Association between Helicobacter pylori infection and platelet count in mice.

Strong evidence for an association between idiopathic thrombocytopenic purpura (ITP) and Helicobacter pylori (HP) infection has been reported in humans. Chronic ITP is known to be improved by the eradication of HP. The purpose of this study was to reproduce these events by the experimental infection of several strains of mice with HP. BALB/c, C57BL/6, and DBA/2 mice were untreated or orally inoculated with HP. Two months later, platelet counts were compared in samples from HP-infected and noninfected mice. Platelet counts (mean ± SD, × 104 cells/µl) in blood samples from HP-infected BALB/c, C57BL/6, and DBA/2 mice were 102.28 ± 14.71, 99.65 ± 17.00, and 111.57 ± 16.20, respectively; the respective counts from noninfected mice were 121.80 ± 13.30, 104.35 ± 18.20, and 107.84 ± 14.33. A significant difference in platelet counts between HP-infected and noninfected mice was observed in BALB/c mice (P≤0.01) but was not observed in DBA/2 mice, even though the histocompatibility (H)-2 type of the DBA/2 was the same as that of BALB/c mice. According to ELISA results, the optical density value for the anti-HP antibody in HP-infected BALB/c mice was not correlated with the number of platelets (P>0.50). These results suggest that the decrease in platelet count caused by HP infection is not related to antibody titer and histocompatibility-2 type. Experimental infection of BALB/c mice with HP can reproduce the relationship between HP and ITP and serves as a good model to investigate the mechanistic basis for the effectiveness of HP eradication therapy for ITP treatment.

Evaluation of mouse red blood cell and platelet counting with an automated hematology analyzer.

An evaluation of mouse red blood cell (RBC) and platelet (PLT) counting with an automated hematology analyzer was performed with three strains of mice, C57BL/6 (B6), BALB/c (BALB) and DBA/2 (D2). There were no significant differences in RBC and PLT counts between manual and automated optical methods in any of the samples, except for D2 mice. For D2, RBC counts obtained using the manual method were significantly lower than those obtained using the automated optical method (P<0.05), and PLT counts obtained using the manual method were higher than those obtained using the automated optical method (P<0.05). An automated hematology analyzer can be used for RBC and PLT counting; however, an appropriate method should be selected when D2 mice samples are used.

The activity of alkaline phosphatase in the sera of DBA/2NCrj and CBA/BrA mice with calcified tongue lesions.

Spontaneously occurring calcified lesions were found in the tongues of DBA/2NCrj and CBA/BrA mice. In the DBA/2NCrj strain, the frequency of the lesion was 80% (males) and 88% (females). The youngest age of a mouse with this lesion was 18 days after birth, and 3-4 lesions were found in the tongue of 6- to 8-week-old mice. In CBA/BrA mice, 20% of females and 48% of males had the lesions. No significant differences were found in the serum calcium concentrations in high and low lesion-developing strains, but the alkaline phosphatase activities in the high-developing DBA/2NCrj, DBA/LiA, and CBA/BrA strains were higher than in strains with no calcified lesions.

Membrane surface properties of lymphocytes of normal (DBA/2) and autoimmune (NZB/NZW)F1 mice: effects of L-canavanine and a proposed mechanism for diet-induced autoimmune disease.

Partitioning cells in a dextran polyethylene glycol aqueous two-phase system (countercurrent distribution, CCD) is a sensitive method for learning about cell surface membrane properties and for subfractionating cell populations. In this study, we subjected lymphocytes from normal DBA/2 mice and autoimmune F1 New Zealand black/New Zealand white [NZB/NZW)F1) mice to countercurrent distribution and found that T cells partition to the right and B cells partition to the left of the CCD curve. We found no difference between the CCD patterns of normal and autoimmune mice. When the murine lymphocytes were exposed to a cationic dietary amino acid (L-canavanine) in vitro, L-canavanine selectively affected the CCD pattern of autoimmune B cells, reflecting an alteration in surface membrane properties. We separated these lymphocytes with altered surface membrane properties by CCD. Impaired B-cell immune responses associated with L-canavanine were isolated to this lymphocyte fraction. This study provides the first evidence that alterations in the charged surface membrane properties are associated with abnormal (auto) immune response.

Atropine esterase status of laboratory mice.

Fifty eight inbred strains of laboratory mice and two species of wild mice [Mus castaneus (inbred) and Peromyscus maniculatus bairdii (closed colony)] were tested for the presence of atropine esterase by the microhematocrit tube test of Tucker and Beattie. The results show clearly that laboratory mice do not have significant levels of atropine esterase as determined either by the microhematocrit tube test or by the agar plate test, and therefore that under these conditions atropine esterase is not a polymorphic variant as has been demonstrated clearly in the rabbit.

Analysis of a mouse alpha-globin gene mutation induced by ethylnitrosourea.

