Association of passive and active smoking with pre-diabetes risk in a predominantly Hispanic population

Smoking is the leading cause of avoidable death and is associated with type 2 diabetes (T2D) risk. Previous studies on the impact of passive smoking have not been applied to a Hispanic-majority population. We investigated the association between active smoking, exposure to environmental tobacco smoke (ETS), and pre-diabetes risk in a New Mexico population. We hypothesized that pre-diabetes risk increases with increasing smoking status after adjustment for important covariates. We screened 219 adults from an ongoing study who were categorized according to their smoking status (never smoker, current smoker, previous smoker) and their exposure to ETS (exposed or unexposed). Glucose homeostasis status was assigned using A1c: no diabetes (A1c <5.7%), pre-diabetes (A1c 5.7-6.4%), and T2D (A1c >6.4%). Among 160 patients with complete data, 51.6% had no diabetes and 48.4% had pre-diabetes. The mean age was 44.8±13.5 years. The study population was predominantly female (64.4%), and the ethnic composition was 44.4% Hispanic, 39.4% non-Hispanic White (NHW), 10.6% American Indian, 2.5% African-American, and 3.1% other. Using a logistic model with 2-way interactions, all predicted probabilities for being at risk for pre-diabetes were significant at the 0.001 level for smoking status and ETS exposure after adjusting for age, sex, ethnicity, family history of diabetes, alcohol consumption, BMI, and blood pressure. Active or passive smoking is independently associated with pre-diabetes risk.

Abstract P4-03-09: Malignant hyperechoic lesions in breast ultrasound - Frequency and characteristics

PURPOSE

Challenge current axiom regarding hyperechogenic lesions in breast US categorized as mainly benign lesions. 2) Present frequency of malignant hyperechoic lesions, describe their sonographic and histological characteristics.

METHOD AND MATERIALS

IRB approved retrospective review of 2369 consecutive US-guided Core biopsies between 2006 and 2014. Lesions were considered hyperechogenic when more than 90% of its volume had higher echogenicity than surrounding subcutaneous tissue. Variables assessed were: age, size, histology, mass or non-mass, margins, echogenicity, acoustic effect, orientation, location, presence of a hypoechoic center, vascularization and BI-RADS category. Qualitative variables were described by percentage distribution, mean and SD.

RESULTS

Thirty one (1,3%) lesions biopsied were hyperechoic: only 17 (54.8%) were benign. We found 14 patients (range, 39-81 years, mean 57,5 years) with hyperechoic cancers, accounting for 1,77% of all cancers. 12 (85,7%) were ductal and 2 (14,3%) lobular histology (mean 17,5 mm range 8-40mm). All of them exhibited a small central hypoechoic area and were partially or completely surrounded by fatty tissue. Shape, margins, orientation and vascular architecture were highly suggestive of malignancy at US, mammography and in MRI (BI-RADS 4B and 5). On histology, all lesions were surrounded by fatty tissue, with a low–cell count collagenous center with a higher peripheral cellularity, mixing and interweaving with adipose tissue.

CONCLUSION

Hyperechogenic breast cancers are rare (1.77%), and we challenge the current concept of high rate of benignity with a 45,2% of chances for malignancy. We propose that hyperechogenicity is given by interweaving bundles with adipose tissue, which provide higher amount of acoustic reflective surfaces, thus explaining its sonographic pattern.

CLINICAL RELEVANCE/APPLICATION

Hyperechogenic breast lesions should not be considered as always benign. Malignancy thresholds should not be influenced by this sonographic characteristic.

We propose histopathological explanation of this sonographic pattern.

Citation Format: Camacho J, Horvath E, Pizzolon MF, Pinochet MA, Gallegos M, Galleguillos C, Uchida M, Cadiz F, Silva C. Malignant hyperechoic lesions in breast ultrasound - Frequency and characteristics. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P4-03-09.

[Case report and literature review: elbow fracture dislocation in children]

Elbow dislocation in children is a very infrequent traumatic event which was first described by Stimson in 1900 and then by Tachdjian in 1990. Its estimated incidence ranges from 3% to 6% of all elbow injuries, peaking at 13-14 years. Elbow trauma is classified considering the direction in which the proximal radioulnar joint shifts with respect to the humerus, into posterior and anterior dislocation. The former is the most frequent and accounts for 95% of cases. Elbow fracture dislocation is an even rarer event. The incidence rate of avulsion fracture of the medial epicondyle is 25-36%, of the lateral condyle 4%, of the olecranon 1.7%, of the radial head 8%, of the coronoid process 3.5%, and others, 3.5%. At present there is no consensus in the literature on how to treat this type of lesions, particularly because some authors advocate nonsurgical management, while others propose surgical management as the definitive treatment. What is clear, however, is that a late diagnosis or untimely treatment may affect the child's growth and lead to serious complications. The purpose of this study is to share our experience and good results with the surgical management of these infrequent cases.

