CD22L Conjugation to Insulin Attenuates Insulin-Specific B Cell Activation

Pancreatic islet-reactive B lymphocytes promote Type 1 diabetes (T1D) by presenting an antigen to islet-destructive T cells. Teplizumab, an anti-CD3 monoclonal, delays T1D onset in patients at risk, but additional therapies are needed to prevent the disease entirely. Therefore, bifunctional molecules were designed to selectively inhibit T1D-promoting anti-insulin B cells by conjugating a ligand for the B cell inhibitory receptor CD22 (i.e., CD22L) to insulin, which permit these molecules to concomitantly bind to anti-insulin B cell receptors (BCRs) and CD22. Two prototypes were synthesized: 2:2 insulin-CD22L conjugate on a 4-arm PEG backbone, and 1:1 insulin-CD22L direct conjugate. Transgenic mice (125TgSD) expressing anti-insulin BCRs provided cells for in vitro testing. Cells were cultured with constructs for 3 days, then assessed by flow cytometry. Duplicate wells with anti-CD40 simulated T cell help. A 2-insulin 4-arm PEG control caused robust proliferation and activation-induced CD86 upregulation. Anti-CD40 further boosted these effects. This may indicate that BCR-cross-linking occurs when antigens are tethered by the PEG backbone as soluble insulin alone has no effect. Addition of CD22L via the 2:2 insulin-CD22L conjugate restored B cell properties to that of controls without an additional beneficial effect. In contrast, the 1:1 insulin-CD22L direct conjugate significantly reduced anti-insulin B cell proliferation in the presence of anti-CD40. CD22L alone had no effect, and the constructs did not affect the WT B cells. Thus, multivalent antigen constructs tend to activate anti-insulin B cells, while monomeric antigen-CD22L conjugates reduce B cell activation in response to simulated T cell help and reduce pathogenic B cell numbers without harming normal cells. Therefore, monomeric antigen-CD22L conjugates warrant futher study and may be promising candidates for preclinical trials to prevent T1D without inducing immunodeficiency.

Multivalent Scaffolds to Promote B cell Tolerance

Autoimmune diseases are characterized by aberrant immune responses toward self-antigens. Current treatments lack specificity, promoting adverse effects by broadly suppressing the immune system. Therapies that specifically target the immune cells responsible for disease are a compelling strategy to mitigate adverse effects. Multivalent formats that display numerous binding epitopes off a single scaffold may enable selective immunomodulation by eliciting signals through pathways unique to the targeted immune cells. However, the architecture of multivalent immunotherapies can vary widely, and there is limited clinical data with which to evaluate their efficacy. Here, we set forth to review the architectural properties and functional mechanisms afforded by multivalent ligands and evaluate four multivalent scaffolds that address autoimmunity by altering B cell signaling pathways. First, we address both synthetic and natural polymer backbones functionalized with a variety of small molecule, peptide, and protein ligands for probing the effects of valency and costimulation. Then, we review nanoparticles composed entirely from immune signals which have been shown to be efficacious. Lastly, we outline multivalent liposomal nanoparticles capable of displaying high numbers of protein antigens. Taken together, these examples highlight the versatility and desirability of multivalent ligands for immunomodulation and illuminate strengths and weaknesses of multivalent scaffolds for treating autoimmunity.

Disrupting N-Glycosylation Using Type I Mannosidase Inhibitors Alters B-Cell Receptor Signaling

Kifunensine is a known inhibitor of type I α-mannosidase enzymes and has been shown to have therapeutic potential for a variety of diseases and application in the expression of high-mannose N-glycan bearing glycoproteins; however, the compound's hydrophilic nature limits its efficacy. We previously synthesized two hydrophobic acylated derivatives of kifunensine, namely, JDW-II-004 and JDW-II-010, and found that these compounds were over 75-fold more potent than kifunensine. Here we explored the effects of these compounds on different mice and human B cells, and we demonstrate that they affected the cells in a similar fashion to kifunensine, further demonstrating their functional equivalence to kifunensine in assays utilizing primary cells. Specifically, a dose-dependent increase in the formation of high-mannose N-glycans decorated glycoproteins were observed upon treatment with kifunensine, JDW-II-004, and JDW-II-010, but greater potency was observed with the acylated derivatives. Treatment with kifunensine or the acylated derivatives also resulted in impaired B-cell receptor (BCR) signaling of the primary mouse B cells; however, primary human B cells treated with kifunensine or JDW-II-004 did not affect BCR signaling, while a modest increase in BCR signaling was observed upon treatment with JDW-010. Nevertheless, these findings demonstrate that the hydrophobic acylated derivatives of kifunensine can help overcome the mass-transfer limitations of the parent compound, and they may have applications for the treatment of ERAD-related diseases or prove to be more cost-effective alternatives for the generation and production of high-mannose N-glycan bearing glycoproteins.

