Search

Prussian blue analogues (PBAs) show great potential for low-energy Faradaic deionization (FDI) with reversible Na-ion capacity approaching 5 M in the solid-state. However, past continuous-flow demonstrations using PBAs in FDI were unable to desalinate brackish water to potable levels using single-pass architectures. Here, we show that recirculation of effluent from a symmetric cation intercalation desalination cell into brine/diluate reservoirs enables salt removal exceeding 80% at thermodynamic efficiency as high as 80% when cycled with 100 mM NaCl influent and when controlled by a low-volume, automated fluid circuit. This exceptional performance is achieved using a novel heated, alkaline wet phase inversion process that modulates colloidal forces to increase carbon black aggregation within electrode slurries to solidify crack-free, high areal-capacity PBA electrodes that are calendered to minimize cell impedance and electrode porosity. The results obtained demonstrate the need for co-design of auxiliary fluid-control systems together with electrode materials to advance FDI beyond brackish salinity.

Abstract Background Community Paramedics (CPs) require access to timely blood analysis in the field to guide treatment and transport decisions. Point of care testing (POCT), as opposed to laboratory analysis, may offer a solution, but limited research exists on CP POCT. The purpose of this study was to compare the validity of two devices (Abbott i-STAT® and Alere epoc®) by CPs in the community. Methods In a CP programme responding to 6000 annual patient care events, a split sample validation of POCT against traditional laboratory analysis for seven analytes (sodium, potassium, chloride, creatinine, hemoglobin, hematocrit, and glucose) was conducted on a consecutive sample of patients. The difference of proportion of discrepant results between POCT and laboratory was compared using a two sample proportion test. Usability was analysed by survey of CP experience, a linear mixed effects model of Systems Usability Scale (SUS) adjusted for CP clinical and POCT experience, an expert heuristic evaluation of devices, a review of device-logged errors, and coded observations of POCT use during quality control testing. Results Of 1649 episodes of care screened for enrollment, 174 required a blood draw, with 108 episodes (62.1%) enrolled from 73 participants. Participants had a mean age of 58.7 years (SD16.3); 49% were female. In 4 of 646 (0.6%) comparisons, POCT reported a critical value but the laboratory did not; with no statistically significant (p = 0.323) difference between i-STAT® (0.9%;95%CI:0.0,1.9%) compared with epoc® (0.3%;95%CI:0.0,0.9%). There were no instances of the laboratory reporting a critical value when POCT did not. In 88 of 1046 (8.4%) comparisons the a priori defined acceptable difference between POCT and the laboratory was exceeded; occurring more often in epoc® (10.7%;95%CI:8.1,13.3%) compared with i-STAT® (6.1%;95%CI:4.1,8.2%)(p = 0.007). Eighteen of 19 CP surveys were returned, with 11/18 (61.1%) preferring i-STAT® over epoc®. The i-STAT® had a higher mean SUS score (higher usability) compared with epoc® (84.0/100 vs. 59.6/100; p = 0.011). There were no statistically significant differences in device logged errors between i-STAT® and epoc® (p = 0.063). Conclusions CP programmes can expect clinically valid results from POCT. Device usability assessments should be considered with any local implementation as the two POCT systems have different strengths.