Determinants of manganese levels in house dust samples from the CHAMACOS cohort

INTRODUCTION

Manganese (Mn) is an essential nutrient, but at high exposure levels Mn is a neurotoxicant. The fungicides maneb and mancozeb are approximately 21% Mn by weight and more than 150,000 kg are applied each year to crops in the Salinas Valley, California. It is not clear, however, whether agricultural use of these fungicides increases Mn levels in homes.

MATERIALS AND METHODS

We collected house dust samples from 378 residences enrolled in the Center for the Health Assessment of Mothers and Children of Salinas (CHAMACOS) study with a second sample collected approximately nine months later from 90 of the residences. House dust samples were analyzed for Mn using inductively coupled plasma optical emission spectroscopy. Information from interviews, home inspections, and pesticide use reports was used to identify potential predictors of Mn dust concentrations and loadings.

RESULTS

Mn was detectable in all dust samples. The median Mn concentration was 171 μg/g and median Mn loading was 1,910 μg/m(2) at first visit. In multivariable models, Mn dust concentrations and loadings increased with the number of farmworkers in the home and the amount of agricultural Mn fungicides applied within three kilometers of the residence during the month prior to dust sample collection. Dust concentrations of Mn and other metals (lead, cadmium and chromium) were higher in residences located in the southern Salinas Valley compared those located in other areas of the Salinas Valley. Dust loadings of Mn and other metals were also higher in residences located on Antioch Loam soil than other soil types, and in homes with poor or average housekeeping practices.

CONCLUSIONS

Agricultural use of Mn containing fungicides was associated with Mn dust concentrations and loadings in nearby residences and farmworker homes. Housekeeping practices and soil type at residence were also important factors related to dust metal concentrations and loadings.

[Elbow dislocation and lateral epicondyle fracture in a five year-old girl. Case report]

Traumatic elbow dislocation in the pediatric population is a particularly unusual injury. It was first described by Stimson in 1900 and almost 100 years later revisited by Tachdjian in 1990. Three percent of cases are associated with lateral epicondyle fracture, so this is an infrequent injury that has been described in only a few papers as case reports. The mechanism of injury is not clearly known, nor is the best type of treatment or its complications. We report herein the case of a five year-old girl with fracture dislocation of the lateral epicondyle who was managed with closed reduction and percutaneous fixation with Kirschner nails, with good functional results.

KCNH1 potassium channels are expressed in cervical cytologies from pregnant patients and are regulated by progesterone

Potassium voltage-gated channel, subfamily H (eag-related), member 1 (KCNH1) potassium channels are potential tumour markers and cancer therapeutic targets and are up-regulated by oestrogens and human papilloma virus (HPV) oncogenes. However, the role of KCNH1 in normal tissues is poorly understood, and its expression in pregnancy is unknown. We wondered whether KCNH1 channels are expressed in cervical cells from pregnant patients and whether progesterone (P4) regulates KCNH1. The association with HPV was also investigated. KCNH1 protein expression was studied by immunocytochemistry in liquid-based cervical cytologies; 93 samples were obtained from pregnant patients at different trimesters, and 15 samples were obtained from non-pregnant women (controls). The presence ofHPVwas studied by PCR with direct sequencing and nested multiplex PCR. HeLa cervical cancer cells were transfected with human progesterone receptor-B (PR-B) and treated with P4.KCNH1mRNA expression in these cultures was studied by real-time PCR. KCNH1 protein was detected in 100% of the pregnancy samples and in 26% of the controls. We found 18 pregnant patients infected with HPV and detected 14 types ofHPV. There was no association between the percentage of cells expressing KCNH1 and either the presence or type of HPV. P4induced KCNH1 mRNA and protein expression in cells transfected with human PR-B. No regulation of KCNH1 by P4was observed in non-transfected cells. We show for the first time the expression of an ion channel during human pregnancy at different trimesters and KCNH1 regulation by P4in human cells. These data raise a new research field for KCNH1 channels in human tissues.

