A transgenic mouse strain expressing four drug-selectable marker genes

Murine embryonic stem (ES) cells are commonly cultured on feeder layers of primary murine embryonic fibroblasts (MEFs). Because gene targeting experiments often involve sequential selection for multiple-drug resistance in single ES cell lines, we have developed a new mouse strain which represents an economical donor for the production of multiple-drug resistant MEFs. MEFs prepared from the DR-4 mouse strain displayed resistance to concentrations of the drugs G418, 6-thioguanine, puromycin and hygromycin well above those used normally for the selection of drug-resistant ES cells.     

弦式应变计设计及应用

文章介绍弦式应变计的工作原理及其设计特点．试验表明，这种应变计能可靠地应用于检测结构变形引起的应力．     

Social-cognitive and behavioral characteristics of peer-rejected boys.

Identified 13 rejected and 13 popular 3rd- and 4th-grade boys using sociometric nomination measures. Playground observations and interview assessments of social problem solving were administered during the winter and spring. Rejected Ss both exhibited and received more aversive behavior than popular Ss. Although no status differences in the overall rate of interaction were found, rejected Ss exhibited more onlooker behavior and solitary play than the popular ones. No differences in the frequency of alternative solutions to hypothetical social problems were found between status groups. The solutions of rejected Ss were, however, less effective and more aggressive than those of populars. Chosen solutions of rejected Ss were also more likely to be ineffective and aggressive than those of populars. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Bulimia and binge eating in college women: A comparison of personality and behavioral characteristics.

Assessed 9 behavioral and personality characteristics—restraint, binge eating, high self-expectations, demand for approval, body attitude, assertion, dating, self-esteem, and depression—that have been implicated in studying the onset of bulimia. Ss were 30 women who fulfilled an operationalized definition of the DSM-III criteria for bulimia (bulimics), 22 women who reported binge eating 8 or more times per month but did not fulfill the criteria for bulimia (binge eaters), and 28 women who did not binge eat (controls). Ss completed measures that included the Beck Depression Inventory, a self-esteem index, and the short form of the Personality Attributes Questionnaire. In comparison to controls, bulimics were more depressed and had lower self-esteem, poorer body image, higher self-expectations, higher need for approval, greater restraint, and higher binge-eating scores. Binge eaters exhibited higher restraint and binge-eating scores than controls. Bulimics and binge eaters differed significantly on all but a few variables. Results suggest that treatment for bulimics should extend beyond the disturbed eating pattern and that the distinction between binge eating and bulimia is an important one. Some empirical support for the DSM-III definition of bulimia was found. (31 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Finding the self: A behavioral measure and its clinical implications.

Presents a clinical model of the development of self. The model focuses on the early learning responsible for linguistic self-referents such as I and me. This model offers an account for why some patients, such as those with borderline personality disorder (BPD), feel that they do not know who they are or that their sense of self is controlled by other people, while other patients have a sense of a secure, stable self that is not prey to the whims of others. The authors administered the Experiencing of Self Scale, which measures the degree to which other people influence the experience of self, along with the Self-Esteem Scale and the Dissociative Experiences Scale to 284 undergraduate students (mean age 19.2 yrs) and 14 BPD patients (mean age 41.1 yrs). Results show that the degree to which other people influence the experience of self depended on the nature and closeness of the people involved, that those in the BPD sample suffered from excessive influence of other people over the experience of self relative to the undergraduates, and that the degree of influence correlated predictably with high dissociation and low self-esteem. Implications for conceptualizing BPD and narcissistic personality disorder are discussed, and clinical applications are suggested. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A test for specific and general behavioral effects of infantile stimulation with shock in the mouse.

The hypothesis tested was that exposure of the infant mouse to shock which could not be terminated by some specific response would lead to greater fearfulness later on than exposure to shock whose termination was contingent on a specific response. 3 groups of mice 8 to 11 days of age were each subjected to different shock conditions. One group could terminate the shock by an avoidance response (response-contingent group), one group had no control over the duration of shock (arbitrary shock group), and the third group received no shock in the apparatus. Later an open-field test of emotionality showed no significant differences, but an adult avoidance learning test showed that the run times of the response-contingent group were significantly shorter than those of the no-shock group. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Codependency in nursing students: recognition and modification of behavioral characteristics

Recent literature estimates that there are approximately 2 1/2 million nurses; of these a significant number may exhibit signs of codependency, a behavior pattern that impedes an individual's ability to relate to others on mature level. Codependency develops in dysfunctional family systems and manifests itself in compulsive behaviors that make life painful and work emotionally difficult. Often, constructive communication is difficult as codependent persons tend to feel low self-esteem and low self-worth. Nursing students may exhibit characteristic codependency traits among fellow students in the classroom, in the clinical setting, and in interactions with faculty. Nurse educators, through their own self-awareness, introspection, and knowledge of the behaviors and characteristics of codependency, can facilitate more effective communication with all nursing students to promote healthier interactions and relationships. Techniques to modify one's method of interacting with others have clear potential for improving professional as well as personal relationships.     