Objective: To evaluate whether the presence of patent ductus arteriosus (PDA) in preterm infants worsens long-term neurodevelopmental outcomes., Study Design: This was a secondary observational analysis of data from 1090 preterm low-birthweight infants in the Infant Health and Development Program (IHDP), a multicenter longitudinal cohort study of outcomes assessed from 3 to 18 years of age. Multivariable analysis was adjusted for IHDP treatment group (intervention or follow-up), birth weight, maternal race, maternal education, infant sex, maternal preconception weight, Home Observation Measurement of the Environment (HOME) total score at 12 months, neonatal health index, and gestational age., Results: Of the 1090 patients (49% male) included in the analysis, 135 had a PDA. Mean birth weight (1322 g vs 1871 g; P < .0001) and gestational age (30.2 weeks vs 33.4 weeks, P < .0001) were lower and mean ventilator days (11.8 vs 1.3; P < .0001), vasopressor use (12.6% vs 1.2%; P < .0001), and congestive heart failure (8.9% vs 0.1%; P < .0001) were higher in the PDA group. There were no differences between the PDA and no-PDA groups in maternal education level and HOME total score at age 12 months. Multivariable analysis demonstrated no between-group differences in cognitive development or behavioral competence at age 3, 8, and 18 years., Conclusions: The presence of a PDA in moderately preterm, low-birthweight infants does not impact long-term neurodevelopmental outcomes., (Copyright © 2018 Elsevier Inc. All rights reserved.)

Objectives: To describe health-care spending and utilization for infants discharged from the neonatal intensive care unit (NICU)., Study Design: Retrospective cohort analysis of 4973 NICU graduates in the Truven MarketScan Medicaid database, with follow-up to the third birthday. Health-care spending and utilization after NICU discharge were assessed. Using logistic regression, we assessed clinical characteristics associated with hospitalization and emergency department (ED) visits., Results: Most (69.5%) post-NICU spending occurred within the first year [$33,276 per member per year]. Inpatient care accounted for most (71.6%) of the 3-year spending. The percentages of infants with a 1-year readmission or ED visit were 36.8% and 63.7%, respectively. Medical technology was associated with the highest likelihoods of hospital [aOR 17.8 (95%CI 12.2-26.0)] and ED use [aOR 2.3 (95%CI 1.8-3.0)]., Conclusions: Hospital care accounts for the majority of spending for NICU graduates. Infants with medical technology have the highest risk of hospital and ED use.

Approximately 1 in 8 children in the United States are born preterm. Existing guidelines and research examine the cost of prematurity from the NICU stay and developmental surveillance and outcomes after discharge from the NICU. Preterm children are at greater risk for excess hospitalizations, outpatient visits, and societal costs after NICU discharge. Improved delivery of care and health promotion from the community setting, particularly from the patient-centered medical home, may result in improved growth, health, and development, with accompanying reduction of post-NICU discharge costs and encounters. There has been comparatively little focus on how to promote health and wellness for children born preterm, particularly for community-based providers and payers. Accordingly, health care delivery for NICU graduates is often fragmented, with little guidance on medical management beyond tertiary care follow-up. In this article, we use what is known about chronic care and practice transformation models to present a framework for health care system redesign for children born preterm. We discuss the rationale for NICU graduates as a priority population for health system redesign. Promotion of health and wellness for children born preterm who are discharged to the community setting entails population health management from the patient-centered medical home; comanagement, clinical care protocols, and clinical support from the tertiary care-based tertiary care-based center; and a favorable payer strategy that emphasizes support for chronic care management. Practical suggestions are provided for the practicing physician for the child born preterm as health care systems are redesigned., Competing Interests: POTENTIAL CONFLICT OF INTEREST: The authors have indicated they have no potential conflicts of interest to disclose., (Copyright © 2017 by the American Academy of Pediatrics.)

