of the attenuated vaccine strain to an antiviral effect of these cytokines. To better understand the relationship between attenuation and induction of innate immunity as well as contribution of the early cytokine response to the relative immunogenicity of LAIVs, we have studied early protection induced by LAIV in vivo as well as early cytokine response in human cells macrophage origin in response to infection with vaccine strains or epidemic virus.
 The aim of this study was to investigate the early immune response and protective activity in female CBA mice intranasally immunized with cold-adapted influenza vaccine strains of different genome compositions of 5:3 or 6:2. For experimental infection pandemic influenza viruses A/South Africa/3626/13 (H1N1)pdm09 and A/New York/61/15 (H1N1)pdm09 were used to be administered to animals at a dose of 106 EID50 at day 3 after immunization (challenge infection). Although challenge viruses replicate at mice lungs at various, extend, on day 10 after immunization mice were protected from death from 60 up to 80%. Reassortants LAIV did not differ statistically on these levels.
 Study of the expression of IFN- and IFN- genes in human lung macrophage line cells THP-1 in vitro have shown that macrophages stimulated with vaccine strains with the genome formula 6:2 and 5:3, had a sufficient level of expression of these genes, comparable to that, as in infection with wild virus type A/South Africa/3626/13 (H1N1)pdm09. These data may indicate that surface proteins of influenza A virus are involved in the process of stimulation of the IFN- and IFN- genes.

Ідентифікація канцерогенності карбендазиму: експериментальне дослідження на мишах лінії СВА

ABSTRACT. Introduction. Carbendazim is a systemic benzimidazole fungicide rated as a possible human carcinogen. In Ukraine, over 20 carbendazim-based preparative forms of fungicides, predominantly generics, are registered, therefore, oncogenicity study of carbendazim from different manufacturers is of immediate interest. Objective of the paper is to identify carcinogenicity of 98 % technical carbendazim under conditions of chronic experiment in mice Methods. A total of 280 male and 280 female CBA mice were included in the study. Carbendazim was intragastrically administered in these animals for 18 months 5 times per week via a gastric tube at the doses of 0, 5, 25 and 75 mg/kg body weight as 0, 0.1, 0.5 and 1.5 % ex tempore prepared a suspension. Dead as well as sacrificed animals according to the experimental schedule were subjected to autopsy. Carcinogenicity was assessed using direct effect parameters — tumour ratio and their latent period. Results and Discussion. Clinical parameters of the condition of experimental animals, survival and incidence of premalignancy did not differ from those in the control animals. The main cause of death in animals throughout the study were non-specific intercurrent diseases developed with approximately the same rate in the experimental and control group. Tumour incidence (n = 37) in experimental and control groups did not statistically differ and complied with the spontaneous level in CBA mice. Conclusion. Incidence of tumours, their histological structure, location and latent period in experimental animals on carbendazim at the dose of 5, 25 and 75 mg/kg did not differ from those in the control group. Thus, the experimental study of carbendazim in CBA mice after intragastric administration for 78 weeks did not reveal the carcinogenic potential of the substance. Key Words: pesticides, carbendazim, carcinogenicity, mice.

Sexually dimorphic tibia shape is linked to natural osteoarthritis in STR/Ort mice

SummaryObjectivesHuman osteoarthritis (OA) is detected only at late stages. Male STR/Ort mice develop knee OA spontaneously with known longitudinal trajectory, offering scope to identify OA predisposing factors. We exploit the lack of overt OA in female STR/Ort and in both sexes of parental, control CBA mice to explore whether early divergence in tibial bone mass or shape are linked to emergent OA.MethodWe undertook detailed micro-CT comparisons of trabecular and cortical bone, multiple structural/architectural parameters and finite element modelling (FEM) of the tibia from male and female STR/Ort and CBA mice at 8–10 (pre-OA), 18–20 (OA onset) and 40 + weeks (advanced OA) of age.ResultsWe found higher trabecular bone mass in female STR/Ort than in either OA-prone male STR/Ort or non-prone CBA mice. Cortical bone, as expected, showed greater cross-sectional area in male than female CBA, which surprisingly was reversed in STR/Ort mice. STR/Ort also exhibited higher cortical bone mass than CBA mice. Our analyses revealed similar tibial ellipticity, yet greater predicted resistance to torsion in male than female CBA mice. In contrast, male STR/Ort exhibited greater ellipticity than both female STR/Ort and CBA mice at specific cortical sites. Longitudinal analysis revealed greater tibia curvature and shape deviations in male STR/Ort mice that coincided with onset and were more pronounced in late OA.ConclusionGeneralised higher bone mass in STR/Ort mice is more marked in non OA-prone females, but pre-OA divergence in bone shape is restricted to male STR/Ort mice in which OA develops spontaneously.

