Osteosarcomas in BALB/c female mice

Osteosarcomas were found in 16 of 24,192 (0.066%) BALB/c female mice, 14 were in 21,816 (0.064%) 2-acetylaminofluorene-treated mice, and two were in 2,376 (0.084%) untreated controls. The osteosarcomas were classified into osteoblastic, fibroblastic, and mixed types. Seven of the osteosarcomas metastasized to the lungs. The osteosarcomas in control and 2-acetylaminofluorene-treated mice showed little or no difference in the incidence, type, size, or site of origin, indicating that 2-acetylaminofluorene did not affect the development of osteosarcomas in BALB/c female mice.U     

Spontaneous heart failure in BALB/c mice

The hearts of BALB/c mice are known to acquire pronounced greyish white spots (cardiac white spots). BALB/c male mice were examined for the relationship between the incidence of cardiac white spots and weekly age, and compared with DDY male mice. During the observation period of 0.4-30 weeks, cardiac white spots on the right ventricle of BALB/c mice were first detected at three weeks (6 of 20 mice; 30%), and the maximal incidence of cardiac white spots was obtained at nine weeks (39 of 44 mice; 88%). In contrast, DDY mice were completely devoid of cardiac spots. Histopathologically, the cardiac spots were dystrophic calcinosis. There were significant increases in the relative organ weights of the heart and kidney of BALB/c mice compared with those of DDY mice. However, there was no significant difference between BALB/c and DDY mice in serum calcium concentration or histological characteristics of the parathyroid gland or bone marrow. The cardiac white spots of BALB/c mice were considered to be controlled by genetic susceptibility that occurred spontaneously with aging. The results described here suggest that BALB/c mice are adequate experimental animals for the study of myocardial disease that occurs spontaneously.     

Passage of hybridomas in male BALB/c mice

For cultivating hybridomas in the ascitic form there are usually used female mice BALB/c and not male ones. Efficiency of production of monoclonal antibodies with cultivation of the hybridomas in male and female mice BALB/c was studied comparatively. The animals were stimulated to form ascite by administration of the incomplete Freund's adjuvant or 3 per cent peptone with petrolatum oil. Some parameters of the ascite formation were studied: viability of the hybridoma cells, ascitic fluid formation period and volume, hybridoma cell concentration and titers of monoclonal antibodies in the ascitic fluid. In regard to all the parameters studied the male animals were not inferior to the female ones and in case of one of the hybridomas even surpassed them twofold by the volume of the ascitic fluid formed. This is evident of possible using male mice for mass cultivation of hybridoma cells with a purpose of obtaining preparative amounts of monoclonal antibodies in production of immunodiagnostic agents on their basis.     

Study on the ophthalmic diseases in ICR mice and BALB/c mice.

In pharmaceutical companies and research institutes, many toxicity tests are performed with laboratory animals. This study was performed to produce reference data for eye toxicity tests and to investigate the ophthalmic diseases of 408 ICR mice and 119 BALB/c mice, which are commonly used as subjects in toxicity tests. The experimental animals without clinical disorders were selected regardless of sex. The ophthalmic diseases were examined by using special ophthalmic instruments: direct ophthalmoscope, indirect ophthalmoscope, slit-lamp biomicroscope and focal illuminator. The most prevalent ocular variation within normal limits was hyaloid vessel remnant (ICR mice, 28.2%; BALB/c mice, 31.9%) and the incidence gradually decreased with age. The ocular diseases found in ICR mice were retinal degeneration (9.8%), corneal scar (4.2%), focal cataract (2.2%), anisocoria (1.2%), corneal ulcer (0.2%) and uveitis (0.2%). In BALB/c mice, corneal scar (9.2%), focal cataract (1.7%) and corneal ulcer (0.8%) were the ocular diseases found.     

Comparison of the homogeneous, primary anti-dextran B1355 antibody raised in BALB/c mice with protein 104E

The primary antibody response to dextran B1355 in BALB/c mice is largely a homogenous IgM antibody. This antibody appears to be similar if not identical to the myeloma protein, protein 104E, for the following reasons: a) isoelectric focusing of the 7S monomers, separately and together in co-isoelectric focusing, give the same pattern, both in the presence and absence of 4M urea; b) the inhibition of lysis of the dextran-coated SRBC by specifically purified anti-dextran antibody and by protein 104E required essentially the same concentration of dextran B1355. This similarity was further demonstrated by plaque assays with dextran-coated SRBC, in which the formation of plaques was inhibited by free dextran. Inhibition of plaques produced by both types of cells required essentially the same concentration of dextran B1355. On these bases, there appears to be no difference in properties (or in structure) between the myeloma protein and the induced antibody.     

