Medication Abortion and Abortion Pill Reversal: An Exploratory Analysis on the Influence of Others in Women's Decision-Making

Introduction As medication abortion accounts for a growing share of abortions in the United States, an increasing number of women are seeking abortion pill reversal (APR). These decisions are typically not made in isolation. However, little research exists on women's APR decision-making and the role played by people close to them. Methods We surveyed women who contacted a national hotline for information on APR and who completed a two-week treatment protocol with progesterone (n = 67). We analyzed women's open-ended answers using thematic analysis to identify memorable messages about medication abortion and APR. Participants' communication with other people in their lives was assessed using the Isolation subscale of the Individual Level Abortion Stigma (ILAS) scale, and decision-making difficulty was assessed using a Likert scale. Results Thirty-six respondents met the eligibility criteria and filled out the ILAS and decision-difficulty scales. Women tended to talk with family and friends about their medication abortion decisions, while they typically sought information online when deciding about APR. Women reported greater stigma in their disclosures about their abortions than in their disclosures about APR (p = 0.006). Conclusion Memorable messages influence women's decisions to pursue medication abortion and APR.

The Effects of Abortion Decision Rightness and Decision Type on Women's Satisfaction and Mental Health

Background A case series report based on the Turnaway Study has previously concluded that 99% of women with a history of abortion will continue to affirm satisfaction with their decisions to abort. Those findings have been called into question due to a low participation rate (31%) and reliance on a single yes/no assessment of decision satisfaction. Aim To utilize more sensitive scales in assessing decision satisfaction and the associated mental health outcomes women attribute to their abortions. Method  A retrospective survey was completed by 1,000 females, aged 41-45, living in the United States. The survey instrument included 11 visual analog scales for respondents to rate their personal preferences and outcomes they attributed to their abortion decisions. A categorical question allowed women to identify if their abortions were wanted and consistent with their own values and preferences, inconsistent with their values and preferences, unwanted, or coerced. Linear regression models were tested to identify which of three decision scales best predicted positive or negative emotions, effects on mental health, emotional attachment, personal preferences, moral conflict, and other factors relevant to an assessment of satisfaction with a decision to abort. Results Of 226 women reporting a history of abortion, 33% identified it as wanted, 43% as accepted but inconsistent with their values and preferences, and 24% as unwanted or coerced. Only wanted abortions were associated with positive emotions or mental health gains. All other groups attributed more negative emotions and mental health outcomes to their abortions. Sixty percent reported they would have preferred to give birth if they had received more support from others or had more financial security. Conclusions Perceived pressure to abort is strongly associated with women attributing more negative mental health outcomes to their abortions. The one-third of women for whom abortion is wanted and consistent with their values and preferences are most likely over-represented in studies initiated at abortion clinics. More research is needed to understand better the experience of the two-thirds of women for whom abortion is unwanted, coerced, or otherwise inconsistent with their own values and preferences.

#AbortionChangesYou: A Case Study to Understand the Communicative Tensions in Women's Medication Abortion Narratives

One out of four women in the United States will have an abortion by age 45. While abortion rates are steadily declining in the United States, the rate of medication abortions continues to increase, with 39% of all abortions being medication abortions. Our study is one of the first to analyze women's narratives after having had a medication abortion. Using relational dialectics theory, we conducted a case study of the nonpartisan website, Abortion Changes You. Our contrapuntal analysis rendered four sites of dialectical tension found across women's blog posts: only choice vs. other alternatives, unprepared vs. knowledgeable, relief vs. regret, and silence vs. openness. Each site of struggle characterized a different noteworthy moment within a woman's medication abortion experience: the decision, the medication abortion process, identity after abortion, and managing the stigmatizing silence before and after the abortion. We discuss theoretical and practical implications about how the larger politicized discourses prevalent within the abortion debate impact the liminality of women who are contemplating a medication abortion and affect their own narrative construction about the medication abortion experience.

Mothers' Support Preferences With Their Chronically Ill Child's Health Care Team

Children living with medical complexities are a growing population in the United States. Supportive pediatric health care team members are arguably the single most important factor in helping mothers manage their child's multifaceted condition. To better understand what constitutes helpful support from health care team members, we interviewed 17 mothers affiliated with a pediatric palliative care program at a large Midwestern U.S. hospital. Using Charmaz's approach to grounded theory analysis, we found that mothers desired a collaborative partnership with their child's health care team. However, the development of this partnership was contingent upon team members' effective use of informational, emotional, and network support. We identified two specific strategies that qualified each of these three different types of helpful supportive communication. These strategies may be implemented into training and educational programs for health care professionals to improve their communication skills.