Investigation of cytotoxicity and skin-sensitizing potential of Asarum radix oil using LLNA:BrdU-ELISA

Asarum radix extract is commonly used in cosmetic products. Cytotoxicity testing and an ex vivo local lymph node 5-bromo-2-deoxyuridine (LLNA-BrdU) assays were performed to determine the dermal sensitization potential of A. radix extracts. The cytotoxicity assay indicated inhibitory effects on cell viability in a human forearm skin fibroblast cell line after 24-h incubation at concentrations of A. radix extract above 0.075 mg/mL. To assess skin sensitization, A. radix extracts (10%, 25%, and 50% v/v) were applied to the ears (dorsal surface) of female CBA mice. Changes in clinical signs, body weight, skin reactions, ear thickness, skin stimulation index (SI), and mortality were evaluated. After 6 days, no changes in treatment-related clinical signs, skin reactions, erythema, body weight, or mortality were observed in any treatment group. The results of the ex vivo LLNA-BrdU assays yielded a moderate SI of 3.09%. For the 10%, 25%, and 50% (v/v) treatment groups, SIs were calculated as 0.9, 1.2, and 2.1, respectively. Thus, at concentrations below 25% (v/v), A. radix oil was not skin sensitizing.

Cross-reactivity between methylisothiazolinone, octylisothiazolinone and benzisothiazolinone using a modified local lymph node assay.

In the light of the exceptionally high rates of contact allergy to the preservative methylisothiazolinone (MI), information about cross-reactivity between MI, octylisothiazolinone (OIT) and benzisothiazolinone (BIT) is needed. To study cross-reactivity between MI and OIT, and between MI and BIT. Immune responses to MI, OIT and BIT were studied in vehicle and MI-sensitized female CBA mice by a modified local lymph node assay. The inflammatory response was measured by ear thickness, cell proliferation of CD4+ and CD8+ T cells, and CD19+ B cells in the auricular draining lymph nodes. MI induced significant, strong, concentration-dependent immune responses in the draining lymph nodes following a sensitization phase of three consecutive days. Groups of MI-sensitized mice were challenged on day 23 with 0·4% MI, 0·7% OIT and 1·9% BIT - concentrations corresponding to their individual EC3 values. No statistically significant difference in proliferation of CD4+ and CD8+ T cells was observed between mice challenged with MI compared with mice challenged with BIT and OIT. The data indicate cross-reactivity between MI, OIT and BIT, when the potency of the chemical was taken into account in choice of challenge concentration. This means that MI-sensitized individuals may react to OIT and BIT if exposed to sufficient concentrations.

Erratum to: Oncolytic virus efficiency inhibited growth of tumour cells with multiple drug resistant phenotype in vivo and in vitro.