Background and Objectives: Neonatal hypoglycemia has been associated with abnormalities on brain imaging and a spectrum of developmental delays, although historical and recent studies show conflicting results. We compared the cognitive, academic, and behavioral outcomes of preterm infants with neonatal hypoglycemia with those of normoglycemic controls at 3 to 18 years of age., Methods: A secondary analysis of data from the Infant Health and Development Program, a national, multisite, randomized controlled longitudinal intervention study of long-term health and developmental outcomes in preterm infants. Of the 985 infants enrolled in the Infant Health and Development Program, 745 infants had glucose levels recorded. Infants were stratified into 4 groups by glucose level. By using standardized cognitive, academic, and behavioral assessments performed at 3, 8, and 18 years of age, we compared groups after adjusting for intervention status, birth weight, gestational age, sex, severity of neonatal course, race, maternal education, and maternal preconception weight., Results: No significant differences were observed in cognitive or academic skills between the control and effected groups at any age. Participants with more severe neonatal hypoglycemia reported fewer problem behaviors at age 18 than those without hypoglycemia., Conclusions: No significant differences in intellectual or academic achievement were found between preterm infants with and without hypoglycemia. A statistical difference was found in behavior at age 18, with hypoglycemic children showing fewer problematic behaviors than normoglycemic children. This difference was not clinically meaningful. Using extended outcomes, our results are consistent with previous studies that found no significant neurodevelopmental outcomes associated with neonatal hypoglycemia in preterm-born children., Competing Interests: POTENTIAL CONFLICT OF INTEREST: The authors have indicated they have no potential conflicts of interest to disclose., (Copyright © 2016 by the American Academy of Pediatrics.)

Objective: To assess the long-term cognitive, behavioral and academic status of preterm children exposed to clinical chorioamnionitis., Study Design: In total, 985 infants (<37 weeks and 2500 g at birth) were recruited in a multisite interventional research program. Of these, 43 case-infants were identified based on documented diagnosis of maternal clinical chorioamnionitis. Infants with chorioamnionitis were compared with the remainder of the cohort after controlling for maternal and infant variables. All infants underwent cognitive, behavioral and academic achievement assessments at 3, 8 and 18 years. Standardized cognitive and academic achievement scores were cutoff at 2 s.d.'s below the mean, behavioral scores were cutoff at a T-score >70 and examined with χ(2) statistics. Mean scores were evaluated using preliminary bivariate analysis and were followed by multiple regression models predicting child outcomes., Result: Overall, children with chorioamnionitis did not have lower scores on any assessment at any age. Children without chorioamnionitis performed significantly lower at 8 years on the Woodcock-Johnson reading subscore and the mean score of the Peabody Picture Vocabulary Test (PPVT). No significant difference persisted to 18-year follow-up. In logistic regression, chorioamnionitis independently predicted higher PPVT scores at 8 years, but not lower performance scores on the Woodcock-Johnson reading subscore., Conclusion: Clinical chorioamnionitis was not associated with adverse neurodevelopmental outcomes in this group of preterm infants <37 weeks and 2500 g.

The Medical Home Clinic for Special Needs Children (MHCL) at Arkansas Children's Hospital provides comprehensive care oversight for children with medical complexity (CMC). The objective of this study is to evaluate parent perceptions of health care delivery outcomes after 12 months of enrollment in the MHCL. This is a prospective cohort study of parents of MHCL patients, who completed surveys at initial and 12-month visits. Surveys assessed parent health, child health and function, family stress, and overall satisfaction, using previously validated measures and scales. Paired analyses examined differences in measures between baseline and 12 months. One-hundred and twenty of 174 eligible parents completed the follow-up survey at 12 months. Respondents were 63% White/Caucasian, 90% biological parent, and 48% with an annual family income < $20,000. From baseline to 12 months, a greater number of respondents reported having a care plan (53% vs. 85%, p < .001); fewer respondents needed help with care coordination (78% vs. 31%, p < .001). No changes were seen in reports of having emotional needs met. Parents reported a decline in the physical subscale of the SF-12 Health-Related Quality of Life measure (49.1 vs. 46.4, p < .01), with those parents with ≥ 1 additional child with special needs reporting a marked decline (49.2 vs. 42.5, p < .001). No other changes in family impact were found. We conclude that comprehensive care oversight may improve care coordination for parents of CMC, but no association with improved parent health was found. Future studies should identify the factors that influence parental burden and tailor clinical interventions to address such factors., (PsycINFO Database Record (c) 2013 APA, all rights reserved.)

