bluuebunny/crossref_metadata_2025_split huggingface dataset:
Growth Hormone and Insulin-Like Growth Factor-I in the Transition from Normal Mammary Development to Preneoplastic Mammary Lesions
Authors: Kleinberg David L. , Wood Teresa L. , Furth Priscilla A. , Lee Adrian V. 
Published: February 2009

AbstractAdult female mammary development starts at puberty and is controlled by tightly regulated cross-talk between a group of hormones and growth factors. Although estrogen is the initial driving force and is joined by luteal phase progesterone, both of these hormones require GH-induced IGF-I in the mammary gland in order to act. The same group of hormones, when experimentally perturbed, can lead to development of hyperplastic lesions and increase the chances, or be precursors, of mammary carcinoma. For example, systemic administration of GH or IGF-I causes mammary hyperplasia, and overproduction of IGF-I in transgenic animals can cause the development of usual or atypical hyperplasias and sometimes carcinoma. Although studies have clearly demonstrated the transforming potential of both GH and IGF-I receptor in cell culture and in animals, debate remains as to whether their main role is actually instructive or permissive in progression to cancer in vivo. Genetic imprinting has been shown to occur in precursor lesions as early as atypical hyperplasia in women. Thus, the concept of progression from normal development to cancer through precursor lesions sensitive to hormones and growth factors discussed above is gaining support in humans as well as in animal models. Indeed, elevation of estrogen receptor, GH, IGF-I, and IGF-I receptor during progression suggests a role for these pathways in this process. New agents targeting the GH/IGF-I axis may provide a novel means to block formation and progression of precursor lesions to overt carcinoma. A novel somatostatin analog has recently been shown to prevent mammary development in rats via targeted IGF-I action inhibition at the mammary gland. Similarly, pegvisomant, a GH antagonist, and other IGF-I antagonists such as IGF binding proteins 1 and 5 also block mammary gland development. It is, therefore, possible that inhibition of IGF-I action, or perhaps GH, in the mammary gland may eventually play a role in breast cancer chemoprevention by preventing actions of both estrogen and progesterone, especially in women at extremely high risk for developing breast cancer such as BRCA gene 1 or 2 mutations.
Minireview: GPCR and G Proteins: Drug Efficacy and Activation in Live Cells
Authors: Vilardaga Jean-Pierre , Bünemann Moritz , Feinstein Timothy N. , Lambert Nevin , Nikolaev Viacheslav O. , Engelhardt Stefan , Lohse Martin J. , Hoffmann Carsten 
Published: February 2009

AbstractMany biochemical pathways are driven by G protein-coupled receptors, cell surface proteins that convert the binding of extracellular chemical, sensory, and mechanical stimuli into cellular signals. Their interaction with various ligands triggers receptor activation that typically couples to and activates heterotrimeric G proteins, which in turn control the propagation of secondary messenger molecules (e.g. cAMP) involved in critically important physiological processes (e.g. heart beat). Successful transfer of information from ligand binding events to intracellular signaling cascades involves a dynamic interplay between ligands, receptors, and G proteins. The development of Förster resonance energy transfer and bioluminescence resonance energy transfer-based methods has now permitted the kinetic analysis of initial steps involved in G protein-coupled receptor-mediated signaling in live cells and in systems as diverse as neurotransmitter and hormone signaling. The direct measurement of ligand efficacy at the level of the receptor by Förster resonance energy transfer is also now possible and allows intrinsic efficacies of clinical drugs to be linked with the effect of receptor polymorphisms.
Negative Regulation of TSHα Target Gene by Thyroid Hormone Involves Histone Acetylation and Corepressor Complex Dissociation
Authors: Wang Dongqing , Xia Xianmin , Liu Ying , Oetting Alexis , Walker Robert L. , Zhu Yuelin , Meltzer Paul , Cole Philip A. , Shi Yun-Bo , Yen Paul M. 
Published: February 2009