Tumour resistance to a wide range of drugs (multiple drug resistant, MDR) acquired after intensive chemotherapy is considered to be the main obstacle of the curative treatment of cancer patients. Recent work has shown that oncolytic viruses demonstrated prominent potential for effective treatment of diverse cancers. Here, we evaluated whether genetically modified vaccinia virus (LIVP-GFP) may be effective in treatment of cancers displaying MDR phenotype. LIVP-GFP replication, transgene expression and cytopathic effects were analysed in human cervical carcinomas KB-3-1 (MDR−), KB-8-5 (MDR+) and in murine melanoma B-16 (MDR−), murine lymphosarcomas RLS and RLS-40 (MDR+). To investigate the efficacy of this therapy in vivo, we treated immunocompetent mice bearing murine lymphosarcoma RLS-40 (MDR+) (6- to 8-week-old female CBA mice; n = 10/group) or melanoma B-16 (MDR−) (6- to 8-week-old female C57Bl mice; n = 6/group) with LIVP-GFP (5 × 107 PFU of virus in 0.1 mL of IMDM immediately and 4 days after tumour implantation). We demonstrated that LIVP-GFP replication was effective in human cervical carcinomas KB-3-1 (MDR−) and KB-8-5 (MDR+) and in murine melanoma B-16 (MDR−), whereas active viral production was not detected in murine lymphosarcomas RLS and RLS-40 (MDR+). Additionally, it was found that in tumour models in immunocompetent mice under the optimized regimen intratumoural injections of LIVP-GFP significantly inhibited melanoma B16 (33 % of mice were with complete response after 90 days) and RLS-40 tumour growth (fourfold increase in tumour doubling time) as well as metastasis. The anti-tumour activity of LIVP-GFP is a result of direct oncolysis of tumour cells in case of melanoma B-16 because the virus effectively replicates and destroys these cells, and virus-mediated activation of the host immune system followed by immunologically mediated destruction of of tumour cells in case of lymphosarcoma RLS-40. Thus, the recombinant vaccinia virus LIVP-GFP is able to inhibit the growth of malignant cells with the MDR phenotype and tumour metastasis when administered in the early stages of tumour development.

Oncolytic virus efficiency inhibited growth of tumour cells with multiple drug resistant phenotype in vivo and in vitro.

BackgroundTumour resistance to a wide range of drugs (multiple drug resistant, MDR) acquired after intensive chemotherapy is considered to be the main obstacle of the curative treatment of cancer patients. Recent work has shown that oncolytic viruses demonstrated prominent potential for effective treatment of diverse cancers. Here, we evaluated whether genetically modified vaccinia virus (LIVP-GFP) may be effective in treatment of cancers displaying MDR phenotype.MethodsLIVP-GFP replication, transgene expression and cytopathic effects were analysed in human cervical carcinomas KB-3-1 (MDR−), KB-8-5 (MDR+) and in murine melanoma B-16 (MDR−), murine lymphosarcomas RLS and RLS-40 (MDR+). To investigate the efficacy of this therapy in vivo, we treated immunocompetent mice bearing murine lymphosarcoma RLS-40 (MDR+) (6- to 8-week-old female CBA mice; n = 10/group) or melanoma B-16 (MDR−) (6- to 8-week-old female C57Bl mice; n = 6/group) with LIVP-GFP (5 × 107 PFU of virus in 0.1 mL of IMDM immediately and 4 days after tumour implantation).ResultsWe demonstrated that LIVP-GFP replication was effective in human cervical carcinomas KB-3-1 (MDR−) and KB-8-5 (MDR+) and in murine melanoma B-16 (MDR−), whereas active viral production was not detected in murine lymphosarcomas RLS and RLS-40 (MDR+). Additionally, it was found that in tumour models in immunocompetent mice under the optimized regimen intratumoural injections of LIVP-GFP significantly inhibited melanoma B16 (33 % of mice were with complete response after 90 days) and RLS-40 tumour growth (fourfold increase in tumour doubling time) as well as metastasis.ConclusionThe anti-tumour activity of LIVP-GFP is a result of direct oncolysis of tumour cells in case of melanoma B-16 because the virus effectively replicates and destroys these cells, and virus-mediated activation of the host immune system followed by immunologically mediated destruction of of tumour cells in case of lymphosarcoma RLS-40. Thus, the recombinant vaccinia virus LIVP-GFP is able to inhibit the growth of malignant cells with the MDR phenotype and tumour metastasis when administered in the early stages of tumour development.Electronic supplementary materialThe online version of this article (doi:10.1186/s12967-016-1002-x) contains supplementary material, which is available to authorized users.

Increased cystic fibrosis transmembrane conductance regulators expression and decreased epithelial sodium channel alpha subunits expression in early abortion: findings from a mouse model and clinical cases of abortion.