When Facing Hopeful and Hopeless Experiences: Using Snyder's Hope Theory to Understand Parents' Caregiving Experiences for Their Medically Complex Child

INTRODUCTION

An emerging subpopulation within pediatric chronic illness is children living with complex chronic conditions. Managing a child's complex chronic conditions can be emotionally taxing for parents. Many parents regard hope as a "life-sustaining and essential" process for them.

METHOD

We used the central concepts within Snyder's hope theory to guide our directed content analysis of parents' interviews about their hopeful and hopeless experiences. Our sample consisted of primarily Christian married mothers.

RESULTS

We found themes within each concept of Snyder's hope theory that clarifies the social and communicative processes that facilitate more hopeful thinking for parents.

DISCUSSION

Understanding how individuals communicate or enact hopeful thinking is an important contributor to performing hope in social settings like hospitals and nonprofit organizations (Ronald McDonald House) that support parents with medically complex children. Our findings indicate that messages should help parents identify care solutions, offer words of encouragement, and help parents create life goals that maintain a child's quality of life.

"You Are Not Alone": Advice Giving for Parents of Children Living with Complex Chronic Conditions

Parental advice giving serves as an important form of informational support for parents of children living with complex chronic conditions (CCCs). These messages can provide backchannel insights into social challenges, best practices, and may offer different forms of experiential wisdom garnered from their own parental caregiving experiences. Contributing to the naturalistic, health-context investigations of advice messages, we interviewed 35 parents who discussed their experiences with parenting their medically complex child. Part of the broader interview protocol asked parents about advice they would offer to other parents like them. We conducted a thematic analysis of parents' responses to these questions to understand advice content, form of advice giving messages, challenges experienced by parents, and suggested best practices for managing a child's CCC. We present our findings and discuss implications on educating health care professionals about how to cultivate advice networks and the need for more parent peer mentoring programs.

"I Will Communicate With You, But Let Me Be In Control": Understanding How Parents Manage Private Information About Their Chronically Ill Children

Parents have a significant role in the management of a child's chronic condition. Parents are often the only consistent individuals managing a child's health across his or her childhood and adolescence (e.g., present for all appointments and medical procedures). Many of the responsibilities required of parents involve communication work, where parents must strategically and actively design messages as they interact with medical professionals, other family, and friends. Using communication privacy management theory, we analyzed interviews conducted with 35 parents to understand the motivations and strategies involved in their regulation of information about their child's chronic condition. These findings have important practical implications because parental involvement in a chronically ill child's care has direct effects on familial adaptation and adjustment.

"You Know the Medicine, I Know My Kid": How Parents Advocate for Their Children Living With Complex Chronic Conditions

Caring for a child with a chronic condition has received considerable attention in the pediatric health literature. Today, approximately 1 out of 5 North American children are diagnosed with a chronic condition that requires parents to become caregivers and advocates. Although advocacy is regarded as a significant aspect to parental caregiving, more research is needed to better define this oversimplified and misrepresented concept in clinical practice and research. Subsequently, we interviewed 35 parents of children diagnosed with complex chronic conditions. Within our analysis, we identified three themes that elaborate upon how parental advocacy is socially constructed through communication behaviors and partnerships with other people (e.g., medical professionals, family, school educators). We also discuss the emotional side of advocacy, and proffer suggestions to practitioners who work with parents to form collaborative care teams.

An examination of actor-partner social support effects on HIV-related problems and interpersonal outcomes among a sample of HIV-positive African American dyads

OBJECTIVES

Social support is an important resource that has been associated with better mental and physical health outcomes among HIV-positive people. However, researchers have not adequately explored how social support functions among HIV-positive African Americans. The purpose of the current study was to understand whether HIV-related support resources are associated with relational functioning and HIV-related problems among a sample of HIV-infected African American dyads.

METHOD

Exactly 34 HIV-infected (i.e., seroconcordant) dyads compromised of HIV-positive African American adults and their HIV-positive adult "informal supporters" from 3 Midwestern urban cities completed psychosocial questionnaires and a communication task. Using the actor-partner interdependence model, we analyzed dyadic data to determine whether there were actor and/or partner effects within dyadic relationships on measures of conflict and HIV-related problems, communication about these problems, and health symptoms.