Scarcity may promote cooperation in populations of simple agents

In the study of the evolution of cooperation, resource limitations are usually assumed just to provide a finite population size. Recently, however, it has been pointed out that resource limitation may also generate dynamical payoffs able to modify the original structure of the games. Here we study analytically a phase transition from a homogeneous population of defectors when resources are abundant to the survival of unconditional cooperators when resources reduce below a threshold. To this end, we introduce a model of simple agents, with no memory or ability of recognition, interacting in well-mixed populations. The result might shed light on the role played by resource constraints on the origin of multicellularity.

Abstract P6-04-29: Vitamin D induces expression of estrogen receptor and restores endocrine therapy response in estrogen receptor-negative breast cancer

Background: Approximately 30% of all breast tumors do not express estrogen receptor (ER) and patients with these tumors present poor prognosis and respond poorly to hormone therapy. Calcitriol through its vitamin D receptor (VDR) exerts antiproliferative, apoptotic and pro-differentiating effects in cancer. Calcitriols effects upon ER expression in breast cancer cells is controversial. Therefore, in order to clarify this issue, the aim of the present study was to determine if calcitriol induces ERα expression in ERα-negative breast cancer cells and could restore antiestrogen responses. The evaluation of calcitriol effects was performed in terms of proliferation and regulation of the following genes: Cyclin D1, involved in cell cycle, and Ether-à-go-go 1 (Eag1), related to cell proliferation and tumor progression.

Methods: Cultured cells derived from ERα-negative breast tumors and an established ERα-negative breast cancer cell line (SUM 229) were used in this study. These cells were treated with calcitriol and reverse transcription-PCR or western blotting analyses were performed to assess ERα expression. Growth assays with XTT were used to evaluate the antiproliferative response to the antiestrogens fulvestran and tamoxifen. Gene expression analysis for Cyclin D1 and Eag1 was evaluated by real time PCR in cells treated simultaneously with calcitriol plus estradiol or fulvestran.

Results: The treatment with calcitriol in ER-negative breast cancer cells resulted in the induction of ERα. This effect was specifically mediated through the vitamin D3 receptor (VDR), since the VDR antagonist TEI-9647 effectively inhibited the ability of calcitriol to stimulate ERα gene expression. Consequently, the induction of ERα by calcitriol restores the response to antiestrogens in breast cancer cells by inhibiting cell proliferation. Co-treatment of calcitriol and antiestrogens down-regulated Cyclin D1 and Eag1 gene expression.

Conclusion: Calcitriol induced the expression of ERα and restored antiestrogenic responses in ERα-negative breast cancer cells. Moreover, fulvestran down regulated mRNA expression of Cyclin D1 and Eag1 when ERα-negative cells were pre-treated with calcitriol. These results suggest that the combined treatment with calcitriol and antiestrogens could be a new therapeutic strategy for ERα-negative breast cancer patients.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P6-04-29.

Analytical models for well-mixed populations of cooperators and defectors under limiting resources

In the study of the evolution of cooperation, resource limitations are usually assumed just to provide a finite population size. Recently, however, agent-based models have pointed out that resource limitation may modify the original structure of the interactions and allow for the survival of unconditional cooperators in well-mixed populations. Here, we present analytical simplified versions of two types of agent-based models recently published: one in which the limiting resource constrains the ability of reproduction of individuals but not their survival, and a second one where the limiting resource is necessary for both reproduction and survival. One finds that the analytical models display, with a few differences, the same qualitative behavior of the more complex agent-based models. In addition, the analytical models allow us to expand the study and identify the dimensionless parameters governing the final fate of the system, such as coexistence of cooperators and defectors, or dominance of defectors or of cooperators. We provide a detailed analysis of the occurring phase transitions as these parameters are varied.

Coexistence of cooperators and defectors in well mixed populations mediated by limiting resources

Traditionally, resource limitation in evolutionary game theory is assumed just to impose a constant population size. Here we show that resource limitations may generate dynamical payoffs able to alter an original prisoner's dilemma, and to allow for the stable coexistence between unconditional cooperators and defectors in well-mixed populations. This is a consequence of a self-organizing process that turns the interaction payoff matrix into evolutionary neutral, and represents a resource-based control mechanism preventing the spread of defectors. To our knowledge, this is the first example of coexistence in well-mixed populations with a game structure different from a snowdrift game.