Objective: To evaluate the effect on all state Medicaid costs of a children's hospital-based multidisciplinary clinic that provides comprehensive and coordinated care for medically complex children., Design: Before-after intervention study. Patients' health care costs for up to 1 year before enrollment in the clinic were compared with patients' health care costs for up to 1 year after enrollment in the clinic. Patients were enrolled in our study from August 2006 to May 2008., Setting: Tertiary care children's hospital in a rural state., Participants: A total of 225 medically complex children who had at least 2 chronic medical conditions and who were followed up by at least 2 pediatric subspecialists., Intervention: Multidisciplinary teams ensure that each patient receives all the necessary medical, nutritional, and developmental care and that there is improved coordination of care with primary care providers, subspecialists, hospitalists, and community-based services., Main Outcome Measures: Using Arkansas Medicaid claims data, we examined the medical costs for all outpatient, inpatient, emergency department, and prescription drug claims. Costs were calculated on a per month per patient basis and summarized for annual costs., Results: The mean annual cost per patient per month decreased by $1766 for inpatient care (P < .001) and by $6.00 for emergency department care (P < .001). Although the cost per patient per month for outpatient claims (P < .05) and prescriptions (P < .001) increased, the overall cost to Medicaid per patient per month decreased by $1179 (P < .001)., Conclusions: This hospital-based multidisciplinary clinic resulted in a significant decrease in total Medicaid costs for medically complex children.

Objective: In this study we used national data to determine changes in the prevalence of hospital admissions for medically complex children over a 15-year period., Patients and Methods: Data from the Nationwide Inpatient Sample, a component of the Healthcare Cost and Utilization Project, was analyzed in 3-year increments from 1991 to 2005 to determine national trends in rates of hospitalization of children aged 8 days to 4 years with chronic conditions. Discharge diagnoses from the Nationwide Inpatient Sample were grouped into 9 categories of complex chronic conditions (CCCs). Hospitalization rates for each of the 9 CCC categories were studied both individually and in combination. Trends of children hospitalized with 2 specific disorders, cerebral palsy (CP) and bronchopulmonary dysplasia, with additional diagnoses in more than 1 CCC category were also examined., Results: Hospitalization rates of children with diagnoses in more than 1 CCC category increased from 83.7 per 100,000 (1991-1993) to 166 per 100 000 (2003-2005) (P[r]<.001). The hospitalization rate of children with CP plus more than 1 CCC diagnosis increased from 7.1 to 10.4 per 100 000 (P=.002), whereas the hospitalization rates of children with bronchopulmonary dysplasia plus more than 1 CCC diagnosis increased from 9.8 to 23.9 per 100,000 (P<.001)., Conclusions: Consistent increases in hospitalization rates were noted among children with diagnoses in multiple CCC categories, whereas hospitalization rates of children with CP alone have remained stable. The relative medical complexity of hospitalized pediatric patients has increased over the past 15 years.

The ACH Medical Home Program serves as a comprehensive, multi-discipline clinic and program designed to facilitate comprehensive, coordinated care to the most medically complex and fragile children in Arkansas. In partnership with the family, the PCP and the subspecialty physicians, the program strives to ensure that the ideals of providing the "medical home" are accomplished, both in the community and at Arkansas Children's Hospital. An ongoing evaluation process has been implemented and it is the hope and mission of this program to evolve to provide the highest quality of care and highest quality of life for these children with complex medical conditions and for their families. Referrals and inquiries are welcomed and encouraged and can be made at (501) 364-3030.