A mouse mutant strain highly resistant to methyl beta-carboline-3-carboxylate-induced seizures

It is believed that DOPA-negative melanocytes in the outer root sheath of the human hair follicle are activated, become identifiable by DOPA staining, and migrate into the epidermis during the repigmenting phase of vitiligo. These cells are difficult to identify, however, and otherwise have not been characterized. These cells are readily identified by immunofluorescence, immunohistochemistry, and immunoelectronmicroscopy using the antibodies NKI/beteb and A4F11, which recognize premelanosome-related antigens. The majority of the outer root sheath melanocytes were found in the mid to the upper portion of the hair follicle. Double staining revealed that these cells were distinct from HLA-DR-bearing dendritic cells. Further immunohistochemical investigation using alpha-PEP-7, alpha-PEP-1, or TMH-1 and alpha-PEP-8 antibodies revealed that outer root sheath melanocytes cannot be identified by antibodies to tyrosinase, TRP-1, or TRP-2, respectively. These cells also did not react with HMB45 antibody, which recognizes a melanosome-associated cytoplasmic antigen. We believe that the inactive outer root sheath melanocytes contain some of the early structural proteins but not any of the enzymatic proteins necessary for melanogenesis. Therefore, activation is the process whereby outer root sheath melanocytes acquire all of the structural and enzymatic proteins necessary for melanogenesis.     

Cognitive and behavioral characteristics of physically abused children.

Compared 11 physically abused males (aged 3 yrs 11 mo to 5 yrs 8 mo) on the McCarthy Scales of Children's Abilities (MSCA) and the Wide Range Achievement Test with 10 nonabused males matched on age, family income, and maternal age and education. In addition, behavioral observations of their performance on a persistence task were coded. Significant differences were found on the Verbal and Memory Scales and the General Cognitive Index of the MSCA. No behavioral differences were noted. (2 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A structured observation of behavioral self-regulation and its contribution to kindergarten outcomes.

The authors examined a new assessment of behavioral regulation and contributions to achievement and teacher-rated classroom functioning in a sample (N = 343) of kindergarteners from 2 geographical sites in the United States. Behavioral regulation was measured with the Head-Toes-Knees-Shoulders (HTKS) task, a structured observation requiring children to perform the opposite of a dominant response to 4 different oral commands. Results revealed considerable variability in HTKS scores. Evidence for construct validity was found in positive correlations with parent ratings of attentional focusing and inhibitory control and teacher ratings of classroom behavioral regulation. Hierarchical linear modeling indicated that higher levels of behavioral regulation in the fall predicted stronger levels of achievement in the spring and better teacher-rated classroom self-regulation (all ps p     

Behavioural performance in three substrains of mouse strain 129

Recently, the possibility has been raised that the behavioural abnormalities seen in null-mutant mice might be determined by their genetic background rather than by loss of gene function, especially when the 129 mouse strain is used as supplier for embryonic stem (ES) cells. To examine this issue we tested three 129 mouse substrains (129/J, 129/Ola, 129/Sv-ter/+) and C57BL/6 (B6) in the Morris water maze, the open field, the plus maze and two tests assessing motor co-ordination. We identified only for the 129/J substrain substantial behavioural deficits. These mice are albinos and carry the pink-eyed dilution allele and differed in their basal anxiety level as assessed in the open-field test. They were severely impaired in spatial learning and memory (Morris water maze test), in the Porsolt swim test, which also measures learning and in motor co-ordination. However, the 129/J substrain has not been used as ES cell donor in null-mutant mice where behavioural abnormalities were observed. Instead, mice from 129/Ola and 129/Sv-ter/+ substrains have been commonly used as suppliers for ES cells. These performed normally in most of the tests, including Morris water maze test.     