Abstract C13: Human Eag1 potassium channel expression in lung cancer biopsies

Introduction. Lung cancer is the most common malignancy in the world including Mexico [1, 2]. Smoking is the main risk factor for the development of different types of lung cancer, about 70–80% of lung cancer cases are associated with smoking and approximately 50% of new cancer cases are diagnosed in ex-smokers. Current therapies rarely cure the disease, and the high relapse rate with the delay in diagnosis results in a poor prognosis and overall survival rates of 10% [1]. Several ion channels are over-expressed in cancer including Kv1.3, K2p9.1, Kv10.1 (Eag1) and Kv11.1 (HERG) channels. These channels are expressed in different cell types and tumor tissues and have been shown to increase cell proliferation. Eag1 is expressed aberrantly with a high frequency (75%) in tumor cells of different histological origins including sarcomas, carcinomas of the breast, colon, and cervix. Eag1 inhibition by either astemizole, imipramine, or Eag1 specific monoclonal antibodies reduces tumor cell proliferation in vitro and in vivo [3, 4, 5]. Eag1 channels are over-expressed in lung cancer [6]. However, a detailed study of Eag1 expression in the different types of lung cancer is missing.

Materials and Methods: Lung biopsies: 44 Lung biopsies were obtained from patients attending the Instituto Nacional de Enfermedades Respiratorias (National Institute for Respiratory Diseases) in Mexico City following local ethical considerations. Patients had no prior treatment (chemotherapy or radiotherapy). 37 biopsies were classified as lung cancer samples and included adenocarcinoma, epidermoid, small cell, adenosquamous and neuroendocrine tumors. 5 samples were diagnosed as inflammatory disease and 2 were form patients with thyroid carcinoma. RNA extraction was performed with TRIzol (Life Technologies, Invitrogene) according to the manufacturer's recommendation. cDNA was synthesized by reverse transcription under the manufacturer's recommendations (New England BioLabs). Eag1 gene expression was assessed by real-time PCR under the manufacturer's recommendations (Fermentas SYBR Green/ROX qPCR Master Mix). Eag1 expression in lung biopsies was compared to Eag1 basal expression in fibroblasts from normal lung (WI-38) which was given the value of 1.

Results: Eag1 expression was found in 81% of the cancer biopsies while 8% of the samples did not showed changes and in 10% of the biopsies Eag1 was found to be under-expressed. Interestingly, Eag1 was over-expressed in 80% of the samples from chronic inflammation while no changes were observed in the samples from thyroid carcinoma.

Conclusions: Our results suggest Eag1 as a tumor marker for different types of lung cancer and as a potential early marker of the disease.

References:

1. MacKinnon C A et al. British Medical Bulletin. 95: 47–61. 2010.

2. Molina-Alavez A et al. Gaceta mexicana de oncología. 7(5): 169–173. 2008.

3. Pardo A L et al. The journal of membrane biology. 205: 115–124. 2005.

4. Blackiston J D et al. Cell cycle. 8(21): 3527–3536. 2009.

5. Camacho J. Cancer letters. 233: 1–9. 2006.

6. Hemmerlein et al. Molecular cancer. 5(41): 1–13. 2006.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2011 Nov 12-16; San Francisco, CA. Philadelphia (PA): AACR; Mol Cancer Ther 2011;10(11 Suppl):Abstract nr C13.

Risk of hyperamylasemia and acute pancreatitis after double-balloon enteroscopy: a prospective study

BACKGROUND AND STUDY AIMS

There have been reports, mainly retrospective, of pancreatitis and hyperamylasemia after anterograde double-balloon enteroscopy (DBE). Our aim was to report the incidence of pancreatitis and hyperamylasemia after DBE and investigate possible risk factors associated with its occurrence.

PATIENTS AND METHODS

In this single-center prospective cohort study, serum samples were taken for amylase and lipase before and 3 hours after anterograde DBE in consecutive patients. Multiple variables were recorded, including total procedure time, insertion depth, and number of passes. Patients were evaluated to 24 hours later for signs of pancreatitis. The main outcome measures were the occurrence of hyperamylasemia and pancreatitis.

RESULTS

92 patients were included in the analysis (58 women, 34 men; mean age 54 years, range 18-89). The mean total procedure time was 62 minutes (range 30-120). The mean post-procedure amylase and lipase levels were significantly higher in comparison with the baseline levels (165 U/L vs. 69 U/L and 144 U/L vs. 28 U/L respectively, P<.05); 36 patients (39%) showed hyperamylasemia after the procedure and three patients developed acute mild pancreatitis. Hyperamylasemia was associated more frequently with procedure duration greater than 60 minutes ( P<.001) and insertion depth greater than 25 cm ( P<.013).

CONCLUSIONS

The incidence of hyperamylasemia after anterograde DBE is common and particularly associated with longer procedure time and insertion depth. The cumulative incidence of pancreatitis was 3%. We recommend the avoidance of both unnecessarily lengthy procedures and deep insertion distances in patients who undergo anterograde DBE.

