Effects of CuDIPS and tween 80 on SJL/J tumorigenesis

Plasma copper and zinc levels were measured in SJL/J mice, an inbred strain characterized by a high, spontaneous incidence of reticulum cell sarcoma (RCS). The changes with age in mean concentrations of these metals were consistent with a physiological response that is required for remission of neoplasia. Treatment of SJL/J mice with a copper complex, Cu(II)(3,4-diisopropylsalicylate)₂ (Cu 3,5-DIPS), dissolved in a 10% Tween 80-saline solution revealed a decrease in survival and decline in the incidence of RCS at 52 wk of age. The toxic effects of Cu 3,5-DIPS therapy appeared to be related to the intraperitoneal route of administration and to extracellular deposition of collagen. The inhibitory effect on tumor development was not related to Cu 3,5-DIPS. Rather, Tween 80 was found to be the factor of importance.     

Effects of degranulation of mast cells on proliferation of mesenchymal cells in the mesentery of mice

Summary A mast-cell activator, compound 48/80, causes proliferation of mesenchymal cells in the mesentery of rats. Its effect on W/W ^vmice deficient in mast cells was tested to determine whether the proliferation is mediated in the degranulation of mast cells. Incorporation of [³H]thymidine into mesenchymal cells in the mesentery of these mice with or without compound 48/80 was very small compared to their normal litter mates. However, bone marrow transplantation markedly enhanced the effect of compound 48/80, and resulted in an incorporation of [³H]thymidine almost comparable to that observed in normal mice. Our results provide evidence that mesenchymal cell proliferation is caused by a product secreted by mast cells when stimulated by compound 48/80.Supported by a Grant-in-Aid for Scientific Research, No. 366, from the Japanese Ministry of Health and WelfareThe authors are indebted to Drs. Motomu Minamiyama and Yukio Hirata for valuable advices, and to Miss Mitsuko Inoue for technical assistance     

Effect of alpha-fluoromethylhistidine on the histamine content of the brain of W/Wv mice devoid of mast cells: turnover of brain histamine

In the brains of W/Wv mutant mice that have no mast cells, the histidine decarboxylase (HDC) level is as high as in the brain of congenic normal mice (+/+), but the histamine content is 53% of that of +/+ mice. The effects of alpha-fluoromethylhistidine (alpha-FMH) on the HDC activity and histamine content of the brain of W/Wv and +/+ mice were examined. In both strains, 30 min after i.p. injection of alpha-FMH the HDC activity of the brain had decreased to 10% of that in untreated mice. The histamine content decreased more gradually, and after 6 h about half of the control level remained in +/+ mice, whereas histamine had disappeared almost completely in W/Wv mice. It is concluded that the portion of the histamine content that was depleted by HDC inhibitor in a short time is derived from non-mast cells, probably neural cells. The half-life of histamine in the brain of W/Wv mice was estimated from the time-dependent decrease in the histamine content of the brain after administration of alpha-FMH: 48 min in the forebrain, 103 min in the midbrain, and 66 min in the hindbrain.     

Elevated specific activity of 5′-nucleotidase in a spinal cord myelin fraction from shiverer mice comparison with other myelin-associated enzymes and myelin proteins

Meylin partially purified from spinal cords of dysmyelinating mutant (shiverer) mice had almost three-fold the specific activity of 5′-nucleotidase found in the respective myelin fraction from normal mice. The specific activities of two other normally myelin-associated enzymes, 2′,3′-cyclic nucleotide-3′-phosphohydrolase and carbonic anhydrase, were only slightly higher in the myelin membranes from shiveres, compared to those from controls. In the mutants, the three enzymes probably occur in oligodendrocyte processes. Hhypothetically, the 5′-nucleotidase in the myelin sheath in shiverer and normal mice may be localized in specialized structures.     

Failure of spermatozoa from T/t mice to fertilize in vitro is overcome by zona drilling

Failure of epididymal spermatozoa from T/t mutant mice, but not from t/t individuals, to fertilize oocytes in vitro was partially overcome by opening a small aperture in the zona pellucida with acidified Tyrode's solution to permit direct access of the spermatozoon to the vitellus. This study provides a model system to evaluate requirements for successful zona drilling in the treatment of human infertility and further insights into the effects of the t complex on sperm fertility.     

Intraspecific evolution of a gene family coding for urinary proteins

Summary The genome of the laboratory mouse contains about 35 major urinary protein (MUP) genes, many of which are clustered on chromosome 4. We have used distance and parsimony methods to estimate phylogenetic relationships between MUP genes from nucleotide sequence and restriction maps. By analyzing coding sequences we show that the genes fall into four main groups of related sequences (groups 1–4). Comparisons of restriction maps and the nucleotide sequences of hypervariable regions that lie 50 nucleotides 5 to the cap sites show that the group 1 genes and probably also the group 2 pseudogenes fall into subgroups. The most parsimonious trees are consistent with the evolution of the array of group 1 and 2 genes by mutation accompanied by a process tending toward homogenization such as unequal crossing-over or gene conversion. The phylogenetic grouping correlates with grouping according to aspects of function. The genomes of the inbred strains BALB/c and C57BL contain different MUP gene arrays that we take to be samples from the wild population of arrays.     