Characteristics of age-related behavioral changes in senescence-accelerated mouse SAMP8 and SAMP10

Senescence-Accelerated Mouse (SAM), a murine model of accelerated senescence, has been established by Takeda et al. (1981). SAM consists of senescence-accelerated-prone mouse (SAMP) and senescence-accelerated-resistant mouse (SAMR), the latter of which shows normal aging characteristics. In 1991 there were eight different substrains in the P-series, which commonly exhibited accelerated aging with a shortened life span (Takeda et al., 1991). Among the P-series, we have found that SAMP8 mice show significant impairments in a variety of learning tasks when compared with SAMR1 mice (Miyamoto et al., 1986). Further studies suggest that SAMP8 exhibits an age-related emotional disorder characterized by reduced anxiety-like behavior (Miyamoto et al., 1992). On the other hand, it has been shown that SAMP10 exhibits brain atrophy and learning impairments in an avoidance task (Shimada et al., 1992, 1993). Here, characteristics of age-related deficits in learning and memory, changes in emotional behavior, and abnormality of circadian rhythms in SAMP8 and SAMP10 mice are described. In the experiments, SAMP8/Ta (SAMP8), SAMP10/(/)Ta (SAMP10) and SAMR1TA (SAMR1) reared under specific pathogen-free conditions at Takeda Chemical Industries were used.     

Hereditable characteristics of attenuated live hepatitis A virus H2 strain

The toxicity of attenuated hepatitis A virus H2 strain was not increased in testing KMB 17 cells of 5 consecutive generations of monkeys at 36 degrees C. After injection of attenuated live hepatitis A virus H2 strain in humans, no abnormality was noted. Serum hepatitis A antigen was positive after 38 children aged 3-9 years were given oral 10(6.5) TCKD50, whereas it was 100% positive in the group of same age after percutaneous vaccination. Noninfection of oral administration is an important hereditable characteristic differentiation from wild strains.     

Limb reduction defects in the A/J mouse strain associated with maternal blood loss

We previously described a high incidence of digit/limb anomalies in the offspring of A/J mice subjected to surgery on day 12.5 postconception (p.c.), but not in the offspring of untreated control mice. To investigate the cause of these defects, we compared the offspring of mice in experimental groups involving adrenalectomy, sham adrenalectomy, blood sampling, and anesthesia with the offspring of control mice. All treatments significantly reduced fetal weight and increased resorptions as compared with the controls. The highest incidence of digit anomalies occurred in the offspring of dams from which blood samples had been drawn on days 12.5, 14.5, and 15.5 p.c. The incidence of isolated cleft palate was also increased in the offspring of mice that had been subjected to blood sampling. We conclude that digit anomalies in the offspring of A/J mice result from fetal vascular disruptive phenomena subsequent to maternal blood loss induced hypovolemia and hypoperfusion to the uterus and placenta as has been suggested for uterine vascular clamping, misoprostol, chorionic villus sampling, and cocaine teratogenesis. The etiology for cleft lip in these mice may involve mechanisms unrelated to uterine/placental hypoperfusion.     

A standardized mouse model of Helicobacter pylori infection: introducing the Sydney strain

BACKGROUND & AIMS: Currently available Helicobacter pylori models show variable and, in some instances, poor colonization. There is a need for a strain with high colonizing ability to act as a standard for animal studies. METHODS: After screening a range of fresh clinical isolates and long-term adaptation in mice, a strain of H. pylon has been isolated with a very good colonizing ability. RESULTS: This strain, named the Sydney strain of H. pylori (strain SS1), is cagA and vacA positive. High levels of colonization (10(6)-10(7) colony-forming units/g tissue) were achieved consistently in C57BL/6 mice. Colonization levels varied depending on the mouse strain used with BALB/c, DBA/2, and C3H/He, all being colonized but in lower numbers. In all strains of mice, bacteria were clearly visible at the junctional zone between the antrum and the body. The phenotype was stable with colonizing ability remaining after 20 subcultures in vitro. The bacterium attached firmly to gastric epithelium. During 8 months, a chronic active gastritis slowly developed, progressing to severe atrophy in both C57BL/6 and BALB/c mice. CONCLUSIONS: The Sydney strain of H. pylori is available to all and will provide a standardized mouse model for vaccine development, compound screening, and studies in pathogenesis.     