Simple analytical model for the magnetophoretic separation of superparamagnetic dispersions in a uniform magnetic gradient

Magnetophoresis--the motion of magnetic particles under applied magnetic gradient--is a process of great interest in novel applications of magnetic nanoparticles and colloids. In general, there are two main different types of magnetophoresis processes: cooperative magnetophoresis (a fast process enhanced by particle-particle interactions) and noncooperative magnetophoresis (driven by the motion of individual particles in magnetic fields). In the case of noncooperative magnetophoresis, we have obtained a simple analytical solution which allows the prediction of the magnetophoresis kinetics from particle characterization data (size and magnetization). Our comparison with new experimental results shows good quantitative agreement. In addition, we show the existence of a universal curve onto which all experimental results should collapse after proper rescaling. The range of applicability of the analytical solution is discussed in light of the predictions of a magnetic aggregation model [Soft Matter 7, 2336 (2011)].

Electronic structure of superconducting KC8 and nonsuperconducting LiC6 graphite intercalation compounds: evidence for a graphene-sheet-driven superconducting state

We have performed photoemission studies of the electronic structure in LiC(6) and KC(8), a nonsuperconducting and a superconducting graphite intercalation compound, respectively. We have found that the charge transfer from the intercalant layers to graphene layers is larger in KC(8) than in LiC(6), opposite of what might be expected from their chemical composition. We have also measured the strength of the electron-phonon interaction on the graphene-derived Fermi surface to carbon derived phonons in both materials and found that it follows a universal trend where the coupling strength and superconductivity monotonically increase with the filling of graphene π(*) states. This correlation suggests that both graphene-derived electrons and graphene-derived phonons are crucial for superconductivity in graphite intercalation compounds.

Development of a multimodal monitoring platform for medical research

A low cost multimodal monitoring and signal processing platform is presented. A modular and flexible system was developed, aimed to continuous acquisition of several biological variables at patient bed-head and further processing with application specific algorithms. System hardware is made of a six-channel isolation and signal conditioning front-end along with a high resolution analog-to-digital converter board connected to a standard laptop. Whole system hardware is compact and light weight, which ensures portability and ease of use at intensive care units. System software is divided in three modules: Acquisition, Signal Processing and Patients Data Management. The first one allows configuring each acquisition channel parameters, depending on the biological variable connected to it, and to store up to several hours of continuous data. Signal processing module implements novel algorithms for research purposes like dynamic cerebral autoregulation, optimal perfusion pressure, critical closing pressure or pulsatility index. It is flexible enough to easily add new processing algorithms, export data to different formats and create graphical reports. Patients data management module organizes acquired records, which allows selecting cases for new studies based on different criteria like monitored variables or pathological information. In this work, whole system architecture is described and algorithms included into the cerebral hemodynamics toolbox are presented along with experimental results.

113 EFFECT OF SOME FACTORS ON CONCEPTION RATE IN ALPACAS UNDER PERUVIAN HIGHLAND CONDITION

Alpacas are a domestic species of South American camelids with a great importance to highland people because of their high-quality fibre production. However, their reproductive performance has been reported to be poor, with a birth rate of 50% under the Andean community’s conditions. Two experiments were designed to evaluate the effect of some factors on the pregnancy rate of alpacas at first service in lactating, 3- to 8-years old, without parity problems. The objective of the first experiment (n = 85) was to evaluate the effect of age (G1: 3, G2: 4 to 5, G3: ≥ 6 years old); mating time (G1: 15 min, G2: 16–24 min, G3: ≥ 25 min), and interval from parturition to mating (G1: 20 days, G2: ≥ 20 days) on first service conception rate. A second experiment (n = 174) evaluated the effect of month of calving (January, February, or March) on conception rate in females with a postpartum interval ≥20 days. Animals were mated with male of good fertility after a receptivity test and confirmation of presence of a dominant follicle ≥7 mm by ultrasonography. Pregnancy was determined by ultrasonography 25 days after mating. Proportional data were compared by Fisher’s exact test. In the first experiment, conception rates were 57.9, 66.7, and 47.2% in females of G1, G2, and G3, respectively (P ≤ 0.05); 50.0, 54.5, and 59.0% in females with mating time of 15, 16–24, or ≥ 25 min of mating; 48.0 and 59.4% in those with a postpartum interval <20 days and ≥20 days (P ≤ 0.05). In the second experiment, conception rates were 58.3, 70.7, and 82.1% in alpacas calving in January, February, and March, respectively (P ≤ 0.05). The results suggest that age of female, postpartum interval, and month of calving are factors that affect conception rates in alpacas. Therefore, a reproductive management system that includes these factors would improve the pregnancy rate in alpacas under highland Peruvian conditions. Consejo Superior de Investigacion – UNMSM.

