A review of the mesotheliogenic potency of cleavage fragments found in talc

It has long been recognized that amphibole minerals, such as cleavage fragments of tremolite and anthophyllite, may exist in some talc deposits. We reviewed the current state of the science regarding the factors influencing mesotheliogenic potency of cleavage fragments, with emphasis on those that may co-occur in talc deposits, including dimensional and structural characteristics, animal toxicology, and the most well-studied cohort exposed to talc-associated cleavage fragments. Based on our review, multiple lines of scientific evidence demonstrate that inhaled cleavage fragments associated with talc do not pose a mesothelioma hazard.

Assessment of worst-case potential airborne asbestos exposure associated with the use of cosmetic talc: application of an exponential decay model

Talc is used in cosmetic products to confer desirable properties, such as moisture absorption and smooth texture, to the finished products. Concerns have been raised about the potential presence of asbestos in products containing cosmetic talc. Reconstruction of potential asbestos exposure from the use of cosmetic talc products (assuming a trace level of asbestos) requires consideration of consumer use patterns. Although application generally only lasts seconds, exposure theoretically may continue if the consumer remains in the immediate vicinity. Most published exposure measurements have not adequately characterized the potential for continued exposure. In this analysis, estimates and measurements of airborne asbestos fiber concentrations associated with cosmetic talc use from 10 published studies were used as inputs to an exponential decay model to estimate "worst-case" exposure during and following application. The resulting geometric mean 30-min time-weighted average (TWA) concentrations were 0.006 f/cc for both puff and shaker application, for diapering, 0.0001 f/cc (adult applying baby powder) and 0.0002 f/cc (infant), and for makeup application, 0.0005 f/cc. Application of an exponential decay model to measured or estimated asbestos concentrations associated with the use of cosmetic talc products yields a conservative means to comprehensively reconstruct such exposures. Moreover, our results support that, if a cosmetic talc powder product contained a trace level of asbestos fibers, the "worst-case" airborne asbestos exposure associated with its application is low.

Parental diabetes distress is a stronger predictor of child HbA1c than diabetes device use in school-age children with type 1 diabetes

INTRODUCTION

Diabetes distress (DD) describes the unrelenting emotional and behavioral challenges of living with, and caring for someone living with, type 1 diabetes (T1D). We investigated associations between parent-reported and child-reported DD, T1D device use, and child glycated hemoglobin (HbA1c) in 157 families of school-age children.

RESEARCH DESIGN AND METHODS

Parents completed the Parent Problem Areas in Diabetes-Child (PPAID-C) and children completed the Problem Areas in Diabetes-Child (PAID-C) to assess for DD levels. Parents also completed a demographic form where they reported current insulin pump or continuous glucose monitor (CGM) use (ie, user/non-user). We measured child HbA1c using a valid home kit and central laboratory. We used correlations and linear regression for our analyses.

RESULTS

Children were 49% boys and 77.1% non-Hispanic white (child age (mean±SD)=10.2±1.5 years, T1D duration=3.8±2.4 years, HbA1c=7.96±1.62%). Most parents self-identified as mothers (89%) and as married (78%). Parents' mean PPAID-C score was 51.83±16.79 (range: 16-96) and children's mean PAID-C score was 31.59±12.39 (range: 11-66). Higher child HbA1c correlated with non-pump users (r=-0.16, p<0.05), higher PPAID-C scores (r=0.36, p<0.001) and higher PAID-C scores (r=0.24, p<0.001), but there was no association between child HbA1c and CGM use. A regression model predicting child HbA1c based on demographic variables, pump use, and parent-reported and child-reported DD suggested parents' PPAID-C score was the strongest predictor of child HbA1c.

CONCLUSIONS

Our analyses suggest parent DD is a strong predictor of child HbA1c and is another modifiable treatment target for lowering child HbA1c.

Psychosocial Staffing and Implementation of the International Society for Pediatric and Adolescent Diabetes Psychological Care Guidelines in U.S. Pediatric Diabetes Clinics

Background

Few studies have examined the implementation of the International Society for Pediatric and Adolescent Diabetes (ISPAD) Clinical Practice Consensus Guidelines for the Psychological Care of Children and Adolescents with Type 1 Diabetes.