AbstractCurrently, little is known about histone modifications and molecular mechanisms of negatively regulated transcription. In pituitary cells, thyroid hormone (T3) decreased transcription, and surprisingly increased histone acetylation, of TSHα promoter. This increase was mediated directly by thyroid hormone receptor. Histone acetylation of H3K9 and H3K18 sites, two modifications usually associated with transcriptional activation, occur in negative regulation of TSHα promoter. T3 also caused release of a corepressor complex composed of histone deacetylase 3 (HDAC3), transducin β-like protein 1, and nuclear receptor coprepressor (NCoR)/ silencing mediator for retinoic and thyroid hormone receptor from TSHα promoter in chromatin immunoprecipitation assays. NCoR and HDAC3 overexpression selectively increased ligand-independent basal transcription. Two histone acetyltransferase inhibitors increased overall transcription but did not abrogate negative regulation or NCoR/HDAC3 complex release by T3. Chromatin immunoprecipitation analyses of an endogenous positively regulated target gene showed increased histone acetylation and corepressor complex release with T3 treatment. Finally, microarray analyses suggested there is a subset of negatively regulated genes with increased histone acetylation. These findings demonstrate the critical role of NCoR/HDAC3 complex in negative regulation of TSHα gene expression and show that similar complexes and overlapping epigenetic modifications can participate in both negative and positive transcriptional regulation.
Significance of the cyclic structure and of arginine residues for the antibacterial activity of arenicin-1 and its interaction with phospholipid and lipopolysaccharide model membranes
Authors: Andrä Jörg , Hammer Malte U. , Grötzinger Joachim , Jakovkin Igor , Lindner Buko , Vollmer Ekkehard , Fedders Henning , Leippe Matthias , Gutsmann Thomas 
Published: February 2009

Abstract
Arenicin-1 (Ar-1) is a β-sheeted antimicrobial peptide from the marine lugworm Arenicola marina. To elucidate the significance of its unique 18-residue cyclic structure and of six cationic arginines for its biological activity and its interaction with biomembranes, we synthesized one linear peptide in which the two cysteines were exchanged for serines (C/S-Ar-1) and a cyclic peptide in which all arginines were replaced by lysines (R/K-Ar-1). We addressed antibacterial and hemolytic activities, the impact of the peptides on bacterial morphology, and their binding to, intercalation into, and permeabilization of model membranes composed of phospholipids or lipopolysaccharide (LPS). In accordance with high salt concentration in sea water, the antibacterial activity of Ar-1 was almost insensitive to high NaCl concentrations. In contrast, the linear derivative lost activity under these conditions against polymyxin B-resistant Proteus mirabilis. Ar-1 intercalated into phospholipid and LPS membranes and formed heterogeneous and short-lived lesions. However, when the peptide was present in both membrane leaflets, it formed defined pores. This characteristic was not observed for the linear derivative C/S-Ar-1. Apparently, the disulfide bond provides conforma-tional stability, which has an impact on salt tolerance, prevents fast degradation by trypsin, and is a prerequisite for the formation of structurally defined pores.
Developmental alterations of the prefrontal cerebral cortex in sudden unexplained perinatal and infant deaths
Authors: Lavezzi Anna Maria , Mauri Maria , Mecchia Donatella , Matturri Luigi 
Published: February 2009

Abstract
The aim of this study was to investigate the developmental patterns of the human prefrontal cortex involved in breathing control in a wide cohort of fetal and infant death victims, aged from the 22nd gestational week to 10 months of life, and to evaluate whether morpho-functional disorders are present in this specific cortical area in victims of sudden unexplained death. A further aim was to determine whether prenatal absorption of nicotine could also affect the maturational processes of the prefrontal cortex. A pronounced radial organization of the cerebral wall was evident from the 26th gestational week. By 36 gestational weeks this columnar structure disappeared, coinciding with the formation of a laminar cyto-architecture. The mature cortex, observable from the 4th month of life, was organized horizontally into six laminae. In 33% of the sudden death victims the prefrontal cortex showed morphological alterations with anomalous laminar patterns and delayed neuronal maturation. A significant correlation with prenatal cigarette exposure was found.
Immunologic and infectious consequences of immediate versus delayed umbilical cord clamping in premature infants: A prospective, randomized, controlled study
Authors: Kugelman Amir , Borenstein-Levin Liron , Kessel Aharon , Riskin Arieh , Toubi Elias , Bader David 
Published: February 2009

Abstract

Aim: To evaluate the immunologic and infectious consequences of delayed versus immediate cord clamping in premature infants (<35 weeks) during the neonatal period.

Methods: This was a prospective, masked, randomized, controlled, single-center study. Prior to delivery 35 infants were randomly assigned to immediate cord clamping (ICC) at 5–10 s and 30 infants to delayed cord clamping (DCC), at 30–45 s (14 and 15 infants in each group were <1500 g, respectively).