In vitro development of one-cell embryos from outbred mice: Influence of culture medium composition

Summary One-cell embryos from outbred mice (CF1, CD-1, and Dub:ICR) were cultured in various modifications of egg culture medium (ECM). The best development was observed in medium in which inorganic salts of modified T6 medium (mT6) replaced those of ECM. In this modification (TE), 66% of one-cell CF1 embryos developed into blastocysts, comared to 46 and 43% for ECM and mT6, respectively. Moreover, the cell numbers of blastocysts developing in TE (74.9±3.3) were higher than the cell numbers of those developing in ECM (55.1±2.4). The culture requirements of embryos varied between different stocks of mice: Fewer CF1 embryos developed to the blastocyst stage than either Dub:ICR embryos (90%) or CD-1 embryos (84%). Lowering the osmolarity of the medium from 300 to 280 mOsm, increasing the concentration of KC1 from 1.42 to 25 mM, or omitting lactate from the medium during Day 1 of culture did not further improve development of embryos, in contrast to previous reports. However, the time at which embryos were transferred to outgrowth medium influenced their postblastocyst development. The best development was observed when embryos were transferred on Day 4 of culture at the late morula-early blastocyst stage. This work was supported by the Office of Health and Environmental Research, U.S. Department of Energy, Washington, DC, contract DE-AC03-76-SF01012.     

Spectral sensitivity of photoreceptors mediating phase-shifts of circadian rhythms in retinally degenerate CBA/J (rd/rd) and normal CBA/N (+/+) mice

Light-dark cycles are the most important time cue for the circadian system to entrain the endogenous circadian clock to the environmental 24 h cycle. Although photic entrainment of circadian rhythms is mediated by the eye in mammals, photoreceptors implicated in circadian photoreception remain unknown. In our previous study, retinally degenerate CBA/J (rd/rd) mice were found to have lower circadian photo-sensitivity for phase-shifting the locomotor activity rhythms than normal CBA/N(+/+) mice. In the present study, the spectral sensitivity for phase-shifting the rhythms was examined in order to characterize the photopigments involved in circadian photoreception of these mice. The spectral sensitivity of CBA/J-rd/rd mice clearly fitted to the Dartnall nomogram for a retinal₁-based pigment with a maximum at 480 nm, while the best fitted nomogram had a maximum at 500 nm in CBA/N- +/+ mice. These results suggest that circadian photopigments involved in CBA/J-rd/rd and CBA/N- +/+ mice may be different.     

Utilization of Iron Sources and Its Possible Roles in the Pathogenesis of Vibrio parahaemolyticus

Vibrio parahaemolyticus is an important enteropathogen in Japan, Taiwan and other coastal regions. The influence of the regulation of iron on the pathogenesis of this pathogen has not been well characterized. The growth of pathogenic and non-pathogenic strains of V. parahaemolyticus on iron-limited agar plates was stimulated by ferritin, lactoferrin and transferrin at 30 μM , and also by hemin, hemoglobin and ferric ammonium citrate at 100 μM . Spontaneous iron-utilizing mutant strains (mutants) were derived from a clinical strain, ST550. Compared with the parent strain, lowered virulence was demonstrated for these mutants, as assayed by adult mouse and suckling mouse models. The in vivo growth and enterotoxigenicity of these mutants were also lower in the suckling mice. Adherence of the mutants to excised mouse intestine was lower as demonstrated by scanning electron microscopy. The iron-regulated outer membrane protein profile also changed in selected mutants. These results indicate that iron-regulated outer membrane proteins and other unknown factors associated with iron utilization may have profound influences, besides iron acquisition, on the pathogenesis of V. parahaemolyticus.     

The 21-aminosteroid U-74389F increases the number of glial fibrillary acidic protein-expressing astrocytes in the spinal cord of control and wobbler mice

Summary 1. Wobbler mice suffer an autosomal recessive mutation producing severe motoneuron degeneration and dense astrogliosis, with increased levels of glial fibrillary acidic protein (GFAP) in the spinal cord and brain stem. They have been considered animal models of amyotrophic lateral sclerosis and infantile spinal muscular atrophy. 2. Using Wobbler mice and normal littermates, we investigated the effects of the membrane-active steroid Lazaroid U-74389F on the number of GFAP-expressing astrocytes and glucocorticoid receptors (GR). Lazaroids are inhibitors of oxygen radical-induced lipid peroxidation, and proved beneficial in cases of CNS injury and ischemia. 3. Four days after pellet implantation of U-74389F into Wobbler mice, hyperplasia and hypertophy of GFAP-expressing astrocytes were apparent in the spinal cord ventral and dorsal horn, areas showing already intense astrogliosis in untreated Wobbler mice. In control mice, U-74389F also produced astrocyte hyperplasia and hypertophy in the dorsal horn and hyperplasia in the ventral-lateral funiculi of the cord. 4. Givenin vivo U-74389F did not change GR in spinal cord of Wobbler or control mice, in line with the concept that it is active in membranes but does not bind to GR. Besides, U-74390F did not compete for [³H]dexamethasone binding when addedin vitro. 5. The results suggest that stimulation of proliferation and size of GFAP-expressing astrocytes by U-74389F may be a novel mechanism of action of this compound. The Wobbler mouse may be a valuable animal model for further pharmacological testing of glucocorticoid and nonglucocorticoid steroids in neurodegenerative diseases.