Objective

To collect benchmark data on psychosocial staffing and implementation of the ISPAD guidelines across U.S. pediatric diabetes clinics.

Methods

Medical (n = 95; 77 endocrinologists and 18 advance practice providers) and psychosocial (n = 86; 43 social workers and 43 psychologists) providers from 98 of 115 contacted clinics completed an online survey (85% response rate). Providers reported the number of psychosocial staff and rated the adequacy of psychosocial staffing, quality of psychosocial care, and adherence to the ISPAD guidelines in their clinics. χ2 Tests and ANOVA were used to examine differences across clinic size and across medical and psychosocial providers.

Results

Clinics averaged a total of ∼4 hours per week of psychosocial provider time per 100 patients with type 1 diabetes. Only 27% of providers agreed that psychosocial staffing was adequate, and 35% described their psychosocial care as comprehensive. Implementation of the ISPAD guidelines varied across clinics, with minimal differences across clinic size. Medical providers reported that evidence-based psychological assessment and interventions were delivered consistently by <55% of clinics. Psychosocial, compared with medical, providers were more likely to report frequent implementation of psychosocial assessment and intervention guidelines.

Conclusion

Psychological care in U.S. pediatric type 1 diabetes clinics does not consistently meet the ISPAD guidelines, and many clinics lack adequate psychosocial staff. These benchmark data are a foundational step to improve psychosocial care for pediatric patients with type 1 diabetes.

Evaluation of volatile organic compound (VOC) emissions from memory foam mattresses and potential implications for consumer health risk

Chemical emissions from two new memory foam mattresses were evaluated in a simulated consumer use environment over the course of 32 days. Passive 12- and 24-h samples (n = 62) were collected for various VOCs. Airborne concentrations of chemicals associated with the mattresses (2-propanol, acetone, chloromethane, toluene, and ΣVOC) peaked during the first day after installation and progressively decayed over the course of the following 31 days. Emission rates were derived using a two-phase, double exponential source decay model paired with a one-compartment generalized indoor air quality model; short- and long-term emission half-lives for individual chemicals were on the order of hours (approximately 4 or 12 h) and days (approximately 24 days), respectively. Model-estimated average ΣVOC concentrations for the 32-day period of the study were approximately 20 and 33 μg/m³ for Mattress 1 and 2, respectively, while the modeled one-year average concentrations were 2.7 and 4.2 μg/m³, respectively. First-year trends for both mattresses were qualitatively similar, with the sum of 2-propanol, acetone, chloromethane, and toluene contributing to approximately 81% and 95% of the first-year ΣVOC concentration of Mattress 1 and 2, respectively. The airborne concentrations of individual chemicals and ΣVOC measured and modeled in this study were well below available health-based benchmarks for individual chemicals and within available indoor air quality recommendations for ΣVOC, suggesting that it is unlikely that the use of the models of mattresses evaluated in this study would pose a health risk to consumers.

Development and Evaluation of the Pediatric Diabetes Routine Questionnaire for Parents of Young Children with Type 1 Diabetes

This study describes the development and psychometric evaluation of the Pediatric Diabetes Routines Questionnaire for Parents of Young Children (PDRQ-PYC) with type 1 diabetes, a measure adapted from the school-age and adolescent versions of the PDRQ, to measure diabetes-specific routines in families with children under age 6 years with type 1 diabetes. Participants included 173 parents of young children with type 1 diabetes (YC-T1D) who completed measures of diabetes-specific routines, diabetes adjustment, self-efficacy, benefit finding, depression, child behavior problems, spousal support, and T1D treatment engagement. Exploratory factor analysis supported a one-factor model consisting of a unidimensional PDRQ-PYC total score. The PDRQ-PYC total score demonstrated good internal consistency, convergent validity, and criterion validity. The present study demonstrates that PDRQ-PYC is a valuable and feasible tool for measuring the consistency and regularity with which families of YC-T1D perform T1D management tasks. Along with the school-age and adolescent versions of the PDRQ, the PDRQ-PYC now provides the ability to assess diabetes-specific routines from early childhood through adolescence and findings support the notion that routines are associated with engagement in diabetes tasks.ClinicalTrials.gov Identifier NCT03222180 (first posted July 19, 2017).