Results: Neonatal characteristics of the ICC and DCC groups were comparable. There was no significant difference between the ICC and DCC groups in the complement or in the immunoglobulin levels. All were within the normal range for age. All infectious parameters (events of sepsis or “rule-out sepsis”, days of antibiotic therapy, and number of antibiotic courses during hospitalization and infections within the first month of life in cases of earlier discharge) were comparable in both groups. Similar results were found in the subgroup of infants <1500 g. Gender analysis showed only modest differences.

Conclusions: Delayed compared to immediate cord clamping did not affect the immunologic or the infectious status of infants born at <35 weeks during the neonatal period.
Statistical model predicting a short duration to birth in women with preterm labor at 22–35 weeks' gestation: the importance of large vaginal Gram-positive rods
Authors: Usui Rie , Ohkuchi Akihide , Matsubara Shigeki , Suzuki Mitsuaki 
Published: February 2009

Abstract

Aims: To identify risk factors for a short interval to birth in women with preterm labor, and to construct a statistical model to predict birth within seven days from the diagnosis of preterm labor at 22–35 weeks of gestation.

Methods: Vaginal flora was obtained from 126 singleton pregnant women hospitalized for preterm labor at 22–35 weeks' gestation. The amount of vaginal large Gram-positive rods (GPR) was counted in a bright field under ×400 magnification and classified semiquantitively as loss of GPRs, decreased GPRs (<10), and normal flora (10 or more). The effects of vaginal GPRs, cervical dilatation, and previous history of preterm birth on the subsequent occurrence of birth were analyzed using proportional hazards model, and the effects on birth within seven days from the diagnosis of preterm labor were analyzed using multivariate logistic regression.

Results: Fifty-four women (42.9%) delivered preterm. Both loss of GPRs and decreased GPRs were independent risk factors for a short interval from threatened preterm labor to birth, after adjusting the effect of cervical dilatation and past history of preterm birth (hazard ratio 3.4 [95% CI 2.0–5.5] and 2.0 [95% CI 1.1–3.6], respectively). Cervical dilatation of <4.0 cm and 2.0–3.9 cm, and past history of preterm birth were also independent risk factors for a short interval to birth. Loss of GPRs and decreased GPRs, and cervical dilatation of <4.0 cm and 2.0–3.9 cm were independently associated with birth within seven days from the diagnosis of preterm labor (OR 26 [95% CI 5.3–130], 11 [1.9–69], 76 [8.0–720], and 6.4 [1.5–27], respectively).

Conclusions: Loss of GPRs and decreased GPRs may be independently important for developing birth in women with preterm labor.
Evaluation of normal neurological development of human fetuses from 21 to 30 weeks' gestation through fetal auditory evoked response
Authors: Luz Sérgio Hecker , Vasconcellos Fabiano Candal , Kreling Tatiana , Pacheco Fernanda Silva , Fagundes Chaves Márcia Lorena 
Published: February 2009

Abstract

Objectives: To evaluate the neurological maturation of fetuses between 21 and 30 weeks' gestation by the auditory evoked response.

Methods: The auditory evoked responses of 25 normal singleton fetuses were observed once a week from 21 to 30 weeks' gestation. The stimulus consisted of five pulses of sinusoidal waves, for 2 s, at 1500 cycles/s, with a sound pressure of 125 dB.

Results: Fetal auditory evoked response increased with neurological maturation, presenting two main points of positive discontinuity. The two points in the heart response were detected between the 24th/25th and the 27th/28th week. From the 27th week on, fetal motor response (FMR) was always present. Initial fetal heart response presented a fluctuation pattern between the 21st and the 30th week, with a tendency to increase as gestational age advanced. Fetal heart response also increased with gestational age. Late response (LR) fluctuated until the 29th week, and was always present after that period.

Conclusions: The maturation of the fetal nervous system is clearly demonstrated by changes in the auditory evoked responses in different gestational ages, and presents some discontinuity points.
Access to level III perinatal care for pregnancies of very short duration (<32 weeks)
Authors: Di Napoli Anteo , Di Lallo Domenico , Franco Francesco , Scapillati Maria Eleonora , Zocchetti Carlo , Agostino Rocco , Orzalesi Marcello 
Published: February 2009

Abstract

Aims: To evaluate to which extent pregnancies of very short duration (<32 weeks' gestation) are concentrated in level III centers.