Bacteriology of the oral cavity of BALB/c mice

To be used as a model in dental research, an animal must fulfil experimental needs and information on the composition and variation of its oral flora must be available. Only limited data are available on the indigenous oral bacterial flora of BALB/c mice. In this work, a total of 671 isolates from different sites (saliva, tongue, teeth, and mucosa) of the oral cavity of BALB/c mice were identified. Only 18 different species were isolated, which indicates the relative simplicity of the flora. The predominant species of the total cultivable flora were "Lactobacillus murinus" (38%), Staphylococcus aureus (37%), Streptococcus faecalis (8%), Staphylococcus sciuri (4%), and Escherichia coli (3%). The other species each represent less than 2% of the flora. "Lactobacillus murinus" is found in greater proportion on mucosa than in the other sites, Staph. aureus predominates in saliva, and Strep. faecalis was found in greater proportion in tooth samples. Statistical analyses, using the minimum percentage of similarity, indicate that there is some variation among the microflora of different mice but that this difference is smaller for mice from the same lot. These results set the basis for the study of the variations of the indigenous oral microflora of BALB/c mice under different conditions.     

双歧杆菌增强小鼠机体的免疫功能

【目的】本研究针对实验室自行从内蒙传统发酵乳制品中分离得到的两株双歧杆菌Bifidobacterium adolescentis BB-2和B.longum BB-3,对其调节机体免疫的功能进行了评价。【方法】采用健康SPF级BALB/c小鼠,每组10只,空白组灌胃无菌脱脂乳,阳性对照组灌胃含有商业菌株BB-12的无菌脱脂乳,处理组同样以无菌脱脂乳为溶液,灌胃含有不同剂量的Bifidobacterium adolescenti BB-2或B.longum BB-3,测定细胞免疫(迟发型变态反应DTH、脾淋巴细胞增殖MTT显色反应、自然杀伤细胞活性),体液免疫(绵羊红细胞免疫后的血清溶血素活性),以及非特异性免疫(巨噬细胞吞噬活性)指标。【结果】表明BB-2和BB-3两株双歧杆菌均能够增强DTH反应。双歧杆菌组小鼠的巨噬细胞的吞噬活性也有提高,同时自然杀伤细胞活性及血清溶血素水平也高于对照组,菌株处理组的脾淋巴细胞增殖率也有提高。剂量效应不显著,其中低剂量浓度(102-6cfu/m L)即可发挥作用。【结论】证明双歧杆菌BB-2和BB-3能够促进小鼠先天性免疫力和获得性免疫力的提高。本研究的开展对开发我国具有自主产权的功能菌株具有重要意义。     

Attenuation of mammary duct development by menhaden oil in BALB/c mice

The predominant polyunsaturated fatty acids of the n-6 family found in corn oil (CO) are crucial for normal mammary duct formation when fed to animals. However, as shown here, not all polyunsaturated fatty acids are equally effective in stimulating mammary gland development. The n-3 fatty acids in a 10% menhaden oil (MO) diet fed to mice effectively reduced both the diameter and the length of the growing mammary ducts. Previously, we demonstrated a similar reduction in duct growth by feeding a 10% fat diet high in those saturated fats found in hydrogenated cotton seed oil. The inhibited rate of duct maturation caused by hydrogenated cotton seed oil was reversed when the mice were allowed to mature on a diet containing n-6 fatty acids prior to feeding the saturated fat diet. The addition of 1% CO to a 9% hydrogenated cotton seed oil diet fed to immature mice was also sufficient to restore duct growth. Mice fed menhaden oil diets, on the other hand, continued to show impaired ductal growth well into adulthood. Examination of the ovaries from MO-fed mice as compared with CO-fed mice revealed significantly fewer corpora lutea. When exogenous progesterone was given to MO-fed mice, ductal growth was partially restored, but not to the extent seen in mice fed corn oil diets. Investigation of the fatty acid contents of livers of these mice revealed reduced amounts of arachidonate (20:4) in MO-fed mice when compared with CO-fed animals. The addition of 1% CO to the 9% MO diets did not alter the arachidonate content, indicating a block in the conversion of linoleate (18:2) to 20:4 by the n-3 fatty acids. Hence, dietary n-6 fatty acids are essential for normal mammary ductal development when fed prior to maturation. Although saturated rats are ineffective, n-3 fatty acids can partially substitute for the required n-6 fatty acids in both ductal and ovarian development.     