Remedy to Diabetes Distress (R2D2): Development protocol for a scalable screen-to-treat program for families of school-age children

BACKGROUND

School-age children with type 1 diabetes (T1D) need help from parents or other adult caregivers (caregivers) to effectively manage T1D, resulting in greater vulnerability to Diabetes Distress (DD) for both children and caregivers. Unfortunately, there are no scalable screen-to-treat programs for clinics to adopt to identify and treat DD in school-age families.

METHODS AND ANALYSES

We aim to design a scalable, clinic-based screen-to-treat program for DD in families of school-age children and to test whether our new program to reduce caregiver and child DD also reduces child glycemic levels. Our Remedy to Diabetes Distress (R2D2) program will target caregivers and children with T1D who are between 8 and 12 years old. It will merge routine and automated surveillance of DD in the clinical setting with at home digital delivery of a theory-based behavioral and psychological treatment of DD. We will use the ORBIT Model for Behavioral Intervention development to guide four small and cost-effective formative studies to develop our R2D2 program and assess initial treatment effects. In tandem, we will implement clinic-based DD screening in school-age families and assess feasibility and acceptability of our screening platform as a Quality Improvement activity. The study started in September 2020 and is scheduled to conclude in 2025.

CONCLUSIONS

The study will use a single Institutional Review Board (IRB) with Children's Mercy-Kansas City operating as the IRB of record. We will disseminate study results through presentations at scientific conferences and through peer-reviewed journals read by the psychology and diabetes care communities.

The association between pediatric mental health disorders and type 1 diabetes-related outcomes

OBJECTIVE

Transition from pediatric to adult healthcare systems is a difficult process for young adults with Type 1 Diabetes (T1D) and most patients experience a deterioration in disease control. Mental health (MH) disorders are common in individuals with T1D and are believed to play a role in disease control and transition of care. We evaluated the association between the presence of pediatric MH disorder and measures of success in diabetes care in young adults who recently transitioned to adult care.

RESEARCH DESIGN AND METHODS

Retrospective cohort study of young adults in a large adult endocrinology system who transitioned from a pediatric hospital system after 2009. MH disorders were diagnosed by clinical pediatric psychologists during routine care at the pediatric hospital. Measurements of Hemoglobin A1c, diabetes-related emergencies, clinic attendance and intervals in transition were assessed and compared between the pediatric and adult hospital systems.

RESULTS

237 young adults were identified and 100 (42%) of these were diagnosed with a MH disorder during pediatric care. Presence of a MH disorder was associated with higher Hemoglobin A1c levels prior to transition and increased rates of diabetes-related hospitalizations during the transition interval. Patients with a MH disorder were less likely to establish a pattern of consistent follow up after transition (p = 0.021).

CONCLUSIONS

MH disorders are common and predict greater challenges with diabetes management and less effective transition into the adult endocrinology system. Early recognition of MH disorders may allow for allocation of more proactive and intensive support for affected patients.

Erratum: Feasibility of Implementing a Pediatric Diabetes Clinic via Telehealth. Diabetes Spectrum 2021;34:190-197 (https://doi.org/10.2337/ds20-0060)

[This corrects the article on p. 190 in vol. 34, PMID: 34149260.].

Feasibility of Implementing a Pediatric Diabetes Clinic via Telehealth

OBJECTIVE

In response to the coronavirus disease 2019 (COVID-19) pandemic and social distancing guidelines, our pediatric diabetes team rapidly changed the format of conducting diabetes clinic from in person to telehealth. We compared the actual number and rate of completed, canceled, and no-show visits between an 8-week period in 2019, when we exclusively conducted visits in person and the same 8-week period in 2020, during the COVID-19 quarantine, when we exclusively conducted visits via telehealth.

METHODS

We used electronic health record data for all patients, as well as Dexcom continuous glucose monitoring data collected for a subset of youths during the COVID-19 quarantine and the immediate pre-COVID-19 period.