Methods: Area-based study in the 57 maternity units of the Lazio Region (Italy), years 2003–2004, including: 1012 live births (gestational age 22–31 weeks), 261 fetal losses (22–31 weeks) and 209 induced abortions (22–25 weeks). Variables associated with access to a level III unit were evaluated through multivariable logistic regression models.

Results: 83.7% of all pregnancies <32 weeks (88.8% of live births, 71.6% of fetal losses and 75.1% of induced abortions) were admitted to a level III perinatal center; 23.4% of live newborns, delivered in a level III hospital, were subsequently transferred to a same level facility. The probability that a fetal loss was not treated in a level III perinatal unit was higher for women without pregnancy complication, with lower education level, and living outside the metropolitan area.

Conclusions: Regionalization of perinatal care in Lazio is not satisfactory. Concentration of high-risk deliveries in level III centers is good, but in utero transfer is insufficient. This study can help to define the effectiveness of different organizational systems on access to locally available perinatal facilities and to optimize general organizational patterns of perinatal care.
Translational and Rotational Accelerations Generated During Reconstructed Ice Hockey Impacts on a Hybrid III Head Form
Authors: Coulson N. R. , Foreman S. G. , Hoshizaki T. B. 
Published: February 2009

Abstract
In this study, the relationship between flagrant impacts to the head and peak translational and rotational accelerations in reconstructed ice hockey impacts was examined. A Hybrid III head-neck complex attached to a sliding table and equipped with nine accelerometers was fitted with an ice hockey helmet and impacted under various striking conditions through the head form’s center of mass. Eight right-hand-dominant male ice hockey players carried out three maximal impacts for each of the striking techniques, and peak translational and rotational accelerations were measured. It was found that the highest mean translational and rotational accelerations were generated during the slashing trials to a static head form (138 g and 14,100 rad/s2, respectively), while the lowest mean translational and rotational accelerations were produced in the static crosschecking (26.5 g) and moving crosschecking trials (2,260 rad/s2), respectively. The reconstruction of illegal impacts reflecting flagrant fouls in ice hockey can generate peak translational and rotational accelerations great enough to cause concussive injuries. Accordingly, these types of injurious infractions must be prevented.
Modeling arsenic desorption from herbicide-contaminated soils
Authors: Qi Yongqiang , Donahoe Rona J. 
Published: February 2009

Abstract
The application of arsenical herbicides has created legacy environmental problems by contaminating soil in some agricultural areas and at various industrial sites. Numerous previous studies have suggested that the adsorption of arsenic by common soil components is largely controlled by kinetic factors. Four arsenic-contaminated soil samples collected from industrial sites were characterized and subjected to sequential leaching using a synthetic acid rain solution in order to study the release of arsenic. A dual-site numerical sorption-desorption model was constructed that describes arsenic desorption from these soils in terms of two different release mechanisms: Release from type I (equilibrium) and type II (kinetic) sorption sites. Arsenic held on both type I and II sorption sites is accessible through extensive acid rain leaching. Arsenic desorption from these sites follows a linear Kd model; the manner of approaching the Kd model, however, differs. Arsenic desorption from type I sites reached equilibrium with the aqueous phase under the physical environment provided by the experiment (shaking for 24 h at 25°C), while desorption from type II sites followed a first-order kinetic pattern when approaching equilibrium. During synthetic acid rain sequential leaching of the soils, type I sites released their sorbed arsenic rapidly and subsequent desorption was dominated by the kinetic release of arsenic from type II sites. This shift in desorption mechanism dominance generated data corresponding to two intersecting straight lines in the n-logC dimension for all four soils. The dual-site desorption model was solved analytically and proven to be successful in simulating sorption processes where two different mechanisms are simultaneously controlling the aqueous concentration of a trace element.
The Economic Impact of Exposure to Secondhand Smoke in Minnesota
Authors: Waters Hugh R. , Foldes Steven S. , Alesci Nina L. , Samet Jonathan 
Published: February 2009