猪圆环病毒3型感染BALB/c小鼠的实验观察

目的研究猪圆环病毒3型(porcine circovirus3,PCV3)对BALB/c小鼠的感染情况。方法将雌性BALB/c小鼠分为两组,实验组感染PCV3组织毒,对照组接种同样剂量的PBS。感染后每天观察小鼠状态,并在第0,3,7,11和14天采血进行荧光定量PCR检测和ELISA检测。实验结束后,对所有动物进行安乐死和剖检,对心脏、肝、脾、肺、肾、脑和淋巴结取样进行荧光定量PCR检测,并制片进行组织病理学检查。选择PCR检测阳性组织进行PCV3CAP基因测序分析。结果PCV3组织毒感染小鼠不引起明显的临床症状和病理变化。病毒可在感染早期的血清中检测到,病毒含量最高的器官是肝脏和脾脏,PCV3感染小鼠后核酸序列未发生变化。随着感染时间的增加血清中抗体水平逐渐升高。结论PCV3可以感染BALB/c小鼠,并在小鼠体内增殖。本研究结果为猪圆环病毒3型致病性的研究以及防控提供了参考。     

Comparison of the distribution kinetics and metabolism to acid end-products of corticosterone and 11-deoxycorticosterone in BALB/c mice

The conversion of [4 14C]corticosterone[( 14C]B) and 11-deoxy-[1,2-3H]corticosterone [( 3H]DOC) to steroidal carboxylic acids was studied in the BALB/c mouse. There was rapid and preferential excretion of [3H]DOC metabolites into the gastrointestinal tract. Excretion of 14C through the kidney was higher than 3H excretion. Within minutes of intraperitoneal injection, levels of 3H and 14C in most organs reached their maximal levels and subsequently decreased in an exponential pattern. The majority of the organs took up 14C to a greater extent than 3H. Using tissue blood ratio of tracer (T/B) as criterion, it was found that liver, gall bladder, intestine, and kidney concentrated 3H and 14C-labeled steroid from blood. T/B for 3H exceeded that for 14C in the gastrointestinal tract. Abdominal fat preferentially took up [3H]DOC tracer, whereas [14C]B tracer was not taken up by this tissue. T/B was less than 1 for 3H and 14C in heart, thymus, spleen, brain, skeletal muscle and skin. In these organs uptake of B and its metabolites was greater than that of DOC and its metabolites. In liver, [14C]B and [3H]DOC were converted to carboxylic acid metabolites which accumulated in the intestine. The most abundant acid was 11 beta,20 alpha-dihydroxy-3-oxo-pregn-4-en-21-oic acid from B. The acid metabolites of DOC were not identified. For both steroids, acids were major metabolic end-products.     

Trypanosoma cruzi: Impact of dual-clone infections on parasite biological properties in BALB/c mice

Herein, we have analyzed major biological properties following dual-clone Trypanosoma cruzi infections in BALB/c mice. Eight T. cruzi clonal stocks, two of each principal genotype, including genotype 19 and 20 (T. cruzi I), hybrid genotype 39 (T. cruzi) and 32 (T. cruzi II) were combined into 24 different dual-clone infections. Special attention was given to characterize biological parameters assayed including: prepatent period, patent period, maximum of parasitemia, day of maximum parasitemia, area under the parasitemia curve, infectivity, mortality, and hemoculture positivity. Our findings clearly demonstrated that features resultant of dual-clone infections of T. cruzi clonal stocks did not display either the characteristics of the corresponding monoclonal infections or the theoretical mixture based on the respective monoclonal infections. Significant changes in the expected values were observed in 4.2-79.2% of the mixtures considering the eight biological parameters studied. A lower frequency of significant differences was found for mixtures composed by phylogenetically distant clonal stocks. Altogether, our data support our hypothesis that mixed T. cruzi infections have a great impact on the biological properties of the parasite in the host and re-emphasizes the importance of considering the possible occurrence of natural mixed infections in humans and their consequences on the biological aspects of ongoing Chagas' disease.     