RESULTS

Although there was a difference in the absolute number of in-person versus telehealth visits canceled during these two time periods, there was no difference in the rates of completed, canceled, and no-show visits completed in person or via telehealth. This finding suggests that, despite a rapid shift to a completely new health care delivery model, our providers completed a similar rate of patient care via telehealth during the COVID-19 quarantine and that telehealth may be a feasible method for providing diabetes care. However, our results also suggested that youths' glucose management was less optimal during the quarantine period.

CONCLUSION

COVID-19 presented an opportunity to adopt and test the feasibility of using a telehealth delivery model for routine diabetes care. Yet, to make telehealth a viable treatment delivery alternative will likely involve the uptake of new clinic procedures, investment in institutional infrastructure, and team-based flexibility.

Benefit finding among parents of young children with type 1 diabetes

Benefit finding, perceived positive effects of adversity, has been associated with psychological well-being in people with chronic illnesses and with better adherence for adolescents with type 1 diabetes (T1D). Our qualitative research with parents of young children (< 6 years old) with T1D indicated that benefit finding (BF) is a common parental coping mechanism, but no tools exist to measure BF in parents. We determined psychometric properties of the Diabetes Benefit Finding Scale for Parents (DBFS-P), a 16-item questionnaire adapted from the validated adolescent version. Parents of young children with T1D (n = 172) were participants in a randomized trial of an online intervention. We examined the DBFS-P factor structure through principal component analysis (PCA); internal consistency through Cronbach's alpha; convergent validity via bivariate correlations between the DBFS-P and measures of parental depression, anxiety, T1D self-efficacy, and hypoglycemia fear; and discriminant validity via bivariate correlations between the DBFS-P and measures of parental somatization and child behavior problems. PCA revealed one factor (56.47% variance) with Cronbach's α = 0.95. Convergent validity of the DBFS-P was supported by significant correlations with parental depression (r = -0.35, P < 0.001), anxiety (r = -0.20, P = 0.008), T1D self-efficacy (r = 0.36, P < 0.001), and hypoglycemia fear (r = 0.27, P < 0.001). Non-significant correlations with parental somatization (r = -0.06, P = 0.42) and child behavior problems (r = -0.12, P = 0.14) support its discriminant validity. The DBFS-P demonstrated good psychometric properties as a tool for assessing BF among caregivers.

Health Care Transition for Young Adults With Type 1 Diabetes: Stakeholder Engagement for Defining Optimal Outcomes

Objectives

Research on the transition to adult care for young adults with type 1 diabetes (T1D) emphasizes transition readiness, with less emphasis on transition outcomes. The relatively few studies that focus on outcomes use a wide variety of measures with little reliance on stakeholder engagement for measure selection.

Methods

This study engaged multiple stakeholders (i.e., young adults with T1D, parents, pediatric and adult health care providers, and experts) in qualitative interviews to identify the content domain for developing a multidimensional measure of health care transition (HCT) outcomes.

Results

The following constructs were identified for a planned measure of HCT outcomes: biomedical markers of T1D control; T1D knowledge/skills; navigation of a new health care system; integration of T1D into emerging adult roles; balance of parental involvement with autonomy; and "ownership" of T1D self-management.

Discussion

The results can guide creation of an initial item pool for a multidimensional profile of HCT outcomes.

The Ups and Downs of Parenting Young Children With Type 1 Diabetes: A Crowdsourcing Study

Objectives

Parenting young children with type 1 diabetes (YC-T1D) entails pervasive challenges; parental coping may influence child and parent outcomes. This study used a qualitative descriptive design to describe these challenges comprehensively to inform the user-centered design of an Internet coping resource for parents.

Methods

A "Parent Crowd" of 153 parents of children with T1D onset at ≤ 5 years old submitted textual responses online to open-ended questions about parenting YC-T1D. Systematic coding organized responses into domains, themes, and examples. A supplemental focus group of racial/ethnic minority parents enhanced the sample's diversity and validated findings from the Parent Crowd.