Lectin Drug Conjugates Targeting High Mannose N-Glycans

Cancer-associated alterations to glycosylation have been shown to aid cancer development and progression. An increased abundance of high mannose N-glycans has been observed in several cancers. Here, we describe the preparation of lectin drug conjugates (LDCs) that permit toxin delivery to cancer cells presenting high mannose N-glycans. Additionally, we demonstrate that cancer cells presenting low levels of high mannose N-glycans can be rendered sensitive to the LDCs by co-treatment with a type I mannosidase inhibitor. Our findings establish that an increased abundance of high mannose N-glycans in the glycocalyx of cancer cells can be leveraged to enable toxin delivery.

Directing CAR NK Cells via the Metabolic Incorporation of CAR Ligands into Malignant Cell Glycans

The abundance of sialic acid-containing glycans in the glycocalyx of malignant cells enables immune evasion. Here, we leverage the biosynthetic pathways that permit pervasive sialylation to incorporate a chimeric antigen receptor (CAR) ligand into malignant cell glycans, and demonstrate that this increases the susceptibility of malignant cells to the cytolytic activity of CAR-expressing natural killer (NK) cells. Specifically, we applied a C-9-functionalized nonnatural sialic acid [i.e., fluorescein sialic acid (FL-SA)] to modify malignant cell glycans. We confirm the metabolic incorporation of FL-SA into plasma membrane-associated glycans. The preparation of anti-fluorescein CAR NK cells permitted studies demonstrating that treating malignant cells with FL-SA increased susceptibility to CAR NK cell-mediated cytolysis. Furthermore, we observed that the specificity of the anti-fluorescein CAR NK cells is enhanced for fluorescein-labeled cells, and an increased release of cytokines from the CAR NK cells upon incubation with FL-SA-treated cells. The results arising from this study demonstrate that CAR ligands can be metabolically incorporated into malignant cells, and we reason that such strategies could be leveraged to tackle the issue of antigen heterogeneity that limits the clinical efficacy of CAR T/NK cell therapies.

The Road to Structurally Defined β-Glucans

β-glucans are polymers of glucose that have been isolated from a variety of organisms. Isolated β-glucans have been used for medical purposes for centuries; however, efforts to define the biological activities of β-glucans experimentally were initiated in the 1940's. The diversity of structure associated with isolated β-glucans has impeded said investigations, and efforts to leverage the biological activity of β-glucans for clinical applications. In recognition of the need for defined β-glucans that retain the biological activity of isolated β-glucans, considerable investment has been made to facilitate the synthesis of structurally defined β-glucans. Here, we review the different approaches that have been applied to prepare β-glucans. In addition, we summarize the approaches that have been utilized to conjugate β-glucans to proteins.

Functionalized High Mannose-Specific Lectins for the Discovery of Type I Mannosidase Inhibitors

An engineered cyanovirin-N homologue that exhibits specificity for high mannose N-glycans has been constructed to aid type I α 1,2-mannosidase inhibitor discovery and development. Engineering the lectins C-terminus permitted facile functionalization with fluorophores via a sortase and click strategy. The resulting lectin constructs exhibit specificity for cells presenting high mannose N-glycans. Importantly, these lectin constructs can also be applied to specifically assess changes in cell surface glycosylation induced by type I mannosidase inhibitors. Testing the utility of these lectin constructs led to the discovery of type I mannosidase inhibitors with nanomolar potency. Cumulatively, these findings reveal the specificity and utility of the functionalized cyanovirin-N homologue constructs, and highlight their potential in analytical contexts that require high mannose-specific lectins.

