Protection from Fas-mediated apoptosis by a soluble form of the Fas molecule

Fas is an apoptosis-signaling receptor molecule on the surface of a number of cell types. Molecular cloning and nucleotide sequence analysis revealed a human Fas messenger RNA variant capable of encoding a soluble Fas molecule lacking the transmembrane domain because of the deletion of an exon encoding this region. The expression of soluble Fas was confirmed by flow cytometry and immunocytochemical analysis. Supernatants from cells transfected with the variant messenger RNA blocked apoptosis induced by the antibody to Fas. Levels of soluble Fas were elevated in patients with systemic lupus erythematosus, and mice injected with soluble Fas displayed autoimmune features.

The impact of maternal history and behavior upon foster placement and adjustment in sexually abused girls

This study investigated the impact of the nonoffending mother's childhood history and current functioning upon the psychological status and placement decisions for 68 sexually abused girls. Maternal history of abuse and/or poor childhood attachment relationships were significantly related to current maternal substance abuse. Maternal substance abuse and dissatisfaction with social support were significantly associated with lack of maternal support to the child and more abuse incidents, which in turn were related to more sexual abuse-related symptomatology and placement in foster care. The findings are congruent with studies indicating that intergenerational transmission of abuse is not inevitable, and suggest that maternal substance abuse and social isolation are important mediating variables between maternal history of sexual abuse and response to the abused child. The findings suggest that interventions targeted to the nonoffending mothers may be important in reducing child dysfunction and placement in foster care in the aftermath of sexual abuse.

Apoptosis in C3H/10T1/2 mouse embryonic cells: evidence for internucleosomal DNA modification in the absence of double-strand cleavage

Apoptosis in embryonic C3H/10T1/2 (clone 8) cells is marked by specific changes in morphology and DNA fragmentation that differ from those found in apoptotic thymocytes. These results demonstrate that ultrastructural changes within the nucleus associated with endonucleolytic degradation are linked with structural degradation at higher levels of chromatin organization. Strand modifications within the internucleosomal linker region are shown to involve alkaline-sensitive sites that appear to be sensitive to S1 endonuclease. Our results suggest that apoptosis is not dependent upon internucleosomal cleavage and may reveal the penultimate step and the nature of the metabolic cascade that leads to cell death.

Quantitative fluorometric analysis of plant and microbial chitosanases

A quantitative fluorometric assay for chitosanase activity in bacterial and plant tissues was developed. The assay can be conducted with either finely milled preparations of chitosan in suspension or dissolved chitosan; activity is based on measurements of glucosamine (GlcN) or oligomers of GlcN. GlcN is detected fluorometrically after reaction with fluorescamine with detection in the nanomole range. Fluorescence measurements of chitosanase activity and radioassay of chitinase in commercial preparations of chitinase from Streptomyces griseus revealed that both activities were present. Specific activities for the S. griseus chitosanase using suspended and soluble chitosans were respectively 1.24 and 6.4 mumol GlcN.min-1.mg protein-1. Specific activity of the S. griseus chitinase was 0.98 mumol GlcN.min-1.mg protein-1. Sweet orange callus tissue was tested for chitosanase and chitinase activity. It was necessary to remove small amine-containing molecules from the callus preparations before chitosanase activity could be assayed. The specific activity for chitinase and chitosanase in desalted extracts of nonembryogenic Valencia sweet orange callus tissue was determined to be 18.6 and 89.4 nmol GlcN.min-1.mg protein-1, respectively.

Rorschach assessment of psychological functioning in sexually abused girls

We measured psychological functioning in a group of 79 Black females between the ages of 5 and 16 and a comparison group of nonabused girls using the Rorschach. In addition to Exner's (1985) Comprehensive System, the Elizur (1949) Rorschach Content Test Scale (RCT), the Mutuality of Autonomy Scale (MOA; Urist, 1977; Urist & Shill, 1982), and the Barrier and Penetration Scales (Fisher & Cleveland, 1968) were used. Sexually abused girls were found to show more disturbed thinking, to experience a higher level of stress relative to their adaptive abilities, to describe human relationships more negatively, and to show more preoccupation with sexuality than the comparison group. The distress experienced by the victimized children was more related to internal mediating variables then to abuse characteristics. Sexually abused girls who are cognitively and emotionally active also experienced high levels of distress compared to abused girls who are psychologically constricted.

Multimethod assessment of depression in sexually abused girls

This study measured depression in sexually abused Black girls using the Children's Depression Inventory (Kovacs & A. T. Beck, 1977), the Internalization scale of the Child Behavior Checklist (Achenbach & Edelbrock, 1983), and the Rorschach Depression Index (Exner, 1986). There were no significant correlations between these self-report, behavior observation (by parental report), and projective measures. The abused subjects had high scores on the behavior observation and Rorschach scales. Consistent with past research, negative results were obtained with the self-report instrument. We suggest that the low scores on self-report measures of distress produced by sexually abused children may be the result of guardedness or defensiveness rather than a genuinely low level of dysphoria in this population. There were no significant relations between abuse characteristics and scores on the depression measures. Scores on Rorschach measures of organizational activity (Zf) and available coping resources (EA) were generally positively related to depression within the abuse group and negatively related to depression within the control group.