The status of the maternal endometrium is vital in regulating humoral homeostasis and for ensuring embryo implantation. Cystic fibrosis transmembrane conductance regulators (CFTR) and epithelial sodium channel alpha subunits (ENaC-α) play an important role in female reproduction by maintaining humoral and cell homeostasis. However, it is not clear whether the expression levels of CFTR and ENaC-α in the decidual component during early pregnancy are related with early miscarriage. CBA×DBA/2 mouse mating has been widely accepted as a classical model of early miscarriage. The abortion rate associated with this mating was 33.33% in our study. The decidua of abortion-prone CBA female mice (DBA/2 mated) had higher CFTR mRNA and protein expression and lower ENaC-α mRNA and protein expression, compared to normal pregnant CBA mice (BLAB/C mated). Furthermore, increased CFTR expression and decreased ENaC-α expression were observed in the uterine tissue from women with early miscarriage, as compared to those with successful pregnancy. In conclusion, increased CFTR expression and decreased ENaC-α expression in the decidua of early abortion may relate with failure of early pregnancy.

Evaluation of Sex Sensitivity in Local Lymph Node Assay Using Acephate and α- Hexylcinnamaldehyde

The current OECD Test Guideline for the conduct of the Local Lymph Node Assay (LLNA) recommends the use of only female mice for the assessment of skin sensitization potential for a given chemical. The NIH publication N° 99-4494 recommends that only female CBA mice be used, as they reportedly develop a stronger contact dermatitis response when compared to males however if male to be used, systematic studies evaluating potential sex differences should be conducted. Moreover, males were reported to display a larger variation in response due to a greater tendency to fight and to be involved in 'social ranking' behavior when group housed. However, there are several advantages to consider with the inclusion of male mice in LLNA testing including a more refined and responsible use of animals. Therefore, to begin to systematically assess the appropriateness of using male mice in the LLNA a comparative guideline study was conducted with individual housing of mice using a non-sensitizer and a sensitizer viz., Acephate 97 DF and α-hexylcinnamaldehyde (HCA) respectively. We have conducted an in-house study using a vehicle (dimethyl formamide) that is recommended by OECD 429 for the testing of mixtures in the LLNA for assessing skin sensitisation. We conducted the test according to the methods described by OECD 429 (Skin Sensitization: Local Lymph Node Assay). One common pesticide formulation, Acephate 97 DF and one known skin sensitizer - HCA, were each applied to the dorsum of both ears (25 µL per ear) of groups of 5 female CBA/J mice (male and female). Acephate 97 DF was applied at 3 separate concentrations and one concentration for HCA for 3 consecutive days (days 0, 1 and 2). A further group was given the vehicle (dimethyl formamide), alone. On day 5, all mice were injected intravenously (tail vein) with approximately 20 (±1) µCi of tritiated methyl thymidine. Five hours post-administration the uptake of 3H-thymidine into the auricular (local) lymph nodes draining the site of chemical application was measured in order to assess the proliferative response of the lymph node. The DPM values were measured individually for each mouse. Stimulation Index (SI Value) was calculated and are given below: - Acephate 97 DF (Male) (10%) 1.16 (25%) 1.58 (50%) 1.59 - Acephate 97 DF (Female (10%) 1.39 (25%) 1.55 (50%) 1.56 -