High-resolution measurements of the DT neutron spectrum using new CD foils in the Magnetic Recoil neutron Spectrometer (MRS) on the National Ignition Facility

The Magnetic Recoil neutron Spectrometer (MRS) on the National Ignition Facility measures the DT neutron spectrum from cryogenically layered inertial confinement fusion implosions. Yield, areal density, apparent ion temperature, and directional fluid flow are inferred from the MRS data. This paper describes recent advances in MRS measurements of the primary peak using new, thinner, reduced-area deuterated plastic (CD) conversion foils. The new foils allow operation of MRS at yields 2 orders of magnitude higher than previously possible, at a resolution down to ∼200 keV FWHM.

Breast cancer detection among Irish BRCA1 & BRCA2 mutation carriers: a population-based study

BACKGROUND

High-risk breast cancer screening for BRCA1/2 mutation carriers with clinical breast exam, mammography and MRI has reported sensitivity of 100 %, but BRCA1/2 mutation carriers still present with interval cancers.

AIMS

We investigated the presentation and screening patterns of an Irish cohort of BRCA1/2 mutation carriers with breast cancer.

MATERIALS AND METHODS

BRCA1/2 mutation carriers with breast cancer were identified in this retrospective cohort study. Records were reviewed for BRCA1/2 mutation status, demographics, screening regimen, screening modality, stage and histology at diagnosis.

RESULTS

Fifty-three cases of breast cancer were diagnosed between 1968 and 2010 among 60 Irish hereditary breast ovarian cancer (HBOC) families. In 50 of 53 women, the diagnosis of breast cancer predated the identification of BRCA1/2 mutations. Breast cancer detection method was identified in 47 % of patients (n = 25): 80 % (n = 20) by clinical breast exam (CBE), 12 % by mammography (n = 3), 8 % by MRI (n = 2). Fourteen women (26 %) developed a second breast cancer. Ten of these patients (71 %) were involved in regular screening; 50 % were detected by screening mammography, 20 % by MRI and 30 % by CBE alone. Six patients (43 %) had a change in morphology from first to second breast cancers. There was no change in hormone receptor status between first and second breast cancers.

CONCLUSION

In this cohort of Irish BRCA1/2 mutation carriers, compliance with screening was inconsistent. There was a 30 % incidence of interval cancers occurring in women in high-risk screening. Preventive surgery may be a more effective risk reduction strategy for certain high-risk women.

Genetic testing and interpretive complexity: a BRCA1 gene mutation example

Diagnosis and interpretation of hereditary breast cancer can be a complex and challenging dilemma. Advances in genetic testing have resulted in guidelines for clinical evaluation and recommendations. Here, we present a case of one family with multiple cases of early-onset breast cancer, some due to a familial BRCA1 mutation but others unrelated to this pathogenic E143X nonsense mutation. In this case report, we highlight the complexities associated with adhering strictly to guidelines and highlight the need for clinical experience in when to deviate from recommended protocols.

Multivariate analysis of MLH1 c.1664T>C (p.Leu555Pro) mismatch repair gene variant demonstrates its pathogenicity

Genetic testing of an Irish kindred identified an exonic nucleotide substitution c.1664T>C (p.Leu555Pro) in the MLH1 mismatch repair (MMR) gene. This previously unreported variant is classified as a "variant of uncertain significance" (VUS). Immunohistochemical (IHC) analysis and microsatellite instability (MSI) studies, genetic testing, a literature and online MMR mutation database review, in silico phenotype prediction tools, and an in vitro MMR activity assay were used to study the clinical significance of this variant. The MLH1 c.1664T>C (p.Leu555Pro) VUS co-segregated with three cases of classic Lynch syndrome-associated malignancies over two generations, with consistent loss of MLH1 and PMS2 protein expression on IHC, and evidence of the MSI-High mutator phenotype. The leucine at position 555 is well conserved across a number of species, and this novel variant has not been reported as a normal polymorphism in the general population. In silico and in vitro analyses suggest that this variant may have a deleterious effect on the MLH1 protein and abrogate MMR activity. Evidence from clinical, histological, immunohistochemical, and molecular genetic data suggests that MLH1 c.1664T>C (p.Leu555Pro) is likely to be the pathogenic cause of Lynch syndrome in this family.