Within 24 h of hormonally stimulated 3T3-L1 adipocyte differentiation, there are dramatic changes in the protein levels of p130 and p107, two members of the retinoblastoma tumor suppressor gene family. Designated the "p103:p107" switch, this alteration is characterized by a rapid and transient drop in p130 protein levels accompanied by a transient increase in both p107 mRNA and protein levels. Using protease inhibitors, the specific proteolytic pathway involved in degradation of p130 was examined. Treatment of cells with N-acetyl-leu-leu-norleucinal, an inhibitor that blocks proteolytic activity of type I calpain and the 26S proteasome, resulted in a complete block in the degradation of p130 protein, as well as adipocyte differentiation, suggesting that one of these pathways is involved in regulating p130 protein levels. Similar analysis with lactacystin, a specific inhibitor of the 26S proteasome, also resulted in a complete block in both differentiation and p130 degradation. Furthermore, both inhibitors blocked the increase in p107 protein levels normally observed on Day 1, suggesting that the p130:p107 switch is required for adipocyte differentiation and one of the early molecular events involved in activating the p130:p107 switch is the specific degradation of p130 by the 26S proteasome.

The murine 3T3-L1 preadipocyte cell line is well characterized for its capacity to undergo differentiation into adipocytes under appropriate hormonal stimulation. p107, a member of the retinoblastoma tumor suppressor gene family has been shown to be dramatically upregulated during the early requisite clonal expansion phase of 3T3-L1 adipogenesis; however, a functional consequence has yet to be described. A phosphorothioate antisense RNA approach was utilized to determine if inhibition of p107 expression would block or perturb adipocyte differentiation. A series of three phosphorothioate oligonucleotides in antisense orientation was generated, designated AS1, AS2, and AS3 along with a sense control oligonucleotide complementary to AS1 and added to postconfluent cells at a concentration of 20 and 50 microM throughout hormonally stimulated differentiation. Treatment of cells with either concentration of the sense, AS1, AS2, or 20 microM AS3 oligonucleotides had little effect on either Oil Red O lipid accumulation or induction of p107 protein levels. In contrast, treatment with 50 microM AS3 inhibited the increase in p107 protein levels and led to a complete block in differentiation as detected by Oil Red O lipid accumulation and inhibition of adipocyte-specific mRNA expression. In addition, treatment with AS3 led to a significant inhibition of cellular proliferation associated with clonal expansion. Combined, these results provide strong evidence supporting a functional role for p107 in 3T3-L1 adipocyte differentiation., (Copyright 2001 Academic Press.)

Leptin, the recently cloned product of the obese (ob) gene, is a 16 kDa-protein that acts as a circulating satiety factor. It also serves to regulate energy expenditure and may act as a counter regulatory hormone to insulin. Initially thought to be exclusively produced by mature adipocytes, its mRNA has now been identified in significant levels in the placenta as well as the fetus raising speculation regarding its importance as a growth factor. Given studies demonstrating that exclusively breast-fed infants are leaner due to decreased energy intakes than formula-fed infants, we hypothesized that the presence of leptin in human milk could participate in mediating the earlier satiety of those infants fed human milk. We undertook this initial study to qualitatively examine the presence of leptin in human milk utilizing an immunoblot approach. Random milk samples during the first 2 weeks of lactation were available for study from 4 mothers delivering at term. Milk samples were centrifuged, the aqueous layer removed, and the protein content quantitated. One-hundred micrograms of total protein were separated by sodium dodecyl sulfate-polyacrylamide-gel electrophoresis (SDS-PAGE), transferred to nitrocellulose, and immunoblotted with an antileptin antibody. As controls, recombinant human leptin alone and a sample of milk containing added leptin were similarly electrophoresed and immunoblotted. Labeled proteins were visualized by chemiluminescence. Significant amounts of leptin protein were identified in all milk samples examined. No difference in protein detection was identified in fresh milk vs. frozen milk, and little difference was apparent in foremilk samples vs. hindmilk samples. These preliminary data reveal the presence of leptin in term human milk and suggest that further studies to document bioactivity of milk-derived leptin are warranted.