RESULTS

We found significant negative relationships between perceived support and HIV-related problems and perceptions of problem inequity within dyads and a positive relationship between perceived support and communication about these problems within dyads. Contrary to our expectations, we found no relationship between social support and HIV symptoms, relational conflict, or perceptions about dyadic partners' HIV-related problems.

CONCLUSIONS

Although our study precludes drawing causal conclusions, we found evidence of a relationship between the personal experience of HIV-related problems, communication about these problems, and perceptions of social support among a small sample of HIV-infected African American dyads. These findings suggest the need to consider how support-related communication within HIV-infected dyads might influence and be influenced by problem perceptions.

Spirituality, Religion, and Health: The Role of Communication, Appraisals, and Coping for Individuals Living with Chronic Illness

Currently, 10% of Americans are living with a chronic illness. One coping mechanism for individuals living with chronic illness is religion and/or spiritual (R/S). To better explicate the relationship among R/S and psychological well-being, we conceptualize R/S as an interpersonal process involving conversations that may facilitate positive reappraisals. We use a mixed-method approach from data collected from 106 participants, involving a content analysis of R/S conversations and test Burleson and Goldsmith's (Handbook of communication and emotion: research, theory, applications, and contexts, Academic Press, San Diego, pp 245-280, 1998) appraisal-based comforting model. Partial support for the model was found. In addition, the majority of R/S conversations were considered positive, helpful, and supportive. Theoretical and practical implications are discussed.

Managing End-of-Life Uncertainty: Applying Problematic Integration Theory to Spousal Communication About Death and Dying

A significant number of Americans die in ways that do not reflect their preferences for end-of-life (EOL) care. For married individuals, the spouse often has the legal authority to make decisions at EOL. Many factors, most notably open preemptive communication about care preferences and dying wishes, determine whether such communication is viable and a partner's wishes are respected. We used a mixed method approach, involving a content analysis of spouses' reasons for seeking and avoiding conversations regarding their partners' EOL care preferences, and examined whether certain demographic factors (eg, income, gender, age) more likely contributed to the initiation of EOL conversations. We situate our findings within the broader cultural discourse about death and dying and highlight the influence of uncertainty in spousal EOL communication.

Talking about end-of-life preferences in marriage: applying the theory of motivated information management

The theory of motivated information management (TMIM) provides one framework to examine information-seeking behaviors, especially in conversations involving sensitive or difficult information such as preferences for end-of-life (EOL) care. The spouse plays a significant role in decision making surrounding EOL care. Consequently, individuals need information about spouses' EOL preferences in order to ensure carrying out those desires. Our findings support the value of TMIM as a framework to understand factors that influence couples' EOL care information-seeking behaviors. In support of the theory, we provide factors that influence the initiation or avoidance of EOL conversations between spouses.

Lens cytoskeleton and after-cataract

Lens epithelial and other ocular cells contain complex arrays of actin filaments which might be expected to allow them to migrate following injury: specifically into the capsular sac in cases of extracapsular cataract extraction or traumatic cataract. To test the possibility, a culture system was developed using a melanotic strain of mice, in which migrating cells are often 'marked' by melanosomes. Injured lenses were cultured on permeable membranes in contact with nutrient medium, and surrounded by iridial tract fragments. After study by light and electron microscopy, it was established that both pigmented and unpigmented cells migrated from the surrounding explants, apparently along the substrate meniscus, to the outside of the lens capsule and then through the wound to the capsule interior. This study suggests a source of cells in development of after-cataract syndrome.

Dietary calcium and vitamin D intake in elderly women: effect on serum parathyroid hormone and vitamin D metabolites

In this study, the effect of dietary calcium and vitamin D on serum parathyroid hormone and vitamin D metabolites was measured in 376 free-living women aged 65-77 y. Mean calcium intake in both groups was close to the recommended dietary allowance of 800 mg/d. Mean vitamin D intake in the 245 women not taking vitamin D supplements was 3.53 microg/d (141 IU/d), which is below the recommended dietary allowance of 5 microg/d (200 IU/d). To test the hypothesis that vitamin D is more important than calcium in reducing serum parathyroid hormone, the source of dietary calcium intake was subdivided into milk, which is fortified with vitamin D, and nonmilk sources. The serum parathyroid hormone concentration was inversely correlated with calcium intake derived from milk (r = -0.20, P < 0.01) but not from nonmilk sources (r = -0.06). Furthermore, serum calcidiol correlated with milk calcium intake (r = 0.35, P < 0.001) but not with nonmilk calcium intake (r = 0.10). Multivariate analysis showed a significant effect of season on serum calcidiol but not on serum parathyroid hormone. Serum parathyroid hormone was inversely correlated with serum calcidiol (r = -0.33, P < 0.001) and the regression predicted that mean serum parathyroid hormone would be reduced in the elderly to concentrations considered normal in the young when serum calcidiol is 122 nmol/L (49 ng/mL); this would require a much higher recommended dietary allowance for vitamin D than 5 microg/d (200 IU/d).