Results

Similar domains and themes emerged from responses of crowdsourcing and focus group participants. In each domain, parenting YC-T1D was challenging, but there was also substantial evidence of positive coping strategies and adaptability.

Conclusions

The study yielded rich data to inform user-centered design of an Internet resource for parents of YC-T1D.

Type 1 diabetes in very young children: a model of parent and child influences on management and outcomes

The incidence of type 1 diabetes (T1D) in very young children (YC-T1D) is increasing globally. Managing YC-T1D is challenging from both a medical and psychosocial perspective during this vulnerable developmental period when complete dependence upon parental caretaking is normative and child behavior is unpredictable. The consequences of suboptimal glycemic control during this age range are substantial since these children will have T1D for many years and they are prone to adverse neuropsychological sequelae. Poor adaptation to T1D during these early years may engender a persistent trajectory of negative outcomes that can be very resistant to change. The empirical research on the YC-T1D population (age <6 yr) has indicated multiple mechanisms through which parent characteristics, parent coping skills, and child characteristics interact to yield a pattern of T1D management behaviors that affect T1D outcomes. However, this research has not yet led to a well-conceived conceptual model for identifying and understanding these mechanisms or for specifying research gaps and future research directions. The aim of this review is to propose such a conceptual model linking parent characteristics, parent coping, and child characteristics to T1D management behaviors and outcomes. This article reviews the literature focusing on research pertinent to YC-T1D and elements of our proposed model, identifies and discusses gaps in the literature, offers directions for future research, and considers a range of possible interventions targeting the unique needs of this special population.

School-based Screening to Identify Children At Risk for Attention-Deficit/Hyperactivity Disorder: Barriers and Implications

This report describes a school-based screening project to improve early identification of children at risk for attention-deficit/hyperactivity disorder (ADHD) and communicate these concerns to parents, recommending that they contact their child's primary care provider (PCP). Of 17,440 eligible children in first through fifth grades in five school districts, 47.0% of parents provided required written consent, and teachers completed 70.4% of the online screeners (using the Vanderbilt AD/HD Diagnostic Teacher Rating Scale). Of 5,772 screeners completed, 18.1% of children (n = 1,044) were identified as at risk. Parents of at-risk children were contacted to explain risk status and recommended to visit their child's PCP for further evaluation. It was not possible to contact 39.1% of parents of at-risk children. Of the 636 parents of at-risk children who could be contacted, 53.1% (n = 338) verbally accepted the recommendation to follow-up with their PCP, which was not related to ADHD symptom severity. Parents of children with IEPs or related services were more likely to accept the recommendation to visit the PCP. Our exploration of the potential for school-based screening for ADHD identified a number of barriers to successful execution, but the data also indicated that this is an important problem to address.

Topical Review: Advancing Research on the Transition to Adult Care for Type 1 Diabetes

OBJECTIVE

To acknowledge and address the gaps in health care transition (HCT) in type 1 diabetes (T1D) literature by proposing an expanded model that could guide future research.

METHOD

Topical literature review.

RESULTS

Empirical research examining the outcomes of HCT in T1D is limited by methodological and interpretive problems. The relevant evidence indicates that HCT outcomes are both multi-systemic and multidimensional; the authors propose an expanded model that incorporates multiple stakeholder perspectives of HCT outcomes.

CONCLUSIONS

The development and validation of a standard index of HCT outcomes based on the expanded model of HCT outcomes could provide a means for assessing relations between HCT readiness and outcomes, facilitate the design of longitudinal studies to determine the predictive validity of HCT readiness assessment and the efficacy of HCT interventions, and inform the design and evaluation of appropriate interventions targeting those mechanisms.