A DBA/2 mouse treated with ethylnitrosourea sired an offspring whose hemoglobin showed an extra band following starch gel electrophoresis. The variant hemoglobin migrated to a more cathodal position in starch gel. Isoelectric focusing indicated that chain 5 of the mutant hemoglobin migrated to a more cathodal position than the normal chain 5 from DBA/2 mice and that the other alpha-globin, chain 1, was not affected. On focusing gels the phenotype of the mutant allele, Hbay9, was expressed without dominance to normal chain 5, and Hbay9/Hbay9 homozygotes were fully viable in the laboratory. The molecular basis for the germinal mutation was investigated by analyzing the amino acid sequence of chain 5y9, the mutant form of alpha-chain 5. A single amino acid substitution (His leads to Leu) at position 89 was found in chain 5y9. We propose that ethylnitrosourea induced an A leads to T transversion in the histidine codon at position 89 (CAC leads to CTC). This mutation has apparently not been observed previously in humans, mice or other mammals, and its novel occurrence may be indicative of other unusual mutational events that do not ordinarily occur in the absence of specific mutagen exposure.

Hemagglutination test for adenoviruses using mouse erythrocytes.

Mouse erythrocytes were used, instead of rat erythrocytes, for typing adenoviruses by hemagglutination. Mouse erythrocytes were agglutinated by the prototype strains for adenovirus types 1, 2, 4, 5, 6, 8, 9 and 10 but not by types 3 and 7. Clear hemagglutination was observed without heterotypic antiserum by the microplate technique. No significant difference was observed in the hemagglutination titer using two strains of mice. Adenoviruses were identified by the hemagglutination inhibition test, using mouse erythrocytes and prototype strains 1, 2, 4, 5, 6 and 8. The use of mouse erythrocytes for typing adenoviruses is recommended.

Hematology and clinical chemistry reference values for C57BL/6 X DBA/2 F1 mice.

We have analyzed hematology data from 504 individual male C57BL/6 X DBA/2 (hereafter called B6D2F1) mice. Clinical chemistry data from an additional 304 individual male B6D2F1 mice have also been analyzed. The mice had served as drug-diluent controls in 24 toxicological evaluations of anticancer drugs administered singly or in combination. The studies were carried out under standardized conditions during an 18-month period between July 1975 and December 1976. Test values corresponding to 9 percentiles have been selected from an ordered ranking of values for each of 18 hematologic tests and 18 clinical chemistry tests. Since 95% of the values for a given test are found between the 2.5th and 97.5th percentiles, test values corresponding to these percentiles provide reference values ("normal" values) for these mice. The other percentiles (5th, 10th, 25th, 50th, 75th, 90th, and 95th) indicate the distribution of values between the reference limits for each test. Since values for all tests do not conform to the Gaussian distribution, this nonparametric analysis provides reference values that are more accurate than might be obtained from calculation of the mean and standard deviation of a given test. The B6D2F1 mouse, commonly referred to as BDF1, has been widely used for preclinical evaluation of anticancer drugs, and these data should be useful to investigators who are conducting qualitative and quantitative toxicity evaluations in these mice.

Developmental changes in serum luteinizing hormone, follicle stimulating hormone and androgen levels in males of two inbred mouse strains.

A comprehensive developmental study of serum LH, FSH and androgen concentrations was carried out in male mice of two inbred strains. Gonadotropic hormone (GTH) levels rose 10-15 days prior to the pubertal increase in serum androgen with FSH preceding LH in this regard. In both strains GTH titer rose to a peak at 30 or 35 days and then steadily declined to adult levels which were strain-specific. Serum androgen was detected at low, relatively steady levels until the pubertal increase between 30 and 50 days postpartum. The results are interpreted as supporting the hypothesis that a shift in feedback sensitivity, occurring at about 20 days of age, may be involved in the onset of puberty in the male mouse.

Prolactin and growth hormone levels in different inbred strains of mice: patterns in association with estrous cycle, time of day, and perphenazine stimulation.

These experiments were designed to compare prolactin (PRL) and growth hormone (GH) secretion in strains of mice with varying incidences of mammary tumors. In addition to the basal levels, PRL concentrations were compared after stimulation with perphenazine. Although pituitary concentrations of PRL and pituitary serum concentrations of GH appeared to be generally higher in strains with high incidence of mammary tumors, basal PRL levels in single decapitate serum samples seemed to have little correlation with the incidence of mammary tumors in different strains. However, PRL concentrations in sera after perphenazine injection followed a pattern characteristic of the mammary tumor incidence rate of the strain: C3H/St and CBA/St--the two high-incidence strains--had lower levels of PRL; C57BL/St and BALB/cST--the two low-incidence strains--had higher levels; and DBA/2St--the medium-incidence strain--had an intermediate level. PRL contents of the pituitary glands were depleted virtually equally in all strains except the BALB/cSt. These results suggested that the rate of metabolism of PRL in strains with high incidence of mammary tumors may be faster than in those with low incidences. Perphenazine had no influence on GH secretion in most mice. The strain-specific differences in PRL and GH concentrations were usually present even during cyclical and diurnal fluctuations. Serum PRL and GH levels were generally higher during the follicular phase and lower during the luteal phase of the estrous cycle in both C3H/St and C57BL/St strains. There were signs of episodic secretion of PRL together with evidences of circadian periodicity in the secretion of PRL and GH in mice of both strains. The levels of GH were usually high during the morning hours of those of PRL high during the evening hours. The data show a high degree of specificity in the secretion of PRL and GH im mice of different inbred strains, and it is possible that these strain-specific differences may be an important factor in the development of mammary tumors.