New ultrasound imaging techniques with phase coherence processing

This work addresses three key subjects to the image quality with phased arrays: timing accuracy, beamforming strategy and post-processing for increased resolution and suppression of grating and side lobes. Timing accuracy is achieved by defining a modular and scalable architecture which guarantees low timing errors, whatever is the system size. The proposed beamforming methodology follows the progressive focusing correction technique, which keeps low focusing errors, provides a high information density and has a simple implementation for real-time imaging in modular architectures. Then, phase coherence imaging is defined to suppress grating and sidelobe indications, simultaneously increasing the lateral resolution.

Anisotropic electron-phonon coupling and dynamical nesting on the graphene sheets in superconducting CaC6 using angle-resolved photoemission spectroscopy

We present the first angle-resolved photoemission studies of electronic structure in CaC6, a superconducting graphite intercalation compound with T_{c}=11.6 K. We find that, contrary to theoretical models, the electron-phonon coupling on the graphene-derived Fermi sheets with high-frequency graphene-derived phonons is surprisingly strong and anisotropic. The shape of the Fermi surface is found to favor a dynamical intervalley nesting via exchange of high-frequency phonons. Our results suggest that graphene sheets play a crucial role in superconductivity in graphite intercalation compounds.

Protection circuits for ultrasound applications

A simple input protection circuit for ultrasound pulse-echo applications is described. Its performance is analyzed with regard to other widely used arrangements. Besides the primary function of showing high impedance during the transducer excitation time and a low impedance path to the amplifier in reception, issues of harmonic distortion, insertion losses, bandwidth, power dissipation, transient response, and noise are addressed. It is shown that the proposed circuit has many advantages, operating without any control signals or bias voltages. It is small and can be considered a good general-purpose protection circuit alternative.

Quantitative analysis of the local structure of food webs

We analyze the local structure of model and empirical food webs through the statistics of three-node subgraphs. We study analytically and numerically the number of appearances of each subgraph for a simple model of food web topology, the so-called generalized cascade model, and compare them with 17 empirical community food webs from a variety of environments, including aquatic, estuarine, and terrestrial ecosystems. We obtain analytical expressions for the probability of appearances of each subgraph in the model, and also for randomizations of the model that preserve species' numbers of prey and number of predators; their difference allows us to quantify which subgraphs are over- or under-represented in both the model and the empirical food webs. We find agreement between the model predictions and the empirical results. These results indicate that simple models such as the generalized cascade can provide a good description not only of the global topology of food webs, as recently shown, but also of its local structure.

Quantitative analysis of organ tissue damage after septic shock

The objective of this study was to quantify end-organ damage caused by bacteremic sepsis. Twelve adult swine were divided into two groups. The anesthesia control group (n = 6) received general anesthesia for 4 hours. The septic shock group (n = 6) received an infusion of Aeromonas hydrophila under general anesthesia for 4 hours. Swine were sacrificed at the end of the 4-hour procedure. Tissues from lungs, kidneys, livers, and hearts were stained with hematoxylin and eosin. Images of tissues were studied with digital image analysis. In lungs, cytoplasmic area (CA), nuclear area (NA), intra-alveolar hemorrhage (IAH), total airspace (TAS), and alveolar septum thickness (ST) were measured. Nuclear and cytoplasmic intensities (NI and CI) were measured in integrated optical density units (IOD). In kidneys, livers, and hearts, CA, CI, NA, and NI were measured similarly. Sinusoidal blood in the liver and vacuolization (VAC) in the kidney were also measured. In septic lungs, CI, NA, NI, ST, IAH, TAS, and ratios of NA/CA, NI/CI, and IAH/TAS were significantly increased compared with the control (P < 0.02). In septic kidneys, CI, NA, VAC, NA/CA, and NI/CI were significantly increased (P < 0.0005). In livers, CA, CI, and NI/CI were significantly increased (P < 0.005). In hearts, the ratios of NA/CA and NI/CI were statistically significant. End organs from septic swine, with exception of the heart, showed significantly higher levels of cellular damage. Digital image analysis provides an objective, precise, and accurate method of quantifying image characteristics. Automating these tasks is a high priority in the research and clinical community in providing a reproducible method for longitudinal analysis of various biological studies.