Tobacco use among high school athletes and nonatieletes: results of the 1997 youth risk behavior survey

In the United States today, the use of tobacco has become an entrenched part of teenage culture. The present study used the 1997 Youth Risk Behavior Survey (YRBS), which collected data from a nationally representative sample of 16,262 students in public and private high schools, to compare the tobacco use patterns of athletes and nonathletes. The independent variable, athletic participation, differentiated between moderately involved (1 or 2 teams) and highly involved (3 or more teams) athletes. Frequency of cigarette and cigar smoking and smokeless tobacco use served as the operational measure of tobacco use. Age, race/ethnicity, parental education, and residence were controlled. Logistic regression was used to calculate odds ratios for female and male athletes and nonathletes for each of the tobacco use variables. It was found that both male and female athletes were less likely to have ever smoked regularly, the effect being stronger for more highly involved athletes of both genders. Cigar smoking was unrelated to athlete status. Both female and male athletes were more likely to have used smokeless tobacco, the effect being stronger for more highly involved athletes of both genders. The findings are discussed in terms of access to health information, performance considerations, social status factors, the salience of an athletic identity, and the influence of the athletic subculture on its members.

Health values buffer social-environmental risks for adolescent alcohol misuse

Data from a representative sample of 17- to 20-year-old adolescents were analyzed to investigate whether a health-valuing attitude could buffer the effects of social-environmental risk on adolescent alcohol misuse. A risk index was constructed for adolescents, based on variables such as friends' drinking, parental alcohol abuse, and poor parental monitoring and communication. The expected buffering interaction called for high environmental risk to lead to greater alcohol misuse for adolescents who placed low value on health, but not for those who placed high value on health. The expected interactions were obtained for 2 alcohol-related variables (total consumption and consuming 5 or more drinks at a time).

Informal roles and the stages of interdisciplinary team development

After presenting a theory of team development, we propose that the informal role structure of a team is dependent upon the degree of anomie in the team culture, and we provide measures of anomie and informal roles that can be used in field settings. Then we test hypotheses on a national sample of 111 interdisciplinary health care teams in geriatrics in US Veterans Affairs medical centers. We find evidence that as teams develop from early to later stages, the interpersonal behavior of members becomes less differentiated on three dimensions: prominence, sociability, and task-orientation. In addition, we find that images of each member come into clearer focus, as evidenced by reduced variation in how each member is seen by other team members. Finally, we find that regardless of stage of team development, the more education the team members have, the more prominent and task-oriented they are. In general, physicians score highest in prominence and task-orientation, but relatively low in sociability.

High school athletic participation, sexual behavior and adolescent pregnancy: a regional study

PURPOSE

To determine whether high school athletic participation among adolescents in Western New York was associated with reduced rates of sexual behavior and pregnancy involvement.

METHODS

A secondary analysis of data from the Family and Adolescent Study, a longitudinal study of a random sample of adolescents (ages 13-16 years) from 699 families living in households in Western New York. A general population sample was obtained with characteristics closely matching the census distributions in the area. Interview and survey methods provided data on athletic participation, frequency of sexual relations during the past year, and risk for pregnancy. Bivariate correlations were used to examine relationships among athletic participation, demographic and control variables, and measures of sexual behavior and pregnancy rates. Next, path analyses were done in order to test for hypothesized relationships between athletic participation, sexual behavior, and pregnancy involvement while controlling for age, race, income, family cohesion, and non-athletic forms of extracurricular activity. Variables that were significantly associated with sexual behavior and/or pregnancy involvement were presented for both sexes within the resulting multivariate models.

RESULTS

Lower income and higher rates of sexual activity were associated with higher rates of pregnancy involvement for both sexes. Family cohesion was associated with lower sexual activity rates for both sexes. For girls, athletic participation was directly related to reduced frequency of sexual behavior and, indirectly, to pregnancy risk. Male athletes did not exhibit lower rates of sexual behavior and involvement with pregnancy than male non-athletes. Boys who participated in the arts, however, did report lower rates of sexual behavior and, indirectly, less involvement with pregnancy.

CONCLUSIONS

Female adolescents who participated in sports were less likely than their non-athletic peers to engage in sexual activity and/or report a pregnancy. Among male adolescents, athletic participation was unrelated to sexual behavior and pregnancy involvement. Teen pregnancy prevention efforts for girls should consider utilizing sport as a strategic tool.

Development of an Attitudes Toward Health Care Teams Scale

The authors describe the development and psychometric testing across three study phases of an Attitudes Toward Health Care Teams Scale. The measure contains two subscales: Quality of Care/Process (14 items) and Physician Centrality (6 items). The Quality of Care/Process subscale measures team members' perceptions of the quality of care delivered by health care teams and the quality of teamwork to accomplish this. The Physician Centrality subscale measures team members' attitudes toward physicians' authority in teams and their control over information about patients. Tests of reliability and validity demonstrate that each subscale is a strong measure of its respective underlying concept. The measure has potential for use as a research tool and as a pre- and posttest tool for educational interventions with teams and for evaluating clinically based team training programs for medical and health professions students and residents.