Comparative response to UV irradiation of cytoskeletal elements in rabbit and skate lens epithelial cells

PURPOSE

This work reports a differential effect of ultraviolet A (UVA) irradiation on the three major cytoskeletal structures, actin and vimentin filaments and microtubules of lens cells in primary culture. The effect on cells from lens of the skate (a bottom-dwelling marine elasmobranch) was compared with that on rabbit lens, in order to assess UVA sensitivity as a function of exposure to these wavelengths in the native habitat.

METHODS

Exposure intervals of irradiation time up to 6 hours were selected, at fluences from 13.5 to 54.4 J/cm2 and at 365 +/- 45 nm wavelength, to represent mild to moderate physiological levels. Cultures were fixed and processed with anti-alpha-tubulin-FITC and rhodamine phalloidin, or with anti-vimentin FITC and rhodamine phalloidin conjugates.

RESULTS

With epifluorescence microscopy, it was found that microtubules were most sensitive to UVA irradiation (in depolymerizing), followed by actin, with vimentin hardly at all affected. Irradiation for 6 hours followed by incubation for 3 days in fresh medium showed no recovery of actin but good recovery of microtubule organizing centers, followed by mitosis in many (rabbit) cells. Skate cells were more sensitive and showed no recovery.

CONCLUSIONS

In view of the role of cytoskeletal elements in intracellular structure, cell division and transport, their disruption supports the hypothesis that UVA may damage lens epithelial cells in vivo so as to contribute to cataract formation. In addition, the data suggest that the lenses of animals exposed to sunlight require effective cytoskeletal repair mechanisms to avoid loss of function.

Serum vitamin D metabolites and calcium absorption in normal young and elderly free-living women and in women living in nursing homes

Vitamin D deficiency, which causes osteomalacia, may also be important in the pathogenesis of age-related osteoporosis. We studied serum vitamin D metabolites in 52 young women (mean age: 30 +/- 3 y; range: 25-35 y), 64 elderly free-living women (mean age: 71 +/- 4 y; range: 65-82 y), and 60 elderly women living in nursing homes (mean age: 84 +/- 9 y; range: 61-102 y). Mean serum 25-hydroxyvitamin D (calcidiol) was 10.8 +/- 4.4 nmol/L (27 +/- 11 ng/mL) in women living in nursing homes and was similar to that of free-living young (11.3 +/- 4.2 nmol/L, or 28 +/- 10 ng/mL) and elderly (11.5 +/- 3.2 nmol/L, or 29 +/- 8 ng/mL) women. Vitamin D deficiency (defined as serum calcidiol < 4.8 nmol/L, or 12 ng/mL) occurred in 8% of women living in nursing homes, in 6% of the young women, and in 1.6% of the free-living elderly women. Serum calcidiol was significantly correlated with vitamin D intake (r = 0.25, P < 0.05) and inversely correlated with serum intact parathyroid hormone (iPTH) (r = -0.16, P < 0.03). Serum iPTH increased with age and secondary hyperparathyroidism was observed in 17% of the women living in nursing homes. Calcium absorption declined with age, but calcium absorption and serum 1 alpha,25-dihydroxyvitamin D (calcitriol) were significantly lower in women living in nursing homes, which probably contributed to the secondary hyperparathyroidism. In conclusion, normal serum calcidiol may avoid the problem of osteomalacia, but it does not correct malabsorption of calcium. Although calcitriol corrects the malabsorption of calcium, it remains to be seen whether higher amounts of vitamin D can normalize the calcium malabsorption of aging.