Quantitative Analysis of Organ Tissue Damage after Septic Shock

The objective of this study was to quantify end-organ damage caused by bacteremic sepsis. Twelve adult swine were divided into two groups. The anesthesia control group (n = 6) received general anesthesia for 4 hours. The septic shock group (n = 6) received an infusion of Aeromonas hydrophila under general anesthesia for 4 hours. Swine were sacrificed at the end of the 4-hour procedure. Tissues from lungs, kidneys, livers, and hearts were stained with hematoxylin and eosin. Images of tissues were studied with digital image analysis. In lungs, cytoplasmic area (CA), nuclear area (NA), intra-alveolar hemorrhage (IAH), total airspace (TAS), and alveolar septum thickness (ST) were measured. Nuclear and cytoplasmic intensities (NI and CI) were measured in integrated optical density units (IOD). In kidneys, livers, and hearts, CA, CI, NA, and NI were measured similarly. Sinusoidal blood in the liver and vacuolization (VAC) in the kidney were also measured. In septic lungs, CI, NA, NI, ST, IAH, TAS, and ratios of NA/CA, NI/CI, and IAH/TAS were significantly increased compared with the control ( P < 0.02). In septic kidneys, CI, NA, VAC, NA/CA, and NI/CI were significantly increased ( P < 0.0005). In livers, CA, CI, and NI/CI were significantly increased ( P < 0.005). In hearts, the ratios of NA/CA and NI/CI were statistically significant. End organs from septic swine, with exception of the heart, showed significantly higher levels of cellular damage. Digital image analysis provides an objective, precise, and accurate method of quantifying image characteristics. Automating these tasks is a high priority in the research and clinical community in providing a reproducible method for longitudinal analysis of various biological studies.

A dual and opposite effect of Calendula officinalis flower extract: chemoprotector and promoter in a rat hepatocarcinogenesis model

Calendula officinalis extracts have protective and cytotoxic effects. We previously reported the dual activity of C. officinalis in primary rat hepatocyte cultures treated with N-nitrosodiethylamine. At nM concentrations it was anti-genotoxic while at microM concentrations it exhibited genotoxic effects. Here we tested the activity of Calendula officinalis in vivo in male Fischer 344 rats initiated with N-nitrosodiethylamine, promoted with 2-acetylaminofluorene, and 70 % partially hepatectomized. Liver gamma-glutamyltranspeptidase positively altered hepatocyte foci 25 days after initiation were our end point. The protective effect of C. officinalis started at 0.1 mg/kg concentration, increased at 0.5 mg/kg and reached its maximum at 2.5 mg/kg, when it decreased the area and number of altered foci by 55 % and 49 %, respectively, in comparison with rats treated only with carcinogen. At 5 mg/kg the number and area of altered hepatocyte foci were still lower, but almost reached the figures of carcinogen-treated rats. Ten and 20 mg/kg doses produced a notorious increment in the area and number of altered hepatic foci, and at 40 mg/kg of extract the increment was 40 % and 53 %, respectively. Additionally, when 2-acetylaminofluorene was substituted by a 40 mg/kg C. officinalis extract, a promoting effect was observed with increments of 175 % and 266 % in area and number of altered hepatocyte foci with respect to controls. When N-nitrosodiethylamine was substituted by 40 mg/kg of extract, the latter did not show initiator activity. In summary, we showed a protecting activity of C. officinalis at low doses, but doses above 10 mg/kg increased altered hepatocyte foci. This dual effect is an example of the phenomenon of hormesis. Furthermore, 40 mg/kg of dry weight extract administered instead of 2-acetylaminofluorene induced a clear promoting activity. These in vivo results are similar and consistent with those reported by us in primary rat liver cell cultures.

Effect of alternating bulls as a management tool to improve the reproductive performance of suckled Zebu cows in the humid tropics of Costa Rica