Sports, sexual behavior, contraceptive use, and pregnancy among female and male high school students: testing cultural resource theory

In this paper, we examine the relationships among athletic participation and sexual behavior, contraceptive use, and pregnancy in female and male high school students. Analyses of covariance and multiple analyses of covariance were performed on a nationally representative sample of 8,979 high school students (the 1995 Youth Risk Behavior Survey). After controlling for race and ethnicity, age, and mother’s education, girls who participated in sports had lower rates of sexual experience, fewer sex partners, later age of first intercourse, higher rates of contraceptive use, and lower rates of past pregnancy than girls who did not participate. Male high school athletes reported higher rates of sexual experience and more partners than nonathletes, but—like their female counterparts—were also more likely to have used birth control during their most recent intercourse. Cultural resource theory suggests that athletic participation may reduce girls’ adherence to conventional cultural scripts while providing them with additional social and personal resources on which to draw in the sexual bargaining process. Sports provides boys with similar resources while strengthening their commitment to traditional masculine scripts.

Athletic participation and sexual behavior in adolescents: the different worlds of boys and girls

Using multivariate analysis of covariance to test hypotheses about the effects of sports and sexual behavior on a sample of 611 Western New York adolescents, this study concludes that athletic participation and gender interact to influence adolescent sexual outcomes. Female athletes report significantly lower rates of sexual activity than female nonathletes; male athletes report slightly (though not significantly) higher rates than male nonathletes. The gender-specific effect of sports on sexual behavior remains, net of the impacts of race, age, socioeconomic status, quality of family relations, and participation in other extracurricular activities. This paper introduces cultural resource theory to explain how athletic participation influences both traditional cultural scripts and exchange resources, which, in turn, condition the sexual bargaining process and its outcomes for adolescents.

Parental and peer influences on the onset of heavier drinking among adolescents

OBJECTIVE

Less is known about heavier drinking in adolescents than about alcohol initiation. The present study examined the emergence of regular (weekly) and heavy episodic (five or more drinks at a time) adolescent drinking as a function of social influence (modeling and social control) from parents and peers.

METHOD

A three-wave study was conducted using a representative household sample of families in metropolitan Buffalo, New York (N = 612). Over half (54%) of the adolescent respondents were female. Black families made up 30% of the sample. Interviews were conducted at 1-year intervals. Adolescent drinking was dichotomized at each wave into abstinence/light drinking versus regular drinking. Logistic regression including only adolescents who were abstainers/light drinkers at Wave 1 was performed to assess which Wave- variables could predict regular-drinking onset by Wave 2; a similar analysis examined the onset of heavy episodic drinking by Wave 2. Parallel analyses using Wave-2 variables to predict the onset of the drinking outcomes by Wave 3 were also conducted.

RESULTS

Across the different analyses, the strongest psychosocial predictors of advancement to heavier drinking were friend's drinking and low parental monitoring. Also, white adolescents were at greater risk than their black counterparts.

CONCLUSIONS

A multidimensional approach to prevention that addresses different processes of influence (e.g., modeling and social control) involving both parental and peer domains is likely to be most successful in deterring the onset of heavier drinking in adolescents.

Family cohesion as a buffer against the effects of problem-drinking fathers on psychological distress, deviant behavior, and heavy drinking in adolescents

In this paper we examine the degree to which family cohesion buffers the effects of fathers' problem drinking at Time 1 (T1) on adolescent distress, deviance, and heavy drinking at Time 2 (T2), one year later. Data from a representative sample of 658 families were used to test the hypotheses. Mothers, fathers (if present), and adolescent children were interviewed in the home. Fathers who were present completed self-report scales measuring problem drinking. When fathers were not available, mothers' reports on fathers' drinking were used to measure fathers' problem drinking. Results from regression analysis indicate that after controlling for the effects of race, SES, age, gender, and family structure: (1) the more cohesion in the family and the fever stressful events, the less distress, deviance, and heavy drinking shown by adolescents; (2) the fathers' problem drinking affects adolescent distress and deviance when cohesion is low; but as cohesion increases, the effects of the fathers' drinking are reduced. The findings support the hypothesis that cohesion in families buffers the effects of fathers' problem drinking on adolescents.