81st Annual Meeting of the American Thyroid Association SHORT CALL ABSTRACTS

81st Annual Meeting of the American Thyroid Association SHORT CALL ABSTRACTS

Abstract A4: Protection against radiation-induced carcinogenesis

Abstract The rationale of this study stems from the concern of radiation-induced second malignancies after a course of definitive radiation therapy or the possibility of a terrorist-mediated nuclear attack resulting in large populations of people exposed to non-lethal radiation doses, which would substantially increase the risk for cancer induction post-exposure. Currently, there are no safe and effective interventions to reduce this risk to humans. Previous studies have shown that chronic administration of Tempol (nitroxide antioxidant) in the diet of mice results in decreased weight and spontaneous tumorigenesis, and increased tumor latency (Mitchell JB, et al., Free Radic Biol Med 34:93-102, 2003). In the current study we tested the hypothesis that Tempol (TP) administered in the diet of mice would reduce radiation-induced cancer when given after the radiation exposure. Total body radiation (3 Gy) was administered to female C3H and CBA mice. Along with various control groups, immediately after radiation one group of animals from each strain was placed on a TP diet. Food consumption and animal weights were monitored throughout the study. Animals were followed for their entire lifespan (>1300 mice). The endpoint for the study was tumor formation or until the animal reached a humane endpoint at which time the animal was euthanized and evaluated for the presence of tumor (pathology evaluated on all animals). TP food supplementation after radiation: a) did not alter food consumption compared to animals on a control food diet, b) compared to animals on control food diet, the TP diet resulted in decreased weights in both mouse strains (40% for C3H and 20% for CBA), and c) TP food supplementation post-radiation significantly enhanced the survival of both mouse stains. Median survival values for 0 Gy, 3 Gy, 0 Gy TP, and 3 Gy TP for C3H mice was 706, 434, 764, and 670 days, respectively. For CBA mice median survival values for 0 Gy, 3 Gy, 0 Gy TP, and 3 Gy TP for C3H mice was 901, 660, 939, and 782 days, respectively. The incidence of hematopoietic neoplasms (predominantly lymphomas) was significantly reduced in both mouse strains by TP treatment and both the onset and incidence of solid neoplasms was significantly reduced in CBA mice treated with TP. These results encourage more research on nitroxide-based antioxidants in the chemoprevention of cancer to elucidate the mechanism(s) involved. Citation Information: Cancer Prev Res 2010;3(12 Suppl):A4.

Post-Stress Changes in the Attractiveness of Female Mouse Chemosignals to Intact Males

During the early period (1-4 days) after stress, female CBA and C57BL6 (B6) mice were found to excrete volatile components (chemosignals) in the urine, which are more attractive to intact males of these same strains, regardless of genotype, than the secretions of intact females. At later time point; there were wavelake changes in the attractiveness of the secretions of stressed females, though the difference between the intact and stressed groups of females disappeared by one month. Comparison of the secretions of stressed CBA and B6 females showed that intact males preferred the post-stress chemosignals of syngeneic (genetically identical) individuals during the period 1-14 days. This phenomenon - post-stress reversion of the female genotype-dependent olfactory attractiveness to males - was significantly different from normal, where males show a consistent preference for the chemosignals of allogeneic (with different genotypes) females. The pattern of male preference for the chemosignals of stressed syngeneic females was also seen on direct comparison with the chemosignals of intact allogeneic females. Normal female chemosignaling recovered during the 2-3 weeks after stress. The biological significance of these phenomena is discussed.

Cyp4a14 overexpression induced by hyperoxia in female CBA mice as a possible contributor of increased resistance to oxidative stress

The beneficial effects of hyperoxia have been noted in treatment of several diseases and pathological states. However, the excessive production of ROS under hyperoxic conditions can directly damage cellular macromolecules if the imbalance in antioxidant status exists. Cytochrome P450 (Cyp) 4a14 has an important role in the metabolism of lipids and as a source of ROS in oxidative stress. This study investigated the oxidant/antioxidant status as a response to hyperoxia treatment in liver of young CBA/Hr mice of both sexes and whether the observed response is mediated by Cyp4a14 via PPAR isoforms in a sex-dependent manner. The overexpression of Cyp4a14, lack of both LPO and of 4-hydroxynonenal(HNE)-protein adducts revealed by immunohistochemical analysis in hyperoxia-treated females indicates their greater resistance to hyperoxia compared to males, which is parallelled to changes in PPARβ/δ and PPARγ expression. These results suggest the presence of sex-dependent changes in all investigated parameters, which points out sex-related susceptibility towards oxidative stress and hyperoxia treatment of various pathological conditions and diseases.