A study was undertaken to evaluate the effect of alternating bulls between a single and a multiple sire mating (MSM) program on the reproductive performance of suckled Zebu cows raised under range conditions in the humid tropics of Costa Rica. Multiparous Zebu cows (n=94) suckling calves were distributed between two experimental trials (A and B) consisting of 47 animals each. A single sire mating (SSM) system was alternated weekly with a MSM system with three bulls. This period lasted for 8 weeks. To facilitate estrous expression, four cows were strategically synchronized (estrus-stimulated) in alternate weeks. Courtship predominated over mounting under non-stimulated estrus, for each mounting performed an average of 6.0 and 6.3 courtship activities were recorded in the SSM and MSM, respectively. Under the influence of strategic synchronization corresponding values were 3.9 and 4.2 in the SSM and MSM, respectively (P>0.05). Blood samples for progesterone evaluation were taken twice weekly. All cows in trial A were in anestrus at the start of the study. By second week, 5 out of the 47 cows had initiated estrous cycles and by the third week six were pregnant. In contrast in trial B, 9 out of 47 had initiated estrous cycles before interacting with the bulls and on week 3, only two females had become pregnant and three had initiated estrous cycles. Significant differences were found in the cumulative percentage of cows pregnant between trials A and B (P<0.05). Even though these results occurred, the rotation of the bulls (one or three), or the type of cows (estrus-stimulated or not) did not influence the results in this study.

Activity of diadenosine polyphosphates at P2Y receptors stably expressed in 1321N1 cells

The selectivities of the diadenosine polyphosphates (Ap(n)As, n=2-6) at the human P2Y(1), P2Y(2), P2Y(4), P2Y(6) and P2Y(11) receptors stably expressed in 1321N1 human astrocytoma cells was determined using a Fluorescence Imaging Plate Reader (FLIPR) to measure intracellular Ca(2+) mobilisation. The rank order of agonist potencies at P2Y(1) were: ADP>P(1),P(3)-diadenosine triphosphate (Ap(3)A)>P(1),P(3)-diadenosine hexaphosphate (Ap(6)A)=P(1),P(3)-diadenosine diphosphate (Ap(2)A)>>P(1),P(3)-diadenosine pentaphosphate (Ap(5)A). P(1),P(3)-diadenosine tetraphosphate (Ap(4)A) was inactive up to 1 mM. The rank order of agonist potencies at P2Y(2) were: UTP>Ap(4)A>>Ap(6)A>Ap(5)A>Ap(3)A>>Ap(2)A. The Ap(4)A concentration response curve appeared to be bi-phasic. At P2Y(4) all the Ap(n)As tested were inactive as agonists. At P2Y(6), only Ap(3)A and Ap(5)A showed significant agonist activity. At P2Y(11), only Ap(4)A showed significant agonist activity. Ap(n)As were inactive as antagonists of the P2Y(1), P2Y(2), P2Y(4), P2Y(6) and P2Y(11) receptors. At P2Y(4), however, the Ap(n)As potentiated the UTP response.

Scaling in steady-state aggregation with injection

A mean-field approach for steady-state aggregation with injection is presented. It is shown that for a wide variety of aggregation processes the resulting steady-size distribution obeys a power law N(m) approximately m(-alpha) with alpha=(3+beta)/2 and beta the degree of homogeneity of the coagulation kernel. The general conditions for this to happen are obtained. Some applications are studied. In particular, it predicts a potential behavior for coagulation in atmospheric aerosols with exponent alpha approximately 2, in agreement with observations. The theoretical results also agree with some animal group-size distributions and with numerical simulations in fractal aggregates.

Elevated secretion of myeloperoxidase by neutrophils from asthmatic patients: the effect of immunotherapy

BACKGROUND

There is increasing evidence of neutrophil participation in asthma and the allergic process. After activation, neutrophils release myeloperoxidase (MPO) together with other granule enzymes.

OBJECTIVES

In this study we attempted to evaluate the release of MPO in vitro by neutrophils from asthmatic patients and the relationship between neutrophil degranulation and lung function, measured as FEV(1), of the patients. We also investigated the possible role of immunotherapy in the release of MPO by neutrophils.

METHODS

Neutrophils were stimulated with formyl-methionyl-leucyl-phenylalanine for 45 minutes at 37 degrees C. MPO released from neutrophils was assayed by using an MPO enzyme immunoassay.

RESULTS

Neutrophils released statistically significantly higher MPO levels in the asthmatic patients not receiving immunotherapy than in the healthy group. A significant inverse correlation was observed in the asthmatic group not receiving immunotherapy between MPO secretion and lung function, measured as FEV(1), of the patients. Neutrophils of the asthmatic group receiving immunotherapy released significantly less MPO than did those of the asthmatic group not receiving immunotherapy, with MPO levels equal to those from nonallergic subjects.

CONCLUSIONS

We conclude that neutrophils obtained from allergic asthmatic patients have an increased propensity to release MPO. The experiments described here provide evidence that there is a significant inverse relationship between levels of MPO released by neutrophils from allergic patients and lung function, as assessed by FEV(1). Our study suggests that immunotherapy actively modifies the release of MPO in vitro by neutrophils from allergic asthmatic patients.