Evolution of host cell RNA into efficient template RNA by Q beta replicase: the origin of RNA in untemplated reactions

Q beta replicase can replicate a single molecule of certain species of RNA to 10(14) copies in minutes. This replication ability has been used for in vitro studies of molecular evolution and is currently being utilized as a method of amplifying RNAs that contain probe sequences. It has been observed that Q beta replicase can produce replicatable RNA even in the absence of exogenously added template RNA. The origin of this RNA has been ascribed either to contamination with replicatable RNA or to an ability of Q beta replicase to synthesize RNA de novo from the nucleotides present in the reaction. Technologies that employ Q beta replicase require a thorough understanding of the conditions that lead to this so-called spontaneous RNA production. We have created an expression system and purification method with which we produce gram quantities of highly purified Q beta replicase, and we have identified reaction conditions that prevent the amplification of RNA in assays that do not contain added RNA. However, when these reaction conditions are relaxed, spontaneous RNA replication is seen in up to 100% of the assays. To understand the origin of this RNA, we have cloned several spontaneously produced RNAs. Sequence analysis of one of these RNAs shows that it arose by the evolution of Escherichia coli tRNA into a replicatable template and not by de novo synthesis from nucleoside triphosphates in the reaction.

Identification of human papillomavirus type 16 in primary and recurrent cervical cancer following radiation therapy

Formalin-fixed, paraffin-embedded tissue blocks from 13 women with cervical carcinoma that recurred following radiation therapy were evaluated for the presence of human papillomavirus (HPV) by in situ hybridization using ribonucleic acid 35S-labeled probes for HPV types 6, 11, 16, and 18. Ten of thirteen patients also had pretreatment biopsies from their primary tumors available for analysis. HPV 16 was detected in both primary and recurrent lesions in 4 women. In 1 case, HPV was detected in the primary tumor and not in the recurrence. HPV 16 was also present in three recurrent cancers from which primary lesions were not available for probing. Radiation therapy did not alter the hybridization signal strength or pattern, suggesting that the HPV genome copy number was not significantly affected. The persistence of HPV 16 in recurrent cervical carcinoma is consistent with the theory that HPV plays a role in maintaining the malignant state.

Reasons for non-attendance at a child guidance clinic

A consecutive group of children (n = 19) referred to a child guidance clinic who failed to attend an initial interview were followed-up. These 'non-attenders' did not differ from a matched group of 'attenders' with respect to duration or nature of their problems, waiting period for the appointment, type of referring agencies or socio-demographic variables, but were more likely to be living with their natural parents. Disinclination among the parents was the main reason for absenteeism and could be related to ignorance about the clinic. The problems leading to referral persisted in most cases and had not received further treatment.

Do psychiatric registrars take a proper drinking history?

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Strontium phosphate transfection of human cells in primary culture: stable expression of the simian virus 40 large-T-antigen gene in primary human bronchial epithelial cells

Strontium ion formed DNA-phosphate precipitates analogous to those formed by calcium but lacking the lethal and differentiation-inducing effects of calcium on many epithelial cell types in primary culture. Human primary bronchial epithelial cells were transiently and stably transfected by using strontium phosphate; the frequency of stable transformation with a plasmid carrying the simian virus 40 large-T-antigen gene was greater than 10(-4).

A recombinant murine retrovirus for simian virus 40 large T cDNA transforms mouse fibroblasts to anchorage-independent growth

A recombinant murine retrovirus containing the intact cDNA sequence for the simian virus 40 (SV40) large T antigen (T) was constructed by using the pZIPNeo SV(X)1 vector. Psi 2 packaging cells were then transfected, and G418-resistant clones were used to generate helper-free viral stocks. NIH 3T3 mouse fibroblasts infected by the recombinant T cDNA retrovirus were selected fro G418 resistance. Such cultures synthesized authentic SV40 T and were transformed to anchorage-independent growth at high efficiency. Therefore, this vector has allowed the study of the transformation properties of T under conditions of neutral drug selection and in the absence of SV40 small t antigen.