Hormone replacement therapy diminishes hearing in peri-menopausal mice

We recently discovered that progestin in hormone replacement therapy (HRT) for post-menopausal women has detrimental effects on the ear and central auditory system [Guimaraes, P., Frisina, S.T., Mapes, F., Tadros, S.F., Frisina, D.R., Frisina, R.D., 2006. Progestin negatively affects hearing in aged women. Proc. Natl. Acad. Sci. – PNAS 103, 14246–14249]. To start determining the generality and neural bases of these human findings, the present study examined the effects of combination HRT (estrogen + progestin) and estrogen alone on hearing in peri-menopausal mice. Specifically, auditory brainstem responses (ABRs-sensitivity of the auditory system) and distortion-product otoacoustic emissions (DPOAEs-cochlear outer hair cell system) were employed. Middle age female CBA mice received either a time-release, subcutaneous implanted pellet of estrogen + progestin, estrogen alone, or placebo. Longitudinal comparisons of ABR threshold data obtained at 4 months of treatment revealed statistically significant declines in auditory sensitivity over time for the combined estrogen + progestin treatment group, with the estrogen only group revealing milder changes at 3, 6 and 32 kHz. DPOAE testing revealed statistically significant differences for the estrogen + progestin treatment group in the high and middle frequency ranges (15–29 and 30–45 kHz) after as early as 2 months of treatment ( p < 0.01 and p < 0.001, respectively). Statistically significant changes were also seen at 4 months of treatment across all frequencies for the combined HRT group. These data suggest that estrogen + progestin HRT therapy of 4 months duration impairs outer hair cell functioning and overall auditory sensitivity. These findings indicate that estrogen + progestin HRT may actually accelerate age-related hearing loss, relative to estrogen monotherapy; findings that are consistent with the clinical hearing loss observed in aging women that have taken combination HRT.

Evaluation of Immunotherapy Efficiency in Mouse CaO-1 Ovarian Carcinoma Treated by Vaccines Based on Dendritic Cells

Injection of dendritic cells, pulsated by tumor lysate or mucin, containing CA 125 antigen, led to a more than 50% inhibition of tumor growth in female CBA mice with transplanted mouse pseudomucinous CaO-1 ovarian carcinoma in comparison with the control. Tumor-associated CA 125 antigen can be used for obtaining dendritic cell vaccines against ovarian malignant tumors. This trend will extend the potentialities of application of antitumor vaccines based on dendritic cells, as clinical use of this technology is limited by the need in patient's tumor material. Mucin, containing Ca 125 antigen, can be isolated from patient's serum or obtained by gene engineering technologies as a recombinant peptide.

Artemether Treatment of Prepatent Schistosoma japonicum Induces Resistance to Reinfection in Association with Reduced Pathology

Artemether (ART) is a well-described antimalarial with efficacy against juvenile schistosomes, with 7-day-old schistosomula being particularly susceptible. Both ART-affected worms and parasites developing from irradiated cercariae die at similar times after infection. Our aim was to determine if ART treatment of prepatent schistosomiasis japonica may result in the generation of a protective immune response. Female CBA mice were treated with a single dose of ART at defined time points after percutaneous infection with a virulent Chinese mainland strain of Schistosoma japonicum. Half of the mouse cohorts were subjected to homologous parasite strain reinfection after drug treatment to assess protective effects of ART therapy. Two independent trials demonstrated that a statistically significant (58% and 50%) reduction in challenge worm burden occurred after reinfection of those mice treated with ART at two weeks p.i. A reduction in the IL-4 response to soluble worm antigen preparation (SWAP) was also seen in ART-treated mice but with no correlation to reinfection resistance. In the Chinese mainland strain used, ART treatment of prepatent infection at the appropriate time point induced resistance to reinfection. There was also an anti-pathology effect observed in ART-treated mice that remained significant after reinfection.

Oral poly(ethylene glycol)-conjugated human recombinant lysozyme control of lung metastases in mice

Human recombinant lysozymes (rHLZs), particularly hen egg-white lysozyme (HEL), are promising agents for the treatment of diseases such as cancer. However, in a similar but improved fashion to what has already been demonstrated using HEL, the PEGylation of an rHLZ leads to a new drug that appears to protect against spontaneous lung metastasis development in mice bearing mammary carcinoma (MCa). The oral administration of 25-100 mg/kg/day of rHLZ-PEG (HEL-equivalent dose) to CBA female mice, admixed with daily food for 14 consecutive days, significantly reduced the growth of the primary tumour by up to 30% and of lung metastasis weight by up to 95%, as compared to the untreated controls. An anti-metastatic effect significantly higher than that of uncoupled rHLZ was also confirmed in MCa-carrying animals immunosuppressed by cyclophosphamide or cyclosporine. This is of note if one takes into consideration the fact that virtually all chemotherapeutic regimens can cause immune system depression, with a consequent limitation of the dosage and effectiveness of anti-tumour treatments.