Cytokine production induced by marine algae lectins in BALB/c mice splenocytes

Marine algae can serve as sources of bioactive compounds and currently have been shown their potential biological and pharmaceutical applications. Marine algae lectins have been shown to be effective at controlling inflammatory processes. This work aimed to analyze the immunostimulatory properties of lectins from the marine algae Solieria filiformis (SfL), Pterocladiella capillacea (PcL) and Caulerpa cupressoides (CcL). This analysis was performed on BALB/c mouse splenocytes by measuring cytokine and nitric oxide production and cellular damage using tests of cytotoxicity and cell viability. These lectins were not cytotoxic (1-100 μg/mL), and were not able to induce IFN-γ and IL-2 production. IL- 10 production was induced at high levels by all lectins tested. Treatment with SfL induced IL-6 production at higher levels at all experimental times, whereas treatment with PcL and CcL induced higher levels only in 24 and 72 h. Treatment with SfL did not result in nitrite oxide production, whereas treatment with PcL or CcL was able to induce nitrite release at high levels (after 24, 48 and 72 h). Lesser cellular damage (5%) was observed in splenocytes treated with these lectins (10 μg/mL). Thus, the lectins from these algae were not cytotoxic, promoted increased in cell viability and induced Th2 immune responses in mouse splenocytes, indicating that they have anti-inflammatory effects.     

Pulmonary immune responses induced in BALB/c mice by Paracoccidioides brasiliensis conidia

Knowledge concerning the host–Paracoccidioides brasiliensis interactions is abundant. Yet, most of the experimental studies have used yeast cells to prepare the corresponding inoculum. As these cells do not represent the naturally infecting propagules, the corresponding experiments by-pass the earlier stages of such interactions. Studies done in patients, who also harbour yeast cells, suffer from the same bias. The review presented below focuses on the immune responses of BALB/c mice infected with conidia obtained from P. brasiliensis mycelial form cultures, the fungal stage most probably existing in nature. As such, the corresponding experiments would copy the onset and course of the human infection. A large number of experimental studies done by the CIB Medical and Experimental Mycology Unit in a period of almost 25 years have been revised and extracted so as to present a comprehensive record on the immune responses induced when mice are infected intranasally with the conidia. The establishment of this mouse model has permitted the analysis of the immune responses taking place during the early and late stages post-challenge. This unique model has made possible to characterize the course of the experimental disease including the inflammatory reaction, the expression of cytokines and of the various molecules associated to these responses, all of which lead to granuloma formation. The latter structure serves as a nest for the development of fibrosis. Thus, we have also obtained a glimpse on the complexity that accompanies the fibrosis, the most common sequelae of paracoccidioidomycosis. Additionally, a concerted effort has been made to appraise the whole gamut of immune factors and related molecules that directly or indirectly, contribute to shape the pathogenesis of this Latin American mycosis.     

Prevention of vertical transfer of Neospora caninum in BALB/c mice by vaccination

Neosporosis is an important cause of abortion and neonatal morbidity in dairy cattle. The disease is caused by Neospora caninum, an intracellular protozoan parasite. In this report, we describe the use of a mouse model in the preliminary evaluation of vaccination as a means to prevent vertical transfer of N. caninum. Parasites present in the tissues of the offspring were detected using an N. caninum-specific polymerase chain reaction assay. Immunization of dams with a single inoculation of a crude lysate of N. caninum tachyzoites appeared to induce complete protection against infection of the offspring.     

Gastrointestinal microecology of BALB/c nude mice.

The aerobic, facultative, and anaerobic microorganisms cultivable from the stomachs, ilea, ceca, and colons of BALB/c athymic (nu/nu) mice (normal and wasting), thymus-implanted normal nude mice, and their heterozygous (nu/+) littermates were investigated. Ninety-one species representing 23 genera of bacteria and yeasts were isolated from the 27 mice. The wasting nude mice showed significantly lower numbers of lactobacilli in their stomach microbiota than did mice from the other three groups. The littermate animals appeared unique among the four groups in having corynebacteria as a major constituent of their stomach and ileal flora. The normal nude mice appeared to have a more diverse anaerobic stomach flora than their heterozygous littermates. These minor differences are discussed with respect to possible immunological, physiological, and environmental factors as their cause. Because the gastrointestinal microfloras of the mice from the four groups were not radically divergent from each other, it was concluded that loss of T-cell function does not dramatically alter the makeup of the cultivable gastrointestinal microflora in these mice.     