The effect of estrogen (E) and progesterone (P) on the protein expression of the rate-limiting enzyme in serotonin synthesis, tryptophan hydroxylase (TPH), and the level of serotonin in the hypothalamic terminal field was examined in guinea pigs. In addition, we questioned whether serotonin neurons of guinea pigs contain ovarian steroid receptors (estrogen receptoralpha[ERalpha], estrogen receptor beta[ERbeta], progestin receptors [PRs]) that could directly mediate the actions of E or P. Western blot and densitometric analysis for TPH were used on raphe extracts from untreated-ovariectomized (OVX), OVX-E-treated (28 d), and OVX-E+P-treated (14 d E+14 d E+P) guinea pigs. The medial basal hypothalami from the same animals were extracted and subjected to high-performance liquid chromatography analysis for serotonin, dopamine, 5-hydroxyindole acetic acid, and homovanillic acid. The brains from other animals treated in an identical manner were perfusion fixed and examined for the colocalization of ERalpha plus serotonin and PR plus serotonin with double immunohistochemistry or for expression of ERbeta mRNA with in situ hybridization. E and E+P treatment significantly increased TPH protein levels compared to the untreated control group (p < 0.05), but TPH levels were similar in the E and E+P-treated groups. By contrast, serotonin (nanogram/milligram of protein) in the hypothalamus was significantly increased by E+P treatment, but not by E alone. Neither ERalpha nor PR proteins were detected within serotonin neurons of the guinea pig raphe nucleus. However, ERbeta mRNA was expressed in the dorsal raphe. In summary, E alone increased TPH protein expression and the addition of P had no further effect, whereas E+P increased hypothalamic serotonin and E alone had no effect. The localization of ERbeta, but not ERalpha or PR, in the dorsal raphe nucleus suggests that E acting via ERbeta within serotonin neurons increases expression of TPH, but that P acting via other neurons and transsynaptic stimulation may effect changes in TPH enzymatic activity, which in turn, would lead to an increase in serotonin synthesis.

Significant advances have been made recently toward understanding the molecular events that regulate adipocyte differentiation. In vitro models of adipogenesis, such as the 3T3-L1 and F-442A preadipocyte cell lines have proven to be an invaluable resource in elucidating mechanisms of adipocyte differentiation. Subject to modulation by hormonal, dietary, and genetic influences, the differentiation program now appears to be distinctly controlled through the coordinate regulation of transcription factors that predominantly include members of the C/EBP and PPAR families. Increased understanding of these critical factors and how they are regulated will provide insights into adipose tissue development as well as treatment of obesity.

The potential of infant diet to influence fat cell development has largely been examined in clinical studies with conflicting results. In this study, the direct effects of two standard infant formulas, Enfamil and Similac, as well as human milk were examined using a well characterized model of adipocyte differentiation, the 3T3-L1 murine preadipocyte cell line. After exposure to a hormonal regimen of insulin, dexamethasone, and 1-methyl-3-isobutylmethylxanthine, these cells undergo a mitotic expansion phase followed by terminal differentiation. On d 4 of hormonal exposure, greater than 95% of 3T3-L1 cells exhibit the morphologic and biochemical characteristics of mature adipocytes. In this study, cells were exposed to control medium, or control medium supplemented with either 10% Enfamil, 10% Similac, 10% human milk (skim or whole), or the standard hormonal regimen. Oil Red O-detectable lipid accumulation, immunocytochemical cell proliferation assays, and activated expression of adipocyte differentiation-specific mRNAs by Northern blot analysis were used to assess the effects of treatment on adipocyte differentiation. Results from each level of assessment revealed that both Enfamil and human milk were as effective as the standard hormonal regimen at stimulating adipocyte differentiation. In contrast, results from treatment with Similac or human skim milk were indistinguishable from control unstimulated cells. This study, demonstrating that Enfamil and human milk are capable of independently inducing in vitro adipocyte differentiation, suggests that diet during infancy could influence body fat development.