Study of functional characteristics of brain neurons in behavioral experiment

The work of the central integrative neurons of the brain is concerned with the total evaluation of the heterogeneous signals and signals of different sensory modality, coming to these neurons via the parallel inputs. Due to the processing of this information central neurons participate in organization of the different acts of animal and in mechanisms of switching from one action to another. Therefore, to define what role the neuron plays in the behavior organization it is necessary to analyse dynamics of unit activities continuously during the all successively performed animal's actions. The traditional methods, such as post- and peristimlus histograms and crosscorrelation are not effective enough for this aim. They are useful for the analysis of the spikes that are situated close to the synchronizing signal only. The application of these methods for the study of unit activity related to extended behavioral program inevitably leads to creation of histograms for each action separately. Such sets of histogram do not reflect the real dynamics of neuronal activity corresponding to the continuum of the behavior. A complex approach is proposed for the study of neuronal correlates of behavior directed towards overcoming of the mentioned difficulties. This approach includes multicomponent behavioral program, recording o spikes in several units in parallel and analysis of unit activities in relative time scale, based on duration of each of the successively performed by the animal action. The nontraditional methods of the processing of spikes sequences are elaborated, such as relative time histograms and methods of the multivariate statistics. The realized on this principles analysis gives a full impression about neuronal activities uninterruptedly, during all stages of performance of the extended behavioral program. The described methods were approved in the experimental study of the functional characteristics of the striatal units in monkeys. The comparable data were obtained on the individual reactions of neurons and dynamics of their activities in group during the performance of behavior program. These data revealed lack of functional specialization of the striatal neurons and different forms of their involvement in the motor and cognitive functions.     

Cognitive, adaptive, and behavioral characteristics of Williams syndrome

The difference of morphological injury between rabbit aorta and pulmonary artery was compared after the animal was exposed to the altitude 5 km (PO2 = 10.8 kPa) for 24 h. Hypoxia caused subendothelial edema, increased vacuoles and injured mitochondria and endoplasmic reticulums in both kinds of endothelial cells. The impairment of pulmonary artery was obviously more severe than aorta and its smooth muscle cells were also affected. Forthermore, the exposure increased mitochondria in pulmonary artery endothelial cells. Bubbled with a mixture air of 95% N2-5% CO2 (PO2 = 4 kPa) led to an increase of pulmonary in tension, while hypoxia to the same extent induced aorta relaxation. These results indicate that hypoxia produces the differential effects on these two kinds of vessels, providing a possible explanation for the production of hypoxic pulmonary hypertension.     

Strain hardening at high strain in aluminum alloys and its effect on strain localization

The modes of strain localization in the tensile testing of a sheet sample are diffuse necking, localized necking and, in some materials, localization in an unstable shear band. In a tensile test of a rate insensitive material, the normalized strain hardening parameter,H = (1/σ)(dσ/dε) has the values ofH = 1 for diffuse necking andH = 0.5 for localized necking. Curves ofH vs strain were obtained up to large values of plastic strain using the hydraulic bulge test. The materials selected were commercially important sheet alloys in the condition normally used for forming. It is shown that the materials have similarH vs strain curves in the range of uniform tensile straining, but the curves diverge widely at higher strains whereH falls below 1. This has important consequences on strain localization behavior. The limit strains of the alloys in simple tension and punch stretching show reasonable correlation with their values ofH and those alloys which are susceptible to catastrophic shear failure have low values ofH at high strains. Strain rate sensitivity adds to or subtracts from theH values obtained in this study and has an additional influence on strain localization. Formerly with Alcoa Laboratories, Alcoa Center, PA 15069, U.S.A     

Transplacental cocaine exposure: a mouse model demonstrating neuroanatomic and behavioral abnormalities

Between 10% and 15% of infants born in urban America today have been exposed to cocaine in utero. Clinical studies have suggested that impairment of brain growth is the single best marker of significant prenatal cocaine exposure, and postnatal developmental compromise seen in a subset of affected children as a consequence of that exposure. We have developed an animal model, in mice, of prenatal cocaine exposure that has allowed us to dissociate the direct effects of cocaine in altering fetal development from the indirect effects associated with cocaine-induced malnutrition. We find that transplacental cocaine exposure independently impairs fetal brain and body growth and results in behavioral deficits and permanent alterations in neocortical cytoarchitecture in exposed offspring.     

Olfactory denervation: its biological and behavioral effects in infant rats

Two-week-old infant rats were treated with intranasal ZnSO4 and compared with littlemate controls 24 hr later. When infants were returned to their mother and littermates, those with olfactory deficits lost weight, had reduced cardiac and respiratory rates and lower body temperatures, and showed increased locomotor behavior in an unfamiliar test area. Subsequent experiments showed that in the absence of the mother and also in isolation, differences between ZnSO4-treated and control infants involved fewer systems were less marked, and presented different patterns. Isolated infants given oral ZnSO4 did not differ from controls on any measures. Olfactory denervation appears to produce these effects by disrupting nursing, by altering littermate interaction, and by other central nervous system effects that are independent of social interaction.