Statistical analysis of structure-activity relationships

The relationship between organic structure and biological activity (toxicity) is examined by statistically comparing concentration-response regression lines among structurally related compounds. Response data from acute toxicity tests are initially transformed to the logistic function while concentration data are transformed to the logarithm base 10 before being fit to a linear model using a weighted least squares analysis. A sequential approach is presented that uses statistical models for testing differences among related compounds. The approach first tests for the overall equality of regression lines (slopes and intercepts). If the regression lines are found to be different, another set of tests are conducted to determine if the slopes of the lines are equal (i.e. parallel). If the slopes are equal, multiple comparisons are made using Scheffé's procedure for determining which compounds differ in their intercepts. Relative toxicities are then estimated for various concentrations of particular compounds.

Polypeptide synthesis and phosphorylation in Epstein-Barr virus-infected cells

Epstein-Barr virus superinfection of the human lymphoblastoid cell line Raji, a Burkitt lymphoma-derived line that contains Epstein-Barr virus genomes in an episomal form, results in the sequential synthesis of 29 detectable proteins, which range in molecular weight from approximately 155,000 to 21,000, and in the shutoff of the bulk of host protein synthesis within 6 to 9 h after infection. There are three classes of virus-induced proteins; these are an early class, consisting of eight proteins synthesized by 6 h postinfection, an intermediate class, containing two proteins synthesized 9 h postinfection, and a late class, consisting of five proteins synthesized 12 h postinfection. In addition, there is a fourth class of polypeptides, called persistent, that are found both before and after superinfection. The rates of synthesis of the proteins fall into three patterns; these are pattern A, in which the rate of synthesis decreases, pattern B, in which the rate of synthesis remains steady, and pattern C, in which the rate of synthesis increases after the initial appearance of the polypeptide. Both 9-(2-hydroxy-ethoxymethyl)guanine (acyclovir) and phosphonoacetic acid inhibit the appearance of one intermediate protein and at least three late proteins. Seven polypeptides are phosphorylated at different times after infection.

T antigen of BK papovavirus in infected and transformed cells

BK virus T antigen from BKV-transformed rat and hamster cells and from productively infected monkey cells has been examined by immunoprecipitation followed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Forms of the antigen that migrate as proteins of 86,000 and 92,000 daltons have been identified. Both forms can be labeled by 32P.

Effects of Sevin on the reproductive biology of the Coturnix

Adult Coturnix quail (Coturnix coturnix japonica) were subjected to three levels of carbaryl pesticide treatment (Sevin-20 p.p.m., 40 p.p.m., and 400 p.p.m) and monitored to observe any modifications in either their reproductive biology or behavior. There was an increase in the amount of pesticide excreted with increasing treatment levels during the first 48 hours following intubation, after which pesticide levels in the fecal material for all groups approached zero. Addditionally, significant amounts of the pesticide were detected in the egg yolks after pesticide ingestion (treatment levels, 20, 40, and 400 p.p.m. resulted in pesticide residues of 1.58, 2.03, and 3.15 p.p.m., respectively). Egg production was significantly reduced (p less than or equal to 0.05), although egg viability was not affected by the pesticide stress. Agonistic behavior decreased in males while it increased in the females following pesticide ingestion.

Identity and crisis in middle aged men

The authors selectively review disparate literature bearing on the issue of the male mid-life transition. There is considerable evidence that the entrance into middle age is associated with stress and often maladaptive patterns of reaction. There is little available information, however, on the specific nature of the stressors, their differential impact, or the factors associated with the individual's attempted style of adaptation to them. Through the process of exploring relevant findings from sociology, social and clinical psychology, and popular fiction we attempt to specify a working model of the experience of entering middle age. The authors see this model as being of heuristic value in that it specifies a number of dimensions to be operationalized which may, together, provide a more holistic view of the changes in the self-system undergone by the middle aged male.

Rapid determination of the amount of cetylpyridinium chloride bound by bacteria

A modification of the Colowick and Womack procedure for measuring ligand binding by macromolecules is described for drug binding by bacteria. This technique is based on the determination of drug concentration in the dialysate from a bacteria-drug mixture at equilibrium. The dialysis cell of the original procedure was replaced by a Minibeaker (Bio-Rad), which has a larger membrane surface area, and the dialysate was continuously monitored with a spectrophotometer equipped with a flow cell. With this system, only 3 min was required to determine the amount of cetylpyridinium chloride bound by Escherichia coli K-12 strain P678. Possible applications of the technique are discussed.