The inhibitory effects of TNFalpha on adipocyte differentiation are well described, however, the mechanisms are poorly understood. Early during hormonally-induced 3T3-L1 preadipocyte differentiation there is a requisite mitotic clonal expansion phase that is associated with significant regulation in p130 and p107 protein levels, two members of the retinoblastoma protein family that regulate cell cycle events through interactions with the E2F transcription factors. This regulation occurs within the first 24 hours of differentiation (Day 1) and is characterized by a transient increase in p107 protein and mRNA levels as well as a transient decrease in p130 protein levels. Here we describe that TNFalpha disrupts the normal pattern of expression of both p130 and p107 proteins, leading to a complete block in mitotic clonal expansion. Interestingly, TNFalpha-treated cells enter S-phase as determined by 5-bromo-2'-deoxyuridine uptake experiments, but rather than completing cell cycle, they are stimulated to undergo apoptosis., (Copyright 1998 Academic Press.)

The homeobox family of proteins are transcription factors are known to be important during the differentiation of a variety of mammalian tissues, however, expression of the genes encoding homeobox proteins during adipogenesis or in adipose tissue has not been described. To investigate whether members of the homeobox gene family are expressed and regulated during adipocyte differentiation, RNA was isolated from 3T3-L1 preadipocyte cells during the hormonal induced differentiation of this cell line into adipocytes. A reverse transcriptase-polymerase chain reaction strategy using degenerate oligonucleotide primers complementary to the highly conserved homeodomain resulted in the identification of 10 different homeobox genes expressed during 3T3-L1 adipogenesis. One of the clones appears to be unique and 9 of the clones represented known members of the homeobox gene family. Examination of the relative mRNA levels encoding these proteins by ribonuclease protection assay during adipocyte differentiation revealed that 3 members, Hox a4, Hox a7, and Hox d4, are regulated as a function of adipocyte development. Further examination of RNA isolated from murine retroperitoneal adipose tissue revealed that these three regulated homeobox mRNAs are expressed in vivo. Combined, these results suggest that members of the homeobox gene family may serve an important role during the differentiation of adipocytes.

During 3T3-L1 adipocyte differentiation, growth-arrested, postconfluent preadipocytes are required to reenter the cell cycle and proceed through a mitotic clonal expansion phase prior to terminal differentiation. The retinoblastoma proteins (pRB, p107, and p130) are thought to be critical in controlling cell cycle progression by binding to and regulating the activity of the E2F transcription factors. We show here that p130/p107 protein levels, p107 mRNA levels, and E2F DNA binding complexes are regulated during 3T3-L1 adipogenesis. The predominant E2F binding complex in day 0 preadipocytes was p130-E2F with no detectable free E2F or p107. On Day 1, during mitotic clonal expansion, there was a distinct switch to free E2F and p107-E2F complexes associated with increased p107 mRNA and protein along with decreased p130 protein levels. Following differentiation, the day 0 pattern is reestablished. The switch is not just a consequence of reentry into the cell cycle, in that p107 protein levels are both detectable and unchanged in dividing, serum-restricted, or serum restimulated preconfluent cells. Interestingly, hormonal stimulation of 3T3-C2 cells, a related nondifferentiating cell line, also induces a mitotic clonal expansion phase that is associated with the p130:p107 switch in a pattern very similar to 3T3-L1 cells, suggesting the block in differentiation observed in 3T3-C2 cells occurs after clonal expansion. Combined, these findings suggest that the regulatory mechanisms of the p130:p107 switch are not specific to differentiation but may play a key role in regulating the mitotic clonal expansion necessary for adipocyte differentiation in 3T3-L1 cells.