Characterization of formaldehyde exposure resulting from the use of four professional hair straightening products

An exposure simulation study was conducted to characterize potential formaldehyde exposures of salon workers and clients during keratin hair smoothing treatments. Four different hair treatment brands (Brazilian Blowout, Coppola, Global Keratin, and La Brasiliana) were applied to separate human hair wigs mounted on mannequin heads. Short-term (6-16 min) and long-term (41-371 min) personal and area samples (at distances of 0.5 to 3.0 m from the source) were collected during each treatment for the 1-day simulation. A total of 88 personal, area, and clearance samples were collected. Results were analyzed based on task sampling (blow-dry, flat-iron), treatment sampling (per hair product), and time-weighted averages (per hair treatment, four consecutive treatments). Real-time monitoring of tracer gas levels, for determining the air exchange rate, and formaldehyde levels were logged throughout the simulation. Bulk samples of each hair treatment were collected to identify and quantify formaldehyde and other chemical components that may degrade to formaldehyde under excessive heat. Mean airborne concentrations of formaldehyde ranged from 0.08-3.47 ppm during blow-dry and 0.08-1.05 ppm during flat-iron. During each treatment, the mean airborne concentrations ranged from 0.02-1.19 ppm throughout different zones of the salon. Estimated 8-hr time-weighted averages for one treatment per day ranged from 0.02 ppm for La Brasiliana to 0.08-0.16 ppm for Brazilian Blowout. For four treatments per day, means ranged from 0.04-0.05 ppm for La Brasiliana to 0.44-0.75 ppm for Brazilian Blowout. Using all four products in one day resulted in estimated 8-hr time-weighted averages ranging from 0.17-0.29 ppm. Results from bulk sampling reported formaldehyde concentrations of 11.5% in Brazilian Blowout, 8.3% in Global Keratin, 3% in Coppola, and 0% in La Brasiliana. Other products that degrade into formaldehyde were detected in Global Keratin, Coppola, and La Brasiliana. The results of this study show that professional hair smoothing treatments--even those labeled "formaldehyde-free"--have the potential to produce formaldehyde concentrations that meet or exceed current occupational exposure limits.

Enhanced tumor cures after Foscan photodynamic therapy combined with the ceramide analog LCL29. Evidence from mouse squamous cell carcinomas for sphingolipids as biomarkers of treatment response

To improve anticancer therapeutic success of photodynamic therapy (PDT), combination treatments represent a viable strategy. Sphingolipid analogs combined with anticancer drugs can enhance tumor response. We have shown that LCL29, a C6-pyridinium ceramide, promotes therapeutic efficacy of Photofrin-PDT in mouse SCCVII squamous cell carcinoma tumors. The long-term effect of the combination PDT + LCL29 is unknown. In this study we used the same model to test the long-term curative potential of Foscan-PDT + LCL29. We show that treatment of SCCVII tumors with the combination led to enhanced long-term tumor cure compared to PDT alone. LCL29 itself did not prevent tumor growth. All treatments triggered early increases in tumor-associated C16-ceramide, C18-ceramide, dihydrosphingosine, and global levels of dihydroceramides. PDT-evoked increases in tumor-associated sphingosine-1-phosphate and dihydrosphingosine-1-phosphate remained elevated or were attenuated after the combination, respectively; in contrast, LCL29 had no effect on these two sphingolipids. Our data demonstrate that adjuvant LCL29 improves PDT long-term therapeutic efficacy, implying translational potential of the combination. Furthermore, our findings indicate that changes in the sphingolipid profile might serve as predictive biomarkers of tumor response to treatments.

Designing a successful HMD-based experience

For entertainment applications, a successful virtual experience based on a head-mounted display (HMD) needs to overcome some or all of the following problems: entering a virtual world is a jarring experience, people do not naturally turn their heads or talk to each other while wearing an HMD, putting on the equipment is hard, and people do not realize when the experience is over. In the Electric Garden at SIGGRAPH 97, we presented the Mad Hatter's Tea Party, a shared virtual environment experienced by more than 1,500 SIGGRAPH attendees. We addressed these HMD-related problems with a combination of back story, see-through HMDs, virtual characters, continuity of real and virtual objects, and the layout of the physical and virtual environments.