Relationships between dimensions of depressive experience and perceptions of the lives of people in general

This study examines relationships between depression and perceptions of the lives of people in general. One hundred fourteen college students completed the Center for Epidemiological Studies Depression Scale (Radloff, 1977), the Depressive Experiences Questionnaire (Blatt, D'Afflitti, & Quinlan, 1976), and two instruments that asked subjects to make judgments about the frequency of various positive and negative outcomes in other people's lives. Highly Dependent and highly Self-Critical women perceived people's lives as characterized by much misfortune, failure, and unhappiness. Unexpectedly, Efficacy scores, which are negatively related to depression, were also associated with negative perceptions of people's lives in women. Among the men, overall depression was not related to perceptions of how frequently people succeed at specific, concrete life tasks, but depressed subjects perceived others as experiencing a low level of subjective well-being. Implications for the notion of a depressive negative bias toward the self are discussed.

Two kinds of identity crisis

In order to outline a model of identity crisis, it is necessary to distinguish two types. In an identity deficit ("motivation crisis"), the individual experiences a lack of guiding commitments but struggles to establish personal goals and values. In an identity conflict ("legitimation crisis"), the person has several commitments which prescribe conflicting behavioral imperatives in some situations, such that at least one commitment may have to be betrayed. The literature on identity crisis is reviewed in connection with this distinction, and an attempt is made to delineate the causes, the subjective experiences, behavioral consequences, and modes of resolution of each type of crisis.

Insect apolipophorin III. Purification and properties

The hemolymph of adult Manduca sexta (tobacco hornworm) contains a 17,000-dalton protein that can associate reversibly with the insect lipoprotein lipophorin. The protein is abundant in the hemolymph of the adult, but is found in larval hemolymph in only small amounts, and does not associate with larval lipophorin. On the basis of its association with adult lipophorin, we have designated the protein apolipophorin III. Apolipophorin III was dissociated from adult lipophorin by guanidinium chloride treatment and isolated by gel permeation and ion exchange chromatography. The unassociated apolipophorin III was also purified from lipophorin-free hemolymph by gel permeation, ion exchange, and lectin chromatography. Both preparations have identical isoelectric points and amino acid composition as well as the following properties. Apolipophorin III is a non-glycosylated polypeptide lacking cysteine and tryptophan. The 17,000-dalton polypeptide dimerizes in solution to a protein of Mr = 34,000.

Structural studies on lipophorin, an insect lipoprotein

An insect high density lipoprotein, lipophorin, can be rapidly isolated from larval Manduca sexta (tobacco hornworm) hemolymph by single vertical spin density gradient ultracentrifugation. The two apolipoproteins (Mr = 245,000 and 78,000; designated apoLp-I and apoLp-II, respectively) were readily dissociated and separated in 6 M guanidine HCl by gel permeation chromatography. ApoLp-I and apoLp-II showed no immunological cross-reactivity on electrophoretic blots of sodium dodecyl sulfate-polyacrylamide gels. ApoLp-I and apoLp-II from lipophorin of adult M. sexta behaved identically to their larval counterparts. Amino acid compositions of larval apoLp-I and apoLp-II were similar except with respect to tryptophan and cysteine; apoLp-I contained 32 residues/mol of tryptophan (1.5 mol%) and 22 residues/mol (1.1 mol%) of cysteine; apoLp-II contained 2 residues/mol of tryptophan (0.2 mol%) and 14 residues/mol of cysteine (2.1 mol%). In double immunodiffusion tests, antiserum against apoLp-I or whole lipophorin strongly precipitated lipophorin, while antiserum against apoLp-II caused only minor precipitation. This indicates relatively greater exposure of apoLp-I to the aqueous environment.

Viewpoint: a triumvirate plus one of deans--a new model for health school administration

In a triumvirate plus one, the dean serving as chair could direct school resources for special areas, and emphasis could thereby be given to new programs or directions. Each year, the chair would rotate to a dean in the triumvirate who would assume overall direction of the program.

Locust adipokinetic hormone stimulates lipid mobilization in Manduca sexta

Adipokinetic hormone, a decapeptide isolated from the locust, stimulates mobilization of diacylglycerols from the locust fat body and loading of the lipid transport protein, lipophorin. Injection of the synthetic locust adipokinetic hormone into a sphinx moth, Manduca sexta, causes lipid loading of lipophorin. The lipophorin decreases in density from 1.11 to 1.06 g/ml, and a soluble protein from the hemolymph (apolipophorin III) associates with the lipophorin particle. Administration of intermediate doses of hormone indicates that lipophorin is converted directly to the low density form; no appreciable amounts of intermediate density particles are formed.