The Differentiation-Specific Element Binding Protein (DSEB) was identified by binding to a specific cis-acting DNA element (DSE) responsible for the irreversible continued expression of the angiotensinogen gene after differentiation of 3T3-L1 adipoblasts to adipocytes. It was also identified as the large subunit of the Replication Factor C complex. During 3T3-L1 adipoblast differentiation, DSEB is induced early and interacts with the DSE that is essential for the sustained transcriptional activation of the angiotensinogen gene. Here we describe loss of function studies in 3T3-L1 cells performed with antisense phosphorothioate oligonucleotides that hybridize to DSEB mRNA. Treatment with 15, 25, and 50 microM antisense DSEB resulted in a dose-dependent inhibition of differentiation-specific lipid accumulation after 3 days of hormonal stimulation. Similar treatment also markedly reduced differentiation-dependent expression of mRNAs encoding angiotensinogen and the fat-specific fatty acid binding protein, aP2. Further, 50 microM antisense DSEB treatment resulted in a significant approximately 50% inhibition of the cell proliferation that occurs early in 3T3-L1 adipogenesis. Control experiments using the DSEB sense oligonucleotide had no effect on hormonal-stimulated adipocyte differentiation. Combined, these results suggest that DSEB serves an important role during the proliferative phase of 3T3-L1 adipoblast differentiation.

Bronchopulmonary dysplasia (BPD), the most common cause of chronic lung disease in prematurely born infants, is histologically characterized by various degrees of airway and alveolar septal fibrosis. Tryptase, a serine protease specific to mast cells, has been shown to have potent fibroblast mitogenic properties and in addition has been shown to be increased in adult fibrotic lung disorders. Based on this analogy, the distribution of pulmonary mast cells exhibiting tryptase immunoreactivity was investigated by immunoperoxidase staining in autopsy specimens of infants dying with BPD. Morphologically normal lung specimens from similarly aged infants dying of sudden infant death syndrome (SIDS) served as controls. Tryptase-positive mast cell counts were performed at 250x from at least 10 random fields in bronchial, peribronchiolar, and alveolar regions. Compared to controls, in lung sections exhibiting typical histologic features of long-standing BPD, tryptase positive cells were significantly increased in bronchial (23.9 +/- 3.6 vs 14.4 +/- 2.3) and peribronchiolar (15.3 +/- 3.2 vs 4.63 +/- 0.6) regions compared to controls (P < 0.05, Student's t test). In particular, alveolar regions exhibiting moderate to severe degrees of septal fibrosis exhibited a dramatic increase in the number of tryptase-positive cells (9.83 +/- 1.89 vs 0.34 +/- 0.18, P = 0.003). These findings of a tryptase-positive mast cell hyperplasia in BPD suggest potential roles of mast cells as well as tryptase in the pathogenesis of this disease.

A quasi-valence number of less than 3.20 was reported to be significant in correlating carcinogenicity. This criterion has no meaningful relationship since such a large proportion of organic compounds fall in this group that it provides no selectivity.

The addition of a chiral alcohol, such as l-menthol or R-(-)-2-octanol, to an achiral nitrosamine causes a dissymmetric perturbation of the symmetrical chromophore and a Cotton effect is evident in the circular dichroism curve at the wavelength of ultraviolet absorption of the nitrosamine function. The intensity (ellipticity) of this induced circular dichroism is concentration dependent and appears to result from a weak 1:1 complex of nitrosamine and alcohol. The implications of these observations for structural studies are considered.

The mutagenicity of a non-carcinogenic nitrosamine, N,N-dibenzylnitrosamine (I), and a chemically synthesized alpha-acetoxy derivative, N-(alpha-acetoxy-benzyl)-N-benzylnitrosamine (II), has been examined in Salmonella typhimurium TA100 and TA1535. Compound (I) was non-mutagenic when tested directly or in the presence of a metabolic activation system while (II) was highly mutagenic when tested directly. This is the first report on the conversion of a non-mutagenic N-nitrosamine to a mutagen by the formation of an alpha-acetoxy derivative.

Several compounds having portions of the camptothecin ring system were prepared. These compounds were screened against L1210 lymphoid leukemia with negative results. Two of the analogs which contained the pyridine and hydroxylactone D and E rings were also screened for inhibition of DNA and RNA syntheses in HeLa cells. Each of these analogs had decreased activity as compared with comptothecin and there was no degradation of DNA in the HeLa cells. This suggest that the D and E rings are not a sufficient requirement for camptothecin-like activity.