Agonist-induced rise in intracellular calcium of lens epithelial cells: effects on the actin cytoskeleton

Primary cultures of rabbit and skate lens epithelia were used to investigate the effect of calcium release from intracellular stores upon the actin cytoskeleton. Primary cultures were loaded with fura-2 AM and intracellular calcium, i.e. (Ca2+)i, quantitated using a Hamamatsu Photonics digital imaging system. Agonists used were bombesin, inositol-1,4,5-trisphosphate (IP3), thapsigargin (Tg), neuropeptide Y (NPY) and calcium chloride. Recordings were typically made on seven cells in each case. We found that IP3 caused a 6-8-fold immediate release of (Ca2+)i in rabbit cells, but skate cells showed no response unless permeabilized with saponin, whereupon an increase of about 50% occurred. Tg induced release from internal stores in rabbit cells, but had no effect on skate cells. Bombesin caused a large increase in (Ca2+)i release in both, while NPY had no effect in either. Skate cells incubated in calcium-free EGTA-Ringer's solution responded rapidly to addition of 5 mM CaCl2, whereas only three of 35 rabbit cells responded, and in gradual fashion. After calcium imaging, the cells were fixed and stained with rhodamine phalloidin or with an antibody against IP3 receptor (IP3R) conjugated to FITC. Fluorescence microscopy revealed that the actin cytoskeleton had reorganized from the normal stress fiber pattern into polygonal networks. Tg caused the same structures to form in rabbit cells, but bombesin had no effect. IP3 receptor was located intracellularly, presumably on endoplasmic reticulum, and was not associated with plasma membranes. The rapid response of rabbit cells may have been caused by the DMSO in which fura-2 was dissolved. We have found an interesting difference in agonist-induced calcium release between rabbit and skate cells. The latter may utilize either a Ca-Na exchanger or capacitative calcium entry, which could reflect a difference in lens accommodative mechanisms. This seems relevant in view of the fact that the rabbit lens accommodates through change in shape, whereas the skate lens does so through translation of position.

Growth potential of the cells of permanent lines (HeLa, BHK/21, NRK)

A variety of culture parameters was tested to determine optimum growth conditions for the permanent cell lines HeLa, BHK/21 and NRK. Although the lines grew as well at clonal density as in mass culture, clonal analysis of cells transferred on coverslip fragments showed that only 71%-85% were able to produce permanent sublines. Kinetic analysis of the growth of individual clones showed that they varied widely in growth rate, despite continuous low density propagation designed to select out slowly growing cells. In addition, cytopathology was frequently evident in all lines studied, either when cultured at clonal density or under "ideal" conditions at moderate density. The results indicate that defective cells are continuously produced and that they exist in stable proportion in equilibrium cultures. These findings are at variance with claims that some permanent lines (i.e., HeLa) plate with 100% efficiency. Results are discussed in terms of the methodology used to determine plating efficiency, and also in terms of stochastic theories of cell kinetics, which predict the occurrence of cell death in permanent lines and explain the interconversion of permanent and limited cell lines observed in other systems.

Kinetics of chick embryo cell types in culture

The growth kinetics and population doubling limits of chick embryonic fibroblasts, chondroblasts, and retinal pigment cells were compared. Chondroblasts were found to have a cumulative population doubling level (37 +/- 3 PDL) similar (p = 0.05) to that of control fibroblasts (42 +/- 2 PDL), in individual and pooled clones. While both cell types have similar doubling potential, the proportion of tritium-labeled nuclei decreases, and differs significantly as doubling level increases. This age-associated decline is due to an extension in the population doubling time. Direct cell-cycle analysis shows this increase to occur in the G1 phase. Furthermore, cartilage colonies maintain their phenotypic expression (metachromasia) throughout their lifespan under conditions of subcloning at sparse density. When fibroblasts derived from 15 day chick embryos are compared with fibroblasts from 10 day embryos (41 +/- 2 PDL) there is no significant difference (p = 0.05) in cumulative PDL or percent labeled nuclei, indicating that fibroblasts of different embryonic age have similar potential. The addition of hydrocortisone and insulin to the medium significantly shortens (25 +/- 2 PDL) the lifespan of 10 day chick fibroblasts. Kinetics of retinal pigment cells show a population doubling potential (29 +/- 1 PDL) different from fibroblasts and chondroblasts, suggesting that different cell types may not have similar limits on doubling potential when first determined in embryogenesis. Hydrocortisone and insulin have no effect on the growth kinetics or lifespan of retinal pigment cells in culture.