A model of parasagittal controlled cortical impact in the mouse: cognitive and histopathologic effects

Controlled cortical impact (CCI), using a pneumatically driven impactor to produce traumatic brain injury, has been characterized previously in both the ferret and in the rat. In the present study, we applied this technique to establish and characterize the CCI model of brain injury in another species, the mouse, evaluating cognitive and histopathologic outcome. In anesthetized (sodium pentobarbital, 65 mg/kg) male C57BL mice, we performed sham treatment (no injury, n = 12) or CCI injury (n = 12) at a velocity of 5.7-6.2 m/sec and depth of 1 mm, using a 3-mm diameter rounded-tip impounder, positioned over the left parietotemporal cortex (parasagittal). At this level of injury, we observed highly significant deficits in memory retention of a Morris water maze task 2 days following injury (p < 0.001). Postmortem histopathologic analysis performed at 48 h following injury revealed substantial cortical tissue loss in the region of impact and selective hippocampal neuronal cell loss in the CA2, CA3, and CA3c regions, using Nissl staining. Analysis of degenerating neurons using modified Gallyas silver staining techniques demonstrated consistent ipsilateral injury of neurons in the cortex adjacent to the impact site and in the dentate gyrus of the ipsilateral hippocampus. Bilateral degeneration was observed at the gray matter-white matter interface along the corpus callosum. Glial fibrillary acidic protein (GFAP) immunohistochemistry revealed extensive reactive gliosis appearing diffusely through the bilateral cortices, hippocampi, and thalami at 48 h postinjury. Breakdown of the blood-brain barrier was demonstrated with antimouse IgG immunohistochemistry, revealing extravasation of endogenous IgG throughout the ipsilateral cortex, hippocampus, and thalamus. These results suggest that this new model of parasagittal CCI in the mouse mimics a number of well-established sequelae observed in previously characterized brain injury models using other rodent species. This mouse model may be a particularly useful experimental tool for comparing behavioral and histopathologic characteristics of traumatic brain injury in wild-type and genetically altered mice.

Breast cancer surgery: understanding the story

1. Research has shown that mastectomy, with or without reconstruction, is no more effective in the long run than breast conservation and irradiation. Therefore, the important factor seems to be choice. 2. A Halsted radical mastectomy involves the removal of the whole breast along with the pectoralis major and minor muscles and a complete axillary dissection. A modified radical mastectomy involves removal of the whole breast and most or all of the axillary lymph nodes, but preserves the pectoralis major muscle. 3. Breast preserving strategies remove the malignant cells and minimal surrounding tissue. These segmental resections include lumpectomy, quadranectomy, and wedge resection along with axillary node dissection.

Effect of ionic strength on the binding of Sindbis virus to chick cells

Sindbis virus can adsorb to chicken embryo fibroblasts in two different ways. "Loosely" bound virus can be washed off the cell with buffers of ionic strength 0.2 or greater, whereas "tightly" bound virus remains attached under these conditions. When Sindbis virus is adsorbed to chick cells at 4 C from a buffer of ionic strength 0.17, 40 to 50% of the adsorbed virus is loosely bound, the remainder tightly bound. Infection of chick cells by Sindbis virus has only small effects on the total amount of virus that can be bound to the cells. However, the amount of Sindbis virus that can be tightly bound declines rapidly beginning at 2 to 3 h after infection. By 7 h after infection, the amount of virus that can be tightly bound is only 10 to 20% of the amount bound to uninfected cells. The adsorption (and penetration) of virus at 37 C is most efficient at an ionic strength of 0.15 to 0.17; at this ionic strength most of the adsorbed virus is tightly bound. At higher ionic strengths the virus adsorbs poorly. At lower ionic strengths most of the virus is loosely bound. A second enveloped virus, vesicular stomatitis virus, has been studied for the purposes of comparison; its adsorption behavior differs from that of Sindbis virus.

Thermal inactivation of Newcastle disease virus. I. Coupled inactivation rates of hemagglutinating and neuraminidase activities

The thermal stability of Newcastle disease virus has been characterized in terms of the rate constants for inactivation of hemagglutinating activity (HA), neuraminidase activity (NA), and infectivity. Inactivation of HA results in the concomitant loss of NA. Infectivity, however, is much more thermolabile. Disintegration of the virus particle is not responsible for the identical rate constants for inactivation of HA and NA, nor is their parallel inactivation uncoupled in envelope fragments produced by pretreating the virus with phospholipase-C. The data indicate that a common envelope factor(s) can influence the thermal stability of both activities.