Objectives. Using the risk categories established by the 2006 US surgeon general's report, we estimated medical treatment costs related to exposure to secondhand tobacco smoke (SHS) in the state of Minnesota. Methods. We estimated the prevalence and costs of treated medical conditions related to SHS exposure in 2003 with data from Blue Cross and Blue Shield (Minnesota's largest insurer), the Current Population Survey, and population attributable risk estimates for these conditions reported in the scientific literature. We adjusted treatment costs to the state level by health insurance category by using the Medical Expenditure Panel Survey. Results. The total annual cost of treatment in Minnesota for conditions for which the 2006 surgeon general's report found sufficient evidence to conclude a causal link with exposure to SHS was $228.7 million in 2008 dollars—equivalent to $44.58 per Minnesota resident. Sensitivity analyses showed a range from $152.1 million to $330.0 million. Conclusions. The results present a strong rationale for regulating smoking in public places and were used to support the passage of Minnesota's Freedom to Breathe Act of 2007.
Mexican Americans and Frailty: Findings From the Hispanic Established Populations Epidemiologic Studies of the Elderly
Authors: Ottenbacher Kenneth J. , Graham James E. , Al Snih Soham , Raji Mukaila , Samper-Ternent Rafael , Ostir Glenn V. , Markides Kyriakos S. 
Published: February 2009

Objectives. We examined the prevalence of frailty among Mexican American older adults and explored the correlates associated with becoming frail to determine their affect on disability and morbidity in this population. Methods. We studied the trajectory of frailty over 10 years in 2049 Mexican Americans participating in the Hispanic Established Populations Epidemiologic Studies of the Elderly. We constructed a frailty index based on weight loss, exhaustion, grip strength, walking speed, and physical activity and collected data on sociodemographic and health status, comorbidities, and functional measures of performance. Results. The sample was 58% female, with a mean age of 74.43 years (SD = 6.04) at baseline. Fifty-five percent of participants at baseline and 75% of the surviving sample at follow-up (n = 777) were classified as prefrail or frail. Of persons identified as frail at baseline, 84% died by the end of follow-up. Baseline age, diabetes, arthritis, smoking status, body mass index, cognition, negative affect, and number of comorbid conditions were predictors of frailty at follow-up (R2 = 0.29; P < .05). Conclusions. Further research into ways to reduce the number of Mexican American older adults who become frail and disabled and therefore lose their independence is needed. Future studies should continue to examine the trajectory of frailty as a dynamic process that includes psychosocial and cognitive components.
Assessing Glycemic Control in Maintenance Hemodialysis Patients With Type 2 Diabetes
Authors: Kazempour-Ardebili Sara , Lecamwasam Varunika L. , Dassanyake Thushara , Frankel Andrew H. , Tam Frederick W.K. , Dornhorst Anne , Frost Gary , Turner Jeremy J.O. 
Published: February 2009

OBJECTIVE
Optimizing glycemic control in diabetic patients undergoing maintenance hemodialysis requires accurate assessment. We hypothesize that 1) 48-h continuous glucose monitoring (CGM) provides additional, clinically relevant, information to that provided by the A1C measurement and 2) glycemic profiles differ significantly between day on and day off dialysis.

RESEARCH DESIGN AND METHODS
With the use of GlucoDay S, 48-h CGM was performed in 19 type 2 diabetic subjects undergoing hemodialysis to capture consecutive 24-h periods on and off dialysis. Energy intake was calculated using food diaries. A1C was assayed by a high-performance liquid chromatography method.

RESULTS
CGM data were available for 17 subjects (13 male) with a mean (range) age of 61.5 years (42–79 years) and diabetes duration of 18.8 years (4–30 years). The 24-h CGM area under the glucose curve and 24-h mean glucose values were significantly higher during the day off dialysis than on dialysis (5,932.1 ± 2,673.6 vs. 4,694 ± 1,988.0 mmol · 3 min−1 · l−1, P = 0.022, and 12.6 ± 5.6 vs. 9.8 ± 3.8 mmol/l, P = 0.013, respectively), independent of energy intake. Asymptomatic hypoglycemia occurred in 4 subjects, 3 within 24 h of dialysis, and the glucose nadir in 14 subjects occurred within 24 h of dialysis.

CONCLUSIONS
Glucose values are significantly lower on dialysis days than on nondialysis days despite similar energy intake. The risk of asymptomatic hypoglycemia was highest within 24 h of dialysis. Physicians caring for patients undergoing hemodialysis need to be aware of this phenomenon and consider enhanced glycemic monitoring after a hemodialysis session. CGM provides glycemic information in addition to A1C, which is potentially relevant to clinical management.