Diversity of the Tcra-V3 gene family in BALB/c mice

 Southern analysis of Eco RI-digested BALB/c liver DNA reveals four T-cell receptor Tcra-V3-hybridizing DNA fragments, which are of sizes 18.0, 12.0, 8.0, and 2.1 kilobases, respectively. These four Tcra-V3-hybridizing genomic DNA were isolated from a BALB/c genomic library. Restriction and Southern analysis of the genomic DNA clones showed that each of the Tcra-V3-hybridizing Eco RI DNA fragments harbors only a single Tcra-V3 gene. The DNA sequences of coding regions of the four Tcra-V3 family members were determined. These sequences show very limited divergence from one another. Comparisons of BALB/c Tcra-V3 sequences with published Tcra-V3 sequences expressed in different strains of mice reveal substantial allelic polymorphism. Sequence similarity searches retrieved homologous rat, cattle, and human genes. The scarcity of coding sequence divergence among members of the Tcra-V3 family and the more substantial allelic polymorphism may be general features of the T-cell receptor V-alpha chain-encoding gene families. Received: 11 April 1996 / Revised: 26 May 1996     

Dense cataract and microphthalmia--new spontaneous mutation in BALB/c mice

We describe a new spontaneous mutation in BALB/c mice that causes abnormal phenotype, such as congenital cataract and microphthalmia. This abnormality was found to be inheritable because offspring with the same abnormality were produced by backcrossing the abnormal male to its normal female parent. Results of various crosses made to determine the mode of inheritance indicated that this abnormality is attributable to mutation of an autosomal recessive gene. Slit lamp examination of the mutant eyes revealed total lenticular opacity, disturbed typical iris pattern, and abnormal pupillary muscle development. Histologic changes in mutant eyes between gestation day 13 and postnatal day 1 indicated various eye and lens abnormalities, including microphthalmia; underdeveloped iris, optic stalk, cornea, and retina; degenerated lens fibers with lost fibrillar structure; and vacuoles of various sizes at the posterior border of the lens. Mild opacity of the lens was found to progress with age and became denser, resembling mature cataract, and occupying the lens completely at the age of six to eight weeks. We, therefore, temporarily designated this abnormality as dense cataract and microphthalmia, with the gene symbol dcm.     

Enhancement of exercise endurance capacity by fermented deer antler in BALB/c mice

To investigate the activity of fermented deer antler on exercise endurance capacity, we evaluated endurance capacity in five-week-old male BALB/c mice by administering the fermented deer antler extract (FA) or the non-fermented deer antler extract (NFA) and then subjected the mice to exercise in the form of swimming. The mice administered 500?mg/kg/day of FA showed a significant increase in swimming time compared with mice administered placebo (16.55?min vs. 21.64?min, P?<?0.05). Serum lactate dehydrogenase (LDH), the marker of the liver and muscle damage, was significantly lower in FA groups. However, NFA groups did not show significantly different swimming time or serum LDH from that of the control group. Moreover, the FA-500 group had significantly higher hepatic superoxide dismutase (SOD) activity after forced swimming than the control and NFA groups (P?<?0.05). These findings suggest that fermentation may increase the exercise endurance capacity of the deer antler.     

Lack of micronuclei induction by fumonisin B1 mycotoxin in BALB/c mice

The genotoxic potential of fumonisin B₁ (FB₁) in vivo in BALB/c mice (male and female) was assessed by induction of micronuclei (MN) formation in bone marrow polychromatic erythrocytes. The ratio of polychromatic erythrocytes to normochromatic erythrocytes (PCE/NCE) was also determined. Mice were injected intraperitoneally (i.p.) with FB₁ at a low dose (0.1 mg?kg^?1 body mass), middle dose (1.0 mg?kg^?1 body mass) and high dose (10 mg?kg^?1 body mass) as single and multiple doses in normal saline to test the genotoxicity. Mitomycin C, a known clastogen, was used as positive control. The frequency of MN and the PCE/NCE value in animals treated with FB₁ at low, middle, and high doses in single dose studies, and the frequency of MN in multiple dose studies, were statistically non-significant from that of the controls injected with saline only. The multiple dose studies at all doses revealed that the PCE/NCE value was found to be reduced upon exposure to FB₁ as compared to the controls. In animals injected with multiple low doses of FB₁, the PCE/NCE value was found to be 0.66 in males and 0.82 in the females; at multiple middle doses the value was 0.30 in males and 0.41 in the females and was statistically significant (p?<?0.001); however, at multiple high doses, the ratio was found to be 0.36 in both males and females. The present study confirms that FB₁ is non-genotoxic in nature while the reduced ratio of PCE/NCE suggests the cytotoxic nature of FB₁.