Cell population kinetics of the mouse lens epithelium

The dividing lens epithelium of 8-week-old CF1 mice consists of a monocellular layer of about 31,000 cells and does not include the postmitotic cells of the meridional rows and another postmitotic zone of seven cell positions' width immediately anterior to the rows. The latter two populations contain approximately 3,600 and 9,000 cells, respectively, for a total of 44,000 cells in the entire lens epithelium. Autoradiographic analysis based upon mitotic index and cell cycle times indicates that the epithelium produces 207 new lens fibers a day. Throughout the 20-day period of study, labeled cells appeared almost entirely as pairs following a single dose of 3H-thymidine and clusters of labeled nuclei were not seen. Moreover, the number of labeled cells dropped only slowly with time, as did the grain counts. These observations indicate that logarithmic division "cascade" does not occur in the lens. The dividing cell population consists largely of a slowly cycling stem cell group, dividing once about every 17-20 days, and consisting of some 5,000 cells. A subpopulation may exist which undergoes two rapid consecutive divisions before becoming postmitotic, but this is too small to make a significant contribution to lens fiber production. Four days are required to transit the postmitotic zone, and an additional 43 or so are needed to transit the meridional rows and differentiate into anucleate lens fibers. Data from other laboratories indicate that the entire process, from mitosis to final differentiation, requires about 4 months. Hence, most of this time is spent in migration of nondividing cells.

Colony formation by simian virus 40-transformed human parapharyngeal cells cultured in semisolid agar

A simian virus 40 (SV40)-transformed line of human parapharyngeal cells (SV-TGo) was cultured in semisolid agar to determine its ability to grow in the absence of an anchoring substratum and to evaluate any phenotypic changes that might have resulted during the isolation of sublines specifically selected for anchorage independence. After 2--3 weeks and 14--15 population doublings in culture, SV-TGo plated with over 1,000% higher efficiency than negative controls (F2408 cells). Sublines, 0.3--2.0 mm in diameter, were isolated and transferred to Leighton tubes in which they underwent an additional 0--7 divisions before senescence after 39--44 total population doublings. Subline phenotype was identical to the original parental phenotype, including epithelioid morphology, organized pattern of growth, extreme sensitivity to density-dependent inhibition of growth, and continuous production of infectious SV40 as detected by the combined tests of cocultivation and direct isolation. Limited division potential was within the range observed for the parental line. The ability to grow in agar without identifiable phenotypic changes was therefore confirmed for this line of SV40-transformed human epithelioid cells.

A virus-producing cell line developed by transformation of human parapharyngeal cells with SV40

Normal cultures of epithelial appearance were initiated by trypsinization of a surgically resected, histologically normal branchial cyst. Cellular morphology was consistent with derivation from the stratified squamous epithelium of the cyst or from vascular endothelium, although electron micrographs of the cultured cells failed to show any junctional complexes. Infection with SV40 produced transformants which were also epithelioid in appearance. These grew vigorously for 22 to 50 population doublings (about 23 to 32 subcultures, depending upon regimen) and then became quiescent. During this evolution, virus was detectable at all stages by both direct isolation (cell extracts) and cocultivation with permissive cells. In two sublines in which selection for rapidly growing cell types occureed, virus was detected only by cocultivation. The work confirms that of others in the finding that normal human epithelial cells are susceptible to transformation by oncogenic viruses, but are apparently less responsive than are fibroblasts to such transforming agents. It also suggests that subcultivation techniques that maintain the populations of transformed cells at low density tend to select against cell strains that are continous producers of infectious virus.

The length of secondary chromosomal constrictions in normal individuals and in a nucleolar mutant of Xenopus laevis

Secondary chromosomal constrictions are thought to be the loci of the genome which code for ribosomal RNA synthesis. Their metaphase length could depend on nucleolar size or level of functional activity in interphase or on gene content. Wild-type frogs and a frog heterozygous for the Oxford nucleolar mutation were studied to determine which possibility is more probable. The mutant was studied because its single nucleolus is larger than wild-type nucleoli, it has only one constriction, half as many ribosomal genes, but produces the same amount of ribosomal RNA. The results indicate (1) that constriction length depends on the amount of genome (whereas others have shown nucleolar size to be related to level of activity) and (2) that the deletion is limited to the constricted segment, supporting the view that the constriction is the nucleolar organizer. Also, metaphase constrictions are longer than expected from their DNA content.

High Incidences of Transmissible Kidney Tumors in Uminoculated Frogs Maintained in a Laboratory

Various workers have shown that the Lucké carcinoma, a transmissible kidney tumor of the leopard frog, occurs spontaneously at low incidence (6.7 percent maximum). However, we have consistently observed much higher incidences (50 percent maximum), a finding of probable significance in the epidemiology and natural transmission of the tumor. Age, metabolic level, and cross infection are being investigated as possible factors in determining the tumor incidence.